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Biomedical subjects

K Hamada

Publications and source records attributed to K Hamada.

At least 217 records · Page 12Linked to original sources
PubMed1997

Characteristics of the clinical findings in patients with idiopathic thrombocytopenic purpura who are positive for anti-phospholipid antibodies.

It has been reported that anti-phospholipid antibodies are detected in some patients with idiopathic thrombocytopenic purpura (ITP). To study the significance of determination of anti-phospholipid antibodies in patients with ITP, clinical and laboratory findings were compared between patients whose sera were positive for these antibodies (Group A) and non-positive patients (Group B). Anti-cardiolipin antibody (aCL) was determined by enzyme-linked immunosorbent assay and lupus anticoagulant (LA) was determined by activated partial thromboplastin time (aPTT) and thromboplastin time inhibition test. Seven out of 27 cases of ITP belonged to Group A and 3 of the 7 were confirmed to have anti-phospholipid antibody syndrome (APS). There was a tendency for habitual abortion, and thrombosis, megakaryocytes in the bone marrow and platelet-associated IgG (PAIgG)-positive cells were more frequent in Group A than in Group B. However, it was difficult to discriminate APS from ITP alone, when there were no symptoms or signs of APS. Therefore, measurement of anti-phospholipid antibodies in ITP was thought to be useful for the differential diagnosis of APS and subsequently for the prevention of thrombosis.

Adolescent↗
PubMed1997

Effect of repeated exercise on urinary 8-hydroxy-deoxyguanosine excretion in humans.

The purpose of this study was to investigate the effect of repeated exercise on oxidative damage to DNA in 10 well trained long distance runners who participated in an 8-day training camp. The average running distance during the camp was 30 +/- 3 km/day. The amount of urinary 8-hydroxy-deoxyguanosine (8-OHdG) excretion was used to estimate the oxidative DNA damage. Urine samples were collected for both a 3-day control period as well as throughout the camp. Blood samples were drawn after overnight fasting both before and after the camp. Urinary 8-OHdG excretion was significantly increased during the camp compared to the control period (265.7 +/- 75.5 vs. 335.6 +/- 107.4 pmol/kg/day, P < 0.05). The content of 8-OHdG in the lymphocyte DNA on the day after finishing the camp did not differ from that before the camp. Plasma TBARS, LDH, CK, CK-MB, and myoglobin significantly rose after the camp (P < 0.05). The plasma beta-carotene levels tended to rise after the camp, while the plasma alpha-tocopherol levels increased significantly after the camp (P < 0.05). These results indicate that repeated exercise augments oxidative stress and the DNA is also injured by exercise-induced reactive oxygen species. However, the oxidative damage to DNA is not accumulated by consecutive exercise, although it is sustained as long as the exercise is repeated.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

Effect of endurance exercise on the tissue 8-hydroxy-deoxyguanosine content in dogs.

The purpose of this study was to investigate the effect of endurance exercise on both the tissue and lymphocyte 8-hydroxy-deoxyguanosine (8-OHdG) content. Six dogs ran on a treadmill for 7 hours. Another six dogs were assigned to a sedentary control group. The exercised dogs were sacrificed immediately after exercise and the counterpart of the sedentary group was also sacrificed at the same time. The brain, lung, liver, spleen, kidney, jejunum, colon, diaphragm, heart, splenius muscle, and the medial and lateral portion of gastrocnemius muscle samples were then collected. Lymphocytes were sampled before and after exercise in the exercised dogs. The 8-OHdG content of lymphocyte DNA was found to significantly decrease after exercise (0.57 +/- 0.19 vs 0.33 +/- 0.10/deoxyguanosine (dG) x 10(5), P < 0.05). The colon was the only tissue which showed a significant decrease in the content (0.83 +/- 0.24 vs 0.54 +/- 0.15/dG x 10(5), P < 0.05). No tissue except for the colon showed any significant changes after exercise. These results therefore indicate that, immediately after endurance exercise, an augmented repair mechanism might thus play a role in the decrease of 8-OHdG in the lymphocytes and the colon, while the 8-OHdG generation might be counterbalanced by its repair in other tissues.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1997

Effect of the anticholinergic drug with calcium antagonistic activity, (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, on lower urinary tract function in decerebrated dogs.

NS-21 ((+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, CAS 129927-33-4) is a novel compound designed for the treatment of bladder dysfunction. The effects of NS-21 and its active metabolite, RCC-36 ((+/-)-4-ethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride), on the urodynamics of decerebrated dogs are reported. Dogs were decerebrated at the precollicular-postmamillary level and the urodynamic effects of intravenously administered NS-21, RCC-36, and various reference drugs were compared by cystometry. NS-21 (0.3-1 mg/kg) and RCC-36 (0.1 mg/kg) caused an increase in bladder capacity without affecting the micturition pressure or residual volume, and thus caused a significant increase in functional bladder capacity. Oxybutynin caused a dose-dependent increase in bladder capacity at 0.1 mg/ kg and higher doses; however, the associated decrease in micturition pressure resulted in a significant increase in residual volume and a decrease in functional bladder capacity. These effects of oxybutynin were similar to those of atropine. Propiverine (0.1-10 mg/kg) and terodiline (0.1-10 mg/kg) caused no significant increase in bladder capacity. In conclusion, in decerebrated dogs, NS-21 and RCC-36 increased the bladder capacity without increasing the residual volume. NS-21 thus had more favorable therapeutic effects than any of the reference drugs tested and is therefore a promising candidate drug for the treatment of pollakiuria and urinary incontinence.

Animals↗
PubMed1997

Effect of the anticholinergic drug with calcium antagonistic activity, (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, on lower urinary tract function in rhesus monkeys.

NS-21 ((+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, CAS 129927-33-4) and its active metabolite, RCC-36 ((+/-)-4-ethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride), have both anticholinergic and calcium antagonistic activities. NS-21 is under development for the treatment of bladder dysfunction. This study was designed to compare the effects of NS-21 and RCC-36 on the bladder function of monkeys with the effects of various reference drugs. Male rhesus monkeys were anesthetized with a mixture of enflurane and nitrous oxide, a transurethral catheter was inserted into the urinary bladder from the external urethral orifice, and cystometrograms were recorded. Drugs were administered intravenously. NS-21 at doses of 0.3 and 1 mg/kg caused an increase in bladder capacity without affecting the micturition pressure. RCC-36 also caused an increase in bladder capacity, but it was accompanied by a significant decrease in micturition pressure. Oxybutynin, atropine and verapamil all caused decreases in micturition pressure at doses which caused an increase in bladder capacity. Of the drugs examined, only NS-21 caused an increase in the bladder capacity of rhesus monkeys without affecting the micturition pressure. This drug is therefore a promising candidate for the clinical treatment of pollakiuria and urinary incontinence.

Animals↗
PubMed1997

[Autopsy findings of retroperitoneal cystic tumor and peliosis hepatis in lymphangiomyomatosis].

A 40-year-old woman who worked as a nurse and had suffered from progressive exertional dyspnea for about 14 years underwent open lung biopsy with surgical treatment for pneumothorax. The diagnosis was lymphangiomyomatosis and she was treated with danazol to suppress ovarian function. Her condition improved temporarily, but she died of respiratory failure when she was 47 years old. The survival time after the onset of respiratory symptoms was 21 years, and after the biopsy it was 8 years. At autopsy a retroperitoneal cystic tumor was found (9 x 7 x 5 cm), which had been evident clinically. Histologic examination showed that the tumor was an extrapulmonary manifestation of the lumphangiomyomatosis lesion. Some paraaortic lymph nodes has similar lesions. Aggregates of small red spots were seen on acute surface of the liver. These were diagnosed as peliosis hepatis, they may have been caused by the danazol.

Danazol↗
PubMed1997

Cytotoxic effects of recombinant adenovirus p53 and cell cycle regulator genes (p21 WAF1/CIP1 and p16CDKN4) in human prostate cancers.

PURPOSE: Overexpressing or restoring the basal levels of tumor suppressor genes in cancer cells can suppress tumorigenicity of cancer cells. In this communication, we compared tumor suppressive activities of three well-defined tumor suppressive genes (p53, p21WAF1/CIP1, and p16CDKN2) delivered individually to prostate cancer cells with adenoviral vector (Ad). MATERIALS AND METHODS: Efficacy of growth inhibition by recombinant adenoviruses bearing p53, p21WAF1/CIP1, or p16CDKN2 (Ad5CMV-p53, Ad5CMV-p21, Ad5CMV-p16) genes were tested in vitro on androgen-dependent (LNCaP) and androgen-independent (C4-2, DU-145, and PC-3) human prostate cancer cells, ex vivo and in vivo on PC-3 tumor. RESULTS: Ad5CMV-p53 was observed to exert the greatest growth inhibitory action on all of the cell lines tested; inhibition appeared to be cytolytic. In comparison to control Ad5CMV-PA added samples, the growth inhibitory action of Ad5CMV-p21 and Ad5CMV-p16 appeared to be cytostatic. Ad5CMV-p53 is more effective than Ad5CMV-p16 and Ad5CMV-p21 in inhibiting the tumor "take" rate. A similar order of antitumor activity was observed when recombinant adenoviruses were injected intratumorily to previously established PC-3 tumors in vivo. CONCLUSION: p53 is the most effective tumor suppressor gene to target human prostate cancer.

Adenoviruses, Human↗
PubMed1997

[Tissue polypeptide antigen as a biological marker of malignant pleural mesothelioma].

To evaluate the role of tissue polypeptide antigen (TPA) as a biological marker of malignant pleural mesothelioma (MPM), we used immunohistochemical techniques to detect TPA in tumor cells, and we measured the content of TPA in serum from patients with MPM. In 14 of 16 patients with MPM, TPA was detected in the cytoplasm of tumor cells. Epithelial-type cells from 11 of 12 patients were stained positively (91.7%), and sarcomatous-type cells from 7 of 8 patients were stained positively (87.5%). Serum TPA levels were abnormally high in 7 of 9 patients. Two of three patients with stage-I disease had normal serum TPA levels, and all patients whose disease was at stage II or higher had abnormal serum TPA levels. Serum TPA levels increased as MPM progressed. These results suggest that the serum TPA level can be used as a biological marker of MPM.

Adult↗
PubMed1997

[Photomicrographs of a pleural biopsy specimen, showing malignant mesothelioma and necrosis--malignant pleural mesothelioma in a patient with sarcoidosis].

A 45-year-old woman was admitted to Nara Medical University Hospital because of right-sided chest pain. Both a chest X-ray film and a chest CT scan revealed bilateral hilar and mediastinal lymphadenopathy and right pleurisy. She underwent fiberoptic bronchoscopy and mediastinoscopy. Biopsy specimens of the lung and mediastinal lymph nodes showed non-caseous epithelioid cell granulomas. After on ophthalmologic examination, she was given a diagnosis of sarcoidosis with a pleural lesion and uveal involvement. The pleurisy become less severe and the lymph nodes shrank without any treatment. About one year later, she complained of right-sided chest pain again and a chest X-ray film revealed diffuse thickening of the pleural on the right side. Examination of pleural biopsy specimens revealed malignant mesothelioma. We know of no previous report from Japan of malignant pleural mesothelioma in a patient with sarcoidosis.

Biopsy↗
PubMed1997

Morphological transformation caused by a partial sequence of U5 small nuclear RNA.

My colleagues and I have reported that a small nuclear RNA, U5, can cause transformation of and chromosomal aberrations in rat fibroblast 3Y1 cells. In the study described here, I found that a partial U5 sequence, the 3' half of the first stem structure (designated RNA3S), transformed the cells morphologically at a high frequency when expressed with a poly(A) tail (RNA3S+). The transformation critically depended upon a polypurine sequence in RNA3S+. The expressed RNA3S+ was associated with polysomes. The transformed cells did not exhibit significant frequencies of chromosome aberrations when compared with control cells, suggesting that the transformation occurs without significant induction of chromosome damage. Heterogeneous subcolonies emerged in monolayers when the morphologically transformed cells were subcultured and maintained at postconfluence. Cells from subcolonies acquired the ability to form small colonies in soft agar and tumors in nude mice, suggesting that RNA3S+ can drive the cells into the neoplastic stage. RNA3S+ also conferred morphological alterations and a growth advantage and decreased levels of fibronectin protein synthesis in human HeLa cells, confirming the transforming potential of the RNA. RNA3S+ transformation may therefore be a useful model system for studying a transformation process.

Animals↗
PubMed1997

[Apoptosis in infectious mononucleosis].

Apoptosis of lymphocytes in infectious mononucleosis (IM) was studied. Apoptotic cells (APCs) were defined by morphological characteristics, such as nuclear fragmentation, undergoing apoptosis. Among 10 of 27 IM patients (37.0%) APCs > or = 3 per 500 peripheral white blood cells were observed on admission, but not in normal individuals. Sequential changes of proportions of both APCs and atypical lymphocytes (examined in 2 cases) showed a similar pattern, although APCs began to appear somewhat later and peak level of APCs were lower in comparison with those of atypical lymphocytes. APCs were positive for both anti-T cell and anti-Fas antigen monoclonal antibodies. Fas-positive cells were frequent in the early stage of IM, and returned to the normal range with the decrease of atypical lymphocytes. Sequential analyses of DNA fragmentation, done in one case, revealed that DNA fragmentation appeared with increase of APCs and disappeared with the decrease of APCs. These results suggest that apoptosis of T-cells in IM participates in the reconstitution of a proportion of lymphocytes disturbed by EB virus.

Apoptosis↗
PubMed1997

[Effect of cessation of erythromycin therapy on diffuse panbronchiolitis].

The effect of cessation of erythromycin (EM) therapy against diffuse panbronchiolitis was studied. Nine cases were examined. After cessation of EM therapy, the manifestations of disease were stable in five cases, but worsened in the other four. In the former five, the period from the onset of disease until EM therapy began was relatively short; when EM therapy was stopped the manifestations of disease had almost completely disappeared and chest roentgenography revealed resolution of diffuse, small, nodular opacities without remarkable bronchiectasis. In contrast, in the latter four cases, the clinical manifestations of disease did not disappear, and chest-roentgenographic evidence of bronchiectasis was common before the cessation of EM therapy. In conclusion, EM therapy for diffuse panbronchiolitis may be stopped if the clinical manifestations of disease (especially purulent sputum) disappear, if diffuse, nodular opacities resolve almost completely and if there is no evidence of bronchiectasis.

Adolescent↗
PubMed1997

[Percutaneous vertebroplasty for osteolytic metastasis: a case report].

Percutaneous vertebroplasty is a radiologically guided therapeutic procedure that consists of percutaneous injection of surgical cement into a vertebral osteolytic metastatic lesion. This procedure has the advantage of providing rapid pain relief and bone strengthening. We report a 46-year-old male patient with osteolytic L3 vertebral metastasis from lung adenocarcinoma treated by percutaneous vertebroplasty under CT and fluoroscopic guidance. After this treatment, definite pain relief and stabilization of the vertebra were achieved. Vertebroplasty for osteolytic metastasis may be a minimally invasive procedure that provides immediate, long-term pain relief and contributes to spinal stabilization.

Adenocarcinoma↗
PubMed1997

[Application of long PCR method to detection of mitochondrial DNA deletions in mitochondrial encephalomyopathies].

In 1994, Barnes found the new method "long PCR method" where over 10 kb DNA was easily amplified, compared with conventional PCR method in which only a few kb DNA was amplified. He devised the new enzyme in this system which included Taq DNA polymerase plus a little amount of 3'-->5' exonuclease activity (proofreading activity). We tried to apply this method to detect mitochondrial DNA deletions in mitochondrial encephalomyopathies. We detected mtDNA deletions easily, however, we could not quantify mtDNA deletions. This method can be performed within one day, compared with about 1 week required to perform Southern blotting and/or several sets of conventional PCR. Although Southern blotting is needed for quantifying mtDNA deletions, this method will become a useful screening method for detecting mtDNA deletions.

DNA, Mitochondrial↗
PubMed1997

[A study on the prognosis of patients with asbestos pleurisy].

We investigated the outcome of patients with asbestos pleurisy. The mean follow-up period of 12 patients was 6.5 +/- 3.7 years. Recurrence occurred in 5 patients (41.7%). Six of the cases recurred contralateral to the original lesion, while one recurred ipsilaterally. The mean period from onset to recurrence was 2.8 +/- 2.8 years. Five of the cases ended in death, and the mean period from onset to death was 5.0 +/- 3.1 years. Two patients died from pneumonia, 2 died from respiratory failure due to progressive pleural fibrosis, and 1 died from lung cancer. One of the 2 patients with progressive pleural fibrosis had leukopenia. It has been reported that the majority of cases of asbestos pleurisy resolve spontaneously, with a good prognosis. However, because of the possible mortality associated with respiratory failure caused by progressive pleural fibrosis, it seems prudent to follow patients with asbestos pleurisy closely.

Aged↗