A case of anomalous origin of the pulmonary arteries: right pulmonary artery from the descending aorta and the left pulmonary artery from the ascending aorta

A 3-month-old girl classified as having persistent truncus arteriosus underwent surgical correction of the anomalous origin of the pulmonary arteries; the right pulmonary artery from the descending aorta and the left pulmonary artery from the ascending aorta. The patient died on the fourth postoperative day. The definite diagnosis and choice of surgical strategies should be further examined.

A simple distraction device for finger lengthening

A simple, light distraction device was developed for digital lengthening. Materials for this device are one piece of 1.5-mm K-wire, two five-hole miniplates, one one-hole miniplate, two bolts and nuts, and a nonabsorbable suture or surgical wire. These components are easily obtainable, and the device can be assembled easily for each patient during surgery. The principle of distraction using this device is unique: A distal bone segment is pulled straight forward by a suture or surgical wire. This minimizes scar formation on the finger. Finger elongation using commercially available distraction devices needs two transfixations of K-wires, two each for the proximal and distal bone segments, which create scars where the K-wires move. The authors report a clinical application in which their distraction device was used.

Dephosphorylation of specific proteins during induction of senescence in immortal human fibroblasts expressing thermolabile SV40 T antigen

Particular protein kinase inhibitors block a senescence-like phenomenon in SVts8 cells induced by a shift up in temperature. We characterized cellular proteins with affinity chromatography using one such inhibitor as a ligand. Two proteins of 56 and 100 kDa were found to be dephosphorylated specifically, probably due to induction of a protein phosphatase activity(s).

Reverse U-shaped split temporalis musculofascial flap in cranial base reconstruction

To extend the versatility and range of the temporalis muscle, a new type of temporalis musculofascial flap was developed. This was achieved by dividing the muscle into two portions--anterior and posterior-while maintaining vascular communication between the deep and the middle temporal arteries. This flap is reverse U-shaped with one of the arms of the "U" corresponding to a pedicle, which supplies the blood, and the other corresponding to the recipient region. The bottom of the U corresponds to continuity between the anterior and posterior portions of the muscle, which contains the vascular communication. In two patients with meningioma, the flap was applied to occupy the extradural dead space combined with a pericranial flap to prevent leakage of cerebral spinal fluid to the dural defect. The reverse U-shaped split temporalis musculofascial flap has some advantages for intracranial reconstruction: sufficient rotational arc, adequate thickness, and rich vascularity. A reverse U-shaped split temporalis musculofascial flap is useful and of benefit, especially for reconstruction at the region of the anterior midline skull base.

Coronary artery bypass grafting in a case with severe aortic atheromatosis associated with abdominal aortic aneurysm

A 69-year-old man with coronary artery disease associated with abdominal aortic aneurysm underwent a one-stage operation utilizing a low-flow cardiopulmonary bypass. Ordinary cardiopulmonary bypass was abandoned as a result of severe atheromatous finding in the entire aorta. However, coronary artery bypass grafting without cardiopulmonary bypass was hazardous as a result of heart enlargement and deteriorating function. Therefore, the abdominal aortic aneurysm was first replaced with a bifurcated graft. Coronary artery bypass grafting with two arterial grafts was then performed successfully on the beating heart with the support of a low-flow cardiopulmonary bypass connected to the bifurcated graft.

[Valve replacement in children]

Between May 1979 and September 1998, 202 children underwent surgical treatment for valvular heart disease. Of these 23, who ranged in age from 25 days to 15 years, underwent valve replacement, including 1 reoperation. The valve replacement consisted of the aortic valve in 5 patients, the mitral valve in 3, the tricuspid valves in 9, including 5 systemic atrioventricular valves for atrioventricular discordance, the pulmonary valve in 6, 5 bioprostheses and 18 mechanical prostheses. There were 4 operative deaths, 1 hospital death and 3 late deaths. At the 10-years follow-up, the actual survival rate was 67.8%, the event free rate was 76.1% and the freedom from reoperation rate was 86.2%. Valve re-replacement was performed in only 1 patient due to a thrombosed tricuspid valve. These results suggest that there is a small risk of major complications and reoperation in children who undergo valve replacement, whether a bioprosthetic valve or a mechanical valve. The long-term results of younger patients should be followed more closely according to their growth.

The introduction of dominant-negative p53 mutants suppresses temperature shift-induced senescence in immortal human fibroblasts expressing a thermolabile SV40 large T antigen

Immortal human fibroblasts, SVts8 cells, which express a heat-labile SV40 large T antigen, induces a senescence-like phenomenon in response to upward shift in temperature. Cells with arrested division show strong induction of senescence-associated beta-galactosidase. We examined how p53 and pRB are involved in this phenomenon since they are major targets of the T antigen. Transfection of cells with plasmids encoding the wild-type T antigen or human papilloma virus type 16 E6/E7 proteins completely abolished the arrest in cell division, a plasmid encoding the E6 protein suppressed it markedly, while a plasmid encoding E7 had no effect. Plasmids encoding dominant-negative p53 mutants also suppressed the arrest in cell division to various degrees. Upon temperature shift, p21 mRNA was upregulated 10-fold in SVts8 cells, but only slightly in clones expressing the wild-type T antigen or dominant-negative p53 mutants. These data demonstrate that p53 plays a major role in this senescence-like phenomenon.

High origin of the right coronary artery with congenital heart disease

We encountered a case of anomalous high origin of the right coronary artery associated with ventricular septal defect and patent ductus arteriosus. The right coronary artery originated from the distal part of the ascending aorta resulting in unsuccessful induction of cardiac arrest by cardioplegia. We describe this rare case with anomalous origin of the right coronary artery.

Early and mid-term outcomes of cardiac and thoracic aortic surgery in over-75-year-olds with postoperative quality of life assessment

The early and mid-term outcomes of cardiac and thoracic aortic surgery were reviewed in seventy-two consecutive patients aged 75 years and older, together with assessment of postoperative quality of life. Twenty-six patients had ischemic heart disease, twenty had valvular heart disease, one had congenital heart disease, and twenty-five had thoracic aortic aneurysm. Twenty-five (34.7%) required an emergency operation. There were 6 early deaths (8.3%) and 11 late deaths (17.2%), of which the emergency cases had higher mortality of 5 early deaths (20.0%) and 3 late deaths (15.0%). In particular, most cases with a ruptured thoracic aortic aneurysm died eventually from various complications including neurological dysfunction. The others with a non-ruptured aneurysm also had atherosclerotic aortic or arterial lesions which caused a lethal cerebrovascular accident or ischemic heart disease. The quality of life of 51 of 53 survivors was assessed using the Rosser and Watts index being based on disability and distress scores. The response was satisfactory--the disability score was 2.6 +/- 1.9 and the distress score was 1.4 +/- 0.4. The patients with a thoracic aortic aneurysm had worse quality of life scores than those of the ischemic heart disease or valvular heart disease patient-groups because of various perioperative complications. Our experiences demonstrate that the results including the postoperative quality of life following cardiac and aortic surgery in the elderly is satisfactory except for emergency cases. The results would prompt us to operate, if possible, electively in their stable conditions, even on elderly over-75-year-olds.

Single-stage surgery for distal aortic arch aneurysm and infrarenal abdominal aortic aneurysm through anterolateral approach

A 58-year-old man with a distal aortic arch aneurysm (DAA) associated with an infrarenal abdominal aortic aneurysm (AAA) successfully underwent a single-stage replacement of the aneurysms. A left anterolateral thoracotomy was used for replacement of the DAA, which was performed using profound hypothermic circulatory arrest and continuous retrograde cerebral perfusion. An extraperitoneal approach in conjunction with a lateral abdominal incision was employed for replacement of the AAA. The combination of an anterolateral thoracotomy and a lateral abdominal incision is useful in combined surgery for DAA and AAA.

Enzymatic synthesis of fructose 1,6-Diphosphate with ATP regeneration in a batch reactor and a semibatch reactor using purified enzymes of Bacillus stearothermophilus

The enzymatic synthesis of fructose 1,6-diphosphate (FDP), an important glycolytic intermediate whose applications in the field of medicine have generated a great deal of interest, was performed in a batch reactor and a semibatch reactor. Using the batch reactor, FDP was first synthesized from glucose by three enzymatic reactions and the ATP consumed was regenerated simultaneously using conjugated enzymes, all of which were purified from crude cell extract of thermophilic Bacillus stearothermophilus. The results of the experiments performed using several enzyme concentrations suggest the existence of an optimum concentration for each enzyme at which the maximum FDP yield can be attained. Since the thermal decomposition of acetyl phosphate reduced the yield of FDP in the batch reactor, the use of a semibatch reactor in which acetyl phosphate was fed continuously was examined. The yield of FDP was improved but the time required to complete the reaction was longer, resulting in a lower productivity of FDP. The yields observed in the two reactors using various enzyme and substrate concentrations were in good agreement with the theoretical predictions calculated based on differential equations derived for the system using the rate equations and the kinetic parameters determined previously. This means that these equations can be used for the analysis of the experimental results as well as for determining the optimum experimental conditions.

Theoretical investigation of fructose 1,6-diphosphate production and simultaneous ATP regeneration by conjugated enzymes in an ultrafiltration hollow-fiber reactor

The performance of an ultrafiltration hollow-fiber reactor, in which enzymatic synthesis of fructose 1,6-diphosphate (FDP) from glucose and enzymatic ATP regeneration are performed simultaneously, was analyzed theoretically. The reaction system consists of three-step synthetic reactions catalyzed by glucokinase (GK), phosphoglucose isomerase and phosphofructokinase, and the ATP regeneration reaction catalyzed by acetate kinase. Based on a simple analytical model developed previously in which the liquid flowing in a tube was assumed to be plug flow and the radial concentration gradients in the tubes and shell side space were both neglected, a computer program was developed to calculate the concentration profiles of all the components along the flow direction in the tubes and shell side space of the reactor. From the FDP concentrations at the reactor outlet calculated under various operational conditions, reactor performances such as the FDP yield and the ATP recycle number were determined. The calculation showed the interesting phenomenon that under some conditions the FDP yield was higher when GK concentration was lower.

Peptide synthesis catalyzed by organic solvent-stable protease from Pseudomonas aeruginosa PST-01 in monophasic aqueous-organic solvent systems

The equilibrium yields of the peptide Cbz-Arg-Leu-NH2 synthesized from Cbz-Arg and Leu-NH2 using the PST-01 protease in the presence of organic solvents were investigated under various conditions. The equilibrium yields depended little on the concentration of the carboxyl component, but significantly on the concentration of the nucleophile. The optimum temperature and pH for a high equilibrium yield were 30 degrees C and greater than 5.0, respectively. Under optimum conditions the equilibrium yields were 71.6% and 87.7% in the presence of 50% (v/v) DMF and 60% (v/v) DMSO, respectively. Furthermore, the PST-01 protease also catalyzed the syntheses of the dipeptides Cbz-Lys-Leu-NH2, Cbz-Ala-Leu-NH2, Cbz-Ala-Phe-NH2, Cbz-Arg-Leu-NH2, and Cbz-Lys-Phe-NH2 with equilibrium yields of more than 60% in the presence of 50% (v/v) DMF and 50 mM sodium phosphate buffer (pH 7.0).

Enzymatic production of fructose 1,6-diphosphate using crude cell extract of Bacillus stearothermophilus

The enzymatic production of fructose 1,6-diphosphate (FDP) from glucose was performed in a batch reactor and a semibatch reactor using the crude cell extract of Bacillus stearothermophilus which contains all four enzymes required for the synthesis. The experimental results of the yield and the time courses of FDP production obtained using various enzyme concentrations were in good agreement with the theoretical predictions calculated based on the differential equations including the rate equations of the four enzymes, which were determined using the purified enzymes of B. stearothermophilus.

Purification and characterization of organic solvent-stable protease from organic solvent-tolerant Pseudomonas aeruginosa PST-01

An organic solvent-stable protease (PST-01 protease) in a culture broth of organic solvent-tolerant Pseudomonas aeruginosa PST-01 was purified by successive hydrophobic interaction chromatography using Butyl-Toyopearl gels. The purified enzyme was homogeneous as determined by SDS-polyacrylamide gel electrophoresis. PST-01 protease had a molecular mass of 38 kDa. The optimum temperature and pH for casein hydrolysis were 55 degrees C and 8.5, respectively. PST-01 protease was stable at pH 8-12 and below 50 degrees C and was determined to be a metalloprotease which was inhibited by EDTA, 1,10-phenanthroline, and phosphoramidon. PST-01 protease inhibited by EDTA was reactivated completely by the addition of zinc or cobalt ions. The stability of PST-01 protease in solutions containing water-soluble organic solvents or alcohols was higher than that in the absence of organic solvent. Furthermore, in general, PST-01 protease was more stable than commercially available proteases, namely, subtilisin Carlsberg, thermolysin, and alpha-chymotrypsin, in the presence of water-soluble organic solvents or alcohols.

Purification and characterization of lipase from Rhizopus chinensis cells

Lipase from Rhizopus chinensis cells was purified and characterized. The molecular mass of purified lipase was 28.4 kDa and the optimal temperature and pH for its activity were 37 degrees C and 5.5, respectively. Purified lipase exhibited high hydrolytic activity against fatty acid methyl esters such as methyl caprylate, methyl laurate, and methyl palmitate. Freeze-dried lipase catalyzed the transesterification between olive oil and methyl laurate in n-hexane.

DNA topoisomerase inhibitors induce reversible senescence in normal human fibroblasts

Inhibitors of DNA topoisomerases I and II induced arrest in cell division in normal human fibroblasts depending on cell divisions. Arrested cells showed morphology similar to those of normally senesced cells and strongly induced senescence-associated beta-galactosidase. In these cells, p16ink4a was upregulated, whereas p21waf1 or p53 was not altered. Upon removal of the inhibitors, the cells resumed growth but their cumulative population doublings were reduced dose dependently. Accelerated telomere shortening was not observed in the arrested cells. These results suggest that DNA topoisomerase inhibitors are efficient and reversible inducers of premature senescence in normal human cells.

[Clinical features in patients with delayed endolymphatic hydrops]

We report clinical features in patients with delayed endolymphatic hydrops (DEH) with juvenile unilateral deafness. Among 23 patients with DEH, 15 cases were diagnosed as ipsilateral DEH and 8 cases as contralateral DEH. The distribution of onset age showed two peaks at ages of < 30 years and > 40 years. In 80% of the ipsilateral DEH cases, the onset of episodic vertigo was at younger ages. On the other hand, in 75% of the contralateral DEH cases, the onset of fluctuation hearing loss of the contralateral ear was at older ages. Ispilateral DEH and Meniere's disease may show different pathophysiologies. The incidence of dominant negative summating potential in the better-hearing ear was 20% in the ispilateral DEH cases and 60% in the contralateral DEH cases. It is suggested that endolymphatic hydrops is in the better-hearing ear of contralateral DEH.

Monitoring of regional cerebral oxygenation by near-infrared spectroscopy during continuous retrograde cerebral perfusion for aortic arch surgery

OBJECTIVE

To assess the value of monitoring of regional cerebral oxygen saturation (rSO2) during aortic arch surgery using continuous retrograde cerebral perfusion (CRCP) in conjunction with profound hypothermic circulatory arrest (HCA).

METHODS

The rSO2 of 12 consecutive patients was monitored non-invasively using near-infrared spectroscopy (NIRS) and the data were analyzed statistically.

RESULTS

The mean duration of HCA with CRCP was 62-/+14.1 min. The mean CRCP flow rate was 226+/-163 ml/min. Surgical outcomes were favorable with only a single hospital death (8.3%). However, the rSO2 decreased gradually in all patients during HCA, even combined with CRCP, and fell to 46+/-8.7% on average. It did not change so greatly before HCA and returned finally to its initial level at the end of re-warming. Only one patient developed a permanent neurologic deficit; this patient showed the greatest decrease of rSO2 from 56% to 29% after the longest HCA of 88 min. Two parameters, End-rSO2 (the ratio of post- to pre-HCA rSO2) and delta-rSO2 (the rate of decrease from preto post-HCA rSO2) were obtained since the initial values of rSO2 before surgery differed. There were linear correlations between the CRCP flow rate and each of these two parameters. A multiple regression analysis also revealed a linear equation relating the parameters, which allowed prediction of the safe duration of HCA in different conditions of CRCP and a more favorable adjustment of the CRCP condition in each patient.

CONCLUSIONS

The study suggests that the combination of HCA and CRCP has a limit of safe duration in spite of its potential usefulness for brain protection, and that rSO2 monitored by NIRS is useful in testing for adequate brain protection. It is hoped that monitoring of rSO2 can facilitate prediction of the safe duration of HCA with CRCP and a more favorable adjustment of CRCP.

Aortic valve replacement in a patient with previous coronary artery bypass grafting

Gaining a sufficient exposure for aortic valve surgery after previous coronary artery bypass grafting (CABG) has been a problem due to the patent saphenous vein grafts. Although a patient had had CABG twice we performed aortic valve replacement (AVR) with almost the usual exposure. We attached the proximal anastomosis in a more distal position of the ascending aorta than usual, at the first CABG, as he was diagnosed to have mild aortic valve stenosis prior to surgery. We consider this method allows easier AVR after previous CABG when the patient is diagnosed with mild aortic valve stenosis before CABG.

Diffuse pulmonary lesions in early phase Takayasu arteritis predominantly involving pulmonary artery

We report a case of early phase Takayasu arteritis that predominantly involved the pulmonary arteries and had, along with expected radiographic findings, the unusual pattern of diffuse pulmonary parenchymal lesions on CT. We suggest that this finding may be an additional feature in early phase Takayasu arteritis and need not require investigation for an additional diagnosis.

Clustering of human chromosome fragments on the mouse genome by chromosome-mediated gene transfer

Pieces of metaphase chromosomes prepared from mouse cells containing neo-tagged human chromosome 7 were transferred to mouse cells with calcium phosphate to isolate G418-resistant clones. FISH analysis revealed that the majority of them contained human DNA at a single site on their genome. These transformants contained STS markers mapped to various regions of chromosome 7. It is thus suggested that pieces of human chromosomes tend to assemble and integrate on the mouse genome.

Release of telomeric DNA from chromosomes in immortal human cells lacking telomerase activity

Some immortal human cell lines lack telomerase activity. These cell lines were found to contain small dispersed DNA hybridizing to TTAGGG repeats. Such DNA was located in their cytoplasm and nuclei. Normal human fibroblasts or telomerase-positive cell lines did not contain such DNA. Upon cloning and sequencing, it was shown to consist of TTAGGG repeats. When electrophoresed on neutral and alkaline agarose gels, it behaved as double-stranded and linear DNA. These results suggest that telomeric DNA is released from chromosomes in association with maintenance of telomeres in telomerase-negative cell lines.

Effect of additives on refolding of a denatured protein

Denatured lysozyme was refolded by a dilution method. The refolding yield depended greatly on the lysozyme concentration in the refolding mixture. When the concentration of denatured lysozyme was 0.02 g/L, the refolding yield was as high as 60%. However, when the concentration of denatured lysozyme was 0.2 g/L, the refolding yield was as low as 10% due to the formation of aggregates. To prevent the formation of aggregates and to increase the refolding yield at a low cost, inexpensive additives were screened. The addition of acetone, acetoamide, or urea derivatives was very effective for improving the refolding yield. To clarify why the addition of acetoamide in the refolding mixture improved the refolding yield at the high lysozyme concentration, the time courses of the concentration and the average diameter of the aggregates in the refolding mixture were monitored by the dynamic light scattering method. The experimental results showed that acetoamide played a role in preventing the formation and growth of aggregates and secondary aggregation between the lysozyme aggregates.

Coronary artery bypass grafting for an adult with coronary disease due to Kawasaki disease

Surgical treatment for patients over the age of forty with coronary aneurysms associated with Kawasaki disease is rare. We report on a 47-year-old man who underwent coronary artery bypass grafting using the left internal thoracic arteries (ITA) and right gastroepiploic (GEA). The postoperative course was uneventful. One month later, the normal stress thallium-201 myocardial perfusion imaging was normal and coronary angiography showed good patency for the ITA, GEA, and saphenous vein grafts. He had some coronary risk factors including smoking, hypertension and hyperlipidemia. Histological examination of a sample shows that the coronary artery sequelae of Kawasaki disease have already become part of increasing burden of adult ischemic heart disease.

Induction of lens differentiation by activation of a bZIP transcription factor, L-Maf

After the vertebrate lens is induced from head ectoderm, lens-specific genes are expressed. Transcriptional regulation of the lens-specific alphaA-crystallin gene is controlled by an enhancer element, alphaCE2. A gene encoding an alphaCE2-binding protein, L-maf(lens-specific maf), was isolated. L-maf expression is initiated in the lens placode and is restricted to lens cells. The gene product L-Maf regulates the expression of multiple genes expressed in the lens, and ectopic expression of this transcription factor converts chick embryonic ectodermal cells and cultured cells into lens fibers. Thus, vertebrate lens induction and differentiation can be triggered by the activation of L-Maf.

Two-stage repair for aortic regurgitation with interrupted aortic arch

We performed two-stage repair for a rare adult case of interrupted aortic arch with aortic regurgitation and sinus of Valsalva aneurysm. A lateroisthmic bypass was established with minimal thoracotomy and partial clamping of the descending aorta to preserve collateral circulation. This was followed by aortic root reconstruction with a prosthetic graft and valve for aortic regurgitation with sinus of Valsalva aneurysm. This less invasive two-stage repair for such a rare pathology may facilitate smooth recovery of the patient.

A case of bowel necrosis due to acute mesenteric ischemia following pulsatile cardiopulmonary bypass

We report a case of fatal bowel necrosis possibly caused by pulsatile cardiopulmonary bypass (CPB). An 80-year-old female underwent emergency coronary artery bypass grafting (CABG) for unstable angina. Pulsatile CPB was applied because of stenosis of bilateral carotid and renal arteries. On the third postoperative day, total bowel necrosis due to acute mesenteric ischemia was revealed at emergency laparotomy before her death. Pulsatile CPB may increase the risk of distal embolism of dislodged plaque in cases with severe aortic atheromatosis.

Spontaneous retrograde dissection of the entire thoracic aorta originating in the abdominal aorta. Case report and review of the literature

Spontaneous retrograde thoracic extension of the abdominal aortic dissection is extremely rare and difficult to manage. Only five cases have been previously reported in the English literature (dissection reaching the ascending aorta in four, dissection limited in the descending thoracic aorta in one), and all the cases of dissection which reached the ascending aorta were lethal. We herein report one case of a 37-year-old man who was operated on for spontaneous retrograde dissection of the entire thoracic aorta originating in the suprarenal abdominal aorta. Preoperative aortogram revealed the site of the intimal tear just above the celiac artery. He urgently underwent graft replacement of the descending thoracic aorta and the abdominal aorta with reimplantation of the thoracoabdominal visceral arteries. Although the patient had to undergo the second operation for the dissection of the remaining thoracic aorta four months postoperatively, he has been doing well 18 months after the second operation.

Mitral valve repair in a patient with severe porcelain aorta

We repaired the mitral valve in a patient with severe porcelain aorta. Significant mitral regurgitation developed in a 66-year-old woman with heavy calcification throughout the whole aorta. At operation, cardiopulmonary bypass was properly established by combined axillary and femoral arterial cannulations for sufficient systemic flow. Likewise, the combination of a superior mitral approach and profound hypothermic fibrillatory arrest in conjunction with low-flow cardiopulmonary bypass allowed us to repair the mitral valve successfully.

Constrictive pericarditis caused by an old hematoma

A 46-year-old woman was admitted for surgery after diagnosis of a constrictive pericarditis. She had suffered from acute pericarditis and undergone pericardiocentesis to relieve pericardial effusion several times 10 years previously. Cardiac catheterization showed elevated mean right-atrial and pulmonary wedge pressures. Chest CT revealed only a calcified mass in the retrosternal space. At surgery, there was no severe adhesion between the pericardium and the epicardium, and the pericardium was thin and almost normal except over the right artio-ventricular groove, where a hard mass with an atheromatous content adhered to the epicardium. After resection of the mass, central venous pressure and pulmonary wedge pressure decreased. The mass was found to be an old hematoma by pathological examination. The patient was subsequently discharged from hospital in good condition.

Multiple hepatoblastomas associated with trisomy 18 in a 3-year-old girl

A very rare case of full trisomy 18 associated with multiple hepatoblastomas is reported. The patient also had ventricular septal defect and patent ductus arteriosus, which were repaired at 6 months of age. After the cardiac surgery, she was noted to have an abdominal mass and an elevated serum alpha-fetoprotein level. A partial hepatic lobectomy was performed at 7 months of age, and the resected tumor was diagnosed as a fetal-type hepatoblastoma. At 2 years and 4 months of age, a chest radiography disclosed an elevated left diaphragm, and abdominal ultrasonography demonstrated a tumor in the left hepatic lobe. The resected tumor was also diagnosed as a fetal-type hepatoblastoma. Chromosomal analysis demonstrated that the karyotypes of peripheral blood and hepatic tumor cell obtained on two occasions were both 47,XX, +18. She has no evidence of recurrence at 3 years of age without specific therapy.

Remarkable growth of the internal mammary artery used for systemic-to-pulmonary artery shunt in a patient with cyanotic heart disease

The left internal mammary artery-to-the left pulmonary artery shunt was created in a 16-year-old boy with single ventricle, severe pulmonary stenosis palliated by Glenn shunt at the age of two. Four years follow-up angiogram demonstrated a significant increase of the diameter of the left internal mammary artery from 4 to 7 mm. The internal mammary artery is a good alternative conduit for a systemic-to-pulmonary artery shunt for a cyanotic heart disease because of its growth potential.

[Emergent coronary artery bypass grafting in a patient with mirror-image dextrocardia]

A 49 year-old-man with known situs inversus totalis was admitted to our hospital with a history of angina pectoris of 4 months duration. Coronary arteriography revealed that the left main trunk had a 90% stenosis. After the arteriography, the patient's hemodynamics was deteriorated, and he required a support of intraaortic balloon pumping. He underwent emergent coronary artery bypass grafting with saphenous veins the following day, and recovered uneventfully. Technical problems in this patient from a surgical viewpoint were discussed. As far as we know, this is the first case of coronary bypass grafting on a patient with mirror-image dextrocardia and a stenosis of the left main trunk.

An assay method for nitric oxide-related compounds in whole blood

Recent evidence suggests that nitric oxide (NO) generated in vivo will be converted into the forms of nitrite/nitrate, nitrosyl hemoproteins, nitrosyl metal complexes, and S-nitroso-compounds in the circulation. Nitrosothiols have also been reported to be relatively stable metabolites with micromolar levels in plasma. We hypothesized, therefore, that the determinations of all the NO-related compounds in blood would be of diagnostic significance. The assay method described here consists of the thermolysis of all the NO-related compounds in whole blood and the detection of resulting nitrate by fluorometry or chemiluminescence after an enzymatic reduction. S-Nitroso-albumin and nitrosyl hemoglobin can be easily thermolysed to nitrate, and relatively stable S-nitroso-glutathione is also degraded to nitrate in the presence of blood constituents with high molecular mass (above 30 kDa). Concentrations of NO-related compounds in blood from healthy human as well as control or lipopolysaccharide-stimulated rats were determined. We found that membrane-bound NO which showed the augmented levels under the pathophysiological states could also be detected. Together with electron spin resonance spectra, our data indicate that the fraction of NO diffused and metabolized within red cells and the other NO-metabolites in plasma such as nitrite/nitrate and S-nitroso-compounds, both of which can reflect NO-production in vivo, would be recovered and detected quantitatively by this method.

[Clinical features and utricular dysfunction in patients with benign paroxysmal positional vertigo]

We report the clinical features in patients with benign paroxysmal positional vertigo (BPPV), who met the following criteria; (1) a history of brief episodes of positional vertigo, and (2) a characteristic torsional paroxysmal positional nystagmus that was observed visually. The mean age of onset was 55 years. There was no sex predominance. In most patients, positional vertigo disappeared within 2 months. We then used the eccentric rotatory test to examine the patients otolithic function. In the eccentric rotatory test, a patient is rotated around an axis located behind his head (eccentric rotation, ECR). We have demonstrated that the enhancement of vestibulo-ocular reflex (VOR) gain in ECR can be used as an index of the utricular function. Enhancement of VOR gain was observed in ECR to the lower ear in positional vertigo, but not to the uppermost ear. The findings suggest an imbalance in utricular function in patients with BPPV. Otoconia dislodged from the deranged utricle may be a source of canalolithiasis/cupulolithiasis.

Possible application of transmitted laser light for the assessment of human pulpal vitality

The purpose of this study was to determine whether use of transmitted laser light would enable a better assessment of human pulpal vitality than back-scattered light does (LDF: laser Doppler flowmetry). The experiments were carried out on ten upper central incisors in six subjects aged 23-28 years; five of the teeth were vital with no restoration, and five were non-vital. For use with transmitted laser light, the fibers within the probe of a conventional LDF apparatus were used, one for transmitting light onto the buccal surface, the other for receiving it at the palatal surface of the same tooth. For LDF, the probe was fixed at the buccal surface. Blood flow was measured at three different locations on each experimental tooth: the incisal third, the center and the cervical third of the tooth crown. In non-vital teeth, 1) output signals with transmitted laser light all registered zero, and no oscillation could be seen in recordings from any location on the tooth, but 2) LDF signals were above zero, there were regular oscillations related to heart rate, and passive increases in blood flow (corresponding to blood pressure increases) were recorded from both the center and the cervical third of the tooth, indicating that LDF registered blood flow of non-pulpal origin. In vital teeth, LDF signals were significantly higher than in non-vital teeth at each location on the tooth. At the central site on vital teeth, the output signals for transmitted laser light were about twice those seen with LDF, and passive blood flow changes corresponding to blood pressure increases were more clearly observed. These results indicated that transmitted laser light would be useful for the assessment of tooth pulp vitality both because the blood flow signals did not include flow of non-pulpal origin, and because its output signals and response to blood flow changes were clear and could easily be monitored.

Surgical management of aortic regurgitation associated with ventricular septal defect

Surgical treatment for congenital aortic regurgitation (AR) with ventricular septal defect (VSD) in pediatric patients carried out between 1979 and 1994 was reviewed. Aortic commissural valvuloplasty (AVP) was performed on prolapsed cusps in 34 patients (mean age 6.3 +/- 3.3 years (range: 2 to 24 years) with AR and VSD. The preoperative grade of AR was 2.6 +/- 0.8 measured angiographically by Sellers' classification. Patients had greater than moderate AR in conjunction with subpulmonary (n = 16), perimembranous (n = 15) or mixed type VSD (n = 3). In total, 25 right coronary cusps (RCC), five non-coronary cusps (NCC) and one left coronary cusp were repaired. In two cases, both RCC and NCC were plicated. One case had bicuspid valve and both cusps were repaired. There were no operative or late deaths. Moreover, the AR grade of the 25 cases has been below mild during a mean of 11.3 years follow up, though seven cases (22%) have developed above moderate AR. The two cases with persistent AR required redo AVP, with one having aortic valve replacement eventually after redo surgery. The operative findings showed cusp perforation on the repair site, or cusp elongation. However, the overall event-free rate analyzed by the Kaplan-Meier method was sufficiently favorable, with 96.6 +/- 3.4% for 5 years and 92.8 +/- 4.9% for 10 years. We conclude that aortic valvuloplasty for aortic regurgitation and VSD in pediatric patients is beneficial, with low mortality and reoperation rates.

Mid-term results of mitral valve replacement combined with chordae tendineae replacement in patients with mitral stenosis

BACKGROUND AND AIMS OF THE STUDY

Although many studies have found that preservation of the continuity between the mitral annulus and the papillary muscles during mitral valve replacement improves postoperative left ventricular performance in patients with mitral regurgitation, much less research has been done in this respect in patients with mitral stenosis. We reviewed our experience with mitral valve replacement combined with chordae tendineae replacement in 29 patients with mitral disease, 26 of whom had mitral stenosis.

METHODS

During mitral valve replacement, continuity between the papillary muscle and annulus was restored with expanded polytetrafluoroethylene (ePTFE) mattress sutures, which were threaded into the compact portion of each papillary muscle and placed at the 2, 4, 8 and 10 o'clock positions in the mitral annulus. Postoperatively, the patients were followed by echocardiographic assessment and exercise (stress) radionuclide angiography testing. The stress test results were compared with those in patients who had undergone traditional mitral valve replacement, and also those in normal people.

RESULTS

There were no hospital deaths, complications, or cardiac deaths or events during a median follow up of two-and-a-half years. Echocardiography showed no postoperative cardiac dilatation. The stress tests found no significant differences between the ejection fraction in mitral stenosis patients who underwent conventional mitral valve replacement and in those who had valve replacement combined with ePTFE chordae tendineae replacement.

CONCLUSIONS

A direct advantage of chordae-preserving mitral valve replacement over conventional replacement with respect to postoperative global left ventricular performance in patients with mitral valve stenosis has not been demonstrated. However, postoperative regional left ventricular contraction in patients with mitral stenosis has been observed to be better among those who have undergone the chordae-preserving procedure. Additional investigations are needed to elucidate the effects of this procedure in mitral stenosis, but we believe that the technique improves left ventricular performance and may decrease the risk of left ventricular rupture.

Influence of preconditioning on rat heart subjected to prolonged cardioplegic arrest

BACKGROUND

Ischemic preconditioning (IP) can reduce lethal injury to the myocardium induced by prolonged ischemia. However, little is known about the effect of preconditioning on the heart subjected to cardioplegic arrest and hypothermic preservation. We evaluated the effect of IP on myocardial metabolism, mechanical performance, and coronary endothelial function after cardioplegic arrest and prolonged hypothermic preservation.

METHODS

An isovolumic Langendorff perfused rat heart model was used, and hearts were divided into two groups. The first group (IP, n = 14) was preconditioned by 5 minutes of global normothermic (37 degrees C) ischemia followed by 10 minutes of normothermic reperfusion before 6 hours of cold (4 degrees C) preservation, followed by 60 minutes of reperfusion. The second group (control, n = 15) was subjected to 6 hours of cold preservation followed by 60 minutes of reperfusion without preconditioning. Mechanical function was assessed using left ventricular balloon by constructing pressure-volume curves in two ways: at defined left ventricular volumes or at defined left ventricular end-diastolic pressures. Initially, the volume of the balloon was increased incrementally from 0 to 150 microL in 25-microL steps. Measurements were then repeated with loading balloon to achieve left ventricular end-diastolic pressure of 5, 10, 15, or 20 mm Hg. Myocardial function was assessed before ischemia and at 15 or 60 minutes of reperfusion. Metabolic status of the heart was evaluated by measuring the release of purine catabolites during the initial 15 minutes of reperfusion and concentrations of myocardial nucleotides at the end of reperfusion. Endothelium-mediated vasodilatation was evaluated using 10 mumol/L 5-hydroxytryptamine before and after ischemia.

RESULTS

Left ventricular end-diastolic pressure values were significantly lower in the IP group, by 20% to 40%, during the reperfusion phase at each volume of the balloon compared with the control group. The rate-pressure product was more favorable during reperfusion in the IP than in the control group because of a 15% increased heart rate in the IP group. The release of purine catabolites from the heart during the reperfusion phase was reduced (p < 0.01) in the IP group (0.66 +/- 0.04 mumol) relative to the control group (0.92 +/- 0.06 mumol). No difference in the recovery of systolic function, myocardial adenosine triphosphate concentration, or endothelial function was observed between the groups.

CONCLUSIONS

Under conditions of cardioplegic arrest and hypothermic preservation, IP can offer additional protection for the heart by preventing an increase in diastolic stiffness. However, metabolic improvement or better preservation of the systolic or endothelial function was not observed in this model.

[Surgical treatment of infective endocarditis]

From 1981 to 1996, 48 consecutive patients, aged range 1 to 72 years, underwent surgical treatment for infective endocarditis. The infection was in the aortic valve in 10 patients, the mitral valve in 17, the aortic and mitral valves in 7, mixed aortic, mitral and tricuspid valves in one, the tricuspid valve in 9, the pulmonary valve in 3, and the other in 2, thirty-seven patients had native valve endocarditis (NVE) of which 22 cases were in the active stage. Seven cases had active prosthetic valve endocarditis (PVE) and 4 had VSD patch infection. The overall hospital mortality rate was 14.6% (7/48). The hospital mortality rate of NVE was 2.7% (1/37) and that of active NVE was 4.5% (1/22). That of PVE was 71.4% (5/7) and one of 4 cases with VSD patch infection was lost, so the mortality rate of the prosthetic material infection was 54.5% (6/11). Only 1 patient required reoperation for persistent infection. There were 2 late deaths caused by noncardiac disease. Thirty-nine of the total IE patients are now survived. These data demonstrate excellent results in patient with NVE undergoing the surgical treatment at the early phase, and support the premise that patients with active PVE should have also early surgical intervention.

A panel of radiation hybrids defining the 7q31-q32 region of human chromosome 7

Mouse A9 cells containing human chromosome 7 tagged with pSV2neo were irradiated with X-rays and fused to A9 cells to isolate G418-resistant clones. From these clones, we selected radiation hybrids that contained 10-40 Mb of human DNA apparently at a single site of their genome by FISH analysis using human repetitive sequences as a probe. Then we made a panel of hybrids that contained various fragments of the 7q31-q32 region and cover its entire region altogether by PCR with STS markers of human chromosome 7. This panel is useful in chromosome transfer experiments since the dominant selective marker neo gene is attached to human DNA.