Biomedical subjects

Y Yang

Publications and source records attributed to Y Yang.

At least 505 records · Page 28Linked to original sources

PubMed2000

[The effect of splenectomy on circulating endotoxin clearance and tissue distribution of endotoxin in rats].

OBJECTIVE: To study the effect of splenectomy on circulating endotoxin clearance and tissue distribution of endotoxin, and investigate the potential mechanism(s) underlying inflammatory response and multiple organ damage following splenectomy. METHODS: 112 male Wistar rats were randomly divided into two groups: control group (n = 56, included omentectomy and mobilization of the spleen), and splenectomy group (n = 56). The latter was further sub divided into 10-min, 0.5-, 1.5-, 4-, 12-, 24-hour groups after endotoxin challenge. Tissue and systemic blood endotoxin concentrations were measured using the chromogenic limulus amebocyte lysate (LAL), which was modified by perchloric acid (PCA) pretreatment for samples. Liver function parameter and lung tissue myeloperoxidase (MPO) were also measured. RESULTS: After endotoxin administration, plasma endotoxin concentrations were higher in splenectomized rats than in controls at 10 minutes and 0.5 hour (P < 0.01). Endotoxin clearance was delayed in liver and lung in animals after splenectomy. MPO values of the control group were significantly higher than those of splenectomy groups (P < 0.01). CONCLUSION: Splenectomy can lead to impairment of intravascular clearance of endotoxin and endotoxin accumulation in liver and lung. Endotoxin accumulated in local sites may be involved in the development of inflammatory response and multiple organ dysfunction following splenectomy.

Animals↗

PubMed2000

[Resection of pelvic retroperitoneal neoplasm and reconstruction of iliac blood vessels: report of 22 cases].

OBJECTIVE: To study the surgical manipulation of iliac blood vessels invaded by pelvic tumors in order to raise the resection rate. METHODS: We reviewed 22 cases of resection for pelvic retroperitoneal tumors along with the reconstruction of iliac blood vessels in our hospital from July 1994 to January 2000. In 22 cases, 8 received operation on the right iliac arteries and veins, and 14 on the left. RESULTS: Follow-up for 4 months to 5 years and 10 months (average 3.6 years) showed that 3 patients had recurrence and needed secondary operation. All the grafts were patent except one vein graft occlusion 7 months after operation. CONCLUSION: Resection of pelvic retroperitoneal neoplasm combined with reconstruction of iliac blood vessels is safe, effective and practical to raise the excision rate and decrease the recurrence rate.

Adult↗

PubMed2000

[The age-related effect of basic fibroblast growth factor on the proliferation of lens epithelial cells].

OBJECTIVE: To detect the age-related effect of basic fibroblast growth factor (bFGF) on the proliferation of human lens epithelial cells (HLECs) in patients with cataract and discuss the mechanism. METHODS: Human lens anterior capsules with attached HLECs were cultured in vitro, treated with 10 microg/L bFGF for 48hr, and then the positive area ratio of proliferating cell nuclear antigen (PCNA) in immunohistochemistry was estimated. Immunohistochemical analysis of bFGF receptor was also carried out. RESULTS: The bFGF could enhance the HLEC proliferation in patients with cataract at various ages. The enhancement of the proliferation and the expression of bFGF receptor protein were negatively correlated to the age of the patients with cataract (P < 0.01). CONCLUSIONS: The basic fibroblast growth factor might play an important role in the formation of posterior capsular opacity (PCO) after cataract surgery. With the decrease in the patient's age, the enhancement of HLEC proliferation is increased, indicating that the fact is related to the high incidence of PCO in children.

Adolescent↗

PubMed2000

[Subcutaneous panniculitis-like T-cell lymphoma: expression of cytotoxic-granule-associated protein TIA-1 and its relation with Epstein-Barr virus infection].

OBJECTIVE: To study the clinicopathologic features, the expression of cytotoxic-granule-associated protein TIA-1 and Epstein-Barr virus (EBV) infection in subcutaneous panniculitis-like T-cell lymphoma (SPTCL). METHODS: Totally 17 cases of SPTCL were studied. Immunohistochemical staining was done for TIA-1, CD45RO, CD3, CD20 and CD68, and in situ hybridization for EBV encoded small nuclear RNA (EBER1/2). RESULTS: In the 17 cases of SPTCL, the ratio of male-to-female was 1:1.1 and the median age was 24 years old. The main clinical manifestations were asymptomatic plaques, nodules and masses. Histologically, the pattern of lymphoid cells infiltration was panniculitis. The infiltrated lymphoid cells were pleomorphic and their mitotic figures were few (0 - 2/hpt). In the tumor tissue, there might be epithilioid granulomas, multinuclear cells, beanbag cells, small pieces of necrosis and small vessels with lymphoid cells infiltration in the vascular wall. Immunohistochemically, all the cases showed a T-cell phenotype and the expression rate of TIA-1 was 100% (16/16). By in situ hybridization, the positive rate of EBV-EBER1/2 was 29.4% (5/17). CONCLUSIONS: SPTCL has a specific histopathologic picture. It may originate from cytotoxic T lymphocytes or NK cells. Some of them may be accompanying with EBV latent infection.

Adolescent↗

PubMed2000

[Increased expression of peritoneal macrophage CD14 in severely burned mice].

OBJECTIVE: To observe the dynamic changes in peritoneal macrophage (Mphi) CD14 expression in severely burned mice. METHODS: The mice, being inflicted with 20% TBSA III degree burn, were randomly divided into two groups: Group A: The mice in this group received fluid resuscitation instantaneously after burn. Group B: The mice in this group received delayed fluid resuscitation at 6hr postburn. The Mphis at different postburn time points were obtained in two groups for the detection of their expression of CD14 and CD14 mRNA with immunohistochemical and RT -- PCR analysis, and also for the determination with ELISA of the changes in TNF and IL -- 6 levels in the supernatant of their culture. RESULTS: The expression of CD14 and the levels of TNF and IL -- 6 increased obviously in both groups from 1 to 24 hrs postburn. CONCLUSION: Burn injury would induce the increase of the expression of Mphi CD14 mRNA in mice. As a result, the Mphi became more readily to be activated by low levels of LPS. The activated Mphi might play an important role in the development of postburn SIRS.

Animals↗

PubMed2000

[The expressions of transcription factor c-fos mRNA and its protein in the burn wound of rats].

OBJECTIVE: To investigate the rule of the expression in different time points of wound tissue transcription factor c-fos mRNA and its protein after burn, so as to explore the role of c-fos in the initiation of burn wound injury and repairing. METHODS: Male Wistar rats were inflicted with partial thickness scalding of 30% TBSA on the back. In situ hybridization and immunohistochemical methods were used to evaluate the characteristics and pattern of the changes in the expressions of the c-fos mRNA and its protein in normal skin and in the wounded skin at 3 h, 6 h, 1 d, 3 d, 7 d and 14 d postburn, respectively. RESULTS: It was found by light microscopy (LM) that c-fos mRNA and its protein could be found expressed in normal skin and obviously increasingly expressed in wounded skin. The expression of fos protein reached peak level at 3 postburn hour (PBH) and that of its mRNA at 6 PBH. CONCLUSION: The expression of c-fos mRNA and its protein could be induced during burn injury. But the postburn increase in the expression of its gene appeared later than that of its protein, suggesting that the early-appeared fos protein acted through its post-translational modification of preexisting fos molecule.

Animals↗

PubMed2000

[Acute promyelocytic leukemia cell differentiation induced by tanshinone II A and its molecular mechanism].

OBJECTIVE: To investigate APL cell differentiation induced by tanshinone II (Tan II A) and its molecular mechanism. METHODS: In vitro incubation of NB4 cells with Tan II A at the concentration of 0.5 microg/ml for 5 days, the cell differentiation was observed by cytomorphology, and nitroblue tetrazolium (NBT) test. Cell cycle, membrane CD(33), CD(11b) antigens and gene expressions (c-myc, c-fos, p53 and bcl-2) were analysed by flow cytometry. RESULTS: (91.3 +/- 2.1)% of NB4 cells were induced into morphologically and functionally more differentiated cells including 0.26 of myelocytes and metamyelocytes, and 0.68 of band form and neutrophils. Cell growth curve showed that growth of NB4 cells were inhibited. NBT reduction was significantly increased. Expression of CD(33) decreased and CD(11b) increased. The degrees of cell differentiation and growth inhibition induced by Tan II A or ATRA were no difference. Flow cytometry analysis showed that Tan II A arrested NB4 cell in G(0)/G(1) phase, inhibited cellular DNA synthesis, down-regulated c-myc and bcl-2 genes expression, and up-regulated c-fos and p53 genes expression. CONCLUSION: Tan II A can induce differentiation and growth inhibition of NB4 cells. Its possible molecular mechanism might relate to modulation of gene expressions associated proliferation and differentiation, and to inhibition of DNA synthesis.

Abietanes↗

PubMed2000

[Influence of pravastatin on expression of platelet CD(62P) and CD(41) in patients with hypercholesterolemia in vitro and in vivo].

OBJECTIVE: To study in vitro and in vivo effect of hypercholesterolemia (HC) on expression of platelet CD(62P) and CD(41) and their changes after treatment with pravastatin. METHODS: Twenty patients with HC were given 10 - 20 mg/d pravastatin orally for 4 - 8 weeks. Changes of blood cholesterol and expression of platelet CD(62P) and CD(41) were detected by flow cytometry. RESULTS: After 4 and 8 weeks' treatment, blood cholesterol level and platelet aggregation function decreased. The expression of CD(62P) average fluorescence intensity decreased from 31.8 +/- 7.8 to 27.2 +/- 6.9 and 26.8 +/- 4.9; CD(62P) (%) from (31.3 +/- 9.3)% to (26.4 +/- 7.4)% and (25.3 +/- 9.1)% (P < 0.05); CD(41) from 483.2 +/- 263.9 to 348.1 +/- 192.4 and 306.8 +/- 128.0 (P < 0.05), respectively. Similar results were obtained in vitro study. CONCLUSION: Improvement of platelet function and expressions of CD(62P) and CD(41) in HC patients after prevastatin treatment may be resulted from enhancing arteriosclerosis regression. It suggested from the in vitro result that pravastatin might play a direct effect on platelet function.

Adult↗

PubMed2000

[Studies on the effect-increasing components for molluscacides in nut of Areca catech L].

OBJECTIVE: To investigate the effect-increasing action of Areca catech for molluscacide. METHOD: Experiments were conducted on the effect-increasing components isolated from the dry nut of A. catech. RESULT: Arecoline has been proved the most effect-increasing component. CONCLUSION: When used with SPA arecoline could reduce markedly the doses of the two agents.

Animals↗

PubMed2000

[Study on sensitivity of neuroglioma to chemotherapeutic drugs].

In this study, the chemosensitivity of 36 cases' fresh neuroglioma specimens was examined in vitro with MTT assay. The separation method for single tumor cell, the number of planting of cells, and the dosage and acting time of drugs, which have effects on the results of MTT assay, were studied systematically. On the basis of this experiment, we established a screening method for the chemosensitivity of neuroglioma; it is accurate, rapid, and simple. At the same time, the results showed that neuroglioma was more sensitive to the chemotherapeutic drugs Vm26, DDP and MMC, and the sensitivity varied with not only the drugs but also the individuals.

Antineoplastic Agents↗

PubMed2000

[Terminal differentiation of human acute promyelocytic leukemia (APL) cells induced by Tanshinone II A in primary culture].

The aim of this study was to investigate whether Tanshinone II A (Tan II A) can induce human acute promyelocytic leukemia (APL) cells to differentiate or not in primary culture. The APL cells from 5 cases were cultured respectively with Tan II A at the concentration of 0.5 microgram/ml for 7 days in vitro. The differentiations of these leukemia cells were observed cytomorphologically and examined by nitroblue tetrazolium (NBT) test. The cell DNA cycle and membrane cluster differentiation (CD) antigens (CD33, CD11b) were analyzed by flow cytometry. The results showed that 82.5% +/- 4.8% of APL cells were induced into morphologically and functionally differentiated cells. The cell growth curve showed that the growth of APL cells was inhibited. The degree of differentiation and growth inhibition induced by Tan II A was not different from that by ATRA (P > 0.05). Flow cytometry analysis showed that Tan II A arrested APL cells in G0/G1 phase and inhibited cellular DNA synthesis. This study demonstrates that Tan II A can induce differentiation of APL cells in vitro, and hence it is worthy of further studies for clinical use.

Abietanes↗

PubMed2000

[Effect of electroacupuncture on mRNA expression of NGF and IGF-1 in injured nerve].

OBJECTIVE: To investigate the effect of electroacupuncture on mRNA expression of NGF and IGF-1 in injured nerve. METHODS: Sciatic nerve injury model was established by transection of right side sciatic nerve in 90 male SD rats, which were randomly divided into two groups. The experimental group was treated with electroacupuncture, no treatment in the control group. The distal part of the injured nerve was harvested after 1, 2, 4, 6 and 10 weeks of operation and stored in the liquid nitrogen. The total RNA was extracted by the TRIzol reagent. Reverse transcriptase-polymerase chain reaction(RT-PCR) was used to detected the mRNA expression of NGF and IGF-1. RESULTS: The mRNA expression of NGF in the experimental group was increased quickly from the second week, and reached to highest level in the fourth week. It was much higher than that of the control group (P < 0.05). Then it began to decline in following time and approximately reached to the level of the first week after 10 weeks of operation. The mRNA expression of IGF-1 in the experimental group was remarkably increased in the second and fourth week, and which was much higher than that of the control group respectively(P < 0.05). Although the mRNA expression of IGF-1 after 10 weeks of operation in the experimental group was higher than that of the control group, but there was no significant difference between the two groups(P > 0.05). There was linear correlation in the fourth week between mRNA expression of NGF and IGF-1 in the experimental group. CONCLUSION: The mRNA expression of NGF and IGF-1 can be elevated in injured nerve at early stage interfered with electroacupuncture.

Animals↗

PubMed2000

[Effects of deoxynivalenol on proliferation and tumor necrosis factor-alpha secretion of human peripheral blood mononuclear cells in vitro].

Deoxynivalenol (DON) is one of the most common contaminating mycotoxins in food at high risk areas of esophageal carcinoma in China. The effects of DON on proliferation and tumor necrosis factor-alpha (TNF-alpha) secretion of human peripheral blood mononuclear (HPBM) cells in vitro were determined with flow cytometric (FCM) analysis, cell counting, MTT bioassay and ELISA method respectively. FCM analysis revealed that after HPBM were prestimulated with PHA for 48 h, the proliferation indexes(PI) of the cells treated with low concentration of DON (50-500 ng/ml) for 6 h were all dramatically lower than that of normal control (19.80%-26.01% vs 37.84%), while the PI of cells treated with high concentration of DON(1000-2000 ng/ml) for 24 h were higher than that of normal control (35.74%-34.37% vs 22.85%). Cell number counting and MTT bioassay results showed that at the presence of PHA, DON inhibited the proliferation of HPBM. Double antibody sandwich enzyme linked immunosorbent assay (ELISA) showed that the secretion of TNF-alpha in cells treated with DON(500-1000 ng/ml) was significantly lower than that in the control (P < 0.01). The results suggested that DON could either inhibit or stimulate cell proliferation depending on active time, concentration and PHA stimulation. In general, DON mainly inhibited the proliferation of HPBM and decrease TNF-alpha secretion in vitro. Thus, DON might have some negative impacts on human immunological system.

Cell Division↗

PubMed2000

[Determination of trace elements in serum of tuberculosis patients].

In order to investigate the changes of molybdenum (Mo), zinc (Zn), copper (Cu), manganese (Mn) and seleniumin (Se) level in serum of tuberculosis patients, the concentrations of Mo, Zn, Cu, Mn and Zn in serum of 30 tuberculosis patients and 30 health controls were determined by inductively coupled plasma mass spetrometry. The results showed that compared with the control group, the levels of Mo, Zn, Cu, and Se in the serum of tuberculosis patients decreased significantly (P < 0.001), but the change of Mn was insignificant (P > 0.05).

Adolescent↗

PubMed2000

[Optimal treatment parameters for damage of chicken comb vessels using chlorophyll derivative IV in photodynamic therapy].

OBJECTIVE: To define the optimal treatment parameters of chlorophyll derivative IV (CPD4) in photodynamic therapy(PDT) of port wine stains(PWS) by observing the morphological changes of chicken combs. METHODS: 102 animals were divided into 6 groups at random, including 3 control groups(given no treatment, given light without photosensitizer or given photosensitizer without light) and 3 experimental groups treated with different CPD4 dosages(5, 7.5, 10, 12.5, 15 mg/kg body weight), power density(50, 100, 150, 200 mW/cm2), energy density (15, 30, 45, 60, 120, 135, 180 J/cm2) and different intervals between CPD4 injection and irradiation (immediately, 5, 10, 20, 30, 60, 120, 180, 240 minutes). The main emitting peak of light source was at 650 nm, and CPD4 was injected intravenously, then the appearance of chicken comb was recorded everyday. The prepared sections were stained with HE. The histological changes of chicken comb were observed by light microscope. RESULTS: The control animals showed no significant comb changes, while the PDT could cause blanching of the chicken comb in the experimental group. The histologic changes included damage of erythrocytes and endothelial cells, vascular rupture, hemorrhage or disappearance, denaturation of perivascular collagen fiber and local necrosis of chicken combs. The treatment parameters which caused the most obvious blanching of the chicken comb were 7.5-10 mg/kg body weight of CPD4 dosage, 100-150 mW/cm2 of power density, 60-90 J/cm2 of energy density, and the intervals between CPD4 injection and irradiation were 0-20 minutes. CONCLUSION: CPD4 in PDT can cause selective damage of dermal capillaries in chicken comb and blanching of the chicken comb with optimal treatment parameters. The results will offer the basis for further investigation of clinic treatment parameters.

Animals↗

PubMed2000

[A clinical study on PA-MSHA vaccine used for adjuvant therapy of lymphoma and lung cancer].

The objective of this study was to evaluate the effectiveness and safety of pseudomonas aeruginosa MSHA vaccine (PA-MSHA vaccine) used as an immune modulator. The study was carried out after the design of a non-blind, randomized controlled trial. The malignant lymphoma patients were divided into experiment group (45 cases) and control group (43 cases). Likewise were distributed the lung cancer patients: 44 cases in experiment group and 45 cases in control group. The two experiment groups received chemotherapy + PA-MSHA vaccine. The two control groups were given chemotherapy alone. The results showed that the clinical efficacy rate was 95.56% for the exp. group and 69.77% (P < 0.01) for the control group of the malignant lymphoma cases; the clinical efficacy rate was 59.09% for the exp. group and 42.22% (P < 0.01) for the control group of the lung cancer cases. The infection rate was 17.78% for the exp. group and 37.21% (P < 0.05) for the control group of the malignant lymphoma cases; the infection rate was 15.91% for the exp. group and 40.00% (P < 0.05) for the control group of the lung cancer cases. The comprehensive immune effectiveness rates for the exp. group and control group of the malignant lymphoma cases were 77.78% and 23.26% (P < 0.01) respectively. The comprehensive immune effectiveness rates for the exp. group and control group of the lung cancer cases were 84.09% and 35.56% (P < 0.01) respectively. Adverse reactions were found in 5 cases, of which, one was given medical care while the others automatically recovered. These results indicate that PA-MSHA vaccine, as a new kind of immune modulator, can improve the effectiveness of treatment for tumor with low adverse reaction rate.

Adjuvants, Immunologic↗

PubMed2000

[Study on chemosensitivity assay in vitro in the peripheral blood lymphocyte and the tumor cells].

In this study, the MTT method was used to test the sensitivity of the peripheral blood lymphocyte and the tumor cells of 35 patients with neuroglioma to 15 kinds of anti-cancer drugs. The results showed that the peripheral blood lymphocyte and the tumor cells were more sensitive to chemotherapeutic drugs Vm26 and TAX, and sensitive to DDP, Me-CCNU, EADM, ADM, MMC, HCPT, but not sensitive to MTX, ACR, VP-16, VCR and BLM. There were no statistical differences in the rate of sensitivity to the above-mentioned drugs between the peripheral blood lymphocyte and the tumor cells. These results prompt that the chemosensitivity test of the peripheral blood lymphocyte may take the place of the tumor cells for reference to choosing chemotherapeutic drugs in clinical practice.

Antineoplastic Agents↗

PubMed2000

[Effect of vasostomy on expression of Bcl-2 and Bax gene in rat spermatogenic cells].

The objective of this study was to explore the change of Bcl-2 and Bax gene expression in rat spermatogneic cells after vasostomy. A rat model with vasoligation and vasostomy was set up and then used for detecting the protein expression of Bcl-2 and Bax gene at 4, 8, 12, 16 weeks after vasostomy by means of immunohistochemistry. Sixty rats were randomly distributed into three groups named vasoligation group (VG), vasostomy group(VOG) and sham-operation group(SOG) respectively. The results showed that the Bcl-2 protein expression in VOG group increased gradually and came to be significantly higher than that in VG group 8 weeks after vasostomy, and it's level was the same as that in SOG group at the 12th week. The bax protein expressions in VG and VOG groups were significantly higher than that in SOG group, but there was no difference between VOG and VG groups. In conclusion, the change of Bcl-2 protein expression observed in this study is indicative of the anti-apoptosis function of Bcl-2 gene in both the status of being vasoligated and vasostomized, whereas the consistent Bax protein expression before and often the repatency of the vas suggests further researches into its effect on apoptosis of spermatogenic cells.

Animals↗