Relationship Between Condition,Aggression, Signaling,Courtship, and Egg Laying in the Field Cricket,Gryllus assimilis

Sexual selection theory suggests males in good condition should be more successful than males in poor condition when competing with rivals for territories and mates. Understanding how condition influences the interplay between aggression, mate attraction, and courtship displays could help explain why variation is maintained in traits that confer fitness. Using laboratory‐reared Jamaican field crickets, Gryllus assimilis, we found that fine‐scale temporal components of mate attraction signals were positively correlated with body condition (residual body mass) and body size; signaling effort was positively correlated with both body condition and fine‐scale temporal signaling components; aggression was positively correlated with signaling effort; number of eggs laid was positively correlated with female body size, male body condition and aggression. Together our correlative study suggests that variation in body condition and size may drive some of the variation in cricket mate attraction signaling and aggression. Given condition and body size are influenced by foraging ability, nutrient availability and the organism’s ability to uptake and retain these essential nutrients could explain some of the persistent variation in fitness conferring traits.     

Treatment of autoimmune disease with extracorporeal photochemotherapy: progressive systemic sclerosis.

In this report, we describe the use of extracorporeal photochemotherapy in n the treatment of two patients with rapidly advancing progressive systemic sclerosis. Both patients experienced improvement in the cutaneous as well as the systemic manifestations of their disease while undergoing therapy. The potential therapeutic mechanisms are discussed.     

On the suitability of gelatin for plate cultures. II

Summary In continuation of our investigation into the factors which determine the suitability of gelatin for colony formation it was demonstrated that surface tension lowering substances added in small concentrations to plate media prepared with a poor gelatin have a decidedly favourable effect. Especially Tweens were examined. An addition of 0.01% Tween 60 or 80 to the gelatin media was sufficient to bring about growth of typical lobated colonies of bothBacterium coli andFlavobacterium aquatile. In none of the experiments made did the Tweens, in the low concentrations applied, exhibit any toxic effect. No direct method for the determination of the surface tension of gels being available, we resorted to the determination of the wettability of the various gelatin gels. With the aid of this method it was found that the contact angle of water droplets on 10% gelatin gels correlated satisfactory with colony appearance. It seems probable that gelatins of good quality contain some constituent which increases the wettability of the gel. Finally it was shown that addition of Tweens to agar gels produces analogous effects on colony growth.     

Mycobacterium tuberculosis DNA in tissue affected by sarcoidosis.

OBJECTIVE--To investigate the prevalence of Mycobacterium tuberculosis DNA in granulomatous tissues from patients with sarcoidosis and from controls matched for age, sex, and tissue by using the polymerase chain reaction. DESIGN--Single blind control trial. SUBJECTS--16 patients with sarcoidosis who had undergone diagnostic biopsy of lung, skin, or lymph node and 16 patients with squamous cell carcinoma or Hodgkin''s disease to act as controls. In addition, four lung specimens infected with M tuberculosis were included as positive controls. RESULTS--M tuberculosis DNA was present in sarcoid tissues containing granulomas from seven of the 16 patients and one of the 16 matched controls. Two of the four specimens known to be infected with M tuberculosis were positive in the controlled experiment. CONCLUSION--These figures suggest that M tuberculosis DNA is detected as readily in patients with sarcoidosis as in patients with frankly tuberculous tissues and imply that M tuberculosis may be linked to the cause of sarcoidosis.     

Febrile temperatures unmask biophysical defects in Nav1.1 epilepsy mutations supportive of seizure initiation

Generalized epilepsy with febrile seizures plus (GEFS+) is an early onset febrile epileptic syndrome with therapeutic responsive (a)febrile seizures continuing later in life. Dravet syndrome (DS) or severe myoclonic epilepsy of infancy has a complex phenotype including febrile generalized or hemiclonic convulsions before the age of 1, followed by intractable myoclonic, complex partial, or absence seizures. Both diseases can result from mutations in the Na_v1.1 sodium channel, and initially, seizures are typically triggered by fever. We previously characterized two Na_v1.1 mutants—R859H (GEFS+) and R865G (DS)—at room temperature and reported a mixture of biophysical gating defects that could not easily predict the phenotype presentation as either GEFS+ or DS. In this study, we extend the characterization of Na_v1.1 wild-type, R859H, and R865G channels to physiological (37°C) and febrile (40°C) temperatures. At physiological temperature, a variety of biophysical defects were detected in both mutants, including a hyperpolarized shift in the voltage dependence of activation and a delayed recovery from fast and slow inactivation. Interestingly, at 40°C we also detected additional gating defects for both R859H and R865G mutants. The GEFS+ mutant R859H showed a loss of function in the voltage dependence of inactivation and an increased channel use-dependency at 40°C with no reduction in peak current density. The DS mutant R865G exhibited reduced peak sodium currents, enhanced entry into slow inactivation, and increased use-dependency at 40°C. Our results suggest that fever-induced temperatures exacerbate the gating defects of R859H or R865G mutants and may predispose mutation carriers to febrile seizures.