Heat shock protein 70 binds to human apurinic/apyrimidinic endonuclease and stimulates endonuclease activity at abasic sites.

The interaction of human heat shock protein 70 (HSP70) with human apurinic/apyrimidinic endonuclease (HAP1) was demonstrated by coimmunoprecipitation. A combination of HSP70 and HAP1 also caused a shift in the electrophoretic mobility of a DNA fragment containing an apurinic/apyrimidinic site. The functional consequence of the HSP70/HAP1 interaction was a 10-100-fold enhancement of endonuclease activity at abasic sites. The physical and functional interaction between HSP70 and HAP1 did not require the addition of ATP. The association of HSP70 and a key base excision repair enzyme suggests a role for heat shock proteins in promoting base excision repair. These findings provide a possible mechanism by which HSP70 protects cells against oxidative stress.

Dietary intake of whole grains.

OBJECTIVE: The objective of this study was to provide national estimates of whole-grain intake in the United States, identify major dietary sources of whole grains and compare food and nutrient intakes of whole-grain consumers and nonconsumers. METHODS: Data were collected from 9,323 individuals age 20 years and older in USDA's 1994-96 Continuing Survey of Food Intakes by Individuals through in-person interviews on two non-consecutive days using a multiple-pass 24-hour recall method. Foods reported by respondents were quantified in servings as defined by the Food Guide Pyramid using a new database developed by the USDA. Whole-grain and nonwhole-grain servings were determined based on the proportion, by weight, of the grain ingredients in each food that were whole grain and nonwhole grain. Sampling weights were applied to provide national probability estimates adjusted for differential rates of selection and nonresponse. Then, t tests were used to assess statistically significant differences in intakes of nutrients and food groups by whole-grain consumers and nonconsumers. RESULTS: According to the 1994-96 survey, U.S. adults consumed an average of 6.7 servings of grain products per day; 1.0 serving was whole grain. Thirty-six percent averaged less than one whole-grain serving per day based on two days of intake data, and only eight percent met the recommendation to eat at least three servings per day. Yeast breads and breakfast cereals each provided almost one-third of the whole-grain servings, grain-based snacks provided about one-fifth, and less than one-tenth came from quick breads, pasta, rice, cakes, cookies, pies, pastries and miscellaneous grains. Whole-grain consumers had significantly better nutrient profiles than nonconsumers, including higher intakes of vitamins and minerals as percentages of 1989 Recommended Dietary Allowances and as nutrients per 1,000 kilocalories, and lower intakes of total fat, saturated fat and added sugars as percentages of food energy. Consumers were significantly more likely than nonconsumers to meet Pyramid recommendations for the grain, fruit and dairy food groups. CONCLUSION: Consumption of whole-grain foods by U.S. adults falls well below the recommended level. A large proportion of the population could benefit from eating more whole grain, and efforts are needed to encourage consumption.

Association of organic solvent tolerance and fluoroquinolone resistance in clinical isolates of Escherichia coli.

Fluoroquinolone resistance in Escherichia coli is principally caused by two kinds of mutation: those affecting the target proteins of the drugs, i.e. DNA gyrase and topoisomerase IV, and those affecting regulatory genes such as marA, soxS or robA. Recently, overexpression of the latter genes was linked to increased organic solvent tolerance in E. coli. Among 138 clinical fluoroquinolone-resistant and -susceptible clinical isolates of E. coli we found a high association between fluoroquinolone resistance and organic solvent tolerance. This finding suggests that E. coli may undergo an adaptive response to extrinsic substances other than quinolones, while mutating to fluoroquinolone resistance.

Role of the acrAB locus in organic solvent tolerance mediated by expression of marA, soxS, or robA in Escherichia coli.

Escherichia coli K-12 strains are normally tolerant to n-hexane and susceptible to cyclohexane. Constitutive expression of marA of the multiple antibiotic resistance (mar) locus or of the soxS or robA gene product produced tolerance to cyclohexane. Inactivation of the mar locus or the robA locus, but not the soxRS locus, increased organic solvent susceptibility in the wild type and Mar mutants (to both n-hexane and cyclohexane). The organic solvent hypersusceptibility is a newly described phenotype for a robA-inactivated strain. Multicopy expression of mar, soxS, or robA induced cyclohexane tolerance in strains with a deleted or inactivated chromosomal mar, soxRS, or robA locus; thus, each transcriptional activator acts independently of the others. However, in a strain with 39 kb of chromosomal DNA, including the mar locus, deleted, only the multicopy complete mar locus, consisting of its two operons, produced cyclohexane tolerance. Deletion of acrAB from either wild-type E. coli K-12 or a Mar mutant resulted in loss of tolerance to both n-hexane and cyclohexane. Organic solvent tolerance mediated by mar, soxS, or robA was not restored in strains with acrAB deleted. These findings strongly suggest that active efflux specified by the acrAB locus is linked to intrinsic organic solvent tolerance and to tolerance mediated by the marA, soxS, or robA gene product in E. coli.

The prevalence and nature of child sexual abuse in Queensland, Australia.

Child sexual abuse is a problem of considerable proportion in the USA and Europe (Finkelhor, 1994). However, there are very little data available on child sexual abuse in Australia apart from the first ground-breaking study by Goldman and Goldman (1988a) undertaken in Victoria. No Australian National or State statistics are available. Apart from anecdotal evidence from fragmented sources, the prevalence and nature of child sexual abuse in Queensland have not been researched. Queensland is considered one of the most politically and socially conservative states in Australia, has a hotter climate, and is less developed than other Australian states. Just as the USA has its Deep South. Queensland is similarly referred to as the "Deep North."

Selective serotonin reuptake inhibitor treatment of depression in symptomatic HIV infection and AIDS. Improvements in affective and somatic symptoms.

Somatic symptoms often complicate the diagnosis and psychopharmacological treatment of depression in HIV illness. We treated 33 depressed HIV-positive men and women with medically symptomatic HIV or AIDS (CDC stages 2B, 2C, 3B, or 3C) in a 6 week open-label trial with sertraline, paroxetine, or fluoxetine, to assess their effectiveness and tolerability. We further assessed whether treatment of depression resulted in a reduction in both affective and somatic symptoms in this medically ill population. Twenty-four subjects (73%) completed the trial (7 on sertraline, 7 on paroxetine, 10 on fluoxetine), 20 (83%) of whom were clinical responders. Nine dropped out within 1-3 weeks of treatment because of adverse effects, mostly agitation, anxiety, and insomnia. Subjects who completed 6 weeks of SSRI treatment experienced significant reductions in both affective and somatic symptoms, many of the latter having been attributed to HIV rather than depression. These results suggest that, even in later stages of HIV illness, the contribution of depression to perceived somatic symptoms may be significant, and that these symptoms may improve with antidepressant treatment.

Multiple antibiotic resistance (mar) locus protects Escherichia coli from rapid cell killing by fluoroquinolones.

The multiple antibiotic resistance (mar) locus in Escherichia coli consists of two divergently expressed operons (marC and marRAB), both of which contribute to the Mar phenotype. Overexpression of the marRAB operon protected E. coli against rapid cell killing by fluoroquinolones. Inactivation of the operon in mar mutants restored a wild-type bactericidal susceptibility. Both operons of the locus were required for protection from the quinolone-mediated bactericidal activity in mar locus deletion mutants. The effect was lost at high concentrations of fluoroquinolones, unlike the case for the previously described genes hipA and hipQ. The inducible mar locus appears to specify a novel antibactericidal mechanism which may play a role in the emergence of fluoroquinolone-resistant clinical E. coli isolates.

An elective seminar to teach first-year students the social and medical aspects of AIDS.

First-year students at a midwestern medical school are introduced to a comprehensive approach to the biological, psychological, and social aspects of acquired immune deficiency syndrome (AIDS). In a seven-week elective seminar (approximately 12 hours in length), the students view a television movie and a documentary film about persons with AIDS and their families and friends, and they participate in roundtable discussions with AIDS patients, volunteers who coordinate support and advocacy for persons with AIDS, and health care professionals involved in the care of AIDS patients. They receive reading materials and lectures on the pathology, epidemiology, and history of AIDS, and they monitor and discuss radio and television reporting on AIDS. In wrap-up sessions and evaluation questionnaires, the students have reported the seminar to be valuable in helping them overcome their fear of the disease, develop empathy for patients with catastrophic diseases, and understand a comprehensive approach to a complex disease.