A comparative study of phosphate binders in patients with end stage kidney disease undergoing hemodialysis.

In the present study, a comparative evaluation of the effects of calcium acetate, calcium carbonate, sevelamer hydrochloride and lanthanum carbonate was carried out in 120 patients with end stage kidney disease (ESKD) undergoing hemodialysis. Biochemical parameters, like serum phosphorous, serum calcium and serum alkaline phosphatase level and intact parathyroid hormone level, were measured. A statistically significant reduction in serum phosphorous, serum calcium, calcium × phosphorous and serum alkaline phosphatase level were observed with all phosphate binders during 3 months of treatment. Reduction in serum phosphorous were observed with calcium acetate (1.5 mg/dL), calcium carbonate (1.3 mg/dL), sevelamer hydrochloride (2.1 mg/dL) and lanthanum carbonate (1.79 mg/dL). The reduction of serum alkaline phosphatase was observed more commonly with sevelamer (107.37 IU/L) and lanthanum (104.33 IU/L) treatments than with calcium acetate (93.9 IU/L) and calcium carbonate (86.57 IU/L). There was no statistically significant change in serum calcium observed with sevelamer and lanthanum treatments, while calcium-based phosphate binders caused a significant rise in the serum calcium level. Serum intact parathyroid hormone level was significantly reduced with all phosphate binder treatments. This decline was highest with sevelamer and lowest with calcium carbonate. All treatments were well tolerated and safety profiles were consistent with previous reports in hemodialysis patients. It is concluded that all phosphate binders are safe and effective for the treatment of hyperphosphatemia in patients with ESKD undergoing hemodialysis. However, sevelamer hydrochloride seems to be superior among all with lowering incidence of hypercalcemia.

The effects of sexual selection on life-history traits: an experimental study on guppies.

Sexual selection is often prevented during captive breeding in order to maximize effective population size and retain genetic diversity. However, enforcing monogamy and thereby preventing sexual selection may affect population fitness either negatively by preventing the purging of deleterious mutations or positively by reducing sexual conflicts. To better understand the effect of sexual selection on the fitness of small populations, we compared components of female fitness and the expression of male secondary sexual characters in 19 experimental populations of guppies (Poecilia reticulata) maintained under polygamous or monogamous mating regimes over nine generations. In order to generate treatments that solely differed by their level of sexual selection, the middle-class neighbourhood breeding design was enforced in the monogamous populations, while in the polygamous populations, all females contributed similarly to the next generation with one male and one female offspring. This experimental design allowed potential sexual conflicts to increase in the polygamous populations because selection could not operate on adult-female traits. Clutch size and offspring survival showed a weak decline from generation to generation but did not differ among treatments. Offspring size, however, declined across generations, but more in monogamous than polygamous populations. By generation eight, orange- and black-spot areas were larger in males from the polygamous treatment, but these differences were not statistically significant. Overall, these results suggest that neither sexual conflict nor the purging of deleterious mutation had important effects on the fitness of our experimental populations. However, only few generations of enforced monogamy in a benign environment were sufficient to negatively affect offspring size, a trait potentially crucial for survival in the wild. Sexual selection may therefore, under certain circumstances, be beneficial over enforced monogamy during captive breeding.

Temporal change in inbreeding depression in life-history traits in captive populations of guppy (Poecilia reticulata): evidence for purging?

Inbreeding depression, which generally affects the fitness of small populations, may be diminished by purging recessive deleterious alleles when inbreeding persists over several generations. Evidence of purging remains rare, especially because of the difficulties of separating the effects of various factors affecting fitness in small populations. We compared the expression of life-history traits in inbred populations of guppy (Poecilia reticulata) with contemporary control populations over 10 generations in captivity. We estimated inbreeding depression as the difference between the two types of populations at each generation. After 10 generations, the inbreeding coefficient reached a maximum value of 0.56 and 0.16 in the inbred and control populations, respectively. Analysing changes in the life-history traits across generations showed that inbreeding depression in clutch size and offspring survival increased during the first four to six generations in the populations from the inbred treatment and subsequently decreased as expected if purging occurred. Inbreeding depression in two other traits was weaker but showed similar changes across generations. The loss of six populations in the inbred treatment indicates that removal of deleterious alleles also occurred by extinction of populations that presumably harboured high genetic load.

Rett syndrome and ageing: a case study.

PURPOSE: This case study of an elderly women with Rett syndrome is used to consider whether observed changes may be related to physiological processes involved in ageing or environmental adaptations, which is important for delivery of rehabilitation. METHOD: The life story of a woman with Rett syndrome who lived to the age of 60 is presented. It is based on medical records, older and more recent videotapes, and interviews with her sister and care staff. RESULTS: After 21 years without walking, following intensive physiotherapy, she regained the ability to walk without support. She also showed improvement in hand use a few years before she died. During the early regression she appeared to lose social interest. The interest improved after some time, but she remained wary of people she did not know. CONCLUSION: The walking and hand use indicate that these functions may have been present to a greater extent than assumed by people in the environment and that her poor function reflects dyspraxia and lack of opportunity and training rather than lack of ability. Although more studies of elderly women with Rett syndrome is needed to answer whether the observed changes were due to physiological processes involved in ageing or environmental adaptations, the present case story demonstrates that identification of females with Rett syndrome is important at all age levels.