Risk factors associated with cytological endometritis diagnosed at artificial insemination in dairy cows.

In this study, we aimed to determine risk factors associated with cytological endometritis (CYTO) diagnosed at artificial insemination (AI) in dairy cows. The CYTO risk factors were evaluated based on 1.625 AI-CYTO samples obtained from 873 Holstein-Friesian cows from in total 18 dairy herds in Flanders (Belgium). The endometrial cytology samples were obtained using the cytotape technique, which consisted of adapting a 1.5 cm piece of paper tape to a standardly loaded AI catheter, covered with a double guard sheet. The polymorphonuclear cells' (PMNs) cut-off point for CYTO at AI was set at ≥ 1%. We constructed multilevel generalized mixed effect models in order to identify the risk factors associated with the presence of CYTO at AI. The CYTO prevalence at AI was 27.8% at the animal level, while the within-herd level prevalence ranged from 10.7 to 39.7%, with an average of 28.1%. Risk factors associated with the occurrence of CYTO were parity ≥2 [odds ratio (OR) = 1.8], days in milk (DIM) at AI ≥ 124 (OR = 0.4), and warm months of the year [July (OR = 2.9), August (OR = 2.3), and September (OR = 1.4)]. In conclusion, the present study supports that multiparous cows and cows that are inseminated in the summer months have a higher risk to suffer from CYTO at insemination, while the risk for CYTO is lower when the insemination is taking place at ≥ 124 DIM.

Cytological endometritis at artificial insemination in dairy cows: Prevalence and effect on pregnancy outcome.

The aims of our field study in dairy cows were (1) to consolidate cytotape (CT) as a valid technique to diagnose cytological endometritis (CYTO) during artificial insemination (AI); (2) to establish a cutoff point concerning the polymorphonuclear cells (PMN) proportion to diagnose CYTO at AI; (3) to assess the prevalence of CYTO at AI; and (4) to evaluate the effect of CYTO on the pregnancy outcome of that AI. The investigation was performed using 1,625 AI-CT samples harvested from 873 Holstein-Friesian cows from 18 dairy farms in the Flemish region of Belgium. The CT device consisted of adapting a 1.5-cm piece of paper tape on the top of a conventional AI catheter covered with a double guard sheet, allowing an endometrial cytology sample to be taken when performing an AI. A receiving operator characteristic curve was built to assess the threshold level above which the PMN proportion significantly affected the AI success. Multilevel generalized mixed-effect models were built to identify factors affecting the pregnancy outcome of the AI under investigation. Only 7 samples (0.4%) harvested in 5 cows were discarded because of low-quality parameters. The cutoff point for CYTO at AI was set at ≥1% PMN (sensitivity=33.8%, specificity=88.6%). Prevalence of CYTO at AI was 27.8%. The conception rate for CYTO-positive samples was 32.7%, whereas it was 47% for CYTO-negative samples. A CYTO-negative AI had 1.8 [odds ratio (OR)] more chances to become pregnant than a CYTO-positive one. Other factors identified as detrimental for the pregnancy outcome were body condition score ≤1.5 (OR=0.6), relative 305-d milk yield (OR=0.9), dystocia (OR=0.3), parity ≥2 (OR=0.7), and warm months of the year. In conclusion, CT is a consolidated technique to diagnose CYTO at AI, PMN 1% is the threshold level to diagnose CYTO at AI, around one-quarter of inseminated uteri suffer from CYTO, and affected uteri having a significantly lower chance to become pregnant from that insemination.

Prevalence of cytological endometritis and effect on pregnancy outcomes at the time of insemination in nulliparous dairy heifers.

The objectives of the present study were to assess the prevalence of cytological endometritis (CYTO) at the time of artificial insemination (AI) and its effect on pregnancy outcomes in nulliparous dairy heifers. In total, 512 endometrial cytology samples were taken during AI from 351 nulliparous Holstein-Friesian heifers using cytotape (a 1.5-cm piece of paper tape rolled on the top of an AI catheter covered with a double guard sheet). After sampling, the top of the AI catheter was gently rolled onto a glass slide, air-dried, and stained using Diff-Quick (Fisher Diagnostics, Newark, DE). For each slide, 300 nucleated cells were counted, and the polymorphonuclear cell ratio (% PMN) was assessed at 400× magnification. We constructed a receiver operating characteristic curve to find the cutoff point at which sensitivity and specificity (% PMN) affected pregnancy outcomes. The receiver operating characteristic curve revealed that the threshold level for diagnosing CYTO in nulliparous dairy heifers was 1% PMN. An insemination was considered successful when pregnancy was confirmed by rectal palpation at least 45d post-AI. Heifers were considered not pregnant when they received a subsequent insemination or were diagnosed empty by rectal palpation. We built multilevel generalized mixed-effect models to test factors affecting pregnancy outcomes and the occurrence of CYTO at AI. We excluded 16 samples harvested from 12 heifers due to poor sample quality or unavailability of reproductive data. Of the 496 AI samples, the prevalence of CYTO at AI was 7.86% (n=39). The conception rate was 62.8% (n=287) in CYTO-negative samples (n=457) and 38.46% (n=15) in CYTO-positive samples. Risk factors for non-pregnancy were a previous AI (odds ratio 2.96; 95% confidence interval: 1.21-7.26) and the interaction between CYTO and previous AI. The only risk factor identified as being associated with the occurrence of CYTO was a previous AI (odds ratio 4.7; 95% confidence interval: 2.15-10.34). The performance of unsuccessful inseminations significantly affects reproductive outcomes in subsequent AI and may lead to CYTO in nulliparous dairy heifers.

SCE variability in lymphocytes and fibroblasts. A controlled study.

To determine whether the sister chromatid exchange (SCE) distributions obtained in lymphocytes and fibroblasts from different individuals are comparable, a controlled study was set up. Peripheral blood and skin biopsies were taken on the same day from five individuals living for years under the same environmental conditions. All samples were treated in the same fashion, and the SCEs were scored in 50 metaphases of peripheral blood lymphocytes and of skin fibroblasts in an early and in a late passage. A repeat blood sample was taken from the same five individuals 1 year later. Based on the results obtained in this first part of the study, five randomly chosen healthy blood donors were sampled at different times and studied in the same fashion. Each chromosome was identified, and the SCE scores were tabulated per chromosome over 50 metaphases. The statistical analysis consisted of fitting log linear models to these scores and examining the best fit by determining the exceedance probabilities (observed significance level). For lymphocytes, the results indicated that the SCE distributions depended only on the chromosome examined, and not on BrdU-exposure time, individuals, or time of sampling. Treatment with ethyl methane sulfonate (EMS) increased the number of SCEs proportionally on all chromosomes. Analysis of the SCE scores on lymphocytes and fibroblasts of the five individuals and on their low and high passage fibroblast cultures revealed the necessity of including higher order interactions in order to fit a suitable model to the data. Therefore comparison of the SCE scores of lymphocytes with those of fibroblasts or comparison of scores on fibroblasts from different individuals could not be done. In practice, to compare samples or individuals, it suffices to score the SCE on a limited number of chromosomes (e.G., the A group) of 50 metaphases.

Non-uniform distribution of sister chromatid exchanges in human lymphocytes.

To test whether sister chromatid exchange (SCE) scores on human chromosomes have a uniform distribution, simulated SCE scores were generated and compared with observed scores using log-linear models. The analysis was performed at the level of the chromosome groups. Using this method we first tested whether the number of SCEs was distributed uniformly, i.e. proportional to the relative length of the chromosomes. Refinements of this hypothesis were made by considering a variable region around a first SCE to be inert for other SCEs and by making the occurrence of an SCE on a chromosome dependent on the occurrence of another SCE on the same chromosome. In further analyses it was tested whether the number of SCEs was proportional to the number of G bands on a chromosome, or to the DNA content of the chromosomes. None of the tested hypotheses fitted the observed data, establishing the non-uniform distribution of these events.

Statistical evaluation of sister chromatid exchanges.

Log-linear models are fitted to sister chromatid exchange (SCE) scores in order to test the significance of the differences in SCE scores observed between individuals or between experimental treatments. The analysis is performed at the level of chromosome groups. In each single test all measurements from all chromosome groups, both from the control and from the experimental sets, are utilized. By proceeding in this way full use is made of all the available information on the SCE scores at the level of chromosome groups and the shortcomings of the classical Student-t and chi-square tests are avoided.

Statistical evaluation of sister chromatid exchanges: refined method.

The statistical problems in evaluating the results of sister chromatid exchange (SCE) scores can be solved by fitting log-linear models to the number of SCE scores (2). In each single test all measurements from all chromosome groups, both from the control and from the experimental sets are utilized. Previously, we analyzed for each chromosome group the number of metaphases with specified total SCE score for the group. We have refined this method to an analysis of the total number of chromosomes with specified SCE score over all metaphases. The results show that the refined method uses more information and can lead to conclusions which are at variance with the conclusions of the first method. By proceeding in this way, better use is made of all available information on the SCE scores and the shortcomings of the classical Student's t-test and chi-square (X2) tests are avoided.

Pseudo obstrucción intestinal asociada a lupus eritematoso. / Lupus eritematosus with associated intestinal pseudo-obstruction.

Se presenta el caso de una paciente atendida en el Hospital Base Cayetano Heredia, que tuvo el diagnóstico de Lupus Eritematoso sistémico (LES) que en el curso de su enfermedad se complica con un pseudo-obstrucción intestinal. En relación con este caso, se revisaron todos lo pacientes del Servicio de Reumatología con diagnóstico de LES que presentaron complicación semejante, con resultados negativos; se revisa el tema sobre pseudo-obstrucción intestinal y el compromiso que el LES tiene sobre el tracto digestivo..

[Deprived socio-cultural environment and the work of fragmentation]. / Milieu socio-culturellement défavorisé et travail de fragmentation

The author tries to comprehend the child culturally handicapped, not as a problem in itself, but as an expression of the dominering-dominated relationship in a given society.