Puberty as a critical risk period for eating disorders: A review of human and animal studies

This article is part of a Special Issue “Puberty and Adolescence”.     

Association study in eating disorders: TPH2 associates with anorexia nervosa and self‐induced vomiting

Twin studies suggest that genetic factors play a substantial role in anorexia nervosa (AN) and self‐induced vomiting (SV), a key symptom that is shared among different types of eating disorders (EDs). We investigated the association of 25 single nucleotide polymorphisms (SNPs), capturing 71–91% of the common variance in candidate genes, stathmin (STMN1), serotonin receptor 1D (HTR1D), tryptophan hydroxylase 2 (TPH2) and brain‐derived neurotrophic factor (BDNF), with AN and EDs characterized by regular SV. The first allele frequencies of all the SNPs were compared between a Dutch case group (182 AN, 149 EDs characterized by SV) and 607 controls. Associations rendering P‐values < 0.05 from this initial study were then tested for replication in a meta‐analysis with two additional independent ED case–control samples, together providing 887 AN cases, 306 cases with an ED characterized by SV and 1914 controls. A significant effect for the minor C‐allele of tryptophan hydroxylase 2 rs1473473 was observed for both AN [odds ratio (OR) = 1.30, 95% CI 1.08–1.57, P < 0.003] and EDs characterized by SV (OR = 1.52, 95% CI 1.28–2.04, P < 0.006). In the combined case group, a dominant effect was observed for rs1473473 (OR = 1.38, 95% CI 1.16–1.64, P < 0.0003). The meta‐analysis revealed that the tryptophan hydroxylase 2 polymorphism rs1473473 was associated with a higher risk for AN, EDs characterized by SV and for the combined group.     

Immunocytochemical localization of S-100 protein in the hypophysis and saccus vasculosus of the elasmobranchs Mustelus manazo and Scyliorhinus torazame

Summary S-100 protein-immunoreactive cells were demonstrated by immunocytochemical procedures in the hypophysis and saccus vasculosus of two species of elasmobranchs (Mustelus manazo and Scyliorhinus torazame). In the saccus vasculosus of M. manazo, immunoreactivity was detectable exclusively in the fibrous portions interposed between the epithelial layer and the blood vessels. In the neurohypophysis, tanycytes and astrocytes of the median eminence were immunostained, but only a few labeled cells were found in the neurointermediate lobe. In S. torazame, the neurohypophysis displayed a similar distribution of immunoreactivity, but there were no labeled cells in the saccus vasculosus. In both species, none of the glandular cells of the hypophysis displayed immunoreactivity. Electron-microscopic examination showed that the immunostained cells in the saccus vasculosus correspond to astrocytes.     

Immunohistochemical localization of neuropeptide Y-like substance in the brain and hypophysis of the brown hagfish,Paramyxine atami

The distribution of neuropeptide Y-like immunoreactivity in the brain and hypophysis of the brown hagfish, Paramyxine atami, was examined by use of the peroxidase-antiperoxidase method. Immunoreactive cells were found in two areas of the brain, the nucleus hypothalamicus of the diencephalon and the ventrolateral area of the caudal tegmentum, at the level of the nucleus motorius V–VII. The labeled cells of the nucleus hypothalamicus were loosely grouped and recognized as bipolar neurons. Immunolabeled fibers were widely distributed in the brain, showing the highest density in the diencephalon. They were sparse, or absent, in the olfactory bulb, habenula, primordium hippocampi, neurohypophysis, corpus interpedunculare, and dorsolateral area of the medulla oblongata. The fibers appeared to project exclusively from the ventral hypothalamus to various other portions of the brain: the anterolateral areas of the telencephalon via the basal hypothalamus, the pars dorsalis thalami, the dorsocaudal region of the mesencephalon, and the ventromedial portions of the tegmentum and anterior medulla oblongata. These findings suggest that, in the brown hagfish, NPY-like substance is involved in neuroregulation of various cerebral areas, but it may be of little significance in the control of pituitary function.     

Leptin prevents the fall in plasma osteocalcin during starvation in male mice

Plasma osteocalcin, a marker of osteoblastic activity, is reduced in starvation, malnutrition, and anorexia nervosa, resulting in low bone turnover osteoporosis. Contradictory findings about the role of leptin as a link between nutritional status and bone physiology have been reported. We demonstrate that leptin-deficient ob/ob and leptin-resistant db/db male mice have increased plasma osteocalcin, and that in male ob/ob mice osteocalcin is not decreased by starvation, unlike control mice. Intraperitoneal leptin administration increased plasma osteocalcin in male ob/ob mice, and prevented its fall during 24h fasting and 5 days of food restriction in normal male mice. This effect may be mediated via actions on the hypothalamic-pituitary-testicular or -growth hormone axes, or a direct action on osteoblasts. These studies support the hypothesis that the fall in leptin during starvation and weight loss is responsible for the associated reduction in osteoblast activity, and suggest a role for leptin in regulating bone turnover.     

神经性厌食99mTc-ECD局部脑血流变化初探

神经性厌食(Anorexia Nervosa,AN)是一种病因未明的心理行为综合症,社会文化及生物学因素间的交互作用被认为是该病的病因,脑成像体现出一些病理相关改变,但国内尚未见针对此病的成像报道。为给临床辅助诊断AN提供依据,采用经济、易获得的脑功能显像技术——单光子发射计算机断层显像(Single Photon Emission Computed Tomography,SPECT),扫描3位典型青年女性AN患者的大脑。通过统计参数图(Statistical Parametric Mapping,SPM2),基于体素的局部脑血流灌注分析,与25名正常青年女性脑图相比较发现,患者的前扣带和前额内侧、双侧额叶背外侧、后顶叶、颞叶中上部和小脑血流灌注降低,下丘脑、双侧颞叶中下部血流灌注增高,可能与神经递质回路有关,提示社会学因素可能只是该病的诱因,而生物学人格易感性才是该病的主要原因,同时说明SPECT脑血流成像有助于AN的临床辅助诊断。     

Morphometric classification of the neurosecretory granules in the rat pars nervosa

Summary The distribution of the diameters of the neurosecretory granules in the rat pars nervosa (measured from electron micrographs taken at 40 000 × ) was compared among axons by nonparametric statistical methods and the axons were classified into five groups with median granule diameters of 143, 155, 167, 180 and 193 nm. We suggested that these five axon types carried different secretory substances contained in the pars nervosa. This investigation is supported by a grant from the Population Council, New York and grant from the Ministry of Education. Authors are grateful to Japan Electron Optics Laboratory Company for their technical assistance with the electron microscopy and to Miss Kazue Yamamoto for her help in preparing the figures.     

Not Your “Typical Island Woman”: Anorexia Nervosa is Reported Only in Subcultures in Curaçao

Anorexia nervosa (AN), once thought to be a problem of wealthier, Western countries has now been documented in survey studies and case reports across geographic and economic groups; however, few epidemiological studies including interview have been done on these populations. We report on a comprehensive study on Curaçao, a Caribbean island in economic transition, where the majority of the population is of predominantly black African origin. As part of an epidemiological study on the island of Curaçao indigenous cases of AN were identified. Participants were interviewed and asked to complete standardized measures of eating behaviors and cultural attitudes. In addition, matched controls completed the same measures and were seen in a focus group to assess their knowledge of eating disorders and perceived current and future challenges to young Curaçao women. Six of the nine indigenous cases of AN were successfully traced; all were of mixed race. No cases of anorexia were found among the majority black population. The women with AN were from the high-education and high-income sectors of the society and the majority had spent time overseas. The women with a history of anorexia reported higher levels of perfectionism and anxiety than the matched controls. All of the women reported challenges to maintaining an active professional and personal life and viewed themselves as different from the norm. Women who presented with AN evidenced vulnerability to a triple threat to identity formation: (1) they were of mixed race, aspiring to fit into the mobile elite (and mostly white) subgroup while distancing themselves from the black majority; (2) they had the means for education and travel that left them caught between modern and traditional constructs of femininity; and (3) they had lived overseas, and therefore struggled upon reentry with the frustrations of what was possible within the island culture. The race, class and overseas exposures of the women with anorexia were anything but typical on the island. Cases of anorexia in other developing countries may similarly be limited to specific subgroups, which require specialized treatment and planning efforts.     

Binge Eating Behavior in Patients with Eating Disorders

The purpose of this study was to determine whether the objectively observed binge eating behavior of obese subjects meeting the proposed DSM-IV criteria for binge eating disorder would be similar to that observed in patients with bulimia nervosa. Non-obese patients with bulimia nervosa (BN), obese subjects with binge eating disorder (BED), obese and non-obese women without eating disorders were each instructed to binge eat single- and multiple-item meals. In the multiple-item meal, the obese subjects with BED ate significantly more (1515 kcal) than obese subjects without BED (1115 kcal), but they ate less than the normal-weight bulimic patients (2680 kcal). The non-obese controls ate amounts similar to the obese non-binge-eating-disordered group (1093 and 1115.2 kcal, respectively). In the single-item meal, consisting of ice cream, patients with BN ate significantly more than any other group (1307 kcal), while obese subjects with or without binge-eating disorder ate significantly more (762 kcal) than non-obese controls (308 kcal). This study has demonstrated that although both BN and BED are characterized by recurrent episodes of binge eating, quantitatively there appear to be differences between the eating disturbances in the two disorders. Because single- and multiple-item meals differ in external cues, these results also suggest that the obese subjects with BED may be disinhibited by external cues, while obese subjects without BED may be inhibited by external cues.     

The neurohypophysis of the crested newt

Summary In the crested newt, the ultrastructural organization of the pars nervosa is analogous to that already known in non-mammal tetrapods. An orderly array of ependymal cells makes up the inner limiting layer while less abundant pituicytes are irregularly distributed within this organ. Light and dark pituicytes can be distinguished on the basis of the relative density of the cytoplasmic matrix and the distribution of the cell organelles.Both the ependymal cells and pituicytes are rich in dense bodies and possess extensive processes which ramify among the nerve fibers, often reaching the pericapillary space which they can line for long distances.The main components of the pars nervosa are nerve fibers and nerve terminals (type A), containing electron dense granules 1200–2000 Å in diameter together with clear vesicles averaging 250–400 Å. These fibers are likely to correspond to the aldehyde fuchsin positive neurosecretory fibers revealed by light microscopy. Differences in the granule size within the fibers and terminals lead to further recognition of two subgroups (A₁ and A₂).Other fibers and terminals (type B) containing clear vesicles and granular vesicles 600 to 1000 Å in diameter, possibly of aminergic type, are also encountered. These fibers are rare and can be seen only in the portion of the pars nervosa near the pars intermedia of the adenohypophysis.Lastly, fibers and terminals containing only clear vesicles ranging from 250 to 400 Å (type C) are occasionally found.Nerve endings are often formed by type A fibers on the perivascular space and on the perivascular processes of the ependymal cells and pituicytes. In agreement with recent findings available in the literature, the occurrence of synaptoid contacts between these terminals and both pituicytes and ependymal cells may confirm the active role of these cells in transport and release of neurosecretion.Work supported by a grant from the Consiglio Nazionale delle Ricerche.We are gratefully indebted to Dr. G. Gendusa and P. Balbi for technical assistance, dr. G. E. Andreoletti for statistical analysis.