Differences in Body Image and Depression Among Obese Women With and Without Binge Eating Disorder

Obese individuals with binge eating disorder (BED) differ from obese non-binge eating (NBE) individuals in a number of clinically relevant ways. This study examined attitudinal responses to various measures of body image in women seeking obesity treatment, by comparing NBE participants (n=80) to those with BED (n=48). It was hypothesized that women with BED would demonstrate greater attitudinal disturbance of body image compared to NBE individuals. It was further hypothesized that significant differences between groups would remain after statistically controlling for degree of depression. Consistent with the primary hypothesis, BED participants reported significantly increased attitudinal disturbance in body dissatisfaction and size perception compared to NBE participants. Although shared variance was observed between measures of depression and body image on some items, several aspects of increased body image disturbance remained after statistically controlling for depression. Treatment implications and recommendations for future research are discussed.     

Comparative mapping in Arabidopsis and Brassica, fine scale genome collinearity and congruence of genes controlling flowering time

The model dicotyledonous plant, Arabidopsis thaliana , is closely related to Brassica crop species. It is intended that information concerning the genetic control of basic biological processes in Arabidopsis will be transferable to other species. Genome collinearity and its potential to facilitate the identification of candidate genes in Arabidopsis homologous to genes controlling important agronomic traits in Brassica was investigated. Genetic mapping in B. nigra identified two loci influencing flowering time (FT), with loci on linkage groups 2 and 8 explaining 53% and 12% of the total variation in FT, respectively. The CO gene exerts an important control over FT in A. thaliana , and B. nigra homologues of CO probably also play an important role in regulating FT. B. nigra homologues of CO were identified on linkage groups 2 and 8, the homologue on group 2 was coincident with the major locus controlling FT while the homologue on group 8 was within the 90% confidence interval of the weaker FT gene. The CO homologue on group 2 exhibits abundant allelic variation suggesting that it naturally controls a wide range of flowering times. Fine-scale A. thaliana/B. nigra comparative mapping demonstrated short-range collinearity between the genomes of Arabidopsis and Brassica . Eleven DNA fragments spaced over a 1.5 Mb contig in A. thaliana were used as RFLP probes in B. nigra . Three collinear representations of the A. thaliana contig were identified in B. nigra , with one interrupted by a large chromosomal inversion. Collinearity over this range will allow the resources generated by the Arabidopsis genome project to facilitate map-based cloning in Brassica crops.     

Development of a new method for obtaining osteoclasts from endosteal surfaces

Summary Techniques for the isolation of ahhighly pure population of viable osteoclasts are limited. For this reason, we developed an isolation procedure that results in a high yield of osteoclast-like cells, up to 92% pure, from 3-wk-old chicken tibias. The unique feature of the method is the migration of cells from marrow-free endosteal surfaces to vitronectin-coated plates. The cells retain the osteoclast phenotype and remain viable in culture for a minimum of 1 wk. The cells were characterized and compared to two populations of authentic avian osteoclasts, which were isolated on the basis of association with fibronectin-coated plates. The cells contained substantial amounts of tartrate-resistant acid phosphatase. Alkaline phosphatase levels were negligible, suggesting little contamination by osteoblasts. Response to parathyroid hormone, dibutyryl cyclic adenosine monophosphate, calcitonin, acetazolamide, 17β-estradiol, and prostaglandin E₂ was evident, as detected by measuring acid production. The vitronectin-associating cells contained numerous mitochondria, had the ability to resorb bone in anin vitro bone slice assay, and specifically bound biotinylated vitronectin. At 5 d of culture, the cells demonstrated marginal multinuclearity, having two to three nuclei. A large number (∼1×10⁶ cells/tibia) of viable cells that exhibit characteristics of authentic osteoclasts can be obtained by the method described. Potentially, this method could be applied to other species.     

Mycoplasma orale infection affects K+ and Cl− currents in the HSG salivary gland cell line

Summary The relations between K⁺ channel and Cl⁻ channel currents and mycoplasma infection status were studied longitudinally in HSG cells, a human submandibular gland cell line. The K⁺ channel currents were disrupted by the occurrence of mycoplasma infection: muscarinic activation of K⁺ channels and K⁺ channel expression as estimated by ionomycin- or hypotonically induced K⁺ current responses were all decreased. Similar decreases in ionomycin- and hypotonically induced responses were observed for Cl⁻ channels, but only the latter decrease was statistically significant. Also, Cl⁻ currents could be elicited more frequently than K⁺ currents (63% of cases versus 0%) in infected cells when tested by exposure to hypotonic media, indicating that mycoplasma infection affects K⁺ channels relatively more than Cl⁻ channels. These changes occurred in the originally infected cells, were ameliorated when the infection was cleared with sparfloxacin, and recurred when the cells were reinfected. Such changes would be expected to result in hyposecretion of salivary fluid if they occurredin vivo.     

Isolation and preliminary characterization of gas1-1, a mutation causing partial suppression of the phenotype conferred by the gibberellin-insensitive (gai) mutation in Arabidopsis thaliana (L.) Heyhn

The semi-dominant gai mutation of arabidopsis confers a dark-green dwarf phenotype resembling that of gibberellin (GA)-deficient mutants. In contrast to GA-deficient mutants, gai mutants do not respond to GA treatments and accumulate higher levels of bioactive GAs than are found in wild-type controls. The gai mutation thus alters the responses of plant cells to GA, indicating that the GAI (wild-type) gene product is involved in GA reception and/or signal transduction. Here we describe the isolation and preliminary characterization of a mutation, gas1-1, which is not linked to gai and which partially suppresses the effect of the gai mutation. Double mutant, gai gas1-1, homozygotes are less severely dwarfed and lighter green than gai GAS1 controls. However, comparisons of the effects of treatments with exogenous GA demonstrate that gas1-1 does not increase the GA responsiveness of the gai mutant. Thus the gas1-1 mutation appears to reduce the GA-dependency of plant growth, and identifies a gene (GAS1) whose product is a candidate GA signal-transduction component.Abbreviations GA gibberellin - GA₃ gibberellic acid We thank Maarten Koornneef (Wageningen Agricultural University, The Netherlands) for providing mutant seed stocks; Mark Aarts and Bernard Mulligan (University of Nottingham, UK) for performing the -irradiation. This work was made possible by AFRC/BBSRC PMB Grants PG208/520 and PG208/0600, and by a grant from the Gatsby Charitable Foundation. P.C. was supported by a Human Capital and Mobility Fellowship from the EC.     

Improved production and stability ofE. coli recombinants expressing transketolase for large scale biotransformation

Summary TheE.coli tkt gene has been subcloned into high copy number vectors. In fed batch fermentations up to 4gL^–1 of soluble intracellular transketolase was produced representing 43% of the total cell protein. Increased plasmid stability during fed-batch fermentations was obtained by using kanamycin resistant pBGS vectors rather than the ampicillin resistant pUC vectors. Plasmid stability was maintained throughout growth in a complex medium without any selective pressure by incorporating thecer region fromColE1 into the expression construct.     

Amphiphysin II (SH3P9; BIN1), a Member of the Amphiphysin/Rvs Family, Is Concentrated in the Cortical Cytomatrix of Axon Initial Segments and Nodes of Ranvier in Brain and around T Tubules in Skeletal Muscle

Amphiphysin (amphiphysin I), a dominant autoantigen in paraneoplastic Stiff-man syndrome, is a neuronal protein highly concentrated in nerve terminals, where it has a putative role in endocytosis. The yeast homologue of amphiphysin, Rvs167, has pleiotropic functions, including a role in endocytosis and in actin dynamics, suggesting that amphiphysin may also be implicated in the function of the presynaptic actin cytoskeleton. We report here the characterization of a second mammalian amphiphysin gene, amphiphysin II (SH3P9; BIN1), which encodes products primarily expressed in skeletal muscle and brain, as differentially spliced isoforms. In skeletal muscle, amphiphysin II is concentrated around T tubules, while in brain it is concentrated in the cytomatrix beneath the plasmamembrane of axon initial segments and nodes of Ranvier. In both these locations, amphiphysin II is colocalized with splice variants of ankyrin3 (ankyrin_G), a component of the actin cytomatrix. In the same regions, the presence of clathrin has been reported. These findings support the hypothesis that, even in mammalian cells, amphiphysin/Rvs family members have a role both in endocytosis and in actin function and suggest that distinct amphiphysin isoforms contribute to define distinct domains of the cortical cytoplasm. Since amphiphysin II (BIN1) was reported to interact with Myc, it may also be implicated in a signaling pathway linking the cortical cytoplasm to nuclear function.     

Characterization of Myelin Basic Protein Charge Microheterogeneity in Developing Mouse Brain and in the Transgenic Shiverer Mutant

Abstract: Myelin basic protein (MBP) is a highly heterogeneous family of membrane proteins consisting of several isoforms resulting from alternative splicing and charge isomers arising from posttranslational modifications. Although well characterized in the bovine and human species, those in the mouse are not. With the availability of a number of transgenic and knockout mice, the need to understand the chemical nature of the MBPs has become very important. To isolate and characterize the MBP species in murine brain, two methods were adapted for use with the small amounts of MBP available from mice. The first was a scaled-down version of the preparative CM-52 chromatographic system commonly used to isolate MBP charge isomers; the second was an alkaline-urea slab gel technique that required five times less material than the conventional tube gel system and, from these gels, western blots were readily obtained. Murine MBP was resolved into two populations of charge isomers: the 18.5- and 14-kDa isoforms. Isolation and characterization of these charge isomers or components permitted us to assign possible posttranslational modifications to some of them. Component 1 (C-1), the most cationic isomer, had a molecular weight of 14,140.38 ± 0.79. C-2 consisted of two 14-kDa species, 14,136.37 ± 0.74 and 14,204.45 ± 0.70. Two variants, 14,215.57 ± 0.94 and 18,413.57 ± 0.76, constituted C-3. C-4, C-5, and C-8 (the least cationic isomer) each consisted of both 14- and 18.5-kDa isoforms. During myelinogenesis, the 18.5-kDa isoform appeared first (day 4); the 14-kDa isoform appeared at day 16 and subsequently became the dominant isoform. The transgenic shiverer mutant synthesized mainly the 18.5-kDa isoform, but none of the 14-kDa isoform, similar to the 4-day-old mouse. We concluded that the trangenic shiverer was able to initiate myelinogenesis with the 18.5-kDa isoform, but was unable to complete myelinogenesis because of the absence of the 14-kDa isoform.     

Comparison of Type 2 Inositol 1,4,5-Trisphosphate Receptor Distribution and Subcellular Ca2+ Release Sites that Support Ca2+ Waves in Cultured Astrocytes

Abstract: We have examined the mechanisms that underlie Ca²⁺ wave propagation in cultured cortical astrocytes. Norepinephrine evoked Ca²⁺ waves in astrocytes that began at discrete initiation loci and propagated throughout the cell by regenerative amplification at a number of cellular sites, as shown by very high Ca²⁺ release rates at these regions. We have hypothesized previously that domains displaying elevated Ca²⁺ release kinetics in astrocytes may correspond to sites of high inositol 1,4,5-trisphosphate receptor (InsP₃R) density. To examine this possibility, we compared the distribution pattern of endoplasmic reticulum (ER) and InsP₃Rs with Ca²⁺ release kinetics in subcellular regions during propagation of norepinephrine-evoked waves. 3,3'-Dihexyloxacarbocyanine iodide staining revealed that the ER in astrocytes exists as a meshwork of membranes extending throughout the cells, including fine processes. A specific antibody directed against type 2 InsP₃Rs (InsP₃R2) detected a 260-kDa band in western blotting of astrocyte membranes. Immunocytochemistry using this antibody stained the entire ER system in a punctate, variegated manner. When Ca²⁺ responses and InsP₃R2 immunofluorescence were compared in the same cell, domains of elevated Ca²⁺ response kinetics (high amplitude and rapid rate of rise) showed significant positive correlation with high local intensity of InsP₃R2 staining. It appears, therefore, that specializations in the ER responsible for discrete local Ca²⁺ release sites that support regenerative wave propagation include increased levels of InsP₃R2 expression.     

Temperature preference in two populations of juvenile coho salmon,oncorhynchus kisutch

Synopsis Two groups of coho salmon,Oncorhynchus kisutch, were raised under identical regimes to test the hypothesis that the group from a stream with lower and less variable temperatures would have a lower and less variable preferred temperature than would the group from a stream with warmer and more variable temperatures. The preferred (modal) temperatures in an electronic shuttlebox of coho salmon young from a relatively cool, groundwater-fed stream were slightly lower and less variable than those of young from a warmer and more heterothermal stream (mean = 9.6° C, range: 6–16° C vs. mean = 11.6° C, range: 7–21° C). However, there was a great deal of variation within and among individual fish. While some genetic variation in thermal preference may exist, the species seems best characterized as tolerant of relatively large temperature fluctuations.