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Biomedical subjects

T Kitamura

Publications and source records attributed to T Kitamura.

At least 271 records · Page 15Linked to original sources
PubMed1998

Identification of the chemokine receptor TER1/CCR8 expressed in brain-derived cells and T cells as a new coreceptor for HIV-1 infection.

We have isolated HIV-1 variants that infect brain-derived CD4-positive cells, which are resistant to both macrophage (M)-tropic and T-cell line (T)-tropic HIV-1 strains. It is possible that this brain cell tropism of the HIV-1 variants is determined by the interaction of HIV-1 with a chemokine receptor (CKR) gene. We attempted to detect the expression of the CKR-like genes using degenerate PCR primers. The brain-derived cells expressed a CKR-like gene TER1/CCR8. Human CD4-expressing cells resistant to all HIV-1 strains became susceptible to brain-cell tropic HIV-1 variants after expression of TER1 in these cells, but these cells were still resistant to M-tropic strains or T-tropic IIIB strain. TER1 was expressed in brain-derived cells and human T-cells. These findings suggest that TER1/CCR8 functions as a co-receptor for HIV-1 infection for brain-derived cells as well as T cells.

Brain↗
PubMed1998

Preparation of Silica Aerogel from TEOS

Silica alcogels were synthesized by the sol-gel polymerization of tetraethylorthosilicate (TEOS). In the synthesis, HCl and NH3 were used as hydrolysis and condensation catalysts. The gelation time became short and the visible light transmittance increased with increasing the amount of HCl or lengthening the hydrolysis time. The alcogels were dried under supercritical conditions with carbon dioxide, and silica aerogels were obtained. As a result of characterization by visible light transmission and N2 adsorption, the aerogels are mesoporous materials with high surface areas. The experimental results suggest that the aerogel properties are not influenced by the drying conditions such as extraction temperature, extraction time, depressurizing temperature, and depressurizing rate. On the other hand, the properties are changed under the conditions of sol-gel polymerization. In the preparation of highly transparent aerogels with high surface areas and large pore volumes, it is necessary to synthesize highly transparent alcogels. It is found that the visible light transmittance of alcogels is an index for preparing aerogels from TEOS. Copyright 1998 Academic Press. Copyright 1998Academic Press

Journal Article↗
PubMed1998

The long term efficacy of combined transcatheter arterial embolization and percutaneous ethanol injection in the treatment of patients with large hepatocellular carcinoma and cirrhosis.

BACKGROUND: The long term efficacy of combination therapy with transcatheter arterial embolization (TAE) followed by percutaneous ethanol injection (PEI) was studied in patients with large primary hepatocellular carcinoma (HCC) tumors and cirrhosis. METHODS: The series included 83 patients with large unresectable HCC lesions, the largest of which was greater than 3 cm in largest dimension. Fifty-five had a solitary lesion and 28 had multiple (2 or 3) lesions. All patients were treated with both TAE and PEI and their survival rates were determined. RESULTS: The 3-, 5-, and 7-year calculated survival rates for the patients were be 68%, 35%, and 14%, respectively. The number of lesions (solitary vs. multiple), the stage of cirrhosis (Child's Class A vs. Class B or C), and the size of the largest lesion (3-5 cm in largest dimension compared with > 5 cm) significantly affected the survival rate (P < 0.05 to P < 0.01, log rank test). The 3-, 5-, and 7-year survival rates of the Child's Class A patients who had a 3-5 cm solitary lesion (n = 22) were 100%, 75%, and 27%, respectively. The Cox proportional hazards model showed the stage of cirrhosis and size of the largest lesion to be independently associated with survival. No serious complications occurred during or after treatment. CONCLUSIONS: Combination therapy with TAE and PEI is an effective and safe treatment that may improve the long term survival of patients with cirrhosis associated with large HCC lesions, and survival after this combination therapy may be comparable to that after surgery.

Adult↗
PubMed1998

RANTES-induced T cell activation correlates with CD3 expression.

The chemokine RANTES induces a unique biphasic cytoplasmic Ca2+ signal in T cells. The first phase of this signal, similar to that of other chemokines, is G-protein mediated and chemotaxis associated. The second phase of this signal, unique to RANTES and evident at concentrations greater than 100 nM, is tyrosine kinase linked and results in a spectrum of responses similar to those seen with antigenic stimulation of T cells. We show here that certain jurkat T cells responded to RANTES solely through this latter pathway. A direct correlation between the RANTES-induced second phase response and CD3 expression was demonstrated in these cells. Sorting the Jurkat cells into CD3(high) and CD3(low) populations revealed that only the CD3(high) cells were responsive to RANTES. Furthermore, stimulation of these Jurkat cells with anti-CD3 mAb significantly depresses their subsequent response to RANTES. While a RANTES-specific chemokine receptor is expressed at a low level on these Jurkat cells, the RANTES-induced activation is dependent on the presence of the TCR. Thus, stimulation through TCR may partially account for RANTES' unique pattern of signaling in T cells.

Benzoquinones↗
PubMed1998

Different personalities between depression and anxiety.

We examined the different personality dimensions between depression and anxiety with Cloninger's seven-factor model of temperament and character. The Temperament and Character Inventory (TCI), which measures four temperament and three character dimensions of Cloninger's personality theory (125-item short version), the Self-rating Depression Scale (SDS), and the State-Trait Anxiety Inventory (STAI) were administered to 223 Japanese students. With hierarchical regression analysis, the SDS score was predicted by scores of Harm-Avoidance, Self-Directedness, and Self-Transcendence, even after controlling for the STAI score. The STAI score was predicted by scores of Self-Directedness and Cooperativeness, even after controlling for the SDS score. More importance should be attached to these dimensions of character because they might contribute to both depression and anxiety.

Adolescent↗
PubMed1998

Dimensions of schizophrenic positive symptoms: an exploratory factor analysis investigation.

Current psychopathology classifies schizophrenic positive symptoms into four groups: delusions, hallucinations, formal thought disorder, and catatonic symptoms. The present study explores the factor structure of different positive symptoms to refine this classification. The 35 positive symptoms of 429 psychiatric patients, consecutively admitted to any of 95 mental hospitals, with diagnosis of the ICD-10 F20 schizophrenia, were studied. After excluding those items with a base rate of 10% or less, factor analysis yielded six factors. The first factor was loaded by most of Schneider's first-rank symptoms and two specific auditory hallucinations; the second by all the catatonic symptoms and incoherence; the third by bodily delusions/hallucinations; the fourth by delusions of persecution and reference; the fifth by grandiose and religious delusions; and the sixth by visual and miscellaneous hallucinations. The finding that schizophrenic positive symptoms may have more than four dimensions suggests the need for reclassification of schizophrenic symptoms and for reconsideration of evidence-based diagnostic criteria for the disorder.

Adolescent↗
PubMed1998

Effects of teprenone on gastric epithelial restoration in a rabbit cultured cell model.

The mechanism of action of gastrocytoprotective agents is not fully understood. We assessed the effects of an anti-ulcer agent, teprenone, and bile acid on epithelial restoration. Teprenone with or without deoxycholic acid was added to a complete confluent cultured gastric epithelial cell sheet after wounding. Restoration was monitored for 48 h, and the wound size was assessed. Migration velocity was measured, and proliferation was detected by sequential staining with bromodeoxyuridine. The labeling index was calculated. Restoration was completed within 48h in controls, whereas deoxycholic acid retarded repair. The migration velocity was suppressed by deoxycholic acid treatment. The number of proliferative cells peaked at 36 h (labeling index, 1.7%) in controls. In the deoxycholic acid group, the maximal labeling index was 0.5% at 48 h. Teprenone abolished the bile acid-induced retardation. Teprenone showed cytoprotective effects against deoxycholic acid-induced inhibition of epithelial cell migration and proliferation.

Animals↗
PubMed1998

Use of balloon-occluded retrograde transvenous obliteration with ethanolamine oleate for the treatment of hepatic encephalopathy in a cirrhotic patient with a large spontaneous splenorenal shunt.

We describe a technique for the treatment of hepatic encephalopathy in a cirrhotic patient with a large spontaneous splenorenal shunt. This large shunt was successfully occluded without severe complications by retrograde transrenal venous obliteration with ethanolamine oleate after balloon occlusion. This procedure may be an effective method to occlude a large spontaneous splenorenal shunt for the treatment of hepatic encephalopathy.

Aged↗
PubMed1998

Differential Ca2+ signaling in neonatal and adult rat hepatocyte doublets.

BACKGROUND/AIMS: Intracellular Ca2+ ([Ca2+]i) is important in various cellular functions, including cellular proliferation and differentiation. To elucidate the relationship between [Ca2+]i oscillations and physiological hepatocyte proliferation, phenylephrine-evoked [Ca2+]i responses were sequentially investigated using short-term cultured hepatocyte doublets obtained from 1-, 3-, 6- and 8-week-old rats. METHODS/RESULTS: DNA synthesis in hepatocytes, determined by BrdU incorporation, was approximately 20% in 1-week-old rats, and decreased to <1% as the rats aged. Correspondingly, [Ca2+]i responses evoked by 10 micromol/l phenylephrine in hepatocyte doublets shifted from transient to sinusoidal-type [Ca2+]i oscillations and then to a sustained increase in [Ca2+]i, followed by a gradual return to baseline. The incidence of [Ca2+]i oscillations was 100+/-0.0%, 83.3+/-16.7%, 38.7+/-0.6% and 5.5+/-5.0% in 1-, 3-, 6- and 8-week-old rats, respectively. Removal of extracellular Ca2+ did not abolish [Ca2+]i oscillations, indicating that [Ca2+]i oscillations were caused primarily by Ca2+ mobilization from internal sites of the cells. The [Ca2+]i level in each of the adjacent cells was synchronous in sustained increase in [Ca2+]i, but asynchronous in [Ca2+]i oscillations. In proliferating doublets obtained from 1-week-old rats, the frequency of oscillations increased in a dose-dependent manner for phenylephrine concentrations of 1 to 100 micromol/l. CONCLUSIONS: Phenylephrine-evoked [Ca2+]i oscillations were directly related to hepatocyte proliferation and were mediated by frequency modulation. These results suggest that phenylephrine-evoked [Ca2+]i oscillations may contribute to cell-cycle progression of hepatocytes in physiological liver growth.

Animals↗
PubMed1998

Immunohistochemical study of p21WAF1 and p53 proteins in prostatic cancer and their prognostic significance.

Mutations of p53 tumor suppressor gene occur in a subset of aggressive prostatic carcinomas and are detectable by immunohistochemistry. However, it is uncertain whether p53 overexpression really reflects p53 gene mutation or loss of p53 function. p21WAF1, an inhibitor of cyclin-dependent kinases, is activated by wild-type p53 protein, not by mutant type. Therefore, it is possible that combined analysis of p21WAF1 and p53 proteins aids in determining the functional status of p53 immunostaining. Routinely processed prostatic tissues from 60 patients with prostatic adenocarcinomas were examined by immunohistochemistry for p21WAF1 and p53 expression. As for tissue distribution, p21WAF1 protein was expressed mostly in the luminal layers, in contrast, p53 protein was restricted to the basal layers of benign prostatic glands. In prostatic adenocarcinomas, p21WAF1 protein was more likely to be expressed in well-differentiated areas; in contrast, p53 protein was more likely in poorly differentiated areas in the tumors. The percentage of positive nuclear areas for p21WAF1 and p53 proteins in prostatic adenocarcinomas, assessed by CAS200 computerized image analyzer, were 8.6+/-10% and 16+/-14% (mean+/-SE), respectively. The survival study showed that the p53+/ p21- phenotype showed poorer prognosis than p53+/p21+. Multivariate analysis showed that p21WAF1 expression, clinical stage, and Gleason score were independent prognosticators. In conclusion, p21WAF1 immunohistochemistry is a useful method for interpretation of p53 immunohistochemical results. Combined analysis by p21WAF1 and p53 immunostaining would predict the patient survival more accurately than p53 immunostaining alone.

Adenocarcinoma↗
PubMed1998

New experimental approaches in retrovirus-mediated expression screening.

We have established an expression screening system that utilizes retrovirus-mediated gene transfer. The system is based on a high-efficiency packaging cell line BOSC23 and retrovirus vectors pBabeX and pMX which are suitable for cDNA library construction. The combination of BOSC23 packaging cells and the pBabeX and pMX retrovirus vectors produces high-titer recombinant retroviruses, which are able to cover large complexities of cDNA libraries. These retroviruses gave 100% infection efficiency in NIH3T3 cells and 10-100% infection efficiency in various hemopoietic cell lines. In contrast to the conventional mammalian expression cloning system where it is required to transduce cDNA transiently into particular cell types such as COS cells, the retrovirus-mediated expression cloning method allows stable transduction of cDNAs into a wide variety of cell types. This method, therefore, makes it possible to select cells expressing the desired cDNA by various functional assays. In addition, when combined with PCR-driven random mutagenesis, this system is also useful in searching for mutations of various molecules which will result in functional alterations. Other potential applications will also be discussed.

3T3 Cells↗
PubMed1998

Insulin-like growth factor I plays a role in gastric wound healing: evidence using a zinc derivative, polaprezinc, and an in vitro rabbit wound repair model.

BACKGROUND: Although the detailed mechanism is unclear, zinc and its derivative, polaprezinc, have been reported to accelerate gastric ulcer healing in vivo. AIM: To investigate the detailed cellular mechanism of polaprezinc on gastric epithelial cells and fibroblasts with special attention to insulin-like growth factor I (IGF-I). METHODS: Isolated rabbit gastric epithelial cells formed a complete monolayer, from which a circular artificial wound with constant size was made. The restoration process was monitored by measuring wound size up to 48 h. Either polaprezinc, IGF-I, fibroblast conditioned medium or neutralized medium conditioned by anti-IGF-I antibody was added at the time of wounding. The expression of mRNA of IGF-I, hepatocyte growth factor (HGF) and transforming growth factor alpha (TGF-alpha) in fibroblasts with or without polaprezinc treatment was tested using reverse transcription polymerase chain reaction (RT-PCR). Gastric epithelial cell proliferation was also examined by bromodeoxyuridine (BrdU) staining. RESULTS: IGF-I and fibroblast conditioned medium treatment accelerated gastric epithelial restoration which included cell migration and proliferation. However, polaprezinc and neutralized conditioned medium treatment did not accelerate epithelial repair. RT-PCR for growth factor mRNA revealed the IGF-I mRNA expression in fibroblasts was increased after treatment with polaprezinc. CONCLUSION: Polaprezinc induced IGF-I production from mesenchymal cells, resulting in stimulation of epithelial cell restoration through a paracrine pathway. IGF-I may play an important role in gastric wound repair.

Animals↗
PubMed1998

'Chiyamai', a panic-like disorder in woman divers from Hegura Island.

In Hegura Island, Japan, we have recently found female divers who suffer from a disorder called 'Chiyamai'. From interviews, questionnaires and temporarily proposed diagnostic criteria for Chiyamai, nine cases from 44 female divers interviewed, were diagnosed as having Chiyamai. Clinically, Chiyamai is characterized by a panic-like attack. Ten symptoms were observed during a panic-like attack, compared with 13 symptoms in a panic attack described in the DSM-IV. The average age at onset was 30 years and the average duration of illness was approximately 26 years. Several cases were so severe that the patients were unable to continue diving. Additionally, we report a typical case of Chiyamai, and discussed the similarities and differences between Chiyamai and anxiety disorders in the DSM-IV. We suggest that Chiyamai is a panic-like disorder specific to female divers from Hegura Island and that it is a result of heavy diving.

Adult↗
PubMed1998

A possible association between paternal longevity and major depression among elderly men.

Ancestral longevity is sometimes thought to contribute to psychosocial well-being in late life. The present paper aims to examine if parental longevity is associated with mental health among the elderly. The age at death of the parents was compared between 68 patients with major depression who were aged 65 or over and 40 subjects of the same age range without any history of psychiatric disorder. Cox regression revealed that the fathers of the elderly men with unipolar depression died at a significantly younger age than those of the control group. Several hypotheses are advanced to explain this unexpected and intriguing association.

Age Factors↗
PubMed1998

Sex differences in marital and social adjustment.

A sample of 67 married Japanese men and 79 married Japanese women, ranging in age from 25 through 85 years, were interviewed to clarify the relationship between marital adjustment and social adjustment. For the whole sample, the total score of the Short Marital Adjustment Test (SMAT; Locke & Wallace, 1959) and its subcategories, dyadic consensus and satisfaction, was significantly correlated with 5 subcategory scores of the Social Adjustment Scale-II (SAS-II; Weissman, 1978): household adjustment (except the spouse), external family adjustment, work adjustment, social leisure adjustment, and general adjustment. These correlations were present also for the women; for the men, they were present only for social leisure adjustment and general adjustment. Among men, the dyadic consensus scores of the SMAT had stronger correlations with the social adjustment scores; among women, correlations with the marital satisfaction scores of the SMAT were stronger. Thus, marital adjustment may be a part of social adjustment for women, but the two may be discrete for men.

Adult↗
PubMed1998

Relationship of order and number of siblings to perceived parental attitudes in childhood.

Despite the increasingly recognized link between perceived parenting behavior and the onset of psychopathology in adults, studies of the possible determinants of perceptions of parenting behavior are rare. In a sample of 1,145 pregnant Japanese women, correlations were examined between the numbers and sexes of siblings and perceived rearing practices, as rated by the Parental Bonding Instrument (PBI; Parker, Tupling, & Brown, 1979). The participants with more elder sisters viewed their parents' attitudes as less caring, whereas those with more brothers, particularly younger brothers, viewed their parents' attitudes as less overprotective. However, the proportion of the variance of all the PBI scores explained by different types of siblings was very small.

Adult↗