Vertebral endplate changes are not associated with chronic low back pain among Southern European subjects: a case control study

BACKGROUND AND PURPOSE

Data on the association between vertebral endplate changes and low back pain are contradictory. This study was designed to assess whether this association exists among Southern European subjects.

MATERIALS AND METHODS

Patients in this study serving as cases were 35-50 years of age with low back pain lasting >90 days, for whom a lumbar MR imaging had been prescribed. Controls were subjects 35-50 years of age, having a cranial MR imaging for headache with normal findings, and no history of clinically relevant LBP. Two hundred forty cases and 64 controls were recruited consecutively in the radiology services across 6 cities in Spain. Imaging findings and subject characteristics were gathered through previously validated instruments. Radiologists who interpreted MRI were blinded to the subject characteristics. A multivariate logistic regression model was developed to assess the association of vertebral endplate changes with LBP, adjusting for sex, age, body mass index, lifetime exposure to smoking, physical activity, disk degeneration, and the interaction between disk degeneration and vertebral endplate changes.

RESULTS

Vertebral endplate changes were found in 80.4% of the cases and in 87.5% of the controls. In the regression model, disk degeneration was the only variable showing a confounding effect. Results showed that after adjusting for disk degeneration, the presence of vertebral endplate changes is associated with the absence of chronic LBP (OR for LBP: 0.31; 95% CI, 0.10-0.95).

CONCLUSIONS

In Southern European subjects, vertebral endplate changes are not associated with chronic LBP.

Repeated superovulation using a simplified FSH/eCG treatment for in vivo embryo production in sheep

This study investigated the efficacy of a simplified repeated superovulation treatment (eCG plus FSH in a single dose, rather than the usual protocol of six decreasing doses of FSH) in the in vivo embryo production in Ojalada donor ewes during the breeding season. In vitro viability after vitrification and warming of embryos recovered from both treatments was also assessed. In addition, the study examined the effects of the concentration of anti-eCG antibodies before each eCG/FSH treatment on in vivo embryo production. Thirty-eight females at the end of their reproductive lives were given the decreasing (n = 19) or simplified (n = 19) superovulatory treatment up to three times at intervals of ≥ 50 d. The onset of estrus was 5 h earlier (P < 0.05) among ewes that received the eCG/FSH protocol (25.2 ± 0.80 h) than it was among those that received the decreasing superovulatory treatment (30.1 ± 1.0 h), but the two treatments did not differ significantly in ovulation rates or the number and viability of embryos recovered. Both of the superovulatory protocols were significantly (P < 0.05 to P < 0.01) less effective after the first application. After three superovulatory treatments, the average number of viable embryos per ewe was 14.1 ± 2.3 and 13.7 ± 2.5 in the decreasing and simplified protocols, respectively. High anti-eCG antibody concentrations just before the superovulatory treatment with eCG/FSH were associated with a significant decrease (P < 0.05) in the rates of fertilization, viability, and freezability, especially in the second and third recoveries. Repeated superovulatory treatments with eCG/FSH can provide an efficient means of producing high quality embryos in the ewes of endangered breeds at the end of their reproductive lives, although further studies are needed to characterize the response associated with high concentrations of anti-eCG antibodies.

Growth and lay modelling in a population of Castellana Negra native Spanish hens

1. This study shows the results of (a) fitting growth data to a Gompertz-Laird model and (b) fitting egg production per housed bird to a Grossman model, in a population of Castellana Negra hens. 2. The maximum growth point for males and females, respectively, occurred at 10.6 and 9.3 weeks and the estimated weights at maturity were 2852 and 1878 g. Growth curve parameters were lower than those of commercial lines and similar to reports of other unselected breeds. 3. The start of lay was at 23 weeks. Total egg production reached 163 at 52 weeks, with a persistency (length of constant production) of 3.4 weeks and a production maximum of 69%. The maximum rate of change segment of the laying curve started at 24.3 weeks of age, and the production maximum started at 5.8 weeks into lay. The rate of decline was 1.4% weekly. 4. The Castellana Negra breed belongs to the class of slow-growing light lines and egg production was 163 eggs per calendar year.