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Biomedical subjects

L Auer

Publications and source records attributed to L Auer.

At least 19 recordsLinked to original sources
PubMed2001

Development and characterization of an animal model of carnitine deficiency.

Mammals cover their carnitine needs by diet and biosynthesis. The last step of carnitine biosynthesis is the conversion of butyrobetaine to carnitine by butyrobetaine hydroxylase. We investigated the effect of N-trimethyl-hydrazine-3-propionate (THP), a butyrobetaine analogue, on butyrobetaine hydroxylase kinetics, and carnitine biosynthesis and body homeostasis in rats fed a casein-based or a vegetarian diet. The K(m )of butyrobetaine hydroxylase purified from rat liver was 41 +/- 9 micromol x L(-1) for butyrobetaine and 37 +/- 5 micromol x L(-1) for THP, and THP was a competitive inhibitor of butyrobetaine hydroxylase (K(i) 16 +/- 2 micromol x L(-1)). In rats fed a vegetarian diet, renal excretion of total carnitine was increased by THP (20 mg.100 g(-1) x day(-1) for three weeks), averaging 96 +/- 36 and 5.3 +/- 1.2 micromol x day(-1) in THP-treated and control rats, respectively. After three weeks of treatment, the total carnitine plasma concentration (8.8 +/- 2.1 versus 52.8 +/- 11.4 micromol x L(-1)) and tissue levels were decreased in THP-treated rats (liver 0.19 +/- 0.03 versus 0.59 +/- 0.08 and muscle 0.24 +/- 0.04 versus 1.07 +/- 0.13 micromol x g(-1)). Carnitine biosynthesis was blocked in THP-treated rats (-0.22 +/- 0.13 versus 0.57 +/- 0.21 micromol x 100 g(-1) x day(-1)). Similar results were obtained in rats treated with the casein-based diet. THP inhibited carnitine transport by rat renal brush-border membrane vesicles competitively (K(i) 41 +/- 3 micromol x L(-1)). Palmitate metabolism in vivo was impaired in THP-treated rats and the livers showed mixed steatosis. Steady-state mRNA levels of the carnitine transporter rat OCTN2 were increased in THP-treated rats in skeletal muscle and small intestine. In conclusion, THP inhibits butyrobetaine hydroxylase competitively, blocks carnitine biosynthesis in vivo and interacts competitively with renal carnitine reabsorption. THP-treated rats develop systemic carnitine deficiency over three weeks and can therefore serve as an animal model for human carnitine deficiency.

Animals↗
PubMed1995

Cost-effectiveness in ambulatory care: alternative approaches.

By relating health care resources and their use to health outcomes, through a coherent macro resource allocation framework, one can examine the health care system for allocative efficiencies. In this article, costs and outcomes are analyzed in such a framework, scenarios for optimizing the use of health care resources--while still maintaining existing health outcomes--are explored, and the implications for ambulatory care are discussed. The research clearly shows that much can be done to make health care systems more efficient without jeopardizing health outcomes.

Ambulatory Care↗
PubMed1987

[Significance of the examination position in urodynamic assessment of female urinary incontinence].

The present paper describes a test center which permits urodynamics tests with the patient in various positions, such as lithotomy position (A), supine position with outstretched legs (B) and, by continuously raising the patient, upright position (C). The results of a comparative investigation show the influence of these different examination positions on urodynamic parameters, in particular the functional length of the urethra and maximum urethra closing pressure at rest. Urodynamic tests on 40 patients with urinary incontinence showed that there is a significant increase in the functional length of the urethra when the patient is in lithotomy position (A) as compared to lying with outstretched legs (B), and that it is once again significantly reduced when the patient is raised to upright position. Maximum urethra closing pressure at rest drops significantly when the patient is repositioned from lithotomy (A) to supine (B) position, and once again rises significantly when she is raised to the upright (C) as compared to the supine (B) position. In the light of the changes described, which cause major changes in the form of the urethra pressure profile, it makes sense to perform urodynamic measurements in at least two different positions. The authors recommend the supine position with outstretched legs (B), as it appears more physiological than the lithotomy position (A), and measurement in the upright position (C). The importance of positioning with regard to the diagnostic information value in determining the cause of urinary incontinence is discussed.

Adult↗
PubMed1987

Continuous and simultaneous monitoring of EEG spectra and brainstem auditory and somatosensory evoked potentials in the intensive care unit and the operating room.

Individual monitoring of EEG and evoked potentials is gradually becoming standard in neurosurgery: compressed power spectra during carotid endarterectomy, brainstem auditory evoked potentials (BAEP) during posterior fossa surgery, and somatosensory evoked potentials (SEP) mainly during spinal cord surgery. In this paper, a new technique is described in which EEG, BAEP, and SEP are recorded and evaluated simultaneously and continuously. This allows a better survey of different neuronal structures and systems in the brain and brainstem. First results from intraoperative and intensive care patient monitoring are reported.

Adult↗
PubMed1985

Fetal behavioural states and controlled sound stimulation.

The aim of this study was to investigate responses of human fetuses near term (37-42 wks) (increase/decrease of fetal heart rate and/or fetal motility) to acoustic stimuli. The study group consisted of 43 patients and the control group of 27 patients. Polygraphic recordings of 5 different fetal variables were carried out synchronously for the categorization of the actual fetal behavioural state according to Nijhuis et al. (Nijhuis, J.G., Prechtl, H.F.R., Martin, C.B., Jr. and Bots, R.S.A.M. (1982): Early Hum. Dev., 6, 177-195). Controlled acoustic stimulation was performed either with sine wave tone (2 kHz, 120 dB and 5 s duration) or modulated sine wave tone (0.5-2 kHz, 'sawtooth' modulation, 120 dB and 5 s duration). An additional group of patients received 'sham' stimulation. Overall 84 acoustic stimulations have been carried out. In 26 out of 84 stimulations (30%) a fetal response could be observed within 5 s after acoustic stimulation. In general, there were far fewer fetal responses in sleep states than in states of wakefulness. Whereas in state 1 F only 1 out of 28 acoustic stimulations was followed by an immediate fetal response, more responses were observed in state 2 F. An obvious increase in fetal reactivity to acoustic stimulation was noted in states of wakefulness (states 3 F and 4 F). Comparison between the true and sham stimulations revealed a relatively high level of spontaneous fetal activity (high variation of fetal heart rate and fetal motility) present in states 2 F and 4 F. This must be taken into account in all assessments of fetal responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMed1983

Transfusion reactions in cats due to AB blood group incompatibility.

Blood transfusion reactions were investigated in 70 unsensitised and sensitised cats. Twenty-five compatible transfusions with respect to the AB blood group system did not result in any immediate transfusion reactions. Transfusion of B erythrocytes in 12 group A cats did not produce any severe reactions because of low anti-B titres in the A recipients. However, 30 of 50 group B cats (60 per cent) suffered severe shock reactions, characterised by marked hypotension, cessation of respiration and sometimes atrio-ventricular blocks, within two minutes of the injection of incompatible A cells (phase 1). From 35 seconds to five minutes later, markedly elevated blood pressures and extrasystoles were recorded (phase 2). The blood pressures generally stabilised within 30 minutes. Haemoconcentration and leucopenia were observed in severely reacting cats and leucopenia was also recorded in some A cats who received incompatible cells but did not exhibit transfusion reactions.

ABO Blood-Group System↗
PubMed1982

Blood transfusion reactions in the cat.

The transfusion of only 4 ml of group A blood resulted in sudden death of a cat that was recovering from surgery. The clinical signs were similar in many respects to those exhibited by tranquilized group B cats when challenge exposed for the 1st time with incompatible A cells. The distribution of the A and B blood group antigens and the occurrence of naturally occurring isoantibodies in the cat were considered in relation to the probability of producing transfusion reactions. The results obtained with tranquilized and anesthetized cats demonstrated that immediate reactions can occur following the 1st transfusion of incompatible red blood cells. Cross matching with respect to the AB system is recommended before giving blood transfusions to cats.

ABO Blood-Group System↗
PubMed1982

The influence of skull defects and reperfusion after extra-intracranial arterial bypass surgery on the sensorimotor EEG rhythm.

Twelve patients with small burr hole skull defects after extra-intracranial arterial bypass surgery were studied. The amplitude and frequency of the sensorimotor rhythm were measured 7 days and 1, 2, 4, and 6 months after surgery in follow-up EEGs from the central region. Seven patients showed a frequency decrease (compared with preoperative measurement) on the operated side 7 days and/or 1 month after surgery. There was no case of frequency decrease 6 months after surgery; four patients displayed a late frequency increase. Ipsilateral amplitude enhancement was never found 7 days postoperatively, but after 6 months in nine patients. Such physical factors as burr holes and bone replacement can only partially explain the amplitude enhancement, and cannot explain the frequency decrease. It may be assumed that temporary clamping of the middle cerebral artery and/or reperfusion of an ischaemic area result in a brief deterioration of brain function, as indicated by frequency slowing and delayed amplitude enhancement; related observations were made in patients with cerebrovascular disorders and mild to moderate neurological deficit about 20 days after the onset and correlated with clinical recovery.

Adult↗
PubMed1982

A contribution to the monitoring of fetal arrhythmias.

Antepartum and intrapartum monitoring problems are discussed with reference to a case history of a fetal AV-block detected during the 36th week of pregnancy. CTG instruments where the internal logic criteria can be turned off are suitable for monitoring arrhythmias. During labor the direct fetal ECG permits exact diagnosis as to the type of arrhythmia. The necessity of antepartum diagnosis in regard to postpartum pediatric management and hypoxic states during labor justify the large expenditure on monitoring apparatus. During labor continuous tissue pH measurement via the fetal scalp give added information as to fetal condition.

Adult↗
PubMed1981

[A new oxytocin infusion rate recorder (author's transl)].

A new oxytocin-infusion rate recorder system is introduced. It provides continuous plotting dosages on the labor channel of the cardiotocogram. So far 82 conductions of labour were monitored with the new system and evaluated for oxytocin overstimulation. The rate of overstimulations could be reduced resulting in better fetal outcome.

Female↗
PubMed1981

Phosphohexose isomerase polymorphism in the domestic cat.

Genetic variation of the enzyme phosphohexose isomerase (PHI) has been found in the erythrocytes of Australian domestic cats by horizontal starch gel electrophoresis at pH 8.2. Three complex patterns of isoenzymes, designated F, FS and S, were obtained migrating anodally. Limited family studies and the distribution of the three main phenotypes indicated that the polymorphism in controlled by two codominant autosomal alleles, PHIF and PHIS. Gene frequencies for PHIF and PHIS have been calculated as 0.036 and 0.964 respectively. Three additional variant forms have also been observed.

Alleles↗
PubMed1981

The AB blood group system of cats.

Holmes (1950) and Eyquem, Podliachouk & Milot (1962) classified feline erythrocytes into two types according to their reactions with naturally occurring antibodies in cats' plasmas. Eyquem et al. (1962) designated the two antigens, A and B, and this nomenclature has been retained in the present study. The blood group system, AB, was investigated in more detail, both genetically and serologically. Frequencies of 73.3% A and 26.3% B were found in a survey of 1895 Brisbane cats and in addition, a new phenotype, AB, was discovered with a low incidence of 0.4%. The results of the serological testing and limited family information suggested that the AB phenotype is inherited and not due to blood chimaerism. Preliminary genetic studies indicated that the A gene is dominant to the B in the usual situation and hypotheses to explain the occurrence of the AB phenotype are discussed. The incidence of naturally occurring antibodies was investigated in cats, with 95% of blood type B having anti-A and only 35% of type A having anti-B. No subgroups of the A and B antigens were detected and no blood group substances were found in the salivas of 37 cats. There was no evidence of any serological relationship of the feline A and B antigens with the human ABO antigens.

ABO Blood-Group System↗
PubMed1981

[Vascular surgery in ischemic cerebral infarction (author's transl)].

Ischemic cerebral infarction requires surgical treatment, if based on stenosis or occlusion of an internal carotid or middle cerebral artery. The selection of the patients and the indications for carotid thrombendarterectomy or extracranial-intracranial arterial bypass are discussed. Preoperative testing of patients under hyperbaric oxygenation may be important for the success of an operation. Report on the experience with 128 surgically treated cases.

Adult↗
PubMed1980

Pial arteriolar reaction to intravenous administration of bencyclane in the cat.

In a series of 29 experiments in cats, the vasodilatory effect of Bencyclane on pial arterioles was investigated by means of the cranial window technique, using an image-splitting eyepiece, a photometric method or simple microscopic observation. Intravenous injection of 3 mg kg-1 led to vasodilatation in all experiments, yet decreased blood pressure within 30--40 sec until 5--6 min down to 70% of resting pressure. Mean maximal dilatation of arterioles with a 76-micrometers mean resting diameter was 53%. After normalization of blood pressure, arteriolar diameters remained increased by 5--10% for further 10 min, thus indicating increased cerebral blood flow for a total time of about 15 min. During intravenous infusion of 0.2--0.3 mg kg-1min-1 of the drug, pial arterioles dilated by about 10% with blood pressure remaining on resting levels. A higher dosage rate of infusion evoked further vasodilatation, yet parallel decrease of blood pressure.

Animals↗
PubMed1980

Medical versus surgical treatment of patients with cerebrovascular insufficiency. A retrospective comparative study.

Report on a series of patients suffering from cerebrovascular insufficiency caused by stenosis and/or occlusion of one or several major cerebral vessels. The patients were divided in two groups, one being medically treated with anticoagulants, the other operated on either a carotid artery thrombosis by thromboendarterectomy or occlusion treated with an extracranial-intracranial arterial bypass. Results after a follow-up period of 1-3 years are compared and discussed in view of the recent literature.

Adult↗
PubMed1979

[Therapy of traumatic brain edema with spironolactone (author's transl)].

In 30 patients with severe brain injury a double-blind study was performed. The effectiveness of the aldosterone-antagonist Aldactone pro injectione was examined in therapy of traumatic brain edema. The results indicate elimination of sodium and water from brain cells and white matter. Concomitantly faster improvement of state of consciousness was observed.

Adolescent↗