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Biomedical subjects

M Nasu

Publications and source records attributed to M Nasu.

At least 253 records · Page 14Linked to original sources
PubMed1994

Non-invasive Doppler technique for detection of flow velocity in left internal mammary artery grafts.

The capability of Doppler to detect patency of left internal mammary artery grafts through the supraclavicular approach was evaluated. A total of 37 patients with a left internal mammary artery graft to the left anterior descending artery were divided into three groups, according to postoperative coronary angiographic studies. Group 1 comprised 20 patients with no significant stenosis of the left internal mammary artery and subtotal or total obstruction in the left anterior descending coronary artery proximal to the anastomotic site. There were ten patients with no significant stenosis of the left internal mammary artery and 75% stenosis of the left anterior descending coronary artery in group 2. Seven patients with significant stenosis of the left internal mammary artery formed group 3. Analysis of the flow velocity pattern in the left internal mammary artery graft included: (1) systolic peak velocity (SPV), (2) diastolic peak velocity (DPV), (3) systolic time velocity integral (SI), (4) diastolic time velocity integral (DI), (5) diastolic peak velocity/systolic peak velocity and (6) diastolic time velocity integral/diastolic time velocity integral+systolic time velocity integral. There were no significant differences in systolic peak velocity and systolic time velocity integral between the three groups. The diastolic peak velocity and diastolic time velocity integral were greater in group 1 than in groups 2 (P < 0.05, P < 0.01) and 3 (P < 0.05). The diastolic peak velocity/systolic peak velocity and diastolic time velocity integral/diastolic time velocity integral+systolic time velocity integral ratios in group 3 were significantly smaller than in groups 1 and 2 (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMed1994

[Significance of urinary fibrin/fibrinogen degradation product (FDP) D-dimer measured by highly sensitive ELISA method with a new monoclonal antibody (D-D E72) in various renal diseases].

In order to clarify the abnormalities of the coagulation and fibrinolysis system in patients with various renal diseases, we produced a new monoclonal antibody for FDP (fibrin/fibrinogen degradation product) D-dimer (D-D E72). We also established a new highly sensitive method of enzyme-linked immunosorbent assay (ELISA) for urinary FDP D-dimer using this monoclonal antibody. The urine from 110, patients with various renal diseases was investigated for the FDP D-dimer. The results are summarized as follows: 1) Urinary FDP D-dimer in normal subjects was 0.69 +/- 0.60 ng/ml. 2) The level of urinary FDP D-dimer in patients with primary nephrotic syndrome and in patients with chronic renal failure was significantly higher than that of normal subjects, whereas the urinary FDP D-dimer levels in patients with diabetes mellitus were higher than those of normal subjects. 3) In the CGN and NS groups there was a tendency for an increase in the level of urinary FDP D-dimer in more active forms of the disease. 4) A significant correlation between urinary FDP D-dimer and urinary protein in the CGN and NS groups was demonstrated. 5) In all of the renal diseases investigated in this study, the ratio of urinary FDP D-dimer to total FDP was less than 4%.

Adolescent↗
PubMed1994

[An operative case of aortic regurgitation due to quadricuspid valve].

A case of quadricuspid aortic valve is described. A 43-year-old man admitted because of chest oppression on exercise. He had a ejection systolic murmur and decrescendo diastolic murmur. Electrocardiogram revealed severe left ventricular hypertrophy. Echocardiogram showed dilated left ventricle and supernumerary cusp between the right and left coronary cusp. Aortogram revealed quadricuspid aortic valve with grade 4 aortic regurgitation. At operation, quadricuspid aortic valve in which supernumerary cusp between right and left coronary cusp was smaller was found. Four cusps were excised and replaced with 23 mm Medronic-Hall prosthesis. His postoperative course was uneventful. Quadricuspid aortic valve has been extremely rare. Twenty operative cases has been reported. The clinical feature was presented.

Adult↗
PubMed1994

[A case of pulmonary lymphangiomyomatosis diagnosed by biopsy of retroperitoneal tumor and treated with hormonal therapy].

A 34-year-old woman was admitted to our hospital because of exertional dyspnea and ascites. Chest roentgenogram showed hyperinflation of the lung and diffuse reticular shadows. Abdominal CT showed retroperitoneal tumors. Ascites was considered to be chylous. These findings strongly suggested the diagnosis of pulmonary lymphangiomyomatosis. Under lumbar anesthesia, laparotomy was performed, and the histological finding of the retroperitoneal tumor revealed angiomyoma. Bilateral oophorectomy was performed. Medroxyprogesterone at 15 mg/day was administered postoperatively. In advanced cases of this disease, open lung biopsy or even transbronchial lung biopsy is often avoided because of severe cardiopulmonary dysfunction. However, such cases associated with retroperitoneal tumor, laparotomy is quite useful not only in making the diagnosis but also in the treatment of this disease.

Adult↗
PubMed1993

Spatio-temporal representation of sound intensity in the guinea pig auditory cortex observed by optical recording.

The spatio-temporal representation of sound intensity in the guinea pig auditory cortex was studied by optical recording with the aid of a voltage-sensitive dye. Changes in light intensity due to neural activity induced by sounds at various pressure levels were recorded with a 12 x 12 array of photodiodes. The amplitudes of the responses were displayed as sequential two-dimensional images. The iso-intensity bands revealed by neural activity were orthogonal to the isofrequency bands of tonotopical organization in the anterior field and dorsocaudal field. The frequency-intensity representation through the orthogonal organization varied with time. This mechanism may be adapted to the auditory cortex to sequentially process the three parameters of sound: frequency, intensity, and time. Furthermore, a new field was found in the ventrocaudal region of the auditory cortex. This field showed tonotopicity, but high thresholds.

Acoustic Stimulation↗
PubMed1993

Propranolol has direct antithyroid activity: inhibition of iodide transport in cultured thyroid follicles.

The effect of propranolol on the process of thyroid hormone formation was studied in a physiological culture system. Porcine thyroid follicles were preincubated with propranolol for 24 h. Iodide transport, iodine organification, and de novo thyroid hormone formation were measured by incubating these follicles with the mixture of carrier-free 0.1 microCi Na125I and 50 nM NaI for 2 to 6 h at 37 degrees C. A concentration of propranolol greater than 100 microM inhibited iodide transport in a dose-dependent manner; this inhibition was non-competitive with iodide and independent of thyrotropin (TSH). Reduced iodine organification and thyroid hormone formation was seen with 150 microM propranolol or greater. The inhibitory action of propranolol was not caused by beta-blocking activity, since D-propranolol (devoid of beta-blocking activity) inhibited iodide transport, and other beta-blockers (metoprolol, atenolol, and labetalol) did not inhibit iodide transport. The inhibition of iodide transport was most likely caused by membrane stabilizing activity since quinidine, which possesses the same membrane stabilizing activity as propranolol, also inhibited iodide transport. TSH-mediated cAMP generation and Na+K+ ATPase activity, membrane functions for iodide transport, were unaffected by propranolol. Our study has shown, for the first time, that propranolol has a direct antithyroid action, namely inhibition of iodide transport in the intact thyroid follicle.

Adrenergic beta-Antagonists↗
PubMed1993

A comparative study of effects of isoproterenol and dihydroouabain on calcium transients and contraction in cultured rat ventricular cells.

We investigated the effects of isoproterenol, a beta-adrenergic agonist, and dihydroouabain, a Na+,K(+)-pump inhibitor, on Ca2+ transients and contraction of cultured rat ventricular cells and compared the effects with those of altered external ion concentrations, with special reference to the changes in diastolic intracellular free calcium concentration ([Ca2+]i). We measured [Ca2+]i of cultured cell aggregates, stimulated at 1.0 Hz, with the use of dual-wavelength microfluorometry of fura-2, at room temperature (24-26 degrees C). The contraction was measured as a shortening of the aggregates using a photodiode array placed on a video monitor. Isoproterenol increased the magnitude of contraction and the peak amplitude of the Ca2+ transient, in a concentration (10(-9)-10(-6) M)-dependent manner, but did not change the diastolic Ca2+ level. Isoproterenol at 10(-7) M or higher significantly shortened the duration of contraction and half decay time of a Ca2+ transient yet it did not change the time to peak. Dihydroouabain (10(-7)-10(-5) M) increased the contraction and elevated both systolic and diastolic calcium levels but it did not alter the duration of contraction, the time to peak and the half decay time. The effects of dihydroouabain on Ca2+ transients were mimicked by lowering [K+]o (0.4 mM), by lowering [Na+]o (74 mM) or by elevating [Ca2+]o (3.6 or 5.4 mM). Ryanodine (10(-5) M), by itself, decreased systolic Ca2+ transient amplitude, increased diastolic Ca2+ levels and prolonged the time to peak and the half decay time. In the presence of ryanodine, isoproterenol increased both systolic and diastolic [Ca2+]i. Thus, most procedures that increased the systolic Ca2+ transient amplitude increased the diastolic Ca2+ levels as well, and enhanced the contraction. The only exception was isoproterenol that markedly increased the systolic Ca2+ transient amplitude without affecting the diastolic Ca2+ level, a finding in keeping with the observation that isoproterenol stimulates Ca2+ uptake by the sarcoplasmic reticulum.

Animals↗
PubMed1993

[A case of cytomegalovirus pneumonia and Pneumocystis carinii pneumonia with lung cancer--diagnosis by the polymerase chain reaction].

A 64-year-old male was admitted to Oita Medical University Hospital because of primary lung cancer. After the anticancer chemotherapy, the patient developed a high fever. His chest X-ray showed diffuse reticular shadows bilaterally, which were considered to be a drug induced pneumonia, then pulse therapy with corticosteroid was performed. With this treatment, the diffuse reticular shadows disappeared. One month later, however, a severe interstitial pneumonia developed, and the patient died of respiratory failure. Autopsy findings demonstrated cytomegalovirus (CMV) and Pneumocystis carinni pneumonia. The polymerase chain reaction (PCR) for CMV in mononuclear cells in the blood was positive through out his hospitalization. In the sera, however, it was negative at the time of admission, then became positive 10 days before the onset of pneumonia. In addition, the PCR for P. carinni on the swab became positive as well. These results imply that PCR can be used for diagnosis of CMV and P. carinii infections from sera or swabs.

Cytomegalovirus Infections↗
PubMed1993

[An adult patient with EDTA-dependent pseudothrombocytopenia due to rubella virus infection].

We experienced an adult patient with EDTA-dependent pseudothrombocytopenia due to rubella virus infection. A 23-year-old male complaining of eruption and fever was admitted to our hospital on June 21, 1992. Laboratory findings on admission showed the platelet count 1.5 x 10(4)/microliters with EDTA, but 11.5 x 10(4)/microliters with heparin. Platelet agglutination was absorbed in the peripheral blood smear samples with EDTA. The hemagglutination inhibition titer for rubella virus raised from 1:32 to 1:52 in paired sera. We diagnosed this patient as having EDTA-dependent pseudothrombocytopenia and mild true thrombocytopenia due to rubella virus infection.

Adult↗
PubMed1993

[Disseminated Trichosporon beigelii infection: report of nine cases and review].

Trichosporon beigelii (formerly called Trichosporon cutaneum) is an emerging pathogen of disseminated trichosporonosis in immunocompromised patients. We conducted postmortem microbiological examinations of lung aspirates and blood in the heart. T. beigelii was isolated from the samples of 7 (2.24%) of 313 patients. Five of 7 patients isolated were diagnosed as having trichosporonosis based on histochemical and clinical findings. The other two were considered as colonization. Immunohistochemical study using Cryptococcus neoformans-absorbed antiserum to T. beigelii was carried out on the sections of autopsied tissues with deep mycoses. The sections from seven patients were positively stained, which were formerly diagnosed as candidiasis and/or aspergillosis. Consequently, 9 patients had disseminated trichosporonosis caused by T. beigelii. In Japan, 43 patients including the present 9, 31 males and 12 females, aged 51 (range, 2-84), were reported in the literature. Thirty-seven (86%) patients had hematologic malignancy, and the majority of them revealed profound neutropenia due to cytotoxic chemotherapy. Thirty-eight (88%) patients died despite the anti-fungal chemotherapy including amphotericin B. New strategies for refractory disseminated trichosporonosis in immunocompromised patients is needed.

Adolescent↗
PubMed1993

Experimental gastritis induced by Helicobacter pylori in Japanese monkeys.

We used Japanese monkeys (Macaca fuscata) to establish an experimental model in order to clarify the pathogenicity of Helicobacter pylori in gastric and duodenal disorders. A suspension (5 ml; 10(9) CFU/ml) of H. pylori cells isolated from humans was sprayed around the antrum of the stomach of each of 12 of 17 animals with an endoscope. The remaining five animals were not inoculated; they served as a control group. On days 7, 14, and 28 after inoculation, the gastric mucosa samples were examined grossly and were biopsied for microscopic examination with an endoscope. H. pylori was recovered from 7 of the 12 inoculated animals (58%), and infiltration by neutrophils and monocytes was observed histologically. Macroscopic gastritis with erythema and erosions were noted for five of these animals. On day 28 after inoculation, five animals in the infected group were treated with ampicillin. In two infected but untreated animals, the bacteria persisted for more than 6 months. The result of the gastritis scoring of the antral mucosa and the ammonia concentration in the gastric secretion were significantly higher (P < 0.01 to 0.001) for the infected group than for the control group; however, these values decreased to levels comparable to those for the control group after treatment with ampicillin. Urease activity was positive in gastric biopsy specimens from five of the seven animals in the infected group after 7 days and from four of these animals after 14 days but was negative in all specimens from animals in the control group. The level of antibody (immunoglobulin G) in serum for the infected group was elevated but changed very little for the control group. These results suggest that this M. fuscata model can be used to study H. pylori infection and that H. pylori can induce gastritis.

Animals↗
PubMed1993

Correlation of serum antibody titers against hepatitis C virus core protein with clinical features by western blot (immunoblot) analysis using a recombinant vaccinia virus expression system.

In order to study the relationships among the clinical features of hepatitis C patients, the presence of hepatitis C virus (HCV) RNA in their blood, and their serum antibody titers against the core protein of virus and to study the antibody levels in asymptomatic HCV carriers, a recombinant vaccinia virus containing a core protein gene was constructed. The recombinant virus expressed a protein with a molecular mass of 22 kDa in RK-13 cells as determined by Western blot (immunoblot) analysis. By using the cell lysate of virus-infected cells and serially diluted serum samples, core antibody titers in the groups of patients in the chronic hepatitis phase and in the convalescent phase as well as in asymptomatic carriers were determined by enhanced chemiluminescence Western blot analysis. Almost all patients in the chronic phase were shown to have high antibody titers of more than 1:500,000 and with no exception had of HCV RNA in their sera. On the other hand, patients who had recovered naturally and were in the convalescent phase were shown to have significantly lower antibody titers, and the antibody was not detected in the lowest serum dilution of 1:500 in 43% of these patients (three of seven total patients). Antibody levels of patients who showed a good response to interferon treatment decreased to intermediate levels between those of patients in the chronic phase and those of patients in convalescent phase. The antibody titers in asymptomatic carriers varied considerably from 1:500,000 to 1:500, and 41% (11 of 27 total individuals) of these carriers showed a high titer equivalent to that of those in the chronic phase. Core antibody was detected consistently in the individuals in whom HCV RNA was detected. This system for core antibody might be useful for identifying the stage of an apparent HCV infection.

Base Sequence↗
PubMed1993

Ethanol has thyrotropin-like activity in cultured porcine thyroid follicles.

We describe TSH-like activity of ethanol for thyroid hormone formation in the physiological culture system. Porcine thyroid follicles were preincubated with 0-100 mM (0-0.58%) ethanol in the presence of 0-1280 microU/ml bovine TSH for 24 h; these follicles were then incubated with the mixture of Na125I and NaI to measure iodide uptake, iodine organification, and de novo thyroid hormone formation. Ethanol stimulated iodide uptake in a dose-response manner in TSH-free medium. Ethanol augmented the effect of TSH on iodide uptake, iodide organification, and thyroid hormone formation in the presence of 20-80 microU/ml TSH. When TSH concentration was 320 microU/ml or greater, ethanol no longer stimulated iodide uptake and thyroid hormone formation. Ethanol mediated iodide uptake and iodine organification were inhibited by potassium perchlorate and propylthiouracil respectively. The effect of ethanol on the thyroid follicle was reversible 24 h after removal of ethanol from the medium. The mechanism of TSH-like activity of ethanol was studied by measuring cAMP generation and Na+K+ATPase activity, a sodium pump necessary for iodide transport, in the presence of 0-1280 microU/ml TSH. Ethanol increased cAMP production in TSH-free medium; the increment of cAMP by ethanol was more prominent when 20-80 microU/ml TSH were present. Ethanol also augmented (Bu)2cAMP-mediated iodide uptake and TSH-mediated thyroid Na+K+ATPase activity. Thus, TSH-like activity of ethanol for thyroid hormone formation can be explained by activation of the cAMP system and Na+K+ATPase activity. Our results indicate that ethanol concentrations equivalent to the blood level of moderate to heavy alcohol drinkers exert TSH-like activity in the thyroid follicle.

Animals↗
PubMed1993

Influence of right ventricular ischemia on precordial ST depression during right coronary artery occlusion.

To determine the cause of precordial ST depression in acute inferior myocardial infarction, we evaluated the relationship between precordial ST deviation and ventricular involvement. Forty-nine patients who were admitted to the hospital with an acute inferior myocardial infarction, and 60 patients who were treated with elective angioplasty to the right coronary artery, were analyzed. All patients had single vessel disease and were divided into 2 groups (A and B) according to the site of the lesion. Patients in group A had a lesion proximal to the largest right ventricular branch, while in group B the lesion was distal to that branch. There were no differences in inferior ST elevation between the 2 groups, but precordial ST segments were more depressed in group B than in group A. A significant correlation was observed between inferior and precordial ST deviation in group B, but not in group A. These results were similar in patients with myocardial infarction and in those treated by angioplasty. These results suggest that precordial ST depression in an evolving inferior infarction is due to reciprocal ST deviation which reflects inferoposterior involvement. In addition, when inferior infarction is accompanied by right ventricular involvement the precordial ST depression is lessened.

Aged↗
PubMed1993

[Adult respiratory distress syndrome due to sepsis caused by Staphylococcus aureus: a case report].

A 59-year-old man, under treatment for osteoarthritis of the right hip joint, was admitted to the Department of Orthopedic Surgery of Health Insurance Nankai Hospital with complaints of high fever and severe right hip joint pain. Since he developed shock, he was transferred to the Department of Internal Medicine. The laboratory data showed marked increase of acute phase reactants, and Staphylococcus aureus was cultured from the abscess in the right hip joint. The chest X-ray film the next day showed diffuse pulmonary edema of both lungs. The diagnosis of adult respiratory distress syndrome (ARDS) due to sepsis caused by S. aureus was made. Septic ARDS due to S. aureus is rare. The patient was cured by mechanical ventilation and administration of antibiotics, methyl-prednisolone and Urinastatin, along with drainage of the abscess in the right hip joint.

Anti-Bacterial Agents↗