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Biomedical subjects

B R Boshell

Publications and source records attributed to B R Boshell.

At least 19 recordsLinked to original sources
PubMed1989

Glycemic responses in insulin-dependent diabetic patients: effect of food composition.

This study examined the hypothesis that the glucose component of food and not the total carbohydrate is the major determinant of the glycemic response in patients with insulin-dependent diabetes mellitus. Patients were given glucose alone, fructose alone, glucose + fructose, lactose, and glucose + fat + protein. Fructose given alone increased the blood glucose almost as much as a similar amount of glucose (78% of the glucose-alone area, p less than 0.05). However, the same amount of fructose given with glucose produced no greater glycemic response than did glucose alone (108%). Similarly, galactose contributed only slightly to the glycemic response when given as lactose (122%, p less than 0.01) whereas protein and fat had no additional glycemic effect (101%). To test the above hypothesis in natural foods, patients were fed an amount of bread (high glycemic index) or apple (low glycemic index) that contained 25 g glucose. Both challenges produced glycemic responses very similar to 25 g purified glucose.

Adult↗
PubMed1986

Insulin binding and glucose transport activity in cardiomyocytes of a diabetic rat.

We studied insulin binding and glucose transport in isolated adult cardiomyocytes from rats with 2-wk streptozotocin-induced diabetes. At 37 degrees C, cells from diabetic rats bound less 125I-insulin and exhibited lower rates of 3-O-methylglucose transport than cells from control rats. In contrast, the amount of 125I-insulin bound to myocytes at 4 degrees C was the same in both groups. Preincubation of cells from both groups with 10-10,000 ng/ml insulin significantly increased their basal rates of glucose transport by approximately 40%. However, the augmented rates in diabetics were still approximately 36% lower than the corresponding insulin-stimulated rates in the controls. When the glucose transport data were expressed as percent maximal insulin effect and plotted as a function of the amount of insulin bound, the curves obtained from both diabetic and nondiabetic controls were superimposable. These data demonstrate that 1) heart cells from diabetic rats bind less insulin than from control rats under conditions in which they exhibit impaired glucose transport rates, 2) there is no apparent difference in total receptor number between the two groups, but internalization of intact insulin appears to be diminished in diabetes, 3) coupling exists between insulin binding and glucose transport in both groups, and 4) these impaired processes are completely reversed by insulin treatment in vivo but not in vitro.

3-O-Methylglucose↗
PubMed1983

Altered sensitivity of chronic diabetic rat heart to calcium.

An alteration in calcium metabolism in cardiac muscle was observed in diabetic rats 3 mo after streptozotocin treatment. Depression of cardiac output and left ventricular pressure development were more sensitive to decreased extra-cellular calcium in hearts from diabetic than from control animals and occurred within the normal physiological range of freely ionized serum calcium. This decrease in calcium sensitivity was not present after 2 wk of diabetes. In vivo treatment with insulin for 1 mo completely reversed the effect. Addition of octanoate (0.3 mM) to the perfusate of isolated hearts completely reversed the defect, whereas epinephrine (25 nM) only partially reversed it. When the glucose concentration of the perfusate was decreased, the function of diabetic hearts declined and was further diminished at decreasing calcium levels. Hearts from normal rats were unaffected. These results suggest that there is a defect in calcium metabolism or flux in the chronic diabetic rat heart.

Acute Disease↗
PubMed1983

Hyperosmolarity and cardiac function in chronic diabetic rat heart.

Serum hyperosmolarity is commonly associated with the poorly controlled diabetic state. The current investigation revealed that increased perfusate osmolarity using either glucose or mannitol caused a gradual decline in the aortic output of hearts from both normal and diabetic rats. However, aortic output decreased less rapidly in hearts from diabetic rats. Decreasing the extracellular calcium concentration to a level resulting in one-third of the maximal aortic output elicited a greater and more prolonged increase in aortic output from the diabetic compared with the normal heart when perfusate osmolarity was progressively increased. The coronary conductance of diabetic rat hearts improved when hyperosmolar solutions of either mannitol or glucose were utilized, irrespective of the external calcium ion concentration. In normal hearts, the coronary conductance tended to decline at higher perfusate osmolarities. The increased coronary conductance may play a role in the enhanced performance of diabetic hearts at higher levels of osmolarity. Hyperosmolar solutions influence the performance of hearts from chronic diabetic rats in a positive inotropic manner at low extracellular calcium concentrations (1 mM). These lower calcium levels are close to the normal physiological range of the freely ionized serum calcium. This effect is greater in hearts from diabetic animals than from normal animals and is similar to that obtained when perfusate calcium is increased. The results suggest that hyperosmolar solutions enhance calcium availability in the hearts of diabetic animals.

Adenosine↗
PubMed1982

Low risk of contrast media-induced acute renal failure in nonazotemic type 2 diabetes mellitus.

The risk of developing contrast media-induced acute renal failure was studied in 49 randomly selected nonazotemic type 2 adult diabetic patients subjected to IVU. There were 19 men and 30 women in the group whose mean age was 62 +/- 10 years (range, 38 to 82 years). In preparation for IVU, patients were neither dehydrated nor given a laxative. The IVU was performed in the morning, using sodium diatrizoate and meglumine diatrizoate. Serum creatinine levels were measured pre-IVU and on days 1, 3, and 6 after the IVU. A total of three patients (6%) had an elevation of serum creatinine greater than 25% above the baseline by post-IVU day 3. One patient developed oliguria (less than 400 ml/24 hr) that lasted 2 days. Creatinine clearances of the three patients showing contrast media toxicity were 74, 60, and 105 ml/min pre-IVU. In each of the three patients, a return to pre-IVU serum creatinine concentration was noted within 2 weeks. It is concluded that the risk of acute renal failure post-IVU is small in hydrated nonazotemic type 2 diabetic patients.

Acute Kidney Injury↗
PubMed1982

Mixed meal tolerance test and reactive hypoglycemia.

Twenty-six patients with symptoms suggestive of postprandial hypoglycemia were investigated by oral glucose tolerance test (OGTT). During the OGTT, symptomatic hypoglycemia occurred in 10 (38.5%). Nine of these 10 sugjects were given mixed meal tolerance tests (MMTT) and symptomatic hypoglycemia failed to occur in any case. During the OGTT the nadir glucose was significantly lower than that during MMTT (44.1 +/- 1.5 vs. 77.3 +/- 4.8 mg/dl +/- SEM, respectively; p less than 0.0005). Serum insulin during MMTT peaked significantly earlier than during OGTT (46.7 +/- 7.3 vs. 86.7 +/- 11.7 minutes (SEM, respectively; p less than 0.0125). The early secretion of insulin during MMTT may explain the lack of symptomatic hypoglycemia in these patients. We conclude that reactive hypoglycemia, when tested by a more natural stimulus (such as mixed meal) rather than by OGTT, is uncommon.

Adolescent↗
PubMed1981

Hemoglobin A1 in the diagnosis of chemical diabetes mellitus.

HbA1 was determined in 16 subjects with normal oral glucose tolerance test (OGTT), in 8 subjects with normal fasting plasma glucose (FPG) but with abnormal OGTT (chemical diabetes mellitus) and in 25 subjects with overt diabetes mellitus. The HbA1 values were 7.53 +/- 0.1%, 8.37 +/- 0.17% and 11.92 +/- 0.42% (+/- SEM), respectively. The HbA1 values of subjects with chemical diabetes mellitus were significantly higher (p less than 0.0025) than those of subjects with normal OGTT. Thus, the determination of HbA1 may prove to be useful to substantiate a significantly abnormal glucose tolerance (chemical diabetes mellitus).

Diabetes Mellitus↗
PubMed1979

Diabetes mellitus challenges for the future.

The future in diabetic research is both stimulating and exciting. Diagnostic subclassification as to specific etiology appears well underway and will provide a more scientific basis for therapeutic approaches. The importance of the histocompatibility complex and its many secrets are rapidly becoming apparent in the etiology of juvenile diabetes. Further studies in obesity and the neuroendocrines may solve adult-onset diabetes. Pancreatic transplantation and artificial devices may provide important therapeutic approaches. Further genetic explorations will, no doubt, provide clarity to the somewhat muddy picture of both etiology and complications. The challenges are here, let's hope that enough young scientists hear the call to provide the manpower to solve this major dilemma.

Aged↗
PubMed1979

Determination of insulin antibodies.

Insulin antibodies were determined as percentage binding of 125I-insulin in the sera of normal persons and of diabetic subjects treated and untreated with insulin. The effect of the dilution of the serum, circulating insulin and extraction of free and total insulin was evaluated. The determination of insulin antibodies in samples at a final dilution of 1:10 clearly discriminated between insulin-treated and untreated subjects. In insulin-treated subjects, the determination of insulin antibodies in samples at a final dilution of 1:100 gave false-negative results in 28 per cent. However, the determination of insulin antibodies at a final dilution of 1:100 discriminated between insulin-resistant and non-resistant diabetic subjects. Extraction of total insulin at pH 3.0 using 0.1 N HCl increased the percentage of 125I-insulin binding significantly. Extraction of free insulin by charcoal from the samples did not increase the binding of 125I-insulin. The injection of crystalline insulin 4 hours prior to withdrawing the samples did not decrease binding of 125I-insulin.

Diabetes Mellitus↗
PubMed1977

Hyperinsulinemic hypoglycemia: effect of epinephrine suppression.

The inhibitory effect of epinephrine on basal and tolbutamide-stimulated insulin release was studied in 5 patients with hyperinsulinemic hypoglycemia. Epinephrine inhibited both basal and tolbutamide-induced insulin release in patients with beta-cell adenoma and hyperplasia, but failed to inhibit insulin release in a patient with beta-cell carcinoma. The inhibition of basal insulin with epinephrine was maximum in patients with beta-cell hyperplasia. This differential inhibitory effect of epinephrine on insulin release may prove to be a useful screening test in the preoperative diagnosis of the nature of the lesion producing hyperinsulinemia.

Adenoma↗
PubMed1976

Free and total insulin levels in a patient with insulin-resistant diabetes mellitus and chronic lymphatic leukemia: effect of prednisone therapy.

An insulin-resistant diabetic patient who also has chronic lymphocytic leukemia and very high plasma levels of free and total insulin along with high levels of insulin antibodies is described. In response to prednisone therapy, his insulin requirement decreased, but the total and free insulin concentrations increased as insulin antibody measured as the maximal insulin-binding capacity of plasma remained unchanged. In insulin resistance, persistent hyperglycemia, in spite of high levels of immunoreactive free insulin, presumably reflects peripheral tissue unresponsiveness to insulin. The beneficial effect of prednisone treatment in this patient is discussed, and it is postulated to be the result of either increased availability of free insulin or an increased responsiveness of the tissues to insulin or both.

Adolescent↗
PubMed1976

Immunogenicity of "single component" port insulin.

Twelve diabetic subjects who were not previously treated with insulin were divided into two groups of six each. Group I was treated with single component pork insulin and Group II was treated with standard (USP) insulin for 5 to 10 months. Three out of six in Group I, and five in Group II, developed circulating insulin antibodies. Daily insulin requirement in the two groups were almost the same. Insulin antibody titer did not fall in three insulin-treated diabetic subjects when single component pork insulin was substituted for USP beef-pork insulin. This study shows that the single component insulin is antigenic in human subjects.

Aged↗
PubMed1976

Clinical evaluation of a new sulfonylurea in maturity onset diabetes - glipizide (K-4024).

Glipizide, a new low dose sulfonylurea, was evaluated for its efficacy and toxicity in a double-blind controlled study. Forty adult-onset diabetics were treated with either chlorpropamide or glipizide. In ten out of twenty patients "excellent" to "good" control of hyperglycemia was achieved with glipizide and two patients evidenced "fair" control. In nine out of eighteen patients "excellent" to "good" control was achieved with chlorpropamide. Eight of the sixteen patients who were primary or secondary failures on the two drugs responded to glipizide and phenformin combination with "excellent" to "good" control. No therapeutic advantage was found in giving more than 25 mg/day glipizide in ten patients. Toxicity was low and side effects were uncommon over a period of 26 months.

Adult↗