摘要:

AbstractThis study demonstrates the ability of pituitary anlagen from 12‐ and 15‐day embryonic rats to undergo cytodifferentiation in a site distant from that of its normal juxtaposition with the hypothalamus.Pituitary anlagen (PA) were isografted from 12‐ and 15‐day‐old embryonic donors to under the kidney capsule of intact adult female rats. Seventeen days later the grafts were recovered and processed for light and electron microscopy (LM and EM). Four of six 12‐day and all five 15‐day PA grafts developed into adenohypophyseal‐like tissues. At the light as well as EM level, no consistent quantifiable differences could be detected between the glandular tissues that developed from the two different donor groups. While most of the cells within anterior pituitary‐like tissue were chromophobic at the LM level, some cells were stained positive with periodic acid‐Schiff and Orange G. Examination by EM revealed that most cells within the glandular portions of the grafts were granular and that these cells could be grouped into three general categories based on their secretory granule morphology. The sizes of the secretory granules ranged from 150‐550 nm in diameter. Clear examples of exocytosis of the granules were evident in grafts of both 12‐ and 15‐day PA, usually in areas of the graft that were more vascularized. In some cells exocytosis was extensive. Agranular cells in the graft parenchyma included follicular and undifferentiated cells.The results of this investigation suggest that kidney capsule grafts may prove useful in elucidating the factors that influe

ISSN:0003-276X    

DOI:10.1002/ar.1091890202

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe fine structure of luteal tissue from sheep and goats at the mid‐stage of the estrous cycle and during pregnancy was examined. At the mid‐stage of the estrous cycle, when the corpus luteum of both species is secreting progesterone, the ultrastructure of the luteal cells is similar in that granule secretion is prevalent. In late pregnancy, the corpus luteum of the sheep produces very little progesterone and there is an absence of granule secretion. In the pregnant goat, the production of progesterone from the corpus luteum is high and there is plentiful evidence of granule formation and secret

ISSN:0003-276X    

DOI:10.1002/ar.1091890203

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe number and the size of different populations of nuclei were studied in skeletal muscles and in the diaphragm of male Wistar rats of 200‐250 g weight. Nuclei on cross‐sections were counted and classified by electron microscopy, their incidence was corrected for their different lengths, and the number of nuclei per mm3of muscle was determined by light microscopy. The total number of nuclei per mm3was 5 · 104in the superficial part of the anterior tibial muscle, it was 10 · 104in the soleus, and it was 15 · 104in the diaphragm. Half of the nuclei were localized inside muscle fibres. The incidence of satellite cell nuclei on cross sections was 4% of muscle nuclei in the anterior tibial muscle, and 8% in soleus and diaphragm. The number of satellite cells per mm3muscle were 900, 4,900, and 5,300 in these muscles.More than half of the satellite cells were closely associated with a capillary. In the anterior tibial muscle, and in 1‐μm sections no satellite cells could be identified by light microscopy. In the soleus muscle and in the diaphragm, satellite cells were more rich in cytoplasm and many were visible in the light m

ISSN:0003-276X    

DOI:10.1002/ar.1091890204

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

年代:1977

数据来源: WILEY

摘要:

AbstractPolymorphonuclear leukocytes (PMN's) incubated three to eight minutes at 37°C in medium containing 1 × 10−6M of the ionophore antibiotic A23187 released their cytoplasmic granules into the extracellular medium. Transmission electron microscopy of treated cells showed microfilament bundles extending between adjacent granules within the cytoplasm and between granules and the plasma membrane. Tiny dense projections (beads) 8‐12 nm in diameter were observed along segments of the cytoplasmic surface of the plasma membrane with a periodicity of 20–30 nm. These beads were observed on the plasma membrane only in the vicinity of intra‐ or extracytoplasmic granules. The structural relationships of the beads with the plasma membrane micro‐filaments suggest they play a role in the process of ionophore‐induced granule release from polymorphonucle

ISSN:0003-276X    

DOI:10.1002/ar.1091890205

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

年代:1977

数据来源: WILEY

摘要:

AbstractPresumptive olfactory mucosa was excised from the heads of rat fetuses in the eleventh and twelfth days of gestation and explanted in organ cultures. At the time of explantation, the presumptive olfactory cells were recognizable by their long narrow apical processes and basally located nuclei. However at this stage they were in an early phase of differentiation as indicated by the large numbers of free ribosomes and virtual absence of microtubules and cilia in the apical cytoplasm. After three to eight days in culture, there was a progressive increase in the total number of cells in the epithelium. Differentiation in olfactory receptor cells was detectable by the appearance in the apical processes of axially oriented microtubules and centrioles or basal bodies. Some of which generated cilia. At their basal ends, the cytoplasm narrowed into axons and bundles of these axons, arranged in the unique manner of olfactory nerve axons, entered the connective tissue. Olfactory receptor cells, as defined by morphological criteria, differentiated under suitable organ culture conditions in the absence of any tissue from the central nervous system.

ISSN:0003-276X    

DOI:10.1002/ar.1091890206

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

年代:1977

数据来源: WILEY

摘要:

AbstractA method is presented by which fresh anatomical material may be preserved in a dry state while maintaining joint function and motion. This method could be likened to the tanning of the tendons and ligaments directly on the bones. Mastery of this technique has allowed the preservation of not only the tendinoskeletal system, but also the nervous, vascular, and endotracheal systems as well. While some skill in dissection is necessary, a large amount of the dissection can be done by chemical methods. The actual processing of the specimen is easily done with materials that are readily available. When finished, the specimen is dry, flexible, essentially odorless, and extremely durable. This method can be utilized for material ranging from simple osseous specimens to highly sophisticated dissections. These specimens have been found to be of exceptional advantage in teaching by demonstrating function as well as spatial relationships.

ISSN:0003-276X    

DOI:10.1002/ar.1091890207

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

年代:1977

数据来源: WILEY

摘要:

AbstractThis paper provides a description of the intercellular junctions in the rat testis, as observed using the freeze fracture technique. These intercellular junctions were categorized into four general types: Sertoli cell tight junctions, myoid cell tight junctions, gap junctions, and “heterogeneous junctions.” The Sertoli cell tight junctions had a mean depth of 3.1 μm in the basal to apical direction, and contained 25 to 50 (average: 36) parallel rows of particulate sealing elements. The myoid cell tight junction was neither continuous nor extensive, but focal in nature. Interestingly the sealing elements of this junction, like those of the Sertoli cell tight junction, were quite particulate in nature. Typical gap junctions were observed between Sertoli cells, where they were intercalated between the parallel rows of the Sertoli cell tight junction. The most interesting observation was the identification of gap junction‐like structures, in various stages of formation, on germ cell membrane fracture faces, both in the basal and adluminal compartments. Lastly, the unusual “heterogeneous junction” was observed on large membrane fracture faces in close proximity to cells in the adluminal compartment, presumably between Sertoli cells. These junctions appeared to consist of both tight and gap junctio

ISSN:0003-276X    

DOI:10.1002/ar.1091890208

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe ilioinguinal nerve was dissected in 196 adult human cadavers. A normal pattern of distribution, consistent with modern textual descriptions, was defied in 60% of in guinal regions. In 35% of the inguinal regions a previously undescribed aberrant course for the cutaneous component of the ilioinguinal nerve was observed in which it is incorporated within the genitofemoral nerve, entered the inguinal canal at the deep inguinal ring, coursed within the cremasteric layer and emerged into the subcutaneous tissue at the superficial inguinal ring on the dorsal side of the spermatic cord or the round ligament of the uterus. The cutaneous component of the ilioinguinal nerve is most frequently found on the ventral surface of the spermatic cord or round ligament during inguinal hernia operations thus an unrecognized aberrant course of this nerve within the spermatic cord is particularly susceptible to accidental trauma.

ISSN:0003-276X    

DOI:10.1002/ar.1091890209

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe ultrastructure or sarcoplasmic reticulum (SR) was studied in the conducting fibers of the dog heart. A dense network of sarcoplasmic tubules occurred in well preserved cytoplasmic areas. Some of the tubules extended into large sacs filled with finely filamentous material. The sacs often appeared in subsarcolemmal apposition connected to the sarcolemma by electron dense projections. The flattened cisternae of SR occurred beneath the sarcolem‐ma in the myofibrillar region of the cell. Long flattened cisternae only partially apposed to the sarcolemma were quite common in one specimen. Sarcoplasmic reticulum was continuous throughout the interfibrillar spaces surrounding each myofibril. At the level of the Z‐line the SR formed a quasi tubular flattened structure surrounding the Z‐line and closely adhering

ISSN:0003-276X    

DOI:10.1002/ar.1091890210

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe object of the present study was to examine ovarian oocytes of the sciuromorph rodent.Thomomys townsendii, to determine if they contained cytoplasmic inclusions similar to those reported in myomorph rodents. Our observations indicated the presence of cytoplasmic lamellar inclusions of oocytes of primary, secondary and large vesicular follicles ofThomomys.Small primary oocytes contained numerous cytoplasmic lamellae which appeared as spirals or concentric rings in cross‐section. Longitudinal sections suggested the inclusions were arranged as concentric cylindrical sheets of material. Secondary and vesicular oocytes had morphologically similar inclusions, but, in addition, often had a tubular element of the endoplasmic reticulum associated with the core of the lamellae. Tangential sections through the lamellae revealed a crystalline substructure, regardless of the age of the oocyte. Our results indicate that cytoplasmic lamellar inclusions are not restricted to myomorph rodents, but may well be present in other species. The lamellar inclusions are three‐dimensionally most similar in structure to those described in the hamster, but several fine structural differences exist even between these species.Thomomysis the only species to date in which a close topographical association develops between the lamellar inclusions and elements of the endoplasmic reticulum. Since the lamellae‐endoplasmic reticulum association was not observed in the youngest oocytes examined, it is unlikely the endoplasmic reticulum is involved in synthesis of the lamellae, but it may, nonetheless, be metabolically related to the lam

ISSN:0003-276X    

DOI:10.1002/ar.1091890211

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

年代:1977

数据来源: WILEY