摘要:

AbstractA modification of the plasma membrane of intestinal epithelial cells consisting of an apparent thickening of the inner lamella of the unit membrane is described. The evidence indicates that the thickening can be attributed to a piling‐up of stainable, granular material along the inner surface of the plasmalemma. Similar granules could be found in the cytoplasm, mostly in the region of the terminal web, and in mitochondria. Cells showing these changes were usually devoid of ribosomes and contained many smooth surfaced cytoplasmic vesicle

ISSN:0003-276X    

DOI:10.1002/ar.1091560402

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe autonomic innervation to the eye of monkey, cat and rabbit was studied using a sensitive histofluorometric method for adrenergic nerves and the acetylcholinesterase technique for cholinergic nerves.In the monkey cornea adrenergic nerves are absent while they are numerous in both the cat and rabbit. There is marked species variation in the amount of autonomic innervation to the filtration area. The iris sphincter and the ciliary muscle have a dual innervation but the relative amount of the adrenergic component to these structures varies widely. The ciliary process in every case has a plentiful adrenergic nerve supply. In the choroid a heavy adrenergic innervation apparatus approaches the choriocapillaris. A layer of fluorescent terminals is found in the retina at the junction of the inner nuclear and inner plexiform layers in all three species. In the adjoining part of the inner nuclear layer lie scattered catecholamine‐containing amacrine cell

ISSN:0003-276X    

DOI:10.1002/ar.1091560403

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

年代:1966

数据来源: WILEY

摘要:

AbstractElectron microscopic examination of rabbit erythroblasts revealed the presence of microtubules, 210–270 Å in diameter, composing a marginal band in the cell periphery. This band was composed of 6–8 microtubules arranged more or less parallel to one another. Transverse sections indicated that 16–18 tubules may comprise the band. The latter appeared to be poorly formed or absent in reticulocytes and erythrocytes. Microtubules were also found in the deeper regions of the cytoplasm as well as composing th emitotic spindle of dividing erythroblasts. With the exception of the procentriole and the asters and chromosomes of dividing cells, microtubules were not continuous with other organelles. The function of the marginal band is interpreted as imparting elasticity and resiliency to the cell, a cytoskeleton responsible for maintenance of cell form. “Coated” micropinocytotic vesicles in erythroblasts, hepatocytes, and reticulo‐endothelial cells are also described. Most of the “coated” vesicles in erythropoietic cells did not contain ferritin. It is suggested that, in the “coated” vesicles, ferritin may be in a highly dilute form or, alternatively, that its relative absence may indicate that iron is obtained predominantly through the plasma transferrin system rather than through incorporation of iron in

ISSN:0003-276X    

DOI:10.1002/ar.1091560404

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

年代:1966

数据来源: WILEY

摘要:

AbstractMeasurements of volume of the thyroid, diameter of follicles and height of follicular cells were made under normal or experimental condition of unilateral thyroidectomy in late fetal and newborn rats. During perinatal days, the thyroid did not enlarge, the diameter of follicles was reduced and the height of follicular cells lowered. Unilateral thyroidectomy in fetuses on day 20 of pregnancy caused two days later a significant increase in the ratio of the volume of remaining lobe of thyroid to body weight. The height of follicular cells was increased in a unilaterally thyroidectomized fetus when compared with that in a litter‐mate control fetus. In newborn rats, the unilateral thyroidectomy on day 1 of life also caused two days later a significant increase, though less than that observed in fetuses, in the ratio of thyroid volume to body weight. The height of follicular cells was not increased.The observations support the view that in the rat the pituitary‐thyroid system begins to function before birth and that the founctioning of the system is slightly reduced just after bi

ISSN:0003-276X    

DOI:10.1002/ar.1091560405

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe growth of duodenal crypts of Lieberkühn was investigated in male Sherman rats subjected to thyroidectomy, and/or castration. Histological sections were studied, counting interphase nuclei and mitoses in 25 longitudinally sectioned crypts per animal. At 49 gm body weight, initial control animals had an average of 65.8 ± 2.4 cells per crypt section, and 80 days later, sham‐operated controls weighed 269 gm and had 91.4 ± 5.1 cells per crypt section. There were only 75.0 ± 3.7 cells per crypt section 80 days after thyroidectomy, while castrates had 97.0 ± 2.6 cells per crypt section. Thyroidectomy combined with castration produced results similar to thyroidectomy alone, 74.0 ± 2.5 cells per crypt section. Treatment of such doubly operated rats with testosterone during the last 42 days of the experiment significantly increased the cell number, to 82.7 ± 2.8 per crypt section, while thyroxine increased it to 100.8 ± 4.3. Thus, in the rat, the number of cells per crypt increases between juvenile and adult stages, and this growth is subject to endocrine regulation, particularly by the thyroid.The mitotic index of crypt cells increases with age, from 3.9 ± 0.1% at 49 gm body weight, to 5.2 ± 0.3% at 269 gm body weight. Castration did not interfere with this increment, but it was reduced in the absence of thyroid hormone, and was restored by the injection of thyroxine to thyroidectomized castrates.Finally, from related observations in previously reported and unpublished experiments, it is suggested (1) that the influence of thyroid hormone on crypt cell number may be mediated, at least in part, through an action on growth hormone release from the anterior pituitary and (2) that the rate of change in cell number with age may be determined in some measure by a change in the rate of cell displacement toward the villus tip, in addition to a change in mi

ISSN:0003-276X    

DOI:10.1002/ar.1091560406

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe sphenomandibular (tympanomandibular) ligament develops from Meckel's cartilage between the future petrotympanic fissure and the mandibular lingula. The superior attachment of this ligament has been described to attach to the sphenoidal spine.Fifty‐one cadaver half heads were dissected to study the superior attachment of this ligament. Forty‐five of the 51 ligaments were found to be attached in the area of the petrotympanic fissure, not directly to the sphenoidal spine. Six of the specimens had a thin fibrous slip which fanned out medially to the sphenoidal spine.Twelve additional cadaver specimens were decalcified and cut in various planes through the temporomandibular joint. All specimens showed a fibrous continuation of the ligament through the petrotympanic and/or squamotympanic fissures with an attachment to the malleus in the middle ear. When tension was applied to the ligament the malleus was seen to move.A 115 mm human fetus head was dissected. A ligamentous structure was seen to run from the medial side of the mandibular ramus to the future squamotympanic fissure area. When observed microscopically the ligament was continuous through the fissure and attached to the mall

ISSN:0003-276X    

DOI:10.1002/ar.1091560407

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

年代:1966

数据来源: WILEY

摘要:

AbstractStudy of an unselected population of adult laboratory rats demonstrates the presence of globule leucocytes in the bronchioles, bronchi, trachea, larynx and oropharynx. In the digestive tract, these leucocytes are seldom found in the antral part of the stomach but are abundant in the glandular stomach where they have been confused with mast cells. Numerous globule leucocytes also occur in the large and small intestines. Although most of these leucocytes are located in the epithelium rather than the connective tissue of themucous membranes of these organs, this pattern is reversed in the small intestine of normal rats. Globule leucocytes are present in essentially normal numbers in the trachea and larynx of axenic rats, but are less abundant than normal in the small intestine of these animals. The fine structure of the globule leucocyte and its characteristic inclusions is compared with that of other similar or possibly related cells and with that of the globule leucocyte of the fowl described recently by Toner.

ISSN:0003-276X    

DOI:10.1002/ar.1091560408

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe total calcium content as well as the calcium content of individual long bones has been measured in male and female rats from weaning to maturity and were found to be linear functions of body weight in both sexes. The calcium content of the total skeleton was a constant percentage of body weight in males but was a continuously increasing percentage of body weight in females. The calcium content of the tibia and femur expressed as a percentage of total body weight changed ten‐fold between weaning and maturity in females but hardly changed at all in males. In mature animals above 250 gm, calcium is distributed in the different bones of the skeleton in the same proportions in both sexes though females contain much more calcium at any given body weight than male

ISSN:0003-276X    

DOI:10.1002/ar.1091560409

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

年代:1966

数据来源: WILEY

摘要:

AbstractThe heart weight as well as the heart weight‐body weight ratios of 264 adult albino rats, 155 males and 109 females were analyzed. The large rats have significantly heavier hearts than small rats, but small adults have on the average significantly higher heart weight‐body weight ratios than large adults.The heart was partitioned and the ventricle weight‐body weight ratio was also determined. As would be expected boty the right and the left ventricles are heavier in large rats than in small rats. However, the small rats have on the average a significantly higher ventricle weight‐body weight ratio than large animals.Since there are highly significant differences between the weight of the heart of large and small animals, if heart weights are used in experimental work, rather than heart weight‐body weight ratios, the animals should have a narrow body weight range.It is thought that these data may be helpful to those who work on the heart o

ISSN:0003-276X    

DOI:10.1002/ar.1091560410

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

年代:1966

数据来源: WILEY

ISSN:0003-276X    

DOI:10.1002/ar.1091560401

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

年代:1966

数据来源: WILEY