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Study of GABA in Healthy Volunteers: Pharmacokinetics and Pharmacodynamics

Fri, 02/26/2016 - 2:04pm

Preclinical studies show that GABA exerts anti-diabetic effects in rodent models of type 1 diabetes. Because little is known about its absorption and effects in humans, we investigated the pharmacokinetics and pharmacodynamics of GABA in healthy volunteers. Twelve subjects were subjected to an open-labeled, three-period trial involving sequential oral administration of placebo, 2 g GABA once, and 2 g GABA three times/day for 7 days, with a 7-day washout between each period. GABA was rapidly absorbed (Tmax: 0.5 ~ 1 h) with the half-life (t1/2) of 5 h. No accumulation was observed after repeated oral GABA administration for 7 days. Remarkably, GABA significantly increased circulating insulin levels in the subjects under either fasting (1.6-fold, single dose; 2.0-fold, repeated dose; p < 0.01) or fed conditions (1.4-fold, single dose; 1.6-fold, repeated dose; p < 0.01). GABA also increased glucagon levels only under fasting conditions (1.3-fold, single dose, p < 0.05; 1.5-fold, repeated dose, p < 0.01). However, there were no significant differences in the insulin-to-glucagon ratio and no significant change in glucose levels in these healthy subjects during the study period. Importantly, GABA significantly decreased glycated albumin levels in the repeated dosing period. Subjects with repeated dosing showed an elevated incidence of minor adverse events in comparison to placebo or the single dosing period, most notably transient discomforts such as dizziness and sore throat. However, there were no serious adverse events observed throughout the study. Our data show that GABA is rapidly absorbed and tolerated in human beings; its endocrine effects, exemplified by increasing islet hormonal secretion, suggest potential therapeutic benefits for diabetes.

Hyperspectral Imaging as an Early Biomarker for Radiation Exposure and Microcirculatory Damage

Fri, 02/26/2016 - 2:04pm

BACKGROUND: Radiation exposure can lead to detrimental effects in skin microcirculation. The precise relationship between radiation dose received and its effect on cutaneous perfusion still remains controversial. Previously, we have shown that hyperspectral imaging (HSI) is able to demonstrate long-term reductions in cutaneous perfusion secondary to chronic microvascular injury. This study characterizes the changes in skin microcirculation in response to varying doses of ionizing radiation and investigates these microcirculatory changes as a possible early non-invasive biomarker that may correlate with the extent of long-term microvascular damage.

METHODS: Immunocompetent hairless mice (n = 66) were exposed to single fractions of superficial beta-irradiation in doses of 0, 5, 10, 20, 35, or 50 Gy. A HSI device was utilized to measure deoxygenated hemoglobin levels in irradiated and control areas. HSI measurements were performed at baseline before radiation exposure and for the first 3 days post-irradiation. Maximum macroscopic skin reactions were graded, and histological assessment of cutaneous microvascular densities at 4 weeks post-irradiation was performed in harvested tissue by CD31 immunohistochemistry.

RESULTS: CD31 immunohistochemistry demonstrated a significant correlation (r = 0.90, p < 0.0001) between dose and vessel density reduction at 4 weeks. Using HSI analysis, early changes in deoxygenated hemoglobin levels were observed during the first 3 days post-irradiation in all groups. These deoxygenated hemoglobin changes varied proportionally with dose (r = 0.98, p < 0.0001) and skin reactions (r = 0.98, p < 0.0001). There was a highly significant correlation (r = 0.91, p < 0.0001) between these early changes in deoxygenated hemoglobin and late vascular injury severity assessed at the end of 4 weeks.

CONCLUSION: Radiation dose is directly correlated with cutaneous microvascular injury severity at 4 weeks in our model. Early post-exposure measurement of cutaneous deoxygenated hemoglobin levels may be a useful biomarker for radiation dose reconstruction and predictor for chronic microvascular injury.

Current questions and possible controversies in autophagy

Fri, 02/26/2016 - 2:04pm

Interest in autophagy has exploded over the last decade, with publications highlighting crosstalk with several other cellular processes including secretion, endocytosis, and cell suicide pathways including apoptosis. Autophagy proteins have also been implicated in other cellular processes independently of their roles in autophagy, creating complexities in the interpretation of autophagy (Atg) mutant gene data. Interestingly, this self-eating process is a survival mechanism that can also promote cell death, but when and how autophagy may 'switch' its function is still under debate. Indeed, there are currently many models of how autophagy actually influences cell death. In this review, we highlight some outstanding questions and possible controversies in the autophagy field.

An emerging role for prdm family genes in dorsoventral patterning of the vertebrate nervous system

Fri, 02/26/2016 - 2:04pm

The embryonic vertebrate neural tube is divided along its dorsoventral (DV) axis into eleven molecularly discrete progenitor domains. Each of these domains gives rise to distinct neuronal cell types; the ventral-most six domains contribute to motor circuits, while the five dorsal domains contribute to sensory circuits. Following the initial neurogenesis step, these domains also generate glial cell types-either astrocytes or oligodendrocytes. This DV pattern is initiated by two morphogens-Sonic Hedgehog released from notochord and floor plate and Bone Morphogenetic Protein produced in the roof plate-that act in concentration gradients to induce expression of genes along the DV axis. Subsequently, these DV-restricted genes cooperate to define progenitor domains and to control neuronal cell fate specification and differentiation in each domain. Many genes involved in this process have been identified, but significant gaps remain in our understanding of the underlying genetic program. Here we review recent work identifying members of the Prdm gene family as novel regulators of DV patterning in the neural tube. Many Prdm proteins regulate transcription by controlling histone modifications (either via intrinsic histone methyltransferase activity, or by recruiting histone modifying enzymes). Prdm genes are expressed in spatially restricted domains along the DV axis of the neural tube and play important roles in the specification of progenitor domains, as well as in the subsequent differentiation of motor neurons and various types of interneurons. Strikingly, Prdm proteins appear to function by binding to, and modulating the activity of, other transcription factors (particularly bHLH proteins). The identity of key transcription factors in DV patterning of the neural tube has been elucidated previously (e.g. the nkx, bHLH and pax families), but it now appears that an additional family is also required and that it acts in a potentially novel manner.

Tocilizumab in early progressive rheumatoid arthritis: FUNCTION, a randomised controlled trial

Fri, 02/26/2016 - 2:03pm

OBJECTIVES: The efficacy of tocilizumab (TCZ), an anti-interleukin-6 receptor antibody, has not previously been evaluated in a population consisting exclusively of patients with early rheumatoid arthritis (RA).

METHODS: In a double-blind randomised controlled trial (FUNCTION), 1162 methotrexate (MTX)-naive patients with early progressive RA were randomly assigned (1:1:1:1) to one of four treatment groups: 4 mg/kg TCZ+MTX, 8 mg/kg TCZ+MTX, 8 mg/kg TCZ+placebo and placebo+MTX (comparator group). The primary outcome was remission according to Disease Activity Score using 28 joints (DAS28-erythrocyte sedimentation rate (ESR) < 2.6) at week 24. Radiographic and physical function outcomes were also evaluated. We report results through week 52.

RESULTS: The intent-to-treat population included 1157 patients. Significantly more patients receiving 8 mg/kg TCZ+MTX and 8 mg/kg TCZ+placebo than receiving placebo+MTX achieved DAS28-ESR remission at week 24 (45% and 39% vs 15%; p < 0.0001). The 8 mg/kg TCZ+MTX group also achieved significantly greater improvement in radiographic disease progression and physical function at week 52 than did patients treated with placebo+MTX (mean change from baseline in van der Heijde-modified total Sharp score, 0.08 vs 1.14 (p=0.0001); mean reduction in Health Assessment Disability Index, -0.81 vs -0.64 (p=0.0024)). In addition, the 8 mg/kg TCZ+placebo and 4 mg/kg TCZ+MTX groups demonstrated clinical efficacy that was at least as effective as MTX for these key secondary endpoints. Serious adverse events were similar among treatment groups. Adverse events resulting in premature withdrawal occurred in 20% of patients in the 8 mg/kg TCZ+MTX group.

CONCLUSIONS: TCZ is effective in combination with MTX and as monotherapy for the treatment of patients with early RA.

TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, number NCT01007435.

Animal Models for Alopecia Areata: What and Where

Fri, 02/26/2016 - 2:03pm

Disease is not limited to humans. Rather, humans are but another mammal in a continuum, and as such, often share similar if not identical diseases with other mammalian species. Alopecia areata (AA) is such a disease. Natural disease occurs in humans, nonhuman primates, many domestic animals, and laboratory rodents. However, to be useful as models of human disease, affected animals need to be readily available to the research community, closely resemble the human disease, be easy to work with, and provide reproducible data. To date, the laboratory mouse (most if not all of the C3H substrains) and the Dundee experimental bald rat fit these criteria. Manipulations using full-thickness skin grafts or specific immune cell transfers have improved the models. New mouse models that carry a variety of genetic-based immunodeficiencies can now be used to recapitulate the human immune system and allow for human full-thickness skin grafts onto mice to investigate human-specific mechanistic and therapeutic questions. These models are summarized here including where they can currently be obtained from public access repositories.

Frequent Emergency Department Visits and Hospitalizations Among Homeless People With Medicaid: Implications for Medicaid Expansion

Fri, 02/26/2016 - 2:03pm

OBJECTIVES: We examined factors associated with frequent hospitalizations and emergency department (ED) visits among Medicaid members who were homeless.

METHODS: We included 6494 Massachusetts Medicaid members who received services from a health care for the homeless program in 2010. We used negative binomial regression to examine variables associated with frequent utilization.

RESULTS: Approximately one third of the study population had at least 1 hospitalization and two thirds had 1 or more ED visits. More than 70% of hospitalizations and ED visits were incurred by only 12% and 21% of these members, respectively. Homeless individuals with co-occurring mental illness and substance use disorders were at greatest risk for frequent hospitalizations and ED visits (e.g., incidence rate ratios [IRRs] = 2.9-13.8 for hospitalizations). Individuals living on the streets also had significantly higher utilization (IRR = 1.5).

CONCLUSIONS: Despite having insurance coverage, homeless Medicaid members experienced frequent hospitalizations and ED visits. States could consider provisions under the Patient Protection and Affordable Care Act (e.g., Medicaid expansion and Health Homes) jointly with housing programs to meet the needs of homeless individuals, which may improve the quality and cost effectiveness of care.

Evaluating the QUIT-PRIMO clinical practice ePortal to increase smoker engagement with online cessation interventions: a national hybrid type 2 implementation study

Fri, 02/26/2016 - 2:03pm

BACKGROUND: Effective web-assisted tobacco interventions (WATIs) have been underutilized by smokers; moreover, despite practice guideline recommendations, clinical teams do not routinely refer smokers to WATIs. Our goal was to test a clinical practice innovation, an ePortal designed to change practice and patient behavior. Our hypotheses were that the integrated system would result in increased smoker referrals, with an automated follow-up system resulting in more smoker registrations and finally augmentations of the WATI would result in more smokers quitting at 6 months.

METHODS: Practice ePortal Implementation Trial: Practices (n = 174) were randomized to an online practice ePortal with an "e-referral tool" to the WATI (e-referred smokers received automated email reminders from the practice) and with practice feedback reports with patient tracking and practice-to-patient secure messaging versus comparison (a paper "referral prescription"). Implementation success was measured by the number of smokers referred and smokers registering. Clinical Effectiveness Trial: To estimate the effectiveness of the WATI components on 6-month smoking cessation, registered smokers were randomized into three groups: a state-of-the-art tailored WATI control [control], the WATI enhanced with proactive, pushed tailored email motivational messaging (messaging), and the WATI with messaging further enhanced with personal secure messaging with a tobacco treatment specialist and an online support group (personalized).

RESULTS: Practice ePortal Trial results: A total of 4789 smokers were referred. The mean smokers referred per practice was not statistically different by group (ePortal 24.89 (SD 22.29) versus comparison 30.15 (SD 25.45), p = 0.15). The e-referral portal implementation program resulted in nearly triple the rate of smoker registration (31 % of all smokers referred registered online) versus comparison (11 %, p < 0.001). Clinical Effectiveness Trial results: Active smokers randomized to the personalized group had a 6-month cessation rate of 25.2 %, compared with the messaging group (26.7 %) and the control (17 %). Next, when using an inverse probability weighted selection model to account for attrition, those randomized to the two groups that received motivational messaging (messaging or personalized) were more likely to quit than those in the control (p = 0.04).

CONCLUSIONS: Among all smokers referred, the e-referral resulted in nearly threefold greater registrants (31 %) than paper (11 %). The practice ePortal smokers received multiple reminders (increasing registration opportunities), and the practices could track patient progress. The result was more smokers registering and, thus, more cessation opportunities. Combining the proactive referral and the WATI resulted in higher rates of smoking cessation.

TRIAL REGISTRATION: Web-delivered Provider Intervention for Tobacco Control (QUIT-PRIMO) - a randomized controlled trial: NCT00797628 .

Decade-Long Trends in 30-Day Rehospitalization Rates After Acute Myocardial Infarction

Fri, 02/26/2016 - 2:02pm

BACKGROUND: There are limited data available describing relatively contemporary trends in 30-day rehospitalizations among patients who survive hospitalization after an acute myocardial infarction (AMI) in the community setting. We examined decade-long (2001-2011) trends in, and factors associated with, 30-day rehospitalizations in patients discharged from 3 central Massachusetts hospitals after AMI.

METHODS AND RESULTS: Residents of the Worcester, MA, metropolitan area discharged after AMI from 3 central Massachusetts hospitals on a biennial basis between 2001 and 2011 comprised the study population (N=4810). Logistic regression analyses were used to examine the association between selected factors and 30-day rehospitalizations. The average age of this population was 69 years, 42% were women, and 92% were white. During the years under study, 18.5% of patients were rehospitalized within 30 days after hospital discharge. Crude 30-day rehospitalization rates decreased from 20.5% in 2001-2003 to 15.8% in 2009-2011. After adjusting for several patient characteristics, there was a reduced odds of being rehospitalized in 2009-2011 (odds ratio 0.74, 95% CI 0.61-0.91) compared with 2001-2003; this trend was slightly attenuated after further adjustment for hospital treatment practices. Female sex, having previously diagnosed heart failure and chronic kidney disease, and the development of in-hospital cardiogenic shock and heart failure were associated with an increased odds of being rehospitalized.

CONCLUSIONS: While the likelihood of subsequent short-term rehospitalizations remained frequent, we observed an encouraging decline during the most recent years under study. Several high-risk groups were identified for purposes of heightened surveillance and intervention efforts to reduce the likelihood of being readmitted.

Positioning of AMPA Receptor-Containing Endosomes Regulates Synapse Architecture

Fri, 02/26/2016 - 2:02pm

Lateral diffusion in the membrane and endosomal trafficking both contribute to the addition and removal of AMPA receptors (AMPARs) at postsynaptic sites. However, the spatial coordination between these mechanisms has remained unclear, because little is known about the dynamics of AMPAR-containing endosomes. In addition, how the positioning of AMPAR-containing endosomes affects synapse organization and functioning has never been directly explored. Here, we used live-cell imaging in hippocampal neuron cultures to show that intracellular AMPARs are transported in Rab11-positive recycling endosomes, which frequently enter dendritic spines and depend on the microtubule and actin cytoskeleton. By using chemically induced dimerization systems to recruit kinesin (KIF1C) or myosin (MyosinV/VI) motors to Rab11-positive recycling endosomes, we controlled their trafficking and found that induced removal of recycling endosomes from spines decreases surface AMPAR expression and PSD-95 clusters at synapses. Our data suggest a mechanistic link between endosome positioning and postsynaptic structure and composition.

Cotton rat immune responses to virus-like particles containing the pre-fusion form of respiratory syncytial virus fusion protein

Fri, 02/26/2016 - 2:02pm

BACKGROUND: Virus-like particles (VLPs) based on Newcastle disease virus (NDV) core proteins, M and NP, and containing two chimera proteins, F/F and H/G, composed of the respiratory syncytial virus (RSV) fusion protein (F) and glycoprotein (G) ectodomains fused to the transmembrane and cytoplasmic domains of the NDV F and HN proteins, respectively, stimulate durable, protective anti-RSV neutralizing antibodies in mice. Furthermore, immunization of mice with a VLP containing a F/F chimera protein with modifications previously reported to stabilize the pre-fusion form of the RSV F protein resulted in significantly improved neutralizing antibody titers over VLPs containing the wild type F protein. The goal of this study was to determine if VLPs containing the pre-fusion form of the RSV F protein stimulated protective immune responses in cotton rats, a more RSV permissive animal model than mice.

METHODS: Cotton rats were immunized intramuscularly with VLPs containing stabilized pre-fusion F/F chimera protein as well as the H/G chimera protein. The anti-RSV F and RSV G antibody responses were determined by ELISA. Neutralizing antibody titers in sera of immunized animals were determined in plaque reduction assays. Protection of the animals from RSV challenge was assessed. The safety of the VLP vaccine was determined by monitoring lung pathology upon RSV challenge of immunized animals.

RESULTS: The Pre-F/F VLP induced neutralizing titers that were well above minimum levels previously proposed to be required for a successful vaccine and titers significantly higher than those stimulated by RSV infection. In addition, Pre-F/F VLP immunization stimulated higher IgG titers to the soluble pre-fusion F protein than RSV infection. Cotton rats immunized with Pre-F/F VLPs were protected from RSV challenge, and, importantly, the VLP immunization did not result in enhanced respiratory disease upon RSV challenge.

CONCLUSIONS: VLPs containing the pre-fusion RSV F protein have characteristics required for a safe, effective RSV vaccine.

Health evaluation and referral assistant: a randomized controlled trial to improve smoking cessation among emergency department patients

Fri, 02/26/2016 - 2:02pm

BACKGROUND: Computer technologies hold promise for implementing tobacco screening, brief intervention, and referral to treatment (SBIRT). This study aims to evaluate a computerized tobacco SBIRT system called the Health Evaluation and Referral Assistant (HERA).

METHODS: Smokers (n = 421) presenting to an emergency department were randomly assigned to the HERA or a minimal-treatment Control and were followed for 3 months. Analyses compared smoking cessation treatment provider contact, treatment initiation, treatment completion, and smoking behavior across condition using univariable comparisons, generalized estimating equations (GEE), and post hoc Chi square analyses.

RESULTS: HERA participants were more likely to initiate contact with a treatment provider but did not differ on treatment initiation, quit attempts, or sustained abstinence. Subanalyses revealed HERA participants who accepted a faxed referral were more likely to initiate treatment but were not more likely to stop smoking.

CONCLUSIONS: The HERA promoted initial contact with a smoking cessation provider and the faxed referral further promoted treatment initiation, but it did not lead to improved abstinence.

TRIAL REGISTRATION: ClinicalTrials.gov number NCT01153373.

NEMO Prevents Steatohepatitis and Hepatocellular Carcinoma by Inhibiting RIPK1 Kinase Activity-Mediated Hepatocyte Apoptosis

Fri, 02/26/2016 - 2:01pm

IkappaB kinase/necrosis factor kappaB (IKK/NF-kappaB) signaling exhibits important yet opposing functions in hepatocarcinogenesis. Mice lacking NEMO in liver parenchymal cells (LPC) spontaneously develop steatohepatitis and hepatocellular carcinoma (HCC) suggesting that NF-kappaB prevents liver disease and cancer. Here, we show that complete NF-kappaB inhibition by combined LPC-specific ablation of RelA, c-Rel, and RelB did not phenocopy NEMO deficiency, but constitutively active IKK2-mediated NF-kappaB activation prevented hepatocellular damage and HCC in NEMO(LPC-KO) mice. Knock-in expression of kinase inactive receptor-interacting protein kinase 1 (RIPK1) prevented hepatocyte apoptosis and HCC, while RIPK1 ablation induced TNFR1-associated death domain protein (TRADD)-dependent hepatocyte apoptosis and liver tumors in NEMO(LPC-KO) mice, revealing distinct kinase-dependent and scaffolding functions of RIPK1. Collectively, these results show that NEMO prevents hepatocarcinogenesis by inhibiting RIPK1 kinase activity-driven hepatocyte apoptosis through NF-kappaB-dependent and -independent functions.

A Small Molecule Inhibitor of ITK and RLK Impairs Th1 Differentiation and Prevents Colitis Disease Progression

Fri, 02/26/2016 - 2:01pm

In T cells, the Tec kinases IL-2-inducible T cell kinase (ITK) and resting lymphocyte kinase (RLK) are activated by TCR stimulation and are required for optimal downstream signaling. Studies of CD4(+) T cells from Itk(-/-) and Itk(-/-)Rlk(-/-) mice have indicated differential roles of ITK and RLK in Th1, Th2, and Th17 differentiation and cytokine production. However, these findings are confounded by the complex T cell developmental defects in these mice. In this study, we examine the consequences of ITK and RLK inhibition using a highly selective and potent small molecule covalent inhibitor PRN694. In vitro Th polarization experiments indicate that PRN694 is a potent inhibitor of Th1 and Th17 differentiation and cytokine production. Using a T cell adoptive transfer model of colitis, we find that in vivo administration of PRN694 markedly reduces disease progression, T cell infiltration into the intestinal lamina propria, and IFN-gamma production by colitogenic CD4(+) T cells. Consistent with these findings, Th1 and Th17 cells differentiated in the presence of PRN694 show reduced P-selectin binding and impaired migration to CXCL11 and CCL20, respectively. Taken together, these data indicate that ITK plus RLK inhibition may have therapeutic potential in Th1-mediated inflammatory diseases.

Recombination elevates the effective evolutionary rate and facilitates the establishment of HIV-1 infection in infants after mother-to-child transmission

Fri, 02/26/2016 - 2:01pm

BACKGROUND: Previous studies have demonstrated that single HIV-1 genotypes are commonly transmitted from mother to child, but such analyses primarily used single samples from mother and child. It is possible that in a single sample, obtained early after infection, only the most replication competent virus is detected even when other forms may have been transmitted. Such forms may have advantages later in infection, and may thus be detected in follow-up samples. Because HIV-1 frequently recombines, phylogenetic analyses that ignore recombination may miss transmission of multiple forms if they recombine after transmission. Moreover, recombination may facilitate adaptation, thus providing an advantage in establishing infection. The effect of recombination on viral evolution in HIV-1 infected children has not been well defined.

RESULTS: We analyzed full-length env sequences after single genome amplification from the plasma of four subtype B HIV-1 infected women (11-67 env clones from 1 time point within a month prior to delivery) and their non-breastfed, intrapartum-infected children (3-6 longitudinal time points per child starting at the time of HIV-1 diagnosis). To address the potential beneficial or detrimental effects of recombination, we used a recently developed hierarchical recombination detection method based on the pairwise homoplasy index (PHI)-test. Recombination was observed in 9-67% of the maternal sequences and in 25-60% of the child sequences. In the child, recombination only occurred between variants that had evolved after transmission; taking recombination into account, we identified transmission of only 1 or 2 phylogenetic lineages from mother to child. Effective HIV-1 evolutionary rates of HIV-1 were initially high in the child and slowed over time (after 1000 days). Recombination was associated with elevated evolutionary rates.

CONCLUSIONS: Our results confirm that 1-2 variants are typically transmitted from mothers to their newborns. They also demonstrate that early abundant recombination elevates the effective evolutionary rate, suggesting that recombination increases the rate of adaptation in HIV-1 evolution.

DNA-Containing Immunocomplexes Promote Inflammasome Assembly and Release of Pyrogenic Cytokines by CD14+ CD16+ CD64high CD32low Inflammatory Monocytes from Malaria Patients

Fri, 02/26/2016 - 2:00pm

High levels of circulating immunocomplexes (ICs) are found in patients with either infectious or sterile inflammation. We report that patients with either Plasmodium falciparum or Plasmodium vivax malaria have increased levels of circulating anti-DNA antibodies and ICs containing parasite DNA. Upon stimulation with malaria-induced ICs, monocytes express an NF-kappaB transcriptional signature. The main source of IC-induced proinflammatory cytokines (i.e., tumor necrosis factor alpha [TNF-alpha] and interleukin-1beta [IL-1beta])in peripheral blood mononuclear cells from acute malaria patients was found to be a CD14(+) CD16 (FcgammaRIIIA)(+) CD64 (FcgammaRI)(high) CD32 (FcgammaRIIB)(low) monocyte subset. Monocytes from convalescent patients were predominantly of the classical phenotype (CD14(+) CD16(-)) that produces high levels of IL-10 and lower levels of TNF-alpha and IL-1beta in response to ICs. Finally, we report a novel role for the proinflammatory activity of ICs by demonstrating their ability to induce inflammasome assembly and caspase-1 activation in human monocytes. These findings illuminate our understanding of the pathogenic role of ICs and monocyte subsets and may be relevant for future development of immunity-based interventions with broad applications to systemic inflammatory diseases.

IMPORTANCE: Every year, there are approximately 200 million cases of Plasmodium falciparum and P. vivax malaria, resulting in nearly 1 million deaths, most of which are children. Decades of research on malaria pathogenesis have established that the clinical manifestations are often a consequence of the systemic inflammation elicited by the parasite. Recent studies indicate that parasite DNA is a main proinflammatory component during infection with different Plasmodium species. This finding resembles the mechanism of disease in systemic lupus erythematosus, where host DNA plays a central role in stimulating an inflammatory process and self-damaging reactions. In this study, we disclose the mechanism by which ICs containing Plasmodium DNA activate innate immune cells and consequently stimulate systemic inflammation during acute episodes of malaria. Our results further suggest that Toll-like receptors and inflammasomes have a central role in malaria pathogenesis and provide new insights toward developing novel therapeutic interventions for this devastating disease.

A Higher Activation Threshold of Memory CD8+ T Cells Has a Fitness Cost That Is Modified by TCR Affinity during Tuberculosis

Wed, 02/24/2016 - 4:13pm

T cell vaccines against Mycobacterium tuberculosis (Mtb) and other pathogens are based on the principle that memory T cells rapidly generate effector responses upon challenge, leading to pathogen clearance. Despite eliciting a robust memory CD8+ T cell response to the immunodominant Mtb antigen TB10.4 (EsxH), we find the increased frequency of TB10.4-specific CD8+ T cells conferred by vaccination to be short-lived after Mtb challenge. To compare memory and naïve CD8+ T cell function during their response to Mtb, we track their expansions using TB10.4-specific retrogenic CD8+ T cells. We find that the primary (naïve) response outnumbers the secondary (memory) response during Mtb challenge, an effect moderated by increased TCR affinity. To determine whether the expansion of polyclonal memory T cells is restrained following Mtb challenge, we used TCRβ deep sequencing to track TB10.4-specific CD8+ T cells after vaccination and subsequent challenge in intact mice. Successful memory T cells, defined by their clonal expansion after Mtb challenge, express similar CDR3β sequences suggesting TCR selection by antigen. Thus, both TCR-dependent and -independent factors affect the fitness of memory CD8+ responses. The impaired expansion of the majority of memory T cell clonotypes may explain why some TB vaccines have not provided better protection.

Skeletal Characterization of Smurf2-Deficient Mice and In Vitro Analysis of Smurf2-Deficient Chondrocytes

Wed, 02/24/2016 - 2:49pm

Overexpression of Smad ubiquitin regulatory factor 2 (Smurf2) in chondrocytes was reported to cause spontaneous osteoarthritis (OA) in mice. However, it is unclear whether Smurf2 is involved in bone and cartilage homeostasis and if it is required for OA pathogenesis. Here we characterized age-related changes in the bone and articular cartilage of Smurf2-deficient (MT) mice by microCT and histology, and examined whether reduced Smurf2 expression affected the severity of OA upon surgical destabilization of the medial meniscus (DMM). Using immature articular chondrocytes (iMAC) from MT and wild-type (WT) mice, we also examined how Smurf2 deficiency affects chondrogenic and catabolic gene expressions and Smurf2 and Smurf1 proteins upon TGF-β3 or IL-1β treatment in culture. We found no differences in cortical, subchondral and trabecular bone between WT and MT in young (4 months) and old mice (16-24 months). The articular cartilage and age-related alterations between WT and MT were also similar. However, 2 months following DMM, young MT showed milder OA compared to WT (~70% vs ~30% normal or exhibiting only mild OA cartilage phenotype). The majority of the older WT and MT mice developed moderate/severe OA 2 months after DMM, but a higher subset of aged MT cartilage (27% vs. 9% WT) remained largely normal. Chondrogenic gene expression (Sox9, Col2, Acan) trended higher in MT iMACs than WT with/without TGF-β3 treatment. IL-1β treatment suppressed chondrgenic gene expression, but Sox9 expression in MT remained significantly higher than WT. Smurf2 protein in WT iMACs increased upon TGF-β3 treatment and decreased upon IL-1β treatment in a dose-dependent manner. Smurf1 protein elevated more in MT than WT upon TGF-β3 treatment, suggesting a potential, but very mild compensatory effect. Overall, our data support a role of Smurf2 in regulating OA development but suggest that inhibiting Smurf2 alone may not be sufficient to prevent or consistently mitigate post-traumatic OA across a broad age range.

Elimination of waste: creation of a successful Lean colonoscopy program at an academic medical center

Mon, 02/22/2016 - 4:47pm

OBJECTIVE: Lean processes involve streamlining methods and maximizing efficiency. Well established in the manufacturing industry, they are increasingly being applied to health care. The objective of this study was to determine feasibility and effectiveness of applying Lean principles to an academic medical center colonoscopy unit.

METHODS: Lean process improvement involved training endoscopy personnel, observing patients, mapping the value stream, analyzing patient flow, designing and implementing new processes, and finally re-observing the process. Our primary endpoint was total colonoscopy time (minutes from check-in to discharge) with secondary endpoints of individual segment times and unit colonoscopy capacity.

RESULTS: A total of 217 patients were included (November 2013-May 2014), with 107 pre-Lean and 110 post-Lean intervention. Pre-Lean total colonoscopy time was 134 min. After implementation of the Lean process, mean colonoscopy time decreased by 10 % to 121 min (p = 0.01). The three steps of the process affected by the Lean intervention (time to achieve adequate sedation, time to recovery, and time to discharge) decreased from 3.7 to 2.4 min (p < 0.01), 4.0 to 3.4 min (p = 0.09), and 41.2 to 35.4 min (p = 0.05), respectively. Overall, unit capacity of colonoscopies increased from 39.6 per day to 43.6. Post-Lean patient satisfaction surveys demonstrated an average score of 4.5/5.0 (n = 73) regarding waiting time, 4.9/5.0 (n = 60) regarding how favorably this experienced compared to prior colonoscopy experiences, and 4.9/5.0 (n = 74) regarding professionalism of staff. One hundred percentage of respondents (n = 69) stated they would recommend our institution to a friend for colonoscopy.

DISCUSSION: With no additional utilization of resources, a single Lean process improvement cycle increased productivity and capacity of our colonoscopy unit. We expect this to result in increased patient access and revenue while maintaining patient satisfaction. We believe these results are widely generalizable to other colonoscopy units as well as other process-based interventions in health care.

Mount Auburn Cemetery and its importance to the history of anesthesia

Mon, 02/22/2016 - 4:40pm

Boston, Massachusetts, is home to many sites related to the first public demonstration of ether, including the Ether Dome, the Ether Monument, and several homes in which William T. G. Morton lived. Notably, many of the participants in Morton’s successful demonstration of ether are buried in nearby Mount Auburn Cemetery in Cambridge, Massachusetts. Here we explore how changing burial customs in early 19th-century America brought so many of these individuals to rest in one location. We explain how Mount Auburn Cemetery was established, the difficulties it faced, how it evolved, and the role it plays today. Moreover, we describe some of its remarkable features and explore some unusual structures located within this institution so very closely associated with the history of anesthesia.