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Biomedical subjects

T Ando

Publications and source records attributed to T Ando.

At least 433 records · Page 24Linked to original sources
PubMed1991

Transcription stimulation of the adenovirus type-12 E1a gene in vitro by a novel factor bound to a region adjacent to a TATA box.

The E1a gene of adenovirus (Ad) type-12 possesses two transcription start points (tsp) separated by 139 nucleotides (nt). We previously found that transcription from a tsp distal to the coding region is preferentially stimulated in a cell-free reaction by nuclear factor I (NF-I) bound to a region near the left end of the virus genome. We report here on the identification of a cis-acting DNA region and a trans-acting factor for transcription initiated at the proximal tsp of the Ad12 E1a gene. A deletion in the region between nt -50 and -36 relative to the proximal tsp at +1 caused a significant decrease in the proximal transcription in a cell-free reaction using nuclear extracts of HeLa cells. A cellular factor binding to this region was shown to be responsible for transcription stimulation. This E1A-stimulating factor (ESF-1) appeared to recognize the sequence 5'-TGTCA-3' located immediately upstream from a TATA box. Unlike NF-I, the ESF-1 activity did not seem to be influenced by the E1A protein. Our results indicated that ESF-1 stimulates the proximal transcription of the Ad12 E1a gene by binding to the region adjacent to a TATA box.

Adenoviridae↗
PubMed1991

Sequence-specific complex formation of DNA and a eukaryotic sequence-specific endonuclease, SceI.

Endo.SceI is a eukaryotic sequence-specific endonuclease of 120 kDa that causes sequence-specific double-stranded scission of DNA. Unlike results with restriction enzymes, we found a consensus sequence around the cleavage sites for Endo.SceI instead of a common sequence. We searched for conditions for studying the binding of Endo.SceI to DNA other than cutting. Under optimized conditions including gel mobility shift assay, Endo.SceI exhibited sequence-specific binding to a short double-stranded DNA (41 base pairs) containing a cleavage site and the DNA reisolated from the protein-DNA complex was not cleaved. The analysis of the complex of Endo.SceI and DNA isolated by the gel mobility shift experiments showed that the DNA-binding entity in the Endo.SceI preparation does have Endo.SceI activity and consists of an equal amount of 75-kDa and 50-kDa polypeptides. Based on this observation and those from previous studies, we conclude that Endo.SceI is a heterodimer of the 75-kDa and 50-kDa subunits. Under the present assay conditions, Endo.SceI did not show binding to single-stranded DNA having the same sequence of either plus or minus strand of the double-stranded DNA containing the cleavage site (the 41-bp DNA). Endo.SceI showed significantly higher affinity for the consensus sequence than the major cleavage site in pBR322 DNA. Unlike the cleavage of DNA by Endo.SceI which requires Mg2+, this sequence-specific binding is independent of but stimulated by Mg2+.

Base Sequence↗
PubMed1991

Specific destruction of host-reactive mature T cells of donor origin prevents graft-versus-host disease in cyclophosphamide-induced tolerant mice.

In cyclophosphamide (CP)-induced tolerance, a long lasting skin allograft tolerance was established in many H-2-identical strain combinations without graft vs host disease. Destruction of donor-reactive T cells of host origin, followed by intrathymic clonal deletion of these cells, has been revealed to be the chief mechanisms of this system. Here, we studied the fate of host-reactive populations in donor-derived T cells of C3H/He (C3H) (H-2k, Mls-1b, Mls-2a) mice rendered CP-induced tolerant to AKR/J (AKR) (H-2k, Mls-1a, Mls-2b), by assessing AKR-derived Thy-1.1+ T cells bearing TCR V beta 3 that are specifically reactive with Mls-2a-encoded Ag of the recipient C3H mice. In the AKR-derived Thy-1.1+ lymph node cells of the C3H mice that had been treated with AKR spleen cells plus CP, CD4(+)-V beta 3+ T cells were obviously decreased by day 10 after the CP treatment. At this stage, the Thy-1.1+ T cells were not detected in the C3H thymus, suggesting that the obvious decrease of CD4(+)-V beta 3+ T cells of AKR origin was not due to intrathymic clonal deletion in the recipient C3H mice. Therefore, the destruction of the host-reactive mature T cells of donor origin, as well as that of the donor-reactive mature T cells of host origin, occurred by the CP treatment at the induction phase. Furthermore, after the establishment of intrathymic mixed chimerism in the recipient C3H mice, V beta 3+ T cells were not detected among the Thy-1.1+ T cells of AKR origin in the mixed chimeric thymus, suggesting that the host-reactive immature T cells repopulated from the injected donor hematopoietic cells were clonally deleted in the recipient thymus. These two mechanisms appear to prevent graft vs host disease in CP-induced tolerance.

Animals↗
PubMed1991

Intracellular Ca2+ changes in cultured vascular smooth muscle cells by treatment with various spasmogens.

In order to evaluate various spasmogens, which are candidates for cerebral vasospasm after subarachnoid haemorrhage, the intracellular calcium mobilizations were examined in cultured vascular smooth muscle cells preloaded with a fluorescent Ca2+ probe fura-2. Endothelin, oxyhaemoglobin, 5-hydroxytryptamine, norepinephrine, prostaglandin F2 alpha, leukotrienes C4 and D4 produced dose-dependent increases in intracellular Ca2+ concentration ([Ca2+]i). However, bilirubin did not induce any significant [Ca2+]i elevation. The maximal levels of [Ca2+]i peak attained by endothelin or oxyhaemoglobin were higher than those of other compounds. Endothelin was the most potent in that it induced a high sustained [Ca2+]i elevation at much lower concentrations compared with others. The combination of oxyhaemoglobin and endothelin induced a transient increase in [Ca2+]i followed by a sustained lower plateau, then the [Ca2+]i level was again increased slowly followed by a sustained higher plateau which lasted for more than 10 min after the exposure. These results suggest that endothelin and/or oxyhaemoglobin may play a crucial role in contraction of vascular smooth muscle after subarachnoid haemorrhage.

Animals↗
PubMed1991

Detection of viral DNA in neonatal herpes simplex virus infections: frequent and prolonged presence in serum and cerebrospinal fluid.

Polymerase chain reaction (PCR) assay was used to detect herpes simplex virus (HSV) DNA in mouth, skin, sera, or cerebrospinal fluid (CSF) from seven neonates with HSV infection. In a culture-negative patient, the diagnosis was confirmed by detection of HSV DNA. Serial examinations revealed that HSV DNA remained in the serum and/or CSF from several patients for 1-2 weeks after the beginning of treatment. Next, the results of PCR assay in neonatal HSV infections were compared with those in older children with herpes simplex encephalitis (HSE). HSV DNA was detected in CSF from four neonates with central nervous system involvement and in CSF from all nine children with HSE. Sera were positive for HSV DNA in five of seven neonates, including two cases of localized infections, but in none of the children with HSE. These results suggest that HSV may be spread principally via viremia in neonates. PCR assay could be useful for the confirmative diagnosis of neonatal HSV infections, especially in culture-negative cases.

Base Sequence↗
PubMed1991

Subunit composition of Photosystem I complex that catalyzes light-dependent transfer of electrons from plastocyanin to ferredoxin.

The PSI core complex prepared from cucumber cotyledons, which contains 80 chlorophylls per reaction center (P700) and eight polypeptides with apparent molecular masses of 65/63, 20, 19.5, 18.5, 17.5, 7.6, and 5.8 kDa, has been shown to catalyze the light-dependent transfer of electrons from plastocyanin to ferredoxin. The "native" PSI complex, which contains more than fifteen polypeptides and 120 chlorophylls per P700, did not show higher activity. Any attempt to deplete subunit(s) of the core complex decreased its activity. These results suggest that in addition to light-harvesting chlorophyll a/b protein complexes, several genes of psaA-psaK, which have been proposed as components of PSI complex, are not involved in the activity of PSI complex. It was also found that the amount of 18.5-kDa polypeptide in the PSI complex affects the activity: when this polypeptide was largely depleted, the complex was almost inactive. The inactivation was due to inhibition of electron transfer from plastocyanin to photooxidized P700. Chemical cross-linking and N-terminal amino acid sequencing experiments indicated that the 18.5-kDa polypeptide is the plastocyanin-docking protein and the psaF gene product. The function of the psaF gene product was discussed.

Darkness↗
PubMed1991

Giant hydroureteronephrosis associated with primary obstructed megaureter.

The case is presented of a four year old boy with a large left abdominal mass. The patient was diagnosed as having a left giant hydroureteronephrosis due to a primary obstructed megaureter, based on the findings of ultrasonography, micturating cystourethrography, excretion urography, computed tomography and percutaneous antegrade pyeloureterography. Diuretic renography showed that the obstruction was partial. Since a static renal scintigram indicated that renal function on the affected side was moderately well preserved, ureteroplasty is planned.

Child, Preschool↗
PubMed1991

Synthesis of biologically active recombinant Der f II.

A cDNA library corresponding to mite protein was screened employing anti-Der f II antibody. Two possible clones containing plasmids pFL1 and pFL11 were obtained. The two plasmids had insertions of about 500 basepairs. The DNA sequences of the two insertions were determined, from which the amino acid sequences were deduced. The amino acid sequence of the purified native Der f II protein could be determined to 45 residues from the N terminus. As a result of comparison, we concluded that the cDNAs prepared from live Dermatophagoides farinae mite corresponded to the mite allergen Der f II. The recombinant Der f II was biologically active.

Allergens↗
PubMed1991

Isolation of cysteine protease in the crude mite extract, Dermatophagoides farinae.

In order to study the relationship between cysteine protease and Der f I, which is one of the major allergens in the mite, Dermatophagoides farinae, isolation of cysteine protease was attempted using various column chromatographies. Both the potent cysteine protease activity and the allergenic activity were detected in the same fractions by anion exchange chromatography on a DEAE-Sephacel, gel chromatographies and chelating Sepharose 6B chromatography. In the double immunodiffusion test, the finally isolated fraction and rabbit anti-Der f I sera reacted to give a single precipitation line which fused completely with the precipitation line formed by Der f I and anti-Der f I sera. Sequence analysis for the first 10 N-terminal amino acids from cysteine protease and Der f I were identical. These results strongly suggest that cysteine protease of mites may be Der f I allergen and that measuring cysteine protease activity may possibly become a beneficial method for detecting Der f I allergens.

Allergens↗
PubMed1991

[Concordance of risk factors for cerebro-cardiovascular diseases among spouses].

The present study was carried out to clarify the concordance or similarity of risk factors among 298 spouse pairs in a random sample who lived in Mizobe town of Kagoshima Prefecture. A sample of 298 spouse pairs was surveyed by using the house-to-house interviewing method and was classified into three groups by the marriage duration. The following results were obtained. 1) Statistically significant partial correlation coefficients were demonstrated among the spouses for blood pressure in the present study. However, they were smaller than among spouses in remote islands, this fact suggested that there was no higher spouse concordance in this surveyed area than in remote island areas, and also that there might be a difference in the shared environment of spouse pairs and the genetic effect on blood pressure between the former area and the latter. 2) In regard to the intake of salt in miso soup and the ratio of sodium to potassium (Na/K), an increasing gradient of partial correlation coefficients for the risk factors among the spouses was observed with increasing marriage duration, suggesting that the intake might be caused by the shared environment on the basis of a similar dietary pattern for the spouse pairs.

Adult↗
PubMed1991

Breathing patterns during sleep in stable asthmatic children.

Breathing patterns during sleep at night were studied in 15 asymptomatic asthmatic children and 11 nonasthmatic controls using impedance pneumography. Inspiratory time (TI), expiratory time (TE) and expiratory time/inspiratory time ratio (TE/TI) were used as the indices of breathing patterns. In the daytime, TI, TE and TE/TI, showed no significant differences between asthmatics and controls. During nocturnal sleep, TE and TE/TI increased significantly in the asthmatics compared with the value during daytime, while these values showed only a small variation overnight in the controls. TI showed no significant changes through the night in either the asthmatics and the controls. The results of this study indicate that the stable asthmatic children had abnormal breathing patterns during nocturnal sleep.

Adolescent↗
PubMed1991

Familial occurrence of arteriovenous malformation of the brain.

Brain arteriovenous malformations are considered to originate from a congenital maldevelopment of the brain vessels. Although there have been occasional reports suggesting a familial incidence of these lesions, data for only 10 families have been accumulated in the literature. The authors report on six such cases in three families. This high rate of occurrence of familial cases suggests an involvement of genetic factors.

Adolescent↗
PubMed1991

Cytosolic calcium changes in cultured rat aortic smooth-muscle cells induced by oxyhemoglobin.

To clarify the mechanism of contractive effects in arteries caused by oxyhemoglobin, changes in the concentration of cytosolic calcium [( Ca++]i) before and after exposure to oxyhemoglobin were measured in vitro in cultured vascular smooth-muscle cells obtained from rat aorta. This was accomplished by preloading these cells with a fluorescent intracellular Ca++ probe fura-2/AM. Oxyhemoglobin induced a significant elevation of [Ca++]i in vascular smooth-muscle cells which was sustained for 10 minutes. This response was completely abolished by chelating extracellular calcium with ethyleneglycol-bis (beta-aminoethylether)-N,N'-tetra-acetic acid (EGTA). Oxyhemoglobin induced no accumulation of mass content of inositol 1,4,5-trisphosphate (IP3(1,4,5]. The oxyhemoglobin-induced elevation of [Ca++]i was not blocked by verapamil, a calcium antagonist. Serotonin induced a rapid, transient increase of [Ca++]i followed by a sustained elevation above baseline for 5 minutes. Additions of EGTA or verapamil had a small effect on the peak height of serotonin-induced [Ca++]i elevation, but the [Ca++]i level declined more quickly to the basal level in treated compared with control cells. These results indicate that oxyhemoglobin-induced [Ca++]i elevation is caused by the influx of extracellular calcium, which is independent of the verapamil-blocked voltage-gated calcium channel. The long-lasting high elevation of [Ca++]i caused by oxyhemoglobin suggests that oxyhemoglobin may contribute to the production of abnormal contractions and/or irreversible damage in vascular smooth-muscle cells.

Animals↗
PubMed1991

Induction of cytosolic free calcium elevation in rat vascular smooth-muscle cells by cerebrospinal fluid from patients after subarachnoid hemorrhage.

The purpose of this study was to determine the effects of cerebrospinal fluid (CSF) from patients with subarachnoid hemorrhage (SAH) on cytosolic free calcium in cultured rat vascular smooth-muscle cells using the fluorescent intracellular calcium indicator fura-2/AM. Samples of CSF were collected from 12 patients (seven with and five without vasospasm) on Days 2, 6, 11, and 16 after SAH. Control CSF samples were obtained from five patients 6 to 9 months after they had undergone successful aneurysm surgery following an SAH. All CSF samples in both the non-vasospasm and vasospasm groups, regardless of the day of sampling after the SAH, induced significantly higher transient intracellular calcium elevations when compared to levels induced by control CSF. Furthermore, the addition of 2 mM ethyleneglycol-bis (beta-aminoethylether)-N,N'-tetra-acetic acid (EGTA) caused a slight reduction in the peak height in the CSF-induced intracellular calcium rise which declined more rapidly to basal levels than those studied without EGTA. In the non-vasospasm group, the intracellular calcium concentration remained stable after SAH throughout the study period. In contrast, in the vasospasm group, this concentration was highest on Day 2 post-SAH, but sharply decreased on Day 6 and rose again on Day 11. This result correlated with the clinical signs of vasospasm in these patients. These findings indicated that the intracellular calcium elevations induced by CSF obtained after SAH were due to the combination of the influx of extracellular calcium and the mobilization of intracellular calcium from storage sites. The changes in intracellular calcium concentrations in vascular smooth-muscle cells induced by CSF obtained from patients on successive days following SAH suggest that the substances that induce this repeat calcium elevation on Day 11 post-SAH may be the key spasmogens for vasospasm after SAH.

Animals↗