Biomedical subjects

M Hayashi

Publications and source records attributed to M Hayashi.

At least 433 records · Page 24Linked to original sources

PubMed1999

Relationship between endothelin-1 extraction in the peripheral circulation and systemic vascular resistance in patients with severe congestive heart failure.

OBJECTIVES: This study was done to determine the spillover and extraction of endothelin-1 (ET-1) in the peripheral circulation, and to evaluate the factors that regulate local ET-1 extraction in the peripheral circulation in patients with congestive heart failure (CHF). BACKGROUND: The relationship between the spillover and extraction of the ET-1 in the peripheral circulation and systemic vascular resistance (SVR) has not been fully clarified. METHODS: We measured plasma levels of ET-1 both in femoral artery (FA) and femoral vein (FV) in 93 patients with CHF. RESULTS: Plasma ET-1 was significantly higher in FV than in FA in New York Heart Association (NYHA) functional class II patients, but there was no difference of ET-1 between FA and FV in functional class III patients. In patients with functional class IV, plasma ET-1 was significantly lower in FV than in FA, and SVR was significantly higher than in patients with NYHA class II or class III. Moreover, a significant positive correlation existed between plasma ET-1 extraction across the lower leg and SVR in these patients. Among the various neurohumoral factors and hemodynamics, plasma levels of ET-1, angiotensin II in the FA showed an independent and significant relationship with the plasma arteriovenous difference of ET-1 in the lower limb. CONCLUSIONS: Circulating ET-1 is extracted in peripheral circulation in patients with severe CHF, suggesting the possibility of upregulation of ET receptors of vascular beds in the lower limb in these patients. The peripheral extraction of ET-1 correlates with SVR in severe CHF patients and is mainly regulated by the local ET-1 and renin angiotensin systems.

Adolescent↗

PubMed1999

Clinical assessment of collagen cross-linked N-telopeptides as a marker of bone metabolism in patients with primary hyperparathyroidism.

This study assesses the clinical usefulness of collagen cross-linked N-telopeptides (NTx), a new marker for bone resorption, as a marker for primary hyperparathyroidism. The study was conducted on 114 patients who had undergone parathyroidectomy for primary hyperparathyroidism. Urine NTx levels were longitudinally determined by ELISA. Longitudinal serum bone Gla protein (BGP) determinations and dual energy X-ray absorptiometry (DEXA) examinations were also performed before and after parathyroidectomy. Before parathyroidectomy, the mean urine NTx level in primary hyperparathyroidism was 149.0 +/- 116.8 pmol BCE/mumol Cr (normal: < 55 pmol BCE/mumol Cr), and the positive rate was 88.5%. The mean BGP level was 33.5 +/- 59.1 ng/mL (normal: 12.7 ng/mL), and the positive rate was 77.7%. The NTx positive rate was higher than the BGP positive rate. NTx values were significantly correlated with bone mineral density (P < 0.002) and BGP values (P < 0.005). Two weeks after parathyroidectomy the NTx levels had already decreased significantly to 65.1 pmol BCE/mumol Cr (P < 0.001), and by one month postoperatively they had fallen to 55.9 pmol BCE/mumol Cr, reaching the normal range much sooner than BGP. The NTx normalization rate two weeks postoperatively was 37%, and by 12 months postoperatively it was normal in 83% of patients. BGP levels decreased more gradually than the NTx levels, and only became normal in 9% of cases two weeks postoperatively, as opposed to 74% by 12 months. It is concluded that NTx reflects bone turnover in primary hyperthyroidism, and that it is an excellent marker for bony lesions before and after parathyroidectomy.

Biomarkers↗

PubMed1999

Expression of multidrug resistance-associated protein in endometrial carcinomas: correlation with clinicopathology and prognosis.

The objective of the study reported here was to investigate the expression of multidrug resistance-associated protein (MRP) in endometrial carcinomas and to evaluate the relationship between its expression and clinical data. Using immunohistochemistry, we examined MRP expression in 15 normal endometria, 10 cases of endometrial hyperplasia, and 64 cases of endometrial carcinoma. The normal endometrial glands were weakly immunopositive throughout the menstrual cycle. In addition, we found a progressive increase in the MRP expression of the endometrial hyperplasias. Of the 64 cases of endometrial carcinoma, 62 (97%) expressed MRP. Of these 62 cases, 34 (55%) showed strong immunostaining (>/=50%) and 28 (45%) showed weak immunostaining (<50%). In particular, the intensity of the immunostaining was very strong in 25 (71%) of the 35 grade 1 carcinomas. There was a significant difference in MRP expression between the grade 1 carcinomas and the more poorly differentiated carcinomas (grade 2 or grade 3) (P <.01), especially at stages 1a and 1b (P <.001). However, beyond stage 1c, there was no significant difference in MRP immunoreactivity between the histologic differentiations. Furthermore, beyond stage 1c, those patients with strongly MRP-positive carcinomas had a relatively poorer survival rate than those with weakly MRP-positive carcinomas (P <.05). We concluded that MRP immunoreactivity was already present in normal endometrium and showed a progressive increase from endometrial hyperplasia to well-differentiated carcinoma. Beyond stage 1c, strongly MRP-positive carcinoma indicated a poorer survival rate.

ATP-Binding Cassette Transporters↗

PubMed1999

The effects of a 20 min nap in the mid-afternoon on mood, performance and EEG activity.

OBJECTIVE: The aim of the study is to examine the effects of a 20 min nap in the mid-afternoon on mood, performance and EEG activities. METHODS: Seven young adults who had normal sleep-wake habits without habitual daytime napping participated in the study. They underwent Nap and No-nap conditions at intervals of 1 week. After a nocturnal sleep recording (00:00-08:00 h), their EEG recordings during relaxed wakefulness, and their mood, performance and self-ratings of performance level were measured every 20 min from 10:00 to 18:00 h. For the nap condition, they went to bed at 14:00 h and were awakened when 20 min had elapsed from the onset of sleep stage 1. For the No-nap condition, they took a rest without sleep by sitting on a semi-reclining chair. RESULTS: All of the subjects were awakened from sleep stage 2 during the nap. The 20 min nap improved the subjective sleepiness, performance level and self-confidence of their task performance. The nap also suppressed EEG alpha activity during eyes-open wakefulness. CONCLUSIONS: The results suggest that a short 20 min nap in the mid-afternoon had positive effects upon the maintenance of the daytime vigilance level.

Adult↗

PubMed1999

S-cone electroretinogram to Ganzfeld stimuli in patients with retinitis pigmentosa.

Cone electroretinograms (ERGs) elicited by different chromatic stimuli were recorded from patients with typical retinitis pigmentosa (RP) younger than 50 years of age. Ganzfeld color flashes on a bright white background illumination were used to elicit short-wavelength-sensitive (S-), and mixed long- (L-) and middle- (M-) wavelength-sensitive cone ERGs. Three patients with dominant inheritance, 22 patients with non-dominant inheritance, and 27 age-similar normal subjects were compared. Although the b-wave amplitudes of both the S- and L,M-cone ERGs were reduced in the RP patients, the S-cones were reduced to a greater degree than the L,M-cones. No significant difference in the S-cone reduction was observed between patients with dominant inheritance and those with non-dominant inheritance. The selective reduction of the S-cone system, reported previously in psychophysical studies, may be attributable not only to the macular region but also to the entire retina.

Adolescent↗

PubMed1999

Comparative effects of vitamin K2 and vitamin E on experimental arteriosclerosis.

The comparative effects of vitamin K2 and vitamin E on aortic calcium (Ca) and inorganic phosphorus (P) levels in the aorta and the elastin fraction (fr.) were investigated in male rats after experimental arteriosclerosis was induced by vitamin D2 with atherogenic diet. Both vitamin K2 (100 mg/kg b.w.) and vitamin E (40 mg/kg b.w.) inhibited the increase of Ca and P in the aorta and the elastin fr. from the arteriosclerotic rats. Vitamin K2 (50 mg/kg b.w.) also suppressed the deposition of Ca and P in the aorta, but there was no change due to vitamin K3 or geranylgeraniol (side chain of vitamin K2) administration. Both vitamin K2 and vitamin E showed lipid radical scavenging activity in the in vitro experiment. However, neither vitamin K3 nor geranylgeraniol exhibited anti-arteriosclerotic or radical scavenging activity under the above experimental conditions. It is suggested that vitamin K2 and vitamin E promoted an antiarteriosclerotic effect by radical scavenging activity. These actions of vitamin K2 are required in the structure of 2-methylnaphtoquinone and its side chain (geranylgeraniol).

Animals↗

PubMed1999

Long-term outcomes in pediatric liver recipients: comparison between cyclosporin A and tacrolimus.

In recent years, tacrolimus (FK506, TAC) has been increasingly utilized in liver transplantation. However, long-term risks and benefits as compared with conventional cyclosporin A (CsA) have not been fully elucidated. This retrospective study examined the potential outcome differences between TAC- and CsA-based immunosuppressive therapy in pediatric liver transplant recipients. From March 1988 to December 1996, 218 children (aged 0.1-17 yr) underwent 238 orthotopic liver transplantations; 58.7% (128/218) were under 2 yr of age at time of transplant. Initially, the maintenance immunosuppressive regimen consisted of CsA and prednisone, with antilymphocytic preparations (MALG, ATGAM, and OKT3) as induction therapy. Subsequently, TAC was used first as rescue therapy for steroid refractory rejection in CsA patients and then as maintenance immunosuppression. Fifty-seven out of the 147 CsA patients were converted to TAC for various reasons while 71 patients were placed on TAC as primary maintenance immunosuppression. 62.6 per cent (92/147) of liver recipients on CsA experienced at least one biopsy-proven acute rejection episode as compared to 50.7% (36/71) for TAC patients (p = 0.09); likewise, 34% (50/147) of CsA patients had more than one episode of rejection vs. 18.3% (13/71) for patients on TAC (p < 0.02). Rejection was the reason for conversion from CsA to TAC in 29 of 57 patients. Conversely, 19.0% (28/147) of CsA patients had to be switched to TAC for reasons not related to rejection (i.e. side-effects). The overall incidence of histologically proven chronic rejection was 7.8% (17/218). 10.9 per cent (16/147) of the children who were on CsA initially developed chronic rejection, which was significantly higher compared with one of 71 TAC recipients (p < 0.02). Of these 16 CsA patients with chronic rejection, 50.0% (8/16) underwent retransplantation for graft failure (mean interval from time of diagnosis of chronic rejection to re-transplant, 4.0 months; range 1-8 months), whereas the TAC patient has remained clinically stable with normal liver function tests after 23 months of follow-up. One year after liver transplantation, 72.8% (107/147) of CsA patients were still on steroids (mean dosage 0.20 mg/kg/d), as compared to 42.3% (30/71) of the TAC patients (mean dosage 0.14 mg/kg/d). The incidence of post-transplant lymphoproliferative disorder (PTLD) in Epstein-Barr virus (EBV)-infected patients was 2.2% (2/90), 7.0% (5/71) and 12.3% (7/57) for CsA, primary and TAC-converted groups, respectively. The overall incidence of PTLD was 6.9% (15/218). In summary, pediatric liver transplant recipients treated with TAC as primary maintenance immunosuppressive medication experienced significantly fewer episodes of rejection; especially chronic rejection, which lead to graft loss. However, the trade-off is a potential increased incidence of EBV-related PTLD in these patients.

Acute Disease↗

PubMed1999

Living related liver transplantation from heterozygote genetic carriers to children with Wilson's disease.

We reviewed the outcome of children undergoing living related liver transplantation (LRLT) for Wilson's disease (WD), and specifically addressed the potential risk associated with the use of donors who were heterozygous for the Wilson genetic defect. LRLTs were carried out in 11 children with WD, nine of whom presented with fulminant hepatic failure and two with end-stage hepatic insufficiency. The age of the patients ranged from 6 to 16 yr. Eight patients had hepatic encephalopathy and were plasmapheresed preoperatively. The donors (all parents: six fathers and five mothers) were all one-haplotype matched with their respective recipients, and were all therefore heterozygote carriers of the WD genetic defect. The serum ceruloplasmin levels were within normal limits in all donors (mean: 20.0 +/- 2.85 mg/dL). All recipients but one had low serum ceruloplasmin levels with a mean value of 11.6 +/- 7.36 mg/dL before transplantation. The serum ceruloplasmin levels had increased to an average of 21.0 +/- 3.76 mg/dL after LRLT at the latest evaluation, which ranged between 7 and 75 months after transplantation. A marked reduction in urinary copper excretion was observed in all recipients after transplantation. Of eight recipients presenting preoperatively with Kayser-Fleischer (K-F) rings, this abnormality resolved completely after LRLT in five patients and partially in three. All recipients are alive and remain well, and none have developed signs of recurrent WD after a mean follow-up period of 31 months (range 7-75 months). In conclusion, LRLT is an excellent choice for effective treatment of WD, and grafts chosen from heterozygote carriers of the condition do not appear to confer any risk of recurrence in the recipients.

Adolescent↗

PubMed1999

The expression of p73 is increased in lung cancer, independent of p53 gene alteration.

p73 gene, a new p53 homologue, has been identified: it supposedly acts as tumour suppressor gene in neuroblastoma. To clarify whether p73 might be involved in lung carcinogenesis, we examined p73 expression in resected lung cancer and paired normal lung in 60 cases using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). We also examined p73 gene status in three representative cases using Southern blot, and p53 gene alteration in 49 cases using PCR-single-strand conformation polymorphism (PCR-SSCP) and direct sequence. In 87% of the cases (52/60) p73 expression in tumour was more than twice as high as that in paired normal lung tissues, and the difference between p73 expression in tumour and normal lung tissue was significant (P < 0.0001). However, Southern blot analysis revealed that none of the cases showed p73 gene amplification. Compared with clinicopathological characteristics, p73 expression correlates significantly with histological differences and age of patient, independently (P < 0.05). Concerning p53 gene status, 43% (21/49) showed p53 gene alteration, but there was no correlation between p73 overexpression and p53 gene alteration. Our results suggest that need for further functional analysis of the role of p73 in lung carcinogenesis.

Adult↗

PubMed1999

The interaction of cellular fibronectin with collagen during fibroblast-mediated contraction of collagen gels.

In the first instance highly hydrated collagen gels contract to dense and compact gels when populated by fibroblasts. We previously reported the involvement of fibronectin (FN) in an early process of the collagen gel contraction, utilizing a specific monoclonal antibody dubbed A3A5 (MoAb-A3A5) that inhibits the gel contraction. This study was performed to further characterize the role of the epitope for MoAb-A3A5 in the interaction between fibroblasts and collagen fibrils. Although both cellular FN (cFN) and plasma FN (pFN) were reactive with MoAb-A3A5, the FN that actually participates in a process of the gel contraction was shown to be cFN. The gel contraction was significantly accelerated when fibroblasts were pretreated with excess amounts of cFN and was significantly inhibited when the collagen molecules were pretreated with excess cFN. Such effects of the pretreatments were not observed for pFN. The involvement of cFN, but not pFN, in the interaction of fibroblasts with collagen fibrils was additionally shown by the similar inhibitory action of cFN, but not pFN, on the spreading and elongation of fibroblasts on collagen fibrils. The epitope for MoAb-A3A5 was strongly suggested to be a new functional domain responsible for the interactions between fibroblasts and native collagen molecules. This was not the case for those with denatured one, because fibroblasts on collagen fibrils were not stainable with MoAb-A3A5, whereas the interactions on gelatin were stainable. The lack of the reactivity of fibroblasts on collagen fibrils toward MoAb-A3A5 was not a result of the absence of FN on the cell membrane, but seemed to be a steric hindrance to the access of the antibody.

Antibodies, Monoclonal↗

PubMed1999

Functional interleukin-5 activity in peripheral blood mononuclear cells from adolescents with mite antigen asthma in remission.

BACKGROUND: Asthma improves in most children during adolescence such that a small minority of patients exhibit clinically significant symptoms by the age of 20 years. OBJECTIVE AND METHODS: To investigate late allergic reactions, including eosinophil inflammation, associated with outgrowing mite antigen-induced bronchial asthma during adolescence, the relationship between clinical status and functional activity of interleukin (IL)-5 produced by Dermatophagoides farinae (Df)-stimulated peripheral mononuclear cells (PBMCs) in culture was assessed in mouse IL-3-dependent cells transfected with the human IL-5 receptor gene. RESULTS: Activity of IL-5 spontaneously produced by PBMCs from either patients with mite-sensitive bronchial asthma or nonatopic control subjects was low. The activity of IL-5 produced by PBMCs stimulated with concanavalin A was significantly higher. Upon challenge with specific allergens, such as Df antigen, but not with irrelevant antigens, including ovalbumin, the in vitro activity was increased in patients with active disease and decreased in patients in remission. CONCLUSION: Results suggest that the antigen-specific up-regulation of functional IL-5 activity in late allergic reactions is reduced in patients in remission and likely to result in an improvement in clinical status. The Df antigen may suppress Df-induced responses in patients with asthma in remission.

Adolescent↗

PubMed1999

Inducible nitric oxide synthase activity by interferon-gamma-producing cells in human radicular cysts.

AIM: In this study, the interaction of interferon-gamma-(IFN-gamma) and inducible nitric oxide synthase (iNOS)-producing cells in human radicular cysts were investigated. METHODOLOGY: Inflamed periapical tissues were obtained from patients at the time of endodontic surgical treatments and were cut into two pieces. After fixing with acetone or 4% paraformaldehyde in phosphate-buffered saline, 5-m-thick paraffin and cryostat sections were prepared. The paraffin sections of the inflamed tissues were evaluated histologically with haematoxylineosin stains. The specimens diagnosed as radicular cysts were then examined by immunostaining. Immunohistochemistry for iNOS and fluoresence microscopy for IFN-gamma using the cryostat sections were performed with a mixture of affinity purified human iNOS antiserum and human IFN-gamma monoclonal antibodies. RESULTS: The results revealed that iNOS-gamma producing cells localized adjacent to IFN-gamma-producing cells. In addition, some of iNOS-producing cells exhibited immunoreactive IFN-gamma. On the other hand, epithelial cells showed significant levels of iNOS production, but not IFN-gamma. CONCLUSIONS: The data would suggest the possibility that iNOS production could be precisely controlled by autocrine or paracrine effects of IFN-gamma producing cells in radicular cysts and might play a pivotal role in periapical lesions. These findings are consistent with a hypothesis suggesting that NO inhibitors could be used through the root canals as a pharmacological treatment for periapical lesions.

Adult↗

PubMed1999

Light regulates alternative splicing of hydroxypyruvate reductase in pumpkin.

Hydroxypyruvate reductase (HPR) is a leaf peroxisomal enzyme that functions in the glycolate pathway of photorespiration in plants. We have obtained two highly similar cDNAs for pumpkin HPR (HPR1 and HPR2). It has been revealed that two HPR mRNAs might be produced by alternative splicing from a single type of pre-mRNA. The HPR1 protein, but not the HPR2 protein, was found to have a targeting sequence into leaf peroxisomes at the C-terminus, suggesting that alternative splicing controls the subcellular localization of the two HPR proteins. Immunoblot analysis and subcellular fractionation experiments showed that HPR1 and HPR2 proteins are localized in leaf peroxisomes and the cytosol, respectively. Moreover, indirect fluorescence microscopy and analyses of transgenic tobacco cultured cells and Arabidopsis thaliana expressing fusion proteins with green fluorescent protein (GFP) revealed the different subcellular localizations of the two HPR proteins. Both mRNAs were induced developmentally and by light, but with quantitative differences. Almost equal amounts of the mRNAs were detected in pumpkin cotyledons grown in darkness, but treatment with light greatly enhanced the production of HPR2 mRNA. These findings indicate that light regulates alternative splicing of HPR mRNA, suggesting the presence of a novel mechanism of mRNA maturation, namely light-regulated alternative splicing, in higher plants.

Alcohol Oxidoreductases↗

PubMed1999

Changes of urinary dopamine excretion early after balloon mitral commissurotomy in mitral stenosis.

1. In order to investigate the changes of reduced urinary free dopamine excretion (uDA) in heart failure, 15 patients with symptomatic mitral stenosis were investigated on their uDA, endogenous creatinine (Cr) clearance, urinary excretion of sodium (UNaV), fractional excretion of sodium (FENa), plasma noradrenaline (pNA) and plasma L-dopa concentration before and early after percutaneous transvenous mitral commissurotomy (PTMC) by the clearance study. The delivery of L-dopa to renal proximal tubules (plasma L-dopa x Cr clearance), and the conversion ratio of plasma L-dopa to urinary dopamine in the kidney [uDA/(plasma L-dopa x Cr clearance)] were also estimated. 2. After successful PTMC, uDA, UNaV and FENa showed a significant but incomplete improvement and the changes of uDA were correlated positively with those of cardiac index (CI) (r = 0.665, P < 0.01), not with changes of pulmonary wedge pressure. While plasma L-dopa and plasma L-dopa x Cr clearance improved, uDA/(plasma L-dopa x Cr clearance) was not significantly changed early after PTMC. 3. From these results, it was suggested that reduced uDA tended to increase incompletely in relation with functional recovery of heart, and that increased plasma L-dopa and a delivery of L-dopa to renal proximal tubules have some positive role on urinary dopamine excretion, at least, early after PTMC.

Adult↗

PubMed1999

Effects of volitional lifestyle on rest-activity cycle in the aged.

The present study investigated the relationship among volitional lifestyle, activity and sleep in the aged. We selected 28 subjects over 65 years of age to survey volition to lifestyle. High-volitional group (14 Ss, mean age: 74.1 years, seven males and seven females) and low-volitional group (14 Ss, mean age: 73.0 years, seven males and seven females) were identified by the scale of self-confidence and the Philadelphia Geriatric Center morale scale. Wrist activities were monitored by Actigraph for 10 or 14 consecutive days. The subjects recorded sleep logs by themselves for those days. It was found that high volitional aged individuals had a relatively well structured sleep in comparison with low volitional aged individuals, and that most of them took a clock dependent habitual nap around 14.00 h. On the other hand, low volitional aged individuals had a relatively poor structured sleep, and took a nap time-dependently after 8 h from the morning rising time. These results suggest that high volitional aged individuals build a short nap into their well organized sleep-life habits.

Aged↗

PubMed1999

Topographic mapping of EEG spectral power and coherence in delta activity during the transition from wakefulness to sleep.

The present study examined the topographic characteristics in delta band activity during the transition from wakefulness to sleep, using topographic mapping of electroencephalogram (EEG) power and coherence corresponding to nine EEG stages. The dominant topographic components of delta band activity increased clearly from the vertex sharp-wave stage EEG stage 6) in the anterior-central area. Principal component maps revealed the scalp distribution of EEG. Delta activity in the sleep onset period were composed of two covariant components. One is a diffuse component widely distributed on the scalp and the other is a local component at the temporo-occipital area.

Adult↗

PubMed1999

Changes of amplitude and topographical characteristics of event-related potentials during the hypnagogic period.

In the previous study, during the vertex sharp wave period (hypnagogic EEG stage 4), negative components (N300, N550) were dominant at Fz and Cz in contrast to the positive component (P400) being prominent at the other areas, Pz, Oz, T5 and T6. There is no agreement regarding P400 properties during the hypnagogic period. In this study, using topographic mapping, we found that two negative components (N300, N550) and P400 independently increased their amplitude at the different areas of the scalp as arousal level lowered. The anterior negative components may reflect the information processing related to the K-complex. The P400 may reflect other activities different from the K-complex mechanism or P300 attention mechanisms.

Adult↗

PubMed1999

Effects of a daytime nap in the aged.

This study evaluated the effects of the daytime nap on performance, mood and physiological measures in aged individuals Participants were six healthy aged persons (M=72.2 years old) who habitually napped in the afternoon three or more times a week. They participated under two conditions with an interval of 1 week. In the nap condition, the subjects went to bed at 13:00 h and slept for 30 min. In the rest condition, they just watched television. In both conditions, electroencephalogram (EEG), blood pressure, mood and performance were measured before and after a nap or rest. The daytime nap improved performance, decreased subjective sleepiness and fatigue, and attenuated EEG alpha band activity. Moreover, following a nap diastolic blood pressure significantly decreased. These findings suggest that a habitual daytime nap helps aged individuals to maintain their daytime physiological, psychological and behavioral arousal at an adequate level.

Affect↗