A simple glycerol-based freezing protocol for the semen of a marsupial Trichosurus vulpecula, the common brushtail possum

1991 ◽  
Vol 3 (2) ◽  
pp. 119 ◽  
Author(s):  
JC Rodger ◽  
SJ Cousins ◽  
KE Mate
Keyword(s):  
Phase Contrast ◽  
Frozen Storage ◽  
Neck Region ◽  
Vapour Phase ◽  
Brushtail Possum ◽  
Freezing And Thawing ◽  
Contrast Microscopy ◽  
Successful Technique ◽  
The Common ◽  
High Concentrations

Frozen storage of semen and embryos is now a well established part of the breeding of many eutherian mammals but it has not been applied to marsupials. This paper reports the first successful technique for the frozen preservation of marsupial spermatozoa. Semen was collected by electroejaculation under anaesthesia from a pool of five brushtail possums. The ejaculated semen was diluted 1:1 with Krebs Henseleit Ringer, centrifuged at 800 g for 5 min, resuspended in the test cryoprotectant media at 1, 2 and 5 x 10(6) spermatozoa mL-1 and 7, 10.5, 14 and 17.5% glycerol and then drawn up into 0.25 mL plastic straws. The spermatozoa were rapidly frozen in the vapour phase, 6 cm above liquid nitrogen, for 30 min before the straws were plunged into the liquid. Sperm motility was assessed blind for coded straws by phase-contrast microscopy on a warmed stage (35 degrees C), before freezing and after rapid thawing in a water bath at 37 degrees C (10 s). The highest recovery of both percentage motility (around 50-60%) and progressive motility (around 0.5-1 unit lower than prefreeze) occurred when spermatozoa were frozen and thawed in the presence of 17.5% glycerol. Recovery of motility was greater at the higher sperm concentrations (2 and 5 x 10(6) mL-1). There was no evidence of acrosomal damage or loss after freezing and thawing in high concentrations of glycerol. The only defect detected in spermatozoa subjected to the protocol was a variable tendency to bending of the neck region. This ranged from heads inclined at a slight angle to the tail through to complete flexure.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of the Kinetics of Salt Crystallization on Stone Damage During Rewetting/Drying and Humidity Cycling

2013 ◽  
Vol 80 (2) ◽  
Author(s):  
Julie Desarnaud ◽  
François Bertrand ◽  
Noushine Shahidzadeh-Bonn
Keyword(s):  
Sodium Sulfate ◽  
Phase Contrast ◽  
Sulfate Solution ◽  
Salt Crystallization ◽  
Severe Damage ◽  
Contrast Microscopy ◽  
Salt Crystals ◽  
High Concentrations ◽  
The Impact ◽  
Kinetics Of

In this study, we show that the key to understand why the same salt can cause damage in some conditions and not in others is the kinetics of crystallization. We present experiments assessing the impact of the recrystallization dynamics of sodium sulfate on damage observed in sandstone after repeated cycles of rewetting/drying and humidification/drying. Macroscopic and microscopic scale experiments using magnetic resonance imaging and phase contrast microscopy demonstrate that sodium sulfate that has both hydrated and anhydrous phases can lead to severe damage in sandstone during rewetting/drying cycles, but not during humidity cycling. During rewetting (a rapid process) in regions (pores) that are highly concentrated in salt, anhydrous microcrystals dissolve only partially, giving rise to a heterogeneous salt solution that is supersaturated with respect to the hydrated phase. The remaining anhydrous crystals then act as seeds for the formation of large amounts of hydrated crystals, creating grape-like structures that expand rapidly. These clusters can generate stresses larger than the tensile strength of the stone, leading to damage. On the other hand, with humidification (a slow process) and after complete deliquescence of salt crystals, the homogeneous sodium sulfate solution can reach high concentrations during evaporation without any nucleation, favoring the formation of isolated anhydrous crystals (thenardite). The crystallization of the anhydrous salt generates only very small stresses compared to the hydrated clusters and therefore causes hardly any damage to the stone.

A Study of the Male Germ-cells of the Rat and the Mouse by Phase-contrast Microscopy

1950 ◽  
Vol s3-91 (13) ◽  
pp. 73-78
Author(s):  
R.A. R. GRESSON
Keyword(s):  
Germ Cells ◽  
Phase Contrast ◽  
Neck Region ◽  
Phase Contrast Microscopy ◽  
Axial Filament ◽  
Male Germ Cells ◽  
Contrast Microscopy ◽  
Accessory Body

1. The cytoplasmic components of the male germ-cells of the rat and the mouse were examined by phase-contrast microscopy. Most of the structures seen in fixed and stained preparations were identified. 2. The localized Golgi material of spermatocytes and spermatids consists of rods and filaments. The mitochondria are granular. 3. The archoplasmic vacuole, proacrosome, developing acrosome, proximal and distal centrioles, and the axial filament were visible. A structure which may be an accessory body was observed in spermatocytes and spermatids. The manchette was visible in late spermatids of the rat but not in those of the mouse. 4. Examination of spermatozoa revealed the acrosome, the post-nuclear cap, the mitochondrial sheath, the ring centriole, and the protoplasmic bead. A granule was sometimes visible in the neck region.

Detachment of biofilm bacteria due to variations in nutrient supply

1998 ◽  
Vol 37 (4-5) ◽  
pp. 211-214 ◽  
Author(s):  
Linda K. Sawyer ◽  
Slawomir W. Hermanowicz
Keyword(s):  
Phase Contrast ◽  
Digital Image Analysis ◽  
Specific Growth ◽  
Nutrient Supply ◽  
Surface Shear Stress ◽  
Surface Shear ◽  
Nutrient Limitations ◽  
Contrast Microscopy ◽  
Biofilm Bacteria ◽  
Observable Parameter

Growth and detachment rates of an environmental isolate of Aeromonas hydrophila attached to a surface were determined under varying nutrient supply conditions in a complex medium. Growth and detachment of cells were observed in real time using phase contrast microscopy in glass parallel plate flow chambers. Surface shear stress was controlled in all experiments at 3 N m−2. Images were taken every 15 min. Digital image analysis was used to determine specific growth and detachment rates. An observable parameter proportional to the nutrient depletion at the surface due to transfer limitations was used to indicate nutrient limitations. Specific detachment rates increased as the depletion parameter increased, indicating that nutrient limitations cause this bacterium to detach at greater rates.

scholarly journals THU0406 IDENTIFICATION OF INTRACELLULAR VACUOLES IN SYNOVIAL FLUID WITH CALCIUM PYROPHOSPHATE AND MONOSODIUM URATE CRYSTALS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 440.1-441
Author(s):  
M. L. Peral ◽  
I. Calabuig ◽  
A. Martín-Carratalá ◽  
M. Andrés ◽  
E. Pascual
Keyword(s):  
Clinical Practice ◽  
Synovial Fluid ◽  
Phase Contrast ◽  
Calcium Pyrophosphate ◽  
Monosodium Urate ◽  
Fluid Analysis ◽  
Cytoplasmic Vacuoles ◽  
Contrast Microscopy ◽  
Ordinary Light ◽  
Msu Crystals

Background:Synovial fluid analysis using polarized microscopy is the gold standard for the diagnosis of crystal-related arthritis. In our experience, we have noted that, when calcium pyrophosphate (CPP) crystals are observed, they sometimes appear within intracellular vacuoles. However, this phenomenon is not seen in those samples containing monosodium urate (MSU) crystals. This finding has been scantly reported in the literature, but may be useful in clinical practice to ensure accurate crystal identification.Objectives:Our study aims to assess whether the presence of vacuoles contributes to identifying the type of crystal, and also to gauge the frequency of their presentation.Methods:We conducted an observational study in a rheumatology unit between February and June of 2019. Synovial fluids containing CPP or MSU crystals, obtained in daily clinical practice, were consecutively included for analysis. Two observers simultaneously analyzed the presence of vacuoles by ordinary light and phase contrast microscopy in less than 24 hours after their extraction, using a microscope equipped with two viewing stations. The primary study variable was to determine whether CPP and MSU crystals are seen inside intracellular vacuoles, and to calculate the frequency of this finding for each type of crystal, estimating their 95% confidence interval (95% CI) and comparing rates using Fisher’s exact test.Results:Twenty-one samples were obtained. Data is given in the Table. MSU crystals were present in 7 (33.3%) and CPP crystals in 14 (66.6%). Interestingly, none of the MSU samples showed crystal-containing vacuoles (95% CI 0-35.4%). On the contrary, cytoplasmic vacuoles containing crystals were present in all of the CPP samples (95% CI 78.5-100%). The findings were confirmed by phase-contrast microscopy. Differences were statistically significant (p<0.001).Table.SAMPLES ACCORDING TO TYPE OF MICROCRYSTAL(n=21)SAMPLES WITH VACUOLS(UNDER ORDINARY LIGHT)SAMPLES WITH VACUOLS(UNDER PHASE CONTRAST)CPP (14; 66.6%)14 (100%)(95%CI 78.5-100%)14 (100%)(95%CI 78.5-100%)MSU (7; 33.3%)0 (0%)(95%CI 0-35.4%)0 (0%)(95%CI 0-35.4%)Conclusion:The presence of vacuoles may be a useful and easy way to differentiate MSU and CPP crystals when performing synovial fluid microscopy in clinical practice, since it appears to be a distinctive feature in CPP crystal fluids.References:[1]Kohn NN, Hughes RE, McCarty DJ Jr, Faires JS. The significance of calcium phosphate crystals in the synovial fluid of arthritic patients: the «pseudogout syndrome». II. Identification of crystals. Ann InternMed. 1962 May;56:738-45.[2]Pascual E, Sivera F, Andrés M. Synovial Fluid Analysis for Crystals. CurrOpRheumatol 2011;23:161-169.[3]McCarty DJ, Koopman WJ. Arthritis and allied conditions: A textbook of rheumatology, volumen 1. Lea &amp;Febiger. 1993.[4]Pascual E, Sivera F. Synovial fluid crystal Analysis. En Gout and other crystal arthropathies. Terkeltaub R ed. Elsevier; 2012: p.20-34.[5]Hwang HS, Yang CM, Park SJ, Kim HA. Monosodium Urate Crystal-Induced Chondrocyte Death via Autophagic Process. Int J Mol Sci. 2015 Dec 8;16(12):29265-77.Image 1. Microscopy with ordinary light. Cells with cytoplasmic vacuoles are observed, as well as abundant intra and extracellular CPP crystals.Image 2. Microscopy with phase contrast technique. Cells with intracellular vacuoles are observed inside which have microcrystals with parallelepiped morphology, compatible with CPP.Disclosure of Interests: :None declared

scholarly journals Rough Dental Implant Surfaces and Peri-Implantitis: Role of Phase-Contrast Microscopy, Laser Protocols, and Modified Home Oral Hygiene in Maintenance. A 10-Year Retrospective Study

2021 ◽  
Vol 11 (11) ◽  
pp. 4985
Author(s):  
Gianluigi Caccianiga ◽  
Gérard Rey ◽  
Paolo Caccianiga ◽  
Alessandro Leonida ◽  
Marco Baldoni ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Phase Contrast ◽  
Vertical Movement ◽  
Subgingival Plaque ◽  
Phase Contrast Microscopy ◽  
Implant Surface ◽  
Total Percentage ◽  
Contrast Microscopy

The aim of this study was to evaluate two different kinds of rough implant surface and to assess their tendency to peri-implantitis disease, with a follow-up of more than 10 years. Data were obtained from a cluster of 500 implants with Ti-Unite surface and 1000 implants with Ossean surface, with a minimum follow-up of 10 years. Implants had been inserted both in pristine bone and regenerated bone. We registered incidence of peri-implantitis and other causes of implant loss. All patients agreed with the following maintenance protocol: sonic brush with vertical movement (Broxo), interdental brushes, and oral irrigators (Broxo) at least two times every day. For all patients with implants, we evaluated subgingival plaque samples by phase-contrast microscopy every 4 months for a period of more than 10-years. Ti-Unite surface implants underwent peri-implantitis in 1.6% of the total number of implants inserted and Ossean surface implants showed peri-implantitis in 1.5% of the total number of implants. The total percentage of implant lost was 4% for Ti-Unite surfaces and 3.6% for Ossean surfaces. Strict control of implants leads to low percentage of peri-implantitis even for rough surfaces dental implants.

Organic Crystals in the Tracheids of Torreya Yunnanensis

IAWA Journal ◽  
1996 ◽  
Vol 17 (4) ◽  
pp. 393-403 ◽  
Author(s):  
Yuki Kondo ◽  
Tomoyuki Fujii ◽  
Yoshioki Hayashi ◽  
Atsushi Kato
Keyword(s):  
Phase Contrast ◽  
Growth Ring ◽  
Uv Spectra ◽  
Resonance Spectroscopy ◽  
Organic Crystals ◽  
X Ray Diffraction ◽  
Cinnamic Aldehyde ◽  
X Ray ◽  
Polarised Light ◽  
Contrast Microscopy

Organic crystals were found in tracheid lumina of some samples of Torreya yunnanensis Chen ' L. K. Fu imported from Yunnan, China. Tracheids with crystals were found in short to long tangential bands along the growth ring boundaries. Because the crystals were rapidly dissolved with ethanol and xylene, cross and tangential sections were mounted in de-ionized water without staining and observed by biological, polarised light, and phase-contrast microscopy. The crystals were sublimated under vacuum during routine sample preparation for conventional SEM and only the peripheral parts remained. With the aid of low vacuum-SEM and modified cryo-SEM procedure, the shape of the crystals was revealed. Some were styloid and large enough to fill tracheid lumina, while others were stacked appearing as slates filling tracheid lumina. X-ray diffraction applied to sections and isolated crystals showed that they were single crystals and orientated along the cell wall. UV spectra on isolated crystals and methanol dissolution of crystals suggested that they were composed of phenolic compounds. Crystals that were recrystallized from methanol were analysed by 1H and l3C nuclear magnetic resonance spectroscopy. These two techniques revealed that the major and minor components were o-methoxy cinnamic acid and o-methoxy cinnamic aldehyde.

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