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Dive into the research topics where Charles T. Leach is active.

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Featured researches published by Charles T. Leach.


The New England Journal of Medicine | 2011

Oral Acyclovir Suppression and Neurodevelopment after Neonatal Herpes

David W. Kimberlin; Richard J. Whitley; Wen Wan; Dwight A. Powell; Gregory A. Storch; Amina Ahmed; April L. Palmer; Pablo J. Sánchez; Richard F. Jacobs; John S. Bradley; Joan Robinson; Mark J. Shelton; Penelope H. Dennehy; Charles T. Leach; Mobeen H. Rathore; Nazha Abughali; Peter F. Wright; Lisa M. Frenkel; Rebecca C. Brady; Russell B. Van Dyke; Leonard B. Weiner; Judith Guzman-Cottrill; Carol A. McCarthy; Jill Griffin; Penelope Jester; Misty Parker; Fred D. Lakeman; Huichien Kuo; Choo Hyung Lee; Gretchen A. Cloud

BACKGROUND Poor neurodevelopmental outcomes and recurrences of cutaneous lesions remain unacceptably frequent among survivors of neonatal herpes simplex virus (HSV) disease. METHODS We enrolled neonates with HSV disease in two parallel, identical, double-blind, placebo-controlled studies. Neonates with central nervous system (CNS) involvement were enrolled in one study, and neonates with skin, eye, and mouth involvement only were enrolled in the other. After completing a regimen of 14 to 21 days of parenteral acyclovir, the infants were randomly assigned to immediate acyclovir suppression (300 mg per square meter of body-surface area per dose orally, three times daily for 6 months) or placebo. Cutaneous recurrences were treated with open-label episodic therapy. RESULTS A total of 74 neonates were enrolled--45 with CNS involvement and 29 with skin, eye, and mouth disease. The Mental Development Index of the Bayley Scales of Infant Development (in which scores range from 50 to 150, with a mean of 100 and with higher scores indicating better neurodevelopmental outcomes) was assessed in 28 of the 45 infants with CNS involvement (62%) at 12 months of age. After adjustment for covariates, infants with CNS involvement who had been randomly assigned to acyclovir suppression had significantly higher mean Bayley mental-development scores at 12 months than did infants randomly assigned to placebo (88.24 vs. 68.12, P=0.046). Overall, there was a trend toward more neutropenia in the acyclovir group than in the placebo group (P=0.09). CONCLUSIONS Infants surviving neonatal HSV disease with CNS involvement had improved neurodevelopmental outcomes when they received suppressive therapy with oral acyclovir for 6 months. (Funded by the National Institute of Allergy and Infectious Diseases; CASG 103 and CASG 104 ClinicalTrials.gov numbers, NCT00031460 and NCT00031447, respectively.).


Pediatric Infectious Disease Journal | 1996

Administration of oral acyclovir suppressive therapy after neonatal herpes simplex virus disease limited to the skin, eyes and mouth: Results of a phase I/II trial

David W. Kimberlin; Dwight A. Powell; William C. Gruber; Pamela S. Diaz; Ann M. Arvin; Mary L. Kumar; Richard F. Jacobs; Russell B. Van Dyke; Sandra K. Burchett; Seng Jaw Soong; Alfred D. Lakeman; Richard J. Whitley; C. Laughlin; Richard Whitley; A. Lakeman; S. J. Soong; D. Kimberlin; Sergio Stagno; Robert F. Pass; A. Arvin; Charles G. Prober; John S. Bradley; Stephen A. Spector; Larry Corey; Gail J. Demmler; S. Burchett; Stuart P. Adler; James F. Bale; Yvonne J. Bryson; Tasnee Chonmaitree

BACKGROUND Neonatal herpes simplex virus (HSV) infections limited to the skin, eyes and mouth (SEM) can result in neurologic impairment. A direct correlation exists between the development of neurologic deficits and the frequency of cutaneous HSV recurrences. Thus, the National Institutes of Allergy and Infectious Diseases Collaborative Antiviral Study Group conducted a Phase I/II trial of oral acyclovir therapy for the suppression of cutaneous recurrences after SEM disease in 26 neonates. METHODS Infants < or = 1 month of age with virologically confirmed HSV-2 SEM disease were eligible for enrollment. Suppressive oral acyclovir therapy (300 mg/m2/dose given either twice daily or three times per day) was administered for 6 months. RESULTS Twelve (46%) of the 26 infants developed neutropenia (< 1000 cells/mm3) while receiving acyclovir. Thirteen (81%) of the 16 infants who received drug 3 times per day experienced no recurrences of skin lesions while receiving therapy. In comparison, a previous Collaborative Antiviral Study Group study found that only 54% of infants have no cutaneous recurrences in the 6 months after resolution of neonatal HSV disease if oral acyclovir suppressive therapy is not initiated. In one infant, HSV DNA was detected in the cerebrospinal fluid during a cutaneous recurrence, and an acyclovir-resistant HSV mutant was isolated from another patient during the course of the study. CONCLUSIONS Administration of oral acyclovir can prevent cutaneous recurrences of HSV after neonatal SEM disease. The effect of such therapy on neurologic outcome must be assessed in a larger, Phase III study. As such, additional investigation is necessary before routine use of suppressive therapy in this population can be recommended.


Leukemia & Lymphoma | 1997

Benign and Malignant Smooth Muscle Tumors Containing Epstein-Barr Virus in Children with AIDS

Hal B. Jenson; Charles T. Leach; Kenneth L. McClain; Vijay V. Joshi; Brad H. Pollock; Richard T. Parmley; Ellen G. Chadwick; Sharon B. Murphy

Smooth muscle tumors (leiomyosarcomas) are the second most prevalent malignancy of children with the acquired immunodeficiency syndrome (AIDS). We have investigated the tumors, plasma, and peripheral white blood cells of eight children with AIDS with smooth muscle tumors for evidence of tumor association with human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV). Very low levels of HIV were found in the tumors of the AIDS patients, probably resulting from blood-borne carriage of virus. These smooth muscle tumors had very high quantities of EBV in all the tumor cells by in situ hybridization, with an average of 4.5 EBV genomes per cell by quantitative polymerase chain reaction amplification. Increased amounts of EBV were found in the peripheral blood cells of two AIDS patients before the time of tumor diagnosis. EBV clonality studies demonstrated different monoclonal EBV infection of two separate colonic tumors from one patient, and dual or mixed monoclonal EBV infection in another patient. The muscle cells of leiomyomas and leiomyosarcomas of patients with AIDS demonstrated prominent staining with antibodies to the EBV receptor. The uniform distribution and striking amount of EBV in the tumor cells demonstrates that EBV is capable of infecting smooth muscle cells and that these cells support EBV replication. Clonal EBV proliferation suggests that EBV infection occurs at an early stage of tumor development. These findings indicate that EBV has a causal role in the oncogenesis of leiomyosarcomas of patients with AIDS.


Clinical Infectious Diseases | 2004

Methicillin-Resistant Staphylococcus aureus Infection in the Texas Prison System

Jacques Baillargeon; Michael F. Kelley; Charles T. Leach; Gwen Baillargeon; Brad H. Pollock

Recent reports indicate that correctional facility inmates may be at elevated risk for contracting methicillin-resistant Staphylococcus aureus (MRSA) infection because of overcrowding, poor hygiene, and high rates of diseases causing immunosuppression. The present study of 299,179 Texas inmates who were incarcerated between 1999-2001 indicated an incidence of 12 MRSA infections/1000 person-years. Inmates with circulatory disease, cardiovascular disease, diabetes, end-stage liver disease, end-stage renal disease, human immunodeficiency virus infection or acquired immunodeficiency syndrome, and skin diseases all exhibited elevated rates of MRSA infection.


The Journal of Infectious Diseases | 1998

Antibodies to Kaposi's Sarcoma—Associated Herpesvirus (Human Herpesvirus 8) in Patients with Multiple Myeloma

Shou Jiang Gao; Melissa Alsina; Jian Hong Deng; Chantal R. Harrison; Eduardo A. Montalvo; Charles T. Leach; G. David Roodman; Hal B. Jenson

Kaposis sarcoma-associated herpesvirus (KSHV) serologic assays were used to detect specific antibodies to KSHV lytic and latent antigens in 27 patients with multiple myeloma, 27 control patients with other cancers, and 50 random blood donors. Antibodies to KSHV recombinant minor capsid antigen orf65 were found in 81% of patients with multiple myeloma, 22% of control patients with other cancers, and 6% of the blood donors. Antibodies to KSHV latent nuclear antigens were found in 52% of patients with multiple myeloma, 26% of control patients with other cancers, and 2% of the blood donors. All of the 11 patients with progressive multiple myeloma were KSHV-seropositive. Antibodies to Epstein-Barr virus nuclear antigen 1 were present in 89% of patients with multiple myeloma, 93% of control patients with other cancers, and 88% of the blood donors. These data support the possible association of KSHV infection with multiple myeloma, particularly with progressive disease.


PLOS Genetics | 2013

A genome-wide integrative genomic study localizes genetic factors influencing antibodies against Epstein-Barr virus nuclear antigen 1 (EBNA-1).

Rohina Rubicz; Robert H. Yolken; Eugene Drigalenko; Melanie A. Carless; Thomas D. Dyer; Lara E. Bauman; Phillip E. Melton; Jack W. Kent; John B. Harley; Joanne E. Curran; Matthew P. Johnson; Shelley A. Cole; Laura Almasy; Eric K. Moses; Nikhil V. Dhurandhar; Ellen Kraig; John Blangero; Charles T. Leach; Harald H H Göring

Infection with Epstein-Barr virus (EBV) is highly prevalent worldwide, and it has been associated with infectious mononucleosis and severe diseases including Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal lymphoma, and lymphoproliferative disorders. Although EBV has been the focus of extensive research, much still remains unknown concerning what makes some individuals more sensitive to infection and to adverse outcomes as a result of infection. Here we use an integrative genomics approach in order to localize genetic factors influencing levels of Epstein Barr virus (EBV) nuclear antigen-1 (EBNA-1) IgG antibodies, as a measure of history of infection with this pathogen, in large Mexican American families. Genome-wide evidence of both significant linkage and association was obtained on chromosome 6 in the human leukocyte antigen (HLA) region and replicated in an independent Mexican American sample of large families (minimum p-value in combined analysis of both datasets is 1.4×10−15 for SNPs rs477515 and rs2516049). Conditional association analyses indicate the presence of at least two separate loci within MHC class II, and along with lymphocyte expression data suggest genes HLA-DRB1 and HLA-DQB1 as the best candidates. The association signals are specific to EBV and are not found with IgG antibodies to 12 other pathogens examined, and therefore do not simply reveal a general HLA effect. We investigated whether SNPs significantly associated with diseases in which EBV is known or suspected to play a role (namely nasopharyngeal lymphoma, Hodgkin lymphoma, systemic lupus erythematosus, and multiple sclerosis) also show evidence of associated with EBNA-1 antibody levels, finding an overlap only for the HLA locus, but none elsewhere in the genome. The significance of this work is that a major locus related to EBV infection has been identified, which may ultimately reveal the underlying mechanisms by which the immune system regulates infection with this pathogen.


Diabetes Care | 2013

Long-Term Changes in Adiposity and Glycemic Control Are Associated With Past Adenovirus Infection

Wan-Yu Lin; Olga Dubuisson; Rohina Rubicz; Nianjun Liu; David B. Allison; Joanne E. Curran; Anthony G. Comuzzie; John Blangero; Charles T. Leach; Harald H H Göring; Nikhil V. Dhurandhar

OBJECTIVE Ad36, a human adenovirus, increases adiposity but improves glycemic control in animal models. Similarly, natural Ad36 infection is cross-sectionally associated with greater adiposity and better glycemic control in humans. This study compared longitudinal observations in indices of adiposity (BMI and body fat percentage) and glycemic control (fasting glucose and insulin) in Ad36-infected versus uninfected adults. RESEARCH DESIGN AND METHODS Baseline sera from Hispanic men and women (n = 1,400) were screened post hoc for the presence of Ad36-specific antibodies. Indices of adiposity and glycemic control at baseline and at ∼10 years past the baseline were compared between seropositive and seronegative subjects, with adjustment for age and sex. In addition to age and sex, indices of glycemic control were adjusted for baseline BMI and were analyzed only for nondiabetic subjects. RESULTS Seropositive subjects (14.5%) had greater adiposity at baseline, compared with seronegative subjects. Longitudinally, seropositive subjects showed greater adiposity indices but lower fasting insulin levels. Subgroup analyses revealed that Ad36-seropositivity was associated with better baseline glycemic control and lower fasting insulin levels over time in the normal-weight group (BMI ≤25 kg/m2) and longitudinally, with greater adiposity in the overweight (BMI 25–30 kg/m2) and obese (BMI >30 kg/m2) men. Statistically, the differences between seropositive and seronegative individuals were modest in light of the multiple tests performed. CONCLUSIONS This study strengthens the plausibility that in humans, Ad36 increases adiposity and attenuates deterioration of glycemic control. Panoptically, the study raises the possibility that certain infections may modulate obesity or diabetes risk. A comprehensive understanding of these under-recognized factors is needed to effectively combat such metabolic disorders.


Pediatric Infectious Disease Journal | 2010

Safety of Oseltamivir Compared With the Adamantanes in Children Less Than 12 Months of Age

David W. Kimberlin; Marwan Shalabi; Mark J. Abzug; David Lang; Richard F. Jacobs; Gregory A. Storch; John S. Bradley; Kelly C. Wade; Octavio Ramilo; José R. Romero; Mark J. Shelton; Charles T. Leach; Judith Guzman-Cottrill; Joan Robinson; Nazha Abughali; Janet A. Englund; Jill Griffin; Penny Jester; Gretchen A. Cloud; Richard J. Whitley

Background: When oseltamivir is administered in extremely high doses (500–1000 mg/kg) to young juvenile rats, central nervous system toxicity and death occurred in some animals. Mortality was not observed in older juvenile rats, suggesting a possible relationship between neurotoxicity and an immature blood-brain barrier. To assess potential neurologic adverse effects of oseltamivir use in infants, a retrospective chart review was performed in infants less than 12 months of age who received oseltamivir, amantadine, or rimantadine. Methods: The primary objective was to describe the frequency of neurologic adverse events among children less than 12 months of age who received oseltamivir compared with those receiving adamantanes. Medical record databases, emergency department databases, and/or pharmacy records at 15 medical centers were searched to identify patients. Results: Of the 180 infants identified as having received antiviral therapy, 115 (64%) received oseltamivir, 37 (20%) received amantadine, and 28 (16%) received rimantadine. The median dose of oseltamivir was 2.0 mg/kg/dose in 3- to 5-month-old and 2.2 mg/kg/dose in 9- to 12-month-old infants. The maximum dose administered was 7.0 mg/kg/dose. There were no statistically significant differences in the occurrence of adverse neurologic events during therapy among subjects treated with oseltamivir versus those treated with the adamantanes (P = 0.13). Conclusions: This is the largest report to date of oseltamivir use in children less than 12 months of age. Neurologic events were not more common with use of oseltamivir compared with that of the adamantanes. Dosing of oseltamivir was variable, illustrating the need for pharmacokinetic data in this younger population.


Clinical Infectious Diseases | 2000

Antiretroviral Prescribing Patterns in the Texas Prison System

Jacques Baillargeon; Michael J. Borucki; Stephanie Zepeda; Hal B. Jenson; Charles T. Leach

Although the prevalence of human immunodeficiency virus (HIV) infection among prison inmates is reported to be high, little is known about anti-HIV treatment patterns in correctional institutions. The present study assessed antiretroviral prescribing patterns for 2360 Texas Department of Criminal Justice (TDCJ) inmates infected with HIV. In 1998, 66.8% of all TDCJ inmates infected with HIV who had CD4 lymphocyte counts < 500 cells/mm(3) were treated with highly active antiretroviral therapy (HAART). However, no substantial differences in the use of HAART were exhibited according to the sociodemographic factors under study. While the majority of inmates receiving HAART in 1998 were prescribed a combination of 2 nucleoside reverse transcriptase inhibitors (NRTIs) and 1 protease inhibitor, 11.2% were prescribed a combination of 2 NRTIs and 1 non-NRTI. In view of the elevated rate of HIV infection in correctional settings, it will be important to continue to document the pharmacotherapy patterns among prison inmates, both during and following incarceration.


The Journal of Infectious Diseases | 1999

The Epidemiology of Viral Hepatitis in Children in South Texas: Increased Prevalence of Hepatitis A along the Texas-Mexico Border

Charles T. Leach; Felix C. Koo; Susan G. Hilsenbeck; Hal B. Jenson

An initial retrospective study of 194 children demonstrated a high prevalence of hepatitis A but not hepatitis B or C infection among children living along the Texas-Mexico border. A larger prospective study of hepatitis A was conducted with 285 children (aged 6 months to 13 years) living in 3 sociodemographically dissimilar areas of South Texas. Children living in colonías along the border had a significantly higher prevalence of hepatitis A virus infection (37%) than children living in urban border communities (17%) or in a large metropolitan area (San Antonio [6%]). Independent risk factors for hepatitis A infection included increased age, colonía residence, and history of residence in a developing country. Use of bottled water (vs. municipal or spring/well water) and years of maternal secondary education were protective. Improved sanitation or routine hepatitis A vaccination in early childhood may reduce the prevalence of hepatitis A in these areas.

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Hal B. Jenson

University of Texas Health Science Center at San Antonio

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Ellen G. Chadwick

Baylor College of Medicine

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Gary D. Overturf

University of Southern California

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Leonard B. Weiner

State University of New York Upstate Medical University

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Geoffrey A. Weinberg

Centers for Disease Control and Prevention

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Jacques Baillargeon

University of Texas Medical Branch

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