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Dive into the research topics where William W. Greenfield is active.

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Featured researches published by William W. Greenfield.


Journal of Perinatology | 2013

Telemedicine collaboration improves perinatal regionalization and lowers statewide infant mortality.

Elizabeth W. Kim; Terri J. Teague-Ross; William W. Greenfield; D. Keith Williams; Dennis Z. Kuo; Richard W. Hall

Objective:We assessed a telemedicine (TM) network’s effects on decreasing deliveries of very low birth weight (VLBW, <1500 g) neonates in hospitals without Neonatal Intensive Care Units (NICUs) and statewide infant mortality.Study design:This prospective study used obstetrical and neonatal interventions through TM consults, education and census rounds with 9 hospitals from 1 July 2009 to 31 March 2010. Using a generalized linear model, Medicaid data compared VLBW birth sites, mortality and morbidity before and after TM use. Arkansas Health Department data and χ2 analysis were used to compare infant mortality.Result:Deliveries of VLBW neonates in targeted hospitals decreased from 13.1 to 7.0% (P=0.0099); deliveries of VLBW neonates in remaining hospitals were unchanged. Mortality decreased in targeted hospitals (13.0% before TM and 6.7% after TM). Statewide infant mortality decreased from 8.5 to 7.0 per 1000 deliveries (P=0.043).Conclusion:TM decreased deliveries of VLBW neonates in hospitals without NICUs and was associated with decreased statewide infant mortality.


Clinical and Vaccine Immunology | 2015

Cross-Reactivity, Epitope Spreading, and De Novo Immune Stimulation Are Possible Mechanisms of Cross-Protection of Nonvaccine Human Papillomavirus (HPV) Types in Recipients of HPV Therapeutic Vaccines

Mayumi Nakagawa; William W. Greenfield; Andréa M. Moerman-Herzog; Hannah N. Coleman

ABSTRACT Numerous versions of human papillomavirus (HPV) therapeutic vaccines designed to treat individuals with established HPV infection, including those with cervical intraepithelial neoplasia (CIN), are in development because approved prophylactic vaccines are not effective once HPV infection is established. As human papillomavirus 16 (HPV-16) is the most commonly detected type worldwide, all versions of HPV therapeutic vaccines contain HPV-16, and some also contain HPV-18. While these two HPV types are responsible for approximately 70% of cervical cancer cases, there are other high-risk HPV types known to cause malignancy. Therefore, it would be of interest to assess whether these HPV therapeutic vaccines may confer cross-protection against other high-risk HPV types. Data available from a few clinical trials that enrolled subjects with CINs regardless of the HPV type(s) present demonstrated clinical responses, as measured by CIN regression, in subjects with both vaccine-matched and nonvaccine HPV types. The currently available evidence demonstrating cross-reactivity, epitope spreading, and de novo immune stimulation as possible mechanisms of cross-protection conferred by investigational HPV therapeutic vaccines is discussed.


OncoImmunology | 2015

A phase I dose-escalation clinical trial of a peptide-based human papillomavirus therapeutic vaccine with Candida skin test reagent as a novel vaccine adjuvant for treating women with biopsy-proven cervical intraepithelial neoplasia 2/3

William W. Greenfield; Shawna L. Stratton; Rebecca S Myrick; Rita Vaughn; Lisa M. Donnalley; Hannah N. Coleman; Maria Mercado; Andréa M. Moerman-Herzog; Horace J. Spencer; Nancy R Andrews-Collins; Wilbur C. Hitt; Gordon Low; Nirvana Manning; Samantha S. McKelvey; Dora Smith; Michael V. Smith; Phillips Am; C. Matthew Quick; Susanne K. Jeffus; Laura F. Hutchins; Mayumi Nakagawa

PURPOSE: Non-surgical treatments for cervical intraepithelial neoplasia 2/3 (CIN2/3) are needed as surgical treatments have been shown to double preterm delivery rate. The goal of this study was to demonstrate safety of a human papillomavirus (HPV) therapeutic vaccine called PepCan, which consists of four current good-manufacturing production-grade peptides covering the HPV type 16 E6 protein and Candida skin test reagent as a novel adjuvant. PATIENTS AND METHODS: The study was a single-arm, single-institution, dose-escalation phase I clinical trial, and the patients (n = 24) were women with biopsy-proven CIN2/3. Four injections were administered intradermally every 3 weeks in limbs. Loop electrical excision procedure (LEEP) was performed 12 weeks after the last injection for treatment and histological analysis. Six subjects each were enrolled (50, 100, 250, and 500 μg per peptide). RESULTS: The most common adverse events (AEs) were injection site reactions, and none of the patients experienced dose-limiting toxicities. The best histological response was seen at the 50 μg dose level with a regression rate of 83% (n = 6), and the overall rate was 52% (n = 23). Vaccine-induced immune responses to E6 were detected in 65% of recipients (significantly in 43%). Systemic T-helper type 1 (Th1) cells were significantly increased after four vaccinations (P = 0.02). CONCLUSION: This study demonstrated that PepCan is safe. A significantly increased systemic level of Th1 cells suggests that Candida, which induces interleukin-12 (IL-12) in vitro, may have a Th1 promoting effect. A phase II clinical trial to assess the full effect of this vaccine is warranted.


Clinical Trials | 2015

A novel use of a statewide telecolposcopy network for recruitment of participants in a Phase I clinical trial of a human papillomavirus therapeutic vaccine.

Shawna L. Stratton; Horace J. Spencer; William W. Greenfield; Gordon Low; Wilbur C. Hitt; Charles M. Quick; Susanne K. Jeffus; Victoria Blackmon; Mayumi Nakagawa

Background: Historically, recruitment and retention of young women in intervention-based clinical trials have been challenging. In August 2012, enrollment for a clinical trial testing of an investigational human papillomavirus therapeutic vaccine called PepCan was opened at our institution. This study was an open-label, single-arm, single-institution, dose-escalation Phase I clinical trial. Women with recent Papanicolaou smear results showing high-grade squamous intraepithelial lesions or results that could not rule out high-grade squamous intraepithelial lesion were eligible to enroll. Patients with biopsy-confirmed high-grade squamous intraepithelial lesion were also eligible. Colposcopy was performed at the screening visit, and participants became eligible for vaccination when the diagnosis of high-grade squamous intraepithelial lesion was confirmed with biopsy and other inclusion criteria were met. The aim of this study was to identify strategies and factors effective in recruitment and retention of study participants. Methods: Potential vaccine candidates were recruited through direct advertisement as well as referrals, including referrals through the Arkansas telecolposcopy network. The network is a federally funded program, administered by physicians and advanced practice nurses. The network telemedically links rural health sites and allows physician-guided colposcopy and biopsies to be conducted by advanced practice nurses. A variety of strategies were employed to assure good retention, including face-to-face contact with the study coordinator at the time of consent and most of study visits; frequent contact using text messaging, phone calls, and e-mails; and creation of a private Facebook page to improve communication among research staff and study participants. A questionnaire, inquiring about motivation for joining the study, occupation, education, household income, number of children, and number of sexual partners, was administered at the screening visit with the intent of identifying factor(s) associated with recruitment and retention. Results: A total of 37 participants were enrolled between September 2012 and March 2014. The largest proportion of participants (46%) was enrolled from the telecolposcopy network. Others were enrolled through outside institutions (43%), in-house referrals (8%), or direct advertisement (3%). Most participants were motivated to join the study to take care of their health issues. Only two participants joined the Facebook private page. Of the 24 participants who qualified for vaccination, only 1 terminated early due to an unanticipated move. Conclusion: The availability of a large number of potential participants from the telecolposcopy network increased recruitment to this clinical trial by 85% over other traditional means of recruitment. The telecolposcopy network is not only a means of providing a gynecological service to women who otherwise would forego care but also a novel and valuable resource in recruiting participants for a clinical trial.


Journal of Visualized Experiments | 2012

Use of Interferon-γ Enzyme-linked Immunospot Assay to Characterize Novel T-cell Epitopes of Human Papillomavirus

Xuelian Wang; William W. Greenfield; Hannah N. Coleman; Lindsey E. James; Mayumi Nakagawa

A protocol has been developed to overcome the difficulties of isolating and characterizing rare T cells specific for pathogens, such as human papillomavirus (HPV), that cause localized infections. The steps involved are identifying region(s) of HPV proteins that contain T-cell epitope(s) from a subject, selecting for the peptide-specific T cells based on interferon-γ (IFN-γ) secretion, and growing and characterizing the T-cell clones (Fig. 1). Subject 1 was a patient who was recently diagnosed with a high-grade squamous intraepithelial lesion by biopsy and underwent loop electrical excision procedure for treatment on the day the T cells were collected(1). A region within the human papillomavirus type 16 (HPV 16) E6 and E7 proteins which contained a T-cell epitope was identified using an IFN- g enzyme-linked immunospot (ELISPOT) assay performed with overlapping synthetic peptides (Fig. 2). The data from this assay were used not only to identify a region containing a T-cell epitope, but also to estimate the number of epitope specific T cells and to isolate them on the basis of IFN- γ secretion using commercially available magnetic beads (CD8 T-cell isolation kit, Miltenyi Biotec, Auburn CA). The selected IFN-γ secreting T cells were diluted and grown singly in the presence of an irradiated feeder cell mixture in order to support the growth of a single T-cell per well. These T-cell clones were screened using an IFN- γ ELISPOT assay in the presence of peptides covering the identified region and autologous Epstein-Barr virus transformed B-lymphoblastoid cells (LCLs, obtained how described by Walls and Crawford)(2) in order to minimize the number of T-cell clone cells needed. Instead of using 1 x 10(5) cells per well typically used in ELISPOT assays(1,3), 1,000 T-cell clone cells in the presence of 1 x 10(5) autologous LCLs were used, dramatically reducing the number of T-cell clone cells needed. The autologous LCLs served not only to present peptide antigens to the T-cell clone cells, but also to keep a high cell density in the wells allowing the epitope-specific T-cell clone cells to secrete IFN-γ. This assures successful performance of IFN-γ ELISPOT assay. Similarly, IFN- γ ELISPOT assays were utilized to characterize the minimal and optimal amino acid sequence of the CD8 T-cell epitope (HPV 16 E6 52-61 FAFRDLCIVY) and its HLA class I restriction element (B58). The IFN- γ ELISPOT assay was also performed using autologous LCLs infected with vaccinia virus expressing HPV 16 E6 or E7 protein. The result demonstrated that the E6 T-cell epitope was endogenously processed. The cross-recognition of homologous T-cell epitope of other high-risk HPV types was shown. This method can also be used to describe CD4 T-cell epitopes(4).


Journal of Maternal-fetal & Neonatal Medicine | 2015

Maternal and perinatal outcomes of indicated inductions of labor.

Everett F. Magann; Songthip Ounpraseuth; Christina D. Miller; Sarah A. Novotny; Nicole Lee; William W. Greenfield; John C. Morrison

Abstract Purpose: The purpose of this study was to evaluate the labor characteristics and maternal/perinatal consequences following indicated induction of labor. Methods: This retrospective study examined all of the indicated inductions over 24 months and at two institutions evaluated mode of delivery (vaginal versus cesarean) as well as a comprehensive list of labor characteristics and maternal/perinatal outcomes. Results: There were 1577 indicated inductions with 1097/1577 (69.6%) delivering vaginally. Women with a cesarean delivery had lower parity (p < (0).0001) and Bishop’s score (p < (0).0001), and higher body mass indices (p = 0.022). Indication for induction due to preeclampsia increased the risk of a cesarean delivery (p = 0.008). Chorioamnionitis, post-partum complications and NICU admissions were greater in the women delivered by cesarean section. Conclusions: Indicated inductions which result in cesarean delivery were more likely in women with higher body mass indexes, lower parity, and Bishops scores, as well as preeclampsia.


Clinical and Vaccine Immunology | 2007

Detection of Human Papillomavirus Type 16-Specific T Lymphocytes by a Recombinant Vaccinia Virus-Based Enzyme-Linked Immunospot Assay

Kevin H. Kim; William W. Greenfield; Ezekiel Shotts; Mayumi Nakagawa

ABSTRACT Cell-mediated immunity, particularly that induced by T cells, is thought to have a key role in controlling infection. The enzyme-linked immunospot (ELISPOT) assay has been successfully adapted to detect T-cell immune response to a variety of pathogens. However, it still remains a challenge to detect antigen-specific T cells when the numbers of circulating cells are low, such as in a local cervical infection caused by genital human papillomavirus (HPV). The goal of this study was to develop a protocol for enhanced detection of HPV-specific CD8+ T cells by examining a number of the variables involved in performing an ELISPOT assay. Since blood samples consistently positive for HPV-specific T cells are difficult to obtain, previously described human papillomavirus type 16 (HPV16) E6 52-61 (FAFRDLCIVY)-specific T-cell clone cells (13) seeded in peripheral blood mononuclear cells from an HLA-B57-positive blood donor were used. The variables examined were the amounts of primary and secondary anti-gamma interferon antibodies, amounts of antigen-presenting monocytes and recombinant vaccinia virus expressing the HPV16 E6 protein, and amounts of exogenous cytokines added (recombinant human interleukin-2 [rhIL-2] and rhIL-7). The amounts of antigen-presenting monocytes, followed by the concentration of exogenous rhIL-2, had the most pronounced and significant effects in enhancing sensitivity of the ELISPOT assay. Blood samples from six patients being monitored for abnormal Pap smear results and from 12 healthy volunteers were examined using the enhanced conditions.


International Journal of Gynecological Pathology | 2007

Low-grade fibromyxoid sarcoma presenting clinically as a primary ovarian neoplasm: a case report.

Harry L. Winfield; Luis E. De Las Casas; William W. Greenfield; Alessandro D. Santin; Jesse K. McKenney


Journal of Lower Genital Tract Disease | 2010

A favorable clinical trend is associated with CD8 T-cell immune responses to the human papillomavirus type 16 e6 antigens in women being studied for abnormal pap smear results.

Mayumi Nakagawa; Sushil Gupta; Hannah N. Coleman; Matthew A. Sellers; Joseph A. Banken; William W. Greenfield


Cancer Immunology, Immunotherapy | 2012

CD4+ T-cell response against human papillomavirus type 16 E6 protein is associated with a favorable clinical trend

Kevin H. Kim; William W. Greenfield; Martin J. Cannon; Hannah N. Coleman; Horace J. Spencer; Mayumi Nakagawa

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Mayumi Nakagawa

University of Arkansas for Medical Sciences

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Hannah N. Coleman

University of Arkansas for Medical Sciences

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Horace J. Spencer

University of Arkansas for Medical Sciences

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Andréa M. Moerman-Herzog

University of Arkansas for Medical Sciences

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Shawna L. Stratton

University of Arkansas for Medical Sciences

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Wilbur C. Hitt

University of Arkansas for Medical Sciences

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Gordon Low

University of Arkansas for Medical Sciences

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Laura F. Hutchins

University of Arkansas for Medical Sciences

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Rita Vaughn

University of Arkansas for Medical Sciences

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Susanne K. Jeffus

University of Arkansas for Medical Sciences

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