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Biomedical subjects

S Balasubramaniam

Publications and source records attributed to S Balasubramaniam.

At least 37 records · Page 2Linked to original sources
PubMed1988

Shotgun wound ballistics.

Shotguns are popular world wide and more of these weapons exist than the rifled types. With an increasing incidence and prevalence of gunshot wounds it is important for traumatologists to be familiar with shotgun wound ballistics. Shotgun wounds differ from those of other missiles because the spectrum of wound severity is large owing to the fact that the pellets scatter as they travel. Close-range shotgun wounds can be as destructive as those from a high-velocity rifle, but longer weapon-victim ranges may produce only minimal injury. The type of shot (size and weight of pellets) used also determines the type of injury, with more serious injuries produced by the larger type of buckshot (greater than 0.14 inches in diameter). The severity of injury from birdshot depends mainly on the "effective" weapon-victim range which can be calculated from the shot size and shot pattern either clinically or from X-ray. Wounds may then be classified according to severity, yielding information on prognosis and extent of investigation and treatment required. We propose a four-level severity scale based upon birdshot pellet scatter patterns which correlate well with morbidity and mortality rates.

Firearms↗
PubMed1987

Chylomicrons and chylomicron remnants in coronary artery disease: a case-control study.

Epidemiologic studies of coronary artery disease have largely overlooked the role of triglyceride-rich lipoproteins circulating in the post-prandial state. We have conducted a case-control study in males which examined fasting plasma lipoproteins and lipoproteins circulating 4 h after ingestion of a test meal containing fat and cholesterol. The cases were 82 subjects with coronary artery disease confirmed by angiography, while there were two control groups: one group of 38 'hospital controls' free of significant coronary disease by angiography, and a second group of 61 'workforce controls' free of coronary disease on historical grounds. Mean plasma and LDL cholesterol levels were significantly higher and HDL cholesterol levels were significantly lower in cases than in controls. The apo-B48/apo-B100 ratio in lipoproteins Sf greater than 60 obtained 4 h post-prandially, a relative measure of chylomicron and remnant presence, was significantly higher in cases than in controls. After pooling of all data, the prevalence of coronary artery disease was found to increase progressively with the concentration of plasma cholesterol and triglycerides, total cholesterol/HDL cholesterol ratio and the apo-B48/apo-B100 ratio in Sf greater than 60, the relative risk being highest for total cholesterol/HDL cholesterol ratio. After controlling for the confounding effects of age and other lipid factors via multiple logistic regression, apo-B48/apo-B100 ratio was still a significant predictor of coronary artery disease presence (z = 1.97, P less than 0.05) in a 'dose-response' fashion. The risk of coronary artery disease in the top quartile of apo-B48/apo-B100 distribution was 2.2-fold greater than that for the bottom quartile, after adjustment for the effects of other risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Base station prehospital care: judgement errors and deviations from protocol.

During a three-year period 5,944 paramedic runs were reviewed at the King/Drew Medical Center for deviations from prehospital management protocols established by the Los Angeles Paramedic Training Institute, and from standard medical practice. An overall compliance to the prehospital management protocols of 94% was found. Compliance to standard medical care was 97%. The most common deviations were failure to administer prophylactic lidocaine to patients having chest pain suggestive of myocardial ischemia and failure to apply cervical spine precautions in patients with suspected head trauma. Fifty percent of the radio operators who deviated from algorithms also were found to be making errors in judgment in standard medical care.

Algorithms↗
PubMed1987

Maintenance of plasma triglyceride-lowering through use of low-dose fish oils in the diet.

The ingestion of large doses of fish oil may be associated with a marked reduction in plasma triglyceride concentrations. The present study was a preliminary evaluation of whether a lower maintenance dose of fish oils in hyperlipidemic patients would be sufficient to sustain therapeutic effects already achieved on higher dosage over a prior period of three months or longer. For the purposes of this study, 10 or 16g/day of fish oil (LipitacR) was defined as high dosage, 6g/day as medium dosage and 3g/day as low dosage. Five subjects entered on high dosage and were subsequently evaluated on medium and then on low dosage at intervals of six weeks. Five subjects entered on medium dosage and were evaluated after six weeks on low dosage. Seven of the subjects entered with a significant degree of hypertriglyceridemia while the remainder had hypercholesterolemia. Subjects entering with background triglyceride concentrations in excess of 2mmol/l showed reduced triglyceride concentrations at all dose levels, while two subjects with entry triglycerides in excess of 10mmmol/l experienced further improvement in plasma triglycerides when comparing medium with low dosage, or high with medium dosage. Low dose fish oil appears to have potential as a form of maintenance therapy in the management of moderate degrees of hypertriglyceridemia.

Adult↗
PubMed1986

Quantification of LDL cholesteryl ester contribution to biliary steroids in the rat.

The proportion of LDL cholesteryl ester converted to biliary steroids was quantified in the rat. The pre-existing pool of bile was allowed to drain for 10-12 h through a bile duct cannula. A single intravenous pulse injection of LDL labelled with [3H]cholesterol linoleyl ester was made, followed by a constant infusion of the same material in order to maintain constant specific radioactivity in plasma. A new steady state was achieved within 6 h and bile samples were then collected hourly until 12 h. Although substantial amounts (53-61 micrograms/h) of cholesteryl ester were released into the liver during LDL catabolism, only a very small fraction (0.8-1.90 micrograms/h) was found in biliary steroids. The proportion of LDL cholesteryl esters contributing to biliary steroids was only 1-2%. These results perhaps explain why perturbations to accelerate bile acid excretion have no effect on plasma LDL cholesterol concentration in the rat.

Animals↗
PubMed1986

Regulation of low-density-lipoprotein metabolism in the rat.

The mechanism of regulation of plasma low-density-lipoprotein (LDL) metabolism in the rat was studied under a number of experimental conditions. LDL clearance and uptake in the liver was measured after intravenous pulse injection of [14C]sucrose-labelled LDL alone or in combination with reductively methylated [3H]sucrose-labelled LDL. Hyperthyroid rats showed a significant increase in fractional catabolic rate (FCR) and the proportion of LDL degraded in the liver, whereas the synthetic rate of LDL increased by 50%. Receptor-mediated clearance increased 2-fold. Hypothyroid rats showed a significant increase in LDL concentration. The FCR and proportion of LDL degraded in the liver were decreased significantly. Receptor-mediated clearance was also reduced. Cholesterol feeding increased chylomicron, very-low-density-and intermediate-density-lipoprotein cholesterol concentrations, but there was no change in the LDL concentration, FCR or the synthetic rate of LDL. Cholestyramine feeding did not induce changes in the kinetic parameters. These results indicate that, in the rat, the hepatic LDL-receptor pathway is under hormonal control, whereas cholesterol and cholestyramine feeding have no demonstrated effect on LDL metabolism.

Animals↗
PubMed1986

Effects of Ro 16-0521 on cholesterol metabolism in the rat.

Ro 16-0521 is a newly synthesized benzodiazepine derivative which is devoid of reactivity with the brain benzodiazepine receptor. The effects of this drug on plasma lipids and lipoproteins and hepatic cholesterol metabolism have been examined in the cholesterol-fed rat. Drug therapy was associated with dose-related falls in plasma cholesterol concentration, liver cholesterol content, and the activity of the liver enzyme Acyl-CoA cholesterol acyltransferase. Drug therapy abolished the lipid and lipoprotein changes induced by cholesterol feeding, including those associated with a diet supplemented with olive oil to facilitate cholesterol loading. Drug therapy was also associated with an increased activity of the enzyme HMG-CoA reductase and reduced hepatic microsomal cholesterol content. It is suggested that the cholesterol-fed rat will be a suitable model for further mechanistic studies.

Animals↗
PubMed1985

On the effects of dietary n-3 fatty acids (Maxepa) on plasma lipids and lipoproteins in patients with hyperlipidaemia.

An encapsulated preparation of fish oil (Maxepa) was administered to hyperlipidaemic patients in order to establish the responsiveness of the common lipid phenotypes to dietary supplementation with n-3 fatty acids. 13 patients took 6 g/day of fish oil and 12 patients took 16 g/day in a randomized, double-blind crossover study, whereby each subject took fish oil for 3 months and matching placebo for 3 months. The study was conducted against a background diet restricted in saturated fat and cholesterol. In Types IIa and IIb hyperlipoproteinaemia there was no substantial fall in plasma cholesterol concentration. Plasma triglyceride concentrations were reduced significantly in Types IIb and IV (28% and 41% respective reductions). In a separate study using 16 g/day of fish oil in patients with Type V hyperlipoproteinaemia, plasma triglycerides were reduced by 58% and plasma cholesterol concentration by 34%. The change in plasma triglyceride concentration was significantly correlated with the basal triglyceride level (r = -0.94), and was dose-related (33% fall on 6 g/day and 58% fall on 16 g/day). The fall in plasma triglyceride concentration was accompanied by a significant reduction in the concentration of very low-density lipoprotein cholesterol (-42%), a significant rise in low density lipoprotein cholesterol (+7%), and a significant rise in high-density lipoprotein cholesterol concentration (+6%), there being no significant change in the ratio of low density to high density lipoprotein cholesterol. There were changes in the fatty acid composition of plasma and platelet lipids which reflected dietary supplementation with n-3 fatty acids, notably an increase in the proportion of eicosapentaenoic and docosahexaenoic acids which occurred in a dose-dependent fashion. Despite these changes there was no significant variation in the bleeding time, platelet count or blood viscosity during the treatment.

Adult↗
PubMed1985

Effect of heparin on arterial blood gases.

To evaluate changes in arterial blood gas samples caused by the addition of liquid heparin, 50 patients had three simultaneous blood samples drawn, each with one of three amounts of heparin. The liquid heparin decreased statistically the PCO2, PO2, HCO3, and base excess, while the pH remained unchanged. By using a 2-cc blood sample with a 5-cc glass syringe and a 11/2-inch, 18-gauge needle to draw the heparin solution up to the 2-cc mark, and then completely evacuating it, we found that 0.025 cc of solution remained to coat the syringe. Although this remaining solution would cause a 1.25% error in the blood gas results, the error would be acceptable because it is generally less than the standard deviation of the laboratory results. Excess liquid heparin statistically exaggerated or produced false results consistent with a metabolic acidosis with respiratory compensation. We recommend that the complete evacuation of liquid heparin from the sampling syringe be included when performing an arterial blood gas analysis.

Acidosis↗
PubMed1985

110 bullet wounds to the neck.

Selective management of 110 patients with bullet wounds to the neck resulted in 31 explored and 79 observed. There was an overall mortality rate of 2.7%, well within that reported in the literature, which ranges from 2 to 6%. At our institution, it is believed that a substantial number of patients can be selectively managed, depending on the signs and symptoms, the site and direction of the trajectory, and whether the interval of time between injury and entrance to the hospital is longer than 6 hours. Patients who are stable and lack physical signs of obvious major neck injury are evaluated by diagnostic radiologic and endoscopic techniques. If no significant injury is found, they are admitted for observation. The efficacy of this mode of management is strengthened by savings in the costs of hospitalization, risks of undergoing an additional operation, overall negative exploration rate in the mandatory exploration studies, and our own results of selective management. We do not recommend this form of management for all institutions. It has been found that in this well-staffed teaching hospital with an extensive trauma service, experienced personnel doing careful and repeated physical examinations, in addition to 24-hour availability of radiologic and endoscopic modalities, the policy of selective management of bullet wounds to the neck can be adhered to. Further studies need to be done into the various mechanisms of penetrating neck trauma, separating each mechanism into morbidity, mortality, and treatment.

Adolescent↗
PubMed1985

Reduction in plasma cholesterol and increase in biliary cholesterol by a diet rich in n-3 fatty acids in the rat.

Cholesterol and lipoprotein metabolism were investigated in a group of rats fed a fish oil-supplemented diet, a rich source of n-3 fatty acids. For comparison purposes, other groups of rats were fed either safflower oil (n-6 fatty acids) or coconut oil (saturated fatty acids). Diets were isocaloric and contained identical amounts of cholesterol. Rats fed fish oils for 2 weeks showed a 35% lower plasma cholesterol level than rats fed safflower oil, who in turn showed a 14% lower plasma cholesterol level than those fed coconut oil. The fall in plasma cholesterol level with fish oils was associated with significant falls in low density and high density lipoprotein cholesterol levels, but with no significant change in the ratio of low density to high density lipoprotein cholesterol. The fatty acid compositions of plasma, hepatic, and biliary lipids showed relative enrichment with n-3 fatty acids, reflecting the composition of the diet. The fish oil diet increased the basal secretion rate of cholesterol into bile, but the bile acid secretion rate remained unchanged. It is suggested that n-3 fatty acids reduce the plasma cholesterol level in rats by increasing the transfer of cholesterol into bile.

Animals↗
PubMed1984

Role of the liver in low-density-lipoprotein catabolism in the rat.

Plasma low-density-lipoprotein (LDL) kinetics and hepatic LDL uptake were studied in the rat after an intravenous pulse injection of [14C]sucrose-labelled LDL. Some 96% of injected radioactivity was associated with apoprotein B of LDL (d 1.020-1.050). The disappearance of labelled LDL from plasma was accompanied by a linear increase in the hepatic uptake of LDL, up to 12 h after injection. Oestradiol treatment lowered plasma cholesterol concentration by 58% and the intravascular pool of LDL by 78%. This was associated with a 4-fold increase in the fractional catabolic rate of LDL and a 2-fold increase in the hepatic uptake of LDL. Oestradiol treatment did not significantly change the synthesis rate of LDL; it decreased the skin and lung uptake of LDL, but increased adrenal uptake. These results suggest that the liver plays an important role in the regulation of plasma LDL concentration.

Animals↗
PubMed1984

Efficacy of absorption of sublingual and intravenous Cardio-Green.

To simulate the effect of sublingual injections on pediatric patients, open-chested kid goats were injected sublingually or peripherally with Cardio-Green while being supported by internal cardiac massage. Our study demonstrates that there is statistically a ten-fold lower central blood level after sublingual injection compared to that after use of the peripheral intravenous route. Our experiment casts doubt on whether absorption through the sublingual route is adequate, and shows that if a peripheral intravenous line cannot be started, vigorous attempts should be made to obtain a central line rather than taking valuable time to inject sublingual drugs. Further studies must be done before these results can be applied to clinical situations.

Absorption↗
PubMed1984

Intravenous prochlorperazine for the rapid control of vomiting in the emergency department.

In this study, 40 patients whose active vomiting stemmed from various causes were given 2.5 mg of prochlorperazine by slow intravenous push. If no response was observed within 20 minutes, the dosage was repeated. Of 35 patients, 32 responded to doses of 2.5 to 5.0 mg. Three patients experienced no relief of vomiting while in the emergency department, after a total of 5 mg each, in divided doses. These three patients had received morphine sulphate for acute myocardial infarctions. The mean time to cessation of vomiting was 8.5 minutes, versus 35 minutes for a similar group receiving intramuscular prochlorperazine. This difference was statistically significant using analysis of variance (P less than .05). None experienced extrapyramidal reactions, or developed hypotension. We concluded that 2.5 mg of intravenous prochlorperazine given over one minute is an effective, safe treatment for the control of vomiting in the emergency department, until the etiology of the nausea and vomiting is determined and treated specifically. Further double-blind, controlled studies are warranted.

Adolescent↗