Search PubMed⌕ Search

Biomedical subjects

M Weber

Publications and source records attributed to M Weber.

At least 487 records · Page 27Linked to original sources

[Current status of treatment of pterygium].

After reviewing the various etio-pathogenic hypotheses for pterygium in which the discontinuity of the lacrymal film at the corneo-limbic junction appears to play an essential role, the authors discuss the current therapeutic choices. The value and place of lamellar keratoplasty overlapping the limbus are discussed.

Corneal Transplantation↗

Full activation of the rat oocyte by protein synthesis inhibition requires protein phosphatase activity.

The rat oocyte provides an interesting system in which to dissect the control mechanisms involved in the transition between a meiotic M phase and a mitotic interphase. In this study, we show that in rat oocytes activated parthenogenetically by puromycin, okadaic acid (a potent inhibitor of protein phosphatases 1 and 2A) induced an increase in histone H1 kinase activity suggesting that MPF was reactivated. However, the inhibition of phosphatases 1 and 2A shortly after second polar body extrusion did not allow the formation of a metaphase-like spindle, although microtubule polymerization was not inhibited. Instead, the chromatin remained condensed as a single mass and a large aster formed around it.

Animals↗

Laryngectomy: Grieving disfigurement and dysfunction.

When I (Weber) was three, my father had a total laryngectomy. His stoma did not bother me, and it was common to see him cough through his neck, though I never became used to the excessive secretions produced. My father mastered esophageal speech well, so communication was normal. No one in my family can remember what his voice was like before the operation. Knowing that people stared and whispered about my father, I warned new friends that my dad had a hole in his neck so he could breathe and that he might sound funny to them because he had no voice box. I did not want my friends to be frightened by a stoma that many people see as revolting.

Aged↗

Effects of sustained-release nicardipine on regression of left ventricular hypertrophy in systemic hypertension.

The effects of a sustained-release formulation of the calcium antagonist nicardipine on left ventricular (LV) mass, Doppler transmitral velocity profiles and plasma neurohumoral studies were analyzed in patients with mild to moderate systemic hypertension. A double-blind placebo control phase in 28 patients was carried out for 6 weeks with a subgroup of 13 subsequently entering an open-label long-term phase for 1 year. Nicardipine produced a significant decrease in systolic and diastolic pressure over the 6-week phase (158 +/- 15 to 142 +/- 9 mm Hg, and 100 +/- 5 to 89 +/- 9 mm Hg, respectively, both p less than 0.001). No significant differences in Doppler measures of mitral inflow or echocardiographic measures of LV function, wall thickness or mass were noted in the 6-week phase of the study. Although nicardipine increased both norepinephrine and renin values after the first dose, these levels had returned to baseline in most patients after 6 weeks. In addition, there was no evidence for stimulation of adrenomedullary activity because nicardipine had no effect on epinephrine or dopamine-B-hydroxylase levels at first dose or after 6 weeks. In the 13 patients treated for 1 year, systolic and diastolic pressure remained significantly decreased compared with pressure before therapy (135 +/- 9 vs 147 +/- 15 mm Hg, and 85 +/- 6 vs 97 +/- 9 mm Hg, both p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

[Spontaneous kidney rupture as an early complication of Wegener's granulomatosis].

A 51-year-old woman had been suffering from blood-stained purulent sinusitis and antibiotic-resistant bouts of fever for 4 months. She had microhematuria and serological evidence of inflammation (erythrocyte sedimentation rate [ESR] 92/135 mm, C-reactive protein 5.0 mg/dl). When she was admitted to hospital suspected of having postinfectious glomerulonephritis she complained of spontaneous colic-like pains in the left flank. Within one day the haemoglobin concentration fell from 10 to 6.5 g/dl. Ultrasound and computed tomography demonstrated a large space-occupying lesion around the left kidney. At operation this was found to be a rupture of the kidney with perirenal bleeding which was treated without removing the kidney. No biopsy was taken, but serological tests showed antineutrophil cytoplasmatic antibodies (cANCA), indicating Wegener's granulomatosis as the cause of the compensated renal insufficiency and spontaneous renal rupture. Under immunosuppressive treatment the inflammatory signs (ESR 18/44 mm), fever, chronic maxillary sinusitis, raised serum creatinine concentration and the ANCA titre all regressed, while proteinuria of about 4 g/24 h persisted. There was no recurrence during a follow-up period of 15 months. Serological signs of marked inflammatory activity, urinary sediments of nephritis and spontaneous retroperitoneal bleeding should suggest that, in addition to lupus erythematodes and panarteritis nodosa, Wegener's granulomatosis be included in the differential diagnosis.

Acute Disease↗

Importance of size and sulfation of heparin in release of basic fibroblast growth factor from the vascular endothelium and extracellular matrix.

We have characterized the importance of size, sulfation, and anticoagulant activity of heparin in release of basic fibroblast growth factor (bFGF) from the subendothelial extracellular matrix (ECM) and the luminal surface of the vascular endothelium. For this purpose, 125I-bFGF was first incubated with ECM and confluent endothelial cell cultures, or administered as a bolus into the blood of rats, the immobilized 125I-bFGF was then subjected to release by various chemically modified species of heparin and size-homogeneous oligosaccharides derived from depolymerized heparin. Both totally desulfated and N-desulfated heparin failed to release the ECM-bound bFGF. Likewise, substitution of N-sulfate groups of heparin and low molecular weight heparin (fragmin) by acetyl or hexanoyl residues resulted in an almost complete inhibition of bFGF release by these polysaccharides. The presence of O-sulfate groups in heparin increased but was not critical for release of ECM-bound bFGF. Similar structural requirements were identified for release of 125I-bFGF bound to low-affinity sites on the surface of vascular endothelial cells. Oligosaccharides derived from depolymerized heparin and containing as little as 8-10 sugar units were, on a weight basis, equivalent to whole heparin in their ability to release bFGF from ECM. Low-sulfate oligosaccharides were less effective releasers of bFGF as compared to medium- and high-sulfate fractions of the same size oligosaccharides. Heparin fractions with high and low affinity to antithrombin III exhibited a similar high bFGF-releasing activity despite a 200-fold difference in their anticoagulant activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

[Complications in the course of the Muckle-Wells syndrome].

A 35-year-old woman had since early childhood suffered from recurrent urticaria-like rash, intermittent fever, arthralgia and pancochlear inner-ear deafness. At the age of 17 years she also developed a steroid-resistant nephrotic syndrome, found to be due to renal amyloidosis (type AA). The triad of renal amyloidosis, inner-ear deafness and recurrent urticaria is characteristic of Muckle-Wells syndrome, which has a hereditary basis. Rapidly progressive renal failure necessitated long-term haemodialysis and two renal transplantations. The accompanying immunosuppressive treatment with corticosteroids, azathioprin and, later, cyclophosphamide brought about a remission of the joint and skin abnormalities. After removal of the first donor kidney and termination of immunosuppressive treatment the syndrome recurred with subacute growth of an amyloid goitre as well as amyloidosis of the optic nerve. A few weeks before death a malignant non-Hodgkin lymphoma of the stomach was demonstrated. It was presumably a complication of long-term immunosuppression and not of the Muckle-Wells syndrome. The patient died of the complications of combination chemotherapy. Necropsy revealed generalized amyloidosis.

Adult↗

Binding of fluorescein-labeled anaphylatoxin C5a to human peripheral blood, spleen, and bone marrow leukocytes.

The expression of C5a receptors (C5aR) on human leukocytes was evaluated by flow cytometry using fluorescein-labeled human C5a (C5a-F). Granulocytes and CD14+ mononuclear cells (MNL) but not CD3+, CD20+, CD16+, CD56+, or CD11b+ lymphocytes in peripheral blood and spleen bound C5a-F. C5a-F binding was saturable and inhibitable by anti-C5a monoclonal antibody (MoAb) C17/5 or unlabeled C5a. During hemodialysis, which led to the generation of C5a, only granulocytes and monocytes increased their expression of the adhesion molecule CD11b (CR3). In vitro, C5a induced an increase of CR3 and p 150/95 (CD11c/CR4) only on myeloid cells. However, treatment of leukocytes with phorbol 12-myristate 13 acetate increased CR3 and CR4 expression on both myeloid cells and a lymphocyte subpopulation. Stimulation of MNL in mixed lymphocyte cultures or by treatment with conditioned medium or with IFN-gamma did not induce binding sites for C5aR on lymphocytes and reduced the binding of C5a-F to monocytes. The expression of C5aR on low-density bone marrow cells was analyzed by setting appropriate gates during flow cytometry. Cells that bound C5a-F were found in all populations that contained granulocyte and monocyte precursors, but not in lymphocyte precursor populations. All C5aR+ bone marrow cells were CD34 and expressed high levels of CR3, which suggests a late appearance of C5aR during myeloid cell maturation. Our results indicate that C5aR is exclusively expressed on myeloid cells within the hematopoetic cell population.

Antibodies, Monoclonal↗

High concentrations of soluble tumor necrosis factor receptors in ascites.

Ascites and plasma concentrations of soluble tumor necrosis factor receptors p55 and p75 were measured in a prospective study in 34 patients (35 occasions of ascites) with hepatic (5 infected and 21 uninfected) and malignancy-related (9) ascites. All patients had high concentrations of both soluble tumor necrosis factor receptors in ascites and plasma; these were about 500 times higher than the corresponding tumor necrosis factor-alpha concentrations. Ascites levels of soluble tumor necrosis factor receptors p55 and soluble tumor necrosis factor receptors p75 were significantly elevated in patients with malignancy-related (p55: 26.0 +/- 8.6 ng/ml; p75: 20.5 +/- 17.4 ng/ml; mean +/- S.D.) and infected ascites (p55: 25.1 +/- 10.9 ng/ml, p75: 22.6 +/- 11.0 ng/ml) compared with patients with uncomplicated hepatic ascites (p55: 10.1 +/- 4.4 ng/ml; p75: 6.0 +/- 2.6 ng/ml). Patients with infected or malignancy-related ascites also showed higher soluble tumor necrosis factor receptor concentrations in plasma than did patients with plain hepatic ascites. Successful antibiotic treatment of peritonitis reduced soluble tumor necrosis factor receptor p55 and p75 ascites levels in three patients from 24.2 +/- 15.2 ng/ml to 10.7 +/- 1.9 ng/ml and from 20.2 +/- 14.4 ng/ml to 7.5 +/- 1.8 ng/ml, respectively. Soluble tumor necrosis factor receptors p55 and p75 at cutoff levels of 16.5 ng/ml and 9.5 ng/ml, respectively, differentiated between infected or malignant and plain hepatic ascites with diagnostic accuracies of 94% and 89%, respectively. They did not differentiate between infected and malignant ascites. The concentrations of soluble tumor necrosis factor receptor p55 were usually higher in ascites than in plasma in all subgroups of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Improvements in ion-trap chemical-ionization performance.

Ion-trap chemical-ionization performance has been improved by application of a modified scan function for the rejection of the undesired electron-ionization-like (EI-like) ions formed at the beginning of the reaction ionization period. The net effect of this software modification to the automatic reaction control is to produce chemical ionization (CI) spectra that are no longer adulterated with concentration-dependent EI-like ions. Under such improved conditions, CI spectra from an ion trap can now be directly compared with CI spectra produced on conventional quadrupole and magnet-scanning instruments.

Ions↗

Molecular aspects of Alport's syndrome.

We review the recent progress achieved on the understanding of the molecular basis of Alport's syndrome. This inherited disease is defined as progressive nephritis with sensorineural hearing loss. In 80%-85% of the families, inheritance is compatible with X-linked dominant transmission, whereas in the remaining cases autosomal dominant transmission is assumed. Histology studies demonstrated that the main defect is within the glomerular basement membrane (GBM). In addition, evidence for an altered GBM antigenicity came from immunofluorescence studies which showed a reduced or absent binding of anti-GBM autoantibodies or monoclonal antibodies to the "Goodpasture antigen" in some families. Subsequent studies added substantial evidence that Alport's syndrome is a type IV collagen disease. Genetic linkage analyses coherently identified an Alport locus at the X-chromosomal region Xq21.3-22. Recently, a previously unknown alpha 5 chain of type IV collagen was identified, and the corresponding gene was also mapped to Xq22. Subsequent studies on Alport families by various groups identified more than 25 COL4A5 lesions. Segregation in linkage with the Alport phenotype could be shown in large kindreds. Mainly deletions and only a few point mutations were described. Most lesions reported so far are heterogeneous. We were able to identify two deletions and one point mutation involving a 3' splice site in 20 Alport families from Germany. One of the patients with a COL4A5 deletion and the patient with the splice site mutation developed anti-GBM antibodies after renal transplantation. In contrast, no COL4A5 lesions have been found in 2 further patients with posttransplant anti-GBM nephritis.(ABSTRACT TRUNCATED AT 250 WORDS)

Basement Membrane↗

Transient non-cardiogenic pulmonary edema following massive ingestion of ethylene glycol butyl ether.

A case of acute poisoning with ethylene glycol butyl ether (EGBE) is reported in a chronic alcohol abuser. On admission the 53-year-old patient was comatose with metabolic acidosis, shock, and noncardiogenic pulmonary edema confirmed by haemodynamic study. Following supportive treatment and haemodialysis the outcome was favorable. The relationship between respiratory failure and EGBE is examined.

Alcoholism↗