Inhibition of ATM-directed antiviral responses by HIV-1 Vif.

Emerging evidence indicates that HIV-1 hijacks host DNA damage repair (DDR) pathways to facilitate multiple facets of virus replication. Canonically, HIV-1 engages proviral DDR responses through the accessory protein Vpr, which induces constitutive activation of DDR kinases ATM and ATR. However, in response to prolonged DDR signaling, ATM directly induces pro-inflammatory NF-κB signaling and activates multiple members of the TRIM family of antiviral restriction factors, several of which have been previously implicated in antagonizing retroviral and lentiviral replication. Here, we demonstrate that the HIV-1 accessory protein Vif blocks ATM-directed DNA repair processes, activation of NF-κB signaling responses, and TRIM protein phosphorylation. Vif function in ATM antagonism occurs in clinical isolates and in common HIV-1 Group M subtypes/clades circulating globally. Pharmacologic and functional studies combine to suggest that Vif blocks Vpr-directed activation of ATM but not ATR, signifying that HIV-1 utilizes discrete strategies to fine-tune DDR responses that promote virus replication while simultaneously inhibiting immune activation.

Advance Care Planning (ACP) in Medicare Beneficiaries with Heart Failure.

BACKGROUND: Heart failure is a leading cause of death in the USA, contributing to high expenditures near the end of life. Evidence remains lacking on whether billed advance care planning changes patterns of end-of-life healthcare utilization among patients with heart failure. Large-scale claims evaluation assessing billed advance care planning and end-of-life hospitalizations among patients with heart failure can fill evidence gaps to inform health policy and clinical practice. OBJECTIVE: Assess the association between billed advance care planning delivered and Medicare beneficiaries with heart failure upon the type and quantity of healthcare utilization in the last 30 days of life. DESIGN: This retrospective cross-sectional cohort study used Medicare fee-for-service claims from 2016 to 2020. PARTICIPANTS: A total of 48,466 deceased patients diagnosed with heart failure on Medicare. MAIN MEASURES: Billed advance care planning services between the last 12 months and last 30 days of life will serve as the exposure. The outcomes are end-of-life healthcare utilization and total expenditure in inpatient, outpatient, hospice, skilled nursing facility, and home healthcare services. KEY RESULTS: In the final cohort of 48,466 patients (median [IQR] age, 83 [76-89] years; 24,838 [51.2%] women; median [IQR] Charlson Comorbidity Index score, 4 [2-5]), 4406 patients had an advance care planning encounter. Total end-of-life expenditure among patients with billed advance care planning encounters was 19% lower (95% CI, 0.77-0.84) compared to patients without. Patients with billed advance care planning encounters had 2.65 times higher odds (95% CI, 2.47-2.83) of end-of-life outpatient utilization with a 33% higher expected total outpatient expenditure (95% CI, 1.24-1.42) compared with patients without a billed advance care planning encounter. CONCLUSIONS: Billed advance care planning delivery to individuals with heart failure occurs infrequently. Prioritizing billed advance care planning delivery to these individuals may reduce total end-of-life expenditures and end-of-life inpatient expenditures through promoting use of outpatient end-of-life services, including home healthcare and hospice.

Vividness as the similarity between generated imagery and an internal model.

Vividness in visual mental imagery has been relatively under-explored compared to imagery's representational format and neural mechanisms. In this paper, we take a deeper look at vividness and suggest that in re-framing it, we can potentially reconcile disparate findings regarding visual cortex activation during imagery. Unlike traditional views of vividness that define the concept in terms of perception, we frame vividness in terms of imagery's relation to an internal model; the closer the generated imagery is to this model, the more vivid it is. This view is considered alongside existing neuroscientific, psychological, and philosophical research, as well as directions for future research.

Watching the watchmen: changing tides in the oversight of medical assistance in dying.

The recent wave of medical assistance in dying legalisation raises questions about proper oversight of the practice as new systems for data collection, case assessment and public reporting emerge. Newer systems, such as in Spain, New Zealand and Colombia, are eschewing the retrospective approach used for case assessment in older systems, particularly those in the Netherlands, Belgium and the USA, in favour of an approach requiring more extensive review prior to the procedure. This shift aims to increase compliance with each jurisdiction's specific safeguards and legal criteria as well as to protect vulnerable patients, but also risks stifling access to the practice and increasing administrative burden on clinicians and patients. Newer systems also tend to favour more extensive data collection than older systems, while failing to be as transparent with public reporting. Inconsistency in data collection and public reporting make it difficult for researchers, policymakers and the public to assess the practice and help achieve a balance between access and compliance. Research on oversight activities is sparse, and there is a need for clarity to determine how best to handle violations of the law and how to create best practices.

Screening for Latent Tuberculosis Infection in Adults: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Latent tuberculosis infection (LTBI) can progress to active tuberculosis disease, causing morbidity and mortality. Objective: To review the evidence on benefits and harms of screening for and treatment of LTBI in adults to inform the US Preventive Services Task Force (USPSTF). Data Sources: PubMed/MEDLINE, Cochrane Library, and trial registries through December 3, 2021; references; experts; literature surveillance through January 20, 2023. Study Selection: English-language studies of LTBI screening, LTBI treatment, or accuracy of the tuberculin skin test (TST) or interferon-gamma release assays (IGRAs). Studies of LTBI screening and treatment for public health surveillance or disease management were excluded. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings; meta-analyses conducted when a sufficient number of similar studies were available. Main Outcomes and Measures: Screening test accuracy; development of active tuberculosis disease, transmission, quality of life, mortality, and harms. Results: A total of 113 publications were included (112 studies; N = 69 009). No studies directly evaluated the benefits and harms of screening. Pooled estimates for sensitivity of the TST were 0.80 (95% CI, 0.74-0.87) at the 5-mm induration threshold, 0.81 (95% CI, 0.76-0.87) at the 10-mm threshold, and 0.60 (95% CI, 0.46-0.74) at the 15-mm threshold. Pooled estimates for sensitivity of IGRA tests ranged from 0.81 (95% CI, 0.79-0.84) to 0.90 (95% CI, 0.87-0.92). Pooled estimates for specificity of screening tests ranged from 0.95 to 0.99. For treatment of LTBI, a large (n = 27 830), good-quality randomized clinical trial found a relative risk (RR) for progression to active tuberculosis at 5 years of 0.35 (95% CI, 0.24-0.52) for 24 weeks of isoniazid compared with placebo (number needed to treat, 112) and an increase in hepatotoxicity (RR, 4.59 [95% CI, 2.03-10.39]; number needed to harm, 279). A previously published meta-analysis reported that multiple regimens were efficacious compared with placebo or no treatment. Meta-analysis found greater risk for hepatotoxicity with isoniazid than with rifampin (pooled RR, 4.22 [95% CI, 2.21-8.06]; n = 7339). Conclusions and Relevance: No studies directly evaluated the benefits and harms of screening for LTBI compared with no screening. TST and IGRAs were moderately sensitive and highly specific. Treatment of LTBI with recommended regimens reduced the risk of progression to active tuberculosis. Isoniazid was associated with higher rates of hepatotoxicity than placebo or rifampin.

Pharmacotherapy for Alcohol Use Disorder: A Systematic Review and Meta-Analysis.

Importance: Alcohol use disorder affects more than 28.3 million people in the United States and is associated with increased rates of morbidity and mortality. Objective: To compare efficacy and comparative efficacy of therapies for alcohol use disorder. Data Sources: PubMed, the Cochrane Library, the Cochrane Central Trials Registry, PsycINFO, CINAHL, and EMBASE were searched from November 2012 to September 9, 2022 Literature was subsequently systematically monitored to identify relevant articles up to August 14, 2023, and the PubMed search was updated on August 14, 2023. Study Selection: For efficacy outcomes, randomized clinical trials of at least 12 weeks' duration were included. For adverse effects, randomized clinical trials and prospective cohort studies that compared drug therapies and reported health outcomes or harms were included. Data Extraction and Synthesis: Two reviewers evaluated each study, assessed risk of bias, and graded strength of evidence. Meta-analyses used random-effects models. Numbers needed to treat were calculated for medications with at least moderate strength of evidence for benefit. Main Outcomes and Measures: The primary outcome was alcohol consumption. Secondary outcomes were motor vehicle crashes, injuries, quality of life, function, mortality, and harms. Results: Data from 118 clinical trials and 20 976 participants were included. The numbers needed to treat to prevent 1 person from returning to any drinking were 11 (95% CI, 1-32) for acamprosate and 18 (95% CI, 4-32) for oral naltrexone at a dose of 50 mg/d. Compared with placebo, oral naltrexone (50 mg/d) was associated with lower rates of return to heavy drinking, with a number needed to treat of 11 (95% CI, 5-41). Injectable naltrexone was associated with fewer drinking days over the 30-day treatment period (weighted mean difference, -4.99 days; 95% CI, -9.49 to -0.49 days) Adverse effects included higher gastrointestinal distress for acamprosate (diarrhea: risk ratio, 1.58; 95% CI, 1.27-1.97) and naltrexone (nausea: risk ratio, 1.73; 95% CI, 1.51-1.98; vomiting: risk ratio, 1.53; 95% CI, 1.23-1.91) compared with placebo. Conclusions and Relevance: In conjunction with psychosocial interventions, these findings support the use of oral naltrexone at 50 mg/d and acamprosate as first-line pharmacotherapies for alcohol use disorder.

Contribution of classical complement activation and IgM to the control of Rickettsia infection.

Pathogenic Rickettsia are obligate intracellular bacteria and the etiologic agents of many life-threatening infectious diseases. Due to the serious nature of these infections, it is imperative to both identify the responsive immune sensory pathways and understand the associated immune mechanisms that restrict Rickettsia proliferation. Previous studies have demonstrated that the mammalian complement system is both activated during Rickettsia infection and contributes to the immune response to infection. To further define this component of the mammalian anti-Rickettsia immune response, we sought to identify the mechanism(s) of complement activation during Rickettsia infection. We have employed a series of in vitro and in vivo models of infection to investigate the role of the classical complement activation pathway during Rickettsia infection. Depletion or elimination of complement activity demonstrates that both C1q and pre-existing IgM contribute to complement activation; thus implicating the classical complement system in Rickettsia-mediated complement activation. Elimination of the classical complement pathway from mice increases susceptibility to R. australis infection with both increased bacterial loads in multiple tissues and decreased immune activation markers. This study highlights the role of the classical complement pathway in immunity against Rickettsia and implicates resident Rickettsia-responsive IgM in the response to infection.

Screening for Eating Disorders in Adolescents and Adults: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Eating disorders are associated with adverse health and social outcomes. Objective: To review the evidence on screening for eating disorders in adolescents and adults to inform the US Preventive Services Task Force. Data Sources: MEDLINE, Cochrane Library, PsycINFO, and trial registries through December 19, 2020; surveillance through January 1, 2022. Study Selection: English-language studies of screening test accuracy, randomized clinical trials (RCTs) of screening or interventions for eating disorders in populations with screen-detected or previously untreated eating disorders (trials limited to populations who are underweight were ineligible). Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality. Meta-analysis of test accuracy studies and intervention trials. Main Outcomes and Measures: Test accuracy, eating disorder symptom severity, quality of life, depression, and harms. Results: Fifty-seven studies were included (N = 10 773); 3 (n = 1073) limited to adolescents (mean or median age, 14-15 years). No study directly evaluated the benefits and harms of screening. Seventeen studies (n = 6804) evaluated screening test accuracy. The SCOFF questionnaire (cut point ≥2) had a pooled sensitivity of 84% (95% CI, 74% to 90%) and pooled specificity of 80% (95% CI, 65% to 89%) in adults (10 studies, n = 3684). Forty RCTs (n = 3969) evaluated interventions for eating disorders; none enrolled a screen-detected population. Lisdexamfetamine for binge eating disorder (4 RCTs; n = 900) was associated with larger reductions in eating disorder symptom severity on the Yale-Brown Obsessive Compulsive Scale modified for binge eating (YBOCS-BE) than placebo (pooled mean difference, -5.75 [95% CI, -8.32 to -3.17]). Two RCTs (n = 465) of topiramate for binge eating disorder found larger reductions in YBOCS-BE scores associated with topiramate than placebo, from -6.40 (95% CI, -8.16 to -4.64) to -2.55 (95% CI, -4.22 to -0.88). Nine pharmacotherapy trials (n = 2006) reported on harms. Compared with placebo, lisdexamfetamine was associated with higher rates of dry mouth, headache, and insomnia, and topiramate was associated with higher rates of paresthesia, taste perversion, confusion, and concentration difficulty. Twenty-four trials (n = 1644) assessed psychological interventions. Guided self-help for binge eating disorder improved eating disorder symptom severity more than control (pooled standardized mean difference, -0.96 [95% CI, -1.26 to -0.67]) (5 studies, n = 391). Evidence on other interventions was limited. Conclusions and Relevance: No studies directly assessed the benefits and harms of screening. The SCOFF questionnaire had adequate accuracy for detecting eating disorders among adults. No treatment trials enrolled screen-detected populations; guided self-help, lisdexamfetamine, and topiramate were effective for reducing eating disorder symptom severity among referred populations with binge eating disorder, but pharmacotherapies were also associated with harms.

Screening for Prediabetes and Type 2 Diabetes in Children and Adolescents: Evidence Report and Systematic Review for the US Preventive Services Task Force.

Importance: Of youths diagnosed with type 2 diabetes, many develop microvascular complications by young adulthood. Objective: To review the evidence on benefits and harms of screening children and adolescents for prediabetes and type 2 diabetes to inform the US Preventive Services Task Force (USPSTF). Data Sources: PubMed/MEDLINE, Cochrane Library, and trial registries through May 3, 2021; references; experts; literature surveillance through July 22, 2022. Study Selection: English-language controlled studies evaluating screening or interventions for prediabetes or type 2 diabetes that was screen detected or recently diagnosed. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings. Main Outcomes and Measures: Mortality, cardiovascular morbidity, diabetes-related morbidity, development of diabetes, quality of life, and harms. Results: This review included 8 publications (856 participants; mean age, 14 years [range, 10-17 years]). Of those, 6 were from the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study. No eligible studies directly evaluated the benefits or harms of screening. One randomized clinical trial (RCT) (TODAY; n = 699 adolescents with obesity; mean age, 14 years) comparing metformin, metformin plus rosiglitazone, and metformin plus lifestyle intervention reported that 2 youths with recently diagnosed diabetes developed kidney impairment (0 vs 1 vs 1, respectively; P > .99) and 11 developed diabetic ketoacidosis (5 vs 3 vs 3, respectively; P = .70). One RCT of 75 adolescents (mean age, 13 years) with obesity with prediabetes compared an intensive lifestyle intervention with standard care and reported that no participants in either group developed diabetes, although follow-up was only 6 months. Regarding harms of interventions, 2 RCTs assessing different comparisons enrolled youths with recently diagnosed diabetes. Major hypoglycemic events were reported by less than 1% of participants. Minor hypoglycemic events were more common among youths treated with metformin plus rosiglitazone than among those treated with metformin or metformin plus lifestyle intervention in TODAY (8.2% vs 4.3% vs 3.4%, P = .05). In 1 study, gastrointestinal adverse events were more commonly reported by those taking metformin than by those taking placebo (abdominal pain: 25% vs 12%; nausea/vomiting: 17% vs 10%; P not reported). Conclusions and Relevance: No eligible studies directly evaluated the benefits or harms of screening for prediabetes and type 2 diabetes in children and adolescents. For youths with prediabetes or recently diagnosed (not screen-detected) diabetes, the only eligible trials reported few health outcomes and found no difference between groups, although evidence was limited by substantial imprecision and a duration of follow-up likely insufficient to assess health outcomes.

Identification of Zika Virus Inhibitors Using Homology Modeling and Similarity-Based Screening to Target Glycoprotein E.

The World Health Organization has designated Zika virus (ZIKV) as a dangerous, mosquito-borne pathogen that can cause severe developmental defects. The primary goal of this work was identification of small molecules as potential ZIKV inhibitors that target the viral envelope glycoprotein (ZIKV E) involved in membrane fusion and viral entry. A homology model of ZIKV E containing the small molecule ß-octyl glucoside (BOG) was constructed, on the basis of an analogous X-ray structure from dengue virus, and >4 million commercially available compounds were computationally screened using the program DOCK6. A key feature of the screen involved the use of similarity-based scoring to identify inhibitor candidates that make similar interaction energy patterns (molecular footprints) as the BOG reference. Fifty-three prioritized compounds underwent experimental testing using cytotoxicity, cell viability, and tissue culture infectious dose 50% (TCID50) assays. Encouragingly, relative to a known control (NITD008), six compounds were active in both the cell viability assay and the TCID50 infectivity assay, and they showed activity in a third caspase activity assay. In particular, compounds 8 and 15 (tested at 25 µM) and compound 43 (tested at 10 µM) appeared to provide significant protection to infected cells, indicative of anti-ZIKV activity. Overall, the study highlights how similarity-based scoring can be leveraged to computationally identify potential ZIKV E inhibitors that mimic a known reference (in this case BOG), and the experimentally verified hits provide a strong starting point for further refinement and optimization efforts.

Physician adherence to clinical guidelines in euthanasia and assisted suicide in the Netherlands: a qualitative study.

BACKGROUND: Euthanasia and assisted suicide laws in the Netherlands require physicians meet clinical guidelines when performing the practice to ensure death is peaceful and painless. Despite oversight by the regional review committees over each case, little research exists into the frequency of guideline deviation and the reasons for nonadherence. METHODS: Cases reported and reviewed between 2012 and 2017 that did not meet due medical care were analysed for thematic content. Semistructured interviews were conducted with 11 Dutch physicians on their experience with the clinical and pharmacological elements of euthanasia and assisted suicide, their interaction and comportment with the recommended guidelines, and reasons why guideline deviation might occur. Reported case reviews and interviews were used to obtain themes and subthemes to understand how and why deviations from clinical guidelines happened. RESULTS: Violations of due medical care were found in 42 (0.07%) of reported cases. The regional review committees found physicians in violation of due medical care mostly for inadequate confirmation of coma-induction and deviations from recommended drug dosages. Physicians reported that they rarely deviated from the guidelines, with the most common reasons being concern for the patient's family, concern over the drug efficacy, mistrust in the provided guidelines, or relying on the poor advice of pharmacists or hospital administrators. CONCLUSIONS: Deviations from the guidelines and violations of due medical care are rare, but should nonetheless be monitored and prevented. A few areas for improvement include skills training for physicians, consistency between review committee rulings, and further clarity on dosage recommendations.

Are movement-based classification systems more effective than therapeutic exercise or guideline based care in improving outcomes for patients with chronic low back pain? A systematic review.

Objectives: The purpose of this systematic review was to determine if movement-based classification (MBC) systems are more effective than therapeutic exercise or guideline-based care (GBC) in improving outcomes in patients with low back pain (LBP) based upon randomized clinical trials (RCT) with moderate to high methodological quality and low to moderate risk of bias. Methods: The search strategy was developed by a librarian experienced in systematic review methodology and peer reviewed by a second research librarian. The following databases were searched from their inception to May 17, 2018: PubMed, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform. The identified RCTs with a PEDro score of ≥6 were screened and assessed for risk of bias by two blinded individual reviewers using Covidence. Results: Seven studies were identified that had moderate-to-high methodological quality. One of the studies was identified as having a high risk of bias. Of the six studies that remained, only one study reported finding a statistically significant difference at the immediate follow-up that was not clinically significant. There was no significance at 6 and 12 months. Discussion: There is a paucity of moderate to high methodological quality RCTs with similar methodology that compare MBC to standard of care treatments for patients with LBP. Studies with moderate to high methodological quality that have a low risk of bias do not support MBCs as being superior to general exercise or GBC in the treatment of nonradicular LBP. Level of Evidence: 1a.

Immunity against the Obligate Intracellular Bacterial Pathogen Rickettsia australis Requires a Functional Complement System.

The complement system has a well-defined role in deterring blood-borne infections. However, complement is not entirely efficacious, as several bacterial pathogens, including some obligate intracellular pathogens, have evolved mechanisms for resistance. It is presumed that obligate intracellular bacteria evade complement attack by residing within a host cell; however, recent studies have challenged this presumption. Here, we demonstrate that the complement system is activated during infection with the obligate intracellular bacterium Rickettsia australis and that genetic ablation of complement increases susceptibility to infection. Interaction of Rickettsia australis with serum-borne complement leads to activation of the complement cascade, producing three effector mechanisms that could negatively influence R. australis. The C9-dependent membrane attack complex can lead to deposition of a bacteriolytic membrane pore on the bacteria, but this system does not contribute to control of rickettsial infection. Similarly, complement receptor (CR1/2)-dependent opsonophagocytosis may lead to engulfment and killing of the bacteria, but this system is also dispensable for immunity. Nevertheless, intact complement is essential for naturally acquired and antibody-mediated immunity to Rickettsia infection. Comparison of infection in mice lacking the central complement protein C3 with infection in their wild-type counterparts demonstrated decreases in gamma interferon (IFN-γ) production, IgG secretion, and spleen hyperplasia in animals lacking complement. The correlation between loss of secondary immune functions and loss of complement indicates that the proinflammatory signaling components of the complement system, and not membrane attack complex or opsonophagocytosis, contribute to the immune response to this pathogen.

A novel high-throughput activity assay for the Trypanosoma brucei editosome enzyme REL1 and other RNA ligases.

The protist parasite Trypanosoma brucei causes Human African trypanosomiasis (HAT), which threatens millions of people in sub-Saharan Africa. Without treatment the infection is almost always lethal. Current drugs for HAT are difficult to administer and have severe side effects. Together with increasing drug resistance this results in urgent need for new treatments. T. brucei and other trypanosomatid pathogens require a distinct form of post-transcriptional mRNA modification for mitochondrial gene expression. A multi-protein complex called the editosome cleaves mitochondrial mRNA, inserts or deletes uridine nucleotides at specific positions and re-ligates the mRNA. RNA editing ligase 1 (REL1) is essential for the re-ligation step and has no close homolog in the mammalian host, making it a promising target for drug discovery. However, traditional assays for RELs use radioactive substrates coupled with gel analysis and are not suitable for high-throughput screening of compound libraries. Here we describe a fluorescence-based REL activity assay. This assay is compatible with a 384-well microplate format and sensitive, satisfies statistical criteria for high-throughput methods and is readily adaptable for other polynucleotide ligases. We validated the assay by determining kinetic properties of REL1 and by identifying REL1 inhibitors in a library of small, pharmacologically active compounds.

Bitopic Sphingosine 1-Phosphate Receptor 3 (S1P3) Antagonist Rescue from Complete Heart Block: Pharmacological and Genetic Evidence for Direct S1P3 Regulation of Mouse Cardiac Conduction.

The molecular pharmacology of the G protein-coupled receptors for sphingosine 1-phosphate (S1P) provides important insight into established and new therapeutic targets. A new, potent bitopic S1P3 antagonist, SPM-354, with in vivo activity, has been used, together with S1P3-knockin and S1P3-knockout mice to define the spatial and functional properties of S1P3 in regulating cardiac conduction. We show that S1P3 is a key direct regulator of cardiac rhythm both in vivo and in isolated perfused hearts. 2-Amino-2-[2-(4-octylphenyl)ethyl]propane-1,3-diol in vivo and S1P in isolated hearts induced a spectrum of cardiac effects, ranging from sinus bradycardia to complete heart block, as measured by a surface electrocardiogram in anesthetized mice and in volume-conducted Langendorff preparations. The agonist effects on complete heart block are absent in S1P3-knockout mice and are reversed in wild-type mice with SPM-354, as characterized and described here. Homologous knockin of S1P3-mCherry is fully functional pharmacologically and is strongly expressed by immunohistochemistry confocal microscopy in Hyperpolarization Activated Cyclic Nucleotide Gated Potassium Channel 4 (HCN4)-positive atrioventricular node and His-Purkinje fibers, with relative less expression in the HCN4-positive sinoatrial node. In Langendorff studies, at constant pressure, SPM-354 restored sinus rhythm in S1P-induced complete heart block and fully reversed S1P-mediated bradycardia. S1P3 distribution and function in the mouse ventricular cardiac conduction system suggest a direct mechanism for heart block risk that should be further studied in humans. A richer understanding of receptor and ligand usage in the pacemaker cells of the cardiac system is likely to be useful in understanding ventricular conduction in health, disease, and pharmacology.

Nonselective Persistence of a Rickettsia conorii Extrachromosomal Plasmid during Mammalian Infection.

Scientific analysis of the genus Rickettsia is undergoing a rapid period of change with the emergence of viable genetic tools. The development of these tools for the mutagenesis of pathogenic bacteria will permit forward genetic analysis of Rickettsia pathogenesis. Despite these advances, uncertainty still remains regarding the use of plasmids to study these bacteria in in vivo mammalian models of infection, namely, the potential for virulence changes associated with the presence of extrachromosomal DNA and nonselective persistence of plasmids in mammalian models of infection. Here, we describe the transformation of Rickettsia conorii Malish 7 with the plasmid pRam18dRGA[AmTrCh]. Transformed R. conorii stably maintains this plasmid in infected cell cultures, expresses the encoded fluorescent proteins, and exhibits growth kinetics in cell culture similar to those of nontransformed R. conorii. Using a well-established murine model of fatal Mediterranean spotted fever, we demonstrate that R. conorii(pRam18dRGA[AmTrCh]) elicits the same fatal outcomes in animals as its untransformed counterpart and, importantly, maintains the plasmid throughout infection in the absence of selective antibiotic pressure. Interestingly, plasmid-transformed R. conorii was readily observed both in endothelial cells and within circulating leukocytes. Together, our data demonstrate that the presence of an extrachromosomal DNA element in a pathogenic rickettsial species does not affect either in vitro proliferation or in vivo infectivity in models of disease and that plasmids such as pRam18dRGA[AmTrCh] are valuable tools for the further genetic manipulation of pathogenic rickettsiae.

RC1339/APRc from Rickettsia conorii is a novel aspartic protease with properties of retropepsin-like enzymes.

Members of the species Rickettsia are obligate intracellular, gram-negative, arthropod-borne pathogens of humans and other mammals. The life-threatening character of diseases caused by many Rickettsia species and the lack of reliable protective vaccine against rickettsioses strengthens the importance of identifying new protein factors for the potential development of innovative therapeutic tools. Herein, we report the identification and characterization of a novel membrane-embedded retropepsin-like homologue, highly conserved in 55 Rickettsia genomes. Using R. conorii gene homologue RC1339 as our working model, we demonstrate that, despite the low overall sequence similarity to retropepsins, the gene product of rc1339 APRc (for Aspartic Protease from Rickettsia conorii) is an active enzyme with features highly reminiscent of this family of aspartic proteases, such as autolytic activity impaired by mutation of the catalytic aspartate, accumulation in the dimeric form, optimal activity at pH 6, and inhibition by specific HIV-1 protease inhibitors. Moreover, specificity preferences determined by a high-throughput profiling approach confirmed common preferences between this novel rickettsial enzyme and other aspartic proteases, both retropepsins and pepsin-like. This is the first report on a retropepsin-like protease in gram-negative intracellular bacteria such as Rickettsia, contributing to the analysis of the evolutionary relationships between the two types of aspartic proteases. Additionally, we have also shown that APRc is transcribed and translated in R. conorii and R. rickettsii and is integrated into the outer membrane of both species. Finally, we demonstrated that APRc is sufficient to catalyze the in vitro processing of two conserved high molecular weight autotransporter adhesin/invasion proteins, Sca5/OmpB and Sca0/OmpA, thereby suggesting the participation of this enzyme in a relevant proteolytic pathway in rickettsial life-cycle. As a novel bona fide member of the retropepsin family of aspartic proteases, APRc emerges as an intriguing target for therapeutic intervention against fatal rickettsioses.

A systematic review of orthopaedic manual therapy randomized clinical trials quality.

Study Design: Systematic review and meta-analysis. Objectives: To conduct a systematic review and meta-analysis of randomized clinical trials (RCTs) in the orthopaedic manual therapy (OMT) literature from January 2010 to June 2014 in order to determine if the CONSORT checklist and Cochrane Risk of Bias (RoB) assessment tools: (1) are reliable; (2) have improved the reporting and decreased the risk of bias in RCTs in the OMT literature; (3) differ based on journal impact factor (JIF); and (4) scores are associated with each other. Background: The CONSORT statement is used to improve the accuracy of reporting within RCTs. The Cochrane RoB tool was designed to assess the risk of bias within RCTs. To date, no evaluation of the quality of reporting and risk of bias in OMT RCTs has been published. Methods: Relevant RCTs were identified by a literature review from January 2010 to June 2014. The identified RCTs were assessed by two individual reviewers utilizing the 2010 CONSORT checklist and the RoB tool. Agreement and a mean composite total score for each tool were attained in order to determine if the CONSORT and RoB tools were reliable and varied by year and impact factor. Results: A total of 72 RCTs in the OMT literature were identified. A number of categories within the CONSORT and RoB tools demonstrated prevalence-adjusted bias-adjusted kappa (PABAK) scores of less than 0.20 and from 0.20 to 0.40. The total CONSORT and RoB scores were correlated to each other (r = 0.73; 95% CI 0.60 to 0.82; p < 0.0001). There were no statistically significant differences in CONSORT or RoB scores by year. There was a statistically significant correlation between both CONSORT scores and JIF (r = 0.64, 95% CI 0.47 to 0.76; p < 0.0001), and between RoB scores and JIF (r = 0.42, 95% confidence interval 0.21-0.60; p < 0.001). There was not a statistically significant correlation between JIF and year of publication. Conclusion: Our findings suggest that the CONSORT and RoB have a number of items that are unclear and unreliable, and that the quality of reporting in OMT trials has not improved in recent years. Improvements in reporting are necessary to allow advances in OMT practice. Level of Evidence: 1A.

Manual unloading of the lumbar spine: can it identify immediate responders to mechanical traction in a low back pain population? A study of reliability and criterion referenced predictive validity.

BACKGROUND: To date, no research has examined the reliability or predictive validity of manual unloading tests of the lumbar spine to identify potential responders to lumbar mechanical traction. PURPOSE: To determine: (1) the intra and inter-rater reliability of a manual unloading test of the lumbar spine and (2) the criterion referenced predictive validity for the manual unloading test. METHODS: Ten volunteers with low back pain (LBP) underwent a manual unloading test to establish reliability. In a separate procedure, 30 consecutive patients with LBP (age 50·86±11·51) were assessed for pain in their most provocative standing position (visual analog scale (VAS) 49·53±25·52 mm). Patients were assessed with a manual unloading test in their most provocative position followed by a single application of intermittent mechanical traction. Post traction, pain in the provocative position was reassessed and utilized as the outcome criterion. RESULTS: The test of unloading demonstrated substantial intra and inter-rater reliability K = 1·00, P = 0·002, K = 0·737, P = 0·001, respectively. There were statistically significant within group differences for pain response following traction for patients with a positive manual unloading test (P<0·001), while patients with a negative manual unloading test did not demonstrate a statistically significant change (P>0·05). There were significant between group differences for proportion of responders to traction based on manual unloading response (P = 0·031), and manual unloading response demonstrated a moderate to strong relationship with traction response Phi = 0·443, P = 0·015. DISCUSSION AND CONCLUSION: The manual unloading test appears to be a reliable test and has a moderate to strong correlation with pain relief that exceeds minimal clinically important difference (MCID) following traction supporting the validity of this test.

Pathogenic Rickettsia species acquire vitronectin from human serum to promote resistance to complement-mediated killing.

Bacteria of the genus Rickettsia are transmitted from arthropod vectors and primarily infect cells of the mammalian endothelial system. Throughout this infectious cycle, the bacteria are exposed to the deleterious effects of serum complement. Using Rickettsia conorii, the etiologic agent of Mediterranean spotted fever (MSF), as a model rickettsial species, we have previously demonstrated that this class of pathogen interacts with human factor H to mediate partial survival in human serum. Herein, we demonstrate that R. conorii also interacts with the terminal complement complex inhibitor vitronectin (Vn). We further demonstrate that an evolutionarily conserved rickettsial antigen, Adr1/RC1281, interacts with human vitronectin and is sufficient to mediate resistance to serum killing when expressed at the outer-membrane of serum sensitive Escherichia coli. Adr1 is an integral outer-membrane protein whose structure is predicted to contain eight membrane-embedded ß-strands and four 'loop' regions that are exposed to extracellular milieu. Site-directed mutagenesis of Adr1 revealed that at least two predicted 'loop' regions are required to mediate resistance to complement-mediatedkilling and vitronectin acquisition. These results demonstrate that rickettsial species have evolved multiple mechanisms to evade complement deposition and that evasion of killing in serum is an evolutionarily conserved virulence attribute for this genus of obligate intracellular pathogens.