Quantitative characterization of hydration state and destructuring effect of monosaccharides and disaccharides on water hydrogen bond network.

Terahertz time-domain attenuated total reflection measurements of monosaccharide (glucose and fructose) and disaccharide (sucrose and trehalose) solutions from 0.146 M to 1.462 M were performed to evaluate (1) the hydration state and (2) the destructuring effect of saccharide solutes on the hydrogen bond (HB) network. Firstly, the extent of hydration water was determined by the decreased amount of bulk water with picosecond relaxation time that was replaced by that with much longer orientational relaxation time. As a result, we found glucose and trehalose exhibits stronger hydration capacity than fructose and sucrose, respectively, despite of the same number of the hydroxyl groups. For each saccharide, the hydration number tended to decrease with solute concentration. Secondly, the destructuring effect of these saccharide solutes on the HB network of the surrounding bulk water was discussed from the perspective of the fraction of non-hydrogen-bonded (NHB) water isolated from the HB network. We found the fraction of NHB water molecules that are not engaged in the HB network monotonously increased with saccharide concentration, indicating saccharide solutes promote the disruption of the water HB network. However, no noticeable differences were confirmed in the fraction of NHB water between glucose and fructose or between sucrose and trehalose. In contrast to hydration number, the number of NHB water produced by a single saccharide solute was less dependent on solute concentration, and three monosaccharide/disaccharide solutes were found to produce one/two NHB water molecules.

Hydration and hydrogen bond network of water around hydrophobic surface investigated by terahertz spectroscopy.

Water conformation around hydrophobic side chains of four amino acids (glycine, L-alanine, L-aminobutyric acid, and L-norvaline) was investigated via changes in complex dielectric constant in the terahertz (THz) region. Each of these amino acids has the same hydrophilic backbone, with successive additions of hydrophobic straight methylene groups (-CH2-) to the side chain. Changes in the degree of hydration (number of dynamically retarded water molecules relative to bulk water) and the structural conformation of the water hydrogen bond (HB) network related to the number of methylene groups were quantitatively measured. Since dielectric responses in the THz region represent water relaxations and water HB vibrations at a sub-picosecond and picosecond timescale, these measurements characterized the water relaxations and HB vibrations perturbed by the methylene apolar groups. We found each successive straight -CH2- group on the side chain restrained approximately two hydrophobic hydration water molecules. Additionally, the number of non-hydrogen-bonded (NHB) water molecules increased slightly around these hydrophobic side chains. The latter result seems to contradict the iceberg model proposed by Frank and Evans, where water molecules are said to be more ordered around apolar surfaces. Furthermore, we compared the water-hydrophilic interactions of the hydrophilic amino acid backbone with those with the water-hydrophobic interactions around the side chains. As the hydrophobicity of the side chain increased, the ordering of the surrounding water HB network was altered from that surrounding the hydrophilic amino acid backbone, thereby diminishing the fraction of NHB water and ordering the surrounding tetrahedral water HB network.

Minimally invasive removal of a dislocated stent from the right atrium after previous CABG.

Repeat sternotomy after previous open heart operations constitutes a serious risk factor for cardiac injury, particularly in the presence of a patent internal thoracic artery. We report a case of successful minimally invasive removal of a dislocated subclavian vein stent entangled in the tricuspid valve in a patient 5 years after coronary artery bypass surgery.

Modulation of doxorubicin sensitivity by cyclosporine A in hepatocellular carcinoma cells and their doxorubicin-resistant sublines.

BACKGROUND AND AIMS: Cyclosporine A (Cys) and verapamil (Ver) sensitize multidrug-resistant (MDR) cells to various anticancer drugs by interacting with membrane glycoproteins involved in the drug efflux. In the present study, we assessed the effect of Cys on the modulation of doxorubicin (DOR) sensitivity in hepatocellular carcinoma (HCC) cell lines, and their DOR-resistant sublines. METHODS: The sensitivity to DOR and the chemosensitizing effects of Cys were assessed by using two human HCC cell lines, PLC/PRF/5 and Hep-3B, and their DOR-resistant sublines, PLC/DOR and 3B/DOR. The expression of multidrug resistance 1 (MDR1) and multidrug resistance-associated protein (MRP) mRNA in these cells were detected by using a RT-PCR. The HCC cell lines grown in individual wells of 24-well plates were incubated with DOR that were sequentially diluted in culture medium in combination with 5 micromol/L Cys for 24 h. The cell viability in each well was measured by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. RESULTS: The mRNA of MDR1 and that of MRP were readily detectable in the HCC cell lines by RT-PCR. When 5 micromol/L Cys was added to the culture, the 50% inhibiting concentration (IC50) of DOR was reduced from 0.93 +/- 0.29 microg/mL to 0.32 +/- 0.10 microg/mL in PLC/PRF/5, and from 0.25 +/- 0.07 microg/mL to 0.09 +/- 0.04 microg/mL in Hep-3B. Furthermore, in the presence of 5 micromol/L Cys, the IC50 of DOR was reduced from 48.63 +/- 17.04 microg/mL to 0.49 +/- 0.14 microg/mL in PLC/DOR, and from 4.60 +/- 1.22 microg/mL to 0.15 +/- 0.06 microg/mL in 3B/DOR. The amounts of PCR products of MDR1 mRNA in PLC/DOR and 3B/DOR were greater than those in PLC/PRF/5 and Hep-3B, respectively. CONCLUSIONS: In HCC, the amplification of MDR1 mRNA is probably the main mechanism underlying acquired DOR resistance. Cyclosporine is also indicated to be highly active in potentiating the anticancer activity of DOR in HCC cells and their DOR-resistant sublines.

Increase in CD95 (Fas/APO-1)-positive CD4+ and CD8+ T cells in peripheral blood derived from patients with autoimmune hepatitis or chronic hepatitis C with autoimmune phenomena.

BACKGROUND: The expressions of CD95 (Fas/APO-1) and Bcl-2 are determinants of apoptosis in normal lymphocytes, and abnormalities in their expressions might contribute to the induction of autoimmunity. In this study, we examined the expressions of CD95 and Bcl-2 on freshly isolated T and B cells from patients with autoimmune hepatitis (AIH) or chronic hepatitis C associated with autoimmune phenomena (CH-C(AI)). METHODS: The CD95 and Bcl-2 expressions within CD4+ T, CD8+ T, and CD19+ B cell subsets were analysed by two-colour flow cytometry. RESULTS: The surface expression of CD95 was significantly high in both the CD4+ T and CD8+ T cell subsets derived from the patients with AIH and those with CH-C(AI), compared with expression in patients with CH-C and normal subjects. The increase in CD95 expression was associated with the phenotypic conversion of naive CD45RO- to primed CD45RO+ CD4+ T cells. Bcl-2 was detected in the vast majority of peripheral T and B cells. There was no significant difference in the percentage of Bcl-2-positive cells in the CD4+ T cell, CD8+ T cell and CD19+ B cell subsets among the patient groups and normal subjects. CONCLUSIONS: These results indicate that an increase in CD4+ T cells expressing CD45RO and CD95 marks an important subset of AIH and CH-C(AI) patients. These expanded CD95+ CD45RO+ primed T cells most likely reflect a continuous antigen-specific or non-specific activation of T lymphocytes, and/or the persistent presence of activated lymphocytes as a consequence of abnormalities in the peripheral deletion of activated lymphocytes. These persistently activated lymphocytes might play a role in the induction of autoimmunity in AIH and CH-C(AI).

[Emergent coronary artery bypass grafting within twenty-four hours following acute myocardial infarction].

We experienced 43 patients with acute myocardial infarction who underwent emergent coronary artery bypass grafting within twenty-four hours from the onset. Twenty-six patients (group S) were in cardiogenic shock preoperatively and fourteen patients of this group had total or subtotal obstruction of the left main trunk. Fourteen of the other seventeen patients (group N) had a left main trunk disease. More patients underwent PTCA and the time required for reperfusion of the infarction-related coronary artery with PTCA was shorter in group S than group N. Preoperative hemodynamics improved in twenty patients in group S. The time required for completion of a coronary artery bypass to the infarction-related coronary artery was also shorter in group S. The operative mortality was 15% in group S and 6% in group N. One noncardiac late death occurred in group S. The postoperative segmental wall motion score of the infarcted left ventricle was much improved in patients with subtotal occlusion of the infarction-related coronary artery. Thus, preoperative hemodynamic improvement by early reperfusion leads to satisfying operative results and salvage of the infarcted myocardium.

[Emergent operation for acute Stanford type A aortic dissection].

Results of emergent surgery for acute Stanford type A aortic dissection are still poor. We reviewed our cases to find out how we could ameliorate surgical results. In the past five years, 36 patients with type A aortic dissection underwent emergent surgery. The operation was started within six hours from the onset of symptoms in 16 patients. The extent of aortic replacement was just beyond the entry-bearing portion. The operation was performed with the aid of open distal anastomosis and selective cerebral perfusion. Operative death occurred in one patient. Postoperative complications developed frequently. Respiratory failure, renal dysfunction and low cardiac output syndrome were most frequent. Their co-risk factor was perioperative bleeding which was related to young age, long operation time, arch replacement, additional procedure and failure of the entry site resection. Some modification of the suturing method might reduce hemorrhage. Prompt surgery following the diagnosis and appropriate selection of surgical tactics and anastomosis technique in order to reduce bleeding is essential to improve surgical results of acute type A aortic dissection.

[Tricuspid valve closure for pulmonary atresia with intact ventricular septum].

Tricuspid valve closure was performed on four children who had pulmonary atresia with intact ventricular septum. All of them had major right ventricle-coronary communications and severely hypoplastic right ventricle under 30% of normal right ventricle volume. Their coronary circulations were not right ventricle dependent. All of four patients survived tricuspid valve closure. Three children were performed Fontan procedure. One child, with severe change in her coronary arteries preoperatively, once improved her myocardial ischemia in early stage after tricuspid valve closure, however, the myocardial ischemia progrssed in one year later and died suddenly three years and five months after tricuspid valve closure. Three survivors remained good condition in their left ventricle function postoperatively. In this study, we investigated changes in LVEF, LVEDVI, LVEDP and mitral regurgitation as indicators of left ventricle functions through tricuspid valve closure. It revealed that tricuspid valve closure had advantages in preservation of left ventricle function and in preparation for Fontan procedure consequently.

A case of traumatic pseudoaneurysm of the ascending aorta occurring in a postoperative patient who underwent arch replacement and Bentall's operation.

A case of traumatic pseudoaneurysm of the ascending aorta occurring in a postoperative patient who underwent an arch replacement and Bentall's operation was reported. A bleeding point was clear at the graft of the ascending aorta, and a pseudoaneurysmal formation was suspected following an echocardiogram. An aortogram demonstrated the presence of an aneurysm approximately 8 cm by 4 cm in size originating 5 cm above the right coronary ostia. An emergency operation was carried out. A Trans-femoral bypass was established before sternotomy. The Operative findings showed that adhesive connective tissue covered a pseudoaneurysm 8 cm by 4 cm in size, and that there was a tear in the anastomosis of the grafts between the ascending aorta and the arch 5 cm above the coronary ostia. Direct suture was performed, using hypothermic circulatory arrest. In this paper, We discuss the mechanism, classification, and operative strategy of traumatic pseudoaneurysm.

Retrospective analysis of the multidisciplinary treatment for 534 hepatocellular carcinoma patients over a 12-year period.

Multidisciplinary treatments for 534 patients with hepatocellular carcinoma (HCC) over a 12-year period from 1981 to 1992 were retrospectively studied. Cumulative survival curve of all patients showed a fine hyperbolic curve, and 1-year, 3-year-, 5-year survivals were 66, 33, and 18%, respectively. Survival of female patients was better than male patients, and survival of HBsAg-negative patients was better than that of HBsAg-positive patients. Several background factors such as the Child-Pugh classification, liver function tests or factors, number of tumors, and the size of the main tumor were analyzed, and each factor was related to survival. Survival curves of 3 treatments, hepatectomy, percutaneous ethanol injection (PEI), and transcatheter arterial embolization (TAE)+PEI, overlapped to a large degree. Also the survival curve of the more recent 6-year period from 1987 to 1992 was better than that of the earlier 6-year period from 1981 to 1986.

[A case of surgical treatment of acute aortic dissection without an intimal tear].

We experienced a case of acute aortic dissection without an intimal tear. A 55-year-old woman with SLE presented with acute chest pain. TEE study showed dissection of the ascending aorta, and accompanied by pericardial effusion. An emergency operation was performed four hours after onset. Intraoperatively, thrombus was encountered in the false lumen of the ascending aorta and the proximal arch. However, intimal tear was not found. She underwent graft replacement of the ascending aorta and the total aortic arch, and had an uneventful postoperative course. Histological examination of a segment of ascending aorta showed no evidence of mucinous degeneration and pathological rupture of the elastic fiber.

[Pericardial effusion following surgery using cardiopulmonary bypass].

Of 156 patients who underwent cardiac or aortic surgery using cardiopulmonary bypass, postoperative pericardial effusion was detected in 89 patients (57%). They were divided into four groups according to the size of pericardial effusion: No effusion (group N, n = 66), small effusion (group S, n = 42), moderate effusion (group M, n = 22) and large effusion (group L, n = 25). In group L, 68% of patients had symptoms and 44% had complications such as subxiphoid drainage and constrictive pericarditis. Fewer patients with perioperative pleurotomy were found in group L than group N (p < 0.05). Postoperative anticoagulation did not affect the size of pericardial effusion. Postoperative amount of drainage were larger in groups, S, M, L than group N (p < 0.05, p < 0.05, p < 0.005). The CRP reelevation rate of each group was equal but the maximum CRP value was higher in group L than group N (p > 0.05). These results suggest that some relationship exists among postoperative drainage, inflammatory response and postoperative pericardial effusion. Since large pericardial effusion is often symptomatic and accompanied by various complications, earlier detection of pericardial effusion and appropriate treatment seems to be essential.

A case of isolated acute DeBakey II redissection occurring in a postoperative survivor who underwent an arch replacement for acute DeBakey IIIb dissection.

A case of isolated acute DeBakey II redissection which occurred in a postoperative survivor who underwent an arch replacement for acute DeBakey IIIb dissection is reported. The operative findings revealed that there was an intimal tear above the left coronary cusp, that there was a false lumen in the native ascending aorta, and that a residual false lumen caused by the initial operation had not been detected. Redissection caused mainly by the operative procedure, such as the failure to include the site of the intimal tear in the original repair and the formation of a new dissection as a result of anastomotic failure, is frequently seen. However, isolated redissection is a rare condition. In this paper we discuss classification, diagnosis and treatment of redissection.

[A case report of modified Bentall procedure, aortic arch replacement and mitral valve replacement for a patient with Marfan's syndrome].

A 20-year-old man of Marfan's syndrome who had mitral valve regurgitation, annuloaortic ectasia with aortic valve regurgitation and aortic arch aneurysm was successfully treated with radical operation. Mitral valve replacement was performed with superior wall incision of the left atrium directly. Complete transection of the aortic root made it easy to reach the mitral valve. The diameter of his ascending aorta was 70 mm, and modified Bentall' procedure, Carrel patch method, was performed. Aortic arch was 40 mm in diameter, and total aortic arch replacement was performed under hypothermic circulatory arrest. After the combined operation, patient was recovered uneventfully.

[Modified Fontan procedure for complex cardiac anomaly with nonconfluent pulmonary artery].

Modified Fontan procedure was successfully performed in two patients with complex cardiac anomaly and nonconfluent pulmonary artery. A nonconfluent portion of the pulmonary artery was interposed with a xenopericardial roll. In one patient, the central pulmonary artery was completely absent. Two-staged reconstruction of the central pulmonary artery was carried out through a left thoracotomy and a median sternotomy before the Fontan procedure. In the other patient, a juxtaductal segment of the pulmonary artery was nonconfluent. Correction of the nonconfluent pulmonary artery was performed concomitantly with the Fontan procedure. Fenestrated Fontan procedure seemed to be the beneficial modification for survival. Both patients have been day well during the midterm follow-up period.