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Biomedical subjects

K Fukunaga

Publications and source records attributed to K Fukunaga.

At least 235 records · Page 13Linked to original sources
PubMed1989

Differential effects of alpha-, beta- and gamma-cyclodextrins on human erythrocytes.

Alpha-, beta- and gamma-cyclodextrins are cyclic hexamers, heptamers, and octamers of glucose, respectively, and thus are hydrophilic; nevertheless, they have the ability to solubilize lipids through the formation of molecular inclusion complexes. The volume of lipophilic space involved in the solubilization process increases with the number of glucose units in the cyclodextrin molecule and, consequently, cyclodextrins were found to have different effects on human erythrocytes: (a) in the induction of shape change from discocyte to spherocyte the potency was observed to be alpha greater than gamma, but with beta-cyclodextrin hemolysis occurred before the change was complete; (b) in the increase of fluorescence intensity of 1-anilinonaphthalene-8-sulfonate in cyclodextrin-pretreated membranes, the observed potency was beta much greater than gamma greater than alpha; (c) in the release of potassium and hemoglobin, the potency was beta greater than alpha greater than gamma. The potencies of cyclodextrin for solubilizing various components of erythrocytes were alpha greater than beta much greater than gamma for phospholipids, beta much greater than gamma greater than alpha for cholesterol and beta much greater than gamma greater than alpha for proteins. The solubilization potencies were derived from concentration/final-effect curves. The above processes occurred without entry of solubilizer into the membrane, since (a) beta-[14C]cyclodextrin did not bind to erythrocytes and (b) cyclodextrins did not enter the cholesterol monolayer. A study of the [3H]cholesterol in erythrocytes indicated that beta-cyclodextrin extracted this lipid from membrane into a new compartment located in the aqueous phase which could equilibrate rapidly with additional erythrocytes. Therefore, the effects of cyclodextrins differ from those of detergents which first incorporate themselves into membranes then extract membrane components into supramolecular micelles.

Cyclodextrins↗
PubMed1989

Alkylation of cyclomalto-oligosaccharides (cyclodextrins) with dialkyl sulfate-barium hydroxide: heterogeneity of products and the marked effect of the size of the macrocycle.

The alkylation of cyclomalto-oligosaccharides (cyclodextrins, CDs) with dialkyl sulfate-barium hydroxide has been claimed to yield 2,6-di-O-alkyl derivatives. Re-investigation by plasma desorption-m.s. of the products of laboratory methylation of alpha CD, beta CD, or gamma CD and ethylation of beta CD and several commercial preparations revealed them to be mixtures with broad and roughly symmetrical distributions of the degree of substitution. Recrystallization separated the components only partially. Analysis of the product of methylation of a mixture of CDs established the order of reactivity gamma much greater than alpha greater than or equal to beta. The reactivity of gamma CD thus resembles that of amylose.

Alkylation↗
PubMed1989

[Prognostic factors in HIV seropositive children by materno-fetal transmission].

Ninety-four cases with HIV seropositive children who were found in the Hospital Necker Enfants Malades in France from April 1983 till September 1988 due to materno-fetal transmission were surveyed for immunological studies as well as the relationship between clinical symptoms and the prognosis. Lymphoadenopathy and/or hepatosplenomegaly were found in 98% of the total cases. Opportunistic infections, severe neurological problems and LIP were found in 28%, 16% and 15%, respectively. At the first laboratory examination, cases showing under 500/mm3 of OKT4 lymphocytes and with negative antigen-induced proliferative responses were observed in 24% and 44% of the cases, respectively. Negative serological profiles of antibodies to P18 and P25 HIV antigens appeared to show low values of OKT4 lymphocytes and abnormal responses to antigens. The survival cases with these findings were minimum. These data indicate that it is very much worth, while to estimate the degree of immunological deficiency and infectious complications.

CD4-Positive T-Lymphocytes↗
PubMed1989

[Pharmacokinetic studies on cefsulodin in perinatal period].

Pharmacokinetic studies on cefsulodin (CFS) were carried out in perinatal mothers and infants. The results obtained are summarized as follows. 1. CFS was promptly absorbed upon intravenous drip infusion in pregnant women, producing dose-related peak serum levels. Placental transference to the fetus occurred quickly and at high levels. Upon intravenous drip infusion of 1-2 g of CFS, drug concentration of the cord blood and amniotic fluid exceeded MICs of clinically isolated strains of Pseudomonas aeruginosa. These levels in cord blood ranged 3.3-16.9 micrograms/ml upon 1 g intravenous drip infusion and 0.8-21.6 micrograms/ml upon 2 g intravenous drip infusion, and in amniotic fluid they were 1.3-15.6 micrograms/ml upon 1 g administration and 5.5-17.9 micrograms/ml upon 2 g administration. The drug was transferred into newborn infant through placenta, showing no tendency to accumulate. According to the above results, it appears possible to successfully prevent or treat perinatal infections through administration of the dose of 1-2 g twice daily. 2. Moreover, newborn infants delivered from mothers receiving CFS administration showed no laboratory test abnormalities. 3. The penetration of CFS into mother's milk occurred at low levels, and the transference from milk to newborn infants appeared to occur at even low levels. The above results have demonstrated that CFS is a clinically useful antibiotic for prophylaxis and treatment of perinatal Pseudomonas infections.

Cefsulodin↗
PubMed1989

[Current state of the treatment of congenital biliary atresia].

Current state of the treatment of biliary atresia was studied concerning following factors based on our experience of 240 patients during 1966 to 1988, particularly 103 patients who received Kasai operation with Suruga II modification. 1. Operative results: Overall and Suruga II. 2. Predictable factors of the prognosis at the first radical operation, especially, among the age, the hepatic fibrosis and the size of ductuli at porta hepatis. 3. Technical refinement of Kasai operation, especially concerning the exposure of portal area and the anastomosis. 4. Our recent device of modified Kasai operation, that is, hepatic portoduodenostomy with interposition of ileocecoappendix. 5. Rehepatic portoenterostomy in case of poor postoperative bile flow. From our experiences, Kasai operation is indicated to the patients who have mild or moderate liver fibrosis and good sized ductuli at porta hepatis, but not to the patients who have advanced liver fibrosis and extremely poor ductuli. In such circumstance, liver transplantation should be considered. Rehepatic portoenterostomy is only indicated to the patients who have a good bile flow after the initial Kasai operation but not to the patients who have no bile flow.

Biliary Atresia↗
PubMed1989

[Pharmacokinetic and clinical studies on cefodizime in obstetrics and gynecology].

Cefodizime (CDZM), a new cephem antibiotic, was studied in terms of its pharmacokinetics and clinical efficacy in the field of obstetrics and gynecology, and the results are summarized as follows: Concentrations of CDZM in serum and genital tissues following 1 g drip infusion (30 min.) were determined and good penetration of CDZM into tissues was recognized. The maximum level in uterine arterial serum was 56.25 micrograms/ml and maximum tissue levels ranged 23.56-40.64 micrograms/g which were above its MIC80's for main pathogenic organisms. Peak concentrations of CDZM in pelvic dead space exudates following 1 g intravenous bolus injection or drip infusion ranged 6.25-6.52 micrograms/ml. The clinical efficacy of CDZM in 17 cases of obstetrical and gynecological infections was investigated using a dose of 1-3 g daily. The clinical efficacy rate was 88.2% (15/17 cases). Bacteriologically, the eradication rate was 83.3%. No side effects or abnormal laboratory test values were observed.

Adult↗
PubMed1989

[Fundamental and clinical studies on cefmenoxime in perinatal period].

Pharmacokinetic studies and clinical evaluations of cefmenoxime (CMX) were carried out in perinatal mothers and infants. The following results obtained are summarized as follows. 1. CMX was promptly absorbed upon intravenous injection in pregnant women, reached dose-related peak serum level shortly after administration. Placental penetration into the fetus occurred quickly and at high levels. After intravenous injection of 1 g of CMX, drug concentrations in the cord blood and amniotic fluid exceeded MICs of main pathogenic organisms. The drug transferred into newborn infants were followed by measuring serum level of the newborn. These levels were related to levels of umbilical cord blood and the drug was eliminated gradually from the newborn without accumulation. According to the above results, it appears possible to successfully prevent or treat perinatal infections, through administration of the dose of 1 g twice daily. 2. Clinically, CMX was effective in the treatment of perinatal infections and prophylaxis of intra-uterine amniotic infections without any severe side effect. 3. Moreover, newborn infants delivered from mothers receiving CMX treatment were without abnormalities in laboratory test results. 4. The penetration of CMX into mother's milk was hardly observed and the transference from milk to newborn infants appeared to be occur only at very low levels. The above results have demonstrated that CMX is a clinically useful antibiotic for prophylaxis and treatment of perinatal infections.

Bacterial Infections↗
PubMed1988

Serum and growth factors rapidly elicit phosphorylation of the Ca2+/calmodulin-dependent protein kinase II in intact quiescent rat 3Y1 cells.

A 50-kDa protein was recognized in rat embryo fibroblast 3Y1 cells with an affinity-purified antibody against rat brain Ca2+/calmodulin-dependent protein kinase II (CaM kinase II). When the cytosolic extract from quiescent 3Y1 cells was immunoprecipitated with the antibody, the 50-kDa protein in the immunoprecipitate became phosphorylated in a Ca2+- and calmodulin-dependent manner following exposure to [gamma-32P]ATP. Moreover, the reaction proceeded through an intramolecular mechanism. These results suggest that the 50-kDa protein is a subunit of CaM kinase II in rat 3Y1 cells. The addition of 10% fetal calf serum to quiescent 3Y1 cells caused a rapid increase in the phosphorylation of the 50-kDa protein, which was immunoprecipitated with the affinity-purified anti-CaM kinase II antibody. The phosphorylation of CaM kinase II was detected as early as 20 s after the addition of serum, reached the maximal level at 2 min, and decreased to the basal level within 60 min. Platelet-derived growth factor and epidermal growth factor also elicited the phosphorylation of the 50-kDa protein in quiescent 3Y1 cells, while neither insulin nor 12-O-tetradecanoylphorbol-13-acetate did. Calcium ionophores, A23187 and ionomycin, also caused the phosphorylation of the protein in 3Y1 cells. Moreover, phosphopeptide mappings of the phosphorylated 50-kDa subunit generated in response to serum, EGF, and A23187 yielded patterns similar to that generated from the immunoprecipitated 50-kDa subunit phosphorylated in vitro. Phosphoamino acid analysis of the phosphorylated subunit demonstrated that serine residue was the major amino acid labeled under any condition. These results suggest that CaM kinase II undergoes phosphorylation in response to various stimuli that can increase the free Ca2+ concentration in the cytoplasm of quiescent fibroblast cells and therefore probably mediates at least some of the biological actions of growth factors.

Animals↗
PubMed1988

2-Hydroxypropyldigitonin: synthesis and properties of preparations differing in degree of substitution.

Reaction of propylene oxide with digitonin in strong aqueous alkali yielded water soluble, nontoxic solubilizers of drugs and hormones, the molecular composition of which could be fully deduced from plasma desorption mass spectrometry data. Preparations with average degrees of substitution ranging from 0.7 to 4.5 were investigated, and all the distributions of degrees of substitution observed were relatively narrow and symmetrical; thus, the reactivity of primary and secondary hydroxyls of saponin and of its conversion products had to be quite similar. The effects of the average degree of substitution of 2-hydroxypropyldigitonins on the formation of micelles and on the solubilization of four drugs into aqueous solutions were found to be minor. On the other hand, the ability to hemolyze erythrocytes decreased sharply with an increasing average degree of substitution.

Animals↗
PubMed1988

Identification of the multifunctional calmodulin-dependent protein kinase in the cytosol, sarcoplasmic reticulum, and sarcolemma of rabbit skeletal muscle.

A multifunctional calmodulin-dependent protein kinase (calmodulin kinase) was purified from the cytosol of rabbit skeletal muscle as a subunit of 58 kDa. A 58-kDa protein in sarcoplasmic reticulum (SR) and sarcolemma (SL) of rabbit skeletal muscle was endogenously phosphorylated in a calmodulin-dependent manner. The 58-kDa protein in SR and SL was considered to be identical to the subunit of cytosol calmodulin kinase on the basis of immunoreactivity, calmodulin binding, and autophosphorylation studies and on the patterns of protease-treated phosphopeptides. Calmodulin kinase showed broad substrate specificity and phosphorylated troponins I and T.

Animals↗
PubMed1988

Amorphous water-soluble cyclodextrin derivatives: 2-hydroxyethyl, 3-hydroxypropyl, 2-hydroxyisobutyl, and carboxamidomethyl derivatives of beta-cyclodextrin.

The pharmaceutical usefulness of natural, crystalline cyclodextrins can be improved by chemical conversions into water-soluble, amorphous mixtures of their derivatives. Reaction of beta-cyclodextrin with 2-chloroethanol, 3-chloropropanol, isobutylene oxide, or iodoacetamide yielded the title compounds. Distributions of the substitution degree were close to symmetrical and relatively narrow. The average substitution degrees increased with the amount of alkylating reagent used in the preparation. The number of components (half-width of distribution) increased with increasing average substitution degree. Further, distributions of the substitution degree were measured in glucose derivatives after hydrolysis of 2-hydroxyethyl, 2-hydroxypropyl, and 2-hydroxyisobutyl-beta-cyclodextrin. The results show an uneven distribution of substituents around the cyclodextrins, suggesting that growth of oligoglycol side chains and/or clustering of substituents on one glucose residue occurs.

Chemical Phenomena↗
PubMed1988

Dephosphorylation of microtubule proteins by brain protein phosphatases 1 and 2A, and its effect on microtubule assembly.

Protein phosphatase C was purified 140-fold from bovine brain with 8% yield using histone H1 phosphorylated by the catalytic subunit of cyclic AMP-dependent protein kinase (cyclic AMP-kinase). Brain protein phosphatase C was considered to consist of 10 and 90%, respectively, of the catalytic subunits of protein phosphatases 1 and 2A on the basis of the effects of ATP and inhibitor-2. Protein phosphatase C dephosphorylated microtubule-associated protein 2 (MAP2), tau factor, and tubulin phosphorylated by a multifunctional Ca2+/calmodulin-dependent protein kinase (calmodulin-kinase) and the catalytic subunit of cyclic AMP-kinase. The properties of dephosphorylation of MAP2, tau factor, and tubulin were compared. The Km values were in the ranges of 1.6-2.7 microM for MAP2 and tau factor. The Km value for tubulin decreased from 25 to 10-12.5 microM in the presence of 1.0 mM Mn2+. No difference in kinetic properties of dephosphorylation was observed between the substrates phosphorylated by the two kinases. Protein phosphatase C did not dephosphorylate the native tubulin, but universally dephosphorylated tubulin phosphorylated by the two kinases. The holoenzyme of protein phosphatase 2A from porcine brain could also dephosphorylate MAP2, tau factor, and tubulin phosphorylated by the two kinases. The phosphorylation of MAP2 and tau factor by calmodulin-kinase separately induced the inhibition of microtubule assembly, and the dephosphorylation by protein phosphatase C removed its inhibitory effect. These data suggest that brain protein phosphatases 1 and 2A are involved in the switch-off mechanism of both Ca2+/calmodulin-dependent and cyclic AMP-dependent regulation of microtubule formation.

Animals↗
PubMed1988

Immunohistochemical localization of Ca2+/calmodulin-dependent protein kinase II in rat brain and various tissues.

Polyclonal antibodies against Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) of rat brain were prepared by immunizing rabbits and then purified by antigen-affinity column. The antibodies which recognized both subunits of the enzyme with Mrs 49K and 60K were used for the study on the distribution of CaM kinase II in formalin-fixed, paraffin-embedded tissues. In the brain, a light-microscopic study demonstrated strong immunoreactivity in neuronal somata and dendrites and weak immunoreactivity in nuclei. The densely stained regions included cerebral cortex, hippocampal formation, striatum, substantia nigra, and cerebellar cortex. In substantia nigra, neurites were stained, but not neuronal somata. Electron microscopy revealed that the immunoreactive product was highly concentrated at the postsynaptic densities. In addition to neurons, weak immunoreactivity was also demonstrated in glial cells, such as astrocytes and ependymal cells of ventricles and epithelial cells of choroid plexus. In other tissues, strong immunoreactivity was observed in the islet of pancreas and moderate immunoreactivity in skeletal muscle and kidney tubules. Immunoreactivity was demonstrated in all of the tissues tested. The results suggest that CaM kinase II is widely distributed in the tissues.

Animals↗
PubMed1988

Purification of the multifunctional calmodulin-dependent protein kinases from lung and liver, and the comparison to the brain enzyme.

We purified the multifunctional calmodulin-dependent protein kinases (calmodulin-kinase) from rat lung and rabbit liver, and compared the properties of this enzyme with those of the rat brain enzyme. The lung and liver enzymes had molecular weights (Mr's) of 530,000 and 330,000 with main subunits of 52 and 51 kDa, respectively. Although the lung and liver enzymes cross-reacted with antibodies to the brain enzyme, the immunoreactivity of the lung enzyme was weaker. The substrate specificity of the three enzymes showed differences in the relative reaction rate of phosphorylation. The patterns of phosphopeptides of the lung and liver enzymes were similar to each other and only partly common to that of the 60-kDa subunit of the brain enzyme.

Animals↗
PubMed1988

[Studies of ceftizoxime in perinatal period].

Bacteriological studies and clinical evaluations of ceftizoxime (CZX) in perinatal period were carried out, and results are summarised as follows: Antibacterial activities of CZX in amniotic fluid were determined using the broth dilution method, and bactericidal effect on Streptococcus agalactiae, Staphylococcus aureus and Escherichia coli were demonstrated. The bactericidal effect of CZX increased in amniotic fluid and remarkable increases of activities against resistant strains were demonstrated. The penetration of CZX into mother's milk was low, and it was speculated that the drug transfer to the newborn through breast feeding was very little. Clinically, CZX was effective in the treatment of perinatal infections without any side effect. The above results has demonstrated that CZX is a clinically useful antibiotic for the prophylaxis and the treatment of perinatal infections.

Adult↗