Biomedical subjects
Publications and source records attributed to E Straumann.
Short- and long-term results for DDD pacing using a single-pass DDD lead are presented for 3 patients. Single-lead DDD pacing is feasible and may provide major advantages by eliminating the necessity of a second lead.
The case of a 45-year-old woman with pheochromocytoma, who presented with severe abdominal pain and headache, diabetes mellitus, lactic acidosis and pulmonary edema, is described and discussed. Spleen infarction, not so far described as an ischemic complication of pheochromocytoma, was seen in computer tomography. After medical pretreatment with labetalol, a pheochromocytoma (2 x 2 cm) of the left adrenal gland was removed. The postoperative course was uneventful.
We report on a boy with mosaic trisomy 15. The clinical manifestations are compared with those of the few cases reported up to now. A clinical syndrome is delineated consisting of a characteristic shape of the nose and other minor craniofacial anomalies, as well as typical deformities of the hands and feet. Different degrees of mosaicism may explain the more or less severe manifestations in individual patients.
OBJECTIVE: To assess the risk of aortic valve replacement and long-term follow-up in elderly patients with dominant aortic stenosis. DESIGN: Retrospective analysis of patients who had aortic valve replacement over a 10 year period and were routinely seen in an outpatient clinic. SETTING: University hospital. PATIENTS: 93 patients aged > or = 60 and 47 patients > or = 70 years with symptomatic aortic stenosis undergoing aortic valve replacement. MAIN OUTCOME MEASURES: Early and late mortality in different age groups. Influence of preoperative signs and symptoms on overall outcome. RESULTS: The proportion of patients older than 70 years increased from 11% in 1978 to 54% in 1986. Perioperative mortality was 3.6% and mortality after 2 and 5 years was 9% and 13% respectively. Survival was similar (85% and 83%, respectively) in patients aged 60-69 years (group 1, n = 93, mean age 64.5 (2.7) and patients aged > or = 70 years (group 2, n = 47, mean age 72.6 (2.5)). Additional coronary artery disease and coronary bypass grafting did not significantly affect survival. The cardiothoracic ratio was inversely related to survival (Cox regression, p < 0.05). Preoperative symptoms (syncope, angina pectoris, and dyspnoea) were similar in both patient groups. After a mean (SD) follow up of 51 (33) months 96% of surviving patients were in NYHA functional class I or II with no difference between the two age groups. Similarly, the cardiothoracic ratio and Sokolow index decreased to near normal values in both age groups. CONCLUSION: The risk of aortic valve replacement in patients with dominant aortic stenosis is low and not significantly influenced by age. Therefore replacement may be performed without increased risk in elderly patients and with a good long-term outcome.
The effects of acute pH changes on whole body leucine kinetics (1-13C-leucine infusion technique) were determined in normal subjects. Plasma insulin, glucagon, and growth hormone concentrations were kept constant by somatostatin and replacement infusions of the three hormones. When acidosis was produced by ingestion of NH4Cl (4 mmol kg-1 p.os; n = 8) arterialized pH decreased within 3 h from 7.39 +/- 0.01 to 7.31 +/- 0.01 (P less than 0.001) and leucine plasma appearance increased by 0.13 +/- 0.04 mumol kg-1 min-1 (P less than 0.02); in contrast, when alkalosis was produced by intravenous infusion of 4 mmol kg-1 NaHCO3 (n = 7, pH 7.47 +/- 0.01), leucine plasma appearance decreased by -0.09 +/- 0.04 mumol kg-1 min-1 (P less than 0.01 vs. acidosis). Whole body leucine flux also increased during acidosis compared to alkalosis (P less than 0.05), suggesting an increase in whole body protein breakdown during acidosis. Apparent leucine oxidation increased during acidosis compared to alkalosis (P = 0.05). Net forearm leucine exchange remained unaffected by acute pH changes. Plasma FFA concentrations decreased during acidosis by -107 +/- 67 mumol l-1 (P less than 0.05) and plasma glucose increased by 1.90 +/- 0.25 mmol l-1 (P less than 0.02); in contrast, alkalosis resulted in an increase in plasma FFA by 83 +/- 40 mumol l-1 (P less than 0.02; P less than 0.01 vs. acidosis), suggesting an increase in lipolysis; plasma glucose decreased compared to acidosis (P less than 0.01). The data demonstrate that acute metabolic acidosis and alkalosis, as they occur in clinical conditions, influence protein breakdown, and in the opposite direction, lipolysis.
OBJECTIVE: To identify valvar heart disease in patients with chronic uraemia by conventional and colour coded Doppler echocardiography. DESIGN: Case series of an unselected group of 62 patients with end stage renal failure. SETTING: Centre for haemodialysis in a referral hospital in Switzerland. PATIENTS: 62 patients on chronic haemodialysis. MAIN OUTCOME MEASURES: Frequency of structural and functional valve abnormalities and their relation to clinical findings. RESULTS: Structural changes were seen in 40 (64%) of 62 patients after 50 months (range 3-178 months) on haemodialysis. The mitral annulus and aortic cusps were thickened in 25 (40%) and in 34 (55%) patients respectively. Aortic stenosis was present in eight (mean (SD) age 60.5 (8.5) years), with a maximal instantaneous pressure gradient of 41 (14) mm Hg. Aortic regurgitation was seen in eight, mitral regurgitation in seven, and mitral stenosis in three patients. Patients with aortic stenosis had been on haemodialysis for significantly longer than the remaining patients (101 (43) v 46 (43) months, p = 0.01) and had significantly higher concentrations of serum alkaline phosphatase (176 (89) v 117 (47) IU/l, p less than 0.01) and of parathyroid hormone (54 (66) v 19 (29) ng/ml, p less than 0.02). CONCLUSIONS: Patients on long-term haemodialysis had an increased frequency of haemodynamically relevant changes in the aortic and mitral valves. The degenerative valve disease may be related in part to the duration of haemodialysis and to alterations in calcium metabolism as indicated by increased plasma concentrations of alkaline phosphatase and parathyroid hormone.
The course of left ventricular hypertrophy was investigated in anemic hemodialysis patients treated with recombinant human erythropoietin (r-huEPO). 12 patients, aged 60.8 +/- 9.9 years (mean +/- SD) were treated for 18.8 +/- 2.7 months. Left ventricular size was estimated by echocardiography performed before treatment and at least 12 months after relieving anemia. Patients had signs of left ventricular and/or asymmetric septal hypertrophy when compared with a nonanemic and normotensive control group matched for sex and age. At baseline, hemoglobin (Hb) was 8.6 +/- 0.7 g/dl; interventricular septum thickness (IVST) was 1.75 +/- 0.34 cm, left ventricular posterior wall thickness (LVPWT) 1.32 +/- 0.19 cm, left ventricular muscle mass index (LVMI) 222.7 +/- 41 g/m2 and blood pressure (BP) 146.4 +/- 10/81.6 +/- 6 mm Hg. Hb rose to 11.4 +/- 1.2 g/dl (p less than 0.001); IVST and LVMI decreased to 1.42 +/- 0.35 cm (p less than 0.02) and 155.4 +/- 25.1 g/m2 (p less than 0.001); LVPWT and BP remained unchanged (1.30 +/- 0.26 cm and 146.8 +/- 16.9/81.2 +/- 7.8 mm Hg) at the end of the study. During the observation period, two groups of 5 and 7 patients differed from each other. The group of 5 patients had higher BP values (158.9 +/- 9.8/86.5 +/- 5.3 vs. 140.0 +/- 9.5/79.2 +/- 6.8 mm Hg, p less than 0.01), and the period with Hb values above 10 g/dl was shorter (14.5 +/- 2.4 vs. 17.8 +/- 2.4 months, p less than 0.05). These 5 patients failed to show a significant decrease in IVST and LVMI.(ABSTRACT TRUNCATED AT 250 WORDS)
This report describes the case of a 24-year-old female heroin addict with large tricuspid valve vegetation, recurrent septic pulmonary emboli, and renal failure, due to immune-complex nephritis. The clinical course was initially complicated by acute hepatitis A. Because of recurrent emboli and persistent fever despite adequate antibiotic therapy she underwent excision of the vegetation ("vegetectomy") and tricuspid valvuloplasty. She was well at follow-up 12 months later with trivial tricuspid regurgitation shown by doppler-echocardiography. Kidney and liver function were normal. Right-heart endocarditis in drug addiction and therapeutic approaches are discussed. In selected cases "vegetectomy" and valvuloplasty offer a promising therapeutic alternative.
Thirty-six adult type 1 diabetics, whose metabolic control was unsatisfactory on conventional insulin treatment or on continuous subcutaneous insulin infusion, were treated for an average of 13 months by the basis-bolus insulin regimen using pen-like insulin injectors. HbAlc-values improved from 8.1% before to 6.7% at the end of the observation period, with the same daily injected amount of insulin (39 +/- 2 IU/d before, 38.7 +/- 2 IU/d after switching to the new regimen). The number of hypoglycemic events did not increase with the new insulin regimen. Acceptability was good. Flexibility as to the timing of meals and easy handling of the device were considered the main advantages of the new system. Some patients were bothered by the need for intensified self-monitoring of blood glucose. The insulin regimen according to the basis-bolus principle using pen-like injectors led to an improvement of both metabolic control of the patients and their quality of life. It is, however, mandatory that they are properly instructed and willing to perform regular home monitoring of blood glucose.
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To assess the interaction of the two major stress hormones epinephrine and cortisol in the regulation of leucine kinetics in man, epinephrine (50 ng/kg/min) was infused either alone or in combination with cortisol (2 micrograms/kg/min) into two groups of 6 postabsorptive normal male subjects during 180 min. Plasma leucine concentrations decreased by 28% (p less than 0.05) from baseline during epinephrine treatment (plasma levels 515 pg/ml); this was due to a decrease of leucine appearance (determined by 1-13C-leucine infusions) by 23% (p less than 0.025); leucine oxidation decreased by 29% (p less than 0.05). However, when plasma cortisol concentrations were elevated to supraphysiological levels (16.3 mumol/l) during epinephrine administration, the decreases of leucine plasma concentrations, appearance and oxidation were abolished. Plasma glucose and FFA concentrations were similarly elevated during both kinds of treatment. Since leucine appearance represents a measurement of total body protein breakdown and leucine disappearance into non-oxidative pathways reflects protein synthesis, the data indicate that plasma epinephrine concentrations during severe stress exert a protein anabolic effect in man which may counteract catabolic properties of elevated plasma cortisol.
The influence of orally administered ascorbic acid on the urinary pH of 10 healthy volunteers and 10 patients with infected urine was investigated. During a four-day period of investigation urinary pH and the concentration of ascorbic acid in the respective urines were measured five times a day. On the second and third day three times a dose of 2 g ascorbic acid was given, while the diet was under control all four days. A correlation between pH decrease and ascorbic acid concentration is only observed if the concentration of the latter is higher than 200 mg%. The mean decrease in urinary pH between days with ascorbic acid supply and days without is -0,16 pH units for the volunteers respectively -0,18 pH units for the patients. Therefore, vitamin C can not be recommended to lower the pH of alkaline urines.
Patients receiving cytoreductive therapy and bone marrow transplantation (BMT) are known to develop marked protein catabolism. To assess the contribution of whole body protein breakdown, amino acid oxidation and incorporation into proteins, plasma leucine kinetics (1-13C-leucine infusion technique) were determined in six patients five times within 14 days before and after cytoreductive therapy (Cyclophosphamide and total body irradiation) and marrow transplantation. Nitrogen balance became negative (-0.20 +/- 0.04 g/Kg/24 hr) after cyclophosphamide (p less than 0.01) and was -0.25 +/- 0.05 g/Kg/24 hr 7 days after BMT in spite of total parenteral nutrition. Plasma leucine concentration increased after BMT by 67% (p less than 0.0015). Leucine plasma appearance was 1.20 +/- 0.15 mumol/kg/min before treatment, it increased slightly and transiently after cyclophosphamide, and increased again from day 5 to day 7 after BMT (p less than 0.01), suggesting increased protein break-down. Leucine oxidation increased from 0.27 +/- 0.07 before therapy to 0.97 +/- 0.16 mumol/kg/min (p less than 0.02) after cyclophosphamide and BMT. Nonoxidative leucine disappearance rate decreased slightly from 0.92 +/- 0.08 to 0.75 +/- 0.16 mumol/kg/min after BMT (ns). Leucine metabolic clearance rate decreased from 11.8 +/- 1.65 before therapy to 6.9 +/- 0.70 ml/kg/min (p less than 0.02) after cytoreductive therapy. After BMT it increased again to 9.9 +/- 1.5 ml/kg/min (p less than 0.02). The results demonstrate that patients undergoing cytoreductive therapy and bone marrow transplantation develop negative nitrogen balance due to increased protein breakdown associated with increased leucine oxidation and increased metabolic clearance rate.(ABSTRACT TRUNCATED AT 250 WORDS)