PubMed Health⌕ Search

Biomedical subjects

H Bauer

Publications and source records attributed to H Bauer.

At least 37 records · Page 2Linked to original sources
PubMed1993

Neovascularization and the appearance of morphological characteristics of the blood-brain barrier in the embryonic mouse central nervous system.

Vascularization and expression of blood-brain barrier (bbb)-associated morphological characteristics during the embryonic development of the mouse central nervous system (CNS) was studied by ultrastructural analysis. At embryonic day 9 (E9) capillaries were only found in the perineural mesenchymal tissue. These capillaries showed fenestrations, and pericyte like cells (PC) were found joined to the vessel walls. Around E10 endothelial cells (EC) together with PC started invading the intraneural section. At this stage, the immigrating endothelial cells lost their fenestrations and exhibited numerous, partly extended junctional complexes, which appeared 'tight' in some places. A first intraneural anastomotic plexus was observed at E10, as evidenced by the presence of blood cells in all capillary lumens. While the number of junctional complexes remained constant in intraneural capillaries, the frequency of pinocytotic vesicles decreased significantly from E10 to E17. These findings indicate that from the first day of intraneural vascularization onwards, the morphological properties of the bbb are present in the early embryonic mouse cerebral cortex.

Animals↗
PubMed1993

The 'oddball CNV' as an indicator of different information processing in patients with panic disorders.

In previous studies we found an inverse relationship between CNV amplitude and the probability of the occurrence of the warning stimulus (S1) in a cued reaction time task. The aim of the present study was to investigate this 'oddball effect' on CNV amplitude (Oddball CNV) in patients with anxiety disorders, since this effect describes the influence of event probability on reactive as well as proactive components of information processing. Patients suffering from panic disorders with or without agoraphobia and controls participated in a choice reaction time experiment. The subjects' task was to respond to flashes (S2s), cued 4 s in advance in random order by one of two easily distinguishable acoustic stimuli (S1a, S1b). In condition 1 the probability of S1a and S1b was 0.2 and 0.8, respectively, and in condition 2 0.5 for both S1s. The DC-EEG was recorded from F3, F4, C3, Cz, C4 and P3, linked mastoids as the reference. The data obtained confirm the oddball effect on the CNV amplitude, show clear deviations of patients in this effect, and also indicate remarkable differences in CNV shape between patients and controls. These observations are discussed as differences in information processing and information utilization.

Adult↗
PubMed1993

[Tuberculous mastitis--a rare differential diagnosis of non-puerperal mastitis].

Tuberculosis in a case of non-puerperal mastitis is a rare clinical finding. A special case of a 28-year old Thai patient was diagnosed and successfully treated with an antituberculous chemotherapy. The most important diagnostic procedure was the microbiological and histological investigation to enable the diagnosis to be made. Surgical therapy was not necessary.

Adult↗
PubMed1993

Transcription-independent activation of ornithine decarboxylase activity by heparin in cloned cerebral endothelial cells.

Heparin, a highly sulfated glycosaminoglycan, is known to be obligatory for long-term endothelial cell cultures; it potentiates the mitogenic activities of endothelial cell growth factors and prolongs the replicative life span of the cells. Here we have shown that besides its growth factor-supportive role, heparin exerts a specific action on cerebral capillary endothelial cells (cECs), unrelated to serum or growth factors, by increasing activity of ornithine decarboxylase (ODC; EC 4.1.1.17) in these cells. For our experiments we have used two different types of cloned cECs: type I cECs, grown in the presence of endothelial cell growth factor and heparin, and type II cECs, usually cultivated without growth factors. Heparin action on ODC activity was shown to be dose dependent within the range of 1-100 micrograms/ml. Increasing concentrations of or depletion of endothelial cell growth factor from type I cultures had no effect on ODC activity. The increase in enzyme activity was highest after 30 min to 1 h of heparin treatment. As evidenced by northern analysis, the heparin-mediated enhancement of ODC activity was not accompanied by changes of ODC mRNA levels. Studies of DNA replication revealed that in the absence of heparin-binding growth factors, heparin did not affect the proliferative activity of cloned cECs.

Animals↗
PubMed1992

Comparison of gene expression of extracellular matrix molecules in brain microvascular endothelial cells and astrocytes.

By use of random-primed cDNA probes the expression of extracellular matrix molecules in cerebral microvascular endothelial cells (cEC) and in astrocytes from mouse brain was examined. Two phenotypically different batches of cloned cEC were used. Expression of major adhesive ECM molecules, constituting the endothelial basement membrane (i.e., fibronectin, laminin A, B and collagen IV) and of other attachment factors, such as SPARC (osteonectin), tenascin and thrombospondin 1, was examined. We have demonstrated that cEC of different morphology display variations in the expression of fibronectin (FN), thrombospondin 1 (TSP1) and collagen IV (C IV). Astrocytes were shown to contain FN, TSP1, TN and SPARC mRNA. Unexpectedly, SPARC mRNA could not be detected in any of the capillary endothelial cells examined. Therefore, we suggest that astrocytes are likely to be involved in endothelial differentiation and function in the central nervous system via ECM molecule secretion.

Animals↗
PubMed1992

Embryonic development of the CNS microvasculature in the mouse: new insights into the structural mechanisms of early angiogenesis.

Vascularization and expression of blood-brain barrier (bbb) associated morphological characteristics were studied by ultrastructural analysis during the embryonic development of the mouse CNS. At day 9 (E9) capillaries were only found in the perineural mesenchymal tissue exhibiting fenestrations and loosely attached pericytes. At E10 endothelial cells (EC) together with pericytes and other mesenchymal cells invaded the intraneural domain. The immigrating EC showed numerous protrusions and lost their fenestrations as soon as the new intraneural capillaries were formed. Intraneural EC showed prominent nuclei, many pinocytotic vesicles and junctional complexes which appeared tight in some places. These results indicate that from the first day of intraneural vascularization onwards, the morphological properties of the bbb are present in the early embryonic mouse cerebral cortex.

Animals↗
PubMed1992

Effects of thiopentone/suxamethonium on intraocular pressure after pretreatment with alfentanil.

The effects of pretreatment with alfentanil on intraocular pressure (IOP) were investigated in 40 patients undergoing ophthalmic surgery. Patients were randomly allocated to two study groups. Group 1 patients (n = 20) received alfentanil 15 micrograms.kg-1, vecuronium 0.01 mg.kg-1, thiopentone 3-4 mg.kg-1, and suxamethonium 1 mg.kg-1 for anaesthetic induction, whereas patients in group 2 (n = 20) received vecuronium 0.01 mg.kg-1, thiopentone 3-4 mg.kg-1, and suxamethonium 1 mg.kg-1. A total of seven measurements of intraocular pressure were taken in each patient, starting before premedication and ending after extubation of the trachea. In group 2 patients, there was an increase in IOP after endotracheal intubation. In group 1 patients, a decrease in IOP occurred which was related to the decrease in arterial blood pressure. We conclude that alfentanil pretreatment can prevent the increase in IOP following suxamethonium administration.

Aged↗
PubMed1992

Rare events and the CNV--the oddball CNV.

Event-related brain potentials (ERPs), such as Nd and P300, change as a function of the proportion of time if a rare, significant, stimulus occurs. This 'oddball' paradigm has had a significant influence on the interpretation of ERPs in terms of the psychological and information-processing functions they reflect. Interpretations of transient components have differed considerably from that of the sustained potential known as the Contingent negative Variation (CNV), the latter appearing to reflect proactive rather than reactive brain processes. However, experiments in monkeys indicated that the CNV was also sensitive to the oddball effect. The purpose of this experiment was to replicate that finding in humans. The CNVs and P300s of five male and five female college students were studied under three conditions involving different proportions of two types of warning stimuli in a cued reaction time task (paired tone and light). The proportions of one of the warning stimuli, with respect to the total number of trials, were 0.10, 0.30 and 0.50. P300s were larger when elicited by rare warning tones only in the 0.10 condition with maximum P300 amplitude at the parietal site. CNVs at frontal and central areas were larger when the warning cue was the rare event, but there was no effect at the parietal site. These findings may require a rethinking of specific information processing interpretations of other endogenous ERPs, although the results also indicate that the 'oddball' effect on the P300 and CNV was distinctive in terms of scalp distributions and sensitivity to the manipulation.

Adult↗
PubMed1992

[Genital tuberculosis in the woman--only of interest in medical history?].

Genital tuberculosis still occurs and is difficult to diagnose. The symptoms are mostly uncharacteristic, whereas infertility and chronic pelvic infections are frequently diagnosed. In the period between 1970 to 1990, we found 21 women with this diagnosis. The occurrence seems to have shifted to greater age and milder clinical disease and are mostly observed within the framework of the sterility complex. We conclude, that primary treatment should be conservative. Intrauterine pregnancies after treatment are very rare, but, in one case, a normal pregnancy and delivery was occurred.

Adult↗
PubMed1992

Evaluation of serum ferritin as a marker for adult Still's disease activity.

Extremely high serum ferritin values (greater than 10,000 micrograms/l) were detected in two patients with adult Still's disease. The ferritin concentrations decreased to normal after adequate treatment. During a one year follow up ferritin concentration was helpful in monitoring disease activity and guiding decisions about treatment. Raised concentrations of soluble interleukin 2 receptors (sCD25) were also found. Detection of ferritin values above 3000 micrograms/l should lead to the consideration of Still's disease when there is an acute febrile illness without evidence for bacterial or viral infections, serum ferritin being suitable for monitoring treatment.

Adult↗
PubMed1992

A multicenter double-blind study of three different doses of the new cAMP-phosphodiesterase inhibitor rolipram in patients with major depressive disorder.

A multicenter randomized 4-week interindividual double-blind study was carried out in 58 hospitalized patients with major depressive disorder (DSM III 296.23, 296.22, 296.33, 296.32, 296.53 and 296.52) to test the dose-effect relationship of three different doses of the new cAMP-phosphodiesterase inhibitor rolipram: 3 x 0.25 mg, 3 x 0.50 mg and 3 x 1.00 mg rolipram/day. With respect to the desired effect, the 3 x 0.50 mg dosage stood out from the others in almost all relevant parameters. With respect to the response rate, the efficacy of the 3 x 0.25 mg dosage was about the same as that reported in the literature for placebo. The inferior performance of the 3 x 1.00 mg dosage compared to the 3 x 0.50 mg dosage might indicate a reverse U-shaped dose-effect relationship. There was good tolerance to all three dosages. There were no findings that might cast doubt on the safety of the dosages tested.

Antidepressive Agents↗
PubMed1992

Mineralocorticoids and mineralocorticoid receptors in mononuclear leukocytes in patients with pregnancy-induced hypertension.

To examine the role of mineralocorticoids in the pathophysiology of pregnancy-induced hypertension (PIH), we studied plasma aldosterone and 18-hydroxycorticosterone levels in 25 women with PIH and 25 normal pregnant women, as controls. Furthermore, we evaluated the mineralocorticoid receptor (MR) status in mononuclear leukocytes in the 2 groups. MR count was significantly (P less than 0.0005) decreased in the PIH group (148 +/- 9 binding sites/cell) compared with the control group (300 +/- 17 binding sites/cell; mean +/- SEM). Plasma aldosterone in women with PIH was 281 +/- 61 pmol/L; in normal pregnant women it was 697 +/- 172 pmol/L (P less than 0.025). Plasma 18-hydroxycorticosterone was also significantly (P less than 0.025) lower (PIH, 1071 +/- 149 pmol/L; controls, 1907 +/- 318 pmol/L). These values were determined at the onset of clinical symptoms of PIH. These results cannot be explained by receptor down-regulation due to higher levels of mineralocorticoids in PIH; a hitherto unknown mineralocorticoid may, thus, be responsible for the hypertension and altered MR status.

18-Hydroxycorticosterone↗
PubMed1992

[Organ donation to hospitals not specializing in transplantation].

The necessary and possible rate of transplantations is limited by the insufficient availability of donor organs. In the FRG, only 36% of all hospitals (transplantation centers excluded) are active in postmortem organ donation. In only 57% are other organs than the kidneys (liver, pancreas, heart, lung) explanted. The main problems do not derive primarily from structural difficulties (no intensive care unit, limited capacity of operation room or staff), but from an insufficient degree of cooperation with the transplantation center and an uncertain legal position. Possible solutions to the problem (transplantation coordinator, legal regulation) are discussed.

Germany↗
PubMed1991

Reversible expression of sm alpha-actin protein and sm alpha-actin mRNA in cloned cerebral endothelial cells.

The expression of smooth muscle (sm) alpha-actin was studied in cloned capillary cerebral endothelial cells of two phenotypes. Type I cells were cultured in medium containing 10% FCS, heparin and ECGS (or alpha-ECGF) and stained positive for a specific endothelial cell marker (Bandeiraea simplicifolia). Depletion of heparin and ECGS resulted in a smooth muscle-like appearance after 2-3 days. Cells of this phenotype, (type II) stained positive for the endothelial cell marker and for sm alpha-actin. In contrast to type I cells, type II cells expressed sm alpha-actin protein and mRNA as evidenced by Immunoblots and Northern blots. This phenotypic switch was shown to be reversible and so was the expression of sm alpha-actin.

Actins↗
PubMed1991

[Optimized analgesic sedation techniques for ESWL].

Analgo-sedation for ESWL treatment has been associated with a variety of problems. Minimal invasiveness of this technique should combine with haemodynamic stability as well as with adequate oxygenation. Patient acceptance has to be considered as another important aspect. Our study demonstrates the effectiveness of an analgosedative regimen with regard to these aspects. 50 ASA I-III patients scheduled for ESWL treatment were randomly allocated to receive either no premedication (n = 25) or chlorazepam as oral premedication (n = 25). The analgosedative technique was identical in both groups, consisting of atropine 0.25 mg, droperidol 5 mg (2.5 mg, if body weight less than 60 kg), and alfentanil 10 micrograms/kg intravenously. If necessary, repeated boluses of alfentanil 5 micrograms/kg were administered up to a maximum of 2 mg. Heart rates, arterial blood pressures, and peripheral oxygen saturation were measured during treatment. Post-treatment, patients were interviewed to assess the quality of analgesia. The results showed that our analgo-sedative regimen is suitable for ASA I-III patients. Stable heamodynamic conditions and adequate oxygenation were achieved in all patients. Patient acceptance was good. Patients with anxiolytic premedication benefited in terms of reduction in blood pressure and heart rate. The study also showed that anaesthesiologists may underestimate the pain intensity experienced and assessed by the patient.

Aged↗
PubMed1991

Os trigonum syndrome: a clinical entity in ballet dancers.

Thirteen Swedish National classic ballet dancers were surgically treated for an "os trigonum syndrome."Their main symptom was an impingement pain in the hind foot while actively plantarflexing the ankle during ballet dancing. The surgical procedure included excision of an os trigonum or a prominent lateral posterior process of the talus, together with division of the flexor hallucis tendon sheath if it was thickened. This procedure was safe and resulted in return of the dancers to the same level of ballet dancing within 5 to 10 weeks.

Adolescent↗