Quality assurance of rifampicin-containing fixed-drug combinations in South Africa: dosing implications.

SETTING: Rifampicin (RMP) drives treatment response in drug-susceptible tuberculosis. Low RMP concentrations increase the risk of poor outcomes, and drug quality needs to be excluded as a contributor to low RMP exposure. OBJECTIVES AND DESIGN: We performed an open-label, three-way cross-over study of three licensed RMP-containing formulations widely used in South Africa to evaluate the bioavailability of RMP in a two-drug fixed-dose combination tablet (2FDC) and a four-drug FDC (4FDC) against a single-drug reference. RMP dosed at 600 mg was administered 2 weeks apart in random sequence. Plasma RMP concentrations were measured pre-dose and 1, 2, 3, 4, 6, 8 and 12 h post-dose. The area under the concentration-time curve (AUC0-12) of the FDCs was compared to the single drug reference. Simulations were used to predict the impact of our findings. RESULTS: Twenty healthy volunteers (median age 22.8 years, body mass index 24.2 kg/m2) completed the study. The AUC0-12 of the 4FDC/reference (geometric mean ratio [GMR] 78%, 90%CI 69-89) indicated an average 20% reduction in RMP bioavailability in the 4FDC. The 2FDC/reference (GMR 104%, 90%CI 97-111) was bioequivalent. Simulations suggested dose adjustments to compensate for the poor bioavailability of RMP with the 4FDC, and revised weight-band doses to prevent systematic underdosing of low-weight patients. CONCLUSION: Post-marketing surveillance of in vivo bioavailability of RMP and improved weight band-based dosing are recommended.

Bioavailability of two licensed paediatric rifampicin suspensions: implications for quality control programmes.

SETTING: To assess the revised World Health Organization-recommended dose of 10-20 mg/kg rifampicin (RMP), we studied the steady state pharmacokinetics of RMP in South African children who received standard treatment for drug-susceptible tuberculosis (TB). OBJECTIVE: To determine the formulation effect on the pharmacokinetics of RMP. DESIGN: RMP plasma concentrations were characterised in 146 children (median age 1.4 years, range 0.2-10.2). The morning dose on the day of the pharmacokinetic evaluation was administered as one of two RMP single-drug oral suspensions. RESULTS: While one formulation achieved 2 h concentrations in the range of those observed in adults (median 6.54 mg/l, interquartile range [IQR] 4.47-8.84), the other attained a median bioavailability of only 25% of this, with a median 2 h concentration of 1.59 mg/l (IQR 0.89-2.38). CONCLUSION: RMP is a key drug for the treatment of TB. It is critical that the quality of RMP suspensions used to treat childhood TB is ensured.

A multifaceted hospital-wide intervention increases hand hygiene compliance.

BACKGROUND: Hand hygiene is an important and basic practice that should be used by all healthcare staff to protect both themselves and their patients against infection. Unfortunately hand hygiene compliance remains poor. OBJECTIVE: To show an improvement in hand hygiene compliance using a multifaceted approach. METHODS: This was a quasiexperimental pre-post intervention study design with a number of standardised interventions to promote hand hygiene. The World Health Organization hand hygiene multimodal (five-step) intervention approach was used. The study ran from June 2015 to August 2015 in 11 selected wards of a 975-bed tertiary and quaternary care public hospital (Groote Schuur Hospital, Cape Town, South Africa). The outcome was to assess improvement in hand hygiene compliance monthly over the 3 months, compared with non-intervention wards and compared with the wards' own performance measured in 2014. The study included both descriptive and analytical components. RESULTS: Post intervention, hand hygiene compliance showed a statistically significant improvement for before patient contact from 34% in 2014 to 76% in 2015 (p<0.05) and for after patient contact from 47% in 2014 to 82% in 2015 (p<0.05). CONCLUSION: The intervention improved hand hygiene compliance and can easily be replicated in other wards, resulting in sustaining a culture of hand hygiene improvement and behavioural change throughout the hospital.

Association between diabetes and esophageal cancer, independent of obesity, in the United States Veterans Affairs population.

In the past 30 years, the incidence of esophageal adenocarcinoma (EAC) has increased more rapidly than any other cancer in the United States. The prevalence of obesity and diabetes mellitus has drastically increased as well. We explored the potential association between obesity, diabetes mellitus, and EAC. By means of retrospective interrogation of an administrative database from fiscal year 2005-2009, we identified two cohorts. The cancer cohort was defined as patients with adenocarcinoma of the distal esophagus or gastric cardia. The comparison cohort contained patients with gastroesophageal reflux disorder (GERD; diagnosis coupled with a procedure code for fundoplication). Patient data, including demographic measures, diagnoses of obesity, diabetes mellitus, dyslipidemia, alcohol abuse, and nicotine dependence were examined. A logistic regression model identified risk factors for development of EAC. The sample included 2,836 patients identified as having either EAC (1,704) or fundoplication with GERD (1,132). Although slightly higher percentages of the benign cohort were obese, the cancer cohort had more diabetics (30.8% vs. 14.8%; chi-square = 94.5; P < 0.0001). In a logistic regression analysis adjusting for comorbidity and lifestyle factors, diagnosis of diabetes mellitus was significantly associated with esophageal cancer as opposed to GERD without cancer (OR = 2.2; 95% confidence interval [CI] 1.7-2.8). Nicotine dependence was also identified as a risk factor (OR = 1.7; 95% CI 1.4-2.0). We identified a potential association between diabetes mellitus and adenocarcinoma of the esophagus or gastric cardia. This association appears to be independent of obesity. Additionally, nicotine dependence was identified as a risk factor for EAC.

RECOMBINANT BCL-XL ATTENUATES VASCULAR HYPERPERMEABILITY IN A RAT MODEL OF HEMORRHAGIC SHOCK.

Following hemorrhagic shock (HS), vascular hyperpermeability i.e. the leakage of fluid, nutrients and proteins into the extravascular space occurs primarily due to the disruption of the endothelial cell-cell adherens junctional complex. Studies from our laboratory demonstrate that activation of the mitochondria mediated 'intrinsic' apoptotic signaling cascade has a significant role in modulating HS-induced hyperpermeability. Here we report the novel use of recombinant Bcl-xL, an anti-apoptotic protein, to control HS-induced vascular hyperpermeability. Our results corroborate involvement of vascular hyperpermeability and apoptotic signaling. Hemorrhagic shock (HS) (mean arterial pressure [MAP] was reduced to 40 mmHg for 60 minutes followed by resuscitation to 90 mmHg for 60 minutes) in rats resulted in vascular hyperpermeability as determined by intra-vital microscopy. Treatment of Bcl-xL (2.5ug/ml of rat blood in non-lipid cationic polymer, i.v.) before, during and even after HS attenuated or reversed HS-induced vascular hyperpermeability significantly (p<0.05). Conversely, treatment using Bcl-xL inhibitors, 2-methoxy antimycin (2-MeOAA) and ABT 737, significantly increased vascular hyperpermeability compared to sham (p<0.05). Bcl-xL treatment also decreased the amount of fluid volume required to maintain a MAP of 90 mmHg during resuscitation (p<0.05). HS resulted in increased mitochondrial ROS formation, reduction of ΔΨm, mitochondrial release of cytochrome c and significant activation of caspase-3 (p<0.05). All of these effects were significantly inhibited by Bcl-xL pre-treatment (p<0.05). Our results show that recombinant Bcl-xL is effective against HS-induced vascular hyperpermeability that appears to be mediated through preservation of ΔΨm and subsequent prevention of caspase-3 activation.

Can laparoscopic cholecystectomy be performed with a positive margin at medicaid reimbursement rates?

BACKGROUND: The Affordable Care Act provides health care coverage to an increasing segment of the population at Medicaid reimbursement rates. Health care systems currently offset lower Medicaid reimbursement through higher payers. The ability to "cost shift" will be diminished as the Medicaid population increases. STUDY DESIGN: A financial cost and revenue analysis of outpatient laparoscopic cholecystectomy at our institution was performed. Cost was defined as actual expense to the health care institution. Fixed and variable costs were identified to calculate a break-even point. Time spent from check in to dismissal was based on historic averages. When actual costs could not be pinpointed, estimates from industry experts were used. Reimbursement included surgeon and anesthesia professional fees and facility fees. RESULTS: A total of 501 laparoscopic cholecystectomies were performed at the main operating room facility in 2012. Annual fixed costs were $252,637. Variable costs were $1,860/case. Personnel and single-use equipment made the largest contribution to variable costs. Reimbursement for professional and facility fees totaled $2,444/case. The break-even point occurred at 454 cases. Based on historic volume, the break-even point for the calendar year would occur on November 27. CONCLUSIONS: Our analysis demonstrates that laparoscopic cholecystectomy can be performed with a positive margin at Medicaid reimbursement rates with sufficient volume. The minimal margin, however, could substantially limit the ability of lower-volume hospitals to provide these services and negatively impact access to care in this patient population.

Thymic neuroendocrine carcinoma producing ectopic adrenocorticotropic hormone and Cushing's syndrome.

Neuroendocrine carcinoma of the thymus, previously termed thymic carcinoid, is a rare clinical entity. Rarer still are such cases presenting with endocrinopathies. We report a case of thymic neuroendocrine carcinoma presenting with ectopic adrenocorticotroic hormone production and resultant Cushing's syndrome.

Implementation of a surgical safety checklist: impact on surgical team perspectives.

BACKGROUND: The World Health Organization (WHO) surgical safety checklist has been shown to decrease mortality and complications and has been adopted worldwide. However, system flaws and human errors persist. Identifying provider perspectives of patient safety initiatives may identify strategies for improvement. The purpose of this study was to determine provider perspectives of surgical safety checklist implementation in an effort to improve initiatives that enhance surgical patients' safety. METHODS: In September 2010, a WHO-adapted surgical safety checklist was implemented at our institution. Surgical teams were invited to complete a checklist-focused questionnaire 1 month before and 1 year after implementation. Baseline and follow-up results were compared. RESULTS: A total of 437 surgical care providers responded to the survey: 45% of providers responded at baseline and 64% of providers responded at follow-up. Of the total respondents, 153 (35%) were nurses, 104 (24%) were anesthesia providers, and 180 (41%) were surgeons. Overall, we found an improvement in the awareness of patient safety and quality of care, with significant improvements in the perception of the value of and participation in the time-out process, in surgical team communication, and in the establishment and clarity of patient care needs. Some discordance was noted between surgeons and other surgical team members, indicating that barriers in communication still exist. Overall, approximately 65% of respondents perceived that the checklist improved patient safety and patient care; however, we found a strong negative perception of operating room efficiency. CONCLUSION: Implementation of a surgical safety checklist improves perceptions of surgical safety. Barriers to implementation exist, but staff feedback may be used to enhance the sustainability and success of patient safety initiatives.

Surgical Safety Checklist compliance: a job done poorly!

BACKGROUND: The Surgical Safety Checklist (SSC) has been introduced as an effective tool for reducing perioperative mortality and complications. Although reported completion rates are high, objective compliance is not well defined. The purpose of this retrospective analysis is to determine SSC compliance as measured by accuracy and completion, and factors that can affect compliance. STUDY DESIGN: In September 2010, our institution implemented an adaptation of the World Health Organization's SSC in an effort to improve patient safety and outcomes. A tool was developed for objective evaluation of overall compliance (maximum score 40) that was an aggregate score of completion and accuracy (20 each). Random samples of SSCs were analyzed at specific, predefined, time points throughout the first year after implementation. Procedure start time, operative time, and case complexity were assessed to determine association with compliance. RESULTS: A total of 671 SSCs were analyzed. The participation rate improved from 33% (95 of 285) at week 1 to 94% (249 of 265) at 1 year (p < 0.0001, chi-square test). Mean overall compliance score was 27.7 (± 5.4 SD) of 40 possible points (69.3% ± 13.5% of total possible score; n = 671) and did not change over time. Although completion scores were high (16.9 ± 2.7 out of 20 [84.5% ± 13.6%]), accuracy was poor (10.8 ± 3.4 out of 20 [54.1% ± 16.9%]). Overall compliance score was significantly associated with case start-time (p < 0.05), and operative time and case complexity showed no association. CONCLUSIONS: Our data indicate that although implementation of an SSC results in a high level of overall participation and completion, accuracy remained poor. Identification of barriers to effective use is needed, as improper checklist use can adversely affect patient safety.

Surgical resection of giant fibrous dysplasia for near respiratory collapse.

Fibrous dysplasia may involve the ribs or thoracic spine and cause progressive asphyxiation. We present a 41-year-old man with polyostotic fibrous dysplasia who was admitted to the hospital with progressive shortness of breath requiring initiation of supplemental oxygen. Pulmonary function test results revealed severely limited function with forced expiratory volume in 1 second (FEV1) of 14% predicted and diffusion capacity of 17%. As a lifesaving effort, the patient was offered resection, decortication, and chest wall reconstruction, after which the lung reexpanded. At 6 months, his FEV1 was 49% and his diffusion capacity was 56%. He no longer required supplemental oxygen and now exercises daily.

Surgical care improvement project and surgical site infections: can integration in the surgical safety checklist improve quality performance and clinical outcomes?

INTRODUCTION: The World Health Organization Surgical Safety Checklist (SSC) has been shown to decrease surgical site infections (SSI). The Surgical Care Improvement Project (SCIP) SSI reduction bundle (SCIP Inf) contains elements to improve SSI rates. We wanted to determine if integration of SCIP measures within our SSC would improve SCIP performance and patient outcomes for SSI. METHODS: An integrated SSC that included perioperative SCIP Inf measures (antibiotic selection, antibiotic timing, and temperature management) was implemented. We compared SCIP Inf compliance and patient outcomes for 1-y before and 1-y after SSC implementation. Outcomes included number of patients with initial post-anesthesia care unit temperature <98.6°F and SSI rates according to our National Surgical Quality Improvement Program data. RESULTS: Implementation of a SCIP integrated SSC resulted in a significant improvement in antibiotic infusion timing (92.7% [670/723] versus 95.4% [557/584]; P < 0.05), antibiotic selection (96.2% [707/735] versus 98.7% [584/592]; P < 0.01), and temperature management (93.8% [723/771] versus 97.7% [693/709]; P < 0.001). Furthermore, we found a significant reduction in number of patients with initial post-anesthesia care unit temperature <98.6°F from 9.7% (982/10,126) to 6.9% (671/9676) (P < 0.001). Institutional SSI rates decreased from 3.13% (104/3319) to 2.96% (107/3616), but was not significant (P = 0.72). SSI rates according to specialty service were similar for all groups except colorectal surgery (24.1% [19/79] versus 11.5% [12/104]; P < 0.05). CONCLUSION: Implementation of an integrated SSC can improve compliance of SSI reduction strategies such as SCIP Inf performance and maintenance of normothermia. This did not, however, correlate with an improvement in overall SSI at our institution. Further investigation is required to determine other factors that may influence SSI at an institutional level.

Are commercial negative pressure systems worth the cost in open abdomen management?

BACKGROUND: A commercial negative pressure product is compared with the Barker technique (sterile x-ray cassette cover, lap pads, adhesive drape with negative pressure) for temporary abdominal closure in open abdomen management. STUDY DESIGN: We performed a retrospective review of 37 open abdomen patients who had temporary abdominal closure with a commercial negative pressure device (ABThera, KCI) from 2010 to 2011. These patients were compared with the most recent 37 patients having open abdomen management using the Barker technique from 2009 to 2010. Patient demographics, body mass index (BMI), preoperative albumin, indication for open abdomen management, number of operations, use of sequential closure, and success with closure were analyzed. Patients were compared using chi square, t-test, and logistic regression analysis with significance of p < 0.05. RESULTS: Mean age and BMI were significantly higher in the ABThera patients. No statistically significant differences were seen in male:female ratio, indication for open abdomen management, preoperative albumin, number of operations, and use of sequential closure. In 33 patients (89%) ultimate midline fascial closure was achieved with the ABThera vs in 22 patients (59%) using the Barker technique (p < 0.05). Logistic regression analysis was performed on the 3 significant variables identified on bivariate analysis. Only the type of temporary abdominal closure proved significant, with an odds ratio of 7.97 favoring ABThera (95% CI 1.98 to 32.00). CONCLUSIONS: A commercially available negative pressure device for temporary abdominal closure had significantly greater success with ultimate closure after open abdomen management compared with the Barker technique. The added cost of the device is offset by improved patient results and savings from successful closure.

Inhibition of Fas-Fas ligand interaction attenuates microvascular hyperpermeability following hemorrhagic shock.

Hemorrhagic shock (HS)-induced microvascular hyperpermeability poses a serious challenge in the management of trauma patients. Microvascular hyperpermeability occurs mainly because of the disruption of endothelial cell adherens junctions, where the "intrinsic" apoptotic signaling plays a regulatory role. The purpose of this study was to understand the role of the "extrinsic" apoptotic signaling molecules, particularly Fas-Fas ligand interaction in microvascular endothelial barrier integrity. Rat lung microvascular endothelial cells (RLMECs) were exposed to HS serum in the presence or absence of the Fas ligand inhibitor, FasFc. The effect of HS serum on Fas receptor and Fas ligand expression on RLMECs was determined by flow cytometry. Endothelial cell permeability was determined by monolayer permeability assay and the barrier integrity by ß-catenin immunofluorescence. Mitochondrial reactive oxygen species formation was determined using dihydrorhodamine 123 probe by fluorescent microscopy. Mitochondrial transmembrane potential was studied by fluorescent microscopy as well as flow cytometry. Caspase 3 enzyme activity was assayed fluorometrically. Rat lung microvascular endothelial cells exposed to HS serum showed increase in Fas receptor and Fas ligand expression levels. FasFc treatment showed protection against HS serum-induced disruption of the adherens junctions and monolayer hyperpermeability (P < 0.05) in the endothelial cells. Pretreatment with FasFc also decreased HS serum-induced increase in mitochondrial reactive oxygen species formation, restored HS serum-induced drop in mitochondrial transmembrane potential, and reduced HS serum-induced caspase 3 activity in RLMECs. These findings open new avenues for drug development to manage HS-induced microvascular hyperpermeability by targeting the Fas-Fas ligand-mediated pathway.

The downregulation of Mcl-1 via USP9X inhibition sensitizes solid tumors to Bcl-xl inhibition.

BACKGROUND: It has been shown in many solid tumors that the overexpression of the pro-survival Bcl-2 family members Bcl-xL and Mcl-1 confers resistance to a variety of chemotherapeutic agents. Mcl-1 is a critical survival protein in a variety of cell lineages and is critically regulated via ubiquitination. METHODS: The Mcl-1, Bcl-xL and USP9X expression patterns in human lung and colon adenocarcinomas were evaluated via immunohistochemistry. Interaction between USP9X and Mcl-1 was demonstrated by immunoprecipitation-western blotting. The protein expression profiles of Mcl-1, Bcl-xL and USP9X in multiple cancer cell lines were determined by western blotting. Annexin-V staining and cleaved PARP western blotting were used to assay for apoptosis. The cellular toxicities after various treatments were measured via the XTT assay. RESULTS: In our current analysis of colon and lung cancer samples, we demonstrate that Mcl-1 and Bcl-xL are overexpressed and also co-exist in many tumors and that the expression levels of both genes correlate with the clinical staging. The downregulation of Mcl-1 or Bcl-xL via RNAi was found to increase the sensitivity of the tumor cells to chemotherapy. Furthermore, our analyses revealed that USP9X expression correlates with that of Mcl-1 in human cancer tissue samples. We additionally found that the USP9X inhibitor WP1130 promotes Mcl-1 degradation and increases tumor cell sensitivity to chemotherapies. Moreover, the combination of WP1130 and ABT-737, a well-documented Bcl-xL inhibitor, demonstrated a chemotherapeutic synergy and promoted apoptosis in different tumor cells. CONCLUSION: Mcl-1, Bcl-xL and USP9X overexpression are tumor survival mechanisms protective against chemotherapy. USP9X inhibition increases tumor cell sensitivity to various chemotherapeutic agents including Bcl-2/Bcl-xL inhibitors.

Molecular pathogenesis of malignant mesothelioma.

Malignant mesothelioma is a rare, highly aggressive cancer arising from mesothelial cells that line the pleural cavities. Approximately 80% of mesothelioma cases can be directly attributed to asbestos exposure. Additional suspected causes or co-carcinogens include other mineral fibres, simian virus 40 (SV40) and radiation. A mesothelioma epidemic in Turkey has demonstrated a probable genetic predisposition to mineral fibre carcinogenesis and studies of human tissues and animal models of mesothelioma have demonstrated genetic and epigenetic events that contribute to the multistep process of mineral fibre carcinogenesis. Several growth factors and their receptors have a significant role in the oncogenesis, progression and resistance to therapy of mesothelioma. Epidermal growth factor (EGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF) have been shown as targets for therapy based on promising preclinical data. However, clinical trials of tyrosine kinase inhibitors in mesothelioma have been disappointing. Bcl-XL is an important antiapoptotic member of the Bcl-2 family and is overexpressed in several solid tumours, including mesothelioma. Reduction of Bcl-XL expression in mesothelioma induces apoptosis and engenders sensitisation to cytotoxic chemotherapeutic agents. Pharmacological inhibitors of antiapoptotic Bcl-2 family members continue to undergo refinement and have shown promise in mesothelioma.

Relaxation of the rigid backbone of an oligoamide-foldamer-based α-helix mimetic: identification of potent Bcl-xL inhibitors.

By conducting a structure-activity relationship study of the backbone of a series of oligoamide-foldamer-based α-helix mimetics of the Bak BH3 helix, we have identified especially potent inhibitors of Bcl-x(L). The most potent compound has a K(i) value of 94 nM in vitro, and single-digit micromolar IC(50) values against the proliferation of several Bcl-x(L)-overexpressing cancer cell lines.

ß-Catenin dynamics in the regulation of microvascular endothelial cell hyperpermeability.

ß-Catenin, a key regulator of barrier integrity, is an important component of the adherens junctional complex. Although the roles of ß-catenin in maintaining the adherens junctions and Wnt signaling are known, the dynamics of ß-catenin following insult and its potential role in vascular recovery/repair remain unclear. Our objective was to define ß-catenin's dynamics following disruption of the adherens junctional complex and subsequent recovery. Rat lung microvascular endothelial cells were treated with active caspase 3 enzyme, by protein transference method, as an inducer of junctional damage and permeability. The disruption and subsequent recovery of ß-catenin to the adherens junctions were studied via immunofluorescence. Rat lung microvascular endothelial cell monolayers were used to measure hyperpermeability. To understand the role of ß-catenin on nuclear translocation/transcriptional regulation in relationship to the recovery of the adherens junctions, Tcf-mediated transcriptional activity was determined. Active caspase 3 induced a loss of ß-catenin at the adherens junctions at 1 and 2 h followed by its recovery at 3 h. Transference of Bak peptide, an inducer of endogenous caspase 3 activation, induced hyperpermeability at 1 h followed by a significant decrease at 2 h. Inhibition of GSK-3ß and the transfection of ß-catenin vector increased Tcf-mediated transcription significantly (P < 0.05). The dissociated adherens junctional protein ß-catenin translocates into the cytoplasm, resulting in microvascular hyperpermeability followed by a time-dependent recovery and relocation to the cell membrane. Our data suggest a recycling pathway for ß-catenin to the cell junction.

Benign emptying of the postpneumonectomy space.

BACKGROUND: A fall in the postpneumonectomy fluid level is considered a sign of bronchopleural fistula (BPF) requiring surgical intervention. We have discovered however that in rare asymptomatic patients, this event may not require aggressive surgical treatment. METHODS: After seeing a case of benign emptying of the postpneumonectomy space (BEPS), we surveyed 28 surgeons to determine its incidence and characteristics. RESULTS: Forty-four cases of BEPS were reported by 23 survey respondents. Among 7 fully documented cases from 4 institutions, we defined the following criteria: the patient must be asymptomatic (no fever, white cell count elevation, or fluid expectoration), negative culture results if fluid sampled (patient not receiving antibiotics), no BPF at bronchoscopy or ventilation scintigraphy scan (or both), and recovery without drainage, or retrospective assessment that the intervention was unnecessary. BEPS occurred between 5 days and 152 days after pneumonectomy (6 cases right pneumonectomy and 1 case left pneumonectomy). Four patients underwent no treatment, 1 patient underwent thoracoscopic exploration (sterile) and closure after antibiotic irrigation, 1 patient underwent thoracoscopic exploration alone, and 1 patient underwent open window thoracostomy (sterile) with eventual closure. In all 7 patients (except the patient who underwent the open window procedure) the space refilled within 8 weeks; no patient experienced a subsequent empyema/BPF. Four patients who met the initial criteria for BEPS went on to experience empyema. The incidence of BEPS appears related to pneumonectomy volume, particularly extrapleural pneumonectomy. Using surgeon volume assumptions, the incidence of BEPS is 0.65%. CONCLUSIONS: To our knowledge, BEPS is a previously unreported occurrence. We hypothesize that it results from postoperative intrapleural pressure shifts, with or without a microscopic BPF, that drive fluid out of the pleural space while failing to cause contamination. Awareness of BEPS' existence may allow surgeons to safely avoid open drainage procedures occasionally in patients who experience an asymptomatic fall in fluid level.

Chondrosarcoma of the thorax.

Although a rare entity, chondrosarcoma is the most common malignant tumor of the chest wall. Most patients present with an enlarging, painful anterior chest wall mass arising from the costochondrosternal junction. CT scan with intravenous contrast is the gold standard radiographic study for diagnosis and operative planning. Contrary to previous dictum, resection may be performed in an appropriate surgical candidate based on imaging characteristics or image-guided percutaneous biopsy results; incisional biopsy is rarely required. The keys to successful treatment are early recognition and radical excision with adequate margins, as chondrosarcoma is relatively resistant to radiotherapy and conventional cytotoxic chemotherapy. Overall survival is excellent in most surgical series from experienced centers. Complete excision with widely negative microscopic margins at the initial operation is of the utmost importance, as local recurrence portends systemic metastasis and eventual tumor-related mortality. This paper summarizes data from relevant surgical series and thereupon draws conclusions regarding preoperative, intraoperative, and postoperative management of thoracic chondrosarcoma.

Role of ß-catenin in regulating microvascular endothelial cell hyperpermeability.

BACKGROUND: Paracellular microvascular hyperpermeability occurs mainly because of the disruption of the endothelial adherens junction complex. Vascular endothelial-cadherin that consists of an extracellular and intracellular domain to confer cell-cell contact is linked to the actin cytoskeletal assembly through ß-catenin. Our objective was to determine the functional role of ß-catenin during paracellular hyperpermeability and to evaluate whether exogenous ß-catenin would protect against vascular leak. METHODS: ß-Catenin siRNA (2.5 µg/mL) was administered to Sprague-Dawley rats through tail vein. FITC-albumin extravasation of the mesenteric postcapillary venules was evaluated after 48 hours using intravital microscopy. Parallel studies using rat lung microvascular endothelial cell monolayers were transfected with ß-catenin siRNA, and hyperpermeability was determined using monolayers after 48 hours. The effectiveness of ß-catenin siRNA was tested using immunofluorescence and Western blot. To study the protective effect of ß-catenin, rat lung microvascular endothelial cell monolayers were transfected with a ß-catenin gene expression construct for 48 hours or a recombinant ß-catenin protein (1 µg/mL) for 2 hours, followed by transfection with proapoptotic BAK peptide (5 µg/mL), a known inducer hyperpermeability. RESULTS: ß-Catenin siRNA induced a significant increase in vascular hyperpermeability in vivo (p<0.05) and monolayer permeability (in vitro; p<0.05). ß-Catenin siRNA significantly altered the adherens junction complex and decreased ß-catenin protein levels. ß-Catenin gene expression construct or recombinant ß-catenin protein attenuated BAK-induced monolayer hyperpermeability significantly (p<0.05). CONCLUSION: Posttranscriptional gene silencing of ß-catenin leads to vascular hyperpermeability in vivo and monolayer hyperpermeability in vitro. The enhancement of ß-catenin gene expression at the adherens junction or exogenous introduction of ß-catenin protein shows protection against vascular hyperpermeability.