Different Concentrations Of Dimethyl Sulfoxide Research Articles

Investigation of Excess Thermo‐Acoustic Behavior of Binary Liquid Mixture with Various Temperatures Using Ultrasonic Technique

AbstractUltrasonic methods have been very fruitful in studying the physical properties of binary liquid combinations. In this present study, the thermoacoustic behavior of benzyl propionate with dimethyl sulfoxide (DMSO) is observed using ultrasound, density, and viscosity at different temperatures between 308 and 328 K with a phase of 10 °C. Benzyl propionate is a sweet‐smelling liquid that is used in the botanical and fruit fragrance industries, as well as in the flavoring of organic products. DMSO is a dipolar aprotic, naturally soluble compound used for slow drug synthesis, device synthesis, and drug delivery to the body. Estimated values such as adiabatic compressibility, intermolecular free length, internal pressure, and free volume are determined from arbitrary ultrasonic velocity, density, and viscosity data. The same excess parameters of adiabatic compressibility, intermolecular free length, internal pressure, and free volume support finding the nature of the reaction. The sort of interactions has been accounted for utilizing these qualities. In the present work, benzyl propionate with dimethyl sulfoxide has been characterized by using ultrasonic waves and since this wave is a well‐known tool for NDT, so the mixture is properly characterized. These thermoacoustic parameters with different concentrations of DMSO at different temperatures have been used to study the complex formation and binding through intermolecular forces.

Agrobacterial Transformation Enhancement by Improved Competent Cell Preparation and Optimized Electroporation.

The introduction of plasmids into Agrobacterium cells is one of the key steps in the Agrobacterium-mediated transformation of plants for gene editing applications. Depending on chromosomal background, some Agrobacterium strains exhibit a very low transformation efficiency, which results in a low number of colonies for subsequent screening and thus limits the potential for automated high-throughput transformation processes, especially with low copy or large plasmids. This study demonstrates improvements of transformation frequency by modifying the competent cell preparation process and optimizing electroporation parameters for two Agrobacterium strains. The competent cell preparation process was modified by prolonging bacterial growth in the log phase and optimizing the endpoint cell density for cell harvest which resulted in a significant cell yield increase and transformation frequency improvement. Optimization of electroporation by fine-tuning the parameters not only resulted in a 30-fold transformation frequency increase but also revealed a strain-dependent requirement for field strength and electric pulse length. To further improve transformation of a recalcitrant strain, different concentrations of dimethyl sulfoxide (DMSO) in recovery medium were examined. The study revealed an important role of DMSO in transformed cell recovery, with 5% DMSO resulting in the highest transformation frequency. The significant improvements in Agrobacterium transformation frequency addressed a critical bottleneck towards establishing a high throughput process.

Enhancing the organic solvent resistance of ω-amine transaminase for enantioselective synthesis of (R)-(+)-1(1-naphthyl)-ethylamine.

Biocatalysis in high-concentration organic solvents has been applied to produce various industrial products with many advantages. However, using enzymes in organic solvents often suffers from inactivation or decreased catalytic activity and stability. An R-selective ω-amine transaminase from Aspergillus terreus (AtATA) exhibited activity toward 1-acetylnaphthalene. However, AtATA displayed unsatisfactory organic solvent resistance, which is required to enhance the solubility of the hydrophobic substrate 1-acetylnaphthalene. So, improving the tolerance of enzymes in organic solvents is essential. The method of regional random mutation combined with combinatorial mutation was used to improve the resistance of AtATA in organic solvents. Enzyme surface areas are structural elements that undergo reversible conformational transitions, thus affecting the stability of the enzyme in organic solvents. Herein, three surface areas containing three loops were selected as potential mutation regions. And the "best" mutant T23I/T200K/P260S (M3) was acquired. In different concentrations of dimethyl sulfoxide (DMSO), the catalytic efficiency (kcat /Km ) toward 1-acetylnaphthalene and the stability (half-life t1/2 ) were higher than the wild-type (WT) of AtATA. The results of decreased Root Mean Square Fluctuation (RMSF) values via 20-ns molecular dynamics (MD) simulations under 15%, 25%, 35%, and 45% DMSO revealed that mutant M3 had lower flexibility, acquiring a more stable protein structure and contributing to its organic solvents stability than WT. Furthermore, M3 was applied to convert 1-acetylnaphthalene for synthesizing (R)-(+)-1(1-naphthyl)-ethylamine ((R)-NEA), which was an intermediate of Cinacalcet Hydrochloride for the treatment of secondary hyperthyroidism and hypercalcemia. Moreover, in a 20-mL scale-up experiment, 10mM 1-acetylnaphthalene can be converted to (R)-NEA with 85.2% yield and a strict R-stereoselectivity (enantiomeric excess (e.e.) value>99.5%) within 10h under 25% DMSO. The beneficial mutation sites were identified to tailor AtATA's organic solvents stability via regional random mutation. The "best" mutant T23I/T200K/P260S (M3) holds great potential application for the synthesis of (R)-NEA.

Effect of Extenders Including High Concentrations Dimethyl Sulfoxide (DMSO) on Post-Thaw Rabbit Sperm Parameters

Cryoprotectants have critical roles to prevent cell damages during cryopreservation. However, the adjustment of cryoprotectant concentration is also very crucial to protect cells from cryoprotectant toxicity. The present study was designed to investigate the effect of extenders including high concentration dimethyl sulfoxide (DMSO) on post-thaw rabbit sperm quality. Pooled rabbit sperm samples (n=7) were diluted and cryopreserved in extenders including 250 mmol/L Tris, 88 mmol/L citric acid, 47 mmol/L glucose, 1% sucrose and different concentrations of DMSO. The presence of high concentration DMSO (12 and 14%) in extender decreased sperm total and progressive motility (P < 0.01). The 8 and 10 percent DMSO supplementations in extender increased live sperm rates (P < 0.01). Live and intact acrosome or intact membrane sperm rates were detected higher in 8 and 10 DMSO groups (P < 0.05). When total intact membrane sperm rates were similar in all groups, total intact acrosome sperm rate was higher in 8 DMSO group compared to 12 DMSO group (P < 0.05). In conclusion, when 12 and 14 percent DMSO additions in extender adversely affected post-thaw sperm parameters, the presence of 8 percent DMSO in extender provided the highest post-thaw sperm quality.

EVALUATION OF TWO CRYOPROTECTANTS USED IN A NEW HUMAN SPERM CRYOPRESERVATION TECHNIQUE.

The aim: To examine the efficiency of different concentrations of Dimethyl sulfoxide (DMSO) and glycerol as a cytoprotectants in protection of human sperms during cryopres¬ervation in this technique. Materials and methods: Thirty oligozoospermic semen samples were used in this study. Samples diagnosed according to WHO 2010 criteria. Sheep's ovarian follicles obtained from local slaughterhouse and prepared by slicing the ovaries and evacuating the follicular fluid and oocyte. Each semen sample divided into six equal parts, and diluted 1:1 with cryosolution contains 5%, 10%, 15% DMSO or glycerol and injected within the emptied follicles. After freezing and thawing, the semen mixture aspired outside the follicles and sperm concentration, progressive motility, total motility, and normal morphology were examined. Results: The best recovery rate of progressive and total motility post-thawing were with the use of 5% glycerol, and the lowest recovery rate of progressive and total motility and normal morphology were with the use of 15% DMSO. Conclusions: In this technique, glycerol was more efficient than DMSO regarding sperm motility. The best concentration of glycerol for cryopreserve human spermatozoa is 5%.

Effect of DMSO on lifespan and physiology in C. elegans : Implications for use of DMSO as a solvent for compound delivery.

Dimethyl sulfoxide (DMSO) is a solvent that has been used for basic and medical research based on its ability to dissolve both polar and non-polar compounds. In order to use DMSO to deliver compounds that may impact longevity or neurodegeneration, it is important to first determine the effects of DMSO on aging and physiology. We examined the effect of different concentrations of DMSO on lifespan and development time in C. elegans. We found that DMSO concentrations up to 2% DMSO did not affect longevity in wild-type worms, while concentrations of up to 0.5% DMSO were compatible with normal development times. 0.5% DMSO also had minimal effect on fertility and movement. In summary, our results show that concentrations of DMSO up to 0.5% can be safely used to deliver compounds to C. elegans with little or no modifying effects on lifespan or physiologic rates.

Improvement on the performance of chemically cross-linked fricke methylthymol-blue radiochromic gel dosimeter by addition of dimethyl sulfoxide

The effect of free radical scavenger dimethyl sulfoxide (DMSO) on the performance of transparent Fricke methylthymol blue dye (MTB)-polyvinyl alcohol (PVA)-chemical cross-linking agent glutaraldehyde (GTA) dosimeter (MTB-PVA-GTA) was studied and evaluated using two optical detection methods. By adding different concentrations of DMSO, the properties of the dosimeter were analyzed by ultraviolet–visible (UV–Vis) spectrometry and using 2-D optical imaging system based on a charge-coupled-device (CCD) camera with a diffusing red-light surface. The gel dosimeters were irradiated using 6, 10, and 15 MV photon beams of a medical linear accelerator at various dose rates. Linear absorbance-dose relationships was obtained in the range 0–10 Gy with DMSO ranging from 0 to 3000 mM. No significant changes to the dependence of the response on the dose rate (150, 300, and 600 cGy/min) and the photon energy (6, 10, and 15 MV photon beams) were observed by adding DMSO to the dosimeter. In general, increasing DMSO concentration reduced sensitivity, reduced diffusion coefficient, and enhanced the stability of the dosimeter. The addition of DMSO to the Fricke MTB-PVA-GTA dosimeter showed a good measured sensitivity and a significant low diffusion coefficient when compared with the values measured for other Fricke radiochromic dosimeters reported previously. This improved composition shows a lower diffusion coefficient with respect to those reported so far for a Fricke dosimeter with PVA and gelatin gel. The total uncertainty of the Fricke dosimeter were 4.6%.

Effects of Dimethyl Sulfoxide on the Pluripotency and Differentiation Capacity of Mouse Embryonic Stem Cells.

Mouse embryonic stem cells (mESCs) go through self-renewal in the existence of the cytokine leukemia inhibitory factor (LIF). LIF is added to the mouse stem cells culture medium, and its removal results in fast differentiation. Dimethyl sulfoxide (DMSO) is one of the most used solvents in drug test. We exposed 4-day mESC cultures to different concentrations of DMSO (0.1%, 0.5%, 1.0%, and 2.0%) to identify the safest dose exhibiting efficacy as a solvent. mESCs grown under general pluripotency conditions in the absence of LIF were treated with DMSO. In addition, as a control for differentiation, mESCs were grown in the absence of LIF. DMSO upregulated the mRNA expression level of pluripotency markers. Moreover, DMSO reduced the mRNA expression levels of ectodermal marker (β-tubulin3), mesodermal marker (Hand1), and endodermal markers (Foxa2 and Sox17) in mESCs. These results indicate that DMSO treatment enhances the pluripotency and disrupts the differentiation of mESCs. We also show that members of the Tet oncogene family are critical to inhibiting the differentiation and methylation of mESCs. DMSO is appropriate to sustain the pluripotency of mESCs in the absence of LIF, and that mESCs can be sustained in an undifferentiated state using DMSO. Therefore, DMSO may, in part, function as a substitute for LIF.

The influence of different sample preparation on mechanical properties of human iliotibial tract

In the run-up to biomechanical testing, fresh human tissue samples are often frozen in order to inhibit initial decomposition processes and to achieve a temporal independence of tissue acquisition from biomechanical testing. The aim of this study was to compare the mechanical properties of fresh tissue samples of the human iliotibial tract (IT) to fresh-frozen samples taken from the same IT and those modified with different concentrations of Dimethylsulfoxide (DMSO) prior to freezing. All samples were partial plastinated and destructive tensile tests were conducted with a uniaxial tensile test setup. A plastination technique already established in the laboratory was modified to improve the clamping behaviour of the samples. Material failure was caused by a gradual rupture of the load-bearing collagen fibre bundles. Contrary to our expectations, no significant difference was found between the tensile strength of fresh and fresh frozen specimens. The addition of 1 wt% DMSO did not increase the tensile strength compared to fresh-frozen samples; an addition of 10 wt% DMSO even resulted in a decrease. Based on our findings, the use of simple fresh-frozen specimens to determine the tensile strength is viable; however fresh specimens should be used to generate a complete property profile.

Highly soluble HOPEMP-functionalized phthalocyanines for photodynamic activity: Photophysical, photochemical and aggregation properties

This study presents the synthesis, characterization, photochemical, photophysical and aggregation properties of novel 4-((1,2,2,6,6-pentamethylpiperidin-4-yl)oxy)phthalonitrile (HOPEMP-Pht) and its highly soluble peripherally tetra-substituted Mg(II) (HOPEMP-MgPc), Zn(II) (HOPEMP-ZnPc), and In(III)CI (HOPEMP-InPc) phthalocyanine derivatives as a photosensitizer for photodynamic therapy (PDT) application. The novel compounds were characterized using various techniques. These phthalocyanines exhibit good solubility in many common organic solvents such as dimethyl-formamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, acetone, chloroform, diethyl ether, dichloromethane, ethyl acetate, ethanol, methanol, hexane, and toluene. Aggregation behaviors of the HOPEMP-functionalized phthalocyanines were researched in different concentrations of dimethyl sulfoxide. To evaluate the photodynamic therapy potential of these phthalocyanines, photochemical and photophysical properties were examined in dimethyl sulfoxide for the first time. Besides, the effects of the nature of central metal atom on photochemical and photophysical properties of these phthalocyanines are also stated. As a result; singlet oxygen, photodegradation, fluorescence and aggregation properties show that these phthalocyanines can be promising photosensitizers for PDT studies.

Modeling Direct and Indirect Action on Cell Survival After Photon Irradiation under Normoxia and Hypoxia.

The demand for personalized medicine in radiotherapy has been met by a surge of mechanistic models offering predictions of the biological effect of ionizing radiation under consideration of a growing number of parameters. We present an extension of our existing model of cell survival after photon irradiation to explicitly differentiate between the damage inflicted by the direct and indirect (radicals-mediated) action of ionizing radiation. Within our approach, we assume that the oxygenation status affects the indirect action. The effect of different concentrations of dimethyl sulfoxide (DMSO), an effective radical scavenger, has been simulated at different dose levels in normoxic and hypoxic conditions for various cell lines. Our model is found to accurately predict experimental data available in literature, validating the assumptions made in our approach. The presented extension adds further flexibility to our model and could act as basis for further developments of our model.

Biocatalytic Synthesis of Calycosin-7-O-β-D-Glucoside with Uridine Diphosphate–Glucose Regeneration System

Calycosin-7-O-β-D-glucoside (Cy7G) is one of the principal components of Radix astragali. This isoflavonoid glucoside is regarded as an indicator to assess the quality of R. astragali and exhibits diverse pharmacological activities. In this study, uridine diphosphate-dependent glucosyltransferase (UGT) UGT88E18 was isolated from Glycine max and expressed in Escherichia coli. Recombinant UGT88E18 could selectively and effectively glucosylate the C7 hydroxyl group of calycosin to synthesize Cy7G. A one-pot reaction by coupling UGT88E18 to sucrose synthase (SuSy) from G. max was developed. The UGT88E18–SuSy cascade reaction could recycle the costly uridine diphosphate glucose (UDPG) from cheap sucrose and catalytic amounts of uridine diphosphate (UDP). The important factors for UGT88E18–SuSy cascade reaction, including UGT88E18/SuSy ratios, different temperatures, and pH values, different concentrations of dimethyl sulfoxide (DMSO), UDP, sucrose, and calycosin, were optimized. We produced 10.5 g L−1 Cy7G in the optimal reaction conditions by the stepwise addition of calycosin. The molar conversion of calycosin was 97.5%, with a space–time yield of 747 mg L−1 h−1 and a UDPG recycle of 78 times. The present study provides a new avenue for the efficient and cost-effective semisynthesis of Cy7G and other valuable isoflavonoid glucosides by UGT–SuSy cascade reaction.

Effect of Cryopreservation on Different Passages of Porcine Dorsal Root Ganglion Cell Culture

The cell culture obtained from dorsal root ganglia (DRG) is a valuable model used in biology or medical research. However, the effect of cryopreservation on the properties of DRG-derived cell culture of different passages remains unclear up to date. The objective of the study is to assess the effect of cryopreservation with various concentrations of cryoprotectant dimethyl sulfoxide (DMSO) on the viability and morphological features of porcine neonatal DRG cell culture of different passages. Cell suspension was obtained from DRG of neonatal piglets and cultured in an α-MEM nutritional medium supplemented with 10% fetal calf serum (0, 1st, and 2nd passages). Cells of different passages were cryopreserved at a cooling rate of 0.5°C/min to – 20°C (step 1) and 1°C/min to – 80°C (step 2) followed by immersion into liquid nitrogen. Cryoprotective solutions based on α-MEM nutrient medium and 25% fetal calf serum (FCS) containing 5%, 7.5%, and 10% DMSO were used. It was established that the primary culture (passage 0) consisted of four cell morphological types: large rounded cell bodies of sensory neurons (SN) and three types of non-neuronal cells, namely, polygonal cells with pronounced elongated processes (type 1), spindle-shaped cells (type 2), and multipolar flattened fibroblastoid cells (type 3). As the number of passages increases, an elimination of SN from the culture, a decrease in the relative number of 1st and 2nd cell types, and expansion of 3rd cell type were observed. DRG cell culture had sufficiently high resistance to cryopreservation as cell viability was in the range from 83% to 90% using different concentrations of DMSO. The cells of passage 1 were more resistant to cryopreservation in comparison with primary culture cells (passage 0). The best result was achieved by freezing the culture of passage 1 in the cryoprotective medium with 7.5% DMSO, where 90.6% of viable cells were observed after thawing.

Use of dimethylsulfoxide for semen cryopreservation in Indian red jungle fowl (Gallus gallus murghi)

Glycerol is a least toxic and most effective cryoprotectant for cryopreservation of poultry semen, but due to its contraceptive properties removal of glycerol is usually needed prior to artificial insemination. Dimethylsulfoxide (DMSO), a small amphiphilic molecule used as penetrating cryoprotectant for biological cells, has been recognized as an adequate alternative for cryopreservation of sperm from several species. This study was designed to evaluate the efficacy of different concentrations of DMSO as cryoprotectant for Indian red jungle fowl (Gallus gallus murghi) sperm. Semen was collected from Indian red jungle fowl cocks, pooled and divided into five aliquots. Different concentrations of DMSO (0%, 4%, 6%, 8% and 10%) were compared. Diluted semen was cooled from 37 °C to 4 °C (−0.275 °C min−1), 20% glycerol added to control and equilibrated for 10 min. After equilibration, semen was filled in 0.5 mL French straws, kept over liquid nitrogen vapors for 10 min and plunged into liquid nitrogen. Semen samples were thawed at 37 °C for 30 s. Cryo-survival of Indian red jungle fowl sperm was affected by cryopreservation stages and different concentrations of cryoprotectant used. Highest sperm motility (85.0 ± 2.9; 80.0 ± 3.5; 71.3 ± 4.3; 60.0 ± 1.3), plasma membrane integrity (79.5 ± 3.8; 75.3 ± 2.4; 72.8 ± 3.3; 60.3 ± 2.8), viability (80.8 ± 4.6; 75.5 ± 2.9; 71.0 ± 7.6; 58.8 ± 1.3) and acrosomal integrity (76.3 ± 2.4; 72.0 ± 6.0; 62.5 ± 4.3; 55.0 ± 3.2) were recorded in a diluent having 8% DMSO at post-dilution, cooling, equilibration and freeze-thawing. Highest fertility results were obtained after artificial insemination with 8% DMSO compared to 20% glycerol (73.0 ± 4.4 vs 53.1 ± 4.3, P < 0.05). It is concluded that 8% DMSO as a permeable cryoprotectant improves the post thaw semen quality and fertility in Indian red jungle fowl and can be used effectively to avoid the contraceptive effects of glycerol.

Enhancement of ethanol production by novel morpholinium ionic liquids

Two novel morpholinium ionic liquids, N-allyl-N-methylmorpholinium acetate ([AMMorph][Ac]) and morpholinium acetate ([Morph][Ac]), were synthesized and successfully used for pretreatment of rice straw. While imidazolium liquids are the most efficient solvents for the pretreatment of lignocelluloses, the main advantages of morpholinium liquids are their lower toxicity and price. Different concentrations of dimethyl sulfoxide (DMSO), as an inexpensive industrial co-solvent, were mixed with the synthesized ionic liquids to assist the pretreatment efficiency. The pretreatment was performed at 90, 100, and 120 °C for 2, 3, and 5 h. Then, the pretreated materials were subjected to enzymatic hydrolysis followed by fermentation. Moreover, the efficiency of the synthesized ionic liquids was compared with those of four widely used solvents, i.e., 85% N-methylmorpholine-N-oxide (NMMO), 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]), 8% NaOH solution, and 85% H3PO4 solution. The pretreatment with [AMMorph][Ac] resulted in the significant improvement of enzymatic hydrolysis, which was as efficient as the best widely used pretreatments. The glucose yields of 98.4 ± 1.3% were achieved by pretreatment with mixtures of [AMMorph][Ac]-DMSO as well as NMMO, [Bmim][Ac], and NaOH. The highest ethanol yields of 90.8% and 94.8% were achieved through 70:30 (v/v) [AMMorph][Ac]-DMSO solution and NMMO, respectively. Moreover, using DMSO as a co-solvent could minimize the ionic liquids usage without lowering their performance and enhanced the pretreatment efficiency by viscosity reduction.

The effect of different concentrations of Dimethyl sulfoxide (DMSO) and glycerol as cryoprotectant in preserving Vero cells

Different concentrations of dimethyl sulfoxide (DMSO) and glycerol were used for cryopreservation of Vero cells. After total cell count Vero cells were preserved in liquid nitrogen. Two frozen stocks were made simultaneously from the cell suspensions of same concentrations using DMSO or glycerol at concentrations of 2.5%, 5%, 10% and 15%. After six months of cryopreservation both frozen stocks were used providing same nutrients and environment for the viability of the Vero cells. The cell viability analysis was performed immediately after thawing by Trypan Blue Exclusion Test. Both cryoprotectants showed a protective effect on Vero cells. When Glycerol was used, a maximum cell viability rate of 89.4% and a lowest cell viability rate of 63% were achieved at concentrations of 10% and 2.5%, respectively. On the other hand, DMSO at a concentration of 10% had the highest effect on cryoprotectivity and showed highest cell viability (75%), while at 15% concentration it showed the lowest cell viability (53%). It is suggested that DMSO and glycerol are appropriate protective materials for the cryopreservation of Vero cells. The solutions at concentration of 10% of DMSO and glycerol could be the best choice of cryoprotectant for long-term (6 months) preservation of Vero cells.Bangl. vet. 2016. Vol. 33, No. 1, 1-7

Cryopreservation of human mesenchymal stromal cells expressing TRAIL for human anti-cancer therapy

Background aimsMesenchymal stromal cells (MSCs) are being extensively researched for cell therapy and tissue engineering. We have engineered MSCs to express the pro-apoptotic protein tumor necrosis factor–related apoptosis inducing ligand (TRAIL) and are currently preparing this genetically modified cell therapy for a phase 1/2a clinical trial in patients with metastatic lung cancer. To do this, we need to prepare a cryopreserved allogeneic MSCTRAIL cell bank for further expansion before patient delivery. The effects of cryopreservation on a genetically modified cell therapy product have not been clearly determined. MethodsWe tested different concentrations of dimethyl sulfoxide (DMSO) added to the human serum albumin ZENALB 4.5 and measured post-thaw cell viability, proliferation ability and differentiation characteristics. In addition, we examined the homing ability, TRAIL expression and cancer cell–killing capacities of cryopreserved genetically modified MSCs compared with fresh, continually cultured cells. ResultsWe demonstrated that the post-thaw viability of MSCs in 5% DMSO (v/v) with 95% ZENALB 4.5 (v/v) is 85.7 ± 0.4%, which is comparable to that in conventional freezing media. We show that cryopreservation does not affect the long-term expression of TRAIL and that cryopreserved TRAIL-expressing MSCs exhibit similar levels of homing and, importantly, retain their potency in triggering cancer cell death. ConclusionsThis study shows that cryopreservation is unlikely to affect the therapeutic properties of MSCTRAIL and supports the generation of a cryopreserved master cell bank.

Potential bleaching effects on coral reproduction

Bleaching profoundly impacts coral reproduction, often for years after an event. However, detailed reproductive characteristics of coral after bleaching have not been broadly described, especially as they relate to cryopreservation. Therefore, in the present study we measured several reproductive characteristics in coral in Kaneohe Bay, Hawaii, for two species, namely Fungia scutaria and Montipora capitata, during the bleaching period of 2014 and 2015. We examined spawning periods, egg morphometry, sperm concentration, fresh and cryopreserved sperm motility exposed to different concentrations of dimethyl sulfoxide, time of first cleavage, larval survival with fresh and cryopreserved spermatozoa, infection success and settlement success. Many of these reproductive parameters were reduced in 2015, especially sperm motility. Once the reduced-motility spermatozoa from 2015 post-bleach were cryopreserved, there was a steep decline in post-thaw viability and this would prevent any substantive further use of these samples in reproduction for conservation benefit. Worldwide, as bleaching events become more frequent, the ability to bank and conserve coral ex situ may be significantly reduced. Thus, it is imperative that while genetic diversity is still high in these populations, intensive efforts are made to bank coral species during non-bleaching periods.

Phytotoxicity of dimethyl sulfoxide (DMSO) to rice seedlings

The physiological responses of dimethyl sulfoxide (DMSO) exposure were investigated in rice (Oryza sativa L. cv. XZX 45) seedlings. The seedlings were hydroponically exposed to different concentrations of DMSO for 72 h. Results showed that a linear decrease in relative growth rate and water use efficiency was observed with rice seedlings with increasing DMSO concentrations. The estimation of cell death measured by Evans blue uptake also indicated DMSO-induced damage in root tissues. Negligible decrease in chlorophylls was noted, while significant reduction in carotenoids content was only observed at 13.54 mM DMSO. Although DMSO did not have any significant effect on protein content in roots, the protein content in shoots was significantly decreased in a dose-dependent manner. Proline content in both plant tissues was positively affected by DMSO exposure, responding an inverted U-shaped curve with DMSO concentrations. Results also showed that DMSO-induced accumulation of hydrogen peroxide (H2O2) was evident in roots rather than shoots. DMSO did not result in any significant changes in superoxide dismutase and peroxidase activities as well as malondialdehyde content. Catalase (CAT) activity in both roots and shoots was quite sensitive to changes in DMSO treatments than other enzymes, suggesting that CAT may play central role in the detoxification of H2O2 in rice seedlings under DMSO exposure. Results suggest that growth inhibition and cell death of rice seedlings caused by DMSO exposure were largely related to the accumulation of H2O2 in plant tissues.

Methods of cryopreservation of Tambaqui semen, Colossoma macropomum

This study compared three different techniques for sperm cryopreservation of Tambaqui (Colossoma macropomum). Semen was diluted in Beltsville Thawing Solution with the addition of dimethyl sulfoxide (DMSO) at various concentrations (5%, 10%, 15% and 20%). Cryopreservation was performed using three methods: Box Conditioner Method with straws at a 5cm distance from liquid nitrogen vapor (N2L); Dry Shipper Method placing the straws inside the machine; Vitrification Method placing the straws directly into N2L, amounting to 12 treatments (four DMSO concentrations×three freezing methods). The samples were evaluated for analysis of sperm quality in vivo and in vitro. Use of the Vitrification Method at different concentrations of DMSO provided the least values in the different evaluations. Fertilization, hatching rates and plasma membrane integrity using the Box Conditioner Method with 5% and 10% DMSO did not differ (P>0.05) but use of the concentration of 5% DMSO resulted in greater values than the other treatments (P<0.05) as well as for sperm motility and latency time (P<0.05), although sperm viability was superior using the Dry Shipper Method with 20% of the cryoprotectant. Mitochondrial functionality was impaired by use of the Vitrification Method with all DMSO concentration tested showing the most desirable values when the Box Conditioner Method was used with 5%, 10%, 15% DMSO and the Dry Shipper Method was used with 10% and 15% DMSO. Considering the variables evaluated, the use of the Box Conditioner Method is associated with enhanced Tambaqui semen quality with freeze concentrations of 5% and 10% DMSO.