AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-a (TNF-a) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyz...AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-a (TNF-a) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyze the geneenvironment interaction between -238G/A polymorphism and cigarette smoking or alcohol consumption. METHODS: A case-control study was conducted to analyze the association of TNF-a gene promoter polymorphism with HBV infection outcomes. A total of 207 patients with chronic hepatitis B (HB) and 148 cases of self-limited HBV infection from Ditan Hospital and Shunyi District Hospital in Beijing, respectively were recruited. History of smoking and alcohol drinking was inquired by a questionnaire. The -238G/A polymorphism of TNF-a gene promoter was genotyped by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP). RESULTS: The frequencies of GG and GA genotypes were 98.07% and 1.93% in chronic HB patients and 93.24% and 6.76% in self-limited HBV infection individuals, respectively (X^2=5.30, P=-0.02). The frequency of G allele was significantly higher in patients with chronic HB that in individuals with self-limited HBV infection (99.03% vs 96.62%, X^2=5.20, P=0.02). Only modestly increased risk of onset of chronic HB was found in smokers (OR=1.40, 95% CI： 0.87-2.28, P=0.14) and drinkers (OR=-1.26, 95%CI： 0.78-2.05, P=-0.32). There was a positive interaction between genotype GG and cigarette smoking with an interaction index (Ⅱ) of 2.95, or alcohol consumption with an Ⅱ of 1.64. CONCLUSION: The -238G/A polymorphism of TNF-a gene promoter region is independently associated with different outcomes of HBV infection.展开更多
The nueleocapsid (N) protein of severe acute respiratory syndrome-coronavirus (SARS-CoV) is a major virion structural protein. In this study, two epitopes (Nl and N2) of the N protein of SARS-CoV were predicted by bio...The nueleocapsid (N) protein of severe acute respiratory syndrome-coronavirus (SARS-CoV) is a major virion structural protein. In this study, two epitopes (Nl and N2) of the N protein of SARS-CoV were predicted by bioinformatics analysis. After immunization with two peptides, the peptides-specific antibodies were isolated from the immunized rabbits. The further experiments demonstrated that N1 peptide-induced polyclonal antibodies had a high affinity to bind to E. coli expressed N protein of SAR,S-CoV. Furthermore, it was confirmed that Nl peptide-specific IgG antibodies were detectable in the sera of severe acute respiratory syndrome (SARS) patients. The results indicated that an epitope of the N protein has been identified and N protein specific Abs were produced by peptide immunization, which will be useful for the study of SARS-CoV.展开更多
Objective To expatiate dynamic changes in hamsters infected with scrapie strain 263K, to observe the presence and aggravation of various forms of PrP and PrPSc during incubation period, and to probe primarily the rela...Objective To expatiate dynamic changes in hamsters infected with scrapie strain 263K, to observe the presence and aggravation of various forms of PrP and PrPSc during incubation period, and to probe primarily the relationship between the onset of clinic manifestations and the presence of different PrPSc forms. Methods Hamster-adapted scrapie strain 263K was intracerebrally inoculated into hamsters. Different forms of PrP and PrPSc were monitored dynamically by Western blot and immuno-histochemical assays. The presence of scrapie-associated fibril (SAF) was assayed by electron microscopy analysis (EM) and immune-golden EM. Results PrPSc was initially detected in the brain tissues of the animals in 20 days post-inoculation by immunohistochemistry and 40 days with Western blot. Quantitative evaluations revealed that the amounts of PrP and PrPSc in brain tissues increased along with the incubation. Several high and low molecular masses of PrP were seen in the brains of the long-life span infected animals. Deglycosylation assays identified that the truncated PrP in the infected brains showed similar glycosylation patterns as the full-length PrP. The presence of short fragments was seemed to relate with the onset of clinical conditions. Conclusion These results indicate that infectious agents exist and accumulate in central nerve system prior to the onset of the illness. Various molecular patterns of PrPSc may indwell in brain tissues during the infection.展开更多
AIM: To describe the mortality rate of pancreatic cancer and its distribution in China during the period of 1991-2000.METHODS: Based on the data of demography and death collected through China′s Disease Surveillance ...AIM: To describe the mortality rate of pancreatic cancer and its distribution in China during the period of 1991-2000.METHODS: Based on the data of demography and death collected through China′s Disease Surveillance Point System (DSPS) over the period of 1991-2000, the distribution of death rate of pancreatic cancer was described in terms of age group, gender, calendar year, rural/urban residence and administrative district.RESULTS: A total of 1 619 death cases attributed to pancreatic cancer (975 men and 644 women) were reported by DSPS during 1991-2000. The reported, adjusted and agestandardized mortality rates increased from 1.46, 1.75, and 2.18 per 100 000 populations in 1991 to 2.38, 3.06, and 3.26per 100 000 populations in 2000. The majority (69.62 %) of the deaths of pancreatic cancer were seen in the age group of 60 years and older. The mortality rate was higher in men than in women, but the male to female death rate ratios decreased during the 10 years. Our data also showed that the death rate of pancreatic cancer in urban areas was about 2-4 fold higher than that in rural areas, and in Northeast and East China, the death rates were higher than those in the other 5 administrative districts.CONCLUSION: The death rate due to pancreatic cancer was rising during the period of 1991-2000 and the peak mortality of pancreatic cancer might arrive in China.展开更多
Objective To investigate the association of specific functional gene ACE (I/D) variants of the renin-angiotensin system with essential hypertension (EH) and interaction between ACE (I/D) gene and risk factors for EH i...Objective To investigate the association of specific functional gene ACE (I/D) variants of the renin-angiotensin system with essential hypertension (EH) and interaction between ACE (I/D) gene and risk factors for EH in a genetically homogenous Mongolia rural population of China. Methods Individuals (n=1099) were recruited from general population of Kezuohouqi Banner in Inner Mongolian Autonomous Region. Results The association was found between ACE genotype DD plus ID and EH, with an interaction between ACE genotype DD plus ID and cigarette smoking in an additive model. Cigarette smoking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 7.10 to 1.16. Interaction between ACE genotype DD plus ID and alcohol drinking on EH appeared an additive model. Alcohol drinking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 1.66 to 1.09. BMI and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 6.15 to 2.49. Interactions between ACE genotype and WHR on EH showed a multiplicative model. In a short, there was an interaction between ACE gene and cigarette smoking, alcohol drinking and BMI on EH, especially in a low dose-exposure effect Conclusion It is important for individuals who carry ACE D allele gene to prevent EH, and furthermore, to prevent and control coronary heart disease, in a view of population-based prevention.展开更多
Objective To understand the infectious characteristics of a hamster-adapted scrapie strain 263K with five different routes of infection including intracerebral (i.e.), intraperitoneal (i.p.), intragastrical (i.g.), in...Objective To understand the infectious characteristics of a hamster-adapted scrapie strain 263K with five different routes of infection including intracerebral (i.e.), intraperitoneal (i.p.), intragastrical (i.g.), intracardiac and intramuscular (i.m.) approaches. Methods Hamsters were infected with crude- or fine-prepared brain extracts. The neuropathological changes, PrPSc deposits, and patterns of PK-resistant PrP were analyzed by HE stain, immunohistochemistry (IHC) assay and Western blot. Reactive gliosis and neuron loss were evaluated by glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) specific IHC. Results The animals inoculated in i.m. and Lp. ways with crude PrPSc extracts showed clinical signs at the average incubation of 69.212.8 and 65.5±3.9 days. Inoculation in i.c. and intracardiac ways with fine PrPSc extracts (0.00035 g) caused similar, but relative long incubation of around 90 days. Only one out of eight hamsters challenged in i.g way with low dosage (0.01 g) became ill after a much longer incubation (185 d), while all animals (4/4) with high dosage (0.04 g) developed clinical signs 105 days postinfection. The most remarkable spongiform degeneration and PrPSc deposits were found in brain stem among the five challenge groups generally. The number of GFAP-positive astrocytes increased distinctly in brain stems in all infection groups, while the number of NSE-positive cells decreased significantly in cerebrum, except i.c. group. The patterns of PK-resistant PrP in brains were basically identical among the five infection routes. Conclusion Typical TSE could be induced in hamsters by inoculating strain 263K in the five infection ways. The incubation periods in bioassays depend on infective dosage, administrating pathway and preparation of PrPSc. The neuropathological changes and PrPSc deposits seem to be related with regions and inoculating pathways.展开更多
Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by sin...Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.展开更多
Objective To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. Methods We developed a JAVA program for searching sho...Objective To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. Methods We developed a JAVA program for searching short exact sequence matches at C-terminus. According to the known C-termini, which PDZ domains recognized experimentally, Swissprot database has been searched by this program for all potential ligands. Results Some PDZ domains may have more potential ligand proteins, which are undiscovered yet experimentally. These bioinformatic results also provide clues for studying functions of hypothetical proteins and PDZ domains’ protein interactions in many different organisms. Conclusion The results may provide useful clues for discovering potential functions of hypothetical proteins and new functions of known proteins.展开更多
The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart ...The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart disease (CHD) and 100 healthy individuals selected from Chinese Han nationality.Twelve segregating alleles (3’β29 -51) were observed in the pooled total of 203 subjects. The most common allele was 3’β 37. followed by 3’β39 with frequencies of 0. 362 and 0. 296, respectively. This model of allele distribution was coincident with the results form different ethnic groups, but the relative frequencies of alleles were different. In comparison with the allele frequencies between the patients and controls,alleles bigger than 3’β39 (3’VNTR-B) were significantly more common among the patients than among the controls (P<0. 001). Moreover. in the CHD group patients with plasma levels of TC≥3.88 mmol/L,LDL-C≥2. 59 mmol/L and HDL-C<l. 16mmol/L had significantly higher frequencies of 3’ VNTR-B allele (P<0. 01). Therefore,it is suggested that 3’ VNTR-B allele might be involved in the development of coronary atherosclerosis, presumably through their influences on lipid metabolism.This study supported by “8. 5” grant from Ministry of PublicHealth.展开更多
Variable Charge X/Y (VCX/Y) is a human testis-specific gene family that localized on X and Y chromosomes. In this study, VCY protein was expressed in E. coli in the form of glutathione-S-transferase (GST) fusion prote...Variable Charge X/Y (VCX/Y) is a human testis-specific gene family that localized on X and Y chromosomes. In this study, VCY protein was expressed in E. coli in the form of glutathione-S-transferase (GST) fusion protein. With the purified fusion protein as antigen, the anti-GST-VCY antibody was generated and the localization of VCY protein in human testis was determined by immunohistochemistry. In the testis seminiferous epithelium. VCY proteins were highly expressed in nuclei of germ cells. Using propidium iodide staining and green fluorescent protein (GFP) tag technologies, VCY and VCX-8r proteins were mainly localized in the uucleoli of COST cells. In addition, the colocalization for VCY and VCX-8r in COS7 cells was also observed. With VCY cDNA as bait, a cDNA fragment of acidic ribosomal protein PO was obtained using yeast two-hybrid system. All the information above indicates that VCX/Y protein family might be involved in the regulation of ribosome assembly (hiring spermatogenesis.展开更多
The method of laser capture microdissection (LCM) combined with suppressive subtractive hybridization (SSH) was developed to isolate specific germ cells from human testis sections and to identify the genes expressed d...The method of laser capture microdissection (LCM) combined with suppressive subtractive hybridization (SSH) was developed to isolate specific germ cells from human testis sections and to identify the genes expressed during differentiation and development. In the present study, over 10,000 primary spermatocytes and round spermatid cells were successfully isolated by LCM. Using the cDNAs from primary spermatocytes and round spermatids, SSH cDNAs library of primary spermatocyte-specific was constructed. The average insert size of the cDNA isolated from 75 randomly picked white clones was 500 bp, ranging from 250 bp to 1.7 kb. Using the dot-blot method, a total of 421 clones were examined, resulting in the identification of 390 positive clones emitting strong signals. Partial sequence of cDNAs prepared from each clone was determined with an overall success rate of 84.4%. Genes encoding cytochrome c oxidase II and the rescue factor-humanin were most frequently expressed in primary spermatocytes, suggesting their roles involved in meiosis.展开更多
Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensin II type 1 receptor gene for essential hypertension in Tibetan. Methods A ca...Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensin II type 1 receptor gene for essential hypertension in Tibetan. Methods A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension. Results As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20.1) times higher than those with TT genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect. Conclusion Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.展开更多
Objective To investigate the distribution of single nucleotide polymorphisms (SNPs)in CAPN10 gene in Chinese population and their relation with type 2 diabetes mellitus inHan people of Northern China. Methods CA...Objective To investigate the distribution of single nucleotide polymorphisms (SNPs)in CAPN10 gene in Chinese population and their relation with type 2 diabetes mellitus inHan people of Northern China. Methods CAPN10 gene was sequenced to detect SNPs indifferent nationalities of China. Five SNPs were chosen to perform case-control study andhaplotype analysis in 156 normal Han people of Northern China and 173 type 2 diabetes. OneSNP was also analyzed with transmission-disequilibrium test (TDT) and sib transmission-disequilibrium test (STDT) in 68 type 2 diabetes pedigrees (377 people). Results A totalof 40 SNPs were identified in length of 8 936bp, with an average of 1 in every 223bp. TheSNPs in CAPN10 gene did not distribute evenly and the SNPs in Chinese were different fromthose reported in Mexican American. There was no significantly statistical difference in theallele frequency of the 5 SNPs between case and control, and the haplotype frequencies inthe two groups were not significantly different. No positive results was found in TDT andSTDT analysis. Conclusions The SNP distribution of CAPN10 gene differs in differentnationalities. The studied SNPs in CAPN10 gene may not be the major susceptibility onesof type 2 diabetes mellitus in Han people of Northern China.展开更多
Objective To investigate the molecular mechanism of atherosclerosis that related to age. Methods Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kap...Objective To investigate the molecular mechanism of atherosclerosis that related to age. Methods Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kappa B (NF-κB) and expression of platelet-derived growth factor B (PDGF-B) in smooth muscle cells (SMCs) co-cultured with low density lipoprotein (LDL), oxidized LDL (ox-LDL), and ox-LDL+high density lipoprotein (HDL) originated from rats of 2 and 10 months old respectively. Fat stain was used to identify the lipid intake in SMCs. Results The optimal stimulation time of ox-LDL to SMCs was 12 hours. NF-κB intensity increased in most nuclei of SMCs that originated from rats of either 2 or 10 months old co-cultured with ox-LDL. The intensity of NF-κB and the amount of intracellular lipid taken in SMCs were more obvious in cells from 10-month-old rats than from the younger ones. Change of PDGF-B expression in SMCs was not remarkable in each group of rats. Conclusions The 10-month-old rats are more susceptive to ox-LDL than 2-month-old rats in activating nuclear transloca- tion of NF-κB. Maybe this is one of the important reasons contributing to the difference between the older and younger rats on the initiation and development of atherosclerosis lesion. Expression of PDGF-B is not associated with the activity of nuclear translocation of NF-κB.展开更多
To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. Methods The assessment was made with various anticancer dr...To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. Methods The assessment was made with various anticancer drugs (adriamycin, mitomycin, cisplatinum and vincristine) that showed different cytotoxicities in transfectant HeLa cells with pSV-GT containing rat GST-pi cDNA (HeLa/pSV-GT) or control pSV-neo (HeLa/pSV-neo). Expression levels of GST-pi mRNA in HeLa/pSV-GT and HeLa/pSV-neo were measured by in situ hybridization using Digoxin-labelled cDNA probe. Results HeLa/pSV-GT expressed significantly high degree of GST-pi mRNA, whereas both HeLa/pSV-neo and HeLa cells had very low expression. Cytotoxicities of HeLa/pSV-GT and HeLa/pSV-neo with 4 anticancer drugs were measured by MTT assay. Drug concentrations for yielding 50% inhibition (IC50) in HeLa/pSV-GT by adriamycin, mitomycin and cisplatinum were 70.13 靏/mL, 10.95 靏/mL and 16.52 靏/mL, respectively. In contrast, IC50 in HeLa/pSV-neo was 10.34 靏/mL, 7.48 靏/mL and 13.70 靏/mL, respectively. The cytotoxicities of vincristine on both HeLa/pSV-GT and HeLa/pSV-neo were not significantly different. Conclusions Our findings suggest that HeLa/pSV-GT containing rat GST-pi cDNA is resistant to some anticancer drugs due to overexpression of GST-pi. Also, HeLa/pSV-GT cell line could serve as a useful cytogenetic model for further research.展开更多
AIM: To identify the susceptible gene (s) for type 2 diabetes in the prevousely mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotype...AIM: To identify the susceptible gene (s) for type 2 diabetes in the prevousely mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes.METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Hah ethical origin, to perform this casecontrol study. The haplotypes with significant difference in the gene (s) were further analyzed.RFSULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP,rs436045 in the protein kinase C/ζgene (PRKCZ) was statistically different between the case and control groups (P＜0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified.CONCLUSION: PRKCZgene may be associated with type 2 diabetes in Hah population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.展开更多
Objective To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase...Objective To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase chain reaction (DD-PCR) technique was used. cDNAs were synthesized by reverse transcription and amplified by PCR using 30 primer combinations. After being screened by dot blot analysis, differentially expressed cDNAs were cloned, sequenced and confirmed by Northern blot analysis. Results Eighteen differentially expressed cDNAs were cloned and sequenced, of which 17 were highly homologous to known genes (homology = 89%-100%) and one was an unknown gene. Northern blot analysis confirmed that eight genes encoding human zinc finger protein 217 (ZNF217), mixed-lineage kinase 3 (MLK-3), ribosomal protein (RP) L15, RPL41, RPS16, TBX3, stanniocalcin 2 (STC2) and mouse ubiquitin conjugating enzyme (UBC), respectively, were up-regulated, and three genes including human transforming growth factor b inducible gene (Betaig-h3), a-1,2-mannosidase 1A2 (MAN 1A2) gene and an unknown gene were down-regulated in the GMA-transformed cells. Conclusion Analysis of the potential function of these genes suggest that they may be possibly linked to a variety of cellular processes such as transcription, signal transduction, protein synthesis and growth, and that their differential expression could contribute to the GMA-induced neoplastic transformation.展开更多
Objective In order to explore the features of discrimination against people with HIV/AIDS in rural areas, a community-based intervention was carried out in two pilot communities of X County of Shanxi Province from Se...Objective In order to explore the features of discrimination against people with HIV/AIDS in rural areas, a community-based intervention was carried out in two pilot communities of X County of Shanxi Province from September 2002 to October 2003. Methods Data were collected using qualitative methods (in-depth interview and focus group discussion) and anonymously structured questionnaires. Results (1) Severe discrimination against people infected with HIV/AIDS was revealed in the target communities. However, the response to HIV/AIDS was different in each community. (2) People were reluctant to disclose their HIV status or get tested for HIV, which endangered their sexual partners to contract HIV through unprotected sexual intercourses. (3) Attitudes towards people infected with HIV/AIDS varied. (4) Public education promoted a better understanding of HIV/AIDS which in turn improved community attitudes and behaviors towards people with HIV/AIDS. Conclusion HIV/AIDS-related discrimination undermines both individuals and communities responses to HIV/AIDS and may be a serious obstacle towards effective HIV/AIDS prevention and control.展开更多
The activation of T cells to differentiate and to proliferate is an essential step in the immune response to antigen, especially in cell mediated acute allograft rejection. Besides the int...The activation of T cells to differentiate and to proliferate is an essential step in the immune response to antigen, especially in cell mediated acute allograft rejection. Besides the interaction of CD3/TCR complex with Ag/MHC complex presented on antigen presenting cells, a complete T cell activation and proliferation requires a second costimulatory signal. The interaction of CD28/CTLA 4 and B7 is a major costimulatory pathway for T Cell activation. Inhibition of this pathway results in development of antigen specific unresponsiveness and clonal anergy.In present study,the biologic function of anti CD28 monoclonal antibody and its Fab fragment were investigated in vitro and in vivo.The results indicate that mAbCD28 and its Fab fragments could promote the functional recovery of allografts and prolong the graft survival,but could not reverse the acute rejection or induce transplantation tolerance in the rat PTG allograft model. We also found that peripheral TNF α level and NK cell activity were suppressed in the presence of mAbCD28 and its Fab fragments for a relatively long time after PTG transplantation.展开更多
基金Supported by the Research Funit for the Doctoral Training Program from the Ministry of Education,No.2000002340 and Beijing Municipal Government Commission for Science & Technology,No.H020920020590
文摘AIM: To clarify whether -238G/A polymorphism of tumor necrosis factor-a (TNF-a) gene promoter region was associated with outcomes of hepatitis B virus (HBV) infection in Han population of northern China, and to analyze the geneenvironment interaction between -238G/A polymorphism and cigarette smoking or alcohol consumption. METHODS: A case-control study was conducted to analyze the association of TNF-a gene promoter polymorphism with HBV infection outcomes. A total of 207 patients with chronic hepatitis B (HB) and 148 cases of self-limited HBV infection from Ditan Hospital and Shunyi District Hospital in Beijing, respectively were recruited. History of smoking and alcohol drinking was inquired by a questionnaire. The -238G/A polymorphism of TNF-a gene promoter was genotyped by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP). RESULTS: The frequencies of GG and GA genotypes were 98.07% and 1.93% in chronic HB patients and 93.24% and 6.76% in self-limited HBV infection individuals, respectively (X^2=5.30, P=-0.02). The frequency of G allele was significantly higher in patients with chronic HB that in individuals with self-limited HBV infection (99.03% vs 96.62%, X^2=5.20, P=0.02). Only modestly increased risk of onset of chronic HB was found in smokers (OR=1.40, 95% CI： 0.87-2.28, P=0.14) and drinkers (OR=-1.26, 95%CI： 0.78-2.05, P=-0.32). There was a positive interaction between genotype GG and cigarette smoking with an interaction index (Ⅱ) of 2.95, or alcohol consumption with an Ⅱ of 1.64. CONCLUSION: The -238G/A polymorphism of TNF-a gene promoter region is independently associated with different outcomes of HBV infection.
基金supported by the grant of Shanghai Science and Technology Committee(No.03DZ19113)National Key Basic Research Program of China(No.2001CB510006)+1 种基金863 project(No.2001AA231011)a specific project against SARS from Chinese Academy of Sciences.
文摘The nueleocapsid (N) protein of severe acute respiratory syndrome-coronavirus (SARS-CoV) is a major virion structural protein. In this study, two epitopes (Nl and N2) of the N protein of SARS-CoV were predicted by bioinformatics analysis. After immunization with two peptides, the peptides-specific antibodies were isolated from the immunized rabbits. The further experiments demonstrated that N1 peptide-induced polyclonal antibodies had a high affinity to bind to E. coli expressed N protein of SAR,S-CoV. Furthermore, it was confirmed that Nl peptide-specific IgG antibodies were detectable in the sera of severe acute respiratory syndrome (SARS) patients. The results indicated that an epitope of the N protein has been identified and N protein specific Abs were produced by peptide immunization, which will be useful for the study of SARS-CoV.
基金This work was supported by the National Natural Science Foundation of China, No. 39928018, 30070038 and 30130070, National High-tech Research Development Program (863 Program), No. 2001AA215391, and EU Project QLRT, No. 200001441.
文摘Objective To expatiate dynamic changes in hamsters infected with scrapie strain 263K, to observe the presence and aggravation of various forms of PrP and PrPSc during incubation period, and to probe primarily the relationship between the onset of clinic manifestations and the presence of different PrPSc forms. Methods Hamster-adapted scrapie strain 263K was intracerebrally inoculated into hamsters. Different forms of PrP and PrPSc were monitored dynamically by Western blot and immuno-histochemical assays. The presence of scrapie-associated fibril (SAF) was assayed by electron microscopy analysis (EM) and immune-golden EM. Results PrPSc was initially detected in the brain tissues of the animals in 20 days post-inoculation by immunohistochemistry and 40 days with Western blot. Quantitative evaluations revealed that the amounts of PrP and PrPSc in brain tissues increased along with the incubation. Several high and low molecular masses of PrP were seen in the brains of the long-life span infected animals. Deglycosylation assays identified that the truncated PrP in the infected brains showed similar glycosylation patterns as the full-length PrP. The presence of short fragments was seemed to relate with the onset of clinical conditions. Conclusion These results indicate that infectious agents exist and accumulate in central nerve system prior to the onset of the illness. Various molecular patterns of PrPSc may indwell in brain tissues during the infection.
文摘AIM: To describe the mortality rate of pancreatic cancer and its distribution in China during the period of 1991-2000.METHODS: Based on the data of demography and death collected through China′s Disease Surveillance Point System (DSPS) over the period of 1991-2000, the distribution of death rate of pancreatic cancer was described in terms of age group, gender, calendar year, rural/urban residence and administrative district.RESULTS: A total of 1 619 death cases attributed to pancreatic cancer (975 men and 644 women) were reported by DSPS during 1991-2000. The reported, adjusted and agestandardized mortality rates increased from 1.46, 1.75, and 2.18 per 100 000 populations in 1991 to 2.38, 3.06, and 3.26per 100 000 populations in 2000. The majority (69.62 %) of the deaths of pancreatic cancer were seen in the age group of 60 years and older. The mortality rate was higher in men than in women, but the male to female death rate ratios decreased during the 10 years. Our data also showed that the death rate of pancreatic cancer in urban areas was about 2-4 fold higher than that in rural areas, and in Northeast and East China, the death rates were higher than those in the other 5 administrative districts.CONCLUSION: The death rate due to pancreatic cancer was rising during the period of 1991-2000 and the peak mortality of pancreatic cancer might arrive in China.
基金This study was supported by Beijing Municipal Natural Sciences Foundation (Grant No. 7001004) Research Fund for the Doctoral Training Program from the Ministry of Education (Grant No. 20020023009) China Medical Board in New York (Grant No. 96-657).
文摘Objective To investigate the association of specific functional gene ACE (I/D) variants of the renin-angiotensin system with essential hypertension (EH) and interaction between ACE (I/D) gene and risk factors for EH in a genetically homogenous Mongolia rural population of China. Methods Individuals (n=1099) were recruited from general population of Kezuohouqi Banner in Inner Mongolian Autonomous Region. Results The association was found between ACE genotype DD plus ID and EH, with an interaction between ACE genotype DD plus ID and cigarette smoking in an additive model. Cigarette smoking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 7.10 to 1.16. Interaction between ACE genotype DD plus ID and alcohol drinking on EH appeared an additive model. Alcohol drinking index and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 1.66 to 1.09. BMI and ACE gene showed a low exposure-gene (LEG) effect on EH, with interaction indices from 6.15 to 2.49. Interactions between ACE genotype and WHR on EH showed a multiplicative model. In a short, there was an interaction between ACE gene and cigarette smoking, alcohol drinking and BMI on EH, especially in a low dose-exposure effect Conclusion It is important for individuals who carry ACE D allele gene to prevent EH, and furthermore, to prevent and control coronary heart disease, in a view of population-based prevention.
基金This work was supported by Chinese National Natural Science Foundation Grants 39928018,30070038 and 30130070, National High-tech Development Project (863 Project) 2001AA215391EU Project QLRT 2000 01441.
文摘Objective To understand the infectious characteristics of a hamster-adapted scrapie strain 263K with five different routes of infection including intracerebral (i.e.), intraperitoneal (i.p.), intragastrical (i.g.), intracardiac and intramuscular (i.m.) approaches. Methods Hamsters were infected with crude- or fine-prepared brain extracts. The neuropathological changes, PrPSc deposits, and patterns of PK-resistant PrP were analyzed by HE stain, immunohistochemistry (IHC) assay and Western blot. Reactive gliosis and neuron loss were evaluated by glial fibrillary acidic protein (GFAP) and neuron specific enolase (NSE) specific IHC. Results The animals inoculated in i.m. and Lp. ways with crude PrPSc extracts showed clinical signs at the average incubation of 69.212.8 and 65.5±3.9 days. Inoculation in i.c. and intracardiac ways with fine PrPSc extracts (0.00035 g) caused similar, but relative long incubation of around 90 days. Only one out of eight hamsters challenged in i.g way with low dosage (0.01 g) became ill after a much longer incubation (185 d), while all animals (4/4) with high dosage (0.04 g) developed clinical signs 105 days postinfection. The most remarkable spongiform degeneration and PrPSc deposits were found in brain stem among the five challenge groups generally. The number of GFAP-positive astrocytes increased distinctly in brain stems in all infection groups, while the number of NSE-positive cells decreased significantly in cerebrum, except i.c. group. The patterns of PK-resistant PrP in brains were basically identical among the five infection routes. Conclusion Typical TSE could be induced in hamsters by inoculating strain 263K in the five infection ways. The incubation periods in bioassays depend on infective dosage, administrating pathway and preparation of PrPSc. The neuropathological changes and PrPSc deposits seem to be related with regions and inoculating pathways.
基金This work was supported by a grant from the National Natural Science Foundation of China (grant no. 39840017).
文摘Objective To evaluate the genotoxic and nongenotoxic effects of short-term exposure to glycidyl mathacrylate (GMA) on human lung fibroblast cells (2BS cells) in vitro. Methods DNA strand breakage was determined by single cell gel electrophoresis, and DNA ladder formation assay and flow cytometric analysis were carried out to detect apoptic responses of cells to GMA exposure. The HPRT gene mutation assay was used to evaluate the mutagenicity, and the effect of GMA on gap junctional intercellular communication (GJIC) in the exposed cells was examined with the scrape loading/dye transfer technique. The ability of GMA to transform 2BS cells was also tested by an in vitro cell transformation assay. Results Exposure to GMA resulted in a dose-dependent increase in DNA strand breaks but not apoptic responses. GMA was also shown to significantly induce HPRT gene mutations and morphological transformation in 2BS cells in vitro. In contrast, GMA produced a concentration-dependent inhibition of GJIC. Conclusions GMA elicits both genotoxic and nongenotoxic effects on 2BS cells in vitro. The induction of DNA damage and gene mutations and inhibition of GJIC by GMA may casually contribute to GMA-induced cell transformation.
基金Supported by the National Natural Sciences Foundation of China(General Program: 3037030 30270657 and Key Program: 30230150) Early Phase Study Supported by the Key Basic Research Project (2002-CCA04100) the National High Technology Research and Devel
文摘Objective To deduce all potential ligands undiscovered experimentally by searching all the proteins containing same C-termini, which can bind a certain PDZ domain. Methods We developed a JAVA program for searching short exact sequence matches at C-terminus. According to the known C-termini, which PDZ domains recognized experimentally, Swissprot database has been searched by this program for all potential ligands. Results Some PDZ domains may have more potential ligand proteins, which are undiscovered yet experimentally. These bioinformatic results also provide clues for studying functions of hypothetical proteins and PDZ domains’ protein interactions in many different organisms. Conclusion The results may provide useful clues for discovering potential functions of hypothetical proteins and new functions of known proteins.
文摘The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart disease (CHD) and 100 healthy individuals selected from Chinese Han nationality.Twelve segregating alleles (3’β29 -51) were observed in the pooled total of 203 subjects. The most common allele was 3’β 37. followed by 3’β39 with frequencies of 0. 362 and 0. 296, respectively. This model of allele distribution was coincident with the results form different ethnic groups, but the relative frequencies of alleles were different. In comparison with the allele frequencies between the patients and controls,alleles bigger than 3’β39 (3’VNTR-B) were significantly more common among the patients than among the controls (P<0. 001). Moreover. in the CHD group patients with plasma levels of TC≥3.88 mmol/L,LDL-C≥2. 59 mmol/L and HDL-C<l. 16mmol/L had significantly higher frequencies of 3’ VNTR-B allele (P<0. 01). Therefore,it is suggested that 3’ VNTR-B allele might be involved in the development of coronary atherosclerosis, presumably through their influences on lipid metabolism.This study supported by “8. 5” grant from Ministry of PublicHealth.
基金supported by grants from the Special Fund for Major State Basic Research Project(No.G1999055901)National Natural Sciences Foundation of China(No.30240019)+1 种基金National High Technology Research and Technology of China(No.2001AA221131)State Ministry of Science and Technology Program(No.2002BA711A011.
文摘Variable Charge X/Y (VCX/Y) is a human testis-specific gene family that localized on X and Y chromosomes. In this study, VCY protein was expressed in E. coli in the form of glutathione-S-transferase (GST) fusion protein. With the purified fusion protein as antigen, the anti-GST-VCY antibody was generated and the localization of VCY protein in human testis was determined by immunohistochemistry. In the testis seminiferous epithelium. VCY proteins were highly expressed in nuclei of germ cells. Using propidium iodide staining and green fluorescent protein (GFP) tag technologies, VCY and VCX-8r proteins were mainly localized in the uucleoli of COST cells. In addition, the colocalization for VCY and VCX-8r in COS7 cells was also observed. With VCY cDNA as bait, a cDNA fragment of acidic ribosomal protein PO was obtained using yeast two-hybrid system. All the information above indicates that VCX/Y protein family might be involved in the regulation of ribosome assembly (hiring spermatogenesis.
文摘The method of laser capture microdissection (LCM) combined with suppressive subtractive hybridization (SSH) was developed to isolate specific germ cells from human testis sections and to identify the genes expressed during differentiation and development. In the present study, over 10,000 primary spermatocytes and round spermatid cells were successfully isolated by LCM. Using the cDNAs from primary spermatocytes and round spermatids, SSH cDNAs library of primary spermatocyte-specific was constructed. The average insert size of the cDNA isolated from 75 randomly picked white clones was 500 bp, ranging from 250 bp to 1.7 kb. Using the dot-blot method, a total of 421 clones were examined, resulting in the identification of 390 positive clones emitting strong signals. Partial sequence of cDNAs prepared from each clone was determined with an overall success rate of 84.4%. Genes encoding cytochrome c oxidase II and the rescue factor-humanin were most frequently expressed in primary spermatocytes, suggesting their roles involved in meiosis.
基金This work was supported by grants from the China Medical Board of New York, Inc. (Grant No. CMB 96-657) the National Natural Science Foundation of China (Grant No. 39760067 and 39870687).
文摘Objective To evaluate the potential implications of the genetic variability of angiotensin converting enzyme, angiotensinogen and angiotensin II type 1 receptor gene for essential hypertension in Tibetan. Methods A case-control study was conducted in 173 hypertensive individuals and 193 individuals with normal blood pressure. Multiple logistic regression analyses were used to estimate the risks of developing hypertension for different genotypes, and haplotype analyses of the angiotensinogen gene were used to determine the association between two-locus angiotensinogen gene polymorphisms and hypertension. Results As to the risk to high blood pressure and high systolic pressure, women with MM genotype were 7.7 (95% CI: 1.3-20.5) and 8.7 (95% CI: 1.8-20.1) times higher than those with TT genotype after adjustment for age and body mass index. Haplotype frequencies for M235T and G-6A were significantly different between hypertensive individuals and controls, which indicated an association of angiotensinogen gene haplotypes with hypertension, and a significant association of 235T/-6A haplotype with hypotensive effect. Conclusion Our results suggest that angiotensinogen gene 235MM is a predictor for hypertension development in Tibetan women but not in men, and may exert its hypertensive effect on linkage disequilibrum with a possible function locus of G-6A.
基金the National Natural Science Foundation (Grant No. 30170441,39896200)863 High Tech Project (Grant No. 2001AA221161)+2 种基金 National 973 Project (Grant No.G1998051016) Beijing Natural Science Fund (Grant No. 7002026)the National High EducationSci
文摘Objective To investigate the distribution of single nucleotide polymorphisms (SNPs)in CAPN10 gene in Chinese population and their relation with type 2 diabetes mellitus inHan people of Northern China. Methods CAPN10 gene was sequenced to detect SNPs indifferent nationalities of China. Five SNPs were chosen to perform case-control study andhaplotype analysis in 156 normal Han people of Northern China and 173 type 2 diabetes. OneSNP was also analyzed with transmission-disequilibrium test (TDT) and sib transmission-disequilibrium test (STDT) in 68 type 2 diabetes pedigrees (377 people). Results A totalof 40 SNPs were identified in length of 8 936bp, with an average of 1 in every 223bp. TheSNPs in CAPN10 gene did not distribute evenly and the SNPs in Chinese were different fromthose reported in Mexican American. There was no significantly statistical difference in theallele frequency of the 5 SNPs between case and control, and the haplotype frequencies inthe two groups were not significantly different. No positive results was found in TDT andSTDT analysis. Conclusions The SNP distribution of CAPN10 gene differs in differentnationalities. The studied SNPs in CAPN10 gene may not be the major susceptibility onesof type 2 diabetes mellitus in Han people of Northern China.
文摘Objective To investigate the molecular mechanism of atherosclerosis that related to age. Methods Immunohistochemistry staining and Western blot were adopted to determine the nuclear translocation of nuclear factor-kappa B (NF-κB) and expression of platelet-derived growth factor B (PDGF-B) in smooth muscle cells (SMCs) co-cultured with low density lipoprotein (LDL), oxidized LDL (ox-LDL), and ox-LDL+high density lipoprotein (HDL) originated from rats of 2 and 10 months old respectively. Fat stain was used to identify the lipid intake in SMCs. Results The optimal stimulation time of ox-LDL to SMCs was 12 hours. NF-κB intensity increased in most nuclei of SMCs that originated from rats of either 2 or 10 months old co-cultured with ox-LDL. The intensity of NF-κB and the amount of intracellular lipid taken in SMCs were more obvious in cells from 10-month-old rats than from the younger ones. Change of PDGF-B expression in SMCs was not remarkable in each group of rats. Conclusions The 10-month-old rats are more susceptive to ox-LDL than 2-month-old rats in activating nuclear transloca- tion of NF-κB. Maybe this is one of the important reasons contributing to the difference between the older and younger rats on the initiation and development of atherosclerosis lesion. Expression of PDGF-B is not associated with the activity of nuclear translocation of NF-κB.
基金the National Natural Science Foundation of China.
文摘To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. Methods The assessment was made with various anticancer drugs (adriamycin, mitomycin, cisplatinum and vincristine) that showed different cytotoxicities in transfectant HeLa cells with pSV-GT containing rat GST-pi cDNA (HeLa/pSV-GT) or control pSV-neo (HeLa/pSV-neo). Expression levels of GST-pi mRNA in HeLa/pSV-GT and HeLa/pSV-neo were measured by in situ hybridization using Digoxin-labelled cDNA probe. Results HeLa/pSV-GT expressed significantly high degree of GST-pi mRNA, whereas both HeLa/pSV-neo and HeLa cells had very low expression. Cytotoxicities of HeLa/pSV-GT and HeLa/pSV-neo with 4 anticancer drugs were measured by MTT assay. Drug concentrations for yielding 50% inhibition (IC50) in HeLa/pSV-GT by adriamycin, mitomycin and cisplatinum were 70.13 靏/mL, 10.95 靏/mL and 16.52 靏/mL, respectively. In contrast, IC50 in HeLa/pSV-neo was 10.34 靏/mL, 7.48 靏/mL and 13.70 靏/mL, respectively. The cytotoxicities of vincristine on both HeLa/pSV-GT and HeLa/pSV-neo were not significantly different. Conclusions Our findings suggest that HeLa/pSV-GT containing rat GST-pi cDNA is resistant to some anticancer drugs due to overexpression of GST-pi. Also, HeLa/pSV-GT cell line could serve as a useful cytogenetic model for further research.
基金the National Natural Science Foundation of China, No.39896200,No30170441the National High Technology Research and Development Program,No.2001AA221161,No.2002BA711A05,No.2002BA71 IA10-02+1 种基金The National Program for Key Basic Research Projects,No.G1998051016the Natural Science Foundation of Beijing,No.7002026
文摘AIM: To identify the susceptible gene (s) for type 2 diabetes in the prevousely mapped region, 1p36.33-p36.23, in Han population of North China using single nucleotide polymorphisms (SNPs) and to analyze the haplotypes of the gene (s) related to type 2 diabetes.METHODS: Twenty three SNPs located in 10 candidate genes in the mapped region were chosen from public SNP domains with bioinformatic methods, and the single base extension (SBE) method was used to genotype the loci for 192 sporadic type 2 diabetes patients and 172 normal individuals, all with Hah ethical origin, to perform this casecontrol study. The haplotypes with significant difference in the gene (s) were further analyzed.RFSULTS: Among the 23 SNPs, 8 were found to be common in Chinese Han population. Allele frequency of one SNP,rs436045 in the protein kinase C/ζgene (PRKCZ) was statistically different between the case and control groups (P＜0.05). Furthermore, haplotypes at five SNP sites of PRKCZ gene were identified.CONCLUSION: PRKCZgene may be associated with type 2 diabetes in Hah population in North China. The haplotypes at five SNP sites in this gene may be responsible for this association.
基金This work was supported by a grant from the National Natural Science Foundation of China (grant No. 39840017).
文摘Objective To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase chain reaction (DD-PCR) technique was used. cDNAs were synthesized by reverse transcription and amplified by PCR using 30 primer combinations. After being screened by dot blot analysis, differentially expressed cDNAs were cloned, sequenced and confirmed by Northern blot analysis. Results Eighteen differentially expressed cDNAs were cloned and sequenced, of which 17 were highly homologous to known genes (homology = 89%-100%) and one was an unknown gene. Northern blot analysis confirmed that eight genes encoding human zinc finger protein 217 (ZNF217), mixed-lineage kinase 3 (MLK-3), ribosomal protein (RP) L15, RPL41, RPS16, TBX3, stanniocalcin 2 (STC2) and mouse ubiquitin conjugating enzyme (UBC), respectively, were up-regulated, and three genes including human transforming growth factor b inducible gene (Betaig-h3), a-1,2-mannosidase 1A2 (MAN 1A2) gene and an unknown gene were down-regulated in the GMA-transformed cells. Conclusion Analysis of the potential function of these genes suggest that they may be possibly linked to a variety of cellular processes such as transcription, signal transduction, protein synthesis and growth, and that their differential expression could contribute to the GMA-induced neoplastic transformation.
基金The project was funded by NGO section related to Health Ⅸ Project, the World Bank Loan.
文摘Objective In order to explore the features of discrimination against people with HIV/AIDS in rural areas, a community-based intervention was carried out in two pilot communities of X County of Shanxi Province from September 2002 to October 2003. Methods Data were collected using qualitative methods (in-depth interview and focus group discussion) and anonymously structured questionnaires. Results (1) Severe discrimination against people infected with HIV/AIDS was revealed in the target communities. However, the response to HIV/AIDS was different in each community. (2) People were reluctant to disclose their HIV status or get tested for HIV, which endangered their sexual partners to contract HIV through unprotected sexual intercourses. (3) Attitudes towards people infected with HIV/AIDS varied. (4) Public education promoted a better understanding of HIV/AIDS which in turn improved community attitudes and behaviors towards people with HIV/AIDS. Conclusion HIV/AIDS-related discrimination undermines both individuals and communities responses to HIV/AIDS and may be a serious obstacle towards effective HIV/AIDS prevention and control.
文摘The activation of T cells to differentiate and to proliferate is an essential step in the immune response to antigen, especially in cell mediated acute allograft rejection. Besides the interaction of CD3/TCR complex with Ag/MHC complex presented on antigen presenting cells, a complete T cell activation and proliferation requires a second costimulatory signal. The interaction of CD28/CTLA 4 and B7 is a major costimulatory pathway for T Cell activation. Inhibition of this pathway results in development of antigen specific unresponsiveness and clonal anergy.In present study,the biologic function of anti CD28 monoclonal antibody and its Fab fragment were investigated in vitro and in vivo.The results indicate that mAbCD28 and its Fab fragments could promote the functional recovery of allografts and prolong the graft survival,but could not reverse the acute rejection or induce transplantation tolerance in the rat PTG allograft model. We also found that peripheral TNF α level and NK cell activity were suppressed in the presence of mAbCD28 and its Fab fragments for a relatively long time after PTG transplantation.
