Search PubMed⌕ Search

Biomedical subjects

A Adachi

Publications and source records attributed to A Adachi.

At least 91 records · Page 5Linked to original sources
PubMed1999

Growth characteristics of T-cell tropic HIV-1 vpu gene mutants in human peripheral blood mononuclear cells.

A mutant designated NL-E65, which lacks the expression of entire vpu gene, was constructed from T-cell tropic wild-type (wt) human immunodeficiency virus type 1 (HIV-1) clone and monitored for its replication property in human cells, along with a mutant NL-Ss which expresses a C-terminal truncated Vpu. The mutant NL-Ss could grow in two cell lines and in all peripheral blood mononuclear cell (PBMC) preparations to some extent, with kinetics similar to those of wt virus. Likewise, the mutant NL-E65 exhibited a replication property typical to the vpu mutant in the two cell lines and in all PBMC cultures, growing at a low level. Along with the results previously reported, these data indicate that HIV-1 Vpu is dispensable for virus replication in any of the types of cells so far tested.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Numerous huge iron particles appeared around micro blood vessels under intestinal epithelial cells in infant mice fed excess iron with protein.

In infant mice (2 weeks old) fed a diet with excess iron for one week, numerous huge iron particles around micro blood vessels under the basement membrane of intestinal epithelial cells were observed by electron microscopy. The frequency of occurrence of these particles (0.24 +/- 0.04 micron diameter) was markedly higher in mice fed a casein-based diet than in mice fed an amino acid-based diet. The quantity of these particles in both groups decreased in proportion to the term of 2 or 3 weeks. Changes in morphological features, such as opening of the intercellular junctions between intestinal epithelial cells, were also observed in these experimental groups. On the other hand, in mice fed the casein-based diet with excess iron, fat globules appeared in the intestinal epithelial tissue (intestinal epithelial cells, interstitial tissue, lympha) and the occurrence of these increased gradually in proportion to the term of feeding. These fat globules were not observed in mice fed the amino acid-based diet with excess iron. These phenomena might be elicited temporally in infant mice fed excess iron together with protein. The mechanisms of fat globule formation remain unclear.

Amino Acids↗
PubMed1999

[Role of Candida allergen in atopic dermatitis and efficacy of oral therapy with various antifungal agents].

We studied whether fungal allergens play a role in exacerbating the clinical symptoms of atopic dermatitis (AD). We found that the percentage of the patients who showed CAP-RAST positive (2 < or = score) to Candida albicans (Ca) was significantly higher in the patients with severe symptoms and high serum IgE level than those with mild symptoms and lower IgE. This was also true for the patients with CAP-RAST positive to Pityrosporum ovale (Po). AD patients with their symptoms localized to head and neck showed significantly higher tendency to have positive CAP-RAST (2 < or = score) to Ca and Po when compared to those with their eruption distributing to the extremities. We then evaluated the efficacy of oral therapy with antifungal agents in 140 cases of refractory AD with positive CAP-RAST to Ca. Good or excellent response was obtained in 60% with fluconazole, 35% with itraconazole, 31% with amphotericin B, 28% with nystatin. The present finding that amphotericin B and nystatin, both of which are not absorbed through intestine, were effective for approximately a third of the patients indicates that Ca in the intestine plays an important role in triggering AD symptoms. Fluconazole was more effective than amphotericin B and nystatin, suggesting that fungal colonizing in other parts of the body but the digestive tract also play a role in the exacerbation of AD symptoms.

Administration, Oral↗
PubMed1998

Studies on removal efficiency of chloroform from tap water by rice bran.

Removal efficiency of chloroform from tap water by rice bran was investigated. The adsorption rate by rice bran was similar to activated carbon. The amount of chloroform adsorbed was plotted against the equilibrium concentration of chloroform in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reaction was a Freundlich type. The adsorption of chloroform by rice bran was observed in the range of pH 1-11. Chloroform was successfully removed from tap water with average removal efficiency of 70% after 60 min when rice bran was applied to tap water that contained 0.0064 mg/L chloroform.

Adsorption↗
PubMed1998

Facilitation of gastric motility induced by portal infusion of hyper- and hypotonic solution in rats.

The effects of the portal infusion of hyper- and hypotonic solution on gastric motility in rats were investigated. The infusion of hypertonic saline into the portal vein (portal infusion) elicited a significant enhancement of gastric contractile activity. The portal infusion of water also produced this enhancement. However, the portal infusion of isotonic saline showed no significant enhancement; nor did the infusion of water and hypertonic saline into the jugular vein. Sectioning of the hepatic branch of the vagus nerve (hepatic vagus) eliminated the enhanced responses of the gastric motility. It is therefore concluded that hepatoportal osmoreceptive afferent signals affect the gastric motility by way of the hepatic vagus. These effects on osmolarity revealed that hypotonic stimulation is more effective than hypertonic stimulation for the enhancement of motility. Sectioning of the dorsal subdiaphragmatic vagus, which includes the dorsal gastric and celiac branch, did not eliminate these responses. Sectioning of the ventral gastric vagus, in contrast, did eliminate the responses. These results suggest that vagal preganglionic neurons in the left dorsal motor nucleus of the vagus play a role in enhancement of gastric motility observed in the present research.

Animals↗
PubMed1998

Producer cell-dependent requirement of the Nef protein for efficient entry of HIV-1 into cells.

A proviral nef gene mutant of human immunodeficiency virus type 1 (HIV-1) was evaluated for its defective early replication step. Virus stocks were prepared from six CD4-positive and -negative cell lines transfected with wild-type (wt) or the nef mutant clone and inoculated into two target CD4-positive cell lines to monitor the efficiency of viral entry process. The nef mutant virions produced in one cell line exhibited a severe defect in the entry process, although those produced in the other five cell lines were only slightly less efficient than the wt virions at entering into cells. These results have demonstrated that the HIV-1 Nef is critical for efficient viral entry in a producer cell-dependent manner.

CD4-Positive T-Lymphocytes↗
PubMed1998

Cloning and characterization of human MCM7 promoter.

MCM7 is a member of the MCM protein family which has been implicated in the regulatory machinery allowing DNA to replicate only once during S phase. In quiescent cells, human MCM7 (hMCM7) mRNA is almost undetectable. Stimulation of cells to enter the cell cycle results in induction of hMCM7 expression. Here, we report cloning and characterization of the hMCM7 promoter. We isolated and sequenced a 0.5 kb genomic fragment that contains putative transcription factor binding sites including three E2F sites, three GC boxes and an E box. Several transcription start sites, which were used upon growth stimulation, were identified. The minimal promoter region required for transcription of a luciferase reporter gene was delineated, and it contained an E box and one E2F site, which were important for promoter activity. Interestingly, the cloned sequence appears to act as a promoter for mu-adaptin-related protein 2 (mu-ARP2) gene in the opposite orientation.

Base Sequence↗
PubMed1998

The HIV-1 Vpr displays strong anti-apoptotic activity.

Mutations in the human immunodeficiency virus type 1 (HIV-1) vpr gene only slightly reduce the replication rate of the virus. To study the role of HIV-1 Vpr in biological effects on cells, HEp-2 cells, which express HIV-1 Vpr constitutively but at a low level, were established. While control HEp-2 cells underwent apoptosis when incubated with sorbitol, the morphological and biochemical apoptotic changes were inefficiently induced in the HIV-1 Vpr-expressing cells by the same treatment. These results clearly indicate that HIV-1 Vpr has anti-apoptotic activity, and raise the possibility that Vpr acts as a weak activator of virus replication through anti-apoptosis.

Animals↗
PubMed1998

Early function of HIV-1 Gag proteins is cell-dependent.

Various gag gene mutants of human immunodeficiency virus type 1 (HIV-1) were monitored for their replication potentials and defective replication sites in various CD4-positive T-cell lines. Some matrix, capsid, and nucleocapsid mutants displayed a replication defect in a cell-dependent manner. The single-round replication assays demonstrated that these mutants were defective at an early infection phase also in a cell-dependent way. These results indicated that interaction of a cell factor(s) and Gag proteins is involved in an early process of HIV-1 replication.

CD4-Positive T-Lymphocytes↗
PubMed1998

Suppression of HIV-2 replication by HIV-1 gag mutants.

Gag gene mutants of human immunodeficiency virus type 1 (HIV-1) were analyzed for their potentials of inhibiting the replication of wild-type (wt) HIV-2, the second AIDS virus, in a single-round of viral replication. Of twenty-two HIV-1 gag mutants examined, seven were found to efficiently interfere with the replication of wt HIV-2. Some mutants, which can suppress the replication of wt HIV-1, did not show this inhibitory effect. These mutants were defective at the late phase of viral replication. A mutant designated NL-C1a was demonstrated to be very effective against the replication of HIV-1 and HIV-2 in monocytic cells as well as in lymphocytic cells.

CD4-Positive T-Lymphocytes↗
PubMed1998

The potential of various HIV-1 mutants to inhibit the replication of wild-type virus.

We have previously demonstrated that many of gag mutants of human immunodeficiency virus type 1 (HIV-1) inhibited the replication of wild-type (wt) HIV-1. In this study, various HIV-1 mutants were systematically analyzed with respect to their ability to suppress the replication of wt HIV-1. Sixteen mutants of all eight HIV-1 genes other than gag were evaluated for their inhibitory effects. Only an env mutant designated NL-Hi efficiently interfered with the replication of wt HIV-1 in a single round of infection. The NL-Hi did not affect the late replication processes of wt virus, including transcription, translation, and assembly/release. Virions produced in the presence of the mutant Env were defective for the viral entry process in the early phase of HIV-1 replication cycle.

Cell Line↗
PubMed1998

Nuclear access and action of notch in vivo.

The Drosophila Notch (N) gene encodes a conserved single-pass transmembrane receptor that transduces extracellular signals controlling cell fate. Here, we present evidence that the intracellular domain of Notch gains access to the nucleus in response to ligand, possibly through a mechanism involving proteolytic cleavage and release from the remainder of the protein. In addition, our results suggest that signal transduction by Notch depends on the ability of the intracellular domain, particularly the portion containing the CDC10 repeats, to reach the nucleus and to participate in the transcriptional activation of downstream target genes.

Animals↗
PubMed1998

Phase-relationship and mutual effects between circadian rhythms of ocular melatonin and dopamine in the pigeon.

In order to study the mechanisms of ocular circadian rhythms in the pigeon, we measured melatonin and dopamine simultaneously from the eye using in vivo microdialysis. In experiment 1, the phase relationship between circadian rhythms of ocular melatonin and dopamine under light-dark cycles (LD) and continuous dim light (LLdim) was examined. Under LD, melatonin was high during the dark and low during the light. On the other hand dopamine was high during the light and low during the dark. These rhythms with the anti-phase relationship were maintained after the birds were transferred from LD to LLdim. In experiment 2, effects of a single light pulse on melatonin and dopamine rhythms were examined. A light pulse at CT18 rapidly suppressed melatonin release to the daytime level, whereas it rapidly increased dopamine release to the daytime level. The light pulse also affected the phases of melatonin and dopamine rhythms, inducing phase advances of both rhythm without changing the anti-phase relationship before the light pulse. In experiment 3, effects of an intraocular injection of dopamine or melatonin on their circadian rhythms were examined. A dopamine injection during the subjective night suppressed melatonin release and induced a light-pulse type phase shift in both melatonin and dopamine rhythms. On the other hand, a melatonin injection during the subjective day suppressed dopamine release and induced a dark-pulse type phase shift. These results are compatible with either one or two oscillator models, but the interaction between melatonin and dopamine is, in either case considered as an important mechanism regulating ocular circadian rhythms of the pigeon.

Animals↗
PubMed1998

Induction of MHC-IIDR expression on circulating CD8+ lymphocytes in macaques infected with SIVmac239 nef-open but not with its nef-deletion mutant.

We examined the expression kinetics of activation antigens CD38 and MHC-IIDR (DR) on circulating CD8+ lymphocytes in rhesus macaques infected with pathogenic simian immunodeficiency virus strain SIVmac239 nef-open (239) or its nonpathogenic nef-deletion mutant (delta nef). In the longitudinal study, we found for the first time the induction of DR expression on CD8+ lymphocytes in 239-infected macaques. The induction of DR was in parallel with an increasing viral load and a decreasing CD4+ lymphocyte level. In the macaques with the high viral load and low CD4 level, a considerable proportion of the DR+CD8+ subpopulation was CD69+, indicating an activated state. On the other hand, no significant increase in the DR+CD8+ subpopulation level was observed in delta nef-infected macaques. These data indicate that the evaluation of activation markers such as DR and/or CD69 on circulating CD8+ cells may be valuable as a surrogate marker in the SIV-macaque model.

ADP-ribosyl Cyclase↗
PubMed1998

Acceleration of virus-induced apoptosis by tumor necrosis factor.

The multiplication of vesicular stomatitis virus in HeLa cells was inhibited by treating the cells with tumor necrosis factor (TNF). Comparison of the kinetics of virus multiplication and that of virus-induced apoptosis in the TNF-treated cells revealed that the antiviral effect of TNF is accompanied by a rapid induction of apoptosis in the cells upon infection, suggesting that TNF can inhibit virus multiplication by accelerating an apoptotic response in the infected cells.

Antiviral Agents↗
PubMed1998

Selective expression of beta 7 integrin on lymphocytes undergoing apoptosis in lymphoid tissues.

It has been previously shown that the beta 7 chain of integrin forms heterodimers with the alpha 4 or alpha E chain, which plays essential roles in lymphocyte homing to mucosal lymphoid tissues. The aim of this study was to re-evaluate the possible role of the beta 7 integrin other than lymphocyte homing. We prepared spleen and lymph node lymphocytes from biopsied specimens from macaque monkeys and examined for the reactivity with a monoclonal antibody specific for the beta 7 chain. As a result, a minor population of the lymphocytes with a smaller size, which were in the early stage of apoptosis, was found to express a higher level of the beta 7 integrin than a majority of the lymphocytes with a normal size. Interestingly, the apoptotic lymphocytes expressed neither alpha 4 nor alpha E chains, suggesting that the beta 7 chain on these cells may be associated with an undefined alpha chain. These findings indicate that in the lymphoid tissues the shrunken lymphocytes undergoing apoptosis selectively express a unique beta 7 integrin.

Animals↗
PubMed1998

Identification of rhodopsin in the pigeon deep brain.

We detected rhodopsin gene expression in the pigeon lateral septum, a photosensitive deep brain region that is responsible for the photoperiodic gonadal response. The nucleotide sequence of the deep brain rhodopsin cDNA clone exactly matched that of the retinal one, indicating that a single rhodopsin gene is transcribed in the two tissues. Immunohistochemical analysis localized rhodopsin in the cerebrospinal fluid-contacting neurons, which have been assumed to be photoreceptive cells in the deep brain. Pigeon rhodopsin seems to play dual important roles in the visual and non-visual systems, the latter of which contributes to the photoperiodic response.

Amino Acid Sequence↗