Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 55 records · Page 3Linked to original sources

PubMed2000

What determines the heart rate response to exercise in patients with atrial fibrillation?

We evaluated the factors that determine the heart rate response to exercise in 60 patients with atrial fibrillation (25 men and 35 women, with a mean age of 61+/-10 years) who underwent symptom limited cardiopulmonary exercise testing with blood sampling of atrial natriuretic peptide (ANP), 2-dimensional echocardiography and cardiac catheterization. Atrial muscles resected during the Maze operation were examined histologically in 12 patients. The heart rate response to exercise depended on the severity of the atrial organic injury, which was expressed as left atrial diameter, ANP secretion during the maximal exercise testing and the histological findings of atrial tissue. Conversely, we believe that the severity of the atrial injury can be predicted from the heart rate response to exercise in patients with atrial fibrillation.

Aged↗

PubMed2000

Estrogen modulates osteoblast proliferation and function regulated by parathyroid hormone in osteoblastic SaOS-2 cells: role of insulin-like growth factor (IGF)-I and IGF-binding protein-5.

Although there is clinical evidence showing that combined therapy with parathyroid hormone (PTH) and estrogen is additively effective in increasing the bone mass of patients with osteoporosis, the mechanism of the interaction between these hormones remains unclear. The present study was performed to determine whether estrogen would affect osteoblast proliferation and function modulated by PTH in human osteoblastic SaOS-2 cells. Human PTH-(1-34) significantly inhibited [(3)H]thymidine (TdR) incorporation, which was attenuated by 24 h pretreatment with 10(-10) to 10(-7) M 17 beta-estradiol (17 beta-E(2)) in a concentration-dependent manner. PTH significantly stimulated alkaline phosphatase (ALP) activity, collagen synthesis and type-1 procollagen mRNA expression after pretreatment with 17 beta-E(2 )in these cells. Tamoxifen, an anti-estrogen, antagonized these 17 beta-E(2)-induced effects. Pretreatment with insulin-like growth factor-I (IGF-I) mimicked estrogen action, and coincubation of 3 microg/ml anti-IGF-I antibody antagonized the effects of 17 beta-E(2 )as well as those of IGF-I. In the presence of 17 beta-E(2 )pretreatment, PTH strongly stimulated IGF-binding protein (IGFBP)-5 mRNA expression in these cells, and recombinant IGFBP-5 increased type-1 procollagen mRNA expression and ALP activity. In conclusion, estrogen attenuates PTH-induced inhibition of osteoblast proliferation and PTH stimulates osteoblast function in the presence of estrogen pretreatment. IGF-I and/or IGFBP-5 seemed to be involved in the estrogen-induced modulation of PTH action on osteoblast proliferation and function.

Alkaline Phosphatase↗

PubMed2000

Pyogenic granuloma of the tongue early after allogeneic bone marrow transplantation for multiple myeloma.

Oral complications occur frequently after bone marrow transplantation (BMT). Some of them are caused by regimen-related toxicity of the preparative regimen, and others by infections. In addition, oral tissues are targets of graft-versus-host disease (GVHD). Oral granulomatous lesions are not a common complication after BMT, and are especially rare on the tongue. Such rare lesions reported in the literature, developed late after BMT with oral chronic GVHD. We present here a patient who developed pyogenic granuloma of the tongue early after allogeneic BMT done for multiple myeloma. Regimen-related mucositis, oral acute GVHD, the administration of cyclosporine A, and the preexisting macroglossia might be responsible for the formation of granuloma.

Bone Marrow Transplantation↗

PubMed2000

[Recent knowledge allowing diagnosis and treatment of deep-seated trichosporonosis].

Deep-seated trichosporonosis is a lethal opportunistic infection in immunocompromised patients. For the rapid diagnosis of this condition, we developed a novel nested-PCR assay that detects DNA specific for clinically important strains of Trichosporon in serum of patients with disseminated trichosporonosis. In this assay, two sets of oligonucleotide primers were derived from the sequence of 26 S ribosomal RNA genes of T. asahii. The specific fragment was amplified from T. asahii and T. mucoides but not from other microorganisms. In a retrospective study using serum samples of patients with disseminated trichosporonosis, the specific fragment was detected in 64% (7 of 11). To treat this infection, we studied the efficacy of rhG-CSF alone and in combination with antifungal agents against disseminated trichosporonosis in neutropenic mice. The results suggested that rhG-CSF might be a useful immunomodulator against Trichosporon infections and the therapeutic outcome might be better when used in combination with antifungal agents.

Adjuvants, Immunologic↗

PubMed2000

[Primary pulmonary cryptococcosis with endobronchial lesion].

A 19-year old man was admitted to our hospital with fever and productive cough. Chest X-ray films revealed multiple nodular shadows accompanied by a fusing tendency in the right middle field. A diagnosis of bacterial pneumonia was indicated, and the patient was treated with antibiotics. However, because this failed to resolve the nodular shadows, bronchofibroscopy was performed. Examination with a fiberoptic bronchoscope revealed an elevated lesion in the truncus intermedius. Histopathologic examination of a specimen obtained by transbronchial biopsy revealed cryptococcal organisms with the infiltration of monocytes. These findings yielded a diagnosis of pulmonary cryptococcosis with endobronchial lesion. After 6 months of treatment with fluconazole, the multiple nodular shadows disappeared. Comparison of bronchoscopic findings before and after fluconazole treatment clearly demonstrated the efficacy of the therapy.

Adult↗

PubMed2000

[Susceptibilities of bacteria isolated from patients with lower respiratory infectious diseases to antibiotics (1998)].

The bacteria isolated from the patients with lower respiratory tract infections were collected by institutions located throughout Japan, since 1981. Ikemoto et al. have been investigating susceptibilities of these isolates to various antibacterial agents and antibiotics, and analyzed some characteristics of the patients and isolates from them each year. Results obtained from these investigations are discussed. In these 18 institutions around the entire Japan, 532 strains of presumably etiological bacteria were isolated mainly from the sputa of 438 patients with lower respiratory tract infections during the period from October in 1998 to September in 1999. MICs of various antibacterial agents and antibiotics were determined against 85 strains of Staphylococcus aureus, 100 strains of Streptococcus pneumoniae, 96 strains of Haemophilus influenzae, 75 strains of Pseudomonas aeruginosa (non-mucoid strains), 6 strains of Pseudomonas aeruginosa (mucoid strains), 38 strains of Moraxella subgenus Branhamella catarrhalis, 26 strains of Klebsiella pneumoniae etc., and the susceptibilities of 517 strains were assessed except for those strains that died during transportation. S. aureus strains for which MICs of oxacillin (MPIPC) were higher than 4 micrograms/ml (methicillin-resistant S. aureus: MRSA) accounted for 60.0%. Vancomycin (VCM) and arbekacin (ABK) showed the most potent activities against MRSA. But one of MRSA showed resistance to ABK with the MIC of 64 micrograms/ml. The sensitive strains of MRSA to VCM have decreased. The frequency of penicillin (PC)-intermediate S. pneumoniae (PISP) + PC-resistant S. pneumoniae (PRSP) have increased in 46.0% for 1998 comparatively from 30.9% of 1997's. But PRSP decreased, and PISP increased into 39.0% of 1998 years from 19.8% of 1997's. Panipenem (PAPM), imipenem (IPM) and faropenem (FRPM) showed the most potent activities against S. pneumoniae with MIC80s of 0.125 microgram/ml or below. Against H. influenzae and M. (B.) catarrhalis, almost all the drugs showed good activities. The sensitive strains of them against ceftazidime (CAZ) decreased in 1997, but those have increased in 1998. Inversely, the susceptibility of them against cefotiam (CTM) had been higher in 1997, but those have been lower in 1998. Tobramycin (TOB) showed the most potent activity against P. aeruginosa (both mucoid and nonmucoid strains). All drugs except ampicillin (ABPC) were active against K. pneumoniae. A quite few of K. pneumoniae showed low susceptibilities. Also, we investigated year to year changes in the characteristics of patients, their respiratory infectious diseases, and the etiology. The examination of age distribution indicated that the proportion of patients with ages over 70 years was 48.6% of all the patients showing a slight increase in every year. About the proportion of diagnosed diseases as follows: Bacterial pneumonia was the most frequent with 40.2%. The ratio of it has increased slightly, and the increased rate was 10% in patients with ages over 70 years compared with the results in 1997. Chronic bronchitis have decreased slightly with 27.6% in 1998. Number of strains isolated from patients before administration of antibiotics were more than those after administration of them in chronic bronchitis, but these were almost same number in bacterial pneumonia. Administration of antibiotics has changed the results of the frequency of isolation of bacterial species. Bacterial isolations before administration of antibiotics were as follows: S. pneumoniae 26.7%, H. influenzae 23.8%, S. aureus 13.3% and M. (B.) catarrhalis 10.8%. The frequencies of S. aureus decreased after antibiotics administration over 15 days, but the frequencies of P. aeruginosa (both mucoid and non-mucoid) was not affected. The frequencies of P. aeruginosa was 45.5% after administration over 15 days. The frequencies of S. pneumoniae decreased upon administration of antibiotics, these were only 4.5% over 15 days. The frequencies of H. (

Anti-Bacterial Agents↗

PubMed2000

[A case of primary macroglobulinemia with acute pulmonary edema].

A 54-year-old man with acute respiratory failure underwent emergency admission to our hospital. Acute pulmonary edema combined with severe pneumonia was strongly suspected, and treatment with diuretics, antibiotics, and corticosteroids was effective. The diagnosis, primary macroglobulinemia, was made from the following findings: a high level of the lgM 1 type monoclonal protein, and an elevated serum viscosity with characteristic "linked sausage effects" seen in the retinal veins. Lymphoplasmacytoid cells, plasma cells, and small lymphocytes were seen in the bone marrow and lymphoplasmacytoid cells were also seen in the smear of the patient's peripheral blood. The types of malignant cells found in his bone marrow were also seen in both infiltrative lesions in the lung parenchyma and the pleural effusion. We concluded that this was a case of primary macroglobulinemia with acute pulmonary edema, which was caused partly by the hyperviscosity syndrome. The antitumor effect of the corticosteroid might have some effect on the recovery from acute respiratory failure and primary macroglobulinemia. He was transferred to the Department of Hematology to receive suitable chemotherapy.

Acute Disease↗

PubMed2000

[Leukocytopenia and thrombocytopenia preceded by human parvovirus B19 infection: report of three adult cases].

In Saiki City, Oita, Japan, erythema infectiosum in children has been prevalent from June, 1999 to the time of writing (January, 2000). We present three adult cases of parvovirus B19-associated leukocytopenia and thrombocytopenia that developed during this epidemic. Between June and November, 1999, a 32-year-old woman, a 38-year-old woman, and a 63-year-old man were referred to our hospital for treatment of leukocytopenia and thrombocytopenia. All complained of common cold-like symptoms. Their WBC counts (percentage of neutrophils) were 1,000/microliter (70%), 1,900/microliter (40%) and 1,680/microliter (40%), their hemoglobin levels 9.4 g/dl, 9.8 g/dl and 14.9 g/dl, and their platelet counts 10.8 x 10(4)/microliter, 6.9 x 10(4)/microliter and 4.5 x 10(4)/microliter, respectively. The diagnosis of parvovirus B19 infection was documented by the presence of B19-specific IgM antibodies or serum positivity for viral DNA. In two cases, the leukocytopenia and thrombocytopenia resolved gradually. In the other case, leukocytopenia, thrombocytopenia and B19 infection persisted for more than two months. These cases suggest that parvovirus B19 may be a common cause of leukocytopenia and thrombocytopenia even in adult patients without hematological disorders (erythropoietic stress), and that testing for parvovirus infection is justified in such patients, even if anemia is slight, especially when erythema infectiosum is prevalent.

Adult↗

PubMed2000

[A small cell lung cancer shadow resembling beads on chest radiographs].

We present a case of small cell lung cancer whose shadow resembles bead son chest radiographs. An 81-year-old woman who had been receiving treatment from her doctor for pulmonary emphysema and chronic respiratory failure consulted our department because a small nodular shadow had been detected radiographically in the right lower lung field. The bead-like shadows in the radiographs and tomograms extended from the periphery of the right lower lobe to the pulmonary hilum. This case of small cell lung cancer appeared in chest radiographs to have an unusual shape.

Aged↗

PubMed2000

[A case of pulmonary manifestation associated with myelodysplastic syndrome].

A 69-year-old woman with myelodysplastic syndrome (MDS) was admitted to our hospital because of recurrent fever and pulmonary infiltration shadows. On the seventh day of hospitalization, she had an attack of high fever and cough and laboratory tests revealed an elevated leukocyte count and elevated serum C-reactive protein. Chest radiographs showed infiltration shadows in the right middle and lower lung fields. Because a diagnosis of bacterial pneumonia was initially suggested, she was treated with antibiotics. However, the infiltration shadows on the chest radiograph had not improve, so bronchofiberscopy was performed. Analysis of fluid obtained by bronchoalveolar lavage (BAL) showed an increase in the total cell count, predominantly in lymphocytes and neutrophils. A transbronchial biopsy specimen showed infiltration of numerous neutrophils with necrosis under the bronchial epithelium, and edematous septa were infiltrated with numerous neutrophils and lymphocytes. BAL, blood, urine, bone marrow, and sputum cultures were all free of bacteria, mycobacteria and fungi. Interstitial infiltration by numbers of neutrophils associated with MDS was diagnosed and steroid treatment was performed.

Aged↗

PubMed2000

[Anti-influenza A viral drug--amantadine].

Amantadine, an inhibitor of M2 ion channel of influenza A virus, is an oral antiviral drug which specifically inhibits the uncoating and viral replication of the influenza A virus. Studies have shown that amantadine treatment within 48 hours of acute infection of influenza A reduces fever within 24 hours and shortens the course of illness. Amantadine has been found to have an efficacy of 50 to 90% prevention of illness. However amantadine-resistant viruses have been recovered approximately 30% patients treated with amantadine, as early as 2-3 days into treatment. Side effects of insomnia, decreased concentration and dizziness have been reported in 5 to 33% of amantadine recipients. Therefore amantadine should be only used for influenza A infected high risk persons.

Adult↗

PubMed1999

Significance of spontaneous normalization of negative T waves in infarct-related leads during healing of anterior wall acute myocardial infarction.

This study was conducted to elucidate the significance of spontaneous normalization of negative T waves in infarct-related leads during the chronic phase of anterior wall acute myocardial infarction. Results of this study indicate that patients with spontaneous normalization of negative T waves in infarct-related leads between 1 and 6 months after anterior wall acute myocardial infarction have smaller infarct size, decreased left ventricular dysfunction, and greater improvement in left ventricular wall motion in the infarct area, suggesting that T-wave normalization represents functional recovery of viable myocardium in the infarct area.

Biomarkers↗

PubMed1999

Layer-specific horizontal propagation of excitation in the auditory cortex.

Optical imaging was conducted in rat auditory cortex slice preparations to study how horizontal excitation propagates in the cerebral cortex. When a horizontal cut was made between supragranular and infragranular layers, electrical stimulation of layer II/III elicited horizontally propagating excitation in supragranular layers with the same propagating velocities as those seen before a cut was made. Electrical stimulation of layer VI or the border between the white matter and layer VI also elicited horizontally propagating excitation in infragranular layers with the same propagating velocities as those seen before a cut was made. These results suggest that the horizontal propagation of excitation in supragranular and infragranular layers can occur independently in the auditory cortex.

Animals↗

PubMed1999

Relation between negative U waves in precordial leads on the admission electrocardiogram and time course of left ventricular wall motion in anterior wall acute myocardial infarction.

This study indicates that patients with anterior wall acute myocardial infarction showing negative U waves in the precordial leads on the admission electrocardiogram have greater improvement in left ventricular wall motion in the infarct region between 1 and 6 months after acute myocardial infarction. This suggests that these patients have a larger amount of stunned myocardium in the infarct region.

Aged↗

PubMed1999

Relation of QT dispersion to infarct size and left ventricular wall motion in anterior wall acute myocardial infarction.

Previous studies have shown that QT dispersion increases during acute myocardial infarction (AMI). However, the relation of QT dispersion to infarct size and left ventricular (LV) function in AMI has not yet been fully clarified. Accordingly, this study was conducted to elucidate this relation at 1 month after anterior wall AMI. We examined 94 patients with first anterior wall AMI (< or = 6 hours) who underwent coronary arteriography at admission, 1 month, and 6 months after AMI, and left ventriculography at 1 and 6 months after AMI. Mean QT dispersion on the chronic phase (about 1 month after AMI) electrocardiogram was 79 +/- 33 ms. There were no significant correlations between QT dispersion and peak creatine phosphokinase levels, LV ejection fraction, and regional wall motion in the infarct region at 1 month after AMI (r = 0.06, p = 0.57; r = 0.11, p = 0.29; r = -0.05, p = 0.63, respectively). In conclusion, the findings of this study suggest that QT dispersion on the resting electrocardiogram at 1 month after anterior wall AMI is unrelated to infarct size estimated by the peak creatine phosphokinase level and the degree of LV dysfunction.

Aged↗

PubMed1999

Reactive oxygen species production of neutrophils in patients with acute promyelocytic leukemia during treatment with all-trans retinoic acid.

We measured N-formyl-methionyl-leucyl-phenylalanine-induced reactive oxygen species production by neutrophils from three patients with acute promyelocytic leukemia during treatment with all-trans retinoic acid using a luminol-enhanced chemiluminescence assay. The maximum level of reactive oxygen species production during all-trans retinoic acid treatment was 58.8 +/- 2.3 x 10(4) (mean +/- SEM) counted photons per seconds (cps), which was significantly higher (p<0.0001) than that of neutrophils from health volunteers (13.3 +/- 2.3 x 10(4) cps).

Antineoplastic Agents↗

PubMed1999

Spatiotemporal representation of binaural difference in time and intensity of sound in the guinea pig auditory cortex.

Neural activity of the auditory cortex (AC) in response to a change of interaural intensity difference (IID) and interaural time difference (ITD) of sound stimuli was observed by optical recording with a 12 x 12 photodiode array and the voltage-sensitive dye, RH795. Guinea pigs (280-450 g) were anesthetized with sodium pentobarbital (30 mg/kg) and supplemental doses of neuroleptic solutions. When both ears were stimulated dichotically by tone bursts (14 kHz, 75 dB SPL), excitatory optical signals appeared in both anterior (A) and dorsocaudal (DC) fields of AC. An increase of intensity of ipsilateral stimulation from 65 to 95 dB SPL caused a decrease of neural activity of isofrequency bands in both fields. An increase of ipsilateral leads from -2.5 to 10 ms resulted in a gradual decrease of the amplitude of the excitatory responses. A strong inhibition was observed in field DC and the ventral portion of field A. These results show the different spatiotemporal representation of IID and ITD sensitivities in AC. However, the ipsilateral lead inducing a large inhibition was much longer than the time difference (80 micros) calculated from the interaural distance of the guinea pig. This indicates that the longer binaural inhibition observed in AC would have a different functional significance from that of the neural system of ITD detection in the guinea pig.

Acoustic Stimulation↗

PubMed1999

Improved efficacy with nonsimultaneous administration of netilmicin and minocycline against methicillin-resistant Staphylococcus aureus in in vitro and in vivo models.

The effect of combined administration of netilmicin and minocycline against methicillin-resistant Staphylococcus aureus (MRSA) was investigated by using in vitro and in vivo models. Thirty one isolates of MRSA were tested for sensitivity to netilmicin, minocycline, and combination of both by the chequer board method. We used then a dynamic in vitro system, which simulates in vivo serum kinetics, to assess the effect of various combination regimens of these antibiotics against an MRSA isolate with a fractional inhibitory concentration index of 0.25. The following dose regimens were compared: netilmicin given alone; minocycline given alone; both antibiotics given simultaneously; netilmicin followed by minocycline at 2 h; or minocycline followed by netilmicin at 2 h. Netilmicin showed a stronger activity than minocycline. On the other hand, their combination was synergistic against 19% of isolates and additive against 77% of isolates. Against one isolate only, it was indifferent, and no antagonism was observed. In the auto-simulation system, the combination of antibiotics was generally more effective than single drugs, with the regimen netilmicin followed by minocycline at 2 h showing the highest antibacterial effect. In the mouse model of pulmonary infection, the bacterial counts and histopathological findings of the lungs improved by treatment with this regimen. This regimen led also to a significantly high survival rate of mice with systemic infection compared to the other treatment regimens. Therefore, it was concluded that administration of netilmicin followed by minocycline at 2 h may be an effective combination against MRSA infection.

Animals↗