The Dynamic Functions Of Bax Are Dependent On Key Structural And Regulatory Features

Bax is an essential mediator of cell fate. Since its discovery in 1985 as a protein that interacts with the anti-apoptotic protein, Bcl-2, key elements related to its function, structure and regulation remains to be determined. To this end, mitochondrial metabolism was examined in non-apoptotic Bax-deficient HCT-116 cells as well as primary hepatocytes from Bax-deficient mice. Although mitochondrial density and mitochondrial DNA content was the same in Bax-containing and Bax -deficient cells, MitoTracker staining patterns differed, suggesting the existence of Bax -dependent functional differences in mitochondrial physiology. Oxygen consumption and cellular ATP levels were reduced in Bax -deficient cells, while glycolysis was increased. These results suggest that cells lacking Bax have a deficiency in the ability to generate ATP through cellular respiration, supported by detection of reduced citrate synthase activity in Bax -deficient cells. Expression of either full length or C-terminal truncated Bax in Bax -deficient cells rescued ATP synthesis and oxygen consumption and reduced glycolytic activity, suggesting that this metabolic function of Bax was not dependent upon its C-terminal helix. Expression of BCL-2 in Bax-containing cells resulted in a subsequent loss of ATP measured, implying that, even under non-apoptotic conditions, an antagonistic interaction exists between the two proteins. Bax is composed of nine alpha-helices. While three of these helices have features of a trans-membrane region, the contribution of each domain to the apoptotic or non-apoptotic functions of Bax remains unknown. To examine this, we focused on the C-terminal alpha-9 helix, an amphipathic domain with putative membrane binding iv properties and discovered that it has an inherent membrane-binding and cytotoxic capacity. A peptide based on the last twenty amino acids (CT20p) of the alpha-9 helix was synthesized and proved a potent inducer of cell death independent of any apoptotic stimuli. The solubility of CT20p allowed it to be encapsulated in polymeric nanoparticles (NPs), and these CT20p-NPs caused the death of colon and breast cancer cells in vitro and induced tumor regression in vivo, using a murine breast cancer tumor model. CT20p caused increased mitochondrial membrane potential followed by cell death via membrane rupture, without the characteristic membrane asymmetry associated with apoptosis. Hence, while CT20p is based on Bax, its innate cytotoxic activity is unlike the parent protein and could be a powerful anti-cancer agent that bypasses drug resistance, can be encapsulated in tumor-targeted nanoparticles and has potential application in combination therapies to activate multiple death pathways in cancer cells. While previous work revealed novel aspects of the biology of Bax that were unrecognized, new structural information is needed to fully elucidate the complexity of Bax’s function. One approach is to use computational modeling to assess the solved structure of Bax and provide insight into the structural components involved in the activity of the protein. Use of molecular dynamics simulators such as GROMACS, as well as other computational tools provides a powerful means by which to test the feasibility of certain modifications in defined parameters. Such work revealed that the removal of the C-terminal alpha-9 helix of Bax, which normally resides within a hydrophobic pocket, significantly destabilized the protein, perhaps explaining how the protein transitions from soluble to membrane-bound form and maintain energy v production via aerobic respiration or, conversely, how the C-terminus helix conveys cytotoxicity. Collectively, this work reveals that Bax is more than an inducer of cell death but has complex activities yet to be determined

HEALTH, TORTS, AND CIVIL PRACTICE Georgia Hospital and Medical Liability Insurance Authority Act: Provide for Legislative Findings with Respect to a Crisis in the Field of Hospital and Medical Liability Insurance; Address This Crisis Through Provision of Insurance and Certain Civil Justice Reforms; Create the Georgia Hospital and Medical Liability Insurance Authority; Provide for the Members of the Authority and Their Selection, Service, and Terms of Office; Provide for the Filling of Vacancies; Provide for the Powers, Duties, Operations, and Financial Affairs of the Authority; Provide for the General Purpose of the Authority; Prescribe Standards Relating to Vicarious Liability of Medical Facilities for Actions of Health Care Providers; Provide for Limited Liability for Certain Medical Facilities and Health Care Providers for Treatment of Certain Emergency Conditions Under Certain Conditions; Provide for Qualifications of Experts; Change Provisions Relating to the Allocation of Liability and Recovery of Damages in Tort Actions; Provide for the Degree of Care Expected of Medical Professionals in an Emergency Room Setting; Provide for the Consideration by the Jury or Other Trier of Fact of Certain Factors Affecting This Care in Determining Whether Defendants Met This Degree or Standard of Care; Require the Approval by the Commissioner of Insurance of All medical Malpractice Rates, Rating Plans, Rating Systems, and underwriting Rules Prior to These Rates, Rating Plans, Rating Systems, and Underwriting Rules Becoming Effective; Change Certain Provisions Relating to Actions Against Certain Codefendants Residing in Different Counties; Change Provisions Relating to the Required Filing of Affidavits in Professional malpractice Actions; Provide for other Related Matters; Repeal Conflicting Laws; and for Other Purposes

The bill would have created an authority with power to provide rural hospitals with the ability to self-ensure. The bill would have allowed emergency facilities to limit liability associated with doctors who are independent contractors. The bill would have also restricted recovery from each defendant based on apportionment of liability rather than the usual joint and several liability schemes. The bill failed after a standoff on an amendment to cap non-economic damages

HEALTH, TORTS, AND CIVIL PRACTICE Georgia Hospital and Medical Liability Insurance Authority Act: Provide for Legislative Findings with Respect to a Crisis in the Field of Hospital and Medical Liability Insurance; Address This Crisis Through Provision of Insurance and Certain Civil Justice Reforms; Create the Georgia Hospital and Medical Liability Insurance Authority; Provide for the Members of the Authority and Their Selection, Service, and Terms of Office; Provide for the Filling of Vacancies; Provide for the Powers, Duties, Operations, and Financial Affairs of the Authority; Provide for the General Purpose of the Authority; Prescribe Standards Relating to Vicarious Liability of Medical Facilities for Actions of Health Care Providers; Provide for Limited Liability for Certain Medical Facilities and Health Care Providers for Treatment of Certain Emergency Conditions Under Certain Conditions; Provide for Qualifications of Experts; Change Provisions Relating to the Allocation of Liability and Recovery of Damages in Tort Actions; Provide for the Degree of Care Expected of Medical Professionals in an Emergency Room Setting; Provide for the Consideration by the Jury or Other Trier of Fact of Certain Factors Affecting This Care in Determining Whether Defendants Met This Degree or Standard of Care; Require the Approval by the Commissioner of Insurance of All medical Malpractice Rates, Rating Plans, Rating Systems, and underwriting Rules Prior to These Rates, Rating Plans, Rating Systems, and Underwriting Rules Becoming Effective; Change Certain Provisions Relating to Actions Against Certain Codefendants Residing in Different Counties; Change Provisions Relating to the Required Filing of Affidavits in Professional malpractice Actions; Provide for other Related Matters; Repeal Conflicting Laws; and for Other Purposes

The bill would have created an authority with power to provide rural hospitals with the ability to self-ensure. The bill would have allowed emergency facilities to limit liability associated with doctors who are independent contractors. The bill would have also restricted recovery from each defendant based on apportionment of liability rather than the usual joint and several liability schemes. The bill failed after a standoff on an amendment to cap non-economic damages

Methods and Compositions Comprising a C-Terminal Bax Peptide (US)

The invention describes the use of the protein, Bax, as a potential therapeutic treatment for cancer

Email for communicating results of diagnostic medical investigations to patients

<p>Background: As medical care becomes more complex and the ability to test for conditions grows, pressure on healthcare providers to convey increasing volumes of test results to patients is driving investigation of alternative technological solutions for their delivery. This review addresses the use of email for communicating results of diagnostic medical investigations to patients.</p> <p>Objectives: To assess the effects of using email for communicating results of diagnostic medical investigations to patients, compared to SMS/ text messaging, telephone communication or usual care, on outcomes, including harms, for health professionals, patients and caregivers, and health services.</p> <p>Search methods: We searched: the Cochrane Consumers and Communication Review Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 1 2010), MEDLINE (OvidSP) (1950 to January 2010), EMBASE (OvidSP) (1980 to January 2010), PsycINFO (OvidSP) (1967 to January 2010), CINAHL (EbscoHOST) (1982 to February 2010), and ERIC (CSA) (1965 to January 2010). We searched grey literature: theses/dissertation repositories, trials registers and Google Scholar (searched July 2010). We used additional search methods: examining reference lists and contacting authors.</p> <p>Selection criteria: Randomised controlled trials, quasi-randomised trials, controlled before and after studies and interrupted time series studies of interventions using email for communicating results of any diagnostic medical investigations to patients, and taking the form of 1) unsecured email 2) secure email or 3) web messaging. All healthcare professionals, patients and caregivers in all settings were considered.</p> <p>Data collection and analysis: Two review authors independently assessed the titles and abstracts of retrieved citations. No studies were identified for inclusion. Consequently, no data collection or analysis was possible.</p> <p>Main results: No studies met the inclusion criteria, therefore there are no results to report on the use of email for communicating results of diagnostic medical investigations to patients.</p> <p>Authors' conclusions: In the absence of included studies, we can draw no conclusions on the effects of using email for communicating results of diagnostic medical investigations to patients, and thus no recommendations for practice can be stipulated. Further well-designed research should be conducted to inform practice and policy for communicating patient results via email, as this is a developing area.</p&gt

Team Effect on Variation in Laboratory Utilization on Subspecialty Services

Background: The objective was to determine whether variation in laboratory utilization exists and whether physicians were responsible for a portion of this variation. Method: Variation in laboratory test ordering was collected on subspecialty services: the Medical Intensive Care Unit (MICU) and the Oncology Service. Ordinary least-squares regression was used to determine the effect of interns, residents, and attendings on the variation observed. Results: Variation in laboratory utilization attributable to physicians exists. Housestaff explain a proportion of this variation on each subspecialty service. Conclusions: Housestaff explain a large proportion of laboratory utilization attributable to physicians. This may represent an opportunity for education on systems-based practice and practice-based learning.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65005/1/09.Dine.Bellini.I.Acad.Med.pd

Redesigning Primary Care Processes to Improve the Offering of Mammography. The use of Clinic Protocols by Nonphysicians.

OBJECTIVE: To develop, within the framework of continuous quality improvement, new processes for offering mammography and determine whether protocols executed completely by nonphysicians would increase mammography utilization. DESIGN: A prospective follow-up study with patients from an intervention clinic and two control clinics. SETTING: Three general internal medicine clinics in a large, urban teaching hospital in Detroit, Michigan. PATIENTS/PARTICIPANTS: A total of 5,934 women, aged 40 through 75 years, making 16,546 visits to one of the clinics during the study period (September 1, 1992, through November 31, 1993). INTERVENTION: Medical assistants and licensed practical nurses in the intervention clinic were trained to identify women due for screening mammography, and to directly offer and order a mammogram if patients agreed. MEASUREMENTS AND MAIN RESULTS: Patients were considered up-to-date with screening if they had a mammogram within 1 year (if age 50-75) or 2 years (if age 40-49) prior to the visit or a mammogram within 60 days after the visit. The proportion of visits each month in which a woman was up-to-date with mammography was calculated using computerized billing records. Prior to the intervention, the proportion of visits in which women were up-to-date was 68% (95% confidence interval [CI] 63%, 73%) in the intervention clinic and 66% (95% CI 61%, 71%) in each of the control clinics. At the end of the evaluation, there was an absolute increase of 9% (95% CI 2%, 16%) in the intervention clinic, and a difference of 1% (95% CI -5%, 7%) in one of the control clinics and -2% (95% CI -3%, 5%) in the other. In the intervention clinic, the proportion of visits in which women were up-to-date with mammography increased over time and was consistent with a linear trend (p = .004). CONCLUSIONS: Redesigning clinic processes to make offering of mammography by medical assistants and licensed practical nurses a routine part of the clinic encounter can lead to mammography rates that are superior to those seen in physicians\u27 usual practice, even when screening levels are already fairly high. Physicians need not be considered the sole, or even the primary, member of the health care team who can effectively deliver some preventive health measures

The CT20 peptide causes detachment and death of metastatic breast cancer cells by promoting mitochondrial aggregation and cytoskeletal disruption

Metastasis accounts for most deaths from breast cancer, driving the need for new therapeutics that can impede disease progression. Rationally designed peptides that take advantage of cancer-specific differences in cellular physiology are an emerging technology that offer promise as a treatment for metastatic breast cancer. We developed CT20p, a hydrophobic peptide based on the C terminus of Bax that exhibits similarities with antimicrobial peptides, and previously reported that CT20p has unique cytotoxic actions independent of full-length Bax. In this study, we identified the intracellular actions of CT20p which precede cancer cell-specific detachment and death. Previously, we found that CT20p migrated in the heavy membrane fractions of cancer cell lysates. Here, using MDA-MB-231 breast cancer cells, we demonstrated that CT20p localizes to the mitochondria, leading to fusion-like aggregation and mitochondrial membrane hyperpolarization. As a result, the distribution and movement of mitochondria in CT20p-treated MDA-MB-231 cells was markedly impaired, particularly in cell protrusions. In contrast, CT20p did not associate with the mitochondria of normal breast epithelial MCF-10A cells, causing little change in the mitochondrial membrane potential, morphology or localization. In MDA-MB-231 cells, CT20p triggered cell detachment that was preceded by decreased levels of alpha 5 beta 1 integrins and reduced F-actin polymerization. Using folate-targeted nanoparticles to encapsulate and deliver CT20p to murine tumors, we achieved significant tumor regression within days of peptide treatment. These results suggest that CT20p has application in the treatment of metastatic disease as a cancer-specific therapeutic peptide that perturbs mitochondrial morphology and movement ultimately culminating in disruption of the actin cytoskeleton, cell detachment, and loss of cell viability

Acute Kidney Injury is Associated with Poor Lung Outcomes in Infants Born ≥32 Weeks of Gestational Age

Objective: This study aimed to evaluate the association between acute kidney injury (AKI) and lung outcomes in infants born ≥32 weeks of gestational age (GA). Study design: Secondary analysis of infants ≥32 weeks of GA in the assessment of worldwide acute kidney injury epidemiology in neonates (AWAKEN) retrospective cohort (n = 1,348). We used logistic regression to assess association between AKI and a composite outcome of chronic lung disease (CLD) or death at 28 days of age and linear regression to evaluate association between AKI and duration of respiratory support. Results: CLD occurred in 82/1,348 (6.1%) infants, while death occurred in 22/1,348 (1.6%); the composite of CLD/death occurred in 104/1,348 (7.7%). Infants with AKI had an almost five-fold increased odds of CLD/death, which remained after controlling for GA, maternal polyhydramnios, multiple gestations, 5-minute Apgar's score, intubation, and hypoxic-ischemic encephalopathy (adjusted odds ratio [OR] = 4.9, 95% confidence interval [CI]: 3.2-7.4; p < 0.0001). Infants with AKI required longer duration of respiratory support (count ratio = 1.59, 95% CI: 1.14-2.23, p = 0.003) and oxygen (count ratio = 1.43, 95% CI: 1.22-1.68, p < 0.0001) compared with those without AKI. Conclusion: AKI is associated with CLD/death and longer duration of respiratory support in infants born at ≥32 weeks of GA. Further prospective studies are needed to elucidate the pathophysiologic relationship

Acute Kidney Injury in Neonatal Encephalopathy: An Evaluation of the AWAKEN Database

Background: Acute kidney injury (AKI) is common in neonatal encephalopathy (NE) and is associated with worse outcomes. Our objectives were to determine the incidence, risk factors, and outcomes of AKI in infants with NE. Methods: We performed a retrospective analysis of infants ≥ 34 weeks' gestational age with a diagnosis of NE from the Analysis of Worldwide Acute Kidney injury Epidemiology in Neonates (AWAKEN) database. AKI was defined using the modified Kidney Disease Improving Global Outcomes criteria. Perinatal and postnatal factors were evaluated. Multivariate logistic and linear regressions were performed. Results: One hundred and thirteen patients with NE were included. 41.6% (47) developed AKI. Being born outside the admitting institution (OR 4.3; 95% CI 1.2-14.8; p = 0.02), intrauterine growth restriction (OR 10.3, 95% CI 1.1-100.5; p = 0.04), and meconium at delivery (OR 2.8, 95% CI 1.04-7.7; p = 0.04) conferred increased odds of AKI. After controlling for confounders, infants with AKI stayed in the hospital an average of 8.5 days longer than infants without AKI (95% CI 0.79-16.2 days; p = 0.03). Conclusions: In this multi-national analysis, several important perinatal factors were associated with AKI and infants with both NE and AKI had longer length of stay than NE alone. Future research aimed at early AKI detection, renoprotective management strategies, and understanding the long-term renal consequences is warranted in this high-risk group of patients