scholarly journals Macrophages and Leydig Cells in Testicular Biopsies of Azoospermic Men

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Trpimir Goluža ◽  
Alexander Boscanin ◽  
Jessica Cvetko ◽  
Viviana Kozina ◽  
Marin Kosović ◽  
...  

A number of studies have indicated that testicular macrophages play an important role in regulating steroidogenesis of Leydig cells and maintain homeostasis within the testis. The current paper deals with macrophages (CD68 positive cells) and Leydig cells in patients with nonobstructive azoospermia (NOA). Methods employed included histological analysis on semi- and ultrathin sections, immunohistochemistry, morphometry, and hormone analysis in the blood serum. Histological analysis pointed out certain structural changes of macrophages and Leydig cells in NOA group of patients when compared to controls. In the testis interstitium, an increased presence of CD68 positive cells has been noted. Leydig cells in NOA patients displayed a kind of a mosaic picture across the same bioptic sample: both normal and damaged Leydig cells with pronounced vacuolisation and various intensity of expression of testosterone have been observed. Stereological analysis indicated a significant increase in volume density of both CD68 positive and vacuolated Leydig cells and a positive correlation between the volume densities of these cell types. The continuous gonadotropin overstimulation of Leydig cells, together with a negative paracrine action of macrophages, could result in the damage of steroidogenesis and deficit of testosteronein situ.

1989 ◽  
Vol 94 (1) ◽  
pp. 61-71
Author(s):  
B.K. Rasheed ◽  
E.C. Whisenant ◽  
R.D. Ghai ◽  
V.E. Papaioannou ◽  
Y.M. Bhatnagar

An H1 histone variant, H1a, has been isolated and purified from the mouse testis. Biochemical and amino acid analyses indicate its similarity with the rat testis H1a. Specific antibodies against the purified H1a have been generated in rabbits and used to study its tissue and species distribution using protein blotting procedures. We have also used the immunocytochemical technique to determine in situ distribution of H1a in spermatogenic cells and somatic tissues of the mouse. A non-random distribution of H1a has been noted in the nuclei of certain somatic cell types such as Sertoli cells, Leydig cells and neurons. By contrast, hepatocyte nuclei lacked detectable levels of H1a. In adult seminiferous tubules, the early primary spermatocyte nuclei displayed a greater level of immunoreactivity relative to other cell types. Developmental studies indicate its initial expression in the 7-day-old mouse testis concomitant with the appearance of intermediate and type B spermatogonia.


1993 ◽  
Vol 5 (5) ◽  
pp. 545 ◽  
Author(s):  
H Li ◽  
GP Risbridger ◽  
JA Clements

The presence of testicular pro-opiomelanocortin (POMC) mRNA and POMC-derived peptides has recently been demonstrated in purified preparations of interstitial macrophages and in Leydig cells of the adult rat testis by Northern blot analysis and immunocytochemistry. In the present study, in situ hybridization provided further evidence that the POMC gene is expressed by both purified interstitial macrophages and Leydig cells. The cellular localization of the POMC transcripts was similar for both cell types, silver grains being predominantly located in the cytoplasm. The specificity of the labelling was demonstrated by the lack of silver grains in the preparations pretreated with RNAase or hybridized with an insulin cDNA probe, a gene known not to be expressed in these cell types. An additional control was provided by hybridization with a sense POMC RNA probe, which gave a less intense signal when compared with the antisense RNA probe under the same experimental conditions. The results confirm POMC gene expression in both macrophages and Leydig cells in the adult rat testis.


1980 ◽  
Vol 42 (1) ◽  
pp. 305-321
Author(s):  
F. Puvion-Dutilleul ◽  
E. Puvion

Exposure of cultured CVI monkey kidney cells to a hypotonic medium containing a nonionic detergent induces a partial decondensation of nuclear components which can be studied advantageously in ultrathin sections. In addition to previously described 20–25 nm, DNA-containing chromatin fibres arrayed perpendicularly to the nuclear lamina, a new nuclear configuration was found which consists of abundant clusters of 6–7 nm fibrils. These ‘filamentous masses’ are the most heavily labelled component of the nucleus in autoradiographs after brief (2 min) exposure to [5-3H]uridine, and they are greatly diminished in number after treatment of the cells with a low dose of actinomycin D. Therefore, we interpret the filamentous masses to be nascent RNP and to represent the fibrillar regions of the nucleolus which have become decondensed into partially spread ‘Christmas-tree’-like figures detectable in situ in ultrathin sections. Similar structures occur in all cell types examined to date. This paper outlines the preparative procedure.


Author(s):  
K. Kovacs ◽  
E. Horvath ◽  
J. M. Bilbao ◽  
F. A. Laszlo ◽  
I. Domokos

Electrolytic lesions of the pituitary stalk in rats interrupt adenohypophysial blood flow and result in massive infarction of the anterior lobe. In order to obtain a deeper insight into the morphogenesis of tissue injury and to reveal the sequence of events, a fine structural investigation was undertaken on adenohypophyses of rats at various intervals following destruction of the pituitary stalk.The pituitary stalk was destroyed electrolytically, with a Horsley-Clarke apparatus on 27 male rats of the R-Amsterdam strain, weighing 180-200 g. Thirty minutes, 1,2,4,6 and 24 hours after surgery the animals were perfused with a glutaraldehyde-formalin solution. The skulls were then opened and the pituitary glands removed. The anterior lobes were fixed in glutaraldehyde-formalin solution, postfixed in osmium tetroxide and embedded in Durcupan. Ultrathin sections were stained with uranyl acetate and lead citrate and investigated with a Philips 300 electron microscope.


Author(s):  
Mohinder S. Jarial

The axolotl is a strictly aquatic salamander in which the larval external gills are retained throughout life. The external gills of the adult axolotl have been studied by light and electron microscopy for ultrastructural evidence of ionic transport. The thin epidermis of the gill filaments and gill stems is composed of 3 cell types: granular cells, the basal cells and a sparce population of intervening Leydig cells. The gill epidermis is devoid of muscles, and no mitotic figures were observed in any of its cells.The granular cells cover the gill surface as a continuous layer (Fig. 1, G) and contain secretory granules of different forms, located apically (Figs.1, 2, SG). Some granules are found intimately associated with the apical membrane while others fuse with it and release their contents onto the external surface (Fig. 3). The apical membranes of the granular cells exhibit microvilli which are covered by a PAS+ fuzzy coat, termed “glycocalyx” (Fig. 2, MV).


Author(s):  
Emma Puighermanal ◽  
Emmanuel Valjent

Addictive drugs trigger persistent synaptic and structural changes in the neuronal reward circuits that are thought to underlie the development of drug-adaptive behavior. While transcriptional and epigenetic modifications are known to contribute to these circuit changes, accumulating evidence indicates that altered mRNA translation is also a key molecular mechanism. This chapter reviews recent studies demonstrating how addictive drugs alter protein synthesis and/or the translational machinery and how this leads to neuronal circuit remodeling and behavioral changes. Future work will determine precisely which neuronal circuits and cell types participate in these changes. The chapter summarizes current methodologies for identifying cell type-specific mRNAs whose translation is affected by drugs of abuse and gives recent examples of the mechanistic insights into addiction they provide.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Dvir Gur ◽  
Emily J. Bain ◽  
Kory R. Johnson ◽  
Andy J. Aman ◽  
H. Amalia Pasoili ◽  
...  

AbstractSkin color patterns are ubiquitous in nature, impact social behavior, predator avoidance, and protection from ultraviolet irradiation. A leading model system for vertebrate skin patterning is the zebrafish; its alternating blue stripes and yellow interstripes depend on light-reflecting cells called iridophores. It was suggested that the zebrafish’s color pattern arises from a single type of iridophore migrating differentially to stripes and interstripes. However, here we find that iridophores do not migrate between stripes and interstripes but instead differentiate and proliferate in-place, based on their micro-environment. RNA-sequencing analysis further reveals that stripe and interstripe iridophores have different transcriptomic states, while cryogenic-scanning-electron-microscopy and micro-X-ray diffraction identify different crystal-arrays architectures, indicating that stripe and interstripe iridophores are different cell types. Based on these results, we present an alternative model of skin patterning in zebrafish in which distinct iridophore crystallotypes containing specialized, physiologically responsive, organelles arise in stripe and interstripe by in-situ differentiation.


2021 ◽  
Vol 882 ◽  
pp. 115034
Author(s):  
A. El Guerraf ◽  
M. Bouabdallaoui ◽  
Z. Aouzal ◽  
S. Ben Jadi ◽  
N.K. Bakirhan ◽  
...  

1998 ◽  
Vol 88 (6) ◽  
pp. 1111-1115 ◽  
Author(s):  
Kalman Kovacs ◽  
Eva Horvath ◽  
Lucia Stefaneanu ◽  
Juan Bilbao ◽  
William Singer ◽  
...  

✓ The authors report on the morphological features of a pituitary adenoma that produced growth hormone (GH) and adrenocorticotropic hormone (ACTH). This hormone combination produced by a single adenoma is extremely rare; a review of the available literature showed that only one previous case has been published. The tumor, which was removed from a 62-year-old man with acromegaly, was studied by histological and immunocytochemical analyses, transmission electron microscopy, immunoelectron microscopy, and in situ hybridization. When the authors used light microscopy, the tumor appeared to be a bimorphous mixed pituitary adenoma composed of two separate cell types: one cell population synthesized GH and the other ACTH. The cytogenesis of pituitary adenomas that produce more than one hormone is obscure. It may be that two separate cells—one somatotroph and one corticotroph—transformed into neoplastic cells, or that the adenoma arose in a common stem cell that differentiated into two separate cell types. In this case immunoelectron microscopy conclusively demonstrated ACTH in the secretory granules of several somatotrophs. This was associated with a change in the morphological characteristics of secretory granules. Thus it is possible that the tumor was originally a somatotropic adenoma that began to produce ACTH as a result of mutations that occurred during tumor progression.


2014 ◽  
Vol 70 (a1) ◽  
pp. C94-C94
Author(s):  
Pawel Kuczera ◽  
Walter Steurer

The structure of d(ecagonal)-Al-Cu-Rh has been studied as a function of temperature by in-situ single-crystal X-ray diffraction in order to contribute to the discussion on energy or entropy stabilization of quasicrystals (QC) [1]. The experiments were performed at 293 K, 1223 K, 1153 K, 1083 K, and 1013 K. A common subset of 1460 unique reflections was used for the comparative structure refinements at each temperature. The results obtained for the HT structure refinements of d-Al-Cu-Rh QC seem to contradict a pure phasonic-entropy-based stabilization mechanism [2] for this QC. The trends observed for the ln func(I(T1 )/I(T2 )) vs.|k⊥ |^2 plots indicate that the best on-average quasiperiodic order exists between 1083 K and 1153 K, however, what that actually means is unclear. It could indicate towards a small phasonic contribution to entropy, but such contribution is not seen in the structure refinements. A rough estimation of the hypothetic phason instability temperature shows that it would be kinetically inaccessible and thus the phase transition to a 12 Å low T structure (at ~800 K) is most likely not phason-driven. Except for the obvious increase in the amplitude of the thermal motion, no other significant structural changes, in particular no sources of additional phason-related configurational entropy, were found. All structures are refined to very similar R-values, which proves that the quality of the refinement at each temperature is the same. This suggests, that concerning the stability factors, some QCs could be similar to other HT complex intermetallic phases. The experimental results clearly show that at least the ~4 Å structure of d-Al-Cu-Rh is a HT phase therefore entropy plays an important role in its stabilisation mechanism lowering the free energy. However, the main source of this entropy is probably not related to phason flips, but rather to lattice vibrations, occupational disorder unrelated to phason flips like split positions along the periodic axis.


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