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141.
Dairy cows often have to choose which of two sides to enter in the milking parlour. Some cows are very consistent in this choice, and it is common to assume that when these cows are more disturbed are being milked in their non-preferred side. Such disturbance might involve significantly poor welfare. In order to assess this assumption, we decided to study the behaviour and milk yield of dairy cows and their relationships with side preference in the milking parlour. The study was carried out at Cambridge University Farm, in a two-sided tandem milking parlour. The data collection followed the daily management routine. We recorded the side chosen by each cow (left or right) during 40 milking sessions. Data from 70 cows, which were present in at least 25 milking sessions (mode=36), were included in the statistical analysis. Cows' reactivity (CR) during premilking udder preparation, time spent fitting the milking cluster (FT), milk yield (MY) and duration of milking (DM) were measured. There was evident individual variation in the consistency of side choice. Individual differences (ANOVA, P<0.001) were also found in CR, FT, MY and DM; although these variables were not significantly affected by the side or the interaction animalxside (ANOVA, P>0.05). The comparison between left and right side means (paired t-test) of these variables did not show significant differences (P>0.05). We concluded that there is no evidence that the cows were discomforted or stressed when milked in the non-preferred side of the milking parlour.  相似文献   
142.

Background

Familial adenomatous polyposis (FAP) is a disease characterized by the development of hundreds to thousands of adenomatous polyps in the colorectum early in life. Virtually all patients with FAP will develop colorectal cancer before the age of 40 to 50 years, unless prophylactic colectomy is performed, which significantly improves their prognosis. The mortality pattern has changed and duodenal cancer now is one of the main cancer-related causes of death in these patients. Practically all patients with FAP develop premalignant duodenal adenomas, which may develop to duodenal cancer in approximately 3-7% of patients. Duodenal cancer in patients with FAP has a poor prognosis. The clinical challenge is to identify patients at high-risk for duodenal carcinoma. Chemoprevention would be desirable to avoid duodenectomy. The main goal of this study is to identify risk markers in normal duodenal mucosa of patients with FAP, that could help identify patients at increased risk for malignant transformation.

Methods

Messenger RNA (mRNA) levels of glutathione S-transferase A1 (GSTA1), glutathione S-transferase P1 (GSTP1), KIAA1199, E-cadherin, peroxisome proliferative activated receptor δ (PPARδ), caspase-3, cyclin D1, β-catenin, and cyclooxygenase-2 (COX-2) were measured in duodenal mucosa, using the QuantiGene 2.0 Plex assay. Levels in normal appearing mucosa of patients with FAP (n?=?37) were compared with levels in non-FAP patient controls (n?=?16). In addition, levels before and after treatment with either celecoxib & ursodeoxycholic acid (UDCA, n?=?14) or celecoxib & placebo (n?=?13) were evaluated in patients with FAP.

Results

mRNA levels of glutathione S-transferase A1 (28.16% vs. 38.24%, p?=?0.008) and caspase-3 (3.30% vs. 5.31%, p?=?0.001) were significantly lower in patients with FAP vs. non-FAP patient controls, respectively. COX-2 mRNA levels in normal duodenal mucosa of patients with FAP were found to be unexpectedly low. None of the potential risk markers was influenced by celecoxib or celecoxib & UDCA.

Conclusions

Protection against toxins and carcinogens (GSTA1) and apoptosis (caspase-3) is low in patients with FAP, which could contribute to increased susceptibility for malignant transformation of duodenal mucosa.

Trial registration

http://ClinicalTrials.gov number NCT00808743
  相似文献   
143.
Interactions involving several parasite species (multi-parasitized hosts) or several host species (multi-host parasites) are the rule in nature. Only a few studies have investigated these realistic, but complex, situations from an evolutionary perspective. Consequently, their impact on the evolution of parasite virulence and transmission remains poorly understood. The mechanisms by which multiple infections may influence virulence and transmission include the dynamics of intrahost competition, mediation by the host immune system and an increase in parasite genetic recombination. Theoretical investigations have yet to be conducted to determine which of these mechanisms are likely to be key factors in the evolution of virulence and transmission. In contrast, the relationship between multi-host parasites and parasite virulence and transmission has seen some theoretical investigation. The key factors in these models are the trade-off between virulence across different host species, variation in host species quality and patterns of transmission. The empirical studies on multi-host parasites suggest that interspecies transmission plays a central role in the evolution of virulence, but as yet no complete picture of the phenomena involved is available. Ultimately, determining how complex host–parasite interactions impact the evolution of host–parasite relationships will require the development of cross-disciplinary studies linking the ecology of quantitative networks with the evolution of virulence.  相似文献   
144.

Background  

Upon appropriate stimulation, plants increase their level of resistance against future pathogen attack. This phenomenon, known as induced resistance, presents an adaptive advantage due to its reduced fitness costs and its systemic and broad-spectrum nature. In Arabidopsis, different types of induced resistance have been defined based on the signaling pathways involved, particularly those dependent on salicylic acid (SA) and/or jasmonic acid (JA).  相似文献   
145.

Introduction  

Chondrocytes experience a hypertonic environment compared with plasma (280 mOsm) due to the high fixed negative charge density of cartilage. Standard isolation of chondrocytes removes their hypertonic matrix, exposing them to nonphysiological conditions. During in vitro expansion, chondrocytes quickly lose their specialized phenotype, making them inappropriate for cell-based regenerative strategies. We aimed to elucidate the effects of tonicity during isolation and in vitro expansion on chondrocyte phenotype.  相似文献   
146.
Comparative morphology of the sagittal otolith in Serranus spp.   总被引:2,自引:0,他引:2  
Variations in the morphology of saccular otoliths (sagittae) among three sympatric species of the genus Serranus ( S. atricauda , S. cabrilla and S. scriba ) from the Canary Islands were investigated. Although the otolith gross morphology was similar among species, S. scriba was distinct in having a rostrum which had a slight turning at the tip and a more funnel‐like ostium. The shallower water species ( S. scriba ) had otolith and sulcus areas which were smaller than the deeper water species ( S. cabrilla and S. atricauda ). The sulcus acusticus and ostium size were correlated with the habit depth of the species, with the highest values in the deepest species, S. cabrilla . The otolith outline shape indices changed with size (total length) of the species, and allowed the separation of the species by means of a discriminate function.  相似文献   
147.
148.
149.
Molecular evolution of the period gene in Drosophila athabasca   总被引:1,自引:0,他引:1  
We measured nucleotide variability within and between the three semispecies of the Drosophila athabasca complex, at the period (per) gene by using a polymerase chain reaction-based four-cutter restriction- enzyme analysis. The levels of polymorphism varied considerably between the three semispecies. Our results for per, combined with previous data for X-linked allozymes, suggest that the X chromosome in the western- northern semispecies is less variable than expected under an equilibrium-neutral model. Both the pattern of divergence between the semispecies and a cladistic clustering of per haplotypes support the previously hypothesized grouping of eastern A and eastern B as the two most recently diverged semispecies. A 21-bp in-frame segment in the region of per which shares sequence similarity with the neuronal development gene single minded is deleted in all eastern A and eastern B flies examined but is present in all of the western-northern flies and all other published per sequences. Despite these hints that there may be significant differences at the per gene between the semispecies, especially the western-northern group versus the two eastern groups, there is no compelling evidence that per is involved in the mating song differences between the semispecies.   相似文献   
150.
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