摘要:

AbstractThree‐hour urine specimens were collected over a period of 27 hours from 11 healthy adult male subjects. Each specimen was analyzed for Na, K, Ca, Mg, and Zn using atomic absorption spectrophotometry. Each sample was also dialyzed, pH 7.35, and subsequently analyzed for Na, K, P, Ca, Mg, Zn, Fe, Pb, Al, Ni, Cu, Mo, Hg, Cr, Cd, and Mn using a multielemental argon‐plasma emission system. The data were evaluated on conventional time plots (chronograms) and as computer‐determined “cosinor” plots. A population circadian rhythm with a statistical significance was detected for total Na, K, Ca, and Mg, and for nondialyzable Na, K, P, Ca, Zn, and Mo. For almost every element studied the increase from lowest to highest 3‐hour group mean along the 24‐hour time scale was more than 100%. The 24‐hour excretion of Na, K, Ca, Mg, and Zn appeared in good agreement with the so‐called “normals.” The nondialyzable levels of Fe, Pb, Al, Ni, Cu, Mo, Hg, Cr, Cd, and Mn were similar to the total urinary excretions repor

ISSN:0002-9106    

DOI:10.1002/aja.1001660202

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe secretory cells of the oviductal epithelium in the pig‐tailed monkey,Macaca nemestrina, have been studied by light and electron microscopy. Changes during the menstrual cycle and after ovariectomy, with and without subsequent estrogen treatment, have been documented. During the early follicular phase the epithelium is recovering from deciliation and secretory cell atrophy that occur in the late luteal phase. A few fimbrial and a moderate number of ampullar and isthmic cells contain a few electron‐dense, homogeneous secretory granules in their apical cytoplasm. During the late preovulatory and early postovulatory periods, secretory cell structure varies considerably. Fimbrial cells typically display apical protrusions that contain no or a few small, mainly homogeneous, secretory granules. The cytoplasm is crowded with elements of the Golgi complex, with granular endoplasmic reticulum profiles often intimately associated with mitochondria, and with variable numbers of polysomes and glycogen granules. In ampullar and isthmic cells secretory granules are more abundant than in fimbrial cells, and electron‐lucent vacuoles appear. The granules are of two types: (1) those having an electron‐dense, homogeneous matrix, and (2) those possessing lamellar structures within moderately dense matrices. The lamellae of the second type course in parallel arrays separated by a distance of approximately 15.5 nm and exhibit a periodicity of approximately 11.3 nm. Possible transitional stages between the lamellar granules and the vacuoles containing lamellar fragments are observed. Secretion occurs by exocytosis. During the late luteal phase no fimbrial cells have secretory granules. In the ampulla many of the cells have poor development of the organelles involved in secretory activity and have few or no secretory granules. In others, a moderate number of secretory granules are present; in one animal, exocytosis is observed. In the untreated ovariectomized animal no secretory granules occur, and the organelle content is much less than in the cycling and the estrogen‐treated monkeys. In ovariectomized, estradiol‐treated monkeys, some areas of all three oviductal segments are well stimulated whereas others display little or no secreto

ISSN:0002-9106    

DOI:10.1002/aja.1001660203

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe purpose of the present investigation was to study the ultrastructure of the arcuate nucleus (ARC) and median eminence of hamsters on days 1–15 of the neonatal period. From days 1–6, the neurons of the ARC had large nuclei and a small amount of cytoplasm which contained polysomes, mitochondria, RER, lysosomes and Golgi complexes. From days 7–15 there was an increase in the amount of cytoplasm as well as more extensive Golgi complexes and RER. Astrocytes were the predominant glial component in both the ARC and median eminence. Astrocytic processes were in juxtaposition to unmyelinated axons, dendrites, and synapses. Axodendritic and axosomatic synapses containing clear vesicles were observed in the neuropil on day 1. There was an increase in the number of dense‐core vesicles in the axonal endings beginning on day 4.Concomitantly, there were increasing numbers of clear and dense‐core vesicles (64–70 nm) in terminals of the external layer of the median eminence, whereas larger dense‐core vesicles (105–140 nm) were distinguishable by day 10 immediately dorsal to the external layer. The capillaries of the median eminence were composed of nonfenestrated endothelium from days 1–9. Fenestrae began to appear about day 10. Ependymal cells lining the third ventricle had pinocytotic vesicles, microvilli, and bleb‐like protrusions on their apical surfaces. Ependymal processes were adjacent to nerve processes in the neuropil of the ARC and in the external layer of the median eminence, where they contacted the perivascular space.Two types of supraependymal cells were seen in animals throughout the neonatal period. One resembled a neuron which sent processes along the ependymal surface and often between cells. The second type was similar to a macrophage. The results of this study demonstrate the maturation of the neural elements in the ARC/median eminence area of t

ISSN:0002-9106    

DOI:10.1002/aja.1001660204

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

年代:1983

数据来源: WILEY

摘要:

AbstractOur radioimmunoassay data reveal that ovariectomy for either one or two months resulted in a significant decrease in the GnRH content of the mouse basal hypothalamus, while in mice ovariectomized for two weeks the GnRH levels did not differ significantly from controls. Parallel immunocytochemical analyses gave similar results. Tissue sections from specific regions of the median eminence in intact and ovariectomized mice were immunolabeled for GnRH with the peroxidase‐antiperoxidase procedure of Sternberger. Differences in area and average unit density of the reaction product were measured with a Quantiment 720 image analyzer. At two weeks after ovariectomy, a majority of matched sections from intact and ovariectomized animals, taken in each sampled region of the median eminence, showed no visually apparent difference in GnRH immunoreactivity. Quantitative image analysis of these preparations revealed no statistically significant difference in either the area of neural tissue covered by deposit or the average unit density of this material in any given region. In contrast, in mice ovariectomized for either one or two months, immunolabeled GnRH was decreased throughout the cephalo‐caudal extent of the median eminence. In each region, a reduction in reaction deposit was observed over most of the area in which GnRH is localized, especially in the medial aspects of this distribution. Image analysis of these preparations revealed a significant reduction of both specimen area immunolabeled for GnRH and the average unit density of reaction product in each region of the median eminence. While the decrease in density was uniform throughout the median eminence, the greatest reduction in area covered by deposit occurred in the infundibular region.The demonstration of a decrease in basal hypothalamic GnRH in the chronically ovariectomized mouse suggests that GnRH neurosecretion is increased in response to the absence of the ovaries and supports the premise that tonic secretion of this neurohormone, in the mouse, may be subject to regulation by the gonads. At two weeks after ovariectomy, it is possible that changes in GnRH secretion occur without a concomitant alteration in hypothalamic hormone content. In addition, the quantitative immunocytochemical data suggest that GnRH neurons responsive to ovariectomy terminate throughout the rostro‐caudal extent of the mouse median eminence, especially in the medial sites of localization. A proportionally greater number of these endings appear to be present within the infundibular region of the median eminence, relative to the other regions sa

ISSN:0002-9106    

DOI:10.1002/aja.1001660205

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe structural configuration of passive and contracted sarcomeres from frog sartorius muscle was determined for sarcomere lengths between 1.4 and 3.07 μm. Sarcomeres fixed with glutaraldehyde, without detectable contractile activity, were invariably rectangular in shape in longitudinal section regardless of sarcomere length. The structure of sarcomeres excited by osmium tetroxide and contracted depended upon sarcomere length. For lengths greater than 1.6 μm, longitudinally sectioned sarcomeres were convexoconvex (or barrel‐shaped). At 1.6 μm, contracted sarcomeres were invariably rectangular in shape. Below 1.6 μm, sarcomeres were compressed and appeared concavoconcave. The results of this study provide models for isovolumetrically contracted sarcomeres which differ significantly from those previously rep

ISSN:0002-9106    

DOI:10.1002/aja.1001660206

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

年代:1983

数据来源: WILEY

摘要:

AbstractEight condyles of four growing monkeys(Macaca fascicularis)of estimated ages between 1.6 and 3.6 years (minimum and maximum) were analyzed using radioautographic, histometric, and stereologic techniques. The aim of the study was to examine the relationship between intracondylar variations in structure and growth activities. The animals received3H‐proline (1 mCi/kg body weight) and3H‐thymidine (0.5 mCi/kg body weight) 24 and 3 hours, respectively, prior to sacrifice. The perichondral and chondral layers of the condylar articular covering as well as the subchondral zone of erosion were examined at different sampling sites distributed systematically in the anteroposterior and lateromedial dimension of the articulating surface. Intracondylar variations observed with respect to morphometric and radioautographic parameters suggest the following biologic mechanisms contributing to mandibular growth in a superior‐posterior direction. Greater mitotic activity at the central and posterior sites of the condylar perichondrium generates a population of progenitor cells that is larger in these than in other regions. On the other hand, the rate of differentiation of these progenitor cells into chondroblasts and chondrocytes, i.e., the “migration” into and through the chondral layers of the articulating covering, seems to be enhanced in the same superior and posterior areas. Additionally, while “migrating” faster, these cartilage cells become larger and produce greater amounts of extracellular matrix than those in the anterior parts of the condyle. Finally, enhanced resorptive activities in the superior and posterior regions of the subchondral zone of erosion provide an increased “loss” of degenerated chondrocytes, thereby establishing the basis for a cartilaginous drift in the superior‐

ISSN:0002-9106    

DOI:10.1002/aja.1001660207

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

年代:1983

数据来源: WILEY

ISSN:0002-9106    

DOI:10.1002/aja.1001660201

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

年代:1983

数据来源: WILEY