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Biomedical subjects

U Staedt

Publications and source records attributed to U Staedt.

At least 19 recordsLinked to original sources
PubMed1992

Haemodilution in acute ischaemic stroke comparison of two haemodilution regimen.

In a prospective study we randomly allocated 50 patients with acute ischaemic stroke in the area of the middle cerebral artery within 12 hours after onset to two moderate hypervolemic haemodilution regimen consisting of 500 ml of 10% hydroxyethyl starch per day for 10 days. In the high haematocrit group the target haematocrit of 41-42% was achieved by 0-3 phlebotomies and additional replacement of that volume with the colloid in 3 days. In the low haematocrit group with 1-4 phlebotomies a target haematocrit of 37-38% was reached in 4 days. The groups did not differ regarding age, risk factors, haematocrit and neurological score. The improvement of the disturbed blood rheology was more pronounced in the low haematocrit group. One death occurred in each group. The neurological score showed a significantly greater increase in the low haematocrit group with +59% at day 5 and +125% at day 11; the data for the high haematocrit group were +34% and +89% respectively. We calculated a correlation (r = 0.36, p less than 0.02) between the rise in neurological score and the reduction of haematocrit. Our data suggest but not do prove that an early start on moderate hypervolemic haemodilution is beneficial in patients with acute ischaemic stroke and disturbed blood rheology.

Aged↗
PubMed1991

[The action profile of D,L-kavain. Cerebral sites and sleep-wakefulness-rhythm in animals].

To investigate neurophysiological effects of D,L-kavain, two studies were conducted on unrestrained cats with chronically implanted electrodes. In group A animals (n = 26) we recorded the blood pressure, the EEG of cortical and subcortical areas, the electromyogram, EEG arousal reactions, and subcortical evoked potentials elicited by central stimulation. This was done before and after injection of D,L-kavain (10-50 mg/kg i.p.) or--for comparison--of a kava extract in Ol. arachidis (50-100 mg pyrones/kg i.p.). Group B cats (n = 9) served for polygraphic, 10-h analyses of the sleep-wakefulness rhythm; they received--in a random sequence--0.9% NaCl (3 ml i.p.), D,L-kavain (28 mg/kg p.o.), pentobarbital (1 mg/kg i.m.), or the combination D,L-kavain plus pentobarbital. With both D,L-kavain and the extract, muscle tone was seen to be diminished in about 50% of the experiments. It was only the extract which exerted marked effects on the EEG; it induced high amplitude delta waves, spindle-like formations, and a continuous alpha- or beta-synchronization in the amygdalar recordings (p less than 0.001). Neither D,L-kavain nor the kava extract changed the threshold of the EEG arousal reaction. As to the evoked potentials, the hippocampal response following stimulation of the amygdalar nucleus showed an increase in amplitude in the animals given D,L-kavain (50 mg/kg; p less than 0.05) and in those given the extract (100 mg pyrones/kg; p less than 0.01). In addition, after injection of the extract, further projections arising from the amygdala as well as the connection from the caudate nucleus to the amygdala proved to be activated. The percentage duration of active wakefulness was significantly shortened by both D,L-kavain and pentobarbital, as compared to placebo. There was a likewise significant prolongation of synchronized sleep with D,L-kavain, pentobarbital, and the combination of both these agents. However, a potentiation of drug effects failed to occur. It is concluded from the findings that limbic structures and, in particular, the amygdalar complex represent the preferential site of action for both D,L-kavain and the kava extract. The participation of these structures in modulating emotional processes may explain the promotion of sleep, even in the absence of sedation. There is no congruity of D,L-kavain with either the tricyclic thymoleptics or the benzodiazepines regarding the profile of neurophysiological effects.

Animals↗
PubMed1990

[Conjunctival oxygen partial pressure, hemorheology and circulatory parameters in acute cerebral infarct before and following infusion of 6 percent low molecular hydroxyethyl starch].

A prospective clinical trial was performed on the effects of a three hour infusion of 500 ml 6% low-molecular-weight hydroxyethyl starch in patients with acute ischemic stroke. Hemorheology and conjunctival oxygen tension were found to be disturbed prior to treatment. After the infusion there was a marked improvement of the pertinent parameters, indicative of an increase in cerebral microcirculation and oxygen supply. Even 3 h later persistent significant effects were observed. The infusion was well tolerated. Blood pressure and cardiac index remained unchanged.

Blood Viscosity↗
PubMed1989

[Malignant tumor-like abdominal lymphoma in Whipple's disease].

A 43-year-old man had severe upper abdominal pain and weight loss of 8 kg for over three months. He underwent a laparotomy because, computed tomography having revealed numerous mesenteric and para-aortic lymph nodes, a malignant lymphoma was suspected. Histological examination of a mesenteric lymph node demonstrated exclusively extraintestinal Whipple's disease. The symptoms completely disappeared after the administration of 1.2 mega U penicillin G and 1 g streptomycin daily for 14 days, followed by twice daily 160 mg trimethoprim and 800 mg sulphamethoxazole.

Abdominal Neoplasms↗
PubMed1989

Intra- and extracellular amino acid concentrations in portacaval-shunted rabbits. Role of hyperammonemia and effects of branched-chain amino acid-enriched parenteral nutrition.

Intra- and extracellular amino acid concentrations were measured in rabbits in order to elucidate the possible role of hyperammonemia in lowering the postabsorptive plasma levels of branched-chain amino acids (BCAA) and to assess the effects of BCAA-enriched total parenteral nutrition (TPN) on the amino acid pattern of muscle. The pathophysiological part of this paper deals with portacaval anastomosis (PCA) and is aimed at substantiating or rejecting our hypothesis that excessive ammonia-by stimulating glutamine synthesis-reduces the intracellular glutamate pool which is then restored, at least in part, by an intensified BCAA degradation. Regarding infusion therapy, we were mainly interested in whether an amino acid solution adapted to the metabolism in liver cirrhosis causes an accumulation of BCAA in muscle or modifies the intracellular content of glutamate and glutamine. Eighteen rabbits did not undergo surgery and served as controls (group A), while 30 were given a portacaval end-to-side anastomosis (group B). Two weeks after creating the PCA, venous blood samples were taken and muscle biopsies (Bergström's technique) were performed postabsorptively. An 18-h TPN was then started, the regimen administered included dextrose, fat and, in addition, either a conventional (group B1, n = 15) or an adapted amino acid solution (group B2, n = 15). We obtained second blood specimens and muscle biopsies at the end of the infusion period. With the control animals, the same time schedule for blood sampling and muscle biopsies was followed. Fourteen days after the operation, the PCA rabbits displayed a mean plasma ammonia level 5.1 times higher than that measured in the controls (p less than or equal to 0.001). Conventional blood chemistry did not reveal any impairment of liver cell integrity or over-all hepatic function, whereas the nutritional state of the shunted animals worsened, as indicated by body weight and biochemical variables. Since in the PCA rabbits, the total amino acid pools of muscle and plasma were seen to be increased and decreased, respectively, the results concerning the individual amino acids are given in terms of both the absolute and percentage values, the latter more often revealing high levels of statistical significance. PCA induced a marked rise in the intra- and extracellular concentrations of glutamine, while the values of glutamate and alanine showed a decline in muscle and plasma. The extracellular levels of methionine, phenylalanine, and tyrosine were raised, while those of the BCAA were diminished.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acids↗
PubMed1989

[Effect of hemodilution with 10% hydroxyethyl starch solution (MW 200,000/9.5) on the flow properties of blood, arterial blood gases and conjunctival oxygen partial pressure in patients with cerebral infarct].

Hemorheological parameters, arterial blood gases and conjunctival oxygen tension were measured in 15 patients with acute ischemic stroke and compared with values obtained in an age matched reference group. Since the conjunctival capillary bed is perfused by the ophthalmic artery, it reflects the oxygen delivery to the areas supplied by the internal carotid artery. Measurements of conjunctival oxygen tension are simple and safe. Patients with acute ischemic stroke showed a lowered conjunctival oxygen tension; this holds true especially to the ipsilateral side, i.e. the side where the attack occurred, and to a lesser extent to the other side. By contrast, the ratio of arterial/conjunctival pO2 was disturbed only on the ipsilateral side. Furthermore, these patients had pathologically elevated values for red cell aggregation, whole blood and plasma viscosity. After infusing 500 ml 10% middle-molecular-weight hydroxyethyl starch (10% HAES-steril) and phlebotomy (250 ml) blood fluidity was normalized, although the hematokrit was only slightly reduced. Arterial pO2 improved slightly while pCO2 remained unchanged. Conjunctival oxygen tension improved by 30% on the ipsilateral and by 10% on the contralateral side, the ipsilateral values always remaining significantly lower. The ratio conjunctival/arterial pO2 raised only on the ipsilateral side where it was below the reference range before hemodilution. In addition to the well known improvement of blood fluidity and augmentation of cerebral blood flow following hemodilution in patients with acute ischemic stroke, there seems to be an increase in oxygen supply in the territories of both internal carotid arteries, especially on the ipsilateral side as indicated by the values of conjunctival oxygen tension and the ratio of conjunctival to arterial pO2.

Blood Viscosity↗
PubMed1988

[Churg-Strauss syndrome].

In a 47-year-old man presenting with chronic bronchitis since 1978, a weight loss of 11 kg in 9 months and deteriorated general condition, the x-ray film of the thorax revealed numerous pulmonary nodules of up to 4 cm size. Laboratory findings were characterised by enhanced ESR, blood eosinophilia of 7% and a lot of eosinophilic granulocytes in the sputum. The findings could not be clarified despite many additional examinations including bronchoscopy with transbronchial biopsy. Thoracotomy was finally considered imperative. Pulmonary biopsy revealed necrotising vasculitis, eosinophilic infiltration and epithelioid granuloma, characteristic changes of allergic granulomatous vasculitis (Churg-Strauss syndrome). The condition quickly responded to corticosteroid administration.

Biopsy↗
PubMed1988

[Conjunctival oxygen pressure in patients with acute cerebral infarct].

Conjunctival oxygen tension and arterial blood gases were measured in 20 patients with acute ischaemic stroke and compared to values obtained in a reference group. The conjunctival capillary bed is perfused by the ophthalmic artery and, thus, reflects the oxygen delivery to the areas supplied by the internal carotid artery. Patients with acute ischaemic stroke showed especially on the ipsilateral side, i.e. the side of the infarction, and to a lesser extent on the other side a lowered conjunctival oxygen tension and a reduced ratio of conjunctival to arterial oxygen tension. These findings indicate disturbances of the blood fluidity, of the cerebrovascular autoregulation and of brain microperfusion. Monitoring of conjunctival oxygen tension is simple and safe. This method allows the assessment of oxygen tension in a tissue bed vascularized by the internal carotid artery. It appears to yield an objective criterion of the effectiveness of therapeutic procedures aiming at an improvement of cerebral perfusion and oxygen supply in patients with acute ischaemic stroke.

Aged↗