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Biomedical subjects

R Schuster

Publications and source records attributed to R Schuster.

At least 127 records · Page 7Linked to original sources
PubMed1987

Influence of infusion of deoxycorticosterone acetate on the responses of kidney function elicited by stimulation of the peripheral arterial chemoreceptors with almitrine bismesylate in anaesthetized rats.

In two groups of male, normotensive, spontaneously breathing rats in chloralose-urethane anaesthesia the peripheral arterial chemoreceptors were stimulated by intravenous infusion of almitrine bismesylate (0.25 mg/kg). The experiments were carried out in moderate osmotic diuresis. In one series desoxycorticosterone acetate (DOCA) was infused at a rate of 35-40 ng/min.100 g body weight. Urine was collected via a bladder catheter. Kidney hemodynamics as well as tubular and excretory function were determined using the clearance-technique. In both groups of animals administration of almitrine caused an increase of breathing rate as well as an increase of the oxygen tensions and the pH-values in the arterial blood. Mean systemic arterial blood pressure, effective renal plasma flow and glomerular filtration rate decreased slowly with the time of the experiments, whereas renal hemodynamic resistance tended to increase both in the control and in the DOCA treated group. In both groups of animals intravenous infusion of almitrine was followed by an inhibition of renal tubular sodium reabsorption and an increase of both the absolute and the fractional salt excretion. The data indicate that arterial chemoreceptor stimulation in rats causes an inhibition of renal tubular sodium reabsorption which does not result from a reduced tubular action of mineralocorticoid hormones.

Almitrine↗
PubMed1987

Renal hemodynamics and excretory function of healthy young men during stimulation of their peripheral arterial chemoreceptors by almitrine bismesylate.

Renal hemodynamics and excretory function were studied using clearance-techniques in 13 healthy, normotensive, normoxic young men undergoing moderate osmotic diuresis. Each subject was measured in two experiments both lasting from 7:30 a.m. to 6:00 p.m. In one of them 50 mg almitrine bismesylate (Vectarion) was ingested at 12:00 o'clock, whereas the other test served as control. There were only negligible changes of the parameters measured in the control experiments. Immediately after ingestion of the drug a renal vasodilation occurred, but 2-3 h later renal hemodynamic resistance tended to increase. Urinary sodium excretion rose after administration of almitrine. Initially this increase seemed to be caused by the kidney vasodilation but between the 3rd and 6th hour after giving the agent a natriuresis occurred that resulted from inhibition of renal tubular sodium reabsorption. The maximum of this renal tubular response was apparently not reached at the end of the experiments, i.e. 6 h after oral administration of the drug. Almitrine did not increase the renal potassium excretion. The data indicate that pharmacological stimulation of the peripheral arterial chemoreceptors by almitrine bismesylate in normoxic healthy humans causes reflectorically a slight renal vasoconstriction and a long-lasting inhibition of renal tubular sodium reabsorption. These findings are in good agreement with previously published data obtained in animal experiments.

Adult↗
PubMed1987

[Pulmonary alveolar microlithiasis].

Case report from a 12-years old russian girl with pulmonary alveolar microlithiasis. The diagnosis was confirmed by histologic examination from biopsy specimen of the lung. The differential diagnosis and the histomorphology are discussed.

Biopsy↗
PubMed1987

[Oxygen supply and oxygen uptake by skeletal muscle in acute arterial circulatory disorders--an experimental study in the dog].

The oxygen supply and the oxygen uptake of the ischemic skeletal muscle were defined in rest and by loading in experimental studies in dog. About 72% of the supplied arterial oxygen was taken up from the ischemic skeletal muscle in rest in opposite to 84.7% by loading. Therewith the authors found an essential higher value as supposed in literature so far. The absolute value of the oxygen uptake of the normally circulated skeletal muscle with 0.14 ml O2/min/100 g is small in contrast to the highly differentiated parenchymatous organs. An adaptation to an anaerobic metabolism is assumed by the authors in case of falling below the critical boundary value of 0.1 ml O2/min/100 g in skeletal muscle.

Animals↗
PubMed1986

[Radiologic alternatives of splenectomy].

Partial peripheral splenic embolization can be performed in case of incurable thrombocytopenia due to hypersplenism without following splenectomy. A combined proximal and peripheral splenic embolization should only be carried out immediately prior to splenectomy if complications of hemorrhage due to extreme splenomegaly are to be expected. An only proximally performed occlusion can be by-bassed by collaterals. Anatomic blood vessel variations, techniques and complications are discussed in 6 cases.

Combined Modality Therapy↗
PubMed1986

[pH measurement in tissue--a reliable criterion for the registration of acute arterial circulatory disorder in animal experiments].

An arterial ischemia was carried out step by step in the right pelvic extremity of the dog. The ph level was measured continuously in the lateral vastus of the femoris muscle on both sides by means of a glass-one-rod measuring equipment. The pH value decreased to 6.43 ninety minutes after a total interruption of the arterial circulation. The initial value amounted to 7.20. The tissue-pH-values increase quickly during the following phase of recirculation.

Animals↗
PubMed1985

Chemical-shift-selective magnetic-resonance imaging of avascular necrosis of the femoral head.

Chemical-shift-selective (CHESS) nuclear-magnetic-resonance (NMR) imaging is a new method for separating "water" and "fat" (CH2) resonances in proton NMR imaging. Its major advantage over conventional composite NMR imaging is the contrast enhancement, which in particular allows the detection of small water-containing structures, such as vessels or joint surfaces, normally obscured by fat signals. First clinical findings in the femoral head with avascular necrosis are reported.

Adipose Tissue↗
PubMed1985

Bilateral virilizing adrenal tumor in a 17 year old woman.

We report on a 17 year old female patient with amenorrhea, hirsutism and slight acne. Hormonal blood analyses showed markedly increased levels for dehydroepiandrosteronesulfate, testosterone and androstenedione. Ultrasound investigation revealed a large tumor above the left kidney and a small area above the right kidney, suspicious for a tumor on the contralateral side. This was confirmed by angiography. During surgery, bilateral tumors were removed. Pathological diagnosis was made as bilateral adenomas of the adrenal cortex. Postoperatively, an impressive normalization was observed, accompanied by a rapid decrease of the elevated hormone concentrations. This case is the first report of a bilateral occurrence of a virilizing tumor of the adrenal cortex.

Adenoma↗
PubMed1985

[Value of computer tomography in bronchopulmonary diseases in childhood].

In 20 children with bronchopulmonary symptoms and striking x-ray-thorax-findings computer-tomography examinations were carried out in addition to the usual diagnosis. Mediastinal demand for room and screening for tumor are recognized as essential indications in infancy for the application of CT-diagnosis in the chest. Computerized tomography is also indicated if an anomaly of blood vessels is suspected. In all other pulmonal diseases CT gives valuable information but in no case it replaces a bronchologic examination.

Adolescent↗
PubMed1984

[Is routine bone scanning justified during the after-care for breast cancer?].

In a retrospective study of 254 women with carcinoma of the breast (mean age 55.4 years) the occurrence of bone pain was compared with results of skeletal scanning, skeletal X-ray examinations and routine biochemical findings. Typical signs of skeletal metastases were found in bone scans of 119 patients, 88 (74%) of whom had bone pain. Alkaline phosphatase was elevated in 54 (45%), LDH in 32 (27%), and gamma-GT in 69 patients (58%). There was a statistical correlation between the number of affected skeletal parts and the absolute level of alkaline phosphatase (P less than 0.001) and of LDH (P less than 0.05). Skeletal scans gave no evidence of bone metastases in 36 patients who had bone pains. In this group of patients alkaline phosphatase was elevated in 4, LDH in 1 and gamma-GT in 12 patients. Routine scanning of 254 patients revealed skeletal metastases in 12% without any clinical symptoms. Bone pain and (or) increased activity of alkaline phosphatase occurred in 91% of patients with skeletal metastases. In our view, bone scan in the postoperative control of breast cancer is justified only after onset of clinical symptoms and (or) if there is an abnormally raised alkaline phosphatase activity.

Adult↗
PubMed1984

[Determination of left atrial size. Comparison between echocardiographic and radiological determination].

The size of the left atrium was determined echocardiographically and radiologically in 66 patients with mitral valve disease, grade I-IV (New York Heart Association classification). Angiocardiography served as the reference. The echocardiographic determination was both by M-mode and two-dimensional, the radiological one was from the postero-anterior films (after Higgins), as well as from the lateral pictures. There was good agreement between the two echocardiographic methods and a good correlation of the two with cine-angiographic measurements (r = 0.82-0.99; P less than 0.001). But there was a poorer, although still statistically significant correlation of the radiologically determined atrial size with the echocardiographic and angiocardiographic measurements (r = 0.47-0.56; P less than 0.001). Thus M-mode and two-dimensional echocardiography is the more sensitive method for determining the size of the left atrium.

Adult↗
PubMed1984

[Mitoxantrone in the primary treatment of metastasizing breast cancer].

25 females (57.7 +/- 11.1 years) and 1 male (71 years) with histologically verified metastasizing breast cancer were submitted to mitoxantrone therapy. Secondary tumours were found in following organ systems: bone: 19 cases; lung: 13 cases; liver: 6 cases; skin: 5 cases; locoregional and nodal: 5 cases; brain: 1 case. All patients showed normal bone marrow and heart function before commencement of treatment. Mitoxantrone was given in form of a 30-minute infusion at a dosage of 14 mg/m2. In 4 patients dosage was increased to 20 mg/m2. Treatment cycles were repeated every 3 weeks according to peripheral blood counts. All patients were cardiologically monitored throughout the study by means of electrocardiogram, systolic time interval measurement and radionuclide angiography. The mean observation period was 169 +/- 98 days. The response of the patients was as follows: 1 complete remission, 5 partial remissions, 4 unchanged disease and 16 progressive disease. Side effects were normally mild; only nausea, leucopenia and moderate hair loss were of clinical relevance. Cardiac decompensation was not observed. No significant electrocardiographic alterations were found throughout the study. Results of systolic time interval measurements (PEPI, PEP:LVET) and radionuclide angiography (LVEF) gave evidence of moderate depression of heart function. In view of the optimal benefit/risk ratio of mitoxantrone this drug could be used in combined modality treatment schedules in metastasizing breast cancer.

Aged↗