摘要:

AbstractCalcium‐deprivation of three weeks duration causes marked degenerative changes in the shell gland mucosa of the laying hen. The height of the columnar epithelium decreases, but the secretory granules in the columnar epithelial cells and the cilia on the apical cells of the columnar epithelium are preserved. The tubular glands decrease in size and number. The microvilli surrounding the tubular gland lumen disappear. The cytoplasm of the tubular gland cell contains autophagic vacuoles (cytolysomes) and large pigment accumulations, presumably lipofuscin. The changes are due to dietary calcium deficiency, apparently mediated by decreased sex steroid secretion and decreased stimulation of the oviduct. These changes are totally reversible, since the fine structure of the shell gland mucosa of calcium‐deprived hens returned to a normal laying diet does not show any signs of degeneration and is identical with the fine structure of the shell gland mucosa of the laying control bi

ISSN:0003-276X    

DOI:10.1002/ar.1091640201

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe technique of organ culture was used to test the effects of various pituitary hormones and norepinephrine on the size of brown and white adipose cells of mice. The hormonal effects were measured by means of histologic analysis and cell width measurements. A concentration of 10 μg/ml of somatotropin (STH), adrenocorticotropin (ACTH) or lipotropin (LPH) was sufficient to reduce the size and content of intracellular lipid in white fat cells while a concentration of 100 μg/ml was required for similar effects on brown fat cells. Norepinephrine, at concentrations of 0.1 μg/ml or 1.0 μg/ml, was sufficient to reduce markedly the size and lipid content of both types of adipose cells. On a molar basis, these hormones acted in a similar range of concentration. The reduction in size and amount of intracellular lipid in brown and white adipose cells by STH, ACTH, and LPH were prevented when combined with 10 μg/ml of insulin. Insulin prevented the lipid depletion effect of norepinephrine in brown but not white adipose c

ISSN:0003-276X    

DOI:10.1002/ar.1091640202

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

年代:1969

数据来源: WILEY

摘要:

AbstractOnset, frequency and characteristics of the spontaneous calcification which occurs in hearts of mice of the DBA strain have been studied. Calcified myocardial lesions developed as early as 25 days of age. A limited inflammatory response was associated with the fine mineral granules of early lesions. With age, sites of calcium deposition became larger and agranular. There was no evidence of inflammation at such loci and adjacent connective tissue did not increase significantly. In the oldest animals (older than 90 days), fibrous encapsulation of calcified sites was typical. Calcareous epicarditis appeared by 30 days; was minimal (8%) through 90 days, and then rose sharply in incidence (50%) in older animals. Epicardial calcification was restricted to the right ventricle. In general the calcified lesions increased with age and were not related to sex. Incidence of all lesions was 17% by 30 days of age, 80% within 90 days, and 94% in mice older than 90 days.

ISSN:0003-276X    

DOI:10.1002/ar.1091640203

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

年代:1969

数据来源: WILEY

摘要:

AbstractIn order to verify the concept that growth hormone and prolactin are contained in two different populations of acidophils, sections of Bouin‐fixed rat hypophyses were stained immunochemically. For this purpose the histochemical demonstration of peroxidase was utilized after sequential application to the tissue section of rabbit antiserum to human growth hormone (or antiserum to rat prolactin) followed by application of peroxidase‐labeled sheep antiserum to rabbit gamma‐globulin. It was found that growth hormone cells and prolactin cells, when revealed immunochemically, corresponded structurally to cell types that could be differentiated with reasonable certainty in sections stained with the Masson trichrome procedure. When delineated immunochemically, growth hormone cells were larger and more densely arranged in the adult male than in the intact female; they exhibited little change in the female after ovariectomy. In contrast, prolactin cells were large and frequent in the female hypophysis but were small and less frequent in the male and in the female after ovariectomy. By double‐staining, growth hormone and prolactin cells were differentiated in the same section. It was concluded that (a) growth hormone and prolactin are contained in, and presumably secreted by, two different populations of acidophils; and (b) the Masson procedure permits a reasonably accurate differentiation of the two cel

ISSN:0003-276X    

DOI:10.1002/ar.1091640204

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

年代:1969

数据来源: WILEY

摘要:

AbstractCertain members of the extinct reptilian group from which mammals evolved possessed both a dens and an atlas body. Available paleontologic evidence supports the conclusion that the dens evolved as an addition to the atlas body. There‐fore, the dens is not homologous with the atlas body as is generally claimed on the basis of supposed developmental evidence. The atlas body is large in the most primitive of living mammals, the monotremes, which also possess a dens of typical mammalian proportions. In metatherian and most eutherian mammals, both a dens and an atlas body remnant of variable size are present. The development of the dens in the Virginia opossum,Didelphis marsupialis, confirms the fact that the dens arises from, but does not replace, the atlas body anlage. The dens evolved as a functional replacement of the atlanto‐axial articular processes which were lost when the mammalian atlanto‐axial joint became specialized for rotational mov

ISSN:0003-276X    

DOI:10.1002/ar.1091640205

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

年代:1969

数据来源: WILEY

摘要:

AbstractSympathetic ganglia of sixCnemidophorus neomexicanuslizards were fixed by immersion with glutaraldehyde or a combination of glutaraldehyde and paraformaldehyde. All ganglia were post‐fixed in 1% osmium tetroxide and embedded in Epon.Neuronal somata and processes of stellate ganglia were ensheathed typically by capsular cell cytoplasm and membranes; however, parts of some processes were invested only by basement membrane. Axo‐somatic, axo‐dendritic and axo‐axonal synapses were observed. Pre‐ and post‐synaptic processes contained 200 Å neurotubules, 100 Å neurofilaments, 225–500 Å presumptive glycogen granules and occasional multivesicular bodies. Presynaptic endings contained 500–700 Å “clear” vesicles and a few dense‐cored vesicles of 600–1100 Å.Aggregates composed of 225–500 Å granules, presumably glycogen, were frequently found in peripheral perikaryal positions in intimate association with lipid droplets. Clusters of particles within somata were also found which resembled ribosomes but were not associated with endoplasmic reticulum or vesicular membranous elements. These clusters, perhaps “areticular Nissl substance,” were associated in some instances with fibrillar material or lattice‐like granular structures. Abundant and frequently large lipid droplets were observed in proximity to th

ISSN:0003-276X    

DOI:10.1002/ar.1091640206

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

年代:1969

数据来源: WILEY

摘要:

AbstractCells of the vaginal epithelium of ovariectomized mice undergo differentiation in response to estrogen or progesterone injection. Estrogen causes an increase in number of cytoplasmic filaments in the basal and newly formed spinous layer and mucification of surface cells already present. The cells derived from the basal layer under estrogen influence later form a keratinized epithelium. Progesterone causes heightening and mucification of surface cells and invasion of leucocytes into the epithelium without mucification or keratinization of other cells. When estrogen is followed two days later by progesterone, spinous and more superficial cells are lost and replaced my mucous cells derived from the basal layer. Although the fine structure of basal and spinous cell cytoplasm looks identical, the spinous cells do not form mucous cells under progesterone influence. The reverse sequence of progesterone followed by estrogen produces a low epithelium which is then replaced by a keratinized epithelium. The surface mucous cells present during progesterone influence do not keratinize, however. Thus, fine structural features of basal cells typical for the influence of a given hormone do not limit or characterize the potential of daughter cells derived from that layer. Conversely, when hormones are used in sequence, cells which leave the basal layer under the influence of one hormone do not acquire the fine structural features characteristically produced by the second hormone used, even though basal cells are readily altered.

ISSN:0003-276X    

DOI:10.1002/ar.1091640207

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

年代:1969

数据来源: WILEY

摘要:

AbstractFresh‐frozen, serial cross–sections of the transversus abdominis muscle of four mature chickens (98 fibers) were examined to determine structural and histochemical characteristics throughout the entire length of skeletal muscle fibers. Fiber diameter and nicotinamide adenine dinucleotide diaphorase (NAD‐D) and myosin adenosine triphosphatase (ATPase) activities were used as criteria to classify fibers as Type I or II. Measurements were made at 10 to 22 locations along the length of the fibers. An unimodal distribution of mean fiber diameters ranging from 48 μ to 86 μ was found. Fibers did not appear larger in the belly of the muscle than near the ends. Although small fluctuations in fiber diameter occurred through the length of a fiber, large and small fibers tended to remain relatively large or small at each location. NAD‐D activity was either consistently high or low throughout the length of a fiber. Likewise, myosin ATPase activity was either high or low for an entire fiber. It is concluded that skeletal muscle fibers maintain rather uniform structural and histochemical characteristics along their enti

ISSN:0003-276X    

DOI:10.1002/ar.1091640208

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

年代:1969

数据来源: WILEY

摘要:

AbstractThe distribution of acid hydrolytic activities in rat uterine epithelial cells during post‐partum involution was examined by light and electron microscopic cytochemistry. Acid phosphatase, β‐glucuronidase, N‐acetyl‐β‐glucosaminidase and E600‐resistant esterase (cathepsin) increased during the period of involution and the electron cytochemical preparations revealed the lysosomal nature of the acid hydrolytic positive particles visualized by light microscopy.The newly formed particles included primary lysosomes, in the form of Golgi vesicles, vacuoles, and secondary lysosomes such as dense bodies and autophagic vacuoles. This apparent increase in lysosomal activity during uterine involution is in agreement with similar patterns observed in the course of tissue regressi

ISSN:0003-276X    

DOI:10.1002/ar.1091640209

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

年代:1969

数据来源: WILEY