Biomedical subjects
A Zwahlen
Publications and source records attributed to A Zwahlen.
[Renal osteodystrophy in patients on maintenance hemodialysis: statistical study of clinical, radiological and biochemical features].
Sixty radiological, clinical and biochemical features were simultaneously recorded in a population of 46 patients on maintenance hemodialysis. Radiological signs of bone reabsorption (hands, acromio-clavicular and sacro-iliac joints) were demonstrated in 65% and were quantified as a radiological index of hyperparathyroidism. The index was correlated with the levels of parathormone and of alkaline phosphatase (p less than 0.01) and with the duration of renal failure (p less than 0.01), and inversely related to bone densitometry (p less than 0.05). Discriminant analysis confirmed the redundant value of parathormone and alkaline phosphatases in predicting bone lesions. Factorial analysis showed the existence of 12 classes of patients statistically close to one another. These results demonstrate the heterogeneity of renal osteodystrophy.
[The regulation of plasma aldosterone in hemodialysis patients].
The role of potassium in regulating plasma aldosterone has been studied in 7 patients with end-stage renal disease undergoing hemodialysis. Plasma renin activity (PRA), plasma aldosterone, cortisol, sodium and potassium, and total potassium loss were measured before and after two sessions of dialysis in each patient. The only difference between the two sessions was the potassium content of the dialysate (4 mmol/l versus l mmol/l). Plasma potassium, potassium pool and plasma aldosterone decreased significantly when the patients were dialyzed with a l mmol/l K bath. In contrast, the same parameters remained unchanged when the patients were dialyzed with a 4 mmol/l K bath. Irrespective of the dialysate used, there were no differences either in changes in body weight and PRA, or in plasma sodium and cortisol levels, before and after dialysis. In conclusion, in patients with end-stage renal disease, potassium predominates over PRA and volume depletion in the regulation of plasma aldosterone.
[Acute atropinic syndrome caused by abuse of anti-asthmatic cigarettes (Datura stramonium)].
Over a 3-month period four patients (3 males and 1 female) aged 17 to 23 were admitted to an emergency unit with an acute anticholinergic syndrome. All of them had ingested aniasthmatic cigarettes containing Datura stramonium leaves for psychedelic purposes. The clinical features were characterized by striking peripheral signs of anticholinergic inhibition associated with central nervous system manifestations such with central state, hallucinations and abnormal behaviour. One patient had to be treated with physostigmine salicylate. The other three received supportive care only. The central and peripheral symptomatology subsided gradually over 12-48 hours. All four patients had more or less extensive amnesia regarding the acute toxic phase. Based on these observations, the possible causes, differential diagnosis and treatment of acute atropinic intoxication are reviewed. The discussion also considers the problem of abuse of "over-the-counter" atropine containing preparations.
[Use of strontium-89 in the analgesic treatment of bone metastases].
The analgesic properties of 89Sr were investigated in 17 patients with multiple painful bone metastases. 89Sr is a radioisotope, the metabolism of which in the body is comparable to that of calcium. It is a pure beta emitter and its half-life is 51 days. When injected intravenously it is captured by bone, especially at locations where the turnover is increased. Each patient received 1--2 mCi of 89Sr. Bone scans and hematological investigations were performed before, and 2 months after, treatment. No significant changes were found. Shealy's method was used to assess pain, initially twice a week and then at more prolonged intervals. One patient suffering from multiple myeloma showed a spectacular improvement and 6 others responded favourably. Improvement generally occurred within 3--7 days, but was sometimes delayed for up to 3 weeks. Relief lasted for up to several months. Five patients had an increase of pain during the 24 hours immediately after treatment. An average of 28% of the administered radioactive dose was found in the urine collections during the first 48 hours. Although the treatment was not successful in every case, the use of 89Sr as a long acting analgesic in multiple bone metastases should be considered more frequently, especially as there are no side effects.
[Angioimmunoblastic lymphadenopathy. 8 cases and review of the literature].
Eight cases of angio-immunoblastic lymphadenopathy were recently diagnosed at the University Hospital of Geneva. The disease was characterized by generalized adenopathy, hepatosplenomegaly, fever, and sometimes skin rash. Six patients had polyclonal dysproteinemia and two displayed autoimmune disorders, e.g. Coombs' positive hemolytic anemia. Lymph node biopsy was a decisive pointer for the diagnosis. Four patients died, two of them from immunoblastic lymphoma. Four other patients are in remission, the longest follow-up being 91 months. Analysis of 213 cases from the literature shows the following features:--Males and females are equally affected, with a predominance after the age of 50.--The onset is characterized by constitutional symptoms (75%) and fever (65%), sometimes following exposure to drugs.--The signs are generalized adenopathy (91%), splenomegaly (66%), hepatomeagly (65%), and skin rash (46).--Polyclonal hypergammaglobulinemia (76%) is found, together with anemia (78%) which is often autoimmune in origin (58%).--The course is often unfavourable and the mortality is over 55%, largely due to opportunistic infections and/or development of immunoblastic lymphoma.
[Acute epiglottitides in the adult].
Two adults were admitted to the University Hospital of Geneva with acute Haemophilus influenzae type b epiglottitis. The disease was characterized by rapid progression of sore throat, upper dysphagia, fever and dyspnea. Acute upper airway obstruction required emergency tracheotomy in both cases. The patients recovered under ampicillin therapy. All the 100 cases from the literature for which clinical data were available have been analyzed:--Epiglottitis in adult is not exceptional.--Haemophilus influenzae type b is the most common infective organism documented, and was found in all positive blood cultures but one.--The typical presentation is severe sore throat, with upper dysphagia, fever and dyspnea.--Clinical course is rapid and serious, and acute respiratory distress develops in 57% of cases; overall mortality is 27%.--Emergency routine tracheotomy appears to be the most reliable treatment.
["Paralytic shellfish poisoning" (author's transl)].
In October 1976 an epidemic of 120 cases of paralytic shellfish poisoning was recorded in western Europe. Analysis of the 23 cases seen in Swizterland shows the following data; paresthesia of mouth and lips (100%); cerebellar syndrome (86%) with giddiness, ataxia, dysmetry and floating sensation; paresia or paralysis (62%); digestive symptoms (14%); no death. The mean incubation time is 3 hs 30 min; mean duration of the symptoms is 2 days. Half of the patients complain of asthenia and moderate memory disturbance lasting up to 3 weeks. The severity of the illness is in relation to the amount of ingested neurotoxin. The epidemiologic study shows that all European cases were due to consumption of mussels from the Atlantic coast of Spain.
Symptoms of shellfish poisoning.
Explore the source record for details and available documents.
[Radiological aspects of secondary hyperparathyroidism in chronic renal insufficiency (author's transl)].
Explore the source record for details and available documents.
Nonmalignant monoclonal immunoglobulinemia, pernicious anemia and gastric carcinoma. A model of immunologic dysfunction. Report of two cases and review of the literature.
The association of an autoimmune disease with a monoclonal immunoglobulin is not exceptional and most probably results from a dysfunction of the immunologic apparatus. This study describes two patients with monoclonal immunoglobulin A (IgA) and M (IgM) gammopathy, respectively, in whom pernicious anemia and finally gastric carcinoma developed. One patient had autoantibodies to gastric parietal cell and to thyroid microsomal antigen which could not be identified with the M-component. This observation, together with the fact that pernicious anemia occurred in one case before and in the other case after the discovery of M-component, suggests that different clones of cells were responsible for both disorders. Sixteen cases in which the patients had the same association have been collected from the literature and the data are compared with ours.
"Contractile interstitial cells" in pulmonary alveolar septa: a possible regulator of ventilation-perfusion ratio? Ultrastructural, immunofluorescence, and in vitro studies.
In the lungs of healthy rats, humans, lambs, and monkeys, about 50% of the alveolar interstitial cells-resembling fibroblasts-contain bundles of fibrils measuring 30-80 A in diameter. Immunofluorescence studies on frozen sections of rat lung demonstrate that many interstitial cells bind sera containing antiactin antibodies. On account of these two sets of findings and our additional in vitro studies suggesting alveolar tissue contraction due to hypoxia or epinephrine, we postulate that the alveolar septa contain contractile cells different from that of smooth muscle. For these cells we propose the name of "contractile interstitial cells." Such cells lie within the thick portion of the air-blood barrier and around the pre- or postcapillary vessels. Hence it is possible that they play a role in the autoregulation of ventilation/perfusion (V/Q) ratio, particularly in hypoxic pulmonary hypertension. These findings, demonstrating a contractile system other than bronchial and arterial smooth muscle, suggest that the alveolus should no more be conceived as a passive "organ."
Haemophilus influenzae disease in the White Mountain Apaches: molecular epidemiology of a high risk population.
Based on a 10-year retrospective and a 15-month prospective analysis, White Mountain Apache Indian children younger than 5 years were found to have an annual incidence of Haemophilus influenzae meningitis of 254 cases/100,000--an 8-fold higher incidence than that seen in the general United States population. In our prospective surveillance, H. influenzae isolates from cases of systemic disease were further characterized by capsular type, biotype and by outer membrane protein (OMP) and lipopolysaccharide (LPS) patterns on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Unexpectedly, H. influenzae type a strains were isolated in 3/18 cases of systemic disease. All other disease-producing strains were type b. H. influenzae b strains possessing common OMP, LPS, capsular and biotype characteristics were isolated from individuals in geographically distinct communities within the reservation. These apparently identical strains were isolated from different individuals who had systemic infections that occurred months apart (longest interval, 14 months). Both OMP and LPS subtyping were necessary to discriminate among invasive H. influenzae isolates.