[Synthesis and in vitro characterization of chitosan microspheres/ceramic bovine bone composite scaffold]

OBJECTIVE

The chitosan microspheres encapsulated with bone morphogenetic protein-2 (BMP-2) were prepared by the emulsion cross-linking method. Then the chitosan microspheres were loaded in the ceramic bovine bone (CBB) to achieve the drug delivery system.

METHODS

The chemical structure and surface morphology of the drug delivery system were investigated by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) observation. Characterization preserved the loading capacity and encapsulation efficiency of the BMP-2. The dynamic immersion method was used to examine the in vitro release characteristic of BMP-2.

RESULTS

The chitosan microspheres were successfully encapsulated BMP-2 by cross-linking method. The microspheres were micron-sized (5.982 μm) and spherical in shape with smooth surface morphology. From the release experiments, it was found that 5 mg chitosan/BMP-2 soaked for 21 days with a gradual release of BMP-2. The concentration of BMP-2 was (239.1±20.0) mg/L on Day 21. The in vitro experiment showed that this novel drug delivery system could accelerate MC3T3-E1 cells proliferation and osteogenic differentiation.

CONCLUSION

The drug delivery system achieves the biological function of BMP-2 and sustaining slow release in bone repair parts. Also it can provide the basis for repair of bone tissue defect treatment and the selection of bone tissue engineering scaffolds.

Effects of dietary supplementation with carnosine on meat quality and antioxidant capacity in broiler chickens

1. This study aimed to investigate the effects of carnosine supplementation on meat quality, antioxidant capacity and lipid peroxidation status in broiler chickens. 2. A total of 256 1-d-old male Arbor Acres broilers were randomly assigned to 4 treatments consisting of 8 replicates of 8 chickens each. The birds were supplied with 4 different diets: a basal diet or a basal diet supplemented with 100, 200 or 400 mg/kg carnosine, respectively. The whole experiment lasted 42 d. 3. The results showed that dietary supplementation with carnosine linearly increased the values of pH_45 min and redness and reduced drip loss of breast meat. Dietary carnosine increased the activity of antioxidant enzymes in liver, serum and breast meat and decreased the contents of lipid peroxides at 21 and 42 d of age. 4. These findings indicated that dietary supplementation with carnosine was beneficial to enhance meat quality, antioxidant capacity and decrease lipid peroxidation status of breast meat.

Hypoxia inducible factor-1α-induced interleukin-33 expression in intestinal epithelia contributes to mucosal homeostasis in inflammatory bowel disease

Intestinal epithelial cells (IECs), an important barrier to gut microbiota, are subject to low oxygen tension, particularly during intestinal inflammation. Hypoxia inducible factor-1α (HIF-1α) is expressed highly in the inflamed mucosa of inflammatory bowel disease (IBD) and functions as a key regulator in maintenance of intestinal homeostasis. However, how IEC-derived HIF-1α regulates intestinal immune responses in IBD is still not understood completely. We report here that the expression of HIF-1α and IL-33 was increased significantly in the inflamed mucosa of IBD patients as well as mice with colitis induced by dextran sulphate sodium (DSS). The levels of interleukin (IL)-33 were correlated positively with that of HIF-1α. A HIF-1α-interacting element was identified in the promoter region of IL-33, indicating that HIF-1α activity regulates IL-33 expression. Furthermore, tumour necrosis factor (TNF) facilitated the HIF-1α-dependent IL-33 expression in IEC. Our data thus demonstrate that HIF-1α-dependent IL-33 in IEC functions as a regulatory cytokine in inflamed mucosa of IBD, thereby regulating the intestinal inflammation and maintaining mucosal homeostasis.

Dynamic contrast-enhanced magnetic resonance angiography for the localization of spinal dural arteriovenous fistulas at 3T

OBJECTIVE

This study was undertaken to evaluate the accuracy of dynamic contrast-enhanced magnetic resonance angiography (DCE-MRA) in the precise location and demonstration of fistulous points in spinal dural arteriovenous fistulas (SDAVFs).

METHODS

Fifteen patients (14 men, 1 woman; age range: 40-78 years; mean: 55.5 years) harboring SDAVF who underwent preoperative DCE-MRA and spinal digital subtraction angiography (DSA) between January 2012 and January 2015 were evaluated retrospectively. Two reviewers independently evaluated the level and side of the arteriovenous fistula and feeding artery on 3T DCE-MRA and DSA images. The accuracy of DCE-MRA was assessed by comparing its findings with those from DSA and surgery in each case.

RESULTS

All 15 patients underwent DCE-MRA and DSA. DSA was unsuccessful in two patients due to technical difficulties. All cases were explored surgically, guided by the DCE-MRA. Surgery confirmed that 14 AVF sites were located in the thoracic spine, 5 in the lumbar spine, and 1 in the cervical spine. The origin of the fistulas and feeding arteries was accurately shown by DCE-MRA in 11 of the 15 patients. DCE-MRA also detected dilated perimedullary veins in all 15 patients. Overall, DCE-MRA facilitated DSA catheterization in 10 cases. In six patients, the artery of Adamkiewicz could be observed. In 15 out of 20 fistulas (75%), both readers agreed on the location on DCE-MRA images, and the κ coefficient of the interobserver agreement was 0.67 (95% confidence interval [CI], 0.16-0.87). In 13 of 16 shunts (75%), the DCE-MRA consensus findings and DSA findings coincided. The intermodality agreement was 0.77 (95% CI: 0.35-0.92).

CONCLUSIONS

Our DCE-MRA studies benefited from the use of a high-field 3T MR imaging unit and reliably detected and localized the SDAVF and feeding arteries. As experience with this technique grows, it may be possible to replace DSA with DCE-MRA if surgery is the planned treatment.

Emperipolesis is a potential histological hallmark associated with chronic hepatitis B

Although emperipolesis exists in infectious liver diseases, the diagnostic value of emperipolesis in chronic hepatitis B is not exactly known. The aim of this study is to evaluate the histological characteristics and laboratory parameters of emperipolesis in chronic hepatitis B. Totally 402 patients with hepatitis B and other liver diseases were processed in a retrospective assessment. Inflammatory severity of hepatitis B was evaluated with Ishak Scoring System. Immunofluorescent staining was performed for CD8 (T cells), CD20 (B cells), CD56 (NK cells), CD68 (macrophages) and MPO (neutrophils). Emperipolesis was observed in 74.0% of patients with chronic hepatitis B (CHB) and 82.8% of patients with acute hepatitis B (AHB). In emperipolesis, CD8(+) T cell was the main cell type. Patients with emperipolesis in CHB got high scores of inflammatory activity. Among patients with CHB, emperipolesis was present with higher serum ALT, AST and GGT levels. HBV DNA Load in patients with emperipolesis was as 10 times high as those without emperipolesis. HBeAb was significantly correlated with the evidence of emperipolesis. In chronic hepatitis B, emperipolesis was associated with severity of liver injury. The presence of emperipolesis was an indicator of active liver inflammation.

Hydrogen sulfide synthesis enzymes reduced in lower esophageal sphincter of patients with achalasia

The etiology of achalasia remains largely unknown. Considerable evidence reveals that the lower esophageal sphincter dysfunction is due to the lack of inhibitory neurotransmitter, secondary to esophageal neuronal inflammation or loss. Recent studies suggest hydrogen sulfide may act as an inhibitory transmitter in gastrointestinal tract, but study about hydrogen sulfide in human esophagus still lack. The aim of the study was to investigate if hydrogen sulfide synthesis enzymes could be detected in human esophagus and if the synthesis of the endogenous hydrogen sulfide could be affected in achalasia patients. Tissue samples in cardia, lower esophageal sphincter, 2 cm and 4 cm above lower esophageal sphincter were obtained from achalasia patients undergoing peroral endoscopic myotomy. Control tissues in lower esophageal sphincter were obtained from esophageal carcinoma patients. Expression of cystathionine-β-synthase and cystathionine-γ-lyase in lower esophageal sphincter of achalasia patients and control were detected by immunohistochemical staining. In addition, expression of cystathionine-β-synthase and cystathionine-γ-lyase were compared among different parts of esophagus in achalasia patients. Compared with control, the expression of cystathionine-β-synthase and cystathionine-γ-lyase in lower esophageal sphincter of achalasia patients was significantly reduced (χ² = 11.429, P = 0.010). The expression of cystathionine-β-synthase and cystathionine-γ-lyase were lower in lower esophageal sphincter than that in 2 cm and 4 cm above lower esophageal sphincter, respectively (all P < 0.05). In conclusion, the expression of hydrogen sulfide synthesis enzymes, cystathionine-β-synthase and cystathionine-γ-lyase, can be detected in human esophagus and is reduced in patients with achalasia, which implicates the involvement of the two hydrogen sulfide synthesis enzymes in the pathophysiology of achalasia.

First case of hepatopancreatic necrosis disease in pond-reared Chinese mitten crab, Eriocheir sinensis, associated with microsporidian

An epidemic of hepatopancreatic necrosis disease (HPND) with a high mortality rate (40%-50%) recently occurred in the cultured Chinese mitten crab, Eriocheir sinensis, which is a very important economic crustacean species in China. Histology revealed infection by a microsporidian parasite within the cytoplasm of the epithelial cells of the hepatopancreas. Numerous discrete inclusions in the infected cells and presumably free parasite spores were also observed. By negative staining using electron microscopy, a typical morphology of spores was observed with a protuberant front of the anchoring disc. Infection was confined to the epithelial cells of the hepatopancreas, with no other organ implicated. By sequencing the PCR products using specific primers based on conserved regions of microsporidian small subunit (18S) ribosomal DNA, it was revealed that the parasite from HPND ponds had 99% sequence identity to that of Hepatospora eriocheir. Phylogentic analysis also placed the microsporidian in the same lineage as H. eriocheir. This study reported the first case of widespread infections of H. eriocheir associated with HPND found in the pond-reared Chinese mitten crab, E. sinensis. The description of microsporidian in this important commercial host is fundamental for future consideration of factors affecting stock health and sustainability.

WITHDRAWN: In vivo micro-computed tomography evaluation of BoneCeramic grafted alveolar defects during orthodontic tooth movement

Ahead of Print article withdrawn by publisher.

[Establishment and evaluation of a mouse model of nonalcoholic steatohepatitis-related hepatocellular carcinoma]

OBJECTIVE

To establish an apolipoprotein E (ApoE) and low-density lipoprotein receptor (LDLR) double-knockout (ApoE(-/-)/LDLR(-/-)) mouse model of nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma (HCC) induced by high-fat and high-cholesterol (HFHC) diet.

METHODS

ApoE(-/-) knockout mice were crossed with LDLR(-/-) knockout mice to obtain ApoE(-/-)/LDLR(-/-) mice. The ApoE(-/-)/LDLR(-/-) mice mated with each other, and the offspring were injected with low-dose streptozotocin (STZ) at 2-3 days after birth. Some mice were fed with HFHC diet after weaning as the model group (n = 15), and some mice were fed with normal diet as the control group (n = 15). Mice were sacrificed at the end of weeks 10, 16, and 20 (5 mice at each time point). The body weight was measured. Liver tissue and blood were collected to measure biochemical parameters, evaluate the pathological changes in the liver tissue by HE staining, oil red O staining, and Masson staining, and detect the expression of glypican-3 (a marker of HCC) by immunohistochemical staining.

RESULTS

The model group had significantly higher levels of fasting blood glucose and total cholesterol than the control group (P < 0.01). Serum levels of alanine aminotransferase, aspartate aminotransferase, and total triglyceride gradually increased with time in the model group; at week 20, there were significant differences in above three indices between the two groups (P < 0.05). HE staining showed that compared with the control group at the corresponding time point, the model group developed sequential histological changes: NASH at week 10, dysplastic nodules at week 16, and early HCC at week 20. Oil red O staining showed that in the model group, the degree of liver steatosis increased within 10 weeks and gradually decreased later. Masson staining demonstrated that the model group developed pathological changes: mild perisinusoidal fibrosis at week 16 and bridging fibrosis around tumors at week 20. HE staining, oil red O staining, and Masson staining showed that no histological or pathological changes were found in the control group. Glypican-3 was detected in the nodules at week 16 and in the cytoplasm of HCC cells at week 20 in the model group.

CONCLUSION

The mouse model of NASH-related HCC can be developed by giving STZ injection to neonatal ApoE(-/-)/LDLR(-/-) mice and feeding them with HFHC diet after weaning for 20 weeks. Early HCC may develop directly from NASH.

Design and safety analysis of the helium cooled solid breeder blanket for CFETR

This paper reports the design and safety analysis results of the helium cooled solid breeder blanket of the Chinese Fusion Engineering Test Reactor (CFETR). Materials selection and basic structure of the blanket have been presented. Performance analysis including neutronics analysis and thermo-mechanical analysis has shown good results. And the safety analysis of the blanket under Loss Of Coolant Accident (LOCA) conditions has been described. Results showed the current design can deal well with the selected accident scenarios.

Prenatal diagnosis of trisomy 21, 18 and 13 by quantitative pyrosequencing of segmental duplications

Chromosomal aberration mostly occurs in chromosomes 21, 18 and 13, with an incidence approximately 1 out of 160 live births in humans, therefore making prenatal diagnosis necessary in clinics. Current methods have drawbacks such as time consuming, high cost, complicated operations and low sensitivity. In this paper, a novel method for rapid and accurate prenatal diagnosis of aneuploidy is proposed based on pyrosequencing, which quantitatively detects the peak height ratio (PHR) of different bases of segmental duplication. A direct polymerase chain reaction (PCR) approach was undertaken, where a small volume of amniotic fluid was used as the starting material without DNA extraction. Single-stranded DNA was prepared from PCR products and subsequently analyzed using pyrosequencing. The PHR between target and reference chromosome of 2.2 for euploid and 3:2 for a trisomy fetus were used as reference. The reference intervals and z scores were calculated for discrimination of aneuploidy. A total of 132 samples were collected, within trisomy 21 (n = 11), trisomy 18 (n = 3), trisomy 13 (n = 2), and unaffected controls (n = 116). A set of six segmental duplications were chosen for analysis. This method had consistent results with karyotyping analysis, a correct diagnosis with 100% sensitivity and 99.9% specificity.

Metformin Restrains Pancreatic Duodenal Homeobox-1 (PDX-1) Function by Inhibiting ERK Signaling in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most potent and perilous diseases known, with a median survival rate of 3-5 months due to the combination of only advanced stage diagnosis and ineffective therapeutic options. Metformin (1,1-Dimethylbiguanide hydrochloride), the leading drug used for type 2 diabetes mellitus, emerges as a potential therapy for PDAC and other human cancers. Metformin exerts its anticancer action via a variety of adenosine monophosphate (AMP)-activated protein kinase (AMPK)- dependent and/or AMPK-independent mechanisms. We present data here showing that metformin downregulated pancreatic transcription factor pancreatic duodenal homeobox-1 (PDX-1), suggesting a potential novel mechanism by which metformin exerts its anticancer action. Metformin inhibited PDX-1 expression at both protein and mRNA levels and PDX-1 transactivity as well in PDAC cells. Extracellular signal-regulated kinase (ERK) was identified as a PDX-1-interacting protein by antibody array screening in GFP-PDX-1 stable HEK293 cells. Co-transfection of ERK1 with PDX-1 resulted in an enhanced PDX-1 expression in HEK293 cells in a dose-dependent manner. Immunoprecipitation/Western blotting analysis confirmed the ERK-PDX-1 interaction in PANC-1 cells stimulated by epidermal growth factor (EGF). EGF induced an enhanced PDX-1 expression in PANC-1 cells and this stimulation was inhibited by MEK inhibitor PD0325901. Metformin inhibited EGF-stimulated PDX-1 expression with an accompanied inhibition of ERK kinase activation in PANC- 1 cells. Taken together, our studies show that PDX-1 is a potential novel target for metformin in PDAC cells and that metformin may exert its anticancer action in PDAC by down-regulating PDX-1 via a mechanism involving inhibition of ERK signaling.

Postdischarge mortality in children with acute infectious diseases: derivation of postdischarge mortality prediction models

OBJECTIVES

To derive a model of paediatric postdischarge mortality following acute infectious illness.

DESIGN

Prospective cohort study.

SETTING

2 hospitals in South-western Uganda.

PARTICIPANTS

1307 children of 6 months to 5 years of age were admitted with a proven or suspected infection. 1242 children were discharged alive and followed up 6 months following discharge. The 6-month follow-up rate was 98.3%.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was postdischarge mortality within 6 months following the initial hospital discharge.

RESULTS

64 children died during admission (5.0%) and 61 died within 6 months of discharge (4.9%). Of those who died following discharge, 31 (51%) occurred within the first 30 days. The final adjusted model for the prediction of postdischarge mortality included the variables mid-upper arm circumference (OR 0.95, 95% CI 0.94 to 0.97, per 1 mm increase), time since last hospitalisation (OR 0.76, 95% CI 0.61 to 0.93, for each increased period of no hospitalisation), oxygen saturation (OR 0.96, 95% CI 0.93 to 0·99, per 1% increase), abnormal Blantyre Coma Scale score (OR 2.39, 95% CI 1·18 to 4.83), and HIV-positive status (OR 2.98, 95% CI 1.36 to 6.53). This model produced a receiver operating characteristic curve with an area under the curve of 0.82. With sensitivity of 80%, our model had a specificity of 66%. Approximately 35% of children would be identified as high risk (11.1% mortality risk) and the remaining would be classified as low risk (1.4% mortality risk), in a similar cohort.

CONCLUSIONS

Mortality following discharge is a poorly recognised contributor to child mortality. Identification of at-risk children is critical in developing postdischarge interventions. A simple prediction tool that uses 5 easily collected variables can be used to identify children at high risk of death after discharge. Improved discharge planning and care could be provided for high-risk children.

Effects of dietary n-6/n-3 polyunsaturated fatty acid ratios on the mass, and histological and ultrastructures of liver, spleen and thymus of 70-day-old Yangzhou goslings

The objective of this study was to determine the effects of dietary n-6/n-3 polyunsaturated fatty acid (PUFA) ratios on the organ indexes, and histological and ultrastructures of organs including liver, spleen and thymus in 70-day-old Yangzhou goslings. One-hundred and sixty 21-day-old Yangzhou goslings were randomly divided into 4 groups and fed 4 diets varying in the n-6/n-3 PUFA ratio from 3:1 up to 12:1. After 1-week acclimation, the feeding experiment lasted for 6 weeks. At the end of the experimental period, goslings were slaughtered and the liver, spleen and thymus were weighed, and their histological and ultrastructures were examined. The results showed that the organ indices in the 3:1 group were remarkably higher than in the other three groups, whereas the mitochondrial square did not differ among four groups. The histological and ultrastructures of the liver, spleen and thymus were not affected by the diets with the lower n-6/n-3 PUFA ratios (3:1 and 6:1). However, feeding diets with the higher n-6/n-3 PUFA ratios (9:1 and 12:1), the nuclear chromatin was concentrated and marginalized; the cell membrane was contracted inwardly and disrupted; the mitochondrial membrane was damaged to some degree. In conclusion, the diet containing higher content of n-3 PUFA might improve immune capacity of goslings the animal by accelerating the growth and maintaining cellular structures of organs like liver, spleen and thymus.

Reduction of hydrogen sulfide synthesis enzymes in the esophagus of patients with achalasia: effect of hydrogen sulfide in achalasia

BACKGROUND

The aim of the present study was to investigate whether the synthesis of endogenous hydrogen sulfide (H2 S) was altered in achalasia patients and to determine the effects of H2 S on esophageal motility.

METHODS

(1) Tissue samples in lower esophageal sphincter (LES) were obtained from 22 achalasia patients during peroral endoscopic myotomy. LES muscle from eight esophageal carcinoma patients was obtained as control. The expression of cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) was detected by immunohistochemical staining. (2) Rabbit esophageal smooth muscle strips were used to measure isometric contractions. The effects of sodium hydrosulfide (NaHS) and L-cysteine on contractile activity and bethanechol-stimulated contractile activity were evaluated. The contraction of esophageal muscle strips was also measured after the inhibition of CBS and CSE by aminooxyacetic acid (AOA) and propargylglycine (PAG).

KEY RESULTS

Both CBS and CSE could be detected in biopsies from achalasia patients and controls. Compared with controls, the expression of CBS and CSE in the LES of achalasia patients was significantly reduced (p < 0.001). Both NaHS and L-cysteine concentration-dependently inhibited esophageal contractile activity (both p < 0.05). After inhibition of CBS and CSE by PAG and AOA, esophageal contractile activity increased significantly, and this effect could be restored by NaHS but not L-cysteine (p < 0.05).

CONCLUSIONS & INFERENCES

H2 S synthesis enzymes are significantly reduced in patients with achalasia compared with the controls. H2 S inhibits esophageal contractile activity concentration-dependently, and the inhibition of H2 S synthesis enzymes increases esophageal contractile activity. H2 S might be involved in the development of achalasia.

Pulsed dye laser therapy for infantile hemangiomas: a systemic review and meta-analysis

BACKGROUND

Infantile hemangiomas (IH) are common pediatric tumors. This meta-analysis was performed to review the therapeutic efficacy and safety of pulsed dye laser (PDL) in the treatment of IH.

METHODS

Seven databases were searched, including PubMed, OvidSP, Karger, Elsevier, EMBASE, Web of Science and Wiley Online Library. The review collected the characteristics of year of publication, hemangiomas cases, prior treatment, laser parameters, adverse side, pretreatment symptom, and number of response from all articles.

RESULTS

A total of 1580 studies were identified, the first round search retrieved 39 articles met inclusion criteria. Of those, only 13 articles with 1529 hemangiomas were included in the meta-analysis. This meta-analysis demonstrated an overall resolution rate of 89.1% with 6.28% incidence of adverse effect.

CONCLUSION

PDL may be the effective modality to decrease the proliferative phase and accelerate rates of involution and resolution with few adverse events.

TTAGG-repeat telomeres and characterization of telomerase in the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae)

Telomeres are maintained usually by telomerase, a specialized reverse transcriptase that adds this sequence to chromosome ends. In this study, telomerase activity was detected in the in different somatic tissues, such as midgut and fat bodies, by the telomeric repeat amplification protocol (TRAP) in Spodoptera exigua. The structure of the telomeres of S. exigua was evaluated by sequence analysis of the TRAP products, revealing that the telomerase synthesized a (TTAGG)n repeat. The presence of a telomerase reverse transcriptase (TERT) subunit coding gene has been cloned, sequenced and expressed in vitro successively. Notably, the S. exigua telomerase (SpexTERT) gene structure lacks the N-terminal GQ motif. Telomerase contains a large RNA subunit, TER, and a protein catalytic subunit, TERT. Here we report an in vitro system that was reconstructed by all components of the telomerase complex, a purified recombinant SpexTERT without a N-terminal GQ motif and a mutant human telomerase RNA (TER), showed telomerase activity. Together, these results suggest the GQ motif is not essential for telomerase catalysis.