摘要:

AbstractAlthough a number of morphological studies have investigated the vascular system of the rat kidney, minimal data are available on the detailed anatomy of the efferent arterioles located throughout the cortex of the kidney. In the present study, the renal vascular system was filled with Microfil and the various efferent arteriole patterns were examined extensively. The efferent vessels of the entire cortex appear to form three major patterns which in turn divided the cortex into three separate regions: the outer, middle and inner cortex. The efferent arterioles of the outer cortex leave the glomerulus and run perpendicular to the kidney capsule. However, as the efferent arterioles ascend, they may show three variations in the way they branch: (1a) the efferent arteriole does not branch until directly beneath the capsule, (1b) the efferent vessel begins to divide into its major branches 100–200 μm below the surface of the kidney and (1c) the efferent vessel has only a short course before giving off many side branches. In the middle cortical area, the branches of the efferent arteriole run lateral to the glomerulus. However, the efferent arterioles of the inner cortex have a few branches which run lateral to the glomerulus while most of them descend into the medulla as vasa rectae. The unique morphological features of the efferent arterioles of the outer cortex are of particular interest in light of the functional data which suggests that the reabsorption of fluid by peritubular capillaries may indeed regulate the rate of net tubular sodium reabsorpti

ISSN:0003-276X    

DOI:10.1002/ar.1091870202

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

年代:1977

数据来源: WILEY

摘要:

AbstractGranular cell indices (GCI: Dunihue and Robertson, 1957) in kidneys of fetal rats one day after maternal nephrectomy or fetal unilateral nephrectomy on day 21 of gestation were determined by examining sections stained with Bowie's technique. Maternal nephrectomy induced an extreme increase of GCI in fetal kidneys with increased granularity of cells in the juxtaglomerular apparatus. Fetal unilateral nephrectomy did not cause any significant change.

ISSN:0003-276X    

DOI:10.1002/ar.1091870203

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe sublingual gland of the cat consists primarily of branched secretory tubules that open into an abbreviated duct system. The simple epithelium that composes the secretory tubules consists of an admixture of mucous and serous cells, with the former predominating. Some secretory tubules are capped by a serous demilune. Regardless of position, almost all serous cells have prominent basal folds and border on at least one intercellular canaliculus as well as on the tubule lumen. Serous cells possess an extensive array of irregular, distended cisternae of rough‐surfaced endoplasmic reticulum that frequently contain dense intracisternal granules. Serous granules are relatively few in number and rarely show evidence of substructure. Mucous cells, which lack basal folds, contain an apical mass of secretory material in the form of partially fused droplets. The duct system is somewhat less ordered than in most major salivary glands; secretory tubules empty into structures resembling intercalated ducts or may be in direct continuity with ducts intermediate in morphology between intercalated and excretory ducts. The absence of striated ducts noted in this study may be correlated with the high sodium content of cat sublingual saliva. The main excretory duct of the sublingual gland closely resembles that of the cat submandibular gland in terms of morphology, but exhibits little of the transport functions reported in the latter duc

ISSN:0003-276X    

DOI:10.1002/ar.1091870204

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

年代:1977

数据来源: WILEY

摘要:

AbstractIn 29 normal persons with complete dental arches, the muscular activity of the temporalis, masseter, medial pterygoid, anterior belly of the digastric, mylohyoid and geniohyoid muscles was studied electromyographically with bipolar fine wire electrodes during various mandibular movements – both resisted and unresisted. Action potentials were recorded on FM magnetic tape and each experiment was also videotaped. Temporalis muscle was active during centric closing of the jaw with either contact of the teeth, or against resistance; during free lateral movements to the ipsilateral side, either against resistance or occlusal contact; during incisor gum chewing, molar gum chewing on ipsilateral or contralateral sides, during normal mastication; and during forceful centric occlusion.Activity occurred in the masseter and medial pterygoid muscles during the following movements: closing the jaw slowly either without occlusal contact or with occlusal contact and against resistance; free lateral movement to contralateral side, either against resistance or with occlusal contact; protraction of the jaw either without occlusal contact or with occlusal contact; swallowing either saliva or water; incisor gum chewing with either the ipsilateral or contralateral molars; normal mastication; and during forceful centric occlusion.Activity occurred in the digastric, mylohyoid and geniohyoid muscles during the following movements; opening of the jaw either slowly or maximally against resistance; closing the jaw against resistance; free lateral movement to ipsilateral and contralateral sides, either against resistance or with occlusal contact; protraction against resistance of the jaw either without or with occlusal contact; swallowing saliva and water; and protraction of the tongue. They work in antagonism (reciprocally) during gum chewing and normal masticatio

ISSN:0003-276X    

DOI:10.1002/ar.1091870205

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

年代:1977

数据来源: WILEY

摘要:

AbstractReticular and collagenous fibers stain differently when subjected to ammoniacal silver reduction. A variety of tissues were subjected to such a “reticulin” technique and the association of reaction product with intercellular connective tissue elements was studied with the electron microscope. The reaction with reticular fibers was primarily associated with the interfibrillar matrix, and was globular in form having a wide variety of particle sizes. Conversely, in dermal collagen the unit fibrils were stained rather than the interfibrillar matrix. The precipitate was punctate in form and was associated with the cross striations of unit collagen fibrils. Large microfibrils also reacted positively with the stain, imparting a faint periodicity. Basement membranes were stained uniquely. The underlying plasmalemma and the lamina densa were heavily stained with silver while the lamina lucida was relatively unstained. The unit fibrils of the lamina reticularis stained in the same manner as dermal unit collagen while the ground substance remained unstained. This represents a clear distinction between the argentophilic characteristics of collagenous fibers, reticular fibers, and basement membra

ISSN:0003-276X    

DOI:10.1002/ar.1091870206

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

年代:1977

数据来源: WILEY

摘要:

AbstractMice fed a high cholesterol‐cholic acid diet for two to six months develop gallstones; these were studied by transmission electron microscopy after glutaraldehyde‐digitonin fixation. Examination of the contents of mouse gallbladders presents views of layered structures and surrounding amorphous material. We interpret these images of gallstones to suggest that they may arise by cohesion of material rich in cholesterol to form more ordered structures. Gallbladder contents of mice fed the diet for five to six months were found to contain occasional crystals and rectangular areas similar to those observed in thin sections of human gallstones (unpublished observations). Recent findings that human gallstones can be dissolved with chenodeoxycholic acid are discussed, with reference to their applicability to studies of gallstones in m

ISSN:0003-276X    

DOI:10.1002/ar.1091870207

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe differentiation of leukocytes in the bone marrow and blood of normal adult male rats was studied by electron microscopy and peroxidase cytochemistry. Tissue samples were fixed in glutaraldehyde, or paraformaldehyde‐glutaraldehyde, and incubated in a peroxidase medium containing 3,3′‐diaminobenzidine and H2O2at pH 7.6. Mature cells of blood were identified, and then the earlier stages of maturation in bone marrow were analyzed. In immature cells of four cell lines, neutrophils, monocytes, basophils, and eosinophils, peroxidase is synthesized and could be demonstrated in the rough endoplasmic reticulum (RER), Golgi complex, and in cytoplasmic granules. Later in maturation, reaction product for peroxidase could not be found in RER or Golgi complex, indicating that peroxidase synthesis had ceased. In two cell lines, neutrophils and monocytes, peroxidase‐negative granules were formed, and the mature cells contained two populations of cytochemically distinct granules. All granules of mature eosinophils were peroxidasepositive. In mature basophils, some granules were clearly peroxidase‐positive; others displayed variable density, making interpretation uncertain. Mast cells were never seen in blood, but were abundant in bone marrow; peroxidase was never found in their granules by either electron microscopic cytochemistry or a variety of light microscopic methods. Hence, these cells differ from basophils, not only in morphology but also in the enzyme content of their

ISSN:0003-276X    

DOI:10.1002/ar.1091870208

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

年代:1977

数据来源: WILEY

摘要:

AbstractAn experiment designed to study the effects of the copper IUD on the virgin rat uterus has revealed the presence of intracellular collagen fibrils in control uteri and in uteri that have contained a copper IUD for three months. The cells containing the collagen are found in the stroma in close proximity to the uterine epithelium. The collagen is found within membrane‐bound cytoplasmic vacuoles that vary in morphology. In some cases the fibrils are tightly packed and linear, with no other material evident in the vacuole. In other examples, the fibrils are randomly arranged and the vacuoles contain a punctate material which is characteristic of phagolysosomes. Finally, cytoplasmic vacuoles are seen which contain ill‐defined debris and poorly‐visualized structures that exhibit a periodicity, suggesting a terminal phase of fibril breakdown. All animals were sacrificed in metestrus, and the results indicate that intracellular collagen is present in the nulliparous rat uterus at this stage of the cycle. In addition, this phenomenon does not appear to be influenced by the presence of a copper IUD over a period of three m

ISSN:0003-276X    

DOI:10.1002/ar.1091870209

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

年代:1977

数据来源: WILEY

摘要:

AbstractElectronmicrographs of both the vermis and hemisphere of the cerebellum of the squirrel monkey (Saimiri sciureus) show numerous granule cell bodies partially or completely surrounded by myelin. The myelin is of the compact type and consists of 1 to 13 lamellae. In several cases of partially ensheathed cells the myelin is clearly derived from extensions of myelin sheaths that surround small caliber axons. Either all or only the outer lamellae surrounding the axon contribute to the extensions. In the first instance the myelin buckles at its mesaxon pole and the resulting doubled flap extends for a variable distance along the cell surface.

ISSN:0003-276X    

DOI:10.1002/ar.1091870210

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

年代:1977

数据来源: WILEY

摘要:

AbstractPieces of upper lip and lower jaw from 13‐day old mouse embryos grown in organ culture with excess vitamin A showed metaplastic changes in epidermis and hair follicles after 7 to 21 days. Changes were less marked in upper lip explants from 15‐day old embryos. Areas of keratinizing epidermis showed a much higher incidence of Alcian blue‐positive bodies when excess vitamin A was present. Histochemical tests with Alcian blue at critical electrolyte concentrations indicated moderately sulfated acidic mucosubstances in these bodies. Other patches of epidermis were transformed into stratified cuboidal epithelium producing PAS‐positive. Alcian blue‐negative, mucosubstances. The hair follicles, transformed by vitamin A into glands, developed three types of epithelium with apical granules, luminal borders and occasional goblet cells, all showing mucosubstances. Tests suggest that both metaplastic epidermis and glands secrete either neutral mucosubstances or non‐sulfated acidic mucosubstances. Another response to vitamin A was a rapid loss of glycogen, particularly in hair follicles and the epidermal basal layer. It was concluded that excess vitamin A alters not only the morphogenesis but also the distribution and synthesis of polysaccharides in deve

ISSN:0003-276X    

DOI:10.1002/ar.1091870211

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

年代:1977

数据来源: WILEY