Dipak Kumar De

The repair of segmental bone defects with porous bioglass: an experimental study in goat.

This study was exclusively conducted to evaluate healing of surgically created defects on the radius of adult Black Bengal goat after implantation of porous bioglass blocks and compare the process kinetics with normal healing. Twelve Black Bengal goats were divided randomly into two groups: control and experimental group implanted with bioglass blocks. Unicortical bone defects in radius were generated in all animals under aseptic condition. Local inflammatory reaction and healing of wound, radiological investigations, histological studies, oxytetracycline leveling and angiographic studies were performed up to 90th day post-operatively and compared with normal healing. It has been found that extensive new bone formation originating from host bone towards the implant whereas in control, the process was active from both the ends; the defect site appeared as homogenous nonfluorescent area. Thus, porous bioglass promoted bone formation over the entire extension of the defect independent of size of block in comparison to control group.

Efficacy of nano-hydroxyapatite prepared by an aqueous solution combustion technique in healing bone defects of goat

The present study was undertaken to evaluate porous hydroxyapatite (HAp), the powder of which was prepared by a novel aqueous solution combustion technique, as a bone substitute in healing bone defects in vivo, as assessed by radiologic and histopathologic methods, oxytetracycline labeling, and angiogenic features in Bengal goat. Bone defects were created in the diaphysis of the radius and either not filled (group I) or filled with a HAp strut (group II). The radiologic study in group II showed the presence of unabsorbed implants which acted as a scaffold for new bone growth across the defect, and the quality of healing of the bone defect was almost indistinguishable from the control group, in which the defect was more or less similar, although the newly formed bony tissue was more organized when HAp was used. Histologic methods showed complete normal ossification with development of Haversian canals and well-defined osteoblasts at the periphery in group II, whereas the control group had moderate fibro-collagenization and an adequate amount of marrow material, fat cells, and blood vessels. An oxytetracycline labeling study showed moderate activity of new bone formation with crossing-over of new bone trabeculae along with the presence of resorption cavities in group II, whereas in the control group, the process of new bone formation was active from both ends and the defect site appeared as a homogenous non-fluoroscent area. Angiograms of the animals in the control group showed uniform angiogenesis in the defect site with establishment of trans-transplant angiogenesis, whereas in group II there was complete trans-transplant shunting of blood vessel communication. Porous HAp ceramic prepared by an aqueous combustion technique promoted bone formation over the defect, confirming their biologic osteoconductive property.

Nicotine Diminishes Testicular Gametogenesis, Steroidogenesis, and Steroidogenic Acute Regulatory Protein Expression in Adult Albino Rats: Possible Influence on Pituitary Gonadotropins and Alteration of Testicular Antioxidant Status

The present study was done to evaluate the pituitary-testicular activities of rats subjected to chronic nicotine treatment. The testicular key androgenic enzymes activities, plasma and intratesticular testosterone (ITT) concentrations, and plasma concentration of gonadotropin were significantly reduced by nicotine treatment along with the decreased sperm counts and the disruption of spermatogenesis indicated by significant reduction in the number of different generations of germ cells at stage VII of the spermatogenesis cycle with increased sperm head abnormalities. The Western blot and the reverse transcriptase-PCR analysis revealed that the nicotine induced a marked decrease in the expression of testicular steroidogenic acute regulatory (StAR) protein, which helps in the transfer of cholesterol in mitochondria for the testosterone biosynthesis. The increased testicular lipid peroxidation, plasma concentration of corticosterone, with enhanced hydrogen peroxide and hydroxyl radical generations, as well as decreased glutathione level, reduced antioxidant enzymes activities, and mitochondrial membrane potential (Deltapsi(m)) of testis, were noted after nicotine treatment in rats. Human chorionic gonadotropin or taurine supplementation with nicotine prevented the degeneration of germ cells to some extent, restored spermatogenesis moderately with decreased sperm head abnormalities, and enhanced sperm counts, accompanied with increase in plasma and ITT concentrations, testicular StAR gene expression, and key androgenic enzymes activities. Moreover, taurine supplementation to nicotine-treated animals resulted in the diminution of testicular lipid peroxidation, hydrogen peroxide and hydroxyl radical generations, with the elevation in glutathione level as well as different antioxidant enzymes activities and Deltapsi(m) in testis. The results indicated that nicotine caused testicular toxicity by germ cell degeneration, inhibition of StAR gene expression along with androgen production in adult male rats probably by affecting pituitary gonadotropin, and/or modulating the extent of testicular antioxidant status.

Ethanol induces mouse spermatogenic cell apoptosis in vivo through over‐expression of Fas/Fas‐L, p53, and caspase‐3 along with cytochrome c translocation and glutathione depletion

Although it has been well established that spermatogenic cells undergo apoptosis when treated with ethanol, the molecular mechanisms behind it remain to be investigated. Adult male mice were given intra‐peritoneal injection (IP) of ethanol at a dose of 3 g (15%, v/v) per kg body weight per day during the period of 14 days. Testicular androgenesis and apoptotic germ cell death, along with different interrelated proteins expression, were evaluated. Ethanol treatment induced apoptotic spermatogenic cell death with a decrease in the plasma and intra‐testicular testosterone concentration. Western blot analysis revealed that repeated ethanol treatment decreased the expression of steroidogenic acute regulatory protein (StAR), 3 beta‐hydroxysteroid dehydrogenase (3β‐HSD) and 17 beta‐hydroxysteroid dehydrogenase (17β‐HSD); increased the expression of active caspase‐3, p53, Fas and Fas‐L; and led to up‐regulation of Bax/Bcl‐2 ratio and translocation of cytochrome c from mitochondria to cytosol in testis. It has also been shown in our study that repeated ethanol treatment led to up‐regulation of caspase‐3, p53, Fas, Fas‐L transcripts; increase in caspase‐3 and caspase‐8 activities; diminution of 3β‐HSD, 17β‐HSD, and GPx activities; decrease in the mitochondrial membrane potential along with ROS generation and depletion of glutathione pool in the testicular tissue. The present study has indicated that the ethanol treatment induced apoptosis in the mouse testis through the increased expression of Fas/Fas‐L and p53, up‐regulation of Bax/Bcl‐2 ratio, cytosolic translocation of cytochrome c along with caspase‐3 activation and glutathione depletion. Mol. Reprod. Dev. 77: 820–833, 2010.

Use of ketamine, xylazine, and diazepam anesthesia with retrobulbar block for phacoemulsification in dogs

OBJECTIVE The study was undertaken to evaluate the use of ketamine, xylazine, and diazepam along with a local retrobulbar nerve block for routine phacoemulsification in the dog. Animals Ten clinically healthy mixed-breed dogs of either sex, weighing between 10 and 15 kg. PROCEDURES Ten mixed-breed dogs were selected for unilateral cataract removal by phacoemulsification. Standard preoperative preparations for cataract surgery were followed. Pre-anesthetic medication consisted of atropine sulfate (0.02 mg/kg, SC). Anesthesia was induced by xylazine HCl (1.0 mg/kg, IM) followed by ketamine (5.0 mg/kg, IM). Anesthesia was maintained subsequently with IV ketamine and diazepam to effect and depth of anesthesia was assessed clinically by pedal reflex and jaw reflex. After induction of anesthesia, a retrobulbar nerve block was performed using 2 mL of 2% lignocaine. Eye position was graded after retrobulbar block and IOP was examined preoperative, post-anesthetic, 6 h postoperative and 24 h after surgery. Phacoemulsification was performed using the phaco-chop technique and an intraocular lens was placed. Anesthetic recovery and postoperative recovery following surgery was recorded. RESULT The exposure of the globe in all the dogs was adequate; the desired central fixation of the eye was obtained and surgery could be performed uneventfully. The mean IOP recorded after induction of anesthesia was 15.75 +/- 0.82, which was not significantly (P > 0.01) different from pre-anesthetic values (14.85 +/- 0.85). CONCLUSION Phacoemulsification was successfully performed with this anesthetic regimen without encountering major intraoperative or anesthetic complications.

Turmeric (Curcuma longa) Rhizome Paste and Honey Show Similar Wound Healing Potential: A Preclinical Study in Rabbits

The potential efficacy of fresh turmeric (Curcuma longa) paste to heal wounds was tested in a preclinical study in an animal model. Turmeric paste was comparedwith honey as a topicalmedicament against a control on experimentally created full-thickness circular wounds in 18 rabbits (Oryctolagous cuniculus). Wound healing was assessed on the basis of physical, histomorphological, and histochemical parameters on treatment days 0, 3, 7, and 14. Only tensile strength was measured on day 14 of treatment. It was observed that the wound healing was statistically significantly faster (P < .01) in both treatment groups compared to the control group.