Identification of 58 novel HLA alleles identified in Chinese individuals by next-generation sequencing.

HLA genes are the most polymorphic in the human genome. High resolution HLA typing from 13,870 bone marrow donors in Hong Kong was obtained using Next-generation sequencing (NGS) technology. Among the 67 novel alleles identified, official HLA allele names of 50 novel class I alleles (HLA-A, -B, -C) and 8 novel class II alleles (HLA-DRB1, -DQB1) were assigned by the World Health Organization (WHO) Nomenclature Committee for Factors of the HLA System.

Corrigendum to "Validation of the 5-D Itch Scale in Three Ethnic Groups and Exploring Optimal Cutoff Values Using the Itch Numerical Rating Scale".

[This corrects the article DOI: 10.1155/2021/7640314.].

Measurement invariance of the Multidimensional Depression Assessment Scale (MDAS) across gender and ethnic groups of Asian, Caucasian, Black, and Hispanic.

BACKGROUND: Major Depressive Disorder is a severe and highly disabling mental illness. Almost all self-reported questionnaires have overlooked the interpersonal symptoms of depression which are important across gender and culture. The Multidimensional Depression Assessment Scale (MDAS) developed by Cheung and Power (2012) entails comprehensive emotional, cognitive, somatic, and interpersonal subscales. It addresses the criticism that existing self-report depression scales might not cover sufficient phenomenological heterogeneity of depression. The current study aimed to evaluate the psychometric properties of the MDAS across gender and four major ethnic groups of Caucasian, Black, Asian and Hispanic, including reliability and concurrent validity against the Centre for Epidemiological Studies Depression Scale (CESD) and Patients Health Questionnaire (PHQ-9). It also aimed to establish a stable factor structure across gender and ethnic groups and test the measurement invariance to enhance its potential for clinical use. METHODS: A community sample of 3499 participants from four ethnic groups were recruited via online crowdsourcing sites of Qualtrics and Amazon M Turk. Each individual completed a demographic questionnaire, the MDAS, CESD and PHQ-9. RESULTS: There was good internal consistency (Cronbach's alpha >0.90) and concurrent reliability across gender and ethnic groups. Strict measurement invariance was established for MDAS over a four-factor factor structure corresponding to the four subscales. CONCLUSIONS: The MDAS showed good psychometric properties and measurement invariance of a four-factor structure, suggesting its potential to be used in clinical settings across gender and ethnic groups. LIMITATIONS: Participants all answered the questionnaires in English, which could hinder cultural variations in their expression of symptoms.

Validation of the 5-D Itch Scale in Three Ethnic Groups and Exploring Optimal Cutoff Values Using the Itch Numerical Rating Scale.

BACKGROUND: Chronic pruritus is a common and distressing condition that has serious emotional and psychosocial consequences. Due to its subjective nature, self-report questionnaires are widely implemented as cost-effective measures to gauge the severity of chronic pruritus. The current study is aimed at validating the 5-D itch scale in three ethnic groups-Black, Asian, and Hispanic-with the well-validated Itch Numerical Rating Scale (NRS) and Worst Itch NRS (WI-NRS) and developing its cutoff value using receiver operating characteristics (ROC) and inspection of the area under the curve (AUC) across ethnic groups. At the same time, it is aimed at comparing the concurrent prevalence of itch and depression in these populations, who often form ethnic minorities in many countries. The current study addresses the knowledge gap of cultural adaptation of the 5-D pruritus scale for greater usage. METHODS: Community samples of three ethnic groups were recruited from an online platform of Qualtrics and administered the self-report questionnaires of Itch-NRS, 5-D itch scale, and Patient Health Questionnaire-9 (PHQ-9) to measure their pruritus domains, itch intensity, depression screening, and its severity. Informed consent was obtained from all participants. Subgroup analysis was conducted, including concurrent validity and cutoff values compared between each ethnic group. Concurrent prevalence of itch and depression was evaluated using the cutoff value of Itch-NRS and PHQ-9. RESULT: A total of 2323 participants were included in the study. A significant positive correlation (p < 0.001) was found between the Itch-NRS, WI-NRS, and 5-D itch scale. The cutoff value of the 5-D itch scale was established for the three ethnic groups using ROC, with a cutoff value of Itch-NRS as a reference. CONCLUSIONS: The 5-D itch scale has demonstrated sound psychometric properties in three ethnic groups and is closely related to Itch-NRS. The analysis of the cutoff value of the 5-D itch scale suggests that different cutoff values should be considered to reduce the inflation of pruritus severity.

High resolution allele genotyping and haplotype frequencies for NGS based HLA 11 loci of 5266 Hong Kong Chinese bone marrow donors.

Next-generation sequencing (NGS) at the HLA-A, -B, -C, -DRB1, -DRB3/4/5, -DQA1, -DQB1, -DPA1, and -DPB1 loci was performed on 5,266 southern Chinese unrelated donors of the Hong Kong Bone Marrow Donor Registry. High-resolution HLA genotypes defined by full sequencing of class I loci and extended coverage of class II loci were attained to determine allele frequencies and estimate haplotype frequencies. This study provides allele and haplotype frequencies on 11 loci estimated for the first time in the Hong Kong Chinese population. These results describe extended haplotypes including the less frequently typed HLA-DPA1, -DPB1 and -DQA1 loci and distinctive haplotype associations. The present data are timely in that they allow the permissible matching in HLA-DPB1 for Chinese patients awaiting haematopoietic stem cell transplantation upon applying the latest requirement of NMDP matching guidelines. Overall, these results provide a useful reference source for population genetics studies, HLA-disease association studies and for improving donor recruitment and selection strategies of bone marrow registries. The allele and haplotype data are available in the Allele Frequencies Net Database under the population name ''Hong Kong Chinese HKBMDR, HLA 11 loci'' and the identifier (AFND3724) [1].

The gelling effect of platelet-rich fibrin matrix when exposed to human tenocytes from the rotator cuff in small-diameter culture wells and the design of a co-culture device to overcome this phenomenon.

OBJECTIVES: Platelet-rich fibrin matrix (PRFM) has been proved to enhance tenocyte proliferation but has mixed results when used during rotator cuff repair. The optimal PRFM preparation protocol should be determined before clinical application. To screen the best PRFM to each individual's tenocytes effectively, small-diameter culture wells should be used to increase variables. The gelling effect of PRFM will occur when small-diameter culture wells are used. A co-culture device should be designed to avoid this effect. METHODS: Tenocytes harvested during rotator cuff repair and blood from a healthy volunteer were used. Tenocytes were seeded in 96-, 24-, 12-, and six-well plates and co-culture devices. Appropriate volumes of PRFM, according to the surface area of each culture well, were treated with tenocytes for seven days. The co-culture device was designed to avoid the gelling effect that occurred in the small-diameter culture well. Cell proliferation was analyzed by water soluble tetrazolium-1 (WST-1) bioassay. RESULTS: The relative quantification (condition/control) of WST-1 assay on day seven revealed a significant decrease in tenocyte proliferation in small-diameter culture wells (96 and 24 wells) due to the gelling effect. PRFM in large-diameter culture wells (12 and six wells) and co-culture systems induced a significant increase in tenocyte proliferation compared with the control group. The gelling effect of PRFM was avoided by the co-culture device. CONCLUSION: When PRFM and tenocytes are cultured in small-diameter culture wells, the gelling effect will occur and make screening of personalized best-fit PRFM difficult. This effect can be avoided with the co-culture device.Cite this article: C-H. Chiu, P. Chen, W-L. Yeh, A. C-Y. Chen, Y-S. Chan, K-Y. Hsu, K-F. Lei. The gelling effect of platelet-rich fibrin matrix when exposed to human tenocytes from the rotator cuff in small-diameter culture wells and the design of a co-culture device to overcome this phenomenon. Bone Joint Res 2019;8:216-223. DOI: 10.1302/2046-3758.85.BJR-2018-0258.R1.

Recovery of Lactobacillus casei strain Shirota (LcS) from faeces of healthy Singapore adults after intake of fermented milk.

To validate survival of Lactobacillus casei strain Shirota (LcS) during passage through the gastrointestinal tract of healthy Singaporean young adults, 21 participants (18-25 years old) were asked to consume a 100 ml of fermented milk drink containing 1.0×108 cfu/ml of LcS daily for 14 days, and to maintain their dietary habit and life style. During and at the end of the ingestion period, both culture method (identity confirmed by ELISA) and 16s rRNA sequencing results revealed that viable LcS (7.27 and 7.64 log10 cfu/g of faeces at the ingestion period Day 7 and Day 14, respectively) and Lactobacillus could be recovered from the faeces of all the subjects. The viable LcS count from male and female were comparable for each time point. Before consumption (baseline) and 14 days after cessation of consumption of the fermented milk, LcS was not detected in most of the subjects. In this study condition, the composition of the major gut microbiota (>0.1% in relative abundance of genus) and characteristics of defaecation such as stool consistency and frequency of defecation did not change throughout the study before and after ingestion of LcS. LcS was able to survive passage through the gastrointestinal tract of Singapore adults without sustainable colonisation, but the effect of LcS on microbiota modulation, stool consistency and frequency was not observed under this study condition.

In vitro antidermatophytic activity and cytotoxicity of extracts derived from medicinal plants and marine algae.

OBJECTIVES: This study was conducted to evaluate the antidermatophytic activity of 48 extracts obtained from medicinal plants (Cibotium barometz, Melastoma malabathricum, Meuhlenbeckia platyclada, Rhapis excelsa, Syzygium myrtifolium, Vernonia amygdalina) and marine algae (Caulerpa sertularioides, Kappaphycus alvarezii) against Trichophyton rubrum and Trichophyton interdigitale (ATCC reference strains), and the cytotoxicity using African monkey kidney epithelial (Vero) cells. Active plant extracts were screened for the presence of phytochemicals and tested against clinical isolates of Trichophyton tonsurans. METHODS: Six different extracts (hexane, chloroform, ethyl acetate, ethanol, methanol and water) were obtained from each plant or algae sample using sequential solvent extraction. The antidermatophytic activity for the extracts was assessed using a colourimetric broth microdilution method. The viability of Vero cells was measured by Neutral Red uptake assay. RESULTS: All the extracts (except the water extracts of V. amygdalina, C. sertularioides and K. alvarezii) showed antidermatophytic activity against Trichophyton spp. The minimum fungicidal concentration (MFC) ranges for the plant extracts against T. rubrum and T. interdigitale are 0.0025-2.50 and 0.005-2.50mg/mL, respectively. The algae extracts exhibited lower potency against both species, showing MFC ranges of 0.08-2.50 and 0.31-2.50mg/mL, respectively. The ethanol and methanol extracts from the leaves of R. excelsa, and the methanol and water extracts from the leaves of S. myrtifolium were highly active (MFC<0.1mg/mL) and with high selectivity indices (SI>2.8) against reference strains of T. rubrum and T. interdigitale, and most of the clinical isolates of T. tonsurans. Phytochemical analysis indicates the presence of alkaloids, anthraquinones, flavonoids, saponins, tannins, phenolics and triterpenoids in the extracts. CONCLUSIONS: The medicinal plant extracts exhibited stronger antidermatophytic activity compared to the algae extracts. The leaves of R. excelsa and S. myrtifolium are potential sources of new antidermatophytic agents against Trichophyton spp.

Derivation of Fate-Committed Schwann Cells from Bone Marrow Stromal Cells of Adult Rats.

Our goal is to derive phenotypically stable Schwann cells from bone marrow stromal cells (BMSCs) for use in transplantation studies of central/peripheral nerve injuries. With the adult rat as model, here we describe steps that foster (1) expansion of the BMSC subpopulation of neural progenitors as neurosphere cells, (2) differentiation of the progenitors into Schwann cell-like cells in adherent culture supplemented with soluble factors, and (3) cell-intrinsic switch of Schwann cell-like cells to the Schwann cell fate following co-culture with sensory neurons purified from dorsal root ganglia. The derived Schwann cells retain marker expression despite withdrawal of supplements and neuronal cues, survive passaging and cryopreservation, and, importantly, show functional capacity for myelination.

The MNS glycophorin variant GP.Mur affects differential erythroid expression of Rh/RhAG transcripts.

BACKGROUND: The band 3 macrocomplex (also known as the ankyrin-associated complex) on the red cell membrane comprises two interacting subcomplexes: a band 3/glycophorin A subcomplex, and a Rh/RhAG subcomplex. Glycophorin B (GPB) is a component of the Rh/RhAG subcomplex that is also structurally associated with glycophorin A (GPA). Expression of glycophorin B-A-B hybrid GP.Mur enhances band 3 expression and is associated with lower levels of Rh-associated glycoprotein (RhAG) and Rh polypeptides. The goal of this study was to determine whether GP.Mur influenced erythroid Rh/RhAG expression at the transcript level. MATERIALS AND METHODS: GP.Mur was serologically determined in healthy participants from Taitung County, Taiwan. RNA was extracted from the reticulocyte-enriched fraction of peripheral blood, followed by reverse transcription and quantitative PCR for RhAG, RhD and RhCcEe. RESULTS: Quantification by real-time PCR revealed significantly fewer RhAG and RhCcEe transcripts in the reticulocytes from subjects with homozygous GYP*Mur. Independent from GYP.Mur, both RhAG and RhD transcript levels were threefold or higher than that of RhCcEe. Also, in GYP.Mur and the control samples alike, direct quantitative associations were observed between the transcript levels of RhAG and RhD, but not between that of RhAG and RhCcEe. CONCLUSION: Erythroid RhD and RhCcEe were differentially expressed at the transcript levels, which could be related to their different degrees of interaction or sensitivity to RhAG. Further, the reduction or absence of glycophorin B in GYP.Mur erythroid cells affected transcript expressions of RhAG and RhCcEe. Thus, GPB and GP.Mur differentially influenced Rh/RhAG expressions prior to protein translation.

Identification of the novel HLA-B*39:01:01:04 allele in a Chinese individual by sequence-based typing.

The new HLA-B*39:01:01:04 allele differs from HLA-B*39:01:01 by a C → T substitution in intron 1.

HLA-A, -B and -DRB1 genotyping and haplotype frequencies of 3892 cord blood units in the Hong Kong Chinese Cord Blood Registry.

HLA-A, -B and -DRB1 gene and haplotype frequencies have been calculated from 3892 southern Chinese unrelated cord blood units in a Hong Kong Cord Blood Registry. This is the first large-scale paper to report the distribution of A-B-DRB1 alleles in Hong Kong Chinese Cord Blood Units. This information is important for estimating the optimal and economically cost-effective donor size and likelihood of obtaining appropriately matched cord blood units for Chinese patients awaiting haematopoietic stem cell transplantation. The data are available in the Allele Frequencies Net Database under the population name ''Hong Kong Chinese Cord Blood Registry'' and the identifier (AFND003358).

HLA-A, -B, -C, and -DRB1 genotyping and haplotype frequencies for a Hong Kong Chinese population of 7595 individuals.

HLA-A, -B, -C and -DRB1 gene and haplotype frequencies have been calculated from 7595 southern Chinese unrelated donors in a Hong Kong Bone Marrow Donor Registry. This is the first large-scale paper to report the distribution of A-C-B-DRB1 alleles in Hong Kong Chinese. This information is important for phylogenetic, comparative studies and estimating the optimal and cost-effective donor size and likelihood of obtaining appropriately matched donors for Chinese patients awaiting haematopoietic stem cell transplantation. The allele and haplotype data are available in the Allele Frequencies Net Database under the population name ''Hong Kong Chinese BMDR'' and the identifier (AFND003357).

A metapopulation model with Markovian landscape dynamics.

We study a variant of Hanski's incidence function model that allows habitat patch characteristics to vary over time following a Markov process. The widely studied case where patches are classified as either suitable or unsuitable is included as a special case. For large metapopulations, we determine a recursion for the probability that a given habitat patch is occupied. This recursion enables us to clarify the role of landscape dynamics in the survival of a metapopulation. In particular, we show that landscape dynamics affects the persistence and equilibrium level of the metapopulation primarily through its effect on the distribution of a local population's life span.

Identification of a novel HLA-A*02:06:01:02 allele in a Chinese individual by sequence-based typing.

The new HLA-A*02:06:01:02 allele differs from HLA-A*02:06:01 by a C→G substitution in Intron 1.

Neural stem cells harvested from live brains by antibody-conjugated magnetic nanoparticles.

It stems from the magnetism: The extraction of stem/progenitor cells from the brain of live animals is possible using antibodies conjugated to magnetic nanoparticles (Ab-MNPs). The Ab-MNPs are introduced to a rat's brain with a superfine micro-syringe. The stem cells attach to the Ab-MNPs and are magnetically isolated and removed. They can develop into neurospheres and differentiate into different types of cells outside the subject body. The rat remains alive and healthy.