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Biomedical subjects

H Mann

Publications and source records attributed to H Mann.

At least 19 recordsLinked to original sources
PubMed1992

Sonographic evaluation of gallbladder motility in patients with end-stage renal disease on haemodialysis.

Thirty nine patients with end-stage renal disease on haemodialysis therapy with upper gastrointestinal symptoms were investigated for gallbladder motor function as the cause of their symptoms using cholecystosonography in fasting state, after a cholecystokinetic agent (BILOPTIN fatty meal) and after a smooth muscle relaxant (BUSCOPAN). Forty healthy individuals served as a control group. No significant difference was found between dialysis patients and healthy controls regarding the gallbladder area during fasting state, or the variation in the area of gallbladder during maximal contraction and dilatation. However, the patients on dialysis therapy of longer duration had stronger gallbladder contraction in response to a cholecystokinetic agent. Serum gastrin concentrations were increased in haemodialysis patients, but there was no consistent relationship between serum gastrin and gallbladder motility. The upper gastrointestinal symptoms of dialysis patients are unlikely to be due to disturbed gallbladder motility.

Adult↗
PubMed1992

[Measurement of mitral flow at the extremity of the valves. Validation of a simplified method based on 101 cases].

The measurement of cardiac output at the extremity of the mitral cusps, by Doppler-echocardiography, is of fundamental value, in particular for the evaluation of valve regurgitation. However, it comes up against a theoretical difficulty resulting from constant variation in the surface area of this orifice during diastole. After reviewing the main measurement methods available in the literature, a simplified method based upon the diameter of the ring and calculation of a mean diastolic intercusp distance by TM is suggested. Evaluation of this technique in 101 patients free of valve of leak showed its feasibility to be close to 100% and the correlation with aortic (r = 0.90), pulmonary (r = 0.91) and mitral ring (r = 0.88) outputs was entirely satisfactory. Our method would thus seem to be a good compromise between digitalised integration methods for the measurement of mitral surface area--optimal but complex--and the aim of simplification compatible with routine clinical use.

Adult↗
PubMed1992

Immunoreactive parathyroid hormone after volume change in normo- and hypotensive hemodialysis patients.

The effects of reduced blood volume during hemodialysis on circulating immunoreactive parathyroid hormone (PTH) were determined in relation to changes in blood pressure and heart rate in normo- and hypotensive patients with end stage renal failure. During dialysis the plasma concentration of PTH did not change in normotensives, while PTH increased significantly in patients with a fall in blood pressure during a 25% reduction in effective intravascular volume. The blood volume was measured continuously during hemodialysis using the authors' hemoglobin measurement system. The decrease in blood volume in both groups was comparable. The results suggest that secretion of PTH during hemodialysis may play a role in hemodynamic instability during hemodialysis.

Adult↗
PubMed1991

[Cigarette smoking and psychosocial work stress in middle-management employees].

The association between psychosocial work stress and cigarette smoking is analyzed in a socioeconomically and professionally homogeneous group of 163 middle managers (40-55 years; 48.4 +/- 4.5) in a large industrial company. Psychosocial stress is defined in terms of an imbalance between effort spent and reward obtained at work. The relative risk of regular smoking is 4.34 (odds ratio after controlling for age; 95% CI 1.50-12.54) in those middle managers who suffer from a marked imbalance between effort and reward, compared to those who are free from this type of psychosocial stress at work. This effect persists in the older age group although the proportion of smokers decreases with age. Within the group of regular smokers, every second middle manager suffering from a marked imbalance between effort and reward is a heavy smoker (greater than or equal to 20 cigarettes/day) whereas in the group experiencing less stress at work, only 28% heavy smokers are found. However, due to small numbers this difference is not statistically significant. In conclusion, the data reported in this study demonstrate an association between psychosocial stress at work in terms of high effort and low reward and the risk of regular smoking. This association is not confounded by age, socio-economic status or type of occupation.

Administrative Personnel↗
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↗