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Biomedical subjects

W Li

Publications and source records attributed to W Li.

At least 775 records · Page 43Linked to original sources
PubMed1998

[Garlic oil induces differentiation and apoptosis of human gastric cancer cell line].

OBJECTIVES: To study the mechanism of garlic oil-induced differentiation of human gastric cancer cell line BGC-823. METHODS: Confocal microscopic assay and Northern blot hybridization were used to detect morphological change and gene expression in garlic oil treated human gastric cancer cells (BGC823). RESULTS: Cell growth in vitro and tumorigenicity in nude mice were inhibited dramatically by garlic oil. Garlic oil treatment resulted in cell apoptosis as shown by DNA fragmentation. High expression level of WAF1/p21 and wild type p53 gene was detected in garlic oil-treated cells. CONCLUSION: These data indicate that differentiation and apoptosis of BGC-823 cell can be induced with garlic oil, and p21 and p53 genes possibly play important role in the process.

Allyl Compounds↗
PubMed1998

[Effect of recombinant human growth hormone on hypoalbuminemia in peritoneal sepsis: experimental and clinical research].

OBJECTIVE: To investigate the effect of recombinant human growth hormone(rhGH) on hypoalbuminemia in peritoneal sepsis. METHODS: We observed rhGH on albumin mRNA expression and albumin sythesis in vitro and in vivo with the method of reverse-transcriptional polymerase chain reaction (RT-PCR). RESULTS: rhGH significantly up-regulated albumin mRNA expression in vitro (143 +/- 6 vs 100.4 +/- 2.2, P < 0.01) and in vivo(152 +/- 8 Vs 100 +/- 3, P < 0.01), and obviously alleviated the inhibition of albumin mRNA expression induced by LPS (P < 0.05). In cecal ligation and puncture-induced septic rats, rhGH significantly raised albumin synthesis(20.4 +/- 1.7 Vs 15.5 +/- 2.9 g/L, P < 0.01) and albumin mRNA expression. In patients with peritoneal sepsis, rhGH in combination with total parenteral nutrition markedly increased serum albumin, prealbumin, and transferrin concentration, but no apparent effect was observed in controls. CONCLUSION: rhGH significantly increases albumin mRNA expression and albumin synthesis in peritoneal sepsis.

Adult↗
PubMed1998

[Hypoxia impacts expression of nitric oxide synthase mRNA of different segments of intrapulmonary arteries].

OBJECTIVE: To investigate expression and localization of nitric oxide synthase (cNOS) mRNA of normoxic pulmonary arteries and the impact of hypoxia on its expression. METHODS: In situ hybridization was performed on each lung sections from rats in 1-week hypoxic group, 2-week hypoxic group, and control group to detect cNOS mRNA expression and localization by using cRNA probe for NOS. RESULTS: The positive score of cNOS mRNA expression by endothelial cells of pulmonary arteries associated with bronchioli was significantly higher than that of arteries associated with respiratory or terminal bronchioli (q = 8.13, 5.49, P < 0.01) in the control rats. In the 1-week hypoxic group or the 2-week hypoxic group, however, cNOS mRNA expression by endothelial cells of pulmonary arteries associated with either respiratory or terminal bronchioli was markedly decreased compared with that of the control group. No significant difference was found in cNOS mRNA expression by smooth muscle cells of each segments of pulmonary arteries (F = 2.26, P > 0.05). However, cNOS mRNA expression by smooth muscle cells of pulmonary arteries associated with respiratory bronchioli or terminal bronchioli was significantly decreased in the 1-week or the 2-week hypoxic group compared with the control group. CONCLUSION: These findings suggest that NOS mRNA expression by endothelial cells is greater in the larger, more proximal pulmonary arteries than at the periphery. Chronic hypoxia mainly impairs cNOS mRNA expression by proximal pulmonary artery endothelial cells and periphery pulmonary artery smooth muscle cells.

Animals↗
PubMed1998

[Esophageal carcinoma in part of population of Yangquan City].

OBJECTIVE: To evaluate the contribution of genetic factors to the occurrence of esophageal carcinoma (EC). METHODS: A genetic epidemiology survey of one-tenth of the whole population (130,000 people) was conducted in 6 towns of Yangquan City, Shanxi province in 1994. 228 high-risk (EC) families were matched with equal number of control families. RESULTS: The heritability of EC among first grade blood relatives was 52.6%, that among second grade blood relatives was 31.2%, and the summing up powered heritability was 49.2%. the segregation ratio was 18 +/- 3%, far less than 25%, suggesting a multi-gene effect. The distribution of EC in families did not fit well the binomial distribution, suggesting familial aggregation. The relative risk among male first grade blood relatives was 10.49, female was 7.69, in sum was 9.17. The attributive risks (AR) among first grade blood relatives were 62.13/100,000(male), 99.14/100,000(female) and 75.15/100,000(total). All of these figures were higher than the average (40.17/100,000). CONCLUSION: Genetic factors plays important roles in occurrence of EC in the Taihang mountain region.

Aged↗
PubMed1998

[The deletion of AT2 receptor gene antagonizes angiotensin II-induced apoptosis in fibroblasts].

OBJECTIVE: To study the expression of angiotensin II (Ang II) type 2 receptor (AT2) and its effect on the Ang II-induced apoptosis in fibroblasts. METHODS: Skin fibroblasts were cultured from the embryos of the AT2 receptor gene deleted (AT2-/-) and wild-type (AT+/+) mice at 16 days of gestation. After Ang II being stimulated, the expressions of AT1 and AT2 receptor genes were examined by RT-PCR and the apoptotic changes were identified by genomic DNA electrophoresis, TUNEL staining and flow cytometry analysis of DNA contents. And they were compared in these two types of cultured fibroblasts. RESULTS: Treated with Ang II for 48 h at the concentrations of 10(-8), 10(-7), 10(-6) and 10(-5) mol/L respectively, the expressions of AT1 and AT2 receptor genes were enhanced in a dose-dependent manner. Induced by Ang II for 72 h at the concentrations of 10(-6) and 10(-5) mol/L, genomic DNA fragmentation, one of convinced markers of cell apoptosis was found in the AT2+/+ fibroblasts, but not in the AT2-/- fibroblasts. The percentages of Ang-induced apoptosis of the AT2+/+ fibroblasts were (12.3 +/- 2.7)% (10(-6) mol/L) and (21.7 +/- 6.7)% (10(-5) mol/L) respectively. CONCLUSION: The Ang II-induced apoptosis of fibroblasts was devoid after deletion of AT2 receptor gene.

Angiotensin II↗
PubMed1998

[Angiotensin II type 2 receptor inhibits type 1 receptor-induced cell proliferation and fibronectin release in mouse fibroblasts].

OBJECTIVE: To investigate the effects of angiotensin II type 2 receptor (AT2) on the cell proliferation and fibronectin release induced by angiotensin II type 1 receptor (AT1). METHOD: Fibroblats were cultured from embryonic skin of AT2 receptor gene knocked-out mice (AT2-/-) and wild-type mice (AT2+/+) after 16 days of gestation, respectively. Cell proliferation and fibronectin release were examined in the fibroblasts treated with 10(-8) mol/L angiotensin II. RESULTS: Cell proliferation rate was increased more markedly in the AT2-/- fibroblasts than in the AT2+/+ fibroblasts after treament with angiotensin II (0.462 +/- 0.026 VS 0.389 +/- 0.021, P < 0.01). Also, fibronectin release and its gene expression were significantly enhanced in the AT2-/- fibroblasts as compared with the AT2+/+ fibroblasts when exposed to angiotensin II (34.1 +/- 4.1)% vs (16.2 +/- 2.3)%, P < 0.01). CONCLUSION: The AT2 receptor can inhibit the cell proliferation and fibronectin release induced by the AT1 receptor.

Angiotensin II↗
PubMed1998

[The study on the anti-tumor function of lysozyme in the regional lymph nodes of laryngocarcinoma patients].

The purpose of this study was to discuss the anti-tumor function of lysozyme (LZM) to laryngocarcinoma. The LZM distribution of regional lymph nodes incised from laryngocarcinoma patients in paraffin sections was observed by immunohistochemical technique. By the cell culture technique, autologus laryngocarcinoma cells were used as target cells to evaluate the tumoridical activity of MØ which were isolated from the regional lymph nodes of laryngocarcinoma patients. At the same time, ConA was added as control group. The supernatant of cell culture was collected after 24 hours to detect LZM content. The results indicated that the number of LPM in non-metastatic lymph nodes was significantly more than in metastatic lymph nodes (P < 0.01). The MØ isolated from patients' regional lymph nodes released LZM content and it's tumoridical activity to autologus tumor cells were significantly increased after adding ConA (P < 0.01). The LZM releasing content and tumoridical activity of MØ in non-metastatic lymph nodes were much more than metastatic lymph nodes (P < 0.05). The LZM content and tumoridical activity of MØ were analyzed with linearity relapsing statistics, it was positive linearity relation (r = 0.94, P < 0.01). All above suggests that the LZM of laryngocarcinoma patients is closely related to the anti-tumor function, it improves the tumoridical activity of MØ to autologus laryngocarcinoma cells and accelerates the death of laryngocarcinoma cells.

Adult↗
PubMed1998

[Comparison of pharmacological effects between cultispecies Sichuan Fritillary bulb (F. wabueasis, F. mellea) and wild Sichuan Fritillary bulb (F. unibracteata)].

The ethanol extracts from the cultured Sichuan Fritillary bulb have been proved similar to those from the wild one in treating coughing in mice, expectoration in rats, asthma in guinea pigs, bronchodilation of isolated lungs in mice, and cyclic nucleotide(cAMP, cGMP) in the plasma and lungs of mice. The acute toxicity of the cultured and wild species is also similar to each other. However, in terms of asthma relieving and cAMP level increment in the lungs, the cultured species F. wabueasis is significantly superior to the wild species of Fritillary bulb.

Animals↗
PubMed1998

[Ultrastructural morphometric studies of fat storing cells in human chronic viral hepatitis].

OBJECTIVE: To study the dynamic changes of fat storing cells (FSC) in human chronic viral hepatitis. METHODS: Liver biopsies from 5 chronic persistent hepatitis (CPH), 5 mild chronic active hepatitis (CAH), 6 moderate CAH, 5 severe CAH cases and 8 normal liver tissues were used to investigate the number, appearance and organellae of FSC in non-fibrotic areas by cell counting under light microscope with semi-thick sections and morphometric study under electron microscope. RESULTS: The number of FSC in non-fibrotic areas of CAH groups were decreased significantly compared with the normal group and CPH group; the percentages of transitional cells tended to increase along with the increase in degree of severity of liver fibrosis, some of the FSC were transformed into fibroblasts. CONCLUSIONS: During the progress of liver fibrosis caused by CAH, FSC were constantly transformed into fibroblasts which tended to migrate to the fibrous septum of the hepatic lobules.

Electronic Data Processing↗
PubMed1998

Long-term studies on allotransplantation of rabbit retinal pigment epithelial cells double-labelled with 5-bromodeoxyuridine and natural pigment.

OBJECTIVE: To facilitate the identification of transplanted retinal pigment epithelial (RPE) cells, we sought to double-label the cells with 5-bromodeoxyuridine (BrdU) and with natural pigment. The BrdU is not lost during cell division but does require immunohistochemical methods for visualization; the pigment on the other hand, allows immediate, obvious identification, but is gradually lost with cell division. Together they provide a convenient, long-term double label. METHODS: Non-confluent RPE cells at the second to the fifth passages were labelled with 5-BrdU and pigment. The double-labelled RPE cells were transplanted onto Bruch's membrane of 72 eyes of New Zealand albino rabbits. The labelled cells were localized by anti-BrdU antibody and the avidin biotin-alkaline phosphatase complex (ABC-AP) method, and by visible inclusions of pigment. RESULTS: The transplanted RPE cells had distinct basal and apical morphology, and were in close contact with the photoreceptor outer segments of the host. The BrdU label was restricted to the nuclei of the RPE cells, which were stained blue. The pigment was located in the cytoplasm of the apical portion of these RPE cells. No evidence of severe rejection was seen. CONCLUSIONS: Using this double-label method, transplanted RPE cells could be readily and reliably identified till one year after transplantation. The transplanted RPE cells revealed normal morphology with some function: they had distinct basal and apical morphology as seen in close contact with the outer segment of photoreceptor cells. The junctional complexes were well formed with neighboring RPE cells. The transplanted RPE cells phagocytose shed outer segments of the host. No evidence of rejection was observed, suggesting that the subretinal space of the rabbit may possess some degree of immunologic privilege. This experiment provides reliable evidence for the clinical research of allotransplantation of RPE cells.

Affinity Labels↗
PubMed1998

[Histopathological study of surgical resection margins of laryngeal carcinoma].

64 specimens of laryngeal carcinoma were studied by using the step-serial whole organ section and histopathologic examination of the region around tumor. We discussed the situation of lesions spreading from tumor to resection margins, the survival rate of different types of resection margins, the common position of positive resection margins and the correlative factors of positive resection margins combining with histopathology, clinical expression and follow-up results. We concluded that resection margins more than 5 mm far from visible tumor is suitable.

Adult↗
PubMed1998

[The expression of CD44, PCNA, vWF: Ag in non-Hodgkin's lymphoma and its relationship with the grade of malignancy].

OBJECTIVE: To study the expression of CD44, proliferating cell nuclear antigen (PCNA), vWF: Ag in normal lymphatic tissue and non-Hodgkin's lymphoma (NHL) and its implication. METHODS: Immunohistochemical assay was performed with a LSAB kit. RESULTS: 1. In normal lymphatic tissues, mature appearing small lymphocytes were positive for CD44, while proliferating immature lymphocytes in germinal center were negative. 2. High grade and intermediate grade NHL samples were strongly positive for CD44, the positive rate in the former was higher than in the latter (P < 0.05). In the ten low grade lymphoma samples, only two were weakly positive and, the rest were negative. The expression of PCNA showed the same manner as CD44. 3. The microvessels in NHL increased with the histological malignant grade. CONCLUSION: The expression of CD44 in normal lymphatic tissues is different from that in NHL. Combination of CD44 expression with PCNA expression and microvessel density seems a reliable parameter for judging malignant degree of NHL.

Humans↗
PubMed1998

[Study on delayed rectifier K+ current of rabbit vascular smooth muscle cells and comparison with cloned Kv1.5 channel].

Whole cell patch-clamp recording techniques were used to compare the electrophysiological properties between delayed rectifier K+ current of rabbit vascular smooth muscle cell (VSMC) and the cloned Kv1.5 channel. When VSMC is clamped at -40 mV, depolarizing the membrane potential at increasing steps of 10 mV could evoke a series of outward potassium currents without any deactivation. The V1/2 of the activation curve was 27.2 mV. The currents decrease obviously after adding 100 mmol/L TEA or 1 mmol/L 4AP in the perfusate. When the concentration of extracellular Ca2+ was decreased from 1.5 mmol/L to 0.5 or 0 mmol/L, the currents did not show much change, while in HBK7 (cloned Kv1.5 channel cell) held at -80 mV, similar steparise depolarization could also produce a series of outward potassium currents without any deactivation decayed. V1/2 of the activation was 0.8 mV. 4AP inhibited the cloned channel current with IC50 of 7.3 mmol/L, showing neither frequency- or use-dependence. TEA (30, 100 and 300 mmol/L) reduced the current by 28.6%, 37.4% and 46.3% respectively. Quinidine (0.1 and 1 mmol/L) decreased it by 29.7% and 37.4%. These results show what we have recorded in isolated rabbit vascular smooth muscle cells is the delayed rectifier potassium currents which are different in electrophysiological and pharmacological properties from those of cloned Kv1.5 channel current.

Animals↗
PubMed1998

[Ultrasound bone measurement of the tibia: comparison with vertebral dual-energy X-ray absorptiometry and appendicular single photon absorptiometry].

OBJECTIVE: Ultrasonic techniques have been used to assess the mechanical properties of bone. Recently, a new ultrasonic bone instrument, which measured the SOS (speed of sound) at the tibial shaft, has been introduced (Sound Scan 2000, Myriad Ultrasound Systems Ltd.). The aim of this work was to investigate the correlation of tibial SOS with bone mineral density (BMD). METHODS: The tibial SOS was measured in 213 healthy women (aged 22-83 years) and 56 female primary osteoporosis with vertebral fractures (aged 53-82 years). Values of SOS were compared with BMD assessed by dual energy x-ray absorptiometry (DEXA) at spine and hip sites and single photon absorptiometry (SPA) at the distal forearm. RESULTS: Tibial SOS correlated more closely with the BMD of lumbar, hip and forearm (r = 0.387-0.928, P < 0.001). The tibia SOS values and the BMD values measured by the DEXA and SPA were negatively correlated to age and years since menopause. In particular, they were obviously lower in the group of 50 years old. The tibial SOS of vertebral fracture group was significantly lower than that of well-matched non-fracture-group (n = 104, aged 51-84 years). CONCLUSIONS: Tibial SOS was significantly correlated with BMD measured by DEXA or SPA respectively and able to discriminate patients with vertebral fracture from the age-matched controls.

Absorptiometry, Photon↗
PubMed1998

[Preoperative nasal continuous positive airway pressure treatment as substitute for protective tracheostomy in severe obstructive sleep apnea syndrome].

OBJECTIVE: Preoperative nasal continuous positive airway pressure(NCPAP) treatment was used as a substitute for protective tracheostomy before UPPP surgery in 42 patients with severe obstructive sleep apnea syndrome(OSAS) from 1994 to 1996. METHODS: Fifty-two patients operated on three years before this period served as control group. All cases were diagnosed as severe OSAS by polysomnography (PSC). RESULTS: There were no statistical difference in main parameters between two groups. Seven cases in the control group underwent protective tracheostomy whose apnea and hypopnea index(AHI) was 28.4-83.5 and lowest saturation oxygen (SaO2) were 7%-32%. One patient underwent emergency tracheostomy due to life-threatening situation during uvulopalatopharyngoplasty (UPPP). There were 9 similarly severe cases who did not undergo protective tracheostomy in NCPAP treatment group. All patients underwent preoperative 5-20 day NCPAP treatment in treatment group. The average positive pressure was 1.16 kPa(11.85 cmH2O). There were significant difference in main parameters between the two groups. The AHI, SaO2 and sleep structure were evidently improved. UPPP was safely performed without protective tracheostomy and any complications in all patients with NCPAP treatment. CONCLUSION: This result implys that NCPAP treatment could be used as a substitute for protective tracheostomy before UPPP in severe OSAS.

Adolescent↗
PubMed1998

[Selection of key biological components (KBC) for Controlled Ecological Life Support System (CELSS)].

Biological components are key parts in Controlled Ecological Life Support System (CELSS), the future experimental success will depend to a large extent on the suitability of selected KBCs. For this purpose, 15 KBCs including 4 higher plants(vegetables), 5 microorganisms, 5 microalgae and 1 lower plant were selected from lots of biological species for CELSS. These results laid a solid foundation for our studies of CELSS.

Ecological Systems, Closed↗
PubMed1998

[Effect of xueling on relating substances of renal hypertension in rats].

Xueling(p.o.) obviously reduces the aldosterone content of renal hypertension rats, but not affecting markedly the endothelin, atrial natriuretic factor, calcitonin gene-related peptide, thromboxane B2 and 6-keto-prostaglandin F1 alpha. The content reduction of aldosterone is one of the mechanisms to lower blood pressure.

6-Ketoprostaglandin F1 alpha↗