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Biomedical subjects

Song Zhang

Publications and source records attributed to Song Zhang.

At least 37 records · Page 2Linked to original sources

A study of maternal hemodynamic change during healthy pregnancy and women with gestation hypertension.

OBJECTIVE: To investigate the maternal hemodynamic changes that occurs during pregnancy. To find out the difference that lie in healthy pregnancy and women with gestational hypertension. To introduce a method that is applied to shift high-risk women of gestational hypertension in pregnancy women. METHOD: Serial hemodynamic investigations (total 8 times) were performed throughout pregnancy period by radioulnar pulse wave electrical monitoring in 182 women (130 with healthy pregnancies, 52 with gestational hypertension). Analysis of variance with repeated measurements was used to evaluate the course of a number of hemodynamic indices. To identify the correlation between these changes and gestational hypertension by using above method. RESULTS: A significant difference in mean arterial pressure (MAP), cardiac output (CO), cardiac index (CI), total Peripheral Resistance (TPR) and heart rat (HR) was observed different between normal pregnancy and women with gestational hypertension. The changes of parameters in normal woman and gestational hypertension were recorded and the mechanism of gestational hypertension was heterogenous. CONCLUSION: These results provide sensitive parameters for use in early risk assessment and as a guide to preventive intervention during pregnancy.

Algorithms↗

[Dependence of Ca2+ on the acetylcholine-sensitive current in guinea pig type II vestibular hair cells].

OBJECTIVE: To explore the dependence of Ca2+ on the acetylcholine (ACh)-sensitive potassium current in guinea pig type II vestibular hair cells. METHODS: Under the whole-cell patch mode, the current amplitude of the ACh-sensitive potassium current was recorded in response to the concentration change of the extracellular or intracellular Ca2+. RESULTS: Following application of ACh, type II vestibular hair cells displayed the sustained potassium current, which was inhibited by tetraethylammonium chloride (TEA), but not inhibited by 4-aminopyrine (4-AP). The activation of the ACh-sensitive potassium current was strongly affected by the concentration of the extracellular Ca2+. The current amplitude of the ACh-sensitive potassium increased following the increase of Ca2+ concentration from 0 mmol/L to 4 mmol/L At the concentration of 4 mmol/L Ca2+, the current amplitude of the ACh-sensitive potassium current reached the maximal response. Lowering the Ca2 concentration in the external solution from 4 mmol/L to 0. 5 mmol/L, the current amplitude of the ACh-sensitive potassium current was inhibited to (36.5 +/- 6.5)%. However, no difference was found in the presence and in the absence of the intracellular heparin, which was a well-known blocker of the inositol trisphosphate-dependent calcium release channels. In addition, the calcium channel blocker, Cd2+, inhibited the ACh-sensitive potassium current. CONCLUSIONS: The activation of the ACh-sensitive potassium current in guinea pig type II vestibular hair cells was dependent on the extracellular Ca2+ influx through the calcium channel. The application of ACh would stimulate membrane Ca2+ channels; the influx of Ca2+ will then activate the calcium-dependent potassium current in guinea pig type II hair cells to mediate the hyperpolarization effect.

Acetylcholine↗

[Cause and treatment of trachea cannula exodus after executed tracheotomy].

OBJECTIVE: To explore the reason and correct management of trachea cannula exodus in the patient who had been executed tracheotomy, and reduce the occurrence of trachea cannula exodus and its complication. METHOD: To analysis retrospectively 23 cases of trachea cannula exodus after executed tracheotomy in patients who had been obstructed in upper respiratory. RESULT: In 23 cases of trachea cannula exodus, 21 cases were rescued succeeded, 1 case death, 1 case became plant man. CONCLUSION: Occurrence of trachea cannula exodus after executed tracheotomy was correlated with operative procedure, postoperative care and suitable selection of tracheal cannula. Quick-witted ability of doctor and correct management is a key that rescued succeeded.

Adolescent↗

[Comparative study of uptake and washout of 99mTcn(NOEt)2 with 99mTc-MIBI in human nasopharyngeal carcinoma cell line CNE].

OBJECTIVE: To determine the cellular kinetics of 99mTc-bis {N-ethoxy-N-ethyl dithiocarbamato-nitrido [N(NOEt)2]} in human nasopharyngeal carcinoma CNE cells line and to compare it with the cellular kinetics of 99mTc-methoxyisobutylisonitrile (MIBI) in the same conditions; to define the possible clinical application value of 99mTcN(NOEt)2 in nasopharyngeal carcinoma imaging. METHOD: 99mTcN(NOEt)2 or 99mTc-MIBI were incubated with CNE cells at 37degrees C, 22 degrees C, at different time points after incubation, the uptake and washout characteristics of radiotracers in CNE cells were investigated and compared. RESULT: The maximum uptake ratio of 99mTcN(NOEt)2 in CNE cells was 43.15%, that of 99mTc-MIBI was 11.08% (P < 0.01). The uptake of 99mTcN(NOEt)2 after 5 min incubation in CNE cells was 63% of total uptake, uptake of 99mTc-MIBI was 48% of total uptake (P < 0.05); 1 h after removal of the unbound tracer, 63.92% of the total uptake of 99TcN(NOEt)2 was retained in the CNE cells, 53. 97% of 99mTc-MIBI was retained (P < 0.05); not like 99mTc-MIBI, the cellular kinetics of 99mTcN (NOEt)2 were similar at 37 degrees C and 22 degrees C ( P > 0.05). CONCLUSION: 99mTcN(NOEt)2 may be a gamma imaging agent better than 99mTc-MIBI for nasopharyngeal carcinoma imaging. 99mTcN(NOEt)2 is a potential human nasopharyngeal carcinoma imaging agent.

Cell Line, Tumor↗

[Effect of complete Freund's adjuvant on islet beta cell apoptosis and its mechanism in non-obese diabetic mice].

OBJECTIVE: To investigate the effect of complete Freund's adjuvant (CFA) on islet beta cell apoptosis in preventing diabetes in non-obese diabetic (NOD) mice, and the influence on apoptotic related-gene expression. METHODS: Four-week-old female NOD mice were randomly divided into Group CFA (n=5) and Group saline (NS) control (n=5). Mice in Group CFA were injected in the hind footpad with 50 microL CFA and mice in Group NS with 50 microL NS. Blood sugar was monitored and diabetes was diagnosed if blood sugar was higher than 11.1 mmol/L for 2 continuous days in the NOD mice. The mice were sacrificed when diagnosed as diabetes or at 30 weeks of age. Pancreatic sections were made for: evaluation of insulitis severity with HE staining; counting of apoptotic beta cells with the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling (TUNEL) method, and ABC immunohistochemical double labeling; counting of Fas, FasL and Bcl-x positive cells respectively with ABC immunohistochemical method. RESULTS: By 30 weeks of age, none of the 5 CFA-treated mice, compared with 3 of the 5 control mice, had developed diabetes. The insulitis score was lower (1.820+/-0.962 vs. 3.020+/-1.040, P<0.05), the rates of apoptotic beta cells, Fas positive cells and FasL positive cells were lower [(10.2+/-2.8)% vs. (15.9+/-6.5)%, (54.9+/-14.5)% vs. (75.7+/-12.9)%, (20.3+/-10.4)% vs. (27.9+/-12.0)%, P<0.05), and the Bcl-x positive cell rate was higher [(74.9+/-10.7)% vs. (66.0+/-18.3)%, P<0.05] in the CFA-treated group than those in the NS-treated group respectively. CONCLUSION: CFA may inhibit beta cell apoptosis in NOD mice by regulating Fas, FasL and Bcl-x expression on cells within islets.

Animals↗

[The effects of endoscopic sinus surgery on nasality and nasal patency].

OBJECTIVE: The purpose of this study was to describe the changes of resonance characteristics of the nasal cavity (including nasal sinuses) and nasal airway resistance (NAR) after endoscopic sinus surgery (ESS), through objective measurement of nasality and NAR before and after ESS. METHOD: Sixty- eight patients received the examinations of nasality and NAR using Nanometer and Atmos Rhinomanometry before and after ESS separately. RESULT: The nasality of patients with type III and type II stage 2, stage 3 chronic sinusitis was obviously improved ( P <0. 05), but still below the normal range 1 month after ESS. The nasality didn't recover to the normal level 3 months postoperatively. However the total NAR apparently decreased 1 months after ESS ( P <0. 01) and returned to normal 3 months postoperatively. Nasality and the total NAR of patients in type II stage 1 turned to normal 1 month after ESS. There are no distinctive changes in nasality and total NAR of type I stage 1 patients. CONCLUSION: The total NAR significantly decreased close to normal among the patients with severe sinus or/and nasal lesions after ESS, however nasality continued aberrant for a relatively long period. It is suggested that nasality can't be ameliorated immediately after ESS. On the contrary, it is possible to bring some undesirable effects to the professional voice users, such as announces, for the changed resonance characteristics of the nasal cavity due to the excessive destruction of its normal structure.

Adolescent↗

Enantioselective sensing of chiral amino acids by potentiometric sensors based on optical active polyaniline films.

A novel enantioselective potentiometric sensor was constructed based on optical active polyaniline (PAn) films. The sensor with high stability showed discrimination behavior toward one isomer of racemic phenylalanine (Phe). The (-) or (+) PAn-based electrodes exhibited an excellent Nernstian slope of approximately 60 mV per decade for L-Phe or D-Phe, respectively. In addition, when the sensor was exposed to the mixture of enantiomers, the slope of the response changed along with their proportions, which would be employed as an index of the enantiomeric purity of the mixture. At last, the mechanism of chiral discrimination for Phe was discussed.

Aniline Compounds↗

One-color two-photon mass-analyzed threshold ionization spectroscopy of ethyl bromide through a dissociative intermediate state.

Mass-analyzed threshold ionization (MATI) spectra of ethyl bromide were obtained using one-color two-photon ionization through a dissociative intermediate state. Accurate values for the adiabatic ionization energy have been obtained, 83099+/-5 and 85454+/-5 cm(-1) for the X1 2E and X2 2E states of the ethyl bromide cation, respectively, giving a splitting of 2355+/-10 cm(-1). Compared with conventional photoelectron data, the two-photon MATI spectrum exhibited a more extensive vibrational structure with a higher resolution, mainly containing the modes involving the dissociation coordinate. The observed modes were analyzed and discussed in terms of wave packet evolving on the potential-energy surface of the dissociative state.

Journal Article↗

The properties of ACh-induced BK currents in guinea pig type II vestibular hair cells.

Molecular biological studies have demonstrated that both muscarinic receptor subtypes and nicotinic receptor subunits were located in mammalian vestibular sensorineural epithelium. However, the functional roles are still unclear, with the exception of the well-known alpha9-containing nicotinic ACh receptor (alpha9nAChR). In this study, the properties of acetylcholine (ACh)-induced currents were investigated by whole-cell patch clamp technique in isolated type II vestibular hair cells (VHCs II) of guinea pig. VHCs II displayed a sustained, non-inactivating current when extracellular application of ACh. ACh-induced currents restored gradually and it took about 60 s to get a complete recovery. ACh-induced current was not affected by extracellular Na(+), but strongly affected by extracellular K(+) and Ca(2+). Depletion of the intracellular Ca(2+) stores by intracellular application of inositol 1,4,5-trisphosphate (IP3) or blocking of the release of intracellular Ca(2+) stores by intracellular application of heparin failed to inhibit this current. ACh-induced currents were inhibited by nifedipine, Cd(2+), tetraethylammonium (TEA), charybdotoxin (CTX), iberiotoxin (IBTX), atropine and d-tubocurarine (DTC), respectively, but not by apamin. In conclusion, ACh stimulates a large conductance, Ca(2+)-activated K(+) current (BK) in guinea pig VHCs II by activation of the influx of Ca(2+) ions, which is mediated by an ACh receptor that could not be defined to be the odd-number muscarinic receptor.

Acetylcholine↗

Expression of orexin receptors in the brain and peripheral tissues of the male sheep.

Orexins exert their effects through two specific receptors (OX1R and OX2R) that have been found mainly in the brain and also in peripheral tissues of rats and humans. Here, we demonstrate expression of mRNA encoding for ovine OX1R and OX2R in central and peripheral tissues of sheep. Gene expression for orexin receptors in the hypothalamus and the preoptic area was localised by in situ hybridisation. OX1R was detected in arcuate nuclei (ARC), median eminence (ME), the lateral hypothalamic nuclei and preoptic area (POA) and it was scattered along the third ventricle from the paraventricular (PVN) to the ventromedial hypothalamic nuclei (VMH). OX2R was localised in the PVN, ARC, ME, ventral VMH and a small region of the ventral POA. Gene expression for OX1R and OX2R in central and peripheral tissues was analysed using quantitative real time RT-PCR. Both orexin receptor genes were expressed in the hypothalamus, POA, hippocampus, amygdala, olfactory bulb, pineal gland and recess and pituitary gland, whereas only OX1R mRNA was detected in the testis, kidney and adrenal gland. The expression of the genes for orexin receptors in this range of ovine tissues suggests roles for orexins in multiple physiological functions, with actions at both central and peripheral levels.

Animals↗

Anatomical analysis of an aye-aye brain (Daubentonia madagascariensis, primates: Prosimii) combining histology, structural magnetic resonance imaging, and diffusion-tensor imaging.

This report presents initial results of a multimodal analysis of tissue volume and microstructure in the brain of an aye-aye (Daubentonia madagascariensis). The left hemisphere of an aye-aye brain was scanned using T2-weighted structural magnetic resonance imaging (MRI) and diffusion-tensor imaging (DTI) prior to histological processing and staining for Nissl substance and myelinated fibers. The objectives of the experiment were to estimate the volume of gross brain regions for comparison with published data on other prosimians and to validate DTI data on fiber anisotropy with histological measurements of fiber spread. Measurements of brain structure volumes in the specimen are consistent with those reported in the literature: the aye-aye has a very large brain for its body size, a reduced volume of visual structures (V1 and LGN), and an increased volume of the olfactory lobe. This trade-off between visual and olfactory reliance is likely a reflection of the nocturnal extractive foraging behavior practiced by Daubentonia. Additionally, frontal cortex volume is large in the aye-aye, a feature that may also be related to its complex foraging behavior and sensorimotor demands. Analysis of DTI data in the anterior cingulum bundle demonstrates a strong correlation between fiber spread as measured from histological sections and fiber spread as measured from DTI. These results represent the first quantitative comparison of DTI data and fiber-stained histology in the brain.

Animals↗

Body reserves affect the reproductive endocrine responses to an acute change in nutrition in mature male sheep.

Metabolic status is a powerful regulator of reproductive activity, but the metabolic mediators involved and the relationships between fat reserves, food intake and the systems that control reproduction are not fully understood. In this study with mature male Merino sheep, we tested whether the effect of an acute nutritional stimulus on pulsatile LH secretion depended on body condition. Two groups of rams ("Fat" and "Lean") were fed differentially for 4 months to achieve high or low levels of body mass and body condition score. Half of each group was then assigned to be fed either their maintenance requirement or twice their maintenance requirement and, 7 days later, plasma samples were collected every 20 min for 24 h. All samples were used for the analysis of LH pulses and pooled samples were used for the measurement of metabolic hormone concentrations. In the rams that were fed the maintenance diet, the frequency of LH pulses was similar for the Fat and Lean groups, but plasma concentrations of leptin and insulin were significantly higher in the Fat group than in the Lean group. Following an acute increase in food intake, plasma concentrations of insulin were significantly increased in both Fat and Lean rams, but plasma leptin concentrations were increased only in Fat rams and LH pulse frequency was increased only in Lean rams. We concluded that the secretion of LH and leptin, but not insulin, is differentially influenced by nutritional status and body condition and that the role of leptin in the central regulation of the GnRH-LH system is probably permissive.

Animal Nutritional Physiological Phenomena↗

Methylation-associated silencing of death-associated protein kinase gene in laryngeal squamous cell cancer.

OBJECTIVES/HYPOTHESIS: Death-associated protein kinase (DAPK) is a Ca/calmodulin-regulated Ser/Thr kinase that functions as a positive mediator of programmed cell death. It has been found that DAPK gene is frequently inactivated by its promoter hypermethylation in some cancers and tumor cell lines. However, it is not clear whether promoter hypermethylation of DAPK gene exists in laryngeal squamous cell cancer (LSCC). The aim of this study was to investigate the promoter methylation status of the DAPK gene in LSCC and the effect of 5-Aza-2'-deoxycytidine (5-Aza-CdR), a demethylating agent, on Hep-2 cells, a human laryngeal cancer cell line, and on xenografts of Hep-2. METHODS: Methylation-specific polymerase chain reaction (PCR) and reverse-transcription PCR techniques were used to determine the promoter methylation status and mRNA expression of DAPK gene in LSCC. Furthermore, Hep-2 cells in vitro and in vivo were treated by 5-Aza-CdR to explore the effect of demethylating agents on DAPK mRNA expression and tumor growth. RESULTS: Hypermethylation of DAPK gene promoter was found in 39 (67.2%) of 58 LSCC samples. There was no significant difference in the promoter hypermethylation rate among the samples of different histologic grades or samples from patients with different T stages. However, there was significant difference in methylation status of DAPK gene between the samples from patients in N0 stages and those from patients in N1 stages. No promoter hypermethylation of DAPK gene was found in any of the five normal laryngeal tissue samples. DAPK mRNA expression was not detected in tumor specimens with promoter hypermethylation. On the contrary, DAPK mRNA expression was observed in the unmethylated tumor specimens, specimens from tissues adjacent to the tumor, and normal laryngeal tissues samples. Promoter hypermethylation of DAPK gene was found, and no DAPK mRNA expression was detected in Hep-2 cells. DAPK mRNA expression in Hep-2 cells and xenografts could be restored by treating cells and xenografts with 5-Aza-CdR. The tumors' xenografts, induced by way of Hep-2 cell injection in nude mice treated with 5-Aza-CdR, were obviously smaller than those in nude mice treated with phosphate-buffered saline. CONCLUSIONS: Abnormal loss of DAPK expression could be associated with aberrant promoter region methylation in the LSCC. 5-Aza-CdR may slow the growth of Hep-2 cells in vitro and in vivo by reactivating tumor suppressor gene DAPK silenced by de novo methylation.

Adult↗

[Relationship between the expression of tenascin C and TGF-beta1 in human nasal polyp tissues].

OBJECTIVE: To explore the mechanism underlying the increased expression of tenascin C (TNC) in human nasal polyp tissues. METHODS: The method of immunohistochemistry was used to detect the protein expression of TNC and transforming growth factor-beta1 (TGF-beta1) and their relationship in nasal polyp tissues. The cell culture, real-time RT-PCR and in situ ELISA techniques were employed to investigate the effect of TGF-beta1 and eosinophils on the TNC mRNA and protein expression in BEAS-2B immortalized human bronchial epithelial cells. RESULTS: (1) TNC and TGF-beta1 protein expression were up-regulated in nasal polyp tissues. TNC expression level was associated with the number of TGF-beta1 positive cells (r = -0.58, P < 0.01) and TGF-beta1 positive eosinophils (r = -0.61, P < 0.01); (2) 1 ng/ml and 10 ng/ml TGF-beta1 induced TNC mRNA expression by 7.20 +/- 3.43-fold and 22.48 +/- 5.35-fold (P < 0.01) in BEAS-2B cells after 4 h stimulation respectively. The fluorescence intensity of TNC protein expression was 129. 50 +/- 47.42 and 151.20 +/- 48.36 after 24 h stimulation respectively. The protein expression was significantly increased compared with that without stimulation (60.60 +/- 38.53, P < 0.05); (3) Coculture BEAS-2B cells and eosinophils at 2:1, 1:1 and 1:2 ratio, TNC mRNA expression was induced by 4.90 +/- 1.40-fold, 5.48 +/- 1.60-fold and 4.78 +/- 1.32-fold (P < 0.01) in BEAS-2B cells after 4 h coculture respectively. The fluorescence intensity of TNC protein expression was 128.75 +/- 44.15, 142.33 +/- 29.06 and 131.33 +/- 20.87 after 24 h coculture respectively. The protein expression was significantly increased compared with that without eosinophils coculture (59.40 +/- 10.14, P < 0.05). Treatment with neutralizing antibody to TGF-beta1 significantly inhibited eosinophil-induced BEAS-2B cells TNC expression in a dose-dependent manner (P < 0.05). CONCLUSION: TGF-beta1 and eosinophils can induce TNC expression in airway epithelial cells. The effect of eosinophils is partially mediated through TGF-beta1. Up-regulated expression of TNC in nasal polyp tissues is related to eosinophil-derived TGF-beta1.

Adolescent↗

[Inhibitory effect of 5-Aza-2'-deoxycytidine on human nasopharyngeal carcinoma xenograft in nude mice].

BACKGROUND & OBJECTIVE: 5-Aza-2'-deoxycytidine (5-Aza-CdR) is an inhibitor of DNA methyltransferase; it may reactivate methylated antioncogene, therefore, inhibit the growth of cancer cells. This study was to observe the inhibitory effect of 5-Aza-CdR on the growth of human nasopharyngeal carcinoma (NPC) cells and xenografts in nude mice, explore the possible mechanisms, and search for new treatment target of NPC. METHODS: NPC cell line CNE cells were treated with 5-Aza-CdR; the methylation status of death-associated protein kinase (DAPK) gene was evaluated by methylation-specific polymerase chain reaction (PCR). The model of human NPC xenograft in nude mice was constructed and treated with 5-Aza-CdR; the xenograft growth in nude mice was observed, and the mRNA and protein expression of DAPK was detected by reverse transcription-PCR (RT-PCR) and immunohistochemistry. RESULTS: No expression of DAPK mRNA was found in CNE cells and the xenografts in nude mice without treatment of 5-Aza-CdR. After treatment, the expression of DAPK mRNA in CNE cells and the xenografts was increased along with the increasing concentration of 5-Aza-CdR; the growth of CNE cells and the xenografts in nude mice were obviously inhibited, and the methylated DAPK gene was reactivated. Four weeks after treatment, no significant difference was found in body weight of nude mice between 5-Aza-CdR group and control group [(22.35+/-2.02) g vs. (21.68+/-2.14) g, t=0.011, P>0.05]; the volume of xenografts was significantly smaller in 5-Aza-CdR group than in control group [(195.32+/-27.57) mm(3) vs. (343.67+/-23.08) mm(3), t=10.11, P<0.01]. CONCLUSION: 5-Aza-CdR may reactivate antioncogene silenced by de novo methylation, therefore, inhibit the growth of CNE cells in vivo and in vitro.

Animals↗

[The expressions of survivin and VEGF in squamous cell carcinoma of larynx and the correlation between the two marks].

OBJECTIVE: To study the expressions and biological behavior of Survivin and VEGF in squamous cell carcinoma of larynx (LSCC) and the correlation between Survivin and VEGF. METHOD: The expressions of Survivin and VEGF in LSCC tissues of 40 cases and normal mucosa of larynx tissues of 5 cases were studied by immunohistochemical staining. RESULT: The expressions of Survivin and VEGF in LSCC tissues were higher than those in normal mucosa of laryngeal cavity (P <0.01). The expressions of the two marks in LSCC with the metastasis of lymph nodes were higher than those without metastasis (Survivin: P <0.05, VEGF: P <0.01). Age and sex did not change the expressions obviously (P > 0.05). There was a negative correlation between T-stage and Survivin expressions (P < 0.05). There was also a negative correlation between T-stage and VEGF expressions (P < 0.05). But, there was a positive correlation in staining intensity between Survivin and VEGF (r = 0.676, P < 0.01). CONCLUSION: Significant correlation between Survivin/VEGF expression and T-stage (P <0.05), lymph node metastasis (P <0.05) and prognosis (P <0.01) was revealed in squamous cell carcinoma of larynx. The high expression of it suggests bad prognosis. The up-regulate of the two genes suggest that they play important roles in the formation and metastasis of LSCC.

Aged↗

Predicting pregnancy-induced hypertension with dynamic hemodynamics.

AIM: To study dynamic changes in the hemodynamic parameters in pregnant women during different weeks of gestation and to comprehend changes to the cardiovascular system in normal pregnant women and in patients with pregnancy-induced hypertension (PIH), with the object of finding predictors of pregnancy-induced hypertension. METHODS: Radialis artery pulse waves of 132 pregnant women were examined from 10 weeks of gestation onward, and the subjects' hemodynamics were examined every 4 weeks. RESULTS: In the women with PIH hemodynamic changes occurred earlier than the onset of disease and even presented in early pregnancy; there might be another mode, and there were factors disturbing the blood pressure modulating mechanism. CONCLUSION: The prediction of PIH from the dynamic changes in hemodynamic parameters has significant implications for clinical practice.

Adult↗