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Biomedical subjects

M Weitzman

Publications and source records attributed to M Weitzman.

At least 19 recordsLinked to original sources

Effectiveness of influenza vaccine for the prevention of asthma exacerbations.

BACKGROUND: There is a lack of clinical evidence that annual vaccination against influenza prevents asthma exacerbations in children. METHODS: Retrospective cohort study of 800 children with asthma, where one half did, and the other half did not receive the influenza vaccine. The two groups were compared with respect to clinic visits, emergency department (ED) visits, and hospitalisations for asthma. In multivariable analyses, adjustment was made for baseline asthma severity, prior utilisation of health services, receipt of vaccine in the previous year, and demographic variables. RESULTS: After adjusting for other variables, the vaccine group had a significantly increased risk of asthma related clinic visits and ED visits (odds ratios 3.4 and 1.9, respectively). CONCLUSION: This study failed to provide evidence that the influenza vaccine prevents paediatric asthma exacerbations.

Adolescent↗

Impact of low birth weight on early childhood asthma in the United States.

OBJECTIVE: To estimate the independent contribution of birth weight to asthma prevalence among children younger than 4 years in the United States and to compare the magnitude of its effect on asthma between African American and white children. DESIGN: Cross-sectional analysis using the 1988 National Maternal-Infant Health Survey and 1991 Longitudinal Follow-up Survey. SETTING: United States. PATIENTS: Eight thousand seventy-one subjects, selected from a randomized, systematic population-based sample and weighted to be nationally representative, who completed both initial and longitudinal follow-up surveys and reported information on asthma diagnosis. MAIN OUTCOME MEASURES: Birth weight and other sociodemographic factors linked to birth outcome were analyzed for independent association with physician-diagnosed asthma by age 3 years. RESULTS: The prevalence of asthma varied by birth weight category: 6.7% in children 2500 g or more at birth, 10.9% in children 1500 to 2499 g at birth, and 21.9% in children less than 1500 g at birth (very low birth weight [VLBW]) (P<.001). Some of the characteristics shown to be independently associated with asthma included: VLBW (odds ratio [OR], 2.9; 95% confidence interval [CI], 2.3-3.6), moderately low birth weight (OR, 1.4; 95% CI, 1.1-1.8), and African American race (OR, 1.9; 95% CI, 1.6-2.4). In stratified analyses, the independent association between VLBW and asthma in white and African American populations was: OR(white), 3.1 (95% CI, 2.2-4.3) and OR(African American), 2.5 (95% CI, 2.0-3.3). The prevalence of VLBW, however, was tripled in African American compared with white children (1.8% vs 0.6%). CONCLUSIONS: These data confirm findings of other studies that identify a strong independent association between low birth weight and asthma. For this 1988 national birth cohort, an estimated 4000 excess asthma cases were attributable to birth weight less than 2500 g. Although the strength of the independent association between VLBW and asthma was smaller in the African American population, the substantially increased prevalence of VLBW in this community may contribute to the disproportionately increased prevalence of asthma among African American children.

Adult↗

Where do adolescents get their condoms?

PURPOSE: To determine where adolescents obtain their condoms; the availability and accessibility of condoms; condom availability in relationship to different sexually transmitted disease (STD) rates; and the availability of safer sex information in places where condoms are sold. METHODS: We conducted a random digit-dialed telephone survey of 259 14-19-year-old adolescents in Monroe County, New York. Self-reported health services use, knowledge and use of confidential services, and where adolescents obtained or intended to obtain condoms were assessed. Research assistants visited all retail establishments in five areas of similar population size with gonorrhea rates from 887 to 12,427 per 100,000 adolescents to assess how available and accessible condoms were in each store. Perceived access and actual condom availability and accessibility were compared using Chi-square and Student's t-tests. RESULTS: Trained interviewers dialed 11,800 numbers in 1993, identifying 4449 (40%) households among 11,065 numbers reached successfully. Of these, 393 (8.8%) had eligible adolescents and 259 (66%) completed interviews. Most adolescents reported obtaining, or planning to obtain, condoms in stores rather than from free health care settings. Adolescents who have used condoms more often reported having obtained them without cost than having purchased them. Condoms were available at 101 (83%) of 122 stores identified. All drug stores and 75% of supermarkets sold condoms and displayed them openly. Most small grocery stores also sold condoms (92%), but were less likely to openly display them. No stores displayed or provided safer sex information. Areas with higher STD rates had more stores (p <.01), and more stores that sold condoms (p <.01). There was no difference in condom cost by area. CONCLUSIONS: Many adolescents obtain their condoms in retail stores. Condom accessibility varied by store type and area STD rate. Increasing condom visibility in private grocery stores may increase the accessibility of condoms to adolescents in areas with highest STD rates.

Adolescent↗

Rep-dependent initiation of adeno-associated virus type 2 DNA replication by a herpes simplex virus type 1 replication complex in a reconstituted system.

Productive infection by adeno-associated virus type 2 (AAV) requires coinfection with a helper virus, e.g., adenovirus or herpesviruses. In the case of adenovirus coinfection, the replication machinery of the host cell performs AAV DNA replication. In contrast, it has been proposed that the herpesvirus replication machinery might replicate AAV DNA. To investigate this question, we have attempted to reconstitute AAV DNA replication in vitro using purified herpes simplex virus type 1 (HSV-1) replication proteins. We show that the HSV-1 UL5, UL8, UL29, UL30, UL42, and UL52 gene products along with the AAV Rep68 protein are sufficient to initiate replication on duplex DNA containing the AAV origins of replication, resulting in products several hundred nucleotides in length. Initiation can occur also on templates containing only a Rep binding site and a terminal resolution site. We further demonstrate that initiation of DNA synthesis can take place with a subset of these factors: Rep68 and the UL29, UL30, and UL42 gene products. Since the HSV polymerase and its accessory factor (the products of the UL30 and UL42 genes) are unable to efficiently perform synthesis by strand displacement, it is likely that in addition to creating a hairpin primer, the AAV Rep protein also acts as a helicase for DNA synthesis. The single-strand DNA binding protein (the UL29 gene product) presumably prevents reannealing of complementary strands. These results suggest that AAV can use the HSV replication apparatus to replicate its DNA. In addition, they may provide a first step for the development of a fully reconstituted AAV replication assay.

DNA Helicases↗

Residential exposures associated with asthma in US children.

OBJECTIVE: Residential exposures are recognized risk factors for childhood asthma, but the relative contribution of specific risk factors and the overall contribution of housing to asthma in US children is unknown. The objective of this study was to identify risk factors and estimate the population attributable risk of residential exposures for doctor-diagnosed asthma for US children. METHODS: A cross-sectional survey was conducted from 1988 to 1994. Survey participants were 8257 children who were <6 years old and who participated in the Third National Health and Nutrition Examination Survey, a survey of the health and nutritional status of children and adults in the United States. The main outcome measure was doctor-diagnosed asthma, as reported by the parent. RESULTS: Six percent of children had doctor-diagnosed asthma. The prevalence of asthma was higher among boys (6.7%) than girls (5.1%) and was higher among black children (8.9%) than white children (5.2%). Risk factors for doctor-diagnosed asthma included a family history of atopy (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.5, 3.1), child's history of allergy to a pet (OR: 24.2; 95% CI: 8.4, 69.5), exposure to environmental tobacco smoke (OR: 1.8; 95% CI: 1.2-2.6), use of a gas stove or oven for heat (OR: 1.8; 95% CI: 1.02-3.2), and presence of a dog in the household (OR: 1.6; 95% CI: 1.1, 2.3). The population attributable risk of >/=1 residential exposure for doctor-diagnosed asthma in US children <6 years old was 39.2%, or an estimated 533 000 excess cases, whereas having a family history of atopy accounted for 300 000. The attributable cost of asthma as a result of residential exposures for children <6 years old was $402 million (95% CI: $296-$507 million) annually. CONCLUSIONS: The elimination of identified residential risk factors, if causally associated with asthma, would result in a 39% decline in doctor-diagnosed asthma among US children <6 years old.

Asthma↗

Promoting education, mentorship, and support for pediatric research.

Pediatricians have an important role to play in the advancement of child health research and should be encouraged and supported to pursue research activities. Education and training in child health research should be part of every level of pediatric training. Continuing education and access to research advisors should be available to practitioners and academic faculty. Recommendations to promote additional research education and support at all levels of pediatric training, from premedical to continuing medical education, as well as suggestions for means to increase support and mentorship for research activities, are outlined in this statement.

Career Choice↗

Effect of latanoprost as adjunctive therapy.

BACKGROUND: Latanoprost may be a useful adjunct in some patients receiving maximum tolerated medical therapy. We report our clinical experience with latanoprost when added to one or two other glaucoma medications. METHODS: Review of the charts of 53 patients with open-angle glaucoma whose intraocular pressure (IOP) was uncontrolled with one or two glaucoma medications and who had latanoprost added as a second or third drug. Patients whose IOP decreased by 3 mm Hg or more were considered to be responders. RESULTS: The shortest length of follow-up was 2.3 months (median 5.8 months). Latanoprost was given as a second medication to 35 patients, of whom 22 (63%) responded, with a mean IOP reduction of 6.1 mm Hg (standard deviation [SD] 2.73 mm Hg) (28.7% [SD 12.10%]). Of the 18 patients to whom latanoprost was given as a third medication, 10 (56%) responded, with a mean IOP reduction of 6.3 mm Hg (SD 3.86 mm Hg) (24.5% [SD 10.12%]). INTERPRETATION: Latanoprost provides additional IOP reduction in some patients with open-angle glaucoma when added to one or two other glaucoma medications.

Adrenergic beta-Antagonists↗

Office prenatal formula advertising and its effect on breast-feeding patterns.

OBJECTIVE: To compare the effect of formula company-produced materials about infant feeding to breast-feeding promotion materials without formula advertising on breast-feeding initiation and duration. METHODS: Five hundred forty-seven pregnant women were randomized to receive either formula company (commercial; n = 277) or specially designed (research; n = 270) educational packs about infant feeding at their first prenatal visit. Feeding method was determined at delivery. Breast-feeding duration of the 294 women who chose to breast-feed was ascertained at 2, 6, 12, and 24 weeks. Survival analyses were used to evaluate continuous outcomes, and chi2 and logistic regression analyses were used to evaluate discrete outcomes. RESULTS: Breast-feeding initiation (relative risk [RR] 0.93, 95% confidence interval [CI] 0.61, 1.43) and duration after 2 weeks (hazard ratio 1.19, 95% CI 0.86, 1.64) were not affected. Women in the commercial group were more likely to cease breast-feeding before hospital discharge (RR 5.80, 95% CI 1.25, 54.01) and before 2 weeks (adjusted odds ratio [OR] 1.91, 95% CI 1.02, 3.55). In subgroup analyses, women with uncertain goals for breast-feeding or goals of 12 weeks or less experienced shortened exclusive (hazard ratio 1.53, 95% CI 1.06, 2.21), full (hazard ratio 1.70, 95% CI 1.18, 2.48), and overall (hazard ratio 1.75, 95% CI 1.16, 2.64) breast-feeding duration when exposed to the commercial intervention. CONCLUSION: Although breast-feeding initiation and long-term duration were not affected, exposure to formula promotion materials increased significantly breast-feeding cessation in the first 2 weeks. Additionally, among women with uncertain goals or breast-feeding goals of 12 weeks or less, exclusive, full, and overall breast-feeding duration were shortened. Educational materials about infant feeding should support unequivocally breast-feeding as optimal nutrition for infants; formula promotion products should be eliminated from prenatal settings.

Adult↗

Risk factors for pediatric asthma. Contributions of poverty, race, and urban residence.

The Child Health Supplement to the 1988 National Health Interview Survey was used to examine parent-reported current asthma among a nationally representative sample of 17,110 children zero to 17 yr of age. Numerous demographic variables were analyzed for independent associations with asthma using modified stepwise logistic regression, with models including specific combinations of risk factors. Black children had higher rates of asthma than did white children in unadjusted analyses, but after controlling for multiple factors, black race was not a significant correlate of asthma (adjusted odds ratio = 0.87, 95% CI = 0.63 to 1.21). Compared with nonurban white children, urban children, both black and white, were at significantly increased risk of asthma: urban and black (adjusted OR = 1.45, 95% CI = 1.14 to 1.86), urban and white (adjusted OR = 1.22, 95% CI = 1.01 to 1.48), whereas nonurban black children were not: nonurban and black (adjusted OR = 1.15, 95% CI = 0.83 to 1.61). Similarly, compared with nonurban, nonpoor children, urban and poor (adjusted OR = 1.44, 95% CI = 1.05 to 1.95), urban and nonpoor (adjusted OR = 1.22, 95% CI = 1.004 to 1.48), urban children, both poor and nonpoor, were at significantly increased risk of asthma, whereas nonurban poor children were not: nonurban and poor (adjusted OR = 1.03, 95% CI = 0.72 to 1.48). These results suggest that the higher prevalence of asthma among black children is not due to race or to low income per se, and that all children living in an urban setting are at increased risk for asthma.

Adolescent↗

Why screen newborns for cocaine: service patterns and social outcomes at age one year.

OBJECTIVE: To compare baseline characteristics, service provision, and child placement for infants exposed to cocaine in utero based on postnatal screening results. METHODS: We studied a retrospective cohort of 40 consecutive drug-exposed, but seemingly healthy term infants who underwent urine drug screening in the newborn nursery of a community hospital. Using clinical and service agency data, two cocaine-exposed cohorts were compared (a) screen-positive at birth (n = 22) versus (b) screen-negative at birth (n = 18). RESULTS: Both cocaine-exposed groups had similar infant birth weights, levels of paternal involvement, maternal ages, gravidity, parity, and lengths of gestation. Mothers in both groups had similar histories of prostitution, poor home environment, drug use, and prenatal drug rehabilitation. Mothers of screen-positive infants were more likely than mothers of screen-negative infants to have other children in foster care (27% vs. 6%, p = .07), to have experienced previous interventions by child protective services (CPS) (55% vs. 17%, p < .01), to have had no prenatal care (32% vs. 6%, p = .09), and fewer prenatal visits (4.7 vs. 8.6, p = .02). Compared to screen-negative infants, more screen-positive infants were referred to a high-risk infant tracking program (91% vs. 6%), referred to CPS (100% vs. 33%), placed outside the mother's home (50% vs. 22%), and had their mothers referred to drug rehabilitation (36% vs. 11%), (p < .01 for each). By 1 year of age, support services differed little between exposed cohorts. However, 6 of 22 screen-positive infants were in foster care and 3 were placed for adoption, while only 1 of the 18 screen-negative infants was in foster care and only 1 had been placed for adoption. There were no services available in this community to provide coordinated or comprehensive services or drug treatment specific to the needs of drug using mothers and drug exposed infants. CONCLUSIONS: Despite similarities between cocaine-exposed infants cared for in a normal newborn setting (with and without positive urine drug screens at birth), differences in referral services were noted. More striking than these differences was that services for families with drug-exposed infants are inadequate to even meet the needs of those families in our setting deemed to be at highest risk. Neonatal drug screening needs to be paired with effective services.

Cocaine-Related Disorders↗

Primary prevention of childhood lead exposure: A randomized trial of dust control.

BACKGROUND: Dust control is recommended as one of the primary strategies to prevent or control children's exposure to residential lead hazards, but the effect of dust control on children's blood lead levels is poorly understood. OBJECTIVE: To determine the effectiveness of dust control in preventing children's exposure to lead, as measured by blood lead levels, during their peak age of susceptibility. DESIGN: A randomized, controlled trial. SETTING: Rochester, NY. PARTICIPANTS: A total of 275 urban children were randomized at 6 months of age, of whom 246 (90%) were available for the 24-month-old follow-up visit. INTERVENTIONS: Children and their families were randomly assigned to an intervention group (n = 140), which received cleaning equipment and up to eight visits by a dust control advisor, or a control group (n = 135). OUTCOME MEASURES: Geometric mean blood lead levels and prevalence of elevated blood lead levels (ie, >10 microg/dL, 15 microg/dL, and 20 microg/dL). RESULTS: At baseline, children's geometric mean blood lead levels were 2.9 microg/dL (95% confidence interval [CI] = 2.7, 3.1); there were no significant differences in characteristics or lead exposure by group assignment, with the exception of water lead levels. For children in the intervention group, the mean number of visits by a dust control advisor during the 18-month study period was 6.2; 51 (36%) had 4 to 7 visits, and 69 (49%) had 8 visits. At 24 months of age, the geometric mean blood lead was 7.3 microg/dL (95% CI = 6.6, 8.2) for the intervention group and 7.8 microg/dL (95% CI = 6.9, 8. 7) for the control group. The percentage of children with a 24-month blood lead >/=10 microg/dL, >/=15 microg/dL, and >/=20 microg/dL was 31% versus 36%, 12% versus 14%, and 5% versus 7% in the intervention and control groups, respectively. CONCLUSIONS: We conclude that dust control, as performed by families and in the absence of lead hazard controls to reduce ongoing contamination from lead-based paint, is not effective in the primary prevention of childhood lead exposure.

Dust↗

Black and white middle class children who have private health insurance in the United States.

OBJECTIVE: To compare the health, behavior and school problems, and use of medical, mental health, and special education services of privately insured, middle class black and white children in the United States. DESIGN/METHODS: Analyses of the Child Health Supplement to the 1988 National Health Interview Survey, with a nationally representative sample of 17 110 children age 0-17 years. RESULTS: Privately insured middle class black children had fewer chronic health conditions, but were less likely to be reported to be in excellent health (46.2% vs 57.3%) and more likely to have had asthma (8.5% vs 5.8%) or to have been of low birth weight (10.7% vs 5.6%). There were no differences in rates of having a usual source of routine care (92.2% vs 93.8%) or of being up to date with well-child care (79.3% vs 78.2%), but black children made fewer physician visits, were less likely to use physicians' offices, were more likely to lack continuity of care, and were twice as likely to use emergency departments. These differences in use of medical services persisted in multivariate analyses and analyses restricted to more affluent children. Despite similar rates of behavior problems, black children were more likely to repeat a grade (20.0% vs 12.3%) and to have been suspended from school (11.3% vs 5.0%). Although significantly fewer black middle class children received mental health or special education services in bivariate analyses, no differences in receipt of these services were noted in multivariate analyses. All differences reported were significant. CONCLUSIONS: Among middle class children in the United States, black and white children have similar rates of health and behavior problems, but black children experience substantially increased rates of asthma, low birth weight, and school difficulties. Although not differing in the receipt of mental health or special education services, middle class black children, even in the presence of private health insurance, have markedly different sources and patterns of use of medical services.

Adolescent↗

Lead screening practices of pediatric residents.

OBJECTIVES: As part of their training, pediatric residents provide primary care services to young children, including youngsters who may have elevated blood lead levels. We set out to (1) determine the percentage of pediatric residents who screen children for elevated blood lead levels according to the guidelines of the Centers for Disease Control and Prevention and the American Academy of Pediatrics; (2) assess the likelihood of lead screening by residents based on demographic and practice-setting characteristics; and (3) compare the attitudes of residents who report that they are universal screeners, selective screeners, or nonscreeners. DESIGN: Confidential, cross-sectional survey of a nationally representative sample of pediatric residents conducted as part of the American Academy of Pediatrics 28th Periodic Survey of Fellows. SUBJECTS: One hundred forty-three responding pediatric residents (51% response rate). RESULTS: Seventy-five percent of pediatric residents reported screening all patients aged 9 to 36 months for elevated blood lead levels, 21% reported screening some, and 4% reported screening none. Pediatric residents who cared for patients in urban settings were more likely to report screening patients for elevated blood lead levels than were pediatric residents who cared for patients in suburban or rural settings (100% vs 73%; P < .001) and pediatric residents in the Northeast were more likely to report screening universally than were residents in the rest of the country (93% vs 63%; P < .001). Overall, pediatric residents who reported screening patients universally were more likely to believe that the benefits of screening outweigh the costs than were residents who reported screening patients selectively (67% vs 17%; P < .001). CONCLUSIONS: Most pediatric residents reported that they screened patients for elevated blood lead levels, either universally or selectively. Nevertheless, the screening practices of pediatric resident and their opinions concerning the relative benefits and costs of lead screening largely reflect the areas of the country and the practice settings in which they had their primary care experiences.

Adult↗

The effect of aqueous humor suppressants on intravitreal gas bubble duration in rabbits.

PURPOSE: To evaluate the effect of topical aqueous humor suppressants on the absorption of intravitreal perfluorocarbon gases. METHODS: Sulfur hexafluoride or perfluoropropane was injected intravitreally in five rabbits. Time to gas disappearance was measured in eyes treated with topical aqueous humor suppressants and in those not treated. RESULTS: The mean time (+/- SD) to disappearance of 0.4 cc of sulfur hexafluoride was 5.6 +/- 0.9 days, which was prolonged by 43% to 8.0 +/- 0.7 days with topical aqueous humor suppressants (P = .009). The mean time (+/- SD) to disappearance of 0.2 cc of perfluoropropane was 18.4 +/- 1.9 days, which was prolonged by 55% to 28.6 +/- 2.7 days with topical aqueous humor suppressants (P = .009). CONCLUSION: Aqueous suppressants prolong sulfur hexafluoride and perfluoropropane intravitreal gas bubble duration in rabbits.

Absorption↗

Acquired pit of the optic nerve: a risk factor for progression of glaucoma.

PURPOSE: To examine acquired pit of the optic nerve as a risk factor for progression of glaucoma. METHODS: In a retrospective longitudinal study, 25 open-angle glaucoma patients with acquired pit of the optic nerve were compared with a group of 24 open-angle glaucoma patients without acquired pit of the optic nerve. The patients were matched for age, mean intraocular pressure, baseline ratio of neuroretinal rim area to disk area, visual field damage, and duration of follow-up. Serial optic disk photographs and visual fields of both groups were evaluated by three independent observers for glaucomatous progression. RESULTS: Of 46 acquired pits of the optic nerve in 37 eyes of 25 patients, 36 pits were located inferiorly (76%) and 11 superiorly (24%; P < .001). Progression of optic disk damage occurred in 16 patients (64%) in the group with acquired pit and in three patients (12.5%) in the group without acquired pit (P < .001). Progression of visual field loss occurred in 14 patients (56%) in the group with acquired pit and in six (25%) in the group without pit (P=.04). Bilateral acquired pit of the optic nerve was present in 12 patients (48%). Disk hemorrhages were observed more frequently in the group with acquired pit (10 eyes, 40%) compared with the group without pit (two eyes, 8%; P=.02). CONCLUSION: Among patients with glaucoma, patients with acquired pit of the optic nerve represent a subgroup who are at increased risk for progressive optic disk damage and visual field loss.

Adult↗