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Biomedical subjects

H Steiner

Publications and source records attributed to H Steiner.

At least 199 records · Page 11Linked to original sources
PubMed1991

[The limits of the differential diagnostic capacity of CT and sonography in cystic hepatic echinococcosis].

In regions of only sporadic occurrence of hydatid disease, the heterogenic appearance of the cysts often causes a diagnostic dilemma. In 28 patients the reports of sonography and/or computed tomography, without and during bolus injection of 100ml anionic contrast material, were compared to the results of the indirect haemagglutination test (IHA). In six cases additionally the enzyme-linked immunosorbent assay (ELISA), and in nine the histologic specimen were evaluated. The authors discuss the value of CT and US reporting on their experience and the difficulties in establishing the diagnosis in 14 histologically and/or serologically proven cases and another 14 cases with "typical" appearance but negative serology and/or histology.

Animals↗
PubMed1991

Arterial macroaneurysm of the optic disc.

A 64-year-old man presented with an arterial macroaneurysm on the optic disc, an unusual location for retinal arterial macroaneurysm. The macroaneurysm resolved spontaneously without sequelae.

Aneurysm↗
PubMed1991

Optimum technique of light brightness assessment in control subjects and patients with ocular hypertension and glaucoma.

The light brightness test is an investigation in which crossed polarizing lenses placed in front of each eye are rotated with respect to one another to ellicit any disparity in perception of a diffusely illuminated screen. A number of different strategies can be employed to achieve the aim of determining the degree of disparity which is perceived as equal by the patient. A cohort of 45 control subjects was assessed in order to determine the ranges of brightness disparity accepted as equal for six methods of assessment. The method which gave the optimal confidence limit was to preset one pair of lenses at 0 degrees (maximum transmission) and the other as a fixed reference at 45 degrees. Rotation of the lens set at 0 degrees was carried out until the brightness of an X-ray box is perceived as equal. The strategy was then reversed. A disparity in one or both recordings greater than 76.5% is outside 99% confidence limits for the whole population studied. One of 14 patients with ocular hypertension gave a consistently 'positive' results. For the optimal method, over 60% of patients with glaucoma fell outside 95% condidence limits for normal controls indicating that a disparity in brightness perception between eyes is a common feature in glaucoma, in which the disease process usually affects one eye more than the other. For the patients with chronic glaucoma there was a positive correlation between the difference in brightness perception and the difference in central visual field score, indicating that brightness perception may be subserved by the central 30 degrees of the retina. When combined with visual acuity assessment this easily performed test warrants evaluation as a potential screening test for chronic glaucoma.

Chronic Disease↗
PubMed1991

[Color-coded duplex sonography of dysfunctional kidney transplants. Correlation of the resistive index with the histopathologic results of biopsy].

The resistive index (RI) is used as a measure of the vascular resistance in renal allografts. The sample volume for the measurement can be positioned much more exactly with color duplex US than with duplex US, resulting in more precise values for the RI. To find out which pathologic changes lead to an increase of the RI, we correlated the RI with the histopathological results obtained in 43 biopsies. Our results show that it is not possible to differentiate between vascular and interstitial rejection on the basis of the RI because there is no statistically significant difference between the RI values caused by the two types of rejection. Distinct interstitial infiltration, edema of any origin, vascular changes and also chronic rejection and arteriolosclerosis lead to elevated RI. A good correlation was found between the elevation of RI and the severity of the vascular changes. Severe tubular and glomerular changes, cyclosporine toxicity, tubular necrosis, cytomegaly infection, glomerulonephritis and dysfunctions of other causes did not lead to elevation of the RI.

Adult↗
PubMed1991

[The significance of computed tomography and ultrasound in the diagnosis of puerperal ovarian vein thrombophlebitis].

The diagnosis of puerperal ovarian venous thrombophlebitis (POVT) is problematic, not only because of the low and variable incidence (1:600-6000 births), but also because there are no characteristic clinical symptoms. So far, therefore in 80% of cases it has been diagnosed by exploratory laparatomy. Early non-invasive diagnostic procedures must be aimed at, because surgical intervention involves a high rate of complications and uncomplicated cases can be treated by conservative methods (broad-spectrum antibiotics and anti-coagulants). Several case reports refer to the possibility of recognizing POVT by real-time ultrasound (US) and computer tomography (CT). Two cases are described to illustrate this option for preoperative diagnosis by CT and US. A tubular, annular structure with ring enhancement after application of dye along the anatomical course of the ovarian vein seems to be characteristic for POVT.

Adult↗
PubMed1991

[Diagnosis of fetal thrombocyte count in relation to obstetric management of maternal idiopathic thrombocytic purpura (Werlhof disease)].

Beside maternal, fetal platelet count is the essential parameter for the decision about the obstetrical management in ITP-patients in pregnancy. Evaluation of fetal platelet count contains different problems. Using heparinised capillary tubes in fetal blood sampling procedure, platelet aggregation occurs and therefore false low platelet counts are found, by the commonly used method of conductivity measurement. A recently observed case is reported.

Adult↗
PubMed1990

Structure of preproattacin and its processing in insect cells infected with a recombinant baculovirus.

From a cDNA library made from fatbody of immunized Hyalophora cecropia pupae, a full-length clone corresponding to basic attacin was isolated. The corresponding amino acid sequence suggests that basic attacin is synthesized as a 233-residue preproprotein. This was confirmed by cloning the cDNA fragment encoding the basic attacin in the baculovirus Autographa californica nuclear polyhedrosis virus downstream of the polyhedrin promoter and expressing the protein in Spodoptera frugiperda (Sf9) cells. Biologically active attacin was also produced in last instar larvae of Trichoplusia ni after injection of recombinant virus. The concentration obtained was 300-500 times that obtained in cell culture supernatants. In cell culture the induction kinetics of attacin were followed at both transcriptional and translational levels. From the protein processing pattern it was suggested that a protease produced by the Spodoptera cells cleaves attacin at the double arginine residues at positions 45 and 46. The instability of the attacin proteins is rationalized in terms of their random-coil structure which was deduced from circular dichroism measurements.

Amino Acid Sequence↗
PubMed1990

Effects of hemivibrissotomy in the rat: time-dependent asymmetries in turning and biogenic amines induced by apomorphine.

Behavioral and neurochemical changes accompanying unilateral removal of vibrissae were investigated in the rat. Rats were tested either 4 hours or 10 days after hemivibrissotomy. A systemic injection of apomorphine (0.5 mg/kg) induced turning behavior towards the intact vibrissae side in rats tested 4 hours after hemivibrissotomy. Compared to these animals, apomorphine induced more turning towards the side of vibrissae removal and less turning towards the intact side in animals tested 10 days after vibrissae removal. This reversal is suggestive of time-dependent changes in dopamine receptor sensitivity. Analysis of biogenic amines (dopamine, norepinephrine, serotonin) in the hemispheres ipsi- and contralateral to the side of vibrissae removal revealed evidence for neurochemical changes in apomorphine- and amphetamine-treated rats. Lateralized and bilateral differences were found in the neostriatum, septum and ventral mesencephalon, which were dependent on the side and duration of hemivibrissotomy. These results are discussed with respect to the behavioral and neural analogy between hemivibrissotomy and unilateral 6-hydroxydopamine lesions of the nigrostrial system.

Amphetamine↗
PubMed1990

Plasticity in crossed and uncrossed tuberomammillary-striatal projections in relation to recovery from behavioral asymmetries induced by hemivibrissotomy.

The influence of unilateral removal of the adult rat's vibrissae on crossed and uncrossed tuberomammillary-striatal projections was examined with the horseradish peroxidase tract tracing technique. Striatal afferents from the caudal magnocellular and the postmammillary caudal magnocellular subnuclei of the tuberomammillary nucleus were investigated. Between four and 20 days after clipping the vibrissae on one side, more retrogradely labeled cells were found in the crossed and uncrossed projections from both subnuclei to the caudate-putamen of the hemisphere opposite to vibrissae removal (i.e. the sensory deprived hemisphere) than in the projections to the caudate-putamen on the vibrissae-clipped side. In contrast, between one and three days after clipping the vibrissae no asymmetries in cell-labeling in these projections were found. This time-course of changes in the tuberomammillary-striatal projections is similar to the time-course of behavioral recovery reported after unilateral removal of vibrissae. Thus, the neural changes in these projections appeared at the point in time when rats recovered from behavioral asymmetries induced by vibrissae removal.

Animals↗
PubMed1990

The basal ganglia-orofacial system: studies on neurobehavioral plasticity and sensory-motor tuning.

We have employed the unilateral removal of the vibrissae as a tool to examine ensuing behavioral changes in relation to concomitant changes in the central nervous system. In this paper we review a series of studies showing that unilateral removal of the vibrissae leads to behavioral asymmetries (e.g., in thigmotactic scanning) from which rats recover over time. Time-related to these behavioral changes we found neuronal alterations in striatal afferents, that is, in uncrossed and crossed projections from the substantia nigra and the tuberomammillary nucleus. The involvement of dopaminergic mechanisms was indicated by results showing that dopaminergic agonists can induce asymmetries in thigmotactic scanning and turning; the direction of these asymmetries was also dependent on time after vibrissae removal. Furthermore, it was shown that endogenous preferential use of one vibrissae side in thigmotactic scanning interacts with the expression of spontaneous and drug-induced behavioral asymmetries exhibited after unilateral vibrissae removal. Neurochemical studies indicated that both unilateral vibrissae removal and unilateral perioral stimulation can have lateralized effects on biogenic amines in the brain. Finally, using electrical stimulation of the substantia nigra, evidence was found for a lateralized and bidirectional interaction between basal ganglia and the orofacial systems, indicating an involvement in mechanisms of motivation and particular stimulation. These results are important from several perspectives. One, they indicate functional links between the orofacial systems and the basal ganglia. Two, they raise the possibility that unilateral removal of the vibrissae can serve as a model (a) to investigate the dynamics of recovery of function after CNS insults, in general, and specifically, (b) to study neuronal plasticity in the nigrostriatal and tuberomammillary-striatal pathways, and (c) to investigate the neuropharmacology of catecholamine systems in the brain.

Animals↗
PubMed1990

Interaction between recovery from behavioral asymmetries induced by hemivibrissotomy in the rat and the effects of apomorphine and amphetamine.

Spontaneous and drug-induced turning behavior and thigmotactic scanning were tested either acutely (4-6 hr) or chronically (9 days) after unilateral removal of vibrissae in rats. Rats that were tested acutely scanned more with the intact vibrissae side. This asymmetry was reduced in rats that were tested chronically, indicating behavioral recovery. The indirect dopamine agonist amphetamine induced a reversed asymmetry after 9 days because the animals then scanned more with the side lacking the vibrissae. Postsynaptic doses of apomorphine administered to acutely tested rats induced more scanning with, and more turning toward, the intact vibrissae side. A negative correlation was found in the chronically tested rats between the asymmetry in spontaneous scanning and the asymmetry after apomorphine. Nonrecovered rats showed indications of a reversal after apomorphine. The results are discussed in relation to mechanisms of neural plasticity in the basal ganglia, such as receptor supersensitivity and changes in nigrostriatal afferents.

Amphetamine↗
PubMed1990

[Doppler examination as an indication for surgical delivery. A case report].

Pathological alterations in foetoplacental circulation can lead to zero flow or even to reverse flow in the diastole. In these cases, a high fetal risk can be expected. Based on our Doppler measurements, we recommend by zero flow in the umbilical artery or foetal aorta, that the childbirth could be postponed under an observant attitude using intensive controls (CTG, foetal movements), but pregnancy has to be terminated immediately by Caesarean section at the first sign of reverse flow.

Adolescent↗
PubMed1990

[Clinical value of a decrease in diastolic flow in obstetric Doppler sonography].

Doppler ultrasound in obstetrics is being increasingly accepted in foetal surveillance. For clinical practice, a good correlation between Doppler findings and biochemical data such as blood gas analysis and lactate as a metabolical parameter, would be desirable. To clarify this question, these results have to be compared. Prepartal Doppler results which are correlated with postpartal blood gas analyses of umbilical vessels cannot be a satisfactory criterion due to the influence of labour on these parameters. Therefore, we depend on results from foetal blood sampling procedure. The five cases presented here should be a contribution to this discussion. In summary it can be concluded, that in cases of a highly pathological Doppler analysis in the umbilical artery, intrauterine growth retardation must be expected. If there is an acidosis in the foetal organism, it can be assessed via the foetal carotid findings. This, therefore is our contribution to the discussion on the indication for Caesarean section in cases of absent diastolic flow: Absence of diastolic flow in the umbilical artery and foetal aorta only without centralisation by increased perfusion in the foetal carotid, is, in our opinion, not an indication for Caesarean section. We believe, that foetal acidosis confirmed by foetal blood gas analysis indicated by the Doppler result, is an efficient completion of obstetrical management in risk pregnancies. Any further decision on conservative management or termination of pregnancy can be taken more easily on the basis of biochemical data, especially in situations, where conventional methods of foetal surveillance cannot clarify the perinatal risk sufficiently.

Adolescent↗
PubMed1990

[The course of pregnancy in lupus anticoagulant syndrome].

More than 95 per cent of the pregnancies with circulating lupus anticoagulant (LA) without therapy lead to abortion or intrauterine death. We report on the course of a pregnancy in a patient, who developed deep venous thrombosis and circulating LA. One of the rare cases of successful pregnancy management without the common prednisolone-aspirin therapy, but with heparin-monotherapy associated with intensive medical and obstetrical surveillance under clinical conditions is reported. In spite of intermittent corticosteroid and immunoglobulin application, a healthy child was born, although normalisation of the aPTT and platelet count was not achieved. It seems, that an alternative concept of therapy may have been established.

Autoantibodies↗