Nonsteaming method improves the nutritional value and utilization efficiency of silkworm artificial diets.

Artificial diets for silkworms overcome the seasonal limitations of traditional rearing methods with fresh mulberry leaves. However, the current wet artificial diets, steamed at high temperatures, are not favored by silkworms, and they are cumbersome and challenging to preserve. These conditions adversely affected the development of artificial diet-based sericulture production. In this study, we disinfected dry powder diets with radiation and added distilled water without steaming before use. Then, the nutritional value of finished diets and their impact on silkworm development was assessed. Compared with steamed diets, nonsteamed diets were more attractive to silkworms. Chemical assays showed significantly more essential nutrients for silkworms, including l-ascorbic acid, vitamin B1, vitamin B2, and urease in nonsteamed diets than in steamed diets. Feeding fifth-instar silkworm larvae with nonsteamed diets significantly improved the ammonia utilization efficiency of the diet and increased the cocoon shell rate and diet/silk protein conversion efficiency by 5.9% and 13.3%, respectively. When fed with nonsteamed diets, the abundance of aerobic microorganisms in silkworm intestines increased and the abundance of pathogenic bacteria decreased. Furthermore, the vitality of the silkworm, measured by the dead worm cocoon rate, significantly improved by 16.90%. In summary, preparing sterile wet diets without high-temperature steaming effectively improved the nutritional value of the diet and enhanced silkworm growth.

Human umbilical cord mesenchymal stem cell-derived exosomes act via the miR-1263/Mob1/Hippo signaling pathway to prevent apoptosis in disuse osteoporosis.

Disuse osteoporosis (DOP) is a common complication resulting from the lack of or disuse of mechanical loading and has been unsatisfactorily treated. We hypothesized that exosomes derived from human umbilical cord mesenchymal stem cells (HUCMSCs) could reduce bone marrow mesenchymal stem cell (BMSC) apoptosis in rat DOP via the miR-1263/Mob1/Hippo signaling pathway. To evaluate the function of exosomes derived from HUCMSCs (HUCMSC-Exos) in DOP, hind limb unloading (HLU)-induced DOP rat models were prepared. In vitro, the proliferation of BMSCs were evaluated using CCK-8 assays. Further, the apoptosis of BMSCs were evaluated using annexin V-FITC assay and Western blots. In vivo, the protective effects of HUCMSC-Exos were evaluated using HE staining and microCT analysis. The underlying molecular mechanism of exosome action on BMSC apoptosis through the miR-1263/Mob1/Hippo pathway was also investigated by high-throughput RNA sequencing, luciferase reporter assays, RNA-pull down assays and Western blots. The RNA-seq and q-PCR results showed that the level of miR-1263 was most abundant among differentially expressed microRNAs. Exosomal miR-1263 could bind to the 3'untranslated region (3' UTR) of Mob1 and exert its function by directly targeting Mob1 in recipient cells. The inhibition of Mob1 could activate YAP expression. Hippo inhibition reversed the in vitro HLU-induced apoptotic effect on BMSCs. The microCT and HE staining results indicated that HUCMSC-Exos ameliorated DOP in vivo. Exosomes derived from HUCMSCs are effective at inhibiting BMSC apoptosis and preventing rat DOP. This mechanism is mediated by the miR-1263/Mob1/Hippo signaling pathway.

Structure-based engineering of heparinase I with improved specific activity for degrading heparin.

BACKGROUND: Heparinase I from Pedobacter heparinus (Ph-HepI), which specifically cleaves heparin and heparan sulfate, is one of the most extensively studied glycosaminoglycan lyases. Enzymatic degradation of heparin by heparin lyases not only largely facilitates heparin structural analysis but also showed great potential to produce low-molecular-weight heparin (LMWH) in an environmentally friendly way. However, industrial applications of Ph-HepI have been limited by their poor yield and enzyme activity. In this work, we improve the specific enzyme activity of Ph-HepI based on homology modeling, multiple sequence alignment, molecular docking and site-directed mutagenesis. RESULTS: Three mutations (S169D, A259D, S169D/A259D) exhibited a 50.18, 40.43, and 122.05% increase in the specific enzyme activity and a 91.67, 108.33, and 75% increase in the yield, respectively. The catalytic efficiencies (kcat/Km) of the mutanted enzymes S169D, A259D, and S169D/A259D were higher than those of the wild-type enzyme by 275, 164, and 406%, respectively. Mass spectrometry and activity detection showed the enzyme degradation products were in line with the standards of the European Pharmacopoeia. Protein structure analysis showed that hydrogen bonds and ionic bonds were important factors for improving specific enzyme activity and yield. CONCLUSIONS: We found that the mutant S169D/A259D had more industrial application value than the wild-type enzyme due to molecular modifications. Our results provide a new strategy to increase the catalytic efficiency of other heparinases.

Custom-made Prosthesis for Reconstruction after Radical Resection for Chondrosarcoma of Manubrium.

The clinical incidence of tumors in the manubrium is not high. Regardless of whether the tumor is primary or metastatic, the tumor should be completely removed as long as the patient is able to tolerate the surgery. This procedure can lead to sternal defects. Deciding on the method of defect reconstruction is a critical problem that clinicians face. In this , to reduce the limitations of the patient's upper body movement after surgery due to the inflexibility in the connections of the sternal prosthesis, we created a prosthesis using a computer-assisted design method and a 3-D technique, to completely preserve the agility of the sternum and maximize the patient's post-operational movement. The method used in the present study takes into consideration the individual's chest anatomy, sternum stress, and many other biological characteristics. Care is taken to measure the sternum size accurately, to provide personalized treatment, to accomplish precise results, and to reduce potential future damage. The patient's shoulder function was improved following the procedure.

Two decades of voluntary nonremunerated blood donation in Shenzhen, China.

BACKGROUND: As an emerging metropolis with population expansion from 2 million to 10 million from 1993 to 2012, the clinical demand for blood in Shenzhen has increased 20 times. To deal with this big challenge, Shenzhen utilized voluntary nonremunerated blood donation (VNRBD) in 1993 for the first time in China. After two decades of efforts, Shenzhen has achieved self-sufficiency in its blood supply and guaranteed its blood security by nonpaid blood donation. STUDY DESIGN AND METHODS: We summarized the strategies to achieve self-sufficiency and security in the blood supply in Shenzhen during two decades, including the legal construction of VNRBDs and the continuously improving strategies to recruit and retain nonpaid donors. The collection data of whole blood (WB) and apheresis platelet (PLT) donations were retrieved, and donor demographic and donation characteristics were analyzed. RESULTS: From 1993 to 1998, paid and nonpaid blood donations coexisted in Shenzhen. From the year 1999, all WB for clinical use came from VNRBDs. From 1999 to 2012, the donors who chose to donate 400 mL each time and repeat and regular donors increased sharply to meet the fast growth of clinical demand. From the year 2005, the clinical demand for PLTs was entirely satisfied by nonpaid donations. CONCLUSIONS: After two decades of practice, we believe that the legal regime of VNRBD is fundamental guarantee for long-term self-sufficiency and security in the blood supply. In addition, strengthening the publicity to improve the public's awareness and improving donation services and measures to recruit more nonpaid donors and retain repeat and regular donors are very important.

[An analysis of the reason for HLA-C allele dropout in five samples by sequence-based typing].

OBJECTIVE: To analyze the possible reason for HLA-C allele dropout in routine sequence-based typing (SBT) and improve the accuracy of HLA-C SBT test. METHODS: A total of 620 randomly selected samples from healthy voluntary blood donors in Shenzhen were typed at HLA-C locus by sequence-based typing using the AlleleSEQR HLA-C plus sequence-based typing kit. Samples with no full match result were subjected to cloning and haplotype sequencing of the full-length HLA-C gene. If no novel mutations were found, samples were then retyped, using our self-designed PCR primer pair and PCR conditions replacing the AlleleSEQR HLA-C PCR reagents in the PCR set-up procedure so as to analyze the potential reasons for causing abnormal SBT result. RESULTS: In the 620 samples typed at HLA-C locus using the AlleleSEQR HLA-C SBT commercial kit, 5 samples with no full match result were identified. The closest genotype showed one nucleotide mismatch with many different allele groups at different nucleotide position. Based on the PCR-SBT nucleotide sequence, heterozygous nucleotides were determined only in exon 4, whereas the nucleotides in exon 2 and 3 were all homozygotes. The results showed that HLA-Cw*0706 allele dropout existed in all the 5 samples with abnormal SBT results initially identified by AlleleSEQR HLA-C SBT kit, no novel mutation was found. CONCLUSION: The results indicate that the PCR primer pair incompatible with DNA template may result in allele dropout in HLA-C SBT test. Based on the characterization of HLA-C full-length, it is essential to develop HLA-C SBT kit suitable for Chinese population in the future.

[Establishment of an assay for cloning and sequencing the full-length HLA-Cw gene].

OBJECTIVE: To establish a reliable assay for cloning and sequencing the full-length HLA-Cw gene. METHODS: In this study, a fragment of 4.5 kb full-length HLA-Cw gene was amplified using the self-designed PCR primer pair by long template PCR, purified PCR products was cloned into the pGEM-Teasy plasmid vector and the plasmid DNA isolated from positive clones was subjected to haplotype sequencing by both directions. A total of 12 samples having been previously-genotyped by PCR sequence-based-typing (PCR-SBT) were amplified by using the TaKaRa LA Taq and Stratagene Pfu polymerase, respectively. PCR products of full length HLA-Cw gene were subjected to cloning and sequencing and the obtained haplotype sequence were compared with the PCR-SBT results. RESULTS: The specific target fragment of HLA-Cw gene could be amplified and the full-length HLA-Cw allele sequence covering from nucleotide position -962 in 5'untranslated region (5'-UTR) to nucleotide position 3576 in downstream area of 3'-UTR region could be obtained using our method. The results of cloning and sequencing analysis indicated that the Stratagene Pfu polymerase had better fidelity than the TaKaRa LA Taq polymerase in this experiment. By comparing the sequences of Cw*07020101 with Cw*010201, 11 SNPs as well as 2 insertions/deletions in nt-962--284 of 5'-UTR, and 11 SNPs as well as 1 insertion/deletion in nt3067-3576 downstream of 3'-UTR were identified. CONCLUSION: Our results indicate that the technique for cloning and sequencing full-length HLA-Cw gene has been established, it has a broad application in full-length HLA-Cw gene polymorphism study and the regulation and expression of HLA-Cw gene.

Polymorphic analysis of the Lutheran blood group system in Chinese.

The Lutheran blood group is a complex system consisting of 19 identified antigens. It belongs to the immunoglobulin family of receptors and adhesion molecules. Four pairs of antigens show allelic relationships while other antigens are of very high incidence. In this study, we performed genetic polymorphism analyses by molecular techniques of the Lutheran blood group system in Chinese subjects. Blood samples were collected from randomly-selected healthy donors and analyzed by PCR-RFLP or SBT methods. LU1/2(Lu(a)/Lu(b)), LU6/9, LU8/14, and LU18/LU19(Au(a)/Au(b)) antigen polymorphisms were detected as follows: 1102 individuals were diagnosed as Lu(a-b+) type; 117 individuals were all LU(6+9-) genotypes; 119 individuals were all LU(8+14-) genotypes. Among 368 individuals, 278 showed homozygous nt1615A, 6 showed homozygous nt1615G, and 84 showed nt1615A/G heterozygosity. The gene frequencies of Au(a) and Au(b) in Chinese subjects were 0.8695 and 0.1304 respectively. A novel allele was identified in 4 Lu(18+19-) phenotype cases from 3 families.

[Application of 17 Y-chromosome specific STR loci in paternity testing].

The purpose of this study was to explore the ability of discrimination of the AmpFlSTR Yfiler PCR amplification kit containing 17 Y-STR loci and the allelic mutation in the practice of paternity testing in Chinese population. 36 non-paternity father/son pairs and 84 confirmed father/son pairs, which had been previously genotyped by using Reliagene Y-PLEX 6 commercial kit and the "9 Y-STR multiplex with reduced-size amplicons" developed by our laboratory, were subjected to Y-STR genotyping at 17 loci using the AmpFlSTR Yfiler PCR amplification kit. 17 Y-STR loci were amplified in single multiplex and the PCR products were detected by using ABI Prism 3100 DNA Sequencer. The number of Y-STR exclusion for each non-paternity father/son pair and the mutation events for each confirmed father/son pair were calculated and the observed results were compared with our previous reported data determined by Reliagene Y-PLEX 6 kit and the "9 Y-STR multiplex with reduced-size amplicons". The results showed that out of 36 non-paternity father/son pairs subjected to Y-STR genotyping by using the AmpFlSTR Yfiler kit, one case with no Y-STR exclusion of paternity and 35 cases with more than 3 Y-STR exclusions for each father/son pair were observed. The percentage of cases with more than 3 Y-STR exclusions in all the tested non-paternity cases for Yfiler kit was 97.22% (35/36), which was more than that of Reliagene Y-PLEX 6 kit (92.11%, 35/38) and our "9 Y-STR multiplex with reduced-size amplicons" (91.67%, 33/36). Except for single father/son pair with no Y-STR exclusion, an average of 11.3 Y-STR exclusions was observed in other 35 non-paternity father/son pairs. In the 84 confirmed father/son pairs, 5 mutation events with a single unit repeat change at DYS437, DYS439, DYS635, DYS389II and DYS19, respectively, were identified using the Yfiler kit. The average mutation rate was estimated at 3.50 x 10(-3) per locus per generation. The cases with Y-STR mutation events in all tested confirmed father/son pairs for Yfiler system were 5.95% (5/84), which was significantly higher than that of Y-PLEX 6 (2.15%, 2/93) and "9 Y-STR multiplex with reduced-size amplicons" (no mutation events in the same 84 confirmed father/son pairs). It is concluded that the Yfiler kit which allowing simultaneous analysis of 17 Y-STR loci offers a high ability of discrimination for paternity testing, however, the Y-STR allelic mutation of the Yfiler system can not be neglected.

Genotyping of samples lacking expected antibodies in ABO blood group.

We report nine donations with ABO inconsistency in reverse typing caused by partly or entirely missing antibodies. A and B antigens and antibodies were examined by serological blood typing, and ABO deoxyribonucleic acid (DNA) analyses were performed by sequence-specific priming and sequencing. A B101 allele was demonstrable in a case with O phenotype. The molecular mechanisms in deficiency of natural ABO antibody could be partly clarified. The ABO genotyping technique is an accurate method for determining the blood samples involved in ABO grouping discrepancies and is a valuable complement to serology for correct determination of donor blood status. The mechanisms involved in the absence of potent natural antibodies directed against A and B antigen lacking on an individual's own red cell membranes remain to be further investigated.

[Molecular genetic analysis of Diego blood group Dia and Dib in Chinese Han population].

OBJECTIVE: To study the molecular genetic background of Diego blood group in Chinese Han population. METHODS: A total of 2990 blood samples from unrelated blood donors were phenotyped for Dia and Dib by serological method. Twenty randomly selected samples of Di(a-b+) type and all of the samples of rare Di(a+b-) phenotype by screening were genotyped by PCR-SSP and direct DNA Sequencing. RESULTS: Of the 2990 samples identified by serological method, 2821 were Di(a-b+), 167 were Di(a+b+) and 2 were Di(a+b-). All of the 20 randomly-selected samples with Di(a-b+) phenotype were DI2DI2 homozygote by PCR-SSP genotyping, with nucleotide C at nt position 2561 in exon 19 by direct sequencing of the DI gene. The 2 samples of rare Di (a+b-) phenotype were both the DI1DI1 homozygote, with nucleotide T at nt position 2561 in exon 19. CONCLUSION: Our results indicate that the expression of Dia and Dib antigens in Chinese Han population most likely result from a single nucleotide T to C substitution at nucleotide position 2561 in exon 19 of the DI gene, which subsequently leads to an amino acid 854 change from Pro to Leu.

[Genetic status of a AB chimeric blood group family].

In order to study the genetic status of a rare chimeric family, some samples of A(3)B(3) family were identified by sequencing of ABO gene; flow-rSSO and PCR-SSP were used to detect loci of HLA-A, B, DRB1 genes, and multiplex amplifying with fluorescence-dye were performed for 16 short tandem repeat (STR) loci. The results indicated that two individuals from A(3)B(3) family contained more than two alleles at ABO gene, HLA-B, DRB1 and some STR loci. In conclusion, analysis of chimeric blood group by using genotyping techniques clearly demonstrating genetic status of this rare chimeric blood group promotes further elucidation of the existing state of specific genetic status.

[Effect of platelet CD42a modification by mPEG-SPA with different molecular masses].

OBJECTIVE: To observe the effect platelet antigen modification by mPEG-SPA with different molecular masses. METHODS: Platelet CD42a was modified by 5 kD and 20 kD mPEG-SPA, respectively, and the fluorescence intensity of CD42a was detect by flow cytometry and the three-dimensional structure of CD42a simulated to analyze the distribution of lysine in CD42a molecule. RESULTS: After platelet CD42a modification by 5 kD and 20 kD mPEG-SPA, the fluorescence intensity of CD42a decreased sharply by 85.54% and 88.65%, respectively, and multiple lysine regions were identified on the surface of CD42a molecule. CONCLUSION: Both 5 kD and 20 kD mPEG-SPA allow useful modification of platelet CD42a, but 20 kD mPEG-SPA is more advantageous than 5 kD mPEG-SPA.

Molecular polymorphism of O alleles in the Chinese Han population.

The ABO blood group system is the most important in transfusion medicine. O blood group is common in Chinese Han people, but the distribution of various O alleles is unknown. Sequences of exon6 and exon7 of the O allele at the ABO gene locus were studied in 100 individuals of the O phenotype randomly selected from the Chinese Han population. Some samples, when required, were cloned and sequenced spanning exon6 and exon7. Eight O alleles were found in the Chinese population. Most have the 2 common O01 or O02 alleles. The allele frequency of ABO*O01 was 0.47, and that of ABO*O02 was 0.495. One individual was found to have O05 allele. Five alleles were found to differ from all alleles reported to date. Four of these alleles differed from either the O01 allele (1 out of 4) or O02 allele (3 out of 4) by 1 point mutation at A468G, G489A, T526C, or T1104G. The fifth allele differed from the O01 allele since it does not have nt261G deletion but has C467T mutation. This novel allele occurred in 2 individuals. O genetic analysis suggests that the O01 allele prevails, with O1v accounting for about 97% of these in the Chinese Han population. The O03 allele that has been shown to occur with a frequency of <5% in other populations was not detected. But the novel O allele without 261G deletion has been found in Chinese for the first time. Surely more O alleles will be found in the Chinese population.