Biomedical subjects

S Liu

Publications and source records attributed to S Liu.

At least 469 records · Page 26Linked to original sources

PubMed1999

[Study on the reversal of cancer multidrug resistance by Chinese medicine Fw13-te41 in nude mice].

We have reported that three reversal agents were sifted out from 32 Chinese galenicals through a series of cell culture tests. Among them, Fw13-te41 has the best effect of reversal cancer multidrug resistance (MDR) in vitro. In this study, the reversal action of Fw13-te41 in vivo was studied on the animal model of nude mice with human leukemia k562/ADR. Twenty SPF BALB/c-nu/nu nude mice with xenograft tumor were randomly divided into the control group (n = 6), VCR group [intraperitoneal (i.p.) VCR 250 micrograms/week, n = 5], VCR + Fw13-te41 group (i.p VCR 250 micrograms/week + Fw13-te41 0.2 ml/day, equivalent to crude drug 10 g/kg, n = 5), and Fw13-te41 group (i.p Fw13-te41 0.2 ml/day, equivalent to crude drug 10 g/kg, n = 4). After 18 days, the rate of tumor inhibition (RTI) of VCR group was 19.79%, but the RTI of VCR + Fw13-te41 group was as high as 86.95% (P < 0.05). There results demonstrate that the Chinese medicine Fw13-te41 has an evident reversal action of malignancy MDR in vitro and in vivo.

Animals↗

PubMed1999

[A study of color Doppler ultrasound on arteries of the extremities in patients with type 2 diabetes].

To investigate the changes of the arteries in extremities in patients with type 2 diabetes(DM2), fifty patients with DM2(35 women and 15 men, mean aged 57.54 +/- 14.19 years old, time of DM2 diagnosed one week-26 years, without the histories of hypertension and smoking) were studied. Radial, finger, anterior tibial and dorsum pedis arteries of all subjects were examined using color Doppler Ultrasonography, 30 of 50 patients had the symptoms of extremities (e.g., numbness, coldness and pain). The Doppler examination revealed: 1. In the patient group, arterial wall became thick, rough and rigid. The atherosclerotic plaques were found inside vascular cavities in 14/50 in patient group with one patient being asymptomatic of extremities. 2. The vascular cavities in patients remarkably narrowed compared with the control group (P < 0.05). The vascular lesion worsened along with the development of the symptoms. 3. Doppler spectra in the majority of patients displayed single-peak, whereas it displayed three peaks in normal subjects with significant differences (P < 0.05). 4. The peak flow velocities in the patients increased, and this increase was related to the development of the symptoms, but no significant differences were found. Color Doppler Ultrasound examination is valuable in the evaluation of the arterial lesion of the extremities, especially at the early stage of artery diseases in patients with DM2.

Adult↗

PubMed1999

Preliminary study on application of artificial neural network to the diagnosis of Alzheimer's disease with magnetic resonance imaging.

OBJECTIVE: Artificial neural network is first used in the measurement study of brain of Alzheimer's disease using MRI, and a completely new pattern discriminating method is adopted, so as to take advantage of MRI to diagnose and identify AD patients. METHODS: 12 patients with probable AD (aged 65.33 +/- 8.62 years) and 36 normal controls matched with age and gender (aged 65.81 +/- 74.37 years) were studied. MRI are performed on Siemens Magnetom IMPACT 1.0 T; eight interesting brain structures including sixteen regions (left and right) indices are measured and studied; SPSS software and BP network software made by authors respectively were used to process and analyze the measured data. RESULTS: Using artificial neural network to the same regions and data, both the sensitivity and accuracy were found higher than using the traditional discrimination function analysis method; the indices of amygdala, hippocampus, parahippocampal gyrus, temporal lobe, and temporal horn, these five structures could completely differentiate AD from normal controls; new cases were successfully diagnosed. CONCLUSIONS: Artificial neural network combining with MRI is probable to become a useful and reliable clinical tool to diagnose AD patients.

Aged↗

PubMed1999

Enzyme-linked immunoelectrotransfer blotting analysis of human serologic responses to infective hookworm larval antigen.

OBJECTIVE: To explore the possibility of using specific antigens for immunodiagnosis of hookworm disease in endemic area. METHOD: Infective third-stage larvae of the canine hookworm, Ancylostoma caninum (A. caninum), were prepared as the source of antigen. Enzyme-linked immunoelectrotransfer blotting (EITB) was employed as an immunodiagnostic method. RESULTS: Two immunodominant bands of hookworm antigens (42 kDa and 55 kDa) were recognized by the sera of hookworm-infected patients (serum dilution 1:200; antigen centrifuged at 36,000 r/m for 20 minutes, but not by sera from negative controls. CONCLUSION: The 42 kDa and 55 kDa A. caninum antigens might be the specific antigens that could be used for immunodiagnosis of hookworm disease in endemic area.

Ancylostoma↗

PubMed1999

Immunological characteristics of natural resistance in Microtus fortis to infection with Schistosoma japonicum.

OBJECTIVE: To explore the immunological characteristics of natural resistance to Schistosoma japonicum infection in Microtus fortis (MF) living in the Dongting Lake area. METHODS: Passive transfer of sera from uninfected laboratory bred MF (BMF) to albinao mice (AM) was performed to observe the acquired protection. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunoblotting (ELIB) methods were used to recognize 4 different life-cycle stage antigens of S. japonicum by sera from wild MF (WMF), BMF, BMF13 and BMF19. Tests were also performed on in vitro killing effect of sera and/or lymphocytes from BMF and WMF to schistosomulae; quantitative determination of C3 and C4 by immunoturbidometry, and interleukin-4 (IL-4) and antibodies to the 4 stage antigens in sera from WMF, BMF and infected BMF by ELISA. RESULTS: Compared with the control group, stool eggs per gram (EPG) of AM in the test group was significantly reduced by 81.54%, miracidium hatching rate, by 50.67%, liver egg counts, by 72.07%, the diameter of hepatic egg granuloma, by 70.39 microns. Western blotting probed with the 4 MF sera all revealed 7 specific bands for SSA, 3 for AWA and SEA, but none for CA antigens. The sera and/or lymphocytes from WMF and BMF gave obvious killing effects on schistosomulae with an adjusted death rate of 64.12%-78.83%. The levels of "natural antibodies" produced by MF to S. japonicum were in the following order: anti-SSA > anti-AWA > anti-SEA > anti-CA, all of which increased significantly after the infection. Serum levels of C3, C4 and IL-4 in uninfected BMF were significantly higher than those in AM. After infection, levels of C3 and C4 were further increased respectively by 72.83% and 295.49% in the 4th week and IL-4 by 303.83% in the 9th day. CONCLUSIONS: Immunological characteristics of innate resistance in M. fortis to S. japonicum infection were existed with no significant difference between WMF and BMF.

Animals↗

PubMed1999

[Preliminary study on the immune response in C57BL/6 mice vaccinated by nucleic acid encoding paramyosin of Chinese S. japonicum].

OBJECTIVE: To study the characteristics of immune response in C57 BL/6 mice by nucleic acid encoding full-length paramyosin of Chinese S. japonicum. METHODS: Total RNA was isolated from adult Chinese S. japonicum using TRIzol reagent. The full-length cDNA encoding paramyosin of Chinese S. japonicum was amplified by RT-PCR and cloned into expression vector pcDNA/Amp (pCMV-SjC97), which was intramuscularly injected into C57 BL/6 mice. The mice were vaccinated with DNA the three-week interval for a total of three inoculations. The specific anti-SjC97 IgM, IgG and IgE antibodies and IgG subclasses were determined by ELISA test. RESULTS: The pCMV-SjC97 vaccine induced specific anti-SjC97 IgM and IgG antibodies. The antibody response correlated well with the administered amount of pCMV-SjC97. The IgG subclasses, predominantly IgG2a and IgG2b, were observed in the mice vaccinated with pCMV-SjC97, but no IgG1 and IgG3 responses were seen. CONCLUSION: The strong immune response, especially Th1 type, can be induced in the mice with pCMV-SjC97 vaccine.

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

Length of protection by murine vaccination with living infective third-stage hookworm larvae.

OBJECTIVE: To determine the length of protection by murine immunization with living third-stage hookworm larvae (L3) as measured by reduction in worm burden and host serologic antibody responses. METHODS: Outbred male (Kunming strain) mice were immunized subcutaneously with 500 L3 once every 2 weeks for a total of immunization for 3 times, and then challenged orally with 1000 L3 for 1 to 8 weeks after the final immunization. Host protective immunity was determined both by the reduction in worm burden as measured by the number of L3 recovered from murine lungs 48-hour post-challenge, as well as by measurement of circulating antibodies. Histopathological responses were also examined. Non-immunized mice served as negative controls. RESULTS: The protection by L3 immunization declined over time. One or 2 weeks after the final immunization, worm burdens were reduced 72% and 77.5% after challenge respectively. In contrast, only 37% reduction in worm burden was observed when the L3 challenge was delayed by 4 weeks and protection was almost entirely lost when there was an 8 week delay between the time of final immunization and challenge. The reduced level of protection over time partially correlated with diminishing L3-specific antibody responses. Host inflammation in the lungs of immunized mice also diminished. CONCLUSION: The protection afforded by living L3 immunization is maximal for the first two weeks after immunization, but then declines significantly over the ensuing weeks.

Ancylostoma↗

PubMed1999

[The clinical analysis and review of literature of pulmonary carcinosarcoma and blastoma].

OBJECTIVE: To explore the clinical characteristics, diagnosis, treatment of pulmonary carcinosarcoma and blastoma. METHODS: Summarizing retrospectively 15 cases of pulmonary carcinosarcoma and 2 cases of pulmonary blastoma from January 1979 to November 1998, and reviewing literature to analyse their histologic, clinical feature, diagnosis and treatment. RESULTS: Pulmonary carcinosarcoma and blastoma both were found to be rare malignant tumors, and both epithelial and mesenchymal elements can be seen under the microscopy with different characteristic features. It was hard to be diagnosed before operation. The main symptoms of pulmonary carcinosarcoma were cough, expectoration, sometimes bloody phlegm. X-ray showed that peripheral type were most common, and 2-5 cm in size, well-distributed in density, some showed central or eccentric cavities whose wall was irregular. The margin of the focuses were clear, leafy, the distensive lymph nodes of hilum or mediastium could also be seen. Bronchoscopic examination revealed the bronchial cavity was obstructed by mass or became stricted. Local biopsy can found squamous, adenocarcinoma or large cell carcinoma, respectively. Malignant cell can also be found in sputum. So it was easy to be confused with lung cancer. 14 cases of the carcinosarcoma were treated surgically and diagnosed, 1 case was diagnosed by lymph node biopsy. The symptoms of pulmonary blastoma were fever and hemoptysis. X-ray or CT scan showed an isolated mass in the lung, with uneven density. Malignant cells in pleural effusion were found in one case and can not be diagnosed definetely but by pulmonary puncture. The another case was diagnosed by surgical operation. 15 cases of this group were followed up, in which 4 cases are still alive (including 1 case of pulmonary blastoma), the 1-year survival of carcinosarcoma is 30% (3/10), 2-year survival 20% (2/10), in which 1 case survived more than 6 years. Another pulmonary blastoma case only survived 3 months. CONCLUSIONS: These 2 kinds of malignant tumor are often easy to be misdiagnosed, and prognosis is very poor. Surgical resection is the main method of diagnosis and treatment.

Adult↗

PubMed1999

[Clinical observation and experimental study on treatment of malignant tumor with bailong tablet].

OBJECTIVE: To observe the clinical efficacy of treating moderate and advanced malignant tumors with the compound Chinese herbal medicine, Bailong tablet (BLT) and to explore its mechanism. METHODS: Therapeutic effect of BLT in treating 34 cancer patients was analyzed according to the criteria of therapeutic effect for solid tumor, and changes on their living quality and immune function were observed clinically. In the experimental studies, the effect of BLT on human lymphocyte, celiac macrophage of mice and human gastric cancer cells in vitro were observed. RESULTS: The total remission rate was 11.8%, the remission-stationary rate was 82.3%, the living quality improved and immune function of organism enhanced, the difference between before and after treatment was significant (P < 0.05 or P < 0.01). Experimental study revealed that comparing with the control group, BLT can induce the activated human lymphocyte to kill target cell, promote the proliferation of T-lymphocyte, activate the phagocytosis of celiac macrophage in vitro(P < 0.05 or P < 0.01). CONCLUSIONS: BLT has definite therapeutic effect for moderate and advanced cancer, its anti-tumor effect was related to a series of cell biologic mechanisms, such as the immune function enhancement, T-lymphocyte proliferation and macrophage activation.

Adenocarcinoma, Mucinous↗

PubMed1999

[A methodological study on the evaluation of insulin resistance in vivo].

OBJECTIVE: To investigate the advantage and disadvantage of several methods often used to evaluate insulin resistance and to attempt to modify the disadvantage. METHODS: Three protocols of minimal model technique (MMT), three protocols of basal state approach and four protocols of oral glucose tolerance test (OGTT) were used respectively to calculate insulin sensitivity index (ISI) in 16 subjects with normal glucose tolerance (NGT) and 13 patients with non-insulin-dependent diabetes mellitus (NIDDM). ISI of classical MMT was regarded as standard; ISI of other protocols were analyzed, assessed and compared with that of classical MMT. RESULTS: Except the ISI expressed by the ratio of fasting serum glucose to insulin concentration (FSG/FIns) and the ratio between area under curve (AUC) of glucose and insulin (AUCg/AUCi) in OGTT, ISI of other protocols was significantly higher in NGT group than in NIDDM group (P < 0.05, ISI relative values were 1 and 0.44 - 0.70 respectively) and had stronger relationships as compared with ISI of classical MMT (r = 0.45 - 0.92, P < 0.05). CONCLUSION: The modifications that reduce the samples to 12 or 10 and shorten the time to 120 min for MMT are feasible. Both the homeostasis model assessment and the basal state method designed by LI Guangwei are very simple; they can roughly evaluate insulin sensitivity. OGTT designed by Cederholm is a relatively simple and precise method of measuring IR. Two protocols of OGTT designed by the authors may be accurate methods for evaluating IR. Both FSG/FIns and AUCg/AUCi can not reliably evaluate insulin sensitivity.

Adult↗

PubMed1999

[The protective effects of thalidomide on acute liver failure].

OBJECTIVE: To understand whether thalidomide (Thal) has the same protective effects as it does in leprosy reaction type II, immunologic and inflammatory diseases. METHODS: D-Galactosamine (D-GalN, 600 mg/kg body weight, intraperitoneally) and lipopolysaccharide (LPS, 5 microg/rat, hypodermically) were used to produce a model of acute liver failure in Wistar rats. The mortality of the models was counted. The plasma peak levels of various cytokines and transaminases were measured. The pathological alterations of the livers were examined with hematoxylin and eosin stain under light microscopy. The expression of tumor necrosis factor (TNF)alpha mRNA was determined by dot blot hybridization combined with semiquantitative analysis. RESULTS: It was found that Thal could lower the mortality of the models (P < 0.05); reduce the peak levels of plasma cytokines, especially TNFalpha, and transaminases (P < 0.05), alleviate the degree of liver injury and suppress the expression of TNFalpha mRNA (P < 0.05). CONCLUSION: It is fully demonstrated that Thal has definite protective effect on acute liver failure, as it does in other diseases. Even though Thal possesses teratogenic effect in patients with pregnancy, it is still believed that Thal has an important curative significance in the treatment of patients who are not pregnant.

Animals↗

PubMed1999

[Effect of hypoxia on proliferation and differentiation of the pulmonary vascular pericytes].

OBJECTIVE: To study the effect of hypoxia on proliferation and differentiation of the pulmonary vascular pericytes (PC). METHODS: Cell culture, (3)H-thymidine incorporation ((3)H-TdR), immunocytochemistry and image analysis methods were used. RESULTS: It was found that the (3)H-thymidine incorporation, the expression amounts of proliferating cell nuclear antigen (PCNA) and alpha-smooth muscle actin (alpha-SM-Actin) in direct hypoxia (H) group was 2.16 times (P < 0.01), 1.16 times(P < 0.01) and 1.11 times (P < 0.05) that of normoxia (N) group, in hypoxic endothelial cell conditioned medium (HECCM) group was 1.8 times (P < 0.01), 1.15 times (P < 0.01) and 1.12 times (P < 0.05) that of normoxic endothelial cell conditioned medium (NECCM) group. CONCLUSIONS: It was suggested that hypoxia can stimulate pulmonary artery endothelial cells (PAEC) to secrete some growth factors to enhance PC proliferation and transformation of smooth muscle-like cells.

Actins↗

PubMed1999

[Malignant pheochromocytoma: diagnosis and treatment].

OBJECTIVE: To review the experience with the diagnosis and treatment of malignant pheochromocytoma. METHODS: Between 1986 and 1996, 7 patients with malignant pheochromocytoma were analysed. RESULTS: Compared with benign pheochromocytoma of adrenal gland, the malignant one usually exceeded 7.0 cm in diameter, irregular in shape, invading the surrounding tissue and the normal structure of the effected adrenal gland disappeared. Bleeding and necrotic area were seen in tumor mass, even seemed as a cystic lesion with thick wall. In some patients, blood catecholamine and urine VMA significantly elevated without hypertension. The separating phenomenon and progressive weight loss, accelerated ESR were characteristics of malignant pheochromocytoma. CONCLUSIONS: In some patients with malignant pheochromocytoma, histological findings are not consistent with their biological behaviors. Follow-up studies is mandatory in malignant pheochromocytoma as well as in benign one. Recurrence and/or metastasis after operation often occur in patients with malignant pheochromocytoma. In addition to early diagnosis and surgery, radiotherapy of tumor bed and systematic chemotherapy should be emphasized.

Adrenal Gland Neoplasms↗

PubMed1999

[Transcatheter arterial embolization of renal carcinoma with absolute ethanol].

OBJECTIVE: To study transcatheter arterial embolization (TAE) of renal carcinoma using absolute ethanol so as to reduce bleeding for a higher resection rate, as a palliative treatment for advanced renal carcinoma. METHODS: Using Seldinger method, we treated 25 cases of renal carcinoma with transcatheter arterial embolization. RESULTS: The average bleeding of 25 cases during nephrectomy was 210ml after TAE. There was no mortality and serious complication. But there was pain and fever in most cases. CONCLUSIONS: TAE with absolute ethanol is an effective, safe and easy procedure. It could be used as an adjuvant therapy for renal carcinoma.

Adult↗

PubMed1999

[Prevention of postoperative recurrence of bladder cancer: a clinical study].

OBJECTIVE: To lower postoperative recurrence rate of bladder cancer, the prophylactic effects of five kinds of method on bladder cancer were evaluated. METHODS: Between 1982 and 1997, 313 patients after TURBT or partial cystectomy were followed up for 2 to 15 years (average 7.6 years). These patients were divided into six groups: BCG, mitomycin C (MMC), thiotepa, Chinese herb medicine Zhuling (Grifola umbellata pilat), afterloading brachytherapy and control group. The prophylactic effects of them on postoperative recurrence of bladder cancer was evaluated. RESULTS: During the follow-up, the recurrence rates were 35.1% in BCG group, 34.9% in Zhuling group, 41.7% in MMC group, 52.6% in thiotepa group, 64.7% in control group, respectively. 25 high-risk patients with invading or multiple bladder cancer were treated by afterloading brachytherapy. They were followed up from 12 to 42 months, with a recurrence rate being 24.0%. CONCLUSIONS: The prophylactic effect of Zhuling and BCG on bladder cancer recurrence was better than MMC. The vale of thiotepa was not significant. The afterloading brachytherapy was of great vale to invading or recurrent, multiple bladder cancer.

Adult↗

PubMed1999

[Cervical spinal cord injury treated by expanded hemilaminectomy].

OBJECTIVE: To treat cervical spinal cord injury (SCI) accompanied with narrowing spinal canal by expanded hemilaminectomy. METHODS: From 1995 January to 1998 April 51 patients of cervical SCI were treated by expanded hemilaminectomy. Spinal injury classified in to 3 types: no fracture-dislocation (39 patients) fracture dislocation at the lower cervical spine (11), and burst fracture (1). The types of SCI included central cord injury (18 patients) incomplete cord injury (19), and complete cord injury (14). MR imaging in 23 patients showed degenerative changes with normal intensity of the cord in 14 patients, multiple level hyperintensity in 3, cystic changes in 3, myelomalasia in 3, and cord brocken in 1. Expanded hemilaminectomy was performed in 24 hours in 3 patients, in 48 hours in 9, in one week in 2, after one week in 35, and after one year in 2. The left or right laminae were removed from C(7) to C(3) in 42 patients, C(3) - T(1) in 3, C(2) - C(7) in 2, C(3) - C(6) in 3 and C(4) - C(7) in 3. Hemilaminectomy was expanded lateral to the inner of apophyseal joint and medial to the inner lamina beneath the spinal process. RESULTS: Follow-up lasted for 1 year and 7 months. Six patients with complete cord injury had of the no recovery lower extremity but recovery of the brachialis and extensor radial longus. 12 patients of central cord injury had full recovery except intrinsic muscles of the hand (5). They operated were on 2 weeks after injury. 17 patients of incomplete cord injury recovered to Frankel IV. CONCLUSIONS: Expanded hemilaminectomy is indicated for patients of cervical SCI with narrowing spinal canal or without fracture dislocation. Best results can be obtained in patients of central cord injury, and incomplete cord injury. Even in complete cord injury, 1 - 2 forearm muscle may recover (24.8%), securing a pinch grip reconstruction.

Adult↗

PubMed1999

[Retreatment after excimer laser photorefractive keratectomy].

OBJECTIVE: To evaluate the efficacy and safety of reoperation of residual myopia because of regression, undercorrection with or without coexisting severe corneal haze after excimer laser photorefractive keratectomy (PRK). METHODS: A VISK 20/20 excimer laser was used to treat myopia of -1.00 to -16.50 diopters (spherical equivalent) at corneal plane. 35 patients (51 eyes) who had residual myopia because of regression, undercorrection with or without coexisting severe corneal haze after initial PRK were retreated by using PRK and phototherapeutic keratectomy. RESULTS: At 12 months after retreatment, the rates of uncorrected visual acuity more than or equal to 10/20 or 20/20 were 82.6% and 39.1% respectively, 100.0% and 50.0% in myopia up to -6.00 D, 73.3% and 33.3% in myopia of -6.25 to -16.50 D respectively. 86.3% of eyes were within +/- 1.00 diopters of desired emmetropia. Corneal haze after retreatment was not greater than that observed after initial procedures. CONCLUSIONS: The residual myopia because of regression, undercorrection with or without severe corneal haze after initial PRK can be successfully retreated. Although the therapeutic result of retreatment of PRK is less successful than that of the initial procedure, retreatment appears to enhance it.

Adult↗