46 results on '"Akihiro Kojima"'
Search Results
2. Interleukin-19 Downregulates Interleukin-4-Induced Eotaxin Production in Human Nasal Fibroblasts
- Author
-
Norihiko Narita, Tetsuji Takabayashi, Akihiro Kojima, Masayuki Okamoto, Noboru Takahashi, Ryo Kawata, Masaaki Higashino, Hiroshi Takenaka, Shigeharu Fujieda, and Sawako Hyo
- Subjects
lcsh:Immunologic diseases. Allergy ,Eotaxin ,medicine.medical_treatment ,Down-Regulation ,Suppressor of Cytokine Signaling Proteins ,SOCS-1 ,Proinflammatory cytokine ,Suppressor of Cytokine Signaling 1 Protein ,medicine ,Humans ,Immunology and Allergy ,Gene Silencing ,Phosphorylation ,eotaxin ,Interleukin 4 ,STAT6 ,Gene knockdown ,Chemistry ,Interleukins ,Receptors, Interleukin ,General Medicine ,Fibroblasts ,human nasal fibroblast ,Nasal Mucosa ,Cytokine ,Gene Expression Regulation ,Chemokines, CC ,Immunology ,Interluekin-19 ,STAT protein ,Cancer research ,Interleukin 19 ,RNA Interference ,Interleukin-4 ,lcsh:RC581-607 ,STAT6 Transcription Factor - Abstract
Background Interleukin-19 (IL-19), a member of the IL-10 family, is characterized as the cytokine suppressing the release and function of several proinflammatory cytokines. For regulation of local reaction in allergic rhinitis (AR), IL-19 might play an especially important role. Methods We examined effects of IL-19 on IL-4-induced eotaxin production by human nasal fibroblasts. Early receptor-mediated events (expression of the suppressors of cytokine signaling (SOCS) and phosphorylation of signal transducer and activator of transcription 6 [STAT6]) by IL-19 was examined. Knockdown methods by RNAi were administered to investigate the involvement of those signal transductions. Results Pretreatment with IL-19 downregulates IL-4-induced eotaxin production, but not interferon-γ (IFN-γ)-induced RANTES. Pretreatment with IL-19 suppressed the IL-4-induced STAT6 phosphorylation. The IL-19 induced SOCS-1, but not SOCS-3 or SOCS-5. The SOCS-1 knockdown by RNAi diminished pretreatment with IL-19-induced down-regulation of eotaxin production. Conclusions These results suggest that IL-19 down-regulates IL-4-induced eotaxin production via SOCS-1 in human nasal fibroblasts. In non-hematopoietic cells in AR, IL-19 might be an immunosuppressive factor.
- Published
- 2011
- Full Text
- View/download PDF
3. Cough reflex induced by capsaicin inhalation in patients with dysphagia
- Author
-
Akihiro Kojima, Youko Osawa, Hiroshi Sunaga, Yoshimasa Imoto, and Shigeharu Fujieda
- Subjects
Male ,Larynx ,Cough reflex ,Central nervous system ,chemistry.chemical_compound ,Swallowing ,Predictive Value of Tests ,Reference Values ,Administration, Inhalation ,Reflex ,Sensation ,medicine ,Humans ,Aged ,Aged, 80 and over ,Dose-Response Relationship, Drug ,Inhalation ,business.industry ,General Medicine ,Middle Aged ,Dysphagia ,medicine.anatomical_structure ,Cough ,Otorhinolaryngology ,chemistry ,Capsaicin ,Anesthesia ,Female ,medicine.symptom ,Deglutition Disorders ,business - Abstract
We conclude that the capsaicin inhalation test is useful to directly assess cough reflex and sensation around the larynx, while it indirectly reflects central nervous system function.To understand the state of the cough reflex before patients with dysphagia start eating.We studied the cough reflex by the capsaicin inhalation test in 21 patients with dysphagia and 12 healthy persons without dysphagia.The control group showed a cough reflex at a capsaicin concentration of 2.61 μM (0.98-7.80), while patients with mild dysphagia did so at 7.28 μM (1.95-15.6), those with moderate dysphagia at 22.07 μM (15.6-62.5), and those with severe dysphagia at 71.75 μM (31.2-250). Control vs mild p0.01, control vs moderate p0.01, control vs severe p0.01, mild vs moderate p0.01, mild vs severe p0.01, moderate vs severe p0.05. There was a significant correlation between the grade of dysphagia and the threshold capsaicin concentration that provoked a cough reflex (ρ = -0.796, p0.001).
- Published
- 2010
- Full Text
- View/download PDF
4. Prevalence of Allergic Rhinitis and Sensitization to Common Aeroallergens in a Japanese Population
- Author
-
Akihiro Kojima, Yoko Osawa, Yusuke Nakamura, Shigeharu Fujieda, Masafumi Sakashita, Tomomitsu Hirota, Mayumi Tamari, Tatsuhiko Tsunoda, Yoshimasa Imoto, Dai Suzuki, Reiichiro Nakamichi, Michishige Harada, Masayuki Okamoto, and Seita Kubo
- Subjects
Adult ,Male ,medicine.medical_specialty ,Allergy ,Rhinitis, Allergic, Perennial ,Immunology ,Prevalence ,medicine.disease_cause ,Immunoglobulin E ,Age Distribution ,Allergen ,Asian People ,Japan ,Epidemiology ,medicine ,Mite ,Animals ,Humans ,Immunology and Allergy ,Cedrus ,Sensitization ,Mites ,biology ,business.industry ,Rhinitis, Allergic, Seasonal ,Aeroallergen ,General Medicine ,Allergens ,Middle Aged ,biology.organism_classification ,medicine.disease ,medicine.anatomical_structure ,biology.protein ,Female ,business - Abstract
Background: Allergic rhinitis (AR) is recognized as a major health problem worldwide, and its prevalence depends on the age range of the subjects. The aims of this study were to determine the current prevalence of AR, effects of age on the prevalence of IgE sensitization to inhalant allergens, and serum total IgE levels in Japanese subjects. Methods: We conducted a survey of 1,540 subjects between 20 and 49 years of age in 2006 and 2007 and examined the prevalence of AR and sensitization to 7 common aeroallergens. We measured serum total IgE and specific IgE to 7 aeroallergens. AR was determined based on symptoms, predominantly in the nose and eyes, caused by aeroallergens as mentioned in a questionnaire and sensitization to any of the 7 aeroallergens as assessed by measurement of serum specific IgE. Results: The prevalence of AR was 44.2% (681 of the 1,540 subjects) and there was no difference among age decades. Of the 1,540 subjects, 1,073 (69.7%) were sensitized to at least 1 of the 7 aeroallergens. The most common allergen in AR was Japanese cedar pollen (89.6%, 610 of the 681 with AR) in all the age decades examined. The sensitization rate to mites was significantly higher in the younger subjects. Conclusion: Our data suggest that the prevalence of AR between 20 and 49 years of age has increased by nearly 10% during the last 10 years. Cedar pollen and mites were predominant allergen sources among the 7 aeroallergens in the Japanese population.
- Published
- 2009
- Full Text
- View/download PDF
5. Bax-gene transfer enhances apoptosis by steroid treatment in human nasal fibroblasts
- Author
-
Takeshi Tanaka, Norihiko Narita, Tetsuji Takabayashi, Chizuru Sugimoto, Akihiro Kojima, Yuichi Kimura, and Shigeharu Fujieda
- Subjects
medicine.medical_specialty ,Blotting, Western ,Apoptosis ,DNA Fragmentation ,Cell Line ,Nasal Polyps ,Bcl-2-associated X protein ,Internal medicine ,otorhinolaryngologic diseases ,Humans ,Medicine ,Nasal polyps ,Fibroblast ,Glucocorticoids ,bcl-2-Associated X Protein ,Regulation of gene expression ,biology ,business.industry ,Genetic transfer ,Gene Transfer Techniques ,DNA ,Genetic Therapy ,General Medicine ,Fibroblasts ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,Gene Expression Regulation ,Otorhinolaryngology ,biology.protein ,Cancer research ,Prednisolone ,Nasal administration ,business ,medicine.drug - Abstract
Gene therapy has become a focus not only in the study of cancer but also lifestyle-related diseases. In case of chronic rhinosinusitis with nasal polyps and aspirin-induced asthma, nasal polyps poorly respond to a local administration of steroid. The Bax and Bcl-2 proteins play important roles in the regulation of apoptosis. The treatment of steroid (prednisone) induced apoptosis in the fibroblast. The Bax accelerates apoptosis. Apoptosis is very important in the anti-inflammatory mechanism. In this study, we investigated whether the overexpression of Bax in human fibroblasts influences apoptosis by treatment with a steroid (prednisolone) in vitro. Human nasal fibroblasts were isolated from small pieces of nasal polyp and were transfected with a bax gene-bearing mammalian expression vector. Human nasal fibroblasts were transiently transfected with the expression vector hBaxpcDNA3 (Bax-NF) or native pcDNA3 (Neo-NF). Both transfectants (Bax-NF, Neo-NF) and wild-type-nasal fibroblast (wt-NF) were cultured in conditioning medium and treated with each concentration of prednisolone for 72 h. Prednisolone at a concentration of 10 ng/ml decreased the viability of Bax-NF compared to that of Bax-NF in the absence of prednisolone. The cytotoxicity of prednisolone to Bax-NF was significantly higher than that to Neo-NF or wt-NF (p < 0.01) and the susceptibility of Bax-NF to prednisolone was about 1,000 times that of Neo-NF or wt-NF. We found that the transfer of the exogenous bax gene enhanced the induction of apoptosis by steroid-treatment in human nasal fibroblasts. Therefore, we suggest that exogenous Bax protein expression by gene transfer might be useful for the treatment of nasal polyps. We will further the preclinical study in improving steroids dose and in adopting to transfer bax gene to the nasal polyps by intranasal injection, thus providing a more effective and safer way for the nasal polyps that poorly respond to a local administration of steroids.
- Published
- 2009
- Full Text
- View/download PDF
6. Improvement of image quality using interpolated projection data estimation method in SPECT
- Author
-
Akihiro Takaki, Kenya Murase, Tsutomu Soma, Masanori Matsumoto, Akihiro Kojima, Kimie Asao, and Shinya Kamada
- Subjects
Image quality ,Image processing ,Single-photon emission computed tomography ,law.invention ,Data acquisition ,law ,Statistics ,Image Processing, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Computer vision ,Cysteine ,Projection (set theory) ,Gamma camera ,Tomography, Emission-Computed, Single-Photon ,medicine.diagnostic_test ,Phantoms, Imaging ,business.industry ,Brain ,Organotechnetium Compounds ,General Medicine ,Artificial intelligence ,Tomography ,business ,Interpolation - Abstract
General data acquisition for single photon emission computed tomography (SPECT) is performed in 90 or 60 directions, with a coarse pitch of approximately 4-6 degrees for a rotation of 360 degrees or 180 degrees , using a gamma camera. No data between adjacent projections will be sampled under these circumstances. The aim of the study was to develop a method to improve SPECT image quality by generating lacking projection data through interpolation of data obtained with a coarse pitch such as 6 degrees .The projection data set at each individual degree in 360 directions was generated by a weighted average interpolation method from the projection data acquired with a coarse sampling angle (interpolated projection data estimation processing method, IPDE method). The IPDE method was applied to the numerical digital phantom data, actual phantom data and clinical brain data with Tc-99m ECD. All SPECT images were reconstructed by the filtered back-projection method and compared with the original SPECT images.The results confirmed that streak artifacts decreased by apparently increasing a sampling number in SPECT after interpolation and also improved S/N ratio of the root mean square uncertainty value. Furthermore, the normalized mean square error values, compared with standard images, had similar ones after interpolation. Moreover, the contrast and concentration ratios increased their effects after interpolation.These results indicate that effective improvement of image quality can be expected with interpolation. Thus, image quality and the ability to depict images can be improved while maintaining the present acquisition time and image quality. In addition, this can be achieved more effectively than at present even if the acquisition time is reduced.
- Published
- 2009
- Full Text
- View/download PDF
7. Benign Cystic Teratoma of the Parotid Gland
- Author
-
Akihiro Kojima, Masaki Mori, Shigeharu Fujieda, Makoto Ohta, Yoshiaki Imamura, and Hideki Maegawa
- Subjects
Pathology ,medicine.medical_specialty ,Histology ,Salivary gland ,Cystic teratoma ,business.industry ,Apocrine ,General Medicine ,Anatomy ,medicine.disease ,Pathology and Forensic Medicine ,Parotid gland ,medicine.anatomical_structure ,stomatognathic system ,Giant cell ,Major Salivary Gland ,medicine ,Cyst ,Teratoma ,business - Abstract
Background Mature cystic teratomas of the major salivary glands are rare. This report describes a case of a mature cystic teratoma of the left parotid gland, including the cytologic and bistopatbologic findings. Case A 17-year-old young woman presented with a slow-growing left parotid mass that had been present for 4 years. Preoperative fine needle aspiration cytology showed the presence of acinar and ductal cells, foamy cells and multinucleated giant cells. Imprint cytology of the surgical material showed the presence ofsome squamous cells and sebaceous gland-like cells with bair shafts. Cellular atypia was inconspicuous. Grossly, the 3-cm lesion was unicystic and embedded within the parotid gland parenchyma. Microscopically, the inner surface of the cyst was lined with keratinized squamous epithelium. The cyst wall contained skin adnexa such as sebaceous, eccrine and apocrine glands, as well as hair follicles. Some mature cartilage tissue was also detected. Foreign body granulomatous change was seen focally. No immature tissue or malignant transformation was found. Conclusion There is no previous report describing the cytologic findings of a mature cystic teratoma of the parotid gland. Mature cystic teratomas should therefore be considered in the differential diagnosis of a cystic lesion of the parotid gland.
- Published
- 2009
- Full Text
- View/download PDF
8. Iodine-131 imaging using 284 keV photons with a small animal CZT-SPECT system dedicated to low-medium-energy photon detection
- Author
-
Kumiko Gotoh, Seiji Okada, Masako Shimamoto, Koki Hasegawa, and Akihiro Kojima
- Subjects
030218 nuclear medicine & medical imaging ,law.invention ,Iodine Radioisotopes ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Optics ,law ,Spect imaging ,Medical imaging ,Medicine ,Animals ,Radiology, Nuclear Medicine and imaging ,Image resolution ,Tomography, Emission-Computed, Single-Photon ,Photons ,medicine.diagnostic_test ,business.industry ,Gamma ray ,Collimator ,General Medicine ,equipment and supplies ,Full width at half maximum ,Zinc ,Gamma Rays ,030220 oncology & carcinogenesis ,Radionuclide therapy ,Tellurium ,business ,Nuclear medicine ,Monte Carlo Method ,Emission computed tomography ,Cadmium - Abstract
Iodine-131 is widely used for radionuclide therapy because of its β-particle and for diagnostic imaging employing its principal gamma ray. Since that principal gamma ray has the relatively high energy of 364 keV, small animal single-photon emission computed tomography (SPECT) imaging systems may be required to possess the ability to image such higher energy photons. The aim of this study was to investigate the possibility of imaging I-131 using its 284 keV photons instead of its 364 keV photons in a small animal SPECT imaging system dedicated to the detection of low-medium-energy photons (below 300 keV). The imaging system used was a commercially available preclinical SPECT instrument with CZT detectors that was equipped with multi-pinhole collimators and was accompanied by a CT imager. An energy window for I-131 imaging was set to a photopeak of 284 keV with a low abundance compared with 364 keV photons. Small line sources and two mice, one of each of two types, that were injected with NaI-131 were scanned. Although higher counts occurred at the peripheral region of the reconstructed images due to the collimator penetration by the 364 keV photons, the shape of the small line sources could be well visualized. The measured spatial resolution was relatively poor (~1.9 mm for full width at half maximum and ~3.9 mm for full width at tenth maximum). However, a good linear correlation between SPECT values and the level of I-131 radioactivity was observed. Furthermore, the uptake of NaI-131 to the thyroid gland for the two mice was clearly identified in the 3D-SPECT image fused with the X-ray CT image. We conclude that the use of an energy window set on the photopeak of 284 keV and the multi-pinhole collimator may permit I-131 imaging for a preclinical CZT-SPECT system that does not have the ability to acquire images using the 364 keV photons.
- Published
- 2015
9. Optimum energy window setting on Hg-201 x-rays photopeak for effective Tl-201 imaging
- Author
-
Seiji Tomiguchi, Yasuyuki Yamashita, Teruya Noguchi, Masanori Matsumoto, Noboru Katsuda, Akihiro Kojima, and Akihiro Takaki
- Subjects
Photon ,Astrophysics::High Energy Astrophysical Phenomena ,Monte Carlo method ,Radiation Dosage ,Sensitivity and Specificity ,Imaging phantom ,Spectral line ,law.invention ,Optics ,law ,Image Interpretation, Computer-Assisted ,Medicine ,Radiology, Nuclear Medicine and imaging ,Thallium ,Radiometry ,Gamma camera ,Tomography, Emission-Computed, Single-Photon ,Phantoms, Imaging ,business.industry ,X-Rays ,Resolution (electron density) ,Reproducibility of Results ,Window (computing) ,General Medicine ,Image Enhancement ,Mercury Isotopes ,Energy Transfer ,business ,Nuclear medicine ,Algorithms ,Energy (signal processing) - Abstract
For more effective Tl-201 imaging, the location and width of the energy window set on the Hg-201 x-rays photopeak was investigated using Monte Carlo simulation and phantom experiments. We calculated energy spectra and investigated the amount of primary and scattered photons within various energy windows set on the x-rays photopeak. The energy resolution (ER) at 71 keV (the peak of the x-rays photopeak) was changed to 10%, 12%, 14% and 16%. The relationships between the energy window and the primary counts rate or the scatter fraction (= scattered counts/primary counts, SF) were obtained. By compromise between the primary counts rate and the SF for ER = 12%, the optimum energy window was determined as a wider off-peak window, 77 keV +/- 14.3% (66-88 keV). This off-peak window increased the primary counts rate by 12.5% and decreased the SF by -17% as compared with the conventional on-peak energy window (71 keV +/- 10%, 64-78 keV). When this off-peak widow acquisition was compared with the conventional on-peak window one on a gamma camera, planar and SPECT images using the off-peak widow clearly showed superior results qualitatively and quantitatively.
- Published
- 2005
- Full Text
- View/download PDF
10. Initial experience with X-ray ct based attenuation correction in myocardial perfusion spect imaging using a combined spect/ct system
- Author
-
Koichiro Yamada, Akihiro Kojima, Koichi Kawanaka, Yasuyuki Yamashita, Daisuke Utsunomiya, Tsuyoshi Honda, Seiji Tomiguchi, Shinya Shiraishi, and Kazuo Awai
- Subjects
Male ,medicine.medical_specialty ,Pilot Projects ,Coronary Artery Disease ,Pharmacological stress ,Coronary Angiography ,Sensitivity and Specificity ,Coronary artery disease ,Myocardial perfusion imaging ,Cohen's kappa ,Spect imaging ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Retrospective Studies ,Tomography, Emission-Computed, Single-Photon ,medicine.diagnostic_test ,Arterial stenosis ,business.industry ,Reproducibility of Results ,General Medicine ,Middle Aged ,Image Enhancement ,medicine.disease ,Coronary Vessels ,Equipment Failure Analysis ,Radiographic Image Enhancement ,Radiographic Image Interpretation, Computer-Assisted ,Female ,Radiology ,Tomography, X-Ray Computed ,business ,Nuclear medicine ,Correction for attenuation ,Perfusion - Abstract
Objective: Attenuation artifacts adversely affect the diagnostic accuracy of myocardial perfusion imaging. We assessed the clinical usefulness of X-ray CT based attenuation correction (AC) in patients undergoing myocardial perfusion imaging by comparing their myocardial AC- and non-corrected (NC) SPECT images with the coronary angiography (CAG).Methods: We retrospectively reviewed the myocardial SPECT images of 30 patients (18 men, 12 women; mean age 68 years). Thirteen of 30 patients with coronary artery disease (CAD) and 17 without CAD were confirmed by CAG. They underwent sequential CT and myocardial SPECT imaging with thallium-201 (111 MBq) under an exercise or pharmacological stress protocol using our combined SPECT/ CT system. Two readers reviewed the myocardial SPECT images for the presence of CAD on a 4-point scale where 1 = normal, 2 = probably normal, 3 = probably abnormal, and 4 = abnormal. Two reading sessions were held. First, non-corrected (NC)-SPECT and second, AC-SPECT images using X-ray CT images were interpreted. Interobserver variability was assessed with kappa statistics. Diagnostic performance (accuracy) of coronary arterial stenosis was compared between AC- and NC-images.Results: Interobserver agreement for visual assessment was substantial or almost perfect. For AC-images, the observer consensus for analysis was 0.84 for the LAD-, 0.87 for the LCX-, and 0.71 for the RCA-territory. For NC-images, it was 0.91, 0.71, and 0.78. AC resulted in statistically significant improvements in overall diagnostic accuracy (sensitivity/ specificity/accuracy = 76%/93%/89%, 67%/86%/81%, respectively, for AC- and NC-images).Conclusions: Because of an increase in the specificity, diagnostic accuracy was significantly increased on AC-images. These preliminary data suggest that X-ray CT based AC in myocardial SPECT imaging has the potential to develop into a reliable clinical technique.
- Published
- 2005
- Full Text
- View/download PDF
11. Attenuation correction using combination of a parallel hole collimator and an uncollimated non-uniform line array source
- Author
-
Takashi Ichihara, Nobutoku Motomura, Masanori Matsumoto, Daisuke Utsunomiya, Seiji Tomiguchi, Shinya Shiraishi, Takeshi Nakaura, Koichi Kawanaka, Yasuyuki Yamashita, Noboru Katsuda, and Akihiro Kojima
- Subjects
Tomography, Emission-Computed, Single-Photon ,Phantoms, Imaging ,business.industry ,Reproducibility of Results ,Technetium ,Collimator ,General Medicine ,For Attenuation Correction ,Imaging phantom ,law.invention ,Optics ,Transmission (telecommunications) ,law ,Spect imaging ,Attenuation coefficient ,Humans ,Medicine ,Radiology, Nuclear Medicine and imaging ,Radiopharmaceuticals ,business ,Nuclear medicine ,Correction for attenuation ,Gamma camera - Abstract
Attenuation correction is very important for quantitative SPECT imaging. We designed an uncollimated non-uniform line array source (non-uniform LAS) for attenuation correction based on transmission computed tomography (TCT) using Tc-99m and compared its performance with an uncollimated uniform line array source (uniform LAS) in a thorax phantom study. This non-uniform LAS was attached to one camera head of a dual-head gamma camera, and transmission data were acquired with another camera head with a low-energy, general purpose, parallel-hole collimator at 50 cm-distance apart from the source. The modified TEW using a subtraction factor of 1.0 was employed to correct scattered Tc-99m photons for transmission data. In the phantom experiment, eight TCT data were acquired with the scanning time changed from 2 minutes to 20 minutes for each LAS. The Tc-99m attenuation coefficient (mu) maps with the non-uniform LAS and uniform LAS improved the statistical count variation in the mediastinum filled with water as the scanning time got longer. The Tc-99m mu-map with the non-uniform LAS and 6 minutes of scanning time had equal quality at the center of the thorax phantom to that with the uniform LAS and 16 minutes of scanning time. In conclusion, for the TCT imaging with combination of the parallel hole collimator and uncollimated Tc-99m external source the non-uniform LAS can reduce the Tc-99m radioactivity or the TCT scanning time compared with the uniform LAS.
- Published
- 2004
- Full Text
- View/download PDF
12. Attenuation correction using asymmetric fanbeam transmission CT on two-head SPECT system
- Author
-
Takashi Ichihara, Koichi Kawanaka, Yasuyuki Yamashita, Akihiro Kojima, Seiji Tomiguchi, Shinya Shiraishi, Nobutoku Motomura, Daisuke Utsunomiya, Noboru Katsuda, Takeshi Nakaura, and Masanori Matsumoto
- Subjects
Myocardial Ischemia ,Sensitivity and Specificity ,Imaging phantom ,Collimated light ,law.invention ,Optics ,Sampling (signal processing) ,law ,Image Interpretation, Computer-Assisted ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Aged ,Tomography, Emission-Computed, Single-Photon ,medicine.diagnostic_test ,Phantoms, Imaging ,business.industry ,Attenuation ,Reproducibility of Results ,Heart ,Collimator ,Equipment Design ,General Medicine ,Image Enhancement ,Equipment Failure Analysis ,Subtraction Technique ,Attenuation coefficient ,Feasibility Studies ,Female ,Tomography, X-Ray Computed ,business ,Nuclear medicine ,Correction for attenuation ,Emission computed tomography - Abstract
For transmission computed tomography (TCT) systems using a centered transmission source with a fan-beam collimator, the transmission projection data are truncated. To achieve sufficiently large imaging field of view (FOV), we have designed the combination of an asymmetric fan-beam (AsF) collimator and a small uncollimated sheet-source for TCT, and implemented AsF sampling on a two-head SPECT system. The purpose of this study is to evaluate the feasibility of our TCT method for quantitative emission computed tomography (ECT) in clinical application. Sequential Tc-99m transmission and Tl-201 emission data acquisition were performed in a cardiac phantom (30 cm in width) with a myocardial chamber and a patient study. Tc-99m of 185 MBq was used as the transmission source. Both the ECT and TCT images were reconstructed with the filtered back-projection method after scatter correction with the triple energy window (TEW) method. The attenuation corrected transaxial images were iteratively reconstructed with the Chang algorithm utilizing the attenuation coefficient map computed from the TCT data. In this AsF sampling geometry, an imaging FOV of 50 cm was yielded. The attenuated regions appeared normal on the scatter and attenuation corrected (SAC) images in the phantom and patient study. The good quantitative accuracy on the SAC images was also confirmed by the measurement of the Tl-201 radioactivity in the myocardial chamber in the phantom study. The AsF collimation geometry that we have proposed in this study makes it easy to realize TCT data acquisition on the two-head SPECT system and to perform quantification on Tl-201 myocardial SPECT.
- Published
- 2004
- Full Text
- View/download PDF
13. Predictor of rehabilitation outcome for dysphagia
- Author
-
Akihiro Kojima, Yoshimasa Imoto, Shigeharu Fujieda, and Yoko Osawa
- Subjects
Male ,medicine.medical_specialty ,Activities of daily living ,medicine.medical_treatment ,Physical examination ,Aspiration pneumonia ,Pneumonia, Aspiration ,Severity of Illness Index ,Decision Support Techniques ,Cohort Studies ,Swallowing ,Modified Rankin Scale ,Internal medicine ,Activities of Daily Living ,medicine ,Humans ,Stroke ,Aged ,Retrospective Studies ,Aged, 80 and over ,Rehabilitation ,medicine.diagnostic_test ,business.industry ,General Medicine ,medicine.disease ,Prognosis ,Dysphagia ,Muscular Disorders, Atrophic ,Treatment Outcome ,Otorhinolaryngology ,Physical therapy ,Surgery ,Female ,medicine.symptom ,business ,Cognition Disorders ,Deglutition Disorders - Abstract
Objective Predicting whether dysphagia will resolve is very difficult, but is obviously important for patients and their families as well as for physicians. This study retrospectively evaluated potential prognostic indicators for dysphagia in order to examine the feasibility of predicting the outcome. Methods Data on 123 patients who received initial treatment for dysphagia between April 2008 and March 2010 were reviewed. The patient population included 63 men and 60 women, with a mean age of 81.4 years. All the patients underwent physical examination and video-endoscopy (VE) at the initial assessment, and video-fluorography (VF) was also done if necessary. We used the “Food Intake Level Scale” (FILS) to classify the severity of dysphagia as follows: “no oral intake” (FILS score: 1–3), “oral intake and alternative nutrition” (FILS score: 4–6), and “oral intake alone” (FILS score: 7–10). The patient's age, primary disease, cognitive ability, and general condition were evaluated as potential factors associated with the severity of dysphagia. Each patient underwent assessment at every 2 weeks to evaluate the progress of their dysphagia. Results Forty-six patients were classified as “no oral intake” (FILS score: 1–3) at the initial examination and subsequently showed improvement to “oral intake and alternative nutrition” (FILS score: 4–6) or “oral intake alone” (FILS score: 7–10). They were compared with 43 patients who were also “no oral intake” at the second examination after training in swallowing. The combination of stroke and cognitive dysfunction showed a sensitivity of 75.9% (22/29) and specificity of 78.3% (18/23) for predicting no improvement of dysphagia, and was a statistically significant parameter. The presence of disuse syndrome showed a sensitivity of 66.0% (31/47) and specificity of 71.4% (30/42) for predicting no improvement of dysphagia, and this was also a significant parameter. Conclusion The results of this study suggest that a combination of factors other than stroke, including cognitive dysfunction and a decrease in activity of daily living (ADL) influence the outcome of dysphagia. It is not rare for patients who resume oral intake to be readmitted within a year for symptoms such as fever. Therefore, effective rehabilitation programs should be developed for the impairments of elderly patients and common disabilities such as dysphagia.
- Published
- 2013
14. Correlation of Tc-99m GSA Hepatic Studies With Biopsies in Patients With Chronic Active Hepatitis
- Author
-
SEIJI TOMIGUCHI, TOMOHIRO KIRA, YOICHI OYAMA, MITSUKO NABESHIMA, RUMI NAKASHIMA, AKINORI TSUJI, AKIHIRO KOJIMA, MUTSUMASA TAKAHASHI, SHUNJI YOSHIMATSU, KATSURO SAGARA, and RYOICHI KURANO
- Subjects
Adult ,Male ,Pathology ,medicine.medical_specialty ,Necrosis ,Biopsy ,chemistry.chemical_element ,Technetium ,Scintigraphy ,Hepatitis ,Fibrosis ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Radionuclide Imaging ,Technetium Tc 99m Aggregated Albumin ,Aged ,medicine.diagnostic_test ,Chronic Active ,business.industry ,General Medicine ,Middle Aged ,medicine.disease ,Liver ,chemistry ,Chronic Disease ,Technetium Tc 99m Pentetate ,Female ,medicine.symptom ,Hepatic fibrosis ,business - Abstract
To determine whether scintigraphic findings of Tc-99m DTPA-galactosyl-HSA (GSA) correspond to histopathologic findings, Tc-99m GSA hepatic scintigraphy and biopsy were compared in 65 patients with chronic active hepatitis. After injecting 185 MBq of Tc-99m GSA, anterior images were obtained at 5 minutes and 15 minutes. Scintigrams were classified into three grades according to the extent of visualization of the cardiac blood pool on 5 minute and 15 minute images. Biopsies were subjectively graded for findings of necrosis and fibrosis. Scintigraphic grades on 5 minute images were correlated with hepatic necrosis and fibrosis and those on 15-minute images with hepatic fibrosis. Scintigraphic abnormalities of Tc-99m GSA correlated well with histopathologic abnormalities, especially with hepatic fibrosis and necrosis in patients with chronic active hepatitis.
- Published
- 1995
- Full Text
- View/download PDF
15. A preliminary phantom study on a proposed model for quantification of renal planar scintigraphy
- Author
-
Osamu Shimomura, Yoshikazu Takaki, Akihiro Kojima, Mutsumasa Takahashi, Masanori Matsumoto, Seiji Tomiguchi, M. Hara, and Yukinori Koga
- Subjects
Background subtraction ,Kidney ,medicine.diagnostic_test ,business.industry ,Attenuation ,Renal function ,Kidney Volume ,General Medicine ,Scintigraphy ,Imaging phantom ,Bruit ,medicine.anatomical_structure ,medicine ,medicine.symptom ,Nuclear medicine ,business - Abstract
A method for estimation of the absolute renal activity within background activity in renal planar scintigraphy will be presented. This method corrects for oversubtraction of background activity with consideration of background activity of the kidney volume, and employs the depth‐independent buildup factor (DIBF) method for the correction of attenuation and scatter of photons. This method requires the depth and thickness of the organ and the thickness of background for a background activity correction. The transmission factor (TF) for a volume source is derived from integrating TF for a thin source over the thickness of the organ for the DIBF method. To validate this method, phantom studies with various uniform background activity concentrations were performed and the data were compared with conventional background subtraction that do not consider the organ’s volume. The results showed that with the conventional background subtraction method at all depth activity was underestimated with errors of 5%–30% for organ/background concentration ratios of 5–40, while this method estimated the true count rate with errors of less than 5%. More accurate quantifications of renal functions such as renal uptake, glomerular filtration rate (GFR) and renogram may be obtained by this proposed method on the planar images.
- Published
- 1993
- Full Text
- View/download PDF
16. Therapeutic effects of γ-irradiation in a primary effusion lymphoma mouse model
- Author
-
Yoshioki Shiraishi, Tatsuya Shimasaki, Akihiro Kojima, Seiji Okada, Shinya Suzu, Tomomi Towata, and Kumiko Gotoh
- Subjects
Cancer Research ,Pathology ,medicine.medical_specialty ,primary effussion lymphoma ,viruses ,Biology ,Peritoneal cavity ,Immunology and Microbiology (miscellaneous) ,immune system diseases ,hemic and lymphatic diseases ,medicine ,MTT assay ,Cell growth ,animal model ,virus diseases ,General Medicine ,Articles ,Cell cycle ,Total body irradiation ,biochemical phenomena, metabolism, and nutrition ,medicine.disease ,Lymphoma ,medicine.anatomical_structure ,Apoptosis ,radiosensitivity ,Cancer research ,Primary effusion lymphoma - Abstract
Primary effusion lymphoma (PEL) is a unique and recently identified non-Hodgkin's lymphoma in immunocompromised individuals. PEL is caused by the Kaposi sarcoma-associated herpes virus/human herpes virus 8 (KSHV/HHV-8) and has a peculiar presentation involving liquid growth in the serous body cavity, chemotherapy resistance and poor prognosis. In search of a new therapeutic modality for PEL, we examined the effect of γ-irradiation on PEL-derived cell lines (BCBL-1, BC-1, and BC-3) in vitro and in vivo. An MTT assay and trypan blue exclusion assay revealed that irradiation significantly suppressed cell proliferation in the PEL cell lines in a dose-dependent manner, and induced apoptosis. The PEL cell lines were relatively radiosensitive compared with other hematological tumor cell lines (Raji, Jurkat, and K562 cells). Inoculation of the BC-3 cell line into the peritoneal cavity of Rag2/Jak3 double-deficient mice led to massive ascites formation, and subcutaneous injection of BCBL-1 led to solid lymphoma formation. Total body irradiation (4 Gy × 2) with bone marrow transplantation resulted in the complete recovery of both types of PEL-inoculated mice. These results suggest that total body irradiation with bone marrow transplantation can be successfully applied for the treatment of chemotherapy-resistant PEL.
- Published
- 2010
17. Correction of scattered photons in Tc-99m imaging by means of a photopeak dual-energy window acquisition
- Author
-
M. Hara, Masanori Matsumoto, Akihiro Kojima, Seiji Tomiguchi, Mutsumasa Takahashi, Yoshikazu Takaki, and Akinori Tsuji
- Subjects
Photon ,media_common.quotation_subject ,Radiation ,Imaging phantom ,Technetium Tc 99m Exametazime ,Optics ,Planar ,Oximes ,Humans ,Scattering, Radiation ,Medicine ,Contrast (vision) ,Radiology, Nuclear Medicine and imaging ,Brain Concussion ,media_common ,Tomography, Emission-Computed, Single-Photon ,business.industry ,Scattering ,Technetium ,Organotechnetium Compounds ,General Medicine ,Models, Structural ,Tomography ,business ,Nuclear medicine ,Dual energy window - Abstract
We are proposing a new method for correcting of scattered photons in technetium-99m (99mTc) imaging by means of photopeak dual-energy window acquisition. This method consists of the simultaneous acquisition of two images and estimation of a scatter image included in the symmetric energy window (SW) image by the difference between these images. The scatter corrected image is obtained by subtracting the scatter image from the SW image. In order to evaluate this method, we imaged a planar and a SPECT phantom with cold lesions and calculated the contrast value with and without the scatter correction. In addition, we performed asymmetric energy window (ASW) imaging to compare with this scatter correction method for planar images. In the planar image with the tissue-equivalent material of 10 cm, the scatter correction method removed 32% of the counting rate of the SW image and improved from 0.81 to 0.94 of the contrast value for a 4 cm-diameter cold lesion, while the contrast value with the ASW was 0.87 for such a cold lesion. The scatter corrected SPECT image had a reduction of 18% of the counting rate of the SW SPECT image and improvement of approximately 11% in contrast for cold spot sizes larger than a 3 cm-diameter, compared with the SW SPECT image. In addition, a perfusion defect could be well visualized by this scatter correction method on 99mTc-HMPAO regional cerebral blood flow SPECT of a patient. Our proposed scatter correction method can improve both planar and SPECT images qualitatively and quantitatively.
- Published
- 1992
- Full Text
- View/download PDF
18. Development of a collimator blurring compensation method using fine angular sampling projection data in SPECT
- Author
-
Koichi Ogawa, Kyojiro Nambu, Akihiro Kojima, Nobutoku Motomura, and Seiji Tomiguchi
- Subjects
Aperture ,Astrophysics::High Energy Astrophysical Phenomena ,Physics::Medical Physics ,Rotation ,Sensitivity and Specificity ,Imaging phantom ,law.invention ,Optics ,law ,Image Interpretation, Computer-Assisted ,Medicine ,Radiology, Nuclear Medicine and imaging ,Projection (set theory) ,Image resolution ,Tomography, Emission-Computed, Single-Photon ,business.industry ,Phantoms, Imaging ,Detector ,Reproducibility of Results ,Collimator ,General Medicine ,Radius ,Image Enhancement ,Physics::Accelerator Physics ,business ,Nuclear medicine ,Artifacts - Abstract
Due to the collimator aperture, spatial resolution of SPECT data varies with source-to-detector distance. Since the radius of detector rotation is bigger when scanning larger patients, spatial resolution is degraded in these cases. Emitted gamma rays travel not only along the central axis of the collimator hole but also off-axis due to the collimator aperture. However, an off-axis ray at one angle would be a central-axis ray at another angle; therefore, raw projection data at one angle can be thought of as an ensemble of central-axis rays collected from a small arc equal to the collimator aperture. Thus, fine angular sampling can compensate for collimator blurring. By using a sampling pitch of less than half the collimator aperture angle, compensation was performed by subtracting the weighted sum of the projection data from the raw projection data. Collimator geometry and detector rotation radius determined the weighting function. Cylindrical phantom with four different-sized rods and torso phantom for Tl-201 cardiac SPECT simulation were used for evaluation. Aperture angle of the collimator was 7 degrees. Projection sampling pitch was 2 degrees. In both phantom studies, the proposed method showed improvement in contrast and reduction of partial volume effect, thereby indicating that the proposed method can compensate adequately for image blurring caused by the collimator aperture.
- Published
- 2006
19. Oral and oropharyngeal squamous cell carcinomas expressing CCR7 have poor prognoses
- Author
-
Tetsuji Takabayashi, Noboru Takahashi, Hideaki Tsuzuki, Akihiro Kojima, Shigeharu Fujieda, Hiroshi Sunaga, and Norihiko Narita
- Subjects
Oncology ,Male ,medicine.medical_specialty ,Chemokine ,Receptors, CCR7 ,Cell ,chemical and pharmacologic phenomena ,C-C chemokine receptor type 7 ,Metastasis ,immune system diseases ,Internal medicine ,Proliferating Cell Nuclear Antigen ,medicine ,Humans ,Survival rate ,Proportional Hazards Models ,biology ,business.industry ,Head and neck cancer ,hemic and immune systems ,General Medicine ,Middle Aged ,medicine.disease ,Prognosis ,Immunohistochemistry ,stomatognathic diseases ,Oropharyngeal Neoplasms ,medicine.anatomical_structure ,Otorhinolaryngology ,Lymphatic Metastasis ,biology.protein ,Carcinoma, Squamous Cell ,Surgery ,Female ,Mouth Neoplasms ,Receptors, Chemokine ,Lymph Nodes ,Neoplasm Recurrence, Local ,business ,CC chemokine receptors - Abstract
Tumor cell migration and metastasis have many similarities with leukocyte trafficking regulated by chemokines and their receptors. In this study, we investigated the expression of CC chemokine receptor 7 (CCR7) in oral and oropharyngeal squamous cell carcinomas (SCCs) using an immunohistochemical approach.Among 90 cases of oral and oropharyngeal SCCs, 54 cases (60%) were positive for CCR7. The CCR7-positive group had a significantly lower incidence of being disease-free and an overall lower survival rate than the CCR7-negative group (p0.01 and p0.01, respectively). Among the 35 patients who died of cancer, 28 patients (80%) were positive for CCR7. The expression of CCR7 was significantly associated with five clinical factors. SCCs expressing CCR7 tend to have large, lymph node metastases, progressive stages, local recurrences and cancer death. The CCR7 expression of metastatic SCCs in draining lymph nodes was detected, and the staining score of CCR7 between primary SCCs and metastatic SCCs were significantly correlated (p0.01).The investigation of CCR7 expression in oral and oropharyngeal SCCs may be useful to predict patients prognoses.
- Published
- 2005
20. Accurate scatter correction for transmission computed tomography using an uncollimated line array source
- Author
-
Masanori Matsumoto, Akihiro Kojima, Noboru Katsuda, Seiji Tomiguchi, Nobutoku Motomura, and Yasuyuki Yamashita
- Subjects
Photon ,Sensitivity and Specificity ,Imaging phantom ,law.invention ,Optics ,law ,Spect imaging ,medicine ,Scattering, Radiation ,Radiology, Nuclear Medicine and imaging ,Linear Energy Transfer ,Gamma camera ,Tomography, Emission-Computed, Single-Photon ,medicine.diagnostic_test ,business.industry ,Phantoms, Imaging ,Reproducibility of Results ,Collimator ,General Medicine ,Image Enhancement ,Equipment Failure Analysis ,Attenuation coefficient ,Subtraction Technique ,business ,Nuclear medicine ,Tomography, X-Ray Computed ,Correction for attenuation ,Emission computed tomography - Abstract
We investigated scatter correction in transmission computed tomography (TCT) imaging by the combination of an uncollimated transmission source and a parallel-hole collimator. We employed the triple energy window (TEW) as the scatter correction and found that the conventional TEW method, which is accurate in emission computed tomography (ECT) imaging, needs some modification in TCT imaging based on our phantom studies. In this study a Tc-99m uncollimated line array source (area: 55 cm x 40 cm) was attached to one camera head of a dual-head gamma camera as a transmission source, and TCT data were acquired with a low-energy, general purpose (LEGP), parallel-hole collimator equipped on the other camera head. The energy spectra for 140 keV-photons transmitted through various attenuating material thicknesses were measured and analyzed for scatter fraction. The results of the energy spectra showed that the photons transmitted had an energy distribution that constructs a scatter peak within the 140 keV-photopeak energy window. In TCT imaging with a cylindrical water phantom, the conventional TEW method with triangle estimates (subtraction factor, K = 0.5) was not sufficient for accurate scatter correction (micro = 0.131 cm(-1) for water), whereas the modified TEW method with K = 1.0 gave the accurate attenuation coefficient of 0.153 cm(-1) for water. For the TCT imaging with the combination of the uncollimated Tc-99m line array source and parallel hole collimator, the modified TEW method with K = 1.0 gives the accurate TCT data for quantitative SPECT imaging in comparison with the conventional TEW method with K = 0.5.
- Published
- 2004
21. Diagnostic accuracy of simultaneous acquisition of transmission and emission data with technetium-99m transmission source on thallium-201 myocardial SPECT
- Author
-
Akinori Tsuji, Seiji Tomiguchi, Masanori Matsumoto, Tomohiro Kira, Yoshito Inobe, Mitsuko Kira, Yoichi Ohyama, Akihiro Kojima, Mutsumasa Takahashi, and Hirofumi Yasue
- Subjects
medicine.medical_specialty ,chemistry.chemical_element ,Coronary Disease ,Single-photon emission computed tomography ,Sensitivity and Specificity ,Isotopes of technetium ,Coronary artery disease ,Data acquisition ,Reference Values ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,cardiovascular diseases ,Tomography, Emission-Computed, Single-Photon ,Likelihood Functions ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,Technetium ,Heart ,General Medicine ,medicine.disease ,Thallium Radioisotopes ,chemistry ,Databases as Topic ,Thallium ,Radiology ,Nuclear medicine ,business ,Correction for attenuation ,Technetium-99m ,Emission computed tomography - Abstract
This study evaluates not only the clinical usefulness but also the problems in attenuation correction for thallium-201 (Tl-201) myocardial SPECT by means of simultaneous transmission and emission data acquisition in the detection of coronary artery disease (CAD).A three-detector SPECT system equipped with a Tc-99m line source and fan-beam collimators was used for simultaneous transmission and emission data acquisition for Tl-201 myocardial SPECT in 73 patients (18 patients for normal database and 55 patients for the evaluation of diagnostic accuracy). Attenuation-corrected (AC) images and non-attenuation-corrected (NC) images were reconstructed with an iterative maximum-likelihood estimation-corrected (ML-EM) algorithm. Both sets of images were reoriented into the short axis. Normal database polar maps were constructed from the AC and NC images for quantitative analysis.There was a significant difference in specificity between NC and AC images in the RCA territory and those in specificity and accuracy in the LCX territory. There was no significant difference in sensitivity found between NC and AC images in either territory, but sensitivity in both territories tended to decrease with attenuation correction. In the LAD territory, there were various changes in sensitivity and specificity observed with attenuation correction in cases with each quantitative criterion.Diagnostic performance of significant stenosis in the RCA and LCX territories quantitatively improved with attenuation correction because of an increase in specificity, but no significant improvement in diagnostic performance was obtained in the LAD territory with attenuation correction. We recommend combined interpretation of AC and NC images and careful evaluation of any SPECT image by means of transmission computed tomography.
- Published
- 2001
22. Quantitative planar imaging method for measurement of renal activity by using a conjugate-emission image and transmission data
- Author
-
Mitsuko Kira, Seiji Tomiguchi, Akihiro Kojima, Yoichi Ohyama, Masanori Matsumoto, Mutsumasa Takahashi, Nobutoku Motomura, and Takashi Ichihara
- Subjects
Physics ,Planar Imaging ,business.industry ,Phantoms, Imaging ,Technetium ,General Medicine ,For Attenuation Correction ,Kidney ,Measure (mathematics) ,Image (mathematics) ,law.invention ,Optics ,Transmission (telecommunications) ,Approximation error ,law ,Medical imaging ,Scattering, Radiation ,Radiopharmaceuticals ,business ,Radiometry ,Radioisotope Renography ,Gamma camera - Abstract
We are proposing a method to accurately measure renal activity in renography using Tc-99m labeled tracers. This method uses a conjugate-view image and transmission data for attenuation correction, the triple energy window (TEW) method for scatter correction, and background correction techniques that consider the source volume for accurate background activity correction. To examine this method in planar imaging, we performed two renal phantom studies with various uniform background activity concentrations. One study used two ideal box-shaped kidney phantoms with a thickness of 2 or 4 cm in a water tank and the other study employed two real kidney-shaped phantoms in a fillable abdominal cavity. For these studies the kidney phantom-to-background activity concentration ratio (S) was changed from 5 to infinity. The transmission data were obtained with an external Tc-99m line array source. The anterior- and posterior-view emission images were acquired with a dual-headed gamma camera simultaneously and the TEW method was used to correct scatter for the emission and transmission images. The results showed that this method with both the accurate background correction and scatter correction could give depth-independent count rates and could estimate the true count rate with errors of less than 5% for all S values. However, if either accurate background correction or scatter correction was performed alone, the absolute error increased to about 50% for the smaller S values. Our proposed method allows one to accurately and simply measure the renal radioactivity by planar imaging using the conjugate-emission image and transmission data.
- Published
- 2000
23. Quantitative renography with the organ volume method and interporative background subtraction technique
- Author
-
Rumi Nakashima, Mutsumasa Takahashi, Yoshikazu Takaki, Seiji Tomiguchi, M. Hara, Mitsuko Kira, Akihiro Kojima, Masanori Matsumoto, and Akinori Tsuji
- Subjects
Background subtraction ,Planar Imaging ,business.industry ,Phantoms, Imaging ,Attenuation ,Renal function ,General Medicine ,Kidney ,Kidney Function Tests ,Imaging phantom ,Isotopes of technetium ,Mockup ,Evaluation Studies as Topic ,Technetium-99 ,Subtraction Technique ,Medicine ,Humans ,Technetium Tc 99m Pentetate ,Radiology, Nuclear Medicine and imaging ,business ,Nuclear medicine ,Radioisotope Renography - Abstract
When quantification of renal activity is performed by planar imaging, many correction factors must be considered. To obtain quantitative renal images and renogram, we have examined our proposed method by using the organ volume for scatter, attenuation, and background activity, and the interporative background subtraction (IBS) technique in phantom and clinical studies. A renal phantom study was performed by varying the renal depth from 3 to 11 cm and the kidney-to-background activity concentration ratio from 5 to 80. Planar images were properly corrected for scatter, attenuation and background activity by our method and the corrected images were compared with the images obtained by the conventional method for the estimation of true renal activity. Clinical Tc-99m DTPA dynamic data for both a good and a poor renal function were also corrected by our method and volume-corrected renograms were obtained. For the phantom study, depth-independent images were obtained and these images gave a good estimation of the true count rate. In the clinical study, the conventional renogram was especially modified to allow for oversubtraction of background counts in the early phase (0–4 min). In conclusion, our proposed correction method can assess renal function qualitatively and quantitatively in both static and dynamic planar renal imaging.
- Published
- 1996
24. Effect of energy resolution on scatter fraction in scintigraphic imaging: Monte Carlo study
- Author
-
Mutsumasa Takahashi, Shuzo Uehara, Masanori Matsumoto, and Akihiro Kojima
- Subjects
Physics ,business.industry ,Monte Carlo method ,Resolution (electron density) ,Biophysics ,General Medicine ,Line source ,Imaging phantom ,Spectral line ,Biophysical Phenomena ,Models, Structural ,Full width at half maximum ,Optics ,Evaluation Studies as Topic ,Image Processing, Computer-Assisted ,Humans ,Scattering, Radiation ,Image sensor ,business ,Radionuclide Imaging ,Monte Carlo Method ,Energy (signal processing) - Abstract
The effect of energy resolution in detector systems on scatter fractions in scintigraphic imaging through Monte Carlo simulation is investigated. A 10‐cm Tc‐99m line source within a cylindrical water phantom 20 cm in diameter and 20 cm in length was modeled and energy spectra were calculated at three different line source positions. The energy resolution was changed from 8% to 16% FWHM at 140 keV and a symmetrical energy window width was varied from 8% to 23% on the photopeak of 140 keV in energy spectra corresponding to each energy resolution. The relationship between the scatter fraction and the symmetrical energy window width, and the relationship between the scatter fraction and the primary counts were presented for all energy resolutions investigated. Furthermore, the effect of the asymmetrical energy window on reducing the scatter fraction was also studied and compared with the narrow symmetrical energy window. The results quantitatively showed that improved energy resolution can considerably decrease the scatter fraction with a narrow symmetrical energy window or an asymmetrical energy window without significant primary count‐loss compared to that obtained with lower quality energy resolution. The asymmetrical energy window could reduce scatter fraction as compared with the narrow symmetrical energy window when the same number of primary counts was required for both energy windows. Knowing the relationship between the scatter fraction and the primary counts is important in scintigraphic imaging to select the optimum energy window corresponding to the energy resolution.
- Published
- 1993
25. Hydroxamamide as a chelating moiety for the preparation of 99Tcm radiopharmaceuticals (I)
- Author
-
Seiji Tomiguchi, R. Kinoshita, E. Kai, Kumiko Harada, Morio Nakayama, H. Saigo, Michiko Hara, Munehiro Takahashi, A. Sugii, A. Koda, Akihiro Kojima, and H. Ozeki
- Subjects
Male ,Ligand ,business.industry ,chemistry.chemical_element ,General Medicine ,Organotechnetium Compounds ,Hydroxamic Acids ,Ligands ,Nitrogen ,Oxygen ,chemistry.chemical_compound ,Mice ,Hydroxylamine ,chemistry ,Yield (chemistry) ,Moiety ,Animals ,Radiology, Nuclear Medicine and imaging ,Chelation ,Tissue Distribution ,Cellulose ,Nuclear medicine ,business ,Nuclear chemistry ,Chelating Agents - Abstract
Hydroxamamides contain a nitrogen and an oxygen as donor atoms, and can be synthesized by the simple reaction of nitriles with hydroxylamine. Benzohydroxamamide (BHam) was investigated as a new ligand for 99Tcm. The yield of the 99Tcm-BHam complex was determined by thin-layer chromatography using cellulose strips. A high yield of the complex was obtained at room temperature over a wide pH range, even at BHam concentrations as low as 5 x 10(-7) M. Cellulose acetate electrophoresis indicated that the complex was uncharged. When the 99Tcm-BHam complex was injected into mice, it was cleared gradually from the blood by means of the hepatobiliary system with low urinary excretion. Uptake by the stomach and the spleen was low. These results demonstrate the high affinity of BHam for 99Tcm and the high stability of the 99Tcm-BHam complex. The hydroxamamide group may be a promising chelating moiety for designing new 99Tcm radiopharmaceuticals.
- Published
- 1992
26. Usefulness of reinjection image for evaluating viable myocardium in the infarcted zone on exercise thallium-201 SPECT
- Author
-
Hirofumi Yasue, Seiji Tomiguchi, Kazuya Hayasaki, Akihiro Kojima, Osamu Shimomura, Yukinori Koga, M. Hara, Mutsumasa Takahashi, and Kotaro Minoda
- Subjects
Adult ,Male ,medicine.medical_specialty ,Time Factors ,Myocardial Infarction ,Coronary artery disease ,Internal medicine ,medicine ,Delayed imaging ,Humans ,Radiology, Nuclear Medicine and imaging ,In patient ,Myocardial infarction ,Radionuclide Imaging ,Aged ,Aged, 80 and over ,business.industry ,General Medicine ,Middle Aged ,medicine.disease ,Exercise Thallium ,Thallium Radioisotopes ,Cardiology ,Exercise Test ,Female ,business ,Nuclear medicine ,Perfusion - Abstract
Reinjection images were obtained in 23 patients with myocardial infarction by the additional injection of 37 MBq of thallium-201 after obtaining 4 hour delayed images on exercise thallium-201 SPECT (TSPECT). A redistribution index (RI) was derived of the changes in perfusion defects between immediate and 4 hour delayed images as well as immediate and reinjection images on polar bull's eye maps. The RI of reinjection images (46 +/- 27%) was significantly greater than that of 4 hour delayed images (26 +/- 26%) in patients with myocardial infarction (p less than 0.01). Significant redistribution after reinjection occurred in 4 of 9 patients (44%) without significant redistribution on 4 hour delayed images. Improvement in redistribution on reinjection images correlated significantly to the small extent of coronary artery disease and collateral development. The appearance of redistribution from 4 hour delayed imaging to reinjection imaging also might reflect the function of collateral development in the resting state in patients without significant redistribution on 4 hour delayed images. It has been demonstrated that underestimated viable myocardium on 4 hour delayed images in the infarcted zone can be better assessed on reinjection images. This reinjection technique is recommended in patients with no or partial redistribution on 4 hour delayed images.
- Published
- 1991
27. Experimental analysis of scattered photons in Tc-99m imaging with a gamma camera
- Author
-
Masanori Matsumoto, Mutsumasa Takahashi, and Akihiro Kojima
- Subjects
Photon ,Radiation ,business.industry ,Scattering ,Compton scattering ,Technetium ,General Medicine ,Imaging phantom ,Spectral line ,law.invention ,Models, Structural ,Optics ,law ,Attenuation coefficient ,Medicine ,Scattering, Radiation ,Radiology, Nuclear Medicine and imaging ,business ,Nuclear medicine ,Radionuclide Imaging ,Gamma camera ,Line Spread Function - Abstract
The amount of scattered photons in a clinical imaging window of Tc-99m was experimentally measured by means of a line source with scattering materials and a gamma camera. A symmetrical photopeak energy window centered at 140 keV with a width of 20% (126–154 keV) was partitioned into several small windows. Energy spectra were analyzed to determine the scatter fraction and the attenuation coefficient for each window. Line spread functions (LSF) were also obtained to characterize the spatial scatter distribution. The results of analysis of energy spectra show that scattered photons are included over the symmetric 20% window (SW) and scatter fractions increase linearly with the increasing thickness of the scattering material in all energy windows investigated. In addition, the results for the LSF show that the scatter distribution within the SW is represented as a mono-exponential function. Experimental measurements obtained with a phantom and a gamma camera simplify accurate quantification of scattered photons. Such quantitative analysis of scattered photons is important in developing and evaluating a scatter correction technique.
- Published
- 1991
28. Development of macromolecular Sn(II) complex for preparation of 99Tcm radiopharmaceuticals
- Author
-
M. Hara, K. Harada, T. Terahara, A. Sugii, Seiji Tomiguchi, Y. Hirota, Akihiro Kojima, M. Takahashi, Morio Nakayama, O. Shimomura, H. Izunaga, and M. Wada
- Subjects
Chelating resin ,Chemistry ,Ligand ,Reducing agent ,business.industry ,Macromolecular Substances ,General Medicine ,Human serum albumin ,chemistry.chemical_compound ,Tin ,Diethylenetriamine ,medicine ,Technetium Tc 99m Pentetate ,Radiology, Nuclear Medicine and imaging ,Chelation ,Adsorption ,Nuclear medicine ,business ,Technetium Tc 99m Aggregated Albumin ,Macromolecule ,Nuclear chemistry ,medicine.drug ,Chelating Agents - Abstract
Macromolecular Sn(II) complex (R-Sn) was developed using a chelating resin containing aminophosphonic acid groups as a reducing agent of 99Tcm(VII) in the preparation of 99Tcm radiopharmaceuticals. Since Sn(II) was bonded strongly to the resin by chelation, release of Sn from R-Sn was rarely observed in saline solution. 99Tcm labelling with a yield greater than 90% was performed by mixing R-Sn, 99Tcm pertechnetate solution and a ligand, such as human serum albumin and diethylenetriamine pentaacetic acid, for a short time. The 99Tcm radiopharmaceuticals were almost free from Sn(II) and the reducing activity of R-Sn was quite stable despite long-term storage without any special care.
- Published
- 1991
29. Outbreak of neonatal canine herpesvirus infection in a specific pathogen-free beagle colony
- Author
-
Azusa Okaniwa, Fujio Fujinami, Akihiro Kojima, Takaaki Yamamura, Masakazu Takeshita, Yoshio Minato, and Kazunori Imaizumi
- Subjects
Lung Diseases ,Pathology ,medicine.medical_specialty ,Necrosis ,Ecchymosis ,Biology ,Beagle ,Disease Outbreaks ,Canine herpesvirus ,Dogs ,Pregnancy ,Edema ,medicine ,Animals ,Dog Diseases ,Fibrinoid necrosis ,Animal Husbandry ,Herpesviridae ,Specific-pathogen-free ,Cesarean Section ,Liver Diseases ,Outbreak ,General Medicine ,Herpesviridae Infections ,biology.organism_classification ,medicine.disease ,Specific Pathogen-Free Organisms ,Animals, Newborn ,Female ,Kidney Diseases ,medicine.symptom - Abstract
Nine out of 19 newborn pups from 4 litters died or euthanatized on day 10 to 17 after birth in a specific-pathogen-free beagle colony which had been established by cesarean section and bottle-feeding. Necropsy showed congestion and edema of the lungs, congestion of the liver and splenomegaly, as well as many subcapsular petechiae and wedge-shaped areas of ecchymosis on the cut surface of the kidneys. A cytopathic agent isolated from the lungs, kidneys and liver was identified as a canine herpesvirus. The bitches in the animal house were seroconverted into positive for the isolate after the outbreak of the disease. Histopathological lesions in six cases were characterized by multiple necrosis and hemorrhage in various organs. In addition, fibrinoid necrosis was seen in the arterial walls in wedge-shaped necrotic areas of the kidneys. The outbreak appeared to be temporary, since the same disease has not occurred in the colony up to the present time.
- Published
- 1990
30. Hepatic fibrosis produced in rats by repeated intraperitoneal injections of swine serum
- Author
-
Azusa Okaniwa, Akira Yasoshima, Akihiro Kojima, Kunio Doi, O. Hitoshi Iwasaki, and Kazuyuki Kitamura
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Swine ,Spleen ,Kidney ,Immunofluorescence ,Fibrosis ,medicine ,Animals ,medicine.diagnostic_test ,business.industry ,Germinal center ,Rats, Inbred Strains ,General Medicine ,medicine.disease ,Rats ,Microscopy, Electron ,Blood ,medicine.anatomical_structure ,Lymphatic system ,Perisinusoidal space ,Liver ,Hepatic fibrosis ,business ,Infiltration (medical) - Abstract
Pathological observations were made on male Sprague-Dawley rats which had received intraperitoneal injections of sterile swine serum twice a week for 12 weeks. Changes were found mainly in the liver, kidneys and spleen. In the liver, pseudolobules were formed in all animals after 8 or more weeks. Proliferation of collagen fibers was detected first around the central veins and in the portal tracts after 3 weeks, and then in the space of Disse. After 8 or more weeks, numerous fat-storing cells (Ito's cells) were found in the collagen septa subdividing the lobules. In the initial stage of fibrosis, infiltration of eosinophils and mast cells was observed around the central veins and in the portal tracts. There were no noticeable changes, however, in hepatocytes or sinusoidal lining cells throughout the experimental period. In the kidneys, fine electron-dense deposits were found in the mesangial area of glomeruli after 4 or more weeks. In the corresponding sites, specific fluorescence of rat IgG was detected by the immunofluorescence technique. In the spleen, swelling and increased lymphatic follicles with active germinal centers were noticed after 2 or more weeks.
- Published
- 1984
- Full Text
- View/download PDF
31. Canine Parvovirus Infection in a Group of Beagles
- Author
-
Akihiro Kojima, Akira Yasoshima, Shuji Nitta, Masayuki Baba, Norihisa Kato, and Toshiyuki Abiko
- Subjects
Fetus ,Leukopenia ,General Veterinary ,biology ,business.industry ,Canine parvovirus infection ,Crypt ,Outbreak ,General Medicine ,Feline panleukopenia ,biology.organism_classification ,Virology ,Agar gel ,General Biochemistry, Genetics and Molecular Biology ,Virus antigen ,Medicine ,Animal Science and Zoology ,medicine.symptom ,business - Abstract
An outbreak of canine parvovirus infection in a group of 26 beagles was described. The disease characterized by acute intestinal involvement was highly contagious but fatality was low (1/26). Transient leukopenia was recorded in some animals. All the convalescent sera were positive in agar gel diffusion test using feline panleukopenia virus antigen. Histopathological examination on fetal dog revealed regressive change associated with formation of amphophilic intranuclear inclusion bodies in the enterocytes of the Lieberkuhn's crypt and regressive change in the lymphoid tissues. Pathologic picture exhibited strikingly resemblance with that of feline panleukopenia.
- Published
- 1981
- Full Text
- View/download PDF
32. Studies on biologically active nucleosides and nucleotides. IV. Synthesis of 1-.BETA.-D-arabinofuranosyl-2-aralkylamino-1,4-dihydro-4-iminopyrimidine hydrochlorides
- Author
-
Akihiro Kojima, Ichizo Inoue, and Kazuhiko Kondo
- Subjects
Antitumor activity ,chemistry.chemical_classification ,chemistry.chemical_compound ,Aminolysis ,chemistry ,Hydrochloride ,Stereochemistry ,Drug Discovery ,Nucleotide ,Biological activity ,General Chemistry ,General Medicine ,Methanol - Abstract
Some 1-β-D-arabinofuranosyl-2-aralkylamino-1, 4-dihydro-4-iminopyrimidine hydrochlorides (2a-c) were prepared by the reaction of 2, 2'-anhydro-1-(β-D-arabinofuranosyl)-cytosine hydrochloride (1) with the corresponding aralkylamines (1 equiv.) in methanol. Treatment of 1 with an excess of the amines gave 1-β-D-arabinofuranosyl-2-aralkylamino-1, 4-dihydro-4-aralkyliminopyrimidine hydrochlorides (3a, b). These compounds were inactive against leukemia L-1210 and Ehrlich carcinoma in mice.
- Published
- 1978
- Full Text
- View/download PDF
33. A case of HCG-producing suprasellar germinoma with hypothalamic syndrome associated with acute renal failure
- Author
-
Akira Tomonari, Hiroshi Bando, Shiro Saito, Shigeaki Kimura, Ryuichi Yamasaki, Akihiro Kojima, Yoko Omori, Shuuichi Miyazaki, and Kazuhito Kameyama
- Subjects
Male ,medicine.medical_specialty ,Adolescent ,Germinoma ,business.industry ,Skull Neoplasms ,Dysgerminoma ,Syndrome ,General Medicine ,Acute Kidney Injury ,medicine.disease ,Chorionic Gonadotropin ,Combined Modality Therapy ,Hypopituitarism ,Hyperprolactinemia ,Endocrinology ,Internal medicine ,medicine ,Humans ,Sella Turcica ,business ,Hypothalamic syndrome - Abstract
HCG産生鞍上部胚芽腫により,尿崩症,高Na血症,視床下部性下垂体前葉機能低下症,高プロラクチン血症などの視床下部症候群を呈し,経過中に急性腎不全を合併した14才男性例を報告した. TRH・LHRH・LVP・GHRHによる4者負試験およびinsulin, arginine, L-dopaの各負荷試験を用いて,放射線照射と化学療法による治療前後の視床下部下垂体機能の変化を明らかにした.急性糸球体腎炎に起因すると思われる急性腎不全期には,尿量の減少,クレアチニンクリアランスの低下およびNa血症の改善を認めた.尿崩症に腎不全が合併した症例は未だ報告がなく,尿崩症の場合の尿量も糸球体〓過率によって強く影響をうけることが示された.
- Published
- 1988
- Full Text
- View/download PDF
34. Effects of an oral water load and intravenous administration of isotonic glucose, hypertonic saline, mannitol and furosemide on the release of atrial natriuretic peptide in men
- Author
-
Shiro Saito, Yasuhiro Yamasaki, Takeshi Nishiuchi, Akihiro Kojima, and Haruhiko Saito
- Subjects
Adult ,Male ,medicine.medical_specialty ,Adolescent ,Endocrinology, Diabetes and Metabolism ,Sodium ,Administration, Oral ,chemistry.chemical_element ,Sodium Chloride ,Peptide hormone ,Osmolar Concentration ,Electrolytes ,Endocrinology ,Atrial natriuretic peptide ,Furosemide ,Internal medicine ,medicine ,Humans ,Mannitol ,Plasma Volume ,Child ,Infusions, Intravenous ,Aged ,Saline Solution, Hypertonic ,Age Factors ,Infant ,Water ,Blood Proteins ,General Medicine ,Middle Aged ,Blood proteins ,Hypertonic saline ,Glucose ,chemistry ,Child, Preschool ,Atrial Natriuretic Factor ,medicine.drug - Abstract
The effects of an oral water load and iv administration of isotonic glucose, hypertonic saline, mannitol and furosemide on release of human atrial natriuretic peptide (hANP) were examined in normal subjects to determine the main factors causing its release. In addition, the influence of age on hANP secretion was investigated. The mean plasma hANP level in normal subjects, 0–89 years old, was 20.6 ± 1.1 ng/l (mean ± sem) and showed age-related change. The plasma hANP level did not change significantly after a water load or infusion of isotonic glucose, but rose significantly from 11.4 ± 1.4 to 15.6 ± 3.2 ng/l after infusion of hypertonic saline and from 10.9 ± 1.6 to 17.8 ± 4.1 ng/l after infusion of 20% mannitol in parallel with the increase in plasma volume. The plasma hANP level decreased from 17.3 ± 2.5 to 9.0 ± 2.5 ng/l after injection of 40 mg of furosemide. A positive correlation was found between change in the plasma hANP level and percent change in the plasma volume (P < 0.001) on these treatments. The response of plasma hANP to hypertonic saline infusion was greater in older than in young men. These results indicate that 1) the secretion of hANP shows an age-related change and 2) increase in the circulating plasma volume is an important factor regulating hANP secretion.
- Published
- 1988
- Full Text
- View/download PDF
35. Pathological Observations on Natural Cases of Sialodacryoadenitis of Rats
- Author
-
Shigeo Kurabe, Hitoshi Okawa, Azusa Okaniwa, Akira Yasoshima, Akihiro Kojima, and Kunio Doi
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Submandibular Gland ,Connective tissue ,Salivary Gland Diseases ,Inflammation ,Biology ,Sialadenitis ,General Biochemistry, Genetics and Molecular Biology ,Rodent Diseases ,Lesion ,Dacryocystitis ,stomatognathic system ,Male rats ,medicine ,Animals ,Parotid Gland ,Pathological ,General Veterinary ,Harderian Gland ,General Medicine ,Primary lesion ,medicine.disease ,Squamous metaplasia ,Rats ,Serous fluid ,medicine.anatomical_structure ,Animal Science and Zoology ,medicine.symptom - Abstract
Pathological observations were carried out on 100 male rats of Sprague-Dawley strain obtained from 5 outbreaks of sialodacryoadenitis (SDA). In accordance with clinical and macroscopic findings, principal microscopic changes were found in the salivary (submaxillary and parotid) and Harderian glands. Lesions observed in these different glands were essentially similar to each other, and characterized by degenerative changes in the epithelial cells of the ducts and acini associated with marked and extensive serous inflammation in the interstice. Furthermore, squamous metaplasia of the ductal epithelia was a common feature to these glands in the late stage of the disease. Some differences, however, were detected between the changes of the salivary glands and those of the Harderian glands. Firstly, the ductal epithelial cells were affected at first and the acinous epithelial cells were damaged only secondarily in the active inflammatory process in the salivary glands, while both ductal and acinous epithelial cells were involved equally in the primary lesion in the Harderian glands. Secondly, the increase in connective tissue elements in the reparatory process was extremely marked in the Harderian glands as compared with the salivary glands. Consequently, in the lesion of Harderian glands in the late stage, original construction was almost indiscernible, and the ducts and acini were only recognized as disseminated islets in actively proliferated connective tissue elements.
- Published
- 1980
- Full Text
- View/download PDF
36. Pathology of sialodacryoadenitis virus infection in newborn mice
- Author
-
Akihiro Kojima, Hisashi Yamanaka, Azusa Okaniwa, Hiroshi Takada, Kunio Doi, and Akira Yasoshima
- Subjects
Coronaviridae ,Coronaviridae Infections ,business.industry ,Brain ,Fluorescent Antibody Technique ,Mice, Inbred Strains ,General Medicine ,Virology ,Rodent Diseases ,Mice ,Animals, Newborn ,Animals ,Medicine ,Sialodacryoadenitis virus ,business ,Antigens, Viral - Published
- 1983
- Full Text
- View/download PDF
37. Feline Viral Rhinotracheitis in Japan : Isolation of Herpes Type Virus and Pathologic Picture
- Author
-
Akihiro Kojima, Akira Yasoshima, Kunio Doi, Hitoshi Okawa, and Yoshiharu Inami
- Subjects
biology ,Isolation (health care) ,General Medicine ,biology.organism_classification ,Virology ,Feline viral rhinotracheitis ,Virus - Published
- 1975
- Full Text
- View/download PDF
38. Isolation and Properties of Sialodacryoadenitis Virus of Rats
- Author
-
Akihiro Kojima, Kunio Doi, Akira Yasoshima, Azusa Okaniwa, and Fujio Fujinami
- Subjects
Male ,Coronaviridae ,Submandibular Gland ,Salivary Gland Diseases ,Biology ,Sialadenitis ,General Biochemistry, Genetics and Molecular Biology ,Virus ,Microbiology ,Rodent Diseases ,Dacryocystitis ,Mice ,Cytopathogenic Effect, Viral ,Antigen ,Virus strain ,Animals ,Sialodacryoadenitis virus ,Cells, Cultured ,General Veterinary ,Strain (chemistry) ,Inoculation ,General Medicine ,Isolation (microbiology) ,Rats ,Microscopy, Electron ,Cell culture ,Animal Science and Zoology - Abstract
Pathogenic agents were isolated from affected salivary glands of rats with sialodacryoadenitis (SDA) by means of intercerebral inoculation to newborn mice and inoculation to primary rat kidney cell cultures. The properties of these isolates, irrespective of the isolation techniques, were in general agreement with that of SDA virus strain 681, and they were identified as SDA virus. In addition to the known properties, following characteristics were noticed: (1) Particles of SDA virus bore two different long and short surface projections. (2) Some antigenic differences were observed between the present isolate 930-10 and the strain 681. (3) It was suggested that SDA virus grew better at 35 degrees C than at 31 degrees, 33 degrees, 37 degrees or 39 degrees C. (4) SDA virus did not propagate in DBT cells.
- Published
- 1980
- Full Text
- View/download PDF
39. Multiplication of canine coronavirus in CRFK cells
- Author
-
Azusa Okaniwa, Akihiro Kojima, and Hiroshi Takada
- Subjects
Syncytium ,biology ,medicine.diagnostic_test ,Coronaviridae ,viruses ,virus diseases ,Canine coronavirus ,General Medicine ,Golgi apparatus ,Kidney ,biology.organism_classification ,Immunofluorescence ,Virology ,Molecular biology ,Virus ,Cell Line ,symbols.namesake ,Dogs ,Multiplicity of infection ,Cytopathogenic Effect, Viral ,Antigen ,Cytoplasm ,medicine ,symbols ,Animals - Abstract
Canine coronavirus produced CPE in CRFK cells without any blind passages. Syncytium formation was one of the most prominent cytopathic changes after inoculation at a low multiplicity of infection (MOI) of 1 TCID50/cell. At a high MOI of 50 TCID50/cell, however, rounding and detachment of the cells occurred, but no syncytium formation was found. Specific immunofluorescence and immunoperoxidase staining were confined in the perinuclear cytoplasm at 4 hr postinfection when infective titers of culture fluid began to increase. Virus titers reached their maxima of 104.2 and 105.3 TCID50/0.1ml after infection at an MOI of 1 and 50 TCID50/cell respectively. Electron microscopic observation revealed that virus particles occurred in the restricted area of the perinuclear cytoplasm, mainly at the Golgi field, in the early stage of infection. Localization of virus particles as well as positive immunofluorescence and immunoperoxidase staining for specific CCV antigen was seen in the same area of infected cells, i.e., around the centriole and Golgi complex and perinuclear cytoplasm in an indentation in the early stage of infection.
- Published
- 1986
- Full Text
- View/download PDF
40. Platelet Derived Endothelial Cell Growth Factor/Thymidine Phosphorylase Enhanced Human IgE Production
- Author
-
Shigeharu Fujieda, Hiroshi Sunaga, Akihiro Kojima, Tetsuji Takabayashi, Hideyuki Yamamoto, Myungmi Oh, Takechiyo Yamada, and Norihiko Narita
- Subjects
Vascular Endothelial Growth Factor A ,Angiogenesis ,medicine.drug_class ,Immunoglobulin E ,Monoclonal antibody ,platelet-derived endothelial cell growth factor (PD-ECGF) ,Peripheral blood mononuclear cell ,thymidine phosphorylase ,chemistry.chemical_compound ,Adjuvants, Immunologic ,medicine ,Humans ,Immunology and Allergy ,Enzyme Inhibitors ,Thymidine phosphorylase ,CD40 ,biology ,General Medicine ,Immunoglobulin Class Switching ,Molecular biology ,VEGF ,Vascular endothelial growth factor ,chemistry ,Leukocytes, Mononuclear ,biology.protein ,Angiogenesis Inducing Agents ,Interleukin-4 ,IgE ,STAT6 Transcription Factor ,Thymidine ,thymidine phosphorylase inhibitor (TPI) ,Signal Transduction - Abstract
Background Angiogenesis is one pathogenesis of allergic airway disease. Methods potent angiogenic factor is platelet-derived endothelial cell growth factor (PD-ECGF), also known as thymidine phosphorylase (TP) in the field of cancer-associated research. Vascular endothelial growth factor (VEGF) is another representative angiogenic factor. Both factors were added to the culture system of human peripheral blood mononuclear cells (PBMC) with IL-4 and anti-CD40 monoclonal antibody (mAb). Total IgE levels in the supernatants and signal transduction of stimulated PBMC were evaluated. Results Addition of PD-ECGF enhances in vitro IgE production by PBMC in the presence of IL-4 and anti- CD40 mAb, but VEGF does not enhance IgE production. Although PD-ECGF catalyzes the reversible phosphorolysis of thymidine to 2-deoxy-D-ribose-1-phosphate (2DDR), treatment of 2DDR has no effect on IgE production by human PBMC. Both IL-4 and anti-CD40 mAb induce PD-ECGF by human PBMC. Thymidine phosphorylase inhibitor (TPI), 5-chloro-6-[1- (2-iminopyrrolidinyl) methyl] uracil hydrochloride reduce IgE production via blocking of STAT6- phosphorylation. Conclusions Taken together, these results suggest TP involvement in the enhancement of IgE production and suggest that TPI is a novel strategy against IgE-related allergic disease.
- Full Text
- View/download PDF
41. ChemInform Abstract: STUDIES ON BIOLOGICALLY ACTIVE NUCLEOSIDES AND NUCLEOTIDES. IV. SYNTHESIS OF 1-β-D-ARABINOFURANOSYL-2-ARALKYLAMINO-1,4-DIHYDRO-4-IMINOPYRIMIDINE HYDROCHLORIDES
- Author
-
Ichizo Inoue, Kazuhiko Kondo, and Akihiro Kojima
- Subjects
chemistry.chemical_classification ,chemistry.chemical_compound ,Leukemia ,chemistry ,Hydrochloride ,medicine ,Biological activity ,Nucleotide ,General Medicine ,Methanol ,medicine.disease ,Medicinal chemistry - Abstract
Some 1-β-D-arabinofuranosyl-2-aralkylamino-1, 4-dihydro-4-iminopyrimidine hydrochlorides (2a-c) were prepared by the reaction of 2, 2'-anhydro-1-(β-D-arabinofuranosyl)-cytosine hydrochloride (1) with the corresponding aralkylamines (1 equiv.) in methanol. Treatment of 1 with an excess of the amines gave 1-β-D-arabinofuranosyl-2-aralkylamino-1, 4-dihydro-4-aralkyliminopyrimidine hydrochlorides (3a, b). These compounds were inactive against leukemia L-1210 and Ehrlich carcinoma in mice.
- Published
- 1979
- Full Text
- View/download PDF
42. Electron microscopic findings on epithelial cells of Lieberkühn's crypts in canine parvovirus infection
- Author
-
Akira Yasoshima, Azusa Okaniwa, Akihiro Kojima, and Kunio Doi
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Colon ,viruses ,Feline panleukopenia ,Virus ,Epithelium ,Parvoviridae ,Dogs ,Ileum ,medicine ,Animals ,Dog Diseases ,Intestinal Mucosa ,Electron microscopic ,biology ,Canine parvovirus infection ,Ground substance ,General Medicine ,biology.organism_classification ,Molecular biology ,Microscopy, Electron ,Cytoplasm ,Virus Diseases ,Lieberkühn's crypts ,Lumen (unit) - Abstract
Electron microscopic observation was carried out on epithelial cells of Lieberkuhn's crypts in the natural case of canine parvovirus infection. The replication of virions was revealed in the nuclei of the lining epithelial cells, as demonstrated in feline panleukopenia. In cells seemingly in the early stage of infection, virus particles 18 to 20 nm in diameter were scattered in swollen nuclei. In rather severely infected cells, the nuclei were considerably atrophic with a marked margination of chromatin granules and occupied with fine fibrillar masses and virion clusters. The nuclei of epithelial cells desquamated into the lumen were shown to have compact crystalline arrays of virions. Virions were observed also in the cytoplasm, being either membrane-associated or free in the ground substance.
- Published
- 1982
43. Case report on mixed infection of canine parvovirus and canine coronavirus--electron microscopy and recovery of canine coronavirus
- Author
-
Azusa Okaniwa, Akira Yasoshima, Fujio Fujinami, Akihiro Kojima, Hiroshi Takada, and Kunio Doi
- Subjects
biology ,Coronaviridae ,Coronaviridae Infections ,viruses ,Canine parvovirus ,virus diseases ,Canine coronavirus ,General Medicine ,biology.organism_classification ,medicine.disease_cause ,Virology ,Feline infectious peritonitis ,Kidney cell ,law.invention ,Parvoviridae Infections ,Dogs ,law ,Ascites ,medicine ,Animals ,Dog Diseases ,medicine.symptom ,Electron microscope ,Mixed infection ,Coronavirus - Abstract
Occurrence of coronavirus-like virions and associated degenerative changes were seen in the enterocytes of jejunal villi of a mongrel dog which had been diagnosed first as canine parvoviral disease from virological and pathological examinations. A cytopathic agent was isolated in dog kidney cell cultures from intestinal contents of the present case. The isolate, Toda strain, had morphological and physicochemical properties in common with the viruses of the coronavirus group. Toda strain was neutralized by ascites obtained from a cat with feline infectious peritonitis. Thus the case was diagnosed precisely as the mixed infection of canine parvovirus and canine coronavirus.
- Published
- 1983
44. An extraskeletal osteosarcoma in an aged rat
- Author
-
Yoshio Minato, Kazunori Imaizumi, Hiroshi Takada, Akihiro Kojima, Takaaki Yamamura, Azusa Okaniwa, Isao Wada, and Masakazu Takeshita
- Subjects
Male ,Pathology ,medicine.medical_specialty ,Extraskeletal Osteosarcoma ,Osteosarcoma ,business.industry ,Age Factors ,Rats, Inbred Strains ,Soft Tissue Neoplasms ,General Medicine ,Rats ,Rodent Diseases ,Animals, Laboratory ,Medicine ,Animals ,business ,Aged rat - Published
- 1988
45. Pleomorphic liposarcoma in an aged rat
- Author
-
Azusa Okaniwa, Hiroshi Takada, Isao Wada, Masakazu Takeshita, Hisashi Yamanaka, Yoshio Minato, and Akihiro Kojima
- Subjects
Male ,Round cells ,Pathology ,medicine.medical_specialty ,Aging ,Endoplasmic reticulum ,Lipid metabolism ,Rats, Inbred Strains ,General Medicine ,Liposarcoma ,Biology ,Pleomorphic Liposarcoma ,Rats ,medicine.anatomical_structure ,Lipid droplet ,Abdominal Neoplasms ,Abundant cytoplasm ,medicine ,Animals ,Mesentery ,Aged rat - Abstract
Histopathological observations were made on pleomorphic liposarcoma found in the omentum and mesentery of a 68-week-old rat. The tumor consisted of two types of tumor cells; round cells that had abundant cytoplasm with a clear large nucleus and spindle-shaped, slender cells with dark oval nuclei. Some round cells contained features suggesting ongoing lipid synthesis in the dilatated cistern of the rough endoplasmic reticulum. Both types of cells had various sizes of lipid droplets with no limited membrane.
- Published
- 1986
46. An attempt to establish experimental dysenteric bacilli cystitis
- Author
-
Akihiro Kojima, Yoshishige Kawano, Sadashige Sakuma, and Shigemi Awataguchi
- Subjects
Bacilli ,Guinea Pigs ,Urinary Bladder ,Keratoconjunctivitis ,Chick Embryo ,medicine.disease_cause ,Kidney ,Microbiology ,Cornea ,Cystitis ,medicine ,Escherichia coli ,Animals ,Shigella ,Dysentery, Bacillary ,biology ,Virulence ,business.industry ,Inoculation ,Dysentery ,General Medicine ,medicine.disease ,biology.organism_classification ,Culture Media ,Female ,business ,Conjunctiva - Abstract
It was demonstrated that transurethral inoculation of the freshly isolated strains of Shigella into guinea pigs led to an acute severe dysenteric cystitis, resulting in the death of a majority of them, whereas stock cultures of the same species did not.
- Published
- 1969
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.