[Surgical treatment of transposition of great arteries: the coronary buttons transfer using medially based trapdoor flaps].

The arterial switch operation (ASO) has become the primary surgical approach used for correction of transposition of the great arteries. All the prerequisites for a successful ASO were recognized in time and dealt with, which allowed general acceptation of the technique. We report on our technique for the procedure and the result to date. From January 1991 to January 2008, a total of 100 patients underwent ASO at our unit using medially-based trapdoor flap method. The neo-pulmonary artery (PA) was reconstructed using a single rectangular pericardial patch. The initial patient having intramural coronary artery died due to ischemic event after Aubert procedure. Three patients had re-right ventricular out flow tract repair (RVOTR) in a long-term follow-up period. There was no significant aortic insufficiency, no ischemic event and no lethal arrhythmia.

Radiation therapy of invasive thymoma.

Between 1978 and 1987, 30 cases of invasive thymomas were treated with radiotherapy after surgery. Surgical therapy consisted of total resection in 15 patients, subtotal resection in 1 patient, and biopsy in 14 patients. Myasthenia gravis (MG) was associated in nine patients (MG(+) group), but in 21 patients there was no evidence of myasthenia gravis (MG(-) group). Irradiation in the dose range of 30 to 58.7 Gy was delivered. The total average 5-year survival rate was 71.8%; it was 39.2% in MG(+) group and 78.3% in MG(-) group, though there was no significant statistical difference. Myasthenia gravis was well controlled by the tumorectomy and associated radiotherapy in 7 of the 9 patients. However, in 3 of 7 patients (42.9%) myasthenia gravis recurred at 2 years, 2 years and 7 months, and 5 years and 8 months after initial therapy. Total body irradiation of 2 Gy with 0.1 Gy fractions was administered for uncontrollable myasthenia gravis in one patient with marked improvement. Radiation therapy is an important therapeutic modality for unresectable malignant thymoma as well as for postoperative combined therapy. Total body irradiation may be an effective method to treat patients with otherwise resistant myasthenia gravis.

Interactions of alpha-chymotrypsin and Carlsberg subtilisin with methyl N alpha-acetyl-2-(alkylthio)-L-tryptophanoates.

Methyl N alpha-acetyl-2-(alkylthio)-L-tryptophanoates bearing different alkylthio groups were synthesized and employed as substrates for alpha-chymotrypsin and Carlsberg subtilisin in an attempt to investigate the properties of the hydrophobic pocket or cleft (S1 subsite) of the enzymes which accommodates the side-chain of the P1 amino acid residue of the substrates. The derivatives with ethylthio, 2-hydroxyethylthio, 2,3-dihydroxypropylthio, 2-aminoethylthio, carboxymethylthio, 2-carboxyethylthio, 1,2-dicarboxyethylthio, and 2-amino-2-carboxyethylthio (cysteinyl-S) groups were hydrolyzed by alpha-chymotrypsin but with kcat/Km values 4.6 to 15 times smaller than that of methyl N alpha-acetyl-L-tryptophanoate, due mainly to larger Km values. The glutathionyl derivative was only weakly bound to the enzyme. Analyses of the kinetic parameters suggested that the S1 pocket of alpha-chymotrypsin is rather more spacious than has been supposed and is able to interact flexibly with substrates so as to orient the scissile bond to the catalytic residues. On the other hand, none of the derivatives were hydrolyzed by Carlsberg subtilisin but they all inhibited the enzyme with Ki values which are generally smaller than the Km values for N alpha-acetyl-L-aromatic (modified aromatic) amino acid methyl esters. The S1 cleft of Carlsberg subtilisin interacts rather strongly with the derivatives but lacks the flexibility necessary for catalysis.

Properties of phospholipase A1/transacylase in the white muscle of bonito Euthynnus pelamis (Linnaeus).

The properties of phospholipase A1 (PLA1) obtained from the white muscle of bonito, Euthynnus pelamis (Linnaeus), were examined. The PLA1 activity had a pH optimum from 6.5 to 7.0 for phosphatidylcholine (PC), and calcium ion was not required. The optimum temperature was from 20 to 30 degrees C. When a fatty alcohol was used as an acceptor, a wax ester was produced by transferring a fatty acid at the sn-1 position of the donor's PC. The maximum production of lysophosphatidylcholine was shifted by 0.5 pH units to the acidic side and the pH optimum of wax ester synthesis was from 6.0 to 6.5. The synthesis was independent of calcium ion and Coenzyme A. The transacylation was also observed when 1-lyso-2-acyl-sn-glycero-3-phosphocholine was used as an acceptor. Fatty acid at the sn-1 position of the donor PC was transferred to the unoccupied hydroxy group of the acceptor at the sn-1 position. When 2,3-dipalmitoyl-sn-glycero-1-phosphocholine was used as the acyl donor, a similar amount of palmitic acid was transferred as in the case of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine. However, 1-acyl-2-lyso-sn -glycero-3-phosphocholine, a positional isomer, was a poor acceptor. These results indicate that the transacylation by the PLA1 from bonito muscle is not stereospecific, but is position-specific both for the acyl donor and acceptor.

Purification and amino acid sequence of basic protein II, a lysine-49-phospholipase A2 with low activity, from Trimeresurus flavoviridis venom.

A basic protein (pI 10.3), named basic protein II, was purified to homogeneity from the venom of Trimeresurus flavoviridis (Habu snake) after four chromatographic steps. The amino acid sequence of this protein was determined by sequencing the S-pyridylethylated derivative and its peptides produced by chemical (cyanogen bromide) and enzymatic (chymotrypsin, clostripain, and Staphylococcus aureus V8 protease) cleavages. The protein consisted of 122 amino acid residues and was found to be identical in sequence to basic protein I from the same source except that Asp-58 of basic protein I is replaced by asparagine. Like basic protein I, the structural feature of basic protein II is that Tyr-28 and Asp-49 common in phospholipases A2 from snake venoms and mammalian pancreas are replaced by asparagine and lysine, respectively. Thus, basic protein II belongs to the category of lysine-49-phospholipase A2. The action of basic protein II on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphorylcholine released only oleic acid, indicating that it has phospholipase A2 activity. Its molar activity toward 1,2-dilauroyl-sn-glycero-3-phosphorylcholine, however, was only 1.7% of that of T. flavoviridis phospholipase A2 isolated previously. Affinity for Ca2+ and reactivity toward p-bromophenacyl bromide of basic protein II were 8 and 5.3 times, respectively, smaller than those of phospholipase A2 from the same source, substantiating the low phospholipase A2 activity of basic protein II.

MR findings in two presumed cases of mild central pontine myelinolysis.

The authors describe two patients with presumed central pontine myelinolysis whose clinical symptoms were mild despite extensive intrapontine lesions evident on MR imaging. Enhancement of the lesions with Gd-DTPA was not observed in either case. It is suggested that the severity of findings on MR imaging does not necessarily reflect the severity of clinical symptoms of the disease.

Contrast enhancement of intracranial lesions: conventional T1-weighted spin-echo versus fast spin-echo MR imaging techniques.

BACKGROUND AND PURPOSE: The T1-weighted fast spin-echo (T1-FSE) MR imaging sequence is not used routinely, since the speed advantage is not as dramatic as it is in T2-weighted imaging. We evaluated the T1-FSE sequence to determine whether this technique can replace the conventional T1-weighted spin-echo (T1-SE) sequence for routine contrast-enhanced imaging. METHODS: Sixty-nine patients with intracranial enhancing lesions underwent both T1-SE and T1-FSE sequences in a random order after administration of contrast agent. Acquisition time was 55 seconds for the T1-FSE sequence and 2 minutes 38 seconds for the SE sequence. The conspicuity of enhancing lesions, peritumoral edema, and gray-to-white matter contrast as well as motion and flow artifacts were analyzed. Signal-to-noise ratios of enhancing lesions, gray matter, and white matter as well as contrast-to-noise ratios (CNRs) of enhancing lesions, with gray matter with white matter as the standard, were calculated. RESULTS: The conspicuity of enhancing lesions was better on T1-FSE sequences than on T1-SE sequences, although the difference in the CNRs of enhancing lesions did not reach significance. Images obtained with the T1-FSE sequence showed less flow and motion artifacts than did those obtained with the T1-SE sequence. The conspicuity of peritumoral edema and gray-to-white matter contrast was lower on the T1-FSE images than on the T1-SE images. CONCLUSION: The T1-FSE sequence reduces imaging time and has the potential to replace the conventional T1-SE sequence for the evaluation of enhancing lesions in the brain when time is a consideration.

Purification and amino acid sequence of basic protein I, a lysine-49-phospholipase A2 with low activity, from the venom of Trimeresurus flavoviridis (Habu snake).

A basic protein (pI 10.2), named basic protein I, was purified to homogeneity from the venom of Trimeresurus flavoviridis (Habu snake) after four chromatographic steps. The amino acid sequence of this protein was determined by sequencing the S-pyridylethylated derivative of the protein and its peptides produced by chemical (cyanogen bromide and formic acid) and enzymatic (chymotrypsin, Achromobacter protease I, and Staphylococcus aureus V8 protease) cleavages. The protein consisted of 122 amino acid residues and was similar in sequence to phospholipases A2 from the venoms of crotalid and viperid snakes. A most striking feature of this protein is that aspartic acid at the 49th position common in phospholipases A2 is replaced by lysine. When the protein acted on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphorylcholine, oleic acid was preferentially released, indicating that the protein has phospholipase A2 activity. Its molar activity toward 1,2-dilauroyl-sn-glycero-3-phosphorylcholine, however, was 1.5% that of T. flavoviridis phospholipase A2 isolated previously. The fact that both affinity to Ca2+ and reactivity to p-bromophenacyl bromide of basic protein I are approximately one order of magnitude lower than those of T. flavoviridis phospholipase A2 might explain the low activity of basic protein I.

Value of dynamic susceptibility contrast magnetic resonance imaging in the evaluation of intracranial tumors.

The degree of tumor malignancy generally correlates to tumor grade, and the direct measurement of tumor vasculature is desired. Dynamic susceptibility contrast magnetic resonance imaging can provide relative cerebral blood volume and, therefore, is one of the most reliable methods to evaluate tumor vasculature in vivo. Tumor vessel size is extremely variable due to complex tumor angiogenesis, and the gradient-echo echo-planar imaging (GE-EPI) technique, which is sensitive to the total vascular bed, is well suited for this purpose. As many studies have shown, dynamic susceptibility contrast magnetic resonance imaging is more useful for grading glioma than conventional magnetic resonance imaging. We found that this technique can also provide supplementary information to differentiate between malignant lymphoma and glioma because the absence of tumor neovascularization of malignant lymphoma leads to low rCBV, which is in contrast to those of malignant gliomas. Indeed, this technique can be used for the differentiation of extra-axial tumors such as between meningioma and neurinoma. Recently, this technique has been focused toward determining the stereotactic biopsy site, monitoring the embolization of effect in meningioma, or evaluation of treatment effects after radiation therapy. However, the value of tumor rCBV is affected by many conditions such as the T1 relaxivity effects of gadolinium in the extravascular space. To establish the usefulness of this technique, further examination will be needed.

Replacement of the tricuspid valve in children with congenital cardiac malformations.

BACKGROUND AND AIM OF THE STUDY: When replacing the regurgitant tricuspid valve in children, the decision to use either a bioprosthesis or a mechanical valve remains controversial. METHODS: The atrioventricular valve for the pulmonary circulation was replaced in 11 young patients aged between 8 months and 13 years. Complications of congenital cardiac malformation were present in seven patients, and Ebstein's anomaly in three; tricuspid valvular regurgitation was an isolated lesion in one patient. A bioprosthesis was implanted on seven occasions, and a bileaflet mechanical valve on eight, including re-replacement of the valve in four patients. RESULTS: One patient died two years after implantation due to respiratory problems. Tricuspid stenosis due to valve calcification occurred in four bioprostheses at between four and nine years after initial replacement (57%). In three of these cases the native valve leaflets had not been removed. Thrombosis occurred in one patient with a mechanical valve; rereplacement was successful. Anticoagulant-related hemorrhage occurred in another patient. Among patients receiving a mechanical valve, 83% of valves were dysfunction-free after five and ten years. CONCLUSION: When replacing an atrioventricular valve for the pulmonary circulation in children, we prefer to use a low-profile mechanical valve, especially when extensive repair of intracardiac malformation has been carried out, but ventricular function is good. In children with poor cardiac performance, a bioprosthesis is preferred, with total resection of the native valve leaflets.

Ventricular outflow tracts after Kawashima intraventricular rerouting for double outlet right ventricle with subpulmonary ventricular septal defect.

OBJECTIVE: To determine whether or not the ventricular outflow tracts can be efficiently constructed in patients with double outlet right ventricle with subpulmonary ventricular septal defect by the Kawashima intraventricular rerouting in which the morphologically right ventricular outlet is divided into two, one for the systemic and the other for the pulmonary circulations. METHODS: The intraventricular rerouting procedure was carried out in nine patients with this particular malformation. Age at repair ranged from 35 days to 3 years old. The distance between the attachments of the tricuspid and the pulmonary valves was 10 mm or greater in all except one patient in whom the measured value was 3 mm. Resecting subaortic musculature appropriately, a tailored patch, either oval-shaped (in seven) or heart-shaped (in two), was placed to construct an unobstructed channel for the left ventricular outflow tract with its diameter greater than that of the anticipated normal aortic orifice at the time of repair. For an unobstructed channel to the pulmonary arteries, enlargement of the right ventricular outflow tract was carried out using a patch in six. RESULTS: All patients survived the operative procedure. On postoperative catheterization, mean pulmonary arterial pressure was 15 +/- 8 mmHg, and cardiac index was calculated as 3.3 +/- 0.6 l/min per m2. It proved that the constructed left ventricular outflow tract can become larger in the longer term. Pressure gradient across the left ventricular outflow tract was greater than 20 mmHg in two patients in the intermediate term. One of these two underwent reoperation for the obstruction 10 years after the initial repair. It was suspected that use of a heart-shaped internal conduit, which seems to result from inadequate conal resection, was one of the possible causes of such obstruction in the longer term. Pressure gradient of 47 mmHg was seen across the right ventricular outflow tract in one patient, although this patient has undergone no reoperation. Enlargement of the right ventricular outflow tract could minimize postoperative obstruction for the pulmonary pathway. CONCLUSIONS: The intraventricular rerouting remains one of the attractive surgical options for repair in this particular setting, in terms of successful construction of the ventricular outflow tracts.

Establishment of total cavopulmonary connection without use of cardiopulmonary bypass.

OBJECTIVE: To minimize deleterious postoperative influences of cardiopulmonary bypass on the pulmonary circulation immediately after the Fontan type procedure, total cavopulmonary connection was achieved without use of cardiopulmonary bypass. METHODS: Since April 1996, 15 patients including five patients with visceral heterotaxy, in whom no intracardiac procedure was needed, have undergone this operative maneuver. Age at operation ranged from 1.2 to 44.6 years. Construction of a systemic to pulmonary shunt had been previously employed in seven patients, banding of the pulmonary trunk in two patients, and the Norwood procedure in one patient. The superior caval vein was initially anastomosed to the pulmonary arteries in bidirectional fashion under temporary bypass from the superior caval vein to the atrium. The channel for draining the inferior caval vein was subsequently constructed with the aid of temporary bypass from the inferior caval vein to the atrium, using a Goretex tube in ten patients, using a pedicled autologous pericardial roll in four patients, and directly anastomosing the pulmonary trunk to the orifice of the inferior caval vein in one patient. In patients with visceral heterotaxy and an independent hepatic venous drainage, redirection of the blood flow via the caval vein as well as the hepatic vein could be successfully achieved by placing dual temporary bypasses into these veins. RESULTS: Postoperative courses were excellent in all patients. Superior caval venous pressure was 11 +/- 2 mmHg at 12 h after the operation. No blood transfusion was needed in nine patients(60%). CONCLUSION: This alternative operative procedure is undoubtedly attractive when establishing the Fontan circulation in patients undergoing no intracardiac maneuvers.

Use of expanded polytetrafluoroethylene sutures as artificial tendinous cords in children with congenital mitral regurgitation.

OBJECTIVE: To determine the efficacy in the intermediate term of artificial cords inserted in children with congenital mitral regurgitation. METHODS: We reconstructed the tendinous cords using expanded polytetrafluoroethylene (ePTFE) sutures in 11 children with severe mitral regurgitation. In these patients, the aortic (anterior) leaflet of the mitral valve had been markedly prolapsed, the tendinous cords being partially lacking in seven, and elongated in the remaining four. In addition, one of the papillary muscles was hypoplastic in five and absent in three. The number of artificial cords constructed varied from two to six. Conventional annuloplasty was performed in all to plicate the dilated annular attachment of the valve. Ventricular septal defect was present in four patients, and other associated malformations in another two. Age at operation ranged from 9 months to 9 years old, with a mean of 4.5 years. RESULTS: All patients survived the operation. No reoperation has been needed thus far. No complications were encountered related to the use of the prosthetic materials or anticoagulation. As judged by echocardiography, regurgitation became trivial or slight immediately after the repair. In two patients, however, regurgitation recurred within 1 year of the operation. Coaptation between the leaflets was maintained by a compensatory growth at the site of attachment of the artificial cords. Catheterization demonstrated significant improvements in the end-diastolic volume of the left ventricle. CONCLUSION: Expanded polytetrafluoroethylene sutures can be used as artificial cords when attempting to repair the malformed mitral valve in children, providing excellent results in the short- and the intermediate-term after the surgical procedure.

Quantitative analysis of Gly m Bd 28K in soybean products by a sandwich enzyme-linked immunosorbent assay.

A sandwich enzyme-linked immunosorbent assay for the soybean allergen, which consists of a monoclonal antibody (D4) as the fixing (first) antibody and another peroxidase-conjugated monoclonal antibody (C5) as the second, has been developed. Both D4 and C5 monoclonal antibodies strongly bound to the guanidine/HCl-denatured allergen, Gly m Bd 28K. Therefore the samples used in the present experiment were extracted with sodium phosphate buffer (pH 8.0) containing 6 M guanidine and 10 mM 2-mercaptoethanol, then completely dialyzed against phosphate-buffered saline (PBS). The dialyzed samples were subjected to the assay. Various soybean products were observed to contain the allergen at high concentrations, such as soybean protein isolate (SPI), tofu, kori-dofu, and yuba, but its content in soy milk and abura-age were found to be low. In fermented products such as natto, soy sauce, and miso, and even in the processed foods with soybean protein isolate (SPI), the allergen was not detected. These results were also confirmed by an immunoblotting technique with D4.

MRI findings of hypothalamic hamartoma: report of five cases and review of the literature.

Hypothalamic hamartoma is a relatively rare congenital malformation, associated with the clinical presentation of precocious puberty of central type. Five cases with hypothalamic hamartoma are reported here, with an emphasis on MR appearance. The most common presentation of hypothalamic hamartoma was a small and well defined mass in the inferior aspect of the hypothalamus, showing isointensity on T1 weighted images and hyperintensity on T2 weighted images compared with the gray matter. The previous reports with MRI description are reviewed and compared with the present results.

Skull base tumors: evaluation with contrast-enhanced MP-RAGE sequence.

The purpose of this study is to assess the value of contrast-enhanced MP-RAGE sequence for evaluation of skull base tumors. A total of 36 patients were prospectively evaluated. MP-RAGE showed relatively higher CNRs than other sequences, and there was a significant difference of CNR between the MP-RAGE and contrast T1-weighted SE images when fat tissue was chosen as the background. MP-RAGE was significantly superior to other sequences in the diagnosis of the extent of tumors. Contrast-enhanced MP-RAGE sequence is useful in evaluation of skull base tumors because of its higher contrast, higher spatial resolution, multiplanar capability, and suppression of the fat signal.

Rectangular field of view for dynamic MR imaging of sellar and parasellar regions.

The effectiveness and quality of a rectangular field of view (R-FOV) were compared with those of a square FOV (S-FOV) in dynamic MR study of sellar regions. Cranial nerves in the cavernous sinus were identified more clearly with R-FOV. The image quality grading of R-FOV was significantly superior to that of S-FOV.

Intraarterial catheter thrombolytic therapy for acute peripheral arterial occlusions.

Intraarterial thrombolytic therapy was performed in 36 patients with acute arterial occlusions of the extremities. Intraarterial thrombolytic therapy was effective in 19 of 24 patients (79.2%) with embolic occlusions. However, the results were poor in patients who had multiple arterial occlusions including those at sites other than the extremities. Only four of 12 patients (33.3%) with thrombotic occlusions had good initial technical results. Six patients died shortly after the thrombolytic procedure, and seven patients underwent amputation. The long-term patency rate of 21 patients who were treated successfully was 92.7% after one year and 74.6% after five years. Intraarterial catheter thrombolytic therapy was effective for embolic occlusion even when more than six hours had elapsed from the onset of symptoms. The indications for thrombotic occlusions may be limited, since associated marked atherosclerotic change was often present.

The trend in airborne asbestos concentrations at plants manufacturing asbestos-containing products in Japan.

In Japan, chrysotile is still permitted to use under the Ordinance on Prevention of Hazards due to Specified Chemical Substances. In recent years many countries have introduced a policy of prohibiting the use of asbestos, based on clinical and epidemiological studies. In light of this, it is important to evaluate the airborne asbestos concentrations in workplaces and also estimate the number of related disease cases in order to discuss the ban of asbestos use. The survey covered 528 workplaces in 145 plants and included 2795 asbestos handling workers from 1985 to 1998. These plants were belonging to the Japan Asbestos Association (JAA) as member companies. In Japan, nearly all of the asbestos using manufacturing companies are members of JAA. In our study, all of the workplaces were divided under each separate manufacturing process and classified into 3 categories of Control Classes. Of the 454/528 (86.0%) workplaces classified as Control Class 1 are improved to 376/378 (99.5%). Though in the cases of small enterprises, other factors such as a shift in product lines, and the economic recession, as well as efforts, contributed to improvements in working conditions. JAA recommended self-administered concentrations of 1.0 f/ml (compatible to <0.3 f/ml in personal exposure level) in 1991 to promote further improvements of the work environment. From this point of view, exposure limits can almost be technically achieved in Japan, and it is expected that asbestos related disease could be expected to decrease in 20 to 30 years later. This survey will become basic material for verifications whether we could control asbestos related diseases enough in such well-controlled work environment.

The effect of solar irradiation on the fading of nylon and polyester fabrics dyed with selected disperse dyestuffs on radiant energy basis.

Solar total, UVA and UVB irradiances were measured separately using three kinds of wavelength band detectors in Tokyo, Japan in November 1999. Characteristics of diurnal variations were examined: Total irradiance reached a maximum value of about 600 W m(-2) at around noon. The variation pattern of UVA irradiance was observed to be similar to the total irradiance. The energy level was about 4.65% of total irradiance. Diurnal variation of UVB was in the form of a steeper bell curve due to the absorption in the air mass. UVB energy to solar total irradiance was about 0.07%. Photodegradation characteristics of two disperse dyestuffs were investigated on the basis of solar radiant energy. A UVA fluorescent lamp was applied to examine the fading characteristics to find the wavelength dependency. As a result, nylon dyeings were less lightfast by a factor of about 6 and 13 for C I Disperse Blue 27 and C I Disperse Blue 165, respectively, compared with polyester on the radiant energy basis. Visible light, as well as UVA, radiation contribute to fading of C I Disperse Blue 165 whereas UVA mostly cause the fading of C I Disperse Blue 27.