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Biomedical subjects

E T Koh

Publications and source records attributed to E T Koh.

At least 55 records · Page 3Linked to original sources
PubMed1993

Adult onset polymyositis/dermatomyositis: clinical and laboratory features and treatment response in 75 patients.

OBJECTIVES: To determine possible similarities and differences in clinical and laboratory features and treatment response between patients in Singapore with polymyositis (PM) and dermatomyositis (DM) and reported series. METHODS: Case records of adult patients (16 years old and above) referred to the 3 main electromyographic (EMG) laboratories in Singapore between 1 June 1986 and 31 May 1991 were reviewed if the referring diagnosis was myositis or myopathy for investigation. A computer search for adult patients with a diagnosis of PM/DM (ICD codes 710.3, 710.4, 517.8) who attended the main rheumatology and neurology centre during this period was also carried out. The criteria for PM/DM proposed by Bohan and Peter was adopted. RESULTS: The incidence of PM/DM was 7.7 cases per million population per year. There were 35 PM and 40 DM cases with a median age at diagnosis of 50.7 years (SD: 16.7) and significantly more females in the PM group (p < 0.05). At presentation, 86.7% had proximal myopathy, 34.7% had arthralgia/arthritis and 18.7% had cutaneous vasculitis. The creatine kinase level was elevated in 89.3% of patients and positive EMG and muscle biopsy in 79.4% and 76.4% respectively. Systemic lupus erythematosus was the commonest associated connective tissue disease. The percentage of patients with malignancy was higher in DM compared with PM (p < 0.01) and they were significantly older (mean age 61.8 years) (p < 0.001). Patients who achieved remission were significantly younger (mean age 46.4 years, p < 0.05). The overall mortality rate was 26.7% with infection and malignancy as the main causes of death. CONCLUSION: The results of the study suggest ethnicity does not influence the expression of PM/DM in view of the considerable similarities in frequency and clinical expression of disease in the population studied compared with series from other countries.

Adult↗
PubMed1993

A magnesium-deficient high fructose diet augments bone-sparing action of exogenous oestrogen in ovariectomized rats.

To investigate interactions between circulating oestrogen, high dietary fructose, and low dietary magnesium on bone mineral density and numbers of trabeculae, 10 week old ovariectomized (OVX) and sham-ovariectomized (SOVX) rats were studied. The OVX animals were divided into three groups: one-third of the animals were injected with beta-oestradiol-3-benzoate dissolved in sesame oil twice a week; another one-third were injected with testosterone cypionate; and the remaining OVX and all of the SOVX animals were injected with sesame oil only. One-half of the animals in each group were fed cornstarch without magnesium and the other half, fructose without magnesium. After a 14 week experimental period, a 24 h urine sample was collected for measurements of Ca, Mg, P and cAMP. Blood was collected for determination of Ca, Mg, P, 25-hydroxy- and 1,25-dihydroxy-cholecalciferol. Femurs were used for determination of bone density, and tibiae for numbers of trabeculae. Testosterone-treated and OVX control animals fed cornstarch diets had the lowest bone density, whereas oestrogen-treated and SOVX control rats fed fructose had the greatest bone density. Oestrogen-treated animals fed fructose without magnesium had the highest serum and urinary Ca, whereas testosterone-treated animals fed cornstarch without magnesium had the lowest serum and urinary Ca. Serum alkaline phosphatase was higher in OVX- and testosterone-treated and starch-fed animals as compared to their respective counterparts. High urinary cAMP in OVX- and testosterone-treated animals may reflect the action of increased circulating concentrations of PTH, which could be responsible for bone resorption. The results show that high dietary fructose without magnesium interacts with endogenous or exogenous oestrogen to decrease bone mineral loss significantly in ovariectomized rats.

Animals↗
PubMed1992

Architecture of the suprachiasmatic nuclei in BALB/c and C57BL/6 inbred mouse strains.

Quantitative values representing the length, girth, volume, shape, and cell counts of the suprachiasmatic nuclei (SCN) were measured in BALB/cByJ and C57BL/6J inbred mouse strains, which exhibit a large interstrain difference in the free-running period of their circadian locomotor rhythms. There were no differences in the gross architectural features of the SCN in these two strains.

Animals↗
PubMed1992

Acute surgical abdomen in systemic lupus erythematosus--an analysis of 10 cases.

Gastrointestinal manifestations in a lupus patient may be due to different aetiologies such as vasculitis or a surgical condition. Problems of diagnosis are frequently encountered because the clinical presentations may mimic each other. We analysed ten lupus patients with acute surgical abdomen to identify the clinical, laboratory and radiological features that may aid in early diagnosis and management. Three patients with surgical abdomen had concomitant active lupus. Intra-abdominal sepsis and bleeding peptic ulcer disease constituted two major causes of laparotomies. Overt signs of peritonitis might not be present due to steroid masking effect. There were no specific clinical features, laboratory or radiological tests that could distinguish gastrointestinal vasculitis from acute surgical abdomen. Blood cultures, C-reactive protein and CT abdomen were useful adjuncts in the management of abdominal sepsis. No correlation was found between the timing of surgery, mortality, steroid dosage and wound complication.

Abdomen, Acute↗
PubMed1991

Computer-assisted mapping of immunoreactive mammalian gonadotropin-releasing hormone in adult human basal forebrain and amygdala.

Immunocytochemistry performed on 80-microns unembedded tissue sections was used to study the localization of GnRH-containing neurons and fibers in the basal forebrain and amygdala of six adult (four male, two female) human brains. Sections from one of the female brains were subjected to computer-assisted microscopic mapping to generate a three-dimensional analysis of immunoreactive structures. In all six brains examined, cell bodies were concentrated in the preoptic area and basal hypothalamus, but were also evident in the septal region, anterior olfactory area, and cortical and medial amygdaloid nuclei. GnRH-containing fibers were observed within the hypothalamus (predominantly infundibular region and preoptic area), septum, stria terminalis, ventral pallidum, dorsomedial thalamus, olfactory stria, and anterior olfactory area. Many fibers could also be seen coursing along the base of the brain between the hypothalamus and cortical and medial amygdaloid nuclei. The localization of GnRH-containing cells and fibers in several of these areas represents new observations in the human brain and suggests a role for the amygdaloid complex in the regulation of gonadotropin secretion. The comprehensive view provided by these data may be useful in the clinical application of novel transplantation strategies.

Adult↗
PubMed1991

Dietary fructose produces greater nephrocalcinosis in female than in male magnesium-deficient rats.

The synergistic interaction of fructose and magnesium (Mg) deficiency on kidney calcification was compared in male and female rats. Male and female weanling rats were divided into four dietary groups: fructose or starch, with or without Mg. Rats were fed their respective diets for 9 weeks, and 24 h urine was collected to measure urinary output, pH, Mg, calcium (Ca), and oxalic acid. Rats were fasted overnight. After decapitation, blood was collected immediately, and kidneys were removed to determine their Mg and Ca content. Dietary fructose significantly increased kidney Ca in female rats fed deficient or adequate Mg diet and in male rats fed Mg-deficient diet only; the greatest kidney calcification occurred in female rats fed Mg-deficient diet (P less than 0.0001). Even in starch groups female rats fed the Mg-deficient diet showed some kidney Ca accumulation. The synergistic interaction of fructose and magnesium deficiency on nephrocalcinosis was significantly greater in female than in male rats. Low urinary output, optimal pH 6.8 for calcium phosphate precipitation, hypercalcaemia, hypercalciuria, hypomagnesuria, and low ratio of urinary Mg to Ca may independently or multifactorially contribute to nephrocalcinosis. The possible mechanism of this interaction is discussed.

Analysis of Variance↗
PubMed1990

Comparison of copper status in rats when dietary fructose is replaced by either cornstarch or glucose.

The purpose of this study was to determine what levels of starch or glucose replacement for fructose in the copper-deficient diet (copper) can minimize the fructose-copper interaction. Experimental diets contained either 100% fructose as the carbohydrate source, or the fructose was partially replaced with 50% starch, 50% glucose, 75% starch, or 75% glucose. Diets were either copper adequate (7-8 ppm) or inadequate (less than 1 ppm). Male weanling rats were fed their respective diet for 5 weeks and then fasted overnight. After decapitation, blood was collected and liver and heart were removed. Plasma copper was significantly reduced and ceruloplasmin was not detected in all copper-deficient groups. Copper deficiency increased plasma cholesterol, as well as heart and liver weight in the glucose groups, but not in the starch groups. Those organ weights were heavier in glucose-copper than starch-copper rats. Erythrocyte copper-zinc-superoxide dismutase activity was greater in starch-copper rats. Erythrocyte copper-zinc-superoxide dismutase activity was greater in starch-copper than glucose-copper rats regardless of carbohydrate amount. Hepatic copper concentration of the group fed starch-copper was twice levels observed in glucose-copper. The 50% glucose rats had lower hepatic copper than the 75% glucose rats. Hepatic copper-zinc-superoxide dismutase activity showed patterns similar to hepatic copper. Cardiac copper was greater in starch-copper than glucose-copper rats. Cardiac copper-zinc-superoxide dismutase activity was equally reduced in all copper-deficient groups. The 50% starch-replaced diet was more effective in minimizing copper deficiency than the 75% glucose-replaced diet. This poorer improvement of copper deficiency by glucose than starch may partially be due to a more severe reduction of food intake in glucose than in starch diets.

Animals↗
PubMed1989

Copper status in the rat is affected by modes of copper delivery.

The purpose of this study was to determine whether the interaction between fructose and copper status can be affected by the mode of copper administration. Male Sprague-Dawley rats (n = 94) were fed from weaning diets that contained 0.65-0.85 mg copper/kg diet for 42 d. The experimental design of the study was a 2 x 2 x 3 analysis of variance: two types of carbohydrate (fructose, corn starch), two modes of copper delivery (orally or subcutaneously) and three different extrinsic copper levels (0, 1.5 or 3 mg/kg diet or 0, 11.25 or 22.5 micrograms Cu/d by injection). In the rats fed fructose, direct indicators of copper status such as plasma copper and tissue superoxide dismutase activity were increased to a much greater extent when copper was supplied subcutaneously rather than orally as part of the diet. In the starch-fed rats the effect of the mode of copper delivery on the levels of these indices was usually not significantly different. As a result, the feeding of fructose as compared to starch produced lower levels of direct indicators of copper status when copper was supplied in the diet but not subcutaneously. It appears that ingestion of fructose as compared to starch increases the requirement for copper and that the mode of copper administration that circumvents the gastrointestinal tract attenuates the fructose-copper interaction. Thus, the fructose-copper interaction occurs either during intestinal digestion and absorption, hepatic uptake of copper via the portal blood or its hepatic utilization.

Administration, Oral↗
PubMed1989

Dietary fructose as compared to glucose and starch increases the calcium content of kidney of magnesium-deficient rats.

The effects of feeding diets containing fructose, glucose or starch with or without added magnesium (Mg) on tissue levels of calcium (Ca) in weanling rats were investigated. Rats were fed their respective diet for 4 wk and then fasted overnight. After decapitation, blood was immediately collected, and liver, kidney and heart were removed to determine their Mg and Ca content. Relative kidney and liver weights were greatest in the rats fed the fructose diet. Hypomagnesemia was observed in all animals fed a Mg-deficient diet regardless of carbohydrate source (1.71 vs. 2.27 mg Mg/dl plasma for Mg-deficient vs. Mg-adequate groups, respectively). Among Mg-deficient groups, starch-fed rats had the highest level of plasma Mg, while fructose-fed rats had the highest level of kidney Mg. Although plasma and liver Ca levels were not significantly different among the groups, Ca content of the kidney and heart was greatest in animals fed a Mg-deficient diet with fructose. This was especially evident in the Ca content of the kidney, which was 8- to 9-fold greater than that of all other experimental groups. The results of the present study demonstrate the presence of a synergistic interaction between fructose and Mg deficiency that increases Ca levels in certain soft tissues, especially the kidney.

Animals↗
PubMed1989

Computer-aided mapping of specific neuronal populations in the human brain.

Antibody-staining methods and computer-aided microscopic systems have been used to generate high-resolution panoramic maps of specific neuronal populations in the human brain (4,6,11). This report focuses on the problems inherent in attempting high-resolution mapping of large brain sections, and describes how they are solved by computer-aided mapping. Further applications of computers to the study of brain structure are considered.

Brain↗
PubMed1988

Effects of fructose feeding on blood parameters and blood pressure in impaired glucose-tolerant subjects.

The effects of fructose and glucose on selected blood parameters and blood pressure after 4 weeks of oral ingestion were investigated in nine impaired glucose-tolerant subjects (IGTS) and nine normal glucose-tolerant subjects (NGTS). The criteria for IGTS were (1) 1- or 2-hour postprandial glucose levels between 160 and 200 mg/dL (8.8 to 11.1 mmol/L); (2) compliance with the diet; and (3) no cardiac or renal complication. The mean increment in the area under the plasma glucose and insulin curves after a glucose load was significantly greater following glucose than following fructose ingestion in both IGTS and NGTS (p less than .05). Glycosylated hemoglobin was greater after glucose than after fructose ingestion in IGTS and NGTS (71 gm/L vs. 61 gm/L in IGTS; 61 gm/L vs. 59 gm/L in NGTS). Serum triglyceride level in IGTS fed glucose was 173 mg/dL (1.90 mmol/L), whereas in those fed fructose, it was 154 mg/dL (1.69 mmol/L). Serum cholesterol was also greater after glucose than after fructose ingestion in all subjects. However, the differences were not statistically significant. Urate, pyruvate, and lactate levels were significantly greater in IGTS fed glucose than in IGTS fed fructose. Systolic and diastolic pressures were lower in IGTS fed fructose than in IGTS fed glucose. The present study shows that a 4-week oral ingestion of moderate amounts of fructose appears to have more benefits than an equivalent glucose ingestion in both IGTS and NGTS. However, greater benefits were found in IGTS than in NGTS.

Blood Glucose↗
PubMed1985

Use of xanthan gum in dietary management of diabetes mellitus.

Xanthan gum (12 g/day) was fed in muffins during either the first or second half of a 12-wk period of muffin feeding, to free-living subjects. Nine subjects were diabetic, having moderately elevated serum glucose but managing without insulin or hypoglycemic drugs, and four were nondiabetic controls. Before the study and at the end of the xanthan and xanthan-free periods, bloods were taken before and 2 h after an oral glucose load. The feeding of xanthan gum lowered fasting and postload serum glucose and reduced fasting levels of total plasma cholesterol in diabetic subjects. Xanthan gum also tended to lower fasting and postload levels of gastrin and gastric inhibitory polypeptide (GIP) and fasting levels of total and VLDL triglyceride and cholesterol in VLDL and LDL fractions. Subjects reported a sense of fullness after consuming xanthan muffins but no severe digestive symptoms.

Adult↗
PubMed1985

Effects of fructose feeding on lipid parameters in obese and lean, diabetic and nondiabetic Zucker rats.

Effects of fructose feeding in moderate amounts on lipid metabolism of obese versus lean, and diabetic versus nondiabetic Zucker rats, were studied. Forty pairs of male lean and obese animals were assigned to two dietary groups, fructose and glucose. For each diet, one-half of lean and obese animals were injected with streptozotocin intraperitoneally (i.p.) to induce diabetes, and the other half were injected with buffer i.p. as a nondiabetic control group. After 9 wk of feeding, animals were fasted overnight, decapitated and exsanguinated. Organs were removed and weighed. Blood glucose, insulin, lactic acid, triglycerides, cholesterol, total liver lipids and urinary glucose were determined. Hyperphagia was observed in obese, non-diabetic and lean-diabetic animals. Streptozotocin injection drastically reduced insulin levels, and produced an impairment of growth, hyperglycemia, glucosuria, polydipsia and polyuria. Fructose feeding increased organ weights in kidney, liver and retroperitoneal adipose tissue, regardless of diabetic state. However, lactic acid levels were lower in fructose-fed groups than glucose-fed groups. In obese rats serum triglyceride levels were also lower in fructose-fed groups than in glucose-fed groups. Serum cholesterol was not affected by fructose feeding. The results indicated that fructose feeding did not produce hyperlipemia and lactic acidosis in the blood circulation in Zucker rats. However, fructose feeding did not improve glucose intolerance in diabetic animals, rather fructose feeding produced hyperinsulinemia in nondiabetic, obese animals.

Animals↗
PubMed1984

Food resources of low-income households in Southwest Mississippi.

Demographic data and food resources were studied for 1,400 households in seven counties in Southwest Mississippi. The results were compared for industrialized and non-industrialized counties and the urban areas. Household incomes and the educational levels of household heads were far below the national level. Hunger is still prevalent among those with the lowest incomes and the least education. Since most of the household heads with lower incomes either were unemployed or had unskilled jobs, the government was their main food resource. Welfare accounted for 25% and Food Stamps for 30%. The next important source was the school. Such critical conditions as lower income, limited education, unemployment, hunger, and need for government assistance were more prevalent in non-industrialized counties than in industrialized counties and the urban areas. The government assistance programs for food are necessary to prevent hunger, to maintain nutritional adequacy, and, consequently, to reduce medical bills. This is especially true for the poverty-level families, who need the federal food programs for daily survival.

Educational Status↗
PubMed1984

Comparison of dietary energy intakes and sources by race, sex, and age for adults in Mississippi.

Energy intake and sources and alcohol and caffeine consumption of 384 Mississippians older than 34 were studied by 24-hour recall. The data were compared by race, sex, and age. Whites consumed more energy and had more adequate energy intake than blacks. Energy intake was more adequate in women than in men. The mean protein intake for all groups, except black men, was in excess of the Recommended Dietary Allowance (RDA). Protein represented 12% of the calories consumed daily by whites and 14% by blacks. Both figures are slightly more than the RDA for this age group. Whites consumed 66 gm fat and blacks 56 gm, representing 33% of total energy for whites and 38% for blacks. The mean cholesterol consumption was 339 mg for blacks and 310 mg for whites. Men consumed slightly more cholesterol than women. Whites consumed 334 gm total carbohydrates and blacks 202 gm. Starch and sugar provided 59% of total energy for whites and 52% for blacks. Whites drank 4 times more alcohol than blacks, with alcohol representing 3% of energy for whites and 1% for blacks. Whites consumed 2.5 times more caffeine than blacks. Young individuals consumed more caffeine than older ones. This study clearly shows a significant racial difference in energy content and sources in the diet of adults in Mississippi.

Adult↗
PubMed1982

Effects of garlic on lipid metabolism in rats fed cholesterol or lard.

Effects of garlic on lipid metabolism were studied in three experiments using different aged male rats fed a diet containing 1% cholesterol or 15% lard. Lyophilized garlic was supplemented at 2% and 4% of the diet. Plasma glucose was not changed by dietary treatments. Rats fed cholesterol and lard diets increased plasma cholesterol and triglycerides compared to controls. Garlic decreased plasma cholesterol in cholesterol- and lard-fed rats, but decreased plasma triglycerides only in the lard-fed group. Garlic supplementation decreased very low density lipoprotein cholesterol and increased high density lipoprotein cholesterol. The liver weight, total liver lipid and cholesterol were increased in rats fed the cholesterol diet but a supplementation of garlic decreased those parameters by about 30%. Dietary cholesterol and lard decreased hepatic glucose-6-phosphate dehydrogenase and malic enzyme activities: the garlic supplementation further decreased these enzyme activities. Garlic feeding increased the excretion of the neutral steroids in both 16-week and 10-week-old rats and bile acids in only 16-week-old pair-fed rats. Garlic at the 2% level was similarly effective on lipid metabolism as at 4%. These results demonstrate that garlic increases the excretion of neutral and acidic steroids and exerts hypocholesterolemic effects in cholesterol-fed rats.

Adipose Tissue↗
PubMed1981

Clinical signs found in association with nutritional deficiencies as related to race, sex, and age for adults.

Clinical signs of various nutritional deficiencies for 429 adults were compared by race, age, and sex. The nutrients studied were vitamin A, riboflavin, vitamin C, vitamin D, and calcium. The prevalence of clinical signs of deficiency for all nutrients was much higher in blacks than in whites. Clinical lesions due to multiple nutrient deficiencies showed the same racial difference. Men had a higher prevalence of clinical signs for all nutrient deficiencies, except for vitamin A, that did the young. The racial and age differences in the nutritional status may be explained by the difference of educational and income levels. In comparison to the results reported from the Health and Nutrition Examination Survey (HANES), 1971 to 1974, the white subjects in this study had slightly higher prevalences of clinical signs than did those in HANES. Also, the prevalence of these clinical signs is much higher in the black subjects of the present study than in those of HANES.

Adult↗