Biomedical subjects
Publications and source records attributed to Y Hamada.
A 53-year-old woman presented with symptoms of dyspnea on exertion and edema of lower extremities. Chronic cardiac tamponade caused by the rupture of the right atrial wall was diagnosed by two-dimensional contrast echocardiography. Autopsy findings revealed primary cardiac hemangiopericytoma.
A 54-year-old female presented with apparent isolated hypothalamic histiocytosis X associated with diabetes insipidus and Korsakoff's syndrome. Computed tomographic and magnetic resonance imaging demonstrated a single hypothalamic mass. A craniotomy for biopsy found granulation tissue of unknown cause. Further investigation discovered genital bleeding before admission. Biopsy of the cervix uteri revealed histiocytosis X. Further studies showed the disease was restricted to the hypothalamus and the endometrium of the cervix uteri. Low-dose irradiation led to partial regression of the hypothalamic mass and improvement of Korsakoff's syndrome. Even when a diagnosis of isolated hypothalamic histiocytosis X is confirmed, the possibility of another histiocytosis X lesion in an unexpected region must be considered.
Increased sorbitol levels have been demonstrated in tissues of diabetic patients. Although tissue sorbitol levels correlate with plasma glucose levels, a large variability in sorbitol levels has been observed among diabetic patients with similar plasma glucose levels. This variability in tissue sorbitol levels may be due to differences in the activity of aldose reductase, the enzyme that converts glucose to sorbitol. In this study, we isolated aldose reductase from erythrocytes of 31 diabetic patients and 6 nondiabetic control subjects, measured its activity, and compared it to simultaneously measured erythrocyte sorbitol levels. The activity of erythrocyte aldose reductase was increased in diabetic patients compared with control subjects (28.1 +/- 1.4 vs. 22.4 +/- 1.7 nmol.min-1.g-1 Hb, P less than 0.05), but there was an approximately threefold variation in aldose reductase activity among diabetic patients. Erythrocyte aldose reductase activity and fasting plasma glucose levels significantly correlated with the erythrocyte sorbitol level in all individuals (r = 0.48, P less than 0.005 and r = 0.63, P less than 0.005, respectively). The sorbitol level was higher in patients with high aldose reductase activity than in those who had low enzyme activity for any given level of glycemia. The sorbitol production rate calculated from Km and Vmax values showed a better correlation with the erythrocyte sorbitol level (r = 0.80, P less than 0.005), and there was also a good correlation between the erythrocyte sorbitol level and the product of aldose reductase activity by plasma glucose level (r = 0.70, P less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
M-SHRSP rats appear to be a useful animal model for studying juvenile human malignant hypertension. Using M-SHRSP, the present study was conducted. Drugs selected for use were captopril, SQ 29,852 and hydralazine hydrochloride. The rats were also fed a 33% fish meal diet. When given separately, all three drugs were shown to be anti-hypertensive. However, using the fish meal diet combined with hydralazine was more effective than were any of the drugs given separately, while the effect of hydralazine combined with captopril or SQ 29,852 was even greater than that of the combined fish meal diet and hydralazine treatment. Some rats treated with captopril or SQ 29,852 separately were resistant to treatment, however even for these rats life spans were significantly prolonged and hypertensive vascular lesion incidence rates were drastically lowered. It was also found that even such vascular lesions as angionecrosis seemed to disappear with captopril or SQ 29,852 treatment.
A new microsurgical device for delicate brain retraction is described. The device, a micromanipulator with a holder for a brain spatula fixed at the end of a self-retaining retractor arm, allows smooth, steady, fine displacement of the retractor tip ("minimal sliding retraction"), operated by the surgeon's two fingers. This has proved to be a useful and safe method of retraction for critical brain structures such as blood vessels, cranial nerves and aneurysm domes in deep microsurgical fields.
Previously, we describe a unique binding site for the Fc region of IgG in human intestinal goblet cells, but regulation of the intestinal IgG Fc binding site (Fc gamma IBS) has not been clarified. In this work, we examined the effects of tumour necrosis-alpha (TNF-alpha) and interferon gamma (IFN-gamma) on expression of the Fc gamma IBS in HT29-N2 colonic cancer cells, which differentiate readily into goblet cells containing the binding site when grown in galactose-containing medium. Expression of the site was monitored immunocytochemically and by ELISA on homogenates of the cells. TNF-alpha in doses of 0.1-100 ng/ml caused a reduction in expression of the Fc gamma IBS and the proportion of cells positive for mucin (as demonstrated by Alcian blue stain), without affecting the viability of the cells. The effects of TNF-alpha on the FC gamma IBS and mucin production could not be attributed to a decreased proliferative rate of the cells, as the cells' incorporation of 5-bromo-2'-deoxyuridine was unaffected. By contrast with TNF-alpha, IFN-gamma (i) did not affect the proportion of cells expressing the Fc gamma IBS, (ii) decreased the viability of the cells, and (iii) increased cell proliferation. Additional evidence of specificity of the TNF-alpha effect on the Fc gamma IBS was that TNF-alpha did not affect expression of the polymeric immunoglobulin receptor (secretory component), whereas IFN-gamma increased it. We conclude that TNF-alpha may suppress expression of the Fc gamma IBS by colonocytes and oppose differentiation of the cells towards mucin-producing cells.
The formation of adhesions around the lacerated flexor tendons in zone II was studied in chickens after using an artificial tendon sheath made of hydroxyapatite (HAp). The flexor sheath was excised between the proximal and distal pulleys in zone II to create a window in the fibro-osseous tunnel. After suturing the severed profundus tendon, an HAp sheath was placed around the suture site followed by 3 weeks of immobilization. The results were compared with controls in which no HAp sheaths were used after the operation. Adhesion formation was assessed both biomechanically and histologically. The mobility of the tendons was better in the HAp group at all the periods studied. HAp sheath was not firmly adherent to either the granulation tissue or the surface of the tendon. Histology at 3 as well as 6 weeks in HAp groups revealed epitenon-like structure on the tendon surface including the tenorrhaphy site and a wide space around the tendon after the HAp sheath was removed. The outer margins of this space was lined by a layer of fibrocyte-like cells and collagen fibers thereby resembling new formed tendon sheath. In the cases of control, marked peritendinous adhesions were observed.
To differentiate the functional changes from the organic changes in malignant hypertension, the author studied the changes in the blood vessel of ocular fundus by ophthalmoscopical and histopathological methods using malignant strain of stroke-prone spontaneously hypertensive rat (M-SHRSP; Okamoto, K et al., 1986), an animal model of human juvenile malignant hypertension, in which the systolic blood pressure elevates rapidly with age and death appeared by the 15th month of life, if they are untreated. Fundus changes progressed with age and duration of hypertension and they altered from functional changes to organic ones. In M-SHRSPs with age of 8 weeks, systolic blood pressure was 220mmHg or more and retinal arterioles showed generalised narrowing but no dye leakage was recognized by fluorescein angiography (FAG). Dye leakage was observed on the 9th week of age. Death of M-SHRSP appeared, after the 13th week of age, coincidentally with appearance of wide retinal edema. Papilledema appeared often in this period. Little histological change was found in the retinal arterioles in spite of severe and marked ophthalmoscopic changes. No feature of angionecrosis was observed in the retina while it was recognized in choroidal arteriole with thrombosis. The fundus changes in M-SHRSP were ophthalmoscopically classified by using scores as following. Grade 0: normal fundi, Grade I (score 1): slight generalized narrowing, caliber irregularity and tortuosity of the retinal arterioles, slight retinal edema and choroidal changes. Grade II (score 2): moderate generalised narrowing, caliber irregularity, tortuosity of the retinal arterioles, moderate retinal edema and choroidal ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
A 54-year-old man suddenly felt a strike on his chest while mowing with a machine. At first he had no symptoms except for wound pain, but several hours later, he suffered from high fever with chilliness. The chest roentgenogram showed a foreign body localized within the cardiac shadow. The echocardiogram revealed that the metallic fragment was embedded in the inferior wall of the left ventricle. It appeared that the fragment entered the left ventricular cavity through his anterior chest wall, the right ventricular outflow tract and the ventricular septum. At the operation, the location of the foreign body was again confirmed by the intraoperative echocardiography and the fragment was successfully removed through a left ventricular incision under cardiopulmonary bypass. The postoperative course was uneventful and the case was reported with a review of the literature.
We examined whether the gizzard MHC gene is expressed in other smooth muscle tissues and, if so, whether there exist any smooth muscle MHC isoforms at the mRNA level. Northern blot analysis showed that the gizzard MHC gene was also expressed in the aorta and jejunum, but not in the pectoralis muscle or in fibroblasts. This indicates that striated muscle and non-muscle MHC isoforms are encoded in genes distinct from the smooth muscle MHC gene. Further, nuclease S1 mapping showed that the aortic smooth muscle MHC mRNA was distinct from the gizzard mRNA in the 5'-terminal coding region. Both of these mRNA species are expressed in the jejunum. These observations suggest that there exist at least two chicken smooth muscle MHC isoforms, vascular-type and intestinal-type, and that these isoforms are generated from a single-copy gene, probably by an alternative mRNA processing mechanism.
On the basis of previous findings that N-acetyl nonapeptide from the human calpain I large subunit has chemotactic activity for neutrophils, a series of peptides with the N-terminal sequence of the calpain small subunit were synthesized and their chemotactic activity was examined. Potent activity was found in N-acetyl tetra, hepta, octa, nona and a larger peptide of 13 residues, although N-acetyl tripeptide showed only weak activity and N-acetyl penta and hexa peptides showed almost no activity. Since the small subunit is identical in calpains I and II, the results indicate that both calpains could be precursor proteins of chemotactic factors for neutrophils.
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Biological characteristics of alkaline phosphatase (ALP) from rat intestine were compared among four various fractions (brush border, cytosol, luminal and lymph) to clarify the source and route of ALP appeared in intestinal lymphatics. ALP of each fraction had the same Km values and the same heat stability and all were of intestinal type. However, lymph and cytosol ALP showed similar affinity to three kinds of lectins and were distinct from membrane and luminal ALP. On polyacrylamide gel electrophoresis (PAGE), there seems to be two types of charge isomers of intestinal ALP, namely brush border type and lymph type. On sodium dodecyl sulfate (SDS)-PAGE, the molecular weight of principal band for each form was: 130,000 for brush border type, and 160,000 for lymph type. Fat administration significantly increased the ALP activity in intestinal lumen and intestinal lymph. However, it did not change biological characteristics of ALP including binding ability to lectins and electrophoretic mobility in any of these four fractions. These results suggest that lymphatic ALP may be transported from cytosol of intestinal cells and that fat administration seems to induce quantitative change of intestinal ALP, but not to change its physiological route of transportation into intestinal lymph.
Thirty cases of colorectal adenocarcinoma were immunohistochemically examined to clarify the relationship between the degree of differentiation of cancer cells reflected by the mode of CEA localization and the infiltration pattern of mononuclear cells in the carcinoma tissues. Leu 1+, Leu 2a+, Leu 3a + 3b+ T lymphocytes, Leu 7+ cells, and IgA-containing plasma cells tended to be distributed more in areas where CEA was localized over the entire surface of the cancer cells or in their surrounding stroma than where CEA was located along the apical surface or within the cytoplasm. Carcinoma cells with the pattern of CEA staining at the former site were previously shown to be less differentiated than those at the latter. There were also CEA-containing phagocytes which were often observed where T cells and IgA plasma cells had aggregated. We speculated that the dedifferentiation of cancer cells might cause the host immune response, especially the cellular immunity, in malignant lesions.
We experienced surgical treatment on two patients having renal cell carcinoma with a tumor thrombus extending into the right atrium. In these patients, we performed nephrectomy, dissection of lymph nodes and removal of a tumor thrombus using cardiopulmonary bypass. One died of multiple organ failure 42 days postoperatively; the other was discharged from the hospital and is currently doing well 12 months after the operation. Cardiopulmonary bypass combined with hypothermia and low blood flow significantly facilitated removal of the tumor thrombus extending into the right atrium without the risk of pulmonary embolism or brisk hemorrhage.
Nuclear DNA ploidy pattern was examined in 22 breast carcinomas with a tumor mass of up to 2.2 cm and compared with the clinical and histological parameters of the malignant potentiality of breast carcinomas. The 22 carcinomas were divided into 11 aneuploid and 11 near-diploid carcinomas. It was found that the histological type, histological grade, nuclear grade, mitotic index and lymphatic invasion were either only slightly, or not correlated at all with the DNA ploidy pattern. Nevertheless, lymph node metastasis and negative estrogen receptor status was more frequently seen in the patients with aneuploid carcinoma than in those with near-diploid carcinoma.
The use of in situ gastroepiploic artery grafts has been reported recently. In the present case, the in situ gastroepiploic artery was too short to graft both the diagonal and the obtuse marginal branches of the coronary arteries in a patient with diffuse coronary artery disease. The free (aorta-coronary) gastroepiploic artery graft was anastomosed to both arteries to form a Y graft.
Serum anticolon antibody and in vitro anti-colon antibody production by peripheral blood and mucosal lymphocytes was investigated in patients with ulcerative colitis. The frequency of serum anticolon antibody was 71% in 41 patients with ulcerative colitis, estimated by enzyme linked immunosorbent assay (ELISA) using isolated rat colon epithelial cells. This finding confirms our previous report on the frequency of serum anticolon antibody detected by flow cytometry analysis. The estimated frequencies of IgG anticolon antibody secreting cells were 1.5-12.5/10(6) cells in the colonic mucosa and 0.1-0.5/10(6) cells in peripheral blood, from patients with ulcerative colitis when Epstein-Barr virus (EBV) was used as a B cell polyclonal activator. Poisson analysis of limiting dilution culture showed that about one per 140 IgG cells in the colonic mucosa synthesised anticolon antibody. Two monoclonal IgG antibodies were obtained from EBV transformed anticolon antibody secreting cells by limiting dilution method. One reacted with goblet cells in the intestine, and the other reacted mainly with colonic epithelial cells. These results suggest that heterogeneous anticolon antibodies are present in patients with ulcerative colitis and that colonic mucosa may be the main source of anticolon antibody. Local autoimmune reaction might have an important role in causing the inflammation of colonic mucosa in this disease.