Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An elevation in intracellular calcium ([Ca2+]i) in rats with chronic renal failure and elevated blood levels of PTH is associated with down-regulation of the mRNA of many proteins. Similarly, in phosphate depleted animals that have normal renal function and low blood levels of PTH, [Ca2+]i is elevated and the mRNA of PTH-PTHrP receptor is down-regulated. The effect of elevation in [Ca2+]i on molecular machinery of many proteins may represent a generalized phenomenon. Diabetes mellitus may also be associated with a rise in [Ca2+]i and therefore down-regulation of the mRNA of proteins may also occur. The present study examined the effect of streptozotocin-induced diabetes mellitus in rats on the [Ca2+]i of the renal proximal tubular cells and on their mRNAs of the PTH-PTHrP, V1a and AT1 receptors. The basal levels of [Ca2+]i of these cells increased significantly (P < 0.01) after one day of diabetes and remained elevated thereafter. There was a significant (r = 0.67, P < 0.01) direct correlation between the [Ca2+]i of the cells and blood levels of glucose up to 350 mg/dl, and the value of [Ca2+]i plateaued with higher concentrations of glucose. Three days of amlodipine therapy prevented and reversed the elevated levels of [Ca2+]i despite marked hyperglycemia. The mRNA of all three receptors in the kidney were down-regulated and this defect was prevented by amlodipine which normalized the [Ca2+]i of the cells. The results show that: (1) the hyperglycemia of IDDM in rats causes a significant elevation in the basal levels of [Ca2+]i of the renal proximal tubular cells and down-regulation of their mRNA of PTH-PTHrP, V1a and AT1 receptors; (2) normalization of the [Ca2+]i of these cells by treatment of the diabetic rats with amlodipine prevented the elevation of [Ca2+]i and the down-regulation of the mRNA of these receptors; (3) these effects occurred in the presence of normal renal function and normal blood of PTH and phosphorus.
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PMID:Elevation of [Ca2+]i of renal proximal tubular cells and down-regulation of mRNA of PTH-PTHrP, V1a and AT1 receptors in kidney of diabetic rats. 918 88

Intracellular calcium ([Ca2+]i) and phorbol ester binding were studied in intact platelets of young patients with insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes mellitus. Our objective was to evaluate disturbances in calcium regulation and signal transduction in platelets of diabetics. [Ca2+]i in platelets of the IDDM group (135 +/- 20 nmol/L) under basal conditions was significantly higher than that of the control group (81 +/- 8 nmol/L, P = .019), whereas at 60 seconds after stimulation with 0.1 National Institutes of Health (NIH) U/mL thrombin, [Ca2+]i in the NIDDM group (484 +/- 36 nmol/L) was significantly higher than that of the controls (347 +/- 22 nmol/L, P = .003) and IDDM group (360 +/- 45 nmol/L, P = .04), respectively. Phorbol 12,13-dibutyrate (PdBu) maximal binding capacity (Bmax) in the IDDM group was significantly lower than that in the control group either under basal conditions or after stimulation with thrombin (P = .0034 and P = .015, respectively). Bmax in the NIDDM group was significantly lower than that in the controls only after stimulation with thrombin (P = .047). The Kd for PdBu of the IDDM group was lower than that of the control group under basal conditions (P = .017). When analyzing the pooled data of all subjects, a significant correlation was observed between Bmax and Kd (under basal conditions, r = .544, P < .0001; after stimulation, r = .601, P < .0001). Our results support the idea that the increased affinity for PdBu may compensate for the decreased binding capacity. We interpret the data as indicating that the change in the binding of phorbol ester to protein kinase C (PKC) units may result in an altered PKC/calcium interaction in the pathogenesis of diabetes mellitus. Our study indicates that such metabolic derangements of [Ca2+]i have already been developing in young diabetic patients.
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PMID:Increased intracellular calcium and altered phorbol dibutyrate binding to intact platelets in young subjects with insulin-dependent and non-insulin-dependent diabetes mellitus. 925 80

Autonomic dysfunction is a recognized feature of the Lambert-Eaton myasthenic syndrome (LES). However, the characteristic pattern of dysautonomia has not been clearly documented and its pathophysiologic basis is not known. We therefore abstracted autonomic symptomatology and results of quantitative tests for salivation, and vasomotor, cardiovagal, and sudomotor reflexes from records of 30 LES patients. Dry mouth (77%) and impotence (45% of men) were the most common symptoms. Composite Autonomic Scoring Scale results were abnormal in 93% of patients, and autonomic failure was severe in 20%. The frequency of specific test abnormalities were the following: sudomotor function, 83%; cardiovagal reflexes, 75%; salivation, 44%; and adrenergic function, 37%. Although voltage-gated N-type calcium (Ca2+) channels are implicated in autonomic transmission, the low frequency of serum antibodies to N-type Ca2+ channels found in the patients of this study (31% positive) argues against a pathogenic role in mediating LES-related dysautonomia. In contrast, 93% of the patients were seropositive for P/Q-type Ca2+ channel antibodies. A subset of these antibodies is thought to impair neuromuscular transmission. Autoantibodies of thyrogastric or glutamic acid decarboxylase specificity (markers of predisposition to type 1 diabetes mellitus) were found in 45% of patients, and type 1 antineuronal nuclear antibody (or anti-Hu, a marker of autoimmune neuropathy associated with small-cell lung carcinoma) was found in 3%. No autoantibody correlated with autonomic dysfunction severity. Sensorimotor neuropathy was documented in five patients, and was not significantly associated with autonomic neuropathy. Autonomic failure was most severe in older subjects with cancer (p = 0.02, age by cancer interaction).
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PMID:Autonomic dysfunction in the Lambert-Eaton myasthenic syndrome: serologic and clinical correlates. 944 63

Clinical observations indicate that diabetes leads to micro- and macroangiopathy involving endothelial dysfunction. Because recent studies indicate an antiangiopathic effect of celiprolol, but not of metoprolol, in type 1 diabetes, we investigated the direct influence of exposure to high D-glucose concentrations on endothelial cells and the possible effects of both beta-blockers. Nine different chronic treatments were carried out on cultured porcine aortic endothelial cells: 1) 5 mmol/l D-glucose ("normoglycemic" cells), 2) 5 mmol/l D-glucose plus 15 mmol/l L-glucose (osmotic control), 3) 5 mmol/l D-glucose plus 0.5 micromol/l celiprolol, 4) 5 mmol/l D-glucose plus 0.05 micromol/l metoprolol, 5) 5 mmol/l D-glucose plus 0.5 micromol/l celiprolol plus 5 micromol/l propranolol, 6) 20 mmol/l D-glucose ("hyperglycemic" cells), 7) 20 mmol/l D-glucose plus 0.5 micromol/l celiprolol, 8) 20 mmol/l D-glucose plus 0.05 micromol/l metoprolol, and 9) 20 mmol/l D-glucose plus 0.5 micromol/l celiprolol plus 5 micromol/l propranolol. Using the Fura-2 technique, application of either 1 nmol/l bradykinin or 1 micromol/l ATP to the normoglycemic endothelial cells led to a significant increase in intracellular calcium, whereas the hyperglycemic cells showed significantly less reactivity to both agents. Exposure of endothelial cells to L-glucose did not show any difference to normoglycemic controls. Coadministration of 20 mmol/l glucose and celiprolol demonstrated that the alteration of the calcium signal induced by high D-glucose concentrations could be significantly antagonized with celiprolol. In contrast, coincubation with metoprolol failed to normalize the calcium signal. This effect of celiprolol was completely abolished in the presence of propranolol. In normoglycemic cells, none of the beta-blockers influenced the intracellular calcium response to bradykinin or ATP. These results indicate that chronic treatment with high D-glucose concentrations leads to an impairment of calcium signaling, which might be ameliorated by celiprolol.
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PMID:Influence of chronic exposure to high concentrations of D-glucose and long-term beta-blocker treatment on intracellular calcium concentrations of porcine aortic endothelial cells. 951 47

The prevalence of abnormally elevated albumin excretion rate (> 30 mg/24 h) is approximately 40% in insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetic patients. Diabetes has become the leading cause of end-stage renal failure in the US, Japan and Europe. Approximately 90% of the direct and indirect cost of caring for diabetic patients are spent on the complications of diabetes. Identification of patients at high risk of developing diabetic nephropathy is possible by screening for microalbuminuria (30-300 mg/24 h). Elevated urinary albumin excretion rate indicates a substantially increased mortality risk in diabetic patients. Randomised controlled trials in normotensive IDDM and NIDDM patients with persistent microalbuminuria indicate that ACE inhibitors diminish urinary albumin excretion rate, postpone it and may even prevent progression to clinical overt nephropathy. These findings indicate that screening and intervention programs are likely to have life saving effects and lead to considerable economic savings. Systemic blood pressure elevation to a hypertensive level is an early and frequent phenomenon in diabetic nephropathy. Furthermore, nocturnal blood pressure elevation (non-dippers) occurs more frequently in patients with nephropathy. Systemic blood pressure elevation and to a lesser degree albuminuria accelerate the progression of diabetic nephropathy. Effective blood pressure reduction with non-ACE-inhibitors and/or ACE-inhibitors frequently in combination with diuretics: (a) reduces albuminuria; (b) delays the progression of nephropathy; (c) postpones renal insufficiency; and (d) improves survival in IDDM and NIDDM patients with diabetic nephropathy. A specific renal protective effect of ACE-inhibitors in diabetic nephropathy has been demonstrated in IDDM patients with moderately reduced kidney function (s-creatinine > 133 mumol/l) while the data conflict with NIDDM patients. Antihypertensive treatment for diabetic nephropathy simultaneously extends life and saves money. Finally, reduced risk of fatal and non-fatal cardiovascular events have been demonstrated when diabetic patients with isolated systolic hypertension are treated with blood pressure lowering agents. Absolute risk reduction with active treatment compared to placebo was twice as great for the diabetic versus non-diabetic patients (101/1000 versus 51/1000 randomised participants at the 5-year follow-up), reflecting the higher risk of diabetic patients. In conclusion, early detection and aggressive treatment of arterial hypertension with ACE-inhibitors, long acting calcium antagonist and low dose diuretics as first line drugs are highly warranted in diabetic patients with or without diabetic renal disease.
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PMID:Is antihypertensive treatment the same for NIDDM and IDDM patients? 964 59

Erythrocyte Na/K ATPase activity is decreased in Type I diabetic patients; for Type II diabetic patients, literature data are controversial. Therefore, we have compared this enzymatic activity in 81 patients with Type I diabetes mellitus, 87 with Type II diabetes mellitus and 75 control subjects. Mean erythrocyte Na/K ATPase activity was lower in the Type I diabetic patients (285 +/- 8 nmol Pi x mg protein(-1) x h(-1)) than in the control subjects (395 +/- 9 nmol Pi x mg protein(-1) x h(-1)) whereas that of the Type II diabetic patients did not differ from that of control subjects. Sex, age, body mass index, and HbA1c levels did not influence erythrocyte Na/K ATPase activity. The 25 Type II diabetic patients treated with insulin, however, had lower Na/K ATPase activity than the 62 on oral treatment (264 +/- 18 vs 364 +/- 16 nmol Pi x mg protein(-1) x h(-1), p < 0.001) but similar to that of Type I diabetic patients. Among the Type II diabetic patients, stepwise regression analysis showed that fasting C-peptide level was the only factor independently correlated with Na/K ATPase activity; it explained 23% of its variance. In fact, in the insulin-treated patients, those with almost total endogenous insulin deficiency (C-peptide < 0.2 nmol x l(-1)) had the lower Na/K ATPase activity (181 +/- 21 vs 334 +/- 17 nmol Pi x mg protein(-1) x h(-1), p < 0.0001). The biological effects of treatment with C-peptide have recently led to the suggestion that this peptide could have a physiological role through the same signalling pathway as insulin, involving G-protein and calcium phosphatase and thus restoring Na/K ATPase activity. The relationship we describe between endogenous C-peptide and this activity is a strong argument for this physiological role.
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PMID:Erythrocyte Na/K ATPase activity and diabetes: relationship with C-peptide level. 975 27

We evaluated polymorphonuclear membrane (PMN) fluidity in 32 subjects with type 1 diabetes mellitus, 38 subjects with type 2 diabetes mellitus and 38 normal control subjects, by marking intact and unstimulated PMN cells with the fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). We also evaluated PMN cytosolic Ca2+ content by marking intact and unstimulated PMN cells with the fluorescent probe Fura 2-AM. PMN membrane fluidity differentiated normal subjects from type 1 and 2 diabetic subjects. The PMN cytosolic Ca2+ concentration did not discriminate type 1 and 2 diabetic subjects from normal control subjects. No statistical correlation was found between PMN membrane fluidity and PMN cytosolic Ca2+ concentration in any of the groups of subjects, nor were significant correlations found between PMN membrane fluidity and cytosolic Ca2+ concentration in several plasma parameters (serum glucose, cholesterol and triglycerides). In conclusion, in type 1 and 2 diabetic patients we found a decrease in PMN membrane fluidity and this decrease, which was greater in type 2 diabetic patients, may be a marker of PMN dysfunction.
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PMID:Polymorphonuclear leukocyte membrane fluidity and cytosolic Ca2+ concentration in diabetes mellitus. 984 Apr 53

Present study analyses nephroprotective effect of various therapeutic interventions at different stages of kidney involvement in diabetes mellitus. A MEDLINE search of past 10 years data on various experimental studies, controlled clinical trials, meta-analysis and editorials pertaining to nephroprotection in diabetes mellitus was made. Effect of various therapeutic interventions such as metabolic glycaemic control, restricted protein diet and antihypertensive drugs (especially ACE inhibitors) has been analysed on the progression of different stages of kidney involvement in diabetes mellitus such as normoalbuminuria, microalbuminuria, diabetic nephropathy and end stage renal disease (ESRD). An attempt has been made to analyse differential long-term impact of various therapeutic interventions in relation to type of diabetes mellitus (i.e., IDDM and NIDDM) and associated hypertension. Progression of IDDM patients having microalbuminuria or diabetic nephropathy with or without hypertension has improved during the past decade largely because of adequate glycaemic control and effective antihypertensive treatment with conventional drugs e.g. beta-blockers and calcium antagonists, and more so due to the use of ACE inhibitors e.g. captopril, enalapril etc. Superiority of ACE inhibitor tends to decline from normotensive stage to the degree of rise in systemic blood pressure. However, data in NIDDM patients suffering from diabetic nephropathy is incomplete and inconclusive.
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PMID:Nephroprotection in diabetes mellitus. 1005 45

Insulin-dependent diabetes mellitus is characterized by the selective destruction of pancreatic beta-cells. Chronic treatment with cytokines induced a low voltage-activated (LVA) Ca2+ current in mouse beta-cells. The concomitant increase in the basal cytoplasmic free Ca2+ concentration ([Ca2+]i) was associated with DNA fragmentation and cell death. Antagonists of LVA Ca2+ channels prevented this elevation of basal [Ca2+]i and DNA fragmentation and reduced the percentage of cell death. Exposure to cytokines did not affect the profile of Ca2+ currents or basal [Ca2+]i in glucagon-secreting alpha-cells. An increased Ca2+ signal through LVA Ca2+ channels may thus be a key feature in cytokine-induced beta-cell destruction.
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PMID:A low voltage-activated Ca2+ current mediates cytokine-induced pancreatic beta-cell death. 1006 44

Disturbances in bone marrow vascularisation can be one of the causes of diabetic osteopathy. The aim of the study was to answers the question if microalbuminuria as a results of capillary injury can be a sign of bone mineralisation disorders in IDDM renal sufficient patients. We examined 60 IDDM patients (30 women without menstruation disturbances; 30 men; age 25-36 years old). All the observed subjects were divided into groups: I-30 normoalbuminuric patients (0-29 mg/24 h); II-30 microabuminuric patients (30-295 mg/24 h). Bone mineral density (BMD) of femoral neck, lumbar spine (L2-L4) and total body was measured by dual energy X-ray absorptiometry (DEXA, Lunar). The biochemical parameters of bone turnover were measured both in serum and urine as follows: osteocalcine, total hydroxyproline (HPR, HPR/Cr), total alkaline phosphatase (AP) with bone fraction, total calcium (Ca, Ca/Cr) and inorganic phosphor (P). Microalbuminuric patients presented more severe bone turnover disturbances, shown by differences in: BMD and Z-score for femoral neck (p < 0.05), serum HPR (p < 0.05), AP (p < 0.05), AP (p < 0.01) and its bone fraction (p < 0.05). We proved the presence of statistically significant correlation coefficients for albuminuria and some densytometric and biochemical bone parameeters. Our results suggest that microalbuminuria can indirectly indicate the dynamic of bone turnover derangement in IDDM course. They are present mostly in the femoral neck, which because of the vascularisation type is particularly susceptible to subalimentation in the diabetic microangiopathy course.
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PMID:[Microalbuminuria as a risk factor for diabetic osteopathy in patients with IDDM and renal sufficiency]. 1010 25


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