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Biomedical subjects

T Yasuda

Publications and source records attributed to T Yasuda.

At least 343 records · Page 19Linked to original sources
PubMed1996

Ginseng extract scavenges hydroxyl radical and protects unsaturated fatty acids from decomposition caused by iron-mediated lipid peroxidation.

This study was conducted to investigate whether or not the antioxidation effect of ginseng extract directly inhibits decomposition of unsaturated fatty acid caused by iron and hydrogen peroxide-induced lipid peroxidation, and whether this effect involves a hydroxyl radical-scavenging mechanism. Thiobarbituric acid-reactive substances (TBARS), gas chromatography, and electron spin resonance (ESR) spectrometer were used to measure lipid peroxidation, unsaturated fatty acid, and hydroxyl radical. The results showed TBARS formed and the loss of arachidonic acid during lipid peroxidation, and that hydroxyl radical formed by the Fenton reaction were completely inhibited by ginseng extract. This antioxidant effect of ginseng may be responsible for its wide pharmacological actions in clinical practice by a free radical reaction-inhibition mechanism.

Arachidonic Acid↗
PubMed1996

Pan-nephritis (glomerulonephritis, arteriolitis, and tubulointerstitial nephritis) associated with predominant mesangial C1q deposition and hypocomplementemia: a variant type of C1q nephropathy?

A 35-year-old man showed acute nephritic syndrome manifested as proteinuria, hematuria, and hypocomplementemia after upper respiratory infection. A renal biopsy showed mild to moderate mesangial proliferative glomerulonephritis with an accumulation of mononuclear cells in the capillary loop and with the deposition of C1q (graded as 3+), immunoglobulin (Ig) G, C3 (2+), IgA, IgM, and fibrinogen (weak to 1+), and mononuclear cell infiltration of the glomerular hilus, arterioles, and proximal tubules, which was a peculiar form of renal lesion. The mesangial deposition of C1q has been well documented in lupus nephritis, membranoproliferative glomerulonephritis, and endocapillary glomerulonephritis. The clinical signs and laboratory data in our patient ruled out these diseases. Although an immunofluorescence study showed these similarities to Clq nephropathy, the histopathological features of the peculiar arteriolitis and tubulointerstitial nephritis and laboratory findings of hypocomplementemia, as well as the good response to oral steroid therapy, differed from typical C1q nephropathy. The current patient appears to be a very rare phenotype of nephritis, being the only 1 case in almost 2,800 renal biopsies.

Adult↗
PubMed1996

Degradation kinetics and isomerization of cefdinir, a new oral cephalosporin, in aqueous solution. 1.

Hydrolytic degradation products of cefdinir were studied in acidic (pH 1), neutral (pH 6), and basic (pH 9) solutions. Seven major degradation products were isolated by preparative and/or high-performance liquid chromatography and characterized by UV, IR, 1H-NMR, and mass spectra. To clarify degradation pathways in each pH solution, kinetic and product analyses during hydrolysis of cefdinir were carried out along with the followup reaction of representative degradation products. Cefdinir was shown to degrade via two major degradation routes: beta-lactam ring-opening and pH-dependent isomerizations (lactonization, epimerization at C-6 or C-7, syn-anti isomerization of N-oxime function).

Administration, Oral↗
PubMed1996

Degradation kinetics and isomerization of cefdinir, a new oral cephalosporin, in aqueous solution. 2. Hydrolytic degradation pathway and mechanism for beta-lactam ring opened lactones.

Hydrolysis of cefdinir leads to pH-dependent isomerizations and beta-lactam ring-opening. Lactam ring opened gamma-lactones were produced as a mixture of four diastereoisomers based on the lactone methyl, and C-6 isomerizations in acidic to neutral solutions. Cefdinir and its 7-epimer were hydrolyzed to clarify the pathway leading to these lactones and the mechanism of C-6 epimerization with the aid of chiral separation techniques. Chiral separation using a bovine serum albumin column was employed to detect the beta-lactam ring opened products of cefdinir and its 7-epimer; the C-6 and C-7 isomerization was thereby observed; however, it was found to be pH-dependent at pH > or = 9. Optical activity detection applied to the lactones produced from cefdinir and its 7-epimer demonstrated that the corresponding peaks of these lactones were enantiomeric pairs. In addition, the smallest rate constant at pH 4 was observed for C-6 epimerization of the lactones, and it was found to proceed without deprotonation at C-6 by 1H-NMR spectroscopy. From the results of these studies, a plausible mechanism for C-6 epimerization has been proposed. Additionally, it was confirmed that two degradation pathways were involved during hydrolysis of cefdinir to the lactone.

Administration, Oral↗
PubMed1996

Pancreatoduodenectomy with preservation of the pylorus and gastroduodenal artery.

OBJECTIVE: The authors evaluated the rationale for and feasibility of gastroduodenal artery preservation in pylorus-preserving pancreatoduodenectomy (PPPD) for periampullary cancer in which the pancreatic remnant maintains a normal function and morphologic characteristics. SUMMARY BACKGROUND DATA: Pylorus-preserving pancreatoduodenectomy has become one of the standard treatments used for benign and malignant diseases of the pancreatoduodenal region, surpassing ordinary pancreatoduodenectomy in terms of technical ease, mortality rate, and postoperative nutrition. Pylorus-preserving pancreatoduodenectomy is usually associated with gastroduodenal artery division, which presents potential risks of insufficient duodenal vascularity and lethal postoperative bleeding from the gastroduodenal artery stump. The latter complication particularly occurs after resection of bile duct or ampullary cancer in a patient whose pancreas remains functionally and morphologically normal to have much more pancreatic secretion than the fibrotic pancreas seen in pancreatic cancer. According to the authors data on the volume of secretion from the residual pancreas via a stent tube after pancreatoduodenectomy, the sclerotic pancreas, as seen in cancer of the pancreatic head, secrets only 20 to 50 mL/day, whereas the secretion from the soft pancreas, as seen in bile duct cancer, amounts to 300 to 600 mL/day, even during the period of nothing by mouth. METHODS: Retrospectively, we made a histopathologic study of eight specimens of distal bile duct and ampullary cancer resected by pancreatoduodenectomy or PPPD with gastroduodenal artery division. Prospectively, we performed gastroduodenal artery- preserving PPPD for 10 patients with distal bile duct, ampullary, and islet cell cancers. RESULTS: The histopathologic study revealed no invasion or metastasis around the gastroduodenal artery. Clinical application of gastroduodenal artery-preserving PPPD showed no technical difficulty, and neither severe complications nor recurrence around the gastroduodenal artery were observed for up to 22 months after surgery. CONCLUSIONS: Gastroduodenal artery- preserving PPPD might be recommended as a safe procedure for patients who have a functionally and morphologically normal pancreas.

Aged↗
PubMed1996

Prognostication of proximal femoral growth disturbance after Perthes' disease.

Disturbance of proximal femoral growth associated with Perthes' disease was investigated retrospectively with the use of serial radiographs of 48 patients with unilaterally affected hips. Two types of proximal femoral growth abnormalities--moderately disturbed (6 patients) and severely disturbed (13 patients)--were observed and classified based on resultant femoral length shortening and femoral head deformity of affected hips. Proximal femoral growth disturbance after Perthes' disease was dependent on age at clinical onset: patients whose age at onset was greater than 8 years had a poor prognosis. Future femoral length shortening and femoral head deformity were also found to correlate with the extent of epiphyseal and physeal involvements and the acetabular coverage of the femoral head at the stage of regeneration of involved epiphysis. The current results raised the possibility that the severity of proximal femoral growth disturbance and abnormal growth patterns could be prognosticated based on the extent of epiphyseal and physeal involvements and on the lateralization of femoral head estimated on radiographs during the early stages of Perthes' disease.

Adolescent↗
PubMed1996

Prognostic value of the doubling time of serum C-reactive protein and alkaline phosphatase levels in primary bone and soft tissue tumors.

We investigated the clinical relevance of doubling time (DT) of serum laboratory data obtained in routine clinical examination of patients with primary bone and soft tissue tumors, in comparison with major clinical and pathological parameters (age at presentation, sex, tumor size, location, clinical stage and histologic grade) by uni- and multivariate analyses. In 64 patients with primary bone and soft tissue tumors (primary bone tumors: 39, primary soft tissue tumors: 25) and 68 cancer patients, the pretreatment DT values of serum C-reactive protein (CRP), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), calcium (Ca), phosphate (P) levels were measured, as well as the erythrocyte sedimentation rate (ESR: mm/60 min); these values were then compared with overall survival, local recurrence-free survival and metastasis-free survival. Only DT of CRP and ALP (CRP-DT, ALP-DT) were found to be correlated with disease outcome in patients with primary bone and soft tissue tumors. In cancer patients, only CRP-DT showed a relation with clinical stage and histologic grade, but the ALP-DT in patients with bone metastasis was significantly shorter than that in patients with metastases at other sites or in those with no metastasis. Among all tumor patients, those with bone metastasis showed the shortest ALP-DT compared with those with lung, liver and brain metastasis. Univariate analysis showed that shorter CRP-DT and ALP-DT are associated with poor overall survival, and the development of local recurrence and metastasis. These findings suggest that pretreatment CRP- and ALP-DT could be additional prognostic parameters for disease outcome in patients with primary malignant bone and soft tissue tumors. However, in multivariate analysis, only ALP-DT, but not CRP-DT, was an independent prognostic parameter for these disease outcomes.

Adult↗
PubMed1996

Multicopy suppressors of the cold-sensitive phenotype of the pcsA68 (dinD68) mutation in Escherichia coli.

The Escherichia coli strain cs2-68 is a cold-sensitive (c) mutant that forms a long filamentous cell at 20 degrees C with a large nucleoid mass in its central region. We have recently shown that the pcsA68 mutation causing the cs phenotype is a single-base substitution within the dinD gene, a DNA damage-inducible gene which maps at 82 min. Since null mutants of the pcsA (dinD) gene are viable, with no discernible defect in cell growth, the cs phenotype is attributed to a toxic effect by the mutant protein. In an attempt to identify a target(s) for the toxic pcsA68 mutant protein, we screened for chromosomal fragments on multicopy plasmids that could suppress the cs phenotype. Three different BamHI fragments were found to suppress cold sensitivity, and the lexA, dinG, and dinI genes were identified to be responsible for the suppression in each fragment. DinG shares multiple motifs with many DNA helicases. The complete sequence of dinI revealed that DinI is a small protein of 81 amino acids. It is similar in size and sequence to ImpC of the Salmonella typhimurium plasmid TP110 and to a protein (ORFfs) of the retronphage phi R67, both of which are also under the control of LexA.

Amino Acid Sequence↗
PubMed1996

Benign adult familial myoclonus epilepsy (BAFME): an autosomal dominant form not linked to the dentatorubral pallidoluysian atrophy (DRPLA) gene.

The genetic differences between two types of dominant inherited myoclonus epilepsy, dentatorubral pallidoluysian atrophy (DRPLA) and benign adult familial myoclonus epilepsy (BAFME), have been reported. A gene with a CAG repeat expansion responsible for DRPLA has been isolated. We have examined CAG repeat expansion in the DRPLA gene in five BAFME families, and the abnormal CAG expansion was not observed in the affected subjects. Linkage analysis using DNA polymorphisms in the DRPLA gene and the genes for gamma-aminobutyric acid (GABA) receptor subunits, GABAR beta 1, GABAR beta 3, and GABAR alpha 6, showed that these genes were not responsible for BAFME.

Atrophy↗
PubMed1996

Characteristics of high and low laminin-adherent Dunn osteosarcoma cells selected by adhesiveness to laminin. Correlation between invasiveness through the extracellular matrix and pulmonary metastatic potential.

We investigated the invasiveness through the extracellular matrix and pulmonary metastatic potential in high laminin-adherent [LN(+)] and low laminin-adherent [LN(-)] Dunn oseosarcoma cells selected for adhesiveness to laminin. In the invasion assay using a reconstituted basement membrane (matrigel) in a Boyden chamber, LN(+) cells proved to be more invasive than LN(-) and the parental Dunn cells. Pulmonary metastatic potential was correlated with invasiveness through the matrigel in three cell types. The ability of LN(+) cells to attach to laminin and the matrigel was significantly higher than that of LN(-) or the parental Dunn cells. LN(-) cells showed much lower attachment ability compared to the other cells. There were no significant differences in type IV collagenolysis and cell migration among the three cell types. In LN(+) and the parental Dunn cells, laminin significantly stimulated type IV collagenolytic and migration activities. LN(-) cells showed no significant differences of type IV collagenolysis and cell migration in response to laminin. These findings suggested that the different invasiveness of these cells was associated with the difference in the abilities of cell attachment to laminin and type IV collagenolysis and cell migration activities stimulated by laminin. YIGSR inhibited not only the laminin-mediated cell attachment but also the type IV collagenolysis and cell migration induced by the cell attachment to laminin. The amount of laminin receptor of LN(+) cells was about fourfold that of LN(-) and twofold that of the parental Dunn cells, suggesting the stimulatory effect of laminin on the invasiveness through the matrix is associated with the level of laminin receptor expression in these cells. The present study provides several findings suggesting that laminin has important roles in invasiveness through the extracellular matrix and metastasis formation in Dunn osteosarcoma cells.

Animals↗
PubMed1996

Spinal and femoral bone mass accumulation during normal adolescence: comparison with female patients with sexual precocity and with hypogonadism.

Since the attainment of higher bone mineral density (BMD) is a crucial strategy in preventing age-related bone loss and consequent fracture, we determined when bone mass of the lumbar spine (L2-L4) (g/cm2) and femoral neck (g/cm2) reaches its peak in healthy Japanese subjects and examined the influence of early exposure to estrogen and estrogen deficiency on BMD. We also determined the volumetric BMD, termed bone mineral apparent density (BMAD), of the lumbar spine and femoral neck. Using dual-energy x-ray absorptiometry (DXA) (Hologic QDR-1000), we measured BMD of both the lumbar spine and the femoral neck in 31 healthy children aged 2-11 yr, 269 children (138 males and 131 females) aged 13-19 yr, 12 men and 12 women aged 20-34 yr as adult controls, 11 patients with female central sexual precocity, and 3 patients with female primary hypogonadism. Because the densitometric data obtained from DXA are strongly influenced by the size of the bone in growing subjects, the volumetric BMAD (g/cm3) of the vertebral cube (L2-L4) and femoral neck were determined: BMAD (g/cm3) = BMD (g/cm2)/square root of scanned area (cm2) for the lumbar spine and by BMAD = BMD/width for the femoral neck. The BMD, both lumbar spine and femoral neck, nearly reached its peak at age 14.5-15 yr in girls and 16.5-17 yr in boys when compared with adult normal values. The difference in this age between sexes is identical to the difference in age at sexual maturation. BMD in patients with sexual precocity was high compared to age-matched controls, whereas patients with primary hypogonadism showed lower lumbar apparent BMD, and the increase in lumbar BMAD (g/cm3) was noted after the progression of puberty in healthy children, probably suggesting the importance of sex steroids in the increase of BMD and lumbar BMAD in both sexes. The girls with earlier menarche showed higher lumbar BMD at age 18 and 19 yr. For the femoral BMAD, there was no significant relationship between this value and age in girls. We conclude that peak bone mass is mainly achieved by late adolescence in Japanese as in Caucasians and that pubertal progression and probably estrogen itself play a crucial role in accumulation of bone mass in females.

Adolescent↗
PubMed1996

Oxygen-dependent-regulation of Ehrlich ascites tumor cell respiration by nitric oxide.

Effects of nitric oxide (NO) on oxygen uptake of Ehrlich ascites tumor cells (EATC) were examined in a study of the biological actions of NO on respiration and energy metabolism at the cellular level. Endogenous respiration of EATC was inhibited reversibly by NO in a dose dependent manner. Oxyhemoglobin, an NO trapping agent, restored the respiration promptly. The inhibitory action of NO also depended on oxygen-concentration, and the duration of suppression was prolonged remarkably at low oxygen tension. Similar inhibition was also observed in the presence of glucose. In this case, both lactate production and glucose consumption were promoted by NOC 18, an NO generating agent, and the activation was enhanced by lowering the oxygen-concentration. Furthermore, the membrane potential of EATC was depolarized transiently by adding NO, and the degree of depolarization was decreased in the presence of glucose. These results suggest that at physiologically low oxygen tension in ascites fluid, NO acts not only as a cytotoxic respiratory inhibitor but also as a regulatory factor in the energy metabolism of EATC.

Animals↗
PubMed1996

Urinary and biliary metabolites of genistein in rats.

Examination was made of the urinary and biliary excretion of the metabolites of genistein and genistein, the major components of Glycine and Sophora genus in rats. The urine of rats administered genistein orally contained eight metabolites. Three of these metabolites, genistein 4'-O-sulfate (M-1), genistein 7-O-beta-D-glucuronide (M-3), genistein 4'-O-sulfate 7-O-beta-D-glucuronide (M-6), were identified from spectroscopic and chemical data. The bile of rats administered genistein orally contained M-2, M-3 and M-6. M-6, a major biliary metabolite, was isolated and identified from spectroscopic and chemical data. The urine or bile of rats treated with genistein, the glycoside of genistein, contained M-1-M-8 or M-2, M-3, M-6 in the above metabolites. These findings suggest that genistein is absorbed as genistein after hydrolysis in the gastrointestinal tract. The total cumulative amounts of the two metabolites and genistein excreted in the urine during 48h, or of M-6 excreted in the bile during 36h following the oral administration of genistein, were approximately 5.7% or 16.0% of the doses administered, respectively. The result show that M-1, M-3 and M-6, having a free hydroxyl, glucuronide- or sulfate-conjugated hydroxyls at the C-7 or C-4' position, are excreted in the urine and bile as parts of the metabolites of genistein.

Animals↗
PubMed1996

Isolation and characterization of gangliosides from Theileria sergenti.

The gangliosides of Theileria sergenti piroplasms were isolated and analyzed by thin-layer chromatography (TLC) and TLC immunostaining test. Four species of gangliosides, designated as G-1, G-2, G-3, and G-4, were separated on TLC. G-1, G-2, G-3, and G-4 ganglioside showed the same mobility as GM3, sialosylparagloboside (SPG), i-active ganglioside, and I-active ganglioside on the TLC plate, respectively. In order to characterize the molecular species of gangliosides from T. sergenti, G-1, G-2, G-3, and G-4 gangliosides were purified and tested by TLC immunostaining test with monoclonal antibodies against gangliosides. G-1 ganglioside had reactivity to anti-GM3 monoclonal antibody. G-2 gave reaction with monoclonal antibody to SPG containing N-glycolylneuraminic acid (NeuGc). G-3 showed reactivity to the anti-i-active ganglioside (NeuGc) monoclonal antibody. G-4 was recognized by the monoclonal antibody which reacts with I-active ganglioside (NeuGc). In addition, sialic acid moiety of the gangliosides from T. sergenti piroplasms was also analyzed. N-acetylneuraminic acid-containing gangliosides were hardly detectable in T. sergenti piroplasms. Gangliosides from T. sergenti (G-1, G-2, G-3, and G-4) carried only NeuGc as their sialic acid moiety. These results suggest that G-1, G-2, G-3, and G-4 gangliosides are GM3 (NeuGc) [NeuGc alpha 2-3Gal beta 1-4Glc beta 1-Cer], SPG (NeuGc) [NeuGc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer], i-active ganglioside (NeuGc) [NeuGc alpha 2-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer], and I-active ganglioside(NeuGc) [NeuGc alpha 2-3Gal beta 1-4GlcNAc beta 1-3 (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-6) Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer], respectively.

Anemia↗
PubMed1996

Analysis of neutral glycosphingolipids of Theileria sergenti piroplasms.

Neutral glycosphingolipids (GSLs) were isolated from a lipid extract of Theileria sergenti piroplasms and analyzed by thin-layer chromatography (TLC) and liposome immune lysis assay (LILA); two predominant GSLs, designated as N-1 and N-2 were separated on TLC. N-1 GSL showed the same mobility as lactosylceramide (LacCer) on the TLC plate. On the other hand, the mobility of N-2 GSL on the TLC plate was identical to that of galactosylparagloboside. In order to characterize the molecular species of neutral GSLs from T. sergenti, N-1 and N-2 GSLs were tested by LILA with antibodies against LacCer and galactosylparagloboside, respectively, N-1 GSL had reactivity to anti-LacCer antibody and N-2 reacted with the antibody to galactosylparagloboside. These results suggest that N-1 and N-2 GSLs are LacCer (Gal beta 1-4Glc beta 1-1Cer) and galactosylparagloboside (Gal alpha 1-3Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc beta 1-1Cer), respectively.

Animals↗
PubMed1996

Early detection of infants with hypophosphatemic vitamin D resistant rickets (HDRR).

The onset of physical signs in infants with hypophosphatemic vitamin D resistant rickets (HDRR) has generally been considered to be at the age of 12 months, but the time of appearance of hypophosphatemia and rachitic signs on radiographs remains unclear. We report a prospective study in three neonates whose mothers were HDRR. At birth, despite a low maternal serum inorganic phosphorus (Pi) level, the serum Pi level was normal together with a negligible renal Pi leak in one neonate. At age 3 months, their serum Pi levels, percentages of tubular reabsorption of Pi, and renal tubular maximal rates of Pi reabsorption in relation to the glomerular filtration rate were low except for one infant. Radiographically, their rickets were not apparent at birth but at age 3 months in all. A premature born infant, born at 28 weeks' gestation weighing 1240 g, was diagnosed as HDRR based on hypophosphatemia due to low renal tubular maximal rate of phosphorus reabsorption in relation to the glomerular filtration rate (TmP/GFR) and normal urine Ca excretion at age 5 months. They were initially treated with 1 alpha-hydroxyvitamin D3 (1 alpha OHD3) and later with 1 alpha OHD3 in combination with Pi, which results in healing of the rickets and a normal increase in height. Thus, early detection and treatment of patients born from mothers with HDRR before physical signs of bow-leg and short stature is possible, but the outcome of early treatment requires further study.

Age of Onset↗