Transcriptomic Analysis of Alzheimer's Disease Pathways in a Pakistani Population.

Background: Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder that is most prevalent in elderly individuals, especially in developed countries, and its prevalence is now increasing in developing countries like Pakistan.

Objective: Our goal was to characterize key genes and their levels of expression and related molecular transcriptome networks associated with AD pathogenesis in a pilot case-control study in a Pakistani population.

Methods: To obtain the spectrum of molecular networks associated with pathogenesis in AD patients in Pakistan (comparing cases and controls), we used high-throughput qRT-PCR (TaqMan Low-Density Array;  = 33 subjects) coupled with Affymetrix Arrays ( = 8) and Ingenuity Pathway Analysis (IPA) to identify signature genes associated with Amyloid processing and disease pathways.

Transcriptomics of MASLD Pathobiology in African American Patients in the Washington DC Area .

Metabolic-dysfunction-associated steatotic liver disease (MASLD) is becoming the most common chronic liver disease worldwide and is of concern among African Americans (AA) in the United States. This pilot study evaluated the differential gene expressions and identified the signature genes in the disease pathways of AA individuals with MASLD. Blood samples were obtained from MASLD patients ( = 23) and non-MASLD controls ( = 24) along with their sociodemographic and medical details.

Insights on the pathogenesis of type 2 diabetes as revealed by signature genomic classifiers in an African American population in the Washington, DC area.

Aims: African Americans (AA) in the United States have a high risk of type 2 diabetes mellitus (T2DM) and suffer from disparities in the prevalence, mortality, and comorbidities of the disease compared to other Americans. The present study aimed to shed light on the molecular mechanisms of disease pathogenesis of T2DM among AA in the Washington, DC region.

Methods: We performed TaqMan Low Density Arrays (TLDA) on 24 genes of interest that belong to three categories: metabolic disease and disorders, cancer-related genes, and neurobehavioural disorders genes.

Correlates and Covariates of Type 2 Diabetes in an African American Population in the Washington DC Area.

In the United States, type 2 diabetes mellitus (T2DM) disproportionately affects the African American (AA) community, which has not been systematically included in molecular studies of underlying mechanisms. As part of a gene expression study, we recruited cases with T2DM and matched, unaffected controls at an urban hospital in Washington, DC, with a majority AA population. Here we describe the profile of socio-demographic, behavioral, and health-related associations of the study population.

Peroxisome Proliferator-Activated Receptor-α () Expression in a Clinical Population of Pakistani Patients with Type 2 Diabetes and Dyslipidemia.

Poor glycemic control and dyslipidemia are hallmarks of type 2 diabetes mellitus (T2DM), which predispose to cardiovascular diseases. Peroxisome proliferator-activated receptor-α () has been associated with atherosclerosis, but its role in T2DM is less clear. Previously, we studied PPARα expression levels in diabetics with and without dyslipidemia (DD).

Reshaping an Acyclic Nucleoside Phosphonate into a Selective Anti-hepatitis B Virus Compound.

Minor structural modifications of acyclic nucleoside phosphonates can dramatically affect their antiviral properties. This work discloses a shift in the selectivity spectrum of 3-hydroxy-2-(phosphonomethoxy)propyl (HPMP) nucleotides from herpesviruses toward hepatitis B virus (HBV) induced by their acyclic chain 2-substitution with a nonpolar group. Two series of racemic (,)-2-methyl-3-hydroxy-2-(phosphonomethoxy)propyl (MHPMP) and (,)-2-ethynyl-3-hydroxy-2-(phosphonomethoxy)propyl (EHPMP) nucleotides were initially synthesized.

Small Animal Models for Human Immunodeficiency Virus (HIV), Hepatitis B, and Tuberculosis: Proceedings of an NIAID Workshop.

The main advantage of animal models of infectious diseases over in vitro studies is the gain in the understanding of the complex dynamics between the immune system and the pathogen. While small animal models have practical advantages over large animal models, it is crucial to be aware of their limitations. Although the small animal model at least needs to be susceptible to the pathogen under study to obtain meaningful data, key elements of pathogenesis should also be reflected when compared to humans.

Synthesis and antiviral evaluation of base-modified deoxythreosyl nucleoside phosphonates.

l-α-2'-Deoxythreosyl nucleoside phosphonates and their phosphonodiamidate prodrugs with a hypoxanthine, 2,6-diaminopurine, 2-amino-6-cyclopropylaminopurine, 7-deazaadenine, 5-fluorouracil and 5-methylcytosine heterocycle as a nucleobase were synthesized and evaluated for their inhibitory activity against HIV and HBV. The 2,6-diaminopurine modified analogue 23a displayed the most potent activity against HIV, with an EC value of 11.17 μM against HIV-1 (III) and an EC value of 8.

SB 9200, a novel agonist of innate immunity, shows potent antiviral activity against resistant HCV variants.

SB 9200 is a novel, first-in-class oral modulator of innate immunity that is believed to act via the activation of the RIG-I and NOD2 pathways. SB 9200 has broad-spectrum antiviral activity against RNA viruses including hepatitis C virus (HCV), norovirus, respiratory syncytial virus, and influenza and has demonstrated activity against hepatitis B virus (HBV) in vitro and in vivo. In phase I clinical trials in chronically infected HCV patients, SB 9200 has been shown to reduce HCV RNA by up to 1.

Regulation of human norovirus VPg nucleotidylylation by ProPol and nucleoside triphosphate binding by its amino terminal sequence in vitro.

The VPg protein of human Norovirus (hNoV) is a multi-functional protein essential for virus replication. The un-cleaved viral precursor protein, ProPol (NS5-6) was 100-fold more efficient in catalyzing VPg nucleotidylylation than the mature polymerase (Pol, NS6), suggesting a specific intracellular role for ProPol. Sequential and single-point alanine substitutions revealed that several positively charged amino acids in the N-terminal region of VPg regulate its nucleotidylylation by ProPol.

Viral transmission risk factors in an Egyptian population with high hepatitis C prevalence.

Background: Egypt has the world's highest prevalence of infection with hepatitis C virus (HCV), which is a major cause of hepatocellular carcinoma. The high HCV prevalence is largely attributed to the parenteral antischistosomal therapy (PAT) campaigns conducted from the 1950s through the 1980s; however, the primary modes of transmission in the post-PAT period are not well known. In this study we examined the associations between HCV prevalence and exposures to risk factors, including PAT, in a high HCV prevalence population.

Hepatitis C virus Genotype 1a core gene nucleotide patterns associated with hepatocellular carcinoma risk.

Specific sequence changes in codons 70 and 91 of the hepatitis C virus genotype 1b (HCV GT1b) core gene have been associated with increased risk of hepatocellular carcinoma (HCC). Essentially all previous studies were conducted in Asian populations with a wide range of liver disease, and none were conducted specifically in GT1a-infected individuals. We conducted a pilot study in a multiethnic population in the USA with HCV-related cirrhosis to determine if this association extended to GT1a-infected individuals and to determine if other sequence changes in the HCV core gene were associated with HCC risk.

Conservation of antiviral activity and improved selectivity in PMEO-DAPym upon pyrimidine to triazine scaffold hopping.

Acyclic nucleoside phosphonates incorporating 2,4-diaminotriazine (DAT) as a 5-aza-analog of the 2,4-diamino-pyrimidine (DAPym) nucleobase present in PMEO-DAPyms have been synthesized. The lead PMEO-DAT is as inhibitory against HIV, HBV, MSV and VZV replication as the parent PMEO-DAPym and equally inefficient at markedly affecting replication of HSV-1, HSV-2 and HCMV. A rationale for this similar biological profile is proposed on the basis of structural differences in the active site of the viral DNA polymerases.

The p4-p2' amino acids surrounding human norovirus polyprotein cleavage sites define the core sequence regulating self-processing order.

Unlabelled: Noroviruses (NoV) are members of the family Caliciviridae. The human NoV open reading frame 1 (ORF1) encodes a 200-kDa polyprotein which is cleaved by the viral 20-kDa 3C-like protease (Pro, NS6) into 6 nonstructural proteins that are necessary for viral replication. The NoV ORF1 polyprotein is processed in a specific order, with "early" sites (NS1/2-3 and NS3-4) being cleaved rapidly and three "late" sites (NS4-5, NS5-6, and NS6-7) processed subsequently and less efficiently.

Treatment of norovirus infections: moving antivirals from the bench to the bedside.

Noroviruses (NV) are the most common cause of acute gastrointestinal illness in the United States and worldwide. The development of specific antiviral countermeasures has lagged behind that of other viral pathogens, primarily because norovirus disease has been perceived as brief and self-limiting and robust assays suitable for drug discovery have been lacking. The increasing recognition that NV illness can be life-threatening, especially in immunocompromised patients who often require prolonged hospitalization and intensive supportive care, has stimulated new research to develop an effective antiviral therapy.

Enzyme kinetics of the human norovirus protease control virus polyprotein processing order.

The human norovirus (NoV) polyprotein is cleaved into mature non-structural proteins by both mature NoV protease (Pro, NS6) and its un-cleaved precursor (ProPol, NS6-7). Processing order is well-established with 'early' and 'late' cleavages, but the governing enzymatic mechanisms are unknown. Enzyme kinetics of a GII Pro and ProPol were analyzed using synthetic peptides representing the five natural polyprotein cleavage sites.

RNA binding by human Norovirus 3C-like proteases inhibits protease activity.

A highly active, fluorescence-based, in vitro assay for human Norovirus protease from genogroup I and II viruses was optimized utilizing as little as 0.25μM enzyme, pH 7.6, and substrate:enzyme of 50-100.

2'-Fluoro-6'-methylene-carbocyclic adenosine phosphoramidate (FMCAP) prodrug: in vitro anti-HBV activity against the lamivudine-entecavir resistant triple mutant and its mechanism of action.

Novel 2'-fluoro-6'-methylene-carbocyclic adenosine (FMCA) monophosphate prodrug (FMCAP) was synthesized and evaluated for its in vitro anti-HBV potency against a lamivudine-entecavir resistant clone (L180M+M204V+S202G). FMCA demonstrated significant antiviral activity against wild-type as well as lamivudine-entecavir resistant triple mutant (L180M+M204V+S202G). The monophosphate prodrug (FMCAP) demonstrated greater than 12-fold (12×) increase in anti-HBV activity without increased cellular toxicity.

Thiazolides as novel antiviral agents. 2. Inhibition of hepatitis C virus replication.

We report the activities of a number of thiazolides [2-hydroxyaroyl-N-(thiazol-2-yl)amides] against hepatitis C virus (HCV) genotypes IA and IB, using replicon assays. The structure-activity relationships (SARs) of thiazolides against HCV are less predictable than against hepatitis B virus (HBV), though an electron-withdrawing group at C(5') generally correlates with potency. Among the related salicyloylanilides, the m-fluorophenyl analogue was most promising; niclosamide and close analogues suffered from very low solubility and bioavailability.

Antiviral activity of novel 2'-fluoro-6'-methylene-carbocyclic adenosine against wild-type and drug-resistant hepatitis B virus mutants.

Novel 2'-fluoro-6'-methylene-carbocyclic adenosine (9) was synthesized and evaluated its anti-HBV activity. The titled compound demonstrated significant antiviral activity against wild-type as well as lamivudine, adefovir and double lamivudine/entecavir resistant mutants. Molecular modeling study indicate that the 2'-fluoro moiety by a hydrogen bond, as well as the van der Waals interaction of the carbocyclic ring with the phenylalanine moiety of the polymerase promote the positive binding, even in the drug resistant mutants.

Mutations in HCV non-structural genes do not contribute to resistance to nitazoxanide in replicon-containing cells.

Nitazoxanide (NTZ) exhibits potent antiviral activity against hepatitis C virus (HCV) in cell culture. Previously, HCV replicon-containing cell lines resistant to NTZ were selected, but transfer the HCV NTZ-resistance phenotype was not observed following transfection of whole cell RNA. To further explore the nature of the resistance of HCV to NTZ, full length HCV replicon sequences were obtained from two NTZ-resistant (NTZ-11, TIZ-9), and the parental (RP7) cell lines.

Synthesis and antiviral activity of cyclopropyl-spirocarbocyclic adenosine, (4R,5S,6R,7R)-4-(6-amino-9H-purin-9-yl)-7-(hydroxymethyl)spiro[2.4]heptane-5,6-diol against hepatitis C virus.

An efficient method was developed for the synthesis of 6-exocyclic methylene carbocyclic intermediate 4. The Simmons-Smith cyclopropanation protocol was applied on the 6-exocyclic methylene of intermediate 4 and demonstrated its utility for the synthesis of novel class of a spiro-carbocyclic nucleoside analog 8. The titled compound 8 demonstrated a significant antiviral activity against HCV with EC(50) values of 0.

Thiazolides as novel antiviral agents. 1. Inhibition of hepatitis B virus replication.

We report the syntheses and activities of a wide range of thiazolides [viz., 2-hydroxyaroyl-N-(thiazol-2-yl)amides] against hepatitis B virus replication, with QSAR analysis of our results. The prototypical thiazolide, nitazoxanide [2-hydroxybenzoyl-N-(5-nitrothiazol-2-yl)amide, NTZ] 1 is a broad spectrum antiinfective agent effective against anaerobic bacteria, viruses, and parasites.

Tricyclic 2'-C-modified nucleosides as potential anti-HCV therapeutics.

Promising biological activity in a number of therapeutic areas has been reported for both tricyclic nucleosides and 2'-modified nucleosides. In particular, disubstitution at the C-2' position of nucleosides has resulted in significant activity against the hepatitis C virus (HCV). Combining this with the observation that tricyclic nucleosides developed in our laboratory have been shown to inhibit the RNA-dependent RNA polymerase NS5B led to the design of a series of 2'-modified tricyclic nucleosides.

Evaluation of the in vitro anti-HBV activity of clevudine in combination with other nucleoside/nucleotide inhibitors.

Background: To reduce the incidence of drug resistance and to maintain viral suppression, patients chronically infected with HBV might require combination therapy using two or more drugs with different resistance profiles. We investigated the activity of clevudine (CLV) in combination with other nucleoside/nucleotide analogues to determine if these combinations were compatible in vitro.

Methods: Using the HepAD38 cell line, which expresses wild-type HBV, and a real-time PCR assay, we tested the anti-HBV activity of CLV in combination with entecavir, lamivudine, adefovir, tenofovir and telbivudine (TBV).