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Biomedical subjects

G Sun

Publications and source records attributed to G Sun.

At least 199 records · Page 11Linked to original sources
PubMed1996

[Surgical treatment of pulmonary metastasis from renal cancer: analysis of 9 cases].

Nine patients with pulmonary metastasis from renal cancer were subjected to surgical treatment which included wedge resection (2 cases) and lobectomy (9). One case of multiple lesions in bilateral lungs was treated in the same time by cryosurgery and fulguration. The survival time after operation ranged from 5 to 90 months. In this series, four cases are still alive, others survived for 13 months, 20 months, 34 months, and 90 months, respectively. We suggest that the more active attitude should be taken for the surgical treatment of pulmonary metastasis.

Adenocarcinoma, Clear Cell↗
PubMed1996

[Female idiopathic urethra tumor: clinical features diagnosis and treatment].

Female idiopathic urethra tumors are reported rarely. We treated fourteen patients patients, and described the clinical manifestations and local features of the tumors, urethra liomyoma, and fibropolypus. We found that there are close relations among tumor stage, prognosis and pathological classification. The main diagnostic methods include vaginal touch, urethroscopy, B-ultrasound exam and biopsy. The diagnostic procedure recommended is tumor location-quality-stage or a three-step method. The main treatment is operation, however, the operative mode should depend on tumor stage and patient's life quality after operation.

Adenocarcinoma↗
PubMed1995

Methyl (2S,6S:2R,6R)-6-(2-cyanoethyl)-4,6-dimethyl-2-morpholineacetate.

The morpholine ring of the title compound, C12H20N2O3, adopts a chair conformation with an equatorial (methoxycarbonyl)methyl group. The cyanoethyl and (methoxycarbonyl)methyl groups are trans with respect to each other. The global minimum conformation, as computed by PCMODEL [Gajewski & Gilbert (1992). Molecular Modeling Package. Version 4.0], of the title compound agrees with that observed in the crystal. In the crystal, the torsion angles (N identical to)C-CH2-CH2-C(O), (N identical to C)CH2-CH2-C-O, O-CH-CH2-C(OOCH3) and (O)CH-CH2-C(O)-O(CH3) have values -170.0 (1), -45.9 (2), -71.6 (2) and 142.8 (1) degrees, respectively.

Chemical Phenomena↗
PubMed1995

Tumor necrosis factor-alpha-dependent activation of a RelA homodimer in astrocytes. Increased phosphorylation of RelA and MAD-3 precede activation of RelA.

Rel proteins are important intracellular mediators of cytokine-induced signal transduction. To understand how cytokines affect different cell populations in the brain, we have characterized Rel activation in astrocytes. A RelA homodimer is uniquely activated in cytokine-stimulated astrocytes. Cytokine-dependent phosphorylation of the RelA inhibitor MAD-3 occurred on discrete peptides prior to its dissociation from RelA. A transient hyperphosphorylation of RelA was also induced. Antioxidant treatment inhibited both RelA activation and phosphorylation of the RelA.MAD-3 complex. These results demonstrate that cytokine-dependent activation of the RelA homodimer involves phosphorylation of both RelA and its associated inhibitor. The sole activation of a RelA homodimer suggests that cytokines will activate a unique set of Rel-regulated genes in astrocytes.

Animals↗
PubMed1995

Production and characterization of monoclonal antibodies against the recombinant p50csk protein tyrosine kinase: a tool for signal transduction research.

p50csk is a protein tyrosine kinase (PTK) that has been reported to regulate the activity of other PTKs belonging to the src gene family. Several hybridoma clones that produce monoclonal antibodies (MAbs) directed against recombinant p50csk were established. Five of the clones were analyzed for their ability to recognize native and denatured p50csk protein after undergoing native and denaturing polyacrylamide gel electrophoresis followed by western blotting. In addition, the clones were tested for their ability to immunoprecipitate p50csk and yet maintain tyrosine kinase activity of antibody-bound p50csk. None of the clones cross-reacted with pp60c-src, a PTK that shares with p50csk the homologous SH1 catalytic domain and SH2 and SH3 regulatory domains. These MAbs can be used to study p50csk directly, and its role in regulating members of the src family.

Animals↗
PubMed1995

[The effect of retinoic acid on DNA synthesis of fibroblast in vitro culture].

The effect of retinoic acid on DNA synthesis of fibroblast was studied in vitro culture. The results demonstrated that retinoic acid significantly (P < 0.01) inhibited the DNA synthesis of fibroblast in vitro culture and a dose-dependent relationship between DNA synthesis and retinoic acid concentration was observed. The possible mechanism of retinoic acid used for the treatment of scar was discussed.

Cells, Cultured↗
PubMed1995

Inhibition of protein kinases A and G by hydralazine but not KRN2391 in vitro.

AIM: To examine possible direct effects of the vasodilators hydralazine and KRN2391 on the activities of protein kinase A (PKA), protein kinase G (PKG), and protein kinase C (PKC). METHODS: PKA, PKG and PKC were extracted from bovine lung, heart and rat brain and purified to homogeneity by chromatography. The effects of different reagents on these protein kinase activities were determined in vitro. RESULTS: Hydralazine (0.03-10 mmol.L(-1)) inhibited the activities of both PKA and PKG with IC50 of 1.2 and 2.5 mmol.L(-1), respectively, but had little effect on PKC. KRN2391 (1-1000 mumol.L(-1) had no effects on PKA, PKG, or PKC. Using H-89 and GF109203X, inhibitors relatively selective to PKA and PKC respectively, as controls, we obtained inhibitions on PKG, PKA, and PKC similar to literature. However, a novel PKG inhibitor KT5823 failed to inhibit PKG or PKA. CONCLUSION: Hydralazine alters the activity of PKG and PKA, which may have implications for the vasodilator activity.

Animals↗
PubMed1995

[The study of GST mu gene deletion as the hereditary marker for susceptibility to lung cancer].

A total of 175 lung cancer patients and 104 controls were detected for GST mu gene using PCR technique. The results showed that the GST mu gene deletion rate in lung cancer patients was 71.4%, which was significantly higher than the controls, 51.9%. Analysis according to pathological classification of lung cancer indicated that the GST mu gene deletion rate in all three kinds of pathological types-squamous, adenocarcinoma and small cell carcinoma, were markedly higher than that of controls, especially for small cell carcinoma (the deletion sate is 77.5%). The frequency of GST mu gene was not associated with smoking in both groups, but the higher deficiency rate was found in the low age group of lung cancer patients, showed 85.3% compared to the high age group, 68.1%. All the results showed that GST mu gene deletion may be an important host hereditary marker for susceptibility to lung cancer.

Adenocarcinoma↗
PubMed1995

[Effects of some physical and chemical factors on both human hair DNA and results of sex determination by PCR].

The present study aims at observation of the effects of some physical and chemical factors on both human hair DNA and the results of sex determination by PCR. After the hairs were treated with varying pH solutions, the quantity of the DNA extracted was decreased. High-molecular-weight (HMW) DNA was determined in the hairs treated with pH 1, 3, 5 and 7 solutions for 2 hours, but no DNA was demonstrated by agarose gel electrophoresis in the hairs treated with pH 1 and 3 solution for 24 hours, and the quantity of DNA was decreased in the hairs treated with pH 5 for 24 hours. The quantity of DNA was decreased in the hairs treated with pH 9 for 2 hours and no DNA was demonstrated for 24 hours. No DNA was found in the hairs treated with pH 11 for 2 or 24 hours. No changes of DNA were observed in hairs treated with 75% ethanol or methanol for 2 or 24 hours and exposed to UV light for 24 hours. No DNA but RNA was observed in the hairs treated with 10% formalin (pH 7 or pH 5) for 2 or 24 hours. The quantity of DNA was decreased obviously in the hairs treated in 100 degrees C water for 5 or 10 minutes. The quantity of DNA was not decreased in the hairs heated at 50 degrees C for 24 hours, and only little decrease was noted at 100 degrees C for 24 hours. Both fragments of PCR products were obtained in most hairs except the hairs treated with pH 11 solution for 24 hours. Although no DNA was observed in some treated hairs, specific bands were detected after PCR. PCR is a very sensitive and specific technique of DNA amplification, which can be used for sex determination in forensic medicine.

Base Sequence↗
PubMed1995

[Simultaneous nasal reconstruction and facial defect repair using expanded forehead flap].

The expanded forehead flap has been used to reconstruct the nose and repair facial defects simultaneously since Sept. 1991. During operation, the expanded flap was divided into two parts: one based on the supratrochlear vessels for nasal reconstruction, the other based on the frontal branch of the superficial temporal vessel for the facial defects, e.g. periorbital or zygomatic area, upper or lower lip. Four patients were treated with this method and satisfactory results obtained.

Adolescent↗
PubMed1995

[Full-load expansion techniques and preliminary clinical application].

For accelerating the inflation process of soft tissue expansion, a continuous inflation protocol regarding pain as the criterion of over-inflation, the full-load expansion technique, was introduced. It is carried out by restricting persistently the pressure in the expander near the pain threshold in a state of dynamic equilibrium between the infusing rate and the skin expansion velocity, with a simple and practical assembled device. This inflation is neither at a uniform infusing rate nor at a constant filing pressure. 19 expanders in 13 patients were inflated following this protocol. Their inflations were respectively fulfilled in 5 to 20 days, depending individually on their anatomic regions, total volumes of infusion, areas of the overlying skin and the patient susceptibilities.

Alopecia↗
PubMed1995

[Studies on bacterial metabolism pathway of 2-naphthoic acid].

The missing chemical Link (Phthalate) of bacterial metabolism pathway for 2-naphthoic acid has been identified to be existing. The genetic regulation mechanism of 2-NAT strain for 2-naphthoic acid metabolism is also investigated with plasmid curing, transposon Tn10 mutagenesis and mutation reversion experiments. It is discovered that 2-NAT strain carries at least one plasmid. The plasmid and the chromosomal DNA co-encode and control the bacterial metabolism pathway for 2-naphthoic acid.

DNA Transposable Elements↗
PubMed1994

A pho regulon promoter induced under sporulation conditions.

Sporulation-induced alkaline phosphatases (APases) of Bacillus subtilis require the products of the sporulation stage-0 genes and certain stage-II genes, including the spoIIA operon, for induction. Mutations in either sapA or sapB bypass this requirement [Piggot and Taylor, J. Gen. Microbiol. 10 (1977) 69-80], resulting in APase production in a spoIIA sapA or spoIIA sapB strain, under sporulation conditions. B. subtilis has multiple structural genes encoding APases, which are induced either by phosphate starvation or during sporulation, or under both conditions. We report studies designed to determine which APase(s) were being expressed in the sap mutants, and from which promoters. phoB (formerly phoAIII), one of the structural genes encoding an APase in B. subtilis, is expressed under both sporulation and phosphate starvation conditions, but from separate promoters [Chesnut et al., Mol. Microbiol. 5 (1991) 2181-2190]. The spoIIA sapA and spoIIA sapB strains express phoB under sporulation conditions. Interestingly, the expression of phoB during sporulation was from Pv, the phosphate starvation-inducible promoter of phoB, rather than from Ps, the sporulation-specific promoter. Since the induction of phosphate starvation-inducible promoters during phosphate limitation requires the phoPR operon [Miki et al., Genetics 52 (1965) 1093-1100], we asked if the phoPR products were involved in regulating Pv expression under sporulation conditions. The phoPR genes are transcribed under sporulation conditions, regulated by sapA and sapB under sporulation conditions, and required for expression from Pv under sporulation conditions.

Alkaline Phosphatase↗
PubMed1994

Full-load expansion technique and preliminary clinical application.

For accelerating the inflation process of soft-tissue expansion, a continuous inflation protocol regarding pain as the criterion of overinflation, the full-load expansion technique, has been introduced. It is carried out by restricting persistently the pressure in the expander near the pain threshold in a state of dynamic equilibrium between the infusing rate and the skin expansion velocity with a simple and practical device. This inflation is neither at a uniform infusion rate nor at a constant filling pressure. Nineteen expanders in 13 patients were inflated following this protocol. Their inflations were fulfilled in 5 to 20 days, depending individually on their anatomic regions, total volumes of infusion, areas of the overlying skin, and patient susceptibilities.

Adult↗