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Biomedical subjects

H Mann

Publications and source records attributed to H Mann.

At least 73 records · Page 4Linked to original sources
PubMed1991

Intragastric long-term pH-metry in hemodialysis patients. A study with famotidine.

The onset and duration of famotidine action were studied in 14 hemodialysis (HD) patients and 16 healthy controls (control group: CG) who were examined by ambulatory intragastric 24-hour pH-metry. 20 mg famotidine was administered i.v. 90 min after HD in the afternoon (AN; 2 p.m.; n = 8) or evening (E; 8 p.m.; n = 6), followed by a standard meal. Mean onset of action in the AN and E groups of the HD patients was 90.3 +/- 28.2 min and 98.8 +/- 29.8 min, and in CG patients 36.3 +/- 11.9 min and 53.6 +/- 22.3 min, respectively (p less than 0.05). Duration of action in the AN and E groups of the HD patients was 22.7 +/- 2.1 h and 21.6 +/- 2.6 h, and in CG patients 6.0 +/- 1.1 h and 11.4 +/- 1.6 h, respectively (p less than 0.05). Our study showed a retarded and prolonged action of famotidine in HD patients. The time of administration of famotidine had no effect on its action in HD patients. This is in contrast to normal subjects in whom evening administration delays the onset and prolongs the duration of famotidine action in comparison to afternoon administration.

Adult↗
PubMed1990

[Percutaneous vascular endoprotheses for occlusions or stenoses of hemodialysis shunts].

In ten patients (four men and six women, mean age 51.7 [26-79] years), with six occlusions and five stenoses of a haemodialysis shunt or shunt-draining subclavian vein, a self-expanding intravascular stent was implanted percutaneously after balloon-dilatation. The implantation was successful in 9 of 11 instances, but the shunt thrombosed in two within 24 hours (in one of the patients, with antithrombin III deficiency, the shunt had to be abandoned). After an average observation period of 7.8 (1-14) months, ten shunts have remained open and suitable for dialysis. A further stent had to be implanted in one of the patients because of stenosis distal to the first stent. In three patients intima hyperplasia within the stent necessitated percutaneous balloon dilatation and/or atherectomy.

Adult↗
PubMed1990

Common errors in evaluating chest radiographs.

Chest radiographs that are correctly obtained and interpreted provide valuable diagnostic information. However, some radiographs are not taken at total lung capacity, and the appearance of the lungs on film may mimic certain lung disorders. Most common interpretive pitfalls in chest radiography can be avoided by physicians who are familiar with the film appearance of varying degrees of lung inflation, technical limitations of portable radiography, and common chest abnormalities. When further definition is necessary, additional projections should be obtained. Chest fluoroscopy and computed tomography can offer further clarification, if needed.

Adipose Tissue↗
PubMed1990

Kinetic modelling and continuous on-line blood volume measurement during dialysis therapy.

Changes of relative blood volume during haemodialysis therapy have been investigated using kinetic modelling and on-line blood volume registration by continuous haemoglobinometry. An exponential relation has been found between blood volume reduction per litre of ultrafiltrate and the amount of fluid overload. Between the amount of refilling and ultrafiltration rate there was also an exponential dependence. There was a linear relation between the change in plasma sodium concentration and blood volume. An acceptable correspondence was found between calculated and measured data.

Blood Volume↗
PubMed1990

Vascular leak syndrome associated with interleukin-2: chest radiographic manifestations.

Adoptive immunotherapy with interleukin-2 (IL-2) is associated with a generalized vascular leak syndrome. Pulmonary edema is a common occurrence and is rarely responsible for acute respiratory failure requiring assisted ventilation. The authors have performed a retrospective review of chest radiographs in 19 patients undergoing the priming course of high-dose IL-2 therapy for metastatic melanoma and renal cell carcinoma. This study was primarily designed to evaluate the prevalence and patterns of pulmonary edema and pleural effusions. During the first 5 days of therapy, alveolar edema was identified in 21% (n = 4) and signs of interstitial edema in 53% (n = 10) of patients. Pleural effusions were seen in 42% (n = 8). No patient in this series required assisted ventilation during this period. However, two patients subsequently developed fatal, drug-related myocardial injury. IL-2 toxicity is a well established cause of self-limited, increased-permeability pulmonary edema.

Capillary Permeability↗
PubMed1990

Short time dialysis with continuous blood volume control.

Continuous measurement of haemoglobin concentration is used to control changes of blood volume during haemodialysis. Ultrafiltration is either kept constant throughout the session or after starting with a rate (1.5 to 2 l/h), is manually controlled in order to limit blood volume reduction to a pre-set percentage. Ultrafiltration is step-wise decreased (a) or switched on and off (b) accordingly. Blood volume decrease with constant ultrafiltration is compared with method (a) and (b) in 4 stable haemodialysis patients. Constant ultrafiltration rate and the same total amount of ultrafiltrate causes a nearly 3% (mean) greater volume reduction as compared with method (a) and (b). No difference was observed in blood pressure and heart rate. We conclude that ultrafiltration in stable haemodialysis patients can be completed in short time without consequences for cardiovascular stability.

Blood Pressure↗
PubMed1989

Sonographic changes of the pancreas in chronic renal failure.

Several abnormalities regarding pancreatic morphology and function have been reported in patients with chronic renal failure (CRF) with an incidence as high as 72%. In a prospective study we investigated 96 outpatients from our chronic ambulatory hemodialysis program by abdominal ultrasound. Of the patients with CRF, 20.6% were found to have morphologic alterations of the pancreas compared to 4.7% of controls. Although pathologic sonograms of the pancreas correlated with biliary disease, hyperparathyroidism and years of hemodialysis, the most obvious etiologic factor appeared to be the duration of CRF. Possible pathogenetic mechanisms are discussed and screening abdominal ultrasound examinations in patients with long-standing CRF are recommended.

Adult↗
PubMed1989

Venous stenoses in dialysis shunts: treatment with self-expanding metallic stents.

A flexible, self-expanding metallic endoprosthesis was employed for the treatment of venous outflow stenoses in four patients with a polytetrafluoroethylene shunt and two patients with a Brescia-Cimino shunt. The stenoses had led to shunt occlusion in five patients and to flow impairment in one. In the occluded shunts, thrombectomy and subsequent balloon angioplasty were performed in four patients, and percutaneous recanalization with angioplasty was performed in one. One shunt with decreasing flow was percutaneously dilated. Since the underlying stenoses recurred in four patients after 24 hours and did not respond sufficiently to angioplasty in two patients, up to four stents were placed in the venous segments. Thrombosis of the stents occurred in two patients after 24 hours and in one after 6 weeks and was successfully recanalized with thrombectomy in two. At 2-6 months follow-up, the stents and the shunts were patent in five patients. In three of these patients, intima hyperplasia, associated with narrowing of the stent lumen in two, was noted within 4 months after stent placement.

Adult↗
PubMed1989

Isolation of unusually composed sialyl-compounds from hemofiltrate.

Sialyl compounds are essential components of various biological fluids but relatively little is known about their occurrence in the extracellular fluid of patients with end-stage renal disease. As we have developed a macropreparative method for concentrating and desalting a wide range of fractions from diluted biological fluids we have been able to isolate and identify 5 sialooligosaccharides, 3 sialosugarphosphates, 2 monosialoglycopeptides and 1 disialoglycopeptide. The structures have been elucidated predominantly by one and two-dimensional NMR spectroscopy, enzymatic degradation and FAB mass spectrometry. The accumulation of these compounds in uremic sera may be of particular interest as they may interact in the molecular biology of diseases typically associated with the uremic state, e.g., immune deficiency, neurological disorders, receptor binding abnormalities, complement system disturbances and cell membrane alterations.

Carbohydrate Conformation↗
PubMed1988

Pharmacokinetics of ranitidine in patients undergoing haemofiltration.

The pharmacokinetics of ranitidine was investigated in 11 patients with acute or end stage renal failure during haemofiltration. Each patient received 50 mg ranitidine i.v. The mean distribution and elimination half lives were 0.13 and 2.57 h, respectively. The total body clearance (CL) and volume of distribution (Vz) were 298 ml.min-1 (5.19 ml.min-1.kg-1) and 1.08 l.kg-1, respectively. About 17.1% of the administered dose was removed by haemofiltration (in approximately 20 l filtrate). Five of the patients still had some urine output and they excreted 0.1 to 11.8% of the dose in urine in 24 h. The haemofiltration clearance was 66.9 ml.min-1 at a filtrate flow rate of 86 ml.min-1, corresponding to a mean sieving coefficient of 0.78 (n = 6). As plasma concentrations were still in an effective range after haemofiltration, dose supplementation is not recommended.

Acute Kidney Injury↗
PubMed1988

Pharmacokinetics and dynamics of famotidine in patients with renal failure.

1. Famotidine, a new histamine H2-receptor antagonist was administered intravenously (20 mg) to 22 patients with end stage renal disease during a dialysis free interval (n = 6) and during different blood purification processes including haemodialysis (HD; n = 4), intermittent haemofiltration (HF; n = 4), continuous haemofiltration (CHF; n = 4) and continuous ambulatory peritoneal dialysis (CAPD; n = 4). The plasma, the dialysate/filtrate and the urine concentrations of famotidine were analysed by h.p.l.c. 2. In addition, intra-gastric pH was measured by a long-term-pH probe in seven patients with renal failure and in six patients with normal renal function (control group) following 20 mg famotidine. 3. A 7 to 10 fold prolongation of famotidine's elimination half-life (27.2 +/- 8.5 h; mean +/- s.d.) was observed in patients with renal failure as compared with the half-life (2.6-3.6 h) in subjects with normal renal function. 4. Total body clearance (CL) and volume of distribution (V) were found to be 33.5 +/- 10.1 ml min-1 and 1.3 +/- 0.7 l kg-1, respectively in patients with end-stage renal failure. 5. Blood purification processes have shown considerable variation in clearing famotidine from the body: 16.4 +/- 8.9 and 6.0 +/- 2.9% of the administered dose in HD with polysulphone and cuprophan membranes respectively, 7.7 +/- 5.2% in HF with a polyacrylonitrile membrane (each for 5 h), 4.5 +/- 1.1% in CAPD and 16.2 +/- 4.9% in CHF with a polysulphone membrane within 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗