Evaluation of platelet concentrates prepared from buffy coats and stored in a glucose-free crystalloid medium

Comparison was made between platelet concentrates prepared from pools of buffy coats removed from standard blood donations and stored in a glucose-free, commercially available crystalloid solution (BC-PCs) and standard platelet concentrates prepared from platelet-rich plasma (PRP-PCs). Platelet yield in BC-PCs and PRP-PCs was 59 and 75 percent of donated platelets, respectively. The number of total white cells in 1 BC-PC unit, prepared from a pool of 7 buffy coats, was 21 x 10(6), i.e., 50 times lower than that of 7 units of PRP-PCs. The in vitro values of adequate platelet quality were maintained for 10 days in BC-PCs stored in 1000-mL polyolefin bags. Prolonged bleeding times were reduced or corrected in three of three thrombocytopenic leukemic patients evaluated before and after transfusion of stored BC-PCs. Pretransfusion and 1- and 24-hour posttransfusion median platelet counts in 57 leukemic recipients during 4 months of routine transfusion of BC-PCs (n = 93) were 14, 35, and 27 x 10(9) per L, while those of PRP-PCs (n = 246) were 13, 37, and 31 x 10(9) per L, respectively. No reactions to BC-PCs were reported, but a 1.3 percent rate of reaction to PRP-PC transfusions was reported. This study indicates that BC-PCs are a good alternative to PRP-PCs for platelet support of thrombocytopenic patients.     

Dyspnea and 8-year mortality among elderly men and women: The PAQUID cohort study

PAQUID is an epidemiological cohort which aims to study cerebral and functional factors of ageing. We have examined the relationship between dyspnea level at entrance into this cohort and mortality occurring during the subsequent 8 years. Dyspnea was evaluated by a questionnaire derived from a Fletcher's five-degree scale. Mortality was recorded during follow-up according to its date and cause. Of 2762 subjects (98.9%) initially giving their dyspnea level, 935 (33.5%) had died 8 years later including 444 (40%) men and 491 (29.4%) women. Mortality was closely related to dyspnea level (p < 0.0001) both in men and women, especially for grade 3 and over, even after adjusting on age, sex, smoking history and former occupation. These results show that dyspnea grade 3 or higher is an important predictive symptom of mortality, thus suggesting that this is a threshold defining the dyspneic subject.     

The role of leptin in human growth and puberty

Experimental animal studies demonstrate the effects of leptin on appetite, weight gain and metabolism. The biological effects of leptin in human adults are still to be determined, but recent reports show that congenital leptin deficiency leads to hyperphagia and excessive weight gain from early infancy as well as failure of pubertal onset in adolescence. Our recently reported data from two longitudinal cohorts suggest a role for leptin in the normal regulation of childhood weight gain, maturation and the development of secondary sexual features and body composition. Low leptin levels in cord blood closely reflected decreased adiposity at birth and stringly predicted high rates of weight gain in infancy and cath-up growth. In adolescents, leptin levels rose gradually with age prior to puberty, suggesting that a threshold effect may trigger puberty. In girls, low leptin levels at the start of puberty predicted large gains in the percentage of fat mass, perhaps suggesting a role in the preparation for childbearing.     

Turner syndrome: a pattern of early growth failure

The purpose of this study was to determine the pattern of early growth in girls with Turner syndrome. Analysis was performed on a total of 464 longitudinal measurements of height, obtained from birth to 8 years of age from 37 girls with Turner syndrome who did not have significant cardiac disease or autosomal abnormalities. All data were obtained prior to the initiation of any hormonal therapy. Mean height SDS fell from -0.5 at birth to -1.5 at age 1 year and -1.8 at age 1.5 years. Growth curves fitted using the first two components of the infancy-childhood-puberty model of growth revealed that growth failure was due to (a) mild growth retardation in utero , (b) slow growth during infancy, (c) delayed onset of the childhood component of growth and (d) slow growth during childhood. Physicians should consider the diagnosis of Turner syndrome in any girl with an unexplained failure to thrive or with short stature, even during the first 2 years of life.     

Restoration of spermatogenesis by hormone treatment after cytotoxic therapy

Cytotoxic therapy is effective in treating various cancers, but many of the agents used can cause sterility in men, regardless of the age at which they were treated. Originally, it was thought that infertility in individuals who had undergone cytotoxic therapy resulted from the destruction of stem spermatogonia. However, studies using rats suggest that some stem spermatogonia can survive cytotoxic therapy and that infertility is caused by the inability of these spermatogonia to differentiate. The author believes that the failure of these cells to differentiate may be related to the high levels of intratesticular testosterone encountered in these situations. In rats that have previously received cytotoxic therapy, the administration of a gonadotrophin-releasing hormone (GnRH) agonist restores the ability of spermatogonia to differentiate, and as a result normal spermatogenesis returns. This finding suggests that GnRH agonists show promise as treatment for male sterility induced by cytotoxic therapy, although further studies are required.     

Identification of mutations in the connexin 26 gene that cause autosomal recessive nonsyndromic hearing loss

Mutations in the Cx26 gene have been shown to cause autosomal recessive nonsyndromic hearing loss (ARNSHL) at the DFNB1 locus on chromosome 13q12. Using direct sequencing, we screened the Cx26 coding region of affected and nonaffected members from seven ARNSHL families either linked to the DFNB1 locus or in which the ARNSHL phenotype cosegregated with markers from chromosome 13q12. Cx26 mutations were found in six of the seven families and included two previously described mutations (W24X and W77X) and two novel Cx26 mutations: a single base pair deletion of nucleotide 35 resulting in a frameshift and a C-to-T substitution at nucleotide 370 resulting in a premature stop codon (Q124X). We have developed and optimized allele-specific PCR primers for each of the four mutations to rapidly determine carrier and noncarrier status within families. We also have developed a single stranded conformational polymorphism (SSCP) assay which covers the entire Cx26 coding region. This assay can be used to screen individuals with nonsyndromic hearing loss for mutations in the CX26 gene. Hum Mutat 11:387–394, 1998. © 1998 Wiley-Liss, Inc.