Biomedical subjects

M Li

Publications and source records attributed to M Li.

At least 541 records · Page 30Linked to original sources

PubMed1999

Experimental study of growth of trabecular cells on the filters and hydraulic conductivity.

OBJECTIVES: To search the method of culturing human trabecular cells (HTC) on a filter support so as to provide a model to study the hydraulic conductivity of HTC in vivo. METHODS: The third passage of HTC was cultured on a nylon filter; after that we measured the rate of different irrigations through the filter with HTC [Lp, microliter/(min.mm Hg.cm2)]. RESULTS: HTC could continuously grow on the filters. The normal Lp was 10.45 microliters/(min.mm Hg.cm2). Irrigated by the solution of epinephrine (EPI) or dexamethasone (DEX), Lp of HTC were higher than that in controls of the same cultural time, while after being exposed to DEX for a few days, Lp was significantly decreased. CONCLUSIONS: (1) More information of hydraulic conductivity and effects of pharmacologic agents on HTC could be got from the dynamic filtery model; (2) EPI could improve the conductivity of HTC while DEX could have the same effect in early period.

Aqueous Humor↗

PubMed1999

[Inhibition of mesangial cell proliferation and mesangial matrix expansion by antisense oligodeoxynucleotide targeting preproendothelin-1 mRNA in vivo].

OBJECTIVE: To investigate the effect of endothelin-1 (ET-1) on mesangial cells(MC) proliferation and mesangial matrix expansion in vivo. METHODS: Antisense oligodeoxynucleotide(As-ODN) and its control sequences, sense oligodeoxynucleotide(Se-ODN) and mismatch oligodeoxynucleotide(Mis-ODN), targeting pre-proendothelin-1 mRNA (ppET-1) were delivered into the kidney of rats with mesangioproliferative glomerulonephritis (MsPGN) model respectively at day 2 by lipofectin-mediated gene transfer method. The efficiency of transfer of ODNs into MC was examined with biotinylated As-ODN staining. Four days after the rats were sacrificed, the influence of ODNs on ET-1 production by glomeruli was tested with radioimmunoassay(RIA). The action of ODNs on MC proliferation and mesangial matrix expansion was evaluated with quantitative pathologic analysis. RESULTS: ODNs were transferred into MC in vivo. The glomerular ET-1 production was decreased by As-ODN [(32 +/- 19) ng/g, P < 0.05] with reduction of mesangial cell proliferation [(0.82 +/- 0.04)/100 micron 2, P < 0.05] and mesangial matrix expansion[(12.8 +/- 1.6)%, P < 0.05], where Se-ODN and Mis-ODN did not show any effect on all of these. CONCLUSIONS: Specific inhibition of ET-1 gene expression leads to reduction of proliferation of mesangial cell and expansion of mesangial matrix in rats with MsPGN model. ET-1 is one of the important inflammatory mediators which can stimulate MC proliferation and mesangial matrix expansion in vivo.

Animals↗

PubMed1999

[The value of 99mTc-sulfer colloid bone marrow scintigraphy in differential diagnosis of aplastic anemia].

OBJECTIVE: To diagnose equivocal aplastic anemia(AA) patients by the combination of clinical data and bone marrow scintigraphy. METHODS: Bone marrow scintigraphy using 99mTc-sulfer colloid 370-550 MBq was analysed in 47 patients, including 28 cases of AA, 12 of myelodysplastic syndromes(10 MDS-RA and 2 MDS-RAEB) and 7 of AA-PNH syndrome. RESULTS: Pancytopenia, hypercellular bone marrow associated with uneven disappearance of marrow image or focal hematopoiesis were found in 28 AA and 2 of 30 MDS-RA cases. Marrow imaging showed uneven low accumulation of radioactivity in 12 and focal patterns in 18 patients. Normal or high activity and expanded periphery of bone marrow was found in MDS patients (8 RA and 2 RAEB cases). Changes of activity and distribution of bone marrow during the transforming course were noticed in 4 AA-PNH syndrome patients. CONCLUSIONS: Patch distribution and focal hemopoiesis is the outstanding features of AA marrow. The imaging features as well as expanded manner and increased activity of bone marrow are helpful to the differential diagnosis, evaluation of clinical status and explanation of marrow aspirate results.

Adolescent↗

PubMed1999

A recombinant multi-epitope, multi-stage malaria vaccine candidate expressed in Escherichia coli.

OBJECTIVE: To construct and evaluate a recombinant multi-epitope, multistage malaria vaccine candidate expressed in Escherichia coli (E. coli). METHODS: A hybrid gene (HGF) encoding several putative immunodominant T or T/B epitopes from MSP-1, MSP-2, Pf155/RESA of Plasmodium falciparum (P. falciparum) and two immune-stimulating epitopes from interleukin-1 and tetanus toxin was synthesized. Two copies of HGF and a copy of gene encoding Pattaroyo's Spf66 were connected together to construct a sandwich hybrid gene HGFSP. The gene was cloned into an expression vector pWR450-I for production of a fusion protein with beta-galactosidase. Efficacy of this vaccine candidate in inducing specific immunity against malaria parasites was evaluated. RESULTS: Immunization of different species of animals with purified recombinant peptide showed that the peptide was able to induce remarkable antibody response to the immunized peptide as well as falciparum malaria parasites. The epitopes included in the construct could induce antibodies against the intact parasite proteins as demonstrated by western blotting, indicating the epitopes retained their antigenicity in the new peptide construct. Antibodies from animals immunized with recombinant HGFSP peptide exhibited good ability in inhibition of the in vitro growth of malaria parasites, augmentation of phagocytosis of the parasites or infected RBC by phagocytes, and facilitation of antibody dependent cell mediated cytotoxicity to the cultured malaria parasites. CONCLUSION: The recombinant peptide seems to be a potential candidate which is valuable for further investigation.

Animals↗

PubMed1999

Inhibition of mesangial cell proliferation by antisense oligodeoxynucleotide targeting preproendothelin-1 mRNA in vitro.

OBJECTIVE: To investigate the effects of endothelin-1 (ET-1) on mesangial cell proliferation in vitro. METHODS: Antisense oligodeoxynucleotide (As-ODN) and its control sequences, sense (Se-ODN) and mismatch (Mis-ODN) oligodeoxynucleotides, targeting preproendothelin-1 (ppET-1) mRNA were delivered into cultured human mesangial cells (HMC) with lipofectin-mediated gene transfer method. The cytotoxicity of lipofectin was determined with lactate dehydrogenase (LDH) release assay. The efficiency of ODNs transfer into HMC was examined with biotinylated As-ODN staining. The effect of As-ODN on expression of ppET-1 mRNA was analyzed with semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The action of As-ODN on HMC ET-1 secretion was tested by radioimmunoassay (RIA). The influence of As-ODN on HMC proliferation was evaluated with MTT method. RESULTS: As-ODN was transferred into HMC with lipofectin without any impairment of cell viability. The ppET-1 mRNA expression, the ET-1 secretion and the cell proliferation were inhibited by As-ODN transferred into HMC, while Se-ODN and Mis-ODN transferred into HMC did not show any effects on all of these. CONCLUSION: Decrease of ET-1 secretion by HMC, caused by the down-regulation of ppET-1 mRNA expression after As-ODN transfer, led to inhibition of HMC proliferation. These results suggest ET-1 is one of the autocrine growth factors of HMC, and may play an important role in the pathogenesis of proliferative glomerulonephritis.

Cell Division↗

PubMed1999

[Collagen-binding proteins of human oral spirochetes].

OBJECTIVE: To evaluate pathogenic effect of the collagen-binding proteins(CBP) of human oral spirochetes. METHODS: Immunoblot analysis, immunoelectron microscopy and other experiments had been used. RESULTS: It was showed that: type I, IV and V CBP were detected in heated and unheated preparations from Treponema denticola(Td) ATCC 33520 and Treponema socranskii (Ts) ATCC 35534. Few CBP, however, were detected in heated and unheated preparations from a recently characterized isloate, Treponema medium(Tm) strain G7201. 27,000 type V CBP of Td, 110,000 type I of Ts and 95,000 type IV of Tm were located on the envelopes of the individual cells. The adherence of Td to the collagen-coated surface was significantly greater than that of Tm. CONCLUSION: The CBP on the oral spirochetal cells play an important role in their adherence to collagen-rich connective tissues of the host.

Bacterial Adhesion↗

PubMed1999

[Experimental study on protective effect of Chinese herbal medicine on glucocorticoid receptor].

OBJECTIVE: To probe the relationship of glucocorticoid receptor and some Chinese medicinal herbs. METHODS: The models of Qi-Yang exhaustion and Qi-Yin exhaustion were made with hemorrhagic rats and heat-stressed rats respectively. The effect of Shenfu Decoction (SFD) and Shengmai Powder (SMP) on plasma glucocorticoid (GC) and its receptor (GcR) in hepatic cytosol of the models were measured respectively. RESULTS: The activity of GcR decreased in both models, while their blood level of GC increased markedly. SFD and SMP showed no regulating effect on blood GC, but displayed obvious up-regulation on GcR level in both models. CONCLUSION: SFD and SMP could up-regulate the activity of GcR in Qi-Yang and Qi-Yin exhaustion models.

Animals↗

PubMed1999

[Clinical study on hyperthyroidism of yang hyperactivity type due to yin deficiency treated by jiakang ning capsule].

OBJECTIVE: To investigate the effect of Jiakang Ning (JKN) capsule on hyperthyroidism. METHODS: Eighty-five cases of hyperthyroidism were divided into JKN group (24 cases), JKN with low dose Tapazol group (35 cases) and Tapazol control group (26 cases) at random. The effects were evaluated by total effective rate, using principal symptoms, body weight, EKG, thyroid hormone and atrial natriuretic peptide (ANP) after 6 months. RESULTS: The total effective rates of three groups were 83.8%, 97.1%, 88.5% respectively, and there were insignificant difference among them statistically (P > 0.05). The first two groups had better effect in principal symptoms than Tapazol control group (P < 0.05). There were similar results in adjusting thyroid dysfunction and abnormal EKG, decreasing ANP and increasing body weight among those three groups (P > 0.05). CONCLUSION: The effect on hyperthyroidism treatment by JKN capsule was satisfactory. The combination of Chinese herbs with western medicine could enhance the curative effect of hyperthyroidism without obvious side-effects.

Adolescent↗

PubMed1999

[The mediation effects of endothelin-1 on human mesangial cell proliferation stimulated by thrombin].

OBJECTIVE: To investigate the effects of endothelin-1 (ET-1) on mesangial cell proliferation stimulated by thrombin. METHODS: With cultured human mesangial cells (HMC), the following tests were performed. (1) Stimulative tests: After thrombin stimulation, HMC proliferation was determined by MTT method, concentration of ET-1 in supernatant was measured with radioimmunoassay (RIA) and preproendothelin-1 (ppET-1) mRNA expression of HMC was analysed by Northern blot hybridization. (2) Inhibitory test: The influence of ET-1 inhibitors on the HMC proliferation following thrombin stimulation at three different levels, i.e. ET-1 antiserum, selective ET receptor-type A (ET(A)) antagonist and antisense oligodeoxynucleotide for ppET-1, was measured by MTT test respectively. RESULTS: (1) HMC proliferation was stimulated by thrombin in dose dependent manner and in relation to the time of stimulation. The peak growth level was attained in thrombin concentration of 16 U/ml and incubation time of 16 hours. ET-1 secretion by HMC was increased in parallel with the dose curve and time curve of HMC proliferation; HMC ppET-1 mRNA expression was up-regulated by thrombin 16 U/ml with incubation time of 8 hours and 16 hours respectively (7.9 fold, 3.4 fold versus control group). (2) ET-1 inhibitors, ET-1 antiserum, selective ET(A) receptor antagonist and antisense oligodeoxynucleotide for ppET-1 all significantly inhibit HMC proliferation stimulated by thrombin. CONCLUSION: Thrombin stimulates HMC to produce ET-1 and ET-1 mediates the HMC proliferation.

Cell Proliferation↗

PubMed1999

[Limited pleuro-pneumonectomy for bronchogenic carcinoma associated with cancerous pleural effusion].

OBJECTIVE: To evaluate the effects of limited pleuro-pneumonectomy for bronchogenic carcinoma associated with cancerous pleural effusion. METHODS: From January. 1994 to December 1997 we performed limited pulmonary lobectomy wedge resection of lung, resection of the metastases of the parietal pleura, visceral pleura, diaphragmatic pleura and pericardiac pleura, and electro incision of the micormetastases of the above position as well as cleaning the mediastinal lymph nodes in 14 cases. RESULTS: The 14 cases were followed-up to December 1998. Eight patients of them died, the other 6 patients survived with a survival period of 7 - 30 months (median survival period 16.5 months). No pleural effusions recurrence was seen. The longest survival period was 30 months. There were no operative mortality and no severe postoperative complication. Chest distress, dyspnea and pain of chest or abdomen were relieved. CONCLUSIONS: This simple method has such advantages as, less traumatic, rapid rehabilitation and effective control of pleural effusion. The postoperative survival period is longer than that of palliative operation and medical therapy. The pain caused by parietal pleural metastasis can be relieved.

Adenocarcinoma↗

PubMed1999

[Refractory carotid-cavernous fistula: causes and countermeasures].

OBJECTIVE: To explore the causes and countermeasures of refractory carotid-cavernous fistula (CCF). METHODS: Twelve refractory cases from 123 cases of consecutive traumatic CCF during 12 years were reviewed. RESULTS: The main causes of refractory CCF were: small or large fistula's opening, or constrictive parent artery; inappropriate early treatments such as ligature of internal carotid artery or common carotid artery, balloon detachment of, and non-dense packing of coils inside the cavernous sinus; unexpected deflation or balloon displacement of resulting in fistula recurrence. Anatomical cure was achieved in 11 cases, and clinical care in 1 by using balloon or/and coil or/and NBCA (n-butal 2-cyanoacrylate) through arterial, venous or surgical approach. CONCLUSIONS: refractory CCF can be treated effectively skilled catheterization and embolization as well as appropriate approach and embolic material according to fistula structure and vascular route.

Adolescent↗

PubMed1999

[Influence of transforming growth factor-beta1 on actin in cultured human trabecular cells].

OBJECTIVE: To understand transforming growth factor-beta(1) (TFG-beta(1)) influencing microfilament actins in cultured human trabecular cells (HTCs) and approach to the effect of resistance of aqueous outflow in the pathogenesis and mechanism of primary open angle glaucoma (POAG). METHODS: Trabecular meshwork was collected from 68 eyeballs of 34 human donors under 6 years old within 24 hours after death. HTCs were primarily cultured and subcultured. Cultured cells were observed by light and electron microscopes. Laminin (LN) and IVcollagen (IVC) in extracellular matrix (ECM) were immunohistochemically stained by S-P method. Various doses (0, 1, 5 ng/ml) of TFG-beta(1) and 30 microg/ml neutralizing antibody of TFG-beta(1) were respectively added to the third passage cells before confluence and acted for 6, 12, 24 hours. Stress fibers stained with fluorescein isocyanate (FITC)-phalloidin were observed under light and electron microscopes. Various doses (0, 0.5, 1, 5 ng/ml) of TFG-beta(1) and 30 microg/ml neutralizing antibody of TFG-beta(1) were respectively added to the third passage cells after confluence for one week and acted for 6, 12, 24, 48 hours. The positive numbers of labeled F-actins were quantitatively evaluated by flow cytometry. Various doses (0, 0.5, 1, 5 ng/ml) of TFG-beta(1) and 30 microg/ml neutralizing antibody of TFG-beta(1) were respectively added to the third passage cells after confluence for one week and acted for 6, 12, 24, 36, 48 hours. The amount of beta-actin mRNA expression was semi-quantitatively evaluated by densitometry with reverse transcription-polymerase chain reaction (RT-PCR) using specific oligonucleotide primers for beta-actin and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) as an internal standard. RESULTS: According to the growing characteristics and morphological features of the cultured cells, they were identified as HTCs. In comparison with the control group, TGF-beta(1) could increase the stress fibrous bundle, the contents of F-actins and the expression of beta-actin mRNA; the effects of TFG-beta(1) appeared time dependent and were antagonized by neutralizing antibody of TFG-beta(1). When TFG-beta(1) was at higher concentration and longer acting time, cell proliferation was inhibited, cell membrane ruptured and cells peeled off in cultured HTCs before confluence. CONCLUSIONS: Application of reverse transcription-semiquantitative PCR can promote the pathogenic research of POAG at genetic level, in a certain extent, TFG-beta(1) can obviously upregulate microfilament actins in the confluent HTCs, enhance the contractility of trabecular cells and decrease the resistance of aqueous outflow in trabecular meshwork.

Actin Cytoskeleton↗

PubMed1999

[Influence of cell growth factors on transferrin gene expression of human lens epithelial cells in culture].

OBJECTIVE: To assess the influence of transforming growth factor-beta(1) (TGF-beta(1)) and basic fibroblast growth factor (bFGF) on the transferrin mRNA levels of cultured human lens epithelial cells. METHODS: Lens anterior capsules were collected from 40 eyeballs of 20 human donors under 3 years of age within 24 hours after death. Lens epithelial cells were primarily cultured and subcultured. TGF-beta(1) (1 microg/L) and bFGF (250 microg/L) were added to the 3rd passage cells when they became confluent after their growth for 2 weeks. The total cellular RNA was extracted from cultured cells by guanidine isothiocyanate, etc. after the growth factors acting for 3 days. Transferrin mRNA levels were determined by a Northern blot analysis with a probe. RESULTS: In comparison with the control group, the expressions of transferrin in the growth factor treatment groups were obviously increased. In comparison with bFGF group, transferrin mRNA level in TGF-beta(1) group was obviously increased. CONCLUSIONS: TGF-beta(1) and bFGF upregulate transferrin gene expression of cultured lens epithelial cells remarkably, can reduce lenticular oxidative damaging process in which transferrin participates and play an important role in the pathological mechanism of cataract formation after extracapsular cataract extraction.

Cells, Cultured↗

PubMed1999

[Transforming growth factor-beta1 induced cultured human trabecular cells to produce elastin].

OBJECTIVE: To understand transforming growth factor-beta(1) (TGF-beta(1)) inducing cultured human trabecular cells (HTCs) to produce elastin and to approach the effect of resistance of aqueous outflow in the pathogenesis and mechanism of primary open angle glaucoma (POAG). METHODS: Trabecular meshwork's specimens were collected from twelve normal eyeballs of six human donors under six years of age within 24 hours after death. HTCs were primarily cultured and subcultured. Cultured cells were observed under light and electron microscopes. Laminin (LN) and IV collagen (IV C) in extracellular matrix (ECM) were immunohistochemically stained by S-P method. The third passage confluent cells after two weeks were divided into three groups: control group, TGF-beta(1) group and neutralizing antibody of TGF-beta(1) group. Concentration of neutralizing antibody of TGF-beta(1) was 30 microg/ml. After culturing for two weeks, elastin in the media of three groups was respectively determined by western blotting from sodium dodecylsulfate-polyacrylamide gel electrophoresis using anti-human aortic alpha-elastin rabbit serum, biotin conjugated goat anti-rabbit IgG and anti-biotin conjugated horse radish peroxidase. RESULTS: Cultured HTCs were identified from cultured cell's growing characteristics, morphological features under light and electron microscopes, and stained peculiarities of LN and IV C in ECM. With western blotting, elastin in the control group was not detected, elastin in TGF-beta(1) group was detected, and elastin in neutralizing antibody of TGF-beta(1) group was not detected. CONCLUSION: TGF-beta(1) induces cultured HTCs to produce elastin, which the neutralizing antibody of elastin can antagonize; the increase of the amount of elastin may aggravate its stacking in ECM and increase the resistance of aqueous outflow in trabecular meshwork, leading to the occurrence of glaucoma.

Cells, Cultured↗

PubMed1999

[Magnetic resonance imaging in 40 cases of optic neuritis].

OBJECTIVE: To explore the clinical value of magnetic resonance imaging (MRI) in optic neuritis. METHODS: Forty patients with optic neuritis were examined with the spectral presaturation inversion recovery and fluid attenuated inversion recovery. RESULTS: The lesion was frequently seen in orbital portion (86.7%) and intracanalicular portion (29.3%), and primarily in the axial part (49.3%) and transverse section (38.7%) of the optic nerve. The longitudinal extent of lesion was from 2 to 35 mm (mean, 12.6 mm), the visual acuity of patients with optic neuritis was related to the site of the lesion, and negatively correlated with the longitudinal extent of lesion of logarithm curve. A poor visual acuity (< 0.01) was significantly associated with lesion of greater extent > 10 mm and the transverse or axial lesion, but the good visual acuity (>or= 0.3), with the lesion of smaller extent < 10 mm and the axial or peripheral lesion. In addition, paramagnetic contrast-medium, Gd-DTPA, enhancement scanning was carried out in 11 cases of optic neuritis, of them the visual acuity was increased in 10 cases after administration of corticosteroid, and in one case, visual improvement was not seen. CONCLUSION: MRI is a new and useful equipment which is helpful in the diagnosis and treatment of optic neuritis.

Adolescent↗

PubMed1999

[Significance of telomerase activity detection by fine-needle aspiration in patients with breast cancer].

OBJECTIVE: To study the telomerase activity in samples of breast fine-needle-aspiration specimens and to investigate its potential clinical implications. METHODS: Ninety nine fine-needle aspiration specimens from 83 patients with breast cancers, 12 with benign lesions and 4 with breast inflammation, were studied for the presence of telomerase activity by a PCR-based telomere repeat amplification protocol (PCR-TRAP). RESULTS: Among 83 fine-needle aspiration specimens from patients with breast cancer, telomerase activity was detected in 61 of 69 cytologic-positive specimens, 5 of 7 cytologic-suspicious specimens and 4 of 7 cytologic-negative specimens. Sensitivity of telomerase activity detection was 84.3% (70/83); the coincidence rate between telomerase detection and cytologic confirmation was 77.1% (64/83). Of 12 specimens from patients with benign breast lesions, 4 were positive for telomerase activity, but 4 specimens from patients with breast inflammation were all negative. The Combined use of cytological and telomerase detection can improve the detection rates from 83.1% (69/83) to 93.9% (78/83). CONCLUSION: Detection of telomerase in breast tissue samples by fine-needle aspiration is a sensitive and specific method, which implies that it would be helpful in preoperative cytological diagnosis of breast cancer.

Biopsy, Needle↗

PubMed1999

[Determination of total scopoletin in Caulis Erycibes by RP-HPLC].

OBJECTIVE: To accumulate data for quality control of Caulis Erycibes. METHOD: The total-scopoletin in Caulis Erycibes was determined by RP-HPLC, using CLC-ODS1 column, 0.5% glacial acetic acid in methanol-water(26:55) as mobile phase and UV detector at 310 nm. RESULT: The average recovery is 99.37% and RSD 0.39%. CONCLUSION: Determination data have been obtained for fourteen batches of three species, and the contents of scopoletin should be no less than 30 mg/100 g.

Chromatography, High Pressure Liquid↗

PubMed1999

[Electrocardiographic T-wave amplitude of normal population and its correlation with age, sex and race].

OBJECTIVE: To establish a normal electrocardiographic T wave amplitude standard in Chinese population according to age and sex. METHODS: The electrocardiographic T wave amplitudes in 4,322 persons among normal population; aged from birth to eighty-five years old divided into 11 age-groups, were analyzed. The 97.5th percentile(P97.5) and 2.5th percentile(P2.5) were considered as the upper and the lower limit of normal T wave amplitudes and T/R ratio. Wilcoxon rank sum test was used to determine whether the normal electrocardiographic T wave amplitude and the T/R ratio were different in P97.5 value versus mean + 1.96 s value, in men versus women, and in Chinese versus Americans. The linear correlation analysis was used to examine the association between normal T amplitude and age as well as between T/R ratio and age. RESULTS: The normal T wave amplitudes and T/R ratio in all leads were greater in P97.5 value than in mean + 1.96 s value and were greater in men than in women. The normal T wave amplitudes of adults were greater in Chinese than in Americans except V1 lead in which the amplitudes were greater in Americans than in Chinese. There was moderate or marked correlation of normal T wave amplitude and T/R ratio with age in most of the leads. CONCLUSION: There are marked differences of age, sex and race in normal electrocardiographic T wave amplitudes.

Adolescent↗