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Biomedical subjects

E Ryder

Publications and source records attributed to E Ryder.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Dyslipidemia and hyperinsulinemia in normoglycemic-obese relatives of patients with non-insulin dependent diabetes mellitus].

To determine the most frequent dyslipidemias among first-degree relatives of NIDDM patients, and its association with their glucose-tolerance status and hyperinsulinemia, we have started to examine members of NIDDM pedigrees, according to American Diabetes Association guidelines for nuclear family studies. In a large family with 2 NIDDM siblings in the 2nd generation, and 4 siblings with NIDDM in the 3rd generation, we have evaluated 14 first degree relatives and also 15 sex and aged matched healthy control subjects without family history of diabetes. The NIDDM relative group presented BMI = 31.8 +/- 3.9 kg/m2, SBP = 128 +/- 18.2 mmHg, DBP = 84 +/- 12.7 mmHg. Both relatives and controls were subjected to a 2h 75g OGTT for glucose and insulin determinations. Although none of NIDDM relatives has IGT, both Glycemic Area (GA) and Insulin Area (IA) were greater (p < 0.01) in the NIDDM relative group. The Insulin/Glucose ratio was also higher (p < 0.01) at 0 and 120 min of OGTT, this might be indirect evidence of Insulin- Resistance. Fasting serum lipids in the NIDDM relatives were TG = 148 +/- 24mg/dl, T-Chol = 244 +/- 10.7mg/dl, HDL-C = 34.2 +/- 2.5mg/dl; lipids in the control group were TG = 84.8 +/- 10.1mg/dl, T-Chol = 167 +/- 10.2mg/dl, HDL-C = 44.4 +/- 2.6mg/dl. Electrophoretic pattern showed type IIa (30.7%) and IIb (61.5%) hyperlipidemias in the NIDDM relatives. In this group, there was a positive and significant association between basal insulin and DBP (r = 0.67; p < 0.01), and between DBP and both TG (r = 0.74; p < 0.01)) and VLDL-C (r = 0.58; p < 0.05). It was also obtained a negative association between basal insulin and HDL-C (r = -0.89; p < 0.001). These data suggest that hyperinsulinemia in association with lipid abnormalities could appear early (before the development of Impaired Glucose Tolerance and Diabetes) in first degree relatives of NIDDM patients.

Adult↗
PubMed1994

Insulin and lipogenesis in rat adipocytes. II. Effect of high levels of insulin and glucose on lipid synthesis in isolated rat adipocytes.

Insulin resistant states are characterized by receptor and post-receptor defects in insulin action. When the insulin resistant state progresses, elevated levels of insulin are accompanied by increasing levels of glucose. In a previous paper we demonstrated that treatment of isolated adipocytes with high levels of insulin led to a decrease in insulin binding as well as a decrease in basal and insulin-stimulated lipid synthesis. The results of the present study establish that the addition of high concentrations of glucose in combination with a high level of insulin, does not modify the decrease in binding of insulin to its receptor. However, the decrease in lipid synthesis previously observed in the presence of high concentrations of insulin was completely overcome by the presence of high glucose.

Adipocytes↗
PubMed1994

Gerontology within district nurse education.

This paper describes a research study designed to explore approaches to integrating gerontological principles within district nurse education courses. Data were collected by a descriptive survey approach. The findings of the study indicated that various approaches were used to incorporate gerontological content within the curriculum. The district nurse lecturer emerged as the crucial link in ensuring subject material related to the specialism of district nursing, and the community practice teacher was significant in enabling students to relate gerontological theory to practice-based learning. The district nurse lecturer also emerged as supportive of the multi-disciplinary nature of gerontology by encouraging shared learning activities with a range of other community health care students. Against the background of major changes in community health care delivery, district nurses are identifying areas of expertise within their role as community health care nurses. One such area of expertise lies in the care of older people within the community, who form a high percentage of patients on the district nurse's caseload. In order to ensure that district nurses are effectively prepared to meet the specialist needs of older people, district nurse education courses must incorporate gerontological content within their programmes.

Aged↗
PubMed1994

[Glycemic index and insulin response to the ingestion of precooked corn flour in the form of "arepa" in healthy individuals].

With the purpose of exploring the glucose and insulin responses to a breakfast composed of a complex carbohydrate (CC) in the form of a "arepa" prepared with precooked corn flour, with or without the addition of protein and fat (CC + P + F), we studied 6 healthy volunteers, ages ranging from 26-50 years and body mass index of 24.5 +/- 1.32. Three tests were performed on each individual: 1) 75 g OGTT, 2) Ingestion of 75 g of CC ("arepa") and 3) Ingestion of 75 g of CC + 6.7 g protein (low fat cheese) and 4 g fat (margarine). Glycemic values (glucose - oxidase method) and insulinemia (radioimmunoassay) were determined at basal, 30, 60, 120, 180 and 240 min. Glucose (GA) and insulin (IA) areas, glycemic index (GI) and insulin/glucose ratio (I/G) were calculated. We found that the "arepa" has a high GI (71.5%) that it is increased, although not significatively to 140% with the addition of protein and fat. Total GA as well as IA obtained for CC and for CC + P + F were similar to OGTT, however the profiles of the glucose and insulin responses during CC and CC + P + F were less abrupt but more prolonged, resulting in a greater I/G ratio for OGTT in comparison with CC or CC + P + F during the initial steps. We conclude that GI of this corn bread ("arepa") is high in comparison to other complex carbohydrates and it is not altered by the addition of protein and fat. This is possibly due to glucose and insulin responses similar to that produced by OGTT.

Adult↗
PubMed1993

[Hyperinsulinism and lipid changes in the early stages of essential arterial hypertension].

The purpose of this study was to evaluate the presence of insulin-resistance in non-obese, non-diabetic patients with mild to moderate essential arterial hypertension of recent diagnosis and without prior pharmacological treatment and its relationship with the lipid alteration found in those patients. Twenty-one controls (9 M/12F) and twenty-nine patients (19 M/10 F) were studied. The control group presented mean age: 29 +/- 1.5 years, BMI: 23.9 +/- 0.46 Kg/m2, SBP: 112.6 +/- 2.9 mm Hg, DBP: 68.0 +/- 2.9 mm Hg. The patient group presented mean age: 35 +/- 1.4 years, BMI: 27.3 +/- 0.45 Kg/m2, SBP: 140 +/- 26 mm Hg, DBP: 95.1 +/- 1.4 mm Hg. The fasting levels of glucose, insulin and lipids were measured in each individual. Both controls and patients were subjected to an oral glucose tolerance test (OGTT) with determination of glucose and insulin at 30, 60, and 120 minutes. The patients had significantly (p < 0.05) increased plasma glucose at 0, 30, 60 and 120 min. and increased (p < 0.05) plasma insulin levels at O and 120 min compared to controls. The G/I ratio was significantly lower (p < 0.005) in the hypertensive group, at 0 h and 120 min. Abnormalities in fasting lipid profile were also observed in the patients including a significant increase in TG, Cholesterol, VLDL-C and LDL-C. These increases were especially evident in men and those with higher BMI. There was a positive and significant association between basal-insulin and TG, VLDL-C and DBP in hypertensive patients. We conclude that hyperinsulinemia is present in the majority of hypertensive patients and that hyperinsulinemia is associated with lipid abnormalities specially in men and the most individuals with higher BMI.

Adult↗
PubMed1993

[Effect of low doses of estrogens in menopausal women].

The effect of hormonal therapy in serum glucose, lipoproteins and the hemostatic system was studied in menopausal women, who were distributed in three groups: Group I (15 patients) received placebo in cycles of 21 days, followed by 7 days of rest; Group II (16 patients), received natural estrogens conjugated with progesterone in a sequential way, also in cycles of 21 days: Group III (16 patients), was treated with triphasic oral contraceptives in the same cyclical fashion. The patients completed 6, 12 or 18 cycles of the treatment. The results were as follows: The glucose levels were decreased by the 18th cycle in group II (P < 0.01). The HDL-cholesterol levels and the cholesterol/HDL cholesterol index were unchanged, however the basal levels of LDL-cholesterol in group III were high, but normal after 12 cycles of treatment. The coagulation factors did not changed significantly with the hormonal treatment, however fibrinogen was increased after 18 cycles under placebo. The von Willebrand factor and antithrombin III remained stable. Platelet aggregation with ADP increased after 12 cycles in group III (p < 0.05), and no changes were found with collagen. The above results suggest that the hormonal treatment in menopausal women, either with natural estrogens and progesterone or with triphasic oral contraceptives, has little effect in the lipidic concentrations of sera in these patients, however it can increase platelet activity, specially with prolonged treatment with semisynthetic estrogens.

Blood Coagulation Factors↗
PubMed1992

Insulin and lipogenesis in rat adipocytes. I. Effect of insulin incubation on lipid synthesis by isolated rat adipocytes.

To assess the effect of insulin on lipid synthesis in isolated rat adipocytes, cells were preincubated for 3 h with high concentrations (16.6 nM) of the hormone and lipogenesis measured through 14C-acetate incorporation into lipids, analyzing at the same time the activity of some lipogenic enzymes. It was found that insulin induced not only a decrease in the number of insulin receptors but a 30% loss in basal and insulin-stimulated acetate incorporation into total lipids as well as a decrease in the activities of enzymes related to the novo fatty acid synthesis pathway as malic enzyme and glucose-6-phosphate dehydrogenase.

Acetates↗
PubMed1992

Kinetics of phosphofructokinase from granulocytes isolated from patients with insulin resistance.

Phosphofructokinases from granulocytes isolated from insulin-resistant patients, mainly those from type II diabetics where the degree of insulin resistance was more pronounced, exhibit some changes in their kinetic behavior when assayed under allosteric conditions, characterized by an increased affinity for fructose-6-phosphate, being more resistant to ATP inhibition while it became more sensitive to citrate inhibitory effect. Those changes are suggestive of a isozymic modification to a more L-type enriched enzyme with a loss of the F-type component, probably present in the normal granulocyte.

Adenosine Triphosphate↗
PubMed1991

Kinetic studies of human polymorphonuclear leukocyte phosphofructokinase.

Phosphofructokinase from human polymorphonuclear leukocytes has low cooperativity and high affinity for its substrate, F-6-P. It is resistant to ATP inhibition at pH 8; however, at pH 7.1 it becomes sensitive to the effect of this compound. It is activated by F-1, 6-P2; it is not very sensitive to citrate inhibition and F-2, 6-P2 has no effect on its activity. With these kinetic characteristics we assume that perhaps the predominant L-type subunit is accompanied by an F-type component.

Citrates↗
PubMed1991

[Serum concentration of calcium and calcitonin in hyperthyroidism caused by Graves' disease].

Serum calcium and calcitonin were determined in 13 patients (12 women and 1 man), ages ranging from 30 to 40 years, with clinical diagnosis of hyperthyroidism due to Graves' Disease, confirmed by serum determinations of T3 and T4, with the purpose of establishing the relationship that these two substances may have in this pathology. The results obtained showed a decrease in seric calcium concentration in relation to a control group (10.02 +/-) 0.48 vs 11.49 +/- 0.28 mg/dl; p less than 0.005) and an increase in calcitonin concentration (193.6 +/- 8.62 vs 116.7 +/- 7.61 pg/ml; p less than 0.0001). We also found a significative negative association (r = -0.69; p less than 0.01) between these two compounds in the group of patients with hyperthyroidism, not being found in the control group.

Adult↗
PubMed1990

[Metabolic changes and most frequent complications in a group of type II diabetics. Their relation to the hyperglycemic state].

With the purpose of knowing which metabolic disorders and clinical complications are more frequently developed by diabetic patients, and to analyze the relationship between the hyperglycemia state and appearance of these complications, we studied a group of patients from a Metabolic Diseases Clinic in Maracaibo, Venezuela. Fifty-four Type II diabetics patients were evaluated by means of: physical examination, anthropometric measurements, biochemical control of glycemia, insulin and lipid pattern, as well as evaluation of the complications presented. The sample consisted of 33 men and 21 women, 75% of which had glycemic values over 140 mg/dl. Basal insulin values were significantly high (29.9 +/- 8.3 uU/ml in men and 30.9 +/- 10.1 uU/ml in women) in relation to a control group (14.5 +/- 2.4 uU/ml), concluding that our diabetics presented basal hyperinsulinemia and insulin resistance. The lipid pattern of the subjects studied showed hypertriglyceridemia (70%) and hypercholesterolemia (67%). A positive association between glycemia and triglycerides values was found in the total group. HDL-cholesterol values were significantly lower in relation to the control group, obtaining a negative correlation between HDL-cholesterol and triglycerides. The clinical complications observed in these diabetics were: non-specific visuals alterations, signs of arterial illness and sensorial disorders distributed in a similar percentage (63, 61 and 51%, respectively). When the independence test X2 was applied, we obtained association (p less than 0.05) between glycemia and the frequency of complications.

Adult↗
PubMed1989

[Metabolic changes associated with obesity in adults].

In order to find if the metabolic disorders more frequently found in our obese population were similar to the ones reported in the literature for other countries, a study was conducted in a group of 34 obese subjects (10 men and 24 women) whose only apparent alteration was a body mass index above 30 (mean value: 36.8 +/- 4.6) to obtain the relation between anthropometric measurements (Quetelet index, skinfold measures and waist/hip ratio) and plasma levels of nine biochemical parameters (including lipids, lipoproteins and glucose and insulin levels after an oral glucose load). The results revealed a tendency to the android distribution of fat in the female population, a significantly elevated triglyceride and total lipids levels and a decreased in HDL-cholesterol in both sexes. Hypercholesterolemia was present mainly in the male population. The most frequent dyslipidemia was Type IV (23%) followed by type IIb (15%). Practically none of the subjects had abnormal glycemic values after the glucose load, however the insulin levels were highly elevated in 80% of the patients, resulting in a great insulin/glucose ratios. Correlation analysis showed no association of the BMI with any biochemical parameter; only the insulin area was positively associated with anthropometric measures (mainly waist/hip ratio) and with the most altered biochemical parameter, the triglycerides. Variance analysis showed that only low HDL-cholesterol values were significantly different in patients presenting high blood pressure and familiar history of diabetes.

Adolescent↗
PubMed1988

Plasma and erythrocyte magnesium concentrations and correlations with maximum oxygen consumption in nine- to twelve-year-old competitive swimmers.

Twenty-two competitive swimmers (9 males, 13 females) were compared with 18 controls (11 males, 7 females) for body composition, intakes of selected nutrients, VO2max, hemoglobin, hematocrit and magnesium concentrations in plasma, erythrocytes and whole blood. Subjects ranged in age from 9.5 to 12.9 years. Male swimmers had 6.5% less body fat than did male controls (p less than 0.05) whereas there was no significant difference in body fat between female swimmers and controls. Energy, protein and magnesium intakes for swimmers and controls of the same gender were similar. VO2max was significantly higher in swimmers than in controls for both sexes. Magnesium concentrations in plasma, erythrocytes and whole blood were similar for swimmers and controls. However, concentrations of magnesium expressed as milligrams/deciliter in plasma were 8% higher in male swimmers than in female swimmers (p less than 0.05). There was a significant (p less than 0.05) positive correlation between plasma magnesium and VO2max in males, r = +0.42, but not in females.

Body Composition↗
PubMed1987

Enzymatic changes in polymorphonuclear cells isolated from type II diabetics.

The absolute values of several enzymes present in polymorphonuclear (PMN) cells isolated from subjects catalogued as Type II diabetics that never received insulin to control their hyperglycemia are reported. PMN from the blood of fasting diabetics and a control group were isolated by the dextran flotation technique. The enzymes were assayed in whole homogenates prepared by sonication of the cells. Serum glucose and immunoreactive insulin (IRI) were also determined from the same blood sample. We found a 40% decrease in the levels of phosphofructokinase (39.7 +/- 3.0 vs 66.1 +/- 6.3 mU/mg, P less than 0.001) and lactate dehydrogenase (350 +/- 22 vs 583 +/- 49 mU/mg, P less than 0.001) and a 25% decrease in malate dehydrogenase (250 +/- 29 vs 341 +/- 20 mU/mg, P less than 0.01). No differences in hexokinase (16.3 +/- 1.7 vs 18.2 +/- 1.7 mU/mg, P greater than 0.1) and glucose-6-phosphate dehydrogenase (66.6 +/- 2.5 vs 76.3 +/- 5.7 mU/mg, P greater than 0.05) were detected. These patients had normal or elevated levels of IRI (22.9 +/- 2.8 vs 14.5 +/- 2.4 microU/ml, P less than 0.05) concomitant with hyperglycemia (162.7 +/- 10.2 vs 78.0 +/- 1.6 mg/dl, P less than 0.001), revealing some degree of insulin resistance. It appears that glycolysis is affected not only at the phosphofructokinase step but beyond this point, glucose-6-phosphate dehydrogenase is not affected, and defective insulin action more than the lack of insulin might be responsible for the metabolic alteration.

Carbohydrate Metabolism↗