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

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

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 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

Acute Kidney Injury and Bronchopulmonary Dysplasia in Premature Neonates Born Less than 32 Weeks’ Gestation

Objective: This study aimed to evaluate the association between acute kidney injury (AKI) and bronchopulmonary dysplasia (BPD) in infants born <32 weeks of gestational age (GA). Study design: Present study is a secondary analysis of premature infants born at <32 weeks of GA in the Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates (AWAKEN) retrospective cohort (n = 546). We stratified by gestational age and used logistic regression to determine association between AKI and moderate or severe BPD/mortality. Results: Moderate or severe BPD occurred in 214 of 546 (39%) infants, while death occurred in 32 of 546 (6%); the composite of moderate or severe BPD/death occurred in 246 of 546 (45%). For infants born ≤29 weeks of gestation, the adjusted odds ratio (OR) of AKI and the primary outcome was 1.15 (95% confidence interval [CI] = 0.47-2.86; p = 0.76). Infants born between 29 and 32 weeks of gestation with AKI had four-fold higher odds of moderate or severe BPD/death that remained after controlling for multiple factors (adjusted OR = 4.21, 95% CI: 2.07-8.61; p < 0.001). Conclusion: Neonates born between 29 and 32 weeks who develop AKI had a higher likelihood of moderate or severe BPD/death than those without AKI. Further studies are needed to validate our findings and evaluate mechanisms of multiorgan injury

The frequency of missed test results and associated treatment delays in a highly computerized health system

<p>Abstract</p> <p>Background:</p> <p>Diagnostic errors associated with the failure to follow up on abnormal diagnostic studies ("missed results") are a potential cause of treatment delay and a threat to patient safety. Few data exist concerning the frequency of missed results and associated treatment delays within the Veterans Health Administration (VA).</p> <p>Objective:</p> <p>The primary objective of the current study was to assess the frequency of missed results and resulting treatment delays encountered by primary care providers in VA clinics.</p> <p>Methods:</p> <p>An anonymous on-line survey of primary care providers was conducted as part of the health systems ongoing quality improvement programs. We collected information from providers concerning their clinical effort (e.g., number of clinic sessions, number of patient visits per session), number of patients with missed abnormal test results, and the number and types of treatment delays providers encountered during the two week period prior to administration of our survey.</p> <p>Results:</p> <p>The survey was completed by 106 out of 198 providers (54 percent response rate). Respondents saw and average of 86 patients per 2 week period. Providers encountered 64 patients with missed results during the two week period leading up to the study and 52 patients with treatment delays. The most common missed results included imaging studies (29 percent), clinical laboratory (22 percent), anatomic pathology (9 percent), and other (40 percent). The most common diagnostic delays were cancer (34 percent), endocrine problems (26 percent), cardiac problems (16 percent), and others (24 percent).</p> <p>Conclusion:</p> <p>Missed results leading to clinically important treatment delays are an important and likely underappreciated source of diagnostic error.</p