American Journal of Anatomy最新文献

A study of the nucleus in the normal and hyperplastic liver of the rat 大鼠正常和增生性肝脏细胞核的研究

American Journal of Anatomy Pub Date : 2005-02-03 DOI: 10.1002/AJA.1000730106

N. M. Sulkin

引用次数: 21

Proliferation in the genital tract of the normal mature guinea pig treated with colchicine 秋水仙碱处理后正常成熟豚鼠生殖道内的增殖

American Journal of Anatomy Pub Date : 2005-02-03 DOI: 10.1002/AJA.1000730104

I. G. Schmidt

引用次数: 0

Liver extirpation and implantation in Amblystoma embryos with particular reference to blood formation 无瘤胚胎的肝脏切除和植入，特别涉及血液的形成

American Journal of Anatomy Pub Date : 2005-02-03 DOI: 10.1002/AJA.1000730105

W. Copenhaver

引用次数: 1

Scleral calcification and photoreceptor cell death during aging and exposure to chronic stress. 老化和暴露于慢性应激时的巩膜钙化和光感受器细胞死亡。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890108

W K O'Steen, A Brodish

{"title":"Scleral calcification and photoreceptor cell death during aging and exposure to chronic stress.","authors":"W K O'Steen, A Brodish","doi":"10.1002/aja.1001890108","DOIUrl":"https://doi.org/10.1002/aja.1001890108","url":null,"abstract":"Male and female Fischer 344 rats of three different ages (12, 18, and 25 months) have been examined for the presence of photoreceptor (PR) cell loss and for occurrence of scleral cartilage and bone formation. In addition, male and female rats, aged 11 months at the beginning of the experiments, were exposed to chronic stress for either 0.5, 2, 4, or 6 months. Photoreceptor cell death gradually increases during the aging process and is exacerbated by exposure to chronic stress. It is more severe in the peripheral than the central retina and exposure to stress increases this pattern of cell loss. The superior retina is more severely affected than the inferior hemisphere in aging and during stress. The incidence of scleral cartilage or bone formation increases with age in male and female rats, but with stress exposure an increase is seen in males only. Bone formations occur more frequently in male than in female animals and are almost always (97%) located in the superior hemisphere of the eye. Although there appears to be a direct relationship between photoreceptor cell death and the occurrence of scleral ossifications in group data, in individual eyes the bone formations are not always associated with severity of PR cell loss. The relationship of PR cell death and incidence of scleral ossification to gender and to exposure to stress supports a hypothesis for an endocrine basis of ocular aging.","PeriodicalId":50815,"journal":{"name":"American Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/aja.1001890108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13391849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 15

A morphologic study of bronchus-associated lymphoid tissue in turkeys. 火鸡支气管相关淋巴组织的形态学研究。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890104

J A Fagerland, L H Arp

{"title":"A morphologic study of bronchus-associated lymphoid tissue in turkeys.","authors":"J A Fagerland, L H Arp","doi":"10.1002/aja.1001890104","DOIUrl":"https://doi.org/10.1002/aja.1001890104","url":null,"abstract":"Bronchus-associated lymphoid tissue (BALT) in normal turkeys of ages 1 day and 1, 2, 3, 4, 8, and 18 weeks was examined by light microscopy and by scanning and transmission electron microscopy. Turkey BALT resembled other mucosa-associated lymphoid tissues; it was made up of a population of lymphocytes covered by a specialized epithelium different from typical pseudostratified ciliated columnar bronchial epithelium. There were distinct age-related differences in BALT structure. Bronchus-associated lymphoid nodules were larger and more numerous in older turkeys. In 1-day- to 2-week-old turkeys, the primary cell type of BALT epithelium was nonciliated cuboidal; in 2-week old turkeys it was squamous; and in turkeys older than 4-weeks of age, the epithelium was primarily ciliated columnar. In 1- to 4-week old turkeys, large numbers of intraepithelial lymphocytes disrupted the normal organization of the epithelium. In older turkeys, epithelial and lymphoid cells were in discrete compartments separated by connective tissue. Lymphocytes in 1-day-old turkeys were found in loose aggregates around venules and within the epithelium. In 1-week old turkeys, lymphocytes were organized into compartments of morphologically similar cells. By 3-weeks of age, lymphocytes were present in distinct germinal centers. Epithelial cells of BALT did not have large numbers of apical vesicles and thus were not structurally specialized for antigen uptake by endocytosis. However, the epithelial barrier appeared to be disrupted over lymphoid nodules, suggesting that antigen would be readily available to lymphocytes and phagocytes in BALT. Age-related differences in turkey BALT structure may have functional consequences with respect to the respiratory immune response.","PeriodicalId":50815,"journal":{"name":"American Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/aja.1001890104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13391845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 43

Three structures associated with the nucleolus in male rat germinal cells: round body, coiled body, and "nubecula" and general presence of round body at male meiosis. 雄性大鼠生殖细胞与核仁相关的三种结构:圆体、盘绕体和“核束”，雄性减数分裂时普遍存在圆体。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890103

M C Schultz

{"title":"Three structures associated with the nucleolus in male rat germinal cells: round body, coiled body, and \"nubecula\" and general presence of round body at male meiosis.","authors":"M C Schultz","doi":"10.1002/aja.1001890103","DOIUrl":"https://doi.org/10.1002/aja.1001890103","url":null,"abstract":"In addition to chromosomes and nucleoli, three structures, i.e., round body, coiled body, and nubecula, are encountered in the nucleus during the meiotic prophase in male rats. These structures have been examined by electron microscopy in random and serial sections. The round body is a finely fibrillar, proteinaceous structure closely associated with the granular component of a nucleolus in rat spermatocytes and young spermatids. A similar structure has been observed in man, the monkey Macaca mulatta, the gastropod Achatina fulica, and the insect Locusta migratoria. Together with evidence from the literature, these results support the view that the round body is of general occurrence in the male meiocytes of eukaryotes and may, therefore, play a role in meiosis. The coiled body is a group of electron-dense elements called \"coils\", which average 35 nm in width, except after mid-pachytene when their size almost doubles. The coils are composed of 2-nm-wide filaments and 8 to 10-nm-wide granules, both of which are ribonucleoprotein. The coiled bodies are interpreted to be groups of \"spliceosomes\", that is, structures containing heterogeneous RNA and small nuclear RNA. A remarkable feature of the coiled body is its temporary disappearance at early pachytene and its reappearance at late pachytene, possibly due to drastic changes in the turnover rate of its component RNAs. The nubecula is a newly identified nuclear inclusion, composed of weakly staining threads loosely organized into a 560 nm-wide spheroid. It has been observed only in early pachytene nuclei.","PeriodicalId":50815,"journal":{"name":"American Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/aja.1001890103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12864866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Nucleolar structure and synthetic activity during meiotic prophase and spermiogenesis in the rat. 大鼠减数分裂前期和精子发生核仁结构和合成活性。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890102

M C Schultz, C P Leblond

{"title":"Nucleolar structure and synthetic activity during meiotic prophase and spermiogenesis in the rat.","authors":"M C Schultz, C P Leblond","doi":"10.1002/aja.1001890102","DOIUrl":"https://doi.org/10.1002/aja.1001890102","url":null,"abstract":"The ultrastructure of nucleoli was examined in developing rat spermatocytes and spermatids, with the help of serial sections. In addition, the radioautographic reaction of nucleoli as examined in rats sacrificed 1 hr after intratesticular injection of 3H(5')-uridine and taken as an index of the rate of synthesis of ribosomal RNA (rRNA). Primary spermatocytes from preleptotene to zygotene have small nucleoli typically composed of fibrillar centers, a fibrillar component, and a granular component, within which are narrow interstitial spaces. During early and mid-pachytene, nucleoli enlarge to about nine times their initial size, with the fibrillar and granular components forming an extensive network of cords--a nucleolonema--within which are wide interstitial spaces. Meanwhile, there appear structures identical to the granular component but distinct from nucleoli; they are referred to as extranucleolar granular elements. Finally, from late pachytene to the first maturation division, nucleoli undergo condensation, as shown by contraction of fibrillar centers into small clumps, while fibrillar and granular components condense and segregate from each other, with a gradual decrease in interstitial spaces. In secondary spermatocytes, nucleoli are compact and rather small, while in young spermatids they are also compact and even smaller. Nucleoli disappear in elongating spermatids. In 3H-uridine radioautographs, nucleolar label is weak in young primary spermatocytes, increases progressively during early pachytene, is strong by the end of mid pachytene, but gradually decreases during late pachytene up to the first maturation division. In secondary spermatocytes and spermatids, there is no significant nucleolar label. In conclusion, rRNA synthesis by nucleoli is low in young spermatocytes. During pachytene, while nucleoli enlarge and form a lacy nucleolonema, rRNA synthesis increases gradually to a high level by the end of mid pachytene. However, during the condensation and segregation of nucleolar components occurring from late pachytene onward, the synthesis gradually decreases and disappears. The small, compact spermatids arising from the second maturation division do not synthesize rRNA.","PeriodicalId":50815,"journal":{"name":"American Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/aja.1001890102","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13391844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Ultrastructural changes in thyroid epithelium during involution of the hyperplastic thyroid gland. 甲状腺增生复旧过程中甲状腺上皮超微结构的改变。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890106

O Tachiwaki, J D Zeligs, S H Wollman

{"title":"Ultrastructural changes in thyroid epithelium during involution of the hyperplastic thyroid gland.","authors":"O Tachiwaki, J D Zeligs, S H Wollman","doi":"10.1002/aja.1001890106","DOIUrl":"https://doi.org/10.1002/aja.1001890106","url":null,"abstract":"The ultrastructure of the thyroid epithelial cell was examined at various time intervals after induction of involution of the hyperplastic thyroid gland. Thyroids were made hyperplastic by the feeding of thiouracil in a Remington low-iodine diet to male Fischer rats for 3 weeks. Involution was induced by replacing the thiouracil-containing diet with Purina Laboratory Chow, a high-iodine diet. During involution, organelles that play a role in the synthesis and secretion of thyroglobulin, such as the rough endoplasmic reticulum, Golgi apparatus, and apical vesicles, were well preserved and prominent features of the epithelial cell. The apical plasma membrane of many cells was highly irregular for approximately 2 weeks with signs suggesting rapid discharge of apical-vesical contents into the lumen of the follicle. Pseudopods and colloid droplets were present but were not very prominent features of the cell. No signs of extensive autophagy or obvious increased incidence of lysosomes were present, although there was an elevation in the incidence of small dense bodies starting about day 8, and prominent by 15 days. Some of these may be phagosomes formed from luminal debris. The observations indicate that involution of the hyperplastic thyroid in which there is maintenance of the protein synthetic apparatus and little sign of autophagy or death of the epithelial cells is remarkably different from phenomena occurring during involution of prostate or mammary glands.","PeriodicalId":50815,"journal":{"name":"American Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/aja.1001890106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13391847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Histologic changes in tissue components of the hyperplastic thyroid gland during its involution in the rat. 大鼠甲状腺增生复旧过程中组织成分的组织学变化。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890105

S H Wollman, J P Herveg, O Tachiwaki

{"title":"Histologic changes in tissue components of the hyperplastic thyroid gland during its involution in the rat.","authors":"S H Wollman, J P Herveg, O Tachiwaki","doi":"10.1002/aja.1001890105","DOIUrl":"https://doi.org/10.1002/aja.1001890105","url":null,"abstract":"Male Fischer rats were fed a low-iodine diet containing thiouracil for 21 days to produce hyperplastic thyroid glands, and then fed a high-iodine diet for various time intervals, from 5 hr to 180 days, in order to study the morphological changes that occur during involution. Thyroids were fixed by perfusion fixation and embedded in Epon. Sections were examined by light microscopy. Initially at 0 days of involution (at the time of the change to the high-iodine diet), follicular lumens were very narrow and capillary lumens were very wide. The capsule was thick and infiltrated with mononuclear leukocytes. No obvious changes occurred for 1 day after the change in diet, but shortly thereafter capillary lumens began to narrow. By 4 days, most capillary lumens were close to normal size; capillaries formed a more or less normal bed except that many were embedded in a relatively thick or wide interfollicular matrix. This matrix was largely gone by 21 days. Between 1 and 21 days, follicular lumens dilated progressively as colloid accumulated. The density of staining of the accumulated colloid varied from follicle to follicle, and this variation was also observed in older controls. Inflammatory cells gradually disappeared from the capsule and most were gone by 15 days. Starting at approximately 15 days and continuing to 180 days, one or more disintegrating cells were found in some lumen profiles. Colloid goiters were not observed in these rats even after several months of involution. Some lumens were rather large, however, and small fractions of the follicles, both small and large, were bounded by flat cells and resembled \"cold\" follicles morphologically.","PeriodicalId":50815,"journal":{"name":"American Journal of Anatomy","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1990-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/aja.1001890105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13391846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 26

Morphometric analysis of vertebrae and intervertebral discs as a basis of disc replacement. 脊椎和椎间盘的形态计量学分析作为椎间盘置换术的基础。

American Journal of Anatomy Pub Date : 1990-09-01 DOI: 10.1002/aja.1001890109

S Aharinejad, R Bertagnoli, K Wicke, W Firbas, B Schneider

引用次数: 52