Bovine neonatal pancytopenia in calves in Poland.

Bovine neonatal pancytopenia (BNP), a newly emerged syndrome of discussed etiology in calves, has been diagnosed since 2006. Here we describe first cases of BNP in Poland. Between September 2008 and April 2011, 62 cases of BNP were diagnosed in dairy calves. Bleeding skin lesions were mostly pronounced in summer and early autumn. Severe thrombocytopenia was observed in all sick animals. All calves came from herds vaccinated against BVDV infection with PregSure BVD vaccine (Pfizer). Substitution of colostrum from dams of BNP positive calves with colostrum from dams from herds free of BNP was the only effective measure to avoid new cases in affected herds.

Zinc status is associated with inflammation, oxidative stress, lipid, and glucose metabolism.

A number of studies have reported that zinc plays a substantial role in the development of metabolic syndrome, taking part in the regulation of cytokine expression, suppressing inflammation, and is also required to activate antioxidant enzymes that scavenge reactive oxygen species, reducing oxidative stress. Zinc also plays a role in the correct functioning of lipid and glucose metabolism, regulating and forming the expression of insulin. In numerous studies, zinc supplementation has been found to improve blood pressure, glucose, and LDL cholesterol serum level. Deeper knowledge of zinc's properties may help in treating metabolic syndrome, thus protecting against stroke and angina pectoris, and ultimately against death.

Testing for colon neoplasia susceptibility variants at the human COX2 locus.

BACKGROUND: Siblings and other first-degree relatives of patients with "sporadic" (i.e., apparently nonfamilial) colorectal cancer or precursor adenomatous colon polyps have an increased risk of developing colon neoplasia. This observation suggests the presence of inherited genetic determinants for sporadic colon neoplasia. Mice homozygous for a null cyclooxygenase 2 (COX2) (also called PTGS2) allele have a dramatically reduced susceptibility to the development of intestinal adenomas. In humans, use of pharmacologic inhibitors of COX2 enzyme activity are associated with reduced risk of colon neoplasia. This study examined whether the human COX2 locus may be linked to colon neoplasia in humans. METHODS: We used the affected sibling-pair method to test for linkage of the human COX2 locus to colon neoplasia. RESULTS: We examined 74 concordantly affected sibling pairs from 46 sibships with colon neoplasia. One hundred five siblings from these sibships were diagnosed with either colorectal cancer or colon adenomatous polyps before age 65 years. No linkage between COX2 and colon neoplasia was found by use of a multipoint model-free linkage analysis (estimate of allele sharing was 0.44; standard error = +/-0.04; 95% confidence interval = 0.36 to 0.52). Moreover, even allowing for heterogeneity, the potential that a COX2 colon neoplasia susceptibility variant was present within a substantial subset of these sibships was strongly excluded under either a recessive or a dominant inheritance model (95% confidence to exclude a model in which 2.7% or more of the sibling pairs harbor a dominant susceptibility allele). CONCLUSIONS: This study of concordantly affected sibling pairs thus demonstrates that variations in the COX2 gene are unlikely to be a source of individual susceptibility to colon neoplasia in humans.

Somatic mutation of hPMS2 as a possible cause of sporadic human colon cancer with microsatellite instability.

Inactivation of DNA-mismatch repair underlies the genesis of microsatellite unstable (MSI) colon cancers. hPMS2 is one of several genes encoding components of the DNA-mismatch repair complex, and germline hPMS2 mutations have been found in a few kindreds with hereditary nonpolyposis colorectal carcinoma (HNPCC), in whom hereditary MSI colon cancers develop. However, mice bearing null hPMS2 genes do not develop colon cancers and hPMS2 mutations in sporadic human colon cancers have not been described. Here we report that in Vaco481 colon cancer the hPMS2 gene is inactivated by somatic mutations of both hPMS2 alleles. The cell line derived from this tumor is functionally deficient in DNA mismatch repair. This deficiency can be biochemically complemented by addition of a purified hMLH1-hPMS2 (hMutLalpha) complex. The hPMS2 deficient Vaco481 cancer cell line demonstrates microsatellite instability, an elevated HPRT gene mutation rate, and resistance to the cytotoxicity of the alkylator MNNG. We conclude that somatic inactivation of hPMS2 can play a role in development of sporadic MSI colon cancer expressing the full range of cancer phenotypes associated with inactivation of the mismatch repair system.

Biallelic inactivation of hMLH1 by epigenetic gene silencing, a novel mechanism causing human MSI cancers.

Mutations of DNA mismatch repair genes, including the hMLH1 gene, have been linked to human colon and other cancers in which defective DNA repair is evidenced by the associated instability of DNA microsatellite sequences (MSI). Germ-line hMLH1 mutations are causally associated with inherited MSI colon cancer, and somatic mutations are causally associated with sporadic MSI colon cancer. Previously however, we demonstrated that in many sporadic MSI colon cancers hMLH1 and all other DNA mismatch repair genes are wild type. To investigate this class of tumors further, we examined a group of MSI cancer cell lines, most of which were documented as established from antecedent MSI-positive malignant tumors. In five of six such cases we found that hMLH1 protein was absent, even though hMLH1-coding sequences were wild type. In each such case, absence of hMLH1 protein was associated with the methylation of the hMLH1 gene promoter. Furthermore, in each case, treatment with the demethylating agent 5-azacytidine induced expression of the absent hMLH1 protein. Moreover, in single cell clones, hMLH1 expression could be turned on, off, and on again by 5-azacytidine exposure, washout, and reexposure. This epigenetic inactivation of hMLH1 additionally accounted for the silencing of both maternal and paternal tumor hMLH1 alleles, both of which could be reactivated by 5-azacytidine. In summary, substantial numbers of human MSI cancers appear to arise by hMLH1 silencing via an epigenetic mechanism that can inactivate both of the hMLH1 alleles. Promoter methylation is intimately associated with this epigenetic silencing mechanism.