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Biomedical subjects

H Yano

Publications and source records attributed to H Yano.

At least 181 records · Page 10Linked to original sources
PubMed1998

Phase-dependent electromyographic activity of the lower-limb muscles of a patient with clinically complete spinal cord injury during orthotic gait.

We examined the lower-limb electromyographic (EMG) activity from a patient with clinically complete spinal cord injury during orthotic gait. A newly developed gait orthosis was used to obtain bipedal locomotion. The surface EMG data during the gait together with the biomechanical variables were collected by way of a radio EMG system. A cyclic EMG activation pattern corresponding to the gait cycles were observed in each of the paralyzed lower-limb muscles during the orthotic gait. Although the EMG activation did not seem to contribute toward generating the gait, it showed some similarities to that of the infant stepping or immature gait. These results might be regarded as one of the indirect pieces of evidence that suggest the existence of a spinally originating motor mechanism underlying human locomotion.

Adult↗
PubMed1998

Differences in stretch reflex responses of elbow flexor muscles during shortening, lengthening and isometric contractions.

Stretch reflexes were evoked in elbow flexor muscles undergoing three different muscle contractions, i.e. isotonic shortening (SHO) and lengthening (LEN), and isometric (ISO) contractions. The intermuscle relationships for the magnitude of the stretch reflex component in the eletromyographic (EMG) activities of two main elbow flexor muscles, i.e. the biceps brachii (BB) and the brachioradialis (BRD), were compared among the three types of contractions. The subjects were requested to move their forearms sinusoidally (0.1 Hz) against a constant pre-load between elbow joint angles of 10 degrees (0 degrees = full extension) and 80 degrees during SHO and LEN, and to keep an angle of 45 degrees during the ISO. The perturbations were applied at the elbow angle of 45 degrees in pseudo-random order. The EMG signals were rectified and averaged over a period of 100 ms before and 400 ms after the onset of the perturbation 40-50 times. From the ensemble averaged EMG waveform, the background activity (BGA), short (20-50 ms) and long latency (M2, 50-80, M3, 80-100 ms) reflex and voluntary activity (100-150 ms) components were measured. The results showed that both BGA and reflex EMG activity of the two elbow flexor muscles were markedly decreased during the lengthening contraction compared to the SHO and ISO contractions. Furthermore, the changes of reflex EMG components in the BRD muscle were more pronounced than those in the BB muscle, i.e. the ratios of M2 and M3 magnitudes between BRD and BB (BRD:BB) were significantly reduced during the LEN contractions. These results would suggest that the gain of long latency stretch reflex EMG activities in synergistic muscles might be modulated independently according to the model of muscle contraction.

Adult↗
PubMed1998

Prognostic significance of febrile episodes in lung cancer patients receiving chemotherapy.

The prognostic significance of neutropenic fever in lung cancer patients receiving chemotherapy with or without radiotherapy was investigated. Male patients and patients with squamous cell lung cancer had a higher incidence of febrile episodes than female patients and patients with other cell types, but the differences were not significant. Patients with a poor performance status had a significantly higher incidence of febrile episodes. An indwelling central venous catheter was an important risk factor for febrile episodes, indicating that bacteremia was one of the major causes of fever. The median survival time of the patients who developed febrile episodes during chemotherapy was significantly shorter than that of patients without fever (6.1 vs 12.0 months), whether or not cases of early death within 3 months were excluded (8.9 vs 13.1 months). The prevention of infectious complications during anticancer treatment by the use of rh G-CSF and the early initiation of antimicrobial chemotherapy, although the results are inconclusive, may be worthwhile.

Aged↗
PubMed1998

Mass screening for neuroblastoma at 6 months of age: difficult to justify.

BACKGROUND/PURPOSE: A statistical analysis of the mass screening for neuroblastoma in Japan based on a population study rarely has been reported. This study aims to evaluate retrospectively the effectiveness of mass screening at 6 months of age using the available population data. METHODS: The data on the neuroblastoma cases registered by the Committee for Pediatric Solid Malignant Tumors in the Kyushu area were analyzed based on both screened and unscreened populations in the Kyushu area. RESULTS: From 1988 to 1992, the cumulative incidence of neuroblastoma in children less than 5 years of age was 82 in 484,599 for screened children, and 11 in 92,966 for unscreened children, respectively. Fourteen of the 82 screened patients had negative findings at 6 months of age (MS-negative cases). No significant difference was observed in the cumulative mortality rates from neuroblastoma in children younger than 5 years of age between the screened children and the unscreened children. Six of seven patients who died among the screened children were MS-negative cases with stage III or IV disease. In addition, no significant difference was found in the cumulative mortality rates from the neuroblastoma cases in patients less than 5 years of age between the children screened from 1988 to 1992 (7 of 484,599) and all children from 1980 to 1984 (14 of 668,084). CONCLUSIONS: These findings suggests that the majority of the patients detected by mass screening had a favorable prognosis, and, mass screening in Japan for children less than 6 months of age was not observed to reduce the incidence and mortality from neuroblastoma. Therefore, mass screening at 6 months of age was not found to improve substantially the prognosis of patients with unfavorable neuroblastoma identified over 1 year of age, which is the primary purpose of such mass screening for neuroblastoma.

Evaluation Studies as Topic↗
PubMed1998

Immunohistochemical measurement of cell proliferation as replicative DNA synthesis in the liver of male Fischer 344 rats following a single exposure to nongenotoxic hepatocarcinogens and noncarcinogens.

We aimed to modify an in vivo/in vitro hepatocyte replicative DNA synthesis (RDS) test using autoradiography of [3H]methylthymidine (3HTdR) into a nonradioactive in vivo version by applying 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry. The effects of 12 nongenotoxic hepatocarcinogens and 4 noncarcinogens on RDS induction and histological changes in the liver of male Fischer 344 (F344) rats were investigated 24 or 48 hrs after a single oral administration at diverse dose levels. A statistically significant, dose-related elevation in BrdU labeling indices (LI) was obtained for all of the 12 nongenotoxic hepatocarcinogens with only one exception of D,L-ethionine at relatively lower dose levels. No increase was observed in LI for any of the four noncarcinogens examined. From the results of histopathological evaluation, the increase in hepatocyte proliferation by carbon tetrachloride (CCl4), chloroform (CHCl3), and thioacetamide (TAA) was confirmed to be a regenerative liver response following cytotoxicity. Conversely, safrole, tannic acid, and urethane yet hepatotoxicants did not show inflammatory reaction or necrosis under the condition of the present study, and hence their mode of action by which they induce proliferative response was not obvious. The results of this study showed that the in vivo version of RDS test efficiently discriminated nongenotoxic hepatocarcinogens from noncarcinogens, while it did not well clarify the induction mode of cell proliferation.

Animals↗
PubMed1998

Inhibition by transforming growth factor (34-43)-alpha, a TGF-alpha antagonist, of gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats.

The effect of prolonged administration of transforming growth factor (34-43)-alpha, an antagonist of TGF-alpha, on gastric carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and on the labelling and apoptotic indices and TGF-alpha immunoreactivity of gastric mucosa and gastric cancers was examined in Wistar rats. The rats received intraperitoneal injections of 10 or 20 microg kg(-1) body weight of TGF(34-43)-alpha every other day after oral treatment with MNNG for 25 weeks. Long-term administration of TGF(34-43)-alpha at both doses significantly reduced the incidence of gastric cancers at the end of the experiment in week 52. However, TGF(34-43)-alpha had no significant effect on the number, histological type or depth of involvement of gastric cancers. Administration of TGF(34-43)-alpha also significantly decreased the bromodeoxyuridine labelling index and TGF-alpha immunoreactivity, and significantly increased the apoptotic index of antral mucosa and gastric cancers. These findings indicate that TGF(34-43)-alpha inhibits gastric carcinogenesis, and that its effects are mediated through decreased cell proliferation and TGF-alpha immunoreactivity and increased apoptosis induction in the gastric cancers.

Adenocarcinoma↗
PubMed1998

Suppression by pravastatin, an inhibitor of p21ras isoprenylation, of hepatocarcinogenesis induced by N-nitrosomorpholine in Sprague-Dawley rats.

The effect of pravastatin, an inhibitor of p21ras isoprenylation, on hepatocarcinogenesis induced by N-nitrosomorpholine and on p21ras isoprenylation were investigated in male Sprague-Dawley rats. Rats received i.p. injections of pravastatin (10 and 20 mg kg(-1) body weight) every other day and, from the beginning of the experiment, were given drinking water containing N-nitrosomorpholine for 8 weeks. Visible white nodules and hepatic lesions staining positively for gamma-glutamyl transpeptidase or glutathione-S-transferase, placental type, were examined macroscopically or histochemically. In week 15, pravastatin at both dosages significantly reduced the incidence, number and volume of visible white nodules. Quantitative histological analysis also showed that prolonged administration of pravastatin at both dosages resulted in significant reductions in the number and percentage area of hepatic lesions positive for gamma-glutamyl transpeptidase and glutathione-S-transferase, placental type. Administration of pravastatin also significantly decreased the amount of membrane-associated p21ras in the tumour and the labelling index of neoplastic nodules and increased the apoptoic indices of neoplastic nodules. These findings indicate that pravastatin suppresses hepatocarcinogenesis and suggest that this effect might be related to pravastatin's inhibition of p21ras isoprenylation and its subsequent inhibition of cell proliferation and induction of apoptosis in neoplastic lesions.

Animals↗
PubMed1998

Fermentation of soybean meal with Aspergillus usamii reduces phosphorus excretion in chicks.

Fermentation with Aspergillus usamii almost completely degrades phytate phosphorus in soybean meal. Phosphorus excretion was investigated in chicks fed a fermented soybean meal-based diet. Thirty chicks were fed one of three experimental diets; a control soybean meal-based diet (total phosphorus, 5.2 g/kg; nonphytate phosphorus, 2.3 g/kg), a control soybean meal-based diet with added inorganic phosphorus (total phosphorus, 7.1 g/kg; nonphytate phosphorus, 4.0 g/kg), or a fermented soybean meal-based diet without supplemental inorganic phosphorus (total phosphorus, 5.8 g/kg; nonphytate phosphorus, 3.9 g/kg) for 4 wk. Body weight gain, the amount of retained phosphorus, and femoral phosphorus content were lower in the control group than in the phosphorus-supplied group and the fermented soybean meal group. The latter two groups showed similar body weight gain and femoral phosphorus content. On the other hand, phosphorus excretion was markedly more in the phosphorus-supplied group than in the other groups. As a result, phosphorus retention (percentage of intake) was lower in the phosphorus-supplied group than in the fermented soybean meal group. In conclusion, fermentation improved phosphorus bioavailability in soybean meal and supplemental inorganic phosphorus was not necessary for the fermented soybean meal-based diet, which remarkably reduced phosphorus excretion.

Animals↗
PubMed1998

Increased proliferative activity of osteoblasts in congenital hemifacial hypertrophy.

Congenital hemifacial hypertrophy is expressed in facial asymmetry resulting from unilateral overgrowth. We examined proliferative activity of primary cultured osteoblasts taken from the hemifacial hypertrophic side of an 18-year-old woman compared with the normal side. Both fetal calf serum and basic fibroblast growth factor stimulated osteoblast DNA synthesis, and cultured osteoblast proliferation was markedly increased in the hypertrophic side. Neutralizing antibody against basic fibroblast growth factor was effective to partially block fetal calf serum-induced DNA synthesis. These results suggest that fibroblast growth factor and its receptor signal transduction axis may be selectively involved in affected osteoblasts, leading to progression of congenital hemifacial hypertrophy.

Adolescent↗
PubMed1998

Immunological quantitation of DT-diaphorase in carcinoma cell lines and clinical colon cancers: advanced tumors express greater levels of DT-diaphorase.

NAD(P)H:quinone oxidoreductase (DT-diaphorase; DTD) plays a major role in activating mitomycin C (MMC) in human colon and gastric carcinoma cell lines. Thus, measurement of DTD in clinical tumor samples could be beneficial in designing adjuvant chemotherapy. We explored immunological quantitation of DTD protein using a monoclonal antibody against DTD, demonstrating a close correlation between protein expression and enzyme activity of DTD in colon and gastric carcinoma cell lines and in colorectal tumor samples. This indicates that such immunoblot analysis is a simple alternative method for quantitating DTD in clinically excised samples. In most colorectal tumor samples, the tumors expressed larger amounts of DTD than did the peripheral normal tissues, suggesting a selective toxicity of MMC toward tumor cells. Also tumors with nodal metastases showed significantly higher DTD levels than did tumors without metastasis. These results raise the possibility that DTD expression is related to tumorigenesis and malignant progression of colorectal tumors. Measurement of DTD by the immunological method described here could be beneficial in designing a rational adjuvant chemotherapy with MMC.

Adenocarcinoma↗
PubMed1998

Antimicrobial effects of electrolytic products of sodium chloride--comparative evaluation with sodium hypochlorite solution and efficacy in handwashing.

We examined the in vitro bactericidal effects and efficacy on handwashing of water containing electrolytic products of sodium chloride (electrolytic water). The electrolytic water, whose pH and concentration of free residual chlorine were 6.7-6.9 and 20-22 ppm, respectively, showed equal reduction of both Staphylococcus aureus and Escherichia coli to dilution of commercially available sodium hypochlorite containing 60 ppm of free residual chlorine. This bactericidal effect was calculated to be due to hypochlorous acid, based on the pH and the amount of chlorine in solution. Handwashing with the electrolytic water reduced the numbers of S. aureus on hands by 1/10(2), while running water and 0.2% benzalkonium chloride with 80% ethanol gave a 1/10 and 1/10(5) reduction, respectively. We conclude that electrolytic water might be applicable for handwashing in place of running water.

Chlorine↗
PubMed1998

Retroperitoneal fibrosis with perinuclear antineutrophil cytoplasmic antibodies and a longitudinally extended periaortic soft-tissue structure on CT.

A 63-year-old woman showed positive perinuclear antineutrophil cytoplasmic antibodies (pANCA) and presented with an interesting CT finding of a periaortic soft-tissue structure seen as a rind of tissue surrounding the aorta, extending longitudinally from descending thoracic aorta to bilateral common iliac arteries which was compatible with an early stage of retroperitoneal fibrosis (RPF). Both pANCA titers and a periaortic mass volume were reduced following corticosteroid treatment. No cases of RPF with a periaortic mass associated with pANCA have been described. Our findings of RPF with pANCA positivity may enlarge the groups of ANCA-associated diseases.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1998

Pituitary-directed leukemia inhibitory factor transgene causes Cushing's syndrome: neuro-immune-endocrine modulation of pituitary development.

Leukemia inhibitory factor (LIF) regulates the mature hypothalamic-pituitary-adrenal axis in vivo. In vitro, LIF determines corticotroph cell proliferation and induces POMC transcription. To explore LIF action on pituitary development, transgenic mice expressing LIF driven by the pituitary glycoprotein hormone alpha-subunit (alphaGSU) promoter were generated. Transgenic mice exhibited dwarfism with low IGF-I (29 +/- 9 ng/ml vs. wild type (WT) 137 +/- 16 ng/ml; P < 0.001), hypogonadism with low FSH (0.04 +/- 0.023 ng/ml vs. WT 0.63 +/- 0.18 ng/ml; P < 0.001), and Cushingoid features of thin skin and truncal obesity with elevated cortisol levels (86 +/- 22 ng/ml vs. WT 50 +/- 14 ng/ml; P = 0.002). Their pituitary glands showed corticotroph hyperplasia, striking somatotroph and gonadotroph hypoplasia, and multiple Rathke-like cysts lined by ciliated cells. LIF, overexpressed in Rathke's pouch at embryonal day 10, diverts the differentiation stream of hormone-secreting cells toward the corticotroph lineage and ciliated nasopharyngeal-like epithelium. Thus, inappropriate expression of LIF, a neuro-immune interfacing cytokine, plays a key role in the terminal differentiation events of pituitary development and mature pituitary function.

Animals↗
PubMed1998

The interaction between vitamin A and thiazolidinedione on bovine adipocyte differentiation in primary culture.

We studied the effects of a thiazolidinedione (T-174) and retinoids on adipocyte differentiation in beef cattle. Stromal-vascular (SV) cells containing preadipocytes were prepared from perirenal adipose tissue of 21-mo-old Japanese Black steers. After confluence, these cells were cultured in 25 microM T-174, which is a specific ligand for an adipogenesis stimulating nuclear receptor (i.e., gamma subtype of peroxisome proliferator-activated receptor [PPARgamma]), with 1 microM all-trans retinoic acid (RA) or .4 to 40 microg/100 mL of retinol for 10 to 14 d. The number of cells accumulating lipid droplets was counted as morphologically differentiated adipocytes, and the activity of glycerol-3-phosphate dehydrogenase (GPDH), a biochemical index for the differentiation, was determined. The number of lipid-laden cells and GPDH activity were increased by the addition of T-174. All-trans retinoic acid completely blocked the stimulative action of T-174. The addition of retinol also decreased the number of lipid-laden cells and GPDH activity in a dose-dependent manner. These results showed that the thiazolidinedione stimulated adipocyte differentiation and the retinoids blocked the adipogenesis induced by the thiazolidinedione in primary culture of bovine SV cells. Peroxisome proliferator-activated receptor gamma may play an important role in adipocyte differentiation, and retinoids may interfere with the action of PPARgamma in cattle.

Adipocytes↗
PubMed1998

Fermentation of soybean flour with Aspergillus usamii improves availabilities of zinc and iron in rats.

Soybean flour was fermented with Aspergillus usamii to improve the availabilities of dietary zinc and iron through the degradation of phytate. Three kinds of experimental diets that differed in protein sources were prepared: one consisting of 40% fermented soybean flour (RS diet), one consisting of 40% fermented soybean flour (FS diet), and one consisting of 20% regular soybean flour and 20% fermented soybean flour (RF diet). Zinc solubilities in the upper and the lower segments of the small intestine were higher in rats fed the FS diet than in rats fed the RS diet. The FS group showed higher solubility of iron in the lower small intestine than the RS group did. Zinc concentrations in the femur and plasma and iron concentrations in the liver and plasma were higher in the FS group than in the RS group. These results suggested that the fermentation of soybean flour improved the availabilities of dietary zinc and iron, which may be induced by increasing the solubilities of these minerals in the small intestine through the reduction of phytate content. Femoral and plasma zinc concentrations in the RF group were higher than in the RS group, but lower than in the FS group. No difference was noted in liver and plasma iron concentrations between the RF group and the FS group. Although phytase activity in FS degrades phytate in the RF diet, higher activity may be needed to degrade phytate completely.

Animals↗
PubMed1998

Why do antimicrobial agents become ineffectual?

Antibiotic resistance has evolved over the past 50 years from a merely microbiological curiosity to a serious medical problem in hospitals all over the world. Resistance has been reported in almost all species of gram-positive and -negative bacteria to various classes of antibiotics including recently developed ones. Bacteria acquire resistance by reducing permeability and intracellular accumulation, by alteration of targets of antibiotic action, and by enzymatic modification of antibiotics. Inappropriate use of an antibiotic selects resistant strains much more frequently. Once resistant bacteria has emerged, the resistance can be transferred to other bacteria by various mechanisms, resulting in multiresistant strains. MRSA is one of the typical multiresistant nosocomial pathogens. A study of the PFGE pattern of endonuclease-digested chromosomal DNA showed that MRSA of a few clones were disseminated among newborns in the NICU of a Japanese hospital. In this regard, it is important to choose appropriate antibiotics and then after some time, to change to other classes to reduce the selection of resistant strains. Since the development of epoch-making new antibiotics is not expected in the near future, it has become very important to use existing antibiotics prudently based on mechanisms of antibiotic action and bacterial resistance. Control of nosocomial infection is also very important to reduce further spread of resistant bacteria.

Cross Infection↗
PubMed1998

[Clinical features in patients with delayed endolymphatic hydrops].

We report clinical features in patients with delayed endolymphatic hydrops (DEH) with juvenile unilateral deafness. Among 23 patients with DEH, 15 cases were diagnosed as ipsilateral DEH and 8 cases as contralateral DEH. The distribution of onset age showed two peaks at ages of < 30 years and > 40 years. In 80% of the ipsilateral DEH cases, the onset of episodic vertigo was at younger ages. On the other hand, in 75% of the contralateral DEH cases, the onset of fluctuation hearing loss of the contralateral ear was at older ages. Ispilateral DEH and Meniere's disease may show different pathophysiologies. The incidence of dominant negative summating potential in the better-hearing ear was 20% in the ispilateral DEH cases and 60% in the contralateral DEH cases. It is suggested that endolymphatic hydrops is in the better-hearing ear of contralateral DEH.

Adult↗