Development of a Direct Polycondensation Process for Poly (L-lactic acid)

Poly(L-lactic acid) (PLLA) is quite promising for use as biodegradable and non-petroleum derived plastics. In this study we developed an innovative two-step polycondensation process so as to produce economically PLLA with high molecular weight. The process is composed of both melt polycondensation under the lactide-re ux and solid-phase polycondensation. First we studied a direct polycondensation of L-lactic acid with a small amount of solvent, using a mixture of L-lactic acid as raw material, diphenyl ether as solvent, Tin (II) chloride dihydrate as catalyst, and p-toluene sulfonic acid as a discoloration prevention agent. After the dehydrative oligomerization of L-lactic acid, the polycondensation of the oligocondensates and solid-phase post-polycondensation, PLLA of Mw = 266,000 could be obtained. Then, we carried out direct bulk polycondensation tests from L-lactic acid without any solvent added. After optimization of the reaction conditions, PLLA with Mw = 134,000 was successfully produced by the melt-poly-condensation of L-lactic acid accompanied by solid-phase post-poly-condensation. In both systems, the lactide-re ux was indispensable for promoting dehydration/water removal. The re uent lactide was taken into the polymer-chain by trans-esterification reaction during the melt-poly-condesation. Furthermore, the catalyst was allowed to deactivate and stabilize during the solid-phase polymerization to cause the Mw growth.

Biodegradable Poly(Lactic Acid) with High Molecular Weight

Biodegradable plastics have been quickly accepted as one of the key solutions for today's waste plastics problems in Japan. Particularly, poly(lactic acid) is looked forward to as the most promising biodegradable plastics because of its high quality in optical and physical properties as well as chemical recyclability and compostability. Furthermore, lactic acid as a raw material of this polymer can be produced from agricultural starch wastes. However, one of the greatest issues in biodegradable plastics including poly(lactic acid) and lactic acid-based copolymers lays in their extremely high price when compared to typical commodity plastics on the market. Regarding poly(lactic acid), a polymer with high molecular weight of more than Mw = 100 000 is conventionally obtained only by a ring-opening polymerization process from lactide, i.e., dimer of lactic acid, which is very expensive.

To aim at developing practical and economical technologies for effectively producing poly(L-lactic acid) as a representative of lactic acid-based polymer, we have been carrying out continuous melt-polymerization experiments using the combination of a batch type stirred reactor and an intermeshed twin screw extruder in this study. As a result, we have successfully obtained poly(L-lactic acid) with higher molecular weight of up to Mw = 150 000 from lactic acid by a continuous melt-polycondensation process.

[Efficacy of docetaxel (TXT) combined with cisplatin (CDDP) in non-small cell lung cancer]

A multicenter cooperative study of docetaxel (60 mg/m2) combined with cisplatin (60 mg/m2) was performed in stage III and IV patients with inoperable non-small cell lung cancer from March 1998 to September 1999. Of 37 patients enrolled, 36 patients were eligible. One patient obtained a complete response (CR) and nine patients had a partial response (PR). The overall response rate in 36 patients was 28.6%. The median survival time was 360 days. The response rates of stage III and stage IV patients were 36.8% and 18.7%, respectively. The median survival times of stage III and stage IV patients were 502 days and 286 days, respectively. The major toxicities were grade 3 leukopenia (16.2%), grade 3 neutropenia (32.4%), and grade 4 neutropenia (10.8%).

Perioperative course in two cases of tetralogy of fallot with portal venous atresia

We report here two rare surgical cases of tetralogy of Fallot with portal venous atresia. Both patients, previously diagnosed with tetralogy of Fallot, developed portal hypertension and showed hematemesis and/or melena. One patient needed endoscopic sclerotherapy. Intracardiac repair was performed under cardiopulmonary bypass (CPB) with moderate hypothermia. After surgery, one of the patients developed cardiogenic shock due to cardiac tamponade with accumulated chyle in the pericardial sac in the ninth postoperative day, and showed deteriorated liver function, suggesting that liver might have been vulnerable because of the absence of portal blood.

[Transportation for a pediatric heart transplant candidate to Germany]

A 8-year-old girl who underwent a total cavopulmonary connection as an one-staged repair for tricuspid atresia (Ic) had had a progressive dilated cardiomyopathy. Despite of any medical support, her left ventricular ejection fraction had been ranged from 10% to 20% since 4 months after Fontan operation. This patient was decided to apply for a heart transplantation in Germany 17 months after Fontan operation. An administration of the sufficient amount of inotropics and oxygen, volume resuscitation, reduction of the peripheral circulation at the time of take-off, and a meticulous monitoring may contribute to the successful transportation of the critically ill patient.

Atrioventricular groove patch plasty for anatomically corrected malposition of the great arteries

OBJECTIVE

In anatomically corrected malposition of the great arteries, dextroposition of the posterior pulmonary artery and levoposition of the anterior aorta are associated with the leftward deviation of the proximal portion of the right coronary artery away from the right atrioventricular groove. This anatomic feature allows a transannular subpulmonary patch plasty of the right ventricular outflow tract along the right atrioventricular groove between the right coronary artery and the tricuspid anterior anulus (ie, atrioventricular groove patch plasty) for relief of subpulmonary stenosis without jeopardizing the right coronary artery.

METHODS

This report describes the midterm results of a new surgical technique, atrioventricular groove patch plasty with a monocuspid transannular patch for subpulmonary stenosis, in 3 patients with anatomically corrected malposition of the great arteries, along with a concomitant closure of ventricular septal defects.

RESULTS

Postoperative catheterization revealed adequate relief of pulmonary stenosis, with a pressure gradient of 8.0 +/- 3.5 mm Hg and with normalized right ventricular pressure (33 +/- 10 mm Hg), contributing to excellent midterm results with no late death and reoperation during a postoperative follow-up period of 70 +/- 47 months.

CONCLUSION

This technique provides a promising alternative to Rastelli-type conduit repair for subpulmonary stenosis in anatomically corrected malposition of the great arteries.

Telomerase activity as an indicator of malignant potential in iodine-nonreactive lesions of the esophagus

BACKGROUND

Iodine-nonreactive lesions of esophageal epithelium often are associated with dysplasia and carcinoma. The authors examined the usefulness of telomerase activity as an indicator for esophageal carcinogenesis in such lesions.

METHODS

Telomerase activity was measured using the telomeric repeat amplification protocol assay in 18 samples of iodine-nonreactive lesions apart from the primary tumor in surgically resected specimens obtained from patients with esophageal squamous cell carcinoma (ESCC) and 55 endoscopic punch biopsies of iodine-nonreactive lesions obtained from 25 patients with ESCC and 30 patients who had undergone endoscopic examination for other reasons.

RESULTS

Ten of 18 iodine-nonreactive samples (56%) obtained from surgically resected specimens showed telomerase activity. In all ten telomerase positive samples, carcinoma in situ (CIS) was observed in iodine-nonreactive mucosa by light microscopy. In eight telomerase negative samples, no tumor tissue was observed in iodine-nonreactive lesions. In a parallel study, telomerase activity was detected in 28 of 55 endoscopic punch biopsy specimens (51%). CIS was observed in 25 of 28 iodine-nonreactive lesions with positive telomerase activity (89%), and tumor tissue was not observed in the other 3 samples (11%), which included 2 cases of severe dysplasia and 1 case of moderate dysplasia. No tumor tissue was observed in any of the 27 telomerase negative samples.

CONCLUSIONS

Positive and negative telomerase activity was found to be correlated with the presence and absence, respectively, of immortalized tumor cells in iodine-nonreactive lesions. The measurement of telomerase activity in iodine-nonreactive lesions independently contributes to the selection of an appropriate therapeutic strategy.

[Midterm results of total aortic root replacement with pulmonary autograft (Ross operation)]

Between February 1995 and December 1999, 18 patients underwent Ross operation. Age at the operation ranged from 2 to 31 years. Diagnosis includes congenital aortic stenosis and/or regurgitation in 15, and adult aortic regurgitation in 3. In all cases autograft was implanted by the method of total aortic root replacement, associated with annuloplasty for the dilated aortic annulus in 2 and aortoventriculotomy by the Konno procedure in 3 (Ross-Konno). Right ventricular outflow tract was reconstructed by a pulmonary homograft in 12, a xenopericardial conduit in 3, or the other reconstructive procedures with autologous tissue and outflow patch in 3. There was no operative and late death. Reoperation was needed in 1 patient due to stenosis of pericardial conduit 4 years after the initial operation. Pressure gradient across implanted autograft valve was negligible (4.8 +/- 0.5 mmHg), and echocardiography revealed no aortic regurgitation in 12 cases and trivial to mild in 6, over a mean follow-up period of 23 +/- 18 months (range 2 to 60 months), signifying excellent durability of implanted autograft. Right ventricular outflow tract reconstruction with the homograft resulted in excellent mid-term performance as showing pressure gradient of 9.0 +/- 4.6 mmHg and no regurgitation in 11 of 12 cases, whereas pressure gradient was 17.9 +/- 13.1 mmHg in the patients underwent the other reconstructive procedures. We conclude that Ross procedure associated with the concomitant procedures to adjust the size discrepancy between the native aortic annulus and autograft has provided good midterm results with excellent autograft durability. And this procedure was thought to be a preferable method for children as well as young adults with congenital aortic stenosis.

Clinical significance of telomerase activity in the non-cancerous epithelial region of oesophageal squamous cell carcinoma

BACKGROUND

The aim of this study was to examine telomerase activity in affected and adjacent tissue in patients with oesophageal squamous cell carcinoma (SCC).

METHODS

Telomerase activity was measured in oesophageal SCC cells, normal oesophageal culture cells, primary cancer tissues and adjacent normal tissues from patients with oesophageal SCC using a polymerase chain reaction-based assay.

RESULTS

All oesophageal SCC cells had telomerase activity, whereas normal cultured cells showed no activity. All 57 cancer tissues showed telomerase activity compared with only five (10 per cent) of 50 normal tissues. Cancer cells infiltrating the vessels of mucosal or submucosal tissues in non-cancerous regions were detected in four of five telomerase-positive normal tissues, whereas such infiltration was detected in only three of 45 telomerase-negative normal tissues.

CONCLUSION

In patients with oesophageal SCC, measurement of telomerase activity in normal epithelium is a highly sensitive method of detecting the microinvasion of cancer cells.

[Telomerase assay for diagnosis of esophageal cancer]

Esophageal squamous cell carcinoma is one of the aggressive diseases that has poor outcome. Therefore it is appeared that early diagnosis is very important for improving its outcome. Iodine staining method is useful for detecting the abnormal squamous epithelium and unstaining lesions by iodine contain the early esophageal cancers. Recently, telomerase activity that provides an immortal capacity for the cells has been measured in many tissues. We measured the telomerase activity in the samples of unstaining lesion by iodine using a polymerase chain reaction-based assay and described the relation between telomerase activity and histopathological findings.

[Some techniques for the correction of the congenital heart disease with autologous flap]

14 living flaps in 8 children were used to repair for the congenital heart disease, because artificial material and xeno grafts were shrunk in growing children but living flaps were going to glow with children. It were possible to use the living flaps to reconstruct of pulmonary outflow in truncus arteriosus, for septoplasty in partial anomarous of pulmonary venous return and reconstruction of unloofed coronary sinus in endocardial defect with triatriatum and intraatrial tunnel in TCPC or Fontan type operation.

Case report: Metachronous early gastric carcinoma in a reconstructed gastric tube after radical operation for oesophageal carcinoma

The incidence of double cancer has increased as a result of the significant advances in both diagnostic procedures and anti-cancer therapy, and as the outcome of oesophageal squamous cell carcinoma (ESCC) has improved, the number of cases of double cancer of the oesophagus and stomach has also increased. Two patients with metachronous early gastric carcinoma in a reconstructed gastric tube were successfully treated after subtotal oesophagectomy for ESCC. These cases have shown that early diagnosis of second cancer is very important for curative therapy.

Altered p16/MTS1/CDKN2 and cyclin D1/PRAD-1 gene expression is associated with the prognosis of squamous cell carcinoma of the esophagus

The p16/MTS1/CDKN2 gene and the cyclin D1/PRAD-1 gene cooperatively regulate cyclin-dependent kinase 4-mediated phosphorylation of pRB in the cell cycle of normal cells. p16/CDKN2 gene and cyclin D1/PRAD-1 gene alterations have been detected in squamous cell carcinoma cell lines and in several primary squamous cell carcinomas of the esophagus. We immunohistochemically assessed p16 and cyclin D1 expression in 111 squamous cell carcinomas of the esophagus after evaluation of the antibodies against p16 and cyclin D1 protein using four squamous cell carcinoma cell lines. Loss of p16 expression was detected in 56 of 111 cases (50%). The mean number of metastatic lymph nodes without p16 expression was significantly higher than the number of nodes with p16 expression (P = 0.04). The postoperative survival rate for patients without p16 expression was significantly lower than that of patients with p16 expression (P = 0.04). Cyclin D1 overexpression was found in 28 of the 111 cases (25%) and correlated with distant organ metastasis after curative surgery (P = 0.05). The survival rate of patients with cyclin D1 overexpression was significantly lower than that of patients without cyclin D1 overexpression (P = 0.01). A positive correlation between the loss of p16 expression and cyclin D1 overexpression was observed (P = 0. 03). The loss of p16 expression and overexpression of cyclin D1 may be useful prognostic indicators in patients with squamous cell carcinomas of the esophagus. It may be possible to select more suitable treatment for patients with squamous cell carcinomas of the esophagus by evaluating the status of p16 and cyclin D1 expression.

[Comparison of left ventricular pressure-volume loops measured by two-dimensional echocardiography and a conductance catheter]

A left ventricular pressure volume loop (PV loop) is useful not only in evaluating cardiac function, but also in predicting the postoperative hemodynamic state. There are two methods available for the intraoperative measurement of a PV loop: a conductance catheter and two-dimensional echocardiography. Although the accuracy of conductance catheter is well established for the measurement of ventricular volume, however, the accuracy of echocardiography remains controversy. This paper describes the relationship of parameters including volumes and Emax calculated with each method. Six patients who underwent open heart surgery were included in this study. Comparison of the absolute volumes at four points at the corners of the PV loop showed a Pearson's correlation coefficient of 0.62 (p-value < 0.01). In comparison with the relative volumes at four points which reflect the preoperative to postoperative change ratio, the correlation coefficient was 0.74 (p < 0.01). The correlation coefficients were 0.76 (p = 0.16) and 0.63 (p = 0.29) for the ratio of the end-diastolic and end-systolic volume respectively. Each preload-varying "Emax: out" (r = 0.84, p < 0.01) were highly correlated. As a predictor of cardiac oxygen consumption, each PVA (r = 0.84, p < 0.01) was highly correlated. We conclude that the measurement of left ventricular volume using two-dimensional echocardiography is as reliable as the conductance catheter.

[Successful direct embolectomy for acute massive pulmonary thromboembolism]

A 35-year-old woman was bedridden because of a fall and developed pulmonary embolism after venous thromboembolism of lower extremity. Although anticoagulation therapy was immediately carried out, hemodynamics deteriorated gradually into the state of class IV in Green-field's classification. As a result, an urgent surgical procedure was performed. Under moderate hypothermic cardio-pulmonary bypass, the aorta was cross-clamped and the pulmonary artery was opened. An 18 gram clot was taken out directly and other small pieces of clot were removed with a fiberscope, a Fogarty catheter and an aspirating tube. After surgery the patient recovered from symptoms efficiently. Some cases of acute pulmonary thromboembolism have been reported, however, the generalized classification and surgical indication for this disease have not been established yet. But, as all of reports mentions, surgical procedure is recommended positively to these cases that resist anticoagulation therapy.

[Clinicopathological study on primary lung cancer--immunohistochemical expression of p53 suppressor gene and bcl-2 oncogene in relation to prognosis]

Two hundred and eleven surgically resected primary lung tumors were studied immunohistochemically. According to histologic type, they were 129 adenocarcinomas, 56 squamous cell carcinomas, 4 small cell carcinomas, 8 large cell carcinomas, 8 adenosquamous cell carcinomas, 5 so-called carcinosarcomas and 2 other tumors. Immunohistochemical expression of p53 and bcl-2 was studied in relation to the disease-free survival. Among the 211 patients with lung cancer, 109 were positive for p53 expression, and there was no significant relationship between p53 expression and sex, or clinicopathological stage and size of the tumor, although the patients with squamous cell carcinoma had a significantly higher frequency of p53 expression than those with adenocarcinomas. The frequency of p53 expression was significantly higher in the patients with poorly differentiated adenocarcinomas than in those with other histologic types. Seventy four of the 211 patients were positive for bcl-2 expression and bcl-2 expression was higher in the stage I patients and patients with small lung tumors 2cm or less in diameter than in the other patients. The patients with adenocarcinoma had a higher frequency of expression than those with squamous cell carcinoma but no difference was found in the histological differentiation of the tumor. The 5-year survival of patients positive for p53 expression was poorer than that of those with negative expression and the survival rate was higher in the patients positive for bcl-2 expression than in those with negative expression. These findings suggested that the expression of p53 and bcl-2 is a useful marker of follow-up and prognosis, but will require more data concerning the mechanism of carcinogenesis. Seven cases of primary lung cancer were examined for genetic abnormality of the p53 gene. cDNA was synthesized from total RNA of primary tissues of lung cancer using oligo (dT) primer and reverse transcriptase and polymerase chain reaction (RT-PCR), and PCR-single strand conformation polymorphism (SSCP) analysis were performed. Five patients gave a positive result upon PCR-SSCP analysis of the p53 gene. To confirm the results of PCR-SSCP analysis, their nucleotide sequences were further analyzed and four of them had point mutations at different codons (154, 176, 207, 236) and one had deletion of one nucleotide (245) in exon 5 and 8. Fifteen percent of 26 patients with small peripheral lung adenocarcinomas less than 2cm in diameter were already advanced in stage and various factors such as vascular invasion, pleural involvement and degree of scar grade were higher than in patients with clinicopathological stage I. In advanced cases, the frequencies of p53 expression was higher than in stage I cases. Concerning the relationship of the degree of scar grade to PDGF-B expression, we demonstrated the production of PDGF-B protein immunohistochemically and the expression of PDGF-B-mRNA by In situ hybridization in the adenocarcinoma cells and macrophages of the lung tumors. However, no significant correlation was observed between the degree of PDGF-B expression and collagen production in the fibrotic focus.

Total cavopulmonary connection without the use of prosthetic material: technical considerations and hemodynamic consequences

Total cavopulmonary connection with use of an autogenous intraatrial tunnel to create a straight tube between the inferior vena cava and the pulmonary artery was attempted in several types of cardiac anomaly in eight consecutive candidates for the Fontan operation. A small right atrium with an extraordinary location of the inferior vena cava and a short superior vena cava prevented the use of this procedure in two cases. By preserving the crista terminalis and the sinus node and its arteries we prevented the development of postoperative atrial arrhythmias in the short follow-up period, and the P trigger-signal averaged P waves were not different from those of other cardiac anomalies. The proximal stump of the superior vena cava was not incised in any case to enlarge the anastomosis, even when size mismatch between the superior and inferior venae cavae existed, as in a case of bilateral superior venae cavae. Stretching the vessels by approximately 150% was possible and permitted an adequate anastomosis. Cavopulmonary connections via the intraatrial tunnel ensured smooth, nonturbulent, somewhat pulsatile flow without a pressure gradient. We concluded that the creation of an autogenous intraatrial tunnel was possible in many cases without serious complications and that this procedure has potential benefit for the pulmonary circulation in the aspect of pulsatility.

[New configuration of right ventricular dynamic cardiomyoplasty by latissimus dorsi for hypoplastic right ventricle]

The purpose of this experimental study is to evaluate the efficacy of linear-type right ventricular (RV) dynamic cardiomyoplasty in a setting of patch enlargement model for hypoplastic RV. In 6 puppies (6-8 kg), under a cardiopulmonary bypass (CPB), RV free wall and septal traveculation were resected and replaced with large pericardial patch, simulating RV patch enlargement of hypoplastic RV. A pedicled left LD, anchored to 3rd rib, wrapped onto the RV patch in parallel to RV long axis, while LD fixed to only RV diaphragma surface without wrapping LV surface. After the termination of CPB, LD flap was synchronously paced at 1:1 ratio with cardiac beat with a trained-pulse stimuli (10-25 Hz). RV performance was tested by RV function curve (RVSWI vs CVP) and RV pressure-volume relationship (ESPVR) assessed by conductance catheter.

RESULTS

LD graft stimuration showed significant augmentation of PAP (145 +/- 21%), PA flow (152 +/- 21%) and AP (128 +/- 23%) at CVP of 10 mmHg. RV function curve and ESPVR confirmed dramatical augmentation of RV performance by graft stimulation, which was identical to preoperative normal RV function even at the low CVP range.

CONCLUSIONS

Linear LD myoplasty after patch enlargement of RV may viable surgical option for hypoplastic RV.

[One and one half ventricle repair for pure pulmonary atresia--a case report]

One and one half ventricle repair consisting of the Glenn operation and the right ventricular outflow tract reconstruction was performed in a 4-year-old boy. The diagnosis of this patient was pure pulmonary atresia. He had undergone Brock's operation, Blalock-Taussig shunt and a central shunt at neonatal period. At the time of one and one half ventricle repair, the connection between the superior vena cava and the right atrium was left open. Although the RVEDV was 34.3% of normal, the topology of the right ventricle was tripartite. At three months after one and one half ventricle repair, RVEDV increased up to 52.7% of normal. This data suggests that a further definitive surgery, i.e., complete biventricular repair could be applicable in the future.

[Effects of amrinone on left ventricular function following open heart surgery--analysis with left ventricular pressure volume loops]

The effects of Amrinone on cardiac function soon after extracorporeal circulation (ECC) were studied in 5 patients including mitral valvuloplasty, VSD closure, Fontan operation and coronary AV fistel closure. In all patients, left ventricular volume load decreased postoperatively. To evaluate the efficacy, we obtained left ventricular pressure-volume loops (P-V loop) before and after ECC and after intravenous administration of Amrinone (1 mg/kg) following ECC. P-V loops were produced by measuring left ventricular pressure using a Miller catheter which was retrogradely advanced from the ascending aorta into the left ventricle and by measuring left ventricular diameter to calculate left ventricular volume with Teichholtz' formula. Although no apparent difference of Emax was recognized before and after ECC, Emax increased from 3.2 +/- 2.5 mmHg/cm3 to 5.9 +/- 4.7 mmHg/cm3 after the administration of Amrinone. The left ventricular "systolic" pressure-volume area (PVA) which is the sum of stroke work (SW) and elastic potential energy decreased from 34.4 +/- 16.4 gm to 30.9 +/- 17.8 gm after Amrinone. No difference was also recognized in left ventricular end-diastolic pressure. Ejection fraction increased from 50 +/- 17.5% to 56.1 +/- 17.3%. These results suggested that Amrinone could improve the left ventricular function without prominent change in myocardial oxygen consumption immediately after open heart surgery.

[Changes in left ventricular pressure volume loop of Lutembacher syndrome]

A 49-year-old woman with Lutembacher syndrome, atrial septal defect (ASD), mitral stenosis (MS), tricuspid regurgitation and cardiac cachexia underwent a mitral valve replacement with a 27 mm CarboMedics valve, patch closure of ASD and tricuspid annuloplasty to 29 mm by DeVega's method. The pressure volume loop (PV loop) was measured, both preoperatively and postoperatively (immediately and two months after the operation) by a Miller catheter and echocardiogram. The left ventricular stroke work (LVSW), left ventricular end diastolic volume (LVEDV) and left ventricular end diastolic pressure (LVEDP) markedly increased immediately after the operation. LVSW and LVEDV further increased, whereas LVEDP decreased with improvements in diastolic compliance two months after the operation. It was likely that those change of LV function was a sum of simple ASD and MS both of which have similar but less significant characters than Lutembacher syndrome.

[Present status of cardiomyoplasty]

Direct ventricular assist and myocardial replacement using skeletal muscle, so-called dynamic cardiomyoplasty, are promised as an effective treatment of choice in severe cardiac failure. Owing to the use of autologous muscle, the risk of rejection can be ignored, which is problematic in cardiac transplantation. More than 300 cases have been reported in the world. Since a cardiac transplant protocol has not been started yet in our country, we are hoping that clinical experience with these treatments solves our problem.

[Report of a case of the anomalous origin of the right coronary artery from the pulmonary artery with atrial fibrillation and bradycardia]

A 62-year-old man who was referred to implantation of pacemaker on account of severe bradycardia revealed anomalous origin of the right coronary artery from the pulmonary artery on aortography. The aortic root cineangiogram demonstrated single left coronary artery arising from the aorta with retrograde filling of the right coronary artery (RCA) which drained into the main pulmonary artery. Chest X-ray revealed marked cardiomegaly and treadmill exercise test shows positive at stage 2 of the Bruce protocol. Operation was performed under cardiopulmonary bypass. Although we tried to transplant the RCA to the aorta, the arterial wall was very fragile and could't bear arterial pressure. Therefore the RCA was ligated at its origin and disconnected from the pulmonary artery. Post operative course was uncomplicated and the patient was discharged without any symptoms.

Dynamic aspects of AMPs in the kidney in physiological conditions--their metabolism and turnover

The past few decades have witnessed a number of studies on AMPs in the kidney. Almost all of these studies, however, have dealt with the quantitative and qualitative analysis of AMPs in the kidney using biochemical techniques, whereas the dynamic aspect of AMPs in the kidney has been overlooked and its metabolism and turnover have never been emphasized. On the other hand, the kidneys removed from humans and experimental animals revealed a wide variety in interstitial tissue in the medulla microscopically and in the papilla of the kidney macroscopically. The reasons for these variations in the medulla, its mechanism and the matrical component have not yet been clarified. In an effort to clarify these points, we herein describe our study on the dynamic aspect of AMPs in kidney histologically in relation to their biological turnover which we employed several staining methods. Our results revealed that there was a very active turnover of AMPs present in the kidney confirming that the kidney plays an important role physiologically in AMP metabolism. The degree of the turnover of AMPs in the kidney varies from case to case. In the active phase, AMPs are excreted in the glomerulus and reabsorbed in the proximal portion of the collecting tubules. Most of the absorbed AMPs are finally drained through the lymphatic vessels in situ and a few are excreted into the urine. Contrary cases have been demonstrated, however, only were a few AMPs were noted throughout the nephrons in the kidney. AMP turnover in the kidney is unexpectedly remarkable. The medulla, which has been considered less important, in fact, plays a key role in AMP metabolism.

Full-thickness dynamic cardiomyoplasty of the left ventricle with free revascularized latissimus dorsi myografts. An experimental feasibility study

Dynamic cardiomyoplasty, with use of a free latissimus dorsi myograft revascularized by the internal thoracic artery and vein, was performed in eight dogs subjected to electrical preconditioning for 8 to 12 weeks (group I) and in six unconditioned dogs (group II). The procedure was performed after the resection of the anterior wall of the left ventricle. Cardiac output and left ventricular stroke work were augmented by 23.7% +/- 9.4% and 44.1% +/- 15.9% after graft pacing with 50 Hz burst stimulation at a 1:1 synchronization ratio, while left atrial pressure ranged from 8 to 12 mm Hg. Analysis of the left ventricular function curve showed that graft pacing at rates of 1:1, 2:1, and 3:1 augmented global left ventricular function. Hemodynamic benefit by continuous pacing at a 3:1 ratio was seen for 1.97 +/- 1.90 hours (0.5 to 6.1 hours) in group I until complications unrelated to the graft terminated the study, while it lasted for only 0.19 +/- 0.09 hour in group II. During the stimulation, the ratio of the lactate output to the oxygen consumption of the graft in group I, a possible indicator of metabolic shift, was significantly less than in group II, (0.46 +/- 0.58 and 6.34 +/- 1.73; p < 0.01). We conclude that free grafts of transformed latissimus dorsi muscle can augment global left ventricular performance, with a physiologic preload by oxidative metabolism, and provide a viable option in full-thickness dynamic cardiomyoplasty.

[Experimental study on potential for cardiac assist by latissimus dorsi myograft--an importance of muscle ischemia]

We have studied contractile property and fatigue rates of skeletal muscle ventricle (SMV) constructed using the latissimus dorsi muscles of 11 dogs. The role of early interruption of collateral blood supply in the prevention of muscle ischemia and SMV fatigue was evaluated. Systolic function of SMV was measured in a hydraulic test system; afterload was set at 70 mmHg and preload 15 or 25 mmHg. Control SMV (GI: N = 7), which was fashioned immediately after interruption of collateral blood supply, generated an initial SMV pressure of 222 +/- 50 mmHg and stroke volume of 15 +/- 7 ml/beat with muscle stimulation at a burst-frequency of 50 Hz, but could sustain flow for only 3.5 +/- 0.8 minutes. SMV subjected to a vascular delay (Group II: N = 4) demonstrated improvement of fatigue rates; duration of flow 32.4 +/- 14.0 and sufficient contractile property (initial SMV pressure 182 +/- 17 mmHg, stroke volume 1- +/- 2 ml/beat). Thermography surface temperature mapping revealed remarkable improvement of blood distribution in GII muscles. Flow rates of thoracodorsal artery were significantly greater in GII muscles compared to those in GI muscles (15.0 +/- 3.7 ml/min/LD 100 g, 10.1 +/- 3.1 ml/min/LD 100 g, p less than 0.05, respectively). Despite significant improvement of functional durability in GII muscles, the ratio of oxygen consumption to lactate output was not different between 2 groups. These results suggest that early interruption of collateral blood supply can minimize muscle ischemia, resulting in diminishing fatigue of latissimus dorsi muscles without changes in skeletal muscle metabolism.

[Potential for left ventricular assistance by latissimus dorsi myograft--sequential effects of electrical preconditioning on skeletal muscle fiber type, blood flow and metabolic status]

In order to evaluate the possibility of left ventricular assistance by latissimus dorsi (LD) myograft, we have studied contractile property and fatigue rates of skeletal muscle ventricle (SMV) constructed using canine LD muscles. Twenty three dogs were divided into 3 groups depending on the conditioning protocol of LD muscles; Group I (Control n = 12), Group II (Vascular delay n = 4) and Group III (Vascular delay and electrical preconditioning n = 7). SMVs in GIII dogs generated sufficient pressure and forward flow in a hydraulic test system with muscle stimulation at a burst-frequency of 50 Hz (SMV pressure 131 +/- 42 mmHg, Stroke volume 7.0 +/- 3.0 ml/beat). Although SMVs in GI and GII dogs could sustain flow for only 4.0 +/- 1.1 minutes and 32.4 +/- 14.0 minutes, respectively, SMVs in GIII were able to pump continuously for 107.5 +/- 15.0 minutes (p less than 0.01, vs GI and GII). Thermography surface temperature mapping revealed marked improvement of blood distribution of LD muscles in GII and GIII dogs. Flow rates of thoracodorsal artery during SMV stimulation were GI: 10.0 +/- 3.1 ml/minute/LD 100 g, GII: 15.0 +/- 3.7 ml/minutes/100 g and GIII: 20.7 +/- 2.5 ml/minutes/100 g (p less than 0.01 vs GI). The ratio of oxygen consumption to lactate output was GI: 0.33 +/- 0.10, GII: 0.36 +/- 0.09 and GIII: 1.56 +/- 0.97 (p less than 0.01 vs GI, p less than 0.05 vs GII). Histochemical examination of LD muscles using alkaline ATPase stain revealed muscle fiber type transformation of GIII muscles. These results suggest electrically preconditioned LD muscles have sufficient contractile property for partial left ventricular assistance, and highly fatigue-resistant properties resulted from muscle fiber transformation, improved muscle perfusion and metabolic changes.

[Analysis of 293 cases of hepatocellular carcinoma of recent ten years--II. Diagnosis, therapy and prognosis]

Two hundred and ninety-three cases of hepatocellular carcinoma (HCC) of recent ten years during 1979 and 1988 were analysed on its diagnosis, therapy and prognosis. Angiography was the most useful diagnostic method for the first 5 years. During recent 5 years and for the tumor with size less than 2 cm, however, ultrasonography was the best method. 24.7% cases showed negative AFP and only 42.5% cases showed the level over 400 ng/ml. According to the tumor occupying-rate at the diagnosis, the number of cases of E1 had increased annually, the other cases being unchanged. 88.6% cases had liver cirrhosis microscopically as being reported previously. As a therapy TAE was most frequently performed, followed by operation, arterial infusion of antitumor drugs et al. The prognosis of the patients depended on the tumor occupying-rate. For the case of E1, the prognosis was the best by the therapy of ethanol injection therapy, operation and TAE. For the cases with tumor of larger than E1, frequent TAE was the best. From these results we concluded that we must make efforts to find small tumors to get the good prognosis.

[Analysis of 293 cases of hepatocellular carcinoma of recent ten years--I. Epidemiology, anamnesis and tumor occupying rate]

Two hundred and ninety-three cases of hepatocellular carcinoma (HCC) admitted to the key hospital of the rural area of western Japan, Saga Prefectural Hospital, during 10 years since 1979 to 1988 were analysed retrospectively. The male to female ratio was 3.7 to 1 and the ratio of HBs-Ag positive to negative was 3.5 to 1. The peak of the age distribution was seventh decade. The incidence increased annually, especially in HBs-Ag negative males. Their past history of blood transfusion was considered as an etiology of HCC in 19 (9.9%). The HCC was diagnosed approximately 10 years earlier in habitual drinkers than non-habitual drinkers of both positive and negative HBs-Ag. The incidence of small tumors is associated with the past history of chronic liver disease, negativity of HBs-Ag, lack of symptoms and old age.

[Aortic and tricuspid valve replacement in a case of corrected transposition of the great arteries]

It is well known that corrected transposition of the great arteries (C-TGA) is accompanied with tricuspid valve regurgitation, but very few reports have described complication of this anomaly with aortic valve regurgitation (AR). We have performed aortic valve replacement (AVR) in a case of C-TGA associated with AR which had been evaluated the grade of 3/4 according to Sellers' classification, simultaneously done the valve replacement for the dysplastic tricuspid valve and annuloplasty for the right-side atrioventricular valve (mitral valve). The patient has a favorable postoperative course.

[A case of lung metastasis of thyroid cancer with endobronchial polypoid growth]

A case of a 73-year-old woman, complaining of exertional dyspnea and hemoptysis, is reported. About twenty years earlier, she had been diagnosed as having a thyroid carcinoma and had undergone a partial thyroidectomy. Bronchoscopic findings showed an endobronchial polypoid tumor which obstructed the intermediate bronchus almost completely. The polyp was about 3cm in length and protruded from the entrance of the middle lobe bronchus. The histologic findings revealed it to be a metastasis of the papillary thyroid carcinoma. After a polypectomy, the hypoxemia and dyspnea showed remarkable improvement.