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Biomedical subjects

H Mehnert

Publications and source records attributed to H Mehnert.

At least 127 records · Page 7Linked to original sources

Platelet enzyme activities in diabetes mellitus in relation to endothelial damage.

Increased platelet reactivity has been suggested in the pathogenesis of both arteriosclerosis and diabetic microangiopathy. Therefore, platelet function and platelet enzyme activities were assessed in a large group of 357 diabetics (256 patients with IDDM, aged 16-49 and 101 patients with NIDDM, aged 50-78) and 163 matched controls, and related to photographically documented retinopathy (Rd) and to peripheral vascular disease (PVD) as well as to plasma levels of von Willebrand factor (VIII R:Ag) as an indicator of endothelial damage. Patients with IDDM had increased platelet aggregation (PA, expressed as microM ADP threshold concentration) before Rd was detectable in comparison to control subjects (P less than 0.01). PA was further increased in patients with advanced Rd (P less than 0.01), whereas 20 newly diagnosed diabetics with IDDM exhibited normal PA. Patients with minimal Rd did not differ from patients without Rd. Plasma beta-thromboglobulin (reflecting platelet consumption in vivo) was enhanced significantly in patients with Rd only (P less than 0.05), as was malondialdehyde (MDA) production of platelets (as a measure of platelet endoperoxide formation). Factor VIII-related antigen in plasma was already increased in patients without Rd (P less than 0.05), yet more so in patients with Rd (P less than 0.01). Prostacyclin-stimulated adenylate cyclase activity (ACA) of platelets (as an antiaggregatory enzyme system) was twice as high in diabetics with advanced Rd compared with patients without Rd and with controls (P less than 0.01). Significant correlations were found between PA and plasma F VIII R: Hg, MDA production, and ACA of platelets.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗

[Self-inflicted hypoglycaemia (three cases)].

A woman with normal metabolism but addictive tendency injected insulin, as was proven by the presence of insulin antibodies in serum. Another woman with a normal metabolism caused hypoglycaemia by taking sulphonylurea preparations, apparently from self-destructive motives. After all laboratory and other tests had at first pointed to organic hyperinsulinism, the diagnosis of self-inflicted hypoglycaemia was finally made by demonstrating the drug in plasma. A young diabetic who required insulin caused hypoglycaemia by injecting additional insulin. The complete absence of C-peptide and especially the strict supervision confirmed the diagnosis.

Adolescent↗

[ECG during rest as an indicator of vascular changes in diabetic patients].

EKG-findings of 186 non-selected diabetic outpatients and 52 control subjects of the age group of 50 to 79 years have been examined in relation to cardiovascular risk factors as well as to peripheral vascular disease (PVD) and carotid artery stenosis (CS). The Whitehall-Criteria of the Minnesota-Code were seen in diabetics (D) approximately twice as frequently as in non-diabetics (C): Minnesota-Code I: D 7% vs C 4%; IV 27% vs 13%; V 25% vs 15%; VII1 2% vs 0%. Beside higher levels of blood glucose and HbAI, diabetics differed from controls mainly by higher systolic blood pressure (p less than 0.001). Furthermore, they showed more signs of PVD and CS. Only in 27% of diabetics normal EKG-findings were seen. In comparison to age-adjusted diabetics with EKG-abnormalities, these patients showed signs of PVD and CS only to a minor degree and lower values were found for systolic (p less than 0,01) and diastolic (p less than 0.05) blood pressure, weight (p less than 0.05), serum triglycerides (p less than 0.02), and markedly higher values for HDL-cholesterol (p less than 0.01). These data show that in diabetics more frequently abnormal EKG-findings are seen and that a normal EKG in diabetics older than 50 years indicates low cardiovascular morbidity and a favorable risk factor profile.

Adult↗

[Patterns of allergic skin reactions during insulin treatment (author's transl)].

Intracutaneous testing was done in 85 patients with allergic reactions during insulin treatment. Six patients showed immediate reactions (type I), 76 showed allergic late reactions (type IV) and three showed combined allergy (type I/IV) to intracutaneous undiluted insulin. Whereas immediate and combined allergies were exclusively pure insulin allergies, several allergens were shown to be responsible in late reactions: nine patients had pure surfen allergy, 34 patients pure insulin allergy (against all insulins) and 11 pure bovine insulin allergy. A further 22 patients reacted to various allergens, 16 of them to surfen and all insulins, and 6 to surfen and bovine insulins. Estimation of the diameter of the erythema showed a significantly better skin tolerance of neutral than of acid insulins. Intracutaneous pig insulin led to less erythema than bovine insulin. Neutral pig insulins thus have the least antigenicity.

Animals↗

Prevalence and incidence of renal stone disease in a German population sample.

261 male and 242 female patients (age 15-65 years) were questioned about renal colics with passage of renal stones. The patients were questioned while undergoing a medical examination. The prevalence of renal stones varied between 1.1% (males 15-29 years) and 20.6% (males 50-65 years) with an average of 6.9%. The incidence of passage of a calculus was 0.62% percent of the population per year. These figures in a German population sample are in agreement with more recent data from other industrialized countries and point to the magnitude of renal stone disease as a public health problem.

Adolescent↗

Increased platelet adenylate cyclase activity ion diabetic patients with microangiography.

Platelet aggregation, beta-thromboglobulin levels and the platelet adenylate cyclase activity (expressed as increase of cAMP levels) were determined in blood samples from healthy control subjects and from diabetic patients with and without microangiopathy. Patients with diabetic microangiography showed significantly higher beta-thromboglobulin levels, an increased tendency to platelet aggregation, and higher cAMP levels in platelet-rich plasma after incubation with PGI2. The findings were interrupted by the assumption of an increased turn-over of platelets which might be a consequence of the microvascular disease.

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