Iodinated natural rubber latex: preparation, characterisation & antibacterial activity assessment.

Natural Rubber (NR) in both its latex and dried form was treated with iodine to make it antibacterial in nature. The NR latex was dried and washed, dissolved in toluene, iodinated and cast into films. In a different approach, NR in its latex form (emulsion) was blended with aqueous solution of povidone-iodine complex (PVP-I) and films were cast.

Internalization of HIV-1 tat requires cell surface heparan sulfate proteoglycans.

Tat, the transactivator protein of human immunodeficiency virus-1, has the unusual capacity of being internalized by cells when present in the extracellular milieu. This property can be exploited for the cellular delivery of heterologous proteins fused to Tat both in cell culture and in living animals. Here we provide genetic and biochemical evidence that cell membrane heparan sulfate (HS) proteoglycans act as receptors for extracellular Tat uptake.

Thrombospondin-1/HIV-1 tat protein interaction: modulation of the biological activity of extracellular Tat.

Tat protein, a trans-activating factor of the human immunodeficiency virus type 1, acts also as an extracellular molecule modulating gene expression, cell survival, growth, transformation, and angiogenesis. Here we demonstrate that human thrombospondin-1 (TSP), a plasma glycoprotein and constituent of the extracellular matrix, binds to glutathione-S-transferase (GST)-Tat protein but not to GST. Scatchard plot analysis of the binding of free GST-Tat to immobilized TSP reveals a high-affinity interaction (Kd equal to 25 nM).

The enhanced green fluorescent protein as a tool for the analysis of protein dynamics and localization: local fluorescence study at the single-molecule level.

The green fluorescent protein (GFP) has emerged, in recent years, as a powerful reporter molecule for monitoring gene expression, protein localization and protein-protein interaction. Several mutant variants are now available differing in absorption, emission spectra and quantum yield. Here we present a detailed study of the fluorescence properties of the Phe-64-->Leu, Ser-65-->Thr mutant down to the single molecule level in order to assess its use in quantitative fluorescence microscopy and single-protein trafficking.

Enhanced cardiovascular reactivity to desmopressin in water-restricted rats: facilitatory role of immunosuppression.

There is considerable evidence suggesting that vasopressin may play an important role in regulating cardiovascular homeostasis. In the present study the effects of immunosuppressant drugs, ciclosporin and tacrolimus on arterial blood pressure (BP) and heart rate (HR) responses to desmopressin (DDAVP) were compared in anesthetized normally hydrated and 24-h water-restricted rats. When injected intravenously, single bolus doses of DDAVP (0.

Enigmatic relationship of Pleckstrin homology domain with phospholipid breakdown mediated signal transduction.

Research into phospholipid signaling continues to flourish, as more and more bioactive lipids and proteins are being identified and their actions characterised. The Pleckstrin homology (PH) domain is one such newly recognized protein module thought to play an important role in intracellular signal transduction. The tertiary structures of several PH domains have been determined, some of them complexed with ligands and on the basis of structural similarities between PH domains and lipid binding proteins it has been suggested that PH domains may be binding to lipophilic molecules.

Vasopressin induces dopamine release and cyclic AMP efflux from the brain of water-deprived rats: inhibitory effect of vasopressin V2 receptor-mediated phosphorylation.

The neurohypophyseal hormone vasopressin (AVP) is widely distributed throughout the central nervous system. It acts as an excitatory transmitter in the CNS and plays an important physiological role in water and electrolyte homeostasis. However, water deprivation has been shown to induce changes in the levels of monoamines, but there is little knowledge about the influence of AVP on monoamine levels after water deprivation.

HIV-1 tat transactivator recruits p300 and CREB-binding protein histone acetyltransferases to the viral promoter.

In cells infected with HIV type 1 (HIV-1), the integrated viral promoter is present in a chromatin-bound conformation and is transcriptionally silent in the absence of stimulation. The HIV-1 Tat protein binds to a stem-loop structure at the 5' end of viral mRNA and relieves this inhibition by inducing a remodeling of the nucleosome arrangement downstream of the transcription-initiation site. Here we show that Tat performs this activity by recruiting to the viral long terminal repeat (LTR) the transcriptional coactivator p300 and the closely related CREB-binding protein (CBP), having histone acetyltransferase (HAT) activity.

Fetal growth in maternal anaemia.

The effect of maternal iron deficiency anemia on fetal growth was studied in 54 anaemic (haemoglobin < 11.0 g/dl) mothers. Twenty-two mothers served as controls (haemoglobin > or = 11.

Preparation and antibacterial evaluation of urinary balloon catheter.

Prolonged use of indwelling urinary catheters in bed-ridden patients lead to a variety of Urinary Tract Infections (UTI). The present study deals with the surface treatment of ready-made urinary catheters so as to render them antibacterial in nature. Catheters were treated with varying percentages of iodine in conjunction with natural rubber latex, and their iodide ion release pattern and antibacterial behaviour were evaluated.

Antigenic variation in Foot and Mouth Disease Virus type Asia 1 isolates circulated during 1993-95 in India.

The antigenic variation in Foot and Mouth Disease Virus (FMDV) is very high. The effective strategy to control the Foot and Mouth Disease (FMD) in India which is a habitat of four serotypes O, A, C and Asia 1, is by regular vaccination, using the vaccine strain most suitable for the local situation. India is an endemic country with the disease being widely distributed.

Fetal iron status in maternal anemia.

Hemoglobin, serum iron, transferrin saturation and ferritin were measured on paired maternal and cord blood samples in 54 anemic (hemoglobin < 110 g/L) and 22 non-anemic (hemoglobin > or = 110 g/L) pregnant women at term gestation. The levels of hemoglobin, serum iron, transferrin saturation and ferritin were significantly low in the cord blood of anemic women, suggesting that iron supply to the fetus was reduced in maternal anemia. The linear relationships of these parameters with both maternal hemoglobin and maternal serum ferritin indicated that the fetus extracted iron in amounts proportional to the levels available in the mother.

Studies on the characterization of the subtype(s) of muscarinic receptor involved in prostacyclin synthesis in rabbit cardiomyocytes.

The present study was conducted to localize and characterize the subtype(s) of muscarinic receptor involved in prostacyclin (PGI2) production elicited by the cholinergic transmitter acetylcholine (ACh) in various cell types in the rabbit heart. ACh increased PGI2 synthesis measured as 6-keto-PGF1 alpha, in cultured coronary endothelial cells and freshly dissociated ventricular myocytes in a dose dependent manner but not in cultured coronary smooth muscle cells of rabbit heart. McN-A-343, a partially selective M1 muscarinic ACh receptor (mAChR) agonist, did not alter 6-keto-PGF1 alpha synthesis in these cell types.

A study on the vasopressin induced delay in the gastrointestinal transit in mice: possible mechanism of action.

The effect of arginine vasopressin (AVP) on the gastrointestinal (GI) transit and its possible mechanism were studied using charcoal meal test in mice. A dose related inhibitory effect was recorded. The effect appears to be independent of the time allowed between AVP administration and testing.

Further studies on the anti-nociceptive effect of vasopressin.

The possible interactions of pathways which mediate anti-nociception when stimulated by alpha 2-adrenoceptor agonists and arginine vasopressin (AVP) were investigated. Yohimbine, an alpha 2-antagonist, failed to modify the anti-nociceptive response of AVP. However, clonidine pretreatment, in sub-effective and effective doses, potentiated the anti-nociceptive response of a sub-effective dose of AVP.

Reversal of angiotensin converting enzyme (ACE) inhibitor induced vasodilatation by vasopressin in hindquarters of rat.

The effect of exogenously administered vasopressin was observed on captopril induced vasodilatation in hindquarters of anaesthetised rats. Drops of perfusate were counted for 6 min and mean of the outflow was expressed as drops per min (dpm). In the control group (n = 6) the rate of flow was 9.

Histochemical mapping of alkaline phosphatase in the digestive system of a few teleost fishes.

The alkaline phosphatase activity is mapped in all the parts of the digestive system of Colisa fasciatus, Macrognathus aculeatus, Notopterus notopterus and Nandus nandus. In the posterior region of the alimentary canal of all the 4 fishes the activity is poorer as compared to other parts. In Colisa fasciatus and Macrognathus aculeatus, the activity at the distal end of pyloric caeca is poorer as compared to the proximal part.

Antimalarial phenanthrene amino alcohols. 3. Halogen-containing 9-phenanthrenemethanols.

A series of new 9-phenanthrene amino alcohols has been prepared in which each compound bears from one to five halogen or halogen-containing moieties. A number of these compounds are extremely active against Plasmodium berghei in the mouse. Some structural requirements for optimal efficacy are considered.

Studies on the toxicity of lindane on Colisa fasciatus (part I: TLm measurements and histopathological changes in certain tissues).

1. In the present investigation static bioassay studies and histopathological changes in some tissues (gills, liver and kidney) induced by Lindane 20% E.C.