Simultaneous blockade of co-stimulatory signals, CD28 and ICOS, induced a stable tolerance in rat heart transplantation

An inducible co-stimulator (ICOS), a recently identified co-stimulatory receptor with a close structural homology of CD28 and CTLA4, is expressed on activated T cells. Anti-ICOS antibody was demonstrated to be effective on prolongation of graft survival after liver transplantation in rats. In this study, we investigated the potency of tolerance induction using the antibody combined with a recombinant adenovirus vector containing CTLA-4Ig cDNA (AdCTLA-4Ig) in rat heart transplantation model. Using a DA-to-Lewis rat heart transplantation model, an anti-rat ICOS antibody and AdCTLA-4Ig were simultaneously administered i.v. into recipients. The tissue specimens from the grafts were removed on various days after transplantation for histological evaluation. Donor-strain skin and heart grafts, and third-party heart allografts were challenged in the recipients with a long-term surviving graft. Splenocytes from the tolerance-induced recipients were used for adoptive transfer study. Anti-ICOS antibody alone did not prolong the survival of heart allograft. AdCTLA-4Ig monotherapy significantly prolonged the survival of heart allograft (Group 4). With a combination of Anti-ICOS antibody and AdCTLA-4Ig, all recipients were resulted in a long-term allograft acceptance for more than 200 days (Group 8). When challenged donor-strain skin grafts in the tolerant rats of Group 4, the skin was rejected, which also lead to a rejection of primary heart allografts. The recipients in Group 8 also rejected donor-strain skin grafts with no rejection of the primary heart grafts. These recipients accepted secondary heart grafts from donor-strain but not third-party. In Group 8 long-term survival recipients showed a high population of CD4+CD25+ regulatory T cell in peripheral blood, and in adoptive transfer study subtraction of these CD4+CD25+ T cells accelerate the rejection of heart graft in secondary irradiated recipients. The present results demonstrated that anti-ICOS antibody combined with AdCTLA-4Ig potently induces a stable immune tolerance after heart allografting in rat, which is mediated by the induction of CD4+CD25+ regulatory T cells. This strategy may be attractive for clinical employment to induce transplantation tolerance.     

Bilateral anomalous posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomotic arteries associated with a ruptured cerebral aneurysm--case report

A 50-year-old man presented with subarachnoid hemorrhage from a ruptured cerebral aneurysm arising from a left posterior inferior cerebellar artery (PICA)-anterior inferior cerebellar artery anastomotic artery manifesting as severe headache, obtundation, and quadriplegia. Conventional and three-dimensional digital subtraction angiography showed that the anastomotic complex was present bilaterally and both vertebral arteries terminated at the origin of the PICA. The identification of this anomalous vascular network allowed coil embolization of the broad-based aneurysm with occlusion of the parent artery. The patient had residual moderate disturbance of consciousness and quadriplegia before transfer for rehabilitation.     

Long-term assessment of hind limb motor function and neuronal injury following spinal cord ischemia in rats

Recent evidence suggests that brain injury caused by ischemia is a dynamic process characterized by ongoing neuronal loss for at least 14 days after ischemia. However, long-term outcome following spinal cord ischemia has not been extensively examined. Therefore, we investigated the changes of hind limb motor function and neuronal injury during a 14-day recovery period after spinal cord ischemia. Male Sprague-Dawley rats received spinal cord ischemia (n = 64) or sham operation (n = 21). Spinal cord ischemia was induced by inflation of a 2F Fogarty catheter placed into the thoracic aorta for 6, 8, or 10 minutes. The rats were killed 2, 7, or 14 days after reperfusion. Hind limb motor function was assessed with the 21-point Basso, Beattie, and Bresnahan (BBB) scale during the recovery period. The number of normal and necrotic neurons was counted in spinal cord sections stained with hematoxylin/eosin. Longer duration of spinal cord ischemia produced severer hind limb motor dysfunction at each time point. However, BBB scores gradually improved during the 14-day recovery period. Neurologic deterioration was not observed between 7 and 14 days after reperfusion. The number of necrotic neurons peaked 2 days after reperfusion and then decreased. A small number of necrotic neurons were still observed 7 and 14 days after reperfusion in some of the animals. These results indicate that, although hind limb motor function may gradually recover, neuronal loss can be ongoing for 14 days after spinal cord ischemia.     

Anesthetic management of four cases of craniotomy with alternate monitoring of motor and somatosensory evoked potentials

We experienced four cases of craniotomy in which motor evoked potential (MEP) and somatosensory evoked potential (SEP) were monitored alternately. Anesthesia was induced with propofol and fentanyl, and it was maintained with continuous infusion of propofol. Intermittently, propofol and fentanyl were administered as needed. Inhalation of 66% nitrous oxide did not prolong latency, but significantly reduced the amplitude of MEP. We could obtain the largest amplitude of MEP using five consecutive stimuli of which duration and frequency were 0.5 milliseconds and 500 Hz, respectively. Anesthetic management using propofol and fentanyl is useful for craniotomy with monitoring of MEP and SEP.     

The analysis of mitral annular disjunction detected by echocardiography and comparison with previously reported pathological data

Background

Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus and is pathologically defined by a separation between the atrial wall–mitral valve junction and the left ventricular attachment. Mitral annular disjunction can cause hypermobility of the mitral valve apparatus and is often associated with mitral valve prolapse (MVP). The aim of this study was to investigate the frequency and characteristics of mitral annular disjunction in the patients referred to an echocardiography laboratory and to compare these with previously reported pathological data.

Methods and results

We retrospectively studied 1439 patients (mean age 65 ± 17 years, 58% male) referred to our echocardiography laboratory from 6 January 2014 to 31 March 2014. The echocardiographic parameters were compared between the patients with and without mitral annular disjunction. There were 125 cases (8.7%) with mitral annular disjunction, of which 15 (12%) also had MVP. The number of MVP patients in the group with mitral annular disjunction was significantly larger than in the group without mitral annular disjunction (p < 0.0001). The grade of mitral regurgitation was not significantly different between the two groups.

Conclusions

Mitral annular disjunction was detected not only in patients with a myxomatous mitral valve but also in normal cases. The number of MVPs was significantly larger in patients with mitral annular disjunction than patients without mitral annular disjunction. Further investigation is needed to clarify the clinical significance of the mitral annular disjunction detected by routine echocardiography.

     

Phenotype-specific cells with proliferative potential are produced by polyethylene glycol-induced fusion of mouse embryonic stem cells with fetal cardiomyocytes

Because cardiomyocytes lose the ability to divide upon differentiation, myocardial failure is assumed to be generally irreversible. For terminal cardiac insufficiency, the potential for regenerative treatment by stem cells, especially embryonic stem (ES) cells, offers hope for the future. Recent studies showed that stem cells fuse spontaneously with cells remaining in damaged tissues, and restore tissue function. To imitate spontaneous fusion in vivo, we used polyethylene glycol (PEG) in vitro to fuse mouse ES cells and fetal cardiomyocytes and analyzed the cytochemical properties of the fused cells. Confocal laser scanning microscopy coupled with lipophilic dye labeling of the living cell membranes showed that there were fused cells of ES cells and cardiomyocytes after PEG treatment. By flow cytometry, the fusion efficiency between ES cells and cardiomyocytes was estimated to be about 45% of the total resulting cells. When green fluorescent protein (GFP)-expressing ES cells were fused with cardiomyocytes, the fused cells had immunoreactivity for GFP in their cytoplasm and cardiac troponin I in their myofibrils. Some of these cells also expressed proliferating cell nuclear antigen up to 11 days after fusion, the last time point examined. This study shows that PEG-induced fusions of mouse ES cells and cardiomyocytes have the cardiomyocyte phenotype and proliferation potential.     

Slit diaphragm dysfunction in proteinuric states: identification of novel therapeutic targets for nephrotic syndrome

Several recent studies have demonstrated that the slit diaphragm of the glomerular epithelial cell (podocyte) is the structure likely to be the principal barrier in the glomerular capillary wall. Nephrin identified as a gene product mutated in congenital nephrotic syndrome located at the outer leaflet of plasma membranes of the slit diaphragm. The anti-nephrin antibody is capable of inducing massive proteinuria, which indicates that nephrin is a key functional molecule in the slit diaphragm. Expression of nephrin was reduced in glomeruli of minimal change nephrotic syndrome. Some recent studies demonstrated that podocin, CD2-associated protein and NEPH1 are also functional molecules in the slit diaphragm, and their expressions are altered in membranous nephropathy and also in focal glomerulosclerosis. These observations suggested that the alteration of the molecular arrangement in the slit diaphragm is involved in the development of proteinuria in several kinds of glomerular diseases. Recent studies of our group have demonstrated that type 1 receptor-mediated angiotensin II action reduced the expression of the slit diaphragm-associated molecules and that type 1 receptor blockade ameliorated proteinuria by preventing the function of angiotensin II on the slit diaphragm. By the subtraction hybridization techniques using glomerular cDNA of normal and proteinuric rats, we detected that synaptic vesicle protein 2B and ephrin B1 are involved in the maintenance of the barrier function of the slit diaphragm. Presented at the 36th Eastern Regional Meeting of the Japanese Society of Nephrology.     

Impaired cutaneous wound healing in mice lacking tetranectin

Tetranectin was originally purified from human serum on the basis of plasminogen kringle 4-binding properties. Tetranectin enhances plasminogen activation by a tissue-type plasminogen activator so that it has been suggested to play a role in tissue remodeling. We have generated mice with a targeted disruption of the tetranectin gene to elucidate the biological function of tetranectin. In this study, we showed that wound healing was markedly delayed in tetranectin-null mice compared with wild-type mice. A single full-thickness incision was made in the dorsal skin. By 14 days after the incision, the wounds fully healed in all wild-type mice based on the macroscopic closure; in contrast, the progress of wound healing in the tetranectin null mice appeared to be impaired. In histological analysis, wounds of wild-type mice showed complete reepithelialization and healed by 14 days after the incision. However, those of tetranectin-null mice never showed complete reepithelialization at 14 days. At 21 days after the injury, the wound healed and was covered with an epidermis. These results supported the fact that tetranectin may play a role in the wound healing process.     

Clinical efficacy of naftopidil on lower urinary tract symptoms after radical prostatectomy

Objective:   The management of lower urinary tract symptoms that persist after radical prostatectomy remains to be established. We investigated whether an α1-blocker, naftopidil, improves LUTS in patients ≥1 year after radical prostatectomy.
Methods:   A total of 29 male patients received 25 mg/day of naftopidil for the first week, then 75 mg/day for 4 weeks. The frequency-volume chart, international prostate symptom score and quality of life index (QOL) were examined before and at the end of the 5-week administration in all subjects.
Results:   Total international prostate symptom score (I-PSS) and I-PSS subtotals associated with voiding symptoms and storage symptoms were significantly decreased at 5 weeks compared with baseline ( P  < 0.001 each). QOL index was significantly improved with naftopidil for 5 weeks ( P  < 0.001). From analyses of the frequency-volume chart, mean and maximum volume/void were significantly increased ( P  < 0.05 each).
Conclusion:   Lower urinary tract symptoms detected in patients ≥1 year after radical prostatectomy were markedly improved with administration of naftopidil at 75 mg/day. These symptoms could represent a novel target for medical treatment by improved understanding of the symptom pathology in the near future.     

The dynamics and clinical significance of alpha 2 plasmin inhibitor-plasmin complex and thrombin-antithrombin complex in postoperative pleural effusion following a pulmonary lobectomy

Purpose  The overall incidence of postoperative alveolar air leakage (AAL) remains high; however, the mechanism regarding how to adequately heal such postoperative AAL remains to be elucidated. The aim of this study was to determine any correlations between the activity of the fibrinolytic and coagulation system in the postoperative pleural effusion and appearance or disappearance of postoperative AAL. Methods  This study prospectively investigated 25 patients who underwent a pulmonary lobectomy from July 2005 to March 2006. Pleural effusion was collected through the chest tube. Alpha 2 plasmin inhibitor-plasmin complex (PIC), as a fibrinolytic marker, and thrombin-antithrombin complex (TAT), as a coagulation marker, were measured. Results  The activity of the coagulation system was higher than that of the fibrinolytic system. The concentration of TAT tended to increase (3rd vs 4th postoperative day [POD], P = 0.0907). The mean time of appearance and disappearance of postoperative AAL was 1.4 days and 3.2 days, respectively. The patients with postoperative AAL had a TAT level significantly below the average on the 3rd POD in comparison to the patients without postoperative AAL (P = 0.0163). Moreover, the concentration of TAT in patients with postoperative AAL was significantly lower than that in patients without postoperative AAL (1824.0 ± 137.3 ng/ml vs 3444.0 ± 287.6 ng/ml, P = 0.0113) on the 3rd POD. On the 4th POD, the concentration of TAT was almost same and there was no significance (P = 0.6759). Conclusions  This study demonstrated for the first time the course of the fibrinolytic and coagulation activity in the pleural effusion after a pulmonary lobectomy, and showed that the delayed activity of the coagulation system is associated with the appearance of the postoperative AAL.