Biomedical subjects

P Schmidt

Publications and source records attributed to P Schmidt.

At least 181 records · Page 10Linked to original sources

PubMed1992

Development of specific enzyme-linked immunosorbent antibody assay systems for the detection of chicken immunoglobulins G, M, and A using monoclonal antibodies.

The aim of the present study was the development of a sensitive and specific ELISA system for the quantitative and qualitative assay of chicken Ig Isotypes G, M, and A using monoclonal antibodies. Five hybridoma cell lines were developed that synthesized specific antibodies against chicken IgG and three lines each producing specific antibodies against IgM or IgA. Using an immunodiffusion test, the subclasses were determined. Isolation of monoclonal antibodies from ascites was carried out by way of affinity chromatography with protein G sepharose. The purity of the eluates were determined by both SDS-PAGE and HPLC. A Sandwich ELISA was found to be the most suitable technique for the assay. Specificity testing was carried out by Western blotting. An epitope analysis was also carried out. By variation of the single steps concerning incubation times, quantities, and concentrations of the substances to be applied, the whole procedure was optimized. Assay limits for individual Ig isotypes were determined. The limits were 20 ng/mL for IgG, 80 ng/mL for IgM, and 160 ng/mL for IgA.

Animals↗

PubMed1992

Efficacy, safety and tolerability of lovastatin and bezafibrate retard in patients with hypercholesterolemia.

Hyperlipidemia has turned out to be the most important risk factor for coronary heart disease and necessitates frequently lipid lowering long-term treatment. Therefore, efficacy and tolerability of hypolipemic drugs are of great interest. The objective of the present study was to compare the safety, tolerability and effect on plasma lipids of Lovastatin and Bezafibrate retard in patients with hypercholesterolemia. 99 patients with total cholesterol of > or = 250 mg/dl after a 4 week standard lipid-lowering diet were treated another 4 weeks with placebo and then randomized to 400 mg Bezafibrate retard or 20 to 80 mg Lovastatin given once a day for 12 weeks. Mean changes from baseline in total cholesterol, LDL cholesterol and triglycerides were significantly reduced, in HDL cholesterol increased in both treatment-groups (p < or = 0.01). The effects of Lovastatin on total cholesterol and LDL cholesterol were more pronounced than those of Bezafibrate retard (p < or = 0.01), while Bezafibrate had a larger effect on triglycerides (p < or = 0.05). The frequency of clinical adverse experiences was low and similar among treatment groups, the frequency of laboratory adverse experiences was higher in the Lovastatin group. One patient in the Bezafibrate group was withdrawn because of nausea, one patient in the Lovastatin group because of GGT elevation.

Adult↗

PubMed1992

[Alcohol intoxicated bicyclists in Düsseldorf 1986-1990].

Although traffic participation of bicycle riders is steadily increasing only few investigations concerning "riding while intoxicated" are available. This study examines the blood sample records of all blood samples submitted to the Duesseldorfer Institute of Forensic Medicine for blood alcohol analysis from 1986 to 1990 with respect to the participation of bicycle riders. As to the most important epidemiologic data: The proportion of samples from bicyclists increased from 2.6% in 1986 to 4.8% in 1990. Women account for 6.5%. 36.8% are younger than 30 years. Most bicycle riders were apprehended during the months of summer, on the days of the weekend and in the hours around midnight. 67.3% displayed a BAC above the legal limit for bicycle riders of 1.7 g/l. In comparison only 34.5% were judged highly drunken on medical examination. Regarding the group with a BAC above 2.5 g/l expected to be highly intoxicated 37.7% only appeared slightly or moderately impaired rising the suspicion of high alcohol tolerance.

Adult↗

PubMed1991

Urethral morphology and bladder instability.

In order to calculate the relationship between Spinning top urethra (STU) and bladder instability 160 voiding cystourethrogramms (VCU), performed in 102 girls, have been analysed retrospectively. 28 girls had STU, 16 of those had bladder instability as well (57%). We could not find the highly positive correlation between unstable bladder and STU as reported by other authors, although there was a statistically positive correlation between STU and bladder instability. However the confidence interval was very broad (38%-75%). We conclude that bladder instability may contribute to STU but cannot render the etiological explanation for all cases. STU seems to be a polyetiological sign. In our opinion only the combination of STU and bladder instability has a diagnostic impact, since several therapeutical concepts are available in cases of bladder instability. The finding of STU in the VCU should alert the examiner's attention to functional disorders of the lower urinary tract. If no instability can be found, STU should be considered to be a normal variant.

Child↗

PubMed1991

Neurite outgrowth on postmortem human brain cryostat sections: studies of non-Alzheimer's and Alzheimer's tissue.

An in vitro assay to test for regional differences in neurite growth-promoting and growth-inhibiting factors in tissue sections of CNS tissue has been adapted to the use of postmortem human brain tissue. Frozen sections of the temporal lobe from victims of Alzheimer's disease were used as substrates for sympathetic neurite outgrowth in tissue culture. Tissue sections from a non-Alzheimer's brain were used as a control. Both explanted chick sympathetic ganglia and dissociated chick sympathetic neurons were cultured for 3 to 5 days on tissue sections in the presence of exogenous nerve growth factor. The dichotomy between gray and white matter portions of the tissue sections in supporting neurite outgrowth that was previously reported for fresh frozen human brain tissue was also found to persist in postmortem tissue. In addition, the total neurite outgrowth from explanted sympathetic ganglia was found to be significantly less on postmortem sections when compared with previous results obtained from fresh frozen tissue samples of epileptic tissue. Dissociated neurons exhibited neurite outgrowth on Alzheimer's sections that showed preferential growth on blood vessel segments but no affinity for senile plaques. The results suggest that there is some decline in the neurite growth-promoting ability of cortical gray matter obtained from postmortem-derived brains when compared with fresh tissue and that senile plaques do not represent sites of neurite stimulation in this in vitro system.

Aged↗

PubMed1991

Chicken egg antibodies for prophylaxis and therapy of infectious intestinal diseases. V. In vivo studies on protective effects against Escherichia coli diarrhea in pigs.

A field study and a controlled infection trial showed the protective effect of egg yolk lyophilisate and whole egg lyophilisate against enterotoxic E. coli germs. The lyophilisates were gained from eggs of hens immunized against pilus antigen of porcine-enterotoxic E. coli. In a first field study using egg yolk antibodies, 92% of 299 diarrhea affected piglets were cured. In a further field study diarrhea affected piglets were cured after 3 days by application of egg yolk lyophilisate from immunized hens. Piglets treated only with egg yolk of not immunized hens showed no signs of recovery. The infection trial showed, that whole egg lyophilisate of immunized hens was as successful as a common antibiotic therapy in curing piglets, orally infected with 5 x 10(10) E. coli/feeding and animal. The present data show that chicken egg antibodies can be used for treatment of infectious diarrheal diseases in young animals. So far they represent a good alternative to the common used antibiotic therapy.

Animals↗

PubMed1991

Chicken egg antibodies for prophylaxis and therapy of infectious intestinal diseases. IV. In vitro studies on protective effects against adhesion of enterotoxogenic Escherichia coli to isolated enterocytes.

The pathogenic effect of enterotoxogenic E. coli is mainly to be found in the jejunum. Hence, an effective immunoprophylaxis should be focussed at this site. This can be done effectively by an oral application of specific antibodies. The present study describes the effectiveness of specific antibodies against E. coli. The antibodies were gained from the yolk of E. coli immunized hens and tested for their in vitro activity. The tests showed a significantly reduced adhesion of enterotoxogenic E. coli onto isolated pig enterocytes as long as the bacteria had been incubated with the specific yolk antibodies beforehand. For this reason, yolk immunoglobulins from immunized hens prove to be an effective and handy source of specific antibodies which offers good protection against adhesion of E. coli onto pig enterocytes.

Adhesins, Escherichia coli↗

PubMed1991

Doppler CO2-test in patients with vertebrobasilar ischemia.

The pathogenesis of vertebrobasilar ischemia (VBI) is still uncertain. Embolism and systemic hypotension have been discussed as possible causes. We evaluated the basilar arteries of 35 VBI-patients by transcranial Doppler-sonography at rest and under hypercapnic conditions and compared these findings with the basilar flow velocities in 10 healthy volunteers matched by age. We found no difference between the controls and the VBI-patients for the basilar flow velocities at rest. Under hypercapnia (end-tidal CO2-concentration 8.5%), the basilar blood flow velocities in the healthy controls increased by an average of 53.0% but only by 32.3% in the VBI-patients (p less than 0.005). The reduction of CO2 dependent vasomotor reactivity was observed in all VBI-patients, except in patients with infarction in the posterior cerebral artery area, possibly indicating a different pathogenic mechanism of stroke. The results in all other patients revealed no obvious correlation to the clinical course or angiographic or dopplersonographic findings. As CO2 dependent vasomotor reactivity and brain perfusion pressure dependent cerebral autoregulation have similar mechanisms, we conclude that systemic hypotension might play an important part in VBI.

Aged↗

PubMed1991

Gastrin-releasing peptide is a transmitter mediating porcine gallbladder contraction.

We studied the role of gastrin-releasing peptide (GRP) for porcine gallbladder motility. Immunohistochemistry visualized nerve fibers containing GRP-like immunoreactivity in muscularis. GRP concentration dependently stimulated contractions of muscularis strips (ED50, 2.9 nM). Neuromedin B was less potent (ED50, 0.1 microM), suggesting existence of GRP-preferring receptors. GRP-induced contractions were unaffected by muscarinic antagonism (1 microM atropine), axonal blockade (1 microM tetrodotoxin), cholecystokinin (CCK) receptor antagonism (10 microM MK-329), or substance P desensitization (1 microM), supporting the existence of myogenic GRP receptors. The bombesin (BN) analogue D-Phe6-BN-(6-13)propylamide (PA) stimulated contractions (ED50, 3.3 nM) with low efficacy (29% of that of GRP). D-Phe6-BN-(6-13)PA (1 microM) shifted GRP concentration-response curves one log to the right. D-Phe6-BN-(6-13)PA interacted specifically with GRP receptors; while abolishing responses to GRP (1 nM), responses to substance P (0.1 microM) and CCK-8 (1 nM) were unchanged. Electrical stimulation (10 Hz, 0.5 ms, 10 V) caused a rapid onset-slow offset, tetrodotoxin-sensitive excitation. Atropine reduced the amplitude to 58% and caused a delayed, slow onset-slow decline response. D-Phe6-BN-(6-13)PA reduced the amplitude to 59% and caused a very rapid onset-rapid decline response. Atropine plus D-Phe6-BN-(6-13)PA abolished responses to nerve stimulation. Nerve stimulation caused significant release of GRP-like immunoreactivity. Thus two neural inputs were defined: a cholinergic rapid onset-rapid offset excitation and a delayed, slow onset-slow offset excitation caused by release and subsequent binding of GRP to GRP-preferring receptors.

Animals↗

PubMed1991

[Hypopituitarism as the possible cause of prolonged gestation in cattle].

Multiple malformations were shown in a bovine fetus delivered at slaughter after a gestation period of 469 days. Hypoplasia of the adenohypophysis and a bilateral agenesis of the adrenal cortex suggest that the failure of initiation of parturition resulted from a fetal deficiency of ACTH and glucocorticoid hormones. ACTH, GH (growth hormone) and prolactin could not be demonstrated immunohistochemically within the adenohypophysis. However, TSH immunoreactive pituitary cells were demonstrable. Nevertheless, considering the extremely reduced size of the adenohypophysis a fetal deficiency of TSH is suspected. This view is supported by a bilateral hypoplasia of the thyroid gland. Additionally, the complex fetal endocrine dysfunction had led to a growth retardation of the fetus.

Abnormalities, Multiple↗

PubMed1991

[Malignant meningioma with lung metastases in a Boxer].

The rare case of a meningioma with pulmonary metastases in a dog is described. Clinically, the ten-year-old boxer bitch showed generalized seizures, strabismus and deficient proprioception. The post-mortem examination revealed a basically localized meningeal tumor, having the light- and electron-microscopic appearance of a malignant meningotheliomatous meningioma. Immunohistochemically, the tumor cells did not show any positive reaction with antibodies to GFAP, S-100 protein, NSE, vimentin, cytokeratin, desmin, and von Willebrand factor (factor VIII related antigen). Immunohistochemical examination of seven other canine meningiomas showed an identical pattern. The results and the relevant literature are discussed.

Animals↗

PubMed1991

[How frequently and with what symptoms are children presented to the pediatrician?].

Author prepared and processed 1500 computerised questionnaires in which primary-school children parents were asked about their knowledge of symptoms of childrendisease and habits: "how to consult with physicians". The questionnaire was divided 3 parts: in the first one general questions and some problem in connection with high-temperature, in the second one about symptoms, and in the third group pains were mentioned located in organs and different body-parts of children. The majority of parents accepted these questions and gave good answers and prepared some additional suggestions. Other group of parents having very bad habits relation to symptoms, and "how to consult with doctors and call duty-system". Author emphasized the very important role of data processing system for the further health organisation and health education.

Adolescent↗

PubMed1991

[Metastasizing glioma in a Boxer].

A metastasizing glioma in a 4-year-old boxer bitch is described. Clinical symptoms included ataxia, blindness, and increased cervical pain sensation. The tumor metastasized to an extraordinary extent via the cerebrospinal fluid. Tumor masses surrounded the whole spinal cord including the cauda equina. Histological examination revealed a variable morphology of the glioma. Immunohistochemical investigations showed some tumor cells reacting with antibodies specific to GFAP and S-100 protein. In contrast, NSE, 200 kd NF, vimentin, and desmin could not be demonstrated within tumor cells. The results are discussed in detail.

Animals↗

PubMed1990

[Craniocervical amyloid tumor with destructive spondyloarthropathy and myelocompression as a rare complication of long-term dialysis].

Dialysis-associated amyloidosis has become a frequent and sometimes disabling complication in long-term dialysis patients. The main protein implicated in amyloidosis is beta 2 microglobulin, which accumulates in patients with renal insufficiency. We report on a 47-year-old patient, who was on haemodialysis treatment for 17 years. After a period of 15 years on dialysis treatment he underwent surgery for a carpal tunnel syndrome. Two years later he developed destructive spondyloarthropathy of the cervical region and destruction of the occipital bone. He lost stability of his neck necessitating his remaining mainly in the lying position. Since the type of dialysis membrane may play an important role in the pathogenesis of dialysis-associated amyloidosis, a dialysator with a polysulfone membrane, which is assume to have a beneficial effect on the progression of amyloidosis, was established.

Amyloidosis↗

PubMed1990

[Diabetic nephropathy--recent therapeutic concepts].

Optimal metabolic control, strict antihypertensive therapy and a low-protein diet may reduce renal functional disorders such as hyperfiltration and microalbuminuria in the initial and latent phase of diabetic nephropathy and may retard progression of renal functional loss in the clinically-manifest proteinuric, azotaemic phase. Increasing clinical experience with renal replacement therapy in the end-stage renal failure of diabetic nephropathy led to a worldwide rise in the percentage of diabetic patients in dialysis centres. However, full rehabilitation is not achieved and retinopathy may progress to complete blindness. As a result of better rehabilitation and possible stabilisation of diabetic neuropathy and retinopathy after renal transplantation, in diabetic patients a kidney graft should be available early in the course of progressing renal failure.

Animals↗

PubMed1990

[Cervical hygroma in the calf as an absolute cause of dystocia. An unusual malformation possibly of hereditary genesis in Braunvieh x Brown-Swiss breeds].

Large cervical lymphocytes causing dystocia were observed in two Braunvieh x Brown-Swiss calves. The cysts were located on both sides of the neck and contained aqueous liquid. One of the animals was necropsied. The volumetric capacity of the cysts was 11 and 4 liters respectively. The hygroma are supposed to be the result of an interruption in the development of the lymphatic system resulting in the persistence of embryonic lymph sacs. Hypoplasia of the diaphragm, the pericardium and the mediastinum, and malformations of internal organs and the skeletal system were additional pathological findings. The lymphocysts and the other morphological anomalies, except those which may be explained as a consequence of cyst development are considered to be combined accidentally. Analysis of the pedigrees indicates that the lymphocysts may represent a hereditary malformation.

Abnormalities, Multiple↗

PubMed1990

Radioimmunoassay of 3 alpha-hydroxy-5 alpha-pregnan-20-one in rat and human plasma.

A radioimmunoassay for measuring 3 alpha-hydroxy-5 alpha-pregnan-20-one in plasma has been developed. Polyclonal antibodies were raised in rabbits against 3 alpha-hydroxy-20-oxo-5 alpha-pregnan-11 alpha-yl carboxymethyl ether coupled to bovine serum albumin. 3 alpha-Hydroxy-5 alpha-pregnan-20-one was purified from either extracts of plasma by high-performance liquid chromatography. These antibodies were then used for the radioimmunoassay of this centrally active progesterone metabolite in rat and human plasma. 3 alpha-Hydroxy-5 alpha-pregnan-20-one was detected in plasma from female rats on the day of estrus (2.0 to 9.3 ng/ml) and in the plasma of women during the luteal phase of the menstrual cycle at levels ranging from 0.25 to 2.5 ng/ml. The latter was highly correlated with plasma progesterone levels.

Animals↗

PubMed1990

Sudden natural death at the wheel--a particular problem of the elderly?

Thirty-nine autopsy cases of sudden natural death at the wheel were analysed with special respect to the questions if this is a peculiar problem of the elderly and if there are particular pathological features in the elderly. The ages ranged from 33 through 83 years and the median age was 56.4 years. 97% of the deaths were attributable to cardiovascular diseases, about 90% to coronary heart disease. People older than 60 years of age tended to exhibit severe chronical arterio-sclerotic changes of the coronary arteries, especially multiple calcified stenoses and myocardial scars, but there was a low percentage of recent thrombotic occlusion of a coronary artery.

Adult↗