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Biomedical subjects

Y Pan

Publications and source records attributed to Y Pan.

At least 73 records · Page 4Linked to original sources
PubMed2001

5q11, 8p11, and 10q22 are recurrent chromosomal breakpoints in prostate cancer cell lines.

Prostate cancer cell lines have been widely used as model systems characterizing pathogenetic, functional, and therapeutic aspects of prostate cancer development. However, their chromosomal compositions are poorly characterized. In this study, five prostate cancer cell lines-TSU-Pr1, JCA-1, NCI-H660, ALVA-31, and PPC-1-were investigated by G-banding, comparative genomic hybridization (CGH), and spectral karyotyping. The results were combined with our previous findings in the prostate cancer cell lines PC-3, DU145, and LNCaP. By comparative genomic hybridization (CGH), the most frequent losses were observed at 13q, 8p, 9p, and 4q, whereas gains were most commonly seen at 8q, 10q, and 18p. The composite karyotypes were characterized by multiple numerical and structural chromosomal aberrations. Recurrent breakpoints at 5q11, 8p11, and 10q22 were observed to participate in deletion and translocation events in five of the cell lines, suggesting the importance of tumor suppressor and/or oncogenes in these regions. ALVA-31 and PPC-1 shared nine identical derivative chromosomes, two of which have also been detected in PC-3. In addition, the identification of the same homozygous deletion at D10S541 and of an identical TP53 gene mutation in all three cell lines suggests a common origin of these cell lines.

Chromosome Breakage↗
PubMed2001

[The use of limit amplitude technique in clinical cardiac electrical signal recording].

Based on the electrophysiologic mechanism of cardiac electrical action and the theory of voltage effect, the limit amplitude technique was employed to obtain the best clinical record effects. The results showed that limiter could limit the oversize signals overlapping each other and make the tiny signals magnification without distortion, such as the His bundle deflection in His Bundel Electrogram. At the same time, all signals recorded at multichannel physiologic recorder were clear and did not interfere with each other. Furthermore, the limiter not only improved the recording quality but also protected the cardiac electronic equipment because overdue stimulation signal was limited at a given electronic level during the recording of transesophageal pacing.

Electrocardiography↗
PubMed2001

Deletions on chromosome 8p22 may predict disease progression as well as pathological staging in prostate cancer.

PURPOSE: A recent report demonstrated that the deletion of chromosome 8p22 could predict disease progression in stage III (capsular penetrating) prostate cancer. We studied if the status of chromosomal deletions of 8p22 could reflect pathological stage as well as patient prognosis, thereby serving as a diagnostic tool to optimize the treatment strategy in prostate cancer. EXPERIMENTAL DESIGN: A total of 97 patients (41 Japanese and 56 Swedish) were studied by the fluorescence in situ hybridization technique. Seventy-seven patients (23 pT2, 18 pT3, and 36 pN+ tumors) underwent surgery (radical prostatectomy or lymph node dissection). The specimens were prepared by touch biopsy. From another 20 cases, fine-needle aspiration biopsies were obtained. RESULTS: 8p22 deletions were detected in 47 (61%) and 11 (55%) specimens of 77 touch biopsies and 20 fine-needle aspiration biopsies, respectively. No significant difference was found in the frequency of 8p22 deletion between different preparations of specimens, as well as between different races (Japanese versus Swedish). The frequency of 8p22 deletion was statistically higher in patients with pT3 or more than in those with pT2 (P < 0.01). Disease progression was evaluated in 57 patients. The Cox proportional hazards model revealed 8p22 deletion to be the strongest parameter to predict disease progression (hazards ratio = 5.75; P = 0.0001). CONCLUSIONS: Studies on chromosomal deletions of 8p22 by fluorescence in situ hybridization technique may serve as a genetic marker to optimize the treatment strategy in patients with prostate cancer to the optimal treatment.

Aged↗
PubMed2001

[Assay of trace elements and heavy metals in different growth stages of Ganoderma lucidum].

The trace elements and heavy metals in the different growth stages of Ganoderma lucidum were analyzed by ICP-MS, AFS and AAS. The fermented mycelia, fruiting bodies and spore contained all kinds of detected trace elements and heavy metals, the contents of which were higher in spore. The content of Se was same in different growth stages. Ganoderma lucidum had the ability of bio-enrichment of Ge.

Fruit↗
PubMed2001

Cell adhesion molecule expression in cultured human iris endothelial cells.

PURPOSE: To develop a method to isolate human iris microvascular endothelial cells (HIECs) for exploring their constitutive and inflammatory agent-modulated expression of intercellular adhesion molecules (ICAM)-1 and -2, vascular cell adhesion molecule (VCAM)-1, and E-selectin. METHODS: Endothelial cells from collagenase-digested irises were isolated on the basis of their expression of platelet endothelial cell adhesion molecule (PECAM)-1, using antibody-coupled magnetic beads. Cells were characterized as endothelial based on morphologic criteria, their expression of PECAM-1 and von Willebrand factor, their uptake of acetylated low-density lipoprotein, and their ability to form capillary-like networks on a synthetic basement membrane. Constitutive and inflammatory agent-modulated expression of ICAM-1 and -2, VCAM-1, and E-selectin was evaluated by the reverse transcription-polymerase chain reaction, enzyme-linked immunocellular assays (ELICAs), Western blot analysis, and functional studies of leukocyte adhesion to HIEC monolayers. RESULTS: HIECs constitutively expressed mRNA and protein for ICAM-1 and -2, but only low to nondetectable levels of VCAM-1 or E-selectin. When stimulated with endotoxin- or tumor necrosis factor (TNF)-alpha, ICAM-1, VCAM-1, and E-selectin were potently and time- and dose-dependently upregulated at both the message and protein levels. By contrast, ICAM-2 message and protein were slowly downregulated by inflammatory agents over time, but nonetheless remained present and functional. Overall, cytokine- or endotoxin-activation of HIECs resulted in enhanced adhesiveness for leukocytes. CONCLUSIONS: ICAM-1, VCAM-1, and E-selectin have been previously implicated in mediating anterior ocular inflammation. This is a report of the selective isolation of HIECs, with a demonstration of differential expression and regulation of these adhesion molecules in them. In addition, this is the first demonstration of the regulated expression of ICAM-2 in any ocular microvascular cells.

Adolescent↗
PubMed2001

[Refraction shift after intraocular lens implantation in children].

OBJECTIVE: To evaluate the refraction shift after posterior chamber intraocular lens (PC-IOL) implantation in children. METHODS: A long term retrospective study involved 65 eyes of 65 patients aged from 5 to 12 years who underwent PC-IOL implantation between December 1988 and December 1994. The mean follow-up was 7.1 years (range 5 to 10 years). Refraction shift, keratometric readings and axial length were periodically measured. Sixty-five healthy eyes were in the control group. RESULTS: The mean preoperative axial length of the surgical group was (22.48 +/- 0.44) mm, and of the control group, (22.43 +/- 0.41) mm. There was no statistically significant difference in axial length after 10 years in both groups, (23.45 +/- 0.53) mm in surgical group and (23.41 +/- 0.50) mm in control group. All the eyes showed a myopic drift with 3.29 D in surgical group and 1.75 D in control group (F = 2.318, P < 0.05). CONCLUSION: The ocular growth of children is found to be unaffected by the PC-IOL implantation, the choice of IOL power should be retained in physiological hyperopia in pseudophakic children.

Cataract↗
PubMed2001

[Cloning and analyzing of the conserved protein gene in Streptococcus sanguinis ATCC10556].

OBJECTIVE: To clone and analyze the conserved protein gene in Streptococcus sanguinis(S.s) ATCC10556. METHODS: Southern blotting hybridization, molecular cloning techniques and dot blotting hybridization were employed to obtain the target clone which harbored the specific DNA fragment. The nucleotide sequence of the target clone was determined. The gene and its product were analyzed by Genework software and bioinformatics techniques. RESULTS: The conserved protein gene in Streptococcus sanguinis ATCC10556 was cloned for the first time and named as Streptococcus sanguinis conserved protein gene (Sscp gene). The Genbank accession number for Sscp gene is AY032739. The conserved protein gene in S.s ATCC10556 (named sscp163) was a transmembrane protein and contained two AAA domains. CONCLUSION: sscp163 protein might take part in the cell division in Streptococcus sanguinis; its function is similar to that of FtsK in E.coli.

Amino Acid Sequence↗
PubMed2001

The analysis of peri-tumor necrosis following the subcutaneous implantation of autologous tumor cells transfected with an episome transcribing an antisense insulin-like growth factor 1 RNA in a glioblastoma multiforme subject.

A subject inflicted with glioblastoma multiforme who received partial tumor resection and radiotherapy was recruited for an ex vivo gene therapy protocol using irradiated autologous tumor cells that had been engineered to suppress the expression of insulin-like growth factor I as the tumor vaccine. After subcutaneous injection for 8 weeks, the subject developed peri-tumor necrosis with mass effect. The authors wondered whether this event could have resulted from the tumor vaccine. The tissue section bordering the necrotic tumor tissue to the viable normal tissue was examined for nature of any infiltrated cells and their activities. Lymphocytes, macrophages, and a small number of neutrophils diffused into the necrotic tumor tissue were found. The infiltrated lymphocytes consisted of both CD4+ and CD8+ T cells. The functional activity of these lymphocytes was demonstrated by the active production of interferon y and tumor necrosis factor alpha based on the respective immunofluorescent staining localized to these cells. This finding is compatible with the proposed mechanism underlying the tumor vaccination. However, the contribution of radiation treatment to this event cannot be clearly ruled out.

Brain Neoplasms↗
PubMed2001

Organochlorine pesticides and chlorinated hydrocarbon solvents in the blood of chemically sensitive patients [corrected]. A statistical comparison with therapeutic medication and natural hormones.

The blood levels of organochlorine pesticides and chlorinated hydrocarbon solvents were measured in 200 and 114 chemically sensitive patients respectively, and compared with blood concentrations of standard medication (non- chlorinated substances. Clonidine, Haloperidol) of comparable toxicity after therapeutically effective dosage, and with reference levels of highly potent chemicals in the blood such as hormones. It was shown that the average blood levels of the most toxic environmental pollutants are comparable with the therapeutic steady state average blood levels of medications which have similar toxicities in the animal model. In addition the toxicity levels of xenoestrogens are at least an order of magnitude higher than normal plasma estrogen or progesterone levels. These findings suggest the possibility of additive or synergistic effects of these chlorinated compounds and the aforementioned medications. Also, these findings suggest the possibility of hormone deregulation from exposure to the aforementioned toxic chlorinated compounds.

Adolescent↗
PubMed2001

[A study on transmission of pathogenic bacteria of rampant caries from mothers to children].

OBJECTIVE: In order to prevent rampant caries in children, the transmission from mothers to children of pathogenic bacteria of rampant caries will be investigated in this study. METHODS: By using fingerprint technique, the genetic diversities of Streptococcus mutans(S. mutans) were examined respectively in 10 children with rampant caries, 10 children without rampant caries S. mutans, 10 2-year-old caries-free children, and their mothers. The levels of S. mutans in saliva of mothers were also examined. For fingerprinting, chromosomal DNA of isolates obtained from plaques of these children and from saliva of their mothers were digested with restriction endonuclease HindIII and examined by electrophoresis on 0.7% agarose gel. DNA fingerprints were obtained and analyzed for genotypic similarities. RESULTS: The DNA fingerprint patterns showed that the proportion of children whose genotypes of S. mutans matched their mothers in the children with rampant caries was 70%, which is similar to that in the children without rampant caries and the caries-free children (60% respectively). The number of distinct genotypes of S. mutans harbored in children with rampant caries was, on average, greater than the number of genotypes present in children without rampant caries and caries-free children (1.7, 1.2 and 1.1 respectively, P < 0.05). Mothers of children with rampant caries had similar levels of S. mutans in saliva as those mothers of children without rampant caries and caries-free children. However, mothers of children with rampant caries had significantly higher DMFT scores and higher levels of Streptococcus sobrinus (S. sobrinus) in saliva than the mothers of caries-free children did. CONCLUSION: In all child groups, mothers were probably the main source of infection with S. mutans. Rampant caries in children is associated with DMFT scores and levels of S. sobrinus in saliva of mothers. In the initiation of rampant caries experienced by a child, the transmission of pathogenic bacteria from mothers to children may be the main source.

Adult↗
PubMed2001

[IL-1 beta mRNA and TNF-alpha mRNA expression in gingival tissues of patients with adult periodontitis].

OBJECTIVE: The aim of this study was to examine interleukin-1 beta (IL-1 beta) mRNA and tumor necrosis factor alpha (TNF-alpha) mRNA expression in gingival tissues of patients with adult periodontitis. METHODS: A total of 19 patients, including 10 patients with adult periodontitis and 9 healthy individuals as the control, were evaluated for were selected for evaluating IL-1 beta mRNA and TNF-alpha mRNA expression, using reverse transcription polymerase chain reaction (RT-PCR) technique. RESULTS: The relative amount of IL-1 beta mRNA expression of gingival samples from patients with adult periodontitis (0.819 +/- 0.045) (P < 0.01) was much higher than that from the normal control (0.306 +/- 0.087) (P < 0.01). The relative amount of TNF-alpha mRNA expression, gingival samples from AP patients (0.696 +/- 0.098) was also much higher than that from the normal control (0) (P < 0.01). CONCLUSION: As the inflammatory and bone absorption mediators, IL-1 beta and TNF-alpha might play important roles in the pathogenesis and development of adult periodontitis.

Adolescent↗
PubMed2001

[Expression changes of nerve growth factors (NGF) in pulps of injury teeth].

OBJECTIVE: The aim of this study is to investigate the expression and functions of nerve growth factors during teeth injury. METHODS: Twenty male Wistar rats were given mechanical irritation in upper first molar and their molecular and biological changes were examined in different periods. Four of them were killed immediately after the teeth were irritated, the other four were killed 3 days, 5 days, and 9 days respectively after the teeth were stimulated. The perfusion was performed through the left ventricle with 4% paraformaldehyde and 0.2% picric acid in 0.1% phosphate buffer. The maxilla was decalcified and embedded. Sections of 15 microns in thickness were cut with freezing macrodome in the sagittal planes. Then the sections were stained with immunohistochemical method to observe changes of NGF in the injured dental pulp, comparing with that in the normal dental pulp. In the end, we observed the NGF distribution in the pulp under optical microscope, and analyzed the expression level of NGF with the image pattern analysis instrument. The results were statistically analyzed. RESULTS: In the normal group, the NGF expression was not observed. In the experimental group of zero hour, the NGF expression could be observed, but was very low. In the experimental group of three days, the NGF expression increased greatly, and the positive sites mainly distributed in the odontoblastic and the sub-odontoblastic layer. They also distributed in dentinal tubules. But in the group of 5 days, the level of NGF decreased. In the group of 9 days, it was the same as that of the normal group. Using the image pattern analysis instruments and statistical analysis, the results clearly showed that the expression level were lower in the group of three days than that of the other groups, and the expression levels of the groups 0 and 5 days were lower than that of the normal control group, however, that of 9-day group was the same as the normal group. CONCLUSION: NGF may play a role in the reaction and nerve restoration after teeth injury and, the expression change in different stages.

Animals↗
PubMed2001

[The isolation and identification of pathogenic bacteria from rampant caries in children].

OBJECTIVE: In order to prevent rampant caries in children, the predominant pathogenic bacteria of rampant caries in children were defined. METHODS: The pathogenic bacteria of rampant caries were isolated and identified in 30 children with rampant caries, aged from 2 to 5 years old. Samples were collected from the caries of labial surfaces of maxillary anterior deciduous teeth, including caries lesions and caries-free smooth enamel surfaces. Plaque were obtained from the cervical third areas of the maxillary labial anterior deciduous tooth surfaces in children without rampant caries and caries-free children and served as controls respectively. The isolates were identified by colony morphology, biochemical tests and DNA base contents (mol percent G + C). RESULTS: The prevalence of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) in the plaque of caries lesions and the proportions of S. mutans and S. sobrinus in the plaque of 2 sampling sites of children with rampant caries were all significantly higher than those of children without rampant caries and caries-free children (P < 0.05). CONCLUSION: S. mutans and S. sobrinus are predominant pathogenic bacteria in rampant caries in children.

Child↗
PubMed2000

Identification of a tumor-derived p53 mutant with novel transactivating selectivity.

MDM2 is a p53-responsive molecule that when overexpressed, can alter growth control pathways via p53-dependent and independent mechanisms. We have identified a mutant p53 containing line that expresses high levels of transcripts that are regulated by the p53-responsive promoter of the MDM2 gene. Analysis of cloned product obtained from these tumor cells revealed that they harbor a mutant p53 protein (possessing an Arg to Gln substitution at codon 213) that is a potent transactivator of MDM2 expression. Consistent with this activity, the R213Q mutant was found to have the ability to interact with DNA sequences located within the MDM2 promoter. In contrast to previously described tumor-derived p53 mutants which retain MDM2 transactivation function and possess partial growth suppressive activity, the R213Q mutant is severely compromised in its ability to induce p53-regulated transcripts that encode for proteins involved in cell-cycle arrest and apoptosis. The R213Q mutant can also be expressed at high levels in stably transfected cells and cells that harbor this mutant possess elevated levels of MDM2 protein. The R213Q mutant was also found to be able to up-regulate MDM2 during a genotoxic stress response. R213Q is the first described tumor-derived p53 mutant that is deficient at up-regulating both cell cycle arrest and apoptotic factors, but is highly proficient at inducing the growth-promoting molecule MDM2.

Apoptosis↗
PubMed2000

Identification and gene organization of three novel members of the IL-1 family on human chromosome 2.

Members of the IL-1 family of cytokines are important in mediating inflammatory responses. The genes encoding IL-1alpha, IL-beta, and the IL-1 receptor antagonist (IL-1Ra) are clustered within 450 kb on human chromosome 2q. By searching the EST databases and sequencing this region of chromosome 2, we have identified three novel genes that show homology to the IL-1 family, which we have named IL-1-related protein 1, 2, and 3 (IL-1RP1, IL-1RP2, and IL-1RP3). All three genes contain a signature motif common to the IL-1 family and appear to be more closely related to IL-1Ra. Similar to the intracellular form of IL-1Ra, these genes lack conventional hydrophobic signal sequences. The expression of these genes appears to be highly restricted to various epithelial cell populations. Our results demonstrate the existence of additional IL-1 gene family members within the previously defined IL-1 cluster and point to this region of chromosome 2 as an evolutionary hotspot for IL-1 gene duplication. These genes may prove to have an important role in inflammatory responses.

Amino Acid Sequence↗
PubMed2000

Expression of insulin-like growth factor-I in rat glioma cells is associated with change in both immunogenicity and apoptosis.

Insulin-like growth factor I (IGF-I), has a role in cellular differentiation and is also expressed in neoplastic transformation of glioma cells. We recently demonstrated inhibition in expression of cellular IGF-I after transfection with vectors that incodes a segment of the human IGF-I RNA in antisense orientation. The transfected cells expressed increased levels of both MHC-I and B7 molecules. In this paper we show that IGF-I antisense transfected cells also become apoptotic. Moreover, the phenomenon of programmed cell death is related to the phenomenon that results in increased expression of MHC-I and B7 molecules. Co-transfection of rat glioma cells with the vector expressing IGF-I antisense RNA and with vectors encoding the expression of MHC-I and B7 antisense cDNA suppressed the expression of both of these molecules and was associated with a decrease in apoptosis.

Animals↗