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排序方式: 共有673条查询结果,搜索用时 15 毫秒
1.
2.
INVOLVEMENT OF NON-NMDA AND NMDA RECEPTORS IN GLUTAMATE-INDUCED PRESSOR OR DEPRESSOR RESPONSES OF THE PONS AND MEDULLA 总被引:1,自引:0,他引:1
SY Chen WC Wu CJ Tseng JS Kuo CY Chai 《Clinical and experimental pharmacology & physiology》1997,24(1):46-56
1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperito-neally with urethane (400 mg/kg) and a-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50–100nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50–100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50–100 nL) and AMPA (0.2 mmol/L, 50–100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain. 相似文献
3.
根据胜利黄岛原油的性质,在筛选了几十种破乳剂的基础上,选择了酚醛树脂和环氧环烷,环氧乙烷的嵌段共聚物作破乳剂,探讨了破乳剂组成对原油脱水,脱盐以及界面张力的影响,通过静态脱盐,脱水试验,得到了适合黄岛原油的最佳破乳剂组成。 相似文献
4.
5.
对1986年-1990年《江西医学院学报》的引文进行了数理统计与分析,定量描述其引文的类型,文种,时序以及在被引期刊中的分布。测定了该刊引用文献的半衰期与核心期刊,并对论著及著者分布作了分析。 相似文献
6.
豚鼠中耳(听泡)内滴入0.5%、1%、2%环丙沙星与庆大霉素滴耳液7天或21天,借助光镜和扫描电镜观察内耳的显微和超微结构变化。结果证明环丙沙星对内耳没有明显的毒性作用。庆大霉素则使耳蜗明显受损,以底回为重,Corti’s器外毛细胞坏死较多,内毛细胞及支持细胞病变较轻。位觉斑耳石脱落,毛细胞纤毛粘连、脱落。壶腹嵴中央区纤毛也缺失。本实验对客观评价环丙沙星对内耳的作用及临床使用提供了形态学资料。 相似文献
7.
Jennifer C. Chen Katrina L. Schmid Brian Brown Marion H. Edwards Bibianna SY Yu John KF Lew 《Clinical & experimental optometry》2003,86(5):323-330
Purpose: Caucasian children with myopia have elevated response accommodative vergence to accommodation (AC/A) ratios. The purpose of this study was twofold: to determine if response AC/A ratios vary with refractive error and with myopic progression rate in Hong Kong Chinese children, and to determine the effect of beta‐adrenergic antagonism with topical timolol application on AC/A ratios. Methods: Thirty children aged eight to 12 years participated in the study. All refractive errors were corrected with spectacle lenses. Accommodative responses were measured using a Shin‐Nippon autorefractor and concurrent changes in vergence were assessed using a vertical prism and a Howell‐Dwyer card at three metres and 0.33 metre. Accommodative demand was altered using plus or minus two dioptre lenses and lens‐ and distance‐induced response AC/A ratios were calculated. Measurements were repeated 30 minutes after the instillation of topical timolol maleate (0.5 per cent). Results: AC/A ratios appeared higher in progressing myopic children but the difference was not statistically significant. Timolol application reduced accommodative convergence (AC) in the stable myopes (reduction = ‐3 ± 1.14A) but not in the emmetropes (0.69 ± 0.9P) or progressing myopes (0.16 ± 0.43A) and this difference between refractive groups was statistically s ignificant (F2,27= 3.766; P= 0.036). However, timolol did not produce a significant change in the accommodative response to positive or negative lenses or response AC/A ratios. Conclusions: We did not find that AC/A ratios in myopic Chinese children were elevated and therefore, it is unlikely that elevated AC/A ratios are responsible for the high levels of myopia that occur in Hong Kong. The finding that timolol reduced AC in the stable myopes suggests that the autonomic control of accommodative convergence in these children may be different from that in emmetropic children and those with progressing myopia. 相似文献
8.
Kung FT; Chen WJ; Chou HH; Ko SF; Chang SY 《Human reproduction (Oxford, England)》1997,12(8):1649-1653
We report a rare case of early-stage endometrial adenocarcinoma in a 22
year old nullipara with polycystic ovaries undergoing conservative
treatment. Pretreatment evaluation including tumour grade, depth of
myometrial invasion, tumour size, hormone receptor status and flow
cytometric analysis indicated a favourable prognosis. The patient underwent
repeat endometrial curettage and a 6 month period of therapy with megestrol
acetate and tamoxifen. A combination contraceptive pill was then prescribed
to ensure withdrawal of the menstrual cycle thereafter. Now, 1 year after
the last curettage, there is no evidence of disease. During the treatment
period, hysteroscopy allowed for a more precise approach in panoramically
examining the tumour nest in the endometrial cavity, and the subsequent
endometrial response to hormone therapy. Laparoscopy using bulldog clamps
applied to the isthmic portion of the Fallopian tubes prevented i.p. spread
of endometrial tissue from retrograde regurgitation during hysteroscopy.
Laparoscopic ovarian electrocautery resulted in the reduction of abnormal
hypervascularization on the surface of polycystic ovaries postoperatively
but caused a peri-ovarian adhesion complication. It is interesting that
this case posed a unique opportunity to demonstrate the tumour regression
under the assistance of laparoscopy and hysteroscopy.
相似文献
9.
Yoshida A; Araki Y; Motoyama M; Kim SY; Sung H; Araki S; Miura K; Shirai M 《Human reproduction (Oxford, England)》1997,12(11):2499-2503
The objective of this study was to determine whether or not abnormalities
in the autosomal structure of the male partner have any influence on
fertilization and early embryo development after intracytoplasmic sperm
injection (ICSI). Thirty-seven couples in whom the male partners were
examined by the same andrologist were included in this study. Six couples
(group I) in whom the male partner possessed autosomal structural
abnormality underwent seven ICSI cycles. As a control group, 31 couples
(group II) in which the male partner was karyotypically normal underwent 41
ICSI cycles. Although the normal fertilization rates seen in group I were
significantly higher than those in group II (P < 0.05), there was no
significant difference in the cleavage rates between the two groups. We did
not perform the analysis of the female partner's chromosomes, but we
surmise that structural autosomal abnormalities in the male partner do not
adversely influence fertilization at ICSI and early development of embryos.
相似文献
10.
成人下凳骨第三磨牙阻生关系的研究 总被引:1,自引:0,他引:1
目的 观测成人下颌骨第三磨牙的阻生关系。方法 根据吴氏《人类骨骼测量方法》中规定的年龄估计及性别鉴定的标准,观测成人颌骨的形态结构。结果 302个下颌骨标本的观察结果为,男女混合阻生率为10.60%,女性阻生率高于男性,肉眼见无第三磨牙萌出者106例,经X线拍片验证,5例有埋没牙存在,故实际第三睡缺如率为33.44%。从测量数据可见阻生组(无第三磨牙组)的第二磨牙后间隙、下颌斜长、下颌体长及髁突间宽均较正常组小。结论 无第三磨牙可能是人类进化过程中,下颌骨与牙齿均衡退化的结果,而阻生是人类进化从有第三磨牙向第三磨牙演化的过渡阶段。 相似文献