scholarly journals New Data on Spermatogenic Cyst Formation and Cellular Composition of the Testis in a Marine Gastropod, Littorina saxatilis

2020 ◽  
Vol 21 (11) ◽  
pp. 3792
Author(s):  
Sergei Iu. Demin ◽  
Dmitry S. Bogolyubov ◽  
Andrey I. Granovitch ◽  
Natalia A. Mikhailova
Keyword(s):  
Comparative Analysis ◽  
Cyst Formation ◽  
Cellular Composition ◽  
Littorina Saxatilis ◽  
Adult Males ◽  
Fresh Tissue ◽  
Fixed Tissue ◽  
Marine Gastropod ◽  
Cyst Cell ◽  
Testis Structure

Knowledge of the testis structure is important for gastropod taxonomy and phylogeny, particularly for the comparative analysis of sympatric Littorina species. Observing fresh tissue and squashing fixed tissue with gradually increasing pressure, we have recently described a peculiar type of cystic spermatogenesis, rare in mollusks. It has not been documented in most mollusks until now. The testis of adult males consists of numerous lobules filled with multicellular cysts containing germline cells at different stages of differentiation. Each cyst is formed by one cyst cell of somatic origin. Here, we provide evidence for the existence of two ways of cyst formation in Littorina saxatilis. One of them begins with a goniablast cyst formation; it somewhat resembles cyst formation in Drosophila testes. The second way begins with capture of a free spermatogonium by the polyploid cyst cell which is capable to move along the gonad tissues. This way of cyst formation has not been described previously. Our data expand the understanding of the diversity of spermatogenesis types in invertebrates.

scholarly journals THE ULTRASTRUCTURAL LOCALIZATION OF CYTOCHROME c-OXIDASE COMPLEX IN A LIPID-RETAINING, GLUTARALDEHYDE-UREA EMBEDMENT

1974 ◽  
Vol 22 (11) ◽  
pp. 1019-1027 ◽  
Author(s):  
IZHAK NIR ◽  
DANIEL C. PEASE
Keyword(s):  
Ethylene Glycol ◽  
Kidney Tissue ◽  
Ultrastructural Localization ◽  
Precise Localization ◽  
Reaction Products ◽  
Mitochondrial Membranes ◽  
En Bloc ◽  
Fresh Tissue ◽  
Fixed Tissue ◽  
Ultrathin Sections

Kidney tissue, incubated in a phosphate-sucrose buffer with diaminobenzidine (DAB), subsequently was embedded in polymerized glutaraldehyde-urea (Pease and Peterson, 1972). The highly polar character of this embedment retains lipids in ultrathin sections and thus permits a precise localization of reaction products in relation to cytomembranes. Furthermore, since conventional organic solvents are not used during processing, it is thought that oxidized DAB polymers certainly remain in place. Their density can be enhanced by exposing mounted sections to OsO4 vapor, rather than by en bloc staining. DAB oxidation takes place only in the compartment between the inner and outer mitochondrial membranes. When aldehyde-fixed tissue is incubated, the deposits are largely limited to the intracristal spaces, whereas when fresh tissue is incubated, the entire compartment is uniformly filled. Morphologic features of fresh, unfixed tissue are stabilized by ethylene glycol and so survive incubation best when about 30% of this substance is added to the medium.

scholarly journals ULTRASTRUCTURAL DEMONSTRATION OF CYTOCHROME OXIDASE ACTIVITY BY THE NADI REACTION WITH OSMIOPHILIC REAGENTS

1967 ◽  
Vol 34 (3) ◽  
pp. 787-800 ◽  
Author(s):  
Arnold M. Seligman ◽  
Robert E. Plapinger ◽  
Hannah L. Wasserkrug ◽  
Chandicharan Deb ◽  
Jacob S. Hanker
Keyword(s):  
Cytochrome Oxidase ◽  
Oxidase Activity ◽  
Tetrazolium Salt ◽  
Tissue Slices ◽  
Fresh Tissue ◽  
Fixed Tissue ◽  
Cytochrome Oxidase Activity ◽  
Renal Tubular Cells ◽  
Renal Tubular ◽  
Rat Tissue

A new method for the subcellular and cytochemical demonstration of cytochrome oxidase has been developed with the introduction of N-benzyl-p-phenylenediamine (BPDA) and the discovery that indoanilines are osmiophilic. These indoanilines produced upon oxidation of BPDA in the presence of naphthols are highly colored compounds that yield electron-opaque coordination polymers of osmium (osmium black) that are amorphous, insoluble in water, and in organic solvents. The best methods for preparing rat tissue were in decreasing order: fixation in formaldehyde solution, fresh tissue slices, and frozen sections of fresh or fixed tissue. Ultrathin sections were counterstained by bridging with the thiocarbohydrazide-osmium tetroxide (T-O) procedure for enhancing underlying membranous structures. Cytochrome oxidase activity was noted primarily in mitochondria and occasionally in sarcotubules of heart, in mitochondria and occasionally in infoldings of the plasma membrane of renal tubular cells, and in mitochondria and, to a great extent, in endoplasmic reticulum of hepatic cells. Cytochrome oxidase activity produced deposits in droplet form, whereas dehydrogenase activity resulted in uniform staining of mitochondrial cristae, as recently demonstrated with an osmiophilic tetrazolium salt. Even more recently we have succeeded in demonstrating cytochrome oxidase activity in nondroplet staining on mitochondrial cristae with an osmiophilic benzidine-type reagent that apparently polymerizes upon oxidation (to be published later).

Spermatogenesis and lobular cyst type of testes organization in marine gastropod Littorina saxatilis (Olivi 1792)

2019 ◽  
Vol 376 (3) ◽  
pp. 457-470 ◽  
Author(s):  
Sergei Iu. Demin ◽  
Vera N. Stefanova ◽  
Andrey I. Granovitch ◽  
Natalia A. Mikhailova
Keyword(s):  
Littorina Saxatilis ◽  
Marine Gastropod ◽  
Cyst Type

Effect of formalin fixation on thermal conductivity of the biological tissue

2014 ◽  
Author(s):  
Steven C. Bauserman ◽  
Jonathan W. Valvano
Keyword(s):  
Thermal Conductivity ◽  
Biological Tissues ◽  
Formalin Fixation ◽  
Fatty Tissue ◽  
Fresh Tissue ◽  
Fixed Tissue ◽  
Tissue Samples ◽  
Formalin Fixed Tissue ◽  
Formalin Fixed

Effect of formalin fixation on thermal conductivity of the biological tissues is presented. A self-heated thermistor probe was used to measure the tissue thermal conductivity. The thermal conductivity of muscle and fatty tissue samples was measured before the formalin fixation and then 27 hours after formalin fixation. The results indicate that the formalin fixation does not cause a significant change in the tissue thermal conductivity of muscle and fatty tissues. In the clinical setting, tissues removed surgically are often fixed in formalin for subsequent pathological analysis. These results suggest that, in terms of thermal properties, it is equally appropriate to perform in vitro studies in either fresh tissue or formalin-fixed tissue.

Nanomechanical profiling of human breast tumors as prognostic marker for breast cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 11618-11618
Author(s):  
Rosemarie Anne Burian ◽  
Tobias Appenzeller ◽  
Philipp Oertle ◽  
Christian Raez ◽  
Roderick Y.H. Lim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Clinical Setting ◽  
Risk Groups ◽  
Breast Cancer Subtypes ◽  
Human Breast ◽  
Fresh Tissue ◽  
Fixed Tissue ◽  
Cancer Subtypes ◽  
Nanomechanical Properties ◽  
Cancer Aggressiveness

11618 Background: Assessment of tumor aggressiveness is crucial when making treatment decisions. Established prognostic markers may be insufficient to stratify cancer patients into treatment relevant risk groups. Emerging evidence indicates mechanical properties of cancer cells and their microenvironment play a vital role in cancer invasion and metastases. Detecting and measuring these nanomechanical changes could be a marker of cancer aggressiveness. Methods: We developed an atomic force microscope (AFM) based method: ARTIDIS (Automated and Reliable Tissue Diagnostics) for measuring nanomechanical properties of human tissue biopsies. These were performed on fresh, non-fixed tissue under physiological conditions. This novel method uses a micro-fabricated 20nm tip indenting and measuring stiffness of thousands of locations within 60-180minutes. This quantitative, biopsy-wide, nanomechanical profile strongly correlates to the tissue's biological composition. Post-AFM this biopsy is analyzed by pathology. We sought to differentiate benign from cancerous lesions based on nanomechanical properties; then link the cancerous nanomechanical profiles prospectively to the clinical outcomes. Results: Our results demonstrate the first AFM based nanomechanical profiling to detect aggressive breast cancer subtypes using fresh tissue in a clinical setting. We have shown that nanomechanical profiles of human breast cancer biopsies display stiffness profiles distinct from surrounding normal tissue. Breast cancer subtypes were distinguishable by their nanomechanical properties only. We have discovered specific nanomechanical profiles of tumor subtypes likely to metastasize. When the primary tumor displayed the same soft nanomechanical profile as adjacent tissue, this was associated with positive nodal status. Conclusions: Our results demontrate nanomechanical profiling is a fast and sensitive method to stratify malignant biopsies into relevant subgroups in a clinical setting. Relative stiffness and distribution values provide a nanomechanical profile indicating cancer aggressiveness. This will help optimize specific cancer diagnosis, orientate therapy choice and support patient follow up.

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