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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diabetes stimulates the functional activity of the intestinal brush border membrane with enhancement of both hydrolytic enzyme activity and membrane transport systems. To determine the mechanism of this effect, we studied the effects of streptozotocin diabetes on the metabolism of one membrane protein, sucrase-isomaltase, which increases its activity in diabetes. The protein was purified and an antiserum prepared. Sucrase-isomaltase from control and diabetic rats was immunologically identical as shown by Ouchterlony double-diffusion analysis of papain-solubilized mucosal proteins. The increase in sucrase enzyme activity in diabetic animals (31.0+/-1.4 U SEM 5 days after streptozotocin vs. 13.1+/-1.0 in controls) was the consequence of increased enzyme protein and not an alteration in catalytic efficiency as demonstrated by quantitative immunoprecipitin reactions. To account for increased sucrase-isomaltase protein in diabetes we studied papain-solubilized mucosal proteins labeled by injection of [(14)C]carbonate and [(14)C]leucine and analyzed incorporation into sucrase-isomaltase protein (anti-serum precipitable) and total protein (trichloroacetic acid precipitable). We found that diabetes did not affect the decay of labeled total protein, but prolonged the decay of labeled sucrase-isomaltase. t((1/2)) of sucrase-isomaltase was 4.4 h in control animals after [(14)C]carbonate injection and 8.8 and 10.2 h, respectively, 2 and 5 days after induction of streptozotocin diabetes. We obtained similar results in experiments with [(14)C]leucine with diabetes increasing t((1/2)) from 6 to 13.6 h. Diabetes did not appear to increase the rate of addition of sucrase-isomaltase to the brush border membrane, since it did not affect the 10- and 60-min incorporations of isotope into sucrase-isomaltase protein relative to incorporation into total protein and did not alter rate constants for synthesis calculated from the t((1/2)) and the change in enzyme mass over time.Thus, enhanced sucrase activity in the diabetic animal is the consequence of an increase in sucrase-isomaltase protein which develops because of a decrease in its rate of degradation.
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PMID:The intestinal brush border membrane in diabetes. Studies of sucrase-isomaltase metabolism in rats with streptozotocin diabetes. 14 62

Sixteen cases of lactic acidosis are reported: 7 phenformin treated diabetes, 5 cardiovascular diseases (2 myocardial infractions, 2 pulmonary embolisms, 1 heart failure). In 2 patients no etiology was found. Concomittant renal failure or liver diseases were found in respectively 9 and 4 cases. Patients presented the usual criteria of lactic acidosis: clinical, polypnea, severe hypotension (9/16), peripheral symptoms of shock (12/16), hypothermia (9/16), abdominal pain (9/16): biologically, acidosis (pH = 6,99 +/- 0,01, HCO3- = 5,9 +/- 1,5 mmol), hyperlactatemia (14,1 +/- 3,6 mmol/l) with hig lactate/pyruvate ratio (105 +/- 73), and anion gap (24,3 +/- 4,2 mmol/l). Sodium bicarbonate infusion was performed in all cases (2,5 to 42 mmol/kg). Few cases required volhemic expansion or furosemid induced diuresis. One patient was treated with extrarenal dialysis. 13 patients were alkalinised with less than 185% of estimated deficit measured from alkalin reserve: 12 died. 3 patients received 185% more than this deficit, associated with furosemid (1,8 to 12,5 mg/kg): only one patient died ten days after by casual disease, with lactatemia of 3,2 mmol/l. In spite of the small number of patients, these findings suggest that an early and massive alkalinisation, with large doses of furosemid, can improve the severe lactic acidosis prognosis.
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PMID:[Lactic acidosis and intensive care. 16 cases (author's transl)]. 23 77

Eighteen diabetic patients with lactic acidosis (L.A.) were analyzed for possible causal factors, metabolic changes, and efficacy of treatment. An antecedent phenformin therapy was performed in fifteen cases and was associated with renal insufficiency in ten cases and liver disease in eight cases. Tissular anoxia of primary hemodynamic or respiratory origin was absent in all cases. The severe metabolic acidosis (pH m.93 +/- 0,03; HCO3-= 6 +/- 1 MM; PaCO2 = 18 +/- 2 MM. Hg) and hyperlactatemia (14.2 +/- 0.3 mM) were associated with high lactate/pyruvate ration (70 +/- 22). High alanine levels (up to 4.6 mM) were measured in some of these patients. High beta-hydroxybutrate levels were sometimes measured (up to 7.6 mM), and substantial amounts of acetoacetate were also detected in twelve cases. Glucagon level was always increased (1,050 +/- 240 pg./ml.), and insulin/glucagon ratio was low. Cortisol (49 +/- 10 mug./100 ml.) and HGH (10.8 +/- 0.6 ng./ml.) were also elevated. Increased plasma levels of phenformin were measured in five L.A. diabetic subjects (50 +/- 5 mug./ml.) by comparison with other phenformin-treated diabetic subjects. The specificity of the assay was investigated, and phenformin metabolites were characterized by thin-layer chromatography. Por the treatment of L.A., adjunction of dialysis and furosemide improved the efficacy of early and massive sodium bicarbonate infusion. It is suggested that accumulation of phenformin via renal insufficiency plays a determinant role in causing L.A. through an impairment of lactate metabolism in the liver. An accelerated epuration of the drug may be helpful in therapy of L.A. Phenformin treatment should be avoided in case of renal and/or liver insufficiency.
Diabetes 1975 Sep
PMID:Phenformin-induced lactic acidosis in diabetic patients. 80 37

The diagnosis of diabetic ketoacidosis must be suspected and the initiation of treatment should be prompt to provide a satisfactory outcome in the treatment of diabetic ketoacidosis. Corrections of fluid and electrolyte deficiencies should be made slowly; rapid "push"injections or large infusions of sodium bicarbonate should avoided and ample amounts of potassium should be given early. Precautions should be taken so that blood glucose concentrations do not fall rapidly, and so that blood glucose levels of 250-300 mg/100 ml are maintained by the administration of 5-10% glucose solutions. Bicarbonate therapy is indicated only in severe acidosis (pH less than or equal to 7.1). Physicians who are trained in the care of diabetes mellitus should supervise the treatment. In our hospital the same staff physicians and fellows attend all patients with diabetes. In addition the efforts of our house staff and nurses have contributed significantly to the care of these patients.
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PMID:Pathogenesis, diagnosis and treatment of diabetic ketoacidosis. 81 99

The effect of exogenously administered somatostatin (SRIF) on meal-stimulated secretions of the exocrine pancreas was studied in dogs with chronic pancreatic fistulas. Dogs were fed 600 gm. of raw meat, and pacreatic output of water, bicarbonate, and protein was measured. Bicarbonate and protein secretions rose markedly postfeeding in all control animals. Four hundred micrograms or 100 mug. of SRIF infused for one hour together with a meal completely prevented the postfeeding rise in pancreatic secretions. SRIF (100 mug./hr.) infused one hour after a meal suppressed pancreatic secretions to basal levels within 30 minutes. Pancreatic secretions rose promptly after discontinuation of SRIF in all dogs. These data indicate (1) SRIF completely prevents pancreatic bicarbonate and enzyme responses when given together with a meal; (2) it completely suppresses already initiated pancreatic responses when given one hour after a meal; (3) 100 mug. of SRIF is as effective as 400 mug. in suppressing the postprandial rise in pancreatic secretions. We conclude that SRIF severely interferes with pancreatic secretions during normal alimentation and that this observation should be considered if SRIF is to be used as a therapeutic agent.
Diabetes 1977 Jan
PMID:Effect of somatostatin on meal-stimulated pancreatic exocrine secretions in dogs. 83 May 67

We describe a method for determining those urinary total phenolic compounds that are tyrosine analogs or metabolites, such as thyroxine and catecholamines. The urine sample, 4-aminoantipyrine in carbonate-bicarbonate buffer, and potassium ferricyanide solution are mixed and the quinoneimine dye that forms is measured at 500 nm. Some cases of hyperthyroidism, diabetes mellitus, nephrosis, obesity, hypertension, or catecholamine-producing tumor showed above-normal values, so that this determination seems useful as a screening test for these disorders.
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PMID:Determination of urinary total phenolic compounds with use of 4-aminoantipyrine: suggested screening test for hyperthyroidism and for catecholamine-producing tumor. 91 84

Under conditions closely approximating those in vivo (100 mM sodium carbonate pH 7.3 with 0.9% NaCl, 37 degrees C), antithrombin III (AT III) and the C1 inhibitor (C1-INH) are inactivated by methylglyoxal (MG) with pseudofirst-order kinetics and second-order rate constants of 25.2 and 7.8 M-1 min-1, respectively. A study of the functional status of neutrophils from patients with diabetes mellitus (DM) prompts an idea that under hyperglycemia in the diabetic organism the polymorphonuclear leukocytes (PML) endure 'arousal' that is identical or analogous to their activation. Indeed, nonstimulated PML from DM patients display (i) an almost sixfold higher luminol-dependent chemiluminescence and (ii) a double rate of oxygen uptake as compared with those from healthy donors, and (iii) are capable of MG formation in the presence of acetoacetate, which in vivo may be an additional source of this inactivator of AT III and C1-INH in diabetic patients. Conditions leading to ketosis or lactic acidosis are discussed, and a probable scenario is proposed for the organismic deterioration in DM.
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PMID:Antithrombin III, C1 inhibitor, methylglyoxal, and polymorphonuclear leukocytes in the development of vascular complications in diabetes mellitus. 144 May 21

Blood glucose, plasma sodium, bicarbonate (HCO3-), vasopressin, and hematocrit were monitored before and during treatment in patients with uncontrolled insulin-dependent diabetes mellitus (IDDM). These parameters were correlated with simultaneous serial cranial computed tomography readings of brain edema. Six of seven patients had positive computed tomography readings for brain edema on admission. Initial brain edema correlated directly with blood glucose (r = 0.79, P = 0.033) and inversely with HCO3- (r = -0.76, P = 0.047). At 6 h, brain edema still correlated with acidosis (HCO3-; r = -0.79, P = 0.033) but no longer with blood glucose. At that time, however, brain edema correlated with the rate of change in blood glucose (r = 0.915, P = 0.005). Results of interactive stepwise regression analysis suggest that the change in the calculated effective plasma osmolality plays a predominant role in the progression of brain edema during therapy (r = 0.995, P less than 0.001). Thus, although hyperglycemia and acidosis probably predispose to diabetic brain edema, osmotic factors may be major predictors of its evolution. No relationships were detected between brain edema and initiation of insulin therapy, plasma vasopressin, or changes in hematocrit. The factors responsible for initial brain edema and its progression, statistically identified in this study, require reassessment of common theories that attribute brain edema exclusively to therapy.
Diabetes 1992 May
PMID:Correlates of brain edema in uncontrolled IDDM. 156 33

The Na(+)-H+ exchanger is a ubiquitous transport system that is involved in the regulation of intracellular pH, cell growth and proliferation, cell volume regulation, and transepithelial absorption of Na+, Cl-, and HCO3-. Altered activity of the Na(+)-H+ exchanger has been implicated as a mechanism contributing to the development of high blood pressure in subgroups of patients with essential hypertension and in various animal models of hypertension. Many of these studies measured Na(+)-Li+ exchange rather than Na(+)-H+ exchange, hypothesizing that Na(+)-Li+ exchange represents a functional mode of the Na(+)-H+ exchanger. However, this is a controversial assumption. Several studies have also shown an association between erythrocyte Na(+)-Li(+)-exchange rate and predisposition to nephropathy in patients with insulin-dependent diabetes mellitus. The recent cDNA cloning of at least one isoform of the Na(+)-H+ exchanger will help clarify the cellular mechanisms of regulation of the exchanger and its possible role in pathophysiological states such as hypertension.
Diabetes Care 1991 Jun
PMID:Na(+)-H+ exchanger and its role in essential hypertension and diabetes mellitus. 165 Jun 93

Assessment of lactate metabolism is of particular interest during exercise and in disease states such as diabetes, shock, and absorptive abnormalities of short-chain fatty acids by the colon. We describe an analytical method that introduces radio-active tracers and high-performance liquid chromatography (HPLC) to simultaneously analyze concentrations and specific activities (SAs) of plasma lactate. The HPLC conditions included separation on a reversed-phase column (octadecylsilane) and an isocratic buffer (30% acetonitrile in water). [3H]Acetate served as an internal standard. Lactate and acetate were extracted from plasma samples with diethyl ether following a pH adjustment to less than 1.0 and back-extracted into a hydrophilic phase with sodium carbonate (2 mM, pH greater than 10.0). Lactate is detected in the ultraviolet range (242 and 320 nm) by derivatization with alpha-bromoacetophenone. Control plasma samples were studied after an overnight fast for precision and analytical recovery. Calibration curves were linear in the range 0.18-6.0 mM (r = 0.92). The precision was 3% and the analytical recovery was 87%. The detection limit of the method was 36 pmol. Determination of lactate metabolism was performed in a patient with chronic congestive heart failure who was administered primed-continuous L-[U-14C]lactate (10 microCi bolus and 0.3 microCi/min continuously) during a 60-min rest period. Mean arterial lactate concentration and SA were 1.69 +/- 0.2 mM and 253.8 +/- 22 dpm/mumol, respectively. Systemic lactate turnover was 25.65 mumol/kg per min. Lactic acid systemic turnover, organ uptake and release rates can be accurately determined by isocratic HPLC.
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PMID:Determination of plasma lactic acid concentration and specific activity using high-performance liquid chromatography. 178 35


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