Synthesis and anti-HIV activities of bis-(cycloSaligenyl) pronucleotides derivatives of 3'-fluoro-3'-deoxythymidine and 3'-azido-3'-deoxythymidine

Anti-HIV nucleoside monophosphates have limited cellular uptake due to the presence of negatively-charged phosphate group. Bis-(cycloSaligenyl) derivatives containing two anti-HIV nucleosides, 3'-fluoro-3'-deoxythymidine (FLT) and 3'-azido-3'-deoxythymidine (AZT) were synthesized to increase intracellular delivery of nucleoside monophosphates. 2,5-Bis(hydroxymethylene)benzene-1,4-diol was selected as a monocyclic bidentate scaffold and synthesized by three different methods from bis(hydroxymethylene)cyclohexan-1,4-diene-1,4-diol, or diethyl 2,5-dihydroxyterephthalate. The reaction of the tetraol with diisopropylphosphoramidous dichloride in the presence of 2,6-lutidine, followed by conjugation reactions with nucleosides (i.e., FLT and AZT) and oxidation afforded symmetrical and unsymmetrical bis-(cycloSaligenyl) diphosphate triester products, AZT-AZT, FLT-FLT, and FLT-AZT conjugates, in 63-74% overall yields and modest anti-HIV activities (IC₅₀ = 2.8-69.6 µM).

Synthesis, Characterization, and Biological Evaluation of certain 6-methyl-2(3H)-benzo-1, 3-thiazolyl-1'-ethylidene-2-(o, p- Substituted Acetophenones) Hydrazine Analogs

In the present study, five new derivatives (GG4 to GG8) of benzothiazoles were synthesized and evaluated against Staphylococcus aureus (MTCC 737), Pseudomonas aeruginosa (MTCC 424), Escherichia coli (MTCC 1687), and yeast-like fungi Candida tropicalis. p-Toluidine on treatment with ammonium thiocynate formed 2-benzothiazolamines (II), which on reaction with hydrazine hydrate formed a hydrazino derivative (III). Compounds GG4 to GG8 were synthesized by reacting the hydrazine derivative with different acetophenones. All the synthesized compounds were identified by IR and (1)H-NMR, and antimicrobial activity was performed on the synthesized compounds. Presence of NO(2), Br, OCH(3), and Cl groups to the substituted benzothiazole enhanced the antibacterial and antifungal activities.

Cell transformation by v-Rel reveals distinct roles of AP-1 family members in Rel/NF-kappaB oncogenesis

Cell transformation by the v-rel oncogene is mediated by the aberrant expression of genes that are normally tightly regulated by other Rel/NF-κB family members. Although a number of genes inappropriately activated or suppressed by v-Rel have been identified, their contributions to the v-Rel transformation process have been poorly characterized. Here, we examine the role of individual AP-1 proteins in v-Rel-mediated transformation. v-Rel transformed cells exhibit elevated RNA and protein expression of c-Fos, c-Jun, and ATF2 and sustained repression of Fra-2. c-Fos and c-Jun are essential in both the initiation and maintenance of v-Rel-mediated transformation while Fra-2 is dispensable. By employing a c-Jun dimerization mutant, we further identified Fos:Jun heterodimers as major contributors to the v-Rel transformation process. The inability of c-Rel to induce the expression of c-Fos and c-Jun contributes to its weaker oncogenic potential relative to v-Rel. Our studies also demonstrate that v-Rel may induce AP-1 members by directly upregulating gene expression (c-fos and ATF2) and by activating pathways that stimulate AP-1 activity. While elevated expression of ATF2 is also required for v-Rel-mediated transformation, its ectopic overexpression is inhibitory. Investigating the mode of ATF2 regulation revealed a positive feedback mechanism whereby ATF2 induces p38 MAPK phosphorylation to further induce its own activity. In addition, these studies identified Ha-Ras as an effector of v-Rel mediated transformation and reveal a novel role for ATF2 in the inhibition of the Ras-Raf-MEK-ERK signaling pathway. Overall, these studies reveal distinct and complex roles of AP-1 proteins in Rel/NF-κB oncogenesis.

Investigations on DNA damage and frequency of micronuclei in occupational exposure to electromagnetic fields (EMFs) emitted from video display terminals (VDTs)

The potential effect of electromagnetic fields (EMFs) emitted from video display terminals (VDTs) to elicit biological response is a major concern for the public. The software professionals are subjected to cumulative EMFs in their occupational environments. This study was undertaken to evaluate DNA damage and incidences of micronuclei in such professionals. To the best of our knowledge, the present study is the first attempt to carry out cytogenetic investigations on assessing bioeffects in personal computer users. The study subjects (n = 138) included software professionals using VDTs for more than 2 years with age, gender, socioeconomic status matched controls (n = 151). DNA damage and frequency of micronuclei were evaluated using alkaline comet assay and cytochalasin blocked micronucleus assay respectively. Overall DNA damage and incidence of micronuclei showed no significant differences between the exposed and control subjects. With exposure characteristics, such as total duration (years) and frequency of use (minutes/day) sub-groups were assessed for such parameters. Although cumulative frequency of use showed no significant changes in the DNA integrity of the classified sub-groups, the long-term users (> 10 years) showed higher induction of DNA damage and increased frequency of micronuclei and micro nucleated cells.

Synthesis and evaluation of conformationally constrained peptide analogues as the Src SH3 domain binding ligands

Src kinase activity is regulated by the interaction of SH3 domain with protein sequences that are rich in proline residues. Identification of more potent SH3 domain binding ligands that can regulate Src kinase activity is a subject of major interest. Conformationally constrained peptides have been previously used for improving the binding potency of the Src SH2 domain binding peptide ligands and peptide substrates of the substrate-binding site of Src. A series of peptide analogues of Ac-VSLARRPLPPLP (1, Ac-VSL12, Kd=0.34 microM) were synthesized by introducing conformational constraints to improve the binding affinity towards the Src SH3 domain. Peptides synthesized through cyclization between N-terminal to C-terminal [VSLARRPLPPLP] or N-terminal to side chain flanking residues (i.e., [(beta)AVS]LARRPLPPLP and [VSLE]RRPLPPLP) exhibited at least 6.4-fold less binding affinity (Kd=2.19-4.85 microM) when compared to 1. The data suggest upon N-terminal cyclization with C-terminal or flanking residues, the interactions of the amino acids in the core RPLPPLP reduce significantly with the residues within the Src SH3 domain. Conformationally constrained peptide V[SLARRPLPPLP] (5) was synthesized through cyclization of C-terminal to the serine side chain and displayed a comparable binding affinity (Kd=0.35 microM) towards the Src SH3 domain versus that of 1. Thus, this template may be used to optimize and generate more potent analogues with higher stability.

Detection of local community structures in complex dynamic networks with random walks

Identification of interaction patterns in complex networks via community structures has gathered a lot of attention in recent research studies. Local community structures provide a better measure to understand and visualise the nature of interaction when the global knowledge of networks is unknown. Recent research on local community structures, however, lacks the feature to adjust itself in the dynamic networks and heavily depends on the source vertex position. In this study the authors propose a novel approach to identify local communities based on iterative agglomeration and local optimisation. The proposed solution has two significant improvements: (i) in each iteration, agglomeration strengthens the local community measure by selecting the best possible set of vertices, and (ii) the proposed vertex and community rank criterion are suitable for the dynamic networks where the interactions among vertices may change over time. In order to evaluate the proposed algorithm, extensive experiments and benchmarking on computer generated networks as well as real-world social and biological networks have been conducted. The experiment results reflect that the proposed algorithm can identify local communities, irrespective of the source vertex position, with more than 92% accuracy in the synthetic as well as in the real-world networks.

Evaluation of dialysis adequacy in patients under hemodialysis and effectiveness of dialysers reuses

Reuse of dialysers is being practiced since the start of hemodialysis (HD) service in Nepal, which is cost effective as well as safe. A retrospective study was done in Nepal Medical College and Teaching Hospital. We reviewed case records of the year 2008 and retrieved required data such as pre and post urea, post dialysis weight and ultrafiltration volume from 186 sessions of dialysis of 60 patients. Dialysis sessions were divided into nine groups according to the number of use of dialyser. Out of 60 patients, 40 were male. Mean age of the study population was 45.82 +/- 15.42 yrs (range 18-78). Dialysers were reprocessed manually up to 9 times. Adequacy of dialysis was assessed using single pool Kt/v (spKt/v) and urea reduction rate (URR). Mean pre urea, post urea and spKt/v were 160 +/- 51.2 mg/dL, 71.8 +/- 28.5 mg/dL and 0.95 +/- 0.28 respectively. Mean URR was 54.82 +/- 11.24%. Out of total 186 sessions, spKt/v was > or = 1.2 in only 31 sessions (17.0%). There was no significant difference in mean spKt/v between the groups (p=0.87). When compared between the individual groups e.g. 1st vs. 7th, 1st vs. 8th and 1st vs. 9th, there was no significant difference in spKt/v. Dialysis is inadequate in most of our patients undergoing HD twice a week. Reuse of dialyser is effective in urea clearance and the practice of reuse is cost effective and safe.

In-center hemodialysis for end stage kidney disease at Nepal Medical College and Teaching Hospital

End stage kidney disease (ESKD) is defined by glomerular filtration rate (GFR) less than 5 ml/min. These patients need renal replacement therapy (RRT). Hemodialysis is an established form of RRT. Studies on incenter hemodialysis are very few. Here we would like to present our experience on in-center hemodialysis in Nepal Medical College and Teaching Hospital. Study period was one year (1st Baisakh 2065 to 31st Chaitra 2065). Total 33 patients (23 male, 10 female) were enrolled in the study. Average age was 42.33 +/- 15 years. Hypertension (55.0%), diabetes mellitus (24.0%), chronic glomerulonephritis (15.0%), rapidly progressive glomerulonephritis (3.0%) and others (3.0%) were the causes of ESKD requiring dialysis. Hypotension, hypertension, muscle cramps, chest pain were the common complications observed during dialysis. Average haemoglobin level was 9.44 +/- 1.88 g%. Majority of patients were physically inactive. Blood transfusion was the main modality for correction of anaemia. Approximate cost for one session of hemodialysis was Rs. 2000 (U.S. $.25) and average monthly income of study population was Rs.16312.5 (U.S. $.204) U.S. $1 = NRs.80, (4th May 2009).

Nutritional assessment of patients under hemodialysis in nepal medical college teaching hospital

Malnutrition is very common in hemodialysis patients and is predisposed by many factors. Malnutrition is associated with increased morbidity and mortality. Total of 26 patients (16 males and 10 females) who were under hemodialysis in our center were included in the study. With the help of Malnutrition Score (MS) developed by Kalanter-Zadeh, nutritional status of the patients was assessed. Patients also underwent different anthropometric measurements such as Body Mass Index (BMI), Triceps skin fold thickness (TSF), Mid Arm Circumlference (MAC) and Mid Arm Muscle Circumference (MAMC) and laboratory investigations. Mean age of the study population was 42.58 +/- 16.32 years (range 19 to 74 years). Females were older than males. MS of the study population was 15.82 +/- 3.76 (range 9-24). Female patients were having higher MS than males (16.5 +/- 4.11 vs. 15.06 +/- 3.55). Based on MS, 22 patients (84.6%) had mild to moderate malnutrition, 2 (7.7%) patients were having severe malnutrition and remaining 2 (7.7%) had normal nutrition score. Females were having lower BMI, MAC and MAMC but higher value of TSF. Significant negative correlation was present between MS and weight, BMI, MAC and MAMC. Calculated Urea Reduction Ratio (URR) of study population was 57.27 +/- 10.89. URR was higher in females than in males (61.77 +/- 12.74 vs. 54.45 +/- 8.85). Only 23.0% of the study population had URR of >65.0%. Protein Catabolic Rate (nPCR) in our study was 0.77 +/- 0.28 g/kg/day. Malnutrition is very common in our center which is >90% when MS was considered. In our study it negatively correlated with weight, BMI, MAC and MAMC. Dialysis inadequacy was present in around 75.0% of our study population.

Development of Src tyrosine kinase substrate binding site inhibitors

The majority of marketed drugs or drug candidates that target protein kinases and which are currently undergoing clinical trials are ATP binding site inhibitors. The process of designing a selective inhibitor as an ATP mimic is challenging, mainly because of the presence of a large number of protein kinases that show a conserved ATP binding site. The substrate binding site of protein kinases is less conserved than the ATP binding site, and provides an opportunity to design valuable chemical tools which can be utilized to understand the catalytic mechanism of the enzyme, or to develop inhibitors with enhanced specificity. In this review, the latest developments of four classes of substrate binding site inhibitors of Src tyrosine kinase are discussed.

A study on clinico-social factors for sexually transmitted diseases among urban males

This health center based study was conducted to find out the proportion and distribution of clinico-social factors for sexually transmitted diseases among male OPD attanders of urban health centre, Subharti Medical College, Meerut. Out of the total 150 male cases of genital diseases from January to June 2005, 42 were found to be symptomatic for STDs according to syndromic approach. The most common symptom was urethral discharge (35.7%). Illiteracy, trucker's occupation, multiple sex partners, extra marital relationship and non-usage of condom were found to be important socio-clinical factors for STDs.

Prenatal diagnosis of a neonate with fetus in fetu

Fetus in fetu is a rare condition not usually considered in the differential of a neonatal abdominal mass. This article illustrates the importance of prenatal ultrasound in the treatment of this condition as it facilitated the assembly of a multispecialty healthcare team that intervened within days of birth.

Knowledge, attitudes and beliefs about menarche of adolescent girls in Anand district, Gujarat

A questionnaire survey of knowledge, attitudes and beliefs towards menstruation was made in 22 schools in Anand district, Gujarat state. Of 900 schoolgirls aged 11-17 years, only 38.5% felt comfortable about menarche and only 31.0% believed that menstruation was a normal physiological process. Many (37.2%) had not been informed about menarche before its onset and 48.2% felt they were not mentally prepared. The major sources of information were the mother (60.7%) or an elder sister (15.8%); teachers and others relatives played a small role. In this area of India, many families continue the custom of celebrating the first menarche and observing social restrictions.