Biomedical subjects

S Yu

Publications and source records attributed to S Yu.

At least 199 records · Page 11Linked to original sources

PubMed1999

Expansion and immunological study of human tumor infiltrating gamma/delta T lymphocytes in vitro.

Goffa/delta T cells have stimulated a lot of interest because of their unique features in antigen recognition and cytotoxicities to many autologous and/or allogeneic tumor cells. We have developed a novel method to selectively expand larger amounts of human tumor-infiltrating gamma/delta T lymphocytes (gamma/delta TILs) ex vivo by immobilized pan- anti-TCRgamma/delta monoclonal antibody in the presence of exogenous IL-2. The expanded gamma/delta TILs mainly expressed CD45RO and HLA-DR molecules and did not express CD4. CD8+ gamma/delta TILs accounted for 19% of gamma/delta TILs. The expression of CD25 molecule on expanded gamma/delta T cells was inducible and downregulated following a time course. The Vdelta1 and Vdelta2 subsets amount to 37 and 58%, respectively. The expanded gamma/delta TILs show an IL-2-dependent proliferation, MHC class I-unrestricted and TCRgamma/delta-related cytotoxicities to two MHC class I+ and two MHC class I+ allogeneic tumor cell lines in vitro.

Adenocarcinoma↗

PubMed1999

Identification of two novel deletion mutations within the Gs alpha gene (GNAS1) in Albright hereditary osteodystrophy.

Albright hereditary osteodystrophy (AHO) is a genetic disorder characterized by short stature, skeletal defects, and obesity. Within AHO kindreds, some affected family members have only the somatic features of AHO [pseudopseudohypoparathyroidism (PPHP)], whereas others have these features in association with resistance to multiple hormones that stimulate adenylyl cyclase within their target tissues [pseudohypoparathyroidism type Ia (PHP Ia)]. Affected members of most AHO kindreds (both those with PPHP and those with PHP Ia) have a partial deficiency of Gs alpha, the alpha-subunit of the G protein that couples receptors to adenylyl cyclase stimulation, and in a number of cases heterozygous loss of function mutations within the Gs alpha gene (GNAS1) have been identified. Using PCR with the attachment of a high melting domain (GC-clamp) and temperature gradient gel electrophoresis, two novel heterozygous frameshift mutations within GNAS1 were found in two AHO kindreds. In one kindred all affected members (both PHP Ia and PPHP) had a heterozygous 2-bp deletion in exon 8, whereas in the second kindred a heterozygous 2-bp deletion in exon 4 was identified in all affected members examined. In both cases the frameshift encoded a premature termination codon several codons downstream of the deletion. In the latter kindred affected members were previously shown to have decreased levels of GNAS1 messenger ribonucleic acid expression. These results further underscore the genetic heterogeneity of AHO and provides further evidence that PHP Ia and PPHP are two clinical presentations of a common genetic defect. Serial measurements of thyroid function in members of kindred 1 indicate that TSH resistance progresses with age and becomes more evident after the first year of life.

Amino Acid Sequence↗

PubMed1999

Antibodies to a microbial peptide sharing sequence homology with betaA3-crystallin damage lens epithelial cells in vitro and in vivo.

Circulating auto-antibodies (Abs) against lens antigens (Ags) are highly prevalent in patients with cataract, but their origin and pathogenic significance are unknown. We hypothesized that Abs raised after exposure to infectious microbes could cross-react with lens Ags. To test this hypothesis, we generated a monoclonal Ab to human betaA3-crystallin. Epitope analysis indicated that the ETQAE sequence in the N-terminus region of betaA3-crystallin was critical for mounting a humoral response. Similar sequences were found in three microbial Ags. Mice injected with a microbial oligopeptide containing ETQAE emulsified with complete Freund's adjuvant (CFA) raised Abs which cross-reacted with betaA3-crystallin and developed lens epithelial cell (LEC) damage in vitro. We also genetically engineered an betaA3-crystallin-expressing E. coli. Mice immunized with the recombinant E. coli developed LEC damage. These results support the hypothesis that exposure to microbes having Ags homologous to self Ags can trigger a humoral immune response that leads to LEC damage in mice.

Amino Acid Sequence↗

PubMed1999

Role of protein kinase CK2 in phosphorylation nucleosomal proteins in relation to transcriptional activity.

Protein kinase CK2 undergoes rapid translocation to nuclear matrix and nucleosomes on androgenic stimulation of growth in prostatic epithelial cells. Further, CK2 appears to be regulated differentially in the transcriptionally active and inactive nucleosomes. We have investigated the role of CK2 in phosphorylation of nucleosome-associated proteins in the transcriptionally active and inactive nucleosomes that were isolated from ventral prostate subjected to different androgenic status in vivo. Proteins associated with these nucleosomes were phosphorylated via the intrinsic protein kinase activity, using [gamma-32P]ATP in the absence and presence of GTP. Several proteins appear to be potential substrates for CK2 associated with the nucleosomes. Among them are proteins that are differentially associated with the transcriptionally active and inactive nucleosomes. Phosphorylation of several of these proteins is modulated depending not only on their sites of association (i.e., active vs. inactive nucleosomes) but also on the state of transcriptional activity. Differential phosphorylation of specific proteins by CK2 associated with the active and inactive nucleosomes may be pertinent to the process of transcription regulation.

Animals↗

PubMed1999

Studies of molecular pharmacophore/receptor models for GABAA/BzR subtypes: binding affinities of symmetrically substituted pyrazolo[4,3-c]quinolin-3-ones at recombinant alpha x beta 3 gamma 2 subtypes and quantitative structure-activity relationship studies via a comparative molecular field analysis.

A series of symmetrically substituted pyrazoloquinolinones was synthesized to probe the BzR binding site of different GABAA/Bz receptor subtypes. The affinities of the ligands for different BzR subtypes have been determined by radioligand binding assays on 5 distinct recombinant GABAA receptor isoforms [alpha x beta 3 gamma 2 (x = 1,2,3,5, or 6)]. Most of the ligands synthesized exhibited potent biological activity in vitro. Among them, 3 ligands exhibited enhanced affinity for the alpha 2 beta 3 gamma 2 subtype in comparison to the other subtypes, six ligands demonstrated higher affinity for the alpha 3 beta 3 gamma 2 subtype, while 2 ligands showed some enhanced affinity for the alpha 5 beta 3 gamma 2 subtype. The remainder of the ligands exhibited relatively higher affinities at the alpha 1 containing subtype. To map out the steric and electronic differences between the benzodiazepine binding subtypes, a QSAR analysis by the method of Comparative Molecular Field Analysis (CoMFA) of each receptor subtypes was carried out.

Binding Sites↗

PubMed1999

A 40-kDa NF1-like protein, not YY1, binds to the rat p53 promoter for transactivation in various rat organs.

Two recognition motifs of a 40-kDa NF1-like protein were previously identified in the rat p53 promoter. One is located between -296 and -312 (NF1-like element 1) and the other between -195 and -219 (NF1-like element 2). The latter one was also identified as a NF1/YY1 recognition motif in the human p53 promoter. NF1 or YY1 binds to the motif and regulates the expression of the human p53 gene in a tissue-specific manner. In this study, we investigated the binding protein for NF1-like element 2 in various rat tissues. Unlike the human p53 transcription, an NF1-like protein, not YY1, bound to the motif in every tested tissue: thymus, kidney, and spleen. In vitro transcription assay also confirmed that the NF1-like protein regulated the p53 transcription in rat spleen, although the human p53 transcription was regulated by YY1 in that organ. The molecular mass of the binding protein was determined to be 40 kDa, which was the same as that of the NF1-like protein identified in liver. Therefore, the 40-kDa NF1-like protein may be a universal transcription regulator for the rat p53 gene.

Animals↗

PubMed1999

Cornu Ammonis of the dog: a rudimentary CA2 field is only present in a small part of the dorsal division, and is absent in the ventral division of the cornu Ammonis.

The relationship between mossy fiber projections and cytoarchitecture was studied in the cornu Ammonis (CA) of three mongrel dogs and two Japanese white rabbits. Precise comparisons were accomplished by examining adjoining sections that were stained by two methods: 1) the Timm-Danscher method which stains for zinc, which is contained in high concentrations in the mossy fiber terminals, and 2) thionin staining of the Nissl substance, so that the mossy fiber projections and cytoarchitecture could be closely compared in each subdivision of the CA. There was a cytoarchitectonically transitional zone (TZ) between CA3 and CA1 in both dogs and rabbits. The TZ was composed of an intermingling of CA3-like large pyramidal cells and CA1-like small pyramidal cells. Across the dorso-ventral length of the rabbit CA, the mossy fiber projections emitted from the dentate granular cell layer extended as far as the distal border of CA3 toward the TZ but did not enter the TZ or CA1. The TZ of the rabbit was equivalent to CA2 of Lorente de Nó (1934), that was characterized by CA3-like large pyramidal cells which did not receive mossy fiber inputs. In the dorsal CA of the dog, the mossy fiber projections extended across the CA3/TZ border, as far as the most distal part of the TZ in one dog but only for a short distance in the other two dogs. That part of the TZ which did not receive mossy fiber projections corresponded with CA2. There were no mossy fiber projections to CA1. In the ventral CA of the dog, however, mossy fiber projections were more extensive than in the dorsal CA, extending across CA3/TZ as well as TZ/CA1 borders to enter the proximal part of CA1. These observations indicate that there is a distinct CA2 in the rabbit CA, and that a rudimentary CA2 is present only in a small part of the dorsal CA of the dog, whereas it is absent in the ventral CA.

Animals↗

PubMed1999

In vitro and in vivo studies of the effect of a Chinese herb medicine on osteoclastic bone resorption.

OBJECTIVE: To study the effect of a Chinese herb on osteoclastic bone resorption and osteoporosis. MATERIALS AND METHODS: Osteoclasts were isolated and cultured for in vitro study of the effect of the Chinese herb Guizhou epimedium (Epimedium Leptorrhizum Stearn). The in vivo effect of this Chinese herb was also investigated in rats in whom osteoporosis was induced by ovariectomy; these results were then compared with the effects of estradiol in the same group of rats. RESULTS: The in vitro study showed that the epimedium inhibited the osteoclastic resorption of bone. The in vivo investigation demonstrated that both the epimedium and estradiol were able to increase mineral content and promote bone formation. CONCLUSION: The Chinese herb Guizhou epimedium is of potential use in the treatment of osteoporosis.

Animals↗

PubMed1999

[Cloning of mouse polycystic kidney disease 1 gene].

OBJECTIVE: To obtain mouse Polycystic kidney disease 1(PKD1) gene by plagues in situ hybridization from a genomic library. METHODS: With the use of partial mouse PKD1 genomic DNA fragments amplified by PCR as probes, a genomic library of 129SvTer mouse in bacteriophage vector was screened by plagues in situ hybridization. The inserts of genomic DNA fragments were analyzed by Southern blot, subclone and verified by sequencing. RESULTS: A positive phage clone was obtained after four-round screening. The sequence of the genomic DNA fragments inserted in the positive clone was in accordance with that of the Genebank. CONCLUSION: The authors found that the length and structure of mouse PKD1 genomic DNA fragments obtained from a genomic library were available to construct a replacement targeting vector.

Animals↗

PubMed1999

[The use of risk factors scoring method in screening for undiagnosed diabetes in general population].

OBJECTIVE: Based on an epidemiological survey of NIDDM in the general population, two sub-population groups were selected to develop a screening method on risk factors to identify people at increased risk for undiagnosed diabetes. METHODS: Logistic regression analysis on the original data of population A was carried out to screen the main risk factors of diabetes. The score of the variable was determined based on the OR value and the aggregate score was used to predict the risk of undiagnosed diabetes. Both validity and effectiveness of the method were evaluated in population B. RESULTS: Results showed that the risk of having diabetes in the population increased along with aggregate scores of the method. Trend chi 2 test showed statistical significance (P < 0.01). When the threshold value was set up at 7, both sensitivity and specificity for identifying undiagnosed diabetes were 74.3% and 63.2%, respectively making the positive predictive value 4.2% and negative predictive value 99.2%. CONCLUSION: The benefits of this screen method seemed to be simple, economical and helpful to obtain a satisfactory response rate. The method could be used for health education and to identify people (community) at high risk for potential diabetes. It was predicted that this screening method could serve as an effective and useful tool for mass screening of NIDDM.

Adult↗

PubMed1999

[Growth behavior of cells of ameloblastoma and odontogenic keratocyst].

OBJECTIVE: To compare the growth behavior of epithelium and fibroblast from ameloblastoma and keratocyst and to discuss the recurrence reason for the keratocyst. METHODS: Epithelial cells and fibroblast from ameloblastoma, keratocyst, dentigerous cyst, radicular cyst and oral mucosa were cultured and observed by phase-contrast microscope. RESULTS: The epithelial cells of ameloblastoma grew faster, with an irregular area around the cell mass and some small satellite-shaped cell mass. The epithelial cells of all the cysts and mucosa grew slower with the cell masses surrounded by fibroblasts which grew in whirl manner with a round and smooth periphery. CONCLUSION: The cells from the ameloblastoma grow faster and more active, and those from the keratocysts grow like the other cysts and the normal mucosa. It is speculated that the ameloblastoma grows in an aggressive manner and it is possible that the recurrence of the keratocyst isn't primarily resulted from its growth behavior as a tumor.

Ameloblastoma↗

PubMed1999

[Mechanical ventilation of advanced chronic obstructive pulmonary disease patients with recurrent severe respiratory failure].

OBJECTIVE: To summarize the results of patients of severe respiratory failure using multiple times mechanical ventilation (MV) via tracheal intubation (or via tracheotomy). METHODS: We retrospectively analysed clinical information and follow-up results of 15 acute exacerbation of COPD patients using MV more than 3 times. RESULTS: MV was used 77 times in 15 patients. The highest number of MV was 20.86% were weaned successfully. The mean duration of MV via intubation was 13 days and via tracheotomy was 37 days, mean 649 days via the latest brocheotomy after using MV multiple times. The survival duration after the first MV varied from 196 to 4 420 days in 15 patients, mean 1 093 days, medium survival duration of the patients was 1 673 days, survival rates after 1, 2, 3 and 5 years were 73%, 64%, 33% and 25% respectively. The causes of death were failure of multiple organs or disfunction of other vital organs. CONCLUSIONS: Repeated application of MV may prolong the survival rates of COPD with severe respiratory failure. It's important to take strictly the indication of MV, correctly to select the methods of artificial airway, combining invasive and noninvasive ventilation, properly to apply the strategies of MV.

Aged↗

PubMed1999

[A study on family aggregation of type 2 diabetes mellitus].

OBJECTIVE: To estimate the genetic susceptibility and its relative risk (RR) in the first degree relatives of type 2 diabetes mellitus (DM) through family aggregation analysis. METHODS: A population-based case-control study including 654 pedigrees (363 index cases and 291 controls) was carried out. RESULTS: The prevalence rate in the first degree relatives of DM probands was 3.94%, significantly higher than that in the controls (1.09%), with a relative risk of 3.62 (chi(2) = 36.5, P < 0.001). The RRs in different consanguineal relatives were all higher than 3.0. The younger was the probands at diagnosis for DM, the higher its prevalence rates and RRs among their relatives was and the more likelihood that more than one case of DM occurred in them. CONCLUSION: Significant family aggregation and higher genetic susceptibility were found in the first degree relatives of DM, on whom prevention and treatment for DM should be focused.

Adult↗

PubMed1999

[Relationship between glutathione S-transferase M1, T1 genotype and susceptibility to gastric cancer].

OBJECTIVE: The objective of this study was to examine the association between glutathione s-transferase M1, T1 genotype and the risk of gastric cancer. METHODS: A case-control study was carried out and polymerase chain reaction (PCR) technique was used to identify GST M1, GST T1 genotype in 95 cases of primary gastric cancer and 94 controls. RESULTS: The frequency of GST M1 null genotype was 63.16% and 45.74%, respectively in gastric cancer cases and control group, with statistically significant difference (chi(2) = 5.75, P = 0.0165). GST M1 null genotype correlated with the susceptibility to gastric cancer (OR = 2.03, 95% CI of OR = 1.09 - 3.80). The risk for gastric cancer in those with GST M1 null and GST T1 non-null genotype was significantly higher than that in those with GST M1 non-null and GST T1 null genotype, with an OR of 2.91 and 95% CI of ORs 1.09 - 7.89. The risk for gastric cancer in those smoking with GST M1 null genotype increased significantly (OR = 8.06, 95% CI of OR = 2.83 - 23.67). CONCLUSION: GST M1 null genotype was associated with the risk for gastric cancer.

Adult↗

PubMed1999

[Observations on expression of c-fos and c-myc genes and activity of PDGFBB autocrine loop in 67 human gliomas].

OBJECTIVE: To investigate the variance of expression of c-fos and c-myc genes and the activity of platelet-derived growth factor (PDGF) BB autocrine loop in human gliomas as well as their relationship. METHODS: In situ hybridization and immunohistochemistry were used to study 67 human glioma specimens of different grades. RESULTS: The incidences, of positive expression for c-fos mRNA, c-fos protein, c-myc mRNA and c-myc protein were 100% (67/67), 100% (67/67), 85.1% (57/67) and 83.6% (56/67) respectively. There was significant positive correlation between the positive cell densities of c-fos mRNA (92.49 +/- 33.87) and c-fos protein (91.64 +/- 38.11), and of c-myc mRNA (72.70 +/- 40.56) and c-myc protein (71.49 +/- 41.11, r = 0.917 - 0.988, P < 0.001). All of them also increased correspondingly with the malignant degree of the tumors and level of PDGFB mRNA expression in the tumor cells (P < 0.05 - 0.01). Not only were the positive cell densities of PDGF alpha receptor (58.46 +/- 28.77), PDGF beta receptor (63.03 +/- 31.63) and phosphotyrosine protein (68.25 +/- 29.30) correlated positively with one another (r = 0.827 - 0.896, P < 0.001), but they also all correlated positively with the positive cell densities of PDGFB mRNA, c-fos mRNA, c-fos protein, c-myc mRNA and c-myc protein respectively (r = 0.615 - 0.888, P < 0.001). CONCLUSIONS: The abnormally increased activity of the PDGFBB autocrine loop possibly upregulated the overexpression of c-fos and c-myc genes in glioma cells and suggested that c-fos and c-myc proteins probably played an important role as downstream response factors in the signaling pathway in which PDGFBB could induce gliocyte transformation and glioma development.

Adolescent↗

PubMed1999

[V-ATPase inhibitor baflomycine A1 inhibits bone resorption by osteoclast-like cells].

OBJECTIVE: In order to compare the role of osteoclast-like cells (OLCs) originating from giant cell tumor of bone and the osteoclasts (OCs) on bone resorption, as well as to study which kind of proton pump is associated with bone resorption by the OLCs and its role related. METHODS: Culture of OLCs together with the bone slices, the number of pits and the surface areas formed by OLCs was counted. The effects of F0F1-ATPase inhibitor, oligmycine V-ATPase inhibitor, baflomycine of OLCs on bone resorption were compared. RESULTS: Baflomycine are considered effective in inhibiting bone resorption but no definited effect obtained with oligmycine. CONCLUSIONS: OLCs bear the similar bone resorption mechanism as that of OCs. It's considered that OLCs and OCs are derived from the same origin.

Animals↗

PubMed1999

[Studies on chemical constituents of Thalictrum atriplex Finet et Gagnep].

OBJECTIVE: To study the chemical constituents in the aerial part of Thalictrum atriplex. METHOD: Chromatography and spectral analysis were used to isolate and elucidate the constituents. RESULT: Six compounds were isolated from the aerial part of Thalictrum atriplex, and elucidated as protocatechuic acid, caffeic acid, p-coumaric acid, kaempferol, beta-sitosterol and N-methylcorydaldine. CONCLUSION: They are all isolated from the plant for the first time.

Caffeic Acids↗

PubMed1999

[The effect of age on the regional blood flow of neck of femur in normal Chinese].

This study aimed to assess the effect of age on the regional blood flow of neck of femur in normal Chinese. 133Xe washout method was adopted. The result showed that the femur regional blood flow of normal Chinese decreased slowly with the increase of their age. The relation between age and femur blood flow might be expressed as F = -0.042Y + 9.01(F refers to blood flow, Y refers to age). The average femur regional blood flow of normal Chinese was 7.37 +/- 0.62 ml.(100 g.min)-1 for 21-40 years old. The authors suggest this result can be considered to stand for regional femur blood flow of young healthy adults.

Adolescent↗