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Biomedical subjects

James A Greenberg

Publications and source records attributed to James A Greenberg.

15 recordsLinked to original sources
PubMed2006

Correcting biases in estimates of mortality attributable to obesity.

OBJECTIVE: To assess whether a recent study that found a relatively small number of excess deaths attributable to obesity may have underestimated by not correcting for statistical biases. RESEARCH METHODS AND PROCEDURES: This prospective cohort study used data from the First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study. Survival analyses were conducted using 9690 individuals 32 to 87 years of age and 1886 all-cause deaths during a 9.1-year follow-up. Corrections were made for the reputed regression-dilution bias by using the average BMI during the decade before follow-up as predictor. Corrections for the reputed reverse-causation bias were made by excluding participants with a history of serious illness. Attributable fractions were calculated and used to estimate excess deaths. RESULTS: The uncorrected estimate of excess deaths attributable to obesity (BMI > or =30) was 41.9, using 18.5 to 25 kg/m(2) as ideal-weight category. Using average BMI as predictor increased the estimate to 93.3. Correcting for reverse-causation effects increased the estimate further to 131.1 (range, 93.3 to 169.0). The uncorrected hazard ratio, 1.25, was increased to 1.41 by using average BMI as predictor, and then to 2.40 by correcting for reverse causation. Using BMI 21 to 25 kg/m(2) and 23 to 25 kg/m(2) as ideal-weight categories increased the corrected estimates to 144.6 (range, 80.5 to 177.2) and 164.1 (range, 103.8 to 194.9), respectively. Larger increases were found for overweight and Grade 2 to 4 obesity (BMI > or =35 kg/m(2)). For overweight, the uncorrected estimate using 18.5 to 25 kg/m(2) as ideal-weight category was -88.3 and the corrected estimate using 23 to 25 kg/m(2) as ideal-weight category was 205.4 (range, 114.5 to 296.3). DISCUSSION: Correcting for statistical biases and using higher ideal-weight categories increased the estimate of excess deaths attributable to obesity by approximately 400% and changed the negative estimate for overweight to a large positive estimate.

Adult↗
PubMed2006

Coffee, diabetes, and weight control.

Several prospective epidemiologic studies over the past 4 y concluded that ingestion of caffeinated and decaffeinated coffee can reduce the risk of diabetes. This finding is at odds with the results of trials in humans showing that glucose tolerance is reduced shortly after ingestion of caffeine or caffeinated coffee and suggesting that coffee consumption could increase the risk of diabetes. This review discusses epidemiologic and laboratory studies of the effects of coffee and its constituents, with a focus on diabetes risk. Weight loss may be an explanatory factor, because one prospective epidemiologic study found that consumption of coffee was followed by lower diabetes risk but only in participants who had lost weight. A second such study found that both caffeine and coffee intakes were modestly and inversely associated with weight gain. It is possible that caffeine and other constituents of coffee, such as chlorogenic acid and quinides, are involved in causing weight loss. Caffeine and caffeinated coffee have been shown to acutely increase blood pressure and thereby to pose a health threat to persons with cardiovascular disease risk. One short-term study found that ground decaffeinated coffee did not increase blood pressure. Decaffeinated coffee, therefore, may be the type of coffee that can safely help persons decrease diabetes risk. However, the ability of decaffeinated coffee to achieve these effects is based on a limited number of studies, and the underlying biological mechanisms have yet to be elucidated.

Animals↗
PubMed2005

Consumption of sweetened dried cranberries versus unsweetened raisins for inhibition of uropathogenic Escherichia coli adhesion in human urine: a pilot study.

OBJECTIVES: The aim of this study was to determine whether consumption of sweetened dried cranberries elicits urinary anti-adherence properties against Escherichia coli as previously demonstrated with cranberry juice and/or sweetened cranberry juice cocktail, compared to unsweetened raisins. DESIGN: Uropathogenic E. coli isolates were obtained from five women with culture-confirmed urinary tract infections (UTIs). Four urine samples were collected from each subject. The first urine sample was collected before any study intervention. The second urine sample was collected 2-5 hours after consumption of one box (42.5 g) of raisins. The third urine sample was collected 5-7 days later. The final urine sample was collected 2-5 hours after consumption of approximately 42.5 g of dried cranberries. MATERIALS AND METHODS: E. coli isolates were incubated separately in each of the four urine samples collected from the five subjects. Bacteria were harvested from the urine and tested for the ability to prevent adhesion of P-fimbriated E. coli bacteria using a mannose-resistant hemagglutination assay with human red blood cells (A1, Rh+). RESULTS: Of the urine samples collected after dried cranberry consumption, one demonstrated 50% antiadherence activity, two demonstrated 25% activity, and two did not show any increased activity. None of the control urine samples and none of the postraisin consumption samples demonstrated any inhibitory activity. CONCLUSIONS: Data from this pilot study on only five subjects suggest that consumption of a single serving of sweetened dried cranberries may elicit bacterial antiadhesion activity in human urine, whereas consumption of a single serving of raisins does not. Further studies are needed to verify the antiadhesion effect of sweetened dried cranberries. In addition, dose-response and pharmacokinetics of the active compounds in the dried cranberries need to be determined. If clinical research is positive, dried cranberries could potentially be a viable alternative to cranberry juice consumption for prevention of UTIs.

Adult↗
PubMed2004

Randomized comparison of chromic versus fast-absorbing polyglactin 910 for postpartum perineal repair.

OBJECTIVE: We conducted a randomized trial to evaluate the healing characteristics of chromic versus fast-absorbing polyglactin 910. METHODS: Laboring women were randomly assigned to chromic or fast-absorbing polyglactin for perineal repairs. Subjects were evaluated at 24-48 hours, 10-14 days, and 6-8 weeks to assess perineal and uterine pain, analgesic use, presence of residual suture, and wound dehiscence. RESULTS: Between April 2002 and January 2003, 1,361 subjects were randomly assigned. Two thirds of women in each group (459 fast-absorbing polyglactin and 449 chromic) required sutures for perineal repairs. Women were evaluated according to randomization assignment. Overall, 794 (87%) of subjects received the appropriate allocated suture to repair a perineal laceration (399 of 459, 86.9% fast-absorbing polyglactin 910; 395 of 449, 88% chromic catgut). At 24-48 hours, there was a statistically significant reduction in uterine cramping pain (25% versus 34%; P =.006) in subjects randomly assigned to fast-absorbing polyglactin. At 10-14 days, there were no statistically significant differences between the groups. At 6-8 weeks there was, again, a statistically significant reduction in uterine cramping pain (1% versus 4%; P =.017) and a statistically significant decrease in analgesic use (5% versus 10%; P =.048) in subjects randomly assigned to fast-absorbing polyglactin. Finally, at 6-8 weeks postpartum there was no difference in residual suture (2 of 175 versus 2 of 134; P =.802) or wound breakdowns (4 of 175 versus 3 of 134; P =.959) for fast-absorbing polyglactin 910 and chromic catgut, respectively. CONCLUSION: Our data suggest that fast-absorbing polyglactin 910 and chromic elicit similar postpartum perineal discomfort. In contrast to previous studies evaluating standard polyglactin, our trial demonstrated that fast-absorbing polyglactin rarely requires late removal and has a similar wound breakdown profile as compared with chromic. LEVEL OF EVIDENCE: I

Catgut↗
PubMed2003

Triplets after cloacal malformation repair.

BACKGROUND: Patients with cloacal malformations at birth usually require multiple surgical procedures to correct their anatomic defects. In addition, many also have associated Müllerian anomalies. Those who conceive after repairs invariably are considered "high-risk" pregnancies and are considered poor candidates for maintaining multiple gestations. Further, because of the nature of their defects and their repairs, following such patients with multiple gestation presents unique challenges. CASE: A 29-year-old multipara conceived triplets and delivered at 30 weeks with a good maternal and neonatal outcome. CONCLUSIONS: Patients with repaired cloacal abnormalities present unique challenges and risks compared to the general population with regard to the risks of multiple pregnancies.

Adult↗
PubMed2003

Removing confounders from the relationship between mortality risk and systolic blood pressure at low and moderately increased systolic blood pressure.

OBJECTIVE: To assess the relationship between mortality risk and systolic blood pressure (SBP) at low and moderately increased SBP (less than the 70th percentile) before and after correcting for the regression-dilution bias and J-curve effects. DESIGN: Cohort study. SETTING: The First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study. PARTICIPANTS: The 6839 individuals who participated in the 1982-1984 survey for whom there were no missing data (age range 34-87 years). MAIN OUTCOME MEASURE: Cardiovascular disease mortality (n = 678) during a 9-year follow-up. METHODS: Corrections were made for the regression-dilution bias by using average SBP during the decade before baseline as the mortality predictor, and for J-curve effects by excluding individuals who exhibited high age-stratified mortality rates and a decrease in SBP. Cox's regression was used to analyse the follow-up relationship between mortality risk and SBP. RESULTS: The corrected relative cardiovascular disease mortality risk was 1.23 (95% confidence interval (CI), 1.16 to 1.31) for a 10 mmHg increase in SBP. The relationship was monotonically positive starting at the lowest SBP category in the analysis (< 115 mmHg), and robustly so above about the 32nd percentile (120 mmHg). The equivalent uncorrected result was 1.08 (95% CI, 1.05 to 1.13), and the relationship was J-shaped and became positive above about the 68th percentile (135 mmHg). Below the 70th percentile of SBP, individuals in the corrected analysis were 89% of all individuals. CONCLUSION: These two corrections transformed the relationship between mortality risk and SBP at low and moderately increased SBP from no association to a robustly positive association starting at 120 mmHg, for the majority of individuals.

Adult↗
PubMed2003

Value of routine urine culture in the assessment of preterm labor.

OBJECTIVE: To assess the utility and expense of routine urine culture in women evaluated for preterm labor. STUDY DESIGN: A retrospective study of 1,429 patients evaluated for preterm labor over a calendar year. Patients evaluated for preterm labor were identified using the hospital's admissions database and then cross-referenced with the hospital microbiology laboratory's database to identify those who had urine cultures sent as part of their evaluation. The charts of patients with a positive urine culture were further reviewed to evaluate the diagnosis and outcome. RESULTS: Five hundred twelve urine cultures were sent for analysis of preterm labor, and 6 (1.2%) reported growth of > 100,000 colonies of a single bacterium. Of these 6 patients, 5 reported symptoms consistent with a urinary tract infection, while the 6th was asymptomatic. Fisher's exact test showed no clinical significance for a positive urine culture as a predictor of preterm delivery (P = .68). Sensitivity was 0.7% (95% CI, 0.0-4.3), and specificity was 98.6% (95% CI, 96.7-99.5). A cost difference of $29,676 existed between charges and reimbursements. A positive culture was not a significant risk factor for preterm delivery. The 1 patient who delivered preterm with a positive culture probably had cervical incompetence as the cause of preterm delivery. CONCLUSION: The routine use of urine cultures in the assessment of preterm labor is costly and adds little value to obtaining a diagnosis except in the presence of specific complaints at our institution. Urine culture identified a single patient with asymptomatic bacteriuria being evaluated for preterm labor, and she probably had another etiology for her advanced cervical examination.

Adult↗
PubMed2002

Hypothesis - the J-shaped follow-up relation between mortality risk and disease risk-factor is due to statistical confounding.

There is currently conflicting evidence from longitudinal follow-up studies concerning the relation between mortality risk and disease risk factor at low levels or the risk factor. This applies to risk factors such as blood pressure, cholesterol, and body-mass index. In some studies, this relation was found to be positive. In others it was negative. This is an issue of importance to clinical and public-health policy, because a negative relation between mortality risk and blood pressure, for instance, implies that anithypertensive medication which lowers blood pressure below a critical threshold could be dangerous. It seemed likely that the conflict could be due to statistical confounding that artifactually elevates mortality risk at low risk-factor levels in survival analyses of longitudinal data. The present paper describes a crude analysis using data from the Framingham Offspring Study to test the idea that such statistical confounding could be caused by the decrease in risk factor with age among subjects near the end of the lifespan (referred to as late-life subjects). The analysis yielded evidence supporting this idea. on the basis of the findings it is hypothesized that: (1). the decrease in risk factor with age during late life causes the late-life bias. This bias distorts a positive relation between mortality risk and risk factor to appear U- or J-shaped in mixed-age adult follow-up cohorts; and (2). removal of the late-life and reverse-causation biases will show that this relation is monotonically positive.

Adult↗
PubMedDate not supplied

Uterine artery embolization and hysteroscopic resection to treat retained placenta accreta: A case report.

Retained placenta is a serious cause of postpartum hemorrhage. Compounding this problem is the rare finding of a retained placenta accreta. Different authors have presented management options for retained placenta accreta that include methotrexate, uterine artery embolization, dilation and curettage, hysteroscopic loop resection, and hysterectomy. We report here on a patient who was diagnosed with a retained placenta accreta and underwent successful conservative treatment with uterine artery embolization followed by hysteroscopic morcellation. Whereas other methods have failed due to bleeding and/or infection, this case illustrates a potential new means of addressing this challenging obstetrical complication.

Adult↗
PubMedDate not supplied

The Greenberg hysteroscopy speculum: a new instrument for hysteroscopy.

OBJECTIVES: Although the ubiquitous Graves speculum (open-sided or closed) is versatile and familiar, its shortest length is often too long for comfortable manipulation of the newer, pliable, flexible hysteroscopes. The Greenberg speculum is a modification of a Graves speculum with an open side to allow for the removal of instruments while they are still in the vagina. Whereas a standard mediumsized, open-sided Graves speculum measures 110 mm in maximum length, the Greenberg speculum measures only 74 mm. Although the difference between the speculums is only 36 mm in maximum length, this alteration can add considerable ease to placement of both flexible and rigid hysteroscopes in the office or operating room. In this study, we sought to quantify the benefit of this new device by demonstrating that this speculum brings the patient's cervix closer to the provider and reduces the length of unsupported hysteroscope shaft entering the cervical canal. METHODS: We measured the intraspeculum distance from the operator-side opening of the speculum to the external cervical os by using first a standard medium open-sided Graves speculum and then a Greenberg speculum. RESULTS: Use of the Greenberg speculum reduced the mean minimum intraspeculum distance from the extended fingertips grasping a hysteroscope to the external cervical os by an average of 28 mm or 34% compared with a Graves speculum. CONCLUSIONS: We believe this new speculum offers a subtle but distinct advantage over standard speculums for hysteroscopy.

Equipment Design↗