Search PubMed⌕ Search

Biomedical subjects

H Liu

Publications and source records attributed to H Liu.

At least 631 records · Page 35Linked to original sources
PubMed1999

Studies on renin-2 gene in transgenic rats.

OBJECTIVE: To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. METHODS: A renin-2 gene restriction map was constructed by endonuclease digestion and Southern blotting hybridization. Transgenic rats were produced via microinjection method. RESULTS: The 24 kb fragments containing mouse full-length ren-2 and its flanking sequence were cleaved by single enzymes (EcoR I, Kpn I and BamH I) and combined enzymes (EcoR I/Kpn I, Kpn I/BamH I and BamH I/EcoR I), respectively. The digests were electrophoresed in 0.8% agarose plates and transferred onto NC membranes. Radioactive 735 bp and 1400 bp probes obtained from half and full-length renin-1 cDNA were used in southern blotting hybridization. According to the electrophoresis and hybridization patterns, a ren-2 restriction map was constructed. 1603 fertilized rat ova after injection with purified 24 kb renin-2 gene were implanted into the oviducts of 81 pseudopregnant recipients in about 20 ova per female rat. 306 progenies were obtained from 50 foster mothers (average of pregnancies was 56.6%). 248 survived pups were identified by PCR analysis and Southern hybridization, and eight positive rats were found to be the transgenic rats (founder, F). All of them carried long fragments (24 kb) of renin-2 gene with normal blood pressure. Preliminary breeding and screening were carried out in the founder. Total survival pups (17.8%) and overall efficiencies (1%) were harvested as the same as those reported in the literatures. A systemic observation and the problems occurred during production of transgenic rats were also described besides the technique procedure used in this study. CONCLUSIONS: Mapping of full-length murine ren-2 can be used in investigation of the structure and function of the gene. The results denoted that the ren-2 transgenic rats were successfully established in this study and the technique used in the production of transgenic rats was proved to be valid in leading to wide-spread application of transgenic technique to many other related researches.

Animals↗
PubMed1999

Aldosterone biosynthesis in extraadrenal tissues.

OBJECTIVE: To determine whether extraadrenal tissues synthesize aldosterone in addition to vascular tissue and brain. METHODS: Ex vivo kidney perfusion was performed in normal Wistar rats, ACEI pretreated and adrenalectomized rats prior to the perfusion experiment. After equilibration for 30 minutes, 120 ml of perfusate was collected and subjected to reverse-phase HPLC and then aldosterone was measured by RIA. By RT-PCR and Southern blot the expression of aldosterone synthase gene-CYP11B2 mRNA was studied in both kidney tissue and cultured renal tubular epithelial cell, lung and liver tissues. In situ hybridization was used to identify the cell types of liver and lung expressing CYP11B2 mRNA. RESULTS: Production of aldosterone in the kidney perfusate was not changed in adrenalectomized rats although it was decreased in the group pretreated with ACEI perindopril. By RT-PCR and Southern blot the expression of CYP11B2 mRNA was demonstrated in both kidney tissue and cultured renal tubular epithelial cell. We have also identified CYP11B2 mRNA expression in liver and lung of rats. In situ hybridization showed that CYP11B2 mRNA was localized in the endoplasm of liver fat-storing cell (Ito cells) and type II alveolar cells of lung. CONCLUSIONS: These studies prove that kidney, liver and lung are able to produce aldosterone.

Aldosterone↗
PubMed1999

Killing effect of interleukin-2 and interferon-alpha activated leukemic bone marrow in remission on K562 leukemic cells.

OBJECTIVE: To evaluate the killing effect of interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) activated bone marrow cells on K562 cells. METHODS: Semi-solid colony and 3H-TdR incorporating method were used. RESULTS: Bone marrow from leukemia patients in remission was activated in vitro with IL-2 for 3 days. The activated bone marrow (ABM) displayed killing effects of 0.31-2.30 logs on K562 cells. This killing effect was further increased to 0.30-3.15 logs when IFN-alpha added with IL-2 to the marrow for activation. IL-2 alone or in combination with IFN-alpha showed no inhibition of CFU-GM and K562 cells. Compared with IL-2 or IFN-alpha alone, the combination of the two cytokines could more effectively maintain the killing effect of ABM on leukemic cells. CONCLUSIONS: IFN-alpha can augment the purging effect of IL-2 ABM and combination of the two cytokines can effectively maintain the cytotoxicity of ABM.

Acute Disease↗
PubMed1999

A feasible and effective technique for the detection of Schistosoma japonicum cercaria-infested water.

OBJECTIVE: To develop a new technique for detecting Schistosoma japonicum (S. japonicum) cercariae so as to predict the distribution of area with high transmission potential and to control acute infection of schistosoma. METHODS: A C-6 film was established and used to adhere the cercariae on water surface and compared with a few other conventional detecting techniques. RESULTS: The average rate of the cercaria-recovery was 40% in laboratory and field using C-6 film, which was 20 times higher than that of traditional nylon-tissue adsorbing and precipitating method. Either in some areas where oncomelania were present or in some places where the snail had been under control, the technique could detect the cercariae. CONCLUSION: The technique can be characterized by a feasible, economical, promptly accessible method, especially for field application.

Animals↗
PubMed1999

[Signal of the cytoplasmic regions of leukemia inhibitory factor receptor (LIFR) alpha-subunit and gp130 involves Stat3 activation in leukemic U937 cells].

OBJECTIVE: In order to understand the mechanism of proliferation and differentiation of leukemia cells, we investigate the relation between the cytoplasmic regions LIFR alpha-subunit and gp130 and the transcription activator Stat3 in human leukemic U937 cells. METHODS: The cytoplasmic domain was each truncated from the LIFR alpha-subunit and gp130. The truncated forms of LIFR alpha-subunit(gp190EX) and gp130 (gp130EX) which can compete with the wild type receptor for binding to leukemia inhibitory factor (LIF) were expressed on the membrane of U937 cells. The level of Stat 3 and its phosphorylation were estimated by immunoblotting. RESULTS: The increased level of Stat3 and its decreased tyrosine phosphorylation were detected in each group of gp130EX and gp190EX as compared with that in the wild type receptor subunit group. CONCLUSION: The cytoplasmic domains of both LIFR alpha subunit and gp130 involve the induction of Stat3 phosphorylation in U937 cells.

Antigens, CD↗
PubMed1999

[Inhibition of hematopoiesis by sera from patients with myelodysplastic syndromes].

OBJECTIVE: To explore the inhibitory effect of sera from patients with myelodysplastic syndromes (MDS) on the growth of normal hematopoietic progenitor cells. METHODS: The inhibitory activity to the growth of BFU-E and CFU-GM was analysed by in vitro methylcellulose culture. Hematopoietic cell apoptosis was assayed with a programmed cell death assay kit and flow cytometry. RESULTS: In the 23 MDS patients studied, a potent inhibitory activity to CFU-GM and BFU-E was demonstrated in 3 and 4 patients, respectively. The inhibitory activity to BFU-E of sera from 3 patients was almost entirely neutralized by anti-TNF alpha McAb. Sera from two MDS patients induced apoptosis of normal hematopoietic progenitor cells. CONCLUSION: Inhibitors of hematopoietic progenitor cells are present in sera from some MDS patients. One of the inhibitors might be TNF alpha, which can induce apoptosis, resulting in ineffective hematopoiesis in MDS.

Adult↗
PubMed1999

Up-regulation of phosphatidylinositol 3-kinase in psoriatic lesions.

OBJECTIVE: To explore the relationship between phosphatidylinositol 3-kinase (PI 3-kinase) and psoriasis. METHODS: We constructed eukaryotic expression vector PcDNA 3-PI 3-kinase, by which digoxin-labeled RNA probe of PI 3-kinase was generated. After that, we detected the expressions of PI 3-kinase in the skins of twelve patients with plaque psoriasis and five normal subjects by dot blot, in situ hybridization and immunohistochemistry. RESULTS: The expression of PI 3-kinase mRNA and protein in psoriatic lesions increased obviously compared with that in normal skin. The expression of the PI 3-kinase gene conformed to the expression of its protein in psoriatic and normal human skins. CONCLUSIONS: Over-expression of PI 3-kinase may be related to the hyperproliferation of psoriatic keratinocytes. Transfection of the anti-sense gene of PI 3-kinase into psoriatic keratinocytes might be a best way to elucidate the issue.

Adolescent↗
PubMed1999

[Immunohistochemical study of angiogenesis of axillary lymph node metastasis in human breast carcinoma].

OBJECTIVE: To study angiogenesis of axillary lymph node metastases (including micrometastatic foci and metastatic tumors) in breast carcinoma and the relationship between microvessel density (MVD) and metastasis. METHODS: Thirty-seven breast cancer tissues and 121 metastatic axillary lymph nodes were collected from breast cancer patients and studied immunohistochemically. MVD was counted by means of microvideo system under 100x magnification. The diameter of each micrometastasis was measured with a micrometer. RESULTS: The mean diameter of 13 micrometastatic foci was 210 +/- 37 microns. No blood vessel formation was found. MVD of the primary tumor and that of metastatic tumor in the axillary lymph node was 93.8 +/- 21.8 and 89.3 +/- 18.4, respectively (P > 0.05). The distribution of microvessels of the metastatic tumor in the lymph node and that of the primary tumor was similar, being higher at the periphery than at the center. CONCLUSION: Micrometastatic foci of breast carcinoma in the axillary lymph node do not have new blood vessel formation. Their further growth, however, depends on neo-angiogenesis. Treatment based on inhibition of angiogenesis may be efficacious in the prevention of micrometastatic foci from developing into metastatic tumor in lymph node.

Axilla↗
PubMed1999

[The combined therapy of carboplatin, fluorouracil and radiotherapy for moderate and advanced non-small cell lung cancer].

OBJECTIVE: To observe the effect of combined chemotherapy (carboplatin and fluorouracil) with radiotherapy for moderate and advanced non-small cell lung cancer. METHODS: Eighty patients with moderate and advanced non-small cell lung cancer were randomized into 2 groups, radiotherapy group(R) and carboplatin, fluorouracil plus radiotherapy group (CF + R). All patients in two groups received conventional radiotherapy. Patients in CF + R group received combined chemotherapy with carboplatin(100 mg, d 1-5) 5-fluorouracil(500 mg d 1-5) in the first and fourth weeks during radiotherapy. RESULTS: The complete response rate was 48% in CF + R group, 25% in R group. The 1-year, 3-year, 5-year survival rates were 63%, 38%, 18% in CF + R group, and 40%, 15%, 8% in R group. The major toxic reactions in CF + R group were grade I-II myelo-suppression and digestive tract reaction. CONCLUSIONS: Combined chemotherapy(carboplatin and fluorouracil) with radiotherapy is preferable for non-small cell lung cancer.

Aged↗
PubMed1999

[Clinical study of advanced nasopharyngeal carcinoma treated with radiotherapy combined with DDP and vindesine].

OBJECTIVE: To evaluate the result of radiotherapy combined with chemotherapy for advanced nasopharyngeal carcinoma (NPC). METHODS: From August 1996 to October 1997, 64 cases of advanced NPC (stage N2-N3) patients were randomized to receive radiotherapy (RT) alone or RT combined with 2 cycles of chemeotherapy (CT) (cisplatin, vindesine). Thirty two patients were assigned to CT + RT, and 32 to RT alone. RESULTS: At 40 Gy of RT the response rate was 28.1% in RT group and 43.8% in CT + RT group. The response rate at 3 months after RT was 75.0% in RT group and 84.4% in CT + RT group (P < 0.05). The major toxic effects were gastrointestinal reaction, myelosuppession and alopecia. CONCLUSION: Chemotherapy with cisplatin and vindesine before and after radiotherapy increases the response rate of advanced NPC with lymph node metastases.

Adult↗
PubMed1999

[Surgical treatment of ovarian malignant tumors metastasized to the gastro-intestinal tract: a report of 131 cases].

OBJECTIVE: To investigate the value and feasibility of surgical excision of gastro-intestinal metastatic tumors in patients with ovarian malignancy. METHODS: The surgical and clinical data were retrospectively reviewed in 131 cases of ovarian malignant tumor with surgically excised gastrointestinal metastasis (> or = 2 cm in diameter). RESULTS: Ovarian malignant tumor with gastro-intestinal metastasis accounted for 28.9% of the patients with primary ovarian malignancies in the same time period. Of the 131 cases, 126(93.9%) were in stage III and IV. The treatment was surgical excision combined with chemotherapy. Of the 141 operations, 83 (58.9%) were done by stripping of tumors on the gastro-intestinal wall and repair, 31(22.0%) received resection of the involved segment of the bowel with anastomosis, 27(19.2%) with colostomies. Postoperative complications occurred in 26.9% of the operated patients. The overall 2- and 5-year survival rate was 79.7% and 42.5%, respectively. CONCLUSION: Surgical excision of gastro-intestinal tumors metastasized from primary ovarion malignancies is feasible to achieve cytoreduction. Prognosis can be improved when combined with chemotherapy.

Adolescent↗
PubMed1999

[Effect of unilateral condylar fracture on stress distribution in the mandible].

OBJECTIVE: To investigate the effect of unilateral condylar fracture on stress distribution in the mandible in order to realize primarily the biomechanical mechanism of temporomandibular joint disorders (TMD) resulted in by joint injury. METHODS: The stress distributions in the mandible of a normal human and a patient with TMD induced by right condylar fracture following malposition healing were analyzed and compared quantitatively during centric occlusion by three-dimensional finite element method. RESULTS: The patient contained the unbalanced stress distribution in the mandible, such as different nature and value of stress. The stress in the fractured side was higher than the non-fractured side, in which condyle is more evident. The maximum principal stress and minimum principal stress of each region in his mandible were much higher than that in a normal mandible. Its stress quality changes also. The stress in his mandible was distributed asymmetrically. CONCLUSION: Unilateral condylar fracture not only damaged its structure, but also induced the badness of its biomechanical environment, in which condyle was the most sensitive region during the stresses in the mandible were changed. It was preliminarily thought that unbalanced stress distribution, evidently increased stress and varied stress character were one of biomechanical mechanism of TMD.

Adult↗
PubMed1999

[Genetic analysis of tooth development and eruption in 82 pairs of female-female twins].

OBJECTIVE: To study the heritability of tooth development and eruption. METHODS: 82 pairs of female-female twins between 6-12 years old were collected. Twin zygosity diagnosis were made by DNA-fingerprinting. The number of third molar present, hypodontia, upper lateral incisor malformation and the number of erupted permanent teeth were recorded by oral examination and panoramic radiographs, their heritabilities were calculated. RESULTS: According to the level of heritability, the dental traits were aligned as follows: the number of third molars present, the upper lateral incisor malformation, hypodontia and the number of erupted permanent teeth. CONCLUSION: Though both the tooth development and its eruption were under genetic influence, the heritability of tooth development was far more than tooth eruption.

Adolescent↗
PubMed1999

[Effect of compound Chinese drug bailong on the expression of tumor suppressor genes and relationship with prekallikrein activator signal pathway in human gastric carcinoma BGC82-3 cell line].

OBJECTIVE: To study the effect of compound Chinese drug Bailong on the transcription of Cyclin Dependent Kinase Inhibitor (CKI) p16INK4a, p21 and Rb, c-myc genes, and the relationship between gene expression and cAMP-PKA pathway. METHODS: Using the traditional molecular biology methods (cell synchronization, molecular hybridization--Western blotting, Northern blotting, etc.) examine the gene expression. RESULTS: Bailong promoted the expression (both mRNA and protein) of p16INK4a obviously in G1 phase cells. When prekallikrein (PKA) inhibitor was added in the cells which were treated by Bailong, the mRNA and protein level of p16INK4a decreased. It was shown that the inhibited proliferation of BGC82-3 cell by Bailong may come from the enhanced p16INK4a gene expression in G1 phase. Being same as p16INK4a, tumor suppressor genes Rb, p21 and oncogene c-myc expression were all affected by Bailong. When PKA inhibitor was added, the results were reversed. CONCLUSION: Bailong can affect many anticancer genes (including p16INK4a, p21 and Rb genes) and oncogenes (including c-myc) transcription by regulating cAMP-PKA pathway.

Cyclin-Dependent Kinases↗
PubMed1999

[Effect of bailong recipe on proliferation phenotype of human gastric carcinoma BGC82-3 cell line].

OBJECTIVE: To observe the reversive effect of Composite Bailong recipe (BR), a preparation of Chinese herbal medicine, on proliferation phenotype of human gastric carcinoma BGC82-3 cell line. METHODS: Observation was conducted by using growth curve, colony on soft agar and nude mice oncogenesis experiment. RESULTS: Growth curve showed the proliferation of BGC82-3 cell was obviously inhibited by BR, the inhibiting rate reached 86% in the 5th day. The colony was few and small on soft agar after treated with BR, only accounted for 52% as compared with that of nontreated. BR obviously inhibited the oncogenesis of BGC82-3 cells in nude mice, the inhibition rate being 50%. CONCLUSION: Composite BR has obvious inhibiting action on malignant proliferation of human gastric BGC82-3 cell line.

Animals↗
PubMed1999

[Study on relationship between insulin-resistance and syndrome differentiation typing in hypertensive patients].

OBJECTIVE: To find the relationship between insulin-resistance and Syndrome Differentiation typing (SDT) in hypertensive patients. METHODS: Two hundred and nine patients of early stage hypertension with no complication of heart, brain or kidney were selected and classified into 4 types according to SDT, the Liver-Fire exuberant type (A), the Phlegm-Dampness abundant type (B), the Yin-Deficiency and Yang-Excess type (C) and the both Yin-Yang Deficiency type (D). Their insulin sensitivity were examined and compared with that of 40 healthy subjects. RESULTS: (1) Compared with healthy subjects, all hypertensive patients had apparent insulin resistance (P < 0.05). If the insulin sensitivity of healthy subjects was defined as 1, that of patients of type A, B, C and D were 0.54, 0.58, 0.65 and 0.80 respectively. (2) Comparison between the insulin sensitivity of type A, B and C showed no significant difference, while they were compared with type D, the difference was significant (P < 0.05), that is, the insulin sensitivity of type D was close to that of healthy subjects. (3) The fasting blood insulin of type D was obviously lower and the insulin sensitivity of type D was obviously higher than that of the other three types (P = 0.0001). (4) After adjusting age, sex and body mass indexes, multivariate regression analysis demonstrated that insulin sensitivity was closely correlated with SDT (P = 0.0001). CONCLUSION: Insulin resistance is one of the pathological basis for SDT in hypertension.

Adult↗
PubMed1999

[Primary sarcoma of pulmonary artery: a case report].

OBJECTIVE: To call attention to the rare involvement of pulmonary artery by sarcoma. METHODS: To summarize the clinical, radiological and pathologic features of a case of pulmonary artery sarcoma. RESULTS: Pulmonary artery sarcoma has similar clinical manifestations as other pulmonary artery obstructive diseases (including pulmonary thromboembolism). The diagnosis should be considered in the patient with clinical presentations suggested pulmonary embolism. The radiological findings included unilateral hilar enlargement, contiguously soft tissue-filled pulmonary artery and pulmonary nodules and clinically deterioration was found after anticoagulant therapy. CONCLUSION: Pulmonary artery sarcoma is usually misdiagnosed as other pulmonary artery obstructive diseases. More attention should be paid to it.

Adult↗