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Biomedical subjects

T Haak

Publications and source records attributed to T Haak.

52 records · Page 3Linked to original sources
PubMed1994

Effect of 1-year treatment with nitrendipine versus enalapril on urinary albumin and alpha 1-microglobulin excretion in microalbuminuric patients with type 1 diabetes mellitus. A randomized, single-blind comparative study.

In order to compare the long-term effects of nitrendipine (CAS 39562-70-4) and enalapril (CAS 75847-73-3) on variables of glomerular and tubular function in type 1 diabetes mellitus, a single-blind, randomised comparative 1-year study was carried out in microalbuminuric patients (6 women, 14 men, age, 30-58 years, duration of diabetes, 3-41 years, HbA1 sigma 5.5-10%). 10 patients were treated with 20 mg/d nitrendipine, 10 patients were treated with 10 mg/d enalapril. On the average, urinary albumin excretion was decreased by 38 +/- 4% by nitrendipine (p < 0.01 vs. before treatment) and by 21 +/- 8% by enalapril (p < 0.05 vs. before treatment). The excretion of alpha 1-microglobulin decreased by 35 +/- 10% and by 39 +/- 9%, respectively (p < 0.05 vs. before treatment). Creatine clearance rose by 20 +/- 30% during nitrendipine treatment (p < 0.05 vs. before treatment) but was unchanged during enalapril treatment. Total kidney volume decreased by 23 +/- 4% (p < 0.01) and by 14 +/- 6% (p < 0.05), respectively. Blood pressure fell by 8 +/- 1% systolic and by 13 +/- 1% (diastolic) in nitrendipine-treated patients (both p < 0.01) and by 10 +/- 1% and 13 +/- 1% in enalapril-treated patients (both p < 0.01). Thus, nitrendipine long-term treatment of microalbuminuric type 1 diabetic appeared to be as effective as the treatment with enalapril in preventing or postponing the progression of diabetic nephropathy.

Adult↗
PubMed1993

[Significance of increased endothelin level for development of sequelae of diabetes mellitus].

In order to gain insight into the potential role of endothelin, a 21 amino acid peptide produced by endothelial cells, in the development of complications of diabetes mellitus, basal plasma endothelin levels were measured in 152 patients with diabetes mellitus (83 patients with type 1 diabetes mellitus, 69 patients with type 2 diabetes mellitus) and compared to those in 50 healthy controls. Blood was drawn at 8.00 a.m. under resting conditions and endothelin was determined after prior extraction by a sensitive radioimmunoassay. Endothelin levels were increased in patients with diabetes mellitus in comparison to controls (controls 0.9 +/- 0.1 pg/ml, type 1 diabetes mellitus 1.7 +/- 0.1, type-2-diabetes mellitus 2.0 +/- 0.1 pg/ml, p < 0.01 vs controls). 60% of patients with type 1 diabetes mellitus and elevated endothelin levels > 2.5 pg/ml (highest value measured in a control subject) had arterial hypertension with blood pressure > 140/90 mm Hg (p < 0.05 vs patients with normal endothelin levels). A reduced creatinine clearance (< 60 ml/min) was detected in 30% of patients with type 1 diabetes mellitus with elevated endothelin levels > 2.5 pg/ml, but only in 7% of patients with endothelin levels < 2.5 pg/ml (p < 0.05). In patients with type 1 diabetes mellitus and elevated endothelin levels diabetic retinopathy and peripheral neuropathy (p < 0.05) were more prevalent than in patients with normal endothelin values. 62% of patients with elevated endothelin levels had insufficient metabolic control (HbA1 concentrations above 10%). Positive correlations were found between endothelin and human atrial natriuretic peptide levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Human atrial natriuretic peptide in patients with type 1 diabetes mellitus: is it related to the development of diabetic nephropathy?

There is controversy as to whether increased plasma levels of human atrial natriuretic peptide (hANP) in patients with type 1 diabetes mellitus may contribute to the development of diabetic nephropathy. Therefore, we decided to conduct two studies to examine the relationship of hANP levels to urinary albumin excretion and blood pressure. In a cross-sectional study, 83 randomly selected type 1 diabetic patients were investigated. 19 of the patients had increased urinary albumin excretion. 45 healthy volunteers served as controls. In a longitudinal study, 19 type 1 diabetic patients were examined for one year at monthly intervals. An increased risk of eventually developing diabetic nephropathy was identified in 7 out of these patients by repeatedly revealing increased urinary albumin excretion. On the average, hANP levels were increased in type 1 diabetic patients in comparison to controls (P < 0.001). In both studies, hANP levels were positively related (P < 0.05) to mean arterial blood pressure. There was no correlation between hANP levels and metabolic control. hANP levels lay within normal range irrespective of normal or elevated urinary albumin excretion provided that mean arterial blood pressure was normal. In the longitudinal study, increased urinary albumin and alpha-1-microglobulin excretion preceded the increase in both hANP levels and mean arterial blood pressure. Although hANP levels were evidently not related to the disease mechanisms of early diabetic nephropathy, it is tempting to speculate that hANP may contribute to the vicious circle connecting diabetic kidney disease to hypertension once that its levels are increased by elevated blood pressure.

Adolescent↗
PubMed1992

[Iatrogenic origin of pleural effusion. A rare complication of the central venous catheter].

CASE REPORT: A 47-year-old woman with unremarkable plain chest X-rays in whom the Seldinger technique was employed to place a central venous line via the jugular vein, a catheter-related pleural effusion developed. CONCLUSIONS: This case points up the need to exercise care when placing a central venous line, and suggests the need to use contrast medium for the radiological follow-up examination.

Acute Disease↗
PubMed1992

Evidence for pulsatile secretion of human atrial natriuretic peptide in healthy subjects.

The secretion pattern of human atrial natriuretic peptide (hANP) was investigated in 8 healthy male volunteers. Blood was drawn in 2 minute intervals for 90 minutes and in a second study in 4 minute intervals for 180 minutes. Base-line hANP plasma levels varied in a pulsatile secretion pattern of regular pulses every 9 +/- 1 minutes. Additionally long-term oscillations of 34 +/- 4 minutes were found. These data suggest that under basal conditions hANP varies in a pulsatile fashion.

Adult↗
PubMed1992

Increased plasma levels of endothelin in diabetic patients with hypertension.

In order to gain insight into the potential role of endothelin, a 21 amino acid peptide produced by endothelial cells, in the development of complications of diabetes mellitus, basal plasma endothelin levels were measured in 152 patients with diabetes mellitus (83 patients with type 1 diabetes mellitus, 69 patients with type 2 diabetes mellitus) and compared to those in 50 healthy controls. Blood was drawn at 8:00 AM under resting conditions and endothelin was measured after prior extraction by a sensitive radioimmunoassay specific for both endothelin 1 and 2. Endothelin levels were increased in patients with diabetes mellitus in comparison to controls. In type 1 diabetes mellitus a positive correlation between endothelin levels and age was found. We found that 60% of patients with type 1 diabetes mellitus and elevated endothelin levels higher than 2.5 pg/mL (highest value in a control person) had had diabetes for more than 20 years (P less than .05 v patients with normal endothelin levels). In type 2 diabetes mellitus the relation between elevated endothelin levels and diabetes duration was reversed. Glycosylated hemoglobin (HbA1) concentrations above 10% of total hemoglobin were measured in 62% of the patients. Arterial hypertension was present in 60% of the patients with type 1 diabetes mellitus and increased endothelin levels greater than 2.5 pg/mL (both P less than .05 v patients with normal endothelin levels).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[The influence of autonomic diabetic neuropathy and human atrial natriuretic peptide on adrenal gland function in postural changes].

To investigate the influence of postural changes on plasma renin activity (PRA), plasma levels of human atrial natriuretic peptide (hANP) and on aldosterone in diabetes mellitus and autonomic neuropathy, ten patients with diabetes mellitus and autonomic neuropathy and ten patients with diabetes mellitus but without autonomic neuropathy were studied. Ten healthy subjects served as controls. Patients and controls were in supine position for 60 minutes, then changed posture sequentially to sitting (90 minutes) and to upright position (15 minutes). In controls, PRA was increased upon sitting and in the upright position, while hANP was decreased. Patients with autonomic neuropathy differed from controls in impaired renin stimulation, whereas in patients without autonomic neuropathy PRA responses to postural changes were only slightly decreased. In both groups of patients, the normal hANP responsiveness to postural changes was lacking. There were no differences in aldosterone levels between patients and controls. In patients with high basal hANP levels due to elevated systolic blood pressure renin responses to postural changes were decreased in comparison to those patients with low basal hANP levels. Thus, in patients with diabetes mellitus increased hANP levels which are not decreased in response to upright standing may contribute to the development of hyporeninism and its sequelae.

Adult↗
PubMed1990

[The effect of atrial natriuretic peptide on glucose tolerance and insulin level].

In previous studies, a pharmacological dose of human atrial natriuretic peptide (hANP) was found to increase serum insulin without influencing C-peptide levels. To examine whether blood glucose and insulin response to an oral or i.v. glucose load are influenced by raising hANP levels into the pathophysiological range, eight healthy, normal-weighted, male volunteers were studied. According to a randomized, double-blind study design, an oral glucose tolerance test (ogtt, 75 g) or an i.v. glucose tolerance test (ivgtt, 0.5 g/kg b.w.) were carried out. Beginning 30 minutes before glucose administration infusions of hANP 0.3 micrograms/min) or placebo were given for 180 minutes (ogtt) or 120 minutes (ivgtt). During the hANP-infusions maximal hANP levels were 72 +/- 11 pg/ml (normal less than 25 pg/ml). Responses of blood glucose and C-peptide levels to the glucose load remained unaffected by hANP in both studies. However, hANP increased mean insulin responses (given as area under the curve) by 11.5% in ogtt and by 15.9% in ivgtt (both p less than 0.05). Thus, elevated hANP levels within the pathophysiological range, as observed in chronic heart failure or in hypertension, lead to an increase in serum insulin. Unchanged C-peptide levels demonstrate that hANP does not interfere with insulin secretion, but exclusively inhibits insulin degradation in liver and/or kidney. Further studies are required to elucidate whether these findings play a part in the pathomechanisms of insulin resistance in patients with elevated hANP levels, e.g. in chronic heart failure or hypertension.

3-Hydroxybutyric Acid↗
PubMed1990

In vivo evidence that human atrial natriuretic factor-(99-126) (hANF) stimulates parasympathetic activity in man.

In a double-blind study 8 healthy male subjects received 100 micrograms human atrial natriuretic facotr-(99-126) (hANF) and NaCl0.9% in random order on different days. Following hANF injection a significant increase in cardiac beat-to-beat variation was observed (4.65% vs 5.95%). This shows that in vivo human atrial natriuretic factor stimulates cardiac parasympathetic activity in man.

Adult↗
PubMed1988

Impaired renal responsiveness to human atrial natriuretic peptide (hANP) in normotensive patients with type 1 diabetes mellitus.

Potential impairment of the efficacy of human atrial natriuretic peptide (human ANF-(99-126), hANP), the most potent endogenous natriuretic agent in healthy subjects, was examined in eight male normotensive patients with uncomplicated type 1 diabetes mellitus (aged 22-37 years). After giving informed consent, patients and eight male control subjects (aged 22-28 years) received in a random double-blind study design i.v. bolus injections of 100 micrograms hANP (Bissendorf peptide) or placebo. At base-line, patients differed from controls in elevated creatinine clearance (P less than 0.05) and in mild postprandial hyperglycemia. Whereas the responses of urinary cyclic guanosine monophosphate, the second messenger of hANP, were found to be normal in patients, the diuretic and natriuretic effects of hANP were grossly impaired when compared to controls (P less than 0.01); hANP resulted in increased plasma protein concentrations only in controls (P less than 0.05 vs patients). In both groups, creatinine clearance remained uninfluenced by hANP. There were similar decreases in plasma renin activity, aldosterone, levels, and blood pressure (systolic more than diastolic) in both groups (P less than 0.05 vs placebo). Heart rate and blood glucose remained unchanged. Thus, there is evidence for a decreased responsiveness to hANP exclusively of renal fluid, sodium, and chloride excretion in uncomplicated type 1 diabetes mellitus. The mechanisms responsible for this phenomenon remain obscure, neither a down regulation at the hANP receptor sites nor an hANP-induced shift from intra- to extravascular fluid volume are likely to be involved in its probably diabetes-specific pathogenesis.

Adult↗
PubMed1988

Dopaminergic effects on kidney function and responsiveness of aldosterone, plasma renin activity, prolactin, catecholamines, and blood pressure to stimulation in patients with prolactinoma. Comparison of the efficacy of pergolide and bromocriptine therapy.

8 beta-[(Methylthio)methyl]-6-propylergoline (pergolide) is a new, potent, long-acting dopaminergic DA2 receptor agonist currently being investigated for therapeutic use in patients with hyperprolactinemia, acromegaly or Parkinsons's disease. Since the influence of bromocriptine, a well-established dopaminomimetic compound, on aldosterone responsiveness and plasma renin activity is still a matter of debate, the efficacies of both compounds on these parameters and on kidney function, blood pressure, catecholamine release and prolactin levels were compared in 16 patients with prolactinoma. Supine and furosemide (40 mg i.v.)-stimulated plasma renin activity and aldosterone levels were similarly decreased by bromocriptine (2.5-30 mg/d) and pergolide (50-500 micrograms/d). Suppression of blood pressure, inhibition of stimulated norepinephrine release, increase in creatinine clearance, and decrease in base-line prolactin levels were similarly pronounced during treatment with both compounds. Metoclopramide (10 mg i.v.)-induced stimulation of aldosterone and prolactin levels, however, were suppressed only by bromocriptine and not by pergolide. It remains to be studied whether this difference between bromocriptine and pergolide is due to a potential agonist effect of pergolide on dopaminergic DA1 receptors which are influenced by bromocriptine in an antagonistic manner, or whether pergolide can be more readily displaced from its receptors than bromocriptine.

Adult↗
PubMedDate not supplied

The impact of contralateral cooling on skin capillary blood cell velocity in patients with diabetes mellitus.

In healthy volunteers, cooling of the contralateral hand leads to a rapid decrease in the ipsilateral capillary perfusion via a nerval reflex arc. The aim of this study was to investigate whether this reflex arc after contralateral cooling might be altered in patients with diabetes mellitus with and without peripheral neuropathy. Therefore, 12 patients with diabetic neuropathy (4 IDDM, diabetes duration 17.2 +/- 2.9 (SD) years, age 60.8 +/- 4.0 years, HbA1c 6.5 +/- 0.3%) and 12 patients with diabetes mellitus but without neuropathy (6 IDDM, diabetes duration 15.1 +/- 2.7 years, age 55.9 +/- 4.5 years, HbA1c 5.4 +/- 0.1%) were investigated by nailfold capillaroscopy. Twelve healthy volunteers (age 56.8 +/- 3.1 years, HbA1c 4.8 +/- 0.2%) served as controls. Contralateral skin capillary blood cell velocity was determined at rest and during the following 20 min after cooling of the hand (3 min at 15 degreesC). Blood pressure, heart rate and local skin temperature were examined regularly during the investigation. Resting capillary blood cell velocity did not differ between patients and controls. While contralateral cooling resulted in a decrease in capillary blood cell velocity (CBV) in controls (0.29 +/- 0.05 vs. 0.42 +/- 0.05 mm/s, p < 0.03), CBV remained unchanged or was delayed in patients. These results demonstrate that in diabetic patients nerval reflex arcs are impaired. A long-term follow-up in a larger number of patients is required to evaluate whether these findings might serve as a very early diagnostic tool for the diagnosis of developing diabetic neuropathy.

Blood Cells↗
PubMedDate not supplied

Pathologic study of an experimental canine arthritis induced with Complete Freund's Adjuvant.

OBJECTIVE: To describe the physiopathological features of an experimental monoarthritis in a canine model. METHODS: Pathological changes of the femorotibial joints, periarticular tissues and lymphoid organs were investigated by histology, immunohistochemistry, flow cytometry and cytokine bioassays after intra-articular administration of Complete Freund's Adjuvant in dogs. RESULTS: An edematous acute synovitis with considerable diapedesis of the neutrophilic granulocytes was observed during a primary response. This was followed by a clinical remission, although a multifocal subacute synovitis was noted with inflammatory infiltrates of mononuclear cells (macrophages > CD8 > CD4). Blood CD14 expression was upregulated and the percentage of CD8+ cells was significantly decreased. Two to four weeks post-induction, a decrease in functional impotency (secondary response) and a pyogranulomatous periarthritis with intramuscular extensions were noted. Focal cartilage erosion was due to adherent granulation tissue (CD4 > CD8 > macrophages). CONCLUSION: In this canine model, experimentally induced arthritis was mainly the result of a cell-mediated immune reaction towards a non-identified antigen.

Acute Disease↗