Characterisation of the methylation pattern in the intragenic CpG island of the IGF2 gene in Bos taurus indicus cumulus cells during in vitro maturation

Purpose

The aim of this study was to characterise the methylation pattern in a CpG island of the IGF2 gene in cumulus cells from 1–3 mm and  ≥ 8.0 mm follicles and to evaluate the effects of in vitro maturation on this pattern.

Methods

Genomic DNA was treatment with sodium bisulphite. Nested PCR using bisulphite-treated DNA was performed, and DNA methylation patterns have been characterised.

Results

There were no differences in the methylation pattern among groups (P > 0.05). Cells of pre-IVM and post-IVM from small follicles showed methylation levels of 78.17 ± 14.11 % and 82.93±5.86 %, respectively, and those from large follicles showed methylation levels of 81.81 ± 10.40 % and 79.64 ± 13.04 %, respectively. Evaluating only the effect of in vitro maturation, cells of pre-IVM and post-IVM COCs showed methylation levels of 80.17 ± 12.01 % and 81.19 ± 10.15 %.

Conclusions

In conclusion, the methylation levels of the cumulus cells of all groups were higher than that expected from the imprinted pattern of somatic cells. As the cumulus cells from the pre-IVM follicles were not subjected to any in vitro manipulation, the hypermethylated pattern that was observed may be the actual physiological methylation pattern for this particular locus in these cells. Due the importance of DNA methylation in oogenesis, and to be a non-invasive method for determining oocyte quality, the identification of new epigenetic markers in cumulus cells has great potential to be used to support reproductive biotechniques in humans and other mammals.     

Impact of shock and fluid resuscitation on the morphology and apoptosis of bone marrow: an experimental study

BACKGROUND: We hypothesized that bone marrow failure after hemorrhagic shock might be secondary to impaired apoptosis regulation. Our objective was to assess the morphologic alterations and the rate of apoptosis in bone marrow after hemorrhagic shock and resuscitation. METHODS: Under pentobarbital anesthesia, Wistar rats (n = 70) underwent femoral vessel cannulation. The hemorrhagic shock model involved a controlled retrieval of blood, maintaining mean blood pressure at 40 +/- 5 mm Hg during 50 minutes. During the resuscitation period, lactated Ringer's (twice the blood volume retrieved, group LR) or NaCl 7.5% (4 mL/kg, group HS) was infused, followed by the previously retrieved blood. Bone marrow was collected through left femoral puncture. Morphology was assessed by Leishmann-stained smears, and apoptosis was assessed through terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay. Analysis of variance and Tukey's test were applied for statistical treatment, considering p < 0.05 as significant. RESULTS: LR animals presented a statistically significant decrease in the lymphocytic series (LR, 24.2 +/- 4.2%; Sham, 55.1 +/- 6.6%), together with an increase in the percentage of granulocyte (LR, 51.4% +/- 2.3%; Sham, 31.5 +/- 2.9%) and monocyte precursors (LR, 7.3 +/- 1.3%; Sham, 3.3 +/- 1.1%), detected 72 hours after shock (p < 0.05). Both LR and HS groups presented a significant increase in apoptosis, when compared with the sham group (LR, 13.1 +/- 0.5%; HS, 12.2 +/- 0.7%; Sham, 6.8 +/- 0.4%). The alterations detected in the bone marrow morphology of LR group were not observed in HS animals. CONCLUSION: There was an increase in bone marrow apoptosis after hemorrhagic shock. The type of resuscitation scheme used did influence bone marrow morphology.     

Are lumbar multifidus fatigue and transversus abdominis activation similar in patients with lumbar disc herniation and healthy controls? A case control study

Purpose

The aims of this study were to assess lumbar multifidus fatigue (LM) and transversus abdominis activation (TrA) in individuals with lumbar disc herniation associated with low back pain.

Methods

Sixty individuals were divided into the lumbar herniation (LHG, n = 30) and control groups (CG, n = 30). Fatigue of the LM was assessed using surface electromyography during the Sorensen effort test, and activation of the TrA with a pressure biofeedback unit. Pain intensity was determined using a visual analog scale and the McGill pain questionnaire. The Oswestry disability questionnaire and the Borg scale for self-evaluating exertion were used to assess functional disability.

Results

Fatigue was significantly more intense and the TrA activation was insufficient (p < 0.01) in individuals with disc herniation relative to the control group. The LHG had mild functional disability and moderate pain. There were differences in the initial exertion self-evaluation between groups, which were not observed in the final exertion evaluation.

Conclusion

Individuals with lumbar disc herniation associated with low back pain have increased fatigue of the LM and decreased activation of the TrA, when compared to the control group.