Effect of age and menopausal status on cardiorespiratory fitness in masters women runners

Forty-nine trained masters women endurance runners (mean = 42 km.wk-1) between the ages of 35 and 70 yr (mean = 46.4 +/- 8.3) were tested on a treadmill to examine cardiorespiratory fitness (VO2max and VO2 submax) in relation to age, training, and menopausal status. Although VO2max was lower with increasing age, no age group differences occurred in VO2 submax at 5.4 km.h-1, 8% treadmill grade. The younger runners (35-39 and 40-44 yr) had significantly higher VO2max than the other 5-yr competitive age groups (45-49, 50-55, 55-70 yr) (P < 0.01). HR max did not differ across age, but HR submax was higher with increasing age. Premenopausal, transitional, and post-menopausal women were not significantly different on any exercise variable when age and/or training differences among the groups were statistically controlled. A decrease in VO2max of 0.58 ml.kg-1 x min-1 x yr-1 was determined (r = -0.62). It was concluded that 1) these highly trained women runners had higher cardiorespiratory fitness than previously reported for women of comparable age, 2) menopausal status did not effect cardiorespiratory fitness when age and training were accounted for, and 3) regular physical training seems to prevent age-related changes in HR max in women, but not age-related changes in maximal oxygen uptake.     

Fertility in estrus-cycling and noncycling virgin heifers and suckled beef cows after induced ovulation

A procedure was developed to either induce or synchronize ovulation in heifers and suckled cows. Beef females were assigned to two breeding programs: 1) two injections of prostaglandin F2alpha (PGF2alpha) given 14 d apart to synchronize estrus (PGF2alpha control; n = 179), with inseminations 12 to 16 h after detected estrus or at 80 h in the absence of estrus, or 2) two injections of PGF2alpha (d -14 and 0) plus 100 microg of GnRH on d -7 when 6 mg of norgestomet was implanted (PGF2alpha/NORG/GnRH treatment; n = 173). Implants were removed 24 h after the second PGF2alpha injection (d +1) and females were inseminated 12 to 16 h after detected estrus until 54 h after PGF2alpha. The remaining cattle were given a second 100-microg GnRH injection 54 h after PGF2alpha and inseminated 18 to 20 h later. Percentages of noncycling females with subsequently elevated progesterone (P4) on d 0 or +1 were not different between treatment groups (20.4 vs 25%), but conception rate was greater (P < .05) in noncycling treated females than in noncycling controls (55 vs 12.8%). Conception rates in cycling (59.2%) and noncycling (62.2%) treated females were similar to those in cycling controls (56.2%) but greater (P = .06) than those in noncycling controls (26.5%). Conception rates in treated females inseminated 12 to 16 h after detected estrus (63.1%) or at one fixed time (58.3%) were similar to those in controls inseminated 12 to 16 h after detected estrus (68.7%). This treatment procedure produced fertility after one timed insemination that was equal to controls inseminated after detected estrus and induced equally fertile ovulations in noncycling heifers and cows.     

Quinolinic acid and lymphocyte subsets in the intrathecal compartment as biomarkers of SIV infection and simian AIDS

Cerebrospinal fluid (CSF) samples were collected from monkeys infected with SIVmac251 (SIV) or HIV-1/SIVmac chimeric viruses (SHIV(HXBc2) and SHIV(89.6P)) to investigate quinolinic acid (QUIN) levels in the intrathecal compartment. CSF levels of QUIN were elevated in the SIV-infected monkeys, especially in animals with end-stage disease, and in those infected with pathogenic SHIV(89.6P), but not after infection with the nonpathogenic construct SHIV(HXBc2). QUIN elevations occurred in association with reduced CD4+ and increased CD8+ lymphocytes, cellular alterations that were more pronounced in CSF than in the blood. These findings support the view that the intrathecal compartment provides a unique window on viral infection, and are in keeping with the a priori prediction that QUIN increases primarily in response to more pathogenic viral strains.     

Strategies for replacing animals in biomedical research

In 1959, Russell and Burch published their recommendations for applying the Three Rs (reduction, refinement and replacement alternatives) to the use of animals in scientific experimentation. At this time, they could not have predicted the effect of this fundamental concept on academic and industrial animal experimentation and in biomedical education. Although more than 30 years have passed, their ideas are gaining respectability and wide acceptance. This article reviews the recent advances in the use of non-animal methods in biomedical research, and discusses the outlook for the further implementation of 'alternatives'.     

Are we dental assistants marketing and promoting our practices?

Two nondepolarizing myorelaxants: tracrium, with medium-long duration of action, and a new short-acting drug mivacron were used in combined anesthesia of 50 patients with gastrointestinal diseases subjected to laparoscopic cholecystectomy. Both drugs can be used for anesthesia of laparoscopic operations; mivacron should be preferred due to its shorter action.     

Vascular expression of E-selectin is increased in estrogen-receptor-negative breast cancer: a role for tumor-cell-secreted interleukin-1 alpha

Angiogenesis plays an important role in breast cancer growth and metastasis. Multiple adhesion molecules have been shown to perform critical functions in the process of angiogenesis. In this study, we analyzed 15 benign and 22 malignant estrogen-receptor-negative and estrogen-receptor-positive breast specimens for the presence of the endothelial cell adhesion molecules E-selectin and P-selectin. We found that E-selectin's expression was increased in the malignant breast tumors compared with their benign counterparts (23.86% of blood vessels versus 2.47%; P = 0.0005). Furthermore, E-selectin staining was found to be significantly increased in the estrogen-receptor-negative carcinomas compared with the estrogen-receptor-positive ones (P = 0.005). In vitro findings strongly correlated with the in vivo findings and showed a higher degree of E-selectin induction in endothelial cells exposed to conditioned media from estrogen-receptor-negative breast cancer cell lines than from estrogen-receptor-positive ones. The degree of E-selectin induction correlated with the amount of interleukin-1 alpha in the tumor-conditioned media. Neutralizing antibodies to interleukin-1 alpha significantly inhibited the E-selectin expression in endothelial cells exposed to tumor-conditioned media. The results indicate that the endothelial E-selectin expression during angiogenesis is related to breast carcinoma progression in vivo and that this component of angiogenesis may be due directly to tumor-cell-secreted interleukin-1 alpha.