Effects of taurine, cysteine and melatonin as antioxidant supplements to the freezing medium of Prochilodus brevis sperm

Cryopreservation consist of a set of methods to preserve cells and tissues by drastically reducing the temperature. Among some undesired effects, cryopreservation might generate reactive oxygen species that lead to an increase of oxidative stress, causing damage to cells. This study aimed to test taurine, cysteine, and melatonin on the freezing of Prochilodus brevis sperm and assess its effects on post-thawed sperm quality. Sperm was collected and seven pools were formed (n = 7). They were diluted (1:9) in standard medium (5% glucose, 10% dimethyl sulfoxide and 5% egg yolk) supplemented or not (control) with taurine (0.3, 1.0, 3.16 or 10.0 mM), cysteine (0.3, 1.0, 3.16 or 10.0 mM) or melatonin (0.6, 1.12, 2.0 or 3.56 mM). Post-thawed sperm was evaluated for kinetic (total motility, velocities, and percentage of rapid cells), morphology and membrane and DNA integrity. Differences were found when melatonin was used as an antioxidant. For the variables rapid sperm and sperm velocities, 3.56 mM melatonin presented higher results than the control (melatonin 0 mM). Melatonin 2 mM was similar to 3.56 mM on rapid sperm, average path velocity (VAP) and curvilinear velocity (VCL). No difference was found between concentration 0 mM (control) and taurine treatments. As for cysteine, 0.3 mM presented the best results for rapid sperm than 10 mM, and higher VCL and VAP than 1 mM. Melatonin 3.56 mM presented higher results on kinetic parameters (rapid motility, VCL, VSL and VAP) than other tested antioxidants. Therefore, melatonin 3.56 mM is recommended to be added to the sperm freezing medium of P. brevis.

Sulfated polysaccharides from seaweed as a supplement to Prochilodus brevis sperm freezing medium

BACKGROUND

Using sulfated polysaccharides (SP) in fish sperm freezing medium promotes cell maintenance.

OBJECTIVE

To evaluate the effect of different SP concentrations, extracted from two seaweeds (Gracilaria domingensis and Ulva fasciata), as a supplement to the sperm freezing medium of Prochilodus brevis.

MATERIALS AND METHODS

Five semen pools were diluted in a solution composed of 5% glucose, 10 % dimethyl sulfoxide (DMSO) and different SP concentrations (0, 0.5, 1.0, 1.5, 2.0, 2.5 or 3.0 mg/mL). The samples were cryopreserved and, after 7 days, rewarmed and analyzed for morphology, plasma membrane integrity, DNA integrity, mitochondrial activity and sperm kinetics [total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), and wobble (WOB)].

RESULTS

There was no interaction between seaweed and SP concentrations. Similar effects were observed with SP extracted from the two seaweeds, regardless of concentration. When comparing the SP concentrations, regardless of the seaweed, 1.0 mg/mL SP showed better results for VCL and VSL. For VAP and WOB, 1.0 mg/mL SP showed better results, but differed from 3.0 mg/mL. LIN followed the same pattern, but differed from SP at 2.5 and 3.0 mg/mL. For progressive motility, 1.0 mg/mL G. domingensis showed superior results compared to the control. For mitochondrial activity, G. domingensis was superior to U. fasciata, regardless of concentration. The lowest concentrations (0.5 and 1.0 mg/mL) showed the best results, regardless of the seaweed. However, the control was superior to all treatments tested.

CONCLUSION

G. domingensis SP at the lowest concentrations might be a potential supplement to the P. brevis freezing medium. doi.org/10.54680/fr22210110412.

Sperm cryopreservation of Prochilodus brevis using different concentrations of non-permeable cryoprotectants

The action of substances with non-permeable cryoprotectant potential, besides glucose, has not yet been studied for the species Prochilodus brevis. The objective of this work was to evaluate the action of four non-permeable cryoprotectants on this species sperm cryopreservation. Five pools were cryopreserved in a solution of 5% glucose and 10% dimethyl sulfoxide (Me₂SO) associated or not (control) with cryoprotectants egg yolk (5, 10 or 12%), soy lecithin (2.5, 7.5 or 10%), sucrose (5, 10 or 20%) and lactose (5, 8 or 15%). After thawing, samples were evaluated for sperm kinetics (total motility, motility duration, velocities, and wobble - WOB), morphology and membrane and DNA integrity. The treatments containing egg yolk improved significantly (P<0.05) results when compared the control for the membrane integrity parameter. When compared to other treatments, egg yolk, at any concentration, presented higher results (P<0.05) for membrane integrity, total motility, curvilinear velocity (VCL) and average path velocity (VAP) parameters. Egg yolk also showed the best results for WOB, but it did not differ from 5% and 8% lactose and 5% and 20% sucrose. Soy lecithin had the lowest percentages of morphologically normal sperm (P<0.05), while the other treatments did not differ from each other. There was no difference regarding DNA integrity data. Thus, 5% egg yolk is indicated as a non-permeable cryoprotectant for P. brevis, in association with 5% glucose and 10% Me₂SO.

The effect of glycosaminoglycans, extracted from the skin of tilapia, in the sperm freezing medium of Colossoma macropomum

BACKGROUND

Sulfated polysaccharides from the skin of Nile tilapia (Oreochromis niloticus), added to the tambaqui (Colossoma macropomum) semen diluting medium, can be potential antioxidants and promote the maintenance of sperm quality.

OBJECTIVE

To evaluate the use of different concentrations of glycosaminoglycans (GAGs) from the skin of Nile tilapia as a supplement in two cryogenic media for tambaqui semen.

MATERIALS AND METHODS

Tambaqui males received a single dose of pituitary carp extract. The semen was collected for pool analysis and, later, cryopreserved in liquid nitrogen. The pools were diluted and frozen in a solution containing fish-specific powdered coconut water (ACP-104) and 10% DMSO or 5% Glucose and 10% DMSO and supplemented with different concentrations of GAGs. The controls had no GAGs addition. After 45 days, the samples were thawed by immersion in a water bath and evaluated for membrane and DNA integrity, morphology and sperm kinetics.

RESULTS

The parameters of linearity (LIN), straightness (STR) and DNA integrity of sperm frozen in 5% Glucose showed better results than ACP-104. For membrane integrity, concentrations of 0 and 1.0 mg/mL were better than 5 mg/mL. Semen motility in 5% Glucose showed superior results at concentrations lower than 5 mg/mL of GAGs. For VCL and VAP, in ACP-104, 3.0 mg/mL exceeded the other treatments. In 5% Glucose, for VCL, 4.0 mg/mL showed the lowest results compared to concentrations of <3.5 mg/mL and, for VAP, it also differed from 4.5 mg/mL CONCLUSION: Therefore, the skin of Nile tilapia has GAGs, in low concentrations, capable of improving the post-thawed sperm quality of tambaqui, especially in 5% Glucose medium.

Identification, characterisation and molecular modelling of two AP endonucleases from base excision repair pathway in sugarcane provide insights on the early evolution of green plants

Unlike bacteria and mammals, plant DNA repair pathways are not well characterised, especially in monocots. The understanding of these processes in the plant cell is of major importance, since they may be directly involved in plant acclimation and adaptation to stressful environments. Hence, two sugarcane ESTs were identified as homologues of AP endonuclease from the base-excision repair pathway: ScARP1 and ScARP3. In order to understand their probable function and evolutionary origin, structural and phylogenetic studies were performed using bioinformatics approaches. The two predicted proteins present a considerable amino acid sequence similarity, and molecular modelling procedures indicate that both are functional, since the main structural motifs remain conserved. However, inspection of the sort signal regions on the full-length cDNAs indicated that these proteins have a distinct organelle target. Furthermore, variances in their promoter cis-element motifs were also found. Although the mRNA expression pattern was similar, there were significant differences in their expression levels. Taken together, these data raise the hypothesis that the ScARP is an example of a probable gene duplication event that occurred before monocotyledon/dicotyledon segregation, followed by a sub-functionalisation event in the Poaceae, leading to new intracellular targeting and different expression levels.

Resource utilisation and cost of ankylosing spondylitis in Brazil

OBJECTIVES

The present study describes resource utilisation in patients with ankylosing spondylitis (AS) treated at a tertiary public health facility over a one-year period. It also investigates the direct and indirect costs for society associated with the treatment of AS.

METHODS

Ninety AS patients were selected consecutively, and data was analysed retrospectively for one year. Resource utilisation was evaluated through systematic interviews with all patients. Demographic, socioeconomic, and clinical variables were recorded, and questionnaires evaluating quality of life, function, and disease activity were also applied (ASQoL, SF-36, HAQ-S, BASFI, and BASDAI). Estimates of indirect costs were performed using the human-capital approach based on the society perspective.

RESULTS

Most of the patients were men (79%), with a mean age and disease duration of 40 and 16 years, respectively. The mean HAQ-S, BASFI and BASDAI scores were 1, 5, and 4, respectively. The mean ASQoL score for the sample was 8, and the mean Short-Form-36 scores were between 48 (body pain and general health) and 81 (emotional role). The average monthly household income for the group was US$ 520. The patients had an average of 6 outpatient visits, 6 physical therapy visits and 30 laboratory exams per patient, per year. The average total cost for society was US$ 4,597 per patient per year, of which 45% were direct costs and 55% were indirect costs.

CONCLUSIONS

Ankylosing spondylitis is a disease that represents a considerable burden to Brazil. It is extremely important to carry out studies that assess the costs of chronic diseases, especially in developing nations, in order to determine the best manner of allocating the already scanty resources in such regions.