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ABSTRACT: Genetic variants of polyomavirus SV40 are powerful agents with which to define viral effects on cells and carcinogenesis pathways. We hypothesized that differences in biologic variation among viral strains affect the process of viral infection and are reflected in antibody responses to the viral nonstructural large T-antigen (TAg) protein but not in neutralizing antibody responses against the inoculated viral particles. We analyzed the production of TAg antibody and neutralizing antibody in Syrian golden hamsters that were inoculated with SV40 viral strains by intracardiac, intravenous, or intraperitoneal routes and remained tumor free. Compared with the intraperitoneal route, intravascular (that is, intravenous, intracardiac) inoculation resulted in increased frequency of responsiveness to TAg but not in higher TAg antibody titers. The intravascular route was superior both for eliciting neutralizing antibody responses and for higher titers of those responses. Viruses with complex regulatory regions induced TAg antibody more often than did viruses with simple regulatory regions after intraperitoneal but not intravascular injections, with no differences in antibody titers. This viral genetic variation had no effect on neutralizing antibody production after intraperitoneal or intravascular inoculations or on neutralizing antibody titers achieved. These findings confirm that SV40 variants differ in their biologic properties. Route of inoculation combined with viral genetic variation significantly influence the development of serum antibodies to SV40 TAg in tumor-free hamsters. Route of inoculation-but not viral genetic variation-is an important factor in production of neutralizing antibody to SV40.
Comparative medicine 01/2012; 62(5):400-8. · 1.05 Impact Factor
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ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) is difficult to diagnose and treat. Highly elevated ferritin is strongly associated with HLH and levels may provide a prognostic marker. A comprehensive review of ferritin data from our patients during treatment was analyzed with respect to mortality. A patient was 17 times more likely to die when percent ferritin decrease was less than 50% as compared to a 96% or greater decrease as indicated with multivariate logistic modeling. Higher maximum ferritin levels in the first 3 weeks also contributed to the odds of death (OR = 5.6; 90% CI = 1.2-24.9). Regular ferritin measurements may be useful predicting outcomes in HLH patients.
Pediatric Blood & Cancer 01/2011; 56(1):154-5. · 1.89 Impact Factor
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ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) is difficult to diagnose and treat. Highly elevated ferritin is strongly associated with HLH and levels may provide a prognostic marker. A comprehensive review of ferritin data from our patients during treatment was analyzed with respect to mortality. A patient was 17 times more likely to die when percent ferritin decrease was less than 50% as compared to a 96% or greater decrease as indicated with multivariate logistic modeling. Higher maximum ferritin levels in the first 3 weeks also contributed to the odds of death (OR = 5.6; 90% CI = 1.2–24.9). Regular ferritin measurements may be useful predicting outcomes in HLH patients. Pediatr Blood Cancer. 2010;56:154–155. © 2010 Wiley-Liss, Inc.
Pediatric Blood & Cancer 12/2010; 56(1):154 - 155. · 1.89 Impact Factor
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ABSTRACT: To test the hypothesis that Merkel cell polyomavirus (MCPyV) can infect cells of the lymphoid system, we analyzed 353 specimens, including 152 non-Hodgkin lymphomas, 44 Hodgkin lymphomas, 110 benign lymph nodes, 27 lymph nodes with metastasis, and 20 extranodal tissue samples. MCPyV DNA was detected by quantitative PCR in 13 (6.6%) of 196 lymphomas, including 5 (20.8%) of 24 chronic lymphocytic leukemia specimens, and in 11 (10%) of 110 benign lymph nodes, including 8 (13.1%) of 61 samples of reactive hyperplasia and 3 (10.3%) of 29 normal lymph nodes. Other samples were MCPyV negative. Sequence analysis of 9 virus-positive samples confirmed the identity of MCPyV; 3 viral strains were represented. Immunohistochemical testing showed that 1 T-cell lymphoma expressed MCPyV T-antigen. These findings suggest that the lymphoid system plays a role in MCPyV infection and may be a site for MCPyV persistence.
Emerging Infectious Diseases 11/2010; 16(11):1702-9. · 6.79 Impact Factor
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ABSTRACT: Influenza is an uncontrolled epidemic disease that is vaccine preventable. New recommendations for universal immunization present a challenge to the implementation of vaccine delivery. This field trial examines the effectiveness of school-based clinics for vaccine delivery before an epidemic caused by 3 new influenza virus variants not contained in the vaccine.
Live attenuated influenza vaccine (LAIV) was offered to eligible children in elementary schools of eastern Bell County, Texas. Age-specific rates of medically attended acute respiratory illness for health plan members at the intervention site were compared with those for members at comparison sites during the epidemic, defined by viral surveillance at all sites.
Almost 48% of children in elementary schools were vaccinated. Significant herd protection attributed to LAIV was detected for all age groups except 12-17-year-old students, who were not offered free vaccine. Approximately 2500 medical encounters were prevented at the intervention site. Inactivated vaccine provided marginal protection against the epidemic viruses.
LAIV delivered to elementary-school children before an epidemic caused by 3 new variant influenza viruses generated significant cross-protection for the recipients and indirect (herd) protection for the community.
The Journal of Infectious Diseases 10/2010; 202(11):1626-33. · 6.41 Impact Factor
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ABSTRACT: Because the decision to hospitalize an infant with bronchiolitis is often supported by subjective criteria and objective indicators of bronchiolitis severity are lacking, we tested the hypothesis that lactate dehydrogenase (LDH), which is released from injured cells, is a useful biochemical indicator of bronchiolitis severity.
We retrospectively analyzed a study of children <24 months old presenting to the emergency department with bronchiolitis. Demographic, clinical information, nasal wash (NW), and serum specimens were obtained. NW samples were analyzed for respiratory viruses, caspase 3/7 activity, and a panel of cytokines and chemokines. Total LDH activity was tested in NW samples and sera.
Of 101 enrolled children (median age: 5.6 months), 98 had NW specimens available. A viral etiology was found for 82 patients (83.6%), with respiratory syncytial virus (RSV) (66%) and rhinovirus (19%) being the most common viruses detected. Concentrations of LDH in NW specimens were independent from those in sera and were higher in children with RSV infection or with dual infection. Significant correlations were found between NW LDH and NW cytokines/chemokines. Similarly, NW LDH correlated with NW-caspase 3/7 activity (r = 0.75; P < .001). In a multivariate analysis, NW LDH concentration in the upper quartile was significantly associated with a reduced risk of hospitalization (odds ratio: 0.19 [95% confidence interval: 0.05-0.68]; P = .011).
NW LDH levels in young children with bronchiolitis varied according to viral etiology and disease severity. Values in the upper quartile were associated with approximately 80% risk reduction in hospitalization, likely reflecting a robust antiviral response. NW LDH may be a useful biomarker to assist the clinician in the decision to hospitalize a child with bronchiolitis.
PEDIATRICS 02/2010; 125(2):e225-33. · 4.47 Impact Factor
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ABSTRACT: Seeking screening and treatment for chlamydia (CT) and gonorrhea (GC) by young women is critical to reduction of asymptomatic cervicitis and its complications.
To evaluate the efficacy of a client-centered motivational behavioral intervention (MBI), to promote seeking of sexually tranmitted infection (STI) checkups by young women.
Three hundred seventy-six of 770 eligible sexually active, nonpregnant, English-speaking women (mean age 18.5 years) were recruited from an urban reproductive health clinic and randomized to two groups: intervention plus standard care (MBI) or standard care alone (SC). MBI (two sessions plus booster) was based on the Transtheoretical Model of Change and employed motivational interviewing. Outcome measures monitored for 12 months included: client-initiated clinic visits for STI checkups in response to seven high-risk sexual behaviors by self-report (primary), consistent condom use, number of CT and GC episodes, and movement along the stages of change obtained at baseline and 6- and 12-month follow-up assessments (secondary). Analyses included chi-square, logistic regression, and generalized estimating equations.
At baseline, more than 70% endorsed the action stage of change for seeking STI checkups for three of seven high-risk sexual behaviors. No significant differences were noted between the two groups for the primary or secondary outcomes. Across groups, having multiple partners and being pregnant or thinking one might be pregnant were associated with STI checkups.
This is the first known client-centered clinical trial to promote STI screening. Risk-taking and health-seeking behaviors are complex and interrelated with STI and pregnancy concerns. The intervention may have an effect if it is targeted to women in a less medically connected community-based sample.
Journal of Adolescent Health 02/2010; 46(2):152-61. · 3.33 Impact Factor
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ABSTRACT: An exploratory study identified correlates of consistent condom use for young women reporting Main-new or Main-old partners in the past 3 months: frequency of vaginal sex (across partner types); perceived likelihood of getting a STI (Main-new); age and STI history (Main-old). To enhance programmatic efficacy in community clinics, these key correlates of condom use for main partner types should be incorporated in STI risk reduction counseling.
Journal of Adolescent Health 10/2009; 45(3):296-9. · 3.33 Impact Factor
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ABSTRACT: Studies have reported differing frequencies of detection of polyomavirus simian virus 40 (SV40) in association with human lymphomas.
We addressed the hypothesis that SV40 positivity in lymphomas can vary among sampled populations.
Archival paraffin-embedded lymphoma specimens (n=171) from patients at two urban hospitals in Houston, TX, USA, were analyzed following a cross-sectional study design. Extracted DNAs were characterized by quantitative polymerase chain reaction for the cellular RNase P gene and for SV40 and herpesvirus Epstein-Barr virus (EBV) sequences.
Patient characteristics of the two study populations differed significantly whereas the classification of tumor types studied did not. SV40 DNA was detected more frequently in lymphomas from the public hospital population (10/44, 23%) than in lymphomas from the veterans' hospital (VAMC) (4/127, 3%; P<0.0001). EBV detection in lymphomas also differed between the two groups (17/44, 39% vs. 23/127, 18%; P=0.01). SV40 positivity was associated with a younger age category of VAMC lymphoma patients (P=0.02). Expression of T-antigen was detected by immunohistochemistry in half of lymphomas that contained SV40 DNA. Variation was observed in the quality and quantity of DNA recovered from paraffin-embedded specimens, but there was no difference in recoveries of DNA from samples from the two hospitals.
This study demonstrated that, in a direct comparison, the prevalence of SV40 DNA in lymphomas can differ significantly between groups with different demographic distributions.
Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 07/2009; 46(2):154-60. · 3.12 Impact Factor
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ABSTRACT: To investigate accessing insurance company vaccine reimbursement and coverage information.
A telephone survey was conducted from June 2006 to August 2006. Participating organizations were insurance companies in the states of New York, Oregon, and Texas. The main outcome measure was the obstacles encountered while trying to obtain information on vaccine costs and reimbursement.
Obstacles identified included the predominance of automated answering systems and the necessity of leaving voicemail messages, company nonresponse, and refusal to participate.
Obstacles result in difficulty obtaining vaccine reimbursement and coverage information by phone. Greater transparency is necessary to enable stakeholders to make informed decisions about immunizations.
Journal of Adolescent Health 04/2009; 44(3):298-301. · 3.33 Impact Factor
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ABSTRACT: Interventions that utilize academic detailing to improve childhood immunization have been implemented across the country. This study evaluates the effectiveness of an academic detailing intervention to increase childhood immunization rates in pediatric and family medicine practices in a major metropolitan area. Educational teams of one physician, nurse, and office manager delivered 83 peer education sessions at practices in the intervention group. Postintervention immunization rates for children 12-23 months of age increased 1% in the intervention group and decreased 3% in the control group. Postintervention coverage levels for children 12-23 months of age did not differ between the intervention and control groups. Results indicated this office-based intervention was not sufficient to effect measurable changes in immunization coverage levels after 1 year of participation. Future interventions need to provide initial feedback regarding practice immunization coverage levels prior to the educational interventions and include multiple encounters.
Health Promotion Practice 11/2008; 11(3):377-86.
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ABSTRACT: The purpose of this study was to summarize the radiographic skeletal findings in patients with Rothmund-Thomson syndrome (RTS) and to determine whether there is an association between the presence of skeletal abnormalities and the mutational status of the RECQL4 gene.
Twenty-eight subjects with RTS underwent skeletal surveys and RECQL4 DNA mutation testing. Radiographs were reviewed by two radiologists. RECQL4 mutation testing by DNA sequencing of the gene was performed by a diagnostic laboratory. Genotype-phenotype analysis by Fisher's exact test was performed to investigate whether there was a correlation between mutation status and skeletal abnormalities.
Twenty-one (75%) of the subjects had at least one significant skeletal abnormality, the more common being abnormal metaphyseal trabeculation, brachymesophalangy, thumb aplasia or hypoplasia, osteopenia, dislocation of the radial head, radial aplasia or hypoplasia, and patellar ossification defects. Three subjects had a history of destructive bone lesion (osteosarcoma). Genotype-phenotype analysis showed a significant correlation between RECQL4 mutational status and the presence of skeletal abnormalities (p < 0.0001).
Skeletal abnormalities are frequent in persons with RTS. Many of these abnormalities are not clinically apparent but are detectable on radiographs. The presence of skeletal abnormalities correlates with RECQL4 mutation status, which has been found to correlate with risk of osteosarcoma. Skeletal surveys aid in both diagnosis and management of RTS.
American Journal of Roentgenology 08/2008; 191(2):W62-6. · 2.78 Impact Factor
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ABSTRACT: Hemophagocytic lymphohistiocytosis (HLH) is a potentially lethal condition characterized by a pathologic inflammation. The diagnostic criteria for HLH include fever, splenomegaly, cytopenias, hypertriglyceridemia, hypofibrinogenemia, abnormal natural killer cell (NK cell) functional assay, elevated soluble IL-2Ralpha level, and elevated ferritin level (>500 microg/L). Institution of timely therapy in these critically ill patients may be delayed by difficulties establishing the diagnosis. NK cell functional assay and soluble IL-2Ralpha level may require send-out to a specialized lab. However, ferritin level is available on a same-day basis at most institutions. In this study, we examined the utility of quantitative ferritin levels in diagnosing HLH.
All patients with ferritin values >500 microg/L obtained at Texas Children's Hospital between January 10, 2003 and January 10, 2005 were identified. Patient charts were reviewed for ferritin levels and hospital course.
During the study interval, 330 patients had ferritin levels >500 microg/L. Ten of the 330 patients were diagnosed with HLH. A ferritin level over 10,000 microg/L was 90% sensitive and 96% specific for HLH. Another diagnostic category with significantly elevated ferritin level was illness of unknown cause (n = 10), and only two of these patients were fully evaluated for HLH.
Ferritin levels above 10,000 microg/L appear to be specific and sensitive for HLH. In patients without a significant medical history and a new onset of febrile illness with highly elevated ferritin levels, the diagnosis of HLH should be evaluated.
Pediatric Blood & Cancer 06/2008; 50(6):1227-35. · 1.89 Impact Factor
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ABSTRACT: Provider education programs that use academic detailing to improve childhood immunization have been implemented in several states. The purpose of this study was to evaluate the impact of these types of programs to improve immunization-related behaviors in private provider offices. The intervention included peer-based academic detailing in which teams of 1 physician, 1 nurse, and 1 office manager visited pediatric and family practices to deliver an educational presentation and develop practice-specific action plans. Comparison of pre-post intervention surveys showed that providers' willingness to give the maximum number of immunizations due at 1 visit (P < .001) increased. More providers reported routinely screening immunization records at sickness or injury visits (P < .05) and using minimum intervals (P < .001) postintervention. Mean change in baseline and postintervention overall scores was significant for pediatric practices (0.40, P < .05), small practices (0.64, P < .01), Vaccines for Children (VFC) practices (0.74, P < .05), and non-VFC provider practices (0.67, P < .01) but not for family or large practices.
Clinical Pediatrics 11/2007; 46(8):706-17. · 1.15 Impact Factor
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ABSTRACT: Live attenuated influenza vaccine may protect against wild-type influenza illness shortly after vaccine administration by innate immunity. The 2003-2004 influenza A (H3N2) outbreak arrived early, and the circulating strain was antigenically distinct from the vaccine strain. The objective of this study was to determine the effectiveness of influenza vaccines for healthy school-aged children when administered during the influenza outbreak.
An open-labeled, nonrandomized, community-based influenza vaccine trial was conducted in children 5 to 18 years old. Age-eligible healthy children received trivalent live attenuated influenza vaccine. Trivalent inactivated influenza vaccine was given to children with underlying health conditions. Influenza-positive illness was compared between vaccinated and nonvaccinated children. Medically attended acute respiratory illness and pneumonia and influenza rates for Scott and White Health Plan vaccinees were compared with age-eligible Scott and White Health Plan nonparticipants in the intervention communities. Herd protection was assessed by comparing age-specific medically attended acute respiratory illness rates in Scott and White Health Plan members in the intervention and comparison communities.
We administered 1 dose of trivalent live attenuated influenza vaccine or trivalent inactivated influenza vaccine to 6569 and 1040 children, respectively (31.5% vaccination coverage), from October 10 to December 30, 2003. The influenza outbreak occurred from October 12 to December 20, 2003. Significant protection against influenza-positive illness (37.3%) and pneumonia and influenza events (50%) was detected in children who received trivalent live attenuated influenza vaccine but not trivalent inactivated influenza vaccine. Trivalent live attenuated influenza vaccine recipients had similar protection against influenza-positive illness within 14 days compared with >14 days (10 of 25 vs 9 of 30) after vaccination. Indirect effectiveness against medically attended acute respiratory illness was detected in children 5 to 11 and adults 35 to 44 years of age.
One dose of trivalent live attenuated influenza vaccine was efficacious in children even when administered during an influenza outbreak and when the dominant circulating influenza virus was antigenically distinct from the vaccine strain. We hypothesize that trivalent live attenuated influenza vaccine provides protection against influenza by both innate and adaptive immune mechanisms.
PEDIATRICS 09/2007; 120(3):e553-64. · 4.47 Impact Factor
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Journal of Allergy and Clinical Immunology 04/2007; 119(3):750-2. · 11.00 Impact Factor
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ABSTRACT: Patients with Rothmund-Thomson syndrome (RTS) and RECQL4 gene mutations have an increased risk of developing osteosarcoma (OS). Because RTS is considered a genomic instability syndrome, patients may experience increased toxicity with chemotherapy. The purpose of this study was to summarize the clinical features and response to therapy of OS in patients with RTS. The results of this analysis will help to define treatment guidelines for this complex and rare condition.
An international cohort of patients with RTS and OS was enrolled in an institutional review board-approved study at Baylor College of Medicine (Houston, TX). Medical records were reviewed, and the following information was extracted: clinical features, treatment, pathologic findings, and clinical outcome.
The median age at diagnosis of OS for the 12 patients was 10 years. The most common primary tumor sites were the long bones (femur, tibia); the most frequent histologic subtype was conventional OS. Histologic response to chemotherapy and outcome were similar to other published large series of sporadic OS. Eight patients are alive and disease free; four died as a result of cancer. Five patients required chemotherapy dose modifications, most commonly due to mucositis from doxorubicin.
Our results indicate that patients with RTS and OS are younger, but that their clinical behavior is similar to patients with sporadic OS. Our report suggests that these patients should initially be treated with conventional doses of chemotherapy as prescribed by current protocols; however, cautious and careful clinical observation is warranted to monitor for enhanced doxorubicin sensitivity in patients with RTS.
Journal of Clinical Oncology 03/2007; 25(4):370-5. · 18.37 Impact Factor
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ABSTRACT: As part of the Houston Vanguard study, a subset of 10 patients randomized to receive IL-2 therapy were compared to 4 patients randomized to not receive IL-2, for markers of T cell activation and death during the first three cycles of IL-2. All patients were treated with combination antiretroviral therapy (ART) and were virally suppressed. The purpose of the study was to examine the role of CD8(+) T cell death in responses to ART and IL-2 therapy.
Lymphocytes were examined at Day 0, 5 and 30 days during three cycles of IL-2 therapy. CD25, CD38, HLA-DR expression and annexin (cell death) were examined on CD4 and CD8 subpopulations. Follow up studies examined CD4 levels and CD4:CD8 reconstitution after 6 years using both univariant and multivariate analyses.
Human lymphocytes responded to IL-2 therapy by upregulation of CD25 on CD4(+) T cells, leading to an increase in CD4 cell counts. CD8(+) T cells did not increase CD25 expression, but upregulated activation antigens (CD38 and DR) and had increased death. At baseline, 7 of the 14 patients had high CD8+ T cell apoptosis (mean 17.0% +/- 6.0). We did an exploratory analysis of immune status after six years, and found that baseline CD8+ T cell apoptosis was correlated with CD4 cell count gain beginning two years post enrollment. Patients with low levels of CD8(+) T cell apoptosis at baseline (mean 2.2% +/- 2.1) had significantly higher CD4 cell counts and more normalized CD4:CD8 ratios than patients with high CD8(+) T cell apoptosis (mean CD4 cell counts 1,209 +/- 164 vs 754 +/- 320 cells/mm(3); CD4:CD8 ratios 1.55 vs. 0.70, respectively).
We postulate that CD8(+) T cell apoptosis may reflect inherent activation status, which continues in some patients even though viral replication is suppressed which influences the ability of CD4(+) T cells to rebound. Levels of CD8(+) T cell apoptosis may therefore be an independent predictor of immune status, which should be shown in a prospective study.
Journal of Translational Medicine 02/2007; 5:9. · 3.41 Impact Factor
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ABSTRACT: Few new drugs for treatment of Langerhans cell histiocytosis (LCH) have been studied. Tumor necrosis factor-alpha (TNF-alpha) is a prime therapeutic target since it appears to be present in elevated amounts in LCH lesions. Thalidomide inhibits TNF-alpha production by affecting the gene promoter as well as other anti-cytokine effects.
A Phase II trial of thalidomide for treatment of LCH patients who had failed primary and at least one secondary regimen was conducted. Sixteen patients were enrolled: nine males and seven females ranging in age from 19 months to 45 years. Six patients were high risk (HR) because of spleen, liver, lung, or bone marrow involvement. The low risk (LR) patients included six with bone/skin LCH, one with multiple bone, one with skin/bone/pituitary, one with skin/bone/brain, and one with skin only disease involvement. Fifteen patients remained on treatment from 3 weeks to over 1 year.
Among the LR patients there were four complete responses, three partial responses, and two with no response to thalidomide. No HR patient responded to thalidomide and all died of pulmonary, liver, or bone marrow failure. Thalidomide may have played a role in the pulmonary failure. Other toxicities that required stopping therapy included neutropenia, peripheral neuropathy, and fatigue.
Thalidomide is an effective therapy for some LR patients with LCH, but showed no significant responses in HR patients. Dose-limiting toxicities may reduce its efficacy in LR patients. Additional trials with improved anti-TNF therapies would appear warranted.
Pediatric Blood & Cancer 02/2007; 48(1):44-9. · 1.89 Impact Factor
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ABSTRACT: The aim of the study is to investigate the effect of social context and clinical factors on survival in a cohort of 333 children to identify issues useful in the treatment and care of human immunodeficiency virus (HIV)-infected youth in developing countries.
A prospective cohort study design was used, and data were gathered at baseline and 1-year follow-up. The study cohort consisted of children given a diagnosis of HIV between 1995 and 1999 and receiving medical care in Constanta, Romania. Data were examined by means of multivariate Cox regression analysis models.
The majority of the cohort were in the moderate (41%) or severe (40%) stages of HIV at baseline. Multivariate analysis indicated that social-context factors were the most significant determinants of HIV survival. The hazard for death for those with mothers or fathers with a higher level of education was approximately one quarter (relative hazard, 0.3-0.4; confidence interval, 0.1-1.0) that for a parent with a lower level of education. Subjects with employed mothers were four times more likely to survive than subjects with unemployed mothers.
Results suggest that recognition of social-context risk factors for HIV disease progression and survival is important in developing countries, as it is in developed countries.
Annals of Epidemiology 09/2006; 16(8):593-9. · 3.21 Impact Factor
