Recognition of a subregion of human proinsulin by class I-restricted T cells in type 1 diabetic patients

Proinsulin is a key autoantigen in type 1 diabetes. Evidence in the mouse has underscored the importance of the insulin B chain region in autoimmunity to pancreatic beta cells. In man, a majority of proteasome cleavage sites are predicted by proteasome cleavage algorithms within this region. To study CD8+ T cell responses to the insulin B chain and adjacent C peptide, we selected 8- to 11-mer peptides according to proteasome cleavage patterns obtained by digestion of two peptides covering proinsulin residues 28 to 64. We studied their binding to purified HLA class I molecules and their recognition by T cells from diabetic patients. Peripheral blood mononuclear cells from 17 of 19 recent-onset and 12 of 13 long-standing type 1 diabetic patients produced IFN-gamma in response to proinsulin peptides as shown by using an ELISPOT assay. In most patients, the response was against several class I-restricted peptides. Nine peptides were recognized within the proinsulin region covering residues 34 to 61. Four yielded a high frequency of recognition in HLA-A1 and -B8 patients. Three peptides located in the proinsulin region 41-51 were shown to bind several HLA molecules and to be recognized in a high percentage of diabetic patients.     

Lung ultrasonography for assessment of oxygenation response to prone position ventilation in ARDS

Purpose

Prone position (PP) improves oxygenation and outcome of acute respiratory distress syndrome (ARDS) patients with a PaO₂/FiO₂ ratio <150 mmHg. Regional changes in lung aeration can be assessed by lung ultrasound (LUS). Our aim was to predict the magnitude of oxygenation response after PP using bedside LUS.

Methods

We conducted a prospective multicenter study that included adult patients with severe and moderate ARDS. LUS data were collected at four time points: 1 h before (baseline) and 1 h after turning the patient to PP, 1 h before and 1 h after turning the patient back to the supine position. Regional lung aeration changes and ultrasound reaeration scores were assessed at each time. Overdistension was not assessed.

Results

Fifty-one patients were included. Oxygenation response after PP was not correlated with a specific LUS pattern. The patients with focal and non-focal ARDS showed no difference in global reaeration score. With regard to the entire PP session, the patients with non-focal ARDS had an improved aeration gain in the anterior areas. Oxygenation response was not associated with aeration changes. No difference in PaCO₂ change was found according to oxygenation response or lung morphology.

Conclusions

In ARDS patients with a PaO₂/FiO₂ ratio ≤150 mmHg, bedside LUS cannot predict oxygenation response after the first PP session. At the bedside, LUS enables monitoring of aeration changes during PP.

     

Étude du Transport INTrA-Hospitalier du MAlade de Réanimation (TINTAHMAR)

Introduction

Intra-hospital transport (IHT) of critically ill patients is a frequent care associated with an important risk of adverse events (AEs). To decrease the occurrence of AEs, recent guidelines have been edited. Their consequences on adverse event incidence and nurse workload have not been assessed.

Aim of study

The primary objective was to assess the time necessary for the achievement of IHT. Secondary objectives were to describe practices related to IHT, to compare workload according to the presence of nurses during the IHT, and to assess the occurrence of AEs.

Patients and methods

This French multicentric observational study conducted by the SRLF was conducted in 18 French-speaking intensive care units. All critically ill adults requiring IHT were included.

Results

Three hundred and ninety-six IHTs (mean age 61 ±19, mean IGS II 46±24) were assessed. The mean duration of IHT was 67±35 minutes. There was a training program of IHT in only 11% of centers, a check-list in 22%, and traceability procedures in 17%. There was a nurse during the IHT in 51% of cases. The presence of a nurse had no consequence on IHT durations. Adverse events occurred in 15% of IHT. In multivariable analysis, nurse presence was not associated with IHT associated AEs.

Conclusion

An IHT requires time. Despite the poor adherence to the guidelines, this care was associated with low incidence of AES. The presence of nurses during the IHT had no consequence on IHT duration and AEs occurrence.

     

Alström Syndrome: Mutation Spectrum of ALMS1

Alström Syndrome (ALMS), a recessive, monogenic ciliopathy caused by mutations in ALMS1, is typically characterized by multisystem involvement including early cone‐rod retinal dystrophy and blindness, hearing loss, childhood obesity, type 2 diabetes mellitus, cardiomyopathy, fibrosis, and multiple organ failure. The precise function of ALMS1 remains elusive, but roles in endosomal and ciliary transport and cell cycle regulation have been shown. The aim of our study was to further define the spectrum of ALMS1 mutations in patients with clinical features of ALMS. Mutational analysis in a world‐wide cohort of 204 families identified 109 novel mutations, extending the number of known ALMS1 mutations to 239 and highlighting the allelic heterogeneity of this disorder. This study represents the most comprehensive mutation analysis in patients with ALMS, identifying the largest number of novel mutations in a single study worldwide. Here, we also provide an overview of all ALMS1 mutations identified to date.     

Lung real time three-dimensional imaging in critically ill ventilated patients: a global diagnosis concordance study

Lung ultrasound (LUS) increases clinical diagnosis performance in intensive care unit (ICU). Real-time three-dimensional (3-D) imaging was compared with two-dimensional (2-D) LUS by assessing the global diagnosis concordance. In this single center, prospective, observational, pilot study, one trained operator performed a 3-D LUS immediately after a 2-D LUS in eight areas of interest on the same areas in 16 ventilated critically ill patients. All cine loops were recorded on a computer without visible link between 2-D and 3-D exams. Two experts blindly reviewed cine loops. Four main diagnoses were proposed: normal lung, consolidation, pleural effusion and interstitial syndrome. Fleiss κ and Cohen’s κ values were calculated. In 252 LUS cine loops, the concordance between 2-D and 3-D exams was 83.3% (105/126), 77.6% (99/126) and 80.2% (101/126) for the trained operator and the experts respectively. The Cohen’s κ coefficient value was 0.69 [95% Confidence Interval (CI) 0.58–0.80] for expert 1 meaning a substantial agreement. The inter-rater reliability was very good (Fleiss’ κ value?=?0.94 [95% CI 0.87–1.0]) for 3-D exams. The Cohen’s κ was excellent for pleural effusion (κ=?0.93 [95% CI 0.76–1.0]), substantial for normal lung diagnosis (κ?=?0.68 [95% CI 0.51–0.86]) and interstitial syndrome (κ?=?0.62 [95% CI 0.45–0.80]) and fair for consolidation diagnoses (κ?=?0.47 [95% CI 0.30–0.64]). In ICU ventilated patients, there was a substantial concordance between 2-D and 3-D LUS with a good inter-rater reliability. However, the diagnosis concordance for lung consolidation is poor.     

Smooth Muscle-associated Contractile Protein in Human and Experimental Acute Leukaemias*

Summary: Smooth muscle-associated contractile protein in human and experimental acute leukaemias. Cells from ten human myeloblastic leukaemias and from spontaneous rat myeloblastic and lymphoblastic leukaemias were examined by indirect immunofluorescence with human serum containing smooth muscle antibody. Strong positive cell outline staining of blast cells was seen in cryostat sections of rat leukaemic lymph nodes, spleen and liver. In cell smears of human and rat leukaemias, cell outline fluorescence was restricted to cells in close contact with each other. Membrane immunofluorescence tests of suspensions of viable leukaemic cells were negative. Specificity of the immunofluor-escent staining reaction was established by failure to obtain staining with normal serum, or with smooth muscle antibody serum neutralized by homogenates of smooth muscle or extracts containing actin derived from smooth muscle. These observations suggest that smooth muscle-associated microfilaments are present in leukaemic blast cells and that expression of the antigen is dependent on cell- cell contact. The presence of this antigen may facilitate leukaemic infiltration of tissues.     

Effects of sodium valproate and diazepam on beta-endorphin, beta-lipotropin and cortisol secretion induced by hypoglycemic stress in humans

Evidence that gamma-aminobutyric acid (GABA) and benzodiazepine receptors play a role in the inhibition of ACTH-cortisol secretion in humans has until now been drawn only from data indicating that sodium valproate, a GABA mimetic, and diazepam, a benzodiazepine, decrease hypothalamus-pituitary-adrenal (HPA) axis secretion in patients affected by pathological hypersecretion of the axis. Therefore, the present study investigated the effects, in the same healthy subjects, of sodium valproate or diazepam, on both basal and stress-stimulated concentrations of beta-endorphin (beta-EP), beta-lipotropin (beta-LPH) and cortisol. A single maximal dose of sodium valproate (400 mg) or diazepam (10 mg) did not significantly modify basal concentrations of beta-EP, beta-LPH and cortisol. On the other hand, in the same subjects, pretreatment with sodium valproate (20 mg X 3) or diazepam (10 mg X 2) blocked the increases in these hormones produced by hypoglycemic stress in all patients tested (p less than 0.01 vs. placebo at 45, 60 and 90 min after insulin injection), without affecting the decrease in blood glucose levels. The present data show that sodium valproate and diazepam inhibit stress-induced beta-EP, beta-LPH and cortisol secretion in humans, suggesting that endogenous GABA and benzodiazepine receptors participate in physiological mechanisms regulating the activity of the HPA axis.