Biomedical subjects

M Shimada

Publications and source records attributed to M Shimada.

At least 433 records · Page 24Linked to original sources

PubMed1996

[Adult T-cell leukemia with diffuse panbronchiolitis-like lung infiltration].

A 46-year old man was admitted complaining of dyspnea. Physical examination revealed superficial lymph nodes swelling, and coarse crackles over the lung. Chest X-ray film showed diffuse small granular shadows, suggesting diffuse panbronchiolitis (DPB). Peripheral blood smears showed cells with flower like nuclei. HTLV-I antibody was positive in the serum. He was diagnosed as having adult T-cell leukemia (ATL). Transbronchial lung biopsy showed diffuse infiltration of mononuclear cells around bronchioalveoli. The mononuclear cells stained positively for Pan T, CD2, CD3, CD4, CD5, CD25, and DNA from the cells showed HTLV-I provirus monoclonal integration. This is a rare case of ATL accompanied by DPB-like bronchioalveolar ATL cell infiltration.

Antigens, CD↗

PubMed1996

Differentiation of subgroups of type 2B with Sudan black B staining in rat skeletal muscle.

Using tibialis anterior, gastrocnemius lateralis, and masseter muscles of a male and a female normal Wistar rat, we examined the sensitivity of SBB staining to these muscles. We recognized that type 2A, 2B, and other types (type I, 2C and 2X) were darkly, lightly, and moderately stained by the SBB staining. Type 2B fibers identified by mATPase could be divided clearly into two subgroups by SBB staining. The dark population was type 2Bd that corresponded to type 2X, and the moderate one was 2Bm. Therefore, through the SBB staining it was possible to identify type 2Bd (2X) and 2Bm, as it is with SDH staining.

Animals↗

PubMed1995

Cloning and structural analysis of the mouse apolipoprotein B mRNA editing protein gene.

Mouse apolipoprotein B mRNA editing protein gene has been isolated and characterized. The amino acid sequences deduced from the exonic sequences of the gene showed 90, 70 and 68% identity to those of rat, human and rabbit, respectively. RNA blotting experiments demonstrated high expression in small intestine especially in the jejunum as a major 2.4 kb mRNA species. mRNA in other tissues including the liver is smaller in amounts and larger in size (3.1 kb) than the intestinal mRNA. The gene spans 12 kb and contains 5 exons and 4 introns. Sequencing of the 5'-flanking region revealed that a canonical TATA box is absent and the consensus recognition sequences for several transcription factors have been identified.

APOBEC-1 Deaminase↗

PubMed1995

Gene regulation by antisense DNA produced in vivo.

Antisense technology has been widely used for regulating gene expression. Single-stranded RNA or DNA complementary to a target mRNA can inhibit the translation of the mRNA. Antisense RNA is produced in vivo, while antisense DNA is chemically synthesized as an oligonucleotide, which is extracellularly added to the cells. To maintain the effect of antisense DNA, a synthetic oligonucleotide has to be constantly added to the system. An advantage of antisense DNA over antisense RNA is that the target mRNA hybridized with the antisense DNA can be specifically digested by ribonuclease H. Here, we attempted to produce in vivo short single-stranded DNAs complementary to a specific mRNA. We demonstrate that such antisense oligodeoxyribonucleotide of a desired sequence can be produced in Escherichia coli using a retron, a bacterial retroelement, as a vector and that the antisense DNA thus produced in vivo can effectively inhibit the expression of a specific E. coli gene, such as the gene for the major outer membrane lipoprotein.

Bacterial Outer Membrane Proteins↗

PubMed1995

Overexpression of human lipoprotein lipase increases hormone-sensitive lipase activity in adipose tissue of mice.

An elevation of lipoprotein lipase (LPL) activity in adipose tissue is considered a possible cause of obesity. However, transgenic mice that overexpress the human LPL gene showed no increase in fat deposition as compared with controls. In the present study, we investigated effects of LPL on fat accumulation. Respiratory quotients and uptake of [3H] triolein by tissues (white and brown adipose tissue, and skeletal muscles) did not differ significantly for transgenic and non-transgenic mice. The mRNA levels of hormone-sensitive lipase (HSL) and HSL activity in adipose tissue during feeding were higher in LPL transgenic mice than in controls. Results suggest that the overexpression of LPL does not induce obesity by enhancing the hydrolysis of triglycerides in adipose tissue.

Adipose Tissue↗

PubMed1995

Glial responses to hypoxic/ischemic encephalopathy in neonatal rat cerebrum.

This study was undertaken to examine glial responses in the immature rat brain to hypoxic/ischemic injury. The results indicate that developing microglia are the first and principle glial element that responds to hypoxic/ischemic injury during the neonatal period. The astrocyte response occurs later and macrophage infiltration may be delayed or absent.

Animals↗

PubMed1995

Role of macrophage colony-stimulating factor in the initial process of atherosclerosis.

The early atherosclerotic lesion is characterized by the presence of macrophage-derived foam cells. Macrophage colony-stimulating factor (M-CSF) specifically stimulates the functions of the monocyte-macrophages. To elucidate the role of M-CSF in the atherogenic process in vitro and in vivo, we studied the effects of M-CSF on enzyme activities of acidic cholesteryl ester (CE) hydrolase, neutral CE hydrolase, and acyl-coenzyme A:cholesterol acyltransferase (ACAT), and 300 micrograms of M-CSF was intravenously injected into WHHL rabbits aged 2.5 months for 8.5 months. M-CSF (100 ng/ml) enhanced acidic and neutral CE hydrolase, and ACAT activities by 3.2-fold, 4-fold, and 2.3-fold, respectively, in the presence of acetyl LDL, and M-CSF increased ratios of both acidic and neutral CE hydrolase activities to ACAT activity. After M-CSF injection into WHHL rabbits, we found very retarded progression of atherosclerosis. The accumulation of cholesterol ester was remarkably decreased in the aortae of M-CSF-treated animals (0.60 +/- 0.32 mg/g tissue), as compared to those of controls (4.21 +/- 0.65 mg/g tissue). The results suggest that M-CSF prevents the progression of atherosclerosis in WHHL rabbits by increasing net hydrolysis of cholesteryl ester in macrophages.

Animals↗

PubMed1995

Phylogenetic position of Rickettsia tsutsugamushi and the relationship among its antigenic variants by analyses of 16S rRNA gene sequences.

The 16S rRNA gene sequences of Rickettsia tsutsugamushi and Rickettsia sibirica were determined by PCR and DNA sequencing. Phylogenetic analysis revealed that R. sibirica is positioned in a cluster of the genus Rickettsia with a similarity value of 98.1-99.6%, whereas R. tsutsugamushi is located apart from the cluster with a similarity value of 90.2-90.6%. This evidence suggests that R. tsutsugamushi should be excluded taxonomically from the genus Rickettsia. The phylogenetic classification of six antigenic variants in R. tsutsugamushi moderately reflected their antigenic relationship known in closely and distantly related strains.

Antigens, Bacterial↗

PubMed1995

A new approach for liver surgery. Transdiaphragmatic hepatectomy for cirrhotic patients with hepatocellular carcinoma.

OBJECTIVE: To clarify the efficacy of transdiaphragmatic hepatectomy. DESIGN: Transdiaphragmatic hepatectomy and transabdominal hepatectomy were retrospectively compared. SETTING: This technique is used in cirrhotic patients with hepatocellular carcinoma located near the diaphragm. PATIENTS: Thirty-six cirrhotic patients with hepatocellular carcinoma who underwent transdiaphragmatic (group 1 [n = 8]) or transabdominal (group 2 [n = 28]) hepatectomies between April 1985 and March 1993 were investigated. All patients underwent a partial hepatectomy for hepatocellular carcinoma less than 3 cm in diameter located in segment VII or VIII or near the confluence of the hepatic veins. MAIN OUTCOME MEASURE: Intraoperative and postoperative clinical parameters, including operative time, blood loss, and length of hospital stay. RESULTS: The mean +/- SD operative time was significantly shorter in group 1 (184 +/- 25 minutes) than in group 2 (270 +/- 79 minutes). The intraoperative blood loss was significantly smaller in group 1 (857 +/- 622 mL) than in group 2 (1318 +/- 926 mL). The rate of postoperative complications was lower in group 1 (13% [n = 1]) than in group 2 (43% [n = 12]). The postoperative hospital stay was significantly shorter in group 1 (16 +/- 5 days) than in group 2 (23 +/- 16 days). CONCLUSIONS: Transdiaphragmatic hepatectomy is a useful technique for cirrhotic patients with hepatocellular carcinoma located near the diaphragm.

Abdomen↗

PubMed1995

Needle track seeding after percutaneous ethanol injection therapy for small hepatocellular carcinoma.

We present two cases of patients experiencing needle track seeding after undergoing percutaneous ethanol injection therapy (PEIT) for small hepatocellular carcinoma, who were treated by surgical resection of the metastases. One patient demonstrated metastatic tumors due to needle track seeding 6 months after the beginning of PEIT (a total of 7 injection sessions for 2 tumors measuring < 20 mm in diameters), whereas the other developed a metastatic tumor 20 months after beginning PEIT (a total of 30 injection sessions for 3 tumors measuring < 20 mm in diameter). In the two cases, both the primary and metastatic tumors histologically revealed moderately differentiated hepatocellular carcinoma. Moreover, the histological findings of the metastatic foci did not always appear to be more aggressive than those of the primary tumors. Therefore, in order to detect such metastasis as early as possible, more careful attention should be paid to the appearance of needle track seeding after performing PEIT for hepatocellular carcinoma, even if the target of such PEIT is small HCC.

Aged↗

PubMed1995

Significance of hyaluronic acid for evaluation of hepatic endothelial cell damage after cold preservation/reperfusion.

UNLABELLED: Serum hyaluronic acid (HA) levels during or after liver transplantation can reflect graft viability in animal models. Decreased HA clearance in nonviable grafts seems to reflect hepatic endothelial cell damage induced by cold preservation/reperfusion. Therefore, we examined the relationship between HA clearance and endothelial cell damage, using an isolated perfused rat liver (IPRL) model. The grafts were separated into four groups, according to cold preservation time: minimal storage ( CONTROL: n = 9), 4-hr preservation (n = 9), 5-hr preservation (n = 8), 6-hr preservation (n = 9). After cold storage, grafts were put on the recirculating IPRL system and then reperfused for 120 min with 37 degrees C oxygenated Krebs-Henseleit buffer, containing HA and sodium taurocholate. To examine the function of sinusoidal endothelial cells and hepatocytes, serial measurements of HA, total bile acids, and conventional parameters in the perfusate were taken. After the perfusion, a trypan blue exclusion test was done to assess the microscopic sinusoidal lining cell (SLC) damage. HA clearance from the perfusate showed a preservation time-dependent decrease which clearly distinguished between 4- and 6-hr preserved grafts. Trypan blue uptake ratio of SLC increased in accordance with preservation time. HA clearance at 120 min after reperfusion showed a highly significant correlation with histologically assessed SLC damage. These results suggest that HA is useful to evaluate the extent of endothelial cell damage after cold storage and reperfusion. The significance of HA as a predictor of graft viability is also confirmed.

Animals↗

PubMed1995

Occurrence of intraperitoneal septic complications after hepatic resections between 1985 and 1990.

In this study, the risk factors related to intraperitoneal septic complications occurring after hepatectomy (IPSCH) as well as the effect of various perioperative variables on the outcome of IPSCH between 1985 and 1990 were analyzed. Twenty-one of 211 patients (10.0%) developed IPSCH. The findings in the patients with IPSCH were compared with those in 190 patients without IPSCH. The significant variables associated with the development of IPSCH included a high incidence of accompanying chronic renal failure (14.3% vs 2.1%), a larger blood loss during surgery (2,130 vs 1,340 ml) as well as a greater amount of intraoperative blood replacement (1,130 vs 570 ml), and a greater weight of the resected liver (367 vs 233 g). IPSCH occurred in 10 of 12 patients who had postoperative bile leakage. Eighteen patients (85.7%) with IPSCH were discharged from the hospital after non-operative management; however, the hospital death rate (14.3% vs 1.1%) was significantly higher in patients with IPSCH. This review suggests that the incidence of IPSCH has not decreased recently. Thus, to prevent IPSCH, at least following bile leakage, it is necessary to perform a careful division of the liver parenchyma followed by a bile leakage test, and when this complication occurs unexpectedly in patients who have a good functional reserve of the remnant liver, IPSCH can be effectively drained percutaneously under ultrasound guidance.

Abdominal Abscess↗

PubMed1995

Pulmonary atresia with intact ventricular septum: long-term results of "one and a half ventricular repair".

BACKGROUND: Between 1982 and 1984, we successfully performed "one and a half ventricular repair" using a Glenn shunt for 3 patients with pulmonary atresia with intact ventricular septum. Here we review the 10-year follow-up results. METHODS: In these patients, the preoperative Z scores of the tricuspid valve diameters ranged from -5.2 to -6.5. Right ventricular outflow tract reconstruction combined with a Glenn shunt were performed in all patients. Cardiac catheterization was done at least 10 years post-operatively. RESULTS: All 3 patients have maintained New York Heart Association functional class I status for more than 10 years. Angiography in 2 patients confirms sufficient left pulmonary artery pressure with pulsatile blood flow and good right ventricular contraction. A pulmonary arteriovenous fistula has developed in 1 patient. CONCLUSIONS: Although the lower limits of the tricuspid valve diameter for "one and a half ventricular repair" using a cavopulmonary shunt have not yet been determined, we successfully performed this procedure in 3 patients with severely hypoplastic right ventricles and tricuspid valve diameter Z scores of less than -5.0. The results up to 10 years postoperatively are acceptable.

Cardiac Surgical Procedures↗

PubMed1995

Successful management of infantile hepatic hilar hemangioendothelioma with obstructive jaundice and consumption coagulopathy.

A 4-month-old boy with benign hemangioma of the porta hepatis is described. Obstructive jaundice and consumption coagulopathy developed, which were treated by percutaneous transhepatic drainage (PTHD), without resection of the tumor or bypass surgery. Because of tumor regression, the patient has remained free of symptoms even after the PTHD tube was removed. Because juvenile hemangioma is a benign tumor and occasional spontaneous regression is known to occur (as in our case and other reports), it is suggested that complete resection or bypass surgery is not necessary for juvenile hemangioendothelioma, even with obstructive jaundice, if bile drainage is adequately maintained.

Cholestasis↗

PubMed1995

Induction of aneuploidy in Chinese hamster oocytes following in vivo treatments with trimethoxybenzoic compounds and their analogues.

Many inhibitors of tubulin polymerization have a trimethoxybenzene ring in their molecules. Such trimethoxybenzoic compounds and their analogues may therefore have a potency to induce meiotic nondisjunction of oocytes. In this study, a single dose of reserpine (0.5 microgram/g body weight), podophyllotoxin (20.0 micrograms/g b.w.), trimethoxybenzoic acid (500.0 micrograms/g b.w.) or vinblastine sulfate (3.0 micrograms/g b.w.) was injected intraperitoneally to mature female Chinese hamsters at the onset of the first meiotic spindle formation of oocytes. Within 6 h after spontaneous ovulation, MII oocytes were collected from the oviducts for morphological examination and cytogenetic analysis. The incidence of morphologically abnormal oocytes with unusually large first polar body or bodies increased significantly after the treatment with reserpine (18/202; 8.9%), podophyllotoxin (28/172; 16.3%) and vinblastine sulfate (63/197; 32.0%), as compared with the control (3/214; 1.4%). Chromosome analysis of oocytes revealed that podophyllotoxin and vinblastine sulfate were effective in inducing aneuploidy (62/154; 40.3% and 128/156; 82.1% vs. 3/198; 1.5% of the control) by inhibiting the formation of spindle microtubules at the first meiosis. Aneuploids were found more frequently in morphologically abnormal oocytes than in normal oocytes. No aneugenic activity of reserpine and trimethoxybenzoic acid was observed. These results indicate that trimethoxybenzoic compounds do not necessarily exhibit aneugenic activity.

Aneuploidy↗

PubMed1995

Partial hepatic grafting: porcine study on critical volume reduction.

BACKGROUND: The safe limit of volume reduction in partial hepatic transplantation, including extracorporeal hepatic resection, remains to be clarified. This study evaluated such a limit and pathologic features associated with transplantation of a less than critical volume. METHODS: Partial hepatic grafting was performed in a porcine orthotopic autotransplantation model. According to the remnant liver volume, animals were classified into three groups: group 1, 73.8% +/- 4.2% (SD); group 2, 52.6% +/- 6.7%; and group 3, 29.4% +/- 6.7% of the whole liver (n = 5 each). RESULTS: Three-day survival was achieved in five (100%), four (80%), and zero animals, respectively. All animals in group 3 died of graft nonfunction; their intraoperative clearance of the total bile acids was significantly worse than the other groups (p < 0.01). After operation the clearance of the total bile acids and hyaluronic acid, which is selectively cleared by hepatic endothelial cells, was significantly better in group 1 than group 2 (p < 0.01 and < 0.05, respectively). On histologic examination postperfusion biopsy specimens of group 3 exhibited severe ischemic changes and portosinusoidal hyperemia, whereas that of groups 1 and 2 exhibited only mild ischemic damages. CONCLUSIONS: Transplantation of less than 30% of expected full liver volume could lead to primary graft nonfunction after partial hepatic grafting.

Animals↗

PubMed1995

Enhanced efficacy of bleomycin adsorbed on silica particles against lymph node metastasis in patients with esophageal cancer: a pilot study.

BACKGROUND: Lymph node metastases occur very frequently and extensively in patients with esophageal cancer. The aim of this pilot study was to try the targeting chemotherapy for lymph node metastases by use of bleomycin adsorbed on silica particles (BLM-SI). METHODS: BLM-SI or bleomycin solution (BLM-SOL) was injected into the submucosa of the esophageal wall by means of endoscopy 3 days before operation in 16 patients with middle thoracic esophageal cancer. The distribution of bleomycin in the regional lymph nodes and surrounding connective tissues was studied. RESULTS: When BLM-SI was administered, bleomycin activity was found in both the regional lymph nodes and connective tissues, not only in the mediastinal region but also in the cervical and abdominal region. Bleomycin activity was significantly higher in all regions after BLM-SI administration than after BLM-SOL administration. Degenerative or necrotic changes were microscopically observed in 11 of 36 lymph nodes with metastatic foci. Bleomycin activity in the blood was significantly lower after BLM-SI was administered than after BLM-SOL. Serious systemic side effects except for fever were not observed in any patients. CONCLUSIONS: These results indicate that BLM-SI could be a useful treatment modality for targeting lymph node metastasis of esophageal cancer without serious side effects.

Adsorption↗

PubMed1995

GLUT-1 glucose transporter is localized heterogeneously within the microvessels of the mouse hippocampus.

We investigated the distribution of the glucose transporter protein within the microvessels in the mouse hippocampus by immunohistochemical methods with an anti-rat brain glucose transporter 1 (GLUT-1) and confocal laser scanning microscopy. All intraparenchymal microvessels in the hippocampus showed intensive immunoreactivity and a heterogeneous distribution of GLUT-1 was seen in the microvessels. These data may suggest that glucose could be heterogeneously incorporated into the endothelial cells of the cerebral microvessels, and therefore morphological and physiological differences may be present among the endothelial cells.

Animals↗