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Biomedical subjects

E Okamoto

Publications and source records attributed to E Okamoto.

At least 127 records · Page 7Linked to original sources
PubMed1994

Intra-arterial alcoholization of advanced hepatocellular carcinoma.

For the purpose of achieving emergency hemostasis of a ruptured hepatocellular carcinoma (HCC) or prevention of such rupture, we applied a new method of transcatheter therapy: intra-arterial alcoholization. Five patients with a ruptured HCC and 42 with an impending rupture were treated by intra-arterial injection of absolute ethanol mixed with an equal volume of iodized oil, Lipiodol (EtOH-Lp). The tumor size ranged from 4 to 26 cm (mean 7.8 cm) in diameter. The catheter tip was placed in the segmental branch or a more distal position of the hepatic artery, and 2-40 (mean 10.6) ml of EtOH-Lp was infused under fluoroscopic guidance. Infiltration of ethanol into the HCC mass was recognized as a dense deposition of Lipiodol on plain abdominal X-rays and computed-tomography. In all five cases of ruptured HCC, hemostasis was achieved. In all 42 cases of impending rupture, tumor rupture was prevented, and all except 3 patients could be discharged. No significant complication of the gastrointestinal tract or biliary tract was seen. The incidence and severity of postembolization syndrome was markedly lower than those seen in cases treated with Gelfoam embolization.

Adolescent↗
PubMed1994

Immaturity of the myenteric plexus is the aetiology of meconium ileus without mucoviscidosis: a histopathologic study.

The most common aetiology of meconium ileus is a deficiency in trypsin activity caused by cystic fibrosis. The pathogenesis of meconium ileus without mucoviscidosis is less well understood, although a number of causative factors have been suggested. The symptoms and clinical course of nine patients with meconium ileus without mucoviscidosis were reviewed, and the myenteric plexus of a surgical specimen of intestine was examined histologically and cytometrically. The nuclei of the intramural ganglion cells were much smaller than were seen in normal newborn infants. The nuclear areas resembled those seen in fetuses of 5-6 months gestational age, but the number of ganglion cells approached normal. This immaturity of the ganglia was observed both in the contracted distal ileum and dilated proximal ileum. Patients with an ileostomy passed solid faeces for about 1 to 2 months postoperatively, after which time the faeces became watery. The intramural ganglia were mature at the time of ileostomy closure. We conclude that immaturity of the myenteric plexus in the ileum and colon seems to be the main aetiologic factor in meconium ileus without mucoviscidosis.

Cytodiagnosis↗
PubMed1994

Extensive dissection at the porta hepatis for biliary atresia.

Dissection at the porta hepatis is the crucial step in surgery for biliary atresia. The authors describe their procedure for extensively dissecting the porta hepatis. The technique is based on an anatomic cast corrosion of the human liver, and the portal vein serves as the landmark for dissection. Lateral dissection at the hepatic hilus is critical to the procedure. On the right side, the anterior portal branches are dissected to the bifurcation of the S5 and S7 segmental portal branches, over the bifurcation of the anterior and posterior portal branches. On the left side, the liver parenchyma, which bridges the umbilical point, is sectioned, and the left portal branch is dissected to the umbilical point over the pars transversalis and taped. The fibrous mass that lies within the confines of the portal branches, including the dorsal aspect, is transected completely. This procedure was performed in 16 infants; the jaundice cleared in 93.7%.

Biliary Atresia↗
PubMed1994

Fibroblasts of neurofibromatosis type 1 showed no abnormality in p21ras-mediated response to serum in culture.

In order to disclose the possible disturbance in regulation of p21ras function in neurofibromatosis type 1, we investigated the recovery from the quiescent to cycling states of the cell cycle in the skin fibroblasts of the patients. When cells cultured in serum-dependent medium are deprived of the serum, these go into the quiescent state (G0). On being returned to the serum-containing medium, the cells re-enter S phase. The skin fibroblasts from neurofibromatosis type 1 patients, and normal subjects were brought into the quiescent state by serum-starvation, and after the re-addition of the serum, the recovery to cycling states were analysed by flow cytometry. There was no apparent difference between these fibroblasts in the progression from G0 to S phase.

Alkaloids↗
PubMed1994

A prediction scoring system to select the surgical treatment of liver cancer. Further refinement based on 10 years of use.

OBJECTIVE: This study reports further refinement of a prediction scoring system, which was established in 1980 as a guide to determine a safe limit for hepatectomy, based on 10 years of use. SUMMARY BACKGROUND DATA: In the past, whether major resection was safe was judged empirically from the net resection volume or the residual hepatic volume combined with the patient's liver function. However, such judgment was not based on objectively defined criteria. METHODS: Patients with hepatocellular carcinoma (HCC; n = 376) and metastatic cancer (n = 58) who had hepatectomy at some time from 1981 through 1990 were entered into this study. A prediction score (PS) was computed using a multiple regression equation that consists of computed tomographic scan-estimated resection rate, indocyanine green retention rate, and the patient's age. A PS greater than 55 was classified as a risky zone, a PS of 45 to 55 was considered borderline and a PS less than 45 was a safe zone. RESULTS: With HCC and chronic liver disease, all patients in the risky zone died, whereas 33% in the borderline zone died and 7.3% died who were in the safe zone. With metastatic cancer with normal liver, all patients in the risky zone died, whereas no patient in either the borderline or safe zones died. The major cause of death in the risky zone was liver failure due to excessive resection. In the borderline and safe zones, liver failure developed primarily after abdominal sepsis or pulmonary infection, particularly for those with adverse prognostic factors such as disturbed glucose tolerance, lower platelet count, and higher indocyanine green retention rate. CONCLUSION: Prediction scores can eliminate deaths related to excessive resection for patients with normal or injured livers. When patients have adverse prognostic factors, careful surgery and postoperative management is mandatory to avoid liver failure triggered by intra- or extra-abdominal sepsis, even if the score remains in a borderline or safe zone.

Aged↗
PubMed1994

Development of a compact, highly efficient, totally implantable motor-driven assist pump system.

We have developed a compact, highly efficient, totally implantable assist pump system, which consists of a motor-driven assist pump and a transcutaneous energy and optical information transmission system. The motor-driven assist pump consists of a.d.c. brushless motor and a specially designed miniature ball screw. A magnetic coupling mechanism between the blood pump and an actuator provides active blood filling via mild suction force. The controller consists of a PID follow-up controller using an 8-bit one-chip microcomputer. The volume of the pump is 350 ml, and its controller is 210 ml. Pump outflow of 5.8 L/min was obtained against a mean after-load of 100 mm Hg. The pump showed a high efficiency rate and good durability. An efficiency rate of 19-21% (pump output/motor input) was obtained during 87 days of continuous pumping. No mechanical trouble occurred for an accumulated period of 6 months.

Alloys↗
PubMed1994

[Studies on cholinergic nerve function of the aganglionic colon in murin model].

The true role of the extrinsic cholinergic nerve fibers proliferating abundantly in the aganglionic colon of Hirschsprung's disease has not yet been established. Electrophysiological and pharmacological studies using superfusion method were carried out on rectal muscle strips of piebald lethal mice, one of murine models of Hirschsprung's disease and their siblings as a control. The muscle strips were preincubated with [3H] choline in Krebs solution. The contractions and the release of [3H] acetylcholine evoked by electrical transmural stimulation of the muscle strips were measured. In addition, the contractility of muscle strips treated with acetylcholinesterase blocking agents were recorded. In the aganglionic colon, as in the normal colon, the release of [3H] acetylcholine evoked by electrical transmural stimulation was recognized. However, no contractions were evoked in the aganglionic colon. The uptake of [3H] choline in the aganglionic colon was larger than in the normal colon presumably due to the proliferated extrinsic cholinergic nerve fibers. On the other hand, the release of [3H] acetylcholine evoked by electrical transmural stimulation was smaller in the aganglionic colon. In the aganglionic colon, no contractions were evoked by acetylcholinesterase blocking agents, indicating that there is no spontaneous release of acetylcholine. In the presence of low concentration of acetylcholinesterase blocking agents, the form of contractions evoked by electrical transmural stimulation in the aganglionic colon was different from those in the normal colon. These results have indicated that in the murine aganglionic colon, the proliferated extrinsic cholinergic nerve fibers may not directly regulate the smooth muscles through the functional neuro-muscular junction. In conclusion, the proliferated extrinsic cholinergic nerve fibers is not related to the narrowing of the aganglionic colon.

Acetylcholine↗
PubMed1994

[Echocardiographic assessment of cardiac basal hypertrophy represented by increased base to mid thickness ratio (B/M ratio) in the ventricular septum and its relation to age].

The basal part of the interventricular septum may easily become hypertrophic because it is exposed to strong hemodynamic stress compared to the other portions of the left ventricle. We measured the end-diastolic interventricular wall thickness both at the base and in the midsection by 2D echocardiography in 122 normotensives, and examined whether the basal thickness increases with age. The basal thickness (B) increased with age in both sexes. In males the thickness averaged 10.1 mm in the 50-59 age group, 10.2 m in those aged 60-69 and 11.4 mm (p < 0.01) in those 70 or older compared to 9.4 mm in those aged 49 or younger. In females it was 8.1 mm (p < 0.05) in the 50-59 age group, 8.3 mm (p < 0.05) in those aged 60-69 and 10.0 mm (p < 0.01) in those 70 or older compared to 6.8 mm in those 49 or younger. Concerning the midwall thickness (M), there were no significant changes among the respective age groups in either sex. As a result, a close correlation was found between the B/M ratio, a new and simple index for basal hypertrophy, and age (R = 0.46, p < 0.01 in males and R = 0.43, p < 0.01 in females). Comparison of the B/M ratio between the two age groups 49 or younger and 70 or older was as follows; 1.08 vs 1.30 (p < 0.01) in males and 1.01 vs 1.27 (p < 0.01) in females. Increase of basal hypertrophy in the aged was clearly indicated by the B/M ratio.

Adult↗
PubMed1994

Precise diagnosis by gene analysis and successful management of delivery in three patients with type IIB von Willebrand disease.

Type IIB is a rare variant of von Willebrand disease (vWD). An affected individual's bleeding tendency and thrombocytopenia are exacerbated with pregnancy, and the proper management of these patients during delivery has not been well established. Since it is important to distinguish this disease from the platelet type vWD in order to administer the appropriate therapy, gene analysis is necessary to make the precise diagnosis. We now report the successful management of delivery in three patients, who were diagnosed as having type IIB vWD by the detection of missense mutations in the von Willebrand factor (vWF) gene (C3916-->T and C3922-->T). These changes cause Arg543-->Trp and Arg545-->Cys substitutions in the A1 domain of vWF. We were able to manage the bleeding tendency of these patients at delivery mainly with vWF concentrates to supply normal vWF.

Adult↗
PubMed1993

Combined determination of N-myc oncogene amplification and DNA ploidy in neuroblastoma. Complementary prognostic indicators.

BACKGROUND: N-myc gene amplification is a well-established prognostic indicator in neuroblastoma. Flow cytometric analysis of nuclear DNA content has shown that an abnormal nuclear DNA content in neuroblastoma is associated with a better prognosis. Because some patients with N-myc unamplified tumors have a poor prognosis, factors other than N-myc amplification may play a role in determining the clinical behavior of neuroblastoma. In the current study, the authors correlated N-myc gene amplification and flow cytometric nuclear DNA content with respect to prognosis. METHODS: Forty-one patients with neuroblastoma, including 15 screened patients, served as subjects. The copy number of the N-myc gene was determined by Southern blot analysis. DNA ploidy analysis was done on nuclei isolated from formalin-fixed, paraffin-embedded blocks. RESULTS: Of 40 specimens of neuroblastoma, 7 involved tumors containing amplification of the N-myc gene and 33 did not; 13 specimens showed DNA diploidy, and 27 showed DNA aneuploidy (including 4 with DNA tetraploidy). The Kaplan-Meier survival analysis indicated a significantly better prognosis in patients with unamplified N-myc tumors compared with those with N-myc amplified tumors (87.3% versus 28.6%, P < 0.05) and in patients with DNA aneuploid tumors compared with those with DNA diploid tumors (96.3% versus 43.0%, P < 0.001). The difference in the survival of the two extreme combinations, (e.g., 25 with N-myc unamplified and DNA aneuploidy [4 tetraploidy] versus 5 with N-myc amplified and DNA diploidy) was more significant (96.0% versus 20.0%, P < 0.001) than any other combination. CONCLUSION: Evaluations of N-myc gene amplification and DNA ploidy are complementary, and the combined determination of these two factors may be one of the most powerful prognostic indicators in neuroblastoma.

Child, Preschool↗
PubMed1993

High prevalence of overweight in inner-city schoolchildren.

The weights and heights of 1670 Harlem children aged 5 to 11 years (879 boys, 791 girls) were compared with the National Center for Health Statistics standards. The median height for age and weight for age were greater by 1.4 cm and 2.2 kg in boys and 2.7 cm and 2.8 kg in girls. Weight distribution was skewed to the right and showed a bimodal pattern. "Height-ages" were advanced by an average of 0.24 years in boys and 0.47 years in girls. Weight for height in 13.9% of girls and 13.6% of boys were above the 95th percentile. The results are consistent with early maturation. However, even after adjusting for height, shift to the right of the weight distribution persists with a large subgroup of boys and girls who are overweight.

Age Factors↗
PubMed1993

Efficacy of autotransfusion in hepatectomy for hepatocellular carcinoma.

PURPOSE: Although autotransfusion is used in a wide variety of surgical procedures, it is largely unexplored for use in oncologic operations. This study evaluates the impact of autotransfusion in hepatectomy for hepatocellular carcinoma. PATIENTS AND METHODS: Fifty-four patients with hepatocellular carcinoma underwent hepatectomy by receiving autologous blood transfusion (group 1). Fifty patients receiving homologous blood without any autologous blood were matched for comparison (group 2). RESULTS: No statistical differences were found between group 1 and group 2 patients in cumulative recurrence rates (62.8% vs 67.3%, respectively) or cumulative survival rates (61.9% vs 52.8%). Autologous transfusion reduced the mean volume of homologous blood used (814 mL vs 3466 mL). The mean postoperative hemoglobin level, platelet count, prothrombin time, and partial thromboplastin time were comparable between groups. CONCLUSIONS: Autotransfusion is a safe and effective procedure in patients with hepatocellular carcinoma undergoing hepatectomy.

Aged↗
PubMed1993

Clinical, laboratory and prognostic features of congenital large intestinal motor dysfunction (pseudo-Hirschsprung's disease).

One hundred and forty-eight cases of congenital large intestinal motor dysfunction (pseudo-Hirschsprung's disease) were reported by members of the Japanese Society of Pediatric Surgeons during the past 20 years. The disorder was defined as a congenital, non-mechanical obstruction of the intestine with the presence of intramural ganglia in the terminal rectum. Intramural ganglia were abnormal in 77 cases, normal in 42, and could not be determined in 29. Of those with abnormal intramural ganglia, 54 had immature ganglia or hypoganglionosis (oligoganglionosis), 15 had neuronal intestinal dysplasia, and eight had a segmental anomaly. Of those with a normal myenteric plexus, 22 had chronic and twelve had suspected idiopathic intestinal pseudo-obstruction syndrome; eight had megacystis-microcolon-intestinal hypoperistalsis syndrome. While cases with both hypoganglionosis and normal intramural ganglia had normal acetylcholine esterase activity, a significantly greater number of patients with hypoganglionosis lacked normal rectoanal reflexes. Patients with hypoganglionosis, chronic idiopathic intestinal pseudo-obstruction syndrome, and megalocystis-microcolon-intestinal hypoperistalsis syndrome had poor prognoses with an overall mortality of 36.9%. These findings indicate that congenital large intestinal motor dysfunction remains a serious disease of childhood.

Age of Onset↗