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Biomedical subjects

H Akamatsu

Publications and source records attributed to H Akamatsu.

At least 37 records · Page 2Linked to original sources
PubMed2001

Spontaneous loss of a conditionally dispensable chromosome from the Alternaria alternata apple pathotype leads to loss of toxin production and pathogenicity.

The Alternaria alternata apple pathotype causes Alternaria blotch of susceptible apple cultivars through the production of a cyclic peptide, host-specific toxin, AM-toxin. We recently cloned a cyclic peptide synthetase gene, AMT, whose product catalyzes the production of AM-toxin and showed that it resides on chromosomes of 1.8 Mb or less, depending on the A. alternata apple pathotype strain. Reverse transcriptase (RT)-PCR, using primers specific to AMT, on laboratory sub-cultured strains previously shown to produce AM-toxin, identified one isolate that did not express the gene. A leaf necrosis bioassay confirmed an AM-toxin-minus phenotype. However, an original isolate of this strain which had not undergone sub-culture gave a positive result by both RTPCR and bioassay. Contour-clamped homogeneous electric field electrophoresis and Southern hybridization demonstrated the loss of a 1.1-Mb chromosome in the non-toxin-producing isolate. Since this chromosome can be entirely lost without affecting growth, but is necessary for pathogenicity, we propose it is a conditionally dispensable chromosome.

Alternaria↗
PubMed2001

Effect of palmitic acid on neutrophil functions in vitro.

BACKGROUND: It has been shown that in acne comedones the proportion of linoleic acid is markedly decreased, while palmitic acid is significantly increased. We previously reported that the decreased proportion of linoleic acid, which markedly suppresses neutrophil reactive oxygen species (ROS) generation and phagocytosis, contribute to the worsening of acne inflammation. The aim of this study was to examine the effect of palmitic acid on neutrophil functions in vitro. METHODS: We investigated the effect of palmitic acid on inflammatory parameters such as neutrophil chemotaxis, phagocytosis, and ROS generation. Reactive oxygen species generation in a cell-free, xanthine-xanthine oxidase system was also assessed. The species examined were superoxide radical anion (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (OH.). RESULTS: Palmitic acid significantly decreased H2O2 generation both by neutrophils and in the xanthine-xanthine oxidase system, while neutrophil chemotaxis and phagocytosis as well as O2- and OH. generation by both systems were not markedly affected in the presence of palmitic acid. CONCLUSIONS: The present study suggests that palmitic acid may be involved in the pathogenesis of acne inflammation from a standpoint of oxidative tissue injury.

Chemotaxis, Leukocyte↗
PubMed2001

Immunohistological analysis of thymoma by molecules differentially expressed in the thymic cortex and medulla, and its application in the differential diagnosis of thymoma from esophageal and lung cancer.

The purpose of this study was to verify the WHO classification of thymic tumors using immunohistological methods, and to discover whether these methods can be applied to differentiate thymoma from squamous cell carcinoma (SCC) of the esophagus and the lung. Twenty-nine thymoma cases were classified according to WHO and were then immunohistologically examined for the positivity of these molecules. All thymoma cases investigated in this study were positive for IL-1R, and most of them were also positive for bek. In contrast, UH-1 was highly positive in B1 and B2 type thymomas, but negative or weakly positive in A, AB and B3 type thymomas. Twelve esophageal cancers and 21 lung cancers were also examined for the positivity of the same molecules. All esophageal cancers were negative for UH-1. Three of 12 cases were weakly positive for IL-1R, and four of these 12 cases were also weakly positive for bek. Twelve of 21 lung cancer cases were adenocarcinomas, all of them negative for IL-1R, bek and UH-1. Nine of 21 lung cancer cases were SCCs, all of them negative for UH-1. Eight of nine SCC cases were strongly positive for IL-1R, while seven of these were weakly positive for bek. We conclude that the WHO classification of thymic tumors is still valid as demonstrated by immunohistological analysis and that the positivity of UH-1, IL- 1R and bek might be helpful in differentiating thymoma from SCC of the esophagus and the lung.

Adenocarcinoma↗
PubMed2001

Correlation of tissue and plasma RANTES levels with disease course in patients with breast or cervical cancer.

The beta-chemokine RANTES was measured in plasma in 43 patients with breast cancer and in 23 patients with cervical cancer, and the RANTES content in primary tumors, tumor metastatic to lymph nodes, and clinically normal skin or pelvic mucosa was measured. In addition, plasma levels were determined in all of the patients for the platelet-derived chemokine beta-thromboglobulin (beta-TG) and for IFN-gamma, interleukin (IL)-2, IL-4, IL-5, and IL-10, along with serum IgE levels and blood eosinophils. Plasma RANTES levels were found to be higher in order of stages IV, III, II, and I of each cancer except for stage I. A marked increase in plasma RANTES level (> 10,000 pg/ml) was found in 27% of patients with progressive malignancy but in none of those in clinical remission. The platelet RANTES content was correspondingly decreased in those patients with increased plasma RANTES levels. Beta-TG showed a pattern similar to RANTES both in plasma and platelets, but with much less dramatic differences between patients with different stages of disease. Other allergic parameters, IgE, eosinophils and plasma IFN-gamma, IL-2, -5, and -10, were not elevated in the cancer patients. The RANTES content was markedly elevated in the primary tumor and metastatic lesions (lymph node or skin) from all of the patients with breast or cervical cancer, irrespective of the plasma RANTES level. In addition, in patients with progressive breast or cervical cancer, but not in patients thought to be cured of these tumors, the RANTES content was markedly increased in clinically normal tissue taken from near the operative site several months postoperatively, as well as in intact skin or mucosa taken perioperatively near the excised tumor. This study suggests an as-yet-undefined but important role played by RANTES in carcinogenesis, as well as the possibility that a RANTES assay in tissue surrounding a tumor or postoperative tumor site may help predict prognosis in these patients.

Adult↗
PubMed2001

[A case of giant dumbbell shaped schwannoma with massive pleural effusion].

A 58-year-old female was admitted to the hospital complaining of dyspnea. The chest roentgenogram and CT scan revealed a large mediastinum tumor and massive pleural effusion in the right hemithorax. The diagnosis of lung cancer with carcinomatous pleulitis was performed through thoracocentesis an treatment of chemotherapy was chosen. After 6 years, she was admitted again to the hospital complaining of dull pain in the right leg. Chest CT scan and MRI showed a giant dumbbell shaped mass connected to the spinal canal. The tumor was larger than that of six years ago and diagnosed as schwannoma by CT-guided pericutaneous needle biopsy. At operation, hemilaminectomy of Th 1-3 was done first, and total tumor resection was performed through posterolateral thoracotomy. Intrathoracic adhesion was severe and it was difficult to control air leakage from the lung, thoracoplasty was performed.

Female↗
PubMed2001

[A case of pulmonary metastasis of malignant fibrous histiocytoma with left atrial infiltration via the pulmonary vein].

We report a case of a woman who at age 58 had an operation on the right femur for malignant fibrous histiocytoma (MFH). At age 63, a chest X-ray examination disclosed a tumor shadow, for which we suspected metastasis from the MFH. Chest computed tomography showed that the tumor had infiltrated to the left atrium via the pulmonary vein. We operated on the patient, first dividing the arterial supply to the lower lobe, and then opening the pericardium. We blocked the lower pulmonary vein and left atrium with a Cooley-Dera clamp and resected the tumor. The tumor was polypoid and had invaded the left atrium. Fifteen months after this lung surgery, the patient was diagnosed with a brain tumor, which was resected. Invasive primary lung cancer to the left atrium via the pulmonary vein is common, but metastasis from a sarcoma such as MFH to the left atrium via the pulmonary vein is extremely rare.

Female↗
PubMed2000

Evidence for degradation of cytokines in the serum of patients with atopic dermatitis by calcium-dependent protease.

Changes in the levels of cytokines in the circulating blood and skin have been reported in patients with atopic dermatitis (AD). We determined IFN-gamma, IL-2, IL-4, IL-5 and IL-10 in both the serum and plasma of 45 AD patients and 20 healthy donors. Since differences in the levels of these cytokines between serum and plasma were found, the roles of Ca2+ and proteolytic enzymes were examined. Levels of IL-2 and IL-10 were measured in citrated plasma to which various amounts of CaCl2, protease inhibitors, and proteases had been added. All cytokine determinations were carried out using a standard ELISA. The plasma levels of IFN-gamma, IL-2, and IL-5 were significantly elevated, but the serum levels of these cytokines were not significantly changed. The levels of IL-2 in the plasma of the AD patients averaged 4.25-fold higher than in the serum of the AD patients, and 2.5-fold higher than in the plasma of healthy controls (P < 0.001). CaCl2 produced a dose-dependent decrease in IL-2 and IL-10 in citrated plasma. The protease inhibitors PMSF, aprotinin and leupeptin produced a dose-dependent increase in measurable levels of IL-2 and IL-10 in plasma. A decrease in IL-2 levels was also seen in CaCl2-supplemented serum-free medium, and this was accentuated by the addition of the proteases thrombin, trypsin, chymotrypsin and elastase. These findings suggest that although significant changes in cytokine levels have been reported not to occur in circulating blood but have been reported to occur in the skin of AD patients both in vivo and in vitro, cytokines can indeed also be found to be elevated in circulating blood when assessed carefully by statistically valid methods. Further, it is suggested that during the preparation of serum, some circulating cytokines are degraded by calcium-dependent proteases, and that Ca2+ itself can also affect the measurement of cytokines. The measurement of circulating cytokines needs to be carefully reassessed.

Adolescent↗
PubMed2000

Protective role of copper, zinc superoxide dismutase against UVB-induced injury of the human keratinocyte cell line HaCaT.

On the basis of our recent observation that copper, zinc-superoxide dismutase and manganese-superoxide dismutase change differently following a single exposure to ultraviolet-B irradiation in the human keratinocyte cell line HaCaT, we have examined the possible role of endogenous copper,zinc-superoxide dismutase or manganese-superoxide dismutase against ultraviolet-B-induced reactive-oxygen- species-mediated keratinocyte injury in vitro. To evaluate the individual defensive roles of copper, zinc-superoxide dismutase and manganese-super-oxide dismutase, we treated HaCaT cells with diethyldithiocarbamate, a chelating agent of ionic copper that inactivates copper,zinc-superoxide dismutase activities, tumor necrosis factor alpha, which enhances manganese-superoxide dismutase levels, or transforming growth factor beta1, which inhibits manganese-superoxide dismutase levels. After the treatment with each reagent, HaCaT cells in the three different conditions were exposed to a single dose of ultraviolet-B irradiation. We assessed ultraviolet-B-induced cytotoxicity by measuring both lactate dehydrogenase leakage and cell viability using trypan blue dye exclusion assay. The lactate dehydrogenase leakage in the supernatant from damaged HaCaT cells whose copper,zinc-superoxide dismutase levels were inactivated by diethyldithiocarbamate was significantly increased and the cell viability was significantly decreased in comparison with untreated groups at 8 and 24 h after ultraviolet-B irradiation. On the other hand, the lactate dehydrogenase release and cell viability for HaCaT cells whose manganese-superoxide dismutase levels were enhanced by tumor necrosis factor alpha or inhibited by transforming growth factor beta1 showed no significant difference from untreated groups. Furthermore, increased production of intracellular peroxides in HaCaT cells treated with diethyldithiocarbamate was observed by flow cytometric analysis at 8 h after ultraviolet-B irradiation. These results suggest that copper,zinc-superoxide dismutase may play a primary protective role against ultraviolet-B-induced injury of the human keratinocyte cell line HaCaT.

Animals↗
PubMed2000

Thoracoscopic lung resection for extremely small nodular lesions using simultaneous intraoperative real-time computed tomography.

Because the localization of small lung nodules at thoracoscopic resection is sometimes difficult, we have employed intraoperative real-time computed tomography (CT). Two patients with lung nodules less than 1 cm in diameter were treated using this technique. Detection of the lesion using CT and thoracoscopic resection is performed simultaneously in the interventional radiological CT examination room. After induction of general anesthesia with one-lung ventilation, the patient is placed in the lateral position. The lung nodule is detected using real-time CT and grasped with forceps. Thoracoscopic resection of the nodule is performed in the usual fashion. Frozen section examination is immediately performed to decide on further therapy.

Adenocarcinoma↗
PubMed2000

The effect of phosphodiesterase III inhibitors on human neutrophil function.

OBJECTIVES: Neutrophils play an important role in ridding the body of bacteria and cellular debris. Several neutrophil functions are thought to be regulated by inotropes that increase cellular levels of cyclic adenosine monophosphate, including phosphodiesterase (PDE) inhibitors. We have investigated the effect of amrinone, milrinone, and olprinone, type III PDE (PDE-III) inhibitors, on several human neutrophil functions. DESIGN: Prospective in vitro study. SETTING: Academic research laboratory. SUBJECTS: Neutrophils isolated from 12 healthy adult volunteers. INTERVENTIONS: We measured chemotaxis, phagocytosis, reactive oxygen species production, intracellular calcium ion concentration, and cyclic adenosine monophosphate levels in neutrophils in the absence and the presence (at clinically relevant concentrations, 10 times, and 100 times those concentrations) of amrinone, milrinone, or olprinone. We also measured reactive oxygen species production under the same condition in a xanthine-xanthine oxidase system MEASUREMENTS AND MAIN RESULTS: None of the PDE-III inhibitors impaired neutrophil chemotaxis or phagocytosis. Amrinone at clinically relevant or higher concentrations and milrinone at high concentrations reduced superoxide, hydrogen peroxide, and hydroxyl radical levels in neutrophils and in the xanthine-xanthine oxidase system. Olprinone did not have those effects, and none of the PDE-III inhibitors had an effect on intracellular calcium ion concentration or cyclic adenosine monophosphate production in neutrophils stimulated by a chemotactic factor. CONCLUSIONS: The ability of amrinone to scavenge reactive oxygen species at clinically relevant concentrations while not affecting neutrophil function suggests that the PDE inhibitor can be used without detriment in severely ill patients.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2000

Clinicopathological analysis of premature infants treated with artificial surfactant.

OBJECTIVE: Our aim was to obtain new information about the relationship between infant responses to surfactant replacement therapy and histopathological changes in vital organs. STUDY DESIGN: To accomplish this, the autopsy findings and clinical backgrounds of 41 very low birth weight infants (gestational week 25.6 +/- 2.3; birth weight 806.4 +/- 251.6g) who had died after receiving surfactant replacement therapy were reviewed, and those who responded to therapy were compared with those who did not. Responders were infants in whom the required FiO(2) declined by > 20% or mean airway pressure declined by > 20% within six hours of instilling surfactant (n=18); non-responders were infants who did not meet those criteria (n=23). RESULT: Gestational age, birth weight and time at treatment were similar in responders and non-responders, but survival was significantly longer in responders. The incidences of hyaline membrane disease, pulmonary interstitial emphysema, hemorrhagic necrosis and parenchymal degeneration of the liver and kidney were all higher in non-responders, whereas the incidences of bronchopulmonary dysplasia and pneumonia were higher in responders. Prior to treatment, acidosis and hypothermia were significantly more severe in non-responders, and perinatal complications, such as fetal distress and intrauterine infection, were observed more often in non-responders. Substantial degradation of vital organs had already occurred during the early post-natal or intrauterine life of the non-responders, which would be expected to interfere with the clinical response to instilled surfactant. CONCLUSION: It is anticipated that in the future improved monitoring of immature fetuses will be indispensable to improve intrauterine fetal management and to achieve better control over the timing and mode of delivery.

Gestational Age↗
PubMed1999

Results of surgery for primary lung cancer based on the new international staging system.

OBJECTIVES: This study clarified the results of surgery for primary lung cancer based on the new international staging system. BACKGROUND: On December 1997, the Japan Lung Cancer Society adopted a new TNM staging system which had already received international recognition. SUBJECTS AND METHODS: The subjects of this study were 1062 consecutive previously untreated patients who underwent pulmonary resection for primary non-small cell lung cancer between January 1975 and December 1992. RESULTS: The postoperative 5-year survival rate for all patients was 58.5%. Pathological staging demonstrated a survival rate which was 73.2% in stage I, 46.8% in stage II, 26.7% in stage III, and 20.0% in stage IV. In the staging subgroups, the survival rate was 79.6% in stage IA, 62.4% in stage IB, 62.2% in stage IIA, 42.0% in stage IIB, 26.9% in stage IIIA, and 26.3% in stage IIIB. Concerning the pm patients, the survival rate was 20.2% in pm1 and 20.0% in pm2, while the survival rate of the patients with N0 was 45.7% in pm1 and 40.0% in pm2. CONCLUSIONS: A significant difference in the 5-year survival rate was recognized between the new stages IA and IB, and between the new stages IIA and IIB. When pm patients are diagnosed without lymph node metastasis, the opportunity for resection should not be lost.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

Molecular karyotypes for Alternaria plant pathogens known to produce host-specific toxins.

There are at least ten plant diseases caused by Alternaria species in which host-specific toxins (HSTs) are responsible for fungal pathogenicity. Of these HST-producers, seven are considered distinct pathotypes of the species Alternaria alternata, and the remaining three are among other species of pathogenic Alternaria. Inter- and intra-specific variation among Alternaria taxa, including HST-producers, was determined by electrophoretic karyotyping using pulsed-field gel electrophoresis. A. alternata including seven pathotypes of A. alternata and eight non-pathogenic strains had 9-11 chromosomal bands with estimated sizes ranging from 0.4 to 5.7 Mb. In contrast, Alternaria species that are morphologically distinct from A. alternata had 8-10 bands with sizes between 0.9 and 5.7 Mb. Estimated genome sizes of A. alternata and other Alternaria species ranged from 28.8 to 33.6 Mb and 25.1 to 30.7 Mb, respectively. Other species of pathogenic Alternaria were difficult to differentiate from A. alternata on the basis of chromosome-size polymorphisms alone, but Southern analysis using rDNA as a probe could, in some cases, differentiate between them. These results were cytologically confirmed by 4',6-diamidino-2-phenylindole (DAPI) staining and fluorescence in situ hybridization with a rDNA probe for mitotic metaphase chromosomes prepared by the germ-tube burst method.

Alternaria↗