38 results on '"Hassan HY"'
Search Results
2. Studies on synthesis of some quinazolinones bearing different heterocyclic moieties with expected biological activity
- Author
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Hassan, HY, Ismaiel, AA, and El-Sherief, HAH
- Published
- 1991
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3. Effect of three different root canal sealants on human dental pulp stem cells.
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Alfahlawy A, Selim MAA, and Hassan HY
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- Humans, Cells, Cultured, Cell Survival drug effects, Dental Pulp cytology, Dental Pulp drug effects, Stem Cells drug effects, Stem Cells cytology, Stem Cells metabolism, Root Canal Filling Materials pharmacology, Cell Proliferation drug effects
- Abstract
The cytotoxic effects of three root canal sealers with different bases on human dental pulp stem cells were assessed in this study using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test. The cytotoxic effects of three root canal sealers with different bases on human dental pulp stem cells (DPSCs) were assessed in this study using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test. The cytotoxicity of the sealers was tested after one, 4, and 7 d. Human dental pulp stem cell proliferation was concluded using an MTT assay. Cells not treated with sealer extract were used as controls. The absorption levels were measured using an Eliza spectrophotometer. P was set at 0.05 when the percentage of cell proliferation was matched between groups and observation times using one-way analysis of variance (ANOVA).During the second passage (P2), human dental pulp stem cells displayed a single morphological and phenotypic trait, with fibroblast morphology being the most common. There were no appreciable variations between the four groups after a day. There was a notable variation in the average percentage of cell proliferation between the groups after 4 and 7 days. The control group had the highest percentage, followed by the GuttaFlow Bioseal group, the Well Root St group, and the AH-Plus group, which had the lowest percentage. For every sealing group, after one day, the highest mean percentage of cell proliferation was recorded, followed by day four, and after day seven, the lowest mean percentage. The observation periods showed minimal cytotoxic effects of GuttaFlow Bioseal, whereas AH-Plus was the most cytotoxic to human dental pulp stem cells. The highest mean percentage of cell proliferation for all sealers was recorded on day one., (© 2024. The Author(s).)
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- 2024
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4. Charting a landmark-driven path forward for population genetics and ancient DNA research in Africa.
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Sawchuk EA, Sirak KA, Manthi FK, Ndiema EK, Ogola CA, Prendergast ME, Reich D, Aluvaala E, Ayodo G, Badji L, Bird N, Black W, Fregel R, Gachihi N, Gibbon VE, Gidna A, Goldstein ST, Hamad R, Hassan HY, Hayes VM, Hellenthal G, Kebede S, Kurewa A, Kusimba C, Kyazike E, Lane PJ, MacEachern S, Massilani D, Mbua E, Morris AG, Mutinda C, M'Mbogori FN, Reynolds AW, Tishkoff S, Vilar M, and Yimer G
- Subjects
- Humans, Africa, Genomics, Black People genetics, DNA, Ancient analysis, Genetics, Population
- Abstract
Population history-focused DNA and ancient DNA (aDNA) research in Africa has dramatically increased in the past decade, enabling increasingly fine-scale investigations into the continent's past. However, while international interest in human genomics research in Africa grows, major structural barriers limit the ability of African scholars to lead and engage in such research and impede local communities from partnering with researchers and benefitting from research outcomes. Because conversations about research on African people and their past are often held outside Africa and exclude African voices, an important step for African DNA and aDNA research is moving these conversations to the continent. In May 2023 we held the DNAirobi workshop in Nairobi, Kenya and here we synthesize what emerged most prominently in our discussions. We propose an ideal vision for population history-focused DNA and aDNA research in Africa in ten years' time and acknowledge that to realize this future, we need to chart a path connecting a series of "landmarks" that represent points of consensus in our discussions. These include effective communication across multiple audiences, reframed relationships and capacity building, and action toward structural changes that support science and beyond. We concluded there is no single path to creating an equitable and self-sustaining research ecosystem, but rather many possible routes linking these landmarks. Here we share our diverse perspectives as geneticists, anthropologists, archaeologists, museum curators, and educators to articulate challenges and opportunities for African DNA and aDNA research and share an initial map toward a more inclusive and equitable future., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
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- 2024
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5. Correction: Isolation and characterization of Candida tropicalis B: a promising yeast strain for biodegradation of petroleum oil in marine environments.
- Author
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Hegazy GE, Soliman NA, Farag S, El-Helow ER, Hassan HY, and Abdel-Fattah YR
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- 2024
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6. Biocompatibility of three different root canal sealers, experimental study.
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Alfahlawy A, Selim MAA, and Hassan HY
- Subjects
- Animals, Male, Rats, Analysis of Variance, Drug Combinations, Gutta-Percha adverse effects, Dental Pulp Cavity, Root Canal Filling Materials adverse effects
- Abstract
Objectives: This study was assessed the biocompatibility of three different root canal sealers (Well-Root St, GuttaFlow Bioseal, and AH-Plus) following implantation in rat subcutaneous tissues, using histopathological immunohistochemical analysis., Methods: Four groups of eighty-four male rats each underwent subcutaneous dorsal implantation of a polyethylene tube, either empty or filled. Tissues were collected, fixed, and processed for histological analysis after 7, 15, and 30 d. Slides were photographed and digitally processed to identify lymphocytes and macrophages using Cluster of differentiation 3 (CD3) and cluster of differentiation 68 (CD68) markers, respectively. P was set at 0.05, when lymphocyte and macrophage infiltration was compared between groups and observation times using one-way analysis of variance (ANOVA)., Results: Histopathological analysis of all groups revealed an inflammatory reaction followed by the emergence of a fibrous capsule after 7 days. After 30 days, the thickness of the fibrous capsule and the inflammatory response subsided. CD3 staining for immunohistochemical analysis revealed that the AH-Plus group had the highest mean percentage of lymphocyte infiltration at 7 and 15 days, followed by the Well-Root St, GuttaFlow Bioseal, and Control groups. After 30 days, no discernible difference was observed between the groups in terms of the mean percentage of lymphocyte infiltration. After 7, 15, and 30 days, there was a significant difference in the mean percentage of macrophage infiltration across the groups, as demonstrated by CD68 staining. After 7, 15, and 30 days, the AH-Plus group had the highest mean percentage of macrophage infiltration, followed by the Well-Root St. and GuttaFlow Bioseal groups, while the control group had the lowest mean percentage., Conclusion: All observational periods showed minimal inflammatory reactions to GuttaFlow Bioseal. After subcutaneous tissue implantation in a rat model, the initial inflammatory reactions to Well-Root St and AH-Plus had abated by day 30, and all tested sealers had outstanding biocompatibility., (© 2023. BioMed Central Ltd., part of Springer Nature.)
- Published
- 2023
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7. Evaluation of dental pulp stem cells behavior after odontogenic differentiation induction by three different bioactive materials on two different scaffolds.
- Author
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Ahmed B, Ragab MH, Galhom RA, and Hassan HY
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- Humans, Cell Differentiation, Cell Proliferation, Cells, Cultured, Hydroxyapatites, Bicuspid, Real-Time Polymerase Chain Reaction, Dental Pulp, Odontogenesis genetics, Stem Cells
- Abstract
Background: To study the odontogenic potential of dental pulp stem cells (DPSCs) after induction with three different bioactive materials: activa bioactive (base/liner) (AB), TheraCal LC (TC), and mineral trioxide aggregate (MTA), when combined with two different types of scaffolds., Methods: DPSCs were isolated from freshly extracted premolars of young orthodontic patients, cultured, expanded to passage 4 (P), and characterized by flow cytometric analysis. DPSCs were seeded onto two scaffolds in contact with different materials (AB, TC, and MTA). The first scaffold contained polycaprolactone-nano-chitosan and synthetic hydroxyapatite (PCL-NC-HA), whereas the second scaffold contained polycaprolactone-nano-chitosan and synthetic Mg-substituted hydroxyapatite (PCL-NC-Mg-HA). DPSC viability and proliferation were evaluated at various time points. To assess odontoblastic differentiation, gene expression analysis of dentin sialophosphoprotein (DSPP) by quantitative real-time polymerase chain reaction (qRT-PCR) and morphological changes in cells were performed using inverted microscope phase contrast images and scanning electron microscopy. The fold-change in DSPP between subgroups was compared using a one-way ANOVA. Tukey's test was used to compare the fold-change in DSPP between the two subgroups in multiple comparisons, and P was set at p < 0.05., Results: DSPP expression was significantly higher in the PCL-NC-Mg-HA group than in the PCL-NC-HA group, and scanning electron microscopy revealed a strong attachment of odontoblast-like cells to the scaffold that had a stronger odontogenic differentiation effect on DPSCs than the scaffold that did not contain magnesium. MTA has a significantly higher odontogenic differentiation effect on cultured DPSCs than AB or TC does. The combination of scaffolds and bioactive materials improves DPSCs induction in odontoblast-like cells., Conclusions: The PCL-NC-Mg-HA scaffold showed better odontogenic differentiation effects on cultured DPSCs. Compared to AB and TC, MTA is the most effective bioactive material for inducing the odontogenic differentiation of cultured DPSCs., (© 2023. The Author(s).)
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- 2023
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8. Case report: Homozygous variants of NEB and KLHL40 in two Arab patients with nemaline myopathy.
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Skrypnyk C, Husain AA, Hassan HY, Ahmed J, Darwish A, Almusalam L, Ben Khalaf N, and Al Qashar F
- Abstract
Objective: Nemaline myopathies are a heterogeneous group of congenital myopathies caused by mutations in different genes associated with the structural and functional proteins of thin muscular filaments. Most patients have congenital onset characterized by hypotonia, respiratory issues, and abnormal deep tendon reflexes, which is a phenotype encountered in a wide spectrum of neuromuscular disorders. Whole-exome sequencing (WES) contributes to a faster diagnosis and facilitates genetic counseling. Methods: Here, we report on two Arab patients from consanguineous families diagnosed with nemaline myopathy of different phenotype spectrum severities. Results: Clinical assessment and particular prenatal history raised suspicion of neuromuscular disease. WES identified homozygous variants in NEB and KLHL40 . Muscle biopsy and muscle magnetic resonance imaging studies linked the genetic testing results to the clinical phenotype. The novel variant in the NEB gene resulted in a classical type 2 nemaline myopathy, while the KLHL40 gene variant led to a severe phenotype of nemaline myopathy, type 8. Both patients were identified as having other gene variants with uncertain roles in their complex phenotypes. Conclusions: This study enriches the phenotypic spectrum of nemaline myopathy caused by NEB and KLHL40 variants and highlights the importance of detailed prenatal, neonatal, and infancy assessments of muscular weakness associated with complex systemic features. Variants of uncertain significance in genes associated with nemaline myopathy may be correlated with the phenotype. Early, multidisciplinary intervention can improve the outcome in patients with mild forms of nemaline myopathies. WES is essential for clarifying complex clinical phenotypes encountered in patients from consanguineous families. Targeted carrier screening of extended family members would enable accurate genetic counseling and potential genetic prevention., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Skrypnyk, Husain, Hassan, Ahmed, Darwish, Almusalam, Ben Khalaf and Al Qashar.)
- Published
- 2023
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9. Retreatment of XP-endo Shaper and R-Endo files in curved root canals.
- Author
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Hassan HY, Hadhoud FM, and Mandorah A
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- Humans, Root Canal Obturation, Root Canal Preparation, X-Ray Microtomography, Retreatment, Dental Pulp Cavity diagnostic imaging, Root Canal Filling Materials therapeutic use
- Abstract
Objectives: To compare the retreatment efficiency of XP-endo Shaper and R-Endo files in curved root canals using ImageJ software., Methods: Forty extracted mandibular first molars with curved mesial canals (25°-35°) were chosen. Access cavities, preparation and obturation of root canals were performed. Roots were randomly distributed into two groups corresponding to the retreatment files used. Group 1 retreated with XP-endo Shaper file, and group 2 retreated with R-Endo files. Each root was sectioned and photographed. ImageJ software was used to estimate the percentage of residual filling material that existed on the three root canal segments. Mann-Whitney U and the Kruskal-Wallis tests were used to compare the percentages of residual filling material between the teeth segments (P < .05)., Results: The R-Endo group showed a significantly higher median percentage of residual filling material than the XP-endo Shaper group. In both groups, the coronal segments had the highest median of the residual filling material, followed by the middle and apical segments., Conclusion: XP-endo Shaper is significantly more effective than R-Endo in removing root canal filling materials in the coronal, middle, and apical segments., (© 2023. The Author(s).)
- Published
- 2023
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10. Biofilm elimination from infected root canals using four different single files.
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Hamed SA, Shabayek S, and Hassan HY
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- Humans, Biofilms, Enterococcus faecalis, Pilot Projects, Root Canal Irrigants, Root Canal Therapy, Dental Pulp Cavity microbiology, Root Canal Preparation
- Abstract
Introduction: Enterococcus faecalis (E. faecalis) is the most commonly isolated bacterium from infected root canals. It is found in the form of a biofilm, which makes it more resistant to antimicrobials, and requires optimal chemomechanical strategies to maximize root canal disinfection., Aim: To evaluate the efficacy of 4 different endodontic file systems against E. faecalis biofilm growth in root canals using colony-forming units per milliliter (CFU/mL) and scanning electron microscope (SEM)., Methods: Eighty-five extracted human mandibular premolars with straight root canals and apical diameters not larger than the #15 K-file were randomly selected. After performing a pilot study (n = 15) to determine the ideal incubation period for E. faecalis biofilm development, sixty-five root canals were infected with E. faecalis, incubated for 3 weeks, and then mechanically prepared using one of four single files (XP-endo Shaper, Hyflex EDM, One Curve, and Fanta. AFTM F One) (n = 15). Five infected root canals were excluded for the positive control. Five non-contaminated root canals were included for the negative control. Samples were collected using sterile paper points pre- and post-instrumentation to determine the bacterial load (CFU/mL). Root canals from each group were topographically evaluated at the coronal, middle, and apical segments using scanning electron microscope (SEM). Bacterial reduction data were estimated and statistically analyzed by Kruskal-Wallis and Mann-Whitney U tests (post hoc test) (P ≤ .05)., Results: XP-endo Shaper, Hyflex DEM, and One Curve significantly could eradicate E. faecalis biofilms in infected root canals with no significant difference among them compared to Fanta. AF™ F One., Conclusion: None of the systems were capable of completely eliminating biofilms. XP-endo Shaper, Hyflex EDM, and One Curve mechanically eliminated E. faecalis biofilms compared to Fanta. AF™ F One from infected root canals., (© 2022. The Author(s).)
- Published
- 2022
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11. Molecular cytogenetic and phenotypic characterization of Phelan McDermid and 22q13 duplication syndrome: a case report.
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Khalifa Y, Hassan HY, Weise A, Liehr T, and Alkhayyat H
- Abstract
Background: Phelan-McDermid syndrome (PHMDS) is a rare genetic disorder mostly caused by haploinsufficincy of SHANK3 gene, and characterized by neonatal hypotonia, developmental delay, minor dysmorphic features, seizures and behavior problems. Literature of this syndrome is scanty and confusing, and represents a challenge for pediatricians, in terms of finding the correct diagnoses., Case Presentation: In a postnatal case with hypotonia and dysmorphic features a de novo ring chromosome r(22) leading to in parallel microdeletion and micro duplication in 22q13 was diagnosed by banding cytogenetics, and further characterized in detail by molecular cytogenetic and chromosomal microarray., Conclusion: Here a rare PHMDS case caused by a r(22) is presented. Less than 10 comparable cases are reported in the literature. The present case highlights the importance of conducting genetic counseling and appropriate genetic tests for newborns with mild dysmorphic features., (© 2022. The Author(s).)
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- 2022
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12. Effects of autologous dental pulp stem cells and mineral trioxide aggregate on exposed dogs' dental pulp.
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Hemdan DK, Selim MA, Galhom RA, El Daharawy MH, and Hassan HY
- Abstract
This study evaluated exposed dogs' dental pulp response after direct capping with autologous dental pulp stem cells (DPSCs) and compared the results with MTA (Angelus, Brazil). Sixty teeth from six mongrel dogs were included (n = 60), allocated into four groups; negative control (n = 6), positive control (n = 6), MTA (n = 24), and DPSCs (n = 24). DPSCs were isolated and cultured from extracted first premolars (1premolar/dog). The teeth were prepared for histological and immunohistochemical analyses. Statistical analysis was calculated using ANOVA tests, P ≤ 0.05. MTA induced the formation of an almost complete calcific bridge. DPSCs successfully regenerated the injured pulp and dentin. The comparison between the capping groups and time intervals had a statistically significant effect, as well as, the interaction between the two variables. DPSCs had greater ability in the reparative and regenerative process of dentin and odontoblastic differentiation by having a significantly stronger TGFβ1 expression than MTA., (© 2022 Craniofacial Research Foundation. Published by Elsevier B.V. All rights reserved.)
- Published
- 2022
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13. Case Report: Stem cell therapy in amyotrophic lateral sclerosis.
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Hassan AA, Elkins J, and Hassan HY
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- Cell- and Tissue-Based Therapy adverse effects, Humans, Quality of Life, Amyotrophic Lateral Sclerosis therapy
- Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive motor neuron disease leading to loss of upper and lower motor neurons at both spinal and bulbar levels.
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- 2021
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14. Analysis of HLA gene polymorphisms in East Africans reveals evidence of gene flow in two Semitic populations from Sudan.
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Aamer W, Hassan HY, Nakaoka H, Hosomichi K, Jaeger M, Tahir H, Abdelraheem MH, Netea MG, and Inoue I
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- Arabs genetics, Asian People genetics, Black People genetics, Gene Frequency, Human Migration, Humans, Sudan, Gene Flow, HLA-D Antigens genetics, Polymorphism, Single Nucleotide
- Abstract
Sudan, a northeastern African country, is characterized by high levels of cultural, linguistic, and genetic diversity, which is believed to be affected by continuous migration from neighboring countries. Consistent with such demographic effect, genome-wide SNP data revealed a shared ancestral component among Sudanese Afro-Asiatic speaking groups and non-African populations, mainly from West Asia. Although this component is shared among all Afro-Asiatic speaking groups, the extent of this sharing in Semitic groups, such as Sudanese Arab, is still unknown. Using genotypes of six polymorphic human leukocyte antigen (HLA) genes (i.e., HLA-A, -C, -B, -DRB1, -DQB1, and -DPB1), we examined the genetic structure of eight East African ethnic groups with origins in Sudan, South Sudan, and Ethiopia. We identified informative HLA alleles using principal component analysis, which revealed that the two Semitic groups (Gaalien and Shokrya) constituted a distinct cluster from the other Afro-Asiatic speaking groups in this study. The HLA alleles that distinguished Semitic Arabs co-exist in the same extended HLA haplotype, and those alleles are in strong linkage disequilibrium. Interestingly, we find the four-locus haplotype "C*12:02-B*52:01-DRB1*15:02-DQB1*06:01" exclusively in non-African populations and it is widely spread across Asia. The identification of this haplotype suggests a gene flow from Asia, and likely these haplotypes were brought to Africa through back migration from the Near East. These findings will be of interest to biomedical and anthropological studies that examine the demographic history of northeast Africa., (© 2021. The Author(s), under exclusive licence to European Society of Human Genetics.)
- Published
- 2021
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15. Biochemical and histopathological changes related to the topical application of Aloe vera ointment for canine pyoderma.
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Arbaga A, El-Bahrawy A, Elsify A, Khaled H, Hassan HY, and Kamr A
- Abstract
Background and Aim: Pyoderma is common in dogs, and its treatment requires a novel medication rather than antibiotic therapy. This study aimed to determine the biochemical and histopathological changes associated with the topical application of Aloe vera 20% and 40% ointments, compared with gentamicin 0.1% ointment, in dogs suffering from Staphylococcus aureus pyoderma., Materials and Methods: Serum and skin samples were collected from a negative control group before inducing pyoderma and from other subdivided groups on the 3
rd , 7th , 10th , and 14th days post-inoculation for biochemical and histopathology examination., Results: Serum aspartate aminotransferase, alanine aminotransferase (ALT), urea, and creatinine concentrations were higher in the positive control dogs on the 3rd day without treatment (DWT) compared with the negative control dogs (p<0.05). Compared with the healthy control dogs, serum zinc concentrations were lower in the positive control group on the 3rd , 7th , and 10th DWT and in dogs treated with A. vera 20% and gentamicin 0.1% ointments on the 3rd and 7th days post-treatment (p<0.05). Grossly, skin had erythema, pruritus, and pus-filled pustules of the untreated group. Microscopically, skin showed epidermal necrosis and edema, dermal collagen necrosis, and severe neutrophilic infiltration., Conclusion: Compared with A. vera 20% and gentamicin 0.1% ointments, the topical application of A. vera 40% ointment-induced quicker skin healing and decreased the inflammatory changes caused by S. aureus inoculation, based on biochemical and histopathological changes reflective of its curative efficiency. A. vera 40% ointment may be a suitable alternative to antibiotics for the treatment of staphylococcal pyoderma in dogs., (Copyright: © Arbaga, et al.)- Published
- 2021
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16. C-terminal telopeptide of type I collagen, osteocalcin, alkaline phosphatase, and parathyroid hormone in healthy and hospitalized foals.
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Kamr AM, Dembek KA, Gilsenan W, Bozorgmanesh R, Hassan HY, Rosol TJ, and Toribio RE
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- Animals, Animals, Newborn, Biomarkers blood, Female, Horses, Hospitals, Animal, Male, Sepsis blood, Sepsis veterinary, Alkaline Phosphatase blood, Collagen Type I blood, Horse Diseases blood, Osteocalcin blood, Parathyroid Hormone blood
- Abstract
Hypocalcemia is a common finding in critically ill equine patients. Parathyroid hormone (PTH) helps to maintain calcium homeostasis in hypocalcemic patients by promoting renal calcium reabsorption and bone resorption. Increased serum PTH concentrations have been reported in critically ill people and animals, including horses and foals. It is unknown whether increased secretion of PTH is associated with markers of bone turnover in hospitalized foals. The goals of this study were to measure markers of bone resorption (C-terminal telopeptide of type I collagen [CTX-I]) and bone formation (osteocalcin [OCN]; alkaline phosphatase [ALP]) and to determine their association with PTH concentrations, disease severity, and mortality in hospitalized foals. This prospective, multicenter, cross-sectional study was conducted on 75 newborn foals ≤3 d old divided into hospitalized (n = 65; 41 septic; 24 sick nonseptic) and healthy (n = 10) groups. Blood samples were collected on admission to measure serum CTX-I, OCN, and PTH concentrations and ALP activity. Data were analyzed by nonparametric methods and univariate logistic regression. Serum CTX-I and PTH concentrations were significantly higher, whereas OCN concentrations were lower, in septic compared with healthy foals (P < 0.05). Serum ALP activity was not different between groups; however, it was lower in hospitalized and septic foals with low OCN concentrations (P < 0.05). In hospitalized foals, PTH concentrations were positively correlated with CTX-I concentrations and inversely associated with ALP activity (P < 0.05). High CTX-I and low OCN concentrations were associated with disease severity (P < 0.05). Hospitalized nonsurviving foals had significantly lower OCN concentrations compared with survivors (P < 0.05), but CTX-I concentrations were not associated with survival. Hospitalized foals with PTH concentrations >12.4 pmol/L were more likely to die (OR = 1.5; 95% CI = 1.1-4.16; P < 0.05). Elevated PTH and CTX-I together with reduced OCN concentrations and ALP activity in sick foals indicates that bone resorption is increased during critical illness, which may be a compensatory mechanism to correct hypocalcemia or reflect a response to systemic inflammation and metabolic imbalances. Bone resorption could negatively impact skeletal development in the growing foal. Low OCN and high PTH concentrations were predictors of nonsurvival in hospitalized foals., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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17. Active sero-survey for European bat lyssavirus type-1 circulation in North African insectivorous bats.
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Serra-Cobo J, López-Roig M, Lavenir R, Abdelatif E, Boucekkine W, Elharrak M, Harif B, El Ayachi S, Salama AA, Nayel MA, Elsify A, El Rashedy SG, De Benedictis P, Mutinelli F, Zecchin B, Scaravelli D, Balhoul C, Zaghawa A, Hassan HY, Zaghloul AH, and Bourhy H
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- Africa epidemiology, Animals, Rhabdoviridae Infections blood, Rhabdoviridae Infections epidemiology, Serologic Tests, Chiroptera virology, Lyssavirus isolation & purification, Rhabdoviridae Infections veterinary
- Published
- 2018
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18. Synthesis, antimicrobial activity and molecular modeling study of 3-(5-amino-(2H)-1,2,4-triazol-3-yl]-naphthyridinones as potential DNA-gyrase inhibitors.
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Mohamed NG, Sheha MM, Hassan HY, Abdel-Hafez LJM, and Omar FA
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- Amination, Anti-Bacterial Agents chemical synthesis, Bacteria drug effects, Bacterial Infections drug therapy, Bacterial Infections microbiology, DNA Gyrase metabolism, Humans, Microbial Sensitivity Tests, Molecular Docking Simulation, Naphthyridines chemical synthesis, Topoisomerase II Inhibitors chemical synthesis, Triazoles chemistry, Triazoles pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Bacteria enzymology, Naphthyridines chemistry, Naphthyridines pharmacology, Topoisomerase II Inhibitors chemistry, Topoisomerase II Inhibitors pharmacology
- Abstract
Four series of triazolylnaphthyridinone derivatives were synthesized as structural surrogates of nalidixic acid. The targeted derivatives involve: 3-(5-acylamino-2H-1,2,4-triazol-3-yl)-naphtyridin-4-ones 6(a-e); 3-(5-benzylidineamino-2H-1,2,4-triazol-3-yl)-naphthyridin-4-ones 8(a-g) and their 6-bromonaphthyridin-4-one analogs 7(a-e); 9(a-g). The synthesized compounds were evaluated In vitro for their antimicrobial activity against selected resistant strains of G+ve, G-ve, and Mycobacterium phlei. The results revealed remarkable selectivity, of the tested compounds, against Bacillus subtilis and Aggregatibacter actinomycetemcomitans, which are resistant to nalidixic acid. The growth inhibition zones were ranging from 20 to 40 mm at 10 mg/ml and the respective MIC-values ∼3.68-6.3 µM. The results illustrate that the 6-bromo derivatives 7(a-e) and 9(a-g) were more potent than the non-brominated counterparts 6(a-e) and 8(a-e) respectively. Inhibition of E. coli DNA-gyrase supercoiling activity is also evaluated. The 5-(4-methoxybanzamido)-triazolyl-6-bromonaphthyridinone (7e) exhibits IC
50 = 1.94 μg/ml, which is comparable to that of nalidixic acid (IC50 : 1.74 μg/ml). In addition, the most prominent IC50 -values are displayed by: (7a;IC50 : 2.77 μg/ml); (8g; IC50 : 3.78 μg/ml); and (9d;IC50 : 3.21 μg/ml). Molecular docking to the active site of DNA-gyrase cleavage complex of Acinetobacter baumannii (PDB code: 2xkk) co-crystallized with moxifloxacin revealed similar binding modes in addition to new interactions. Assessment of drug-likeness characteristics illustrate that the synthesized compounds showed agreement to Lipinski's and Veper's parameters. The study could offer an exceptional framework that may lead to the discovery of new potent antimicrobial agents., (Copyright © 2018 Elsevier Inc. All rights reserved.)- Published
- 2018
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19. A novel mutation in the TG gene (G2322S) causing congenital hypothyroidism in a Sudanese family: a case report.
- Author
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Watanabe Y, Sharwood E, Goodwin B, Creech MK, Hassan HY, Netea MG, Jaeger M, Dumitrescu A, Refetoff S, Huynh T, and Weiss RE
- Subjects
- Australia ethnology, Congenital Hypothyroidism blood, Female, Genetic Predisposition to Disease, Humans, Infant, Newborn, Pedigree, Protein Folding, Sudan, Thyroglobulin blood, Thyroglobulin chemistry, Congenital Hypothyroidism genetics, Mutation, Missense, Thyroglobulin genetics, Exome Sequencing methods
- Abstract
Background: Congenital hypothyroidism (CH) has an incidence of approximately 1:3000, but only 15% have mutations in the thyroid hormone synthesis pathways. Genetic analysis allows for the precise diagnosis., Case Presentation: A 3-week old girl presented with a large goiter, serum TSH > 100 mIU/L (reference range: 0.7-5.9 mIU/L); free T
4 < 3.2 pmol/L (reference range: 8.7-16 pmol/L); thyroglobulin (TG) 101 μg/L. Thyroid Tc-99 m scan showed increased radiotracer uptake. One brother had CH and both affected siblings have been clinically and biochemically euthyroid on levothyroxine replacement. Another sibling had normal thyroid function. Both Sudanese parents reported non-consanguinity. Peripheral blood DNA from the proposita was subjected to whole exome sequencing (WES). WES identified a novel homozygous missense mutation of the TG gene: c.7021G > A, p.Gly2322Ser, which was subsequently confirmed by Sanger sequencing and present in one allele of both parents. DNA samples from 354 alleles in four Sudanese ethnic groups (Nilotes, Darfurians, Nuba, and Halfawien) failed to demonstrate the presence of the mutant allele. Haplotyping showed a 1.71 centiMorgans stretch of homozygosity in the TG locus suggesting that this mutation occurred identical by descent and the possibility of common ancestry of the parents. The mutation is located in the cholinesterase-like (ChEL) domain of TG., Conclusions: A novel rare missense mutation in the TG gene was identified. The ChEL domain is critical for protein folding and patients with CH due to misfolded TG may present without low serum TG despite the TG gene mutations.- Published
- 2018
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20. Northeast African genomic variation shaped by the continuity of indigenous groups and Eurasian migrations.
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Hollfelder N, Schlebusch CM, Günther T, Babiker H, Hassan HY, and Jakobsson M
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- Africa, Black People genetics, Fossils, Genome, Human, Genomics, Genotype, Haplotypes genetics, Humans, Middle East, White People genetics, DNA, Mitochondrial genetics, Genetics, Population, Human Migration, Polymorphism, Single Nucleotide genetics
- Abstract
Northeast Africa has a long history of human habitation, with fossil-finds from the earliest anatomically modern humans, and housing ancient civilizations. The region is also the gate-way out of Africa, as well as a portal for migration into Africa from Eurasia via the Middle East and the Arabian Peninsula. We investigate the population history of northeast Africa by genotyping ~3.9 million SNPs in 221 individuals from 18 populations sampled in Sudan and South Sudan and combine this data with published genome-wide data from surrounding areas. We find a strong genetic divide between the populations from the northeastern parts of the region (Nubians, central Arab populations, and the Beja) and populations towards the west and south (Nilotes, Darfur and Kordofan populations). This differentiation is mainly caused by a large Eurasian ancestry component of the northeast populations likely driven by migration of Middle Eastern groups followed by admixture that affected the local populations in a north-to-south succession of events. Genetic evidence points to an early admixture event in the Nubians, concurrent with historical contact between North Sudanese and Arab groups. We estimate the admixture in current-day Sudanese Arab populations to about 700 years ago, coinciding with the fall of Dongola in 1315/1316 AD, a wave of admixture that reached the Darfurian/Kordofanian populations some 400-200 years ago. In contrast to the northeastern populations, the current-day Nilotic populations from the south of the region display little or no admixture from Eurasian groups indicating long-term isolation and population continuity in these areas of northeast Africa.
- Published
- 2017
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- View/download PDF
21. Genetic diversity of lactase persistence in East African populations.
- Author
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Hassan HY, van Erp A, Jaeger M, Tahir H, Oosting M, Joosten LA, and Netea MG
- Subjects
- Geography, Haplotypes genetics, Heterozygote, Humans, Linguistics, Polymorphism, Single Nucleotide genetics, Sample Size, Black People genetics, Genetic Variation, Lactase genetics
- Abstract
Background: The expression of lactase which digests lactose from milk in humans is generally lost after weaning, but selected mutations influencing the promoter of the lactase gene have spread into the human populations. This is considered a classical example of gene-culture co-evolution, and several studies suggested that the lactase gene has been under strong directional evolutionary selective pressure in the past 5000 to 10,000 years., Results: In the present study we investigated the distribution of three gene variants leading to lactase persistence in 12 different East African populations as well as one European population. Our results show that with the exception of Copts and Nilotic populations who are fully lactose non-persistent, the majority of populations of East Africa show at least partly lactose persistence, with both ethnic and socio-economic aspects playing an important role in the distribution of genetic variants. In this study, the variants C/G-13907 and T/G-13915, which are the major variants among the nomadic Arabs in the Arabia and Beja of East Africa, showed remarkable frequencies in Sudanese populations, especially those of pastoralists, in line with the historical links and bidirectional migration of nomadic populations between Arabia and East Africa. The C/T-13910 variant, generally associated with European populations is uniquely present among the Fulani., Conclusions: These data indicate that a combination of socio-economic, ethnic and evolutionary factors converged to shape the genetic structure of lactase persistence in East African populations.
- Published
- 2016
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- View/download PDF
22. The genetics of East African populations: a Nilo-Saharan component in the African genetic landscape.
- Author
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Dobon B, Hassan HY, Laayouni H, Luisi P, Ricaño-Ponce I, Zhernakova A, Wijmenga C, Tahir H, Comas D, Netea MG, and Bertranpetit J
- Subjects
- Africa, Eastern, Cluster Analysis, Genetic Variation, Geography, Humans, Polymorphism, Single Nucleotide, Principal Component Analysis, Black People genetics, Genetics, Population
- Abstract
East Africa is a strategic region to study human genetic diversity due to the presence of ethnically, linguistically, and geographically diverse populations. Here, we provide new insight into the genetic history of populations living in the Sudanese region of East Africa by analysing nine ethnic groups belonging to three African linguistic families: Niger-Kordofanian, Nilo-Saharan and Afro-Asiatic. A total of 500 individuals were genotyped for 200,000 single-nucleotide polymorphisms. Principal component analysis, clustering analysis using ADMIXTURE, FST statistics, and the three-population test were used to investigate the underlying genetic structure and ancestry of the different ethno-linguistic groups. Our analyses revealed a genetic component for Sudanese Nilo-Saharan speaking groups (Darfurians and part of Nuba populations) related to Nilotes of South Sudan, but not to other Sudanese populations or other sub-Saharan populations. Populations inhabiting the North of the region showed close genetic affinities with North Africa, with a component that could be remnant of North Africans before the migrations of Arabs from Arabia. In addition, we found very low genetic distances between populations in genes important for anti-malarial and anti-bacterial host defence, suggesting similar selective pressures on these genes and stressing the importance of considering functional pathways to understand the evolutionary history of populations.
- Published
- 2015
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23. Synthesis, biological investigation and molecular docking study of N-malonyl-1,2-dihydroisoquinoline derivatives as brain specific and shelf-stable MAO inhibitors.
- Author
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Abd El-Gaber MK, Hassan HY, Mahfouz NM, Farag HH, and Bekhit AA
- Subjects
- Animals, Catalytic Domain, Cattle, Chemistry Techniques, Synthetic, Drug Stability, Female, Isoquinolines chemistry, Isoquinolines metabolism, Malonates chemistry, Malonates metabolism, Monoamine Oxidase chemistry, Monoamine Oxidase metabolism, Monoamine Oxidase Inhibitors chemistry, Monoamine Oxidase Inhibitors metabolism, Organ Specificity, Rabbits, Rats, Brain drug effects, Brain enzymology, Isoquinolines chemical synthesis, Isoquinolines pharmacology, Malonates chemical synthesis, Malonates pharmacology, Molecular Docking Simulation, Monoamine Oxidase Inhibitors chemical synthesis, Monoamine Oxidase Inhibitors pharmacology
- Abstract
A group of N-malonyl-1,2-dihydroisoquinoline derivatives were synthesized and investigated as brain specific and shelf-stable MAO inhibitors. N-malonyl-1,2-dihydroisoquinoline redox carrier system was linked through amidic bond to 4-chloro and 4-nitrobenzylidenehydrazines (9a-b), as monoamine oxidase inhibitors (MAOIs), and β-phenethylamine (14), as a model drug, to afford a novel group of N-malonyl-1,2-dihydroisoquinoline chemical delivery systems (DHIQCDSs) (13a-b and 18). These systems are expected to be stable against air oxidation due to the presence of the carbonyl group close to nitrogen of the dihydroisoquinoline. The synthesized DHIQCDS (18) was subjected to various chemical and biological investigations to evaluate its stability and prove its ability to cross the blood brain barrier and "lock-in" the brain. The in vitro chemical and enzymatic oxidation studies showed reasonable stability and adequate rate of conversion of DHIQCDS (18) to its corresponding quaternary metabolites. In vivo distribution study in rats revealed preferential concentration of the active moiety in the brain. Moreover, compounds (9a-b, 12a-b and 17) were screened for their in vitro MAO inhibitory activity compared to clorgyline as a reference compound. The inhibition profile was found to be competitive for both MAO-A and MAO-B isozymes with more selectivity toward MAO-A. Molecular docking study of compounds (9a-b, 12a-b and 17) and the suggested metabolites was carried out on both MAO-A and MAO-B isozymes. Observation of the docked poses revealed many interactions with many residues previously reported to have an effect on the inhibition of MAO enzyme., (Copyright © 2015. Published by Elsevier Masson SAS.)
- Published
- 2015
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24. Genetic variation of TLR2 and TLR4 among the Saudi Arabian population: insight into the evolutionary dynamics of the Arabian Peninsula.
- Author
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Abu-Amero KK, Jaeger M, Plantinga T, Netea MG, and Hassan HY
- Subjects
- Alleles, Biological Evolution, Gene Flow, Gene Frequency, Genetic Variation, Genotype, Haplotypes, Humans, Saudi Arabia, Asian People genetics, Polymorphism, Single Nucleotide genetics, Toll-Like Receptor 2 genetics, Toll-Like Receptor 4 genetics
- Abstract
TLR2 and TLR4 genetic variation has been investigated among the Saudis with the aim of gaining further insight into the evolutionary history of the Arabian Peninsula. Two polymorphisms located in the TLR2 gene (Pro631His and Arg753Gln, rs5743704 and rs5743708, respectively), and two (Asp299Gly and Thr399Ile, rs4986790 and rs4986791, respectively), located in the TLR4 gene have been genotyped in 201 unrelated individuals from Saudi Arabia. While the G allele has been fixed in the Arg753Gln (g.2477 G>A) polymorphism, Pro631His (g.2111 C>A) show remarkable frequencies, a polymorphism that until now has been reported exclusively among European populations. The two TLR4 markers analyzed showed moderate frequencies (ranging from 4% to 5%). Considering the reported protective role of these polymorphisms against malaria, the data suggest that the regional variation at these gene loci could have been shaped by both evolutionary infection pressure and bidirectional human migrations in the past. The population admixture may be due to the existence of gene flow from Sub-Saharan Africa and the Levant to the Arabian Peninsula.
- Published
- 2013
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25. Evaluation of in vitro and in vivo inhibitory effects of fusidic acid on Babesia and Theileria parasites.
- Author
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Salama AA, Aboulaila M, Moussa AA, Nayel MA, El-Sify A, Terkawi MA, Hassan HY, Yokoyama N, and Igarashi I
- Subjects
- Animals, Antiparasitic Agents therapeutic use, Babesiosis drug therapy, Cells, Cultured, Diminazene analogs & derivatives, Diminazene pharmacology, Diminazene therapeutic use, Drug Synergism, Female, Fusidic Acid therapeutic use, Inhibitory Concentration 50, Mice, Mice, Inbred BALB C, Theileriasis drug therapy, Time Factors, Antiparasitic Agents pharmacology, Babesia drug effects, Fusidic Acid pharmacology, Theileria drug effects
- Abstract
Fusidic acid known to has antibacterial, antifungal, and antimalarial activities. Fusidic acid blocks translation elongation factor G gene in Plasmodium falciparum. In the present study, the inhibitory effects of fusidic acid on the in vitro growth of bovine and equine Babesia parasites were evaluated. The inhibitory effect of fusidic acid on the in vivo growth of Babesia microti was also assessed. The in vitro growth of four Babesia species that were tested was significantly inhibited (P<0.05) by micromolar concentrations of fusidic acid (IC(50) values=144.8, 17.3, 33.3, and 56.25 μM for Babesia bovis, Babesia bigemina, Babesia caballi, and Theileria equi, respectively). Combinations of fusidic acid with diminazene aceturate synergistically potentiated its inhibitory effects in vitro on B. bovis and B. caballi. In B. microti-infected mice, fusidic acid caused significant (P<0.05) inhibition of the growth of B. microti at the dose of 500 mg/kg BW relative to control group. These results indicate that fusidic acid might be incorporated in treatment of babesiosis., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
26. Genetic variation and population structure of Sudanese populations as indicated by 15 Identifiler sequence-tagged repeat (STR) loci.
- Author
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Babiker HM, Schlebusch CM, Hassan HY, and Jakobsson M
- Abstract
Background: There is substantial ethnic, cultural and linguistic diversity among the people living in east Africa, Sudan and the Nile Valley. The region around the Nile Valley has a long history of succession of different groups, coupled with demographic and migration events, potentially leading to genetic structure among humans in the region., Result: We report the genotypes of the 15 Identifiler microsatellite markers for 498 individuals from 18 Sudanese populations representing different ethnic and linguistic groups. The combined power of exclusion (PE) was 0.9999981, and the combined match probability was 1 in 7.4 × 1017. The genotype data from the Sudanese populations was combined with previously published genotype data from Egypt, Somalia and the Karamoja population from Uganda. The Somali population was found to be genetically distinct from the other northeast African populations. Individuals from northern Sudan clustered together with those from Egypt, and individuals from southern Sudan clustered with those from the Karamoja population. The similarity of the Nubian and Egyptian populations suggest that migration, potentially bidirectional, occurred along the Nile river Valley, which is consistent with the historical evidence for long-term interactions between Egypt and Nubia., Conclusion: We show that despite the levels of population structure in Sudan, standard forensic summary statistics are robust tools for personal identification and parentage analysis in Sudan. Although some patterns of population structure can be revealed with 15 microsatellites, a much larger set of genetic markers is needed to detect fine-scale population structure in east Africa and the Nile Valley.
- Published
- 2011
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27. Pharmacophoric model building for antitubercular activity of the individual Schiff bases of small combinatorial library.
- Author
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Abdel-Aal WS, Hassan HY, Aboul-Fadl T, and Youssef AF
- Subjects
- Combinatorial Chemistry Techniques, Computer Simulation, Molecular Structure, Schiff Bases chemical synthesis, Schiff Bases pharmacology, Antitubercular Agents chemical synthesis, Antitubercular Agents pharmacology, Drug Design, Models, Biological, Models, Molecular, Mycobacterium tuberculosis drug effects, Schiff Bases chemistry
- Abstract
Synthesis and evaluation of anti-TB activity of individual compounds of Schiff bases combinatorial library were done against Mycobacterium tuberculosis H(37)Rv at a single concentration of 6.25mug/mL according to the protocol of TAACF. Compounds 2C and 3D produced 99% inhibitory activity on the investigated organism, while the other tested compounds showed lower activity ranging from 35 to 84%. It was found that there are no relation between the anti-TB activity of the tested compounds and their lipophilicity expressed by ClogP of these compounds. A 3D pharmacophoric model has been generated by Molecular Operating Environment (MOE) using a training set of 10 reported anti-TB compounds and testing the synthesized compounds (1A, 1B, 1D, 1E, 2C, 3A, 3C, 3D, 3E and 4A-4E). The generated pharmacophoric features include, F1: hydrogen bond donors (Don), F2: aromatic rings (Aro), F3: hydrogen bond acceptors (Acc)/metal ligator (ML), F4: Aro/hydrophobic (Hyd). In all hit set, it was found that the amidic nitrogen CONH-NC fitted the region of the Don, F1, while the amidic carbonyl group fitted the region of the Acc/ML, F3. The distances bridging F1 to F2, F3 and F4 were essential for anti-TB activity in the developed pharmacophore model, as it was confirmed from model validation procedure., (Copyright (c) 2009 Elsevier Masson SAS. All rights reserved.)
- Published
- 2010
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- View/download PDF
28. Providing an intelligible explanation to pet owners by using three-dimensional CT images: use of clinical imaging for better informed consent.
- Author
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Kishimoto M, Yamada K, Shimizu J, Lee KJ, Watarai H, Hassan HY, Iwasaki T, and Miyake Y
- Subjects
- Animals, Humans, Imaging, Three-Dimensional methods, Tomography, X-Ray Computed methods, Animals, Domestic anatomy & histology, Imaging, Three-Dimensional veterinary, Informed Consent, Patient Education as Topic methods, Tomography, X-Ray Computed veterinary
- Abstract
The purpose of the study reported here was to discuss the level of intelligibility of three-dimensional computed tomography (3D-CT) images of clinical patients for persons who are lacking veterinary knowledge. 143 undergraduate students were participated in this study. They were entirely unfamiliar with veterinary anatomy. A survey was conducted using the visual analog scale method with a focus on the level of intelligibility of the 3D-CT images compared to that of the two-dimensional CT images or radiographs. As a result, the mean value of the intelligibility of the 3D-CT image was 88.4 +/- 17.8 points out of 100 points. In clinical cases, it is very difficult for pet owners lacking veterinary knowledge to understand the clinical status of their pets even with explanations using illustrations, radiographs, and transverse CT images. It is considered that better informed consent and patient satisfaction will be obtained provided veterinarians make an effort towards intelligible patient education by using 3D-CT images.
- Published
- 2009
- Full Text
- View/download PDF
29. Fluorinated 1,2,4-Triazolo[1,5-a]pyrimidine-6-carboxylic acid derivatives as antimycobacterial agents.
- Author
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Abdel-Rahman HM, El-Koussi NA, and Hassan HY
- Subjects
- Animals, Antitubercular Agents chemistry, Antitubercular Agents pharmacology, Antitubercular Agents toxicity, Cell Survival drug effects, Chlorocebus aethiops, Fluoroquinolones chemistry, Fluoroquinolones pharmacology, Fluoroquinolones toxicity, Microbial Sensitivity Tests, Mycobacterium tuberculosis growth & development, Pyrimidines chemistry, Pyrimidines pharmacology, Pyrimidines toxicity, Structure-Activity Relationship, Triazoles chemistry, Triazoles pharmacology, Triazoles toxicity, Vero Cells, Antitubercular Agents chemical synthesis, Fluoroquinolones chemical synthesis, Mycobacterium tuberculosis drug effects, Pyrimidines chemical synthesis, Triazoles chemical synthesis
- Abstract
A series of fluorinated 1,2,4-triazolo[1,5-a]pyrimidine-6-carboxylic acid derivatives was designed and synthesized as fluoroquinolone analogues. The synthesized compounds were screened against Mycobacterium tuberculosis H(37)R(v) strain at 6.25 microg/mL concentration. Compound 4, the 7-oxo-2-(trifluoromethyl)-4,7-dihydro-1,2,4-triazolo[5,1-a]pyrimidine-6-carboxylic acid was found to be a very potent inhibitor, being able to inhibit 92% growth of M. tuberculosis H(37)R(v )at 6.25 microg/mL concentration. At the same time, it proofed to be nontoxic to mammalian cells (IC(50) > 62.5 microg/mL in VERO cells).
- Published
- 2009
- Full Text
- View/download PDF
30. Y-chromosome variation among Sudanese: restricted gene flow, concordance with language, geography, and history.
- Author
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Hassan HY, Underhill PA, Cavalli-Sforza LL, and Ibrahim ME
- Subjects
- Genetic Markers, Haplotypes, Humans, Male, Phylogeny, Population Density, Population Dynamics, Social Isolation, Sudan, Black People genetics, Chromosomes, Human, Y chemistry, Gene Flow, Genetic Variation, Geography, Language
- Abstract
We study the major levels of Y-chromosome haplogroup variation in 15 Sudanese populations by typing major Y-haplogroups in 445 unrelated males representing the three linguistic families in Sudan. Our analysis shows Sudanese populations fall into haplogroups A, B, E, F, I, J, K, and R in frequencies of 16.9, 7.9, 34.4, 3.1, 1.3, 22.5, 0.9, and 13% respectively. Haplogroups A, B, and E occur mainly in Nilo-Saharan speaking groups including Nilotics, Fur, Borgu, and Masalit; whereas haplogroups F, I, J, K, and R are more frequent among Afro-Asiatic speaking groups including Arabs, Beja, Copts, and Hausa, and Niger-Congo speakers from the Fulani ethnic group. Mantel tests reveal a strong correlation between genetic and linguistic structures (r = 0.31, P = 0.007), and a similar correlation between genetic and geographic distances (r = 0.29, P = 0.025) that appears after removing nomadic pastoralists of no known geographic locality from the analysis. The bulk of genetic diversity appears to be a consequence of recent migrations and demographic events mainly from Asia and Europe, evident in a higher migration rate for speakers of Afro-Asiatic as compared with the Nilo-Saharan family of languages, and a generally higher effective population size for the former. The data provide insights not only into the history of the Nile Valley, but also in part to the history of Africa and the area of the Sahel.
- Published
- 2008
- Full Text
- View/download PDF
31. Distinct, specific IL-17- and IL-22-producing CD4+ T cell subsets contribute to the human anti-mycobacterial immune response.
- Author
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Scriba TJ, Kalsdorf B, Abrahams DA, Isaacs F, Hofmeister J, Black G, Hassan HY, Wilkinson RJ, Walzl G, Gelderbloem SJ, Mahomed H, Hussey GD, and Hanekom WA
- Subjects
- Bronchoalveolar Lavage Fluid immunology, Female, Humans, Immunologic Memory, Interleukin-17 analysis, Interleukins analysis, Male, Th1 Cells immunology, Interleukin-22, CD4-Positive T-Lymphocytes immunology, Interleukin-17 metabolism, Interleukins metabolism, Mycobacterium tuberculosis immunology, T-Lymphocyte Subsets immunology, Tuberculosis, Pulmonary immunology
- Abstract
We investigated whether the proinflammatory T cell cytokines IL-17 and IL-22 are induced by human mycobacterial infection. Remarkably, >20% of specific cytokine-producing CD4(+) T cells in peripheral blood of healthy, mycobacteria-exposed adults expressed IL-17 or IL-22. Specific IL-17- and IL-22-producing CD4(+) T cells were distinct from each other and from Th1 cytokine-producing cells. These cells had phenotypic characteristics of long-lived central memory cells. In patients with tuberculosis disease, peripheral blood frequencies of these cells were reduced, whereas bronchoalveolar lavage fluid contained higher levels of IL-22 protein compared with healthy controls. IL-17 was not detected in this fluid, which may be due to suppression by Th1 cytokines, as PBMC IL-17 production was inhibited by IFN-gamma in vitro. However, Th1 cytokines had no effect on IL-22 production in vitro. Our results imply that the magnitude and complexity of the anti-mycobacterial immune response have historically been underestimated. IL-17- and IL-22-producing CD4(+) T cells may play important roles in the human immune response to mycobacteria.
- Published
- 2008
- Full Text
- View/download PDF
32. Co-introgression of Y-chromosome haplogroups and the sickle cell gene across Africa's Sahel.
- Author
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Bereir RE, Hassan HY, Salih NA, Underhill PA, Cavalli-Sforza LL, Hussain AA, Kwiatkowski D, and Ibrahim ME
- Subjects
- Africa, Northern, Anemia, Sickle Cell blood, Case-Control Studies, Gene Frequency, Humans, Male, Anemia, Sickle Cell genetics, Chromosomes, Human, Y genetics, Emigration and Immigration, Haplotypes genetics, Hemoglobin, Sickle genetics
- Abstract
The Sahel that extends from the Atlantic Ocean to the Ethiopian highland is a historical reservoir of Africa's cultures and grandest populations and a known arena of ancient and recent migrations. We are interested in the issue whether such migrations were also carriers of genetic traits and whether this introgression could be associated with population genetic markers. Based on analysis of Y-chromosome haplogroups, we present evidence that the sickle gene, one of the major protective polymorphisms known in malaria, has in fact found its way only recently to the gene pool of the populations in eastern Sahel. We discuss the possible dynamics of the process and give estimates of the age of the introduction of the S allele into eastern Sahel.
- Published
- 2007
- Full Text
- View/download PDF
33. Synthesis of 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid derivatives of potential anti-inflammatory activity.
- Author
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Rabea SM, El-Koussi NA, Hassan HY, and Aboul-Fadl T
- Subjects
- Animals, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents toxicity, Carrageenan, Dose-Response Relationship, Drug, Edema chemically induced, Edema prevention & control, Lethal Dose 50, Male, Rats, Rats, Wistar, Semicarbazides chemical synthesis, Semicarbazides pharmacology, Semicarbazides toxicity, Stomach Ulcer chemically induced, Stomach Ulcer pathology, Structure-Activity Relationship, Triazoles pharmacology, Triazoles toxicity, Anti-Inflammatory Agents chemical synthesis, Triazoles chemical synthesis
- Abstract
A series of 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid derivatives 4-10 were synthesized by rearrangement of 4-(3-pyridyl)-hydrazono-2-phenyl-2-oxazolin-5-one 3 in the presence of different nucleophiles to afford derivatives 4, 7, and 8, while hydroxamic acid derivative 6 was prepared from reaction of methyl ester 4 with hydroxylamine hydrochloride. Semicarbazide 9 and thiosemicarbazide 10, derivatives of the 5-phenyl-1-(3-pyridyl)-1H-1,2,4-triazole-3-carboxylic acid, were synthesized via hydrazide 8 with potassium cyanate and appropriate isothiocyanate, respectively. The structures of the synthesized compounds were confirmed by elemental analyses, IR, (1)H-NMR, and mass spectra. The results of the anti-inflammatory activity of the synthesized derivatives showed that most of the tested compounds 4-10 showed significant inhibition against carrageenan-induced rat paw edema in albino rats. Derivatives 4 and 8 showed promising results and were found to be equipotent or more potent than Indomethacin and Celecoxib as reference drugs at two dose levels, 5 and 10 mg/kg, and they have no ulcerogenic activity.
- Published
- 2006
- Full Text
- View/download PDF
34. Synthesis of di- and tripeptide analogues containing alpha-ketoamide as a new core structure for inhibition of HIV-1 protease.
- Author
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Sheha MM, Mahfouz NM, Hassan HY, Youssef AF, Mimoto T, and Kiso Y
- Subjects
- Anti-HIV Agents chemical synthesis, Anti-HIV Agents chemistry, Anti-HIV Agents pharmacology, HIV Protease Inhibitors chemistry, HIV-1 drug effects, HIV-1 enzymology, Magnetic Resonance Spectroscopy, Mass Spectrometry, Microbial Sensitivity Tests, Molecular Structure, Oligopeptides chemistry, Structure-Activity Relationship, Amides chemistry, HIV Protease Inhibitors chemical synthesis, HIV Protease Inhibitors pharmacology, Oligopeptides chemical synthesis, Oligopeptides pharmacology
- Abstract
Di- and tripeptide analogues containing alpha-ketoamide as a new core structure and incorporating allophenylnorstatine (Apns) as a transition state mimic, were designed and synthesized in the hope of obtaining a novel structural type of HIV-1 protease inhibitors. The immediate precursor, Apns-Thz-NHBu(t) was prepared by coupling of Boc-Apns with N-tert x butyl Thz-4-carboxamide hydrochloride. Removal of Boc group followed by coupling with the respective alpha-ketoacid residue (P2) gave the desired dipeptides (8-12) in almost quantitative yields. The alpha-keto tripeptides (18-21) were obtained by oxidation of the hydroxyl group of Apns (PI) in the appropriate tripeptide, iQOA-Val-Apns-(un)substituted Thz(Oxa)-NHBu(t) with DMSO/DCC. Preliminary evaluation of the activity of the synthesized derivatives was determined as percentage of enzyme inhibition at 5 microM and 50 nM levels of the di- and tripeptides respectively. The alpha-ketoamides displayed a significant enhanced potency relative to their parent isosteres as inhibitors of HIV-1 protease and are shown to be a promising new core structure for the development of enzyme inhibitors. A quantitative approach was attempted, using an LFE model, correlating the effect of structural modification and HIV-1 protease inhibition activity of the prepared dipeptides. The result indicates the contribution of the torsion angle by 84% to the activity of the inhibitors.
- Published
- 2000
- Full Text
- View/download PDF
35. Synthesis and antimicrobial activity of pyridines bearing thiazoline and thiazolidinone moieties.
- Author
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Hassan HY, el-Koussi NA, and Farghaly ZS
- Subjects
- Anti-Bacterial Agents pharmacology, Bacteria drug effects, Chemical Phenomena, Chemistry, Physical, Magnetic Resonance Spectroscopy, Microbial Sensitivity Tests, Pyridines pharmacology, Thiazoles pharmacology, Anti-Bacterial Agents chemical synthesis, Pyridines chemical synthesis, Thiazoles chemical synthesis
- Abstract
Two series of new pyridines bearing thiazoline (3a--n) and thiazolidinone (5a--e) moieties were prepared via the cyclization of the corresponding substituted pyridyl thiourea (2a--g) with an appropriately substituted phenacyl bromide or chloroacetic acid, respectively. The antimicrobial activity was determined for representative compounds and most of them showed moderate activity against Gram-positive bacteria.
- Published
- 1998
- Full Text
- View/download PDF
36. Use of 7,7,8,8-tetracyanoquinodimethane for spectrophotometric determination of certain local anaesthetics and procainamide hydrochloride.
- Author
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Mohamed AM, Hassan HY, Mohamed HA, and Hussein SA
- Subjects
- 4-Aminobenzoic Acid analysis, Anesthetics, Local chemistry, Benzocaine analysis, Hydrogen-Ion Concentration, Procainamide chemistry, Procaine analysis, Propoxycaine analysis, Spectrophotometry, Ultraviolet, Anesthetics, Local analysis, Nitriles chemistry, Procainamide analysis
- Abstract
A simple and rapid spectrophotometric procedure has been developed for the determination of four local anaesthetics containing a free primary amine moiety and of procainamide hydrochloride as the drug substances and in dosage forms. The method is based on the reaction of the drug with 7,7,8,8-tetracyanoquinodimethane in alkaline solution to produce yellow products. The chromogen was measured at 473 nm. The effects of several variables on colour development were established. Job's plots of absorbance versus molar ratio of drug to reagent indicated a 1:1 ratio for all the drugs studied. Results of the analysis of drug substances and their dosage forms by the proposed method are in good agreement with those obtained by the USP XX method.
- Published
- 1991
- Full Text
- View/download PDF
37. Spectrophotometric determination of some dibenzazepine drugs by electrophilic coupling.
- Author
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Hussein SA, El-Kommos ME, Hassan HY, and Mohamed AM
- Abstract
Two sensitive spectrophotometric methods for the determination of imipramine hydrochloride, clomipramine hydrochloride, desipramine hydrochloride, and trimipramine maleate in bulk and in dosage forms are described. The first method is based on the interaction of diazotized p-nitroaniline (DPNA) with the dibenzazepine drug in 5M hydrochloric acid. The second is based on the oxidative coupling of the dibenzazepine drug with 3-methylbenzothiazolin-2-one hydrazone (MBTH) in the presence of ammonium iron(III) sulphate in 0.1M hydrochloric acid. The resulting chromophores are measured at 575 nm (for the DPNA method) or at 620-630 nm (for the MBTH method), and are stable for at least 24 hr. The commonly encountered excipients and additives do not interfere with the determinations. Results from the analysis of pure drugs, commercial tablets and laboratory-prepared tablets by these methods agree well with those of official methods.
- Published
- 1989
- Full Text
- View/download PDF
38. Spectrophotometric determination of some dibenzazepines with picryl chloride.
- Author
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Hussein SA, Mohamed AM, and Hassan HY
- Abstract
A simple and sensitive spectrophotometric method has been developed for the determination of some dibenzazepines, based on reaction with picryl chloride in chloroform medium and measurement at 395 nm. Beer's law is obeyed in concentration ranges 0.1-1.0 microg/ml for imipramine hydrochloride, trimipramine maleate and opipramol dihydrochloride, 0.16-1.6 microg/ml for desipramine hydrochloride and 0.4-2.4 microg/ml for clomipramine hydrochloride. The method was applied successfully to the determination of dibenzazepines in tablets and the results were comparable to those obtained by official procedures.
- Published
- 1989
- Full Text
- View/download PDF
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