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Biomedical subjects

N Miyazaki

Publications and source records attributed to N Miyazaki.

At least 19 recordsLinked to original sources
PubMed1992

Nonspecific granulomatous prostatitis.

Nonspecific granulomatous prostatitis is a relatively rare disorder of the prostate. We encountered 4 cases of this type of chronic inflammation, including 1 case of xanthogranulomatous prostatitis. In all cases the diagnosis was made by histologic examination of specimens obtained by transurethral resection, retropubic prostatectomy, or transrectal needle biopsy. Echography revealed a hypoechoic lesion in the case of xanthogranulomatous prostatitis, while the other cases showed no specific findings except for the associated adenomas. The major symptoms were frequency and dysuria caused by urinary tract infection or benign prostatic hyperplasia associated with the granulomatous prostatitis.

Aged↗
PubMed1992

A rapid anticancer drug screening assay by [14C] thymidine uptake in cultured human cancer cells.

A rapid screening test by suppression of DNA synthesis in cancer cells was developed with [methyl-14C]-thymidine (14C-TdR), a microculture filtration plate and a radiochromatoscanner. Mitomycin, tamoxifen and 5-fluorouracil (5-FU) were tested against four human gastric cancer cell lines and HeLa cells. The tetrazolium-based colorimetric (MTT) assay underestimated cell inactivation by mitomycin in three cell lines compared with the cell count and the 14C-TdR assays. Inactivation by 5-FU in one cell line by 14C-TdR uptake was considerably lower than that by other methods. Thus neither the radio-labelled DNA precursor uptake nor the MTT assay is suitable for every anticancer drug but they are complementary.

Antineoplastic Agents↗
PubMed1992

Diastolic mitral regurgitation in patients with first-degree atrioventricular block.

Diastolic mitral regurgitation has been observed in patients with DDD pacemakers when the atrioventricular (AV) delay was prolonged. However, diastolic mitral regurgitation associated with first-degree AV block has not been fully studied. We examined transmitral blood flow in 24 patients with first-degree AV block and normal cardiac function (ages 35.3 +/- 17.4 years), and in nine patients with DDD pacemakers and normal cardiac function (ages 73.1 +/- 8.1 years), using pulsed Doppler echocardiography. Diastolic mitral regurgitation was observed in 19 of 24 patients with first-degree AV block. Although PQ interval was shortened from 0.32 +/- 0.06 to 0.20 +/- 0.05 seconds (P < 0.01) after 1 mg atropine sulfate IV, the interval between P wave (ECG) and the beginning of diastolic mitral regurgitation did not change, while the duration of diastolic mitral regurgitation was shortened from 0.15 +/- 0.03 to 0.05 +/- 0.03 seconds (P < 0.01). There was a significant correlation between changes in PQ interval and changes in the duration of diastolic mitral regurgitation (r = 0.92, P < 0.001). Although cardiac output (3.9 +/- 0.05 L/min) and pulmonary capillary wedge pressure (5.1 +/- 1.5 mmHg) were normal in all patients with pacemakers, diastolic mitral regurgitation was observed when the AV delay was prolonged. The critical PQ interval for the appearance of diastolic mitral regurgitation was 0.23 +/- 0.01 seconds. In patients with prolonged PQ intervals, delayed ventricular contraction following atrial contraction may be associated with mitral regurgitation in the presence of a reversed AV pressure gradient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[A case of psittacosis with migratory infiltrates].

A 56-year-old man with fever, headache, cough and sputum was admitted to another clinic. Chest X-ray examination revealed infiltrates in the upper lobe of the right lung. Cefem and aminoglycoside therapy was not effective, and the infiltrates migrated from the right upper lobe to the right middle and lower lobes and then to the left lung. He was transferred to our clinic, and laboratory data showed that CRP was 6+; ESR, 119 mm/1 h; WBC, 3000/mm3; and CAR, 512. The tentative diagnosis of atypical pneumonia was based on the positive agglutination test for Legionella pneumophila, and treatment with erythromycin, minocycline and rifampicin resulted in alleviation of symptoms and resolution of the infiltrates in the lungs. Complement fixation titer for Chlamydia was 128 at admission and was elevated to 512 after 2 weeks. Indirect fluorescent antibody for Legionella was negative. Transient liver dysfunction was also observed.

Humans↗
PubMed1991

Determination of peptidylglycine alpha-amidating monooxygenase activity in human serum by thin-layer chromatography.

We developed a simple assay system for the quantitative evaluation of peptidylglycine alpha-amidating monooxygenase activity using as substrate a 125I-labeled synthetic tripeptide, 125I-D-Tyr-Val-Gly, thin-layer chromatography, and a radiochromatoscanner. The basic principle of this method is that thin-layer chromatography separates the reaction product, 125I-D-Tyr-Val-NH2, from the substrate in an assay mixture. The 125I activities of both substrate and product separated from each other on a thin-layer chromatography plate were quantified with a radiochromatoscanner and the rate of conversion of the substrate to the product was calculated from their counts. Human serum was used as an enzyme source and the values of alpha-amidation activity obtained by our method under optimal conditions were almost identical to those of the published method using ion-exchange chromatography (sulphopropyl-Sephadex C-50 column) and a gamma-counter. Our method makes it possible to estimate the 10-pmol level of the product using 10 microliters of human serum and to assay a large number of samples rapidly and easily. It is therefore thought to be very useful for screening various tissues for alpha-amidation activity.

Amino Acid Sequence↗
PubMed1991

Alzheimer amyloid beta/A4 peptide binding sites and a possible 'APP-secretase' activity associated with rat brain cortical membranes.

We carried out ligand binding experiments on membranes from rat brain cortical grey matter using radioiodinated beta/A4 8-17, with non-specific binding determined by the addition of 10 microM unlabelled peptide. Specific, reversible binding amounted to 60-75% of total binding and showed a clear dependence on time, temperature, pH and membrane concentration. Kinetic analyses indicated a high-affinity binding site with an apparent KD of 440 pM. However, the ligand was partly degraded with loss of the Ser8, Lys16 and Leu17 residues. Excision of the two C-terminal amino acids was inhibited by EDTA, EGTA, dithiothreitol or Zn2+ but was stimulated by Ca2+ or Mn2+. These studies demonstrate high-affinity binding sites for beta/A4 8-17 (or its derivatives) in rat brain, suggesting that this region may contain a physiologically important amino acid sequence and identify a potential membrane-associated amyloid precursor protein (APP) secretase activity.

Alzheimer Disease↗
PubMed1991

Possible roles of the peripheral vagal nerve in histamine-induced bronchoconstriction in guinea-pigs.

Although the importance of the vagal nerve in the pathogenesis of bronchial asthma has been reported, its precise contribution is still not fully understood. To shed more light on this area, we evaluated the possible contribution of vagal reflex in histamine-induced bronchoconstriction (HIB), and decided the site of action of histamine on the vagal nerve. For this purpose, we studied the effects of the bilateral cervical vagotomy, hexamethonium (2 mg.kg-1) or tetrodotoxin (0.5 mg.kg-1) on HIB (8 micrograms.kg-1, iv) in anaesthetized and mechanically-ventilated guinea-pigs. We also studied whether or not atropine (1 mg.kg-1) decreases HIB after vagotomy, including either the treatment of hexamethonium or tetrodotoxin. Airway responses were assessed by measurement of pulmonary resistance. The following results were obtained; 1) the response to histamine was significantly enhanced by the vagotomy, hexamethonium or tetrodotoxin; 2) propranolol increased HIB, and HIB was further enhanced by the vagotomy in the animals treated with propranolol; 3) atropine significantly suppressed HIB after the vagotomy, hexamethonium or tetrodotoxin. These results suggest that the postganglionic vagal nerve plays an excitatory role in HIB through the release of acetylcholine from the nerve terminals. It is also suggested that the vagal reflex mainly exhibits an inhibitory role in the HIB of guinea-pigs, presumably by the action of the nonadrenergic inhibitory nervous system.

Animals↗
PubMed1991

[A case of sarcoid granulomatous interstitial nephritis improved by steroid therapy].

We report a case of sarcoid granulomatous tubulointerstitial nephritis diagnosed by renal biopsy. A 60-year-old man presented with productive cough, and exertional dyspnea of 3 months duration. A chest X-ray film revealed diffuse reticulonodular infiltrates in both lung fields. A transbronchial lung biopsy specimen showed inflammation of the alveolar septum associated with non-caseating granulomas. The patient also had tubular proteinuria and glucosuria. Ga-scintigraphy demonstrated an abnormal accumulation of gallium in both lungs and kidneys. Renal function tests revealed tubular dysfunction. Tubulointerstitial nephropathy was suspected. A renal biopsy specimen exhibited tubulointerstitial nephritis associated with numerous non-caseating granulomas, similar to the findings of the lung biopsy specimen. No glomerular abnormalities were evident. Later, a scalene node biopsy confirmed the diagnosis of sarcoidosis. Prednisolone therapy yielded a favorable outcome for both the renal and pulmonary involvement. During the corticosteroid therapy, measurement of the urinary beta-2-microglobulin concentration proved a valuable monitoring tool for assessing the recovery of the tubular impairment.

Humans↗
PubMed1991

[Studies on the nontuberculous lung mycobacteriosis in Japan. (Report of the study in the year 1987 and 1988 of the Mycobacteriosis Research Group of the Japanese National Chest Hospitals)--pulmonary infection caused by Mycobacterium kansasii has begun to appear in all over Japan including north Japan Hokkaido].

UNLABELLED: In this study, the Mycobacteriosis Research Group of the Japanese National Chest Hospitals (MRG) presents the reports of study years 1987 and 1988. As reported previously**, pulmonary infection caused by Mycobacterium kansasii occurred principally in South-West Japan (prefectures South-West of Tokyo) and did not appear in North Japan. However, this disease appeared in 1987 and 1988 in Hokkaido (Sapporo Hospital). Accordingly, we may say the disease occurs all over Japan. This is a noteworthy finding newly recognized in the study years. The prevalence rate of nontuberculous lung mycobacteriosis was determined as 2.92 or 2.78 in 1987 and as 2.02 or 1.91 in 1988 per 100,000 population per year. The estimated rates based on the ratio of nontuberculous lung mycobacteriosis against active lung tuberculosis and based on the ratio of nontuberculous lung mycobacteriosis against culture-positive lung tuberculosis well agreed with each other. COMMENT: In this country, chest physicians customarily report their cases of nontuberculous mycobacteriosis including lung tuberculosis, because the payment of treatment for patients with tuberculosis is free. Because of this custom, tuberculosis statistics surely contain cases of nontuberculous mycobacteriosis. Caution about this has been paid in calculating the prevalence rate. From the study year 1987, the MRG chairman moved from Michio Tsukamura, The National Chubu Hospital, to Nobuhiko Kita, The National Kinki Chuo Hospital.

Humans↗
PubMed1991

[Clinical evaluation of sultamicillin in lower respiratory tract infections].

Clinical efficacy and safety of sultamicillin (SBTPC) in patients with lower respiratory tract infections, mainly pneumonia and bronchitis, have been evaluated in a multicenter trial by 19 institutions in the Kyushu area during a period of 12 months from December 1988 to November 1989. 1. Clinical evaluation was made in 132 patients and efficacy rates of SBTPC were 80.0% (28/35) for pneumonia, 78.5% (73/93) for bronchitis and 100% for the remaining 1 patient with other respiratory tract infections. The overall efficacy rate was 79.1% (102/129). 2. Clinical efficacy rate of SBTPC for respiratory tract infections in patients with underlying diseases such as chronic bronchitis, old pulmonary tuberculosis etc., was 75.0% (60/80) which was not significantly different from the efficacy rate of 85.7% (42/49) in patients without underlying diseases. 3. Of 13 patients who failed to respond to previous antibiotic treatments, 8 (61.5%) were effectively treated with SBTPC. 4. Clinical efficacy rates against infections caused by single species of organisms were 90.9% (10/11) for Haemophilus influenzae, 100% (8/8) for Streptococcus viridans and 100% (3/3) for Staphylococcus aureus. The overall clinical efficacy rate in all cases of monomicrobial infections was 88.6% (31/35), in polymicrobial infection 45.5% (5/11) and the overall efficacy rate in cases in which causative bacteria were identified was 78.3% (35/46). 5. Adverse reactions occurred in 6.8% (9/132) of the patients. The symptoms included allergic reaction in 1 patient, gastrointestinal system disorders in 7 patients and general fatigability in 1 patient. As abnormalities in laboratory test values, elevations of A1-P, GOT, and GPT were observed in 3 patients during the study, but returned to normal after discontinuation of SBTPC administration. 6. SBTPC is a useful antibiotic in the treatment of lower respiratory tract infections under the current medical environment where resistant organisms which produce beta-lactamases have been increasing.

Adolescent↗
PubMed1990

[An autopsy case of acute interstitial pneumonia].

An autopsy case of a 77-year-old male with acute interstitial pneumonia (AIP) is reported. The patient died of respiratory failure in the extremely rapid course of 8 days. The histogenesis of the thickening of the alveolar wall and the intraluminal lesions were noticed. Incorporation of the hyaline membrane as well as the intraseptal edema and septal cell proliferation played an important role in the fibrous thickening of the alveolar wall. The intraluminal granulation tissue was observed in the alveolar space and the alveolar duct, often extending into the respiratory bronchioles. Intraluminal granulation tissues in the alveoli frequently had the appearance of intraluminal buds of mesenchymal cells, so-called Masson's bodies, and there was little remodeling of pulmonary structures in this case. These findings suggest an acute, diffuse and severe damage of the peripheral respiratory tract and are consistent with bronchiolitis obliterans with classical interstitial pneumonia (BIP) by Liebow and AIP by Katzenstein. This patient had suffered from suspected "Bronchiolitis obliterans organizing pneumonia" (BOOP) one and half years ago. The relationship between AIP, BIP and BOOP is discussed.

Aged↗
PubMed1990

Effects of azelastine on vagal neuroeffector transmission in canine and human airway smooth muscle.

Azelastine is a newly developed antiallergic drug that is reported to antagonize histamine and leukotrienes in addition to its inhibitory action on release of chemical mediators. In the present study, the effects of azelastine on neuroeffector transmission in the airway smooth muscles with double sucrose gap and isometric tension-recording methods were evaluated. Azelastine (10(-8) to 10(-6) mol/L) markedly decreased the contractile response of human bronchial and dog tracheal muscle strips to electrical field stimulation (10 pulses at 20 V, 20 Hz, 800 microseconds) in a dose-dependent manner. In parallel with actions on twitch contractions, azelastine suppressed the amplitude of excitatory junction potentials of dog trachea without changing the resting membrane potential and input resistance of smooth muscle cells. However, azelastine did not alter acetylcholine sensitivity of the smooth muscle cells. These results indicate that azelastine possesses an inhibitory action on the release of acetylcholine by vagal nerve terminals. This inhibitory effect of azelastine may contribute to the treatment of asthma in addition to its antiallergic actions.

Acetylcholine↗
PubMed1990

Effect of endogenous tachykinins on neuro-effector transmission of vagal nerve in guinea-pig tracheal tissue.

To elucidate the effect of endogenous tachykinins on neuro-effector transmission of vagal nerves, we performed in vitro experiments using guinea-pig tracheal smooth muscle. The subthreshold dose (the highest dose which did not induce any smooth muscle contraction) of capsaicin (10(-8) to 10(-7) M) increased the amplitudes of contractions evoked by electrical field stimulation (EFS) significantly, but not those by acetylcholine (ACh). The inhibitor of neutral endopeptidase, phosphoramidon (10(-7) to 10(-6) M), increased the contractions evoked by EFS significantly. The inhibitor of cholinesterase, physostigmine (10(-6) to 10(-5) M), induced smooth muscle contractions, but such contractions were inhibited by atropine, suggesting the spontaneous release of ACh from the vagal nerve terminals. The subthreshold dose of substance P or capsaicin increased the contractions evoked by physostigmine. These results indicated that endogenous tachykinins increase the spontaneous ACh release as well as the ACh release in response to vagal stimulation from the nerve terminals. Furthermore, it is suggested that the excitatory effects of the tachykinins on the vagal neuro-effector transmission may be modulated by neutral endopeptidase in the guinea pig.

Acetylcholine↗
PubMed1990

[The marrow granulocyte reserve in lung cancer patients].

The marrow granulocyte reserve (MGR) of patients with lung cancer have been estimated by measuring the maximum neutrophil increment after administration of hydrocortisone. The MGR was found to have decreased in four of 19 untreated patients, but the reason for this decrement was not clear. Further, there were no differences in the MGR between the cell types or cancer stages. The MGR in patients 70 years old or older tended to be decreased. After chemotherapy or radiation therapy, the MGR depressed significantly. However, on administration of OK 432, the MGR significantly increased in two patients who had received radiation therapy and whose MGR had been deficient initially.

Adult↗
PubMed1990

[Contribution of the vagal nerve on histamine-induced bronchoconstriction in guinea-pigs].

Recently, it has been suggested that the peripheral vagal nerve might participate in the bronchoconstriction locally in addition to the concept of "vagal reflex". We investigated the contribution of the vagal nerve on the modulation of airway responses to histamine (8 micrograms/kg, iv) in anesthetized and mechanically ventilated guinea-pigs. Airway responses were assessed by measurement of pulmonary resistance (RL). To determine whether the vagal nerve mediates excitatory effects by "vagal reflex" in guinea-pigs, we investigated the effects of vagotomy or hexamethonium (2 mg/kg, iv). Increase in RL induced by histamine was significantly enhanced after the vagotomy or the treatment of hexamethonium. Histamine-induced bronchoconstriction was also enhanced by the vagotomy in the animals after the administration of propranolol (1 mg/kg, iv). To determine whether the peripheral vagal nerve may play any role in the vagotomized animals, we investigated the effect of atropine (1 mg/kg, iv). Atropine reduced histamine-induced bronchoconstriction significantly in the vagotomized guinea-pigs or in the animals treated with hexamethonium. We conclude that the vagal nerve mainly exerts on inhibitory role through the central nervous system, and that the peripheral vagal nerve distal to ganglion plays an excitatory effects by releasing acetylcholine from the terminals in histamine-induced bronchoconstriction in guinea-pigs.

Animals↗