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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 325 records · Page 18Linked to original sources
PubMed1999

Contribution of endothelin-1 to disruption of blood-brain barrier permeability in dogs.

We examined the effect of intracisternal application of endothelin-1 (ET-1) on the permeability of fluorescein into the cerebrospinal fluid (CSF) in beagle dogs in order to evaluate its role in disruption of blood-brain barrier (BBB) permeability seen in the subarachnoid hemorrhage animal model. Intracisternal application of their autologous blood for producing a canine two-hemorrhage model revealed an enhanced fluorescein permeability into the CSF together with the development of cerebral vasospasm. A single dose of ET-1 (40 pmol/animal) significantly increased penetration of fluorescein compared with that in normal dogs. Although its magnitude was much less than that in the two-hemorrhage model after the first administration of ET-1, the second challenge of the same dose of ET-1 with a 48-h interval produced marked disruption of BBB permeability similar to those in the animal model. Moreover, the ET-1-induced enhancement of fluorescein permeability into the CSF was completely prevented by intracisternal pretreatment with an endothelin ET(A)-receptor selective antagonist, S-0139 (0.03 mg/kg), as were the ET-1-induced cerebral vasoconstriction and behavioral changes as previously reported. Thus, we conclude that ET-1 acting on the adventitial site of brain in dogs contributes to the disruption of BBB permeability via endothelin ET(A)-receptor mediation.

Analysis of Variance↗
PubMed1999

Anterior transhepatic approach for isolated resection of the caudate lobe of the liver.

We have devised a new technique for isolated caudate lobe resection in which we access the caudate lobe by separating the liver parenchyma along the interlobar plane. The safety and radicality of the procedure were evaluated in five patients: four with hepatocellular carcinoma (HCC) and one with metastatic rectal cancer. All of the tumors were located mainly in the paracaval portion of the caudate lobe. The patients with HCC (three of four) underwent an anatomic caudate lobe resection by identification of the right margin of the caudate lobe. Two patients required red blood cell transfusion, and one showed bile leakage after surgery. All of the patients are alive without recurrence more than 4 years after surgery, except one with rectal carcinoma who developed lung metastases. The anterior transhepatic approach is a safe and potentially curative surgical option for a tumor in the paracaval portion of the caudate lobe.

Aged↗
PubMed1999

Repeat liver resection for recurrent colorectal liver metastases.

BACKGROUND: This study aimed to delineate the role of surgery for recurrent colorectal cancer in the liver and to identify prognosticators for better patient selection and outcome. METHODS: Data from 90 repeat hepatectomies (second = 75; third = 12; fourth = 3) for recurrent colorectal cancer were collected. RESULTS: After the second hepatectomy, the 3-and 5-year survival rates were 48% and 31%, respectively. Twenty-seven percent (20 of 75) of patients are alive without recurrence after a median follow-up of 27 months, and 9 survived more than 5 years. Four or more tumors, positive regional lymph node metastases, concomitant extrahepatic disease, and residual tumor were independent poor prognostic factors after the second hepatectomy. CONCLUSIONS: Repeat hepatectomy should be applied for recurrent colorectal cancer, when curative removal of the tumor is possible, although the benefit from treatment was limited in a patient with regional lymph node metastases, 4 or more metastases, or extrahepatic disease.

Adult↗
PubMed1999

Healing of the intimal dissection of the internal thoracic artery graft.

We report healing of the intimal dissection of an internal thoracic artery graft. Triple coronary artery bypass grafting was performed using left internal thoracic artery and saphenous vein grafts. One month after operation, the intimal dissection of the internal thoracic artery graft was clearly visible by coronary angiography; however, after 1 year of only medical treatment consisting of warfarin, ticlopidine, and nitrate, the intimal dissection was undetectable by coronary angiography.

Aged↗
PubMed1999

Iodine-impregnated drapes enable recording of precordial electrocardiogram.

Although we believed that the use of a polyester film drape for primary elective open sternum with delayed sternal closure made it impossible to record precordial electrocardiograms on the drape, we confirmed that it is possible to record electrocardiograms on an iodine-impregnated drape due to the iodine anion electrical conductibility.

Electric Conductivity↗
PubMed1999

Effects of troglitazone on atherogenic lipoprotein phenotype in coronary patients with insulin resistance.

Insulin resistance is associated with atherogenic lipoprotein phenotype, including small dense LDL particle, hypertriglycemia and low HDL cholesterol levels. Troglitazone, a novel insulin sensitizing agent, may improve the associated lipid profile in patients with insulin resistance. We examined the effects of troglitazone (400 mg daily for 12 weeks) in 12 non-diabetic coronary patients (60+/-10 years), all of whom had hyperinsulinemic response to an oral glucose load. Troglitazone markedly reduced the insulin response. After the treatment, plasma triglycerides decreased by 32% (P<0.05), HDL cholesterol increased by 11%, (P<0.05) and LDL peak particle diameter increased from 24.7+/-0.3 to 25.5+/-0.5 nm (P<0.01). These lipidic improvements were associated with a significant rise in postheparin lipoprotein lipase levels (175+/-52 to 217+/-69 ng/ml, P<0.01). In patients with insulin resistance syndrome, troglitazone improved the atherogenic lipoprotein phenotype as well as hyperinsulinemia. Our data suggest that troglitazone therapy could reduce the atherosclerotic risk due to insulin resistance even in non-diabetic patients.

Aged↗
PubMed1999

In vitro and in vivo glucuronidation of 24,25-dihydroxyvitamin D3.

Glucuronidation of 24,25-dihydroxyvitamin D3 has been investigated in in vitro and in vivo experiments. Three positional isomers of 24,25-dihydroxyvitamin D3 monoglucuronide were synthesized from 24,25-dihydroxyprovitamin D3 derivatives with Koenigs-Knorr reaction and used as standard samples. In the presence of the rat liver microsomal fraction and uridine-5'-diphosphoglucuronic acid, 24,25-dihydroxyvitamin D3 gave 3- and 24-glucuronides as the main products in almost equal amounts, but only a small amount of the corresponding 25-glucuronide was obtained. 24,25-Dihydroxyvitamin D3 monoglucuronide was deconjugated with rat intestine homogenate, which indicated the entero-hepatic circulation of 24,25-dihydroxyvitamin D3. After the administration of 24,25-dihydroxyvitamin D3 to rats, its 3- and 24-glucuronides were identified from the bile as inferred from the in vitro experiment. However, the in vivo glucuronidation occurred at the 24-position in preference to the 3-position, and the corresponding 25-glucuronide was not detected. These glucuronides were identified in comparison with standard samples based on their chromatographic behavior during high-performance liquid chromatography and data obtained from liquid chromatography-electrospray ionization-mass spectrometry, which was helpful in identifying these compounds.

24,25-Dihydroxyvitamin D 3↗
PubMed1999

Burn due to misuse of an acetylene gas burner: a case report.

A rare case of deep penetrating burn injury caused by misuse of a high-pressure acetylene burner is reported. A 35 year old man was admitted with second and third degree burns involving the right arm cubital area and a subcutaneous burn on his right arm caused by a high-pressure acetylene gas flame. Early surgical debridement and secondary skin grafting using a preserved subcutaneous vascular network skin graft (PSVNSG) proved effective in this patient. Skin contracture was prevented and function was recovered. The basis of PSVNSG is that the vascular system existing in the graft is used as a permanent vascular system without degeneration. This case shows that, in this kind of burn injury, subcutaneous tissue damage should be suspected and that it is important to perform surgical debridement early after admission.

Accidents, Home↗
PubMed1999

Screening of antioxidant action of various molds and protection of Monascus anka against experimentally induced liver injuries of rats.

Antioxidant action of various molds, which are traditionally used for the production of foods or alcoholic beverages in Japan, was studied in vitro and in vivo. Antioxidant action was evaluated by scavenging stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation of rat liver microsomes. Among 40 molds, 16 species showed the DPPH scavenging action, and the molds that can scavenge the DPPH radical inhibited lipid peroxidation. The mold with the strongest action, Monascus anka, was chosen for the investigation of a protective action against liver injury of rats. When galactosamine (GalN, 400 mg/kg) or GalN plus lipopolysaccharide (LPS, 0.5 microg/kg) was given intraperitoneally to rats (Sprague-Dawley), aspartate aminotransferase (AST) and glutathione (GSH) S-transferase (GST) activities in serum were significantly increased. However, such hepatotoxicities seen in the increase in serum enzyme levels were depressed when the extract prepared from M. anka was given 1 and 15 h before the toxic insultant. Liver microsomal GST activity, which is known to be activated by oxidative stress, was increased by GalN or GaIN plus LPS treatment and the increase was also inhibited by pretreatment with the extract. Pathomorphological changes in the liver caused by GalN treatment also were prevented by the mold extract. These results indicate that the extract of M. anka has radical scavenging action and ameliorates chemically induced hepatotoxicity.

Animals↗
PubMed1999

Coronary artery disease and endothelial nitric oxide synthase and angiotensin-converting enzyme gene polymorphisms.

Nitric oxide (NO) inhibits platelet aggregation, proliferation of vascular smooth muscle cells, and leukocyte adhesion to endothelial cells. Thus, genetic variation in or near NO synthase may be involved in the pathogenesis of coronary artery disease (CAD). We investigated the association between CAD and endothelial constitutive NO synthase (ecNOS) and angiotensin-converting enzyme (ACE) gene polymorphisms by polymerase chain reaction analysis. These genotypes were examined in consecutive patients with CAD (n = 40) and control subjects (n = 34). The frequency of ecNOS genotypes in the CAD group (4a/a + 4a/b: 48%; 4bb: 52%) did not differ from that in the control group (4a/a + 4a/b: 29%; 4bb: 71%). The allele frequencies of ecNOS4a and ecNOS4b also did not differ between the two groups. On the other hand, the frequency of the ACE DD genotype in the CAD group (DD: 45%; ID: 35%; II: 20%) was significantly higher than that in the control group (DD: 21%; ID: 35%; II: 44%). The frequency of the D allele in patients with CAD (0.63) was also significantly higher than in controls (0.38). Combined analysis showed that the frequency of the ecNOS genotypes in ACE DD genotype subjects (4a/a + 4a/b: 39%; 4b/b: 61%) in the CAD group was not significantly different from that in the control group (4a/a + 4a/b: 29%; 4b/b: 71%). The ACE genotype might be a predictor of CAD, while the ecNOS genotype appeared to confer no appreciable increase in the risk of CAD.

Case-Control Studies↗
PubMed1999

Sequential MR studies of cervical cord injury: correlation with neurological damage and clinical outcome.

OBJECTIVE: To determine which images provide the most useful information and the best time to perform prognostic MRI. DESIGN: The severity of neurological complications was assessed using the ASIA impairment scale. MRI was first performed within 48 h of injury, and was subsequently performed after 2-3 weeks, 3 months, 6 months, and 1 year. SETTING: Inpatient SCI medicine unit. SUBJECTS: Seventy-five patients with acute traumatic cervical spinal cord injury (9 women and 66 men) aged from 19-89 years (mean: 54.7 years). RESULTS: Four characteristic patterns of signal changes were observed on MRI. These patterns correlated well with the severity of spinal cord damage and the clinical outcome. CONCLUSION: T2-weighted images provided the most useful information, and the best times for prognostic imaging were at the time of injury and 2-3 weeks later.

Adult↗
PubMed1999

Factors influencing survival of patients undergoing hepatectomy for colorectal metastases.

BACKGROUND: The extent of surgical margin is still a matter of controversy with regard to outcome after liver resection for metastatic disease. The aim of this study was to clarify the significant prognostic factors after hepatectomy for colorectal metastases, with special reference to the surgical margin. METHODS: Ninety-six patients who underwent initial hepatic resection for liver metastases from colorectal cancer between 1992 and 1994 were studied. RESULTS: Overall 1-, 3- and 5-year survival rates were 94, 61 and 51 per cent respectively. All of the independent factors associated with poor prognosis after hepatic resection were tumour-related factors, such as the number of tumours (four or more), presence of portal vein invasion, hepatic vein invasion and absence of a fibrous pseudocapsule. A positive resection margin was not an independent prognostic factor, because of its strong relationship with the number of tumours resected. CONCLUSION: A generous surgical margin is not essential for curative hepatic resection, although positive surgical margins should be avoided. New potential risk factors which affect survival, such as the presence of portal vein or hepatic vein invasion and the absence of a pseudocapsule, may be helpful for defining the indications for postoperative adjuvant treatment.

Adult↗
PubMed1999

A novel member of murine Polycomb-group proteins, Sex comb on midleg homolog protein, is highly conserved, and interacts with RAE28/mph1 in vitro.

The Polycomb group of (PcG) genes were originally described in Drosophila, but many PcG genes have mammalian homologs. Genetic studies in flies and mice show that mutations in PcG genes cause posterior transformations caused by failure to maintain repression of homeotic loci, suggesting that PcG proteins have conserved functions. The Drosophila gene Sex comb on midleg (Scm) encodes an unusual PcG protein that shares motifs with the PcG protein polyhomeotic, and with a Drosophila tumor suppressor, lethal(3)malignant brain tumor (l(3)mbt). Expressed sequence tag (EST) databases were searched to recover putative mammalian Scm homologs, which were used to screen murine cDNA libraries. The recovered cDNA encodes two mbt repeats and the SPM domain that characterize Scm, but lacks the cysteine clusters and the serine/threonine-rich region found at the amino terminus of Scm. Accordingly, we have named the gene Sex comb on midleg homolog 1 (Scmh1). Like their Drosophila counterparts, Scmh1 and the mammalian polyhomeotic homolog RAE28/mph1 interact in vitro via their SPM domains. We analyzed the expression of Scmh1 and rae28/mph1 using northern analysis of embryos and adult tissues, and in situ hybridization to embryos. The expression of Scmh1 and rae28/mph1 is well correlated in most tissues of embryos. However, in adults, Scmh1 expression was detected in most tissues, whereas mph1/rae28 expression was restricted to the gonads. Scmh1 is strongly induced by retinoic acid in F9 and P19 embryonal carcinoma cells. Scmh1 maps to 4D1-D2.1 in mice. These data suggest that Scmh1 will have an important role in regulation of homeotic genes in embryogenesis and that the interaction with RAE28/mph1 is important in vivo.

Amino Acid Sequence↗