Evidence for the role of EPHX2 gene variants in anorexia nervosa.

Anorexia nervosa (AN) and related eating disorders are complex, multifactorial neuropsychiatric conditions with likely rare and common genetic and environmental determinants. To identify genetic variants associated with AN, we pursued a series of sequencing and genotyping studies focusing on the coding regions and upstream sequence of 152 candidate genes in a total of 1205 AN cases and 1948 controls. We identified individual variant associations in the Estrogen Receptor-ß (ESR2) gene, as well as a set of rare and common variants in the Epoxide Hydrolase 2 (EPHX2) gene, in an initial sequencing study of 261 early-onset severe AN cases and 73 controls (P=0.0004). The association of EPHX2 variants was further delineated in: (1) a pooling-based replication study involving an additional 500 AN patients and 500 controls (replication set P=0.00000016); (2) single-locus studies in a cohort of 386 previously genotyped broadly defined AN cases and 295 female population controls from the Bogalusa Heart Study (BHS) and a cohort of 58 individuals with self-reported eating disturbances and 851 controls (combined smallest single locus P<0.01). As EPHX2 is known to influence cholesterol metabolism, and AN is often associated with elevated cholesterol levels, we also investigated the association of EPHX2 variants and longitudinal body mass index (BMI) and cholesterol in BHS female and male subjects (N=229) and found evidence for a modifying effect of a subset of variants on the relationship between cholesterol and BMI (P<0.01). These findings suggest a novel association of gene variants within EPHX2 to susceptibility to AN and provide a foundation for future study of this important yet poorly understood condition.

Biochemical and morphological changes in hepatic nuclear membranes produced by N-hydroxy-2-acetylaminofluorene.

The effect of N-hydroxy-2-acetylaminofluorene on the ultrastructure and synthesis of hepatic neclear membranes was evaluated in partially hepatectomized rats. The incorporation of L-[4,5-3H]leucine into two nuclear membrane fractions increased within 2 hr after hepatic resection and reached a peak at 20 hr. After partial hepatectomy, the decay of radioactivity in nuclear membrane proteins labeled with L-[4,5-3H]leucine revealed similar half-lives for the two membrane fractions when compared to those obtained from sham-operated animals. The protein concentration of the nuclear membrane fraction of higher density decreased sharply within 2 hr after partial hepatectomy and remained low throughout a 20-hr postoperative period. Polyacrylamide gel electrophoresis of both nuclear membrane fractions showed a similar composition. Nine proteins were resolved, varying from 21,000 to 190,000 daltons. The two major protein bands were in the range of 50,000 and 70,000 daltons, respectively. Treatment of partially hepatectomized animals with N-hydroxy-2-acetylaminofluorene showed marked dilation of the nuclear envelope and rough endoplasmic reticulum in situ upon electron microscopic examination. Vacuolization and evagination of the perinuclear membranes were also noticeable in isolated nuclei obtained from carcinogen-treated rats. Inhibition by N-hydroxy-2-acetylaminofluorene of the incorporation of L-[4,5-3H]leucine into the nuclear membranes was dose-dependent and remained depressed throughout a 60-min labeling period. These results suggest that the inhibitory effects on RNA and protein synthesis previously shown to be produced by this arylhydroxylamine hepatocarcinogen may lead to disruption of the morphology and synthesis of the nuclear envelope.

Leptin, neuropeptide Y, and peptide YY in long-term recovered eating disorder patients.

BACKGROUND: Disturbances of leptin, neuropeptide Y (NPY), and peptide YY (PYY) have been found in women who are ill with anorexia or bulimia nervosa. It is not certain whether peptide disturbances are cause or consequence of eating disorders. METHODS: Plasma leptin and cerebrospinal fluid leptin, NPY, and PYY concentrations were measured in women who were recovered from anorexia or bulimia nervosa to determine whether alterations persisted after recovery. RESULTS: NPY, PYY, and leptin concentrations were similar across all diagnostic groups. CONCLUSIONS: Alterations in NPY, PYY, and serum leptin concentrations are probably secondary to pathological eating behaviors. Alterations of these peptides are unlikely to be trait-related disturbances that contribute to the etiology of eating disorders.

Long-term exercise patterns and immune function in healthy older women. A report of preliminary findings.

The purpose of this study was to examine the relationship between active versus inactive lifestyle and immunocompetence in older women. A sample of 46 independently dwelling, ambulatory and mentally alert women 60-98 years was examined, 25 who rated themselves as 'active' and 21 who rated themselves as 'inactive'. Lymphocyte subpopulations were analyzed by flow cytometry using selected monoclonal antibodies. The self-reported active subjects (also validated by their current unsolicited participation in a formal exercise class) demonstrated significantly higher percent change in CD25 mitogen stimulated lymphocytes (P = 0.0335) than those who reported themselves to be sedentary.

The uptake of LDL-IC by human macrophages: predominant involvement of the Fc gamma RI receptor.

The incubation of human macrophages with antigen antibody complexes prepared with rabbit anti-LDL and human LDL (LDL-IC) is followed by ingestion of those immune complexes (IC), massive cholesterol ester accumulation, cytokine release and overexpression of the LDL receptor. The massive accumulation of cholesterol esters and overexpression of the native LDL receptor are specifically induced by immune complexes containing native or modified LDL, but not by any other type of IC. We report the results of a series of experiments aimed at defining the receptor preferentially involved in LDL-IC uptake. Flow cytometry studies using CD16, CD32 and CD64 monoclonal antibodies showed a sharp reduction on the expression of CD64 (Fc gamma RI) both by human monocyte-derived macrophages and THP-1 cells after incubation with LDL-IC, suggesting preferential engagement of this type of Fc receptor. Blocking experiments with aggregate-free IgG1 and CD32 monoclonal antibody confirmed that blocking Fc gamma RI prevented both LDL-IC uptake and the upregulation of LDL receptors on THP-1 cells. In contrast, blocking Fc gamma RII did not affect either the uptake of LDL-IC or the expression of LDL receptors on the same cells. The preferential engagement of Fc gamma R-I by LDL-IC suggests a biological difference of LDL-IC relative to other types of IC and opsonized particles. The precise molecular mechanism(s) responsible for the paradoxical upregulation of LDL receptor after the uptake of LDL-IC remain to be elucidated.

Cytochalasin A inhibits B-lymphocyte capping and activation by antigens.

Cytochalasin B (CB) has been shown to be a potent depressant of the antigen-induced clone expansion and terminal differentiation of mouse B-lymphocytes to antibody-forming cells. This effect could be the result of the microfilament-disrupting effect of CB with subsequent inhibition of antigen-sIg complex redistribution, a series of events which seems to be necessary for B-lymphocyte activation. CB is not very active in depressing capping and will inhibit glucose transport. To further investigate the mechanism of action of cytochalasins, the effect of cytochalasin A (CA) on cap formation and plaque-forming cell generation was studied, since CA is less inhibitory of glucose transport and more inhibitory of cap formation. The results presented here indicate that complexes of anti-Ig-sIg will be prevented from capping by as little as 1 microgram of CA, a quantity sufficient to depress markedly the generation of plaque-forming cells to SRBC in culture. These results further confirm our conclusion that the depression of B-lymphocyte activation may be related to the depression of cap formation. It also strongly suggested that inhibition of glucose transport can be regraded as a negligible factor in this depression.

Depression of direct plaque-forming cell response in mouse spleen cell cultures by aggregated IgG2b-induced factors.

Mouse spleen cells were treated with concanavalin A (Con A) or aggregated mouse IgG2b for 48 h in culture. When cells thus treated were added to fresh mouse spleen cell cultures immunized with SRBC they depressed the response of B lymphocytes as measured by enumerating plaque forming cells (PFC) on the fourth day of culture. When supernatant from cells cultured with IgG2b was added to immunized cultures this resulted in depression of PFC generation similar to that observed by addition of treated cells. The depression observed was essentially in the same range as that observed by addition of Con A treated cells or their supernatant. These observations extend previous work suggesting that IgG2b-induced PFC depression may result from activation of suppressor T cells with elaboration of soluble suppressor factors. This mechanism of immunomodulation may be important in the pathogenesis of immune complex disorders.

Age-related mortality and adherent splenic cell mediator production to endotoxin in the rat.

Rat neonatal mortality to endotoxin and age-related changes in adherent splenic cell mediator production in vitro were investigated. Neonatal rat pups, 24, 48, 96, and 216 h old or maternal adult rats were administered doses of Salmonella enteritidis endotoxin, (.024 mg to 7.5 mg/kg) and survival was monitored for 72 h. Mortality demonstrated high sensitivity (p < .05) of neonates to endotoxin (particularly 24 h old neonates). Endotoxin administration .6 mg/kg intracardiac) produced a 100% lethality in 24 h neonates (p < .05) versus 23% or less lethality in the 48 to 216 h old age group. Endotoxin administration (.4 mg/kg subcutaneous) also produced 100% lethality in 24 h old neonates compared with reduced mortality versus older age groups. Endotoxin in vitro stimulated (p < .05) adherent splenic cell thromboxane (TX)B2, interleukin-6, and nitrite production in most groups. Splenic cell nitrite production was higher (p > .05) in the 24 h old neonates, but lower in 48 h and 96 h old groups compared with maternal adults. Splenic cell TXB2 production was higher (p < .05) in the 24 h and 216 h old neonates relative to maternal adults. In conclusion, 24 h old rat pups are more susceptible to endotoxic shock than older age groups and adults, and exhibit altered production of the cellular mediators nitric oxide and TXB2.

Cataplexy and the switch process of multiple personality disorder.

A case history is presented of an 18-year-old male with dissociative disorder and polysubstance abuse. The patient was observed to switch between three personalities, and the personality changes were often associated with symptoms of cataplexy. Both dissociative episodes and cataplexy are associated with strong affective stimuli. Similar reports in the literature are briefly reviewed.

Psychoneuroimmunology: where are we, where are we going?

We have reviewed briefly the current status of research on central nervous system-immune system interactions, focusing attention on the neural and humoral pathways by which CNS and IS communicate and interact and on the effects of stress and psychiatric illness on immune function. It is evident that CNS-IS communication occurs by direct innervation of lymphoid organs and by means of hormones, neuropeptides and cytokines. There is also clear evidence that humoral substances each of which were thought to be the product of one specific cell type are elaborated and secreted by a variety of cell types. This observation suggests a new unified concept of CNS-IS interactions with mediators of these interactions being produced ubiquitously and acting on cells of the two systems. In examining the effects of stress on IS it has become apparent that stress of various types can have a depressive effect on immune functions, primarily at the level of T lymphocytes and NK cells. This suggests that the defense mechanisms affected by stress are those which are responsible for cytotoxic effector responses. These findings are interesting in that they support older studies implicating stress in the pathogenesis and/or the clinical course of neoplastic diseases. Further support for a role of stress-induced immunodepression in morbidity comes from a very interesting, recent prospective study showing that stress will affect susceptibility to viruses. Finally, exploration of the mechanisms of stress-induced immunodepression, suggests that a variety of mediators which regulate lymphocyte interactions and activation may be affected, perhaps at the level of gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunophenotypic analysis of non-Hodgkin's lymphomas.

Flow cytometric cell analysis with fluorescence-labeled antibodies has become a very useful methodology for the immune phenotyping of lymphocytes. The continued evaluation of lymphocyte cell surface antigens has been of value in this respect by providing a clear picture of lymphocyte differentiation steps. Thus it is now possible to precisely identify lymphocytes of abnormal phenotype which may represent malignant cells. Detection of monotypic populations of lymphocytes represents a monoclonal expansion of a lymphocyte subset which is the hallmark of malignancy. In the case of B cell lymphoma, detection of monotypic populations rests on the finding of a monoclonal expansion of a cell type bearing one type of light chain and of heavy chain and/or one of the specific B lymphocyte differentiation antigens. The diagnosis of T cell malignancy is more difficult to establish and a diagnosis of T cell lymphoma rests on the finding of an abnormal phenotype. Thus flow cytometry in combination with histomorphologic examination is a useful technique for the more precise diagnosis of lymphomas and for the establishment of treatment protocols.

Effect of beta-3-Thienylalanine on Antibody Synthesis IV. Suppression of the Immune Response in Mice.

The analogue of phenylalanine, beta-3-thienylalanine (beta-3-TA), inhibits the primary and secondary immune responses to sheep red blood cells in CBA mice fed with phenylalanine-free diet. The optimal dose of beta-3-TA needed to obtain maximum immunosuppression with minimal toxicity is 250 mg per kg per day. The drug is maximally effective when administered for 7 days, beginning 2 days prior to primary immunization. With these experimental conditions, the antibody titers and the numbers of direct and indirect plaque-forming cells are greatly reduced during the primary and the secondary immune response.

Effect of -3-thienylalanine on antibody synthesis. V. Immunosuppression in mice by short diet and drug treatments.

The analogue of phenylalanine, beta-3-thienylalanine, depresses severely the primary and secondary immune response to sheep erythrocytes in mice when administered for a few days immediately before and after each injection of antigen. For this immunosuppression to occur, animals must be maintained on a phenylalanine-free diet during the times of drug injection since dietary phenylalanine will restore anamnestic response. With these experimental conditions, the number of direct and indirect plaque-forming cells is greatly reduced during immune responses. The finding that marked immunosuppression can be obtained with a very short drug and diet treatment points to a potential usefullness of the analogue as a powerful immunosuppressant.

Case reports of olanzapine treatment of anorexia nervosa.

Two females with severe anorexia nervosa were treated with olanzapine in open trials. Olanzapine was tried because it has caused weight gain in other patient groups. Both anorexic patients had a chronic illness and had failed multiple other treatments. Olanzapine administration was associated with weight gain and maintenance as well as reduced agitation and resistance to treatment. These case histories support further exploration of this class of drugs in anorexia nervosa.

Inhibition of antigen-induced B lymphocyte activation in vitro by cytochalasin B.

Cytochalasin B (CB), a fungal metabolite which disrupts microfilaments. and will inhibit capping and other events requiring membrane movement, suppressed the production of antibody-forming cells (AFC) in both mouse whole spleen cultures immunized with sheep erythrocytes (SRBC) and in mouse B lymphocyte cultures immunized with the thymic independent antigen DNP-Ficoll (DF). CB at a concentration of 1 mug/ml inhibited the AFC response by more than 90% in spleen cell cultures immunized with SRBC. This inhibition was completely reversible by removal of CB up to 24 hr after the start of culture. Spleen cells cultured in the presence of CB for the first 48 to 72 hr had a decreased AFC response similar to that of cultures in which SRBC had been withheld for thocyte the same period of time. Incubating whole spleen cell or B lymphocyte cultures immunized with DF for as short as 6 hr decreased the AFC response more than 60%. Antibody secretion, cell viability, and antigenicity of the SRBC and DF were not affected by CB. The results of these experiments favor the concept that movement of surface receptors is necessary in activating lymphocytes to differentiate into AFC. The differential response to CB observed in SRBC and DF stimulated cultures makes the technique employed a useful tool to study membrane events occuring between antigen interaction with surface receptor and the initiation of differentiative events.