Biomedical subjects

Y Masuda

Publications and source records attributed to Y Masuda.

At least 505 records · Page 28Linked to original sources

PubMed1993

Expanded primary T nodules in the palatine tonsils from patients with IgA nephropathy.

We designed a study to investigate the morphological expression of immune responses in the palatine tonsils from patients with IgA nephropathy. To distinguish between the histological characteristics of the tonsils in habitual tonsillitis (47 patients) and IgA nephropathy (11 patients), we studied the T nodules, B-lymphoid follicles, germinal centers, areas of mixed T and B lymphocytes, lacunar epithelium and connective tissues; then we compared patients with habitual tonsillitis and IgA nephropathy. The T nodules in patients with IgA nephropathy were enlarged, and this change was not accompanied by atrophy of B-lymphoid follicles. Morphologically, primary T nodules were predominant. In reactive lymph nodes, T nodules generally play an important role in the extra-follicular maturation of stimulated B lymphocytes into Ig-secreting plasma cells. Therefore the enlarged primary T nodules remind us that this maturation may occur more frequently in the tonsils of patients with IgA nephropathy than in those with habitual tonsillitis. This suggests that some immunoregulatory dysfunction exists in the secretory immune system of mucosa-associated lymphoid tissues in patients with IgA nephropathy.

Adult↗

PubMed1993

Clinicopathological study of the effectiveness of tonsillectomy in IgA nephropathy accompanied by chronic tonsillitis.

Tonsillectomy is often effective in reducing proteinuria in patients with IgA nephropathy (IgAN), which might otherwise lead to renal failure. Twenty-eight patients with IgAN accompanied by chronic tonsillitis were observed for more than 2 years after tonsillectomy and studied clinicopathologically. Tonsillectomy was effective in 17 patients (effective group), but not effective in 11 (noneffective group). Many patients in the effective group showed mild proteinuria, whereas proteinuria of 1 g/24 h or higher was found in a few cases. In comparison with the noneffective group, the levels of serum IgA, polymeric IgA and circulating immune complex (CIC) in the effective group were significantly higher prior to tonsillectomy. Histopathologically, there was only a slight increase in mesangial cells and matrixes in the effective group compared with the noneffective group, and global glomerular sclerosis, small glomerular crescents and interstitial scarring were seldom found. Rupture of the glomerular basement membrane (GBM) occurred more frequently in the noneffective than in the effective group. In a study of IgA subclasses in the mesangial area of the glomerulus, IgA1 was predominantly stained in the effective group.

Chronic Disease↗

PubMed1993

Vegetative growth of higher plants on a three-dimensional clinostat.

Seedlings of rice, maize, cress, pea, and azuki bean were grown on a three-dimensional clinostat and changes in their vegetative growth processes were analyzed. A balanced relationship among the length or the weight of each organ was observed in these species even on the clinostat. Growth of pea second internodes is supported by the transport of sugars from the cotyledons, which was not influenced by the clinostat rotation. Thus, growth correlation and the translocation of sugars normally occurred even under simulated microgravity conditions. In contrast, morphogenesis was clearly changed by the clinostat rotation. The axiality along the gravity vector disappeared and so seedlings formed themselves into a sphere-like shape on the clinostat. The dorsiventrality was indistinct in growth of maize coleoptiles on the surface of the earth, but the clinostat rotation induced a clear dorsinventral bending. These changes in morphogenesis may influence the long-term growth phenomena and modify the life cycle of higher plants under a microgravity environment.

Biological Transport↗

PubMed1993

[Evaluation of blood flow in aortic aneurysm and dissection by cine magnetic resonance imaging].

The blood flow in aortic aneurysms and dissections was evaluated using cine MR imaging which depicts turbulent blood flow as a signal loss within a high-intensity blood pool or flowing blood. Six patients with 8 aortic aneurysms ranging 38 to 70 mm in diameter, and 16 patients with aortic dissections were imaged with a 0.5 or 1.5 T superconducting magnet using an ECG-gated fast field echo technique. Circulating flows were observed in 3 of 8 aortic aneurysms. This suggests that turbulent blood flow did not occur prominently in the relatively small aortic aneurysms imaged in this study. The false lumens were thrombosed in 2 of 16 aortic dissections. In 13 of the remaining 14 dissections jet flows were observed through the entry into the false lumen. In 2 of these cases the jet flows moved to and fro through the entry. The entry was not detected in a small abdominal aortic dissection. Re-entry was seen in one case. Using a spin-echo imaging technique, the entry can be diagnosed by detecting the interruption of the intimal flap and the flow void within the false lumen. However, the entry was more clearly depicted and the direction of blood flow better determined by cine MR imaging compared with the conventional spin-echo imaging technique. Cine MR imaging provides useful information about the blood flow in aortic aneurysms and dissections noninvasively.

Aged↗

PubMed1993

Determining the optimal time for endotracheal intubation during onset of neuromuscular blockade.

The disappearance of the response to single twitch stimulation (STS), double burst stimulation (DBS) and zero post-tetanic count (PTC) were evaluated to determine which best indicated the optimal time of endotracheal intubation during onset of neuromuscular blockade induced by vecuronium (0.08 mg kg-1) in 199 patients under thiopentone and halothane anaesthesia. Evaluations were performed by mechanomyographic and manual methods using a Myograph and a peripheral nerve stimulator. The study consisted of six parts. In part 1 (n = 30) and part 2 (n = 30), the response to STS (0.1 Hz) were evaluated mechanically and manually, respectively. In part 3 (n = 64), post-tetanic count (PTC) changes were evaluated mechanically. In part 4 (n = 30) and part 5 (n = 30), response to DBS were evaluated mechanically and manually, respectively. Intubation was performed immediately after obtaining zero PTC, or absence of response to STS (0.1 Hz) and DBS, and the intubation score was determined. In the control group of patients, intubation was performed under the same anaesthetic conditions as in parts 1-5 but without the administration of any muscle relaxant. The time from administration of any muscle relaxant. The time from administration of vecuronium until disappearance of response was 2.16 +/- 0.56, 2.49 +/- 0.68, 2.04 +/- 0.29, 2.20 +/- 0.53, and 2.97 +/- 0.61 min in parts 1-5, respectively. Excellent intubation conditions were not established in any of the control patients, and in 50.0, 70.0, 55.0, 70.0 and 90.0% of the patients in parts 1-5, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Effects of the new calcium antagonist monatepil on cardiac function and myocardial oxygen supply and demand in animals.

The effects of monatepil ([(+/-)-N-(6,11-dihydrodibenzo[b,e]thiepin-11-yl)-4-(p-fluor ophenyl)-1- piperazinebutyramide]maleate, AJ-2615, CAS 103377-41-9), a new calcium antagonist, on cardiac function and myocardial oxygen supply and demand were examined. 1. Monatepil reduced the spontaneous beats of isolated rabbit atria at the concentration of 3 x 10(-6) and 10(-5) mol/l. Monatepil decreased the contractile force of papillary muscles in a concentration-dependent manner (3 x 10(-8)-10(-5) mol/l). 2. Monatepil (0.3 mg/kg i.v.) slightly decreased heart rate in anesthetized open-chest dogs. This drug (0.1, 0.3 mg/kg i.v.) increased cardiac output and decreased blood pressure and total peripheral resistance. Monatepil decreased left ventricular dP/dtmax and slightly increased left ventricular end-diastolic pressure. 3. Monatepil (0.1-1.0 mg/kg i.v.) did not affect the PR interval, QRS duration and QTc interval of electrocardiograms in anesthetized dogs, whereas diltiazem (0.3 and 1.0 mg/kg i.v.) markedly prolonged the PR interval. 4. Monatepil (0.1-0.3 mg/kg i.v.) increased coronary blood flow (CoBF) and decreased myocardial oxygen consumption (MOC) and extraction. 5. Monatepil and diltiazem showed almost the same effects on cardiac function and myocardial oxygen supply and demand, but the negative chronotropic and negative dromotropic effects of monatepil were less potent than those of diltiazem.

Anesthesia↗

PubMed1993

[Influence of epidural and spinal block on VO2 and VCO2 measured by the indirect calorimetry].

We evaluated the influence of epidural and spinal anesthesia on VO2 and VCO2 measured by the indirect calorimetry. According to the spreading of anesthetic level, VO2, VCO2 and EE increased in the epidural group (EP group), but they decreased in spinal group (SP group). RQ was unchanged in both groups. Rate pressure product (RPP), in proportion to the MVO2 and the REE, did not correlate with the EE. The VO2, VCO2 and EE in EP group increased probably because; (1) epidural anesthesia does not affect the VO2 change, as it does not markedly suppress respiration; (2) cardiac stroke work is retained during epidural anesthesia, as it does markedly suppress circulation. In conclusion, epidural anesthesia exerts less influence on the respiratory and circulatory systems of patients compared with spinal anesthesia.

Adult↗

PubMed1993

[The signification of total elbow replacement in the treatment of rheumatoid arthritis].

The purpose of this paper is to emphasis the signification of total elbow replacement in the treatment of rheumatoid arthritis. Total elbow replacement were performed in twenty elbows in fourteen patients who had rheumatoid arthritis from 1982 to 1990. The follow-up period ranged from 2 to 9 years. Pain relief was complete in twelve patients. Preoperation flexion averaged 119 degrees, increasing to 127 degrees. Preoperation extension averaged -34 degrees, increasing to -24 degrees postoperation. There were no infection and fracture postoperatively. Radiolucent lines were seen in four humeral components, in one ulnar component. Proximal subsidence of the humeral component were found in two elbows. Posterior dislocation occurred in three elbows. In two cases, reduction was successful by three weeks immobilization in a plaster cast with the elbow in the flexion position. Transient ulnar nerve palsy was evident in two elbows. Revision surgeries were performed in two cases, which occurred dislocation and progressive subsidence. Multiple replacements of major joints were performed in ten patients. Two joints were replaced in two patients, three joints were replaced in six patients, four joints were replaced in two patients. Four total elbow replacements were performed accompanied with other joints replacement in the same anesthesia. We recommended two joint replacements in the same anesthesia in patient with good general condition. All patients had functional improvements after total elbow replacement, especially reaching of the arm. Four patients improved the walking by being able to use stich after total elbow replacement.

Activities of Daily Living↗

PubMed1993

[Pharmacokinetics of lidocaine used for total spinal anesthesia--a comparison between cervical and lumbar injection].

We studied the effects of site of injection on the serum concentration of lidocaine following total spinal block. Six mg.kg-1 of lidocaine was given into the cervical (n = 11) or lumbar (n = 7) subarachnoid space in 10 patients. The mean maximum serum concentration of lidocaine in the cervical group was found to be significantly greater than that in the lumbar group. Lidocaine given into the cervical subarachnoid space seems to be infiltrated easily into the intracranial space and consequently into the systemic circulation.

Adult↗

PubMed1993

Frequency of micronuclei induced in cultured lymphocytes by highly toxic organochlorine congeners.

Our human bodies have already been contaminated with various chemicals including highly toxic organochlorine compounds such as 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), 2, 3, 4, 7, 8-pentachlorodibenzofuran (PenCDF) and 3, 4, 5, 3', 4'-pentachlorobiphenyl (PenCB). In this study, in order to evaluate the genotoxicity of these three chemicals, we examined their effects on the induction of micronuclei, which has frequently been utilized as indicator of biological and genetic damage due to exposure to carcinogens or mutagens, in cultured human lymphocytes in the absence or presence of alpha-naphthoflavone (ANF) and the following results were obtained. 1)4 x 10(-5) M ANF alone significantly enhanced the frequency of micronuclei and the combination of ANF and either of TCDD, PenCDF or PenCB seemed to be additive as micronuclei inducers. 2) TCDD, PenCDF and PenCB significantly increased the frequency of micronuclei with almost the same dose-dependent manner in terms of the concentration of TCDD toxic equivalent. 3) TCDD, PenCDF and PenCB were considered to be very potent inducers of micronuclei, because their values of 50% effective concentration in micronuclei enhancement were around only 10 times higher concentration than that in healthy people, namely, 70ppt as TCDD. Consequently, the respective TCDD toxic equivalency factors of 0.5 and 0.2 for PenCDF and PenCB seemed to be reasonable so far as the induction of micronuclei was employed as an indicator of their genotoxic potency.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzoflavones↗

PubMed1993

Effects of 3-methylsulphonyl-4,5,3',4',-tetrachlorobiphenyl and 7,8-benzoflavone on aryl hydrocarbon hydroxylase activities of murine hepatic microsomes prepared from inbred strains with different Ah responsiveness.

In this work, we employed three Ah nonresponsive strains of mice, AKR, DBA and DDD, and three Ah responsive ones, C57, BALB and C3H, and prepared hepatic microsomes after the treatment of 3-methylcholanthrene (MC; 42 mg/kg, once) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 20 micrograms/kg, 6 times) in order to investigate the effect of 3-methylsulphonyl-4,5,3',4'-tetrachlorobiphenyl (3-MSF-4,5,3',4'-TCB; 1.5-45 micrograms/ml) and 7,8-benzoflavone (ANF; 1.4-42 micrograms/ml) on the hepatic microsomal AHH activities and the following results were obtained. 1. In the Ah nonresponsive strains of mice, 70 and 20% of the induced AHH activities with MC and TCDD, respectively, were attributable to the basal control enzyme activity and in the Ah responsive ones, only 4.2 and 1.4% of the induced activities with the two chemicals to the untreated control one, respectively. 2. 3-MSF-4,5,3',4'-TCB and ANF enhanced or reduced the enzyme activity depending on both their concentrations and kinds of microsomes employed, namely, control-, MC- and TCDD-microsomes. ANF showed higher potency for both the activation and inhibition of the AHH activity than 3-MSF-4,5,3',4'-TCB. 3. The effects of 3-MSF-4,5,3',4'-TCB and ANF on the enzyme activity of the MC treated Ah nonresponsive mice and those of the untreated control Ah responsive animals were quite similar and their effects on the AHH activity of the TCDD treated Ah nonresponsive strains were also almost the same as those of the MC or TCDD treated Ah responsive ones.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Effects of methylsulphonyl polychlorinated biphenyl homologues and 7,8-benzoflavone on aryl hydrocarbon hydroxylase activity.

First, we investigated the effects of eleven methylsulphonyl polychlorinated biphenyl (MSF-PCB) homologues at 1.5 micrograms/ml and 7,8-benzoflavone (ANF) at 1.4 micrograms/ml on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, 15 ng/ml)-induced aryl hydrocarbon hydroxylase (AHH) activity of cultured human lymphoblastoid cells and the following results were obtained. 1) The relative AHH activity (TCDD-induced AHH activity treated with each of the MSF-PCB compounds or ANF/the enzyme activity treated with acetone, %) of the ANF-treated culture was the smallest value (about 9%). 2) Among MSF-PCB homologues, 3-MSF-4,5,3',4'- and 4-MSF-3,5,3',4'-tetrachlorobiphenyls (TCBs) showed the highest inhibition and their relative enzyme activities were about 20%. 3) In the rest of MSF-PCB compounds, the relative AHH activities were as follows: 4-MSF-3,5,3',4',5'-pentachlorobiphenyl (PenCB); 37%, 3-MSF-4,5,2',3',4'-PenCB; 50%, 3-MSF-4,5,2',3'-TCB, 3-MSF-4,5,2',3',4',5'-hexachlorobiphenyl and 3-MSF-4,5,6,2',3',4',5'-heptachlorobiphenyl; 60 to 64%, 4-MSF-2,5,2',3',4'-PenCB; 77%, 3-MSF-2,5,3',4'-TCB; 88%, 4-MSF-2,5,2',5'-TCB; 93% and 3-MSF-4,5,3',4',5'-PenCB rather enhanced the TCDD-induced enzyme activity. Second, we prepared the hepatic microsomes of BALB/c (Ah responsive) and AKR/J (Ah nonresponsive) strains of mice after the treatment of olive oil (as control), 3-methylcholanthrene (MC, 42 mg/kg, once) and TCDD (20 micrograms/kg, 6 times, once every other week) in order to examine the effects of 3-MSF-4,5,3',4'-TCB (1.5 to 45 micrograms/ml) and ANF (1.4 to 42 micrograms/ml) on the respective hepatic microsomal AHH activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

[Change of PCDF concentrations in the blood of Yusho patients in recent ten years].

The blood of 16 Yusho patients sampled from 1982 (14 years after the incident) to 1992 were analyzed for congeners of polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) by high resolution gas chromatography-mass spectrometry and gas chromatography with electron capture detection, respectively. Biological half-lives of PCDFs and PCBs were estimated by following the change of blood concentrations of the Yusho patients in the equation of 1-compartment model. The biological half-lives of 2, 3, 4, 7, 8-penta-CDF and 1, 2, 3, 4, 7, 8-hexa-CDF in 8 individuals varied from 6.0 to 76 years with median 11.7 years and from 4.8 to 26.5 years with median 7.0 years, respectively. The half-lives of 1, 2, 3, 4, 6, 7, 8-hepta-CDF in 4 individuals varied from 2.1 to 15 years. Concentrations of PCBs in 13 individuals were estimated to be slowly decreased and increased with several years half-life in about half-and-half numbers.

Aged↗

PubMed1993

[PCB methylsulfone accumulated in muscle of mink dosed with PCB (Clophen A50)].

The structural requirements of the parent PCBs for the formation of the retained PCB methylsulfones (MeSO2-CBs) were investigated in mink (Mustela vison) exposed to PCB (Clophen A50). Muscle was analyzed for the MeSO2-CBs, which were determined by comparison of synthesized reference compounds. Major unmetabolized CBs such as 2, 4, 5, 2', 4'-pentaCB, 2, 4, 5, 2', 3', 4'-hexaCB, 2, 4, 5, 2', 4', 5'-hexaCB and 2, 3, 4, 5, 2', 4', 5'-heptaCB were determined in high concentrations in the mink muscle. All these PCBs are substituted in the 2, 4, 5-positions of at least one of the phenyl rings. On the other hand, CBs with free meta/para-positions were readily metabolized. Thus, at least 25 MeSO2-CBs were detected at concentration of 16 micrograms/g in extracted lipids from the muscle, corresponding to one tenth of PCB levels. Most of the methyl sulfone metabolites were 3- and 4-MeSO2-CB isomers of PCBs known to be rapidly metabolized, e.g. 2, 4, 2', 5'-tetraCB, 2, 3, 6, 4'-tetraCB, 2, 5, 3', 5'-pentaCB, 2, 4, 5, 2', 5'-pentaCB, 2, 3, 4, 2', 5'-pentaCB, 2, 3, 6, 3', 4'-pentaCB, 2, 3, 6, 2', 4', 5'-hexaCB and 2, 3, 6, 2', 3', 4'-hexaCB. 3-MeSO2-2, 5, 2', 5'-tetraCB and 3-MeSO2-2, 5, 6, 2', 5'-pentaCB were also found to be retained in the muscle, but their isomeric 4-MeSO2-CBs were not detected. Both the 3- and 4-MeSO2-2, 5, 6, 2', 4', 5'-hexaCB isomers were identified in the muscle extracts while no MeSO2-CB metabolite originating from 2, 3, 2', 4', 5'-pentaCB were detected in the muscle. These results show the PCBs with at least one phenyl ring with 2, 5-dichloro- and 2, 3, 6-trichloro-substitution are strongly favored and may be considered a criterion for the formation of MeSO2-CBs accumulated in mink muscle. These observations are in accordance with MeSO2-CBs detected also in other mammals.

Animals↗

PubMed1993

[Accumulation of hydroxylated PCB metabolites in blood].

In order to investigate some potential accumulate properties of hydroxylated PCB metabolites, blood and tissues such as livers, kidneys, lungs and adipose tissue from rats exposed to a commercial PCB (Aroclor 1254) were analyzed for hydroxylated PCBs (OH-PCBs). A large number of OH-PCBs were detected in the liver 1 day after exposure among which almost 13 have been identified in the blood. OH-PCBs were retained selectively in the blood probably due to binding between the OH-PCBs and a protein in serum. One major OH-PCB determined in rat blood was 4-OH-2', 3, 3', 4', 5-pentaCB formed from 2, 3, 3', 4, 4'-pentaCB after NIH shift. Blood of a grey seal from the Baltic also contained at least 8 OH-PCB congeners with 2 major compounds determined as 4-OH-2', 3, 3', 4', 5-pentaCB and 4-OH-2, 3, 3', 4', 5, 5'-hexaCB. Thus, 4-OH-2', 3, 3', 4', 5-pentaCB is the most retainable OH-PCB congener in blood from rats and seal. Human serum have also been found to contain a few number of OH-PCBs at concentration of 0.6 ng/g serum which corresponds to one fourth of PCB level.

Animals↗

PubMed1993

Persistence of human papillomavirus type 6e in adult multiple laryngeal papilloma and the counterpart false cord of an interferon-treated patient.

Human papillomavirus (HPV) type 6e DNA was detected in a laryngeal papilloma, in a papilloma recurring after an interval of six years and in the counterpart clinically-normal false cord of the same patient. No detectable subgroup change of HPV DNA occurred during the clinical course, which included therapy by CO2 laser followed by intramuscular alpha-interferon injection. The data demonstrated a single subtype of HPV to have persisted, and the prevention of a recurrence of laryngeal papilloma during our patient's long clinical course to have failed, in spite of the interferon treatment.

Adult↗

PubMed1993

[Evaluation of arterial sclerosis by CT, MR imaging and MR angiography].

Wall thickening and intimal changes obtained by enhanced CT are early findings of aortic sclerosis. These findings are often detected in the lower abdominal aorta and middle thoracic descending aorta of normal subjects over 30 years of age, as predictors of atherosclerosis. Arterial calcification is a useful sign for evaluating atherosclerosis, especially, in the coronary arteries. The sensitivity and specificity of CT-detected coronary calcification in coronary stenosis by CAG were 76% and 80%, respectively, in our study. In the patients with atherosclerosis, MRI demonstrates wall thickening, intimal projection and narrowing of the lumen in the aorta and large arteries. MRA can be applied to more peripheral arteries, particularly, in the head and extremities, and will be available for screening of atherosclerotic disease in the near future.

Adolescent↗

PubMed1993

Human papillomavirus DNA in squamous cell carcinomas of the respiratory and upper digestive tracts.

The prevalence of human papillomavirus (HPV) types 16 and 18 in clinical samples of squamous cell carcinomas from respiratory and upper digestive tracts was studied. HPV DNA of types 16 and/or 18 was detected using the polymerase chain reaction (PCR) method in 16 out of 121 cases (13.2%). By Southern blot hybridization, however, only the DNA from a laryngeal and a tonsillar carcinoma was found to hybridize with the whole HPV 16 DNA probe (two out of 16 HPV DNA-positive cases by PCR, 12.5%). None of the DNAs hybridized with the whole HPV 18 DNA probe. The discrepancy in the results of PCR and Southern blot hybridization methods seemed to reflect their sensitivity. The possible relation between prevalence of HPV DNA and carcinogenesis in respiratory and upper digestive tract is discussed.

Adult↗