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Biomedical subjects

H Harada

Publications and source records attributed to H Harada.

At least 523 records · Page 29Linked to original sources
PubMed1989

Structurally similar but functionally distinct factors, IRF-1 and IRF-2, bind to the same regulatory elements of IFN and IFN-inducible genes.

Viral infections commonly induce expression of type I interferon (IFN) genes. The induction is transient and involves transcriptional activation wherein a positive factor, IRF-1, binds to upstream regulatory cis elements. In the present study we report the isolation of a cDNA encoding a novel factor, termed IRF-2, that interacts with the same nucleotide sequence elements as IRF-1. Both genes are inducible not only by virus but also by IFN. Unlike IRF-1, IRF-2 does not function as an activator; rather, it suppresses the function of IRF-1 under certain circumstances. Our results suggest that transcription of the IFN and IFN-inducible genes is regulated by two similar trans-acting factors that apparently compete for the same cis-acting recognition sequences, but which have opposite effects.

Amino Acid Sequence↗
PubMed1989

Phosphorylation of mu-opioid receptors--a putative mechanism of selective uncoupling of receptor--Gi interaction, measured with low-Km GTPase and nucleotide-sensitive agonist binding.

The mu-opioid receptor agonist stimulation of low-Km GTPase in rat striatal membranes was abolished by islet-activating protein (IAP) treatment, and recovered by Gi reconstitution. When the IAP-treated membranes were phosphorylated with a cAMP-dependent protein kinase, there was no such recovery by Gi. The agonist binding was not affected with respect to Kd, Bmax and sensitivity to guanine nucleotides in the phosphorylated membranes. These findings suggest that phosphorylation of mu-opioid receptors dissociates the agonist change in G-protein activity from the guanine nucleotide-sensitive agonist binding.

Animals↗
PubMed1989

Rapid assay of beta-galactosidase and sialyltransferase by lectin affinity high performance liquid chromatography with fluorescence detection.

Fluorescein isothiocyanate (FITC)-labelled asialotransferrin and pyridyl aminated oligosaccharides were prepared from asialotransferrin and human milk using affinity chromatography and high performance liquid chromatography (HPLC), respectively. These substances were incubated with galactosidase or sialyltransferase and then examined by lectin affinity HPLC. The elution patterns changed according to the period of incubation and amount of enzyme. This analytical method using lectin affinity HPLC with fluorescence labelled glycoprotein or oligosaccharides as the substrates has great value for detecting these enzyme under the same chromatographic conditions. In addition, differences were noted in the activity of beta-galactosidase toward oligosaccharides having the Gal beta(1----3)GlcNAc or Gal beta(1----4)GlcNAc structure at reducing termini.

Chromatography, Affinity↗
PubMed1989

Prognosis and prognostic factors in chronic pancreatitis.

To evaluate the prognosis and prognostic factors of chronic pancreatitis, 84 patients with alcoholic chronic pancreatitis and 51 with nonalcoholic chronic pancreatitis have been followed for 1-21 years (average of 7.1 years). The follow-up period was defined as the period from diagnosis to death in those who died and to the present in those still alive. The following conclusions were obtained. (1) Patients with alcoholic chronic pancreatitis showed a significantly higher mortality rate (26.2%) and cancer death rate (8.3%) than the age- and sex-matched population. In patients with nonalcoholic chronic pancreatitis, however, the difference did not reach the level of statistical significance, although both rates tended to be higher. (2) Patients with alcoholic chronic pancreatitis showed a significantly poorer prognosis than those with nonalcoholic chronic pancreatitis. (3) Frequent causes of death in chronic pancreatitis were cancer (11 cases) and diabetes-associated conditions (renal failure in three cases, intractable pneumonia in one, hypoglycemic shock in two, and myocardial infarction in two). Death directly from pancreatitis was observed in four. (4) Unfavorable prognostic factors in alcoholic chronic pancreatitis included heavy drinking, continuance of drinking after diagnosis, smoking, insulin-dependent diabetes, and an advanced age. In nonalcoholic chronic pancreatitis, however, patients' age was the only significant prognostic factor; smoking did not reach the level of statistical significance, although it tended to lead to a poorer prognosis.

Adult↗
PubMed1989

Chemical structure and toxicity of diuretics in isolated hepatocytes.

The effects of several diuretics, including tienilic acid and indacrinone, on isolated rat heaptocytes were examined. Addition of tienilic acid and indacrinone at 1 mM to a suspension of freshly isolated cells caused dose-dependent loss of cell viability as judged by the LDH-latency test. Survey of 19 structurally related compounds revealed that the extent of cell injury and chemical structure were correlated, and an intense adverse effect was attributed to the 2-thienylcarbonyl moiety. Several other factors influencing cell viability are also disclosed. Further study revealed that tienilic acid and indacrinone were toxic to the primary culture of hepatocytes at a lower dose than that a freshly isolated hepatocytes. Thus, an isolated hepatocyte system can be used to select compounds displaying low hepatotoxicity, as for example is needed when screening diuretics.

Animals↗
PubMed1989

Prevention of interleukin 2-induced acute lung injury in guinea pigs by pentoxifylline.

We administered recombinant human interleukin 2 (IL-2) to guinea pigs to investigate whether IL-2 would cause acute lung injury. In addition, we examined the effects of pentoxifylline (PTXF) on IL-2-induced acute lung injury. Three groups of animals were studied over a period of 8 h. The saline control group was injected intravenously with 2 ml of pyrogen-free saline; the IL-2 group was injected intravenously with 4 X 10(6) U/kg recombinant IL-2; and the IL-2-PTXF group was injected with a 20-mg/kg bolus of PTXF followed by a continuous infusion (6 mg.kg-1.h-1) started 60 min before injection of 4 X 10(6) U/kg IL-2. Lung water (wet-to-dry lung weight ratio), the concentration ratios of 125I-albumin in bronchoalveolar lavage (BAL) fluid and lung tissue compared with plasma (125I-albumin BAL-to-plasma, 125I-albumin lung-to-plasma), and cell counts in BAL fluid were examined. An intravenous injection of IL-2 caused an increased lung water (P less than 0.01), an increased 125I-albumin lung-to-plasma ratio (P less than 0.05), and a significant increase in the absolute number of neutrophils, lymphocytes, and macrophages in BAL fluid compared with the saline control. In contrast, the PTXF-pretreated group did not demonstrate IL-2-induced acute lung injury (lung water, 125I-albumin lung-to-plasma) or increased accumulation of neutrophils, lymphocytes, and macrophages in the BAL. These data suggest a possible role for PTXF in attenuating the side effects of IL-2.

Acute Disease↗
PubMed1989

Pentoxifylline prevents tumor necrosis factor-induced lung injury.

Human tumor necrosis factor-alpha (TNF) is a monokine produced by mononuclear cells after many stimuli, including bacterial endotoxin. Full exploration of its antineoplastic effects has been limited by side effects. We have previously shown that the administration of TNF to guinea pigs is associated with a syndrome similar to gram-negative septic shock, which includes capillary permeability lung injury. In this study, we measured the effects of pentoxifylline (PTX) on parameters of TNF-induced lung injury including: lung wet-to-dry weight ratio, the ratio of lung-to-plasma 125I-labeled albumin (albumin index), bronchoalveolar lavage (BAL) and peripheral leukocyte counts, and serial measurements of mean arterial pressure (MAP). Four groups of animals were studied: a TNF group received 3.75 x 10(6) U/kg TNF; a PTX group received a 20-mg/kg bolus of PTX followed by an infusion of 6 mg/kg/h; the PTX-TNF group received both; and the final group was a saline control. ANOVA analysis revealed significant elevations of lung wet-to-dry ratio only in the TNF group (5.9 [5.6 to 6.3], p less than 0.001), expressed as the mean followed by 95% confidence intervals). Lung albumin index was elevated only in the TNF group (0.24 [0.19 to 0.29], p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The effects of aminophylline and pentoxifylline on multiple organ damage after Escherichia coli sepsis.

We studied the effects of the methylxanthines, aminophylline (AMPH) and pentoxifylline (PTXF), on multiple organ damage following Escherichia coli sepsis in guinea pigs. To assess multiple organ damage, 125I-labeled albumin accumulation was measured in bronchoalveolar lavage (BAL) fluid, lung, kidneys, liver, heart, adrenal glands, and spleen and expressed as a ratio of BAL fluid or tissue to 125I-labeled albumin plasma (albumin index: Al). Wet-to-dry lung weight (W/D) ratios were also measured. The methylxanthines were administered by a bolus injection followed by a continuous infusion. The seven experimental groups included: saline-control, AMPH-control, PTXF-control, E. coli septic-control, E. coli septic-AMPH high dose, E coli septic-AMPH low dose, and E. coli septic-PTXF. The AI of the BAL fluid and all examined organs significantly increased in the septic-control group compared to those in the saline-, AMPH-, and PTXF-control groups, In all septic-methylxanthine groups, the AI of the BAL fluid and all organs, except for the spleen, were significantly lower than those of the septic-control group. Compared to the saline-, AMPH-, and PTXF-control groups, the septic-control group revealed a significant increase in lung W/D ratios, whereas the septic-AMPH high and low dose groups and the septic-PTXF group did not. Of importance, the septic-PTXF group did not cause a significant decrease in mean arterial pressure (MAP) as compared to the control groups, whereas the septic-AMPH groups did cause a significant decrease in MAP compared to the septic-control group. Therefore, the data from this experiment demonstrate that both AMPH and PTXF attenuate the multiple organ albumin leak seen in septic guinea pigs. However, PTXF exerted this protective effect with no discernible effect on the MAP whereas the MAP of AMPH-treated guinea pigs was significantly decreased.

Albumins↗
PubMed1989

Synthetic studies on diuretics. 5-(3,3-N,S-substituted-2-propenoyl)-2,3-dihydro-2- benzo[b]furancarboxylic acids.

6,7-Dichloro-2,3-dihydro-2-benzo[b]furancarboxylic acid derivatives having a 3,3-N,S-disubstituted-2-propenoyl group at the 5-position were prepared by alkylation of 5-(thiocarbamoyl)acetyl derivatives of the 2,3-dihydro-2-benzo[b]furancarboxylic acid ester or by acetal exchange reaction of 5-[3,3-bis(alkylthio)-2-propenoyl] derivatives. Synthesis of 5-[4 and/or 5-(di)substituted-4-thiazolin-2-ylidene]acetyl-2,3- dihydro-2-benzo[b]furancarboxylic acids was also achieved by the reaction of 2-halo-1-methoxyethyl isothiocyanate with the 5-acetyl derivative in the presence of base or through sulfide contraction of 2-[[6,7-dichloro-2-methoxycarbonyl-2,3-dihydrobenzo[b]furan-5-yl) carbonyl)-methylthio]thiazolium bromide. Some of the compounds which were synthesized showed potent natriuretic activities in rats and mice. The structure-activity relationship is also discussed.

Animals↗
PubMed1989

Inhibitory effect of calcitonin on pure human pancreatic secretion.

The inhibitory effect of calcitonin on human pancreatic secretion was evaluated to examine whether the different results reported earlier between humans, cats and dogs can be ascribed to the different sensitivity of these species to calcitonin, as suggested by some investigators. Pancreatic juice was obtained by endoscopic cannulation of the pancreatic duct from 11 patients with relapsing pancreatitis during intravenous infusion of secretin (1 U/kg/h) plus caerulein (0.04 microgram/kg/h). After steady secretion was attained 20 min after the beginning of collection, five 2-min fractions were obtained before, and ten 2-min fractions were obtained after intravenous infusion of calcitonin (1 IU/kg/h). The pre- and post-calcitonin fractions from each patient were compared by Student's t-test. Calcitonin inhibited the secretory volume (26.8 to 65.6%) and bicarbonate secretion (21.4 to 62.0%) in 8 patients, and amylase (48.4 to 89.5%) and lipase secretion (47.4 to 90.5%) in all patients. The present studies reconfirmed that prominent inhibition of enzyme secretion occurs in humans. A new finding was that significant inhibition of the secretory volume and bicarbonate secretion occurs in humans. The inhibitory effects of calcitonin in humans did not appear to differ from those in cats and dogs, when evaluated similarly with the use of pure pancreatic juice.

Aged↗
PubMed1989

[Aging and exocrine pancreatic function].

To evaluate the effect of aging on exocrine pancreatic function, fecal chymotrypsin activity (FCA) was measured by a photometric method in 62 healthy controls (20 to 87 years old, average 51.0 years), 42 patients with non-pancreatic diseases (31 to 83 years old, average 56.1 years), 40 controls in an old-age home (63 to 92 years old, average 77.6 years), 20 patients with definite chronic pancreatitis (17 to 72 years old, average 53.5 years) and five patients with pancreatic cancer (60 to 76 years old, average 65.4 years). Exocrine pancreatic function showed a significant decrease with aging as indicated by: (a) a significant inverse correlation between aging and FCA in the 62 healthy controls (r = -0.56, p less than 0.001), in the 42 patients with non-pancreatic diseases (r = -0.59, p less than 0.001), and also in the 40 controls in an old-age home (r = -0.52, p less than 0.001); and (b) a significantly lower FCA in the 21 healthy controls aged 65 or more (designated as the B group of healthy controls) than the 41 healthy controls aged less than 65 (designed as the A group of healthy controls). The 40 controls in an old-age home showed significantly lower FCA than the B group of healthy controls. This result was ascribed to the fact that the former group consisted of significantly older subjects than the latter. No significant difference was found in FCA between patients with chronic pancreatitis, those with pancreatic cancer, the B group of healthy controls, and the controls in an old-age home.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[A case of left ventricular pseudoaneurysm with severe cardiac failure and premature ventricular beats].

A surgically successful case of left ventricular pseudoaneurysm 10 years after an acute myocardial infarction was reported. A 63-year-old man had an acute inferior myocardial infarction 10 years ago. Recently congestive heart failure and premature ventricular beats developed. He was diagnosed as a left ventricular pseudoaneurysm by echocardiogram, CT scan, and left ventriculogram. After the operation, the symptoms diminished and improvement of left ventricular function was observed. A brief review of the literature is given.

Cardiac Complexes, Premature↗
PubMed1989

[Five cases referred to the First Department of Oral Surgery due to failure of impacted mandibular third molar extraction].

Of patients referred to our department over the post two years due to failure of tooth extraction 5 with impacated mandibular third molars were treated. We found that extraction had been hindered by the narrow operative field due to inadequate incision of the overlying mucosal tissue, insufficient bone resection and inadequate separation of the crown and root.

Humans↗