Sequence analysis of the gene coding for glyceraldehyde-3-phosphate dehydrogenase (gpd) of Podospora anserina: use of homologous regulatory sequences to improve transformation efficiency

Summary The glyceraldehyde-3-phosphate dehydrogenase (gpd) gene of Podospora anserina has been isolated from a genomic library by heterologous hybridization with the corresponding gene of Curvularia lunata. The coding region consists of 1014 nucleotides and is interrupted by a single intron. The amino-acid sequence encoded by the gpd gene shows a high degree of sequence identity with the corresponding gene products of various fungi. Multiple alignments of all fungal GPD sequences so far available resulted in the construction of a phylogenetic tree. The evolutionary relationships of the various fungi belonging to different taxa will be discussed on the basis of these data. Sequence analysis of 1.9 kbp of the 5 non-coding region revealed the presence of typical fungal promoter elements. Utilizing different parts of the 5 regulatory sequence of the Podospora gpd gene, expression vectors containing a dominant selectable marker gene (hygromycin B phosphotransferase) have been constructed for the transformation of P. anserina protoplasts. The use of these homologous gpd regulatory sequences resulted in a significant increase in transformation efficiencies compared to those obtained with vectors in which the selectable marker gene is under the control of the corresponding heterologous promoter of Aspergillus nidulans.     

Bipolaris spicifera causes fungus balls of the sinuses and triggers polypoid chronic rhinosinusitis in an immunocompetent patient

We report the rare case of a 19-year-old immunocompetent male suffering both from fungus balls of the sinuses and from chronic rhinosinusitis with massive polyposis. Endoscopic sinus surgery revealed grayish brown necrotic masses embedded in viscous eosinophilic mucus. Inoculated onto petri dishes, these masses as well as the mucus grew a dark pigmented fungus, which was identified as Bipolaris spicifera.     

Prevalence of hepatitis-C virus RNA in serum and throat washings of children with chronic hepatitis

Serum samples from 46 children with chronic and probably transfusion acquired hepatitis were tested for the presence of hepatitis C virus (HCV) RNA by a “nested” polymerase chain reaction (PCR) assay, to judge a possible risk of HCV transmission from these patients. In 73% of the samples, viral RNA was detected, indicating a high virus prevalence in this patient group. High titers of HCV-RNA were observed in some sera as shown by the detection of virus in some samples even at dilutions of 10^?3. Comparison of simultaneously obtained PCR results and ALT values revealed no significant correlation between virus presence in serum and higher ALT levels. It was, however, shown that unusually high ALT values may reflect a high titer of viral RNA in serum. To investigate the prevalence of viral RNA in saliva, which could be a vehicle of virus transmission, 35 throat washing samples from the HCV-infected children were screened by PCR. Using three different sample preparation procedures, 20% of the throat washings were found to be positive for HCV-RNA. This indicates a prevalence of virus in this fluid lower than that reported previously. © 1994 Wiley-Liss, Inc.     

Biological and clinical significance of cytogenetic abnormalities in low-risk and high-risk gastrointestinal stromal tumors

We report cytogenetic findings in 19 c-Kit-positive gastrointestinal stromal tumors (GISTs) that represent a heterogenous group of mesenchymal neoplasms with respect to site, histology, and biologic behavior. All of the GISTs (5 low-risk, 11 high-risk, 3 recurrences) displayed clonal chromosomal aberrations; 15 were hypo- to near-diploid, and 4 were near-triploid and hypotetraploid. The most common abnormalities were loss of chromosomes 14 and/or 22, demonstrated in 14 GISTs irrespective of site or predominant phenotype. Ten cases (2 low-risk, 5 high-risk, 3 recurrences) were characterized by loss of both chromosomes 14 and 22, 2 cases (1 low-risk, 1 high- risk), by loss of chromosome 14; and 2 high-risk cases, by loss of chromosome 22. Additional chromosomal aberrations occurred preferentially in high-risk and recurrent GISTs, including loss of 9p and 1p in 8 cases each, loss of 15 in 6 cases, loss of 3p in 5 cases, loss of 13q and 10q in 4 cases each, loss of 19 in 3 cases, and complete or partial gains of chromosomes 5 and 4 in 2 cases each. More significantly, 5 of 6 patients with clinically aggressive GISTs, including 2 recurrences and 3 metastasing GISTs, were additionally characterized by loss of 9p; four of these had additional loss of chromosomes 1p and 15. The presented results herein indicate that loss of chromosome 14 and/or 22 is an early change in GIST tumorigenesis irrespective of site or differentiation, whereas malignant transformation and progression of GISTs appear to be associated with an increasing incidence of additional secondary aberrations.     

Genotypic status of Babesia microti within the piroplasms

For resolution of the controversial taxonomic status of Babesia microti in relation to other Babesia and Theileria spp. a phylogenetic analysis of an American and a German B. microti strain was performed on the basis of sequences of the small-subunit rRNA gene (rDNA) using distance-matrix, maximum-parsimony, and maximum-likelihood algorithms. Both B. microti isolates clearly separated from a group containing other Babesia spp. as well as from a second group consisting of Theileria spp. Interestingly, the B. microti isolates clustered in a monophyletic group together with other piroplasm species of unclear taxonomic status, B. rodhaini, and a recently described small canine piroplasm species. These results support the existence of a third taxonomic entity of equal rank besides the Babesiidae and Theileriidae. Received: 11 February 2000 / Accepted: 24 February 2000     

Three mitochondrial unassigned open reading frames of Podospora anserina represent remnants of a viral-type RNA polymerase gene

The mitochondrial DNA of Podospora anserina is complex, consisting of a characteristic set of genes with a large number of introns and a substantial amount of sequence of unknown function and origin. In addition, as indicated by various types of reorganization, this genome is highly flexible. Here we report the identification of three unassigned mitochondrial open reading frames (ORF P', ORF Q', ORF 11) as remnants of a rearranged viral-type RNA polymerase gene. These ORFs are not transcribed and may be derived from the integration of a linear plasmid of the type recently identified in a mutant of P. anserina.     

HnRNP CBP35-CBP67 interaction during stress response and ageing

Previous studies have demonstrated the existence of nuclear carbohydrate binding proteins in a variety of mammalian cells with molecular masses of 35 000, 67 000, and 70 000 (CBP35, CBP67, and CBP70), which are associated with nuclear ribonucleoprotein (RNP) complexes. CBP35 consists of two domains, an aminoterminal portion that is homologous to certain regions of proteins of the heterogeneous nuclear RNP complex, and a carboxyl-terminal portion homologous to β-galactoside-specific lectins. CBP35 it has been proposed, like the glucose-specific lectin, CBP67, to guide RNP complexes through the nuclear pore. Here we show that the exposure of mature rats to stress induces an increase in nuclear CBP35 bound to CBP67 and retained on immobilized glucose. Nuclear extracts from the livers of old rats displayed no detectable stress response. This CBP35·CBP67 association detected in rat liver is considered with respect to the CBP35·CBP70 association recently observed in HL60 cell nuclear extracts.     

Licht- und elektronenmikroskopische Untersuchungen zur Histopathogenität vonMacracanthorhynchus hirudinaceus (Archiacanthocephala) in experimentell infizierten Hausschweinen

Zusammenfassung Die vonMacracanthorhynchus hirudinaceus verursachten Läsionen im Dünndarm von experimentell infizierten Hausschweinen (7 Tage p.i. und 84 Tage p.i.) wurden licht- und elektronenmikroskopisch untersucht. Die Würmer der 84 Tage alten Infektion waren tiefer in die Darmwand eingedrungen als die 7 Tage alten Würmer. Ihr Präsoma wurde von Entzündungsbzw. Bindegewebe umhüllt, das zahlreiche Plasmazellen enthielt. Bei 7 Tage alten Infektionen wurde noch keine Fibrose nachgewiesen. Eosinophilen-ähnliche Granulozyten, die an den Proboscishaken akkumulierten, herrschten in der Läsion vor. Eine osmiophile Gleitflüssigkeit, die offenbar an der Basis der Proboscishaken ausgeschieden wurde, schien eine stark antigene Wirkung auf die Leukozyten des Schweins auszuüben. In keinem Fall wurden Würmer angetroffen, die die gesamte Darmwand perforiert hatten, wie es in China bei Menschen beschrieben wurde.

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Light and electron microscopical investigation of the histopathogenicity ofMacracanthorhynchus hirudinaceus in experimentally infected swine

One and 12 weeks after infection the lesions in the small intestine of two domestic pigs caused byMacracanthorhynchus hirudinaceus were studied by means of light and electron microscopy. Worms of 7 d.p.i. were found to have penetrated with their presoma into the tunica propria and partly into the tunica muscularis where they had caused local mechanic destructions and heavy eosinophilic-like and hemorrhagic reactions. Most eosinophilic-like granulocytes were attracted to the proboscis hooks, at the base of which an osmiophilic substance apparently was excreted. Worms of 84 d.p.i. had penetrated with their proboscis deeply into the tunica muscularis. The presoma had become encapsulated by a solid capsule of necrotic/inflammatory tissue in its inner part and by filamentous connective tissue in its outer part. The predominant leucocytes in the inflammatory tissue now were plasma cells indicating a progressive immune reaction. No worms were found to have perforated the entire intestinal wall as was described from human patients in China.

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Unterstützt durch ein Stipendium der VR China für Herrn Bin Zhao