[Nutritional management in chronic hemodialysis].
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Humans↗
Biomedical subjects
Y Maeda
Publications and source records attributed to Y Maeda.
Comparison of hemodynamic effects and plasma cyclic guanosine monophosphate of nicorandil and nitroglycerin in patients with congestive heart failure.
Hemodynamic tolerance has been observed within several hours of continuous infusion of nitroglycerin (NTG). We examined the hemodynamic parameters as well as femoral arterial and venous cyclic guanosine monophosphate (cGMP) concentrations during intravenous infusion of NTG or nicorandil, a nitrate and potassium channel opener, in patients with congestive heart failure. Doses of NTG or nicorandil were titrated to achieve a > or = 25% reduction in pulmonary capillary wedge pressure (PCWP) within 1 hour, and the infusion was maintained at a constant rate for 24 hours. The reduction in PCWP and mean arterial blood pressure was identical after a 1-hour infusion of either NTG or nicorandil. In the NTG group, PCWP and mean blood pressure were not significantly different from the baseline value at 12 hours, but in the nicorandil group PCWP and mean blood pressure remained significantly lower than the preinfusion value for 24 hours. The cGMP production with NTG (assessed by the difference between the plasma arterial and venous cGMP level) paralleled the changes in PCWP, suggesting that the plasma arteriovenous cGMP difference is a biochemical indicator of nitrate tolerance. Although the sustained decrease in PCWP was observed in the nicorandil group, cGMP production with nicorandil was also attenuated at 24 hours of continuous infusion. These findings suggest that the absence of the hemodynamic tolerance of nicorandil, a nitrate and potassium channel opener, is likely due to its action as a potassium channel opener, and not to its nitrate activity.
Adult↗
Synthesis, absolute configuration, and enantioselectivity of antiretroviral effect of (R)-(-)- and (S)-(+)-cytallene. Lipase-catalyzed enantioselective acylations of (+/-)-N4-acylcytallenes.
Enantioselectivity of acylations of (+/-)-cytallene (1b), (+/-)-N4-acetylcytallene (11a), (+/-)-N4-benzoylcytallene (11b), and (+/-)-N4-(9-fluorenylmethoxycarbonyl)cytallene (11c) using vinyl butyrate or acetate catalyzed by lipases in organic solvents was investigated. Reactions with 1b, 11a, and adenallene (1a) did not display a high enantioselectivity but all resulted in a predominant acylation of the (-)-enantiomers. Application of the Lowe-Brewster rule led to a tentative assignment of the R-configuration to all acylated products. Studies of the time course of acylation of (+/-)-N4-benzoylcytallene (11b) in chloroform, tetrahydrofuran (THF), tetrahydropyran (THP), tetrahydrothiophene (THT), and dioxane with lipase PS30 and/or AK showed that the reaction in THF catalyzed by lipase AK was the most promising for resolution of 11b. Indeed, a large-scale acylation afforded, after separation and deprotection of intermediates 3e and 10d, (+)- and (-)-cytallene (3c and 2b) in high yield and enantioselectivity. Acylation of 11c in THF led also to formation of 3c and 2b in high enantioselectivity. Single crystal X-ray diffraction established the S-configuration of (+)-cytallene (3c), thus confirming the assignment made on the basis of Lowe-Brewster rule. An improved large-scale synthesis of (+/-)-cytallene (1b) is also described. The R-enantiomer 2b inhibited the replication of a primary human immunodeficiency virus (HIV-1) isolate in phytohemagglutinin-activated peripheral blood mononuclear cells (PHA-PBM) with IC50 0.4 and IC90 1.7 microM. (+/-)-Cytallene (1b) exhibited IC50 0.8 and IC90 3.4 microM. Both compounds completely suppressed replication of HIV-1 at 10 microM with no detectable cytotoxicity. The S-enantiomer (3c) was inactive.
Acylation↗
Neuronal mechanism of the inhibitory effect of calcitonin on N-methyl-D-aspartate-induced aversive behavior.
To elucidate the mechanism of antinociceptive effects of calcitonin, we investigated whether receptor antagonists for various neurotransmitter receptors alter the inhibitory effect of calcitonin on intrathecally injected N-methyl-D-aspartate-induced aversive behavior in mice. Neither naloxone, an opioid receptor antagonist, phentolamine and benextramine, alpha-adrenoceptor antagonists, nor ritanserin, a 5-HT2A receptor antagonist, inhibited the calcitonin-induced anti-aversive effects. Pindolol and (--)-propranolol, non-selective antagonists of beta-adrenoceptors and 5-HT1 receptors, 1-(2-methoxyphenyl)-4-[4-(2-phethalimido) butyl]-piperazine hydrobromide (NAN-190), a 5-HT1A receptor antagonist, 3-tropanyl-3,5-dichlorobenzoate (MDL72222) and metoclopramide, 5-HT3 receptor antagonists, significantly inhibited the calcitonin-induced anti-aversive effects. (--)-Bicuculline, a GABAA receptor antagonist, phaclofen and 5-aminovaleric acid, GABAB receptor antagonists, also attenuated the calcitonin-induced anti-aversive effects. These results suggest that beta-adrenoceptor, 5-HT1A, 5-HT3, GABAA and GABAB receptors, but not alpha-adrenoceptor, opioid nor 5-HT2A receptors, are involved in the inhibitory effect of calcitonin on intrathecally injected N-methyl-D-aspartate-induced aversive behavior in mice.
Adrenergic alpha-Antagonists↗
Sexual transmission of human T-lymphotropic virus type I among female prostitutes and among patients with sexually transmitted diseases in Fukuoka, Kyushu, Japan.
The authors investigated the prevalence of antibody to human T-lymphotropic virus type I (anti-HTLV-I) in 409 female prostitutes, 446 patients with an episode of sexually transmitted diseases, and 17,345 control blood donors. All subjects were Japanese and all studies were done in Fukuoka, Kyushu, Japan, in 1989. The prevalence of anti-HTLV-I was significantly higher in the prostitutes (5.1%, p < 0.001), in the male patients (2.8%, p < 0.05), and in the female patients (5.7%, p < 0.05) than in the controls (males 1.4%, females 2.2%). Prevalence of anti-HTLV-I in the prostitutes increased with the number of years spent in prostitution, but the increase was not statistically significant. Among the subjects with sexually transmitted diseases, female prostitutes with syphilis, male patients with non-gonococcal urethritis, female patients with syphilis, and female patients with gonorrhea had a significantly higher prevalence of anti-HTLV-I than did the controls. A longitudinal study was done on the 168 prostitutes. Two (1.3%) of the 158 initially seronegative subjects seroconverted over the period of 2 years. These data suggest that the risk of male-to-female transmission of HTLV-I through sexual contact is high among high risk groups in Japan, and they support the possibility of female-to-male transmission of HTLV-I.
Adolescent↗
Visible photoluminescence from nanocrystallite Ge embedded in a glassy SiO2 matrix: Evidence in support of the quantum-confinement mechanism.
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Journal Article↗
Involvement of cyanide-resistant respiration in cell-type proportioning during Dictyostelium development.
Involvement of cyanide (CN)-resistant respiration in cell-type proportioning was analyzed using the developmental system of Dictyostelium discoideum. When migrating slugs were vitally stained with rhodamine 123, which is known to stain actively respirating mitochondria coupled with an elevated electronic potential of the inner membrane, the posterior prespore region was stained more strongly than the anterior prestalk region. Application of benzohydroxamic acid (BHAM) and propyl gallate, specific inhibitors of CN-resistant respiration, to starved Dictyostelium cells induced formation of unique cell masses, in which almost all of the cells differentiated into stalk-like cells with a large vacuole and thick cell wall. BHAM was also found to enhance the expressions of prestalk-specific genes such as ecmA and ecmB in the unique cell mass in a position-dependent manner. In contrast, the expression of a prespore-specific gene, Dp87, was almost completely inhibited by BHAM. Taken together these results strongly suggest the involvement of CN-resistant respiration in the proportion regulation of cell types differentiating during the Dictyostelium development.
Animals↗
Signal transduction via Fc receptors; involvement of tyrosine kinase and redox regulation by ADF.
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Amino Acid Sequence↗
Rolipram, a selective c-AMP phosphodiesterase inhibitor suppresses oro-facial dyskinetic movements in rats.
Since striatal dopamine D2 receptor supersensitivity in the etiology of tardive dyskinesia has been suggested and dopamine D2 receptors are known to inhibit adenylate cyclase activity resulting in a decrease of cyclic adenosine 3',5'-monophosphate (cAMP) levels, we hypothesized that an increase in cAMP levels ameliorates the condition. In the present study, 21-day haloperidol treatment (1.5 mg/kg I.P.) in rats resulted in an increase in striatal [3H]-spiperone (D2) binding whereas [3H] SCH23390 (D1) binding was unaltered. This haloperidol treatment also induced a significantly increase in the frequency of involuntary chewing movements and tongue protrusions, which are considered as a model of tardive dyskinesia. These dyskinetic movements were suppressed by administration of rolipram (0.5 and 1.0 mg/kg I.P.), an inhibitor of the cAMP phosphodiesterase type IV. The present results suggest that selective cAMP phosphodiesterase type IV inhibitors could be putative therapeutic drugs for tardive dyskinesia.
3',5'-Cyclic-AMP Phosphodiesterases↗
Donor card registration system in Japan: an obstacle to procuring kidneys for transplantation.
Donor cards are a simple and effective way to give a consent to organ donation in cases of unexpected death. In Japan the prevalence of donor cards is low (0.4%) compared to the United States (24.6%), although about 50% of Japanese people are reported to be willing to donate their organs after death, a figure equivalent to the United States. We hypothesized that the donor card registration system can explain the low prevalence, and an introduction of a free delivery system will increase the prevalence. From April 1992 to April 1993, 402 high school students and 3391 workers in the Tokyo metropolitan area were requested to answer questionnaires; all the questionnaires were returned. Few respondents (15.5%) knew the way in which to be registered as a donor card holder. If donor cards were delivered freely and registration to carry a donor card was not required, 48.8% replied that they would be willing to carry donor cards. The most commonly cited reason for not carrying a donor card was 'I had no opportunity to get a donor card'. This study indicates that the introduction of free delivery of donor cards will increase the prevalence dramatically if a sufficient number of opportunities are offered. We recommend that a free delivery system should be introduced in order to increase the prevalence and secure the will of the deceased rather than the will of the family.
Adolescent↗
The effects of a selective cAMP phosphodiesterase inhibitor, rolipram, on methamphetamine-induced behavior.
The effects of rolipram, a selective cAMP phosphodiesterase inhibitor, on locomotor activity, rearing, and stereotyped behavior (sniffing, repetitive head movements) induced by methamphetamine (MAP) over 1 hour were investigated in rats. Coadministration of rolipram (4 mg/kg IP) significantly attenuated the responses of locomotor activity, rearing and repetitive head movements to MAP (2,4 or 8 mg/kg IP). Rolipram (0.5, 1, 2, or 4 mg/kg IP) dose-dependently inhibited locomotor hyperactivity and rearing induced by 4 mg/kg of MAP. The rearing was completely inhibited by 4 mg/kg of rolipram, whereas the maximal inhibition of the locomotor hyperactivity was about 50%. However, rolipram did not alter MAP-induced sniffing and repetitive head movements. These results indicate that there is heterogeneity in the response of MAP-induced behavior to rolipram, suggesting that MAP-induced behavioral alteration may be partly regulated by cAMP levels in the brain.
Animals↗
Interleukin 4 enhances ganglioside GD3 expression on the human fibroblast cell line WI-38.
Human fibroblast cell line WI-38 cultured in vitro was treated with a human recombinant IL-4 at concentrations of 1 to 100 U/ml to examine the alteration of glycosphingolipid (GSL) expression of the cells. Neutral GSL of non-treated WI-38 cells consisted of CMH (GlcCer), CDH, CTH, and Gb4Cer; CMH and CTH were the major components. The acidic GSL were composed of GM3 as the predominant component and other minor gangliosides including GD3. The neutral GSLs did not change in profile during the treatment with IL-4, while the acidic GSLs showed a prominent change, an increase of GD3 content. The increase of GD3 was detectable with IL-4 concentrations over 1 U/ml, and reached a plateau at 10 U/ml, where the amount of GD3 was almost equal to that of GM3. The GD3 increase occurred at 24 h after the IL-4 treatment, and lasted for at least 96 h, as long as IL-4 remained present in the culture media. The GD3 synthase (sialyltransferase) level was found to be increased in an IL-4 dose-dependent manner. IL-4 did not influence the growth or morphological appearance of WI-38 cells. The results demonstrate a novel biological effect of IL-4, modulating GSL in non-hematopoietic cells.
Cell Line↗
Effective renaturation of reduced lysozyme by gentle removal of urea.
To increase the folding yield of concentrated reduced lysozyme, we developed a renaturation method by means of dialysis from concentrated urea with redox agents. After lysozyme was incubated in the reducing buffer (8 M urea solution) with oxidized glutathione, renaturation of reduced lysozyme was started by dialysis against the dialyzing buffer containing 8 M urea with redox agents. The urea concentration of the dialyzing bottle was gradually diluted with dialyzing buffer without urea at a flow rate of 0.1 ml/min by high pressure pump. Using this systematic dialysis, a concentration as high as 5 mg/ml of reduced lysozyme could be renaturated in 80% yield, while the folding yield was < 5% even at a concentration of 1 mg/ml using a conventional rapid dilution method [Goldberg et al. (1991) Biochemistry, 30, 2790-2797]. Therefore, it was concluded that gentle removal of urea from denatured proteins, dissolved in concentrated urea solution, by means of dialysis should be useful to renature denatured proteins effectively.
Buffers↗
Human parvovirus B19 infection in blood donors.
Using an immunodiffusion assay, we tested all of the blood units donated at the Fukuoka Red Cross Blood Center from June 1991 to July 1994 for B19 antigen. Over this 3-year trial period, we detected 16 viremic cases out of approximately 560,000 blood donors. Interestingly, most of the viremic donors (15 out of 16) were detected between February 1992 and January 1993, which coincided with a local erythema infectiosum epidemic in the Fukuoka area (December 1991 to August 1992). In particular, we detected 4 cases of viremia in March 1992, which was the peak of the erythema infectiosum epidemic. The incidence of B19 viremia in this peak period was approximately 1/4,000. The viremic donors ranged in age from 17 to 45 years, and most (11/16) were between 31 and 39 years old. By ELISA, using virus particles purified from viremic donor plasma as antigen, we analyzed the prevalence of B19-specific antibody among blood donors. The antibody-positive rate was approximately 40% in donors 16-30 years old, gradually increased in middle age, and reached a peak of 92% in donors more than 61 years old.
Adolescent↗
Kawasaki disease and human parvovirus B19 antibody: role of immunoglobulin therapy.
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Antibodies, Viral↗
Modification of alpha-chymotrypsin using a water-soluble photo-Fenton reagent.
Modification of an enzyme, alpha-chymotrypsin, was examined by using a water-soluble photo-Fenton reagent. By photoirradiation of the enzyme with the reagent, which can occupy a binding site of the enzyme, a tryptophan residue in the vicinity of the active site was oxidized to N-formylkynurenine. Concurrently, the catalytic properties of the enzyme were largely changed: the Km was increased and the kcat was decreased. The decrease in kcat for a specific amide substrate was the most significant among the esters and amides examined. The water-soluble photo-Fenton reagent would be useful to chemically modify relatively limited regions in biomolecules.
Animals↗
Cerebral magnetic resonance angiographic findings in severe preeclampsia.
OBJECTIVE: The purpose of our study was to investigate the cerebral pathophysiology of severe preeclampsia using the noninvasive method of magnetic resonance angiography. STUDY DESIGN: We studied cerebral magnetic resonance angiography findings in 9 severely preeclamptic patients. RESULTS: Magnetic resonance angiographies were abnormal on first scanning within 48 h postpartum, followed by normal findings on repeat scanning during the 1st postpartum month in 6 patients. The most common abnormality was vascular narrowing of anterior cerebral artery and basilar artery. Three of these 6 patients complained of headaches and/or visual disturbances. CONCLUSION: This study shows that cerebral artery vasospasm is seen in some severe preeclamptic patients.
Adult↗
Increased mitogenic response to heparin-binding epidermal growth factor-like growth factor in vascular smooth muscle cells of diabetic rats.
We investigated the mitogenic effects of heparin-binding epidermal growth factor-like growth factor (HB-EGF) in vascular smooth muscle cells (SMCs) obtained from rats with streptozotocin (STZ)-induced diabetes and evaluated the role of heparan sulfate proteoglycan (HSPG) in inducing these effects. HB-EGF significantly increased DNA synthesis in the SMCs of diabetic rats (STZ-SMCs) compared with control rats (control SMCs). However, the mitogenic effects of EGF, which shares EGF receptors with HB-EGF, and basic fibroblast growth factor, another heparin-binding growth factor, were similar in STZ-SMCs and control SMCs. The mitogenic response to HB-EGF in SMCs of insulin-treated diabetic rats was similar to the response in control SMCs. HB-EGF-induced autophosphorylation of EGF receptors was increased in STZ-SMCs compared with control SMCs, although the number of EGF receptors in STZ-SMCs was 40% of that in controls. This increased mitogenic response to HB-EGF in STZ-SMCs was completely inhibited by treatment with heparitinase, chlorate, and a synthetic peptide corresponding to the heparin-binding domain of HB-EGF. Compared with heparan sulfate isolated from control SMCs, heparan sulfate isolated from STZ-SMCs was of smaller molecular size and caused a greater mitogenic effect of HB-EGF. These findings suggest that the mitogenic response to HB-EGF is increased in SMCs of diabetic rats. Changes in cell-associated heparan sulfate in STZ-SMCs may be related to the increased mitogenic response to HB-EGF.
Animals↗