Differentiation of Coxiella burnetii by Sequence Analysis of the Gene (com1) Encoding a 27-kDa Outer Membrane Protein

The gene (com1) encoding a 27-kDa outer membrane protein in 21 strains of Coxiella burnetii from a variety of clinical and geographical sources was sequenced for strain differentiation. The com1 gene was highly conserved among all the strains tested but there were several differences in nucleotide and deduced amino acid sequences. Based on the com1 gene-specific nucleotides and deduced amino acids, the 21 strains were divided into four groups. Group 1 contained 14 strains originating from ticks, cattle and human cases of acute Q fever. Groups 2 and 3 included 2 and 3 strains, respectively, originating from human cases of chronic Q fever. Group 4 contained 2 strains originating from a human case of acute Q fever and a goat with abortion. The results indicated that the strains originating from ticks, cattle and human cases of acute Q fever differed at the molecular level from those of human chronic Q fever. This study suggests that a sequence analysis of the com1 gene can be used for strain differentiation of C. burnetii.     

Incidence of infantile hypertrophic pyloric stenosis in Saskatchewan, 1970-85.

We reviewed the incidence rates of infantile hypertrophic pyloric stenosis (IHPS) and pylorospasm in Saskatchewan from 1970 to 1985 and found a marked decrease in the rates after 1976. As expected, there was a preponderance of males among those with IHPS and among those with pylorospasm discharged from hospital between 1 and 3 months of age. No seasonal pattern was observed. We believe that the decrease in incidence rates was related to environmental influences, such as changes in the methods of feeding observed since 1977.     

High expression of Met/hepatocyte growth factor receptor suppresses tumorigenicity in NCI-H1264 lung carcinoma cells.

The protein product of c-met proto-oncogene, Met, is a tyrosine kinase receptor for the hepatocyte growth factor (HGF). Met receptor is expressed in normal human bronchial epithelium. In comparison, its expression in squamous cell carcinoma (SQCC) of the lung is markedly decreased in a great majority of cases. To understand further the role of Met receptor overexpression in non-small-cell lung carcinoma, we forced-expressed the full-length met cDNA in the NCI-H1264 (H1264) lung carcinoma cell line with low constitutive expression of this receptor. In vitro studies demonstrated that increased Met expression in H1264 cells resulted in strong inhibition of their ability to form soft agar colonies and in marked suppression of tumorigenicity in the subcutaneous tissue of immune-deficient mice. This is despite inconsistent alteration in the proliferation rate on plastic surfaces. Tumor cells explanted from occasional xenograft tumors formed by the Met-overexpressing H1264 cells also demonstrated marked down-regulation of the receptor protein levels as compared to the transplanted cells. The results suggest that constitutive overexpression of Met receptor may negatively regulate the malignancy of certain human lung cancer cells.     

Degradation of insect cuticle by Paecilomyces farinosus proteases

The entomopathogenic fungus Paecilomyces farinosus showed proteolytic activity in both solid and semi-liquid culture with gelatin as sole N and C source. Semi-liquid cultures were used to characterise proteases. Zymography of crude culture filtrates showed several bands of gelatin degradation in electrophoresis gels. Gel filtration chromatography of these filtrates revealed two peaks of proteolytic activity. Ion-exchange absorption eliminated gelatin from culture filtrates while retaining activity and was used to semipurify P. farinosus proteases. Semipurified culture filtrates had basic pH (8.5 approx.) optimum for proteolytic activity. Treatment of these filtrates with effectors revealed that P. farinosus proteases are serine proteases containing sulphydryl groups. Isoelectrofocusing combined with zymography revealed the presence of several active basic isoforms. Larvae of the lepidopteran Galleria mellonella showed cuticle damage and protein release 1h after incubation with semipurified extracts of P. farinosus. These results indicate that proteolytic enzymes could be involved in insect host penetration by P. farinosus.     

Effect of dicumarol on the growth of some soil microorganisms.

The effect of dicumarol on growth of selected soil bacteria: Azotobacter chroococcum, Arthrobacter globiformis, A. citreus and Bacillus megaterium was studied. The following minimum concentrations were inhibitory in vitro: Arthrobacter citreus--20 mug/ml., Bacillus megaterium--40 mug/ml., Azotobacter chroococcum--40 mug/ml. Arthrobacter globiformis--70 mug/ml. Cells of all microorganisms studied grown in the presence of dicumarol developed aberrant morphological forms.     

Chromosomal abnormalities in ascitic fluid from patients with alcoholic cirrhosis.

Cytology and cytogenetics were used to study ascitic fluid obtained from five patients with alcoholic cirrhosis. Cytological examination showed that all fluids contained numerous mesothelial cells and some leucocytes. Cytogenetic analysis showed abnormal karyotypes in cultured cells from all five patients and in uncultured cells from three. A consistent abnormality was the presence of spreads with over 70 chromosomes. Clones of abnormal cells, with marker chromosomes, pseudodiploidy, or aneuploidy, in an effusion are characteristic of malignancy; the abnormal karyotypes fulfilled these criteria. This finding of abnormal karyotypes indicates that transformation of the mesothelium can occur in vivo, and such a reaction may be a reflection of the mutagenic effect of alcohol.     

Cloning, expression in Pichia pastoris, and characterization of a thermostable GH5 mannan endo-1,4-β-mannosidase from Aspergillus niger BK01

Background  

Mannans are key components of lignocellulose present in the hemicellulosic fraction of plant primary cell walls. Mannan endo-1,4-β-mannosidases (1,4-β-D-mannanases) catalyze the random hydrolysis of β-1,4-mannosidic linkages in the main chain of β-mannans. Biodegradation of β-mannans by the action of thermostable mannan endo-1,4-β-mannosidase offers significant technical advantages in biotechnological industrial applications, i.e. delignification of kraft pulps or the pretreatment of lignocellulosic biomass rich in mannan for the production of second generation biofuels, as well as for applications in oil and gas well stimulation, extraction of vegetable oils and coffee beans, and the production of value-added products such as prebiotic manno-oligosaccharides (MOS).