Concomitant mitral valve repair and left ventricular reconstruction in a patient with chronic ischemic mitral regurgitation and inferior left ventricular aneurysm

The surgical approach to ischemic mitral regurgitation with concomitant inferior left ventricular aneurysm remains uncertain in terms of the indication for operation and the short-and long-term outcomes. We performed concomitant mitral valve repair, left ventricular reconstruction, and aortic valve replacement on a 71-year-old male with severe ischemic mitral regurgitation, inferior left ventricular aneurysm, and degenerative aortic regurgitation. Postoperative status was in New York Heart Association functional class I without mitral regurgitation 8 months after operation. We discuss, and review the procedures reported in the literature.     

Prediction of morbidity after lung resection with risk factors using treadmill exercise test.

OBJECTIVE: To predict accurate morbidity after lung resection using treadmill exercise test. METHODS: A total of 130 patients (108 men and 22 women, with mean age 67.1+/-11.4 years (range, 34-78 years)) of 1129 patients underwent standard lobectomy were performed both treadmill exercise test and spirometry preoperatively. We measured maximum oxygen uptake/body weight (VO2max/BW) and change in arterial blood oxygen pressure from rest to symptom-limited maximum loading (delta aPaO2) and calculated exercise-induced hypoxemia (delta PaO2/delta VO2/BW), and retrospectively compared these parameters for patients with and without complications. RESULTS: There were five patients with severe postoperative complications, including three requiring use of a respirator, two with home oxygen therapy. %Vital capacity, VC (%, 80.2+/-13.2 vs. 92.5+/-20.9, P=0.026), delta PaO2 (Torr, -29.3+/-4.3 vs. -13.2+/-10.8, P=0.0004), VO2max/BW (ml/min/kg, 16.5+/-2.9 vs. 20.6+/-5.1, P=0.018) and delta PaO2/delta VO2/BW (Torr/ml/min/kg, -1.98+/-0.26 vs. -0.57+/-0.47) were significantly associated with worse outcome. All the five patients with complications had delta PaO2/delta VO2/BW<-1.7. CONCLUSIONS: Treadmill exercise testing is a good method for assessment of cardiopulmonary reserve. Limited resection must be performed if delta PaO2/delta VO2/BW is under -1.7.     

Immunologic immaturity, but high IL-4 productivity, of murine neonatal thymic CD4 single-positive T cells in the last stage of maturation

To determine the levels of maturation and differentiation ofmurine CD4 single-positive (SP) T cells, we compared the secondaryresponses of staphylococcal enterotoxin A (SEA)-induced neonatalthymic, adult thymic and adult splenic CD4 SP T cell blastsprepared from whole or heat-stable antigen^low CD4 SP T cells.Proliferative responses upon re-stimulation with SEA were strongin adult splenic CD4 SP T cell blasts, but quite weak in neonatalthymic and adult thymic CD4 SP T cell blasts. SEA-induced IL-2production was weaker in neonatal thymic blasts than in theadult splenic CD4 SP T cell blasts. In contrast, SEA-inducedIL-4 production was high in neonatal thymic CD4 SP T cell blasts,and low in adult splenic and thymic CD4 SP T cell blasts. Expressionof GATA-3, that directs production of IL-4 in T cells, examinedat protein and mRNA levels, was higher in neonatal thymic cellsthan in adult thymic and splenic cells. These results suggestthat neonatal and adult thymic CD4 SP T cells in the final stageof maturation are relatively immature compared with adult splenicCD4 SP T cells. The cytokine production profile of neonatalthymic CD4 SP T cells suggests that they are inclined towardsa T_h2 response.     

Structural basis for distinct roles of Lys63- and Lys48-linked polyubiquitin chains

Ubiquitination, a modification in which single or multiple ubiquitin molecules are attached to a protein, serves as a signalling function that controls a wide variety of cellular processes. To date, two major forms of polyubiquitin chain have been functionally characterized, in which the isopeptide bond linkages involve Lys48 or Lys63. Lys48-linked polyubiquitin tagging is mostly used to target proteins for degradation by the proteasome, whereas Lys63-linked polyubiquitination has been linked to numerous cellular events that do not rely on degradative signalling via the proteasome. Apparently linkage-specific conformations of polyubiquitin chains are important for these cellular functions, but the structural bases distinguishing Lys48- and Lys63-linked chains remain elusive. Here, we report NMR and small-angle X-ray scattering (SAXS) studies on the intersubunit interfaces and conformations of Lys63- and Lys48-linked di- and tetraubiquitin chains. Our results indicate that, in marked contrast to Lys48-linked chains, Lys63-linked chains are elongated molecules with no stable non-covalent intersubunit interfaces and thus adopt a radically different conformation from that of Lys48-linked chains.     

In vivo study of the effects of cryopreservation on heart valve xenotransplantation.

BACKGROUND: Recent reports have suggested that cryopreservation reduces the immunogenicity of donor tissue. The immunomodulation by cryopreservation might influence on the tissue durability after xenotransplantation. We investigated the in vivo morphologic changes in cryopreserved xenograft (CXG) heart valves. MATERIAL AND METHOD: We transplanted a fresh (fresh xenograft; FXG) and a cryopreserved (CXG) porcine aortic root and a cryopreserved canine (cryopreserved allograft; CAG) aortic root into the abdominal aorta of a dog without any immunosuppressive agents. Explanted grafts on the 21st to 49th days after implantation were analyzed morphologically with light microscopy using some special stains, immunohistochemical analysis, and scanning electron microscopy (SEM). RESULT: Light microscopy showed the absence of smooth muscle cells in the media of the aorta in any group after transplantation. FXG valves did not maintain any cellularity after transplantation. CXG valves contained cellular infiltration in themselves. CAG valves contained numerous fibroblasts, which showed the maintenance of tissue integrity without allowing cellular infiltration. The structure of elastic fibers was well maintained, even in the part of CXG valve with cellular infiltration. Immunohistochemical studies documented the infiltration of T lymphocytes in CXG valves that were labeled by anti-CD3 antibodies. SEM demonstrated that no endothelia were seen on the surface of the valves in any group after transplantation. CONCLUSION: We concluded that the cryopreservation method might provide an immunomodulation of xenogeneic heart valves for transplantation.     

Lethal persistent pulmonary hypertension of the newborn in Bohring–Opitz syndrome

Bohring–Opitz syndrome (BOS) is a rare disease with a number of characteristic features, including hypertelorism, prominent metopic suture, exophthalmos, cleft palate, abnormal posture, and developmental retardation. Here, we report a BOS patient presenting with lethal persistent pulmonary hypertension of the newborn (PPHN) and inspiratory respiratory failure. The female infant was treated with nitric oxide and vasodilator, which did not improve her condition. The inspiratory respiratory failure required management with deep sedation. She died on postnatal day 60 due to progressed heart failure. Whole exome sequencing revealed de novo mutation in the ASXL1 gene, c.1934dupG, p.Gly646TrpfsTer12.     

Thoracoscopic esophagectomy in the prone position

Thoracoscopic esophagectomy performed with the patient in the left lateral position has been occasionally reported since the 1990s, but it has not been established as a standard procedure. This may be because the success of this procedure largely depends on the technical competence of an assistant to secure an adequate field of view during the procedure. Thoracoscopic esophagectomy with the patient in the prone position has recently been introduced and has been consistently shown to be useful. Compared with left lateral thoracoscopic esophagectomy, prone thoracoscopic esophagectomy requires less assistance in exposing the operative field and it is relatively easy to obtain a satisfactory field of view. We performed prone thoracoscopic esophagectomy on 20 patients and were successful in achieving a wide field of view. The postoperative course was remarkably favorable in all patients and the procedure is considered promising for standard thoracoscopic esophagectomy. There are few detailed reports of this procedure; herein, we describe the procedure of prone thoracoscopic esophagectomy employed at our hospital.