69 REMOVAL OF CUMULUS CELLS AND PRE-INCUBATION IN CYTOCHALASIN B IMPROVE SURVIVAL OF IMMATURE CAT OOCYTES DURING VITRIFICATION

2008 ◽  
Vol 20 (1) ◽  
pp. 115 ◽  
Author(s):  
P. Comizzoli ◽  
D. E. Wildt ◽  
B. S. Pukazhenthi

Vitrification might be the best option to cryopreserve the immature cat oocyte because our recent studies have demonstrated that COCs are (1) highly sensitive to cryoprotectant (CPA) and require short-term exposure to prevent toxicity, and yet (2) resistant to extreme hyperosmotic conditions when pre-incubated in the cytoskeleton stabilizer cytochalasin B (CB). However, surrounding cumulus cells may inhibit the necessary rapid transport of water and CPA across the oocyte membrane during short-term exposure to vitrification solutions (VS) containing high CPA concentrations. The objective was to examine the influence of cumulus cells on oocyte survival during vitrification with or without pre-incubation in CB. Our metric of focus was the chromatin status after warming and IVM. Grade I immature oocytes (n = 420, 4 replicates) were equally allocated to one of four treatments: T1 (removal of cumulus cells in 0.2% hyaluronidase); T2 (pre-incubation in 7.5 µg mL–1 CB for 20 min); T3 (removal of cumulus cells and pre-incubation in CB (as above)); and T4 (control, no removal of cumulus cells and no pre-incubation in CB). After each treatment, half of the oocytes was washed and immediately cultured for IVM (28 h; denuded oocytes being co-cultured with an equal number of fresh COCs to circumvent the absence of cumulus cells). The other half was exposed to 10% (v/v) ethylene glycol (EG) + 10% (v/v) DMSO for 30 s, followed by exposure to VS (20% EG + 20% DMSO + 0.5 m sucrose) for 20 s at room temperature. Oocytes then were vitrified in <1 µL of VS at the tip of a plastic gutter (2 oocytes/gutter) by direct plunge into liquid nitrogen. After 1 day of storage, vitrified oocytes were warmed in 0.25 m sucrose, extensively washed, and cultured for IVM as described above. All oocytes were then fixed and Hoechst-stained to assess their chromatin status. Oocytes subjected to T1, T2, T3, and T4 without vitrification exhibited no degenerated chromatin (clumped or dispersed) after IVM. After vitrification, the incidence of degenerated chromatin was different (P < 0.05; ANOVA) among treatments, with a lower percentage (P < 0.05) when oocytes were subjected to T3 (15.5 � 3.9%; mean � SD) compared to T1 (26.6 � 3.1%), T2 (48.9 � 3.8%), or T4 (71.1 � 3.8%). The percentage of vitrified oocytes reaching the metaphase II stage (MII) also was different (P < 0.05) among treatments with a higher incidence (P < 0.05) in the T3 group (57.8 � 3.9%) compared to T1 (44.6 � 3.7%), T2 (31.1 � 7.7%), or T4 (15.5 � 3.9%) counterparts. Percentages of non-vitrified oocytes reaching the MII were not different (P > 0.05) among treatments (range, 84.7 to 89.0%) but were higher (P < 0.05) compared to vitrified oocytes. The combination of removal of cumulus cells and pre-incubation in CB prior to vitrification had a cumulative, beneficial influence on cat oocyte survival. Interestingly, removal of cumulus cells imparted a greater benefit on oocyte survival than CB pre-incubation alone.

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Juan Sebastian Yakisich ◽  
Yogesh Kulkarni ◽  
Neelam Azad ◽  
Anand Krishnan V. Iyer

The presence of highly resistant cancer cells and the toxicity to normal cells are key factors that limit chemotherapy. Here, we used two models of highly resistant lung cancer cells: (1) adherent cells growing under prolonged periods of serum starvation (PPSS) and (2) cells growing as floating tumorspheres (FTs) to evaluate the effect of Verapamil (VP) in combination with Sorafenib (SF). Compared to cells growing under routine culture conditions (RCCs), PPPS cells or FTs were highly sensitive to short-term exposure (24 h) to VP 100 μM + SF 5 μM (VP100 + SF5). Recovery experiments exposing cells to VP100 + SF5 for 24 h followed by incubation in drug-free media for 48 h demonstrated that while PPSS as well as FT cells were unable to recover, cancer cells and the noncancerous cell line Beas-2B growing under RCCs were less sensitive and were also able to recover significantly. VP100 + SF5 induced significant changes in the expression of protein associated with apoptosis, autophagy, and to a lesser extent necroptosis. Coincubation experiments with z-VAD-FMK, necrostatin 1, or chloroquine showed evidence that necroptosis played a central role. Our data demonstrates that highly resistant cancer cells can be selectively eliminated by VP + SF and that necroptosis plays a central role.


1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.


2018 ◽  
Vol 21 (7) ◽  
pp. 462-467
Author(s):  
Babak Sadeghi

Aim and Objective: Ultrafine Ag/ZnO nanotetrapods (AZNTP) have been prepared successfully using silver (I)–bis (oxalato) zinc complex and 1, 3-diaminopropane (DAP) with a phase separation system, and have been injected into a diethyl/water solution. Materials and Methods: This crystal structure and lattice constant of the AZNTP obtained were investigated by means of a SEM, XRD, TEM and UV-vis spectrum. Results: The results of the present study demonstrated the growth and characterization AZNTP for humidity sensing and DAP plays a key role in the determination of particle morphology. AZNTP films with 23 nm in arm diameter have shown highly sensitive, quick response sensor material that works at room temperature.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manit Srisurapanont ◽  
Sirijit Suttajit ◽  
Surinporn Likhitsathian ◽  
Benchalak Maneeton ◽  
Narong Maneeton

AbstractThis study compared weight and cardiometabolic changes after short-term treatment of olanzapine/samidorphan and olanzapine. Eligible criteria for an included trial were ≤ 24 weeks, randomized controlled trials (RCTs) that compared olanzapine/samidorphan and olanzapine treatments in patients/healthy volunteers and reported weight or cardiometabolic outcomes. Three databases were searched on October 31, 2020. Primary outcomes included weight changes and all-cause dropout rates. Standardized mean differences (SMDs) and risk ratios (RRs) were computed and pooled using a random-effect model. This meta-analysis included four RCTs (n = 1195). The heterogeneous data revealed that weight changes were not significantly different between olanzapine/samidorphan and olanzapine groups (4 RCTs, SDM = − 0.19, 95% CI − 0.45 to 0.07, I2 = 75%). The whole-sample, pooled RR of all-cause dropout rates (4 RCTs, RR = 1.02, 95% CI 0.84 to 1.23, I2 = 0%) was not significant different between olanzapine/samidorphan and olanzapine groups. A lower percentage of males and a lower initial body mass index were associated with the greater effect of samidorphan in preventing olanzapine-induced weight gain. Current evidence is insufficient to support the use of samidorphan to prevent olanzapine-induced weight gain and olanzapine-induced cardiometabolic abnormalities. Samidorphan is well accepted by olanzapine-treated patients.


2016 ◽  
Vol 307 ◽  
pp. 137-144 ◽  
Author(s):  
Gaëtan Philippot ◽  
Fred Nyberg ◽  
Torsten Gordh ◽  
Anders Fredriksson ◽  
Henrik Viberg

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