Biomedical subjects

S Yoshida

Publications and source records attributed to S Yoshida.

At least 937 records · Page 52Linked to original sources

PubMed1995

Effect of IL-4 and interferon-gamma (IFN-gamma) on IL-3- and IL-5-induced eosinophil differentiation from human cord blood mononuclear cells.

IL-4 and IFN-gamma positively and negatively regulate allergic inflammation. To determine the regulatory mechanisms of eosinopoiesis by cytokines, we examined the effect of recombinant IL-4 and IFN-gamma and of anti-IL-4 and anti-IFN-gamma antibodies on IL-3- and IL-5-induced eosinophil differentiation from human umbilical cord blood mononuclear cells. rhIL-4 (10-300 U/ml) inhibited IL-3- and IL-5-induced eosinophil differentiation from cord blood mononuclear cells on day 28 of culture by 62-81% in a concentration-dependent manner. rhIFN-gamma (5-500 U/ml) also inhibited IL-3- and IL-5-induced eosinophil differentiation by 80-99% in a concentration-dependent manner. The inhibitory effect of rhIL-4 and rhIFN-gamma was observed only when rhIL-4 or rhIFN-gamma were present in the culture from day 0 to day 14, but not from day 15 to day 28. Addition of anti-IL-4 antibody to the culture enhanced IL-3- and IL-5-induced eosinophil differentiation on day 28 of culture by 30%, whereas anti-IL-2 MoAb and anti-IFN-gamma MoAb had no significant effect. These results indicate that IL-4 and IFN-gamma have inhibitory effects on IL-3- and IL-5-induced eosinophil differentiation from its progenitor cells.

Antibodies↗

PubMed1995

Influence of the muscle tension on the masseteric silent period in children and adults.

Three subject groups who have shown different biting forces were examined in order to investigate whether the physiological phenomenon that the duration of the silent period (SPD) of the masseter muscle would be influenced by background activities of the muscles. They were classified into child (CN, n = 10) and adult groups; the adult group was then further subdivided according to the strength of maximum biting force into a normal group (AN, n = 10) and a low biting force group with some symptoms (AS, n = 5). SPD was observed in the masseter muscles by applying chin tap stimulations during both clenching teeth (10%, 50% and maximum) and biting on a transducer (50 N, 100 N and maximum). With increase of muscle activities, SPD was significantly decreased in the AN and CN groups, whereas no significant changes were found in the AS group. When comparing SPDs among the three groups at the same voluntary effort, the AN group exhibited the shortest SPD followed by the CN and AS groups. The results suggest that SPD was positively influenced by the strength of the background activities of the muscles and that immaturity of the masseters in terms of muscle activity could affect the SPD.

Adult↗

PubMed1995

A case report of Stevens-Johnson syndrome with Mycoplasma pneumoniae infection.

We encountered an 8 year old boy who suffered from Stevens-Johnson syndrome with Mycoplasma pneumoniae infection. He had multiple erythema with vesicles in oral mucosa, and on his palms and feet, trunk and genital regions. We treated him with prednisolone (1 mg/kg per day) and antibiotics. His skin lesions improved dramatically, and a persistent fever and toxic general condition also showed dramatic improvement. Although the use of corticosteroids for Stevens-Johnson syndrome has recently been controversial, we thought that administration of corticosteroids was an effective treatment for some selective cases of Stevens-Johnson syndrome. The patient reported in this study had many beneficial effects in response to corticosteroid treatment.

Cefamandole↗

PubMed1995

A truncated K-sam product lacking the distal carboxyl-terminal portion provides a reduced level of autophosphorylation and greater resistance against induction of differentiation.

The K-sam gene was originally cloned from KATO-III human gastric cancer cells and is identical to the bek or keratinocyte growth factor (KGF) receptor (KGFR) or fibroblast growth factor receptor 2 gene. K-sam generates several variant transcripts by alternative splicing, and the most abundant K-sam transcript in KATO-III cells was cloned as the K-sam-IIC3 cDNA, which has the KGF-binding motif and a short carboxyl terminus lacking a putative phospholipase C-gamma 1 association site, Tyr-769. The K-sam-IIC3 cDNA was distinct from the K-sam-IIC1 cDNA, which was the same as the previously reported KGFR cDNA. The K-sam-IIC1 product contains a long carboxyl terminus with Tyr-769. K-sam-IIC3 showed greater transforming activity in NIH 3T3 cells than did K-sam-IIC1, and in gastric cancer cell lines in general, the level of K-sam-IIC3 mRNA was greater than that of K-sam-IIC1 mRNA. Here we report that the K-sam-IIC3 product was less autophosphorylated than the K-sam-IIC1 product in NIH 3T3 transfectants. K-sam-IIC3-transfected keratinocytes showed a stronger mitogenic response to KGF than did K-sam-IIC1 transfectants. Moreover, K-sam-IIC3-transfected L6 myoblast cells hardly differentiated when cultured in differentiation-inducing medium and growth was not significantly affected, while K-sam-IIC1 transfectants showed a differentiated phenotype with a reduced growth rate. These data indicate the difference in the signal transduction mediated by two KGFR-type K-sam variants generated by alternative splicing which might be involved in certain differentiation and carcinogenesis scenarios.

Alternative Splicing↗

PubMed1995

Role of vascular cell adhesion molecule-1 and platelet-activating factor in selective eosinophil migration across vascular endothelial cells.

To determine the role of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in mediating selective eosinophil migration across vascular endothelial cells, we examined the effect of anti-ICAM-1 monoclonal antibody (mAb) and anti-VCAM-1 mAb on transendothelial migration of human eosinophils and neutrophils across IL-1- and IL-1-stimulated cultured vascular endothelial cells. We also studied the effect of a selective antagonist for platelet-activating factor (PAF) on the transendothelial migration of eosinophils and neutrophils. Transendothelial migration of eosinophils was increased by stimulation of the endothelial cells with IL-1 and IL-4, the latter of which has been shown to selectively induce VCAM-1 expression on the endothelial cells. On the other hand, neutrophil transendothelial migration was increased only by IL-1. Eosinophil migration across IL-4-stimulated endothelial cells was decreased by anti-ICAM-1 mAb and anti-VCAM-1 mAb. A selective PAF antagonist E6123 also decreased eosinophil migration across IL-4-stimulated endothelial cells. Eosinophil migration across IL-1-stimulated endothelial cells was also decreased by anti-ICAM-1 mAb and anti-VCAM-1 mAb in the presence of PAF antagonist. In contrast, neutrophil migration across IL-1-stimulated endothelial cells was decreased by anti-ICAM-1 mAb but not anti-VCAM-1 mAb. PAF antagonist alone or together with anti-VCAM-1 had no significant effect on IL-1-induced neutrophil transendothelial migration. These results indicate that VCAM-1 and PAF play an important role in mediating selective eosinophil migration across vascular endothelial cells.

Antibodies, Monoclonal↗

PubMed1995

Effect of a selective thromboxane A2 receptor antagonist BAY u3405 on antigen-, leukotriene C4- and leukotriene D4-induced bronchoconstriction in guinea pigs.

We studied the effect of a selective thromboxane (TX) A2 receptor antagonist BAY u3405 on prostanoid-, leukotriene (LT) C4, LTD4- and antigen-induced bronchoconstriction in nonanesthetized guinea pigs in vivo. Oral administration of BAY u3405 inhibited bronchoconstriction induced by inhaled TXA2 mimetic U46619, prostaglandin (PG) D2 and PGF2 alpha. BAY u3405 also decreased the bronchoconstriction induced by inhaled LTC4 and LTD4. Intraperitoneal administration of TXA2 synthetase inhibitor OKY-046 did not affect PGD2- and PGF2 alpha-induced bronchoconstriction, but attenuated LTC4- and LTD4-induced bronchoconstriction. BAY u3405 and OKY-046 decreased antigen-induced bronchoconstriction in actively sensitized guinea pigs. These results indicate that BAY u3405 not only inhibits TXA2-, PGD2- and PGF2 alpha-induced bronchoconstriction that is mediated through a TXA2 receptor but also decreases LTC4. LTD4- and antigen-induced bronchoconstriction which is mediated in part through TXA2 synthesis. These results suggest that BAY u3405 might be useful in controlling prostanoid-induced bronchoconstriction in asthma.

Animals↗

PubMed1995

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↗

PubMed1995

Insulin resistance associated with decreased levels of insulin-receptor messenger ribonucleic acid: evidence of a de novo mutation in the maternal allele.

Mutations in the insulin receptor gene may lead to insulin resistance and diabetes mellitus in some patients. We have studied an insulin-resistant patient with leprechaunism. Insulin binding to the patient's fibroblasts was markedly decreased. Determination of the nucleotide sequence of the patient's insulin receptor gene revealed heterozygosity for a 2-basepair deletion in exon 15. If the premessenger ribonucleic acid (pre-mRNA) is spliced normally, it causes a replacement of codon 970 in the beta-subunit with a premature chain termination codon, thereby deleting most of the intracellular domain of the receptor. The mRNA transcribed from the allele with a 2-base-pair deletion is likely to be unstable because mRNA transcripts from this allele could not be detected by complementary DNA sequencing. Northern blot analysis showed that the patient's insulin receptor mRNA was decreased by 90% compared with that of a control subject, thus suggesting that the patient is a compound heterozygote for two mutations that decrease levels of insulin receptor mRNA. This deletion mutation in exon 15 seems to be a de novo mutation, because it was not detected in either parent. Investigation of the inheritance of a silent sequence polymorphism in exon 17 provided that the deletion occurred in the maternal allele. Furthermore, linkage analysis suggests that the second mutation is derived from the patient's father, although we could not directly identify it by sequencing the coding region of the insulin receptor gene. Therefore, it is possible that this mutation is present in a regulatory domain of the insulin receptor gene, acting in cis-dominant fashion to reduce the levels of insulin receptor mRNA. Analyses of the hypervariable region in the myoglobin and pMCT118 loci were consistent with the assumption that the father and mother studied here are indeed the biological parents of the diseased patient. We hereby conclude that the patient is a compound heterozygote for two mutant alleles, both of which are responsible for the reduced levels of insulin receptor mRNA and insulin binding.

Adult↗

PubMed1995

Thyroxine binding properties of glycosylated human serum albumin as measured by fluorescence.

Thyroid hormone, thyroxine (T4) binding to glycosylated human serum albumin (G-HSA), and native human serum albumin (HSA) were studied as a function of pH using the fluorescence method. T4 binding affinity for G-HSA was remarkably reduced in an alkaline pH as compared with the native HSA. The thermodynamic parameters for binding are estimated at pH 7.5: (a) for G-HSA, delta G = -8.50 +/- 0.04 kcal mol-1 (30 degrees C), delta H = -5.2 kcal mol-1, delta S = +11 e.u.; (b) for HSA, delta G = -8.89 +/- 0.04 kcal mol-1 (30 degrees C), delta H = -3.5 kcal mol-1, delta S = +18 e.u. These results suggest that the glycosylation of HSA causes a variation in the electrostatic interaction between T4 and HSA.

Glycosylation↗

PubMed1995

Inhibitors of skin-tumor promotion. XIII. Inhibitory effects of euglobals and their related compounds on Epstein-Barr virus activation and on two-stage carcinogenesis of mouse skin tumors. (2).

One hundred and fifteen synthesized mono, di, and trihydroxybenzamide and thiobenzamide derivatives having structures related to euglobals were examined for their inhibitory effects on Epstein-Barr virus (EBV) activation by 12-O-tetradecanoylphorbol-13-acetate (TPA) as a primary screening test for anti-tumor-promoters. In general, 3-acyl-2,4,6-trihydroxybenzamide and 3-acyl-2,4,6-trihydroxythiobenzamide derivatives exhibited strong or moderate activities, and the latter compounds were less cytotoxic than the former. Meanwhile, little or no activity was observed with mono and dihydroxybenzamide and dihydroxythiobenzamide derivatives. Structural requirements for the activities of these compounds have been discussed in detail. Among the above compounds, compounds 36 and 73, which were significantly active on the inhibition of EBV activation, were investigated using a two-stage mouse skin carcinogenesis test induced by 7,12-dimethylbenz[a]anthracene (DMBA) and TPA. The results of the in vivo test showed that both compounds have a stronger inhibitory effect than that of the well-known anti-tumor-promoter, glycyrrhetic acid. These results suggested that the two compounds might be valuable as anti-tumor-promoters in chemical carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1995

Purification and some properties of alpha-galactosidase from Penicillium purpurogenum.

alpha-Galactosidase was purified by ion-exchange chromatographies on DEAE-cellulose and SE-cellulose columns from the culture filtrate of Penicillium purpurogenum No. 618. The final preparation was judged homogeneous by SDS-PAGE and its molecular mass and isoelectric point were estimated to be 67 kDa and 4.1, respectively. The N-terminal amino acid sequence of the enzyme was analyzed and aligned with those of other alpha-galactosidases. In addition, the enzyme acted on the stubbed alpha-galactosyl residue connected to the beta-1,4-manno-oligosaccharide chain, indicating that this specificity was quite different from that of Mortierella vinacea alpha-galactosidase.

Amino Acid Sequence↗

PubMed1995

Molecular cloning of cDNA for equine ovarian inhibin/activin beta A subunit.

cDNAs encoding equine inhibin/activin beta A subunit were isolated from an equine follicle cDNA library and characterized. Using primers based on the rat inhibin/activin beta A subunit cDNA sequence, a RT-PCR was performed to generate the probe for screening. Four positive clones were isolated. Analysis of the nucleotide sequence of these clones revealed that two pairs of identical clones were present, Eq-beta A-1 (0.9 kb) and Eq-beta A-2 (1.5 kb). Eq-beta A-2 clone contained a complete open reading frame encoding 426 amino acids. The deduced amino acid sequence of equine inhibin/activin beta A subunit showed high similarity (> 90%) to those of five other mammalian species. Northern blot analysis revealed that placenta from mare on day 180 of pregnancy contained a 1.5 kb inhibin/activin beta A subunit mRNA.

Activins↗

PubMed1995

Molecular cloning of DNA for inhibin alpha-subunit from equine ovary.

cDNA encoding equine inhibin alpha-subunit precursor protein was isolated from an equine ovarian cDNA library. For screening, the DNA probe was amplified by the RT-PCR using primers designed based on the rat inhibin alpha-subunit cDNA sequence. Out of 1.2 x 10(5) plaques screened, 19 positive clones were isolated, and one of these clones (Eq-alpha-11) contained a complete open reading frame encoding 367 amino acids. The similarity of the deduced amino acid sequences of both equine inhibin alpha-subunit precursor protein and the mature protein were greater than 80% to those of other six mammalian species, including bovine, porcine, ovine, human, rat and mouse. Northern blot analysis revealed that a single major band at 1.5 kb was present in the RNA samples both from equine follicles and testes.

Amino Acid Sequence↗

PubMed1995

Can high frequency ultrasound and MRI diagnose malignant atheromatous plaque in vitro?

It remains a vital clinical issue how to diagnose malignant atheromatous plaques consisting of ulcerative plaque and hemorrhagic plaque, which are potential risks for thrombosis and the arterial spasm. This study proposes further investigations to develop methods in order to detect this type of lesions by echocardiography. In this study, we tested high frequency (7.5 MHz) US and 1.0 T MRI (T1 weighted SE, STIR; short time inversion recovery sequence, and T1 weighted fat suppression technique) for their precision in the diagnosis of atheromatous plaque as malignant or benign in post mortem human aorta. Ten hemorrhagic plaques were imaged as heterogeneous echo- pattern in the shoulder of plaques covered with high-echo capsule with US; however, these findings were also obtained from 2 of 16 non-hemorrhagic plaques. With T1SE, hemorrhagic plaques were revealed as mixed areas of reduced intensity and high intensity which were differentiated from fatty deposition with T1 weighted fat suppression technique. Ulcerative plaques were revealed as concave shaped plaques and diagnosed correctly with both methods. US was superior to MRI from the viewpoints of examination time and measuring wall thickness. US indicated intimal plus medial thickness of hemorrhagic plaque and non-hemorrhagic plaque at 4.3 + 1.1 mm and 3.0 + 1.0 mm (p < 0.05) respectively. MRI was vulnerable to artifacts and its image was poorer in quality due to its lower resolution: however, probably because of its superior ability to distinguish fatty deposition from hemorrhage, MRI ultimately enabled more accurate diagnosis than US, as long as its image was fairly clear. The overall accuracies were 80% with US and 85.7% with MRI as confirmed by histological tests. From these results, the careful analysis of the two images obtained from US and MRI enables clinical diagnosis of malignant atheromatous plaques.

Aorta↗

PubMed1995

Anosmia following head trauma: preliminary study of steroid treatment.

Twenty patients with post-traumatic anosmia were subjected to olfactory function testing, including olfactory acuity tests using a T & T olfactometer and an intravenous olfaction test. T & T tests revealed complete loss in 14 patients. In the intravenous olfaction test, 14 patients showed no response and 5 patients showed abnormal responses. The severity of olfactory dysfunction showed no correlation with background factors such as the site of head trauma, the presence of the fracture of skull, the presence of unconsciousness, or the presence of head operation. As a preliminary study, seventeen patients were administered a corticosteroid, a topical nasal drop of 0.1% betamethasone for 12 patients and an oral administration of prednisolone for 5 patients. Four patients showed slight recovery of olfactory function following a corticosteroid therapy. Effects of corticosteroids on olfaction might be explained by regeneration of olfactory receptor cell axons and reestablishment of contact with cells in the olfactory bulb.

Adrenal Cortex Hormones↗

PubMed1995

Streptococcal toxic shock syndrome: report of two cases.

Two Japanese cases of streptococcal toxic shock syndrome (STSS) are reported. The first patient was a 45-year-old male who developed necrotizing fasciitis and myositis of the left thigh, refractory hypotension, hepatic dysfunction and acute renal failure; the patient died despite treatment. Streptococcus pyogenes was isolated from the inflamed fascia. The second patient was a 69-year-old female who had coagulopathy, polymyositis and hepatic function abnormality. Streptococcus pyogenes was isolated from blood culture. She was immediately placed on high-dose ampicillin as well as other supportive measures, and she survived.

Aged↗

PubMed1995

Synthesis and the stereoselective enzymatic hydrolysis of flurbiprofen-basic amino acid ethyl esters.

Ethyl esters of flurbiprofen L-arginine (FP-Arg-OH), flurbiprofen L-lysine (FP-Lys-OH) and flurbiprofen p-guanidino-L-phenylalanine (FP-GPA-OH) were synthesized and then the release of flurbiprofen enantiomers from these derivatives in the presence of trypsin (Tp), carboxypeptidase B (CPB) and carboxypeptidase Y (CPY) were examined in order to evaluate their availability as prodrugs for flurbiprofen (FP). The ester bonds of the three racemic FP derivatives were hydrolyzed by Tp at about 3 to 20 times the rates of N-benzoyl-L-arginine ethyl ester (Bz-Arg-OEt), a specific substrate for Tp. (R)-FP was released faster than (S)-FP by either CPB or CPY from both FP-Arg-OH and FP-Lys-OH. On the other hand, FP-GPA-OH was not hydrolyzed at all by CPB and the hydrolysis rate of this compound by CPY was very slow. (S)-Flurbiprofen L-arginine ethyl ester ((S)-FP-Arg-OEt) was separated from (R)-FP-Arg-OEt by high-performance liquid chromatography. A comparison of the kinetic parameters for the tryptic hydrolysis of the two optically active FP-Arg-OEt diastereomers and those of Bz-Arg-OEt suggested that the orientation of the scissile bond in each diastereomer to the catalytic center of Tp is more favorable than that of Bz-Arg-OEt. However, no significant difference was found between the kinetic parameters for the two diastereomers, suggesting that the orientational difference between (S)-FP and (R)-FP in the diastereomers does not have any effect on the tryptic hydrolysis of the ester bond.(ABSTRACT TRUNCATED AT 250 WORDS)

Arginine↗

PubMed1995

n-3 and n-6 fatty acid intake and serum phospholipid fatty acid composition in middle-aged women living in rural and urban areas in Okayama Prefecture.

Dietary fatty acids and serum lipids were evaluated in 68 middle-aged women living in the northern, rural area of Okayama Prefecture, and were compared with the values obtained from 65 urban women from the southern part of this prefecture. A higher level in HDL cholesterol and a lower atherogenic index were observed in the rural women. The percent of energy intake as fat was lower (20.4 +/- 0.8% vs. 23.2 +/- 0.7%) and that of carbohydrate was greater in the rural group. Eicosapentaenoic (EPA, 0.41 +/- 0.04 g/day) and docosahexaenoic acid (DHA, 0.70 +/- 0.08 g/day) intakes were significantly higher in the rural subjects than in the urban group. Significantly higher DHA levels and n-3/n-6 fatty acid ratios in serum total phospholipids were found in rural women in their fifties and the sixties compared to urban women. Dietary linoleic acid (LA) amounts were positively correlated with LA (p < 0.05), and negatively with the EPA (p < 0.05) and DHA (p < 0.01) contents of serum total phospholipids. These results suggest that the traditional Japanese diet, containing little fat but enriched in complex carbohydrates and n-3 fatty acids of marine origin, may be related to the low atherogenic index in this rural area.

Adult↗