Search PubMed⌕ Search

Biomedical subjects

N Yamaguchi

Publications and source records attributed to N Yamaguchi.

At least 523 records · Page 29Linked to original sources
PubMed1991

Work-related bladder cancer risks in male Japanese workers: estimation of attributable fraction and geographical correlation analysis.

One hundred and forty-nine relative risks (RRs) on occupations and bladder cancer were extracted from 27 case-control studies and geometric means were calculated for 27 occupations as summary RRs. Those in high risk occupations, among whom the summary RRs significantly exceeded unity, were found to be petroleum workers (RR = 3.51), dye workers (RR = 3.38), machinists (RR = 2.76), drivers (RR = 2.22), rubber workers (RR = 2.19), printers (RR = 2.12), clothing/tailors (RR = 2.10), wood workers/carpenters (RR = 1.70), miners (RR = 1.68), textile workers (RR = 1.63), mechanics (RR = 1.54), engineers (RR = 1.54), leather workers (RR = 1.49), painters (RR = 1.48) and chemical workers (RR = 1.44). The estimated numbers of male bladder cancers in 1980 in the high risk and other occupations were 820 and 2065 cases, respectively. The estimated number of work-related bladder cancer was 548 cases, the attributable fraction being 19% in active employees and 12% in the entire population. The geographical distribution of male bladder cancer deaths in Japan was positively correlated with the distributions of workers in the transport/communications industry and in tertiary industries including services, wholesale, retail, finance and insurance, whereas it was negatively correlated with the distribution of workers in the agricultural industry. These findings suggest that workers in certain industries may be at high risk of bladder cancer, but lifestyle modification associated with urbanization and industrialization could be an alternative explanation.

Analysis of Variance↗
PubMed1991

Functional characterization of SV40-transformed adherent synovial cells from rheumatoid arthritis.

A total of 14 transformed cell clones were obtained by micro-injecting origin-defective SV40 DNA into three types of cloned adherent synovial cells (ASC) (dendritic cells (DCs), macrophage-like cells (MCs), and fibroblast-like cells (FCs)) from two rheumatoid arthritis patients (five DC clones (SV40-DCs), five MC clones (SV40-MCs) and four FC clones (SV40-FCs)). All the transformed cell nuclei expressed SV40-specific T antigen. The cells which formed a colony had a few times shorter doubling time than the original cells. IL-1 alpha, IL-1 beta and prostaglandin E2 were detected in the culture supernatant from the unstimulated transformed cells like untransformed cells. The SV40-DCs showed the most potent accessory cell function in oxidative mitogenesis assay among the three types of SV40-ASCs. Granulocyte macrophage colony stimulatory factor (GM-CSF) was detected only in the culture supernatant from the SV40-MCs without stimulation. Extensive phenotypic analysis revealed relatively cell-specific markers. SV40-DCs were HLA-DP+ and glial fibrillary acidic protein positive. SV40-MCs stained positive for 5'-nucleotidase and nonspecific esterase. These transformed ASCs retained much of the original cellular physiology of rheumatoid arthritis (RA) ASCs and may be a useful tool for characterizing the role of ASCs in the pathogenesis of RA.

Adult↗
PubMed1991

Detection of DNA-bound immunoglobulins in patients with lupus nephritis, using monoclonal anti-DNA antibody.

In order to investigate the relationship between renal histopathology and the characteristics of circulating immune complexes (CICs) in patients with lupus nephritis (LN), we measured the sizes of CICs, DNA-bound immunoglobulins in patients with systemic lupus erythematosus (SLE) and different histopathological forms of nephritis. Sera were obtained from nine patients: four with diffuse proliferative LN (DPLN), four with membranous LN (MLN), and one with mesangial LN, who fulfilled the criteria of the American Rheumatism Association for SLE. The DNA-bound immunoglobulins were measured by ELISA, in which ELISA plates were coated with mouse monoclonal anti-DNA antibodies. The sizes of CICs were analysed by sucrose density gradient ultracentrifugation. Large (larger than 19S), intermediate (19-7S) and small (nearly 7S) sized DNA-bound immunoglobulins (high peaks of IgG and IgA, but low IgM peaks) were found in the patients with DPLN. By contrast, in patients with MLN, the sizes of ICs; DNA-bound IgG, IgA were in general slightly larger than 7S. In one patient with DPLN, at the onset, various sized DNA-bound IgG, IgA and IgM were found. After the methylprednisolone pulse therapy, CICs became smaller and gradually disappeared. We conclude that the characteristics of DNA-anti-DNA IgG, IgA complexes may determine the localization of ICs in the glomeruli and suggest that CICs play an important role in the pathogenesis of LN.

Antibodies, Antinuclear↗
PubMed1991

Effects of clomipramine on the concentrations of catecholamines, indoleamines and their metabolites in 11 rat brain regions.

The effects of clomipramine (CMP) treatment on the brain concentrations of catecholamines, indoleamines and their metabolites were evaluated in 11 rat brain regions. An acute CMP treatment (15 mg/kg) reduced only the 5-hydroxyindole-3-acetic acid (5HIAA) concentrations in all regions. A long-term CMP treatment (14 days, 10 mg/kg/day) decreased the concentrations of dopamine (DA), 5-hydroxytryptamine and 5HIAA in the mesencephalon, and increased the DA concentrations in the hippocampus. In comparison with the values for the long-term treated rats, an acute injection of CMP (15 mg/kg) after a long-term treatment increased the norepinephrine concentrations in the hypothalamus and amygdala, and the concentrations of DA, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the basal ganglia. On the other hand, it failed to decrease the 5HIAA concentrations in the basal ganglia, frontal cortex, hypothalamus, cerebellum, pons + medulla oblongata, and mesencephalon.

Animals↗
PubMed1991

Sex concordance in proband-relative pairs with schizophrenia.

Sex concordance rates were investigated in 278 schizophrenic probands, who had at least one first-degree relative with schizophrenia, in order to find out whether the illness affects the same sex more often than the opposite sex when two close relatives become ill. No such unusual concordance rates were found in proband-relative pairs with schizophrenia. When 118 of the 278 probands were examined who had at least one parent with schizophrenia, the morbidity risk for schizophrenia in siblings of the same sex as the schizophrenic probands was significantly higher than that found in siblings of the sex opposite that of schizophrenic probands.

Adolescent↗
PubMed1991

Comparison of kindling at short interstimulus intervals in acutely and chronically prepared rabbits.

For the purpose of contributing methodologically to experimental research on epilepsy, we investigated whether a difference exists in kindling development between acute and chronic preparations using identical species of animals, kindled brain tissues, stimulus intervals, and intensities. Seizure-threshold stimulations repeatedly applied at 5-min intervals to the unilateral visual cortex in rabbits completed the generalization of epileptiform discharge trains after the 11th-24th trials in the acute preparations concomitantly with an increase in the afterdischarge duration and the development of independent discharges, whereas they induced no kindling phenomena even with 50 trials in the chronic preparations. These results indicate that there is an extreme difference in kindling susceptibility between acute and chronic preparations, resulting, presumably, from multifactorial dissimilarities in these experimental conditions.

Animals↗
PubMed1991

Kindling-induced neuronal plasticity in the dorsal hippocampus CA1 in acutely prepared rabbits: unit activity analysis.

To elucidate kindling-induced neuronal plasticity single cell discharge analysis, responses consisting of action potentials orthodromically elicited in the dorsal hippocampus CA1 by a single electric shock to the neighboring region were serially observed before, during and after kindling i.e. the repetition of stimulus trains applied to the same hippocampal region in acutely prepared rabbits. Eventually, the orthodromic unit response with identical amplitudes, which were regarded as a single cell origin, gradually increased in the firing rate at the interictal stages during and after the kindling. Further, an inhibitory period following the unit responses, during which no spontaneous unit activity appeared, was remarkably prolonged during and after the kindling. Both the increase of the unit responses and the prolongation of the inhibitory period irreversibly lasted for hours once they occurred. Such unit activity analysis confirms kindling-induced excitatory and inhibitory synaptic plasticity.

Action Potentials↗
PubMed1991

Usefulness of the newly proposed International Classification of Epilepsies, Epileptic Syndromes, and Related Seizure Disorders (1989): a trial on adult patients in a neuropsychiatric clinic.

The utility of the "International Classification of Epilepsies, Epileptic Syndromes, and Related Seizure Disorders," proposed by ILAE in 1989, was investigated in a neuropsychiatric clinic with a patient population numbering 300. Two hundred and three patients (67.7%) had localization-related epilepsies (LRE), including one idiopathic case. Sixty-six patients (22%) had generalized epilepsies, 50 idiopathic, 2 Lennox-Gastaut syndrome, and 14 symptomatic. Thirty-one patients (10.3%) with generalized tonic-clonic seizures occurring only during sleep had the epilepsies undetermined whether they are focal or generalized. In the symptomatic LRE cases, 34 cases could not be classified, and 7 of the cases with frontal lobe epilepsies were difficult to subtype. Eleven of the symptomatic LRE cases had some independent seizures, multiple foci in surface EEGs and were intractable. These cases may be defined as "multifocal epilepsies."

Adult↗
PubMed1991

A case of epilepsy characterized by spike-wave stupor followed for long period.

A 34-year-old housewife with nonconvulsive status epilepticus was followed up for 20 years since the initial fit. She maintained some contact with reality during the stupor and recalled the episode to some extent, while the EEG showed continuous spike-wave complexes. During the clinical course, the main type of seizures was spike-wave stupor, of which the maximum frequency was several times a week in the hospital and the duration was many minutes to several hours, and also secondarily generalized convulsive seizures occurred approximately once a month. The lasting control of spike-wave stupor was not achieved in spite of the various medications for the long follow-up period. The ictal EEGs of spike-wave stupor always showed the frontal origin. The meaning of the term "nonconvulsive status epilepticus" in this case was briefly discussed.

Adult↗
PubMed1991

Reduction of tissue noradrenaline content in the isolated perfused rat heart during ischemia: importance of monoamine oxidation.

The effect of ischemia on myocardial noradrenaline concentration and endogenous noradrenaline output was studied in the isolated perfused rat heart. Following a 15-min stabilization period, regional ischemia was produced by coronary artery ligation. After 60 min of ischemia, noradrenaline concentrations were significantly reduced in the interventricular septum and left ventricle but not in the right ventricle. The reduction in tissue noradrenaline concentration was not prevented when the 60-min ischemia was replaced by a 10-min ischemia followed by a 50-min perfusion. No modification in noradrenaline output was observed during a 60-min ischemia. In contrast, reperfusion was accompanied by a washout of noradrenaline in the coronary effluent, corresponding to only 2% of the amount lost by the tissue. The effect of monoamine oxidase inhibition during the whole ischemic period was studied by perfusing the preparation with pargyline starting 10 min before the artery ligation. Although the administration of pargyline did not alter the noradrenaline output, it did prevent a reduction in myocardial noradrenaline concentration. It was concluded that monoamine oxidase may contribute to the elimination of the noradrenaline lost by the cardiac tissue during ischemia.

Animals↗
PubMed1991

Protective effects of ceruloplasmin against electrolysis-induced oxygen free radicals in rat heart.

The potentially injurious effects of oxygen-derived free radicals (OFR) on the myocardium can be prevented in part by pretreatment with OFR scavengers or antioxidants. Since ceruloplasmin (CP) has been shown to possess potent antioxidant activity and scavenge a variety of OFR in vitro, we have undertaken to study its protective effects against myocardial injury induced by OFR. CP was freshly purified by a fast method that minimized proteolytic enzyme degradation. Free radicals were generated by the electrolysis (10 mA DC current for 1 min) of a Krebs-Henseleit solution perfusing an isolated rat heart preparation under constant pressure conditions. CP (0.25 microM) afforded 80 and 63% protection (n = 8, p less than 0.05), respectively, against the deleterious effects of electrolysis-induced OFR on left ventricular pressure and coronary flow. The increase in left ventricular end diastolic pressure used here as an index of heart failure did not occur in the presence of 0.25 microM CP. Moreover, CP significantly reduced the increase of norepinephrine washout in the effluent perfusate after electrolysis suggesting a protection against free radical-induced injury to sympathetic nerve endings.

Animals↗
PubMed1991

Simultaneous evaluation of medullary secretory functions of normal and acutely denervated adrenals.

Adrenal medullary secretory function of the right innervated gland was simultaneously compared with that of contralateral acutely denervated gland in anesthetized dogs. During bilateral carotid artery occlusion (BCO), output (in ng/min) from right innervated gland of epinephrine and norepinephrine increased from 86.6 +/- 33.0 and 34.4 +/- 15.1 to 280.8 +/- 86.7 (P less than 0.01, n = 7) and 104.4 +/- 40.6 (P less than 0.01, n = 7), respectively. By contrast, epinephrine output from left denervated gland increased only slightly (P less than 0.05), and norepinephrine did not increase significantly. Net catecholamine output from left denervated gland was markedly attenuated by approximately 90% (P less than 0.01, n = 7) compared with that from right innervated gland. During BCO in the second group of dogs, catecholamine output from sham-denervated left gland increased significantly (P less than 0.01, n = 7) to an extent slightly lower than that observed in right innervated gland. In the third group, intravenous injections of dimethylphenylpiperazinium (5 and 15 micrograms/kg) resulted in a dose-dependent increase (P less than 0.05, n = 7) in catecholamine output from both right innervated and left denervated gland. The results indicate that the present procedure of acute surgical adrenal denervation can eliminate the centrally mediated adrenal response, whereas the medullary secretory response to blood-borne substances remains intact. This model may be a useful tool for studying neuronal and humoral medullary secretory functions in vivo under various experimentally induced stress conditions.

Adrenal Glands↗
PubMed1991

123I-IMP brain SPECT imaging in a patient with the interval form of CO poisoning.

N-isopropyl-[123I]-p-iodoamphetamine (123I-IMP) single-photon emission computed tomography (SPECT) brain imaging was repeatedly performed in a 68-year-old man with the interval form of CO poisoning. The initial SPECT under an akinetic-mutism state following the interval period of about 18 days showed high-grade hypoperfusion images in diffuse regions extending to both the gray and white matter in the cerebral cortex. The second SPECT examination performed 328 days after the acute poisoning showed that the diffuse hypoperfusion images had become lighter but remained to a degree consistent with the delay in the recovery from the akinetic-mutism state. The high utility of SPECT brain imaging in determining the diagnosis or prognosis of CO poisoning was discussed in comparison with X-ray or magnetic-resonance imaging findings.

Aged↗
PubMed1991

Regional relationships between focal hypofixation images in 123I-IMP single photon emission computed tomography and epileptic EEG foci in interictal periods in patients with partial epilepsy.

Single photon emission computed tomographic (SPECT) brain scans with N-isopropyl-(iodine-123)-p-iodoamphetamine were performed in interictal periods in 40 patients with partial epilepsies and normal X-ray CT findings, and the regional relationships between the SPECT abnormalities and interictal epileptic EEG foci were studied. Twenty-six patients (65%) had abnormal SPECT images consisting of one or more focal hypofixation images, i.e., zones of decreased regional cerebral blood flow, while the remaining 14 patients showed normal images. Nineteen (73%) of the 26 patients showed complete or partial regional agreement between the abnormal SPECT findings and the interictal epileptic EEG foci determined from EEGs recorded repeatedly during their clinical course, while the regional relationships with the EEG foci determined from the single EEG recorded just after the SPECT scans or a short interval after the scans showed a lower rate of agreement (13 of 21 patients, 61.9%). These results confirm the utility of SPECT scans in the regional diagnosis of epileptic foci.

Adolescent↗
PubMed1991

Effect of therapy with oxygen under high pressure on regional cerebral blood flow in the interval form of carbon monoxide poisoning: observation from subtraction of technetium-99m HMPAO SPECT brain imaging.

Changes in brain images with single photon emission computed tomography (SPECT) using 99mTc hexamethylpropyleneamine oxime (HMPAO) before and after therapy with oxygen under high pressure (OHP) were measured in a 66-year-old man with the interval form of carbon monoxide (CO) poisoning by a new technique, i.e., subtraction of brain images. This study was performed 187 days after acute CO poisoning, in a state of chronic akinetic mutism that followed a lucid interval. A diffuse, but frontal-dominant, hypoperfusion pattern involving both the gray and white matter was observed in the pre-OHP SPECT image. After OHP, regional cerebral blood flow increased in both the gray and white matter and markedly increased in the frontal cortical regions. The present finding suggests that OHP is effective against the chronic state of the interval form of CO poisoning.

Aged↗
PubMed1991

Incidence of aneurysms in Takayasu's arteritis.

The angiographic findings of Takayasu's arteritis in a series of 113 patients were reviewed. Predominant findings were stenotic or occlusive changes, but fusiform or saccular aneurysms were also found in 36 patients (31.9%) in the various sites of aorta and its major branches. Multiple aneurysms were found in 15 patients. The most common site of aneurysms was the ascending aorta (16 patients); in 7 of the patients these were complicated by aortic regurgitation. Aneurysms developed in the aortic arch in 3 patients, in the descending aorta in 11, in the abdominal aorta in 7, and in the major branches of the aortic arch in 9 patients. In 2 patients, follow-up angiograms showed enlargement of the aneurysms, and rupture of the aneurysm occurred in 1 patient. Aneurysms were found even in young patients. A fifteen-year-old female showed a huge aneurysm in the ascending aorta as the initial manifestation of this disease. Thickening of the walls of aneurysms was common and characteristic. This study revealed the moderately high incidence of aneurysms of various sites of arteries in patients with Takayasu's arteritis. The authors conclude that aneurysm, as well as occlusive changes, can be a primary lesion.

Adolescent↗