The effect of extended post-mortem ageing on the Warner–Brazler shear force of longissimus thoracis from beef heifers from two sire breeds, slaughtered at 20 or 25 mo of age

peer-reviewedwere examined. Spring-born Angus × Holstein-Friesian heifers (n = 48) and Belgian Blue × Holstein-Friesian heifers (n = 48) were slaughtered, within sire breed, at 20 or 25 mo of age. Approximately 48 h post-mortem, LT steaks (2.5 cm) were removed, and either stored at −20°C for chemical analysis or vacuum-packed, stored at 2°C for 7, 14 or 28 d post-mortem and then at −20°C pending Warner–Bratzler shear force (WBSF) analysis. Muscle from Angus-sired heifers had higher (P < 0.001) intramuscular fat (IMF) concentration, lower (P < 0.001) proportion of type IIX muscle fibres and higher (P < 0.001) proportion of type IIA and type I muscle fibres compared to muscle from Belgian Blue-sired heifers. Collagen characteristics did not differ between sire breeds. Later slaughter increased (P < 0.001) IMF concentration and decreased (P < 0.001) total and insoluble concentrations and collagen solubility. There were no interactions between the main effects for WBSF and no difference between sire breeds. Later slaughter and increasing the duration of ageing decreased (P < 0.05) WBSF. Based on threshold WBSF values in the literature, all samples would be considered tender (<39 N) after 7 d ageing. Untrained consumers are likely to detect the decrease in WBSF from 7 to 14 d ageing but not due to further ageing. Within the production system examined and based on WBSF data, extending LT ageing to 28 d is not necessary to ensure consumer satisfaction

Topological analysis of striatal lesions induced by 3-nitropropionic acid in the Lewis rat.

3-Nitropropionic acid (3NP) is a succinate dehydrogenase inhibitor classically used to create animal models of Huntington's disease (HD). However, the effects of this neurotoxin are highly variable in the Sprague-Dawley rat strain, impeding the interest of such model in neuroprotection assays. In the present study, we found that continuous s.c. infusion of 3NP in the Lewis rat strain produces homogeneous clinical impairments as well as highly reproducible striatal lesions according to their location and size. More especially, using quantitative reconstructions, we have determined, after 5 days of treatment, that the lesion was topologically reproducible in the lateral part of the striatum in all tested rats. Thus, 3NP-treated Lewis rat provides an improved animal model for testing neuroprotective strategies in HD.Journal ArticleResearch Support, Non-U.S. Gov'tinfo:eu-repo/semantics/publishe

IMMUNOHISTOCHEMICAL ANALYSIS OF E-CADHERIN EXPRESSION IN HUMAN COLORECTAL TUMORS.

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Lesson of the month: Natural history and clearance of HPV after treatment of precancerous cervical lesions

Aims: To assess the clearance rate of human papillomavirus (HPV) after out-patient treatment of cervical intraepithelial neoplasia (CIN). Methods and results: A total of 122 Nicaraguan women with HPV DNA-positive and histologically confirmed CIN lesions were included in the study. Fifty-five patients with CIN1 and 67 with CIN2-3 were treated by cryotherapy and loop electrosurgical excision procedure (LEEP), respectively. Follow-up visits were scheduled at 6 weeks, 6 months, 1 year and 2 years. Investigations included cytology, HPV DNA testing and colposcopy/biopsy if needed. The clearance rate of HPV was calculated by multivariate logistic regression. Immediately after treatment, a pronounced decrease in presence of HPV was observed in both groups, with a significantly higher clearance in the LEEP group than in the cryotherapy group (P = 0.019). Subsequently, clearance continued over time and was similar between the cryotherapy group and the LEEP group (P = 0.73). Approximately the same detection rates were obtained for persistence of all HPV types and for high-risk types separately: 43.9, 37.6, 29.9 and 17.7% in the cryotherapy group and 24.9, 20.3, 15.3 and 8.4% in the LEEP group at 6 weeks, 6 months, 1 year and 2 years, respectively. Conclusions: Out-patient treatment of precancerous lesions of the cervix usually results in clearance of HPV. Both LEEP and cryotherapy are highly effective methods of eradicating HPV. HPV DNA testing may have added value in the follow-up of patients

Characterization of M cell formation and associated mononuclear cells during indomethacin-induced intestinal inflammation

M cells represent an important gateway for the intestinal immune system by delivering luminal antigens through the follicle-associated epithelium to the underlying immune cells. The goal of this study was to characterize this route of antigen uptake during intestinal inflammation by characterizing M cell formation and M cell-associated lymphocytes after indomethacin challenge in rats. We demonstrated increased M cell formation as early as 12 h after a single injection of indomethacin. The elevated M cell counts were determined until day 3 and returned to basal levels after 7 days. Electron microscopic studies revealed an expansion of mononuclear cells inside the M cell pocket that were characterized predominantly as B cells, T cell receptor (TCR)αβ- and CD4-positve T cells, whereas other markers such as CD11b, CD8 and CD25 remained unchanged. In situ hybridization studies showed increased expression of interleukin (IL)-4 by lymphocytes during intestinal inflammation in the Peyer's patch follicle. These studies illuminate the relevance of M cells during intestinal inflammation and suggest that M cells derive from epithelial cells in a certain microenvironment

Spatial differences in East Scotia Ridge hydrothermal vent food webs: influences of chemistry, microbiology and predation on trophodynamics

The hydrothermal vents on the East Scotia Ridge are the first to be explored in the Antarctic and are dominated by large peltospiroid gastropods, stalked barnacles (Vulcanolepas sp.) and anomuran crabs (Kiwa sp.) but their food webs are unknown. Vent fluid and macroconsumer samples were collected at three vent sites (E2, E9N and E9S) at distances of tens of metres to hundreds of kilometres apart with contrasting vent fluid chemistries to describe trophic interactions and identify potential carbon fixation pathways using stable isotopes. δ13C of dissolved inorganic carbon from vent fluids ranged from −4.6‰ to 0.8‰ at E2 and from −4.4‰ to 1.5‰ at E9. The lowest macroconsumer δ13C was observed in peltospiroid gastropods (−30.0‰ to −31.1‰) and indicated carbon fixation via the Calvin-Benson-Bassham (CBB) cycle by endosymbiotic gamma-Proteobacteria. Highest δ13C occurred in Kiwa sp. (−19.0‰ to −10.5‰), similar to that of the epibionts sampled from their ventral setae. Kiwa sp. δ13C differed among sites, which were attributed to spatial differences in the epibiont community and the relative contribution of carbon fixed via the reductive tricarboxylic acid (rTCA) and CBB cycles assimilated by Kiwa sp. Site differences in carbon fixation pathways were traced into higher trophic levels e.g. a stichasterid asteroid that predates on Kiwa sp. Sponges and anemones at the periphery of E2 assimilated a proportion of epipelagic photosynthetic primary production but this was not observed at E9N. Differences in the δ13C and δ34S values of vent macroconsumers between E2 and E9 sites suggest the relative contributions of photosynthetic and chemoautotrophic carbon fixation (rTCA v CBB) entering the hydrothermal vent food webs vary between the sites