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Biomedical subjects

H Handa

Publications and source records attributed to H Handa.

At least 199 records · Page 11Linked to original sources
PubMed1992

Cooperative transcription activation between Ad1, a CRE-like element, and other elements in the CYP11B gene promoter.

We previously reported the presence of six different cis-acting elements (Ad1 to Ad6) in the promoter region of the bovine CYP11B gene. Although the Ad1 site (TGACGTGA) was similar to a palindromic CRE (TGACGTCA), two other upstream sequences, Ad3 and Ad4, were identified as the cAMP response sequences of the gene. We analyzed the functional relationship between the Ad1 site and the upstream elements. Mutation analyses of the Ad1 site indicated that the 5' half of the site (TGACG) was important for the transcription of the gene in vitro. In Y-1 cells, a plasmid with a mutated Ad1 showed no response to cAMP. The effect of the mutation at the Ad1 site on the cAMP response was almost the same as that of the deletion of Ad3 and Ad4, although the role of each element seemed to be different. These results indicated that both the Ad1 site and the upstream elements, Ad3 and Ad4, were necessary for the full response to cAMP of the CYP11B gene. When the Ad1 site in the promoter region was replaced with a palindromic CRE, elevated transcription activity was detected both in vitro and in vivo. Two kinds of CREBs (43 and 47 kDa) purified from a HeLa cell nuclear extract bound to the Ad1 site. The binding of the palindromic CRE to the nuclear factor(s) was stronger than that of Ad1.

Animals↗
PubMed1992

Aneurysm arising at the triplicate anterior communicating artery--case report.

A very rare case of triplicate anterior communicating artery associated with ruptured aneurysm in a 21-year-old female is reported. The triplicate configuration was not predicted by preoperative cerebral angiography, but found intraoperatively. The aneurysm was trapped successfully, and she recovered with no neurological deficit.

Adult↗
PubMed1992

Action of a novel kinin precursor, Met-T-kinin-Leu, on prostaglandin I2 and blood pressure.

The novel kinin precursor, Met-T-kinin-Leu, stimulated the release of prostaglandin I2 from endothelial cells cultured using bovine carotid artery endothelial cells and minimum essential medium supplemented with 10% fetal calf serum. However, it failed to stimulate the release of prostaglandin I2 from the cells in the fetal calf serum-free medium conditions. To examine the discrepancy of the release of prostaglandin I2 from the cells by Met-T-kinin-Leu in the presence or absence of fetal calf serum, the products formed from Met-T-kinin-Leu by incubation of culture medium were analyzed by reverse-phase HPLC. Regarding the blood pressure reaction of Met-T-kinin-Leu, it showed from one fifth to one hundredth of that compared with bradykinin in blood pressure reactivity of each species, such as rats, rabbits and cats.

Animals↗
PubMed1992

Changes in polymorphonuclear neutrophil-elastase in pancreatitis.

In cases of acute and chronic pancreatitis, we measured the amount of polymorphonuclear neutrophil (PMN)-elastase. There was a significantly larger increase in PMN-elastase in patients with pancreatitis than normal adults. Especially, there was a particularly notable increase in amount of PMN-elastase in patients with severe pancreatitis. Furthermore, the peak of PMN-elastase increase throughout the course of the pancreatitis was seen to be 1-2 days after peak increase in pancreatic enzymes. In the experiment in which pancreatic juice and pig pancreatic kallikrein were added to granulocytes in vitro, we recognized a gradual release of PMN-elastase. From these data, we suggested that timely measurements of PMN-elastase are useful to marker of monitoring clinical changes in severe pancreatitis.

Acute Disease↗
PubMed1991

Monoclonal antibody-mediated solid-phase assay for mammalian O6-alkylguanine DNA alkyltransferase activity.

We describe a sensitive, rapid, and simple assay for mammalian O6-alkylguanine DNA alkyltransferase (O6-AGT) utilizing solid-phase DNA as the substrate and a monoclonal antibody (Mab)-based immuno-slotblot (ISB) for quantitation of O6-ethylguanine (O6-EtG). lambda-phage DNA was treated with N-ethyl-N-nitrosourea and immobilized on newly developed hydrophilic latex beads. After incubation with cell extracts to be assayed for O6-AGT activity, the substrate DNA could be isolated easily by a brief centrifugation through 50% glycerol. The amount of O6-EtG retained in the substrate DNA was determined by ISB using the anti-(O6-ethyl-2'-deoxyguanosine) Mab ER-6. As little as 2 fmol of O6-AGT per reaction tube can be reproducibly measured by this procedure, which is suitable for handling large numbers of samples within a short time (e.g., 80 samples within 2 days). In normal and malignant cells, respectively, O6-AGT activity protects against O6-alkylguanine-mediated mutagenesis and oncogenesis following exposure to N-nitroso carcinogens or confers resistance against cytocidal anti-cancer drugs such as chloroethylnitrosoureas and related compounds. The analysis of cellular O6-AGT activity by a highly sensitive, routinely applicable method is, therefore, of particular interest in studies related to carcinogenesis, molecular epidemiology, and clinical oncology.

Animals↗
PubMed1991

Vitamin E inhibits PGE2 and O2- production in rat peritoneal macrophages.

In order to examine the possible role of vitamin E on the modulation of macrophages, we investigated the effect of vitamin E on O2- and PGE2 production in macrophages. The production of both PGE2 and O2- in rat peritoneal macrophages was dose-dependently stimulated by the addition of PMA and calcium ionophore A23187. However, the macrophages obtained after intraperitoneal injection of vitamin E for six successive days showed less PGE2 and O2- production when stimulated with PMA or A23187 as compared to those of control macrophages. O2- production in control macrophages stimulated with 139 nM PMA and 1 microM A23187 as 4.2 +/- 0.3 and 3.0 +/- 0.2 nmol/min per 10(6) cells, respectively. On the other hand, O2- production by the macrophages from vitamin E-treated rats was 1.5 +/- 0.4 nmol/min per 10(6) cells when stimulated with the PMA, and was not detectable when stimulated with A23187. As for the production of PGE2, control macrophages produced 2.59 +/- 0.70 ng/30 min per 10(6) cells when stimulated with PMA and 8.96 +/- 3.26 ng/30 min per 10(6) cells with the A23187, whereas PGE2 production by the macrophages from vitamin E-treated rats was reduced to 12-20% of the control. By analyzing alpha-tocopherol content and intracellular concentration of calcium ion [( Ca2+]i) in the macrophages isolated from control and vitamin E-treated rats, vitamin E treatment augmented alpha-tocopherol content (384.7 +/- 76.1 vs. 1.2 +/- 0.4 ng/10(6) cells) and decreased free [Ca2+]i when stimulated with A23187 (652 +/- 14 vs. 1201 +/- 223 nM).

Animals↗
PubMed1991

Negative supercoiling of DNA facilitates an interaction between transcription factor IID and the fibroin gene promoter.

Transcription of the fibroin gene can be reconstituted with partially purified components from HeLa cells. Transcription factors IIB, IID, and IIE and RNA polymerase II are required for accurate initiation of transcription. Linear and relaxed closed circular DNA show a similar level of template activity. However, transcription of closed circular DNA is stimulated when negative supercoils are introduced by the addition of DNA topoisomerase II and supercoiling factor purified from the posterior silk gland of Bombyx mori. Dissection of transcription into pre- and postinitiation steps by the use of Sarkosyl reveals that DNA supercoiling promotes formation of a preinitiation complex. Furthermore, order of addition experiments suggest that DNA supercoiling facilitates a functional binding of transcription factor IID to the promoter.

Cell Nucleus↗
PubMed1991

Affinity purification of transcription factor IIA from HeLa cell nuclear extracts.

One of the general transcription factors, TFIIA, was purified to homogeneity from HeLa cell nuclear extracts by yeast TFIID affinity chromatography. Human TFIIA had a molecular weight of approximately 38 kd. It was able to associate with the complex formed by yeast TFIID and the TATA elements of the adenovirus E4 and ML promoters, and the HSP70 promoter. The association extended the protected region on each TATA element by yeast TFIID from DNase I digestion. Affinity-purified TFIIA was also able to stimulate transcription from the E4 and ML promoters in in vitro reconstituted systems.

Adenoviridae↗
PubMed1991

Establishment of a variety of human bone marrow stromal cell lines by the recombinant SV40-adenovirus vector.

Various human bone marrow stromal cell lines were established from the adherent cell populations by introduction of the recombinant SV40-adenovirus vector with an infection or electric poration procedure. As compared with DNA transfection, the vector introduction was able to immortalize the cells with more than 100 times higher efficiency. Morphological and cytochemical analyses indicated that various cloned cell lines with different properties were isolated by the vector introduction. All the established cell lines expressed SV40 large T antigen. These results provided the evidence indicating that the recombinant SV40-adenovirus vector was a useful tool to establish a variety of cell lines with different biological activities from human bone marrow stroma.

Adenoviridae↗
PubMed1991

E1A gene products stimulate in vitro transcription from the adenovirus early region 4 promoter by enhancing a stable preinitiation complex.

A cell-free transcription system using nuclear extracts prepared from adenovirus type 5 (Ad5)-infected and mock-infected cells were utilized to study the E1A-mediated transactivation of transcription from the Ad5 early region 4 (E4) promoter. The transcription activity of Ad-infected cell extracts was several times higher than that of mock-infected cell extracts when the E4 wild-type (WT) promoter was used. The increased activity required expression of E1A proteins. However, the transcription activities of both cell extracts were not different when the mutant promoter containing only the E4 TATA box was used. The formation of a stable preinitiation complex at the E4 WT promoter was facilitated by expression of E1A, whereas it was not facilitated at the mutant promoter. The results suggested that the E1A proteins stimulated transcription from the E4 promoter by enhancing the formation of a stable preinitiation complex through the upstream elements, together with the TATA box.

Adenovirus Early Proteins↗
PubMed1991

Different biological activities of the hetero- and homodimers formed by the 47- and 43-kilodalton proteins of transcription factor ATF/E4TF3.

The transcription factor ATF/E4TF3 stimulates transcription from the adenovirus early region 4 (E4) promoter by binding to specific promoter elements. Among the multiple forms of ATF/E4TF3, two forms with molecular masses of 47 and 43 kDa, which are most active in transcription in vitro from the E4 promoter, have been purified to homogeneity from HeLa cells by sequence-specific DNA affinity chromatography and biochemically characterized. Each purified protein formed a homodimer. These two homodimers were easily altered into a heterodimer when mixed together in the absence, but not in the presence, of the specific DNA sequence. All of these dimers were able to activate transcription in vitro from the E4 promoter by binding to the specific DNA sequence. Their activities to bind to DNA or stimulate transcription were different. The ability of the 47-kDa homodimer to stimulate transcription in vitro from the E4 promoter was approximately nine and three times higher than the abilities of the 43 kDa homodimer and the heterodimer, respectively, at the same level of DNA-binding activity. However, the affinity of the 47-kDa homodimer for DNA was lower than that of the 43-kDa homodimer, and the heterodimer had intermediate affinity. These results are the first to show differential binding and transcriptional activation activities of the different dimers of ATF/E4TF3, using purified cellular proteins rather than cloned gene products.

Activating Transcription Factors↗
PubMed1991

Rotatostereoradiography: a new radiodiagnostic method--development of a new three-dimensional radiodiagnostic device and evaluation in neurosurgical clinics.

The rotatostereoradiographic device uses an x-ray tube coupled with an image intensifier rotating through a 180 degree arc in 2.25 seconds. The rapidly rotating x-ray tube allows 180 degree-arc angiograms to be obtained with a single injection of contrast medium. Subtracted fluoroscopic angiograms can be viewed immediately after injection of the contrast medium with digital recording. These three-dimensional images are displayed on side-by-side monitors stereoscopically. The mortality and morbidity of subarachnoid hemorrhage can only be greatly reduced by surgical treatment of unruptured aneurysms and arteriovenous malformations detected by a wide survey of subarachnoid hemorrhage. Such a wide survey would be possible utilizing intra-arterial digital subtraction angiography via the ascending aorta and this new three-dimensional radiodiagnostic method. A fluoroscopic device must be used to allow easier manipulation of the catheter from the axillary or brachial artery.

Adult↗
PubMed1991

[Ventricular dilation during the treatment of subdural hygromas].

Fifty-one cases with subdural hygroma experienced in the past 20 years were retrospectively reviewed. Eight patients showed definite ventricular dilation differing from simple restoration of the ventricles following disappearance of the cavity. The mean age was 72.4 years. Six patients presented with mental change as the initial symptom. On the initial computed tomography (CT), 75% of the cases had bilateral lesions, all were low density, and 88% were crescent shaped. Trepanation performed on six patients yielded watery clear or xanthochromic fluid. Nine to 61 days (mean 4 weeks) after admission, definite ventricular dilation was observed. Cisternography performed in four patients was all abnormal, although cerebrospinal fluid (CSF) pressure was within normal range. Cerebral blood flow images using 123I-iodoamphetamine and single photon emission CT in four patients revealed periventricular low uptake which was disproportionately large compared with the ventricular span on CT. A ventriculoperitoneal shunt was placed in four patients. The final outcome, however, was poor irrespective of treatment. These findings indicate that an impairment of the CSF circulation was not the sole cause of the ventricular dilation. Low CSF pressure and the disproportionately large periventricular low perfusion, compared with the ventricular span on CT scan, suggest a pre-existing periventricular parenchymal damage, which had been subsequently compromised by the presence of subdural mass lesion. Therefore, attention should be paid in aged patients with bilateral low dense, crescent-shaped subdural hygroma, presenting with mental change, for the risk of subsequent ventricular dilation which may affect the functional outcome.

Aged↗
PubMed1991

[Acoustical analysis of occlusal sound--transfer functions of oral cavities and characteristics of waveform of occlusal sound].

The purpose of this study is to clarify the acoustical characteristics of the occlusal sound. An FFT analyzer was used to analyze the transfer functions of the oral cavities. The characteristics of the waveform of the occlusal sound were investigated by the time-frequency analysis. The results obtained were as follows: (1) There were three peaks in the low frequency area of the transfer functions of the oral cavities. The duration of the impulse responses of the oral cavities had a wide variation among the individuals. (2) The waveform of the occlusal sound by air-conduction was proved to consist of two components. One was the teeth collision sound produced by the collision of the teeth in the oral cavity and emitted directly out from the oral cavity. The other was the reverberation considered to be formed mainly by the resonance system in the oral cavity. (3) By the time-frequency analysis, the teeth collision sound could be distinguished clearly from the reverberation; the former was recognized as the component where the energy existed up to the high frequency area, while the latter was recognized as the component where the energy existed only in the low frequency area. (4) It was suggested that the teeth collision sound, after separating from the reverberation, should be analyzed for the purpose of obtaining further information about the functional condition of the occlusion from the occlusal sound.

Adult↗