156 research outputs found

    Sertraline and Phenytoin Drug Interaction in a Geriatric Patient

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    This report presents the case of a 78-year-old man residing in a nursing home who presented with a 2-month history of increasing lethargy and confusion. These symptoms coincided with the initiation of sertraline in the patient. Among other medications, he was also taking phenytoin. The medical team concluded that the cause of the patient’s lethargy and confusion was a drug interaction between sertraline and phenytoin. Phenytoin was held, while the sertraline was slowly tapered to discontinuation. The patient’s symptoms resolved soon thereafter. Future research is needed to better guide clinicians in appropriate selection, dosing, and monitoring of selective serotonin reuptake inhibitors with concomitant phenytoin use.Key words: phenytoin, sertraline, SSRIs, drug interactio

    The coincidental evolution hypothesis: examining the factors that affect virulence in an opportunistic pathogen

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    The coincidental evolution hypothesis proposes that virulence in an opportunistic bacterial pathogen arises in response to selection from predators in the outside host environment. Opportunistic pathogens, unlike obligate pathogens, do not need a host for survival, and exist in multiple environments where they face selective pressure from eukaryotic predators. This results in a population of bacteria with the best defenses against predation—mechanisms which “coincidentally” cause harm during host infection. Few studies have examined the coincidental evolution hypothesis, and those that have present conflicting results. Here, we investigated the validity of the coincidental evolution hypothesis by subjecting the opportunistic pathogen Serratia marcescens to three different scenarios: (1) co-culture with the ciliate predator Tetrahymena thermophila, (2) growth in the absence of predators alone in media, and (3) growth within the guts of germ-free honey bees. We hypothesized that strains evolved in the presence of a predator would display increased virulence and strains evolved in the absence of predators or within a host would exhibit decreased virulence. Our study revealed that evolution in the presence of a predator resulted in increased virulence of S. marcescens. When compared to the media-evolved isolate, all predator-evolved lines exhibited increased pathogenicity in honey bees. However, when investigating how within-host evolution impacts virulence, we observed little to no change in virulence in host-evolved lines. We hypothesize that the lack of attenuated virulence in within-host-evolved strains is due to lack of selective pressure due to S. marcescens already being found at low levels in the bee gut. Overall, our findings indicate that predation plays a role in the evolution of virulence in opportunistic pathogens and thus support the coincidental evolution hypothesis. We were also able to identify mutations and genes potentially associated with virulence. This study sheds light of the factors that impact virulence and drive the evolution of opportunistic pathogens

    Galaxy Zoo: Passive Red Spirals

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    We study the spectroscopic properties and environments of red spiral galaxies found by the Galaxy Zoo project. By carefully selecting face-on, disk dominated spirals we construct a sample of truly passive disks (not dust reddened, nor dominated by old stellar populations in a bulge). As such, our red spirals represent an interesting set of possible transition objects between normal blue spirals and red early types. We use SDSS data to investigate the physical processes which could have turned these objects red without disturbing their morphology. Red spirals prefer intermediate density regimes, however there are no obvious correlations between red spiral properties and environment - environment alone is not sufficient to determine if a spiral will become red. Red spirals are a small fraction of spirals at low masses, but are a significant fraction at large stellar masses - massive galaxies are red independent of morphology. We confirm that red spirals have older stellar popns and less recent star formation than the main spiral population. While the presence of spiral arms suggests that major star formation cannot have ceased long ago, we show that these are not recent post-starbursts, so star formation must have ceased gradually. Intriguingly, red spirals are ~4 times more likely than normal spirals to host optically identified Seyfert or LINER, with most of the difference coming from LINERs. We find a curiously large bar fraction in the red spirals suggesting that the cessation of star formation and bar instabilities are strongly correlated. We conclude by discussing the possible origins. We suggest they may represent the very oldest spiral galaxies which have already used up their reserves of gas - probably aided by strangulation, and perhaps bar instabilities moving material around in the disk.Comment: MNRAS in press, 20 pages, 15 figures (v3

    Mitochondrial targeted catalase suppresses invasive breast cancer in mice

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    <p>Abstract</p> <p>Background</p> <p>Treatment of invasive breast cancer has an alarmingly high rate of failure because effective targets have not been identified. One potential target is mitochondrial generated reactive oxygen species (ROS) because ROS production has been associated with changes in substrate metabolism and lower concentration of anti-oxidant enzymes in tumor and stromal cells and increased metastatic potential.</p> <p>Methods</p> <p>Transgenic mice expressing a human catalase gene (mCAT) were crossed with MMTV-PyMT transgenic mice that develop metastatic breast cancer. All mice (33 mCAT positive and 23 mCAT negative) were terminated at 110 days of age, when tumors were well advanced. Tumors were histologically assessed for invasiveness, proliferation and metastatic foci in the lungs. ROS levels and activation status of p38 MAPK were determined.</p> <p>Results</p> <p>PyMT mice expressing mCAT had a 12.5 per cent incidence of high histological grade primary tumor invasiveness compared to a 62.5 per cent incidence in PyMT mice without mCAT. The histological grade correlated with incidence of metastasis with 56 per cent of PyMT mice positive for mCAT showing evidence of pulmonary metastasis compared to 85.4 per cent of PyMT mice negative for mCAT with pulmonary metastasis (p ≤ 0.05). PyMT tumor cells expressing mCAT had lower ROS levels and were more resistant to hydrogen peroxide-induced oxidative stress than wild type tumor cells, suggesting that mCAT has the potential of quenching intracellular ROS and subsequent invasive behavior. The metastatic tumor burden in PyMT mice expressing mCAT was 0.1 mm<sup>2</sup>/cm<sup>2 </sup>of lung tissue compared with 1.3 mm<sup>2</sup>/cm<sup>2 </sup>of lung tissue in PyMT mice expressing the wild type allele (p ≤ 0.01), indicating that mCAT could play a role in mitigating metastatic tumor progression at a distant organ site. Expression of mCAT in the lungs increased resistance to hydrogen peroxide-induced oxidative stress that was associated with decreased activation of p38MAPK suggesting ROS signaling is dependent on p38MAPK for at least some of its downstream effects.</p> <p>Conclusion</p> <p>Targeting catalase within mitochondria of tumor cells and tumor stromal cells suppresses ROS-driven tumor progression and metastasis. Therefore, increasing the antioxidant capacity of the mitochondrial compartment could be a rational therapeutic approach for invasive breast cancer.</p> <p>Please see related commentary article: <url>http://www.biomedcentral.com/1741-7015/9/62</url></p

    Mutations in GABRB3

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    Objective: To examine the role of mutations in GABRB3 encoding the b3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. Methods: We performed massive parallel sequencing of GABRB3 in 416 patients with a range of epileptic encephalopathies and childhood-onset epilepsies and recruited additional patients with epilepsy with GABRB3 mutations from other research and diagnostic programs. Results: We identified 22 patients with heterozygous mutations in GABRB3, including 3 probands frommultiplex families. The phenotypic spectrum of the mutation carriers ranged from simple febrile seizures, genetic epilepsies with febrile seizures plus, and epilepsy withmyoclonic-atonic seizures to West syndrome and other types of severe, early-onset epileptic encephalopathies. Electrophysiologic analysis of 7 mutations in Xenopus laevis oocytes, using coexpression of wild-type or mutant beta(3), together with alpha(5) and gamma(2s) subunits and an automated 2-microelectrode voltage-clamp system, revealed reduced GABA-induced current amplitudes or GABA sensitivity for 5 of 7 mutations. Conclusions: Our results indicate that GABRB3 mutations are associated with a broad phenotypic spectrum of epilepsies and that reduced receptor function causing GABAergic disinhibition represents the relevant disease mechanism

    Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

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    BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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