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Biomedical subjects

Y Jin

Publications and source records attributed to Y Jin.

At least 253 records · Page 14Linked to original sources
PubMed1999

[The apoptosis and proliferation after photorefractive keratectomy].

OBJECTIVE: To search the correlation between the apoptosis and proliferation of keratocytes and investigate the influence of phototherapeutic keratectomy (PTK) and mechanical epithelial scrape (MES) on keratocyte apoptosis and proliferation. METHODS: Rabbit corneas received photorefractive keratectomy (PRK, -9.9 diopters, 6 mm diameter). Animals were evaluated subsequently up to 6 months after surgery by in vivo confocal microscopy. Corneas were prepared for H.E. staining, corneal cell apoptosis was evaluated by terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) to detect DNA fragmentation. RESULTS: Loss of keratocytes and keratocyte death were found anteriorly in the remaining stroma at 4h after PRK. Activated keratocytes observed by confocal microscopy repopulated within 1 month. A significant elevation of apoptosis was detected in keratocytes and epithelium at 4h, 3d, 1m after PRK. The level of keratocyte apoptosis was parallel to the loss of keratocytes at the early stage and was correlated with keratocyte proliferation in the later stage, PTK-PRK was associated with lower levels of central corneal apoptosis and activated keratocytes than MES-PRK. CONCLUSION: It is suggested that the loss of keratocytes and keratocyte apoptosis be correlated with keratocyte activation and proliferation, which may result in haze and regression after PRK, and PTK-PRK induce lower level of early keratocyte apoptosis and late keratocyte activation than MES-PRK.

Animals↗
PubMed1999

[Excimer laser photorefractive keratectomy for lower to moderate myopia: 5 year follow-up].

OBJECTIVE: To evaluate the long-term effectiveness and safety of photorefractive keratectomy (PRK) for patient with lower to moderate myopia. METHODS: 148 myopic eyes (-1.5 to -6.00 D) after PRK follow-up of more than 5 years were analyzed. RESULTS: Uncorrected visual acuity was >or= 1.0 in 136 eyes (91.9%), >or= 0.8 in 4 eyes (2.7%) and >or= 0.6 in 8 eyes (5.4%). The mean spherical equivalent change was from (-4.43 +/- 0.97) D to (-0.12 +/- 0.22) D, and the keratometric power (K value) was reduced from (43.81 +/- 1.10) D to (41.36 +/- 1.30) D in the 5 years of follow-up (P < 0.01). CONCLUSION: The long-term effectiveness of PRK for myopia (-1.5 to -6.00 D) is satisfactory.

Female↗
PubMed1999

[Molecular cloning of hTRT catalytic domain and its expression in tumors].

OBJECTIVE: To study the expression of hTRT gene in tumors and its significance in cancer diagnosis. METHODS: The expression of hTRT in HeLa cells and PG cells was estimated by RT-PCR and the hTRT cDNA encoding the catalytic domain from HeLa cells were cloned and sequenced. Using in situ hybridization (ISH) techniques, the expression of hTRT mRNA in 54 human tumors were observed and compared with the expression of hTR. RESULTS: hTRT was detected in both HeLa and PG cells. Sequencing showed that the cloned hTRT catalytic domain cDNA was identical with that reported in the literature. hTRT and hTR expressions were detected in 38/46 and 40/46 malignant tumors respectively, while both hTRT and hTR were not detected in 8 benign tumors. CONCLUSION: hTRT was detected in both HeLa and PG cancer cells. hTRT catalytic domains were highly conservative. The expression of hTRT and hTR were both high in malignant tumors and they were strongly correlated. Our results suggest that detection of hTRT was valuable to clinical oncology diagnosis.

Catalytic Domain↗
PubMed1999

[Significance of telomerase activity detection by fine-needle aspiration in patients with breast cancer].

OBJECTIVE: To study the telomerase activity in samples of breast fine-needle-aspiration specimens and to investigate its potential clinical implications. METHODS: Ninety nine fine-needle aspiration specimens from 83 patients with breast cancers, 12 with benign lesions and 4 with breast inflammation, were studied for the presence of telomerase activity by a PCR-based telomere repeat amplification protocol (PCR-TRAP). RESULTS: Among 83 fine-needle aspiration specimens from patients with breast cancer, telomerase activity was detected in 61 of 69 cytologic-positive specimens, 5 of 7 cytologic-suspicious specimens and 4 of 7 cytologic-negative specimens. Sensitivity of telomerase activity detection was 84.3% (70/83); the coincidence rate between telomerase detection and cytologic confirmation was 77.1% (64/83). Of 12 specimens from patients with benign breast lesions, 4 were positive for telomerase activity, but 4 specimens from patients with breast inflammation were all negative. The Combined use of cytological and telomerase detection can improve the detection rates from 83.1% (69/83) to 93.9% (78/83). CONCLUSION: Detection of telomerase in breast tissue samples by fine-needle aspiration is a sensitive and specific method, which implies that it would be helpful in preoperative cytological diagnosis of breast cancer.

Biopsy, Needle↗
PubMed1999

[Effects of plasma catecholamines contents on acute cerebral hemorrhage treated with nao yi-an granule].

In order to investigate the efficacy mechanism of Nao Yi-an(NYA) granule on acute cerebral hemorrhage(ACH), 38 cases of ACH were treated with NYA granule(NYA group) or with Western Medicine (WM group). The contents of their plasmal NE, E, and DA before and after treatments were observed. The results showed that the contents of the plasmal NE, E and DA increase remarkably, compared with those of normal control group(P < 0.01), and accompanied by the increase of volume of hemorrhage or the gravity of the disease. After treatment, the contents of the plasmal NE, E and DA in NYA group are notably lower than those before the treatment(P < 0.01), but in WM group, they are not significantly lower than those before the treatment(P > 0.05), and they are strikingly lower in NYA group than in WM group. It is indicated that the NYA group can effectively decrease the contents of plasmal NE, E and DA, to remove cerebrovascular spasm, to relieve cerebral edema, to improve microcirculation of brain tissue, to increase blood and energy supplies, anticerebral secondary ischemia and hypoxia and improve the clinical effects.

Adult↗
PubMed1999

[Efficacy of tianlong xifeng granule (TXG) in the treatment of acute cerebral infarction of ganyanghuafengzheng].

In this article 412 patients with acute cerebral infarction of ganyanghuafengzheng are analyzed in order to compare the efficacy between TXG and xixian tongshuan pill(XTP). The patients were randomly divided into two groups: 305 patients in Group I were treated with TXG, and 107 patients in Group II treated with XTP. The results showed that the curative rate in Group I was 69.84%, while in Group II 46.73%. It is indicated that the efficacy of TXG is superior to that of XTP. No toxicity and side effect were found in the above two groups.

Adult↗
PubMed1999

[Role of apoptosis and bcl-2 gene in the temporomandibular joint development].

OBJECTIVE: Apoptosis involving in embryogenesis and organ formation has been verified, but the possible roles of apoptosis and its related regulative genes have not been clarified. Temporomandibular joint dysfunction (TMD) has increased in incidence and occurred increasingly in young patients. Thus, research on the development and gene modulation is necessary. METHODS: Tdt-mediated dUTP nick end labeling (TUNEL) and mRNA in situ hybridization were used in observation of apoptosis and bcl-2 gene expression in TMJ of SD rats during prenatal and postnatal developmental period. RESULTS: Apoptosis involved in different development periods of condylar cartilage, and the cells of apoptosis mainly located in the proliferative zone and the area between the prehypertrophic zone and the late hypertrophic zone., bcl-2 was expressed in chondrocytes throughout condylar cartilage with high levels in proliferative and prehypertrophic chondrocytes and obvious low levels in the late hypertrophic chondrocytes. Very few matured chondrocytes expressed bcl-2. CONCLUSION: Apoptosis regulated by bcl-2 plays an important role in prenatal and postnatal development of TMJ.

Animals↗
PubMed1999

[Significance of programmed cell death in C57BL/6N strain mouse palate process development and cleft palate formation].

OBJECTIVE: To observe the changes of programmed cell death (PCD) in C57BL/6N strain mouse cleft palate formation and study related gene of PCD in future. METHODS: 16 mice (gestation of 10 days, GD10) were divided into the experimental and control groups randomly, then the mice of the experimental group were dosed with retinoic acid(RA) 80 mg/kg, and the tissue slices of the embryo mouse were prepared for TdT-mediated dUTP nick end labeling (TUNEL) staining at GD13(14)(the 14th hour of the 13th day gestation), GD13(22), GD14(8), GD14(14), GD14(22), GD15(8), GD15(22) and GD16(8) respectively. RESULTS: In the early development of palate process, the positive index of PCD was significantly higher in the experimental group than in the control group (P < 0.05). CONCLUSION: The effects of RA on mesenchymal cells of the early development of palate process in the experimental group induce PCD, which result in the formation of small palate process and failure of fusing of the shelves.

Animals↗
PubMed1999

[Effects of TGF beta on BMP-2 gene transfection cells in vitro].

OBJECTIVE: To elucidate the mechanism of bone morphogenetic protein-2(BMP-2) and transforming growth factor beta(TGF beta) on cell differentiation. METHODS: A phagemid expression vector for human BMP-2 (pBK-B2) was constructed and transfected into the NIH3T3 cells by using lipofectamine. Positive cell clones were selected with G418. The stable transfection and expression of BMP-2 were determined by using in situ hybridization and immunohistochemistry methods. The proliferativity of the transfected cells treated with TGF beta were assayed by MTT method. Alkaline phosphatase (ALP) and osteocalcin (OC) production were also measured. RESULTS: The proliferation of the transfected cells was stimulated after being treated with TGF beta (50 ng/ml). But the ALP activity and OC production were inhibited. CONCLUSION: The effects of TGF beta are closely related to many factors, and BMP and TGF beta may be synergistic in cell proliferation and differentiation.

3T3 Cells↗
PubMed1999

[Cell proliferation and programmed cell death in tooth development].

OBJECTIVE: To evaluate the role of cell proliferation and programmed cell death (PCD) in the tooth development by detecting programmed cell death and expression of proliferating cell nuclear antigen (PCNA). METHODS: Expression of PCNA and PCD were detected by immunohistochemical staining and Tdt-mediated dUTP nick end labelling (TUNEL) in different stages of the tooth development of Sprague-Dawley rats. RESULTS: The positive cells of PCNA and PCD predominantly appeared at the proliferating growth center in the bud, the cap and the earlier bell stages of tooth development. PCNA and PCD were also observed in ameloblasts and odontoblasts, especially in the stellate reticulum cells of enamel organ and dental papilla during the period of dentin formation. CONCLUSION: Cell proliferation and programmed cell death are interrelated and interact on each other in the development of teeth, and they both involve in sculpturing the shape of teeth.

Animals↗
PubMed1999

[Separation and characterization of oligodeoxynucleotide by fast protein liquid chromatography].

The antisense drug synthesized by DNA synthesizer is an oligodeoxynucleotide (ODN). The purity of the drug should be determined effectively. Because the ODNs are molecules with negative charges at pH 12, they can be separated according to the quantity of charges with them on the ion-exchange column. On anion exchange column, MONO-Q, the ODNs ranged from 19 bases to 21 bases can be separated successfully by gradient elution of NaCl solution from 0 mol/L to 1.8 mol/L. The experiment proved that the fast protein liquid chromatography is a very useful tool for the determination of the antisense drug.

Chromatography, Liquid↗
PubMed1998

Inhibition stereochemistry of hydroxamate inhibitors for thermolysin.

N-Acyl-N-hydroxy-beta-amino acid derivatives were prepared and tested as inhibitors for thermolysin to find that these inhibitors show the L-stereospecificity in contrast to the corresponding hydroxamates prepared from alpha-amino acid, which exhibit the D-stereochemistry. N-Formyl-N-hydroxy-beta-L-Phe-NHMe is the most potent inhibitor having the Ki value of 1.66 microM.

Binding Sites↗
PubMed1998

Crystal structure of the MATa1/MATalpha2 homeodomain heterodimer in complex with DNA containing an A-tract.

The crystal structure of the heterodimer formed by the DNA binding domains of the yeast mating type transcription factors, MATa1 and MATalpha2, bound to a 21 bp DNA fragment has been determined at 2.5 A resolution. The DNA fragment in the present study differs at four central base pairs from the DNA sequence used in the previously studied ternary complex. These base pair changes give rise to a (dA5).(dT5) tract without changing the overall base composition of the DNA. The resulting A-tract occurs near the center of the overall 60 degrees bend in the DNA. Comparison of the two structures shows that the structural details of the DNA bend are maintained despite the DNA sequence changes. Analysis of the A5-tract DNA subfragment shows that it contains a bend toward the minor groove centered at one end of the A-tract. The observed bend is larger than that observed in the crystal structures of A-tracts embedded in uncomplexed DNA, which are straight and have been presumed to be quite rigid. Variation of the central DNA base sequence reverses the two AT base pairs contacted in the minor groove by Arg7 of the alpha2 N-terminal arm without significantly altering the DNA binding affinity of the a1/alpha2 heterodimer. The Arg7 side chain accommodates the sequence change by forming alternate H bond interactions, in agreement with the proposal that minor groove base pair recognition is insensitive to base pair reversal. Furthermore, the minor groove spine of hydration, which stabilizes the narrowed minor groove caused by DNA bending, is conserved in both structures. We also find that many of the water-mediated hydrogen bonds between the a1 and alpha2 homeodomains and the DNA are highly conserved, indicating an important role for water in stabilization of the a1/alpha2-DNA complex.

Binding Sites↗
PubMed1998

Cytogenetic and fluorescence in situ hybridization characterization of chromosome 1 rearrangements in head and neck carcinomas delineate a target region for deletions within 1p11-1p13.

Cytogenetic analyses have revealed structural rearrangements of chromosome 1 in a large fraction of head and neck carcinomas (HNCA). These aberrations frequently affect chromosomal band 1p13 and the centromeric region, the latter often in the form of isochromosome i(1q) and whole-arm translocations. To delineate the critical region involved in rearrangements of proximal 1p, we have undertaken a more precise breakpoint mapping in 13 HNCAs, using metaphase fluorescence in situ hybridization with 11 yeast artificial chromosome (YAC) clones spanning 1p. All of the tumors had chromosome 1 changes at G-banding analyses. Fluorescence in situ hybridization showed that in almost all of the cases, at least one copy of chromosome 1 was affected by centromeric rearrangement. By the use of YAC clones mapped to juxtacentromeric regions and a centromere-specific alpha-satellite probe, we detected variable breakpoints in the whole-arm translocations. At the cytogenetic level, 1p13 rearrangements were frequent. However, molecular breakpoints within this band varied among the HNCAs tested. The lack of consistently rearranged chromosome segments indicates that the pathogenetically important consequence of 1p rearrangements in HNCAs is loss and/or gain of genes outside the breakpoint regions. In an assessment of the genomic imbalances, partial or complete overrepresentation of 1q was seen in eight cases. Loss of 1p material was also identified in eight cases; and in four of them, the deleted segments were too small to be discovered by G-banding analysis. The minimal overlapping deleted region was in the interval between YAC 959C4 (band p11-p12) and the centromere (p10). Our findings indicate that a target region potentially harboring tumor suppressor gene(s) crucial for HNCA is located within chromosomal bands 1p11-p13.

Centromere↗
PubMed1998

Human integrin beta3 gene expression: evidence for a megakaryocytic cell-specific cis-acting element.

The human integrin beta3 participates in a wide range of adhesive biologic functions and is expressed in a selected subset of tissues, but little is known about the cis-acting DNA elements or trans-acting factors responsible for this regulation. Using cell lines characterized for beta3 expression, a number of upstream regulatory regions in the beta3 gene were identified. (1) The three regions from -1159 to -584, -290 to -146, and -126 to -115 demonstrated positive, negative, and negative activity, respectively. (2) The region from -115 to +29 of the beta3 gene was sufficient for cell-specific activity. Deletion of the sequence from -115 to -89 produced a 6- to 40-fold reduction in reporter gene activity in beta3-expressing megakaryocytic cell lines (K562, Dami, and HEL), but only a 1.7- and 2.7-fold reduction, respectively, in beta3-expressing endothelial and melanoma cell lines, and 1.3- and 2. 8-fold reduction, respectively, in non-beta3-expressing Chinese hamster ovary and 293 cell lines. This sequence also bound nuclear proteins in a cell-specific manner in electrophoretic mobility shift assays. Mutational analysis indicated that the sequence GAGGGG (positions -113 to -108) is a megakaryocytic cell line-specific cis-acting element. (3) The region from -89 to +29 promoted lower activity in all cell lines. We also provide evidence that a CCCACCC sequence at position -70 has transcriptional activity, most likely through the Sp1 transcription factor. These data supply the first detailed map of the transcriptional regulatory elements of the 5' region of the beta3 gene, define positive regulatory sequences with potent megakaryocyte preferential activity, and indicate that the ubiquitous transcription factor, Sp1, may augment beta3 gene expression.

Animals↗
PubMed1998

[Epidemiological study of airway responsiveness on the patients with asthma].

The analysis of date on 641 nuclear families with asthma declared that the sensity and specify of the airway responsiveness with Methecholone(MTCH) Challenge Test for the clinical diagnosis of asthma is 72 percent and 70 percent. The population with airway hyperresponsiveness was 6.01 times higher risk to asthma than one of negative airway responsiveness. The OR of male and female for asthma was 4.97, 5.06, respectively, and was statistically significant (P < 0.01). Moreover, the risk of asthma was been increasing with MTCH concentration was increased (i.e. degree of airway responsiveness decreased) step by step, as well showed the lineage trend between the asthma and airway responsiveness significantly (P < 0.01). The Measurement of airway responsiveness play an important role in clinic and prevent medicine.

Adolescent↗
PubMed1998

lin-14 regulates the timing of synaptic remodelling in Caenorhabditis elegans.

In the nematode Caenorhabditis elegans six GABAergic motor neurons, known as DDs, remodel their patterns of synaptic connectivity during larval development. DD remodelling involves a complete reversal of the direction of information flow within nerve processes without marked changes in process morphology. We used a marker localized in vivo to DD presynaptic zones to analyse how the timing of DD remodelling is controlled. In wild-type animals, DDs remodel their synaptic outputs within a 3-5-hour period at the end of the first larval stage. We show that the heterochronic gene lin-14, which controls the timing of stage-specific cell lineages, regulates the timing of DD synaptic output remodelling. In lin-14 loss-of-function mutants, DDs remodel precociously. The degree of precocious remodelling is correlated with the level of lin-14 activity. Expression of lin-14(+) in the DDs of lin-14-null mutants rescues the precocious remodelling, indicating that lin-14 can act cell-autonomously. Consistent with this hypothesis, LIN-14 protein levels decrease in the DDs before remodelling. Our observations reveal a role of heterochronic genes in non-dividing cells, and provide an example of cell-autonomous respecification of neuronal connectivity.

Animals↗