Assembly of a unique membrane complex in type VI secretion systems of Bacteroidota.

The type VI secretion system (T6SS) of Gram-negative bacteria inhibits competitor cells through contact-dependent translocation of toxic effector proteins. In Proteobacteria, the T6SS is anchored to the cell envelope through a megadalton-sized membrane complex (MC). However, the genomes of Bacteroidota with T6SSs appear to lack genes encoding homologs of canonical MC components. Here, we identify five genes in Bacteroides fragilis (tssNQOPR) that are essential for T6SS function and encode a Bacteroidota-specific MC. We purify this complex, reveal its dimensions using electron microscopy, and identify a protein-protein interaction network underlying the assembly of the MC including the stoichiometry of the five TssNQOPR components. Protein TssN mediates the connection between the Bacteroidota MC and the conserved baseplate. Although MC gene content and organization varies across the phylum Bacteroidota, no MC homologs are detected outside of T6SS loci, suggesting ancient co-option and functional convergence with the non-homologous MC of Pseudomonadota.

A pilot study about the development and characterization of a Roux en Y gastric bypass model in obese Yucatan minipigs.

Performing the Roux-en-Y gastric bypass (RYGBP) in obese Yucatan minipigs provides an opportunity to explore the mechanisms behind the effects of this surgery in controlled environmental and nutritional conditions. We hypothesized that RYGBP in these minipigs would induce changes at multiple levels, as in obese humans. We sought to characterize RYGBP in a diet-induced obese minipig model, compared with a pair-fed sham group. After inducing obesity with an ad libitum high-fat/high-sugar diet, we performed RYGBP (n = 7) or sham surgery (n = 6). Oral glucose tolerance tests (OGTT) were performed before and after surgery. Histological analyses were conducted to compare the alimentary limb at sacrifice with tissue sampled during RYGBP surgery. One death occurred in the RYGBP group at postoperative day (POD) 3. Before sacrifice, weight loss was the same across groups. GLP-1 secretion (OGTT) was significantly higher at 15, 30 and 60 min at POD 7, and at 30 and 60 min at POD 30 in the RYGBP group. Incremental insulin area under the curve increased significantly after RYGBP (p = 0.02). RYGBP induced extensive remodeling of the alimentary limb. Results show that RYGBP can be safely performed in obese minipigs, and changes mimic those observed in humans.

Ion channels as convergence points in the pathology of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a fatal disease of the cardiopulmonary system that lacks curative treatments. The main pathological event in PAH is elevated vascular resistance in the pulmonary circulation, caused by abnormal vasoconstriction and vascular remodelling. Ion channels are key determinants of vascular smooth muscle tone and homeostasis, and four PAH channelopathies (KCNK3, ABCC8, KCNA5, TRPC6) have been identified so far. However, the contribution of ion channels in other forms of PAH, which account for the majority of PAH patients, has been less well characterised. Here we reason that a variety of triggers of PAH (e.g. BMPR2 mutations, hypoxia, anorectic drugs) that impact channel function may contribute to the onset of the disease. We review the molecular mechanisms by which these 'extrinsic' factors converge on ion channels and provoke their dysregulation to promote the development of PAH. Ion channels of the pulmonary vasculature are therefore promising therapeutic targets because of the modulation they provide to both vasomotor tone and proliferation of arterial smooth muscle cells.

Six-month outcomes of teduglutide treatment in adult patients with short bowel syndrome with chronic intestinal failure: A real-world French observational cohort study.

BACKGROUND & AIMS: Teduglutide, a GLP-2-analog, has proven effective in two placebo-controlled studies in reducing parenteral support (PS) in patients with short bowel syndrome-associated intestinal failure (SBS-IF) after 24 weeks. The aim of this study was to describe in a real-life situation the effects of teduglutide treatment and their predictive factors. METHODS: We included 54 consecutive SBS-IF patients treated with teduglutide in France for at least 6 months from 10 expert centers. Small bowel length was 62 ± 6 cm and 65% had colon in continuity. PS was 4.4 ±0 .2 infusions per week, started 9.8 ± 1.2 years before. Response (PS reduction ≥ 20%) and PS discontinuation rates were assessed at week 24. Adjusted p values of factors associated with response and weaning were calculated using a multivariate logistic regression model. RESULTS: At week 24, 85% of patients were responders and 24% had been weaned off PS, with a 51% reduction of PS needs and 1.5 ± 0.2 days off PS per week. Response to teduglutide was influenced by a higher baseline oral intake (p = 0.02). Weaning off PS was influenced by the presence of colon (p = 0.04), a lower PS volume (p = 0.03) and a higher oral intake (p = 0.01). There were no differences based on age, bowel length or SBS-IF causes. CONCLUSIONS: Our study confirms the effectiveness of teduglutide in reducing PS needs in SBS-IF patients. We associated reduced parenteral support volume with baseline parenteral volume support, bowel anatomy, and oral intake. These findings underline the role of nutritional optimization when starting the treatment.

[Assessment of nutritional status and body composition in patients with COPD: comparison of several methods]. / Evaluation de l'état nutritionnel et de la composition corporelle du patient BPCO: comparaison de plusieurs méthodes.

INTRODUCTION: In chronic obstructive pulmonary disease (COPD), loss of fat-free mass (FFM) reduces the prognosis. METHODS: To assess their nutritional status and compare the relevance of several nutritional criteria, 47 COPD patients, already enrolled in our pulmonary rehabilitation programme, were evaluated. Assessment of nutritional status included anthropometry, serum albumin and transthyretin, bioimpedance analysis (BIA) and 3-day dietary record. The accuracy of these nutritional parameters was determined by comparison with FFM measured by BIA. The agreement between BIA and the 4-skinfold-thickness method was determined by statistical correlation and the Bland and Altman method. Energy intake, health care requirements and quality of life (QOL) score were compared with the FFM. RESULTS: According to the criteria used, the prevalence of undernutrition varied between 4 and 49%. In comparison with BIA, body mass index (BMI) below 20, triceps skinfold below the 5th percentile and transthyretin below 0.20 g/L had a specificity of around 100% for the diagnosis of undernutrition. There was a good agreement between BIA and the 4-skinfold-thickness method for the assessment of FFM (r=0.86, P<0.0001). Prior to any nutritional intervention, the patients with low FFM had higher protein-energy intake than patients with normal FFM. Low FFM was associated with a greater number of visits to the doctor, but had no impact on QOL. CONCLUSION: The assessment of FFM by BIA is the most sensitive method to detect undernutrition in COPD patients. Lowered values of BMI, triceps skinfold and transthyretin are predictive of loss of FFM.

Antireflux surgery for non-erosive and erosive reflux disease in community practice.

BACKGROUND: Antireflux surgery has been mainly evaluated in tertiary referral centres. Data regarding post-operative outcome in non-erosive reflux disease are lacking. AIM: To assess long-term outcome after antireflux surgery performed in a community practice setting. METHODS: We selected consecutively 60 non-erosive reflux disease patients and 61 erosive oesophagitis patients with symptomatic gastro-oesophageal reflux disease. After surgery, each subject answered a validated disease-specific health-related quality of life questionnaire and another questionnaire focusing on symptoms, late morbidity and drug use. RESULTS: After a 43-month median follow-up, an excellent outcome was reported by less than two-thirds of patients. Quality of life scores were lower in the non-erosive reflux disease group, especially in female patients. Non-erosive reflux disease patients reported more daily symptoms and more reflux-related symptoms (P = 0.04). Proton-pump inhibitor use was higher in non-erosive reflux disease patients (P < 0.005). Multivariate analysis identified four independent predictive factors associated with better outcome, namely male gender, abnormal preoperative acid exposure, a long duration of symptoms and surgical expertise. CONCLUSIONS: In community practice, the results of antireflux surgery are inferior to those reported by tertiary centres. Outcome seems poorer in non-erosive reflux disease especially in female patients. Nearly one-third of the non-erosive reflux disease patients continue to take proton-pump inhibitors. These results highlight the need for careful selection of patients before antireflux surgery.

Simultaneous recordings of oesophageal acid exposure with conventional pH monitoring and a wireless system (Bravo).

OBJECTIVES: Oesophageal pH monitoring is a useful test for the diagnosis of gastro-oesophageal reflux disease (GORD) but has some limitations related to the nasopharyngeal electrode. Recently, a telemetric catheter free system (CFS) (Bravo; Medtronic) was developed. The aim of this study was to determine the concordance of data between the conventional pH measurement system (CPHMS) and the CFS Bravo. METHODS: Forty patients with symptoms suggestive of GORD underwent 24 hour oesophageal pH monitoring using the CPHMS with a nasopharyngeal electrode and the Bravo CFS simultaneously. The sensitive tips of both electrodes were positioned at the same level under fluoroscopy. In addition to automatic analysis, each reflux episode was checked visually and characterised. RESULTS: There was a significant correlation (r = 0.87, p < 0.0001) between the 24 hour oesophageal acid exposures recorded by the CPHMS and the CFS. Twenty four hour oesophageal acid exposure was significantly lower with the CFS than with the CPHMS (2.4 (0.4-8.7) v 3.6 (0.7-8.6); p < 0.0001). Consequently, with the CFS, the cut off level for the diagnosis of GORD, as calculated from the regression equation, was 2.9% (for the 4.2% cut off determined in controls with the CPHMS). After this adjustment, concordance of the diagnosis of GORD was 88% (kappa 0.760). Diagnosis of GORD was established in more patients with the CFS 48 hour results than with the 24 hour results. CONCLUSIONS: Despite strong correlations between oesophageal acid exposure recorded with the two devices, the Bravo CFS significantly under recorded acid exposure compared with the CPHMS. Provided some correcting factors are used, the Bravo CFS can improve the sensitivity of pHmetry for the diagnosis of GORD by allowing more prolonged recordings.

Efficacy and pharmacokinetics of intravenous immune globulin administration to high-risk neonates.

UNLABELLED: OBJECTIVE--To determine whether intravenous immune globulin (IVIG) administration modifies the incidence of infections in high-risk neonates. DESIGN--Randomized, double-blind study. SETTING--Neonatal intensive care unit at a tertiary care center. PARTICIPANTS: A total of 170 infants were enrolled, 82 of whom received IVIG and 88 of whom received the placebo preparation. Infants were stratified by birth weight into one of three groups (category 1, those weighing less than 1000 g; category 2, those weighing between 1000 and 1500 g; and category 3, those weighing more than 1500 g). INTERVENTIONS--Intravenous immune globulin (750 mg/kg of body weight), or albumin placebo was administered within 72 hours of admission to the tertiary care center and every 14 days thereafter until discharge from the neonatal intensive care unit or age 3 months. Serum IgG levels were measured and data collected relating to the incidence of systemic and localized infections and to the course of hospitalization. MEASUREMENTS AND MAIN RESULTS--The administration of IVIG had no major side effects and resulted in higher serum IgG levels in infants in all birth weight categories compared with infants receiving the placebo. Systemic infections developed in five IVIG-treated infants and five placebo-treated infants. Administration of immunoglobulin had no significant effect on the rate of localized infections or necrotizing enterocolitis. It also did not affect hospital course of the infants as measured by length of hospitalization or the number of days on assisted ventilation, supplemental oxygen, or antibiotics was required. CONCLUSIONS--The general administration of IVIG using this dosage regimen has limited effects on the clinical course of infants in a neonatal intensive care unit.

Local toxicity with subcutaneous methadone. Experience of two centers.

We report on 8 patients treated with subcutaneous methadone for cancer-related pain at 2 institutions. The success of other subcutaneous agents for pain control has been well demonstrated. It was felt that methadone would be useful due to its low cost. Unfortunately, 7 of the 8 patients experienced adverse reactions at the subcutaneous sites requiring cessation of subcutaneous methadone.

In vitro remodelling of plasma lipoproteins in whole plasma by lipoprotein lipase in primary and secondary hypertriglyceridaemia.

In patients with familial lipoprotein lipase deficiency (FLPL-d) and glycogen storage disease type I (GSD-I), hypertriglyceridaemia (1445 +/- 247 and 1082 +/- 312 mg dl-1, n = 5 per group) was associated primarily with reduced extrahepatic lipoprotein lipase (LPL) activity (0.33 +/- 0.33 and 1.69 +/- 0.38 mumol FFA ml-1 h-1) when compared with controls (4.83 +/- 0.90). Hypercholesterolaemia was characterized by elevated LDL cholesterol (191 +/- 30 and 344 +/- 34 vs. 115 +/- 5 mg dl-1 in controls P less than 0.01) and low HDL cholesterol (12 +/- 2 and 22 +/- 2 vs. 56 +/- 3 in controls, P less than 0.001). In order to ascertain the role of LPL in the interconversion and remodelling of lipoproteins in these disorders, we analysed lipid and lipoprotein profiles before and following in vitro incubation of patient plasma with purified milk LPL (EC 3.1.1.34) for 6 h at 37 degrees C. The efficiency of exogenous LPL in vitro was demonstrated by the extent of hydrolysis of chylomicrons and of VLDL-TG in both groups. Concomitant with the disappearance of TG-rich lipoprotein particles, a consistent per cent increment of IDL (99.2 +/- 30.8 and 43.9 +/- 70.5), LDL (152.8 +/- 36.2 and 137.0 +/- 36.1) and of HDL2 (144.8 +/- 29.4 and 99.8 +/- 18.7) was observed in both groups of patients. The enhancement of the latter fractions contrasted with the decline of HDL3 mass concentration (25.4 +/- 7.7 and 51.4 +/- 5.8%), suggesting that a major shift of HDL3----HDL2 occurs following in vitro lipolysis by LDL. Simultaneous compositional and morphological changes of individual lipoprotein particles were noted, confirming the dynamic movement and exchange of neutral lipids and proteins. Specificity of LPL results was demonstrated by experiments in which incubation of the whole plasma at 37 degrees C without exogenous lipolytic enzyme did not cause any substantial changes. The present study, therefore, demonstrates a correction of the major lipoprotein abnormalities associated with FLPL-d and GSD-I by exogenous LPL. No substantial difference was noted between primary (FLPL-d) and secondary (GSD-I) hyperlipidaemias. These studies allow us to conclude that a simple in vitro system, utilizing an exogenous source of LPL and plasma from patients, may serve as a suitable model for the study of the metabolic relationships of lipoproteins. However, in view of the fact that the extent of lipolysis achieved in vitro did not differ between FLPL-d and GSD-I, it may not be able to separate primary from secondary hyperlipaemias.

An unusual autoerotic death: asphyxia with an abdominal ligature.

A case of accidental death resulting from an autoerotic episode involving a high abdominal ligature is reported. Pathologic findings, physical evidence, and the psychological investigation are discussed.

The genesis of bowel sounds: influence of viscus and gastrointestinal content.

This study was undertaken to try to solve the controversy about the influence of gastrointestinal contents on the genesis of bowel sounds, and to probe the respective importance of the various abdominal viscera. Eleven healthy volunteers were intubated by mouth with a multiple-lumen tube. Bowel sounds were recorded for 10 min when the tube was in the stomach, the upper jejunum, and the cecum, while it was left intact in situ, or perfused with isotonic saline (15 ml per min), or with an equal (7.5 ml per min of each) mixture of isotonic saline and air. Using a previously developed method, a computer analysis was made of the recording without any human intervention during the treatment of data. An analysis of variance demonstrated that the effect of perfusion varied according to site, with 46% of counted sounds while the tube was in the stomach, 32% in the jejunum, and 22% in the colon (P less than 0.05). There were two types of sounds: some exceeded in amplitude a preset threshold, and thus were picked up by the computer, but their average absolute value for 20 msec remained inferior to another preset threshold. Their number was kept in memory (NS--sounds having an amplitude exceeding a threshold S1, expressed in number per 10 min). A second type of sounds also exceeded the present threshold but their average absolute value for 20 msec also exceeded another preset threshold. Their number (NE--sounds having an amplitude exceeding the thershold S1 but having also a 20-msec average amplitude above another threshold S2, expressed in number per 10 min) was also memorized. The latter group was composed of two types of sounds: some had a limited spectrum of low frequency (100 Hz) and were of high amplitude and short (congruent to 5 msec) duration (NE1); some others had a higher and more dispersed frequency centered around 300 Hz (NE2). Fifty per cent of high energy (NE) sounds appeared while the tube was in the stomach, 30% in the colon, and 20% in the jejunum (P less than 0.005). Short and high amplitude sounds (NE1) were counted more often (43%) when it was in the colon than in the stomach (38%) and the jejunum (19%) (P less than 0.025), and this was confirmed (P less than 0.005) by a study of the ratio of NE1/NE. On the contrary, higher frequency sounds (NE2) were present more often when the tube was in the stomach (59%) than in the jejunum (24%) and in the colon (17%) (P less than 0.005). There was no influence of the presence of the unperfused tube on the genesis of bowel sounds in different sites (P greater than 0.05). In the stomach and the colon perfusion of the air/saline mixture increased the number of sounds (P less than 0.025) and all types of sounds in the stomach (P less than 0.025), whereas in the jejunum it was the perfusion of saline which increased them (P less than 0.025). It is concluded that the stomach is the most active site of production of bowel sounds, followed by the colon and then the small bowel, that sounds differ in different sites, and that all this is influenced by viscus content.