scholarly journals Structure of the Leydig Cell in the African Sideneck Turtle (Pelusios castaneus)

2020 ◽  
Vol 17 (2) ◽  
pp. 19-25
Author(s):  
S. G. Olukole ◽  
B. O. Oke
Keyword(s):  
Blood Vessels ◽  
Leydig Cell ◽  
Comparative Anatomy ◽  
West African ◽  
Freshwater Turtle ◽  
Seminiferous Tubules ◽  
Transmission Electron ◽  
Entire Cell ◽  
Rough Endoplasmic Reticula ◽  
Endoplasmic Reticula

The African sideneck turtle (Pelusios castaneus) is a freshwater turtle of West African origin used in traditional medicine with little consumption as meat. There have been documentations on the reproductive biology of the turtle with no report on the structure of the Leydig cell of the animal. We described the structure of the Leydig cell of the adult African sideneck turtle using histology, microstereology and transmission electron microscopy. The Leydig cell of the African sideneck turtle were elliptical in shape when found proximal to blood vessels and elongated at other points within the testicular interstitium. Leydig cells occurred in cords or clusters of varying sizes and numbers (3-5 cells) that appear to be random in distribution possessing round to ovoid nuclei containing small amount of peripherally disposed heterochromatin with prominent nucleoli. The seminiferous tubules of the turtle occupied about 85% of the total testicular parenchyma while the interstitium occupied 15% of it. Of this 15%, the Leydig cell occupied about 10% while the stromal elements, inclusive of blood vessels occupied the remaining 5%. The cytoplasm of the Leydig cell was about 85% of the entire cell and comprised microfilaments, lipid droplets, smooth and rough endoplasmic reticula as well as numerous mitochondria. In conclusion, the histological and ultrastructural features of the Leydig cell of the African sideneck turtle bear close similarities with those of other reptiles with little variations. These variations include interstitial location as well as in relation to blood vessels within the testicular interstitium. Information made available by this study is expected to be useful in the comparative anatomy of the Leydig cell of turtles and reptiles.

scholarly journals Nano-imaging trace elements at organelle levels in substantia nigra overexpressing α-synuclein to model Parkinson’s disease

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Laurence Lemelle ◽  
Alexandre Simionovici ◽  
Philippe Colin ◽  
Graham Knott ◽  
Sylvain Bohic ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Substantia Nigra ◽  
Trace Element ◽  
Brain Diseases ◽  
Transmission Electron ◽  
Rough Endoplasmic Reticula ◽  
Nano Imaging ◽  
Cellular Compartments ◽  
Endoplasmic Reticula

AbstractSub-cellular trace element quantifications of nano-heterogeneities in brain tissues offer unprecedented ways to explore at elemental level the interplay between cellular compartments in neurodegenerative pathologies. We designed a quasi-correlative method for analytical nanoimaging of the substantia nigra, based on transmission electron microscopy and synchrotron X-ray fluorescence. It combines ultrastructural identifications of cellular compartments and trace element nanoimaging near detection limits, for increased signal-to-noise ratios. Elemental composition of different organelles is compared to cytoplasmic and nuclear compartments in dopaminergic neurons of rat substantia nigra. They exhibit 150–460 ppm of Fe, with P/Zn/Fe-rich nucleoli in a P/S-depleted nuclear matrix and Ca-rich rough endoplasmic reticula. Cytoplasm analysis displays sub-micron Fe/S-rich granules, including lipofuscin. Following AAV-mediated overexpression of α-synuclein protein associated with Parkinson’s disease, these granules shift towards higher Fe concentrations. This effect advocates for metal (Fe) dyshomeostasis in discrete cytoplasmic regions, illustrating the use of this method to explore neuronal dysfunction in brain diseases.

Evidence for a Blood Ganglion Barrier in the Superior Cervical Ganglion of the Rat

1982 ◽  
Vol 40 ◽  
pp. 204-204
Author(s):  
D. M. DePace
Keyword(s):  
Blood Vessels ◽  
Superior Cervical Ganglion ◽  
Peripheral Nerves ◽  
Time Schedule ◽  
Transmission Electron ◽  
Cervical Ganglion ◽  
The Central Nervous System ◽  
Cervical Ganglia ◽  
Capillary Circulation ◽  
And Control

The majority of blood vessels in the superior cervical ganglion possess a continuous endothelium with tight junctions. These same features have been associated with the blood brain barrier of the central nervous system and peripheral nerves. These vessels may perform a barrier function between the capillary circulation and the superior cervical ganglion. The permeability of the blood vessels in the superior cervical ganglion of the rat was tested by intravenous injection of horseradish peroxidase (HRP). Three experimental groups of four animals each were given intravenous HRP (Sigma Type II) in a dosage of.08 to.15 mg/gm body weight in.5 ml of.85% saline. The animals were sacrificed at five, ten or 15 minutes following administration of the tracer. Superior cervical ganglia were quickly removed and fixed by immersion in 2.5% glutaraldehyde in Sorenson's.1M phosphate buffer, pH 7.4. Three control animals received,5ml of saline without HRP. These were sacrificed on the same time schedule. Tissues from experimental and control animals were reacted for peroxidase activity and then processed for routine transmission electron microscopy.

Quantification of cell-surface expressed antigenic sites with 5-nm gold markers: Getting close to biologically relevant data

1989 ◽  
Vol 47 ◽  
pp. 1050-1051
Author(s):  
Etienne de Harven ◽  
Hilary Christensen ◽  
Richard Leung ◽  
Cameron Ackerley
Keyword(s):  
Cell Surface ◽  
Human Peripheral Blood ◽  
Contour Length ◽  
Thin Sections ◽  
Gold Particles ◽  
Biologically Relevant ◽  
Transmission Electron ◽  
Entire Cell ◽  
Electron Imaging ◽  
Cell Contour

The T-derived subset of human peripheral blood normal lymphocytes has been selected as a model system to study the usefulness of 5 nm gold markers for quantification of single epitopes expressed on cell surfaces. The chosen epitopes are parts of the CD3 and CD5 molecules and can be specifically identified by hybridoma produced monoclonal antibodies (MoAbs; LEU-4 and LEU-1; Becton-Dick- inson, Mountain view, CA) . An indirect immunolabeling procedure, with goat anti-murine IgG adsorbed on the surface of 5 nm colloidal gold particles (GAM-G5, Janssen Pharmaceutica, Beerse, Belgium) has been used. Backscattered Electron Imaging (BEI) in a field emission scanning electronmicroscope (SEM) and transmission electron microscopy of thin sections of lymphocytes labeled before plastic embedding, were both used to identify and quantitate gold labeled cell surface sites, Estimating that the thickness of “silver” sections is approximately 60 nm and counting the number of gold particles on the entire cell perimeter, we calculated that, for LEU-4, the number of markers per um2 of cell surface is in the 140-160 range (Fig.l). Cell contour length measurements indicated that the surface of one lymphocyte is approximately 130-160 um2 that of a smooth sphere of identical diameter, reflecting the role of microvilli in expanding the surface area. The total number of gold labeled sites on the surface of one lymphocyte averages, therefore between 20,000 and 24,000 per cell.

Spermatogenesis and testicular tumours in ageing dogs

Reproduction ◽  
2000 ◽  
pp. 443-452 ◽  
Author(s):  
MA Peters ◽  
DG de Rooij ◽  
KJ Teerds ◽  
I van Der Gaag ◽  
FJ van Sluijs
Keyword(s):  
Sertoli Cell ◽  
Leydig Cell ◽  
Seminiferous Tubules ◽  
Score System ◽  
Testicular Tumours ◽  
Severe Impairment ◽  
Per Se ◽  
Testicular Disease ◽  
Sertoli Cell Tumours ◽  
Leydig Cell Tumours

Spermatogenesis was examined in testes from 74 dogs of various breeds without clinically detected testicular disease. A modified Johnsen score system was used to determine whether spermatogenesis deteriorates with ageing. The diameter of seminiferous tubules was measured in dogs without testicular disease to examine other possible effects of ageing on tubular performance. There appeared to be no relation between age and these variables. The influence of testicular tumours on spermatogenesis was also investigated in both affected and unaffected testes. The testes of 28 dogs with clinically palpable tumours and 21 dogs with clinically non-palpable tumours were investigated. In cases of unilateral occurrence of a tumour, impairment of spermatogenesis was observed only in the affected testis of dogs with clinically detected tumours. Bilateral occurrence of tumours, whether detected clinically or non-clinically, was associated with severe impairment of spermatogenesis. The prevalence of tumours increased during ageing. Eighty-six per cent of the clinically detected and 57% of the non-clinically detected tumours were found in old dogs. Multiple types of tumour and bilateral occurrence were very common. Seminomas and Leydig cell tumours were more frequent than Sertoli cell tumours. It was concluded that spermatogenesis per se did not decrease during ageing in dogs but the occurrence of testicular tumours increased with ageing and affected spermatogenesis significantly, as reflected by a lower Johnsen score.

VEGF-dependent plasticity of fenestrated capillaries in the normal adult microvasculature

2006 ◽  
Vol 290 (2) ◽  
pp. H560-H576 ◽  
Author(s):  
Tomomi Kamba ◽  
Betty Y. Y. Tam ◽  
Hiroya Hashizume ◽  
Amy Haskell ◽  
Barbara Sennino ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Kinase Inhibitor ◽  
Normal Function ◽  
Epididymal Adipose Tissue ◽  
Vegf Receptor ◽  
Adult Mice ◽  
Fenestrated Capillaries ◽  
Transmission Electron ◽  
Vegf Inhibition ◽  
Dose Dependent

Unlike during development, blood vessels in the adult are generally thought not to require VEGF for normal function. However, VEGF is a survival factor for many tumor vessels, and there are clues that some normal blood vessels may also depend on VEGF. In this study, we sought to identify which, if any, vascular beds in adult mice depend on VEGF for survival. Mice were treated with a small-molecule VEGF receptor (VEGFR) tyrosine kinase inhibitor or soluble VEGFRs for 1–3 wk. Blood vessels were assessed using immunohistochemistry or scanning or transmission electron microscopy. In a study of 17 normal organs after VEGF inhibition, we found significant capillary regression in pancreatic islets, thyroid, adrenal cortex, pituitary, choroid plexus, small-intestinal villi, and epididymal adipose tissue. The amount of regression was dose dependent and varied from organ to organ, with a maximum of 68% in thyroid, but was less in normal organs than in tumors in RIP-Tag2-transgenic mice or in Lewis lung carcinoma. VEGF-dependent capillaries were fenestrated, expressed high levels of both VEGFR-2 and VEGFR-3, and had normal pericyte coverage. Surviving capillaries in affected organs had fewer fenestrations and less VEGFR expression. All mice appeared healthy, but distinct physiological changes, including more efficient blood glucose handling, accompanied some regimens of VEGF inhibition. Strikingly, most capillaries in the thyroid grew back within 2 wk after cessation of treatment for 1 wk. Our findings of VEGF dependency of normal fenestrated capillaries and rapid regrowth after regression demonstrate the plasticity of the adult microvasculature.

scholarly journals Effects of High Hydrostatic Pressure Processing on the Number of Bacteria and Texture of Beef Liver

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Hirokazu Ogihara ◽  
Hodaka Suzuki ◽  
Masaki Michishita ◽  
Hitoshi Hatakeyama ◽  
Yumiko Okada
Keyword(s):  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Ultrastructural Analysis ◽  
Lower Pressure ◽  
Mitochondrial Swelling ◽  
Beef Liver ◽  
High Hydrostatic Pressure Processing ◽  
Rough Endoplasmic Reticula ◽  
Endoplasmic Reticula ◽  
Number Of Bacteria

Providing beef liver for raw consumption was banned in Japan on July 1, 2012. To lift the ban, the establishment of effective countermeasures for safe raw consumption is necessary. In this study, we examined the effects of high hydrostatic pressure processing on raw beef liver. Beef liver samples subjected to 300 MPa of pressure or higher for 10 min at 25°C became firmer and showed a paler color and were considered unsuitable for raw consumption. More than 3.0 log reductions of bacteria were seen after treatments at 400 and 500 MPa, but the treatment with lower pressure did not show enough microcidal effects for safe consumption. Histological and ultrastructural analysis revealed that high hydrostatic pressure processing increased mitochondrial swelling and reduced rough endoplasmic reticula in hepatocytes, and such changes might be related to the observed changes of texture in the treated raw beef liver.

scholarly journals Ultrastructure of the adrenal gland of paca (Cuniculus paca, Linnaeus, 1766) in captivity

2021 ◽  
Vol 15 (3) ◽  
pp. 203-208
Author(s):  
Sérgio Pinter Garcia Filho ◽  
Leandro Luis Martins ◽  
Paulo Fernandes Marcusso ◽  
Tais Harumi de Castro Sasahara ◽  
Márcia Rita Fernandes Machado
Keyword(s):  
Electron Microscopy ◽  
Adrenal Gland ◽  
Adrenal Glands ◽  
Comparative Anatomy ◽  
The Body ◽  
Cortical Region ◽  
Lateral Incision ◽  
Transmission Electron ◽  
In Captivity ◽  
Microscopy Techniques

Lowland paca (Cuniculus paca, Linnaeus, 1766) is a medium-sized rodent that belongs to the Brazilian fauna. Yet little information on its morphology is found in the specialized literature. Thus, the objective of the work was to study the morphology of the adrenal gland of paca by means of microscopic ultrastructure analysis. The adrenal gland secretes specialized substances in the body which promote biological functions of great importance and will provide valuable information to studies in comparative anatomy. Two (2) adult lowland pacas were used, male and female. Soon after death, the animals were positioned in the supine position; their abdominal cavities were opened by pre-retro umbilical and lateral incision followed by folding of the abdominal walls to expose the glands. The adrenal glands were removed; fragments were collected, fixed and prepared for ultrastructure observations using scanning electron microscopy and transmission electron microscopy techniques. It was observed that the adrenal glands of the paca have divisions as well as the limits of the cortical and medullary region, as well as the subdivisions of the glomerulosa, fasciculated and reticulated areas of the cortical region as in other rodents. An ultrastructure of cells and their components also showed a lot of similarity to that already demonstrated in different rodents.

Fine structural observation on the oogenesis and vitellogenesis of the Chinese soft-shelled turtle (Pelodiseus sinensis)

Zygote ◽  
2009 ◽  
Vol 18 (2) ◽  
pp. 109-120 ◽  
Author(s):  
Hei Nainan ◽  
Yang Ping ◽  
Yang Yang ◽  
Liu Jinxiong ◽  
Bao Huijun ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Special Functions ◽  
Dorsal Surface ◽  
Sibling Relationship ◽  
Follicular Epithelium ◽  
Follicular Cells ◽  
Cell Organelles ◽  
Rough Endoplasmic Reticula ◽  
Relationship Of ◽  
Endoplasmic Reticula

SummaryFine structure observations were performed by means of electron microscopy on oogenesis and vitellogenesis and the special functions of follicular cells in the Chinese soft-shelled turtle (Pelodiseus sinensis). Histological examination of the ovary showed a well developed lacunae system containing fine granules, fibres or gelatiniform materials with one or two germinal beds dispersed on the dorsal surface of the ovarian cortex. The process of oogenesis comprised 10 consecutive phases according to the morphology of the yolk platelets, follicular cells and zona pellucida (ZP). Electron microscopy of vitellogenesis revealed some of the mitochondria gradually being transformed into yolk granules. In the advanced stage of vitellogenesis, large amounts of rough endoplasmic reticula, Golgiosomes and other cell organelles that are involved in synthesis and secretion were observed in follicular cells. The ZP was formed by microvilli, thus increasing the absorptive surface of the oocyte and facilitating transport of nutrients from the follicular epithelium to the ooplasm. This study demonstrated that the ovaries of members of the Testudinidae share more features with Archosaurs than with Squamates, indicating that these features were phylogenetically conserved in the Archosauria. The present observations suggest that the accumulation of yolk materials was controlled by the intrinsic and extrinsic pathways as well as by the activity of follicular cells. These results might also support a sibling relationship of the Testudinidae with the Archosauria and not with all extant reptiles.

THE INFLUENCE OF OVERCROWDING ON SPERMATOGENESIS, SIZE OF LEYDIG-CELL NUCLEI (HISTOMETRICAL INVESTIGATION), AND THE ADRENAL CORTICOSTERONE CONTENTS IN MICE

1973 ◽  
Vol 74 (4) ◽  
pp. 783-791 ◽  
Author(s):  
K. Gärtner ◽  
H. Reznik-Schüller ◽  
G. Reznik
Keyword(s):  
Population Size ◽  
Group Size ◽  
Adult Male ◽  
Leydig Cell ◽  
Relative Frequency ◽  
Seminiferous Tubules ◽  
Cell Nuclei ◽  
Nmri Mice ◽  
Testosterone Secretion ◽  
Adrenal Corticosterone

ABSTRACT Adult male NMRI-mice were kept alone or in groups of 5, 10, 20, 30, 40 and 60 animals for 28 days and were then sacrificed. The corticosterone levels of their adrenals were determined and their testes were examined histometrically. The corticosterone levels of the adrenals increased two-fold with increasing population size. Furthermore the increased population size caused a suppression of some testicular functions: the seminiferous tubules decreased up to 20 % and the relative frequency of the spermatids up to 10 % whereas the numbers of spermatocytes and spermatogonias increased correspondingly. A decrease of about 25 % of the testosterone dependent postmeiotic stages of spermatogenesis is assumed. Since the diameters of the Leydig-cell nuclei decreased about 20 %, a reduction of the testicular testosterone secretion can be projected. All measurements proved the group with 5 animals to be the most favourable group size.

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