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Biomedical subjects

K Fukunaga

Publications and source records attributed to K Fukunaga.

At least 217 records · Page 12Linked to original sources
PubMed1992

[Clinical study of systemic juvenile rheumatoid arthritis (Still)].

Thirty-seven patients with systemic JRA were analyzed. Fifty four per cent of patients had mono-cyclic systemic type. Age at onset ranged from 6.0-6.8 years (median 6.4). Boys were more affected than girls (24/11). Cardiac involvement occurred in 10 patients (27%). Patients with cardiac troubles showed significantly much number of the white blood cell counts at admission and the max white blood cell count than those without cardiac troubles. Duration of positive CRP was shorter in patients with cardiac involvement who were all given cortico-steroid hormone those without cardiac involvement. This means that it is better to use steroid hormone early for patients with cardiac involvement. Patients with chronic arthritis type had higher elevated erythrocyte sedimentation rate and serum C3 level at admission and longer duration of positive CRP. We speculated that these date showed inflammation of joints. The onset subtype, which was determined by manifestations during the first 6 months of disease, was important for predicting clinical course and outcome.

Arthritis, Juvenile↗
PubMed1991

Crystal structure of 2-O-[(S)-2-hydroxypropyl]cyclomaltoheptaose.

2-O-[(S)-2-Hydroxypropyl]cyclomaltoheptaose crystallises in the monoclinic space group P2(1) with unit-cell dimensions a = 15.072(1), b = 10.409(1), c = 20.623(2) A, and beta = 108.52(1) degrees. The structure was solved by X-ray diffraction and refined to an R-value of 0.096. The macrocyclic ring of the cyclomaltoheptaose moiety is less symmetrical than that in cyclomaltoheptaose. The glucose residue that carries the hydroxypropyl group inclines much more with its primary hydroxyl side towards the inside of the macrocycle than the other glucose residues. The molecules are arranged in a herring-bone fashion to form a cage-type packing structure. The hydroxypropyl group is inserted into the cavity of an adjacent molecule related by a two-fold screw axis, and the hydroxyl group is linked to an HO-6 via OH...water...OH hydrogen bonds. The crystal contains 8.5 water molecules which occupy 11 sites. Two water molecules are included at the primary hydroxyl side of the cyclomaltoheptaose cavity.

Carbohydrate Conformation↗
PubMed1991

Ca2+/calmodulin-dependent protein kinase II immunoreactivity in Lewy bodies.

Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) is one of the predominant protein kinases in the brain. We found that CaM kinase II immunoreactivity was concentrated in the peripheral halos of Lewy bodies (LBs) in Parkinson's disease and Lewy body-like hyaline inclusions (LBHIs) in amyotrophic lateral sclerosis. An immunoelectron microscopic examination of LBs revealed that the filaments at the periphery of LBs were decorated with immunopositive deposits. Since CaM kinase II has a broad substrate specificity and can phosphorylate neurofilaments and other cytoskeletal proteins, it may play some role in the formation of LBs and LBHIs through the aberrant phosphorylation of the cytoskeletal elements in these inclusions.

Aged↗
PubMed1991

[Regulation of Ca2+/calmodulin-dependent protein kinase II in the cell systems in response to cellular stimuli].

Calcium ion (Ca2+) is considered to be involved in the regulation of numerous cellular processes. CaM kinase II is present at the highest concentration in the brain and is considered to be involved in the regulation and coordination of numerous cellular processes. CaM kinase II is activated by Ca2+/calmodulin and simultaneously undergoes autophosphorylation. It has not been determined whether the enzyme is activated in the cell systems in response to the increase in cytoplasmic Ca2+ concentration. We have studied CaM kinase II in several kinds of cells including the primary cultures of cerebellar granule cells and the cell lines of rat embryo fibroblast 3Y1 cells, neuroblastoma cells, PC12 cells and C6 glioma cells. The immunohistochemical analysis demonstrated the presence of CaM kinase II in all of the cells examined. Furthermore, the kinase in cerebellar granule cells was activated by the stimulation of the glutamic acid receptor. Autophosphorylation of CaM kinase II in 3Y1 cells was stimulated by the addition of growth factors. These results suggest that CaM kinase II undergoes activation and autophosphorylation in response to various stimuli to the cells and is regulated in the dynamic state.

Amino Acid Sequence↗
PubMed1991

Autophosphorylation of Ca2+/calmodulin-dependent protein kinase II: effects on interaction between enzyme and substrate.

Characteristics of the autophosphorylation of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) from the cytosol and in the postsynaptic densities (PSD) of rat brain were investigated. Several proteins were surveyed for their abilities to serve as a substrate for non-autophosphorylated and autophosphorylated CaM kinase IIs from the cytosol and PSD. The tested substrates were separated into two groups. Autophosphorylation of the kinase slightly decreased or did not change its activities towards substrates of the first group: myosin light chain of chicken gizzard, synapsin I, tau factor and microtubule-associated protein 2. In contrast, autophosphorylation of the enzyme increased its activities towards substrates of the second group: syntide-2, histone H1, calcineurin and myelin basic protein. The Ca2+/calmodulin-independent kinase activity increased by autophosphorylation with any of substrates tested. Similar results were obtained with the cytosolic and PSD CaM kinase II. Trifluoperazine and mastoparan, calmodulin binding antagonists, inhibited the activity of the non-autophosphorylated CaM kinase II, but had no effect or only a slight inhibitory effect on the activity of the autophosphorylated CaM kinase II, indicating that the autophosphorylated kinase has no requirement for calmodulin for Ca(2+)-dependent activity and/or a higher affinity for calmodulin The results suggest that the autophosphorylation of CaM kinase II is a subtle mechanism for regulating the interaction between the enzyme and substrate.

Animals↗
PubMed1991

[The respiratory function in children with collagen disease].

Respiratory function tests were performed on 60 children with collagen disease. Twenty-seven cases (45%) showed abnormalities in the respiratory function. These abnormalities were restrictive in 14 cases (52%), obstructive in 6 cases (22%), and mixed type in 7 cases (26%). Eight out of 14 SLE patients (57%) showed abnormalities of various types. Abnormalities were seen in 9 out of 25 JRA patients (36%) including 6 cases (67%) with restrictive type changes. Four out of 6 MCTD (67%) and 3 out of 9 DM (33%) patient showed functional abnormalities. Most of patients with these two types of collagen disease showed restrictive changes. Investigations performed by a research group of the Ministry of Health and Welfare showed the incidence of restrictive type changes (% VC less than 80) in adult patients of collagen disease to be in the following descending order: PM/DM greater than PSS greater than MCTD greater than SLE. Though small in number, our investigation revealed that a considerable proportion of MCTD and SLE patients showed restrictive changes in respiratory function. In evaluating the clinical course of the disease, it was thus considered to be important to follow up the progress of respiratory functions in children with collagen disease.

Adolescent↗
PubMed1991

[Studies on flomoxef in the perinatal period].

Pharmacokinetic, bacteriological and clinical studies on flomoxef (FMOX) in the perinatal period were carried out with the following summary of the results. Antibacterial effects of FMOX on the growth of methicillin-resistant Staphylococcus aureus (MRSA, MIC 400 micrograms/ml), methicillin-sensitive S. aureus (MSSA, MIC 0.78 microgram/ml), Escherichia coli (MIC 3.13 micrograms/ml and MIC 0.20 microgram/ml) in amniotic fluid were determined and it was found that the activity of FMOX was enhanced in the amniotic fluid. FMOX rapidly penetrated into tissues and sera of pregnant women upon intravenous injection and its maternal serum concentrations reached their peak levels shortly after administration. Placental penetration of FMOX to the fetus was good and, after single intravenous injection of 1 g, the concentrations of FMOX in the umbilical cord serum and amniotic fluid exceeded MICs against major causative organisms of perinatal infections. These results indicate that single intravenous injection of FMOX 1 g twice a day is effective for the treatment and prophylaxis of perinatal infections. Injection of FMOX for the treatment of 14 cases of puerperal infections showed excellent clinical effectiveness with 100% clinical effect and 81.8% bacteriological response. No side-effect was observed in any case. All of these results suggested clinical usefulness of FMOX in the perinatal period.

Adult↗
PubMed1990

Ca2+/calmodulin-dependent protein kinase II immunoreactivity in the rat hippocampus after forebrain ischemia.

The influence of transient forebrain ischemia on the temporal alteration of Ca2+/calmodulin-dependent kinase II (CaM kinase II) in the rat hippocampus was analysed by the immunohistochemical method using antigen-affinity purified polyclonal antibodies against CaM kinase II of rat brain. Six to twenty-four hours after ischemia, CA1 and CA3 pyramidal cells, and dentate granule cells lost CaM kinase II immunoreactivity in neuronal perikarya, although immunoreactivity in the dendritic fields was preserved. The recovery of immunoreactivity of the CA3 pyramidal cells and dentate granule cells was noted 3 days after recirculation. Seven days after ischemia, immunoreactivity in the CA1 subfield was greatly reduced. These results suggest that CaM kinase II molecules in the CA1 subfield are preferentially located on the CA1 pyramidal cells and that CaM kinase II plays a critical role in the reconstruction of neuronal cytoskeleton and neuronal networks damaged by ischemic insult.

Animals↗
PubMed1990

Longitudinal study of 94 symptomatic infants with perinatally acquired human immunodeficiency virus infection. Evidence for a bimodal expression of clinical and biological symptoms.

To better define the clinical and biological evolution of infants after vertical human immunodeficiency virus type 1 infection, we analyzed 94 consecutive infected patients followed up after their first clinical symptoms. The expression of clinical symptoms and biological abnormalities followed a bimodal distribution, some patients having an early and severe disease and the others having a slowly progressive one. One third of our patients suffered from early onset of opportunistic infection (OI). These patients had a significantly higher incidence of severe encephalopathy compared with patients without OI. The rate of survival at 3 years was 48% +/- 24%. In contrast, the patients without early OI or severe encephalopathy had a probability of survival at 3 years of 97% +/- 3%. This probability was not modified by the occurrence of bacterial infection or lymphoid interstitial pneumonitis. Lymphoid interstitial pneumonitis occurred at a mean age of 29 months, significantly later than OI or severe encephalopathy. Laboratory results at initial examination were correlated with clinical symptoms. Thus, when the number of CD4 lymphocytes was less than 500/mm3, children suffered more frequently from life-threatening symptoms (OI and severe encephalopathy): 15 of 22 vs 14 of 69. The same was true when the lymphocytes did not proliferate after antigenic stimulation, when anti-p18 and/or anti-p25 antibodies were absent in the serum, and when p24 antigen was detected in serum. Finally, severe encephalopathy was associated with low anti-human immunodeficiency virus cerebrospinal fluid antibody titer, whereas 88% of patients with moderate or no encephalopathy had signs of intrathecal anti-human immunodeficiency virus antibody synthesis. In conclusion, a subgroup of patients expressed very early signs of severe immunodeficiency and encephalopathy, whereas the majority of patients had a longer survival and less severe clinical symptoms during their first years of life than previously thought.

AIDS Dementia Complex↗
PubMed1990

Oscillatory behavior of a water/oil interface system in response to current-clamp and voltage-clamp stimulation.

Oscillatory behavior in response to current-clamp and voltage-clamp stimulation was examined on a water/oil/water system consisting of an aqueous solution of sodium oleate as surfactant, a solution of 2,2'-bipyridine in nitrobenzene and an aqueous solution of sodium chloride. Stable oscillation was observed only when the strength of the stimulation lay within a specific range of values.

2,2'-Dipyridyl↗
PubMed1990

Phosphorylation of P0 glycoprotein in peripheral nerve myelin.

The P0 protein in mammalian PNS myelin is known to undergo several posttranslational modifications, such as glycosylation, acylation, sulfation, and phosphorylation. Phosphorylation of purified P0 protein in vitro was studied comparatively using three enzymes, i.e., calcium/phospholipid-dependent protein kinase (protein kinase C), calcium/calmodulin-dependent protein kinase II (CaM kinase II), and the catalytic subunit of cyclic AMP-dependent protein kinase (A kinase). The phosphorylation of P0 protein by CaM kinase II was the greatest, followed by that by protein kinase C; phosphorylation by A kinase, however, was much lower. In order to identify phosphorylation sites, P0 protein was phosphorylated with [32P]ATP and each kinase and then digested with lysylendopeptidase. The resulting phosphopeptides were isolated by HPLC. Subsequent amino acid sequence analysis and comparison with the known sequence of P0 protein revealed that Ser181 and Ser204 were strongly phosphorylated by both protein kinase C and CaM kinase II. In addition, Ser214 was also phosphorylated by protein kinase C, but not by CaM kinase II. Because all of these sites are located in the cytoplasmic domain of P0 protein, phosphorylation may be important for maintenance of the major dense line of PNS myelin.

Amino Acids↗
PubMed1990

Regulation of Ca2+/calmodulin-dependent protein kinase II by brain gangliosides.

Purified rat brain Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II) is stimulated by brain gangliosides to a level of about 30% the activity obtained in the presence of Ca2+/calmodulin (CaM). Of the various gangliosides tested, GT1b was the most potent, giving half-maximal activation at 25 microM. Gangliosides GD1a and GM1 also gave activation, but asialo-GM1 was without effect. Activation was rapid and did not require calcium. The same gangliosides also stimulated the autophosphorylation of CaM-kinase II on serine residues, but did not produce the Ca2+-independent form of the kinase. Ganglioside stimulation of CaM-kinase II was also present in rat brain synaptic membrane fractions. Higher concentrations (125-250 microM) of GT1b, GD1a, and GM1 also inhibited CaM-kinase II activity. This inhibition appears to be substrate-directed, as the extent of inhibition is very dependent on the substrate used. The molecular mechanism of the stimulatory effect of gangliosides was further investigated using a synthetic peptide (CaMK 281-309), which contains the CaM-binding, inhibitory, and autophosphorylation domains of CaM-kinase II. Using purified brain CaM-kinase II in which these regulatory domains were removed by limited proteolysis. CaMK 281-309 strongly inhibited kinase activity (IC50 = 0.2 microM). GT1b completely reversed this inhibition, but did not stimulate phosphorylation of the peptide on threonine-286. These results demonstrate that GT1b can partially mimic the effects of Ca2+/CaM on native CaM-kinase II and on peptide CaMK 281-309.

Animals↗
PubMed1990

[Two cases of Yersinia pseudotuberculosis infection in children].

Yersinia pseudotuberculosis (Y. pseudotuberculosis) infection is an intestinal infectious disease comparable in importance as those with Campylobacter or Salmonella. Clinical symptoms of Y. pseudotuberculosis infection vary. In this report, we will describe the clinical symptoms and immunological conditions of the patients with Y. pseudotuberculosis infection, including 2 or our own cases. Case 1 was a 4 years old male infant admitted to the hospital with major complaints of fever, diarrhea, and vomiting. Kawasaki disease was the most suspected diagnosis from the clinical viewpoint. These symptoms improved by symptomatic treatments. Serum examination during hospitalisation revealed the infection of Y. pseudotuberculosis 4a. Case 2 was a 7 months old male baby with psychomotor developmental delay. The patient was admitted to hospital with major complaints of fever and eruptions. The patient was diagnosed to have a severe infectious disorder based on the clinical symptoms and findings of laboratory tests. Treatments with antibiotics improved the conditions. Serum examination during hospitalisation also revealed the Y. pseudotuberculosis 5a infection. Both of these cases showed decreased cellular immunity during the acute phase of the infection which was normalized with the improvement in clinical conditions. It was thus suggested that Y. pseudotuberculosis had a possibility to influence the cellular immunity of hosts transiently but significantly.

Age Factors↗
PubMed1990

[Studies on aztreonam in the perinatal period].

Pharmacokinetic, bacteriological and clinical studies on aztreonam (AZT) in the perinatal period were carried out with the following summary of the results. Antibacterial effects of AZT on bacterial growth of Escherichia coli (MIC 12.5 micrograms/ml) and Pseudomonas aeruginosa (MIC 50 micrograms/ml) in amniotic fluid were determined and it was found that the activity of AZT is enhanced in amniotic fluid. AZT rapidly penetrated into tissues and sera of pregnant women upon intravenous (i.v.) injection and its maternal serum concentrations reached their peak levels shortly after the injection. Placental penetration of AZT to the fetus was good and, after single i.v. injection of 1 g, the concentrations of AZT in the umbilical cord serum and amniotic fluid exceeded MICs against major Gram-negative bacilli. These results indicate that single i.v. injection of AZT 1 g twice a day is effective for the treatment and prophylaxis of perinatal infections. Injection of AZT for the treatment of puerperal infections showed excellent clinical effectiveness with 100% eradication of aerobic Gram-negative rods. No side-effect was observed in any case. All of the results suggested clinical usefulness of AZT in the perinatal period.

Adult↗
PubMed1990

Regulation of brain Ca2+/calmodulin-dependent protein kinase II.

CaM-kinase II is a multifunctional protein kinase highly enriched in neural tissues where it modulates a variety of Ca2(+)-dependent processes. A complex regulatory domain in the kinase within residues 281-309 contains an autoinhibitory sequence, a CaM-binding region, and sites of regulatory autophosphorylation. Autophosphorylation on Thr286 converts the kinase to a Ca2(+)-independent form which could prolong physiological systems controlled by this kinase in response to transient Ca2+ elevations. Such properties appear to exist in dynamic equilibrium in the isolated postsynaptic density and in cultured brain cells. These unique biochemical regulatory properties, coupled with an unusual high concentration in the postsynaptic density of excitatory synapses, makes CaM-kinase II an attractive candidate for involvement in synaptic plasticity.

Amino Acid Sequence↗
PubMed1989

Generation of the Ca2(+)-independent form of Ca2+/calmodulin-dependent protein kinase II in cerebellar granule cells.

Conditions that regulate the generation of the Ca2(+)-independent form of Ca2+/calmodulin-dependent protein kinase II (CaM-kinase II) in cultured rat cerebellar granule cells have been investigated. Under basal conditions, 4-5% of total CaM-kinase II activity, assayed in the presence of Ca2+/CaM, was the Ca2(+)-independent form active in the presence of EGTA. Depolarization with 56 mM K+ produced a transient increase to 9% Ca2+ independence within 15 s followed by a decline to 5-6% at 10 min. The divalent cation ionophore ionomycin elicited 10% Ca2+ independence, which remained elevated. Removal of Ca2+ from the Krebs-Ringer medium reduced basal Ca2+ independence to 1-2% and eliminated the elevation in response to K+ depolarization. Inclusion of 5 microM okadaic acid, a protein phosphatase inhibitor, in the incubation medium potentiated the levels of Ca2(+)-independent activity of CaM-kinase II. Additional studies in granule cell extracts indicated that there were both okadiac acid-sensitive and -insensitive protein phosphatases involved in the reversal of the Ca2+ independence of CaM-kinase II. Phosphopeptide mapping of the CNBr-cleaved 32P-labeled 58-60-kDa subunit of CaM-kinase II revealed that under basal conditions, the kinase contained phosphate in many sites. Conditions that promoted formation of the Ca2(+)-independent form of the kinase increased the 32P incorporation into multiple sites of the kinase. However, there was a good temporal correlation between 32P incorporation into CNBr peptide 1, which contains Thr-287, and generation of the Ca2(+)-independent kinase activity. These results indicate that formation of the Ca2(+)-independent species of CaM-kinase II is dynamically regulated in cerebellar granule cells by Ca2(+)-mobilizing agents and by protein phosphatase activity and is correlated with autophosphorylation of Thr-287.

Animals↗