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Biomedical subjects

M S Reddy

Publications and source records attributed to M S Reddy.

At least 109 records · Page 6Linked to original sources
PubMed1990

Impact of methylparathion and malathion on cholinergic and non-cholinergic enzyme systems of penaeid prawn, Metapenaeus monoceros.

The nervous tissue AChE, BUChE and glutaminase activity levels were significantly inhibited, whereas glutamine synthetase activity, acetylcholine and glutamine contents were increased significantly following the sublethal exposure of prawn, Metapenaeus, monoceros to methylparathion and malathion. During OPI exposure ammoniagenesis was triggered by increased deamination of purines and oxidative deamination of glutamate. This results in the hyperammonemia. As a consequence of hyperammonemia, the OPI exposed prawn tissue have adopted the suitable mechanisms to detoxity the ammonia by enhancing the synthesis of urea and glutamine. From the study, it has been observed that 10 days of reclamation period is not enough but the prawn nervous tissue showed efficient mechanisms for the detoxification or biodegradation of OPI molecules, which will pave way for the successful survival prawns.

Acetylcholine↗
PubMed1990

Toxic impact of phosphamidon on acid phosphatase of prawn, Metapenaeus monoceros (Fabricius).

Activity levels of acid phosphatase (ACPase) in midgut gland and muscle tissues of penaeid prawn, Metapenaeus monoceros were studied after exposure to selected sublethal concentrations of phosphamidon after acute and chronic exposure. Phosphamidon was found to elevate the activity levels of ACPase in the selected tissues. The rate of elevation of ACPase is dose-dependant and is more at higher concentrations. Acute and chronic exposure to phosphamidon creates disturbances in the normal functioning at the cellular level in the tissues of prawn, M. monoceros.

Acid Phosphatase↗
PubMed1990

Assessment of adjunctive flurbiprofen therapy in root-form implant healing with digital subtraction radiography.

The goals of these case reports were to (1) apply digital subtraction radiography to the assessment of the healing of root-form implants so that small changes in bone height and density could be detected and (2) to compare the bony support around root-form implants in patients prescribed the non-steroidal anti-inflammatory drug, flurbiprofen, with support in patients who did not receive the flurbiprofen as adjunctive therapy. Titanium root-form implants were surgically placed in four patients who were randomly assigned to receive either 100 mg flurbiprofen twice a day for three months or no flurbiprofen (as controls). Radiographs were taken immediately post-operatively and at four months. Digital subtraction radiography was used to detect sites of bone gain, loss, or unchanged bone around the implant. This four-month pilot study suggests that the non-steroidal anti-inflammatory drug, flurbiprofen, appears to be associated with increased bone density surrounding dental implants, and that digital subtraction radiography may be useful for the evaluation of bone density changes around dental implants.

Bone Density↗
PubMed1990

Recovery of carbaryl inhibited AChE in penaeid prawn, Metapenaeus monoceros.

The acetylcholinesterase activity in selected tissues of prawn, Metapenaeus monoceros showed a significant inhibition during commercial (CgC) and technical (TgC) grade carbaryl exposure. The rate of inhibition of AChE in nervous and non-nervous tissues is more under CgC over TgC exposure, suggests the involvement of emulsifier system for easy penetration of CgC molecule, which is absent in TgC. A progressive recovery of AChE activity from TgC and CgC induced inhibition was in the tissues within 10 days after the transfer of prawns to toxicant free water i.e., recovery or reclamation period. From the study, it has been observed that the inhibition of AChE activity is still persists evenafter 10 days of reclamation period, gives the idea of carbaryl accumulation at the cellular level or the reclamation period is not sufficient for the restoration of normalcy of AChE activity.

Acetylcholinesterase↗
PubMed1990

In vitro inhibition of Ca+2 ATPase by methylparathion in prawn: a kinetic approach.

After in vitro addition of IC50 concentration of methylparathion on Ca+2 ATPase in nervous and hepato-pancreatic tissues of prawn were studied. The inhibitory pattern of Ca+2 ATPase elucidate the interaction of methylparathion with ATPase system. The significant decrease in maximal velocity (Vmax) without appreciable change in apparent Michaelis-Menten constant (Km) suggests that the impact of methylparathion on Ca+2 ATPase is independent of substrate and is of a classical non-competitive type.

Animals↗
PubMed1989

Characterization of a polysaccharide antigen from Bacteroides gingivalis.

A polysaccharide Ag (PS) was isolated from the phenol-water extract of Bacteroides gingivalis strain A7A1-28 and separated from LPS by Sephacryl S-400 HR chromatography. The PS was composed of glucose, glucosamine, galactosamine, and galactosaminuronic acid, while the LPS contained rhamnose, mannose, galactose, glucose, glucosamine, galactosamine, phosphate, and lipid, but not galactosaminuronic acid. The PS and LPS were immunochemically distinct by immunoelectrophoresis in agarose with homologous rabbit antiserum. The phenol-water extract from strain A7A1-28 was immunoreactive by immunoelectrophoresis against antisera to three additional strains of B. gingivalis, however, the PS was only reactive with homologous serum. Immunochemical characterization of decarboxylated and deacetylated PS derivatives suggest that the acetylation of the amino sugars, but not the presence of the carboxylate residue on galactosaminuronic acid contributes to major immunodeterminant expression.

Antigens, Bacterial↗
PubMed1989

Lubrication of selected salivary molecules and artificial salivas.

The lubrication regime displayed by human salivas (parotid and submandibular-sublingual), purified salivary molecules (the mucins MG1 and MG2 and alpha-amylases), and selected artificial salivas (Oracare D, Saliva Substitute, and Orthana) was assessed in vitro using a friction-testing device. Thin-film (boundary) lubrication was observed for all of the salivary samples and two of the artificial salivas examined. Oracare D, a glycerol-based artificial saliva, was the exception since it lubricated by a thick-film (hydrodynamic) regime. On a molar basis, the best lubricants of the purified salivary molecules were MG1 greater than MG2 approximately nonglycosylated alpha-amylases approximately glycosylated alpha-amylases.

Amylases↗
PubMed1989

A combination of platelet-derived and insulin-like growth factors enhances periodontal regeneration.

The combination of platelet-derived growth factor (PDGF) and insulin-like growth factor one (IGF-1) has previously been shown to enhance repair of soft tissue wounds. Here we report initial observations following application of PDGF and IGF-1 to periodontitis-affected teeth in beagle dogs. 1 micrograms of PDGF and IGF-1 in an aqueous gel was applied to the root surfaces of test teeth following open flap debridement. Control sites received the gel alone. Block biopsies of the teeth and surrounding bone were taken 2 weeks after treatment. Histologic analyses of control specimens revealed a long junctional epithelial attachment, and no new bone or cementum formation. In contrast, growth factor treated sites exhibited significant amounts of new bone and cementum formation. A nearly continuous layer of osteoblasts lined the newly formed bone, and there was a dense cellular "front" at the coronal extent of the new bone. These preliminary results suggest that in vivo application of the combination of PDGF and IGF-1 may enhance regeneration of the periodontal structures.

Alveolar Process↗
PubMed1989

Characterization of salivary alpha-amylase binding to Streptococcus sanguis.

The purpose of this study was to identify the major salivary components which interact with oral bacteria and to determine the mechanism(s) responsible for their binding to the bacterial surface. Strains of Streptococcus sanguis, Streptococcus mitis, Streptococcus mutans, and Actinomyces viscosus were incubated for 2 h in freshly collected human submandibular-sublingual saliva (HSMSL) or parotid saliva (HPS), and bound salivary components were eluted with 2% sodium dodecyl sulfate. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western transfer, alpha-amylase (EC 3.2.1.1) was the prominent salivary component eluted from S. sanguis. Studies with 125I-labeled HSMSL or 125I-labeled HPS also demonstrated a component with an electrophoretic mobility identical to that of alpha-amylase which bound to S. sanguis. Purified alpha-amylase from human parotid saliva was radiolabeled and found to bind to strains of S. sanguis genotypes 1 and 3 and S. mitis genotype 2, but not to strains of other species of oral bacteria. Binding of [125I]alpha-amylase to streptococci was saturable, calcium independent, and inhibitable by excess unlabeled alpha-amylases from a variety of sources, but not by secretory immunoglobulin A and the proline-rich glycoprotein from HPS. Reduced and alkylated alpha-amylase lost enzymatic and bacterial binding activities. Binding was inhibited by incubation with maltotriose, maltooligosaccharides, limit dextrins, and starch.

Adult↗
PubMed1989

Altering the progression of human alveolar bone loss with the non-steroidal anti-inflammatory drug flurbiprofen.

The treatment of human periodontal diseases relies on mechanical and antimicrobial suppression of the etiologic bacteria. The ability to alter the progression of periodontitis by additionally blocking host pathways involved in the destructive process is an area of current research. Prostaglandins and other metabolites of arachidonic acid are believed to be important host mediators of the bone resorption of diseases such as periodontitis. We have previously examined the effect of inhibitors of prostaglandin production, non-steroidal anti-inflammatory drugs (NSAIDs), on inhibiting alveolar bone loss in beagles. The present study was designed to examine the effect of the NSAID, flurbiprofen, on slowing the radiographic loss of alveolar bone in the human. Fifty-six individuals with radiographic evidence of alveolar bone loss were recruited for study. Forty-four patients remained in the study for the data analysis of loss of alveolar bone. Following a 6 month baseline pretreatment period to measure the radiographic progression of bone loss, half of the patients were administered flurbiprofen, 50 mg. b.i.d., while half were administered a placebo. All patients received a subgingival scaling and pumice by a hygienist every 6 months. The rate of alveolar bone loss in a 2 year treatment period was compared to the baseline 6 month pretreatment period within and between patient groups. Throughout the study, teeth exhibiting obvious loss of bone were exited from study and treated with conventional mechanical therapy. At the end of the pretreatment period both patient groups had a similar mean rate of alveolar bone loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Modulation of carbohydrate metabolism in the selected tissues of marine prawn, Penaeus indicus (H. Milne Edwards), under phosphamidon-induced stress.

Changes in carbohydrate metabolism were studied in midgut gland, muscle, and gill tissues of marine prawn Penaeus indicus exposed to a sublethal concentration (0.3 ppm) of phosphamidon. A significant decrease in glycogen and pyruvate and an increase in lactate content were observed in all phosphamidon-exposed prawn tissues after 96 hr. An increase in phosphorylase a and aldolase activity levels suggested the increased formation of triose sugars during phosphamidon toxicity. LDH activity was considerably decreased and an increment in lactate content was observed which indicates reduced mobilization of pyruvate into the citric acid cycle. Glucose-6-phosphate dehydrogenase activity was considerably increased, suggesting the enhanced oxidation of glucose in the hexose monophosphate shunt pathway. Krebs cycle enzymes such as NAD-isocitrate dehydrogenase, succinate dehydrogenase, and malate dehydrogenase were found to be decreased, suggesting the impairment in mitochondrial oxidative metabolism due to the acute toxic impact of phosphamidon. Cytochrome-c oxidase and Mg2+ ATPase activity levels were also decreased considerably, suggesting impaired energy synthesis and breakdown during phosphamidon toxicity, as a result of reduced oxidation of glucose aerobically. The increase in acid and alkaline phosphatase activities indicates the enhanced breakdown of phosphate to release energy in view of inhibiton or impairment in the ATPase system during phosphamidon-induced stress. These results suggest that phosphamidon has a profound effect on the oxidative metabolism of prawn which results in the triggering of compensatory metabolic pathways for survivability.

Animals↗