THE EFFECTS OF CALCIUM ON SEROTONIN-STIMULATED ADENYLATE CYCLASE IN FRESHWATER MUSSELS

Volume: 166Start Page: 594End Page: 60

Pre-transplant emotional support is associated with longer survival after allogeneic hematopoietic stem cell transplantation

Emerging evidence suggests that psychosocial factors pre-transplant predict survival in cancer patients undergoing hematopoietic stem cell transplantation (HSCT). These studies, however, typically have small sample sizes, short-term follow ups or a limited panel of medical covariates. We extend this research in a large, well-characterized sample of transplant patients, asking whether patients' perceived emotional support and psychological distress predict mortality over 2 years. Prior to transplant, 400 cancer patients (55.5% males; 82.8% White; M =50.0 years; 67.0% leukemia, 20.0% lymphoma) were interviewed by a social caseworker, who documented the patients' perceived emotional support and psychological distress. Subsequently, patients received an allogeneic HSCT (51.0% matched-related donor, 42.0% matched-unrelated donor and 7.0% cord blood). HSCT outcomes were obtained from medical records. Controlling for demographic characteristics (age, sex, race/ethnicity and marital status) and medical confounders (disease type, conditioning regimen, remission status, cell dosage, donor and recipient CMV seropositivity, donor sex, comorbidities and disease risk), ratings of good emotional support pre-transplant predicted longer overall survival (hazard ratio (HR)=0.61, 95% confidence interval (CI), 0.42-0.91; P=0.013). Pre-transplant psychological distress was unrelated to survival, however (Ps>0.58). Emotional support was marginally associated with lower rates of treatment-related mortality (HR=0.58, CI, 0.32-1.05; P=0.073). These findings are consistent with the hypothesis that emotional support contributes to better outcomes following HSCT. Future studies should examine whether intervention efforts to optimize emotional resources can improve survival in cancer patients

Involvement of Drinking and Intestinal Sodium Absorption in Hyponatremic Effect of Atrial Natriuretic Peptide in Seawater Eels

Atrial natriuretic peptide (ANP) decreases plasma Na+ concentration and promtes seawater (SW) adaptation in eels. The hyponatremia may most probably be caused by increased branchial extrusion of Na+, but the mechanism has not been determined yet. The present study examined initially the effects of ANP on branchial Na+ efflux in vivo using isotopic 22Na. However, the efflux rate was not altered by infusion of a hyponatremic dose of ANP (5 pmol·kg−1·min−1). Therefore, we sought to examine whether the ANP-mediated hyponatremia is caused by a decrease in the uptake of Na+ from the environment. Since a decrease in drinking was highly correlated with a degree of hyponatremia, conscious SW eels were infused with dilute SW into the stomach at a normal drinking rate to offset the antidipsogenic effect of ANP. Under this regimen, the hyponatremic effect of ANP was abolished. Then, we examined the site of Na+ absorption in the alimentary tract by measuring the changes in ion composition of intraluminal fluid along the tract. Since Na+ was absorbed at the esophagus and anterior/middle intestine, a sac was prepared at each site and the effects of ANP were examined in situ in conscious SW eels. ANP infusion did not alter Na+ absorption at the esophagus, but it profoundly reduced the absorption at the intestine. Together with our previous finding that ANP does not alter renal Na+ excretion, we propose that ANP reduces plasma Na+ concentration in SW eels by inhibiting drinking and subsequent absorption of Na+ by the intestine