摘要:

AbstractVentricular myocardium from several adult specimens of hummingbirds (Eupetomena macroura macroura) were subjected to study by electrocardiography and by light and electron microscopy under normal and experimental conditions as provided by injection of 2,4‐dinitrophenol (DNP) and ether anesthesia. The birds were captured in Brazil, and were studied because of their high heart rates 428/460 minute on the average, seeking correlations of structure and function under normal conditions as well as after pharmacological stimuli. Under normal conditions, the hummingbird showed a highly developed sarcoplasmic reticulum, many gigantic mitochondrial with numerous tightly packed parallel mitochondrial cristae and tubules, and few small, dark bodies. The amount of sarcosomes is approximately equivalent to that of myofibrils. As seen in longitudinal sections of muscle fibers, often the junctions between successive mitochondria and both indentations of mitochondria and of the nuclear envelope occurred at the level of the Z bands. This gave the impression that contraction of the myofibrils shortened the nucleus and caused it to wrinkle. Most mitochondrial bulged at their middle as if they had been compressed between successive Z bands, suggesting a more resistant area at the level of these bands than in the rest of the myofibril. Almost no glycogen granules were found, probably because the high metabolic rate of the heart did not allow free storage of such carbohydrates.The administration of DNP was responsible for changes in the ECG (tachycardia and other alterations) and in the structure of the myocardium: large dilations in the sarcoplasmic reticulum and the appearance of small spaces in the mitochondri

ISSN:0003-276X    

DOI:10.1002/ar.1091590402

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

年代:1967

数据来源: WILEY

摘要:

AbstractSprague‐Dawley rats, which are not susceptible to the teratogenic effects of adrenalectomy, adrenal corticoids, and corticotropin noted in other species, were subjected to amniocentesis and to amniocentesis plus adrenalectomy.Amniocentesis was shown to be teratogenic when performed at any time between the fourteenth and eighteenth gestational days inclusive, but no malformations occurred either in control fetuses or when amniocentesis was performed on the thirteenth day of gestation. Fetal resorptions were increased following single amniocentesis on any gestational day from the thirteenth to the eighteenth inclusive. The predominant defects induced were cleft palate and limb deformity. Cleft palate occurred only after amniocentesis on the fourteenth, fifteenth, or sixteenth days of gestation, principally on the fifteenth day. However, limb deformity, consisting primarily of malrotation, syndactyly, and varying degrees of agenesis, occurred following single amniocentesis on any day of gestation from the fourteenth to the eighteenth inclusive, but principally on the fifteenth day. Adrenalectomy did not alter significantly either the nature or the incidence of the anomalies induced by amniocentesis.The data indicate that amniocentesis is teratogenic in the rat, and that the adrenal glands are neither essential for, nor do they exert any detectable influence upon the induction of those malformation

ISSN:0003-276X    

DOI:10.1002/ar.1091590403

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

年代:1967

数据来源: WILEY

摘要:

AbstractMeasurements of volume of the anterior pituitary and diameter of pituitary cells and differential counts of acidophilic and basophilic cells were made under normal or experimental condition of bilateral or unilateral adrenalectomy or bilateral thyroidectomy in late fetal and newborn rats. The pituitary volume showed a consistent rise from the twentieth day of pregnancy to the third day after birth, but not as rapidly relatively as did body weight. Just after birth, the cell diameter declined. Acidophilic and basophilic cells increased in per cent and stained more intensely.In fetuses, bilateral adrenalectomy caused an increase in both the “pituitary volume/body weight” ratio and the cell diameter. Unilateral adrenalectomy caused an increase in the cell diameter. Thyroidectomy showed an increase in both the cell diameter and the per cent of basophilic cells which were partially degranulated.In newborns, bilateral adrenalectomy caused the death of all operated rats. Unilateral adrenalectomy caused no significant change in all categories observed. Thyroidectomy showed an increase in per cent of basophilic cells, but not to the extent observed in fetuses. The basophilic cells were somewhat degranulated.The observations support the views that in the rat the pituitary‐adrenal and pituitary‐thyroid systems begin to function before birth and that the functioning of both systems is slightly reduced just afte

ISSN:0003-276X    

DOI:10.1002/ar.1091590404

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

年代:1967

数据来源: WILEY

摘要:

AbstractSubstitution of flavianic acid (50mM) or of a stoichiometric mixture of naphthol yellow S and hydrochloric acid, in place of picric acid in Van Gieson type mixtures gives deeper yellow colors to cytoplasm, muscle and erythrocytes. Higher concentrations of acid fuchsin can be used with consequent greater density of collagen fiber staining and improved contrast.The familiar weakening of hematoxylin nuclear stains by exposure to Van Gieson mixtures can be largely avoided by inclusion of 0.1Mferric chloride in the Van Gieson mixture. Alum hematoxylin can then be used in place of the unstable iron hematoxylin solutions, and the iron hematoxylin effect is attained by the iron postmordanting in the Van Gieson bath. A ten minute prestain in an alum hematoxylin containing 0.5% hematoxylin is adequate but density can be enhanced by longer staining or by staining at higher temperature; 5–10 min at 60°C is suggested. The iron containing flavianic or picric acid Van Gieson staining baths should be restricted to three minutes; longer exposures gradually weaken nuclear staining.Substitution of 0.1Mcopper sulfate for the iron in the Van Gieson bath also yields dark gray to black nuclei. Aluminum chloride (0.1M) has an effect similar to the control hydrochloric acid, while the chromium ion seems quite inferior, even to the control HCl mixture.A ferrous sulfate hematoxylin ripened overnight with a small amount of ferric chloride gives excellent progressive nuclear staining, adequate in 2–5 minutes, and not excessive in 30 minutes. The solution gradually deteriorates in 6–8

ISSN:0003-276X    

DOI:10.1002/ar.1091590405

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

年代:1967

数据来源: WILEY

摘要:

AbstractThe superior vena cava and adjacent right atrium containing the sinoatrial node in each of five human hearts was studied histologically in serial section. The tissue block of a 41 year old man was reconstructed in four colors to provide a three‐dimensional model of the sinoatrial node, atrial relations, blood supply and nodal configuration. The resulting model demonstrated the curved course of the compact sinoatrial node and the mural relations of its tapered superior and inferior ends.Microscopic measurements of the boundaries of the five human nodes yielded an epicardial to endocardial mean thickness in the compact body of the node of 1.6 mm, that of the lower node was 0.6 mm. The mean length of the five nodes was 7.3 mm. Such microscopic delineation of the node is more accurate than gross measurements and indicates that the size of this vital mass of pacemaker tissue in man is smaller than the larger measurements usually given in the literature. Small strands of nodal muscle fibers follow longer or shorter courses before they become continuous with the larger more darkly stained atrial cardiac muscle fibers. We found no histologic evidence within the human node, or along its periphery, of continuity between the small nodal fibers and very large atrial fiber

ISSN:0003-276X    

DOI:10.1002/ar.1091590406

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

年代:1967

数据来源: WILEY

摘要:

AbstractThe effects of excess thyroxine, thiouracil and thyroidectomy upon the ependymal cells of the subcommissural organ, the choroid plexus and the wall of the caudal part of the third cerebral ventricle in the adult male albino rats were studied. A total of 203 rats were used. Thiouracil and thyroxine were administered orally, thyroidectomy was performed by means of radioiodine. Thiouracil was seen to diminish the ependymal nuclear volume especially in the subcommissural organ and in the wall of the third ventricle. Similar effects were observed by thyroidectomy, though the change was significant only in the ependyma covering the wall of the third ventricle. Excess thyroxine, again, increased nuclear volume of all ependymal cells studied. The changes could be observed over a period of 4–18 days. The signs of a return to normal after withdrawal of thyroxine and thiouracil were perceived after four days. Visual estimation revealed no clear change in aldehyde‐fuchsin‐positive “secretory material” in the subcommissural organ of any test group. The functional significance of the results is

ISSN:0003-276X    

DOI:10.1002/ar.1091590407

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

年代:1967

数据来源: WILEY

摘要:

AbstractParietal cells of the fundic region of the stomach in the golden hamster (Mesocricetus auratus) contain numerous electron‐dense bodies which have different morphologies. Granular dense bodies are the most common, with lamellar and crystalloid forms less frequent; angular dense bodies with bizarre profiles are seen rarely. In random counts on sections of identical thickness, profiles of electron dense bodies averaged five per cell section and as many as 20 to 30 per cell section are found occasionally. These structures bear a striking resemblance to lysosomes described by other workers. Electron microscopic studies were made of frozen sections of the stomach incubated in Gomori's substrate mixture. Results indicated a discrete localization of acid phosphatase reaction products within the dense bodies. Studies on glutaraldehyde fixed material without further fixation in osmium tetroxide demonstrate features not readily discernable with standard osmium fixatio

ISSN:0003-276X    

DOI:10.1002/ar.1091590408

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

年代:1967

数据来源: WILEY

摘要:

AbstractA method is described whereby serial sections are photographed through a microscope and printed on a clear acetate film. The pictures are mounted on Plexiglas rectangles and placed back to back. A solid stack of plates with the reconstructed structure visible inside, or a slide‐box arrangement of every other section may be produced. Variations of the technique are presented so that one can print high‐contrast or low‐contrast pictures, reconstruct simple or complex structures, and work more rapidly with less equipment. This is a simple, accurate, and rapid m

ISSN:0003-276X    

DOI:10.1002/ar.1091590409

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

年代:1967

数据来源: WILEY

摘要:

AbstractThe fine structure of the duodenal glands of Brunner in the rabbit has been examined. The glands, which are concentrated within the submucosa, are composed of tubules that open into the bases of the intestinal glands. Unlike most species, in the rabbit two distinct cell types are present within the tubules. Serous cells, which occur in small groups in the blind endings to the tubules, contain a concentration of ergastoplasm in the basal cytoplasm and the apical cytoplasm is occupied principally by discrete secretory droplets. Intercellular secretory canaliculi occur between opposed serous cells and between serous and mucous cells. The latter cells possess little ergastoplasm but exhibit an extensive development of the Golgi apparatus in the supranuclear region. Secretory droplets are pale and show a tendency to fuse into complexes. No intercellular canaliculi occur between mucous cells.The cytological features are discussed in relation to previous observations on duodenal glands of other species, where only mucous cells are present. It is apparent that there are species differences with regard to mucous cells. These structural differences may reflect physiological and biochemical differences in the glands. The significance of the presence of serous cells in rabbit duodenal glands is unknown.

ISSN:0003-276X    

DOI:10.1002/ar.1091590410

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

年代:1967

数据来源: WILEY

摘要:

AbstractThe population dynamics of the jejunal epithelium of mice maintained on a semi‐synthetic diet deficient in the essential fatty acids (EFA) has been investigated. Colchicine was employed to collect mitotic figures for the determination of mitotic indices. Twenty‐five crypts in longitudinal section were counted per animal and the mean mitotic index computed as the number of mitoses per total number of crypt cells. EFA‐deficient animals had a mean mitotic index of 36.56 as compared with 26.51 and 16.74 for the linoleic acid‐supplemented and chow‐fed control animals, respectively. Counts of the number of epithelial cells on one side of a villus and crypt indicated that the height of the villi, but not the crypts, of the EFA‐deficient animals was significantly lower than either control group. In the EFA‐deficient animals the mean percentage of villi having extrusion zones exceeded that of both control groups. Radioautography demonstrated that 36 hours after injection of tritiated thymidine the majority of villi in the EFA‐deficient animals were labeled at their tips, whereas in control samples label was restricted to the lower one‐half to three‐fourths of the villus. Thus, EFA‐deficiency induces increased rates of mitosis, migration and sloughing, resulting in alterations in

ISSN:0003-276X    

DOI:10.1002/ar.1091590411

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

年代:1967

数据来源: WILEY