The characteristics of water diffusional permeability (P) of human red blood cells were studied o... more The characteristics of water diffusional permeability (P) of human red blood cells were studied on isolated erythrocytes by a doping nuclear magnetic resonance technique. In order to estimate the basal permeability the maximal inhibition of water diffusion was induced by exposure of red blood cells to p-chloromercuribenzene sulfonate (PCMBS) under various conditions (concentration, duration, temperature). The lowest values of P were around 0.7×10−3 cm s−1 at 10°C, 1.2×10−3 cm s−1 at 15°C, 1.4×10−3 cm s−1 at 20°C, 1.8×10−3 cm s−1 at 25°C, 2.1×10−3 cm s−1 at 30°C and 3.5×10−3 cm s−1 at 37°C. The mean value of the activation energy of water diffusion (Ea,d) was 25 kJ/mol for control and 43.7 kJ/mol for PCMBS-inhibited erythrocytes. The values of P and Ea,d obtained after induction of maximal inhibition of water diffusion by PCMBS can be taken as references for the basal permeability to water of the human red blood cell membrane.
Mosquito-borne viruses (moboviruses) are of growing importance in many countries of Europe. In Ro... more Mosquito-borne viruses (moboviruses) are of growing importance in many countries of Europe. In Romania and especially in the Danube Delta Biosphere Reserve (DDBR), mosquito and mobovirus surveillance are not performed on a regular basis. However, this type of study is crucially needed to evaluate the risk of pathogen transmission, to understand the ecology of emerging moboviruses, or to plan vector control programmes. We initiated a longitudinal mosquito surveillance study with carbon dioxide-baited Heavy Duty Encephalitis Vector Survey traps at four sampling sites to analyse the spatio-temporal pattern of the (i) mosquito species composition and diversity, (ii) functional groups of mosquitoes (oviposition sites, overwintering stage, and number of generations), and (iii) the occurrence of potential West Nile virus (WNV) vectors. During 2014, a total of 240,546 female mosquitoes were collected. All species were identified using morphological characteristics and further confirmed by m...
... 1999. Amy-loid (In press). 3. Jumblatt, J., V. Schlup, and M. Burger. 1980. Biochemistry 19: ... more ... 1999. Amy-loid (In press). 3. Jumblatt, J., V. Schlup, and M. Burger. 1980. Biochemistry 19: 1038-1042. 4. Misevic, G., and M. Burger. 1986. J. Biol. Chem. 261: 2853-2859. 5. Yang, B., L. Zhang, and E. Turley. 1993. J. Biol. Chem. 268: 8617-8623. 6. Fernandez-Busquets, X., R ...
This paper shows that the correlation characteri stics of coding length sequences for several str... more This paper shows that the correlation characteri stics of coding length sequences for several strains of E. coli have a non-random organization. Although modest, this correlation at the level of the chromosome is statistically significan t. The methods of analysis included spectral analysis, detrended fluctuation analysis, Hurst exp onent and correlation dimension. The methods were checked up against series of data with well-known c haracteristics. It is shown that the equivalent literature data are in serious error. Our analysis suggests that the organization of coding length sequences seems to be non-uniform, therefore, the e valuation as a simple long-range correlated system is only an approximation. The coding sequences are definitely not dynamic systems.
Blood cultures are one of the most important investigation methods in medical bacteriology. Rapid... more Blood cultures are one of the most important investigation methods in medical bacteriology. Rapid identification of pathogens and determination of the relevant antibiotic sensitivity profiles are an important step for effective treatment with appropriate antimicrobial agent. Using blood cultures the prognosis of patients can be improved, reducing the acquisition of the antibiotic resistance determinants by bacteria and lowering the total cost of healthcare. Systemic staphylococcal infections caused by community-acquired and the hospital-acquired strains are one of the major causes of mortality worldwide (1). In the last twenty years the increased number of invasive procedures, the widespread use of broad-spectrum antimicrobial agents leads to the emergence of coagulase-negative staphylococci, Staphylococcus epidermidis in particular (2). In our days automated bacteriological systems allows rapid detection of microbial growth in blood cultures. The BACTEC ® system (Becton Dickinson I...
Summary In order to overcome the crisis of antibiotic resistance, there is an urgent need for alt... more Summary In order to overcome the crisis of antibiotic resistance, there is an urgent need for alternative antibacterial agents that have novel mechanisms of action. FtsZ is an attractive target for antibacterial drug discovery because of its widespread conservation in the bacterial kingdom, its absence in the mitochondria of higher eukaryotes and its known biochemical activity and molecular structure. FtsZ plays an essential role in prokaryotic cell division machinery in which undergoes GTP-dependent polymerization midcell and assembles into the dynamic Z-ring at the site of division. The Z-ring acts to initiate Z-ring contraction to form bacterial daughter cells. Although FtsZ shares structural and functional similarity with eukaryotic tubulin, most of the tubulin/microtubule targeting agents do not affect the dynamic assembly of FtsZ, indicating that FtsZ can be a selective antibacterial target. In this study, we evaluated the immunogenicity in mice of FtsZ protein from Pseudomona...
The water permeability of human erythrocytes has been monitored by nuclear magnetic resonance (NM... more The water permeability of human erythrocytes has been monitored by nuclear magnetic resonance (NMR) before and after treatment of the cells with various sulfhydryl reagents. Preincubation of the cells with N-ethylmaleimide (NEM), a non-inhibitory sulfhydryl reagent, results in a faster and more sensitive inhibition of water exchange by mercurials. The inhibition of water exchange by p-chloromercuribenzene sulfonate (PCMBS) was maximal at a binding of approximately 10 nmol PCMBS per mg protein when non-specific sulfhydryl groups are blocked by NEM. Inhibition by PCMBS has been correlated with the binding of 203Hg to erythrocyte membrane proteins. A significant binding of label to band 3 and the polypeptides in band 4.5 occurs, with approximately 1 mol of mercurial bound per mol of protein. Inhibition of water transport by sulfhydryl reagents does not induce major morphological changes in the cells as assessed by freeze-fracture and scanning electron microscopy.
The water permeability of human red blood cells has been monitored by nuclear magnetic resonance ... more The water permeability of human red blood cells has been monitored by nuclear magnetic resonance (NMR) following exposure to inhibitors of various transport processes across their membranes. No significant inhibition of water diffusion could be detected after the treatment of red blood cells with the anion exchange transport inhibitor dihydro-4,4'-diisothiocyano-stilbene-2,2'-disulfonate (H2DIDS) or the glucose transport inhibitors diallyl-diethyl-stilbestrol (DADES), cytochalasin B, or 30 mM iodoacetamide. It is for the first time that the effects of glucose transport inhibitors has been studied in detail by the NMR approach. A special case proved to be phloretin, an inhibitor of anion, nonelectrolyte and glucose permeability. A small but statistically significant inhibition of water permeability (around 12% at 20 degrees C) was induced by exposure to 2 mM phloretin (for 60 min at 37 degrees C); after a pretreatment of cells with 12 mM N-ethylmaleimide (NEM), for 60 min at ...
The total protein content and the protein fractions were determined in the blood serum and the ce... more The total protein content and the protein fractions were determined in the blood serum and the cerebrospinal fluid (CSF) of chick embryos and foetuses between the 4th and 20th day of incubation and of 2-day-old chickens (by Lowry's method and by polyacrylamide gel electrophoresis respectively). The main results were the following: The total protein content of the CSF increased from 1.8 mg/ml on day 4 to 3.1 mg/ml on day 10. After a slight decrease to 2.6 mg/ml on day 12 no further changes were detected. In the blood serum the total protein content was 4.3 mg/ml on day 4 and 4.7 mg/ml on day 9. Beginning with day 10 it increased constantly to 23.2 mg/ml on day 2 after hatching (daily rate 1-1.2 mg/ml). It results that the "protein barrier" between blood and CSF begins to function after 10-12 days of incubation. Of the protein fractions determined, the light fraction I in the CSF represents 50 per cent of the similar blood serum fraction (on day 10). As to the heavy frac...
SummaryIn comparison to values obtained in normal-weight normolipenic controls, dilute blood clot... more SummaryIn comparison to values obtained in normal-weight normolipenic controls, dilute blood clot lysis time was found to be prolonged in resting and exercised patients with endogenous hypertriglyceridemia. Lysis time was also prolonged in overweight subjects with only slightly increased serum lipids but it was not significantly changed in type II-a hyperlipoproteinemia. An obvious acceleration of clot lysis was noted in patients with decompensated cirrhosis of the liver. Inclusion of p-chlormercuribenzoate (PCMB) into the diluted blood clot caused an acceleration of lysis time. This effect was particularly obvious with hypertriglyceridemic blood and minimal with blood obtained from cirrhotic patients. Addition of various amounts of heat-defibrinated plasma to blood from cirrhotic patients caused a proportional prolongation of clot lysis time and this effect was greatly diminished in the presence of PCMB. Similar amounts of serum had a much lesser effect than defibrinated plasma. Inhibition of fibrin cross-linking by PCMB was confirmed by sodium dodecylsulfate polyacrylamide gel electrophoresis.The present data complete previous observations concerning a higher plasma factor XIII activity in type II-b and type IV hyperlipoproteinemia and suggest that an increased crosslinking of fibrin might partially explain the deficient thrombolysis of hypertriglyceridemic patients.
Abstract: Increased soil salinity is a major environmental stress factor for many plants, and lim... more Abstract: Increased soil salinity is a major environmental stress factor for many plants, and limits crop yields. Lettuce is a frequently grown, moderately salt-sensitive crop plant, with many different cultivars. Their physiological diversity when exposed to salt stress enables ...
The characteristics of water diffusional permeability (P) of human red blood cells were studied o... more The characteristics of water diffusional permeability (P) of human red blood cells were studied on isolated erythrocytes by a doping nuclear magnetic resonance technique. In order to estimate the basal permeability the maximal inhibition of water diffusion was induced by exposure of red blood cells to p-chloromercuribenzene sulfonate (PCMBS) under various conditions (concentration, duration, temperature). The lowest values of P were around 0.7×10−3 cm s−1 at 10°C, 1.2×10−3 cm s−1 at 15°C, 1.4×10−3 cm s−1 at 20°C, 1.8×10−3 cm s−1 at 25°C, 2.1×10−3 cm s−1 at 30°C and 3.5×10−3 cm s−1 at 37°C. The mean value of the activation energy of water diffusion (Ea,d) was 25 kJ/mol for control and 43.7 kJ/mol for PCMBS-inhibited erythrocytes. The values of P and Ea,d obtained after induction of maximal inhibition of water diffusion by PCMBS can be taken as references for the basal permeability to water of the human red blood cell membrane.
Mosquito-borne viruses (moboviruses) are of growing importance in many countries of Europe. In Ro... more Mosquito-borne viruses (moboviruses) are of growing importance in many countries of Europe. In Romania and especially in the Danube Delta Biosphere Reserve (DDBR), mosquito and mobovirus surveillance are not performed on a regular basis. However, this type of study is crucially needed to evaluate the risk of pathogen transmission, to understand the ecology of emerging moboviruses, or to plan vector control programmes. We initiated a longitudinal mosquito surveillance study with carbon dioxide-baited Heavy Duty Encephalitis Vector Survey traps at four sampling sites to analyse the spatio-temporal pattern of the (i) mosquito species composition and diversity, (ii) functional groups of mosquitoes (oviposition sites, overwintering stage, and number of generations), and (iii) the occurrence of potential West Nile virus (WNV) vectors. During 2014, a total of 240,546 female mosquitoes were collected. All species were identified using morphological characteristics and further confirmed by m...
... 1999. Amy-loid (In press). 3. Jumblatt, J., V. Schlup, and M. Burger. 1980. Biochemistry 19: ... more ... 1999. Amy-loid (In press). 3. Jumblatt, J., V. Schlup, and M. Burger. 1980. Biochemistry 19: 1038-1042. 4. Misevic, G., and M. Burger. 1986. J. Biol. Chem. 261: 2853-2859. 5. Yang, B., L. Zhang, and E. Turley. 1993. J. Biol. Chem. 268: 8617-8623. 6. Fernandez-Busquets, X., R ...
This paper shows that the correlation characteri stics of coding length sequences for several str... more This paper shows that the correlation characteri stics of coding length sequences for several strains of E. coli have a non-random organization. Although modest, this correlation at the level of the chromosome is statistically significan t. The methods of analysis included spectral analysis, detrended fluctuation analysis, Hurst exp onent and correlation dimension. The methods were checked up against series of data with well-known c haracteristics. It is shown that the equivalent literature data are in serious error. Our analysis suggests that the organization of coding length sequences seems to be non-uniform, therefore, the e valuation as a simple long-range correlated system is only an approximation. The coding sequences are definitely not dynamic systems.
Blood cultures are one of the most important investigation methods in medical bacteriology. Rapid... more Blood cultures are one of the most important investigation methods in medical bacteriology. Rapid identification of pathogens and determination of the relevant antibiotic sensitivity profiles are an important step for effective treatment with appropriate antimicrobial agent. Using blood cultures the prognosis of patients can be improved, reducing the acquisition of the antibiotic resistance determinants by bacteria and lowering the total cost of healthcare. Systemic staphylococcal infections caused by community-acquired and the hospital-acquired strains are one of the major causes of mortality worldwide (1). In the last twenty years the increased number of invasive procedures, the widespread use of broad-spectrum antimicrobial agents leads to the emergence of coagulase-negative staphylococci, Staphylococcus epidermidis in particular (2). In our days automated bacteriological systems allows rapid detection of microbial growth in blood cultures. The BACTEC ® system (Becton Dickinson I...
Summary In order to overcome the crisis of antibiotic resistance, there is an urgent need for alt... more Summary In order to overcome the crisis of antibiotic resistance, there is an urgent need for alternative antibacterial agents that have novel mechanisms of action. FtsZ is an attractive target for antibacterial drug discovery because of its widespread conservation in the bacterial kingdom, its absence in the mitochondria of higher eukaryotes and its known biochemical activity and molecular structure. FtsZ plays an essential role in prokaryotic cell division machinery in which undergoes GTP-dependent polymerization midcell and assembles into the dynamic Z-ring at the site of division. The Z-ring acts to initiate Z-ring contraction to form bacterial daughter cells. Although FtsZ shares structural and functional similarity with eukaryotic tubulin, most of the tubulin/microtubule targeting agents do not affect the dynamic assembly of FtsZ, indicating that FtsZ can be a selective antibacterial target. In this study, we evaluated the immunogenicity in mice of FtsZ protein from Pseudomona...
The water permeability of human erythrocytes has been monitored by nuclear magnetic resonance (NM... more The water permeability of human erythrocytes has been monitored by nuclear magnetic resonance (NMR) before and after treatment of the cells with various sulfhydryl reagents. Preincubation of the cells with N-ethylmaleimide (NEM), a non-inhibitory sulfhydryl reagent, results in a faster and more sensitive inhibition of water exchange by mercurials. The inhibition of water exchange by p-chloromercuribenzene sulfonate (PCMBS) was maximal at a binding of approximately 10 nmol PCMBS per mg protein when non-specific sulfhydryl groups are blocked by NEM. Inhibition by PCMBS has been correlated with the binding of 203Hg to erythrocyte membrane proteins. A significant binding of label to band 3 and the polypeptides in band 4.5 occurs, with approximately 1 mol of mercurial bound per mol of protein. Inhibition of water transport by sulfhydryl reagents does not induce major morphological changes in the cells as assessed by freeze-fracture and scanning electron microscopy.
The water permeability of human red blood cells has been monitored by nuclear magnetic resonance ... more The water permeability of human red blood cells has been monitored by nuclear magnetic resonance (NMR) following exposure to inhibitors of various transport processes across their membranes. No significant inhibition of water diffusion could be detected after the treatment of red blood cells with the anion exchange transport inhibitor dihydro-4,4'-diisothiocyano-stilbene-2,2'-disulfonate (H2DIDS) or the glucose transport inhibitors diallyl-diethyl-stilbestrol (DADES), cytochalasin B, or 30 mM iodoacetamide. It is for the first time that the effects of glucose transport inhibitors has been studied in detail by the NMR approach. A special case proved to be phloretin, an inhibitor of anion, nonelectrolyte and glucose permeability. A small but statistically significant inhibition of water permeability (around 12% at 20 degrees C) was induced by exposure to 2 mM phloretin (for 60 min at 37 degrees C); after a pretreatment of cells with 12 mM N-ethylmaleimide (NEM), for 60 min at ...
The total protein content and the protein fractions were determined in the blood serum and the ce... more The total protein content and the protein fractions were determined in the blood serum and the cerebrospinal fluid (CSF) of chick embryos and foetuses between the 4th and 20th day of incubation and of 2-day-old chickens (by Lowry's method and by polyacrylamide gel electrophoresis respectively). The main results were the following: The total protein content of the CSF increased from 1.8 mg/ml on day 4 to 3.1 mg/ml on day 10. After a slight decrease to 2.6 mg/ml on day 12 no further changes were detected. In the blood serum the total protein content was 4.3 mg/ml on day 4 and 4.7 mg/ml on day 9. Beginning with day 10 it increased constantly to 23.2 mg/ml on day 2 after hatching (daily rate 1-1.2 mg/ml). It results that the "protein barrier" between blood and CSF begins to function after 10-12 days of incubation. Of the protein fractions determined, the light fraction I in the CSF represents 50 per cent of the similar blood serum fraction (on day 10). As to the heavy frac...
SummaryIn comparison to values obtained in normal-weight normolipenic controls, dilute blood clot... more SummaryIn comparison to values obtained in normal-weight normolipenic controls, dilute blood clot lysis time was found to be prolonged in resting and exercised patients with endogenous hypertriglyceridemia. Lysis time was also prolonged in overweight subjects with only slightly increased serum lipids but it was not significantly changed in type II-a hyperlipoproteinemia. An obvious acceleration of clot lysis was noted in patients with decompensated cirrhosis of the liver. Inclusion of p-chlormercuribenzoate (PCMB) into the diluted blood clot caused an acceleration of lysis time. This effect was particularly obvious with hypertriglyceridemic blood and minimal with blood obtained from cirrhotic patients. Addition of various amounts of heat-defibrinated plasma to blood from cirrhotic patients caused a proportional prolongation of clot lysis time and this effect was greatly diminished in the presence of PCMB. Similar amounts of serum had a much lesser effect than defibrinated plasma. Inhibition of fibrin cross-linking by PCMB was confirmed by sodium dodecylsulfate polyacrylamide gel electrophoresis.The present data complete previous observations concerning a higher plasma factor XIII activity in type II-b and type IV hyperlipoproteinemia and suggest that an increased crosslinking of fibrin might partially explain the deficient thrombolysis of hypertriglyceridemic patients.
Abstract: Increased soil salinity is a major environmental stress factor for many plants, and lim... more Abstract: Increased soil salinity is a major environmental stress factor for many plants, and limits crop yields. Lettuce is a frequently grown, moderately salt-sensitive crop plant, with many different cultivars. Their physiological diversity when exposed to salt stress enables ...
Uploads