Objective Recent findings indicate that the serological and biochemical characteristics of porcine erythrocytes share many similarities with human red blood cell (hRBC). Scientists believed that humanized porcine red blood cells (pRBC) could be used as one alternative source for human blood transfusion. Methods In order to eliminate ?Gal antigen and non-?Gal on the surface of pRBC, recombinant soybean ?-Galactosidase (rS?-GalE) constructed by our lab was used to remove terminal ?Gal residues from ?Gal antigen, and mPEG-BTC was used to camouflage non-?Gal xenoantigen on the surface of pRBC. Results The carbohydrate structures of ?Gal xenoantigen of pRBC treated with rS?-GalE were completely modified. The antigenic determinants of ?Gal and non-?Gal xenoantigen on the surface of pRBC were successfully camouflaged through mPEG-BTC modification. But this modification needed higher concentration of mPEG-BTC which could cause slight structure damage. Considering this, with combination of ?Gal xenoantigen conversion by rS?-GalE and chemical camouflage of non-?Gal xenoantigen with lower concentration of mPEG-BTC, the antigenic determinants of pRBC were attenuated and hemagglutination were diminished.Conclusion The morphology, structures, functions and deformability of pRBC modified with rS?-GalE, mPEG-BTC and rS?-GalE+ mPEG-BTC were normal.

Objective: Soy products may cause excessive intestinal gas because of soybean oligosaccharides . The effect of recombinant ?-galactosidase on eliminating mouse flatus was observed. Methods:The mouse model of flatulence was set up by ig raffinose and stachyose and the flatulence was investigated by measuring intestinal flatulent volume. Oligosaccharides were examined by TLC test and soybean protein was examined by SDS-PAGE. Results: Raffinose and stachyose can result in mouse flatus and recombinant ?-galactosidase can eliminate it without any effect on soybean protein. Conclusion: Recombinant ?-galactosidase can eliminate flatus, and be used as food additive.

In order to realize standardization and automatization,it necessary to develop a device for B→O blood conversion.This paper emphasizes on the control system of B→O blood conversion device,including software and hardware design,which provides a safe and rapid method for B→O blood conversion.

B→O blood conversion has very important meanings in the blood transfusion during the period of peace and war.In the leader of Professor Zhang Yangpei,from Academy of Military Medical Sciences,B→O blood conversion has been achieved by using gene engineering.They obtained the great breakthrough in the domain of blood type conversion.In order to realize standardization and automatization,it is necessary to develop a device applying to B→O blood conversion.This device automatically accomplishes the process of B→O blood conversion,shortens the time of B→O blood conversion to quarter than the time by manual operation,and ensures the standardization and obturation.In the condition of one-off pipeline,this device meets the clinical demands for blood,and lays a foundation for clinical expansion of B→O blood conversion.This paper presented the control system of B→O blood conversion device,including design of software and hardware.This device provides a safe and efficient tool for B→O blood conversion.

OBJECTIVEThis investigation aimed to examine how buccal mucosa microbiome succeeds in a healthy population with different ages and dentition stages.

METHODSTwenty-five subjects were recruited and subdivided into five groups: primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group. Individual mucosal microbiota was obtained by gently scraping both sides of the buccal mucosa with a cotton swab. Microbial diversity was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE).

RESULTS1) The composition of buccal mucosa microbiota has great intra-individual divergence. 2) The average band numbers of the primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group were 21.2 +/- 4.0, 17.8 +/- 3.9, 15.8 +/- 4.3, 16.8 +/- 3.7, and 22.2 +/- 6.5, respectively. No between-group differences was observed (P > 0.05), indicating that predominant strains in the oral cavity may be stable throughout an individual's lifetime. 3) The Shannon indices of primary dentition group, mixed dentition group, adolescent group, adult group, and elderly group were 1.73 +/- 10.2, 1.43 +/- 0.1, 1.05 +/- 0.2, 1.45 +/- 0.2, and 1.63 +/- 0.3, respectively. A significant between-group difference was observed (P = 0.003), indicating that the microbial diversity of the buccal mucosa decreases from childhood through adolescence, but increases from adult through senescence. 4) The clustering analysis showed that most of the samples in the same group clustered together, indicating higher intra-group community structure similarity.

CONCLUSIONComposition of the buccal mucosa microbiota was different among age groups. Adolescence may be an essential turning point of microbial ecology succession throughout life.

Adolescent ; Adult ; Aged ; DNA, Bacterial ; Humans ; Microbiota ; Mouth Mucosa ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S

Objectives:To establish hybridomas secreting monoclonal antibodies(McAbs) against O6-methylguanine-DNA methyltransferase(MGMT) and to observe the relationship between MGMT expression and clinical responses to ACNU and BCNU in human brain tumors.Methods:The hybridomas were established by cell fusion.MGMT expression in 60 glioma specimens was detected by means of immunohistochemical assay.Results: Seven hybridomas secreting McAbs against MGMT were obtained.Thirty tumor specimens had no detectable or low level of MGMT expression(Mer-), while 30 specimens had high level of MGMT expression(Mer+). The Mer- patients showed more sensitive to ACNU and BCNU than the Mer+ patients.Conclusions: The high specific hybridomas secreting monoclonal antibodies(McAbs) against MGMT were established.The preliminary study indicated that MGMT negative tumors were sensitive to ACNU and BCNU, whereas MGMT positive ones were more resistant to nitrosourea drugs.

OBJECTIVETo explore the strategies which reduce the amount of xenoantigen Galalpha1,3Gal.

METHODSHuman alpha-galactosidase gene and alpha1,2-fucosyltransferase gene were transferred into cultured porcine vascular endothelial cells PEDSV.15 and human alpha-galactosidase transgenic mice were produced. The Galalpha1,3Gal on the cell surface and susceptibility of cells to human antibody-mediated lysis were analyzed.

RESULTSHuman alpha-galactosidase gene alone reduced 78% of Galalpha1,3Gal on PEDSV.15 cell surface while human alpha-galactosidase combined with alpha1,2-fucosyltransferase genes removed Galalpha1,3Gal completely. Decrease of Galalpha1,3Gal could reduce susceptibility of cells to human antibody-mediated lysis, especially during co-expression of alpha-galactosidase gene and alpha1,2-fucosyltransferase gene. RT-PCR indicated positive human alpha-galactosidase gene expression in all organs of positive human alpha-galactosidase transgenic F1 mice including heart, liver, kidney, lung, and spleen, the amount of Galalpha1,3Gal antigens on which was reduced largely. 58% of spleen cells from F1 mice were destroyed by complement-mediated lysis compared with 24% of those from normal mice.

CONCLUSIONSHuman alpha-galactosidase gene and alpha1,2-fucosyltransferase gene effectively reduce the expression of Galalpha1,3Gal antigens on endothelial cell surface and confers resistance to human serum-mediated cytolysis. The expression of human alpha-galactosidase in mice can also eliminate the Galalpha1,3Gal antigens in most tissues and decrease the susceptibility of spleen cells to human serum-mediated cytolysis.

Animals ; Antigens, Heterophile ; metabolism ; Cell Death ; Cells, Cultured ; Disaccharides ; metabolism ; Endothelial Cells ; metabolism ; Fucosyltransferases ; genetics ; metabolism ; Graft Rejection ; genetics ; Humans ; Mice ; Mice, Transgenic ; Spleen ; cytology ; Swine ; Transfection ; alpha-Galactosidase ; genetics ; metabolism