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Biomedical subjects

L Li

Publications and source records attributed to L Li.

At least 1,135 records · Page 63Linked to original sources
PubMed1998

[A model for exercise-induced asthma in guinea pigs with lipopolysaccharide and metyrapone].

OBJECTIVE: To investigate the relationship between airway inflammation and exercise-induced asthma (EIA), an experimental model for EIA in guinea pigs was developed. METHOD: 27 guinea pigs was divided into 4 groups. A) LPS + MET exercise group (n = 7) had been pretreated with lipopolysaccharide (LPS 1 mg/kg, i.p.) and metyrapone (MET 50 mg/kg, i.p.) on the first day. Then lung resistance (RL) and dynamic compliance (Cdyn) were measured before and after exercise on the fourth day. B) LPS + MET non exercise group (n = 6) that pretreated with LPS and MET had nonexercise on the 4th day. C) NS exercise group (n = 7) pretreated with normal saline (NS 1 mg/kg, i.p.) on the 1st day. RL and Cdyn were measured before and after exercise on the 4th day. D) NS nonexercise group (n = 7) that pretreated with NS had no exercise on the 4th day. RESULT: In LPS+MET exercise group RL increased and Cdyn reduced significantly after exercise. In another 3 control groups there were no such changes either in RL or in Cdyn. CONCLUSION: These observations suggest that the treatment with LPS and MET could make a model for exercise-induced asthma.

Airway Resistance↗
PubMed1998

[Determination of vincristini sulfas in tumor cells by high performance liquid chromatography].

Vincristini sulfas (VCR) is an important common antitumor drug. The resistance to anticancer drug is the main cause of the chemotherapy failure. To screen the drugs which can reverse VCR resistance for VCR resistant cell strain, an analytical method has been established for the determination of VCR concentration in tumor cells using high performance liquid chromatography (HPLC). The stainless steel column was 25 cm x 4.6 mm i.d. packed with totally porous, spherical silica particles (5 microns). A solution of methanol and 0.02 mol/L dipotassium hydrogen phosphate (80:20, V/V) adjusted to pH 6.6 with H3PO4 was employed as the mobile phase. The flow rate was 1 mL/min. Chromatography was performed with ultraviolet detector at 267 nm. The method is simple, rapid and selective. Linear calibration curve for VCR was measured within the range of 10 to 200 mg/L with correlation coefficient of 0.999 8. The lowest detection limit was 4 mg/L tumor cells extract. The HPLC method described is suitable for clinical monitoring and pharmacokinetic study of VGR.

Antineoplastic Agents, Phytogenic↗
PubMed1998

[An improved method of cholesterol determination in egg yolk by high performance liquid chromatography].

An improved method for cholesterol determination in egg yolk is reported in this paper. Egg yolk was first diluted. Cholesterol was then extracted with ethyl ether and petroleum ether, and quantified by reversed phase liquid chromatography on a Zorbax ODS column (0.46 mm x 15 cm, 5-6 microns) using a mobile phase of acetonitrile and 2-propanol (4:1) with a flow rate of 0.6 mL/min. A linear correlation was observed between 0.05-0.40 g/L of cholesterol. The determination limit was 0.02 g/L. This proposed method of HPLC determination of egg yolk without saponification is superior to colorimetric determination on the sample with saponification, and comparable to HPLC determination with saponification of the egg yolk sample in terms of reliability. No difference in final results was observed between egg yolk sample with saponification and the same sample without saponification. Rapid and reproducible quantification of cholesterol in egg yolk can be completed with this new method. Omission of saponification has made this proposed method more convenient than those ever reported, and can be used in yolk cholesterol study with greater ease.

Cholesterol↗
PubMed1998

[Neurotoxicity of antibody against motoneuron on cultured rat cortical neurons].

OBJECTIVE: In order to determine the role of antibody against motoneuron in the process of neuronal death. METHODS: Cultured rat cortical neurons growing in serum-free medium, were employed to observe the effects of antibody against motoneuron (anti-SMN) on the survival of these cultured neurons. RESULTS: (1) Exposure of the cultures in serum-free medium to anti-SMN with dilution of 1:50 results in death of 31%-41% of neurons for 24 hours incubation, 50%-67% for 48 hours and above 90% after 72 hours. The neurotoxicity induced by anti-SMN was accompanied by concentration-dependent release of lactate dehydrogenase into the culture medium. Cultures exposed to normal rat IgG as controls exhibited no such sign. (2) The cultured neurons exposed to anti-SMN (1:200) expressed markedly higher levels of immunoreactive Calbindin-D28k especially after 48 hours incubation with it. There was a reduction in the number of acetylcholinesterase-positive neurons compared to the normal control. CONCLUSIONS: The anti-SMN could directly initiate the process of cortical neuronal death and this effect was independent of complement. The alteration of Calbindin-D28k immunoreactivity implied that calcium may be involved in the neurotoxicity induced by anti-SMN.

Acetylcholinesterase↗
PubMed1998

[5 cases report of Kaposi's sarcoma].

OBJECTIVE: To aid clinical diagnosis and management of Kaposi's sarcoma. METHODS: 3 male and 2 female of classical Kaposi's sarcoma were analysed by clinical and pathological examinations. RESULTS: All the patients presented hemorrhagic or flue plagues nodules that could be fused together or ulceration. The lesions could reappear and get relived by themselves, The retroperitoneal lymphnodes was involved in one case, together with hypoxemia, oral ulceration, conjunctivitis and keratitis. The tumor behaved intensive spindle-cell sarcoma with obvious karyokinesis. CONCLUSION: The affected organ in classical kaposi's sarcoma were mainly skin, rarely internal organs. The diagnosis were verified on pathology and the treatment could rely on radiotherapy, chemotherapy and local resection.

Adult↗
PubMed1998

[Expression of IL-1 mRNA and its correlation with astrocytes and NOS-positive neurons in rat spinal cord following sciatic nerve injury].

OBJECTIVE: To study expression of Interleukin 1 (IL-1) and its correlation with astrocytes and nitric-oxide synthase (NOS)-positive neurons in rat spinal cord following sciatic nerve transection. METHODS: Using RT-PCR and immunohistochemistry methods. RESULTS: The experiments showed that IL-1 expression appeared with a low frequency at 3 days after the axontomy, while it could be markedly detectable on post-lesioned day 7 and 14. In normal controls and the spinal fragments without being involved in the injury, no signal of IL-1 mRNA expression was detected with the same condition. At 7 days after nerve injury, the lesioned side of spinal cord began to show strong glial fibrillary acidic protein (GFAP) immunoreactive astrocytes and induction of NOS in the motoneurons that are normally NOS-negative. Up to 21 days after operation, GFAP staining showed star-shaped astrocytes closely resembling the typical appearance of fibrous astrocytes and GFAP-immunoreactive profiles were often seen surrounding NOS-positive neurons. Analysis of the time course of IL-1 mRNA expression, appearance of NOS-positive neurons and changes of reactive astrocytes suggested a close relationship between them. CONCLUSIONS: IL-1, NO might function as important mediators between injured motoneurons and astrocytes.

Animals↗
PubMed1998

[Effect of activities of vagi and sympathetic nervous system on heart rate variability].

Experiments were performed on rabbits anaesthetized with urethane and chloralose. The electrocardiogram (ECG), heart rate (HR), and blood pressure (BP) were recorded and the power spectrum density (PSD) of R-R interval was analysed by a computer. The low frequency component (LF) was higher during the respective stimulation of the nucleus ambiguous, depressor nerve, and the peripheral end of right vagus with a low frequency fluctuant style than with a monotonous style (P < 0.05). Intravenous infusion of phenylephrine resulted in increases of total variance of RRI (TV), very low frequency components (VLF), LF, high frequency components (HF) and LF/HF during the first 256 RRI only (P < 0.05-0.01). In order to observe the influence of different activities of sympathetic nerves on heart rate variability (HRV), DL-homocysteine (DLH) was microinjected into the vicinity of N. Paraventricularis of hypothalamus. This injection caused increases of the TV, LF, LF/HF and VLF during the rising phase of BP and HR, but no significant change occurred at the plateau period of high BP and HR. These results suggest that heart rate variability mainly reflects the fluctuation of vagal and sympathetic tone.

Animals↗
PubMed1998

[Screening of enhancers for permeation of berberine in ruyi patcher in vitro].

To screen the best kinds and doses of enhancers for Ruyi Patcher, the effect of azonc(A) and propanediol (P) on the permeation of berberine(BR) from Ruyi Patcher in vitro was studied using improved Franz diffuse cells and the permeated berberine was determined by HPLC. The result showed that 3% of A in combination with 10% of P had synergistic effect, which helped enhance the skin permeation of BR significantly(P < 0.01). Therefore, a combination of 3% A and 10% P is the best enhancer for Ruyi Patcher and the penetration process of BR could be described by one-order kinetics.

Animals↗
PubMed1998

[Effect of turmeric volatile oil on the respiratory tract].

OBJECTIVE: Researching the effect of turmeric volatile oil on functions of the respiratory tract. METHOD: The action of turmeric volatile oil on sputum removing, cough and asthma relieving was observed by vapour inhaling. RESULT: The volatile oil is significantly active in removing sputum, relieving cough and preventing asthma. CONCLUSION: Turmeric volatile oil may be an efficacious drug for the treatment of respiratory diseases.

Animals↗
PubMed1998

[Anti-oxidative action of the glycosides of Cistanche in the tissue of mice].

OBJECTIVE: To study the anti-oxidative action of GCS in the tissues of mice. METHOD: Contents of superoxide dismutase (SOD), malondialdehyde (MDA) and lipofuscin in the heart, liver, brain and kidney of mice were measured, using pyrogallic acid, thiobarbi turic acid(TBA) and fluorescent technique respectively. RESULT: It was found that the GCS (125 mg/kg, 250 mg/kg) had a significantly higher SOD activity and lower MDA contents in brain and kidney than that in control group. GCS(250 mg/kg) enhanced SOD activity in the heart and liver, declined contents of MDA and lipofuscin in all tissues. CONCLUSION: The results suggest that GCS could increase the antioxidative action in vivo significantly and prevent lipoperoxidative damages in tissues.

Animals↗
PubMed1998

Textual research on Pang Anshi's case record of acupuncture treatment for difficult labor.

Ancient works on women's diseases of successive ages were studied on the question Pang Anshi's acupuncturing the point "Hukou" at the dorsal aspect between the thumb and index finger to cure a case of difficult labor. Query is put forward on the absence of such case report in all those books through deliberated investigation of relevant medical literatures. It is concluded that Pang's case report is convincing and is worthy of attention.

Acupuncture Therapy↗
PubMed1998

[Cellular apoptosis, proliferation and bcl-2 Bax expression in colorectal carcinoma and their association with tumor prognosis].

OBJECTIVE: To investigate the relationship between cellular apoptosis, proliferation and bcl-2/bax expression in the tissue of colorectal carcinoma and biological behavior of the tumor. METHOD: The apoptotic cells index (AI) in situ were identified by the terminal deoxynucleotidyl transfer-mediated dUTP-biotin nick end labeling (TUNEL) and immunohistologic staining for Ki-67 proliferation index (KI), bcl-2/bax protein expression was performed on archival material from 77 adenocarcinomas. RESULT: The mean AI and KI were 5.3/45.4 in early stage cancer, 5.6/48.7 in non-metastatic cancer, 6.6/55.3 in advanced cancer and 8.9/60.1 in cancer with distant metastasis respectively. There was a positive relationship between the AI and KI in each specimen. bcl-2 and bax was expressed as 54.5%, 74% in carcinoma and highly differentiated carcinoma. In the univariate analysis, significantly longer survival time was observed in the subgroup of bcl-2 positive carcinoma with low AI. In the multivariate analysis, tumor stage, tumor type, KI, and bcl-2 expression were independent risk factors for prognosis. CONCLUSION: The data indicate that abnormally exchanged AI/KI, bcl-2/bax expression appears to be an event associated with tumor progression and apoptosis might also reflect the proliferative activity of human colorectal carcinoma.

Apoptosis↗
PubMed1998

[Surgical treatment of cervical 1, 2 neurinomas].

OBJECTIVE: To analyse retrospectively 15 cases of C(1) and C(2) neurinomas treated between 1986 - 1997. METHOD: All patients were examined by clinical neurology, neuroradiology (CT/MRI/DSA) and identified operatively and pathologically. All samples were studied histopathologically. RESULT: Except 1 patient died from menotic nerve sheath tumor involving medulla oblongata and pia mater, 14 patients were cured. CONCLUSION: Lateral approach may be idoal in total tumor resection and improvement of neurological symptoms.

Adolescent↗
PubMed1998

[An experimental research of recombinant human epidermal growth factor on corneal wound healing].

OBJECTIVE: To investigate the effects of recombinant human epidermal growth factor (rhEGF) eye drops on corneal wound healing. METHODS: Twenty-four white rabbits were randomly divided into 4 groups, 6 rabbits 12 eyes each. Anterior keratectomy of 8 mm in diameter and 1/3 cornea in thickness was performed on each eye. Each of the following concentrations of rhEGF: 1, 10, 100 microg/ml eye drops or normal saline (control) was applied four times daily for a week respectively for one group. The wound area was determined by computer imaging analysis. RESULTS: The mean epithelial healing rate of rhEGF 1, 10, 100 microg/ml groups was 9.31, 9.96, 9.31 mm(2)/day respectively, significantly greater than 8.11 mm(2)/day of the control group. The action of rhEGF of 10 microg/ml was somewhat better than that of 1 or 100 microg/ml, and no significant difference was noticed among the three rhEGF groups. Moderate inflammation and corneal neovascularization were induced in the rhEGF 100 microg/ml treated group. CONCLUSION: rhEGF 1 - 10 microg/ml can accelerate corneal wound healing in the rabbit with no adverse side-effects. It may be used to treat serious corneal trauma and ulcer clinically.

Animals↗
PubMed1998

[Correlations between factors and intraocular pressure following photorefractive keratectomy].

OBJECTIVE: To evaluate the factors related to intraocular pressure (IOP) after excimer laser photorefractive keratectomy (PRK). METHODS: 86 cases 150 eyes of myopia followed over six months after PRK were studied with noncontact tonometer (NCT). RESULT: After PRK, a decrease in the IOP was observed. Post-operatively, the IOP reading at 1st month was the highest. The reduction of IOP may be related to the decrease in corneal thickness and corneal curvature (r = 0.361, P < 0.01; r = 0.188, P < 0.05). Regression equation for IOP drop (kPa) = - 0.059 - 0.038X(1) + 0.009X(2)[X(1) = ablation depth (microm), X(2) = decrease in corneal curvature (D)]. CONCLUSION: IOP readings after PRK are influenced by corneal thickness, corneal curvature and eye drug times.

Adult↗
PubMed1998

[Extraction and amplification of DNA from formalin-fixed human tissues].

A method was developed for the extraction of DNA from formalin-fixed human tissues prepared for routine histopathological examination. The extracted DNA was not intact. By increasing the formalin fixation time the necessary amount of intact DNA decreased. The procedure reported here made the final product suitable for quantitative and qualitative analysis and for DNA-typing by PCR technique.

DNA↗
PubMed1998

[PCR-based detection of HLA-DQ alpha and polymarker loci and their application in forensic science].

Studies were conducted to evaluate the forensic applicability of multiplex amplification of HLA-DQ alpha and PM loci. These loci could be simultaneously typed by reverse dot blot approach where allele specific oligonucleotide probes were immobilized on a nylon membrane strip. Allele and genotype frequencies for HLA-DQ alpha and PM loci were determined in Chinese Han population. The frequency data can be used in individual identification and paternity test.

Female↗