Elizabeth L. Dickson

Tumor exosomes induce tunneling nanotubes in lipid raft-enriched regions of human mesothelioma cells.

Tunneling nanotubes (TnTs) are long, non-adherent, actin-based cellular extensions that act as conduits for transport of cellular cargo between connected cells. The mechanisms of nanotube formation and the effects of the tumor microenvironment and cellular signals on TnT formation are unknown. In the present study, we explored exosomes as potential mediators of TnT formation in mesothelioma and the potential relationship of lipid rafts to TnT formation. Mesothelioma cells co-cultured with exogenous mesothelioma-derived exosomes formed more TnTs than cells cultured without exosomes within 24-48 h; and this effect was most prominent in media conditions (low-serum, hyperglycemic medium) that support TnT formation (1.3-1.9-fold difference). Fluorescence and electron microscopy confirmed the purity of isolated exosomes and revealed that they localized predominantly at the base of and within TnTs, in addition to the extracellular environment. Time-lapse microscopic imaging demonstrated uptake of tumor exosomes by TnTs, which facilitated intercellular transfer of these exosomes between connected cells. Mesothelioma cells connected via TnTs were also significantly enriched for lipid rafts at nearly a 2-fold higher number compared with cells not connected by TnTs. Our findings provide supportive evidence of exosomes as potential chemotactic stimuli for TnT formation, and also lipid raft formation as a potential biomarker for TnT-forming cells.

Multiple-type human papillomavirus (HPV) infections: a cross-sectional analysis of the prevalence of specific types in 309,000 women referred for HPV testing at the time of cervical cytology.

Objectives To determine the frequency of multiple-type cervical human papillomavirus (HPV) infections, and whether any types are involved in multiple-type infections more or less frequently than might be expected if these infections occur randomly. Methods In this retrospective analysis of type-specific HPV testing, results from women 18 to 65 years old with samples collected between July 2007 and May 2011 were considered. Multivariate logistic regression analysis was used to model the presence of each of the 24 most prevalent HPV types, adjusting for one other HPV type, age, laboratory region, and age-by-region interactions. Results Human papillomavirus infection was present in 74,543 (24.1%) of 309,471 women and 65,492 (21.1%) were positive for one of the top 24 most prevalent HPV types. The most common HPV type was type 16, occurring in 4.1% of the entire sample. A total of 14,181 women were positive for 2 or more HPV types (4.6% of entire sample and 19.0% of HPV-positive sample). Two-way HPV type comparisons were analyzed. Types 52, 53, 81, and 83 were more likely to occur in multiple infections with other types; and types 16, 58, and 66 were less likely to occur in multiple infections with other types. Human papillomavirus types 72 and 81 have the strongest positive relationship (odds ratio, 5.2; 95% confidence interval, 3.6–7.4). Human papillomavirus types 33 and 66 have the strongest negative relationship (odds ratio, 0.4; 95% confidence interval, 0.2–0.6). Conclusions In this population, multiple-type HPV infections were present in 4.6% of all women. Our findings suggest that there may be both competitive and cooperative interactions between HPV types.

Cervical cytology and multiple type HPV infection: A study of 8182 women ages 31–65

OBJECTIVE The aim of this study is to determine the rates of single and multiple type human papillomavirus (HPV) infection in women in the United States ages 31-65 with known cervical cytology results. METHODS Type-specific HPV analyses were conducted using the first samples of women who had HPV typing performed by Access Genetics as part of cervical cancer screening between July 2007 and May 2011. Women 31-65years at testing with associated abnormal cytology results were included. The odds of abnormal cytology (compared to normal results) for multiple vs. single HPV infections were calculated for each cytology sub-type and odds ratios (OR) and 95% confidence intervals (CI) are reported. RESULTS The analysis included 8182 women. The majority (67.7%) had ASCUS cervical cytology. A total of 329 (4.0%) were positive for 2 or more HPV types. For all cervical cytology subtypes considered (ASCUS, ASCUS-H, LSIL or HSIL), women with multiple type infections were more likely to have abnormal cytology (compared to normal cytology) with the highest OR associated with HSIL (OR 1.81 (1.26-2.60)). When analyzing HPV type 16 alone, women with multiple type infections were more likely to have abnormal cytology, with the highest OR associated with HSIL cytology (OR 2.98 (1.57-5.64)). Few women had HPV type 18 infections and no results reached statistical significance. Results based on phylogenic family organization focusing on the alpha 9 phylogenic family showed similar results as HPV type 16. CONCLUSIONS Women ages 31-65 with multiple type HPV infections were more likely to have abnormal cytology than those with single HPV type infections.

Tunneling nanotube formation is stimulated by hypoxia in ovarian cancer cells

In this study, we demonstrated that hypoxic conditions stimulated an increase in tunneling nanotube (TNT) formation in chemoresistant ovarian cancer cells (SKOV3, C200). We found that suppressing the mTOR pathway using either everolimus or metformin led to suppression of TNT formation in vitro, verifying TNTs as a potential target for cancer-directed therapy. Additionally, TNT formation was detected in co-cultures including between platinum-resistant SKOV3 cells, between SKOV3 cells and platinum-chemosensitive A2780 cells, and between SKOV3 cells cultured with benign ovarian epithelial (IOSE) cells; these findings indicate that TNTs are novel conduits for malignant cell interactions and tumor cell interactions with other cells in the microenvironment. When chemoresistant C200 and parent chemosensitive A2780 cells were co-cultured, chemoresistant cells displayed a higher likelihood of TNT formation to each other than to chemosensitive malignant or benign epithelial cells. Hypoxia-induced TNT formation represents a potential mechanism for intercellular communication in ovarian cancer and other forms of invasive refractory cancers.

Assessment of palliative care training in gynecologic oncology: A gynecologic oncology fellow research network study

OBJECTIVE Palliative care is recognized as an important component of oncologic care. We sought to assess the quality/quantity of palliative care education in gynecologic oncology fellowship. METHODS A self-administered on-line questionnaire was distributed to current gynecologic oncology fellow and candidate members during the 2013 academic year. Descriptive statistics, bivariate and multivariate analyses were performed. RESULTS Of 201 fellow and candidate members, 74.1% (n=149) responded. Respondents were primarily women (75%) and white (76%). Only 11% of respondents participated in a palliative care rotation. Respondents rated the overall quality of teaching received on management of ovarian cancer significantly higher than management of patients at end of life (EOL), independent of level of training (8.25 vs. 6.23; p<0.0005). Forty-six percent reported never being observed discussing transition of care from curative to palliative with a patient, and 56% never received feedback about technique regarding discussions on EOL care. When asked to recall their most recent patient who had died, 83% reported enrollment in hospice within 4 weeks of death. Fellows reporting higher quality EOL education were significantly more likely to feel prepared to care for patients at EOL (p<0.0005). Mean ranking of preparedness increased with the number of times a fellow reported discussing changing goals from curative to palliative and the number of times he/she received feedback from an attending (p<0.0005). CONCLUSIONS Gynecologic oncology fellow/candidate members reported insufficient palliative care education. Those respondents reporting higher quality EOL training felt more prepared to care for dying patients and to address complications commonly encountered in this setting.

Gonadal Dysgenesis and Gynecologic Cancer

BACKGROUND: Gonadal dysgenesis encompasses a variety of sexual differentiation disorders. Within this population of patients, there is an increased risk of gonadal tumor formation. CASES: In this case series of three patients, two with Swyers syndrome (complete gonadal dysgenesis) and one with mosaic Turners syndrome, three separate histologic subtypes of tumors were identified: dysgerminoma, seminoma, and gonadoblastoma. The patients with dysgerminoma and seminoma had regular menses and were without recurrent disease. We recommend that the patient with gonadoblastoma start on hormone therapy. CONCLUSION: Once the diagnosis of gonadal dysgenesis is made, prophylactic gonadectomy should be performed owing to the probability of malignant transformation. These patients illustrate the potential different presentations with gonadal dysgenesis and the importance of complete evaluation of patients with primary amenorrhea.

Potato Spindle Tuber Viroid-infected Tissues Contain RNA Complementary to the Entire Viroid

Summary Potato spindle tuber viroid (PSTV) RNA, labelled in vitro with 125I, was hybridized in solution to RNA prepared from uninfected and PSTV-infected Rutgers tomato plants and suspension cultures. Following hybridization to RNA from infected plants, 125I-labelled PSTV was converted from its single-stranded form to double-stranded RNA; this conversion did not occur to a significant extent when the 125I-labelled PSTV was incubated with RNA from uninfected tomato plants under identical conditions. Following fractionation of RNA from PSTV-infected tissue with 2 m-LiCl and chromatography on cellulose CF11 columns, the RNA species which hybridizes with the PSTV probe was found to be enriched in those fractions which are also enriched for double-stranded RNA. Fingerprint analysis of hybridized 125I-labelled PSTV following recovery from the hybrids demonstrated that all regions of the viroid are represented in the complementary strands present in these RNA preparations.

Results of Introducing a Rapid Recovery Program for Total Abdominal Hysterectomy

Objective: To review the impact of implementing a rapid recovery protocol (RRP) for patients undergoing abdominal hysterectomy. Setting: Metropolitan teaching hospital. Population: Women undergoing abdominal hysterectomy for non-malignant indications. Methods: We conducted a retrospective review of consecutive cases performed during study periods before and after the introduction of an elective rapid recovery program emphasizing regional anesthesia. To control for universal improvements in medical practice, charts from a comparable local hospital without an RRP were also reviewed. Results: 400 charts were reviewed and 366 cases met inclusion criteria and had sufficient information. Patients were well matched for demographic and medical variables between the study periods and between the institutions. The median length of stay (LOS) fell dramatically from 3 (range 1–12) days prior to RRP introduction to 1 (range 1–17) day after RRP (p < 0.001). LOS among patients at the ‘control’ institution remained unchanged at 3 days during the same time frame, indicating that external pressures contributed minimally to the observed changes. There were no significant differences in estimated blood loss, duration of surgery, or complication rate between the groups in either time period. Conclusions: Introducing a rapid recovery program was associated with shorter hospitalization and did not appear to compromise surgical outcome.

The effect of anesthesia choice on post-operative outcomes in women undergoing exploratory laparotomy for a suspected gynecologic malignancy

OBJECTIVE To determine how anesthesia choice in women undergoing laparotomy for gynecologic malignancy affects pain control and narcotic use. METHODS This is a retrospective study of women who underwent laparotomy for suspected gynecologic malignancy from May 2012 to January 2013. Patients were categorized into one of three groups: 1) patient controlled analgesia (PCA); 2) PCA+transversus abdominis plane block (TAP); and 3) patient-controlled epidural analgesia (PCEA). Mean narcotic use and patient reported pain scores were compared. RESULTS The analysis includes 112 women (44 PCA, 30 TAP, 38 PCEA). Intraoperative factors were not different between groups with the exception of a significant difference in the rate of intra-operative complications (p=0.020), with lower rates in the PCEA group. The groups differed in intravenous narcotic use in each of the first three postoperative days (day 0: p=0.014; day 1: p<0.0001; day 2: p=0.048), with patients in the TAP group using the least on day 0 and those in the PCEA group using less on postoperative days 1 and 2. In addition, the PCEA group reported lower pain scores on postoperative days 1 and 2 (day 1: p=0.046; day 2: p=0.008). CONCLUSIONS The use of patient controlled epidural anesthesia after laparotomy for gynecologic malignancy is associated with decreased IV and PO narcotic use and improved pain control without increasing complications or length of hospital stay. Further investigation with prospective randomized trials is warranted to elucidate the optimal post-operative pain management technique.

Recent trends in type-specific HPV infection rates in the United States

SUMMARY This study examined recent trends in type-specific HPV infection rates in women referred for HPV typing as part of cervical cancer screening in the United States. HPV analyses were performed from March 2004 to March 2011. Women were aged 21-65 years at testing. The 18 most prevalent HPV types were analysed. Type-specific HPV infection rates were estimated in 3-month blocks. Lowess smoothing was used to examine time trends in infection rates for each HPV type, both combined, and separated by age group (younger women 21-30 years, older women 31-64 years). A total of 220914 women were included in the final analysis. The number of HPV tests performed on the younger age group increased, with the number of HPV infections and multiple type HPV infections decreasing. When separated by HPV type-specific analysis, the majority of HPV infection rates decreased; however, HPV types 61 and 83 increased. When analysing the older age group, there was a marked increase of the number of HPV tests. Overall, the rates of any HPV infection, as well as multiple type infections, were lower compared to the younger age group. The change in type-specific HPV rates in the older age group was minimal, with many rates remaining the same. In this population of women, overall rates of HPV infection decreased, while the number of HPV tests increased. Younger women had a more marked decrease in HPV infection rates, while for older women type-specific HPV infection rates appear consistent.