Biomedical subjects

Hong Shen

Publications and source records attributed to Hong Shen.

114 records · Page 7Linked to original sources

PubMed2002

[Exudation and accumulation of citric acid in common bean in response to Al toxicity stress].

Significant differences in the exudation and accumulation of citric acid in common bean genotypes were observed in response to Al toxicity stress by hydroponic cultural experiments. Secreted citric acid increased with increasing external concentrations of Al3+ which ranged from 0 to 50 mumol.L-1, while ranged from 50 to 80 mumol.L-1, secreted citric acid decreased with increasing external concentrations of Al3+. Among different genotypic common beans, citric acid secreted in G19842 was the largest, while Al uptake per unit dry weight in G19842 was the least. No difference in the accumulation of citric acid in leaves was found among different genotypic common beans, while the size of the content of citric acid in roots was G19842 > AFR > ZPV > G5273. The amount of citric acid exuded was smaller induced by phosphorus deficiency than that induced by Al toxicity stress. Exposure to 50 mumol.L-1 LaCl3 could not induce the exudation of citric acid, and it implied that the exudation and accumulation of citric acid in common bean was an important physiological response of resistance to Al toxicity stress.

Aluminum↗

PubMed2002

Morphological changes in canine lungs perfused with modified Euro-Collins solution.

OBJECTIVE: To investigate the structural changes in canine lungs perfused with modified Euro-Collins solution (mECS), thus providing insight into the preservation of the donor lung tissue for transplantation. METHODS: Six dogs were anesthetized and pulmonary perfusion with mECS (4 degrees Celsius) was performed before the lungs were isolated thereafter and stored at 4 to 8 degrees Celsius for 30, 60, 120, 180, 240 min respectively, after which tissue samples of the donor lung were taken for morphological observation with both light and transmission electron microscope. RESULTS: Immediately after reperfusion, the pulmonary tissues exhibited clear and intact structures,showing that mitochondrion swelled slightly in the alveolar epithelial cells (AECs). Mild edema occurred in the alveolar wall and the tissues around the veins at 30 min after preservation, which exacerbated to dilapidation of the alveolar wall and obvious tumefaction of the mitochondrion in the AECs at 60 min. At 180 min, rupture of alveolar wall and emergence of the alveolus was observed at 120 min, and a few pulmonary bullae were formed, the AECs (I) of which presented vacuolar changes in the cytoplasma and mitochondrion, with disappearance of the tiny villus of the AECs (II) at 240 min. CONCLUSION: Within 4 h of preservation in mECS, the pulmonary tissues do not undergo obvious changes as signs of injury, which, however, may not be the case after longer preservation.

Animals↗

PubMed2002

[The microarray study on the stress gene transcription profile in human retina pigment epithelial cells exposed to microwave radiation].

OBJECTIVE: To study the difference in stress and apoptosis related genes transcription between hTERT-RPE1 cells exposed to simulated microwave radiation and the cells with heat water bath, and the effects of microwave on gene transcription in cultured human retina pigment epithelial cells. METHODS: cDNA microarray technique was used to detect the mRNA isolated from hTERT-RPE1 cells exposed to 2 450 MHz simulated microwave radiation and with heat water bath, respectively. RESULTS: Among the 97 related aim genes, there were seven genes up-regulating its transcription, i.e., M31166 (2.52fold), L24123 (2.66fold), AF039704 (2.22fold), U67156 (2.07fold), AF040958 (2.13fold), NM-001423 (2.63fold) and NM-005346 (3.68fold). But, no notably down-regulating gene in transcription was detected. CONCLUSIONS: Microwave could induce up-regulating in multiple stress and apoptosis related genes transcription in cultured human retina pigment epithelial cells, hTERT-RPE1 cells. Microwave radiation has unique effect itself in addition to its heat effect.

Gene Expression Profiling↗

PubMed2002

[Study on antiinflammatory effect of a compound TCM agent containing ant extractive in animal models].

OBJECTIVE: To study the antiinflammatory effect of a compound TCM (Traditional Chinese Medicine) agent on animal models. The agent contains ant extractive and a blent of three herbal products, herba epimedii, fructus cnidii, and fructus lycii. METHOD: Three animal models to induce experimental inflammation in rats, including carrageenin--induced paw edema, cotton-ball granuloma and adjuvant induced arthritis, were chosen to study the antiinflammatory effect of the TCM agent. RESULT: The TCM agent showed a marked inhibitory effect on edema induced by all three types of inflammation in rats, the inhibitory rate of the TCM agent at the dose of 0.20, 0.40 and 0.80 g.kg-1 in granuloma model bing over 25% at 1 hour post oral administration, and being 23.8%, 22.7%, 39.7% at 6 hour. In addition, the TCM agent also showed a significant preventive as well as therapeutic effect on adjuvant induced arthritis in rats, and improved the pathological changes of the animal joints with the induced arthritis. CONCLUSION: TCM agent has significant antiinflammatory effects on the three above mentioned animal models.

Animals↗

PubMed2002

[Two mechanisms of the color-tunable organic electroluminescence by the voltage applied].

Two devices structures of ITO/PVK: Rubrene/Al and ITO/Alq3:MN-PPV/Al were developed. Their characters of photoluminescence and electroluminscence were studied. The result showed that there were great difference between the photoluminescence and electroluminscence at a doping ratio of 2 wt% in ITO/PVK: Rubrene/Al. It is concluded that energy transfer in these dye-doped devices occurred by Förster energy transfer processes. And the trap effect of electrons of Rubrene on holes of PVK resulted in different combination probability of PVK excitation in photoluminescence and electroluminescence. At the same time, the two EL devices were color-tunable when the bias voltage was increased. The mechanisms which cause color variation are different. In the first device, it indicates that the energy transfer process from PVK to Rubrene is not complete. The combination probability of PVK excitation which does not contribute to the emission of Rubrene is increased when the bias voltage increases. But in the second device, there are many micro-interfaces due to the phase-separation just like the interface in a double layer device. The tunneling interface barriers of carriers is the main cause of color variation in the second device.

English Abstract↗

PubMedDate not supplied

Immunolocalization of the proton-coupled oligopeptide transporter PEPT2 in developing rat brain.

This study examined the tissue distribution, cellular localization, and developmental expression of the PEPT2 protein in rat brain. Immunoblot and immunocytochemistry analyses were performed with specific rat PEPT1 and PEPT2 antisera developed in our laboratory. Rats were examined from fetus (gestation for 17 days) to adult (day 75). On immunoblot analysis, the PEPT2 protein was detected in cerebral cortex, olfactory bulb, basal ganglia, cerebellum, and hindbrain sections of adult brain, with the strongest signals in cerebral cortex. No PEPT1 protein was found in brain. Expression levels of the PEPT2 protein in cerebral cortex were maximal in the fetus and declined rapidly with advancing age. Adult protein levels were approximately 14% of that observed in fetus. In immunofluorescence experiments, the strongest PEPT2 signals were observed in epithelial cells of the choroid plexus for both adult and neonate brains. The PEPT2 protein was exclusively expressed on the apical membrane (CSF-facing) of choroid plexus epithelia. In double labeling experiments, PEPT2 immunoreactivity in adult brain colocalized with NeuN, a neuronal marker, but not with GFAP, an astrocyte marker. In contrast, in neonatal brain, PEPT2 immunoreactivity colocalized with both GFAP and NeuN. These findings demonstrate that the PEPT2 protein is found throughout the brain. The apical expression of PEPT2 in choroid plexus suggests that it is involved in the export of neuropeptides, peptide fragments, and peptide-like drugs from cerebrospinal fluid. PEPT2 may also play a role in the regulation of neuropeptide concentrations in extracellular fluid, especially during early development.

Aging↗