This work reviews the literature of chiral capillary electrokinetic chromatography from January 2... more This work reviews the literature of chiral capillary electrokinetic chromatography from January 2016 to March 2021. This is done to explore the state-of-the-art approach and recent developments carried out in this field. The separation principle of the technique is described and supported with simple graphical illustrations, showing migration under normal and reversed polarity modes of the separation voltage. The most relevant applications of the technique for enantioseparation of drugs and other enantiomeric molecules in different fields using chiral selectors in single, dual, or multiple systems are highlighted. Measures to improve the detection sensitivity of chiral capillary electrokinetic chromatography with UV detector are discussed, and the alternative aspects are explored, besides special emphases to hyphenation compatibility to mass spectrometry. Partial filling and counter migration techniques are described. Indirect identification of the separated enantiomers and the dete...
The design of experiments (DoE) is one of the quality-by-design tools valued in analytical method... more The design of experiments (DoE) is one of the quality-by-design tools valued in analytical method development, not only for cost reduction and time effectiveness, but also for enabling analytical method control and understanding via a systematic workflow, leading to analytical methods with built-in quality. This work aimed at using DoE to enhance method understanding for a developed UHPLC enantioseparation of terbutaline (TER), a model chiral drug, and to define quality assurance parameters associated with using chiral mobile phase additives (CMPA). Within a response surface methodology workflow, the effect of different factors on both chiral resolution and retention was screened and optimized using Plackett-Burman and central composite designs, respectively, followed by multivariate mathematical modeling. This study was able to delimit method robustness and elucidate enantiorecognition mechanisms involved in interactions of TER with the chiral modifiers. Among many CMPAs, successfu...
Only a fraction of the Biomphalaria and Bulinus snail community shows patent infection with schis... more Only a fraction of the Biomphalaria and Bulinus snail community shows patent infection with schistosomes despite continuous exposure to the parasite, indicating that a substantial proportion of snails may resist infection. Accordingly, exterminating the schistosome intermediate snail hosts in transmission foci in habitats that may extend to kilometres is cost-prohibitive and damaging to the ecological equilibrium and quality of water and may be superfluous. It may be more cost effective with risk less ecological damage to focus on discovering the parameters governing snail susceptibility and resistance to schistosome infection. Therefore, laboratory bred Biomphalaria alexandrina and Bulinus truncatus snails were exposed to miracidia of laboratory-maintained Schistosoma mansoni and S. haematobium, respectively. Snails were examined for presence or lack of infection association with soft tissue and hemolymph content of proteins, cholesterol, and triglycerides, evaluated using standard...
Cardiovascular diseases remain a major public health burden worldwide. It was reported that vitam... more Cardiovascular diseases remain a major public health burden worldwide. It was reported that vitamin D protects the cardiovascular system through several mechanisms mainly by hindering atherosclerosis development. Genetic variations in vitamin D metabolic pathway were found to affect vitamin D levels. This study aimed at investigating the association between single nucleotide polymorphisms in genes involved in vitamin D metabolism, CYP27B and CYP24A1; 25-hydroxyvitamin D (25(OH)D) levels; and susceptibility to acute coronary syndrome (ACS). One hundred and eighty-five patients and 138 healthy controls were recruited. CYP24A1 rs2762939 was genotyped using fast real-time PCR, while CYP24A1 rs4809960 and CYP27B1 rs703842 were genotyped using polymerase chain reaction followed by restriction fragment length polymorphism (PCR–RFLP). 25(OH)D3 and 25(OH)D2 levels were measured using ultra-performance liquid chromatography tandem mass spectrum. Vitamin D level was significantly lower in pati...
Introduction It is still unclear in the literature whether low vitamin D levels play a role in th... more Introduction It is still unclear in the literature whether low vitamin D levels play a role in the pathogenesis of polycystic ovary syndrome (PCOS), especially with respect to the regulation of anti-Müllerian hormone (AMH). Therefore, we aimed to investigate whether there could be a relationship between vitamin D deficiency status and PCOS. Materials and Methods A total of 146 infertile women were divided into two groups according to their ovarian reserve patterns: (i) normal (NOR), and (ii) high (PCOS). The participants were also categorized into two groups according to vitamin D concentrations: (i) Group A 0.005). Only the NOR group showed a significant though moderate negative correlation between 25(OH)D levels and anthropometric parameters. AMH levels were not correlated with 25(OH)D levels in the NOR or the PCOS group (r = − 0.112, p = 0.008; r = 0.027, p = 0.836). Multivariate regression analysis showed no impact of 25(OH)D on other study parameters. Only AMH measurements wer...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 5, 2019
Multivariate strategy was applied for setting a fluorescent technique for the determination of th... more Multivariate strategy was applied for setting a fluorescent technique for the determination of three fluoroquinolones: norfloxacin (NOR), levofloxacin (LEV) and lomefloxacin (LOM) in their pure powder and dosage forms. Based on their known interaction with lanthanides, and augmented fluorescence intensity obtained by antenna effect at λ/λ = 314/553, 312/553 and 310/556 for NOR, LEV and LOM, respectively, the current research was scrutinized. Four continuous factors were selected for study in the screening step by means of Plackett-Burman Design, where temperature factor was excluded for being non-significant and the other factors as volume of metal ion solution, pH and reaction time were evaluated through Central Composite Design. 3-D surfaces demonstrations and 2-D contour plots designated the factors interactions followed by optimization plots, which defined the best blend for factors conjunction. pH factor was the chief motor force affecting the response as the number of coordina...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 5, 2019
A chemometrically optimized procedure has been developed for the determination of isoprenaline (I... more A chemometrically optimized procedure has been developed for the determination of isoprenaline (ISO) in the parent substance as well as in its respective pharmaceutical preparation. It is worth mentioning that although spectroscopic determination of Isoprenaline metal complexes has been described in literature, yet, no methods for the quantification of Isoprenaline with Samarium nor any other lanthanide metal have been reported. Fractional factorial design (FFD) was implemented in the initial screening procedure of the four designated factors, namely, reaction time (RT), metal volume (MV), pH and temperature (T) followed by Response Surface Methodology (RSM) optimization tool performed by the aid of Box Behnken design (BBD).The proposed techniques are based on a multivariate approach where a complexation reaction between Isoprenaline (ISO) and Samarium III (Sm) metal was exploited for the first time to synthesize novel fluorescence and absorbance probes of ISO-Sm. Maximum fluorescen...
Journal of clinical and translational hepatology, Dec 28, 2016
Aims: To examine the regulation of SREBP-1c and CAV1 by microRNA-29a (miR-29a) in cells infected ... more Aims: To examine the regulation of SREBP-1c and CAV1 by microRNA-29a (miR-29a) in cells infected with hepatitis C virus (HCV) in an attempt to control HCV-induced non-alcoholic fatty liver disease. Methods: In order to examine the manipulation of SREBP-1c and CAV1 by miR-29a, oleic acid (OA)-treated JFH-I-infected Huh-7 cells were used. OA was added 24 h post-transfection and gene expression was investigated by qRT-PCR at 48 h post treatment. The functional impact of the observed alteration in SREBP-1c and CAV1 expression was analyzed by examining lipid droplet (LD) and triglyceride (TG) content at 72 h post-OA treatment using light microscopy and spectrophotometry, respectively. Viral load was quantified by qRT-PCR at 72 h post-transfection. Results: OA treatment induced the expression of miR-29a and SREBP-1c, as compared to untreated cells. Forced miR-29a expression led to a significant up-regulation of SREBP-1c as well as CAV1 compared to mock untransfected cells. Ectopic express...
Baclofen, a specific GABAB-receptor agonist, has successfully been used for decades for the treat... more Baclofen, a specific GABAB-receptor agonist, has successfully been used for decades for the treatment of spastic disorders. However, the fraction of an oral or intravenous dose that reaches the CNS is negligible, while intrathecal dosing provides direct biophase access and yields effective CNS-levels, as indicated by the respective cerebrospinal fluid concentrations. This implies that baclofen does not sufficiently permeate through the blood-brain-barrier. Lipophilic ester prodrugs exhibit a considerably higher membrane permeability than parent baclofen. Yet, since ester prodrugs of baclofen are not readily cleaved in vivo and were found to be subject to exsorptive transport, alternative prodrug concepts were evaluated. E.g., methyl 4-(tert-butoxycarbonyl amino) 3-(4chlorophenyl) butanoate (baclofen methyl carbamate) was synthesized and its solubility and log P were evaluated as bio-relevant parameters. Baclofen methyl carbamate was then tested vs. baclofen with respect to the obtai...
An isocratic, rapid and reproducible high performance liquid chromatographic (HPLC) method for qu... more An isocratic, rapid and reproducible high performance liquid chromatographic (HPLC) method for quantitative determination of chlorphenoxamine hydrochloride (CPHX), caffeine (CAFF) and 8- hlorotheophylline (CTHE) has been adopted. The optimal conditions for separation and quantitative determination of these compounds were a normal phase mode chromatography and isocratic elution at ambient temperature. A silica column and a mobile phase consisted of ethyl acetate - methanol (50:50 v/v) / triethylamine pH 9, have been used at a flow rate of 1 ml min-1. The components of column effluent were monitored by UV detector at 254 nm. The retention times (tR) for CPHX, CAFF and CTHE were 6.15, 4.23 and 2.97 min, respectively. The linearity range for CPHX, CAFF and CTHE were 37.5 - 725 μg ml-1, 0.75 - 48 μg ml-1 and 0.1 - 40 μg ml-1, respectively. The mean accuracy ± % RSD for CPHX, CAFF and CTHE were 100.06 ± 0.47, 99.43 ± 0.60 and 100.65 ± 1.25, respectively. The results obtained by the recove...
Vitamin D deficiency is one of the most globally abundant problems with approximately 1 billion p... more Vitamin D deficiency is one of the most globally abundant problems with approximately 1 billion people affected by it worldwide. To exemplify the importance of directing medical attention to this phenomenon, one should be aware of its association not only to calcemic diseases, but to enigmatic diseases as well such as cancers, of various forms, and autoimmune diseases. Establishment of an internationally agreed upon technique for this task is an assignment that has long been contemplated as a burdensome one for many reasons among which is the massive variability in the results generated by the different commercially available assays. On the basis that HPLC techniques have been pondered as the “gold standard” for the assessment of vitamin D status, the aim of this study was to utilize DryLab® to develop a robust method to separate both forms of vitamin D and their corresponding 25-Hydroxyvitamin D metabolites in a commercially appealing run-time to provide a good enough motive for cl...
This work reviews the literature of chiral capillary electrokinetic chromatography from January 2... more This work reviews the literature of chiral capillary electrokinetic chromatography from January 2016 to March 2021. This is done to explore the state-of-the-art approach and recent developments carried out in this field. The separation principle of the technique is described and supported with simple graphical illustrations, showing migration under normal and reversed polarity modes of the separation voltage. The most relevant applications of the technique for enantioseparation of drugs and other enantiomeric molecules in different fields using chiral selectors in single, dual, or multiple systems are highlighted. Measures to improve the detection sensitivity of chiral capillary electrokinetic chromatography with UV detector are discussed, and the alternative aspects are explored, besides special emphases to hyphenation compatibility to mass spectrometry. Partial filling and counter migration techniques are described. Indirect identification of the separated enantiomers and the dete...
The design of experiments (DoE) is one of the quality-by-design tools valued in analytical method... more The design of experiments (DoE) is one of the quality-by-design tools valued in analytical method development, not only for cost reduction and time effectiveness, but also for enabling analytical method control and understanding via a systematic workflow, leading to analytical methods with built-in quality. This work aimed at using DoE to enhance method understanding for a developed UHPLC enantioseparation of terbutaline (TER), a model chiral drug, and to define quality assurance parameters associated with using chiral mobile phase additives (CMPA). Within a response surface methodology workflow, the effect of different factors on both chiral resolution and retention was screened and optimized using Plackett-Burman and central composite designs, respectively, followed by multivariate mathematical modeling. This study was able to delimit method robustness and elucidate enantiorecognition mechanisms involved in interactions of TER with the chiral modifiers. Among many CMPAs, successfu...
Only a fraction of the Biomphalaria and Bulinus snail community shows patent infection with schis... more Only a fraction of the Biomphalaria and Bulinus snail community shows patent infection with schistosomes despite continuous exposure to the parasite, indicating that a substantial proportion of snails may resist infection. Accordingly, exterminating the schistosome intermediate snail hosts in transmission foci in habitats that may extend to kilometres is cost-prohibitive and damaging to the ecological equilibrium and quality of water and may be superfluous. It may be more cost effective with risk less ecological damage to focus on discovering the parameters governing snail susceptibility and resistance to schistosome infection. Therefore, laboratory bred Biomphalaria alexandrina and Bulinus truncatus snails were exposed to miracidia of laboratory-maintained Schistosoma mansoni and S. haematobium, respectively. Snails were examined for presence or lack of infection association with soft tissue and hemolymph content of proteins, cholesterol, and triglycerides, evaluated using standard...
Cardiovascular diseases remain a major public health burden worldwide. It was reported that vitam... more Cardiovascular diseases remain a major public health burden worldwide. It was reported that vitamin D protects the cardiovascular system through several mechanisms mainly by hindering atherosclerosis development. Genetic variations in vitamin D metabolic pathway were found to affect vitamin D levels. This study aimed at investigating the association between single nucleotide polymorphisms in genes involved in vitamin D metabolism, CYP27B and CYP24A1; 25-hydroxyvitamin D (25(OH)D) levels; and susceptibility to acute coronary syndrome (ACS). One hundred and eighty-five patients and 138 healthy controls were recruited. CYP24A1 rs2762939 was genotyped using fast real-time PCR, while CYP24A1 rs4809960 and CYP27B1 rs703842 were genotyped using polymerase chain reaction followed by restriction fragment length polymorphism (PCR–RFLP). 25(OH)D3 and 25(OH)D2 levels were measured using ultra-performance liquid chromatography tandem mass spectrum. Vitamin D level was significantly lower in pati...
Introduction It is still unclear in the literature whether low vitamin D levels play a role in th... more Introduction It is still unclear in the literature whether low vitamin D levels play a role in the pathogenesis of polycystic ovary syndrome (PCOS), especially with respect to the regulation of anti-Müllerian hormone (AMH). Therefore, we aimed to investigate whether there could be a relationship between vitamin D deficiency status and PCOS. Materials and Methods A total of 146 infertile women were divided into two groups according to their ovarian reserve patterns: (i) normal (NOR), and (ii) high (PCOS). The participants were also categorized into two groups according to vitamin D concentrations: (i) Group A 0.005). Only the NOR group showed a significant though moderate negative correlation between 25(OH)D levels and anthropometric parameters. AMH levels were not correlated with 25(OH)D levels in the NOR or the PCOS group (r = − 0.112, p = 0.008; r = 0.027, p = 0.836). Multivariate regression analysis showed no impact of 25(OH)D on other study parameters. Only AMH measurements wer...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 5, 2019
Multivariate strategy was applied for setting a fluorescent technique for the determination of th... more Multivariate strategy was applied for setting a fluorescent technique for the determination of three fluoroquinolones: norfloxacin (NOR), levofloxacin (LEV) and lomefloxacin (LOM) in their pure powder and dosage forms. Based on their known interaction with lanthanides, and augmented fluorescence intensity obtained by antenna effect at λ/λ = 314/553, 312/553 and 310/556 for NOR, LEV and LOM, respectively, the current research was scrutinized. Four continuous factors were selected for study in the screening step by means of Plackett-Burman Design, where temperature factor was excluded for being non-significant and the other factors as volume of metal ion solution, pH and reaction time were evaluated through Central Composite Design. 3-D surfaces demonstrations and 2-D contour plots designated the factors interactions followed by optimization plots, which defined the best blend for factors conjunction. pH factor was the chief motor force affecting the response as the number of coordina...
Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy, Jan 5, 2019
A chemometrically optimized procedure has been developed for the determination of isoprenaline (I... more A chemometrically optimized procedure has been developed for the determination of isoprenaline (ISO) in the parent substance as well as in its respective pharmaceutical preparation. It is worth mentioning that although spectroscopic determination of Isoprenaline metal complexes has been described in literature, yet, no methods for the quantification of Isoprenaline with Samarium nor any other lanthanide metal have been reported. Fractional factorial design (FFD) was implemented in the initial screening procedure of the four designated factors, namely, reaction time (RT), metal volume (MV), pH and temperature (T) followed by Response Surface Methodology (RSM) optimization tool performed by the aid of Box Behnken design (BBD).The proposed techniques are based on a multivariate approach where a complexation reaction between Isoprenaline (ISO) and Samarium III (Sm) metal was exploited for the first time to synthesize novel fluorescence and absorbance probes of ISO-Sm. Maximum fluorescen...
Journal of clinical and translational hepatology, Dec 28, 2016
Aims: To examine the regulation of SREBP-1c and CAV1 by microRNA-29a (miR-29a) in cells infected ... more Aims: To examine the regulation of SREBP-1c and CAV1 by microRNA-29a (miR-29a) in cells infected with hepatitis C virus (HCV) in an attempt to control HCV-induced non-alcoholic fatty liver disease. Methods: In order to examine the manipulation of SREBP-1c and CAV1 by miR-29a, oleic acid (OA)-treated JFH-I-infected Huh-7 cells were used. OA was added 24 h post-transfection and gene expression was investigated by qRT-PCR at 48 h post treatment. The functional impact of the observed alteration in SREBP-1c and CAV1 expression was analyzed by examining lipid droplet (LD) and triglyceride (TG) content at 72 h post-OA treatment using light microscopy and spectrophotometry, respectively. Viral load was quantified by qRT-PCR at 72 h post-transfection. Results: OA treatment induced the expression of miR-29a and SREBP-1c, as compared to untreated cells. Forced miR-29a expression led to a significant up-regulation of SREBP-1c as well as CAV1 compared to mock untransfected cells. Ectopic express...
Baclofen, a specific GABAB-receptor agonist, has successfully been used for decades for the treat... more Baclofen, a specific GABAB-receptor agonist, has successfully been used for decades for the treatment of spastic disorders. However, the fraction of an oral or intravenous dose that reaches the CNS is negligible, while intrathecal dosing provides direct biophase access and yields effective CNS-levels, as indicated by the respective cerebrospinal fluid concentrations. This implies that baclofen does not sufficiently permeate through the blood-brain-barrier. Lipophilic ester prodrugs exhibit a considerably higher membrane permeability than parent baclofen. Yet, since ester prodrugs of baclofen are not readily cleaved in vivo and were found to be subject to exsorptive transport, alternative prodrug concepts were evaluated. E.g., methyl 4-(tert-butoxycarbonyl amino) 3-(4chlorophenyl) butanoate (baclofen methyl carbamate) was synthesized and its solubility and log P were evaluated as bio-relevant parameters. Baclofen methyl carbamate was then tested vs. baclofen with respect to the obtai...
An isocratic, rapid and reproducible high performance liquid chromatographic (HPLC) method for qu... more An isocratic, rapid and reproducible high performance liquid chromatographic (HPLC) method for quantitative determination of chlorphenoxamine hydrochloride (CPHX), caffeine (CAFF) and 8- hlorotheophylline (CTHE) has been adopted. The optimal conditions for separation and quantitative determination of these compounds were a normal phase mode chromatography and isocratic elution at ambient temperature. A silica column and a mobile phase consisted of ethyl acetate - methanol (50:50 v/v) / triethylamine pH 9, have been used at a flow rate of 1 ml min-1. The components of column effluent were monitored by UV detector at 254 nm. The retention times (tR) for CPHX, CAFF and CTHE were 6.15, 4.23 and 2.97 min, respectively. The linearity range for CPHX, CAFF and CTHE were 37.5 - 725 μg ml-1, 0.75 - 48 μg ml-1 and 0.1 - 40 μg ml-1, respectively. The mean accuracy ± % RSD for CPHX, CAFF and CTHE were 100.06 ± 0.47, 99.43 ± 0.60 and 100.65 ± 1.25, respectively. The results obtained by the recove...
Vitamin D deficiency is one of the most globally abundant problems with approximately 1 billion p... more Vitamin D deficiency is one of the most globally abundant problems with approximately 1 billion people affected by it worldwide. To exemplify the importance of directing medical attention to this phenomenon, one should be aware of its association not only to calcemic diseases, but to enigmatic diseases as well such as cancers, of various forms, and autoimmune diseases. Establishment of an internationally agreed upon technique for this task is an assignment that has long been contemplated as a burdensome one for many reasons among which is the massive variability in the results generated by the different commercially available assays. On the basis that HPLC techniques have been pondered as the “gold standard” for the assessment of vitamin D status, the aim of this study was to utilize DryLab® to develop a robust method to separate both forms of vitamin D and their corresponding 25-Hydroxyvitamin D metabolites in a commercially appealing run-time to provide a good enough motive for cl...
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