Search PubMed⌕ Search

Biomedical subjects

K Iijima

Publications and source records attributed to K Iijima.

At least 217 records · Page 12Linked to original sources
PubMed1991

An immunocytochemical study using the PAP method for tyrosine hydroxylase and serotonin in alternate sections, and in situ hybridization to detect tryptophan hydroxylase mRNA in the rat's locus ceruleus.

In situ hybridization (LARRSON and HOUGAARD 1990), using the APAAP complex, shows that many small and medium-sized neurons with signals of tryptophan hydroxylase mRNA are uniformly scattered throughout the rat's locus ceruleus, and that a few extrinsic neurons just ventro-medial to it also shows the hybridization signals. The specificity of this technique has been established by Northern blot hybridization. Synthesis of serotonin in intrinsic neurons is indicated not only by the results obtained from in situ hybridization, but also by the fact that, in distribution, masked serotonin cells, immunocytochemically revealed after pargyline and 5-hydroxytryptophan loading, correspond to the neurons showing mRNA hybridization signals. Identification of the same neurons in adjacent cryostat sections, immunostained alternately for serotonin or tyrosine hydroxylase after loading, provides evidence for the coexistence of serotonin and noradrenaline in a single neuron of this center. A few extrinsic, non-specific indoleamine cells located just ventro-medial to the center may be related to the lateralization of the raphe's neurons. The expression of tryptophan hydroxylase in CNS appears to be restricted to the specific regions such as the locus ceruleus and raphe's nuclei.

Animals↗
PubMed1991

Evaluation of analgesic effect of low-power He:Ne laser on postherpetic neuralgia using VAS and modified McGill pain questionnaire.

In order to investigate the efficacy of low-power He:Ne laser in treatment of pain, we irradiated 18 outpatients with severe postherpetic neuralgia. The efficacy of the low-power laser treatment was evaluated using a four-grade estimation, visual analog scale (VAS), and modified McGill pain questionnaire (m-MPQ) after every 10 of as many as 50 irradiations. The efficacy rate using a four-grade estimation at the end of 50 treatments was 94.4%. VAS decreased from 6.2 before irradiation therapy to 3.6 after 50 treatments, and the degree of pain relief was reduced to 44.6% and correlated with the number of treatments. The total numbers of words and the total scores of the m-MPQ decreased as the number of treatments increased. No complications attributable to the laser therapy were observed. These results suggest that repeated irradiation with low-power He:Ne laser is an effective and safe therapy for postherpetic neuralgia.

Adult↗
PubMed1991

Red and green low-powered He-Ne lasers protect human erythrocytes from hypotonic hemolysis.

The effect of low-powered He-Ne lasers (red beam, 632.8 nm, 10.2 mW, and green beam, 543.5 nm, 0.44 mW) on hypotonic hemolysis in human red cells was investigated. Red cell solutions (0.9% NaCl, pH 7.00) were centrifuged and the sediments were irradiated with the red or the green beam for 0 (control), 1, 3, 5, 7, 10, 15 and 30 minutes. Each of the 40 irradiated samples were transferred into hypotonic solution (0.405% NaCl, pH 7.00). After leaving the samples at room temperature for 10 minutes, optical density of every suspension was measured spectrophotomechanically at a wavelength of 545 nm to determine hemoglobin content. Hemolysis percentages of the control samples in hypotonic solution were 52.2 +/- 10.7% (mean +/- SD, N = 20) in the red group and 55.0 +/- 12.0% (N = 20) in the green group. Relative values of hemolysis in the hypotonic solution after irradiation with the red or the green beam decreased significantly between the 7- and 30-minute irradiation. These results demonstrate that low-powered He-Ne lasers have a protective effect on red cell membranes from hypotonic hemolysis and stabilize the cell membranes.

Erythrocyte Membrane↗
PubMed1991

Intracellular signaling pathway of endothelin-1.

The intracellular signaling pathway of endothelin-1 (ET-1) was studied in individual mesangial cells (MCs) and vascular smooth muscle cells (VSMCs) using microspectrofluorimetry of fura-2 ([Ca2+]i), SPQ ([Cl-]i), and bisoxonol (membrane potential). ET-1 elicited a five-fold increase in [Ca2+]i that showed immediate and sustained phases. Both the Ca(2+)-free medium and nifedipine pretreatment curtailed the sustained phase of the response to ET-1. ET-1 resulted in sustained membrane depolarization of MCs and VSMCs. This depolarization was not attributed to Na influx, as Na-free medium did not abolish it. A Cl(-)-channel inhibitor, IAA-94, blunted the depolarization and sustained elevation of [Ca2+]i in response to ET-1. In aortic rings, both nifedipine and IAA-94 attenuated ET-1-induced contraction. No additivity in the effect of nifedipine and IAA-94 was detected. Studies of SPQ fluorescence changes induced by ET-1 revealed an immediate and sustained increase in fluorescence intensity consistent with the decrease in [Cl-]i. The sustained but not immediate increase in SPQ fluorescence was virtually abolished in Ca(2+)-free medium with or without pretreatment with the intracellular Ca2+ chelator BAPTA. In conclusion, we hypothesize that ET-1 results in Ca2+ mobilization and Ca(2+)-dependent and -independent activation of Cl- channels. Ensuing Cl- efflux causes membrane depolarization and, in turn, activation of voltage-gated Ca2+ channels in MCs and VSMCs. The latter results in sustained elevation of [Ca2+]i that is indispensable for the full-scale contractile response to ET-1.

Animals↗
PubMed1991

Role of endothelin in the development of Dahl hypertension.

To evaluate the possible role of endothelin in the development and/or maintenance of hypertension in Dahl rats, we examined the responsiveness of isolated vascular smooth muscle and glomerular mesangial cells, as well as deendothelialized vascular ring preparations to endothelin-1 (ET-1). Production of immunoreactive endothelin (ir-ET) was studied in freshly isolated glomeruli and renal medullary slices. Both glomerular mesangial cells and vascular smooth muscle cells obtained from prehypertensive Dahl-S rats exhibited an exaggerated [Ca2+]i response to ET-1, as compared with cells obtained from Dahl-R rats. This was paralleled by the enhanced isometric contraction of vascular rings obtained from prehypertensive Dahl-S rats. ir-ET production was doubled in response to 0.1 mM ouabain in tissue samples obtained from prehypertensive Dahl-S, but not Dahl-R rats. This effect was not observed in tissues obtained from animals fed a 4% NaCl diet (hypertensive). Immunocytochemistry of ET distribution in the outer medullary stripe showed approximately a 40% higher fluorescence intensity in sections obtained from Dahl-S rats fed 4% NaCl diet as compared with Dahl-R rats fed the same diet. Northern blot analysis of poly(A)+ RNA extracted from medullae of prehypertensive Dahl-S and -R rats using a full-length cDNA probe for rat ET-1 revealed a marginal induction of pre-pro-ET-1 message in Dahl-S samples after 30 and 60 min of incubation with 0.1 mM ouabain. In conclusion, increased responsiveness of target cells to ET-1 and inducibility of ir-ET production in prehypertensive Dahl-S rats are in favor of a possible role of this peptide in the pathogenesis of Dahl hypertension. We hypothesize that ouabain-like factor(s) may trigger production of ET, thus serving as a link between high-salt intake and the development of hypertension in Dahl-S rats.

Animals↗
PubMed1991

Intracellular ramification of endothelin signal.

Effects of porcine 1-21 endothelin (ET-1) on [Ca2+]i, [Na+]i, and [Cl-]i and on membrane potential were studied in individual mesangial (MC) and vascular smooth muscle (VSMC) cells using microspectrofluorimetry of fura-2, SBFI, SPQ, and bis-oxonol, respectively. ET-1 increased [Ca2+]i by fivefold, showing an immediate and a sustained phase of response. Ca(2+)-free medium and nifedipine pretreatment significantly curtailed the sustained phase of response to ET-1. These findings were confirmed in studies of vascular ring preparations, demonstrating that Ca2+ influx may account for at least 50% of contraction. ET-1 caused immediate and sustained depolarization of MC and VSMC. This could not be attributed to Na+ influx, since fluorescence of SBFI was not affected by ET-1 and Na(+)-free medium did not abolish the ET-1-induced membrane depolarization. Studies of SPQ fluorescence changes induced by ET-1 revealed an increase in fluorescence intensity consistent with the decrease in [Cl-]i. A Cl- channel blocker, IAA-94, abolished changes in SPQ fluorescence and curtailed sustained phases of membrane depolarization and [Ca2+]i elevation in response to ET-1, but did not affect KCl-induced [Ca2+]i transients. IAA-94 also attenuated the ET-1-induced contraction of aortic rings. Microinjection of either calcium gluconate or inositol 1,4,5-trisphosphate (IP3) in SPQ-loaded cells resulted in an increase in fluorescence mimicking the effect of ET-1. These changes were blunted by pretreatment of cells with BAPTA and incubation in Ca(2+)-free medium. When IP3 was microinjected into fura-2-loaded MC, this resulted in immediate and sustained elevation of [Ca2+]i. In conclusion, generation of IP3 results in mobilization of intracellular Ca2+ stores and activation of Cl- channels. Ensuing Cl- efflux causes membrane depolarization and, in turn, activation of voltage-dependent Ca2+ channels, resulting in sustained elevation of [Ca2+]i which is indispensable for the full-scale contraction produced by ET-1.

Animals↗
PubMed1991

Syncytial organization of cultured rat mesangial cells.

To investigate communication competence of cultured rat mesangial cells, Lucifer yellow transfer was studied using microinjection and scrape-loading techniques. Both methods yielded results indicating considerable gap junctional communication between cultured mesangial cells. Gap junctional communication between mesangial cells was upregulated by adenosine 3',5'-cyclic monophosphate (cAMP). Conversely, cell-to-cell communication was attenuated by exposure to the tumor promoter phorbol myristate acetate, the Ca ionophore ionomycin, reduced oxygen intermediates, and cell acidification. Expression of voltage gated calcium channels by mesangial cells was studied microspectrofluorimetrically using fura-2 fluorescence. KCl-induced depolarization, BAY-K 8644, and readdition of calcium to Ca-free depolarizing medium all produced a nifedipine-inhibitable increase in cytosolic calcium concentration. The existence of voltage-gated calcium channels in communication-competent cells suggests the possibility of propagation of depolarizing signals across the syncytium. This was studied by microapplication of KCl to the microenvironment of a single cell and monitoring fura-2 fluorescence in remote cells. This maneuver resulted in propagating calcium waves in communication-competent monolayers; calcium waves could not be evoked in monolayers exposed to an alkanol-type gap junction uncoupler, octanol. It is concluded that cultured rat mesangial cells form a syncytium capable of propagating calcium transients from a single depolarized cell to its coupled neighbors.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1991

[Fibromyalgia (fibrositis) syndrome--a case report].

A 25-year-old woman was admitted in our hospital with back pain and both hip joint pain. Pain was abruptly occurred from the beginning of March 1990. Physical examination revealed wide spread pain (occipital area, both shoulder, lumber area, bilateral gluteal area, inguinal area, both Achilles-plantar area) and more than 12 tender points (occiput, trapezius, second rib, supraspinatus, gluteal, greater trochanter, hip joints, pubic bone). Laboratory examination showed no abnormal findings except ANF (1:160). Any examination including X-ray, bone scintigraphy, CT and MRI did not disclose spondylitis, sacroiliitis and enthesopathy. She was diagnosed as primary fibromyalgia/fibrositis syndrome. Treatment with maprotine hydrochloride (30 mg/day) and phenobarbital (120 mg/day) brought approximately 1/3 reduction of pain and tenderness. Psychoanalysis revealed that she had psychological conflicts against her parents and her colleagues at the work. EEG showed a borderline record with irregular basic pattern and 14 & 6 Hz positive burst at the sleep stage. Although the newly proposed criteria for the classification of fibromyalgia was proposed by ACR, fibromyalgia/fibrositis syndrome has been seldom discussed in the Japanese literature. As this syndrome is frequently associated with various rheumatic diseases, hypothyroidism and malignant diseases, we should pay much more attention to understand this syndrome.

Adult↗
PubMed1990

A new enzymatic assay for evaluating the clearance of immune complexes from the circulation of mice.

A new photometric in vivo enzymatic immune complex clearance (EIC) assay was developed in a homologous system using glucose oxidase-anti-glucose oxidase complexes (GAG) as a model of immune complexes. Chromatographically purified GAG was injected into mouse tail veins and at intervals thereafter the enzyme activities of GAG remaining in the circulation were estimated. The GAG were cleared in a size dependent manner and were stable, being eluted as the same discrete peaks on HPLC size-exclusion chromatography both before and after injection into mice. The complement consuming activity of the GAG was weak, and depletion of complement components with cobra-venom factor did not alter clearance of the GAG from the circulation, whereas pretreatment of aggregated mouse gamma globulin suppressed the clearance rate. These results suggested that most of the GAG were not cleared via complement receptors but via FcR. Normal clearance rates were significantly changed by administration of immunomodulators such as carrageenan or LPS. Intravenous administration of GAG at a dose 50 times higher than normal caused no deaths suggesting that the complexes were of low toxicity. The enzymatic method presented should be of value for measuring the function of the mononuclear phagocytic system with respect to immune complex clearance. It provides a rapid and sensitive alternative assay which avoids using radioisotopes.

Adult↗
PubMed1990

The distribution of serotonin immunoreactivity in the rat locus ceruleus after intraventricular injections of either 5,6- or 5,7-dihydroxytryptamine with special reference to serotonin synthesis.

The localization of serotonin-immunoreactivity (5-HT-IR) in the locus ceruleus (LC) of rats was studied by the peroxidase-anti-peroxidase method using a purified antibody obtained from a rabbit. Antibody production was performed according to the method of Grota and Brown (1974). The antibody was applied to serial cryostat sections with alternate counterstaining by cresyl violet, after intraventricular injections of 5,6-dihydroxytryptamine or 5,7-dihydroxytryptamine prior to treatment with pargyline and a precursor of 5-HT. The majority of LC neurons were immunopositive, and more than half of all LC neurons clearly showed 5-HT-IR. Although core cells were the most predominant, all types of neurons were immunopositive, and randomly scattered throughout the LC. The uptake inhibitor, Lilly 110140, administered in sufficient amounts prior to an injection of pargyline, did not reduce 5-HT-IR within the LC. The results suggest that LC neurons receive 5-hydroxytryptophan (5-HTP) through an afferent vascular-neuronal channel and/or by diffusion from blood capillaries much more than 5-HT itself. We consider from these results that all types of LC neurons throughout the nucleus are masked 5-HT cells, and that the majority of LC neurons utilize blood-borne 5-HTP as an immediate precursor for intraneuronal 5-HT synthesis.

5,6-Dihydroxytryptamine↗
PubMed1990

Livebirth prevalence and follow-up of malformation syndromes in 27,472 newborns.

The results of a survey of the birth prevalence of congenital anomalies among 27,472 consecutive newborn babies at a large maternity hospital in Tokyo are reported. There were 29 cases with trisomy-21; 5 cases with trisomy-13 syndrome; 5 with trisomy-18 syndrome; 2 with cri-du-chat syndrome; and one each with partial monosomy 4p, partial trisomy 5p, partial trisomy 6p, partial trisomy 9p, partial trisomy 9q, partial monosomy 10p, and partial monosomy 13q. Single cases of the following were observed: the Hallermann-Streiff syndrome, the Treacher-Collins syndrome, achondroplasia, arthrogryposis, the Beckwith-Wiedemann syndrome, the asplenia syndrome, the Klippel-Trenaunay-Weber syndrome, the Marfan syndrome, the Carpenter syndrome, the Goldenhar syndrome, and the Pierre Robin syndrome. The results of follow-ups to determine the life-prognosis of each patient with an autosomal aberration are reported.

Chromosome Aberrations↗
PubMed1990

Immune abnormalities and clinical course in childhood IgA nephropathy.

Immunoglobulin production by peripheral blood mononuclear cells (PBMC) and lymphocyte subpopulations were studied in 56 children with IgA nephropathy (IgAN) and 22 healthy controls. All the patients had persistent proteinuria at the time of diagnosis, and were divided into three clinical groups on the basis of urinary findings at the time of examination: 27 patients had proteinuria with or without microscopic hematuria (group A; active stage), 9 had microscopic hematuria only (group B; healing stage) and 20 had normal urine (group C; remission stage). PBMC from the patients in group A cultured without mitogenic stimulation produced significantly more IgA and IgG than those from controls (p less than 0.05). After polyclonal B cell stimulation with pokeweed mitogen (PWM), PBMC from patients in group A produced significantly more IgA than those from group B (p less than 0.05), group C (p less than 0.05) or controls (p less than 0.01), and produced significantly more IgG than those from group B (p less than 0.05) or controls (p less than 0.01). However, there was no significant difference in PWM-stimulated IgG production between groups A and C. PWM-stimulated PBMC from patients in group C produced significantly more IgA and IgG than those from controls (p less than 0.05). There were no significant differences in lymphocyte subpopulations among groups A, B and C and controls. These findings show that the clinical course of childhood IgAN is correlated with IgA production by PBMC suggesting that overproduction of IgA might be responsible for the pathogenesis of IgAN in children.

Adolescent↗
PubMed1990

[Continuous hepatic arterial infusion chemotherapy using implantable reservoir in liver metastases from colorectal cancer].

Continuous hepatic arterial infusion chemotherapy using implantable reservoir was performed for liver metastases from colorectal cancer, and the therapeutic effects, side effects, and complications were evaluated. 9 patients with unresectable liver metastases were as follows, 1. Group A; 3 patients, MMC 2 mg.one shot + 5-FU 250 mg/day.continuous infusion x 14 days, and then 5-FU tablets 150 mg/day.p.o. x 14 days, 2. Group B; 4 patients, MMC 2 mg.one shot + 5-FU 500 mg/day.continuous infusion x 7 days, and then 5-FU tablets 150 mg/day.p.o. x 14 days, 3. Group C; 2 patients, 5-FU 500 mg/day.continuous infusion x 14 days, and then free from agents for 14 days. In 2 of 3 group A patients, the catheters became dislocated and one died of perforation of duodenum. In group A and group B, no severe side effects were noted. But both of group C patients showed nausea, vomiting and diarrhea. In 8 of 9 patients (89%), serum CEA level fell below the preoperative level. In 4 of 7 patients who underwent CT scan, the size of the tumor regressed. Total infused dose of 5-FU was 8.17 +/- 7.56 g in group A, 16.9 +/- 2.88 g in group B, and 21.0 +/- 9.90 g in group C on average. In 2 patients of group B, therapy was repeated seven times.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[The effect of filler content on properties of polyaddition-type silicone impression material].

The effect of quartz filler content on viscosity, dynamic viscoelasticity and tensile stress of polyaddition-type silicone impression materials were investigated. A hydrogen polydimethylsiloxane (H-silicone) and two vinyl polydimethylsiloxane (V-silicone) silicone prepolymers were prepared. Quartz fillers were mixed to them at contents between 0 and 50% by weight. The viscosity of these rubber compounds and mechanical properties of set materials were measured by a cone and plate viscometer, the dynamic shear test and the tension test, respectively. Viscosity eta storage modulus G' and tensile stress sigma increased with the amount of filler increase. G' and sigma were decreased by use of a V-silicone prepolymer which had a high average molecular weight and the material was more flexible. This suggests that the characteristics of the silicone prepolymer greatly affect the mechanical properties of the impression materials. Therefore, the appropriate molecular design for silicone prepolymer and reasonable filler content should be considered to make impression materials that have suitable properties for clinical use.

Dental Impression Materials↗
PubMed1990

Repeat renal biopsy in children with IgA nephropathy.

Serial renal biopsy findings in 61 children with IgA nephropathy were correlated with their clinical course. At the time of the second biopsy, 23 patients showed clinical remission defined as complete disappearance of proteinuria and hematuria with normal renal function while 38 had persistent urinary abnormalities with normal renal function at the second biopsy. There were no differences between the two groups with regard to initial clinical findings and pathologic findings of the initial renal biopsy. The second biopsy of patients with clinical remission showed improvement of the glomerular changes on light microscopy, disappearance or diminution of IgA deposits in the mesangium and decrease of electron-dense deposits, whereas the second biopsy of patients with persistent urinary abnormalities showed progression of glomerular changes on light microscopy, persistence of mesangial IgA deposits and persistence of electron-dense deposits. Our study results show the importance of repeat renal biopsy in children with IgA nephropathy with persistent urinary abnormalities, as a progression of glomerular changes is common in these patients. These observations suggest that the deposition of IgA in the mesangium may be responsible for the glomerular damage in children with IgA nephropathy.

Adolescent↗