An outbreak of hepatitis C virus infections among outpatients at a hematology/oncology clinic

BACKGROUND

Approximately 2.7 million persons in the United States have chronic hepatitis C virus (HCV) infection. Health care-associated HCV transmission can occur if aseptic technique is not followed. The authors suspected a health care-associated HCV outbreak after the report of 4 HCV infections among patients at the same hematology/oncology clinic.

OBJECTIVE

To determine the extent and mechanism of HCV transmission among clinic patients.

DESIGN

Epidemiologic analysis through a cohort study.

SETTING

Hematology/oncology clinic in eastern Nebraska.

PARTICIPANTS

Patients who visited the clinic from March 2000 through December 2001.

MEASUREMENTS

HCV infection status, relevant medical history, and clinic-associated exposures. Bivariate analysis and logistic regression were used to identify risk factors for HCV infection.

RESULTS

Of 613 clinic patients contacted, 494 (81%) underwent HCV testing. The authors documented infection in 99 patients who lacked previous evidence of HCV infection; all had begun treatment at the clinic before July 2001. Hepatitis C virus genotype 3a was present in all 95 genotyped samples and presumably originated from a patient with chronic hepatitis C who began treatment in March 2000. Infection with HCV was statistically significantly associated with receipt of saline flushes (P < 0.001). Shared saline bags were probably contaminated when syringes used to draw blood from venous catheters were reused to withdraw saline solution. The clinic corrected this procedure in July 2001.

LIMITATION

The delay between outbreak and investigation (>1 year) may have contributed to an underestimate of cases.

CONCLUSIONS

This large health care-associated HCV outbreak was related to shared saline bags contaminated through syringe reuse. Effective infection-control programs are needed to ensure high standards of care in outpatient care facilities, such as hematology/oncology clinics.

A large nosocomial outbreak of hepatitis C and hepatitis B among patients receiving pain remediation treatments

BACKGROUND AND OBJECTIVE

In August 2002, the Oklahoma State Department of Health received a report of six patients with unexplained hepatitis C virus (HCV) infection treated in the same pain remediation clinic. We investigated the outbreak's extent and etiology.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a retrospective cohort study of clinic patients, including a serologic survey, interviews of infected patients, and reviews of medical records and staff infection control practices. Patients received outpatient pain remediation treatments one afternoon a week in a clinic within a hospital. Cases were defined as HCV or hepatitis B virus (HBV) infections among patients who reported no prior diagnosis or risk factors for disease or reported previous risk factors but had evidence of acute infection.

RESULTS

Of 908 patients, 795 (87.6%) were tested, and 71 HCV-infected patients (8.9%) and 31 HBV-infected patients (3.9%) met the case definition. Multiple HCV genotypes were identified. Significantly higher HCV infection rates were found among individuals treated after an HCV-infected patient during the same visit (adjusted odds ratio [AOR], 6.2; 95% confidence interval [CI95], 2.4-15.8); a similar association was observed for HBV (AOR, 2.9; CI95, 1.3-6.5). Review of staff practices revealed the nurse anesthetist had been using the same syringe-needle to sequentially administer sedation medications to every treated patient each clinic day.

CONCLUSIONS

Reuse of needles-syringes was the mechanism for patient-to-patient transmission of HCV and HBV in this large nosocomial outbreak. Further education and stricter oversight of infection control practices may prevent future outbreaks.

Comparing office-based and ambulatory blood pressure monitoring in clinical trials

Ambulatory blood pressure monitoring (ABPM) is commonly used in clinical trials. Yet, its ability to detect blood pressure (BP) change in comparison to multiple office-based measurements has received limited attention. We recorded ambulatory and five daily pairs of random zero (RZ) BPs pre- and post-intervention on 321 adult participants in the multicentre Dietary Approaches to Stop Hypertension trial. Treatment effect estimates measured by ambulatory monitoring were similar to those measured by RZ and did not differ significantly for waking vs 24-h ambulatory measurements. For systolic BP, the standard deviations of change in mean 24-h ambulatory BP (8.0 mmHg among hypertensives and 6.0 mmHg among nonhypertensives) were comparable to or lower than the corresponding standard deviations of change in RZ-BP based on five daily readings (8.9 and 5.9 mmHg). The standard deviations of change for mean waking ambulatory BP (8.7 and 6.7 mmHg) were comparable to those obtained using three to four daily RZ readings. Results for diastolic BP were qualitatively similar. Ambulatory monitoring was more efficient (ie, a smaller sample size could detect a given BP change) than three to four sets of daily RZ readings and required fewer clinic visits. The average of 33 ambulatory BP readings during the waking hours had an efficiency comparable to that from the mean of four daily pairs of RZ-BPs. Participants readily accepted the ABPM devices, and their use requires less staff training. ABPM provides a useful alternative to RZ-BP measurements in clinical trials.

Healthy Eating Index scores are associated with blood nutrient concentrations in the third National Health And Nutrition Examination Survey

OBJECTIVES

The Healthy Eating Index (HEI) is a summary measure of dietary quality, based on a 100-point scale. Our objectives were to assess the HEI as a measure of dietary status through its correlation with nutritional biomarkers and to identify those biomarkers most associated with diet quality and healthful food intake patterns.

DESIGN

National Health and Nutrition Examination Survey (NHANES) III, 1988-94.

SUBJECTS

Adults (> or =17 years) with calculated HEI scores and blood nutrient data (n=16,467).

STATISTICAL ANALYSES PERFORMED

Weighted crude and partial Pearson correlation coefficients (r) between HEI scores and blood nutrients were calculated. Geometric mean blood nutrient concentrations were calculated for five HEI score categories (ranging from < or =50 to >80).

RESULTS

HEI score was positively correlated with serum (r=0.25) and red blood cell (r=0.27) folate, serum vitamins C (r=0.30) and E (r=0.21), and all serum carotenoids except lycopene (r=0.17 to 0.27). These blood nutrient concentrations were 21% to 175% higher for participants in the highest HEI score group (>80) compared with those in the lowest group (< or =50). Mean HEI scores were significantly (P<.0001) greater among the 42% of participants who took dietary supplements. Most correlations were attenuated when adjusted for additional factors.

CONCLUSIONS

HEI score is correlated with a wide range of blood nutrients; the strongest relationships are with biomarkers of fruit and vegetable intake. These results are an important step in the validation of the HEI, emphasizing its potential as a tool for nutrition and health studies.

Formula feeding in infancy is associated with adolescent body fat and earlier menarche

The tempo, level of growth and maturation during adolescence may have important implications to future adult health. The purpose of the study was to examine factors associated with menarche. Three hundred and forty girls, 9 to 14 years old, were selected from all age eligible girls at Kaiser Permanente Oahu (Honolulu). Girls' age, ethnicity, menstrual status and feeding pattern during infancy were obtained by questionnaire. The mean age of girls was 11.5 +/- 1.4 yr and the mean age at menarche among 112 (33%) girls who had reached menarche was 11.6 +/- 1.1 yr. In logistic regression, achievement of menarche was positively explained by age, Asian ethnicity and formula feeding during infancy. In simple linear regression, higher body mass index (BMI) and subcutaneous fat were also positively associated with formula feeding during infancy. The study suggests that girls who were formula fed deposit more body fat than girls who were breast-fed, resulting in early attainment of menarche.

Serum selenium and risk of prostate cancer in U.S. blacks and whites

Prostate cancer is the fourth most common cancer in men worldwide and the most common cancer in men in the United States, with reported incidence rates for U.S. blacks being the highest in the world. The etiology of prostate cancer and an explanation for the racial disparity in incidence in the United States remain elusive. Epidemiologic studies suggest that selenium, an essential trace element, may protect against the disease. To further explore this hypothesis, we measured serum selenium in 212 cases and 233 controls participating in a multicenter, population-based case-control study that included comparable numbers of U.S. black and white men aged 40-79 years. Serum selenium was inversely associated with risk of prostate cancer (comparing highest to lowest quartiles, OR = 0.71, 95% CI 0.39-1.28; p for trend = 0.11), with similar patterns seen in both blacks and whites. Cubic regression spline analysis of continuous serum selenium indicated a reduced risk of prostate cancer above concentrations of 0.135 microg/ml (median among controls) compared to a reference value set at the median of the lowest selenium quartile. Because both the selenoenzyme GPX and vitamin E can function as antioxidants, we also explored their joint effect. Consistent with other studies, the inverse association with selenium was strongest among men with low serum alpha-tocopherol concentrations. In conclusion, our results suggest a moderately reduced risk of prostate cancer at higher serum selenium concentrations, a finding that can now be extended to include U.S. blacks. Since selenium exposure varies widely throughout the world, further research on optimal concentrations for cancer prevention is justified.

Serum lycopene, other serum carotenoids, and risk of prostate cancer in US Blacks and Whites

Epidemiologic studies investigating the relation between individual carotenoids and risk of prostate cancer have produced inconsistent results. To further explore these associations and to search for reasons prostate cancer incidence is over 50% higher in US Blacks than Whites, the authors analyzed the serum levels of individual carotenoids in 209 cases and 228 controls in a US multicenter, population-based case-control study (1986-1989) that included comparable numbers of Black men and White men aged 40-79 years. Lycopene was inversely associated with prostate cancer risk (comparing highest with lowest quartiles, odds ratio (OR) = 0.65, 95% confidence interval (CI): 0.36, 1.15; test for trend, p = 0.09), particularly for aggressive disease (comparing extreme quartiles, OR = 0.37, 95% CI: 0.15, 0.94; test for trend, p = 0.04). Other carotenoids were positively associated with risk. For all carotenoids, patterns were similar for Blacks and Whites. However, in both the controls and the Third National Health and Nutrition Examination Survey, serum lycopene concentrations were significantly lower in Blacks than in Whites, raising the possibility that differences in lycopene exposure may contribute to the racial disparity in incidence. In conclusion, the results, though not statistically significant, suggest that serum lycopene is inversely related to prostate cancer risk in US Blacks and Whites.

Microsatellite instability in malignant melanomas

Microsatellite instability (MSI) is caused by deficient DNA mismatch repair, and results in a "mutator" phenotype. Recent studies have produced contradictory results about the frequency and significance of MSI in malignant melanomas. In this study, we therefore determined the time of onset and relative frequency of MSI during the progression of melanocytic tumours, including benign melanocytic naevi. We examined 7 different microsatellite loci in 9 melanocytic naevi, 25 primary malignant melanomas and 8 melanoma metastases. None of the melanocytic naevi showed MSI. In contrast, moderate frequency of MSI in 1/12 (8%) was detected in thin melanomas of <0.75 mm vertical thickness and in 1/8 (12%) of those with a thickness >0.75 mm and < 1.5 mm. The rate of MSI was increased in tumours thicker than 1.5 mm (2/5) and in melanoma metastases, with over 25% (2/8) of the lesions investigated. We conclude that MSI occurs in a considerable subset of malignant melanomas and that there is a pattern consistent with increasing frequency of MSI with progression of melanocytic tumours.

Barriers to mammography and Pap smear screening among women who recently had neither, one or both types of screening

There is legitimate concern about whether cancer screening programs and other types of prevention and early detection programs are designed to reach those most in need of services. Previous research on barriers to screening has generally addressed screening for specific cancers. The purpose of this study was to evaluate and compare the types and strengths of barriers to both mammography and Pap smear screening experienced by three groups of women. Five hundred and twenty-two women, aged 52-69, who were members of a large health maintenance organization (HMO), completed a survey about cancer screening and associated barriers. Women with no mammogram in the preceding 2 years and with no Pap smear in 3 years were classified into a "safety net" program. We classified women as falling into both (Pap smear and mammography), one (Pap smear or mammography), or neither safety nets. Results consistently revealed that women needing both tests had more numerous and more intense barriers than other women to both types of screening. Factor analyses and descriptive analyses both showed that the types of barriers experienced were very similar for mammography and Pap smear screening. The discussion addresses intervention implications and the additional research needed on women who need both mammogram and Pap smear screening and who have much higher cancer risk than other women.

Vertebral fracture prevalence among women screened for the Fracture Intervention Trial and a simple clinical tool to screen for undiagnosed vertebral fractures. Fracture Intervention Trial Research Group

OBJECTIVE

To evaluate the ability of self-reported risk factors to identify postmenopausal women likely to have extant vertebral fractures because approximately two thirds of women with radiographic evidence of vertebral fracture are unaware of the fracture.

PATIENTS AND METHODS

Questionnaire and spinal radiographic data were collected from postmenopausal women with a femoral neck bone mineral density T score of -1.6 or lower during screening for the Fracture Intervention Trial. Logistic regression was used to identify risk factors for extant vertebral fractures and to derive a final multivariable model.

RESULTS

Almost two thirds of 25,816 women 55 years and older met the bone density criterion, and 21% of those had an extant vertebral fracture. The final model consisted of 5 self-reported items: history of vertebral fracture, history of nonvertebral fracture, age, height loss, and diagnosis of osteoporosis. These were combined to yield a Prevalent Vertebral Fracture Index (PVFI). The prevalence of women with vertebral fracture varied from 3.8% to 62.3% over the range PVFI of 0 to greater than 5. Among the 13,051 women screened with spinal radiographs, a PVFI of 4 or greater identified 65.5% of women with vertebral fractures (sensitivity), with a specificity of 68.6%. Excluding 881 women who reported prior vertebral fractures reduced the sensitivity to 53.6 % and increased the specificity to 70.7% but did not alter the fracture prevalence at PVFI values less than 6.

CONCLUSION

In this population, 5 simple questions identified women who were likely to have undiagnosed vertebral fractures. Further research is needed to determine the validity of this index in other populations, including women without low bone mineral density.

Relation of low body mass to death and stroke in the systolic hypertension in the elderly program. The SHEP Cooperative Research Group

BACKGROUND

There are scant data on the effect of body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) on cardiovascular events and death in older patients with hypertension.

OBJECTIVE

To determine if low body mass in older patients with hypertension confers an increased risk of death or stroke.

PATIENTS

Participants were 3975 men and women (mean age, 71 years) enrolled in 17 US centers in the Systolic Hypertension in the Elderly Program trial, a randomized, double-blind, placebo-controlled clinical trial of lowdose antihypertensive therapy, with follow-up for 5 years.

MAIN OUTCOME MEASURES

Five-year adjusted mortality and stroke rates from Cox proportional hazards analyses.

RESULTS

There was no statistically significant relation of death or stroke with BMI in the placebo group (P = .47), and there was a U- or J-shaped relation in the treatment group. The J-shaped relation of death with BMI in the treated group (P = .03) showed that the lowest probability of death for men was associated with a BMI of 26.0 and for women with a BMI of 29.6; the curve was quite flat for women across a wide range of BMIs. For stroke, men and women did not differ, and the BMI nadir for both sexes combined was 29, with risk increasing steeply at BMIs below 24. Those in active treatment, however, had lower death and stroke rates compared with those taking placebo.

CONCLUSIONS

Among older patients with hypertension, a wide range of BMIs was associated with a similar risk of death and stroke; a low BMI was associated with increased risk. Lean, older patients with hypertension in treatment should be monitored carefully for additional risk factors.

Evaluating the public health impact of health promotion interventions: the RE-AIM framework

Progress in public health and community-based interventions has been hampered by the lack of a comprehensive evaluation framework appropriate to such programs. Multilevel interventions that incorporate policy, environmental, and individual components should be evaluated with measurements suited to their settings, goals, and purpose. In this commentary, the authors propose a model (termed the RE-AIM model) for evaluating public health interventions that assesses 5 dimensions: reach, efficacy, adoption, implementation, and maintenance. These dimensions occur at multiple levels (e.g., individual, clinic or organization, community) and interact to determine the public health or population-based impact of a program or policy. The authors discuss issues in evaluating each of these dimensions and combining them to determine overall public health impact. Failure to adequately evaluate programs on all 5 dimensions can lead to a waste of resources, discontinuities between stages of research, and failure to improve public health to the limits of our capacity. The authors summarize strengths and limitations of the RE-AIM model and recommend areas for future research and application.

Effect of dietary patterns on ambulatory blood pressure : results from the Dietary Approaches to Stop Hypertension (DASH) Trial. DASH Collaborative Research Group

We measured ambulatory blood pressure (ABP) in 354 participants in the Dietary Approaches to Stop Hypertension (DASH) Trial to determine the effect of dietary treatment on ABP (24-hour, day and night) and to assess participants' acceptance of and compliance with the ABP monitoring (ABPM) technique. After a 3-week run-in period on a control "typical" American diet, subjects (diastolic blood pressure [BP], 80 to 95 mm Hg; systolic BP, <160 mm Hg; mean age, 45 years) were randomly assigned to 1 of 3 diets for an 8-week intervention period: a continuation of the control diet; a diet rich in fruits and vegetables; and a "combination" diet that emphasized fruits, vegetables, and low-fat dairy products. We measured ABP at the end of the run-in and intervention periods. Both the fruit/vegetable and combination diets lowered 24-hour ABP significantly compared with the control diet (P<0. 0001 for systolic and diastolic pressures on both diets: control diet, -0.2/+0.1 mm Hg; fruit/vegetable diet, -3.2/-1.9 mm Hg; combination diet, -4.6/-2. 6 mm Hg). The combination diet lowered pressure during both day and night. Hypertensive subjects had a significantly greater response than normotensives to the combination diet (24-hour ABP, -10.1/-5.5 versus -2.3/-1.6 mm Hg, respectively). After correction for the control diet responses, the magnitude of BP lowering was not significantly different whether measured by ABPM or random-zero sphygmomanometry. Participant acceptance of ABPM was excellent: only 1 participant refused to wear the ABP monitor, and 7 subjects (2%) provided incomplete recordings. These results demonstrate that the DASH combination diet provides significant round-the-clock reduction in BP, especially in hypertensive participants.

Dietary Approaches to Stop Hypertension: rationale, design, and methods. DASH Collaborative Research Group

Epidemiologic studies across societies have shown consistent differences in blood pressure that appear to be related to diet. Vegetarian diets are consistently associated with reduced blood pressure in observational and interventional studies, but clinical trials of individual nutrient supplements have had an inconsistent pattern of results. Dietary Approaches to Stop Hypertension (DASH) was a multicenter, randomized feeding study, designed to compare the impact on blood pressure of 3 dietary patterns. DASH was designed as a test of eating patterns rather than of individual nutrients in an effort to identify practical, palatable dietary approaches that might have a meaningful impact on reducing morbidity and mortality related to blood pressure in the general population. The objectives of this article are to present the scientific rationale for this trial, review the methods used, and discuss important design considerations and implications.

A dietary approach to prevent hypertension: a review of the Dietary Approaches to Stop Hypertension (DASH) Study

BACKGROUND

Populations eating mainly vegetarian diets have lower blood pressure levels than those eating omnivorous diets. Epidemiologic findings suggest that eating fruits and vegetables lowers blood pressure.

HYPOTHESIS

Two hypotheses were tested: (1) that high intake of fruits and vegetables lowers blood pressure, and (2) that an overall dietary pattern (known as the DASH diet, or DASH combination diet) that is high in fruits, vegetables, nuts, and low-fat dairy products, emphasizes fish and chicken rather than red meat, and is low in saturated fat, cholesterol, sugar, and refined carbohydrate lowers blood pressure.

METHODS

Participants were 459 adults with untreated systolic blood pressure < 160 mmHg and diastolic blood pressure 80-95 mmHg. After a 3-week run-in on a control diet typical of Americans, they were randomized to 8 weeks receiving either the control diet, or a diet rich in fruits and vegetables, or the DASH diet. The participants were given all of their foods to eat, and body weight and sodium intake were held constant. Blood pressure was measured at the clinic and by 24-h ambulatory monitoring.

RESULTS

The DASH diet lowered systolic blood pressure significantly in the total group by 5.5/3.0 mmHg, in African Americans by 6.9/3.7 mmHg, in Caucasians by 3.3/2.4 mmHg, in hypertensives by 11.6/5.3 mmHg, and in nonhypertensives by 3.5/2.2 mmHg. The fruits and vegetables diet also reduced blood pressure in the same subgroups, but to a lesser extent. The DASH diet lowered blood pressure similarly throughout the day and night.

CONCLUSIONS

The DASH diet may offer an alternative to drug therapy in hypertensives and, as a population approach, may prevent hypertension, particularly in African Americans.

Interactive computer technology, behavioral science, and family practice

In this paper we discuss conceptual and practical uses for interactive computer applications (ICAs) for family practice, with an emphasis on implications for patient self-management, physician-patient relationships, primary care research, and health care systems quality improvement. We discuss recent behavioral science advances in patient self-management and the advantages and potential limitations of ICAs for medicine. We describe the benefits and risks of using ICAs for providing information, coping-skills training, and social support for patients and for improving the consistency and quality of care given by physicians. There are currently many effective ICAs, and they will play a central role in future health care. There is also the risk of inappropriate use of ICAs. We provide a summary of the empirical literature examining the use of ICAs to aid patients and providers in behavioral change and guidelines adherence efforts. We advise those people researching and applying ICAs in health care to be bold in what they attempt, but cautious in what they claim. Rigorous scientific evaluation and standardized reporting criteria can help quicken this advance, and there are important policy and ethical issues to consider. We conclude with a list of issues for family practices to consider when selecting and using ICAs.

Recent patterns of hormone replacement therapy use in a large managed care organization

Rates of hormone replacement therapy (HRT) in women have varied substantially over the last 25 years. Data on the impact of recent recommendations for widespread use to prevent cardiovascular disease and osteoporosis and factors that influence use are needed. We attempted to (1) describe recent trends in HRT use, (2) investigate the relationship between HRT use and prepaid drug benefit, and (3) detail prescribing frequencies by provider specialty. We conducted a cross-sectional analysis of annual HRT pharmacy dispensings from 1986 to 1995 in a large HMO to all female HMO members aged 45 years and older. HRT rates increased among all age categories, although the magnitude of change varied by age. Highest rates of use were found in those 50-59 years old. Although combined estrogen-progestin use increased, 57% of all estrogen users did not receive progestin in 1995. Unopposed estrogen use was largely limited to hysterectomized women. Women of all ages with no prepaid drug benefit as part of their HMO coverage had the lowest HRT rates. Internal medicine, obstetrics/gynecology, and family practice providers prescribed over 90% of HRT, and prescriber specialty varied with user age. HRT use increased in the HMO from 1986 to 1995, especially among younger women. In 1995, about half of women aged 50-64 years received one or more HRT dispensings. As the benefits, risks, and cost effectiveness of HRT depend on the duration of use, additional information on current use duration is needed. Combined estrogen-progestin use increased and appeared appropriate to hysterectomy status. Research is needed to determine if lower HRT use rates among women without a prepaid drug benefit indicate less prophylactic HRT use, particularly among younger women, for whom this lack of coverage was relatively common.

Cost-effectiveness of a hospital-based smoking cessation intervention

OBJECTIVES

This study evaluated the cost-effectiveness of a smoking cessation and relapse-prevention program for hospitalized adult smokers from the perspective of an implementing hospital. It is an economic analysis of a two-group, controlled clinical trial in two acute care hospitals owned by a large group-model health maintenance organization. The intervention included a 20-minute bedside counseling session with an experienced health counselor, a 12-minute video, self-help materials, and one or two follow-up calls.

METHODS

Outcome measures were incremental cost (above usual care) per quit attributable to the intervention and incremental cost per discounted life-year saved attributable to the intervention.

RESULTS

Cost of the research intervention was $159 per smoker, and incremental cost per incremental quit was $3,697. Incremental cost per incremental discounted life-year saved ranged between $1,691 and $7,444, much less than most other routine medical procedures. Replication scenarios suggest that, with realistic implementation assumptions, total intervention costs would decline significantly and incremental cost per incremental discounted life-year saved would be reduced by more than 90%, to approximately $380.

CONCLUSIONS

Providing brief smoking cessation advice to hospitalized smokers is relatively inexpensive, cost-effective, and should become a part of the standard of inpatient care.

Biochemical evidence for pathogenicity of rhodopsin kinase mutations correlated with the oguchi form of congenital stationary night blindness

Rhodopsin kinase (RK), a rod photoreceptor cytosolic enzyme, plays a key role in the normal deactivation and recovery of the photoreceptor after exposure to light. To date, three different mutations in the RK locus have been associated with Oguchi disease, an autosomal recessive form of stationary night blindness in man characterized in part by delayed photoreceptor recovery [Yamamoto, S. , Sippel, K. C., Berson, E. L. & Dryja, T. P. (1997) Nat. Genet. 15, 175-178]. Two of the mutations involve exon 5, and the remaining mutation occurs in exon 7. Known exon 5 mutations include the deletion of the entire exon sequence [HRK(X5 del)] and a missense change leading to a Val380Asp substitution in the encoded product (HRKV380D). The mutation in exon 7 is a 4-bp deletion in codon 536 leading to premature termination of the encoded polypeptide [HRKS536(4-bp del)]. To provide biochemical evidence for pathogenicity of these mutations, wild-type human rhodopsin kinase (HRK) and mutant forms HRKV380D and HRKS536(4-bp del) were expressed in COS7 cells and their activities were compared. Wild-type HRK catalyzed light-dependent phosphorylation of rhodopsin efficiently. In contrast, both mutant proteins were markedly deficient in catalytic activity with HRKV380D showing virtually no detectible activity and HRKS536(4-bp del) only minimal light-dependent activity. These results provide biochemical evidence to support the pathogenicity of the RK mutations in man.

The medical care system and prevention: the need for a new paradigm

The American medical care system falls to provide effective prevention services even though some prevention services are among the most cost-effective medical procedures available. Many prevention services are routinely delivered in inefficient or ineffective ways, and new technologies may be widely and aggressively implemented despite serious doubts about their efficacy and cost-effectiveness. The barriers to effective prevention services result from conceptual limitations in our model of medical care systems, particularly the lack of a population-based perspective. A change in paradigm is needed before reforms in our health care system can improve health without bankrupting the nation.

RNA fingerprinting displays UVB-specific disruption of transcriptional control in human melanocytes

In mammalian cells, UV induces a limited set of early transcribed genes, which overlaps with the set of genes induced by tumor promoting drugs such as 12-O-tetradecanoyl phorbol-13-acetate (TPA). Among these are genes for transcription factors, the activation of which leads to complex secondary changes in expression of multiple target genes. How these delayed pleiotropic UV effects on transcription may contribute to initiation of melanoma skin cancer is poorly understood. We analyzed changes in the relative abundances of 1900 transcripts in newborn human melanocytes 8 h after treatment with UVB, TPA, and cycloheximide in all combinations, using RNA arbitrarily primed PCR for differential display. The relative abundances of 205 transcripts (11% of all transcripts surveyed) were altered by one or more of the treatment combinations. Fourteen of the 77 genes up-regulated by TPA were also up-regulated by UVB, but 60 of the TPA up-regulated genes were down-regulated by UVB, indicating both intersecting and independent signal transduction pathways for UVB and TPA. A number of UVB and TPA target genes were identified by cDNA cloning. Consistent with UVB induction of a partly transformed phenotype in mammalian cells, UVB antagonized the TPA-inducible expression of tumor-suppressive tropomyosin 3 mRNA. In addition, UVB may impair mitochondrial functioning and induce oxidative stress by strong down-regulation of mitochondrial transcription. Finally, increased expression of the dihydropteridine reductase gene, a major regulator of the cellular tetrahydrobiopterin pool, was linked to the UV pathway.

Calcium intake and fracture risk: results from the study of osteoporotic fractures

The relation between dietary calcium, calcium, and vitamin D supplements and the risk of fractures of the hip (n = 332), ankle (n = 210), proximal humerus (n = 241), wrist (n = 467), and vertebrae (n = 389) was investigated in a cohort study involving 9,704 US white women aged 65 years or older. Baseline assessments took place in 1986-1988 in four US metropolitan areas. Dietary calcium intake was assessed at baseline with a validated food frequency questionnaire. Data on new nonvertebral fractures were collected every 4 months during a mean of 6.6 years of follow-up; identification of new vertebral fractures was based on comparison of baseline and follow-up radiographs of the spine done a mean of 3.7 years apart. Results were adjusted for numerous potential confounders, including weight, physical activity, estrogen use, protein intake, and history of falls, osteoporosis, and fractures. There were no important associations between dietary calcium intake and the risk of any of the fractures studied. Current use of calcium supplements was associated with increased risk of hip (relative risk = 1.5, 95% confidence interval 1.1-2.0) and vertebral (relative risk = 1.4, 95% confidence interval 1.1-1.9) fractures; current use of Tums antacid tablets was associated with increased risk of fractures of the proximal humerus (relative risk = 1.7, 95% confidence interval 1.3-2.4). There was no evidence of a protective effect of vitamin D supplements. Although a true adverse effect of calcium supplements on fracture risk cannot be ruled out, it is more likely that our findings are due to inadequately controlled confounding by indications for use of supplements. In conclusion, this study did not find a substantial beneficial effect of calcium on fracture risk.

Does gender affect response to a brief clinic-based smoking intervention?

INTRODUCTION

Although recent reviews suggest few gender differences in smoking-cessation outcomes, it is important to establish whether gender differences exist in response to the brief interventions increasingly recommended as part of routine medical care.

METHODS

We used data from an efficacious primary care-based smoking intervention to examine gender differences in smoking characteristics, use of intervention components, self-reported quitting activities, and cessation outcomes among all smokers randomized to receive clinician advice and nurse-assisted intervention (n = 1,978, 58% female).

RESULTS

Although female and male smokers differed on a number of sociodemographic and smoking-related characteristics, they were equally likely to participate in each step of the recommended intervention. Female and male smokers were also equally likely to report quit attempts and cessation at 3, 12, and 3 and 12 months (combined long-term cessation endpoint). Similarly, no gender difference in relapse at 12 months was seen. Women attempting to quit used a greater number and variety of smoking-cessation strategies, suggesting that, although outcomes were similar, the processes of cessation may vary by gender.

CONCLUSIONS

Since this brief intervention in primary care was equally efficacious and acceptable to female and male smokers, broader implementation in medical settings of this population-based approach to reducing tobacco use is warranted. Indeed, widespread implementation of smoking-cessation programs in medical settings may particularly benefit women, who are more likely than men to have contacts with the medical care system.

A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group

BACKGROUND

It is known that obesity, sodium intake, and alcohol consumption factors influence blood pressure. In this clinical trial, Dietary Approaches to Stop Hypertension, we assessed the effects of dietary patterns on blood pressure.

METHODS

We enrolled 459 adults with systolic blood pressures of less than 160 mm Hg and diastolic blood pressures of 80 to 95 mm Hg. For three weeks, the subjects were fed a control diet that was low in fruits, vegetables, and dairy products, with a fat content typical of the average diet in the United States. They were then randomly assigned to receive for eight weeks the control diet, a diet rich in fruits and vegetables, or a "combination" diet rich in fruits, vegetables, and low-fat dairy products and with reduced saturated and total fat. Sodium intake and body weight were maintained at constant levels.

RESULTS

At base line, the mean (+/-SD) systolic and diastolic blood pressures were 131.3+/-10.8 mm Hg and 84.7+/-4.7 mm Hg, respectively. The combination diet reduced systolic and diastolic blood pressure by 5.5 and 3.0 mm Hg more, respectively, than the control diet (P<0.001 for each); the fruits-and-vegetables diet reduced systolic blood pressure by 2.8 mm Hg more (P<0.001) and diastolic blood pressure by 1.1 mm Hg more than the control diet (P=0.07). Among the 133 subjects with hypertension (systolic pressure, > or =140 mm Hg; diastolic pressure, > or =90 mm Hg; or both), the combination diet reduced systolic and diastolic blood pressure by 11.4 and 5.5 mm Hg more, respectively, than the control diet (P<0.001 for each); among the 326 subjects without hypertension, the corresponding reductions were 3.5 mm Hg (P<0.001) and 2.1 mm Hg (P=0.003).

CONCLUSIONS

A diet rich in fruits, vegetables, and low-fat dairy foods and with reduced saturated and total fat can substantially lower blood pressure. This diet offers an additional nutritional approach to preventing and treating hypertension.

Broadband ultrasound attenuation predicts fractures strongly and independently of densitometry in older women. A prospective study. Study of Osteoporotic Fractures Research Group

BACKGROUND

Quantitative ultrasound of bone is a new radiation-free technique that measures bone mass and may assess bone quality. Retrospective studies have suggested that low-bone ultrasound of the calcaneus is associated with an increased risk for hip and other fractures in older women.

OBJECTIVES

To establish the utility of calcaneal quantitative ultrasound of bone for the prediction of fractures and to compare quantitative ultrasound of bone with bone mineral densitometry by performing a prospective cohort study within the Study of Osteoporotic Fractures.

SUBJECTS AND METHODS

We studied 6189 postmenopausal women older than 65 years of 4 US clinical centers. Broadband ultrasound attenuation (BUA), a measurement of the differential attenuation of sound waves transmitted through the calcaneus, and bone mineral density of the calcaneus and hip were measured. Subsequent hip and other nonspine fractures were documented during a mean follow-up of 2.0 years.

RESULTS

In age- and clinic-adjusted analyses, each SD reduction in calcaneal BUA was associated with a doubling of the risk for hip fractures (relative risk [RR], 2.0; 95% confidence interval [CI], 1.5-2.7); a similar relationship was observed with bone mineral density of the calcaneus (RR, 2.2; 95% CI, 1.9-3.0) and femoral neck (RR, 2.6; 95% CI, 1.9-3.8). After adjustment for bone mineral density of the femoral neck, BUA was still associated with an increased risk for hip fracture (RR, 1.5; 95% CI, 1.0-2.1). Intertrochanteric fractures in particular were strongly associated with a low BUA measurement (RR, 3.3; 95% CI, 2.0-5.5).

CONCLUSIONS

Broadband ultrasound attenuation predicts the occurrence of fractures in older women and is a useful diagnostic test for osteoporosis. The strength of the association between BUA and fracture is similar to that observed with bone mineral density.