Yuichiro Matsuura

Correlating telomerase activity levels with human neuroblastoma outcomes

Telomerase activity was analysed in 100 neuroblastoma cases. Although telomerase activity was not detected in normal adrenal tissues or benign ganglioneuromas, almost all neuroblastomas (94%) did express it, suggesting an important role for telomerase in neuroblastoma development. Neuroblastomas with high telomerase activity had other genetic changes (for example, N-myc amplification) and an unfavourable prognosis, whereas tumours with low telomerase activity were devoid of such genetic alterations and were associated with a favourable prognosis. Three neuroblastomas lacking telomerase activity regressed (stage IVS). Thus telomerase expression may be required as a critical step in the multigenetic process of tumorigenesis, and two different pathways may exist for the development of neuroblastoma.

Simple left atrial procedure for chronic atrial fibrillation associated with mitral valve disease

BACKGROUND A computerized 48-channel mapping system was used to investigate the characteristics of an atrial epicardial electrogram during chronic atrial fibrillation (AF) in patients with solitary mitral valve disease. We have devised a simple left atrial procedure to eliminate the chronic AF during a mitral valve operation. METHODS Using this mapping system, we performed intraoperative atrial mapping in 11 patients with chronic AF associated with mitral valve disease. The AF duration ranged from 0.4 to 15 years (mean, 8.0 +/- 4.5 years). A simple surgical ablation of the AF on the left atrium only was performed during the mitral valve operations. RESULTS The mean AF cycle length of the atria ranged from 129 to 169 milliseconds in the right atrium and from 114 to 139 milliseconds in the left atrium. The mean AF cycle length of the left atrium was shorter than that of the right atrium. Regular and repetitive activation was found in the left atria of 7 of 11 patients. The AF disappeared in all patients immediately after the operation, and 10 of these patients continued to have a sinus rhythm postoperatively (AF-free rate, 91%). CONCLUSIONS Computerized intraoperative mapping revealed a shorter mean AF cycle length in the left atrium. A simple left atrial procedure was effective in eliminating chronic AF associated with solitary mitral valve disease.

Efficacy of a simple left atrial procedure for chronic atrial fibrillation in mitral valve operations.

BACKGROUND We have devised a simple surgical procedure to be performed on the posterior wall of the left atrium for the treatment of chronic atrial fibrillation (AF) associated with mitral valve disease. The effectiveness of this procedure for serial mitral valve operations was then evaluated. We postulated that chronic AF associated with mitral valve disease could be attributable to a distended left atrium. The refractory period of the distended left atrium was significantly shorter in the left posterior atrial wall, especially at the base of the left atrial appendage and at the orifice of the left posterior pulmonary vein. We hypothesized that the left posterior atrial wall with its shorter fibrillatory cycle length would act as a driver for maintaining the AF, and therefore, surgical ablation of this critical area in the left atrium could terminate the chronic AF. METHODS The surgical patients were divided into two groups. In group 1 (control group), 15 patients with chronic AF were operated on by the mitral valve procedure only. In group 2, 36 patients underwent this procedure in combination with a concomitant mitral valve operation. The disappearance rate of the AF was estimated by electrocardiography, and atrial function was estimated by transthoracic and transesophageal echocardiography. RESULTS The chronic AF had been reduced significantly or eliminated at discharge in 4 of 15 patients (26.7%) in the group 1, versus 31 of 36 patients (86%) in group 2 (p < 0.05). In group 2, 29 of the 31 patients (94%) whose AF had disappeared recovered the atrial kick of their right atrium, and 21 patients (22/31; 71%) recovered the atrial kick of their left atrium. CONCLUSIONS Surgical ablation of the posterior wall of the left atrium was effective in the treatment of chronic AF associated with mitral valve disease. This simple procedure could restore a sinus rhythm and also recovered atrial systolic function. We conclude that the left atrium may act as a driver for sustaining AF in mitral valve disease.

Surgical correction of aneurysm of the sinus of Valsalva: A Report of forty-five consecutive patients including eight with total replacement of the aortic valve

Abstract Pathologic, diagnostic and therapeutic aspects of 45 patients with an aneurysm of the sinus of Valsalva are discussed. The surgical procedure must be individualized for a patient according to the pathologic situations when fibrotic or prolapsing aortic cusps are encountered. Three choices are available in the surgical correction of this lesion: simple circumferential Teflon patch, circumferential sandwiched Ivalon-Teflon patch and, finally, prosthetic replacement of the aortic valve after a patch. The presence of fibrotic prolapsing aortic cusps will dictate the choice of valve replacement, while the prolapse alone may be corrected by means of sandwiched patch technic.

Clinical analysis of results of a simple left atrial procedure for chronic atrial fibrillation.

BACKGROUND We have performed a simple left atrial procedure for eliminating chronic atrial fibrillation (AF) associated with mitral valve disease. This article analyzes the midterm results of this procedure. METHODS Thirty-two patients were enrolled in this study concomitant with mitral valve operations. Patients were divided into two groups (AF- and AF+). We examined the efficacy of this operation and atrial function for more than 12 months of follow-up. RESULTS In a total of 98.5 patient years of follow-up, AF was absent 3 years after operation in 74%. Of preoperative and intraoperative variables, only long duration o

Surgical management of tracheal agenesis

Tracheal agenesis is a rare congenital malformation that usually is fatal. This report describes our experience in two such cases. In both cases, the diagnosis was suspected at birth, because the patients had respiratory distress without an audible cry and were difficult to intubate. A gastrostomy and banding of the abdominal esophagus provided effective initial stabilization, in conjugation with respiratory management. The first patient also had complex cardiac malformations, and the infant died of cardiac failure 1 week after birth. The second infant, who had tracheal agenesis with a proximal tracheoesophageal fistula and a bronchoesophageal fistula, was managed successfully. At 9 months of age, a tracheotomy was performed, a long T tube was inserted to maintain the airway patency beyond the proximal tracheoesophageal fistula, and the patient was discharged. At 3 years of age, esophageal reconstruction was performed with a colonic interposition graft. The patient is thriving and developing normally at 4 years of age. Diagnosis at birth and maintenance of airway patency are essential for successful management of tracheal agenesis. Initial surgical interventions are palliative but lifesaving. Subsequent management focuses on improving the quality of life and allowing swallowing and speech.

Telomerase activity as a marker of breast carcinoma in fine-needle aspirated samples

Telomerase activity in breast fine‐needle aspiration (FNA) samples may have diagnostic utility. The purpose of this study was to compare in FNA samples of breast tumor the diagnostic accuracy as correlated with histologic final diagnosis.

Endovascular stent-grafting via the aortic arch for distal aortic arch aneurysm : an alternative to endovascular stent-grafting

OBJECTIVE We have experienced transaortic stent-grafting for treating distal arch aneurysm or type B dissection. This paper is to mainly report the surgical aspect of these procedures. METHODS Fifteen patients underwent this surgery, including 12 men and three women ranging from 47 to 83 years. Twelve had aneurysms and three aortic dissection. Concomitant surgery was necessary in seven patients (coronary artery bypass grafting in five, tricuspid annuloplasty in one, and replacement of ascending aorta and/or total arch replacement in three cases). A stent graft (Gianturco Z-stent and Intervascular prosthesis) was loaded in a 30-F sheath catheter. Under circulatory arrest, selective cerebral perfusion was established, and the sheath catheter was inserted through aortotomy into descending aorta and the stent graft was deployed at an appropriate level. The proximal end of graft was sutured to the aorta just distal to the left subclavian artery with inclusion method at the posterior wall. Concomitant surgery was done during cooling or rewarming period. TEE was utilized to visualize every endovascular manipulation to avoid unintended intimal injury or misplacement of graft and to assess the surgical results in the operative theater. RESULTS Aneurysm was successfully excluded except in one patient who had a proximal endoleak and distal endoleak due to underestimation of aortic diameter. There was one operative mortality caused by cerebral infarction, possibly due to debris from femoral arterial cannulation. In the remaining patients, there was no enlargement of residual aneurysm. The excluded aneurysmal sac gradually regressed and disappeared within 2 years in five patients and the thrombosed false lumen completely shrunk within 1 year in two patients. One patient had paraplegia, possibly because the graft was intentionally advanced deeply to cover the thick and fragile atheromatous layer in order to avoid destruction of the atheroma by an expanded graft. CONCLUSIONS Endovascular stent graft via the aortic arch is an acceptable treatment for distal arch aneurysms close to or involving left subclavian artery or type B dissections, especially for those cases requiring other cardiac procedures. It can lead to regression and disappearance of aneurysm or dissection in the mid-term follow-up.

Endovascular stent-grafting through the aortic arch: an alternative approach for distal arch aortic aneurysm

BACKGROUND Endovascular stent-grafting is an innovative procedure; we have developed a novel approach to treat distal arch aortic aneurysm through a small incision in the aortic arch. METHODS Eight patients with thoracic aortic aneurysms were treated with an endovascular stent-graft that was introduced into the thoracic aorta through a small incision in the aortic arch. Of these patients, 7 had distal arch aortic aneurysms, and 1 had chronic aortic dissection of Stanford type B. Four of these patients had received concomitant coronary artery bypass grafting, and 1 patient had undergone tricuspid valvular annuloplasty. The stent-graft was introduced into the distal arch aorta and descending aorta through a small incision in the aortic arch, under selective cerebral perfusion and hypothermic circulatory arrest. RESULTS The selective cerebral perfusion time ranged from 52 to 86 minutes (mean, 68 minutes) and the operating time from 289 to 422 minutes (mean, 318 minutes). There was no endoluminal leakage into the aneurysm. Seven patients survived and were discharged, but 1 patient suffered a cerebral infarction and died during the follow-up period. CONCLUSIONS Placing an endovascular stent-graft through the aortic arch is an acceptable alternative treatment for distal arch aortic aneurysms.

Kupffer Cell Function in Ischemic and Nonischemic Livers After Hepatic Partial Ischemia/Reperfusion

Abstract Hepatic partial ischemic/reperfusion (I/R) injury, in which ischemic and nonischemic areas of the liver are likely to respond to each other after reperfusion, often occurs following hepatobiliary surgical procedures. Kupffer cells (KCs) are considered to play a major role in hepatic I/R injury. To study the activation of KCs in ischemic and nonischemic liver tissues following hepatic I/R, we investigated the superoxide generation and proinflammatory cytokine production of KCs in both liver parts in a rat model of partial hepatic I/R injury. KC superoxide generation in the ischemic and nonischemic lobes was upregulated 6 and 24 h after reperfusion, respectively, and then accelerated. The production of interleukin-1β (IL-1β) by KCs in the ischemic lobes increased during the early and late phases, 6 h and 48–72 h after reperfusion, respectively. A late increase in IL-1β production was also observed in the nonischemic lobes. Production of tumor necrosis factor-α (TNF-α) increased 6–24 h after reperfusion in both lobes. Upregulation of IL-1β mRNA in the ischemic lobes preceded the upregulation of TNF-α mRNA in both lobes. The hepatic partial I/R process results in activation of KCs in ischemic and nonischemic areas of the liver. The KCs are activated during the early phase after reperfusion in the ischemic areas, followed by activation in both the ischemic and nonischemic areas. This could be a cause of liver dysfunction after partial hepatic I/R during surgery.