Identification of a novel HLA-B allele, HLA-B*40:238, in a Taiwanese individual.

The HLA-B*40:238 allele has one non-synonymous transversion from HLA-B*40:01:01 at nucleotide position 484.

Cytoplasmic myosin-exposed apoptotic cells appear with caspase-3 activation and enhance CLL cell viability.

The degree of chronic lymphocytic leukemia (CLL) B-cell antigen receptor (BCR) binding to myosin-exposed apoptotic cells (MEACs) correlates with worse patient outcomes, suggesting a link to disease activity. Therefore, we studied MEAC formation and the effects of MEAC binding on CLL cells. In cell line studies, both intrinsic (spontaneous or camptothecin-induced) and extrinsic (FasL- or anti-Fas-induced) apoptosis created a high percent of MEACs over time in a process associated with caspase-3 activation, leading to cytoplasmic myosin cleavage and trafficking to cell membranes. The involvement of common apoptosis pathways suggests that most cells can produce MEACs and indeed CLL cells themselves form MEACs. Consistent with the idea that MEAC formation may be a signal to remove dying cells, we found that natural IgM antibodies bind to MEACs. Functionally, co-culture of MEACs with CLL cells, regardless of immunoglobulin heavy-chain variable region gene mutation status, improved leukemic cell viability. Based on inhibitor studies, this improved viability involved BCR signaling molecules. These results support the hypothesis that stimulation of CLL cells with antigen, such as those on MEACs, promotes CLL cell viability, which in turn could lead to progression to worse disease.

A new HLA-B*39 allele, HLA-B*39:01:15, discovered in a Taiwanese rheumatoid arthritis patient.

The new allele B*39:01:15 differs from B*39:01:01 by a point mutation at position 315 (G>T) of exon 2.

A novel pseudo-protein-based biodegradable coating for magnesium substrates: in vitro corrosion phenomena and cytocompatibility.

The goal of this study is to examine whether a member of the newly developed biodegradable pseudo-protein biomaterial family could provide a far better protection and performance than the popular hydrolytically degradable poly(glycolide-co-lactide) (PLGA) biomaterial on an experimental magnesium substrate as a model. A member of the phenylalanine-based poly(ester amide)s, (8-Phe-4), was chosen as a model pseudo-protein polymer to coat onto as-cast magnesium (Mg) metal as the experimental model. The microstructures of the coatings were characterized by SEM, FTIR and water contact angle measurements. Nano-scratch test data indicated that the scratch resistance and elastic resilience of the 8-Phe-4 coating were superior to the PLGA coating. Standard electrochemical measurements along with the long-term immersion results indicated that the 8-Phe-4-coated Mg had preferable in vitro degradation and corrosion behavior than the PLGA-coated Mg. The cytocompatibility test was conducted via vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (ECV304), and the 8-Phe-4-coated Mg showed significantly better cell viability than the pure Mg and PLGA-coated Mg substrates over a 3 day incubation period. The favorable anti-corrosion behavior and cytocompatibility of the 8-Phe-4 coating suggest that the newly developed biodegradable pseudo-protein biomaterials may have great potential as biodegradable coating materials to enhance the protection and performance of Mg-based biomaterials and their application compared to the popular PLGA, and may bring the application of Mg-based biomaterials closer to clinical reality.

Electrostatically self-assembled biodegradable microparticles from pseudoproteins and polysaccharide: fabrication, characterization, and biological properties.

Electrostatically self-assembling hybrid microparticles derived from novel cationic unsaturated arginine-based poly(ester amide) polymers (UArg-PEA) and anionic hyaluronic acid (HA) were fabricated into sub-micron-sized particles in aqueous medium with subsequent UV crosslinking treatment to stabilize the structure. These hybrid microparticles were characterized for size, charge, viscosity, chemical structure, morphology, and biological properties. Depending on the feed ratio of cationic UArg-PEA to anionic HA, the crosslinked microparticles formed spherical structures of 0.772-22.08 µm in diameter, whereas the uncrosslinked microparticles formed a core with an outer petal-like structure of 2.49-15 µm in diameter. It was discovered that the morphological structure of the self-assembled microparticles had a profound influence on their biological properties. At a 1:1 feed ratio of UArg-PEA to HA, the uncrosslinked microparticles showed no cytotoxicity toward NIH 3T3 fibroblasts at concentrations up to 20 µg/mL, and the crosslinked particles exhibited no cytotoxicity at concentrations up to 10 µg/mL. The UArg-PEA/HA hybrid microparticles exhibited a significantly lower macrophage-induced proinflammatory response (via TNF-α) than that from a pure hyaluronic acid control while retaining the beneficial anti-inflammatory IL-10 production by HA. The UArg-PEA/HA microparticles also stimulated size-dependent induction of arginase activity. Therefore, self-assembling these two types of biomaterials in a favorable nontoxic aqueous environment, having complementary biological properties like those of the currently reported UArg-PEA/HA hybrid microparticles, may provide a new class of biomaterials to improve the overall tissue microenvironment for promoting wound healing.

Reduction of suture associated inflammation after 28 days using novel biocompatible pseudoprotein poly(ester amide) biomaterials.

Sutures elicit an inflammatory response, which may impede the healing process and result in wound complications. We recently reported a novel family of biocompatible, biodegradable polymers, amino acid-based poly(ester amide)s (AA-PEA), which we have shown to significantly attenuate the foreign body inflammatory response in vitro. Two types of AA-PEA (Phe-PEA and Arg-Phe-PEA) were used to coat silk or plain-gut sutures, which were implanted in the gluteus muscle of C57BL/6 mice, while the uncoated control sutures were implanted in the contralateral side. After 3, 7, 14, and 28 days the mean area of inflammation surrounding the sutures was compared. Phe-PEA coating of silk sutures significantly decreased inflammation compared with noncoated controls (67.8 ± 17.4% after 3d [p = 0.0014], 51.6 ± 7.2% after 7d [p < 0.001], and 37.3 ± 8.3% after 28d [p = 0.0001]) when assessed via analysis of photomicrographs using digital image software. Phe-PEA coated plain-gut sutures were similarly assessed and demonstrated a significant decrease in the mean area of inflammation across all time points (54.1 ± 8.3% after 3 d, 41.4 ± 3.9% after 7 d, 71.5 ± 8.1% after 14 d, 78.4 ± 8.5%, and after 28 d [all p < 0.0001]). Arg-Phe-PEA coated silk demonstrated significantly less inflammation compared to noncoated controls (61.3 ± 9.4% after 3 d, 44.7 ± 4.7% after 7 d, 19.6 ± 8%, and 38.3 ± 6.8% after 28 d [all p < 0.0001]), as did coated plain-gut (37.4 ± 8.3% after 3 d [p = 0.0004], 55.0 ± 7.8% after 7 d [p < 0.0001], 46.0 ± 4.6% after 14 d [p < 0.0001], and 59.0 ± 7.9% after 28 d [p < 0.0001]). Both Phe-PEA and Arg-Phe-PEA coatings significantly decrease the inflammatory response to sutures in vivo for up to 28 days.

Evaluation of two chlorhexidine-alcohol-based skin disinfectants in blood donation setting.

BACKGROUND: Source reduction is important in minimizing bacterial-contaminated risk of blood products, but previous evaluation of chlorhexidine (CHX) was confounded by inability of Tween and lecithin to neutralize CHX. The study aims to address this limitation and also evaluates the effectiveness of two CHX­alcohol-based skin disinfectants in blood donation setting. METHODS: A two-stage observational study was conducted. A single step 2% chlorhexidine gluconate/70% isopropyl alcohol brush (CHX/IPA-1) was first compared with current skin disinfection procedure consisting of sequential application of 10% povidone-iodine and 70% isopropyl alcohol (PI/IPA). Standard plates with conventional neutralizers (0·3% Tween-80, 0·1% lecithin) were used to enumerate residual bacterial counts. Then, CHX/IPA-1 was compared with another applicator CHX/IPA-2 with identical disinfectant contents using in-house plates with neutralizers (3% Tween-80, 0·3% lecithin, 0·1% histidine, 0·5% sodium thiosulphate, 3% saponin, 1% ether sulphate) having enhanced ability to neutralize CHX. RESULTS: All three products were found to reduce plate counts by > 2 log10 after disinfection. The CHX/IPA-1 group gave fewer residual bacterial growth on standard plates than PI/IPA group (5·9% vs. 61·7%, P < 0·001). With the use of in-house plates, residual bacterial growth was of no difference in both CHX/IPA-1 and CHX/IPA-2 groups (42·5% vs. 49·4%, P = 0·26). CONCLUSION: Good efficacy was observed with one-stage application of CHX/IPA in predonation skin disinfection and it could replace PI/IPA. However, the efficacy of CHX/IPA could be grossly overestimated in testing with standard plates because of insufficient neutralization

HLA-DPB1 and anti-HBs titer kinetics in hepatitis B booster recipients who completed primary hepatitis B vaccination during infancy.

Previously we reported significant associations of the human leukocyte antigen (HLA)-DPB1 05:01 with memory against hepatitis B (HB) vaccination. However, the effects of HLA-DPB1 on antibodies to hepatitis B surface antigen (anti-HBs) kinetics were not explored. We followed up a cohort of 1974 HB booster recipients and quantified their 1-month and 1-year post-booster anti-HBs titers. A total of 681 subjects were randomly selected and typed for HLA-DPB1. We found that male subjects, undetectable pre-booster titers, and 05:01 homozygotes led to significantly lower post-booster anti-HBs titers. The geometric means (95% confidence interval (CI)) of 1-month post-booster anti-HBs titers were 4.68 (2.69-8.12), 23.01 (14.96-35.40) and 50.06 (27.20-92.13) mIU ml(-1) for subjects carrying two, one and no HLA-DPB1 05:01 allele. The corresponding figures for 1-year post-booster anti-HBs titers were 1.26 (0.73-2.18), 4.72 (3.08-7.25) and 7.32 (3.75-13.56) mIU ml(-1). There were significant associations of post-booster anti-HBs titers with the number of HLA-DPB1 risk and protective alleles. Among booster responders, anti-HBs decay rates were significantly reduced in subjects who had detectable pre-booster anti-HBs titers and the HLA-DPB1 05:01 allele. Our results indicated that HLA-DPB1 influences the kinetics of anti-HBs. The long-term memory against hepatitis B surface antigen (HBsAg) and the residual serum titers of anti-HBs after HB vaccination may be influenced by different mechanisms as evidenced by their inverse trend of associations with the 05:01 allele.

Identification of a novel HLA-B allele, B*07:162, in a Taiwanese individual.

The new allele, HLA-B*07:162, is identical to HLA-B*07:12 in exon 2 but has a non-synonymous substitution at position 419 (A to C) in exon 3.

Characterization of the novel HLA-DPA1*02:02:04 allele.

HLA-DPA1*02:02:04 is identical to DPA1*02:02:03 except for a synonymous change at nucleotide position 138 (C to G) in exon 2.

Distinct features between longitudinally extensive transverse myelitis presenting with and without anti-aquaporin 4 antibodies.

OBJECTIVES: Longitudinally extensive transverse myelitis (LETM) with spinal cord lesions spanning three or more vertebral segments is a key feature of neuromyelitis optica (NMO). However, the role of anti-aquaporin 4 (anti-AQP4) antibody, a sensitive biomarker of NMO, in the conversion of LETM to NMO remains uncertain. METHODS: Thirty first-ever LETM patients were retrospectively analysed and divided into two groups according to the presence of anti-AQP4 antibodies. RESULTS: Eighteen (60%) patients presented with anti-AQP4 antibodies. Fifteen (83.33%) anti-AQP4 (+) LETM patients converted to NMO, while only three of 12 (25%, p = 0.002) anti-AQP4 (-) LETM patients progressed to NMO, over a mean follow-up period of 5.63 years. Seven (38.89%) anti-AQP4 (+) and one (8.33%) anti-AQP4 (-) LETM patients received interferon-ß1a treatment, respectively. Anti-AQP4 (+) LETM patients demonstrated a higher immunogamma globulin (IgG) index (0.68 ± 0.43 versus 0.47 ± 0.19, p = 0.018), annual relapse rate (0.72 ± 0.31 versus 0.42 ± 0.17, p = 0.01) and Kurtzke Expanded Disability Status Scale (4.28 ± 2.22 versus 2.67 ± 2.26, p = 0.031), than anti-AQP4 (-) LETM patients. In spinal magnetic resonance imaging (MRIs), more than half (58.33%) of the anti-AQP4 (+) LETM patients were observed to have central grey matter-predominant involvement in the axial view, while peripheral white matter-predominant involvement (51.85%) was the most common pattern observed in the anti-AQP4 (-) LETM patients. CONCLUSION: Anti-AQP4 (+) LETM demonstrated a high conversion rate to NMO (83.33%), suggesting that anti-AQP4 (+) LETM may represent an early, isolated syndrome of NMO spectrum disorder. The greater number of patients receiving interferon-ß treatment in anti-AQP4 (+) LETM may contribute to its high annual relapse rate.

The HLA-B gene and Hashimoto disease in Han Chinese children: a case-control and family-based study.

Hashimoto disease (HD) is an autoimmune thyroid disease resulting from complex interactions between genetic and environmental factors. The human leukocyte antigen (HLA) gene has been established to be involved in the susceptibility to HD. We aim to investigate the associations between HLA-B alleles and Han Chinese children with HD by both case-control and family-based studies. A total of 108 unrelated children with HD, 380 unrelated healthy controls, 58 trios of affected patients and their parents, and 75 trios of unaffected siblings and their parents were recruited. HLA-B genotyping was performed by polymerase chain reaction and detected with a sequence-specific oligonucleotide probes system. We found that B*46:01 allele (OR = 2.31, 95% CI 1.60-3.34, P(c) = 9.99 × 10(-5)) and carrier (OR = 3.28, 95% CI 2.10-5.11, P(c) = 1.35 × 10(-6)) were associated with HD risk. Transmission/disequilibrium test further confirmed an overtransmission of the B*46:01 (OR 2.55, 95% CI 1.36-6.10, P = 6.5 × 10(-3)). The findings were similar in females when stratified by gender. In conclusion, our results clearly identify that HLA-B*46:01 confers susceptibility to HD in Han Chinese children. Further studies with larger children cohort are required to confirm the role of B*46:01 in the development of HD.

Rapid 3D printing of anatomically accurate and mechanically heterogeneous aortic valve hydrogel scaffolds.

The aortic valve exhibits complex three-dimensional (3D) anatomy and heterogeneity essential for the long-term efficient biomechanical function. These are, however, challenging to mimic in de novo engineered living tissue valve strategies. We present a novel simultaneous 3D printing/photocrosslinking technique for rapidly engineering complex, heterogeneous aortic valve scaffolds. Native anatomic and axisymmetric aortic valve geometries (root wall and tri-leaflets) with 12-22 mm inner diameters (ID) were 3D printed with poly-ethylene glycol-diacrylate (PEG-DA) hydrogels (700 or 8000 MW) supplemented with alginate. 3D printing geometric accuracy was quantified and compared using Micro-CT. Porcine aortic valve interstitial cells (PAVIC) seeded scaffolds were cultured for up to 21 days. Results showed that blended PEG-DA scaffolds could achieve over tenfold range in elastic modulus (5.3±0.9 to 74.6±1.5 kPa). 3D printing times for valve conduits with mechanically contrasting hydrogels were optimized to 14 to 45 min, increasing linearly with conduit diameter. Larger printed valves had greater shape fidelity (93.3±2.6, 85.1±2.0 and 73.3±5.2% for 22, 17 and 12 mm ID porcine valves; 89.1±4.0, 84.1±5.6 and 66.6±5.2% for simplified valves). PAVIC seeded scaffolds maintained near 100% viability over 21 days. These results demonstrate that 3D hydrogel printing with controlled photocrosslinking can rapidly fabricate anatomical heterogeneous valve conduits that support cell engraftment.

Observation of new Rydberg series in the many-electron transition region of N2.

Fluorescence excitation spectra produced through photoexcitation of N(2) using synchrotron radiation in the spectral region between 50 and 62.5 nm have been obtained with a resolution of 0.004 nm. A broadband detector (in the 115-180 nm region) was employed to monitor fluorescence originated from neutral excited atomic nitrogen fragments which are produced through direct dissociation processes and predissociation from the well-known many-electron excited Rydberg states. We have identified a new Rydberg series (2 (2)Π(g)) 4sσ, a better resolved Rydberg (D (2)Π(g)) npσ series, and also the prominent Codling series converging to the D (2)Π(g), and C (2)Σ(u)(+) states of N(2)(+), respectively. By normalizing our relative fluorescence intensities to previously measured absolute fluorescence cross-section data we obtain the cross-section data of undispersed fluorescence in the 115-180 nm region. The fluorescence quantum yields for the present photodissociative excitation processes are found to be less than 0.05. The present results may provide important data for our understanding of competitions among the various decay channels of the many-electron transition states of N(2).

Prophylactic 0.9% saline hydration inhibited high-dose gadodiamide-induced nephropathy in rats.

High doses of gadolinium-based contrast media are reported to induce deterioration of renal function. We assessed whether prophylactic 0.9% saline hydration inhibits high-dose gadodiamide-induced renal damage in rats. Twelve Sprague-Dawley rats were randomly divided into two groups, which are given gadodiamide (5 mmol/kg) with (hydration group) or without (control group) 0.9% saline hydration. The saline (4 mL/kg) was infused as a bolus into the peritoneum every 4 h, starting 12 h before and continuing for 12 h after the gadodiamide injection. Urine was collected to calculate creatinine clearance (Ccr) 24 h before and 48 h after the gadodiamide injection. The kidneys were harvested and stained for pathologic analysis. High-dose gadodiamide induced acute kidney injury as shown by decreased Ccr and renal histology with tubular cell injuries 48 h postinjection in both the groups. However, the extent of Ccr reduction was significantly (p = 0.02) less in the hydrated rats (-15% in the hydration group vs. -39% in the control group). Renal tubular cell injuries characterized by vacuolization, loss of brush borders, sloughing of tubular cells into the lumen, and flattening of the tubular epithelium were less frequently seen in the hydration group; only vacuolization (p = 0.01) and epithelial sloughing (p = 0.02) of the proximal tubules differed significantly between the two groups. We conclude that prophylactic 0.9% saline hydration significantly inhibited high-dose gadodiamide-induced nephropathy.

The HLA-DRB1 gene and Graves disease in Taiwanese children: a case-control and family-based study.

Graves disease (GD) is an autoimmune thyroid disease with a female preponderance and a wide range of ages at onset, and human leukocyte antigen (HLA) gene plays a primary role in the susceptibility to GD. We aim to investigate the associations between HLA-DRB1 alleles and Taiwanese children with GD by both case-control and family-based studies. A total of 241 unrelated children with GD, 539 healthy controls, 115 trios of affected patients and their parents, and 121 trios of unaffected siblings and their parents were recruited. HLA-DRB1 genotyping was performed by polymerase chain reaction and sequence-based typing assays. We found that DRB1*09:01 (OR=2.60, 95% CI 2.02-3.35, Pc=6.55×10(-13)) was associated with GD risk, while DRB1*12:02 (OR=0.32, 95% CI 0.20-0.53, Pc=4.55×10(-5)) was protective against GD. Transmission/disequilibrium test further confirmed an overtransmission of the DRB1*09:01 (OR 3.37, 95% CI 2.13-6.22, Pc=1.0×10(-5)) and an undertransmission of the DRB1*12:02 (OR 0.21, 95% CI 0.05-0.42, Pc=1.7×10(-3)). The findings were similar in females when stratified by gender. In conclusion, our results clearly identify that HLA-DRB1*09:01 confers susceptibility to GD and DRB1*12:02 exerts protection against GD development in Taiwanese children.

HLA-A*11:53 is shown to be identical to the corrected A*11:02:01 allele sequence.

According to the IMGT/HLA Database, the DNA sequence of A*11:53 is identical to A*11:02:01 in exons 2, 3, 4 and 5 except at codon 276. A*11:53 was reported as a rare variant of A*11, while A*11:02:01 was understood to be the second most frequently observed variant of A*11 after A*11:01:01 in Taiwanese. We sequenced HLA-A locus exons 2, 3, 4 and 5 of Taiwanese blood donors (n = 50) previously typed to carry A*11:02:01. We found out all of their sequences are identical to A*11:53 in exons 2, 3, 4 and 5' part of exon 5 including codon 276.

Identification of two novel HLA-B*40 alleles, B*40:137 and B*40:158, in Taiwanese individuals.

Using sequence-based typing method we discovered two new HLA-B*40 variants, B*40:137 and B*40:158, in Taiwanese individuals. The sequence of B*40:137 has three nucleotide (nt) changes from B*40:21 at nt 353 (C→T), nt 355 (C→A) and nt 369 (C→T) resulting two coding changes at residue 94 (T→I) and residue 95 (L→I), whereas the sequence of B*40:158 differs from B*40:01:01 with five nt substitutes at nt 463 (C→A), nt 477 (C→G), nt 499 (T→A), nt 512 (T→G) and nt 527 (T→A) causing five amino acid exchanges at codons 140 (Y→S), 155 (R→S), 168 (S→T), 171 (L→W) and 179 (V→E). Our hypotheses on the generation of the two novel alleles are presented.