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Biomedical subjects

S Ikeda

Publications and source records attributed to S Ikeda.

At least 235 records · Page 13Linked to original sources
PubMed1999

Enhanced growth of human vascular endothelial cells on negative ion (Ag-)-implanted hydrophobic surfaces.

Silver negative ions (Ag-) were implanted to an insulator, polystyrene, in a relatively low ion energy ranging from 5 to 30 keV, and in a dose ranging from 10(14) to 6 x 10(16) ions. cm-2. Surfaces of Ag--implanted polystyrene were studied by means of secondary ion mass spectrometry, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and micro-Raman spectroscopy, and contact angle measurement. As a result of Ag- implantation, the polystyrene surfaces underwent degradation, thereby becoming more hydrophilic with increasing dose and ion energy except an ion energy of 30 keV. The Ag- implantation in polystyrene led to enhanced growth of human vascular endothelial cells, which grew to more extent with increased hydrophilicity of Ag--implanted surfaces except an ion energy of 30 keV. Polystyrene surfaces on which Ag- were implanted up to an ion energy of 30 keV caused the same hydrophobic level as polystyrene surface itself. Nevertheless, the Ag--implanted polystyrene showed relatively good biocompatibility different from polystyrene. Such an improvement in cell adhesion may be related to the formation of a graphite-like structure on polystyrene surfaces by a Ag--implanted process. Moreover, upon plating in a high cell density, human vascular endothelial cells survived even on the polystyrene region of Ag--implanted polystyrene for longer than 1.5 months, while the cells did not grow on untreated polystyrene in the same culture conditions.

Biocompatible Materials↗
PubMed1999

Concomitant increase in neutrophil adhesion to inflammatory peritoneum and remote organs during peritonitis.

BACKGROUND: Neutrophils contribute to the host defense mechanism, but they can cause remote organ injury in peritonitis. The purpose of this study was to examine neutrophil adhesion to the peritoneum and remote organs simultaneously in peritonitis using a fluorescence microscopic method. STUDY DESIGN: Experiment 1: Sprague-Dawley rats (n = 16) were injected intraperitoneally (ip) with saline solution or 10(5), 10(7), or 10(9) Escherichia coli. Five hours after challenge, 1 x 10(6) fluorescein-labeled neutrophils were infused. Two minutes after neutrophil injection, five peritoneal samples (the greater omentum, mesentery, parietal peritoneum, colon, and ileum), both lungs, the liver, and the right kidney were harvested for counting of labeled neutrophils under epifluorescent microscopy. Lung myeloperoxidase (MPO) activity was also determined. Experiment 2: Rats (n = 23) were given 10(9) E. coli ip. Before challenge (0 h) or at 1, 5, or 10 h after challenge, labeled neutrophils were infused. Then, the labeled neutrophil numbers in organs and lung MPO activities were assessed as described for Experiment 1. Hemodynamic and arterial blood gas data were also obtained in another set of rats before and at 1, 5, 8 and 10 h after 10(9) E. coli ip challenge. RESULTS: Experiment 1: The labeled neutrophil numbers in the peritoneum, lungs, and kidney showed significant positive correlations with the injected bacterial numbers. Lung MPO also positively correlated with E. coli number and labeled neutrophil number in the lungs. Experiment 2: Labeled neutrophil numbers in the peritoneum and kidney peaked at 5 h. The pulmonary labeled neutrophil number rose, reaching a plateau at 5 h. No remarkable change was observed in the hepatic labeled neutrophil number. There was a positive correlation between lung MPO activity and pulmonary labeled neutrophil number. Hemodynamic and blood gas data reflected a hyperdynamic state. CONCLUSIONS: Concomitant dose-dependent increases in neutrophil adhesion in the peritoneum, lungs, and kidney were observed in this peritonitis model. Increased neutrophil adhesion was transient in the peritoneum and kidney but persistent in the lungs. Strategies modulating neutrophil adhesion in organs are anticipated to be useful for the treatment of peritonitis.

Animals↗
PubMed1999

Epiphrenic diverticulum composed of airway components attributed to a bronchopulmonary-foregut malformation: report of a case.

Bronchopulmonary-foregut malformation (BPFM), defined originally as pulmonary sequestration with or without communication to the esophagus, has been acknowledged to include congenital foregut diverticula. We present herein the case of a 43-year-old woman with a 9-year history of dysphagia, in whom a barium meal examination demonstrated a 2.5-cm epiphrenic diverticulum and several fistulae. A laparotomy was performed and the lower esophagus without communication to the lung was pulled down and resected, followed by an esophagogastrostomy carried out with fundopexy. Since her operation, the patient has been free of symptoms. Histologically, the diverticulum was observed to be lined by stratified squamous cells, but its shape was formed by mural cartilage, smooth muscle cells, and three ciliated-cell cysts. The dysphagia was considered to have been derived from the kinked esophagus created by the rigid diverticulum, being the possible developmental arrest of a supernumerary lung bud. These findings indicate that this case may involve BPFM in the broad sense. Although several cases of bronchogenic cysts located beneath or across the diaphragm have been reported as a subgroup of BPFM, congenital epiphrenic diverticula has rarely been described.

Adult↗
PubMed1999

Enhanced antitumor activity of a combination treatment with a mouse/human chimeric anti-MK-1 antibody and lymphokine-activated killer cells in vitro and in a severe combined immunodeficient mouse xenograft model.

Mouse monoclonal antibody FU-MK-1, raised against a human gastric adenocarcinoma, recognizes a glycoprotein antigen (termed MK-1 antigen) present on most carcinomas and seems to be valuable in immunodiagnosis and immunotherapy of various cancers. In a recent study, we constructed a mouse/human chimeric antibody, designated Ch FU-MK-1, by fusing the FU-MK-1 V(H) and Vkappa genes to the human Cgamma1 and Ckappa genes, respectively. In the present study, we tested combination immunotherapy of Ch FU-MK-1 with human lymphokine-activated killer (LAK) cells in vitro and in mice with severe combined immunodeficiency (SCID) bearing human MK-1-expressing tumors. In in vitro experiments, Ch FU-MK-1 effectively mediated antibody-dependent cell-mediated cytotoxicity (ADCC) against MK-1-expressing MKN-74 cells, which was completely blocked by an anti-FcR antibody. Since the apoptotic pathway as well as the necrotic pathway have been shown to be utilized in various cytotoxic effector mechanisms, we investigated the role of apoptosis in ADCC mediated by LAK cells and Ch FU-MK-1 against MKN-74 cells. The implication of the apoptosis during ADCC was demonstrated by means of both a terminal-deoxynucleotidyltransferase-mediated dUTP-biotin nick-end-labeling assay and a propidium iodide staining method. In vivo antitumor activity of combination treatment with LAK cells and Ch FU-MK-1 was estimated using SCID mice inoculated s.c. with MKN-74 cells. The i.v. administration of LAK cells and i.p. administration of Ch FU-MK-1 and interleukin-2 (IL-2) produced a marked growth inhibition of MKN-74 tumors in SCID mice. When the actual tumor weights were measured 16 days after initiation of treatment, more than 70% reduction was observed in the group receiving LAK cells plus Ch FU-MK-1 plus IL-2 as compared to the control untreated group. Together these results suggest that Ch FU-MK-1 may serve as a potentially useful immunotherapeutic reagent for human MK-1-expressing tumors.

Animals↗
PubMed1999

Extrahepatic biliary atresia associated with trisomy 18.

A case of extrahepatic biliary atresia (EBA) associated with trisomy 18 is presented. A 1-month-old boy was suspected to have Alagille syndrome with obstructive jaundice, a systolic heart murmur, growth retardation, and a small, pointed chin. However, surgery and chromosomal analysis revealed EBA associated with trisomy 18. Chromosomal examination must be performed in patients with jaundice and congenital anomalies. It is possible that EBA in trisomy 18 syndrome is due to a chromosomal disorder.

Bile Ducts, Extrahepatic↗
PubMed1999

On the occurrence of neuronal sprouting in the frontal cortex of a patient with Down's syndrome.

We report on the autopsy of a 52-year-old Down's syndrome patient with a 9-year history of progressive dementia. Histologically, there was a marked neuronal loss in the cerebral cortices with numerous neurofibrillary tangles and senile plaques and congophilic angiopathy. The second cortical layer was spongy in appearance and the frontal and temporal white matter showed marked myelin pallor. Immunohistochemistry for MAP2 of the frontal and temporal cortices revealed great reduction in the number of large pyramidal neurons. On the other hand, a much stronger MAP2 immunoreactivity than that seen in the controls was observed in the second layer, which consisted of many small pyramidal neurons with features of aberrant sprouting. They were recognized in the frontal cortices but not in the temporal cortices, and were not immunolabeled with phosphorylated-tau nor MAP5. On double immunolabeling with MAP2 and beta-amyloid antibodies, these neurons were found to be not directly associated with the formation of senile plaques. Ultrastructurally, MAP2 was immunolocalized in an amorphous granular form in the neuronal somata and processes, and paired helical filaments were not immunolabeled. The observation may indicate the occurrence of a remarkable plastic response of small pyramidal cortical neurons in this patient with Down's syndrome.

Amyloid beta-Peptides↗
PubMed1999

Preoperative aspirin and heparin therapy does not increase perioperative blood loss and blood product requirements in coronary artery bypass graft surgery.

PURPOSE: The effects of preoperative aspirin (ASA) and/or heparin therapy on perioperative blood loss and transfusion requirements were studied in patients undergoing primary coronary artery bypass graft (CABG) surgery using perioperative blood cell salvaging techniques. METHODS: The amounts of perioperative blood loss and transfusion requirements were recorded in four groups of patients, based on the preoperative medication: ASA group (51 patients), heparin group (33 patients), and ASA plus heparin group (38 patients), as well as a control group (49 patients who received neither of these medications). RESULTS: There were no significant differences among the four groups in cardiopulmonary bypass time, aortic cross clamp time, or the number of coronary artery grafts performed. Postoperative blood loss was highest in the ASA group, followed by the control, the ASA + heparin, and the heparin groups. Neither postoperative blood loss nor transfusion requirements showed significant differences among the four groups. Simultaneous administration of heparin with ASA also did not increase the blood loss or transfusion requirements. CONCLUSION: Preoperatively administered aspirin and/or heparin did not significantly increase perioperative blood loss or the total amount of transfusion requirements. It is not necessary to delay elective CABG if blood cell salvaging techniques are used.

Journal Article↗
PubMed1999

Effect of distal stenosis of internal thoracic artery bypass grafts on longitudinal phasic blood flow velocity characteristics.

BACKGROUND: Left internal thoracic artery (LITA) bypass conduits show gradual longitudinal transition in their phasic flow velocity patterns from the proximal to distal segments, but little is known about the influence of distal stenosis, particularly early after surgery, on that characteristic. The purpose of this study was to evaluate the influence of distal stenosis on these flow velocity patterns. METHODS: We examined 24 LITAs within 1 month (7 to 30 days) after surgery with a Doppler-tipped guide wire at the proximal, mid, and distal segments. Maximum peak velocities (MPV), time averaged peak velocities (APV), and velocity-time integrals (VTI) were measured. RESULTS: In LITAs without stenosis (n = 14, group A), the APV, MPV, and VTI values at the diastole were significantly greater than those for distal stenosis (minimal lumen diameter >75%, n = 10, group B). The values of the 3 indexes at the systole in each segment did not differ significantly between the 2 groups. Both groups showed gradual increases in the diastolic/systolic ratios of the 3 indexes from the proximal to distal portions, the ratios in group A being significantly larger than that in group B (APV, P <. 001; MPV, P <.01; TVI, P <.01, respectively). For these indexes, sensitivity and specificity for predicting stenosis of LITA was higher in the proximal and mid portion than in the distal. CONCLUSIONS: Anastomotic stenosis decreases the diastolic flow component but not the systolic one. By using diastolic/systolic ratios of the 3 indexes, it is possible to predict distal stenosis of LITA from the resting phasic flow velocity pattern.

Aged↗
PubMed1999

Surgical indications for patients with hyperammonemia.

BACKGROUND/PURPOSE: The authors surgically treated seven of eight patients with congenital portosystemic shunt and hyperammonemia. This entity is uncommon in children. METHODS: The patients included five boys and three girls with a mean age of 8 years (range, 7 months to 24 years). Preoperative symptoms included hyperammonemia. Hepatic encephalopathy was evident in five patients. Diagnosis and assessment were made by ultrasound scan, magnetic resonance imaging (MRI), angiography, and 123 I-iodoamphetamine per-rectal portal scintigraphy. Surgical banding was done for five patients and transvenous coil embolization for two. One patient was not a surgical candidate because there were no intrahepatic portal veins. RESULTS: In four of the five patients treated using surgical banding, and in both patients who underwent coil embolizations, hyperammonemia and clinical symptoms improved soon after surgery. However, in the remaining patient, hyperammonemia worsened after surgery, and reoperation was needed because of a severe portal hypertension, possibly caused by malconformation of hepatic veins. CONCLUSIONS: For patients with congenital portosystemic shunt, early diagnosis and surgery are needed to prevent damage to central nerves caused by persistent hyperammonemia. Maldevelopment of the intrahepatic portal veins is a surgical option, if the patient has a normal liver architecture, but malconformation of hepatic veins or severe anomalies such as cardiac defects would rule out surgical intervention.

Adolescent↗
PubMed1999

Successful coil embolization in an infant with congenital intrahepatic portosystemic shunts.

The authors report the case of a 7-month-old Japanese infant with congenital intrahepatic portosystemic shunts. He had hypergalactosaemia and hyperammonemia at age 1 month. The diagnosis was made by ultrasonography and angiography. Coil embolization was performed successfully, and then hyperammonemia and hypergalactosaemia improved soon after surgery.

Embolization, Therapeutic↗
PubMed1999

Cardiomyocyte apoptosis with enhanced expression of P53 and Bax in right ventricle after pulmonary arterial banding.

The aim of this study is to investigate whether the cardiomyocyte apoptosis is induced after experimental right-sided pressure overload and whether the expression of proapoptotic factor is altered or not. Ten-week-old male Sprague-Dawley rats were subjected to right ventricular overload by experimental coarctation of the main pulmonary artery. In pulmonary artery-banded rats, TUNEL method revealed that positive nuclei were observed in cardiomyocytes exclusively in the right ventricle, and Northern blot analysis showed that p53 mRNA level in the right ventricle was 6.2-fold higher at the day 1 than that in sham-operated rats and its level decreased gradually. Bax mRNA in the right ventricle was also increased 3.3-fold at the day 1 in pulmonary artery-banded rats and also gradually decreased. The immunohistochemical study revealed that the immunoreactivity of P53 and Bax was observed exclusively in the right ventricle of the pulmonary artery-banded group. These results demonstrated that the occurrence of TUNEL-positive cardiomyocytes in the acute pressure overload was accompanied by the enhanced expression of apoptosis inducers. It is suggested that acute pressure overload is a potent apoptotic stimulus for cardiomyocytes.

Animals↗
PubMed1999

Decrease in thromboxane A2 receptor expression by differentiation with dibutyryl cyclic AMP in 1321N1 human astrocytoma cells.

Thromboxane A2 (TXA2) receptor expression with its signaling was investigated in 1321N1 human astrocytoma cells differentiated with dibutyryl cyclic AMP (dbcAMP). The cells cultured in 0.5% fetal calf serum containing 0.5 mM dbcAMP for 3 days showed the star-shaped morphology, accompanied with the reduction of a TXA2 mimetic U46619-induced phosphoinositide hydrolysis and Ca2+ mobilization. Immunoblotting analysis revealed that human astrocytoma cells expressed phospholipase C (PLC)-beta1 and -beta3, but not PLC-beta2. The contents of PLC-beta1 and beta3 were not changed by the differentiation. The alpha subunit of Gq/ll bound to TXA2-receptor was reduced by the differentiation, determined by immunoblotting after immunoprecipitation with an anti-TXA2-receptor antibody. Scatchard analysis of the binding of [3H]SQ29548, a TXA2 receptor antagonist, to the membranes revealed that the maximum binding site was reduced by the differentiation. The expression of TXA2 receptor mRNA also was reduced by the differentiation, determined by reverse-transcribed-polymerase chain reaction. Although placental type of TXA2 receptor mRNA expression increased after the differentiation, endothelial type of TXA2 receptor mRNA expression slightly decreased. The results suggest that 1321N1 human astrocytoma cells differentiated with dbcAMP show impaired TXA2 receptor-mediated phosphoinositide hydrolysis and Ca2+ mobilization, due to the decrease in TXA2 receptor number.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1999

High rate of chromosomal abnormalities in HTLV-I-infected T-cell colonies derived from prodromal phase of adult T-cell leukemia: a study of IL-2-stimulated colony formation in methylcellulose.

To detect chromosomal abnormalities in prodromal phase of adult T-cell leukemia (ATL), we established a clonal culture method for human T-lymphotropic virus type I (HTLV-I) infected T-cells in methylcellulose containing recombinant human interleukin 2 (rhIL-2). We tried to analyze chromosomes of 187 colonies (4, 23, 69, 74, and 17, from HTLV-I-uninfected normal T-cells, HTLV-I-Infected normal T-cells, HTLV-I carriers, smoldering ATL, and chronic ATL, respectively), using chromosomal banding methods. In the prodromal group, 53% of colonies (84/160) (36/69, 37/74, 11/17 in HTLV-I carriers, smoldering ATLs, and chronic ATL, respectively) had chromosomal abnormal clones. In HTLV-I carriers, multiple clones with simple chromosomal abnormalities were observed. In more progressed chronic ATL, more complex chromosomal abnormalities were detected, and specific colonies were selected. Thus, colonies in the prodromal phase of ATL are characterized by cytogenetical clonal evolution and clonal changes.

Adult↗
PubMed1999

Growth hormone/insulin-like growth factor 1 axis alterations contribute to disturbed protein metabolism in cirrhosis patients after hepatectomy.

BACKGROUND/AIM: Liver cirrhosis is accompanied by a fall in whole-body protein turnover and alterations of the growth hormone (GH)/insulin-like growth factor 1 (IGF-1) axis. However, the influence of liver cirrhosis on the GH/IGF-1 axis in the perioperative period, and the contribution of the GH/IGF-1 axis alteration in cirrhosis to postoperative nitrogen metabolism are not known. METHODS: Plasma GH, IGF-1 and IGF binding protein 3 (IGF-BP3) levels were measured sequentially in patients undergoing hepatectomy with or without cirrhosis. Postoperative nitrogen excretion and whole-body protein turnover rate were also determined. RESULTS: Preoperative plasma IGF-1 level showed a negative correlation with indocyanine green retention rate. Cirrhosis patients undergoing hepatectomy had low IGF-1 and IGF-BP3 levels, despite extremely high GH levels in the perioperative period. Perioperative IGF-1 levels were lower in patients with postoperative complications than in those without complications. Postoperative nitrogen excretion was higher and whole-body protein turnover rate was lower in patients with cirrhosis than in those without cirrhosis. The post-operative IGF-1 level showed a positive correlation with whole-body protein turnover rate. CONCLUSIONS: Postoperative hepatic IGF-1 production may be severely disturbed in patients with cirrhosis, and the impaired IGF-1 production contributes to the suppressed postoperative protein metabolism in cirrhosis. It may be appropriate to increase plasma IGF-1 level in patients with cirrhosis to enhance postoperative protein metabolism and improve the postoperative outcome.

Aged↗
PubMed1999

State transitions by molecules.

In our previous paper, we described a method by which a state machine is implemented by a single-stranded DNA molecule whose 3'-end sequence encodes the current state of the machine. Successive state transitions are performed in such a way that the current state is annealed onto an appropriate portion of DNA encoding the transition table of the state machine and the next state is copied to the 3'-end by extension with polymerase. In this paper, we first show that combined with parallel overlap assembly, a single series of successive transitions can solve NP-complete problems. This means that the number of necessary laboratory steps is independent from the problem size. We then report the results of two experiments concerning the implementation of our method. One is on isothermal reactions which greatly increase the efficiency of state transitions compared with reactions controlled by thermal cycles. The other is on the use of unnatural bases for avoiding out-of-frame annealing. The latter result can also be applied to many DNA-based computing paradigms.

Animals↗
PubMed1999

Cerebral blood flow velocity during repeatedly induced ventricular fibrillation.

STUDY OBJECTIVE: To investigate the effect of induced ventricular fibrillation and defibrillation on cerebral blood flow (CBF) was investigated using a transcranial Doppler. DESIGN: Prospective clinical study. SETTING: University hospital. PATIENTS: 12 ASA physical status III and IV patients who underwent implantable cardioverter defibrillator placement during general anesthesia. INTERVENTIONS: Cerebral blood flow velocity was measured repeatedly during induced ventricular fibrillation and subsequent defibrillation. MEASUREMENTS AND MAIN RESULTS: The mean flow velocity in the middle cerebral artery was measured using a transcranial Doppler. The mean flow velocities decreased significantly immediately after ventricular fibrillation was induced, but they returned to preventricular fibrillation levels immediately after successful defibrillation. Repeatedly induced ventricular fibrillations have no cumulative detrimental effect on the CBF velocity. CONCLUSIONS: Repetitively induced ventricular fibrillation and defibrillation during the insertion of implantable cardioverter defibrillator did not show any detrimental changes in CBF. Transcranial Doppler may be a more sensitive device than other currently available cerebral monitors to detect changes in cerebral circulation during a brief episode of ventricular fibrillation and defibrillation.

Blood Flow Velocity↗
PubMed1999

Surgical correction of patent ductus venosus in three brothers.

We report the presence of a patent ductus venosus in three brothers who underwent surgical correction. Patent ductus venosus was demonstrated by ultrasonography. Portosystemic venous shunt ratios as evaluated by [123I]iodoamphetamine per rectal portal scintigraphy were 67%, 50%, and 77%, respectively. Histologic examination of liver biopsy specimens revealed fatty degeneration in all cases. Portal vein pressure before and after temporarily occluding the patent ductus venosus was estimated by an Anthron P-U catheter introduced into the portal vein via the ligament teres hepatis. Portal venous pressure increased from 10 to 17 cm H2O, 16 to 23 cm H2O, and 14 to 27 cm H2O, respectively. Therefore, banding of the ductus venosus with Teflon tape was attempted to prevent portal hypertension following complete ligation. As a result, portal venous pressures after stricture of the ductus venosus were 12, 21, and 20 cm H2), respectively. Bile acid and liver enzymes decreased and returned to normal within 14 days after surgery. Interestingly, serum concentrations of hepatocyte growth factor (HGF) increased significantly after restoration of the portal blood flow and then gradually decreased, but remained persistently elevated for at least two weeks in two cases measured after surgical correction. One month after correction, liver function returned to normal as assessed by serological and histological parameters in all cases. These results suggest that it is important to determine whether stricture or complete ligation is indicated for a patent ductus venosus during surgical correction, based on the portal venous pressure after temporal test occlusion of the duct. In addition, HGF may be a useful marker for normalization of hepatic microcirculation after surgery.

Child, Preschool↗