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Biomedical subjects

R Fukunaga

Publications and source records attributed to R Fukunaga.

68 records · Page 4Linked to original sources
PubMed1986

Echo-Doppler velocimeter in the diagnosis of hypertensive patients: the renal artery Doppler technique.

The renal blood flow velocity characteristics in 8 normal controls, 19 essential hypertensive patients and 8 hypertensive patients with renovascular disease were evaluated using echo-Doppler velocimetry. Two different approaches for ultrasonic detection of the renal artery, the translumbar and the transabdominal approach, were used. Renal Doppler sonograms were analyzed by measuring the acceleration index and the peak-systolic frequency/end-diastolic frequency (S/D) ratio. Renovascular patients who required surgery were examined before and after angioplasty. Doppler signals could be detected in all 35 subjects by using the translumbar approach. The acceleration index of the affected renal arteries significantly correlated to the percent stenosis of the renal artery determined by angiography. The acceleration index in the affected renal artery was improved by surgical treatment. The S/D ratio in essential hypertensives was significantly higher than that in the normal controls. There was a significant inverse correlation between the S/D ratio and creatinine clearance. Echo-Doppler velocimetry is considered to be useful in the diagnosis of renovascular disease and also in the evaluation of abnormalities of renal vascular resistance in hypertensive patients.

Adolescent↗
PubMed1986

Structure and expression of a cloned cDNA for human (2'-5')oligoadenylate synthetase.

17S poly(A)+RNA, which hybridized to an oligonucleotide complementary to a part of the partial cDNA (E1cDNA) (Merlin et al. (1983) Proc. Natl. Acad. Sci. U.S. 80, 4904) for 2-5A synthetase, was isolated from interferon-treated human KB cells and used for cDNA cloning. Several overlapping cDNAs were cloned by using the oligonucleotide as a probe. Two of them were joined at their overlapping region, resulting in a cDNA (22-1 cDNA) of 1.4 kb containing a long open reading frame. When the cDNA was expressed in COS-7 cells with an eukaryotic promoter, active 2-5A synthetase was produced and localized mainly in the cytoplasm. The 5'-proximal ATG in 22-1 cDNA is followed immediately by another ATG. This second ATG was assumed to work as the initiator codon. If so, this enzyme comprises 363 amino acids.

2',5'-Oligoadenylate Synthetase↗
PubMed1986

Induction of human interferon-gamma mRNA analyzed by cytoplasmic dot hybridization: effect of Con A, TPA, and A23187.

The cytoplasmic dot hybridization method was improved by eliminating non-specific false signals. The non-specific binding to a probe disappeared almost completely when the hybridized nitrocellulose sheet was treated with pronase. Using this improved method we demonstrated that reagents such as 12-O-tetradecanoylphorbol-13-acetate (TPA), concanavalin A (Con A) and a calcium ionophore (A23187) could induce the expression of IFN-gamma gene of a human T-lymphoblastoid cell line, TCL-Fuj 2M, where TPA functioned synergistically with Con A and A23187. However, when the cells were cultured with the ionophore for more than one day the amount of IFN-gamma mRNA was markedly reduced to a low level.

Calcimycin↗
PubMed1986

Two monoclonal antibodies distinguish between human recombinant interferon-alpha 5s produced by Escherichia coli and by mouse cells.

Two monoclonal antibodies against human IFN-alpha--one against natural leukocyte IFN-alpha and the other against recombinant human IFN-alpha 2 produced in E. coli--were prepared, and designated as HT-1, and 104-5-f, respectively. These monoclonal antibodies were used to examine the antigenicities of recombinant human IFN-alpha 5s produced by E. coli and by mouse cells. The HT-1 antibody could bind and neutralize recombinant human IFN-alpha 5 synthesized in mouse cells, but not recombinant human IFN-alpha 5 synthesized in E. coli. On the other hand, the 104-5-f antibody could bind and neutralize recombinant human IFN-alpha 5 synthesized in E. coli but not recombinant human IFN-alpha 5 synthesized in mouse cells. Then these monoclonal antibodies or sheep polyclonal antibody against human IFN-alpha were used to immunoprecipitate the radioactively labeled recombinant human IFN-alpha 5 synthesized either in E. coli or mouse cells, and analysed on polyacrylamide gel electrophoresis in the presence of NaDodSO4. The labeled recombinant human IFN-alpha 5 produced by mouse cells could be immunoprecipitated with the HT-1 monoclonal antibody or sheep anti-(human IFN-alpha) polyclonal antibody but not with the 104-5-f monoclonal antibody and showed a band of Mr. 17,500 on polyacrylamide gel electrophoresis in the presence of NaDodSO4. On the other hand, the labeled recombinant human IFN-alpha 5 produced by E. coli could be immunoprecipitated with the 104-5-f monoclonal antibody but not with the HT-1 monoclonal antibody and showed a band of similar Mr. on polyacrylamide gel electrophoresis.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1986

[Properties of ATP-dependent H+-transport in rat brain synaptosomes].

Properties of the ATP-dependent H+-transport system in rat brain synaptosomes were examined using the acridine orange fluorescence quenching method. ATP-dependent H+-accumulation assessed by the quenching of acridine orange fluorescence was observed with the synaptosomes treated with hypotonic solution (hypotonic shock-synaptosomes), but not with the intact synaptosomes. With hypotonic shock-synaptosomes, H+-transport was activated in the presence of Cl- or Br-. However, this transport activity was markedly reduced in the presence of Mes-, NO3-, I- or SCN-. On the other hand, H+-transport activity was less effective with cations other than K+ in the following decreasing order of potency: K+ greater than Cs+ greater than Na+ greater than Li+. The H+-transport activity was inhibited by 0.3 mM ethacrynic acid, 10 microM 4-acetamide-4'-isothiocyanostilbene-2,2'-disulfonic acid or 1 mM 4-aminopyridine to 39.2%, 36.3%, or 33.1% of the control, respectively, but was not inhibited by 1 mM ouabain, 500 microM vanadate, 10 microM picrotoxin and 100 microM gamma-aminobutyric acid. These results suggest that the ATP binding site of the synaptosomal ATP-dependent H+-transport system exists on the internal surface of synaptosomal plasma membranes and that the H+-transport system is stimulated by the presence of Cl- or Br- and by K+ movement through the K+ channel.

Adenosine Triphosphate↗
PubMed1986

State of systemic hemodynamics in a case of juxtaglomerular cell tumor.

A renin-producing juxtaglomerular cell tumor was found in a 27 year-old woman. The infusion of angiotensin II analogue produced a marked decrease in arterial pressure. Oral administration of captopril also reduced her blood pressure. Although the renal vein renin did not indicate the laterality of the tumor, unilateral partial nephrectomy cured the disease. This is the first case report to describe measurement of several hemodynamic parameters before and after surgical removal of a juxtaglomerular cell tumor.

Adult↗
PubMed1984

Cerebral ischemic response-like hemodynamic changes induced by telencephalic ischemia in Mongolian gerbils (Meriones unguiculatus).

The effect of bilateral common carotid occlusion on systemic hemodynamics was investigated in the gerbil with and without bilateral carotid sinus denervation. Irrespective of the sinus denervation, telencephalic, severe ischemia produced significant changes in the heart rate and systemic arterial blood pressure, similar to those observed in cerebral ischemic response. These hemodynamic changes, associated with cerebral ischemia, may play an important role in affecting the pathophysiology of cerebral ischemia itself.

Animals↗
PubMed1984

Improvement of cerebral blood flow and/or CO2 reactivity after superficial temporal artery-middle cerebral artery bypass in patients with transient ischemic attacks and watershed-zone infarctions.

The effect of extracranial-intracranial bypass anastomosis on cerebral blood flow and CO2 reactivity during hypocapnia was investigated in ten patients with transient ischemic attacks or watershed infarctions due to carotid occlusive diseases. Six patients had occlusion and four had stenosis (greater than 50%) of the internal carotid artery. Those with infarctions had increased cerebral blood flow and CO2 reactivity postoperatively, and improved clinically. Those with transient ischemic attacks due to stenosis (greater than 50%) of the internal carotid artery had increased CO2 reactivity postoperatively but constant normal regional blood flow. Cerebral blood flow improved in those with poorer flow, CO2 reactivity increased in those with better reactivity, and better CO2 reactivity preoperatively brought about a greater flow increase. The pre- and postoperative evaluation of cerebral blood flow and CO2 reactivity is believed to be useful in evaluating the effectiveness of bypass anastomosis. Preoperative evaluation might be informative in selecting candidates for bypass.

Aged↗
PubMed1984

Constitutive production of human interferons by mouse cells with bovine papillomavirus as a vector.

Mouse C127I cells were transformed with a chimeric plasmid consisting of bovine papillomavirus and human interferon (HuIFN) gene (either IFN-gamma or IFN-alpha 5) placed under the control of simian virus 40 early promoter. The transformed cells retained 30-50 copies each of the hybrid plasmid extrachromosomally and secreted a high level of HuIFNs constitutively up to 3-4 X 10(5) international units/ml. The secreted HuIFN-gamma had no detectable activity on mouse cells, whereas HuIFN-alpha 5 was slightly active on mouse cells. Each IFN was neutralized either by anti-HuIFN-gamma or anti-HuIFN-alpha antiserum. The partially purified 35S-labeled HuIFN-gamma produced by the transformed cells showed heterogeneous bands with apparent Mrs of 22,000-25,000 on NaDodSO4/polyacrylamide gel electrophoresis. This value is similar to that of natural IFN-gamma and larger than the molecular weight calculated from the amino acid sequence, which suggests that HuIFN-gamma secreted by transformed mouse cells was glycosylated. The 35S-labeled IFN-alpha 5, immunoprecipitated with anti-HuIFN-alpha antiserum from the supernatant of the transformed cells, had a molecular weight of mature protein. These results suggest that the bovine papillomavirus vector can be used to produce a large quantity of foreign proteins in mammalian cells.

Animals↗
PubMed1984

Purification, crystallization, and molecular properties of aspartase from Pseudomonas fluorescens.

Aspartase [L-aspartate ammonia-lyase, EC 4.3.1.1] of Pseudomonas fluorescens was highly purified to homogeneity and crystallized. The purified enzyme sedimented as a monodisperse entity upon ultracentrifugation with a s0(20),w value of 8.6S. Upon polyacrylamide gel electrophoresis (PAGE), the enzyme migrated as a single band. The molecular weight of the native enzyme was 173,000 +/- 3,000, as determined by sedimentation equilibrium analysis, and that of the enzyme subunit was determined to be 50,000 +/- 1,500 by sodium dodecyl sulfate (SDS)-PAGE. Cross-linking experiments using dimethyl suberimidate followed by SDS-PAGE indicated that the native enzyme was composed of four subunits with identical molecular weight. The amino acid composition of the enzyme was determined.

Amino Acids↗
PubMed1984

Differential effect of cerebral ischemia on monoamine content of discrete brain regions of the Mongolian gerbil (Meriones unguiculatus).

The effect of bilateral cerebral ischemia on noradrenaline, dopamine, and serotonin concentrations in six brain regions (i.e., the cerebral cortex, striatum, hippocampus, midbrain-diencephalon, cerebellum, and pons-medulla oblongata) was examined in the gerbil stroke model. The relative changes in regional cerebral blood flow after bilateral common carotid occlusion were also assessed using the radioactive microsphere technique. At 1 h after bilateral carotid occlusion, a significant decrease of monoamine concentration was observed in the cerebral cortex, striatum, hippocampus, and midbrain-diencephalon whereas no significant change was detected in the cerebellum and pons-medulla oblongata. The fall in NA content was most prominent in the cerebral cortex and hippocampus and percentage reductions of dopamine and serotonin were greatest in the striatum and cerebral cortex, respectively. These results suggest that the monoamine neurons in various brain regions might have different vulnerabilities to ischemic insult and show no evidence of transtentorial diaschisis.

Animals↗
PubMed1983

Role of prostacyclin in the response of cerebral blood flow to CO2.

The prostacyclin (PGI2) formation in cerebral vessels, as reflected by the difference in concentration of internal carotid arterial and internal jugular venous radioimmunoassayed 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), was determined under normocapnic and hypercapnic conditions in 5 patients with mild cerebral thrombotic infarction. There was no evidence that endogenous PGI formation in cerebral vessels was stimulated at mild hypercapnia, while an increase of cerebral blood flow (CBF) induced by hypercapnia was observed. These results suggest that endogenous PGI2 may not be a mediator for the response of CBF to CO2.

6-Ketoprostaglandin F1 alpha↗
PubMedDate not supplied

Effect of small deep hemispheric infarction on the ipsilateral cortical blood flow in man.

The effect of small, deep ischemic lesions on the ipsilateral cortical circulation was investigated in 10 patients with persistent mild or moderate neurological deficits due to infarcts in the internal capsule. rCBF studies by the 133Xe intracarotid injection method were performed 14-180 days after the onset of the infarction. The rCBF functional image was made up from the data of 133Xe dynamic images measured by an Anger-type gamma camera and the rCBF values were calculated by the initial slope method. The average value of mean rCBFs (mCBF) in 10 patients was 44.9 +/- 7.1 ml/100g/min (average PaCO2; 39.9 +/- 4.3 mm Hg). In the rCBF functional images, a focal hypoperfusion area was observed in all cases and localized around the central sulcus, especially in the precentral and central areas. Significant decreases of mCBF and the tendency to decrease of the rCBFs in the hypoperfusion focus were noted in the patients with the larger infarcts in comparison with those with the smaller ones. These results suggest that a small, deep ischemic lesion such as a capsular infarct may have remote effects on the ipsilateral cortical circulation, due probably to the damage of a number of fibers passing through the lesion.

Adult↗