AIM: To explore the properties of the acetylcholine(ACh)-sensitive potassium channel in type Ⅱ vestibular hair cells(VHCs Ⅱ) in mice saccular macula and the modulation effect of calcium ions.METHODS: Under the whole-cell patch mode,the pharmacology properties of ACh-sensitive potassium channel and the modulation of calcium ions on ACh-sensitive potassium channel were investigated.RESULTS: Following extracellular perfusion of ACh,VHCs Ⅱ displayed a slow and sustained outward current,which was sensitive to tetraethylammonium(TEA,5 mmol/L) and charybdotoxin(CTX,100 nmol/L),but not sensitive to 4-aminopyride(4-AP,15 ?mol/L).ACh-sensitive potassium current was inhibited by intracellular application of ethylene glycol-bis(B-aminoethylether)-N,N,N',N'-tetraacetic-acid(EGTA,5 mmol/L) and extracellular perfusion of Cd2+ and Ni2+,respectively.Intracellular application of heparin(8 g/L) failed to inhibit ACh-sensitive potassium current.CONCLUSION: Extracellular application of ACh activates the big conductance,calcium-dependent potassium current(BK) in VHCs Ⅱ of mice,which is potently modulated by extracellular Ca2+ ions.However,intracellular IP3-dependent Ca2+ ions release mechanism is not involved in the activation of the ACh-sensitive BK channel.

Wild Cordyceps sinensis strain was isolated from Mt. Batang in Yush District of Qinghai Province. Its optimal culture conditions were 1.5% Glucose, 1% malt extract, 1 peptone, 0.5% yeasts extract, pH6.0, temperature 23℃, 5—10% inoculum, vibration velocity 80—90r/min.

The relationship between hypermethylation of CpG islands in the promoter regions of O6-methylguanine DNA methyltransferase (MGMT) genes and laryngeal squamous cell carcinoma was explored. Methylation-specific PCR and semi-quantitative RT-PCR were used to study the promoter methylation and mRNA expression of the MGMT gene in laryngeal carcinoma tissues, tissues adjacent to the tumor and normal laryngeal tissues. Hypermethylation of MGMT gene was detected in 16 samples of 46 (34.8%) laryngeal squamous cell carcinoma samples. However, the MGMT hypermethylation was not detected in all tissues adjacent to the tumors and normal tissues. No significant difference in MGMT gene hypermethylation was found in samples with different histological grades (chi2 = 3.130, P = 0.077) or in samples from patients with different TNM status (chi2 = 3.957, P = 0.138). No expression of MGMT mRNA was detected in all hypermethylated laryngeal carcinoma tissues. The expression of MGMT mRNA was detected in all unmethylated laryngeal carcinoma tissues, tissues adjacent to the tumors and normal tissues. It suggests that MGMT gene promoter hypermethylation is associated with MGMT gene transcription loss in laryngeal carcinoma tissues and possibly plays an important role in carcinogenesis of laryngeal tissues.
Carcinoma, Squamous Cell/*genetics ; CpG Islands/genetics ; DNA Methylation ; DNA Repair ; Laryngeal Neoplasms/*genetics ; O(6)-Methylguanine-DNA Methyltransferase/*genetics ; Polymerase Chain Reaction/methods ; Promoter Regions (Genetics)/*genetics

Objective To investigate the regional cerebral stimulation after central analgesics nasal spray and its mechanism with pharmacological functional magnetic resonance imaging (phfMRI). Methods Eighteen healthy right-handed volunteers participated. Butorphanol tartrate nasal spray was used as the experiment agent. Ethological experiment was carried out to record the participants' subjective feeling and the onset time of the analgesics, followed by the functional MRI (fMRI) scan two weeks later. Block design was adopted. Two phases of fMRI scan were performed at 7 min and 25 min after the nasal spray, respectively. Participants were also given pain stimulation in the dorsum of hand during the fMRI scanning. The data were post-processed with Matlab 6.5 and SPM 2. Results ①Onset time of butorphanol tartrate was 15-35 min after nasal spray administration, which was consistent with its concentration-time curve. ②After nasal spray, activations were observed in the cerebral cortex, including frontal lobe (orbitofrontal gyrus, medial frontal gyrus, superior frontal gyrus), temporal lobe (insula, middle temporal gyrus, inferior temporal gyrus), parietal lobe (precuneal gyrus), limbic system (anterior cingulate gyrus, middle cingulate gyrus, hippocampus, parahippocampal gyrus);subcortical region (globus pallidus) and cerebellum (6-9 of cerebellar cortex, cerebellar peduncle, vermis). ③The number and activation intensity of the second phase were more obvious than those of the first phase (P<0.01). Conclusion The feasibility of phfMRI study on cerebral stimulation and the mechanism of nasal spray is demonstrated. The study of butorphanol tartrate further validates the main distribution of opioid receptors in the central nervous system and the possible mechanism of central analgesia.

Whole-cell patch clamp technique was performed on acutely isolated rat dorsal root ganglion (DRG) neurons to investigate the modulatory effect of caffeine on γ-aminobutyric acid (GABA)-activated currents (IGABA). The results showed that the majority of the neurons examined (97.4%, 113/116) were sensitive to GABA. 1-1000 μmol/L GABA activated a concentration-dependent inward current which manifested obvious desensitization. After the neurons were treated with caffeine (0.01-100 μmol/L) prior to the application of GABA (100 μmol/L) for 30 s, GABA-activated membrane currents were obviously inhibited. Caffeine shifted the GABA dose-response curve downward and decreased the maximum response to 57% without changing Kd value. These results indicate that the inhibitory effect is non-competitive. Theophylline showed a similar and stronger inhibitory effect on IGABA. The pretreatment with caffeine (10 μmol/L) inhibited IGABA, which was potentized by diazepam (1 μmol/L). Intracellular application of H-8 almost completely abolished the inhibitory effect of caffeine on IGABA. The present results suggest that caffeine may be able to antagonize the effect of presynaptic inhibition of GABA in primary afferent.

Objective:To explore more reliable standards for identifying vestibular hair cells of saccule and utricle prepared in studies with patch clamp technique under inverted phase contrast microscope. Method:The length and width of two types hair cells were measured besides the length of cilia,and all datas were analyzed statistically.Result:The width and length of cilia of two types hair cells in saccule and utricle from guinea pig were similar. The length of type Ⅰ was longer than that of type Ⅱ,SO the ratio between length and width was larger and the ratio of the length between cilia and cell body was small.Conclnsion:Two type'S hair cells of saccule and utricle from guinea pig may be distinguished through the ratio of cell body's length and width even the ratio of the length between cilia and cell body,besides the standards before.

OBJECTIVETo observe the effect of the extract of Ginkgo biloba (EGb761) and the components isolated from the extract named ginkgolide B (GB) against damage of glutamate in pretreatment modes so that determine their application value and approach.

METHODBased on glutamate-induced excitotoxicity to primary cultures from neonatal Sprague-Dawley (SD) rat hippocampal neuron, our experiment utilized trypan blue, TUNEL and LDH to study the effect of EGb761 and GB on neuron in different doses pretreatment modes, as well as to compare with the NMDA receptor uncompetitive antagonist-MK-801.

RESULTEGb761 and GB can recrease cell viability, reduce apoptosis rate and decrease LDH leakage in different degree and depended on dose in certain range. The maximal protection was achieved at a concentration of 100 mg x L(-1), 100 micromol x L(-1), but inferior to MK-801 (10 micromol x L(-1)). The protective effect of GB is superior to EGb761.

CONCLUSIONTreatment with EGb761 and GB could protect the neurons against glutamate-induced injury. The maximal protection of GB was achieved by pretreatment is superior to EGb761, so its precautionanary intervention to high-risk population could have more value.

Animals ; Animals, Newborn ; Cells, Cultured ; Dizocilpine Maleate ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Ginkgo biloba ; chemistry ; Ginkgolides ; chemistry ; pharmacology ; In Situ Nick-End Labeling ; L-Lactate Dehydrogenase ; metabolism ; Lactones ; chemistry ; pharmacology ; Neurons ; drug effects ; Neuroprotective Agents ; chemistry ; pharmacology ; Plant Extracts ; pharmacology ; Rats ; Rats, Sprague-Dawley

The relationship between hypermethylation of CpG islands in the promoter regions of O6methylguanine DNA methyltransferase (MGMT)genes and laryngeal squamous cell carcinoma was explored. Methylation-specific PCR and semi-quantitative RT-PCR were used to study the promoter methylation and mRNA expression of the MGMT gene in laryngeal carcinoma tissues, t issues adjacent to the tumor and normal laryngeal tissues. Hypermethylation of MGMT gene was detected in 16 samples of 46 (34.8 %) laryngeal squamous cell carcinoma samples. However, the MGMT hypermethylation was not detected in all tissues adjacent to the tumors and normal tissues. No significant difference in MGMT gene hypermethylation was found in samples with different histological grades (x2= 3. 130, P=0. 077) or in samples from patients with different TNM status (x2=3. 957, P=0. 138). No expression of MGMT mRNA was detected in all hypermethylated laryngeal carcinoma tissues. The expression of MGMT mRNA was detected in all unmethylated laryngeal carcinoma tissues, tissues adjacent to the tumors and normal tissues. It suggests that MGMT gene promoter hypermethylation is associated with MGMT gene transcription loss in laryngeal carcinoma tissues and possibly plays an important role in carcinogenesis of laryngeal tissues.

In order to explore the platform role and practicability of network teaching in the teaching and training of clinical blood transfusion. By building an "Internet+APP" teaching and training management platform, this research develops personalized teaching and training courses and assessment plans for different groups such as interns, trainees and on-the-job staff in the blood transfusion department, so as to achieve time-saving and high-efficient training results. The results showed that the interns' assessment scores were all up to standard, with more than 90 points accounting for 66% and 80-90 points accounting for 34%. The assessment scores of the trainees and on-the-job personnel were above 90 points, which showed that they had significant improvement of their professional level. The teaching resources of this teaching mode are stable, centered on the trainees, free from traditional time and space constraints, high-efficient, time-saving, and easy to accept.

OBJECTIVE: To explore more reliable standards for identifying vestibular hair cells of saccule and utricle prepared in studies with patch clamp technique under inverted phase contrast microscope. METHOD: The length and width of two type's hair cell's were measured besides the length of cilia, and all datas were analyzed statistically. RESULT: The width and length of cilia of two types hair cells in saccule and utricle from guinea pig were similar. The length of type I was longer than that of type II, so the ratio between length and width was larger and the ratio of the length between cilia and cell body was small. CONCLUSION Two type's hair cells of saccule and utricle from guinea pig may be distinguished through the ratio of cell body's length and width even the ratio of the length between cilia and cell body, besides the standards before.
Animals ; Cell Shape ; Guinea Pigs ; Hair Cells, Vestibular ; cytology ; Microscopy, Phase-Contrast ; Patch-Clamp Techniques ; Saccule and Utricle ; cytology