L’acylation des protéines : une fonction cellulaire importante des acides gras saturés

Fatty acid acylation of proteins corresponds to the co- or post-translational covalent linkage of a fatty acid, activated in the form of acyl-CoA, to an amino acid residue of the substrate protein. The cellular fatty acids which are involved in protein acylation are mainly saturated fatty acids. Palmitoylation (S-acylation) corresponds to the reversible attachment of palmitic acid (C16:0) to the side chain of a cysteine residue via a thioester bond. N-terminal myristoylation refers to the covalent attachment of myristic acid (C14:0) by an amide bond to the N-terminal glycine of many eukaryotic and viral proteins. Octanoylation (O-acylation) typically concerns the formation of an ester bond between octanoic acid (caprylic acid, C8:0) and the side chain of a serine residue of the gut and brain peptide ghrelin. An increasing number of proteins (enzymes, receptors, oncogenes, tumor suppressors, proteins involved in signal transduction, eukaryotic and viral structural proteins) have been shown to undergo fatty acid acylation. The acyl moiety can mediate protein subcellular localization, protein–protein interaction or protein–membrane interaction. Therefore, through the covalent modification of proteins, saturated fatty acids exhibit emerging specific and important roles in modulating protein functions. This review provides an overview of the recent findings on the various classes of protein acylation leading to the biological ability of saturated fatty acids to regulate many pathways. Finally, the links between these elucidated biochemical mechanisms and the physiological roles of dietary saturated fatty acids are discussed.     

Patients souffrant de schizophrénie en EHPAD et objectifs de prise en charge par l’équipe de psychiatrie de secteur ?

Old people's home welcomes old subjects presenting more and more numerous psychic and organic pathologies with the headway in age. What are the difficulties met in establishment and which tracks of solutions can be envisaged? What are coverages proposed for the residents living in establishment and who suffer from psychiatric chronic pathologies like the schizophrenia? What role then for the team of Psychiatry of sector?     

Left main coronary dissection after mild chest trauma. Favorable evolution with fibrinolytic and surgical therapies

A 32-year-old woman had acute anterior myocardial infarction after a mild chest trauma (automobile accident). Unstable angina recurred shortly after admission, and extensive dissection of the left coronary artery was demonstrated. Medical therapy including systemic fibrinolysis was started but clinical stabilization and good long-term result was achieved only by aortocoronary bypass grafting.     

Development of a Conceptual Framework for Understanding Shared Decision making Among African-American LGBT Patients and their Clinicians

BACKGROUND

Enhancing patient-centered care and shared decision making (SDM) has become a national priority as a means of engaging patients in their care, improving treatment adherence, and enhancing health outcomes. Relatively little is known about the healthcare experiences or shared decision making among racial/ethnic minorities who also identify as being LGBT. The purpose of this paper is to understand how race, sexual orientation and gender identity can simultaneously influence SDM among African-American LGBT persons, and to propose a model of SDM between such patients and their healthcare providers.

METHODS

We reviewed key constructs necessary for understanding SDM among African-American LGBT persons, which guided our systematic literature review. Eligible studies for the review included English-language studies of adults (≥ 19 y/o) in North America, with a focus on LGBT persons who were African-American/black (i.e., > 50 % of the study population) or included sub-analyses by sexual orientation/gender identity and race. We searched PubMed, CINAHL, ProQuest Dissertations & Theses, PsycINFO, and Scopus databases using MESH terms and keywords related to shared decision making, communication quality (e.g., trust, bias), African-Americans, and LGBT persons. Additional references were identified by manual reviews of peer-reviewed journals’ tables of contents and key papers’ references.

RESULTS

We identified 2298 abstracts, three of which met the inclusion criteria. Of the included studies, one was cross-sectional and two were qualitative; one study involved transgender women (91 % minorities, 65 % of whom were African-Americans), and two involved African-American men who have sex with men (MSM). All of the studies focused on HIV infection. Sexual orientation and gender identity were patient-reported factors that negatively impacted patient/provider relationships and SDM. Engaging in SDM helped some patients overcome normative beliefs about clinical encounters. In this paper, we present a conceptual model for understanding SDM in African-American LGBT persons, wherein multiple systems of social stratification (e.g., race, gender, sexual orientation) influence patient and provider perceptions, behaviors, and shared decision making.

DISCUSSION

Few studies exist that explore SDM among African-American LGBT persons, and no interventions were identified in our systematic review. Thus, we are unable to draw conclusions about the effect size of SDM among this population on health outcomes. Qualitative work suggests that race, sexual orientation and gender work collectively to enhance perceptions of discrimination and decrease SDM among African-American LGBT persons. More research is needed to obtain a comprehensive understanding of shared decision making and subsequent health outcomes among African-Americans along the entire spectrum of gender and sexual orientation.

     

Methimazole Slows Hepatocyte Streaming in Rats

Hepatocytes are hypothesized to continuallystream from the portal tract to the terminal hepaticvein. By this model, when a cell divides, one of itsprogeny replaces the dividing ancestor and the other is displaced into a more remote location. Thepresent experiment aims to demonstrate thathypothyroidism affects liver cell turnover. Thirty maleadult rats were divided into two groups. One receivedmethimazole for two weeks and the other served as control.Each rat was injected intraperitoneally with 18.5 KBq[³H]thymidine/g body weight. Rats were killedafter 1 hr and two and four weeks. Autoradiography was done. The distance of the labeled cells fromthe portal tract was measured. The mean TSH levels ofthe methimazole-treated group and controls were 1.45 and0.25 mM/liter, respectively (P < 0.01). Hepatocyte streaming was lower in hypothyroid (1.8m/day) than in untreated rats (2.5 m/day) (P< 0.01). The respective labeling indices 1 hr afterlabeling were 0.9% and 1.24% (P < 0.05). We concludethat hypothyroidism diminishes hepatocyte and littoral cellturnover and slows down their streaming.     

The effects of nasal continuous positive airway pressure on platelet activation in obstructive sleep apnea syndrome

OBJECTIVE: A case-controlled study to assess the effects of nasal continuous positive airway pressure (CPAP) on platelet activation in patients with obstructive sleep apnea (OSAS) syndrome. METHODS: We recruited 65 patients with suspected OSAS for this study. Blood samples were taken with the patient in the supine position in the morning immediately after polysomnography, and 1 night and 3 months after the start of nasal CPAP therapy to measure an index of platelet activation (IPA+), which reflected both the quantity and quality of platelet activation. Significant OSAS was defined as an apnea-hypopnea index (AHI) of > or = 10 events per hour. RESULTS: There were 42 patients with significant OSAS and 23 control subjects with AHI < 10 events per hour. The mean (+/- SD) age for the OSAS patients was 48 +/- 9 years, the mean body mass index was 30.7 +/- 4.8, the mean AHI was 47 +/- 25 events per hour, the mean arousal index (AI) was 37 +/- 23 events per hour, and the mean minimum arterial oxygen saturation was 74 +/- 11%. Following multiple linear regression analyses of the clinical and polysomnography parameters, AI was the independent factor that correlated best with the baseline IPA+ (beta-coefficient, 0.386; p = 0.006). Following nasal CPAP treatment with a mean objective CPAP compliance of 3.9 +/- 1.9 h per night, there was a significant decrease in IPA+ from 15.1 +/- 12.2 U (at baseline) to 12.2 +/- 5.2 U (p < 0.001) and 9.8 +/- 4.3 U (p = 0.005), respectively, after 1 night and 3 months, whereas no significant change was noted among the control subjects. Using univariate analysis of variance to compare the changes in IPA+ between the two groups at 3 months with adjustment for the baseline value, nasal CPAP reduced IPA+ by 5.63 (SE, 1.85), whereas IPA+ increased in control subjects by 1.33 (SE, 1.27) [least-squared mean difference between groups, 3.34; 95% confidence interval, 0.42 to 6.26; p = 0.026]. CONCLUSIONS: OSAS, through repeated episodes of arousals, may lead to platelet activation, which can be reduced by nasal CPAP therapy.     

Usefulness of ultrasonography in predicting pleural effusions > 500 mL in patients receiving mechanical ventilation

STUDY OBJECTIVE: To assess the accuracy of chest ultrasonography in predicting pleural effusions > 500 mL in patients receiving mechanical ventilation. DESIGN: Prospective study. SETTING: Surgical and medical ICU in a teaching hospital. PATIENTS: Forty-four patients receiving mechanical ventilation with indications of chest drainage of a nonloculated pleural effusion. INTERVENTIONS: Diagnosis of pleural effusion was based on clinical examination and chest radiography. Chest drainage was indicated when considered as potentially useful for the patient (hypoxemia and/or weaning failure). Sonograms were performed before drainage at the bedside, in the supine position, and measurements were performed at the end of expiration. Effusions were classified as > 500 mL or < or = 500 mL according to the drained volume. MEASUREMENTS AND RESULTS: The drained volume ranged from 100 to 1,800 mL (mean, 730 +/- 440 mL [+/- SD]). The distance between the lung and posterior chest wall at the lung base (PLDbase) and the distance between the lung and posterior chest wall at the fifth intercostal space (PLD5) were significantly correlated with the drained volume (PLDbase, r = 0.68, p < 0.001; PLD5, r = 0.56, p < 0.001). A PLDbase > 5 cm predicted a drained volume > 500 mL with a sensitivity of 83%, specificity of 90%, positive predictive value of 91%, and negative predictive value of 82%. Interobserver and intraobserver percentages of error were, respectively, 7 +/- 6% and 9 +/- 6% for PLDbase, and 6 +/- 5% and 8 +/- 5% for PLD5. The PaO2/fraction of inspired oxygen ratio significantly increased after chest drainage in patients with collected volumes > 500 mL (p < 0.01). CONCLUSIONS: Bedside pleural ultrasonography accurately predicted a nonloculated pleural effusion > 500 mL in patients receiving mechanical ventilation using simple and reproducible measurements.