正交偏光镜下人体胆汁液晶光学性质的研究

本文报导了在正交偏光镜下，对人体胆汁液晶的光学性质的研究，结果表明，胆汁液晶是一种非均质体，在正交偏光镜下，呈现出特殊的干涉图样和四次消光现象，光性符号是单轴正性的，干涉色级是一级灰白，双折射率Δｎ＝０．０１１－０．０１７。     

Intrauterine light delivery for photodynamic therapy of the human endometrium

Photodynamic therapy is currently being evaluated as a minimallyinvasive procedure for endometrial ablation not requiring anaesthesia.Light penetration depths at 630, 660 and 690 nm and the optimalconfiguration of intrauterine light-diffusing fibres were determinedin 14 human uteri to assist in the design of a light intrauterinedevice. Post-menopausal ex-vivo uteri showed a significantlylower light penetration depth than pre-menopausal uteri. Witha single central diffusing fibre inserted, the fluence ratemeasured in the uterine wall at the most remote point of thecavity decreased to 1.1 ± 0.4% of that measured at closestproximity, whereas it decreased to only 40.0 ± 9.0% withthree fibres. Distension of the uterine cavity with 2 ml ofan optically clear fluid increased the fluence rate at the fundusbetween the fibres at a depth of 2 mm by a factor of 4. We concludethat in normal-sized pre-menopausal uterine cavities, threediffusing fibres will deliver an optical dose above the photodynamicthreshold level at a depth of 4 mm, even in the most remoteareas, in <30 min without causing thermal damage. For distortedand elongated cavities, either slight distension of the cavityor the insertion of a fourth diffusing fibre is required.     

Human myeloma light chains with increased molecular weight: high frequency among lambda chains

The discovery of a human myeloma protein comprising a kappa L-chain with an increased mol. wt of 30,000) (Bouvet et. al., 1980) prompted investigations on the incidence of such heavier L-chains among other human myeloma proteins. In 105 samples examined, 34 were found to have L-chains heavier than normal (23,000-24,000), ranging from 25,000 up to 31,000, and five of lighter mol. wt (21,000-22,000). These mol. wt abnormalities were detected by electrophoresis in sodium dodecyl sulfate 10% polyacrylamide gels (SDS-PAGE) after reduction with 2-mercaptoethanol. The mol. wt of three of the heavier kappa or lambda chains was also estimated by filtration through a Sephadex G100 column and by sedimentation equilibrium. All three methods indicated a mol. wt increase of about 15-25% as compared with the usual mol. wt. The distribution of the high mol. wt chains among all L-chains examined was found to be 11 out of 62 kappa chains (17.7%) and 23 out of 43 lambda chains (53%) (P less than 0.001). A preferential association of such L-chains with H-chains producing multiple bands in SDS-PAGE (P less than 0.01) and an association between multiple L-chain and multiple H-chain band (P less than 0.05) were also observed. In contrast, no abnormal L-chain was found in immunoglobulins from normal subjects. Spontaneous degradation of the normal H-chains sometimes yielded fragments of 30,000 mol. wt. These fragments were easily distinguishable from abnormal L-chains. The nature of extra mol. wt in heavy L-chains was investigated for the presence of carbohydrate moiety. Four large and three normal size L-chains were examined for amino-sugar and sialic acid content. A small amount (one residue per molecule) of amino-sugar was detected only in two normal and two heavy L-chains, whereas sialic acid was only found in the heaviest (27,000-30,000) L-chains (Lh) and in small percentage (one or two residues per molecule). Total sugar estimation in one Lh chain indicated a proportion not exceeding three or four residues per L-chain (mol. wt 1,000) and this is insufficient to explain the 15-25% (3,600-6,000) mol. wt increase. It is therefore possible that, at least in some heavy myeloma L-chains, an additional peptide is expressed. Whatever the nature of the increase it would be of interest to elucidate whether this is a marker of malignant process or of an intermediate step of normal Ig synthesis.     

Clonally restricted insulin autoantibodies in a cohort of 2200 healthy blood donors

Summary Serum samples of 2200 blood donors were screened for anti-insulin IgG by enzyme-linked immunosorbent assay. Specificity of detected antibodies was verified by competition with an excess of insulin and observation that saturated anti-insulin IgG were no longer measurable. The upper limit of measured signal in the population was defined as the mean plus three SD. In the direct assay, 32 sera were positive. Among these, 22 (1%) contained saturable insulin antibodies (true positive) and 10 were non-saturable and considered as non-insulin-specific. The positive blood donors were requested to answer a questionnaire and according to their answers, none had ever received insulin, was a first degree relative of a Type 1 (insulin-dependent) diabetic patient or had experienced a hypoglycaemic episode. None of the 22 true positive sera detected by enzyme-immunosorbent assay bound ¹²⁵-I-insulin to any significant extent. The nine sera yielding the highest signal were further characterized with regard to heavy and light chains as well as species specificity of ligand. Anti-insulin IgG from healthy blood donors contained only one heavy (1 2/9; 3 7/9) and one light ( 8/9; 1/9) chain. Three sera were human insulin specific; two were non-species-specific; the other four bound insulin in the order human = porcine > bovine. These results indicate that low affinity clonally restricted antibodies against insulin are present in unselected blood donors with a prevalence of 1%.     

香青藤的生药鉴定

利用药材性状、显微特征、紫外吸收光谱和薄层层析等鉴别方法对香青藤进行生药鉴定研究 ,为该药材的鉴别和开发利用提供科学依据     

HPLC-ELSD及紫外分光光度法测定三七中皂苷的含量

采用反相高效液相色谱蒸发激光散射检测器测定三七中人参皂苷Rg1的含量。色谱柱为CLC-ODS(6．0mm×150mm),流动相为乙腈-水(3070),蒸发激光散射检测器。定量方法简单,准确。回收率为100．50％,RSD为1．82％。并用紫外分光光度法测定了三七中总皂苷的含量,结果和HPLC法基本一致,说明该方法定量准确,回收率为101．50％,RSD为1．44％。结论认为两方法均可以控制三七的质量。     

红外线短波紫外线照射对感染伤口愈合的影响

目的：探讨红外线、短波紫外线照射对感染性伤口愈合的影响。方法：用随机方法将７２例感染伤口病人分为Ａ、Ｂ两组,每组３６例,Ａ为治疗组：在消炎、伤口换药基础上加用红外线、短波紫外线照射伤口７天,Ｂ为对照组：单纯消炎、伤口换药。结果：Ａ组治愈２８例,显效８例,有效率１００％。Ｂ组治愈１４例,显效１２例,无效１０例,有效率７２％,统计学处理Ｘ＾２＝１５．４７Ｐ〈０．０１,两组有显著差异。结论：红外线、短波     

Signs of the principle body axes prior to primitive streak formation in the rabbit embryo

An early common element during anterior-posterior axis formation amongst amniotes is the primitive streak, running longitudinally in the two-layered embryonic disc. In mammals the primordium of this transient structure is the first definite morphological sign of the anterior-posterior axis, while in avian embryos the axis is visible and apparently defined earlier. Here we scrutinize suggestions that in mammals also there are earlier signs of axis formation by using correlative low and high-resolution light microscopy on tissues from rabbit embryos at 6.3 and 6.5 days post-conception, i.e. immediately before and after primitive streak formation. A series of semithin sections were cut from resin-embedded embryonic discs that had been photographed previously at low power. In embryos at 6.5-days post-conception the primitive streak is as long as up to half the diameter of the embryonic disc, extending anteriorly from a thickening, here called the posterior node, at the posterior margin, which contains the first mesoderm cells ingressing from the epiblast. On both sides of the primitive streak there is a triangular area that appears light in surface views of fixed embryos and correlates with stretches of low-columnar simple epithelium in an otherwise high-columnar pseudostratified epiblast. Within the anterior margin, which has a sharper contour than the rest of the circumference of the embryonic disc, there is a narrow, crescent-shaped dark zone caused by increased cellular height and number in both epiblast and hypoblast. These characteristics of the anterior margin are also found at 6.3 days post-conception, at which stage there is no sign of a primitive streak or a posterior node. The posterior margin, in contrast, is ill-defined in these earlier embryos, or there is a light crescent within the posterior margin, which has the same histological characteristics as the bilateral posterior triangular areas of primitive streak stages. Because the anterior differentiation occurs prior to primitive streak formation and is a sign of both the anterior-posterior and the transverse axes of the embryonic disc, and because some of its histological characteristics are found in primate and human embryos, we propose to name this structure the anterior marginal crescent and to add it to the list of transient structures that gradually establish the principal body axes in mammals. The anterior manifestation of body axes in mammals is thus essentially different from axis development in the avian embryo, where differentiation of these axes is first manifest at the posterior margin.Supported by the Deutsche Forschungsgemeinschaft (Vi 151/1-1); part of the results were presented at the First Joint Meeting of the Anatomical Society of Great Britain and Ireland and of the Anatomische Gesellschaft, Southampton, December 1994, and will be published in abstract form (J Anat, in press)     

Construction,quality assurance and calibration of spherical isotropic fibre optic light diffusers

Spherical isotropic fibre optic light diffusers are used in photodynamic therapy either as a light source or as a light detector. The construction of light diffusers using different materials is described, viz. an optical method involving local polymerization of a dental fissure sealant, which is referred to as the Henderson method, and a second method using plastic or ceramic pre-fabricated spheres. Quality tests necessary for reliable clinical use are presented for the mechanical strength, output power and isotropy. The maximum pull-off force and blow-off output power for the different kinds of diffusers were determined. The calibration procedures are given for measurement of the output power and wavelength of the light emitted by a diffuser and for measurement of the fluence rate by a light-detecting diffuser, using a compact integrating sphere device. With all types of diffusers described, an isotropy can be obtained of better than ± 20% measured over a 320° angle for spheres as small as 1 mm. Larger ceramic diffusers are particularly suitable for delivering high output powers. A 3-mm-diameter ceramic diffuser mounted on a 600-m-core fibre can emit up to 5 W of continuous wave (CW) visible light in air. Diffusers used for light detection can measure the light fluence rate in tissue with 15% accuracy or better if calibration factors are determined for each individual probe.     

A new approach to the study of ocular chromatic aberrations

We measured the ocular wavefront aberration at six different visible wavelengths (between 450 and 650 nm) in three subjects, using a spatially resolved refractometer. In this technique, the angular deviation of light rays entering the pupil at different locations is measured with respect to a target viewed through a centered pupil. Fits of the data at each wavelength to Zernike polynomials were used to estimate the change of defocus with wavelength (longitudinal chromatic aberration, LCA) and the wavelength-dependence of the ocular aberrations. Measured LCA was in good agreement with the literature. In most cases the wavefront aberration increased slightly with wavelength. The angular deviations from the reference stimulus measured using a magenta filter allowed us to estimate the achromatic axis and both optical and perceived transverse chromatic aberration (TCA), (including the effect of aberrations and Stiles-Crawford effect). The amount of TCA varied markedly across subjects, and between eyes of the same subject. Finally, we used the results from these experiments to compute the image quality of the eye in polychromatic light.