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Biomedical subjects

J Shen

Publications and source records attributed to J Shen.

At least 235 records · Page 13Linked to original sources
PubMed1999

Arsenic trioxide induces apoptosis of oesophageal carcinoma in vitro.

The arsenic compounds in traditional Chinese medicine have been recorded to have therapeutic effects on the treatment of psoriasis, syphilis, rheumatosis and a number of malignant tumours. Recent studies showed that arsenic trioxide can induce clinical remission in patients with acute promyelocytic leukemia, including those who have relapsed after retinoic acid treatment. however, the mechanism of how arsenic trioxide targets tumour cells is not clearly understood. We have examined the effects of arsenic trioxide on oesophageal carcinoma cell line EC8712. Our results demonstrated that the growth and survival of tumour cells were markedly inhibited by arsenic trioxide. The half dose effect (ED50) was at the concentration of 1 microM. Electron microscopic study demonstrated that EC8712 tumour cells treated with arsenic trioxide display a typical morphological appearance of apoptosis, including chromatin condensation and fragmentation of the nuclei. In contrast, no apoptotic features were observed in tumour cells without arsenic trioxide treatment. TUNEL assay also showed the biological features of apoptosis in cells treated with arsenic trioxide. Flow cytometry analyses showed that apoptotic peak was identified in arsenic trioxide treated cells but not in the control. Apoptotic cells in arsenic trioxide treated group account for 35% of total cell populations after three days treatment at a dose of 3 microM. In short, our results suggested that the anticancer effect of arsenic trioxide is due, at least in part, to the induction of apoptosis in cancer cells.

Antineoplastic Agents↗
PubMed1999

[A gene analysis of familial lipoprotein lipase deficiency in China].

OBJECTIVE: To investigate the gene mutation of lipoprotein lipase(LPL) of familial LPL deficiency in China. METHODS: The DNA sequencing of LPL gene of the patients was performed with the dideoxy method based on the polymerase chain reaction amplification using the genomic DNA as a template. RESULTS: It was identified that a missense mutation in exon 6 of LPL gene (6G(979)-->A) resulted in the substitution of Glu(242) by Lys in a heterozygous state. CONCLUSION: The missense mutation of LPL may play a key role in the decrease of LPL activity. This is the first report about the gene mutation of LPL at this site in familial LPL deficiency. Moreover, it contributes to the elucidation of the pathophysiological mechanisms of atherosclerosis and some metabolic diseases.

Adult↗
PubMed1999

Inhibitory effects of captopril on hypoxia-induced proliferation and collagen synthesis in pulmonary vascular smooth muscle cells.

AIM: To study the effect of captopril (Cap) on hypoxia-induced proliferation and collagen synthesis in vascular smooth muscle cells (VSMC). METHODS: VSMC were isolated from rabbit pulmonary artery. Cultured VSMC were evaluated by incorporation of [3H]thymidine and [3H]proline, cell number, and intracellular calcium concentration ([Ca2+]i). RESULTS: Pretreatment of pulmonary VSMC with Cap 1 mumol.L-1 blocked hypoxia-induced increase in cell number and incorporation of [3H]proline and [3H]thymidine, which were decreased 25%, 21%, and 36%, respectively, as compared with hypoxic control. It also inhibited the increase of intracellular Ca2+ concentration under hypoxic condition. Addition of nifedipine inhibited hypoxia-stimulated increase in the collagen, DNA synthesis, and [Ca2+]i. Bay-K-8644 increased cell number (35%), DNA (55%), collagen synthesis (36%), and [Ca2+]i (33%) in pulmonary VSMC, that was completely abolished by Cap 1 mumol.L-1. CONCLUSION: Cap inhibited hypoxia-induced proliferation and collagen synthesis in VSMC.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1999

[Chromosomal mapping of ld gene which causes congenital limb deformity syndrome in KM-ld mouse].

Fourteen biochemical marker loci and 61 SSLP loci in congenic strain C57BL/6.KM-ld were screened to determine the loci linkage to ld gene, an autosomal recessive mutant gene in KM mouse which causes congenital limb deformity in mouse by means of electrophoresis and PCR amplification. The result showed that ld gene linked to D2Mit30, D2Mit62 and D2Mit63. To locate ld gene more accurately on chromosome 2, 86 backcross offsprings (C57BL/6 x KM-ld) F1 x KM-ld were produced for linkage analysis. From the backcross progeny genomic DNAs were amplified for D2Mit13, D2Mit30, D2Mit62 and D2Mit63 loci in vitro. According to phenotypes, the linkage between the four SSLP loci and ld gene was analysed by calculating genetic distance, ld gene was located exactly on Chr. 2, 76cM, with distances of 25.58cM to D2Mit30, D2Mit62 and D2Mit63, of 31.39cM to D2Mit13.

Animals↗
PubMed1999

[Effects of calcium overload in the conversion of acute edematous pancreatitis to necrotizing pancreatitis in rats].

OBJECTIVE: To investigate the potential of pancreatic acinar cell calcium overload in the conversion of acute edematous pancreatitis (AEP) to necrotizing pancreatitis (ANP). METHODS: Ninety-six Sprague-Dawley rats were randomized in three experimental groups. Sham-operated control (Group I) AEP (Group II) was induced by pancreatic duct ligation and intravenous injection of bombesin (100 micrograms/kg) and secretin (10 micrograms/kg). ANP (Group III) was induced same as group II but with a large dose of dextran 110,000(500 mg/kg) intravenously. Pancreatic acinar cell Ca2+ overload was studied using fluorescent probe Fura2. Cytosolic free Ca2+ concentration ([Ca2+]i) in isolated pancreatic acinar cells and Ca(2+)-ATPase activity in pancreatic cell plasma membranes were determined 1, 3, 6, 9 h respectively after treatment. RESULTS: The results showed that pancreatic acinar cell [Ca2+]i was elevated at 1 h[(213 +/- 19) nmol/L, P < 0.05] and increased to (464 +/- 29) nmol/L at 6 h(P < 0.05) in rats with ANP, pancreatic cell plasma membrane Ca(2+)-ATPase activity decreased significantly from (29.8 +/- 0.4) nmol.min-1.mgp-1 at 1 h to (18.6 +/- 0.5) nmol.min-1.mgp-1 at 9 h in rats with ANP (P < 0.05). CONCLUSIONS: In ischemia-induced conversion of AEP to ANP, there exists Ca2+ overload in the pancreatic acinar cells. The decreased pancreatic cell plasma membrane Ca(2+)-ATPase activity may be an important reason for acinar cell Ca2+ overload in the development of acute pancreatitis.

Animals↗
PubMed1999

[Postprandial triglyceridemia and carotid atherosclerosis in male patients with coronary heart disease].

OBJECTIVE: To test the effect of postprandial accumulation of triglyceride-rich lipoprotein (TGRL) on carotid artery atherosclerosis. METHODS: In 42 male cases with coronary heart disease (CHD) as verified by angiography, high density lipoprotein cholesterol and apolipoprotein B (ApoB) levels in fasting serum, serum triglyceride concentrations before and 2, 4, 6, 8 hours after a standard fat test meal were measured. Each patient underwent a carotid artery high-resolution B-mode ultrasound examination. The extent of alimentary lipemia [area under the triglyceride curve over 8 hours, TG-AUC and peak triglyceride response (TGPR)] correlated with the carotid artery intima-media thickness. RESULTS: Univariate analyses indicated both TG-AUC and TGPR had direct correlation with mean intima-media thickness measured from four well-defined vessel wall segments in the left and right carotid arteries (r = 0.45 and 0.41, both P < 0.01). After controlling for age, body mass index (BMI), triglyceride, HDL-C, and apolipoprotein B concentrations in fasting serum with multivariate stepwise regression analysis, the above correlation remained. There was an independent inverse correlation between HDL-C and carotid artery intima-media thickness. CONCLUSION: It is suggested that abnormal metabolism and clearance of postprandial TGRL can promote the progression of atherosclerosis.

Adult↗
PubMed1999

[Extensive transbasal approach for removal of tumours in the nasal, sphenoid and clival regions].

OBJECTIVE: To improve operative results of removal of the tumors in midline cranial base and the reconstruction of defect at frontal base through modification of the operative approach and techniques. METHODS: Extensive transbasal approach was used in 15 patients with tumours in the nasal, sphenoid and clival regions. RESULTS: The tumor was removed in 10 patients, near totally removed in 4 and partial removed in 1. The operative results of all patients were excellent except an elderly patient with mild operative morbidity. CONCLUSIONS: The procedure we used expand the operative indications for the tumors situated at the midline cranial base and improve the operative results. The procedure has advantages such as wide operative space, reliable reconstruction of the frontal base, and no severe complications.

Adult↗
PubMed1999

[A study on family aggregation of type 2 diabetes mellitus].

OBJECTIVE: To estimate the genetic susceptibility and its relative risk (RR) in the first degree relatives of type 2 diabetes mellitus (DM) through family aggregation analysis. METHODS: A population-based case-control study including 654 pedigrees (363 index cases and 291 controls) was carried out. RESULTS: The prevalence rate in the first degree relatives of DM probands was 3.94%, significantly higher than that in the controls (1.09%), with a relative risk of 3.62 (chi(2) = 36.5, P < 0.001). The RRs in different consanguineal relatives were all higher than 3.0. The younger was the probands at diagnosis for DM, the higher its prevalence rates and RRs among their relatives was and the more likelihood that more than one case of DM occurred in them. CONCLUSION: Significant family aggregation and higher genetic susceptibility were found in the first degree relatives of DM, on whom prevention and treatment for DM should be focused.

Adult↗
PubMed1999

[Experimental study of oxygen supply and demand balance during total hepatectomy and partial liver replantation with venous bypass technique in young pigs].

OBJECTIVE: To investigate the changes of oxygen supply and demand balance during total hepatectomy and partial liver replantation(TCH and PLRP) with venous bypass technique in pigs. METHODS: Seven young pigs[weight (24.2 +/- 4.8) kg] were anesthetized with fentanyl and pentobartal. Catheters were inserted into portal vein via splenic vein and into vena cava inferior via right femoral vein, respectively, and the two catheters were connected by a "Y" adaptor to right atrium via extracorporeal circulation pump. Venous bypass technique was used during occlusion of total hepatic blood stream(OTHB). SvO2, hemodynamics and blood gas analysis were measured after anesthesia, during and 30 minutes after venous bypass. RESULTS: SvO2 was decreased significantly(P < 0.05), vein bypass technique ameliorated partially the disturbance of hemodynamics, and there was correlation between CO and SvO2 during THC and PLRP in pigs. CONCLUSION: The results suggest that there is oxygen supply and demand unbalance during THC and PLRP with venous bypass technique in pigs, and it is beneficial to monitor oxygen ladder during operation.

Animals↗
PubMed1999

Modelling regional migration in China: estimation and decomposition.

"In this paper I consider the issue of identifying the effects of spatial structure and the origin and destination attributes on interregional migration. A decomposition approach is developed based on migration models. The interprovincial migration data in China over the period 1985-1990 are used to estimate a gravity migration model, an extended gravity model, a Poisson gravity model, and a multilevel Poisson model, which are then used to decompose the various effects on migration in China."

Asia↗
PubMed1999

[The clinical characters of tuberculous otitis media].

OBJECTIVE: To sum up the clinical characters of tuberculous otitis media. METHOD: 2 cases of tuberculous otitis media and other reports are reviewed. RESULT: The onset of this disease is sudden and rapid with little discharge coming from the ear. Sometimes one or more perforation and granulation tissue can be found. Necrotizing bone may be seen by radiography. CONCLUSION: According to the tuberculous history of patients or their families and the clinical features, the diagnosis and the treatment to this disease are not difficult.

Adult↗
PubMed1999

[The rebound of nasal resistance after decongestant used in nose].

OBJECTIVE: To investigate the effect of decongestant on nasal resistance so as to provide theories for studing rhinitis medicamentosa. METHOD: The changes of nasal blockage in 92 cases of acute rhinitis and chronic rhinitis after using decongestants were recorded, and the nasal resistance in 39 cases were measured by active anterior rhinomanometry. RESULT: According to the diseases and decongestants used, the percentage of nasal resistance rebound were 63.5%, 31.2%, 32.2%, 8.6% in 4 groups of investigated patients and 50%, 20%, 75% in 3 groups of measured patients respectively. CONCLUSION: Decongestants can cause the rebound of nasal resistance, which related to the diseases and the decongestants used. The mechanism may be that the factors dilating the vasa in nasal mucosa are activated.

Adolescent↗
PubMed1999

[The effects of reactive oxidants on Bacillus thuringiensis parasporal crystals].

The effects of hydrogen peroxides(H2O2) and hydroxyl radicals(.OH) on the purified parasporal crystals from Bacillus thuringiensis var. Kurstaki HD-1 were studied by SDS-PAGE and bioassay. The results showed that to some extent H2O2 and .OH produced a direct and deleterious effect. Hydroxyl radicals from the system Fe(II)-EDTA-H2O2 indicated more serious damage than hydrogen peroxides. There was a 44.5% loss in activity against 12-h-old larvae of Heliothis armigera when parasporal crystals were treated with 0.3% H2O2 only. However, 85.2% activity lost when parasporal crystals were treated with 0.3% H2O2 in the presence of iron(II) and EDTA.

Animals↗