Biomedical subjects

H Liu

Publications and source records attributed to H Liu.

At least 307 records · Page 17Linked to original sources

PubMed2001

[A clinical analysis of 102 cases of chronic n-hexane intoxication].

OBJECTIVE: Chronic n-hexane exposure can result in n-hexane intoxication which is mainly characterized by a series of manifestations of peripheral nerve lesions. The disease was sometimes misdiagnosed as "unknown multiple peripheral neuropathy". 102 cases of n-hexane intoxication were investigated and reported in order to call attention to the disease. METHODS: All the 102 cases, male 30, female 72; age 17 - 29, mean (21 +/- 3) were n-hexane workers. During the hospitalization the following data were collected: medical history, neurological check up, electromyogram, electrocardiogram, serum biochemical analysis, ophthalmologic study and the metabolite of n-hexane- the urinary 2, 5-hexanedione level. The airborne n-hexane levels of the working environment were also measured. RESULTS: The average incubation period of the 102 cases was (8.3 +/- 2.6) months. The average course of the disease was (12.1 +/- 4.2) months. Airborne n-hexane concentration of the working places ranged from 188.0 to 7,848.6 mg/m(3). The most common prodromes were headache, anorexia, dizziness and weight loss. The main clinical manifestations of the disease were ascending abnormal sensation. Sensory loss and dyskinesia began from the distant parts of the limbs. The patient had reduction or disappearance of tendon reflexes, weakness and muscle atrophy in the limbs. Electromyography showed a neuropathic pattern, which was parallel to the clinical symptoms and signs. Delayed worsening of symptoms and signs after cessation of n-hexane exposure was observed in some cases. All the 102 cases recovered totally after treatment with Vitamin B, Chinese traditional medicine, physical therapy and training. CONCLUSION: The main lesion of the disease is multiple peripheral neuropathy. Diagnosis should be made according to the history of n-hexane exposure, the typical clinical manifestations of peripheral neuropathy as well as the neuropathic changes on electromyography. Therapeutic measures for peripheral neuropathy of other etiologies may be used and the prognosis is optimistic if correct diagnosis is made and further exposure stopped.

Adolescent↗

PubMed2001

[Changes of crop yields and soil fertility under long-term application of fertilizer and recycled nutrients in manure on a black soil].

The results from a field experiment over thirteen years on a black soil in Northeast China indicated that nitrogen fertilizer increased crop yields by 724 kg.hm-2 per year on average, with an increase rate of 27.5% and about 9.4 kg increased yield from 1 kg applied N. In the early stage, the crop yields almost gave no response to phosphorus fertilizer, owing to the high level of soil available phosphorus at the beginning of the experiment. The average increase of crop yields by phosphorus in thirteen years was only 241 kg.hm-2 per year, with an increase rate of 7%, about 12.7 kg increased yield from 1 kg applied P. Annual application of recycled pig manure made by 80% of harvested grain fed to pigs and the stolks as bedding materials could increase crop yields by 268, 258 and 255 kg.hm-2 per year with an increase rate of 9.8%, 7.6% and 7.0%, based on no fertilizer, with N and with P and N, respectively. There was a trend that the effect of recycled manure on crop yield was gradually increased during the period of experiment, implying the existence of accumulative residual effect from the manure.

Agriculture↗

PubMed2001

[Combined construction of rainwater catchment techniques with methane pool and greenhouse].

A combined structure of rainwater catchment, methane pool and reformed greenhouse was constructed to improve water use efficiency. The results showed that the combination of rainwater catchment, reserving techniques and water saving measures was efficient to resolve the problem of water deficiency in the semi-arid region with precipitation of 250-550 mm. The combined structure of water catchment engineering, greenhouse and methane pool redistributed light, temperature, water and heat to develop higher benefits economic crops, and improved water use efficiency, which made it possible to develop high yield, and best quality agriculture in this region. Through optimizing the ecological factor in greenhouse, the water use was reduced by 50%-70%, and the soil temperature and night temperature were raised. This combined construction also improved productivity in greenhouse, and efficiently controlled plant diseases and insect pests. Methane pool provided CO2 and part energy source. The shady area back of the greenhouse was exploited by growing shady crops and epiphyte, which contributed to exchange energy and CO2 between light and shady house. This model could be used as water catchment agricultural development model in the region, and some other new approaches to water catchment agriculture in semi-arid region were discussed in this paper.

Agriculture↗

PubMed2001

Evaluating the UMLS as a source of lexical knowledge for medical language processing.

Medical language processing (MLP) systems rely on specialized lexicons in order to recognize, classify, and normalize medical terminology, and the performance of an MLP system is dependent on the coverage and quality of such lexicons. However, the acquisition of lexical knowledge is expensive and time-consuming. The UMLS is a comprehensive resource that can be used to acquire lexical knowledge needed for medical language processing. This paper describes methods that use these resources to automatically create lexical entries and generate two lexicons. The first lexicon was created primarily using the UMLS, whereas the second was created by supplementing the lexicon of an existing MLP system called MedLEE with entries based on the UMLS. We subsequently carried out a study, which is the primary focus of this paper, using MedLEE with each of the two lexicons and also the current MedLEE lexicon to measure performance. Overall accuracy, sensitivity, and specificity using the lexicon primarily based on the UMLS were.86,.60, and.96 respectively. Those measures using the MedLEE lexicon alone were.93,.81, and.93, which was significantly better except for specificity; performance using the supplemental lexicon was exactly the same as performance using solely the MedLEE lexicon.

Natural Language Processing↗

PubMed2001

A study of abbreviations in the UMLS.

Abbreviations are widely used in medicine. The understanding of abbreviations is important for medical language processing and information retrieval systems. The Unified Medical Language System (UMLS) contains a large number of abbreviations. We hypothesized that extracting and studying the UMLS abbreviations can be helpful for understanding the characteristics of abbreviations in medicine. In this paper, we describe a method for extracting abbreviations from the UMLS. We evaluated the method and studied the ambiguous nature of the abbreviations. In addition, the coverage of the UMLS abbreviations in medical reports was studied. Using our method, we extracted 163,666 unique (abbreviation, full form) pairs from the UMLS with a precision of 97.5%, and a recall of 96%. The UMLS abbreviations were highly ambiguous: 33.1% of abbreviations with six characters or less had multiple meanings; the average number of different full forms for all abbreviations with six characters or less was 2.28. The coverage of the UMLS abbreviations in medical reports was over 66%.

Abbreviations as Topic↗

PubMed2001

[The effectiveness of cyclosporin A in the treatment of autoimmune hemolytic anemia and Evans syndrome].

OBJECTIVE: To test the therapeutic effectiveness of cyclosporin A (CsA) in combination with corticosteroid in the treatment of autoimmune hemolytic anemia(AIHA) and Evans syndrome. METHODS: Forty-four cases of AIHA and Evans syndrome were treated with CsA in combination with a conventional regimen (prednisone + danazol) (18 cases) or conventional regimen alone(26 cases). RESULTS: The complete response rate of CsA group (88.9%) was higher than that of conventional regimen group (57.7%) (P < 0.05), and the relapse rate was lower (3.3% vs 70%) (P < 0.01). CONCLUSION: CsA in combination with conventional regimen can improve the complete response rate and reduce relapse of AIHA and Evans syndrome.

Adolescent↗

PubMed2001

[Autotrophic denitrification of groundwater by electrochemical process].

An autotrophic denitrification process and its reactor for removing nitrate from groundwater was investigated in this paper. Using activated carbon fiber(ACF) as electrodes, the electrochemical reactions could produce hydrogen as the donor for autotrophic denitrification. In the process, nitrate was removed effectively and no accumulation of nitrite in the effluent. The results in this study proved that some key factors, such as the applied current density, flow rate of water, oxidation-reduction potential and the nitrate concentration in raw water, influenced the electrochemically denitrifying effect. When the concentration of NO3(-)-N was 28.8 mg/L in inlet water, the optimum applied density was 9 mA, the highest hydraulic load of the reactor was 35 ml/h, and the reactor performed a practical buffering capacity to pH. After applying electricity to the reactor for 1 h, the oxidation-reduction potential decreased to below--200 mA, so an adaptable reductive environment could be provided in the reactor for denitrification.

Carbon↗

PubMed2001

[Attitude to voluntary HIV testing and result disclosure among rural residents in China].

OBJECTIVE: To identify the determinants of individual acceptance of voluntary HIV testing and the scope of test results disclosure. METHODS: A cross-sectional study was performed to interview 1 057 subjects aged 15 - 49. RESULTS: Among 653 subjects who had heard of HIV/AIDS, 575 (88.1%) reported willingness to be tested for HIV infection. Of subjects who would accept the offer, 90.2% agreed to disclose testing results to their spouse, 77.1% to other family member, 54.8% to their friends and 50.8% to their neighbors. Logistic regression analysis indicated that the acceptability was associated with being a man, and having better knowledge in HIV/AIDS. CONCLUSIONS: The level of acceptability of voluntary HIV testing is high among people who know about HIV/AIDS. Given the large number of people in rural China who never heard of HIV/AIDS, it is important to carry out information-oriented education activities to increase AIDS awareness among rural residents.

Adult↗

PubMed2001

[Prevalence survey on pterygium in two counties of Hainan Province].

OBJECTIVE: To explore the relationship between pterygium and environmental condition, such as area and weather, and human factors, such as sex and race, through the prevalence survey of pterygium in Hainan Province. METHODS: As a sample, all villagers in 14 villages were chosen by random sampling from all the rural villages of Dongfang and Changjiang Counties, the pterygium was examined and their pterygia were recorded and graded according to the shape and the location of the head of pterygium. RESULTS: In 7 990 villagers examined, there were 628 cases with pterygium, prevalence being 7.86% and including 439 cases (8.28%) in 5 303 Han people and 189 cases (7.03%) in 2 687 Li people. The difference of the prevalence between Han and Li nationality was significant (chi(2) = 3.897, P = 0.048). There were 266 male cases (6.43%) and 362 female cases (9.40%). The prevalence in male was less than that in female (chi(2) = 19.852, P = 0.001). The distribution of the pterygium in eyes was symmetrical. CONCLUSION: The prevalence of pterygium in Hainan is higher than that in other provinces of China. It may be related to the geographic location and weather condition. In Hainan Province, the prevalence of pterygium in Han nationality is higher than that in Li nationality and in female higher than that in male. The increase of the prevalence of pterygium may be related to the increase of age.

Adolescent↗

PubMed2001

[Regulation of c-myc expression in leukemic cell line Meg-01 by the death domain of Fas gene].

OBJECTIVE: To investigate the mechanism of disordered proliferation of leukemic cells and the proliferation inhibition by the Fas death domain (FASDD) in human leukemia cell line Meg-01. METHODS: The chimerical receptors (Fas/190, Fas/130) were constructed by Fas cytoplasmic domain with the leukemic inhibitory factor (LIF) receptor subunits gp190 and gp130, another chimerical receptor was constructed by replacing the gp130 in Fas/130 with Fas death domain (FAS/130f). The chimerical receptors were separately expressed on the membrane of Meg-01, and activated with anti-Fas antibodies to induce the oligomerics of the cytoplasmic regions (190cyt-190cyt-190cyt, 130cyt-130cyt-130cyt or FASDD-FASDD-FASDD) for initiating the intracellular signal transduction. c-myc expression level was assayed by means of immunoblotting and immunobiochemistry. RESULTS: Increased c-myc expression and cell proliferation were observed in the group of Fas/130 as compared with the other two groups. CONCLUSION: The cytoplasmic domain of gp130 might involve the induction of c-myc expression and the cell proliferation of Meg-01 cell. The Fas death domain may be a medium in the apoptosis induction against the effect of gp130.

Cell Line, Tumor↗

PubMed2001

[Immunorelated pancytopenia].

OBJECTIVE: A report of a group of patients with pancytopenia which might be related to abnormal immunity. METHODS: The clinical and laboratory features of 29 patients with positive bone marrow mononuclear cell (BMMNC) Coombs tests were analyzed. RESULTS: Most of these cases were pancytopenia with normal or decreased bone marrow cellularities and increased normoblasts. They were all found to have negative results of conventional hemolysis tests and hematopoietic nutrient determination and had no evidence of malignant clonal hematopoiesis. However, all of them showed positive BMMNC-Coombs test and good response to corticosteroids. CONCLUSION: Immunorelated pancytopenia might be caused by abnormal immunity (especially autoantibody) mediated destruction or abnormal function of blood cells. It is beneficial to differentiate immunorelated pancytopenia from aplastic anemia or myelodysplastic syndromes.

Adolescent↗

PubMed2001

[Sequential intensified immunosuppressive therapy combining with hematopoietic growth factors in the treatment of severe aplastic anemia].

OBJECTIVE: To explore more effective regimen for reducing early mortality of severe aplastic anemia (SAA) and improving therapeutic effectiveness. METHODS: Antilymphocyte globulin/antithymocyte globulin (ALG/ATG) and cyclosporine A (CsA) (sequential intensified immunosuppressive therapy, SIIST), with or without hematopoietic growth factors (HGFs) were administered to 73 SAA patients in a prospective randomized clinical trial to test the effectiveness of the addition of HGFs for the patients. RESULTS: The response rate of SIIST with HGFs group was significantly higher than that of SIIST alone group (89.2% vs 63.9%), with lower rates of early infection (24.3% vs 55.3%) and mortality (4.0% vs 16.7%), shorter duration of cytopenia and blood transfusion dependence and faster recovery of bone marrow hematopoiesis. The addition of HGFs to SIIST was tolerated well in all patients. There was no difference in the treatment outcome of the two groups with GM-CSF plus Epo or G-CSF plus Epo. CONCLUSION: The use of HGFs in combination with SIIST could reduce early infection and mortality rates and, therefore, improve the response rates in SAA patients.

Adolescent↗

PubMed2001

[The mutation of anti-CD3 antibody (HIT3a) gene and its expression].

OBJECTIVE: To improve the expression of anti-CD(3) single chain Fv (scFv) by site mutation and identify its biological activity. METHODS: Anti-CD(3) scFv gene was mutated by PCR, the target clones were screened by both the fingerprints of DNA restriction endonuclease digestion and Western blot, the antigen-binding activity of scFv was examined by FACS, competitive inhibition was performed with (125)I-labeled HIT3a and the cytotoxic effect mediated by the anti-CD(3) scFv-activated T lymphocytes was analyzed by (51)Cr-released assays. RESULTS: The DNA sequencing showed that the 6th amino acid of the anti-CD(3) antibody (HIT3a) heavy chain gene was mutated from E (GAG) to Q (CAG). The expression of mutated anti-CD(3) scFv (m2) was increased by 100 times higher than that of the parent scFv, and there was no difference in the Jurkat cell (CD(3)(+))-binding activity between the (m2) and parent scFv. The preliminary results of competitive assays showed that m2 could partially block the sites of CD(3)(+) Jurkat cells where the parent antibody bound to. Cytotoxicity assays demonstrated that CD(3)AK cells induced by IL-2 and m2 showed stronger cytotoxic effect than that of LAK cells induced by IL-2 alone in vitro. CONCLUSION: By site mutation, a high expression fragment m2 of anti-CD(3) scFv antibody was obtained. The results of some experiments indicated that m2 could bind to CD(3)(+) Jurkat cells, furthermore, by co-stimulated with IL-2, it could activate peripheral T lymphocytes and induce CD(3)AK cytotoxic effect.

CD3 Complex↗

PubMed2001

[Study on the transformation from myelodysplastic syndromes into acute leukemias].

OBJECTIVE: To study the patterns of transformation from myelodysplastic syndromes (MDS) into acute leukemias (AL). METHODS: Leukemic transformation of MDS patients was dynamically followed up and the clinical manifestations, peripheral blood and bone marrow pictures, karyotypes, immunophenotypes, response to treatment and prognosis of post MDS acute leukemia (postMDS-AL) were observed. RESULTS: During the past eight year and seven months, 21 (13.91%) of 151 MDS patients progressed to overt leukemia with a median interval of 5 (1 - 21) months. There were no significant differences among the rates of leukemia from RA, RAEB and RAEB-t groups. The transformation was developed either gradually or rapidly. There were five parameters related to the leukemic transformation: under 40 years of age, pancytopenia, more than 0.15 blasts in bone marrow, at least two types of abnormal karyotype and combined chemotherapy. All of the 21 post MDS-AL were acute myeloid leukemia (AML); and most of them were M(2), M(4) and M(5). Two (9.52%) post MDS-AML developed extramedullary infiltration. Leukopenia was found in 47.62% of patients. Two third of the patients, whose bone marrows were generally hypercellular, showed neutropenias. After evolving into AML, 8 (47.06%) patients developed abnormal karyotypes. High expression of immature myeloid antigens, including CD(33) (49.83 +/- 24.50)%, CD(13) (36.38 +/- 33.84)%, monocytic antigen CD(14) (38.50 +/- 24.60)%, and stem cell marker CD(34) (34.67 +/- 30.59)% were found on bone marrow mononuclear cells of post MDS-AML cases. In some cases, lymphoid antigens, such as CD(5), CD(7), CD(9) and CD(19) were coexisted with myeloid antigens. A low complete remission rate (31.25%) and short survival duration with median survival of 6 (1 - 28) months were found in patients with post MDS-AML treated by induction therapy. CONCLUSION: MDS was at high risk of evolving into AML, either gradually or rapidly. Patients with post MDS-AML had specific biologic features and worse prognoses.

Acute Disease↗

PubMed2001

[Study of specific targeting cytotoxicity mediated by anti-CD(3)/anti-CD(20) Diabody].

OBJECTIVE: To study the specific targeting cytotoxicity mediated by an anti-CD(3)/anti-CD(20) diabody. METHODS: The diabody was purified by affinity chromatography and identified by Western blot assay, size exclusion chromatography, FACS and rosetting assay; the effect of the anti-CD(3)/anti-CD(20) diabody mediated lysis of CD(20)-expressing tumor cells was assayed by (51)Cr release assay in vitro and by human B cell tumor nude mice xenograft model in vivo. RESULTS: The anti-CD(3)/anti-CD(20) diabody could bind both Jurkat cells (CD(3)(+)) and Daudi cells (CD(20)(+)) and appeared to be potent in targeting activated peripheral blood mononuclear cell (PBMC) to lyse Daudi cells in vitro. Furthermore, it inhibited tumor growth and prolonged the survival of mice bearing xenografted Raji cells. CONCLUSION: The diabody proved to be a potent agent for targeting peripheral blood lymphocytes to lyse CD(20) antigen expressing tumor cells in vitro and in vivo.

Animals↗

PubMed2001

[Comparison of mortality rates between peritoneal dialysis and hemodialysis in diabetic nephropathy patients].

OBJECTIVE: To evaluate and compare the different survival rates and clinical outcome of continuous ambulatory peritoneal dialysis (PD) and hemodialysis (HD) treatment in diabetic patients. METHODS: 62 diabetic patients suffering from end stage renal complication were treated with PD or HD. The age, sex and residual renal function of the two groups were matching. Their survival rates and levels of blood lipid, blood sugar, serum albumin and hemoglobin were observed. RESULTS: The mortality rates of HD and PD were not significantly different in the first two years. But mortality of PD increased rapidly after two years of treatment. The levels of blood triglycerides, low density lipoprotein cholesterol and fasting sugar in PD patients were higher than that in HD patients, while the concentration of serum albumin was lower than HD patients significantly. CONCLUSIONS: In diabetic patients with renal failure PD as a choice to replace the kidney function was not superior to HD, especially after two years of PD treatment. A close watch is necessary to detect the change of parameter levels mentioned above and if is better to shift to HD. A strict long-term and extensive survey is needed to compare these two methods further.

Aged↗

PubMed2001

[Influence of a triplex superimposed treatment on HBV replication and mutation during treating chronic hepatitis B].

OBJECTIVE: To observe and evaluate the influence of a new antiviral treatment scheme on HBV replication and mutation during treating chronic hepatitis B. METHODS: In the test group, lamivudine, IFN alpha-2b, Astragalus membranaceus were chosen as a triplex superimposed treatment scheme for treating the patients who were on the state of HBV high replication and involved in the clinical condition of chronic hepatitis B. The control group was treated with lamivudine alone. The observed parameters percentage of patients in whom HBV DNA became undetectable (serum HBV DNA<1.6 ng/L), HBeAg/anti-HBe seroconversion rate; HBV DNA serum level; HBV YMDD mutation rate and pre-C region mutation rate. RESULTS: Compared with that of the control group, HBV DNA undetectable rate of the test group increased markedly at weeks 12, 36, 48(P <0.05), HBeAg negative rate of the group increased markedly at week 36, 48(P <0.05), while anti-HBe positive rate increased only at week 48 (31.58 vs.19.23%, P <0.05). After 4 weeks of treatment, HBV DNA serum level of both the test group and the control group reduced very remarkably (P <0.01), and at week 48, reduced more significantly (P <0.001). Compared with the control group, HBV DNA serum level of the test group reduced notably at week 12 (P <0.05) and very notable at week 36 and 48(P <0.01). At week 12, the pre-C region mutation occurred in the test group, and at week 24, 36,48, the pre-C region and YMDD mutations occurred in both the test group and the control group. CONCLUSIONS: As to anti-viral treatment of chronic hepatitis B, the triplex superimposed treatment had better efficacy than lamivudine alone.

Adolescent↗

PubMed2001

Optimizing brain tumor resection. High-field interventional MR imaging.

High-field strength iMRI guidance is an effective tool for brain tumor resection. Although its use lengthens the average time for a craniotomy, the reward is a more extensive tumor excision compared with conventional neurosurgery without an increased risk to the patient (Table 4). Although intraoperative patient transfer into and out of the magnet is cumbersome, the possibility for complete resection, especially for a low-grade glioma, makes the effort worthwhile. The cost and technical support required for this system presently limits its use to only a few sites worldwide. As with any technology, further refinements will make this system less expensive and more attainable. Practical consideration aside, high-field strength iMRI is presently [table: see text] the most effective tool available for brain tumor resection. Because of its novelty, future studies are necessary to determine if this technology lowers the incidence of and extends the duration to tumor recurrence as the preliminary data in children suggests. These are the ultimate measures of efficacy for any brain tumor treatment. Based on the rapid advancement of technology, will today's high-field strength interventional magnet become tomorrow's low-field system? Very high-field strength designs may improve diagnostic capabilities through higher resolution, but their interventional applications may be hindered by increased sensitivity for clinically insignificant abnormalities and decreased specificity for clinically relevant lesions. As new technology is developed, clinicians must continue to explore and refine the existing high-field strength iMRI to make it cost-effective and widely applicable.

Adolescent↗