Recurrence of aplastic anemia following cyclophosphamide and syngeneic bone marrow transplantation: evidence for two mechanisms of graft failure

Two patients with aplastic anemia were treated with high-dose cyclophosphamide and marrow transplantation from their normal, genetically identical twin. Both patients rapidly recovered normal marrow function, but marrow failure recurred 13 and 18 months later. Because donor and host pairs were identical twins, these cases of graft failure could not have resulted from the usual cause of graft failure, ie, immunological reactivity of host cells against unshared minor histocompatibility antigens of the donor. These results imply that there are at least two mechanisms responsible for graft failure after marrow transplantation for severe aplastic anemia.     

A comparison of infant and toddler feeding practices of mothers with and without histories of eating disorders

This preliminary study surveyed the feeding practices of mothers with eating disorder histories through evaluation of mothers' reported feeding styles, child diet composition and restrictive special approaches to feeding. For this non‐randomised cohort study, 25 mothers with eating disorder histories and 25 mothers with no history of an eating disorder with children ages 6–36 months were selected such that the groups were similar based on child age group and child sex. Mothers were compared on self‐reported feeding style using the Infant Feeding Styles Questionnaire and on child diet composition and special feeding approaches using a modified version of the Toddler Diet Questionnaire from the Women, Infants, and Children program. Mothers with eating disorder histories scored lower on the restrictive feeding style subscale than controls. No significant differences were detected between groups in child diet including the percentage of mothers who breastfed, duration of breastfeeding, age at solid food introduction, daily number of meals or snacks or daily frequency of consumption of fruits, vegetables or protein foods. Mothers with eating disorder histories were more likely to report taking a restrictive special approach to feeding such as limiting processed foods or feeding organic foods only. Although mothers with eating disorder histories may not differ greatly from control mothers in terms of child diet composition (smaller effects may not have been detected due to limited sample size), they may be more likely to take restrictive special approaches to feeding which mirror dietary rules common in individuals with eating disorders.     

Gonadotropin-inhibitory hormone (GnIH): discovery, progress and prospect

A hypothalamic neuropeptide, gonadotropin-releasing hormone (GnRH), is the primary factor regulating gonadotropin secretion. An inhibitory hypothalamic neuropeptide for gonadotropin secretion was, until recently, unknown, although gonadal sex steroids and inhibin can modulate gonadotropin secretion. Findings from the last decade, however, indicate that GnRH is not the sole hypothalamic regulatory neuropeptide of vertebrate reproduction, with gonadotropin-inhibitory hormone (GnIH) playing a key role in the inhibition of reproduction. GnIH was originally identified in birds and subsequently in mammals and other vertebrates. GnIH acts on the pituitary and on GnRH neurons in the hypothalamus via a novel G protein-coupled receptor (GPR147). GnIH decreases gonadotropin synthesis and release, inhibiting gonadal development and maintenance. Such a down-regulation of the hypothalamo-pituitary-gonadal (HPG) axis may be conserved across vertebrates. Recent evidence further indicates that GnIH operates at the level of the gonads as an autocrine/paracrine regulator of steroidogenesis and gametogenesis. More recent evidence suggests that GnIH also acts both upstream of the GnRH system and at the level of the gonads to appropriately regulate reproductive activity across the seasons and during times of stress. The discovery of GnIH has fundamentally changed our understanding of hypothalamic control of reproduction. This review summarizes the discovery, progress and prospect of GnIH, a key regulator of vertebrate reproduction.     

Characterization of 13 polymorphic microsatellite loci for the dogtooth tuna Gymnosarda unicolor

We describe the isolation and development of 13 polymorphic microsatellite loci for the reef-associated dogtooth tuna Gymnosarda unicolor (Perciformes: Scombridae). The loci were tested on 20 individuals from a single population at Flinders Reef, located off the east coast of Australia. No evidence of linkage disequilibrium was detected between any pairs of loci. However, one locus showed a significant departure from Hardy–Weinberg equilibrium. The number of alleles per locus ranged from 2 to 12.     

Piliation of Invasive Streptococcus pneumoniae Isolates in the Era before Pneumococcal Conjugate Vaccine Introduction in Malawi

The pneumococcal pilus has been shown to be an important determinant of adhesion and virulence in mouse models of colonization, pneumonia, and bacteremia. A pilus is capable of inducing protective immunity, supporting its inclusion in next-generation pneumococcal protein vaccine formulations. Whether this vaccine target is common among pneumococci in sub-Saharan Africa is uncertain. To define the prevalence and genetic diversity of type I and II pili among invasive pneumococci in Malawi prior to the introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) into routine childhood immunization, we examined 188 Streptococcus pneumoniae isolates collected between 2002 and 2008 (17% serotype 1). In this region of high disease burden, we found a low frequency of invasive piliated pneumococci (14%) and pilus gene sequence diversity similar to that seen previously in multiple global pneumococcal lineages. All common serotypes with pilus were covered by PCV13 and so we predict that pilus prevalence will be reduced in the Malawian pneumococcal population after PCV13 introduction.     

Improving Participant Understanding of Informed Consent in an HIV-Prevention Clinical Trial: A Comparison of Methods

Empirical research on informed consent has shown that study participants often do not fully understand consent information. This study assessed participant understanding of three mock consent approaches describing an HIV-prevention clinical trial in Lilongwe, Malawi prior to trial implementation. Pregnant women (n?=?297) were systematically selected from antenatal-care waiting lines and sequentially allocated to receive an enhanced standard consent form (group 1), a context-specific consent form (group 2), or context-specific counseling cards (group 3). Understanding of research concepts and study procedures was assessed immediately postintervention and at 1-week follow-up. At postintervention, participants in groups 2 and 3 understood more about research concepts and study procedures compared with group 1. Group 3 participants also understood more about study procedures compared with group 2. At follow-up, participants in groups 2 and 3 continued to understand more about research concepts and study procedures. Context-specific approaches improved understanding of consent information in this study.