Biomedical subjects

J Liu

Publications and source records attributed to J Liu.

At least 811 records · Page 45Linked to original sources

PubMed2000

The role of membrane potential and calcium kinetic changes in the pathogenesis of vascular hyporeactivity during severe shock.

OBJECTIVE: To determine the role of membrane potential and intracellular calcium kinetic changes in producing vascular hyporeactivity during severe hemorrhagic shock. METHODS: Rats were subjected to hemorrhagic shock (HS) for 2 hours. The spinotrapezius muscle was prepared for microscopy and the responses of arterioles in the muscle to norepinephrine (NE) were tested. The resting membrane potentials of isolated arterial strips were measured with a microelectrode. Membrane potential and intracellular Ca2+ ([Ca2+]i) changes in isolated arteriolar smooth muscle cells (ASMCs) were determined with fluorescent probes and a confocal microscopy. RESULTS: The arteriolar resting membrane potential was decreased from -36.7 +/- 6.3 mV in control to -29.2 +/- 5.3 mV concurrent with the increase of vasoreactivity to NE at 20 minutes after HS. At 120 minutes post-HS, the resting potential hyperpolarized to -51.9 +/- 9.1 mV, and NE stimulated [Ca2+]i increase was reduced to 50% of the control values during the appearance of arteriolar hyporeactivity, i.e. the NE threshold of the arteriolar response increased 15 fold 2 hours after the onset of hemorrhage as compared with normal animals. The state of vasoreactivity was closely related to the resting potential of vascular smooth muscle in hemorrhagic shock, with a correlation coefficient of 0.96. Treatment with glybenclamide, a selective blocker of ATP-sensitive K+ (KATP) channels, decreased the resting potential, increased NE-stimulated [Ca2+]i increase, and partially restored vasoreactivity in severe hemorrhagic shock. CONCLUSION: The results suggested that membrane hyperpolarization and the reduction of NE-stimulated [Ca2+]i increase in smooth muscle cells appeared to contribute to the vascular hyporeactivity in hemorrhagic shock. The mechanism is likely to involve in KATP channels.

Animals↗

PubMed2000

Biological function of a novel gene overexpressed in human hepatocellular carcinoma.

OBJECTIVE: To clone the full-length of a differentially expressed cDNA fragment, LC27, and study its biological function tentatively. METHODS: Northern blot was used to analyze the expression pattern of LC27 in hepatocellular carcinoma, matched nontumor liver tissues, fetal liver and normal adult liver tissues, as well as BEL-7402 hepatocellular carcinoma cell line ESTs splicing and 5' rapid amplification of cDNA ends (5' RACE) were used to clone the full-length of LC27 cDNA. An antisense oligodeoxynucleotide approach was used to investigate the biological role of the gene in the proliferation of BEL-7402 cells. RESULTS: A 2186 bp novel cDNA with an open reading frame encoding a 283 amino acid protein was cloned. Analysis of the deduced amino acid sequence indicated that it is 38% (88/229) identical to human Golgi 4-transmembrane spanning transporter MTP. The gene and the encoded protein was termed hepatocellular carcinoma overexpressed transmembrane protein (hotp) and HOTP, respectively. Hotp mRNA was almost undetectable in normal adult liver and fetal liver tissues. However, it was significantly up-regulated in hepatocellular carcinoma and some matched nontumor liver tissues, as well as BEL-7402 cells. The proliferation of BEL-7402 cells was suppressed by an antisense oligodeoxynucleotide against hotp mRNA at a concentration of 50 micrograms/ml. CONCLUSION: HOTP may be an integral membrane transporter protein. The overexpression of the gene in hepatocellular carcinoma may play an important role in hepatocarcinogenesis and disease progression.

Adult↗

PubMed2000

Vitamin D receptor gene polymorphism in postmenopausal women of the Han and Uygur nationalities in China.

OBJECTIVE: Polymorphism in vitamin D receptor (VDR) gene has been reported to play a major role in variations for genetic regulation of bone mass. Its role within various ethnic populations is not clear. The purpose of this study was to determine the frequencies of VDR genotypes in the Han and Uygur nationalities in China. METHODS: We analyzed the polymorphism of Bsm I restriction enzyme by PCR-RFLP technique in 162 healthy postmenopausal women of the Han nationality and 50 healthy postmenopausal women of the Uygur nationality in China. The genotype frequencies of VDR were calculated using Hardy-Weinberg equilibrium formula. RESULTS: In the Han nationality, the bb, Bb, and BB genotype accounted for 91.36%, 8.64% and 0%, respectively. In the Uygur nationality, frequencies were 74.00%, 18.00% and 8.00%, respectively. CONCLUSION: There was a significant difference between the Han and Uygur nationalities in the frequency distribution of VDR genotype (P < 0.01). Compared with the Caucasian population in the United States, Australia and France, there was a similar value to Uygur nationality in the BB genotype. This investigation gave us further evidence on the different etiopathology of osteoporosis in various ethnic groups.

Alleles↗

PubMed2000

A comparative study of the dose-response and time course of recovery of atracurium and rocuronium.

OBJECTIVE: To compare the characteristics of the dose-response relationship and the time course of action between atracurium and rocuronium in adult patients anesthetized with N2O-O2-fentanyl-thiopene. METHODS: Sixty patients, ASA grade I, aged 18-50 years, scheduled for elective plastic surgery were studied. All patients were randomly divided into either the atracurium or rocuronium group. General anesthesia was maintained with 60% nitrous oxide and 40% oxygen, thiopentone, and fentanyl. Neuromuscular function was assessed using an accelograph with train-of-four (TOF) stimulation at the wrist every 12 seconds. The percentage depression of the first twitch (T1) was used as the study parameter. The dose-response relationship of atracurium and rocuronium was determined by the cumulative dose-response technique. RESULTS: According to the dose-response curves established by a least squares linear regression, the potency ratio of atracurium to rocuronium was 1:1.2. There were significant differences in the ED50, ED90, and ED95 between the two drugs. After the intravenous administration of equipotent doses of both drugs (1.5 x ED95), the duration of peak effect, clinical duration, and total duration were significantly different between the two drugs, but their recovery indexes were similar. CONCLUSIONS: Atracurium and rocuronium are low-potency nondepolarizing relaxants with intermediate duration. As compared to atracurium, the neuromuscular blocking effect of rocuronium was about 20% less potent and its duration of action was shorter.

Adolescent↗

PubMed2000

[Establishment of in vitro serum-free embryo implantation model].

OBJECTIVE: To observe the growth and implantation of mouse embryos in vitro. METHODS: In order to establish a serum-free coculture system, the whole components of decidual tissue was collected and cultured in vitro. Then 4-day-mouse embryos were added to the well-developed decidual cells, and the following changes of the above system were closely observed under microscope. RESULTS: Mouse embryos were successfully hatched, adhered, implanted and outspreaded under the coculture system. The extraplacental cone and amniotic sac were formed as well. Decidual cells kept stable during the following 4-day coculture. CONCLUSIONS: Decidual cell is an ideal feeder cell for coculture. Our results showed that the modified method of decidual cell culture and the establishment of implantation model were simple, practical and reliable.

Animals↗

PubMed2000

[Retinoic acid enhances chemosensitivity of medulloblastoma cells in vitro and its potential mechanism].

OBJECTIVE: To elucidate the chemosensitivity of retinoic acid (RA)-differentiated medulloblastoma Med-3 cells to conventional anti-cancer drug and to determine the potential genetic factor(s) mediating this sensitivity. METHODS: Ten mumol/L RA, 5 micrograms/ml cisplatin (DDP) and their combination with one half concentration of each were used respectively to treat human medulloblastoma cell line Med-3 in vitro. Cell proliferation, morphology and death pattern as well as Fas/FasL expressions were analyzed by multiple approaches. RESULTS: Both soluble and membrane FasL could be detected in the treated and untreated Med-3. Fas was positive in the cytoplasm of Med-3 cells and the cells could produce soluble Fas. DDP had no obvious effect on Fas expression. RA up-regulated Fas expression and translocalization from cytoplasm to cell membrane of the treated cells. Neither RA nor DDP could trigger apoptosis but in combination could effectively induce apoptosis. CONCLUSION: RA could enhance the apoptotic susceptibility of Med-3 cells to DDP presumably through modulating the Fas expression pattern. Combined RA/DDP regimen would have potential clinical value in the management of medulloblastomas.

Antineoplastic Agents↗

PubMed2000

[Cloning and antitumor activity of angiogenesis inhibitor HIAF-1].

OBJECTIVE: A new angiogenesis inhibitor HIAF-1 (human inhibitor angiogenesis factor-1) was cloned, expressed in E. coli and its antitumor activity was studied. METHODS: HIAF-1 was amplified by RT-PCR from human fetal liver tissue, then cloned into pET30a(+) vector and expressed in E. coli BL21:DE3 after sequencing. In vitro endothelial proliferation inhibiting activity of HIAF-1 was examined by MTT method. In vivo antitumor activity was studied in a murine model of IVTA2MA-891. RESULTS: HIAF-1 was first cloned from human fetal liver tissue. Sequence analysis of the inhibitor revealed identity to a c-terminal fragment of human collagen XVIII. HIAF-1 was effectively expressed in E. coli with a yield of 88 mg/L. Recombinant HIAF-1 protein could inhibit endothelial cell proliferation in vitro with an IC50 value of 7.5 micrograms/ml. In vivo studies showed that HIAF-1 inhibited growth rate of the primary tumor by 46.6% and metastasis by 68.9%. CONCLUSION: The cloned and the bio-engineering product of HIAF-1 is an angiogenesis inhibitor, capable of inhibiting tumor growth and metastasis.

Angiogenesis Inhibitors↗

PubMed2000

[Cytomegalovirus infection and the changes of T-lymphocyte subsets in RAU patients].

OBJECTIVE: To study the quantitative changes of the T-lymphocyte subsets in RAU patients with different stages and to know the influences of cytomegalovirus(CMV) on cellular immunity in RAU patients. METHODS: CD4(helper/inducer) and CD8(suppressor/cytotoxic) cells in the peripheral blood were tested with monoclonally immunocytochemical technique (APAAP method) in 26 ulcerative stage patients and 10 inactive patients. RESULTS: The percentages of CD4 and CD8 cell were 36.19% and 29.38% respectively in ulcerative stage. The ratio of CD4/CD8 was 1.28 and it was inverted (< 1.0) in 26.92% of the patients. The percentages of CD4, CD8 cells was 39.90% and 34.21% in inactive stage respectively. The ratio of CD4/CD8 was 1.17. The number of CD4 and CD8 cells in ulcerative stage and CD4 cells in inactive stage was significantly lower than the normal values, P < 0.05. The number of CD8 cells in inactive stage was not significantly different compared with the normal value. However the numbers of CD3(total T cells), CD4 and CD8 cells increased to some extent in inactive stage. CD4 cells was significantly lower in 11 human cytomegalovirus (HCMV) DNA positive patients than that in 9 HCMV DNA negative patients (P < 0.05). CONCLUSIONS: A permanent disorder of cellular immunity was an important part of pathogenesis in RAU. CMV infection may be an important factor resulting in the disorder of cellular immunity because of the imbalance of T lymphocyte subsets.

Adolescent↗

PubMed2000

[Clinical study on Zhuyu Xiaozhong mixture combined with stereotaxic drainage in treating hypertensive cerebral hemorrhage].

OBJECTIVE: To explore the effective method of integrated traditional Chinese and western medicine (TCM-WM) therapy in treating hypertensive cerebral hemorrhage (HCH). METHODS: Sixty-one HCH patients were randomly divided into two groups: the treated group (group A, 31 cases) and the control group (group B, 30 cases), the former group was treated with stereotaxic drainage and orally taken Zhuyu Xiaozhong mixture (ZYXZM), and the latter group with stereotaxic drainage alone. RESULTS: The total effective rate of group A was 83.9%, significantly higher than that of group B (60.0%, P < 0.05). In comparing the two groups, the neurological function recovery, the quality of life and the hematoma absorption in group A were significantly better than those of group B (P < 0.05). CONCLUSION: ZYXZM combined with stereotaxic drainage is effective in treating HCH. It could promote the neurological function recovery and improve the quality of life as well.

Aged↗

PubMed2000

[The value of nuclide myocardial scintigraphy for the clinical of acute viral myocarditis].

OBJECTIVE: To investigate the significance of nuclid myocardial scintigraphy (ECT) as a clinical method for guiding the diagnosis, therapy and prognosis of a cute viral myocarditis. METHODS: 48 patients with acute viral myocarditis were divided into two groups, 21 patients with ECT showing diffuse myocardial perfusion defect constituted a positive group and the remaining 27 with normal ECT a negative group. The relationship between the clinical data and treatment effect in the two groups were analyzed. RESULTS: In the positive group, CK-MB in 57.14% of the patients was higher than normal and 71.43% of the patients had ventricular premature beats (VPB) and atrial premature beats (APB). The average number of VPB per 24 hour was (4228 +/- 1506) beats. In the negative group, the values of the above items were 33.33%, 44.44% and (2268 +/- 924) beats. The difference between the two groups was statistically significant (all of P < 0.01). After treatment of acute viral myocarditis, ECT of all the patients in the positive group returned to normal completely 85.71% of the patients with premature beats recovered from the arrhythmia. 38.10% of the patients with premature beats had arrhythmia again during a follow-up of 4 years. However, in the negative group, only 59.26% of the patients with premature beats recovered from the arrhythmia and 66.67% had arrhythmia again during the 4 years. The therapeutic effect between the two groups was also statistically different (all of P < 0.01). CONCLUSION: Up to now, there has been no unified diagnostic standard for acute viral myocarditis, so ECT may be an exact and reliable diagnostic method for acute viral myocarditis. It may help to avoid error in diagnosis, waste in health resources and side effects of the medications.

Acute Disease↗

PubMed2000

[Etiological study on patients with seronegative viral hepatitis].

OBJECTIVE: To investigate the etiology of hepatitis patients who were seronegative for viral hepatitis A through E. METHODS: By using PCR, HBV DNA, HCV RNA, HEV RNA and HGV RNA were detected in sera of 104 patients with seronegative viral hepatitis. The partial nucleotide sequences of 2 HCV and 17 HEV isolates were analysed by direct sequencing. RESULTS: Among the 104 patients with seronegative viral hepatitis, the positive rates of HBV DNA, HCV RNA, HEV RNA and HGV RNA were 29.8%, 3.8%, 22.1% and 7.7%, respectively, with only 38 cases (36.6%) negative for the genome of all known hepatitis viruses. CONCLUSION: In addition to serological tests, the polymerase chain reaction of all known hepatitis viruses should be used to make the diagnosis of non-A - E hepatitis.

Base Sequence↗

PubMed2000

[Function of one novel gene identified by SSH PCR differentially expressed in HBX transfected HepG2 cells].

OBJECTIVE: To clone full length differentially expressed genes which are related with HBxAg. METHODS: HepG2-cells were infected with prepared recombinant retroviruses encoding the X antigen. The differences in gene expression between HepG2 x and HepG2Cat cells were evaluated by suppression subtractive hybridization and PCR. In situ hybridization (ISH) and Northern blot analysis were carried out to screen the differentially expressed genes. The full length cDNA clone of the gene was obtained by 5' and 3' rapid amplification of cDNA ends(race) PCR. HepG2 cells transiently transfected with the new full length gene were subjected to fluorescence activated cell sorting (FACS) analysis for DNA content. HepG2 cells stably transfected with the new full length gene were tested for anchorage independent growth in soft agar and for tumorigenicity in nude mice. RESULTS: The expression of multiple genes were turned on (8) or off (2) in HepG2X compared to HepG2CAT cells. One differentially expressed gene C2, the human homology of Sui1, encoded a translation initiation factor whose expression was suppressed by X antigen in HepG(2) cells. The full length of this gene was 1.35 kb, which encoded a small protein of 113 amino acids. Introduction of C2 into HepG2 cells could inhibit cell growth in culture, in soft agar, and partially inhibit tumor formation in nude mice. Cells transfected with pcDNA3-HBx showed little or no detectable C2, which was consistent with the suppression of this protein in the presence of HBxAg. C2 was also expressed in nontumor liver, but not in tumor cells from patients with hepatocellular carcinoma. CONCLUSIONS: HBX can regulate the expression of genes whose products may be positive or negative regulators of cell growth. Our work for the first time demonstrates that the mechanism of DNA virus associated carcinogenesis involves altered patterns of gene expression regulated at the level of translation initiation.

Amino Acid Sequence↗

PubMed2000

[A new strategy of gene therapy for hyperphenylalaninemia rats].

OBJECTIVE: To construct a recombinant vector which expresses active phenylalanine-amonia-lyase (PAL) in Lactococcus lactis (L. L.), and to convert phe into cinnamic acid in small intestine by the engineering L. L. to decrease the phe level in the peripheral blood, and to cure hyperphenylalaninemia rats. METHODS: PAL cDNA from Petroselinum crispum was subcloned into expression vector pMG36e and transformed L. L. The pMG36ePAL/L.L. was screened and characterized by using PCR and HPLC, and prepared as enteric-coated microcapsules and oral liquid type preparation that were given orally to hyperphenylalaninemia-rats. RESULTS: Engineering L. L. expressing PAL activity was obtained. The phe levels plasma of in the rats receiving preparations made from the engineering L. L. were significantly reduced compared with non-treated hyperphenylalaninemia rats. And the effects of different preparations were different from each other. CONCLUSION: The engineering L. L. expressing PAL activity can reduce the blood phe level of the hyperphenylalaninemia rats. This may be a potential way for PKU gene therapeutics.

Administration, Oral↗

PubMed2000

[Surgery for lung cancer complicated by bronchial asthma].

OBJECTIVE: To assess surgery for lung cancer complicated by bronchial asthma. METHODS: Lung hilum denervation was performed for asthma during radical resection of lung cancer. One patient with peripheral bronchogenic carcinoma in the right upper lobe underwent upper lobectomy and extensive dissection of lymph-nodes. Simultaneously, lung hilum denervation was done by complete amputation of the sympathetic and parasympathetic nerves around the lung hilum. Another patient with central bronchogenic carcinoma in the left upper lobe underwent lung autotransplantation. Pneumonectomy was performed, and the tumor parts of the lung were resected subsequently and the preservable parts of the lung were replanted into the bed of the upper lobe. RESULTS: Follow-up showed that the two patients had been alive with tumor free for 80 months and 17 months respectively and the time of postoperative mechanical ventilation was 4 and 18 hours. The frequency of asthma paroxysm decreased and the severity attenuated. Parameters of blood gas and lung function were improved. CONCLUSIONS: The poor lung function caused by asthma should not be regarded as a contradiction for the removal of lung cancer. Complete denervation around the lung hilum during the radical resection of lung cancer may contribute to the better treatment of lung cancer and asthma.

Aged↗

PubMed2000

Lung autotransplantation technique for treating central lung cancer of upper lobe.

OBJECTIVE: To assess the feasibility of applying lung autotransplantation technique in the treatment of central lung cancer of the upper lobe. METHODS: Two patients underwent double-sleeve right upper and middle bilobectomy. Because the length of resected bronchus or pulmonary artery involved by tumor was too long to perform tension-free anastomosis, we had to transplant the lower lobar vein into the proximal stump of the upper lobar vein. Another two patients underwent pneumonectomy firstly, because we could not perform sleeve lobectomy in suit as the tumor extended through the oblique fissure to the margin of the lower lobe. Subsequently, we resected the tumor parts at a separate table, and replanted the preservable part of the lung into the chest. RESULTS: Being followed up to December 1999, the patient 1, 3 and 4 had been alive with tumor free for 31, 18 and 13 months. The patient 1 and 3 had a good living quality but the patient 4 had a very poor activity. The patient 4 received resection of the replanted lung for pulmonary artery bronchus pleural fistula on the 42nd day after operation. The second patient died of tension pneumothorax associated with bronchopleural fistula on the 19th day after operation. CONCLUSION: Lung autotransplantation is an alternative technique for pulmonary preservation in patients with stage III central lung cancer of the upper lobe whose cardiopulmonary function is too poor to undergo pneumonectomy.

Aged↗

PubMed2000

[Complications of massive allografts after segmental resection of malignant bone tumors].

OBJECTIVE: To analyze the postoperative complications of bone and joint allografting for the reconstruction of massive bone defect after the resection of malignant bone tumors and its management. METHODS: Bone-joint allografting for the reconstruction of massive bone defect after the resection of malignant bone tumors with different internal fixations was performed in 106 patients with complete follow-up data. Bone healing time, complication rate, and final results in different allografts were compared. Operation indications, complications and internal fixation were also analyzed. The final results were determined according to the Mankin's standard. RESULTS: Allografts Alcohol immersed were more susceptible to infection, non-union, etc. Allografts and combined prosthesis were superior to semi-articular transplantation. Complications included deep infection (10%), skin necrosis (12.2%), local recurrence (14.4%), and delayed union or non-union (15.6%). Dynamic interlocked intramedullary nailing was superior to conventional intramedullar nailing and compression plates. CONCLUSIONS: Allografting is acceptable for the reconstruction of massive bone defect after tumor resection. Its results are encouraging after proper management of complications caused by surgical technique, internal fixation and soft tissue repair.

Adolescent↗

PubMed2000

[Expression and significance of AR in osteosarcoma].

OBJECTIVES: To determine the relationship between AR and pathological characteristics of osteosarcoma and to investigate the potential role of AR in the pathogenesis of osteosarcoma. METHODS: AR in the samples of the paraffin embedded tissues from 65 cases of osteosarcoma was immunohistochemically detected by streptavidin/peroxidase (SP) method. The pathology of osteosarcoma was classified and graded according to Liu Zijun's Classification. RESULTS: The positive rate of AR was 50.8% (33/65). The positive particles were distributed in the cytoplasm and nucleus. The positive rate of AR in osteosarcoma with higher grade of cell differentiation was lower than that in the tumor with lower one. There was no significant difference in different pathological type of osteosarcoma. CONCLUSION: AR exists in osteosarcoma and its positive rate is related to the cell differentiation of osteosarcoma.

Bone Neoplasms↗

PubMed2000

[Simultaneous pancreas-kidney transplantation for the treatment of type I diabetes with end-stage renal disease].

OBJECTIVE: To demonstrate whether simultaneous pancreas-kidney transplantation is practical for the treatment of Type I diabetes with end-stage renal disease. METHODS: Eight cases of combined pancreas-kidney transplantation were performed in our institute. The age ranged from 35 years to 48 years (average 43.46 years). All cases were diagnosed as type I diabetes with end-stage nephropathy, two cases with blindness due to retinopathy. The case history ranged from 2 years to 22 years. Pancreas allograft was placed in the right iliac fossa with pancreas exocrine drainage to bladder, whereas renal allograft the in left iliac fossa. Initial immunosuppression regimen is quadruple. RESULTS: Seven patient could be insulin free after transplantation, with normal fasting blood glucose. One patient received insulin treatment for 40 days after operation. One patient survived 1 year and 9 months after transplantation with normal functioning pancreas allograft and kidney allograft. Four patient survived 2 months with normal allograft function. Fasting blood glucose was between 4.5 and 6.2 mmol/L; Cr was between 53 and 106 micromol/L. Diet control was not necessary. Two patient died of encephalorrhagia, and 1 pancreatic vascular thrombosis and necrotic pancreatitis. CONCLUSIONS: Combined pancreas-kidney transplantation is feasible to treat type I diabetes with end-stage nephropathy. Functional pancreas allograft could be procured in the present condition. Pancreatic exocrine is drained to bladder. The diagnosis of acute rejection could be made earlier by detecting urine amylase. Heparin should be added in order to prevent pancreatic thrombosis.

Adult↗