ISSN:0003-276X    

DOI:10.1002/ar.1091460302

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

年代:1963

数据来源: WILEY

摘要:

AbstractA histochemical and electron microscopic study of the liver in rats fed a diet containing excess amounts of copper was made to demonstrate the intrahepatic, intralobular and intracellular distribution of the metal.Histochemically copper was demonstrated first at the periphery of the hepatic lobuleand appeared throughout the lobule as the amount of metal increased. Within the hepaticcell copper was demonstrated in the pericanalicular cytoplasm. As the amount of metal in the liver increased occasional perinuclear caps or plaques were formed. Hematoxylin and eosin stained sections of livers with high copper content differed from normal by the presence of light brown pigment. Copper was demonstrated histochemically in the spleen and kidneys of copper fed animals as well as in the liver.Electron microscopic studies of the hepatic cells from copper fed rats revealed numerous irregular dense bodies and pigment granules in the pericanalicular cytoplasm. The dense bodies were enclosed by a single membrane and contained granular material. The appearance of these pericanalicular bodies was associated with loss of histochemical acidphosphatase activity.

ISSN:0003-276X    

DOI:10.1002/ar.1091460303

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

年代:1963

数据来源: WILEY

摘要:

AbstractInternal remodelling of bone occurs continually during life in discrete foci throughout cortex and large trabeculae. It is defined as the process of replacement of primaryappositional bone with Haversian bone occurring within the periosteal‐endosteal envelope. The foci are produced by osteoclastic resorption of preexisting bone and are subsequently filled in by successive waves of osteoblasts that deposit new matrix. In this study, measurements of the surface area of Howship's lacunae in rib diaphysealcortex are presented for 137 relatively normal individuals of both sexes and ranging from one month to 84 years of age. Undecalcified cross‐sections were prepared fresh from rib obtained at thoracotomy or post‐mortem. Measurements were performed with a calibrated Zeiss Integrating Eyepiece II. It was found that the values for this resorption index were highest in infancy and lowest in middle and early adult life. The maximum adult values were attained in the seventh decade. No differences were noted that could be accounted for by sex. Correlation of these data with an index of secondary bone formation in this same group of bones enabled the authors to conclude that the internal remodelling rate of rib cortex is highest in infancy, lowest in the fourth decade and attains a secondary peak in the seventh decade. The authors suggest that the phasing of the changes noted are due to some as yet unknown programming of the mesenchymal cell. Since no increases coincided with growth spurts during childhood and adolescence, they conclude that the process of internal remodelling may be under a completely different mechanism of control from that governing skeletal growth and matur

ISSN:0003-276X    

DOI:10.1002/ar.1091460304

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

年代:1963

数据来源: WILEY

摘要:

AbstractThe need for the replacement of pre‐existing osseous tissue due to various physiologic and pathophysiologic demands is fulfilled by the resorption‐formation processes of the skeleton. These processes can be broadly categorized into two phases: Internal remodelling or the replacement occurring within the periostealendosteal envelope, and growth remodelling or the remodelling occurring at the periosteal‐endosteal surfaces during growth. The authors reason that changes in the numbers of new osteons found in cortex with age would provide insights into the mechanism (s) governing the production of these centers of new bone formation.Undecalcified cross‐sections of human rib from 139 relatively normal subjectsranging from one month to 84 years of age were prepared by Frost's method and stained with 1% basic fuchsin. The total number of osteons containing active osteoidseams was determined. The surface area of each cross‐section was measured and the data converted to a unit of number of seams/mm2of cortex. The largestnumber of seams/mm2occurred in infancy, with a gradual decline until the fourth decade. This was followed by a subsequent rise with a secondary peak in the seventh decade. The differences in means of the fourth and seventh decade were significant at the 1% level. Similar changes were noted in specimens of clavicle in 34 of the study cases.It is felt that the data indicates a net suppressive effect by gonadal hormones on the process of internal remodelling of diaphyseal cortex. Since the numbers of seams present at any given instant are representative of previous events affecting differentiation of the mesenchymal cell, the data indicates that the mechanism(s) controlling this process in the internal remodelling of rib and clavicle cortex may be independent of the mechanism(s) controlling differentiation of mesenchymal cells in growth and maturation of the

ISSN:0003-276X    

DOI:10.1002/ar.1091460305

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

年代:1963

数据来源: WILEY

摘要:

AbstractFemale Long‐Evans rats, were given a purified PGA‐deficient diet containing 10 mg% of the antimetabolite, 9‐methyl‐PGA, from days 8 to 10 of gestation, followed by a PGA‐supplemented diet from day 10 to autopsy. Thisregimen resulted in 18% embryonic death by day 11, 65% by day 12, and 100% by day 13 of pregnancy.No morphological differences between PGA‐deficient and control embryos were observed at nine or nine and one‐half days but ten‐day embryos showed retardation of growth and development and decreased mitosis, especially in the neural epithelium. In 11‐day PGA‐deficient embryos the cranial portion of the neural tube was markedly retarded or anomalous. PGA‐deficient embryos still living on day 12 exhibited severely retarded or abnormal development of the cranial region with moderate retardation in other areas. The placentas of PGA‐deficient embryos were normal until the twelfth or thirteenth day when vacuolization and pyknosis of giant cells in the junctional zone occurred. These changes as well as placental involution through day 16 appeared morphologically identical with those observed in placentas of embryosdestroyed surgically on day 12. PGA‐deficiency appeared primarily to affect embryonic rath

ISSN:0003-276X    

DOI:10.1002/ar.1091460306

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

年代:1963

数据来源: WILEY

摘要:

AbstractIt is widely known that the substance histamine is a noxious agent released from cells when they are injured. At the outset these experiments were intended to show whetherhistamine, persumably released by newt limb amputation, might also promote beginning steps in regeneration. In addition, according to a new view of the physiology of histamine, its formation metabolically by the decarboxylation of histidine is an attribute of the rapid growth of many tissues. These experiments were mainly designed to interfere with histamine production and thereby disrupt the rapid growth of the limb regenerate.Semicarbazide has been used successfully in mammals to inhibit histidine decarboxylase and decrease the rate of histamine formation. In these experiments, semicarbazide was administered to stumps of amputated newt limbs by microinfusion for many hours at a time in efforts to decrease histamine formation and retard growth.When semicarbazide was infused into the limb only in preblastemal stages of regeneration, it seemed to have no effect on the course of regeneration. When it was infused directly into the early mesenchymatous blastema, however, it retarded the expansion and differentiation of the blastema. From present evidence, it appears that histamine production may not be concerned in the initiation of limb regeneration but is probably concerned in the phase of rapid blastemal enlargement, whose primary histological attribute is cellular mitosis.

ISSN:0003-276X    

DOI:10.1002/ar.1091460307

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

年代:1963

数据来源: WILEY

摘要:

AbstractA technique is described for mounting both small and large serial sections on Dupontleader film or pieces of Mylar‐D plastic sheeting. The blocks are processed in the usual fashion and embedded in paraffin or celloidin. Small sections are mounted serially on five‐foot strips of 35 mm film in a gelatine waterbath and allowed to dry. The film strip is placed on a Nikor developing reel, the paraffin dissolved, the tissue hydrated, and the staining carried out in the usual fashion. The sections are cleared and allowed to dry and then covered with Varathane which hardens in 24 hours. The film strips are stored on 35 mm spools. Large paraffin embedded sections are processed separately in a similar fashion, mounted on Mylar‐D sheets, and stored in a loose‐leaf notebook. When celloidin is used it must be removed before mounting. The sections can be studied microscopically by passing the film over the stage of a microscope in a sequential fashion. The advantages of the method are di

ISSN:0003-276X    

DOI:10.1002/ar.1091460308

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

年代:1963

数据来源: WILEY

摘要:

AbstractAn improved embalming fluid has been developed for anatomical use. Potassium pyrophosphate and magnesium chloride are used to decrease the rigidity associated with formalin fixation. Substitution of sodium pentachlorophenate for phenol improves color relationships and eliminates most of the unpleasant cadaver odor. It gives as much, or more, protection against bacteria and fungi. Sorbitol replaces glycerine as a humectant with less browning of tissues, and a wetting agent is incorporated to facilitate distributionand penetration of the fluid.Wet storage of cadavers is recommended, and a vat fluid is described for use with the new embalming formula.

ISSN:0003-276X    

DOI:10.1002/ar.1091460309

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

年代:1963

数据来源: WILEY

摘要:

AbstractSpontaneous intersexuality in an adult rat, thought to be genetically male, has beendescribed. Both male and female primordia developed concurrently and most components ofeach were retained with normal adult characteristics. Gonadal and hypophyseal hormones in this specimen stimulated ductal and lobulo‐alveolar proliferation simulating that of the mammary gland during lactatio

ISSN:0003-276X    

DOI:10.1002/ar.1091460310

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

年代:1963

数据来源: WILEY

摘要:

AbstractThe anterior mesenteric artery of two species of fowl, the turkey and chicken, is found to differ structurally from the basic pattern observed in other avian arteries and in mammalian arteries in general. This difference in structure lies in the fact that the avian anterior mesenteric artery contains two well‐developed muscular components: an inner circular, and an outer longitudinal, analogous to the arrangement of the muscularis externa of the intestinal wall. However, the evidence presented indicates that the outer longitudinal layer is part of the adventitia. The possible functional significance of this feature is discusse

ISSN:0003-276X    

DOI:10.1002/ar.1091460311

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

年代:1963

数据来源: WILEY