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Necroptosis, a form of regulated necrosis, might be a potential mechanism of delayed paraplegia; therefore, its role in transient spinal cord ischaemia was investigated by immunohistochemical analysis of necroptosis related protein receptor interacting protein kinase (RIP) 1, RIP3, and cellular inhibitor of apoptosis protein (cIAP) 1/2.This study used rabbit normothermic (n = 24) and hypothermic (n = 24) transient spinal cord ischaemia models and sham controls (n = 6). Neurological function was assessed according to a modified Tarlov score at 8 h, 1, 2, and 7 days after reperfusion (n = 6 each). Morphological changes in the spinal cord were examined using haematoxylin and eosin staining in the sham, 2, and 7 day groups. Western blot and histochemical analyses of RIP1, RIP3, and cIAP1/2, and double label fluorescent immunocytochemical studies of RIP3 and cIAP1/2 were performed at 8 h, 1, and 2 days after reperfusion (n = 6 each).There were significant differences in neurological function between the normothermic and hypothermic groups (median scores 0 and 5 at 7 days, p = .023). In the normothermic group, most motor neurons were lost seven days after reperfusion (p = .046 compared with sham), but they were preserved in the hypothermic group. Western blot analysis revealed the upregulation of RIP1, RIP3, and cIAP1/2 at 8 h in the normothermic group (RIP1, p = .032; RIP3, p .001; cIAP1/2, p = .041 compared with sham), and the overexpression of RIP3 was prolonged for two days. In the hypothermic group, the expression of these proteins was not observed. The double label fluorescent immunocytochemical study revealed the induction of RIP3 and cIAP1/2 in the same motor neurons.These data suggest that transient normothermic ischaemia induces necroptosis, a potential factor in delayed motor neuron death, and that hypothermia may inhibit necroptosis.

Compared to the early stage (2011-2012) after the Great East Japan Earthquake, no significant changes were seen in the total number of case of tuberculosis (TB), and pulmonary TB cases in the mid-term stage (2013-2014). However, the number of patients with latent tuberculosis infection (LTBI) decreased significantly in the coastal region of Northern Miyagi, which was ravaged by a post-quake tsunami. We analyzed the data of all TB patients in this region in the early (2011- 2012) and the late (2015- 2016) stages following the Great East Japan Earthquake and compared it with the pre-disaster data. The number of cases of total TB, extra pulmonary TB and LTBI significantly in comparison to the initial stage after the disaster decreased, but there was a significantly higher prevalence of TB and the LTBI compared to pre-disaster. These results suggest that continued health activities and an improved transportation system reduced the prevalence of total TB after the Great East Japan Earthquake. Thus, these health activities should be maintained.

During the early stage (2011-2012) after the Great East Japan Earthquake, the total number of tuberculosis (TB), pulmonary TB and latent tuberculosis infection (LTBI) patients significantly increased only in the coastal region of northern Miyagi, which was ravaged by a post-quake tsunami. Here, we investigated the midterm-stage follow-up (2013-2014) of TB infection in this region. Although the number of total TB, pulmonary TB, and LTBI cases had significantly decreased, their prevalence had not returned to the levels recorded in the pre-disaster period. These results suggest that the influence of the Great East Japan Earthquake remains. Thus, we believe that it is necessary to continue strict monitoring of TB in the coastal region of northern Miyagi.

On March 11, 2011, the Great East Japan Earthquake struck off the northeast coast of Japan. Within an hour of the earthquake, devastating tsunamis swept over the coastal region of the Miyagi Prefecture, facing Pacific Ocean. Accordingly, more than 400,000 residents were forced to stay at evacuation shelters. We investigated the changes in tuberculosis prevalence after the disaster. Annual data for all tuberculosis patients between April 1, 2009 and March 31, 2013 were extracted from the database of the Miyagi Prefectural Government. In the coastal region of Northern Miyagi, the number of tuberculosis patients increased in the post-disaster period (p < 0.001, 9.6 vs.19.1 per 100,000 people), compared to the pre-disaster period. In contrast, its prevalence did not change in the inland region of Northern Miyagi and the coastal and inland regions of Southern Miyagi. Importantly, in the inland and coastal regions of Northern Miyagi, the number of patients with latent tuberculosis infection (LTBI) increased in the post-disaster period (p < 0.001). Furthermore, in the coastal shelters, 11 evacuees with the history of contacting tuberculosis patients were diagnosed with LTBI, whereas no cases of LTBI patients were observed in the inland shelters. Thus, staying in the coastal shelters was a risk factor for contracting tuberculosis (OR: 19.31, 95% CI: 1.11-334.80); indeed, twice as many evacuees visited each coastal shelter on April 1, 2011, compared to the inland region. We should prepare the shelters to avoid overcrowding, and long-term observation is required to detect the prevalence of tuberculosis infection.

Postoperative atrial fibrillation is the most common complication after coronary artery bypass grafting (CABG). This complication is associated with prolongation of the intensive care unit stay and hospitalization time with attendant increased hospitalization costs, and it is an important risk factor for perioperative cerebrovascular accidents. Landiolol is a newly developed ultrashort-acting beta-adrenoceptor antagonist with a half-life of 3 min that is eight times more cardioselective than esmolol. The purpose of this study was to investigate the prophylactic effect of continuous administration of low-dose landiolol on postoperative atrial fibrillation.We reviewed all patients who underwent CABG alone at our hospital from April 2002 and September 2006. Patients with a previous history of atrial arrhythmias were excluded. The remaining patients were divided to two groups: landiolol group (n = 20), and control group (n = 35). Administration of landiolol started after cardiopulmonary bypass with a loading dose of 1.5-2.5 mug.kg(t-1).min(-1) and continued for the first 2 days after surgery. The incidence of postoperative atrial fibrillation was noted. Continuous variables were compared between groups by means of Student's t-test. Categorical variables were compared by means of the chi(2) test or Fisher's exact test.The occurrence of atrial fibrillation after CABG in the control group was statistically more than in the landiolol group (P = 0.04). There were no statistical differences between the groups regarding the cardiac index or the dose of inotropic agents during the perioperative period.Intraoperative and perioperative administration of low-dose landiolol has a preventive effect on the appearance of atrial fibrillation after CABG surgery.

CD44 on macrophages is recognized as a phagocytic receptor involved in the phagocytosis of apoptotic cells. Recently, we detected CD44 on macrophages in atretic follicles during atresia. In this study, we evaluated the distribution of the principal CD44 ligand hyaluronan (HA) and the expressions of HA synthases (HAS: HAS1, HAS2, and HAS3) during atresia in pig ovaries. We determined the 2139-bp sequence of Sus scrofa HAS1 and raised an anti-HAS1 polyclonal antibody. The S. scrofa HAS1 sequence contained six putative HA-binding motifs and conserved amino acid residues crucial for GlcNac transferase activity. HAS1 mRNA expression was upregulated during atresia; however, HAS2 and HAS3 mRNA expression levels were low and very low to undetectable, respectively. Western blotting showed that HAS1 was markedly upregulated during atresia. Immunohistochemical analyses revealed HAS1 distribution in theca cells of healthy and early atretic (stages I and II) follicles and in progressing atretic (stage III) follicles. Hyaluronan was visualized with the HA-binding protein; it accumulated in the theca layer during all stages and in stage III follicles. Hyaluronan assay showed a significantly increased HA concentration in follicular fluid at stage III. Flow cytometry showed HAS1 expression in 55.7% of SIRPA-positive macrophages in stage III follicles. Our results suggest that the HA concentration in follicular fluids increased during atresia and that HAS1 may be the dominant HAS protein in theca cells to produce HA in pig ovaries.

Background and Purpose— Vulnerability of motor neurons in the spinal cord against ischemia is considered to play an important role in the development of delayed paraplegia after surgery of the thoracic aorta. However, the reasons for such vulnerability are not fully understood. Recently, the ubiquitin system has been reported to participate in neuronal cell death. In the present study, we investigated the expression of ubiquitin system molecules and discussed the relationship between the vulnerability and the ubiquitin system after transient ischemia in the spinal cord. Methods— Fifteen minutes of spinal cord ischemia in rabbits was applied with the use of a balloon catheter. In this model, the spinal motor neuron shows selectively delayed neuronal death, whereas other spinal neurons such as interneurons survive. Immunohistochemical analysis and Western blotting for ubiquitin system molecules, ubiquitin, deubiquitylating enzyme (ubiquitin carboxy-terminal hydrolase 1), and ubiquitin-ligase parkin were examined. Results— In cytoplasm, ubiquitin and ubiquitin carboxy-terminal hydrolase 1were strongly induced both in interneuron and motor neuron at the early stage of reperfusion, but the sustained expression was observed only in motor neuron. Parkin was induced strongly at 3 hours after the reperfusion, but the immunoreactivity returned to the sham control level at 6 hours in both neurons. In the nuclei, ubiquitin, ubiquitin carboxy-terminal hydrolase 1, and parkin were strongly induced in interneuron, whereas no upregulation of these proteins was observed in motor neuron. Conclusions— These results indicate that the vulnerability of motor neuron of the spinal cord might be partially attributed to the different response in ubiquitin-mediated stress response after transient ischemia.

Background Delayed paraplegia after operation of the thoracic aorta is considered to be related to vulnerability of motor neurons to ischemia. Recently, endoplasmic reticulum (ER) stress has been reported to participate in neuronal cell death. In the present study, we investigate the expression of ER stress-related molecules and discuss the relationship between neuronal vulnerability and ER stress after transient ischemia in the spinal cord. Methods A rabbit spinal cord ischemia model was generated using a balloon catheter. In this model, spinal motor neurons show selectively delayed neuronal death whereas other spinal neuron, such as interneurons, survive. Immunohistochemical analysis and Western blotting for ER stress-related molecules, including phosphorylated eukaryotic initiation factor 2 alpha (p-eIF2α), activating transcription factor 4 (ATF4), glucose-regulated protein 78 (GRP78) and inositol-requiring ER transmembrane RNAse α isoform (IRE1α), were examined. Results P-eIF2α, which inhibits protein synthesis and modulates ER stress, was induced only in interneurons after 6 h of reperfusion. ATF4, which is specifically activated by PERK-eIF2α, was induced only in interneurons between 6 h and 1 day after reperfusion. GRP78 was induced strongly both in interneurons and motor neurons at an early stage of reperfusion, but prolonged expression was observed only in interneurons. IRE1α, which is supposed to transduce an ER stress-related death signal, was expressed more strongly and over a more prolonged period in motor neurons. Conclusions These results indicate that the vulnerability of motor neurons in the spinal cord might be partially attributed to an ER stress response to transient ischemia.

Objective The mechanism of spinal cord injury is believed to be related to the vulnerability of spinal motor neuron cells to ischemia. The aim of this study was to investigate whether ONO-5046, a specific inhibitor of neutrophil elastase that can attenuate tissue or organ injury in various pathologic conditions, could protect against ischemic spinal cord damage. Methods After induction of spinal ischemia, ONO-5046 or vehicle was injected intravenously. Cell damage was analyzed by counting the number of motor neurons. To investigate the mechanism by which ONO-5046 prevents ischemic spinal cord damage, we observed the immunoreactivity of CPP32 (caspase3), brain-derived neurotrophic factor, and phosphorylated extracellular signal–regulated kinase. Results ONO-5046 eased the functional deficits and increased the number of motor neurons after ischemia. The induction of caspase3 was significantly reduced by ONO-5046 treatment. Furthermore, the expressions of brain-derived neurotrophic factor and phosphorylated extracellular signal–regulated kinase were prolonged. Conclusion ONO-5046 may protect motor neurons from ischemic injury by reducing caspase3 and prolonging the expressions of brain-derived neurotrophic factor and phosphorylated extracellular signal–regulated kinase. ONO-5046 may be a strong candidate for use as a therapeutic agent in the treatment of ischemic spinal cord injury.

Background Paraplegia is a serious complication of operations on the thoracic and thoracoabdominal aorta. To investigate the mechanism by which motor neurons are damaged during these operations, we have reported a rabbit model of spinal cord ischemia. We also tested whether a free radical scavenger MCI-186 that is useful for treating ischemic damage in the brain can protect against ischemic spinal cord damage. Methods Fifteen minutes of ischemia was induced, then MCI-186 or vehicle was injected intravenously. Cell damage was analyzed by observing the function of the lower limbs and by counting the number of motor neurons. To investigate the mechanism by which MCI-186 prevents ischemic spinal cord damage, we observed the immunoreactivity of 8-hydroxy-2'-deoxyguanosine as an oxidative DNA damage marker and redox effector as a DNA repair marker. Results In sham control, 8-hydroxy-2'-deoxyguanosine was not observed, and the nuclear expression of redox effector was observed. In vehicle injection group (group I), the nuclear expression of 8-hydroxy-2'-deoxyguanosine was observed at 1 and 2 days after reperfusion. The nuclear expression of redox effector was observed at 8 hours and 1 day, and disappeared at 2 days after transient ischemia. In MCI-186 injection group (group M), the nuclear expression of 8-hydroxy-2'-deoxyguanosine was not observed, and redox effector was observed at 8 hours and 1 and 2 days. Conclusions These results suggest that redox effector decreased in motor neurons after transient ischemia and this reduction preceded oxidative DNA damage. MCI-186 works as a radical scavenger and reduced oxidative DNA damage, so redox effector did not disappear. MCI-186 could be a strong candidate for a use as a therapeutic agent in the treatment of ischemic spinal cord injury.

Objective The mechanism of spinal cord injury is believed to be related to the vulnerability of spinal motor neuron cells against ischemia. We tested whether MCI-186, which is useful for treating ischemic damage in the brain, can protect against ischemic spinal cord damage. Methods After induction of ischemia, MCI-186 or vehicle was injected intravenously. Cell damage was analyzed by observing the function of the lower limbs and by counting the number of motor neurons. To investigate the mechanism by which MCI-186 prevents ischemic spinal cord damage, we observed the immunoreactivity of Cu/Zn superoxide dismutase, neuronal nitric oxide synthase, and endothelial nitric oxide synthase. Results MCI-186 eased the functional deficits and increased the number of motor neurons after ischemia. The induction of neuronal nitric oxide synthase was significantly reduced by the treatment with MCI-186. Furthermore, the increase in the induction of endothelial nitric oxide synthase and Cu/Zn superoxide dismutase was more pronounced. Conclusion These results indicate that MCI-186 may protect motor neurons from ischemic injury by reducing neuronal nitric oxide synthase and increasing endothelial nitric oxide synthase. MCI-186 may be a strong candidate for use as a therapeutic agent in the treatment of ischemic spinal cord injury.

Spinal cord ischemia has varied etiologies, and in some cases, may develop into paraplegia. This is attributable to the vulnerability of spinal motor neurons to ischemia. We evaluated the potential of the immunosuppressant cyclosporin A for treatment of spinal motor neuron damage caused by ischemia.Twenty-eight rabbits were randomized into four groups of 7 animals each: group A (cyclosporin A not administered), group B (2.5 mg/kg cyclosporin A), group C (25 mg/kg cyclosporin A), and group S (sham-operated). The spinal cord ischemia model was created by a 15-minute occlusion of the aorta just caudal to a renal artery with a balloon catheter. Administration of cyclosporin A began 30 minutes after restoration of blood flow. The spinal cords were removed after 7-day monitoring of neurologic function. Pathology specimens were prepared, and after staining them with hematoxylin-eosin, viable motor neurons in the ventral spinal cord were counted under light microscopy.At 7 days after reperfusion, recovery of motor function was seen at varying degrees in groups B and C, whereas all animals in group A continued to exhibit paraplegia. In group C, most of the animals recovered to the baseline level, before creation of the ischemia model. A significant difference in numbers of viable neurons was found in group A (cell count, 10.1 +/- 4.7) and group C (cell count, 22.2 +/- 8.0) (p0.05). Higher numbers of viable motor neurons corresponded to a greater recovery of motor function.These results suggest that cyclosporin A administration is effective against neuronal damage caused by spinal cord ischemia.

Hypothermia has some protective effect against ischemia of the spinal cord in thoracoabdominal aneurysm repair. Its method is divided into systemic or regional cooling. Several experimental studies of the regional cooling of the spinal cord have been performed, however, clinical reports are few. The purpose of this study is to evaluate the effect and safety of perfusion cooling of the epidural space during thoracic or thoracoabdominal aortic replacement.Between January 1998 to June 2001 37 patients (True aneurysm: 18 patients, type B aortic dissection: 19 patients) underwent thoracic or thoracoabdominal aortic replacement with an aid of epidural perfusion cooling. The age ranged from 23 to 78 years old with a mean age of 61 years old. Separate perfusion of upper and lower body was used in all cases. Temperature was lowered to around a 31 degrees C or 32 degrees C. In cases where proximal cross-clamping was danger, deep hypothermic circulatory arrest was used.Ten patients underwent most or all of descending thoracic aneurysm repair with no spinal cord injury and hospital death. Number of patients of the Crawford type I, type II, and type III were 14, 8 and 5 patients, respectively. One Crawford type II patients was complicated with postoperative spinal cord injury (2.7%). There was one hospital death (2.7%) in Crawford type III. The mean epidural cooling time was 150 minutes, and mean infusion volume of cold saline was 981 cc. The mean lowest cerebrospinal fluid (CSF) temperature was 24.3 degrees C, and mean temperature differences between nasopharynx and CSF was 6.3 degrees C.Perfusion cooling of the epidural space during most or all of the descending thoracic or thoracoabdominal aneurysm repair was effective in reducing postoperative spinal cord injury and a safe method in clinical situations.

The mechanism of spinal cord injury has been thought to be related with tissue ischemia, and spinal motor neuron cells are suggested to be vulnerable to ischemia. To evaluate the mechanism of such vulnerability of motor neurons, we attempted to make a reproducible model of rabbit spinal cord ischemia. Using this model, the inductions of phosphatidylinositol 3-kinase (PI3-k) and serine-threonine kinase (Akt) were investigated with immunohistochemical analyses for up to 7 days of the reperfusion following 15 min of ischemia in rabbit spinal cord. It has been demonstrated that both PI3-k and its downstream effector, Akt mediate growth factor-induced neuronal survival. Spinal cord sections from animals sacrificed at 8 h, 1, 2, and 7 days following the 15 min of ischemia were immunohistochemically evaluated using monoclonal antibodies for PI3-k and Akt. Following the 15 min of ischemia, the majority of the motor neurons showed selective cell death at 7 days of reperfusion. Immunoreactivity of PI3-k and Akt were induced at 8 h of reperfusion selectively in motor neuron cells. No glial cells and inter neurons were stained in the spinal cord sections. The activation of PI3-k and Akt protein at the early stage of reperfusion may be one of the factors responsible for the delay in neuronal death after spinal cord ischemia.

Objective: Glial cell line–derived neurotrophic factor (GDNF) has protective effects on various injuries involving the central and peripheral nervous systems in vitro and vivo. However, the possible protective effect of GDNF on spinal cord ischemia and the exact mechanism involved in the ameliorative effect of GDNF on ischemic spinal cord injuries are not fully understood. Therefore, we investigated the possible protective effect of the adenovirus-mediated GDNF gene delivery on transient spinal cord ischemia in rabbits. Methods: The adenoviral vector (lacZ gene as a control or GDNF gene contained) was injected directly into the lumbar spinal cord via a needle inserted into the dorsal spine 2 days before the animal was subjected to 15 minutes of spinal cord ischemia induced by infrarenal aortic occlusion. In situ terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL staining) was performed, and temporal profiles of the GDNF and caspase-3 (caspase-3 is the marker of apoptotic change) immunoreactivity were investigated. Results: In the control rabbit, the majority of motor neurons showed selective cell death at 7 days of reperfusion. Immunocytochemistry showed that in situ TUNEL staining was selectively detected at 2 days of reperfusion in motor neuron nuclei. GDNF and caspase-3 were selectively induced in the motor neuron cells at 8 hours of reperfusion. In the GDNF-treated group, a large population of motor neuron cells was still surviving at 7 days after having been subjected to 15 minutes of ischemia. Unlike the control group, the GDNF-treated group expressed GDNF persistently. Induction of TUNEL staining and immunoreactivity for caspase-3 were greatly reduced by the GDNF treatment. Conclusion: These results suggest that the reduction in motor neuron death by GDNF was greatly associated with a reduction in DNA fragmentation and apoptotic signals of the caspase-3 cascade; they further suggest a great potential for gene therapy for paraplegic patients in the future. (J Thorac Cardiovasc Surg 2000;120:1148-57)

Background and Purpose —The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. We hypothesized that spinal motor neurons might be lost by programmed cell death and investigated a possible mechanism of neuronal death by detection of double-strand breaks in genomic DNA and immunohistochemical analysis for cyclin D1 and cyclin-dependent kinases (Cdk) 4. Methods —We used a rabbit spinal cord ischemia model with a balloon catheter. Spinal cord was removed at 8 hours and 1, 2, and 7 days after 15 minutes of transient ischemia, and histological changes were studied with hematoxylin-eosin staining. In situ terminal deoxynucleotidyl transferase (TdT)–mediated dUTP-biotin nick-end labeling (TUNEL), DNA fragment with gel electrophoresis, Western blot analysis for cyclin D1 and Cdk4, and temporal profiles of cyclin D1 and Cdk4 immunoreactivity were investigated. Results —Most motor neurons were preserved until 2 days but were selectively lost at 7 days of reperfusion. Immunocytochemistry showed positive TUNEL selectively at 2 days of reperfusion in spinal motor neuron nuclei. Typical ladders of oligonucleosomal DNA fragments were detected at 2 days of reperfusion. Immunoreactivity of cyclin D1 and Cdk4 proteins was induced selectively at 8 hours in motor neuron nuclei, which eventually died. Conclusions —These results indicate that induction of cyclin D1 and Cdk4 may be implicated in programmed cell death change after transient spinal cord ischemia in rabbits.

Purpose : In an attempt to study whether ischemic spinal cord expresses a foreign gene in vivo, a replication-defective adenoviral vector containing the Escherichia coli lacZ gene was directly injected into the ischemic spinal cord of rabbits, and temporal and spatial profiles of the exogenous gene expression were compared with that of the control spinal cord. Methods : Thirty-nine Japanese domesticated white rabbits weighing 2 to 3 kg were used in this study and were divided into two subgroups, a 15-minute ischemia group and a sham control group. The adenoviral vector was directly injected into lumbar spinal cord by a needle from dorsal spine just after the infrarenal aortic occlusion in the case of ischemia. Animals were allowed to recover at ambient temperature and were killed at 1, 2, 4, and 7 days after reperfusion (n = 3 at each time point). Results : In the control rabbit, adenoviral vector was transferred into the spinal cord, and the lacZ gene was expressed at dorsal astroglia and anterior motor neurons at 1 to 7 days of reperfusion. After 15 minutes of ischemia, the lacZ gene was expressed at 2 and 4 days of reperfusion in dorsal astroglia and anterior motor neurons, which were positive for Fas antigen. Conclusion : This result suggests that it is possible to transfer and express the lacZ gene in ischemic motor neurons, which eventually show apoptotic change with induction of Fas antigen, and also suggests a great potential of gene therapy for paraplegic patients in the future. (J Vasc Surg 1999;30:542-50.)

As thrombolytic therapy for treatment of ischemic stroke was propagated, much attention has been paid to reperfusion brain injury. Oxidative stress is one of the most important factors that exacerbate tissue damage by reperfusion. Thus, we investigated the extent of oxidative damage in rat brain after transient middle cerebral artery (MCA) occlusion by immunohistochemical analysis for 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is one of the best markers of oxidative damage. Furthermore, in order to investigate its role in neuronal cell death, we performed terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) study, and compared the results with that of 8-OHdG immunohistochemistry. There was no immunoreactive 8-OHdG in sham-operated brain, but it became present in neurons of MCA territory at 3 h of reperfusion after 90-min ischemia. At 48 h after reperfusion, cerebral tissue of MCA territory was severely destroyed, and many cells in that area revealed TUNEL positivity. Some neurons in MCA territory showed mild immunoreactivity for 8-OHdG at that time, but it was strongest in neurons in the outer area of MCA territory. Those cells did not show TUNEL positivity, suggesting that 8-OHdG production is not necessarily followed by early cell death. Here, it was demonstrated that oxidative DNA damage occurs in more extended area than that where cell death is recognized. Although this damage does not cause early cell death, this might result in more prolonged cell dysfunction and eventual neuronal loss. Anti-oxidant therapy might be required for treatment of stroke in the future.

We present a case of a 79-year-old man who underwent mitral valve and aortic valve replacement. The patient's postoperative period was almost uneventful. At his cardiac preoperative examination, a malignant tumor of the urinary tract had been suspected, so computed tomography (CT) was performed after discharge, on the 48th postoperative day. The CT scan demonstrated a pseudoaneurysm of the internal mammary artery (IMA). Angiography demonstrated that it was a pseudoaneurysm of the left internal manmary artery. The lesion was embolized using coils, which successfully occluded the lesion.

The induction and distribution of 3-l-nitrotyrosine (NO2-Tyr) were examined with HPLC and immunohistochemistry in rabbit spinal cords after 15 minutes of transient ischemia until 7 days of the reperfusion. After the 15-minute ischemia, there was a significant decrease of neurologic scores in the ischemic group compared with the sham-operated control group at 7 days of reperfusion ( P = 0.0017), and the majority of motor neurons was selectively lost at 7 days of reperfusion ( P = 0.0039). NO2-Tyr was transiently induced at 8 hours of reperfusion in the ventral part of the spinal cord (0.47% ± 0.86%, NO2-Tyr/total tyrosine; P = 0.0021), but was not induced at any time point of reperfusion in the dorsal part of the spinal cord. Strong immunoreactivity for NO2-Tyr was selectively induced in large pyramidal motor neurons at 8 hours of reperfusion and was still weakly present until 7 days of reperfusion. (There may be a difference in sensitivity between the two techniques.) These results suggested that protein tyrosine nitration by nitric oxide plays a role in the selective motor neuron cell damage after transient spinal cord ischemia.

The technique of open distal anastomosis or application of aortic balloon occlusion catheter designed to occlude the descending thoracic aorta have been used in 33 and 19 patients, respectively, to control bleeding during the procedure of distal anastomosis for complete aortic arch replacement with a prosthetic graft. These two techniques allowed us a simple approach to the lesion and the avoidance of clamp injury to the fragile aortic tissue. Open distal anastomosis was applied for 91% patients of operated aortic dissection and all emergent cases, it's duration ranged from 10 to 110 minutes with an average of 58 minutes under 18.2 degrees C of lowest esophageal temperature. On the other hand, aortic occlusion balloon was inserted for mainly true aortic aneurysm patients without an emergency, and helped to maintain the perfusion pressure on a lower part of body around 50 mmHg by the 1550 ml/min in an average of perfusion flow femoral artery under 21.2 degrees C of temperature. The difference of postoperative renal and liver function evaluated by serum enzyme levels of total bilirubin, GOT, GPT, LDH, creatinine and BUN did not reach to statistical significance between the patients using open distal anastomosis and balloon occlusion, however, the incidence of postoperative complication including either renal, liver dysfunction, abdominal problem or paraplegia was significantly higher in the patient group with open distal technique. Either open distal anastomosis or aortic balloon occlusion technique would be appropriately selected according to the patient's characteristics or the condition of aortic disease to be operated.

Background and Purpose —Some neuronal subpopulations are especially vulnerable to ischemic injury. In the spinal cord, large motor neurons are vulnerable to ischemia and are selectively lost after transient ischemia. However, the mechanisms of the neuronal loss have been uncertain. We hypothesized that spinal motor neurons might be lost by apoptosis and investigated a possible mechanism of neuronal death by detection of double-strand breaks in genomic DNA and immunohistochemical analysis for caspases, ie, interleukin-1β converting enzyme (ICE), Nedd-2 , and CPP32. Methods —We used a rabbit spinal cord ischemia model created with a balloon catheter. The spinal cord was removed at 8 hours, 1, 2, or 7 days after 15 minutes of transient ischemia, and histological changes were studied with hematoxylin-eosin staining. To detect double-strand breaks in DNA, a staining with terminal deoxynucleotidyl transferase–mediated dUTP-biotin in situ nick end labeling (TUNEL) was performed. Furthermore, expression of ICE, Nedd-2 , and CPP32 was investigated by Western blotting and immunohistochemical analysis. Results —Motor neurons were selectively lost at 7 days after transient ischemia. TUNEL study demonstrated that no cells were positively labeled until 1 day after ischemia, but nuclei of some motor neurons were positively labeled at 2 days. Western blot analysis revealed no immunoreactivity for ICE and slight immunoreactivities for Nedd-2 and CPP32 in the sham-operated spinal cords. However, immunoreactivity became apparent at 8 hours after transient ischemia, decreased at 1 day, and returned to baseline level at 2 days. Immunohistochemical analysis demonstrated that motor neurons were responsible for induction of those caspases. Conclusions —Double-strand breaks in genomic DNA and induction of three caspases were demonstrated. These results indicate that motor neuron death in the spinal cord after transient ischemia is profoundly associated with activation of apoptotic processes.

Twenty-four consecutive patients underwent epidural cooling as an adjunct to elective thoracoabdominal aortic repair under moderate systemic hypothermia. One patient suffered from postoperative paraplegia (4%), and another died from subarachnoidal hemorrhage (4%). Details of the technique, the associated care, and the pitfalls will be discussed.

The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. We investigated a possible mechanism of neuronal death by immunohistochemical analysis for DJ-1, PINK1, and alpha-Synuclein. We used a 15-min rabbit spinal cord ischemia model, with use of a balloon catheter. Western blot analysis for DJ-1, PINK1, and alpha-Synuclein; temporal profiles of DJ-1, PINK1, and alpha-Synuclein immunoreactivity; and double-label fluorescence immunocytochemical studies were performed. Western blot analysis revealed scarce immunoreactivity for DJ-1, PINK1, and alpha-Synuclein in the sham-operated spinal cords. However, they became apparent at 8 h after transient ischemia, which returned to the baseline level at 1 day. Double-label fluorescence immunocytochemical study revealed that both DJ-1 and PINK1, and DJ-1 and alpha-Synuclein were positive at 8 h of reperfusion in the same motor neurons, which eventually die. The induction of DJ-1 and PINK1 proteins in the motor neurons at the early stage of reperfusion may indicate oxidative stress, and the induction of alpha-Synuclein may be implicated in the programmed cell death change after transient spinal cord ischemia.

The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. We previously reported that spinal motor neurons might be lost by programmed cell death, and investigated a possible mechanism of neuronal death by immunohistochemical analysis for Phosphorylated Bad (P-Bad) and Bad. We employed rabbit spinal cord ischemia model with an use of balloon catheter. The spinal cord was removed at 8 hours, 1, 2, or 7 days after 15 min of transient ischemia, and western blot analysis for P-Bad and Bad and double-label fluorescence immunocytochemical studies were performed. Western blot analysis revealed no immunoreactivity for P-Bad and Bad in the sham-operated spinal cords. However, they became apparent at 8 hours after transient ischemia, which returned to the baseline level at 1 day. Double-label fluorescence immunocytochemical study revealed that both P-Bad and Bad were positive at 8 hours of reperfusion in the same motor neurons which eventually die. These results suggest that transient spinal cord ischemia activates both cell death and survival pathways after ischemia. The induction of P-Bad protein at the early stage of reperfusion may be one of the factor responsible for the delay in neuronal death after spinal cord ischemia.

Noonan syndrome (NS) and cardio-facio-cutaneous (CFC) syndrome are autosomal dominant disorders characterized by heart defects, facial dysmorphism, ectodermal abnormalities, and mental retardation. There is a significant clinical overlap between NS and CFC syndrome, but ectodermal abnormalities and mental retardation are more frequent in CFC syndrome. Mutations in PTPN11 and KRAS have been identified in patients with NS and those in KRAS, BRAF and MAP2K1/2 have been identified in patients with CFC syndrome, establishing a new role of the RAS/MAPK pathway in human development. Recently, mutations in the son of sevenless gene (SOS1) have also been identified in patients with NS. To clarify the clinical spectrum of patients with SOS1 mutations, we analyzed 24 patients with NS, including 3 patients in a three-generation family, and 30 patients with CFC syndrome without PTPN11, KRAS, HRAS, BRAF, and MAP2K1/2 (MEK1/2) mutations. We identified two SOS1 mutations in four NS patients, including three patients in the above-mentioned three-generation family. In the patients with a CFC phenotype, three mutations, including a novel three amino-acid insertion, were identified in one CFC patient and two patients with both NS and CFC phenotypes. These three patients exhibited ectodermal abnormalities, such as curly hair, sparse eyebrows, and dry skin, and two of them showed mental retardation. Our results suggest that patients with SOS1 mutations range from NS to CFC syndrome.

We present a case of an 88-year-old female with a history of tuberculosis, who was transferred to our hospital due to the sudden onset of epigastralgia and back pain. A chest X-ray demonstrated a bilateral shadow of the upper lung, which suggested the history of tuberculosis. A computed tomography scan demonstrated a large amount of hematoma from the neck to mediastinum and leakage of contrast medium around the distal aortic arch. We diagnosed rupture of thoracic aortic aneurysm, and selected conservative treatment. The patient was intubated under sedation and blood pressure was controlled with vasodepressors. The patient was completely off the ventilator after 65 days of disease, and the patient was discharged after 4 months. This is the first successful case of conservative therapy for ruptured thoracic aortic aneurysm.

We report a case of transfusion-associated graft-versus-host disease in a previously healthy, 68-year-old Japanese man following an emergency surgery for an acute aortic dissection. We confirmed the chimerism of lymphocytes and the effect of drug therapy using DNA polymorphism analysis. This method is a sensitive, convenient, and rapid method that it is also useful for the evaluation of therapy. And the combination therapy with methylprednisolone, cyclosporine, and 15-deoxyspergualin may be effective in treating transfusion-associated GVHD.

Background and Purpose—Activated protein C (APC) has beneficial effects on ischemia reperfusion injury in neuron. However, the possible mechanism of such beneficial effects is not fully understood. The aim of this study was to investigate the effects and possible mechanisms of APC on ischemic spinal cord damage.Methods—After induction of spinal cord ischemia, APC (group A) or vehicle (group I) was injected intravenously. Severity of ischemic damage was analyzed by counting the number of motor neurons. To investigate the mechanisms by which APC prevents ischemic spinal cord damage, we performed immunoreactivity and Western blotting of insulin-like growth factor 1 (IGF-1), IGF-1 receptor, and phosphorylated serine-threonine kinase (p-Akt).Results—APC eased the functional deficits and increased the number of motor neurons after ischemia. Immunoreactivity of IGF-1 in group A was stronger than in group I at 8 hours after reperfusion but was at the same level at 1 day. Induction of IGF-1 receptor and the downstream factor p-Akt was stronger and more prolonged in group A.Conclusions—These results indicate that induction of IGF-1, IGF-1 receptor, and p-Akt might partially explain the neuroprotective effects of APC after transient spinal cord ischemia in rabbit.

Noonan syndrome (NS) is characterized by short stature, characteristic facial features, and heart defects. Recently, missense mutations of PTPN11, the gene encoding protein tyrosine phosphatase (PTP) SHP-2, were identified in patients with NS. Further, somatic mutations in PTPN11 were detected in childhood leukemia. Recent studies showed that the phosphatase activities of five mutations identified in NS and juvenile myelomonocytic leukemia (JMML) were increased. However, the functional properties of the other mutations remain unidentified. In this study, in order to clarify the differences between the mutations identified in NS and leukemia, we examined the phosphatase activity of 14 mutants of SHP-2. We identified nine mutations, including a novel F71I mutation, in 16 of 41 NS patients and two mutations, including a novel G503V mutation, in three of 29 patients with leukemia. Immune complex phosphatase assays of individual mutants transfected in COS7 cells showed that ten mutants identified in NS and four mutants in leukemia showed 1.4-fold to 12.7-fold increased activation compared with wild-type SHP-2. These results suggest that the pathogenesis of NS and leukemia is associated with enhanced phosphatase activity of mutant SHP-2. A comparison of the phosphatase activity in each mutant and a review of previously reported cases showed that high phosphatase activity observed in mutations at codons 61, 71, 72, and 76 was significantly associated with leukemogenesis.

A 76-year-old man underwent endovascular stent-grafting therapy for chronic aortic dissection. The preoperative multi detector row helical computed tomography (CT) revealed that Adamkiewicz's artery originated from the level of thoracic 9 intercostal artery. Intraoperative monitoring of motor evoked potentials showed no reduction of amplitude in the anterior tibialis muscle after deployment retrievable stent-graft. Postoperative CT showed that stent-graft blocked the ostium of intercostal arteries including Adamkiewicz's artery. On the other hand, the distal portion of the Adamkiewicz's artery was clearly enhanced. Our result showed that there is a collateral network supplying to Adamkiewicz's artery.

Objective: The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells to ischemia. However, the mechanisms of such vulnerability are not fully understood. We previously reported that spinal motor neurons might be lost as a result of programmed cell death and investigated a possible mechanism of neuronal death by means of immunohistochemical analysis for CPP32 (caspase3) and serine-threonine kinase (Akt). Methods: We used a rabbit spinal cord ischemia model with use of a balloon catheter. The spinal cord was removed at 8 hours or 1, 2, or 7 days after 15 minutes of transient ischemia, and histologic changes were studied with hematoxylin and eosin staining. Western blot analysis for Akt and caspase3, temporal profiles of Akt and caspase3 immunoreactivity, and double-label fluorescence immunocytochemical studies were performed. Results: The majority of motor neurons were preserved until 2 days but were selectively lost at 7 days of reperfusion. Western blot analysis revealed no immunoreactivity for Akt and caspase3 in the sham-operated spinal cords. However, such immunoreactivity became apparent at 8 hours after transient ischemia, decreased at 1 day, and returned to the baseline level at 2 days. A double-label fluorescence immunocytochemical study revealed that both Akt and caspase3 were positive at 8 hours of reperfusion in the same motor neurons, which eventually die. Conclusion: These results suggests that transient spinal cord ischemia activates both cell death and survival pathways after ischemia. The activation of Akt protein at the early stage of reperfusion might be one of the factors responsible for the delay in neuronal death after spinal cord ischemia. J Thorac Cardiovasc Surg 2003;125:370-7

Objectives: Paraplegia is one of the serious complications of thoracoabdominal aortic operations. Regional hypothermia protects against spinal cord ischemia although the protective mechanism remains unknown. We attempted to create a simple model of local cooling under transient spinal cord ischemia and evaluated the effect using functional and histologic findings. Methods: Male domesticated rabbits were divided into 3 groups: control, normothermic group (group N), and local hypothermic group (group H). A balloon catheter was used for spinal cord ischemia by abdominal aortic clamping. A cold pack attached to the lumbar region could lower the regional cord temperature initially. Neurologic function was evaluated by the Johnson score. Cell damage was analyzed by observing motor neurons with the use of hematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated deoxy-uracil triphosphate biotin in situ nick end labeling (TUNEL), and immunoreactivity of heat shock protein. Results: Physiologic estimation showed that local hypothermia improved the functional deficits (group N, 1.3 ± 0.9; group H, 4.9 ± 0.3; P =.0020). Seven days after reperfusion, there was a significant difference in the motor neuron numbers between groups N and H (group N, 7.2 ± 1.9; group H, 20.4 ± 3.2; P =.0090). The number of TUNEL-positive motor neurons was reduced significantly (group N, 7.2 ± 2.4; group H, 1.0 ± 0.7; P =.0082). Heat shock protein immunoreactivity was prolonged up to 2 days after reperfusion in the hypothermic group. Conclusions: These results suggest that local hypothermia extended the production of heat shock protein in spinal cord motor neurons after reperfusion and inhibited their apoptotic change. J Thorac Cardiovasc Surg 2001;122:351-7

Objective Spinal cord ischemia sometimes causes paraplegia because the spinal motor neuron cells are vulnerable to ischemia. Although various protective remedies for spinal cord injury have been reported, there have been few established clinical methods. Although hyperbaric oxygen (HBO) has been used clinically as a treatment for ischemia, the reason for its effectiveness is still uncertain because sufficient experimental data are lacking. Design Prospective, randomized, controlled study. Setting Experimental animal research laboratory in a university research center. Subjects Twenty-three Japanese white rabbits, weighing 2–3 kg. Interventions A modified rabbit spinal cord ischemia model of infrarenal aortic occlusion for 15 mins was employed. Rabbits were randomly assigned to four groups; the rabbits in group A did not undergo ischemic insults (n = 5). The rabbits in groups B and C underwent ischemic insult for 15 mins, followed by 1 hr of HBO treatment at 3 atm absolute with 100% oxygen at 30 mins (n = 6) or 6 hrs (n = 7) after reperfusion, respectively. The rabbits in group D underwent ischemic insult for 15 mins without HBO treatment (n = 5). Measurements and Main Results We observed neurologic functions for 14 days. The sections of the spinal cords were stained with hematoxylin and eosin, and the number of spinal motor neurons in ventral region was counted by light microscopy. All rabbits in groups A and B could stand, whereas all rabbits in groups C and D showed irreversible paraplegia on days 2 and 14 after reperfusion. Spinal motor neurons in ventral gray matter in groups C and D decreased significantly compared with those in groups A and B. Conclusions HBO therapy shortly after ischemic insult had protective effects against ischemic spinal cord damage. However, delayed treatment with HBO did not change the prognosis.

The mechanism of spinal cord injury has been thought to be related with tissue ischemia, and spinal motor neuron cells are suggested to be vulnerable to ischemia. To evaluate the mechanism of such vulnerability of motor neurons, we attempted to make a reproducible model of spinal cord ischemia. Using this model, the inductions of glial cell line-derived neurotrophic factor (GDNF) and the c-ret porto-oncogene (RET) receptor tyrosine kinase were investigated with immunohistochemical analyses for up to 7 days of the reperfusion following 15 min of ischemia in rabbit spinal cord. Spinal cord sections from animals sacrificed at 8 h, 1, 2, and 7 days following the 15 min of ischemia were immunohistochemically evaluated using monoclonal antibodies for GDNF and RET. Following the 15 min of ischemia, the majority of the motor neurons showed selective cell death at 7 days of reperfusion. Immunoreactivity of GDNF and RET were induced at 8 h of reperfusion selectively in motor neuron cells. No glial cells were stained in the spinal cord sections. The induction of GDNF and RET proteins at the early stage of reperfusion may be related to the transient functional recovery of neurons after ischemia.

Hepatocyte growth factor (HGF) is a potent pleiotrophic peptide which has a trophic role for neuronal cells. As it exerts its effect only after a conversion to its heterodimeric active form, the activation step, which is catalyzed by an enzyme serine protease named HGF activator (HGFA), is of great importance. HGF activated by HGFA may act as a protecting agent in injured brain. In the present study, we investigated expression of immunoreactive HGF and HGFA in rat brain after permanent middle cerebral artery (MCA) occlusion. By immunohistochemical analysis, HGF and HGFA were normally expressed only in ependymal cells and choroid plexus. At 1 h after MCA occlusion, neurons in the ischemic penumbra region of the cerebral cortex slightly expressed immunoreactive HGFA. HGF was not induced at that time. At 3 h of ischemia, however, immunoreactive HGF as well as HGFA became detectable in neurons of the ischemic cerebral cortex and caudate. Immunoreactivity for HGF continued to increase until 24 h, while that for HGFA remained almost constant from 3 to 24 h. No glial or vascular endothelial cells expressed HGF nor HGFA. By Western blot analysis for HGF, a single band of molecular weight (MW) 34 kDa became apparent at 24 h, corresponding to the light chain of the active form HGF. The present study suggests that HGF and HGFA were induced in neurons under permanent ischemia with slightly different temporal profiles. Through activation by HGFA, the active form of HGF could serve as a neurotrophic factor in ischemic brain.

The mechanism of spinal cord injury has been thought to be related with tissue ischemia, and spinal motor neuron cells are suggested to be vulnerable to ischemia. To evaluate the mechanism of such vulnerability of motor neurons, we attempted to make a reproducible model for spinal cord ischemia. Using this model, cell damage was histologically analyzed. Detection of ladders of oligonucleosomal DNA fragment was investigated with gel electrophoresis up to 7 days of the reperfusion. Time course expression of Fas antigen, identified as a apoptosis-regulating molecules, was also assessed in rabbit spinal cord following transient ischemia. Spinal cord sections from animals sacrificed at 8 h, 1 day, 2 days, and 7 days following 15-min ischemia were immunohistochemically evaluated using monoclonal antibodies for Fas antigen. Following 15-min ischemia, the majority of motor neuron showed selective cell death at 7 days of reperfusion. Typical ladders of oligonucleosomal DNA fragments were detected at 2 days of reperfusion. Immunoreactivity of Fas antigen were induced at 8 h to 1 day of reperfusion selectively in motor neuron cells. The expression of Fas antigen may be related to the activation of apoptosis signal in motor neuron cells after spinal cord ischemia in rabbits.

Objective: The mechanism of spinal cord injury has been thought to be related to tissue ischemia, and spinal motor neuron cells are suggested to be vulnerable to ischemia. We hypothesized that delayed and selective motor neuron death is apoptosis. Methods: Thirty-seven Japanese domesticated white rabbits weighing 2 to 3 kg were used in this study and were divided into two subgroups: a 15-minute ischemia group and a sham control group. Animals were allowed to recover at ambient temperature and were killed at 8 hours, and 1, 2, 4, and 7 days after reperfusion ( n = 3 at each time point). By means of this model, cell damage was histologically analyzed. Detection of ladders of oligonucleosomal DNA fragment was investigated with gel electrophoresis up to 7 days of the reperfusion. Immunocytochemistry, in situ terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate–biotin nick-end labeling staining was also performed. Results: After 15 minutes of ischemia, most of the motor neurons showed selective cell death at 7 days of reperfusion. Typical ladders of oligonucleosomal DNA fragments were detected at 2 days of reperfusion. Immunocytochemistry showed in situ terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate–biotin nick-end staining was detected at 2 days of reperfusion selectively in the nuclei of motor neurons. Conclusion: These results suggest that delayed and selective death of the motor neuron cells after transient ischemia may not be necrotic but rather predominantly apoptotic. (J Thorac Cardiovasc Surg 1998;115:1310-5)

Purpose: This investigation was designed to evaluate the mechanism used to acquire a tolerance to spinal ischemia. We investigated inductions of the heat shock protein (HSP) 70 gene and protein in rabbit spinal cord with or without preconditioning. Methods: Neurologic function, morphologic changes, and inductions of HSP70 messenger RNA (mRNA) and protein were compared in the cases of a 15-minute ischemia 2 days after sham treatment and a 15-minute ischemia 2 days after 10-minute preconditioning. Result: HSP70 mRNA was induced at 8 hours of reperfusion after a 15-minute ischemia 2 days after sham treatment. HSP70 protein was induced slightly in selective motor neuron cells at 8 hours of reperfusion, and about 70% of motor neuron cells showed selective cell death after 7 days of reperfusion (p < 0.01). On the other hand, large populations of the motor neuron cells survived at 7 days after the 15-minute ischemia that was applied at 2 days after preconditioning (p < 0.01). HSP70 mRNA was induced persistently as compared with the case of a 15-minute ischemia 2 days after sham treatment. The motor neuron cells strongly produced immunoreactive HSP70 from 8 hours to 2 days. Conclusion: Preconditioning with 10-minute ischemia enhanced and prolonged the HSP70 gene expression at both mRNA and protein levels and saved the motor neuron cells from subsequent lethal ischemia. These changes of HSP70 gene expression may play an important role in the acquisition of ischemic tolerance of motor neuron cells in rabbit spinal cord. (J Vasc Surg 1998;27:720-5.)

Paraplegia is a serious complication that sometimes results from operation on the thoracic aorta. The mechanism of spinal cord injury has been thought to involve tissue ischemia, and spinal motor neurons are suggested to be vulnerable to ischemia. The exact mechanism, however, is not fully understood. To evaluate the mechanism of such vulnerability of motor neurons, we attempted to make a reproducible model for spinal cord ischemia and statistically analyzed cell damage. With this model, induction of heat shock protein 70 (HSP70) and heat shock cognate protein (HSC70) messenger ribonucleic acid molecules were investigated with Northern blot analysis for up to 7 days of reperfusion after 5 or 15 minutes of ischemia. Immunohistochemical studies of their proteins were also done. (heat shock proteins are a set of markers of neuronal injury after ischemia.) After 5 minutes of ischemia, there was no induction of HSP70 and HSC70 messenger ribonucleic acid molecules or their proteins, and all cells remained intact. In contrast, after 15 minutes of ischemia, HSP70 messenger ribonucleic acid was induced at 8 hours of reperfusion, and HSC70 messenger ribonucleic acid was expressed continuously at the control level. Immunoreactivity of HSP70 protein was slightly induced at 8 hours of reperfusion selectively in motor neurons, and about 70% of motor neuron cells showed selective cell death after 7 days of reperfusion. This study demonstrated induction of HSP70 messenger ribonucleic acid and its protein in motor neuron cells after transient ischemia in the spinal cord. This phenomenon was not accompanied by HSC70 induction. (J Thorac Cardiovasc Surg 1997;113:159-64)

The inductions of HSP72 and HSC73 mRNAs were investigated with Northern blot and immunohistochemical analyses for up to 7 days of the reperfusion after 5 or 15 min ischemia in rabbit spinal cord. Following 15 min ischemia, HSP72 mRNA was induced at 8 h of reperfusion, while HSC73 mRNA continuously remained at the control level. Immunoreactivity of HSP72 protein was slightly induced at 8 h of reperfusion selectively in motor neurons, and the majority of motor neuron showed selective cell death at 7 days of reperfusion. This study demonstrated selective induction of HSP72 mRNA and the protein in motor neuron cells that eventually showed selective delayed neuronal death after transient ischemia in the spinal cord. This phenomenon was not accompanied by HSC73 induction.

The distributions and inductions of Cu/Zn superoxide dismutase (SOD), neuronal and endothelial nitric oxide (NO) synthase (nNOS and eNOS), and nitrotyrosine (NT) were immunohistochemically examined in rabbit spinal cords after 5 and 15 min of transient ischemia. The neurons in the anterior horns (AH) were selectively lost 7 days after 15-min ischemia as compared with those of sham-operated controls. In the normal spinal cords, a number of neurons in the AHs were positive for the nNOS, and only slightly positive for the Cu/Zn SOD and the eNOS. Immunoreactivities for the proteins were induced at 8-24 h both after 5- and 15-min ischemia. In contrast, NT-like immunoreactivity was negative both in the normal and postischemic spinal cords. These results suggest that Cu/Zn SOD- and nNOS-, and eNOS-like immunoreactivities are induced, but that, even though an interaction of Cu/Zn SOD with NO could be present, NT was not detected in the motor neurons in the rabbit spinal cords after transient ischemia. Other factors could be required for NT formation found in degenerative motor neuron death in humans.

We report a case of isolated congenital tricuspid regurgitation caused by a cleft in the anterior tricuspid leaflet associated with a patent foramen ovale. Preoperative echocardiography revealed severe tricuspid regurgitation resulting from anterior tricuspid leaflet prolapse. The patient underwent successful tricuspid valve repair with simple cleft suture and annuloplasty and direct closure of the patent foramen ovale.

ObjectiveSpinal cord injury is considered to be related to a vulnerability of spinal motor neurons to ischemia. However, the mechanisms underlying this vulnerability are not fully understood. We investigated the role of autophagy, which is an intracellular bulk degradation process, at motor neuron as a potential mechanism of neuronal death by immunohistochemical analysis for microtubule-associated protein light chain3 (LC3) and γ-aminobutyric-acid type-A-receptor-associated protein (GABARAP) which are considered as markers of autophagy.MethodsWe used a rabbit spinal cord ischemia model with the use of a balloon catheter. The spinal cord was removed at 8 hours, 1, 2, or 7 days after 15 minutes of transient ischemia, and histologic changes were examined with hematoxylin-eosin staining. Western blot analysis for LC3 and GABARAP, temporal profiles of LC3 and GABARAP immunoreactivity, and double-label fluorescence immunocytochemical studies were performed.ResultsIn the ischemia group, about 85% of motor neurons were preserved until 2 days after reperfusion, but were selectively lost at 7 days (P < .001 compared with sham group). Western blot analysis demonstrated slight immunoreactivity for LC3 and GABARAP in the sham-operated spinal cords. In contrast, the ischemia group LC3 and GABARAP immunoreactivity became apparent at 8 hours after reperfusion. With quantitative analysis we found that ischemia affected expression profiles of LC3-II and GABARAP. At 8 hours after reperfusion, co-labeling of LC3 and GABARAP were observed in the same motor neurons that eventually died.ConclusionThese data suggest that autophagy was induced in motor neurons by transient spinal cord ischemia in rabbits.Clinical RelevancePatients undergoing thoracic aneurysm repair who awake with no neurologic deficit immediately after operation can sometimes eventually develop paraplegia. However, the exact mechanism of this delayed vulnerability is not fully understood. In the present study, we demonstrated that following spinal cord ischemia in rabbits, expression of both LC3 and GABARAP were increased in the same motor neurons which eventually died, suggesting strong induction of autophagy in those cells. Thus, the results of the present study indicate that autophagy may be a potential mechanism of neuronal cell death in this model.

Objective: The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. We previously reported that spinal motor neurons may be lost by programmed cell death and thus now investigate a possible mechanism of neuronal death with immunohistochemical analysis for 8-hydroxy-2′-deoxyguanosine (8-OHdG) and redox factor-1 (Ref-1). Methods: We used a rabbit spinal cord ischemia model with a balloon catheter. The spinal cord was removed at 8 hours, 1, 2, or 7 days after 15 minutes of transient ischemia, and histologic changes were studied with hematoxylin-eosin staining. Western blot analysis for Ref-1, temporal profiles of 8-OHdG and Ref-1 immunoreactivity, and double-label fluorescence immunocytochemical studies were performed. Results: Most motor neurons were preserved until 2 days but were selectively lost at 7 days of reperfusion. Western blot analysis of a sample from sham control spinal cord showed a characteristic 37-kDa band that was reduced after ischemia. Immunohistochemistry showed the nuclear expression of Ref-1 in motor neurons of control spinal cords, and immunoreactivity was decreased 1 day after ischemia. On the other hand, no nuclear expression was seen of 8-OHdG in motor neurons of control spinal cords, and immunoreactivity was increased 1 day after ischemia. Double-label fluorescence immunocytochemical study revealed that both 8-OHdG and Ref-1 were positive at 8 hours of reperfusion in the same motor neurons, which eventually die. Conclusion: These results suggest that Ref-1 decreased in motor neurons after transient spinal cord ischemia and that this reduction preceded oxidative DNA damage. The reduction of Ref-1 protein at the moderately late stage of reperfusion may be one of the factors responsible for the delay in neuronal death after spinal cord ischemia. (J Vasc Surg 2003;37:446-52.)