Anti-DTNA monoclonal antibody, clone 2D3

Several factors have combined with art upper respiratory tract disease (URTD) to produce declines on some population numbers of desert tortoises (Gopherus agassizii) in die western USA. This study was designed to determine the seroepidemiology of URTD in a population of wild adult tortoises at the Desert Tortoise Research Natural Area (DTNA) study site in Kern County (California, USA). Prior to initiation of the study, there was a dramatic decline in the number of individuals in this population. At each individual time point, samples were obtained from 12 to 20 tortoises with radiotransmitters during winter, spring, summer, and fall from 1992 through 1995. During the course of the study, 35 animals were sampled at one or more times. Only 10 animals were available for consistent monitoring throughout the 4 pr period. Specific antibody (Ab) levels to Mycoplasma agassizii were determined for individual tortoises by an enzyme linked immunosorbent assay (ELISA) test. Specific Ab levels were not influenced by the gender of the tortoise. Levels of Ab and distribution of ELISA+, ELISA- and suspect animals were not consistently affected by season within a single year or for a season among the study years. Significantly more tortoises presented with clinical signs in 1992 and 1995, The profile of ELISA+ animals with clinical signs shifted from 5% (1992) to 42% (1995). In 1992, 52% of tortoises lacked clinical signs and were ELISA-. In 1995, this category accounted fur only 19% of tortoises. Based on the results of this study, we conclude that URTD was present in this population as evidenced by the presence of ELISA+ individual animals, and that the infectious agent is still present as evidenced by seroconversion of previously ELISA- animals during the course of the study. There is evidence to suggest that animals may remain ELISA+ without showing overt disease, a clinical pattern consistent with the chronic nature of most mycoplasmal infections. Further, there are trends suggesting that the clinical expression of disease may be cyclical. Continued monitoring of this population could provide valuable information concerning the spread of URTD in wild tortoise populations.

Mutations in the K-ras oncogene are common in colo-rectal cancer, which affect the biological behaviour and may influence the susceptibility to therapy in these tumors. The objective of this work was to identify the types of K-ras mutations observed in referred patients with colo-rectal Cancer and to relate them to their degree of histological differentiation and clinical stage. Histopathological and clinical data were obtained from medical records. DTNA was obtained from both, fresh tissue and tumor tissue embedded in paraffin. The K-ras gene was amplified through the polymerase chain reaction (PCR) and the amplified fragments were digested with restriction enzymes. We found mutations in codons 12 and 13 of the K-ras oncogene in 23.33% of patients. Of these, 28.57% were located at codon 12, 57.14% were at codon 1.3 and 14.29% at both codons. They were more frequent in tumors located in the left hemicolon and, according to their histological type, were more frequent in well differentiated adenocarcinomas (58.70%) and in mucinous (28.57%). The identified mutations were more frequent in advanced stages (C2) of Dukes' classification. The molecular analysis of the K-ras oncogene made mutations evident, which could be Useful in the diagnosis and prognosis of colorectal tumors. The frequency of mutations found in this work is similar to some of those reported worldwide; however, they differ in the more frequent type of mutation, which, in our study, was located at codon 13 in more than 50% of the cases.