Is household antibiotic use a risk factor for antibiotic-resistant pneumococcal infection?

We used microbiology and pharmacy data from health-maintenance organizations to determine whether antibiotic use by a household member increases the risk of penicillin-non-susceptible pneumococcal disease. Though it has been well established that an individual's antibiotic use increases one's risk of antibiotic-resistant infection, it is unclear whether the risk is increased if a member of one's household is exposed to antibiotics. We therefore conducted a case-control study of patients enrolled in health maintenance organizations in Western Washington and Northern California. Cases were defined as individuals with penicillin-non-susceptible pneumococcal infection; controls were individuals with penicillin-susceptible pneumococcal infection. Socioeconomic variables were obtained by linking addresses with 1997 census block group data. One-hundred and thirty-four cases were compared with 798 controls. Individual antibiotic use prior to diagnosis increased the odds of penicillin non-susceptibility, with the strongest effect seen for beta-lactam use within 2 months (OR 1.8, 95% CI 1.2, 2.8). When household antibiotic use by persons other than the patient were considered, at 4 months prior to diagnosis there was a trend towards an association between penicillin non-susceptibility and beta-lactam antibiotic use, and a possible association in a small subgroup of patients with eye and ear isolates. However, no significant overall pattern of association was seen. We conclude that though antibiotic use of any kind within 2 months prior to diagnosis is associated with an increased risk of penicillin-non-susceptible pneumococcal disease, there is no significant overall pattern of association between household antibiotic use and penicillin-non-susceptible pneumococcal infection.

Measles vaccination and inflammatory bowel disease: controversy laid to rest?

The increasing incidence of Crohn's disease has lead to speculation about changes in exposures to environmental or infectious agents. Considerable attention has focused on the role of measles infection and/or vaccination in the pathogenesis of Crohn's disease and ulcerative colitis. Current evidence regarding the association between measles vaccination and inflammatory bowel disease (IBD) comprises analytic epidemiological studies, a case-series report and ecological studies. The first of these, a 1995 cohort study, found an association between measles vaccination and Crohn's disease and ulcerative colitis, but was widely questioned on methodological grounds. This was followed by a 1997 case-control study showing no association between measles vaccination and IBD. In 1998, public concern was rekindled by a report of 12 children with nonspecific colitis, ileal-lymphoid-nodular hyperplasia, and developmental disorders largely attributed to measles-mumps-rubella vaccine, but the nature of the report limited its scientific conclusions. Two additional studies, one case-control and one cohort, then followed and neither found an association with measles vaccination. Of the several ecological studies of measles vaccine coverage or measles schedule changes, none found an association with rates of IBD. The role of measles infection in IBD has been examined more extensively with studies of in utero measles exposure, measles infection early in life, and laboratory based investigations. An initial report of high rates of Crohn's disease among pregnancies affected by measles infection was followed by negative studies. Numerous case-control and ecological studies of children with measles infections early in life have also had discordant findings. Of three recent cohort studies, two showed no relationship between infection with early measles exposure and risk for IBD, while one found an approximate 3-fold elevation in risk. Laboratory investigations into persistent measles infection and IBD have been contentious. While some investigators have claimed to find persistent measles infection among patients with IBD, others, using highly sensitive polymerase chain reaction techniques, have not been able to replicate the findings. Recent controversy has centred on whether there is any evidence for molecular mimicry in the pathogenesis of IBD. In summary, available evidence does not support an association between measles-containing vaccines and risk of IBD, nor between measles infection and IBD. While further research is necessary into the causal factors underlying Crohn's disease and ulcerative colitis, continued public education efforts are needed to reassure the public about vaccine safety and to prevent declines in vaccine coverage.

Vertebrate hairy and Enhancer of split related proteins: transcriptional repressors regulating cellular differentiation and embryonic patterning

The basic-helix-loop-helix (bHLH) proteins are a superfamily of DNA-binding transcription factors that regulate numerous biological processes in both invertebrates and vertebrates. One family of bHLH transcriptional repressors is related to the Drosophila hairy and Enhancer-of-split proteins. These repressors contain a tandem arrangement of the bHLH domain and an adjacent sequence known as the Orange domain, so we refer to these proteins as bHLH-Orange or bHLH-O proteins. Phylogenetic analysis reveals the existence of four bHLH-O subfamilies, with distinct, evolutionarily conserved features. A principal function of bHLH-O proteins is to bind to specific DNA sequences and recruit transcriptional corepressors to inhibit target gene expression. However, it is likely that bHLH-O proteins repress transcription by additional mechanisms as well. Many vertebrate bHLH-O proteins are effectors of the Notch signaling pathway, and bHLH-O proteins are involved in regulating neurogenesis, vasculogenesis, mesoderm segmentation, myogenesis, and T lymphocyte development. In this review, we discuss mechanisms of action and biological roles for the vertebrate bHLH-O proteins, as well as some of the unresolved questions about the functions and regulation of these proteins during development and in human disease.

Presenilin-1 and memories of the forebrain

In this issue of Neuron, report that forebrain-specific Presenilin-1 conditional knockout mice show defects in enrichment-induced neurogenesis in the dentate gyrus. This defect in neurogenesis is associated with enhanced fear memory of contextual cues when animals are subjected to enrichment between training and testing. The authors suggest that neurogenesis in the adult dentate gyrus may serve to clear out old memory traces from the hippocampus, thus leaving the hippocampus available for new memory processing.

Childhood vaccinations, vaccination timing, and risk of type 1 diabetes mellitus

OBJECTIVES

To evaluate suggested associations between childhood vaccinations, particularly against hepatitis B and Haemophilus influenzae type b, and risk of developing type 1 diabetes; and to determine whether timing of vaccination influences risk.

METHODS

We conducted a case-control study within 4 health maintenance organizations (HMOs) that participate in the Vaccine Safety Datalink project of the Centers for Disease Control and Prevention. Study eligibility was restricted to children who met the following criteria: 1) born during 1988 through 1997; 2) HMO member since birth; 3) continuously enrolled for first 6 months of life; and 4) at least 12 months of HMO membership before diabetes incidence date (or index date for controls) unless incidence date was before 12 months of age. All 4 HMOs maintain registries of their members who have diabetes, and we used the registries to identify potential cases of diabetes. We conducted chart reviews to verify that potential cases met the World Health Organization epidemiologic case definition for type 1 diabetes mellitus (ie, a physician's diagnosis of diabetes plus treatment with daily insulin injections). We defined the incidence date of diabetes as the first date that the child received a diagnosis of diabetes. We attempted to match 3 controls to each case. Controls had the same eligibility criteria as cases and were matched to individual cases on HMO, sex, date of birth (within 7 days), and length of health plan enrollment (up to the incidence or index date). The index date for controls was defined as the incidence date of the case to which the control was matched. Chart abstraction was performed by trained chart abstractors using standardized forms. In addition to complete vaccination histories, the chart abstraction forms for both cases and controls included information on sociodemographic characteristics, selected medical conditions, history of breastfeeding, and family medical history. We used conditional logistic regression to estimate the odds ratio (OR) of diabetes associated with vaccination, with vaccine exposure defined as before the diabetes incidence date (or index date for controls).

RESULTS

Two hundred fifty-two confirmed cases of diabetes and 768 matched controls met the study eligibility criteria. The OR (95% confidence interval) for the association with type 1 diabetes was 0.28 (0.07-1.06) for whole cell pertussis vaccine (predominantly in combination as diphtheria, tetanus toxoids and pertussis vaccine), 1.36 (0.70-2.63) for measles-mumps-rubella, 1.14 (0.51-2.57) for Haemophilus influenzae type b, 0.81 (0.52-1.27) for hepatitis B vaccine, 1.16 (0.72-1.89) for varicella vaccine, and 0.92 (0.53-1.57) for acellular pertussis-containing vaccines. Compared with children who had not received hepatitis B vaccine, the OR of diabetes was 0.51 (0.23-1.15) for children vaccinated at birth and 0.86 (0.54-1.35) for those first vaccinated against hepatitis B at 2 months of age or later. Race and ethnicity and family history of diabetes were independently associated with risk of type 1 diabetes, but adjustment for these factors did not materially alter the ORs for any of the vaccines.

CONCLUSIONS

In this large, population-based, case-control study, we did not find an increased risk of type 1 diabetes associated with any of the routinely recommended childhood vaccines. Our study adds to previous research by providing data on newer vaccines, including hepatitis B, acellular pertussis, and varicella vaccines. For the older vaccines, our results are generally in agreement with previous studies in not finding any increased risks. Ours is the first epidemiologic study to evaluate the possibility that timing of vaccination is related to risk of clinical diabetes in children. Our results on hepatitis B vaccine do not support the hypothesis; risk of type 1 diabetes was not different between infants vaccinated at birth and those who received their first vaccination later in life. The results of our study and the preponderance of epidemiologic evidence do not support an association between any of the recommended childhood vaccines and an increased risk of type 1 diabetes. Suggestions that diabetes risk in humans may be altered by changes in the timing of vaccinations also are unfounded.

Biopharmaceutical statistics in a pharmaceutical regulated environment: past, present, and future

The practice of statistics in the pharmaceutical industry has changed markedly over the last 25 years. This paper examines the evolution of clinical trial statistics in relationship to advances in statistical methodology and computational power as well as the changing regulatory environment. The current role of the biopharmaceutical statistician is assessed along with the drivers for future change.

Universal newborn hearing screening: summary of evidence

CONTEXT

Each year, approximately 5000 infants are born in the United States with moderate-to-profound, bilateral permanent hearing loss (PHL). Universal newborn hearing screening (UNHS) has been proposed as a means to speed diagnosis and treatment and thereby improve language outcomes in these children.

OBJECTIVES

To identify strengths, weaknesses, and gaps in the evidence supporting UNHS and to compare the additional benefits and harms of UNHS with those of selective screening of high-risk newborns.

DATA SOURCES

We searched the MEDLINE, CINAHL, and PsychINFO databases for relevant articles published from 1994 to August 2001, using terms for hearing disorders, infants or newborns, screening, and relevant treatments. We contacted experts and reviewed reference lists to identify additional articles, including those published before 1994.

STUDY SELECTION

We included controlled and observational studies of (1) the accuracy, yield, and harms of screening using otoacoustic emissions (OAEs), auditory brainstem response (ABR), or both in the general newborn population and (2) the effects of screening or early identification and treatment on language outcomes. Of an original 340 articles identified, 19 articles, including 1 controlled trial, met these inclusion criteria.

DATA EXTRACTION

Data on population, test performance, outcomes, and methodological quality were extracted by 2 authors (D.C.T., H.M.) using prespecified criteria developed by the US Preventive Services Task Force. We queried authors when information needed to assess study quality was missing.

DATA SYNTHESIS

Good-quality studies show that from 2041 to 2794 low-risk and 86 to 208 high-risk newborns were screened to find 1 case of moderate-to-profound PHL. The best estimate of positive predictive value was 6.7%. Six percent to 15% of infants who are missed by the screening tests are subsequently diagnosed with bilateral PHL. In a trial of UNHS vs clinical screening at age 8 months, UNHS increased the proportion of infants with moderate-to-severe hearing loss diagnosed by age 10 months (57% vs 14%) but did not reduce the rate of diagnosis after age 18 months. No good-quality controlled study has compared UNHS with selective screening of high-risk newborns. In fair- to poor-quality cohort studies, intervention before age 6 months was associated with improved language and communication skills by ages 2 to 5 years. These studies had unclear criteria for selecting subjects, and none compared an inception cohort of low-risk newborns identified by screening with those identified in usual care, making it impossible to exclude selection bias as an explanation for the results. In a mathematical model based on the literature review, we estimated that extending screening to low-risk infants would detect 1 additional case before age 10 months for every 1441 low-risk infants screened, and result in treatment before 10 months of 1 additional case for every 2401 low-risk infants screened. With UNHS, 254 newborns would be referred for audiological evaluation because of false-positive second-stage screening test results vs 48 for selective screening.

CONCLUSIONS

Modern screening tests for hearing impairment can improve identification of newborns with PHL, but the efficacy of UNHS to improve long-term language outcomes remains uncertain.

P[Switch], a system for spatial and temporal control of gene expression in Drosophila melanogaster

We have developed a method for turning on and off the expression of transgenes within Drosophila in both time and space. Two different enhancer detector elements carrying an RU486-inducible form of the yeast transcription factor GAL4 were constructed and used to generate enhancer detector lines. These lines were screened for RU486-inducible reporter gene expression in the adult head. We identified lines that exhibit inducible expression in many cell and tissue types, verifying that the elements respond to nearby enhancers. No expression was detected in the absence of the ligand. The P[Switch1] element responded to genomic enhancers less efficiently than P[Switch2] but produced more specific patterns of expression. Two P[Switch] lines were used to ablate fat body tissue in adult females through the induced expression of diphtheria toxin. These females were sterile, which correlates with fat body loss, and they died prematurely.

Molecular targets of vertebrate segmentation: two mechanisms control segmental expression of Xenopus hairy2 during somite formation

Vertebrate hairy genes are expressed in patterns thought to be readouts of a "segmentation clock" in the presomitic mesoderm. Here we use transgenic Xenopus embryos to show that two types of regulatory elements are required to reconstitute the segmental pattern of Xenopus hairy2. The first is a promoter element containing two binding sites for Xenopus Su(H), a transcriptional activator of Notch target genes. The second is a short sequence in the hairy2 3' untranslated region (UTR), which most likely functions posttranscriptionally to modulate hairy2 RNA levels. 3' UTRs of other hairy-related, segmentally expressed genes can substitute for that of hairy2. Our results demonstrate a novel mechanism regulating the segmental patterns of Notch target genes and suggest that vertebrate segmentation requires the intersection of two regulatory pathways.

Cognitive deficits associated with a recently reported familial neurodegenerative disease: familial encephalopathy with neuroserpin inclusion bodies

BACKGROUND

We recently discovered an autosomal dominant disease causing a progressive dementia. The disease is caused by a point mutation in the gene coding for the serine protease inhibitor (ie, serpin) neuroserpin. The mutation results in an unstable neuroserpin protein that readily aggregates into intraneuronal inclusions that we identify as Collins bodies. The bodies are distributed throughout the cerebral hemispheres but are significantly more numerous in the cortex and the substantia nigra. We have named the disease familial encephalopathy with neuroserpin inclusion bodies (FENIB).

OBJECTIVES

To describe the cognitive and neurophysiological changes exhibited by individuals with FENIB and to correlate the phenotypic expression of the disease with the neuropathological findings.

DESIGN

Multiple case studies using neuropsychological assessment, electroencephalography (EEG), magnetic resonance imaging (MRI), and single-photon emission computed tomographic (SPECT) studies of family members were performed. Using these measures, we also compared family members in whom the mutation is present with family members in whom the mutation was absent to control for nonspecific familial factors.

SUBJECTS

Nine individuals (5 women, aged 31-64 years; 4 men, aged 43-67 years) from 2 generations of family members related to the first reliably identified individual with symptoms of this disease. Symptoms, by self-report and reports of other family members, ranged from asymptomatic to severe dementia. Six of the 9 individuals carried the disease mutation.

RESULTS

All subjects with the mutation demonstrated some cognitive changes, with the greatest demonstrated by subjects older than 40 years. The changes included restricted attention, concentration, and response regulation functions, reduced controlled oral fluency (word-list generation), and restricted visuospatial organization. In general, recall memory was not as affected as other cognitive domains. The most severely affected subject demonstrated global dementia with prominent frontal lobe features. Findings on SPECT showed anomalies limited to frontal areas in the less affected subjects and more global, patchy areas of hypoperfusion in the more severely affected subjects. The 3 oldest and most affected subjects demonstrated slowing on EEG findings. The MRI findings were noncontributory except in the 2 most severe cases, which showed global cortical atrophy.

CONCLUSIONS

Cognitive changes in mildly to moderately affected subjects were characterized by deficits in frontal and frontal-subcortical area-dependent processes. Continued progressive deterioration of cerebral functions with relative sparing of recall memory suggests a unique dementia associated with this disease.

The rotavirus vaccine's withdrawal and physicians' trust in vaccine safety mechanisms

OBJECTIVE

To determine how the withdrawal from the market of the rotavirus vaccine has affected physicians' trust in vaccine safety mechanisms, future adherence to vaccine recommendations, and willingness to use a new rotavirus vaccine.

DESIGN

National survey mailed to 1228 randomly selected pediatricians and family physicians.

MAIN OUTCOME MEASURES

Confidence in vaccine safety mechanisms was defined by agreement with the statements that the system for determining vaccine safety before a vaccine is licensed works well and that the system for monitoring vaccine safety after vaccine licensure works well. Physicians who indicated that they would use a new rotavirus vaccine within 1 year of licensure and recommendation by professional organizations were classified as "early adopters." Logistic regression was used to assess the relationship between trust in vaccine safety mechanisms and future early adoption of new rotavirus vaccines.

RESULTS

Following the withdrawal of the rotavirus vaccine, 83% of respondents believed the postlicensure surveillance system works well to monitor vaccine safety, while 22% of respondents believed the prelicensure system works well to determine vaccine safety. After adjusting for physician specialty and years in practice, respondents who believed the prelicensure vaccine safety system works well were significantly more likely to be early adopters than those with less confidence in prelicensure studies (adjusted odds ratio, 2.2 [95% confidence interval, 1.3-3.6]).

CONCLUSIONS

Physicians have different levels of trust in prelicensure studies that determine vaccine safety and postlicensure surveillance systems that monitor vaccine safety. Trust in prelicensure vaccine safety evaluations may be associated with early adherence to new vaccine recommendations.

The risk of seizures after receipt of whole-cell pertussis or measles, mumps, and rubella vaccine

BACKGROUND

The administration of the diphtheria and tetanus toxoids and whole-cell pertussis (DTP) vaccine and measles, mumps, and rubella (MMR) vaccine has been associated with adverse neurologic events, including seizures. We studied the relation between these vaccinations and the risk of a first seizure, subsequent seizures, and neurodevelopmental disability in children.

METHODS

This cohort study was conducted at four large health maintenance organizations and included reviews of the medical records of children with seizures. We calculated the relative risks of febrile and nonfebrile seizures among 679,942 children after 340,386 vaccinations with DTP vaccine, 137,457 vaccinations with MMR vaccine, or no recent vaccination. Children who had febrile seizures after vaccination were followed to identify the risk of subsequent seizures and other neurologic disabilities.

RESULTS

Receipt of DTP vaccine was associated with an increased risk of febrile seizures only on the day of vaccination (adjusted relative risk, 5.70; 95 percent confidence interval, 1.98 to 16.42). Receipt of MMR vaccine was associated with an increased risk of febrile seizures 8 to 14 days after vaccination (relative risk, 2.83; 95 percent confidence interval, 1.44 to 5.55). Neither vaccination was associated with an increased risk of nonfebrile seizures. Analyses of automated data alone gave results similar to the analyses of the data from medical-record reviews. The number of febrile seizures attributable to the administration of DTP and MMR vaccines was estimated to be 6 to 9 and 25 to 34 per 100,000 children, respectively. As compared with other children with febrile seizures that were not associated with vaccination, the children who had febrile seizures after vaccination were not found to be at higher risk for subsequent seizures or neurodevelopmental disabilities.

CONCLUSIONS

There are significantly elevated risks of febrile seizures on the day of receipt of DTP vaccine and 8 to 14 days after the receipt of MMR vaccine, but these risks do not appear to be associated with any long-term, adverse consequences.

The role of Drosophila mushroom body signaling in olfactory memory

The mushroom bodies of the Drosophila brain are important for olfactory learning and memory. To investigate the requirement for mushroom body signaling during the different phases of memory processing, we transiently inactivated neurotransmission through this region of the brain by expressing a temperature-sensitive allele of the shibire dynamin guanosine triphosphatase, which is required for synaptic transmission. Inactivation of mushroom body signaling through alpha/beta neurons during different phases of memory processing revealed a requirement for mushroom body signaling during memory retrieval, but not during acquisition or consolidation.

Molecular biology and anatomy of Drosophila olfactory associative learning

Most of our current knowledge of olfactory associative learning in Drosophila comes from the behavioral and molecular analysis of mutants that fail to learn. The identities of the genes affected in these mutants implicate new signaling pathways as mediators of associative learning. The expression patterns of these genes provide insight into the neuroanatomical areas that underlie learning. In recent years, there have been great strides in understanding the molecular and neuroanatomical basis for olfaction in insects. It is now clear that much of the association between the conditioned stimuli and the unconditioned stimuli in olfactory learning occurs within mushroom bodies - third order olfactory neurons within the central brain. In this review, we discuss the nature of the behavioral tasks, the molecules, and the neuronal circuits involved in olfactory learning in Drosophila.

Reducing antibiotic use in children: a randomized trial in 12 practices

OBJECTIVE

To test whether an educational outreach intervention for families and physicians, based on the Centers for Disease Control and Prevention (CDC) principles of judicious antibiotic use, decreases antimicrobial drug prescribing for children younger than 6 years old. Setting. Twelve practices affiliated with 2 managed care organizations (MCOs) in eastern Massachusetts and northwest Washington State. Patients. All enrolled children younger than 6 years old.

METHODS

Practices stratified by MCO and size were randomized to intervention or control groups. The intervention included 2 meetings of the practice with a physician peer leader, using CDC-endorsed summaries of judicious prescribing recommendations; feedback on previous prescribing rates were also provided. Parents were mailed a CDC brochure on antibiotic use, and supporting materials were displayed in waiting rooms. Automated enrollment, ambulatory visit, and pharmacy claims were used to determine rates of antibiotic courses dispensed (antibiotics/person-year) during baseline (1996-1997) and intervention (1997-1998) years. The primary analysis (for children 3 to <36 months and 36 to <72 months) assessed the impact of the intervention among children during the intervention year, controlling for covariates including patient age and baseline prescription rate. Confirmatory analyses at the practice level were also performed.

RESULTS

The practices cared for 14 468 and 13 460 children in the 2 study years, respectively; 8815 children contributed data in both years. Sixty-two percent of antibiotic courses were dispensed for otitis media, 6.5% for pharyngitis, 6.3% for sinusitis, and 9.2% for colds and bronchitis. Antibiotic dispensing for children 3 to <36 months old decreased 0.41 antibiotics per person-year (18.6%) in intervention compared with 0.33 (11.5%) in control practices. Among children 36 to <72 months old, the rate decreased by 0.21 antibiotics per person-year (15%) in intervention and 0.17 (9.8%) in control practices. Multivariate analysis showed an adjusted intervention effect of 16% in the younger and 12% in the older age groups. The direction and approximate magnitude of effect were confirmed in practice-level analyses.

CONCLUSIONS

A limited simultaneous educational outreach intervention for parents and providers reduced antibiotic use among children in primary care practices, even in the setting of substantial secular trends toward decreased prescribing. Future efforts to promote judicious prescribing should continue to build on growing public awareness of antibiotic overuse.

Drosophila fasciclinII is required for the formation of odor memories and for normal sensitivity to alcohol

Drosophila fasciclinII (fasII) mutants perform poorly after olfactory conditioning due to a defect in encoding, stabilizing, or retrieving short-term memories. Performance was rescued by inducing the expression of a normal transgene just before training and immediate testing. Induction after training but before testing failed to rescue performance, showing that Fas II does not have an exclusive role in memory retrieval processes. The stability of odor memories in fasII mutants are indistinguishable from control animals when initial performance is normalized. Like several other mutants deficient in odor learning, fasII mutants exhibit a heightened sensitivity to ethanol vapors. A combination of behavioral and genetic strategies have therefore revealed a role for Fas II in the molecular operations of encoding short-term odor memories and conferring alcohol sensitivity. The preferential expression of Fas II in the axons of mushroom body neurons furthermore suggests that short-term odor memories are formed in these neurites.

Mushroom bodies, Ca(2+) oscillations, and the memory gene amnesiac

The memory of odors in Drosophila is mediated by mushroom body neurons. Memory is formed, in part, by a modulation of the physiology of these neurons brought about by neuropeptides that are encoded by the amnesiac gene and released from peptidergic neurons that innervate mushroom body neurons. Slow and spontaneous oscillations of calcium levels are elevated in the mushroom body neurons of amnesiac mutants and may contribute to memory consolidation.

Ethnicity delineates different genetic pathways in malignant glioma

In the United States and the San Francisco Bay Area, whites are nearly twice as likely as non-whites to develop brain cancer. To test whether prevalence and types of alterations in the p53 pathway in brain tumor development may explain some of this difference in risk, we have analyzed the p53 status of astrocytic gliomas from a population-based sample of cases within our San Francisco Bay Area Adult Glioma Study. We identified mutations in exons 5-8 of p53 using DNA extracted from formalin-fixed paraffin-embedded tissue blocks from 146 whites and 26 non-whites with astrocytic glioma by PCR-single-strand conformation polymorphism and direct sequencing. Tumor P53 protein (TP53) immunohistochemistry (IHC) available for 164 of these cases showed that tumors from 50% (13 of 26) of non-whites and 32% (44 of 138) of whites contained intense IHC staining for TP53, indicating persistence of TP53 protein. Irrespective of IHC status, tumors from 42% (11 of 26) of non-whites versus 13% (19 of 146) of whites contained p53 mutations (age/gender-adjusted odds ratio, 5.7; 95% confidence interval, 2.2-15.1; P = 0.0004). Patients with p53 mutation-positive tumors were also significantly younger than patients with mutation-negative tumors and somewhat more likely to be female. A higher proportion of tumors from non-whites than from whites had transition mutations, but there were similar proportions of transversion mutations in tumors from whites and non-whites. Whites and non-whites also had similar proportions of tumors with p53 mutations that stained intensely for TP53 (78 and 82%, respectively). Because whites have higher risk for glioma than non-whites in this population, that the gliomas from whites were less likely than those from non-whites to have p53 mutation suggests that whites may be more likely than non-whites to be at risk for the more common type of astrocytic gliomas, which do not contain p53 mutations.

Variation in clinician recommendations for multiple injections during adoption of inactivated polio vaccine

OBJECTIVES

To describe variation in clinician recommendations for multiple injections during the adoption of inactivated poliovirus vaccine (IPV) in 2 large health maintenance organizations (HMOs), and to test the hypothesis that variation in recommendations would be associated with variation in immunization coverage rates.

DESIGN

Cross-sectional study based on a survey of clinician practices 1 year after IPV was recommended and computerized immunization data from these clinicians' patients. STUDY SETTINGS: Two large West Coast HMOs: Kaiser Permanente in Northern California and Group Health Cooperative of Puget Sound.

OUTCOME MEASURES

Immunization status of 8-month-olds and 24-month-olds cared for by the clinicians during the study.

RESULTS

More clinicians at Group Health (82%), where a central guideline was issued, had adopted the IPV/oral poliovirus vaccine (OPV) sequential schedule than at Kaiser (65%), where no central guideline was issued. Clinicians at both HMOs said that if multiple injections fell due at a visit and they elected to defer some vaccines, they would be most likely to defer the hepatitis B vaccine (HBV) for infants (40%). At Kaiser, IPV users were more likely than OPV users to recommend the first HBV at birth (64% vs 28%) or if they did not, to defer the third HBV to 8 months or later (62% vs 39%). In multivariate analyses, patients whose clinicians used IPV were as likely to be fully immunized at 8 months old as those whose clinicians used all OPV. At Kaiser, where there was variability in the maximum number of injections clinicians recommended at infant visits, providers who routinely recommended 3 or 4 injections at a visit had similar immunization coverage rates as those who recommended 1 or 2. At both HMOs, clinicians who strongly recommended all possible injections at a visit had higher immunization coverage rates at 8 months than those who offered parents the choice of deferring some vaccines to a subsequent visit (at Kaiser, odds ratio [OR]: 1.2; 95% confidence interval [CI]: 1.0-1.5; at Group Health, OR: 1.8; 95% CI: 1.1-2.8).

CONCLUSIONS

Neither IPV adoption nor the use of multiple injections at infant visits were associated with reductions in immunization coverage. However, at the HMO without centralized immunization guidelines, IPV adoption was associated with changes in the timing of the first and third HBV. Clinical policymakers should continue to monitor practice variation as future vaccines are added to the infant immunization schedule.

Impact of the change in polio vaccination schedule on immunization coverage rates: a study in two large health maintenance organizations

OBJECTIVE

In January 1997, one of the most significant changes to United States vaccine policy occurred when polio immunization guidelines changed to recommend a schedule containing inactivated polio vaccine (IPV). There were concerns that parent or physician reluctance to accept IPV into the routine childhood immunization schedule would lead to lowered coverage. We determined whether adoption of an IPV schedule had a negative impact on immunization coverage.

DESIGN

A cohort study of 2 large health maintenance organizations (HMOs), Group Health Cooperative and Kaiser Permanente Northern California, was conducted. For analysis at 12 months of age, children who were born between October 1, 1996, and December 31, 1997, and were commercially insured and covered by Medicaid were continuously enrolled; for analysis at 24 months of age, children who were born between October 1, 1996, and June 30, 1997, and were commercially insured and covered by Medicaid were continuously enrolled. The 3 measures of immunization status at 12 and 24 months of age were up-to-date status, cumulative time spent up-to-date, and the number of missed opportunity visits.

RESULTS

At both HMOs, children who received IPV were as likely to be up to date at 12 months as were children who received oral poliovirus vaccine (OPV), whereas at Group Health, children who received IPV were slightly more likely to be up to date at 24 months (relative risk: 1.12; 95% confidence interval [CI]: 1.05, 1.19). These findings were consistent for children who were covered by Medicaid. At Kaiser Permanente, children who received IPV spent ~3 fewer days up to date in the first year of life, but this difference did not persist at 2 years of age. At Group Health, children who received IPV were no different from those who received OPV in terms of days spent up to date by 1 or 2 years of age. At Group Health, children who received IPV were less likely to have a missed opportunity by 12 months old (odds ratio [OR] 0.46; 95% CI: 0.31, 0.70), but this finding did not persist at 24 months of age. At Kaiser Permanente, children who received IPV were more likely to have a missed opportunity by 12 months (OR 2.06; 95% CI: 1.84, 2.30), and 24 months of age (OR 1.50; 95% CI: 1.36, 1.67).

CONCLUSIONS

The changeover from an all-OPV schedule to one containing IPV had little if any negative impact on vaccine coverage. Use of IPV was associated with a small increase in the likelihood of being up to date at 2 years of age at one of the HMOs and conversely was associated with a small increase in the likelihood of having a missed-opportunity visit in the other HMO.polio, poliomyelitis, vaccination, immunization coverage.

DNA guanine-guanine crosslinking sequence specificity of isophosphoramide mustard, the alkylating metabolite of the clinical antitumor agent ifosfamide

PURPOSE

The purpose of this investigation was to determine the base sequence specificity of isophosphoramide mustard (IPM), the alkylating metabolite of ifosfamide, by crosslinking of designed DNA oligomers in comparison with the clinical alkylating agents mechlorethamine (ME) (nitrogen mustard) and phosphoramide mustard (PM), the alkylating metabolite of cyclophosphamide.

METHODS

IPM, as well as PM and ME were each reacted with three dodecameric duplexes, which were designed to detect interstrand crosslinking between guanines in 5'-GC-3' (I), 5'-GNC-3' (II) or 5'-GNNC-3' (III) sequences (N = A or T).

RESULTS

All three agents preferentially react with 5'-GNC-3' target sequences. The 5'-GNNC-3' target sequence is less reactive by a factor of approximately 2.5- to 10-fold, while 5'-GC-3' is of even lower reactivity.

CONCLUSION

These results indicate that all three agents show approximately equal preference for reaction with a 5'-GNC-3' target sequence in spite of the fact that IPM yields a 7-atom crosslink, while the other two agents yield 5-atom crosslinks.

Comparative efficacy of several insecticides for control of cattle lice (Mallophaga: Trichodectidae and Anoplura: Haematopinidae)

Several insecticides were applied to cattle at various rates, mixtures, application methods and numbers of treatments and evaluated for control of cattle lice. The insecticides included permethrin at various rates as a pour-on with and without the synergist piperonyl butoxide (PBO), and also at various rates as a spray with and without PBO. Pirimiphos-methyl was evaluated as a pour-on at various rates and with one or two applications. Lambda cyhalothrin in microencapsulated formulation was compared to a non-microencapsulated formulation. Rabon(R) was applied as a pour-on at two rates and at one or two treatments for each rate. Dimilin(R) was applied as a pour-on at two rates and mixed with permethrin and applied at two rates. Five endectocides, Eprinex(R), Ivomec(R), Dectomax(R), Cydectin(R) and Phoenectin(R) were all applied at the same rate. The cattle utilized in this research were all infested with a mixture of lice species. The species included: Bovicola (Damalinia) bovis (L.), Haematopinus eurysternus (Nitzsch), Linognthus vituli (L.) and Solenoptes capillatus (Enderlein). Most of the cattle were infested with at least two species and some had three or all four species present. All of the treatments except permethrin 1.0%+5% PBO, at a rate of 3ml/45.4kgwt. provided acceptable lice control with one application. Data indicated that applying the insecticides in early January should provide enough control to render the need for a second treatment unnecessary.

Measles-mumps-rubella and other measles-containing vaccines do not increase the risk for inflammatory bowel disease: a case-control study from the Vaccine Safety Datalink project

CONTEXT

A link between measles virus-containing vaccines and inflammatory bowel disease (IBD) has been suggested by recent studies.

OBJECTIVE

To address whether receipt or timing of measles-containing vaccine (MCV) increases risk for IBD.

DESIGN

A case-control study.

SETTING

Four large health maintenance organizations (HMOs) that are part of the Centers for Disease Control and Prevention's Vaccine Safety Datalink project.

PATIENTS OR OTHER PARTICIPANTS

A total of 155 persons with codes from International Classification of Diseases, Ninth Revision specific for IBD, born between 1958 and 1989 and enrolled from birth to the onset of disease, were identified. Up to 5 controls were matched by sex, HMO, and birth year.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Risk for IBD, Crohn's disease, and ulcerative colitis.

RESULTS

Past vaccination was not associated with an increased risk for Crohn's disease (odds ratio [OR] for measles-mumps-rubella vaccine [MMR], 0.4; 95% confidence interval [CI], 0.08-2.0), ulcerative colitis (OR, 0.8; 95% CI, 0.18-3.56), or IBD (OR, 0.59; 95% CI, 0.21-1.68). Risk for IBD was not increased among children vaccinated who were younger than 12 months (OR for MMR, 0.61; 95% CI, 0.15-2.45) or aged 12 to 18 months (OR, 0.86; 95% CI, 0.28-2.59) relative to unvaccinated children. Children vaccinated with MMR who were older than 18 months were at significantly decreased risk for IBD (OR, 0.16; 95% CI, 0.04-0.68). Neither past vaccination nor age at vaccination with other MCV was associated with increased risk for Crohn's disease, ulcerative colitis, or IBD. Risk for Crohn's disease, ulcerative colitis, or IBD was not elevated in the time immediately following vaccination with either vaccine.

CONCLUSIONS

Vaccination with MMR or other MCV, or the timing of vaccination early in life, did not increase the risk for IBD.

Introduction of the new Centers for Disease Control and Prevention group B streptococcal prevention guideline at a large West Coast health maintenance organization

OBJECTIVE

Our purpose was to assess the impact of new consensus guidelines issued by the Centers for Disease Control and Prevention, The American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics to prevent perinatal group B streptococcal disease.

STUDY DESIGN

We performed a descriptive analysis and a before-and-after analysis of implementation of the group B streptococcal disease prevention guidelines among singleton-birth pregnancies in 2 Group Health Cooperative hospitals from October 1, 1995, through December 31, 1997. We studied the speed and completeness of implementation and the effect on pregnancy care practices including intrapartum antibiotic use, test ordering, and maternal and neonatal health.

RESULTS

Guideline implementation occurred rapidly. The proportion of term pregnancies screened according to the guideline increased markedly, and overall intrapartum antibiotic use more than doubled. Among group B streptococci-positive women, intrapartum antibiotic prophylaxis increased from 24% before to 74% after guideline implementation. Median duration of treatment before delivery increased from 1.8 to 4.3 hours. The rate of rash did not increase, and there were no cases of anaphylaxis or pseudomembranous colitis. The proportion of infants undergoing evaluation decreased after implementation of the neonatal guidelines; among infants of group B streptococci-negative women, test ordering dropped by almost 40%.

CONCLUSIONS

Implementation of the new guidelines is feasible and can be accomplished rapidly. The guidelines were associated with increased maternal intrapartum antibiotic use, particularly among women at highest risk, and with a decrease in laboratory use for infants.

Does influenza vaccination prevent asthma exacerbations in children?

OBJECTIVE

Influenza can exacerbate asthma, particularly in children. The effectiveness of influenza vaccine in preventing influenza-related asthma exacerbations, however, is not known. We evaluated influenza vaccine effectiveness in protecting children against influenza-related asthma exacerbations.

STUDY DESIGN

We conducted a population-based retrospective cohort study with medical and vaccination records in 4 large health maintenance organizations in the United States during the 1993-1994, 1994-1995, and 1995-1996 influenza seasons. We studied children with asthma who were 1 through 6 years of age and who were identified by search of computerized databases of medical encounters and pharmacy dispensings. Main outcome measures were exacerbations of asthma evaluated in the emergency department or hospital.

RESULTS

Unadjusted rates of asthma exacerbations were higher after influenza vaccination than before vaccination. After adjustment was done for asthma severity by means of a self-control method, however, the incidence rate ratios of asthma exacerbations after vaccination were 0.78 (95% CI: 0.55 to 1.10), 0.59 (0.43 to 0.81), and 0.65 (0.52 to 0.80) compared with the period before vaccination during the 3 influenza seasons.

CONCLUSIONS

After controlling for asthma severity, we found that influenza vaccination protects against acute asthma exacerbations in children.