Biomedical subjects

K Sudo

Publications and source records attributed to K Sudo.

At least 19 recordsLinked to original sources

PubMed1992

Simultaneous determination of nefiracetam and its metabolites by high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatographic assay was developed to simultaneously quantitate nefiracetam (NEF), a novel nootropic agent, and its three known oxidized metabolites (N-[(2,6-dimethylphenylcarbamoyl)methyl]succinamic acid (5-COOH-NEF), 4-hydroxy-NEF and 5-hydroxy-NEF) in human serum and urine. The quantitative procedure was based on solid-phase extraction with Sep-Pak C18 and ultraviolet detection at 210 nm. The calibration curves of NEF and the metabolites were linear over a wide range of concentrations (0.5-21.5 nmol/ml for NEF and 0.4-9.5 nmol/ml for metabolites in serum and 4-86 nmol/ml for NEF and 8-190 nmol/ml for metabolites in urine). Intra- and inter-day assay coefficients of variation for the compounds were less than 10%. The limit of detection was 0.1 nmol/ml for NEF, 5-COOH-NEF and 4-hydroxy-NEF, and 0.2 nmol/ml for 5-hydroxy-NEF in both serum and urine. This method is applicable for the determination of NEF and its metabolites in human serum and urine with satisfactory accuracy and precision.

Chromatography, High Pressure Liquid↗

PubMed1992

Molecular characterization of genetic mutations in human lactate dehydrogenase (LDH) B (H) variant.

We have previously detected a single base substitution of G by A at the Arg codon CGC in exon 4 of the mutant lactate dehydrogenase (LDH) gene, an unstable LDH-B variant (case 1). Here, we use the polymerase chain reaction (PCR) to amplify genomic DNA of two cases (the original case 1 and a new patient, case 2). We were able to confirm that case 1 is homozygous for the mutation, causing a replacement of the conserved Arg by His at residue 173. The resulting LDH-B variant subunit is unstable in vivo. Whereas the mutation in exon 4 was not observed in case 2, a different single base substitution of A by C was detected at the Ser codon AGT in exon 3. This mutation causes a replacement of the conserved Ser by Arg at residue 131. Genomic analysis of the family of case 2 by mismatched PCR showed that the missense mutation was consistent with their biochemical phenotypes. The replacement results in a conformational change of the residues near the Ser, probably because the side chain of Arg is much more bulky than that of Ser. The change may affect the arrangement of the cofactor binding site and result in the loss of enzyme activity. The experimental observations are consistent with computer graphics analyses.

Amino Acid Sequence↗

PubMed1992

Histological changes in the midbrain around the aqueduct in congenital hydrocephalic rat LEW/Jms.

Primary aqueductal stenosis is one of the main causes of congenital hydrocephalus in humans and experimental models. The congenitally hydrocephalic rat strain LEW/Jms is one such model. In this report, we describe further detailed histological features of periaqueductal structure, including the posterior commissure, subcommissural organ (SCO), and ependyma, and discuss the changes in these structures in relation to the cause of hydrocephalus. Coronal sections of the aqueduct in normal rats showed that the usual ependyma was absent in the center of the base facing the dorsal side, which was replaced by tall columnar cells. On the other hand, in hydrocephalic rats the ependyma encircled the aqueductal cavity. In midline sagittal sections, normal and hydrocephalic rats showed the SCO, although the SCO in hydrocephalic rats was shorter than in normal rats. There was also a marked difference between normal and hydrocephalic rats in the dorsoventral dimension of the rostral midbrain. In hydrocephalus, this dimension was large in comparison with normal rats. The superior collicular commissure located caudal to the posterior commissure ran along the ventral side of the midbrain in rats with hydrocephalus, and there was a cell-depleted area just dorsal to the superior collicular commissure. The same findings were observed from the 17th day of gestation until the postnatal period. Although the role of the SCO has been widely discussed from the viewpoint of secretory function, the present study indicated that this organ might be involved in the formation of the shape of the aqueduct.

Animals↗

PubMed1992

Single- and multiple-dose pharmacokinetics of nefiracetam, a new nootropic agent, in healthy volunteers.

The pharmacokinetic profile of nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide), a new nootropic agent, was studied in healthy Japanese male volunteers. Nefiracetam was administered orally at doses of 10-200 mg in the single-dose studies, and at doses of 200 mg three times a day for seven days in the multiple-dose study. An HPLC method was used to determine the concentrations of nefiracetam in serum, urine and faecal samples. Linear kinetic behaviour was obtained after single oral administration. Serum concentrations of nefiracetam reached maximum values (Cmax) within 2 h for all dosage groups, and declined monophasically after Cmax with half-lives of 3-5 h. The area under the concentration-time curve (AUC infinity) and Cmax were linearly related to the dose. The apparent clearance (CL) values were 94.4-140.3 mL min-1. Urinary excretion of nefiracetam was independent of the administered dose, and less than 10% of the dose was recovered in urine as the unchanged form within 24 h after administration. Renal clearance (CLR) did not change significantly as dose increased from 10 to 1200 mg. Faecal excretion of nefiracetam was less than 0.1% of the dose up to 24 h after a 300 mg oral dose. Food intake delayed the absorption of nefiracetam but did not significantly modify its pharmacokinetics. No clinically significant accumulation of nefiracetam in the body was observed during and after multiple doses.

Administration, Oral↗

PubMed1992

Chemical modification of fumagillin. I. 6-O-acyl, 6-O-sulfonyl, 6-O-alkyl, and 6-O-(N-substituted-carbamoyl)fumagillols.

The hydroxy group of fumagillol (3), a degradation product of fumagillin (1), was acylated, sulfonylated, alkylated or carbamoylated, and the anti-angiogenic activity of the resulting products was examined. These compounds inhibited the angiogenesis induced by basic fibroblast growth factor in the rat corneal micropocket assay and the growth of vascular endothelial cells in vitro. Among them, compound 2 (AGM-1470) was found to show the most potent inhibitory effect on the growth of vascular endothelial cells and was selected from this series as a candidate for further development.

Animals↗

PubMed1992

Serum total amylase activity and its isoenzyme fractions in newborn pigs with relation to growth and iron dextran-treatment.

Serum amylase activity was analyzed chromogenically (blue starch method) and its isoenzyme was separated by cellulose acetate membrane electrophoresis in newborn pigs comparing with those in adult pigs. Serum amylase activity in newborn pigs was about one half of adults' and increased with age. Serum amylase isoenzymes were separated into 4 fractions from the cathode. The isoenzymes were also classified in 5 types on the basis of the combination of these 4 fractions. Incidences of the fractions and the types were not significantly different between adults and newborns. After the iron dextran treatment, serum amylase activity as well as levels of erythrocytes, hemoglobin and packed cell volume increased. The rates of increase in hemoglobin and packed cell volume were more significant in the double treatment group than in the single treatment group, while serum amylase activity increased similarly in these 2 groups. The increase in serum amylase activity seemed to indicate that the development of amylase-producing organs was reinforced by the iron compound treatment. It is thought that serum amylase activity may be an indicator of healthy growth in newborn pigs.

Amylases↗

PubMed1992

Biochemical analysis of the bone of SHC rats with spontaneous hypercholesterolemia and renal dysfunction.

Spontaneously hypercholesterolemic (SHC) rats exhibit severe abnormalities in renal function and bone metabolism at old ages, in addition to hypercholesterolemia. SHC rats were also found to show endocrine abnormalities such as hyperthyroidism from young ages. In this study, biochemical and microdensitometric analyses were carried out using femurs to characterize further the abnormality in bone metabolism: whether biochemical markers of the bone may be affected by these abnormalities. At 6 weeks of age, the ashed weight and calcium content of the dried femurs were slightly lower in SHC rats than in age-matched Sprague-Dawley (SD) rats. None of the markers of microdensitometric analysis was changed. At 24 weeks of age, the ashed weight of dried femurs and the density of the marrow region of femurs were lower in the SHC rats. The results indicate that SHC rats exhibit severe abnormality in bone metabolism leading to biochemical changes in the bone at old ages whereas changes in bone markers were minimal at young ages before the onset of severe renal dysfunction.

Animals↗

PubMed1992

[Analysis of mononuclear cells in urine using flow cytometry: a useful tool for monitoring disease activity of proliferative glomerulonephritis].

We investigated CD56+ cells (natural killer cells), CD14+ cells (macrophage) and CD3+ cells (pan T cells) in urine using flow cytometry in various renal diseases including idiopathic crescentic glomerulonephritis, IgA nephropathy, membranoproliferative glomerulonephritis membranous nephropathy, pyelonephritis and idiopathic renal hematuria. A remarkable increase of CD56 cells in urine was observed in glomerulonephritis with marked necrotizing/and or crescentic (NC) lesions. The ratio of CD56+ cells/CD3+ cells was correlated with the severity of NC lesions. The ratio of CD14+ cells/CD3+ cells was increased in glomerulonephritis with endocapillary proliferation. Using immunohistochemical methods, CD56+ cells were also observed to be present in cellular crescents in biopsy specimens. These observations suggest that an analysis of these cells in urine using flow cytometry may be a useful tool for monitoring disease activity in proliferative glomerulonephritis.

Antigens, CD↗

PubMed1992

[Endoscopic closure of the postoperative bronchopleural fistula].

A case of successful endoscopic closure of a bronchopleural fistula with fibrin glue was reported. Fifty-eight-year-old man underwent right lower lobectomy for lung carcinoma. On the 21st postoperative day, he suffered from high fever and diagnosed as right side pyothorax. Then tube thoracotomy was done under UCG-guide. As a fistula in the right lower bronchial stump was found tiny by BFS, we tried to close the fistula bronchoscopically with fibrin glue. The fibrin glue was injected into the fistula via the ERCP tube, which was passed through the bronchoscope. This procedure was performed twice for two weeks interval. The fistula was completely closed about a month after the trial. This method is useful to close postoperative small bronchopleural fistula without surgical intervention.

Bronchial Fistula↗

PubMed1992

Molecular analysis of genetic mutation in electrophoretic variant of human lactate dehydrogenase-A(M) subunit.

An electrophoretic variant of lactate dehydrogenase-A (M) subunit was discovered in a patient with multiple myeloma. DNA analysis of the variant allele revealed a nucleotide substitution (transition) of C to T at codon 314 (CGT-TGT), and this mutation resulted in the replacement of an arginine by a cysteine (R314C). This amino acid replacement affects the net charge of the subunit and makes the LDH-A variant have a faster electrophoretic mobility. The responsible missense mutation created a new restriction site, AGGCCT, which can be simply detected by endonuclease AatI digestion. In addition, four synonymous substitutions with no amino-acid replacements were found at codons 51, 119, 163 and 175 in the LDH-A gene from the patient.

Aged↗

PubMed1992

[Successful treatment with steroid pulse therapy in a case of dilated cardiomyopathy associated with mesangial proliferative glomerulonephritis].

A 28-year old male was admitted to our hospital because of heart failure, chronic renal failure and nephrotic syndrome. Light microscopic findings of his kidney biopsy showed proliferation of mesangial cell and marked narrowing the lumina of small arteries and arterioles. The changes of these small vessels were not those of typical vasculitis, when we considered his age and his past history. The diagnosis of dilated cardiomyopathy was made by the findings in echocardiography and cardiac catheterization. Since the heart failure and renal disease seemed to be simultaneous initiated, it was supposed that the diseases in two organs were caused by a common pathogenesis related to that of vasculitis. When steroid pulse therapy was adopted, both of cardiac and renal function responded to this treatment (ejection fraction from 26% to 52%, creatinine clearance from 48 to 62 ml/min). Increase of CD56 positive cells (natural killer cells) in peripheral blood was ameliorated after the treatment. These findings suggest that cellular immunity may be concerned with the pathogenesis of the combination of dilated cardiomyopathy and renal disease in this case.

Adult↗

PubMed1991

Analysis of genetic mutations in human lactate dehydrogenase-A(M) deficiency using DNA conformation polymorphism in combination with polyacrylamide gradient gel and silver staining.

Human lactate dehydrogenase (LDH)-A mutant gene was analyzed by polymerase chain reaction - DNA conformation polymorphism (DCP). We used polyacrylamide gradient gel and silver staining procedures for DCP analysis and observed abnormal migration patterns in individuals heterozygous for LDH-A deficiency. Further sequence determination of the mutant alleles consistently resulted in detection of base substitutions, a G to T transversion at codon 328 (GAG----TAG), and synonymous substitutions at codon 115, 160 and 172. Such mutations were easily detectable using the DCP technique. The DCP technique using the polyacrylamide gradient gel and silver staining method seems likely to be useful for the rapid screening of mutations and for further genotype detection.

Amino Acid Sequence↗

PubMed1991

Potent anti-angiogenic action of AGM-1470: comparison to the fumagillin parent.

The anti-angiogenic activity of AGM-1470, a new synthetic analog of fumagillin isolated from Aspergillus fumigatus, was extensively examined both in vitro and in vivo using four different types of assay and compared to that of the fumagillin parent. Locally administered AGM-1470 inhibited the angiogenesis in the chick embryo chorioallantoic membrane assay and the rat corneal assay. In the rat sponge implantation assay, systemically administered AGM-1470 inhibited angiogenesis induced by basic fibroblast growth factor. Furthermore, in the rat blood vessel organ culture assay, AGM-1470 (1-1,000 ng/ml) was found to selectively inhibit the capillary-like tube formation of endothelial cells with a minimal effect on the non-endothelial cell growth. AGM-1470 showed more potent anti-angiogenic activity and less toxicity than the fumagillin parent. Therefore, AGM-1470 is much better than the fumagillin parent as anti-angiogenic compound.

Animals↗

PubMed1991

Genotypic analysis of families with lactate dehydrogenase A (M) deficiency by selective DNA amplification.

Genomic DNA prepared from LDH-A-deficient whole blood was amplified by the polymerase chain reaction technique using two primers specific for the active human LDH-A gene. The amplified fragment was examined by direct agarose gel electrophoresis, and a deletion of 20 base pairs (bp) in exon 6 of the LDH-A gene was found. The results permitted a clear distinction between the homozygous mutant, the heterozygous mutant, and wild-type genotypes. Moreover, HinfI digestion and direct sequencing of the amplified product confirmed the results from direct agarose gel electrophoresis. Four families, including 18 individuals, were shown to contain the same mutation, that is a 20-bp deletion in exon 6. All genotypes were consistent with their biochemical phenotypes as evaluated by the ratio of LDH-B to LDH-A subunits in erythrocytes. Thus, all four known affected families in Japan have been shown to carry the same mutant gene, which may have been derived from a single mutational event.

Amino Acid Sequence↗

PubMed1991

Prenatal aqueductal stenosis as a cause of congenital hydrocephalus in the inbred rat LEW/Jms.

We studied the microscopic morphological changes in congenital hydrocephalus in the inbred rat, LEW/Jms, on gestational days 17, 18, and 20 and during the neonatal period to clarify the etiopathogenesis, focusing particularly on the aqueductal changes. At 1 day of age, ventriculomegaly was limited to the lateral and III ventricles, and the aqueduct was obstructed, with the appearance of simple stenosis. On gestational days 20 and 18, the hydrocephalic rats showed occluded aqueducts, which paralleled the finding of hydrocephalus in the newborn rats. On gestational day 17, all eight models examined showed the same size ventricles. However, an aqueductal obstruction was observed in one of them. The other seven rats showed the aqueduct patent. From these observations, it can be concluded that the rat shows an aqueductal obstruction on gestational day 17 and appears to develop hydrocephalus with age. The aqueductal obstruction was considered to be the primary change and not a secondary phenomenon. The site of obstruction was the anterior part of the aqueduct (level of anterior colliculus) at every stage. Aqueductal obstruction following the developmental anomaly of the midbrain in the embryonic stage might thus be the primary cause of congenital hydrocephalus in rats LEW/Jms.

Animals↗

PubMed1991

Epigenetic control of tumor cell morphology.

XC cell line derived from a single rat cell transformed by the Prague strain of Rous sarcoma virus produced morphologically different colonies. Among them, two distinct cell types consisting of thick, fusiform cells (L-type), and of flat, polygonal cells (R-type) were apparent. By repeated subclonings, pure cultures, L1 and R1, respectively, were obtained. These clones underwent morphological conversion during prolonged culture; L-type colonies appeared in the R-type clone and vice versa. The kinetic curve suggested that the conversion was multi-stepped. When inoculated into nude mice, L-type cells produced much larger tumors at a higher frequency than R-type cells, and the tumors induced by these two clones were histologically different. The expression of v-src gene was higher in L-type than in R-type cells at both mRNA and protein levels.

Actins↗

PubMed1991

Effects of gomisin A on hepatocarcinogenesis by 3'-methyl-4-dimethylaminoazobenzene in rats.

We examined the effects of gomisin A on tumor promotion in the liver after a short-term feeding of 3'-methyl-4-dimethylaminoazobenzene (3'-MeDAB) to rats, compared with the effects of phenobarbital. Male Donryu rats were fed ad libitum a diet containing 0.06% 3'-MeDAB and 0.03% or 0.01% gomisin A or water containing 0.05% phenobarbital. Gomisin A and phenobarbital did not cause any proliferative and neoplastic lesions by themselves in 40 weeks of feeding. Altered foci in the liver increased with a peak at 12 weeks after the rats were fed 3'-MeDAB. Gomisin A decreased the number of hepatic altered foci such as the clear cell and basophilic cell type foci in the early stages. Phenobarbital enhanced neoplastic alterations so that the number and size of the foci were much larger in the phenobarbital-combined group than in the 3'-MeDAB-control group. Thus, phenobarbital acted as a promoter of cells initiated by 3'-MeDAB; on the other hand, gomisin A showed a weak suppressive effect on tumor promotion.

Animals↗

PubMed1991

Effects of TAP-144-SR, a sustained-release formulation of a potent GnRH agonist, on experimental endometriosis in the rat.

A new, simple experimental endometriosis model was established by auto-transplanting endometrial tissue fragments beneath kidney capsules in female rats. The transplanted endometrial tissue grew well, forming a fluid-filled cyst, which reached maximal size 2 to 3 weeks after transplantation. The growth and maintenance of the transplants was dependent on the ovary: ovariectomy induced regression of well grown transplants. The therapeutic effects of TAP-144-SR (biodegradable microcapsules of copoly (DL-lactic/glycolic acid) copolymer containing a potent GnRH agonist, TAP-144 (D-Leu6-[des-Gly10-NH2]-GnRH ethylamide, leuprolide acetate) were studied with this rat endometriosis model. A single sc injection of TAP-144-SR (corresponding to 1, 10 or 100 micrograms/kg/day of TAP-144), suppressed the growth of the transplanted endometrial tissues and uterine weight in a dose-dependent manner. At 100 micrograms/kg/day, the suppressive effect was more marked in rats given TAP-144-SR than in those given TAP-144 solution. The extent of suppression was comparable to that caused by ovariectomy. Serum and pituitary concentrations of LH and FSH were also reduced more markedly by the administration of TAP-144-SR than by TAP-144 solution. From these results, the present endometriosis model was found to be useful for the evaluation of compounds with potential therapeutic activity. The sustained-release formulation of TAP-144 seems to be beneficial over its solution in terms of both convenience and efficiency for therapy of patients with endometriosis.

Animals↗