Biomedical subjects

E Okamoto

Publications and source records attributed to E Okamoto.

At least 145 records · Page 8Linked to original sources

PubMed1993

Outcome of 21 patients with biliary atresia living more than 10 years.

The outcome of 21 survivors (8 males, 13 females; age range, 11 to 29 years) followed for > 10 years after surgery for biliary atresia are discussed. Of the 21 patients, 18 with type III disease had hepatic portoenterostomy (Kasai operation), and 3 with type I disease had hepaticoenterostomy. Twenty patients are alive leading almost normal lives; however, 13 (61.9%) patients did have a history of complications, including hemorrhage from esophageal varices in 10, from a gastric ulcer or erosion in 3, and from a duodenal ulcer in 2; biliary reobstruction in 3; and multiple pulmonary arteriovenous fistulae in 2. Of those with complications, 7 required surgery. One died suddenly at the age of 19 years of a bleeding gastric ulcer. Liver function is normal in 9 (45.0%) of the 20 alive patients, 2 (10.0%) have slight hepatic dysfunction, and 9 (45.0%) have mild-to-moderate hepatic dysfunction. Liver function is almost normal in 3 patients who had a history of variceal hemorrhage.

Adolescent↗

PubMed1993

Expression of basement membrane components in skin equivalents--influence of dermal fibroblasts.

We have made a skin equivalent constructed of fibroblasts embedded in a type I collagen, with an overlying stratified keratinocyte epithelium to examine formation of the basement membrane. We assessed the influence of the existence and species of fibroblasts in the collagen gel. Cultured human keratinocytes were well attached to the dermal equivalent. Plating efficiency was not clearly different among several types of gel. On the control and mouse fibroblast gel, sheet formation was delayed and epithelial stratification on the human fibroblast gel was more remarkable than on the control gel. On the human fibroblast gel, we observed the expression of basement membrane components (bulbous phemphigoid antigen, laminin, type IV collagen and fibronectin) between the sheet of cultured keratinocytes and the human fibroblast gel earlier than those on the control gel and mouse fibroblast gel. Type VIII collagen was not observed in any of the models at 4 weeks.

Adolescent↗

PubMed1993

Main trends in hospital use in different cities in Japan.

In this study, trends in hospital use were identified in Japanese cities. Data for all inpatient care in May 1985 (9,555 patients) and in May 1988 (11,205 patients) paid for by National Health Insurance in 12 cities in Osaka Prefecture were analyzed. The main factor affecting differences in inpatient days per insured person of all ages (hospital use) among the cities were differences in hospital use by long-stay patients aged 70 years or older, which depended not on inpatient days per patient but on the rate of hospital admission. The main factor affecting change in mean hospital use from May 1985 to May 1988 seemed to be an increase in hospital use by long-stay patients 70 years of age or older, which did not depend on increases in the rate of hospital admission, but did depend on the number of insured persons 70 years of age or older. Calculation showed that an increase of 13 long-stay patients 70 years of age or older for 10,000 insured persons 70 years of age or older per year was to have accounted for about 40% of the increase in hospital use by all patients. If the trend for increasing hospital use in Japan is to be altered, the first step might be the careful planning for this comparatively small increase in long-stay elderly patients by promotion of a non-hospital-based care system.

Age Factors↗

PubMed1993

Primary hepatic carcinoid tumor.

A case of primary carcinoid tumor arising in the liver of a 69 year old woman with no endocrine symptoms is reported. Histopathologically, the tumor was diagnosed initially as a hepatocellular carcinoma in the biopsy specimen, and was shown subsequently to be a carcinoid tumor, demonstrating diffuse positive staining with Grimelius method. Mucin stained with periodic acid-Schiff (PAS), alcian-blue, and mucicarmine, and was shown partially in the glandular structures. Immunohistochemically, most of the tumor cells stained positively for chromogranin-A, epithelial membrane antigen (EMA) and neuron specific enolase (NSE). Ultrastructural examination revealed electron-dense core granules, measuring 40-120 nm in diameter in some of the tumor cells. Intensive and careful searches pre- and post-operatively revealed no other primary source of tumor other than the liver. The patient was reported well with no symptoms 3 1/2 years after the operation. This case is considered to be a primary hepatic carcinoid tumor. The recent literature is reviewed, and the possible histogenesis of hepatic carcinoid tumor is discussed.

Aged↗

PubMed1993

Adenocarcinoma of the urachus associated with stromal osseous metaplasia.

Urachal adenocarcinoma is a rare bladder tumor, occasionally associated with calcification. We report a case of urachal adenocarcinoma with remarkable stromal osseous metaplasia and review the literature on this rare condition. This is the first complete case report in English of this uncommon entity.

Adenocarcinoma, Mucinous↗

PubMed1993

Ductus arteriosus. Advanced differentiation of smooth muscle cells demonstrated by myosin heavy chain isoform expression in rabbits.

BACKGROUND: The closure of the ductus arteriosus (DA) is one of the most striking cardiovascular events that occur at birth. It has been attributed to oxygenation and intrinsic prostaglandins. However, selective constriction of DA suggests the presence of highly specialized contractile mechanisms in DA. We previously reported that smooth muscle myosin heavy chain isoforms, SM1 and SM2, are molecular markers for smooth muscle differentiation because of their unique expression pattern during vascular development. SM1 and SM2 are generated from a single gene through developmentally regulated alternative RNA splicing; SM1 is expressed in almost all stages of differentiation of the vascular smooth muscles, but SM2 is found only after birth. METHODS AND RESULTS: Immunohistochemistry was performed to study the expression of the different types of myosin heavy chain isoforms in DA of fetal and neonatal rabbits. Electron microscopic examinations were also carried out to demonstrate ultrastructural characteristics of ductus muscles. We found that SM2 is expressed before birth in the medial layer of DA, indicating advanced differentiation of smooth muscle cells in DA. The exact location of immunoreactivity for SM2 was in the smooth muscle cell of the medial layer of DA. Immunoreactivity for SM1, however, was not different for DA and adjacent great arteries. Transmission electron microscopy demonstrated greater amounts of myofilaments in medial smooth muscles of DA than those of aorta. CONCLUSIONS: These results indicate that smooth muscles in DA are more differentiated than those in other arteries, which may be one of the cellular mechanisms responsible for the unique closure of DA at birth.

Actin Cytoskeleton↗

PubMed1993

[Hepatic resection under liver surface or perfusion cooling together with hepatoprotective agents of PGE1 and urinastatin].

The techniques and results of nine patients who underwent hepatic resections with surface and/or in situ perfusion cooling with hepatoprotective agents of PGE1 and Ulinastatin are described. Eight hepatocellular carcinomas associating chronic liver disease and one hemangioma are included in this report. Complete vascular exclusion technique with the centrifugal blood pump driven veno-venous bypass was employed on the three patients with giant liver tumors. The bypass technique with liver cooling made it possible to carry out otherwise impossible and risky resections, particularly in case with neoplastic involvement of the inferior vena cava. The other patients were subjected to segmentectomy of the right lobe under hemihepatic surface cooling or in situ hypothermic perfusion by chilled Lactate Ringer for vascular arrested right lobe. Liver tissue temperature dropped down to 19 degrees C to 26 degrees C during cooling. Postoperative physiologic changes were minimal irrespective of prolonged continuous vascular interruption of the cirrhotic liver for up to 60 min. There was no mortality and major morbidity in the present series. Liver cooling can be an useful hepatoprotective method for the cirrhotic liver in the hepatic resection with vascular occlusion.

Aged↗

PubMed1993

Dynamics of normal and injured human liver regeneration after hepatectomy as assessed on the basis of computed tomography and liver function.

We compared liver volume and function kinetics after partial hepatectomy according to extent of resection and severity of coexisting liver disease in 57 adults with uneventful postoperative courses. Liver volume and massiveness of resection, or resection rate, were estimated on computed tomography. Patients were categorized into three groups on the basis of reaction rate: small (< 30%), medium (30%-50%) and large (> 50%). The regenerative patterns of normal livers in the medium and large groups consisted of three phases: a rapid increase during the first month, some decrease in the second month and a final, slower increase. This contrasted with the pattern of injured livers with chronic hepatitis or cirrhosis, which generally showed a phase of less rapid, gradual increase. The regeneration rate (volume gain, cm3/day) during the first month was found to be proportional to resection rate in the presence or absence of liver disease. Normal livers regenerated at least twice as rapidly as injured livers in patients with comparable resection rates. Normal livers reached plateau levels within 1 to 2 mo regardless of the massiveness of resection, whereas regeneration took 3 to 5 mo in injured livers. Liver function (albumin, bilirubin) recovered concomitantly with liver volume in the medium group, whereas in the large group they generally returned to their initial values behind volume restoration, particularly in cirrhotic patients. In conclusion, human liver regeneration is strongly influenced by the massiveness of the resection and presence of coexisting liver disease. However, we found that some cirrhotic livers can regenerate, albeit more slowly and less completely, as long as the extent of hepatectomy remains within safe functional limits.

Adult↗

PubMed1993

[Adverse effect of prolonged formalin fixation on DNA ploidy in paraffin-embedded tissue].

From retrospective analysis of 174 formalin fixed, paraffin-embedded, HCC tissue samples, the possible correlation was investigated between the CV determined by FCM and the duration of formalin fixation. An adverse effect of prolonged formalin fixation on CV and fluorescence intensity in liver tissue was investigated prospectively in samples from 4 patients.

DNA, Neoplasm↗

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

The valvo-pump, an axial blood pump implanted at the heart valve position: concept and initial results.

The valvo-pump, an axial nonpulsatile blood pump implanted at the heart valve position, has been developed. The valvo-pump consists of an impeller and a motor, which are encased in a housing. An impeller with 5 vanes (22.0 mm in diameter) is used. The impeller is connected to a samarium-cobalt-rare earth magnet direct current (DC) brushless motor measuring 21.3 mm in diameter and 18.5 mm in length. Sealing is achieved by means of a ferrofluidic seal. A pump flow of 10.5 L/min was obtained at a pump differential pressure of 3.3 kPa (25 mm Hg), and a flow of 4.9 L/min was obtained at 7.0 kPa (53 mm Hg). Sealing was kept perfect against a pressure of 29.3 kPa (220 mm Hg) at 9,000 rpm.

Equipment Design↗

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↗