Cycloadditionsreaktionen an Iminiumverbindungen

Cycloaddition Reactions of Iminium Compounds Iminium compounds 1 react in [2⊕ + 1]-cycloaddition reactions with the nucleophile carbene 2b , but not with methylene carbene (2a). On the other hand, 2a adds to the enamine 5. With 2,3-dimethylbutadiene (10) only less crowded carbiminium structures give products of a “Diels-Alder addition”.     

Septische Endarteriitis nach Angiographie

Zusammenfassung Infekti?se Komplikationen nach Angiographien sind selten. Bei einem 72-j?hrigen Patienten entwickelte sich nach Angiographie eine Staphylococcus aureus Sepsis mit Endarteriitis und gedeckter Ruptur der Arteria iliaca communis. Diagnostische Schwierigkeiten, Erregerspektrum und therapeutische M?glichkeiten werden diskutiert. Eingegangen: 23. Mai 2001 Akzeptiert: 6. September 2001     

Comparison of CD44 expression in early colorectal carcinomas of the de novo and ex adenoma types

Small colorectal carcinomas without morphological evidence of origin from an adenoma have been called ”de novo” carcinomas. As changes in the expression of the adhesion molecule CD44 and its variants have been described along the adenoma-carcinoma sequence in colorectal carcinoma, we compared patterns of CD44 expression in early de novo and ex-adenoma colorectal carcinomas by staining specimens from a group of early (pT1) colorectal carcinomas by immunohistochemistry for CD44 (standard and variant forms v3, v5, v6, v7, v7/8, v10). We evaluated carcinoma, adenoma (ex-adenoma cases), transitional mucosal areas and apparently nonneoplastic mucosa peripheral to the lesions (when present). A marked increase was seen in numbers and intensity of standard and variant forms of CD44 in carcinomatous areas compared with nonneoplastic mucosa in both groups, with no significant difference between the groups. However, adenoma areas of the ex-adenoma cases and the transitional mucosa of the de novo carcinomas had nearly identical staining patterns. Together with data from other molecular studies, this may be interpreted as evidence for an adenoma-type precursor lesion in so-called de novo colorectal carcinomas.     

A Physical Analog of the Failing Left Ventricle for In Vitro Studies of Mechanical Wall Actuation

Abstract: Mechanical repowering of a failing heart with devices or skeletal muscle could circumvent blood-pump lining problems. Requirements are complex: indefinite support with preservation of valve competence and coronary flow, avoidance of wall coaptation, and allowance of both rapid low impedance refilling and independent left and right pressures. An accurate in vitro physical failing-heart analog could facilitate the choice and screening of surgical and engineering approaches in mock circulation experiments. Prosthetic models, transplant recipient hearts, normal animal hearts, existing in vivo animal failure models, and failing cadaver hearts all have serious limitations. One hundred and four excised porcine hearts were dilated and fixed by three iterative protocols. Geometric and passive mechanical parameters were assessed and compared with targets expected for an end-stage failing heart. For Protocol 3, Subgroup 2 (reinforcing valve support, dilatation by compliant ventricular balloon, and ethyl alcohol fixation), the left ventricular shape and capacity (ellipsoid, 201–377 ml/500 g of heart weight), passive valve function, wall flexural rigidity ( Et ³ range 0.101-0.331 Nm), and refilling mechanics (99 ± 17.46 ml during 200–400 ms at ≤ 10 mm Hg transmural gradient) were all within goal criteria.     

Long-Term Ventricular Wall Actuation: Can and Should It Be Systematically Explored?

Abstract: Hearts fail because myocardial power fails. Assist, support, or replacement devices fail, at least in part, because their blood-contacting surfaces fail. Mechanical repowering of a failing heart might circumvent these difficulties by preserving a largely healthy endocardium while correcting the basic deficit, power. Any serious consideration of doing this though must confront some difficult requirements. Effective indefinite support must be coupled with preservation or restoration of valve competence, coronary flow, rapid low-impedance refilling and independent left and right pressures; the avoidance of wall coaptation; hardware that fits in the available space; and unless muscle powered, adaptability to a deliverable form of power. Despite earlier intense interest in acute mechanical devices and later empiric study of muscle wraps, little systematic methodical work has been done on elucidating and meeting these practical requirements. Concerted efforts toward developing research tools and techniques for their study and then finding mechanisms to meet them could well yield one or more effective modalities that circumvent a major obstacle to the indefinite mechanical treatment of heart failure     

Male breast cancer: Austrian experience

Data were collected on 169 men treated for breast cancer at 36 surgical departments in Austria between 1970 and 1991. We report here several of their clinical features and assess the importance of established prognostic factors. After a median observation period of 51 months 60 patients (35%) suffered a recurrence. The estimated 5-year recurrence-free survival for the entire group was 55%, and the estimated 5-year overall survival was 62%. Although stage-adjusted data are comparable to those for female breast cancer, the outcome in this series may be attributed to a relatively high frequency of advanced tumor stages. Tumor size (recurrence-free survival p=0.00001; overall survival p=0.03) and axillary lymph node status (recurrence-free survival p=0.0001; overall survival p=0.0001) proved to have a prognostic impact. Using a multivariate analysis, axillary lymph node status (recurrence-free survival p=0.001; overall survival p=0.01) still had prognostic influence. The various procedures used had no effect on local recurrence.

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Resumen Se recolectaron datos en 169 hombres tratados por cáncer mamario en 16 departamentos quirúrgicos de Austria en el período 1970 a 1991. En el presente estudio reportamos diferentes características clínicas y tratamos de definir la importancia de factores establecidos de pronóstico. Luego de un período promedio de observación de 51 meses, se observó recurrencia en 60 pacientes (35%). La tasa estimada de sobrevida libre de enfermedad recurrente para la totalidad del grupo fue 55% y la tasa estimada de sobrevida global a 5 años fue 62%. En tanto que la estadificación de los datos es comparable a la de las mujeres con cáncer mamario, el resultado final en esta serie puede ser atribuido a una frecuencia relativamente alta de tumor en estados avanzados. El tamaño del tumor (sobrevida libre de recurrencia p=0.0001; sobrevida global p=0.03) y estado de los ganglios axilares (sobrevida libre de recurrencia p=0.00001; sobrevida global p=0.0001) demostró tener impacto en cuanto al pronós neo. En el análisis multivariable, el estado de los ganglios linfáticos axilares (sobrevida libre de recurrencia p=0.0001; sobrevida global p=0.01) retuvo su influencia pronóstica. Los diferentes procedimientos operatorios de tratamiento local no demostraron efecto en cuanto a la recurrencia local.

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Résumé On a analysé les dossiers de 169 hommes traités pour un cancer du sein dans 36 centres chirurgicaux en Autriche entre 1970 et 1991. Les données cliniques ont été analysés et des facteurs pronostiques établis. Après une période d'observation médiane de 51 mois, 60 patients (35%) avaient une récidive. La survie à 5 ans sans maladie a été évaluée à 55% pour le groupe entier, alors que la survie à 5 ans globale a été de 62%. Lorsqu'on a comparé ces cas à des cancers de sein chez la femme, on s'est rendu compte que l'évolution dans cette série était peut-être en rapport avec un nombre plus important de stades avancés de patients avec cancer. On a démontré que la taille de la tumeur (survie sans récidive; p =0.0001; survie globale p=0.03) et l'état des ganglions axillaires (survie sans récidive p=0,00001, survie globale p=0,0001) avaient une valeur pronostique. En analyse multifactorielle, l'état ganglionnaire axillaire était toujours considéré comme facteur pronostique (survie sans récidive p=0.0001; survie globale p=0.01). Les interventions locales n'avaient aucune influence pronostique sur les récidives locales.

     

Ketamine interacts with the noradrenaline transporter at a site partly overlapping the desipramine binding site

Effects of the intravenous anaesthetic ketamine on the desipramine-sensitive noradrenaline transporter (NAT) were examined in cultured bovine adrenal medullary cells and in transfected Xenopus laevis oocytes expressing the bovine NAT (bNAT). Incubation (1–3 h) of adrenal medullary cells with ketamine (10–300 μM) caused an increase in appearance of catecholamines in culture medium. Ketamine (10–1000 μM) inhibited desipramine-sensitive uptake of [³H] _{noradrenaline} (NA) (IC₅₀=97 μM). Saturation analysis showed that ketamine reduced V _max of [³H]NA uptake without changing K _m, indicating a non-competitive inhibition. Other inhibitors of NAT, namely cocaine and desipramine, showed a competitive inhibition of [³H]NA uptake while a derivative of ketamine, phencyclidine, showed a mixed type of inhibition. Ketamine (10–1000 μM) also inhibited the specific binding of [³H]desipramine to plasma membranes isolated from bovine adrenal medulla. Scatchard analysis of [³H]desipramine binding revealed that ketamine increased K _d without altering B _max, indicating a competitive inhibition. In transfected Xenopus oocytes expressing the bNAT, ketamine attenuated [³H]NA uptake with a kinetic characteristic similar to that of cultured adrenal medullary cells. These findings are compatible with the idea that ketamine non-competitively inhibits the transport of NA by interacting with a site which partly overlaps the desipramine binding site on the NAT. Received: 18 December 1997 / Accepted: 17 June 1998     

Immunohistochemical Localization of Dopamine D Receptors in Rat Retina

We have localized the dopamine D1 receptor in rat retina using a subtype-specific monoclonal antibody. Immunolabelling can be detected in the inner and outer plexiform layers and in a number of cells in the inner nuclear layer. In the inner plexiform layer, labelled processes form four distinct horizontal bands and a series of patches. In order further to characterize the labelling pattern of the D₁ receptor antibody, double-labelling experiments were performed with antibodies against population-specific neuronal markers in the retina. Antibodies against tyrosine hydroxylase. choline acetyltransferase, calretinin, calbindin, the glutamate transporter GLT-I, protein kinase C, recoverin and parvalbumin were co-applied with the D, receptor antibody. With these cell markers we demonstrate that horizontal cells, at least three types of cone bipolar cells and a small number of amacrine cells are immunolabelled for the D1 receptor. In the inner plexiform layer, processes labelled by the D1 receptor antibody are co-stratified with processes labelled by the GLT-1 antibody. D₁ receptor-labelled processes are not co-localized with the processes of amacrine cells and ganglion cells labelled by antibodies against tyrosine hydroxylase, choline acetyltransferase or calretinin. Our results indicate that dopamine Dl receptors are localized predominantly to horizontal cells and cone bipolar cells. Furthermore, the spatial disparity between dopaminergic processes and the site of the majority of D1 receptors supports the idea that in the retina dopamine acts as a neuromodulator that diffuses through extracellular space. The localization of D1 receptors to a number of identified cell types enables future physiological work to be directed towards specific synaptic circuits within the retina.