Using T-DNA tagging to search for genes involved in the mechanism of phytohormone action.
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DNA, Bacterial↗
Biomedical subjects
H Hayashi
Publications and source records attributed to H Hayashi.
Basolateral Cl-/HCO3- exchange in epithelial cells from guinea pig distal colon.
In guinea pig distal colon, H+ secretion into the lumen due to the apical ouabain-sensitive H+, K(+)-ATPase activity is associated with HCO3- exit into the serosa. This study aimed at elucidating (1) the transport mechanism of HCO3- exit across the basolateral membrane and (2) the relation of lactate release to the H+, K(+)-ATPase activity, in isolated mucosae mounted in Ussing chamber. The HCO3- exist across the basolateral membrane depended on the serosal Cl-. 4,4'-Diisothiocyanostilbene- anostilbene-2,2'-disulfonic acid (DIDS) applied to the serosal side reduced the rate of HCO3- exit across the basolateral membrane. The lactate was released to the serosal side, but not to the luminal side. The serosal lactate appearance was abolished when the apical H+, K(+)-ATPase was inhibited by luminal ouabain. These results suggest that HCO3- exit across the basolateral membrane is mediated by a DIDS-sensitive Cl-/HCO3- exchange. In addition, the lactic acid production appears to be coupled to the apical H+, K(+)-ATPase activity.
4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
Biochemical improvement of chronic hepatitis C after gastrointestinal bleeding.
Although chronic hepatitis C is frequently complicated by iron overload, it remains unclear whether iron cytotoxicity is involved in the disease process. Five patients with chronic hepatitis C showed rapid reduction of serum aminotransferase activity after gastrointestinal bleeding. Posthemorrhagic reduction of liver enzyme levels lasted for more than one week. Anemia was associated with a reduction of serum ferritin concentration. Considering the short half-lives of circulating liver enzymes, reduced release of enzymes, that is inactivation of cell lysis, is the likely cause of the improved biochemical indices. Reactive iron, which is cytotoxic for patients infected by HCV, may be rapidly incorporated into hemoglobin when erythropoiesis is stimulated. Our observation also suggests that intensive iron removal by phlebotomy is a safe, economic treatment for patients with chronic hepatitis C.
Aged↗
Interleukin-1 down-regulates type I interleukin 1 receptor mRNA expression in a human fibroblast cell line TIG-1 in the absence of prostaglandin E2 synthesis.
We have shown that interleukin-1 (IL-1) up-regulates transcription of its own receptor and number of cell surface IL-1 receptor (IL-1R) type I molecule through induction of prostaglandin E2 (PGE2) synthesis and subsequent intracellular cAMP accumulation in a human lung fibroblast cell line (TIG-1). In this study, the effect of IL-1 on IL-1R mRNA expression was investigated in the absence of PGE2 synthesis. In the presence of indomethacin, an inhibitor of cyclooxygenase, IL-1 inhibited the expression of IL-1R mRNA within 4 h after treatment, and the inhibition sustained at least for 24 h. IL-1 beta as well as IL-1 alpha at higher than 1 U/ml exhibited the inhibitory effect. The inhibitory effect of IL-1 was inhibited by cycloheximide suggesting that de novo protein synthesis is required. IL-1 appeared to destabilize IL-1R mRNA within 30 min after treatment of the cells. Furthermore, this effect of IL-1 was not observed in a synthetic medium and was dependent on serum concentrations indicating that a serum component(s) is involved. These results indicate that IL-1 regulates IL-1R mRNA expression in both a positive and negative manner, and that the negative effect represents a negative feedback mechanism.
Cell Line↗
Signaling pathway other than phosphatidylinositol turnover is responsible for constant expression of c-myc gene in primary cultures of rat hepatocytes.
We investigated signal transduction pathways involved in c-myc activation, using rat hepatocytes in primary culture. c-Myc mRNA was constantly expressed in the cultured hepatocytes regardless of the conditions present. When the expression was examined in the presence of various agents modulating intracellular signals, isoflavonoids (genistein, psi-tectorigenin, and orobol) significantly decreased c-myc mRNA levels, in a dose dependent manner. However, genistein did not decrease Li+ induced inositol phosphate accumulation using [3H]inositol-labeled cultured hepatocytes. In addition, we have shown that these isoflavonoids increase cytoplasmic free Ca2+, when measured using aequorin-loaded hepatocytes. In light of these observations, the persistent basal level of c-myc expression seems to be maintained by mechanisms other than phosphatidylinositol turnover.
Animals↗
[A multicenter clinico-epidemiological study of HTLV-I associated uveitis].
To elucidate the clinical and epidemiologic features of HTLV-I associated uveitis (HAU), a multicenter case-control study was performed by collaboration of university hospitals throughout Kyushu and Okinawa and two university hospitals in the central metropolitan area. A total of 426 cases of endogenous uveitis were collected and studied between September 1992 and January 1993; about half of the cases were definable for etiology or clinical entity, and the remaining cases were unknown. Assessment of the serum antibodies to HTLV-I revealed that the group of entity-undefined uveitis had a significantly high prevalence of HTLV-I as compared with the age- and sex-matched control subjects, giving supportive evidence for HAU. The titer of serum HTLV-I antibodies was significantly higher in entity-undefined uveitis than in HTLV-carriers. Assuming that a collection of 50 cases of HTLV-I seropositive, etiology-undefined uveitis represents HAU, its clinical features consisted were: (1) middle-aged, otherwise healthy adults developed acute inflammatory uveal disease and presented with visual haze and/or floaters; (2) the disease showed granulomatous or nongranulomatous anterior uveal reactions accompanied by vitreous opacities and retinal vasculitis; (3) the lesions resolved in response to topical or systemic corticosteroids; (4) the visual outcome was usually favorable; (5) nearly half of the cases had recurrent disease; (6) the cases remained systemically unremarkable, except for two cases of HTLV-I associated myelopathy and eight cases of hyper thyroid disease.
Adolescent↗
[Molecular mechanisms of insulin-stimulated glucose uptake and PI3-kinase].
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Animals↗
Estrous-related variations of blood pressure and heart rate in female rats.
In female rats, several biological variables change with a 4 or 5 day estrous cycle. To clarify whether blood pressure and heart rate show estrous-related changes, we measured three variables, i.e. mean arterial pressure (MAP), heart rate (HR) and spontaneous activity (ACT), using an implantable radiotelemetry transmitter and a computerized data collecting system non-invasively and chronically for more than 2 months. Under a 12-12 light-dark cycle, the three variables revealed clear daily variations and modulations by the estrous cycle which were most pronounced in the proestrous night. During the proestrous night, ACT showed a remarkable increase and a peak in the first half of the night, whereas MAP showed a gradual increase and a peak around midnight, and HR remained low without forming a peak. All modulations by the estrous cycle disappeared following bilateral ovariectomy. It is concluded that daily variations of blood pressure and heart rate are modulated according to the estrous cycle.
Animals↗
A light microscopic study of glomerulosclerosis in Japanese patients with noninsulin-dependent diabetes mellitus: the relationship between clinical and histological features.
We studied the relationships of renal lesions with clinical features and renal prognosis in 128 Japanese patients with noninsulin-dependent diabetes mellitus (NIDDM). Diabetic glomerulosclerosis (DMGS) was found in 108 cases (84.4%), and DM-associated glomerulonephritis (GN), IgA nephropathy and membranous nephropathy, was in 20 cases (15.6%). There was no significant difference in age at renal biopsy, age at DM onset, DM duration, glomerular filtration rate (GFR), urine protein and serum IgA level between patients with DMGS and DM-associated GN. With respect to histological parameters, the increase in mesangial matrix was more closely related to DM duration, GFR and urine protein than to the degree of glomerular sclerosis. The index of glomerular lesion (IGL), which was calculated by combining these two lesions, had a more significant correlation with the clinical features than the tubulo-interstitial lesions. We suggested that the mesangial change was an initiating reaction, and the interstitial one was secondary in NIDDM patients. The prognosis of renal function after renal biopsy of the patients whose serum creatinine level was less than 1.2 mg/dl, was poorer in cases with nodular lesion than in those with diffuse lesion. The grade of tubulo-interstitial lesion was also more severe in these patients with nodular lesion. However, the controls of blood glucose, blood pressure, serum total cholesterol were not different among the two groups. On the other hand, serum creatinine level of most patients with associated GN did not change for a long period, up to 10 years.(ABSTRACT TRUNCATED AT 250 WORDS)
Biopsy↗
Development of glycosylated human interleukin-1 alpha, neoglyco IL-1 alpha, coupled with D-mannose dimer: synthesis and biological activities in vitro.
Interleukin 1 (IL-1) is a nonglycosylated cytokine with pleiotropic effects on various cell types. In order to investigate the effect of carbohydrate introduction on IL-1 activity and to develop IL-1 with less deleterious effects recombinant human IL-1 alpha was chemically coupled with mannose dimers, alpha-D-Man1-6-D-Man[Man2(alpha 1,6)] and alpha-D-Man1-4-D-Man[Man2(alpha 1,4)]. About 5 molecules of mannose dimers were introduced per molecule of IL-1. Anti-IL-1 alpha antibody reacted only weakly with the glycosylated IL-1s. Conversely, antibody against the mannose dimer reacted with only glycosylated IL-1. The effect of glycosylation on IL-1 activity was evaluated by measuring a variety of IL-1 activities in vitro, including proliferative effect on T cells, antiproliferative effect on melanoma cells, stimulatory effect on IL-6 synthesis by melanoma cells, and stimulatory effect on prostaglandin E2 synthesis by fibroblast cells. Glycosylated IL-1s exhibited reduced activities, which were 10-fold to more than several hundred-fold lower than those of the original IL-1 alpha depending upon different aspects of activities addressed. Man2(alpha 1,6)-introduced IL-1 exhibited lower activity than Man2(alpha 1,4)-introduced IL-1. The competitive binding of 125I-IL-1 alpha to mouse T cells with unlabeled IL-1s suggests that the reduced activity of glycosylated IL-1s is due, at least partially, to the decrease of their receptor binding abilities.
Animals↗
Improvement of serum aminotransferase levels after phlebotomy in patients with chronic active hepatitis C and excess hepatic iron.
OBJECTIVES: Iron metabolism may be altered in patients with chronic active hepatitis C. In an attempt to evaluate whether excess iron contributes to liver injury, we used phlebotomy for removal of iron from patients with chronic hepatitis C. METHODS: All 10 patients had histochemically detectable iron in the liver and underwent an initial period of weekly or monthly phlebotomy of 200 or 400 ml. A serum ferritin level of 10 ng/ml or less was chosen as the endpoint, and maintenance phlebotomy was performed if the level rebounded. RESULTS: The treatment reduced mean serum alanine aminotransferase activity from 152 +/- 49 to 55 +/- 32 IU/L; this level became normal in five of the 10 patients. Anti-HCV antibodies could be detected in all patients throughout the study. Histologic abnormalities of the liver were unchanged except for disappearance of iron deposits from seven of the patients studied. CONCLUSIONS: Our findings suggest that iron removal may be beneficial for patients with chronic active hepatitis C and histochemical iron in the liver.
Adult↗
The amino acid sequence and phosphorylation sites of a boar transition protein 1.
Boar transition protein 1 was extracted with acid from the testes, purified by chromatographies on CM-Sephadex C-25 and Sephadex G-50, and reduced and carboxymethylated. The modified protein was purified by HPLC on Nucleosil 300 7C18. The primary structure of the protein was determined by automated Edman degradation of the C-terminal peptide of the BrCN-cleaved protein and of the whole protein, and by carboxypeptidase digestion of it. The study of phosphorylation sites showed that Ser36 and Ser39 in the very conserved sequence 29-42 were partly phosphorylated, suggesting the involvement of this region in the interaction with DNA.
Amino Acid Sequence↗
[Maternal working status and low birthweight: findings from a cohort study].
To explore possible associations of maternal working status with birthweight, a cohort study was conducted from July, 1989 to June, 1991 in 8 general hospitals in the Tokai district. Using a self-administered questionnaire, data on job employment were collected mostly in the first or second trimester. Information on delivery outcome was recorded by doctors, midwives or nurses after child birth. Included in this analysis were 1,360 pregnants who delivered a live singleton without major malformations at gestation of 37 weeks or more. The following major findings emerged. (1) No significant difference in mean birthweight was detected between working and non-working pregnants. (2) Working pregnants were at greater risk of delivering a low birthweight (< 2,500g) baby. (3) Delivery of a low birthweight baby was more frequent in multiparous than nulliparous mothers. (4) The risks of delivering a low birthweight baby significantly differed according to the maternal working status. (5) These results suggest that not only the maternal working factor itself but the working status should be deliberately taken into consideration in order to provide proper prenatal care.
Adolescent↗
Influence of hepatectomy on cell infiltration in the resected liver parenchyma compared with the biopsy specimen--a preliminary study.
We undertook a preliminary investigation to determine whether or not preoperative hepatitis activity can be evaluated by the finding of cell infiltration into the parenchyma of the resected specimen. In 28 patients who underwent hepatic resection, liver biopsies were obtained just after the laparotomy in order to make a histological comparison with the resected liver specimen. Histological changes were observed in 11 out of 28 patients. However, these were limited to minimal changes of neutrophil infiltration in the portal and subserosal area with no derangement of chronic cell infiltration. In addition, the preoperative liver function and operative findings did not differ between patients with and those without histological changes. The activity of hepatitis was therefore seen not to be histologically influenced by the surgical procedure. Thus, an accurate evaluation of chronic inflammatory cell infiltration activity in the resected liver specimen is a reliable indicator in chronic liver disease patients.
Adult↗
[Acute encephalopathy with symmetrical lesions of the thalamus, the putamen and the cerebellum on magnetic resonance imaging].
A 19-year-old boy was admitted to our hospital because of impaired consciousness after experiencing fever and headaches for 7 days. The patient was in a deep coma or generalized convulsions, with retrocollis and decorticate posture. He never regained consciousness, remaining in an apallic state. The initial CSF pressure was 290 mm H2O, CSF cell count 18/3 mm3, protein 75 mg/100 ml, and sugar 74 mg/100 ml. There was no significant elevation in the viral titer in the serum or CSF. Plain CT on admission showed marked brain edema. MRI three months thereafter demonstrated symmetrical high intensity in the thalamus, the putamen and the cerebellum on both T1- and T2-weighted images, probably representing petechial bleeding. The lesions in the medial portion of the occipital lobes showed iso intensity on T1-weighted images and high intensity on T2-weighted images. These lesions were consistent with infarction of both posterior cerebral arteries, which may have been due to severe brain edema. The clinical and MRI findings were similar to those of patients with acute encephalopathy with low-density areas in the thalamus or bilateral striatal necrosis in childhood. To the best of our knowledge, there have been no reports of cases like ours in adults.
Acute Disease↗
Novel growth promoting activity with a wide target cell spectrum is present in extracts of various cell types.
Cell extracts from a variety of cell lines, myeloid, T, B, mastocytoma, fibroblast, melanoma and breast carcinoma of human, mouse and guinea pig promoted the growth of a wide variety of cell types, namely human myeloid cells HL-60, human B cells Daudi, human melanoma cells A375-C6, mouse transformed-fibroblast cells L929, human myelomonocytic cells THP-1. Among them, the activities in extracts from U937, A375-C6 and Daudi were characterized because these extracts exhibited much more potent activity. These growth promoting activities were acid-labile, sensitive to 2-mercaptoethanol and to heat treatment at 50C or 70C for 5 min. The activities were also sensitive to proteases indicating the proteinous nature of these active entities. The molecular weight of activities from A375 and Daudi cells were estimated to be 100,000-150,000 daltons by gel filtration high performance liquid chromatography, while that from U937 cells was 60,000-70,000 daltons. The isoelectric point of these activities were 5.5-6.5.
Animals↗
[Objective evaluation of apparent accommodation of pseudophakic eyes].
In 23 (9 males and 14 females) pseudophakic eyes which had a biconvex type intraocular lens (IOL) implanted after cataract extraction, we objectively measured changes in the anterior chamber (AC) depth caused by axial movement of the IOL accompanying accommodation of the contralateral phakic fellow eye, using a Schimpflug slit image with an anterior eye segment image analysis system (Nidek, EAS-1000, Japan). In 114 phakic eyes of 57 persons as controls, AC depths accompanying accommodation from distances of 5 m to 30 cm and 10 cm decreased with increasing age. The decreased mean value of AC depth with accommodation from distances of 5 m to 30 cm was 0.17 mm in patients in their teens, 0.15 mm in patients in their 20 s, 0.10 mm in the 30 s, 0.06 mm in the 40 s, 0.05 mm in the 50 s, and 0.03 mm in the 60 s. The decrease of AC depth with accommodation at a distance of 10 cm was 0 in patients in their 60 s. In the pseudophakic eye changes in anterior chamber depth caused by focusing at short distances were less than 0.04 mm, and decreasing rate of anterior chamber depth (DRAC) was less than 1% in all the pseudophakic eyes. Movement of IOL on the optical axis was too subtle to account for apparent accommodation of the pseudophakic eye.
Accommodation, Ocular↗
Improved insulin release from a bioartificial pancreas using mesh-reinforced polyvinyl alcohol hydrogel tube: immobilization of islets in agarose gel.
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Animals↗