Polymere ammoniumsalze aus N,N,N′,N′-tetramethylalkylendiaminen und N,N′-alkylenbis(chloracetamid)en

Long chain polymeric ammonium salts 3a–g and 4a were prepared in DMF/H₂O from N,N,N′,N′-tetramethylalkylenediamines 2a and 2b and N,N′-alkylenebis(chlorocetamide)s 1a–g . Some of them can be casted to clear transparent sheets. The chlorine atoms in 1a – g are activated by the adjacent carbonyl amino group. The polymer from N,N′-tetramethylenebis(chloroacetamide) ( 1d ) and N,N,N′,N′-tetramethylhexamethylenediamine (2b) shows an intrinsic viscosity of 61 ml/g, the highest value known for polyelectrolytes so far. The intrinsic viscosity decreases with increasing numbers of CH₂-groups in the monomers. The polymeric ammonium salts 3a – g and 4a give sheets from DMF solutions, which are soluble in water and stable under normal conditions. Polymers which are best suitable for the preparation of sheets show less hygroscopicity than the others, due to their structure. Intrinsic viscosities were calculated from the reduced specific viscosities measured in 0,4 _M KCl but may be also determined in water by the method of Yuan et al., plotting the reduced specific viscosities as a function of 1/√c.     

Epitope analysis with monoclonal antibodies directed against class II molecules subdivides HLA-DR2, DR3 and DR4: correlations with cellularly defined Dw specificities

Monoclonal antibodies (Mabs) defining 14 distinct polymorphic epitopes have been produced against the class II antigens of HLA-DR3Dw3DQw2 cells. Population analysis indicates that Mab C1 is directed against the DQw2 specificity and Mab M6 against the DRw52 specificity. The remaining Mabs define epitopes shared by the class II molecules of DR3 and various other specificities. Seven DR3Dw3DQw2 haplotypes were examined and could be divided into two types based on the presence of the epitope defined by Mab M3. Analysis of DR2 and DR4 homozygous cells with these Mabs revealed several distinct patterns of epitope expression. These subdivisions were found to correlate with the cellularly defined Dw specificities.     

Evaluation of the ERIC-PCR as a probable method to differentiate Avibacterium paragallinarum serovars

Infectious coryza, an upper respiratory tract disease in chickens, caused by Avibacterium paragallinarum, leads to huge economic losses. The disease is controlled through vaccination; but vaccination efficacy is dependent on correct identification of the infecting serovar, as limited cross-protection is reported amongst some serovars. Current identification methods include the heamagglutination inhibition test, which is demanding and could be subjective. To overcome this, molecular typing methods proposed are the Multiplex polymerase chain reaction (PCR) and Restriction Fragment Length Polymorphism-PCR, but low reproducibility is reported. Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR has been suggested for molecular groupings of various bacterial species. This study focuses on evaluating the ERIC-PCR as a probable method to differentiate between different Av. paragallinarum serovars by grouping with reference isolates, based on clonal relations. The ERIC-PCR was performed on 12 reference isolates and 41 field isolates originating from South Africa and South America. The data indicate that the ERIC-PCR is not ideal for the differentiation or for molecular typing of Av. paragallinarum serovars, as no correlation is drawn upon comparison of banding patterns of field isolates and reference strains. However, the results do indicate isolates from the same origin sharing unique banding patterns, indicating potential clonal relationship; but when compared to the reference isolates dominant in the specific area, no correlation could be drawn. Furthermore, although the ERIC-PCR serves a purpose in epidemiological studies, it has proved to have little application in differentiating amongst serovars of Av. paragallinarum and to group untyped field strains with known reference strains.     

Die Ultraviolett-Entkeimung von Flüssigkeiten geringer Strahlendurchlässigkeit

Ohne ZusammenfassungGekürzte Wiedergabe einer von der Fakultät für Maschinenwesen der Technischen Hochschule Karlsruhe genehmigten Dissertation.Die Arbeiten wurden durchgeführt im Tuberkulose-Forschungsinstitut Borstel (Direktor: Professor Dr. Dr. E.Freerksen).Dem Tuberkulose-Forschungsinstitut Borstel und seinem Direktor, Herrn Professor Dr. Dr. E.Freerksen, danke ich bestens, daß mir die Möglichkeit gegeben wurde, in Borstel die umfangreichen experimentellen Untersuchungen durchzuführen, die die Grundlage dieser Arbeit bilden. Ebenso danke ich den Siemens-Schuckertwerken, Erlangen, die die Arbeit dadurch förderten, daß sie Versuchsgeräte und Meßinstrumente zur Verfügung stellten.Schließlich danke ich den Herren Professor Dr. phil. P.Schulz und Professor Dr.-Ing. J.Kuprianoff, Karlsruhe, für die große Unterstützung, die sie mir als Referent bzw. Korreferent bei dem Promotionsverfahren gewährten.     

Cold-Knife Conization versus Loop Excision: Histopathologic and Clinical Results of a Randomized Trial

Ninety patients with cervical intraepithelial neoplasia (CIN) were randomly assigned to loop excision (n = 38) or cold-knife conization (n = 52). All specimens were well evaluable at histology. The average width of the lesions at histology was 10.2 and 9.7 mm, respectively (ns). The average weight of the specimens was 2.6 and 5.6 g (P < 0.01) and the average depth was 9.2 and 15.8 mm (P < 0.01), respectively. The distance between the cervical resection margin and CIN was 14 mm after loop excision and 24 mm after cold-knife conizatiun (P < 0.06). The margins of the specimen were not clear of disease in 8 patients after loop excision and in 12 patients after conization (ns). Two patients after loop excision and in three patients after cold-knife conization had postoperative bleeding. The results suggest that, compared with cold-knife conization, loop excision removes less healthy tissue without reducing the chances for cure.     

Chronic exposure to trichloroethylene affects neuronal plasticity in rat hippocampal slices

Inhalational exposure to organic solvents is known to exert neurotoxic effects. Using the new multielectrode dish system (Panasonic) the effects of chronic exposure to trichloroethylene (TCE) on neuronal plasticity were assessed in different regions of the adult rat brain. Two groups of Long-Evans rats were exposed to 0 ppm or 500 ppm TCE, respectively, 6 h/day, 5 days/week for 6 months. Long-term potentiation (LTP) as well as paired-pulse potentiation/inhibition were assessed in slices from the visual cortex and the hippocampus. In addition, several behavioral tests were performed. Trichloroethanol concentrations were measured in blood and trichloroacetic acid concentrations were determined in urine. While TCE exposure impaired LTP as well as paired-pulse potentiation in hippocampal slices, no effects were seen in cortical slices. Our data demonstrate brain region specific functional changes following TCE exposure with the hippocampus being more vulnerable than the visual cortex. The behavioral measurements revealed no TCE related effects.     

Synthese und Alkylierung von 10H-Pyrimido[5,4-b][1,4]benzothiazinen

Synthesis and Alkylation of 10H-Pyrimido[5,4-b][1,4]benzothiazines 10H-Pyrimido[5,4-b][1,4]benzothiazines 8 were prepared by condensation of barbituric acids 5 with 2-aminothiophenol (7) in DMSO via the ylide 6 . Compound 8 was characterized as a 1,5-dihydro system similar to the thia-isoalloxazines 1b . The structures of the alkyl derivatives isolated from a complex mixture were established by UV/VIS, ¹H-NMR, IR and ESR spectroscopy. They are discussed with regard to the alkylation of pyrimidobenzothiazines which carry substituents at N-10.