Biomedical subjects

Hiroyuki Abe

Publications and source records attributed to Hiroyuki Abe.

At least 55 records · Page 3Linked to original sources

PubMed2004

Potentiation of tumor eradication by adoptive immunotherapy with T-cell receptor gene-transduced T-helper type 1 cells.

Adoptive immunotherapy using antigen-specific T-helper type 1 (Th1) cells has been considered as a potential strategy for tumor immunotherapy. However, its application to tumor immunotherapy has been hampered by difficulties in expanding tumor-specific Th1 cells from tumor-bearing hosts. Here, we have developed an efficient protocol for preparing mouse antigen-specific Th1 cells from nonspecifically activated Th cells after retroviral transfer of T-cell receptor (TCR)-alpha and TCR-beta genes. We demonstrate that Th1 cells transduced with the TCR-alpha and -beta genes from the I-A(d)-restricted ovalbumin (OVA)(323-339)-specific T-cell clone DO11.10 produce IFN-gamma but not interleukin-4 in response to stimulation with OVA(323-339) peptides or A20 B lymphoma (A20-OVA) cells expressing OVA as a model tumor antigen. TCR-transduced Th1 cells also exhibited cytotoxicity against tumor cells in an antigen-specific manner. Moreover, adoptive transfer of TCR-transduced Th1 cells, but not mock-transduced Th1 cells, exhibited potent antitumor activity in vivo and, when combined with cyclophosphamide treatment, completely eradicated established tumor masses. Thus, TCR-transduced Th1 cells are a promising alternative for the development of effective adoptive immunotherapies.

Animals↗

PubMed2004

Automated computerized scheme for detection of unruptured intracranial aneurysms in three-dimensional magnetic resonance angiography.

RATIONALE AND OBJECTIVES: A computerized scheme for automated detection of unruptured intracranial aneurysms in magnetic resonance angiography was developed based on the use of a three-dimensional selective enhancement filter for dots (aneurysms). MATERIALS AND METHODS: Twenty-nine cases with 36 unruptured aneurysms (diameter, 3 to 26 mm; mean, 6.6 mm) and 31 non-aneurysm cases were used in this study. The isotropic 3-dimensional magnetic resonance angiography images with 400 x 400 x 128 voxels (voxel size, 0.5 mm) were processed by use of the selective enhancement filter. The initial candidates were identified by use of a multiple gray-level thresholding technique on the dot-enhanced images and a region-growing technique with monitoring some image features. All candidates were classified into four types of candidates according to the size and local structures based on the effective diameter and skeleton image of each candidate (ie, large candidates and three types of small candidates including short-branch type, single-vessel type, and bifurcation type). In each group, a number of false-positives were removed by use of different rules on localized image features related to gray levels and morphology. Linear discriminant analysis was used for further removal of false-positives. RESULTS: With this computer-aided diagnostic scheme, all of 36 aneurysms were correctly detected with 2.4 false-positives per patient based on a leave-one-out-by-patient test method. CONCLUSION: This computer-aided diagnostic system would be useful in assisting radiologists for the detection of intracranial aneurysms in magnetic resonance angiography.

False Positive Reactions↗

PubMed2004

Effect of temporal subtraction images on radiologists' detection of lung cancer on CT: results of the observer performance study with use of film computed tomography images.

RATIONALE AND OBJECTIVES: To evaluate the effect of temporal subtraction images on the radiologists' detection of early primary lung cancer in computed tomography (CT) scans. MATERIALS AND METHODS: Fourteen cases with primary lung cancer and 16 normal cases were used for this study from a database of low-dose CT images, which were obtained from a lung cancer screening program in Nagano, Japan. Images were obtained with a single-detector helical CT scanner using 10 mm collimation and 2:1 pitch. Each case had both previous and current CT scans. Temporal subtraction images were obtained by subtracting the warped previous images from the current images. Seven radiologists, including four attendings and three residents, provided their confidence levels for the presence or absence of lung cancers with use of film CT images without and with temporal subtraction images. Receiver operating characteristic analysis was used to compare their performance without and with temporal subtraction images. RESULTS: The mean Az values (area under the receiver operating characteristic curve) of seven observers without and with temporal subtraction images were 0.868 and 0.930, respectively. Diagnostic accuracy was significantly improved by using temporal subtraction images (P = .007). Temporal subtraction images were especially useful when a nodule was present near the pulmonary hilum, where radiologists tended to overlook it. CONCLUSION: The temporal subtraction technique can significantly improve the sensitivity and specificity for detection of lung cancer on CT scans.

Adult↗

PubMed2004

Artificial neural networks (ANNs) for differential diagnosis of interstitial lung disease: results of a simulation test with actual clinical cases.

RATIONALE AND OBJECTIVES: To evaluate the performance of an artificial neural network (ANN) scheme with use of consecutive clinical cases and its effect on radiologists with an observer test. MATERIALS AND METHODS: Artificial neural networks were designed to distinguish among 11 interstitial lung diseases on the basis of 26 inputs (16 radiologic findings, 10 clinical parameters). Chest radiographs of 96 consecutive cases with interstitial lung disease were used. Five radiologists independently rated their radiologic findings on the 96 chest radiographs. Based on their ratings of radiologic findings and clinical parameters obtained from the hospital information system, the output values indicating the likelihood of each of the 11 interstitial lung diseases were determined. Subsequently, 30 cases were selected from these 96 cases for an observer test. Five radiologists marked their confidence levels for diagnosis of 11 possible diseases in each case without and with ANN output. The performance of ANNs and radiologists was evaluated by receiver operating characteristic analysis based on their outputs and on confidence levels, respectively. RESULTS; The average Az value (area under the receiver operating characteristic curve) indicating ANN performance for the 96 consecutive cases was 0.85 +/- 0.03. The average Az values indicating radiologists' performance without and with ANN outputs were 0.81 +/- 0.11 and 0.87 +/- 0.06, respectively. The diagnostic accuracy was improved significantly when radiologists read chest radiographs with ANN outputs (P < .05). CONCLUSION: Artificial neural networks for differential diagnosis of interstitial lung disease may be useful in clinical situations, and radiologists may be able to utilize the ANN output to their advantage in the differential diagnosis of interstitial lung disease on chest radiographs.

Adult↗

PubMed2004

Use of mouse oocytes to evaluate the ability of human sperm to activate oocytes after failure of activation by intracytoplasmic sperm injection.

The objective of the present study was to investigate the nuclei of human sperms that failed to fertilize human oocytes after intracytoplasmic sperm injection (ICSI). The sperms were injected into mouse oocytes by a piezo-micromanipulator, and some of these oocytes were artificially activated with strontium chloride (SrCl2) after ICSI. The oocytes were fixed, stained, and subjected to chromosomal analysis. The survival rate of mouse oocytes injected with infertile human sperms was 92.0% (46/50), while that of the control mouse oocytes injected with fertile human sperms was 73.6% (81/110). The rate of two pronuclei (2PN) formation was 0 (0/46) by the infertile sperms and 81.5% (66/81) by the fertile ones, a significant difference (p < 0.01). Sperm chromosomes in non-activated oocytes were present as premature chromosome condensation (PCC). Artificial activation after ICSI increased the 2PN formation rate in the infertile group to 90.3% (28/31). The results of the present study suggest that infertile sperms have a low potential to spontaneously activate oocytes and to form pronuclei. Thus, artificial activation after ICSI may rescue oocytes fertilized with infertile human sperms that do not produce 2PN. The present study proved the usefulness of mouse oocytes as specimens in evaluating the oocyte-activating capacity of objective human sperms prior to ICSI treatment.

Animals↗

PubMed2004

Computer-aided diagnosis in chest radiology.

Chest radiography is still a useful examination in various situations, although CT has become a modality of choice as a diagnostic examination in many cases. Current computer-aided diagnosis (CAD) schemes for chest radiographs include nodule detection, interstitial disease detection, temporal subtraction, differential diagnosis of interstitial disease, and distinction between benign and malignant pulmonary nodules. All of these schemes are demonstrated as providing potentially useful tools for radiologists when the output of these schemes is used as a "second opinion." There are some commercially available products for these schemes and more are expected to be available in the near future. The current status of CAD for CT is also discussed briefly in this article.

Diagnosis, Computer-Assisted↗

PubMed2004

Radical perineal prostatectomy: development of a new surgical technique that divides the dorsal vein complex.

UNLABELLED: Standard radical perineal prostatectomy (RPP) was observed by laparoscope through a small suprapubic incision. To increase radicalness, we designed and investigated a new technique of RPP that decreased bleeding and shortened the operation time. SUBJECTS AND METHODS: Standard RPP was observed by laparoscope through a small suprapubic incision after lymph node dissection in 1 case. In 17 patients with localized prostatic cancer, the dorsal vein complex including the puboprostatic ligament was ligated and divided. The modified RPP was then performed, in which the prostate covered with the prostatic fascia in the anterior region was transected at the bladder neck. RESULTS: The results of the laparoscopic observation in standard RPP confirmed that the prostatic fascia in the prostatic anterior region had been left and the endopelvic fascia could be broken easily and safely by a clamp or finger from the perineum. With modified RPP the dorsal vein complex was easily ligated and divided without bleeding. The prostate could be transected at the bladder neck with the prostatic fascia attached to the anterior prostate as in RRP. The operation time was 140-190 min (mean 160 +/- 20.1) and the volume of bleeding was 150-512 ml (mean 224 +/- 60.4). CONCLUSION: This modified technique of RPP that transects the dorsal vein complex may replace the current technique of RPP.

Aged↗

PubMed2004

Cysteine suppresses oxidative stress-induced myofibrillar proteolysis in chick myotubes.

The effects of cysteine as an antioxidant nutrient on change in protein modification and myofibrillar proteolysis in chick myotubes by induction of oxidative stress by H(2)O(2) treatment were investigated. Myotubes were treated for 1 h with H(2)O(2) (1 mM). After this treatment, the H(2)O(2) was removed and the cells were cultured in cysteine (0.1 and 1 mM) containing serum-free medium for 24 h. Protein carbonyl content as an index of protein modification and N(tau)-methylhistidine release as an index of myofibrillar proteolysis were increased at 24 h after H(2)O(2) treatment, and the increment was reduced by cysteine. Calpain, proteasome and cathepsin (B+L and D) activities were increased at 24 h after H(2)O(2) treatment, and the increment was also reduced by cysteine. These results indicate that cysteine suppresses protein modification by oxidative stress, resulting in a decrease of protease acitivities, finally resulting in a decrease in myofibrillar proteolysis in chick myotubes.

Animals↗

PubMed2004

Radiologists' performance for differentiating benign from malignant lung nodules on high-resolution CT using computer-estimated likelihood of malignancy.

OBJECTIVE: The purpose of our study was to evaluate whether a computer-aided diagnosis (CAD) scheme can assist radiologists in distinguishing small benign from malignant lung nodules on high-resolution CT (HRCT). MATERIALS AND METHODS: We developed an automated computerized scheme for determining the likelihood of malignancy of lung nodules on multiple HRCT slices; the likelihood estimate was obtained from various objective features of the nodules using linear discriminant analysis. The data set used in this observer study consisted of 28 primary lung cancers (6-20 mm) and 28 benign nodules. Cancer cases included nodules with pure ground-glass opacity, mixed ground-glass opacity, and solid opacity. Benign nodules were selected by matching their size and pattern to the malignant nodules. Consecutive region-of-interest images for each nodule on HRCT were displayed for interpretation in stacked mode on a cathode ray tube monitor. The images were presented to 16 radiologists-first without and then with the computer output-who were asked to indicate their confidence level regarding the malignancy of a nodule. Performance was evaluated by receiver operating characteristic (ROC) analysis. RESULTS: The area under the ROC curve (Az value) of the CAD scheme alone was 0.831 for distinguishing benign from malignant nodules. The average Az value for radiologists was improved with the aid of the CAD scheme from 0.785 to 0.853 by a statistically significant level (p = 0.016). The radiologists' diagnostic performance with the CAD scheme was more accurate than that of the CAD scheme alone (p < 0.05) and also that of radiologists alone. CONCLUSION: CAD has the potential to improve radiologists' diagnostic accuracy in distinguishing small benign nodules from malignant ones on HRCT.

Diagnosis, Differential↗

PubMed2004

[Case report on intra-tumor injection therapy of dendritic cells in advanced gastric cancer].

Dendritic cells (DC) are powerful antigen-presenting cells, and have attracted attention in recent years from the viewpoint of DC vaccine therapy against cancer. However, the existence of an immunosuppressive state in cancer individuals leads to anergy and failure in cytotoxic T cell (CTL) induction and DC migration to the target organ. It has been reported that injected intra-tumor DCs are expected to work phagocytosis of the tumor as a localized effect. Consequently CTL induction in the tumor and the regional lymphnodes results in a systemic effect. In this study, intra-tumor DC injection therapy was performed by means of endoscopic ultrasonography (EUS) in 2 gastric cancer cases. As a result, tumor markers and ascites of one case were on the decrease. The results indicate this method can be useful in advanced cancer patients.

Dendritic Cells↗

PubMed2003

Gene structure and functional properties of mouse CRTH2, a prostaglandin D2 receptor.

CRTH2, the second receptor for prostaglandin D(2) (PGD(2)), is thought to play a role in allergic inflammations through the induction of chemotactic migration and/or the activation of Th2, eosinophils, and basophils, in humans. We previously identified the mouse CRTH2 homolog of human CRTH2 and suggest that animal models would provide a clear understanding on the precise function of CRTH2 in allergic disorders. To this end we have confirmed that mouse CRTH2 is similar in gene structure to human CRTH2 and revealed that mouse CRTH2 is predominantly expressed in the eosinophils derived from IL-5-transgenic mice. Moreover, mouse CRTH2 harbors the ability to bind PGD(2) with high affinity and intracellular Ca(2+) mobilization in a Gi-dependent manner and chemotactic responses in several transfected cell lines. The results demonstrated here indicate that mouse CRTH2 is the functional ortholog of human CRTH2 and paves the way for future analysis of the in vivo functions of CRTH2.

Animals↗

PubMed2003

Expression of Bcl-2 on leukocytes in prostatic fluid from patients with acute and chronic prostatitis.

In our continuing investigation to clarify the significance of leukocytosis and its prolongation in prostatic fluid (PF) from prostatitis patients, we investigated whether expression of the antiapoptotic gene Bcl-2 on leukocytes in prostatic fluid has any relation with prolonged leukocytosis in prostatitis. The subjects were eight patients with acute bacterial prostatitis (ABP) and eight with nonbacterial prostatitis (NBP) with a history of more than 2 years. Twelve micrograms of protein obtained from leukocytes in PF were subjected to Western blot analysis. Bcl-2 was expressed in seven of eight (87.5%) and six of eight (75.0%) patients with NBP and ABP, respectively. Quantitative density analysis of the Bcl-2 band did not show any statistically significant differences between patients with NBP and those with ABP. These results suggest that the expression of antiapoptotic Bcl-2 on leukocytes in PF is not a cause of leukocyte longevity in long-term prostatitis.

Acute Disease↗

PubMed2003

Frequency of alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in 19 clinical isolates of Neisseria gonorrhoeae in Tokyo in 2002.

The frequency of alterations in the GyrA subunit of DNA gyrase and the ParC subunit of topoisomerase IV in 19 clinical isolates of Neisseria gonorrhoeae obtained in Tokyo in 2002 was studied. The frequencies of GyrA and ParC mutations in these 19 isolates were 100% (19 of 19) and 84.2% (16 of 19), respectively, and these results were 1.48-fold (100%/67.6%) and 3.58-fold (84.2%/23.5%) higher, respectively, than the frequencies reported in 1998 in 68 isolates obtained in Fukuoka during the period from 1992 to 1996. Isolates with increasing numbers of mutations were more resistant not only to levofloxacin but also to other antibiotics. The 50% and 90% minimum inhibitory concentrations (MICs) to levofloxacin during the period from 1995 to 1996 were 0.063 and 1 micro g/ml, and they increased to 4 and 8 micro g/ml, respectively, in the present study. All 19 cases of gonoccocal urethritis in the present study were cured with a single intramuscular injection of 2 g spectinomycin.

Anti-Bacterial Agents↗

PubMed2003

Broiler chickens (Ross strain) lack insulin-responsive glucose transporter GLUT4 and have GLUT8 cDNA.

Identification of insulin-responsive glucose transporter proteins, GLUT4 and GLUT8, was attempted in chickens that characteristically are hyperglycemic and insulin resistant. Northern blot analysis using rat GLUT4 cDNA probe and RT-PCR using primers designed against the conserved regions in mammalian GLUT4 cDNA were not successful in identifying GLUT4 homologue(s) in various chicken tissues. Furthermore, GLUT4 homologues could not be detected in chicken tissues by genomic Southern blot analyses using a rat GLUT4 cDNA probe. These data, therefore, suggest that the GLUT4 homologous gene is deficient in chicken tissues. However, GLUT8, another insulin-responsive glucose transporter in the blastocyst, was identified with the aid of RACE (rapid amplification of cDNA ends) reactions in the chicken testis. Chicken GLUT8 was composed of 1449 bp with a coding region for a 482 amino acid protein. The deduced amino acid sequence was 58.8, 56.3, and 56.8% identical with human, rat, and mouse GLUT8, respectively. By RT-PCR, GLUT8 mRNA expressions were detected in chicken brain, kidney, adrenal, spleen, lung, testis, and pancreas; and barely detectable in skeletal muscle, liver, adipose tissue, and heart. Here we firstly report that GLUT8 was identified in chickens, while GLUT4, a major insulin-responsive transporter in mammals, is deficient in these animals. We propose the hypothesis that the hyperglycemia and insulin resistance observable in chickens is associated with their possible deficiency of GLUT4.

Amino Acid Sequence↗

PubMed2003

Low-dose computed tomography screening for lung cancer in a general population: characteristics of cancer in non-smokers versus smokers.

RATIONALE AND OBJECTIVES: To report the detection rate for lung cancers in computed tomography (CT) screening in Japanese adults, and to analyze differences in the appearance of the cancers in non-smokers versus smokers. MATERIALS AND METHODS: Subjects consisted of 7,847 Japanese adults who received low-dose CT screening at least once in a 3-year period. The detection rate of lung cancers and the correlation of imaging, clinical, and pathologic findings of cancers in non-smokers versus smokers were examined. RESULTS: The detection rate for lung cancer was 1.1% for both non-smokers (45 of 4,251) and smokers (39 of 3,596). The prevalence of well-differentiated adenocarcinomas was greater in non-smokers (88%; 22 of 25) than in smokers (29%; 4 of 14) (P < .001). The prevalence and incidence of pathologic stage IA disease were greater in non-smokers than in smokers (92%; [22 of 24] vs 58% [7 of 12], and 100% [19 of 19] vs 70% [14 of 20]) (both P < .05). The mean size of the tumors in the non-smokers (12.4 mm) was smaller than that in smokers (18.2 mm) (P < .001). The percentage of cancers categorized as pure or mixed ground-glass opacity (86%; 38 of 44) on CT was greater in non-smokers than in smokers (46%; 16 of 35) (P < .001). CONCLUSION: Most of the lung cancers in non-smokers were slow-growing adenocarcinomas appearing as faint ground-glass opacities on CT, whereas rapidly growing cancers appearing as solid nodules were more commonly seen in smokers.

Adenocarcinoma↗

PubMed2003

Effect of high sensitivity in a computerized scheme for detecting extremely subtle solitary pulmonary nodules in chest radiographs: observer performance study.

RATIONALES AND OBJECTIVES: This study investigated the effect of a high sensitivity in computer-aided diagnosis (CAD) for detecting lung nodules in chest radiographs when extremely subtle cases were presented to radiologists. MATERIAL AND METHODS: The chest radiographs used in this study consisted of 36 normal images and 54 abnormals containing solitary lung nodules, of which 25 were extremely subtle and 29 were very subtle. Receiver operating characteristic analysis for detecting lung nodules was performed without and with CAD. The levels of CAD output were simulated with a hypothetical ideal performance of 100% sensitivity, but with three or four false positives per image. Six radiologists participated in an observer study in which cases were interpreted first without and then with the use of CAD. RESULTS: The average A(z) values for radiologists without and with CAD were 0.682 and 0.808, respectively. The performance of radiologists was improved significantly when high sensitivity was used (P = .0003). However, the radiologists were not able to recognize some extremely subtle nodules (5 of 54 nodules by all radiologists), even with the correct CAD output; these nodules were then considered as non-actionable. None of 306 computer-false positives was incorrectly regarded as a nodule by all radiologists, but 63 false positives were incorrectly identified by one or more radiologists. CONCLUSION: The accuracy of radiologists in the detection of some extremely subtle solitary pulmonary nodules can be improved significantly when the sensitivity of a CAD scheme can be made to be at an extremely high level. However, all of the six radiologists failed to identify some nodules (about 10%), even with the correct output of the CAD.

Humans↗

PubMed2003

IcsB, secreted via the type III secretion system, is chaperoned by IpgA and required at the post-invasion stage of Shigella pathogenicity.

Shigella deliver a subset of effector proteins such as IpaA, IpaB and IpaC via the type III secretion system (TTSS) into host cells during the infection of colonic epithelial cells. Many bacterial effectors including some from Shigella require specific chaperones for protection from degradation and targeting to the TTSS. In this study, we have investigated the role of the icsB gene located upstream of the ipaBCDA operon in Shigella infection because the role of IcsB as a virulence factor remains unknown. Here, we found that the IcsB protein is secreted via the TTSS of Shigella in vitro and in vivo. We show that IpgA protein encoded by ipgA, the gene immediately downstream of icsB, serves as the chaperone required for the stabilization and secretion of IcsB. We have shown that IcsB binds to IpgA in bacterial cytosol and the binding site is in the middle of the IcsB protein. Intriguingly, although its significance in Shigella pathogenicity is as yet unclear, the icsB gene can be read-through into the ipgA gene to create a translational fusion protein. Furthermore, the contribution of IcsB to the pathogenicity of Shigella was demonstrated by plaque-forming assay and the Sereny test. The ability of the icsB mutant to form plaques was greatly reduced compared with that of the wild type in MDCK cell monolayers. Furthermore, when guinea pig eyes were infected with a non-polar icsB mutant, the bacteria failed to provoke keratoconjunctivitis. These results suggest that IcsB is secreted via the TTSS, chaperoned by IpgA, and required at the post-invasion stage of Shigella pathogenicity

Animals↗

PubMed2003

Polyangitis overlap syndrome: a fatal case combined with adult Henoch-Schönlein purpura and polyarteritis nodosa.

Henoch-Schönlein purpura (HSP) is a rather common disease characterized by systemic hypersensitivity vasculitis in the skin and other visceral organs. It has a favorable prognosis unless it is complicated by severe glomerular disease. We report a distinctive fatal case of systemic vasculitis combined with HSP and polyarteritis nodosa (PN) in a 56-year-old man who died of progressive renal failure one month after the onset of the disease. He complained of arthralgia, purpura of both lower extremities, nasal bleeding and tarry stool, and acute renal failure was noted at the time of admission to hospital. A skin biopsy from the purpura lesion exhibited leucocytoclastic vasculitis with IgA deposition, and HSP was considered. However, renal failure progressed rapidly and subsequently was complicated by acute myocardial infarction. Postmortem examination revealed PN type necrotizing vasculitis in the kidneys, heart and mesentery resulting in acute multiple infarctions of these organs. We think the current case was a polyangitis overlap syndrome. It is important to suspect the polyangitis overlap syndrome positively when progressive acute renal failure is seen in a patient with HSP and to begin appropriate therapy immediately.

Fatal Outcome↗