Influence of temporal resolution skills in speech discrimination abilities of older subjects.

Compromised temporal resolving power of the auditory system can be one of the main factors contributing to poor speech perception skills in the elderly. Very few of the earlier studies have systematically examined this aspect. Hence, the current study was designed with the following objectives: 1) To establish normative database of Gaps in Noise (GIN) test in elderly population in an Indian context. 2) To determine the relationship between speech discrimination skills and temporal resolution abilities in elderly individuals with normal hearing sensitivity. Thirty normal hearing elderly individuals (age range: 55-75 years; mean age: 59.86 ± 4.11 years) participated in the study. The audiological evaluation comprised of tympanometry, puretone and speech audiometry (Speech Reception Threshold-SRT, Speech Discrimination Score-SDS) and GIN. The results of the present study revealed mean Gap Detection Threshold (GDT) of 8.7 msec (SD = 3.38) in the right ear and 8.83 msec (SD = 2.86) in the left ear for the older participants. The mean Total Percentage Score (TPS) in the right ear was 47% (SD = 11.92) and 45% (SD = 11.29) in the left ear. These results suggest that temporal resolution abilities are poor in the elderly compared to the young and middle-aged group. There was no significant ear based difference on either GDT or TPS. The GDT was inversely correlated with speech discrimination performance. The TPS was positively correlated with SDS. This study clearly demonstrated a positive relationship between temporal resolution abilities and speech discrimination. The current database might be useful when assessing temporal resolution abilities in hearing impaired elderly individuals. Furthermore, all elderly individuals should undergo temporal resolution evaluation, irrespective of their hearing status, during audiological assessment.

Effect of tetracycline on pancreas and liver function of adult male albino rats.

The effect of tetracycline, at two doses of 50 and 200 mg kg(-1) daily, was studied on pancreatic and liver tissue function for 14 and 21 days in adult male albino rats. For pancreatic function the parameters studied were content of amylase and lipase in pancreas, serum amylase and lipase, serum glucose and faecal fat excretion. For liver function, liver specific enzymes in serum, namely alanine amino transaminase, aspartate amino transaminase and lactate dehydrogenase were estimated. In addition, total lipid, antiperoxidative enzymes and lipid peroxidation were measured in pancreas and liver. The content of amylase and lipase in pancreas showed a small but significant decrease in the rats given 50 mg kg(-1) for 21 days and the decrease was much more significant in those receiving the 200 mg kg(-1) dose. In pancreas free radical levels show a significant increase and reduced glutathione shows a substantial decrease at the 50 mg kg(-1) level and a significant change in these parameters was observed at the 200 mg kg(-1) dose. Antioxidant enzymes, superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase, showed a small but significant decrease in the pancreas of the rats treated with 50 mg kg(-1) tetracycline. A significant decrease in the antioxidant enzymes level was observed at the 200 mg kg(-1) dose. In the liver, free radical levels and reduced glutathione were within the normal range at the 50 mg kg(-1) level and significant changes were observed at 200 mg kg(-1). The antioxidant status was unaffected in liver after treatment with tetracycline at the 50 mg kg(-1) level and a significant decrease was observed at the higher dose. Our results reveal the safe nature of tetracycline with respect to the liver at the lower dose tested, whereas, both the higher and lower doses seem to have detrimental effect on the pancreas as revealed by the rise in free radical levels and decrease in the antioxidant enzyme levels.

Changes in tissue defence system in white spot syndrome virus (WSSV) infected Penaeus monodon.

The present study examined the changes occurring in the pro phenoloxidase system and antioxidant defence status in haemolymph, hepatopancreas and muscle tissue of white spot syndrome virus (WSSV) infected Penaeus monodon. Tiger shrimps (P. monodon) were infected with white spot virus by intramuscular injection of the virus inoculum. Levels of lipid peroxides and the activities of phenoloxidase, glutathione-dependent antioxidant enzymes [glutathione peroxidase (GPX), glutathione-S-transferase (GST)] and antiperoxidative enzymes [superoxide dismutase (SOD) and catalase (CAT)] were determined. WSSV infection induced a significant increase in lipid peroxidation in haemolymph, muscle and hepatopancreas of experimental P. monodon compared to normal controls. This was paralleled by significant reduction in the activities of phenol oxidase, glutathione-dependent antioxidant enzymes and antiperoxidative enzymes. The results of the present study indicate that the tissue antioxidant defence system in WSSV infected P. monodon is operating at a lower rate, which ultimately resulted in the failure of counteraction of free radicals, leading to oxidative stress as evidenced by the increased level of lipid peroxidation.

Protective effect of n-3 polyunsaturated fatty acids concentrate on isoproterenol-induced myocardial infarction in rats.

The protective effect of PUFA concentrate prepared from fish oil on isoproterenol-induced myocardial infarction in male albino rats was investigated with respect to changes in the levels of diagnostic marker enzymes, cholesterol, triglycerides, free fatty acids, phospholipids, reduced glutathione (GSH) and lipid peroxides (LPO). Administration of PUFA concentrate significantly prevented the isoproterenol-induced elevation in the levels of plasma diagnostic marker enzymes (ALT [93.5%], AST [95.6%], LDH [94.7%] and CPK [96.1%]). PUFA concentrate feeding exerted a significant antilipidemic effect against isoproterenol-induced myocardial infarction by reducing the levels of lipid components in plasma (cholesterol [71.5%], triglycerides [79.7%] and free fatty acids [70.7%] and heart tissue (cholesterol [81.4%], triglycerides [76.3%] and free fatty acids [78.6%]). A tendency to prevent the isoproterenol-induced phospholipids depletion (74.4%) in the myocardium of experimental rats was also observed. The level of lipid peroxidation was also found to be significantly lower in PUFA treated animals (2.72+/-0.15nmol/ml in plasma; 1.18+/-0.08nmol/mg protein in heart tissue) as compared to that of isoproterenol-injected groups (5.77+/-0.43nmol/ml in plasma; 2.14+/-0.15nmol/mg protein in heart tissue) of rats. Also the level of reduced GSH significantly higher in the heart tissue of PUFA administered experimental rats (5.65+/-0.98 microg/g) as compared to myocardial infarction induced control rats (2.39+/-0.18 microg/g). The results of the present study indicate that the overall cardioprotective effect of PUFA concentrate is probably related to its ability to inhibit lipid accumulation by its hypolipidaemic property.

Distribution of organochlorine pesticides and heavy metal residues in fish and shellfish from Calicut region, Kerala, India.

Fish collected from five different locations from the Calicut region, India were analysed for the levels of organochlorine pesticides (OCPs) and heavy metal (HM) residues in order to elucidate the status of these chemical contaminants in fish and shellfish meant for human consumption. The highest concentrations of OCPs detected in the edible portion of fish were 10.47, 70.57 and 28.35 ng g-1 wet weight, in marine, brackish water and freshwater, respectively. BHC and heptachlor epoxide formed the major share of OCPs in the marine fish while BHCs contributed to the major share in the freshwater and brackish water fish. The DDT (sum of DDT and its metabolites) ranged from 0.05 to 8 ng g-1 in the samples irrespective of the habitat. Among the HMs, Cu, Zn, Mn and Cr were present in the samples irrespective of the place of collection. About 22% of the samples from the freshwater area contained marginally higher lead content above the legal limit of 0.2-0.4 microg g-1. The Cr content ranged from 0.1 to 1.1 microg g-1 in the fish with marginally higher content in the fish from freshwater and marine regions (0.55-1.1 microg g-1). Mercury was detected in the samples (55%) from marine habitat only. The concentrations of OCPs and HMs in the samples, in general, were below the maximum residual level recommended by various organizations.

Cardioprotective effect of squalene on lipid profile in isoprenaline-induced myocardial infarction in rats.

We studied the cardioprotective effect of squalene on isoprenaline-induced myocardial infarction in male albino rats with respect to changes in the levels of lipid components in plasma and heart tissue. Prior administration of 2% squalene in feed for 45 days significantly reduced the isoprenaline-induced elevation in the levels of cholesterol, triglycerides, and free fatty acids in plasma and heart tissue of rats following myocardial infarction. It exerted an antilipidemic effect by reducing the level of low-density lipoprotein cholesterol with a parallel rise in the level of high-density lipoprotein cholesterol in plasma of experimental rats. A tendency to prevent the isoprenaline-induced depletion of phospholipids in the myocardium of experimental rats was also observed. In the present study, the pretreatment with squalene significantly counteracted the isoprenaline-induced lipid peroxidation and maintained the rats at near normal status. The results of the present study indicate that the overall cardioprotective effect of squalene is probably related to an inhibition of lipid accumulation by its hypolipidemic properties and/or its antioxidant properties.

Anti-ulcerogenic effect of chitin and chitosan on mucosal antioxidant defence system in HCl-ethanol-induced ulcer in rats.

The anti-ulcerogenic effect of chitin and chitosan against ulcer induced by HCl-ethanol in male Wistar rats was studied. Levels of acid output, pepsin, protein, lipid peroxides and reduced glutathione and the activity of glutathione peroxidase (GPx), glutathione-S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) were determined in the gastric mucosa of normal and experimental groups of rats. A significant increase in volume and acidity of the gastric juice was observed in the ulcer-induced group of rats. Peptic activity was significantly decreased as compared with that of normal controls. In the rats pre-treated with chitin and chitosan 2% along with feed, the volume and acid output and peptic activity of gastric mucosa were maintained at near normal levels. The level of lipid peroxidation was significantly higher in the ulcerated mucosa when compared with that of normal controls. This was paralleled by a decline in the level of reduced glutathione and in the activity of antioxidant enzymes like GPx, GST, CAT and SOD in the gastric mucosa of ulcer-induced rats. Also, the levels of mucosal proteins and glycoprotein components were significantly depleted in ulcerated mucosa. The pre-treatment with chitin and chitosan was found to exert a significant anti-ulcer effect by preventing all the HCl-ethanol-induced ulcerogenic effects in experimental rats.

A distance-assisted training program for nuclear medicine technologists.

We have developed training materials for nuclear medicine technologists to be used in distance-assisted training programs. We have completed our first pilot project in Asia and report that there will be nearly 500 students around the world, in Asia, Africa, Central America and South America, using our materials during the coming year.

Physical illnesses among elderly psychiatric out-patients with depression.

Forty elderly psychiatric out-patients with an ICD-9 diagnosis of depression and twenty matched controls were studied for the presence of physical illnesses, using a pre-defined battery of investigative techniques. While the prevalence of physical illness diagnosis was not significantly different between the two groups, the number of subjects with undiagnosed illnesses and those with multiple illnesses was significantly higher among the depressives. Among specific illnesses, hypertension, osteoarthritis and cataract were significantly more common among depressives. Significance of the findings is discussed.

Critical opening pressure and reactivity of tail vessels in conscious hypertensive rats.

The possible role of increased vascular reactivity in the mechanism of experimental hypertension was studied by measurements of the critical opening pressure (COP) of tail vessels in conscious rats. In hypertension induced by administration of desoxycorticosterone acetate (DOCA) and replacement of the drinking water by 1% NaCl solution (DOCA-NaCl hypertension), and in one-kidney Goldblatt renovascular hypertension, the raised level of blood pressure was associated with an increased COP of the tail vessels when measured both before and after ganglionic blockade. In rats treated with either DOCA alone or 1% NaCl alone there was no significant increase in systolic blood pressure (SBP) or COP relative to the corresponding controls. In all four experimental series intravenous infusion of angiotensin or norepinephrine in conscious ganglion-blocked rats produced dose-dependent increases in SBP and COP. In DOCA-NaCl hypertensive rats but not in renovascular hypertensives, nor in rats treated with DOCA alone or 1% NaCl alone, the increase in COP for a given increment in dose of angiotensin or norepinephrine was significantly greater than in the control rats. It is concluded that in DOCA-NaCl hypertension there is a true increase in the reactivity of the smooth muscle of the resistance vessels to angiotensin and norepinephrine. In renovascular hypertension this is not the case and other factors must therefore be involved in causing the increased blood pressure and COP.