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Biomedical subjects

J Weber

Publications and source records attributed to J Weber.

At least 343 records · Page 19Linked to original sources
PubMed1993

Incidence and significance of pneumoperitoneum in continuous ambulatory peritoneal dialysis.

In a retrospective study we reviewed upright chest x-ray films of 101 continuous ambulatory peritoneal dialysis (CAPD) patients to determine the incidence and significance of free subdiaphragmal air. A pneumoperitoneum (PP) was diagnosed if a minimal shadow of free air was detected under the diaphragm. The amount of free air was determined by measuring the height and width of the subdiaphragmal air shadow. Of all CAPD patients, 33.6% (34 of 101) had at least one occurrence of PP. Thirteen of these 34 patients (38.2%) were diagnosed within 30 days after catheter implantation, 10 patients (29.5%) acquired a PP during an episode of peritonitis, and in 11 patients (32.4%) no additional risk factor could be determined. Patients radiographed within 30 days after catheter implantation showed a statistically significant higher incidence of PP compared with the same patients radiographed later (22% v 10%; P < 0.05). The incidence of PP in CAPD patients suffering from peritonitis (33%) was significantly higher than in patients without peritonitis (10%; P < 0.001). The amount of free air did not differ statistically significantly between the investigated groups. Only two patients with PP and peritonitis had surgically confirmed visceral perforation. Therefore, the main reason for PP seemed to be handling faults during CAPD bag exchange. There was no correlation between the organisms causing peritonitis and PP or the CAPD connector system and PP. In conclusion, a PP occurs in approximately one third of all CAPD patients and a visceral perforation cannot be diagnosed by the occurrence and amount of free subdiaphragmal air.

Adolescent↗
PubMed1993

Chromosomal assignment of the second locus for autosomal dominant cerebellar ataxia (SCA2) to chromosome 12q23-24.1.

The autosomal dominant cerebellar ataxias (ADCA) are a group of neurodegenerative disorders characterized by onset with gait ataxia, dysarthria, dysmetria and dysdiadochokinesia. We have demonstrated previously genetic heterogeneity within these disorders by excluding the disease locus from the documented spinocerebellar ataxia locus (SCA1) on chromosome 6p in a large Cuban founder population. We now report the assignment of a second locus for ADCA (SCA2) to chromosome 12q23-24.1 following linkage analyses carried out for the Cuban pedigrees, with probable flanking markers D12S58 and phospholipase A2. Investigation of linkage to the interval containing SCA2 for seven French ADCA families, previously excluded from linkage to SCA1, provides preliminary data suggesting the existence of a third ADCA locus (SCA3).

Chromosome Mapping↗
PubMed1993

Epidermal Langerhans cells in uremic patients on hemodialysis or continuous ambulatory peritoneal dialysis.

Skin biopsies of 33 uremic patients-13 patients on continuous ambulatory peritoneal dialysis (CAPD), 12 on hemodialysis (HD), 8 patients with end-stage renal disease (ESRD) before initiation of dialysis treatment-and 10 healthy volunteers were investigated to determine the number of Langerhans cells (LC) by light microscopy after staining for S-100 protein. The epidermal LC count was significantly lower in patients on CAPD (mean: 62.9 LC/mm2; p = 0.027) and patients on HD (mean: 30.4 LC/mm2; p = 0.0015) compared to controls (mean: 110.1 LC/mm2) and uremic patients before initiation of dialysis treatment (mean: 122.6 LC/mm2). The difference between LC counts of CAPD and HD patients did not reach statistical significance (p = 0.057). There was no relation between LC count and age (p = 0.057) or epidermal width (p = 0.26). No statistically significant correlation could be demonstrated between duration of dialysis and LC count (r = -0.33, p = 0.10). LC counts of CAPD patients with diabetes mellitus (n = 7) were not significantly different from those of nondiabetics (n = 6; p = 0.77). LC counts seem to be normal in uremic patients before dialysis treatment. The reduction in LC density in the skin of dialysis patients may contribute to immunodeficiency of uremic patients on regular dialysis treatment.

Adult↗
PubMed1993

Phase I trial of subcutaneous interleukin-6 in patients with advanced malignancies.

PURPOSE: Based on preclinical evidence in murine models that interleukin-6 (IL-6) mediates regression of metastatic tumors, we performed a phase I study of recombinant human IL-6 in patients with refractory advanced malignancies to determine its pharmacokinetics, toxicities, and possible immunologic and antitumor effects. PATIENTS AND METHODS: Recombinant IL-6 was administered as a single subcutaneous dose daily for 7 days, with 7 days off therapy followed by another 7 days of IL-6. Doses were escalated in cohorts of three patients starting at 3 micrograms/kg/d, provided that toxicity at the preceding dose level was not dose-limiting. Dose-limiting toxicity was defined as grade III or IV major organ toxicity that did not resolve to grade II or less in 24 hours after stopping IL-6, using the National Cancer Institute Common Toxicity Criteria. Patients were treated with 3, 10, and 30 micrograms/kg/d IL-6 subcutaneously. RESULTS: Three patients each were treated at the 3- and 10-micrograms dose levels. Two of five patients treated with 30 micrograms/kg/d IL-6 subcutaneously had grade III major organ toxicity that required IL-6 therapy to be discontinued. All patients experienced fever, chills, and minor fatigue. Significant increases in C-reactive protein (CRP), fibrinogen, platelet counts, and lymphocyte IL-2 receptor levels were seen in patients at the 10- and 30-micrograms/kg dose levels. Decreases in albumin and hemoglobin were observed, particularly at the 30-micrograms/kg dose level. The half-life (T1/2 beta) was 4.2 hours, with a peak IL-6 level at 5 hours. No antitumor responses were seen. CONCLUSION: A safely tolerated dose of daily subcutaneous IL-6 is 10 micrograms/kg, with hepatotoxicity and cardiac arrhythmia being the dose-limiting toxicities at 30 micrograms/kg. Phase II trials of IL-6 administered subcutaneously daily for at least 7 days for two cycles with an intervening week of rest are recommended for phase II trials. However, patients with extensive replacement of liver by tumor and abnormal liver functions should receive IL-6 therapy with caution.

Acute-Phase Proteins↗
PubMed1993

North Carolina macular dystrophy (MCDR1). A review and refined mapping to 6q14-q16.2.

The macular degenerations comprise a heterogeneous group of diseases, generally reported in small families. Single, large family studies of North Carolina macular dystrophy have aided in defining the spectrum of the phenotype of this disorder and its relationship to other macular degenerations. North Carolina macular dystrophy has many phenotypic similarities to age-related macular degeneration with the glaring exception of the early age of onset of North Carolina macular dystrophy. The authors initially reported mapping this disease by linkage to the long arm of chromosome 6. They now report additional data on a total of 247 individuals in the original North Carolina macular dystrophy family whom we ascertained for clinical and molecular genetic studies. Standard clinical ophthalmic examination revealed that 96 of these individuals were affected. Molecular genetic studies increased the LOD score to 23 and refined the genomic localization of the disease-causing gene to 6q14-q16.2.

Adult↗
PubMed1993

[Venous aneurysms].

Incidence, etiology, diagnostic procedures and therapy of venous aneurysms, basing on 152 own cases, are discussed. The main procedure for diagnosis is phlebography. It must be distinguished between aneurysms of epi- and subfascial veins. The localization determines the surgical procedure which represents the only successful therapy. Without proper treatment, venous aneurysms may be responsible for complications such as thrombophlebitis, thrombosis with pulmonary embolism, aneurysm rupture and compression of adjacent structures. The results of surgical treatment are excellent.

Aneurysm↗
PubMed1993

Intraocular pressure and visual field decay in chronic glaucoma.

A total of 41 eyes of 28 patients with primary open-angle glaucoma and low-tension glaucoma (group 1) were followed for 12-72 months with tonometry and automated perimetry. A second group consisting of 13 eyes (9 patients) with secondary glaucoma (pigment dispersion, goniodysgenesis, ciliolenticular block and chronic angle closure) was followed for 13-60 months. None of the eyes had undergone filtering surgery during the follow-up period. The visual field decay was calculated by means of regression analysis of the mean defect. There was a significant correlation between visual field decay and both mean intraocular pressure (IOP, P > 95%) and maximal IOP (P > 98%) in the secondary glaucomas, which was not found in group 1. IOP oscillation expressed by the standard deviation of IOP was significantly correlated with progressive visual field loss in both groups. The slope of visual field decay was independent of the functional damage at the initial examination. Even if the influence of IOP level on the course of primary chronic glaucoma may have been masked by other factors that have a great interindividual variation, the oscillation of IOP seems to be at least as important as the level of IOP.

Adult↗
PubMed1993

Survival of 138 surgically placed straight double-cuff Tenckhoff catheters in patients on continuous ambulatory peritoneal dialysis.

OBJECTIVE: To determine the natural history of a surgically placed Tenckhoff catheter in patients on continuous ambulatory peritoneal dialysis (CAPD). DESIGN: Prospective 7-year study analyzing catheter survival of all catheters using the Kaplan-Meier life table methodology. SETTING: Teaching hospital, department of nephrology. PATIENTS: One hundred and fifteen unselected patients beginning CAPD. INTERVENTIONS: Removal of the catheter required for the following complications: exit-site or tunnel infections or relapsing peritonitis, outflow obstruction, pericatheter leak, and development of hernias. MAIN OUTCOME MEASURES: Period between insertion and removal of the catheter. RESULTS: The cumulative survival of all catheters after 1, 2, and 3 years of CAPD was 87%, 69% and 65%. Catheter survival of the first versus the second catheter after 1 year was significantly longer (p = 0.03). The difference was not significant in relation to diabetes, age, and sex. Infectious complications caused 61% (n = 19) of all 31 catheter failures, mainly due to tunnel infections caused by Staphylococcus aureus (n = 12). "Mechanical" complications accounted for 49% (n = 12) of catheter failures. Eight of 12 mechanical complications were outflow failures. Seven patients had to be transferred to hemodialysis. CONCLUSIONS: The straight Tenckhoff catheter is a reliable peritoneal access device for CAPD in an unselected patient population.

Catheters, Indwelling↗
PubMed1993

[New diagnostic aids in automatic perimetry].

The Conformity Analysis is a new procedure for objective recognition of specific defect patterns in automated perimetry. The "Conformity Index," the measure of conformity between the distribution of defect values and several standard defect patterns, is calculated from the ratio of global variance and mean variance in particular regions. Using 68 visual fields from 68 normal persons, we determined normal values and limits of the Conformity Index for seven standard defect patterns: hemifields right-left, hemifields upper-lower, quadrants, sectors, rings with 5 degrees and 10 degrees radius interval and the perimetric nerve fiber bundles of Weber and Ulrich. The evaluation of 148 visual fields (68 normal eyes, 80 eyes with chronic glaucoma and all stages of damage) by both the Conformity Index and two experienced clinicians revealed an identical result in 89%. Using the Conformity Analysis in 37 cases of pituitary adenoma, we could objectively identify quadrants, sectors and hemifields right-left to be the most common defect patterns in this disease. In glaucoma fields with marked damage (n = 46), the most frequent pathological Conformity Index was the index for perimetric nerve fiber bundles.

Adenoma↗
PubMed1993

[Multivariate analysis of clinical signs, parameters of anorectal manometry, defecography, transit time of radiopaque markers in 76 patients complaining of fecal incontinence].

The aim of this study was to evaluate clinical symptoms, disease past-history, and parameters of anorectal manometry, defecography, and radiopaque pellet transit time in anal incontinence by multivariate analysis. We studied 76 patients, 68 women and 8 men, who complained of anal incontinence, excluding that due to obstetrical lesions. All patients were asked to complete a standard questionnaire. Results indicated that: a) hemorrhoidectomy, hysterectomy, and cholecystectomy appeared to play a role, b) daily incontinence for air or liquid stools is more frequent after hemorrhoidectomy, c) decreased resting pressure of the upper part of the anal canal was observed mainly after hysterectomy, d) decreased resting pressure of the upper part of the anal canal could be a factor of poor prognosis after treatment, e) anal incontinence in men was secondary to traumatic lesions of the anal sphincter in 7 of 8 cases.

Adult↗
PubMed1992

Is clearance of HIV-1 viraemia at seroconversion mediated by neutralising antibodies?

The mechanism of clearance of human immunodeficiency virus-1 (HIV-1) viraemia is not fully understood. In two patients with acute HIV-1 infection, initial high titres of free infectious virus in plasma declined rapidly to undetectable levels within 4-8 weeks, an event that was coincident with seroconversion. Neutralising antibodies directed against the first autologous isolates taken during the viraemic periods could not be detected in either patient around the time of disappearance of plasma virus. In the absence of functional neutralising antibody, it is unlikely that humoral factors are responsible for the suppression of primary viraemia in early HIV infection.

Adult↗