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Biomedical subjects

E Okamoto

Publications and source records attributed to E Okamoto.

At least 19 recordsLinked to original sources
PubMed1992

Do the tumor cells of hepatocellular carcinomas dislodge into the portal venous stream during hepatic resection?

BACKGROUND: The current study was undertaken to investigate whether or not tumor cells are dislodged into the portal venous stream during hepatic resection for hepatocellular carcinomas. METHODS: A catheter was placed using echo guidance into the portal branch through the mesenteric vein in 31 patients. Cytologic examinations were done on multiple blood samples at various operative stages. RESULTS: Tumor cells were recovered in 7 of 31 patients in whom the tumor sizes were more than 5 cm and portal invasions were found microscopically and/or macroscopically. By contrast, the remaining 24 tumors were less than 5 cm in size and showed negative portal invasions. Recovery of the tumor cells was found, not during the earlier operative stage of mobilization or rotation of the hepatic lobe, but during the later stages of hilar dissection or hepatic parenchymal dissection. CONCLUSIONS: The portal pedicles should be divided before hepatic dissection in segmentectomy and lobectomy to lessen the chance of dissemination of intravasated tumor cells.

Adult↗
PubMed1992

Heterogeneity in smooth muscle cell population accumulating in the neointimas and the media of poststenotic dilatation of the rabbit carotid artery.

Rabbit smooth muscles contain at least three types of myosin heavy chain (MHC) isoforms; SM1, SM2 and SMemb (NMHC-B), the expression of which is developmentally regulated. We have recently reported that smooth muscles with the embryonic phenotype accumulate in the neointimas produced by endothelial denudation or high-cholesterol feeding. In this study, we examined MHC isoform expression in the neointimas and the media of poststenotic dilatation of the rabbit carotid artery, and determined the phenotype of the smooth muscle cell in the dilated segment. We report here that neointimal cells in the dilated segment are smooth muscle cells with the embryonic phenotype as previously reported in our ballooning-injury study. The medial smooth muscles, however, are composed of heterogeneous population of smooth muscles which differ in stage of differentiation as determined by the MHC isoform expression. These results indicate that MHC isoforms are useful molecular markers to identify abnormally proliferating smooth muscles in diseased arteries and to understand the process of atherogenesis occurring following vascular injury.

Angioplasty, Balloon↗
PubMed1992

Pituitary and gonadal functions in patients with chordee without hypospadias.

Pituitary and gonadal functions in 16 prepubertal boys with chordee without hypospadias by stimulation of gonadotropin releasing hormone or human chorionic gonadotropin were compared to those of age-matched normal boys. The patients with chordee without hypospadias had poor follicular stimulating hormone response but pituitary luteinizing hormone reserve function was normal. Testosterone response by stimulation of human chorionic gonadotropin was not impaired in patients with chordee without hypospadias. The results suggested that chordee without hypospadias may also be categorized into hypospadias from the aspect of its pituitary and gonadal functions in addition to the embryogenesis of chordee.

Child, Preschool↗
PubMed1992

Effects of several growth factors on cultured neurofibroma cells.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder characterized by abnormalities affecting multiple tissues derived from the neural crest. The peripheral neurofibromas are numerous and sometimes reach several hundred in number. In this study, the possible involvement of several growth factors in neurofibroma growth was investigated in vitro. When explants of neurofibroma tissue were cultured, macrophage-like cells with pseudopodia migrated out first, and later took on a slender fusiform shape. These cells contained S-100 protein and were identified as Schwann cells. They did not proliferate under standard culture conditions. Nerve growth factor (NGF) was helpful in maintaining the differentiated phenotype of Schwann cells, but did not stimulate their proliferation. Immunohistochemical staining for type IV collagen revealed that some large flattened polygonal cells had a mesh of type IV collagen on the surface. These cells were perineurial cells. The proliferation of cells derived from neurofibroma was stimulated by basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and transforming growth factor alpha (TGF-alpha). In comparison with skin fibroblasts, the cells derived from neurofibroma responded to these growth factors at considerably lower concentrations. Stimulation by EGF at physiological concentrations indicated the possible involvement of EGF in the development of neurofibromas.

Cell Division↗
PubMed1992

In vitro keratin expression of hair cells.

Human hair follicles were isolated from the scalp by dispase and collagenase treatment and dispersed into a cell suspension by trypsin. These cells proliferated well and could be subcultured 7 to 8 times. The medium used was MCDB 153 HAA medium further supplemented with some amino acids, hydrocortisone, insulin, EGF, and bovine brain extract. The concentration of Ca++ was adjusted to 0.1 mM. Immunohistochemically, these cells were proved to possess keratins specific to hair forming cells.

Culture Techniques↗
PubMed1992

Establishment of an enzyme immunoassay using monoclonal antibody (HG1-219) and its application for the diagnosis of hepatocellular carcinoma.

A monoclonal antibody (MoAb HG1-219) against a human gastric cancer cell line (HuG-1) and its shedding antigen (HG1-219 Ag) was generated and a solid-phase sandwich enzyme immunoassay (EIA-219) was developed. The mean serum HG1-219 Ag concentration in normal individuals was 30.5 +/- 14.5 U/ml measured by EIA-219. When the mean +3 SD of the antigen concentration in normal individuals was used as a cut-off level, 4.3% (2/47) of patients with chronic hepatitis, 9.1% (4/44) of cirrhotic patients and 37.5% (18/48) of patients with hepatocellular carcinoma (HCC) had HG1-219 Ag above the cut-off value. The positive rates of a-fetoprotein (AFP) (> 400 ng/ml) and protein induced by vitamin K absence or antagonist-II (PIVKA-II) for HCC were 26.7% (12/45) and 33.3% (12/36), respectively. There was no significant correlation between HG1-219 Ag and AFP or PIVKA-II in patients with HCC. The combination assay of EIA-219, AFP and PIVKA-II for HCC gave the positive rate of 75% (27/36). The effect of periodic acid on the HG1-219 Ag and the inhibition of EIA-219 by CA 19-9 suggest that the epitope of HG1-219 Ag is a suger chain similar to CA 19-9.

Animals↗
PubMed1992

Testicular function in patients with hypospadias associated with enlarged prostatic utricle.

Of 485 patients with hypospadias who underwent urethrography, enlarged prostatic utricles were found in 173 (35.7%). Utricles with a higher grade of enlargement were seen mainly in patients with a severe degree of hypospadias. Serum testosterone levels before and after 3 days' treatment with human chorionic gonadotrophin were determined by radioimmunoassay in 97 prepubertal boys with hypospadias and enlarged prostatic utricles. Lower levels of serum testosterone were found after hormonal stimulation in 22 patients with high grade utricular enlargement when compared with 5 controls and 75 patients with low grade enlargement; the difference was statistically significant. This finding supports the hypothesis that utricular enlargement may be due to androgenic insufficiency during the critical period of organogenesis.

Chorionic Gonadotropin↗
PubMed1992

[Complete testicular feminization syndrome associated with thermolabile androgen receptor].

Radioreceptor assay and thermostability test for the androgen receptor in two cases with complete testicular feminization syndrome were performed in regard to the fibroblasts cultured from genital skin on the basis of dispersed whole cell binding assay (Eil et al., 1980). No [3H]dihydrotestosterone binding to the androgen receptor was observed in case 1 (receptor negative), while maximum binding capacity and dissociation constant of androgen receptor for [3H]dihydrotestosterone in case 2 were 21000 sites per cell and 1.67 x 10(-10) M (receptor positive). The specific binding of [3H]dihydrotestosterone to the androgen receptor in case 2 decreased remarkably to 6.6% after high temperature (42 degrees C) incubation in comparison with that at 22 degrees C incubation. The specific binding of [3H]dihydrotestosterone to the androgen receptor in normal controls decreased down to 81.6% at high temperature incubation. Thermostability test was useful to demonstrate qualitative abnormality of androgen receptor in receptor positive testicular feminization syndrome.

Adult↗
PubMed1992

[A study of quantitative and qualitative abnormality of androgen receptor in patients with hypospadias associated with enlarged prostatic utricle].

The prostatic utricle, a rudimentary structure present in the male prostatic urethra, is currently thought to be of mixed origin, with its cranial portion being derived from müllerian duct and caudal segment from wolffian and müllerian ducts and the urogenital sinus. Enlargement of prostatic utricle has often been demonstrated in patients with hypospadias and its incidence increased according to the severity of hypospadias. It has been suggested that insufficient androgenic stimulation of the urogenital sinus and urethral groove during the critical period of sexual differentiation may cause this entity. Since 5 alpha-dihydrotestosterone (DHT) is a major androgen for the normal development of urogenital sinus, androgen receptor levels in the patients with hypospadias associated with enlarged prostatic utricle may concern this ontogenesis. Fibroblasts derived from penile skin in these patients were assayed for androgen receptor levels using dispersed whole cell binding assay after Eil (1970). Thermostability of androgen receptor in the same fibroblasts was also evaluated by the remaining androgen receptor activity after incubation at 42 degrees C, and expressed as a ratio (percentage) to the androgen receptor activity in the incubation at 22 degrees C. Preputial skin of endocrinologically normal boys in the same range of age (3 to 8 years) was served as controls. There was a significant difference in averages of maximum binding capacities of [3H]DHT to the androgen receptor between those of controls (n = 4) and patients with grade II utricle (n = 4) (89 +/- 5.7 (SE) x 10(2) sites/cell vs. 37 +/- 7.1 x 10(2) sites/cell).(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1992

[Effects of administration of three kinds of catecholamine on mitral complex].

To evaluate cardiac injury induced by injection of 3 kinds of catecholamine, 219 male rabbits were examined. Eighty-five to 100 percent of the animals having high doses of adrenaline and noradrenaline showed ventricular premature contraction, and 65 to 75 percent of them showed mitral complex injury; whereas, these effects were identified in none or only in 10 percent of the animals with isoproterenol injection. The cardiac injury was similar to that of vagal stimulation, which was reported previously. These results indicate that ventricular premature contractions are important for developing the adrenaline- and noradrenaline-induced mitral complex injury.

Animals↗
PubMed1992

[Ectopic ureter opening to vestibule without urinary incontinence: a case report].

A case of a 2-year-old female with right ectopic ureter opening in vestibule vaginae and without urinary incontinence is reported. Excretory urogram showed mild dilatation of the upper right segment with bilateral complete duplication. Right ectopic ureter some functioning upper segment of the kidney was reimplanted into the bladder to avoid surgical intervention for heminephrectomy. According to the retrograde ureterogram of ectopic ureter the running courses and shapes of the dilated distal portions of ureters were compared between two groups, ectopic ureter with incontinence and that without incontinence. We suppose the continence mechanism of ectopic ureter is kept when the running course of the ureter through some portion of the urethral sphincter musculature.

Anastomosis, Surgical↗
PubMed1992

[A comparative study of the characteristics and social backgrounds of frail and elderly persons at home, long-stay elderly hospital patients, and residents of welfare homes for the frail elderly].

Three studies were carried out in Mino City, Osaka Prefecture, on 188 frail and elderly persons living at home (the home group), 61 elderly patients who had been hospitalized more than six months (the inpatient group), and 72 residents of welfare homes for the frail elderly (the resident group). The characteristics and social backgrounds of the three groups were compared. About 30% of each group had suffered a stroke. As for ADL score, moderate disability was dominant in the home group, severe disability in the inpatient group, and slight disability in the resident group. The proportions of those who had been living alone and those who had no spouse were significantly higher in the inpatient group and in the resident group than in the home group. Significantly fewer subjects in the resident group had been living with their offspring than in the home group or in the inpatient group. The percentage of those who did not have their own home was the highest for the resident group. Multivariate analyses using Hayashi's quantification method II were conducted for a comparison between cases belonging to the home group and the inpatient group, and between the home group and the resident group. The analysis of the home group and the inpatient group revealed a relationship of the inpatient group to severe disability in ADL, and living alone. Differences between these two groups were related to such variables as ADL, sex, living or not living alone, living or not living with offspring, and having or not having a spouse.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Isolation of two new natural pteridines from photosynthetic bacteria, Rhodopseudomonas sphaeroides.

Two new natural pteridines have been isolated from the cultured medium of Rhodopseudomonas sphaeroides GM-1. The compounds are tentatively identified as 2-amino-4-hydroxy-6-hydroxy-6-(1,2, 3,4-tetrahydroxybutyl)pteridine and 2-amino-4-hydroxy-6-(3-hydroxy-4-phosphonoxy-1-butenyl)pteridine by degradative experiments and by electrophoretic and paper chromatographic comparison with authentic materials.

Culture Media↗
PubMed1991

Flow cytometric DNA analysis of hepatocellular carcinoma.

The prognostic value of nuclear DNA content was studied retrospectively using flow cytometry in 203 cases of resected hepatocellular carcinoma. The occurrence of DNA aneuploidy, which was detected in 50% of patients, correlated significantly with tumor size and the presence of vascular invasion or intrahepatic metastasis. Overall, patients with DNA aneuploid tumors had a significantly worse prognosis than those with DNA diploid tumors (P less than 0.001) and, also in subdivided groups by tumor size (P less than 0.01). Among DNA aneuploid patients, the survival times were significantly shorter for patients with a low DNA index (less than 1.5) than for those with a high DNA index (greater than or equal to 1.5) (P less than 0.05). In a Cox multivariate analysis, nuclear DNA content provided significant prognostic value (P = 0.008), as did vascular invasion (P = 0.001) and intrahepatic metastasis (P = 0.005). These results indicated that nuclear DNA content has an important prognostic value in hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1991

Allelotype study of primary hepatocellular carcinoma.

Accumulation of mutations in oncogenes and tumor suppressor genes transforms a normal cell to a malignant cell by allowing it to escape from normal control of growth. In order to learn (a) how many tumor suppressor genes are involved in the tumor progression of hepatocellular carcinoma, (b) whether there is any association among allelic losses of chromosomes, or (c) whether integration of hepatitis B virus into host DNA influences any particular chromosomal losses, we have examined loss of heterozygosity with 44 restriction fragment length polymorphism markers in 46 cases of hepatocellular carcinoma. The markers represented all chromosomal arms except 5p, 8p, 9p, 18p, and acrocentric chromosomes. Allelic losses in tumors indicated that five tumor suppressor genes, located on chromosomes 5q, 10q, 11p, 16q, and 17p, may be involved in this cancer. However, no significant associations were observed among the various allelic losses or between the integration of hepatitis B virus and chromosomal losses. Furthermore, a deletion map for chromosome 16q indicated the localization of a tumor suppressor gene between q22 and q24 and that for chromosome 17p suggested the existence of a second tumor suppressor gene in addition to the p53 gene.

Alleles↗
PubMed1991

Significance of hemostatic molecular markers during disseminated intravascular coagulation in patients with liver cirrhosis treated by endoscopic embolization for esophageal varices.

We studied the quantitative changes of hemostatic molecular markers with time during the course of disseminated intravascular coagulation (DIC) induced by endoscopic embolization using thrombin for esophageal varices in nine patients with liver cirrhosis. The plasma levels of D-dimer, a product of plasmin degradation of cross-linked fibrin, and thrombin-antithrombin-III complex (TAT) were significantly higher in patients before treatment when compared with 60 healthy individuals. The plasma levels of TAT, D-dimer, and plasmin alpha 2-plasmin inhibitor complex (PIC) increased significantly 5-15 min after thrombin injection into the varices, earlier than the changes of conventional coagulofibrinolytic factors, reached a maximum level after 180 min, and started to decline after 1 day. Although the plasma PIC level returned to normal after 7 days, both TAT and D-dimer were still above the pretreatment level. Although there was no change in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) increased significantly after 5 min. The plasma level of plasminogen activator inhibitor type 1 (PAI-1) showed only a slight elevation after treatment. We propose that the hemostatic molecular markers TAT, D-dimer, and PIC are suitable for the early diagnosis of DIC after endoscopic embolization using thrombin in patients with liver cirrhosis and that the increase of PAI-1 is too small for the regulation of fibrinolysis due to t-PA in DIC occurring in liver cirrhosis.

Adult↗