Potential neurodegenerative effect of anabolic androgenic steroid abuse.

Anabolic androgenic steroids (AASs) are synthetic androgen-like compounds which are abused in sport communities despite their side effects. AAS abuse has been coupled with several medical complications, such as sterility, gynecomastia, and increased risk of cardiovascular and hepatic diseases. More recently, it has been observed that non-medical use of these steroids is frequently associated with changes in mood as well as cognitive deficits. Although the nature of this association is still largely unexplored, recent animal studies have shown the neurodegenerative potential of these compounds ranging from neurotrophin unbalance to increased neuronal susceptibility to apoptotic stimuli. Hence, exposure to AASs may result in a compromised brain, more susceptible, later in life, to the onset or progression of diseases not usually linked to drug abuse, especially neurodegenerative diseases.

Unicameral bone cyst in the scapula of an adolescent.

Unicameral bone cysts of the scapula have been reported mainly in adult patients. The atypical location of the unicameral bone cyst in a 12-year-old girl presented a diagnostic dilemma. Curettage proved to be an effective method for both diagnosis and treatment of this benign lesion.

Estradiol benzoate can function as an unconditioned stimulus in a conditioned taste aversion paradigm.

The extent to which gonadal steroid hormones can serve as unconditioned stimuli in a conditioned taste aversion paradigm was examined in Rockland-Swiss albino mice. With saccharin serving as the conditioned stimulus, subcutaneously injected estradiol benzoate, but not progesterone or testosterone propionate, was found to be a potent unconditioned stimulus in both male and female mice. Dose-response effects were also observed; increasing dosages of estradiol benzoate led to increasingly stronger conditioned aversions in both males and females. The aversion detected in males was more resistant to extinction than that seen in females. Prepubertal gonadectomy reversed the sex-dependent effects of estradiol benzoate in learned aversions in adulthood; castration of males promoted the extinction process, whereas ovariectomy of females retarded extinction. The results may be useful for our understanding of the mechanisms involved in conditioned taste aversion learning as well as a wide array of hormone-dependent behavioral responses.

Prior intrauterine position influences body weight in male and female mice.

In two longitudinal studies, intrauterine location of male and female Rockland-Swiss mice relative to fetuses of the same and opposite sex dramatically influenced body weight. In one study, body weight of males and females that were located in utero between two female fetuses (OM animals) or between two male fetuses (2M animals) was assessed from birth to the time of weaning (25 days of age). The body weights of 2M females were indistinguishable from those of OM and 2M males on all but a few of the 25 postnatal days of life. Also, 2M females were significantly heavier than OM females from Postnatal Day 6 onward, and 2M males weighed significantly more than OM males from Postnatal Day 19 onward. In a second study, food intake and body weight of animals from different intrauterine locations were examined from 25 to 120 days of age. Regardless of prior intrauterine position, males were always heavier than females. However, prior in utero location modulated body weight in that 2M females were significantly heavier than OM females and 2M males were reliably heavier than OM males. Intrauterine position effects were observed in the absence of any appreciable influence of this variable on levels of food intake. Taken together, the results suggest that prior in utero location may influence metabolic set points involved in the regulation of body weight and fat storage.

Mice: progesterone stimulates aggression in pregnancy-terminated females.

Three experiments were conducted in order to assess the role of progesterone (P) in the aggressive behavior displayed by late pregnant Rockland-Swiss mice toward adult male intruders. In Experiment 1, hysterectomy on the 15th day of gestation reduced the aggressive behavior normally displayed by pregnant mice toward male intruders. In Experiment 2, Silastic implants of P stimulated aggression in hysterectomized mice but did not fully restore the behavior to the level of fighting normally observed in pregnant animals. In Experiment 3, aggressive behavior in P-treated hysterectomized animals was inhibited by simultaneous exposure to estradiol (E). Also, treatment with E alone did not stimulate aggression in hysterectomized mice. While pregnancy-induced aggression is promoted by P, other neuroendocrine factors may act in concert with the steroid to fully stimulate aggression in gravid mice.

Intrauterine contiguity influences regulatory activity in adult female and male mice.

Female mice located in utero between two female fetuses exhibited higher levels of locomotor activity in adulthood than did females located between two male fetuses. Male mice, which were less active than females, also were influenced by intrauterine contiguity. Males located in utero between two female fetuses were more active than males which resided between two male fetuses. These results indicate that intrauterine position influences behaviors involved in the maintenance of metabolic homeostasis.

Intrauterine position modulates maternal behaviors in female mice.

Intrauterine position (IUP), the proximity of a fetus relative to same and opposite sex fetuses, is a reliable predictor of the direction and intensity of social and regulatory behaviors in adult male and female mice. In the present experiment, female Rockland-Swiss (R-S) mice who had resided in utero between two females (OM) and females who had resided between two males (2M) were compared with respect to five indices of maternal behavior: Spontaneous parental responses exhibited toward neonates; nestbuilding during pregnancy; aggression during pregnancy; aggression during lactation; and reproductive/lactation performance. There was no significant difference between 0M and 2M females in their spontaneous parental responses toward neonates or their level of nestbuilding behavior during pregnancy. However, when tested for aggression during pregnancy and lactation, 2M females exhibited aggression on a greater number of test days during pregnancy than did 0M females. Also, during pregnancy and lactation, 2M females displayed more lunges and attacks toward adult male intruders than 0M females. Although 0M females tended to have larger litters than 2M females, the animals did not differ with respect to any other measure of reproductive/lactation performance. Intrauterine position, therefore, modulates some aspects of maternal behavior but apparently not others.

Antibody responses to measles virus and canine distemper virus in multiple sclerosis.

Age-matched serum and cerebrospinal fluid from 20 multiple sclerosis patients and 20 control patients with other neurological diseases were examined for antibodies to radiolabeled measles virus and canine distemper virus using an immunoprecipitation polyacrylamide gel technique. No evidence for reactivity to unique canine distemper virus-virion polypeptides in the multiple sclerosis group was obtained. Competitive binding experiments with cerebrospinal fluid using labeled and unlabeled viral antigens failed to detect preferences in binding of antibodies for canine distemper virus versus measles virus. Cerebrospinal fluid samples tested for antiviral immunoglobulin M activity using both measles and canine distemper viruses showed no activity. The results of this study failed to implicate canine distemper virus directly as a cause of multiple sclerosis.

Postpartum behavior in the mouse: the contribution of suckling stimulation to water intake, food intake and body weight regulation.

Rockland-Swiss (R-S) Albino female mice that receive suckling stimulation from young consume significantly more water and food and gain significantly more weight than dams without young. Excision of nipples (thelectomy) prevents postpartum increases in these consummatory behaviors and in body weight gain even in dams with extensive prior suckling exposure. Thus, both the initiation and maintenance of postpartum ingestive behaviors depend primarily upon suckling stimulation from young.

Antibody responses to virion polypeptides in gnotobiotic dogs infected with canine distemper virus.

A radioimmunoprecipitation-polyacrylamide gel electrophoresis technique was applied to sera from canine distemper virus-infected dogs. Sera from fatally infected dogs precipitated only the nucleoprotein, the matrix protein, and trace amounts of fusion glycoprotein. Sera from normal convalescent dogs precipitated all five major polypeptides. In contrast, sera from persistently infected dogs were characterized by a modest overall response compared with sera from convalescent dogs and by no or little response to the matrix and phosphorylated proteins until 5 to 7 weeks after infection.

Intermale aggression and infanticide in aged C57BL/6J male mice: behavioral deficits are not related to serum testosterone (T) levels and are not recovered by supplemental T.

Healthy aged adult (24-26 months of age) and young adult (2-4 months of age) c57BL/6J male mice were assessed for intermale aggression, pup-killing behavior (infanticide), and circulating levels of testosterone (T). When compared to young adult male mice, aged adult males were highly variable in the exhibition of both androgen-dependent behaviors. Significant numbers of aged males exhibited deficits in aggression and pup-killing while other animals were as behaviorally active as their young male counterparts. Assessment of serum T showed that aging did not produce a reduction in levels of the steroid and individual variability in androgen-dependent behavior of aged males was not related to plasma levels of the hormone. When aged non-aggressive and non-killer males were exposed to supplemental T by way of subcutaneously implanted silastic capsules, circulating levels of the steroid were elevated but T-dependent behavior was not recovered. These findings, in combination with those previously reported for copulatory behavior, indicate that the deficits observed in the androgen-dependent behavior of aged male mice cannot be attributed to a breakdown in the production of testicular androgens. While neural refractoriness to T may account in part for deficits in androgen-dependent behavior of aged males, the variability that is observed in the reproductive behaviors of aged male rodents ultimately may be related to other sources of variation such as the perinatal environment.

Quantitative aspects of binding of canine serum immunoglobulins of Staphylococcus aureus protein A.

Quantitative interactions of Staphylococcus aureus protein A (SPA) and canine immunoglobulins (Ig) are described. The S aureus Cowan strain I bound canine IgG, IgM, and IgA, whereas binding was not observed with the SPA-negative Wood 46 strain of S aureus. In a quantitative adsorption experiment, the results indicated that IgA, though present in the lowest amounts in the samples, appeared to be substantially bound by SPA. Adsorption of sera with SPA-negative Wood strain bacteria resulted in nonspecific protein losses in supernatants of 0% to 15%.

Reversal of renal cortical actions of angiotensin II by verapamil and manganese.

Experiments were performed on 19 euvolemic Munich Wistar rats to examine the role of calcium in the action of angiotensin II(AII) on the glomerular microcirculation. Intravenous infusion of a mildly pressor dose of AII(N = 7 rats) led to a significant rise in mean glomerular capillary hydraulic pressure (PGC) and significant decines in glomerular plasma flow rate (QA) and the ultrafiltration coefficient (Kf). Because of these offsetting effects, single nephron GFR (SNGFR) and total kidney GFR failed to change significantly. Both afferent and efferent arteriolar resistances (RA and RE) increased during AII infusion, on average by approximately 40% and 75%, respectively. Despite continued AII infusion, addition of verapamil led to return of values for PGC, QA, Kf, RA, and RE essentially to pre-AII levels. In 7 other rats, verapamil infusion alone failed to exert significant influences on these indices. Likewise, no significant changes in these measures were observed when this same dose of AII was infused into verapamil-pretreated animals. Moreover, intrarenal arterial injection of a nonpressor dose of AII into 6 other rats also resulted in changes in PGC, QA, Kf, and RE similar to those seen during intravenous infusion, and addition of manganese abolished these effects. Since verapamil and manganese are both known to interfere with excitation-contraction coupling of smooth muscle, perhaps by inhibiting transcellular calcium transport, the present results suggest that the calcium ion may be an important cofactor required for the expression of AII action on the glomerular microcirculation, by affecting mesangial and efferent arteriolar smooth muscle contractility.