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Biomedical subjects

T Takata

Publications and source records attributed to T Takata.

At least 109 records · Page 6Linked to original sources
PubMed1997

A study on the relationship between blood lead levels and anemia indicators in workers exposed to low levels of lead.

The workers were classified into two groups according to their median value of blood and urine lead levels and urine ALA levels. The group of workers whose blood lead levels were in a lower range (1-15 micrograms/dl) exhibited significantly lower hematocrit, hemoglobin and erythrocytes than the group of the workers whose blood lead levels were in a higher range (16-39 micrograms/dl) (P < 0.001). However, there were no significant differences in the mean values of hematocrit, hemoglobin and erythrocyte counts between the workers whose urine lead or ALA levels were below the median value and those whose urine lead or ALA levels were above the median value. Because the bulk of blood lead is reported to exist in the soluble fraction of erythrocytes, low levels of blood lead are believed to exhibit low levels of anemia indicators.

Adult↗
PubMed1997

[alpha-Galactosidase gene mutation and its expression product in Fabry disease (alpha-galactosidase deficiency)].

Fabry disease is characterized by a deficiency of lysosomal alpha-galactosidase (alpha-Gal) and the accumulation of glycosphingolipid (e.g. predominantly globotriaosylceramide) in various tissues, mainly in lysosomes of the vascular endothelium. This disorder is currently classified into two clinical phenotypes; classical severe type and atypical variant type. Classical form patients, with clinical manifestations of generalized angiopathy of early onset, usually show no detectable alpha-Gal activity. Recently, there are also atypical form patients with residual alpha-Gal activity and late-onset cardiomyopathy without other systemic manifestations. So far, we identified a number of alpha-Gal gene mutations including partial gene deletions, splicing mutations, nonsense mutations and missense mutations. They were heterogeneous and more than half of them were missense mutations. To clarify the molecular mechanism causing the enzyme defect in the patient, various missense mutations were expressed in COS-1 cells. At least, two groups have been identified; one expressing a mutant enzyme without catalytic activity (non-functional type), and the other expressing catalytically active but unstable mutant enzyme (fragile type). The fragile type mutants were widely present in the different clinical phenotypes from classical severe type to atypical milder type including subclinical Fabry hemizygote, and the mutant enzymes were posttranslationally inactivated and degraded in the cells. The inactivation and degradation were prevented by the addition of substrate analogue; galactose or melibiose. These findings provided us with significant informations on the molecular pathology of the enzyme defect in Fabry disease, and suggested the possibility of a new therapeutic approach for this disease.

Fabry Disease↗
PubMed1996

Immunohistochemical demonstration of prostaglandins in various tissues of the rat.

To demonstrate the tissue localization of prostaglandin (PG) E2, PGF2 alpha and 6-keto-PGF1 alpha (a stable metabolite of PGI2) various tissues, including decalcified periodontal tissue of 7-week-old male Wistar strain rats, were immunohistochemically examined using a streptavidin-biotin complex method. Besides tissue macrophages and endothelial cells in various tissues, hepatocytes, renal tubular cells, and parietal and chief cells in the gastric mucosa showed a positive reaction for the various PGs examined. PGs were demonstrated in the cytoplasm or in association with the cell membrane. We generally observed no difference between the localization patterns of PGE2-, PGF2 alpha-, and 6-keto-PGF1 alpha-positive cells in these tissues. However, in the periodontal ligament and alveolar bone, 6-keto-PGF1 alpha was localized in the cytoplasm of osteocytes, osteoblasts, cementocytes, and cementoblasts, while no reaction for PGE2 or PGF2 alpha was revealed in these cells. We demonstrated the immunohistochemical localization of PGs in various rat tissues including decalcified periodontal tissue and discuss the important roles of PGs in the modulation of their normal functions in these tissues.

Animals↗
PubMed1996

Immunohistochemical demonstration of prostaglandins E2, F2 alpha, and 6-keto-prostaglandin F1 alpha in rat dental pulp with experimentally induced inflammation.

Using formalin-fixed and EDTA-decalcified cryostat sections, the immunohistochemical localization of prostaglandin (PG) E2, PGF2 alpha, and 6-keto-PGF1 alpha (a stable metabolite of PGI2) was examined in normal rat and inflamed dental pulp. Inflammation was induced by opening the pulp chamber. There was no immunoreactivity for prostaglandins in normal dental pulp, whereas positivities for PGE2, PGF2 alpha, and 6-keto-PGF1 alpha were demonstrated in the cytoplasm of macrophages and endothelial cells in the inflamed dental pulp. In addition to these cells, numerous pulp cells and odontoblasts existing in the inflamed pulp and its apical noninflamed area also were intensely stained for PGF2 alpha. Such an area with positive cells gradually extended in an apical direction with the progression of inflammation. These findings suggested that PG production from these host cells is involved in development of inflammation of rat dental pulp.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Immunohistochemical detection of prostaglandins E2, F2 alpha, and 6-keto-prostaglandin F1 alpha in experimentally induced periapical inflammatory lesions in rats.

The immunohistochemical localization of prostaglandin (PG) E2, PGF2 alpha, and 6-keto-PGF1 alpha (a stable metabolite of PGI2) was demonstrated in rat periapical inflammatory lesions induced by opening the pulp chamber. Two wk postoperatively, suppurative periapical lesions were formed, and active bone resorption was seen surrounding these lesions. Immunohistochemical examination showed that macrophages infiltrating in inflammatory tissue were positively stained for the examined PGs. In some lesions, wherein acute inflammatory changes subsided and proliferation of fibroblasts started, the fibroblasts were positively stained for 6-keto-PGF1 alpha. Osteocytes and osteoblasts were also positive for 6-keto-PGF1 alpha not only in experimental animals, but also in untreated animals. However the staining intensity of the PG in these cells was higher in periapical lesions than in normal condition. These findings suggested that the cellular sources of the PGs in the periapical lesions are mainly macrophages and fibroblasts, and that the PGs produced by these cells, and possibly osteoblast and osteocytes, may contribute to the osteolytic resorption of periapical lesions.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Immunohistochemical observations on a possible ameloblastic fibro-odontoma.

An ameloblastic fibro-odontoma which occurred in the mandible of a 3-year-old Japanese boy is reported together with immunohistochemical findings. Histologically, the tumor consisted of an ameloblastic fibroma-like area and some typical complex odontoma-like areas. The epithelial islands in the ameloblastic fibroma-like area showed different developmental stages of the epithelial-connective tissue interface. Immunohistochemical examination revealed that all epithelial components in the ameloblastic fibroma-like area showed expression of CK 8, CKs 13, 16, CK 14, CK 18 and CK 19, and coexpression of these cytokeratins and vimentin. These findings suggest that even the epithelial component without obvious epithelial-mesenchymal induction showed the final cell differentiation of the enamel organ with the potential for epithelial-mesenchymal induction.

Cell Differentiation↗
PubMed1995

Effects of deprivation of oxygen or glucose on the neural activity in the guinea pig hippocampal slice--intracellular recording study of pyramidal neurons.

The block of synaptic transmission and neural activity during deprivation of oxygen or glucose has been simply attributed to the lack of energy due to the disorder of energy production. To clarify the interrelation between neural activity and energy metabolism during hypoxia or glucose deprivation, we studied the changes in ATP levels and electrical events of pyramidal neurons in the CA3 region and [Ca2+]i mobilization of the dendritic and cellular region of CA3 area, using guinea pig hippocampal slices. The studies of field potentials and intracellular recording from the pyramidal cell of CA3 area during hypoxia or glucose deprivation revealed that the cessation of synaptic activity and the depolarization of resting potential occurred earlier than during glucose deprivation while the increase of [Ca2+]i was slow during hypoxia but rapid during glucose deprivation although the ATP level of CA3 area was maintained at its original level for 20 min during both conditions. When glucose was replaced by lactate, ATP concentration was not reduced but the electrical activity decayed and [Ca2+]i increased with the similar time course as observed during lack of glucose, only. These results suggest that different mechanisms underlie the block of synaptic transmission in the CA3 pyramidal neurons during hypoxia and glucose deprivation and that lactate cannot substitute for glucose in the maintenance of neural activity.

Adenosine Triphosphate↗
PubMed1995

The release of glutamate and accumulation of intracellular calcium in the guinea pig hippocampal slices during glucose deprivation.

Simultaneous recordings of the time course of change in the extracellular glutamate concentration ([Glu]O) and intracellular Ca2+ level [Ca2+]i during glucose deprivation were performed in the CA3 area of hippocampal slices from guinea pig. Direct measurement of [Glu]O with a glutamate sensitive sensor revealed that [Glu]0 showed a biphasic increase during glucose deprivation and decreased rapidly after re-introduction of glucose in the perfusing medium. The initial increase of [Glu]O preceded [Ca2+]i increase and thereafter a sustained increase of [Glu]O was observed concomitant with massive [Ca2+]i accumulation. Replacement of Na with Li markedly attenuated the rapid reduction of [Glu]O, suggesting that the reduction of [Glu]O was due to Na-dependent glutamate uptake system, which worked immediately after energy recovery.

Animals↗
PubMed1995

Purification and characterization of ferritin from Campylobacter jejuni.

We purified an iron-containing protein from Campylobacter jejuni using ultracentrifugation and ion-exchange chromatography. Electron microscopy of this protein revealed circular particles with a diameter of 11.5 nm and a central core with a diameter of 5.5 nm. The protein was composed of a single peptide of 21 kDa and did not serologically cross-react with horse spleen ferritin. The UV-visible spectrum of the protein showed no absorption peaks in the visible region, indicating that little or no heme is bound. The ratio of Fe:phosphate of C. jejuni ferritin was 1.5:1. From these morphological and chemical examinations, we concluded that the C. jejuni purified protein is a ferritin of the same class as that of Helicobacter pylori and Bacteroides fragilis and differs from the heme-containing bacterioferritin of Escherichia coli. The 30 N-terminal amino acids were sequenced and were found to resemble the sequences of other ferritins strongly (H. pylori ferritin, 73% identity; B. fragilis ferritin, 50% identity; E. coli gene-165 product, 50% identity), and to a lesser degree, bacterioferritins (E. coli bacterioferritin, 26% identity; Azotobacter vinelandii, 26% identity; horse spleen ferritin 30% identity). Proteins that cross-reacted with antiserum against the ferritin of C. jejuni were found in other Campylobacter species and in H. pylori, but not in Vibrio, E. coli, or Pseudomonas aeruginosa.

Amino Acid Sequence↗
PubMed1995

The role of cardiac output response in blood flow distribution during exercise in patients with chronic heart failure.

The relationship between blood flow in the working leg and cardiac output (Q) response was determined for patients with chronic heart failure. The ratio of leg blood flow (LBF) to Q (LBF/Q) at the same workload during submaximal exercise was significantly different in three groups of patients classified by peak cardiac index: it was 0.22 +/- 0.08 in the 'satisfactory' Q group vs 0.33 +/- 0.09 in the moderate Q group, and 0.38 +/- 0.08 in the poor Q group (P < 0.01) in the first stage of exercise. delta LBF/delta Q, the slope of change in leg blood flow to Q from rest to peak exercise, was significantly larger in the poor Q group than in the satisfactory Q group (P < 0.01). The intergroup arteriovenous oxygen difference (AVO2D) in organs other than the leg was large, while that in the working leg was small. Leg vascular resistance at submaximal workload was similar in the three groups, but vascular resistance in other organs was significantly higher in the poor Q group than in the satisfactory Q group (P < 0.001). These findings suggested that metabolic vasodilating stimuli in the working leg attenuated excessive vasoconstriction and caused a shift in blood flow from other organs to the working leg under conditions of severely reduced Q response.

Adult↗
PubMed1995

The purification of a GroEL-like stress protein from aerobically adapted Campylobacter jejuni.

From plate cultures of Campylobacter jejuni grown in room air a particulate protein of 62 kDa was isolated by ion-exchange chromatography. The protein had a square shape from the side view but when viewed from the top it had a star-shaped structure. The molecular size of the whole particle determined by gel filtration was 850 kDa which suggested the presence of 14 subunits of 62 kDa in each particle. The N-terminal 37 amino residues showed more than 80% homology with the sequence of these heat shock protein (HSP) 60 homologs of Chlamydia trachomatis, Helicobacter pylori, and Escherichia coli (GroEL). This protein is immunologically cross-reactive with the antiserum for the 60-kDa HSP of Yersinia enterocolitica. Production of the 62-kDa protein increased under heat stress and growth in an aerobic atmospheric environment. From these observations we concluded that the 62-kDa protein is a Campylobacter stress protein (Cj62) which belongs to the HSP 60 family.

Adaptation, Physiological↗
PubMed1995

Correlation between argyrophilic nucleolar organizer region (AgNOR) counts and histologic grades with respect to biologic behavior of salivary adenoid cystic carcinoma.

The quantification of argyrophilic nucleolar organizer regions (AgNOR) was performed in 34 cases of adenoid cystic carcinoma (ACC) to determine (1) whether AgNOR count correlates with its different histologic grades pertinent to prognosis, and (2) whether AgNOR counts can offer any additional prognostic advantage over histologic grading. According to Szanto et al.'s histologic grading criteria (4), 12 cases were Grade 1, 7 cases Grade 2, and 15 were Grade 3. Patients were divided into 20 favorable cases (without metastases) and 14 unfavorable cases (with metastases). Although most Grade 3 tumors had high AgNOR counts (> or = 4) and Grade 1 tumors with low (< 4) AgNOR counts outnumbered those with high AgNOR counts, considerable overlap of AgNOR values in different grades was observed. However, all unfavorable cases had high AgNOR counts regardless of their histologic grades, suggesting that the metabolic alterations associated with the malignancy level of ACC may partly be portrayed by the AgNOR count, irrespective of the histologic appearance. Cumulative survival rates of Grade 1 tumors and of tumors with low AgNOR counts were better than those of Grade 3 tumors and those with high AgNOR counts. Within the limited number of cases in this series the AgNOR count exhibits a potential for identifying some aggressive ACCs that cannot be detected by histology alone.

Adult↗
PubMed1995

Florid cemento-osseous dysplasia with concomitant simple bone cysts: a case in a Japanese woman.

Florid cemento-osseous dysplasia (FCOD) with concomitant simple bone cysts is not common. We report a case of FCOD involving three quadrants of the jaws and associated with two large cystic lesions of the mandible in a 40-year-old Japanese woman. Microscopic examination revealed unencapsulated fibroblastic proliferation with formation of bone and cementum, showing different developmental stages, and cystic lesions resembling a simple bone cyst.

Adult↗
PubMed1995

[Oil mist exposure in industrial health--a review].

Many reports dealing with the toxicity of oil mist in industrial health have been published. The condition appears to be worldwide in distribution and the number of reported cases increases with increasing clinical awareness. In 158 reports published from 1965 to 1993 the following diseases were observed: Skin--contact dermatitis, oil acne and photosensitive allergic dermatitis; Scrotum--benign and malignant tumors; Respiratory system-nasal discomfort symptoms, rhinitis, nasal mucosal dysplasia, nasal mucosal tumor, laryngeal cancer, bronchitis, lipoid pneumonia, lung fibrosis, lung cancer and bronchial asthma; Others--possible carcinogenicity, high incidence of chromosomal change. This shows that oil mist appears to be involved in many industrial diseases, however, cause-and-effect relationship still remains a matter of conjecture; in which exposure dose and/or duration-dependent toxicity is highly probable. Further investigations will be required including immunotoxicological as well as environmental studies for oil mist exposure.

Dermatitis, Contact↗
PubMed1995

Periodontal tissue regeneration on the surface of synthetic hydroxyapatite implanted into root surface.

Several studies have demonstrated that periodontal ligament (PDL)-derived cells can form a new connective tissue attachment (NCTA) not only on denuded dentin but also on nondental inorganic materials. Although the cellular response to these materials may be different than that to denuded dentin, the process of NCTA formation on the surface of non-dental inorganic materials is still undetermined. In the present study, we compared the process of NCTA formation on the surface of an inorganic material with that on a denuded root surface by implanting a block of synthetic hydroxyapatite (HA) into a root cavity prepared on the first molar of a rat. We then observed tissue regeneration under conditions where the PDL-derived cells could populate the HA surface using an occlusive membrane. After fibrinous exudation at 3 days postoperatively, granulation tissue from the PDL filled the space between the HA block and the membrane at 1 week. Four weeks after the operation, although the granulation tissue increased in density at the interface to the HA block, no obvious deposition of cementum-like tissue was seen on the HA block. Six weeks after the operation, the deposition of cementum was observed on the surface of the HA block. The deposition of cementum became more extensive and insertion of collagen fibers into the cementum layer became more obvious 8 weeks postoperatively. Twelve weeks after the operation, the cementum covered almost the entire surface of the HA block. On the surface of the denuded dentin in control teeth, cementum deposition was seen at 4 weeks after the operation and increased in thickness from 6 weeks on.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Immunohistochemical study of gamma delta T cells in human gingival tissues.

The distribution and the density of gamma delta T cells in human gingival tissues were examined immunohistochemically in biopsy samples obtained from 20 subjects. Few gamma delta T cells were observed in gingival tissue free from inflammatory cell infiltration, but were found, albeit in low numbers, in association with inflammatory cell infiltration, especially T cells. This relationship with T cells was confirmed statistically. The ratios of gamma delta T cells to T cells in the epithelia and in the connective tissue were calculated in the sections in which more than 500 CD3-positive cells were identified. Seven of eight such epithelial specimens showed a ratio of less than 1% and one less than 2% (mean +/- SD; 0.8% +/- 0.4). In the connective tissue, 8 of 13 such specimens showed less than 1%, three less than 2%, one 3%, and one 7% (1.4% +/- 1.9). These results suggest that basically gamma delta T cells are not resident cells in the gingival epithelium such as comprise the first defense line against exogenous irritation. They may play some role in the pathogenesis of periodontal disease collaborating with alpha beta T cells in the inflammatory response.

Adult↗
PubMed1995

[The structure of self in Japanese culture: aspects and age differences].

A questionnaire was administered to college students and adult members of society to tap the structure and content of self that are characteristic of Japanese culture. The items measured some of the constructs that presumably characterize self in Japanese culture: namely, "amae" (Doi, 1971), "Japanese ego" (Minami, 1983), and "Kanjinshugi" (Hamaguchi, 1982). Factor analysis found eight factors, which were classified into two aspects: social and individualistic. These two aspects both included universal and culture-specific factors, and the universal factors appeared to correspond fairly well to Markus and Kitayama's (1991) "interdependent and independent construals of the self". College students see more importance in the social aspects of the self than adults in both universal and culture-specific factors. On the individualistic side, however, they rated themselves as being less independent in the universal factors, but more exclusively egocentric in the other factors. The findings were discussed in terms of the development of self of young adults in Japan.

Adult↗