Hydrophobic residues in S1 modulate enzymatic function and voltage sensing in voltage-sensing phosphatase.

The voltage-sensing domain (VSD) is a four-helix modular protein domain that converts electrical signals into conformational changes, leading to open pores and active enzymes. In most voltage-sensing proteins, the VSDs do not interact with one another, and the S1-S3 helices are considered mainly scaffolding, except in the voltage-sensing phosphatase (VSP) and the proton channel (Hv). To investigate its contribution to VSP function, we mutated four hydrophobic amino acids in S1 to alanine (F127, I131, I134, and L137), individually or in combination. Most of these mutations shifted the voltage dependence of activity to higher voltages; however, not all substrate reactions were the same. The kinetics of enzymatic activity were also altered, with some mutations significantly slowing down dephosphorylation. The voltage dependence of VSD motions was consistently shifted to lower voltages and indicated a second voltage-dependent motion. Additionally, none of the mutations broke the VSP dimer, indicating that the S1 impact could stem from intra- and/or intersubunit interactions. Lastly, when the same mutations were introduced into a genetically encoded voltage indicator, they dramatically altered the optical readings, making some of the kinetics faster and shifting the voltage dependence. These results indicate that the S1 helix in VSP plays a critical role in tuning the enzyme's conformational response to membrane potential transients and influencing the function of the VSD.

Quality Initiative to Improve Compliance With Perioperative Anticoagulation.

PURPOSE: Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in gynecologic oncology surgical patients. Many centers use neuraxial analgesia (NA), which affects the timing of prophylactic anticoagulation. In 2012, we determined that the rate of VTE in patients undergoing laparotomy with NA was higher than in those who received alternative pain control. In addition, compliance with preoperative anticoagulation guidelines was only 40%. We undertook a quality initiative (QI) project to increase compliance to 80% in NA cases and maintain 90% in non-NA cases. METHODS: A multidisciplinary working group designed and deployed a QI intervention bundle. Compliance was defined as the receipt of a prophylactic dose of anticoagulant within 1 hour after NA or before skin incision regardless of anesthesia type. Data were abstracted from the medical record after the study period. Cases from the year before QI were used for comparison. Primary outcome was compliance and secondary outcome was the rate of VTE. RESULTS: One hundred women were treated under the QI project and 182 historical cases (HCs) were used for comparison. Overall compliance improved (96% QI v 73% HC; P < .001). This difference was marked in cases with NA (95% QI v 40% HC; P < .001) and remained stable in non-NA cases (97% QI v 91% HC; P = .29). The overall rate of VTE, independent of anesthesia type, remained unchanged (2.1% HC v 0% QI; P = .3). CONCLUSION: Relatively simple and inexpensive initiatives to improve routine processes within the surgical pathway are feasible and attract staff participation. Such efforts are likely to translate into greater levels of patient safety.

Endometrial cancer in an increasingly obese population: Exploring alternative options when surgery may not cut it.

OBJECTIVES: The study objectives were to describe outcomes of obese patients with early endometrial cancer following primary non-surgical treatment, assess predictors of response, and estimate the increased surgical risk for these women. METHODS: Retrospective chart review identified women with early stage endometrial cancer at a single institution with BMI ≥ 30 kg/m2 who did not undergo surgery as primary treatment modality due to obesity and medical co-morbidities. Clinicopathologic factors were abstracted, characteristics of responders vs. non-responders compared and the National Surgical Quality Improvement Program (NSQIP) surgical risk calculator utilized to quantify surgical risks. RESULTS: Fifty-one patients were identified, with a mean BMI of 49.0 kg/m2. The NSQIP calculator predicted a significantly higher complication rate for our cohort compared to the expected average risk for hysterectomy (18.8% vs 7.2%, p < .0001). The majority of patients were treated with radiation alone (49%), followed by hormone therapy (45.1%). Response rates were 38.1% for women treated with hormones and 63.6% in the radiation group (p = .063). No significant differences were identified between responders and non-responders with regard to NSQIP scores, BMI, co-morbidities or age. Among those with persistent or progressive disease, 87.5% responded to secondary treatment. Only one death was from cancer progression. Two individuals died following treatment complications (one surgical, one chemotherapy); the remaining twelve deaths were due to pre-existing co-morbidities. CONCLUSIONS: Hormone and radiation therapy are both viable options for obese patients deemed to have too significant risk of surgical complications. Pursuing surgical intervention in this population may do more harm than good.

Nonoperative management of atypical endometrial hyperplasia and grade 1 endometrial cancer with the levonorgestrel intrauterine device in medically ill post-menopausal women.

OBJECTIVE: To assess the endometrial response rates to treatment with the levonorgestrel intrauterine device in post-menopausal women with atypical hyperplasia/endometrial intraepithelial neoplasia and grade 1 endometrioid (AH/EC) endometrial carcinoma who are not surgical candidates. METHODS: Chart review was undertaken of patients with AH/EC who underwent levonorgestrel intrauterine device insertion by a gynecologic oncologist within two academic health systems between 2002 and 2013. When available, tissue blocks were evaluated with immunohistochemical staining for progesterone receptor expression. RESULTS: A total of 41 patients received treatment for AH/EC with the levonorgestrel intrauterine device. Follow up sufficient to assess response occurred in 36 women (88%). Complete response was documented in 18 of 36 women (50%), no response in 8 patients (22%), partial response in 3 women (8%) and progression of disease in 7 patients (19%). Four of 18 patients with complete response (22%) later experienced relapse of hyperplasia or cancer. Four patients (10%) died during the study period: none had evidence of metastatic disease and 1 of the 4 woman died of perioperative complications following hysterectomy for stage I disease. Patients responding to treatment had significantly lower progesterone receptor expression on post-treatment biopsies. CONCLUSIONS: Intrauterine levonorgestrel is a viable treatment option for post-menopausal women with AH/EC who are poor candidates for standard surgical management. The response rate in this series is similar to published reports in premenopausal patients and includes cases of disease recurrence following conversion to benign endometrium.

Metastatic papillary serous uterine cancer presenting as a rash.

BACKGROUND: We report diagnosis and management of stage IV papillary serous uterine cancer with initial clinical presentation as a skin rash. CASE: A 62-year-old postmenopausal female developed an erythematous rash beginning on her right lower abdomen and progressively spreading to her left abdomen, vulva, and neck. After a trial of antibiotic treatment, biopsy of left neck and right thigh skin nodules revealed papillary serous carcinoma. Abdominopelvic tomography revealed endometrial thickening and a 5 cm left adnexal mass. Subsequent endometrial biopsy also revealed papillary serous carcinoma, with pathology similar to that of the skin lesions. She received 6 cycles of carboplatin and paclitaxel chemotherapy with improvement of her skin lesions and overall performance status. However, her CA-125 level continued to rise and she was treated with single-agent carboplatin with progression of both her internal and cutaneous disease. She was transitioned to hospice with palliative radiation and died 2 months after discontinuing chemotherapy, 10 months after presentation. CONCLUSION: Cutaneous metastasis is a rare presentation of metastatic uterine cancer. Treatment with chemotherapy may result in a positive response and should be considered.

Metabolic vulnerabilities in endometrial cancer.

Women with metabolic disorders, including obesity and diabetes, have an increased risk of developing endometrial cancer. However, the metabolism of endometrial tumors themselves has been largely understudied. Comparing human endometrial tumors and cells with their nonmalignant counterparts, we found that upregulation of the glucose transporter GLUT6 was more closely associated with the cancer phenotype than other hallmark cancer genes, including hexokinase 2 and pyruvate kinase M2. Importantly, suppression of GLUT6 expression inhibited glycolysis and survival of endometrial cancer cells. Glycolysis and lipogenesis were also highly coupled with the cancer phenotype in patient samples and cells. To test whether targeting endometrial cancer metabolism could be exploited as a therapeutic strategy, we screened a panel of compounds known to target diverse metabolic pathways in endometrial cells. We identified that the glycolytic inhibitor, 3-bromopyruvate, is a powerful antagonist of lipogenesis through pyruvylation of CoA. We also provide evidence that 3-bromopyruvate promotes cell death via a necrotic mechanism that does not involve reactive oxygen species and that 3-bromopyruvate impaired the growth of endometrial cancer xenografts.

Repeated testing by use of culture and PCR assay to detect Tritrichomonas foetus carrier bulls in an infected Nebraska herd.

OBJECTIVE: To compare methods for identification of bulls that were carriers for Tritrichomonas foetus during an outbreak on a large beef ranch and determine whether the percentage of nonpregnant cows was associated with the percentage of bulls infected with T foetus. DESIGN: Epidemiological study. ANIMALS: 121 Angus and Hereford bulls (1.5 to 6 years old) and 2,960 Angus-cross cows (2.5 to 14 years old) managed as 5 herds on a Nebraska beef ranch. PROCEDURES: 3 sequential preputial scrapings collected from the bulls at 12- to 27-day intervals were cultured, and cultures were examined for live T foetus daily for 5 days. On day 5, aliquots of the culture fluid were tested by means of T foetus-specific gel and real-time PCR assays. Cows were tested for pregnancy by means of rectal palpation. RESULTS: For 361 preputial scrapings obtained from 121 bulls, results of culture and gel PCR assay were in close agreement. The real-time PCR assay had similar sensitivity to culture and the gel PCR assay but generated more false-positive results. Twenty-four of the 121 (19.8%) bulls were identified as infected with T foetus. For the 5 ranch herds, there was a positive linear correlation between percentage of infected bulls (range, 0% to 40%) and percentage of nonpregnant cows (range, 8.3% to 19.2%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a combination of culture and the gel PCR assay performed on 3 sequential preputial scrapings was the best method for identifying bulls that were carriers for T foetus during this herd outbreak.

Effects of horizontal whole-body vibration and standing posture on activity interference.

Standing people are exposed to whole-body vibration in many environments. This paper investigates the effects of horizontal whole-body vibration and standing posture on task performance. Sixteen participants were exposed to random vibration (up to 4 Hz) whilst performing a timed pegboard task in two standing postures. Objective and subjective indicators of performance were used. Time taken to complete the task increased progressively with increases in vibration magnitude. The fore-and-aft posture generally showed greater performance decrements and postural interruptions (>1.0 ms(-2) root mean square) than the lateral. For both postures, performance was better during y-axis vibration than during x-axis vibration. Subjective ratings showed similar trends to time data. Impairments due to dual axis exposure were well predicted using root sum of squares calculations based on single axis components. These results indicate that best performance for those standing in moving environments will be achieved if individuals adopt a lateral posture with the most severe vibration in the y-axis. STATEMENT OF RELEVANCE: People have a need to work during transportation, either working for the transport provider or as a passenger. All modes of transport result in travellers being exposed to horizontal motion. This study demonstrates that task disturbance is affected by the orientation of the standing person to the vibration and, therefore, vehicle layouts can be optimised.