Fabrication and characterization of hydrophilic poly(lactic-co-glycolic acid)/poly(vinyl alcohol) blend cell scaffolds by melt-molding particulate-leaching method

Porous PLGA/PVA scaffolds were fabricated by blending poly(lactic-co-glycolic acid) (PLGA) with polyvinyl alcohol (PVA) to improve the hydrophilicity and cell compatibility of the scaffolds for tissue engineering applications. PLGA/PVA blend scaffolds with different PVA compositions up to 20wt% were fabricated by a melt-molding particulate-leaching method (non-solvent method). The prepared scaffolds were investigated by scanning electron microscopy (SEM), mercury intrusion porosimetry, the measurements of water contact angles and bi-axial tensile strengths, etc. for their surface and bulk characterizations. The scaffolds exhibited highly porous and open-cellular pore structures with almost same surface and interior porosities (pore size, 200-300 microm; porosity, about 90%). The PLGA/PVA blend scaffolds with PVA compositions more than 5% were easily wetted in cell culture medium without any prewetting treatments, which is highly desirable for tissue engineering applications. In vitro cell compatibility of the control hydrophobic PLGA and hydrophilized PLGA/PVA (5wt%) blend scaffolds was compared by the culture of human chondrocytes in the scaffolds and the following analyses by MTT assay and SEM observation. It was observed that the PLGA/PVA blend scaffold had better cell adhesion and growth than the control PLGA scaffold. For in vivo evaluation of tissue compatibility, the scaffolds were implanted into the skull defects of rabbits. The results were evaluated by histology examinations. The PLGA/PVA (5wt%) blend scaffold showed better bone ingrowth into the scaffold and new bone formation inside the scaffold than the PLGA scaffold. It seems that 5% addition of PVA to PLGA to fabricate PLGA/PVA blend scaffolds is enough for improving the hydrophilicity and cell compatibility of the scaffolds.     

Analysis of children with type 1 diabetes in Korea: high prevalence of specific anti-islet autoantibodies, immunogenetic similarities to Western populations with "unique" haplotypes, and lack of discrimination by aspartic acid at position 57 of DQB

This study analyzed the expression of anti-islet autoantibodies and HLA-DR and -DQ genotypes in Korean children with type 1 diabetes mellitus (T1DM). The positivity of the anti-ICA512, anti-GAD65, and anti-insulin autoantibodies in the newly onset T1DM patients (n = 15) was 66.7%, 86.7%, and 46.7%, respectively, and all of them had one or more of the autoantibodies. HLA analysis showed higher frequencies of HLA-DRB1*0301, *0405, *09012 and -DQB1*0201, *0401, *03032 alleles in T1DM patients compared to controls (P(c) < 0.05). Because HLA-DQB1*0401, *03032 alleles carry aspartic acid at position 57 of DQB, susceptibility to T1DM in Korean children was not related to the presence of aspartic acid at position 57 of DQB1 locus. We suggest this unique HLA-DR, -DQ allele distribution might be an important factor for the low incidence of T1DM in Korea, and the combined anti-islet autoantibody assays could be valuable screening markers for the early detection of T1DM in Korea.     

Saliva as a diagnostic specimen for testing respiratory virus by a point-of-care molecular assay: a diagnostic validity study

Objectives

Automated point-of-care molecular assays have greatly shortened the turnaround time of respiratory virus testing. One of the major bottlenecks now lies at the specimen collection step, especially in a busy clinical setting. Saliva is a convenient specimen type that can be provided easily by adult patients. This study assessed the diagnostic validity, specimen collection time and cost associated with the use of saliva.

The gut microbiome in food allergy

Objective

To review observational human, murine, and interventional trial studies that have examined the gut microbiome in food allergy, and to provide perspective on future investigations in this field.

Altered GABAB receptor immunoreactivity in the gerbil hippocampus induced by baclofen and phaclofen, not seizure activity

The present study was performed to determine whether the effects induced by GABA(B) receptor-acting drugs would be related with the alteration in GABA(B) receptor expression in the hippocampus using Mongolian gerbil, a genetic epilepsy model. The distribution patterns of both GABA(B) receptor 1A/B and GABA(B)receptor 2 immunoreactivities were similarly detected in the hippocampi of normal and seizure-prone gerbils. Following baclofen (GABA(B) receptor agonist) or phaclofen (GABA(B) receptor antagonist) treatment, GABA(B) receptor immunoreactivities were decreased or increased by dose-dependent manners, respectively. Vigabatrin (GABA transaminase inhibitor) or 3-mercaptopropionic acid (GAD inhibitor) treatment did not affect GABA(B) receptor expressions. These findings suggest that GABA(B) receptor expression in the gerbil hippocampus may be altered by baclofen or phaclofen treatment.     

LY294002 inhibits LPS-induced NO production through a inhibition of NF-kappaB activation: independent mechanism of phosphatidylinositol 3-kinase

Phosphatidylinositol 3-kinase (PI3K) is critical player in cell proliferation and survival. The effects of LY294002 and wortmannin, inhibitors of PI3K, on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipoploysaccharide (LPS)-induced Raw 264.7 cells were investigated. Significant inhibition of LPS-induced protein kinase B (PKB, Akt) phosphorylation occurred at 25 microM LY294002 or 0.5 microM wortmannin. At the same concentrations, LY294002, but not wortmannin, significantly inhibited NO production and iNOS expression. LY303511, an inactive analogue of LY294002, also inhibited NO production and iNOS expression. In addition, LY294002 and LY303511 significantly inhibited the DNA binding activity of NF-kappaB and NF-kappaB dependent reporter gene expression. These results suggest that LY294002 inhibits iNOS expression at least in part via inhibition of NF-kappaB activation, independent of PI3K.     

Persistent monocytosis after intravenous immunoglobulin therapy correlated with the development of coronary artery lesions in patients with Kawasaki disease.

BACKGROUND AND PURPOSE: This study was conducted to investigate whether changes in the complete blood count (CBC)/differential count (DC) and C-reactive protein (CRP) were correlated to Kawasaki disease (KD) with coronary artery lesions (CALs). METHODS: A retrospective analysis was performed of all children with KD at Chang Gung Memorial Hospital at Kaohsiung from 2001 to 2006. KD patients were divided into those with and without CALs for testing of correlations with changes in CBC/DC and CRP levels. RESULTS: A total of 147 patients were enrolled for this analysis. Serial CBC/DC and CRP measurements and echocardiographic data for determination of CAL formation were obtained before and after intravenous immunoglobulin (IVIG) treatment. There were 44 (29%) KD patients having CAL formation (>3 mm in diameter of internal lumen). There was no significant difference in terms of age distribution and major diagnostic criteria between KD patients with and without CALs. Male KD patients, however, had a significantly higher rate of CAL formation (p=0.009). In multivariate logistical regression analysis, persistent monocytosis after IVIG treatment was the only factor significantly correlated to CAL formation (p=0.003). CONCLUSIONS: Of the febrile routine measurements of CBC/DC and CRP in KD, persistent monocytosis after IVIG treatment was correlated to CAL formation. Further studies to clarify the mechanism of monocytosis may help prevent the CALs of KD.