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Biomedical subjects

T Nagata

Publications and source records attributed to T Nagata.

At least 217 records · Page 12Linked to original sources
PubMed1998

Personality disorders in patients with eating disorders in Japan.

We assessed the prevalence of personality disorders (PD) using the Structured Clinical Interview for DSM-III-R Personality Disorders (SCID-II) in 36 patients with restricting anorexia nervosa, 30 patients with anorexia nervosa and bulimia nervosa, and 42 patients with bulimia nervosa. Of the 108 patients, 51% met the criteria for at least one PD. The patients with PD had more severe clinical features in terms of bulimic behaviors, concurrent depressive, anxious, and obsessive-compulsive symptoms, and psychopathology related to eating disorders compared to the patients without any PD. The patients with PD, especially borderline PD, also had more severe global functioning and greater numbers of suicidal attempts and hospital admissions. We compare these results with those reported in the Western world and discuss them cross-culturally.

Adolescent↗
PubMed1998

A case of atypical aortic coarctation with refractory congestive heart failure--treatment with axillo-iliac artery bypass.

Coarctation of the aorta is rare. We present a case of atypical coarctation due to aortitis syndrome with congestive heart failure refractory to conventional medical treatment. Although indications for surgical treatment are not well established and, in general, treatment of choice is an aorto-aortic bypass, we selected axillo-iliac bypass with subcutaneous tunnel because of severe heart failure. Postoperatively, the pressure gradient disappeared and heart failure was improved.

Aged↗
PubMed1998

Adhesiveness of AcrySof to a collagen film.

PURPOSE: To measure the adhesiveness of the AcrySof intraocular lens (IOL) to a collagen film to ascertain its capacity to adhere to the lens capsule. SETTING: Haibara General Hospital, Haibara, and Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan. METHODS: Each of five AcrySof IOLs was attached to a collagen film, slightly pressed in intraocular irrigating solution, and then pulled up and off the film with a DuNouy's surface balance. The force recorded by the surface balance at the moment it detached from the film was defined as the lens' adhesiveness. A control experiment was performed using five conventional poly(methyl methacrylate) (PMMA) IOLs. RESULTS: Mean adhesiveness was 2.76 gram-weight (gw) +/- 0.55 (SD) for AcrySof and 0.81 +/- 0.20 gw for PMMA. The difference was statistically significant (P < .0001, t-test). CONCLUSION: AcrySof may have a strong tendency to adhere to the lens capsule, contributing to posterior and anterior capsule clarity and preventing lens decentration in vivo.

Acrylates↗
PubMed1998

Antioxidative activities in some common seaweeds.

Dietary antioxidants from plants are believed to help prevent aging and other diseases through radical scavenging activity. Free radical scavenging activities by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and deoxyribose assay were ascertained among 27 species of common seaweeds using a sequential extraction method. The results indicated that, DPPH scavenging activity existed in 15 species; Gelidium amansii, Gloiosiphonia capillaris, Polysiphonia urceolata, Sargassum kjellmanianum, Desmarestia viridis, and Rhodomela teres showed the strongest activities. On the other hand, the deoxyribose results showed that almost all the seaweed species had good ability to scavenge hydroxyl radicals. The most active species were Rhodomela teres and Chorda filum.

Antioxidants↗
PubMed1998

Are young women in Japan at high risk for eating disorders?: Decreased BMI in young females from 1960 to 1995.

The height, weight and body mass index (BMI) of Japanese males and females aged from 6 to 24 years between 1960 and 1995 were studied. From 1960 to 1995 in males of all ages and in females aged 6-14 years height, weight and BMI increased. In females aged 15-24 years, the height increased and the weight slightly increased, but the BMI gradually decreased from 21.5 in 1960 to 20.5 in 1995. Over the last 35 years adolescent and young adult women have become thinner. Dieting to be slim has become much more prevalent among young women. These findings suggest that young females in Japan have decreased their BMI by dieting in order to become slim. If this tendency persists, with regard to a close relationship between restrained eating or dieting and eating disorders, Japanese young women have a much greater risk of developing eating disorders.

Adolescent↗
PubMed1998

Complement activation as a cause of transient hypotension during plasmapheresis.

Hypotension is one of the most common adverse effect of plasmapheresis (PP) and often is attributed to hypovolemia due to extracorporeal circulation and the vasovagal reflex. Complements are activated during PP, and the activated complements are strong anaphylatoxins and potent vasodilators. Therefore, we studied the relationship between the transient hypotension and the plasma levels of activated complements during and after PP in 8 sessions of 7 patients using the Plasmafro OP-08 as a plasma separator. Five of the patients underwent immunoadsorption PP using the IM-TR 350 or IM-PH 350 as the adsorption column. The other underwent double filtration PP using the Evaflux 4A as a second filter. In 4 of 8 sessions, patients experienced transient hypotension with significantly elevated plasma levels of activated complements C3a and C5a. In contrast, patients without hypotension showed no increases in C3a and C5a values during PP. In this report, we emphasize the critical role of activated complements for hypotension during PP.

Adolescent↗
PubMed1998

Immature thymocyte antigen-1: a novel thymocyte marker discriminating pre- and post-selected thymocytes.

Previously, we described a mAb (1-23) reacting with a novel cell surface antigen expressed on thymocytes at late CD4-CD8- [(double negative (DN)] to early CD4+CD8+ [(double positive (DP)] differentiation stage. Since the expression of this molecule was restricted to immature thymocytes, we designated it as immature thymocyte antigen-1 (IMT-1). In this study, we have investigated the relevance of IMT-1 expression to thymocyte selection using TCR transgenic mice, scid mice or RAG-2-/- mice. The IMT-1+ population in DP thymocytes was decreased in the thymuses of MHC class I-restricted or class II-restricted TCR transgenic mice with a positively selecting MHC background when compared with that of the mice with a non-selecting MHC background. IMT-1+ DP thymocytes were also decreased in TCR transgenic mice in which negative selection occurs. When DP thymocytes in H-Y TCR transgenic mice were stimulated with CD3epsilon mAb in vitro as well as in vivo, the expression of IMT-1 on DP thymocytes was decreased. Furthermore, the expression of IMT-1 on DN thymocytes from RAG-2-/- mice was drastically reduced when CD3epsilon mAb was challenged in vivo. These results suggest that the expression of IMT-1 on DP or DN thymocytes is down-regulated by stimulation through TCR as well as pre-TCR. Taken together, these results show that IMT-1 is a unique surface marker which exquisitely separates pre-selected thymocytes from post-selected thymocytes.

Animals↗
PubMed1998

The identification of DNA binding factors specific for as-1-like sequences in auxin-responsive regions of parA, parB and parC.

We have identified the auxin-responsive region (Aux-RR) of the parA promoter; it is derived from a gene that is induced by auxin in tobacco mesophyll protoplasts. By analyses of gain-of-function and point mutations in transgenic tobacco plants, we showed that an as-1-like sequence was required, but not alone sufficient, for auxin responsiveness of the parA promoter, as has been also shown for the parC promoter in a recent study. A gel mobility shift assay revealed that the as-1-like sequence of the parA promoter bound specifically to the as-1 binding nuclear factor, ASF-1, while the as-1-like sequence of the parC promoter bound specifically to a novel nuclear factor named ALF-1 (as-1-like sequence binding factor-1). Since these bindings were correlated with auxin-induced activation of transcription, those results suggest that ALF-1 is a new nuclear factor involved in auxin responsiveness and that it is distinct from ASF-1. Furthermore, we found that an as-1-like sequence in the AuxRR of parB bound specifically to a tobacco nuclear factor, named ALF-2, which differed from ASF-1 and ALF-1. These results suggest that the auxin responsiveness of the auxin-inducible genes parA, parB and parC are regulated by different mechanisms, even though the cis-acting elements look similar.

Base Sequence↗
PubMed1998

Isolation and characterization of a cytokinin up-regulated gene from tobacco mesophyll protoplasts.

We have isolated a cytokinin up-regulated cDNA clone, H13, from an early stage of cultured tobacco mesophyll protoplasts by a differential display method. The expression of this gene was specifically induced by natural and synthetic cytokinins including N-(2-chloro-4-pyridyl)-N'-phenylurea (4PU30), a diphenylurea-type cytokinin, although the simultaneous presence of auxin was also required. It seems that the preceding treatment of the tobacco mesophyll protoplasts by auxin is necessary for the gene to respond to cytokinin. The addition of a cytokinin antagonist, compound 182, which suppressed the induction of cell division in tobacco mesophyll protoplasts, completely abolished the expression of this gene. Though the predicted gene product of H13 did not suggest us any sequences of defined functions, two domains of the predicted sequence had significant homology to several reported sequences in the data base. The gene product of H13 is proposed to have a role in regenerating cell wall in cultured protoplasts, since a cDNA clone E6, from cotton fiber cells, which has the most closely related structure to H13, has been isolated from cells which showed active cellulose synthesis. This supposition is supported by the evidence that in the absence of cytokinin, cell wall regeneration was significantly suppressed, resulting in failure of the induction of cell division. Thus, the gene product of H13 is supposed to have a role in regenerating cell walls and facilitating the progression of the cell cycle, resulting in the sustained cell division of tobacco mesophyll protoplasts.

Amino Acid Sequence↗
PubMed1998

Single and married patients with eating disorders.

Forty married and 22 unmarried female patients with eating disorders were studied to elucidate the relationship between eating disorders and marriage. Eating disorders developed in 14 patients before marriage (premarital onset) and in 26 patients at or after marriage (postmarital onset). The postmarital onset group was a significantly higher age at onset, but similar in age and duration of illness compared with the group of 22 unmarried patients. However, the various clinical features of the three groups did not differ. Four premarital onset patients showed exaggerated clinical features after marriage, but the other patients showed no change in clinical features after marriage. In the postmarital onset group, eating disorders were triggered in 18 (69%) patients by marital problems, separation or divorce. In contrast, eating disorders were triggered by dieting to be slim in eight (57%) patients of the premarital onset group and 12 (55%) patients of the unmarried group. These results suggest that marital discord plays an important role in the development and maintenance of eating disorders among married women.

Adult↗
PubMed1998

Personality disorders in patients with obsessive-compulsive disorder in Japan.

A total of 75 patients with obsessive-compulsive disorder (OCD) were studied in order to investigate the characteristics of OCD symptoms and the comorbidity of personality disorders (PD). Contamination obsessions and checking compulsions were most commonly found in patients, of whom 53% met the criteria for at least one PD. Among comorbid PD, the anxious-fearful (cluster C) PDs, such as avoidant, obsessive-compulsive and dependent PD, were most prevalent, followed by the odd-eccentric (cluster A) PDs, such as paranoid and schizotypal PD. The patients with PD had more severe social maladaptation and concurrent depressive and anxious symptoms than the patients without any PD, despite the similar severity of OCD symptoms. These results are consistent with those reported in the Western world, and are considered to be relatively stable cross-culturally.

Adolescent↗
PubMed1998

Direct determination of carbon and nitrogen contents of natural bacterial assemblages in marine environments

In order to better estimate bacterial biomass in marine environments, we developed a novel technique for direct measurement of carbon and nitrogen contents of natural bacterial assemblages. Bacterial cells were separated from phytoplankton and detritus with glass fiber and membrane filters (pore size, 0.8 &mgr;m) and then concentrated by tangential flow filtration. The concentrate was used for the determination of amounts of organic carbon and nitrogen by a high-temperature catalytic oxidation method, and after it was stained with 4',6-diamidino-2-phenylindole, cell abundance was determined by epifluorescence microscopy. We found that the average contents of carbon and nitrogen for oceanic bacterial assemblages were 12.4 +/- 6.3 and 2.1 +/- 1.1 fg cell-1 (mean +/- standard deviation; n = 6), respectively. Corresponding values for coastal bacterial assemblages were 30.2 +/- 12.3 fg of C cell-1 and 5.8 +/- 1.5 fg of N cell-1 (n = 5), significantly higher than those for oceanic bacteria (two-tailed Student's t test; P < 0.03). There was no significant difference (P > 0.2) in the bacterial C:N ratio (atom atom-1) between oceanic (6.8 +/- 1.2) and coastal (5.9 +/- 1.1) assemblages. Our estimates support the previous proposition that bacteria contribute substantially to total biomass in marine environments, but they also suggest that the use of a single conversion factor for diverse marine environments can lead to large errors in assessing the role of bacteria in food webs and biogeochemical cycles. The use of a factor, 20 fg of C cell-1, which has been widely adopted in recent studies may result in the overestimation (by as much as 330%) of bacterial biomass in open oceans and in the underestimation (by as much as 40%) of bacterial biomass in coastal environments.

Journal Article↗
PubMed1998

Adhesion of lens capsule to intraocular lenses of polymethylmethacrylate, silicone, and acrylic foldable materials: an experimental study.

AIMS: To investigate the adhesion characteristics of several intraocular lenses (IOLs) to the simulated and rabbit lens capsule. METHODS: Adhesive force to bovine collagen sheets was measured in water with polymethylmethacrylate (PMMA), three piece silicone, and acrylic foldable IOLs. In rabbit eyes, phacoemulsification and IOL implantation were performed. Three weeks later, adhesion between the anterior/posterior capsules and IOL optic was tested, and the capsule was examined histologically. RESULTS: The mean adhesive force to the collagen sheet was 1697 (SD 286) mg for acrylic foldable, 583 (49) mg for PMMA, and 0 mg for silicone IOLs (p = 0.0003, Kruskal-Wallis test). Scores (0-5) of adhesion between rabbit anterior capsule and IOL optic were 4.50 (0.55) for acrylic foldable, 3.20 (0.84) for PMMA, and 0.40 (0.55) for silicone IOLs (p = 0.004). Scores between rabbit posterior capsule and IOL optic displayed a similar tendency; 4.50 (0.84) for acrylic foldable, 3.00 (1.00) for PMMA, and 0.40 (0.55) for silicone IOLs (p = 0.021). Histological observation indicated that the edge of IOL optic suppressed the migration of lens epithelial cells towards the centre of the posterior capsule. This inhibitory effect was most pronounced with acrylic foldable IOL and least with silicone IOL. CONCLUSIONS: The acrylic foldable IOL adhered to the lens capsule more than the PMMA IOL, and the silicone IOL showed no adhesiveness. These differences seem to play a role in preventing lens epithelial cells from migrating and forming posterior capsule opacification.

Acrylic Resins↗
PubMed1998

Characterization of mouse retinoid X receptor (RXR)-beta gene promoter: negative regulation by tumor necrosis factor (TNF)-alpha.

A genomic clone of mouse retinoid X receptor (RXR)-beta (Rxrb) has recently been isolated and mapped within the H2-K region of the mouse major histocompatibility complex. A putative 250-bp promoter, which is located between Rxrb and H2-Ke4, and may possibly be their common promoter, has also been identified. In order to study the gene regulation of Rxrb, we analyzed the transcriptional function of the Rxrb promoter with chimeric constructs containing the Rxrb promoter fragments fused upstream of a firefly luciferase cDNA, which were transiently transfected into rat GH3 cells. We found that 1) a part of the H2-Ke4 genomic region (1.9-kb), as well as the 250-bp promoter, was transcriptionally active as an Rxrb promoter; 2) tumor necrosis factor (TNF)-alpha significantly repressed the activity of the 250-bp promoter although thyroid hormone, 9-cis retinoic acid, interleukin (IL)-1beta, and IL-6 did not affect the activity; 3) either the change in orientation or point mutations of a consensus NF-kappaB site located in the 250-bp promoter did not affect the repression; 4) SB 203580, a highly specific inhibitor of p38 mitogen-activated protein (MAP) kinase, completely abolished the repression by TNF-alpha. These data suggest that TNF-alpha represses the promoter activity of the 250-bp region, and the repression is mediated by p38 MAP kinase independent of NF-kappaB. We thus have first shown a relation between the retinoic acid receptor and a cytokine TNF-alpha.

Alitretinoin↗
PubMed1998

Techniques of radioautography for medical and biological research.

Standard techniques for radioautography used in biological and medical research can be classified into three categories, i.e., macroscopic radioautography, light microscopic radioautography and electron microscopic radioautography. The routine techniques used in these three procedures are described. With regard to macroscopic radioautography, whole body radioautography is a standard technique which employs freezing and cryosectioning and can demonstrate organ distributions of both soluble and insoluble compounds. In contrast, in light and electron microscopic radioautography, soluble and insoluble techniques are separated. In order to demonstrate insoluble labeled compounds, conventional chemical fixations such as formalin for light microscopy or buffered glutaraldehyde and osmium tetroxide for both light and electron microscopy followed by dehydration, embedding and wet-mounting applications of radioautographic emulsions can be used. For the demonstration of soluble labeled compounds, however, cryotechniques such as cryofixation, cryosectioning, freeze-drying, freeze-substitution followed by dry-sectioning and dry-mounting radioautography should be employed both for light and electron microscopy. The outlines of these techniques, which should be utilized in various fields of biological and medical research, are described in detail.

Autoradiography↗
PubMed1998

Radioautographology: the proposal of a new concept.

A new concept termed "radioautographology" is advocated. This term was synthesized from "radioautography" and "ology", expressing a new science derived from radioautography. The concept of radioautographology (RAGology) is that of a science whose objective is to localize radioactive substances in the biological structure of objects and to analyze and study the significance of these substances in the biological structure. On the other hand, the old term radioautography (RAG) is the technique used to demonstrate the pattern of localization of various radiolabeled compounds in specimens. The specimens used in biology and medicine are cells and tissues. They are fixed, sectioned and placed in contact with the radioautographic emulsions, which are exposed and developed to produce metallic silver grains. Such specimens are designated as radioautographs and the patterns of pictures made of silver grains are named radioautograms. The technicians who produce radioautographs are named radioautographers, while those who study RAGology are scientists and should be called radioautographologists. The science of RAGology can be divided into two parts, general RAGology and special RAGology, as most natural sciences usually can. General RAGology is the technology of RAG which consists of three fields of science, i.e., physics concerning radioactivity, histochemistry for the treatment of cells and tissues, and photochemistry dealing with the photographic emulsions. Special RAGology, on the other hand, consists of applications of general RAGology. The applications can be classified into several scientific fields, i.e., cellular and molecular biology, anatomy, histology, embryology, pathology and pharmacology. Studies carried out in our laboratory are summarized and reviewed. All the results obtained from such applications should be systematized as a new field of science in the future.

Autoradiography↗