Effect of Omega-3 on Rat Sperm DNA Methylation and Histological Structure of Testis after Treatment with Bleomycin, Etoposide and Cisplatin (BEP)

BACKGROUND AND OBJECTIVE: During the cancer treatment course, in addition to the destructive effects on the tumor cells, chemotherapy also damages healthy tissues and disrupts the balance of oxidant and antioxidant levels. The present study was conducted to evaluate the effect of omega-3 on sperm DNA methylation and histological structure of rat testis after treatment with combination chemotherapy using bleomycin, etoposide and cisplatin (BEP). METHODS: In this experimental study, 40 male rats were randomly divided into four groups of control, BEP, BEP+omega-3 and omega-3 (n=10). The control group was treated with 0.9% normal saline intraperitoneally for 18 weeks. The second group (BEP) first received 0.9% normal saline intraperitoneally for nine weeks. Then, it received BEP at 5.1 mg / kg for nine weeks, received etoposide and cisplatin at 5.7 mg/kg through gavage on days 1-5 of each week, and then received bleomycin at 75 mg/kg on days 2 of each week. The third group was gavaged with 0.9% saline for 9 weeks and then, orally received 300 mg/kg/day omega-3(capsule containing 1000 mg, 18% EPA and 12% DHA) for 9 weeks and in BEP + omega-3 group treated with BEP based on the same method and then orally received 300 mg/kg omega-3 as an antioxidant for the second nine weeks daily. Sperm DNA methylation and histological structure of rat testis including seminiferous tubules and basement membrane thickness were respectively evaluated by immunofluorescence staining and Periodic acid – Schiff (PAS) after 18 weeks of treatment in all groups. FINDINGS: The mean percentage of sperm DNA methylation in the BEP-treated group (52.22±3.11) was significantly decreased compared to the control group (81.80±2.92) (p<0.001). However, the mean percentage of sperm DNA methylation increased significantly with omega-3 use after treatment with BEP (67±2.18) compared with BEP group (p<0.01). In light microscopy of testicular tissue, the number of spermatogonial cells (44.95±1.56), primary spermatocytes (47.60±1.45) as well as the epithelial thickness of seminiferous tubules (145.5±5.64) and basement membrane (7.07±0.29) decreased in the BEP-treated group in comparison with control group (p<0.001). However, the use of omega-3 after treatment with BEP significantly improved the number of germ cells and epithelial thickness of the seminiferous tubule and basement membrane (p<0.01). CONCLUSION: Based on the results of this study, omega-3 as an antioxidant can improve the cytotoxic effects of chemotherapy drugs and it is recommended to be used for cancer patients after chemotherapy to reduce the cytotoxicity of these drugs

Bursts and Isolated Spikes Code for Opposite Movement Directions in Midbrain Electrosensory Neurons

Directional selectivity, in which neurons respond strongly to an object moving in a given direction but weakly or not at all to the same object moving in the opposite direction, is a crucial computation that is thought to provide a neural correlate of motion perception. However, directional selectivity has been traditionally quantified by using the full spike train, which does not take into account particular action potential patterns. We investigated how different action potential patterns, namely bursts (i.e. packets of action potentials followed by quiescence) and isolated spikes, contribute to movement direction coding in a mathematical model of midbrain electrosensory neurons. We found that bursts and isolated spikes could be selectively elicited when the same object moved in opposite directions. In particular, it was possible to find parameter values for which our model neuron did not display directional selectivity when the full spike train was considered but displayed strong directional selectivity when bursts or isolated spikes were instead considered. Further analysis of our model revealed that an intrinsic burst mechanism based on subthreshold T-type calcium channels was not required to observe parameter regimes for which bursts and isolated spikes code for opposite movement directions. However, this burst mechanism enhanced the range of parameter values for which such regimes were observed. Experimental recordings from midbrain neurons confirmed our modeling prediction that bursts and isolated spikes can indeed code for opposite movement directions. Finally, we quantified the performance of a plausible neural circuit and found that it could respond more or less selectively to isolated spikes for a wide range of parameter values when compared with an interspike interval threshold. Our results thus show for the first time that different action potential patterns can differentially encode movement and that traditional measures of directional selectivity need to be revised in such cases

In Vivo Assessment of Cold Adaptation in Insect Larvae by Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy

Background Temperatures below the freezing point of water and the ensuing ice crystal formation pose serious challenges to cell structure and function. Consequently, species living in seasonally cold environments have evolved a multitude of strategies to reorganize their cellular architecture and metabolism, and the underlying mechanisms are crucial to our understanding of life. In multicellular organisms, and poikilotherm animals in particular, our knowledge about these processes is almost exclusively due to invasive studies, thereby limiting the range of conclusions that can be drawn about intact living systems. Methodology Given that non-destructive techniques like 1H Magnetic Resonance (MR) imaging and spectroscopy have proven useful for in vivo investigations of a wide range of biological systems, we aimed at evaluating their potential to observe cold adaptations in living insect larvae. Specifically, we chose two cold-hardy insect species that frequently serve as cryobiological model systems–the freeze-avoiding gall moth Epiblema scudderiana and the freeze-tolerant gall fly Eurosta solidaginis. Results In vivo MR images were acquired from autumn-collected larvae at temperatures between 0°C and about -70°C and at spatial resolutions down to 27 µm. These images revealed three-dimensional (3D) larval anatomy at a level of detail currently not in reach of other in vivo techniques. Furthermore, they allowed visualization of the 3D distribution of the remaining liquid water and of the endogenous cryoprotectants at subzero temperatures, and temperature-weighted images of these distributions could be derived. Finally, individual fat body cells and their nuclei could be identified in intact frozen Eurosta larvae. Conclusions These findings suggest that high resolution MR techniques provide for interesting methodological options in comparative cryobiological investigations, especially in vivo

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Comparison pain relieving effects of glucose and water in neonates

Background: Newborns routinely undergo painful procedures. Several methods have been used to relieve pain in neonates. The objective of this study was to assess the analgesic effect of 50% glucose and water during hepatitis B vaccination.Methods: In this randomized controlled trial, 90 term neonates were studied. Infants were randomly assigned to one of the three equal sized groups. First, heart rates were measured by ECG monitor. Then, 2mL of either 50% glucose or sterile water was administered into the mouth of infants in group one and two, respectively. No intervention was undertaken for group three. During and up to three minutes after the vaccination crying of the babies was recorded. The heart rates were measured during injection until 60 seconds.Findings: The mean values of duration of crying for glucose, water, and no-intervention groups were 21.1 s, 33.3 s, and 56.9 s, respectively, which were significantly different (p=0.0003). Post hoc test revealed substantial differences between group one and three (p=0.0001) and between group two and three (p=0.006). However, groups one and two were not statistically different (p=0.19). Moreover, heart rate did not rise significantly in any of these groups. Conclusion: Both 50% glucose and water showed an analgesic effect in neonates