Association of Streptococcus bovis Bacteremia with Bowel Disease

We reviewed the medical records of 19 patients who had Streptococcus bovis bacteremia. Eight patients had diverticulosis, four had benign adenomatous colonic polyps, and three had adenocarcinomas of the gastrointestinal tract. Laboratory workers and clinicians should be aware of the association of S. bovis bacteremia and gastrointestinal disease.     

Sclerochoroidal calcification associated with Gitelman syndrome and calcium pyrophosphate dihydrate deposition

Sclerochoroidal calcification is an uncommon condition. Metabolic evaluation and clinical examination are important to exclude associated systemic conditions such as the Bartter and Gitelman syndromes. It has been suggested that the lesions seen in sclerochoroidal calcification are calcium pyrophosphate dihydrate crystals. This report describes the first documented case in the UK of sclerochoroidal calcification associated with Gitelman syndrome and calcium pyrophosphate dihydrate deposition.     

Porphyromonas gingivalis RgpA and Kgp proteinases and adhesins are C terminally processed by the carboxypeptidase CPG70

Porphyromonas gingivalis is a bacterial pathogen that produces the polyproteins RgpA and Kgp, which are proteolytically processed into proteinases and adhesins. We have demonstrated that the RgpA and Kgp proteinases and adhesins are C terminally processed by carboxypeptidase CPG70 by sequencing C-terminal peptides from both the wild type and an isogenic CPG70 mutant, using ion trap mass spectrometry.     

Primate gastric circulation: effects of catecholamines and adrenergic blockade.

The effects of intra-arterial injections and infusions of epinephrine, norepinephrine, and isoproterenol on gastric blood flow were studied in anesthetized baboons. Blood flow was measured electromagnetically before and after adrenergic blockade. The results for injected epinephrine and norepinephrine indicate these agents to be pure vasoconstrictors in the primate gastric circulation, and this response is attenuated by alpha-adrenergic blockade with phenoxybenzamine. Isoproterenol is a pure vasodilator, and its response is attenuated following beta-adrenergic blockade with propranolol. Intra-arterial infusions of epinephrine and norepinephrine (.05 mug kg-1 min-1) resulted in sustained vasoconstriction with no evidence of autoregulatory escape and no postinfusion "over-shoot." This study suggests that epinephrine and norepinephrine might provide alternatives to vasopressin as a vasoconstrictor for the control of upper gastrointestinal bleeding.     

Mucin is produced by clara cells in the proximal airways of antigen-challenged mice

Airway mucus hypersecretion is a prominent feature of many obstructive lung diseases. We thus determined the ontogeny and exocytic phenotype of mouse airway mucous cells. In naive mice, ciliated (approximately 40%) and nonciliated (approximately 60%) epithelial cells line the airways, and > 95% of the nonciliated cells are Clara cells that contain Clara cell secretory protein (CCSP). Mucous cells comprise < 5% of the nonciliated cells. After sensitization and a single aerosol antigen challenge, alcian blue-periodic acid Schiff's positive mucous cell numbers increase dramatically, appearing 6 h after challenge (21% of nonciliated/nonbasal cells), peaking from Days 1-7 (99%), and persisting at Day 28 (65%). Throughout the induction and resolution of mucous metaplasia, ciliated and Clara cell numbers identified immunohistochemically change only slightly. Intracellular mucin content peaks at Day 7, and mucin expression is limited specifically to a Clara cell subset in airway generations 2-4 that continue to express CCSP. Functionally, Clara cells are secretory cells that express the regulated exocytic marker Rab3D and, in antigen-challenged mice, rapidly secrete mucin in response to inhaled ATP in a dose-dependent manner. Thus, Clara cells show great plasticity in structure and secretory products, yet have molecular and functional continuity in their identity as specialized apical secretory cells.     

Production and characterization of monoclonal antibodies to ARVCF

We have generated the first monoclonal antibodies (MAbs) to Armadillo repeat gene deleted in velo-cardiofacial syndrome (ARVCF), a recently identified Armadillo repeat-containing protein closely related to the catenin p120ctn. Six ARVCF-specific MAbs were characterized for isotype, species cross-reactivity, and utility in assays including immunofluorescence, immunoprecipitation, and Western blotting. All six antibodies were isotyped as IgG1 and several cross-reacted with ARVCF from a variety of species including human, rat, dog, and monkey, but not mouse. Importantly, none of the ARVCF MAbs cross-reacted with p120ctn, despite the high homology between these proteins. MAbs 3B2 and 4B1 were consistently the best in all applications and will provide valuable tools for further study of the role of ARVCF in cells.     

The effects of storage of blood and isolated DNA on the integrity of DNA

Long-term storage of DNA is required for a number of genetic studies; prior to extraction, blood samples may be subject to elevated temperatures for variable intervals. We have studied the effect of temperatures ranging from ?70°C to +65°C on human blood and on DNA extracted from it. DNA in solution stored at ambient temperatures up to 37°C for 6 months was digestible by three different restriction endonucleases, whereas storage at 45°C is deleterious after 6-7 weeks. DNA can be extracted from blood samples stored at ?70°C for at least 2 months or at 23°C for a week or more, but blood stored at these temperatures may yield less high-molecular-weight DNA. Cell pellets from which plasma has been removed also can serve as a source of DNA. Isolated DNA stored dry for years (up to 30) is difficult to dissolve and may appear degraded, but a sample stored dry for 13 years and then in solution at ?20°C for 7 years appeared to be intact.     

A mouse model of galactose-induced cataracts

Galactokinase (GK; EC 2.7.1.6) is the first enzyme in the metabolism of galactose. In humans, GK deficiency results in congenital cataracts due to an accumulation of galactitol within the lens. In an attempt to make a galactosemic animal model, we cloned the mouse GK gene (Glk1) and disrupted it by gene targeting. As expected, galactose was very poorly metabolized in GK-deficient mice. In addition, both galactose and galactitol accumulated in tissues of GK-deficient mice. Surprisingly, the GK-deficient animals did not form cataracts even when fed a high galactose diet. However, the introduction of a human aldose reductase transgene into a GK-deficient background resulted in cataract formation within the first postnatal day. This mouse represents the first mouse model for congenital galactosemic cataract.