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Featured researches published by John L. Clayton.


Urology | 2002

Morphologic and clinical significance of multifocal prostate cancers in radical prostatectomy specimens.

Alphaeus M. Wise; Thomas A. Stamey; John E. McNeal; John L. Clayton

OBJECTIVES To examine the histologic details of small, independent cancers compared with the largest (index) tumor and their impact on prostate-specific antigen (PSA) failure in 486 men treated only by radical retropubic prostatectomy (RRP). METHODS The tumor volume and percentage of Gleason grade 4/5 carcinoma were recorded in 3-mm step sections. Univariate statistics were calculated for the largest, total (largest plus smaller cancers), and smaller tumor volumes, number of independent foci, patient age, and follow-up. Cox hazards model determined the relative importance of all variables in relation to failure. RESULTS The mean index tumor volume was 4.16 cm3; smaller cancer volumes averaged 0.63 cm3. The index cancer volume was gaussian in distribution; smaller tumor volumes were highly skewed toward 234 carcinomas less than 0.5 cm3. Only 17% of all cases had one carcinoma. The Cox model showed similar hazard rates of PSA failure for both the index (3.43) and the total cancer (3.74) volumes. The hazard rate for the presence of any Gleason grade 4/5 carcinoma was 6.5. As the numbers of smaller tumors increased, the PSA cure rates improved. CONCLUSIONS The PSA failure rates (hazard ratios) were similar for the index tumor and the index plus smaller cancers, confirming that predictive estimates only need to measure the largest carcinoma. The greater the number of lesser cancers, the smaller the size of the index cancer. The extraordinary multiplicity of these small independent cancers in 3-mm step sections may explain the poor correlation between six or more biopsies with the index cancer in radical prostatectomy specimens.


Transplantation | 2005

High body mass index and short- and long-term renal allograft survival in adults

Nader N. Massarweh; John L. Clayton; Craig A. Mangum; Sander Florman; Douglas P. Slakey

Background. The effect of recipient obesity on kidney allograft survival remains enigmatic. The purpose of this study was to evaluate the effect of donor and recipient body mass index on graft survival. Methods. Retrospective study of 193 consecutive, adult renal transplants, with at least six months follow-up (mean 24±14.1 months). Patients were divided into two groups based upon body mass index (BMI), [weight (kg)/height (m2)]: normal (<30.0, n=137) and obese (≥30.0, n=56). Endpoints were graft loss, defined as either total loss of graft function (return to dialysis) or patient death with a functional graft. Unadjusted and adjusted multivariate analysis techniques, including Kaplan-Meier and Cox proportional hazards regression were used. Results. Individuals with a BMI ≥30 were not more likely to experience graft loss (O.R. 0.93, 95% C.I. 0.50, 1.72). Rates of acute rejection were not increased in obese recipients. While mortality was not increased in the BMI > 30 group, morbidity, especially surgical, had an increased incidence. The ratio of recipient to donor BMI did not influence graft survival. Conclusion. Obese recipients (BMI ≥30.0) were not at increased risk for graft failure. Additionally, matching donor and recipient BMIs would not appear to substantially improve transplant outcome. Obese recipients do have increased posttransplant morbidity and risk all the known health consequences associated with obesity. Careful evaluation and clinical management of obese patients allows for successful kidney transplantation with results equivalent to normal BMI patients.


Journal of Clinical Microbiology | 2002

Detection of Human Papillomavirus DNA in Urine Specimens from Human Immunodeficiency Virus-Positive Women

Joeli A. Brinkman; W.Elizabeth Jones; Ann M. Gaffga; Jonathan A. Sanders; Anil K. Chaturvedi; Joseph Slavinsky; John L. Clayton; Jeanne Dumestre; Michael E. Hagensee

ABSTRACT Human immunodeficiency virus (HIV)-positive women may represent one of the fastest-growing populations at risk for acquiring cervical cancer and thus require frequent screening. The purpose of the present studies was to validate a PCR-based urine assay by comparing detection and genotyping of human papillomavirus (HPV) DNA in urine samples and matching cervical swab specimens of HIV-positive women. Despite a difference in amplifiability, the prevalence of any HPV genotype (58% for the cervical swab specimens and 48% for the urine specimens) was not significantly different in this population. The levels of concordance were 70, 71, and 78% for detection of any HPV type, any high-risk HPV type, or any low-risk HPV type in the two specimen types, respectively. While instances of discordant detection were greater for the cervical swab specimens than for the urine specimens, this was not statistically significant. The distributions of HPV genotypes were similar in the cervix and the urine for the majority of types examined. Importantly, detection of HPV DNA in urine was associated with an abnormal Papanicolaou smear to the same extent that detection of HPV DNA in a cervical swab specimen was. These data provide preliminary support for the proposal to use urine testing as a primary or secondary screening tool for cervical cancer in HIV-positive women or as an epidemiological tool. Additional studies with larger sample sizes must be conducted in order to further verify these findings.


Sexually Transmitted Diseases | 2002

Older partners not associated with recurrence among female teenagers infected with Chlamydia trachomatis

Patricia Kissinger; John L. Clayton; Megan E. O'brien; Charlotte K. Kent; William L. H. Whittington; M. Kim Oh; Dennis Fortenberry; Susan E. Hillis; Billy Litchfield; Gail Bolan; H. Hunter Handsfield; Thomas A. Farley; Stuart M. Berman

Background Chlamydia trachomatis– infected female teenagers with older partners may be less likely to discuss the infection with their partner(s) and to use condoms and therefore may be more likely to get reinfected. Goal To determine if C trachomatis–infected female teenagers with older partners were more likely to be reinfected than those with same-aged partners. Study Design Females aged 14 years to 18 years who had uncomplicated chlamydial infection, were nonpregnant, attended clinics in five United States cities from June 1995 to May 1997, completed treatment, and resumed sexual activity were observed at 1 and 4 months for interim history and retesting. Results Of 225 women studied, 73.3% were black, 34.5% had at least one partner who was 3 or more years older during follow-up, 51.6% reported using a condom at the last sex act with all partners, 13.8% had a recurrent infection, and 47.4% reported they were certain that all of their baseline partners were treated. Partner age was not associated with condom use, certainty of partners’ taking medication, or recurrent infections after adjustment for visit. Conclusions Older partners, accounting for approximately one third of all partners, did not increase the risk of reinfection. Given the high risk for recurrence, follow-up testing and enhanced efforts to ensure partner treatment are appropriate for all young women with chlamydial infections.


Surgery | 2001

NF-κB–mediated chemoresistance in breast cancer cells

Christopher B. Weldon; Matthew E. Burow; Kevin W. Rolfe; John L. Clayton; Bernard M. Jaffe; Barbara S. Beckman


Surgery | 2002

Identification of mitogen-activated protein kinase kinase as a chemoresistant pathway in MCF-7 cells by using gene expression microarray.

Christopher B. Weldon; Ali B. Scandurro; Kevin W. Rolfe; John L. Clayton; Steven Elliott; Nancy N. Butler; Lilia I. Melnik; Jawed Alam; John A. McLachlan; Bernard M. Jaffe; Barbara S. Beckman; Matthew E. Burow


International Journal of Oncology | 2004

Sensitization of apoptotically-resistant breast carcinoma cells to TNF and TRAIL by inhibition of p38 mitogen-activated protein kinase signaling.

Christopher B. Weldon; Amanda P. Parker; Daniel Patten; Steven Elliott; Yan Tang; Daniel E. Frigo; Christine M. Dugan; Erin L. Coakley; Nancy N. Butler; John L. Clayton; Jawed Alam; Tyler J. Curiel; Barbara S. Beckman; Bernard M. Jaffe; Matthew E. Burow


Journal of Surgical Research | 2005

Multicenter Construct Validity for Southwestern Laparoscopic Videotrainer Stations

James R. Korndorffer; John L. Clayton; Seifu T. Tesfay; William C. Brunner; Rafael Sierra; J. Bruce Dunne; Daniel B. Jones; Robert V. Rege; Cheri L. Touchard; Daniel J. Scott


Journal of Clinical Microbiology | 2000

Comparison of Three Assays for Cytomegalovirus Detection in AIDS Patients at Risk for Retinitis

Pornthep Wattanamano; John L. Clayton; Jeffrey J. Kopicko; Patricia Kissinger; Steven Elliot; Christine Jarrott; Setlur Rangan; Mark A. Beilke


Surgery | 2004

Regulation of estrogen-mediated cell survival and proliferation by p160 coactivators.

Christopher B. Weldon; Steven Elliott; Yun Zhu; John L. Clayton; Tyler J. Curiel; Bernard M. Jaffe; Matthew E. Burow

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Bernard M. Jaffe

SUNY Downstate Medical Center

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Jawed Alam

Ochsner Medical Center

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Joseph Slavinsky

University Medical Center New Orleans

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