Transcript decay mediated by RNase III in Borrelia burgdorferi

The causative agent of Lyme disease, Borrelia burgdorferi, requires shifts in gene expression to undergo its natural enzootic cycle between tick and vertebrate hosts. mRNA decay mechanisms play significant roles in governing gene expression in other bacteria, but are not yet characterized in B. burgdorferi. RNase III is an important enzyme in processing ribosomal RNA, but it also plays a role in mRNA decay in many bacteria. We compared RNA decay profiles and steady-state abundances of transcripts in wild-type Borrelia burgdorferi strain B31 and in an RNase III null (rnc^-) mutant. Transcripts encoding RNA polymerase subunits (rpoA and rpoS), ribosomal proteins (rpsD, rpsK, rpsM, rplQ, and rpsO), a nuclease (pnp), a flagellar protein (flaB), and a translational regulator (bpuR) decayed more rapidly in the wild-type strain than in the slow growing rnc^- mutant indicating that RNA turnover is mediated by RNase III in the bacterium that causes Lyme disease. Additionally, in wild type bacteria, RNA decay rates of rpoS, rpoN, ospA, ospC, bpuR and dbpA transcripts are only modestly affected by changes in the osmolarity.

Classification of eating disturbance in children and adolescents: proposed changes for the DSM-V

Childhood and adolescence are critical periods of neural development and physical growth. The malnutrition and related medical complications resulting from eating disorders such as anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified may have more severe and potentially more protracted consequences during youth than during other age periods. The consensus opinion of an international workgroup of experts on the diagnosis and treatment of child and adolescent eating disorders is that (a) lower and more developmentally sensitive thresholds of symptom severity (e.g. lower frequency of purging behaviours, significant deviations from growth curves as indicators of clinical severity) be used as diagnostic boundaries for children and adolescents, (b) behavioural indicators of psychological features of eating disorders be considered even in the absence of direct self-report of such symptoms and (c) multiple informants (e.g. parents) be used to ascertain symptom profiles. Collectively, these recommendations will permit earlier identification and intervention to prevent the exacerbation of eating disorder symptoms.

Classification of child and adolescent eating disturbances. Workgroup for Classification of Eating Disorders in Children and Adolescents (WCEDCA)

OBJECTIVE

: The purpose of this article is to summarize major conceptual and clinical variables related to age-appropriate and developmentally appropriate classification of eating problems and disorders in children and adolescents.

METHOD

A review of current classifications and related literature in child development is provided. Problems with current classification schemes are identified and discussed.

RESULTS

Current classifications are inadequate to address the clinical and research needs of children and adolescents with eating disturbances and disorders.

CONCLUSION

A range of possible changes in classification strategies for eating disorders in children and adolescents are described.

A comparison of male and female adolescents referred to an eating disorder program

OBJECTIVE

To compare gender-related psychopathology and psychiatric diagnoses in male and female adolescents referred to an adolescent eating disorder program.

METHOD

All adolescents presenting at the Eating Disorder Program at our hospital completed the semistructured Diagnostic Interview for Children and Adolescents-Revised (DICA-R) and self-report scales, including the Children's Depression Inventory (CDI), the Brief Symptom Inventory (BSI), the Eating Disorder Inventory (EDI-2), and the Family Assessment Measure (FAM-III), during their initial assessment. The 157 subjects (21 male, 136 female) were classified into Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) eating disorder (ED) subtypes and then recombined into male and female restricters (R) and ED-related groups: showing eating-related concerns but not having a DSM-IV diagnosis. We compared the male and female restricter groups and ED-related group on 5 specific psychological dimensions to examine comorbid psychiatric diagnosis, ED-specific and nonspecific psychopathology, EDI clinical and provisional subscales, and family functioning using multivariate analyses of covariance (MANCOVAs).

RESULTS

Males endorsed statistically significant lower drive for thinness and body dissatisfaction than did females. However, there are no representative norms for adolescent males on these variables. The ED-related group also endorsed statistically significant lower drive for thinness and body dissatisfaction (specific ED psychopathology) than did the ED-restricter groups. The males in both groups endorsed fewer EDI items than did their female counterparts, but the differences were not statistically significant. Comorbid psychiatric diagnoses of depression and anxiety in male and female restricters were common but did not distinguish the groups.

CONCLUSIONS

Our results suggest that male and female adolescents with EDs are clinically similar to each other and therefore resemble adults for lack of gender-specific effects on self-reported psychopathology, family functioning, and comorbid psychiatric disorders.

Decreased bone density in adolescent girls with anorexia nervosa

Osteoporosis develops in women with chronic anorexia nervosa. To determine whether bone mass is reduced in younger patients as well, bone density was studied in a group of adolescent patients with anorexia nervosa. With single- and dual-photon absorptiometry, a comparison was made of bone mineral density of midradius, lumbar spine, and whole body in 18 girls (12 to 20 years of age) with anorexia nervosa and 25 healthy control subjects of comparable age. Patients had significantly lower lumbar vertebral bone density than did control subjects (0.830 +/- 0.140 vs 1.054 +/- 0.139 g/cm2) and significantly lower whole body bone mass (0.700 +/- 0.130 vs 0.955 +/- 0.130 g/cm2). Midradius bone density was not significantly reduced. Of 18 patients, 12 had bone density greater than 2 standard deviations less than normal values for age. The diagnosis of anorexia nervosa had been made less than 1 year earlier for half of these girls. Body mass index correlated significantly with bone mass in girls who were not anorexic (P less than .05, .005, and .0001 for lumbar, radius, and whole body, respectively). Bone mineral correlated significantly with body mass index in patients with anorexia nervosa as well. In addition, age at onset and duration of anorexia nervosa, but not calcium intake, activity level, or duration of amenorrhea correlated significantly with bone mineral density. It was concluded that important deficits of bone mass occur as a frequent and often early complication of anorexia nervosa in adolescence. Whole body is considerably more sensitive than midradius bone density as a measure of cortical bone loss in this illness.(ABSTRACT TRUNCATED AT 250 WORDS)