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Biomedical subjects

J Weber

Publications and source records attributed to J Weber.

At least 397 records · Page 22Linked to original sources
PubMed1991

[Lye corrosion of the esophagus. Course under long-term bougienage].

In an alcoholic state a 61-year-old woman swallowed by mistake about 125 ml of a lye-containing glass-washing liquid (pH 12). About 30 min later she repeatedly brought up blood-containing vomitus and was admitted to hospital. Extensive corrosive damage in the oesophagus and entire stomach developed within a few days. Two weeks later a circular narrowing of the oesophageal lumen, which could not be passed endoscopically, was seen. Afterwards she repeatedly underwent endoscopic bougie dilatation. At the third dilatation the oesophagus was perforated, mediastinitis occurred but responded without further problems to conservative medical treatment. Two months after the initial injury a Billroth II gastric resection was performed because of complete stenosis of the gastric exit. Bougie dilatation was continued at widening intervals for 18 months after the ingestion. Subsequently the patient has remained without symptoms, although a secondary Barrett oesophagus has developed at the oesophago-gastric junction which, because of the potential danger of malignant degeneration, will require regular follow-up.

Accidents, Home↗
PubMed1991

[Esophageal motility disorders with thoracic pain of unknown origin].

35 patients with angina-like chest pain underwent esophageal manometry after a coronary artery disease had been ruled out by angiography. Furthermore, patients after gastric or esophageal surgery, with pathologic upper gastrointestinal endoscopy or with pathologic gastroesophageal reflux as seen on 24-hour-pH-metry were excluded from this study. 29 out of 35 patients (83%) had a normal manometric study, six patients (17%) had a motility disorder; five of these showed an unspecific dismotility pattern and were asymptomatic while the study was done; only one patient presented with esophageal spasm. Since only this latter patient was symptomatic while the study was done, a correlation between symptoms and this motility disorder seems likely. --If pathologic gastroesophageal reflux has been ruled out, esophageal manometry can establish a diagnosis in only 3% of patients with angina-like chest pain without esophageal symptoms (dysphagia, odynophagia, heartburn or regurgitation). We conclude that this complicated examination should not be done in these patients.

Adult↗
PubMed1991

[Continuous ambulatory peritoneal dialysis. Patient and method survival rate, peritonitis incidence and dialysis efficacy over 10 years].

From 1979 to 1989, continuous ambulatory peritoneal dialysis (CAPD) was undertaken for terminal renal failure in 104 patients (56 women and 48 men; average age 54 +/- 15.3 years at the onset of dialysis), for a total observation period of 175 patients years. Survival rate for patients and methods and dialysis effectiveness were analysed retrospectively, the incidence of peritonitis prospectively, 40 patients were aged 60 years and over. Diabetic nephropathy was the most common cause of terminal renal failure (44%). Cumulative patient survival rate was 80% in the first year of treatment; 57% of patients were still alive after two years. The cause of death in 45 of the 54 patients who had died was unrelated to CAPD, cardiac disease and cerebrovascular accident being the most frequent causes (n = 26). During the first treatment year 47% of patients contracted bacterial peritonitis, 59% during the first two years. In 9% of patients CAPD had to be discontinued within the first two treatment years because of CAPD-related complications. There was no case of sclerosing peritonitis or of ultrafiltration loss forcing CAPD termination. These data indicate that there is no plausible explanation from a medical viewpoint for the highly restrictive use of CAPD in the Federal Republic of Germany.

Combined Modality Therapy↗
PubMed1991

Relation between humoral responses to HIV gag and env proteins at seroconversion and clinical outcome of HIV infection.

OBJECTIVE: To study the contribution of the humoral response to HIV-I at seroconversion to disease outcome after 84 months. DESIGN: A retrospective longitudinal study. SETTING: Two haemophilia centres in the United Kingdom. PATIENTS: 88 Haemophiliac patients infected with HIV-I for whom sera were available from before seroconversion and in whom clinical follow up data were available. RESULTS: Kaplan-Meier survival analysis showed a significant difference between a high titre (greater than 1600) p24 antibody response at seroconversion and prolonged time before the development of HIV related disease (p = 0.0008). In contrast, higher titres of antibody to gp120 at seroconversion (greater than 25,600) correlated with more rapid clinical deterioration (p = 0.025). CONCLUSIONS: The first humoral response to HIV proteins at seroconversion is associated with clinical outcome; patients with an initial low titre antibody response to the gagp24 protein have a significantly faster rate of progression to CDC stage IV disease. Patients with a high titre p24 antibody response progress to AIDS more slowly, and these data provide an explanation why p24 antigenaemia is not universally detected in patients with AIDS. It is unclear whether the association between a strong initial p24 antibody response and slower progression of HIV disease is causal and if so whether it is due to viral or host factors.

Gene Products, gag↗
PubMed1991

The paradox of adult respiratory distress syndrome in neonates.

Six full-term newborn infants are described who suffered from severe adult respiratory distress syndrome (ARDS). The triggering event was intrauterine/perinatal asphyxia in five, and group B streptococcal (GBS) septicemia in three. All had severe respiratory distress/failure and were ventilated mechanically with high concentrations of inspired oxygen and positive end-expiratory pressure. Radiography of the chest showed dense bilateral consolidation with air bronchograms and reduced lung volume. Persistent pulmonary hypertension (PPH) was documented in all cases. The coincidence of ARDS and PPH rendered respiratory management extremely difficult. For this reason high-frequency ventilation was instituted in all patients in order to improve CO2 elimination and induce respiratory alkalosis. Acute complications of respiratory therapy were encountered in five patients (pneumothorax, pulmonary interstitial emphysema, pneumopericardium). Three infants died (irreversible septic shock, progressive severe hypoxemia, and sudden cardiac arrest) after 17, 80, and 175 h of life. Histologic examination of the lungs was possible in all fatal cases and revealed typical changes of acute to subacute stages of ARDS. Three infants survived, the mean time of mechanical respiratory support being 703 h. Two patients were still dependent on oxygen after 1 month of life, and all survivors had increased interstitial markings and increased lung volumes on their chest roentgenograms at this time.

Asphyxia Neonatorum↗
PubMed1991

Structural investigations and modeling of cavities in clathrates.

A molecular-graphics study has been performed in order to build and visualize the shape of cavities within different clathrates from X-ray diffraction data [e.g. Dianin's compound, Werner complexes Ni(SCN)2(3-methylpyridine)4, Fe(acetylacetonate)3 and Ni(ethylxanthate)2(4,4'-dimethyl-2,2'-bipyridyl) complexes]. The algorithm of the solvent-accessible surfaces representation has been applied to a part of the whole crystal structure rather than to isolated host molecules, by using the MOLCAD molecular modeling package. This type of modelization has been found very efficient both to study the shape properties of the host cavities (cage or channel types) and to approach the structural features of the host/guest interactions.

Computer Systems↗
PubMed1991

A perimetric nerve fiber bundle map.

The so-called 'nerve fiber bundle defects' in the visual field are considered as being the functional equivalent of retinal nerve fiber bundle damage. This study examines the course and the position of scotoma borders in 159 visual fields with complete nerve fiber bundle defects using high resolution test point patterns. The scotoma border lines were averaged geometrically. The result is presented in the form of mean vectors. This functional map of nerve fiber lines shows a close correspondence to the anatomical course of the retinal nerve fibers. To make the result suitable for topographical analysis of visual fields, 21 areas ('Perimetric Nerve Fiber Bundles') are defined. Certain arbitrary assumptions were necessary because data were to scanty in some nasal regions. Also, the lines had to be fitted into a rectangular grid to be transferable to standard perimetric patterns. Topographical analysis on the basis of these areas may be useful for the evaluation of visual fields, particularly those of glaucoma.

Glaucoma↗
PubMed1991

External anal sphincter function in spinal patients. Electromyographic and manometric study.

Six patients with complete transection of the spinal cord and six healthy volunteers were examined by using anorectal manometry together with electromyographic (EMG) recording of the external anal sphincter composed of striated muscle. Anal pressure and EMG activity of the external anal sphincter were continuously recorded at rest and during gradual rectal distention (10, 20, 30, 40, and 50 ml) by means of an air-filled balloon eliciting a rectoanal inhibitory reflex (RAIR) at the upper part, and an inflation reflex (IR) at the lower part of the anal canal. All patients and controls had a RAIR for each rectal distention volume. A relationship between the duration of the RAIR and the rectal distention volume was present in controls only. In controls the IR was present for each rectal distention volume, whereas it was present in only one patient for a 40-ml volume. During the resting period, all controls showed continuous tonic EMG activity of the external anal sphincter, but after 30 minutes all the patients showed a decrease and ultimately in five cases a disappearance of the tonic EMG activity of the external anal sphincter. In spinal patients, the presence or absence of EMG activity of the external anal sphincter did not modify the anal canal pressure. These results indicate that: 1) the tonic EMG activity of the external anal sphincter seems to be under the control of supraspinal structures, because in spinal patients it disappears in the absence of sensitive inputs toward the spinal cord; 2) the absence of EMG activity at rest indicates that the external anal sphincter is not implicated in the RAIR disturbances observed in spinal patients; 3) the IR is not a spinal reflex but is under voluntary control, because it is not present in spinal humans; 4) in spinal humans the tonic EMG activity of the external anal sphincter does not play a role in the maintenance of the anal pressure at rest.

Adolescent↗
PubMed1991

An extract from Hydra vulgaris (Cnidaria) nematocysts increases cytoplasmic Ca2+ levels in fibroblasts.

It was previously shown that a toxic protein present in an extract prepared from nematocysts of Hydra vulgaris (Cnidaria) is highly hemolytic and induces spasms in test animals (Klug et al., 1989, Toxicon 27, 325). We now demonstrate that this nematocyst extract affects cell viability and induces an increase of cytosolic Ca2+ concentration as measured in fura-2 loaded single fibroblasts. This increase is caused by Ca2+ entering from the external medium and the effect appears to be due to the hemolytic component of the venom.

Animals↗
PubMed1991

In vivo effect of 1,25-dihydroxyvitamin D3 on phagocyte function in hemodialysis patients.

1,25-dihydroxyvitamin D3 [1,25(OH)2D3] has been shown to modulate the immune function of monocytes and macrophages. Patients with end-stage renal disease (ESRD) on chronic hemodialysis treatment usually present a deficiency of this active form of vitamin D3. The aim of this study was to investigate the effect of 1,25(OH)2D3 replacement therapy on phagocytosis, bactericidal capacity, and oxidative metabolism of peripheral blood polymorphonuclear leukocytes (PMNL) and monocytes (MN) in chronic hemodialysis patients. Phagocyte function tests were performed before and after four weeks of an oral replacement therapy with 0.5 micrograms/day of 1,25(OH)2D3 (Rocaltrol). The superoxide (O2-) generation of monocytes, measured by cytochrome c reduction and lucigenin-enhanced chemiluminescence (CL) from patients receiving hemodialysis treatment was significantly diminished compared to healthy controls. After the replacement therapy with 1,25(OH)2D3 the O2- production showed a significant improvement, resulting in an increased cytochrome c reduction and lucigenin-CL response. The bactericidal capacity of MN was also impaired and exhibited a significant enhancement of their killing activity after the administration of 1,25(OH)2D3. On the other hand, the luminol-enhanced CL, which reflects the myeloperoxidase-dependent oxidative metabolism, and the phagocytic ability of MN was not affected by the hormone. The function of polymorphonuclear leukocytes (PMNL) from hemodialysis patients showed no impairment in the state of 1,25(OH)2D3 deficiency and the replacement of the hormone did not enhance their function. These results suggest that the deficiency of 1,25(OH)2D3 in patients with ESRD on chronic hemodialysis treatment may be responsible for an impaired monocyte function, which could be improved by an in vivo replacement of the hormone.

Adult↗