Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 631 records · Page 35Linked to original sources

PubMed1989

[Immune response against Chlamydia trachomatis inoculation in mice--changes in interferon activity, antibody titers and weight of the spleen as parameters of infection].

We examined the immune response against Chlamydia trachomatis (serovar L2) inoculation in mice by measuring the serum interferon (IFN) level, 2'-5'A synthetase (2-5A(S] activity, antibody titers (IgM, IgG) and the spleen weight as parameters of infection. The interferon activity was detected 6 hrs (400 U/ml) and the activity peaked 12 hrs (450 U/ml) after inoculation, and then gradually decreased thereafter (24 hrs: 12 U/ml, 36 hrs: undetectable). It was found that Chlamydia trachomatis induces IFN as well as bacteria. To monitor the behavior of IFN action after serum IFN was cleared, 2-5A(S) activity in the spleen cell extract was measured. It was found that the activity reached its peak 1 to 2 days after inoculation and then decreased as well as in infectivity of Chlamydia trachomatis. The activity however was almost not detected in sera of mice after inoculation of heat-inactivated Chlamydial organism (56 degrees C, 10 min). This may indicate that intact Chlamydial organisms were required for induction of IFN. IFN induced in mice was stable in pH 2.0 treatment and IFN induced by Newcastle disease virus inhibited growth of Chlamydia trachomatis in L929 cell cultures in a dose-dependent manner. The weight of the spleen gradually increased and reached its peak (2- to 3-fold of the control) in 3 to 5 days after inoculation, and then gradually decreased to the control level. IgM and IgG antibodies to Chlamydia trachomatis were detected by immunofluorescence method and enzyme-linked immunosorbent assay, respectively. The antibody IgM was detected as early as 2 days and reached its peak 3 to 4 days after inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

[A pathological study on herpes simplex virus infections in adults].

A pathological study was carried out in 200 autopsied cases experienced in our department from 1981 to 1988. Eight patients (4.0%) had herpes simplex virus (HSV) infections in their visceral organs. Another one patient was diagnosed as HSV hepatitis through necropsy of liver. The nine patients (five of them were male) ranged in age from 34 to 70 years (mean, 58). Four patients had non-Hodgkin's lymphoma, and the other included one with adult T-cell leukemia, one with multiple myeloma, one with idiopathic interstitial pneumonia and one with bronchial asthma, however, one did not have any underlying disease. Two patients died of HSV fulminant hepatitis and one died of HSV diffuse interstitial pneumonia. The most commonly involved organ was esophagus (7/8), followed by tongue (5/8), liver (3/9), spleen, pancreas, lymph node (2/8), and lung, adrenal, tonsil (1/8). Typical herpetic changes such as ballooning degeneration of cells, multinucleated giant cells, ground-glass nuclei and Cowdry type A intranuclear inclusions were observed at the margin of the ulcer or coagulation necrosis. Indirect immunoperoxidase stain revealed HSV-1 antigen in all of the 9 cases, HSV particles were demonstrated in 2. Seven patients had concomitant infections with one or more pathogens in addition to HSV, which included cytomegalovirus in 5, aspergillus in 4, candida in 3 and bacteria in 3.

Adult↗

PubMed1989

High-incidence of C9 deficiency throughout Japan: there are no significant differences in incidence among eight areas of Japan.

From 92,686 sera sent from hospitals throughout Japan to the Special Reference Laboratories for CH50 assay, we were able to classify 80 patients as C9-deficient using a sensitive screening test, as well as hemolytic and immunochemical C9 assays. The incidence of C9 deficiency was determined to be 0.086%, and there were no distinct differences among the eight areas of Japan tested. Serum CH50 levels of these C9-deficient patients varied widely (9.4-63.8 U/ml), and exhibited a higher value (average: 34.1 U/ml) than that of healthy C9-deficient individuals, probably due to elevated C3, C4, and C5 levels. These patients suffered from a variety of autoimmune, renal, and infectious diseases, which, however, are thought to be only incidentally associated with C9 deficiency.

Complement C9↗

PubMed1989

Regional cortical blood flow during extra-intracranial bypass surgery in young patients with moyamoya disease.

Regional cortical blood flow (rCBF) was measured with a thermal diffusion flow probe in 14 cortical regions of 12 young patients with moyamoya disease before and after completion of superficial temporal-middle cerebral artery anastomosis. The prebypass rCBF value was low in most patients, especially in the frontal regions. On temporary occlusion of the cortical artery during the surgical procedure, no significant drop in rCBF occurred. rCBF increased immediately after anastomosis in all but one region and continued to increase for 5-10 minutes in four of the eight regions measured. In the other four regions, rCBF declined gradually after the initial increase, and the final increase was slight. The average increase in rCBF was significant at 1-2 minutes and at 5-10 minutes after anastomosis. However, the latter increase did not bring the flow into the normal range. It may be that the initial increase in postbypass rCBF is determined solely by the pressure gradient between the donor and recipient arteries, and that subsequent rCBF is controlled by other factors within the brain. In one patient who underwent double anastomoses to the frontal and temporal lobes, neither anastomosis increased rCBF in the non-corresponding lobe to recipient artery. This suggests that there is no direct connection between supra- and infra-Sylvian arteries and supports the concept of nonuniform epicerebral microcirculation in moyamoya disease.

Adolescent↗

PubMed1989

Subependymoma of the septum pellucidum radiologically indistinguishable from cavernous angioma--case report.

A case of subependymoma of the septum pellucidum in a 54-year-old female is presented. Computed tomography and magnetic resonance imaging revealed a partially calcified mass with intratumoral hematomas, and cerebral angiograms disclosed a relatively hypovascular lesion. Preoperatively, a cavernous angioma was suspected. The tumor was removed, and histological examination proved it to be a subependymoma containing a fine fibrillary matrix. On immunohistochemical analysis, both the matrix and the tumor cells were positive for glial fibrillary acidic protein staining.

Brain Neoplasms↗

PubMed1989

Comparison of dynamic and xenon computed tomography in the evaluation of cerebrovascular ischemia.

Dynamic computed tomographic (DCT) scans with iodine contrast enhancement were compared with simultaneously obtained xenon CT studies of cerebral blood flow (CBF) in 15 patients with subacute or chronic cerebrovascular ischemic disease. Specifically, the width and corrected first moment (cMT1), as demonstrated by DCT, were compared with the regional CBF (rCBF) data and the rCBF map obtained with xenon CT. The DCT and rCBF images were well correlated in patients without, but poorly correlated in those with, leptomeningeal anastomotic collateral circulation. The correlation of rCBF and 1/width with 1/cMT1 was significant (r = 0.78, p less than 0.01) in the former, but not in the latter. These data were thought to reflect a difference in the tracer inflow pattern between the patients with and those without leptomeningeal anastomoses. Our series did not include patients with acute cerebral infarction or recanalization, which are thought to be associated with marked changes in cerebral blood volume in the affected region. However, the influence of cerebral blood volume should be studied in detail in our subacute or chronic series.

Brain Ischemia↗

PubMed1989

Regional cerebral blood flow and oxygen metabolism in normal pressure hydrocephalus after subarachnoid hemorrhage.

To clarify the pathophysiology of normal pressure hydrocephalus (NPH) after subarachnoid hemorrhage, the authors measured cerebral blood flow (CBF), cerebral oxygen metabolic rates (CMRO2), the cerebral oxygen extraction fraction (OEF), and cerebral blood volume (CBV) in eight normal volunteers, six SAH patients with NPH, and seven patients without NPH by 15O-labeled gas and positron emission tomography (PET). In the NPH group, PET revealed a decrease in CBF in the lower regions of the cerebral cortex and a diffuse decrease in CMRO2. The decrease in CBF in the lower frontal, temporal, and occipital cortices was significantly greater in the NPH than in the non-NPH group. Reduction of CMRO2 was also more extensive in the NPH group, and both CBF and CMRO2 were more markedly decreased in the lower frontal region. OEF was increased in all areas in both of the patient groups, but the increase was not significant in most areas. CBF, CMRO2 and OEF did not significantly differ between the non-NPH group and the normal volunteers. There was no significant difference in CBV among the three groups. These results indicate that NPH involves impairment of cerebral oxygen metabolism in the lower regions of the cerebral cortex, particularly in the lower frontal region.

Brain↗

PubMed1989

Serum amphotericin B concentration in a very premature infant with disseminated candidiasis.

A 1,040-g premature baby was diagnosed to have disseminated candidiasis and treated with amphotericin B (AMB) and 5-fluorocytosine. During the treatment, an unexpectedly large dose of AMB was infused unintentionally. AMB level was as high as 1.73 micrograms/mL soon after 5 mg/kg infusion instead of 0.5 mg/kg. However, it dropped rapidly to 0.83 micrograms/mL after 24 hours. AMB was detected in patient's serum at a higher level than minimal inhibitory concentration as long as one month after treatment was stopped. The patient showed liver dysfunction but no nephrotoxicity. The further studies are needed to establish safe and effective treatment regimen in premature infants with disseminated candidiasis.

Amphotericin B↗

PubMed1989

Degradation of neurofilament protein in cerebral ischemia.

Degradation of neurofilament (NF) triplet proteins: NF200 (molecular weight (MW) 200,000), NF150 (MW 150,000), and NF68 (MW 68,000) as well as of other cytoskeletal proteins in the rat brain during ischemia was investigated. Sodium dodecyl sulfate-gel electrophoresis and immunoblot methods with anti-NF200 antibody were used for the study. Selective degradation of NF200 and NF150 was observed during the initial 10 to 15 minutes of ischemia. The degradation was demonstrated both in permanent ischemia caused by decapitation and in transient ischemia induced by four-vessel occlusion followed by reperfusion after 30 minutes of occlusion (modified Pulsinelli method). The degradation suggests that the activation of a protease occurs in the first 15 minutes of cerebral ischemia, which is the earliest irreversible neuronal change ever to be reported.

Animals↗

PubMed1989

Changes in xanthine oxidase in ischemic rat brain.

Xanthine oxidase activity in the rat brain was measured by means of high-performance liquid chromatography with electrochemical detection of uric acid. Cerebral ischemia was produced by a four-vessel occlusion method. In the control rat, the enzyme activity was 0.87 +/- 0.13 nmol/gm wet weight/min at 25 degrees C (mean +/- standard deviation), of which 92.4% was associated with the nicotinamide adenine dinucleotide (NAD)-dependent dehydrogenase form and only 7.6% with the oxygen-dependent superoxide-producing oxidase form. However, the ratio of the latter form increased to 43.7% after 30 minutes of global ischemia, despite the total xanthine oxidase activity remaining the same. Thus, it was revealed that uric acid can be synthesized in the rat brain and that cerebral ischemia induced the conversion of xanthine oxidase from an NAD-dependent dehydrogenase to an oxygen-dependent superoxide-producing oxidase. Although the xanthine oxidase pathway has been proposed as a source of oxygen-derived free radicals in various ischemic organs other than brain, the results of the present study suggest the involvement of the oxygen free radicals generated from this pathway in the pathogenesis of the ischemic injury of the rat brain.

Animals↗

PubMed1989

Lipid peroxidation in focal cerebral ischemia.

To verify whether lipid peroxidation is associated with focal cerebral ischemia, a unilateral middle cerebral artery occlusion was carried out in rats. The concentrations of various endogenous antioxidants in the ischemic center were measured, including alpha-tocopherol and ubiquinones as lipid-soluble antioxidants and ascorbate as a water-soluble antioxidant. At 30 minutes after ischemia, alpha-tocopherol decreased to 79% of baseline, reduced ubiquinone-9 to 73%, ubiquinone-10 to 66%, and reduced ascorbate to 76%. Six hours after ischemia, alpha-tocopherol decreased to 63% and reached a plateau, whereas reduced ubiquinones and reduced ascorbate declined further to 16% and 10%, respectively, 12 hours after ischemia and then reached plateau levels. These results suggest functional and durational differences between antioxidants and lipid peroxidation in this ischemic model. Although the reciprocal increase in oxidized ubiquinones during ischemia was not observed, that of oxidized ascorbate was noted. The complementary antioxidant system between cytoplasmic and membranous components, the combination alpha-tocopherol/ascorbate, was estimated from the calculated consumption ratio of these antioxidants on the basis that the loss of these reduced antioxidants is due to neutralization of free radicals. This system is suggested to play an important role in the early ischemic period. Urate also increased during ischemia. The possible involvement of the xanthine-xanthine oxidase system in initiating free radical reactions in cerebral ischemia is also discussed.

Animals↗

PubMed1989

Relaxant effect of calcitonin gene-related peptide on cerebral arterial spasm induced by experimental subarachnoid hemorrhage in dogs.

This study examines the relaxant effect of calcitonin gene-related peptide (CGRP), a 37-amino acid peptide with a potent vasodilator action, on cerebral arterial spasm after subarachnoid hemorrhage (SAH). The spasm was induced by injecting autologous arterial blood percutaneously into the cisterna magna in adult mongrel dogs. The single-injection model of SAH was produced by injection of 1.0 ml/kg body weight of blood (on Day 0), and the double-injection model involved two successive injections of 0.5 ml/kg body weight of blood made 48 hours apart (on Day 0 and Day 2). On vertebral angiograms, arterial narrowing of the major cerebral arteries was most prominent on Day 3 after SAH in the single-injection model and on Day 7 in the double-injection model. When 10(-10) mol/kg of CGRP was administered intracisternally in the single-injection model on Day 3, the diameter of the spastic cerebral arteries, as determined by angiography, recovered to normal. After intracisternal administration of 10(-11) to 2 X 10(-10) mol/kg of CGRP on Day 7 in double-injection models, spastic cerebral arteries dilated in a dose-dependent manner. The dilatory effect of CGRP continued for a few hours after administration. The results suggest that CGRP injected intracisternally may reverse cerebral arterial spasm after SAH.

Animals↗

PubMed1989

Murine intracerebral interleukin-2 injection: pathological and immunological effects.

The authors have investigated whether specific pathological changes and antibodies against interleukin-2 (IL-2) are induced after intracerebral administration of recombinant IL-2 (rIL-2). In addition, IL-2 receptor (IL-2R) expression was checked on the cell surface of normal brain tissues before and after the intracerebral infusion. Reconstituted rIL-2 (specific activity 1.2 x 10(7) U/mg protein) was injected into the right cerebral hemisphere of normal adult C57BL/6 mice in three different dose groups, each receiving single or multiple infusions of 8, 32, or 80 U. In sham control experiments, mouse albumin purified by gel filtration and ion exchange chromatography and adjusted to the same concentration of protein as rIL-2 was injected into mice at various doses. Anti-IL-2 antibodies were measured by an enzyme-linked immunosorbent assay concurrently with assessment of IL-2 activity in serum. The IL-2R expression was determined by using immunofluorescence techniques with monoclonal antibodies against mouse IL-2R. Since histological alteration after rIL-2 injection did not differ from that in the sham control preparations, it seems that there is no direct toxic action of rIL-2 on normal brain tissues. Interleukin-2 antibodies were produced at low levels only in mice injected repeatedly at the maximum dose, and levels were insignificant in other groups. Serum levels of IL-2 activity remained low. The IL-2R expression within the brain was not enhanced within 8 weeks following the intracerebral administration of rIL-2, suggesting that direct intracerebral infusion of rIL-2 may be safely used in the immunotherapy of brain tumors.

Animals↗

PubMed1989

[Water sorption, solubility, MeOH sorption and THF sorption of visible light cured resin--on resin using cyclophosphazene monomers and commercial monomers].

Studies were done to decrease both the water sorption and solubility of visible light cured resin. As monomer, three kinds of cyclophosphazene monomers and three kinds of commercial monomers were prepared to the visible light cured unfilled resins. When these set products were immersed in water, MeOH and THF, water sorption and solubility in water, MeOH sorption and solubility in MeOH, THF sorption, and mechanical properties were examined. Water sorption was increased by degrees for all the monomers. In the cases of 4 PN-(EMA)8, 4 PN-(TF)1-(EMA)7, 4 PN-(TF)2-(EMA)6, Tri-EDMA, BMPEPP and Bis-GMA + Tri-EDMA, the value of solubility in water after 30 days, was 0.16, 0.20, 0.51, 0.65, 0.17 and 0.81% respectively. MeOH sorption showed a tendency to increase, except for Bis-GMA + Tri-EDMA and 4 PN-(TF)2-(EMA)6. Solubility in MeOH after 30 days, for cyclophosphazene monomers and commercial monomers, was 0.09-0.36% and 1.36-5.40%. THF sorption after 30 days, for cyclophosphazene monomers, was small in comparison with that of commercial monomers. Compressive strength was 230-275 MPa in all cases. But, transverse strength, for all the cyclophosphazene monomers, was 45 MPa or below. In the cases of commercial monomers, the value of transverse strength was 55-90 MPa.

Acrylic Resins↗

PubMed1989

[Molecular analysis of mouse major histocompatibility complex class I gene expression of tumors growing in the brain].

The authors have investigated the regulation of mouse major histocompatibility complex (MHC, H-2) class I gene expression of tumors growing in the brain, by using T-cell lymphoma (Moloney leukemia virus-induced YAC-1 of A/Sn mouse origin) and its cell surface H-2 negative variants, A. H-2- and beta 2m-. FACS analysis showed that low H-2 expressing YAC-1 markedly increased H-2 Kk, Dd and beta-2 microglobulin (beta 2m) induction on the cell surface after intracerebral (i.c.) passage, while there was no change in phenotypical expression of both A. H-2- and beta 2m-. Southern and Northern blot analyses revealed that the enhancement of H-2 class I expression in YAC-1 was due to transcriptional control of H-2 DNA genes. beta 2m- was confirmed to lack beta 2m- gene, causing cell surface H-2 negative expression. Immunoprecipitation method showed that, despite increase in mRNA of the H-2 gene, A. H-2- disclosed no class I H-2 expression because of the incapability of intracellular association of polypeptides between H-2 and beta 2m in the post-translational level. The H-2 class I expression on YAC-1 cells could also be induced by interferon gamma (IFN) in a dose-dependent manner in the range of 1 to 100 U/ml. At 100 U/ml, the H-2 inducing effect, regulated at the transcriptional level, was comparable to that observed after i.c. passage. In contrast, the A. H-2- and beta 2m- remained completely negative after IFN treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

Recombinant interferon-gamma is a potent inhibitor of osteoblastic cell functions.

Interleukin-1 and tumor necrosis factor-stimulated bone resorption is mediated by osteoclast-activating factor elaborated by osteoblasts. Recombinant interferon-gamma inhibits stimulation of bone resorption by these cytokines. We examined here the effects of recombinant mouse interferon-gamma (rmIFN-G) on DNA and collagen synthesis, and on alkaline phosphatase (ALP) activity, in the osteoblastic cell line (MC3T3-E1) under confluent culture conditions. Addition of rmIFN-G to the cells markedly inhibited their DNA synthesis and ALP activity in dose- and culture time-related manner. Also we found that rmIFN-G decreased markedly collagen synthesis at day 3 after addition of the agent. These data indicate that rmIFN-G is a potent inhibitor of osteoblastic cell functions.

Alkaline Phosphatase↗

PubMed1989

[The application of vascular endoscope for the extracranial cerebrovascular occlusive disease: the development of the endoscopic system].

Flexible thin fiber catheter is applied as vascular endoscope for occlusive lesions in the extracranial cerebral arteries. This fiber catheter is introduced transfemorally through 6 or 7 french-sized double lumen balloon catheters. Vascular endoscope clearly demonstrates the internal surface of these vessels by transient occlusion of the proximal side of the vessel through balloon inflation. The occlusive lesions in the subclavian artery or in the proximal vertebral artery were revealed as round smooth-surfaced mass to be treated by the percutaneous transluminal angioplasty.

Aged↗

PubMed1989

[Results of conventional radiotherapy in malignant gliomas:].

Results of radiotherapy for 164 supratentorial malignant gliomas were analyzed based on recent histological subclassification into glioblastoma multiforme (GBM) and anaplastic astrocytoma (AA). Patients with AA had a better prognosis than those with GBM. The 5-year survival rate was 1% for GBM and 16% for AA. The size of radiation field did not influence survival significantly, and whole brain radiation appeared of no benefit. Survival time prolonged with an increase of radiation dose between 45 Gy and 72 Gy. The optimal radiotherapy for the disease is discussed.

Adolescent↗