The effect of anthelmintic resistance on the productivity in feedlot cattle.

The aim of this study was to evaluate, in a commercial feedlot, the effect of different anthelmintic drugs on the productivity of naturally infected calves from a cow-calf operation, where resistance to ivermectin (IVM) has been previously detected. The study began with the random selection of 80 calves whose weight was 132 ± 12 kg. Four groups were made: IVM, ricobendazole (RBZ), ricobendazole plus levamisol (RBZ + LEV) and a control group (CG) without treatment. On days 0, 21, 42, 70, 98 and 126, manual collection of fecal matter and individual weight were registered. Mixed SAS procedure was used for statistical analysis. The percentages of fecal egg count reduction test (FECRT) calculated 21 days post treatment (PT) were 18%, 96% and 100% for the IVM, RBZ and RBZ + LEV groups, respectively. Body weight (± SEM) at the end of the trial was 266 kg (± 0.9), 269 kg (± 1.1), 276 kg (± 1.3), 280 kg (± 1.9) for CG, IVM, RBZ and RBZ + LEV groups, respectively. The effect on live weight was highly significant (p < 0001). After 126 days of fattening, the deleterious effect of the combination of Cooperia and Haemonchus in the IVM group on body weight was evident. Undetected animals carrying anthelmintic resistant (AR) worms entering the feedlot, could cause major productivity losses.

Phenotypic differences on the outcome of the host-parasite relationship: behavior of mice of the CBi stock in natural and experimental infections.

Investigation of defined animal models may help to elucidate the role of the host genetic background in the development and establishment of a parasitic infection. Four lines of mice obtained by disruptive selection for body conformation (CBi+, CBi-, CBi/C and CBi/L) and the unselected control line CBi were examined in their response to different parasites to assess whether these distinct genotypes showed differences in their resistance to natural and experimental parasitosis. Protozoans (Trichomonas muris and Spironucleus muris) and nemathelminths (Syphacia obvelata and Aspiculurus tetraptera) were found naturally parasitizing the mice's intestines. CBi/C and CBi were the only genotypes in which T. muris was found. CBi- was least resistant to S. muris. The helminth parasitic burden showed differences between sexes within genotypes (males had a higher burden than females) and among genotypes (CBi/L males had the lowest burden). CBi/L animals were also most resistant to experimental challenge with Heligmosomoides polygyrus and Trypanosoma cruzi. Since all the animals examined shared a common habitat throughout the study and were equally exposed to infection, the phenotypic differences in the natural enteroparasitism herein described evince genetic differences among lines in the host-parasite relationship. This interpretation is further supported by the differences in the response to the experimental challenge to H. polygyrus and T. cruzi.

Changes in gastro-intestinal helminth species diversity in lambs under mixed grazing on irrigated pastures in the tropics (French West Indies).

The development of gastro-intestinal helminth diversity was monitored in lambs grazing alone or grazing with heifers in the ratio one heifer to four lambs. Five successive cohorts of lambs were studied from January 1994 to May 1996. Each cohort of lambs grazed irrigated pastures of Pangola grass for 4 months (from weaning to 6 months of age). A total of 50 lambs was necropsied and their worms counted and identified at the end of each grazing period. Four heifers were also necropsied on one occasion. Special attention was dedicated to the identification of the most pathogenic worm, i.e. Haemonchus spp. Malate dehydrogenase polymorphism in H. contortus was studied in order to evaluate changes between cohorts and between grazing managements. The species diversity was estimated by Shannon diversity indices (main species or all species). It was higher in the mixed grazing group than in the lambs that grazed alone. Diversity increased in successive cohorts. This was due in part to the acquisition of Cooperia spp. of cattle origin. The increase in diversity in the mixed grazing lambs corresponded to the lower faecal egg excretion and better weight gains recorded previously in that group. There seemed to be no cross-transmission of H. similis found in heifers and H. contortus harboured by lambs. The latter species was not morphologically or genetically different in the lambs grazed alone or with heifers, indicating that the presence of cattle did not modify qualitatively the transmission of H. contortus.

Description of Haemonchus placei (Place, 1893) (Nematoda, Trichostrongylidae, Haemonchinae), identification and intra-specific morphologic variability.

Haemonchus placei in cattle has never been completely described, possibly due to great morphological similarity with small ruminants Haemonchus contortus. It is newly described on one isolate from Argentina. It has clear distinct morphological features from sheep and goats Haemonchus contortus and presents only two female morphotypes (linguiform and knobbed) instead of three recorded in H. contortus. A key is proposed to identify females. Female as well as male Haemonchus placei from New World (Argentina, Mexico, USA) are morphologically different from those of Old World (Africa: Burkina-Faso, Mauritania and Ivory Coast) or Australia, possibly due to local evolution since their introduction several centuries ago from Africa or India. We propose to differentiate three sub-species, H. placei placei in Australia, H. placei africanus in western Africa and H. placei argentinensis in the New World.

[Study of human papillomavirus via chemiluminescence technic and polymerase chain reaction in transitional cell carcinoma of the bladder]. / Ricerca del papillomavirus umano mediante tecniche di chemiluminescenza e di polymerase chain reaction nel carcinoma a cellule transizionali della vescica.

INTRODUCTION: The exact ethiology of bladder carcinoma isn't yet known; an implication of human papillomavirus (HPV) has been recently hypothesized. MATERIALS AND METHODS: In this study HPV-DNA was investigated in urethral secretion and in bladder carcinoma of 37 patients. The analysis was performed by in vitro hybridization (chemiluminescent assay) and Polymerase Chain Reaction in order to detect HPV 6, 11, 16, 18, 31, 33 through specific primers. RESULTS: On 3 out of 37 patients (8.1%) we found the presence of HPV-DNA, only in bladder T.U.R. and not in the corresponding urethral swab. CONCLUSIONS: Our data suggest that human papillomavirus is unlikely to be involved in the pathogenesis of transitional cell carcinoma, in agreement with most European and American research groups.

Fine needle aspiration biopsy of hepatocellular carcinoma resembling neuroendocrine tumor. A case report.

BACKGROUND: The incidence of hepatocellular carcinoma (HCC) is steadily increasing in western countries. Its present incidence in Italy is about 6.9/100,000. The diagnosis is usually made by a combination of ultrasound (US), computed tomography (CT) and fine needle aspiration biopsy (FNAB). HCC resembling a neuroendocrine tumor has been described, but no previous FNAB diagnosis was reported. CASE: An asymptomatic 45-year-old man underwent a CT scan after incidental US detection of multiple focal lesions in both lobes of the liver. FNAB showed clusters of small neoplastic cells with hyperchromatic nuclei and scanty cytoplasm. A thin tissue core showed a microacinar pattern very similar to that of a neuroendocrine tumor. A large panel of specific antibodies displayed an immunophenotype consistent with HCC. CONCLUSION: In this rare variant of HCC, the final diagnosis could be assessed only by correlating the cytologic, microhistologic and immunohistochemical features.

[Women and migration plans]. / Les femmes face au projet migratoire.

PIP: "International migrations can be analysed from the family microeconomic point of view. Decisions connected with migration are in fact included in a well planned family ¿project' and the entire family is involved in defining such a project. Migrant women in particular represent, both in the country of origin and in the receiving country, a bridging factor between two societies, two countries, two cultures, not only on a personal or family level, but also through the numerous associations which have known, in the past few years, an unprecedented growth. On a macroeconomic level, integration policies are the right answer to the ¿migration project', both in their social, legal and cultural outlines." (EXCERPT)^ieng

[Prognostic value of cellular ploidy in adenocarcinoma of the middle rectum]. / Valore prognostico della ploidia cellulare nell'adenocarcinoma del retto medio.

A retrospective study of DNA content in 38 medium-rectal adenocarcinomas (a rectal part between 8 and 12 cm. from anus) was performed using flow cytometry in order to find probable correlations among ploidy, grading, staging and survival in patients who had undergone a surgical operation from January 1975 to December 1989. At the beginning of the work, 21 patients were alive and 17 were dead. Histologically 15 carcinomas (39.4%) were G1, 22 (57.8%) were G2 and only 1 (2.6%) was G3. Moreover 1 case (2.6%) was pT1, 7 (18.4%) were pT2 and 30 (78.9%) were pT3. 11 adenocarcinomas (29%) were euploid and 27 (71%) were aneuploid. These percentages agree with literature data. 11 of dead patients (64.7%) had aneuploid neoplasias and 6 (35.3%) diploid; 16 of alive patients (72.2%) had aneuploid carcinomas and 5 (23.8%) diploid. The difference of survival between aneuploid and diploid carcinomas isn't statistically significative (X2 = 0.168 ns). No correlation was found among aneuploidy, grading and staging, probably on account of small number of analyzed cases, owing to particular and little rectal part included in the study. Likely, having a larger case number we'll be able to obtain more incisive informations from this type of analysis in the next future.