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Biomedical subjects

K Kondo

Publications and source records attributed to K Kondo.

At least 37 records · Page 2Linked to original sources
PubMed2003

Importance of re-examination for medulloblastoma and atypical teratoid/rhabdoid tumor.

Medulloblastoma may can be difficult to distinguish from atypical teratoid/rhabdoid tumor (AT/RT), since they resemble each other histologically. We re-examined whether AT/RT was included among cases who had been diagnosed as medulloblastoma. All of fifteen medulloblastomas (10 males and 5 females) diagnosed at the Kitasato University Hospital were collected and stained immunohistochemically. Two cases originally diagnosed as medulloblastoma were reclassified as AT/RT based on histological re-examination including immunohistochemical studies. While these two cases of AT/RT were found during infancy, only one medulloblastoma was found in infancy.Histologically, small rhabdoid cells and large, pale, bland cells were common but typical rhabdoid cells were not seen in the two AT/RTs. Gland-like structures were also seen. The tumor cells in AT/RT, but not those in medulloblastoma, were immunoreactive for vimentin, epithelial membrane antigen and smooth muscle actin. In conclusion, if a diagnosis of medulloblastoma is made histologically, it should be confirmed immunohistologically, since it is difficult to distinguish AT/RT from medulloblastoma. When appropriate treatment was specifically targeted at AT/RT it may improve the outcome.

Adolescent↗
PubMed2003

Radon concentration in indoor occupational environments in Aomori Prefecture, Japan.

The (222)Rn concentrations in indoor workplaces were measured in Aomori Prefecture, Japan, and the results are reported here. This survey was part of a program to measure background natural radiation dose rate in the prefecture where the first Japanese nuclear fuel cycling facilities are now under construction. The survey of the (222)Rn concentrations in indoor workplaces was carried out at 107 locations from 1996 to 1998. The (222)Rn concentrations were measured for approximately one year at each site with passive Rn detectors, which used a polycarbonate film for counting alpha-rays and could separate concentrations of (222)Rn from (220)Rn. Weeklong measurements of (222)Rn concentration and working level were carried out with active detectors to get the ratio of (222)Rn concentration during working hours to non-working hours as well as equilibrium factors in selected locations. Diurnal variation of (222)Rn concentration depended on building structure, air-conditioning, time of day and day of the week (week days or weekend). The (222)Rn concentration during working hours was generally lower than that in non-working hours. Although the annual average (222)Rn concentration in indoor occupational environments was higher than that in dwellings, radiation dose for Aomori Prefecture residents from Rn in the former was 14% of the total indoor dose by Rn because of the lower concentration in working hours and lower occupancy factor.

Air Pollution, Indoor↗
PubMed2003

[Surgical treatment for chronic hemorrhagic pyothorax].

A case of pleuro-pneumonectomy following arterial embolization for chronic hemorrhagic pyothorax occurring 40 years after artificial pneumothorax treatment was investigated. The patient was an 80-year-old male diagnosed with chronic hemorrhagic pyothorax after complaining of bloody sputum and difficulty breathing during exertion. The pyothorax space was conspicuously extended, and the mediastinal space was compressed. Although this condition was treated periodically over time by thoracentesis, pleuro-pneumonectomy was selected as a radical treatment. Since a large amount of hemorrhaging was expected during surgery, preoperative transcatheter embolization of the left lateral thoracic artery, the bronchial arteries and the left internal thoracic artery was performed. The amount of hemorrhaging during surgery from the feeding artery from the thoracic wall was 5,700 ml. There was an abundance of dilated blood vessels within the thickened pleura, and angiomatous structures were observed. Although symptoms improved following surgery, sudden massive hemorrhage was observed from the thoracic drain on the morning of the 79th postoperative day, and the patient died from hemorrhagic shock. Emergency thoracotomy was performed, and aortic rupture was observed on the origin of the left subclavian artery. Chronic hemorrhagic pyothorax has a peculiar pathology even for chronic pyothorax, and a large amount of hemorrhaging can be expected during surgery. Precaution must be taken for postoperative arterial hemorrhage caused by delayed inflammation.

Aged↗
PubMed2002

KL-6 as an indicator for lymphocytic interstitial pneumonia (LIP) in a human T-lymphotrophic virus type 1 (HTLV-1) carrier.

A 59-year-old woman was admitted to our hospital complaining of a productive cough, dyspnea on effort, and low-grade fever. Although chest X-rays showed no marked abnormalities, her level of serum KL-6 was extremely high. We therefore suspected the presence of interstitial pneumonia. High-resolution computed tomography (CT) scan revealed infiltrative shadows in S6 of the right lung, and her serum was positive for antihuman T-lymphotropic virus type 1 (HTLV-1) antibodies. From the clinical symptoms, radiographic findings, and histological findings, the diagnosis was probable lymphocytic interstitial pneumonia (LIP). After high-dose corticosteroid therapy, the level of serum KL-6 decreased rapidly. We conclude that KL-6 is a convenient and reliable marker for evaluating the activity of pulmonary manifestations in HTLV-1 carriers and that it is especially useful in monitoring the effectiveness of treatments.

Adrenal Cortex Hormones↗
PubMed2002

Production of active bovine cathepsin C (dipeptidyl aminopeptidase I) in the methylotrophic yeast Candida boidinii.

The heterologous production of active bovine cathepsin C (CTC; dipeptidyl aminopeptidase I) was investigated. Attempts to express CTC in Escherichia coli were hampered by formation of inclusion bodies that were partially degraded. To overcome this impediment, secretion of recombinant CTC was attempted in the methylotrophic yeast Candida boidinii. A DNA fragment encoding bovine procathepsin C was synthesized based on preferred codon usage in C. boidinii and placed downstream of the C. boidinii proteinase A signal sequence resulting in secretion of active CTC into the culture medium. The gene was expressed under the control of the methanol-inducible formate dehydrogenase gene promoter. Production levels were significantly improved by using a protease-deficient strain, changing medium composition, and by lowering the temperature of induction. When the recombinant C. boidinii was grown for 90 h in a jar-fermenter, active CTC was secreted with a yield of up to approximately 12 mg/l.

Amino Acid Sequence↗
PubMed2002

Molecular analysis of the stylar-expressed Solanum chacoense small asparagine-rich protein family related to the HT modifier of gametophytic self-incompatibility in Nicotiana.

Gametophytic self-incompatibility (GSI) systems involving the expression of stylar ribonucleases have been described and extensively studied in many plant families including the Solanaceae, Rosaceae and Scrophulariaceae. Pollen recognition and rejection is governed in the style by specific ribonucleases called S-RNases, but in many self-incompatibility (SI) systems, modifier loci that can modulate the SI response have been described at the genetic level. Here, we present at the molecular level, the isolation and characterization of two Solanum chacoense homologues of the Nicotiana HT modifier that had been previously shown to be necessary for the SI reaction to occur in N. alata (McClure et al., 1999). HT homologues from other solanaceous species have also been isolated and a phylogenetic analysis reveals that the HT genes fall into two groups. In S. chacoense, these small proteins named ScHT-A and ScHT-B are expressed in the style and are developmentally regulated during anthesis identically to the S-RNases as well as following compatible and incompatible pollination. To elucidate the precise role of each HT isoform, antisense ScHT-A and RNAi ScHT-B lines were generated. Conversion from SI to self-compatibility (SC) was only observed in RNAi ScHT-B lines with reduced levels of ScHT-B mRNA. These results confirm the role of the HT modifier in solanaceous SI and indicate that only the HT-B isoform is directly involved in SI.

Amino Acid Sequence↗
PubMed2002

Characteristic patterns of circadian variation in plasma catecholamine levels, blood pressure and heart rate variability in Type 2 diabetic patients.

AIMS: To investigate whether Type 2 diabetic patients exhibit characteristic patterns of circadian variation in plasma levels of catecholamines, blood pressure (BP) and heart rate variability (HRV). METHODS: Ten Type 2 diabetic and eight control in-patients were studied. Blood for catecholamine measurement was collected every 4 h, and non-invasive ambulatory BP and heart rate were monitored throughout the day. HRV was determined using frequency domain methods. RESULTS: Diabetic patients showed a different pattern of circadian variation in BP and HRV from that of controls, the diurnal-nocturnal differences (D-N) being significantly smaller. The mean 24-h HRV levels were reduced in diabetic subjects. The mean 24-h plasma noradrenaline level of 1.36 +/- 0.12 nmol/l in diabetic patients was significantly lower than the 2.03 +/- 0.20 nmol/l in controls (P < 0.01). In contrast, no significant difference in adrenaline levels was observed. The mean 24-h plasma noradrenaline level demonstrated a significant positive correlation with D-N in systolic BP (r = 0.49, P = 0.0153). CONCLUSIONS: The present study demonstrated distinctive patterns of circadian variation in plasma noradrenaline level, BP and HRV in Type 2 diabetic patients, associated with an abnormal circadian pattern of sympathovagal modulation.

Blood Pressure↗
PubMed2002

[Thymic carcinoma].

Thymic epithelial tumors are mainly consisted of thymoma, thymic carcinoma, and thymic carcinoid. And thymic carcinoma is very rare neoplasm. The classification of thymic carcinoma has remained a subject of controversy for many years. The outline of thymic carcinoma has been clarified by "Atlas of Tumor Pathology: Tumors of the Mediastium (AFIP)" and "Histrogical Typing of Tumours of the Thymus (WHO)" published recently. Squamous cell carcinoma is by far the most common in Japan. Thymic carcinoma is a predilection for male. The peak of age was 40-60 years. Thymic carcinoma already had contiguous invasion around neighbor organs, dissemination, and lymph node metastases or distant metastases at diagnosis. Two third of patients with thymic carcinoma performed surgery, and most of them performed adjuvant radiotherapy or chemotherapy. 5-year survival of thymic carcinoma was 33-50%. Histologic tumor type, type of tumor margin, growth pattern, nuclear atypia, necrosis and mitotic activity were correlated with survival. In this paper thymic carcinoma is reviewed mainly based on recently literatures and results obtained from a questionnaire on thymic epithelial tumors in Japan.

Adult↗
PubMed2001

Transfection of young guinea pig vestibular cells in vitro with an adenovirus vector.

This study shows distributions of lacZ-positive cells in the vestibular labyrinthine explants of young guinea pigs with mature ears. When adenovirus lacZ vectors were administered to the vestibular labyrinth following removal of the otoconial membrane, lacZ-positive cells were observed in the mesothelial cells in the perilymphatic space, in the sensory and supporting cells in the utricle and ampulla, and in the transitional and dark cells in the ampulla. When the otoconial membrane was preserved, lacZ-positive cells were not distributed in the utricular sensory epithelium. These findings suggest that adenovirus vectors can transform a variety of vestibular epithelial cells, but that it is difficult for adenovirus vectors to pass through the otoconial membrane.

Adenoviridae↗
PubMed2001

An amino acid residue whose change by mutation affects drug binding to the HERG channel.

We did the experiments to search for amino acids that affect quinidine binding to the HERG channel, and have identified an amino acid whose change by mutation affects the binding of various drugs. The residue is located at position 647 in the S6 and is not involved in the recently identified methanesulfonanilide binding pocket. The homology model of the HERG channel indicated that the residue faces toward the outside of the channel pore. We conclude that the residue at position 647 does not interact directly with drug molecules but plays an important role in keeping the binding site's high affinity for drugs.

Amino Acid Sequence↗
PubMed2001

Significance of chymase-dependent angiotensin II-forming pathway in the development of vascular proliferation.

BACKGROUND: Vascular tissues of humans and dogs contain chymase as an angiotensin II-forming enzyme. In this study, we investigated whether chymase-dependent angiotensin II formation plays a crucial role in the development of vascular proliferation in dog grafted veins. METHODS AND RESULTS: The right external jugular vein of dogs was grafted to the ipsilateral carotid artery. As a control group, the right external jugular veins in dogs that had not received grafts were used. In the chymase inhibitor-treated group, the vein was infiltrated with 10 micromol/L Suc-Val-Pro-Phe(P)(OPh)(2) and was grafted to the carotid artery. In the placebo-treated group, ACE activity in the grafted veins was significantly lower than that in the control veins up to 7 days after the operation, whereas chymase activity was increased significantly. After 7 days, the mRNA levels of collagen I, collagen III, and fibronectin, all of which are induced by an increase of angiotensin II action, were significantly increased in the grafted veins, and the intima-media ratio of the grafted veins was also increased. In the chymase inhibitor-treated group, the chymase activity in the grafted veins 7 days after the operation was suppressed to 12.1%. The elevated mRNA levels of fibronectin, collagen I, and collagen III in the grafted veins were significantly suppressed by treatment with the chymase inhibitor, and the intima-media ratio was also decreased significantly. CONCLUSIONS: We demonstrate for the first time that chymase-dependent angiotensin II formation plays an important role in the development of vascular proliferation in the grafted veins.

Angiotensin II↗
PubMed2001

Design and synthesis of a highly selective EP2-receptor agonist.

EP2-receptor selective agonist 3 was identified by the structural hybridization of butaprost 1a and PGE(2) 2a. Based on this information, a chemically more stabilized 4 was discovered as another highly selective EP2-receptor agonist, iv administration of which to anesthetized rats suppressed uterine motility, while PGE(2) 2a stimulated uterine motility.

Alprostadil↗
PubMed2001

Expression of NeuroD and TrkB in developing and aged mouse olfactory epithelium.

To better understand the roles of NeuroD, a member of the basic helix-loop-helix transcription factor family, during the differentiation of olfactory receptor neurons, we studied the expression of NeuroD in developing and aging mouse olfactory epithelium (OE). During embryonic period, NeuroD expression is confined in the basal compartment of OE. During neonatal period, NeuroD expression is detected in the middle compartment and in the basal compartment of OE. In the adult, the number of NeuroD expressing cells in the basal compartment significantly decreased, while the NeuroD-positive cells in the middle compartment was maintained throughout lifetime. This dual phase expression pattern of NeuroD suggests multiple roles of NeuroD in the neurogenesis of ORNs.

Aging↗
PubMed2001

Cerebral hemorrhage due to heparin limits its neuroprotective effects: studies in a rabbit model of photothrombotic middle cerebral artery occlusion.

We investigated the efficacy of heparin on cerebral ischemic damage in a rabbit model of middle cerebral artery (MCA) photothrombosis and in the same model, cerebral hemorrhage induced by heparin as its side effect was also investigated. Using a photothrombosis model in rabbits, 38 animals were divided into four groups, heparin low-dose I and II, heparin high-dose and vehicle. In heparin low-dose I (n=10) or II (n=7), heparin was administered for 23.5 or 22 h, respectively, starting 30 or 120 min after the start of photo-irradiation to induce thrombosis. In high-dose (n=7), heparin was administered 30 min after the start of photo-irradiation for 23.5 h. In the vehicle treated group (control), 14 animals were infused continuously with saline for 23.5 h. Heparin at low and high doses prolonged Activated partial thromboplastin time (aPTT) by about 3 and 10 times compared with control group. The results show that cerebral hemorrhage was present in all animals, gross hemorrhage was observed in one animal each of the heparin low-dose I and high-dose groups, and in three animals of the heparin low-dose II group, while no gross hemorrhage was observed in control group. In heparin low-dose I, the size of cerebral infarction was significantly (P<0.01) reduced and neurological deficits were significantly (P<0.01) improved. In contrast, in heparin high-dose, the infarct size significantly increased, especially in the cortex (P<0.0001), and neurological deficits were significantly (P<0.01) worsened. In heparin low-dose II, the size of cerebral hemorrhage significantly (P<0.001) increased compared with the control group. In conclusion, using a photothrombotic model in the rabbit MCA, we have investigated the antithrombotic benefits and hemorrhagic risks associated with heparin. Of unique feature of our model is the fact that in a single animal model, we could evaluate doses of heparin which reduce cerebral infarction and doses which can promote cerebral hemorrhage. This model can be extended to determine both benefits and risks of antithrombotic agents.

Animals↗