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Biomedical subjects

S Chen

Publications and source records attributed to S Chen.

At least 325 records · Page 18Linked to original sources
PubMed2001

[A surgery oriented serial treatments of 191 patients with large primary liver cancer].

OBJECTIVE: To discuss the methods and effects of a series of surgery oriented therapies in the treatment of large primary liver cancers. METHODS: From January 1993 to June 1999, 191 patients with large liver cancer were treated chiefly by operation. The size of the primary cancer varied from 5.2 to 19.7 cm (median 9.4 cm). Various kinds of liver resections were performed in 121 patients and, as a supplement, deep cryosurgery was carried for out the rest 70 patients. Importable drug delivery system (IDDS) was instituted intraoperatively. Transcatheter arterial chemo-embolization (TACE, THP 30-60 mg, E-ADM 20-40 mg, CDDP 40-80 mg, MMC 10-20 mg, iodine oil 5-30 ml), percutaneous ethanol injection (PEI), bioimmunotherapy and the traditional Chinese medicine were used pre- and post-operatively. CT angiography (CTA) and CT during arterial portography (CTAP) were used to find satellite nodules. Early recurrence was diagnosed by AFPmRNA monitor in peripheral blood. Child's classification plus branch chain amino acid/aromatic amino acid (BCAA/AAA) were adopted in evaluating the pre-operative liver functions. RESULTS: Remarkable results were observed after this surgery oriented serial treatment. The 1-, 3- and 5-year survival rates in the resection group were 75.8%, 45.6% and 30.4%, respectively. The 1- and 3-year survival rates in the cryosurgery group were 63.2% and 37.0%. The operative mortality was 1.6%. Recurrence rates were 69.2% in AFPmRNA positive group and 33.3% in AFPmRNA negative group. Comparing this two groups, significant difference was observed (P < 0.05). BCAA/AAA were lower than 1.5 in two patients died after resection. CONCLUSION: A serial treatment with surgery as the chief modality gives satisfactory results in large primary liver cancers. This regimen should be adhered to as a main strategy in dealing with large liver cancers. AFPmRNA in the peripheral blood, signifying a recurrence, may become a hope of a new clinical parameter. BCAA/AAA plus Child's classification is able to evaluate more accurately the hepatic functional reserve before surgery.

Adolescent↗
PubMed2001

[Clinical study on preventing endodontic interappointment pain with dexamethasone].

OBJECTIVE: To investigate the effect decreasing of the incidence of endodontic interappointment pain(EIP) by local injection of 5 mg dexamethasone. METHODS: 5 mg dexamethasone was injected submucosally at apical region of 80 teeth with asymtomatic pulp necrosis after root canal therapy, then observing the incidence of EIP and compared with control group. RESULTS: The clinical observation revealed that the incidence of EIP of dexamethasone group (10.00%) was lower than that of control group (33.75%), P < 0.01, and the level of pain was decreased. Ordinal logistic regression revealed that EIP was related to tooth location, fistula, and root canal therapy. CONCLUSION: The incidence of EIP can be reduced after 5 mg dexamethasone local injected.

Adult↗
PubMed2001

[Gene marking of human colon cancer LoVo cells with enhanced green fluorescent protein].

OBJECTIVE: The aim of this study is to obtain a human colon cancer cell line marked with enhanced green fluorescent protein (EGFP) gene. METHODS: The G1FP retroviral vector, carrying EGFP gene, was constructed. When combined with liposome-mediated transfection with cross infection, EGFP virus producer cells were generated. The human colon cancer LoVo cells were transduced with EGFP retrovirus. The integration and expression of EGFP gene were analyzed with polymerase chain reaction (PCR) and flow cytometry. RESULTS: The ecotropic EGFP virus was obtained by cocultivation of packaging cells for two weeks, while the amphotropic virus producer cells Am12/G1FP, expressing high-level EGFP, were generated through cross infection with a titer of 1.1 x 10(5) infectious particles/ml. The genetically modified LoVo/GFP cells gave off strikingly bright green fluorescence, in which the integration of EGFP provirus was confirmed by PCR analysis. CONCLUSION: The LoVo/GFP cells, which express high-level green fluorescence, may provide an useful tool for the study of micrometastasis of colon cancer in vivo.

Animals↗
PubMed2001

[An epidemiological study on pesticide poisoning with mixed preparation].

OBJECTIVE: To investigate the incidence of pesticide poisoning with mixed preparation and risk factors contributing to it. METHODS: Twenty-five administrative villages were studied in three townships of Jiangsu and Shandong Provinces with cluster sampling. The sampled villages were divided into study group (12 villages) and control group (13 villages) with approximately equal number of people each. Pesticide sprayers in the study group applied mixed preparation containing organophosphorous and dimethrin and those in the control group applied single organophosphorous preparation. All the sprayers in sampled villages were interviewed with a same questionnaire about their situation of pesticide spraying during the observation period. Cases of pesticide poisoning were ascertained by seniors physicians in occupational diseases after group discussion. RESULTS: Incidence of pesticide poisoning was higher in 2 179 sprayers of the study group (10.10 %) than that in 2 615 of the control group (2.29%), with a highly statistically difference (chi(2) = 12.46, P < 0.01) and an risk ratio (RR) of 4.45 (95% CI = 1.94 approximately 10.05) adjusted for other risk factors by logistic regression. Other risk factors for pesticide poisoning with mixed preparation were smoking or taking food during spraying, leaking or breakdown of sprayers, without washing their whole body as soon as possible after spraying, poor personal protection, spraying for a long time, spraying by women and spraying pesticide on cotton. CONCLUSIONS: If toxicity of mixed preparation of single pesticide showed a synergistic or additional effect, risk of poisoning by spraying mixed preparation increased. Health education and technical training should be strengthened for pesticide sprayers.

Adult↗
PubMed2001

[Pathogen detection in the myocardial lesion using in situ RT-PCR in mice induced by experimental CoxB(3m) virus infection].

OBJECTIVE: To detect the location of pathogens in myocardium using in situ RT-PCR technique in order to study the pathogenetic course of the myocardial lesion induced by CoxB(3m) virus infection in mice. METHODS: (1) Thirty and fifty Balb/c mice were used respectively to establish the acute and chronic CoxB(3m) infected models, with another 25 healthy mice as the controls; (2) KS400 image analysis system (Germany) was used to measure the cardiac chamber area and the left ventricular wall thickness of the chronic infected mice and the controls; (3) CoxB(3m) virus in myocardial tissue was detected using in situ RT-PCR by direct incorporated technique which employed nucleotide labeling by anti-digoxin antibody and bonded with alkaline phosphatase (anti-dig-AKP method). RESULTS: Picture analysis indicated that the left ventricular chamber area was enlarged and the left ventricular wall was thinner in the chronic repeated virus infected models than those of the controls. With in situ RT-PCR, positive signals for Coxsackie virus B(3m) RNA were detected not only in the myocardium of the acute Balb/c mice models but also in the myocardium of the chronic mice models. CONCLUSION: Coxsackie virus B(3m) is able to induce pathologic lesions by exhibiting positive CVB-RNA signals in both acute and chronic models in mice. In the chronic experimental models, the cardiac chamber is enlarged while the ventricular wall is thinned which demonstrates the association with persistent infection of Coxsackie virus B(3m) virus.

Animals↗
PubMed2001

[Effects of cervical vertebra rehabilitation pill on antiinflammation and analgesia].

OBJECTIVE: To study the effects of cervical vertebra rehabilitation pill on anti-inflammation and analgesia. METHODS: Hot board and body distortion induced by acertic acid methods were applied in mice for analgesia experiment. Granuloma induced by cotton ball implantation tumefaction in feet induced by carrageenin in rats and auricle tumefaction induced by croton oil in mice were applied for anti-flammation experiment. RESULTS: Cervical vertebra rehabilitation pill could significantly prolong the latent period of pain reaction induced by hot board in mice and markedly decrease the frequency of body distortion induced by acertic acid. Cervical vertebra rehabilitation pill also could significantly inhibit the tumefaction in feet induced by carrageenin, reduce the degree of tumefaction in auricle induced by croton oil in mice and inhibit the formation of granuloma induced by cotton ball implantation in subcutaneous part. CONCLUSION: Cervical vertebra rehabilitation pill has significant effects on anti-inflammation and analgesia.

Analgesics↗
PubMed2001

[Function of vascular endothelial growth factor in ovarian hyperstimulation syndrome].

OBJECTIVE: To evaluate the function of vascular endothelial growth factor (VEGF) and other clinical indexes to forcast ovarian hyperstimulation syndrome (OHSS). METHOD: Collecting the serum and follicular fluid (FF) of 42 cases in the in vitro fertilization and embryo transfer (IVF-ET) cycles and then analysis the relationship of the clinical and detected indexes between the OHSS (10 cases) and the non-OHSS (32 cases). RESULTS: The concentration of VEGF in FF, E2 on the day of human chorionic gonadotropin (hCG) injection, basal luteinizing hormone (LH) and the number of ovum retried much higher in the OHSS than in the non-OHSS. CONCLUSIONS: The concentration of VEGF in FF of OHSS cases is higher than that of controls, supporting the role of VEGF as a mediator of OHSS. Therefore VEGF in FF is a forcast index of OHSS.

Dinoprostone↗
PubMed2001

Cyclohexylamino-demethoxy-hypocrellin B and photodynamic therapy decreases human cancer in vitro.

2-Cyclohexylamino-2-demethoxy-hypocrellin B (CHAHB) is a new photosensitizer synthesized by the mild reaction between hypocrellin B (HB) and cyclohexylamine, in which the peri-hydroxylated perylenequinone structure of the parent HB is preserved and the photoresponse is enhanced markedly. Electron paramagnetic resonance (EPR) spin trapping measurements and 9,10-diphenylanthracene (DPA) bleaching studies were employed to investigate the photodynamic action of CHAHB in the presence of oxygen. Singlet oxygen ((1)O2) and superoxide anion radical (O2*-) generated by illuminating CHAHB in aerobic solution have been observed. Compared with HB, CHAHB distinctly enhanced the O2(*-)-generating abilities, although (1)O2-generating abilities were lowered. The photodynamic action of CHAHB in the therapy of cancer was investigated in vitro. The results in vitro revealed a much more significant decrease in cancer cell growth than with HB. Laser or dye alone had no effect, indicating that intratumor CHAHB and laser therapy may prove useful in unresectable cancer.

Cell Line↗
PubMed2001

[A survey of oral health status of the elderly individuals in Chengdu of China].

OBJECTIVE: The aim of this survey is to investigate the oral health status of the oldsters over 65-year-old in Chengdu of China. METHODS: The oral health status, including oral hygiene, caries, periodontal diseases and the tooth loss of 468 elderly individuals over 65 years old were surveyed and analyzed. RESULTS: It was found that all these older individuals brushed their teeth everyday, but most of them had tooth decay, gingivitis and periodontitis. About 7.47% of them were edentulous, and 2.56% of them were half edentulous. The masticatory ability of most of them declined and the chewing ability of them was low. CONCLUSION: The oral health status of these elderly individuals in Chengdu is poor. It is therefore necessary to improve the health status of this population.

Aged↗
PubMed2001

[Observation on the changes in nasopharyngeal carcinoma patients' olfactory before and after radiotherapy].

OBJECTIVE: Detecting nasopharyngeal carcinoma (NPC) patients' olfactory before and after radiotherapy for investigating the infection of radiotherapy on these patients' olfactory. METHOD: 100 NPC patients' olfactory were detected before the start of radiotherapy and after the termination of therapy in 3, 6, 12, 24 and 36 months. RESULT: Patients' smell acuity decreased sharply 3 months after therapy, but varying degrees of recovery were noted in 6 and 12 months. However their smell acuity became worse in the following time. CONCLUSION: NPC patients' smell acuity can be profoundly affected by radiotherapy. And after radiotherapy, their smell acuity will decrease wave-likely and cannot fully recover.

Adult↗
PubMed2001

[Diagnosis and surgical treatment of carotid body tumor].

OBJECTIVE: To promote the rate of diagnosis and successful rate of operation for carotid body tumor. METHOD: 26 cases of the 30 patients with carotid body tumor were performed by DSA and 5 cases of them, feeding arteries of tumor were embolized with gelfoam through superlective catheterization, preoperativelly. The tumor was resected under carotid adventitial plane in 12 cases, with extracervical artery in 8 cases and with tumor-carotid segment block in 10 cases. RESULT: Of the 30 cases, no one died from operation or cerebral vascular complications. DSA plays a significant role in diagnosis of the tumor. Intraoperative bleeding can be remarkably reduced if feeding arteries were embolized preoperativelly. The tumor fixed to segment of the carotid arteries block was resected and the reconstruction of vasculature was unnecessary as soon as candidates were certified to be qualified by carotid training and DSA or/and TCD tests. Follow up of these 30 patients revealed that 25 of them survived free from cerebrovascular complications and tumor recurrence for 5 months-10 years. 1 of them died from traffic accident 2 year after operation, 4 of them had lost communication. CONCLUSION: DSA is a most authritative approach for diagnosis of carotid body tumor, DSA and TCD tests play a key role to resect carotid artery without reconstruction. Successful operation based on a precise preoperative evaluation, choice of operative ways and proper procedure.

Adult↗
PubMed2001

[Synthesis of galacto-oligosaccharides by immobilized Bacillus stearothermophilus].

Bacillus stearothermophilus was embedded in sodium alginate, chitosan, gelatin respectively and utilized for galacto-oligosaccharides (GOS) production. By comparing with each other in the enzyme recovery, optimal reaction conditions, yields of GOS and mechanical strength of the carriers, the gelatin was selected as better carrier for immobilization. pH, temperature, lactose concentration, lactose conversion and mass transfer resistance of carrier significantly influenced the Yield of GOS. The maximum yield of GOS was 31.2% in a stirred reactor with lactose concentration at 60%. It remained about 88% after 96 h (8 batches) reaction. A packed bed was employed for a continuous reaction at space velocity 0.09 h-1, where GOS yield and reactor productivity was 31.5% and 17.4% respectively. It lost about 20% of its original yield of GOS after 140 h reaction. Products were separated by active charcoal columm. The chemical structure of tetrasaccharide identified by 13C-NMR was beta-D-Gal-(1-->3)-D-Gal-(1-->6)-Dal-(1-->4)-D-Glu.

Alginates↗
PubMed2001

[The different functions of glnB and glnZ from Azospirillum brasilense YU62 in the control of nitrogen fixation].

The glnB and glnZ genes of A. brasilense have 70% homology at nucleotide sequence. glnB is located in a 3.7 kb Eco RI+ PstI fragment and glnZ is located in a 3.7 kb SalI fragment. Both glnB and glnZ genes were mutagenized by Kmr cassette insertions and glnB- and glnZ- mutants were obtained. glnB- mutant did not have any nitrogenase activity, while glnZ- mutant still has nitrogenase activity. The coding regions of glnB and glnZ were cloned into pVK100 vectors and recombinant plasmids pVK-II and pVK-Z were obtained, respectively. The recombinant plasmids pVK-II and pVK-Z were introduced into glnB- and glnZ- to produce C-glnB and C-glnZ, respectively. C-glnB can restore nitrogenase activity and C-glnZ does not have effect on nitrogenase activity. When pVK-II and pVK-Z were introduced into A. brasilense Yu62 and draT-, respectively, the Yu62-II (containing pVK-II) and draT-II (containing pVK-II) have higher nitrogenase activity than that of wild type Yu62. In contrast, Yu62-Z (containing pVK-Z) and draT-Z (containing pVK-Z) has no effect on nitrogenase activity. The nifA(-)-II (containg pVK-II) and nifA(-)-Z (containing pVK-Z) still have no nitrogenase activity.

Azospirillum brasilense↗
PubMed2001

[Cloning sequencing and expression pattern, functional analysis of nifA gene in Azospirillum brasilense Yu62].

The nifA gene of Azospirillum brasilense Yu62 was cloned and sequenced. The expression of nifA gene was investigated in wild type strain Azospirillum brasilense Yu62. The results show that expression of nifA gene is not repressed by ammounium and oxygen completely. But the expression of Yu62 nifA gene is different from that of strain Sp7 nifA gene. Expression of Yu62 nifA seems more sensitive to oxygen than that of Sp7 nifA which shows the highest expression in condition of aerobic, while the Yu62 nifA gene shows the highest expression in the condition of microaerobic. The regulation of NifA protein activity by ammonia and oxygen was investigated. Results showed that the NifA protein is repressed by ammonia, 1 mmol/L NH4Cl can inhibit activity of NifA protein completely. Oxygen concentration affects activity of NifA protein. NifA protein is highly active in 0.4%-0.5% O2.

Ammonium Chloride↗