bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibiotic Resistance Patterns of Community-Acquired Urinary Tract Infections in Children With Vesicoureteral Reflux Receiving Prophylactic Antibiotic Therapy
Authors: Cheng Chi-Hui , Tsai Ming-Horng , Huang Yhu-Chering , Su Lin-Hui , Tsau Yong-Kwei , Lin Chi-Jen , Chiu Cheng-Hsun , Lin Tzou-Yien
Published: December 2008

OBJECTIVE. The goal was to examine bacterial antimicrobial resistance of recurrent urinary tract infections in children receiving antibiotic prophylaxis because of primary vesicoureteral reflux.

METHODS. We reviewed data retrospectively for children with documented vesicoureteral reflux in 2 hospitals during a 5-year follow-up period. The patients were receiving co-trimoxazole, cephalexin, or cefaclor prophylaxis or prophylaxis with a sequence of different antibiotics (alternative monotherapy). Demographic data, degree of vesicoureteral reflux, prophylactic antibiotics prescribed, and antibiotic sensitivity results of first urinary tract infections and breakthrough urinary tract infections were recorded.

RESULTS. Three hundred twenty-four patients underwent antibiotic prophylaxis (109 with co-trimoxazole, 100 with cephalexin, 44 with cefaclor, and 71 with alternative monotherapy) in one hospital and 96 children underwent co-trimoxazole prophylaxis in the other hospital. Breakthrough urinary tract infections occurred in patients from both hospitals (20.4% and 25%, respectively). Escherichia coli infection was significantly less common in children receiving antibiotic prophylaxis, compared with their initial episodes of urinary tract infection, at both hospitals. Children receiving cephalosporin prophylaxis were more likely to have an extended-spectrum β-lactamase-producing organism for breakthrough urinary tract infections, compared with children with co-trimoxazole prophylaxis. Antimicrobial susceptibilities to almost all antibiotics decreased with cephalosporin prophylaxis when recurrent urinary tract infections developed. The extent of decreased susceptibilities was also severe for prophylaxis with a sequence of different antibiotics. However, antimicrobial susceptibilities decreased minimally in co-trimoxazole prophylaxis groups.

CONCLUSIONS. Children receiving cephalosporin prophylaxis are more likely to have extended-spectrum β-lactamase-producing bacteria or multidrug-resistant uropathogens other than E coli for breakthrough urinary tract infections; therefore, these antibiotics are not appropriate for prophylactic use in patients with vesicoureteral reflux. Co-trimoxazole remains the preferred prophylactic agent for vesicoureteral reflux.
Quality of Care for Common Pediatric Respiratory Illnesses in United States Emergency Departments: Analysis of 2005 National Hospital Ambulatory Medical Care Survey Data
Authors: Knapp Jane F. , Simon Stephen D. , Sharma Vidya
Published: December 2008

OBJECTIVE. The goal was to measure US emergency department performance in the pediatric care of asthma, bronchiolitis, and croup, by using systematically developed quality indicators.

METHODS. Data on visits to emergency departments by children 1 to 19 years of age with moderate/severe asthma, 3 months to 2 years of age with bronchiolitis, and 3 months to 3 years of age with croup from the 2005 National Hospital Ambulatory Medical Care Survey, with a nationally representative sample of US patients, were analyzed. We used national rates of use of corticosteroids, antibiotics, and radiographs as our main outcome measures.

RESULTS. Physicians prescribed corticosteroids in 69% of the estimated 405 000 annual visits for moderate/severe asthma and in 31% of the estimated 317 000 annual croup visits. Children with bronchiolitis received antibiotics in 53% of the estimated 228 000 annual visits. Physicians obtained radiographs in 72% of bronchiolitis visits and 32% of croup visits.

CONCLUSIONS. Physicians treating children with asthma, bronchiolitis, and croup in US emergency departments are underusing known effective treatments and overusing ineffective or unproven therapies and diagnostic tests.
Active, Population-Based Surveillance for Severe Rotavirus Gastroenteritis in Children in the United States
Authors: Payne Daniel C. , Staat Mary Allen , Edwards Kathryn M. , Szilagyi Peter G. , Gentsch Jon R. , Stockman Lauren J. , Curns Aaron T. , Griffin Marie , Weinberg Geoffrey A. , Hall Caroline B. , Fairbrother Gerry , Alexander James , Parashar Umesh D.
Published: December 2008

OBJECTIVES. Routine vaccination of US infants against rotavirus was implemented in 2006, prompting the Centers for Disease Control and Prevention New Vaccine Surveillance Network to begin population-based acute gastroenteritis surveillance among US children <3 years of age. This surveillance system establishes baseline estimates of rotavirus disease burden and allows for the prospective monitoring of rotavirus vaccination impact.

METHODS. Eligible children with acute gastroenteritis (≥3 episodes of diarrhea and/or any vomiting in a 24-hour period) who were hospitalized, were seen in emergency departments, or visited selected outpatient clinics in 3 US counties during the period of January through June 2006 were enrolled. Epidemiological and clinical information was obtained through parental interview and medical chart review, and stool specimens were tested for rotavirus with enzyme immunoassays. Rotavirus-positive specimens were genotyped by using reverse transcription-polymerase chain reaction assays.

RESULTS. Stool specimens were collected from 516 of the 739 enrolled children with acute gastroenteritis (181 inpatient, 201 emergency department, and 134 outpatient) and 44% tested positive for rotavirus (227 of 516 specimens). The most common strain was P[8]G1 (84%), followed by P[4]G2 (5%) and P[6]G12 (4%). None of the 516 children had received rotavirus vaccine. The rotavirus detection rate was 50% for hospitalized acute gastroenteritis cases, 50% for emergency department visits, and 27% for outpatient visits. Rotavirus-related acute gastroenteritis cases were more likely than non–rotavirus-related acute gastroenteritis cases to present with vomiting, diarrhea, fever, and lethargy. Directly calculated, population-based rates for rotavirus hospitalizations and emergency department visits were 22.5 hospitalizations and 301.0 emergency department visits per 10 000 children <3 years of age, respectively. A sentinel outpatient clinic visit rate of 311.9 outpatient visits per 10 000 children <3 years of age was observed.

CONCLUSIONS. Population-based, laboratory-confirmed rotavirus surveillance in the final rotavirus season before implementation of the US rotavirus vaccine program indicated a considerable burden of disease on the US health care system.
HLA-A33 Is Associated With Susceptibility to Enterovirus 71 Infection
Authors: Chang Luan-Yin , Chang I-Shou , Chen Wei-Jen , Huang Yhu-Cherng , Chen Guang-Wu , Shih Shin-Ru , Juang Jyh-Lyh , Shih Hsiu-Ming , Hsiung Chao A. , Lin Tzou-Yien , Huang Lin-Min
Published: December 2008

OBJECTIVE. Enterovirus 71 has caused large epidemics of disease, resulting in many fatalities and severe sequelae, in Taiwan and some other countries. In this study, host genetic factors were investigated to link susceptibility to and clinical severity of enterovirus 71 infections.

METHODS. We enrolled 219 enterovirus 71 case subjects and 97 control children. HLA typing was performed with sequence-specific primers, and polymorphisms of immune-related candidate genes were detected with polymerase chain reaction, followed by automated gene sequencing.

RESULTS. Of the 219 enterovirus 71 cases, 26% (56 of 219 cases) were uncomplicated cases, 74% (163 of 219 cases) were complicated cases, 57% (125 of 219 cases) were complicated cases with central nervous system involvement, and 17% (38 of 219 cases) involved cardiopulmonary failure after central nervous system involvement. Univariate analyses showed that tumor necrosis factor α promoter type II (−308 A allele), HLA-A33, and HLA-DR17 were significantly associated with enterovirus 71 susceptibility. Multivariate analysis demonstrated that HLA-A33 was the gene most significantly susceptible to enterovirus 71. HLA-A2 was associated with the development of cardiopulmonary failure.

CONCLUSIONS. HLA-A33, which is a common phenotype in Asian populations but is rare in white populations, was most significantly associated with enterovirus 71 infection, compared with the other candidate genes we studied, whereas HLA-A2 was significantly related to cardiopulmonary failure.
At What Age Do Children Start Taking Daily Asthma Medicines on Their Own?
Authors: Orrell-Valente Joan K. , Jarlsberg Leah G. , Hill Laura G. , Cabana Michael D.
Published: December 2008

OBJECTIVE. Use of daily controller medications is a critical task in management of persistent asthma. Study aims were to examine (1) the association between child age and extent of daily controller-medication responsibility in a sample aged 4 to 19 years, (2) parent, child, and disease predictors of child daily controller-medication responsibility and overall daily controller-medication adherence, and (3) the association between child daily controller-medication responsibility and overall daily controller-medication adherence.

METHODS. We conducted a cross-sectional telephone survey of 351 parents of children who were prescribed daily controller medication. Children's mean age was 10.4 years; 61.5% were male, and 88.1% were white. Parents provided all data, including an estimate of the percentage of child and parent daily controller-medication responsibility. Daily controller-medication adherence was measured as parents' report of percentage of daily doses taken per doses prescribed in a typical week. We used multivariate linear regression to determine associations between parent race/ethnicity, education, income, number of dependents, child age, gender, years since diagnosis, parent perception of symptom severity and control, and dependent variables (child daily controller-medication responsibility and daily controller-medication adherence). We also examined associations between child daily controller-medication responsibility and daily controller-medication adherence.

RESULTS. Child daily controller-medication responsibility increased with age. By age 7, children had assumed, on average, almost 20% of daily controller-medication responsibility; by age 11, ∼50%; by age 15, 75%; and by age 19, 100%. In multivariate models, child age and male gender remained significantly associated with child daily controller-medication responsibility, and child's age and parents' race/ethnicity remained significantly associated with daily controller-medication adherence.

CONCLUSIONS. Clinicians may need to screen for child daily controller-medication management and include even young children when educating families on the use of asthma medications and other key asthma-management tasks.
Estimated Savings From Paid Telephone Consultations Between Subspecialists and Primary Care Physicians
Authors: Wegner Steven E. , Humble Charles G. , Feaganes John , Stiles Alan D.
Published: December 2008

OBJECTIVES. Pediatric subspecialists are not routinely reimbursed by Medicaid or insurance payers for telephone consultations. Generally, access to pediatric subspecialists is limited because of the small number of providers, their concentration in academic medical centers, and increasing demand for their services. Little is known about the nature of such consults, the time required to provide them, or whether there is a positive economic impact for payers.

METHODS. Between March and October of 2007, pediatric subspecialists from 6 academic medical centers in North Carolina completed consultation reimbursement-request forms to prospectively track their telephone consultations with primary care physicians for the care of Medicaid patients <22 years of age. Data collected included the amount of time required per consult and consult outcomes in terms of service use and quality of care. Medicaid claims records and primary care physician surveys were used to validate the pediatric subspecialist consultation outcomes.

RESULTS. A total of 47 pediatric subspecialists provided 306 consults regarding the care of 292 Medicaid-insured children over the 8 study months. Telephone consults were generally <15 minutes in length and exceeded 30 minutes in <7% of calls. Pediatric subspecialists reported that telephone consults led to avoidance of specialist visits (n = 98), hospital transfers (n = 35), hospital admissions (n = 14), and emergency department visits (n = 14). Medicaid claims data supported these reports; matched primary care physician surveys suggested even higher levels of service avoidance. After adjusting for the reimbursed costs of providing telephone consults, an estimated $477274 was saved ($39 per dollar spent).

CONCLUSIONS. Telephone consultations with pediatric subspecialists provide a valuable service to primary care physicians providing medical homes to Medicaid patients. Rewarding physicians for telephone consults seems to be cost-effective because of reduced use of costly services and reported improvements in quality of care.
Epidemiological Features of Clostridium difficile-Associated Disease Among Inpatients at Children's Hospitals in the United States, 2001–2006
Authors: Kim Jason , Smathers Sarah A. , Prasad Priya , Leckerman Kateri H. , Coffin Susan , Zaoutis Theoklis
Published: December 2008

OBJECTIVE. Clostridium difficile is the main cause of nosocomial and antibiotic-associated diarrhea in adults. Recently, the incidence and severity of C difficile-associated disease in adults have been increasing. Whether similar phenomena are occurring among children remains unknown. Our study describes the epidemiological features of C difficile-associated disease in hospitalized children.

METHODS. We conducted a retrospective cohort study of hospitalized children with C difficile-associated disease at 22 freestanding children's hospitals in the United States, from 2001 to 2006. Cases of C difficile-associated disease were defined as a hospitalized child with a discharge code for C difficile infection, a laboratory billing charge for a C difficile toxin assay, and receipt of antimicrobial therapy for C difficile-associated disease.

RESULTS. We identified 4895 patients with C difficile-associated disease. Over the study period, the annual incidence of C difficile-associated disease increased from 2.6 to 4.0 cases per 1000 admissions and from 4.4 to 6.5 cases per 10 000 patient-days. The median age of children with C difficile-associated disease was 4 years. Twenty-six percent of patients were <1 year of age. The majority of patients (67%) had underlying chronic medical conditions. The colectomy and all-cause mortality rates among children with C difficile-associated disease did not increase during the study period.

CONCLUSIONS. The annual incidence of C difficile-associated disease in hospitalized children increased significantly from 2001 to 2006. However, the rates of colectomy and in-hospital death have not increased in children with C difficile-associated disease as they have among adults. The risk factors and outcomes for children with C difficile-associated disease remain to be defined in future studies.
Hearing Loss in Children With Congenital Cytomegalovirus Infection in Relation to the Maternal Trimester in Which the Maternal Primary Infection Occurred
Authors: Foulon Ina , Naessens Anne , Foulon Walter , Casteels Ann , Gordts Frans
Published: December 2008

OBJECTIVES. The purpose of this work was to study the relation between maternal trimester of primary infection with cytomegalovirus and the occurrence of sensorineural hearing loss in the congenitally infected offspring.

PATIENTS AND METHODS. Thirty-four consecutive live-born children diagnosed with a congenital cytomegalovirus infection after maternal primary cytomegalovirus infections were included in the study. Five were lost for follow-up, and 1 died. Of the remaining 28 congenitally infected children, an estimation of the maternal trimester in which cytomegalovirus primary infection occurred was performed. All of the children were investigated for potential sensorineural hearing loss.

RESULTS. Five of the maternal infections occurred in the first trimester, 12 in the second trimester, and 11 in the third trimester of pregnancy. Sensorineural hearing loss was detected in 4 (80%) of the 5 congenitally infected children who were infected after a primary maternal infection in the first trimester of pregnancy and in 1 (8%) of the 12 children when the maternal infection occurred in the second trimester of pregnancy. No sensorineural hearing loss was detected after primary maternal infection occurring in the third trimester. Fluctuation and improvement of sensorineural hearing loss were seen regardless the trimester of pregnancy during which maternal primary infection occurred. Progression of sensorineural hearing loss occurred in 2 children born after a maternal primary infection of the first trimester.

CONCLUSIONS. Hearing loss seemed more common in infants with congenital cytomegalovirus infection who were born to women who experienced a primary cytomegalovirus infection in the first trimester of pregnancy than when infection took place later in pregnancy.
A National Profile of the Health Care Experiences and Family Impact of Autism Spectrum Disorder Among Children in the United States, 2005–2006
Authors: Kogan Michael D. , Strickland Bonnie B. , Blumberg Stephen J. , Singh Gopal K. , Perrin James M. , van Dyck Peter C.
Published: December 2008

OBJECTIVES. We sought to examine the health care experiences of children with autism spectrum disorder and the impact of autism spectrum disorder on the family and to assess whether having a medical home is associated with less family impact.

METHODS. We used the 2005–2006 National Survey of Children With Special Health Care Needs to compare 2088 children with special health care needs, aged 3 to 17 years, reported by their parents to have autism spectrum disorder, with children with special health care needs with “other emotional, developmental, or behavioral problems” (excluding autism spectrum disorder; n = 9534) and 26751 other children with special health care needs. We used weighted logistic regression to examine unmet needs for specific health care and support services, delayed care, no usual care source or personal physician, difficulty receiving referrals, and financial, employment, or time problems because of child's care.

RESULTS. Nationally, an estimated 535000 children have special health care needs and autism spectrum disorder, a prevalence of 86 per 10000 children aged 3 to 17 years. Among children with special health care needs, 5.6% have autism spectrum disorder. Compared with other children with special health care needs without emotional, developmental, or behavioral problems, children with special health care needs with autism spectrum disorder were more likely to have unmet needs for specific health care services, family support services, delayed or foregone care, difficulty receiving referrals, and care that is not family centered. Children with special health care needs with autism spectrum disorder were more likely to live in families that report financial problems, need additional income for the child's medical care, reduce or stop work because of the child's condition, spend ≥10 hours per week providing or coordinating care, and paid more than $1000 in the previous year for the child's care. The financial impacts of autism spectrum disorder were significantly more burdensome when children with special health care needs did not have a medical home.

CONCLUSIONS. Children with special health care needs with autism spectrum disorder are significantly more likely to have problems regarding access to care and unmet needs, and their families have greater financial, employment, and time burdens compared with other children with special health care needs. Receipt of primary care in a medical home may reduce these burdens.
Sleep Terrors in Children: A Prospective Study of Twins
Authors: Nguyen Bich Hong , Pérusse Daniel , Paquet Jean , Petit Dominique , Boivin Michel , Tremblay Richard E. , Montplaisir Jacques
Published: December 2008

OBJECTIVE. There is growing evidence that genetic factors are involved in the occurrence of sleep terrors. Twin studies provide invaluable information regarding genetic and environmental factors that can affect the manifestation of the disease; however, most previous twin studies on sleep terrors were performed retrospectively or with a sample that was too small to yield conclusive results. The aim of this large prospective study was to clarify the genetic and environmental contributions to sleep terrors in childhood.

METHODS. In all, 390 pairs of monozygotic and dizygotic twins were recruited at birth for a longitudinal study. The prevalence and frequency of sleep terrors were assessed at 18 and 30 months of age with a questionnaire administered to the biological mother of the twins. Zygosity was determined by a questionnaire and genotyping. The prevalence and polychoric correlation for each type of twins were calculated. Structural-equation modeling was used to determine the proportion of variance attributable to additive genetic, shared, and nonshared environmental factors.

RESULTS. The prevalence of sleep terrors was 36.9% at 18 months and 19.7% at 30 months; 49% of affected children were boys, and 51% were girls. At 18 months, the polychoric correlations were 0.63 for monozygotic and 0.36 for the dizygotic twins. These were 0.68 (monozygotic) and 0.24 (dizygotic) at 30 months. Our model-fitting analysis showed that sleep terrors were explained by a 2-component model at 18 months (43.7% additive genetic effects and 56.3% nonshared environment) and at 30 months (41.5% additive genetic effects and 58.5% nonshared environment).

CONCLUSIONS. These results strongly support the heritability of sleep terrors. There also seems to be continuity in genetic effects with the persistence of sleep-terror symptoms.
Strengthening the Case: Prenatal Alcohol Exposure Is Associated With Increased Risk for Conduct Disorder
Authors: Disney Elizabeth R. , Iacono William , McGue Matthew , Tully Erin , Legrand Lisa
Published: December 2008

OBJECTIVE. The purpose of this study was to examine the relationship between alcohol exposure in pregnancy and offspring conduct disorder symptoms in adolescence and to examine how much this increasingly known association may be mediated by maternal and paternal externalizing diagnoses, including lifetime maternal and paternal alcohol and drug abuse/dependence diagnoses as well as antisocial disorders. Few other studies have examined the contribution of these diagnoses across both parents.

METHOD. A population sample of 1252 adolescents (53.8% female; drawn from the Minnesota Twin Family Study) as well as both of their parents completed structured diagnostic interviews to generate lifetime psychiatric diagnoses; mothers were also retrospectively interviewed about alcohol and nicotine use during pregnancy. Linear regression models were used to test the effects of prenatal alcohol exposure on adolescents' conduct-disorder symptoms.

RESULTS. Prenatal exposure to alcohol was associated with higher levels of conduct-disorder symptoms in offspring, even after statistically controlling for the effects of parental externalizing disorders (illicit substance use disorders, alcohol dependence, and antisocial/behavioral disorders), prenatal nicotine exposure, monozygosity, gestational age, and birth weight.

CONCLUSIONS. Prenatal alcohol exposure contributes to increased risk for conduct disorder in offspring.
Randomized Pilot Study Comparing Oral Ibuprofen With Intravenous Ibuprofen in Very Low Birth Weight Infants With Patent Ductus Arteriosus
Authors: Cherif Ahmed , Khrouf Naima , Jabnoun Sami , Mokrani Chahnez , Amara Moez Ben , Guellouze Nedia , Kacem Samia
Published: December 2008

BACKGROUND. We conducted a prospective, randomized, single-masked pilot study with the principal aim of comparing efficacy and tolerance between oral and intravenous ibuprofen in early closure of patent ductus arteriosus in very low birth weight infants. The possibility of ductal closure with only 1 or 2 doses of treatment was a secondary objective.

MATERIAL AND METHODS. Sixty-four very low birth weight patients with echocardiographically confirmed patent ductus arteriosus and respiratory distress were studied. The patients were randomly assigned to receive either oral (group O, n = 32) or intravenous (group I, n = 32) ibuprofen starting on the third day of life. After the first dose of treatment in both groups, echocardiographic evaluation was performed to determine the need for a second or third dose. The rate of ductal closure, adverse effects, complications, and the patient's clinical course were recorded.

RESULTS. In each group, 24 (75%) patients were born after 28 weeks' gestation. The rate of ductal closure tended to increase in group O (84.3% vs 62.5%). Closure of the ductus was obtained after 1 or 2 doses of treatment in 19 (70.3%) of 27 patients in group O and 14 (70%) of 20 patients in group I. The adverse effects were increased in group I (31.2% vs 9.3%). There were no significant differences with respect to complications during the stay. Adverse effects were significantly fewer when closure was achieved after an incomplete course of treatment (23.1% vs 76.9%).

CONCLUSIONS. In very low birth weight infants, the rate of early ductal closure with oral ibuprofen is at least as good as with the intravenous route. Ductal closure may be obtained with an incomplete course of ibuprofen. Oral ibuprofen is associated with fewer adverse effects. However, a larger sample is needed for more definitive conclusions.
Variation in Provider Vaccine Purchase Prices and Payer Reimbursement
Authors: Freed Gary L. , Cowan Anne E. , Gregory Sashi , Clark Sarah J.
Published: December 2008

OBJECTIVE. The purpose of this work was to collect data regarding vaccine prices and reimbursements in private practices. Amid reports of physicians losing money on vaccines, there are limited supporting data to show how much private practices are paying for vaccines and how much they are being reimbursed by third-party payers.

METHODS. We conducted a cross-sectional survey of a convenience sample of private practices in 5 states (California, Georgia, Michigan, New York, and Texas) that purchase vaccines for administration to privately insured children/adolescents. Main outcome measures included prices paid to purchase vaccines recommended for children and adolescents and reimbursement from the 3 most common, non-Medicaid payers for vaccine purchase and administration.

RESULTS. Detailed price and reimbursement data were provided by 76 practices. There was a considerable difference between the maximum and minimum prices paid by practices, ranging from $4 to more than $30 for specific vaccines. There was also significant variation in insurance reimbursement for vaccine purchase, with maximum and minimum reimbursements for a single vaccine differing from $8 to more than $80. Mean net yield per dose (reimbursement for vaccine purchase minus price paid per dose) varied across vaccines from a low of approximately $3 to more than $24. Reimbursement for the first dose of vaccine administered ranged from $0 to more than $26, with a mean of $16.62.

CONCLUSIONS. There is a wide range of prices paid by practices for the same vaccine product and in the reimbursement for vaccines and administration fees by payers. This variation highlights the need for individual practices to understand their own costs and reimbursements and to seek opportunities to reduce costs and increase reimbursements.
In Vitro Differentiation of Embryonic and Adult Stem Cells into Hepatocytes: State of the Art
Authors: Snykers Sarah , De Kock Joery , Rogiers Vera , Vanhaecke Tamara
Published: December 2008

Stem cells are a unique source of self-renewing cells within the human body. Before the end of the last millennium, adult stem cells, in contrast to their embryonic counterparts, were considered to be lineage-restricted cells or incapable of crossing lineage boundaries. However, the unique breakthrough of muscle and liver regeneration by adult bone marrow stem cells at the end of the 1990s ended this long-standing paradigm. Since then, the number of articles reporting the existence of multipotent stem cells in skin, neuronal tissue, adipose tissue, and bone marrow has escalated, giving rise, both in vivo and in vitro, to cell types other than their tissue of origin. The phenomenon of fate reprogrammation and phenotypic diversification remains, though, an enigmatic and rare process. Understanding how to control both proliferation and differentiation of stem cells and their progeny is a challenge in many fields, going from preclinical drug discovery and development to clinical therapy. In this review, we focus on current strategies to differentiate embryonic, mesenchymal(-like), and liver stem/progenitor cells into hepatocytes in vitro. Special attention is paid to intracellular and extracellular signaling, genetic modification, and cell-cell and cell-matrix interactions. In addition, some recommendations are proposed to standardize, optimize, and enrich the in vitro production of hepatocyte-like cells out of stem/progenitor cells.
Urban resilience and national security: the role for planning
Authors: Coaffee J. , O’Hare P.
Published: December 2008

In recent years, the activity of protecting against and planning responses to the wide range of security challenges that threaten cities and urban areas—from natural disasters such as flooding and anthropogenic climate change to crime and terrorism—has been referred to as ‘urban resilience’. In this sense, urban resilience refers to both the design alterations (structural, architectural, land-use planning) and managerial and governance measures that seek to prevent or mitigate the physical and social vulnerability of areas, ultimately to protect life, property and economic activity. Against this background, this paper analyses attempts to embed physical and managerial resilience in urban areas to counter the risk from terrorist attacks. Specifically, it highlights the expanded role for the spatial planning system in meeting and mediating pressures for increased safety and security. Drawing on historical examples, but paying particular attention to the current UK context, the paper details how the planning profession is becoming more responsible for counter-terrorism; this is leading not only to requirements for further training but also to concerns regarding efficacy. This work also questions how proportionate the pressures to achieve counter-terrorism resilience are, particularly given the higher likely incidence and impact of natural disasters.
Sublethal effects of methylmercury on fecal metabolites of testosterone, estradiol, and corticosterone in captive juvenile white ibises (Eudocimus albus)
Authors: Adams Evan M. , Frederick Peter C. , Larkin Iske L. V. , Guillette Louis J.
Published: December 2008

Methylmercury (MeHg) is a globally distributed neurotoxin, endocrine disruptor, and teratogen, and its effects on birds are poorly understood, especially within an environmentally relevant exposure range. In an effort to understand the potential causal relationship between MeHg exposure and endocrine development, we established four dietary exposure groups (0 [control], 0.05, 0.1, and 0.3 mg/kg wet wt/d of MeHg) of postfledging white ibises (Eudocimus albus) in a divided, free-flight aviary that spanned the estimated range of environmental exposure for this species. Fecal samples were collected from individually identified ibises over six months in 2005 and processed for hormone evaluation. Significant sex-related differences in fecal estradiol concentrations, though unpredicted in direction, suggest that this steroid could be related to juvenile development in this species. Using repeated-measures general linear models, we tested a set of candidate models to explain variation in endocrine expression. We found that MeHg exposure led to significant differences in fecal estradiol concentrations between the control and medium-dose groups, whereas differences in fecal corticosterone concentrations were observed between the control and both the low- and high-dose groups. These results suggest highly nonlinear dose-response patterns for MeHg. Many endocrine-disrupting contaminants are theorized to affect multiple endpoints in a nonlinear manner, making results difficult to interpret using a traditional toxicological approach. The evidence presented here suggests that endocrine effects of MeHg exposure could behave similarly.
ASSESSING POTENCY OF HIGH‐ AND LOW‐PREFERENCE REINFORCERS WITH RESPECT TO RESPONSE RATE AND RESPONSE PATTERNS
Authors: Penrod Becky , Wallace Michele D. , Dyer Edwin J.
Published: December 2008

Previous research has suggested that the availability of high‐preference stimuli may override the reinforcing efficacy of concurrently available low‐preference stimuli under relatively low schedule requirements (e.g., fixed‐ratio 1 schedule). It is unknown if similar effects would be obtained under higher schedule requirements. Thus, the current study compared high‐preference and low‐preference reinforcers under progressively increasing schedule requirements. Results for 3 of the 4 participants indicated that high‐preference stimuli maintained responding under higher schedule requirements relative to low‐preference stimuli. For 1 participant, high‐preference and low‐preference stimuli were demonstrated to be equally effective reinforcers under increasing schedule requirements. Implications with respect to rate of performance and response patterns are discussed.
EFFECTS OF WITHIN‐CLASS DIFFERENCES IN SAMPLE RESPONDING ON ACQUIRED SAMPLE EQUIVALENCE
Authors: Urcuioli Peter J. , Vasconcelos Marco
Published: December 2008

Two experiments examined whether acquired sample equivalence in many‐to‐one matching was affected by variation in sample‐response requirements. In each experiment, pigeons responded on either identical or different response schedules to the sample stimuli that occasioned the same reinforced comparison choice (i.e., to the within‐class samples). Transfer‐of‐control tests were then conducted to determine acquired equivalence, or lack thereof, between these samples. In both experiments, there was minimal or no evidence of acquired sample equivalence when pigeons responded differently to the samples within each common‐choice class. By contrast, transfer was observed if pigeons responded (a) identically to all sample stimuli, or (b) identically to samples within each common‐choice class (viz., to samples that occasioned the same reinforced choice) and differently to samples from different classes (viz., to samples that occasioned different choices). These results may help to explain the recent lack of evidence for response membership in pigeons' acquired equivalence (Urcuioli, Lionello‐DeNolf, Michalek, & Vasconcelos, 2006). They also raise questions about the functional sample stimuli and about possible interactions between acquired equivalence and acquired distinctiveness.
NODAL STRUCTURE AND THE PARTITIONING OF EQUIVALENCE CLASSES
Authors: Fields Lanny , Watanabe‐Rose Mari
Published: December 2008

By definition, all of the stimuli in an equivalence class have to be functionally interchangeable with each other. The present experiment, however, demonstrated that this was not the case when using post‐class‐formation dual‐option response transfer tests. With college students, two 4‐node 6‐member equivalence classes with nodal structures of A→B→C→D→E→F were produced by training AB, BC, CD, DE' and EF. Then, unique responses were trained to the c and D stimuli in each class. The responses trained to c generalized to B and A, while the responses trained to D generalized to E and F. Thus, each 4‐node 6‐member equivalence class was bifurcated into two 3‐member functional classes: A→B→C and D→E→F, with class membership precisely predicted by nodal structure. A final emergent relations test documented the intactness of the underlying 4‐node 6‐member equivalence classes. The coexistence of the interchangeability of stimuli in an equivalence class and the bifurcation of such a class in terms of nodal structure was explained in the following manner. The conditional discriminations that are used to establish a class also imposes a nodal structure on the stimuli in the class. Thus, the stimuli in the class acquire two sets of relational properties. if the format of a test trial allows only one response option per class, responding on those trials will be in accordance with class membership and will not express the effects of nodal distance. if the format of a test trial allows more than one response option per class, responding on those trials will be determined by the nodal structure of the class. Thus, the relational properties expressed by the stimuli in an equivalence class are determined by the discriminative function served by the format of a test trial.
THE ROLE OF NAMING IN STIMULUS CATEGORIZATION BY PRESCHOOL CHILDREN
Authors: Miguel Caio F. , Petursdottir Anna I. , Carr James E. , Michael Jack
Published: December 2008

The purpose of the current study was to assess whether children would categorize pictures when taught the relevant listener and speaker behaviors separately. A category‐sort test was used to assess emergent conditional relations. Category‐sort trials consisted of looking at (Test 1) or tacting/labeling (Test 2) a sample stimulus and selecting the appropriate comparison stimuli. In Experiment 1, 4 children (35 years) were taught to tact pictures of six U.S. state maps as either north or south. An assessment was conducted to determine whether they would (1) correctly categorize or sort when presented with a visual sample and (2) select the correct stimuli when hearing their category names (listener behavior). Two of the children categorized the pictures during Posttest 1 after the initial (pairwise) tact training. The other 2 categorized after receiving additional tact training with all pictures presented together. However, one of them categorized only during Posttest 2. In Experiment 2, 4 children (3–5 years) were taught to select pictures when hearing their category names. An assessment was conducted to determine whether they would (1) correctly categorize or sort and (2) tact the stimuli (speaker behavior). one child categorized the pictures during Posttest 1, and two during Posttest 2. The other child required additional training with all pictures grouped together. When participants failed to categorize, they also failed to tact the pictures accurately. Taken together, results from Experiments 1 and 2 show that both speaker and listener behavior play an important role in stimulus categorization.
Racial, Ethnic, and Socioeconomic Differences in the Incidence of Obesity Related to Childbirth
Authors: Davis Esa M. , Zyzanski Stephen J. , Olson Christine M. , Stange Kurt C. , Horwitz Ralph I.
Published: December 2008

Objectives. We investigated the relationship between childbirth and 5-year incidence of obesity.

Methods. We performed a prospective analysis of data on 2923 nonobese, nonpregnant women aged 14 to 22 years from the 1979 National Longitudinal Survey of Youth Cohort, which was followed from 1980 to 1990. We used multivariable logistic regression analyses to determine the adjusted relative risk of obesity for mothers 5 years after childbirth compared with women who did not have children.

Results. The 5-year incidence of obesity was 11.3 per 100 parous women, compared with 4.5 per 100 nulliparous women (relative risk [RR] = 3.5; 95% confidence interval [CI] = 2.4, 4.9; P < .001). The 5-year incidence of obesity was 8.6 for primiparous women (RR = 2.8; 95% CI = 1.5, 5.0) and 12.2 for multiparous women (RR = 3.8; 95% CI = 2.6, 5.6). Among parous women, White women had the lowest obesity incidence (9.1 per 100 vs 15.1 per 100 for African Americans and 12.5 per 100 for Hispanics).

Conclusions. Parous women have a higher incidence of obesity than do nulliparous women, and minority women have a higher incidence of parity-related obesity than do White women. Thus, efforts to reduce obesity should target postpartum women and minority women who give birth.
Integrating Nutrition Support for Food-Insecure Patients and Their Dependents Into an HIV Care and Treatment Program in Western Kenya
Authors: Mamlin Joseph , Kimaiyo Sylvester , Lewis Stephen , Tadayo Hannah , Jerop Fanice Komen , Gichunge Catherine , Petersen Tomeka , Yih Yuehwern , Braitstein Paula , Einterz Robert
Published: December 2008

The Academic Model Providing Access to Healthcare (AMPATH) is a partnership between Moi Teaching and Referral Hospital, Moi University School of Medicine, and a consortium of universities led by Indiana University. AMPATH has over 50 000 patients in active care in 17 main clinics around western Kenya.

Despite antiretroviral therapy, many patients were not recovering their health because of food insecurity. AMPATH therefore established partnerships with the World Food Program and United States Agency for International Development and began high-production farms to complement food support.

Today, nutritionists assess all AMPATH patients and dependents for food security and refer those in need to the food program. We describe the implementation, challenges, and successes of this program.
Ethical Issues in Public Health Practice in Michigan
Authors: Baum Nancy M. , Gollust Sarah E. , Goold Susan D. , Jacobson Peter D.
Published: December 2008

Objectives. We sought to ascertain the types of ethical challenges public health practitioners face in practice and to identify approaches used to resolve such challenges.

Methods. We conducted 45 semistructured interviews with public health practitioners across a range of occupations (e.g., health officers, medical directors, sanitarians, nurses) at 13 health departments in Michigan.

Results. Through qualitative analysis, we identified 5 broad categories of ethical issues common across occupations and locations: (1) determining appropriate use of public health authority, (2) making decisions related to resource allocation, (3) negotiating political interference in public health practice, (4) ensuring standards of quality of care, and (5) questioning the role or scope of public health. Participants cited a variety of values guiding their decision-making that did not coalesce around core values often associated with public health, such as social justice or utilitarianism. Public health practitioners relied on consultations with colleagues to resolve challenges, infrequently using frameworks for decision-making.

Conclusions. Public health practitioners showed a nuanced understanding of ethical issues and navigated ethical challenges with minimal formal assistance. Decision-making guides that are empirically informed and tailored for practitioners might have some value.
Spousal and Alcohol-Related Predictors of Smoking Cessation: A Longitudinal Study in a Community Sample of Married Couples
Authors: Dollar Katherine M. , Homish Gregory G. , Kozlowski Lynn T. , Leonard Kenneth E.
Published: December 2008

We investigated the longitudinal influence of spousal and individual heavy drinking and heavy smoking on smoking cessation among married couples. Couples' (N = 634) past-year smoking, alcohol problems, and heavy drinking were assessed. We used an event history analysis and found that spousal and one's own heavy smoking and one's own heavy drinking decreased the likelihood of smoking cessation. Heavy drinking and spousal behavior should be considered when developing public health interventions and policies for smoking cessation.
An Individually Tailored Intervention for HIV Prevention: Baseline Data From the EXPLORE Study
Authors: Chesney Margaret A. , Koblin Beryl A. , Barresi Patrick J. , Husnik Marla J. , Celum Connie L. , Colfax Grant , Mayer Kenneth , McKirnan David , Judson Franklyn N. , Huang Yijian , Coates Thomas J. ,   the EXPLORE Study Team
Published: December 2008

Objectives. We describe the intervention tested in EXPLORE, an HIV prevention trial aimed at men who have sex with men (MSM), and test the empirical basis of the individually tailored intervention.

Methods. Data on participants’ self-efficacy, communication skills, social norms, and enjoyment of unprotected anal intercourse were examined in relation to sexual risk. Combinations of these factors, together with alcohol use and noninjection drug use, were also examined.

Results. The individual factors examined were associated with sexual risk behavior. The cohort was shown to be heterogeneous in regard to the presence of combinations of these risk-related factors.

Conclusions. Baseline data from the EXPLORE study support the efficacy of the individually tailored intervention used.
Trend analysis in Icelandic discharge, temperature and precipitation series by parametric methods
Authors: Jónsdóttir Jóna Finndís , Uvo Cintia B. , Clarke Robin T.
Published: December 2008

This paper presents results of analyses by parametric methods of annual means of temperature, precipitation and discharge, and of seasonal maximum precipitation at 17, 28 and 10 Icelandic stations, respectively, for the period 1961–2000. Trends in mean seasonal temperature and precipitation are in broad agreement with results found by other authors using other methods. A positive trend appears in both mean annual temperature and mean temperatures in most seasons. Annual mean precipitation trends are positive in most seasons except for negative trends in the September–November season in the south. Additionally, positive trends appear in maximum one-, three- and five-day precipitation, both during the spring and autumn, except at a group of stations in central Iceland. Some of the positive trends in mean annual and seasonal precipitation may, however, be attributed to the positive trend in temperature which may have influenced gauge catch. Trends in mean annual and seasonal discharge are small and statistically insignificant; the trends found in temperature and precipitation do not all relate directly to trends in discharge but suggest hypotheses for further study of the relationships between them.
Prediction of salinity intrusion in Danshuei estuarine system
Authors: Etemad-Shahidi A. , Dorostkar A. , Liu Wen-Cheng
Published: December 2008

The main parameters that affect the flow conditions and intrusion of salt water in an estuary system are tides and the seasonal variation of water discharge. A laterally averaged two-dimensional numerical model called MIKE 11 XZ is used to simulate the hydrodynamics and salinity intrusion of Danshuei River estuarine system. This model can simulate hydrodynamics and water quality in estuaries, reservoirs and lakes. MIKE 11 XZ solves the Reynolds-averaged Navier–Stokes equations by using Abbott–Ionescu finite difference scheme in a non-dimensional vertical σ-coordinate. Vertical eddy diffusivity in the model can be determined by a constant value, a mixing length theory and a k or k−ɛ turbulence closure scheme with Richardson number correction. A series of comprehensive field data obtained from Danshuei estuarine system is used for evaluation, calibration and verification of the model. The friction coefficient was calibrated and verified using water surface elevation and velocity measurements, respectively. Then the vertical eddy diffusivity was calibrated and verified through comparison of salinity measurements in different layers of several stations. Reasonable agreement was obtained between the model results and the observed data using k−ɛ turbulence closure scheme. The model application was investigated with different discharges and the effect of discharge variation on salinity intrusion was determined. The results showed that the fresh water discharge is the main parameter that affects the salinity intrusion in this system. Finally, simple power equations are suggested to predict the salinity intrusion due to the fresh water discharge in different tributaries of the system.