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Biomedical subjects

H Hamada

Publications and source records attributed to H Hamada.

At least 397 records · Page 22Linked to original sources
PubMed1991

Flow cytometric analysis of the nuclear DNA content of hepatoblastoma.

The nuclear DNA content of 15 hepatoblastoma cases was determined in paraffin-embedded tissues by flow cytometry. The DNA index (DI) was calculated, and the ploidy pattern of nuclear DNA was estimated. The correlation between the ploidy pattern and clinicopathologic findings was studied, and the prognostic significance of the ploidy pattern was investigated. An aneuploid pattern was seen in 50% of the lesions with histologic embryonal and anaplastic types. It was not seen in the fetal type. In the tumors with combined epithelial components, the fetal-type component had a diploid pattern in all five cases. The embryonal-type component was associated with aneuploidy in two of five cases. In aneuploid tumors, vascular invasion (tumor emboli in the vessels) was observed more frequently. The prognosis of the patients with an aneuploid tumor was significantly poorer. These results indicate that nuclear DNA ploidy pattern analysis might be useful in investigating the prognosis of hepatoblastoma.

Carcinoma, Hepatocellular↗
PubMed1991

Stringent integrity requirements for both trans-activation and DNA-binding in a trans-activator, Oct3.

POU-specific and POU-homeo domains of Oct3 were produced in Echerichia coli for characterization of DNA binding to the octamer sequence. POU domain protein including A, B and H domains could bind to the octamer sequence efficiently and specifically, and DNase I footprint analysis gave an indistinguishable protection pattern between recombinant POU protein of Oct3 and native Oct3 from undifferentiated P19 cells. Truncated mutants, which contained B-specific and H domains or the H domain only, showed no binding activity, indicating that both of POU-specific and POU-homeo domains are essential for binding activity to octamer sequence. Furthermore, a 6 amino acid deletion from the N-terminal region of the A-specific domain is enough to destroy the binding activity. As for trans-activation, the N-terminal region is essential and sufficient. Deletion of the N-terminal proline-rich region rapidly eliminated trans-activating activity. These data strongly indicate the stringent integrity requirements for both trans-activation and DNA-binding domains in Oct3.

Amino Acid Sequence↗
PubMed1991

Prognostic significance of argyrophilic nucleolar organizer staining in soft-tissue sarcomas.

The utility of argyrophilic stain for nucleolar organizer region (AgNOR) for estimating proliferative activity and prognosis of soft-tissue sarcomas (STS) was examined. Formalin-fixed and paraffin-embedded sections of 38 cases with STS were used; the reaction product of AgNOR stain was observed as dots mainly in the nucleoli. The mean number of AgNOR dots per nucleus of tumor cells was calculated in 200 cells (AgNOR count). The AgNOR count, ranging from 1.4 to 16.1 (mean, 7.5), showed a good correlation with cellularity (r = 0.483, p less than 0.003) and histologic grade (r = 0.626, p less than 0.00005), but less shown with mitotic counts (r = 0.350, p less than 0.04). The prognosis of cases with AgNOR low-count group (5-year survival rate was 74.6%) was much better than those in high count group (33.3%) (p less than 0.0005). The AgNOR count correlated well with reactivity of tumor cells for Ki-67 staining, which was available only in freshly prepared sections. These findings suggested that the AgNOR staining is a simple and useful method for estimating tumor-cell proliferation and prognosis of patients with STS.

Adolescent↗
PubMed1991

The oct3 gene, a gene for an embryonic transcription factor, is controlled by a retinoic acid repressible enhancer.

Oct3 is an embryonic octamer-binding transcription factor, whose expression is rapidly repressed by retinoic acid (RA). In this report, we have determined the transcriptional control region of the oct3 gene and studied the mechanism of the RA-mediated repression. The chromosomal oct3 gene consists of five exons. Three subdomains of the POU region and transactivating domain are located in separate exons. Transcription initiates at multiple sites in the GC-rich region lacking a typical TATA box. The upstream 2 kb region can confer the cell type-specific expression and RA-mediated repression. Analysis of the upstream region by deletion mutagenesis locates a cis element (RARE1) which functions as a stem cell-specific, yet RA-repressible, enhancer. Footprint and gel-retardation assays show that RARE1 is composed of two domains, each of which is recognized by distinct factors. Microinjection of oct3-lacZ constructs into fertilized eggs indicates that RARE1 can function in early embryos. We suggest that RARE1 is a critical cis element for oct3 gene expression in embryonic stem cells and for the RA-mediated repression.

Amino Acid Sequence↗
PubMed1991

A case of trisomy 21 with holoprosencephaly: the fifth case.

A case of trisomy 21 with holoprosencephaly, the fifth case in the literature, is described. The patient also had extracephalic malformations frequently associated with Down syndrome. The possibility of a causal relationship between trisomy 21 and holoprosencephaly is discussed.

Abnormalities, Multiple↗
PubMed1991

The effect of a cost sharing provision in Japan.

This study evaluated the effect of a 10% cost sharing provision, introduced in October 1984, on demand for medical services. We analysed the data of 1701 health insurance societies, all of which joined the National Federation of Health Insurance Societies between 1983 and 1985. The case rate (per 1000 persons) and the number of serviced days (per case) were analysed as indicators of demand for inpatient, outpatient and dental medical services. The case rate was considered to be an indicator of the patient's behaviour, while the number of serviced days was influenced by the doctor's behaviour. Multiple linear regression analysis was used with each indicator to isolate the effect of the cost sharing provision, adjusted for other variables which influenced demand for medical services. The case rate was reduced significantly in all medical services. This means that a patient was discouraged from using a medical facility by the cost sharing provision. There was little difference among medical services. The number of serviced days was also reduced significantly in all medical services. There was a large difference among medical services. The effect on outpatient service was much greater than that on any other service.

Cost Sharing↗
PubMed1991

Comparative effects of halothane, isoflurane, and sevoflurane on the liver with hepatic artery ligation in the beagle.

Recently, there has been increasing interest in the alterations in splanchnic and hepatic circulation and preservation of hepatic oxygenation and function during anesthesia and surgery. However, the effects of volatile anesthetics under a condition of marginal hepatic oxygen supply are not well understood. Using a crossover design, we therefore studied the effects of equianesthetic concentrations (1.5 MAC) of halothane, isoflurane, and sevoflurane on hepatic oxygenation and function in nine beagles in which the hepatic artery had been ligated. Portal blood flow was measured by an electro-magnetic flow meter. Hepatic function was assessed by indocyanine green elimination kinetics. While cardiac output and mean arterial pressure were greater during halothane anesthesia than during isoflurane and sevoflurane anesthesia, portal blood flow and hepatic oxygen supply were significantly less during halothane and sevoflurane anesthesia than during isoflurane anesthesia. With regard to hepatic oxygen uptake, there was a significant difference between halothane (2.7 +/- 1.2 ml.min-1 x 100 g-1) and sevoflurane (3.7 +/- 2.0 ml.min-1 x 100 g-1; P less than 0.05). Consequently, the hepatic oxygen supply/uptake ratio and the hemoglobin oxygen saturation and oxygen partial pressure in hepatic venous blood during sevoflurane anesthesia were significantly less than they were with the other anesthetics. Indocyanine green clearance was better preserved during sevoflurane anesthesia (39.7 +/- 12.0 ml.min-1) than during halothane anesthesia (30.9 +/- 8.4 ml.min-1; P less than 0.05). We conclude that sevoflurane is accompanied by a smaller oxygen supply/uptake ratio than is halothane and isoflurane, while it preserves hepatic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthetics↗
PubMed1991

[The effect of sharing medical costs for the aged 70 or more on the financial balance of the health insurance society].

The rapid increase of the proportion of older persons in society has made the problem of medical costs more important. Although medical cost-sharing for those aged 70 or more is decided by their medical costs and by the current proportion of such persons in the Society, it is not constant throughout the Society. The study evaluated the contribution ratio of medical cost-sharing for those aged 70 or more to the financial balance of the Society. In addition, characteristics of the Society associated with medical cost-sharing for those aged 70 or more were analyzed. The results are as follows. 1) Medical cost-sharing for those aged 70 or more was the greatest factor in the financial balance of the Society with a contribution ratio of as much as 55.2%. 2) Multiple regression analysis disclosed that dependent ratio, the average monthly salary, the area, the rate of those aged 70 or more and the average age of the Society members are significant in medical cost-sharing for those aged 70 or more. 3) Dependent ratio and the average monthly salary are the most important characteristics among those associated with medical cost-sharing for those aged 70 or more. A higher dependent ratio and a lower average monthly salary are related to higher cost-sharing. This is also related to geographic factors as cost-sharing in western Japan is higher than in eastern Japan. The lower rate of those aged 70 or more and the higher average age of the Society members are related to the higher cost-sharing.

Aged↗
PubMed1991

Microscopic observations of skin and lymphoid organs in the hairless dog derived from the Mexican hairless.

The skin and lymphoid organs of Mexican hairless dogs and their hairless offspring were examined histologically. The hairless dogs lacked most hairs except for sparse hairs on the head, tail and feet. The skin of newborn pups consisted of a thick epidermis with epidermal ingrowths forming the rudiments of hair follicles. In older dogs more than 2 months of age, however, the epidermis was thin and the ingrowths were few. Neither hair follicles nor skin glands were present. The hairy skin of the head and tail had hair follicles with sebaceous glands. Regarding the lymphoid organs, the newborn pups possessed a thymus like haired pups. But in the older dogs more than 2 months of age, the thymus was atrophied and the lymphocyte population was too sparse to demarcate the cortex and the medulla. Lymphocyte accumulation in older dogs was also poor in the spleen and mesenteric lymph nodes. The present findings indicate that the hairlessness of the Mexican hairless dogs and their descendants is accompanied by early atrophy of the thymus after birth, and is followed by poor accumulation of lymphocytes in the thymus-dependent area of the spleen and the mesenteric lymph nodes. The defect of the thymus in the hairless dog seems to be different from that in athymic nude mice and rats. Further studies are needed to elucidate the immunological response and function in hairless dogs.

Animals↗
PubMed1991

[An epidemiological study on low back pain and occupational risk factors among clinical nurses].

Recently medical services and nursing system are being reformed due to high medical costs and shortage of clinical nurses. The shortage of clinical nurses influences not only their working conditions but also their own health problems. In European countries and the United States, low back pain (LBP) has been reported to be one of the most common and costly health problems among clinical nurses. To estimate the occupational risk factors of LBP among nurses, a questionnaire survey of LBP and occupational risk factors was carried out in 1987 on 947 clinical nurses and as well as on 300 female clerical workers of three local governments. First, to examine the prevalence and the magnitude of the problem, we analyzed several kinds of prevalence rates of LBP and its characteristics among nurses and clerical workers. Second, a case-control study was conducted to investigate the relationship between LBP and occupational risk factors. In analyzing occupational risk factors of LBP, odds ratios, age adjusted odds ratios and 95% confidence intervals were computed. Finally, to estimate simultaneously the effect of multiple risk factors of LBP and to confirm univariate age adjusted odds ratio analyses, several multivariate analyses were performed. Point, period (a month), and lifetime prevalence rates of LBP and prevalence rate of severe LBP among clinical nurses were significantly higher than those of clerical workers (p less than 0.05-0.001, respectively). Demographic and occupational items, such as being an assistant nurse (as opposed to a registered nurse), and working in certain departments (internal medicine, orthopedic surgery, neurosurgery, psychiatry, tuberculosis ward) showed significantly higher odds ratios for LBP (p less than 0.05-0.001, for all). Many items pertaining to working conditions connected with shift work, hospitalized conditions of patients, taking breaks and holidays, working postures, weight of patients and equipment lifting and moving, working environments and so on had significantly elevated age adjusted odds ratios (p less than 0.05-0.001, for all). Intensity of work loads estimated subjectively such as 'caring for patients who are in bed', 'supporting patients when transporting and bathing them', 'preparing drugs and injections, and treating', 'observing and monitoring patients' conditions', 'instructing and explaining procedure to patients and their family' and so on also had significantly elevated age adjusted odds ratios (p less than 0.05-0.001, for all). Moreover, many items on the problems connected with working life and interpersonal relationships showed significantly higher age adjusted odds ratios (p less than 0.05-0.001). In multivariate analyses, independent variables which made a significant contribution to the model were similar to the items which had significantly elevated age adjusted odds ratios.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1991

Elevated expression of P-glycoprotein in kidney and urinary bladder cancers.

A monoclonal antibody, MRK16, recognizing specifically an epitope of P-glycoprotein (P-GP), a highly active efflux transporter of chemotherapeutic agents, was used to determine the degree of expression of P-GP in the normal human kidney and urinary bladder, and in kidney and urinary bladder cancers. P-glycoprotein was localized in the microvilli of the epithelial cells of the proximal renal tubules by immunoelectron microscopy, and detected immunohistochemically in 6 of 20 untreated kidney cancers and 11 of 31 untreated urinary bladder cancers. Some of the cancerous tissues were further examined with regard to P-GP expression by immunoprecipitation. In urinary bladder cancers, the degree of P-GP expression seemed to be somewhat correlated with tumor grading. These results indicate that our method to detect the degree of expression of P-GP by MRK16 may be applicable for the diagnosis of clinical multidrug resistant urinary cancers.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Complement activation pathways associated with islet cell surface antibody (ICSA) derived from child patients with insulin-dependent diabetes mellitus (IDDM).

We studied the pathways of complement activation associated with the islet cell surface antibody (ICSA) obtained from sera of 7 patients (age less than 15 years) with insulin dependent diabetes mellitus (IDDM). The target cells were 51CR labelled rat islet cells and the complement source was human AB serum. Complement-dependent antibody mediated cytotoxicity (CAMC activity) was obtained using the percentage of cytotoxicity. CAMC activity of untreated sera was significantly inhibited by treating with EGTA or EDTA (p less than 0.001). The CAMC activity of EDTA-treated sera was significantly lower than that of EGTA-treated sera (p less than 0.001). In the inactivated human AB serum, it was lower than that of EGTA-treated sera (p less than 0.05), but not different from that of EDTA-treated sera. These results show that the complement activation associated with ICSA in patients occurred not only via the classical pathway but also via the alternative pathway.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1991

[Significance of umbilical plasma concentrations of catecholamines and their metabolites in patients with term vaginal deliveries].

In an attempt to further clarify the physiological significance of Catecholamine (CA) s in the feto-placental unit, umbilical plasma concentrations of CAs and CA metabolites, 3-methoxy-4-hydroxy-phenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured in cases of full-term vaginal deliveries by HPLC-ECD. Results were as follows. 1. Norepinephrine (NE) and epinephrine (E) levels were significantly higher in arterial than in venous plasma, but no significant arterio-venous differences were found with dopamine (DA) concentrations. 2. High concentrations of MHPG, DOPAC and HVA were demonstrated in both arterial and venous plasma. 3. DOPAC and HVA levels were significantly higher in arterial than in venous plasma, but no significant arterio-venous differences were noted with MHPG. 4. A significant positive linear relations hip was demonstrated between arterial levels of NE and MHPG as well as DA and DOPAC, DA and HVA. 5. Arterial plasma MHPG levels were correlated significantly with arterial plasma pH and pO2. These results suggest that, in the feto-placental unit, NE, E and DA turnover is increased at term vaginal deliveries, and NE and E secretion sensitively responds to fetal respiratory and metabolic states. In addition, it is suggested that the mechanism which controls the DA turnover is different from that of NE and E.

3,4-Dihydroxyphenylacetic Acid↗