Search PubMed⌕ Search

Biomedical subjects

M Weber

Publications and source records attributed to M Weber.

At least 685 records · Page 38Linked to original sources
PubMed1985

Rapidly progressive glomerulonephritis in IgA/IgG cryoglobulinemia.

Mixed IgA/IgG cryoglobulins were found in the serum of a 48-year-old man suffering from rapidly progressive glomerulonephritis (RPGN) with crescent formation. The type-II cryoglobulins were composed of monoclonal IgA1-kappa and polyclonal IgG, with the IgA possessing antibody activity against the IgG. The RPGN was of the immune complex type with granular deposits of IgA, IgG, and C3 on immunofluorescence microscopy and preponderant subendothelial deposits on electron microscopy. Occluding protein thrombi could be demonstrated in several glomerular capillary loops. Removal of the cryoglobulins from the patient's serum by plasmapheresis and immunosuppression was paralleled by a remarkable improvement in renal function with fall of serum creatinine values from 13.6 mg/dl (1,202.2 mumol/l) to 2.8 mg/dl (247.5 mumol/l), a resolution of the glomerular lesions, and clinical improvement as well. Our observations suggest that the crescentic glomerulonephritis may be due to an immune complex-like deposition of the cryoproteins. We conclude that crescentic glomerulonephritis in IgA/IgG cryoglobulinemia has to be considered as an autoimmune form of RPGN.

Biopsy↗
PubMed1985

[Urbach-Wiethe disease. Apropos of 2 cases].

The Urbach-Wiethe disease is a rare condition, where a hyaline substance of an unknown biochemical nature is accumulated in both teguments and mucous membranes. It has an autosomic and recessive genetic transmission. Cutaneous and mucous lesions (especially on the upper digestive tract) are described, insisting about the laryngeal location and the neurological troubles (with their main symptom: intracranial calcifications). The association of the disease with congenital indifference to pain is to be noted. Two particular cases are reported.

Adolescent↗
PubMed1985

In vitro differentiation of neuronal precursor cells from amphibian late gastrulae; morphological, immunocytochemical studies, biosynthesis, accumulation and uptake of neurotransmitters.

Neuronal differentiation has been studied in dissociated cell cultures from early neurulae of Pleurodeles waltl and Ambystoma mexicanum. Cocultures were prepared from the neural primordium and underlying chordamesoderm. NP and NF cultures were prepared from isolated neural plate and neural folds, respectively. Neuronal precursors in NP and NF cultures had distinctive aggregation properties already evident after 1-2 days in culture. After 10-15 days, mature neurones and synapses were observed by electron microscopy in the three culture types. The expression of neurofilament polypeptides and tetanus-toxin-binding sites was also present in these cultures. A small percentage of neurones contained cytochemically detectable catecholamine. Many neurones took up tritiated dopamine with a high affinity. Quantitative measurement of [3H]acetylcholine synthesis and storage from [3H]choline were negative at the early neurula stage and in 5 to 15-day-old NF cultures, and remained low in 5 to 15-day-old NP cultures. Acetylcholine production in cocultures increased linearly with time and was always much higher than in NP cultures. These results suggest that, at the early neurula stage, some neuronal precursors have acquired the capacity to express a high degree of morphological and biochemical differentiation even in the absence of further chordamesoderm influence. However, the chordamesodermal cells in the cultures increased acetylcholine synthesis.

Acetylcholine↗
PubMed1985

The role of extracellular signals in the differentiation of cholinergic neurons from the CNS and PNS in culture.

Rat skeletal muscle cells release in culture a macromolecule which stimulates by 25-100 fold the development of choline acetyltransferase (CAT) in cultures of new-born rat sympathetic neurons. This "cholinergic factor" impaired the development of three norepinephrine synthesizing enzymes and of acetylcholinesterase (AChE) in these cultures. The 16S form of AChE failed to develop in cultures grown with the factor, but amounted to 30-40% in 3-week old cultures grown in its absence. Using the development of CAT activity in sympathetic neuron cultures as an assay, the cholinergic factor has been partially purified in 6 steps, and its hydrodynamic parameters determined. The effects of this factor on sympathetic neurotransmitter choice were qualitatively reproduced by 1-10 mM Na butyrate. The cholinergic factor increased CAT activity and decreased AChE in neuron cultures from new-born rat nodose ganglia. The factor also stimulated CAT activity in rat embryo (E14) spinal cord cultures, but stimulated the development of AChE in these cultures.

Animals↗
PubMed1985

Neural induction: embryonic determination elicits full expression of specific neuronal traits.

In Pleurodeles waltl, the early neuronal differentiation of precursor cells from late gastrula stage has been studied by culture in vitro from either isolated neural plate (NP) or isolated neural fold (NF). The aim of this study was to delineate the information acquired by ectodermal target cells during neural induction. By culturing these cells in vitro either with or without the underlying chordamesoderm, we showed that in the absence of chordamesodermal influence such NP or NF cells exhibited a high degree of biochemical and morphological differentiation as revealed by the synthesis and the storage of neurotransmitters, the activity of specific enzymes, as well as by the expression of neuronal markers: specific changes in cell surface carbohydrates, tetanus toxin binding sites and neurofilament polypeptides. Remarkable changes in the cell adhesive properties were the first events observed in the different central (NP) and peripheral (NF) types. In cocultures the chordamesodermal cells exert a beneficial influence on this differentiation, specially increasing acetylcholine synthesis. There are some differences between central (NP) or peripheral (NF) neuroblast response to this further notochord or mesodermal influence.

Acetylcholine↗
PubMed1985

[Diagnostic approach in tumor patients with non-specific upper abdominal complaints].

The authors demonstrate on the basis of several observations of perigastric space-occupying growths in malignoma patients that x-ray examination of the stomach via mucosa and double-contrast imaging yields results of greatest diagnostic value in non-specific upper abdominal complaints. Supplementary diagnostic tools--but by no means competing methods--are often supplied by computed tomography and sonography. In case of extensive infiltration of the gastric wall, gastroscopy is indicated as an additional means to obtain confirmation by biopsy.

Abdominal Neoplasms↗
PubMed1985

[Chronic pyelonephritis as a false interpretation in the excretory urogram].

Chronic pyelonephritis, which is largely diagnosed via imaging procedures, is characterised by defined parenchymal scars that become manifest in the excretory urogram as contour recessions of the kidney and result in deformations of the calyces and papillae. The authors describe other renal diseases, dysplasias, variations from the standard, and artifacts resulting in similar signs on x-ray film, thus leading to the wrong diagnosis of chronic pyelonephritis. The essential differential diagnostic criteria are explained.

Chronic Disease↗
PubMed1985

[Prospective study of 64 cases of Kawasaki's disease].

We prospectively studied 64 children with Kawasaki disease. The well recognized signs were seen, but we also found hyperemia of the tympanic membrane in 27%, uveitis in 17%, syndrome of inappropriate secretion of anti-diuretic hormone in 9%, hydrops of the gallbladder in 8%, pulmonary infiltrations in 5% and one death. One patient presented with acute kidney failure, another one presented with stenosis of the renal artery, and 8 presented white blood cells (WBC) in the urinary sediment. Sedimentation was accelerated and there was an important decrease in hemoglobin blood level around the 5th day of illness. The WBC count rose around the 10th day; thereafter, all these results returned to normal while platelets counts rose. Albumin blood level was low, and all the following data were higher than normal: alpha-1-globulin, alpha-2-globulin, IgA, IgM, SGOT, SGPT, bilirubin and CRP. Viral studies were performed in 37 patients; 12 showed positive results.

Blood Cell Count↗
PubMed1984

[Angiomyolipoma of the kidneys in Bourneville-Pringle disease].

Three cases with renal angiomyolipoma in Bourneville's disease are reported. In two patients advanced renal insufficiency developed, one being treated by chronic intermittent hemodialysis. In the third patient rupture of angiomyolipoma with severe retroperitoneal bleeding occurred. In one patient, tumorous enlargement initially was diagnosed only in the right kidney and preceded angiomyolipoma of the left kidney for several years. In this patient nephrectomy was performed because malignancy was assumed before diagnosis of Bourneville's disease was established. Occasionally, histology may suggest sarcomatous changes. However, the absence of distant metastasis and the overall long survival of patients with renal angiomyolipoma in Bourneville's disease underline the benign character of the tumor. Treatment should be conservative because surgical intervention with loss of kidney parenchyma may enhance progression to end-stage renal failure.

Adult↗
PubMed1984

Improved aortocoronary bypass patency by low-dose aspirin (100 mg daily). Effects on platelet aggregation and thromboxane formation.

Prevention of aortocoronary bypass occlusion by aspirin (ASA, 1 X 100 mg per day) was studied in a prospective double-blind trial of 83 patients. 60 (72%) were randomly allocated to ASA or placebo starting 24 h after operation. 90% of grafts in the ASA group and 68% in the placebo group were patent at four months. At least one anastomosis was occluded in 62% of the patients on placebo and in 27% of those on aspirin. Ventricular arrhythmias increased after surgery in more patients on placebo (12/18) than in patients on ASA (5/17). Platelet thromboxane formation on collagen tested before operation was significantly higher in patients in whom bypass occlusion developed (occlusion: 40 +/- 19, no occlusion: 25 +/- 13 ng/ml). A 100 mg dose of ASA per day effectively blocked platelet thromboxane formation and thromboxane-supported aggregation on collagen and was safe in the postoperative phase. No side effects were reported throughout the trial. The reduced toxicity with full efficacy favours a low and infrequent dosage of aspirin.

Aspirin↗
PubMed1984

[Low-dose acetylsalicylic acid (100 mg/day) following aortocoronary bypass operation].

A prospective, randomized, double-blind, placebo-controlled trial was conducted to evaluate the efficacy of Acetylsalicylic Acid (ASS) (100 mg/d, starting 24 h after operation) on vein graft patency. Sixty of 88 patients having undergone surgery entered the study; in 24 of 31 patients in the placebo group and 22 of 29 patients in the ASS-group angiography was performed 4 months postoperatively. There were no significant differences between the groups with respect to age, number of diseased vessels or previous myocardial infarctions. Mean number of grafts per patient was 2,2 (placebo) and 1,8 (ASS) for proximal anastomoses (p less than 0.10) and 3.4 (placebo) and 2.6 (ASS) for distal anastomoses (p less than 0.05). Graft occlusion rate for proximal anastomoses was less in the ASS-group, 10% (4/40), as compared with placebo 32% (17/53) (p less than 0.05). Graft occlusion rate for distal anastomoses was also less in the ASS group, 19% (11/57) as compared to 35% (28/81) in the placebo group (p less than 0.10). All grafts were patent in 16/22 patients in the ASS group but only in 9/24 in the placebo group (p less than 0.05). On designation of patients without postoperative angiograms but cardiovascular events as well as those with at least one graft occluded as "failures", the incidence of the latter was 9/29 in the ASS group and 20/31 in the placebo group (p less than 0.05). Early postoperative bleeding was similar in both groups, no side effects of ASS were observed. In this trial with initiation of low - dose ASS therapy 24 h after operation, antiplatelet therapy reduced the graft occlusion rate significantly.

Aspirin↗
PubMed1984

Assessment of drug metabolism in hepatic disease: comparison of plasma kinetics of oral cyclobarbital and the intravenous aminopyrine breath test.

The exhalation of 14CO2 derived from an i.v. tracer dose of [dimethylamine-14-C]aminopyrine has been investigated in normal controls and patients. They subsequently ingested 200 mg cyclobarbital calcium in the evening and the decline in the plasma drug level over the following 2 days was measured by thin-layer chromatography. The peak specific activity of exhaled 14CO2 occurred 0.5-2 h after 14C-aminopyrine injection in the absence of liver disease and in non-cirrhotic liver disorders. It was delayed in certain patients with cirrhosis. Compared to 8 medically healthy subjects, 10 patients with acute viral hepatitis, 8 with cirrhosis and 10 with fatty liver exhibited a significantly increased half-life of 14CO2 exhalation. Normal mean values were found in 12 patients with non-cirrhotic alcoholic liver disease and in 14 patients with non-hepatic diseases. The cyclobarbital (CB) half-life was prolonged and the clearance reduced in patients with viral hepatitis, cirrhosis or alcoholic liver damage as compared to data from 17 control subjects. Due to a larger apparent volume of distribution, patients with fatty liver disease had an increased CB half-life, although its clearance was normal. A close negative correlation was detected between the clearance and the logarithm of the CB level measured 36 h after drug ingestion. The oral CB test evaluated from a single blood sample taken about 36 h after drug administration appears to be a useful indicator of human drug metabolising capacity. Discrimination between patients with and without disordered liver function was similar in the two drug elimination tests.

Adolescent↗
PubMed1984

Class-specific antibody responses in pigs following immunization and challenge with sporocysts of Sarcocystis miescheriana.

Sixteen pigs were each immunized by oral inoculation with 1000 sporocysts of Sarcocystis miescheriana at 8 weeks of age. Four equal groups were then challenged with 3 million sporocysts per animal at 40, 80, 120 or 160 days post-immunization (dpi). Host antibody responses were monitored using the enzyme-linked immunosorbent assay (ELISA) and the indirect fluorescent-antibody test (IFAT). When using class-specific ELISAs, dramatic increases in specific IgM-antibodies were observed at 21 dpi and increasing levels of IgG-antibodies were detected at 34 dpi. IgM-antibody titres dropped relatively quickly to insignificant levels, whereas IgG-antibody titres persisted at high levels until the end of the experiment. Following challenge, elevated levels of IgM-antibodies were detected, whereas IgG-antibody titres remained unchanged. The dynamics of the antibody titres detected by the IgG-IFAT closely corresponded to those detected by the IgG-ELISA. Despite the presence of specific antibodies at the time of challenge and the continued production of IgM-antibodies after challenge, the protective immunity decreased after 40 dpi and had disappeared by 120 dpi. Furthermore, none of the techniques used were suitable for the detection of specific antibodies during the early phase of acute sarcocystosis around 12 days after challenge.

Animals↗
PubMed1984

[Physical dependence on benzodiazepines in traumatology].

During the last years, there have been more and more observations of physical dependence on the benzodiazepines. This paper emphasizes the seriousness of this syndrome, its similarity with delirium tremens and its optimal treatment by high doses of benzodiazepines. This article shows also the misuse of drugs lowering the epileptogenic threshold and suggests in replacement the peranaesthesic administration of benzodiazepines or barbiturates. Finally the treatment should be started with a gradual and slow withdrawal so as to avoid undesirable neurological signs.

Adult↗