Targeting HIV-1 Through Molecular Modeling and Docking Studies of CXCR4: Leads for Therapeutic Development

The chemokine receptor CXCR4 is the receptor for several chemokines and major co-receptor for X4 human immunodeficiency virus type-1 strains entry into cell. A three-dimensional model of human CXCR4 was developed by homology modeling using the high-resolution bovine rhodopsin structure as template. Interactions between CXCR4 and flavonoids were investigated using in silico docking studies. The results underscore the potential of these compounds that they may become important new antiviral drugs to combat AIDS. It is worth mentioning also that apart from these existing flavonoids, there are many new compounds that may also be useful as topical agents to inactivate virus, or may act as adjuvants with other antiviral drugs.

The release dynamics of model drugs from the psyllium and N-hydroxymethylacrylamide based hydrogels

In order to utilize the psyllium husk, a medicinally important natural polysaccharide, for developing the novel hydrogels for the controlled drug delivery device, we have prepared psyllium and N-hydroxymethylacrylamide based polymeric networks by using N,N'-methylenebisacrylamide (N,N'-MBAAm) as crosslinker. The polymeric networks thus formed were characterized with scanning electron micrography (SEM), FTIR and thermogravimetric analysis (TGA) techniques to study various structural aspects of the networks and also with the swelling response of the polymeric networks as a function of time, temperature, pH and [NaCl]. Equilibrium swelling has been observed to depend on both structural aspects of the polymers and environmental factors. Maximum P(s) 748.3 was observed at 13.0 x 10(-3)mol/L of [N,N'-MBAAm] in 0.5M NaOH solution. The release dynamics of model drugs (salicylic acid and tetracycline hydrochloride) from hydrogels has also been discussed, for the evaluation of the release mechanism and diffusion coefficients. The effect of pH on the release pattern of tetracycline has been studied by varying the pH of the release medium. In release medium of pH 7.4 buffer the release pattern of tetracycline drastically changes to the extent that mechanism of drug diffusion shifted from non-Fickian diffusion to Fickian diffusion. It has been observed that diffusion exponent "n" have 0.71, 0.67 and 0.52 values and gel characteristic constant 'k' have 1.552 x 10(-2), 2.291 x 10(-2) and 5.309 x 10(-2) values in distilled water, pH 2.2 buffer and pH 7.4 buffer, respectively, for tetracycline release. In solution of pH 7.4 buffer, the rate of polymer chain relaxation was more as compare to the rate of drug diffusion from these hydrogels and it follows Fick's law of diffusion. The value of the initial diffusion coefficient for the release of tetracycline hydrochloride was higher than the value of late time diffusion coefficient in each release medium indicating that in the start, the diffusion of drug from the polymeric matrix was fast as compare to the latter stages.

Effect of complete and skeleton photoperiods in baya weaver, Ploceus philippinus

A study was performed to investigate the effects of complete and skeleton photoperiods on gonadal stimulation in baya weaver, Ploceus philippinus. In August 2003, five groups of acclimatized birds (n = 7 each) were exposed to 6L: 13D: 1L: 4D, 6L: 6D: 1L: 11D, 11L: 13D and 13L: 11D. Birds were refractory and their exposure to 6L:13D:1L:4D, 6L:6D:1L:11D, 11L:13D and 13L:11D did not evoke any response. This clearly indicates that the birds were insensitive to the stimulatory effects of these photoperiods and perceived them as short days. An attempt was made to test the responsivity by subjecting all these groups to long day exposure after 16 weeks of experiment. Under 16L: 8D, birds did not show a response during the first 4 weeks of exposure (week 16 to week 20), but thereafter there was a significant photoinduction except 11L:13D (week 24), but the rate and magnitude was different. Until the end of the experiment (32 weeks), all groups of birds had maximum testicular volume except 11L:13D. Birds pre-exposed to 6L:13D:1L:4D, 6L:6D:1L:11D, 11L:13D and 13L:11D responded to 16L:8D, which suggests that these photoperiods helped the birds in recovering their photosensitivity. The results from this experiment indicate that baya weaver interprets a light period depending when the light falls relative to its endogenous circadian system.

Long-term follow-up (11 years plus) results of JRI (Furlong) total hip arthroplasty in young patients: cause for concern regarding acetabular cup?

We describe the clinical and radiological long-term outcomes of 77 primary total hip replacements in 69 patients using the fully hydroxyapatite-coated JRI (Furlong) total hip replacement. The total cases followed up were 77 hips, performed at a mean duration of 11 years and 2 months. Twelve hips could not be followed up for various reasons, which are discussed in the results section. The mean Harris hip score was 89. Seventeen acetabular cups were revised for aseptic loosening. Only one femoral stem was revised, for fracture. By Engh's criteria there were a further two unstable cups with no symptoms, and all femoral stems were stable. Kaplan-Meier survivorship analysis revealed a survival of 98.8% for the femoral stem, 78.7% for the acetabular cup, and a combined survival of 77.8% for both components. Our findings suggest that the JRI (Furlong) hip gives a durable femoral stem implant fixation, whereas the prosthesis-bone interface achieved with the acetabular component is questionable.

Adsorption of phenols from wastewater

The present work involves an investigation of the possible use of coal, residual coal, and residual coal treated with H3PO4 as a means of removal of phenol from wastewater. The study was realized using batch experiments, with synthetic wastewater having phenol concentration of 1000 ppm. Other low-cost adsorbents such as petroleum coke, coke breeze, rice husk, and rice husk char have also been used. The effect of system variables such as pH, contact time, and temperature has been investigated. The suitability of the Freundlich, Langmuir, and Redlich-Peterson adsorption models to the equilibrium data was investigated for each phenol-adsorbent system. The results showed that the equilibrium data for all the phenol-sorbent systems fitted the Redlich-Peterson model best. Kinetic modeling of removal of phenols was done using the Lagergren first-order rate expression. A series of column experiments were performed to determine the breakthrough curves.

Efficacy and safety of citalopram versus amitriptyline in the treatment of major depression

BACKGROUND

Double-blind clinical trials comparing citalopram with amitriptyline or other tricyclic antidepressants are lacking in India.

AIM

To evaluate the efficacy and safety of the newer antidepressant citalopram in the treatment of major depression.

METHODS

The clinical acceptability and safety profile of citalopram was assessed and compared with that of amitriptyline in 40 patients in an outpatient set-up. Patients aged 18 to 65 years who fulfilled the diagnostic criteria for a single or recurrent major depressive disorder (as defined by DSM-IV) for a minimum of 2 weeks were enrolled. Patient assessment was done at screening, baseline, end of week 1, week 2, week 3, week 4, week 5 and week 6 for efficacy and safety parameters such as Hamilton Depression Rating Scale (HDRS), Clinical Global Impression (CGI) Scale, adverse event follow up, blood pressure and pulse. Three-level statistical analysis including ANOVA was performed on all efficacy measures.

RESULTS

On the HDRS the percentage reduction in the mean score for the citalopram group (Group 1) was 72.12%, while that for the amitriptyline group (Group 2) was 67.93%. On the CGI-Improvement Scale, the percentage reduction at the end of the study for the citalopram group was 56.79% while in the amitriptyline group it was 44.70%. Twenty per cent of patients in Group 1 reported adverse events compared to 75% in Group 2.

CONCLUSIONS

Citalopram is effective in the treatment of major depression at the dosages range of 20-60 mg/day and its efficacy is equivalent to that of standard tricyclic antidepressants such as amitriptyline, with a substantially better tolerability profile.

Anatomical study on true hermaphroditism in an Indian pig (Sus scrofa domesticus)

A pig was confirmed to be a true hermaphrodite on the basis of gross and histomorphological studies of the genital organs. The genitalia was consisted of left ovary, oviduct, two coiled uterine horns, body of uterus along with right testis and an epididymis. Vagina and vulva were absent but male urethra with prostate gland was present. Grossly the size of all the genital organs appeared to be normal. Histomorphologically, testis and epididymis were underdeveloped as there was no clearcut spermatogenia and sertoli cells but Leydig cells were normal. The ovary presents normal histological features with some portion of testicular tissue. Degeneration of uterine epithelium was observed along with normal endometrial glands.

The effect of recent trauma on serum complement activation and serum C3 levels correlated with the injury severity score

PURPOSE

The objective of this prospective pilot study was to estimate serum C3 levels and complement activation within 12 hours of injury and to correlate them with abbreviated injury score (AIS) so as to predict the outcome of injury in terms of mortality or sepsis.

METHODS

The test group (n=30) of patients with < 12 hours of injury were assessed by the AIS-80 and compared with a control group (n=10). Serum C3 levels were estimated by the single radial immunodiffusion technique and complement activation by both two-dimensional and counter immuno-electrophoresis. Statistical analysis was performed using the correlation regression analysis and the minimum discrimination information statistics (MDIS) analysis.

RESULTS

Serum C3 levels were not reduced in patients with injury severity score (ISS) < 12 (n=7). There was a statistically significant difference of serum C3 levels in patients with ISS between 12 and 29 (n=15) and in patients with ISS more than 29 (n=9). Complement activation also correlated well with ISS (p < 0.05). Complement activation and serum C3 levels were found to influence subsequent development of septic complications in the post injury period, being significantly lower in patients who developed septic complications. Complement alterations in trauma patients were a direct result of the trauma since they were not seen in patients undergoing surgery.

CONCLUSIONS

ISS is a good prognosticator of outcome of trauma and serum C3 levels and complement activation are good predictors for mortality and development of septic complications in recently injured patients. These may prove to be effective parameters in the management of the patients with injury.

Biological treatment of textile dye Acid violet-17 by bacterial consortium in an up-flow immobilized cell bioreactor

AIMS

To develop a cost effective and efficient biological treatment process for small scale textile processing industries (TPI) releasing untreated effluents containing intense coloured Acid violet-17 (AV-17), a triphenyl methane (TPM) group textile dye.

METHODS AND RESULTS

The samples collected from effluent disposal sites of TPI were used for selective enrichment of microbial populations capable of degrading/decolourizing AV-17. A consortium of five bacterial isolates was used to develop an up-flow immobilized cell bioreactor for treatment of feed containing AV-17. The bioreactor, operating at a flow rate of 6 ml x h(-1), resulted in 91% decolourization of 30 mg AV-17/l with 94.3 and 95.7% removal of biochemical oxygen demand and chemical oxygen demand of the feed. Comparison of the input and output of the bioreactor by UV-visible, thin layer chromatography and (1)H-nuclear magnetic resonance spectroscopy indicates conversion of the parent dye into unrelated metabolic intermediates.

SIGNIFICANCE

These results will form a basis for developing 'on-site' treatment system for TPI effluents to achieve decolourization and degradation of residual dyes.

Biodegradation of acid blue-15, a textile dye, by an up-flow immobilized cell bioreactor

Acid blue-15, a complex and resonance-stabilized triphenylmethane (TPM) textile dye, resistant to transformation, was decolorized/degraded in an up-flow immobilized cell bioreactor. A consortium comprised of isolates belonging to Bacillus sp., Alcaligenes sp. and Aeromonas sp. formed a multispecies biofilm on refractory brick pieces used as support material. The TPM dye was degraded to simple metabolic intermediates in the bioreactor with 94% decolorization at a flow rate of 4 ml h(-1).

Hypolipidemic effect of different extracts of Clerodendron colebrookianum Walp in normal and high-fat diet fed rats

Clerodendron colebrookianum Walp (family, Verbenaceae) has been used as a home remedy by the Mizo people of north eastern (NE) region of India in their folklore medicine as a cardioprotective (mainly against high blood pressure) agent. The scientific basis for their use has yet to be established. Therefore, in this investigation an attempt has been made to study the effect of different extracts of the leaves of Clerodendron colebrookianum Walp (CC) on serum lipid profile which is closely associated with many cardiovascular diseases. It was found that after administration of both crude and organic extracts the serum lipid profile, i.e. total cholesterol (TC), triglycerides (TG) and low density lipoprotein (LDL) lowered significantly (P<0.001) from their respective control except TG in methanol extract (ME)-treated rats. The decreased percentage of TC, TG and LDL after administration of crude extract (CE) and ethylacetate extract (EE) with normal diet were found to be 35, 39 and 48%, and 33, 18 and 91%, respectively, after 7 days of treatment. In case of ME the lowering of TC and LDL were noted to be 41 and 85%, respectively. Both TC and TG were lowered significantly (P<0.001) even after the administration of crude extract against high-fat diet. Significant increase of cardioprotective lipid, i.e high density lipoprotein (HDL) after administration of EE (46%) and ME (38%) was another interesting finding of this experiment. Total cholesterol:HDL and LDL:HDL ratios were significantly lower in the experimental group. Therefore, it was concluded that the leaves of CC have definite cardioprotective potentiality, and there is a valid scientific basis for consuming it for better health in NE region of India.