scholarly journals Isolation of intact and pure chloroplasts from leaves of Arabidopsis thaliana plants acclimated to low irradiance for studies on Rubisco regulation

2012 ◽  
Vol 81 (4) ◽  
pp. 91-95 ◽  
Author(s):  
Magda Grabsztunowicz ◽  
Grzegorz Jackowski
Keyword(s):  
Arabidopsis Thaliana ◽  
Phase Contrast ◽  
Low Cost ◽  
Phase Contrast Microscopy ◽  
Differential Centrifugation ◽  
Percoll Gradient ◽  
Contrast Microscopy ◽  
Leaf Homogenate

<p>A protocol is presented for low-cost and fast isolation of intact and pure chloroplasts from leaves of plants acclimated to low irradiance. The protocol is based on a differential centrifugation of cleared leaf homogenate and omits a centrifugation on Percoll gradient step. The intactness and purity of the chloroplasts isolated from leaves of low irradiance-acclimated plants by using this protocol (confirmed by phase contrast microscopy as well as enzymatic and immunological approaches) allows plausible studies on low irradiance-dependent Rubisco regulation.</p>

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.

scholarly journals Coherent noise reduction in digital holographic phase contrast microscopy by slightly shifting object

2011 ◽  
Vol 19 (5) ◽  
pp. 3862 ◽  
Author(s):  
Feng Pan ◽  
Wen Xiao ◽  
Shuo Liu ◽  
FanJing Wang ◽  
Lu Rong ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Phase Contrast ◽  
Phase Contrast Microscopy ◽  
Coherent Noise ◽  
Contrast Microscopy

In vitro Maturation of the Exoerythrocytic Stage of Plasmodium knowlesi Observed under Phase Contrast Microscopy

1990 ◽  
Vol 76 (6) ◽  
pp. 923 ◽  
Author(s):  
Pascal Millet ◽  
William E. Collins ◽  
Claude E. Monken ◽  
Bobby G. Brown
Keyword(s):  
Phase Contrast ◽  
In Vitro Maturation ◽  
Plasmodium Knowlesi ◽  
Phase Contrast Microscopy ◽  
Contrast Microscopy

scholarly journals 209FUNCTIONAL ASSESSMENT OF WHITE RHINOCEROS CERATHOTERIUM SIMUM EPIDIDYMAL SPERMATOZOA BEFORE AND AFTER CRYOPRESERVATION

2004 ◽  
Vol 16 (2) ◽  
pp. 226 ◽  
Author(s):  
F. Martinez-Pastor ◽  
F. Olivier ◽  
T. Spies ◽  
L. Anel ◽  
P. Bartels
Keyword(s):  
Plasma Membrane ◽  
Assisted Reproduction ◽  
Phase Contrast ◽  
Egg Yolk ◽  
Phase Contrast Microscopy ◽  
White Rhinoceros ◽  
Contrast Microscopy ◽  
Before And After ◽  
Epididymal Spermatozoa

Biological Resource Banks represent a potentially valuable tool for species conservation. It is, however, necessary to understand the species-specific cryopreservation process and its consequences for spermatozoa to aid in the development of assisted reproduction as a future conservation tool. The aim of this study was to assess the in vitro functionality of white rhinoceros Cerathoterium simum epididymal spermatozoa both before and after cryopreservation. Testes from a harvested white rhino bull were removed and transported at 5°C to the laboratory within 4h. The cauda epididymis was dissected out and flushed with 2mL of Tris-citrate egg yolk extender (fraction A, Biladyl, Minitüb, Germany). A 0.1mL aliquot was removed for analysis and the balance (9mL; 2mL fraction A+7mL sperm sample) mixed with an additional 27.2mL of Tris-citrate egg yolk with glycerol (fraction B, Bidadyl). The extended sample was allowed to cool to 4°C over a 6-h period before an additional 29.2mL of cooled fraction B were added (final sperm concentration=150×106mL−1). Sperm samples were loaded into 0.25-mL straws and frozen over LN2 vapor (4cm for 20min) for later assessment. Sperm straws were thawed by placing the straws in water at 37°C for 30s. Pre-freeze and post-thaw evaluations were carried out in the same manner. Media used included: HEPES for washing (20mM HEPES, 355mM sucrose, 10mM glucose, 2.5mM KOH) and HEPES saline (197mM NaCl, instead of sucrose). An aliquot was diluted with HEPES (washing) and centrifuged for 5min at 600×g; the pellet was resuspended in HEPES saline. Sperm motility (total motility %, TM;; and progressive motility %, PM) was assessed using phase contrast microscopy (×200; 37°C). Sperm plasma membrane status was assessed using the fluorescent dye, propidium iodide (50ngmL−1 in HEPES saline;; 10min, RT). Percentage of cells with plasma membranes intact (unstained;; PMI) was recorded. Mitochondrial status was assessed with the fluorescent dye, JC-1 (7.5μM in HEPES saline;; 30min, 37°C). The % of cells with an orange-stained midpiece was recorded (active mitochondria;; MIT). Resilience to hypoosmotic shock (HOS test) was assessed by diluting a sample in 100mOsm/kg HEPES saline (1:20; 15min, RT). An aliquot was stained with PI to assess plasma membrane status (HOSPMI), and the rest was fixed with formaldehyde, and % coiled tails (positive endosmosis;; HOST) was estimated using phase contrast microscopy (×400). Evaluations of PMI, MIT and HOSPMI were performed using fluorescence microscopy (×400, 450–490nm excitation filter). The results indicated that quality was good pre-freezing (TM: 60%; PMI: 86%; MIT: 100%), except for a PM value of 15%. After thawing, although there was a drop in TM (30%), there was no decrease in PM (20%). Our in vitro functional assessment indicated a loss of quality between the pre-freeze and post-thaw evaluations, but PMI and MIT maintained their pre-thaw levels (60% and 72%, respectively). The HOS test, which indicates plasma membrane integrity, decreased from the pre-freeze level (91%) to a post-thaw value of 70%. HOSTPMI was 72% pre-freeze, and decreased to 54% post-thaw. In conclusion, epididymal spermatozoa from the white rhino may retain its functionality after cryopreservation in a commerically available cryo-extender (Bidadyl). The use of assisted reproduction techniques could someday play a role in the management and conservation of the white rhinoceros and related species.

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