THE ACTION OF SODIUM DODECYL SULFATE ON THE CHLOROPHYLL-PROTEIN COMPOUND OF THE SPINACH LEAF

1. Sodium dodecyl sulfate (SDS) attacks the chlorophyll-protein compound modifying its protein properties and absorption spectrum. 2. In the presence of SDS, chlorophyll is quantitatively converted to phaeophytin; i.e., magnesium is removed from the molecule. This reaction, measured spectrophotometrically, proceeds at a rate directly proportional to the hydrogen ion concentration. At constant pH, the rate is proportional to the SDS concentration until a maximum rate is achieved. 3. The chlorophyll or phaeophytin (depending on the pH) remains attached to the protein, since the prosthetic group cannot be separated by ultrafiltration, dialysis, or fractional precipitation. 4. This suggests that the magnesium plays no part in binding chlorophyll to the split protein fragments, but may be concerned in binding the larger units, since the metal becomes extremely labile when the protein is split.     

STUDIES OF THE MICROPROPAGATION OF FOUR ZANTEDESCHIA CULTIVARS

Four Zantedeschia cultivars, namely "Golden Calla", "Pixie", "Pink Persusion" and "Black Magic", were used for this study. By ouly changing the oncentration of zeatin in Murashinge and Skoog mineral medium, good results of micropropaga-tion of Zantedeschia can be achieved even without any other rooting Phytohormone in the medium. The basic steps and the medium are given out as follows: l) shoot multiplication by adding 1 to 3mg/L of zeatin to MS medium; 2) shoot elongation by adding 0.2 to 0.4 mg/L zeatin into MS medium; 3) rooting by adding 0.05 to 0.2mg/L zeatin to MS medium.     

THE MANAGEMENT OF STRABISMUS

The original causes of strabismus and the complications that develop from efforts by a child to adjust to the condition may present a complex diagnostic and therapeutic problem. The complications of suppression, amblyopia, contractures and anomalous visual habits may become more difficult to correct than the cause of the strabismus. The longer the duration of strabismus, the more complex the problem, the more difficult the treatment, and the less the probability of functional cure. Treatment should be started early. Correction may be brought about by the use of glasses, eye patches and orthoptic training, or by operation. If anatomic abnormality prevents bringing the eyes into line by conservative means, operation should be carried out after the best results possible by these means have been achieved. Surgical treatment, too, where it is indicated, should be done early, in order that normal binocular cooperation can develop before abnormal visual habits can become established.     

中期染色体外鞘蛋白质的研究

从12例硬皮病患者的抗染色体抗血清中发现4例是抗中期染色体鞘的,用它们和小鼠腹水癌细胞核及全细胞裂解液SDS-PAGE的蛋白印迹相反应,结果显示它们和细胞核裂解液的11条抗原蛋白相结合,而且和全细胞裂解液中除以上的11条外的另8条相结合。     

SUBCOMMISSURAL IMPLANTATION OF AORTIC PROSTHESES WITH THE USE OF THE NONCORONARY SINUS AND THE FIBROUS TRIGONES

The technique described here permits insertion of a large prosthesis into a small aortic annulus and avoids the necessity of additional procedures for enlarging the aortic ring. Inspection of the fibrous skeleton of the heart reveals that the large intervalvular trigone and the noncoronary sinus of Valsalva are remarkably elastic. Full advantage of this natural elasticity is achieved by suturing the prosthesis to the base of these structures from outside the aorta. Sutures are placed in the sinuses of the right and left cusps in the usual manner. Judicious application of this procedure allows the implantation of a No. 23 or No. 24 prosthesis in cases that would require a No. 19 or No. 21 with the use of conventional methods.     

THE PRIMARY MOULT OF WADERS ON THE ATLANTIC COAST OF MOROCCO

Data from 3659 waders of 23 species live-trapped in the years 1971-73 on the Atlantic coast of Morocco during the period of autumn moult and migration are analysed to estimate duration and timing of primary moult. Common Sandpiper was the only species to moult primaries in its first autumn (unless published ageing criteria are incorrect). Several species showed a low incidence of arrested primary moult and a higher incidence was observed in Ringed, Kentish and Grey Plovers. This is discussed in relation to breeding and migration. Similar rates of primary feather replacement relative to specific moult duration were observed in all species for which information was available. Comparisons between species and with published studies showed that variations in rate of moulting between species and between different geographical populations of the same species were largely due to differences in feather growth rate rather than in the numbers of primaries concurrently in growth. Variations in rate between individuals of the same population were achieved, at least in the first part of moult, by differences in feather dropping rate resulting in differences in the numbers of primaries growing concurrently. The timing and duration of moult in different populations and differences between breeding and non-breeding components were closely related to the requirements of other annual cycle activities, notably breeding and migration. Non-breeding birds summering in Morocco had started moult early. Locally breeding birds had an early start to a fairly slow moult which overlapped with breeding and which in some cases passed through an arrested stage. Birds breeding in cold temperate and arctic regions and wintering in Morocco moulted in a short time soon after arrival. In some cases, notably in Ringed Plovers, birds had commenced moulting on the breeding grounds and arrested moult during migration. Most Redshank and possibly Dunlin migrated in active wing moult. The fastest primary moult was achieved by high arctic breeding birds, Curlew Sandpiper and possibly Little Stint, which stopped to moult in Morocco before moving on to wintering areas further south. This situation is contrasted with that of populations of these two and other species wintering in the southern hemisphere where moult occurs over an extended period during the northern winter.     

THE USE OF SOLUBILITY AS A CRITERION OF PURITY OF PROTEINS : I. APPLICATION OF THE PHASE RULE TO THE SOLUBILITY OF PROTEINS. II. THE SOLUBILITY CURVES AND PURITY OF CHYMOTRYPSINOGEN

1. The conditions under which the phase rule may be applied to systems containing proteins are formulated. 2. An attempt was made to fractionate chymotrypsinogen, by crystallization in stages with increasing concentration of magnesium sulfate. No significant fractionation of the protein was achieved, but a small amount of impurity which affects the solubility, while having little influence on other properties of the material, was concentrated in the fractions first precipitated. 3. The solubility of the final fraction was independent of the amount of the saturating solid, from the first appearance of a solid phase, in solvents of three different pH''s. The solubility was independent of the environment in which the crystals were formed (within the limits in which crystallization can be carried out) and the same value was reached from the supersaturated as from the undersaturated side. This material, therefore, conforms closely with the phase rule criteria of a pure protein.     

THE DIFFERENTIATION OF BACTERIAL SPECIES BY PAPER CHROMATOGRAPHY. II. LACTOBACILLI AND STREPTOCOCCI; THE EFFECT OF AGE OF CULTURE

SUMMARY: The pictures obtained when extracts of intact bacterial cells are subjected to paper chromatography show some small variations according to the age of the culture. Larger variations occur if a culture is very old. Satisfactory consistency and differentiation of species can be achieved by harvesting cells when, or soon after, the rate of increase of optical density in the cultures begins to decline.     

中国姬鼠属的系统学研究述评

姬鼠属分布在欧亚大陆及其邻近的岛屿上, 种类及数量均较多。但对该属的分类和系统发育关系一直存在争议, 尤其近几年对姬鼠属分子系统学的研究, 产生了一些与形态学、生物地理学等研究不同的结果。文章综述了姬鼠属系统学研究的一些工作, 根据所归纳的初步论点, 试拟定了中国现生种类的系谱; 并对中国姬鼠属系统学的进一步研究, 提出了一些建议。     

DYNAMIC CHANGES IN THE ULTRASTRUCTURE OF THE ACINAR CELL OF THE RAT PAROTID GLAND DURING THE SECRETORY CYCLE

Synchronization of the secretory cycle in vivo was obtained by injecting isoprenaline as an inducer of secretion. A quantitative correlation between enzyme release, its subsequent reaccumulation, and the sequence of ultrastructural changes was found. At the ultrastructural level secretion was paralleled by depletion of zymogen granules through fusion of the granule membrane with the lumen membrane and discharge of the content. Each zymogen granule membrane, once connected with the lumen, acted as a lumen membrane. Fusion was thus sequential and resulted in a dramatic enlargement of the lumen space. During the entire process the passage between the lumen and the intercellular space remained blocked by the tight junctions, as shown by their impenetrability to ferritin. Reduction of the lumen size following enzyme discharge seemed to be achieved by withdrawal of lumen membrane in the form of small smooth vesicles which appeared mostly in the apical part of the cell. At the same time, the cell retracted towards the lumen, the whole process being completed within 2 hr from onset of secretion. Disappearance of the smooth vesicle followed, concomitant with formation of many condensing vacuoles and appearance of mature zymogen granules. The fate of the zymogen granule membrane, including its fusion with the lumen membrane, resorption in the form of small smooth vesicles, and its eventual reutilization mediated by the Golgi system, is discussed.     

STEREOSELECTIVE SYNTHESIS OF 3-HYDROXYMETHYL-D-CYCLOPENTENONE,THE VERSATILE INTERMEDIATE FOR THE SYNTHESIS OF CARBOCYCLIC NUCLEOSIDES

The preparative and stereoselective synthesis (45–50% overall yields, >50 g scale) of the key carbasugars 7a–d was achieved from D-ribose via stereoselective Grignard reaction and oxidative rearrangement as key reactions.     

成人肾恶性横纹肌样瘤的研究:1例报告及文献复习

应用组织化学、免疫组织化学及电镜技术对我国首例成人肾恶性横纹肌样瘤（ｍ ａｌｉｎｇａｎｔｒｈａｂｄｏｉｄｔｕｍ ｏｒ, ＭＲＴ） 进行了研究, 与婴幼儿ＭＲＴ相比本例有以下临床病理特点： （１） 以血尿为早期和唯一症状,肿块缺乏特征性ＣＴ 改变; （２） 光镜下大量ＰＡＳ阳性嗜酸性球形小体多位于细胞外, 电镜下细胞外小体由微丝构成并有界膜包绕; （３） 免疫组化显示肿瘤细胞向神经外胚层、横纹肌和组织细胞多向性分化; （４） 肿瘤侵袭力较低, 高度表达ｎｍ ２３－Ｈ１ 蛋白, 随访１８个月术后化疗效果佳, 提示其恶性度较婴幼儿ＭＲＴ 低。     

THE USE OF SMALL FARM DAMS IN THE TRANSKEI AND CISKEI FOR THE PRODUCTION OF TABLE-FISH USING AISCHGRUND CARP

SUMMARY

Small stockwatering dams are usually ignored in the Transkei and Ciskei in fishfarming ventures. This paper reports on experimental results in fish production studies, using Aischgrund carp, which were obtained in the Ciskei and which indicate that economically worthwhile fish production can be achieved in such dams.     

A METHOD FOR THE CULTIVATION OF ANAEROBIC SPORE FORMING BACTERIA

SUMMARY: A method is described for the cultivation of anaerobes based upon the following two principles: (1) Anaerobiosis is achieved by the addition of an aerobic micrococcus to the nutrient medium itself. After anaerobiosis has been achieved the micrococcus gradually dies, leaving the anaerobes in a pure state. (2) In the plate technique it is necessary to prevent diffusion of oxygen from the air into the medium. This is effected by covering the agar with a film of Saran which is impervious to oxygen. The plate method is carried out in ordinary Petri dishes: anaerobic jars are not used.     

千层塔植物茎叶中黄酮类物质的研究

本实验利用分光光度法对千层塔植物茎叶内的黄酮类物质进行了初步测定 ,确定了总黄酮含量提取的适宜溶剂浓度和提取的适宜时间。结果表明 ,用 6 0 %的甲醇溶剂提取 6h总黄酮含量最高。此外 ,本试验还对千层塔黄酮提取液进行了各种定性颜色反应 ,初步确定其中的黄酮类物质主要为黄酮类和黄酮醇类。     

THE CELL CYCLE IN TUMOURS: AN EXAMINATION OF DATA GAINED BY THE TECHNIQUE OF LABELLED MITOSES

Published data from a large series of investigations by the technique of labelled mitoses have been analysed using a process of computer simulation. The results of the analyses of tumour data are discussed, first from the point of view of the quality of simulation that can be achieved and secondly as a review of the extent of our knowledge of the intermitotic time of cells in tumours. Particularly in primary tumors the data are often consistent with a broad distribution of intermitotic times within a tumour and the use of the term 'cell cycle time'may be misleading.     

KINETICS OF NEUTROPHILIC GRANULOCYTES IN THE BLOOD OF RATS

The kinetics of neutrophilic granulocytes in the blood of rats were investigated using in vivo ³H-TdR labelling and autoradiography. The radioactive precursor was administered by single injection, repeated injections at 5 hr intervals and continuous infusion. The appearance of labelled granulocytes in the blood and in the sputum was recorded up to 120 hr after tracer application. In contrast to results after a single injection of ³H-TdR, complete labelling of the blood granulocyte pool was achieved when the DNA precursor was given by continuous infusion or four repeated injections at 5 hr intervals. In the latter experiments, an exponential replacement of unlabelled blood granulocytes by labelled granulocytes could be demonstrated, the mean intravascular half-life being 5·7 hr. This figure is in good agreement with values obtained by isotopic techniques in other mammalian species.     

THE EFFECTS OF AMINO ACIDS UPON THE DEVELOPMENT OF EXCISED FLORAL BUDS OF AQUILEGIA

Young excised floral buds of Aquilegia were grown on a chemically defined medium containing various concentrations of single amino acids or mixtures of amino acids. γ-Amino butyric acid significantly promoted floral development through the initiation and differentiation of carpels. These floral organs were generally absent on the basal medium. Alanine, glutamic acid, and aspartic acid had no effect upon floral development. All other amino acids were either ineffective at lower concentrations and inhibitory at higher concentrations or were inhibitory at all concentrations. Casein hydrolysate and a mixture of amino acids found in coconut milk were ineffective. The addition of both γ-amino butyric acid and alanine to the basal medium promoted development approaching that achieved on the coconut-milk medium. However, further growth factors appear to be required before development on coconut-milk medium is equalled or exceeded.     

INITIATION OF THE VASCULAR SYSTEM IN THE FERTILE FLORET OF ANTHOXANTHUM ODORATUM (GRAMINEAE)

Procambium was initially isolated near the insertions of lemma and stamen primordia in the grass Anthoxanthum. The palea was initiated before its procambium. The acropetal, continuous differentiation of procambium involved in the siting of leaves on shoots of many other megaphyllous plants, does not occur in the rachilla of this grass. A portion of the vascular system of the fertile floret of Anthoxanthum became connected with the vascular system of the rest of the spikelet by basipetal differentiation of the procambial trace of the fertile lemma. A core of residual meristem persisted in the fertile floret above the procambial trace to the fertile lemma. Vascular continuity between the procambial trace to the fertile lemma and the procambial traces of the stamens was achieved by the differentiation of procambium from this core of residual meristem.     

ELECTRON MICROSCOPE STUDIES OF THE MICROVILLI OF HELA CELLS

Microvilli of HeLa cells cultured in vitro were preserved for electron microscopic examination at different stages of routine cultivation procedures. By a double-embedding technique, vertical sectioning for electron microscopy was possible. It revealed that, although the microvilli were present on all sides of the cell in the dispersed stage and in the attached stage, they were not present on the bottom of the cell when it was stretched on the surface of the dish. When the cells were grown in dense colonies, they were found on top of each other, and microvilli were present on all sides, except on the bottom surface of those cells in contact with the dish. We achieved a more dramatic demonstration of the microvilli by developing a surface-replica technique which retains their spatial arrangement and permits characterization of the distribution of their number, length, and diameter.