Factors related to colonization with Oxalobacter formigenes in U.S. adults.

GOALS: To elucidate the determinants of Oxalobacter formigenes colonization in humans. BACKGROUND: O. formigenes is a gram-negative anaerobic bacterium that colonizes the colon of a substantial proportion of the normal population and metabolizes dietary and endogenous oxalate. The bacterium has been associated with a large reduction in the odds of recurrent calcium oxalate kidney stones. Subjects were 240 healthy individuals from Massachusetts and North Carolina. O. formigenes was detected by culture of fecal swabs. Information on factors of interest was obtained by telephone interviews and self-administered questionnaires. STUDY RESULTS: The overall prevalence of O. formigenes was 38%. Use of specific antibiotics previously thought to affect the bacterium was significantly related to colonization, with prevalences of 17%, 27%, and 36%, for those who had used these drugs <1, 1-5, and >5 years ago, compared with 55% in nonusers. There were no significant associations with demographic factors, nutrient intake, or medical history, although the prevalence appeared to increase somewhat with increasing oxalate consumption. CONCLUSIONS: Some antibiotics markedly affect colonization with O. formigenes. Although no other factor was identified as having a material influence on the prevalence of the bacterium, there is much to learn about how an individual acquires the organism and which factors affect persistence of colonization.

Classification of the myelodysplastic syndrome in a national registry of recently diagnosed patients.

BACKGROUND: It is not known to what extent the WHO classification scheme for MDS has been adopted in clinical practice. METHODS: We reviewed the medical records of 200 newly diagnosed MDS patients enrolled in our national registry during the years 2006-2008 to determine the scheme used. RESULTS: Clear WHO subtypes were recorded for 45.0% of patients, compared to 5.5% for FAB subtypes; 28.0% had MDS documented but without WHO or FAB subtype, and for 22.5%, the schema was unclear. CONCLUSION: Although many MDS patients do not have a subtype or schema documented, when they do, the WHO system is widely used.

Risk factors for leukemia in Thailand.

A case-control study of adult-onset leukemia was conducted in Bangkok, Thailand to explore the contribution of cellular telephone use and other factors to the etiology of the disease; 180 cases (87 acute myeloblastic leukemia, 40 acute lymphoblastic leukemia, 44 chronic myelogenous leukemia, eight chronic lymphocytic leukemia, one unclassified acute leukemia) were compared with 756 age- and sex-matched hospital controls. Data were obtained by interview; odds ratios (ORs) were estimated by unconditional logistic regression. There was no clear association with cellular telephone phone use, but durations were relatively short (median 24-26 months), and there was a suggestion that risk may be increased for those with certain usage practices (ORs, 1.8-3.0 with lower confidence intervals >1.0) and those who used GSM service (OR, 2.1; 95% confidence interval, 1.1-4.0). Myeloid leukemia (acute and chronic combined) was associated with benzene (OR, 3.9; 95% confidence interval, 1.3-11), a nonspecific group of other solvents (2.3; 1.1-4.9), occupational pesticides that were mostly unspecified (3.8; 2.1-7.1), and working with or near powerlines (4.3; 1.3-15). No associations were found for diagnostic X-rays, cigarette smoking, or other occupational exposures.

Oxalobacter formigenes may reduce the risk of calcium oxalate kidney stones.

Most kidney stones are composed primarily of calcium oxalate. Oxalobacter formigenes is a Gram-negative, anaerobic bacterium that metabolizes oxalate in the intestinal tract and is present in a large proportion of the normal adult population. It was hypothesized that the absence of O. formigenes could lead to increased colonic absorption of oxalate, and the subsequent increase in urinary oxalate could favor the development of stones. To test this hypothesis, a case-control study involving 247 adult patients with recurrent calcium oxalate stones and 259 age-, gender-, and region-matched control subjects was performed. The prevalence of O. formigenes, determined by stool culture, was 17% among case patients and 38% among control subjects; on the basis of multivariate analysis controlling demographic factors, dietary oxalate, and antibiotic use, the odds ratio for colonization was 0.3 (95% confidence interval 0.2 to 0.5). The inverse association was consistently present within strata of age, gender, race/ethnicity, region, and antibiotic use. Among the subset of participants who completed a 24-h urine collection, the risk for kidney stones was directly proportional to urinary oxalate, but when urinary factors were included in the multivariable model, the odds ratio for O. formigenes remained 0.3 (95% confidence interval 0.1 to 0.7). Surprisingly, median urinary oxalate excretion did not differ with the presence or absence of O. formigenes colonization. In conclusion, these results suggest that colonization with O. formigenes is associated with a 70% reduction in the risk for being a recurrent calcium oxalate stone former.

Recent trends in use of herbal and other natural products.

BACKGROUND: The benefits of herbal and other natural products (dietary supplements) are increasingly cited in the media. Dramatic increases in use reported during the last decade have led to growing concerns about efficacy and safety. METHODS: To determine which dietary supplements American adults use, whether the prevalence has continued to increase in recent years, and whether popularity of individual supplements has changed, demographic information and details of use of all medicines and dietary supplements in the preceding week were obtained by telephone interview from February 1998 through December 2002 from households in 48 contiguous states and the District of Columbia. Participants included randomly selected residents of households with telephones; compared with 2000 US Census data, participants were representative of the US population. The main outcome measure was the weekly prevalence of dietary supplement use, alone or in a multicomponent product. RESULTS: There were 8470 subjects 18 years or older. The annual prevalence of dietary supplement use increased from 14.2% in 1998-1999 to 18.8% in 2002. Although use did not change among younger subjects, it doubled for men and women 65 years or older. Use of Ginkgo biloba and Panax ginseng declined during the study, while lutein use increased dramatically, because of its addition to multivitamin products. The overall 2002 prevalence excluding lutein use was 13.9%. CONCLUSIONS: The popularity of specific supplements has varied over time and differs according to age and sex. The sharp increase in supplement use in the 1990s appears to have slowed. However, the addition of supplements, such as lutein and lycopene, to mainstream multivitamins has become an important source of exposure.

Recent patterns of medication use in the ambulatory adult population of the United States: the Slone survey.

CONTEXT: Data on the range of prescription and over-the-counter drug use in the United States are not available. OBJECTIVE: To provide recent population-based information on use of all medications, including prescription and over-the-counter drugs, vitamins and minerals, and herbal preparations/natural supplements in the United States. DESIGN, SETTING, AND PARTICIPANTS: Ongoing telephone survey of a random sample of the noninstitutionalized US population in the 48 continental states and the District of Columbia; data analyzed here were collected from February 1998 through December 1999. MAIN OUTCOME MEASURE: Use of medications, by type, during the preceding week, compared by demographic characteristics. RESULTS: Among 2590 participants aged at least 18 years, 81% used at least 1 medication in the preceding week; 50% took at least 1 prescription drug; and 7% took 5 or more. The highest overall prevalence of medication use was among women aged at least 65 years, of whom 12% took at least 10 medications and 23% took at least 5 prescription drugs. Herbals/supplements were taken by 14% of the population. Among prescription drug users, 16% also took an herbal/supplement; the rate of concurrent use was highest for fluoxetine users, at 22%. Reasons for drug use varied widely, with hypertension and headache mentioned most often (9% for each). Vitamins/minerals were frequently used for nonspecific reasons such as "health" (35%); herbals/supplements were also most commonly used for "health" (16%). CONCLUSIONS: In any given week, most US adults take at least 1 medication, and many take multiple agents. The substantial overlap between use of prescription medications and herbals/supplements raises concern about unintended interactions. Documentation of usage patterns can provide a basis for improving the safety of medication use.