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Biomedical subjects

K Higashi

Publications and source records attributed to K Higashi.

At least 109 records · Page 6Linked to original sources
PubMed1997

Remnant-like very-low-density lipoprotein isolated from hypertriglyceridemic patients by immunoaffinity chromatography suppressed 3-hydroxy-3-methylglutaryl coenzyme A activity of cultured human skin fibroblasts.

It has been previously reported that VLDL unbound to monoclonal antibody against apoB-100 was rich in apoE, thus resembling remnant particles (J Lipid Res, 1993:33;369-380). In the current study, we have further analyzed the unbound VLDL fraction in plasma from hypertriglyceridemic patients using a mixture of monoclonal antibodies against apoB-100 and apoA-1. The unbound VLDL isolated from the plasma of hypertriglyceridemic patients was found to be rich in apoE, apoB-48, and triglyceride compared with the bound VLDL. Furthermore, these unbound VLDL, but not bound VLDL, significantly suppressed HMG CoA reductase activity of cultured human skin fibroblasts (-20 to -25%, P = 0.0022). The degree of suppression is significantly correlated with the apoE content of unbound VLDL (r = -0.769, P < 0.05). Unbound VLDL failed to suppress the activity of HMG CoA reductase of LDL receptor negative fibroblasts. These observations indicate a potential atherogenicity of remnant-like unbound VLDL by delivering more cholesterol through the LDL receptor dependent pathway with apoE as a ligand. In conclusion, this new immunoaffinity chromatography system is a useful method for directly quantifying atherogenic remnants in plasma.

Adult↗
PubMed1997

Percutaneous laser discectomy: MR findings within the first 24 hours after treatment and their relationship to clinical outcome.

OBJECTIVE: The purpose of this study was to evaluate the early MR appearances of the intervertebral disc obtained within 24 h after percutaneous laser discectomy and to determine if a correlation exists between the MR images and the clinical outcome. SUBJECTS AND METHODS: Twenty-nine discs in 26 patients with contained lumbar disc herniation treated by laser were included. Laser intervention was performed using Ho:YAG laser system. The results were quantitatively analysed by measuring areal changes of the herniated mass on axial T1-weighted images and signal changes within the disc on sagittal T2-weighted images. Clinical outcomes were evaluated according to Japanese Orthopaedic Association score (JOA score), and recovery rates based on JOA score immediately and 1 year after treatment were calculated. RESULTS: The recovery rate immediately after treatment was 53.1%, and increasing to 64.6% 1 year later. The size of the disc herniation ranged from 7% to 55% of the axial cross-section of the spinal canal pre-operatively and no significant changes were noted postoperatively. Also no correlation was found between the pre-operative herniation size and the recovery rate. The signal changes within the disc increased significantly after treatment, but no correlation was present between the signal changes and the recovery rate. In five patients, soft-tissue changes along the laser tract were well demonstrated on MR imaging. CONCLUSION: Although immediate postoperative MR imaging shows early tissue changes induced by laser, our study has not proven that immediate postoperative MR imaging could predict the clinical outcome after percutaneous laser discectomy.

Adolescent↗
PubMed1997

An extracellular insoluble inhibitor of cysteine proteinases in cell cultures and seeds of carrot.

An 18 kDa extracellular insoluble protein (EIP18) was found previously in amorphous particles suspended in the culture medium and in the interspaces of cell clusters of carrot (Daucus carota L.) callus, as well as in the extracellular spaces of carrot seeds, being located both in the embryo and at the inner edge of the endosperm. We purified EIP18 by washing the amorphous particles with the mixture of Triton X-100, NaCl and ethylenediaminetetraacetic acid (EDTA). We determined several partial amino acid sequences, and then we cloned and sequenced a cDNA for EIP18. EIP18 was found to consist of 133 amino acid residues that included a signal sequence, but it did not contain cysteine, sites for N-linked glycosylation or hydrophobic regions. Since its sequence was found to be homologous to that of inhibitors of cysteine proteinases, namely cystatins, EIP18 was renamed EICC (extracellular insoluble cystatin of carrot). EICC expressed in yeast was also found in an insoluble form in yeast cell walls. EICC prepared from the culture medium of carrot cells inhibited commercial cysteine proteinases and a proteinase extracted from germinating carrot seeds. The expression of the gene for EICC was detected in developing seeds, and the level of its transcript was markedly enhanced upon treatment of somatic embryos with abscisic acid.

Amino Acid Sequence↗
PubMed1997

Differential inhibition of epidermal growth factor signaling pathways in rat hepatocytes by long-term ethanol treatment.

BACKGROUND & AIMS: Long-term ethanol intake suppresses liver regeneration in vivo and ethanol interferes with epidermal growth factor (EGF)-induced DNA synthesis in vitro. Therefore, the effects of long-term ethanol treatment on EGF-activated signaling reactions in rat hepatocytes were investigated. METHODS: Hepatocytes from long-term ethanol-fed rats and pair-fed controls were stimulated with EGF (0.5-20 nmol/L) for 15-120 seconds. Tyrosine phosphorylation of EGF receptor (EGFR), Shc, and phospholipase-C gamma1 (PLC gamma), and growth factor receptor binding protein 2 (Grb2) coprecipitation with EGFR and Shc were analyzed by Western blotting. RESULTS: EGFR autophosphorylation was suppressed at all EGF concentrations in ethanol-fed cells compared with pair-fed cells, without significant differences in total EGFR protein or EGFR tyrosine kinase activity detected in cell lysates, suggesting that intracellular factors suppressed EGFR function. EGF-induced PLC gamma tyrosine phosphorylation and inositol 1,4,5-trisphosphate (InsP3) formation were suppressed, but cytosolic [Ca2+]c elevation was little affected, indicating enhanced InsP3-mediated intracellular Ca2+ release in ethanol-fed cells. Grb2 binding to EGFR was suppressed, but EGF-induced Shc tyrosine phosphorylation and Grb2 association with Shc were not significantly decreased. CONCLUSIONS: Long-term ethanol feeding suppressed EGF-induced receptor autophosphorylation in rat hepatocytes with differential inhibition of downstream signaling processes mediated by PLC gamma, Shc, and Grb2. Altered patterns of downstream signals emanating from EGFR may contribute to deficient liver regeneration in chronic alcoholism.

Animals↗
PubMed1997

Olive oil increases the magnitude of postprandial chylomicron remnants compared to milk fat and safflower oil.

OBJECTIVE: The acute effects of olive oil, milk fat and safflower oil on postprandial lipemia and remnant lipoprotein metabolism were investigated. METHODS: Eight Healthy male volunteers randomly underwent three types of oral fat-vitamin A loading tests. The test drink was a mixture of retinyl palmitate (RP)(50,000 IU of aqueous vitamin A/m2 body surface area) and one of the three types of oils (40 g of fat/m2 body surface area): olive oil (70.7% oleic acid of total fatty acids); milk fat (69.3% saturated fatty acid); safflower oil (74.2% linoleic acid). RESULTS: Olive oil significantly increased plasma triacylglycerol and RP concentrations 4 hours after fat loading, as compared to other fats. Increases of remnant like particle concentrations were higher after olive oil than after the other two fats. CONCLUSION: These results show that olive oil increases the magnitude of postprandial chylomicrons and chylomicron remnants compared to milk fat and safflower oil.

Adult↗
PubMed1997

The role of endothelin-1 in epidermal hyperpigmentation and signaling mechanisms of mitogenesis and melanogenesis.

The paracrine linkage of endothelins (ET) between keratinocytes and melanocytes suggested that ETs are intrinsic mediators for human melanocytes in UVB-induced pigmentation. In this study, the role of ET-1 in the epidermal hyperpigmentation was investigated in vivo and in vitro. The addition of 10 nM ET-1 induced a H-7 (10 microM) suppressible-increase in tyrosinase activity in cultured human melanocytes and was accompanied by elevated levels of tyrosinase and tyrosinase-related protein-1 mRNA expression as shown by Northern blotting. Analysis of signaling mechanisms leading to tyrosinase activation demonstrated the involvements of quick translocation of PKC, the H-7 (10 microM) suppressible-phosphorylation of the threonine residue of several proteins, and highly elevated level of cyclic AMP (4-fold over control). Reverse transcription polymerase chain reaction (RT-PCR) of RNA isolated from the epidermis of human skin exposed to UVB revealed that UVB irradiation with a dose of 2 MED caused a significant increase in the expressions of ET-1, IL-1 alpha, and tyrosinase mRNA signals 5 days after irradiation. The involvement of ET-1 in UVB-pigmentation was also corroborated by the experiments that the extracts of M. Chamomilla, which can act as an antagonist for ET-receptor binding-mediated signaling but has no inhibitory effect on tyrosinase activity in culture, had a significant inhibitory effect on UVB-induced pigmentation in vivo when daily applied immediately after UVB exposure to human skin. These findings suggest that ET-1 is an important mediator in the epidermis for UVB-induced pigmentation in vivo.

Cell Division↗
PubMed1997

Beneficial effects of alcohol withdrawal on LDL particle size distribution and oxidative susceptibility in subjects with alcohol-induced hypertriglyceridemia.

LDL subclass pattern B, reported to have a higher prevalence in hypertriglyceridemics (HTGs), is considered to be associated with an increased risk for coronary artery disease, and the small dense LDL characteristic of this pattern is susceptible to oxidative modification. Alcohol is considered one of the most frequent causes of increases in plasma triglyceride (TG) levels. We investigated the effects of alcohol withdrawal on LDL subclass distribution and oxidizability in drinkers with different plasma TG levels. Thirty-seven male subjects with relatively heavy alcohol-consumption habits were divided into four groups; normotriglyceridemic (NTG)/withdrawal (n = 11), NTG/control (n = 8), hypertriglyceridemic (HTG)/withdrawal (n = 10), and HTG/control (n = 8). Both withdrawal groups abstained form alcohol for 4 weeks, while the control subjects maintained their usual intake of alcohol. Peak LDL particle diameter (PPD) was smaller in the combined HTG groups than in the combined NTG groups before abstinence, although PPD increased significantly (P < .01) from 25.5 to 26.1 nm in the HTG/withdrawal group. Before abstinence, lag times preceding LDL oxidation in the combined HTG groups were shorter than in the combined NTG groups; after withdrawal, lag time was prolonged significantly (P < .01) from 49.9 to 57.3 minutes in the HTG-withdrawal group. No significant changes in PPD and lag time were observed in the other three groups. Significant correlations (P < .05) were observed between the change (delta) in the lag time and delta TG and between delta lag time and delta PPD. We conclude that in alcohol-induced HTG subjects, alcohol withdrawal has beneficial effects on the LDL profile by shifting the particle size from smaller to larger and decreasing its susceptibility to oxidation.

Adult↗
PubMed1997

In vitro skin penetration and degradation of enkephalin, elcatonin and insulin.

The work described in this paper was designed to evaluate the relevance of in vitro skin penetration studies of peptides across rat skin. The apparent penetration of three peptides, enkephalin, elcatonin and insulin, in the presence of enhancers was not seen in the in vitro method using Franz diffusion cells. However, when a protease inhibitor was mixed in the receptor fluid, the penetration of enkephalin and insulin was observed. Although insulin penetrated in the presence of enhancers, the penetration was extremely small in quantity and the cumulative amount did not increase with time. When the degradation of peptides in the receptor fluid of Franz cell was estimated, these peptides, especially enkephalin and insulin, were rapidly hydrolyzed and were almost completely lost within 3 h in the absence of an inhibitor, while elcatonin was slowly degraded. The addition of protease inhibitors, such as gabexate (20 mM), camostat (20 mM) or bile salt (taurocholate and deoxycholate, 10 mM), to the receptor fluid inhibited the degradation to a considerable extent, with the first-order rate constants decreased to one-tenth compared with the constants without inhibitors. From the inhibitory study using specific inhibitors, it was clarified that enkephalin and elcatonin were mainly hydrolyzed by aminopeptidases, endopeptidases and serine proteases in the viable skin. Consequently, the results obtained from the in vitro penetration studies without inhibitors did not reflect reliable penetration data. Thus, effective protease inhibitor(s) should be used to obtain the data corresponding to the in vivo transdermal experiment. This methodology will provide a means to eliminate the confounding effect of metabolism in permeation experiments.

Aminopeptidases↗
PubMed1997

Pulmonary fibrosis associated with polymyalgia rheumatica.

Polymyalgia rheumatica (PMR) and exacerbated pulmonary fibrosis presented concurrently in a 69-year-old woman with a 5-year history of idiopathic interstitial pneumonia. The radiographic and histological examinations suggested usual interstitial pneumonia (UIP) as a more likely diagnosis. Corticosteroid therapy resulted in relief of the patient's muscle symptoms and improvement in the functional and radiographical signs of the pulmonary fibrosis. The final diagnosis was pulmonary fibrosis associated with PMR, because PMR is believed to be one of the causes contributing to interstitial lung diseases.

Aged↗
PubMed1997

Increases of thrombomodulin activity and antigen level on human umbilical vein endothelial cells treated with asbestos and man-made mineral fibers.

The potential influences of crocidolite asbestos fibers and man made mineral fibers (potassium titanate whisker and magnesium sulfate whisker) on a procoagulant system of human umbilical vein-endothelial cells (HUVECs) were investigated by measuring the activity and antigen level of thrombomodulin (TM) on the cell surface. Statistically significant increases in both the TM activity and TM antigen level were observed on HUVECs treated with crocidolite asbestos fibers for 48 h and 72 h compared to untreated cells at low concentrations of the fibers which showed no sign of a cytotoxic effect on the cells. An extensive increase in both the TM activity and TM antigen level was also observed on HUVECs treated with potassium titanate whisker or magnesium sulfate whisker for 48 h and 72 h. A statistical analysis revealed that these fibers had almost the same effects on the increases in both TM activity and the TM antigen level of HUVECs treated with the fibers for 48 h and 72 h, but a treatment of magnesium sulfate whisker at more than 1.25 micrograms/ml for 24 h was slightly more effective in increasing TM activity on HUVECs compared to other fibers (p < 0.05). The [3H]leucine incorporation in HUVECs increased when the cells were treated with crocidolite asbestos or man-made mineral fibers (MMMFs), indicating that the increases in TM activity and the TM antigen level on HUVECs directly exposed to those fibers may not reflect the sole induction of anticoagulant activities, but the general cell damage induced by the fibers.

Air Pollutants, Occupational↗
PubMed1997

Primary Sjögren's syndrome associated with hyaline-vascular type of Castleman's disease and autoimmune idiopathic thrombocytopenia.

We describe a case of primary Sjögren's syndrome complicated by hyaline-vascular type of Castleman's disease and autoimmune idiopathic thrombocytopenia. This type of Castleman's disease was diagnosed by biopsy of a right axillary lymph node 7 years after the onset of Sjögren's syndrome. The specimen showed small hyaline-vascular lymphoid follicles and interfollicular capillary proliferation. Serum IL-6 was slightly increased, but systemic manifestations, such as fever or weight loss, were not present. Hyaline-vascular type of Castleman's disease should be considered a lymphoproliferative disorder associated with Sjögren's syndrome.

Biopsy↗
PubMed1997

[Improvement of inter-assay for the standardization of PT and TT--clinical significance of local standardization method].

We performed a nationwide Inter-assay including 112 laboratories for the standardization of prothrombin time (PT) and thrombotest (TT). The data were expressed as seconds, percentile and INR. INR was expressed by 2 methods; Method I (conventional method): INR was expressed using each ISI assigned for reagent or reagent-instrument at the respective laboratories and Method II (local standardization method): INR was expressed using each reference curve created with INR assigned standard plasmas at the respective laboratories. (1) Sample distribution of PT as well as TT was the smallest with the data expressed by Method II followed by Method I and then by percentile. The data expressed by seconds was widely distributed and not useful for the standardization of PT and TT. (2) Even the sample distribution obtained by Method II was dependent on the different ISI of the reagents, as it was found that the larger the ISI of the reagents, the wider the distribution of data. (3) The difference between PT and TT of each test plasma was analysed by t-test. It was found that the difference was insignificant when both data were expressed by Method II, but significant when expressed by Method I, suggesting that PT and TT were interchangeable with the use of Method II. (4) Sample distribution of percentile expression and INR with the use of method II was compared. It was revealed that the sample distribution of INR was smaller than that of percentile. It was concluded that INR expressed by the local standardization method was most useful for the standardization of PT and TT.

Humans↗
PubMed1997

Incrustation and uptake of skeletal imaging agent in transitional cell carcinoma.

We present a case of transitional cell carcinoma of the bladder visualized by 99mTc-HMDP bone scintigraphy and suggest possible uptake mechanisms. Pelvic CT demonstrated a sessile bladder tumor with punctate and curvilinear calcifications on the surface areas (incrustation). Technetium-99m-HMDP bone scintigraphy demonstrated intense uptake corresponding to the site of the bladder tumor. Chemisorption of urinary 99mTc-HMDP, rather than of blood-born 99mTc-HMDP, may have occurred at the tumor surface.

Bone Neoplasms↗
PubMed1997

[Sudden onset of bronchospasm and persistent hypotension during spinal anesthesia in a patient on long-term psychotropic therapy].

We experienced perioperative management of a patient on long-term psychotropic therapy. The patient was a 65-year-old man who underwent TUR of the prostate under spinal anesthesia. Bronchospasm and persistent hypotension occurred immediately after the beginning of TUR. Aminophylline improved bronchospasm, but it was difficult to keep blood pressure with continuous infusion of norepinephrine or epinephrine. The patient recovered from anesthesia safely. We should pay attention to bronchospasm as well as hypotension in a patient on long-term psychotropic therapy during perioperative period.

Aminophylline↗
PubMed1996

Non-neurogenic periodic fluctuations in heart rate and vasomotion appearing in familial amyloid polyneuropathy (FAP) Type I (Met30).

In order to evaluate the function of the autonomic nervous system, power spectral analysis of heart rate fluctuation and waveform observation of cutaneous vasomotion were conducted in 3 patients with familial amyloid polyneuropathy Type 1 (FAP) (Met30) with autonomic disorders. In 2 FAP patients in the early stage, both high (HFC: 0.12-0.4 Hz) and low frequency components (LFC: 0.04-0.12 Hz) in the heart rate spectrum, and basic (BW) and reflex waves (RW) in the vasomotion were all markedly suppressed. However, in an FAP patient in the advanced stage, prominent spectral peaks were recognized in both the spectral bands of LFC and HFC. HFCs were neither correspondent with the respiratory frequency nor depressed by atropine, and BW was not affected by acute denervation using a local anesthetic. RW was absent irrespective of the denervation. These results suggest that the denervated heart and vascular smooth muscles might have newly acquired periodic fluctuations, although the physiological mechanism and meanings remain to be investigated.

Adult↗
PubMed1996

Enhanced glomerular profilin gene and protein expression in experimental mesangial proliferative glomerulonephritis.

Profilin is a cytoplasmic protein that binds to actin monomer and regulates actin polymerization. In a number of experimental and human glomerular diseases, the mesangial cell expresses alpha-smooth muscle actin and undergoes a phenotypic change to myofibroblast. We used a rat model of mesangial proliferative nephritis induced with antibody to the Thy 1 antigen present on mesangial cells to investigate whether profilin is upregulated. We amplified and sequenced rat profilin cDNA by the reverse-transcribed-polymerase chain reaction (RT-PCR). The nucleotide and amino acid sequences were highly conserved across the mammalian profilins. We raised affinity purified antibody to rat profilin in rabbits immunized with a synthetic profilin peptide (EFTMDLRTKS). At 7 days after disease induction, enhanced expression in both profilin mRNA and protein was demonstrated in the isolated glomeruli by RT-PCR and Western blot analysis. These results suggest that profilin may be involved in the pathogenesis of glomerulonephritis by reorganizing actin cytoskeleton.

Amino Acid Sequence↗
PubMed1996

Extracellular matrices in peritendinous connective tissue after surgical injury to the chicken flexor tendon.

Gene expression of fibronectin, type I collagen and type III collagen and the presence of fibronectin in peritendinous connective tissue were investigated, following flexor tendon injury, using slot-blot hybridization and immunohistochemistry. Fibrous adhesion around the chicken flexor tendon was induced by a partial laceration using a surgical knife. Total RNA was purified from the peritendinous connective tissue surrounding a tendon by combining the guanidine thiocyanate procedure and isoelectric precipitation. Slot-blot hybridization revealed that gene expression of fibronectin and collagens type I and III increased gradually after tendon injury, and levels were maintained high throughout the experimental period of 16 weeks. Indirect immunofluorescence revealed fibronectin to be preferentially located in peritendinous connective tissue around the injured tendon. The prolonged increase of fibronectin in the peritendinous connective tissue may relate to the development of histological adhesion after flexor tendon injury.

Animals↗