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Biomedical subjects

K Werner

Publications and source records attributed to K Werner.

At least 37 records · Page 2Linked to original sources

Natural history of a ventriculoatrial fistula after a gunshot injury in 1945.

We describe an exceptional case of a patient who suffered a penetrating heart injury from a gunshot wound in 1945 leading to a left ventricular-right atrial fistula. Despite the resulting left-to-right shunt the patient remained relatively asymptomatic for 50 years before the onset of congestive heart failure necessitated an operation.

Aged↗

Fish inner ear otolith size and bilateral asymmetry during development.

Size and bilateral asymmetry (i.e. size difference between the left and the right hand side) of inner ear otoliths of larval mouthbreeding cichlid fish were determined during the ontogenetic development of larvae from hatching to the free swimming stage. Animals of two batches were raised in aquarium hatch baskets. The basket containing one batch was placed directly above aeration equipment, resulting in random water circulation within the basket, which constantly shifted the specimens around ('shifted' specimens). The second batch of animals was raised in parallel without shifting. Due to the weight of the yolk-sacs, these animals lay on their sides until the yolk-sacs were resorbed ('stationary' specimens). The groups of larvae did not differ from one another in respect of individual general development, nor in otolith size. Contrasting results were obtained regarding bilateral otolith asymmetry: In both shifted and stationary animals, asymmetry of utricular and saccular otoliths (lapilli and sagittae, respectively) ranged at comparatively low values throughout development. However, by comparison with shifted individuals, lapillar asymmetry of stationary animals showed a highly significant increase during early development when larvae were forced to lay on their sides due to their prominent yolk-sacs. In later developmental stages, when they began to swim freely, a dramatic decrease in lapillar asymmetry was apparent. These findings indicate that development of lapillar asymmetry depends on the direction of the acting gravity vector relative to the positioning of the larvae, suggesting that the size (or mass) of a given otolith is regulated via a feedback mechanism.

Animals↗

Cytochrome P450 metabolites of arachidonic acid in human placenta.

Little is known about the epoxygenase pathway of the arachidonic acid cascade in uterine tissues. In this paper, we describe the formation of epoxyeicosatrienoic acids (EETs) and dihydroxyeicosatrienoic acids (DHETs) in human term placenta after uncomplicated pregnancies. Metabolism of [3H]-arachidonic acid was analyzed in short term tissue cultures of placenta by reverse phase HPLC. Major metabolites coeluted with authentic EETs and DHETs. The formation of EETs was inhibited by carbon monoxide. In non-radioactive incubations with biopsies from seven different placentas, sufficient material for GC/MS analysis was obtained. The combined media were purified by solid phase extraction and reverse phase HPLC. The fraction coeluting with DHETs was derivatized with pentafluorobenzylbromide (PFB) and bis-(trimethylsilyl)-trifluoroacetylacetamide (BSTFA) and analyzed by GC/NICI/MS/MS. 11, 12-DHET and 14, 15-DHET were identified by their mass spectra displaying specific fragments at m/z 149 and m/z 189, respectively. Our results suggest that the epoxygenase pathway is active in human term placenta.

8,11,14-Eicosatrienoic Acid↗

Arachidonate metabolism in human placenta, fetal membranes, decidua and myometrium: lipoxygenase and cytochrome P450 metabolites as main products in HPLC profiles.

Eicosanoids play a key role in pregnancy maintenance and parturition. We investigated the metabolism of arachidonic acid (AA) in short-term tissue cultures of placenta, fetal membranes, decidua and myometrium. Tissues were obtained from caesarean sections before the onset of labour after uncomplicated pregnancies. The released metabolites were analysed by high performance liquid chromatography (HPLC) and specific immunoassays. In radiotracer experiments tissues were labelled with [3H]-AA and metabolites released after incubation with calcium ionophore A23187 were profiled by HPLC. Decidua was more active in metabolizing AA (turnover 34 per cent) than myometrium (28 per cent), placenta (21 per cent) and fetal membranes (17 per cent). Main product in placenta, decidua and myometrium was 12-hydroxyeicosatetraeinoic (12-HETE) (decidua: 19 per cent of released radioactivity, myometrium 14 per cent, placenta 7 per cent). Fetal membranes formed 5-HETE as main product. Another major metabolite in placenta, fetal membranes and decidua was characterized by HPLC as 5(6)-epoxyeicosatrienoic acid. Only myometrium released appreciable amounts of prostaglandins in form of 6-keto-prostaglandin F1 alpha. In non-radioactive experiments formation of eicosanoids from endogenous AA was investigated by HPLC (fluorescence- and UV-detection) and immunoassays. These experiments confirmed the high production of 12-HETE and the low formation of prostaglandins. Our results suggest that the biological role of AA-metabolites, other than prostaglandins, have as yet been underestimated.

Arachidonic Acid↗

The standardized diagnosis of autism, Autism Diagnostic Interview-Revised: interrater reliability of the German form of the interview.

The feasibility and reliability of the German form of the revised parental interview to diagnose autism (Autism Diagnostic Interview-Revised, ADI-R) was investigated in this study. Brief examples of the description of formerly and currently used diagnostic guidelines are given and the outline of the interview algorithm which establishes thresholds for inclusion criteria. An excellent-to-good reliability could be demonstrated for the main symptoms according to the classification rules of the ICD-10 and DSM-IV for a sample of autistic subjects at different ages and intellectual levels. The results approve the use of this interview for research and clinical purposes.

Adolescent↗

[Typical configurations of psychosocial stress factors of psychiatrically conspicuous children and adolescents].

Typical configurations of psychosocial stressors in children and adolescents with psychiatric disorders. Abnormal psychosocial situations are strongly associated with psychiatric disorders in children and adolescents. They are significant risk factors, and sometimes play a causative role. Information about such situations can therefore serve as a basis for planning and implementation of therapeutic interventions. Up till now, however, there has been little evidence for the specificity of the relationship between psychosocial factors and psychiatric disorders. Therefore, in the present study cluster analysis was used to group a psychiatric population of children and adolescents by typical configurations of psychosocial stressors, and the subjects in these clusters were then compared with regard to age, gender, psychiatric disorders and level of intelligence. Five clusters were formed, with qualitative and quantitative differences. One cluster consists of cases with various psychiatric disorders but few psychosocial stressors or none at all. In the other four clusters, "parental handicap, mental disorder or deviation" and "anomalous parenting situation" are variables of key importance as one of them occurs in each cluster, together with different combinations of other psychosocial factors. In the one cluster where both of the previously mentioned key variables occur all of the additional factors also occur.

Adolescent↗

Immunocytochemical localization of histone H4 in the chromatoid body of rat spermatids.

Histone H4 could be localized in rat spermatids using immunocytochemistry with a monoclonal histone-H4-antibody (IgM mouse) in combination with a goat-anti-mouse-antibody labeled with 6 nm gold particles. Label was found in spermatids from step 2 to step 9 in the nucleus predominantly near its envelope and in the electron-dense material of the chromatoid body. In later spermatids, where the chromatoid body had disappeared, gold particles were still seen in the nucleus but now evenly distributed over the condensed chromatin. In the controls without primary antibody both the nucleus and the chromatoid body were unlabeled. The results suggest that the chromatoid body might play a role in the nuclear protein transition during spermiogenesis.

Animals↗

[The intelligence structure of autistic persons].

In a research project on the genetics of autistic disorders 115 subjects were examined. An autistic disorder was diagnosed in 102 of the subjects using the standardized Autism Diagnostic Interview (ADI; Le Couteur et al., 1989/ADI-R; Lord et al., 1994). The WAIS-R or WISC-R could be administered to 42 of the subjects. The mean full-scale IQ was 84.4, slightly below the range of normal intelligence. The mean verbal IQ (89.3) was considerably higher than the performance IQ (78.9). Analysis of the subtest patterns showed the highest scores to be in those subtests measuring knowledge of dates and facts and visuospatial abilities. The lowest scores were on subtests requiring an understanding of social relations and the ability to understand concrete social actions. This subtest pattern confirms results of other studies on the intelligence of individuals with autism and was independent of gender and level of intelligence. The subtest pattern appears to be specific for autistic disorder; it has been interpreted with reference to the theory of "weak central coherence" (Frith, 1989; Shah & Frith, 1993), which postulates that in autistic individuals stimulus perception and processing occurs independently of the general context. The results suggest that the differentiation between different types of autistic disorders should be abandoned in favor of a continuum of autistic disorders with differing degrees of severity.

Adolescent↗

[Acquired heart valve defects. Diagnostic and therapeutic strategies].

BACKGROUND: Diagnostic and therapeutic strategies in patients with acquired valvular heart disease, are determined by clinical symptoms, hemodynamics and empirical information. DIAGNOSIS: A quantitative assessment of cardiac disease can made largely on the basis of echocardiography or Doppler echocardiography with consideration also being given to the results of clinical findings. As a rule, cardiac catheterization should be done only once, immediately prior to operation. OUTLINE OF THERAPY: In chronic mitral and aortic valve insufficiency, the surgical indication is based primarily on the clinical symptoms, while in aortic and mitral valve stenosis, it is based primarily on the hemodynamic findings. Promising interventional procedures such as balloon valvuloplasty, represent useful alternatives to valve replacement in the case of mitral valve stenosis alone. In the event of significant aortic valve stenosis alone. In the event of significant aortic valve stenosis, balloon valvuloplasty is not a promising procedure. In patients with aortic or mitral valve insufficiency, but normal left ventricular function, medical treatment should first be attempted.

Catheterization↗

Comparison of tests for detection of methicillin-resistant Staphylococcus aureus in a clinical microbiology laboratory.

By microdilution testing, 186 of 1,450 clinical isolates of Staphylococcus aureus were preliminarily classified as oxacillin resistant (MIC > or = 4 micrograms/ml); 15 of these isolates gave conflicting results by alternative methods and were studied further. Only 2 of these (MIC > 4 micrograms/ml) were mecA positive; 13 were inhibited by oxacillin at 4 micrograms/ml. Significant numbers of S. aureus strains classified as resistant with an oxacillin MIC of 4 micrograms/ml may prove susceptible by other methods.

Base Sequence↗

[Pericardial lipoma as the cause of extensive mediastinal space-occupying lesion].

Lipomas of the heart are benign neoplasias and have rarely been described. Due to the fact that they normally cause no symptoms, diagnosis is often purely accidental. In the current report, the case of a 55-year-old patient is described in whom serial chest x-rays showed massive, progressive cardiac enlargement. Echocardiography and NMR showed a large pericardial mass confirmed by subsequent surgery which revealed a giant pericardial lipoma.

Diagnosis, Differential↗

Chromosomal localization and genomic cloning of the mouse alpha-tropomyosin gene Tpm-1.

In vertebrates, the alpha-tropomyosin gene, Tpm-1, codes for at least 9 tropomyosin isoforms that are expressed by tissue-specific alternative splicing. Using interspecies backcrosses, we have localized Tpm-1 on mouse chromosome 9, cen-Cyp1a2-Tpm-1-Mod-1-Mylc-Scn5a, near the d-se region. The restriction fragment length variant used for chromosomal assignment, as well as other restriction fragments hybridizing to a 3'-specific alpha-tropomyosin cDNA probe in genomic Southern blots, was investigated by cloning 17.5-kb of Tpm-1. The same restriction patterns were observed, proving the identity of the mapped and the cloned gene. The identity was supported by sequencing the 3' end of the gene.

Animals↗

Inactivation of HIV infectivity by the chlorite-oxygen reaction product tetrachlorodecaoxygen.

OBJECTIVE: Since the chlorite-oxygen reaction product tetrachlorodecaoxygen (TCDO) anion complex promotes efficaciously tissue repair and has antibacterial activity, our aim was to determine the effects of TCDO on the replication of HIV and on the infectivity of free HIV particles. DESIGN: The effects of TCDO on cellular HIV replication machinery and the consequences of TCDO for infectivity of HIV virions were evaluated. METHODS: Virus yields in supernatants of TCDO-supplemented cultures of HIV-infected cells or virus infectivity in TCDO-treated virus stocks were quantified by titration assays and then calculating the 50% tissue culture infectious dose. RESULTS: First, TCDO did not affect the replication of HIV in persistently infected lymphocytic and monocytic cell lines or in peripheral blood mononuclear cells. Second, supplementation of HIV stocks with TCDO markedly decreased the infectivity of HIV particles in a concentration dependent manner. Third, the binding of gp120 envelope glycoprotein of HIV-1 to cells is blocked by pre-incubation with TCDO. Fourth, the inhibition of HIV replication by the reverse transcriptase inhibitor 3'-azido-3'-deoxythymidine (zidovudine) in de novo infected cell cultures was not affected by the simultaneous addition of TCDO. However, the delayed virus spread of HIV in cultures in the presence of suboptimal concentrations of zidovudine could significantly be blocked by the simultaneous addition of TCDO. Fifth, TCDO failed to induce the chromosomally integrated HIV-1 provirus in the T-lymphoma cell line ACH2. CONCLUSIONS: TCDO appears to inactivate HIV particles directly, but has no influence on the intracellular replicative machinery of HIV. Our results suggest that a clinical evaluation of the TCDO complex as chemotherapy for HIV infection and full-blown AIDS should be considered, particularly in patients concomitantly receiving zidovudine.

Antiviral Agents↗