摘要:

AbstractSuspensions of thymic lymphocytes, 60–80% of which had been labeledin vivowith H3‐thymidine, were injected intravenously into 54 homologous rats and 22 isologous mice. Radioautographs2of blood and of tissues were analyzed. The cells rapidly disappeared from the blood, although less rapidly in the isologous than in the homologous systems. A large fraction was still present in the tissues during the first post‐injection day. In the first hour many were arrested in the lung, some of which were later redistributed to other organs. At later intervals the spleen contained the greatest concentration, followed by lymph nodes and bone marrow. Cells were found occasionally in the duodenal mucosa, in mice only, and in no case did they reach the thymus. A few survived in both rats and mice for as long as seven days.Only one labeled cell was seen in mitosis. There was evidence of transformation to erythroblasts in the liver, spleen and bone marrow; to myelocytes in the bone marrow; and to macrophages in the spleen. Label from some of the cells dying in the liver apparently was reutilized by the Kupffer

ISSN:0003-276X    

DOI:10.1002/ar.1091500202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractThein situthymus of the guinea pig was labeled locally with H3‐thymidine and sections of various tissues analyzed by radioautography for the location of labeled cells which might have left the thymus from 30 minutes to three days after labeling. Labeled lymphocytes were located especially in the mesenteric lymph nodes and spleen, giving direct evidence for the migration of thymocytes under near‐physiological conditions. Only a few cells were found in the bone marrow, and none in the liver. The identified cells were not seen to be undergoing subsequent proliferation, but about one‐fourth of them were transforming to other cell types ‐ plasma cells, heterophil granulocytes, reticular cells, and macrophages. The fate of another portion of the cells seemed to be loss to the gut lumen through the mucosa. These data suggest that a normal function of the thymus of the adult guinea pig is the proliferation of a population of pluripotential stem cells which, after migration to other tissues, may further differentiate under appropriate stimulus. Possible applications of the local labeling technique are in

ISSN:0003-276X    

DOI:10.1002/ar.1091500203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractSections for electron and light microscopy were easily prepared from mixtures of Dow Epoxy Resins 332 and 732 (D.E.R. 332 and D.E.R. 732) cured with dodecenyl succinic anhydride (DDSA) and DMP‐30. The most useful formula contained 46.7% D.E.R. 332, 20% D.E.R. 732, and 33.3% DDSA, plus 2% DMP‐30. Stronger sections were derived from a preparation containing 31.6% D.E.R. 332, 15.8% D.E.R. 732, and 52.6% DDSA, plus 2% DMP‐30. Harder resins were made by reducing the amount of D.E.R. 732 incorporated in the mixtures. When prolonged infiltration was required polymerization was slowed by substituting DMP‐10 in place of the more reactive DMP‐30. Compressed sections were easily restored to their proper size by the vapors of chloroform, dichloroethylene or xylene. The sections were strong enough to withstand intense electron beams on bare 150 mesh copper grids. The inherent contrast was good without staining, but additional contrast was obtained by brief treatment with aqueous solutions of lead or uranyl salts. Sections for light microscopy could be stained by water soluble b

ISSN:0003-276X    

DOI:10.1002/ar.1091500204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to determine the dimensions of capilaries in various tissues,in vivo, in frogs, mice, and pups. Capillaries were measured in the web, strap muscles of the neck, mesentery and bladder of frogs, and in the mesentery of mice and pups. The light source was a fused quartz rod transilumination apparatus. In all cases the exposed tissues were kept moist by a continuous flow of Ringer's solution over their surfaces.The mean values found for the tissues of the frog are web 11.94 μ, skeletal muscle 11.30 μ, mesentery 11.97 μ, and bladder 11.40 μ. The mesenteric capillaries of the mice and pups had a mean value of 4.64 μand 7.36 μ respectively.Difficulties encountered during the course of observation included vibrations of the optical equipment, movement of the tissue under the microscope, fogging of the objective lens, and the determining of which of the microscopic vessels were “capillaries.”A statistical analysis of the data indicates that the variance in the measurements recorded on the capillaries of a single animal is greater than the variance from animal

ISSN:0003-276X    

DOI:10.1002/ar.1091500205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractThe effects of hyper‐ and hypothyroidism on fetal development and on the postnatal maturation of the central nervous system was studied in the rat. Our observations indicated that the development of the rat fetus, as measured by birthweight and skeletal maturation of the newborn animal is not markedly influenced by presence or absence of thyroid hormone during the prenatal stage.Availability of thyroid hormone is a more critical factor with respect to maturation of the nervous system taking place in the postnatal animal.Delay in cerebellar maturation and delay in increase in dry weight of cerebrum and cerebellum were noted in hypothyroid rats. A transitory acceleration of oxygen consumption of these structures during their maturation was also noted in hyperthyroid litters.A more permanent suppression of learning behavior and of the thermoregulating mechanism was observed in young hypothyroid rats deprived of thyroid hormone since birth.It is concluded that requirements for thyroid hormone during development of the rat are limited to a critical period coinciding with the first two to three weeks of postnatal ag

ISSN:0003-276X    

DOI:10.1002/ar.1091500206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractThe rate of skeletal maturation as indicated by ossification of bony elements of the central and appendicular skeleton was compared in two groups of hypothyroid young rats, raised at 20°C and 30°C constant environment respectively.Hypothyroidism was induced by feeding 0.2% propylthiouracil mixed with the food in powdered form to pregnant rats starting on the fifteenth day of gestation and continuing this treatment to the suckling mother until their litters had reached weaning age.The appearance of epiphyseal centers, of carpal and tarsal centers, middle phalanges and femoral and tibial processes and caudal vertebrae 7–27 is delayed in hypothyroid newborn rats over that of normal controls. Hypothyroid rats raised at 20°C lag more severely behind the controls with respect to skeletal maturation, than do hypothyroid rats raised at 30°C. The latter are intermediate or in some instances their rate of skeletal maturation resembles that of the control group.The possible significance of the demonstration of diminished requirements for thyroid hormone by the developing rat for studies attempting to identify mechanisms of hormone action in development is briefly disc

ISSN:0003-276X    

DOI:10.1002/ar.1091500207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractAdult virgin females were made pseudopregnant by cervical stimulation and four days after stimulation the uteri were traumatized with a thread. The animals were autopsied 24, 48, 72, 96, and 120 hours after trauma. Frozen sections of the deciduomata were sectioned on the cryostat. For the identification of phosphorylase the sections were placed in the substrate containing 50 mg glucose‐1‐phosphate (G‐1‐P), 10 mg muscle adenylic acid, 15 ml distilled water, 10 ml 0.2 M acetate buffer (pH 5.8), 25 units of insulin and 5 mg of glycogen. To demonstrate uridinediphosphoglucose (UDPG)‐glycogen transferase sections were placed in the substrate containing 50 mg UDPG, 10 mg glycogen, 20 mg Versene, 10 mg G‐6‐P, 14 ml distilled water, 10 ml 0.2 M tris buffer (pH 7.4) and 1 ml absolute alcohol. Following incubation for one hour at 37° the sections were treated with either Lugol's or Gram's solution until the color developed. A positive response for phosphorylase was a blue‐black color while a red‐purple color indicated UDPG‐glycogen transferase. The periodic‐leucofuchsin technique was used to identify glycogen and hemotoxylin and eosin sections were studied for general morphology.Glycogen and phosphorylase were observed in the decidual cells. However, the enzymatic activity was not as intense or as extensive as the polysaccharide. UDPG‐glycogen transferase activity was observed in only two of the 50 deciduomata studied. On the basis of the present observations it may be suggested that the important pathway for glycogen synthesis in the decidual cells is from G‐1‐P by the action of phosphorylase and not from UDPG by the action

ISSN:0003-276X    

DOI:10.1002/ar.1091500208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractA comparative histological and histochemical study of the gastric mucosa was done with the frog, mouse, rat, hamster, guinea pig, rabbit, cat, dog and man. Enzymatic histochemical studies were done to demonstrate acid phosphatase (PbS and azo‐dye methods), thiamine pyrophosphatase (TPP‐ase) and NADH2tetrazolium reductase activity. Cytoplasmic organelles were stained in some cases by three of the above methods i.e. acid phosphatase (PbS) activity marked the lysosomes, TPP‐ase activity marked the Golgi apparatus and NADH2tetrazolium reductase activity marked the mitochondria. The acid phosphatase activity of the four major cell types was markedly different in the various species. The activity shown by both methods in individuals of a given species coincided well except in the rabbit and the dog. TPP‐ase activity demonstrated the Golgi region in the surface cells of all species except the guinea pig and the frog. The Golgi zones of zymogen cells showed strong activity only in the cat, while the parietal cell Golgi was not demonstrated in any of the species. NADH2tetrazolium reductase activity in the parietal cells was strong in all animals except the mouse and the rat where staining was faint. The relationship between the lysosomes and the Golgi apparatus, as demonstrated histochemically in the gastric cells of the nine species, is discussed. The functional significance of these different enzymatic patterns has yet to be det

ISSN:0003-276X    

DOI:10.1002/ar.1091500209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractCholinesterase (ChE) distributions in the epithelial and smooth muscle cells and in the peripheral nervous plexus of the reproductive ducts of the male rat are dependent on male sex hormones. Castration results in establishment of a low maintenance level of apical enzyme activity in the epithelial cells; smooth muscles and the nerve plexus of the vas deferens and cauda epididymidis also show reduced enzyme reactions. Testosterone treatment restores the normal enzyme relations in the epithelium and smooth muscles. Estradiol is partially effective, but reaction intensities do not attain normal distrbutions and proportions. Reductions in relative numbers of ChE positive nerve plexus fibers and their enzyme reactivity, and recession to outer muscle layers occur in castrates, but better recoveries follow after testosterone than after estradiol treatments. The results are interpreted to be in agreement with other data relating to smooth muscle behavior and its neural and hormonal regulation. Epithelial cell differentiation is complete in testosterone treated castrates, but is incomplete in estradiol treated cases, although ChE synthesis and duct growth occurs in the latter.

ISSN:0003-276X    

DOI:10.1002/ar.1091500210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY

摘要:

AbstractA cephalometric radiographic appraisal of vertical skull growth occurring during the interim of one year was made on 71 caucasoid males at the Baylor University College of Dentistry, Dallas, Texas. The subjects were from 22 to 34 years of age. The dimensions assessed were the total skull height, the anterior cranial height, total facial height, upper facial height. and lower facial height. A significant increase was shown to occur in all the dimensions over a period of one year except in the dimension of anterior cranial height. It was concluded that skull growth does occur in male adults after the age generally accepted as that of maturity.

ISSN:0003-276X    

DOI:10.1002/ar.1091500211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1964

数据来源: WILEY