Frequency of cattle farms with ivermectin resistant gastrointestinal nematodes in Veracruz, Mexico.

This study reports the percentage of cattle farms with ivermectin (IVM) resistant gastrointestinal nematodes (GINs) in Veracruz, Mexico, and identifies the GIN genera involved in the resistances. It also describes management practices of anthelmintic (AH) use on the surveyed farms. Twenty-one farms were assessed by means of the faecal egg count reduction test using the McMaster technique. Only two farms had GIN populations susceptible to IVM (9.5%). The proportion of farms with IVM resistant GIN was 71.4% (15/21). Seven of these farms had less than 80% egg count reductions. Haemonchus and Cooperia were the genera most commonly found in the resistant populations, followed by Oesophagostomum. Inappropriate AH treatment practices were identified from the completed questionnaires. Further management practices such as selective treatment and quarantine treatments are proposed to further reduce the spread of IVM resistance between farms.

[Immunogammagraphy with anti-CEA and anti-TAG-72 monoclonal antibodies in the diagnosis of colorectal carcinoma]. / Inmunogammagrafía con anticuerpos monoclonales anti-CEA y anti-TAG-72 en el diagnóstico del carcinoma colorrectal.

BACKGROUND: The purpose of nuclear medicine in the evaluation of colorectal carcinoma is to complete the current diagnostic protocol, by means of monoclonal antibodies (MoAb) against tumoral antigens labelled with radioactive isotopes and performing an immunoscintigraphy. PATIENTS AND METHODS: Immunoscintigraphies have been performed to 143 patients with colorectal carcinoma. Group I: antiCEA MoAb 99mTc-BW 431/26 (72 patients with 74 lesions, 48 primary tumors and 26 recurrences); group II: antiTAT-72 MoAb 111In-CYT-103 (71 patients with 75 lesions, 28 primary tumors and 47 recurrences). All positive images, not corresponding to physiological distribution of MoAb, have been considered as pathological. RESULTS: The sensitivity in the diagnosis of primary tumors in group I was worse than in group II (54.2% vs 66.7%). If rectum tumors were excluded, the sensitivity increased to 80% and 85.7%, respectively. In the suspicion of recurrences, if only lesions confirmed at surgery were considered, the sensitivity was 75% in group I and 89.7% in group II. The immunoscintigraphy has been the only technique able to diagnose recurrences in 4/23 cases from group I and 14/32 from group II. In liver, considering as metastases only hot images, the sensitivity is very low in group I (44.4%) and null in group II. No relationship has been found between tumour markers levels and the immunoscintigraphic result. CONCLUSIONS: Immunoscintigraphy is useful in patients with colorectal carcinoma, especially in the case of recurrences and it is a complementary technique to other diagnostic procedures.