Androgen control of territorial marking in the Mongolian gerbil

Gerbils mark objects with the secretion of a midventral sebaceous gland. Both the behavior and the gland integrity are under androgen control, as indicated by castration and replacement with testosterone propionate. The integrity of the gland seems less important for marking than an influence on the central nervous system, although the gland can be used as an external measure of androgen levels. It is possible that the secretion acts as a pheromone to signal territorial possession.     

Effects of Density and Water Availability on the Behavior, Physiology, and Weight Loss of Slaughter Horses during Transport

The aim of this study was to determine the effects of density and provision of water on aggressive behavior, stress, and weight loss in slaughter horses during transport. A 16.2-m, single deck semi-trailer was divided into three compartments to create high, medium, and low density (397 ± 6.5 kg/m², 348 ± 5.2 kg/m², and 221 ± 7.6 kg/m² per compartment) groups of unrestrained horses. Six shipments containing 23 to 30 horses per shipment were transported in June and July of 2004 for 18 to 20 hours. While the truck was stopped for 1 hour after 8 hours of transport and then again just before unloading, horses in each of two compartments received water for 1 hour from six water bowls (three bowls mounted on each side of a compartment). The third, non-watered compartment served as a control. Aggressive behavior of the horses was recorded using 12 video cameras installed in the trailer. All occurrences of aggressive behavior were counted from 15-minute segments of video during 2-hour intervals for each horse that was visible in each density group. Neither density nor water significantly affected (P > 0.21) aggressive behavior, cortisol, plasma chemistry profile, dehydration, or weight loss. Aggression did not differ (P = 0.49) between the first and second halves of the shipments, indicating that fatigue had not advanced to the stage where aggression was suppressed. Individual horses, rather than density were the major cause of aggressive behavior. However, two horses went down in the high density treatment, indicating that factors in high density could lead to increased morbidity or death.     

Lymphomas in mice: failure of induction after a graft-versus-host reaction

A mild graft-versus-host reaction induced in (BALB/cJ x DBA/2J) F(1) mice by the administration of parental spleen cells that differ at several weak histocompatibility loci did not influence the development of lymphomas in these animals. Rous sarcoma virus also failed to induce tumors in the runt and control animals. Breast carcinomas, presumably due to contamination of the inoculums with mammary tumor virus, occurred in those experimental groups given parental cells, whether or not they were viable or immunologically competent. We found no evidence that the immunologic process-as represented by the graft-versus-host reaction-is causally related to the induction of neoplasia.     

Dissociation of antitumor potency from anthracycline cardiotoxicity in a doxorubicin analog

The search for new congeners of the leading anticancer drug doxorubicin has led to an analog that is approximately 1000 times more potent, noncardiotoxic at therapeutic dose levels, and non-cross-resistant with doxorubicin. The new anthracycline, 3'-deamino-3'-(3-cyano-4-morpholinyl)doxorubicin (MRA-CN), is produced by incorporation of the 3' amino group of doxorubicin in a new cyanomorpholinyl ring. The marked increase in potency was observed against human ovarian and breast carcinomas in vitro; it was not accompanied by an increase in cardiotoxicity in fetal mouse heart cultures. Doxorubicin and MRA-CN both produced typical cardiac ultrastructural and biochemical changes, but at equimolar concentrations. In addition, MRA-CN was not cross-resistant with doxorubicin in a variant of the human sarcoma cell line MES-SA selected for resistance to doxorubicin. Thus antitumor efficacy was dissociated from both cardiotoxicity and cross-resistance by this modification of anthracycline structure.     

Low-temperature synthesis of zintl compounds with a single-source molecular precursor

Thermolysis of the heterobimetallic phosphinidene complex [Sb(PCy)3]2- Li6.6HNMe2 (Cy = C6H11) at 303 to 313 kelvin gives Zintl compounds containing (Sb7)3- anions. The complex thus constitutes a stable molecular single-source precursor to Zintl compounds and provides a potential low-temperature route to photoactive alkali metal antimonates. The new chemical reaction involved, which is driven thermodynamically by the formation of P-P bonds, has implications in the low-temperature synthesis of other technologically important materials (such as gallium arsenide).