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Biomedical subjects

A Senning

Publications and source records attributed to A Senning.

At least 73 records · Page 4Linked to original sources
PubMed1982

Secondary acrylamides in Nyloprint printing plate as a source of contact dermatitis.

Several chemically pure fractions have been isolated from Nyloprint printing plates. 5 of the fractions elicited positive patch test reactions in 7 Nylonprint allergic printers. 4 of the 5 components were analysed by means of nuclear magnetic resonance, infrared spectrophotometry, mass spectrometry and elemental analysis. The fractions were identified as N,N'-methylene-bis-acrylamide. N,N'-[oxybis(methylene)]bis-2-propenamide, N,N'-[1,2-ethanediylbis(oxymethylene)]-2-propenamide, and a new compound N-[(2-hydroxyethoxy)-methyl]-2-propenamide. All of the analysed fractions have the common feature of being secondary acrylamides.

Acrylamides↗
PubMed1982

[Surgery in hypertrophic obstructive cardiomyopathy].

The goal of surgical treatment in hypertrophic obstructive cardiomyopathy is the elimination of the obstruction in the left ventricular outflow tract. 64 operations were performed in 63 patients with HOCM and there was 1 perioperative death. All patients, except 5, were symptomatically improved; the extent of symptomatic improvement was positively related to the completeness of relief of the subvalvular stenosis. During the first 5 years after the operation, 20% of the patients experienced reappearance of symptoms, during later follow-up symptomatic deterioration seemed to occur at an even higher rate. Preoperative left and right heart failure was improved in 3 out of 5 patients; this complication occurred in 4 other patients during the late postoperative follow-up. Congestive heart failure was the cause of late death in 5 patients, 3 died suddenly and 1 each of myocardial infarction or arrhythmia. The 15-years, actuarial survival rate is 63% corresponding to the total yearly mortality of 2.6%. The operation improves symptoms, hemodynamics and some of the complications of HOCM. However, surgery does not cure the disease, and it cannot be decided yet whether or not it slows down the progression of this condition. Transventricular and combined transventricular and transaortic myectomy was more efficient for relieving the subaortic stenosis than the purely transaortic approach. A-V block was more frequent after the transventricular approach, and aortic incompetence occurred more often after transaortic myectomy; these complications did not increase the postoperative mortality. A clear effect of the different surgical methods on the long-term results cannot yet be established. Operative indications are reviewed in the light of the presented experiences.

Adolescent↗
PubMed1981

[Budd-Chiari syndrome: a contribution to surgical therapy].

The commonest cause of Budd-Chiari syndrome is stenosis of the inferior vena cava and hepatic veins. Improved venous draining can be achieved by resection of a dorso-cranial portion of the liver and the anterior aspect of the vena cava wall. A complex case is reported.

Adolescent↗
PubMed1981

[Early results of percutaneous transluminal coronary vessel dilatation in single vessel disease. Comparison with drug treated or surgically treated patients, retrospective for dilatation suited patients].

The shortterm results (mean follow-up 0.9 years) in 61 patients with single vessel disease (1-VD) who had undergone percutaneous transluminal coronary angioplasty (PTCA) were compared with those in 33 patients with 1-VD treated medically and in 36 patients with 1-VD treated by bypass surgery. All medically and surgically treated patients had coronary artery stenoses which were classified in a retrospective analysis as suitable for PTCA. Initially there were no significant differences between the three groups with respect to functional impairment (NYHA class), incidence of prior myocardial infarction, left ventricular ejection fraction and localization of the coronary stenoses. Comparison of follow-up results at the end of the first year showed (1) that the NYHA class was reduced to a similar extent both in patients treated surgically and in those treated by PTCA, (2) that the NYHA class in the medically treated group was significantly greater than in the other two groups, and (3), that there was no difference among the three groups with respect to infarct and mortality rate.

Coronary Artery Bypass↗
PubMed1981

[The left ventricular function in bicycle ergometric stress before and after aortocoronary bypass surgery].

Biplane left ventricular cineangiograms and pressure measurements were performed in 44 patients with coronary heart disease at rest and during submaximal or symptom-limited supine bicycle exercise before and 7 +/- 3 months after bypass surgery. Revascularization was complete in 12 (group 1) and incomplete in 32 patients (group II). Preoperative left ventricular ejection fraction (EF) was within normal limits at rest and declined during exercise in both groups (group I from 59 to 51%, p less than 0.01; group II from 61 to 48%, p less than 0.001). Postoperative EF at rest was nearly identical to preoperative EF in both groups and remained unchanged during exercise (group I from 65 to 63%; group II from 58 to 56%). Peak systolic pressure to end-systolic volume index ratio (LVSP/ESVI in mm Hg/ml . m-2) also decreased during exercise in both groups peroperatively (group I from 3.7 to 3.2 [n.s.]; group Ii from 3.4 to 2.6, p less than 0.005). Postoperative LVSP/ESVI at rest was again unchanged as compared to preoperative LVSP/ESVI. During exercise, however, it increased in both groups, reaching higher values in group I than in group II (5.1 vs. 3.7, p less than 0.05). Whereas both parameters indicate improvement of global left ventricular function following surgery, LVSP/ESVI also suggests more marked recovery of function in patients with complete revascularization than in those where revascularization is incomplete.

Adult↗
PubMed1981

An experimental study on transannular patching of the right ventricular outflow tract with and without a pulmonary valve monocusp mechanism.

The efficacy of a pericardial patch in the right ventricular outflow tract (RVOT) with a monocusp valve mechanism was investigated experimentally. Hemodynamic performance of the right ventricle and angiographic competence of the valve were compared in animals after patching of the RVOT and removal of the pulmonary valve (group I), patching of the RVOT, removal of the pulmonary valve and implantation of a monocusp valve (group II), patching of the RVOT, partial removal of the pulmonary valve and implantation of a monocusp valve (group III) and a control group (IV). Postoperative effective right ventricular cardiac index, stroke volume and stroke work improved significantly from group I to III, but did not reach the control values of group IV. Angiographically the monocusp valve allowed some early diastolic regurgitation due to late closure (group II) if it was not supported by remnants of the animal's own pulmonary valve (group III).

Animals↗
PubMed1981

Left ventricular function during exercise before and after bypass surgery.

Biplane left ventricular cineangiograms and pressure measurements were performed in 44 patients with coronary heart disease at rest and during submaximal or symptom-limited supine bicycle exercise before and 7 +/- 3 months after bypass surgery. Revascularization was complete in 12 (group I) and incomplete in 32 patients (group II). Preoperative left ventricular ejection fraction (EF) was within normal limits at rest and declined similarly during exercise in both groups (group I from 59 to 51%, p less than 0.01; group II from 61 to 48%, p less than 0.001). Postoperative EF at rest was nearly identical to preoperative EF in both groups (group I, 65%; group II, 58%) and remained unchanged during exercise (group I, 63%; group II, 56%). Peak systolic pressure to end-systolic volume index ratio (LVSP/ESVI in mm Hg/ml . m-2) also decreased during exercise in both groups preoperatively (group I from 3.7 to 3.2, NS; group II from 3.4 to 2.6, p less than 0.005). Postoperative LVSP/ESVI at rest was again unchanged as compared to preoperative LVSP/ESVI. During exercise, however, it increased in both groups reaching higher values in patients of group I than of group II (5.1 versus 3.7, p less than 0.05). Whereas both parameters indicate an improvement in global left ventricular function following surgery, LVSP/ESVI even suggests a more sizable recovery of function in patients with complete as compared to those with incomplete revascularization.

Adult↗
PubMed1980

N-Nitrosodiethanolamine revisited.

N-nitrosodiethanolamine is believed to be a weakly carcinogenic chemical, and as it occurs widely--in consumer products for example--it may constitute a significant hazard to humans. However, the chemical evidence concerning the identity, purity and properties of N-nitrosodiethanolamine is incomplete, and this casts some doubt on the basis of the current interest in this substance. In the present paper a purification procedure of synthetic N-nitrosodiethanolamine based on high-performance liquid chromatography is given. Other fractionation procedures such as gas liquid chromatography, ambient pressure column chromatography and distillation are shown to be inadequate. The purity and identity of purified N-nitrosodiethanolamine is established by means of electron impact and field ionization mass spectrometry, including metastable defocusing and collision induced decomposition techniques. Furthermore, 1H and 13C nuclear magnetic resonance and, to a lesser extent, infrared and ultraviolet spectroscopy are used. Deuterium labelled analogues of N-nitrosodiethanolamine and the parent diethanolamine are employed in rationalizing the results obtained.

Carcinogens↗
PubMed1980

[Long-term follow-up of patients asymptomatic and expanding abdominal aortic aneurysms (author's transl)].

In a retrospective study, 268 patients with all three types of abdominal aortic aneurysms (AAA) were analyzed. They had been seen at the Surgical Clinic A of the University Hospital in Zurich, Switzerland, from 1961 through 1977. The follow-up included 97% of the surgical and all nonsurgical cases. This report is based on the analysis of the 167 surgically and 16 nonsurgically treated patients with asymptomatic (I) or expanding (II) AAA. Of the 16 patients not operated on, 15 died after a mean time of 13 months after examination, 57% due to rupture and 29% because of coronary heart disease. In the operative group, the 30-day perioperative mortality was 7% for the asymptomatic AAA and 14% for the expanding. Late mortality reached 25% for type I and 37% for type II after a mean survival time of 50 months. Of all surgically treated patients, 58% could be examined 1-14 (mean 4) years after aneurysmectomy. The cumulative survival rate for the 5th year reached 73% in the surgical asymptomatic group and 48% in the expanding or 62% for both; the nonsurgical group had a survival rate of only 6%. The results of the long-term follow-up are described in detail as well as the various factors related to arteriosclerosis or to surgery with statistically significant influence on prognosis. Comparison of the late results of all three types of AAA and confrontation with the spontaneous course of the disease emphasize the importance of early indication for operation.

Aorta, Abdominal↗
PubMed1980

Reoperations after valvular heart surgery: indications and late results.

The incidence of reoperations after valvular heart surgery was higher after valve-preserving procedures and after valve replacement with biological prostheses than after implantation of mechanical prostheses. The indication for reoperation was elective in the vast majority of cases; usually it was due to progressive late deterioration of repaired valves or of tissue valves. Symptoms are not a sensitive indicator in timing the reintervention. Progression of clinical signs, radiological and ECG alterations and echocardiographic criteria must be followed closely once late deterioration has been diagnosed. Criteria for reoperation are basically the same as for primary valve surgery. Hemolytic anemia and recurrent emboli were rare indications for reoperation in the presented material. Paravalvular leak was the most frequent indication for reoperation following the implantation of mechanical heart valve prostheses. A number of valve-related complications requiring emergency reoperations are presented; immediate recognition of these conditons and immediat intervention are mandatory. Bacterial endocarditis remains a severe complication after valvular heart surgery and threatens patients with mechanical prostheses in particular. The late results of reoperations depend mainly upon the state of disease reached by the time of reintervention, i.e., upon the right timing of the reoperation.

Adult↗
PubMed1980

Congenitally corrected transposition of the great arteries: a clinical and surgical study.

From 1967 to 1979, 40 patients with the diagnosis of congenitally corrected transposition of the great arteries (C-TGA) have been followed. Associated cardiac defects were present in all but one patient, most frequently ventricular septal defect (80%), and pulmonary stenosis (70%). Left sided atrio-ventricular valve dysfunction developed in 25%, third degree atrio-ventricular block (at least intermittently) in 33% of the patients. Twenty-eight patients were operated: palliative procedures were done in 6, corrective operations in 22 patients. Ten of the 40 patients have died during a mean observation period of 4 years: 4 early postoperatively, 3 late postoperatively and 3 non-operated patients. Sudden unexplained cardiac arrest has been the most frequent cause of death (2 late postoperative and 2 non-operated patients). The incidence of residual ventricular septal defects and residual pulmonary stenosis after corrective surgery has been relatively high owing to the complex anatomy in these patients. Also reconstruction of the atrio-ventricular valves has been difficult because of severe deformities, particularly of the left side. It is concluded that in C-TGA the pacemaker should be implanted early, at the first sign of AV-conduction disturbance. Since the relief of the pulmonary stenosis is difficult, the operation should be deferred until an adequate-sized conduit can be implanted.

Adolescent↗