The white spot syndrome virus DNA genome sequence.

White spot syndrome virus (WSSV) is at present a major scourge to worldwide shrimp cultivation. We have determined the entire sequence of the double-stranded, circular DNA genome of WSSV, which contains 292,967 nucleotides encompassing 184 major open reading frames (ORFs). Only 6% of the WSSV ORFs have putative homologues in databases, mainly representing genes encoding enzymes for nucleotide metabolism, DNA replication, and protein modification. The remaining ORFs are mostly unassigned, except for five, which encode structural virion proteins. Unique features of WSSV are the presence of a very long ORF of 18,234 nucleotides, with unknown function, a collagen-like ORF, and nine regions, dispersed along the genome, each containing a variable number of 250-bp tandem repeats. The collective information on WSSV and the phylogenetic analysis on the viral DNA polymerase suggest that WSSV differs profoundly from all presently known viruses and that it is a representative of a new virus family.

Homologues of a single resistance-gene cluster in potato confer resistance to distinct pathogens: a virus and a nematode.

The isolation of the nematode-resistance gene Gpa2 in potato is described, and it is demonstrated that highly homologous resistance genes of a single resistance-gene cluster can confer resistance to distinct pathogen species. Molecular analysis of the Gpa2 locus resulted in the identification of an R-gene cluster of four highly homologous genes in a region of approximately 115 kb. At least two of these genes are active: one corresponds to the previously isolated Rx1 gene that confers resistance to potato virus X, while the other corresponds to the Gpa2 gene that confers resistance to the potato cyst nematode Globodera pallida. The proteins encoded by the Gpa2 and the Rx1 genes share an overall homology of over 88% (amino-acid identity) and belong to the leucine-zipper, nucleotide-binding site, leucine-rich repeat (LZ-NBS-LRR)-containing class of plant resistance genes. From the sequence conservation between Gpa2 and Rx1 it is clear that there is a direct evolutionary relationship between the two proteins. Sequence diversity is concentrated in the LRR region and in the C-terminus. The putative effector domains are more conserved suggesting that, at least in this case, nematode and virus resistance cascades could share common components. These findings underline the potential of protein breeding for engineering new resistance specificities against plant pathogens in vitro.

[Iatrogenic hydrothorax in a premature infant and its treatment]. / Iatrogener Hydrothorax bei einem Frühgeborenen und seine Behandlung.

Iatrogenic hydrothorax in a premature infant of 36 weeks' gestation was caused by misplacement of a central venous catheter leading to massive pleural effusion in the left hemithorax. Subsequently respiratory insufficiency developed which could be treated successfully within 24 h by complete removal of the i.v. fluid via the misplaced catheter and simultaneous mechanical ventilation.

[Automated cytofluorometry of solid malignant tumors after cell dispersal by means of intraperitoneal cultivation of cell complexes in young rats (author's transl)]. / Automatische Zytofluorometrie solider Malignome nach Zellenvereinzelung durch intraperitoneale Anzucht von Zellkomplexen in jungen Ratten

UNLABELLED: The use of isolated cells is a basic requirement besides data processing techniques to obtain optimum results with the automated flow cytofluorometry. Several techniques have been employed in order to get cell dispersal. But the claim for reproducible and representative cell samples cannot exactly be fulfilled: gross parts of cells are damaged by any dispersal method applied on solid tissues. Therefore we want to introduce a special method for cell isolation, which avoids mechanical and chemical damage of the treated cells. For this the intraperitoneal tolerance of growing tumor cells in young animals was used, in the species of which solid growth of such tumor cells is established. The investigations reported here were carried out with the Walker-tumor 256 on the rat as a model for solid tumor growth. Our interest was focused on the determination of cellular CNA distribution in tumor cells and contaminating somatic cells grown in the ascitic fluids. MATERIAL AND METHODS: Walker-tumors are permanently cultivated on Sprague-Dawley rats. The solid tumors (1 cm diameter) were removed under sterile conditions, cut with scissors, and resuspended in 0.9% saline. Ten rats (37 days old, body weight 90-120 g) had received an intraperitoneal injection of 1 ml Liquemin (5000 Roche). One million tumor cells could be obtained by such a procedure. After spontaneous sedimentation of cells in order to reduce the number of erythrocytes, the cells were processed and fixed according to Trujillo and Van Dilla (1972), digested with heated RNase (1 mg/ml tris-buffer; 0.18 M and pH 7.5), pepsin treated, and then stained with ethidium bromide (40 mug/ml tris-buffer) for 30 min in the cold. After rinsing with distilled water several times the cells were resuspended in buffer and measured within an hour immediately after passing a 10 mum filter to avoid cell aggregates...