We describe a modified smoking machine to be used for monitoring the effects of narghile and ciga... more We describe a modified smoking machine to be used for monitoring the effects of narghile and cigarette tobacco smoke on experimental animals; a vacuum pump, a time controller, and an electronic valve that control the sequence of puff-and fresh air-inlet and exit into and out of the inhalation chamber. The design allows intake of enough tobacco smoke and prevents oxygen deprivation in the inhalation chamber.
The influence of blue-green light (496 nm) and blue light (450 nm) on contraction behaviour of pr... more The influence of blue-green light (496 nm) and blue light (450 nm) on contraction behaviour of protoplasmic strands, endoplasmic veins and “de novo” generation of contraction activity in endoplasmic drops of Physarum polycephalum was investigated. The contraction-relaxation cycle was divided into contraction (tc) and relaxation (tr) and separately analysed. Both wavelengths prolongated only the duration of contraction, whereas the duration of relaxation remained unaffected. The effect is quantitatively the same for endoplasmic veins and protoplasmic strands and is more pronounced in the case of blue light (450 nm).
Blue light shows not only an influence on the duration of contraction but also on the time point of “de novo” generation of oscillatory activity of endoplasmic drops. Since blue light reversibly inhibits both glucose consumption and acidification of the medium, the obtained results point to a modification of the contraction phase via energy metabolism. However, the influence of a plasmalemmal proton pump has also to be taken into account.
The distribution and density of intramembranous particles (IMP) in the plasma membrane of the ace... more The distribution and density of intramembranous particles (IMP) in the plasma membrane of the acellular slime mold Physarum polycephalum during sclerotization, sporulation and germination was investigated by means of freeze-etching. The total number of IMP on both the PF and EF of young as well as dry spores (2,100–2,200 IMP/μm2), wetted spores (1,550 IMP/μm2) and sclerotia (2,300 IMP/μm2) is remarkably reduced in comparison to the IMP-density in the plasma membrane of migrating plasmodia (3,680 IMP/μm2). The most obvious decrease in IMP-density can be observed in EF, i. e., the asymmetry of the cell membrane as expressed by the PF: EF ratio shifts from about 2.5 : 1 to 10 : 1. The cell surface of spores and sclerotia shows a regular pattern of elevations on the PF and corresponding indentations on the EF. On the PF the elevations display a distinct accumulation of IMP. The significance of the fine structural changes of the cell membrane during sclerotization, sporulation and the early stage of spore germination is discussed with regard to altered physiological conditions.
International journal of occupational medicine and environmental health, 2018
Objectives: To study any possible correlation between blood lead levels and some oxidative stress... more Objectives: To study any possible correlation between blood lead levels and some oxidative stress parameters of selected groups of lead-exposed automobile occupational Jordanian workers. Material and Methods: Blood lead levels were determined for a total of 90 male automobile workers aged within the range of 25-45 years old along with the group of 20 age-matched healthy males control. To get an idea about the antioxidant status of controls and lead-exposed workers, and to estimate the oxidative stress caused by exposure to lead, we measured the hydrogen peroxide (H 2 O 2) concentration, super-oxide dismutase (SOD) activity, lipid peroxidation as malondialdehyde (MDA) and total antioxidant capacity of controls and workers. Results: The study showed that lead levels in the case of workers were approximately 4-5 times as high as in controls 14.5-21 μg×dl-1 vs. 4.3 μg×dl-1 , respectively. There was a significant decrease (16-25%) in the level of plasma reduced glutathione and 21-33% decrease in total antioxidant capacity (TAOC) in all worker groups, as compared to controls. The results showed that the concentration of malondialdehyde (MDA) in plasma was higher (120-333%) in the case of workers than controls being the highest in automobile electronics and the lowest-in mechanics. Furthermore, there was 149-221% increase in hydrogen peroxide (H 2 O 2) concentration, and 26-38% increase in SOD activity in the case of workers compared to the control group. Conclusions: There is a strong evidence for the associations between occupational lead exposure and various markers of oxidative stress in Jordanian automobile occupational workers. Thus, there is an urgent need to raise awareness and to initiate suitable protection guidelines for workers. Int J Occup Med Environ Health 2018;31(4):517-525
Lead toxicity is a public health hazard particularly to the occupationally exposed workers. Evide... more Lead toxicity is a public health hazard particularly to the occupationally exposed workers. Evidence is mounting successively regarding the adverse health effects of lead at low levels. This study is conducted to assess lead cytotoxicity and the antioxidant status of selected groups of Jordanian workers occupationally exposed to lead poisoning or automobile buffs. A total of ninety male workers were selected for the study. The workers studied included: Radiator welders, exhaust workers, automobile electronics and mechanics, metal workers, and car painters in Amman city. The control group included 20 subjects of the same age group without any occupational exposure to lead. A number of biological parameters have been studied in order to estimate the degree of lead intoxication in the selected worker groups. The groups did not significantly differ among each other in the average of age (34± 0.9) and work years (17.1±1.8). The researchers studied the effect of exposure to lead on the activity of δ-ALAD (a key enzyme in heme biosynthesis). A significant decrease and a negative correlation between δ-ALAD and blood lead were observed in all the studied worker groups. The effect of exposure to lead on the morphology of RBCs was investigated. Fibrillation and particulate structures on the surface of RBCs and irregular plasma membrane evaginations were seen under scanning electron microscope.Determination of blood-lead concentration, δ-ALAD activity as well as morphological investigations of RBCs could be bebenificial in the evaluation of lead toxicity.
A new improvement in the production of cell-free models of Physarum for studying the physiology o... more A new improvement in the production of cell-free models of Physarum for studying the physiology of cytoplasmic actomyosin contraction in vivo is described. Cytoplasmic actomyosin fibrils were enriched in thin-spread plasmodia of Physarum by allowing them to spread on agar containing 2% ethanol. Polarizing microscopy of plasmodia before and after extraction showed a high density of enriched birefringent actomyosin fibrils. Plasmodia not treated with alcohol but prepared similarly showed lower density of birefringent actomyosin fibrils before and even less density after extraction. It seemed that alcohol treatment enriched and stabilized the actomyosin fibrils and that they were less affected by the process of extraction. It was shown, that the fibrils contain actin and their distribution was studied by fluorescent microscopy after staining with rhodamine-labelled phalloidin. These results may help to correlate the birefringent picture of actomyosin fibrils with their fluorescence and thus improve the cell-free model for reactivation studies.
β-Caryophyllene (β-Car) is a natural antioxidant. It is Cannabis-derived cannabinoid receptors ty... more β-Caryophyllene (β-Car) is a natural antioxidant. It is Cannabis-derived cannabinoid receptors type 2 (CB2R) agonist. CBR2 are expressed in germ cells within the testes. The aim of this study was to investigate the effect of β-Car on the male rat body weight, sex organ weight, sperm count, motility and morphology, and on the histology and the ultrastructure of the testes and the cauda epididymides. Moreover, we compared these effects with the results of the reversible infertility inducer: metronidazole (MTZ). Sexually mature male rats were divided into five groups that received intraperitoneal injections of 10 mg/kg β-Car, 40 mg/kg MTZ, distilled water, tween 80 in normal saline solution (10 % v/v), or did not receive any treatment for an experimental period of 30 days. Cauda epididymal sperm suspensions were used to assess the sperm count, motility, and morphology. Histological and ultrastructural studies were performed on testes and cauda epididymides. Treatment with β-Car (10 mg/kg, i.p.) significantly increased the final body weight, but did not affect the sex organ weight. It resulted in a significant decrease in cauda epididymal sperm count, percentages of motile sperms, and sperms with normal morphology. Nevertheless, it neither affected the histology nor the ultrastructure of the testes or the cauda epididymides of the treated rats. As a CB2R, β-Car could be a promising natural male contraceptive, because 30-day treatment with 10 mg/kg β-Car did not affect spermatogenesis but negatively affected spermiogenesis.
Silver nanoparticles (SNPs) are widely invested in nanomedicine and consuming products due to the... more Silver nanoparticles (SNPs) are widely invested in nanomedicine and consuming products due to their unique antimicrobial properties. However, little is known about the toxicity of these particles on human health. The present investigation was carried out to investigate the histological alterations induced in the lung tissues by 20±5 nm SNPs. Male albino Wistar rats were exposed to SNPs at a daily dose of 2 mg/kg for 21 days. Lung biopsies from all rats under study were subjected to histopathological examinations. Exposure to 20±5 nm SNPs induced the following pulmonary alterations: thickened alveolar wall, macrophages invasion and inflammatory cells infiltration, lymphatic follicles enlargement, pulmonary edema, alveolar hypersensitivity and interstitial congestion. Occasional atelectasis and fibrocytes proliferation were also detected. The findings of the present work might indicate that SNPs potentially trigger oxidative stress and alterations in the pulmonary tissues that may affect the function of the lungs.
The "de novo" generation of longitudinal contractile activity in endoplasmic veins is inhibited b... more The "de novo" generation of longitudinal contractile activity in endoplasmic veins is inhibited by 5 mM KCN, whereas 10 mM alpha-ketoglutarate combined with 5 mM AMP abolishes this inhibiting effect in spite of a continued presence of KCN. An analysis of the Young's modulus and studies on the morphogenesis of endoplasmic veins reveal morphological effects of an impediment of cell respiration: (1) an increased fibrillogenesis and changes in the spatial distribution of cytoplasmic actomyosin fibrils, (2) an impediment of the "de novo" generation of the plasmalemma invaginations, and (3) the appearance of a thick cortical layer of ground-plasm. These effects of KCN do not appear in the presence of alpha-ketoglutarate and AMP, and disappear by their subsequent application. Impediment of cell respiration by 5 mM KCN inhibits the tensiometrically registrable responses to glucose and blue light. Both reactions are restored in the presence of KCN by an additional application of 10 mM alpha-ketoglutarate combined with 5 mM AMP. The importance of mitochondrial function with respect to morphogenetic events and to the perception and transduction of external signals as well as to locomotory reactions of Physarum plasmodia is discussed.
A new synthetic thienopyridinone 2-chloro-7-cyclopropyl-4,7-dihydro-4-oxothieno-[2,3-b]pyridine-5... more A new synthetic thienopyridinone 2-chloro-7-cyclopropyl-4,7-dihydro-4-oxothieno-[2,3-b]pyridine-5-c a rboxylic acid was tested for its antimicrobial activity. A concentration of 5 mu g/ml completely inhibited the growth of Escherichia coli. Its minimal inhibitory concentration was determined for different Gram-positive and Gram-negative bacteria. Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas aeruginosa were resistant to 100 mu g/ml; Staphylococcus aureus, E. coli, Salmonella typhi, Shigella marcescens and Proteus vulgaris were sensitive to 5 mu g/ml. This indicates possible uses for the compound in treating infections caused by the sensitive bacterial species.
A trans microscope registration electronic system using cadmium sulphide photoconductive cell as ... more A trans microscope registration electronic system using cadmium sulphide photoconductive cell as light dependent resistor is described. This photocell has a spectral response similar to that of the human eye and enable registration of cellular motion phenomena along with their microscopic observation. The photocell is of the type ORP 12 which when replacing one of the oculars of the light microscope, can register changes in light intensity caused due to any movement of the studied living objects. The large diameter sensing element allows registration of full size of the contractile objects with a wide range of spectral sensitivity. Its application is reported for investigating the oscillatory contraction activity of plasmodial strands of the slime mold physarum polycephalum.
We have purified a giant titin-like protein from the acellular slime
mould Physarum polycephalum ... more We have purified a giant titin-like protein from the acellular slime mould Physarum polycephalum under denaturing conditions by gel filtration of a DNase/RNase-pretreated sodium dodecyl sulphate (SDS) extract or by salt fractionation followed by chromatography as proposed for titin purification from muscle [54, 56]. The amino acid composition of Physarum titin is similar to that of titin (connectin) from muscle. Peptide maps by limited proteolysis in SDS showed a high sensitivity to papain, while trypsin and chymotrypsin are nearly ineffective. Physarum titin, even in denaturant, tends to aggregate and after removal of the SDS to renature, reconstituting into an elastic gel composed of globular domains extending into linear superthin 2 to 3 nm filaments. By using a combination of critical point drying, dry-cleaving [34] and the platinum/carbon replication technique [10] as a highly efficient three dimensional visualization method (checked by model systems: myosin sub fragment 1 decorated actin, myofibrils, collagen), the existence and spatial arrangement of dense networks of superthin filaments have been demonstrated in Physarum in situ. Occasionally, the filaments show a bead-like structure, with nodules or globular domains. The superthin Physarum filament lattice is not decorated with myosin sub fragment 1. Ghost material obtained by extensive extraction with Triton X100/SDS/ethylene glycol bis(P-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or SDS/urea/dithiothreitol (DTT) represents covalently cross-linked remnants of the Physarum cytoskeleton. Electron microscopic examination of that ghosts reveals features similar to the reconstituted purified Physarum titin gel and to the superthin filament network in situ. SDS/urea/DIT extraction followed by an electrophoretic purification step leads to ghost material which is similarly composed of networks of superfine filaments with a high frequency of irregularly-spaced globular nodules. The amino acid composition of the covalently cross-linked matrices obtained by electrophoresis is identical to that of the titin-like protein purified by chromatography. Thus, the matrices seem to be aggregates of cross-linked titinlike protein. Tensiometric measurements of extracted ghosts revealed that they are highly elastic and are able to transmit tension forces generated by the addition of divalent cations in the millimolar range. The results suggest Physarum titin-like protein to be the major, if not the sole, component of a dynamic and elastic cytoskeletal superthin filament matrix existing throughout the cell and composed of globular domains unravelling into linear 2 to 3 nm filaments.
Extract of Catha edulis (khat) lowered the mitotic index in bone marrow cells of Swiss male mice ... more Extract of Catha edulis (khat) lowered the mitotic index in bone marrow cells of Swiss male mice at all times of exposure and in almost all the concentrations studied compared with corresponding controls. The reduction in the mitotic index revealed a mitodepressive effect of khat extract on the dividing bone marrow cells of mice. Following application of the lowest dose (125 mg/ml), 24 h was regarded the higher limit of time exposure in the experiments. After 24 h exposure and at the lowest dose (125 mg/ml) the effect of the khat extract started to decrease.
Lead is one of the poisonous heavy metals that affects the biotic system. In this research, the e... more Lead is one of the poisonous heavy metals that affects the biotic system. In this research, the effect of different lead chloride concentrations was studied on the acellular slime mold Physarum polycephalum cytoplasmic shuttle streaming, growth, structure and migration of Physarum plasmodium. The plasmodium was treated with different concentrations of lead chloride (15, 30, 45 and 50 µg/ml). The results showed that 50 µg/ml PbCl2 was the lethal dose, which caused irreversible high blebbing of the plasma membrane, disorganization and fragmentation of the plasmodial strands. The sublethal doses (15-45 µg/ml), caused mostly irreversible condensation of the plasmodial strands, blebbing of the plasma membrane, vacuolization of the cytoplasm and elongation of the cytoplasmic shuttle streaming period.
Undoubtedly, narghile smoking has become a common social practice in the Arab region, and a growi... more Undoubtedly, narghile smoking has become a common social practice in the Arab region, and a growing phenomenon in the whole world. This study is an attempt to reveal the effects of narghile smoking on the cellular level, through exposing a group of experimental albino rats to the smoke of two types of narghile tobacco-derived products: flavored (moassal) and unflavored (tumbak), for three months on a daily basis, using a specially designed smoking machine. The most prominent histological changes were an abnormal proliferation in the epithelium of trachea, disruption of its cilia, and a marked hyperplasia in the connective tissue of lung alveoli. Finally, further research should be done to give definitive conclusions about the product with an overall stronger effect. However, based on our experiment, smokers could be advised not to smoke on a daily basis and in poorly ventilated areas.
The effect of different concentrations of cadmium chloride on cytoplasmic shuttle streaming, grow... more The effect of different concentrations of cadmium chloride on cytoplasmic shuttle streaming, growth, structure and migration of plasmodial strand of Physarum was investigated. Concentrations 25.0 mM CdCl2 induced direct and rapid stop of cytoplasmic streaming followed by complete fixation of the treated plasmodia (neither growth nor migration occurred on nutrient agar plates).
Research Opinions in Animal and Veterinary Sciences, 2013
This work was an attempt to reveal the effects of a Jordanian cigarette smoke on albino rat tissu... more This work was an attempt to reveal the effects of a Jordanian cigarette smoke on albino rat tissues at the cellular level. Two groups of male albino rats were exposed to the cigarette smoke for three months on a daily basis, using a special modified smoking machine. Exposure of albino rats for 3 months to cigarette smoke caused drastic histological changes in the tracheal epithelium including epithelial cells proliferation, disruption of its cilia, and presence of inclusion bodies. There was a marked thickening in the alveolar wall of lung alveoli, collapsed alveoli and blood extravasations. These changes indicate that nicotine induced changes similar to those of chronic irritation of tissue may decrease the efficiency of gaseous exchange in alveoli and predispose to neoplastic changes.
Research Opinions in Animal & Veterinary Sciences, 2012
This work was an attempt to reveal the effects of a Jordanian cigarette smoke and pure L-nicotine... more This work was an attempt to reveal the effects of a Jordanian cigarette smoke and pure L-nicotine on the contractile activity of tracheal and aortic smooth muscles, and isolated perfused heart of albino rat. In tissue bath experiments, cigarette smoke extracts (CSE) and L-nicotine induced biphasic change in the tone of isolated precontracted-tracheal and aortic smooth muscles. In the case of isolated perfused heart, CSE and L-nicotine induced in most concentrations a significant concentration dependent reduction of the force and the rate of contraction of the perfused heart. One gram of cigarette tobacco produces an equivalent of 4.8 mg L-nicotine in cigarette smoke extract.
We describe a modified smoking machine to be used for monitoring the effects of narghile and ciga... more We describe a modified smoking machine to be used for monitoring the effects of narghile and cigarette tobacco smoke on experimental animals; a vacuum pump, a time controller, and an electronic valve that control the sequence of puff-and fresh air-inlet and exit into and out of the inhalation chamber. The design allows intake of enough tobacco smoke and prevents oxygen deprivation in the inhalation chamber.
The influence of blue-green light (496 nm) and blue light (450 nm) on contraction behaviour of pr... more The influence of blue-green light (496 nm) and blue light (450 nm) on contraction behaviour of protoplasmic strands, endoplasmic veins and “de novo” generation of contraction activity in endoplasmic drops of Physarum polycephalum was investigated. The contraction-relaxation cycle was divided into contraction (tc) and relaxation (tr) and separately analysed. Both wavelengths prolongated only the duration of contraction, whereas the duration of relaxation remained unaffected. The effect is quantitatively the same for endoplasmic veins and protoplasmic strands and is more pronounced in the case of blue light (450 nm).
Blue light shows not only an influence on the duration of contraction but also on the time point of “de novo” generation of oscillatory activity of endoplasmic drops. Since blue light reversibly inhibits both glucose consumption and acidification of the medium, the obtained results point to a modification of the contraction phase via energy metabolism. However, the influence of a plasmalemmal proton pump has also to be taken into account.
The distribution and density of intramembranous particles (IMP) in the plasma membrane of the ace... more The distribution and density of intramembranous particles (IMP) in the plasma membrane of the acellular slime mold Physarum polycephalum during sclerotization, sporulation and germination was investigated by means of freeze-etching. The total number of IMP on both the PF and EF of young as well as dry spores (2,100–2,200 IMP/μm2), wetted spores (1,550 IMP/μm2) and sclerotia (2,300 IMP/μm2) is remarkably reduced in comparison to the IMP-density in the plasma membrane of migrating plasmodia (3,680 IMP/μm2). The most obvious decrease in IMP-density can be observed in EF, i. e., the asymmetry of the cell membrane as expressed by the PF: EF ratio shifts from about 2.5 : 1 to 10 : 1. The cell surface of spores and sclerotia shows a regular pattern of elevations on the PF and corresponding indentations on the EF. On the PF the elevations display a distinct accumulation of IMP. The significance of the fine structural changes of the cell membrane during sclerotization, sporulation and the early stage of spore germination is discussed with regard to altered physiological conditions.
International journal of occupational medicine and environmental health, 2018
Objectives: To study any possible correlation between blood lead levels and some oxidative stress... more Objectives: To study any possible correlation between blood lead levels and some oxidative stress parameters of selected groups of lead-exposed automobile occupational Jordanian workers. Material and Methods: Blood lead levels were determined for a total of 90 male automobile workers aged within the range of 25-45 years old along with the group of 20 age-matched healthy males control. To get an idea about the antioxidant status of controls and lead-exposed workers, and to estimate the oxidative stress caused by exposure to lead, we measured the hydrogen peroxide (H 2 O 2) concentration, super-oxide dismutase (SOD) activity, lipid peroxidation as malondialdehyde (MDA) and total antioxidant capacity of controls and workers. Results: The study showed that lead levels in the case of workers were approximately 4-5 times as high as in controls 14.5-21 μg×dl-1 vs. 4.3 μg×dl-1 , respectively. There was a significant decrease (16-25%) in the level of plasma reduced glutathione and 21-33% decrease in total antioxidant capacity (TAOC) in all worker groups, as compared to controls. The results showed that the concentration of malondialdehyde (MDA) in plasma was higher (120-333%) in the case of workers than controls being the highest in automobile electronics and the lowest-in mechanics. Furthermore, there was 149-221% increase in hydrogen peroxide (H 2 O 2) concentration, and 26-38% increase in SOD activity in the case of workers compared to the control group. Conclusions: There is a strong evidence for the associations between occupational lead exposure and various markers of oxidative stress in Jordanian automobile occupational workers. Thus, there is an urgent need to raise awareness and to initiate suitable protection guidelines for workers. Int J Occup Med Environ Health 2018;31(4):517-525
Lead toxicity is a public health hazard particularly to the occupationally exposed workers. Evide... more Lead toxicity is a public health hazard particularly to the occupationally exposed workers. Evidence is mounting successively regarding the adverse health effects of lead at low levels. This study is conducted to assess lead cytotoxicity and the antioxidant status of selected groups of Jordanian workers occupationally exposed to lead poisoning or automobile buffs. A total of ninety male workers were selected for the study. The workers studied included: Radiator welders, exhaust workers, automobile electronics and mechanics, metal workers, and car painters in Amman city. The control group included 20 subjects of the same age group without any occupational exposure to lead. A number of biological parameters have been studied in order to estimate the degree of lead intoxication in the selected worker groups. The groups did not significantly differ among each other in the average of age (34± 0.9) and work years (17.1±1.8). The researchers studied the effect of exposure to lead on the activity of δ-ALAD (a key enzyme in heme biosynthesis). A significant decrease and a negative correlation between δ-ALAD and blood lead were observed in all the studied worker groups. The effect of exposure to lead on the morphology of RBCs was investigated. Fibrillation and particulate structures on the surface of RBCs and irregular plasma membrane evaginations were seen under scanning electron microscope.Determination of blood-lead concentration, δ-ALAD activity as well as morphological investigations of RBCs could be bebenificial in the evaluation of lead toxicity.
A new improvement in the production of cell-free models of Physarum for studying the physiology o... more A new improvement in the production of cell-free models of Physarum for studying the physiology of cytoplasmic actomyosin contraction in vivo is described. Cytoplasmic actomyosin fibrils were enriched in thin-spread plasmodia of Physarum by allowing them to spread on agar containing 2% ethanol. Polarizing microscopy of plasmodia before and after extraction showed a high density of enriched birefringent actomyosin fibrils. Plasmodia not treated with alcohol but prepared similarly showed lower density of birefringent actomyosin fibrils before and even less density after extraction. It seemed that alcohol treatment enriched and stabilized the actomyosin fibrils and that they were less affected by the process of extraction. It was shown, that the fibrils contain actin and their distribution was studied by fluorescent microscopy after staining with rhodamine-labelled phalloidin. These results may help to correlate the birefringent picture of actomyosin fibrils with their fluorescence and thus improve the cell-free model for reactivation studies.
β-Caryophyllene (β-Car) is a natural antioxidant. It is Cannabis-derived cannabinoid receptors ty... more β-Caryophyllene (β-Car) is a natural antioxidant. It is Cannabis-derived cannabinoid receptors type 2 (CB2R) agonist. CBR2 are expressed in germ cells within the testes. The aim of this study was to investigate the effect of β-Car on the male rat body weight, sex organ weight, sperm count, motility and morphology, and on the histology and the ultrastructure of the testes and the cauda epididymides. Moreover, we compared these effects with the results of the reversible infertility inducer: metronidazole (MTZ). Sexually mature male rats were divided into five groups that received intraperitoneal injections of 10 mg/kg β-Car, 40 mg/kg MTZ, distilled water, tween 80 in normal saline solution (10 % v/v), or did not receive any treatment for an experimental period of 30 days. Cauda epididymal sperm suspensions were used to assess the sperm count, motility, and morphology. Histological and ultrastructural studies were performed on testes and cauda epididymides. Treatment with β-Car (10 mg/kg, i.p.) significantly increased the final body weight, but did not affect the sex organ weight. It resulted in a significant decrease in cauda epididymal sperm count, percentages of motile sperms, and sperms with normal morphology. Nevertheless, it neither affected the histology nor the ultrastructure of the testes or the cauda epididymides of the treated rats. As a CB2R, β-Car could be a promising natural male contraceptive, because 30-day treatment with 10 mg/kg β-Car did not affect spermatogenesis but negatively affected spermiogenesis.
Silver nanoparticles (SNPs) are widely invested in nanomedicine and consuming products due to the... more Silver nanoparticles (SNPs) are widely invested in nanomedicine and consuming products due to their unique antimicrobial properties. However, little is known about the toxicity of these particles on human health. The present investigation was carried out to investigate the histological alterations induced in the lung tissues by 20±5 nm SNPs. Male albino Wistar rats were exposed to SNPs at a daily dose of 2 mg/kg for 21 days. Lung biopsies from all rats under study were subjected to histopathological examinations. Exposure to 20±5 nm SNPs induced the following pulmonary alterations: thickened alveolar wall, macrophages invasion and inflammatory cells infiltration, lymphatic follicles enlargement, pulmonary edema, alveolar hypersensitivity and interstitial congestion. Occasional atelectasis and fibrocytes proliferation were also detected. The findings of the present work might indicate that SNPs potentially trigger oxidative stress and alterations in the pulmonary tissues that may affect the function of the lungs.
The "de novo" generation of longitudinal contractile activity in endoplasmic veins is inhibited b... more The "de novo" generation of longitudinal contractile activity in endoplasmic veins is inhibited by 5 mM KCN, whereas 10 mM alpha-ketoglutarate combined with 5 mM AMP abolishes this inhibiting effect in spite of a continued presence of KCN. An analysis of the Young's modulus and studies on the morphogenesis of endoplasmic veins reveal morphological effects of an impediment of cell respiration: (1) an increased fibrillogenesis and changes in the spatial distribution of cytoplasmic actomyosin fibrils, (2) an impediment of the "de novo" generation of the plasmalemma invaginations, and (3) the appearance of a thick cortical layer of ground-plasm. These effects of KCN do not appear in the presence of alpha-ketoglutarate and AMP, and disappear by their subsequent application. Impediment of cell respiration by 5 mM KCN inhibits the tensiometrically registrable responses to glucose and blue light. Both reactions are restored in the presence of KCN by an additional application of 10 mM alpha-ketoglutarate combined with 5 mM AMP. The importance of mitochondrial function with respect to morphogenetic events and to the perception and transduction of external signals as well as to locomotory reactions of Physarum plasmodia is discussed.
A new synthetic thienopyridinone 2-chloro-7-cyclopropyl-4,7-dihydro-4-oxothieno-[2,3-b]pyridine-5... more A new synthetic thienopyridinone 2-chloro-7-cyclopropyl-4,7-dihydro-4-oxothieno-[2,3-b]pyridine-5-c a rboxylic acid was tested for its antimicrobial activity. A concentration of 5 mu g/ml completely inhibited the growth of Escherichia coli. Its minimal inhibitory concentration was determined for different Gram-positive and Gram-negative bacteria. Bacillus subtilis, Klebsiella pneumoniae and Pseudomonas aeruginosa were resistant to 100 mu g/ml; Staphylococcus aureus, E. coli, Salmonella typhi, Shigella marcescens and Proteus vulgaris were sensitive to 5 mu g/ml. This indicates possible uses for the compound in treating infections caused by the sensitive bacterial species.
A trans microscope registration electronic system using cadmium sulphide photoconductive cell as ... more A trans microscope registration electronic system using cadmium sulphide photoconductive cell as light dependent resistor is described. This photocell has a spectral response similar to that of the human eye and enable registration of cellular motion phenomena along with their microscopic observation. The photocell is of the type ORP 12 which when replacing one of the oculars of the light microscope, can register changes in light intensity caused due to any movement of the studied living objects. The large diameter sensing element allows registration of full size of the contractile objects with a wide range of spectral sensitivity. Its application is reported for investigating the oscillatory contraction activity of plasmodial strands of the slime mold physarum polycephalum.
We have purified a giant titin-like protein from the acellular slime
mould Physarum polycephalum ... more We have purified a giant titin-like protein from the acellular slime mould Physarum polycephalum under denaturing conditions by gel filtration of a DNase/RNase-pretreated sodium dodecyl sulphate (SDS) extract or by salt fractionation followed by chromatography as proposed for titin purification from muscle [54, 56]. The amino acid composition of Physarum titin is similar to that of titin (connectin) from muscle. Peptide maps by limited proteolysis in SDS showed a high sensitivity to papain, while trypsin and chymotrypsin are nearly ineffective. Physarum titin, even in denaturant, tends to aggregate and after removal of the SDS to renature, reconstituting into an elastic gel composed of globular domains extending into linear superthin 2 to 3 nm filaments. By using a combination of critical point drying, dry-cleaving [34] and the platinum/carbon replication technique [10] as a highly efficient three dimensional visualization method (checked by model systems: myosin sub fragment 1 decorated actin, myofibrils, collagen), the existence and spatial arrangement of dense networks of superthin filaments have been demonstrated in Physarum in situ. Occasionally, the filaments show a bead-like structure, with nodules or globular domains. The superthin Physarum filament lattice is not decorated with myosin sub fragment 1. Ghost material obtained by extensive extraction with Triton X100/SDS/ethylene glycol bis(P-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or SDS/urea/dithiothreitol (DTT) represents covalently cross-linked remnants of the Physarum cytoskeleton. Electron microscopic examination of that ghosts reveals features similar to the reconstituted purified Physarum titin gel and to the superthin filament network in situ. SDS/urea/DIT extraction followed by an electrophoretic purification step leads to ghost material which is similarly composed of networks of superfine filaments with a high frequency of irregularly-spaced globular nodules. The amino acid composition of the covalently cross-linked matrices obtained by electrophoresis is identical to that of the titin-like protein purified by chromatography. Thus, the matrices seem to be aggregates of cross-linked titinlike protein. Tensiometric measurements of extracted ghosts revealed that they are highly elastic and are able to transmit tension forces generated by the addition of divalent cations in the millimolar range. The results suggest Physarum titin-like protein to be the major, if not the sole, component of a dynamic and elastic cytoskeletal superthin filament matrix existing throughout the cell and composed of globular domains unravelling into linear 2 to 3 nm filaments.
Extract of Catha edulis (khat) lowered the mitotic index in bone marrow cells of Swiss male mice ... more Extract of Catha edulis (khat) lowered the mitotic index in bone marrow cells of Swiss male mice at all times of exposure and in almost all the concentrations studied compared with corresponding controls. The reduction in the mitotic index revealed a mitodepressive effect of khat extract on the dividing bone marrow cells of mice. Following application of the lowest dose (125 mg/ml), 24 h was regarded the higher limit of time exposure in the experiments. After 24 h exposure and at the lowest dose (125 mg/ml) the effect of the khat extract started to decrease.
Lead is one of the poisonous heavy metals that affects the biotic system. In this research, the e... more Lead is one of the poisonous heavy metals that affects the biotic system. In this research, the effect of different lead chloride concentrations was studied on the acellular slime mold Physarum polycephalum cytoplasmic shuttle streaming, growth, structure and migration of Physarum plasmodium. The plasmodium was treated with different concentrations of lead chloride (15, 30, 45 and 50 µg/ml). The results showed that 50 µg/ml PbCl2 was the lethal dose, which caused irreversible high blebbing of the plasma membrane, disorganization and fragmentation of the plasmodial strands. The sublethal doses (15-45 µg/ml), caused mostly irreversible condensation of the plasmodial strands, blebbing of the plasma membrane, vacuolization of the cytoplasm and elongation of the cytoplasmic shuttle streaming period.
Undoubtedly, narghile smoking has become a common social practice in the Arab region, and a growi... more Undoubtedly, narghile smoking has become a common social practice in the Arab region, and a growing phenomenon in the whole world. This study is an attempt to reveal the effects of narghile smoking on the cellular level, through exposing a group of experimental albino rats to the smoke of two types of narghile tobacco-derived products: flavored (moassal) and unflavored (tumbak), for three months on a daily basis, using a specially designed smoking machine. The most prominent histological changes were an abnormal proliferation in the epithelium of trachea, disruption of its cilia, and a marked hyperplasia in the connective tissue of lung alveoli. Finally, further research should be done to give definitive conclusions about the product with an overall stronger effect. However, based on our experiment, smokers could be advised not to smoke on a daily basis and in poorly ventilated areas.
The effect of different concentrations of cadmium chloride on cytoplasmic shuttle streaming, grow... more The effect of different concentrations of cadmium chloride on cytoplasmic shuttle streaming, growth, structure and migration of plasmodial strand of Physarum was investigated. Concentrations 25.0 mM CdCl2 induced direct and rapid stop of cytoplasmic streaming followed by complete fixation of the treated plasmodia (neither growth nor migration occurred on nutrient agar plates).
Research Opinions in Animal and Veterinary Sciences, 2013
This work was an attempt to reveal the effects of a Jordanian cigarette smoke on albino rat tissu... more This work was an attempt to reveal the effects of a Jordanian cigarette smoke on albino rat tissues at the cellular level. Two groups of male albino rats were exposed to the cigarette smoke for three months on a daily basis, using a special modified smoking machine. Exposure of albino rats for 3 months to cigarette smoke caused drastic histological changes in the tracheal epithelium including epithelial cells proliferation, disruption of its cilia, and presence of inclusion bodies. There was a marked thickening in the alveolar wall of lung alveoli, collapsed alveoli and blood extravasations. These changes indicate that nicotine induced changes similar to those of chronic irritation of tissue may decrease the efficiency of gaseous exchange in alveoli and predispose to neoplastic changes.
Research Opinions in Animal & Veterinary Sciences, 2012
This work was an attempt to reveal the effects of a Jordanian cigarette smoke and pure L-nicotine... more This work was an attempt to reveal the effects of a Jordanian cigarette smoke and pure L-nicotine on the contractile activity of tracheal and aortic smooth muscles, and isolated perfused heart of albino rat. In tissue bath experiments, cigarette smoke extracts (CSE) and L-nicotine induced biphasic change in the tone of isolated precontracted-tracheal and aortic smooth muscles. In the case of isolated perfused heart, CSE and L-nicotine induced in most concentrations a significant concentration dependent reduction of the force and the rate of contraction of the perfused heart. One gram of cigarette tobacco produces an equivalent of 4.8 mg L-nicotine in cigarette smoke extract.
The 1st International Conference of the Jordanian Faculties of Pharmacy, 2015
Metronidazole (MTZ) is an essential drug that is used as an antibiotic and as an antiprotozoal ag... more Metronidazole (MTZ) is an essential drug that is used as an antibiotic and as an antiprotozoal agent. Unfortunately, MTZ is known to induce reversible male infertility in high doses. Camphene (Cam) is a natural antioxidant that possesses many biological activities and constitutes a minor part of many essential oils including turpentine oil, cypress oil, citronella oil and ginger oil. Cam is present in apricot, carrots, cinnamon, ginger, cumin seed, nutmeg, cardamom and turmeric. Therefore, in this study we investigated the potential use of Cam to reverse the negative effects of MTZ on male fertility. Cam was studied in rats with and without the induction of infertility by MTZ. Cauda epididymal sperm suspensions were used to assess the sperm count, motility and morphology. Histological and ultrastructural studies were performed on testes and cauda epididymides. In sexually mature rats that were not subjected to infertility induction, Cam significantly increased the overall final body weight. However, Cam did not affect the sex organs weight, sperm motility and count, nor testis and cauda epididymides histology or ultrastructure. Interestingly, in sexually mature rats that were subjected to infertility induction by MTZ, Cam could reverse the damaging effects of MTZ on sperm count and percentage of sperms with normal morphology. Nevertheless, Cam could partially reverse the harmful effects of MTZ on the sperm ultrastructure. Our findings have great clinical implications and suggest a possible use for Cam to reverse the negative effects of MTZ on male fertility, reproductive system and spermatogenesis.
1Department of Medical Laboratory Sciences, Faculty of Pharmacy, Jadara University, Irbid, Jordan... more 1Department of Medical Laboratory Sciences, Faculty of Pharmacy, Jadara University, Irbid, Jordan. 2Department of Biological Sciences, School of Science, The University of Jordan, Amman, Jordan. 3Department of Anatomy and Histology, School of Medicine, The University of Jordan, Amman, Jordan. 4Department of Medical Laboratory Science, College of Science, Komar University of Science and Technology, Sulaymaniyah, Kurdistan region, Iraq. 5Department of Pathology and Microbiology and Forensic Medicine, Faculty of Medicine, The University of Jordan, Amman, Jordan. 6Royal Medical Services, Zarqa., Jordan. 7Pharmacological and Diagnostic Research Center (PDRC), Faculty of Pharmacy, Al-Ahliyya Amman University, Amman 19328, Jordan. *Corresponding Author E-mail: m.alqaraleh@ammanu.edu.jo
Exposure to Lead (Pb 2+) in its organic and inorganic forms is known to have deleterious effects ... more Exposure to Lead (Pb 2+) in its organic and inorganic forms is known to have deleterious effects on the health of individuals. Several studies showed that these effects are due to accumulation in vital organs and induction of oxidative stress. This study examines the possibility of three different antioxidant substances (Aqueous garlic extract, Vitamin C and Vitamin E – Selenium) to act as chelating agents against organolead toxicity (lead acetate) by decreasing its accumulation in liver and spleen. To achieve this purpose, forty-eight adult male albino rats were divided into eight equal groups; Group I: Control received normal water, Group II: received lead acetate (100 mg/kg/day; i.p), Group III: received garlic (100 mg/kg; orally), Group IV: received Lead (100 mg/kg/day; i.p) + Garlic (100 mg/kg; orally), Group V: received Vitamin C (100 mg/kg; orally), Group VI: received Lead (100 mg/kg/day; i.p) + Vitamin C (100 mg/kg; orally). Group VII: received Vitamin E (100 mg/kg; orally) ...
1Department of Medical Laboratory Sciences, Faculty of Pharmacy, Jadara University, Irbid, Jordan... more 1Department of Medical Laboratory Sciences, Faculty of Pharmacy, Jadara University, Irbid, Jordan. 2Department of Biological Sciences, School of Science, The University of Jordan, Amman, Jordan. 3Department of Anatomy and Histology, School of Medicine, The University of Jordan, Amman, Jordan. 4Department of Medical Laboratory Science, College of Science, Komar University of Science and Technology, Sulaymaniyah, Kurdistan region, Iraq. 5Department of Pathology and Microbiology and Forensic Medicine, Faculty of Medicine, The University of Jordan, Amman, Jordan. 6Royal Medical Services, Zarqa., Jordan. 7Pharmacological and Diagnostic Research Center (PDRC), Faculty of Pharmacy, Al-Ahliyya Amman University, Amman 19328, Jordan. *Corresponding Author E-mail: m.alqaraleh@ammanu.edu.jo
Smoking posse's serious health problems because there is no specific substance alleviate its toxi... more Smoking posse's serious health problems because there is no specific substance alleviate its toxicity. The aim of this study was to investigate the effective plant extract containing antioxidants(turmeric and cocoa), that may reduce the cytotoxicity induced by secondhand exposure of cigarettes and water pipe smoking. Seventy-two adult male albino rats were equally divided into 9 group (n=8 per group). Extracts were delivered to each group intraperitoneal, and the exposure to cigarette and water pipe smoking was performed using a smoking machine for a period of 30 days. After the exposure period, tissues of interest (liver and small intestine) were removed and processed for transmission electron microscopy. Oral treatment of turmeric and cocoa extract with smoking exposure showed less vacuolization and better cellular architecture with regular nuclear envelope of hepatocytes, reduce or absence of blebbing, retain the normal shape and size of mitochondria, increase the proportion of euchromatic chromatin in nuclei,but turmeric extract showed better enhancement in term of reducing vacuolization. turmeric or cocoa crude extract preserve the typical length of microvilli with a uniform organization from the apical part of enterocytes and decreased vacuolization in the cytosol of enterocytes. However, mitochondria appeared less polymorphic in shapes with distinct cristae and matrix in enterocytes of the turmeric treated group than the cocoa once. Tobacco smoking-induced adverse effects on hepatocytes and enterocytes, this study showed that treatment with turmeric and cocoa attenuatethe toxicity of tobacco smoking.
Undoubtedly, narghile smoking has become a common social practice in the Arab region, and a growi... more Undoubtedly, narghile smoking has become a common social practice in the Arab region, and a growing phenomenon in the whole world. This study is an attempt to reveal the effects of narghile smoking on the cellular level, through exposing a group of experimental albino rats to the smoke of two types of narghile tobacco-derived products: flavored (moassal) and unflavored (tumbak), for three months on a daily basis, using a specially designed smoking machine. The most prominent histological changes were an abnormal proliferation in the epithelium of trachea, disruption of its cilia, and a marked hyperplasia in the connective tissue of lung alveoli. Finally, further research should be done to give definitive conclusions about the product with an overall stronger effect. However, based on our experiment, smokers could be advised not to smoke on a daily basis and in poorly ventilated areas.
Smoking posse's serious health problems because there is no specific substance alleviate its ... more Smoking posse's serious health problems because there is no specific substance alleviate its toxicity. The aim of this study was to investigate the effective plant extract containing antioxidants(turmeric and cocoa), that may reduce the cytotoxicity induced by secondhand exposure of cigarettes and water pipe smoking. Seventy-two adult male albino rats were equally divided into 9 group (n=8 per group). Extracts were delivered to each group intraperitoneal, and the exposure to cigarette and water pipe smoking was performed using a smoking machine for a period of 30 days. After the exposure period, tissues of interest (liver and small intestine) were removed and processed for transmission electron microscopy. Oral treatment of turmeric and cocoa extract with smoking exposure showed less vacuolization and better cellular architecture with regular nuclear envelope of hepatocytes, reduce or absence of blebbing, retain the normal shape and size of mitochondria, increase the proportion ...
This study aims to evaluate the chemopreventive activity of two antioxidants (curcumin [CUM] and ... more This study aims to evaluate the chemopreventive activity of two antioxidants (curcumin [CUM] and caffeic acid [CAF]), focusing on how these antioxidants could reduce cytotoxicity induced by short term secondhand exposure of waterpipe tobacco smoking. Forty-eight adult male BALB/c albino mice were equally divided into four groups. Antioxidants were delivered intraperitoneally, and the exposure to waterpipe smoking (WPS) was performed using a smoking machine. This experiment lasts for 14 consecutive days. Serum were collected from mice before dissection to quantify the activity of some liver enzymes, kidney function tests and proinflammatory cytokines. Lung, heart, and kidney were isolated and processed for light microscopy technique. Parallel treatment of CUM or CAF along with exposure to WPS showed less inflammation, less vacuolized, and more inflated alveoli, less deteriorations in cortex part of kidney, and less disintegration of cardiac myofibers in comparison to waterpipe only. Besides, CUM and CAF significantly reduced the activity of aspartate aminotransferase and proinflammatory cytokines. CUM and CAF were found to have anti-inflammatory and ameliorative effects against the cytotoxicity induced by exposure to waterpipe tobacco smoking, and CUM showed better chemopreventive activity than CAF.
The effect of triethyl lead (TriEL) as triethyl lead chloride on the rhythmic peristaltic contrac... more The effect of triethyl lead (TriEL) as triethyl lead chloride on the rhythmic peristaltic contractile activity of ileum isolated from Swiss white mice was investigated, with the aid of a tensiometer. The response was measured as a change in period duration and force amplitude. TriEL concentrations of < 40 microM did not show any obvious effects on either of the parameters. In the concentration range between 40 and 120 microM, TriEL exclusively affected the rhythm of contractions in a concentration-dependent manner. It induced elongation of the period and reduction of the force amplitude. Concentrations of TriEL above 120 microM induced irreversible dramatic changes in the ileum contractile activity, while 200 microM TriEL induced a strong contracture followed by an irreversible cessation of the oscillatory contractile activity. The results demonstrate that the measurement of rhythmic contractions may be a useful model for a toxicological screening system.
5 mM KCN as well as anoxia have corresponding effects on Physarum plasmodia: Both induce a disint... more 5 mM KCN as well as anoxia have corresponding effects on Physarum plasmodia: Both induce a disintegration of the plasmalemma invaginations, an increase in cytoplasmic vacuoles, formation of a thick cortical actomyosin layer and an increase of cytoplasmic actomyosin fibrils. Both KCN treatment and anoxia cause a temporary increase in the level of the force oscillations and a reversible prolongation of the periods of the contraction-relaxation cycle of cytoplasmic actomyosin. The normal pattern of oscillation can be restored by the addition of 10 mM alpha-ketoglutarate +5 mM AMP to the solution containing 5 mM KCN. A combination of the Ca2+ ionophore A-23187 and KCN induces a strong contracture, whereas a combination of KCN, ionophore, alpha-ketoglutarate and AMP prevents this effect. The state of contracture is characterised by a pronounced increase in the Young's modulus and an increased fibrillogenesis of cytoplasmic actomyosin. The isometrically contracted state during the hig...
Tobacco smoking is considered the primary causative agent for lung cancer and chronic obstructive... more Tobacco smoking is considered the primary causative agent for lung cancer and chronic obstructive pulmonary disease. Their particulate materials and gaseous phase contain multiple toxic chemicals and free radicals that induce oxidative stress in mammalians. Many therapeutic drugs and natural herbs were tested in the last 50 years to examine the possibility of these drugs to have prophylactic effects against the cytotoxicity of tobacco smoking. Resveratrol (RSV) is a promising exogenous antioxidant that gives raised in the last 20 years due to its high free radical scavenging capacity and ability to act as an antioxidant, anti-inflammatory and anti-aging agent against many toxins and heavy metals.In this study, it was proposed whether the antioxidant RSV has an ameliorative effect against the cytotoxicity of two wild forms of tobacco smoking: cigarette (CS) and waterpipe (WPS) tobacco smoking,on the trachea of experimental mice. Forty-eight adult male albino BALB/c mice (6-8 weeks ol...
The "de novo" generation of longitudinal contractile activity in endoplasmic veins is i... more The "de novo" generation of longitudinal contractile activity in endoplasmic veins is inhibited by 5 mM KCN, whereas 10 mM alpha-ketoglutarate combined with 5 mM AMP abolishes this inhibiting effect in spite of a continued presence of KCN. An analysis of the Young's modulus and studies on the morphogenesis of endoplasmic veins reveal morphological effects of an impediment of cell respiration: (1) an increased fibrillogenesis and changes in the spatial distribution of cytoplasmic actomyosin fibrils, (2) an impediment of the "de novo" generation of the plasmalemma invaginations, and (3) the appearance of a thick cortical layer of ground-plasm. These effects of KCN do not appear in the presence of alpha-ketoglutarate and AMP, and disappear by their subsequent application. Impediment of cell respiration by 5 mM KCN inhibits the tensiometrically registrable responses to glucose and blue light. Both reactions are restored in the presence of KCN by an additional app...
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Articles by Ziad Shraideh
Blue light shows not only an influence on the duration of contraction but also on the time point of “de novo” generation of oscillatory activity of endoplasmic drops. Since blue light reversibly inhibits both glucose consumption and acidification of the medium, the obtained results point to a modification of the contraction phase via energy metabolism. However, the influence of a plasmalemmal proton pump has also to be taken into account.
mould Physarum polycephalum under denaturing conditions by
gel filtration of a DNase/RNase-pretreated sodium dodecyl sulphate (SDS) extract or by salt fractionation followed by chromatography as proposed for titin purification from muscle [54, 56].
The amino acid composition of Physarum titin is similar to that
of titin (connectin) from muscle. Peptide maps by limited proteolysis in SDS showed a high sensitivity to papain, while trypsin and chymotrypsin are nearly ineffective.
Physarum titin, even in denaturant, tends to aggregate and after
removal of the SDS to renature, reconstituting into an elastic gel
composed of globular domains extending into linear superthin 2 to
3 nm filaments.
By using a combination of critical point drying, dry-cleaving [34] and the platinum/carbon replication technique [10] as a highly efficient three dimensional visualization method (checked by model systems: myosin sub fragment 1 decorated actin, myofibrils, collagen), the existence and spatial arrangement of dense networks of superthin filaments have been demonstrated in Physarum in situ.
Occasionally, the filaments show a bead-like structure, with nodules or globular domains. The superthin Physarum filament lattice is not decorated with myosin sub fragment 1. Ghost material obtained by extensive extraction with Triton X100/SDS/ethylene glycol bis(P-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or SDS/urea/dithiothreitol (DTT) represents covalently cross-linked remnants of the Physarum cytoskeleton. Electron microscopic examination of that ghosts reveals features similar to the reconstituted purified Physarum titin gel and to the superthin filament network in situ. SDS/urea/DIT extraction followed by an electrophoretic purification step leads to ghost material which is similarly composed of networks of superfine filaments with a high frequency of irregularly-spaced globular nodules. The amino acid composition of the covalently cross-linked matrices obtained by electrophoresis is identical to that of the titin-like protein purified by chromatography. Thus, the matrices seem to be aggregates of cross-linked titinlike protein.
Tensiometric measurements of extracted ghosts revealed that they are highly elastic and are able to transmit tension forces generated by the addition of divalent cations in the millimolar range.
The results suggest Physarum titin-like protein to be the major, if not the sole, component of a dynamic and elastic cytoskeletal superthin filament matrix existing throughout the cell and composed of globular domains unravelling into linear 2 to 3 nm filaments.
Blue light shows not only an influence on the duration of contraction but also on the time point of “de novo” generation of oscillatory activity of endoplasmic drops. Since blue light reversibly inhibits both glucose consumption and acidification of the medium, the obtained results point to a modification of the contraction phase via energy metabolism. However, the influence of a plasmalemmal proton pump has also to be taken into account.
mould Physarum polycephalum under denaturing conditions by
gel filtration of a DNase/RNase-pretreated sodium dodecyl sulphate (SDS) extract or by salt fractionation followed by chromatography as proposed for titin purification from muscle [54, 56].
The amino acid composition of Physarum titin is similar to that
of titin (connectin) from muscle. Peptide maps by limited proteolysis in SDS showed a high sensitivity to papain, while trypsin and chymotrypsin are nearly ineffective.
Physarum titin, even in denaturant, tends to aggregate and after
removal of the SDS to renature, reconstituting into an elastic gel
composed of globular domains extending into linear superthin 2 to
3 nm filaments.
By using a combination of critical point drying, dry-cleaving [34] and the platinum/carbon replication technique [10] as a highly efficient three dimensional visualization method (checked by model systems: myosin sub fragment 1 decorated actin, myofibrils, collagen), the existence and spatial arrangement of dense networks of superthin filaments have been demonstrated in Physarum in situ.
Occasionally, the filaments show a bead-like structure, with nodules or globular domains. The superthin Physarum filament lattice is not decorated with myosin sub fragment 1. Ghost material obtained by extensive extraction with Triton X100/SDS/ethylene glycol bis(P-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or SDS/urea/dithiothreitol (DTT) represents covalently cross-linked remnants of the Physarum cytoskeleton. Electron microscopic examination of that ghosts reveals features similar to the reconstituted purified Physarum titin gel and to the superthin filament network in situ. SDS/urea/DIT extraction followed by an electrophoretic purification step leads to ghost material which is similarly composed of networks of superfine filaments with a high frequency of irregularly-spaced globular nodules. The amino acid composition of the covalently cross-linked matrices obtained by electrophoresis is identical to that of the titin-like protein purified by chromatography. Thus, the matrices seem to be aggregates of cross-linked titinlike protein.
Tensiometric measurements of extracted ghosts revealed that they are highly elastic and are able to transmit tension forces generated by the addition of divalent cations in the millimolar range.
The results suggest Physarum titin-like protein to be the major, if not the sole, component of a dynamic and elastic cytoskeletal superthin filament matrix existing throughout the cell and composed of globular domains unravelling into linear 2 to 3 nm filaments.