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T Seki

Publications and source records attributed to T Seki.

At least 19 recordsLinked to original sources
PubMed1995

In vitro development of Xenopus skin glands producing 5-hydroxytryptamine and caerulein.

The granular glands of amphibian skin synthesize and store a large amount of bioactive amines and peptides which are structurally similar to mammalian brain-gut peptides. To investigate the development of peptide- and amine-producing cells in the granular glands, pieces of dorsal skin taken at various stages from Xenopus laevis tadpoles were cultured, and the contents of caerulein and 5-hydroxytryptamine (5-HT) were measured. When pieces of skin from tadpoles at stages 57 to 60 (Nieuwkoop and Faber stages) were cultured in a medium containing 10% fetal calf serum (FCS medium) or one containing FCS treated with charcoal (chFCS medium), the caerulein and 5-HT levels were increased for the six days of the incubation period. The caerulein content was lower in the chFCS medium than in the FCS medium. Addition of thyroxine to the chFCS medium had no significant effect on the caerulein content. These results show that the caerulein- and 5-HT-producing cells of the granular glands can develop in a culture system with FCS- or chFCS-containing media, and suggest that FCS contains substances which are absorbed by charcoal and stimulate development of the amine- and peptide-producing cells of the glands. In a preliminary search for correlation between caerulein and 5-HT synthesis, addition of 5-hydroxytryptophan (5-HTP), a precursor to 5-HT, to the FCS medium increased 5-HT content and, conversely, caused significant decrease in caerulein content, suggesting that accumulation of caerulein in the granular glands is influenced by the amount of 5-HT synthesis. These studies indicate that this culture system is a useful model for investigating the development of peptide- and amine-producing cells.

5-Hydroxytryptophan↗
PubMed1995

Characterization of the antigenic specificity of four different anti-(alpha 2-->8-linked polysialic acid) antibodies using lipid-conjugated oligo/polysialic acids.

A rapid, sensitive, and facile method for screening and characterizing anti-polysialic acid (polySia) antibodies using lipid-conjugated oligo/polysialic acids (oligo/polySia) was developed, which is based on an enzyme-linked immunosorbent assay. Homooligo/polymers of alpha 2-->8-linked N-acetylneuraminic acid (Neu5Ac), N-glycoly-neuraminic acid, and 2-keto-3-deoxy-D-galacto-nononic acid (KDN) were conjugated with phosphatidylethanolamine dipalmitoyl (PE) by reductive amination to prepare neo-oligo/polysialoglycolipids (oligo/polySia-PE). Using this method, the anti-polySia equine antibody, H.46, bound to (-->8Neu5Ac alpha 2-->)n-PE, where n = 9 or more residues, a result in confirmation of previous binding studies using radiolabeled oligo/polyNeu5Ac. The antigenic specificity and sensitivity of two monoclonal anti-poly/oligoNeu5Ac antibodies (mAb.12E3 and mAb.5A5) and one anti-oligoKDN antibody (mAb.kdn8kdn), were also determined. mAb.12E3 could detect as little as 25 pg/well of oligo/polyNeu5Ac-PE, while 0.4 ng/well of oligo/polyNeu5Ac-PE to be detected. mAb.kdn8kdn detected as little as 12 ng/well of oligoKDN-PE. Using a series of oligo/polySia-PE with defined degrees of polymerization (DP), the minimum chain length for immunoreactivity of the anti-polySia antibodies was determined to be: DP 5 for mAb.12E3; DP 3 for mAb.5A5; DP 2 for mAb.kdn8kdn; and DP 8 for H.46. Thus, mAb.12E3 and mAb.5A5 recognize shorter oligomers of Neu5Ac than H.46, a finding that is of practical value for identifying shorter oligoSia chains in glycoconjugates. Because mAb.12E3 and mAb.5A5 also recognize extended polySia chains, these antibodies cannot be used, however, to differentiate between short and long chains of polySia when both are expressed on the same molecule.

Animals↗
PubMed1995

A giant nucleopore protein that binds Ran/TC4.

Ran/TC4 is a small nuclear G protein that forms a complex with the chromatin-bound guanine nucleotide release factor RCC1 (ref. 2). Loss of RCC1 causes defects in cell cycle progression, RNA export and nuclear protein import. Some of these can be suppressed by overexpression of Ran/TC4 (ref. 1), suggesting that Ran/TC4 functions downstream of RCC1. We have searched for proteins that bind Ran/TC4 by using a two-hybrid screen, and here we report the identification of RanBP2, a novel protein of 3,224 residues. This giant protein comprises an amino-terminal 700-residue leucine-rich region, four RanBP1-homologous (refs 9, 10) domains, eight zinc-finger motifs similar to those of NUP153 (refs 11, 12), and a carboxy terminus with high homology to cyclophilin. The molecule contains the XFXFG pentapeptide motif characteristic of nuclear pore complex (NPC) proteins, and immunolocalization suggests that RanBP2 is a constituent of the NPC. The fact that NLS-mediated nuclear import can be inhibited by an antibody directed against RanBP2 supports a functional role in protein import through the NPC.

Amino Acid Sequence↗
PubMed1995

RanBP1, a Ras-like nuclear G protein binding to Ran/TC4, inhibits RCC1 via Ran/TC4.

A human protein that is 92% identical and 97% homologous at the amino acid level to RanBP1 from mouse was identified by the two-hybrid method, using two types of target cDNAs fused to sequences encoding the GAL4 DNA-binding domain. The target cDNAs encoded the human Ran/TC4 and human RCC1 proteins, respectively. An in vitro binding experiment showed that RanBP1 binds to RCC1 with the aid of Ran. Partially purified, GST-fused RanBP1 inhibited RCC1-stimulated guanine nucleotide release from Ran in vitro. Consistent with this in vitro finding, overproduction of human RanBP1 was detrimental to growth of tsBN2, a temperature-sensitive BHK21 hamster cell line defective in the RCC1 gene, and inhibited the growth of the Saccharomyces cerevisiae rcc1 mutants prp20, mtr1 and srm1. The specific effect of RanBP1 on rcc1- cells was confirmed by the finding that overproduction of RanBP1 induces significant levels of expression of a FUS1-lacZ gene and an increase in mating efficiencies in a ste3, pheromone receptor-deficient yeast mutant. This phenotype is similar to the srm1, a mutant isolated as a suppressor that restores mating to receptorless mutants. These findings indicate that RanBP1 negatively regulates RCC1.

Amino Acid Sequence↗
PubMed1995

Lewis Y antigen expression in hepatocellular carcinoma. An immunohistochemical study.

BACKGROUND: The altered expression of the Lewis blood group-related antigens during malignant transformation can be used clinically as a tumor marker or as a prognostic indicator. The Lewis Y (LeY) antigen, which is one of the Type 2 human blood group-related antigens, also is thought to behave as an oncodevelopmental cancer-associated antigen. In this study, the authors examined the association between human LeY antigen expression and the clinicopathologic features of HCC, including its proliferative activity. METHODS: Forty-six histologically confirmed cases of HCC were studied retrospectively. Liver biopsy specimens from the main tumor of each case were obtained under ultrasonic guidance before treatment was initiated. The formalin fixed, paraffin embedded serial sections were immunostained using a modification of the avidin-biotin-peroxidase complex method, with a primary monoclonal antibody (MoAb) directed against the LeY antigen (BM-1/JIMRO). The relationship between LeY antigen expression and the HCC's proliferative activity was analyzed similarly by immunohistochemical methods using a primary MoAb directed against the Ki-67 antigen (MIB 1). In addition, to clarify the relationship between LeY antigen expression and the histologic heterogeneity within HCC, seven cases of surgically resected HCC also were immunostained. RESULTS: The LeY antigen was detected on the membrane and in the cytoplasm of the cancer cells. Of the 46 HCC cases, 20 (43.5%) expressed the LeY antigen in the tumor cells. There was no correlation between LeY antigen expression and the maximum tumor dimension or the Stage. However, the incidence of LeY antigen-positive cases in poorly differentiated HCCs was found to be significantly higher than that in well or moderately differentiated HCCs (P < 0.01). In resected HCC cases, LeY antigen expression within HCC nodules was frequently greater in the less differentiated tumor than in adjacent differentiated tumor. Moreover, the incidence of LeY antigen expression in alpha-fetoprotein (AFP)-positive (AFP > or = 200 ng/ml) HCC cases was significantly higher than that in AFP-negative (AFP < 200 ng/ml) HCC cases (P < 0.05). Furthermore, the mean value of the Ki-67 labeling index in LeY antigen-positive HCC cases (25.2 +/- 11.3%) was significantly higher than that in LeY antigen-negative HCC cases (9.4 +/- 4.1%) (P < 0.001). CONCLUSIONS: These results suggest that LeY antigen expression correlated closely to the dedifferentiation and proliferative activity of HCC.

Antibodies, Monoclonal↗
PubMed1995

In vivo occurrence of p16 (MTS1) and p15 (MTS2) alterations preferentially in non-small cell lung cancers.

Frequent homozygous deletions of the p16 (MTS1) gene encoding a cyclin-dependent kinase inhibitor were recently reported in various tumor cell lines including examples derived from lung cancers, but direct evidence for their occurrence in lung cancer patients has not been reported thus far. In the present study, alterations of p16 and/or p15, a p16-related cyclin-dependent kinase, were observed not only in lung cancer cell lines but also in the corresponding tumor specimens in vivo, excluding the possibility of in vitro artifacts. Interestingly, a clear specificity was also noted in terms of the affected histological subtype; i.e., only non-small cell lung cancers carried alterations (6 of 20 as compared to 0 of 20 small cell lung cancer cell lines).

Base Sequence↗
PubMed1995

Straying phenomenon of migrating LHRH neurons and highly polysialylated NCAM in the chick embryo.

The present study on unilaterally incompletely placodectomized chick embryos revealed that arrival of migrating LHRH neurons into the forebrain area is dependent on the presence of a central projection of the olfactory nerve. When a fragment of the lateral and medial olfactory epithelium was spared the damage, a small number of LHRH-ir cells were found to migrate into the forebrain along a thin NCAM-H-expressing fiber bundle of the olfactory nerve. In embryos with large lesions which destroyed the lateral olfactory epithelium, the poorly developed NCAM-H-positive olfactory nerve fibers were arrested where they meet the NCAM-positive medial nasal branch of the ophthalmic nerve and frequently fused with this branch fiber bundle. In these embryos, no LHRH-ir cells were detected in the forebrain area. They were deviated from their regular migratory course to the NCAM-H-positive medial nasal branch fiber bundle. This straying phenomenon indicates that some structural support is apparently needed for the migration of LHRH-ir cells, but their migratory route is not completely programmed in their precursor cells in the olfactory placode. In cultures of placodal tissues, the coexistence of migrating LHRH-ir cells with NCAM-H-expressing neural elements was always confirmed. It is suggested therefore that not only the structural support for the migration but also the interaction between LHRH-ir cells and NCAM-H-expressing neural elements is a prerequisite for successful LHRH neuronal migration.

Animals↗
PubMed1995

Sequence analysis and characterization of FAR-17c, an androgen-dependent gene in the flank organs of hamsters.

This study reports on the isolation and characterization of a cDNA clone, regulated by androgen transcriptionally, in male Golden hamsters' flank organs. Previous studies have reported on the cloning of an androgen-dependent gene, FAR-17a, from the same hamster organ. After castration, the FAR-17c transcription rate decreases faster than FAR-17a but is not suppressed completely. The recovery of transcription by androgen injection is also faster than FAR-17a. In male hamsters, it is expressed strongly in the sebaceous glands and liver, and weakly in the lungs and brain. It has never been expressed in the testes. In the female, it is strongly expressed in the liver and brain and weakly in the lungs and flank organs. Sequence analysis shows that FAR-17c has a long 1062 bp open reading frame and its deduced amino acid sequence (354 residues) is highly homologous to the stearyl-CoA desaturases of the rat liver and mouse adipocytes. Stearyl-CoA desaturase, either in the liver or adipocytes appears to be independent of androgen regulation. Since stearyl-CoA desaturase plays a key role in fatty acid metabolism, further studies on its regulation by androgen are warranted in relation to acne vulgaris.

Amino Acid Sequence↗
PubMed1995

Reproducibility of subjectively graded voluntary isometric muscle strength in unilateral and simultaneous bilateral exertion.

Reproduction error of voluntary isometric muscle strength that was graded subjectively by the subject was investigated under unilateral and bilateral conditions. Six kinds of tasks, i.e. elbow flexion, elbow extension, hand grip, second digit abduction, knee extension and leg extension were employed. It was clear that absolute error (AE) increased with increase of exerted muscle strength in both unilateral and bilateral conditions. Mean of AE in each task was 4-5% of maximal muscle strength in the task in unilateral conditions. Algebraic or constant error (CE) decreased with increase of exerted strength. Demands for smaller strength tended to overshoot and larger ones tended to undershoot. In bilateral conditions when the different levels of strength for each limb were required to be exerted, AE on the weaker side tended to be larger than that in unilateral conditions. Thus a possibility that magnitude of AE might be affected by amount of attention was suggested. The subjectively graded criterion strength for a specific required level, when the strength was expressed as relative to the maximal strength, was almost the same in every task within a subject although it was different between subjects. It is suggested that each subject might have an awareness of relative magnitude of exerted strength.

Arm↗
PubMed1995

Effects of topically applied spironolactone on androgen stimulated sebaceous glands in the hamster pinna.

The effects of spironolactone (5% SYC-201G, a preparation developed for clinical use in acne vulgaris by Searle Yakuhin K.K.), which is known to have antiandrogenic effects by competitively inhibiting dihydrotestosterone at androgen receptor sites, was topically applied to the androgen stimulated sebaceous glands of adult female golden hamsters. Androgen stimulation, induced by intramuscular injection of testosterone propionate (TP) every other day over a two week period, resulted in a 2.5 to 2.7 time increase in the size of the sebaceous glands of the hamster pinna. Once-daily treatment with 5% SYC-201G or matching placebo was applied to androgen-stimulated hamsters on one pinna only during the same period as TP injection. Comparison between the treated and untreated sides revealed a significant suppression in the sebaceous gland size (p < 0.05) by 5% SYC-201G; no such effect was observed with placebo. The difference in the suppression rate of the sebaceous gland size between 5% SYC-201G (23%) and matching placebo (-4.7%) was significant (p < 0.01).

Administration, Topical↗
PubMed1995

Strain combination-dependent genesis of necrotizing arteritis in anti-ICAM-1 antibody-perfused renal allografts in the rat.

Rat kidneys were perfused with anti-intercellular adhesion molecule-1 (anti-ICAM-1) monoclonal antibody prior to allotransplantation. In the two strain combinations examined, LEF-to-WKAH transplants resulted in accelerated graft loss, and no prolongation of graft survival. The accelerated graft loss was the result of frequent occurrence of necrotizing arteritis within the grafts. In contrast, TO-to-WKAH transplants resulted in no change in graft survival and no arteritis. Necrotizing vasculitis in the LEJ-to-WKAH grafts was characterized by fibrinoid necrosis, collection of cellular infiltrates and serum macromolecular protein entrapment. The F(ab1)2 form of anti-ICAM-1 antibody partially preserved the antibody's capacity to accelerate graft loss. Therefore, although endothelial injury by Fc-mediated cytotoxicity may be involved in vascular damage, other mechanisms also come into play. The amount and distribution pattern of ICAM-1 antigen were identical in both TO and LEJ strains. Intravenous anti-ICAM-1 antibody administration combined with lipopolysaccharide, Poly(I)-Poly(C), warm ischemia to the kidney, or subcutaneous immunization with allogeneic spleen cells, but without renal transplantation, did not generate necrotizing vasculitis or proteinuria. These observations plus our previous data on the rat liver transplantation model clearly show that graft perfusion with anti-ICAM-1 monoclonal antibody invokes extensive vascular damage within allografts by Fc-mediated and Fc-independent mechanisms, depending on the donor-to-host combination.

Animals↗
PubMed1995

Prediction of prognosis of primary biliary cirrhosis in Japan.

The clinical profile of primary biliary cirrhosis in Japan was clarified on the basis of data on 1066 patients attending 212 hospitals and institutions in this country. Six hundred and twelve patients (57.4%) were asymptomatic. The majority of the patients were middle-aged women. Pruritus was the most frequent initial symptom of symptomatic primary biliary cirrhosis. Antimitochondrial antibodies were positive in 877 patients (82.5%). Sjögren's syndrome was the most common associated autoimmune disease. Liver biopsy was performed in 753 patients at the time of diagnosis, and histological staging by Scheuer's classification indicated that 307 (43.7%) patients were in stage I and 222 (31.6%) were in stage II. The most frequent causes of death were hepatic failure and/or gastrointestinal bleeding, which affected 166 (78.3%) of the 212 patients who died. Statistical analysis using Cox's regression method revealed that the patient's age and the serum bilirubin, albumin, and total cholesterol concentrations were significant predictors of the prognosis. A prognostic index was also calculated that could be used to predict the duration of survival for patients with primary biliary cirrhosis.

Adult↗
PubMed1995

Studies on agents with vasodilator and beta-blocking activities. II.

A series of phenoxypropanolamines having a hydrazinopyridazinyl moiety was synthesized. Their hypotensive and beta-blocking activities were evaluated after intravenous administration of the compounds to anesthetized rats. Some of them exhibited both activities. In particular, compound 20k is a candidate for clinical use due to its hypotensive activity, equal to that of hydralazine, and its beta-blocking activity, 2.7-fold more potent than that of propranolol.

Adrenergic beta-Antagonists↗
PubMed1995

Effect of 15-deoxyspergualin (DSG) on rat kidney allograft: immunological mechanisms implicated in prolonged survival.

PURPOSE AND METHODS: The effect of short-term administration of 15-deoxyspergualin (DSG), 5 mg./kg./day from postoperative days 4 to 7, on rat renal transplantation was studied. RESULTS: Although allografts treated with DSG survived longer than nontreated ones, cellular infiltration in both grafts did not differ. However, renal tubular cells of DSG-treated grafts proliferated well and escaped apoptotic cell death. A donor-specific tolerance 2 weeks after transplantation was developed, and cells with in vitro suppressor function were induced in such animals. CONCLUSIONS: Treatment with DSG appears to prevent lethal attack of effector cells on tubular cells in situ and to generate suppressor cells in the maintenance phase of graft enhancement.

Animals↗
PubMed1995

[Lysozyme].

In the first section the assay methods of lysozyme are reviewed. It is pointed out that there is no method using the hydrolysis of NAM- > beta-1, 4-glycoside bond- > NAG, So to clarify relation between methods will lead to discovery of new isozymes. In the second chapter serum or urinary lysozyme levels are discussed in the states of diseases. The high levels are induced by cell proliferation which are producing lysozyme. The type of cells and their nature may infer different lysozymes that has no clear evidences yet. In the third part lysozyme is reviewed as protein and product of gene. In the final, enzyme kinetics are the subject of investigation, and further studies may by chance conduct us to find out new isozymes of lysozyme in near future.

Bacterial Infections↗
PubMed1995

[A study of the intraorbital blood flow using ultrasound color Doppler mapping images in optic canal fracture cases].

Ultrasound color Doppler flow mapping image (CFMI) equipment, SSA-270A (Toshiba Co) was used to measure the blood flow velocity of the ophthalmic artery (OA) and the central retinal artery (CA) in eyes with optic canal fracture. The maximal blood flow velocity (V max), the minimal blood flow velocity (V min), the mean blood flow velocity (V mean), and the resistance index (RI) before and after transethmoidal decompression of the optic nerve were compared. The examination was conducted on 13 patients. There was no difference in blood flow velocity in the CA after the operation. Pre-operative V max and RI of the OA in the damaged eyes were lower than in normal eyes, but they increased the day after the operation. We measured the intraorbital blood flow velocity by CFMI because ultrasound does not penetrate bone. Since the peripheral artery from the optic foramen did not change after the operation, we concluded that the peripheral blood flow of OA had been quantitatively improved by the trans-ethmoidal decompression of the optic nerve.

Adolescent↗