Inhibiting aberrant p53-PUMA feedback loop activation attenuates ischaemia reperfusion-induced neuroapoptosis and neuroinflammation in rats by downregulating caspase 3 and the NF-κB cytokine pathway.

BACKGROUND: Ischaemia reperfusion (IR) induces multiple pathophysiological changes. In addition to its classical role in regulating tumourigenesis, the feedback loop formed by p53 and its driven target p53-upregulated modulator of apoptosis (PUMA) was recently demonstrated to be the common node tightly controlling various cellular responses during myocardial IR. However, the roles of the p53-PUMA feedback loop in the spinal cord remain unclear. This study aimed to elucidate the roles of p53-PUMA feedback interactions in the spinal cord after IR, specifically investigating their regulation of caspase 3-mediated apoptosis and nuclear factor (NF)-κB-mediated cytokine release. METHODS: SD rats subjected to 12 min of aortic arch occlusion served as IR models. Neurological assessment as well as p53 and PUMA mRNA and protein expression analyses were performed at 12-h intervals during a 48-h reperfusion period. The cellular distributions of p53 and PUMA were determined via double immunofluorescence staining. The effects of the p53-PUMA feedback loop on modulating hind-limb function; the number of TUNEL-positive cells; and protein levels of caspase 3, NF-κB and cytokines interleukin (IL)-1ß and tumour necrosis factor (TNF)-α, were evaluated by intrathecal treatment with PUMA-specific or scramble siRNA and pifithrin (PFT)-α. Blood-spinal cord barrier (BSCB) breakdown was examined by Evans blue (EB) extravasation and water content analyses. RESULTS: IR induced significant behavioural deficits as demonstrated by deceased Tarlov scores, which displayed trends opposite those of PUMA and p53 protein and mRNA expression. Upregulated PUMA and p53 fluorescent labels were widely distributed in neurons, astrocytes and microglia. Injecting si-PUMA and PFT-α exerted significant anti-apoptosis effects as shown by the reduced number of TUNEL-positive cells, nuclear abnormalities and cleaved caspase 3 levels at 48 h post-IR. Additionally, p53 colocalized with NF-κB within the cell. Similarly, injecting si-PUMA and PFT-α exerted anti-inflammatory effects as shown by the decreased NF-κB translocation and release of IL-1ß and TNF-α. Additionally, injecting si-PUMA and PFT-α preserved the BSCB integrity as determined by decreased EB extravasation and spinal water content. However, injecting si-Con did not induce any of the abovementioned effects. CONCLUSIONS: Inhibition of aberrant p53-PUMA feedback loop activation by intrathecal treatment with si-PUMA and PFT-α prevented IR-induced neuroapoptosis, inflammatory responses and BSCB breakdown by inactivating caspase 3-mediated apoptosis and NF-κB-mediated cytokine release.

MicroRNA-125b mimic inhibits ischemia reperfusion-induced neuroinflammation and aberrant p53 apoptotic signalling activation through targeting TP53INP1.

BACKGROUND: Ischemia reperfusion (IR) injury affects neuronal function through multiple pathogeneses that induce neuroinflammation and cellular apoptosis. The important roles of microRNAs (miRs) in the regulation of spinal cord IR have been recently reported. Among these roles, we investigated whether miR-125b and its downstream targets regulated the p53 signalling network and participated in both inflammation and apoptosis. METHODS: An IR model was established via 12-min occlusion of the aortic arch. The direct interaction between miR-125b and TP53INP1 was demonstrated by Western blotting and luciferase assays. The cellular distributions of TP53INP1 were visualised by double immunofluorescence labelling. The effects of miR-125b on the expression of TP53INP1, p53 and release of proinflammatory cytokines were evaluated by synthetic miRs. Additionally, the detection of hind-limb motor function in vivo and motor neuronal apoptosis in vitro were evaluated to explore the potential mechanisms. RESULTS: IR-induced alterations in hind-limb motor function were closely related to the temporal changes in miR-125b and TP53INP1 expression. The miR-125b/TP53INP1 gene pair was confirmed by luciferase assay. Compared with Sham controls, IR treatment resulted in increased TP53INP1 immunoreactivity that was primarily distributed in neurons. Treatment with miR-125b mimic markedly decreased the protein levels of TP53INP1, p53 and cytokines interleukin (IL)-1ß and tumour necrosis factor (TNF)-α, whereas miR-125b control or inhibitor did not have the above-mentioned effects. Moreover, miR-125b mimic improved motor function in vivo and attenuated neuronal apoptosis in vitro, as demonstrated by the increased average Tarlov scores in lower limbs and lower percentages of neurons in the A4 and A2 quadrants of flow cytometry. Fluorescent staining and quantification further indicated that miR-125b mimic decreased the immunoreactivities of p53 and cleaved caspase 3 in neurons and simultaneously reduced the number of double-labelled cells with TP53INP1. CONCLUSIONS: miR-125b mimic partially protected neurons against neuroinflammation and aberrant p53 network activation-induced apoptosis during IR injury through downregulation of TP53INP1.

Preoperative versus postoperative ultrasound-guided rectus sheath block for improving pain, sleep quality and cytokine levels in patients with open midline incisions undergoing transabdominal gynecological surgery: a randomized-controlled trial.

BACKGROUND: Nerve block is usually performed before surgery because it inhibits reflection of the skin incision and reduces the amount of intraoperative anesthetic used. We hypothesized that performing rectus sheath block (RSB) after surgery would result in a longer duration of the analgesic effects and have a subtle influence on sleep time after surgery but that it would not decrease the perioperative cytokine levels of patients undergoing gynecological surgery. METHODS: A randomized, double-blinded, controlled trial was conducted from October 2015 to June 2016. Seventy-seven patients undergoing elective transabdominal gynecological surgery were randomly assigned to the following two groups: a general anesthesia group who received 0.5% ropivacaine hydrochloride RSB preoperatively and saline RSB postoperatively, and another group who received the opposite sequence. The objective of the trial was to evaluate the postoperative pain, sleep and changes in cytokine levels of patients during the postoperative 48 h. RESULTS: A total of 61 female patients (mean age: 50 years; range: 24-65 years) were included in the final study sample. There was no significant difference in the pain, consumption of oxycodone, or time to first administration of patient-controlled intravenous analgesia between the two groups. The postoperative sleep stages N2 and N3 were increased by 52.9 and 29.1 min per patient, respectively, in the preoperative RSB group compared with those in the postoperative group. The preoperative IL-6 concentration in the preoperative RSB group was lower than that in the same group at the end of surgery and 24 h postoperatively. CONCLUSIONS: We concluded that preoperative RSB might preserve postoperative sleep by inhibiting the increase of IL-6 without shortening the analgesia time compared with postoperative RSB in female patients undergoing elective midline incision transabdominal gynecological surgery. TRIAL REGISTRATION: ClinicalTrials.gov , NCT02477098 , registered on 15 June 2015.

Changes in the first postoperative night bispectral index of patients after thyroidectomy with different types of primary anesthetic management: a randomized controlled trial.

Despite major advances in anesthesia management and developments in anesthetic agents, postoperative sleep disturbances remain dissatisfactory for many patients. We hypothesized that propofol might have a subtle influence on sleep after thyroidectomy compared to sevoflurane. A randomized, single-blinded, controlled trial was conducted at the First Hospital of China Medical University from October 2014 to October 2015. One hundred and twenty-four patients undergoing thyroidectomy were enrolled and received sevoflurane (sevoflurane group) or propofol (propofol group) as anesthesia maintenance. Major assessments were made during the operation (different types of anesthetic management) and on the first postoperative night (sleep status). The primary outcome was postoperative sleep status, measured by the BIS-Vista monitor on the first night after surgery between propofol and sevoflurane groups. A total of 105 patients (79 women, 26 men; mean age 49 years; range 18-65 years) were included in the final study sample. All patients in both groups showed one of the five sleep patterns classified by this trial. The BIS-area under the curve was decreased, the sleep efficiency index was significantly increased, and the durations of postoperative sleep and sleep stage N3 were increased by 110.5 and 36.5 min per patient, respectively, in the propofol compared to the sevoflurane group. Propofol might preserve sleep time immediately after thyroidectomy. Clinical Trials.gov identifier: NCT 02146976.

Effects of ultrasound-guided stellate-ganglion block on sleep and regional cerebral oxygen saturation in patients undergoing breast cancer surgery: a randomized, controlled, double-blinded trial.

Numerous factors could contribute to sleep disturbances in women with breast cancer. We hypothesized that stellate ganglion block (SGB) during surgery would preserve sleep after surgery and increase intraoperative regional cerebral oxygen saturation (rSO2) on the blocked side in patients undergoing breast cancer surgery. A randomized, double-blinded, controlled trial was conducted at the First Hospital of China Medical University from January 2016 to September 2016. Ninety-six patients who underwent radical breast cancer surgery requiring general anaesthesia were randomly assigned to one of two study groups: a control group that received a saline SGB and a block group that received a 0.25% ropivacaine hydrochloride SGB. The primary outcome measure was the postoperative sleep profile, which was assessed using the bispectral index on the first postoperative night. The secondary outcome measure was the intraoperative rSO2, monitored was throughout surgery using near-infrared spectroscopy. A total of 91 female patients (mean age: 45 years; range 24-51 years) were included in the study. The duration of sleep was significantly increased by 66.3 min in the ropivacaine-SGB group compared with the saline-SGB group. No differences in rSO2 were observed on either the left or right side of the patients in either group 50 min after anaesthesia induction. We conclude that ropivacaine-SGB combined with general anaesthesia might increase the first postoperative sleep duration without influencing the intraoperative rSO2 in female patients undergoing elective breast cancer surgery. Clinical trials.gov identifier NCT02651519.

Elevated microRNA-129-5p level ameliorates neuroinflammation and blood-spinal cord barrier damage after ischemia-reperfusion by inhibiting HMGB1 and the TLR3-cytokine pathway.

BACKGROUND: Ischemia-reperfusion (IR) affects microRNA (miR) expression and causes substantial inflammation. Multiple roles of the tumor suppressor miR-129-5p in cerebral IR have recently been reported, but its functions in the spinal cord are unclear. Here, we investigated the role of miR-129-5p after spinal cord IR, particularly in regulating high-mobility group box-1 (HMGB1) and the Toll-like receptor (TLR)-3 pathway. METHODS: Ischemia was induced via 5-min occlusion of the aortic arch. The relationship between miR-129-5p and HMGB1 was elucidated via RT-PCR, western blotting, and luciferase assays. The cellular distribution of HMGB1 was determined via double immunofluorescence. The effect of miR-129-5p on the expression of HMGB1, TLR3, and downstream cytokines was evaluated using synthetic miRs, rHMGB1, and the TLR3 agonist Poly(I:C). Blood-spinal cord barrier (BSCB) permeability was examined by measuring Evans blue (EB) dye extravasation and the water content. RESULTS: The temporal miR-129-5p and HMGB1 expression profiles and luciferase assay results indicated that miR-129-5p targeted HMGB1. Compared with the Sham group, the IR group had higher HMGB1 immunoreactivity, which was primarily distributed in neurons and microglia. Intrathecal injection of the miR-129-5p mimic significantly decreased the HMGB1, TLR3, interleukin (IL)-1ß and tumor necrosis factor (TNF)-α levels and the double-labeled cell count 48 h post-surgery, whereas rHMGB1 and Poly(I:C) reversed these effects. Injection of miR-129-5p mimic preserved motor function and prevented BSCB leakage based on increased Basso Mouse Scale scores and decreased EB extravasation and water content, whereas injection rHMGB1 and Poly(I:C) aggravated these injuries. CONCLUSIONS: Increasing miR-129-5p levels protect against IR by ameliorating inflammation-induced neuronal and BCSB damage by inhibiting HMGB1 and TLR3-associated cytokines.

miR-320a affects spinal cord edema through negatively regulating aquaporin-1 of blood-spinal cord barrier during bimodal stage after ischemia reperfusion injury in rats.

BACKGROUND: Spinal cord edema is a serious complication and pathophysiological change after ischemia reperfusion (IR) injury. It has been demonstrated closely associated with bimodal disruption of blood-spinal cord barrier (BSCB) in our previous work. Aquaporin (AQP)1 plays important but contradictory roles in water homeostasis. Recently, microRNAs (miRs) effectively regulate numerous target mRNAs during ischemia. However, whether miRs are able to protect against dimodal disruption of BSCB by regulating perivascular AQP1 remains to be elucidated. RESULTS: Spinal water content and EB extravasation were suggested as a bimodal distribution in directly proportion to AQP1, since all maximal changes were detected at 12 and 48 h after reperfusion. Further TEM and double immunofluorescence showed that former disruption of BSCB at 12 h was attributed to cytotoxic edema by up-regulated AQP1 expressions in astrocytes, whereas the latter at 48 h was mixed with vasogenic edema with both endothelial cells and astrocytes involvement. Microarray analysis revealed that at 12 h post-injury, ten miRs were upregulated (>2.0 fold) and seven miRs were downregulated (<0.5 fold) and at 48 h, ten miRs were upregulated and eleven were downregulated compared to Sham-operated controls. Genomic screening and luciferase assays identified that miR-320a was a potential modulator of AQP1 in spinal cord after IR in vitro. In vivo, compared to rats in IR and negative control group, intrathecal infusion of miR-320a mimic attenuated IR-induced lower limb motor function deficits and BSCB dysfunction as decreased EB extravasation and spinal water content through down-regulating AQP1 expressions, whereas pretreated with miR-320a AMO reversed above effects. CONCLUSION: These findings indicate miR-320a directly and functionally affects spinal cord edema through negatively regulating AQP1 of BSCB after IR.

Changes in postoperative night bispectral index of patients undergoing thoracic surgery with different types of anaesthesia management: a randomized controlled trial.

This study hypothesized that different types of anaesthesia management would result in similar postoperative sleep quality. In this prospective single-blind investigation, 219 patients undergoing elective thoracic surgery were randomized into three arms: general anaesthesia, as the control group (group C); general anaesthesia combined with thoracic epidural anaesthesia (TEA) (group E); and general anaesthesia combined with infusion of 1 µg/kg dexmedetomidine (group D). Plasma samples were obtained to measure the amine and inflammatory cytokine concentrations. All patients underwent assessment with the bispectral index (BIS) for sleep quality and the visual analogue scale (VAS) for pain. The primary outcomes were inflammatory cytokine [interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α)] secretion and postoperative sleep quality on the first and second postoperative nights. The secondary outcomes were amine (adrenaline and noradrenaline) secretion during the surgical period and haemodynamic stability. The postoperative BIS area under the curve was significantly lower in group E (75.7%) than in group C (87.3%) or group D (86.5%). Patients in group E had the highest BIS of sleep efficiency index (29.2%, P < 0.05) and the lowest VAS scores (3.5, P < 0.05). Group E had lower IL-6 levels than the other two groups 24 h after surgery (P < 0.05). Patients given TEA may show reduced sleep disturbances on the first night after surgery, perhaps due to better pain management and inhibition of IL-6 release.

Dexmedetomidine attenuates blood-spinal cord barrier disruption induced by spinal cord ischemia reperfusion injury in rats.

BACKGROUND/AIMS: Dexmedetomidine has beneficial effects on ischemia reperfusion (I/R) injury to the spinal cord, but the underlying mechanisms are not fully understood. This study investigated the effects and possible mechanisms of dexmedetomidine on blood-spinal cord barrier (BSCB) disruption induced by spinal cord I/R injury. METHODS: Rats were intrathecally pretreated with dexmedetomidine or PBS control 30 minutes before undergoing 14-minute occlusion of aortic arch. Hind-limb motor function was assessed using Tarlov criteria, and motor neurons in the ventral gray matter were counted by histological examination. The permeability of the BSCB was examined using Evans blue (EB) as a vascular tracer. The spinal cord edema was evaluated using the wet-dry method. The expression and localization of matrix metalloproteinase-9 (MMP-9), Angiopoietin-1 (Ang1) and Tie2 were assessed by western blot, real-time polymerase chain reaction, and immunofluorescence. RESULTS: Intrathecal preconditioning with dexmedetomidine minimized the neuromotor dysfunction and histopathological deficits, and attenuated EB extravasation after spinal cord I/R injury. In addition, dexmedetomidine preconditioning suppressed I/R-induced increase in MMP-9. Finally, Dexmedetomidine preconditioning enhanced the Ang1-Tie2 system activity after spinal cord I/R injury. CONCLUSIONS: Dexmedetomidine preconditioning stabilized the BSCB integrity against spinal cord I/R injury by inhibition of MMP-9, and enhancing the Ang1-Tie2 system.

MiR-27a ameliorates inflammatory damage to the blood-spinal cord barrier after spinal cord ischemia: reperfusion injury in rats by downregulating TICAM-2 of the TLR4 signaling pathway.

BACKGROUND: Spinal cord ischemia reperfusion (IR) injury causes inflammation and subsequently increases blood-spinal cord barrier leakage and Toll-like receptor 4 (TLR4) pathway activation. MicroRNAs (miRs) effectively regulate numerous target mRNAs during ischemia. However, their roles during IR injury are poorly understood. We investigated miRs involvement, particularly miR-27a, in TLR4 pathway-mediated inflammatory responses after IR. METHOD: We used a genomics approach to examine changed miRs of rats that had undergone 14 minutes of ischemia, followed by 24 or 72 hours of reperfusion. Quantitative RT-PCR was used to identify and confirm the miRs involved in regulating TLR4 pathway activation. We scanned miR databases for potential miR targets and confirmed these targets by quantitative RT-PCR. The miR mimic and anti-miR oligonucleotides (AMOs) were intrathecally injected at 12-hour intervals beginning three days before the ischemia. The effects of miRs on the TLR4 pathway and downstream cytokines were analyzed by PCR, western blotting, and ELISA. Double immunofluorescence staining was perfumed to determine the relationship between the targets and TLR4. Blood-spinal cord barrier (BSCB) permeability was examined using Evans blue (EB) dye. RESULTS: A microarray analysis revealed that at 24 hours post-injury, three miRs were upregulated (>2.0 fold) and 15 miRs were downregulated (<0.5 fold), and at 72 hours, four miRs were upregulated and 14 were downregulated compared to their levels in sham-operated controls. We focused on miR-27a, which is predicted to contain sequences complementary to the 3'-untranslated region (UTR) of Toll-like receptor adaptor molecule 2 (TICAM-2). Double immunostaining indicated that TLR4 activation correlated with changes in TICAM-2 expression. Compared to the rats in the IR and negative control groups, intrathecal infusion of the miR-27a mimic attenuated IR-induced TLR4 activation and inflammatory damage to the BSCB, which was shown as decreased EB extravasation and lower levels of nuclear factor kappa-B (NF-κB) and lnterleukin (IL)-1ß at 24 and 72 hours after reperfusion, whereas pretreatment with miR-27a AMO aggravated these injuries. CONCLUSIONS: We present the first evidence that miRs play an important role in spinal cord IR injury. We identified TICAM-2 as a novel target of miR-27a. miR-27a upregulation attenuates IR-induced inflammatory damage to the BSCB by negatively regulating TICAM-2 of the TLR4 signaling pathway and inhibiting the NF-κB/IL-1ß pathway. These results provide new therapeutic targets for IR injury treatment.

The effects of thoracic epidural analgesia on oxygenation and pulmonary shunt fraction during one-lung ventilation: an meta-analysis.

BACKGROUND: The aim of our study is to compare the effects of thoracic epidural analgesia combined with general anesthesia (GA) vs. general anesthesia on oxygenation and pulmonary shunt fraction during one-lung ventilation (OLV). METHODS: Literature research was firstly conducted for studies related to comparison of epidural anesthesia combined with GA vs. GA with reporting of hemodynamic and oxygenation variables and published from Jan 1990 to Jan 2014 in EMBAS, MEDLINE and Cochrane Central Register of Controlled Trials databases. The studies were reviewed and data were extracted and analyzed using fixed-effect and random-effect models. RESULTS: There are 14 trials with 60 separate comparisons enrolling 653 patients for analysis. Regarding systemic hemodynamics, thoracic epidural analgesia decreased the mean arterial pressure and mean pulmonary arterial pressure with weighted mean difference 95% confidence interval (-6.64 [-9.57 to -3.71] vs. -6.33 [-9.25 to -3.41] and -3.18 [-5.07 to -1.28] vs. -2.05 [-3.35 to -0.75]) respectively at the two measurements time, however, only decreasing heart rate and systemic vascular resistance (-3.28 [-5.98 to -0.67] and -319.99 [-447.05 to -192.94]) over the first 30 min after OLV. For oxygenation variables, thoracic epidural analgesia is associated with significant reduction in partial arterial oxygen pressure, mixed arterial saturation of oxygenation and increased pulmonary venous admixture fraction compared to general anesthesia with weighted mean difference 95% confidence interval (-16.52 [-21.98 to - 11.05] vs. - 14.23 [-20.81 to - 7.65]), (0.74 [0.33 to 1.15] vs. - 0.63 [-1.23 to -0.04]) and (2.53 [1.35 to 3.72] vs. 2.77 [1.81 to 3.74]) respectively before and after 30 min of one-lung ventilation. A decrease in mixed venous saturation of oxygenation occurred after 30 min of OLV (-2.39 [-3.73 to -0.99]). Besides, a higher mean value of airway pressure was found in the thoracic epidural analgesia with weighted mean difference 95% confidence interval (1.95 [1.61 to 2.28] vs. 0.87 [0.54 to 1.20]) at the measurements. CONCLUSION: Based on the existing limited data puts forward recommendations for cautious usage of thoracic epidural analgesia in case of underlying risks in lower systemic hemodynamics, decreased partial arterial oxygen pressure but increases pulmonary shunt during one-lung ventilation.

Role of the TLR4 pathway in blood-spinal cord barrier dysfunction during the bimodal stage after ischemia/reperfusion injury in rats.

BACKGROUND: Spinal cord ischemia-reperfusion (I/R) involves two-phase injury, including an initial acute ischemic insult and subsequent inflammatory reperfusion injury, resulting in blood-spinal cord barrier (BSCB) dysfunction involving the TLR4 pathway. However, the correlation between TLR4/MyD88-dependent and TLR4/TRIF-dependent pathways in BSCB dysfunction is not fully understood. The aim of this study is to characterize inflammatory responses in spinal cord I/R and the events that define its clinical progression with delayed neurological deficits, supporting a bimodal mechanism of injury. METHODS: Rats were intrathecally pretreated with TAK-242, MyD88 inhibitory peptide, or Resveratrol at a 12 h interval for 3 days before undergoing 14-minute occlusion of aortic arch. Evan's Blue (EB) extravasation and water content were detected at 6, 12, 18, 24, 36, 48, and 72 h after reperfusion. EB extravasation, water content, and NF-κB activation were increased with time after reperfusion, suggesting a bimodal distribution, as maximal increasing were detected at both 12 and 48 h after reperfusion. The changes were directly proportional to TLR4 levels determined by Western blot. Double-labeled immunohistochemical analysis was also used to detect the relationship between different cell types of BSCB with TLR4. Furthermore, NF-κB and IL-1ß were analyzed at 12 and 48 h to identify the correlation between MyD88-dependent and TRIF-dependent pathways. RESULTS: Rats without functional TLR4 and MyD88 attenuated BSCB leakage and inflammatory responses at 12 h, suggesting the ischemic event was largely mediated by MyD88-dependent pathway. Similar protective effects observed in rats with depleted TLR4, MyD88, and TRIF receptor at 48 h infer that the ongoing inflammation which occurred in late phase was mainly initiated by TRIF-dependent pathway and such inflammatory response could be further amplified by MyD88-dependent pathway. Additionally, microglia appeared to play a major role in early phase of inflammation after I/R injury, while in late responding phase both microglia and astrocytes were necessary. CONCLUSIONS: These findings indicate the relevance of TLR4/MyD88-dependent and TLR4/TRIF-dependent pathways in bimodal phases of inflammatory responses after I/R injury, corresponding with the clinical progression of injury and delayed onset of symptoms. The clinical usage of TLR4 signaling inhibitors at different phases may be a therapeutic option for the prevention of delayed injury.

Intrathecal transplantation of bone marrow stromal cells attenuates blood-spinal cord barrier disruption induced by spinal cord ischemia-reperfusion injury in rabbits.

OBJECTIVE: Intrathecal administration of bone marrow stromal cells has been found to produce beneficial effects on ischemia-reperfusion injury to the spinal cord. The blood-spinal cord barrier is critical to maintain spinal cord homeostasis and neurologic function. However, the effects of bone marrow stromal cells on the blood-spinal cord barrier after spinal cord ischemia-reperfusion injury are not well understood. This study investigated the effects and possible mechanisms of bone marrow stromal cells on blood-spinal cord barrier disruption induced by spinal cord ischemia-reperfusion injury. METHODS: This was a prospective animal study conducted at the Central Laboratory of the First Affiliated Hospital, China Medical University. The study used 81 Japanese white rabbits (weight, 1.8-2.6 kg). Spinal cord ischemia-reperfusion injury was induced in rabbits by infrarenal aortic occlusion for 30 minutes. Two days before the injury was induced, bone marrow stromal cells (1 × 10(8) in 0.2-mL phosphate-buffered saline) were transplanted by intrathecal injection. Hind-limb motor function was assessed using Tarlov criteria, and motor neurons in the ventral gray matter were counted by histologic examination. The permeability of the blood-spinal cord barrier was examined using Evans blue (EB) and lanthanum nitrate as vascular tracers. The expression and localization of tight junction protein occludin were assessed by Western blot, real-time polymerase chain reaction, and immunofluorescence analysis. Matrix metalloproteinase-9 (MMP-9) and tumor necrosis factor-α (TNF-α) expression were also measured. RESULTS: Intrathecal transplantation of bone marrow stromal cells minimized the neuromotor dysfunction and histopathologic deficits (P < .01) and attenuated EB extravasation at 4 hours (5.41 ± 0.40 vs 7.94 ± 0.36 µg/g; P < .01) and 24 hours (9.03 ± 0.44 vs 15.77 ± 0.89 µg/g; P < .01) after spinal cord ischemia-reperfusion injury. In addition, bone marrow stromal cells treatment suppressed spinal cord ischemia-reperfusion injury-induced decreases in occludin (P < .01). Finally, bone marrow stromal cells reduced the excessive expression of MMP-9 and TNF-α (P < .01). CONCLUSIONS: Pre-emptive intrathecal transplantation of bone marrow stromal cells stabilized the blood-spinal cord barrier integrity after spinal cord ischemia-reperfusion injury in a rabbit model of transient aortic occlusion. This beneficial effect was partly mediated by inhibition of MMP-9 and TNF-α and represents a potential therapeutic approach to mitigating spinal cord injury after aortic occlusion. CLINICAL RELEVANCE: Clinical thoracoabdominal aorta surgery may trigger spinal cord ischemia-reperfusion injury, resulting in paraplegia as well as bladder, bowel, and sexual dysfunction. Transplantation of bone marrow stromal cells has attracted increasing attention in the field of nervous system protection, but its mechanisms have not been elucidated completely. The blood-spinal cord barrier plays a crucial role to maintain normal spinal cord function. This study suggested that intrathecal transplantation of bone marrow stromal cells stabilized blood-spinal cord barrier integrity through inhibiting the upregulation of matrix metalloproteinase-9 and tumor necrosis factor-a and ameliorated spinal cord ischemia-reperfusion injury. This may provide a novel train of thought to enhance the protective effects of bone marrow stromal cells on spinal cord injury.

Fatal pulmonary embolism in a patient with thromboembolism of the internal jugular vein after liver transplant.

A patient with acute liver failure and thromboembolism of the internal jugular vein subsequently had a massive pulmonary embolism and died 25 days after orthotopic liver transplant. The primary cause of death was massive pulmonary embolus. This case report highlights the need for clinicians to be aware that fatal embolic events can occur in liver transplant recipients, even when routine prophylactic procedures are implemented. The benefits and risks of invasive strategies, including placement of superior vena cava filters, should be considered on a case-by-case basis.