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Biomedical subjects

T Kuriyama

Publications and source records attributed to T Kuriyama.

At least 55 records · Page 3Linked to original sources
PubMed2000

Aberrant expression of immunoglobulin heavy chain genes in Epstein-Barr virus-negative, human immunodeficiency virus-related lymphoid interstitial pneumonia.

The two-step polymerase chain reaction (PCR) and sequencing analysis was used to analyze the immunoglobulin heavy chain variable (Ig V(H)) genes of open-chest biopsy or autopsy samples from five patients with Epstein-Barr virus-negative human immunodeficiency virus (HIV)-related lymphoid interstitial pneumonia (LIP), and the results were compared with those for Ig V(H) genes from five HIV-negative LIP patients. The findings of this study are consistent with the different immunological situations of HIV-related and HIV-negative LIP. (a) The Ig V(H)3 subgroup was underexpressed in three of five cases of HIV-related LIP. In contrast, none of the HIV-negative cases showed this abnormality. Because the Ig V(H)3 subgroup encodes the largest portion of Ig V(H) genes, a depletion of B cells expressing Ig V(H)3 genes reflects a major alteration in the B-cell compartment. (b) All HIV-related LIP cases demonstrated two or three oligoclonal populations. HIV-negative cases showed minor monoclonal or polyclonal populations, but not oligoclonal ones. These oligoclonal populations suggest the coexistence of several occult clonal B-cell populations in HIV-related LIP. (c) Some oligoclonal clones in HIV-related LIP showed mutated framework regions not demonstrated in HIV-negative clones. This degree of variation exceeds the usual mutation rate for frameworks, suggesting a role for framework residues in antigen binding. (d) The frequency of D-D fusions of minor oligoclonal clones (HIV-related LIP) is higher than that of minor monoclonal clones (HIV-negative LIP). Such D-D fusions may enhance the probability of expression of antibodies capable of binding HIV glycoproteins.

Adult↗
PubMed2000

Controlling malignant pericardial effusion by intrapericardial carboplatin administration in patients with primary non-small-cell lung cancer.

Malignant pericarditis, when associated with massive pericardial effusion, presents a critical condition in lung cancer patients. Because this condition often arises in terminally ill patients, intensive therapy such as multi-drug combination chemotherapy is rarely appropriate. This study evaluated the clinical relevance of intrapericardial administration of carboplatin for controlling malignant pericardial effusions associated with non-small-cell lung carcinoma (NSCLC). The method used for 10 eligible patients consisted of draining the pericardial effusion and infusing 300 mg/body of carboplatin in 50 ml of saline through an in-place catheter into the pericardial space and clamping the catheter for 40 min. Nine of the 10 patients showed satisfactory results, and 8 experienced complete regression of the effusion. No major or minor adverse effects were observed. Pharmacokinetics analysis revealed that the concentration of free platinum in the pericardial fluid was very high while that of total platinum in the circulating plasma was very low, assuring the usefulness of the intrapericardial instillation of carboplatin in terminally ill patients for controlling malignant pericardial effusion when the systemic delivery of cytotoxic agents is inappropriate.

Adenocarcinoma↗
PubMed2000

Past administration of beta-lactam antibiotics and increase in the emergence of beta-lactamase-producing bacteria in patients with orofacial odontogenic infections.

OBJECTIVE: The purpose of this study was to determine the current status of beta-lactamase-producing bacteria in orofacial odontogenic infections. STUDY DESIGN: Microbiologic data regarding purulent exudate from 111 cases with orofacial odontogenic infections were analyzed in relation to the past administration of beta-lactams. RESULTS: beta-lactamase-producing bacteria were isolated more frequently from the beta-lactam-administered group (38.5%) than from the beta-lactam-nonadministered group (10.9%; P <.005), and they were isolated more frequently as the duration of administration increased. The predominant bacteria isolated included Prevotella (the most frequent isolate), viridans streptococci, Peptostreptococcus, and Fusobacterium, and 7.1% of total isolates produced beta-lactamase. Penicillin and cefazolin worked well with beta-lactamase-nonproducing Prevotella but were remarkably affected by beta-lactamase-producing Prevotella. Cefmetazole, sulbactam/cefoperazone, and imipenem worked well against both types of Prevotella. CONCLUSIONS: beta-lactams are still suitable for the first antimicrobial therapy in the treatment of these infections. However, because past beta-lactam administration increases the emergence of beta-lactamase-producing bacteria, beta-lactamase-stable antibiotics should be prescribed to patients with unresolved infections who have received beta-lactams.

Abscess↗
PubMed2000

Bacteriologic features and antimicrobial susceptibility in isolates from orofacial odontogenic infections.

OBJECTIVE: The aim of this study was to obtain information for an effective antimicrobial therapy against orofacial odontogenic infections; such information was obtained from recent bacteriologic features and antimicrobial susceptibility data. STUDY DESIGN: The bacteriology and antimicrobial susceptibility of major pathogens in 163 patients with orofacial odontogenic infections to 7 antibiotics was examined. RESULTS: Mixed infection of strict anaerobes with facultative anaerobes (especially viridans streptococci) was observed most often in dentoalveolar infections, periodontitis, and pericoronitis. Penicillin (penicillin G) was effective against almost all pathogens, although it did not work well against beta-lactamase-positive Prevotella. Cefmetazole was effective against all test pathogens. Erythromycin was ineffective against viridans streptococci and most Fusobacterium. Clindamycin exerted a strong antimicrobial activity on anaerobes. Minocycline was effective against almost all the test pathogens. The antimicrobial activity of levofloxacin against viridans streptococci was not strong. CONCLUSIONS: An antibiotic that carries out antimicrobial activity against both viridans streptococci and oral anaerobes should be suitable for treatment of dentoalveolar infection, periodontitis, and pericoronitis. Penicillin remains effective as an antimicrobial against most major pathogens in orofacial odontogenic infections. Cefmetazole, clindamycin, and minocycline may be effective against most pathogens, including penicillin-unsusceptible bacteria.

Anti-Bacterial Agents↗
PubMed2000

Induction by carbon-ion irradiation of the expression of vascular endothelial growth factor in lung carcinoma cells.

PURPOSE: To investigate the induction by carbon- ion irradiation of vascular endothelial growth factor (VEGF) mRNA and protein. MATERIALS AND METHODS: RERF-LC-AI lung squamous carcinoma cells were irradiated with carbon ions of either 13.3, 50 or 90keV/microm. Colony formation was used to determine cell survival. VEGF mRNA and protein of the irradiated cells were quantified by Northern blot analysis and ELISA assay, respectively. Genistein, Src tyrosine kinase inhibitor and H7, protein kinase C inhibitor, were used to inhibit VEGF mRNA expression. RESULTS: The relative biological effectiveness (RBE) of carbon ions (13.3, 50 and 90keV/microm) was 1.10, 1.97 and 2.30, respectively, in terms of D10 values. Single doses of 15 Gy with either X-rays or carbon ions significantly induced VEGF mRNA expression at 16-24h after irradiation with a maximum induction of 2.81-fold. A significant increase was also observed in VEGF protein levels, detected in culture supernatant 24h after irradiation with 50 and 90keV/microm carbon ions. Neither mRNA nor protein induction showed a dependence on LET. The induction of VEGF mRNA by carbon-ion irradiation was completely inhibited by pretreating cells with genistein and H7, indicating that Src tyrosine kinase and protein kinase C on cell surface membranes is involved in the induction. CONCLUSION: Irradiation of lung carcinoma cells with carbon ions induced VEGF mRNA expression and increased protein levels. The induction was dose-dependent. Radiation-induced DNA damage and/or its repair may not be a prerequisite for the induction of VEGF mRNA.

Carbon↗
PubMed2000

Central histamine contributed to temperature-induced polypnea in mice.

Breathing pattern is influenced by body temperature. However, the central mechanism for changing breathing patterns is unknown. Central histamine is involved in heat loss mechanisms in behavioral studies, but little is known about its effect on breathing patterns. We examined first the effect of body temperature on breathing patterns with increasing hypercapnia in conscious mice and then that of the depletion of central histamine by S(+)-alpha-fluoromethylhistidine hydrochloride (alpha-FMH) (100 mg/kg ip), a specific inhibitor of histidine decarboxylase, at normal and raised body temperatures. A raised body temperature increased respiratory frequency with reductions in both inspiratory and expiratory time and decreased tidal volume. On the other hand, alpha-FMH lowered respiratory frequency with a prolongation of expiratory time at the raised temperature; however, this was not observed at a normal temperature. These results indicate that central histamine contributes to an increase in respiratory frequency as a result of a reduction in expiratory time when body temperature is raised.

Algorithms↗
PubMed2000

Effects of hemoglobin on pulmonary arterial pressure and pulmonary vascular resistance in patients with chronic emphysema.

BACKGROUND: The increase in viscosity caused by secondary polycythemia is thought to be one of the major causes of pulmonary hypertension secondary to chronic emphysema. However, very few clinical studies considered the relation between pulmonary hypertension and polycythemia in the case of chronic obstructive pulmonary disease. OBJECTIVE: The purpose of this study is to elucidate the relative contribution of an increase in hemoglobin level (Hb) to mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR). METHODS: We retrospectively investigated 41 patients with chronic emphysema who had undergone a right heart catheterization. Multiple-regression analysis and F test were performed to investigate both direct effects of Hb and PaO(2) as independent variables on mPAP and PVR as dependent variables. RESULTS: Significant correlations were found between PaO(2) and mPAP (or PVR), or Hb and mPAP (or PVR), indicating that both Hb and PaO(2) are contributory to mPAP and PVR. The F test demonstrated that Hb and PaO(2) could directly affect the level of either mPAP or PVR. CONCLUSIONS: It was concluded that Hb had a direct effect on mPAP and PVR, independently of hypoxia in patients with chronic emphysema.

Aged↗
PubMed2000

Volume acceleration as an index of respiratory drive during exercise.

In order to evaluate the applicability of volume acceleration (A(I)) at the onset of inspiration as an index of neuromuscular output, CO(2) rebreathing in six healthy subjects and incremental-load exercise in eight healthy subjects was performed while measuring A(I) and mouth occlusion pressure (P(0.1)). During CO(2) rebreathing, A(I) increased linearly with end-tidal CO(2) partial pressure and P(0.1). During incremental-load exercise, P(0.1) and A(I) increased exponentially with minute ventilation and mean inspiratory flow, and A(I) increased linearly with P(0.1). Dyspnoea sensation at rest and exercise with or without the circuit system in eight healthy subjects was examined. Dyspnoea sensation increased markedly with the circuit system in some subjects. Incremental-load exercise was carried out by 13 healthy subjects and 21 patients with chronic obstructive pulmonary disease (COPD) to evaluate the difference in A(I) as respiratory drive between the two groups in the absence of a respiratory circuit. In patients with COPD, A(I) responses to minute ventilation, mean inspiratory flow and carbon dioxide output (VCO(2)) were greater than those in healthy subjects. In patients with COPD, the A(I) response to VCO(2) was greater in those with a lower FEV(1.0) (forced expiratory volume in 1.0 s), but the ventilatory response to VCO(2) was lower in those with a lower FEV(1. 0). These data suggest that A(I) reflects neuromuscular output during CO(2) rebreathing and incremental-load exercise under conditions where mechanical properties of the respiratory system are expected to be involved. During exercise, flow increased markedly, and the influence of the resistance of the respiratory circuit also increased. Therefore the use of A(I) has the advantage of less resistance (no respiratory circuit) and less additional respiratory effort, in comparison with the use of P(0.1), especially in patients with COPD.

Adult↗
PubMed2000

[The role of endothelin-B receptors in hypoxic pulmonary hypertension].

Endothelin-1 (ET-1) is a potent vasoactive peptide, and is thought to play an important role in the regulation of pulmonary vascular tone. Previous studies suggested that ET-1 can act as a vasoconstrictor via the endothelin-A and -B 2 receptors located on smooth muscle cells, and also act as a vasodilator through the endothelin-B 1 receptor situated on endothelial cells in the pulmonary circulation. To determine the role of endothelin-B receptors in hypoxic pulmonary hypertension, we examined the hemodynamic effects of a selective endothelin-B receptor agonist (IRL 1620) in chronic hypoxic pulmonary hypertensive rats. In rat lungs perfused with a half-blood solution, vasoconstriction by KCl administration was gradually reversed by IRL 1620 in normoxic rats, but not in chronic hypoxic rats. In in vivo studies, small doses of IRL 1620 induced transient vasodilation in normoxic rats, but had no obvious effects in chronic hypoxic rats. A high dose of IRL 1620 mediated vasoconstriction only in chronic hypoxic rats. Endothelin-B receptor messenger-RNA expression was lower in the lungs of chronic hypoxic rats than in normoxic rats. These results suggested that although the vasodilatory response mediated by endothelin-B receptor can be expected to play a protective role in the development of pulmonary hypertension, that response is diminished in hypoxic pulmonary hypertension.

Animals↗
PubMed2000

[Serum tumor markers for primary lung carcinoma].

A number of serum tumor markers are clinically relevant for primary lung carcinomas. None of them, however, is applied to screening of lung cancers because of their unsatisfactory sensitivity and specificity. Among them, measurements of CEA, CYFRA 21-1, NSE, and pro GRP frequently give subsidiary information as to differential diagnosis, monitoring of treatment, and early detection of recurrence. Current trend of the tumor markers for lung cancer includes development of new markers such as p53 tumor suppressor gene product and I-CTP for detecting bone metastasis. Attempts to detect micrometastases by means of RT-PCR of these marker genes are also discussed.

Antibodies, Neoplasm↗
PubMed2000

[Study of the two-step tuberculin tests and gamma-interferon assays in elderly persons].

Recently, an outbreak of lung tuberculosis among elderly residents happened in the home for aged, and it has become a social problem. To analyze the problem of tuberculosis in the elderly persons, we performed two-step tuberculin tests at two weeks interval and gamma-interferon assays for diagnosis of human tuberculosis to residents in the home for aged. 45 males (age; 77.3 +/- 8.9 SD) and 118 females (age; 81.9 +/- 8.6 SD) elderly persons (> or = 60) were examined. Standard dose of PPD was injected intracutaneously, and read at 48 hours. Erythema of 10 mm diameter or more was considered positive. The results were as follows. (1) The percentages of positive reactors in the 1st (T1) and the 2nd (T2) tuberculin tests were 50.3% and 68.1%, respectively. (2) The diameters of erythema and percentage of positive reactors (T1) did not very with age, but the size of erythema increased from 13.5 mm (T1) to 21.2 mm (T2) among those below 80 years, and from 13.0 mm (T1) to 16.4 mm (T2) among those 80 years or higher (p < 0.01). (3) The percentage of positive reactors (T1) varied by sex, namely males react stronger than females. (4) A dose of interferon-gamma released specifically in response to PPD stimulation of whole blood cultures showed no close relation with the diameters of erythema. In conclusion, tuberculin reactivity waned among elderly persons, and the fact suggests that they would have lower resistance against new infections, and as a result, they might have higher risk of developing tuberculosis. Elderly residents should be performed two-step tuberculin tests at the time of their entrance to the home for aged, and negative reactors should carefully be followed up.

Aged↗
PubMed2000

[A case of primary pulmonary artery myxosarcoma associated with severe pulmonary hypertension].

A 50-year-old man presented with progressive dyspnea on exertion, but with no history of chest pain or syncope. Chronic pulmonary thromboembolism was suspected and he was referred to our hospital. On ausculation, a grade 3 systolic murmur was heard, that was loudest in the fifth intercostal space lateral to the right sternal border. Chest radiography showed mild cardiomegaly and ventilation-perfusion scan revealed absence of perfusion in the left lung and the upper field of the right lung. Contrast-enhanced helical CT showed large mural defects in both main pulmonary arteries, clearly delineated by contrast medium. The left pulmonary artery was nearly completely occluded, and eccentric defects were observed projecting into the lumen of the pulmonary trunk. A tumor originating in the pulmonary artery was suspected, but a definitive diagnosis of the mass could not be made with pulmonary angiography and magnetic resonance imaging. The mean pulmonary arterial pressure was 50 mmHg. Further radiologic examinations failed to reveal the source of the embolus or tumor. It was decided to attempt surgical excision under total cardiopulmonary bypass. At operation, a gelatinous, lustrous, yellowish mass was found partially occluding the right main pulmonary artery and completely occluding the left. The tumor adhered tightly to the intima of the vessel and was inoperable. The patient could not be weaned from percutaneous cardiopulmonary support and died 3 days after surgery. Histologic examination of the excised specimen revealed myxosarcoma.

Chronic Disease↗
PubMed1999

Oxidative stress and haematological changes in immobilized rats.

Immobilization stress induces formation of reactive oxygen species (ROS) and leads to the oxidative injury in various tissues. In this study, the effects of immobilization stress on peripheral blood cells distribution, plasma level of thiobarbituric acid reactive substances (TBARS), and activities of antioxidant enzymes in erythrocytes were investigated in male Fischer rats. A significant increase in plasma TBARS was observed during and after the stress. Dramatic increases of neutrophils and monocytes imply that ROS formation resulted from their activation. Furthermore, the antioxidant activities of catalase and superoxide dismutase (SOD) in erythrocytes were dramatically increased during and after the stress, while a large fall in erythrocyte number was observed. These findings suggest that the activation of immune cells can be a source of the immobilization-induced ROS production, and that antioxidant enzymes in erythrocytes play an important role in preventing the ROS-induced injuries.

Animals↗
PubMed1999

Association between smoking and tumor progression in Japanese women with adenocarcinoma of the lung.

We studied the effect of smoking on tumor progression in 3312 patients with lung cancer registered at the National Matsudo Hospital and National Cancer Center Hospital East between 1977 and 1996. The odds ratios of the following variables for tumor extent (localized versus advanced disease) and hazard ratios for survival were calculated in both sexes separately using the logistic regression and Cox proportional hazard models, respectively: smoking history, number of cigarettes smoked per day, pack-years smoked, age, histological type, and the year of admission. Of the 943 women, 367 (38.9%) were smokers and 694 (73.6%) had adenocarcinoma, whereas of the 2369 men, 2255 (95.2%) were smokers and 1010 (42.6%) had adenocarcinoma. In female adenocarcinoma patients, the odds ratio (95% confidence interval) for advanced disease and the hazard ratio (95% confidence interval) for survival with an increase of 30 cigarettes smoked per day were 2.86 (1.49-5.49) and 1.52 (1.13-2.04), respectively, but in those with non-adenocarcinoma, the odds ratio and hazard ratio were 0.96 (0.41-2.23) and 1.13 (0.75-1.70), respectively. In male patients, smoking history influenced tumor progression regardless of histological type, but the odds ratios and hazard ratios were lower than those for women with adenocarcinoma. In conclusion, smoking habit was closely correlated with progression of adenocarcinoma in women. This association was not observed in women with non-adenocarcinoma and was weaker in men, suggesting various effects of smoking on lung cancer development depending on gender and the histological type of the tumor.

Adenocarcinoma↗
PubMed1999

Hemodynamic abnormalities in the left atrial appendage in patients with paroxysmal atrial fibrillation, with special reference to albumin-contrast echocardiographic aspects.

AIM: We assessed the prolonged dysfunction of the left atrial appendage caused by paroxysmal atrial fibrillation. METHODS AND RESULTS: Transesophageal echocardiography with intravenous albumin-microspheres (Albunex, 0.2 ml/kg) was performed in 100 consecutive patients (44 patients in sinus rhythm without previous paroxysmal atrial fibrillation: 13 patients in sinus rhythm who had had previous episodes of paroxysmal atrial fibrillation; and 43 patients with sustained atrial fibrillation). We compared the left atrial appendage ejection fraction and degree of opacification in the left atrial appendage with Albunex in the groups. Patients with previous paroxysmal atrial fibrillation had lower left atrial appendage ejection fractions than patients in sinus rhythm without paroxysmal atrial fibrillation (33 +/- 14 vs. 47 +/- 14%, p < 0.001). More than half of the patients (7/13 [54%]) with previous paroxysmal atrial fibrillation showed delayed and incomplete opacification of the left atrial appendage with Albunex. CONCLUSION: We conclude that paroxysmal atrial fibrillation causes left atrial appendage stunning, at least in some patients.

Aged↗
PubMed1999

Manifestation of pulmonary hypertension during REM sleep in obstructive sleep apnea syndrome.

The effect of sleep stage change on pulmonary circulation has not been well documented in patients with obstructive sleep apnea syndrome (OSAS). We investigated whether or not stage-specific change can affect pulmonary artery pressure (Ppa) in patients with OSAS. Thirty-one patients with OSAS underwent right cardiac catheterization in the daytime and the following night, including 19 patients in whom Ppa could be measured throughout non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Ten of the 19 patients had daytime pulmonary hypertension (PH) defined by a mean Ppa (Ppa) >/= 20 mm Hg. Then we analyzed Ppa response to hypoxia spontaneously occurring during the period of sleep apnea. The slopes of the regression lines between arterial oxygen saturation measured by pulse oximeter (SpO2) and Ppa curves were almost the same in both NREM and REM patient groups with or without daytime PH, whereas the response curve was significantly shifted upward in REM compared with NREM patients with daytime PH. Furthermore, Ppa was elevated more markedly in association with REM burst, phasic REM, compared with tonic REM. We conclude that vascular tone of pulmonary artery could be elevated in association with REM sleep which is independent of the degree of hypoxia, and that this state-specific change is manifested in patients with daytime PH.

Adult↗