Operating Room Airborne Microbial Load: Nonscrubbed Staff Apparel Matters.

BACKGROUND: Infection is a leading cause of total joint arthroplasty failure. In previous studies, we found correlations between the level of contamination, concentrations of airborne particles, and the number of staff present. In this study, we focused on the apparel of nonscrubbed operating room (OR) staff to elucidate their contribution to the airborne microbial load. METHODS: We compared hospital-laundered scrubs to disposable coveralls using 2 methods. (1) Participants entered an isolation chamber with a controlled environment and completed tasks for 1 hour wearing both the approved and alternative OR attire. Settle plates collected viable contaminants that were shed by the participants during testing. (2) Lab members conducted standardized maneuvers in a functional OR that simulated typical movements of the nurse, anesthesiologist, implant representative, and entering/exiting staff. An airborne particle counter and settle plates were positioned throughout the OR. After 1 hour, the staff changed apparel and repeated the test. Each session of both phases consisted of 2 tests by the same individuals on the same day. RESULTS: There was approximately a 10-fold difference in the settlement rate of viable particles between groups when employing the isolation chamber. The settle rate for scrubs was 5,519 ± 1,381 colony forming units (CFUs)/m2/h, while the settle rate for coveralls was 505 ± 55 CFUs/m2/h (P = .008). During testing in the OR, 218.7 ± 35 CFUs/m2/h were captured for scrubs, compared with 50.5 ± 13 CFUs/m2/h for the coverall (P < .01). The concentration of airborne particles collected for scrubs was 4,952.1 ± 495 particles/m3 and 1,065 ± 53 particles/m3 for the coveralls (P < .01). This was a 77% and 79% reduction for both measures, respectively. CONCLUSIONS: The open nature of standard scrubs allows contaminated particles to escape into the OR environment, whereas the one-piece design of the coveralls restricts pathways of escape. The results of this study may be helpful when developing hospital infection prevention policies.

Host obesity alters the ovarian tumor immune microenvironment and impacts response to standard of care chemotherapy.

BACKGROUND: The majority of women with epithelial ovarian cancer (OvCa) are diagnosed with metastatic disease, resulting in a poor 5-year survival of 31%. Obesity is a recognized non-infectious pandemic that increases OvCa incidence, enhances metastatic success and reduces survival. We have previously demonstrated a link between obesity and OvCa metastatic success in a diet-induced obesity mouse model wherein a significantly enhanced tumor burden was associated with a decreased M1/M2 tumor-associated macrophage ratio (Liu Y et al. Can, Res. 2015; 75:5046-57). METHODS: The objective of this study was to use pre-clinical murine models of diet-induced obesity to evaluate the effect of a high fat diet (HFD) on response to standard of care chemotherapy and to assess obesity-associated changes in the tumor microenvironment. Archived tumor tissues from ovarian cancer patients of defined body mass index (BMI) were also evaluated using multiplexed immunofluorescence analysis of immune markers. RESULTS: We observed a significantly diminished response to standard of care paclitaxel/carboplatin chemotherapy in HFD mice relative to low fat diet (LFD) controls. A corresponding decrease in the M1/M2 macrophage ratio and enhanced tumor fibrosis were observed both in murine DIO studies and in human tumors from women with BMI > 30. CONCLUSIONS: Our data suggest that the reported negative impact of obesity on OvCa patient survival may be due in part to the effect of the altered M1/M2 tumor-associated macrophage ratio and enhanced fibrosis on chemosensitivity. These data demonstrate a contribution of host obesity to ovarian tumor progression and therapeutic response and support future combination strategies targeting macrophage polarization and/or fibrosis in the obese host.

In vivo selection of highly metastatic human ovarian cancer sublines reveals role for AMIGO2 in intra-peritoneal metastatic regulation.

The majority of women with ovarian cancer are diagnosed with metastatic disease, therefore elucidating molecular events that contribute to successful metastatic dissemination may identify additional targets for therapeutic intervention and thereby positively impact survival. Using two human high grade serous ovarian cancer cell lines with inactive TP53 and multiple rounds of serial in vivo passaging, we generated sublines with significantly accelerated intra-peritoneal (IP) growth. Comparative analysis of the parental and IP sublines identified a common panel of differentially expressed genes. The most highly differentially expressed gene, upregulated by 60-65-fold in IP-selected sublines, was the type I transmembrane protein AMIGO2. As the role of AMIGO2 in ovarian cancer metastasis remains unexplored, CRISPR/Cas9 was used to reduce AMIGO2 expression, followed by in vitro and in vivo functional analyses. Knockdown of AMIGO2 modified the sphere-forming potential of ovarian cancer cells, reduced adhesion and invasion in vitro, and significantly attenuated IP metastasis. These data highlight AMIGO2 as a new target for a novel anti-metastatic therapeutic approach aimed at blocking cohesion, survival, and adhesion of metastatic tumorspheres.

The Jak2V617F oncogene associated with myeloproliferative diseases requires a functional FERM domain for transformation and for expression of the Myc and Pim proto-oncogenes.

The V617F activating point mutation in Jak2 is associated with a proportion of myeloproliferative disorders. In normal hematopoietic cells, Jak2 signals only when associated with a growth factor receptor, such as the erythropoietin receptor (EpoR). We sought to identify the molecular requirements for activation of Jak2V617F by introducing a point mutation in the FERM domain (Y114A), required for receptor binding. Whereas BaF3.EpoR cells are readily transformed by Jak2V617F to Epo independence, we found that the addition of the FERM domain mutation blocked transformation and the induction of reactive oxygen species. Further, while cells expressing Jak2V617F had constitutive activation of STAT5, cells expressing Jak2V617F/Y114A did not, suggesting that signaling is defective at a very proximal level. In addition, expression of the Myc and Pim proto-oncogenes by Jak2V617F was found to be FERM domain dependent. An inducible constitutively active STAT5 mutant expressed in BaF3 cells was sufficient to induce Myc and Pim. Finally, the FERM domain in Jak2V617F was also required for abnormal hematopoiesis in transduced primary murine fetal liver cells. Overall, our results suggest that constitutive activation of Jak2 requires an intact FERM domain for a transforming phenotype, and is necessary for activation of the major target of Jak2, STAT5.

Methamphetamine exposures in young children.

OBJECTIVES: Methamphetamine abuse is reaching epidemic proportions. As this occurs, the likelihood of accidental poisoning in children increases. We sought to evaluate the presentation, treatment, and outcome of pediatric methamphetamine exposures reported to the California Poison Control System. METHODS: This is a retrospective review of California Poison Control System records for methamphetamine exposure from 2000 through 2004. All charts of patients identified as younger than 6 years were reviewed and abstracted. RESULTS: The charts of 47 children younger than 6 years were identified and reviewed. Three were coded as minor effects, 3 as major effects, and 16 as moderate effects. The remainder of the charts were not evaluated because of no effect (n = 6), unrelated or confirmed nonexposure (n = 3), or unable to follow (n = 16). The most common presenting symptom was agitation (82%), whereas seizures were documented in only 2 cases (9%). Tachycardia was common (mean heart rate, 171 beats/min; confidence interval [CI], 154-187), whereas blood pressure (BP) (mean systolic BP, 120 mm Hg; CI, 104-136; and mean diastolic BP, 70 mm Hg; CI, 51-88) and rectal temperature (mean, 37.4 degrees C; CI, 36.9-37.9) were slightly elevated compared with normal values. Creatinine was documented in 6 cases and noted as normal in all (0.3IU/L; CI, 0.2-0.4), whereas creatine kinase was documented in 3 charts and elevated in all (mean 1984 IU/L; range, 212-4942 IU/L). Most cases (55%) received benzodiazepines as treatment, although only 2 received activated charcoal. Symptoms persisted for an average of 22 hours (CI, 16.3-27.2). No deaths were reported. CONCLUSIONS: In this series of children, methamphetamine exposure was strongly associated with agitation that was successfully treated with benzodiazepines. Tachycardia was common, although hypertension and hyperthermia were not. Laboratory studies were not routinely recorded. The clinical significance of elevated creatine kinase concentrations recorded in 3 children is unclear.

Activated Jak2 with the V617F point mutation promotes G1/S phase transition.

Hematopoietic stem cells in myeloproliferative diseases mostly retain the potential to differentiate but are characterized by hyper-responsiveness to growth factors, as well as partial factor-independent growth. The V617F activating point mutation in Jak2 has recently been associated with myeloproliferative disorders. Using various cell line models, mechanisms that contribute to Jak2V617-mediated signaling were investigated. Treatment of the Jak2V617F mutant-expressing erythroid leukemia cell line HEL with a small molecule Jak2 inhibitor was associated with a dose-dependent G(1) cell cycle arrest. This inhibition correlated with decreased expression of cyclin D2 and increased expression of the cell cycle inhibitor p27(Kip). Inhibition of Jak2V617F with a Jak2-targeted small interfering RNA approach resulted in a similar phenotype. Mechanisms leading to altered p27(Kip) and cyclin D2 likely involve inhibition of STAT5, a major target of Jak2 in hematopoietic cells, because a constitutively active form of STAT5 reduced p27(Kip) and increased cyclin D2 expression. Jak2V617F and constitutively active STAT5 also induced high levels of reactive oxygen species, which are sufficient to promote G(1)/S phase transition. In contrast, treatment of HEL cells with the antioxidant N-acetylcysteine decreased cell growth or expression of cyclin D2 and increased expression of p27(Kip). Similar results were obtained in BaF3 cells transfected with Jak2V617F, but these cells required coexpression of the erythropoietin receptor for optimal signaling. These results suggest that regulation of cyclin D2 and p27(Kip) in combination with redox-dependent processes promotes G(1)/S phase transition downstream of Jak2V617F/STAT5 and therefore hint at potential novel targets for drug development that may aid traditional therapy.