Neonatal and adult myosin heavy chains form homodimers during avian skeletal muscle development.

Myosin isoforms contribute to the heterogeneity and adaptability of skeletal muscle fibers. Besides the well-characterized slow and fast muscle myosins, there are those isoforms that appear transiently during the course of muscle development. At a stage of development when two different myosins are coexpressed, the possibility arises for the existence of heterodimers, molecules containing two different heavy chains, or homodimers, molecules with two identical heavy chains. The question of whether neonatal and adult myosin isoforms can associate to form a stable heterodimer was addressed by using stage-specific monoclonal antibodies in conjunction with immunological and electron microscopic techniques. We find that independent of the ratio of adult to neonatal myosin, depending on the age of the animal, the myosin heavy chains form predominantly homodimeric molecules. The small amount of hybrid species present suggests that either the rod portion of the two heavy chain isoforms differs too much in sequence to form a stable alpha-helical coiled coil, or that the biosynthesis of the heavy chains precludes the formation of heterodimeric molecules.

Coupling of ATPase activity and motility in smooth muscle myosin is mediated by the regulatory light chain.

Smooth muscle myosin acts as a molecular motor only if the regulatory light chain (RLC) is phosphorylated. This subunit can be removed from myosin by a novel method involving the use of trifluoperazine. The motility of RLC-deficient myosin is very slow, but native properties are restored when RLC is rebound. Truncating 6 residues from the COOH terminus of the RLC had no effect on phosphorylated myosin's motor properties, while removal of the last 12 residues reduced velocity by approximately 30%. Very slow movement was observed once 26 residues were deleted, or with myosin containing only the COOH-terminal RLC domain. These two mutants thus mimicked the behavior of RLC-deficient myosin, with the important difference that the mutant myosins were monodisperse when assayed by sedimentation velocity and electron microscopy. The decreased motility therefore cannot be caused by aggregation. A common feature of RLC-deficient myosin and the mutant myosins that moved actin slowly was an increased myosin ATPase compared with dephosphorylated myosin, and a lower actin-activated ATPase than obtained with phosphorylated myosin. These results suggest that the COOH-terminal portion of an intact RLC is involved in interactions that regulate myosin's "on-off" switch, both in terms of completely inhibiting and completely activating the molecule.

Feline attractant, cis,trans-nepetalactone: metabolism in the domestic cat.

cis,trans-Nepetalactone, the biologically active component of catnip, was force-fed to the domestic cat. When the (14)C-labeled compound was fed, 86 to 94 percent of the radioactivity was recovered in the urine, 1 to 2 percent was found in the feces, and 1 to 12 percent was collected as carbon dioxide. The major (50 to 75 percent) metabolite was alpha-nepetalinic acid, which was excreted in the urine together with small amounts of dihydronepetalactone, unchanged cis,-trans-nepetalactone, and several unidentified compounds. No marked physiological or histological eflects were observed when 20 to 80 milligrams of cis, trans-nepetalactone was administered orally. This is the first report on the metabolism of a mammalian attractant.

Causes of injuries resulting in hospitalisation in Australia: assessing coder agreement on external causes.

OBJECTIVE: To assess extent of coder agreement for external causes of injury using ICD-10-AM for injury-related hospitalisations in Australian public hospitals. METHODS: A random sample of 4850 discharges from 2002 to 2004 was obtained from a stratified random sample of 50 hospitals across four states in Australia. On-site medical record reviews were conducted and external cause codes were assigned blinded to the original coded data. Code agreement levels were grouped into the following agreement categories: block level, 3-character level, 4-character level, 5th-character level, and complete code level. RESULTS: At a broad block level, code agreement was found in over 90% of cases for most mechanisms (eg, transport, fall). Percentage disagreement was 26.0% at the 3-character level; agreement for the complete external cause code was 67.6%. For activity codes, the percentage of disagreement at the 3-character level was 7.3% and agreement for the complete activity code was 68.0%. For place of occurrence codes, the percentage of disagreement at the 4-character level was 22.0%; agreement for the complete place code was 75.4%. CONCLUSIONS: With 68% agreement for complete codes and 74% agreement for 3-character codes, as well as variability in agreement levels across different code blocks, place and activity codes, researchers need to be aware of the reliability of their specific data of interest when they wish to undertake trend analyses or case selection for specific causes of interest.

Validity of the Eating Disorders Examination-Questionnaire when used with adolescents with bulimia nervosa and atypical bulimia nervosa.

OBJECTIVE: To validate the online questionnaire form of the Eating Disorders Examination (EDE-Q) against the interview version (EDE) in a clinic and community sample of adolescents with bulimia nervosa (BN) or atypical BN (eating disorder not otherwise specified with bulimic features - EDNOS-BN). METHOD: Adolescents with BN (N=58) or EDNOS-BN (N=37) completed the EDE over the telephone and the EDE-Q online. RESULTS: There were moderate to high correlations between the attitudinal scales. Eating was rated as more pathological on the EDE-Q than the EDE, except dietary restraint. As in research among adults, agreement between the two measures was low regarding binge eating episodes, but better for vomiting episodes. When compared with the EDE, the EDE-Q attitudinal scales were more valid for BN than for EDNOS-BN patients, and more valid for the clinic sample. CONCLUSION: The online version of the EDE-Q has partial validity for use with adolescents. The EDE-Q might be reporting a more accurate description of current status, as it avoids possible filtering and approval aspects.

Core beliefs and social anxiety in the eating disorders.

Social anxiety is a common comorbid problem in the eating disorders. The present study investigated whether specific types of core beliefs are common in eating-disordered individuals presenting with high levels of social anxiety. The participants were a group of 191 women meeting Diagnostic and Statistical Manual-IV (DSM-IV) criteria for an eating disorder. Young's Schema Questionnaire (YSQ-S) was used as a measure of core beliefs, while a brief version of the Fear of Negative Evaluation scale (Brief FNE) was used as a measure of social anxiety. The results showed that eating-disordered individuals with high levels of comorbid social anxiety report higher levels of socially-oriented core beliefs (abandonment; defectiveness/shame) than those who experience low levels of social anxiety. The findings highlight the potential importance of addressing core beliefs in specific groups of eating-disordered individuals. Implications for future research and clinical practice are discussed.

Unscheduled hospital admission following ambulatory gynecologic surgery.

OBJECTIVE: To identify causes of unscheduled admission following ambulatory gynecologic surgery. METHODS: We compared each patient admitted on an unscheduled basis with two patients who did not require admission. Thirty demographic and clinical factors were evaluated by univariate analysis. Significant factors (P less than .05) were then analyzed using multivariate stepwise logistic regression. RESULTS: During a 4-year period, 90 patients required unscheduled admission. This represented 3.64% of 2470 patients who underwent ambulatory gynecologic surgery. Factors associated with admission by multivariate analysis included: 1) previous abdominal surgery, 2) significant medical illnesses, 3) preoperative hemoglobin concentration, 4) general anesthesia, 5) procedure length, and 6) blood loss. Sensitivity was 60.0%, specificity was 90.6%, and the overall correct rate of prediction was 80.4%. Postoperative emesis, the most common reason for unscheduled admissions, occurred in 23.4% of patients. CONCLUSIONS: Previous abdominal surgery and significant medical illnesses are factors that cannot be altered preoperatively. The need for general anesthesia, procedure length, and blood loss are functions of the procedure and cannot be easily modified. Postoperative emesis may warrant further investigation. Successful antiemetic therapy may reduce unscheduled admissions.

Childhood emotional abuse and eating psychopathology.

The potential role of childhood emotional abuse (CEA) in the etiology and maintenance of eating psychopathology is reviewed. While childhood sexual and physical abuse have been hypothesized as risk factors in multifactorial models of eating disorders, a role for CEA has only recently been considered. Initial findings demonstrate a phenomenological link between CEA and eating psychopathology, and suggest that this association might be different to the links for other forms of trauma (i.e., CEA may have a relationship with a broader range of eating symptoms than sexual and physical abuse). However, the psychological processes that might account for such a link are not yet well understood. Potential cognitive and affective mediators are considered, with a particular emphasis upon low self-esteem and anxiety. A model is proposed, to act as a framework for further research into this field. The clinical implications of the research to date and of the proposed model are discussed.

See no evil, hear no evil, speak no evil: why do relatively few male victims of childhood sexual abuse receive help for abuse-related issues in adulthood?

This literature review explores the reasons why comparatively few adult males with a history of childhood sexual abuse are seen by professionals for help with difficulties relating to that abuse. Two potential explanations are discounted as myths-that relatively few males are sexually abused, and that abuse has little effect on males. However, it is suggested that society (including professionals and the victims themselves) has given credence to these myths. Male victims are relatively unlikely to disclose their experience of childhood abuse, and (as a coping strategy) they deny the impact of sexual abuse on their lives. Professionals fail to hypothesise that their male clients may have been abused, and do not create the conditions that would enable males to talk about the abuse. Blumer's (1971) model of the social construction of problems is applied to account for these beliefs and behaviours on the part of victims and clinicians. It is argued that the childhood sexual abuse of males has not yet acquired legitimacy as a problem recognised by society, thus lagging behind the abuse of females. In short, the "evil' of childhood sexual abuse in the male population is not being seen or heard by clinicians, and is not being recognised or talked about by victims. Clinical implications are considered.

Recurrent uncomplicated urinary tract infection: a review of psychological factors.

Urinary tract infection (UTI) is a very common medical disorder among women, and is a chronic, recurrent problem for a cluster of sufferers. The factors involved in the aetiology of recurrent UTI are not adequately understood. Most research and treatment has focused on the influence of medical factors, although clinical impressions suggest that psychological factors (behavioural and personality variables) may play an important role. Evidence is reviewed for the involvement of psychological factors in the aetiology and treatment of recurrent UTI in women. It is difficult to draw any clear conclusions concerning the role of such factors in recurrent UTI, given the relatively small amount of research to date and a number of methodological issues. Suggestions for appropriate methodology and research concerning the interplay of physical and psychological factors are made.

Sexual abuse as a factor in anorexia nervosa: evidence from two separate case series.

Evidence of a link between reported sexual abuse and specific eating behaviours was considered in 100 anorexic women. The women were assessed as part of case series from two separate clinics. There was a strong association between reported unwanted sexual experiences and purging behaviours (vomiting and/or abusing laxatives). Anorexics who did not purge had lower reported rates of abuse. The pattern and prevalence rate of reported abuse were similar in the two clinics, suggesting that the association was not a product of a specific method of eliciting disclosure. Implications for treatment and possible causal mechanisms behind this relationship are discussed.

Preliminary analysis of elasmobranch tissue using magnetic resonance imaging.

High resolution NMR images of sixgill shark (Hexanchus griseus) tissue from both horizontal and sagittal orientations are presented. Structures normally radiographically undetectable are visualised here with NMR. Proton density, spin-lattice and spin-spin relaxation time maps as well as various relaxation weighted images show selective enhancement of different tissue types. Quantitative analysis of major anatomical features in the shark head is provided.

Outcome of group cognitive-behavior therapy for bulimia nervosa: the role of core beliefs.

It is hypothesized that individuals who benefit less from CBT will be those who have more pathological core beliefs (unconditional beliefs, unrelated to food, shape and weight). Twenty bulimic women were treated using 12 sessions of conventional group CBT. Eating behavior and attitudes were assessed pre- and posttreatment. Core beliefs were assessed at the beginning of the programme, and were used as predictors of change across treatment (once any effect of pretreatment psychopathology was taken into account). Group CBT was effective, with reductions of over 50% in bulimic symptoms. Outcome on most indices was associated with pretreatment levels of pathological core beliefs. Possible reasons for these findings are discussed.

Bulimics' responses to food cravings: is binge-eating a product of hunger or emotional state?

This study examined the roles of hunger, food craving and mood in the binge-eating episodes of bulimic patients, and identified the critical factors involved in the processes surrounding binge-eating episodes that follow cravings. This was a prospective study of the binge-eating behaviour of 15 women with bulimia nervosa. The participants used food intake diaries and Craving Records to self-monitor their nutritional behaviour, hunger levels and affective state. Cravings leading to a binge were associated with higher tension, lower mood and lower hunger than those cravings not leading to a binge. Levels of tension and hunger were the critical discriminating variables. The findings of the study support empirical evidence and models of emotional blocking in binge-eating behaviour and challenge the current cognitive starve-binge models of bulimia. The role of food cravings in the emotional blocking model is discussed in terms of a classically conditioned motivational state. Implications for treatment are addressed.

Somatoform dissociation in eating-disordered patients.

This study investigated the role of somatoform dissociation in eating disorders and pathological eating behaviour, relative to the established association of eating pathology with psychological dissociation. The participants were 131 women with DSM-IV diagnoses of anorexic or bulimic disorders and 75 women who had no such disorder. Each woman completed measures of psychological and somatoform dissociation, as well as a measure of bulimic attitudes. The current presence or absence of specific bulimic behaviours was identified during the clinical interview. Levels of both forms of dissociation were higher in the women who had diagnoses of disorders with a bulimic component (bulimia nervosa; anorexia nervosa of the binge/purge subtype) than in the non-clinical or restrictive anorexic women. Somatoform dissociation showed particularly strong links with the presence of bulimic behavioural features (excessive exercise, laxative abuse, diet pill abuse, diuretic abuse) and with bulimic attitudes. The formulation and treatment of cases where there are bulimic features is likely to be enhanced by the assessment of somatoform dissociation.

Composition of bile acids in ruminants.

The bile acids found in sheep bile, beef bile, beef feces, sheep fetus bile, and beef fetus bile have been analyzed by using conventional techniques. Animals maintained on natural and purified diets were used. The bile acids are a complex mixture of isomeric hydroxy- and keto-5beta-cholanoic acids which were substituted at one or several of the carbon atoms 3, 7, and 12. Cholic acid is the predominant bile acid found in these species. Deoxycholic acid was the major product formed from cholic acid when the animals were on a natural diet but the concentration of 3alpha, 12alpha-dihydroxy-7-keto-5beta-cholanoic acid was elevated in the animals that were maintained on a high concentrated purified diet (without roughage). The fetus bile was found to contain nearly all of the bile acids found in the bile of the mature animal but in different concentrations.

Eating disorders and family interaction.

The McMaster Model of Family Functioning was used to compare women with eating disorders with a normal comparison group. The anorexia nervosa and bulimia nervosa groups showed similar perceived family pathologies but bulimics with no history of anorexia showed a pattern of family interaction that was more severely 'unhealthy' than that of the other clinical groups. The McMaster Model could be a useful tool in clinical assessment and in planning therapy in this particular area.

The relationship between parental bonding and core beliefs in anorexic and bulimic women.

OBJECTIVE: The role of core beliefs in the psychopathology of eating disorders has been considered in recent years. Young (1994) hypothesized that unhealthy core beliefs originate from the experience from the first few years of life. The aim of the present study was to consider whether perceived parental bonding might explain the development of such beliefs in eating disordered women. METHOD: The participants were 30 anorexics, 27 bulimics and 23 comparison women who completed measures of core beliefs and perceived parental bonding. RESULTS: There were significant differences in perceived parental bonding behaviours across groups. The association between parental bonding and core beliefs were much stronger in the anorexic group than that in either the bulimic or the control group. In particular, a perceived low level of parental care was predictive of the presence of some unhealthy core beliefs in anorexic women. CONCLUSION: Longitudinal research is needed to confirm these findings among anorexic and bulimic women. Clinically, these findings provide insight into the possible origins or core beliefs, and hence might aid their challenge in schema-focused cognitive therapy.

The utility of dimensional and categorical approaches to understanding dissociation in the eating disorders.

OBJECTIVE: The present study compared levels of dissociation across groups of eating-disordered women, investigating the utility of dimensional and categorical measures of dissociation in understanding diagnoses and behaviours in the eating disorders. METHODS: The Dissociative Experiences Scale (DES-II) was completed by 170 eating-disordered women (drawn from out-patient assessment clinics) and 203 nonclinical women. The clinical group also supplied information regarding eating behaviours and related features (alcohol abuse, reported history of sexual abuse). The DES-II and a subset of its items (DES-Taxon) were used as dimensional and categorical discriminators of the groups and of the presence/absence of specific features and symptoms. RESULTS: When treated as dimensional measures, the DES-II and DES-Taxon had similar levels of clinical utility (particularly discriminating the binge-purge anorexics from the other clinical groups). However, the DES-Taxon was a superior categorical measure, discriminating groups more clearly and predicting the presence of many symptoms and features much more powerfully. CONCLUSIONS: The DES-Taxon is a potentially valuable self-report measure for indicating the level and presence of dissociative psychopathology in the eating disorders. As well as being convenient to administer and score, it has the clinical and research value of indicating those patients in whom treatment might need to include addressing pathological dissociation.