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Biomedical subjects

J Sun

Publications and source records attributed to J Sun.

At least 397 records · Page 22Linked to original sources
PubMed1998

A serpin gene cluster on human chromosome 6p25 contains PI6, PI9 and ELANH2 which have a common structure almost identical to the 18q21 ovalbumin serpin genes.

The human genes encoding the "ovalbumin" subgroup of closely related serine proteinase inhibitors (serpins) are located at 18q21.3 and 6p25. Those at 6p25 include proteinase inhibitor 6 (PI-6; gene symbol PI6), proteinase inhibitor 9 (PI-9; gene symbol PI9) and monocyte neutrophil elastase inhibitor (M/NEI; gene symbol ELANH2). Here we describe the fine mapping of these genes to a 200-kb region of chromosome 6 that includes the markers WI-8835 and D6S1338, and the establishment of the gene order: tel-PI6-PI9-ELANH2-cen. PI6 and ELANH2 are transcribed towards the telomere, and structural analysis shows that PI6 and PI9 are organized identically, having seven exons and six introns. PI6 and PI9 are almost identical in structure to the ovalbumin serpin genes at 18q21.3. The 18q21.3 genes have an extra exon and intron, otherwise all the other exon/intron boundaries are conserved between the two groups. These results represent the first detailed map of the chromosome 6 serpin gene cluster, and demonstrate that although they are very closely related, the 6p25 and 18q21-->q23 ovalbumin serpin genes form two structurally distinct groups. These findings do not support a previously proposed model for evolution of the clusters which invoked an inter-chromosomal duplication of the entire 6p25 group to 18q21.3.

Chromosome Mapping↗
PubMed1998

Transcription activation by the human estrogen receptor subtype beta (ER beta) studied with ER beta and ER alpha receptor chimeras.

We have studied the two estrogen receptor (ER) subtypes, ER alpha and ER beta, and chimeric constructs with ER alpha and ER beta to examine the bioactivities of these receptors and their responses to estrogen and antiestrogen ligands. Transcriptional activity of ER beta is highly dependent on cell/promoter context and on the nature of the ligand. ER beta activated significant levels of transcription in response to estrogens in certain cell types, but showed only moderate activity compared with ER alpha in others. Antiestrogens such as tamoxifen and 2-phenylbenzofuran, which show some agonistic activity with ER alpha, exhibit no agonistic activity with ER beta. Alteration of the amino-terminal A/B receptor domain can result in a dramatic change in cell type- and ligand-specific transcriptional activity of ER beta. Upon replacing the A/B domain of ER beta with the A/B domain of ER alpha, this receptor chimera not only exhibits an improved transcriptional response to estrogens, but also is now able to activate transcription upon treatment with these antiestrogens. As antiestrogen agonism was lacking in ER beta and the ER beta/alpha chimera containing the amino-terminal A/B domain of ER beta fused to domains C through F of ER alpha, but was restored in an ER alpha/beta chimera containing the A/B domain of ER alpha, antiestrogen agonism was shown to depend on the A/B domain (activation function-1-containing region) of ER alpha. Together, these results indicate that the differences in the amino-terminal regions of ER alpha and ER beta contribute to the cell- and promoter-specific differences in transcriptional activity of these receptors, and their ability to respond to different ligands, thus providing a mechanism for differentially regulated transcription by these two ERs.

Amino Acid Sequence↗
PubMed1998

Sequencing of a gene encoding a member of the mitochondrial carrier family of transport proteins from Aspergillus nidulans.

Mitochondrial carrier proteins comprise a superfamily of evolutionarily conserved proteins that regulate the specific transport of essential metabolites across the mitochondrial membranes. In this report we describe the cloning and sequencing of a gene from Aspergillus nidulans, amc-1, that encodes the first reported example of a mitochondrial carrier protein in Aspergillus species. The amc-1 gene is located on chromosome 7, and is transcribed as a 1.6 kb unspliced polyadenylated RNA. The predicted translation product of the amc-1. cDNA displays three tandemly repeated domains which possess protein signature motifs that are characteristic of mitochondrial carrier proteins that localize to the inner mitochondrial membrane. amc-1 shares the greatest similarity with a Neurospora mitochondrial carrier protein that is implicated in basic amino acid transport, suggesting that the amc-1 protein may provide a related function.

Amino Acid Sequence↗
PubMed1998

Radioimmunoassay of human cardiac acidic isoferritin: a new index for hepatic cancer.

OBJECTIVE: To investigate human cardiac acidic isoferritin as a specific index of hepatic cancer. METHODS: Acidic isoferritin was isolated and purified from human heart muscle. A radioimmunoassay for the acidic isoferritin in human serum has been developed, on the equilibrium method. The antiserum was obtained from rabbits immunized with purified acidic isoferritin. The 125I-acidic isoferritin was prepared by the chloramine-T method. The data were processed using the automated smoothed spline function data processing program. RESULTS: The intra- and inter-assay CV of acidic isoferritin RIA were 1.65% and 9.71%, respectively, and the recovery rate was 102%. The antiserum provided a linear response from 7.0 to 369.6 micrograms/L with ED50 of 27.50 micrograms/L. The cross reactivity with AFP, CEA, lactoferrin and transferrin was negligible, and that with ferritin was 1.74%. The serum acidic isoferritin concentration showed a considerable variation in different sex and age groups. The serum acidic isoferritin was measured in liver diseases including hepatic cancer, hepatic cirrhosis and acute and chronic hepatitis. Its sensitivity for diagnosis of hepatic cancer was 73.05%, independent from the severity of hepatic injury. In 8 malignant tumors studied, acidic isoferritin appeared the most valuable in the diagnosis of hepatic cancer, with its positive, negative, false positive and false negative rates all being ideal. CONCLUSIONS: Acidic isoferritin may turn to be a rather specific index of hepatic cancer. Combination of monitoring both acidic isoferritin and AFP would raise the positive detection and specificity in the diagnosis of hepatic cancer.

Biomarkers, Tumor↗
PubMed1998

[The clinical value of tissue polypeptide antigen in ovarian carcinoma].

OBJECTIVE: To evaluate the clinical usefulness of tissue polypeptide antigen (TPA) in diagnosis and monitoring the course of patients with ovarian carcinoma. METHODS: Serum levels of TPA and cancer antigen 125 (CA125)were measured by radioimmunoassay in 60 patients with advanced ovarian carcinoma (41 with active disease and 16 with nonactive, 3 with metastatic tumor from gastrointestinal carcinoma), 24 healthy women and 27 benign gynecologic tumors. RESULTS: The serum TPA and CA125 levels were elevated in 82% and 70% of patients with ovarian carcinoma respectively, the total positive rate of the two markers was 92%. TPA and CA125 levels were within normal range among most of healthy women and patients with benign tumors. TPA and CA125 levels were also correlated with the regression or progression of the disease. CONCLUSION: Combined measurement of TPA with CA125 was useful for the differential diagnosis and achieving higher positivity in patients with epithelial ovarian carcinoma.

Adult↗
PubMed1998

[Effect of crystalling temperatures on microstructure of dental glass-ceramic].

To know well the effect of crystalling temperature on the microstructure of dental glass-ceramic, the parameters of microstructure such as the type of crystal, crystal percentage, crystal size and crystal form were investigated by altering crystalling temperatures and using scanning electronic microscope, energy dispersive X-ray analysis and X-ray diffraction techniques. The results showed that the crystalline phase was identified to be tetrasilicic fluromica, and the promotion of crystalling temperature contributed to the increased crystal percentage, crystal size and the transformation of crystal form from 830 degrees C to 950 degrees C.

Crystallization↗
PubMed1998

[Clear cell carcinoma of vagina: report of 3 cases and review of literatures].

OBJECTIVE: To summarize the clinical characteristics and treatment of vaginal clear cell carcinoma. METHODS: 3 cases of vaginal clear cell carcinoma admitted from 1958-1996 were analyzed retrospectively. RESULTS: Neither intrauterine diethylstilbestrol exposure nor diethylstibestrol use during their life was found in 3 cases. After external pelvic radiation and intracavitary 137Cs radiotherapy, 5-year survival was achieved in all 3 cases. 2 of them were alive with tumor free for 16 years. CONCLUSION: The results suggested that the prognosis of vaginal clear cell carcinoma was rather good and it could be cured by proper radiotherapy.

Adenocarcinoma, Clear Cell↗
PubMed1998

[The clinical evaluation of endometrial carcinoma following irradiation for cervical cancer].

OBJECTIVE: To study the characteristics and clinical features of endometrial carcinoma occurred after pelvic irradiation. METHODS: Clinical data of 27 cases of endometrial carcinoma occurred after irradiation for cervical cancer were reviewed, estrogen receptor (ER) and progesterone receptor (PR) status were studied in 17 cases by immunohistochemistry. RESULTS: The incidence of endometrial carcinoma occurred following pelvic irradiation was 0.19%. The mean age of patients was 63 year old. The mean incubation period from pelvic irradiation to diagnosis of the disease was 15.6 years. The proportion of advanced cases was 51.9% (14/27). The expression of ER and PR was very low (11.8%, 2/17). The original sites of 5 cases with stage I were in fundus or corner of the uterus, which received lower dose irradiation formerly. Operation was the best choice of treatment, 19 out of 27 cases received this modality. The survival rate of 3 and 5 year was 56.8%, 37.8%, respectively. CONCLUSION: The incidence of endometrial carcinoma occurred following pelvic irradiation for cervical cancer was higher than that of cancer occurred spontaneously, the proportion of advanced cases was high, the expression of ER and PR was very low, operation was the mainly method of treatment. The prognosis was poorer than that of spontaneous disease.

Aged↗
PubMed1998

[Telomerase activity in human primary endometrial carcinoma].

OBJECTIVE: To investigate the possible relationship between telomerase expression and progression of endometrial carcinoma. METHODS: Thirty-four primary endometrial carcinoma and 6 normal endometrial tissue specimens were examined by means of telomeric repeat amplification protocol (TRAP) assay for telomerase activity. RESULTS: Of 34 endometrial cancer specimens, 28 (82.4%) showed telomerase activity, whereas 1 of 6 (16.7%) benign endometrial tissues exhibited telomerase activity. CONCLUSION: Telomerase expression might contribute to the progression of endometrial carcinoma and could be used as its tumor marker.

Adenocarcinoma↗
PubMed1998

[The effect of recombinant tissue inhibitor of metalloproteinase-3 (TIMP-3) on tumor growth and metastases].

OBJECTIVE: To investigate the anti-cancer effect of tissue inhibitor of metalloproteinase-3 (TIMP-3) and its mechanism of action. METHODS: Recombinant TIMP-3(rTIMP-3) was prepared and used to study its effect on tumor growth and metastases in mice, and its effect on angiogenesis in chicken embryo allantoic membrane (CAM). RESULTS: rTIMP-3 was able to inhibit growth of subcutaneously implanted S180 sarcoma and hepatic carcinoma H22 in a dose-dependent manner. When the rTIMP-3 was given i.p. at a daily dose of 20 mg/kg body weight for 10 days, the growth of S180 sarcoma and H22 carcinoma was inhibited by 63.2% and 73.4%, respectively. The metastases of i.v. injected Lewis lung carcinoma(3LLC) was also suppressed by rTIMP-3, with an inhibition rate of 59.8%. rTIMP-3 was found to significantly inhibit angiogenesis in CAM assay. CONCLUSION: rTIMP-3 has anti-cancer activity, and the mechanism of action might be associated with its inhibition on extracellular matrix degradation and anti-angiogenesis.

Animals↗
PubMed1998

[Ovarian metastasis from endometrial carcinoma: a report of 22 cases].

OBJECTIVE: To study the clinical characteristics of ovarian metastasis from endometrial carcinoma and its relation to pathologic features and prognosis. METHODS: Twenty-two cases of histologically confirmed ovarian metastasis from endometrial carcinoma were retrospectively reviewed. Prognostic factors such as clinical staging, grade, myometrial infiltration, recurrence and treatment methods were analyzed. RESULTS: The median age of this series was 50.6. Incidence of ovarian metastasis accounted for 4.4% in the same period. Ten out of 22 cases were in clinical stage I, 6 in stage II, and 6 in stage III. The treatment of choice was operation combined with radiotherapy. The overal 5- and 10-year survival rate was 61.5 and 55.9%, respectively. CONCLUSION: Ovarian metastasis from endometrial carcinoma is associated with poor prognosis. Aggressive treatment after operation is required. For young patients in early stage of the disease, circumscript attitude should be taken as to preserve the ovary or not.

Adenocarcinoma↗
PubMed1998

[Detection of TCR gamma gene in acute lymphoblastic leukemia after remission and its clinical significance].

OBJECTIVES: To investigate the quantitative evaluation of chemotherapy efficiency in patients with acute leukemia and its clinical significance. METHODS: Clonal rearrangement of T-cell receptor gamma gene in ALL was detected quantitatively by using competitive PCR. RESULTS: One handred and fifty-eight samples were collected from 54 childhood ALL. The median follow-up duration was 33.5 months. At remission, the amount of leukemic cells in 36 cases was less than 1 x 10(-5), and in 18, was (354 +/- 327) x 10(-5). The efficiency of induction therapy was related significantly to the amount of the detectable residual leukemic cells in the early remission phase and to clinical relapse. In some patients in remission, the amount of leukemic cells persistently under 1 x 10(-5) without clinical relapse. CONCLUSION: Quantitative evaluation of the chemotherapy efficiency is helpful for individualized treatment.

Child↗
PubMed1998

[Anatomical consideration for the injury of dacryocyst and nasolacrimal duct during intranasal sinus surgery].

Based on dissection and measurement on 20 adult head cadavers, there is the close relationship between lacrimal duct and lateral wall of the nasal cavity. The cells of anterior ethmoid sinus were classified into three degrees, according to the relationship between the anterior ethmoid sinus and the lacrimal sac fossa. The average distance is 6.74 +/- 1.72 mm between the nasolacrimal duct and the upper part of the uncinate process, 3.44 +/- 0.75 mm and 5.50 +/- 3.73 mm from the nasolacrimal duct to ethmoidal infundibulum and the maxillary ostium. The orifice of the duct most commonly opens under the insertion of the inferior turbinate anteriorly. To perform intranasal sinus surgery, the safest area and key operation approach were discussed.

Adult↗
PubMed1998

[The preparation of chiral column of cellulose triacetate coated on small pore silica gel and the separation of enantiomers].

The cellulose triacetate (CTA) prepared by heterogeneous acetylation and coated on small pore 3-aminopropyl silica gel (10 nm) was used as chiral stationary phase for HPLC (OA column). The racemes of three drugs, two fulvenes and one dazine, were separated on this column. Among these racemes, timolol maleas was separated using 1.0 mol/L NaClO4:95% ethanol = 10:90 as mobile phase. Without NaClO4 in mobile phase, the resolution of timolol maleas can not occur. Ethanols of 95%-98% were used as mobile phase for other racemes. The influence of the content of water in mobile phase on the chiral separation of praziquentelum, the retention time and separation factor (alpha) were reduced with the increase of water content in mobile phase. When the content of water in the mobile phase was 13%, praziquentelum could not be separated. It was found that in the case of samples No. 1 and No. 2, when the substituents R1 and R2 or R'1 and R'2 of fulvenes are 4-methoxybenzoyl and 4-methoxyphenyl, the chiral separations of fulvenes can be obtained. For sample No. 4 when R1 and R2 of fulvenes are 2-methylbenzoyl and 2-methylphenyl or in the case of No. 5, when R1 and R2 are 5-bromo-2-furoyl and 5-bromo-2-furan, the chiral separations of fulvenes can not be achieved. For sample No. 6 and No. 7, when R'1 are 4-chlorobenzoyl and benzoyl or R'2 are 4-chlorophenyl and phenyl, the chiral separation also can not be achieved. The column performance and separation factor were not obviously reduced after used for four months.

Cellulose↗
PubMed1998

[Pressure control system for the hermetically sealed cabin of the recoverable satellite].

There are many precision instruments and equipment for scientific researches and experiments in the hermetically sealed cabin of satellite. Appropriate pressure must be controlled in the cabin in order to ensure the instruments and equipment from the adverse space environment. This paper describes a pressure control system for the hermetically sealed cabin in the recoverable scientific detect and experimental satellite. The cabin pressure is regulated automatically into the specific levels by venting or supplying the air from or to the cabin during launch, on orbit and before reentry of the satellite. The system has low mass, low power consumption and high reliability. It was used successfully in the recoverable satellite first in September 1987 and had been used many times since then. It is the first active pressure control system for the hermetically sealed cabin of the satellite in China.

Atmospheric Pressure↗
PubMed1998

[Diagnosis and surgical treatment of intramedullary epidermoid cyst of the spinal cord].

OBJECTIVE: To discuss clinical diagnosis and surgical treatment of intra-medullary epidermoid cyst. METHODS: Ten intramedullary epidermoid cysts were confirmed by operatively and pathologically from 1978 to 1995. RESULTS: The tumors were located in the spinal cord. Clinical presentation of this tumor was not specific. On CT scans, eight tumors were characterized by a homogenous low-density lesion and well-defined limits. They usually did not enhance with contrast medium. On MR imaging, four tumors were characterized by an important variability of signal intensity, well-defined limits. All patients underwent resections of epidermoid cyst, 1 total resection, and 9 subtotal resections. Eight cases were followed up from half a year to seven years. No case recurred. CONCLUSION: Total resection of epidermoid cyst is the best choice.

Adolescent↗
PubMed1998

[Primary culture and immunocytochemical identification of spiral ganglion neurons in postnatal Wistar rats].

OBJECTIVE: To create a cytological model of spiral ganglion neurons in postnatal mammals in vitro. METHODS: The primary culture of spiral ganglion neurons (SGN) was carried out with seven-day postnatal Wistar rats. The process of cellular growth and differentiation of SGN were observed by fluorescent microscope and inverted/phase contrast microscopy. Immunocytochemical identification was performed on the cultured SGN of Wistar rats by methods of S-P and the monoclonal antibody of neurofilament protein (NFP-McAb). RESULTS: The present work showed that the dissociated SGN of Wistar rat could survive well and had a normal phenotypic differentiation in vitro. The cell amount and surviving period of SGN were able to meet the requirements of cytological experiments. The stable neuronal plasticity of SGN existed in the postnatal mammal under the present experimental conditions. CONCLUSION: This method extends the material sources of inner ear tissue culture and provides a useful approach to the neurobiologic studies on the peripheral auditory system in vitro.

Animals↗