Carotenoids as Novel Therapeutic Molecules Against Neurodegenerative Disorders: Chemistry and Molecular Docking Analysis.

Alzheimer's disease (AD) is the most devastating neurodegenerative disorder that affects the aging population worldwide. Endogenous and exogenous factors are involved in triggering this complex and multifactorial disease, whose hallmark is Amyloid-ß (Aß), formed by cleavage of amyloid precursor protein by ß- and γ-secretase. While there is no definitive cure for AD to date, many neuroprotective natural products, such as polyphenol and carotenoid compounds, have shown promising preventive activity, as well as helping in slowing down disease progression. In this article, we focus on the chemistry as well as structure of carotenoid compounds and their neuroprotective activity against Aß aggregation using molecular docking analysis. In addition to examining the most prevalent anti-amyloidogenic carotenoid lutein, we studied cryptocapsin, astaxanthin, fucoxanthin, and the apocarotenoid bixin. Our computational structure-based drug design analysis and molecular docking simulation revealed important interactions between carotenoids and Aß via hydrogen bonding and van der Waals interactions, and shows that carotenoids are powerful anti-amyloidogenic molecules with a potential role in preventing AD, especially since most of them can cross the blood-brain barrier and are considered nutraceutical compounds. Our studies thus illuminate mechanistic insights on how carotenoids inhibit Aß aggregation. The potential role of carotenoids as novel therapeutic molecules in treating AD and other neurodegenerative disorders are discussed.

Anti-amyloid aggregation activity of novel carotenoids: implications for Alzheimer's drug discovery.

Alzheimer's disease (AD) is the leading cause of dementia, affecting approximately 33.5 million people worldwide. Aging is the main risk factor associated with AD. Drug discovery based on nutraceutical molecules for prevention and treatment of AD is a growing topic. In this sense, carotenoids are phytochemicals present mainly in fruits and vegetables with reported benefits for human health. In this research, the anti-amyloidogenic activity of three carotenoids, cryptocapsin, cryptocapsin-5,6-epoxide, and zeaxanthin, was assessed. Cryptocapsin showed the highest bioactivity, while cryptocapsin-5,6-epoxide and zeaxanthin exhibited similar activity on anti-aggregation assays. Molecular modeling analysis revealed that the evaluated carotenoids might follow two mechanisms for inhibiting Aß aggregation: by preventing the formation of the fibril and through disruption of the Aß aggregates. Our studies provided evidence that cryptocapsin, cryptocapsin-5,6-epoxide, and zeaxanthin have anti-amyloidogenic potential and could be used for prevention and treatment of AD.

CoagVDb: a comprehensive database for coagulation factors and their associated SAPs.

The current state of the art in medical genetics is to identify and classify the functional (deleterious) or non-functional (neutral) single amino acid substitutions (SAPs), also known as non-synonymous SNPs (nsSNPs). The primary goal is to elucidate the mechanisms through which functional SAPs exert their effects, and ultimately interrogating this information for association with complex phenotypes. This work focuses on coagulation factors involved in the coagulation cascade pathway which plays a vital role in the maintenance of homeostasis in the human system. We developed an integrated coagulation variation database, CoagVDb, which makes use of the biological information from various public databases such as NCBI, OMIM, UniProt, PDB and SAPs (rsIDs/variant). CoagVDb enriched with computational prediction scores classify SAPs as either deleterious or tolerated. Also, various other properties are incorporated such as amino acid composition, secondary structure elements, solvent accessibility, ordered/disordered regions, conservation, and the presence of disulfide bonds. This specialized database provides integration of various prediction scores from different computational methods along with gene, protein, and disease information. We hope our database will act as a useful reference resource for hematologists to reveal protein structure-function relationship and disease genotype-phenotype correlation.

CoagVDb: a comprehensive database for coagulation factors and their associated SAPs

The current state of the art in medical genetics is to identify and classify the functional (deleterious) or non-functional (neutral) single amino acid substitutions (SAPs), also known as non-synonymous SNPs (nsSNPs). The primary goal is to elucidate the mechanisms through which functional SAPs exert their effects, and ultimately interrogating this information for association with complex phenotypes. This work focuses on coagulation factors involved in the coagulation cascade pathway which plays a vital role in the maintenance of homeostasis in the human system. We developed an integrated coagulation variation database, CoagVDb, which makes use of the biological information from various public databases such as NCBI, OMIM, UniProt, PDB and SAPs (rsIDs/variant). CoagVDb enriched with computational prediction scores classify SAPs as either deleterious or tolerated. Also, various other properties are incorporated such as amino acid composition, secondary structure elements, solvent accessibility, ordered/disordered regions, conservation, and the presence of disulfide bonds. This specialized database provides integration of various prediction scores from different computational methods along with gene, protein, and disease information. We hope our database will act as a useful reference resource for hematologists to reveal protein structure-function relationship and disease genotype-phenotype correlation.

Considerations for screening live kidney donors for endemic infections: a viewpoint on the UNOS policy.

In February 2013, the Organ Procurement and Transplantation Network mandated that transplant centers perform screening of living kidney donors prior to transplantation for Strongyloides, Trypanosoma cruzi and West Nile virus (WNV) infection if the donor is from an endemic area. However, specific guidelines for screening were not provided, such as the optimal testing modalities, timing of screening prior to donation and the appropriate selection of donors. In this regard, the American Society of Transplantation Infectious Diseases Community of Practice, together with disease-specific experts, has developed this viewpoint document to provide guidance for the testing of live donors for Strongyloides, T. cruzi and WNV infection, specifically identifying at-risk populations and testing algorithms, including advantages, limitations and interpretation of results.

Characterization and cross-species amplification of microsatellite markers in African Silverbill (Lonchura cantans).

We tested the cross-amplification of eight microsatellites developed for Bengalese finch in African Silverbill (Lonchura cantans). In order to develop resources for conservation genetic studies in the species L. cantans, we tested the amplification success and polymorphism in eight previously developed microsatellite loci, in L. cantans. All eight microsatellite markers were successfully amplified, of which all were polymorphic, with 3 to 9 alleles and an expected heterozygosity (HE) ranging from 0.606 to 0.718. On average, there were 5.25 alleles/locus and a mean HE of 0.6456. These eight polymorphic markers could be of potential use in studies of genetic variability, population structure, and reproductive strategy of African Silverbills. The markers tested should be useful for population and conservation genetic studies in this genus, and, in particular, for species closely related to the source species, L. cantans.

Effect of post-thaw incubation on semen characteristics of ram spermatozoa cryopreserved under controlled and uncontrolled rate of cooling

Exposure of frozen-thawed spermatozoa to a thermal resistance test reveals damages which are not apparent immediately after thawing but are useful to assess the fertilizing ability of ram spermatozoa. Our earlier study has shown that cryopreservation of ram spermatozoa under controlled rate of cooling piror yo controlled rate of freezing. Egg yolk-Test-glycerol extender and packaged in 0.25 ml straws. Straws representing Group 1 were cooled in a programmable cell freezer from 25 to 5°C at the rate of 0.15°C per minute followed by a holding time of 2 h forequilibration, while straws of Group 2 were allowed to cool slowly up to 5°C and equilibrate for 2 h in the cold cabinet. After equilibration, straws of Group 2 were also loaded in the cell freezer for freezing straws of both the treatment groups simultaneously from 5 to –125°C at the rate of 25°C per minute. Thawing of straws was done at 50°C for 10 seconds and thawed spermatozoa were subjected to a thermal resistance test at 37°C for4 h. Samples were assessed immediately after thawing and at hourly interval for sperm motion characteristics by computer-aided semen analysis technique. Post-thaw incubated spermatozoa were also evaluated at 0, 1, 2, 3, and 4 h for acrosomal integrity after staining the dried semen smears with Giemsa stain. The % motility, % rapid moving spermatozoa, % linearity and % sperm with normal acrosome were significantly (P < 0.05) higher in Group 1 compared to Group 2. The effect of incubation time was also significant (P < 0.05) on % motility, fraction of rapid motile spermatozoa, % linearity, curvilinear velocity, average path velocity, straight line velocity, area of sperm head, lateral head displacement and % spermatozoa with normal acrosome. The % motility, % rapid motile spermatozoa, sperm velocity, lateral head displacement and % spermatozoa with normal acrosomeprogressively declined during 4 h of incubation but the decline in all the traits was less in Group 1 compared to Group 2. The results showed that controlled rate of cooling conferred better cryopreserving ability to ram spermatozoa for post-thaw thermoresistance test compared to uncontrolled rate of cooling prior to programmable freezing.(AU)

Effect of post-thaw incubation on semen characteristics of ram spermatozoa cryopreserved under controlled and uncontrolled rate of cooling

Exposure of frozen-thawed spermatozoa to a thermal resistance test reveals damages which are not apparent immediately after thawing but are useful to assess the fertilizing ability of ram spermatozoa. Our earlier study has shown that cryopreservation of ram spermatozoa under controlled rate of cooling piror yo controlled rate of freezing. Egg yolk-Test-glycerol extender and packaged in 0.25 ml straws. Straws representing Group 1 were cooled in a programmable cell freezer from 25 to 5°C at the rate of 0.15°C per minute followed by a holding time of 2 h forequilibration, while straws of Group 2 were allowed to cool slowly up to 5°C and equilibrate for 2 h in the cold cabinet. After equilibration, straws of Group 2 were also loaded in the cell freezer for freezing straws of both the treatment groups simultaneously from 5 to –125°C at the rate of 25°C per minute. Thawing of straws was done at 50°C for 10 seconds and thawed spermatozoa were subjected to a thermal resistance test at 37°C for4 h. Samples were assessed immediately after thawing and at hourly interval for sperm motion characteristics by computer-aided semen analysis technique. Post-thaw incubated spermatozoa were also evaluated at 0, 1, 2, 3, and 4 h for acrosomal integrity after staining the dried semen smears with Giemsa stain. The % motility, % rapid moving spermatozoa, % linearity and % sperm with normal acrosome were significantly (P < 0.05) higher in Group 1 compared to Group 2. The effect of incubation time was also significant (P < 0.05) on % motility, fraction of rapid motile spermatozoa, % linearity, curvilinear velocity, average path velocity, straight line velocity, area of sperm head, lateral head displacement and % spermatozoa with normal acrosome. The % motility, % rapid motile spermatozoa, sperm velocity, lateral head displacement and % spermatozoa with normal acrosomeprogressively declined during 4 h of incubation but the decline in all the traits was less in Group 1 compared to Group 2. The results showed that controlled rate of cooling conferred better cryopreserving ability to ram spermatozoa for post-thaw thermoresistance test compared to uncontrolled rate of cooling prior to programmable freezing.

One-hour meal tolerance test to assess withdrawal of insulin therapy in overweight patients with type 2 diabetes.

OBJECTIVE: To evaluate the clinical usefulness of a 1-hour meal tolerance test to determine the feasibility and safety of discontinuation of insulin therapy in overweight, insulin-treated patients with type 2 diabetes mellitus. METHODS: Overweight patients who presented with metabolic decompensation at initial diagnosis of type 2 diabetes were hospitalized and treated with insulin. A 1-hour meal tolerance test was performed in an outpatient setting when patients had maintained a stable metabolic status with decreasing daily insulin requirement and the possibility of withdrawal of insulin therapy was considered. After an overnight fast, venous blood samples were collected before and 1 hour after consumption of an oral liquid meal (240 mL, 240 kcal, approximately 30 g of sucrose) to measure glucose and C-peptide levels. If the postmeal glucose level was < or = 10 mmol/L, the insulin therapy was discontinued. Patients underwent follow-up to validate the clinical decision. RESULTS: Twenty-four overweight adult Mexican American patients (8 of whom had ketoacidosis) were treated with insulin at initial diagnosis of type 2 diabetes. The mean insulin dosages were reduced progressively from 71 +/- 8 U/day to 31 +/- 3 U/day during a period of 4 +/- 0.5 months. At that stage, the mean fasting and 1-hour postmeal blood glucose levels were 5.0 +/- 0.2 mmol/L and 8.4 +/- 0.4 mmol/L, respectively. Meal-induced plasma C-peptide levels showed 1.9- to 4-fold increases, confirming substantial endogenous insulin secretion. The C-peptide responses were similar in the two subgroups of patients with or without initial ketoacidosis. On the basis of postmeal blood glucose levels, the insulin therapy was discontinued in all cases. After 3 months of follow-up, all patients were in good metabolic control. Fourteen patients underwent follow-up for >12 months; 10 of them were maintained without antidiabetic medications for 21.4 +/- 2.8 months. Two patients were treated with sulfonylurea drugs after 4 months, and another two required insulin therapy by the 4th and 18th months, respectively. CONCLUSION: A 1-hour postmeal blood glucose level is helpful for deciding the withdrawal of insulin therapy in overweight, insulin-treated patients with type 2 diabetes.

Myocardial oxidative stress and antioxidants in hypertension as a result of nitric oxide synthase inhibition.

Rats were made hypertensive by the administration of the nitric oxide synthase inhibitor nitro-L-arginine (LNA, 2.74 mmol/L) in drinking water for 7 d. Hearts from hemodynamically assessed animals were analyzed for lipid peroxidation (LPO), gamma-glutamylcysteine-synthetase (gamma-GCS), glutathione disulfide reductase (GR), glutathione peroxidase (GSHPx), catalase (CAT), superoxide dismutase (SOD), and total radical trapping potential (TRAP) activities. LNA treatment increased the mean arterial blood pressure by 46% and the heart rate by 22% without changing plasma renin activity. LNA treatment resulted in a 30% increase in LPO. gamma-GCS was reduced by 48% and GR by 36% in the cardiac tissue of hypertensive rats as compared to controls. The activity of nonselenium GSHPx was reduced by 27%, and selenium-dependent GSHPx activity in the heart was not affected by LNA treatment. In hypertensive rats, SOD activity was increased by 16%, and CAT was decreased by 46%. TRAP was lower (27%) in the myocardium of hypertensive rats than in that of controls. These data suggest that LNA-induced hypertension is associated with increased myocardial oxidative stress.

Tuberculosis in England and Wales in 1993: results of a national survey. Public Health Laboratory Service/British Thoracic Society/Department of Health Collaborative Group.

BACKGROUND: A national survey of tuberculosis notifications in England and Wales was carried out in 1993 to determine the notification rate of tuberculosis and the trends in the occurrence of disease by ethnic group in comparison with the findings of similar surveys in 1978/79, 1983, and 1988. The prevalence of HIV infection in adults notified with tuberculosis in the survey period was also estimated. METHODS: Clinical, bacteriological, and sociodemographic information was obtained on all newly notified cases of tuberculosis in England and Wales during the six months from 2 January to 2 July 1993. The prevalence of HIV infection in 16-54 year old patients with tuberculosis notified throughout 1993 was assessed using "unlinked anonymous" testing supplemented by matching of the register of patients with tuberculosis with that of patients with AIDS reported to the PHLS AIDS centre. Annual notification rates were calculated using population estimates from the 1993 Labour Force Survey. RESULTS: A total of 2706 newly notified patients was eligible for inclusion in the survey of whom 2458 were previously untreated the comparable figures for 1988 were 2408 and 2163. The number of patients of white ethnic origin decreased from 1142 (53%) in 1988 to 1088 (44%) in 1993 whereas those of patients of Indian, Pakistani, or Bangladeshi (Indian subcontinent (ISC)) ethnic origin increased from 843 (39%) in 1988 to 1014 (41%) and those of "other" (non-white, non-ISC) ethnic origins increased from 178 (8%) to 356 (14%). The largest increase was seen in the black African ethnic group from 37 in 1988 to 171 in 1993. Forty nine per cent of patients had been born abroad and the highest rates were seen in those who had recently arrived in this country. The overall annual notification rate for previously untreated tuberculosis in England and Wales increased between 1988 and 1993 from 8.4 to 9.2 per 100,000 population. The rate declined in the white, Indian, and black Caribbean ethnic groups and increased in all other groups. In the white group the rate of decline has slowed since the last survey: in several age groups the rates were higher in 1993 than 1988 but the numbers in these groups were small. Thirty six (4.1%) of the 882 previously untreated respiratory cases were resistant to isoniazid and three (0.3%) to isoniazid and rifampicin. Sixty two (2.3%) adults aged 16-54 years were estimated to be HIV-infected. Evidence of under-reporting of HIV positive tuberculosis patients was found. CONCLUSIONS: The number of cases and annual notification rate for previously untreated tuberculosis increased between 1988 and 1993. Although the decline in rates in the white population has continued, the rate of decline has slowed. The high rates in the ISC ethnic group population have continued to decline since 1988 whereas rates in the black African group have increased. An increased proportion of cases were found among people born abroad, particularly those recently arrived in this country. In previously untreated cases the level of drug resistance remains low and multi-drug resistance is rare. A small proportion of adults with tuberculosis were infected with HIV but there may be selective undernotification of tuberculosis in these patients.

Histocompatability antigens and immunoglobulin G insulin antibodies in Mexican-American insulin-dependent diabetic patients.

To determine the association of histocompatability antigens (HLA) with insulin-dependent diabetes (IDD) in Mexican-Americans, we determined HLA-A, -B, and -C specificities in 112 unrelated patients and 332 controls, and HLA-DR specificities in 85 patients and 209 controls. We also studied immunoglobulin G (IgG) insulin antibody formation in 56 Mexican-Americans with IDD, and the relationship between antibody formation and HLA-DR antigens. IDD patients have a significant increase in HLA-DR4 compared to the control population (chi 2 = 14.75; corrected P less than 0.0001). HLA-DR2 was not detected in any patient with IDD. A significant association between HLA-Aw30 and HLA-B18 was found in IDD patients (chi 2 = 9.39; P less than 0.05) as compared to controls. IgG insulin antibody formation was significantly increased in HLA-DR3- and -DR4-negative patients compared to that in patients positive for both antigens (P less than 0.05). These findings support previous observations in caucasians and black Americans indicating that HLA-DR specificities are associated with IDD and may play a role in determining its mode of inheritance, and perhaps its pathogenesis, independent of ethnic differences. HLA-DR immune-associated antigens are also of importance in determining IgG insulin antibody formation.

HLA-DRw antigens in Mexican-American and Black-American diabetic patients.

HLA-A, - B, and -C antigens were studied in 67 Mexican-American and 38 black-American diabetic patients who had the onset of their disease before age 31 yr. Control populations consisted of 322 Mexican-American and 367 black-American subjects for HLA-A, -B, and -C antigens. In addition, HLA-DRw antigens were studied in 60 Mexican-American and 34 black-American diabetic patients. Control populations for HLA-DRw antigens consisted of 189 Mexican-American and 145 black-American subjects. We found that juvenile-onset--diabetic patients of Mexican-American origin who had the onset of their disease before age 19 demonstrated a significant increase in HLA-DRw4. HLA-DRw4 was also significantly increased in black-American patients with juvenile-onset diabetes mellitus. HLA-DRw2 was not detected in any patient with juvenile-onset diabetes in either ethnic group. A significant association was found between HLA-B18 and HLA-DRw3 in Mexican-American juvenile-diabetic patients. These findings, which are comparable to those in similar Caucasian patients, provide additional information to support the hypothesis that HLA-DRw antigens play a major role in determining the susceptibility to juvenile-onset diabetes mellitus.