Search PubMed⌕ Search

Biomedical subjects

M Koch

Publications and source records attributed to M Koch.

At least 307 records · Page 17Linked to original sources
PubMed1991

[Does the care of diabetic patients with renal failure in the predialysis phase need improvement?].

The cardiovascular risk profile was assessed in all 208 diabetics accepted for dialysis in 28 German dialysis centres from 1985-1987 (104 men, 104 women, mean age 60 [22-82] years). 71 patients had type 1 and 128 type 2 diabetes, and 9 maturity onset diabetes of the young. Of 169 patients, 164 (97%) had hypertension (median systolic blood pressure at start of dialysis 200 [120-280] mm Hg). Only 74 patients (44%) were on continuing anti-hypertensive medication. Median serum cholesterol was 225 (66-424) mg/dl, LDL-cholesterol 158 (43-335) mg/dl and HDL-cholesterol 32 (10-67) mg/dl. In patients with a history of myocardial infarction (n = 26) the median cholesterol concentration was 269 (126-424) mg/dl, while in those with no history of myocardial infarction (n = 132) it was 221 (66-280) mg/dl (P less than 0.05). Only 5% of the patients had received lipid lowering therapy. Out of 175 patients, 65 (37%) had a history of smoking, and 25 (14%) were still smokers at the start of dialysis. There was a strong association between smoking history and amputations. Only 98 of 208 patients (47%) had had a specialist ophthalmological examination in the 12 months preceding the start of dialysis. Proliferative retinopathy was present in 33 out of 53 (62%) type 1 and 15 out of 98 (15%) type 2 diabetics. Out of 22 patients with unilateral or bilateral blindness, 2 (10%) had received no photocoagulation. - This investigation reveals a need for better medical care of diabetics with pre-end-stage renal failure.

Adult↗
PubMed1991

Ketamine enantiomers and acetylcholinesterase.

(-)-ketamine was found to be more potent than (+)-ketamine in all the studied reactions with acetylcholinesterase. In most cases the difference was small but for two rate constants the (-)-form was unique in having effects. Thus, the stereoselectivity of ketamine in this system is the opposite of most other systems studied.

Acetylcholinesterase↗
PubMed1991

[Transesophageal echocardiography: a new view of the heart].

Transoesophageal echocardiography is a simple technique which is now the object of a growing and well-deserved interest, due to the wealth of information it provides. This examination does not supersede the conventional transthoracic echocardiography, but it completes it by supplying more accurate data, especially in difficult clinical cases, such as mitral valve pathology, cardiac valve prostheses, intracardiac thrombosis, aortic dissection and septal abnormalities.

Echocardiography↗
PubMed1991

Parental behavior in the mouse: effects of lesions in the entorhinal/piriform cortex.

The effects of bilateral radiofrequency lesions in the region of the entorhinal and piriform cortex (ENT/PIR cortex) on pup-retrieving and ultrasound-elicited pup-searching behavior were investigated in ovariectomized estrogen-treated female mice, which were sensitized to pups by co-caring for a litter for 5 days together with the mother (FoEBex), as well as in primiparous lactating females (Flact). A further group of FoEBex were rendered anosmic by an intranasal treatment with zinc sulfate-solution before the sensitization period and tests for parental motivation. Both pup-retrieving and pup-searching behavior were disturbed to the same extent by ENT/PIR lesions and ZnSO4-induced anosmia in FoEBex. In Flact, however, pup-retrieving was not affected by the lesion, while ultrasound-recognition leading to pup-searching was disrupted. The present data suggest sensitization to pups as a case of olfactory learning and thus, the effects of the ENT/PIR lesions are regarded as anterograde olfactory amnesia. From the present data and results reported in the literature, it is suggested to differentiate between the neural substrates processing stimuli relevant for the appetitive component (pup-searching) of parental behavior (among others, the region of the entorhinal and piriform cortex), and the mechanisms regulating the consummatory component (pup-retrieving).

Animals↗
PubMed1991

Influence of affinity of antibodies upon their detection by liquid phase radiobinding assay and solid phase enzyme linked immunosorbent assay. Demonstration using monoclonal antibodies raised against rDNA human proinsulin.

Hybridomas producing proinsulin antibodies were cloned by limiting dilution of cell cultures obtained by fusion of splenocytes of immunized mice with immortal myeloma cells. Some proinsulin monoclonal antibodies crossreacted with labelled insulin but none did with labelled C-peptide indicating that the involved epitopes were at one of the insulin/C-peptide junctions or included in the insulin moiety. Hybridoma supernatants were assayed for IgG concentration by a solid phase assay and for ligand binding by a radiobinding assay and an enzyme linked immunosorbent assay. The half-life of immune complexes formed with radioligand was measured and, as expected, correlated with affinity as measured by the method of Scatchard. Antibody titres determined by enzyme linked immunosorbent assay did not correlate to those measured by radiobinding assay. IgG concentration correlated to enzyme linked immunosorbent assay titres but not to radiobinding assay titres. Finally, a significant correlation was found between radiobinding assay titre and the product of enzyme linked immunosorbent assay titre by the period of immune complexes. It is concluded that, except for very low affinity antibodies, enzyme linked immunosorbent assay is a capacity assay whereas radiobinding assay is influenced by both antibody concentration and affinity. The former assay is thus best suited to detecting low affinity antibodies whereas the latter is more efficient in the presence of low levels of high affinity antibodies.

Animals↗
PubMed1991

Epithelial synthesis of tenascin at tips of growing bronchi and graded accumulation in basement membrane and mesenchyme.

The extracellular matrix protein, tenascin, has been proposed as mediator in epithelial-mesenchymal interactions because of its characteristic distribution during embryogenesis. Here we compared the accumulation of tenascin and laminin in the early chicken lung bud. Laminin is deposited in the basement membrane, starting at the tips and increasing along the shafts of growing primary and secondary bronchi. In contrast, tenascin accumulation is highest in basement membranes and mesenchyme at sites where new bronchial branches are formed. By in situ hybridization, tenascin mRNA was found to be produced exclusively by the epithelium at sites of active growth of bronchial tubes.

Animals↗
PubMed1991

Iridoids and an Alkaloid from Oxera morieri1.

A novel monoterpene alkaloid, oxerine, has been isolated from the aerial parts of OXERA MORIERI. Its structure 7 has been elucidated on the basis of its spectral data and its sterochemistry established by its synthesis, using harpagide as starting material. Five iridoids and verbascoside have also been isolated from the plant material.

Journal Article↗
PubMed1991

[The accuracy of the imaging procedures (sonography, MRT, CT, angio-CT,nuclear medicine) in characterizing liver tumors].

In a prospective study, an attempt was made to determine the specificity of various imaging methods for defining tumours of the liver rather than their ability to demonstrate them. It was based on 130 patients with histologically confirmed lesions (33 haemangiomas, 17 FNH, 4 hepatocellular adenomas, 28 HCC, 36 adenocarcinoma metastases). The methods were MRT (130 cases), sonography (119), CT (122), dynamic arterial angio-CT (15), 99TC-EHIDA or blood pool scintigraphy (4 FNH, haemangiomas, HCC, 44 cases). MRT showed somewhat better results (accuracy 80%) than CT (73%) and angio-CT (73%) in demonstrating the type of lesion. The results of scintigraphy (53%) and sonography (69%) were rather worse. The range of accuracy for MRT, CT and sonography varied from 94% (haemangiomas with MRT) to 47% (FNH with sonography).

Biopsy↗
PubMed1991

A controlled study of 20 mg famotidine nocte vs. 150 mg ranitidine nocte for the prevention of duodenal ulcer relapse.

A 24-week, double-blind, randomized study at 13 centres compared the efficacy and safety of 20 mg famotidine nocte and 150 mg ranitidine h.s. for the prevention of duodenal ulcer recurrence. All participants had been successfully treated for an acute duodenal ulcer with 40 mg famotidine nocte. Patients were endoscoped at baseline and at 24 weeks, unless symptoms warranted earlier examination: of the 208 patients enrolled, 86 who received famotidine and 84 who received ranitidine met all protocol criteria and were considered evaluable. Intention to treat and per protocol analyses showed non-significant trends in favour of famotidine (P = 0.44 and 0.16, respectively). During the 24-week observation period, 16.3% of the famotidine group and 25% of the ranitidine group had an ulcer recurrence (95% CI of percentage difference -0.22 + 0.04). At 24 weeks, relief of day and night pain was reported by 81.2% and 91.8% of the famotidine-treated patients, respectively. The corresponding figures in the ranitidine group were 73.5% and 85.5%. No laboratory abnormalities related to the study-drugs were noted and only two drug related (possibly or probably) adverse experiences were reported, both in the famotidine group. The data from this study therefore, supports the conclusion that the efficacy of 20 mg famotidine nocte is comparable to that of ranitidine in preventing duodenal ulcer recurrence, with comparable tolerability for long-term therapy.

Adult↗
PubMed1991

Polymorphism of insulin antibodies in six patients with insulin-immune hypoglycaemic syndrome.

Insulin antibodies in six patients with immune hypoglycaemic syndrome were studied. The antibodies displayed a higher affinity for bovine insulin in two patients, were specific for human insulin in one patient and non-species specific in the other three patients. The predominant IgG subclass of the insulin antibodies was IgG4 in two patients, IgG3 in two and IgG1 in two. In one of these, the other three subclasses were also detectable. Insulin autoantibodies of four patients were homogeneous with regard to light chains (kappa), and those of the other two contained both kappa and gamma light chains. Analysis of insulin immune complex size by fast protein liquid chromatography was possible in three patients and demonstrated immune complexes with elution profile close to that of IgG, although not exactly superimposable to the one obtained with a mouse monoclonal insulin antibody. In two patients, avidity was too low to permit chromatography of the immune complexes, and, moreover, in these two cases insulin antibodies were of the IgG3 isotype and spontaneously formed aggregates independently of insulin binding. We conclude that insulin antibodies of the insulin immune syndrome are polymorphic but different from those generated by insulin therapy.

Adult↗
PubMed1991

Detection of astrovirus in pediatric stool samples by immunoassay and RNA probe.

Two new astrovirus assays, a rapid biotin-avidin enzyme immunoassay (EIA) and RNA probe hybridization, were developed and compared with an established astrovirus assay, an indirect EIA, and immune electron microscopy. Sensitivity and specificity were evaluated by using a screening panel of 22 astrovirus-positive and 305 astrovirus-negative fecal specimens. The biotin-avidin assay was equivalent in performance to the reference indirect assay, and both could detect about 10 ng of viral protein. Although the probe was more sensitive than either EIA and could detect higher dilutions of virus in tissue culture and stool specimens, it did not detect more astrovirus-positive fecal specimens. Of the 22 astrovirus-positive specimens detected by the EIAs, 20 were confirmed by immune electron microscopy with hyperimmune rabbit antiserum. To determine the usefulness of EIAs for large epidemiologic studies, EIAs were used to screen 1,289 stool specimens from three studies of children with and without diarrhea. Astrovirus was detected in 3.5% of specimens from children with diarrhea and 1.9% of specimens from those without diarrhea. Our results indicate that the biotin-avidin EIA is an efficient, sensitive, and specific method for routinely screening large numbers of fecal samples and that its application in epidemiologic studies may yield higher rates of astrovirus infection than have been found previously by other methods.

Avidin↗
PubMed1991

Comparison of oral contraceptive use in women with adenocarcinoma and squamous cell carcinoma of the uterine cervix.

The possible link between oral contraceptives (OCs) and cervical adenocarcinoma was tested by a case-case study of prior and current OC use in women with adenocarcinoma and squamous cell carcinoma. Cases were matched by age, year of diagnosis, and stage of the lesion, and personal, reproductive, and contraceptive data were obtained by mailed questionnaires. Except for smoking, which was significantly more prevalent in women with squamous cell carcinoma, the two groups were identical, with similar OC exposure. This study does not support the idea that OCs modulate the expression of cervical neoplasia in favor of adenocarcinoma.

Adenocarcinoma↗
PubMed1991

Nerve-dependent and -independent tenascin expression in the developing chick limb bud.

The extracellular matrix protein, tenascin, appears in a restricted pattern during organ morphogenesis. Tenascin accumulates along developing peripheral nerves as they leave the spinal cord and enter the limb mesenchyme (Wehrle and Chiquet, Development 110, 401-415, 1990). Here we found that most but not all tenascin deposited along growing nerves is of glial origin. By in situ hybridization with a tenascin cDNA probe, we determined the site of tenascin mRNA accumulation both in normal and nerve-free limbs. In normal wing buds, tenascin mRNA was first detected within the developing limb nerves. Vinculin-positive glial precursor cells, which comigrate with the axons, are the likely source of this tenascin message. In nerveless wing grafts, tenascin was first expressed in tendon primordia in the absence, and thus independently, from innervation. In contrast to normal limbs, grafted wing buds neither contained vinculin-positive glial precursor cells, nor expressed tenascin in regions proximal to tendon primordia. In normal wing buds, tenascin deposited by tendon primordia transiently parallels and surrounds certain developing nerves. After the major nerve pattern is established, tenascin mRNA disappears from nerves in the upper limb, but is expressed in perichondrium and tendons. We propose that glial tenascin facilitates the penetration of axons into the limb bud and is important for nerve fasciculation. In some places, early tendon primordia might help to guide the migration of axons and glial precursor cells towards their target.

Animals↗
PubMed1991

Superiority of radiobinding assay over ELISA for detection of IAAs in newly diagnosed type I diabetic children.

OBJECTIVE: Liquid- or solid-phase assays have been used for insulin autoantibody (IAA) determination, and the method of IAA measurement has not been standardized. RESEARCH DESIGN AND METHODS: IAAs were determined by radiobinding assay (RBA) and enzyme-linked immunosorbent assay (ELISA) in two large age-matched groups of nondiabetic and newly diagnosed insulin-dependent (type I) diabetic children. RESULTS: Positivity for IAA by RBA (greater than or equal to nondiabetic mean + 3SD) was 2 of 178 (1.1%) and 55 of 173 (32%) in nondiabetic and diabetic children, respectively. Prevalence of IAA by RBA was significantly higher in the youngest age-group (63% between 0-4 yr). Positivity for IAA by ELISA was 1 of 178 (0.6%) and 8 of 169 (4.7%) in nondiabetic and diabetic children, respectively. Concordance rates between both assays were 0 of 3 (0%) in control subjects and 5 of 58 (8.6%) in diabetic children. CONCLUSIONS: We conclude that RBA is more appropriate than ELISA for IAA detection at the onset of the disease. In addition, because available data suggest that IAAs detected by RBA only are high-affinity antibodies, it is tempting to speculate that IAAs reflect a mature immune reaction against endogenous insulin.

Adolescent↗
PubMed1991

Famotidine vs ranitidine h.s. in acute duodenal ulcer. A multicentre endoscopic trial.

A double-blind, randomized, active drug-controlled study was conducted in order to evaluate the efficacy and safety of famotidine vs ranitidine h.s. in promoting the healing of acute duodenal ulcers. Two hundred and eighty patients participated in the trial and received either famotidine 40mg h.s. or ranitidine, 300mg h.s. The two groups were not significantly different with regard to sex and risk factors such as alcohol consumption and family history of peptic ulcer disease, while in the famotidine group, there was a slightly higher number of patients who smoked. Endoscopy was performed at the end of 4 and 6 weeks in 248 patients (128 in the famotidine group and 120 in the ranitidine group). The healing rate in those receiving famotidine was 73.4% at the end of 4 weeks and increased to 93% at the end of 6 weeks, while in the ranitidine group, the rate was 75.8% and 92.5% respectively. Day and night pain markedly reduced in both groups and therapy was generally well tolerated.

Acute Disease↗
PubMed1991

[Which coronary investigation should be performed in patients with peripheral arterial diseases?].

In the context of peripheral vascular disease, the clinical history provides a means of evaluating coronary risk. The key features are: age, previous myocardial infarction especially when recent (under 6 months), anginal pain, smoking, diabetes and ventricular arrhythmias. Treadmill testing, often limited by symptoms of claudication, may reveal severe coronary ischemia and thereby the patients at very high risk. Upper limb exercise stress testing gives results similar to standard protocols of non-atherosclerotic patients when correctly performed and a reliable detection and evaluation of coronary lesions. Thallium dipyridamol myocardial scintigraphy is a very useful diagnostic method but requires special radionuclide facilities. This technique demonstrates the site of ischemia. Coronary angiography should be reserved for special cases because the risks of the procedure are always greater in patients with peripheral vascular disease.

Coronary Angiography↗