Search PubMed⌕ Search

Biomedical subjects

K Kasai

Publications and source records attributed to K Kasai.

At least 235 records · Page 13Linked to original sources
PubMed1993

The family of metazoan metal-independent beta-galactoside-binding lectins: structure, function and molecular evolution.

Animal metal-independent beta-galactoside-binding lectins were initially found in vertebrates, but they have recently been isolated from much lower invertebrates, such as nematode and sponge, as well. Further, an eosinophilic lysophospholipase associated with various inflammatory reactions was very recently found to be a new member of this protein family. It appears that beta-galactoside-binding lectins and some non-lectin proteins form a superfamily whose members are widely distributed from vertebrates to invertebrates. From the viewpoints of protein architecture, the superfamily members can be subdivided into three types; i.e. 'proto type' (the relatively well-studied 14 kDa lectins), 'chimera type' (29-35 kDa lectins also known as epsilon BP/CBP35/Mac2/laminin-binding protein) and 'tandem-repeat type' (a newly found nematode 32 kDa lectin). Comparison of their amino acid sequences and mutagenesis studies have suggested the functional importance of some conservative hydrophilic residues (His44, Asn46, Arg48, Glu71 and Arg73 of human 14 kDa lectin). Several non-charged residues (Gly14, Phe45, Pro47, Phe49, Val59, Trp68, Pro78 and Phe79) are also well conserved, and are probably important to maintain the structural framework of these proteins. A consideration of molecular evolution suggests that lectins belonging to this family probably existed in the Precambrian era. Ubiquitous occurrence of these homologous lectins with shared sugar specificity suggests that they are involved in 'essential minimum' functions of multicellular animals, possibly in cooperation with their partner glycoconjugates.

Amino Acid Sequence↗
PubMed1993

Bladder wall morphology: in vitro MR imaging-histopathologic correlation.

To study the morphology of the normal and inflamed bladder wall, the findings of magnetic resonance imaging and histopathologic examination of 13 in vitro specimens were correlated. Normal bladder wall appeared as a band of intermediate signal intensity on T1-weighted images and as bands of low (inner) and intermediate (outer) signal intensity on T2-weighted images. Inflamed bladder walls demonstrated two additional inner bands of intermediate (inner) and high (innermost) signal intensity on T1-weighted images and high (inner) and low (innermost) signal intensity on T2-weighted images. The mean histopathologic percentages of muscle bundles in inner and outer bands that appeared on T2-weighted images were 92.5% +/- 4.9 and 78.3% +/- 8.2, respectively. The authors conclude that the total thickness of the two bands of differing intensity that appeared on the T2-weighted images of the normal bladder wall correlated well morphometrically with the muscle layers in the histopathologic specimens, and that the different signal intensities in the muscle layer represent a compact inner and looser outer arrangement of smooth muscle bundles.

Aged↗
PubMed1993

A case of pheochromocytoma of the urinary bladder in a long-term hemodialysis patient.

The development is reported of a pheochromocytoma of the urinary bladder in a 33-year-old patient with systemic lupus erythematosus who had undergone long-term hemodialysis. A hypertensive episode followed by defecation was demonstrated by the monitoring of blood pressure with a portable automated sphygmomanometer without elevation of plasma catecholamines. The tumor was surgically removed and normalization of the patient's blood pressure followed. Thus, monitoring of blood pressure for 24 h proved useful for the diagnosis of pheochromocytoma and, in particular, of paroxysmal hypertension.

Adult↗
PubMed1993

White pulp reconstitution after human bone marrow transplantation.

To reveal the reconstitution process of the white pulp after bone marrow transplantation (BMT), spleens of 24 marrow recipients whose survival times ranged from 34 to 303 days after BMT, were analyzed at the histopathological and immunohistochemical level. Up to 3 months after BMT, the white pulp was atrophic and consisted mainly of T cells forming periarteriolar lymphatic sheaths (PALS). Approximately 100 days after BMT, B cells aggregated in some of the white pulp, forming primary follicles, whereas marginal zones could not be detected. Beyond 4 months after BMT, the PALS, the lymphoid follicle, and the marginal zone of the white pulp could be seen in most of the recipients' spleens. However, the recovery of the marginal zone was poor up to 10 months after BMT. Thus, the white pulp was reconstituted sequentially, beginning in the PALS, followed by reconstitution in lymphoid follicles, and finally in the marginal zone. The development of the PALS corresponded well with the appearance of interdigitating dendritic cell, as did the development of lymphoid follicles with the appearance of follicular dendritic cell. The sequential reconstitution of the white pulp demonstrated in this study provides the morphological basis for the functional immune recovery of marrow recipients. In particular, the delay of the marginal zone reconstitution seems to be responsible for the functional asplenia of long-term survivors.

Adolescent↗
PubMed1993

Comparative study of craniofacial morphology in Japanese and Australian aboriginal populations.

A metric study of 71 Japanese and 106 Australian aboriginal precontemporary crania was undertaken using direct measurements and cephalograms. Compared with Australian aboriginals, the Japanese are characterized by smaller cranial length, cranial base length, nasal floor length, palatal length, mandibular dimensions (except symphysis height), facial depth, posterior face height, and facial profile angle and larger cranial breadth and height, maxillary breadth, palatal breadth, anterior face height, and occlusal and mandibular plane angles. These differences confirm the previously described brachycephalic tendency in aboriginals and the dolichocephalic form in the Japanese. The differences are also consistent with the expected functional differences between the Australian aboriginal hunter-gatherer group masticating more resistant food with larger, more anteriorly located, more powerful masseter muscles and the Japanese group masticating less resistant food with correspondingly less robust masticatory musculature. The results highlight the differences in craniofacial morphology between groups with different genetic backgrounds subjected to significantly different environmental influences.

Adolescent↗
PubMed1993

[A case of T-cell lymphoma showing multiple nodular shadows and an elevated titer of human T-lymphotropic virus type I (HTLV-I) antibody].

A 42-year-old man, born in Chiba prefecture, was admitted to our hospital because of multiple nodular shadows on chest X-ray film and an elevated titer of human T-lymphotropic virus type I (HTLV-I) antibody. The pulmonary lesion was diagnosed as T-cell lymphoma by open lung biopsy. There has been only one previous report of T-cell lymphoma showing multiple nodular shadows on chest X-ray. The elevated titer of HTLV-I antibody strongly suggested that the present case was one of adult T-cell lymphoma.

Adult↗
PubMed1992

Evidence that Caenorhabditis elegans 32-kDa beta-galactoside-binding protein is homologous to vertebrate beta-galactoside-binding lectins. cDNA cloning and deduced amino acid sequence.

We have cloned a full-length cDNA for a beta-galactoside-binding protein with a relative molecular mass of 32 kDa (32-kDa GBP), recently purified from a nematode, Caenorhabditis elegans (Hirabayashi, J., Satoh, M., Ohyama, Y., and Kasai, K. (1992) J. Biochem. 111, 553-555). The clone contained a single open reading frame encoding 279 amino acids, including the initiator methionine. Significant sequence homology to metal-independent beta-galactoside-binding lectins (25-30% identities), which had previously been found only in vertebrates, was observed. Moreover, the nematode 32-kDa GBP proved to have a unique polypeptide architecture; that is, it is composed of two tandemly repeated homologous domains, each consisting of about 140 amino acids. The internal homology was about 32%. Thus, this protein is constructed with a duplicated fundamental unit which is similar to the subunit of vertebrate 14-kDa lectins. In spite of the extreme phylogenic distance between nematodes and vertebrates (divergence greater than 6 x 10(8) years ago), both of the two repeated domains of the nematode 32-kDa GBP retained most of the amino acid residues conserved in vertebrate lectins. This means that members of the metal-independent animal lectin family are distributed much more widely than had been believed: from nematodes to vertebrates. The implication is that proteins belonging to this family have fundamental roles which are not restricted to vertebrates but are common to almost all animals.

Amino Acid Sequence↗
PubMed1992

Trypsin and affinity chromatography.

Affinity adsorbents for trypsin which were prepared by immobilizing product-type ligands, that is, peptides having C-terminal arginine, proved to be effective not only for preparative purposes but also for basic research on molecular recognition. The properties of the binding site of trypsin were revealed by chromatographic experiments. Quantitative analysis based on the theory of frontal affinity chromatography proved to be extremely effective. As an extension of the product-type ligands, peptide argininals were also used and information on the mechanism of action of these inhibitors was obtained. Anhydrotrypsin, which lost the hydroxyl group of Ser183, was found to gain increased binding ability for product-type compounds. This inactivated enzyme was also used as an immobilized ligand and the unique affinity adsorbent thus prepared proved to be extremely effective for the separation of peptides and recombinant proteins based on their C-terminal structures. High-performance affinity chromatography of trypsin and related enzymes using a polymer-based support was also developed.

Animals↗
PubMed1992

Arginine-tail method, an affinity tag procedure utilizing anhydrotrypsin agarose.

The arginine-tail method is a recently developed affinity tag procedure utilizing immobilized anhydrotrypsin for specific enrichment of a recombinant protein. Three model proteins (originally human beta-galactoside-binding lectin with a relative sub-unit molecular mass of 14,000) were prepared by mutagenesis, each of which has a tail of either Arg, Gly-Arg, or Gly-Gly-Arg at the C-terminus. All of them retained their original sugar-binding activity and antigenicity, and became recognizable by anhydrotrypsin. They were adsorbed on an anhydrotrypsin-agarose column at pH 5 after treatment with 4 M urea or 10 mM HCl to expose the C-terminal tails. The adsorbed arginine-tailed lectins were eluted either specifically with benzoylglycylarginine (Bz-Gly-Arg) or with 5 mM HCl. Added arginine was removed by carboxypeptidase B, but very slowly. When urea-denatured Escherichia coli lysate containing one of the arginine-tailed lectins was applied to the column, the lectin was adsorbed together with some host proteins, which are expected to have arginine or lysine at their C-termini. However, more than a ten-fold enrichment was attained by this procedure. The described method would be useful for purifying various recombinant proteins, even those which are inactive as a result of mutagenesis. The smallest tag arginine at the C-terminus should have a minimum effect on both the structure and function of a target protein.

Adsorption↗
PubMed1992

A general transcription initiation factor, human transcription factor IID, overexpressed in human lung and breast carcinoma and rapidly induced with serum stimulation.

A general transcription factor IID which binds to the TATA box promoter element on RNA polymerase II genes regulates and initiates eukaryotic mRNA synthesis. A quantitative polymerase chain reaction procedure was developed and the human transcription factor IID (hTFIID) transcript was measured in normal human tissues, lung carcinomas, lung carcinoma cell lines, and breast carcinomas. In some normal tissues such as liver, fetal lung, and placenta, relatively low to moderate levels of hTFIID mRNA were detected. In contrast, hTFIID transcript was highly expressed in nearly all solid lung carcinomas and cell lines including both small cell lung cancer and non-small cell lung cancer. hTFIID mRNA was present to a greater extent in small cell lung cancer than non-small cell lung cancer in solid tumors and cell lines. In solid carcinomas of breast, overexpression of hTFIID was also detected. A serum induction study using a serum-starved small cell lung cancer cell line, Lu134BS, indicated hTFIID transcription to be rapidly induced at 15 min following stimulation and its response essentially similar to that of protooncogene, c-fos. These results indicate the involvement of the expression of the general transcription factor hTFIID in lung and breast carcinoma, such as being associated with poor differentiation and high mitotic activity.

Base Sequence↗
PubMed1992

Sialosylated Lewis chi expression in CD30-positive anaplastic large-cell lymphomas.

The expression of sialosylated Lewis chi (SLEX), a ligand for endothelial leukocyte adhesion molecule 1 in malignant lymphomas, was immunohistochemically examined, using the monoclonal antibody, CSLEX1, which specifically reacts with SLEX. It was expressed in 6 out of 64 non-Hodgkin's lymphomas, which consisted of 1 nasal large-cell lymphoma and 5 of 8 (62%) Ki-1-positive anaplastic large-cell lymphomas (ALCL). One nasal lymphoma positive for SLEX co-expressed a T cell marker, cluster of differentiation (CD) 5, and natural killer (NK) cell markers such as CD56 and CD16, indicating that SLEX+ nasal lymphoma cells are possibly malignant counterparts of SLEX+ NK cells. SLEX did not react with 30 B cell lymphomas or most Hodgkin's disease lymphomas, though it did with one lymphocyte predominance type. Although SLEX+ ALCL exhibit T cell markers in some cases, some ALCL expressing SLEX may represent histiocytic differentiation of the neoplastic cells. The lymphoma cells of ALCL were preferentially positive for SLEX, in contrast to Hodgkin's disease cells, and thus CSLEX1 in conjunction with CD30 and CD15 should be of use for analyzing and making differential diagnoses of routine paraffin-embedded sections of ALCL.

Antigens, CD↗
PubMed1992

Changes in expression of the endogenous beta-galactoside-binding 14-kDa lectin of chick embryonic skin during epidermal differentiation.

Changes in the expression pattern of the gene for the endogenous beta-galactoside-binding 14-kDa lectin of chick embryo were examined immunohistochemically during epidermal differentiation in vivo and in vitro with special reference to detailed localization of the 14-kDa lectin. The gene expression was visualized by the HRP-staining method following in situ hybridization, in which sulfonated cDNA was employed as a probe. The 14-kDa lectin gene expression (mRNA) was detected mainly in the intermediate layer of the epidermis: it was faint in 13-day-old embryos, gradually increased in intensity during epidermal differentiation, and became intensely positive in 17-day-old embryo. The expression of the gene in skin explants was suppressed by vitamin A, which induces mucous metaplasia of the epidermis in vitro. The anti-14-kDa lectin reaction was positive mainly in the intermediate layer of the differentiating epidermis, coinciding chronologically with expression of the gene at the light microscopic level. Immunoelectron microscopy revealed that the positive reaction was primarily localized in desmosomes, in tonofilament bundles anchored to the desmosomes, along the outer surface of the plasma membrane, and in the intercellular space. Essentially the same staining pattern was observed in differentiating epidermis in vitro. The positive reaction was markedly reduced in the epidermis in which differentiation had been suppressed in vitro by the addition of vitamin A.

Animals↗
PubMed1992

Effects of inorganic iodide, epidermal growth factor and phorbol ester on hormone synthesis by porcine thyroid follicles cultured in suspension.

Porcine thyroid follicles cultured in suspension for 96 h synthesized and secreted thyroid hormones in the presence of thyrotropin (TSH). The secretion of newly synthesized hormones was assessed by determining the contents of thyroxine (T4) and triiodothyronine (T3) in the media and by paperchromatographic analysis of 125I-labelled hormones in the media where the follicles were cultured in the presence and absence of inhibitors of hormone synthesis. The hormone synthesis and secretion was modified by exogenously added NaI (0.1-100 microM). The maximal response was obtained at 1 microM. Thyroid peroxidase (TPO) activity in the cultured follicles with TSH for 96 h was dose-dependently inhibited by NaI. One hundred microM of NaI completely inhibited TSH-induced TPO activity. Moreover, both epidermal growth factor (EGF: 10(-9) and 10(-8) M) and phorbol 12-myristate 13-acetate (PMA: 10(-8) and 10(-7) M) inhibited de novo hormone synthesis. An induction of TPO activity by TSH was also inhibited by either agent. These data provide direct evidences that thyroid hormone synthesis is regulated by NaI as well as TSH at least in part via regulation of TPO activity and also that both EGF and PMA are inhibitory on thyroid hormone formation.

Animals↗
PubMed1992

Effects of epidermal growth factor, phorbol ester, and retinoic acid on hormone synthesis and morphology in porcine thyroid follicles cultured in collagen gel.

Epidermal growth factor (EGF), phorbol esters (PEs), and retinoic acid (RA) inhibit differentiated functions of thyrocytes. In the present study the inhibitory effects of these growth-promoting factors on hormone synthesis were studied in thyroid follicles cultured in type-I collagen gel, and morphologic alteration by these factors was examined by light and electron microscopy (EM). Porcine open thyroid follicles obtained by treatment with 0.1% collagenase were embedded in collagen gel and cultured in Ham's F12 medium supplemented with 6H (insulin, hydrocortisone, somatostatin, transferrin, glycyl-his-lys, and thyrotropin) + 0.5% fetal bovine serum (FBS). After 1 week these open follicles developed to closed follicles, and the medium was changed to one containing 6H + 0.5% FBS + 0.1 microM sodium iodide (NaI). Some media were supplemented with either EGF, phorbol 12-myristate 13-acetate (PMA), or all-trans RA. The closed follicles retained ability for hormone synthesis for 2 weeks after the medium change in the presence of 6H + FBS + NaI. The amounts of T4 and T3 secreted into the culture medium from day 9 to day 12 after the medium change were 60% and 45% of those from day 0 to day 4, respectively. EGF reduced production of T4 and T3 by 61% and 69%, respectively; PMA, by 87% and 99%; and RA, by 55% and 44%. In the medium supplemented with 6H + 0.5% FBS, the follicles exhibited intact polarity. Apical surfaces with microvilli were oriented to the follicular lumen and tight junctions were on the apical side of cell-to-cell contacts. Desmosomes were found on both the apical and basal halves of the cell contacts.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Purification and characterization of beta-galactoside-binding proteins from Caenorhabditis elegans.

Two carbohydrate-binding proteins (subunit molecular masses, 32 and 16 kDa, respectively) were isolated for the first time from a nematode, Caenorhabditis elegans. They were specifically extracted with lactose and adsorbed on asialofetuin-Sepharose in the absence of a metal ion. Although these two proteins were co-eluted from a gel filtration column at a position corresponding to an apparent molecular size of 30 kDa under non-denaturing conditions, they could be separated by reversed-phase chromatography. The 32 kDa protein, the main component, was further characterized. Together with its solubility, saccharide specificity and metal independence, some other structural properties, including its amino acid composition, UV spectrum, and partial amino acid sequence, strongly suggested that the 32 kDa protein is a member of a class of soluble beta-galactoside-binding lectins which had previously been only found in vertebrates.

Amino Acid Sequence↗