[Surgical treatment for thoracoabdominal aortic aneurysm].

Spinal cord injury such as paraparesis and paraplegia remains one of the major concerns in surgery on the thoracoabdominal aortic aneurysm (TAAA). We utilize spinal cord protection including cerebrospinal fluid drainage (CSFD), adjuncts of aortic distal perfusion, reconstruction of the intercostal or lumbar arteries and deep hypothermia in TAAA repair. This report describes the results of surgical treatment for TAAA including postoperative neurological outcome. Between October 1999 and January 2004, 33 patients (mean age 66 years; range 26 to 81) underwent TAAA repair. Adamkiewicz artery could be detected using magnetic resonance angiography in 9 patients. CSFD was done in 20 patients. TAAA repair was achieved using adjuncts of aortic distal perfusion in 31 patients (partial cardiopulmonary bypass: 19, deep hypothermia: 9, left heart bypass: 3). We tried to reconstruct the intercostal or lumbar arteries which were located between Th8 and L2 as possible. Twenty-five patients underwent reconstruction of the intercostal or lumbar arteries. There were 6 hospital deaths. Postoperative spinal cord injury occurred in 4 patients (paraparesis: 1, paraplegia: 3). This clinical experience demonstrates that current technical strategies enable patients to undergo TAAA repair with acceptable early survival. However, despite aggressive spinal cord protection, few patients suffered from postoperative spinal cord injury. Future research should focus on spinal cord protection in patients with TAAA.

[Aortic valve-sparing root reconstruction in Marfan syndrome].

The outcome of aortic valve-sparing root reconstruction in Marfan syndrome was reviewed. Thirteen patients with Marfan syndrome underwent aortic valve-sparing root reconstruction for annuloaortic ectasia or aortic root dissection between 1994 and 1999. The grade of preoperative aortic regurgitation was I in 4, II in 2, III in 5, IV in 2 patients. The procedures of aortic valve-sparing were reimplantation in 7 and remodeling in 5 patients. There was no hospital and late death. Recurrence of aortic regurgitation greater than moderate grade developed in 1 patient immediately after the surgery and in the other 4 patients in the late stage. One patient of them required aortic valve replacement for it. Aortic valve-sparing root reconstruction is applicable in Marfan patients, although the indication should be cautious. Close observation is needed for recurrence of aortic regurgitation.

Ruptured left ventricular pseudoaneurysm penetrating into the left pleural cavity.

We experienced a rare case of ruptured left ventricular pseudoaneurysm penetrating into the left pleural cavity. A 77-year-old woman was first diagnosed with unstable angina due to sudden chest pain onset and abnormal electrocardiographic findings. In 2 days, massive left pleural effusion was recognized by chest X-ray, though subsequent computed tomographic scans did not show any aortic pathology. We observed her with left thoracentesis alone. Two days later, cardiac arrest suddenly occurred and emergency surgery was undertaken after resuscitation by percutaneous cardiopulmonary support. In surgery, a moderate amount of intrapericardial hematoma caused by rupture of a left ventricular pseudoaneurysm penetrating into the left pleural cavity was found and successfully repaired. This rare rupture of a left ventricular pseudoaneurysm penetrating into the left pleural cavity generated massive hemo-hydrothorax.

An analysis of risk factors of perioperative bleeding in surgical repair of abdominal aortic aneurysm.

BACKGROUND: In surgical repair of abdominal aortic aneurysm (AAA), excessive bleeding which causes postoperative complications is sometimes observed. To determine the risk factors of perioperative excessive blood loss, this retrospective study was performed. METHODS: Design. A retrospective study. Setting. An academic medical center. Participants. One hundred and forty patients underwent elective surgical repair of an abdominal aortic aneurysm (AAA) at our institution from 1995 through 1997. Measurements. The present study includes critical review of 140 consecutive charts of patients undergoing elective surgical repair of AAA. Preoperative laboratory data, intraoperative data and amount of blood loss to identify risk factors of perioperative blood loss. Factors which were found to be significantly associated with the amount of perioperative blood loss were preoperative plasma fibrin degradation product (FDP) level (r=0.445), amount of immediate re-infusion of shed blood (r=0.438), and duration of operation (r=0.411). RESULTS: Preoperative fibrinogen level correlated with perioperative blood loss little (r=-0.187). Preoperative platelet count or the other coagulation profile did not affect the amount of perioperative blood loss. The patients whose preoperative FDP were more than 40 microg x ml(-1) significantly increased the risk of excessive blood loss compared with less than 40 microg x ml(-1). CONCLUSIONS: The significant preoperative risk factor of perioperative blood loss was only FDP level in present study. Especially, the patients whose preoperative FDP were more than 40 microg x ml(-1) increased the risk of excessive blood loss.

Structural study of anhydrous tendon chitosan obtained via chitosan/acetic acid complex.

The molecular structure and packing arrangement of anhydrous tendon chitosan was determined by the X-ray fibre diffraction method together with the linked-atom least-squares refinement technique. The specimen was prepared from chitosan/acetic acid complex which was obtained by exposing tendon chitosan to acetic acid vapour at room temperature for several days. There is high degree of orientation and crystallinity compared with the specimen obtained by the annealing method. Two chitosan chains are present in an orthorhombic unit cell of dimensions a = 8.26(2), b = 8.50(1), c (fibre axis) = 10.43(2) A and space group P2(1)2(1)2(1). The 2-fold helical chain is stabilised by O3 triple bond O5 hydrogen bond with the gt orientation of O6. There are direct hydrogen bonds (N2 triple bond O6) between adjacent chains along the a-axis, which makes a sheet structure parallel to the ac-plane. On the other hand, no hydrogen bond is found between the sheets.

Pathogenesis of Babesia caballi infection in experimental horses.

The present study was designed to investigate the role of cytokines in the pathogenesis of Babesia caballi in experimentally infected horses. The expression of cytokine mRNA was determined by using reverse transcription-polymerase chain reaction in two B. caballi-infected horses for 2 weeks after the infection. In one horse, there was up-regulation of interferon-gamma, tumor necrosis factor-alpha (TNF-alpha) and interleukin-2 mRNAs, while in the second horse, expression of only TNF-alpha mRNA was up-regulated. No change was observed in interleukin-4 mRNA in both of the horses. To know the relation between nitric oxide (NO) production and pathogenesis, NO production was assayed in three dexamethasone treated-B. caballi-infected horses. Production of NO in all 3 horses increased significantly before death, although the parasitemia level remained very low. Treatment with NO inhibitor resulted in the suppression of NO production and increased parasitemia level in a horse, which died of the infection. The pathological examination showed that the main cause of the death was dyspnoea and pulmonary edema. Histopathologically, diffuse global mesangial proliferative glomerulonephritis was also observed. These results suggested that NO may be a critical effector molecule of immune defense against parasite. TNF-alpha and NO might be contributing to the pathogenesis in B. caballi infection.

[Effects of myocardial protection with ryanodine, measured with the intracellular calcium fluprescent indicator Fura-2].

The effects of Ryanodine, an inhibitor of salcoplasmic reticulum function, was investigated in isolated hearts of the Wistar rat strain. The cytosolic calcium was measured with the intracellular Ca2+ fluorescent indicator Fura-2. After 3 minutes perfusion of various cardioplegic solution which were added potassium (the concentration; 20 mmol/L) and four Ryanodine groups (1, 4, 10, and 20 nmol/L), these were obtained cardiac arrest. The arrested hearts were kept at 37 degrees C (normothermia) measuring hemodynamic studies. Hemodynamic parameters were heart rate, LVDP, LV dp/dt, coronary flow, and the intracellular calcium fluorescents which were calculated intracellular Ca2+. The significant difference was not noted in LVDP, but comparable improvement was achieved with Ryanodine groups (p < 0.05; 20 nM vs 0 nM). Other cardiac functions were likely same as above. The cytosolic calcium concentration of Ryanodine groups was depressed during cardiac arrest, it was 97.4 +/- 17.2% at the end of cardiac arrest, and it was slowly increased to 161.9 +/- 46.9% after 40 minutes reperfusion. On the other hand, that of the control group was higher than Ryanodine groups at every measuring points about two times. There was significant difference between both groups (p < 0.01). Concequently these phenomena caused that Ca2+ handling in the salcoplasmic reticulum were supressed by Ryanodine and the contractile function was recovered for that reason.

Identification of B cell epitopes of a 30 kDa Babesia equi merozoite surface protein.

A 30 kDa immunodominant surface antigen (p30) of Babesia equi has been used as a diagnostic antigen. The B cell epitopes on this molecule recognized by horse sera and monoclonal antibody (MAb) against p30, 36/133.97, were determined. A synthetic peptide of p30 with amino acid sequence of 123FYQEVLFKGFEAV135 exhibited strong positive reaction with the infected horse sera. In contrast, MAb 36/133.97 recognized different region of p30, as peptide synthesized with amino acid sequence of 27ASGAVVDFQLESI39 reacted strongly. In competitive inhibition ELISA, the binding of MAb 36/133.97 to recombinant p30 was inhibited by horse antibodies, although they did not recognize same or an overlapping epitope. The data on B cell epitopes in this study may be important in improving serodiagnostic methods of B. equi infection.

Partial protection of severe combined immunodeficient mice against infection with Babesia microti by in vitro-generated CD4+ T cell clones.

Because CD4+ T cells were considered to be involved in protection against infection with Babesia microti, specific CD4+ T cells were generated in vitro from recovered BALB/c mice and their protective activity was tested in vivo. The cells produced varying amounts of interferon (IFN)-gamma in vitro in response to parasite antigen. In passive transfer experiments, three out of eleven T cell clones tested exerted protective activity in the early phase after infection. However, there seemed to be no correlation between this protection and in vitro IFN-gamma production by the T cell clones. Although the protection was partial and short-lived, the result provided direct evidence that CD4+ T cells play a crucial role in defense against B. microti.

[A case of giant mesothelioma from visceral pleura which has feeding artery from pulmonary artery].

55-year-old woman was admitted to our hospital for cough. Chest X-ray films showed a giant tumor shadow in right anterior pleural cavity. Pulmonary arteriography showed a feeding artery from the branch of right superior trunk. We diagnosed the tumor might be mesothelioma from visceral pleura with stalk. We operated the patient and the tumor was turned out to be mesothelioma pathologically. The patient had a postoperative re-expansion pulmonary edema and recovered in a week. She lives well without recurrence for 3 years 8 months.

[Effect of extracellular magnesium on reperfused rat heart and intracellular calcium concentration of the myocardium].

Isolated rat hearts were subjected to 30 min global ischemia followed 20 min reperfusion with various concentration of Mg2+ Krebs-Henseleit-bicarbonate buffer (KHB buffer) (Mg2+:1.2 mM, 2.5 mM, 5 mM, 10 mM) and 20 min reperfusion with original KHB buffer (Mg2+:1.2 mM) at 37 degrees C, respectively. Cardiac function and the incidence of ventricular arrhythmia were measured during pre-ischemia and reperfusion, and intracellular Ca2+ concentration was measured during pre-ischemia, ischemia and reperfusion period. The hearts reperfused with 1.2 mM Mg2+ presented a significantly higher frequency of ventricular fibrillation (VF) and ventricular tachycardia (VT) than the other groups. Percent recoveries of LVDP (Left ventricular developed pressure) at the Mg2+ concentration of 1.2, 2.5, 5, 10 mM after 40 min reperfusion were 64.3 +/- 5.7%, 108.4 +/- 6.1%, 100.4 +/- 6.1%, 101.5 +/- 5.5%, respectively. Intracellular Ca2+ concentration of the hearts with Mg2+ 1.2 mM revealed 248.9 +/- 15.6% at reperfusion, and that the other groups did not increased during reperfusion. These data suggest that extracellular Mg2+ inhibits reperfusion arrhythmia and Ca2+ overload during reperfusion, and improves cardiac function of reperfused heart.

[A case of congenital cystic adenomatoid malformation of the lung in childhood].

A 2-year-old boy was admitted for elevation of infiltrative shadow in the left middle lung field on a chest X-ray. The clinical diagnosis was emphysematous bullae with inflammation of left upper lobe. He received chemotherapy with antibiotics prior to the operation. Left inferior lingual segmentectomy was performed on April 18, 1989. The histopathological examination of specimen revealed congenital cystic adenomatoid malformation (Stocker type II) of the lung. However, relapse of the CCAM was observed 3 years later. Left completion upper lobectomy was performed on December 8, 1992. The patient has been well for 30 months postoperatively.

[Myocardial protective effect of rapid cooling shock at reperfusion].

Hypothermia in a heart in which coronary circulation is sustained produces positive inotropism of the myocardium. The effects on cardiac function and intracellular Ca profile of rapid cooling shock (RCS) immediately after reperfusion were evaluated in terms of their ability to inhibit the onset of myocardial stunning and to rapidly improve function. RCS administered to isolated hearts of Langendorff perfusion rats for 3 minutes induced positive inotropism after 32 +/- 4 seconds, with LV Developed Pressure (LVDP) increased a normal 120 +/- 10% (mean +/- SE, n = 16). Based on the result in which the positive inotropism was confirmed, an experiment using rats was performed as follows: after 30 minutes of ischemia at 37 degrees C, 25 degrees C or 10 degrees C, the hearts were reperfused for 1, 2 or 3 minutes and RCS was administered for 1, 2 or 3 minutes. LVDP was satisfactorily reversed early in rats treated with RCS for 3 minutes after 3 minutes reperfusion of the ischemic hearts at 25 degrees C. In this group, no significant change in Ca concentration in myocardial cells was observed at reperfusion: +/- 3% of the baseline level. Intracellular Ca overload at reperfusion and decreased intracellular Ca level, which have the effect of suppressing the CICR channel, which plays a role in Ca release into the sarcoplasmic reticulum at contraction, are important causative factors in the development of myocardial stunning, as are free radicals. RCS improved myocardial function rapidly because it inhibited change in Ca level.