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Biomedical subjects

P Dittrich

Publications and source records attributed to P Dittrich.

At least 55 records · Page 3Linked to original sources
PubMed1989

Increase in Hb-O2-affinity at moderate altitude (2000 m) in patients on maintenance hemodialysis.

Oxygen transport by erythrocytes was studied in eight patients on maintenance hemodialysis before, during and after a 2-week stay at an altitude of 2000 m. Dialysis was continued at that altitude. In all tests, blood samples were collected one or two days following hemodialysis. Pre-altitude tests: The patients exhibited anemia (hemoglobin concentration, Hb = 97.4 +/- 17 g/l). Due to an elevated red cell 2,3-diphosphoglycerate concentration (2,3-DPG) and mild metabolic acidosis, elevated standard and in vivo P50 values (pO2 at 50% oxygen saturation of hemoglobin, sO2) were measured. Altitude: Upon ascent, arterial pO2 decreased from 82 +/- 4 torr to about 60 torr, sO2 was lowered by 5%. After 2 weeks sojourn, pO2 and sO2 increased towards normal values. In contrast to healthy subjects, dialysis patients developed respiratory alkalosis (blood pH: +0.074) upon ascent. This caused a significant shift to the left of the oxygen dissociation curve (ODC), indicated by lowered in vivo P50-values (P50,vv,-2 torr). Red cell 2,3-DPG, P50,st (P50 at a blood pH = 7.4 and pCO2 = 40 torr), hemoglobin concentration and hematocrit showed a high day-to-day variability and did not change because of the altitude exposure. We interpret the increase of the oxygen affinity of hemoglobin in patients with renal anemia as beneficial, as it favors oxygen loading of hemoglobin in the lung during exposure to a hypoxic environment.

2,3-Diphosphoglycerate↗
PubMed1988

The cDNA sequence of the 69-kDa subunit of the carrot vacuolar H+-ATPase. Homology to the beta-chain of F0F1-ATPases.

Vacuolar ATPases constitute a novel class of N-ethylmaleimide- and nitrate-sensitive proton pumps associated with the endomembrane system of eukaryotic cells. They resemble F0F1-ATPases in that they are large multimeric proteins, 400-500 kDa, composed of three to nine different subunits. Previous studies have indicated that the active site is located on the approximately 70-kDa subunit. Using antibodies to the approximately 70-kDa subunit of corn to screen a carrot root lambda gt11 cDNA library, we have isolated cDNA clones of the carrot 69-kDa subunit. The complete primary structure of the 69-kDa subunit was then determined from the nucleotide sequence of its cDNA. The 69-kDa subunit consists of 623 amino acids (Mr 68,835), with no obvious membrane-spanning regions. The carrot cDNA sequence was over 70% homologous with exons of a Neurospora 69-kDa genomic clone. The protein sequence of the carrot 69-kDa subunit also exhibited 34.3% identity to four representative F0F1-ATPase beta-chains over a 275-amino-acid core stretch of similar sequence. Alignment studies revealed several regions which were highly homologous to beta-chains, including sequences previously implicated in catalytic function. This provides definitive evidence that the vacuolar ATPase is closely related to the F0F1-type ATPases. A major functional difference between the 69-kDa and beta-subunits is the location of 3 critical cysteine residues: two in the putative catalytic region (Cys-248 and Cys-256) and one in the proposed Mg2+-binding site (Cys-279). These cysteines (and two others) probably account for the sensitivity of the vacuolar H+-ATPase to the sulfhydryl reagent, N-ethylmaleimide. It is proposed that the two ATPases may have arisen from a common ancestor by the insertion or deletion of a large stretch of nonhomologous sequence near the amino-terminal end of the subunit.

Amino Acid Sequence↗
PubMed1987

[Clinical and paraclinical findings on status following prosthetic heart valve replacement with special reference to the behavior of pulmonary pressure].

Retrospectively were evaluated clinical findings of 151 patients with condition after replacement of artificial cardiac valves (Björk-Shiley), who were treated in our department of cardiology in 1986. The patients with mitral valve replacement (MVR) and mitral valve and aortic valve replacement showed the highest rate of individualisation in comparison to aortic valve replacement. 18 patients showed complications and acute deteriorations, respectively, two of which had a fatal course. In 53 patients the bicycle-ergometric exercises were performed with measurement of the pulmonary pressure. Of these patients the majority indeed subjectively improved in their behaviour, however, the objective exercise tolerance was altogether low and the rate of invalidisation increased in comparison to the preoperative rate. The pulmonary pressure at rest in the majority of the patients was reduced mostly in dependence on the initial values. Increases appeared only sporadically. Under exercise, however, particularly the patients with mitral valve replacement showed pathological increases of pressure. Altogether the best results showed patients with aortic valve replacement also with regard to the shrinking of the radiologically established size of the heart.

Adolescent↗
PubMed1987

[Clinical aspects, diagnosis, therapy and course of unstable angina pectoris].

It is reported on 27 patients aged 32-77 years with an unstable angina pectoris, including coronary spasm. All patients showed an anamnesis of less than 3 months, nearly the half of less than 24 hours. The resting electrocardiogram during the attack was pathological in 22 patients, 7 patients showed a Prinzmetal reaction and 11 patients showed intermittent ventricular dysrhythmias. The exercise electrocardiogram in the stable phase was pathological in 16 of 17 patients. Of 23 patients who underwent a selective coronary angiography with laevocardiography 9 patients each showed a disease of one vessel and three vessels, respectively, and 5 patients a disease of two vessels. Only nearly 50% of the patients could be stabilized medicamentously (nitrates, calcium antagonists, rarely beta-blockers). In three patients still during the unstable phase a surgical revascularization was carried out, in 11 patients after stabilization. Five patients suffered an early infarction; one of them died. Altogether, the unstable angina pectoris is even nowadays to be regarded as a clinical picture with a relatively bad prognosis, which demands rapid action.

Adult↗
PubMed1987

[Mechanocardiography findings and hypertrophic and dilated cardiomyopathy].

On 71 patients with hypertrophic cardiomyopathy with and without measurable left-ventricular outflow tract gradients, with typical and atypical morphology (ascertained by catherisation of the right and the left heart and angiocardiography as well as selective coronarography) as well as also by catheter investigation including the cardiography of ascertained dilatative cardiomyopathy in 19 patients mechanocardiographic (systolic time analysis from the carotid sphygmogram as well as parameters of the diastole from the apex cardiogram) investigations concerning the heart function and the course were performed. The hypertrophic cardiomyopathy is characterized particularly by a restricted diastolic function, when a good or very good pumping function is present. On the basis of the mechanography the dilatative cardiomyography particularly shows a bad pumping function with also restricted diastolic function. The two forms of cardiomyopathy are clearly to be separated by means of the methods used. Prognostic statements are possible only with reservation. Apexcardiographic parameters are here better suitable.

Adolescent↗
PubMed1987

Improved management of congestive heart failure. Use of continuous ambulatory peritoneal dialysis.

Four patients suffering from end-stage congestive heart failure (CHF) refractory to conventional medical treatment were treated with continuous ambulatory peritoneal dialysis (CAPD) for one to 21 months. All four patients improved from class IV CHF to class II, as defined by the New York Heart Association, and experienced a definite improvement in their sense of well-being. Three patients, women between 42 and 59 years of age with contraindications for heart transplantation, were all professionally rehabilitated. One 21-year-old patient received CAPD until he underwent a successful orthotopic heart transplantation. We thus propose CAPD as an effective treatment for end-stage CHF refractory to conventional medical treatment.

Adult↗
PubMed1987

Traumatic renal artery occlusion: is late reconstruction advisable?

We report a case of traumatic renal artery occlusion treated successfully by reconstruction several years after the injury. Hypertension resulted in diagnostic investigation by means of excretory urography, computerized tomography, angiography and perfusion scintigraphy. Treatment consisted of a thin-walled polytetrafluoroethylene (Gore-Tex) bypass between the aorta and left renal artery near the hilus. When the patient was discharged from the hospital the creatinine level was normal and blood pressure was 180/90.

Adult↗
PubMed1986

Spontaneous and forced cutaneous absorption of indomethacin in pigs and humans.

Indomethacin can permeate the normal skin of laboratory animals as well as humans, therefore, we investigated whether and what extent this process may be intensified by sonophoresis or iontophoresis. To 6 pigs Amuno-Gel (MSD Sharp & Dohme) (indocid gel) containing 1% indomethacin was applied over 5 h iontophoretically through the skin of the back, and the blood and urine concentrations were measured by high performance liquid chromatography with inline post column hydrolysis and fluorimetric detection. Nonassisted skin uptake was measured 1 to 2 weeks later in the same animals each serving as its own control. Iontophoresis (0.1 mA/cm2) increased maximum indomethacin levels from 32 (controls) to 82 ng/ml and urinary excretion over 5 h from 29.4 to 181.1 ng/cm2 of treated skin area. Sonophoresis did not improve indomethacin absorption. In 7 human volunteers, iontophoretic application of indomethacin over 1 h onto the skin of the back (1380 cm2 surface area) increased maximum plasma levels from 43 ng/ml (controls) to 221 ng/ml, and the urinary excretion over a total of 5 h from 18.1 (controls) to 97.6 ng/cm2. As calculated from the fraction of indomethacin excreted in the urine, about 0.2 microgram indomethacin/cm2 of treated skin area taken up spontaneously and about 1.0 microgram/cm2 was transported by iontophoresis.

Adult↗
PubMed1985

[Recurrent hemolytic-uremic syndrome with positive immunofluorescence].

The hemolytic uremic syndrome is a disease of infancy, its major clinical manifestations include reversible thrombocytopenia, hemolytic anemia, and renal failure. Although a great number of patients with HUS have been published, relapses as well as positive immunofluorescence studies are rare findings. In our patient the disease began at age of 7 years and recovered completely. At 10 1/2 years a relapse occurred and despite therapy the patient died two months later. Renal biopsy showed severe arterial and glomerular changes with remarkable similarity to the histological findings in thrombotic thrombocytopenic purpura, which could be explained as secondary hypertensive damage, and dense granular deposition of fibrinogen, IgG, IgA, C3, and Clq along the capillary loops of the glomerulus and throughout the wall of the renal arteries. The clinical data, histological findings, and the particularities of our patient with this special course of HUS are discussed.

Child↗
PubMed1985

[HPLC determination of troxerutin in plasma and urine following oral administration in man].

A high-performance liquid chromatographic method (HPLC) is described for the analysis of 3',4',7-tri-O-(beta-hydroxy-ethyl)-rutoside (troxerutin) in human plasma and urine. After separation of interfering substances on XAD-2 trihydroxyethylrutoside is converted to tetrahydroxyethylrutoside by 2-chlorethanol in alkaline medium. After HPLC-separation tetrahydroxyethylrutoside is quantified by fluorescence detection. The pharmacokinetics of troxerutin were measured in plasma after oral administration to man. The relative bioavailability of the drug from Venelbin was 97.8 +/- 37.1% compared to an aqueous standard solution.

Anticoagulants↗
PubMed1984

Pharmacokinetics of indomethacin i.m. in blood, synovial fluid, synovial membrane, muscle, fat, bone, and spinal fluid.

Nonsteroidal anti-inflammatory drugs are an important part of the therapy of rheumatoid arthritis. For optimal dosage it would be necessary to know the levels of such compounds in inflamed tissue and not only in blood because the drugs inhibit prostaglandin synthesis in all cells of the body. In the present study, the levels of indomethacin in blood, synovial fluid, synovial membrane, muscle, fat, bone and spinal fluid of patients with rheumatoid arthritis have been measured at 1, 3, 6, and 12 hours after administration of 50 mg indomethacin (Amuno, Merck Sharp & Dohme). At 3, 6, 9 and 12 hours after administration levels in synovial fluid and tissue were higher than in blood but the differences were not significant. Levels in the other tissues investigated did not differ much from blood. In experiments with carrageenan-induced inflammation in rabbits, levels of indomethacin in blood and exudate have been measured after administration of 7.5 mg/kg i.v. Between 3 and 8 hours after administration levels in exudate were significantly higher than in blood. From the time course of indomethacin in blood compared to synovial fluid or exudate and from the comparison of the elimination half lives it can be concluded, that the transport of indomethacin into the inflamed area is mainly a process of diffusion.

Adipose Tissue↗
PubMed1983

[Pathophysiology of ventricular tachyarrhythmias].

On 11 patients at the age between 11 and 60 years with ventricular tachyarrhythmias (6 times relapsing ventricular tachycardia, twice relapsing ventricular fibrillation, 3 times massive polytopic ventricular extrasystoles) complex intracardiac electrophysiological and haemodynamic examinations, including heart catheterization with angiography (and in 6 patients selective coronarography) were performed. In no case we succeeded in evoking a ventricular tachycardia by stimulation. Also the spontaneous long-lasting ventricular tachycardias could not be interrupted by a single or manifold stimulation. By multiple right- and left-ventricular potential deviations we succeeded in differentiating the ventricular tachycardia and ventricular extrasystoles, respectively, according to the place of origin in all patients. As cause of the ventricular tachycardia and of the ventricular fibrillation, respectively, in 4 patients an ectopic focus with increased impulse formation, in the other patients, apart from an increased ectopic automatism, also reentry tachycardia is assumed.

Action Potentials↗
PubMed1983

[Experiences with continuous ambulatory peritoneal dialysis (CAPD) at the University Clinic for Internal Medicine in Innsbruck].

First described by Popovich et al. in 1978 [7], and modified by Oreopoulos et al. [6], CAPD is accepted as a simple technique which offers chronic dialysis to patients who are either unsuitable for, or noncompliant with, haemodialysis (HD). The technique of CAPD is based on the theoretical basis which predicted that adequate dialysis could be obtained if 10 litres of dialysis fluid per day are allowed to equilibrate with body fluids [5]. In practice, 2 litres of peritoneal dialysis solution are present in the peritoneal cavity, continuously, except for the periods when the patient exchanges the dialysate for fresh solution via a permanent peritoneal catheter [3]. The patient is ambulant and independent of hospital and machine. In our experience, with good technology and careful patient selection CAPD is now a well-established procedure and the preferred method of dialysis for some patients.

Adolescent↗
PubMed1982

[Primary benign intramural intracavitary cardiac tumors--clinical, diagnostic and therapeutic aspects].

10 cases of benign primary tumours of the heart (5 myxomas of the left atrium, 2 myxomas of the right atrium, 1 right-ventricular endothelioma of the endocardium, 1 left-ventricular pseudorhabdomyoma, 1 tumour of the interventricular septum) are described. The diagnostically decisive method was in 5 cases the heart catheterization with angiocardiography, furthermore in one case each the roentgenogram of the thorax, the echocardiography, the histology of embolic material, the operation as well as the autopsy. The echocardiography was available for 4 patients; in one case it was diagnostically decisive, delivered important additional informations in 2 patients and failed in one patient. With increasing propagation of the echocardiography, which in the opinion of the authors at least in all cases should be used before a planned invasive cardiological diagnosis, is to be reckoned with an improvement of the diagnosis of tumours of the heart and with an increase of the chances of a causal, namely the timely cardiosurgical therapy.

Adult↗
PubMed1982

[Hemodynamic examinations concerning the effects of cardiac glycosides in hypertrophic obstructive cardiomyopathy (HOCM)].

Due to fundamental considerations and especially after Braunwald's et al. (1962 (4)) examinations of 5 patients with severe hypertrophic obstructive cardiomyopathy (HOCM) with 0.5-0.75 mg of Ouabain, cardiac glycosides in cases of this disease are to be regarded as contraindicated. Own examinations (right and left-heart catheterizations, monoplane cineangiography of the left ventricle, determination of the cardiac output, and the ejection fraction (EF) were performed in 10 patients with HOCM of different stages. Applying the usual dosage of 0.25-0.375 mg of strophanthin, different hemodynamic effects were observed in discrete forms. In cases with a higher severity, the observations of Braunwald et al. could actually be confirmed. The left ventricular systolic pressure gradients were increased, but cardiac output, left ventricular enddiastolic pressure, pulmonary pressure and resistance, and also arterial pressure and peripheral resistance behaved differently. EF increased slightly. The right infundibular gradients were decreased with one exception, or resp., they were unchanged. Obviously, HOCM reacts especially unfavourably with so-called left-ventricular cavity obliteration. The main importance might belong to the behaviour of the free lumen of the left ventricle. In regard of the principally reserved attitude towards the cardiac glycoside therapy in HOCM, no change has occurred. Only in patients with atrial fibrillation and a rapid heart rate, a therapy trial could be considered, if necessary in combination with beta-blocking agents or calcium antagonists under hemodynamic control. In cases of HOCM with serious obstruction and signs of cardiac failure and inadequate affecting by calcium antagonists, an early surgical intervention should be executed.

Adult↗
PubMed1981

[The natural course of atrial septal defects].

61 patients at the age of 18 to 70 years with untreated atrial septum defect were examined 7.5 to 21 (on the average 10.5) years after the first recognition. Subjective symptomatology, clinical picture, size of the heart, mean pressure of the pulmonary artery and shunt volume at the beginning and at the end of the period of observation were analysed. The results reveal an above all favourable prognosis of the congenital malformation. In a course without complications an age can be reached adequate to the average life-expectance. After the 40th year of age, however, in 75% of the patients complaints appeared or their number increased. With growing age the size of the heart and the frequency of disturbances of the cardiac rhythm increased. In the small left-to right-shunt (less than 30% of the pulmonary flow) in the majority of the cases (85%) the prognosis proved to be good. Even in shunt volumes of more than 60% in half of the patients no essential deterioration developed in the period of observation. No clear relations were found between the mean pressure of the pulmonary artery and the clinical degree of severity. The indication to the operative correction of the atrial septum defect diagnosed only at the adult age demands a critical individual judgement, in which case apart from the haemodynamic parameters anamnesis and clinical findings within a cardiological observation of the course are of particular importance.

Adolescent↗