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Biomedical subjects

K Itoh

Publications and source records attributed to K Itoh.

At least 397 records · Page 22Linked to original sources
PubMed1999

Tumor staging of pancreatic adenocarcinoma using early- and late-phase helical CT.

OBJECTIVE: We compared early-phase CT with late-phase CT in the evaluation of pancreatic adenocarcinoma. MATERIALS AND METHODS: Both early- and late-phase CT images of 25 pancreatic adenocarcinomas were compared with surgical-pathologic findings. We evaluated tumor detectability, tumor size, and local tumor invasion. RESULTS: Tumor detectability was 96% on early-phase CT imaging and 64% on late-phase CT imaging (p < .01). Sensitivity for anterior serosal invasion, retroperitoneal invasion, and arterial invasion on early-phase CT exceeded sensitivity on late-phase CT (p < .05). However, specificity for all factors on early-phase CT was less than or equal to specificity on late-phase CT. The grade of local tumor invasion on early-phase CT achieved better agreement with the surgical-pathologic results than did late-phase CT, especially for tumor size and retroperitoneal invasion. CONCLUSION: Early-phase CT was better than late-phase CT in revealing tumors, tumor size, and retroperitoneal invasion.

Adenocarcinoma↗
PubMed1999

Detection of hepatocellular carcinoma: comparison of low- and high-spatial-resolution dynamic MR images.

OBJECTIVE: The purpose of our study was to compare the diagnostic performance of low- and high-spatial-resolution gadolinium chelate-enhanced triphasic dynamic gradient-recalled echo (GRE) MR images in the detection of hepatocellular carcinoma. MATERIALS AND METHODS: Triphasic dynamic MR images obtained with low (256 x 128) and high (512 x 224) image matrices in 28 patients with 65 hepatocellular carcinomas (HCCs) were retrospectively analyzed. Image review was conducted on a segment-by-segment basis; a total of 215 liver segments, including 56 segments with tumor burden, were reviewed for the presence of HCC by three independent radiologists. Detectability was evaluated with relative sensitivity, specificity, and receiver operating characteristic (ROC) analysis. Image quality was evaluated with rank order analysis. RESULTS: Relative sensitivity was statistically significantly better with high-spatial-resolution images than with low-spatial-resolution images (p < .005). Relative specificity was statistically significantly better with low-spatial-resolution images than with high-spatial-resolution images (p < .001). Diagnostic accuracy determined by ROC curve analysis was marginally higher with high-spatial-resolution (area under ROC curve [Az] = .97) than with low-spatial-resolution (Az = .94, p < .09) images. Image quality was statistically significantly better with high-spatial-resolution images (p < .005). CONCLUSION: High-spatial-resolution dynamic GRE images were superior to low-spatial-resolution images in sensitivity of detecting HCC and in image quality. Triphasic dynamic GRE imaging in the screening and follow-up programs of patients with suspected HCC should be performed using high image matrices.

Adult↗
PubMed1999

Serum amyloid A1 alleles and plasma concentrations of serum amyloid A.

Serum amyloid A1 (SAA1), the predominant isotype of acute phase SAA in plasma and the predominant precursor of fibrillar deposits in reactive amyloidosis, is encoded by a gene, for which six allelic variants have been described. Recent studies proposed that the allele SAA1.3 was positively correlated with the development of reactive amyloidosis in Japanese. This study examined whether the plasma concentration of total SAA is influenced by specific SAA1 alleles. Two hundred and eighty healthy Japanese subjects were examined to determine the allelic distribution of SAA1 and SAA2 genes by the PCR-RFLP method, and to measure the total plasma SAA concentrations. SAA concentrations were significantly higher (p < 0.001) in subjects with the allele SAA1.5 than those without it, suggesting that SAA1.5 may have a distinctive feature in the process of synthesis or catabolism. Subjects with the allele SAA1.3 had lower SAA concentrations, though not statistically significant, than those with SAA1.1. There was not significant correlation of SAA2 alleles with SAA concentrations. These results are discussed in terms of amyloidogenicity.

Adult↗
PubMed1999

[The role of protein kinases and phosphatases in erythroid colony formation of elderly].

Using H-7, HA1001, FK506, cyclosporin A (CsA) and okadaic acid (OA), which are protein kinase and phosphatase inhibitors, we examined qualitative changes in hematopoietic precursor cells due to aging from the viewpoint of the role of protein kinases and phosphatases. Though H-7 and OA suppressed erythroid colony formation both in the elderly (age: 72-92, median: 86) and the young (age: 22-39, median: 29), no change due to aging was noted. HA1001 did not affect erythroid colony formation either in the elderly or the young. Erythroid colony formation was enhanced by FK506 and CsA in the young, however, erythroid colony formation was suppressed in the elderly. Similar examinations using cell fractions of non-T, non-macrophage, non-T + T, and CD34 positive cells were performed in both groups. Enhancement of erythroid colony formation in the young and suppression in the elderly by FK506 using unseparated MNC disappeared after removal of T cells. Enhancement of colony formation in the young and suppression of colony formation in the elderly were recovered when T cells were added again. The effects of FK506 and CsA on erythroid colony formation were thought to be the results of T cell inactivation, and the different sensitivity to FK506 and CsA in the elderly and young seemed to be the result of changes in the control mechanisms of hematopoiesis, such as the regulation of cytokine production by T cells, caused by aging.

Adult↗
PubMed1999

Near-infrared spectroscopy for dairy management: measurement of unhomogenized milk composition.

The potential of near-infrared spectroscopy to measure fat, total protein, and lactose contents of unhomogenized milk was studied for use in dairy management, as a new tool for on-line milk analysis in the process of milking. Influence of the spectral region, sample thickness, and spectral data treatment on the accuracy of determination was investigated. Transmittance spectra of 258 milk samples, collected at different stages of the milking process, were obtained with a spectrophotometer (NIRSystems 6500; FOSS-NIRSystems, Silver Spring, MD) in the wavelength range from 400 to 2500 nm with sample thicknesses of 1 mm, 4 mm, and 10 mm. The spectral region and sample thickness were found to be significant factors for milk fat and total protein determination but not the lactose determination. The best accuracy was obtained with the 1100 to 2400 nm region, 1-mm sample thickness, and the first derivative data transformation. For the spectral region from 700 to 1100 nm, close accuracy was obtained for fat with a 10-mm sample and for total protein with a 1-mm sample thickness. The sample thickness did not change significantly the accuracy of lactose determination. Different treatments of spectral data did not improve the calibrations for fat and protein. For the region from 700 to 1100 nm, where inexpensive on-line sensors could be used, the highest positive coefficients for fat were at 930, 968, 990, 1026, 1076, and 1092 nm; for lactose were at 734, 750, 786, 812, 908, 974, 982, and 1064 nm; and for total protein were at 776, 880, 902, 952, and 1034 nm.

Animals↗
PubMed1999

[The efficiency of magnetic resonance angiography (MRA) in the diagnosis and vertigo--prediction of vertebrobasilar insufficiency (VBI) and atherosclerosis].

Major causes of vertigo in patients who attend Otolaryngology clinics are peripheral vestibular disorders (PVD) and vertebrobasilar insufficiency (VBI). The purpose of this study was to see whether MRA findings can distinguish VBI from PVD to evaluate the efficiency of MRA in the diagnosis of vertigo. A total of 185 vertigo patients were examined by MRA with the 3D-Phase Contrast method. Three kinds of abnormalities of vessels, that is, (a) disappearance, (b) meandering, and (c) stoppage were found in MRA imaging. Therefore, we classified the MRA patterns into four types with two subtypes: type I; normal, type II-R; right hypoform of the vertebral artery, II-L; left hypoform of the vertebral artery, III; meandering form of the vertebrobasilar artery, IV-1; stoppage form of the basilar artery, IV-2; hypoform of the bilateral vertebral and basilar arteries. Diagnosis of the MRA patterns in each patient was camed out by a radiologist and neurosurgeon with the cooperation of an otolaryngologist. In 185 vertigo patients, 139 patients were clinically diagnosed as having PVD, 41 patients as having VBI, and 5 patients as having cerebellar and brainstem infarctions. The numbers of patients in MRA patterns I, II-R, II-L, III and IV were 140, 17, 12, 8, and 8 cases, respectively. The total number of VBI patients who demonstrated type III or IV patterns in MRA was significantly higher than that of type I, II-R and II-L (P < 0.005). All of the 8 cases with cerebellar and brainstem infarction belonged to type IV. Cerebral angiography was performed in nine cases with type II-R, II-L, III or IV-1, and the number of patients in each group was 3, 3, 1 and 2 cases, respectively. All of the type II-R and II-L cases revealed hypoform of the vertebral artery. The appearance of type III was restricted to type III's view was only meandering and type IV-1 showed severe stenotic changes in the union area. These data show that MRA findings in the diagnosis of vertigo patients are very effective in distinguishing VBI and cerebellar and brainstem infarction from PVD and that some pattern of MRA may correspond to atherosclerosis of the vertebrobasilar artery. We think MRA examination of vertigo patients is useful not only to assist in the diagnosis of the etiology but also to predict the stage of atherosclerosis in each patient.

Adolescent↗
PubMed1999

Effect of functional monomer in commercial dentin bonding agents use of an experimental dentin bonding system.

The objective of the present study was to understand the role of the functional monomers in dentin bonding agents of an experimental dentin bonding system by measuring the wall-to-wall contraction gap and tensile bond strength measurement. The efficacy of three commercial dentin bonding agents after using EDTA for conditioning and GM for priming was evaluated by measuring the contraction gap of the resin composite in a cylindrical dentin cavity, and by measuring the tensile bond strength of the composite to a flat dentin surface. The effect of the functional monomers was demonstrated by the contraction gap measurement alone. The value of the contraction gap was significantly different between the commercial dentin bonding agents and these agents without functional monomers (p < 0.05). It was concluded that the functional monomers were essential to obtaining the marginal integrity of the resin composite in the dentin cavities.

Acrylic Resins↗
PubMed1999

Effect of cavosurface angle on dentin cavity adaptation of resin composites.

The effect of the cavosurface angle of dentin cavities prepared in extracted human molars on the cavity adaptation of a resin composite was evaluated by measuring the gap width between the resin composite and the dentin cavity wall. Cavities with cavosurface angles of 90 degrees, 120 degrees, 135 degrees, or 150 degrees were pretreated with one of two commercial dentin bonding systems or an experimental dentin bonding system. The contraction gap width was measured at both the cavity margin and the section cavity using a light microscope. Complete cavity adaptation was obtained with pretreatment of the experimental groups regardless of the cavosurface angle. The contraction gap observed at the cavity margin was prevented with the two commercial dentin bonding systems when the cavosurface angle was increased to 150 degrees. A high correlation was observed between the contraction gap width and the proportion of the free surface to the adhesive surface of the resin composite restoration.

Composite Resins↗
PubMed1999

[Analysis of serum amyloid A1 alleles by PCR-RFLP].

Serum amyloid A1 (SAA1), the acute phase isotype of SAA protein family, preferentially forms amyloid fibrils in reactive amyloidosis. Three alleles (alpha, beta, gamma) have been identified in the SAA1 locus. A recent study suggested the association of SAA1 gamma with amyloidogenesis in Japanese patients with rheumatoid arthritis. In this study, PCR-RFLP method was developed for SAA1 allele analysis. The use of two restriction enzymes, Ban I and Bcl I, for SAA1-derived PCR products, clearly identified six SAA1 genotypes. The frequency of SAA1 alleles was determined in the 100 healthy subjects, and resulted in 33.0%, 30.5% and 36.5%, for alpha, beta and gamma, respectively.

Alleles↗
PubMed1999

[Atypical chronic myeloid leukemia presenting with trilineage dysplasia and IgG (lambda) type monoclonal gammopathy].

A 78-year-old man was diagnosed as leukocytosis in February 1994. Physical examination revealed marked hepatosplenomegaly. A peripheral blood examination disclosed 95,090/microliter leukocytes without hiatus leukemicus, 6.5 g/dl Hb, and 15.0 x 10(4)/microliter platelets. The neutrophil alkaline phosphatase score was 27, and serum VB12 was above 1,600pg/ml. IgG was identified as monoclonal immunoglobulin of type lambda. Bone marrow specimens demonstrated marked granulocytic hyperplasia. Neither the Philadelphia chromosome (Ph1) nor BCR gene rearrangement was detected; hence, the diagnosis of Ph1 (-) chronic myeloid leukemia (CML) was made. The patient was treated with hydroxyurea and low-dose VP-16 with no improvement, and died of pneumonia and sepsis in June 1995. This case was considered to be consistent with atypical CML (aCML) according to the FAB classification because monocytosis was not observed. It seems likely and interesting that the coexistent monoclonal gammopathy and aCML might have arisen from common abnormal hematopoietic stem cells.

Aged↗
PubMed1999

[A new universal gene replacement method for generating a desired mutant mouse].

Site-directed gene replacement has been accomplished using two steps of gene targeting, which is called universal gene replacement. The previously described universal gene replacement method with the "neo-tk" cassette exhibited a very low efficiency in the second "replacement" step. The neo-tk tagged allele obtained from the first step was never transmitted to offspring through the germ cells of chimeric mice. We therefore developed a new system using the Eco-gpt gene instead of the HSV-tk gene. With this system, gene replacement for the p53 gene was thus consistently accomplished and generated mutant mouse lines with site-directed mutations. Further, all manipulated alleles, including the neo-gpt tagged one, were successfully transmitted to offspring.

Animals↗
PubMed1999

[Development of a sensitive enzyme immunoassay for protein 1/Clara cell 10 kDa protein using monoclonal antibodies].

Protein 1 (P1)/Clara cell 10 kDa protein is a dimer of identical subunits of 70 amino acids. Designed to expand its clinical significance, a sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for P1 was developed using two monoclonal antibodies, which were recently generated and characterized in this laboratory. The precision, reproducibility and specificity of the assay were quite satisfactory. Species specificity was also satisfactory. The detection sensitivity was 5 ng/l; high enough to quantify P1 in several body fluids. P1 was distributed in the value of 13 to 25 micrograms/l, 153-4300 micrograms/l and 145-8600 micrograms/l, in serum, bronchoalveolar lavage fluids and seminal fluids, respectively.

Adult↗
PubMed1999

Nucleotide sequence of thymidine kinase gene of sequential acyclovir-resistant herpes simplex virus type 1 isolates recovered from a child with Wiskott-Aldrich syndrome: evidence for reactivation of acyclovir-resistant herpes simplex virus.

Recurrent acyclovir (ACV)-resistant (ACV-r) herpes simplex virus type 1 (HSV-1) infections occurred in a patient with Wiskott-Aldrich syndrome, an X-linked recessive immunodeficiency syndrome composed of three clinical characteristics of immunodeficiency, thrombocytopenia, and an eczematous dermatitis. The patient had severe and recurrent ACV-r herpes simplex and was treated with vidarabine in a satisfactory manner from 1993 to 1997. During the 4-year observation period, two ACV-sensitive (ACV-s) HSV-1 isolates and five ACV-r HSV-1 isolates were recovered. The nucleotide sequence of the thymidine kinase (TK) gene from these sequential ACV-r isolates was compared with the ACV-s isolates. A single nucleotide deletion of cytosine (C) from homopolymer stretch of four C residues between nucleotide 1061 and 1064 of the open reading frame was found in all ACV-r isolates. No other differences were observed in the TK nucleotide sequence between ACV-s and ACV-r isolates. The TK nucleotide sequences of the two ACV-s isolates were identical to each other and those of the five ACV-r isolates were identical to one another. These results suggest that the ACV-r HSV-1 might have derived from the ACV-s strain in the patient body and that TK-associated ACV-r HSV-1 can reactivate from latency.

Acyclovir↗
PubMed1999

Effects of physical therapy on cytokines and two color analysis-lymphocyte subsets in patients with cerebrovascular diseases.

The effects of physical therapy on immunological parameters were evaluated in 12 patients (8 males and 4 females, 69.2 +/- 9.0 years) with cerebrovascular diseases in a stable situation two to three months after the onset of stroke who entered in our hospital between 1994 and 1997. After a two-month physical therapy program, the proportions of helper-inducer T (Thi) cells and suppressor-inducer T (Tsi) cells were increased significantly and that of cytotoxic T (Tc) cells was decreased, although those of HLA-DR+, suppressor T (Ts) and activated T (Tac) cells were not changed. The antibody dependent cellular cytotoxicity (ADCC) was significantly increased, although natural killer (NK) cell activity was not changed. The serum levels of interleukin-2 receptor was significantly increased but those of interleukin-2, interleukin-6 and interleukin-12 were not changed. The serum levels of interleukin-10, interleukin-12 and tumor necrosis factor-alpha were not detectable, while interleukin-1beta was decreased in 2 patients and interleukin-10 was increased in 2 patients. These findings suggest that daily physical exercise may activate the immune system possibly through the cytokine network in patients with cerebrovascular diseases (CVD).

Aged↗
PubMed1999

Clinical analysis of breathing exercise during immersion in 38 degrees C water for obstructive and constrictive pulmonary diseases.

Breathing exercises during immersion in 38 degrees C water were performed in 22 patients with bronchial asthma, pulmonary emphysema and constrictive pulmonary diseases. The patients entered a pool filled with 38 degrees C water to shoulder level. While standing, they breathed in deeply and breathed out slowly through the mouth into water while sinking the nose below the water level. This breathing method was repeated for 20 min. with a 5-min. rest out of water and this cycle was performed twice a day for two months. Respiratory function test and arterial blood gas analysis were examined before and after the two-month exercise program. FEV1.0% was significantly increased in patients with asthma and emphysema (p = 0.042 and 0.032, respectively) but did not change in patients with constrictive pulmonary diseases. %FVC, PF and Vmf25 did not change in any of the diseases. PaO2 was significantly increased in emphysematous patients (p = 0.0002) and PaCO2 was significantly decreased in asthmatic and emphysematous patients (p = 0.034 and 0.046, respectively). These results suggest that our breathing exercise by immersion is useful in patients with asthma and emphysema but is less effective in patients with constrictive pulmonary diseases.

Aged↗
PubMed1999

[PGE1 and dopamine administration in a pediatric patient during hepatectomy].

A 2-year-old male underwent medial inferior hepatectomy for the treatment of metastatic tumors. Due to congenital hepatoblastoma, at 6-months of age, right lobectomy of his liver had been performed. To protect liver functions, PGE1 and dopamine were administered during the surgery. Although half of his circulating blood volume was lost, his perioperative hemodynamics was stable, with no development of postoperative liver dysfunction. PGE1 and dopamine may thus be beneficial in pediatric hepatectomy.

Alprostadil↗