Biomedical subjects

Li He

Publications and source records attributed to Li He.

44 records · Page 3Linked to original sources

PubMed2003

[Detection of severe acute respiratory syndrome (SARS)-associated coronavirus RNA in autopsy tissues with in situ hybridization].

OBJECTIVE: To explore the distribution of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) in SARS autopsy tissues at the molecular level. METHODS: In situ hybridization was used to detect the expression and location of SARS-CoV RNA polymerase gene in autopsy tissues from SARS-Cov-infected subjects, including the lung, spleen, lymph nodes, pituitary, pancreas, parathyroid, adrenal glands, gastrointestinal tract, skin, brain, liver, kidney, blood vessels, striated muscles of the limbs, bone marrow, heart, ovary, uterus and testicles. RESULT: SARS-CoV RNA was detected in the cytoplasm of the alveolar epithelia, infiltrating mononuclear phagocytes in the lungs, serous gland epithelium of the trachea/bronchus, monocytes in the spleen and lymph nodes, acinar cells in the pancreas, acidophilic cells in the parathyroid and pituitary, adrenal cortical cells, epithelia of the alimentary tracts, gastric parietal cells, sweat gland cells, brain neurons, hepatocytes near the central vein, epithelia of the distal renal tubules, bone marrow promyelocytes, and endothelia of the small veins. CONCLUSIONS: SARS-CoV invades various organs of the body and distributes in a similar fashion to CD13, the receptor of human coronavirus 229E. The detection of SARS-CoV in the sweat glands, alimentary tracts and epithelia of the distal convoluted tubules of the kidney may help identify the transmission routes of SARS-CoV.

Autopsy↗

PubMed2003

[Expression of the monoclonal antibody against nucleocapsid antigen of SARS-associated coronavirus in autopsy tissues from SARS patients].

OBJECTIVE: To investigate the presence and distribution of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) in autopsy tissues obtained from patients died of SARS. METHODS: Immunohistochemical technique was applied in 4 fatal SARS cases to examine the autopsy tissues including the lungs, spleen, lymph nodes, brain, pituitary, heart, liver, kidney, pancreas, trachea, esophagus, gastrointestinal tract, adrenal glands, parathyroids, skin and bone marrow. RESULTS: Immunohistochemistry identified positive monoclonal antibody against SARS-CoV nuceeocapsid (N) protein in the alveolar epithelium and the infiltrating monocytes or macrophages in the lung, spleen and lymph nodes; the presence of the antibody was also detected in the serous gland epithelium of the trachea/bronchus, squamous epithelium of the esophagus, the gastric parietal cells, the epithelium of the intestinal tract, acidophilic cells in the parathyroids and pituitary, acinus cells in the pancreas, adrenal cortical cells, sweat gland cells, small vessel endothelium, bone marrow promyelocytes, epithelial cells of the distal convoluted tubule of the kidney, brain neurons, and the hepatocytes near the central vein. CONCLUSIONS: A variety of organs and tissues can be infected by SARS-CoV, and the positive expression of SARS-CoV N protein in the epithelial cells of the gastrointestinal tract, the distal convoluted tubule of the kidney and the sweat gland cells is significant for studying the transmission routes of SARS.

Antibodies, Monoclonal↗

PubMed2003

[Basic study of dopamine transporter imaging with 131I-beta-CIT].

beta-CIT was labeled with 131I by the peracetic acid method. Cat model of Parkinsonism was set up with MPTP. Each of normal and PD model cats was given an injection of 74 MBq/0.5 ml 131I-beta-CIT into the femur vein. Then the blood samples were obtained at 4 h and 20 h, the radioactivity was counted with calibrator. The biodistribution data of 131I-beta-CIT in cat body was calculated (ID%/g). The cats were subjected to imaging at 0.5 h, 1 h, 2 h, 4 h, 20 h after the administration of radiopharmaceutical. The radioactivity in striatum and cerebellum was measured and striatal specific binding ratios were calculated. The Results showed that the radio chemical purity of 131I-beta-CIT was 97.62% +/- 0.31%. The 131I-beta-CIT remained stable for at least 4 h after incubation with water and serum respectively. Following intravenous administration in cats, 131I-beta-CIT showed high accumulation in striatum. The study of imaging in cats showed that striatal specific uptake of 131I-beta-CIT at 20 h after injection was 4.83 +/- 0.82 in normal cats and 2.92 +/- 0.66 in PD cats. There was a significant reduction of striatal tracer uptake in PD cats, compared to the controls. The results of biodistribution study was in agreement with the results of imaging study. These results suggest that beta-CIT is an ideal agent for dopamine transporter imaging and can be used for the diagnosis of Parkinson's disease.

Animals↗

PubMed2003

[Studies on flavonoids of Anaphalis sinica].

OBJECTIVE: To investigate the chemical constituents of Anaphalis sinica. METHOD: Various chromatographic techniques were employed for the isolation and purification of the constituents. The structures were elucidated by chemical and spectral analysis. RESULT: Six flavonoid compounds were isolated and identified as kaempferol, tiliroside, quercetin, quercetin -3-O-beta-D-glucosides, scutellarin, 5,7-dihydroxy-8-methoxyflavone and one pyrone were isolated and identified as helipyrone. CONCLUSION: All of these compounds was isolated from the plant for the first time.

Asteraceae↗

PubMed2003

[Studies on chemical constituents in herb of Lamium maculatum L. var Kansuense].

OBJECTIVE: To study the chemical constituents from Lamium maculatum L. var Kansuense. METHOD: The chemical constituents were isolated and repeatedly purified by silica gel column chromatography and the structures were elucidated by the NMR spectra and physico-chemical properties. RESULT: Ten compounds were obtained and they were identified as D-mannitol, beta-sitosterol, stigmasterol, rutin, 3'-methylquercetin-3-O-rutinoside, n-butyl-beta-D-fructopyranoside, daucosterol, acteoside, 20-hydroxyecdysone, allantoin. CONCLUSION: All the compounds were obtained from L. maculatum L. var Kansuense for the first time.

Allantoin↗

PubMed2002

Regulation of opioid receptor trafficking and morphine tolerance by receptor oligomerization.

The utility of morphine for the treatment of chronic pain is hindered by the development of tolerance to the analgesic effects of the drug. Morphine is unique among opiates in its ability to activate the mu opioid receptor (MOR) without promoting its desensitization and endocytosis. Here we demonstrate that [D-Ala(2)-MePhe(4)-Gly(5)-ol] enkephalin (DAMGO) can facilitate the ability of morphine to stimulate MOR endocytosis. As a consequence, rats treated chronically with both drugs show reduced analgesic tolerance compared to rats treated with morphine alone. These results demonstrate that endocytosis of the MOR can reduce the development of tolerance, and hence suggest an approach for the development of opiate analogs with enhanced efficacy for the treatment of chronic pain.

Adrenergic beta-Agonists↗

PubMed2002

Heparin cofactor II inhibits arterial thrombosis after endothelial injury.

Heparin cofactor II (HCII) is a plasma protein that inhibits thrombin rapidly in the presence of dermatan sulfate, heparan sulfate, or heparin. HCII has been proposed to regulate coagulation or to participate in processes such as inflammation, atherosclerosis, and wound repair. To investigate the physiologic function of HCII, about 2 kb of the mouse HCII gene, encoding the N-terminal half of the protein, was deleted by homologous recombination in embryonic stem cells. Crosses of F1 HCII(+/-) animals produced HCII(-/-) offspring at the expected mendelian frequency. Biochemical assays confirmed the absence of dermatan sulfate-dependent thrombin inhibition in the plasma of HCII(-/-) animals. Crosses of HCII(-/-) animals produced litters similar in size to those obtained from heterozygous matings. At 1 year of age, HCII-deficient animals were grossly indistinguishable from their wild-type littermates in weight and survival, and they did not appear to have spontaneous thrombosis or other morphologic abnormalities. In comparison with wild-type animals, however, they demonstrated a significantly shorter time to thrombotic occlusion of the carotid artery after photochemically induced endothelial cell injury. This abnormality was corrected by infusion of purified HCII but not ovalbumin. These observations suggest that HCII might inhibit thrombosis in the arterial circulation.

Animals↗

PubMed2002

[Influence of calcium content among different calcium agents on absorbing and bone density of rats].

To identify the influence of different calcium contents among different calcium agents on absorbing and born density of rats, wistar rats are fed with diet containing different contents of calcium of different calcium agents. 3-day calcium metabolization experiment is carried out in the fourth week and atomic absorption spectrophotometry is applied to measure the calcium content of their dejecta and to estimate apparent absorptivity. Rats are killed in the twelfth week, and their thighbones are peeled. the results show that there is significant difference of the apparent absorptivity with different calcium intake. With the same content of calcium from nine kinds of calcium agents, the absorptivity is not significant different with an exception of those of active calcium, milk powder and oatmeal. Born density from the group of rats, which fed with diet with low level, middle level or high level of calcium, is obviously higher than that of rats fed with basic diet (P < 0.05). Born density of thighbone of the group of rats, which fed with diet with middle or high level of calcium content is not significantly different compared with that of rats fed with diet with calcium carbonate. The absorptivity of calcium is related with calcium content in diet. The effect of absorptivity of calcium agents tested is affirmative, but there is no difference of their effect in comparison with the calcium carbonate.

Animals↗