Gender-specific responses in gene expression of Nile tilapia (Oreochromis niloticus) to heavy metal pollution in different aquatic habitats.

Monitoring heavy metal accumulation is essential for assessing the viability of aquatic ecosystems. Our methodology involved integrating analysis of immunological, stress, inflammatory, and growth-related gene expression in male and female Nile tilapia with on-site recordings of physicochemical parameters. Additionally, we assessed the effect of different physicochemical parameters on heavy metal bioavailability and residual concentration in fish and water. Samples of fish and water were gathered from three different localities: Lake Brullus, a brackish lake sited in northern Egypt; Lake Nasser, an artificial freshwater reservoir located in southern Egypt; and El-Qanater El-Khayria, a middle-freshwater location belonging to the Rashid branch of the river Nile. The assessment of heavy metal residues (Fe, Cu, Zn, Mn, and Ni) revealed that their concentrations were higher in fish specimens compared to their counterparts in water (except for Ni). In addition, Lake Brullus emerges as the most polluted area, exhibiting elevated levels of heavy metals concentrations in water and fish specimens. In contrast, Lake Nasser showed the least degree of heavy metals pollution. Gene expression analysis revealed gender-specific responses to heavy metal exposure at the three investigated water bodies. The expression of hepatic antioxidant genes (GST and MT) and inflammatory-related genes (CC-chemokine and TNFα) increased in males compared to females. In females, the immune and pro-inflammatory-related genes (IgM and CXC2-chemokine) transcripts were upregulated. Additionally, growth-related genes were downregulated in both Lake Brullus and El-Qanater; on the contrary, fish samples from Lake Nasser exhibited a normal expression pattern of growth-related genes. Stress-related genes (HSP70 and HSP27) showed significant downregulation in gills of both genders from Lake Brullus. The minimal presence of heavy metal contaminants in Lake Nasser seems to endorse the normal patterns of gene expression across all gene categories. A potential gender-specific gene expression response towards pollution was noticed in genes associated with inflammation and antioxidant activities. This highlights the importance of considering gender-related responses in future environmental assessments.

Exposure to a Low-Oxygen Environment Causes Implantation Failure and Transcriptomic Shifts in Mouse Uteruses and Ovaries.

Hypoxia is a condition in which tissues of the body do not receive sufficient amounts of oxygen supply. Numerous studies have elucidated the intricate roles of hypoxia and its involvement in both physiological and pathological conditions. This study aimed to clarify the impact of a forced low-oxygen environment in early pregnancy by exposing mice to low-oxygen conditions for 24-72 h after fertilization. The treatment resulted in the complete failure of blastocyst implantation, accompanied by vascular hyperpermeability in the uterus. A transcriptome analysis of the uterus revealed remarkable alterations in gene expression between control normoxic- and hypoxic-treatment groups. These alterations were characterized by the differentially expressed genes categorized into the immune responses and iron coordination. Furthermore, exposure to a low-oxygen environment caused apoptosis in the corpus luteum within the ovary and a reduction in progesterone secretion. Consequently, diminished plasma progesterone levels were considered to contribute to implantation failure in combination with the activation of the hypoxic pathway in the uterus. Additionally, previous studies have demonstrated the impact of hypoxic reactions on blastocyst development and the pre-implantation process in the endometrium. Our findings suggest that the corpus luteum exhibits elevated susceptibility to hypoxia, thereby elucidating a critical aspect of its physiological response.

Camel milk or silymarin could improve the negative effects that experimentally produced by aflatoxin B1 on rat's male reproductive system.

BACKGROUND: Camel milk and silymarin have many different beneficial effects on several animal species. Meanwhile, Aflatoxins are mycotoxins with extraordinary potency that pose major health risks to several animal species. Additionally, it has been documented that aflatoxins harm the reproductive systems of a variety of domestic animals. The present design aimed to investigate the impact of aflatoxin B1 (AFB1) on rat body weight and reproductive organs and the ameliorative effects of camel milk and silymarin through measured serum testosterone, testes pathology, and gene expression of tumor necrosis factor (TNF-α), luteinizing hormone receptor (LHR), and steroidogenic acute regulatory protein (StAR) in the testes. A total of sixty mature male Wister white rats, each weighing an average of 83.67 ± 0.21 g, were used. There were six groups created from the rats. Each division had ten rats. The groups were the control (without any treatment), CM (1 ml of camel milk/kg body weight orally), S (20 mg silymarin/kg b. wt. suspension, orally), A (1.4 mg aflatoxin/kg diet), ACM (aflatoxin plus camel milk), and AS (aflatoxin plus silymarin). RESULTS: The results indicated the positive effects of camel milk and silymarin on growth, reproductive organs, and gene expression of TNF-α, LHR, and StAR with normal testicular architecture. Also, the negative effect of AFB1 on the rat's body weight and reproductive organs, as indicated by low body weight and testosterone concentration, was confirmed by the results of histopathology and gene expression. However, these negative effects were ameliorated by the ingestion of camel milk and silymarin. CONCLUSION: In conclusion, camel milk and silymarin could mitigate the negative effect of AFB1 on rat body weight and reproductive organs.

Ameliorative effects of camel milk and silymarin upon aflatoxin B1 induced hepatic injury in rats.

Aflatoxin B1 (AFB1) poses a major risk to both human and animal health because it contaminates food, feed, and grains. These dangerous effects can be mitigated using natural components. The purpose of this study was to examine the ameliorative effects of camel milk and silymarin supplementation upon aflatoxin B1 induced hepatic injury in rats. This improvement was assessed by measuring leukocytic and deferential counts, serum biochemical parameters, and gene expression of Tumor Necrosis Factor (TNF-α), antioxidant gene (NAD(P)H quinone oxidoreductase 1 (NQO1)), and base excision repair genes (APE1 and OGG1) in the liver tissue, in addition to liver histopathology. Sixty mature males Wister white rats were used to perform the present study; the rats were distributed in six groups (ten rats/group). The control group (without any treatment) received saline by gavage. The camel milk group received 1 ml of camel milk/kg body weight. The silymarin group received 1 ml of silymarin suspension solution at a dose of 20 mg of silymarin/kg of b.wt. The aflatoxin group received an aflatoxin-contaminated diet at a dose of 1.4 mg of aflatoxin /kg of diet and received saline. The camel milk + aflatoxin group received the same previous oral doses of camel milk and an aflatoxin-contaminated diet at the same time. The silymarin + aflatoxin group received the same previous doses of silymarin orally and an aflatoxin-contaminated diet at the same time. The obtained data indicated the deleterious effect of aflatoxin B1 on the leukocytic count, activity of AST and ALT, serum proteins, ferritin, alpha-fetoprotein, carcinoembryonic antigen, liver pathology, and the expression of the studied genes. However, these deleterious effects were mitigated by camel milk and silymarin supplementation. Thus, we could conclude that the ingestion of camel milk and silymarin mitigated the negative effects of AFB1 on the hematology, activity of AST and ALT, serum proteins, ferritin, alpha-fetoprotein, carcinoembryonic antigen, liver pathology, and gene expression in the rat model.

Ameliorating effect of probiotic on nonalcoholic fatty liver disease and lipolytic gene expression in rabbits.

Nonalcoholic fatty liver disease (NAFLD) is a condition that affects about 24% of people worldwide. Increased liver fat, inflammation, and, in the most severe cases, cell death are all characteristics of NAFLD. However, NAFLD pathogenesis and therapy are still not clear enough. Thus, this study aimed to determine the effect of a high-cholesterol diet (HCD) inducing NAFLD on lipolytic gene expression, liver function, lipid profile, and antioxidant enzymes in rabbits and the modulatory effects of probiotic Lactobacillus acidophilus (L. acidophilus) on it. A total of 45 male New Zealand white rabbits, eight weeks old, were randomly divided into three groups of three replicates (5 rabbits/replicate). Rabbits in group I were given a basal diet; rabbits in group II were given a high-cholesterol diet that caused NAFLD; and rabbits in group III were given a high-cholesterol diet as well as probiotics in water for 8 weeks. The results showed that a high-cholesterol diet caused hepatic vacuolation and upregulated the genes for lipoprotein lipase (LPL), hepatic lipase (HL), and cholesteryl ester transfer protein (CETP). Downregulated low-density lipoprotein receptor (LDLr) gene, increased liver enzymes [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH)], cholesterol, triglycerides (TG), low-density lipoprotein (LDL), glucose, and total bilirubin. On the other hand, it decreased high-density lipoprotein (HDL), total protein, albumin, and liver antioxidants [glutathione peroxidase (GPx), catalase (CAT), reduced glutathione (GSH), and superoxide dismutase (SOD)]. Supplementing with probiotics helped to return all parameters to normal levels. In conclusion, probiotic supplementation, especially L. acidophilus, protected against NAFLD, and restored lipolytic gene expression, liver functions, and antioxidants to normal levels.

Selenium and/or vitamin E upregulate the antioxidant gene expression and parameters in broilers.

BACKGROUND: In contrast to free radicals, the first line of protection is assumed to be vitamin E and selenium. The present protocol was designed to assess the roles of vitamin E and/or a selenium-rich diet that affected the blood iron and copper concentrations, liver tissue antioxidant and lipid peroxidation, and gene expression linked to antioxidants in the liver tissue of broilers. The young birds were classified according to the dietary supplement into four groups; control, vitamin E (100 mg Vitamin/kg diet), selenium (0.3 mg sodium selenite/kg diet), and vitamin E pulse selenium (100 mg vitamin/kg diet with 0.3 mg sodium selenite/kg diet) group. RESULTS: The results of this experiment suggested that the addition of vitamin E with selenium in the broiler diet significantly increased (P ≤ 0.05) serum iron when compared with the other groups and serum copper when compared with the vitamin E group. Moreover, the supplements (vitamin E or vitamin E with selenium) positively affected the enzymatic activity of the antioxidant-related enzymes with decreased malondialdehyde (MDA),which represents lipid peroxidation in broiler liver tissue. Moreover, the two supplements significantly upregulated genes expression related to antioxidants. CONCLUSION: Therefore, vitamin E and/or selenium can not only act as exogenous antioxidants to prevent oxidative damage by scavenging free radicals and superoxide, but also act as gene regulators, regulating the expression of endogenous antioxidant enzymes.

Intra- and inter-breed variation in immune response to acute and sub-chronic Salmonella infection and commercial immune-stimulant in two-layer breeds.

Salmonella is one of the most hazardous diseases in poultry farms. Markedly, the application of active immunostimulants is illustrated as potential protective agents against infection in poultry farms. Thus, this work aimed to explore inter- and intra-breed variation in response to acute and subchronic Salmonella enteritidis infection in two-layer breeds (one commercial [Hy-line strain] and another native [Fayoumi breed]). Besides exploring the possible protective effect of a commercial immune modulator (STIMULAN) on the two breeds during the acute infection. The ELISA antibody titer in sub-chronic infections and the expression analysis of some selected genes (IL-1ß, LITAF, TGF-ß, HSP90 and HSP70) are used as the clinical signs for acute infections to assess the possible protective role of a commercial immunomodulator (STIMULAN). Five groups were used during the acute experiment: G1-control; G2a-susceptible; G2b-resistant birds, G3-which received STIMULAN and G4-which received the infection + STIMULAN. The groups with sub-chronic infections include G1 (control), G2 (high antibody titer) and G3 (low antibody titer). The gene expressions among the susceptible birds during acute infection of both breeds are nearly similar. They only differ in the expression of HSP90 in the Fayoumi breed. However, the resistant birds vary in their gene expression profile. The effect of STIMULAN as a feed additive in non-infected birds was an up-regulation of LITAF, TGF-ß, HSP90 in Fayoumi. Moreover, a powerful stimulatory role was observed when both breeds were infected. Both breeds were asymptomatic during the sub-chronic infection. Although, the increased expression of inflammatory-related genes in the Hy-line was considered as an indication of infection persistence. Fayoumi is capable of immune clearance for this infection. Thus, the Fayoumi breed is more resistant to acute Salmonella infection. HSP90 plays a vital role in its resistance. We recommend the use of STIMULAN as an immunomodulator during Salmonella infection.

The impact of vitamin E and/or selenium dietary supplementation on growth parameters and expression levels of the growth-related genes in broilers.

BACKGROUND: Broilers are continuously stressed because of the rapid growth rate and the environmental issues associated with industrialized poultry production systems, which lead to higher susceptibility for infection with pathogens. It is well known that vitamin E (Vit. E) and selenium (Se) supplementation have protective functions in such stressful conditions. This protocol was to investigate the impact of Vit. E and/or Se on the production performance, some serum biochemistry, and expression of some growth-related gene in the liver tissue of the broilers. The day-old chicks were allotted into four groups according to the supplement; Control group and groups supplemented with Vit. E and/or Se into Vit. E group (100 mg Vit. E/kg diet), Se group (0.3 mg sodium selenite/kg diet), and Vit E + Se group that supplemented with both Vit. E and Se. RESULTS: The data of the present experiment showed that dietary inclusion of Vit. E and/or Se significantly (P ≤ 0.05) improved the production parameters without any side effect on the general health status of the broilers, which indicated by normal serum biochemical parameters. Moreover, the treatments positively affected the expression of some genes related to growth performance including growth hormone receptor (GHR) and insulin-like growth factor 1 (IGF1) in the liver tissue of broilers. CONCLUSION: Dietary supplementation of Vit. E and/or Se improved the production parameters and upregulate the growth-related genes without effect on the general health status of the broilers.

Risk factors and clinical outcomes for carbapenem-resistant Gram-negative late-onset sepsis in a neonatal intensive care unit.

BACKGROUND: Carbapenem-resistant (CR), Gram-negative (GN), late-onset sepsis (LOS) is a serious threat in the neonatal intensive care unit (NICU). AIM: To assess the prevalence of CR-GN-LOS in NICU patients and to identify the risk factors and outcomes associated with its acquisition. METHODS: Neonates with carbapenem-susceptible (CS)-GN-LOS were compared with those with CR-GN-LOS in a two-year observational study. FINDINGS: A total of 158 patients had GN-LOS; 100 infants had CS-GN-LOS and 58 infants had CR-GN-LOS. The incidence rate of CR-GN-LOS was 6.5 cases per 1000 patient-days. The most frequent bacterial strain in both groups was Klebsiella pneumoniae. The duration of total parenteral nutrition (TPN) (P=0.006) and prior carbapenem use (P=0.01) were independent risk factors for CR-GN-LOS acquisition. CR-GN-LOS was associated with higher mortality than CS-GN-LOS (P=0.04). Birth weight, small for gestational age, time to start enteral feeding, exclusive formula feeding, previous surgery, previous antifungal use, central venous device before onset, duration of central venous device, and infectious complications were identified as dependent risk factors for overall mortality. However, only male gender (P=0.04) and infectious complications (P < 0.001) were independent risk factors associated with mortality. Infectious complication rates, duration of mechanical ventilation, and length of hospital stay were significantly higher in infants with CR compared to CS-GN-LOS. CONCLUSION: The duration of TPN and carbapenem use were the independent predictors for CR-GN-LOS acquisition. CR-GN-LOS is associated with higher mortality, infectious complication rates, longer mechanical ventilation, and longer hospital stay. Male gender and infectious complications were the independent risk factors for mortality in neonates with GN-LOS.

Deeper insight into maternal genetic assessments and demographic history for Egyptian indigenous chicken populations using mtDNA analysis.

This study principally sought to reveal the demographic expansion of Egyptian indigenous chickens (EIC) using representative breeds: Sinai (North), Fayoumi (Middle) and Dandarawi (South) of Egypt as well as to deeply clarify their genetic diversity, possible matrilineal origin and dispersal routes. A total of 33 partial mitochondrial DNA sequences were generated from EIC and compared with a worldwide reference dataset of 1290 wild and domestic chicken sequences. Study populations had 12 polymorphic variable sites and 7 haplotypes. A lack of maternal substructure between EIC was detected (F ST  = 0.003). The unimodal mismatch distribution and negative values of Tajima's D (-0.659) and Fu's Fs (-0.157) indicated demographic expansion among EIC and pointed to Fayoumi as the oldest EIC population. Egyptian haplotypes were clustered phylogenetically into two divergent clades. Their phylogeography revealed an ancient single maternal lineage of Egyptian chickens likely derived from Indian-Subcontinent. Moreover, a recent maternal commercial heritage possibly originated in Yunnan-Province and/or surrounding areas was admixed restrictedly into Sinai. It is implied that Egypt was an entry point for Indian chicken into Africa and its further dispersal route to Europe. This study provides a clue supporting the previous assumption that urged utilizing consistent founder populations having closely related progenitors for synthetizing a stabilized homogenous crossbreed as a sustainable discipline in breeding program.

Factors influencing parental consent for participation in clinical research involving their children in Egypt.

Factors affecting parents' decision to involve their children in clinical research have not been studied in all cultural backgrounds. We aimed to explore the attitudes and beliefs influencing parents' decision to involve their children in clinical research in Mansoura, Egypt. Of 523 families approached, 357 filled the questionnaire. Only 98 (27.5%) parents consented to involve their child in clinical research. The children of consenters were significantly older than refusers: 8.6 (SD 7.2) versus 2.6 (SD 1.2) years. Factors favouring consent were: research of benefit to child (84.7%), enough explanation about the benefits (40.8%) and to learn more about child's condition (29.6%). Factors favouring refusal were: use of new drugs or vaccines (89.6%) and invasive procedures (84.2%). Parents' rate of consent was positively correlated with the research being non-invasive and the belief that research was of benefit to their child and negatively correlated with belief that refusal may negatively affect the care provided to their child.

Experimental and theoretical assignment of the vibrational spectra of triazoles and benzotriazoles. Identification of IR marker bands and electric response properties.

The FTIR spectra of a series of 1H- and 2H- 1,2,3- and 1,2,4- triazoles and benzotriazoles were measured in the solid state. Assignments of the observed bands were facilitated by computation of the spectra using the density functional B3LYP method with the 6-311++G** basis set. The theoretical spectra show very good agreement with experiment. Rigorous normal coordinate analyses have been performed, and detailed vibrational assignment has been made on the basis of the calculated potential energy distributions. Several ambiguities and contradictions in the previously reported vibrational assignments have been clarified. "Marker bands" characterize the triazole ring were identified. The effect of substituents, the nature of the characteristic "marker bands" and quenching of intensities of some bands are discussed. Comparison of the topology of the charge density distribution, and the electric response properties of the 1H-, and 2H- isomers of both 1,2,3- and 1,2,4 triazole have been made using the quantum theory of atoms-in-molecules (QTAIM) by calculating the Laplacian of the electron density (∇²ρ(r)). Analysis of the contour plots and relief maps of ∇²ρ(r) reveals that 1,2,3- and 1,2,4-triazoles show completely different topological features for the distribution of the electron density. Thus, while the 1,2,3-isomer is a very polar molecule, the 1,2,4-isomer is much more polarizable. Bonding characteristics show also different features. This would thus underlie the different features of their vibrational spectra. The reported vibrational assignment can be used for further spectroscopic studies of new drugs and biological compounds containing the triazole ring.

Factors influencing parental consent for participation in clinical research involving their children in Egypt

Factors affecting parents' decision to involve their children in clinical research have not been studied in all cultural backgrounds.We aimed to explore the attitudes and beliefs influencing parents' decision to involve their children in clinical research in Mansoura, Egypt.Of 523 families approached, 357 filled the questionnaire.Only 98 [27.5%]parents consented to involve their child in clinical research.The children of consenters were significantly older than refusers:8.6 [SD 7.2]versus 2.6 [SD 1.2]years.Factors favouring consent were:research of benefit to child [84.7%], enough explanation about the benefits [40.8%]and to learn more about child's condition [29.6%]. Factors favouring refusal were:use of new drugs or vaccines [89.6%]and invasive procedures [84.2%]. Parents' rate of consent was positively correlated with the research being non-invasive and the belief that research was of benefit to their child and negatively correlated with belief that refusal may negatively affect the care provided to their child

لم تخضع العوامل التي تؤثر على موافقة الوالدين على إشراك أطفالهم في البحوث السريرية، للدراسة في جميع الخلفيات الثقافية. وهدف الباحثون إلى التعرف على المواقف والمعتقدات التي تؤثر على القرارات التي يتخذها الوالدان حول مشاركة أطفالهم في البحوث السريرية في المنصورة في مصر. وقد تواصل الباحثون مع 523 أسرة، استكملت الاستبيانات منها 357 أسرة، واتضح أن 98 من الوالدين [27.5%]، فقط قد وافقوا على مشاركة أطفالهم في البحوث السريرية، وأن متوسط أعمار الأطفال الذين وافق الوالدان على مشاركتهم بالبحوث وهو 8.6 عاما [7.2 +/- ] أكبر بمقدار يعتد به إحصائيا من متوسط أعمار الأطفال الذين رفض الوالدان مشاركتهم بها وهو 2.6 عاما [1.2 +/- ]، وأن العوامل التي ترجح الموافقة هي:البحوث التي تعود بالنفع على الطفل [84.7 %]والشرح الوافي عن المنافع [40.8%]والتعلم أكثر عن حالة الطفل [29.6 %]أما العوامل التي ترجح رفض الموافقة فهي: استخدام أدوية أو لقاحات جديدة [89.6%]، والإجراءات الباضعة [84.2 %]. وكان هناك ترابطا إيجابي بين معدل موافقة الوالدين مع كون البحوث غير باضعة وكذلك مع الاعتقاد بأن البحوث نافعة لطفلها، وكان هناك ترابط سلبي مع الاعتقاد بأن رفض المشاركة قد يؤثر سلبيا على الرعاية التي تقدم لطفلها

Les facteurs influant sur la décision des parents de laisser leur enfant participer à une étude de recherche clinique n'ont pas été étudiés dans tous les contextes culturels.L'objectif de 'étude était d'examiner les attitudes et les croyances influant sur la décision des parents de laisser participer leur enfant à une étude de recherche à Mansoura [Egypte]. Sur 523 familles contactées, 357 ont rempli le questionnaire.Seuls 98 parents [27, 5 %]consentaient à laisser participer leur enfant a une recherche clinique.Les enfants des parents qui avaient donné leur consentement étaient nettement plus âgés que ceux dont les parents avaient refusé:8, 6 ans [ET 7, 2]contre 2, 6 ans [ET 1, 2]. Les facteurs favorisant le consentement étaient les suivants:une recherche bénéfique pour l'enfant [84, 7 %], des explications suffisantes sur les avantages [40, 8 %]et l'occasion de mieux connaitre l'affection de leur enfant [29, 6%]. Les facteurs favorisant le refus étaient les suivants:l'utilisation de nouveaux médicaments ou vaccins [89, 6 %]et des actes invasifs [84, 2 %]. Le taux de consentement des parents était positivement corrélé à une recherche non invasive et à la croyance que la recherche serait bénéfique pour leur enfant, et négativement corrélé à la croyance selon laquelle un refus pourrait négativement influer sur les soins fournis à leur enfant

Association between pretreatment haemoglobin levels and morphometric characteristics of the tumour, response to neoadjuvant treatment and long-term outcomes in patients with locally advanced rectal cancers.

AIM: The study was carried out to investigate whether pretreatment haemoglobin (Hb) levels act as a biomarker in the management of patients with locally advanced rectal cancer. METHOD: We prospectively collected data on all patients within our cancer network with localized low rectal cancer treated with preoperative radiotherapy/chemoradiotherapy at Mount Vernon Centre for Cancer Treatment between March 1994 and July 2008. Pretreatment Hb level was assessed as an independent variable for the whole study sample and dichotomised at a value of 12 g/dl. A multivariate analysis of covariance (MANCOVA) was conducted on parameters that had significant association on univariate analysis of covariance (ANCOVA) and correlational (Kendall tau/Pearson) analyses. Kaplan-Meier survival analysis and Cox proportional hazard models were used to determine significant prognostic markers. Statistical significance was set at 0.05. RESULTS: 463 patients (male/female 2:1; median age = 66 years, interquartile range = 56.5-73.0) were included in the analysis. There was significant tumour response of T stage (P < 0.001) and N stage (P < 0.001), with 17.6% of patients achieving a pathological complete response. Pretreatment Hb value was inversely related to the craniocaudal vertical tumour length (P = 0.02) and pretreatment T stage of the tumour (P = 0.01). Patients with Hb levels of < 12 g/dl and moderately differentiated adenocarcinoma were less responsive. Local recurrence was more common in patients with a pretreatment Hb of < 12 g/dl (hazard ratio = 1.78) over a median follow up of 24 months, but this was not statistically significant (P = 0.08). CONCLUSION: The pretreatment Hb level might be used as a biomarker of rectal tumour morphology, response to neoadjuvant chemoradiation and risk of local recurrence.

Electronic structure and decomposition reaction mechanism of cyclopropenone, phenylcylopropenone and their sulfur analogues: a theoretical study.

The electronic structure, the origin of the extraordinary stability and the reaction mechanisms of the decomposition reaction of the three-membered ring cyclopropenone (IO), its phenyl derivative (IIO) and its sulfur analogues (IS and IIS) have been investigated at the B3LYP/6-311+G** level of theory. All critical points on the reaction surface, reactants, transition states and intermediates were determined. Reaction rate constants and half-lives have been computed. Natural bond orbital (NBO) analysis has been used to investigate the type and extent of interaction in the studied species. Results indicate that the decomposition reaction occurs via a stepwise mechanism, with the formation of a short-lived intermediate. The characters of the intermediates for the decomposition of IIO and IIS are different. In case of IIO decomposition, the intermediate structure is of prevailing zwitterionic character, whereas that for the decomposition of IIS is of prevailing carbene character. Solvent effects are computed, analyzed and discussed.

Eclipsed acetaldehyde as a precursor for producing vinyl alcohol.

The MP2 and DFT/B3LYP methods at 6-311++G(d,p) and aug-cc-pdz basis sets have been used to probe the origin of relative stability preference for eclipsed acetaldehyde over its bisected counterpart. A relative energy stability range of 1.02 to 1.20 kcal/mol, in favor of the eclipsed conformer, was found and discussed. An NBO study at these chemistry levels complemented these findings and assigned the eclipsed acetaldehyde preference mainly to the vicinal antiperiplanar hyperconjugative interactions. The tautomeric interconversion between the more stable eclipsed acetaldehyde and vinyl alcohol has been achieved through a four-membered ring transition state (TS). The obtained barrier heights and relative stabilities of eclipsed acetaldehyde and the two conformers of vinyl alchol at these model chemistries have been estimated and discussed.

Toward the understanding of the metabolism of levodopa I. DFT investigation of the equilibrium geometries, acid-base properties and levodopa-water complexes.

Levodopa (LD) is used to increase dopamine level for treating Parkinson's disease. The major metabolism of LD to produce dopamine is decarboxylation. In order to understand the metabolism of LD; the electronic structure of levodopa was investigated at the Density Functional DFT/B3LYP level of theory using the 6-311+G** basis set, in the gas phase and in solution. LD is not planar, with the amino acid side chain acting as a free rotator around several single bonds. The potential energy surface is broad and flat. Full geometry optimization enabled locating and identifying the global minimum on this Potential energy surface (PES). All possible protonation/deprotonation forms of LD were examined and analyzed. Protonation/deprotonation is local in nature, i.e., is not transmitted through the molecular framework. The isogyric protonation/deprotonation reactions seem to involve two subsequent steps: First, deprotonation, then rearrangement to form H-bonded structures, which is the origin of the extra stability of the deprotonated forms. Natural bond orbital (NBO) analysis of LD and its deprotonated forms reveals detailed information of bonding characteristics and interactions across the molecular framework. The effect of deprotonation on the donor-acceptor interaction across the molecular framework and within the two subsystems has also been examined. Attempts to mimic the complex formation of LD with water have been performed.

Electronic structure of orotic acid III geometric feature and thermal properties of some transition metal orotic acid complexes.

The complexes of orotic acid with Co(II), Ni(II), Fe(III), Cu(II), and Cd(II) were prepared and their stoichiometry were determined by elemental analysis. Co(II) and Ni(II) give complexes with orotic acid of 1:1 ratio whereas that of the remaining transition metals give complexes of 1:2 ratio. The stereochemistry of the studied metal complexes has been established by analyses of their electronic spectra and magnetic susceptibilities. The mode of bonding in the studied series of metal complexes was established via, analysis of their infrared spectra. The present analysis leads to the conclusion that all metal ions studied coordinate to orotic acid via N(1) and the adjacent carboxylate group. Thermal decomposition studies of orotic acid complexes have been carried out as to understand the status of water molecules present in these complexes as well as to know their general decomposition pattern. Theoretical investigation of the electronic structure of the studied metal complexes has been carried out. MO computations at the HF-level were performed. Charge density distribution, extent of distortion from regular geometry, dipole moment, and orientation were computed and discussed.

Conventional, continuous, and telemetric monitoring of urodynamic parameters in non-human primates: a comparative study.

A comparison between three different techniques for monitoring urodynamic parameters in non-human primates was conducted in six adult female rhesus monkeys. This study was divided into two phases. In phase I, the animals were studied by conventional and continuous methods. During the study, uroflow and micturition pattern were obtained while the animals housed in a specially designed metabolic cage. Pressure transducers and EMG electrodes were surgically implanted. Then the animals were trained for 6 weeks to sit in a specially designed chair. Upon completion of the training period, continuous monitoring of the urodynamic parameters could be carried out for periods up to 14 hours. In phase II, the animals were studied with the conventional and telemetric methods. The same type of pressure transducers and EMG electrodes were implanted but they terminated in a radio transmitter powered by a long-life battery and controlled by a radio-operated switch. Conventional studies under ketamine sedation significantly increased bladder capacity, as well as the pressure at capacity (P < 0.05). Continuous monitoring was feasible, physiological, and more sensitive than the conventional techniques. Telemetric studies are superior to continuous monitoring, since the animal is not tethered to wires and provide data over a longer period of time. It is concluded that telemetric monitoring provides significantly different parameters, which could help in diagnosis and management of different voiding dysfunctions. In normal non-human primates, lower bladder capacity, higher maximum voiding pressure, higher bladder compliance, and higher incidence of detrusor instability without urethral relaxation were found. Telemetric urodynamic data on different pathological processes are currently unavailable and further work is needed in this area.

Absence status epilepticus with computed tomographic brain changes following metrizamide myelography.

Absence status epilepticus following metrizamide myelography was associated with computed tomographic scan evidence of a high concentration of the dye in brain gray matter. We suggest that absence status epilepticus is due to the direct effect of metrizamide on the cortex and that this clinically treatable condition may have escaped diagnosis in previous reports.