STRUCTURE AND DEVELOPMENT OF THE ADRENAL GLAND OF GALLUS DOMESTICUS

1965 ◽  
Vol 43 (6) ◽  
pp. 1021-1031 ◽  
Author(s):  
Saraswati Sivaram
Keyword(s):  
Golgi Apparatus ◽  
Adrenal Gland ◽  
Central Zone ◽  
Peripheral Zone ◽  
Gallus Domesticus ◽  
Histochemical Investigation ◽  
Embryonic Life ◽  
Mesodermal Origin ◽  
Migration Of Cells ◽  
Golgi Zone

The histology of the developing chick adrenal gland has been studied as a preliminary to a detailed histochemical investigation. Certain cytological observations pertaining to the Golgi apparatus and mitochondria in the cells of the gland have been made. The chromaffin component, which originates from the neural crest cells of the embryo, forms irregular islets dispersed among the cortical cords and is interconnected by strands and processes of the cells. The cortical component, which is of mesodermal origin, is organized into regular solid cylindrical cords. There appears to be a migration of cells from the periphery to the center of the cortex. The gland is richly permeated by blood sinuses and capillaries. From the last quarter of the incubation period, there is an indication of zonation in the cortex into a somewhat narrow peripheral zone and a larger central zone. The cells of the former exhibit a greater abundance of mitochondria and a smaller Golgi zone than do those of the latter. The cortex occupies a greater percent volume during embryonic life, while the medulla occupies a greater percent volume in later stages.

Three-Dimensional Analysis of Vestibular Efferent Neurons Innervating Semicircular Canals of the Gerbil

1997 ◽  
Vol 78 (6) ◽  
pp. 3234-3248 ◽  
Author(s):  
I. M. Purcell ◽  
A. A. Perachio
Keyword(s):  
Basement Membrane ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Central Zone ◽  
Semicircular Canals ◽  
Peripheral Zone ◽  
Longitudinal Axis ◽  
Open Loop ◽  
Response Dynamics ◽  
Efferent Neurons

Purcell, I. M. and A. A. Perachio. Three-dimensional analysis of vestibular efferent neurons innervating semicircular canals of the gerbil. J. Neurophysiol. 78: 3234–3248, 1997. Anterograde labeling techniques were used to examine peripheral innervation patterns of vestibular efferent neurons in the crista ampullares of the gerbil. Vestibular efferent neurons were labeled by extracellular injections of biocytin or biotinylated dextran amine into the contralateral or ipsilateral dorsal subgroup of efferent cell bodies (group e) located dorsolateral to the facial nerve genu. Anterogradely labeled efferent terminal field varicosities consist mainly of boutons en passant with fewer of the terminal type. The bouton swellings are located predominately in apposition to the basolateral borders of the afferent calyces and type II hair cells, but several boutons were identified close to the hair cell apical border on both types. Three-dimensional reconstruction and morphological analysis of the terminal fields from these cells located in the sensory neuroepithelium of the anterior, horizontal, and posterior cristae were performed. We show that efferent neurons densely innervate each end organ in widespread terminal fields. Subepithelial bifurcations of parent axons were minimal, with extensive collateralization occurring after the axons penetrated the basement membrane of the neuroepithelium. Axonal branching ranged between the 6th and 27th orders and terminal field collecting area far exceeds that of the peripheral terminals of primary afferent neurons. The terminal fields of the efferent neurons display three morphologically heterogeneous types: central, peripheral, and planum. All cell types possess terminal fields displaying a high degree of anisotropy with orientations typically parallel to or within ±45° of the longitudinal axis if the crista. Terminal fields of the central and planum zones predominately project medially toward the transverse axis from the more laterally located penetration of the basement membrane by the parent axon. Peripheral zone terminal fields extend predominately toward the planum semilunatum. The innervation areas of efferent terminal fields display a trend from smallest to largest for the central, peripheral, and planum types, respectively. Neurons that innervate the central zone of the crista do not extend into the peripheral or planum regions. Conversely, those neurons with terminal fields in the peripheral or planum regions do not innervate the central zone of the sensory neuroepithelium. The central zone of the crista is innervated preferentially by efferent neurons with cell bodies located in the ipsilateral group e. The peripheral and planum zones of the crista are innervated preferentially by efferent neurons with cell bodies located in the contralateral group e. A model incorporating our anatomic observations is presented describing an ipsilateral closed-loop feedback between ipsilateral efferent neurons and the periphery and an open-loop feed-forward innervation from contralateral efferent neurons. A possible role for the vestibular efferent neurons in the modulation of semicircular canal afferent response dynamics is proposed.

Sensorimotor Integration at the Dorsal Column Nuclei

Physiology ◽  
1999 ◽  
Vol 14 (6) ◽  
pp. 231-237
Author(s):  
Jorge Mariño ◽  
Luis Martinez ◽  
Antonio Canedo
Keyword(s):  
Sensorimotor Integration ◽  
Receptive Fields ◽  
Central Zone ◽  
Spatial Localization ◽  
Peripheral Zone ◽  
Dorsal Column ◽  
Primary Afferents ◽  
Zone Of Inhibition ◽  
Dorsal Column Nuclei ◽  
Recurrent Collaterals

Interaction among primary afferents, corticofugal fibers, and intrinsic elements allows for sensorimotor integration at the dorsal column nuclei. The interneurons permit the spatial localization, the recurrent collaterals synchronize the activity of projecting cells with overlapping receptive fields, and the corticofugal fibers induce a central zone of activity surrounded by a peripheral zone of inhibition.

scholarly journals Computed Tomography Perfusion, Magnetic Resonance Imaging, and Histopathological Findings After Laparoscopic Renal Cryoablation: An In Vivo Pig Model

2016 ◽  
Vol 16 (4) ◽  
pp. 406-413 ◽  
Author(s):  
Tommy Kjærgaard Nielsen ◽  
Øyvind Østraat ◽  
Ole Graumann ◽  
Bodil Ginnerup Pedersen ◽  
Gratien Andersen ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Central Zone ◽  
Peripheral Zone ◽  
Scar Tissue ◽  
Resonance Imaging ◽  
Computed Tomography Perfusion ◽  
Laparoscopic Assisted

The present study investigates how computed tomography perfusion scans and magnetic resonance imaging correlates with the histopathological alterations in renal tissue after cryoablation. A total of 15 pigs were subjected to laparoscopic-assisted cryoablation on both kidneys. After intervention, each animal was randomized to a postoperative follow-up period of 1, 2, or 4 weeks, after which computed tomography perfusion and magnetic resonance imaging scans were performed. Immediately after imaging, open bilateral nephrectomy was performed allowing for histopathological examination of the cryolesions. On computed tomography perfusion and magnetic resonance imaging examinations, rim enhancement was observed in the transition zone of the cryolesion 1week after laparoscopic-assisted cryoablation. This rim enhancement was found to subside after 2 and 4 weeks of follow-up, which was consistent with the microscopic examinations revealing of fibrotic scar tissue formation in the peripheral zone of the cryolesion. On T2 magnetic resonance imaging sequences, a thin hypointense rim surrounded the cryolesion, separating it from the adjacent renal parenchyma. Microscopic examinations revealed hemorrhage and later hemosiderin located in the peripheral zone. No nodular or diffuse contrast enhancement was found in the central zone of the cryolesions at any follow-up stage on neither computed tomography perfusion nor magnetic resonance imaging. On microscopic examinations, the central zone was found to consist of coagulative necrosis 1 week after laparoscopic-assisted cryoablation, which was partially replaced by fibrotic scar tissue 4 weeks following laparoscopic-assisted cryoablation. Both computed tomography perfusion and magnetic resonance imaging found the renal collecting system to be involved at all 3 stages of follow-up, but on microscopic examination, the urothelium was found to be intact in all cases. In conclusion, cryoablation effectively destroyed renal parenchyma, leaving the urothelium intact. Both computed tomography perfusion and magnetic resonance imaging reflect the microscopic findings but with some differences, especially regarding the peripheral zone. Magnetic resonance imaging seems an attractive modality for early postoperative follow-up.

Further analytical and experimental studies on the shoot apex of Helianthus annuus: variable activity in the central zone

1979 ◽  
Vol 57 (8) ◽  
pp. 971-980 ◽  
Author(s):  
E. L. Davis ◽  
Patricia Rennie ◽  
Taylor A. Steeves
Keyword(s):  
Helianthus Annuus ◽  
Mitotic Activity ◽  
Shoot Apex ◽  
Experimental Studies ◽  
Central Zone ◽  
Peripheral Zone ◽  
Intact Plants ◽  
Cast Doubt ◽  
Young Leaves ◽  
Mitotic Frequency

The cytologically distinctive central zone of the vegetative shoot apex of Helianthus annuus L. cv. Peredovic has a mitotic frequency considerably lower than that of the surrounding peripheral zone in intact plants. Apices excised and grown in culture for 5 days before being supplied with [H3]thymidine reveal a correspondingly low level of DNA synthesis in the central zone when autoradiographed. In similarly cultured apices, mitotic activity in the central zone is less than that recorded for intact plants. Labelling immediately after excision of the apex indicates that the central zone cells are activated by the operation and quiescence returns during the following 5 days. This activation is confirmed by mitotic counts 2 days after excision. The removal of only two young leaves from the apical buds of otherwise intact plants results in a comparable stimulation of mitotic activity in the central zone. These observations cast doubt upon the significance of mitotic activity in living shoot apices when these have been exposed for observation by removal of leaves. They also raise questions about the validity of labelling techniques which involve the partial dissection of the shoot apex.

scholarly journals Mucus formation in goblet cells

1933 ◽  
Vol 113 (784) ◽  
pp. 459-463 ◽  
Keyword(s):  
Golgi Apparatus ◽  
Salivary Glands ◽  
Secretory Granules ◽  
Goblet Cells ◽  
Neutral Red ◽  
Basal Region ◽  
Mucous Cells ◽  
Cell Type ◽  
Golgi Network ◽  
Golgi Zone

The formation of mucus in goblet cells and its relation to the Golgi apparatus has been studied by various workers. Nassanow (1923) showed clearly that the mucin granules in the goblet cells of Triton originated in the Golgi apparatus, and so brought secretion in these cells into line with his theory of the bound secretion. More recently Clara (1926) has shown in the goblet cells of birds that the mucin first appears in the region next to the nucleus, between it and the gland lumen. Florey (1932, a, b ) has considered this more extensively in two recent papers, and for a number of mammals has shown that the mucin granules of goblet cells first form in the meshes of the Golgi network. In epithelial cells of the mouse vagina, undergoing conversion into mucous cells, he has found that the same process occurs. In a recent investigation of secretory formation in the salivary glands and pancreas it was found by the present author that in every cell type examined the young secretory granules first appeared in the basal region of the cell in relation to the mitochondria. Subsequent emigration occurred into the Golgi zone, where they underwent conversion into mature secretory granules. In the mucous cells of the salivary glands it was shown that these newly formed granules might be stained intravitam by Janus green or neutral red, and that in fixed preparations they stained selectively with acid fuchsin as described by Noll (1902), In the light of this work it appeared probable that while mucin formation might occur in the Golgi zone of the goblet cells as described by these authors, the origin of the granules might lie in the basal region of the cell.

Membrane Properties of Chick Semicircular Canal Hair Cells In Situ During Embryonic Development

2000 ◽  
Vol 83 (5) ◽  
pp. 2740-2756 ◽  
Author(s):  
S. Masetto ◽  
P. Perin ◽  
A. Malusà ◽  
G. Zucca ◽  
P. Valli
Keyword(s):  
Hair Cell ◽  
Hair Cells ◽  
Central Zone ◽  
Cell Voltage ◽  
Peripheral Zone ◽  
Membrane Properties ◽  
Voltage Response ◽  
Type I ◽  
Electrophysiological Properties ◽  
Different Types

The electrophysiological properties of developing vestibular hair cells have been investigated in a chick crista slice preparation, from embryonic day 10 ( E10) to E21 (when hatching would occur). Patch-clamp whole-cell experiments showed that different types of ion channels are sequentially expressed during development. An inward Ca2+ current and a slow outward rectifying K+current ( I K(V)) are acquired first, at or before E10, followed by a rapid transient K+current ( I K(A)) at E12, and by a small Ca-dependent K+ current ( I KCa) at E14. Hair cell maturation then proceeds with the expression of hyperpolarization-activated currents: a slow I h appears first, around E16, followed by the fast inward rectifier I K1around E19. From the time of its first appearance, I K(A) is preferentially expressed in peripheral ( zone 1) hair cells, whereas inward rectifying currents are preferentially expressed in intermediate ( zone 2) and central ( zone 3) hair cells. Each conductance conferred distinctive properties on hair cell voltage response. Starting from E15, some hair cells, preferentially located at the intermediate region, showed the amphora shape typical of type I hair cells. From E17 (a time when the afferent calyx is completed) these cells expressed I K, L, the signature current of mature type I hair cells. Close to hatching, hair cell complements and regional organization of ion currents appeared similar to those reported for the mature avian crista. By the progressive acquisition of different types of inward and outward rectifying currents, hair cell repolarization after both positive- and negative-current injections is greatly strengthened and speeded up.

Finite Element Simulation of Cyclic Channel Die Compression with Route A

2010 ◽  
Vol 44-47 ◽  
pp. 1300-1304
Author(s):  
Feng Jian Shi ◽  
Tao Xu ◽  
Sheng Lu ◽  
Lei Gang Wang
Keyword(s):  
Finite Element ◽  
Large Strain ◽  
Effective Strain ◽  
Central Zone ◽  
Peripheral Zone ◽  
Linear Increase ◽  
Rigid Plastic ◽  
Compression Load ◽  
Fine Grained ◽  
Two Stages

In this paper, effective strain and load were simulated by rigid-plastic finite element method (FEM) during cyclic channel die compression (CCDC) with route A, and the optical microstructure was observed. The results show that large strain can be accumulated in the material by CCDC. The load variation includes two stages, slowly linear increase and rapid increase. At the end of the CCDC, the compression load rises rapidly. Apart from the edges of the specimen, the effective strain is higher in the central region and lower at the surrounding region. The effective strain gradient increases with the number of compression. Grain refinement at the central zone is faster due to the strain inhomogeneity. But the peripheral zone is also refined with the number of CCDC. This illustrates CCDC is a promising method for producing bulk ultra-fine grained materials.

Location of local recurrence after MRI-guided partial prostate brachytherapy targeting only the peripheral zone: Implications for focal therapy.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 149-149 ◽  
Author(s):  
Konstantin Kovtun ◽  
Tobias Penzkofer ◽  
Neha Agrawal ◽  
Tina Kapur ◽  
Andriy Fedorov ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Local Recurrence ◽  
Central Zone ◽  
Peripheral Zone ◽  
Focal Therapy ◽  
Prostate Brachytherapy ◽  
Local Recurrences ◽  
Endorectal Coil ◽  
Mri Scans ◽  
Mri Guided

149 Background: Prostate cancer local recurrences usually occur at the same site as the dominant primary tumor in patients treated with radiation therapy to the whole gland. We characterized location of local recurrences in patients who were treated with MRI Guided Partial Brachytherapy in which only the peripheral zone was targeted. Methods: We retrospectively reviewed ten patients with initial cT1c, Gleason score 3+4 or less prostate cancer who developed biopsy proven local recurrences and had available imaging after MRI Guided Partial Brachytherapy targeting the peripheral zone from 1998 to 2006. All 10 patients had 1.5T endorectal coil MRI at diagnosis, performed primarily for staging and not for tumor localization, while at recurrence 8 had 3T endorectal coil MRI and 2 had 1.5T endorectal coil MRI. Scans consisted of at least T1 and T2 sequences. Two radiologists (C.T. and T.P.) blinded to clinical data reviewed diagnosis MRI scans together and quantified likelihood of tumor on a 1 to 5 scale in each section of an eight part prostate in both pre-treatment and recurrence scans. Local recurrence was judged to be in the same location as the baseline tumor if at least 50% of the tumor location overlapped. Results: Only 3 of 10 patients had local recurrences at the same location as the baseline tumor with a mean overlap of 64%. 7 of 10 patients had local recurrences at a different location with a mean overlap of 5%. 5 of 10 patients had recurrences in the central zone of the prostate which did not definitively show tumor on review of the initial 1.5T staging scan. Conclusions: After MRI-guided brachytherapy targeting only the peripheral zone in men initially staged with 1.5T MRI, 50% of the local recurrences occurred at the non-targeted central zone, raising the possibility that focal therapy directed only at the dominant tumor will result in increased out-of-field recurrences. Whether the superior ability of modern 3T multiparametric MRI to detect and precisely localize occult prostate cancer foci will reduce this risk is the subject of current study.

Does tumor location affect prostate cancer prognosis?

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 45-45 ◽  
Author(s):  
Jun Akatsuka ◽  
Go Kimura ◽  
Kotaro Obayashi ◽  
Masayuki Sano ◽  
Masato Yanagi ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Gland ◽  
Ejaculatory Duct ◽  
Prognostic Significance ◽  
Central Zone ◽  
Peripheral Zone ◽  
Recurrence Risk ◽  
Tumor Location ◽  
Cancer Prognosis ◽  
Prostate Cancer Prognosis

45 Background: Does tumor location affect prostate cancer prognosis? To clarify this question we conducted a retrospective study to characterize the incidence and prognostic significance of tumor location of prostate cancer. Methods: From 2000 to 2017, radical prostatectomy with no neoadjuvant therapy was performed in 916 cases in our hospital. Serial whole mount sections were reviewed to determine the incidence, clinicopathological features and prognostic significance of tumor location in the prostate gland. For the tumor location, we defined the subzones, which were made from subdivision of the McNeal’s zonal anatomy, are shown in Table 1 in detail. The peripheral zone (PZ) is composed of 8 subzones including A1, A2, A3 , M1, M2, M3, M4, M5. The transition zone (TZ) is composed of 5 subzones including T1, T2, T3, T4 and B1. The central zone (CZ) is composed of 3 subzones including M6, B2 and B3. Results: The median age was 67 and PSA was 8.6 ng/ml. The subzonal tumor incidence divided by all cases was the highest in A2, followed by M4, A1, M3, T2 in that order, while the lowest in B3, followed by M6, T4, T3, B1 in that order. The median follow-up time was 67 months. A 5-year PSA failure rate (5Y-PSAFR) was 23%. Among the subzones, the highest 5Y-PSAFR was seen in B3, followed by M6, B2, T4, A3, and the lowest was seen in M4, A2, T2, A1 in that order. A multivariate analysis for PSAF risk among subzones showed that B3 (HR 8.6, p <0.0001) and M6 (HR 3.3, p = 0.03) were the independent high risk subzones. Conclusions: We demonstrated that the cancer incidence and prognosis varies according to the location within the prostate gland. The B3 and M6 around the ejaculatory duct showed the lowest incidence, while these locations also had the highest recurrence risk. [Table: see text]

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