Antigenic and structural differences among six proteins II expressed by a single strain of Neisseria gonorrhoeae.

Gonococci express a family of related outer membrane proteins designated protein II (P.II), which undergo both phase and antigenic variation. Six P.II proteins have been identified in strain FA1090. We developed monoclonal antibodies specific for each P.II protein. Using these antibodies as probes, we purified the six different P.II proteins of this strain. Despite the relatedness of the proteins, we could not purify all of them by a single purification scheme. Four P.II proteins were purified by chromatofocusing, and the remaining two proteins were purified by hydrophobic interaction chromatography on phenyl-Sepharose. The N-terminal amino acid sequence of the proteins showed a high degree of sequence conservation. However, there was variability at specific amino acid residues, giving each P.II protein a unique N-terminal amino acid sequence. Thus P.II proteins of one strain differ among themselves not only in antigenic determinants and primary structure, but also in other characteristics affecting their properties in different chromatographic systems.     

Methylator phenotype of malignant germ cell tumours in children identifies strong candidates for chemotherapy resistance

Background:

Yolk sac tumours (YSTs) and germinomas are the two major pure histological subtypes of germ cell tumours. To date, the role of DNA methylation in the aetiology of this class of tumour has only been analysed in adult testicular forms and with respect to only a few genes.

Methods:

A bank of paediatric tumours was analysed for global methylation of LINE-1 repeat elements and global methylation of regulatory elements using GoldenGate methylation arrays.

Results:

Both germinomas and YSTs exhibited significant global hypomethylation of LINE-1 elements. However, in germinomas, methylation of gene regulatory regions differed little from control samples, whereas YSTs exhibited increased methylation at a large proportion of the loci tested, showing a ‘methylator'' phenotype, including silencing of genes associated with Caspase-8-dependent apoptosis. Furthermore, we found that the methylator phenotype of YSTs was coincident with higher levels of expression of the DNA methyltransferase, DNA (cytosine-5)-methyltransferase 3B, suggesting a mechanism underlying the phenotype.

Conclusion:

Epigenetic silencing of a large number of potential tumour suppressor genes in YSTs might explain why they exhibit a more aggressive natural history than germinomas and silencing of genes associated with Caspase-8-dependent cell death might explain the relative resistance of YSTs to conventional therapy.     

An assessment of endocrine function in boys with Perthes' disease

The frequent association of short stature and retardation of skeletal maturation in Perthes' disease has prompted an investigation of growth-related hormones in this condition. A group of 18 prepubertal boys, aged five to 11 years, who either had a bone age two years or more less than their chronologic age or whose heights were less than the third centile, were studied. Their serum growth hormone (Se GH) response to insulin-induced hypoglycemia was significantly reduced, compared with a control group of short boys. They also demonstrated a tendency to elevated levels of somatomedin activity, measured by chick cartilage bioassay. Thyroid function was normal. These findings suggest a defect in the pituitary-somatomedin-target tissue axis in Perthes' disease.     

Die subcutanen Injectionen des Alkohols und ähnlich wirkender Stoffe bei Erkrankungen der Blutgefässe

Ohne Zusammenfassung     

Über die Definition des Begriffs „Mißbildungen”

Ohne Zusammenfassung     

Über die Schafferschen Magenschleimhaut-inseln der Speiseröhre

Ohne ZusammenfassungOberarzt im Feldart.-Regt. No. 20, früher kommandiertem Assistenten der Abteilung, jetzt kommand. Assistenten a. d. chirurg. Universitätsklinik in Bonn. (Mit 2 Textfiguren.)