Protective effects of novel diazepinone derivatives in snake venom induced sterile inflammation in experimental animals.

Snake envenomation leads to the formation of damage-associated molecular patterns (DAMPs), which are mediated by endogenous intracellular molecules. These are recognized by pattern-recognition receptors (PRRs) and can induce sterile inflammation. AIMS: In the present study, we aim at understanding the mechanisms involved in DAMPs induced sterile inflammation to unravel the novel therapeutic strategies for treating snake bites. The potential of benzodiazepinone derivatives to act against snake venom induced inflammation has been explored in the present investigation. MAIN METHODS: Three compounds VA 17, VA 43 and PA 03 were taken from our library of synthetic compounds. Oxidative stress markers such as lipid peroxidation, superoxide and nitric oxide were measured along with the analysis of DAMPs (IL6, HMGB1, vWF, S100b and HSP70). These compounds have been docked using molecular docking against the snake venom PLA2 structure (PDB code: 1OXL). KEY FINDINGS: The compounds have been found to effectively neutralize viper and cobra venoms induced lethal activity both ex vivo and in vivo. The compounds have also neutralized the viper venom induced hemorrhagic, coagulant, anticoagulant reactions as well as inflammation. The fold of protection have always been found to be higher in case of ex vivo than in in vivo. These compounds have neutralized the venom induced DAMPs as exhibited by IL6, HMGB1, vWF, S100b and HSP70. The fold of neutralization is found to be higher in VA 43. SIGNIFICANCE: The identified compounds could be used as potential candidates for developing treatment of snakebites in areas where antiserums are not yet available.

Dendrimers as novel systems for delivery of neuropharmaceuticals to the brain.

Most of the newly developed drugs fails to achieve sufficient bioavailability in to brain due to low water solubility and low permeability. Drug delivery systems are one method for achieving entry of molecules to their desired site of action within the body. Dendrimers are the customizable nanopolymers with uniform and well-defined particle size and shape. Dendrimers are of eminent interest for biomedical applications because of their ability to cross cell membranes. This potential pharmaceutical delivery system crosses the blood brain barrier (BBB) and other important target points. The high level of control over the dendritic architecture (size, branching density, surface functionality) make dendrimers ideal carriers in the field of brain drug delivery of anticancer, antiinflammatory, and antimicrobial agents. Examples of dendrimers such as poly(amidoamine) (PAMAM), poly(propylene imine) (PPI) and polyether-copolyester (PEPE), Glyco, PEGylated, peptide and pH dendrimers are of outmost significance. These dendrimers carry the drug molecules by physical interactions (encapsulation) or through chemical bonding (prodrug approach), while pH sensitive dendrimers are able to deliver drug molecules by alteration of ionic exchange in the brain microenvironment at the tumor site. Techniques employing dendrimers could be especially useful for drugs targeting to Alzheimer's and Prion's diseases. The present review should be of value to scientists who wish to work on the dendrimers for the delivery of molecules into the brain by systemic dosing.

Prefabrication of vascularized bone flap induced by recombinant human bone morphogenetic protein 2 (rhBMP-2).

An experimental model for the prefabrication of a vascularized bone flap was developed in this study. To form vascularized bone in the desired configuration and to increase the survival rate of the grafted bone, a muscle vascularized pedicle (MVP) was transformed into vascularized bone by the inducer recombinant human bone morphogenetic protein 2 (rhBMP-2). The muscle flap (8 x 8 mm) raised on saphenous vessels in the rat thigh was sandwiched between same-size collagen (Terudermis) sheets in the presence or absence of impregnated 25 microg of rhBMP-2 for the experimental group and the control group, respectively. The flaps were harvested 1, 2 and 3 weeks postoperatively. Bone transformation was detected by gross examination, radiology, and histologic testing. No evidence of muscle tissue transformation was found in control flaps, whereas all of the experimental flaps produced new bone. Saphenous vessels were observed to supply the new bone upon harvesting, and the newly formed vascularized bone showed good configuration with shape of the Terudermis sheet. This study indicates that this model of effective bone reconstruction could be potentially applied in a therapeutic setting.

In hydronephrosis less than 10 % kidney function is not an indication for nephrectomy in children.

PURPOSE: To reduce the incidence of nephrectomy or hydronephrosis in children. MATERIALS AND METHODS: From September 1998 to October 2000, we treated 58 patients with hydronephrosis; their ages ranged from 35 days to 11 years (mean age 4 years 7 months). All patients were subjected to a DTPA renogram with split function. In 12 patients (study group), kidney function was less than 10 % (range 0 - 10 %). Initially, nephrostomy was carried out in all 12 patients followed by Anderson-Hyne's pyeloplasty after 4 - 6 weeks. Postoperatively renal USG, urine r/m/e & c/s (routine and microscopic examination and culture and sensitivity test), blood urea, serum creatinine were assessed and DMSA scan and DTPA renogram with split functions were carried out in all patients. RESULTS: In the study group, all 12 patients showed improvement of renal function (more than 10 %) after nephrostomy and in all of them pyeloplasty was subsequently carried out within 4 - 6 weeks. There were no significant pre-, peri- or postoperative complications. CONCLUSIONS: Contrary to common practice we do not recommend nephrectomy for hydronephrotic kidneys which show < 10 % of renal function on renogram. The renal functional status improves significantly after a preliminary nephrostomy, thus avoiding the need for a straightforward nephrectomy in children along with all the possible long-term effects of a single kidney.

Bone regeneration using recombinant human bone morphogenetic protein-2 (rhBMP-2) in alveolar defects of primate mandibles.

The efficacy of bone morphogenetic protein (BMP) for bone reconstruction has been widely studied in numerous animal experiments, but insufficient information exists about its ability to regenerate bone in primates. The purpose of this study was to evaluate the effects of recombinant human BMP-2 (rhBMP-2) on bone formation in alveolar bone defects in the mandibles of young primates. Marginal bone defects were created in the mandibles of nine 5-year-old rhesus monkeys and rhBMP-2 permeated in a polylactic-co-glycolic acid-coated gelatin sponge (PGS) was implanted into the bone defects. The resected bone treated with rhBMP-2 regenerated completely at 12 weeks postoperatively, and remodelling and consolidation of new bone were seen histologically. This study provides evidence of considerable bone regeneration in alveolar defects after surgical implantation of rhBMP-2 in non-human primates. This technique may be an effective alternative to autogenous bone grafts for reconstructive surgery in clinical practice.

Prefabricated vascularized bone flap: a tissue transformation technique for bone reconstruction.

In this study, an attempt was made to transform a muscle vascularized pedicle raised on host vessels into a vascularized bone flap, using recombinant human bone morphogenetic protein 2 (rhBMP-2). The purpose of this study was to produce new bone vascularized in nature to increase the survival rate of the subsequently grafted bone and to fabricate the newly formed bone into the desired shape. Silicone molds in the shape of a rat mandible were used to deliver rat bone matrix impregnated with or without rhBMP-2. A muscle pedicle the same size as the mold was raised on the saphenous vessels in the rat thigh and then sandwiched in the center of the silicone molds. The molds were sliced in half and each section was filled with rat bone matrix that was impregnated either with 25 microg of rhBMP-2 for the experimental group or with diluting material alone for the control group. The sandwiched flaps were then secured by tying them to the adjacent muscles and were harvested at 2 and 4 weeks after surgery. Three and six rats were used in the control and experimental groups at each time point, respectively. Bone formation was assessed in the ex vivo specimens by macroscopic, radiologic, and histologic evaluation. Macroscopically, the continuation of the vascular pedicle was clearly visible for both the control and experimental muscle flaps. However, no evidence of muscle-tissue transformation was observed in the control flaps, whereas all the flaps treated with rhBMP-2 produced new bone that replicated the shape of the mold exactly and had saphenous vessels supplying the newly formed bone. This study demonstrates that this experimental model has the potential to be therapeutically applied for effective bone reconstruction.

Viper venom-induced inflammation and inhibition of free radical formation by pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from anantamul (Hemidesmus indicus R. BR) root extract.

The present investigation explored the possible venom neutralizing effect of a pure compound (2-hydroxy-4-methoxy benzoic acid) isolated and purified from the methanolic root extract of Hemidesmus indicus R.Rr. 2-OH-4-MeO benzoic acid possessed potent anti-inflammatory, antipyretic and antioxidant properties. The compound effectively neutralized inflammation induced by Vipera russelli venom in male albino mice and reduced cotton pellet-induced granuloma in rats. The compound produced a significant fall in body temperature in yeast-induced pyrexia in rats but did not change the normothermic body temperature. The compound effectively neutralized viper venom-induced changes in serum phosphatase and transaminase activity in male albino rats. It also neutralized free radical formation as estimated by TBAPS and superoxide dismutase activities. The antisnake venom activity of the pure compound is partly mediated through the above physiological process.

Effects of methotrexate and total body irradiation on mouse lungs.

Separate and combined effects of methotrexate and total body irradiation were studied on normal lungs of mouse. Forty female albino mice weighing 25 to 30 gms were divided into five groups including that of controls. On gross inspection, 70% of lungs of combined therapy group showed signs of congestion, 10% edematous changes and 20% blackish mottling. Microscopic examination revealed marked histopathological changes in the lungs of combined therapy group and milder changes in the methotrexate (Group III) and total body irradiation (Group IV) groups. These findings confirm the enhanced effects of combination of radiations and methotrexate.