Biomedical subjects

H Masuda

Publications and source records attributed to H Masuda.

At least 415 records · Page 23Linked to original sources

PubMed1990

[Antitumor effect of a benzoylphenylurea derivative HO-221].

HO-221, N-[4-(5-Bromo-2-pyrimidinyloxy)-3-chlorophenyl]-N'-(2-nitrobenzoyl ) urea is a novel benzoylphenylurea derivative. We had interested in various pharmacological actions of benzoylphenylurea compounds. Therefore, many compounds were synthetized and tested in various screening systems. In the process with these tests, we found HO-221 which showed an excellent antitumor activity. The antitumor activity of HO-221 was judged from the survival time and the tumor weight of experimented tumor-bearing animals. HO-221 preparation was orally administered. The compound exhibited significant effects against various animal tumors (P388, L1210, M5076, LLC, C38, S180, W256), and especially effective against the solid tumors. HO-221 was also markedly effective to MX-1 and LX-1 implanted into nude mice. However, the effect against mouse B16 melanoma was moderate. In addition, HO-221 showed a schedule dependency and once every 4 or 7 days treatments were most effective. The antitumor activities of the compound against advanced L1210 and Lewis lung tumors were examined. Tegafur and ara-C were used as reference drug for the study. Three agents showed the antitumor activities against L1210. Against Lewis lung carcinoma, HO-221 showed both the increase of life span and the tumor growth inhibition. On the other hand, tegafur and ara-C were ineffective for the increase of life span.

Animals↗

PubMed1990

[A histopathological study on the cardiac conduction system in sudden death of unknown origin].

For the purpose of searching for the underlying mechanism of sudden death, 46 cases of non-traumatic sudden death were selected from autopsied cases during the past 8 years from 1980 to 1987 in the department of legal medicine, St. Marianna university school of medicine. These included 40 males and 6 females ranging from 30 to 60 years of age. Autopsy revealed the existence of cardiac abnormalities in 41 cases (89.1%). Among them, acute myocardial infarction was found in 23 cases (56.1%) and there were 16 cases (39.0%) diagnosed as acute cardiac failure because of the absence of organic abnormality in the heart. Out of the latter cases having undefined etiology of sudden death, 10 cases were selected and histopathological study on the cardiac conduction system was performed by Lev's method. Fatty infiltration in the sinus node, in the atrio-ventricular node and bundle of His was observed in 5 cases, severe stenosis of atrio-ventricular nodal artery in 2 cases and subendocardial hemorrhage of left bundle branch in 1 case. In the remaining case, no pathological abnormality was observed. These results suggest that the organic lesion of the cardiac conduction system could underlies the clinically undefined cause of sudden death.

Adolescent↗

PubMed1990

[Pure aortic valve regurgitation due to congenital bicuspid valve--analysis of 7 cases and a report of 2 rare cases].

The congenital bicuspid aortic valves usually become stenotic with severe calcification or regurgitant due to infective endocarditis (IE). However, pure aortic valve regurgitation without calcification or IE may be occurred. We report seven these cases out of 30 bicuspid valved patients who underwent aortic valve replacements. Pathological findings of these resected valves revealed neither calcium deposit nor findings of infection, but commonly showed myxoid degeneration. They were operated on at the mean age of 39, while those with calcified bicuspid aortic valves had an average age of 56. Two rare cases in whom an anomalous fibrous band on the larger cusp attached to the aortic wall were also reported.

Adult↗

PubMed1990

Clinical evaluation of the response to surgical treatment of Graves' disease.

Included in this study are 513 patients with Graves' disease who underwent thyroidectomy between 1970 and 1983. The patients were divided into three groups by dividing the period in which the surgical procedures were done. The weight of the remnant of the thyroid gland and the incidence of surgical complications were collated for the patients in each group studied. Postoperative function of the thyroid gland was evaluated clinically and biochemically and compared with the remnant weight and total weight of the thyroid gland. The remnant weight was greatest in the first period and least in the third period. There were no differences between the frequencies of postoperative complications among the three groups in site of a remarkable decrease of the remnant weight in the third period. Remission of hyperthyroidism, including those with a latent hypothyroid state, was most frequently observed in the group in which the remnant weight was from 4 to less than 8 grams. These results indicate that the remnant weight appears to be one of the most crucial factors influencing the postoperative outcome; it thus seems appropriate to leave only small remnants of the thyroid gland (4 to less than 8 grams) at thyroidectomy. In our hands, surgical treatment is an effective and safe procedure for Graves' disease, although the precise mechanism for the remission induced by this procedure has not been elucidated.

Graves Disease↗

PubMed1990

[Clinical evaluation of extended neck differentiated thyroid carcinoma].

In some patients with advanced differentiated thyroid carcinoma, an upper mediastinal dissection is recommended. Both 17 primary and 6 non-primary patients who had undergone an upper mediastinal dissection in Shinshu University Hospital, from 1984 to 1987, were surveyed. We also studied 198 patients who had been performed a modified radical neck dissection from 1984 to 1986. In the 17 primary cases, 6 (35%) had positive nodes in the upper mediastinum (M group), and 11 (65%) negative (NM group). And we analysed these two groups. In addition, 5 non-primary cases and 198 patients were analyzed in terms of the nodal metastatic status of the tumor-free side. From these results, we conclude the indication of mediastinal dissection for thyroid carcinoma as follows: (1) positive lymph node is suspected in the upper mediastinum by the study of CT or 201thallium scintigram. (2) nodal metastases are suspected in the deep cervical location of the tumor-free side. (3) a male patient whose age is younger than 50, and tumor is located in the left lobe and its size is larger than 3.0 cm.

Carcinoma↗

PubMed1990

[A case report of abdominal aortic aneurysm complicated by left-sided inferior vena cava].

Left-sided inferior vena cava (IVC) was identified preoperatively in the case of abdominal aortic aneurysm. At operation, the left-sided IVC and bilateral common iliac veins were severely pressed by the huge aneurysm, and the walls of these vessels were thin and fragile at the site adhered to the aneurysm. Careful dissection around the common iliac arteries resulted in a successful operation. Without an awareness of such anomaly, accidental injury of IVC and the common iliac veins may occur. Preoperative diagnosis and accurate information from echography, CT scan, and venography of the vena cava are recommended in such rare cases.

Aged↗

PubMed1989

Isolation and characterization of a new 36-kDa microfibril-associated glycoprotein from porcine aorta.

A new connective tissue protein of 36 kDa has been purified from porcine aorta. The biochemical and immunological properties of the protein are distinct from those of microfibril-associated proteins reported previously such as lysyl oxidase, 31-kDa microfibril-associated glycoprotein, and fibrillin. It could bind to concanavalin A-Sepharose and gelatin-Sepharose. The protein contained the sequence Arg-Gly-Asp-Ala in the amino-terminal region, which is the site for the association with cell and extracellular matrix. Using specific antibody raised to the protein, we demonstrated its restricted localization in aorta adventitia. Immunoelectron microscopy specified its location to a class of extracellular structural elements described as elastin-microfibrils.

Amino Acid Sequence↗

PubMed1989

[Carcinoid tumor of the liver].

Multiple primary hepatic carcinoid tumours of the liver was a chance finding at autopsy of an 81-year-old woman. There had been no signs of this or any other paraneoplastic syndrome in life. The tumour had a characteristic solid-alveolar structure (type A of Soga) with only a few atypical cells. Neuron-specific enolase and chromogranin were demonstrated immunohistologically in almost all tumour cells, but S-100 protein, human choriogonadotropin and serotonin in only a few. Peptides and alpha-fetoprotein, however, could not be demonstrated in the tumours. Electronmicroscopy revealed secretory granules of variable size and density in the cytoplasm of the tumour cells.

Aged↗

PubMed1989

Incidence of chromosomal anomalies in early bovine embryos derived from in vitro fertilization.

The incidence of chromosomal anomalies in early bovine embryos derived from follicular oocytes fertilized in vitro using sperm separated by Percoll density gradient centrifugation was investigated. Overall, chromosomal anomalies were observed in 13.7% (138/1005) of embryos. There were 14 haploids (1.4%), 2 hypodiploids (0.2%), 6 hyperdiploids (0.6%), 101 triploids (10.0%), 12 tetraploids (1.2%), 2 diploid/triploid mosaics (0.2%), and 1 diploid/tetraploid mosaic (0.1%). The frequency of triploidy was caused mainly by polyspermy. There was a significant difference in the frequency of embryos with abnormal chromosomes between the two bulls used (P less than 0.005), but Percoll centrifugation did not affect the observed incidence of anomalies. The frequency of chromosomal anomalies in embryos at each stage increased with delay or arrest of development. These results suggest that the incidence of chromosomal anomalies depended on the conditions of in vitro fertilization and the arrest of development.

Aneuploidy↗

PubMed1989

Physiological changes during temporary occlusion of the superior vena cava in cynomolgus monkeys.

To evaluate the physiological changes that occur after temporary occlusion of the superior vena cava, we clamped the vena cava for one hour in 6 cynomolgus monkeys, monkeys with a venous system most resembling that of humans. The data from arterial blood gas analysis, ie, pH, arterial oxygen tension, arterial carbon dioxide tension, and HCO3-, were within normal limits during and after occlusion of the superior vena cava. Intracranial pressure was 8.6 +/- 0.8 mm Hg (mean +/- standard error) before occlusion and rose to 22.1 +/- 2.2 mm Hg during clamping. It decreased significantly to 17.7 +/- 1.9 mm Hg just before removal of the clamp and recovered to 8.6 +/- 0.9 mm Hg after the clamp was removed. Regional cerebral blood flow was 45 +/- 9 mL/min/100 g before clamping and decreased to 37 +/- 3 mL/min/100 g during clamping. It recovered to 47 +/- 5 mL/min/100 g after removal of the clamp. Cerebral perfusion pressure was within the margin of safety during clamping. Histological findings in the brain showed the effect of congestion in 1 monkey, but the change was slight. The electroencephalogram and electrocardiogram showed no abnormalities in this experiment. In conclusion, one-hour clamping of the superior vena cava with the azygos vein ligated was safe in 6 cynomolgus monkeys. We believe that in the clinical setting, one-hour occlusion of the superior vena cava would result in findings similar to those in this study, unless particular complications, such as arteriosclerosis or a cerebrovascular disorder, exist.

Animals↗

PubMed1989

Caloric restriction perturbs the pituitary-ovarian axis and inhibits mouse mammary tumor virus production in a high-spontaneous-mammary-tumor-incidence mouse strain (C3H/SHN).

Dietary restriction (DR) retards aging and extends maximum life span. It is also known to decrease the incidence of hormone-dependent tumors. In the present investigation, we focussed primarily on the influence of DR on the pituitary-ovarian axis, and subsequently on gene expression of the mouse mammary tumor virus. F1 females from the mating of SHN female and C3H male mice were used in this study, since these hybrids display a very high incidence of mouse mammary tumors. The mice weaned at 3 weeks were raised on either a calorically-restricted diet (DR: 50 kcal/week; N = 5) or on a control diet (C: 95 kcal/week N = 5) for 5 weeks. Three C57BL/6J Jcl ad libitum-fed female mice, 8 weeks of age, were used as reference animals since this strain has a very low incidence of mammary tumors. The mean cellular contents of prolactin (PRL) and growth hormone (GH) in the pituitary, as determined by immunohistochemistry, were found to be reduced in mice raised on the DR diet. The decrease in the mean cellular content of PRL (50% of the mean control value) was accompanied by a decrease in the number of lactotrophs (17% of the mean value of control diet mice). However, the decrease in cellular content of GH (53% of the mean control value) was not accompanied by a decrease in the number of somatotrophs (no. of somatotrophs in DR = 103% of mean control value). Histologically, ovaries from DR mice showed many growing and atretic follicles, with few corpora lutea. In contrast, both control-diet and reference (C57BL/6J Jcl) mice showed two or three corpora lutea per ovarian section. In accordance with this finding, DR mice had not established stable estrus cycles by 8 weeks of age, in contrast to both control-diet and reference mice. Since caloric restriction has been shown to decrease mammary tumor virus (MMTV) gene expression, MMTV production was investigated by electron microscopy to confirm the validity of our experimental conditions. In DR or reference C57BL/6J Jcl mice, MMTV particles were rarely found in the mammary gland samples, but were always found in samples from control mice. The development of mammary glands, as indicated by the number of villi or the development of the rough endoplasmic reticulum, was delayed in DR mice. Thus, it was concluded that caloric restriction decreases the number of lactrotrophs, inhibits ovulation and delays mammary gland development. This immature status is considered to be due to perturbations in the pituitary-ovarian axis by caloric restriction.

Animals↗

PubMed1989

Change of glycosaminoglycan in pus of patients with purulent pleurisy.

The glycosaminoglycan content in pus from patients with purulent pleurisy was studied. The uronic acid content rose in the first 4 hospital days, continued at a high level during hospital days 5-8, and then fell to a low level after 9 hospital days. Four glycosaminoglycans were isolated from the preparation; they were identified as hyaluronic acid, chondroitin 4-sulfate, chondroitin 6-sulfate, and dermatan sulfate. Hyaluronic acid was the main component and its relative proportion increased with increasing hospital days. The relative proportions of chondroitin 4-sulfate and chondroitin 6-sulfate were low during the first 4 day and during Days 10-21, whereas they were high during Days 5-9. The proportion of dermatan sulfate was high during the early hospital days, and thereafter decreased with increasing hospital days.

Carbohydrate Metabolism↗

PubMed1989

Composition of glycosaminoglycans in human pancreatic cancer.

Five glycosaminoglycans were isolated from tryptic digestion of both cancerous and normal tissues of the human pancreas and were assayed by determining the carbohydrate content of materials. Separation of these five polymers was achieved by Dowex 1-X2 column chromatography and fractionation with Benedict's solution. They were identified as hyaluronic acid, heparan sulfate, dermatan sulfate, chondroitin-4-sulfate, and chondroitin-6-sulfate, respectively. The total amount of glycosaminoglycans in cancer tissue increased in comparison to the controls. The increase in tissue content of glycosaminoglycans was accompanied by increases in chondroitin-4-sulfate and chondroitin-6-sulfate levels.

Aged↗

PubMed1989

Longevity of expanded polytetrafluoroethylene grafts for superior vena cava.

We previously reported that the expanded polytetrafluoroethylene (ePTFE) graft for superior vena cava (SVC) substitution presents the problems of flexion and kinking when the graft is long. We therefore replaced the SVC of dogs with two types of prosthetic substitutes, ePTFE (Gore-Tex) and spiral-supported ePTFE (Im/praflex), and evaluated the long-term patency of the prosthetic substitutes. Total replacement of the SVC was performed in 9 adult mongrel dogs. The substitutes were ePTFE and spiral-supported ePTFE in 5 and 4 dogs, respectively. The animals were killed about 3 years after replacement of the SVC, and the harvested specimens were histologically examined by light microscopy and scanning electron microscopy. Evaluation of ePTFE revealed late occlusion in 1 of 5 dogs. The spiral-supported ePTFE showed patency in all dogs. In the group with ePTFE grafts, light microscopic examination revealed abnormalities of endothelial cells, granulation, and necrosis. There was no hyperplasia of the subendothelial connective tissue near the center. In the animals with spiral-supported ePTFE grafts, the subendothelial connective tissue showed favorable growth even in the center of the reconstructed site. There was no granulation in the spiral-supported ePTFE group. Scanning electron microscopic examination in the ePTFE group showed that endothelial cells were spindle-shaped and had an irregular surface. The spiral-supported ePTFE group showed an almost regular form of endothelial cells and no abnormalities except for the slightly spindled shape in the center. Therefore, we recommend that spiral-supported ePTFE should be used as an SVC substitute in clinical situations.

Animals↗

PubMed1989

Cell wall proteins from sugar beet cells in suspension culture.

Several proteins were extracted from the purified cell walls of suspension-cultured sugar beet cells with 0.5% EDTA (pH 6.8) after prior extraction of the walls with 0.5% deoxycholate and then with 2 molar NaCl. Two abundant proteins (P-I and P-II protein) were separately purified to homogeneity by procedures that included fractionation with ammonium sulfate, column chromatography on DEAE-cellulose and butyl Toyopearl, and preparative polyacrylamide electrophoresis. P-I exists as a dimer of identical subunits, and P-II is composed of four different subunits. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that quite different polypeptides are present in the culture medium and in the NaCl and EDTA extracts of the wall.

Journal Article↗

PubMed1989

Endocardium of the left ventricle in volume-loaded canine heart. A histological and ultrastructural study.

To investigate the effects of volume loading of the heart, the endocardium was studied histologically and ultrastructurally. Thirteen adult female beagle dogs were used. An arterio-venous shunt was constructed between the right common carotid artery and the right external jugular vein in nine animals to induce a volume load. Four animals were used as controls. All were kept for 6-12 months. Heart weight, relative heart weight (heart weight/body weight), cardiac output index, stroke volume index and volumes of both ventricles in the experimental animals were significantly larger than in the controls. Shunted blood volume was significantly correlated with heart weight. The endocardium of the left ventricle in the experimental animals showed elastofibrosis and was significantly thicker than in the controls. In 5 hearts, it was more than 20 microns thick and its endothelial cells showed many long microvilli with a very thick basement membrane (1.5-2.0 microns). The thickness of the endocardium was significantly correlated with the heart weight, relative heart weight and cardiac output index, within 1%, 5% and 5% risk, respectively. These endocardial changes were thought to be induced by hemodynamic changes in the left ventricle of the volume-loaded heart, probably being correlated with changes in cardiac function and morphology.

Animals↗

PubMed1989

A small aneurysmal bone cyst restricted to the cortical bone of the femur resembling so-called subperiosteal giant cell tumor or subperiosteal osteoclasia.

We report a 16-year-old Japanese girl with a cystic lesion restricted to the cortical bone under the periosteum of the diaphysis of the left femur. Roentgenograms showed a long, oval translucent lesion in frontal view and an eccentric erosive lesion in lateral view. Computed tomography showed a distinct intracortical lesion. The lesion, which was excised en bloc, measured 3 x 2 x 2 cm. The outer layer of the cortical bone was eroded eccentrically. From the margin of the eroded bone, thin fragile bony tissue and preserved periosteum extended like the roof of a dome. Multicystic structures, filled with blood, were lined with fibrous granulation and occasional giant cells. Histologically, this lesion falls within the category of aneurysmal bone cyst. However this case is of a rare type, since the lesion was relatively small, and showed a very specific intracortical location, in marked contrast to typical aneurysmal bone cyst. Additionally, this lesion is similar to so-called subperiosteal giant cell tumor or subperiosteal osteoclasia described in the literature.

Adolescent↗

PubMed1989

Insulin secretion in childhood obesity.

In 132 severely obese children (72 boys and 60 girls) who underwent institutional therapy, oral glucose tolerance tests were carried out on admission, and these children were divided into groups with normal and high insulin levels, in terms of the sigma IRI values obtained, on the basis of the reference value + 2SD calculated by Maruhama et al. From these children, those who had diabetes mellitus (DM) and those in whom DM was suspected were distinguished according to the diagnostic criteria of USPHS (Drash et al). The insulin levels were normal in 58 children and high in 64. Ten children were found to have DM, and 19 were suspected to have DM. Metabolism of the glucose load occurred at both normal and high insulin levels in some children. There was also a group of children in whom glucose metabolism was incomplete at high insulin levels and a group of children in whom glucose metabolism was not possible even at high insulin levels, showing an obvious DM reaction. These findings suggest that there is a difference in the sensitivity of the insulin receptors in these children. Age, severe obesity and a family history of DM were considered to be risk factors for DM. Although there was a moderate, positive correlation between sigma IRI and the obesity index and between sigma IRI and age, it seems that the level of insulin secretion varies considerably in obese children.

Adolescent↗