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1.
Exp Mol Med ; 56(1): 59-65, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38172598

ABSTRACT

The cell cycle apoptosis regulator (CCAR) family of proteins consists of two proteins, CCAR1 and CCAR2, that play a variety of roles in cellular physiology and pathology. These multidomain proteins are able to perform multiple interactions and functions, playing roles in processes such as stress responses, metabolism, and the DNA damage response. The evolutionary conservation of CCAR family proteins allows their study in model organisms such as Caenorhabditis elegans, where a role for CCAR in aging was revealed. This review particularly highlights the multifaceted roles of CCAR family proteins and their implications in the DNA damage response and in cancer biology.


Subject(s)
Caenorhabditis elegans , Neoplasms , Animals , Humans , Caenorhabditis elegans/genetics , Apoptosis , DNA Repair , Neoplasms/genetics , DNA Damage , Cell Cycle Proteins/metabolism , Apoptosis Regulatory Proteins/genetics , Adaptor Proteins, Signal Transducing/metabolism
2.
Philos Trans R Soc Lond B Biol Sci ; 378(1873): 20220012, 2023 03 27.
Article in English | MEDLINE | ID: mdl-36744561

ABSTRACT

Genetic resistance forms the foundation of infectious disease management in crops. However, rapid pathogen evolution is causing the breakdown of resistance and threatening disease control. Recent research efforts have identified strategies for resistance gene deployment that aim to disrupt pathogen adaptation and prevent breakdown. To date, there has been limited practical uptake of such strategies. In this paper, we focus on the socio-economic challenges associated with translating applied evolutionary research into scientifically informed management strategies to control pathogen adaptation. We develop a conceptual framework for the economic valuation of resistance and demonstrate that in addition to various direct benefits, resistance delivers considerable indirect and non-market value to farmers and society. Incentives for stakeholders to engage in stewardship strategies are complicated by the uncertain timeframes associated with evolutionary processes, difficulties in assigning ownership rights to genetic resources and lack of governance. These interacting biological, socio-economic and institutional complexities suggest that resistance breakdown should be viewed as a wicked problem, with often conflicting imperatives among stakeholders and no simple cause or solution. Promoting the uptake of scientific research outcomes that address complex issues in sustainable crop disease management will require a mix of education, incentives, legislation and social change. This article is part of the theme issue 'Infectious disease ecology and evolution in a changing world'.


Subject(s)
Agriculture , Crops, Agricultural , Crops, Agricultural/genetics , Socioeconomic Factors
3.
Platelets ; 33(5): 655-665, 2022 Jul 04.
Article in English | MEDLINE | ID: mdl-34986759

ABSTRACT

Burn injuries are common and often life-threatening trauma. With this trauma comes an interruption of normal hemostasis, with distinct impacts on platelets. Our interest in the relationships between burn injury and platelet function stems from two key perspectives: platelet function is a vital component of acute responses to injury, and furthermore the incidence of cardiovascular disease (CVD) is higher in burn survivors compared to the general population. This review explores the impact of burn injury on coagulation, platelet function, and the participation of platelets in immunopathology. Potential avenues of further research are explored, and consideration is given to what therapies may be appropriate for mediating post-burn thrombopathology.


Subject(s)
Blood Platelets , Cardiovascular Diseases , Blood Coagulation , Blood Platelets/physiology , Hemostasis , Humans , Platelet Function Tests
4.
J Bone Joint Surg Am ; 103(11): 977-983, 2021 06 02.
Article in English | MEDLINE | ID: mdl-33764925

ABSTRACT

BACKGROUND: The recent consensus definition for the diagnosis of fracture-related infection (FRI) includes the identification of indistinguishable microorganisms in at least 2 surgical deep-tissue specimens as a confirmatory criterion. However, this cut-off, and the total number of specimens from a patient with suspected FRI that should be sent for microbiological testing, have not been validated. We endeavored to estimate the accuracy of different numbers of specimens and diagnostic cut-offs for microbiological testing of deep-tissue specimens in patients undergoing surgical treatment for possible FRI. METHODS: A total of 513 surgical procedures in 385 patients with suspected FRI were included. A minimum of 2 surgical deep-tissue specimens were submitted for microbiological testing; 5 or more specimens were analyzed in 345 procedures (67%). FRI was defined by the presence of any confirmatory criteria other than microbiology. Resampling was utilized to model the sensitivity and specificity of diagnostic cut-offs for the number of surgical specimens yielding indistinguishable microorganisms and for the total number of specimens. The likelihood of detecting all clinically relevant microorganisms was also assessed. RESULTS: A diagnostic cut-off of at least 2 of 5 specimens with indistinguishable microorganisms identified by culture was 68% sensitive (95% confidence interval [CI], 62% to 74%) and 87% specific (95% CI, 81% to 94%) for the diagnosis of FRI. Two out of 3 specimens were 60% sensitive (95% CI, 55% to 66%) and 92% specific (95% CI, 88% to 96%). Submitting only 3 deep-tissue specimens risked missing clinically relevant microorganisms in at least 1 in 10 cases. CONCLUSIONS: The present study was the first to validate microbiological criteria for the diagnosis of FRI, supporting the current confirmatory diagnostic criteria for FRI. Analysis of at least 5 deep-tissue specimens in patients with possible FRI is recommended. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.


Subject(s)
Fracture Fixation/adverse effects , Fractures, Bone/surgery , Surgical Wound Infection/microbiology , Adolescent , Adult , Aged , Aged, 80 and over , Consensus , Evidence-Based Medicine , Female , Humans , Male , Middle Aged , Sensitivity and Specificity , Surgical Wound Infection/diagnosis , Young Adult
5.
Clin Infect Dis ; 73(2): 183-191, 2021 07 15.
Article in English | MEDLINE | ID: mdl-32277809

ABSTRACT

BACKGROUND: We evaluated the efficacy, pharmacokinetics (PK), and safety of clofazimine (CFZ) in patients living with human immunodeficiency virus (HIV) with cryptosporidiosis. METHODS: We performed a randomized, double-blind, placebo-controlled study. Primary outcomes in part A were reduction in Cryptosporidium shedding, safety, and PK. Primary analysis was according to protocol (ATP). Part B of the study compared CFZ PK in matched individuals living with HIV without cryptosporidiosis. RESULTS: Twenty part A and 10 part B participants completed the study ATP. Almost all part A participants had high viral loads and low CD4 counts, consistent with failure of antiretroviral (ARV) therapy. At study entry, the part A CFZ group had higher Cryptosporidium shedding, total stool weight, and more diarrheal episodes compared with the placebo group. Over the inpatient period, compared with those who received placebo, the CFZ group Cryptosporidium shedding increased by 2.17 log2 Cryptosporidium per gram stool (95% upper confidence limit, 3.82), total stool weight decreased by 45.3 g (P = .37), and number of diarrheal episodes increased by 2.32 (P = .87). The most frequent solicited adverse effects were diarrhea, abdominal pain, and malaise. One placebo and 3 CFZ participants died during the study. Plasma levels of CFZ in participants with cryptosporidiosis were 2-fold lower than in part B controls. CONCLUSIONS: Our findings do not support the efficacy of CFZ for the treatment of cryptosporidiosis in a severely immunocompromised HIV population. However, this trial demonstrates a pathway to assess the therapeutic potential of drugs for cryptosporidiosis treatment. Screening persons living with HIV for diarrhea, and especially Cryptosporidium infection, may identify those failing ARV therapy. CLINICAL TRIALS REGISTRATION: NCT03341767.


Subject(s)
Biomedical Research , Cryptosporidiosis , Cryptosporidium , HIV Infections , Adult , Clofazimine/therapeutic use , Cryptosporidiosis/complications , Cryptosporidiosis/drug therapy , Diarrhea , HIV , HIV Infections/complications , HIV Infections/drug therapy , Humans
6.
Eur J Clin Microbiol Infect Dis ; 40(2): 353-359, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32960364

ABSTRACT

Delayed initiation of effective antimicrobial therapy for sepsis is associated with increased mortality. Whilst automated blood culture machines operate continuously, this does not align with conventional staff working hours and so turn-around-times (TAT) for reporting gram stains to clinicians are 3-7 times longer for blood cultures that flag positive overnight. We retrospectively compared laboratory TATs and clinical outcomes for blood cultures from 183 patients that flagged positive overnight during a 4-month period before and after the implementation of an overnight laboratory service. Enterobacterales and urinary tract infections were the most frequent pathogens and clinical syndrome respectively, and the prevalence of multi-resistant organisms was 15%. Compared with the pre-implementation period, the post-implementation period was associated with shorter median time from blood culture positivity to gram stain (7.4 vs 1.2 h), first genus level identification (7.2 vs 5.8 h) and first antimicrobial susceptibility result (24.1 vs 7.9 h). Similarly, the median time from blood culture positivity to clinicians first being informed was significantly shorter (9.2 vs 1.3 h). After removal of likely contaminants, 78% of patients were on effective empiric antimicrobials and for patients on ineffective empiric antimicrobials, effective therapy was initiated a median of 3.2 h sooner during the post-implementation period, without impact on mortality. Implementation of an overnight laboratory service was associated with significantly faster TAT for reporting blood culture results and more prompt initiation of effective antimicrobials for patients receiving ineffective empiric therapy, improving attainment of sepsis management goals.


Subject(s)
Bacteremia , Bacteriological Techniques/methods , Blood Culture/methods , Laboratories, Hospital/organization & administration , Personnel Staffing and Scheduling , Point-of-Care Testing , Aged , Aged, 80 and over , Bacteremia/diagnosis , Bacteremia/microbiology , Female , Humans , Male , Middle Aged , Retrospective Studies , Time Factors
7.
Opt Express ; 27(11): 15318-15326, 2019 May 27.
Article in English | MEDLINE | ID: mdl-31163729

ABSTRACT

Beam steering is essential for a variety of optical applications such as communication, LIDAR, and imaging. Microelectromechanical system (MEMS) mirrors are an effective method of achieving modest speeds and angular range at low cost. Typically there are a number of tradeoffs considered when designing a tip-tilt mirror, such as tilt angle and speed. For example, many mirrors are designed to scan at their resonant frequency to achieve large angles. This is effective for a scanning mode; however, this makes the device slow and ineffective as a galvo (quasi-static). Here, we present a magnetic MEMS mirror with extreme quasi-static mechanical tilt angles of ±60° (±120° optical) about two rotation axes. This micromirror enables full hemispheric optical coverage without compromising speed; settling in 4.5 ms using advanced drive techniques. This mirror will enable new applications for MEMS micromirrors previously thought impossible due to their limited angular range and speed.

8.
Methods Mol Biol ; 1907: 145-157, 2019.
Article in English | MEDLINE | ID: mdl-30542998

ABSTRACT

Transposon mutagenesis has emerged as a powerful methodology for functionally annotating cancer genomes. Although in vivo transposon-mediated forward genetic screens have proven to be valuable for cancer gene identification, they are also time consuming and resource intensive. To facilitate the rapid and cost-effective identification of genes that regulate tumor-promoting pathways, we developed a complementary ex vivo transposon mutagenesis approach wherein human or mouse cells growing in culture are mutagenized and screened for the acquisition of specific phenotypes in vitro or in vivo, such as growth factor independence or tumor-forming ability. This approach allows discovery of both gain- and loss-of-function mutations in the same screen. Transposon insertions sites are recovered by high-throughput sequencing. We recently applied this system to comprehensively identify and validate genes that promote growth factor independence and transformation of murine Ba/F3 cells. Here we describe a method for performing ex vivo Sleeping Beauty-mediated mutagenesis screens in these cells, which may be adapted for the acquisition of many different phenotypes in distinct cell types.


Subject(s)
DNA Transposable Elements , Genetic Testing/methods , Mutagenesis , Neoplasm Proteins/genetics , Neoplasms/genetics , Genome, Human , Humans , Neoplasms/pathology
9.
Cell Rep ; 25(8): 2223-2233.e6, 2018 11 20.
Article in English | MEDLINE | ID: mdl-30463017

ABSTRACT

Pathways underlying metabolic reprogramming in cancer remain incompletely understood. We identify the transmembrane serine protease TMPRSS11B as a gene that promotes transformation of immortalized human bronchial epithelial cells (HBECs). TMPRSS11B is upregulated in human lung squamous cell carcinomas (LSCCs), and high expression is associated with poor survival of non-small cell lung cancer patients. TMPRSS11B inhibition in human LSCCs reduces transformation and tumor growth. Given that TMPRSS11B harbors an extracellular (EC) protease domain, we hypothesized that catalysis of a membrane-bound substrate modulates tumor progression. Interrogation of a set of soluble receptors revealed that TMPRSS11B promotes solubilization of Basigin, an obligate chaperone of the lactate monocarboxylate transporter MCT4. Basigin release mediated by TMPRSS11B enhances lactate export and glycolytic metabolism, thereby promoting tumorigenesis. These findings establish an oncogenic role for TMPRSS11B and provide support for the development of therapies that target this enzyme at the surface of cancer cells.


Subject(s)
Glycolysis , Lactic Acid/metabolism , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Membrane Proteins/metabolism , Serine Endopeptidases/metabolism , Basigin/metabolism , Biological Transport , Carcinogenesis/metabolism , Carcinogenesis/pathology , Cell Line, Tumor , Cell Membrane/metabolism , Cell Proliferation , Cell Transformation, Neoplastic/pathology , Humans , Monocarboxylic Acid Transporters/metabolism , Muscle Proteins/metabolism , Neoplasms, Squamous Cell/metabolism , Neoplasms, Squamous Cell/pathology , Protein Binding , Solubility
10.
Vet Comp Oncol ; 16(2): 188-193, 2018 Jun.
Article in English | MEDLINE | ID: mdl-28560846

ABSTRACT

Prognosis of feline gastrointestinal mast cell tumours (FGIMCT), based on limited available literature, is described as guarded to poor, which may influence treatment recommendations and patient outcome. The purpose of this study is to describe the clinical findings, treatment response, and outcome of FGIMCT. Medical records of 31 cats diagnosed with and treated for FGIMCT were retrospectively reviewed. Data collected included signalment, method of diagnosis, tumour location (including metastatic sites), treatment type, cause of death and survival time. Mean age was 12.9 y. Diagnosis was made via cytology (n = 15), histopathology (n = 13) or both (n = 3). Metastatic sites included abdominal lymph node (n = 10), abdominal viscera (n = 4) and both (n = 2). Therapeutic approaches included chemotherapy alone (n = 15), surgery and chemotherapy (n = 7), glucocorticoid only (n = 6) and surgery and glucocorticoid (n = 3). Lomustine (n = 15) and chlorambucil (n = 12) were the most commonly used chemotherapy drugs. Overall median survival time was 531 d (95% confidence interval 334, 982). Gastrointestinal location, diagnosis of additional cancers, and treatment type did not significantly affect survival time. Cause of death was tumour-related or unknown (n = 12) and unrelated (n = 8) in the 20 cats dead at the time of analysis. The prognosis for cats with FGIMCT may be better than previously reported, with 26% of cats deceased from an unrelated cause. Surgical and medical treatments (including prednisolone alone) were both associated with prolonged survival times. Treatment other than prednisolone may not be necessary in some cats. Continued research into prognostic factors and most effective treatment strategies are needed.


Subject(s)
Cat Diseases/pathology , Cat Diseases/therapy , Gastrointestinal Neoplasms/therapy , Gastrointestinal Neoplasms/veterinary , Mast-Cell Sarcoma/veterinary , Animals , Antineoplastic Agents/therapeutic use , Cats , Databases, Factual , Female , Gastrointestinal Neoplasms/pathology , Hospitals, Animal , Kaplan-Meier Estimate , Male , Mast Cells/drug effects , Mast Cells/pathology , Mast-Cell Sarcoma/pathology , Mast-Cell Sarcoma/therapy , Neoplasm Staging , Retrospective Studies , Schools, Veterinary , Survival , Treatment Outcome , United States
11.
J Small Anim Pract ; 59(6): 343-349, 2018 Jun.
Article in English | MEDLINE | ID: mdl-29134653

ABSTRACT

OBJECTIVES: To estimate prevalence of exposure to environmental tobacco smoke and other environmental toxins in dogs with primary lung tumours and to analyse association between exposure and lung tumour development. MATERIALS AND METHODS: In this case-control study, an owner survey was developed to collect data on patient characteristics, general health care and environmental exposures. Dogs diagnosed with primary lung carcinomas formed the Case group. Dogs diagnosed with mast cell tumours served as Control Group 1 and dogs diagnosed with neurologic disease served as Control Group 2. Associations between diagnosis of primary lung tumour and patient and environmental exposure variables were analysed using bivariate and multivariate statistical methods. RESULTS: A total of 1178 owner surveys were mailed and 470 surveys were returned and included in statistical analysis, including 135 Cases, 169 dogs in Control Group 1 and 166 dogs in Control Group 2. An association between exposure to second-hand smoke and prevalence of primary lung cancer was not identified in this study. CLINICAL SIGNIFICANCE: Second-hand smoke is associated with primary lung cancer in people but a definitive association has not been found in dogs. The results of this study suggest that tobacco smoke exposure may not be associated with primary lung cancer development in dogs but study limitations may have precluded detection of an association.


Subject(s)
Dog Diseases/epidemiology , Lung Neoplasms/veterinary , Tobacco Smoke Pollution/adverse effects , Air Pollution, Indoor/adverse effects , Animals , Case-Control Studies , Dogs , Environmental Exposure/adverse effects , Humans , Lung Neoplasms/epidemiology , Mastocytosis, Cutaneous/epidemiology , Mastocytosis, Cutaneous/veterinary , Nervous System Diseases/epidemiology , Nervous System Diseases/veterinary , Risk Factors , Surveys and Questionnaires
12.
Cancer Res ; 77(1): 187-197, 2017 01 01.
Article in English | MEDLINE | ID: mdl-27821484

ABSTRACT

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-associated deaths worldwide. Given the efficacy of membrane proteins as therapeutic targets in human malignancies, we examined cell-surface receptors that may act as drivers of lung tumorigenesis. Here, we report that the PROTOCADHERIN PCDH7 is overexpressed frequently in NSCLC tumors where this event is associated with poor clinical outcome. PCDH7 overexpression synergized with EGFR and KRAS to induce MAPK signaling and tumorigenesis. Conversely, PCDH7 depletion suppressed ERK activation, sensitized cells to MEK inhibitors, and reduced tumor growth. PCDH7 potentiated ERK signaling by facilitating interaction of protein phosphatase PP2A with its potent inhibitor, the SET oncoprotein. By establishing an oncogenic role for PCDH7 in lung tumorigenesis, our results provide a rationale to develop novel PCDH7 targeting therapies that act at the cell surface of NSCLC cells to compromise their growth. Cancer Res; 77(1); 187-97. ©2016 AACR.


Subject(s)
Cadherins/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Transformation, Neoplastic/metabolism , Lung Neoplasms/pathology , MAP Kinase Signaling System/physiology , Animals , Blotting, Western , Carcinoma, Non-Small-Cell Lung/metabolism , Cell Line, Tumor , Cell Transformation, Neoplastic/pathology , DNA-Binding Proteins , ErbB Receptors/metabolism , Heterografts , Histone Chaperones/metabolism , Humans , Immunoprecipitation , Lung Neoplasms/metabolism , Mice , Mice, Inbred NOD , Polymerase Chain Reaction , Proportional Hazards Models , Protein Phosphatase 2/metabolism , Proto-Oncogene Proteins p21(ras)/metabolism , Protocadherins , Signal Transduction/physiology , Survival Analysis , Tissue Array Analysis , Transcription Factors/metabolism
13.
J Aquat Anim Health ; 28(4): 235-239, 2016 12.
Article in English | MEDLINE | ID: mdl-28005491

ABSTRACT

The copepod Tegastes acroporanus is a notorious pest of captive corals in the genus Acropora. In recent years, infestations of T. acroporanus have become widespread among public aquaria and coral propagation facilities and have been largely controlled with the extra-label use of milbemycin oxime formulations (Carl 2008). Many of these drug formulations (which were intended for dogs) have been discontinued by their manufacturers in favor of multidrug products, many of which are unsuitable for corals, forcing experimentation with alternatives. This report provides the first data on populations of T. acroporanus treated with milbemycin oxime and documents the first known use of an otic solution, MilbeMite Otic (Novartis Animal Health U.S., Greensboro, North Carolina), against copepods on live corals. MilbeMite Otic was found to be soluble in seawater and successful at eradicating T. acroporanus in a large exhibit over the course of 6-h waterborne baths (n = 12) at 0.167 µg/L. The resident population of T. acroporanus was also quantified before each treatment to provide the first estimates of coral parasite burden in response to the application of a waterborne chemotherapeutic agent. Received November 19, 2015; accepted June 7, 2016 Published online October 24, 2016.


Subject(s)
Anthelmintics/pharmacology , Anthozoa/parasitology , Copepoda/drug effects , Macrolides/pharmacology , Animals , Host-Parasite Interactions/drug effects
14.
Cancer Res ; 76(4): 773-86, 2016 Feb 15.
Article in English | MEDLINE | ID: mdl-26676752

ABSTRACT

Aberrant signaling through cytokine receptors and their downstream signaling pathways is a major oncogenic mechanism underlying hematopoietic malignancies. To better understand how these pathways become pathologically activated and to potentially identify new drivers of hematopoietic cancers, we developed a high-throughput functional screening approach using ex vivo mutagenesis with the Sleeping Beauty transposon. We analyzed over 1,100 transposon-mutagenized pools of Ba/F3 cells, an IL3-dependent pro-B-cell line, which acquired cytokine independence and tumor-forming ability. Recurrent transposon insertions could be mapped to genes in the JAK/STAT and MAPK pathways, confirming the ability of this strategy to identify known oncogenic components of cytokine signaling pathways. In addition, recurrent insertions were identified in a large set of genes that have been found to be mutated in leukemia or associated with survival, but were not previously linked to the JAK/STAT or MAPK pathways nor shown to functionally contribute to leukemogenesis. Forced expression of these novel genes resulted in IL3-independent growth in vitro and tumorigenesis in vivo, validating this mutagenesis-based approach for identifying new genes that promote cytokine signaling and leukemogenesis. Therefore, our findings provide a broadly applicable approach for classifying functionally relevant genes in diverse malignancies and offer new insights into the impact of cytokine signaling on leukemia development.


Subject(s)
Carcinogenesis/genetics , Cell Transformation, Neoplastic/genetics , Leukemia/genetics , Animals , Humans , Leukemia/pathology , Mice , Mutagenesis , Signal Transduction
15.
J Viral Hepat ; 22(3): 281-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25174689

ABSTRACT

Accelerated intrahepatic hepatitis C virus (HCV) pathogenesis is likely the result of dysregulation within both the innate and adaptive immune compartments, but the exact contribution of peripheral blood and liver lymphocyte subsets remains unclear. Prolonged activation and expansion of immunoregulatory cells have been thought to play a role. We determined immune cell subset frequency in contemporaneous liver and peripheral blood samples from chronic HCV-infected and HIV/HCV-coinfected individuals. Peripheral blood mononuclear cells (PBMC) and biopsy-derived liver-infiltrating lymphocytes from 26 HIV/HCV-coinfected, 10 chronic HCV-infected and 10 HIV-infected individuals were assessed for various subsets of T and B lymphocytes, dendritic cell, natural killer (NK) cell and NK T-cell frequency by flow cytometry. CD8(+) T cells expressing the exhaustion marker PD-1 were increased in HCV-infected individuals compared with uninfected individuals (P = 0.02), and HIV coinfection enhanced this effect (P = 0.005). In the liver, regulatory CD4(+) CD25(+) Foxp3(+) T cells, as well as CD4(+) CD25(+) PD1(+) T cells, were more frequent in HIV/HCV-coinfected than in HCV-monoinfected samples (P < 0.001). HCV was associated with increased regulatory T cells, PD-1(+) T cells and decreased memory B cells, regardless of HIV infection (P ≤ 0.005 for all). Low CD8(+) expression was observed only in PD-1(+) CD8(+) T cells from HCV-infected individuals and healthy controls (P = 0.002) and was associated with enhanced expansion of exhausted CD8(+) T cells when exposed in vitro to PHA or CMV peptides. In conclusion, in HIV/HCV coinfection, ongoing HCV replication is associated with increased regulatory and exhausted T cells in the periphery and liver that may impact control of HCV. Simultaneous characterization of liver and peripheral blood highlights the disproportionate intrahepatic compartmentalization of immunoregulatory T cells, which may contribute to establishment of chronicity and hepatic fibrogenesis in HIV coinfection.


Subject(s)
Coinfection , HIV Infections/immunology , Hepatitis C/immunology , Adaptive Immunity , Adult , CD4 Lymphocyte Count , Female , Genotype , HIV Infections/virology , HIV-1/immunology , Hepacivirus/genetics , Hepacivirus/immunology , Hepatitis C/virology , Humans , Immunity, Innate , Immunophenotyping , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/metabolism , Liver/immunology , Liver/pathology , Liver/virology , Lymphocyte Count , Male , Middle Aged , Programmed Cell Death 1 Receptor/metabolism , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Viral Load
16.
Br J Anaesth ; 113(4): 708-16, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24852502

ABSTRACT

BACKGROUND: In clinical practice, global oxygen delivery (DO2) is often considered as a whole; however pathological and adaptive responses after a decrease in individual constituents of the DO2 equation (cardiac output, haemoglobin, oxyhaemoglobin saturation) are likely to be diverse. We hypothesized that an equivalent decrease in DO2 after reductions in each separate component of the equation would result in different haemodynamic, tissue oxygenation, and stress hormonal responses. METHODS: Anaesthetized, fluid-resuscitated male Wistar rats were subjected to circulatory, anaemic, or hypoxic hypoxia (by haemorrhage, isovolaemic haemodilution, and breathing a hypoxic gas mix, respectively), produced either rapidly over 5 min or graded over 30 min, to a targeted 50% decrease in global oxygen delivery. Sham-operated animals acted as controls. Measurements were made of haemodynamics, skeletal muscle tissue oxygen tension, blood gas analysis, and circulating stress hormone levels. RESULTS: Whereas haemorrhage generated the largest decrease in cardiac output, and the greatest stress hormone response, haemodilution had the most marked effect on arterial pressure. In contrast, rapid hypoxaemia produced a minor impact on global haemodynamics yet induced the greatest decrease in regional oxygenation. A greater degree of hyperlactataemia was observed with graded insults compared with those administered rapidly. CONCLUSIONS: Decreasing global oxygen delivery, achieved by targeted reductions in its separate components, induces varying circulatory, tissue oxygen tension, and stress hormone responses. We conclude that not all oxygen delivery is the same; this disparity should be emphasized in classical teaching and re-evaluated in patient management.


Subject(s)
Hemodynamics/physiology , Hormones/metabolism , Oxygen Consumption/physiology , Stress, Psychological/metabolism , Algorithms , Anesthesia, Inhalation , Anesthetics, Inhalation , Animals , Blood Gas Analysis , Blood Volume/physiology , Cardiac Output/physiology , Deuterium Oxide/metabolism , Hemodilution , Hemoglobins/metabolism , Hemorrhage/metabolism , Isoflurane , Male , Oxyhemoglobins/metabolism , Rats , Rats, Wistar , Urodynamics/physiology
17.
Scand J Med Sci Sports ; 24(1): e11-9, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23944355

ABSTRACT

The purpose of this study was to investigate the effect of accumulating 60 min of exercise on endothelial function and triacylglycerol concentrations following the ingestion of a high-fat breakfast and lunch in 14 adolescent boys (aged 12 to 14 years). Two, 2-day main trials (control and exercise) were completed in a counter-balanced, cross-over design. Participants were inactive on day 1 of the control trial but on day 1 of the exercise trial completed 6 × 10 min runs at 70% of peak oxygen uptake, spread over the day. On day 2, triacylglycerol concentrations and flow-mediated dilation (FMD) were measured prior to, and following, ingestion of the high-fat meals. In the control trial, FMD was reduced by 30% and 33% (P < 0.001) following the high-fat breakfast and lunch; following exercise these reductions were negated (main effect trial, P = 0.002, interaction effect trial × time, P < 0.001). The total and incremental areas under the triacylglycerol concentration vs time curve were reduced by 11% and 16% in the exercise trial; however, these differences were not significant (P > 0.05). These results support the concept of accumulating physical activity for health in adolescents as the accumulated exercise attenuated the decline in FMD seen following the consumption of high-fat meals.


Subject(s)
Brachial Artery/physiology , Diet, High-Fat , Endothelium, Vascular/physiology , Exercise/physiology , Postprandial Period/physiology , Triglycerides/blood , Vasodilation/physiology , Accelerometry , Adolescent , Area Under Curve , Brachial Artery/diagnostic imaging , Child , Cross-Over Studies , Dietary Fats/metabolism , Humans , Linear Models , Male , Ultrasonography
19.
Mol Endocrinol ; 27(10): 1724-42, 2013 Oct.
Article in English | MEDLINE | ID: mdl-24014650

ABSTRACT

The proinflammatory cytokines IL-1ß and IFN-γ decrease functional islet ß-cell mass in part through the increased expression of specific genes, such as inducible nitric oxide synthase (iNOS). Dysregulated iNOS protein accumulation leads to overproduction of nitric oxide, which induces DNA damage, impairs ß-cell function, and ultimately diminishes cellular viability. However, the transcriptional mechanisms underlying cytokine-mediated expression of the iNOS gene are not completely understood. Herein, we demonstrated that individual mutations within the proximal and distal nuclear factor-κB sites impaired cytokine-mediated transcriptional activation. Surprisingly, mutating IFN-γ-activated site (GAS) elements in the iNOS gene promoter, which are classically responsive to IFN-γ, modulated transcriptional sensitivity to IL-1ß. Transcriptional sensitivity to IL-1ß was increased by generation of a consensus GAS element and decreased correspondingly with 1 or 2 nucleotide divergences from the consensus sequence. The nuclear factor-κB subunits p65 and p50 bound to the κB response elements in an IL-1ß-dependent manner. IL-1ß also promoted binding of serine-phosphorylated signal transducer and activator of transcription-1 (STAT1) (Ser727) but not tyrosine-phosphorylated STAT1 (Tyr701) to GAS elements. However, phosphorylation at Tyr701 was required for IFN-γ to potentiate the IL-1ß response. Furthermore, coactivator p300 and coactivator arginine methyltransferase were recruited to the iNOS gene promoter with concomitant displacement of the coactivator CREB-binding protein in cells exposed to IL-1ß. Moreover, these coordinated changes in factor recruitment were associated with alterations in acetylation, methylation, and phosphorylation of histone proteins. We conclude that p65 and STAT1 cooperate to control iNOS gene transcription in response to proinflammatory cytokines by a coactivator exchange mechanism. This increase in transcription is also associated with signal-specific chromatin remodeling that leads to RNA polymerase II recruitment and phosphorylation.


Subject(s)
Interferon-gamma/metabolism , Interleukin-1beta/metabolism , Nitric Oxide Synthase Type II/genetics , Transcriptional Activation , Active Transport, Cell Nucleus , Animals , Cell Nucleus/metabolism , Chromatin Assembly and Disassembly , Enzyme Induction , I-kappa B Proteins/metabolism , Janus Kinase 1/metabolism , NF-KappaB Inhibitor alpha , Nitric Oxide Synthase Type II/metabolism , Phosphorylation , Protein Binding , Protein Processing, Post-Translational , Protein-Arginine N-Methyltransferases/metabolism , Rats , Rats, Wistar , Response Elements , STAT1 Transcription Factor/metabolism , Transcription Factor RelA/metabolism , p300-CBP Transcription Factors/metabolism
20.
HIV Clin Trials ; 14(4): 149-59, 2013.
Article in English | MEDLINE | ID: mdl-23924587

ABSTRACT

BACKGROUND: Coinfection with HIV and hepatitis B virus (HBV) substantially alters the course of HBV. Directly acting anti-HBV agents suppress HBV viral levels; however, the kinetics of HBV decline in mono- and coinfected persons have not been evaluated. We investigated the role of baseline CD4+ T-cell counts as a predictor of HBV response to adefovir (ADV) therapy in chronic HBV with and without HIV coinfection. METHODS: We conducted a double-blind, randomized, placebo-controlled study of HIV-infected (n = 12) and uninfected (n = 5) chronic HBV patients treated with ADV. Five HIV uninfected patients received ADV; the HIV+ patients received ADV or placebo for a total of 48 weeks. At the end of 48 weeks, all patients received open-label ADV for an additional 48 weeks. HBV, HIV viral loads, CD4+ T-cell counts, and safety labs were performed on days 0, 1, 3, 5, 7, 10, 14, and 28 and then every 4 weeks. RESULTS: Lower HBV slopes were observed among coinfected compared to monoinfected patients (P = .027 at 4 weeks, P = .019 at 24 weeks, and P = .045 at 48 weeks). Using a mixed model analysis, we found a significant difference between the slopes of the 2 groups at 48 weeks (P = .045). Baseline CD4+ T-cell count was the only independent predictor of HBV decline in all patients. CONCLUSION: HIV coinfection is associated with slower HBV response to ADV. Baseline CD4+ T-cell count and not IL28B genotype is an independent predictor of HBV decline in all patients, emphasizing the role of immune status on clearance of HBV.


Subject(s)
Adenine/analogs & derivatives , Antiviral Agents/therapeutic use , CD4 Lymphocyte Count , HIV Infections/virology , Hepatitis B/drug therapy , Lamivudine/therapeutic use , Organophosphonates/therapeutic use , Adenine/therapeutic use , Adolescent , Adult , Aged , Coinfection/drug therapy , Coinfection/virology , Double-Blind Method , Drug Resistance, Viral , Female , HIV Infections/immunology , Hepatitis B/immunology , Hepatitis B/virology , Humans , Kinetics , Male , Middle Aged
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