VENUS'S FLYTRAP OBSERVATIONS BY SCANNING ELECTRON MICROSCOPY

Observations of the digestive glands, trigger hairs, epidermal surface, nectar glands, touch receptors, and stomata of Dionaea muscipula, the Venus's flytrap, were carried out by means of scanning electron microscopy. Previously undescribed details of the surface topography were resolved which may correlate with certain functions of the plant.     

THE UPTAKE OF PURINES BY RAT BRAIN IN VIVO AND IN VITRO

Abstract— The uptake of [¹⁴C]guanine and some of its [¹⁴C]-labelled derivatives into rat brain was studied in vivo and in vitro. In vivo guanine, guanosine, and hypoxanthine penetrated the brain of adult rats to a very small extent. Inosine was taken up somewhat better. In young animals, also, guanosine was taken up poorly, but guanine was taken up fairly well. When guanine was administered to adult animals, only guanine was found in the brain. In young animals, by contrast, radioactivity from guanine appeared in guanosine and in guanine nucleotides, but no free guanine was found. In vitro guanine was taken up much better and, in fact, remained mostly as guanine in slices from 10-day-old rats. The in vitro conversion of guanine to GMP and its incorporation into RNA was unimpaired by the addition of unlabelled guanosine, an indication that guanine was converted directly to GMP. The uptake of guanine in vitro was not subject to competitive inhibition or influenced by the presence of dinitrophenol. This finding suggested that guanine entered the slice by simple diffusion.     

食蟹猴疟原虫晚期卵囊、成孢子细胞与子孢子扫描电镜观察

本研究对实验感染食蟹猴疟原虫后9、10和14天的斯氏按蚊阳性蚊胃,进行扫描电镜观察。晚期(分化的)卵囊表面呈现凹凸不平皱褶。成孢子细胞体常呈圆球形或椭圆形,表面光滑,子孢子芽从其表面长出。子孢子体细长,稍弯曲,体表光滑;虫体前部较细,顶端稍平,后部稍粗,末端钝圆。本文对成孢子细胞不同发育阶段的形态予以较详细描述,对子孢子出囊方式做了初步讨论。     

革胡子鲶受精过程的扫描电镜观察

应用扫描电镜观察和描述了革胡子鲶成熟卵和精子的形态、卵壳膜的表面结构和形态、受精孔的位置和结构、精子入卵过程的程序和变化。讨论了精子入卵过程及精孔细胞在解体之后可能转变为一种能够吸引精子在精孔区聚集的“受精素”物质等问题。     

RATE OF STEROL FORMATION BY RAT BRAIN GLIA AND NEURONS IN VITRO AND IN VIVO

The ability of 11-day-old rat glial and neuronal cells to biosynthesize sterol was studied as a function of time in vivo and in vitro. The in vitro experiments utilized [2-¹⁴C]mevalonic acid as precursor. Glial-enriched cell preparations demonstrated a greater ability to incorporate [2-¹⁴C]mevalonic acid into isoprenoid material than did neuronal-enriched preparations. Approximately 4 h were required for maximal uptake of labelled mevalonate by the glial preparations. Further metabolism of the isoprenoid material, involving squalene turnover and sterol demethylation, was still evident even after 15 h of incubation. In vivo, sterol biosynthesis was studied by intraperitoneal injection of sodium [2-¹⁴C]acetate and [U-¹⁴C]glucose, sacrifice of the animals at 2 or 24 h, subsequent isolation of glial- and neuronal-cell enriched fractions and analysis of labelled isoprenoid material. Glial-enriched fractions again contained the bulk of the labelled isoprenoid material.     

猪淋巴细胞表面E受体再生表达的免疫电镜观察

本文用酶标免疫电镜技术对猪外周淋巴细胞E受体在细胞表面的分布以及在细胞内合成代谢的状况进行了研究。实验结果表明:E受体在淋巴细胞表面呈点状均匀分布。胰蛋白酶处理使细胞表面E受体消失,经培养后可逐渐自发重建;正常情况下静止的淋巴细胞内E受体的合成水平很低;小牛胸腺肽制剂处理可以促进E受体在细胞质内的合成,加速其表达过程;更生霉素及嘌呤霉素等RNA合成抑制剂可抑制E受体的再生;以ConA活化的猪淋巴细胞内可见E受体活跃的合成;E受体合成部位是在粗面内质网上及散在的核蛋白体上。     

ELECTRON MICROSCOPE OBSERVATIONS ON THE FUSION OF CHICK MYOBLASTS IN VITRO

The process of myoblast fusion was observed in embryonic chick skeletal muscle cells grown in monolayer cultures at the fine structural level. At the first step, the sarcolemmas of cells destined to fuse are closely applied to each other. They are linked in some places by fasciae adherentes; in other places, engulfment of small processes of one cell by another is seen. At a somewhat more advanced stage of myogenesis, vesicles and tubules are formed between the adjacent cytoplasms; presumably, the apposed membranes have opened at several points and their edges have fused to each other. Finally, remnants of cell membranes (vesicles and tubules) disappear completely, and the confluent cytoplasm is formed. The cytoplasmic contents of the multinucleated cells are often poorly admixed, giving the cytoplasm a mosaic appearance in which different zones can be designated as arising from separate cells. This observation suggests, however, that there is slow diffusion of myoblast contents (ribosomes and, possibly, other materials) into the myotube. In agreement with the previous works at the light microscopic level, the present study suggests the occurence of fusion between mononucleated cells, between mononucleated cells and multinucleated myotubes, and between nascent multinucleated myotubes.     

中华绒螯蟹血细胞的显微、亚显微形态结构及其分类

通过相差显微镜和电镜观察,根据中华绒螯蟹血细胞胞质内有无颗粒以及颗粒大小、染色反应、折光性和形成方式的特点,血细胞分为胞质内无颗粒的无颗粒细胞、胞质内只有具折光性和呈淡红色反应大颗粒的大颗粒细胞、胞质内只有无折光性和呈淡蓝色染色反应小颗粒的小颗粒细胞以及胞质内同时具有大颗粒和小颗粒二种颗粒特性的大小颗粒中间型细胞.小颗粒的形成方式是高尔基体成熟面小泡脱离后直接成为小颗粒,而大颗粒的形成方式是高尔基体成熟面小泡脱离后,数个小泡逐渐聚集成蜂窝状大颗粒,进一步发育成熟为均质大颗粒.实验结果表明:三种有颗粒的细胞是互相独立的,可能分别由无颗粒细胞分化而成.       

LOCALIZATION OF ANTIBODIES BY ELECTRON MICROSCOPY IN DEVELOPING ANTIBODY-PRODUCING CELLS

The development of antibody-producing cells in the early stages of the secondary or hyperimmune response has been studied with the electron microscope in lymph nodes of adult chinchilla rabbits immunized with ferritin or apoferritin. The intracellular distribution of antiferritin antibodies was determined in the lymph node cells at 1 to 5 days after a booster injection, employing the labelling technique previously used by the authors (12) to demonstrate the localization of antibodies in mature plasma cells. Antibodies were first detected at 48 hours in blasts; i.e., cells which have a poorly developed endoplasmic reticulum and a cytoplasm filled with many ribosomes grouped in clusters. The label was subsequently found in forms intermediate between blasts and plasma cells (plasmoblasts, immature plasma cells), in which the endoplasmic reticulum appeared progressively more developed. Antiferritin antibodies were also found in cells in mitosis. In all the above cell types, antigen-antibody precipitates were consistently found in the perinuclear space and in the cisternae of the granular endoplasmic reticulum, from an early stage in the development of the latter. Evidence was also obtained for the presence of antibody in the Golgi area. The results are discussed in relation to the possible cellular sites of antibody synthesis.     

脑肿瘤时致癫痫病变的免疫组织化学和电镜观察的研究

11例肿瘤致癫痫病患者在脑皮质电图和深部电极描记监测致癫痫灶下,行肿瘤和致痫灶的切除。用免疫组织化学方法检测肿瘤和致痫灶内的细胞浆内胶质原纤维酸性蛋白、神经细丝、纤维联结蛋白和内皮细胞及电镜观察。发现致痫灶分别在肿瘤灶(5例)和肿瘤的周边区(6例)内,每一致痫灶内见残留神经元或变性的轴索由瘤性或增生的星形细胞的胶质原纤维或增生血管周细胞的胶原原纤维围绕或包绕;致痫灶内神经元固缩或空泡变性,线粒体肿胀、粗面内浆网扩张,轴索变性及髓鞘板层分离。结合上述所见,讨论了星形细胞在癫痫发作中的机理。     

COMPARATIVE MORPHOLOGY OF RADULAR TEETH IN CONUS: OBSERVATIONS WITH SCANNING ELECTRON MICROSCOPY

Radular teeth of 22 Indo-Pacific species of the genus Conus(Neogastropoda: Toxoglossa) were compared. On morphologicalfeatures all can be related to one of three known feeding modes:piscivorous, vermivorous and molluscivorous. Observations arereported on the radular teeth of six piscivores, thirteen vermivoresand three molluscivores. The radular teeth of piscivores areof two general types. In the first, two barbs and a posteriorly-directedprocess with a recurved tip are found at the anterior end. Inthe second, two barbs are located at the anterior end and theshaft is serrated for most of its length. An enlarged posteriorregion (terminal knob) is present in the first and absent inthe second. Molluscivores possess radular teeth with two anteriorbarbs and in some species a serrated shaft or terminal knob.The radular teeth of vermivores, which show much greater interspecificvariation than those of piscivores or molluscivores, are characterizedby one or two anterior barbs and in most species a serratedregion near the apex. A forwardly-projecting cone (basal spur)is usually located on the terminal knob. Piscivores and molluscivoreslack such basal spurs. The radular teeth of Conus are used toconvey a potent venom and hold prey firmly during feeding. Previouslyundescribed morphological features are noted on the teeth ofC. obscurus and C. lividus. Figured here for the first timeare the radular teeth of C. abbreviatus, C. aureus, C. catus,C. litoglyphus, C. pennaceus, C. rattus and C. sponsalis. ^*Present address: Department of Paleontology, University ofCalifornia, Berkeley, California 94720, U.S.A. (Received 2 April 1979;     

VITRIFICATION OF IN VIVO AND IN VITRO PRODUCED OVINE BLASTOCYSTS

Although cryopreservation of bovine embryo has made great progress in recent years, little achievement was obtained in ovine embryo freezing, especially in vitro produced embryos. However, a simple and efficient method for cryopreservation of sheep embryos will be important for application of ovine embryonic techniques such as in vitro fertilization, transgenic, cloning and etc. In this study ovine blastocysts, produced in vivo or in vitro, were cryopreserved by vitrification in EFS40 (40% ethylene glycol (EG), 18% ficoll and 0.5 M sucrose) or GFS40 (40% glycerol (GL), 18% ficoll and 0.5 Mol sucrose). In Vitro produced, early blastocysts were directly plunged into liquid nitrogen (LN₂) after preparation by one of the following procedures at 25°C: (A) equilibration in EFS40 for 1 min; (B) equilibration in EFS40 for 2 min; (C) equilibration in EFS40 for 30 s following pretreatment in 10% EG for 5 min; (D) equilibration in EFS40 for 30s following pretreatment in EFS20 for 2 min (E) equilibration in GFS30 for 30 s following pretreatment in 10% GL for 5 min. The survival rates observed after thawing and in vitro culture for 12 h were A 78.0% (39/50), B 50.0% (26/52), C 93.3% (70/75), D 92.0% (46/50) and E 68.0% (34/50). Survival rates were not significantly different for treatments C and D (p>0.05), but those for groups C and D were significantly higher than for A, B and E (p<0.05). After 24 h in vitro culture, hatched blastocyst rates were A 28.0% (14/50), B 21.1% (11/52), C 49.3% (37/75), D 48.0% (24/50), E 32.0% (16/50) and control 54.0% (27/50). The hatching rates for groups A, B and E were significantly lower than the control (p<0.05) in which early IVF blastocysts were cultured in fresh SOFaaBSA medium following treatment in PBS containing 0.3% BSA for 30 min, but for groups C and D it was similar to the control (p>0.05). The freezing procedures A, B and C were used to vitrify in vivo produced, early blastocysts recovered from superovulated ewes. The survival rates of frozen-thawed in vivo embryos were A 94.7% (72/76), B 75.0% (45/60) and C 96.4% (54/56) and for group B was significantly lower than for the other two treatment groups (p<0.05). Hatched blastocyst rates were A 46.0% (35/76), B 26.6% (16/60), C 51.8% (29/56) and the control 56.7% (34/60) in which early blastocysts from superovulation were cultured in fresh SOFaaBSA medium following treatment in PBS containing 0.3% BSA for 30 min. The hatching rate for treatment B was significantly lower than for the control (p<0.05) but did not differ between groups A, C and the control (p>0.05). Frozen-thawed embryos vitrified by procedure C were transferred into synchronous recipient ewes. Pregnancy and lambing rates were similar for embryos transferred fresh or frozen/thawed for both in vivo and in vitro produced embryos. These rates did not differ between in vivo and in vitro embryos transferred fresh (p>0.05). However, for frozen-thawed embryos, both rates were significantly lower for in vitro than for in vivo produced embryos (p<0.05).     

ELECTRON MICROSCOPY OF PHIALIDES AND CONIDIOGENESIS IN TRICHODERMA SATURNISPORUM

Each phialide had a thick-walled neck region located immediately below a light microscopically inconspicuous collarette. The thickened wall of the phialide neck was multilaminate, with layers of different electron transmission properties. A developmental stage in the formation of the first conidial initial was observed. Conidial initials blew out through the thickened neck region, increased in size, and were eventually delimited by centripetally developing septa. Mature, winged conidia had an electron-opaque outer wall layer and an electron-transparent inner wall layer. The wing was formed by separation of these outer and inner wall layers and buckling or wrinkling of the outer layer. As early as they could be discerned, conidial initials had developed the electron-opaque wall layer which characterized mature conidia. Each conidium-delimiting septum became bilayered; the upper layer formed part of the conidial base, and the lower layer became a portion of the wall of the next conidial initial. Phialides lacked an electron-opaque wall layer, and they possessed areas of abundant rough endoplasmic reticulum, as well as free ribosomes. Lipid globules were also abundant, especially in conidia. The distinction between phialides and annellides was questioned.     

ELECTRON MICROSCOPIC OBSERVATIONS OF GUINEA PIG SPERMATOZOA PENETRATING EGGS IN VITRO*

Guinea pig ovarian oocytes matured in vitro were inseminated in vitro with capacitated, acrosome-reacted spermatozoa and sperm penetration through the zona pellucida and into the egg cytoplasm were examined. Sperm heads passing through the zona pellucida had already lost all their acrosomal elements except for the inner acrosomal membrane and the equatorial segment. It was often observed that the texture of the zona material around the sperm head was distorted, giving the impression that the zona pellucida was parted, at least partially, by a shearing force produced by the sperm head advancing through the zona. When eggs were freed from their zonae pellucidae and inseminated, the acrosome-reacted spermatozoa immediately bound to the egg surfaces and began to fuse with the eggs; whereas the spermatozoa with intact acrosomes failed to do so. Fusion began between the egg plasma membrane and the sperm plasma membrane at the central region of the sperm head. The anterior half of the sperm head was engulfed by the egg in a phagocytic fashion, while its posterior half was incorporated into the egg by a fussion between egg and sperm plasma membranes. Incorporation of the sperm tail into the egg was achieved by fusion between the sperm and egg plasma membranes.     

SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO. II

1. The pH-activity relationship of invertase has been studied in vivo and in vitro under identical external environmental conditions. 2. The effect of changing (H⁺) upon the sucroclastic activity of living cells of S. cerevisiae and of invertase solutions obtained therefrom has been found, within experimental error, to be identical. 3. The region of living yeast cells in which invertase exerts its physiological activity changes its pH freely and to the same extent as that of the suspending medium. It is suggested that this may indicate that this intracellular enzyme may perform its work somewhere in the outer region of the cell. 4. In using live cells containing maltase, no evidence of increased sucroclastic activity around pH 6.9, due to the action of Weidenhagen''s α-glucosidase (maltase), was found.