VESICLES ASSOCIATED WITH CALCIFICATION IN THE MATRIX OF EPIPHYSEAL CARTILAGE

Vesicles have been identified within the cartilage matrix of the upper tibial epiphyseal plate of normal mice. They were seen at all levels within the plate and usually did not appear to be in contact with cartilage cells. Vesicles were concentrated within the matrix of the longitudinal septa from the proliferative zone downward. They varied considerably in size (~300 A to ~1 µ) and in shape. They were bounded by unit membranes, and contained materials of varying density including, rarely, ribosomes. A close association was demonstrated between matrix vesicles and calcification: in the lower hypertrophic and calcifying zones of the epiphysis, vesicles were found in juxtaposition to needle-like structures removed by demineralization with ethylenediaminetetraacetate and identified by electron diffraction as hydroxyapatite and/or fluorapatite crystal structure—the former being indistinguishable from the latter for most cases in which electron diffraction methods are employed. Decalcification also revealed electron-opaque, partially membrane-bounded structures within previously calcified cartilage of the epiphyseal plate and underlying metaphysis which corresponded in size and distribution to matrix vesicles. It is suggested that matrix vesicles are derived from cells and that they may play a role in initiating calcification at the epiphysis.     

ELECTRON MICROSCOPY OF CARTILAGE AND BONE MATRIX AT THE DISTAL EPIPHYSEAL LINE OF THE FEMUR IN THE NEWBORN INFANT

An examination of the fine structure of cartilage and bone matrix at the distal epiphyseal line of the femur of a newborn infant has revealed the following information. Cartilage matrix is composed of a network of widely spaced fibers without obvious periodic banding. Calcification is first seen about the level of the third chondrocyte capsule distal to the furthest penetration of the capillaries. It starts as a haphazard deposition of crystals which have no obvious relationship to the location of the fibers. The process of calcification is completed before ossification commences but the central zone of matrix remains only partly mineralized. Bone matrix is formed over a bar of calcified cartilage. Fibers, recognizable as collagen, are deposited in a loose network in a narrow zone between the osteoblasts and cartilage. These fibers are 2 to 5 times as wide as the fibers in epiphyseal cartilage. Calcification then begins in the osteoid, crystals being first laid down irregularly on or close to the fibers. As they increase in number, the crystals tend to line up along the fibers and eventually are arranged so that the periodicity of the underlying collagen is emphasized. In such an area the fibers are more tightly packed than when uncalcified. There is no change observed in the calcified cartilage at this level. The extracellular matrices of this epiphyseal cartilage and bone can be distinguished from one another in the electron microscope.     

鼠胚胎运动神经元胫神经内种植的观察

目的：观察胚胎运动神经元移植至入肌点前神经内的存活情况。方法：取孕１２天胎鼠运动神经元,种植于成鼠入肌点前胫神经内,于实验后９、２２周取材作尼氏、Ｗｅｉｌ氏、肌动蛋白免疫组织化学、ＡＴＰ酶组织化学及氯化金染色观察。结果：胚胎运动神经元在周围神经干内能存活和发育,并减缓失神经骨骼肌及运动终板的萎缩     

Gas7在大鼠关节软骨中的表达及意义

目的探讨生长休止蛋白7（Gas7）在成年大鼠关节软骨中的表达及意义。方法雄性SD大鼠（3个月、12个月）各12只。取膝关节和股骨上端关节部分,经脱钙石蜡包埋并切片,采用HE染色和免疫组化SABC法检测。检测各关节软骨组织中Gas7的表达及其定位。结果关节软骨切线层与移行层Gas7的表达呈现强阳性,而在辐射层及软骨钙化层则弱阳性或阴性。结论Gas7在成年大鼠关节软骨各层细胞的表达不同,可能与各层软骨细胞的生长发育及代谢状况有关     

CARTILAGE CELL PROLIFERATION IN THE TAIL-VERTEBRAE of NEW-BORN RATS

Cartilage cell proliferation has been studied in the tail-vertebrae of new-born rats. At 1 day the median cycle time for cartilage cells was about 22 hr; G¹+ 1/2M, S, and G²+ 1/2M being 6.8 ± 2.5, 11.6 ± 2.2, and 4.6 ± 2.0 hr respectively. At 7-10 days, cell proliferation is confined mainly to the lower half of the epiphysis. Here cycle times are longer, about 3 1/2 days in the most active region. Differences in cycle times appear to be due to either a lengthening of G¹ or the entry of cells into a resting state. Changes in cartilage cell kinetics are discussed in relation to the structure and function of the epiphysis.     

A QUANTITATIVE STUDY OF THE MITOTIC ACTIVITY IN THE SUBEPENDYMAL PLATE OF ADULT RATS

A quantitative study of the mitotic activity of the cells of the subependymal layer in the rat brain has shown that mitotic activity decreases with the increase in age of the animals. Mitotic activity is still found in rats 16 months old and in the case of animals of two strains of rats, of this age, the mitotic count is significantly higher in males than in females.
The relationship between a reduced rate of brain growth and the decline in mitotic activity and the significance and importance of the higher mitotic count in the subependymal plate of 16-month-old males compared with similar females is discussed.     

CELL KINETICS OF GROWTH CARTILAGE IN THE RAT TIBIA I. MEASUREMENTS IN YOUNG MALE RATS

Cell kinetic parameters for the proximal growth plate of the tibia have been measured in young rats. Analysis of a pulse labelled mitosis study gave values of 55 ± 40 hr for the cycle time and 6.5 ± 0.3 hr for the synthesis time in 6-week-old rats. The results of a simulated continuous labelling experiment agreed with this data and provided further information on the size and proliferation rate of the stem cell zone. Diurnal variations in mitotic index and labelling index in the tissue have been investigated.     

EPIPHYSEAL STIMULATION IN THE LOWER EXTREMITIES

Epiphyseal stimulation to correct disparity in the length of lower extremities was done in 12 children. The total number of procedures was 15. In 11 of the 15 instances the operation was beneficial. Ivory pegs were used in some cases, brass screws in others and multiple drill holes in still others. There seemed to be no difference between them in the amount of stimulation brought about.Stimulation persisted for from six to ten months after operation.Complications that may occur are varus or valgus deformities, delay in growth, complete fusion, or infection. To prevent varus or valgus deformity, both medial and lateral sides may be stimulated simultaneously. Great care must be taken to place the screws no closer than one-fourth inch to the epiphyseal plate to avoid trauma which may delay rather than stimulate growth. Late infection may be obviated by the use of absorbable materials.The increase brought about by stimulation procedures is probably attributable to hyperemia following subperiosteal stripping.     

GROWTH HORMONE AND CARTILAGE CELL DIVISION IN HYPOPHYSECTOMIZED RATS

The effects of growth hormone on cell division in the growth cartilage of normal and hypophysectomized rats have been studied by autoradiography with tritiated thymidine. Following hypophysectomy the percentage labelling fell to 1.5-2%, about one fifth of that found in normal animals. Following injection of 100-1600 μg of bovine growth hormone, the percentage labelling increased after a delay of 8-16 hr, the delay, the rate of rise and the maximum reached being dose dependent. Single or repeated doses of growth hormone produced no significant change in normal young rats.     

中国蓝浆果生产现状

全面报道了蓝浆果(Vaccinium L.spp.)在中国的生产情况,共分为南、北两大区域.北区是指以吉林省为主的东北地区,南区指长江以南广阔的酸性红壤土地区.果用野生种只分布在东北地区.自20世纪80年代起开始引种欧美栽培品种,共达60余个.在北区以吉林农业大学为主,在南区以江苏省·中国科学院植物研究所为主,采用组培和扦插方法繁殖,南、北两区均各有年产百万株以上苗木的能力.在南、北两区的适宜地区,如吉林、江苏和贵州等省,都已选出各自的适栽品种,栽培后的产量和果实质量分别均可达到国外优良水平,显示了蓝浆果在中国发展的巨大前景.     

~(125)Ⅰ—蜂毒肽在小鼠体内分布、吸收、排泄的研究

以氯胺T为氧化剂参照Hunter和Greenwood的多肽类化合物的碘化标记法,制备了~(125)I—标记的蜂毒肽在小鼠体内分布、吸收、排泄的研究,实验证明小鼠肌注~(125)I—蜂毒肽后,吸收很快,主要分布部位为肾、肺、心、肝、小肠、关节、脾与肌肉,脑组织中含量很少,肌肉注射后5分钟血液中含量可达70％,~(125)—I蜂毒肽主要经肾排泄,肌注后30分钟肾脏浓集最高,而尿液中以1.5小时为最高,而粪便中排泄少。     

微量元素在大鼠体内的分布

为了研究微量元素在大鼠体内的分布,本实验将大鼠分为两组,喂镍组大鼠每天灌喂1％硫酸镍0.25毫升,另一组大鼠喂水作对照,一个月后,处死全部大鼠,取鼻咽、气管、食管、胃、小肠、心、肝、脾、肺、肾、大脑、颅骨及皮毛等13种器官和组织,用发射光谱技术测定微量元素的含量。结果表明,喂镍组大鼠的鼻咽、气管、食管、肺、颅骨、心、脾和肾的镍含量显著地高于正常组(P<0.01),实验组大鼠鼻咽的镍含量明显增高这一事实,可以解释硫酸镍在诱发大鼠鼻咽癌的作用。     

LYSOZYME IN EPIPHYSEAL CARTILAGE : IV. Embryonic Chick Cartilage Lysozyme—Its Localization and Partial Characterization

The localization of chick embryonic lysozyme was determined by two techniques: by studying the rate of release from the tissue during sequential enzymatic digestion and by immunocytochemistry. Both techniques indicate that, in this tissue, lysozyme is primarily extra-cellular. Cartilage lysozyme was isolated and partially characterized and found to be identical with egg white lysozyme in its immunologic and enzymatic behavior. In addition, a method for the isolation of large numbers of viable chondrocytes is described.