血液分离胶的制备研究

目的 :对血液分离胶的制备进行研究。方法 :用天然橡胶和特效触变剂等原料制备具有触变性的凝胶 ,研究该凝胶分离血清的较优组成。结果 :血液分离胶的较优组成是天然橡胶 12 .8%、特效触变剂 2 8.0 %和溶剂汽油 5 8.2 %。结论 :所制备的血液分离胶具有制备容易、分离效果好和成本较低等优点。     

升丹制剂对小鼠机械性创面微循环影响的实验研究

目的 通过不同浓度的升压制剂对创面微循环影响来控制其对创面愈合的作用机制。方法 应用彩色病理图文分析系统,分析创面微血管增生数、扩张度及微血栓数。结果 在造模后３天、７天,实验且数值均显著高于对照组。结论 升丹制课题可以和改善创面微循环,减少微血栓,增加创面营养和血供,有利创面愈合。     

三种烤瓷贴面牙体预备的临床修复效果评价

:【目的】评价 3种烤瓷贴面 (PLV)牙体预备的近期临床效果。【方法】根据贴面形态和覆盖牙体范围将PLV牙体预备分为I型、L型和U型 3种 ,用于着色牙和前牙间隙、缺损等修复 ,PLV采用长石质PLV瓷系统制作 ,双重固化树脂粘结系统粘结 ,观察 6～ 2 2个月 ,考察 3种牙体预备类型的适应证、最终美学效果、粘接强度及牙本质敏感性等。【结果】 35例 2 0 3个瓷贴面修复后形态、颜色满意 ,美学效果佳 ;无脱落 ,仅局部崩折 2例 ,近期粘接效果满意 ;备牙时牙本质暴露率达 95 16 % ,粘固后牙本质过敏症状不同程度缓解。【结论】合理选择适应证、足够的牙体制备及高强度树脂粘结系统 ,可保证 3种牙体预备类型均能使PLV获得良好的外形、满意的颜色及可靠的临床近期粘接强度 ;但牙本质过敏问题应予重视     

茯苓多糖颗粒剂的研制及质量检测

以提取的茯苓多糖为主要原料,制成颗粒剂保健品,并拟定质检项目其进行定性、定量检测。工艺简单易行,具有较好的治疗、保健功效。     

钙增敏剂MCI-154对内毒素休克大鼠左心室肌原纤维ATP酶活性的影响

目的　研究钙增敏剂MCI 15 4对内毒素休克大鼠左心室肌原纤维ATP酶活性的影响。方法　利用心室肌原纤维制备 ,测定其在不同钙浓度的激活液中的ATP酶活性。结果　内毒素休克组心肌肌原纤维在不同pCa(-log[Ca2 +] )溶液中的ATP酶活性及最大ATP酶活性均明显低于假休克组 ,ATP酶 pCa曲线向右移位约 0 .35个pCa单位 ,曲线的中位值pCa50 (产生 5 0 %最大ATP酶活性所对应的pCa)明显降低。 5×10 -5mol/L甲腈吡酮对上述异常无明显的纠正作用。内毒素休克大鼠心室肌原纤维经含 1× 10 -5mol/L的MCI 15 4的激活液处理后 ,各pCa点ATP酶活性及最大ATP酶活性均明显增加 ,显著高于内毒素休克组和甲腈吡酮组 ;ATP酶 pCa曲线向左移位约 0 .4个pCa单位 ,pCa50 值增加 ,显著高于内毒素休克组和甲腈吡酮组值 ,与假休克组值无明显差别。结论　内毒素休克后 ,心肌肌原纤维活力下降 ,ATP酶活性降低 ;钙增敏剂MCI 15 4可通过增加心肌收缩蛋白对钙的敏感性而提高心肌肌原纤维活力 ,增加ATP酶活性     

黄参方剂诱导胃癌癌前病变细胞凋亡和影响BCL—2蛋白表达的研究

目的：探讨黄参方剂对胃癌癌前病变细胞凋亡及相关基因表达的影响。方法：将７２例胃癌癌前变患者随机分为２组,治疗组３７例,口服黄参方剂６０ｍｌ／ｄ;对照组３５例,口服维酶素片１２片／天,疗程２月。治疗后胃镜同一部位取材,检测治疗前后细胞凋亡指数和ＢＣＬ－２蛋白的表达。采用原位末端标记法（ＴＵＮＥＬ）检测细胞凋亡,采用免疫组化检测ＢＣＬ－２蛋白的表达。结果：黄参方剂组服药前后细胞凋亡指数分别为（１９．８     

Ischaemia induced alternans of action potential duration in the intact-heart: dependence on coronary flow, preload and cycle length

Clinical and experimental evidence relate action potential duration(APD) alternans to ischaemic heart disease and ventricular arrhythmias.The present investigation was performed to study the quantitativerelationship between APD alternans and the degree ofischaemia,loading conditions and cycle length (CL) in an intact heart. Monophasic action potentials (MAP) were simultaneously recordedby contact electrodes from two left (LV) undone right ventricular(RV) sites in 20 Langendorff-perfused rabbit hearts. The preparationswere subjected to global ischaemia at flow rates ranging from40% of normal flow to complete cessation of flow. Pacing wasperformed at either constant or regularly changing CL. The magnitudeof APD alternans was expressed as beat-to-beat differences inaction potential duration of two consecutive MAPs. During normalper fusion, neither very fast pacing at a CL of 200 ms nor periodicalrate switches resulted in persistent APD alternans. Pacing ata constant CL of 800 ms did not induce A PD alternans at completecessation of flow for 6 min. However, alternans developed progressivelyat a constant CL of 400 ms after 2.8±0.3 min of completeischaemia at the pre-loaded LV, andafter 4.6±0.4 minat the unloaded RV (P<0.01). The reduction of preload atthe LV from 15 to 5 mmftg end-diastolic pressure delayed developmentof APD alternans from 2.8±0.3 min to 4.3±0.4 min(P < 0.05) at 400 ms CL. Following graded under per fusionof 40%, 20% and 10% of initial flow, persistent APD alternansdeveloped in relation to the degree of flow reduction and increasedprogressively with duration ofischaemia. APD alternans at theLV always preceded the onset of APD alternans at the RV. Inexperiments with identical flow rates the shortest CL of 200ms resulted in the greatest and earliest initiation of APD alternanscompared to the longer CL (P<0.01, P<0.001). An increasein CL from 400 to 800 ms immediately abolished APD alternans,generated by the shorter CL, at any time during the 6 min periodof complete ischaemia. Similarly, increasing the cycle lengthfrom 200 or 400 to 600 ms eliminated APD alternans up to 6 minof ischaemia and significantly reduced its magnitude between7 and 10 min within a few beats. We conclude that persistent APD alternans is a characteristicfinding in the rabbit heart during global ischaemia. It is asensitive parameter of the severity of ischaemia and dependson the degree and duration of ischaemia as well as on the preload.The CL appears to have an independent effect on the generationof APD alternans, which is functionally separate from the effectof CL on the ischaemic burden. An eventual impact of these observationscould be the application of APD alternans as a diagnostic toolin electrophysiological examinations of myocardial ischaemiain experimental and clinical settings.     

Effects of adenosine on electrical activity of isolated guinea pig hearts

Summary Negative chronotropic and dromotropic effects of adenosine seem to be responsible for its antiarrhythmic action on supraventricular tachyarrhythmias. To further characterize the effects of adenosine on supraventricular arrhythmias heart rate, conduction, refractoriness, the time to steady-state of AV-nodal conduction slowing and of sinus rate reduction were evaluated.Changes of heart rate, conduction intervals and effective refractory periods were determined by the use of a high-resolution ECG recording technique in isolated guinea pig hearts perfused by the method of Langendorff.Adenosine in concentrations of 3 and 10 M reduced sinus rate and prolonged AV-nodal conduction significantly, while intraventricular and His bundle conduction were not altered. The maximal effect of adenosine on the sinus node and AV nodal conduction occurred after 636±109 and 111±35 (mean±SE) beats, respectively.During programmed stimulation at a cycle length of 250 ms, adenosine reduced atrial ERP in a dose-dependent manner. At cycle lengths of 170 and 200 ms, adenosine increased the atrial ERP at 3 M, and then progressively shortened the ERP at higher doses. At all adenosine concentrations used, the usual rate-dependent adaption in ERP was suppressed.These observations explain the efficacy of adenosine against supraventricular tachyarrhythmias where the AV-node forms a part of a reentrant circuit. Adenosine shortened the atrial ERP, but at high pacing rates also led to a relative prolongation of the atrial ERP as the rate-dependent adaption was suppressed. These opposite effects of adenosine may explain earlier contradictory findings of its action on atrial arrhythmias.     

GABA-mediated synaptic transmission in neuroendocrine cells: a patch-clamp study in a pituitary slice preparation

Patch-clamp recording techniques were applied to thin slices of the rat pituitary gland in order to study synaptic transmission between hypothalamic nerve terminals and neuroendocrine cells of the intermediate lobe. Inhibitory postsynaptic currents (IPSCs) could be evoked by electrical stimulation of afferent neuronal fibres in the surrounding tissue of the slice. The IPSCs could be evoked in an all-or-nothing mode depending on the stimulus intensity, suggesting that single afferent fibres were stimulated. They had a chloride-dependent reversal potential and were blocked by bicuculline (K _d=0.1 M), indicating that they were mediated by -aminobutyric acid A (GABA_A) receptors. In symmetrical chloride solutions the current/voltage relation of the IPSC peak amplitudes was linear. The IPSCs were characterized by a fast (1–2 ms) rise time and a biexponential decay, with time constants of 21±4 ms and 58±14 ms at a holding potential of –60 mV (n=6 cells). Both decay time constants increased with depolarization in an exponential manner. Spontaneously occurring IPSCs had a time course that was similar to that of evoked IPSCs. These miniature IPSCs, recorded in 1 M tetrodotoxin, displayed an amplitude distribution that was well fitted by single Gaussian functions, with a mean value of its maxima of 18.1±2.3 pA (n=4 cells). Amplitude histograms of evoked IPSCs were characterized by multiple peaks with a modal amplitude of about 18 pA (n=6 cells). These findings indicate the quantal nature of GABAergic synaptic transmission in this system, with a quantal conductance step of about 280 pS. Single-channel currents underlying the IPSCs were studied by bath application of GABA to outside-out patches excised from intermediate lobe cells. Such GABA-induced currents revealed two conductance levels of 14 pS and 26 pS. In conclusion, GABAergic synaptic transmission in neuroendocrine cells of the pituitary has properties that are quite similar to those observed in neurones of the central nervous system.     

Cytologic diagnosis of cavernous hemangioma of the liver with fine-needle biopsy.

We present the cytopathologic findings in seven cases of cavernous hemangiomas of the liver diagnosed by direct "squash" smears made on tissue obtained through image-guided fine-needle biopsy. The diagnosis in each case was confirmed histologically. Utilizing this simple cytologic technique, the morphologic findings in these common hepatic lesions are as accurate and diagnostic as histologic examination.