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Biomedical subjects

A Müller

Publications and source records attributed to A Müller.

At least 307 records · Page 17Linked to original sources
PubMed1997

[Aqueductal stenosis and hydrocephalus in a psychotic adolescent].

Examination of a 14-year-old male who was admitted to an inpatient unit with an acute paranoid syndrome yielded serious organic findings: macroencephaly, head tilted to one side, strabismus, neurological deficits, hydroencephaly and an expressive speech disorder. The personal and family history revealed a disturbance of motor development since infancy and psychiatric illness in the immediate family. The medication and the surgical procedure selected--endoscopic third ventriculostomy--are described and the difficult differential diagnosis is discussed.

Adolescent↗
PubMed1996

Receptor binding and internalization of a water-soluble (1-->3)-beta-D-glucan biologic response modifier in two monocyte/macrophage cell lines.

Glucan phosphate, a water-soluble, chemically defined (1-->3)-beta-D-glucan biologic response modifier, has been reported to exert antisepsis activity and accelerate wound healing. In this study we describe the specific binding of glucan phosphate to human and murine monocyte/macrophage cell lines, U937 and J774A.1, respectively. At 37 degrees C, equilibrium binding was rapidly achieved, i.e., within 1 min. In U937 cells, binding occurred with an affinity (Kd) of 37 microM and a Bmax of 65 x 106 binding sites/cell at 37 degrees C. In J774A.1 cells, glucan phosphate bound with an affinity (Kd) of 24 microM and a Bmax of 53 x 106 binding sites/cell at 37 degrees C. In both cases there was insignificant nonspecific binding. We further demonstrated that bound glucan phosphate cannot be displaced by a 50-fold excess of unlabeled ligand, suggesting internalization of glucan phosphate. Transmission electron microscopy showed significantly increased cytoplasmic vacuolization and significantly decreased mitotic activity in glucan phosphate-treated U937 cells compared with that in untreated cells. Pullulan, a random coil alpha-(1-->4)-(1-->6)-linked glucose polymer that served as a control, did not compete for the same binding site as glucan phosphate in either cell line, indicating the specificity of the binding site for (1-->3)-beta-D-glucans. We conclude that water-soluble pharmaceutical grade (1-->3)-beta-D-glucan phosphate specifically binds to and is internalized by U937 and J774A.1 cells.

Animals↗
PubMed1996

Lys-plasminogen as an adjunct to local intra-arterial fibrinolysis for carotid territory stroke: laboratory and clinical findings.

To improve the efficacy of local intraarterial fibrinolysis (LIF), we compared different fibrinolytic drugs in a cerebral circulation model in the laboratory. The technical efficacy of fibrinolysis, defined as the clot volume lysed per unit time, was found to be optimal with r-tissue plasminogen activator (TPA) activated lys-plasminogen (= plasmin). Subsequently, 20 patients with stroke due to carotid artery territory occlusion were treated by local intraarterial fibrinolysis using the plasmin regimen. The angiographic data and clinical outcome of these patients were compared with those of 40 patients who received plasminogen activators (urokinase or r-TPA) only. Laboratory and clinical data confirmed that plasmin lysis is superior to treatment using only plasminogen activators.

Carotid Artery Thrombosis↗
PubMed1996

Quantitative analysis of pyridinium crosslinks of collagen in the synovial fluid of patients with rheumatoid arthritis using high-performance liquid chromatography.

The pyridinium crosslinks are important and definite biomarkers of mature hard tissue collagen degradation. A gradient ion-paired reversed-phase high-performance liquid chromatographic method was used for the simultaneous determination of both crosslinks in synovial fluid (SF) samples of 25 patients with rheumatoid arthritis (RA). The mean +/- SD levels of pyridinoline (Pyd) and deoxypyridinoline (Dpyd) in SF were 107.7 +/- 182.3 nmol/l and 4.8 +/- 8.3 nmol/l, respectively. The Pyd/Dpyd ratio, which indicates the amount of Pyd released from cartilage rather than bone, amounted to 30.8 +/- 29.5. This value is significantly higher than in urine or serum of the same patients. These data suggest increased destruction of joint cartilage in patients with RA and the release of collagen II fragments in SF. In addition, the levels of the crosslinks in SF reflect considerable interindividual variation, indicating substantial individual differences in the amount of collagenous material that is degraded.

Adolescent↗
PubMed1996

Reverse transcription-polymerase chain reaction (RT-PCR) assays of estrogen and progesterone receptors in breast cancer.

The biochemical assay for estrogen (ER) and progesterone receptors (PR) as a routine procedure in the clinical evaluation of human breast cancer is well established. Since there are various and complex phenotypic alterations in breast cancer, there is a need for a multiparametric assessment of the biological profile of breast tumours. However, multiparametric analysis requires a large amount of tissue and various methods of quantitative analysis involving expensive reagents. Thus, an evaluation of the diagnostic and prognostic applications of the measurement of mRNA expression by reverse transcription polymerase chain reaction (RT-PCR) has been initiated. A series of 105 surgical samples of breast cancer was assayed for ER and PR expression in parallel by semi-quantitative RT-PCR and standardized enzymoimmunoassays (EIA). 79 (75%) tumour samples were positive for ER expression by EIA, and 86 (82%) by RT-PCR. This shows a good concordance of the two methods (90%). In the case of PR expression 65 (62%) tumour samples were positive by EIA and only 53 (51%) samples by RT-PCR. In conclusion ER-RT-PCR appears to provide information concerning ER expression similar to ER-EIA, and may be an alternative to this assay. The information derived by PR-RT-PCR appears somewhat different from PR-EIA. We are currently evaluating the biological and clinical significance of this discrepancy.

Adult↗
PubMed1996

Leg oedema protection from a buckwheat herb tea in patients with chronic venous insufficiency: a single-centre, randomised, double-blind, placebo-controlled clinical trial.

OBJECTIVES: The efficacy of a buckwheat herb tea was determined in patients with chronic venous insufficiency (CVI) in a single-centre, randomised, double-blind, placebo-controlled clinical trial. METHODS: Sixty-seven male and female patients (22-74 years) with CVI were randomly divided into two groups after a 2-week run-in period. They received either buckwheat herb tea (Fagopyrum esculentum) or a placebo tea for a period of 3 months. The main outcome measure was the lower leg volume determined by ultrasound. Subjective symptoms were assessed by a clinical symptom score system. The femoral vein diameters were measured by B-scan sonography. In a subgroup of patients capillary permeability was determined by cutaneous fluorescence angiography. RESULTS: Although the mean partial leg volume did not change in the treatment group (from 2041 to 2073 ml), it increased in the placebo group by 110 ml (from 1972 to 2082 ml) according to intent to treat. The difference between the groups was significant. The subjective clinical symptoms were significantly reduced in both groups. The mean diameters of the femoral veins were reduced and capillary permeability was improved, but neither change was statistically significant. No drug-related adverse effects were observed. CONCLUSION: CVI is a very placebo-sensitive condition. The treatment with buckwheat herb tea is safe and could have a favourable influence on patients with CVI such that further oedema development is prevented.

Adult↗
PubMed1996

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced dopaminergic denervation potentiates gabaergic inhibition in the mouse neostriatum in vitro.

Using the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine model of Parkinson's disease, we investigated the long-term effects of dopaminergic denervation on synaptic transmission in an in vitro slice preparation of the mouse neostriatum. In control mice, electrical stimulation elicited an antidromic potential (N1) followed by a synaptically mediated field potential (N2). In many slices, a third component (N3) was observed. Determination of the maximum stimulus intensities unveiled that in 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine-pretreated animals, the stimulus strength necessary to evoke a maximum N2 response was significantly higher compared to control mice. Furthermore, 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine-pretreatment led to a less frequent appearance and/or to a reduction in the amplitude of the N3 component. Application of glutamate receptor agonists and antagonists revealed two additional differences between normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-pretreated mice. (1) Comparison of the efficacy of the alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptor antagonist 6-cyano-7-nitroquinoxaline-2, 3-dione demonstrated an increase in the inhibitory effect of 6-cyano-7-nitroquinoxaline-2,3-dione in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-pretreated mice. (2) In normal mice, removal of magnesium ions from the bathing solution invariably led to the appearance of late N-methyl-D-aspartate receptor-dependent synaptic components. There components were only slightly expressed or virtually absent in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-pretreated mice. The described differences between the electrophysiological and pharmacological properties of evoked field potentials in slices from normal and 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine-pretreated mice disappeared following blockade of GABAA receptor-dependent inhibition by bicuculline. In normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-pretreated mice, bicuculline did not influence the amplitude of the N2 component, but invariably unmasked late synaptic components mediated by glutamate receptors. However, the potentiating effect of bicuculline was significantly stronger in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-pretreated mice compared to the controls. In the presence of bicuculline, the frequency of occurrence of the N3 component was identical in both groups. Furthermore, the apparent efficiency of 6-cyano-7-nitroquinoxaline-2,3-dione was no longer different. Application of bicuculline in the absence of magnesium ions resulted in a similar disinhibition of N-methyl-D-aspartate receptor-dependent late components as observed in the controls in the absence of bicuculline. The data demonstrate that chronic dopaminergic denervation reduces glutamate receptor-dependent synaptic excitation in the mouse neostriatum. Since differences between normal and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-pretreated mice disappear in the presence of bicuculline, we conclude that this reduction in excitability is due to a potentiation of GABAA receptor-dependent inhibition.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1996

Patients' internal world experience of interacting with psychiatric nurses.

Research was conducted to explore the patient's perception of interaction with psychiatric nurses. In-depth interviews were conducted with 13 psychiatric patients. The interviews were conducted in two phases. In phase 1 of each interview, the focus was exploratory and phenomenological, where a single central question was posed concerning the nature of a psychiatric patient's experience of interaction with psychiatric nurses. In phase 2 of each interview, the focus was to probe for further patient experience, based on the data elicited in phase one. The results of the research show significant findings within the psychological dimension of psychiatric patients' internal environment with specific reference to: their perception of the interaction (including stereotyping, custodialism, rule enforcement, lack of intimacy, friendliness, and lack of empathy and caring); defense mechanisms, identified during the interaction as denial and avoidance; and anxiety as emotion. These results emphasize the importance of a facilitative psychiatric nurse-patient interaction to assist the patient in the promotion, maintenance, and restoration of mental health.

Anxiety↗
PubMed1996

Transverse keratotomy to correct high corneal astigmatism after cataract surgery.

PURPOSE: To assess the outcome of transverse keratotomy to correct high corneal astigmatism after cataract surgery. SETTING: Vall d'Hebron Hospital, Department of Ophthalmology, Cornea and Refractive Surgery Unit, Barcelona Autónoma University, Spain. METHODS: Thirty-two eyes with regular corneal astigmatism between 2.50 and 5.00 diopters (D) after previous cataract surgery had two transverse incisions with an optical zone of 5.0 or 7.0 mm, a depth of 80 or 90%, and a length of 3.0 or 4.0 mm, depending on the amount of astigmatism and based on a personal nomogram we developed. RESULTS: From 80 to 100% of the desired correction was achieved in 38.7% of eyes and from 60 to 80% in 38.9%. At 6 months, only 9.1% had a keratometric change of more than 0.50 D. Best corrected visual acuity was the same or better in 85.2% of patients; no patient lost more than one Snellen line. CONCLUSION: This easy, safe technique had low anatomical and refractive morbidity and high efficacy, making it an excellent option for eyes with high astigmatism after cataract surgery. More research is required in view of the considerable unpredictability of our results and the disparity in methods and results of other published studies.

Astigmatism↗
PubMed1996

Transgenic tobacco plants expressing the Arabidopsis thaliana nitrilase II enzyme.

Nitrilase (E.C. 3.5.5.1) cloned from Arabidopsis thaliana converts indole-3-acetonitrile to the plant growth hormone, indole-3-acetic acid in vitro. To probe the capacity of ths enzyme under physiological conditions in vivo, the cDNA PM255, encoding nitrilase II, was stably integrated into the genome of Nicotiana tabacum by direct protoplast transformation under the control of the CaMV-35S promotor. The regenerated plants appeared phenotypically normal. Nitrilase II was expressed, based on the occurrence of its mRNA and polypeptide. The enzyme was catalytically active, when extracted from leaf tissue of transgenic plants (specific activity: 25 fkat mg(-1) protein with indole-3-acetonitrile as substrate). This level of activity was lower than that found in A. thaliana, and this was deemed essential for the in vivo analysis. Leaf tissue from the transgenic plants converted 1-[13C]-indole-3-acetonitrile to 1-[13C]-indole-3-acetic acid in vivo as determined by HPLC/GC-MS analysis. Untransformed tobacco was unable to catalyze this reaction. When transgenic seeds were grown on medium in the absence of indole-3-acetonitrile, germination and seedling growth appeared normal. In the presence of micromolar levels of exogenous indole-3-acetonitrile, a strong auxin-overproducing phenotype developed resulting in increased lateral root formation (at 10 microM indole-3-acetonitrile). Collectively, these data prove the ability of nitrilase II to convert low micromolar levels of indole-3-acetonitrile to indole-3-acetic acid in vivo, even when expressed at subphysiological levels thereby conferring a high-auxin phenotype upon transgenic plants. Thus, the Al thaliana nitrilase activity, which exceeds that of the transgenic plants, would be sufficient to meet the requirements for auxin biosynthesis in vivo.

Aminohydrolases↗
PubMed1996

Polymerase chain reaction for microsporidian DNA in gastrointestinal biopsy specimens of HIV-infected patients.

OBJECTIVE: To study the accuracy of polymerase chain reaction (PCR) for microsporidian DNA in gastrointestinal biopsy specimens of HIV-infected patients for the diagnosis of intestinal microsporidiosis. SETTING: Infectious disease in- and outpatient clinic of a university hospital in Cologne, Germany. PATIENTS: Forty-six HIV-infected patients with diarrhoea. METHODS: PCR and Southern blot hybridization were performed using DNA extracted from intestinal biopsy specimens with primers and probes from the small subunit rRNA gene of Enterocytozoon bieneusi and Septata intestinalis. Histological examination of intestinal biopsy specimens was performed using a fluorescence technique. Transmission electron microscopy of intestinal biopsy specimens was performed in 13 patients. RESULTS: Amplification and Southern blot hybridization with species-specific primers and probes gave positive results in 10 patients for E. bieneusi, and in 10 patients for S. intestinalis. Overall, five cases of double infection with E. bieneusi and S. intestinalis were seen when both primer pairs and probes were used. Histological examination showed microsporidian spores in all 15 cases, but light microscopy was unable to distinguish between species in almost all cases. CONCLUSIONS: PCR detection of microsporidian DNA in intestinal biopsy specimens can be used reliably for the diagnosis of intestinal microsporidiosis in HIV-infected patients and is also useful for species differentiation between microsporidia. Infections with S. intestinalis and double infections with two types of microsporidia appear to be more common than previously described.

AIDS-Related Opportunistic Infections↗
PubMed1996

Impaired pancreatic function in patients with Crohn's disease with and without pancreatic autoantibodies.

Pancreatic autoantibodies (PABs) are found in 31% of patients with Crohn's disease (CD), but they do not correlate with the activity of intestinal disease or the incidence of acute pancreatitis. Exocrine pancreatic insufficiency has been observed in patients with CD. The aim of our study was to correlate the occurrence of PABs with exocrine pancreatic function to explore the clinical significance of these antibodies. Serum samples of 64 patients with CD were tested for PABs by indirect immunofluorescence. In addition, all patients were tested for exocrine pancreatic insufficiency by a fluorescein dilaurate test. PABs were detected in 26 of 64 patients (40%). The PAB-positive and -negative groups did not differ in clinical characteristics, such as age, sex, involvement of intestine, previous surgical interventions, drug therapy, and disease activity. Seven of the antibody-positive patients (27%) had impaired pancreatic function, in contrast to three of 38 PAB-negative patients (8%) (p < 0.05). In conclusion, exocrine pancreatic function is impaired significantly more often in PAB-positive than in PAB-negative patients. A prospective follow-up is required to determine whether PAB-positive patients are more likely to develop pancreatic insufficiency later in their course of disease.

Adolescent↗