Tight junction structure, function, and assessment in the critically ill: a systematic review.
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SUBMITTER: Vermette D
PROVIDER: S-EPMC6158145 | biostudies-literature | 2018 Sep
REPOSITORIES: biostudies-literature
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Project description:BACKGROUND:Hyperglycemia is prevalent in patients in the pediatric intensive care unit. The purpose of this study was to describe the benefits and risks of tight glucose control (TGC) in critically ill children. METHODS:A systemic review and meta-analysis of the literature was carried out on randomized controlled trials of TGC in critically ill children admitted to the pediatric intensive care unit. The databases searched were Medline, Embase, and CENTRAL databases until May 1, 2017. Paired reviewers independently screened citations, assessed risk of bias of included studies, and extracted data. A random-effects model was used to report all outcomes. The Grading of Recommendations Assessment, Development and Evaluation system was used to quantify absolute effects and quality of evidence. The primary outcome was hospital mortality. The secondary outcomes were hypoglycemia (any, severe), sepsis, new need for dialysis, and seizures. RESULTS:A total of 4030 patients were included from six studies. All six studies were rated as at low risk of bias. Our meta-analysis showed that TGC did not result in a decrease in risk of hospital mortality (odds ratio (OR), 0.95; 95% confidence interval (CI), 0.62-1.45; I2 = 40%; moderate quality), sepsis (OR, 0.82; 95% CI, 0.63-1.08), or seizures (OR, 0.98; 95% CI, 0.59-1.63). TGC was associated with a decrease in new need for dialysis (OR, 0.63; 95% CI, 0.45-0.86). However, TGC was associated with a significant increase in any hypoglycemia (OR, 4.39; 95% CI, 2.39-8.06) and severe hypoglycemia (OR, 4.11; 95% CI, 2.67-6.32). CONCLUSIONS:Among critically ill children with hyperglycemia, TGC does not result in a decrease in hospital mortality, but appears to reduce a new need for dialysis. However, TGC is associated with higher incidence of hypoglycemia. SYSTEMATIC REVIEW REGISTRATION:PROSPERO registration number CRD42017074039 .
| S-EPMC5835325 | biostudies-literature
Project description:BackgroundEarly assessment and management of patients with sepsis can significantly reduce its high mortality rates and improve patient outcomes and quality of life.ObjectivesThe purposes of this review are to: (1) explore nurses' knowledge, attitude, practice, and perceived barriers and facilitators related to early recognition and management of sepsis, (2) explore different interventions directed at nurses to improve sepsis management.MethodsA systematic review method according to the PRISMA guidelines was used. An electronic search was conducted in March 2021 on several databases using combinations of keywords. Two researchers independently selected and screened the articles according to the eligibility criteria.ResultsNurses reported an adequate of knowledge in certain areas of sepsis assessment and management in critically ill adult patients. Also, nurses' attitudes toward sepsis assessment and management were positive in general, but they reported some misconceptions regarding antibiotic use for patients with sepsis, and that sepsis was inevitable for critically ill adult patients. Furthermore, nurses reported they either were not well-prepared or confident enough to effectively recognize and promptly manage sepsis. Also, there are different kinds of nurses' perceived barriers and facilitators related to sepsis assessment and management: nurse, patient, physician, and system-related. There are different interventions directed at nurses to help in improving nurses' knowledge, attitudes, and practice of sepsis assessment and management. These interventions include education sessions, simulation, decision support or screening tools for sepsis, and evidence-based treatment protocols/guidelines.DiscussionOur findings could help hospital managers in developing continuous education and staff development training programs on assessing and managing sepsis in critical care patients.ConclusionNurses have poor to good knowledge, practices, and attitudes toward sepsis as well as report many barriers related to sepsis management in adult critically ill patients. Despite all education interventions, no study has collectively targeted critical care nurses' knowledge, attitudes, and practice of sepsis management.
| S-EPMC9249173 | biostudies-literature
Project description:BACKGROUND:In multicenter studies, tight glycemic control targeting a normal blood glucose level has not been shown to improve outcomes in critically ill adults or children after cardiac surgery. Studies involving critically ill children who have not undergone cardiac surgery are lacking. METHODS:In a 35-center trial, we randomly assigned critically ill children with confirmed hyperglycemia (excluding patients who had undergone cardiac surgery) to one of two ranges of glycemic control: 80 to 110 mg per deciliter (4.4 to 6.1 mmol per liter; lower-target group) or 150 to 180 mg per deciliter (8.3 to 10.0 mmol per liter; higher-target group). Clinicians were guided by continuous glucose monitoring and explicit methods for insulin adjustment. The primary outcome was the number of intensive care unit (ICU)-free days to day 28. RESULTS:The trial was stopped early, on the recommendation of the data and safety monitoring board, owing to a low likelihood of benefit and evidence of the possibility of harm. Of 713 patients, 360 were randomly assigned to the lower-target group and 353 to the higher-target group. In the intention-to-treat analysis, the median number of ICU-free days did not differ significantly between the lower-target group and the higher-target group (19.4 days [interquartile range {IQR}, 0 to 24.2] and 19.4 days [IQR, 6.7 to 23.9], respectively; P=0.58). In per-protocol analyses, the median time-weighted average glucose level was significantly lower in the lower-target group (109 mg per deciliter [IQR, 102 to 118]; 6.1 mmol per liter [IQR, 5.7 to 6.6]) than in the higher-target group (123 mg per deciliter [IQR, 108 to 142]; 6.8 mmol per liter [IQR, 6.0 to 7.9]; P<0.001). Patients in the lower-target group also had higher rates of health care-associated infections than those in the higher-target group (12 of 349 patients [3.4%] vs. 4 of 349 [1.1%], P=0.04), as well as higher rates of severe hypoglycemia, defined as a blood glucose level below 40 mg per deciliter (2.2 mmol per liter) (18 patients [5.2%] vs. 7 [2.0%], P=0.03). No significant differences were observed in mortality, severity of organ dysfunction, or the number of ventilator-free days. CONCLUSIONS:Critically ill children with hyperglycemia did not benefit from tight glycemic control targeted to a blood glucose level of 80 to 110 mg per deciliter, as compared with a level of 150 to 180 mg per deciliter. (Funded by the National Heart, Lung, and Blood Institute and others; HALF-PINT ClinicalTrials.gov number, NCT01565941 .).
| S-EPMC5444653 | biostudies-literature
Project description:The tight junction is an important subcellular organelle which plays a vital role in epithelial barrier function. Claudin, as the integral membrane component of tight junctions, creates a paracellular transport pathway for various ions to be reabsorbed by the kidneys. This review summarizes advances in claudin structure, function and pathophysiology in kidney diseases. Different claudin species confer selective paracellular permeability to each of three major renal tubular segments: the proximal tubule, the thick ascending limb of Henle's loop and the distal nephron. Defects in claudin function can cause a wide spectrum of kidney diseases, such as hypomagnesemia, hypercalciuria, kidney stones and hypertension. Studies using transgenic mouse models with claudin mutations have recapitulated several of these renal disease phenotypes and have elucidated the underlying biological mechanisms. Modern recording approaches based upon scanning ion conductance microscopy may resolve the biophysical nature of claudin transport function and provide novel insight into tight junction architecture.
| S-EPMC4214347 | biostudies-literature
Project description:The tight junction (TJ) is a structure composed of multiple proteins, both cytosolic and membranal, responsible for cell-cell adhesion in polarized endothelium and epithelium. The TJ is intimately connected to the cytoskeleton and plays a role in development and homeostasis. Among the TJ's membrane proteins, claudins (CLDNs) are key to establishing blood-tissue barriers that protect organismal physiology. Recently, several crystal structures have been reported for detergent extracted recombinant CLDNs. These structural advances lack direct evidence to support quaternary structure of CLDNs. In this article, we have employed protein-engineering principles to create detergent-independent chimeric CLDNs, a combination of a 4-helix bundle soluble monomeric protein (PDB ID: 2jua) and the apical-50% of human CLDN1, the extracellular domain that is responsible for cell-cell adhesion. Maltose-binding protein-fused chimeric CLDNs (MBP-CCs) used in this study are soluble proteins that retain structural and functional aspects of native CLDNs. Here, we report the biophysical characterization of the structure and function of MBP-CCs. MBP-fused epithelial cadherin (MBP-eCAD) is used as a control and point of comparison of a well-characterized cell-adhesion molecule. Our synthetic strategy may benefit other families of 4-α-helix membrane proteins, including tetraspanins, connexins, pannexins, innexins, and more.
| S-EPMC8124314 | biostudies-literature
Project description:ObjectiveTo describe the existing early mobilization protocols in pediatric intensive care units.MethodsA systematic literature review was performed using the databases MEDLINE®, Embase, SciELO, LILACS and PeDRO, without restrictions of date and language. Observational and randomized and nonrandomized clinical trials that described an early mobilization program in patients aged between 29 days and 18 years admitted to the pediatric intensive care unit were included. The methodological quality of the studies was evaluated using the Newcastle-Ottawa Scale, Methodological Index for Non-Randomized Studies and the Cochrane Collaboration.ResultsA total of 8,663 studies were identified, of which 6 were included in this review. Three studies described the implementation of an early mobilization program, including activities such as progressive passive mobilization, positioning, and discussion of mobilization goals with the team, in addition to contraindications and interruption criteria. Cycle ergometer and virtual reality games were also used as resources for mobilization. Four studies considered the importance of the participation of the multidisciplinary team in the implementation of early mobilization protocols.ConclusionIn general, early mobilization protocols are based on individualized interventions, depending on the child's development. In addition, the use of a cycle ergometer may be feasible and safe in this population. The implementation of institutional and multidisciplinary protocols may contribute to the use of early mobilization in pediatric intensive care units; however, studies demonstrating the efficacy of such intervention are needed.
| S-EPMC6649221 | biostudies-literature
Project description:PLEKHA7 is a recently identified protein of the epithelial zonula adhaerens (ZA), and is part of a protein complex that stabilizes the ZA, by linking it to microtubules. Since the ZA is important in the assembly and disassembly of tight junctions (TJ), we asked whether PLEKHA7 is involved in modulating epithelial TJ barrier function. We generated clonal MDCK cell lines in which one of four different constructs of PLEKHA7 was inducibly expressed. All constructs were localized at junctions, but constructs lacking the C-terminal region were also distributed diffusely in the cytoplasm. Inducible expression of PLEKHA7 constructs did not affect the expression and localization of TJ proteins, the steady-state value of transepithelial resistance (TER), the development of TER during the calcium switch, and the flux of large molecules across confluent monolayers. In contrast, expression of three out of four constructs resulted both in enhanced recruitment of E-cadherin and associated proteins at the apical ZA and at lateral puncta adherentia (PA), a decreased TER at 18 h after assembly at normal calcium, and an attenuation in the fall in TER after extracellular calcium removal. This latter effect was inhibited when cells were treated with nocodazole. Immunoprecipitation analysis showed that PLEKHA7 forms a complex with the cytoplasmic TJ proteins ZO-1 and cingulin, and this association does not depend on the integrity of microtubules. These results suggest that PLEKHA7 modulates the dynamics of assembly and disassembly of the TJ barrier, through E-cadherin protein complex- and microtubule-dependent mechanisms.
| S-EPMC4022608 | biostudies-literature
Project description:GOPC (FIG/PIST/CAL) is a PDZ-domain scaffolding protein that regulates the trafficking of a wide array of proteins, including small GTPases, receptors and cell surface molecules such as cadherin 23 and cystic fibrosis transmembrane regulator. In Madin-Darby canine kidney (MDCK) cells, we find that GOPC localizes to the trans-Golgi network (TGN) but not to the cis- or trans-Golgi cisternae. Colocalization occurs with the early endosome Rab GTPase Rab5 and a TGN/endosome marker Rab14 but not with Rab11, a marker of recycling endosomes. No localization of GOPC was detected to the lateral membranes or tight junctions. Knockdown of GOPC in MDCK cells results in decreased transepithelial resistance and increased paracellular flux. This might be attributable to the compromised trafficking of tight junction components from the TGN, as GOPC-knockdown cells have decreased lateral labeling of the tight junction protein claudin-1 and decreased protein levels of claudin-2. GOPC might mediate the trafficking of newly synthesized tight junction proteins from the TGN to the cell surface or the recycling of these proteins from specialized endosomal compartments.
| S-EPMC4414737 | biostudies-literature
Project description:BackgroundThe background of this study is to determine whether the addition of intravenous colloid to diuretic therapy, in comparison to diuretic therapy alone, improves diuresis and oxygenation and prevents intravascular volume depletion in intensive care unit (ICU) patients without shock.MethodsWe searched MEDLINE, Embase, Cochrane Register of Controlled Trials, Google Scholar, conference abstracts of ACCP, SCCM, ATS, and references of relevant articles. Randomized controlled trials (RCTs) of adult ICU patients, not in shock (defined as patients on low dose or no vasopressors, without need for IV fluid bolus or blood transfusion within 24 h), comparing intravenous colloid therapy (human albumin, plasma, synthetic starches, or gels) plus diuretic to control (diuretic alone, or diuretic plus placebo). Two reviewers independently applied eligibility criteria, assessed quality, and extracted data.ResultsSeven hundred fifty five studies were found in the initial search; 14 were deemed relevant; 2 were found to be eligible. There was good agreement between reviewers for study relevance (k?=?0.869) and eligibility (k?=?0.811). One study of heart failure patients showed no evidence of improved mean or hourly urine output in the group receiving albumin. The second studied patients hypoproteinemic with ARDS and demonstrated an improved fluid balance in 3 days, improved oxygenation status, and improved serum albumin level in patients treated with albumin. No significant differences were found for other outcomes. No studies evaluating colloids other than albumin were found.ConclusionsOur review is limited by the small number of high-quality RCTs available to study this clinical question, both of which only studied albumin. High-quality RCTs are required to evaluate the effect of albumin as well as other colloids as an adjunct to diuresis in a general ICU population.
| S-EPMC4424729 | biostudies-literature
Project description:IntroductionCritical illness is characterized by oxidative stress, which is a major promoter of systemic inflammation and organ failure due to excessive free radical production, depletion of antioxidant defenses, or both. We hypothesized that exogenous supplementation of trace elements and vitamins could restore antioxidant status, improving clinical outcomes.MethodsWe searched computerized databases, reference lists of pertinent articles and personal files from 1980 to 2011. We included randomized controlled trials (RCTs) conducted in critically ill adult patients that evaluated relevant clinical outcomes with antioxidant micronutrients (vitamins and trace elements) supplementation versus placebo.ResultsA total of 21 RCTs met inclusion criteria. When the results of these studies were statistically aggregated (n = 20), combined antioxidants were associated with a significant reduction in mortality (risk ratio (RR) = 0.82, 95% confidence interval (CI) 0.72 to 0.93, P = 0.002); a significant reduction in duration of mechanical ventilation (weighed mean difference in days = -0.67, 95% CI -1.22 to -0.13, P = 0.02); a trend towards a reduction in infections (RR= 0.88, 95% CI 0.76 to 1.02, P = 0.08); and no overall effect on ICU or hospital length of stay (LOS). Furthermore, antioxidants were associated with a significant reduction in overall mortality among patients with higher risk of death (>10% mortality in control group) (RR 0.79, 95% CI 0.68 to 0.92, P = 0.003) whereas there was no significant effect observed for trials of patients with a lower mortality in the control group (RR = 1.14, 95% 0.72 to 1.82, P = 0.57). Trials using more than 500 ?g per day of selenium showed a trend towards a lower mortality (RR = 0.80, 95% CI 0.63 to 1.02, P = 0.07) whereas trials using doses lower than 500 ?g had no effect on mortality (RR 0.94, 95% CI 0.67 to 1.33, P = 0.75).ConclusionsSupplementation with high dose trace elements and vitamins may improve outcomes of critically ill patients, particularly those at high risk of death.
| S-EPMC3681395 | biostudies-literature