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Biomedical subjects

T Tabata

Publications and source records attributed to T Tabata.

At least 271 records · Page 15Linked to original sources
PubMed1989

Cycloheximide-resistant gene of Epstein-Barr virus in freshly infected B lymphocytes.

The transcription of latent Epstein-Barr viral (EBV) genes, i.e., genes encoding EBNA-1, EBNA-2, EBNA-3A, -3B, -3C, and LMP, were detected in human tonsillar lymphocytes early after infection with EBV. Transcription of the BHLF-1 open reading frame was also detected at this initial phase of immortalization. Cycloheximide treatment inhibited the transcription of all the latent EBV genes but not BHLF-1. These results suggest that BHLF-1 might be considered an immediate-early gene of EBV. Cycloheximide treatment of EBV-infected cells reduced not only the degree of the transcription but also the size of the transcript for EBNA-2. We hypothesize that the immediate-early expression of BHLF-1 may be required for the enhanced transcription of the viral genes in lymphocytes early after infection with EBV.

Antigens, Viral↗
PubMed1989

Expression of EBNA-3 family in fresh B lymphocytes infected with Epstein-Barr virus.

Four transcripts belonging to the EBNA-3 family were detected during immortalization of human tonsillar lymphocytes with the Epstein-Barr virus. These four transcripts were also detected in immortalized B-lymphoblastoid cells (LCL) and the Burkitt's lymphoma cell line, Namalwa. A 5.0-kb transcript hybridized with the EBNA-3A probe; a 8.5-kb transcript hybridized with the EBNA-3B and -3C probes; and a 5.6- and a 3.6-kb transcript hybridized with the EBNA-3C probe. Sequencing and cDNA analysis showed that the EBNA-3C transcripts contained exons of the most rightward BamHI-E open reading frames, BERF-3 and BERF-4. Moreover, sequencing of cDNA clones revealed exons in the 5' portion homologous to regions in EBV BamHI-C, -W, and -U. Hybridization experiments with EBV BamHI-W and -U probes identified the 8.5- and 5.6-kb transcripts but not the 3.6-kb transcript in LCL. Organization of these transcripts from the EBNA-3 family is discussed.

Antigens, Viral↗
PubMed1989

Physiological properties of sensory trigeminal neurons projecting to mesencephalic parabrachial area in the cat.

1. One hundred forty-one trigeminomesencephalic neurons in the sensory trigeminal nucleus of cats anesthetized with alpha-chloralose were identified by antidromic stimulation of the mesencephalic parabrachial area (PBA) which includes the nucleus cuneiformis, lateral periaqueductal gray matter, and the region between the inferior colliculus and brachium conjunctivum. 2. Neurons were categorized based on their responses to non-noxious and noxious mechanical and heat stimuli delivered to their peripheral receptive fields (RFs) including skin, mucosa, guard hairs, vibrissae, cornea, and tooth pulps. They were classified into three types: 48 nociceptive-specific (NS) neurons which responded to heavy pressure and/or noxious mechanical stimuli, and/or noxious radiant heat; 19 wide dynamic range (WDR) neurons which had a graded response to light tactile stimuli, noxious pinch, and/or noxious radiant heat; and 36 low-threshold mechanoreceptive (LTM) neurons which responded maximally to innocuous tactile stimuli. In subnucleus caudalis (Vc), NS and WDR neurons were the majority (75%) among the three types, while in the rostral subnuclei they were about one-half (54%) of the population. 3. The RFs were distributed over the orofacial and head region but mainly in the facial region. Twelve neurons (33% of the LTM neurons) responded to deflection of vibrissae and only 1 NS neuron out of 52 NS and WDR neurons tested responded to electrical stimulation of a tooth pulp. 4. A contralateral projection was dominant (57%), 30% projected ipsilaterally and 13% projected bilaterally.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Clinical availability of serum fructosamine measurement in diabetic patients with uremia. Use as a glycemic index in uremic diabetes.

Serum fructosamine levels were investigated in patients with uremia undergoing various modes of treatment. The serum fructosamine levels correlated positively with the blood glucose levels determined a week or two earlier. The fructosamine levels were significantly affected by the protein concentration, and those corrected for protein concentrations had a closer correlation to the blood glucose levels than did the uncorrected levels. The corrected fructosamine levels were not significantly different between healthy volunteers and nondiabetic patients with uremia on conservative treatment. In an in vitro system, fructosamine concentrations were hardly affected by urea, which is known to influence the level of hemoglobin A1. These results suggest that serum fructosamine measurement can provide us with reliable information on a short-term glycemic condition, even in azotemic patients. To be more precise, the serum level of fructosamine corrected for protein concentration can be an excellent glycemic index which is not susceptible to over- or dehydration and is of high clinical value, especially in the management of diabetic patients with chronic renal failure.

Adult↗
PubMed1989

Kinetic behavior and interaction of bacampicillin in alginic acid solution at neural pH region.

Stabilization of bacampicillin (BAPC) in suspension was examined by the addition of alginic acid (Alg). BAPC formed a slightly water-soluble adduct (BAPC-Alg) with Alg, in which BAPC and Alg were presumed to be linked by ionic bonding. However, the suspension of this chemically stable adduct showed a lability to a suspension of BAPC alone; chemically very unstable particles of BAPC base were deposited in the suspension. In contrast, when BAPC-Alg adduct was suspended in 1.0% Alg solution at the same pH region, the precipitation of the particles of BAPC base were not observed. This stabilization is supposed to be due not only to the chemical stability of the adduct, but also to an inhibition of the deposition of an unstable BAPC base particles by Alg.

Alginates↗
PubMed1989

[Prosthetic application of a new measuring instrument of the dynamic periodontal function].

To investigate the principle of Periotest measurement, we compared PT-value and the duration of contact between the rod of the Periotest-Instrument and the tooth measured directly in an oral cavity. Then we applied this apparatus to the subjects with normal periodontium and the patients of prosthetic treatment. The conclusions are as follows: 1. We confirmed that PT-value was calculated from the duration of contact between the rod of the Periotest and the tooth and it showed mainly the dumping effect of the periodontium. 2. There was a close relationship between PT-value and the clinical degree of tooth mobility, especially in the degree of 0 and 1 of tooth mobility. 3. Periotest was very useful not only for the periodontal treatment but also prosthetic application.

Dental Occlusion↗
PubMed1989

[Utility of the impression technique with the individual tray for cast crown].

This study was executed at an opportunity for taking the impressions of a full crown abutment tooth by the five different methods with the four different impression materials; the copper ring tray on the abutment method with the polysulfide rubber, the resin ring tray on the abutment method with silicone rubber, the wash technique with silicone rubber, the hydrocolloid impression technique and the hydrocolloid-alginate impression technique. The reproducibility of the preparation margin on the ten stone dies was photographically measured and the following results were obtained. 1. The reproducibility of the preparation margin was affected considerably by the following conditions. 1) The character of the impression materials, 2) the position of the preparation margin in the gingiva sulcus and 3 the undercut degree beneath the preparation margin. 2. The impression technique with the individual ring tray on the abutment showed great utility under any condition of the preparation margin on the abutment. 3. The impression method should be selected clinically according to the condition of the abutment.

Crowns↗
PubMed1989

[Immunohistology of tumor tissue in local administration of recombinant interleukin-2 in head and neck cancer].

Biopsied specimens from patients treated by local administration of rIL-2 were examined immunohistologically. Lymphocytes infiltrating into the cancer tissue before and after administration of rIL-2 were observed on paraffin embedded sections by Hematoxilin Eosin (HE) stain in relation to the clinical effect. And their subsets were identified on frozen sections by Avidin Biotin peroxidase Complex (ABC) method using monoclonal antibodies to examine what kinds of effector cells were induced and increased in the tumor site by rIL-2 in vivo. The intensity of increasing of tumor infiltrating lymphocytes (TIL) was correlated with the clinical effect of local administration of rIL-2. Tumor Infiltrating Lymphocytes were mainly T lymphocytes, of which Leu-2a+ cells (suppressor/cytotoxic T cells) and Leu-3a + 3b+ cells (helper/inducer T cells) were almost equally observed. Leu-2a+ cells were considered to be mainly cytotoxic T lymphocytes because few Leu-2a+ cells were stained with anti-Leu-15 antibody. After administration of rIL-2, marked infiltration of T lymphocytes was observed and there was no obvious different response in degree of infiltration between Leu-2a+ cells and Leu 3a + 3b+ cells. Furthermore, IL-2 receptor+ T lymphocytes (activated T lymphocytes) were increased after administration of rIL-2. And natural killer (NK) cells were slightly observed and also increased after administration of rIL-2. These findings suggest local administration of rIL-2 has possibility to induce cytotoxic T lymphocytes, to increase NK cells and to activate these lymphocytes in vivo.

Adult↗
PubMed1989

The blood flow in the periodontal ligament regulated by the sympathetic and sensory nerves in the cat.

This study was carried out to investigate the nervous control of the blood flow in the periodontal ligament measured by laser Doppler flowmeter. Ten adult cats were anesthetized with pentobarbital sodium (initial dose of 30 mg/kg, i.v. and maintenance dose of 5 mg/kg, i.v.). After enucleating the left eye ball, the superior alveolar nerve was exposed. The bone overlying the labial aspect of the left maxillary canine tooth root was pared away until a transparent layer of bone was left covering the periodontal ligament. A laser light from a probe of the flowmeter fixed at the tooth was beamed through the thinned bone. Three different patterns of responses were observed following the electrical stimulation of the distal end of the cut superior alveolar nerve: an increasing, a decreasing and a biphasic change of blood flow. The application of capsaicin onto the superior alveolar nerve reduced the response of blood flow increase but had no effect on the response of blood flow decrease. On the other hand, the response of blood flow decrease was completely inhibited by the pretreatment with phentolamine while the response of blood flow increase was not affected. The present results suggest that blood flow in the periodontal ligament of cats is controlled by sympathetic alpha-adrenergic fibers for vasoconstriction and by sensory fibers for vasodilation.

Animals↗
PubMed1989

Protection by thymosin fraction 5 from streptozotocin-induced diabetes in mice.

Protection by thymosin fraction 5 (TF5) from subdiabetogenic-dose streptozotocin (STZ)-induced type I diabetes in CD-1 mice was investigated. Mice which received multiple subdiabetogenic-dose (35 mg/kg) injections of STZ became hyperglycemia within two weeks. Hyperglycemia was also induced in those treated with low dose of TF5 (0.01 mg/day) in addition to STZ, though it was somewhat mild. In contrast, animals given STZ plus high dose of TF5 (0.1 mg/day) remained normoglycemic throughout the whole observation period (within 4 weeks). In the pancreatic islets from these animals, histologically, the well-granulated beta cells were observed and the infiltration of lymphoid cells was absent or mild. These results suggest that the administration of TF5 prevents the induction of insulitis and hyperglycemia in the subdiabetogenic-dose STZ-treated mice.

Animals↗
PubMed1989

[Invasive candidiasis: its predisposing factors, usefulness and limitation of cultural study in its diagnosis, and consideration on the appropriate amphotericin B therapy].

We have reviewed 38 patients with invasive candidiasis and examined its predisposing factors, usefulness and limitation of cultural study in its diagnosis, and effective usage of amphotericin B in its treatment. Invasive candidiasis was diagnosed in 2.4% of the patients admitted during the past 5 years. One of the most important predisposing factors for development of invasive candidiasis was extensive use of antibiotics. Destruction of the mechanical barrier against bacteria and fungi caused by endotracheal intubations and various catheterization was another important factor. Mucosal lesion of the gastrointestinal tract, including stress ulcer, non-specific inflammatory bowel disease and esophageal ulcer, was seen in 30% of the patients. These lesions were thought to be the portal of entry for candida to systemic dissemination. AMPH is the most effective antifungal agent. Total dose of 300 to 1000 mg was effective in the patients. Dosage over 1000 mg was associated with progressive decrease in creatinine clearance. This decrease was irreversible even after discontinuation of AMPH. Candidal overgrowth within the G1 tract was considered to precede invasive candidiasis. Oral AMPH administration was effective in such conditions.

Adult↗
PubMed1988

DNA-binding protein(s) interacts with a conserved nonameric sequence in the upstream regions of wheat histone genes.

A nuclear protein(s), HBP-2, that binds to the upstream region of the wheat histone H4 gene was identified from a fractionated nuclear extract of wheat germ by DNase I footprinting. The DNase I-protected region contained the conserved nonameric motif, CATCCAACG. Cross-competition experiments that used the mobility shift assay showed that this nuclear protein(s) binds specifically to the upstream sequence that has been postulated to be a cis element of the wheat H3 gene. Our findings suggest that this DNA-binding protein(s) may be a trans-acting factor in the regulation of the transcription of wheat histone genes.

Base Sequence↗
PubMed1988

Cupric ion-dependent inhibition of lysosomal acid cholesteryl ester hydrolase in the presence of hydroxylamine.

In the presence of hydroxylamine or ascorbic acid, the inhibitory effects of Cu2+ on lysosomal acid cholesteryl ester hydrolase (acid CEH) partially purified from rat liver were studied. Hydroxylamine stimulated the inhibition of acid CEH activity by Cu2+ but not that by Zn2+, Fe2+, Co2+, Mn2+, Ca2+, Mg2+ and Hg2+. This Cu2+-dependent inhibition of acid cholesterol ester hydrolase (CEH) activity was completely prevented by ethylenediamine tetraacetic acid (EDTA), EGTA and o-phenanthroline, a chelator with a stability constant for Cu2+, and also by sulfhydryl agents and cytoplasmic reducing agents such as cysteine, glutathione and mercaptoethanol. In addition, the stimulative effects of hydroxylamine on Cu2+-dependent inhibition were maintained even after preincubation of Cu2+ with hydroxylamine. On the other hand, ascorbic acid was found to replace the stimulation by hydroxylamine of the Cu2+-dependent inhibition of acid CEH activity but the effects of ascorbic acid progressively became smaller with prolongation of the preincubation time. Moreover, addition of chemical radical scavengers to the reaction mixture did not prevent the Cu2+-dependent inhibition of acid CEH activity in the presence of ascorbic acid. These results suggest that Cu2+ causes inhibition of lysosomal acid CEH activity through the formation of Cu1+ in a reductive medium.

Animals↗
PubMed1988

A novel EBNA-1 titration method and putative anti-EBNA-1 protein.

A novel and rapid EBNA-1 titration method has been developed which uses immunoprecipitation of specific DNA-protein complexes with EBNA-1-positive serum. The method is more sensitive than the conventional immunofluorescence method and has potential value as a diagnostic reagent for clinical laboratories. TPA induction of putative anti-EBNA-1 protein of cellular origin is discussed, which may play a key role for the shift from latent to lytic replication of EBV.

Antibodies, Viral↗
PubMed1988

An architecture of capillary vessels of the palatine tonsils studied by scanning electron microscope--with special references to comparison with the tonsillar cryptscopic images.

The three-dimensional structure of capillary vessels in the human palatine tonsil using corrosion casting techniques was investigated and compared to recently developed cryptscopic images. The postcapillary venules and arterioles were distinguishable from the nuclear impressions on their walls. The configuration of vessels around the micropores of crypts is similar to the images from the cryptscope.

Capillaries↗
PubMed1988

In vivo effect of 1 alpha-hydroxyvitamin D3 on interleukin-2 production in hemodialysis patients.

The immunoregulatory effect of 1 alpha-OHD3, a precursor form of active vitamin D3 1,25 (OH)2D3, was examined in hemodialysis patients. Peripheral blood mononuclear cells (PBM) from hemodialysis patients produced significantly less interleukin-2 (IL-2) than those from normal controls. Four weeks of oral administration of 0.5 micrograms/day of 1 alpha-OHD3 enhanced the IL-2 production of PBM from the patients. This fact suggests that 1 alpha-OHD3 therapy may be useful for the restoration of IL-2 production in hemodialysis patients, and that the vitamin D3 deficiency may be responsible for the impairment of cellular immunity associated with IL-2 production disorder in hemodialysis patients.

Adult↗