Ribosomal RNA sequence phylogeny is not congruent with ascospore morphology among species in Ceratocystis sensu stricto

The genus Ceratocystis sensu stricto includes important fungal pathogens of woody and herbaceous plants. This genus is distinguished from species in Ceratocystis sensu lato by the presence of Chalara anamorphs. Ascospore shape has been used extensively in delineating Ceratocystis taxa, which show a large variety of ascospore shapes. Sequence analysis of one region of he 18S ribosomal RNA subunit and two regions of the 28S ribosomal RNA subunit showed that there was a majority of multiple substitutions at nucleotide sites and that there was a low transition/transversion ratio, T = 0.72. Both of these results suggest that these are well established, old species. Ascospore morphology, for the most part, was not congruent with the molecular phylogeny, and the use of morphological characters may be misleading in the taxonomy of these species.      

Effect of tranylcypromine on glycogenolysis in the rat brain

In rat brain the tranylcypromine administration induces after two hours a 151% increase of serotonin levels and a 50% fall of glycogen concentration. The activity of phosphorylase a and b and the glycolytic flow rate are unchanged.     

Giemsa-based cytological assessment of area,shape and nucleus:cytoplasm ratio of goblet cells of rabbit bulbar conjunctiva

Goblet cells were visualized in impression cytology specimens from bulbar conjunctiva of the rabbit eye using Giemsa staining. Highly magnified images were used to generate outlines of the goblet cells and their characteristic eccentric nuclei. Using sets of 10 cells from 15 cytology specimens, I found that the longest dimension of the goblet cells averaged 16.7 ± 2.3 μm, the shortest dimension averaged 14.4 ± 1.8 μm and the nucleus averaged 6.3 ± 0.8 μm. The goblet cells were ellipsoid in shape and the longest:shortest cell dimension ratio averaged 1.169 ± 0.091. The goblet cell areas ranged from 108 to 338 μm² (average 193 ± 50 μm²). The area could be predicted reliably from the longest and shortest dimensions (r² = 0.903). The areas of goblet cell nuclei were 15–58 μm² (average 33 ± μm²) and the nucleus:cytoplasm area fraction was predictably greater in smaller goblet cells and less in the larger goblet cells (Spearman correlation = 0.817). The nuclei were estimated to occupy an average of 9.5% of the cell volume. The differences in size, shape and nucleus:cytoplasm ratio may reflect differences in goblet cell maturation.     

Basophils infiltrate human gastric mucosa at sites of Helicobacter pylori infection, and exhibit chemotaxis in response to H. pylori-derived peptide Hp(2-20)

Basophils, which are normally confined to the circulation, can migrate to sites of allergic inflammation. Using the specific mAb, BB1, we detected basophil infiltration of the gastric mucosa of Helicobacter pylori-infected patients affected by moderate and severe gastritis. Basophils were not found in H. pylori-free individuals or in subjects with mild gastritis. The H. pylori-derived peptide, Hp(2-20), was a potent basophil chemoattractant in vitro, whereas the control peptide, Hp1, was ineffective. Basophils from peripheral blood of healthy volunteers expressed mRNA for the formyl peptide receptors, N-formyl-peptide receptor (FPR), FPR-like (FPRL)1, and FPRL2. Preincubation of basophils with FMLP or Hp(2-20) caused complete desensitization to a subsequent challenge with homologous stimulus. Incubation of basophils with a low concentration of FMLP, which binds with high affinity to FPR, but not to FPRL1 or FPRL2, did not affect the chemotactic response to Hp(2-20). In contrast, a high concentration of FMLP, which binds to FPRL1 and FPRL2, reduced the chemotactic response to Hp(2-20). The FPR antagonist, cyclosporin H, prevented chemotaxis induced by FMLP, but not by Hp(2-20). Hp(2-20) could be responsible, at least in part, for basophil infiltration of the gastric mucosa of H. pylori-infected patients presumably through the interaction with FPRL1 and FPRL2.     

Cattle breed-variation in infestation by the horn fly Haematobia irritans

A study was carried out to assess the resistance of pure and cross-bred groups of cattle to the horn fly Haematobia irritans (Linnaeus) (Diptera: Muscidae) in northern Argentina. Pure-bred cattle were Criolla, Iberian Bos taurus Linnaeus (Artiodactyla: Bovidae) and Nellore, Bos indicus Linnaeus (Artiodactyla: Bovidae). Cross-bred cattle were Hereford, British B. taurus (34%) X Nellore (66%) and Hereford (66%) X Nellore (34%). All were heifers and animals were maintained in two groups, each containing a mixture of pure and cross-breeds. The lowest fly numbers were found on Criolla heifers and the highest on Hereford X Nellore cross-breeds. However, it could not be determined from this study whether this was a consequence of breed and/or size, as Criolla heifers were lighter than the corresponding Hereford X Nellore heifers. Fly numbers on the heifers followed an approximately negative binomial distribution. However, the ranking of individual animals in their level of infestation within subgroups was not consistent. Hence, culling the most infested heifers on any given date would at best give only a small improvement in H. irritans control.     

Antifungal activity of <Emphasis Type="Italic">Bacillus subtilis</Emphasis> 355 against wood-surface contaminant fungi

A strain of Bacillus subtilis was examined for antifungal activity against phytopathogenic and wood-surface contaminant fungi. The bacterium was grown in five culture media with different incubation times in order to study cell development, sporulation, and the production of metabolites with antifungal activity. The anti-sapstain and anti-mould activity of the bacterium grown in yeast extract glucose broth (YGB) medium in wood was also evaluated. In YGB, the bacterium inhibited the growth of several fungi and displayed a broader spectrum of activity than in the other media tested. A relationship between bacterial spore production and the formation of metabolites with antifungal activity was detected. YGB medium displayed effective control in wood block tests. YGB medium was extracted with solvents of increasing polarity and the dry residues were applied to silicagel plates, resolved with the appropriate solvent and sprayed with different solutions, detecting the presence, of amines, and higher alcohols. The bioautographic method revealed the presence of at least two active compounds against the blue-stain fungus Cladosporium cucumerinum.     

Changes in glial fibrillary acidic protein and karyotype during culturing of two cell lines established from human glioblastoma multiforme

Summary Two human cell lines (GL15 and GL22) derived from glioblastoma multiforme were established and characterized by immunohistochemical and cytogenetic techniques. The expression of glial fibrillary acidic proteins and the karyotype were analyzed at different passages for both cell lines. The course of marker-pattern differed in the two cell lines. The main findings were a cell-density-dependent expression of glial fibrillary acidic protein in the cell line GL15 at all passages and a decreased expression of this protein over time in the cell line GL22. Both cell lines had hyperdiploid karyotypes and exhibited glioma-specific chromosomal abnormalities (gain of chromosome 7 and loss of chromosome 10). In the GL15 cell line no relevant chromosomal changes were produced during culturing, whereas in the GL22 cell line a hypodiploid clone appeared at the 42nd passage. The immunohistochemical and cytogenetic data resulting from this study confirm that the two cell lines established in our laboratory originated from astrocytic tumor cells.Abbreviations MHG malignant human gliomas - GFAP glial fibrillary acidic protein - DMEM Dulbecco's modified Eagle's medium - FCS fetal calf serum - GTG banding trypsin-Giemsa banding - TBS TRIS-buffered saline 10 mM pH 7.6 - p short arm of chromosome; q long arm of chromosome - der derivative chromosome