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Biomedical subjects

H Hamada

Publications and source records attributed to H Hamada.

At least 361 records · Page 20Linked to original sources
PubMed1994

[Damus-Kaye-Stansel procedure following Van Praagh (PA-descending Ao shunt) for complete transposition of the great arteries, hypoplastic aortic arch and coarctation].

A newborn baby with d-TGA, straddling AV valve, large VSD, hypoplastic ascending aorta and coarctation of the aorta had congestive heart failure and oliguria on the 3rd day after birth. Van Praagh's operation (main pulmonary artery to descending aorta bypassing with synthetic graft) was performed on 4 days of age through a lateral thoracotomy. At the age of 2 months, the patient underwent left pulmonary artery banding because of respiratory insufficiency requiring prolonged ventilatory support. The patient subsequently underwent Damus-Kaye-Stansel procedure without enlargement of the arch, and the pulmonary patch angioplasty with right modified BT shunt on the age of 5 months. This baby was discharged on 4 months after the operation. Two-dimensional echocardiography has shown aortic and pulmonary competence postoperatively.

Anastomosis, Surgical↗
PubMed1993

Molecular cloning and characterization of the complementary DNA for the M(r) 85,000 protein overexpressed in adriamycin-resistant human tumor cells.

An M(r) 85,000 membrane protein was identified by a monoclonal antibody MRK20 raised against an Adriamycin-resistant subline of human myelogenous leukemia K562 (K562/ADM) cells. The M(r) 85,000 protein was found to be overexpressed in both innate and acquired Adriamycin-resistant tumor lines. A complementary DNA (cDNA) clone coding for the M(r) 85,000 protein was isolated by mixed oligonucleotide-primed polymerase chain reaction and further screening of a cDNA library from K562/ADM. Amino acid and nucleotide sequence analysis of the M(r) 85,000 protein revealed that this protein is identical with CD36, a cell surface adhesion molecule of endothelium, platelets, and monocytes. We constructed an expression vector utilizing two different promoters, SV40 and MMTV, and two cDNAs for the M(r) 85,000 protein that have different 3'-ends. DNA transfection experiments were carried out by the calcium phosphate method with a selectable marker using drug-sensitive human tumor lines KB3-1 and A2780 as recipient cells. We obtained transfectant clones expressing the M(r) 85,000 protein stably or inducibly but found no resistance against Adriamycin or vincristine. Direct selection with Adriamycin or vincristine or tumor cells transfected with the SV40 promoter-regulated expression constructs also failed to yield drug-resistant clones. These results indicate that the M(r) 85,000 protein/CD36 cannot confer drug resistance by itself, even though the protein can be an effective marker for Adriamycin resistance.

Amino Acid Sequence↗
PubMed1993

Vaccination with irradiated tumor cells engineered to secrete murine granulocyte-macrophage colony-stimulating factor stimulates potent, specific, and long-lasting anti-tumor immunity.

To compare the ability of different cytokines and other molecules to enhance the immunogenicity of tumor cells, we generated 10 retroviruses encoding potential immunomodulators and studied the vaccination properties of murine tumor cells transduced by the viruses. Using a B16 melanoma model, in which irradiated tumor cells alone do not stimulate significant anti-tumor immunity, we found that irradiated tumor cells expressing murine granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulated potent, long-lasting, and specific anti-tumor immunity, requiring both CD4+ and CD8+ cells. Irradiated cells expressing interleukins 4 and 6 also stimulated detectable, but weaker, activity. In contrast to the B16 system, we found that in a number of other tumor models, the levels of anti-tumor immunity reported previously in cytokine gene transfer studies involving live, transduced cells could be achieved through the use of irradiated cells alone. Nevertheless, manipulation of the vaccine or challenge doses made it possible to demonstrate the activity of murine GM-CSF in those systems as well. Overall, our results have important implications for the clinical use of genetically modified tumor cells as therapeutic cancer vaccines.

Animals↗
PubMed1993

Hybrid cell extinction and re-expression of Oct-3 function correlates with differentiation potential.

The Oct-3 gene is expressed in highly undifferentiated cells and is implicated in mammalian early embryogenesis. We have generated a series of hybrid cells between pluripotent embryonal carcinoma cells (Oct-3+) and fibroblasts (Oct-3-), and have studied the regulation and function of Oct-3. Upon fusion, the hybrid cells differentiated to nestin+/Brn-2+ cells resembling neuroepithelial stem cells. Expression of Oct-3 was extinguished at the transcriptional level in all the hybrid cells examined. The Oct-3 modulating activity required for the Oct-3-mediated enhancer activation was also extinguished. When the Oct-3 transactivating function was introduced into the hybrid cells, they transformed into morphologically distinct nestin-/Brn-2- cells ('revertants'). When the 'revertant' cells subsequently lost Oct-3 expression, they differentiated back to nestin+/Brn-2+ cells. The close correlation between the phenotypic changes and the gain/loss of Oct-3 function indicates that Oct-3 can induce dedifferentiation of the neural cells.

Animals↗
PubMed1993

Free radical scavenging action of baicalein.

TJ-960 is a Japanese Kampo (traditional herbal) medicine used for the treatment of epilepsy. It's a crude drug, an extract of nine herbs, and consists of many known and unknown components. Among the known components of TJ-960, we found that 5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one (baicalein) might be the most potent scavenger for radicals. In the present study, we examined in vitro the radical scavenging effect of baicalein in detail using electron spin resonance spectrometry. Furthermore, we examined in vivo its effect on the thiobarbituric acid-reactive substances (TBARS) levels and superoxide dismutase in the brain of rats with FeCl3-induced epilepsy and on hippocampal delayed neuronal death in gerbils with transient ischemia. In in vitro experiments, baicalein quenched in a dose-dependent manner 1,1-diphenyl-2-picrylhydrazyl, superoxide, and hydroxyl radicals. In the FeCl3-induced epileptic model, baicalein suppressed the increase in the TBARS level at the FeCl3-injected site. Baicalein also inhibited hippocampal neuronal death induced by 5 min of cerebral ischemia in gerbils. Hence the present study suggested that baicalein is one of the active components in TJ-960, which partially contributes to the antiepileptic and neuronal protective effects of TJ-960, and that the mechanism of its pharmacological action is based upon radical quenching and antioxidative effects.

Animals↗
PubMed1993

Fetal nucleated cells in maternal peripheral blood: frequency and relationship to gestational age.

To determine the frequency of fetal nucleated cells in maternal peripheral blood during different stages of pregnancy, 50 primigravidas were investigated by determining the frequency of cells with the Y chromosome using fluorescence in situ hybridization (FISH) of Y-specific repetitive sequences of the DYZ1 family. Polymerase chain reaction (PCR) amplifying the same part of the DYZ1 used as the probe in FISH and a single-copy Y-specific fragment was also carried out for genomic DNA from the same samples. Cells with the hybridization signal were detected by FISH at and after 15 weeks of pregnancy in all pregnant women who gave birth to boys. The ratio of cells with the signal to those without the signal ranged from 1 in 144,000 to 1 in 4,000 with a tendency to increase as the pregnancy advanced. The frequency of fetal cells estimated by the PCR experiments was significantly and positively correlated with that found by FISH. The present study suggests that fetal nucleated cells increase in maternal peripheral blood with advancing gestation, from less than 1 in 100,000 nucleated cells in the first trimester to around 1 in 10,000 at term. These frequencies were much lower than those reported by cytological methods.

Blood Cell Count↗
PubMed1993

Changes in circulating blood volume following isoflurane or sevoflurane anesthesia.

Changes of circulating blood volume (CB volume) measured by the dual indicator dilution method were observed in 33 chronically instrumented mongrel dogs following either alpha-chloralose-urethane (C group), additive isoflurane (I group) or sevoflurane anesthesia (S group). These anesthetic groups were each divided into two subgroups with regard to respiratory care, namely Cp, Ip and Sp for those with intermittent positive pressure ventilation (six animals per subgroups), and Cs, Is and Ss for those with spontaneous breathing (five animals per subgroups). The CB volume under positive pressure ventilation remained unchanged in the Ip and Sp groups at both 0.5 and 1.0 MAC, and in the Cp group. The CB volume remained essentially unchanged in the Cs and Is groups at both 0.5 or 1.0 MAC, but the plasma volume tended to increase slightly in the Is group at 1.0 MAC. In the Ss group under spontaneous breathing, however, the CB volume increased from 84.4 +/- 7.0 to 91.4 +/- 7.7 at 0.5 MAC, and to 91.4 +/- 10.2 ml.kg(-1) at 1.0 MAC (0.01 < P < 0.05). These increases were caused by an increase in the plasma volume. The above data suggests that a concomitant increase in the venous pressure associated with an increase in the intrathoracic pressure produced by positive pressure ventilation would attenuate changes in the CB volume during sevoflurane anesthesia.

Journal Article↗
PubMed1993

Extradural spinal angiolipoma: report of a case studied with MRI.

The current report describes a case of extradural angiolipoma with spinal cord compression that was studied by magnetic resonance imaging. In considering the strategy for the surgical management, it is desirable to determine the histologic type of spinal cord tumors before the operation. The literature of spinal angiolipoma is reviewed, and the possibility of using magnetic resonance imaging to define the histologic type of spinal cord tumors before operation is discussed.

Dura Mater↗
PubMed1993

A CNS-specific POU transcription factor, Brn-2, is required for establishing mammalian neural cell lineages.

The pluripotent embryonal carcinoma cell line P19 can differentiate in vitro into neurons and astrocytes. By employing this neural cell differentiation system, we have studied the expression and function of a POU transcription factor implicated in mammalian neurogenesis. When P19 cells differentiated to the neural cells, one of the CNS-specific POU genes (Brn-2) was selectively induced. The induction of Brn-2 was specific to the neural cell lineages and took place at the early stage of differentiation. When the Brn-2 induction was blocked/delayed by antisense RNA, such cells were unable to differentiate to neurons and astrocytes. Instead they differentiated to nonneural cells, including smooth and skeletal muscle cells. Furthermore, with reduced levels of antisense RNA, differentiation to neural cells occurred. These results indicate that Brn-2 is essential for the neural cell differentiation of P19 cells and suggest that Brn-2 is one of the genes required for establishing neural cell lineages in mammals.

Animals↗
PubMed1993

KL-6, a mucin-like glycoprotein, in bronchoalveolar lavage fluid from patients with interstitial lung disease.

KL-6, a mucin-like high-molecular-weight glycoprotein, is a serum marker indicating the disease activity of pneumonitis, such as idiopathic pulmonary fibrosis (IPF), hypersensitivity pneumonitis, and sarcoidosis. Immunohistochemical studies have shown that KL-6 is strongly expressed on Type 2 pneumocytes and also exists on epithelial cells in other organs. It has not been clarified whether the increased levels of KL-6 in sera from patients with pneumonitis are derived from the lower respiratory tract. In this study, KL-6 levels were evaluated in bronchoalveolar lavage fluid (BALF) samples from 9 healthy control subjects and 32 patients with interstitial pneumonitis. An abnormally high level of KL-6 in BALF was observed in 70% (7 of 10) of patients with IPF, 64% (9 of 14) of patients with sarcoidosis, and 100% (8 of 8) of patients with hypersensitivity pneumonitis but in none of the healthy control subjects. KL-6 levels in BALF were significantly correlated with numbers of total cells (p < 0.001), lymphocytes (p < 0.001), and neutrophils (p < 0.05) and with concentrations of albumin (p < 0.001) and total protein (p < 0.001) in BALF and, further, with serum KL-6 levels (p < 0.01). These results indicate that increased levels of serum KL-6 in patients with pneumonitis reflect the production levels of KL-6 derived from damaged or regenerating Type 2 pneumocytes in the lower respiratory tract.

Alveolitis, Extrinsic Allergic↗
PubMed1993

Acetaminophen-induced eosinophilic pneumonia.

We present the first case (to our knowledge) of acetaminophen-induced eosinophilic pneumonia. Although the patient had taken an acetaminophen-containing combination drug, Kinuya-chinnetsu, for only three days, the abnormal shadow on his chest radiograph continued for about a month. Lymphocyte stimulation tests showed that both Kinuya-chinnetsu and acetaminophen induced the proliferation of peripheral blood lymphocytes.

Acetaminophen↗
PubMed1993

What factors are involved in the knowledge necessary for the self-management of diabetic patients?

The aim of this study is to obtain data for improving a training program for patients with diabetes mellitus. One hundred eighty-seven patients with non-insulin dependent diabetes mellitus were tested with 20 questions about their knowledge for self-management of diabetes mellitus. Then to draw out factors in their personal backgrounds relating to their correct answers, multiple regression analyses were conducted. As a result, four factors showed significant differences in the following order: Educational careers > ages > duration of disease > socioeconomic strata. The results of the present study have shown for the first time, that these four factors closely concern patients to acquire the necessary knowledge for their self-management of the disease. In addition, this study has raised some fundamental problems regarding the training program for patients: how education should be given to patients.

Adolescent↗
PubMed1993

Basic studies on visible light-cured resin as a denture base. Part 17. Transverse and tensile strengths of repaired denture base resin using a trial repair resin.

Trial production of a visible light-cured repair resin (powder/liquid type, TPL) as a denture base resin was carried out using cyclophosphazene monomer, and then the transverse and tensile strengths of the repaired specimens were examined. As a control, Triad Gel (TRI) was used. In the transverse strength test, TPL showed values of 507-470 kgf/cm2, which were about double those of TRI. As for tensile strength, TPL showed values of 329-268 kgf/cm2, and higher values were obtained in comparison with TRI, especially after 30 days of water immersion, when the values were doubled. The durability of TPL was favorable in comparison with TRI.

Composite Resins↗
PubMed1993

[A case of diffuse panbronchiolitis associated with tracheomalacia].

A 71-year-old male had suffered from cough with purulent sputum. He was admitted to our hospital because of worsening of his symptoms. The chest X-ray film showed diffuse nodular shadows and emphysematous changes in both lung fields. Transbronchial lung biopsy demonstrated findings compatible with diffuse panbronchiolitis (DPB). Bronchoscopy showed the tracheal lumen was sagittaly narrowed and membranous portion was protruded into the lumen. The trachea completely collapsed when coughing. His disease was diagnosed as saber-sheath type tracheomalacia (Johnson III). Tracheomalacia was reported to be observed in 0.9% of patients examined by bronchoscopy. The dominant type of tracheomalacia is crescent type, and saber-sheath type is rare. Chronic airway inflammation with DPB might have exacerbated the tracheomalacia in this case.

Aged↗
PubMed1993

Pregnancy complicated by the May-Hegglin anomaly.

May-Hegglin anomaly is a prepotent autosomal hereditary disease characterized by giant thrombocytes, thrombocytopenia and continuous appearance of inclusion bodies (Döhle like corpuscle) in the cytoplasm of granulocytes. In this report we report our experience of a case whose pregnancy was complicated by this disease. This anomaly is rare and there are only 15 families reported in this country. The only clinical symptom is the tendency to bleed, but since this is not rare, it may be necessary to consider examination of peripheral blood in every case of thrombocytopenia. If this disease complicates pregnancy, it is important to plan the mode of delivery to consider both the maternal and fetal prognosis.

Adult↗
PubMed1993

[The effect of isoflurane or sevoflurane on circulating blood volume--study under spontaneous breathing].

Changes in circulating blood volume during isoflurane or sevoflurane anesthesia under spontaneous breathing were investigated by the dual indicator dilution method in 13 mongrel dogs. The animals were randomly divided into three groups; control (C) group n = 5, isoflurane (I) group n = 5, and sevoflurane (S) group n = 5. Changes in circulating blood volume (ml.kg-1) at 0, 0.5, 1.0 MAC were 87.7 +/- 8.2-->88.7 +/- 5.0-->91.0 +/- 5.9 in the I group and 84.4 +/- 7.0-->91.4 +/- 7.7-->91.4 +/- 10.2 in the S group, respectively. In the S group, circulating blood volume and plasma volume increased significantly, while in the I group the volumes tended merely to increase. Arterial carbon dioxide tension (PaCO2) in the I and S groups increased significantly at 0.5 and 1.0 MAC, but similar changes were also noted (not significantly) in the C group. Mean arterial pressure, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure tended to increase at 0.5 and 1.0 MAC in the C and I groups, but tended to decrease in the S group. The results suggest that the increase in vascular compliance with sevoflurane under spontaneous breathing has resulted in the increase in plasma volume and circulating blood volume.

Anesthesia, Inhalation↗
PubMed1993

[Effects of medium chain triglyceride administration on liver regeneration after partial hepatectomy in rats].

The influence of lipid emulsion, especially medium chain triglyceride (MCT), on liver regeneration was investigated after 70% hepatectomy in rats. The rats received one of the following 3 solutions as a fuel source in total parenteral nutrition (TPN) regimen: a glucose solution (Group-G), a mixture of long chain triglyceride (LCT) and glucose (Group-L), or a mixture of MCT and glucose (Group-M). The calorie ratio of fat to glucose in LCT and MCT was 1 to 1. The energy charge (EC) of the regenerating liver decreased at 6 or 12 hours after hepatectomy and returned to the pre-operative level at 24 hours in each group. But EC at 6 hours was significantly higher in group-M than in group-G. Lipoperoxide (LPO) in regenerating liver was significantly lower in group-Mand-L than in group-G at 12 hours after hepatectomy, but it was significantly higher in group-M than in group-G and -L at 48 hours. Labeling index (LI) of bromodeoxyuridine (BrdU) was significantly higher in group-Mand L than in group-G at 24 hours after hepatectomy. These results indicate that MCT may be beneficial energy substrates in acute phase of regenerating liver. Although lipid emulsion has beneficial effect on the liver regeneration after hepatectomy, in recovery phase of liver regeneration, addition of LCT with MCT may be considered more beneficial.

Adenine Nucleotides↗