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Biomedical subjects

K Okuda

Publications and source records attributed to K Okuda.

At least 415 records · Page 23Linked to original sources
PubMed1994

A study of reservoir implantation--especially with saphenous vein graft catheterization.

Intra-arterial infusion chemotherapy is commonly used to treat hepatocellular carcinomas (HCC) and metastatic liver cancer after hepatectomy or in unresectable patients, and it has been adopted at Kurume University Hospital as a treatment for HCC. As complications of reservoir implantation have been encountered, the implantation procedure needs improvement. Procedures were compared in a study with 109 patients who were available for follow-up observation among 116 patients who underwent reservoir implantation. Fifty-six of the patients received intraoperative implantation through the gastroduodenal artery (GDA catheterization), 31 received external catheterization (EXT catheterization) and 22 received catheterization using a saphenous vein graft (SVG catheterization). The complication rates were 75.0%, 9.7% and 13.9% and the one-year patencies were 44.1%, 70.6% and 79.4%, respectively. GDA catheterization was no better than the other two procedures and it had a higher incidence of complications and a lower patency. SVG catheterization achieved good patency, although it had a little higher incidence of complications than external catheterization. It was presumed to be a procedure that would ensure reservoir implantation even in patients with a winding or variation of hepatic artery.

Catheters, Indwelling↗
PubMed1994

Expression of 25-hydroxyvitamin D3-24-hydroxylase mRNA in cultured human keratinocytes.

It is well documented that 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25[OH]2D3), the most active vitamin D metabolite, inhibits epidermal keratinocyte proliferation and promotes differentiation. 1 alpha,25(OH)2D3 can be produced in keratinocytes from 25-hydroxyvitamin D3 by the enzyme 25-hydroxyvitamin D3-1 alpha-hydroxylase (1-OHase). Hydroxylation of 1 alpha,25(OH)2D3 by 25-hydroxyvitamin D3-24-hydroxylase (24-OHase), the first step in the catabolic pathway of 1 alpha,25(OH)2D3 could significantly reduce the intracellular concentration of 1 alpha,25(OH)2D3. Therefore, the expression of 24-OHase could have a critical regulatory role in 1 alpha,25(OH)2D3-dependent gene expression. As a first step to examine this possibility, the steady state level of 24-OHase mRNA in cultured human keratinocytes (CHK) was investigated. 24-OHase mRNA was not detected in control CHK. 1 alpha,25(OH)2D3 caused a dose- and time-dependent increase in 24-OHase mRNA level. The highest accumulation of 24-OHase mRNA was observed in CHK treated with 0.1-1 microM 1 alpha,25(OH)2D3. The level of 24-OHase mRNA reached a plateau 12-24 hr after 1 alpha,25(OH)2D3 treatment. 1 beta,25-dihydroxyvitamin D3, the stereoisomer of 1 alpha,25(OH)2D3, failed to induce 24-OHase mRNA expression significantly. In addition to 24-OHase mRNA, a 1.0-kb mRNA hybridized strongly with both rat and human 24-OHase cDNA probes. The origin of this 1.0-kb message is unknown at present, however, it was regulated by 1 alpha,25(OH)2D3. These results demonstrate that 1 alpha,25(OH)2D3 up-regulates the expression of 24-OHase mRNA, and this may be an important first step in the initiation of catabolism of 1 alpha,25(OH)2D3 in human keratinocytes.

Calcitriol↗
PubMed1994

Lipopolysaccharides from various Capnocytophaga strains possess potent Limulus amoebocyte lysate clotting activity.

Lipopolysaccharides (LPSs) were extracted by the hot phenol-water method from three ATCC strains (C. sputigena ATCC 33612, C. ochracea ATCC 33596, and C. gingivalis ATCC 33624) and three clinical isolates (C. sputigena TE-1, C. ochracea ONO-26, and C. gingivalis M-12). Endospecy was used to determine the Limulus amoebocyte lysate clotting activities. The activities of LPSs from Capnocytophaga strains were stronger than those of Escherichia coli, with the exception of the LPS from C. gingivalis M-12. Except for the LPS from C. sputigena TE-1, the SDS-PAGE analyses of these preparations showed slow-migrating and repeating ladder bands similar to the LPSs of E. coli and Salmonella typhimurium (wild type) and included both the core-lipid A region and various lengths of O-antigen. The LPS from C. sputigena TE-1 possessed fast-migrating bands and did not have an O-side chain.

Capnocytophaga↗
PubMed1994

Efficacy of Listerine antiseptic against MRSA, Candida albicans and HIV.

The antiseptic activity of Listerine and Cool Mint Listerine against methicillin-resistant Staphylococcus aureus (MRSA), Candida albicans, human immuno deficiency virus (HIV) and oral bacteria was examined in this study. Exposure for 30 seconds to Listerine killed MRSA completely. Exposure for 30 seconds significantly decreased viable cells of C. albicans. More than 60% of HIV was inactivated by a 30 second exposure to 50% Listerine. Listerine exhibited a potent bactericidal effect against cariogenic and periodontopathic bacteria. Cool Mint Listerine had almost the same antiseptic effect against tested microorganisms. Listerine appears to be effective for killing etiologic microorganisms of opportunistic infection in the oral cavity.

Candida albicans↗
PubMed1994

Factor independence of human myeloid leukemia cell lines is associated with increased phosphorylation of the proto-oncogene Raf-1.

The proliferation of normal hematopoietic cells is strictly factor dependent, while leukemic cell lines and primary leukemic cells are frequently factor independent. Although autocrine growth stimulation of human leukemias is occasionally observed in vitro, it is possible that mutations of signal-transduction or cell-cycle control genes may also be important in the development of factor independence. We have previously shown that the proto-oncogene Raf-1, a 70-kd serine/threonine protein kinase, is rapidly phosphorylated and activated by hematopoietic growth factors such as granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), and Steel factor and is likely to be an important intermediate in mitogenic signal transduction pathways in hematopoietic cells. In an effort to better understand the possible role of abnormal signal transduction in the development of factor independence, we compared the state of phosphorylation and associated kinase activity of Raf-1 between a series of factor-dependent human and murine-myeloid normal cells or cell lines and a series of factor-independent myeloid cell lines. In factor-dependent myeloid cells (normal neutrophils; monocytes; and the cell lines MO7, 32Dc13, and FDC-P1), Raf-1 phosphorylation and associated kinase activity was strictly regulated by the supply of growth factor. In contrast, each of eight factor-independent leukemic cell lines examined, HL-60, KG-1, K562, U937, JOSK-S, JOSK-M, JOSK-K, and JOSK-I, expressed hyperphosphorylated Raf-1 with increased Raf-1 associated kinase activity in the absence of growth factor addition. To further explore the relationship of Raf-1 to factor-independent growth, factor-independent sublines were derived from two factor-dependent cell lines, MO7 and FDC-P1, by culture in CSF-deprived medium. Also, several factor-independent sublines were derived by transfection of a cDNA encoding p210BCR/ABL into three different cell lines: MO7, 32Dc13, and FDC-P1. In each case, the new sublines expressed constitutively hyperphosphorylated and activated Raf-1. The correlation of hyperphosphorylation of Raf-1 with factor independence was also observed with primary acute myeloblastic leukemia cells. The rate of "spontaneous" proliferation of primary acute myeloblastic leukemia (AML) cells in vitro correlated with the extent of Raf-1 phosphorylation. These results suggest that the evolution of myeloid leukemic cells to factor independence is associated with phosphorylation and activation of Raf-1, implicating Raf-1 and signal transduction pathways which activate RAf-1 in this process.

Bone Marrow↗
PubMed1994

[Noninvasive and simple method for the estimation of myocardial metabolic rate of glucose by PET and 18F-FDG].

To estimate regional myocardial metabolic rate of glucose (rMRGlu) with positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG), non invasive simple method has been investigated using dynamic PET imaging in 14 patients with ischemic heart disease. This imaging approach uses a blood time-activity curve (TAC) derived from a region of interest (ROI) drawn over dynamic PET images of the left ventricle (LV), left atrium (LA) and aorta. Patlak graphic analysis was used to estimate k1k3/(k2+k3) from serial plasma and myocardial radioactivities. FDG counts ratio between whole blood and plasma was relatively constant (0.91 +/- 0.02) both throughout the time and among different patients. Although TACs derived from dynamic PET images gradually increased at later phase due to spill over from the myocardium into the cavity, there were good agreements between the estimated K complex values obtained from arterial blood sampling and dynamic PET imaging (LV r = 0.95, LA r = 0.96, aorta r = 0.98). These results demonstrate the practical usefulness of a simplified and noninvasive method for the estimation of rMRGlu in humans by PET.

Aged↗
PubMed1994

[The study of continuous arterial infusion chemotherapy with 5-FU and CDDP in patients with hepatocellular carcinoma].

Between Feb. 1992 and March in 1994, 14 patients with hepatocellular carcinoma (7: recurrence, 7: unresectable) received continuous arterial infusion of 5-FU and CDDP via implanted reservoir. For the next five days, 10 mg/body of CDDP and 250 mg/body of 5-FU using arterial infusion were administered. It was discontinued for two days, as one course, and 4 courses were basally administered. The duration of the administration was 24 or 6 hours/day. Side effects consisted of nausea or loss of appetite for 7 (50%), suppression of bone marrow for 3 (21%), and they disappeared after the agents were discontinued. However, there were 3 patients with gastro-duodenal ulcer, so careful follow-up was necessary. The efficacy rate was 64% and two-year survival rate was 57% and thus this treatment seemed to be effective. Further study on the duration and dose of the administration is necessary to improve the therapeutic effect and QOL.

Aged↗
PubMed1994

Polyclonal B cell activation, endotoxin tolerance, and limulus tests of endotoxin preparations of some periodontopathogens.

Potencies of polyclonal B-cell activation in C3H/HeN mice of Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis endotoxins were 0.36, 0.13 and 0.04, taking Salmonella abortusequi as 1.0. F. nucleatum and P. gingivalis endotoxins showed positive reactions in C3H/HeJ mice. Most activities in C3H/HeN other than that of F. nucleatum were suppressed by polymyxin B. In C3H/HeJ mice, similar inhibitions were only 60% for P. gingivalis and hardly observed with F. nucleatum. The resistances to polymyxin B could be due to protein in the endotoxins. A promoting effect of T cells added to B cells was observed only in the activity of F. nucleatum endotoxin in C3H/HeJ mice; there was no influence in other groups. Test endotoxins had nearly the same ability to produce colony stimulating factor as did references and could not produce the factor in tolerant mice. The clinical significance of tolerance is discussed. Regression lines of endotoxin doses and limulus activities of test endotoxins and Salmonella were parallel, either in specific or non-specific tests. The lines of two test groups were also parallel; values obtained by two tests were very close. These data indicate that the test endotoxins did not contain (1-3)-beta-D-glucan and elicited qualitatively similar limulus reactions to that of the reference, despite their different chemical natures. In conclusion, these test preparations had an endotoxicity similar to that of the reference and contribute to produce periodontitis through polyclonal B cell activation.

Aggregatibacter actinomycetemcomitans↗
PubMed1994

B-cell mitogenicity and IL-1 beta production of lipopolysaccharides from various Capnocytophaga strains.

To evaluate the etiological roles of Capnocytophaga species in the pathogenesis of periodontal disease, we examined the immunological activities of lipopolysaccharides (LPSs) from various Capnocytophaga strains. All LPSs from various Capnocytophaga species were mitogenic for BALB/c mouse spleen cells, although the responses were lower than those to reference LPSs from Escherichia coli or Salmonella typhimurium. LPSs of C. sputigena strains had polyclonal B cell activation and adjuvant activity and were comparable to reference LPSs. All LPSs from Capnocytophaga strains activated the interleukin-1 beta production from human peripheral monocytes, although the inducing activities of Capnocytophaga LPSs were lower than those of reference LPSs. It appears that LPSs from various Capnocytophaga strains activate certain immunological responses from lymphocytes and monocytes which may be important in the development and pathogenesis of periodontal disease.

Alveolar Bone Loss↗
PubMed1994

A study of the subgingival microflora of HIV-seropositive and CD4 cell depleted children with hemophilia.

The cultivable subgingival bacterial flora from three HIV-seropositive and CD4 cell depleted children with hemophilia were examined in this study. The numbers of CD4 cells of the subjected children ranged from 4.9 to 16.3 per mm3 blood. Streptococcus species, including, beta-hemolytic streptococcus identified as Streptococcus mutans and Streptococcus sanguis, were predominant in the subgingival plaque samples. Actinomyces species were also frequently found. Gram-negative rods other than Capnocytophaga species were not common in these samples. It is possible that the subgingival microbial flora are influenced by the CD4 cell decrease with HIV infection.

Actinomyces↗
PubMed1994

Technetium-99m-pyrophosphate uptake as an indicator of myocardial injury without infarct.

UNLABELLED: Technetium-99m-pyrophosphate (PYP) is bound to calcium in necrotic myocardium and has been used clinically to evaluate myocardial infarction. Technetium-99m-PYP is also reported to accumulate in myocardium with unstable angina pectoris and it is speculated that severe ischemia with noninfarcted tissue may also increase uptake of 99mTc-PYP. In this paper, 99mTc-PYP uptake was determined in various models of myocardial ischemia of short duration to examine its applicability to the assessment of myocardial viability. METHODS: In 23 open-chest dogs under anesthesia, models of ischemia-reperfusion of the left anterior descending artery (LAD) subjected to ischemia for 10, 30 or 60 min were produced. Wall motion was examined by echocardiography and myocardial blood flow was calculated using colored microspheres. Technetium-99m-PYP was injected after each ischemic intervention and reperfusion. RESULTS: Technetium-99m-PYP showed 1.18 +/- 0.009 in the uptake ratio (ischemic area/normal area) following 10-min ischemia (11 dogs). The uptake ratio following 30-min ischemia (8 dogs) showed a significantly higher increase than that following 10-min ischemia (4.09 +/- 1.75; p < 0.05), permitting in vivo and ex vivo imaging. After 60-min ischemia resulting in infarction (4 dogs), 99mTc-PYP uptake of the ischemic area showed an uptake ten times that of the normal area (transmural: 12.2 +/- 2.9, epicardium: 7.5 +/- 1.9, endocardium: 16.8 +/- 4.1). CONCLUSIONS: These findings indicate that since 99mTc-PYP accumulates in injured myocardium, its concurrent use with blood flow imaging is useful for the assessment of severity of ischemia, injured area and myocardial viability.

Animals↗
PubMed1994

[Parvovirus B19-induced aplastic crisis in a patient with iron deficiency anemia].

A 38-year-old female was referred to Takaoka City Hospital for treatment of common-cold-like symptom and an episode of transient unconsciousness. Physical examination on admission revealed severe anemia and an ejection heart murmur. Complete blood count revealed microcytic hypochromic anemia (Hb 4.1 g/dl), leukocytopenia (2.600/microliters), thrombocytopenia (7.1 x 10(4)/microliters) and reticulocytopenia (17,000/microliters). The bone marrow cellularity was within normal limits. Cells in the erythroid series were decreased to 5% of total bone marrow nucleated cells with maturation arrest at the level of proerythroblasts. Giant proerythroblasts were observed in 0.2% of marrow nucleated cells. No stainable iron was seen. Both anti-parvovirus B19 IgM antibody and IgG antibody were positive in the serum and parvovirus B19 DNA was detected in the bone marrow cells by polymerase chain reaction. From these results, iron deficiency anemia complicated with pure red cell aplasia secondary to parvovirus B19-induced infection was diagnosed. The anemia gradually improved with administration of sodium ferrous citrate one month after admission. Parvovirus B19 has been reported to cause an aplastic crisis in the patients who has a rapid red cell turn over such as hemolytic anemia or acute blood loss. This report suggested that severe aplastic crisis is also induced in patients with iron deficiency anemia by parvovirus B19-induced infection and warns that careful observation is necessary for the follow up of patients with iron deficiency anemia.

Adult↗
PubMed1994

Myocardial tomography using technetium-99m-tetrofosmin to evaluate coronary artery disease.

UNLABELLED: To assess the clinical value of the 99mTc-labeled myocardial perfusion agent, 99mTc-tetrofosmin, the findings of stress and rest myocardial tomography were compared with those of stress and 3-hr delayed 201Tl tomography and coronary arteriography. METHODS: Twenty-five patients who had coronary arteriography were studied with both stress tetrofosmin and 201Tl tomography. RESULTS: The image quality of tetrofosmin was superior to that of 201Tl despite a shorter acquisition time. Both the tetrofosmin and 201Tl studies were quite sensitive to detect coronary artery disease (100% and 95%, respectively) (p = ns). The two studies showed similar sensitivity (75% and 73%) and specificity (80% and 77%, respectively) for the detection of significant (> or = 75% diameter) coronary artery stenosis. Stress distribution of tetrofosmin tended to be slightly higher than that of 201Tl (% uptake: 63.3% +/- 13.5% versus 60.4% +/- 12.2%, p = 0.0006; uptake score: 2.33 +/- 1.03 versus 2.22 +/- 1.07, p = 0.007), indicating less defect contrast in the former. A high concordant rate (89%) of the stress perfusion score was observed between the two radiopharmaceuticals. Reversible perfusion abnormalities were observed to be similar between stress-rest tetrofosmin and stress-delayed 201Tl studies. CONCLUSIONS: Stress tetrofosmin perfusion tomography is a valuable method to detect coronary artery disease and to assess tissue viability with accuracy similar to that of stress 201Tl tomography.

Aged↗
PubMed1994

Practical use of polymerase chain reaction for the diagnosis of steroid induced tuberculous lymphadenitis.

Tuberculous lymphadenitis that had developed after treatment with systemic prednisolone was diagnosed using the polymerase chain reaction (PCR) combined with dot-blot hybridization. Although the patient had no history of tuberculosis or suggestive radiological findings, a DNA fragment specific for Mycobacterium tuberculosis complex strains was amplified from a paraffin-embedded biopsy specimen of a cervical swelling, which was compatible with tuberculous lymphadenitis on haematoxylin-eosin (HE) and Ziehl-Neelsen staining. This report demonstrates the practical use of PCR for diagnosis of extra-pulmonary tuberculosis in a case difficult to diagnose conventionally.

Base Sequence↗
PubMed1994

[Comparative study of 201Tl-scintigraphic image and endomyocardial biopsy findings in patients with dilated cardiomyopathy].

201Tl-SPECT image was compared with the findings of endomyocardial biopsy in patients with dilated cardiomyopathies (DCM), and diagnostic value of 201Tl patchy pattern image for fibrosis with DCM was evaluated. Serial 22 patients diagnosed as DCM with endomyocardial biopsy findings were selected for this study (age: 50 +/- 17 y.o., Male/Female = 17/5). Patchy pattern of 201Tl-SPECT image was visually classified to 4 stage according to the severity of inhomogeneous defect, and pathologic findings of fibrosis was also classified into 4 according to the severity of fibrosis (0: none, 1: mild, 2: moderate, 3: severe). Ejection fraction calculated from left ventriculography and end-diastolic dimension by echocardiography were also compared with 201Tl-SPECT image. Out of 22 patients, 21 patients (95%) showed fibrosis, and 18 patients (82%) showed patchy pattern with 201Tl-SPECT. Severity of patchy pattern was not in good relation to that of fibrosis (r = 0.374). 201Tl image was not related to the function nor dimension. Four autopsy studies revealed a good relation of macroscopic severity, spatial distribution of fibrosis and inhomogeneous 201Tl-defect pattern before death. Patchy pattern of 201Tl-SPECT image will show the myocardial fibrosis in patients with DCM, and is independent of the function. 201Tl-SPECT may show more clinically useful findings of spatial distribution and severity of fibrosis with focal myocardial biopsy.

Adolescent↗