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Biomedical subjects

F Li

Publications and source records attributed to F Li.

At least 487 records · Page 27Linked to original sources
PubMed1996

[Effect of tetrandrine on intraacinar pulmonary arterial structural remodelling and pulmonary hypertension].

Rat's pulmonary hypertension was induced by a single subcutaneous injection of monocrotaline. The influences of tetrandrine (Tet) upon the structure of intraacinar pulmonary arteries (IAPA) was studied by light and electron microscopy. The results indicated that Tet reduced the thickness of IAPA medial membrane, the ratio of the thickness of IAPA medial membrane to the diameter of IAPA, the number of circular muscular artery and partially muscular artery about 16.4%, 30.5%, 24.3% and 16.4% respectively, and Tet increased the number of nonmuscular artery about 24.7%. It also decreased the degeneration of IAPA, collagen of medial membrane, prolife-ration and myoid differentiation of the pericyte, and it increased the number of IAPA. The authors discussed why Tet caused such changes.

Alkaloids↗
PubMed1996

[The analysis of abnormal auditory brainstem responses].

The abnormal auditory brainstem responses (ABR) of 56 cases who had different retrocochlear disorders were analysed. These disease included acoustic neuroma, glioma, cholesteatoma, astrocytoma, meningoma in cerebellopontile angle (CPA), chromaffin tumor of jugular foramen, intracranial metastatic tumor, demyelinating disease, multiple cranial nerve paralysis, hepatolenticular degeneration, other CPA tumors, expansion or stenosis of internal auditory meatus (IAM), and so on. The ABR features were varied in these diseases, even in same disease. In general, the wave latencies and interwave periods prolonged in the disorders which occupied place in CPA, the differentiation of wave was not clear and/or the wave was not well repeated in the disorders which spreaded all over the brain. The cause of abnormal ABRin which CT and/or MRI were normal was also analysed. The ABR detection is a sensitive indication in retrocochlear lesions.

Cerebellar Neoplasms↗
PubMed1996

[Clinical study on induction of labor with feedback pulsatile oxytocin system].

OBJECTIVE: To improve the safety and the effect on induction of labor with oxytocin. METHOD: 112 cases were selected for labor induction with feedback pulsatile oxytocin under the monitoring of uterine contraction controller (study group). 112 cases were selected with continuous intravenous infusion of oxytocin as a control (control group). The dose of oxytocin and the pulse time-point were adjusted. The effects of labor induction in the 2 groups were compared. RESULTS: The most suitable time-point was 1.5 minute after the uterine contraction. The best administration duration was 20 seconds. But the most suitable dose varied individually, generally 12-25 mU. The mean time to establish contraction in study group was significantly shorter (1.9 +/- 1.2 min) than that of the control group (115.5 +/- 72.3 min, P < 0.001). The average dose of oxytocin administered per hour was significantly less in the study group (312 +/- 64 mU) than that of the control group (735 +/- 125 mU, P < 0.001) the success rate was 100% in study group whereas only 90.2% in control group (P < 0.01). The total duration of labor in the study group was 6.9 +/- 4.7 hours in contrast to 20.4 +/- 10.9 hours in the control group (P < 0.001). The occurrences of dystocia, postpartum hemorrhage and neonatal asphyxia were lower in study group. CONCLUSION: This study proved that the administration of oxytocin with the feedback pulsatile oxytocin system is easier to establish the effective uterine contraction, and it is a more physiologic and effective regimen for induction of labor.

Adult↗
PubMed1996

[Therapeutic effect of trace element on ulcerative colitis experimental study].

OBJECTIVE: To produce a chronic UC model in rats, and study the therapeutic effects of trace elements on this UC model as well as the in possible mechanisms. METHODS: Male Wistar rats (100-150 g) were given drinking water containing 1.5% dextran sulfate sodium (DSS) to induced UC. Rats developed UC were divided into 4 groups randomly, selenium group (Se group, Natural Selenium Liquid 6 ml.d-1, containing selenium 60 micrograms); zinc plus selenium group (ZS group, every rat was given zinc sulfate 180 mg.kg-1.d-1 and selenium 60 micrograms.d-1), while dexamethasone (7 mg.kg-1.d-1) was used as positive control and 0.9% NS as placebo control. All rats received enema twice a day for 15 days. Endoscopic and histologic scoring were carried out for assessment of the therapeutic effect of trace elements. Mucosal SOD activity, MDA content, zinc and selenium content and peripheral blood NK activity were assessed. RESULTS: The efficacy of ZS group was better than that of placebo control (P < 0.01), and there was no difference between ZS group and positive control (P > 0.05). An increased SOD activity and decreased MDA content were found after the combined administration of zinc and selenium. Zinc and selenium concentration of colonial mucosal were increased significantly, so did the NK activity of peripheral blood. CONCLUSION: The combined therapy of zinc and selenium is effective for UC treatment, of which the possible mechanism may be involved, A) concentrating in local mucus; B) acting as scavengers of oxygen-free radicals, protecting cell membrane from peroxidation; C) improving the function of immunosurveillance system.

Animals↗
PubMed1996

[A comparative study of benign and malignant pulmonary masses with coloured Doppler sonography].

In order to differentiate benign from malignant pulmonary masses by means of observing blood flow signal, with coloured Doppler sonography, the authors examined 67 in-patients who had been found having masses in the lungs by X-ray or CT. For comparison 43 benign cases showing blood signals in the lung was also examined. The results showed that the blood flow signals of all lung cancers were of relatively low blood flow resistance or arteriovenous shunting, while those of benign lesions were of high blood flow resistance. The pulsatility index in lung cancer was 1.02 +/- 0.30, the restance index was 0.52 +/- 0.13, the peak systolic velocity was 0.19 +/- 0.11 m/s, the end diastolic velocity was 0.06 +/- 0.02 m/s. The pulsatility index in benign pulmonary lesions was 1.53 +/- 0.30, the resitance index was 0.86 +/- 0.05, the peak systolic velocity was 0.28 +/- 0.05 m/s and the end diastolic velocity was 0.04 +/- 0.01 m/s. There were significant differences between the benign and malignant pulmonary lesions in the four indices (P < 0.01) by t test and t' test. Lower pulsatility index, lower resistance index, lower peak systolic velocity and higher end diastolic velocity were characteristics of malignancy.

Adult↗
PubMed1996

Effects of dynorphin A (1-17) on motor function and spinal intracellular messenger systems in rat.

The effect of intrathecal injection of dynorphin A (1-17) on second messenger systems of spinal cord relative to behavioral change in rats was studied. Dynorphin A (1-17) 5, 10 (20 nmol) caused dose-dependent flaccid paralysis of hindlimbs. Dynorphin A (1-17) 10, 20 nmol dose-dependently decreased spinal adenylate cyclase (AC) activity, cyclic AMP production, calmodulin (CaM) level and cyclic-nucleotide phosphodiesterase (PDE) activity 10 min after intrathecal injection. They recovered to a varying extent two hours later. Pretreatment with selective kappa-opioid receptor antagonist nor-BNI 30 nmol 10 min before dynorphin A (1-17) markedly antagonized the effects of dynorphin A (1-17) at 20 nmol on hindlimb paralysis and inhibition of intracellular second messengers. The L-type calcium channel blocker verapamil (100 nmol) also played a role in blocking dynorphin neurotoxicity. The NMDA receptor antagonist APV could partially or completely block dynorphin inhibition of CaM level and PDE activity without affecting paralysis and decrease of AC-cAMP level induced by dynorphin A (1-17) 10 min after intrathecal injection.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1996

[The effect of nifedipine on the microcirculation in pregnancy-induced hypertension].

OBJECTIVES: To study the effects of nifedipine on the microcirculation in pregnancy-induced hypertension (PIH). METHODS: We observed the microcirculation in nailfold of 30 normal pregnant women and 76 cases of PIH. 20 mg nifedipine was given and nailfold microcirculation was observed after 30 minutes. RESULTS: Nifedipine increased the velocity of blood flow, reduced the aggregation of erythrocytes, and dilated capillaries. After the administration of nifedipine, the total score of the nailfold microcirculation decreased significantly in mild and moderate PIH (P < 0.05), but no marked difference was observed in severe PIH cases (P > 0.05). CONCLUSION: The disorder of the microcirculation of PIH can be improved by nifedipine.

Adult↗
PubMed1996

[A cohort study on the relationship between standardized mortality of pulmonary heart disease and smoking].

We explored the relationship between the standardized mortality of pulmonary heart disease (PHD) and smoking at Shifang county through a five-year follow-up study of 29,498 farmers over 35 years old. The death ratio of PHD was 30.35%, which stood first in all causes of death. The mortality of PHD for cigar/cigarette smokers regardless of sex was not significantly different from that for nonsmokers (P > 0.05). The RR was 1 or so. The analysis of data stratified by age showed that the specific mortality increased with age in spite of some inequalities smoking; the RR of PHD for cigar/cigarette smokers in all age groups were 1 or so revealing no significant differences (P > 0.05). However, the standardized mortality of PHD increased with the accumulated amount of smoking. The relationship between the mortality of PHD and short-term smoking with small dose was not significant (P > 0.05), but when the accumulated amount reached certain level, i.e. the smoker consumed cigar more than 270 kg or consumed cigarette more than 20,000 packs, the relationship between the behavior of cigar/cigarette smoking and the mortality of PHD became apparent. The RRs were 1.40-3.94 and the ARs 171-1610 per 100,000 person years (P < 0.05-0.01).

Adult↗
PubMed1996

[The relationship of non-Hodgkin's lymphoma with P16 protein expression].

The expression of P16 protein was examined in 45 cases of non-Hodgkin's lymphoma (NHL), 4 cases of reactive hyperplasia of lymph node (RHLN) and 6 cases of normal spleen with immunohistochemical staining. Positive reaction of P16 protein was observed in some lymphocytes of RHLN and splenic nodule and around splenic sinus. The positive rate of P16 protein expression in NHL was 37.8% (17/45). The positive rates of P16 protein expression for the low intermadiate- and high-grade malignancy groups were 66.7% (10/15), 37.5% (6/16) and 7.1% (1/14) respectively. There was a significant difference between the low malignancy NHL and the high malignancy NHL (P < 0.005) in expression rate of P16 protein. It suggests that P16 protein expression may be one of the important parameters in estimating the prognosis of patients with NHL.

Adolescent↗
PubMed1996

[T-cell receptor gene rearrangement analysis of midline malignant reticulosis: a PCR study of 14 cases].

Using PCR method, we analyzed the gene rearrangement of T-cell receptor chain (TCR-beta) in 14 cases of midline malignant reticulosis (MMR). Our results showed that there were non-germline, monoclonal rearrangements of TCR-beta in 12 of 14 cases of MMR (85.7%). In contrast, the same rearrangement pattern was found only in 6 of 10 cases of lymph node based T-cell lymphoma. The cases of reactive lymphoid hyperplasia were of a polyclonal rearrangement pattern. This study suggests that MMR is a monoclonal T-cell neoplasm and PCR method is a rapid, facilitated and useful method for the detection of clonalities of T-cell proliferations.

Gene Rearrangement, beta-Chain T-Cell Antigen Rece↗
PubMed1995

Enantioselective determination of oxprenolol and its metabolites in human urine by cyclodextrin-modified capillary zone electrophoresis.

A stereospecific capillary electrophoresis assay for oxprenolol enantiomers and their basic metabolites in human urine has been developed using hydroxypropyl-beta-CD as a chiral selector in the mobile phase. The bioassay method has been validated and the detection limit from spiked urine samples is 0.2 micrograms/ml. The calibration curves are linear from 0.4 to 16 micrograms/ml. Extraction recovery ranged from 84.7 to 96.4% for all the compounds studied. The influence of various parameters on the chiral separation of oxprenolol and its basic metabolites have been investigated. Urinary excretion profiles of oxprenolol enantiomers and those of two metabolites have also been studied, following a single oral dose of racemic oxprenolol.

Calibration↗
PubMed1995

Immunohistochemical investigation of tau-positive structures in the cerebral cortex of patients with progressive supranuclear palsy.

We have investigated tau-positive structures immunohistochemically in the cerebral cortex of patients with progressive supranuclear palsy (PSP). In addition to neurofibrillary tangles, a variety of tau-positive structures occur. They are particularly abundant in the precentral gyrus and other frontal cortices. Double immunostaining has demonstrated that coil-like structures (coiled bodies) are located in the oligodendroglial cell bodies. Three forms of tau-positive astrocytic inclusions are discerned: those with tuft-like profiles, thorn-like structures, and concentric clusters of short stubby fibers. The concentric clusters of tau-positive fibers are present in some, but not all, PSP brains. They appear to be identical to 'astrocytic plaques' previously reported in patients with corticobasal degeneration (CBD). PSP and CBD might share a common pathological background which causes abnormal accumulation of tau protein in neurons and glial cells of neuroectodermal origin.

Aged↗
PubMed1995

Determination of the enantiomers of metoprolol and its major acidic metabolite in human urine by high-performance liquid chromatography with fluorescence detection.

Enantiomers of metoprolol and its acidic metabolite H 117/04 were determined in human urine by high-performance liquid chromatography (HPLC) with fluorometric detection after chiral derivatization. The carboxyl functional group of the major metabolite was blocked by esterification after solid-phase extraction, which helped to quantitate this compound from interfering substances. The assay method was validated. The recovery of (-)- and (+)-metoprolol from urine was 86.3-90.5%; and the recovery of the (-)- and (+)-acidic metabolite H 117/04 from urine was 74.4-83.9% at different concentrations.

Adult↗
PubMed1995

Identification of a 40-kDa human protein that cross-reacts with prokaryotic hsp60/chaperonins.

Cross-reactivity between the immunodominant bacterial hsp60 proteins and heterologous human target proteins has led to numerous hypotheses on the role of hsp60 in the pathogenesis of autoimmune disease. In this work, we describe a novel 40-kDa human protein that cross-reacts with bacterial hsp60 proteins. CCP40 (chaperone cross-reacting protein, 40-kDa) was identified in extracts from HL-60 (human promyelocytic leukemia) cells on Western blots probed with A57-E4, a monoclonal antibody specifying a linear polypeptide epitope common among the bacterial hsp60 proteins (Yuan et. al. (1992) Inf. Immun. 60, 2288-2296). CCP40 was detected in other human hematopoietic cell lines, but could not be detected in mature peripheral blood leukocytes. CCP40 was also expressed in human CD34+ peripheral blood progenitor cells, disappearing with cytokine-induced cellular maturation.

Amino Acid Sequence↗
PubMed1995

Reduced expression of peptide-loaded HLA class I molecules on multiple sclerosis lymphocytes.

Lymphocytes from patients with HLA class II-linked autoimmune diseases such as type I diabetes, systemic lupus erythematosus, rheumatoid arthritis, and Graves' have recently been shown to have a decrease in the expression of self-peptide-filled HLA class I antigens on the surface of peripheral lymphocytes. The human demyelinating diseases of multiple sclerosis in some cases are also associated with the presence of certain HLA class II genes, which may in turn be linked to genes in the class II region that control class I expression. Hence, we studied fresh peripheral blood mononuclear cells (PBMCs) and newly produced Epstein-Barr virus (EBV)-transformed cell lines from multiple sclerosis patients for the class I defect. Unseparated PBMCs, as well as T cells, B cells, and macrophages from multiple sclerosis patients had a decrease in the amount of conformationally correct peptide-filled HLA class I molecules on the cell surface compared with matched controls detectable by flow cytometry. To demonstrate the independence of this defect from exogenous serum factors, newly produced EBV-transformed cell lines from B cells of patients with multiple sclerosis maintained the defect. In addition, DR2 +/+, +/-, and -/- EBV-transformed B cells from these patients similarly demonstrated the self-antigen presentation defect. Analysis of a set of discordant multiple sclerosis twins revealed the class I defect was exclusively found on the affected twin lymphocytes, suggesting a role of this class I complex in disease expression. These data indicate that multiple sclerosis patients have abnormal presentation of self-antigens.(ABSTRACT TRUNCATED AT 250 WORDS)

Gene Expression↗
PubMed1995

Alteration of Chlamydia trachomatis biologic behavior in synovial membranes. Suppression of surface antigen production in reactive arthritis and Reiter's syndrome.

OBJECTIVE: To investigate the biologic state of Chlamydia and its surface antigen expression in the synovial membranes of patients with Chlamydia-associated reactive arthritis/Reiter's syndrome (ReA/RS). METHODS: Expression of chlamydial lipopolysaccharide (LPS), major outer membrane protein (MOMP), and elementary body (EB) antigens was studied by gold labeling immunoelectron microscopy on 6 synovial membrane and 2 synovial fluid (SF) pellet samples from 6 patients with Chlamydia-associated arthritis. The study findings were compared with 24-hour cultures of HeLa cells infected with Chlamydia trachomatis EB. RESULTS: Persistent C trachomatis infection was found in all 6 synovial membrane samples from patients who had either early or chronic arthritis. The infection persisted despite antibiotic treatment, including a 1-month course of doxycycline therapy. Most persistent organisms were atypical reticulate bodies (RBs) found in both fibroblasts and macrophages. Specific, but weak, immunogold staining for all 3 antibodies was found on both intracellular RBs and extracellular EBs. In the SF samples, Chlamydia surface antigens were detected only in phagosomes containing degraded electron-dense materials. CONCLUSION: The synovial membrane biopsies conducted in this study of Chlamydia-associated ReA/RS revealed atypical RBs with diminished MOMP and LPS expression. Such altered organisms may escape immune surveillance and contribute to disease chronicity; moreover, these organisms may be difficult to detect and treat in some ReA/RS patients.

Adult↗