PubMed Health⌕ Search

Biomedical subjects

Hiroyuki Abe

Publications and source records attributed to Hiroyuki Abe.

72 records · Page 4Linked to original sources
PubMed2003

An efficient method to prepare T cell receptor gene-transduced cytotoxic T lymphocytes type 1 applicable to tumor gene cell-therapy.

Genes encoding 2C T cell receptor (TCR) alpha, beta chains from H-2(b)-restricted L(d)-specific CD8(+) cells were successfully transduced into polyclonally activated CD8(+) cells by retroviral modification to generate antigen-specific cytotoxic T lymphocytes (CTL). Antigen-nonspecific CD8(+) T cells polyclonally expanded in the presence of interleukin (IL)-2, Th1 cytokines (interferon (IFN)-gamma and IL-12) and anti-IL-4 monoclonal antibody showed neither cytokine production nor cytotoxicity in response to L(d)-expressing P815 tumor cells. However, 2C-TCR gene-modified CD8(+) T cells exhibited both IFN-gamma production and cytotoxicity in response to P815 tumor cells. The antitumor activity of TCR gene-modified Tc1 cells was also demonstrated in vivo by Winn's assay. Thus, we have developed an efficient method to induce TCR gene-modified antigen-specific Tc1 cells that exhibit antitumor activity both in vitro and in vivo.

Animals↗
PubMed2003

Quantitative computerized analysis of diffuse lung disease in high-resolution computed tomography.

An automated computerized scheme has been developed for the detection and characterization of diffuse lung diseases on high-resolution computed tomography (HRCT) images. Our database consisted of 315 HRCT images selected from 105 patients, which included normal and abnormal slices related to six different patterns, i.e., ground-glass opacities, reticular and linear opacities, nodular opacities, honeycombing, emphysematous change, and consolidation. The areas that included specific diffuse patterns in 315 HRCT images were marked by three radiologists independently on the CRT monitor in the same manner as they commonly describe in their radiologic reports. The areas with a specific pattern, which three radiologists marked independently and consistently as the same patterns, were used as "gold standard" for specific abnormal opacities in this study. The lungs were first segmented from the background in each slice by use of a morphological filter and a thresholding technique, and then divided into many contiguous regions of interest (ROIs) with a 32x32 matrix. Six physical measures which were determined in each ROI included the mean and the standard deviation of the CT value, air density components, nodular components, line components, and multilocular components. Artificial neural networks (ANNs) were employed for distinguishing between seven different patterns which included normals and six patterns associated with diffuse lung disease. The sensitivity of this computerized method for a detection of the six abnormal patterns in each ROI was 99.2% (122/123) for ground-glass opacities, 100% (15/15) for reticular and linear opacities, 88.0% (132/150) for nodular opacities, 100% (98/98) for honeycombing, 95.8% (369/385) for emphysematous change, and 100% (43/43) for consolidation. The specificity in detecting a normal ROI was 88.1% (940/1067). This computerized method may be useful in assisting radiologists in their assessment of diffuse lung disease in HRCT images.

Algorithms↗
PubMed2003

Computer-aided diagnosis to distinguish benign from malignant solitary pulmonary nodules on radiographs: ROC analysis of radiologists' performance--initial experience.

PURPOSE: To evaluate radiologists' performance for determining a distinction between benign and malignant pulmonary nodules on chest radiographs without and with use of a computer-aided diagnosis scheme. MATERIALS AND METHODS: Fifty-three chest radiographs that depicted 31 primary lung cancers and 22 benign nodules were used. The likelihood measure of malignancy for each nodule was determined by using an automated computerized scheme. Sixteen radiologists (nine attending radiologists and seven radiology residents) participated in an observer study in which cases were interpreted first without and then with use of the scheme. The radiologists' performance was evaluated with receiver operating characteristic analysis. RESULTS: The mean area under the best-fit binormal receiver operating characteristic curve plotted in the unit square (Az) values of radiologists who interpreted images without and with the scheme were 0.743 and 0.817, respectively. The performance of radiologists was improved significantly when the scheme was used (P =.002). However, the performance (Az = 0.889) of the computer alone exceeded these results by a substantial margin. The average change in radiologists' confidence level for interpretation without and with the scheme was highly correlated (r = 0.845) with the likelihood measure of malignancy, which was presented as computer output. CONCLUSION: This scheme for computer-aided diagnosis has the potential to improve the accuracy of radiologists' performance in the classification of benign and malignant solitary pulmonary nodules.

Diagnosis, Computer-Assisted↗
PubMed2003

Evaluation of bovine embryos produced in high performance serum-free media.

This review evaluates the quality of bovine embryos developed from in vitro-matured (IVM) and -fertilized (IVF) oocytes cultured in either serum-free or serum-containing media. Bovine embryos cultured in serum-supplemented medium contain numerous cytoplasmic lipid droplets and immature mitochondria compared to those cultured in serum-free medium. The accumulation of cytoplasmic lipids in embryos developed in serum-containing medium may be a result of incorporation of lipoproteins from the serum and may result in impaired function of mitochondria. The improved serum-free media (IVMD101 and IVD101) offer several advantages over culture in serum-containing medium, including increased rates of blastocyst formation and higher cell numbers. Additionally, the survival and hatching rates of embryos produced in serum-free media after post-thaw culture were superior to those of embryos produced in the serum-containing medium, suggesting that the abnormal accumulation of cytoplasmic lipids in embryos may have a negative effect on the sensitivity of embryos to chilling and freezing. These serum-free culture systems have proven to be beneficial for the production of good quality embryos from IVM-IVF bovine oocytes. Furthermore, recent studies have shown a correlation between mitochondrial function (oxygen consumption) and embryo quality. A new method using scanning electrochemical microscopy may be capable of assessing the viability and developmental potential of bovine embryos.

Animals↗
PubMed2002

Stimulation of the proliferation and differentiation of mouse pink-eyed dilution epidermal melanocytes by excess tyrosine in serum-free primary culture.

The epidermal cell suspensions of the neonatal dorsal skin derived from wild type mouse at the pink-eyed dilution (p) locus (black, C57BL/10JHir-P/P) and their congenic mutant mouse (pink-eyed dilution, C57BL/10JHir-p/p) were cultured with a serum-free melanocyte growth medium supplemented with additional L-tyrosine (Tyr) from initiation of the primary culture. L-Tyr inhibited the proliferation of P/Pmelanocytes in a dose-dependent manner, whereas L-Tyr stimulated the proliferation of p/p melanoblasts and melanocytes regardless of dose. On the other hand, L-Tyr stimulated (P/P) or induced (p/p) the differentiation of epidermal melanocytes in a dose-dependent manner. In both P/P and p/p melanoblasts and melanocytes cultured with 2.0 mM L-Tyr for 14 days, slight increases in contents of eumelanin marker, pyrrole-2,3,5-tricarboxylic acid (PTCA) and pheomelanin marker, aminohydroxyphenylalanine (AHP) were observed. The average number of total melanosomes (stages I, II, III, and IV) per P/P melanocyte was not changed by L-Tyr treatment, but the proportion of stage IV melanosomes in the total melanosomes was increased. On the contrary, in p/p melanoblasts and melanocytes L-Tyr increased dramatically the number of stage II, III, and IV melanosomes as well as the proportion of stage III melanosomes. Contents of PTCA and eumelanin precursor, 5,6-dihydroxyindole-2-carboxylic acid (DHICA) of cultured media in p/p melanocytes were much more greatly increased than in P/P melanocytes. However, contents of AHP and pheomelanin precursor, 5-S-cysteinyldopa (5-S-CD) of cultured media in p/p melanocytes were increased in a similar tendency to P/Pmelanocytes. These results suggest that p/p melanocytes in the primary culture are induced to synthesize eumelanin by excess L-Tyr, but difficult to accumulate them in melanosomes.

Animals↗
PubMed2002

Accumulation of cytoplasmic lipid droplets in bovine embryos and cryotolerance of embryos developed in different culture systems using serum-free or serum-containing media.

In this study, the quantitative fluctuation of cytoplasmic lipid droplets (LD) and cryotolerance were investigated in bovine embryos derived from in vitro-matured (IVM) and in vitro-fertilized (IVF) oocytes developed in different culture systems using serum-free or serum-containing media. The serum-free cultures were grown using IVMD101 medium in conjunction with bovine cumulus/granulosa cell (BCGC) cocultures or IVD101 medium without BCGC cocultures, and the serum-containing cultures were grown in the presence of BCGC cocultures using HPM199 medium supplemented with 5% calf serum (HPM199 + CS). Large numbers of sudanophilic LD were present in the cytoplasm of bovine embryos from 2-cell to hatched blastocyst stages, and the number and size differed between the embryos cultured in serum-free and serum-supplemented media. In the embryos cultured in HPM199 + CS, large (2-6 microm in diameter) sudanophilic LD increased significantly from the morula to the blastocyst stages. Throughout the embryonic development, the embryos developed in serum-free cultures with and without BCGC cocultures had numerous sudanophilic LD, but most of these droplets were small (<2 microm in diameter) and large LD were less numerous than those embryos cultured in HPM199 + CS. Giant LD (>6 microm in diameter) were frequently observed in morulae and blastocysts (including early blastocysts) developed in HPM199 + CS. Electron microscopic observations demonstrated that large LD were abundant in the cytoplasm of trophoblast and embryonic (inner cell mass) cells of blastocysts cultured in HPM199 + CS. These large LD were identified as osmophilic LD, an indication that these lipid inclusions contained a significant proportion of unsaturated lipids. Many elongated mitochondria were found in embryos developed in IVMD101 and IVD101 at the morula and early blastocyst stages, whereas many of the mitochondria in the morulae developed in HPM199 + CS were of an immature form such as spherical or ovoid shape. The survival and hatching rates of embryos (morulae, early blastocysts, and blastocysts) produced in serum-free media (both IVMD101 and IVD101) after post-thaw culture were superior to those of embryos produced in serum-containing medium. These results showed that bovine embryos cultured in serum-containing medium abnormally accumulated cytoplasmic lipids into their cytoplasm and the excess accumulation of cytoplasmic LD in embryos may affect the cryotolerance of embryos.

Animals↗
PubMed2002

Use of an artificial neural network to determine the diagnostic value of specific clinical and radiologic parameters in the diagnosis of interstitial lung disease on chest radiographs.

RATIONALE AND OBJECTIVES: The authors investigated the diagnostic value of each of multiple clinical parameters and radiologic findings in differentiating between various interstitial lung diseases by using an artificial neural network (ANN). MATERIALS AND METHODS: The ANN was designed to differentiate between 11 interstitial lung diseases. The authors employed 10 clinical parameters and 16 radiologic findings that were divided into three groups (location, general appearance, specific findings). The performance of the ANN was evaluated with receiver operating characteristic analysis with amodified round-robin (leave-one-out) method and 370 cases (150 actual cases, 110 published cases, and 110 hypothetical cases). The Az values of ANNs were evaluated with various combinations of 10 clinical parameters and 16 radiologic findings. RESULTS: The Az value obtained with the complete set of clinical parameters and radiologic findings was 0.947. The Az value obtained with the 10 clinical parameters alone was 0.900, which was greater than 0.843 obtained with the 16 radiologic findings alone. There were statistically significant differences among Az values for some diseases when certain clinical parameters were removed from the input. Omission of specific findings among the three groups of radiologic findings decreased the Az value significantly. CONCLUSION: These results appear to confirm that clinical parameters can be equally as or more important than radiologic findings in the diagnosis of interstitial lung diseases. Among radiologic findings, certain specific findings can be more important than the location or general appearance of abnormal findings.

Humans↗
PubMed2002

Cystosarcoma phyllodes of the seminal vesicle.

BACKGROUND: We report here an extremely rare case of cystosarcoma phyllodes of the seminal vesicle. METHODS: A 65-year-old man presented with urinary hesitancy, frequency and constipation. Clinical examinations including two needle biopsies were performed, and the patient had undergone open surgery. RESULTS: The final pathological diagnosis was cystosarcoma phyllodes of the seminal vesicle. Seven months after the operation, a chest X-ray showed lung metastasis, and the patient died 11 months after the operation. CONCLUSION: To our knowledge, only one case of cystosarcoma phyllodes of the seminal vesicle has been previously reported.

Aged↗
PubMed2002

Growth, antrum formation, and estradiol production of bovine preantral follicles cultured in a serum-free medium.

The objective of this study was to identify factors that would allow the establishment of a serum-free culture system that could support follicular and oocyte growth, antrum formation, and estradiol-17beta (E(2)) production in preantral follicles of bovine ovaries. Large preantral follicles (145-170 micro m in diameter) were microsurgically dissected from ovaries, embedded in 0.15% type I collagen gels, and maintained in a serum-free medium for up to 13 days at 38.5 degrees C in 5% CO(2) in air. This culture environment allowed most preantral follicles to maintain a three-dimensional structure with the presence of a thecal layer and basement membrane surrounding the granulosa cells throughout the entire culture period. The effects of insulin, insulin-like growth factor (IGF)-I, IGF-II, FSH, and LH on preantral follicle growth were investigated in serum-free medium. Follicular diameters were significantly larger in the presence of insulin, IGF-I, IGF-II, or FSH after 13 days in culture. Oocyte diameters were also significantly larger in the presence of all hormones tested. The single addition of insulin, IGF-I, or FSH induced antrum formation between Days 7 and 13 of culture. Insulin progressively induced E(2) secretion by follicles after antrum formation, but IGF-I and FSH had no apparent effect. FSH and LH caused an increase in oocyte diameter in the presence of insulin. The addition of three hormones (insulin, FSH, and LH) initiated antrum formation and E(2) production earlier than insulin-containing medium alone. Furthermore, maximal E(2) secretion was maintained steadily between 7 and 13 days in this culture condition. From these results, we have demonstrated that insulin, FSH, and LH play substantial roles in the growth and development of bovine large preantral follicles in a serum-free medium.

Animals↗
PubMed2002

Bicarbonate ion stimulates the expression of locus of enterocyte effacement-encoded genes in enterohemorrhagic Escherichia coli O157:H7.

Enterohemorrhagic Escherichia coli (EHEC) strains adhere to the intestinal mucosa and produce an attaching and effacing (A/E) lesion. Most of the genes required to produce A/E lesions are thought to be encoded by the 36-kb pathogenicity island termed the locus for enterocyte effacement (LEE). Although the mechanisms underlying the bacterial adherence, including the genes involved, are still poorly understood, the preferential adherence phenotype of EHEC is thought to depend on the nature of the genes and/or the response of these genes to changes in environmental conditions. To explore the environmental factors affecting EHEC adherence, we used an O157:H7 strain and investigated the optimal growth conditions for its adherence to Caco-2 cells. We observed that EHEC grown in Dulbecco's modified Eagle's medium (DMEM) adhered more efficiently to Caco-2 cells than EHEC grown in Luria-Bertani (LB) broth. Among the components of DMEM, only NaHCO(3) was found to remarkably stimulate bacterial adherence. When bacteria were grown in LB broth containing NaHCO(3), the production of intimin, Tir, EspA, and EspB was greatly enhanced compared with the production in LB broth. Indeed, the transcription of ler required for LEE-encoded gene expression was promoted in response to the concentration of NaHCO(3) in LB broth. Since the concentration of NaHCO(3) in the lower intestinal tract has been shown to be relatively high compared with that in the upper small intestine, our results may imply that NaHCO(3) is an important signaling factor for promoting colonization of EHEC in the lower intestinal tract in humans.

Bacterial Adhesion↗
PubMed2002

Lung cancers missed at low-dose helical CT screening in a general population: comparison of clinical, histopathologic, and imaging findings.

PURPOSE: To compare clinical, histopathologic, and imaging features of lung cancers missed at low-radiation-dose helical computed tomography (CT). MATERIALS AND METHODS: Eighty-three primary lung cancers were found during an annual low-dose CT screening program and confirmed histopathologically at either surgery or biopsy. Thirty-two of these lung cancers were missed on 39 CT scans: on 23 scans owing to detection errors and on 16 owing to interpretation errors. The clinical characteristics, CT features, and histopathologic findings of these missed lung cancers were correlated. RESULTS: All missed cancers were intrapulmonary, and 28 (88%) were stage IA. All 20 detection errors occurred in cases of adenocarcinoma, 17 (85%) of which were well-differentiated tumors and 11 (55%) of which were in nonsmoking women. The mean size of cancers missed owing to detection error, 9.8 mm, was smaller than that of cancers missed owing to interpretation error, 15.9 mm (P <.001). In the detection error group, the percentages of nodules with ground-glass opacity (91%) or judged to be subtle (91%) were greater than those of nodules in the interpretation error group (38% and 25%, respectively) (P <.001). In the detection error group, 83% (19/23) of cancers were overlapped with, obscured by, or similar in appearance to normal structures such as pulmonary vessels. On 14 of the 16 CT scans with which there were interpretation errors, the CT findings mimicked benign disease, and the patients also had underlying lung disease, such as tuberculosis, emphysema, or lung fibrosis. CONCLUSION: The lung cancers missed at low-dose CT screening in this series generally were very subtle and appeared as small faint nodules, overlapping normal structures, or opacities in a complex background of other disease.

Adenocarcinoma↗
PubMed2002

Serum leptin levels during the periparturient period in cows.

Serum leptin concentrations were measured in antenatal and postnatal cows housed at two different locations. The mean serum leptin concentration was 9.2 +/- 0.6 ng/m l (n=22) in one group, and was slightly lower in the other (7.4 +/- 0.4 ng/ml, n=54), probably because of the different nutritional conditions between the two groups. There was no consistent variation in relation to the menstrual cycle and the periparturient period in both groups. Moreover, serum leptin concentrations during the periparturient period were independent of the number of delivery and the incidence of mastitis and milk fever. These results are quite different from those in rodents and human, suggesting the different regulatory mechanism of circulating leptin concentration in cows.

Animal Nutritional Physiological Phenomena↗
PubMed2002

[Development of an image processing scheme for chest radiographs using a dot printer].

The performance of dot printers has recently been improved. Images output by dot printers can provide simple, economical medical reference images if important diagnostic information is not lost. We developed an image processing scheme for chest radiographs that employed a dot printer. We used two types of pixel value conversions, a nonlinear pixel value correction using a lookup table and a linear pixel value conversion using histogram analysis. The density distribution of chest radiographs was analyzed and classified into high-density and low-density images. The two types of pixel value conversions were used depending on the density of chest radiographs. Converted pixel value had density characteristics that were adapted to the output image of the dot printer, and thus the density distributions of the lungs of radiographs became comparable. In addition, an adaptive unsharp masking technique with processing parameters optimized for each of the lungs and mediastinum was applied. An ROC study for the detection of lung nodules was carried out to evaluate the performance of dot printer images. The area under the ROC curve (A(z)) for dot printer images was 0.816, while sensitivity and specificity were 77.6% and 75.2%, respectively. The performance indicated the usefulness of our image processing scheme.

Humans↗
PubMed2002

[Expression of Fas and induction of apoptosis by anti-Fas monoclonal antibody in human bile duct carcinoma cells, and enhancement of induction of apoptosis by IFN-gamma].

We investigated the expression of Fas, the induction of apoptosis by anti-Fas monoclonal antibody CH-11, and the effect of IFN-gamma on the induction of apoptosis in human bile duct carcinoma cells HuCCT1 and HuH28. Fas was expressed in 21.7% and 30.9% of HuCCT1 and HuH28 cells, respectively. Pretreatment with IFN-gamma increased the Fas expression by 17.6% in HuCCT1 cells. However, IFN-gamma did not affect the expression of Fas in HuH28 cells. In HuCCT1 and HuH28 cells treated with CH-11, the peak corresponding to that of positive control cells was detected with the TUNEL method by FCM. The condensation and fragmentation of the nucleus, and the apoptotic body were observed as morphological changes specific to apoptosis. CH-11 dose-dependently reduced HuCCT1 and HuH28 cell counts by up to 16.4% and 71.7%, respectively on day 3. Interferon-gamma attenuated the reduction of HuCCT1 cell counts by 12.8% on day 3. However, IFN-gamma had no effect on HuH28 cell counts. These results suggest that Fas was expressed, apoptosis was induced by CH-11 and the induction of apoptosis was enhanced by IFN-gamma in human bile duct carcinoma cells.

Antibodies, Monoclonal↗
PubMedDate not supplied

A case of lipomatous hypertrophy of the interatrial septum detected via transthoracic 2-dimensional echocardiography.

A 71-year-old woman underwent echocardiography for the evaluation of hypertensive heart disease. A 2-dimensional echocardiogram revealed an abnormal mass that protruded into the left atrium from the atrial septal side of the left atrial wall. Microscopic examination of the surgical specimen disclosed a mixture of normal-appearing fat, vesicular fat, and hypertrophied myocytes, and degenerated cardiac tissue with foci of necrotic fat tissue, consistent with lipomatous hypertrophy. Although lipomatous hypertrophy of the interatrial septum is rare, this little-known entity should be included in the differential consideration of the left atrial mass detected via echocardiographic examination, particularly in both obese and elderly patients.

Aged↗
PubMedDate not supplied

Computer-aided diagnosis in chest radiography: results of large-scale observer tests at the 1996-2001 RSNA scientific assemblies.

Since 1996, computer-aided diagnosis (CAD) schemes have been presented as interactive demonstrations on computer workstations at each scientific assembly of the Radiological Society of North America. The schemes involved (a) detection of pulmonary nodules, (b) temporal subtraction, (c) detection of interstitial lung disease, (d) differential diagnosis of interstitial lung disease, and (e) distinction between benign and malignant pulmonary nodules on chest radiographs. Large-scale observer tests were carried out to examine how radiologists can benefit from CAD systems. Observer performance was evaluated by analysis of receiver operating characteristic (ROC) curves. The statistical significance of the difference between the areas under the ROC curves without and with CAD was analyzed with the Student t test. In all of the tests, the diagnostic accuracy of the radiologists in total improved significantly when CAD was used. This result provides additional evidence that CAD has the potential to improve the performance of radiologists in their decision-making process in interpreting chest radiographs.

Diagnosis, Computer-Assisted↗
PubMedDate not supplied

Effects of PSK on T and dendritic cells differentiation in gastric or colorectal cancer patients.

BACKGROUND: Vaccine therapy targeting tumor antigens recognized by cytotoxic T cells (CTL) has been tried extensively. However, in a cancer-bearing state, the Th1/Th2 balance shifts to Th2 dominance, and this has been the obstacle to vaccine therapy to induce the CTL. DC1/DC2 subsets have also been reported to control the differentiation of Th subsets. The key to tumor immunotherapy is how to activate the DC1-Th1 lineage. PATIENTS AND METHODS: Six normal adults and 14 patients with gastric or colorectal cancers, who gave informed consent, were studied. The Th1/Th2 and DC1/DC2 ratios were determined by FACS. IL-12 and IL-10 production from PBMC were measured by ELISA. RESULTS: The Th1/Th2 and DC1/DC2 ratios were all significantly lower in the patients with gastric or colorectal cancers compared to normal adults. After protein-bound polysaccharide K (PSK) therapy in cancer patients, the Th1/Th2 balance shifted to Th1 dominance and the DC1/DC2 balance to DC1 dominance. IL-10 production was significantly decreased by PSK therapy. CONCLUSION: In the cancer-bearing state, the Th1/Th2 and DC/1/DC2 balance becomes Th2- and DC2-dominant. PSK therapy results in a shift of the Th1/Th2 and DC1/DC2 balance towards Th1 and DC1 dominance. We plan to examine whether combining dendritic cells (DC) vaccination therapy with oral PSK enhances the induction of T cell and DC differentiation in cancer patients.

Adult↗