Antimicrobial Susceptibility Testing of Mycobacterium Tuberculosis Complex for First and Second Line Drugs by Broth Dilution in a Microtiter Plate Format

The rapid detection of antimicrobial resistance is important in the effort to control the increase in resistant Mycobacterium tuberculosis (Mtb). Antimicrobial susceptibility testing (AST) of Mtb has traditionally been performed by the agar method of proportion or by macrobroth testing on an instrument such as the BACTEC (Becton Dickinson, Sparks, MD), VersaTREK (TREK Diagnostics, Cleveland, OH) or BacT/ALERT (bioMérieux, Hazelwood, MO). The agar proportion method, while considered the “gold” standard of AST, is labor intensive and requires calculation of resistance by performing colony counts on drug-containing agar as compared to drug-free agar. If there is ≥1% growth on the drug-containing medium as compared to drug-free medium, the organism is considered resistant to that drug. The macrobroth methods require instrumentation and test break point ("critical") drug concentrations for the first line drugs (isoniazid, ethambutol, rifampin, and pyrazinamide). The method described here is commercially available in a 96 well microtiter plate format [MYCOTB (TREK Diagnostics)] and contains increasing concentrations of 12 antimicrobials used for treatment of tuberculosis including both first (isoniazid, rifampin, ethambutol) and second line drugs (amikacin, cycloserine, ethionamide, kanamycin, moxifloxacin, ofloxacin, para-aminosalicylic acid, rifabutin, and streptomycin). Pyrazinamide, a first line drug, is not included in the microtiter plate due to its need for acidic test conditions. Advantages of the microtiter system include both ease of set up and faster turn around time (14 days) compared with traditional agar proportion (21 days). In addition, the plate can be set up from inoculum prepared using either broth or solid medium. Since the microtiter plate format is new and since Mtb presents unique safety challenges in the laboratory, this protocol will describe how to safely setup, incubate and read the microtiter plate

Differential involvement of the microtubule cytoskeleton in insulin receptor substrate 1 (IRS-1) and IRS-2 signaling to AKT determines the response to microtubule disruption in breast carcinoma cells

The insulin receptor substrate (IRS) proteins serve as essential signaling intermediates for the activation of PI3K by both the insulin-like growth factor 1 receptor (IGF-1R) and its close family member, the insulin receptor (IR). Although IRS-1 and IRS-2 share significant homology, they regulate distinct cellular responses downstream of these receptors and play divergent roles in breast cancer. To investigate the mechanism by which signaling through IRS-1 and IRS-2 results in differential outcomes, we assessed the involvement of the microtubule cytoskeleton in IRS-dependent signaling. Treatment with drugs that either stabilize or disrupt microtubules reveal that an intact microtubule cytoskeleton contributes to IRS-2- but not IRS-1-mediated activation of AKT by IGF-1. Proximal IGF-1R signaling events, including IRS tyrosine phosphorylation and recruitment of PI3K, are not inhibited by microtubule disruption, indicating that IRS-2 requires the microtubule cytoskeleton at the level of downstream effector activation. IRS-2 colocalization with tubulin is enhanced upon Taxol-mediated microtubule stabilization, which, together with the signaling data, suggests that the microtubule cytoskeleton may facilitate access of IRS-2 to downstream effectors such as AKT. Of clinical relevance is that our data reveal that expression of IRS-2 sensitizes breast carcinoma cells to apoptosis in response to treatment with microtubule-disrupting drugs, identifying IRS-2 as a potential biomarker for the response of breast cancer patients to Vinca alkaloid drug treatment

Self-Definition of Women Experiencing a Nontraditional Graduate Fellowship Program

Women continue to be underrepresented in the fields of science, technology, engineering, and mathematics (STEM). One factor contributing to this underrepresentation is the graduate school experience. Graduate programs in STEM fields are constructed around assumptions that ignore the reality of women’s lives; however, emerging opportunities may lead to experiences that are more compatible for women. One such opportunity is the Graduate Teaching Fellows in K–12 Education (GK–12) Program, which was introduced by the National Science Foundation in 1999. Although this nontraditional graduate program was not designed explicitly for women, it provided an unprecedented context in which to research how changing some of the basic assumptions upon which a graduate school operates may impact women in science. This exploratory case study examines the self-definition of 8 women graduate students who participated in a GK–12 program at a major research university. The findings from this case study contribute to higher education’s understanding of the terrain women graduate students in the STEM areas must navigate as they participate in programs that are thought to be more conducive to their modes of self-definition while they continue to seek to be successful in the historically Eurocentric, masculine STEM fields

Does the Robotic Platform Reduce Morbidity Associated With Combined Radical Surgery and Adjuvant Radiation for Early Cervical Cancers?

Open radical hysterectomy followed by adjuvant radiation for cervical cancer has been associated with significant rates of morbidity. Radical hysterectomy is now often performed robotically. We sought to examine if the robotic platform decreased the morbidity associated with radical hysterectomy followed by adjuvant radiation

Testing a Mahalanobis Distance Model of Black Bear Habitat Use in the Ouachita Mountains of Oklahoma

Regional wildlife–habitat models are commonly developed but rarely tested with truly independent data. We tested a published habitat model for black bears (Ursus americanus) with new data collected in a different site in the same ecological region (i.e., Ouachita Mountains of Arkansas and Oklahoma, USA). We used a Mahalanobis distance model developed from relocations of black bears in Arkansas to produce a map layer of Mahalanobis distances on a study area in neighboring Oklahoma. We tested this modeled map layer with relocations of black bears on the Oklahoma area. The distributions of relocations of female black bears were consistent with model predictions. We conclude that this modeling approach can be used to predict regional suitability for a species of interest

Safety and effectiveness of insulin pump therapy in children and adolescents with type 1 diabetes

WSTĘP. Celem pracy była ocena bezpieczeństwa skuteczności stosowania pompy insulinowej u dzieci młodzieży chorych na cukrzycę typu 1. MATERIAŁ I METODY. Do badania włączono 95 dzieci, które rozpoczęły stosowanie pompy insulinowej w Johns Hopkins Hospital w okresie od stycznia 1990 do grudnia 2000 roku. Średni wiek badanych wynosił 12,0 lat (przedział 4&#8211;18 lat); 29% badanych było poniżej 10 roku życia. Dane zebrano z dokumentacji medycznej, począwszy od okresu 6&#8211;12 miesięcy przed zastosowaniem terapii pompą insulinową. Średni czas obserwacji wynosił 28 miesięcy. WYNIKI. Zaobserwowano niewielkie, lecz znamienne statystycznie obniżenie stężenia HbA1c w 3.&#8211;6. miesiącu terapii (7,7% vs. 7,5%, p = 0,03). W czasie dalszej obserwacji stężenie to stopniowo zwiększało się i pozostało podwyższone po roku, jednak na to zjawisko wpływał wiek badanych i czas trwania cukrzycy. Obie wymienione zmienne wiązały się z wyższym stężeniem HbA1c. Po uwzględnieniu wieku i czasu trwania cukrzycy średnie stężenie HbA1c po rozpoczęciu terapii pompą insulinową było znamiennie niższe niż przed jej zastosowaniem (7,7% vs. 8,1%, p < 0,001). Częstość powikłań (kwasica ketonowa, interwencje w izbie przyjęć) była podobna przed i po rozpoczęciu leczenia. Zaobserwowano mniej incydentów hipoglikemii po rozpoczęciu terapii (12 vs. 17, współczynnik częstości = 0,46; 95% CI 0,21&#8211;1,01). WNIOSKI. Badanie to sugeruje, że stosowanie pompy insulinowej jest bezpieczną i skuteczną metodą leczenia u wybranych dzieci chorych na cukrzycę typu 1.INTRODUCTION. To evaluate the safety and effectiveness of insulin pump therapy in children and adolescents with type 1 diabetes. MATERIAL AND METHODS. All 95 patients who began insulin pump therapy at Johns Hopkins Hospital between January 1990 and December 2000 were included in the study. The mean age was 12.0 years (range 4&#8211;18), and 29% of the patients were < 10 years old. Data were obtained by chart review beginning 6&#8211;12 months before pump start. The median duration of follow-up was 28 months. RESULTS. There was a small but significant decrease in HbA1c at 3&#8211;6 months after pump start (7.7% vs. 7.5%; P = 0.03). HbA1c levels then gradually increased and remained elevated after 1 year of followup; however, this association was confounded by age and diabetes duration, both of which were associated with higher HbA1c levels. After adjusting for duration and age, mean HbA1c after pump start was significantly lower than before pump start (7.7% vs. 8.1%; P < 0.001). The number of medical complications (diabetic ketoacidosis, emergency department visits) was similar before and after pump start. There were fewer hypoglycemic events after pump start (12 vs. 17, rate ratio 0.46, 95% CI 0.21&#8211;1.01). CONCLUSIONS. This study suggests that pump therapy is safe and effective in selected children and adolescents with type 1 diabetes

Insulin Receptor Substrate-1 (IRS-1) and IRS-2 expression levels are associated with prognosis in non-small cell lung cancer (NSCLC)

The insulin-like growth factor-1 (IGF-1) signaling pathway has been implicated in non-small cell lung cancer (NSCLC) outcomes and resistance to targeted therapies. However, little is known regarding the molecular mechanisms by which this pathway contributes to the biology of NSCLC. The insulin receptor substrate (IRS) proteins are cytoplasmic adaptor proteins that signal downstream of the IGF-1R and determine the functional outcomes of this signaling pathway. In this study, we assessed the expression patterns of IRS-1 and IRS-2 in NSCLC to identify associations between IRS-1 and IRS-2 expression levels and survival outcomes in the two major histological subtypes of NSCLC, adenocarcinoma (ADC) and squamous cell carcinoma (SCC). High IRS-2 expression was significantly associated with decreased overall survival in adenocarcinoma (ADC) patients, whereas low IRS-1 cytoplasmic expression showed a trend toward association with decreased overall survival in squamous cell carcinoma (SCC) patients. Tumors with low IRS-1 and high IRS-2 expression were found to be associated with poor outcomes in ADC and SCC, indicating a potential role for IRS-2 in the aggressive behavior of NSCLC. Our results suggest distinct contributions of IRS-1 and IRS-2 to the biology of ADC and SCC that impact disease progression

JQ1 suppresses tumor growth via PTEN/PI3K/AKT pathway in endometrial cancer

Overexpression of c-Myc is associated with worse outcomes in endometrial cancer, indicating that c-Myc may be a promising target for endometrial cancer therapy. A novel small molecule, JQ1, has been shown to block BRD4 resulting in inhibition of c-Myc expression and tumor growth. Thus, we investigated whether JQ1 can inhibit endometrial cancer growth in cell culture and xenograft models. In PTEN-positive endometrial cancer cells, JQ1 significantly suppressed cell proliferation via induction of G1 phase arrest and apoptosis in a dose-dependent manner, accompanied by a sharp decline in cyclin D1 and CDK4 protein expression. However, PTEN-negative endometrial cancer cells exhibited intrinsic resistance to JQ1, despite significant c-Myc inhibition. Moreover, we found that PTEN and its downstream PI3K/AKT signaling targets were modulated by JQ1, as evidenced by microarray analysis. Silencing of PTEN in PTEN-positive endometrial cancer cells resulted in resistance to JQ1, while upregulation of PTEN in PTEN-negative endometrial cancer cells increased sensitivity to JQ1. In xenografts models of PTEN-positive and PTEN-knock-in endometrial cancer, JQ1 significantly upregulated the expression of PTEN, blocked the PI3K/AKT signaling pathway and suppressed tumor growth. These effects were attenuated in PTEN-negative and PTEN-knockdown xenograft models. Thus, JQ1 resistance appears to be highly associated with the status of PTEN expression in endometrial cancer. Our findings suggest that targeting BRD4 using JQ1 might serve as a novel therapeutic strategy in PTEN-positive endometrial cancers

Dual codes of projective planes of order 25

Peer Reviewe

Everolimus exhibits anti-tumorigenic activity in obesity-induced ovarian cancer

Everolimus inhibits mTOR kinase activity and its downstream targets by acting on mTORC1 and has anti-tumorigenic activity in ovarian cancer. Clinical and epidemiologic data find that obesity is associated with worse outcomes in ovarian cancer. In addition, obesity leads to hyperactivation of the mTOR pathway in epithelial tissues, suggesting that mTOR inhibitors may be a logical choice for treatment in obesity-driven cancers. However, it remains unclear if obesity impacts the effect of everolimus on tumor growth in ovarian cancer. The present study was aimed at evaluating the effects of everolimus on cytotoxicity, cell metabolism, apoptosis, cell cycle, cell stress and invasion in human ovarian cancer cells. A genetically engineered mouse model of serous ovarian cancer fed a high fat diet or low fat diet allowed further investigation into the inter-relationship between everolimus and obesity in vivo. Everolimus significantly inhibited cellular proliferation, induced cell cycle G1 arrest and apoptosis, reduced invasion and caused cellular stress via inhibition of mTOR pathways in vitro. Hypoglycemic conditions enhanced the sensitivity of cells to everolimus through the disruption of glycolysis. Moreover, everolimus was found to inhibit ovarian tumor growth in both obese and lean mice. This reduction coincided with a decrease in expression of Ki-67 and phosphorylated-S6, as well as an increase in cleaved caspase 3 and phosphorylated-AKT. Metabolite profiling revealed that everolimus was able to alter tumor metabolism through different metabolic pathways in the obese and lean mice. Our findings support that everolimus may be a promising therapeutic agent for obesity-driven ovarian cancers