氨乙基氨丙基聚二甲基硅氧烷改性水性聚酯型聚氨酯的研究

由聚酯二元醇、异佛尔酮二异氰酸酯和二羟甲基丙酸合成聚氨酯预聚体，以氨乙基氨丙基聚二甲基硅氧(AEAPS)为扩链剂，制备了AEAPS改性聚氨酯水分散液。与未改性的聚氨酯水分散液相比，AEAPS改性聚氨酯水分散液的粒径增大，但粒径分布和表面张力基本不变，说明疏水的聚二甲基硅氧烷侧链被包裹于分散颗粒的内部；此外，改性聚氨酯水分散液的冻融稳定性显著增强。AEAPS改性聚氨酯水分散液成膜后，吸水率明显下降，水在膜表面的接触角增加，400℃时热失重下降，具有良好的疏水性和耐热性。     

国人跟骨距关节面的形态研究

观察329块(男193,女136)国人成年跟骨的距关节面形态。其中A型出现率,男为45.08±3.58％,女为41.18±4.22％;B型出现率男为53.89±3.59％,女为58.82±4.22％;C型仅男性出现2例,占1.04±0.73％。成套标本中,距关节面左右对称的,男性90例中有81例,占90.00±3.16％;女性67例中有59例,占88.06±3.96％。经统计学处理,侧别间及性别间均无明显差异。文内结合观察结果提出自己的分型标准及类型,并与以往资料进行了比较。     

Topical application of fluorides on teeth

Abstract Prevention of caries in exposed root surfaces constitutes an important clinical problem. It is thus important that clinicians involved with periodontology have an insight into fluoride prophylaxis. The understanding of the cariostatic mechanism of fluoride has improved during recent years. The aim of the present review is to give a short account of the present concept. Calcium fluoride appears to be the only product which is formed on enamel, dentin or cementum during brief topical treatments with fluoride or use of toothpaste containing fluoride. This calcium fluoride is stable in the oral environment: this is contrary to what was believed until recently. The calcium fluoride constitutes a pH-dependant reservoir of fluoride which releases fluoride when pH drops. The practical consequences of this concept is discussed.     

Reversible Adsorption of Soluble Hexameric Insulin onto the Surface of Insulin Crystals Cocrystallized with Protamine: An Electrostatic Interaction

Mixing pharmaceutical preparations of soluble neutral regular insulin solution (NRI) and neutral protamine Hagedorn (NPH) crystalline insulin suspension leads to a reduction in the measurable amount of soluble insulin in the formulation supernatant. However in spite of the loss in soluble insulin, the time-actions of these components have been shown, in clinical trials, to be unaffected. The interaction between these different physical forms of insulin has been studied using reversed-phase HPLC, isothermal titrating calorimetry, and Doppler electrophoretic light scattering analysis. Sorbent surface and solution perturbation studies revealed that the NRI adsorbs to the surface of the NPH crystal with an equilibrium constant ranging from 10⁴ M^–1 to 10⁷ M^–!, depending on the protamine concentration, pH, ionic strength, and temperature. This adsorption behavior suggests that the binding is mediated by electrostatic interactions arising between the positively-charged NPH crystal and the negatively-charged NRI hexamer. Doppler electrophoretic light scattering results, used to probe the pH-dependent surface charge of NPH and soluble insulin hexamer, support the conclusion that electrostatic interactions mediate the adsorption process. Adsorption studies under physiological conditions indicate that the elevated temperature and ionic strength, in a subcutaneous depot, are sufficient to lead to the dissociation of the NRI/NPH complex that exists in these NPH mixture formulations.     

单克隆抗体对溶组织内阿米巴吞噬红细胞的影响

用具有抗细胞膜活性和抗细胞核、胞浆活性的单克隆抗体３Ｆ７和４Ｇ６与致病性溶组织内阿米巴ＨＭ－１∶ＩＭＳＳ株滋养体３７℃孵育，在孵育即刻、５ｍｉｎ、１０ｍｉｎ加入红细胞，检测滋养体吞噬红细胞的能力，并以正常小鼠血清和抗克氏锥虫抗体ＴＣＥ０４作为对照。结果，经单克隆抗体３Ｆ７孵育即刻的ＨＭ－１∶ＩＭＳＳ虫株滋养体吞噬红细胞能力明显减弱（Ｐ＜０．００１），而４Ｇ６抑制滋养体吞噬红细胞的作用不如前者明显。提示，抗细胞膜单克隆抗体对抑制滋养体吞噬红细胞有显著作用，但随着时间的推移，抑制作用明显减弱。     

Active surfactant in pharyngeal aspirates of term neonates: lipid biochemistry and surface tension function

Alveolar surfactant is well known for its ability to reduce minimal surface tension at the alveolar air–liquid interface to values below 5 mN m^?1. In addition, it has been suggested that surfactant is also present in the airways, particularly in the perinatal period. We isolated surfactant from pharyngeal aspirates obtained from 33 neonates immediately after delivery and analysed it for both phospholipid (PL) composition and surface tension function. PL classes and phosphatidylcholine (PC) molecular species were determined by normal and reversed-phase high-performance liquid chromatography (HPLC), respectively. Static and dynamic surface properties of the surfactant were studied in a pulsating bubble surfactometer. Sample volume was 1.3 ± 0.5 mL (mean ± SD) with a total amount of 2.5 ± 1.3 μmol of PL and a concentration of 2.1 ± 1.0 μmol mL^?1 PL. HPLC analyses of PL classes revealed a composition identical with surfactant prepared from alveolar washes, i.e. PC 83.6 ± 2.1%, sphingomyelin 1.4 ± 0.5%, phosphatidylglycerol 8.1 ± 1.6%, phosphatidylethanolamine 2.1 ± 0.5% and phosphatidylinositol 2.6 ± 1.1%. Thin-layer chromatography showed almost identical results but was more time-consuming and needed more material for analysis. Analysis of PC molecular species revealed a composition typical of human alveolar surfactant with 54.7 ± 3.9% dipalmitoyl PC, 10.3 ± 1.9% palmitoyloleoyl PC and 9.1 ± 1.5% palmitoylmyristoyl PC. Minimal surface tension fell to values below 5 mN m^?1 within 5 min of cycling in all subjects. The methods used in this study allowed for complete PL and surface tension analyses of surfactant obtained during routine pharyngeal suctioning after delivery at term. Whether they are also applicable to preterm neonates with respiratory distress remains to be determined.     

Motor unit potential contribution to surface electromyography

The background of the bioelectric activity of muscle recorded from the surface of the skin (surface electromyography) in terms of the representation of single motor units of the underlying muscle(s) is not very well documented or understood. An insight into the composition of an electromyogram is essential for the proper interpretation of one of the most widely applied electrophysiological techniques. In the present paper, a study of the contribution of single motor unit potentials to the surface electromyogram is presented. To this end, the decline of different components of the motor unit potential with depth of the motor unit is quantified. Experimentally, the action potentials from motor units at several positions in the muscle were recorded by 30 skin surface electrodes. Simultaneous use of scanning electromyography provided information about the actual position and size of the motor unit. Observed linear log–log relationships between motor unit potential magnitudes and distance indicated the usefulness of a power function to describe the motor unit potential's dependence on recording distance. It is shown that different specific surface motor unit potential characteristics fall off differently with depth. The magnitude–distance relationship is shown to be dependent on the recording configuration (unipolar vs. bipolar recording, including the inter-electrode distance) and the chosen motor unit potential parameter (negative peak amplitude, positive peak amplitude and area).     

A stereological study of the human ovarian surface epithelium.

The surface of the ovary has been found to be composed of two types of epithelial cells called A and B cells which are found in their own respective zones, the A and B zones. A quantitative study was undertaken to determine the mean cell volumes and cell ultrastructure. Ovarian biopsies were taken from six women and A and B zones, having been identified by scanning electron microscopy, were re-embedded for transmission electron microscopy. Stereological measurements using point sampled intercepts were made on vertical sections and showed that B cells are significantly larger than A cells. The volume weighted mean cell volumes of the A and B cells were 237.3 microns 3 and 676.8 microns 3 respectively. The volume fractions of the nucleus and mitochondria were similar in the two cell types. Although the vesicle content of each type was similar, a large variation between cases made the interpretation difficult. The stereological tools used in this study proved to be easy and efficient estimators of surface cell ultrastructure and give an important direction for ultrastructural research.     

H—TdR前体掺入技术在复方中药抗癌制剂研究中的应用

将一种快速、灵敏、可靠、简便的抗癌活性微量测定技术——~3H—TdR前体掺入技术用于复方中药抗癌制剂制备工艺筛选,短期内即拟定出较合理的工艺,经临床及14项生物学指标综合评定,该制剂疗效好,无明显的毒副作用。表明把一些快速、灵敏的医学检测技术引入药物制备工艺、质量标准及稳定性研究,可克服由于活性成分不清楚带来的一些困难,拓宽了研究途径,提高了研究水平。