Validity of a hinged constant force probe and a similar, immobilised probe in untreated periodontal disease

The validity of a hinged constant force probe (0.25 N) was compared with that of a similar but immobilised instrument, using the same interchangeable tip for both (0.64 mm diameter; 2 mm divisions). 60 sites were measured on teeth which were extracted subsequently, in patients with untreated periodontal disease, and the connective tissue attachment level was used as validity criterion. The clinical measurements of both probes correlated well with each other, but they differed significantly from the post-extraction connective tissue attachment level measurements, indicating a point 1.2 mm coronally to this, on average. A companion investigation of intra-operator probing depth reproducibility with the 2 probes, was undertaken in 14 patients, at 2 visits separated by 1 week in each case. All patients had untreated periodontal disease. A difference between probes was found at the first visit, but not at the second; the immobilised probe showed a difference between visits, reducing mean probing depth slightly at the second; when the immobilised probe was used first, there was a difference between probes. Further analysis of the results indicated that there was greatest agreement between probes when the constant force probe had been used before the immobilised probe at the second visit. The results suggested that these probes indicated a point above the connective tissue attachment level, related to pocket morphology, and that there was a moderate learning effect due to operator use of the constant force probe, which modified use of the immobilised probe.     

Chronotropic and inotropic effects of histamine in developing chick heart: differential mechanisms before and after hatching

Chronotropic and inotropic effects of histamine were examined in isolated atrial and ventricular preparations from embryonic and hatched chicken hearts. Histamine produced positive chronotropic and inotropic responses both in embryonic and hatched hearts. The responses to histamine in middle embryonic myocardia, which were observed in the micromolar range, were antagonized by H₂ antagonists but not by H₁, H₃ antagonists and propranolol. Isobutylmethylxantine, an inhibitor of phosphodiesterase, produced a leftward shift of the concentration-response curve for the chronotropic effect of histamine in the embryo. The responses to histamine in myocardia from hatched chicks, which were observed in the milimolar range, appeared concurrently with the responses to tyramine during development and were antagonized by beta adrenoceptor antagonists but not by any of the histamine antagonists. The positive inotropic response to histamine in hatched ventricular preparations were greatly attenuated by reserpine pretreatment or in the presence of desipramine. Thus, we demonstrated that exogenously applied histamine produces positive chronotropic and inotropic responses in developing chicken hearts and that the mechanisms are different between embryonic and hatched chicks: direct action on H₂ receptors in the embryonic heart and release of norepinephrine from sympathetic nerve terminals in hatched hearts.     

龙眼参提取物对耐药口腔上皮样癌细胞株KB／MIT及耐药乳腺癌细胞株MCF-7／ADR的逆转作用

目的：研究龙眼参提取物XCKB／MIT细胞及MCF-7／ADR细胞株的耐药逆转作用。方法：设计4个不同浓度的龙眼参提取物组，采用MTT方法．测定体外培养的阿霉素敏感株MCF-7及其耐药株MCF-7／ADR以及米托蒽醌敏感株KB及其耐药株KB／MIT的IC50。结果：MCF-7／ADR耐药株及KB／MIT耐药株在龙眼参提取物与阿霉素或米托蒽醌的联合用药中其IC50值分别接近于单独用约于敏感株MCF-7和KB的水平．而与单独用药于耐药株其IC50有显著性差异。结论：龙眼参提取物可以逆转MCF7／ADR和KB／MIT的耐药性。     

H^＋—ISFET的性能特点及应用研究

本文报道由我们研制的氢离子半导体传感器的性能特点，并与普通离子选择电极（玻璃电极）比较。Ｈ＾＋－ＩＳＦＥＴ具有体积小、取样少、快速、稳定、全固体化、不用预先活化等优点，对氢离子的敏感性也优于普通玻璃电极。本文还成功地将Ｈ＾＋－ＩＳＦＥＴ应用于有复杂成分并存的尿、血及其他生物材料的ｐＨ值测试，并改进胆碱酯酶活力测定方法，将Ｈ＾＋－ＩＳＦＥＴ应用于有机磷中毒后胆碱酯酶活力的快速定量测定。     

人HLA半相合混合脐血在SCID小鼠移植的实验研究

目的：探讨不同供者来源脐血混合移植的可行性和植入特性。方法：分别将两份人HLA半相合混合脐血或单份脐血输入经亚致量照射后的严重联合免疫缺陷（SCID）小鼠，观察两组脐血在SCID小鼠体内的植入状况及多系造血重建特性。结果：混合脐血和单份脐血移植均可在受鼠体内植入，形成供－受混合嵌合体，并能重建多系造血，存活率和植入率无统计学意义（P＞0．05）。用多聚酶链反应－序列特异性寡核苷酸（PCR－SSO）探针检测人HLA－DQB1基因发现，HLA半相合混合脐血移植可有1份或2份脐血植入，其中造血祖细胞含量和体外克隆形成能力高者，更易于植入，造血重建特性与单一脐血移植比较无统计学意义。结论：HLA半相合人混合脐血可同时在SCID小鼠体内植入，形成来自供－受三者的多嵌合状态，并能重建造血及免疫功能。     

Modeling the pharmacokinetics and pharmacodynamics of dexamethasone in depressed patients

Summary Changes in time course effected by cortisol suppression and the relationship of these changes to the plasma dexamethasone concentration of suppressor and non-suppressor patients are described in this report on a combined pharmacokinetic-pharmacodynamic model.Thirteen depressed patients (8 suppressors and 5 non-suppressors) received an intravenous dose (1.5 mg) of dexamethasone. The drug-induced effect changes are found to lag behind, in time, the plasma drug level changes. To accurately relate the temporal relationship of effect changes to plasma dexamethasone levels, a pharmacodynamic model (sigmoid-Emax) was combined with a pharmacokinetic model that incorporated an effect compartment. The magnitude of the time-lag was quantified by the half-time of equilibration between concentrations in the hypothetical effect compartment and the plasma dexamethasone levels (t_&frac;k_eo).The t_&frac;k_eo of the nonsuppressing group was about 50 of that of the suppressing group, indicating that for a given plasma level the onset and termination of effect for the nonsuppressing group is about two times more rapid than for the suppressing group. Moreover, the model can estimate the effect-site concentration that causes one-half of the maximal predicted effect (EC₅₀), a measure of an individual's sensitivity to dexamethasone. The receptor sensitivity (as determined from the EC₅₀ ratio) of the suppressing group was about twice that of the nonsuppressing group.     

FE复合酶防治烧伤后期肉芽创面感染的临床观察

目的观察FE复合酶控制烧伤后期肉芽创面常见耐药菌感染的作用。方法选取笔者单位烧伤患者30例,随机分为治疗组15例,将FE复合酶50 ml溶于等渗盐水0-150 ml中,使其终浓度为1-3 U/ml,用无菌纱布浸湿该液后湿敷创面,1-2次/d;对照组15例,用庆大霉素+ 等渗盐水纱布湿敷创面,1-2次/d。于用药前及用药后1-5 d取创面分泌物作细菌培养,检测两组患者创面的细菌种类及所用药物对创面细菌的敏感率;观察两组患者创面愈合时间及植皮术后3、5、 8、10、12 d的创面愈合率。结果两组患者创面细菌以铜绿假单胞菌、大肠杆菌、阴沟肠杆菌、甲氧西林耐药金黄色葡萄球菌(MRSA)为主。治疗组对MRSA、表皮葡萄球菌、腐生葡萄球菌、铜绿假单胞菌、大肠杆菌、阴沟肠杆菌的敏感率分别为93．8％、100．0％、100．0％、100．0％、100．O％、95．0％,高于对照组的17．6％、31．3％、28．6％、44．0％、33．3％、28.0％(P<0．01)。治疗组植皮术后创面愈合时间为(10．6±1．5)d,明显短于对照组[(15．3±1．7)d,P<0．01]。治疗组患者植皮术后各时相点创面愈合率均明显高于对照组(P<0．01),植皮术后10 d治疗组创面愈合率为(85．4±2．4)％,与对照组(51．3±1．5)％比较,差异有统计学意义(P<0．01)。结论 FE复合酶可以有效控制创面感染,提高烧伤后期感染创面植皮成功率。     

蝎毒多肽对大鼠纤溶系统的作用

从蝎毒中获取具有多种药理活性的肽类混合物（简称ＳＶＰ），用下肢血管灌流和整体给药的动物模型，观察对血管灌流液内纤溶酶原激活物（ＰＡ）活性、血浆优球蛋白纤溶活性（ＥＦＡ）、纤溶酶（ＰＬ）活性的影响。结果：１～２０μｇ／ｍｌ灌流３ｍｉｎ和０．８，１．６ｍｇ·ｋｇ－１ｉｐＳＶＰ１ｈ血浆中ＰＡ活性与对照组相比明显升高（Ｐ＜０．０５或Ｐ＜０．０１），这可能与血管内皮细胞释放ＰＡ活性增加有关。     

革兰氏阴性杆菌发生过程控制的研究

本研究选择奇异变形杆菌和绿肿杆菌等作为实验体系，从群体发生发展过程的宏观表现上探讨了生物控制的时空表达及非线性问题。结果表明，杆菌发生过程的时相周期性可以表现为空间的波形靶图样，并具有分形的特征。实验结果表明，菌群在生长过程中的代谢产物是富含生物信息的控制中介机制。我们认为，生物系统局部存在着准平衡和准封闭的微生态环境，生物液晶的存在和相变是细菌群体发生过程的重要协同中介因素。