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Dive into the research topics where Alexander F. Burnett is active.

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Featured researches published by Alexander F. Burnett.


Gynecologic Oncology | 2003

Radical vaginal trachelectomy and pelvic lymphadenectomy for preservation of fertility in early cervical carcinoma

Alexander F. Burnett; Lynda D. Roman; Anne T O’Meara; C.Paul Morrow

OBJECTIVE The aim of this study was to examine our experience with radical vaginal trachelectomy in women with early cervical cancers who desire to maintain fertility. METHODS Women who underwent radical vaginal trachelectomy with pelvic lymphadenectomy over a 6-year period are the basis of this report. Subjects were selected for this treatment on the basis of favorable cervical tumors and a desire to maintain fertility. All subjects were informed that this therapy did not represent standard treatment for early stage cervical cancer. Obstetrical and oncologic outcomes were evaluated. RESULTS Twenty-one women underwent this procedure. The median age was 30 years (range 23-41); 14 were nulligravid and 16 were nulliparous. Mean tumor diameter was 1.1 cm (range 0.3-3.0). Mean operative time was 318 min, with a mean blood loss of 293 cc, and average hospital stay was 3 days. Three patients had transient neuropathy postoperatively. No patient required laparotomy. Two patients had completion of radical vaginal hysterectomy for an inability to clear the cancer with trachelectomy and 1 had postoperative radiation for high-risk features on final pathology. With an average follow-up of 31.5 months, there have been no recurrences. Three women have become pregnant: 1 woman delivered twins at 24 weeks, 1 woman delivered a singleton at term, and 1 patient had rupture of membranes and chorioamnionitis at 20 weeks gestation. CONCLUSIONS Radical vaginal trachelectomy with pelvic lymphadenectomy permits preservation of fertility in selected patients. To date, with more than 150 cases reported in the literature, recurrence rates are comparable to those seen with radical hysterectomy.


Obstetrics & Gynecology | 1992

High frequency of latent and clinical human papillomavirus cervical infections in immunocompromised human immunodeficiency virus-infected women

Jacqueline C. Johnson; Alexander F. Burnett; Gerald D. Willet; Mary A. Young; Jay Doniger

In 32 human immunodeficiency virus (HIV)-infected women, routine gynecologic examination was performed with colposcopy and Papanicolaou smear; cervical swabs were collected for human papillomavirus (HPV) DNA screening and typing; and immune status was assessed by CD4 T-cell count. Dot blot analysis was specifically chosen for HPV DNA screening to detect only relatively substantial HPV DNA infections. Polymerase chain reaction analysis was used for precise DNA typing of dot blot-positive samples. The HPV data were assessed for immune status; a subject with a CD4 T-cell count below 200/microL was considered functionally immunosuppressed. The frequency of dot blot positivity was fivefold higher among immunocompromised (nine of ten) than relatively immunocompetent (four of 22) HIV-infected women. Moreover, four immunosuppressed women, compared with no immunocompetent subjects, had evidence of HPV DNA without signs of HPV-associated lesions by cytology or histology (ie, latent HPV infection). Furthermore, four of nine of the immunocompromised, compared with four of 21 immunocompetent, subjects had cervical intraepithelial neoplasia. These frequencies are high compared with those reported in the general population. Finally, HPV 18 was detected in five of the ten women with CD4 T-cell counts below 200/microL and in only one of the 22 with CD4 T-cell counts above that level. These results suggest that the normal immune system suppresses latent and clinical HPV cervical infections and that the efficiency of suppression may be HPV type-specific. Furthermore, impaired immune status, as reflected by CD4 T-cell count, is an important factor increasing the severity of HPV-induced cervical infections in this population.


British Journal of Cancer | 2005

Gene expression fingerprint of uterine serous papillary carcinoma: identification of novel molecular markers for uterine serous cancer diagnosis and therapy

Alessandro D. Santin; Fenghuang Zhan; Stefania Cané; Stefania Bellone; Michela Palmieri; Maria Thomas; Alexander F. Burnett; Juan J. Roman; Martin J. Cannon; John D. Shaughnessy; Sergio Pecorelli

Uterine serous papillary cancer (USPC) represents a rare but highly aggressive variant of endometrial cancer, the most common gynecologic tumour in women. We used oligonucleotide microarrays that interrogate the expression of some 10 000 known genes to profile 10 highly purified primary USPC cultures and five normal endometrial cells (NEC). We report that unsupervised analysis of mRNA fingerprints readily distinguished USPC from normal endometrial epithelial cells and identified 139 and 390 genes that exhibited >5-fold upregulation and downregulation, respectively, in primary USPC when compared to NEC. Many of the genes upregulated in USPC were found to represent adhesion molecules, secreted proteins and oncogenes, such as L1 cell adhesion molecule, claudin-3 and claudin-4, kallikrein 6 (protease M) and kallikrein 10 (NES1), interleukin-6 and c-erbB2. Downregulated genes in USPC included SEMACAP3, ras homolog gene family, member I (ARHI), and differentially downregulated in ovarian carcinoma gene 1. Quantitative RT–PCR was used to validate differences in gene expression between USPC and NEC for several of these genes. Owing to its potential as a novel therapeutic marker, expression of the high-affinity epithelial receptor for Clostridium perfringens enterotoxin (CPE) claudin-4 was further validated through immunohistochemical analysis of formalin-fixed paraffin-embedded specimens from which the primary USPC cultures were obtained, as well as an independent set of archival USPC specimens. Finally, the sensitivity of primary USPC to the administration of scalar doses of CPE in vitro was also demonstrated. Our results highlight the novel molecular features of USPC and provide a foundation for the development of new type-specific therapies against this highly aggressive variant of endometrial cancer.


Cancer Research | 2005

Treatment of chemotherapy-resistant human ovarian cancer xenografts in C.B-17/SCID mice by intraperitoneal administration of Clostridium perfringens enterotoxin.

Alessandro D. Santin; Stefania Cané; Stefania Bellone; Michela Palmieri; Eric R. Siegel; Maria Thomas; Juan J. Roman; Alexander F. Burnett; Martin J. Cannon; Sergio Pecorelli

Ovarian cancer remains the most lethal gynecologic malignancy in the United States. Although many patients with advanced-stage disease initially respond to standard combinations of surgical and cytotoxic therapy, nearly 90% develop recurrence and inevitably die from the development of chemotherapy-resistant disease. The discovery of novel and effective therapy against chemotherapy-resistant/recurrent ovarian cancer remains a high priority. Using expression profiling, we and others have recently found claudin-3 and claudin-4 genes to be highly expressed in ovarian cancer. Because these tight junction proteins have been described as the low- and high-affinity receptors, respectively, for the cytotoxic Clostridium perfringens enterotoxin (CPE), in this study we investigated the level of expression of claudin-3 and/or claudin-4 in chemotherapy-naive and chemotherapy-resistant primary human ovarian cancers as well as their sensitivity to CPE treatment in vitro. We report that 100% (17 of 17) of the primary ovarian tumors tested overexpress one or both CPE receptors by quantitative reverse transcription-PCR. All ovarian tumors showed a dose-dependent cytotoxic effect to CPE in vitro. Importantly, chemotherapy-resistant/recurrent ovarian tumors were found to express claudin-3 and claudin-4 genes at significantly higher levels when compared with chemotherapy-naive ovarian cancers. All primary ovarian tumors tested, regardless of their resistance to chemotherapeutic agents, died within 24 hours to the exposure to 3.3 microg/mL CPE in vitro. In addition, we have studied the in vivo efficacy of i.p. CPE therapy in SCID mouse xenografts in a highly relevant clinical model of chemotherapy-resistant freshly explanted human ovarian cancer (i.e., OVA-1). Multiple i.p. administration of sublethal doses of CPE every 3 days significantly inhibited tumor growth in 100% of mice harboring 1 week established OVA-1. Repeated i.p. doses of CPE also had a significant inhibitory effect on tumor progression with extended survival of animals harboring large ovarian tumor burdens (i.e., 4-week established OVA-1). Our findings suggest that CPE may have potential as a novel treatment for chemotherapy-resistant/recurrent ovarian cancer.


Journal of Minimally Invasive Gynecology | 2009

Robotic radical trachelectomy for preservation of fertility in early cervical cancer: case series and description of technique.

Alexander F. Burnett; Pamela J.B. Stone; L.A. Duckworth; Juan J. Roman

STUDY OBJECTIVE To present a case series of robotic radical trachelectomy for preservation of fertility in early cervical cancer. DESIGN Descriptive study. DESIGN Canadian Task Force Classification III. SETTING Tertiary referral center. PATIENTS Women with early cervical cancer who wish to maintain fertility potential. INTERVENTIONS Robotic radical trachelectomy with bilateral pelvic lymphadenectomy. The procedure also uses a cervical cerclage and permits preservation of the ascending branches of the uterine arteries to the uterus. MEASUREMENTS AND MAIN RESULTS Report of the technique, and operative and immediate postoperative complications. To date, 6 women have undergone robotic radical trachelectomy, with preservation of the uterine arteries in all patients. One patient underwent completion hysterectomy when the frozen section of the trachelectomy margin revealed inability to clear the cancer. Five women have maintained their fertility potential after the procedure. CONCLUSION Robotic radical trachelectomy is a feasible technique that permits radical removal of the cervix. Improved visualization with the robot and fine dissection permissible with the instrument facilitate this procedure.


Clinical Cancer Research | 2005

Human kallikrein 6: a new potential serum biomarker for uterine serous papillary cancer.

Alessandro D. Santin; Eleftherios P. Diamandis; Stefania Bellone; Antoninus Soosaipillai; Stefania Cané; Michela Palmieri; Alexander F. Burnett; Juan J. Roman; Sergio Pecorelli

Purpose: The discovery of novel biomarkers might greatly contribute to improve clinical management and outcomes in uterine serous papillary carcinoma (USPC), a highly aggressive variant of endometrial cancer. Experimental Design: Human kallikrein 6 (hK6) gene expression levels were evaluated in 29 snap-frozen endometrial biopsies, including 13 USPC, 13 endometrioid carcinomas, and 3 normal endometrial cells by real-time PCR. Secretion of hK6 protein by 14 tumor cultures, including 3 USPC, 3 endometrioid carcinoma, 5 ovarian serous papillary carcinoma, and 3 cervical cancers, was measured using a sensitive ELISA. Finally, hK6 concentration in 79 serum and plasma samples from 22 healthy women, 20 women with benign diseases, 20 women with endometrioid carcinoma, and 17 USPC patients was studied. Results:hK6 gene expression levels were significantly higher in USPC when compared with endometrioid carcinoma (mean copy number by real-time PCR, 1,927 versus 239, USPC versus endometrioid carcinoma; P < 0.01). In vitro hK6 secretion was detected in all primary USPC cell lines tested (mean, 11.5 μg/L) and the secretion levels were similar to those found in primary ovarian serous papillary carcinoma cultures (mean, 9.6 μg/L). In contrast, no hK6 secretion was detectable in primary endometrioid carcinoma and cervical cancer cultures. hK6 serum and plasma concentrations (mean ± SE) among normal healthy females (2.7 ± 0.2 μg/L), patients with benign diseases (2.4 ± 0.2 μg/L), and patients with endometrioid carcinoma (2.6 ± 0.2 μg/L) were not significantly different. In contrast, serum and plasma hK6 values in USPC patients (6.1 ± 1.1) were significantly higher than those in the noncancer group (P = 0.006), benign group (P = 0.003), and endometrioid carcinoma patients (P = 0.005). Conclusions: hK6 is highly expressed in USPC and is released in the plasma and serum of USPC patients. hK6 may represent a novel biomarker for USPC for monitoring early disease recurrence and response to therapy.


Current Opinion in Obstetrics & Gynecology | 2006

Radical trachelectomy with laparoscopic lymphadenectomy: review of oncologic and obstetrical outcomes.

Alexander F. Burnett

Purpose of review Fertility preservation in early cervical cancer by radical trachelectomy is gaining in acceptance as more cases are published in the literature. Controversies regarding technique and patient management are beginning to emerge as the procedure moves from being a new surgery to a part of standard of care. Recent findings As the number of cases reported in the literature increases, the effectiveness of radical trachelectomy for treating selected early-stage cancers continues to gain support. The survival of selected patients appears to be no different than that of similar patients treated with radical hysterectomy. Central recurrence in the residual cervix is a very rare event as long as the specimen has cleared the cancer. Patient selection criteria have evolved, and a more liberal use of the procedure is warranted. The effectiveness of trachelectomy in preserving fertility has now been demonstrated in series of 50 and 56 pregnancies occurring after the procedure. These larger series detail pregnancy outcomes and will be invaluable information to our patients who wish to maintain their ability to bear children. Subtle differences in technique between centers may account for different pregnancy outcomes. As more physicians begin to perform radical trachelectomy, controlled trials will be necessary to refine the procedure in order to continue to improve obstetric and oncologic outcomes. Summary Radical trachelectomy will continue to increase in popularity as more physicians become willing to learn the technique. It should routinely be offered to young women with early cervix cancer who desire to maintain their fertility.


Cancer Research | 2007

Local Administration of Interleukin-11 Ameliorates Intestinal Radiation Injury in Rats

Marjan Boerma; Junru Wang; Alexander F. Burnett; Alessandro D. Santin; Juan J. Roman; Martin Hauer-Jensen

Intestinal radiation injury is dose limiting during abdominal and pelvic radiotherapy and critical for the outcome after accidental whole-body radiation exposure. The multifunctional cytokine, interleukin-11 (IL-11), ameliorates the intestinal radiation response, but its clinical use is hampered by severe toxicity after systemic administration. This study addressed whether protection against intestinal radiation injury can be achieved by intraluminal administration of IL-11. Male rats underwent surgical transposition of a 4-cm small bowel loop to the scrotum. For repeated intraluminal drug administration, an ileostomy, proximal to the bowel loop in the scrotum, was created. The transposed intestinal loop was exposed to 5 Gy fractions on 9 consecutive days. Recombinant human IL-11 (rhIL-11; 2 mg/kg/d) or vehicle was given through the ileostomy from 2 days before until 2 weeks after irradiation. At 2 weeks, structural, cellular, and molecular aspects of intestinal radiation injury were assessed. rhIL-11 ameliorated structural manifestations of radiation enteropathy, including radiation injury score (6.5 +/- 0.6 in the vehicle group versus 4.0 +/- 0.3 in the IL-11 group; P = 0.001), mucosal surface area loss (0.2 +/- 0.1 versus 0.5 +/- 0.03; P < 0.0001), and intestinal wall thickening (842 +/- 66 microm versus 643 +/- 54 microm; P = 0.02), reduced postradiation transforming growth factor-beta overexpression, and reduced numbers of ED2-positive cells. Postirradiation mucosal mast cell numbers were partially restored by rhIL-11. These data show that local administration of rhIL-11 ameliorates early intestinal radiation injury and support further development of rhIL-11 to reduce manifestations of intestinal radiation injury in the clinic.


Current Pharmaceutical Design | 2005

Therapeutic Vaccines for Cervical Cancer: Dendritic Cell-Based Immunotherapy

Alessandro D. Santin; Stefania Bellone; Juan J. Roman; Alexander F. Burnett; Martin J. Cannon; Sergio Pecorelli

Human papillomavirus (HPV) infection represents the most important risk factor for the development of cervical dysplasia and cervical cancer. Several lines of evidence suggest that cell-mediated immune responses are important in controlling both HPV infections and HPV-associated neoplasia. Since HPV E6 and E7 oncoproteins are expressed in these lesions and are necessary for the maintenance of the malignant phenotype, these proteins might be potential tumor-specific target antigens for immunotherapy of cervical cancer. The gold standard treatment for locally advanced cervical cancer is primary radiation therapy combined with chemotherapy. A potential drawback of this potentially curative treatment is a profound and long lasting negative effect on the immune system. Treatment-induced immunosuppression combined with tumor-induced subversion of the immune system may therefore impose severe limitations on the efficacy of conventional vaccination strategies in late stage cervical cancer patients. The recognition of dendritic cells (DC) as powerful antigen-presenting cells capable of inducing primary T cell responses in vitro and in vivo, has recently generated widespread interest in DC-based immunotherapy of several human malignancies. Here, we review various therapeutic HPV vaccines being developed and implemented in human clinical trials, with a particular emphasis on the use of autologous DC pulsed with full-length HPV 16 or 18 E7 oncoproteins as a novel strategy to induce HPV E7-specific and tumor-specific T cell responses in cervical cancer patients following conventional treatment.


Clinical Cancer Research | 2007

Overexpression of Clostridium perfringens enterotoxin receptors claudin-3 and claudin-4 in uterine carcinosarcomas

Alessandro D. Santin; Stefania Bellone; Eric R. Siegel; Jesse K. McKenney; Maria Thomas; Juan J. Roman; Alexander F. Burnett; Germana Tognon; Elisabetta Bandiera; Sergio Pecorelli

Purpose: To evaluate the expression levels of claudin-3 and claudin-4, the low- and high-affinity receptors, respectively, for the cytotoxic Clostridium perfringens enterotoxin (CPE) in uterine carcinosarcomas and explore the potential for targeting these receptors in the treatment of this aggressive uterine tumor. Experimental Design: We analyzed claudin-3 and claudin-4 receptor expression at mRNA and protein levels in flash frozen and formalin-fixed, paraffin-embedded carcinosarcoma specimens. Recombinant CPE was used as a novel therapy against chemotherapy-resistant carcinosarcoma cell lines in vitro. The therapeutic effect of sublethal doses of CPE was studied in severe combined immunodeficient mouse xenografts harboring large s.c. carcinosarcomas. Results: All flash-frozen carcinosarcoma biopsies (12 of 12) and short-term carcinosarcoma cell lines evaluated overexpressed claudin-3 and claudin-4 by quantitative reverse transcription-PCR. Membranous immunoreactivity for claudin-4 protein expression was documented in 80% (20 of 25) of primary tumors and 100% (6 of 6) of the metastatic carcinosarcomas, whereas negligible staining was found in normal endometrial cells. Regardless of their resistance to chemotherapeutic agents, all short-term carcinosarcoma cell lines tested died within 1 h of exposure to 3.3 μg/mL of CPE in vitro. Intratumoral injections of well-tolerated doses of CPE in large s.c. carcinosarcoma xenografts led to large areas of tumor cell necrosis and tumor disappearance in all treated animals. Conclusions: Claudin-3 and claudin-4 receptors are highly overexpressed in carcinosarcoma. These proteins may offer promising targets for the use of CPE as a novel type-specific therapy against this biologically aggressive variant of endometrial cancer.

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Juan J. Roman

University of Arkansas for Medical Sciences

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Alessandro D. Santin

University of Arkansas for Medical Sciences

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Stefania Bellone

University of Arkansas for Medical Sciences

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Michela Palmieri

University of Arkansas for Medical Sciences

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Lynda D. Roman

University of Southern California

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Martin J. Cannon

University of Arkansas for Medical Sciences

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Laila I. Muderspach

University of Southern California

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C.Paul Morrow

University of Southern California

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Eric R. Siegel

University of Arkansas for Medical Sciences

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