No evidence for a correlation between behaviour and the size of the Y chromosome

Y chromosome variation has been studied in three groups of Norwegian males: 35 boys from an adolescent psychiatric hospital; 45 men from a hospital for hard-to-manage or dangerous, psychotic men; and 26 boys from two ordinary school classes.
Y chromosomes with 1, 2, and 3 brightly fluorescing bands were found in all three groups. One boy carried a Y with no bands. The mean values of the Yf/Yq ratio were not significantly different in the three groups (Yf is the length of the distal, brightly fluorescing part of Yq). Two cases of XY/XYY mosaicism were found among the psychotic men.
The study shows that the human species is polymorphic with regard to the size of the Y chromosome, i. e. the number of fluorescent bands in the long arm. No phenotypical manifestation of this polymorphism, particuIarly as regards behaviour, was found.     

Transformation of the cultivated mushroom Agaricus bisporus (Lange) using T-DNA from Agrobacterium tumefaciens

Agrobacterium tumefaciens is known to transfer parts of its tumor-inducing plasmid, the T-DNA, to plants, yeasts and filamentous fungi. We have used this system to transform germinating basidiospores and vegetative mycelium of a commercial strain of the cultivated basidiomycete Agaricus bisporus. Analysis of transformants shows that the T-DNA integrates at random sites into the host genome and that the selection marker is stable during mitosis and meiosis. The Agrobacterium system allows the transformation of both homokaryons and heterokaryons of A. bisporus. Also, both karyotypes of an heterokaryon can be transformed simultaneously. Furthermore, this is the first report on the transformation of vegetative mycelium of a commercial strain of A. bisporus. Received: 6 June 2000 / Accepted: 10 October 2000     

Ultrastructural pathology of aortic dissections in patients with Marfan syndrome: Comparison with dissections in patients without Marfan syndrome.

Despite the discovery in 1990 that mutations in the fibrillin-1 gene cause the Marfan syndrome, the pathogenesis of the life-threatening dissections associated with this disease is far from elucidated. Both the massive number of known fibrillin-1 mutations that result in a heterogeneous patient population and the strongly heterogeneous histology of patients' aortae presumably contribute to this lack of knowledge. We performed a detailed ultrastructural immunoelectron microscopic and histochemical analysis of the dissected media of ascending aortae of 10 patients with Marfan syndrome and compared them with those of 6 patients without Marfan syndrome and 77 individuals without known aortic disease. Relatively similar abnormalities were found in both patient groups, although they were more numerous and more diffusely spread in the patients with Marfan syndrome than in the patients without Marfan syndrome. The most conspicuous ultrastructural defects were the formation of abrupt transverse tears in thick and compact elastic lamellae and the local breaking up of smooth muscle cell-elastic lamella connections (that largely consist of microfibrils and elastic extensions, protruding from the elastic lamellae). This breaking up was characterized by a strongly reduced number of microfibrils and a severe shortening of the elastic extensions. Finally, the elastic extensions detached from the lamellae to ultimately degenerate and disappear. These changes were found mainly in the oldest group of patients with Marfan syndrome, indicating that they represented a loss of previously normally developed structures. We also compared our findings with those from a recently developed murine Marfan model (Pereira L, Lee SY, Gayraud B, Andrilopoulos K, Shapiro SD, Bunton T, Biery NJ, Dietz HC, Sakai LY, Ramirez F. Pathogenetic sequence for aneurysm revealed in mice underexpressing fibrillin-1. Proc Natl Acad Sci. U. S. A. 1999: 96: 3819-3823). Next to similarities, several striking differences existed, demonstrating that this model is not fully representative of the human Marfan syndrome.     

Über die Feinstruktur eines vom Pferd isolierten Virus der Herpesgruppe

Summary A virus isolated from horses after abortion was propagated in cultures of swine kidney cells. Shape and structure of the virus particles as seen in negatively stained preparations and changes observed in ultrathin sections of infected cells suggest that the virus belongs to the herpes group. However, most of the virus particles in the nucleus and in the cytoplasm have a structure different from that of herpes virus. Instead of the nucleoid, vesicle-like formations are arranged in the particle, so as to produce a cross-shaped light area in the center of the particle.

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Für wertvolle technische Mitarbeit danken wir FräuleinAdele Boroni.     

In ovarian neoplasms, BRAF, but not KRAS, mutations are restricted to low-grade serous tumours

Genes of the RAF family, which mediate cellular responses to growth signals, encode kinases that are regulated by RAS and participate in the RAS/RAF/MEK/ERK/MAP-kinase pathway. Activating mutations in BRAF have recently been identified in melanomas, colorectal cancers, and thyroid and ovarian tumours. In the present study, an extensive characterization of BRAF and KRAS mutations has been performed in 264 epithelial and non-epithelial ovarian neoplasms. The epithelial tumours ranged from adenomas and borderline neoplasms to invasive carcinomas including serous, mucinous, clear cell, and endometrioid lesions. It is shown that BRAF mutations in ovarian tumours occur exclusively in low-grade serous neoplasms (33 of 91, 36%); these included serous borderline tumours (typical and micropapillary variants), an invasive micropapillary carcinoma and a psammocarcinoma. KRAS mutations were identified in 26 of 91 (29.5%) low-grade serous tumours, 7 of 49 (12%) high-grade serous carcinomas, 2 of 6 mucinous adenomas, 22 of 28 mucinous borderline tumours, and 10 of 18 mucinous carcinomas. Of note, two serous borderline tumours were found to harbour both BRAF and KRAS mutations. The finding that at least 60% of serous borderline tumours harbour mutations in two members of the ERK-MAP-kinase pathway (BRAF 36%, KRAS 30%) compared with 12% of high-grade serous carcinomas (BRAF 0%, KRAS 12%) indicates that the majority of serous borderline tumours do not progress to serous carcinomas. Furthermore, no BRAF mutations were detected in the other 173 ovarian tumours in this study.     

Inhibition of mast cell histamine release by flavonoids and biflavonoids

The effect of 11 flavonoids and 4 biflavonoids on the release of histamine from peritoneal rat mast cells induced by compound 48/80 and calcium ionophore A23187 was studied. Dihydroflavonoids (flavanones) and (+)-catechin did not modify histamine release induced by both secretagogues. Flavone, apigenin and cromoglycate inhibited the secretion elicited by compound 48/80 but did not modify the A23187-induced secretion. The effect of kaempferol on the compound 48/80-induced histamine release was biphasic. Low doses (10 (-6) to 10 (-5)M) of the compound potentiated secretion whereas higher doses inhibited histamine secretion. Some of the drugs tested revealed a higher potency as referred to quercetin. Luteolin, a tetrahydroxyflavone and amentoflavone, a biapigenin, exhibited the highest inhibitory effects of mast cell histamine secretion.     

Evaluation and improvement of homovanillic acid methodology, and a critique of liquid chromatography with electrochemical detection

Resolution of several problems encountered with some organic solvent extraction-fluorometric procedures commonly used to measure homovanillic acid (HVA) in urine resulted in a more specific and sensitive methodology, applicable to diverse biological material. Purification on an anion-exchange resin followed by extraction with organic solvent was the most reliable and specific for HVA. Eluting the resin with a near-boiling solution of NaCl concentrated the HVA in a smaller volume with no increase in the blank reading. In none of the other methods was enough oxidizing agent used to completely oxidize the excessive amounts of HVA in urines of patients with neuroblastoma. 5-Hydroxyindoleacetic acid interferes with the HVA fluorophor. Several of the advantages and problems with "high-pressure" liquid chromatography with electrochemical detection are identified, particularly the unpredictable nature of the working electrode.