Gene genealogies reveal global phylogeographic structure and reproductive isolation among lineages of Fusarium graminearum, the fungus causing wheat scab.

During the past decade, the plant disease called scab or Fusarium head blight of wheat and barley has reached epidemic proportions in North America and elsewhere in the world. Scab is an economically devastating plant disease, not only because it causes significant reduction in seed yields and quality, but also because infested seeds are often contaminated with trichothecene and estrogenic mycotoxins that pose a serious threat to animal health and food safety. To test whether the primary etiological agent of scab, the fungus Fusarium graminearum, is panmictic throughout its range, allelic genealogies were constructed from six single-copy nuclear genes from strains selected to represent the global genetic diversity of this pathogen. Excluding one hybrid strain, all six genealogies recovered the same seven biogeographically structured lineages, suggesting that they represent phylogenetically distinct species among which gene flow has been very limited during their evolutionary history. Parsimony analysis of the combined data set comprising 7,120 aligned nucleotide characters resolved most relationships among the seven lineages of the F. graminearum clade and related fusaria included in the study. Phylogenetic evidence is also presented for introgressive hybridization and intragenic recombination among lineages of the F. graminearum clade in nature.

Fusarium Species Pathogenic to Barley and Their Associated Mycotoxins.

Epidemics of Fusarium head blight (FHB) occurred on barley in Minnesota, North Dakota, and South Dakota from 1993 to 1998. The Red River Valley region was most severely impacted by the disease based on assessments of FHB severity in grain samples harvested from commercial fields. Fusarium graminearum was the primary pathogen causing these FHB epidemics. It comprised from 62 to 64% of all Fusarium species isolated from infected kernels from 1994 to 1996. Fusarium poae (range of isolation 13 to 20%),F. sporotrichioides (10 to 17%), and F. avenaceum (6 to 10%) also were isolated from barley kernels and were likely involved in causing some FHB infection, but to a very limited extent. All four Fusarium species were pathogenic on barley in inoculation tests conducted in both the greenhouse and the field. Mycotoxin screens were performed on barley spikes inoculated with the respective species in the greenhouse. Spikes infected with F. graminearum contained deoxynivalenol and 15-acetyldeoxyni-valenol; those infected with F. sporotrichioides contained T-2 toxin, HT-2 toxin, and T-2 tetraol; and those infected with F. poae contained nivalenol. Some isolates of F. poae also produced 15-acetoxyscirpenol and scirpentriol. Although F. graminearum and DON are recognized as the primary FHB pathogen and mycotoxin, respectively, in barley, the possible presence of other Fusarium species and mycotoxins should not be overlooked.

Determination of deoxynivalenol in wheat, barley, and malt by column cleanup and gas chromatography with electron capture detection.

A rapid and reliable method to determine deoxynivalenol (DON) in wheat, barley, and malt is described. Samples are extracted with acetonitrile-water (84 + 16). Extracts are eluted through a C18-alumina (1 + 3) column, evaporated to dryness, and derivatized with trimethylsilylimidazole-trimethylchlorosilane (100 + 1). DON is identified and quantitated by capillary gas chromatography with electron capture detection. This method can quantitate DON levels from 0.2 to 40 ppm. Multiple analyses of wheat spiked at 2 ppm and of naturally contaminated wheat, malt, and barley resulted in coefficients of variation of 5.1, 5.1, 6.0, and 9.8%, respectively. Recoveries of DON spikes at 3 levels were 94-100% for wheat, 100-105% for barley, and 100-105% for malt. Results for wheat sample analyzed with this procedure (1.9 +/- 0.1 ppm DON) compared well with results for the same sample analyzed by enzyme-linked immunosorbent assay (1.9 ppm DON) and by liquid chromatography (1.7 ppm DON).

[Pilot study of 2-pyrrolidon-acetamid (generic name: piracetam) (author's transl)]. / Klinische Prüfung von 2-Pyrrolidon-Acetamid (Generic Name: Piracetam)--Eine Pilot Study

Ten chronic schizophrenics were tested by clinical observations, psychological tests (FPI, LEV, d 2) and ratings with the Wittenborn-Psychiatric-Ratings-Scales (WPRS) before and after taking 2-pyrrolidon-acetamid. The improvement of obstructive, apathy, withdrawal and affective flatness in seven patients justify a double-blind psychometric evaluation concerning the effect of Piracetam on the schizophrenic deficiency states.

[Double-blind study of Aprotininum (Trasylol) in the management of alcoholic delirium]. / Doppelblindstudie über Aprotinium (Trasylol) in der Behandlung des Alkoholdelirs

The results of uncontrolled studies, in which the period of the delirium tremens was reduced and the intensity was lowered significantly by aprotininum, could not be verified in our double-blind study. Continuing a preliminary double-blind study another group of 20 male patients was examined again to evaluate the effectiveness of aprotininum given in a modified experimental arrangement. Not only at the beginning of the treatment but also every 6 h an infusion of 200,000 KIE Trasylol was given during the period of the acute alcohol withdrawal syndromes. Time as well as intensity of symptoms (quantitatively measured by needed chlormethiazol) did not differ significantly between the aprotininum and the placebo group.