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Biomedical subjects

Hong Shen

Publications and source records attributed to Hong Shen.

At least 109 records · Page 6Linked to original sources
PubMed2003

[Observation on the effects of urapidil on hemodynamics in heart dysfunction dogs by thoracic electrical bioimpedance].

OBJECTIVE: To observe the effects of urapidil on hemodynamics in heart dysfunction dogs by thoracic electrical bioimpedance. METHODS: Sixteen health anesthesia dogs were taken pentobarbital till their hearts dysfunction. Then 10 dogs were taken urapidil injection (4 microg x kg(-1) x min(-1)) and 6 dogs were taken the same doses of normal saline, and heart rate (HR), stroke volume (SV), cardiac output (CO), pre-ejection period (PEP), left ventricular ejection time (LVET), systole time ratio (STR), isovolumic relaxation time (IRT), pulmonary capillary wedge pressure (PCWP), left ventricular end-diastolic pressure (LVEDP), total peripheral resistance (TPR), stroke work (SW) and cardiac work (CW) were continuously monitored by non-invasive hemodynamic monitoring system. Data were recorded at 15 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after dysfunction. RESULTS: Compared to the group of normal saline, urapidil could increase CO and SV, shorten PEP and STR, decrease PCWP, LVEDP and TPR, increase SW and CW. CONCLUSION: The change of hemodynamics in heart dysfunction dogs can be observed, non-invasively and accurately, by thoracic electrical bioimpedance. Urapidil can obviously decrease preload and postload of heart, increase CO and myocardial contract potentiality, and improve heart function.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed2003

[Pathogenic mechanisms of enterotoxigenic Escherichia coli in guinea pigs].

OBJECTIVE: To explore the pathogenic mechanisms of enterotoxigenic Escherichia coli (ETEC) in guinea pigs. METHODS: Pathological examination of the intestines was performed in ETEC-infected guinea pigs, and the intracellular free Ca2+ concentration, cytoplasmic pH, cell membrane potential and mitochondria membrane potential were determined immunohistochemically and by means of flow cytometry. RESULTS: The guinea pigs were sensitive to the human-origin ETEC, which caused pathological changes in the small intestines such as edema, hyperemia and lymphocyte infiltration, but no bacteria invasion into the epithelial cells was identified. Under transmission electron microscope, the ileal epithelial cells were shown with vacuolar degeneration and evidence of mitochondrial proliferation; heat-labile (LT) and heat-stable (ST) toxins pervaded in the ileal tissue, resulting in significant increase of intracellular free Ca2+ concentration, cytoplasmic pH value and cell membrane potential, with concomitance of significant decrease in mitochondrial membrane potential. CONCLUSIONS: ETEC disturbs the absorption and secretion functions of the intestinal epithelial cells, and induces extensive inflammation in the small intestines of guinea pigs. Besides their action on intestinal epithelial cells, LT and ST also affect the myocytes in the muscularis, and their action sites and mechanism might be similar. ETEC-induced diarrhea is correlated with excessive water excretion from the cells.

Animals↗
PubMed2003

[The emission of rare earth complex Eu(asprin)3phen].

Two kinds of electroluminescent devices were fabricated by doping the rare earth complex Eu(asprin)3phen into polymer PVK: (1) ITO/PVK:RE/LiF/Al; (2) ITO/PVK:RE/PBD/LiF/Al. A great difference in the EL spectrum was found between the two kinds of devices. In device (2) the intensity of 594 nm was rather weak compared with that of 614 nm. The spectrum was consistent with the photoluminescence (PL) spectrum under the state of thin film. But in device (1), the peak emission of 594 nm was comparable to that of 614 nm. Preliminary discuss on this phenomenon was made; in device (1), the recombination region was close to the metal cathode, effect of metal cathode on the electroluminescence of the rare earth complex caused the changes of the EL emission which was quite different from the TL emission. The phenomenon was not observed in device (2) whose recombination region was far from the cathode because an electron-transport layer was inserted.

Chelating Agents↗
PubMed2003

[Effects of naloxone on rat cortical neuron apoptosis induced by anoxia].

OBJECTIVE: To investigate the damage of anoxia on the cultured rat's cortical neurons and the protective effects of naloxone. METHODS: Cortical neurons cultured for 12 days were randomly divided into three groups: control, anoxic group and anoxic group plus naloxone treated. Cortical neurons were exposed to anoxic environment for 6 hours and then cultured for 24 hours under normoxic condition. The apoptosis of neurons was detected with the method of TdT-mediated dUTP nick end labeling (TUNEL) and the apoptotic rate of neurons was measured using flow cytometry. RESULTS: Anoxia could lead to increasing apoptosis and death of rate cortical neurons. Naloxone could reduce neuron apoptosis. There was a significant difference between the anoxic group and anoxic group plus naloxone (P<0.01). CONCLUSION: Naloxone can ameliorate the toxicity damage of neurons caused by anoxia through reducing neuron apoptosis, which suggests that naloxone could protect rat's cortical neurons from damage under anoxia condition.

Animals↗
PubMed2003

[Analysis of false-positive associated with antibody tests for SARS-CoV in SLE patients].

To discuss the false-positive of serological diagnostic testing for coronavirus antibody in patients with systemic lupus erythematosus(SLE), 66 normal individual and 31 SLE with non-SARS patients were detected for SARS-associated coronavirus (SARS-CoV) antibody and RNA by enzymelinked immunosorbent assays(ELISA) and reverse transcriptase-polymerase chain reaction(RT-PCR). The result showed 2/66 cases(3.0%) were positive of SARS-CoV-IgG antibody and 66 cases were negative of SARS-CoV-IgM antibody in the 66 cases healthy controls; in 31 cases with SLE, positive rates of SARS-CoV-IgG and IgM antibody were 58.1% (18/31) and 29% (9/31), respectively, in which 7 cases(22.6%) were positive of both SARS-CoV-IgG and IgM antibody. All samples of positive SARS-CoV-IgG and IgM antibody were negative by RT-PCR. The ELISA kit coated by non-purification antigen may induce the false-positive of SARS-CoV antibody in patients with SLE. This result suggested that the specificity of ELISA tests for SARS was excellent and has low false-positive rates when using SARS-CoV-IgG and IgM antibody tests. A possible cause of false-positive of SARS-CoV-IgG and IgM antibody in SLE patients is coated antigens with SARS-CoV and Vero-E6 cells in ELISA methods.

Adolescent↗
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

[Mycosis of the tonsil].

OBJECTIVE: To evaluate the early diagnosis ways of the tonsil mycosis. METHOD: The study was designed to investigate 18 patients with mycosis of tonsil in the PUMC hospital since 1995 year. Direct smear and microscopical examination of secretory material, tissues from tonsil infection were conducted; fungus culture was performed in the fungi positive cases for microscopical identification. RESULT: The diagnosis of all patients were demonstrated by the pathogeny check at last. CONCLUSION: The direct smear examination and fungus culture are important methods for early diagnosis to the mycosis of tonsil.

Adolescent↗
PubMed2003

[Effect of handportable mobiletelephone microwave radiation on rat central neuron apoptosis].

OBJECTIVE: To investigate the effect of handportable mobiletelephone microwave radiation on rat central nervous system by setting up rat model. METHODS: 80 healthy male SD rats (weighed about 200 g) were divided into 4 groups at random: control, radiation, decranium, decranium + radiation. TUNEL method was adopted used to detect the apoptosis of neurons after irradiation, then immunohistochemistry was used to detect Bcl-2, Bax expression in all brain tissue. RESULTS: TUNEL positive rate, Bax and Bcl-2 positive cell numbers could be found in decranium + radiation group [(26.45 +/- 9.27)%, (23.5 +/- 3.58), (11.1 +/- 2.55) respectively]. There were significant differences among control [(9.59 +/- 2.55)%, 14.2 +/- 2.46, 7.0 +/- 1.14 respectively], decranium group [(9.52 +/- 1.93)%, 15.5 +/- 1.77, 7.4 +/- 1.76], radiation group [(10.04 +/- 3.62)%, 15.9 +/- 2.02, 7.2 +/- 1.07] (P < 0.01). But the difference was not found in the ratio of Bax to Bcl-2. CONCLUSION: Microwave radiation did not affect the intact rat, but did promote the occurrence of neuron apoptosis in cranial defect rat. Bax, Bcl-2 gene participated in regulation of apoptosis. The intact cranium may be an important factor to protect the neurons against handportable mobiletelephone microwave radiation to some extent.

Animals↗
PubMed2002

Targeted disruption of the PEPT2 gene markedly reduces dipeptide uptake in choroid plexus.

The presence of multiple oligopeptide transporters in brain has generated considerable interest as to their physiological role in neuropeptide homeostasis, pharmacologic importance, and potential as a target for drug delivery through the blood-brain and blood-cerebrospinal fluid barriers. To understand further the purpose of specific peptide transporters in brain, we have generated PEPT2-deficient mice by targeted gene disruption. Homozygous PepT2 null mice lacked expression of PEPT2 mRNA and protein in choroid plexus and kidney, tissues in which PepT2 is normally expressed, whereas heterozygous mice displayed PepT2 expression levels that were intermediate between those of wild-type and homozygous null animals. Mutant PepT2 null mice were found to be viable, grew to normal size and weight, and were without obvious kidney or brain abnormalities. Notwithstanding the lack of apparent biological effects, the proton-stimulated uptake of 1.9 microm glycylsarcosine (a model, hydrolysis-resistant dipeptide) in isolated choroid plexus was essentially ablated (i.e. residual activity of 10.9 and 3.9% at 5 and 30 min, respectively). These novel findings provide strong evidence that, under the experimental conditions of this study, PEPT2 is the primary member of the peptide transporter family responsible for dipeptide uptake in choroid plexus tissue.

Animals↗
PubMed2002

Suppressive effect of Astragalus membranaceus Bunge on chemical hepatocarcinogenesis in rats.

Astragalus membranaceus (AM) has been widely used for treating liver diseases in traditional Chinese medicine. Experimental evidence indicates that it has antitumor potential. In this study, the effect of AM on hepatocarcinogenesis induced by diethylnitrosamine (DEN), two-thirds partial hepatectomy, and 2-acetylaminofluorene (2-AAF) (DEN-PH-AAF) was evaluated using glutathione S-transferase placenta form (GST-P) as marker. First, rats were injected intraperitoneally (i.p.) with DEN (200 mg/kg in saline), a two-thirds partial hepatectomy was carried out 2 weeks later, and the rats were then placed on a basal diet containing 0.02% AAF from week 3 to week 8 to induce hepatocarcinogenesis. The rats were given AM (90 mg/kg or 180 mg/kg body weight) by gavage from week 3 to week 8 (treatment groups). The formation of GST-P-positive foci and the expression of GST-P protein and mRNA caused by DEN-PH-AAF were reduced in the treatment groups, which clearly suggests that AM is effective in delaying DEN-PH-AAF-induced hepatocarcinogenesis.

2-Acetylaminofluorene↗
PubMed2002

Different effects of rat interferon alpha, beta and gamma on rat hepatic stellate cell proliferation and activation.

BACKGROUND: Liver fibrosis is the common sequel of chronic liver diseases. Recent studies have identified hepatic stellate cells as the primary cell type mediating hepatic fibrogenesis. It has been demonstrated that hepatic stellate cells undergo a process of activation during the development of liver fibrosis. During the activation process, hepatic stellate cells acquire myofibroblast-like phenotype featuring the expression of smooth muscle alpha actin. Interferons have been employed for the treatment of viral hepatitis. However, it is unclear what is the effect of interferons on the prevention and treatment of liver fibrosis. Moreover, it is not clear whether there are any differences among interferon alpha, interferon beta, and interferon gamma in the treatment of liver fibrosis. Therefore, our objective in current study is to investigate the effects of rat interferon-alpha, interferon-beta, and interferon-gamma on the proliferation and activation of rat hepatic stellate cells. RESULTS: Rat interferon-beta and interferon-gamma significantly inhibited rat hepatic stellate cell proliferation while rat interferon-alpha did not affect the cell proliferation under the same culture condition. Inhibition of cell proliferation was confirmed by both WST-1 cell proliferation assay and 5-bromo-2'-deoxy-uridine incorporation assay. Similar results were observed regarding interferons regulation of hepatic stellate cell activation. Both rat interferon-beta and interferon-gamma reduced smooth muscle alpha-actin abundance after 6 days treatment, but rat interferon-alpha did not alter smooth muscle alpha-actin level. CONCLUSIONS: Our results indicate that rat interferon-alpha and interferon-beta have different biological effects on rat hepatic stellate cells and suggest that there are different signaling events between interferon-alpha and interferon-beta in hepatic stellate cells.

Actins↗
PubMed2002

Role of PEPT2 in peptide/mimetic trafficking at the blood-cerebrospinal fluid barrier: studies in rat choroid plexus epithelial cells in primary culture.

Recent studies have established the functional and molecular presence of a high-affinity peptide transporter, PEPT2, in whole tissue rat choroid plexus. However, the precise membrane location and directionality of PEPT2-mediated transport is uncertain at present. In this study, we examined the transport kinetics of a model dipeptide, glycylsarcosine (GlySar), along with the protein expression of PEPT2 using primary cell cultures of choroidal epithelium from neonatal rats. GlySar accumulation and transepithelial transport were 3 to 4 times higher when introduced from the apical as opposed to the basal side of the monolayers. GlySar apical uptake was also stimulated by an inwardly directed proton gradient. The uptake of GlySar was inhibited by di/tripeptides, carnosine, and alpha-amino cephalosporins but was unaffected by amino acids, cephalosporins lacking an alpha-amino group, and organic anions and cations. The Michaelis constant (K(m)) of GlySar was 59.6 microM for apical uptake and 1.4 mM for basal uptake; this is consistent with the high-affinity properties of PEPT2 at the apical membrane. Immunoblot analyses and immunofluorescent confocal microscopy demonstrated the presence of PEPT2, but not PEPT1, in rat choroid plexus epithelial cells. Moreover, PEPT2 was present in the apical and subapical regions of the cell but was absent in the basolateral membrane. These findings demonstrate, for the first time, that PEPT2 protein is present at the apical membrane of choroidal epithelial cells and that it is functionally active at this membrane surface. The results suggest that PEPT2 may have a role in the efflux of peptides and/or mimetics from cerebrospinal fluid to the blood.

Animals↗
PubMed2002

In vivo gene transfer using a nonprimate lentiviral vector pseudotyped with Ross River Virus glycoproteins.

Vectors derived from lentiviruses provide a promising gene delivery system. We examined the in vivo gene transfer efficiency and tissue or cell tropism of a feline immunodeficiency virus (FIV)-based lentiviral vector pseudotyped with the glycoproteins from Ross River Virus (RRV). RRV glycoproteins were efficiently incorporated into FIV virions, generating preparations of FIV vector, which after concentration attain titers up to 1.5 x 10(8) TU/ml. After systemic administration, RRV-pseudotyped FIV vectors (RRV/FIV) predominantly transduced the liver of recipient mice. Transduction efficiency in the liver with the RRV/FIV was ca. 20-fold higher than that achieved with the vesicular stomatitis virus G protein (VSV-G) pseudotype. Moreover, in comparison to VSV-G, the RRV glycoproteins caused less cytotoxicity, as determined from the levels of glutamic pyruvic transaminase and glutamic oxalacetic transaminase in serum. Although hepatocytes were the main liver cell type transduced, nonhepatocytes (mainly Kupffer cells) were also transduced. The percentages of the transduced nonhepatocytes were comparable between RRV and VSV-G pseudotypes and did not correlate with the production of antibody against the transgene product. After injection into brain, RRV/FIV preferentially transduced neuroglial cells (astrocytes and oligodendrocytes). In contrast to the VSV-G protein that targets predominantly neurons, <10% of the brain cells transduced with the RRV pseudotyped vector were neurons. Finally, the gene transfer efficiencies of RRV/FIV after direct application to skeletal muscle or airway were also examined and, although transgene-expressing cells were detected, their proportions were low. Our data support the utility of RRV glycoprotein-pseudotyped FIV lentiviral vectors for hepatocyte- and neuroglia-related disease applications.

Animals↗
PubMed2002

Evaluation of a method for high throughput solubility determination using a multi-wavelength UV plate reader.

Aqueous solubility is a critical physicochemical property and must be addressed early during drug discovery research. Due to the difficulty in accurately predicting aqueous solubility in silico, high throughput experimental determination of aqueous solubility is in great demand. This study evaluates a method using a multi-wavelength UV plate reader and disposable 96-well UV plates for fast solubility determination. It was demonstrated that this method has the sensitivity and reproducibility to effectively determine solubility as low as 1 micro M. Excellent correlation (R>0.97) was observed between the solubility determined using the UV reader method and the HPLC method over the range of 1-1000 micro M for a diverse set of pharmaceutical compounds. In addition to excellent sensitivity and reproducibility, the UV plate reader method also offers the flexibility of being able to determine thermodynamic solubility in the presence or absence of dimethyl sulfoxide, which is a solvent widely used for combinatorial compounds during high throughput screening.

Drug Evaluation, Preclinical↗
PubMed2002

Usefulness of determining a protein induced by vitamin K absence in detection of hepatocellular carcinoma.

OBJECTIVE: Protein induced by vitamin K absence or antagonist II (PIVKA II), also called des-gamma carboxy prothrombin (DCP), is a sensitive marker for the diagnosis of hepatocellular carcinoma (HCC), in Japan and the United States since the sensitive kits were available (1998). PIVKA II is not used in clinical diagnosis in China so far. The aim of this study was to assess the diagnostic value of PIVKA II in Chinese patients with HCC. METHODS: Serum PIVKA II and alpha-fetoprotein (AFP) levels were determined in 60 patients with HCC and 30 patients with cirrhosis not carrying HCC. RESULTS: The mean serum concentration of PIVKA II in HCC patients (784.3 +/- 1364.1 mean +/- s) was higher than that in cirrhosis patients (16.1 +/- 31.7); this difference was highly significant (P < 0.0001). When the cutoff level of 40 mAU/ml was used as the level of discriminating HCC from cirrhosis, 51.7% of patients (31/60) with HCC had PIVKA II values above this level (sensitivity). Only 4 patients with cirrhosis had such high PIVKA II levels. Thus, the specificity of this test was 86.7% (26/30). Total accuracy was 62.2% [(31 + 26)/(60 + 30)]. Seven of 19 small HCCs (36.84%) had PIVKA II values above the cutoff level. Concentrations of AFP above 20 ng/ml were observed in 34 of 60 patients with HCC (56.7%) and in 11 patients with cirrhosis (36.7%). Eleven of 26 patients with HCC (46.2%) without increased AFP had concentrations of PIVKA II greater than 40 mAU/ml. No significant correlation was found between serum levels of AFP and PIVKA II that were measured in 60 HCC patients (rs = 0.101, P = 0.247). Combining the information from PIVKA II and AFP showed an increase of approximately 21.6% over AFP and 26.7% over PIVKA II alone. For small HCC patients, combining the information from PIVKA II and AFP showed an increase of approximately 15.8% over AFP alone and 21.1% over PIVKA II alone. CONCLUSION: PIVKA II is a useful early diagnostic marker for HCC and may be more sensitive when combined with AFP in Chinese patients.

Adult↗