Ultra‐thin sectioning and grinding of epoxy plastinated tissue     

Mircea Constantin Sora  Christoph von Horst  Octavio Lpez-Albors  Rafael Latorre 《Anatomia, histologia, embryologia》2019,48(6):564-571

With classical sheet plastination techniques such as E12, the level and thickness of the freeze‐cut sections decide on what is visible in the final sheet plastinated sections. However, there are other plastination techniques available where we can look for specific anatomical structures through the thickness of the tissue. These techniques include sectioning and grinding of plastinated tissue blocks or thick slices. The ultra‐thin E12 technique, unlike the classic E12 technique, starts with the plastination of a large tissue block. High temperatures (30–60°C) facilitate the vacuum‐forced impregnation by decreasing the viscosity of the E12 and increasing the vapour pressure of the intermediary solvent. By sectioning the cured tissue block with a diamond band saw plastinated sections with a thickness of <300 μm can be obtained. The thickness of plastinated sections can be further reduced by grinding. Resulting sections of <100 µm are suitable for histological staining and microscopic studies. Anatomical structures of interest in thick plastinate slices can be followed by variable manual grinding in a method referred to as Tissue Tracing Technique (TTT). In addition, the tissue thickness can be adapted to the transparency or darkness of tissue types in different regions of the same plastinated section. The aim of this study was to evaluate the advantages of techniques based on sectioning and grinding of plastinated tissue (E12 ultra‐thin and TTT) compared to conventional sheet‐forming techniques (E12).  相似文献   

E12 technique: Conventional epoxy resin sheet plastination     

Rafael Latorre  Kees de Jong  Mircea‐Constantin Sora  Octavio Lpez‐Albors  Carlos Baptista 《Anatomia, histologia, embryologia》2019,48(6):557-563

Epoxy plastination techniques were developed to obtain thin transparent body slices with high anatomical detail. This is facilitated because the plastinated tissue is transparent and the topography of the anatomical structures well preserved. For this reason, thin epoxy slices are currently used for research purposes in both macroscopic and microscopic studies. The protocol for the conventional epoxy technique (E12) follows the main steps of plastination—specimen preparation, dehydration, impregnation and curing/casting. Preparation begins with selection of the specimen, followed by freezing and slicing. Either fresh or fixed (embalmed) tissue is suitable for epoxy plastination, while slice thickness is kept between 1.5 and 3 mm. Impregnation mixture is made of epoxy E12 resin plus E1 hardener (100 ppw; 28 ppw). This mixture is reactive and temperature sensitive, and for this reason, total impregnation time under vacuum at room laboratory temperature should not last for more than 20–24 hr. Casting of impregnated slices is done in either flat chambers or by the so‐called sandwich method in either fresh mixture or the one used for impregnation. Curing is completed at 40°C to allow a complete polymerization of the epoxy‐mixture. After curing, slices can be photographed, scanned or used for anatomical study under screen negatoscope, magnification glass or fluorescent microscope. Based on epoxy sheet plastination, many anatomical papers have recent observations of and/or clarification of anatomical concepts in different areas of medical expertice.  相似文献   

Impact of silicon-based quantum dots on the antioxidative system in white muscle of Carassius auratus gibelio     

Stanca L  Petrache SN  Radu M  Serban AI  Munteanu MC  Teodorescu D  Staicu AC  Sima C  Costache M  Grigoriu C  Zarnescu O  Dinischiotu A 《Fish physiology and biochemistry》2012,38(4):963-975

Silicon-based quantum dots were intraperitoneally injected in individuals of Carassius auratus gibelio. Their effects on white muscle were investigated by following their distribution and impact on the antioxidative system. The GSH level significantly increased after 1 and 3?days of exposure by, respectively, 85.3 and 25.4%. Seven days later, GSH levels were similar to control concentrations. MDA concentration rose after three days by 46.9% and remained at the same level after 7?days. Protein thiol levels significantly decreased by 6.7 and 8.1% after 3 and 7?days, whereas advanced oxidation protein products increased by 12.7, respectively, 28.1% in the same time intervals. The protein reactive carbonyl groups were raised only after the first day of exposure and returned to the control level later on. SOD specific activity increased up to 48% after 7?days, while CAT activity increased by 328, 176, and 26% after 1, 3, and 7?days of treatment. GST specific activity was up-regulated by 87, 18, and 9%, while GR activity increased by 68, 34, and 9%. G6PD activity was up-regulated by 12, 22, and 50%, whereas GPx activity raised by 75 and 109% compared to control after, respectively, 1, 3, and 7?days. Our results suggest that oxidative stress induced by silicon-based quantum dots was not strong enough to cause permanent damage in the white muscle of crucian carp.  相似文献   

Comparison of biuret and refractometry methods for the serum total proteins measurement in ruminants          下载免费PDF全文

Panagiotis D. Katsoulos  Labrini V. Athanasiou  Maria A. Karatzia  Nektarios Giadinis  Harilaos Karatzias  Constantin Boscos  Zoe S. Polizopoulou 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2017,46(4):620-624

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Urine protein-to-creatinine ratio in cattle with subclinical renal disease     

Panagiotis D. Katsoulos  Labrini V. Athanasiou  Dimitra Psalla  Christina Marouda  Maria Papchianou  Anestis Tsitsos  Constantin Boscos  Zoe S. Polizopoulou 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2020,49(1):66-70

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Über Haubarkeits- und Zwischennutzung und deren Wechselverhältnis in der Waldertragsregelung     

Dr. oec. publ. Constantin G. Sklawunos 《European Journal of Forest Research》1923,45(12):451-470

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Efficiency of three boar sperm enrichment techniques     

Athina Basioura  Georgios Tsousis  Constantin M. Boscos  Ioannis A. Tsakmakidis 《Reproduction in domestic animals》2021,56(8):1148-1151

The objective of the study was to investigate the efficiency of three enrichment methods to separate boar spermatozoa. Twenty-four ejaculates from 12 boars (2 ejaculates/boar) were extended (30 × 10⁶ spermatozoa/mL) in commercial Beltsville Thawing Solution. Each semen sample was processed with glass wool column (GW) and glass beads (GB) filtration and with the single-layer centrifugation (SLC) technique. Semen samples before (control; C) and after treatment were evaluated for sperm CASA motility/kinetics and concentration, viability, morphology and chromatin integrity. Data were analysed with mixed models. The concentration of total and motile spermatozoa was significantly decreased after treatment in groups GW and SLC, but not in group GB. Group GW showed increased values of WOB compared with both groups C and GB. Group GB showed greater values of rapid movement spermatozoa and lower values of slow movement spermatozoa compared with group C. In group SLC, higher values of VSL, LIN and STR were observed compared with group C. In conclusion, all techniques under examination enhanced various CASA variables. Based on our results, the GB method is a promising alternative separation technique for boar sperm and deserves further research regarding swine in vitro fertilization.  相似文献   

Variations in the secondary metabolite camptothecin in relation to tissue age and season in Camptotheca acuminata     

Liu Z  Carpenter SB  Bourgeois WJ  Yu Y  Constantin RJ  Falcon MJ  Adams JC 《Tree physiology》1998,18(4):265-270

We investigated variation in concentration of the secondary metabolite, camptothecin (CPT), in relation to leaf, branch and tree age, season, and leaf drying method in Camptotheca acuminata Decaisne saplings. Younger leaves contained higher CPT concentrations than older leaves. Within a branch, there was a linear decline in CPT concentration from leaves at the apex of the branch down to Leaf 7. Comparing leaves of similar age, those from younger trees had higher CPT concentrations than those from older trees. Over the course of the growing season, there was a steady decline of 11% per month in leaf CPT concentration. Branches showed a similar seasonal decline in CPT concentration to leaves; however, the rate of decline was threefold greater in leaves than in branches. Freeze-dried tissues had a 27% higher CPT concentration than oven- or air-dried tissues, suggesting that oven- and air-drying caused degradation of CPT. The decline in CPT concentration with tissue aging may reflect a genetically determined mechanism whereby, in young trees, chemicals serve as a first line of defense against attacks by herbivores and pathogenic microorganisms until other mechanisms are developed and deployed. We hypothesize that chemical defense mechanisms are programmed for early ontogenic stages, whereas they are induced by biotic and abiotic factors during later ontogenic stages.  相似文献   

Farbstoffpflanzen im Mittleren Osten I. Farbstoffpflanzen aus Transkaukasien     

Constantin Regel 《Plant foods for human nutrition (Dordrecht, Netherlands)》1957,2(2):112-122

Résumé L'auteur donne un aperçu des plantes colorifiantes, employées surtout pour la fabrication des tapis, dans la région autonome de Karabakh Azerbeidshan. Il se base surtout sur un travail deGrounska-Petrov. Le livre important derGrossheim sur les matières premières végétales du Caucase n'a pu être consulté.  相似文献   

Midbrain control of three-dimensional head orientation     

Klier EM  Wang H  Constantin AG  Crawford JD 《Science (New York, N.Y.)》2002,295(5558):1314-1316

Little is known about the neural mechanisms controlling head posture and why they fail in clinical syndromes like torticollis. It is well established, however, that the brain controls eye position by integrating eye velocity commands. By electrically stimulating and reversibly inactivating midbrain sites in the head-free (nonimmobilized) monkey, we found that the interstitial nucleus of Cajal functions as a neural integrator for head posture. We suggest that a bilateral imbalance in this structure, through either direct damage or inappropriate input, could be one of the mechanisms underlying torticollis.  相似文献