Pubertal exposure to Microcystin-LR arrests spermatogonia proliferation by inducing DSB and inhibiting SIRT6 dependent DNA repair in vivo and in vitro.

The reproduction toxicity of pubertal exposure to Microcystin-LR (MC-LR) and the underlying mechanism needs to be further investigated. In the current study, pubertal male ICR mice were intraperitoneally injected with 2 µg/kg MC-LR for four weeks. Pubertal exposure to MC-LR decreased epididymal sperm concentration and blocked spermatogonia proliferation. In-vitro studies found MC-LR inhibited cell proliferation of GC-1 cells and arrested cell cycle in G2/M phase. Mechanistically, MC-LR exposure evoked excessive reactive oxygen species (ROS) and induced DNA double-strand break in GC-1 cells. Besides, MC-LR inhibited DNA repair by reducing PolyADP-ribosylation (PARylation) activity of PARP1. Further study found MC-LR caused proteasomal degradation of SIRT6, a monoADP-ribosylation enzyme which is essential for PARP1 PARylation activity, due to destruction of SIRT6-USP10 interaction. Additionally, MG132 pretreatment alleviated MC-LR-induced SIRT6 degradation and promoted DNA repair, leading to the restoration of cell proliferation inhibition. Correspondingly, N-Acetylcysteine (NAC) pre-treatment mitigated the disturbed SIRT6-USP10 interaction and SIRT6 degradation, causing recovered DNA repair and subsequently restoration of cell proliferation inhibition in MC-LR treated GC-1 cells. Together, pubertal exposure to MC-LR induced spermatogonia cell cycle arrest and sperm count reduction by oxidative DNA damage and simultaneous SIRT6-mediated DNA repair failing. This study reports the effect of pubertal exposure to MC-LR on spermatogenesis and complex mechanism how MC-LR induces spermatogonia cell proliferation inhibition.

1-Nitropyrene disrupts testicular steroidogenesis via oxidative stress-evoked PERK-eIF2α pathway.

Our previous study showed 1-Nitropyrene (1-NP) exposure disrupted testicular testosterone synthesis in mouse, but the exact mechanism needs further investigation. The present research found 4-phenylbutyric acid (4-PBA), an endoplasmic reticulum (ER) stress inhibitor, recovered 1-NP-induced ER stress and testosterone synthases reduction in TM3 cells. GSK2606414, a protein kinase-like ER kinase (PERK) kinase inhibitor, attenuated 1-NP-induced PERK-eukaryotic translation initiation factor 2α (eIF2α) signaling activation and downregulation of steroidogenic proteins in TM3 cells. Both 4-PBA and GSK2606414 attenuated 1-NP-induced steroidogenesis disruption in TM3 cells. Further studies used N-Acetyl-L-cysteine (NAC) as a classical antioxidant to explore whether oxidative stress-activated ER stress mediated 1-NP-induced testosterone synthases reduction and steroidogenesis disruption in TM3 cells and mouse testes. The results showed NAC pretreatment mitigated oxidative stress, and subsequently attenuated ER stress, particularly PERK-eIF2α signaling activation, and downregulation of testosterone synthases in 1-NP-treated TM3 cells. More importantly, NAC extenuated 1-NP-induced testosterone synthesis in vitro and in vivo. The current work indicated that oxidative stress-caused ER stress, particularly PERK-eIF2α pathway activation, mediates 1-NP-downregulated steroidogenic proteins and steroidogenesis disruption in TM3 cells and mouse testes. Significantly, the current study provides a theoretical basis and demonstrates the experimental evidence for the potential application of antioxidant, such as NAC, in public health prevention, particularly in 1-NP-induced endocrine disorder.

Efficacy of Single-shot Thoracic Paravertebral Block Combined with Intravenous Analgesia Versus Continuous Thoracic Epidural Analgesia for Chronic Pain After Thoracotomy.

BACKGROUND: Patients undergoing thoracic surgery frequently suffer from chronic pain after thoracotomy. Chronic pain can lead to a significant decline in a patient's quality of life. However, the effect of single-shot thoracic paravertebral block (TPVB) combined with intravenous analgesia on chronic pain incidence is unclear. OBJECTIVE: The objective was to evaluate the impact of single-shot TPVB combined with intravenous analgesia versus continuous thoracic epidural analgesia (TEA) on chronic pain incidence after thoracotomy. STUDY DESIGN: A randomized controlled study. SETTING: Hospital department in China. METHODS: Ninety-six patients undergoing thoracotomy were randomly assigned to 2 groups: single-shot TPVB combined with intravenous analgesia (Group P) and continuous TEA (Group E). The pain intensity was assessed using the Verbal Rating Scale (VRS). The outcome measures were chronic pain incidence and the acute and chronic pain intensity. RESULTS: The chronic pain incidence at rest in Group P was significantly higher than that in Group E at 3 months and 12 months postoperation  (55.2% versus 28.6%, P = 0.019; 34.5% versus 14.3%, P = 0.027). The patients in Group E showed less pain intensity at rest compared with those in Group P at 3 months postoperation (0.0 versus 1.0, P = 0.034). At 6 hours and 24 hours postoperation, the acute pain intensity at coughing and at rest in Group E was lower than that in group P (VRS at coughing: 6 hours: 0.0 versus 2.0, P = 0.001; 24 hours: 3.0 versus 5.0, P = 0.010. VRS at rest: 6 hours: 0.0 versus 2.0, P = 0.000; 24 hours: 1.0versus. 2.0, P = 0.001). LIMITATIONS: An important limitation of this study is that it is not a double-blind study. CONCLUSIONS: In patients undergoing thoracotomy, continuous TEA significantly reduced the chronic pain incidence at rest at 3 months and 12 months after operation and provided better acute pain relief up to 24 hours after operation compared with single-shot TPVB combined with intravenous analgesia.

Blockade of Erythropoietin-Producing Human Hepatocellular Carcinoma Receptor B1 in Spinal Dorsal Horn Alleviates Visceral Pain in Rats.

Objective: This experiment was designed to determine whether erythropoietin-producing human hepatocellular carcinoma (Eph) receptors were involved in the development of visceral pain. Methods: Adult male Sprague-Dawley rats were randomly divided into three groups receiving different treatments (n = 16 per group): intracolonic vehicle (control group), intracolonic 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) (TNBS group), and intracolonic TNBS and intrathecal EphB1 receptor blocking reagent (TNBS + EphB2-Fc group). Visceral hyperalgesia was evaluated with quantification of visceral pain threshold induced by colorectal distention. The spinal expressions of EphB1 and ephrinB2 and levels of their phosphorylated forms (p-EphB1 and p-ephrinB2) were assessed by Western blotting and immunohistochemistry. Results: The TNBS-treated rats developed significant visceral hyperalgesia. The spinal expressions of EphB1, p-EphB1, ephrinB2, and p-ephrinB2 were significantly increased in the TNBS group compared with the control group, but visceral hyperalgesia and elevation of spinal EphB1 and p-EphB1 expressions were evidently alleviated by intrathecal administration of EphB2-Fc in the TNBS + EphB2-Fc group. The number of EphB1- and p-EphB1-immunopositive cells, the average optical (AO) value of EphB1, and its phosphorylated form in the spinal dorsal horn were significantly increased in the TNBS group than in the control group, but they were obviously reduced by intrathecal administration of EphB2-Fc. There were no significant differences in the number of ephrinB2- and p-ephrinB2-immunopositive cells and the AO value of ephrinB2 and its phosphorylated form between the TNBS and TNBS + EphB2-Fc groups. Conclusion: EphB1 receptors in the spinal dorsal horn play a pivotal role in the development of visceral pain and may be considered as a potential target for the treatment of visceral pain.

Comparison of tracheal intubation with controlled ventilation and laryngeal mask airway with spontaneous ventilation for thoracoscopic bullectomy.

General anesthesia with double-lumen endobronchial intubation is considered mandatory for thoracoscopic bullectomy. We assessed the safety and feasibility of thoracoscopic bullectomy for treatment of primary spontaneous pneumothorax (PSP) under intubating laryngeal mask airway (ILMA) with spontaneous breathing sevoflurane anesthesia combined with thoracic paravertebral block (TPB).From January 2018 to December 2018, some 34 consecutive patients with PSP were treated by thoracoscopic bullectomy under ILMA with spontaneous breathing sevoflurane anesthesia combined with TPB (study group). To evaluate the safety and feasibility of this new technique, these patients were compared with the control group consisting of 34 consecutive patients with PSP who underwent thoracoscopic bullectomy using tracheal intubation with controlled ventilation from January 2017 to December 2017. The demographic characteristics, intraoperative surgical and anesthetic results, and postoperative results were assessed.The 2 groups had comparable anesthetic time, operation time, chest drainage time, postoperative hospital stays, and hospitalization cost. Visual analogue score (VAS) scores at 3 hours at rest and at coughing were significantly lower in the study group than in the control group (mean, 0.9 vs 2.0 and 1.8 vs 4.0, P = .024 and P = .006, respectively). No differences were seen in PaO2 values between the 2 groups in the intraoperative stage and postoperative stage (P > .05, respectively). The pH value was significantly lower in the intraoperative stage (mean, 7.28 vs 7.40, P = .01) and higher in the postoperative stage (mean, 7.35 vs 7.33, P = .014) in the study group than in the control group. The PaCO2 value was significantly higher in the intraoperative stage in the study group than in the control group (mean, 57.0 mm Hg vs 42.0 mm Hg, P = .015). In the study group, no cough reflex was found, and the level of collapse of the operative lung was excellent in 31 cases and good in 3 cases.Our study demonstrated that thoracoscopic bullectomy for treatment of PSP can be safely and feasibly performed in highly selected patients under ILMA with spontaneous breathing sevoflurane anesthesia combined with TPB.

The effects of preoperative single-dose thoracic paravertebral block on acute and chronic pain after thoracotomy: A randomized, controlled, double-blind trial.

BACKGROUND: Patients undergoing thoracotomy frequently experience acute pain and chronic post-thoracotomy pain (CPTP). There are few articles relating to the investigations on the effects of preoperative single-dose thoracic paravertebral block (PSTPVB) on acute pain and CPTP. We tested the hypothesis that adding PSTPVB to intravenous (IV) patient-controlled analgesia (PCA) would reduce acute pain scores and decrease the incidence and intensity of CPTP. METHODS: Fifty-six patients undergoing elective thoracotomy were randomized to receive PSTPVB in addition to IV PCA (group T) or IV PCA alone (group C). A single 20-mL injection of 0.50% ropivacaine plus 10 mg dexamethasone in saline was administered preoperatively under ultrasound guidance; sufentanil was used for IV PCA. The acute pain intensity at rest and at coughing based on verbal rating scale, postoperative sufentanil consumption, and complications were evaluated at 6, 24, 48, and 72 hours after surgery. The incidence and intensity of CPTP were evaluated at 3 months after surgery. RESULTS: Group T had significantly less acute pain compared with group C at all measurement times both at rest and at coughing (P < .05). The PCA cumulative sufentanil consumption, complications, and the incidence of CPTP between the 2 groups was not statistically significant (P > .05). The intensity of CPTP was significantly higher in group C than in group T (P < .05). CONCLUSION: This study indicated that adding PSTPVB to IV PCA improved acute postoperative pain and chronic pain in patients undergoing thoracotomy, but did not reduce the incidence of CPTP.

Oxygen carrying capacity of salvaged blood in patients undergoing off-pump coronary artery bypass grafting surgery: a prospective observational study.

BACKGROUND: Intraoperative cell salvage (ICS), hereby referred to 'mechanical red cell salvage', has been widely used and proven to be an effective way to reduce or avoid the need for allogeneic red blood cells (RBCs)transfusion and its associated complications in surgeries involving major blood loss. However, little is known about the influence of this technique on the functional state of salvaged RBCs. Furthermore, there are no articles that describe the change of free hemoglobin (fHb) in salvage blood during storage, which is a key index of the quality control of salvaged blood. Therefore, in this study, the influence of ICS on the function of salvaged RBCs and the changes of salvaged RBCs during storage were studied with respect to the presence of oxyhemoglobin affinity (recorded as a P50 value) and the level of 2, 3-diphosphoglycerate (2, 3-DPG) and fHb by comparing salvaged RBCs with self-venous RBCs and 2-week-old packed RBCs. METHODS: Fifteen patients undergoing off-pump coronary artery bypass grafting (OPCAB) surgery were enrolled. Blood was collected and processed using a Dideco Electa device. The level of P50, 2, 3-DPG and fHB from salvaged RBCs, venous RBCs and 2-week-old packed RBCs was measured. We also measured the changes of these indicators among salvaged RBCs at 4 h (storage at 21-24 °C) and at 24 h (storage at 1-6 °C). RESULTS: The P50 value of salvaged RBCs at 0 h (28.77 ± 0.27 mmHg) was significantly higher than the value of venous RBCs (27.07 ± 0.23 mmHg, p=0.000) and the value of the 2-week-old packed RBCs (16.26 ± 0.62 mmHg, p=0.000). P50 value did not change obviously at 4 h (p=0.121) and 24 h (p=0.384) compared with the value at 0 h. The 2, 3-DPG value of salvaged RBCs at 0 h (17.94 ± 6.91 µmol/g Hb) was significantly higher than the value of venous RBCs (12.73 ± 6.52 mmHg, p = 0.007) and the value of the 2-week-old packed RBCs (2.62 ± 3.13 mmHg, p=0.000). The level of 2, 3-DPG slightly decreased at 4 h (p=0.380) and 24 h (p=0.425) compared with the value at 0 h. Percentage of hemolysis of the salvaged blood at 0 h(0.51 ± 0.27 %) was significantly higher than the level of venous blood (0.07 ± 0.05 %, p=0.000) and the value of 2-week-old packed RBCs (0.07 ± 0.05 %, p=0.000), and reached 1.11 ± 0.42 % at 4 h (p=0.002) and 1.83 ± 0.77 % at 24 h (p=0.000). CONCLUSIONS: The oxygen transport function of salvaged RBCs at 0 h was not influenced by the cell salvage process and was better than that of the venous RBCs and 2-week-old packed RBCs. At the end of storage, the oxygen transport function of salvaged RBCs did not change obviously, but percentage of hemolysis significantly increased.