GABAB receptor cell-surface export is controlled by an endoplasmic reticulum gatekeeper.

Endoplasmic reticulum (ER) release and cell-surface export of many G protein-coupled receptors (GPCRs) are tightly regulated. For gamma-aminobutyric acid (GABA)B receptors of GABA, the major mammalian inhibitory neurotransmitter, the ligand-binding GB1 subunit is maintained in the ER by unknown mechanisms in the absence of hetero-dimerization with the GB2 subunit. We report that GB1 retention is regulated by a specific gatekeeper, PRAF2. This ER resident transmembrane protein binds to GB1, preventing its progression in the biosynthetic pathway. GB1 release occurs upon competitive displacement from PRAF2 by GB2. PRAF2 concentration, relative to that of GB1 and GB2, tightly controls cell-surface receptor density and controls GABAB function in neurons. Experimental perturbation of PRAF2 levels in vivo caused marked hyperactivity disorders in mice. These data reveal an unanticipated major impact of specific ER gatekeepers on GPCR function and identify PRAF2 as a new molecular target with therapeutic potential for psychiatric and neurological diseases involving GABAB function.

Cytomegalovirus infection in intensive care unit patients with hematological malignancies: Characteristics and clinical outcomes.

BACKGROUND: Cytomegalovirus (CMV) infection is associated with poor outcome in ICU patients. However, data on immunocompromised patients are scarce. This study aims to describe characteristics and outcomes of critically ill hematological patients and CMV infection. CMV disease characteristics and relationship between CMV viral load, CMV disease, coinfections by other pathogens and outcomes are described. METHODS: Retrospective single center study (Jan 2010-Dec 2017). Adult patients, admitted to the ICU, having underlying hematological malignancy and CMV infection were included. Results are reported as median (interquartile) or n (%). Factors associated with hospital mortality or CMV disease were analysed using logistic regression. RESULTS: 178 patients were included (median age 55y [42-64], 69.1% male). Hospital mortality was 53% (n = 95). Median viral load was 2.7 Log [2.3-3.5]. CMV disease occurred in 44 (24.7%) patients. Coinfections concerned 159 patients (89.3%). After adjustment for confounders, need for vasopressors (OR 2.53; 95%CI 1.11-5.97) and viral load (OR 1.88 per Log; 95%CI 1.29-2.85) were associated with hospital mortality. However, neither CMV disease nor treatment were associated with outcomes. Allogeneic stem cell transplantation (OR 2.55; 95%CI 1.05-6.16), mechanical ventilation (OR 4.11; OR 1.77-10.54) and viral load (OR 1.77 per Log; 95%CI 1.23-2.61) were independently associated with CMV disease. Coinfections were not associated with CMV disease or hospital mortality. CONCLUSION: In critically-ill hematological patients, CMV viral load is independently associated with hospital mortality. Conversely, neither CMV disease nor treatment was associated with outcome suggesting viral load to be a surrogate for immune status rather than a cause of poor outcome.

Expression and lysosomal targeting of CLN7, a major facilitator superfamily transporter associated with variant late-infantile neuronal ceroid lipofuscinosis.

Neuronal ceroid lipofuscinoses (NCLs) constitute a group of progressive neurodegenerative disorders resulting from mutations in at least eight different genes. Mutations in the most recently identified NCL gene, MFSD8/CLN7, underlie a variant of late-infantile NCL (vLINCL). The MFSD8/CLN7 gene encodes a polytopic protein with unknown function, which shares homology with ion-coupled membrane transporters. In this study, we confirmed the lysosomal localization of the native CLN7 protein. This localization of CLN7 is not impaired by the presence of pathogenic missense mutations or after genetic ablation of the N-glycans. Expression of chimeric and full-length constructs showed that lysosomal targeting of CLN7 is mainly determined by an N-terminal dileucine motif, which specifically binds to the heterotetrameric adaptor AP-1 in vitro. We also show that CLN7 mRNA is more abundant in neurons than astrocytes and microglia, and that it is expressed throughout rat brain, with increased levels in the granular layer of cerebellum and hippocampal pyramidal cells. Interestingly, this cellular and regional distribution is in good agreement with the autofluorescent lysosomal storage and cell loss patterns found in brains from CLN7-defective patients. Overall, these data highlight lysosomes as the primary site of action for CLN7, and suggest that the pathophysiology underpinning CLN7-associated vLINCL is a cell-autonomous process.

Procedure volume is one determinant of centre effect in mechanically ventilated patients.

Survival rates vary significantly between intensive care units, most notably in patients requiring mechanical ventilation (MV). The present study sought to estimate the effect of hospital MV volume on hospital mortality. We included 179,197 consecutive patients who received mechanical ventilation in 294 hospitals. Multivariate logistic regression models with random intercepts were used to estimate the effect of annual MV volume in each hospital, adjusting for differences in severity of illness and case mix. Median annual MV volume was 162 patients (interquartile range 99-282). Hospital mortality in MV patients was 31.4% overall, 40.8% in the lowest annual volume quartile and 28.2% in the highest quartile. After adjustment for severity of illness, age, diagnosis and organ failure, higher MV volume was associated with significantly lower hospital mortality among MV patients (OR 0.9985 per 10 additional patients, 95% CI 0.9978-0.9992; p = 0.0001). A significant centre effect on hospital mortality persisted after adjustment for volume effect (p < 0.0001). Our study demonstrated higher hospital MV volume to be independently associated with increased survival among MV patients. Significant differences in outcomes persisted between centres after adjustment for hospital MV volume, supporting a role for other significant determinants of the centre effect.

Herpesvirus reactivation during severe COVID-19 and high rate of immune defect.

OBJECTIVE: We assessed herpesvirus reactivation in severe SARS-CoV-2 infection. METHODS: Retrospective study including consecutive patients admitted to an onco-hematology intensive care unit (ICU) for severe COVID-19. Replication of EBV, CMV, and HSV was evaluated. Competing risk analyses were used to assess the cumulative risk of viral reactivation, and time-dependent Cox and Fine and Gray models to assess risk factors for viral reactivation. RESULTS: Among 100 patients, 38 were immunocompromised. Sixty-three patients presented viral reactivation (12% for HSV, 58% EBV and 19% CMV). Symptomatic patients received treatment. Overall cumulative incidence of viral reactivation was 56.1% [55.9-56.4] at 10 days. After adjustment, a preexisting hematological malignancy (sHR [95%CI]=0.31 [0.11-0.85]) and solid organ transplantation (sHR [95% CI]=2.09 [1.13-3.87]) remained independently associated with viral reactivation. Viral reactivation (P=0.34) was not associated with mortality. CONCLUSIONS: Incidence of herpesvirus reactivation in patients admitted to the ICU for severe COVID-19 was high, but rarely required antiviral treatment.

Report of the first AKI Round Table meeting: an initiative of the ESICM AKI Section.

PURPOSE: Critical Care Nephrology is an emerging sub-specialty of Critical Care. Despite increasing awareness about the serious impact of acute kidney injury (AKI) and renal replacement therapy (RRT), important knowledge gaps persist. This report represents a summary of a 1-day meeting of the AKI section of the European Society of Intensive Care Medicine (ESICM) identifying priorities for future AKI research. METHODS: International Members of the AKI section of the ESICM were selected and allocated to one of three subgroups: "AKI diagnosis and evaluation", "Medical management of AKI" and "Renal Replacement Therapy for AKI." Using a modified Delphi methodology, each group identified knowledge gaps and developed potential proposals for future collaborative research. RESULTS: The following key research projects were developed: Systematic reviews: (a) epidemiology of AKI with stratification by patient cohorts and diagnostic criteria; (b) role of higher blood pressure targets in patients with hypertension admitted to the Intensive Care Unit, and (c) specific clearance characteristics of different modalities of continuous renal replacement therapy (CRRT). Observational studies: (a) epidemiology of critically ill patients according to AKI duration, and (b) current clinical practice of CRRT. Intervention studies:( a) Comparison of different blood pressure targets in critically ill patients with hypertension, and (b) comparison of clearance of solutes with various molecular weights between different CRRT modalities. CONCLUSION: Consensus was reached on a future research agenda for the AKI section of the ESICM.

[Coordination of health vigilances: for a global management of hospital risks]. / La coordination des vigilances sanitaires : pour une gestion plus globale des risques hospitaliers.

The sanitary vigilances represent a permanent sanitary surveillance. They signal, enregister, treat and investigate the adverse events occurring through the use of health products. They assure the traceability of these health products and the management of the sanitary alerts. The sanitary vigilances are part of the sanitary security. They are optimized when coordinated and integrated to the global risk management process of the health care establishments.

ICU survival and need of renal replacement therapy with respect to AKI duration in critically ill patients.

BACKGROUND: Transient and persistent acute kidney injury (AKI) could share similar physiopathological mechanisms. The objective of our study was to assess prognostic impact of AKI duration on ICU mortality. DESIGN: Retrospective analysis of a prospective database via cause-specific model, with 28-day ICU mortality as primary end point, considering discharge alive as a competing event and taking into account time-dependent nature of renal recovery. Renal recovery was defined as a decrease of at least one KDIGO class compared to the previous day. SETTING: 23 French ICUs. PATIENTS: Patients of a French multicentric observational cohort were included if they suffered from AKI at ICU admission between 1996 and 2015. INTERVENTION: None. RESULTS: A total of 5242 patients were included. Initial severity according to KDIGO creatinine definition was AKI stage 1 for 2458 patients (46.89%), AKI stage 2 for 1181 (22.53%) and AKI stage 3 for 1603 (30.58%). Crude 28-day ICU mortality according to AKI severity was 22.74% (n = 559), 27.69% (n = 327) and 26.26% (n = 421), respectively. Renal recovery was experienced by 3085 patients (58.85%), and its rate was significantly different between AKI severity stages (P < 0.01). Twenty-eight-day ICU mortality was independently lower in patients experiencing renal recovery [CSHR 0.54 (95% CI 0.46-0.63), P < 0.01]. Lastly, RRT requirement was strongly associated with persistent AKI whichever threshold was chosen between day 2 and 7 to delineate transient from persistent AKI. CONCLUSIONS: Short-term renal recovery, according to several definitions, was independently associated with higher mortality and RRT requirement. Moreover, distinction between transient and persistent AKI is consequently a clinically relevant surrogate outcome variable for diagnostic testing in critically ill patients.

Outcome in patients perceived as receiving excessive care across different ethical climates: a prospective study in 68 intensive care units in Europe and the USA.

PURPOSE: Whether the quality of the ethical climate in the intensive care unit (ICU) improves the identification of patients receiving excessive care and affects patient outcomes is unknown. METHODS: In this prospective observational study, perceptions of excessive care (PECs) by clinicians working in 68 ICUs in Europe and the USA were collected daily during a 28-day period. The quality of the ethical climate in the ICUs was assessed via a validated questionnaire. We compared the combined endpoint (death, not at home or poor quality of life at 1 year) of patients with PECs and the time from PECs until written treatment-limitation decisions (TLDs) and death across the four climates defined via cluster analysis. RESULTS: Of the 4747 eligible clinicians, 2992 (63%) evaluated the ethical climate in their ICU. Of the 321 and 623 patients not admitted for monitoring only in ICUs with a good (n = 12, 18%) and poor (n = 24, 35%) climate, 36 (11%) and 74 (12%), respectively were identified with PECs by at least two clinicians. Of the 35 and 71 identified patients with an available combined endpoint, 100% (95% CI 90.0-1.00) and 85.9% (75.4-92.0) (P = 0.02) attained that endpoint. The risk of death (HR 1.88, 95% CI 1.20-2.92) or receiving a written TLD (HR 2.32, CI 1.11-4.85) in patients with PECs by at least two clinicians was higher in ICUs with a good climate than in those with a poor one. The differences between ICUs with an average climate, with (n = 12, 18%) or without (n = 20, 29%) nursing involvement at the end of life, and ICUs with a poor climate were less obvious but still in favour of the former. CONCLUSION: Enhancing the quality of the ethical climate in the ICU may improve both the identification of patients receiving excessive care and the decision-making process at the end of life.

Serotonin transporter overexpression is responsible for pulmonary artery smooth muscle hyperplasia in primary pulmonary hypertension.

Hyperplasia of pulmonary artery smooth muscle cells (PA-SMCs) is a hallmark pathological feature of primary pulmonary hypertension (PPH). Here we found that PA-SMCs from patients with PPH grow faster than PA-SMCs from controls when stimulated by serotonin or serum and that these effects are due to increased expression of the serotonin transporter (5-HTT), which mediates internalization of indoleamine. In the presence of 5-HTT inhibitors, the growth stimulatory effects of serum and serotonin were markedly reduced and the difference between growth of PA-SMCs from patients and controls was no longer observed. As compared with controls, the expression of 5-HTT was increased in cultured PA-SMCs as well as in platelets and lungs from patients with PPH where it predominated in the media of thickened pulmonary arteries and in onion-bulb lesions. The L-allelic variant of the 5HTT gene promoter, which is associated with 5-HTT overexpression and increased PA-SMC growth, was present in homozygous form in 65% of patients but in only 27% of controls. We conclude that 5-HTT activity plays a key role in the pathogenesis of PA-SMC proliferation in PPH and that a 5HTT polymorphism confers susceptibility to PPH.

Renal recovery after acute kidney injury.

Acute kidney injury (AKI) is a frequent complication of critical illness and carries a significant risk of short- and long-term mortality, chronic kidney disease (CKD) and cardiovascular events. The degree of renal recovery from AKI may substantially affect these long-term endpoints. Therefore maximising recovery of renal function should be the goal of any AKI prevention and treatment strategy. Defining renal recovery is far from straightforward due in part to the limitations of the tests available to assess renal function. Here, we discuss common pitfalls in the evaluation of renal recovery and provide suggestions for improved assessment in the future. We review the epidemiology of renal recovery and of the association between AKI and the development of CKD. Finally, we stress the importance of post-discharge follow-up of AKI patients and make suggestions for its incorporation into clinical practice. Summary key points are that risk factors for non-recovery of AKI are age, CKD, comorbidity, higher severity of AKI and acute disease scores. Second, AKI and CKD are mutually related and seem to have a common denominator. Third, despite its limitations full recovery of AKI may best be defined as the absence of AKI criteria, and partial recovery as a fall in AKI stage. Fourth, after an episode of AKI, serial follow-up measurements of serum creatinine and proteinuria are warranted to diagnose renal impairment and prevent further progression. Measures to promote recovery are similar to those preventing renal harm. Specific interventions promoting repair are still experimental.

Noninvasive ventilation during acute respiratory distress syndrome in patients with cancer: Trends in use and outcome.

PURPOSE: The objectives of our study were to describe the outcome of patients with malignancies treated for acute respiratory distress syndrome (ARDS) with noninvasive ventilation (NIV) and to evaluate factors associated with NIV failure. METHODS: Post hoc analysis of a multicenter database within 20 years was performed. All patients with malignancies and Berlin ARDS definition were included. Noninvasive ventilation use was defined as NIV lasting more than 1 hour, whereas failure was defined as a subsequent requirement of invasive ventilation. Conditional backward logistic regression analyses were conducted. RESULTS: A total of 1004 met the Berlin definition of ARDS. Noninvasive ventilation was used in 387 patients (38.6%) and NIV failure occurred in 71%, with an in-hospital mortality of 62.7%. Severity of ARDS defined by the partial pressure arterial oxygen and fraction of inspired oxygen ratio (odds ratio [OR], 2.20; 95% confidence interval [CI], 1.15-4.19), pulmonary infection (OR, 1.81; 95% CI, 1.08-3.03), and modified Sequential Organ Failure Assessment (SOFA) score (OR, 1.13; 95% CI, 1.06-1.21) were associated with NIV failure. Factors associated with hospital mortality were NIV failure (OR, 2.52; 95% CI, 1.56-4.07), severe ARDS as compared with mild ARDS (OR, 1.89; 95% CI, 1.05-1.19), and modified SOFA score (OR, 1.12; 95% CI, 1.05-1.19). CONCLUSION: Noninvasive ventilation failure in ARDS patients with malignancies is frequent and related to ARDS severity, SOFA score, and pulmonary infection-related ARDS. Noninvasive ventilation failure is associated with in-hospital mortality.

Combined hyperlipidemia/hyperalphalipoproteinemia associated with premature spontaneous atherosclerosis in mice lacking hepatic lipase and low density lipoprotein receptor.

BACKGROUND AND METHODS: Hepatic lipase (HL) is an enzyme which hydrolyzes triglycerides from plasma lipoproteins and thus takes part in the metabolism of triglyceride-rich lipoprotein remnants and high density lipoproteins. The search described here concentrated on the description of the double invalidation of the HL and LDL receptor genes in mice in order to better understand the possible role of HL in combined hyperlipidemia/hyperalphalipoproteinemia and development of atherosclerosis. RESULTS: We show here that mice lacking both endogenous HL and LDL receptor (HL-/-:LDLR-/-) dramatically increased their plasma triglyceride-rich lipoproteins and their remnants as a consequence of reduced liver uptake. This result is strenghthened by the fact that HL-/-:LDLR-/- were found to overexpress LRP, LSR, and apoE genes. Interestingly, HL-/-:LDLR-/- mice showed premature spontaneous atherosclerosis and aortic lesions from 1-year-old animals were two-fold larger than those of LDLR-/- single mutants. We confirmed that HL-/- and wild-type mice did not develop atherosclerosis lesion even 1 year after birth. CONCLUSIONS: Analysis of this double HL-LDLR knockout mouse model provides in vivo evidence that HL has a major role in the clearance of TRL remnants when LDLR is deficient and in the reduction of the development of atherosclerosis.

[Prevalence of pressure sores in a university hospital in 2003]. / L'escarre à l'hôpital en 2003: enquête de prévalence un jour donné.

BACKGROUND: To determine the prevalence of pressure sores in a university hospital and to assess the risk of developing a pressure sore. METHODS: A one-day survey was performed in all hospitalized patients, day hospital excepted. The Garches scale was used to assess the severity of pressure sores and the Braden scale was used to measure the patient's risk for the development of pressure ulcers. RESULTS: One thousand six hundred and eleven patients were included, mean age was 62+/-23 years and 53.3% were over 65 years old. In hospitalized patients, 64% were in acute care, 29% in intermediate medicine and long-term care and 7% in intensive care units. We have found 675 pressure sores in 268 patients, mean age of 76 years; 263 decubitus ulcers were acquired during hospitalization. The most frequent sites were heels (46%) and sacrum (26%). Stage 1 pressure ulcers showed 33% of the total. The total prevalence was 16.6%, 95% CI (14.9-18.6), the hospital acquired pressure sores prevalence was 7.5%, all stages included. A Braden score less than or equal to 15 was found in 29.1% of hospitalized patients. Standard mattresses were used in 37% of patients with pressure sores. Multivariate analysis showed that age and a Braden score less than or equal to 15 were significantly associated with pressure sores. CONCLUSION: Pressure sores are still an important problem in hospital; occurrence must be considered as an iatrogenic event and management requires a multidisciplinary approach.

Reexpression of fetal characters in simian virus 40-transformed human keratinocytes.

Normal human keratinocytes are able to stratify, form cornified squames, and terminally differentiate in tissue culture. These properties are frequently impaired by malignant transformation. In the present paper, we show that, in addition, transformation by SV40 results in the coordinate reexpression of a whole set of fetal characters. Moreover, a comparison of two SV40-transformed human keratinocyte cell lines, one still showing a certain degree of stratification and terminal differentiation (HE-SV) and the other almost completely unable to differentiate (SVK14), suggests that the impairment of differentiation and the intensity of reexpression of fetal markers are correlated. Particularly, a set of three keratin polypeptides, absent in adult stratified epithelia but normally found in the nonstratified fetal epidermis, is present in much larger amounts in SVK14 cells than in HE-SV cells. On the other hand, the inability of SVK14 cells, in contrast to HE-SV cells, to form cornified envelopes seems to be due to the inability of those cells to accumulate involucrin.

Numerical comparison of acoustic wedge models, with application to ultrasonic telemetry.

Ultrasonic telemetry imaging systems are used to monitor such immersed structures as main vessels of nuclear reactors. The interaction between acoustic beams and targets involves scattering phenomena, mainly specular reflection and tip diffraction. In order to assist in the design of imaging systems, a simulation tool is required for the accurate modeling of such phenomena. Relevant high-frequency scattering models have been developed in electromagnetic applications, in particular, the geometrical optics (GO), Geometrical Theory of Diffraction (GTD) and its uniform corrections (UAT and UTD), Kirchhoff approximation (KA) and Physical Theory of Diffraction (PTD). Before adopting any of them for simulation of scattering of acoustic waves by edged immersed rigid bodies, it is important to realize that in acoustics the characteristic dimension to the wave length ratio is usually considerably smaller than in electromagnetics and a further study is required to identify models' advantages, disadvantages and regions of applicability. In this paper their numerical comparison is carried out. As the result, the most suitable algorithm is identified for simulating ultrasonic telemetry of immersed rigid structures.

A system model for ultrasonic NDT based on the Physical Theory of Diffraction (PTD).

Simulation of ultrasonic Non Destructive Testing (NDT) is helpful for evaluating performances of inspection techniques and requires the modelling of waves scattered by defects. Two classical flaw scattering models have been previously usually employed and evaluated to deal with inspection of planar defects, the Kirchhoff approximation (KA) for simulating reflection and the Geometrical Theory of Diffraction (GTD) for simulating diffraction. Combining them so as to retain advantages of both, the Physical Theory of Diffraction (PTD) initially developed in electromagnetism has been recently extended to elastodynamics. In this paper a PTD-based system model is proposed for simulating the ultrasonic response of crack-like defects. It is also extended to provide good description of regions surrounding critical rays where the shear diffracted waves and head waves interfere. Both numerical and experimental validation of the PTD model is carried out in various practical NDT configurations, such as pulse echo and Time of Flight Diffraction (TOFD), involving both crack tip and corner echoes. Numerical validation involves comparison of this model with KA and GTD as well as the Finite-Element Method (FEM).

Dominant role of the cytosolic C-terminal domain of the rat 5-HT1B receptor in axonal-apical targeting.

The 5-HT(1A) and 5-HT(1B) receptors for serotonin exhibit a different membrane localization to either soma and dendrites (5-HT(1A)R) or axons and terminals (5-HT(1B)R) of neurons in the CNS. The mechanisms responsible for their differential targeting were investigated previously by transfecting various 5-HT(1A)R/5-HT(1B)R chimeras in the epithelial Lilly pork kidney (LLC-PK1) cell line. This first study suggested that a specific targeting signal is located in the C-terminal portion (comprising the last two transmembrane and the cytoplasmic C-terminal domains) of the 5-HT(1A)and/or 5-HT(1B) receptors. In the present study, the role of the cytosolic C-terminal tail of the receptors was further investigated by transfecting truncated receptors and 5-HT(1A)R/5-HT(1B)R chimeras in both the epithelial LLC-PK1 cells and rat hippocampal neurons in primary culture. Confocal microscopic analysis of immunofluorescence with specific anti-5-HTR antibodies and anti-microtubule-associated protein 2 or anti-neurofilament 200k antibodies showed that substitution of the cytosolic C-terminal tail of the 5-HT(1B)R in the 5-HT(1A)R addressed the resulting chimera to the axon of neurons and to the apical domain of LLC-PK1 cells. Therefore, the short tail of the 5-HT(1B)R presents an apical targeting signal that can also act as an axonal targeting signal. In addition, a domain within the third intracytoplasmic loop of the 5-HT(1B)R, responsible for its Golgi sequestration in LLC-PK1 cells, appeared to act as another axonal targeting signal in hippocampal neurons.

Changes in pattern and accessibility for 125I-labelling of cell-surface proteins after mesenchymal differentiation of embryonal carcinoma cells.

Cell-surface proteins of the embryonal carcinoma line C17-S1 1003 (1003) and of some of its mesenchymal derivatives were studied. The surface proteins were labelled with 125I using the lactoperoxidase-glucose-glucose oxidase system either on the cells attached to the culture dishes or after their dissociation. Iodinated proteins were analyzed by two-dimensional gel electrophoresis. The patterns obtained with embryonal carcinoma cells 1003 and with two mesenchymal cell types derived from them, namely embryonic mesenchymal cells (line 10035) and fibroblastic cells (line 10031), were different one from the other, especially when considering the group of proteins labelled on the attached cells. The pattern of cell-surface proteins of the myoblastic line 1168, also derived from C17-S1, was found to be similar to that of 10031 fibroblastic cells. This result is discussed in the light of the phenotypic transition toward myogenesis, which can be obtained with 10031 fibroblastic cells but not with 10035 embryonic mesenchymal cells. A direct method of detection of lectin-binding proteins permitted us to identify the major concanavalin A-binding proteins. Two of them are common to all cell lines studied. They were labeled with 125I on the attached undifferentiated 1003 cells, while in all differentiated derivatives they became available for labelling after the cell detachment only.