A44 NOVEL AND HIGHLY SENSITIVE FLOW CYTOMETRIC BASED METHOD FOR CONTINUOUS TRACKING OF INTESTINAL PERMEABILTIY

Background

Inflammatory bowel diseases (IBD) are chronic, inflammatory conditions of the intestinal tract. In addition to a complex mixture of genetic, and environmental factors, increased intestinal permeability is also thought to be involved. Despite its diagnostic importance, there is no reliable yet minimally invasive way to measure intestinal permeability in patients and animal models. Currently, most assays involve the detection of orally given sugar molecules in either the urine (MLR method) or the plasma (FITC-dextran). These methods offer only limited accuracy, and do not allow continual tracking of intestinal permeability within the same animal due to the requirement of euthanization. Herein, we describe a novel cytometric-based method using an ingested dietary protein (ovalbumin (OVA)) and flow cytometry. We show our method is reliable, highly sensitive, minimally invasive and allows for the continuous tracking of intestinal permeability within the same individual using small blood volumes.

Aims

To compare the utility of our bead-based method of intestinal permeability measurement to the FITC-Dextran method.

Methods

Wildtype (WT) C57BL/6 mice, and mucin 2-deficient (Muc2-/-) mice (known to suffer a leaky gut) at baseline, or mice given chemical or infection-induced colitis were gavaged with a solution containing OVA protein and FITC-Dextran. After 6 hours, mice were euthanized to collect plasma for spectrophotometry (FITC-Dextran), or for flow cytometry (bead-based ELISA) analyses.

Results

We found that both OVA and FITC-dextran were detectable in plasma samples of the Muc2-/- mice, but not the WT mice, 6 hours after oral co-administration, however the bead-based method produced more consistent readings. Immunostaining of tissue sections with the same antibodies also showed that OVA can readily diffuse through the gut epithelium of Muc2-/- mice but not the WT mice, validating the specificity of the antibodies. We also tested our assay on WT mice undergoing dextran sodium sulfate (DSS) colitis, or infected with Citrobacter rodentium. We found that our method could detect statically significant changes in intestinal permeability 2 to 3 days earlier than the FITC-dextran method, while providing greatly reduced variability between technical repeats. More importantly, we were able to use a small volume (5 μL) of whole blood collected via tail poke, to measure intestinal permeability without requiring euthanization of the mice. This allowed the continuous tracking of permeability changes within the same animal.

Conclusions

We conclude that the bead-based method is more sensitive and reliable than the FITC-Dextran method as tested in several murine colitis models. More importantly, we showed that the bead-based method allows continual tracking of intestinal permeability within the same animal, enabling time course measurements.

Funding Agencies

CAG, CCC, CIHR, NRCBC Children’s Research Institute

[Clinical application effects of portable visual retractor in superficial temporal fascia flap harvesting]

Objective: To explore the clinical application effects of portable visual retractor in superficial temporal fascia flap harvesting. Methods: From January 2010 to June 2019, 27 patients meeting the inclusion criteria and planning to perform operation of superficial temporal fascia flap harvesting were admitted to the Department of Plastic and Reconstructive Surgery of the First Clinical Medical Center of the People's Liberation Army General Hospital. The patients were divided into traditional surgical method group [6 males and 3 females, aged (34±14) years], cold light source retractor group [6 males and 4 females, aged (35±16) years], and portable visual retractor group [7 males and 1 female, aged (30±14) years] according to way of superficial temporal fascia flap harvesting. The superficial temporal fascia flaps of patients in traditional surgical method group were resected by traditional way of resection, and the superficial temporal fascia flaps of patients in cold light source retractor group and portable visual retractor group were resected at assistance of cold light source retractor and portable visual retractor, respectively. Length of incision, operation time, intraoperative blood loss volume, postoperative drainage volume, and postoperative complication of patients in 3 groups were observed and recorded. Data were processed with Fisher's exact probability test, one-way analysis of variance, least significant difference test, Kruskal-Wallis H test, and Bonferroni correction. Results: The length of incision of patients in visual retractor group was (3.6±0.8) cm, significantly shorter than (12.6±1.6) cm in traditional surgical method group and (5.8±0.9) cm in cold light source retractor group (P<0.05). The incision length of patients in traditional surgical method group was significantly longer than that in cold light source retractor group (P<0.05). The operation time of patients in visual retractor group was 24.0 (23.3, 25.8) min, significantly shorter than 35.0 (30.5, 36.5) min in traditional surgical method group and 28.5 (26.8, 30.5) min in cold light source retractor group (H=16.5, 9.8, P<0.05). The operation time of patients in traditional surgical method group was significantly longer than that in cold light source retractor group (H=6.6, P<0.05). The intraoperative blood loss volume was (26±3) mL of patients in visual retractor group, significantly less than (34±4) mL in traditional surgical method group and (30±6) mL in cold light source retractor group (P<0.05). The intraoperative blood loss volume of patients in traditional surgical method group was significantly more than that in cold light source retractor group (P<0.05). The postoperative drainage volumes of patients in visual retractor group, cold light source retractor group, and traditional surgical method group were (33±4), (34±6), and (31±7) mL, respectively, and there were no significantly statistical differences in postoperative drainage volumes among patients in the three groups (F=0.3, P>0.05). There were no severe complications such as ischemia and necrosis of superficial temporal fascia flaps in patients of the three groups. One patient in cold light source retractor group had subcutaneous hematoma after operation, which was improved by removing stitches and hematoma. Conclusions: Superficial temporal fascia flap harvesting at the assistance of portable visual retractor has the advantages of clear visual field, simple operation, short operation time, small incision, and less intraoperative blood loss.

Effect of 6% hydroxyethyl starch 130/0.4 on kidney and haemostatic function in cardiac surgical patients: a randomised controlled trial

Whether third‐generation hydroxyethyl starch solutions provoke kidney injury or haemostatic abnormalities in patients having cardiac surgery remains unclear. We tested the hypotheses that intra‐operative administration of a third‐generation starch does not worsen postoperative kidney function or haemostasis in cardiac surgical patients compared with human albumin 5%. This triple‐blind, non‐inferiority, clinical trial randomly allocated patients aged 40–85 who underwent elective aortic valve replacement, with or without coronary artery bypass grafting, to plasma volume replacement with 6% starch 130/0.4 vs. 5% human albumin. Our primary outcome was postoperative urinary neutrophil gelatinase‐associated lipocalin concentrations, a sensitive and early marker of postoperative kidney injury. Secondarily, we evaluated urinary interleukin‐18; acute kidney injury using creatinine RIFLE criteria, coagulation measures, platelet count and function. Non‐inferiority (delta 15%) was assessed with correction for multiple comparisons. We enrolled 141 patients (69 starch, 72 albumin) as planned. Results of the primary analysis demonstrated that postoperative urine neutrophil gelatinase‐associated lipocalin (median (IQR [range])) was slightly lower with hydroxyethyl starch (5 (1–68 [0–996]) ng.ml⁻¹) vs. albumin (5 (2–74 [0–1604]) ng.ml⁻¹), although not non‐inferior [ratio of geometric means (95%CI) 0.91 (0.57, 1.44); p = 0.15] due to higher than expected variability. Urine interleukin‐18 concentrations were reduced, but interleukin‐18 and kidney injury were again not non‐inferior. Of 11 individual coagulation measures, platelet count and function, nine were non‐inferior to albumin. Two remaining measures, thromboelastographic R value and arachidonic acid‐induced platelet aggregation, were clinically similar but with wide confidence intervals. Starch administration during cardiac surgery produced similar observed effects on postoperative kidney function, coagulation, platelet count and platelet function compared with albumin, though greater than expected variability and wide confidence intervals precluded the conclusion of non‐inferiority. Long‐term mortality and kidney function appeared similar between starch and albumin.

[Guidelines for the use of post-traumatic tetanus vaccines and passive immune preparation]

Post-traumatic tetanus is the main type of non-neonatal tetanus. To reduce the incidence and mortality rate of tetanus and guide the primary medical institutions to prevent and control tetanus after trauma, National Immunization Planning Technical Working Group of the Chinese Center for Disease Control and Prevention has compiled this document in the reference with Position Paper by World Health Organization, the latest research progress from home and abroad. The guidelines focus on the basic procedures for the prevention and disposition of post-traumatic tetanus, the application of tetanus vaccines and immune preparation, and the pre-exposure immunization in high-risk populations of trauma.

[Vaccine loss related to the expanded immunization program in Xinjiang Uygur Autonomous Region, 2016-2017]

Objective: To assess the vaccine loss related to the Expanded Program on Immunization (EPI) in Xinjiang Uygur Autonomous Region so as to improve the management of vaccines. Methods: A total of 135 vaccination clinics were randomly selected, using a stratified cluster sampling method. In each clinic, data on vaccination was collected between 2016 and 2017, including the number of doses in routine immunization program and supplementary immunization activities (i.e., vaccine doses in vials that were opened for use) on polio vaccine, number of doses administered to children and the number of doses discarded (e.g., expired vaccine or broken vials that had not been opened for use), etc. Coefficient on vaccine loss was calculated with the following equation: vaccine loss coefficient=(number of vaccine doses used)/(number of vaccine doses administered). The vaccine discard rate appeared as: number of vaccine doses discarded)/number of vaccine doses used. Results: For vaccines in single-dose vials [diphtheria-tetanus-pertussis vaccine (DTaP) and trivalent oral polio virus vaccine (tOPV)], the loss coefficients appeared as 1.00 and 1.02, respectively. For vaccines in multi-dose vials [bivalent oral polio vaccine (bOPV), group A meningococcal polysaccharide vaccine (MPV-A), diphtheria-tetanus combined vaccine (DT) and bacilli Calmette-Guérin (BCG) vaccine], the loss coefficients were 1.58, 1.67, 1.68, and 3.02, respectively. The coefficients of EPI vaccine loss in urban, rural, and pastoral area vaccination clinics ranged between 1.00-2.84, 1.00-3.71, and 1.00-2.27, respectively. Loss coefficients ranged between 1.00-3.00, 1.00- 4.41, and 1.00-1.94, respectively, were seen in township clinics, village clinics, and decentralized vaccination clinics. Coefficients on larger vaccine loss were associated with longer intervals between clinic sessions and with fewer vaccinations administrations per day. Conclusions: In Xinjiang, coefficients on the loss of multi-dose EPI vaccines were high. The coefficients on loss were different from the levels of region and types of clinics, and time interval between clinic sessions. Programs on refining the management and distribution of EPI vaccines, to minimize the vaccine loss were recommended.

Reduction in surgical stoma rates in Crohn's disease: a population-based time trend analysis

AIM

Trends in surgical rates for Crohn's disease (CD) in the biological era are controversial. We aim to assess modern trends in the formation rates of surgical stomas.

METHOD

Population-based surveillance in the Calgary Health Zone (CHZ), Canada, was conducted between 1 April 2002 and 31 March 2011, using the Discharge Abstract Database to identify adult patients with CD admitted to hospital and treated with surgical stoma formation (n = 545). Annual stoma incidence was calculated by dividing the number of incident stomas by the prevalence of CD in the CHZ. Time trend analysis of the stoma-formation rate was performed, expressed as annual percentage change (APC) with 95% CI. Stoma-formation rates were stratified according to procedure (emergency vs elective) and duration of stoma [temporary (reversed within 2 years of formation) vs permanent].

RESULTS

The overall rate of stoma formation between 2002 and 2011 showed a downwards trend, of a mean of 5.2% (95% CI: -8.5 to -1.8) per year, from a rate of 2.30 stomas/100 person-years (PY) in 2002 to 1.51 stomas/100 PY in 2011. The rate of emergency stoma formation decreased significantly from 2002 to 2011 (mean APC = -9.4%; 95% CI: -15.6 to -2.8), while the rate of elective ostomies essentially showed no change (mean APC = -0.9%; 95% CI: -5.3 to 3.8). The rate of temporary stoma formation decreased significantly, by 4.6% (95% CI: -7.3 to -1.8) per year, while permanent stoma formation was stable (APC = 1.0%; 95% CI: -4.0 to +6.3).

CONCLUSION

A reduction in the overall rate of stoma formation in CD has been driven by fewer emergency stomas, although rates of permanent stoma have remained stable.

MR-based cardiac and respiratory motion correction of PET: application to static and dynamic cardiac 18F-FDG imaging

Motion of the myocardium deteriorates the quality and quantitative accuracy of cardiac PET images. We present a method for MR-based cardiac and respiratory motion correction of cardiac PET data and evaluate its impact on estimation of activity and kinetic parameters in human subjects. Three healthy subjects underwent simultaneous dynamic ¹⁸F-FDG PET and MRI on a hybrid PET/MR scanner. A cardiorespiratory motion field was determined for each subject using navigator, tagging and golden-angle radial MR acquisitions. Acquired coincidence events were binned into cardiac and respiratory phases using electrocardiogram and list mode-driven signals, respectively. Dynamic PET images were reconstructed with MR-based motion correction (MC) and without motion correction (NMC). Parametric images of ¹⁸F-FDG consumption rates (K_i) were estimated using Patlak's method for both MC and NMC images. MC alleviated motion artifacts in PET images, resulting in improved spatial resolution, improved recovery of activity in the myocardium wall and reduced spillover from the myocardium to the left ventricle cavity. Significantly higher myocardium contrast-to-noise ratio and lower apparent wall thickness were obtained in MC versus NMC images. Likewise, parametric images of K_i calculated with MC data had improved spatial resolution as compared to those obtained with NMC. Consistent with an increase in reconstructed activity concentration in the frames used during kinetic analyses, MC led to the estimation of higher K_i values almost everywhere in the myocardium, with up to 18% increase (mean across subjects) in the septum as compared to NMC. This study shows that MR-based motion correction of cardiac PET results in improved image quality that can benefit both static and dynamic studies.

Limited effects of the comprehensive pricing healthcare reform in China

OBJECTIVES

To evaluate the effects of China's very recent comprehensive pricing healthcare reform, taking the patients' perspective.

STUDY DESIGN

Two survey studies were conducted using the same protocol in Beijing in July 2017 and 2018, respectively.

METHODS

The same questionnaire was used and contains two sections, with the first on demographic and personal information and the second on various assessments of the reform.

RESULTS

Findings different from those in the government-led evaluations were made. Specifically, the majority of the patients thought the level of medical service fee and cost of medicine still high, and experienced no change or an increase in overall medical cost. The overall assessment of the reform was not sufficiently positive. Multiple problems in healthcare were identified. Development from 2017 to 2018 was not significantly positive.

CONCLUSIONS

Patients' assessments of the reform were not as positive as those made in the government-led evaluations. In extending the reform to the whole country, the government and healthcare providers may need to further tune the reform to better serve the public.

Body mass index cut-off points for predicting chronic non-communicable disease should differ by gender and age group

OBJECTIVES

The objective of this study to determine whether body mass index (BMI) in different genders and age groups need different thresholds when predicting chronic non-communicable diseases (CNCDs).

STUDY DESIGN

This is a cross-sectional study.

METHODS

Data were obtained from the China Health and Nutrition Survey conducted in 2009. Sequential sample cluster analysis was used to group age according to BMI. Propensity score matching was used to eliminate the influence of age. Receiver operating characteristic curve based on gender and age group was used to evaluate the cut-off values and efficiency of BMI in each group.

RESULTS

A total of 8469 individuals were enrolled in this study. Results of sequential sample cluster analyses showed age was divided into three groups: 18-39, 40-59 and 60-99 years. There were significant differences in the distribution of BMI among the three groups for both males and females (P < 0.001). Statistical differences were observed in the distribution of BMI between genders in the 18-39- and 60-99-year-old age groups (P < 0.001). For men, the cut-off values of BMI were ≥25 kg/m², ≥24 kg/m² and ≥23 kg/m² in the 18-39, 40-59 and 60-99 years old groups, respectively; for women, the corresponding cut-off points were ≥25 kg/m², ≥23 kg/m² and ≥25 kg/m² in groups.

CONCLUSIONS

The thresholds for BMI might be different between gender and age group. In addition, it might not be suitable to determine cut-off values of BMI to predict CNCDs for people aged ≥60 years.

The molecular structure and imprinting status of the IPW (imprinted gene in the Prader-Willi syndrome region) gene in cattle

IPW (imprinted gene in the Prader-Willi syndrome region), a long non-coding RNA, is a paternally expressed gene in the PWS/AS imprinted domain on human chromosome 15 and mouse chromosome 7. Disruption of the PWS/AS region is associated with three neurogenic disorders in humans. In this study, we identified the bovine homolog of the IPW gene; multiple transcripts obtained by RT-PCR and RACE showed a complex and tissue-specific expression pattern of IPW in the brain, heart, kidney, liver, lung, spleen and skeletal muscle. An informative single nucleotide polymorphism (rs133341090) in the long exon H was identified by sequencing the genomic DNA, and mono-allelic expression of IPW was confirmed by sequencing the cDNAs of heterozygous individuals, indicating that IPW may be imprinted in cattle. The protein-coding potential of IPW transcripts was assessed using coding potential calculator (cpc) software, which showed a negative score. In addition, sequencing analysis also indicated multiple small open reading frames in the bovine IPW transcript, but none of the ATGs was consistent with Kozak consensus. Taken together, the IPW transcripts are most likely long non-coding RNAs.

Gut microbiota of newborn piglets with intrauterine growth restriction have lower diversity and different taxonomic abundances

Aim

Intrauterine growth retardation (IUGR) is a prevalent problem in mammals. The present study was conducted to unveil the alterations in intestinal microbiota in IUGR piglets.

Methods and Results

We identified the alterations of small intestinal microbiota in IUGR piglets on 7, 21 and 28 days of age using 16S rRNA sequencing. The results showed that IUGR piglets had a decreased alpha diversity of jejunum microbiota at 7 and 21 days of age; had lower abundances of Bacteroidetes and Bacteroides in the jejunum at 7, 21 and 28 days of age, Oscillibacter in the jejunum at 21 days of age, and Firmicutes in the ileum at 21 days of age; whereas they had higher abundances of Proteobacteria and Pasteurella in the ileum at 21 days of age and Escherichia–Shigella in the jejunum at 28 days of age. Correlation analysis showed that Bacteroides, Oscillibacter and Ruminococcaceae_UCG‐002 compositions were positively associated with the body weight (BW) of IUGR piglets, nevertheless Proteobacteria and Escherichia–Shigella relative abundances were negatively correlated with the BW of IUGR piglets. Gene function prediction analysis indicated that microbiota‐associated carbohydrate metabolism, lipid metabolism, glycan biosynthesis and metabolism, amino acid metabolism, and xenobiotics biodegradation and metabolism were downregulated in the IUGR piglets compared to control piglets.

Conclusions

The present study profiled the intestinal microbiota of newborn piglets with IUGR and the newborn IUGR piglets have lower diversity and different taxonomic abundances. Alterations in the abundances of Bacteroidetes, Bacteroides, Proteobacteria Escherichia–Shigella and Pasteurella may be involved in nutrient digestion and absorption, as well as the potential mechanisms connecting to the growth and development of IUGR in mammals.

Significance and Impact of the Study

The small intestinal microbiota were highly shaped in the IUGR piglets, which might further mediate the growth and development of IUGR piglets; and the gut microbiota could serve as a potential target for IUGR treatment.

MicroRNA-24 attenuates vascular remodeling in diabetic rats through PI3K/Akt signaling pathway

BACKGROUND AND AIMS

The vascular remodeling plays a crucial role in pathogenesis of diabetic cardiovascular complications. In this study, we intended to explore the effects and potential mechanisms of microRNA-24 (miR-24) on vascular remodeling under diabetic conditions.

METHODS AND RESULTS

MiR-24 recombinant adenovirus (Ad-miR-24-GFP) was used to induce miR-24 overexpression either in carotid arteries or high glucose (HG)-induced vascular smooth muscle cells (VSMCs). Cell proliferation was analyzed using CCK-8 method. Cell migration was examined using wound-healing and transwell assay. mRNA and protein expressions of critical factors were, respectively, measured by real-time PCR and western blot as follows: qRT-PCR for the levels of miR-24, PIK3R1; western blot for the protein levels of PI3K (p85α), Akt, p-Akt, mTOR, p-mTOR, 4E-BP1, p-4E-BP1, p70s6k, p-p70s6k, MMP 2, MMP 9, collagen Ⅰ, as well as collagen Ⅲ. Carotid arteries in diabetic rats suffered balloon injury were harvested and examined by HE, immunohistochemical and Masson trichrome staining. The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, accompanied by increased mRNA expression of PIK3R1. The up-regulation of miR-24 suppressed VSMCs proliferation, migration, collagen deposition not only induced by HG in vitro, but also in balloon-injured diabetic rats, which were related to inactivation of PI3K/Akt signaling pathway.

CONCLUSION

The up-regulation of miR-24 significantly attenuated vascular remodeling both in balloon-injured diabetic rats and HG-stimulated VSMCs via suppression of proliferation, migration and collagen deposition by acting on PIK3R1 gene that modulated the PI3K/Akt/mTOR axes.

Maternal Immunoglobulin A protects against the development of necrotizing enterocolitis in preterm infants

Neonates are particularly susceptible to infection by colonizing microbes, and mammals protect their offspring via antibodies secreted into breast milk. Necrotizing Enterocolitis(NEC) is a disease of preterm infants characterized by intestinal epithelial damage and inflammation associated with the microbiota. The incidence of NEC is significantly lower in infants fed with maternal milk, though the mechanisms underlying this protective benefit are not clear. Here, we show that maternal Immunoglobulin A (IgA) is an important factor in protection against NEC. Analysis of IgA-binding within fecal samples from preterm infants indicated that breast milk was the predominant source of IgA in the first month of life and that a relative decrease in the fraction of bacteria bound by IgA is associated with the development of NEC. Sequencing of IgA-bound and unbound bacteria revealed that NEC was associated with increasing domination of the IgA unbound microbiota by Enterobacteriaceae, prior to disease onset. Further, we confirmed that IgA is critical in preventing NEC in a murine model, where we demonstrate that pups reared by IgA deficient mothers are susceptible to disease despite exposure to maternal milk. This study illustrates the importance of maternal IgA in shaping the host-microbiota relationship of preterm neonates and provides evidence that IgA is a critical factor in maternal milk necessary for the prevention of NEC.