Bromination of deoxycytidine by eosinophil peroxidase: a mechanism for mutagenesis by oxidative damage of nucleotide precursors

Oxidants generated by eosinophils during chronic inflammation may lead to mutagenesis in adjacent epithelial cells. Eosinophil peroxidase, a heme enzyme released by eosinophils, generates hypobromous acid that damages tissue in inflammatory conditions. We show that human eosinophils use eosinophil peroxidase to produce 5-bromodeoxycytidine. Flow cytometric, immunohistochemical, and mass spectrometric analyses all demonstrated that 5-bromodeoxycytidine generated by eosinophil peroxidase was taken up by cultured cells and incorporated into genomic DNA as 5-bromodeoxyuridine. Although previous studies have focused on oxidation of chromosomal DNA, our observations suggest another mechanism for oxidative damage of DNA. In this scenario, peroxidase-catalyzed halogenation of nucleotide precursors yields products that subsequently can be incorporated into DNA. Because the thymine analog 5-BrUra mispairs with guanine in DNA, generation of brominated pyrimidines by eosinophils might constitute a mechanism for cytotoxicity and mutagenesis at sites of inflammation.

Lead and mercury mutagenesis: type of mutation dependent upon metal concentration

Lead and mercury are toxic metals that are widely distributed in the atmosphere, soil, and groundwater. It is estimated that 2-4 x 10(4) tons of these metals are released annually into the environment by natural and industrial processes. Therefore, human exposure to low relatively nontoxic concentrations of these metals is unavoidable. However, the possible health effects of such exposure remain controversial. We have previously reported that low, subthreshold concentrations (0.1-1 microM) of these metals are mutagenic in the transgenic Chinese hamster ovary cell line AS52. The purpose of the present study is to determine the types of mutations induced in the gpt gene in AS52 cells. Using multiplex polymerase chain reaction and southern blot analyses, we characterized the 138 lead-induced, 192 mercury-induced, 29 reactive oxygen radical-induced, and 20 spontaneously arising mutants for point and deletion mutations in the gpt gene. Similar levels of point mutations were observed in the lead- and mercury-induced populations (47.8 and 53.6, respectively), which was significantly less than that occurring in the spontaneously arising and reactive oxygen intermediate-induced mutants. However, further examination of the data revealed that at concentrations of the metals of equal to or less than 0.4 microM, the majority of the mutations in the gpt gene were point mutations, while at higher concentrations, deletions (partial and complete) were the predominant type of mutation. These results are consistent with the hypothesis that lead and mercury induce mutations in eukaryotic cells by at least two distinct mechanisms.

Confidence of academic general internists and family physicians to teach ambulatory procedures

OBJECTIVE

To evaluate and compare the readiness of academic general internal medicine physicians and academic family medicine physicians to perform and teach 13 common ambulatory procedures.

DESIGN

Mailed survey.

SETTING

Internal medicine and family medicine residency training programs associated with 35 medical schools in 9 eastern states.

PARTICIPANTS

Convenience sample of full-time teaching faculty.

MEASUREMENTS AND MAIN RESULTS

A total of 331 general internists and 271 family physicians returned completed questionnaires, with response rates of 57% and 65%, respectively. Academic generalists ranked most of the ambulatory procedures as important for primary care physicians to perform; however, they infrequently performed or taught many of the procedures. Overall, compared with family physicians, general internists performed and taught fewer procedures, received less training, and were less confident in their ability to teach these procedures. Physicians' confidence to teach a procedure was strongly associated with training to perform the procedure and performing or precepting a procedure at least 10 times per year.

CONCLUSIONS

Many academic general internists do not perform or precept common adult ambulatory procedures. To ensure that residents have the opportunity to learn routine ambulatory procedures, training programs may need to recruit qualified faculty, train current faculty, or arrange for academic specialists or community physicians to teach these skills.

Experience of discordant beta hCG results by different assays in the management of non-seminomatous germ cell tumours of the testis

Fifty-five patients with non-seminomatous germ cell tumours (NSGCT) who were referred to a regional clinical oncology centre over a 3-year period were assessed prospectively with assays of the serum tumour markers alpha-feto protein (AFP) and beta-human chorionic gonadotropin (beta hCG). Paired baseline beta hCG assays were undertaken using a polyclonal radioimmunoassay (RIA) and a monoclonal fluoroimmunoassay (FIA). Serial paired measurements were undertaken in patients showing discordance on baseline assays. Four patients (7%; 95% confidence interval 0-14) showed discordance between the paired beta hCG assays. Of these, two showed elevated beta hCG on RIA, with normal levels on FIA; two showed elevated beta hCG on FIA, with normal levels on RIA. No discordance was noted with AFP assays. Discordance persisted in two of the patients (50%) and disappeared on treatment in one (25%); one patient died during treatment. Discordant beta hCG assays present difficulties in interpretation and have therapeutic implications in patients with NSGCT. No single currently available assay is conclusive in all patients and commercial assay kits should be chosen with care.

The relation between stress fractures and bone mineral density: evidence from active-duty Army women

OBJECTIVE

To determine if bone mineral density (BMD) is associated with the probability of stress fractures in premenopausal women.

DESIGN

Case-control study.

SETTING

Large Army post, Fort Lewis, WA.

PARTICIPANTS

Twenty-seven active duty Army women with documented stress fractures within the last 2 years and 158 female controls.

METHODS AND MAIN RESULTS

All subjects were examined and interviewed. BMD of the femoral neck and posteroanterior lumbar spine (L2-L4) was measured using dual energy X-ray absorptiometry. Univariate comparisons revealed no significant differences in BMD of the femoral neck or lumbar spine between groups. Women with stress fractures had a significantly higher exercise intensity (428 vs 292 minutes per week, p<.05) and were more likely to be entry-level enlisted soldiers (63% vs. 44%, p<.05) than those without stress fractures. Multivariate analyses revealed a strong negative association between femoral neck BMD and the probability of stress fractures (lower BMD, higher risk). Exercise intensity and body mass index had a significant positive effect on BMD of the femoral neck and lumbar spine, yet both were associated with an increased probability of stress fractures.

CONCLUSIONS

Femoral neck BMD was significantly associated with the probability of stress fractures. Optimal training programs should balance the beneficial indirect effect of increased exercise (through increased BMD) with its detrimental direct effect on stress fractures.

Abnormal eating behaviors in military women

PURPOSE

The purpose of this study was to evaluate the prevalence of abnormal eating behaviors in women on active duty in the Army.

METHODS

A total of 423 female soldiers from the general population on active duty volunteered to participate in this study. They completed the Eating Disorder Inventory (EDI) questionnaire. Each questionnaire was screened and any woman on active duty practicing abnormal eating behaviors (criteria set up by the authors) underwent an interview. A diagnosis, using DSM IV criteria, of one of the following was determined from the interview: 1) No eating disorder, (2) Anorexia nervosa, 3) Bulimia nervosa, 4) binge eating disorder, 5a) Eating disorder NOS, and 5b) Situational eating disorder. A situational eating disorder was defined as any abnormal eating behaviors consistent with an eating disorder NOS that was practiced intermittently and in response to external pressures associated with significant distress, such as military weigh-ins or army physical fitness testing (APFT).

RESULTS

Of the 423 women on active duty who participated, 33.6% (N = 142) met the questionnaire screening criteria for being "at risk" for abnormal eating behaviors and underwent an interview. Of the 142 women interviewed, 33 (8%) women were diagnosed with an eating disorder. The women with eating disorders exercised, felt dissatisfied with their weight, and felt significantly more pressure about their weight than the women without eating disorders. In addition, they also had significantly greater scores on the Drive for Thinness (DT), Bulemia (B), and Body Dissatisfaction (BD) subscales, and the total EDI scores for both the 8 and 11 subscales.

CONCLUSION

In the women on active duty in the Army studied, there was an 8% prevalence of eating disorders.

Development of a brief test to measure functional health literacy

We describe the development of an abbreviated version of the Test of Functional Health Literacy in Adults (TOFHLA) to measure patients' ability to read and understand health-related materials. The TOFHLA was reduced from 17 Numeracy items and 3 prose passages to 4 Numeracy items and 2 prose passages (S-TOFHLA). The maximum time for administration was reduced from 22 minutes to 12. In a group of 211 patients given the S-TOFHLA, Cronbach's alpha was 0.68 for the 4 Numeracy items and 0.97 for the 36 items in the 2 prose passages. The correlation (Spearman) between the S-TOFHLA and the Rapid Estimate of Adult Literacy in Medicine (REALM) was 0.80, although there were important disagreements between the two tests. The S-TOFHLA is a practical measure of functional health literacy with good reliability and validity that can be used by health educators to identify individuals who require special assistance to achieve learning goals.

The female athlete triad: prevalence in military women

The objective of this study was to define the prevalence of the female athlete triad, i.e., the simultaneous occurrence of disordered eating, amenorrhea, and osteoporosis, in military women. A total of 423 active duty female soldiers participated in a three-part prospective, cross-sectional study. Part 1 entailed completing the Eating Disorder Inventory and a clinical interview with those women "at risk" for an eating disorder. Part 2 consisted of a clinical evaluation and laboratory studies of any woman with menstrual irregularities. Part 3 evaluated the bone mineral density of all women meeting the inclusion criteria for parts 1 and 2 using dual-energy X-ray absorptiometry. Of the 423 active duty women who participated in the study, no subject exhibited the full female athlete triad. Thirty-three women (8%) had an eating disorder and 109 women (26%) were at risk for an eating disorder. Our results suggest that the female athlete triad is not a clinically significant problem for the Army.

Attitudes and beliefs of African Americans toward participation in medical research

OBJECTIVE

To describe barriers to participation of African Americans in research.

DESIGN

Focus group interviews conducted in 1997.

PATIENTS

Thirty-three African-American adults presenting to an urban public hospital for outpatient medical care participated in one of five focus groups.

MEASUREMENTS AND MAIN RESULTS

African-American patients' attitudes toward medical research were measured. Mistrust of doctors, scientists, and the government was reported consistently by the participants. Many participants described concerns about the ethical conduct of clinicians and investigators when poor or minority patients are involved and cited examples of exploitation as supporting evidence for their mistrust of the medical establishment. While participants were clear about the violation of human rights in the Tuskegee Syphilis Study, all were misinformed of the historical facts of the study. Few participants understood the concept of informed consent. Participants saw signing the document as relinquishing their autonomy and as a legal protection for physicians. Despite these concerns, participants gave recommendations to improve minority participation in research.

CONCLUSIONS

African-American participants in this study described distrust of the medical community as a prominent barrier to participation in clinical research. Participants described real and perceived examples of exploitation to support their distrust of researchers. The goal of the consent process, to inform patients of risks and benefits so as to facilitate self-determination, was misinterpreted by these participants. Understanding the importance of interpersonal trust within the clinical relationship may prove to be a significant factor in enhancing participation in clinical trials.

Prognostic factors in patients progressing after cisplatin-based chemotherapy for malignant non-seminomatous germ cell tumours

The aim of this study was to define prognostic parameters for survival in patients with malignant germ cell tumours progressing after platinum-based induction chemotherapy with or without surgery. A total of 164 progressing patients (testicular: 83%, extragonadal: 17%) were identified out of 795 patients treated with platinum-based induction chemotherapy for metastatic germ cell malignancy with or without surgery. 'Progressive disease' included patients who had progressed after a previous partial or complete remission as well as patients who failed primary therapy. Salvage chemotherapy consisted of 'conventional' platinum-based chemotherapy. Prognostic factors for survival were assessed by uni- and multivariate analyses. The resulting prognostic model was validated in an independent data set of 66 similar patients. For all 164 patients the median time from start of induction chemotherapy to progression was 10 months (range: 0-99). Thirty-eight (23%) patients relapsed after 2 years. The 5-year survival rate for all progressing patients was 30% (95% confidence interval 23-38%). In the univariate analysis the following factors most importantly predicted a poor prognosis: progression-free interval < 2 years: initial poor prognosis category (MRC criteria), < CR to induction chemotherapy, initial treatment early in the 1980s and treatment given at a 'small' centre. Three prognostic factors remained in the multivariate analysis: progression-free interval, response to induction treatment and the level of serum human chronic gonadotrophin (hCG) and alpha fetoprotein (AFP) at relapse. One hundred and twenty-four patients could be classified on the basis of these characteristics, Those patients with progression-free interval < 2 years, < CR to induction chemotherapy and high markers at relapse (AFP >100 kU l(-1) or hCG >100 IU l(-1)) formed a poor prognosis group of 30 patients, none of whom survived after 3 years. Patients with at most two of these three risk factors formed a good prognosis group of 94 patients (76%) with a 47% (37-56%) 5-year survival. Thirty-eight patients from the good prognosis group with a progression-free interval of >2 years had a 2-year survival of 74% (60-88%) and 5-year survival of 61%. These prognostic groups were validated in the independent data set, in which 5-year survival rates in the good and poor risk groups were 51% and 0% respectively. One-third of patients progressing during or after platinum-based induction chemotherapy for metastatic germ cell malignancy may be cured by repeated 'conventional' platinum-based chemotherapy. Good prognosis parameters are: progression-free interval of > 2 years, CR to induction treatment and normal or low serum markers at relapse (hCG < 100 IU l(-1) and AFP < 100 kU l(-1)). The results of high-dose salvage chemotherapy should be interpreted on the background of these prognostic factors.

Post-obstruction rat sperm autoantigens identified by two-dimensional gel electrophoresis and western blotting

Although antisperm autoantibody responses to obstruction of the male reproductive system have been documented, information on the nature of the cognate sperm autoantigens has been limited. In the present study, the patterns of sperm autoantigens recognized by sera from rats after obstruction of the vas deferens or epididymis were studied by high resolution two-dimensional (2-D) gel electrophoresis and western blotting. Comparisons of patterns of autoantigens stained on 2-D western blots of sera from prepubertal vasectomy, prepubertal epididymal ligation and adult vasectomy groups revealed both similarities and differences. Sera from sham-operated animals showed no detectable reaction or much lighter staining of a small number of spots. Visualization of sperm autoantigens on 2-D western blots supported the hypothesis that there is a relatively small set of sperm proteins that can be regarded as dominant post-obstruction sperm autoantigens because they are recognized by multiple post-obstruction sera. The 2-D analysis revealed previously undetected distinctions in the autoantigens recognized after adult and prepubertal vasectomy, as well as variations with the site of obstruction. These differences in the response may be due in part to changes in antigens of spermatozoa in different parts of the tract and at different ages, as well as variations in exposure of sperm cell proteins to the immune system resulting from the sites of spermatic granulomas. Preparative 2-D gels and western blotting with post-obstruction sera are now being used to identify specific sperm autoantigens by microsequencing of selected proteins.

Health literacy among Medicare enrollees in a managed care organization

CONTEXT

Elderly patients may have limited ability to read and comprehend medical information pertinent to their health.

OBJECTIVE

To determine the prevalence of low functional health literacy among community-dwelling Medicare enrollees in a national managed care organization.

DESIGN

Cross-sectional survey.

SETTING

Four Prudential HealthCare plans (Cleveland, Ohio; Houston, Tex; south Florida; Tampa, Fla).

PARTICIPANTS

A total of 3260 new Medicare enrollees aged 65 years or older were interviewed in person between June and December 1997 (853 in Cleveland, 498 in Houston, 975 in south Florida, 934 in Tampa); 2956 spoke English and 304 spoke Spanish as their native language. MAIN OUTCOME MEASURE; Functional health literacy as measured by the Short Test of Functional Health Literacy in Adults.

RESULTS

Overall, 33.9% of English-speaking and 53.9% of Spanish-speaking respondents had inadequate or marginal health literacy. The prevalence of inadequate or marginal functional health literacy among English speakers ranged from 26.8% to 44.0%. In multivariate analysis, study location, race/language, age, years of school completed, occupation, and cognitive impairment were significantly associated with inadequate or marginal literacy. Reading ability declined dramatically with age, even after adjusting for years of school completed and cognitive impairment. The adjusted odds ratio for having inadequate or marginal health literacy was 8.62 (95% confidence interval, 5.55-13.38) for enrollees aged 85 years or older compared with individuals aged 65 to 69 years.

CONCLUSIONS

Elderly managed care enrollees may not have the literacy skills necessary to function adequately in the health care environment. Low health literacy may impair elderly patients' understanding of health messages and limit their ability to care for their medical problems.

Lack of a regular source of care among children using a public hospital emergency department

OBJECTIVES

This study examined risk factors for not having a regular source of care among children presenting to an urban public hospital for nonappointment care. Lack of a regular source of care is associated with decreased use of appropriate health care services and preventive care among children.

METHODS

A cross-sectional survey was conducted for all children less than 16 years of age attending an emergency department at an urban public hospital over a consecutive 7-day period. Univariate and multivariate logistic regression analyses were conducted.

RESULTS

In 791 interviews available for analysis, 52% of preschool children and 66% of school-aged children did not have a regular source of care. Children without a regular source of care were more likely to present for nonurgent conditions (P < 0.0005). In multivariate analysis, older age of the child (OR = 1.6, 95% CI 1.132.25), lack of insurance (OR = 1.47, 95% CI 1.03-2.11), and lack of personal vehicle (OR = 1.44, 95% CI 1.05-1.97) were associated with not having a regular source of care.

CONCLUSIONS

The majority of children using an urban emergency department were without a regular source of care. In this population, no single factor identified children without a regular source of care, but increased age and lack of insurance were associated with it. Addressing this situation will require a multifaceted approach that includes, but is not limited to, decreasing financial barriers.

Ascorbic acid-dehydroascorbate induces cell cycle arrest at G2/M DNA damage checkpoint during oxidative stress

Reactive oxygen species induce cellular damage and have been implicated as mediators for cellular signaling pathways. However, a linkage between the cellular redox status and cell cycle progression has not been demonstrated. We previously demonstrated, using the Chinese hamster ovary cell line AS52, that the cytotoxic and mutagenic effects of oxidative stress is prevented by ascorbic acid (AA), but only when cells are treated with AA prior to treatment with the stressor. To elucidate the mechanism(s) responsible for this effect, we determined the effect of AA on cell cycle progression during oxidative stress. Flow cytometric analyses demonstrated that treatment of AS52 cells with AA (50 microM), prior to treatment with a radical generating system (RGS), enhanced cell cycle arrest at the G2/M DNA damage checkpoint when compared to cells treated with RGS. AA had no effect on cell cycle progression in the absence of oxidative stress. Furthermore, under conditions that prevent the reduction of dehydroascorbate (DHA), the oxidized form of AA, cell cycle arrest was also induced at the G2/M DNA damage checkpoint. These observations demonstrate that during periods of oxidative stress, AA functions as an antioxidant and DHA enhances transient arrest at the G2/M checkpoint by delaying the activation of cyclin B-cdc2. These results suggest the presence of a unique redox mechanism for the regulation of cell cycle progression and also demonstrate a novel mechanism by which AA protects cells from damage due to oxidative stress.

Health literacy and the risk of hospital admission

OBJECTIVE

To determine the association between patient literacy and hospitalization.

DESIGN

Prospective cohort study.

SETTING

Urban public hospital.

PATIENTS

A total of 979 emergency department patients who participated in the Literacy in Health Care study and had completed an intake interview and literacy testing with the Test of Functional Health Literacy in Adults were eligible for this study. Of these, 958 (97.8%) had an electronic medical record available for 1994 and 1995.

MEASUREMENTS AND MAIN RESULTS

Hospital admissions to Grady Memorial Hospital during 1994 and 1995 were determined by the hospital information system. We used multivariate logistic regression to determine the independent association between inadequate functional health literacy and hospital admission. Patients with inadequate literacy were twice as likely as patients with adequate literacy to be hospitalized during 1994 and 1995 (31. 5% vs 14.9%, p <.001). After adjusting for age, gender, race, self-reported health, socioeconomic status, and health insurance, patients with inadequate literacy were more likely to be hospitalized than patients with adequate literacy (adjusted odds ratio [OR] 1.69; 95% confidence interval [CI] 1.13, 2.53). The association between inadequate literacy and hospital admission was strongest among patients who had been hospitalized in the year before study entry (OR 3.15; 95% CI 1.45, 6.85).

CONCLUSIONS

In this study population, patients with inadequate functional health literacy had an increased risk of hospital admission.

Inadequate literacy is a barrier to asthma knowledge and self-care

STUDY OBJECTIVES

To determine the relationship of literacy to asthma knowledge and ability to use a metered-dose inhaler (MDI) among patients with asthma.

DESIGN

Cross-sectional survey.

SETTING

Emergency department and asthma clinic at an urban public hospital.

PATIENTS

Convenience sample of 273 patients presenting to the emergency department for an asthma exacerbation and 210 patients presenting to a specialized asthma clinic for routine care.

INTERVENTIONS

Measurement of literacy with the Rapid Estimate of Adult Literacy in Medicine, asthma knowledge (20 question oral test), and demonstration of MDI technique (six-item assessment).

MEASUREMENTS AND RESULTS

Only 27% of patients read at the high-school level, although two thirds reported being high-school graduates; 33% read at the seventh- to eighth-grade level, 27% at the fourth- to sixth-grade level, and 13% at or below the third-grade level. Mean asthma knowledge scores (+/-SD) were directly related to reading levels: 15.1+/-2.5, 13.9+/-2.5, 13.4+/-2.8, 11.9+/-2.5, respectively (p < 0.01). Patient reading level was the strongest predictor of asthma knowledge score in multivariate analysis. Poor MDI technique (< or =3 correct steps) was found in 89% of patients reading at less than the third-grade level compared with 48% of patients reading at the high-school level. In multivariate regression analyses, reading level was the strongest predictor of MDI technique.

CONCLUSIONS

Inadequate literacy was common and strongly correlated with poorer knowledge of asthma and improper MDI use.

Practical assessment of adult literacy in health care

Low literacy is a pervasive and underrecognized problem in health care Approximately 21% of American adults are functionally illiterate, and another 27% have marginal literacy skills. Such patients may have difficulty reading and understanding discharge instructions, medication labels, patient education materials, consent forms, or health surveys. Properly assessing the literacy level of individual patients or groups may avoid problems in clinical care and research. This article reviews the use of literacy assessments, discusses their application in a variety of health care settings, and cites issues providers need to consider before testing. The authors describe informal and formal methods of screening for reading and comprehension in English and Spanish including the Rapid Estimate of Adult Literacy in Medicine, the Wide Range Achievement Test-3, the Cloze procedure, the Test of Functional Health Literacy in Adults, and others. Practical implications and recommendations for specific use are made.

Ambulatory health care use by patients in a public hospital emergency department

OBJECTIVE

To describe primary care clinic use and emergency department (ED) use for a cohort of public hospital patients seen in the ED, identify predictors of frequent ED use, and ascertain the clinical diagnoses of those with high rates of ED use.

DESIGN

Cohort observational study.

SETTING

A public hospital in Atlanta, Georgia.

PATIENTS

Random sample of 351 adults initially surveyed in the ED in May 1992 and followed for 2 years.

MEASUREMENTS AND MAIN RESULTS

Of the 351 patients from the initial survey, 319 (91%) had at least one ambulatory visit in the public hospital system during the following 2 years and one third of the cohort was hospitalized. The median number of subsequent ED visits was 2 (mean 6.4), while the median number of visits to a primary care appointment clinic was O (mean 1.1) with only 90 (26%) of the patients having any primary care clinic visits. The 58 patients (16.6%) who had more than 10 subsequent ED visits accounted for 65.6% of all subsequent ED visits. Overall, patients received 55% of their subsequent ambulatory care in the ED, with only 7.5% in a primary care clinic. In multivariate regression, only access to a telephone (odds ratio [OR] 0.48; 95% confidence interval [CI] 0.39, 0.60), hospital admission (OR 5.90; 95% CI 4.01, 8.76), and primary care visits (OR 1.68; 95% CI 1.34, 2.12) were associated with higher ED visit rates. Regular source of care, insurance coverage, and health status were not associated with ED use. From clinical record review, 74.1% of those with high rates of use had multiple chronic medical conditions, or a chronic medical condition complicated by a psychiatric diagnosis, or substance abuse.

CONCLUSIONS

All subgroups of patients in this study relied heavily on the ED for ambulatory care, and high ED use was positively correlated with appointment clinic visits and inpatient hospitalization rates, suggesting that high resource utilization was related to a higher burden of illness among those patients. The prevalence of chronic medical conditions and substance abuse among these most frequent emergency department users points to a need for comprehensive primary care. Multidisciplinary case management strategies to identify frequent ED users and facilitate their use of alternative care sites will be particularly important as managed care strategies are applied to indigent populations who have traditionally received care in public hospital EDs.