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Biomedical subjects

H Masutani

Publications and source records attributed to H Masutani.

At least 91 records · Page 5Linked to original sources
PubMed1991

Coexpression of adult T-cell leukemia-derived factor, a human thioredoxin homologue, and human papillomavirus DNA in neoplastic cervical squamous epithelium.

Adult T-cell leukemia-derived factor (ADF) is an autocrine interleukin-2 receptor-inducing factor produced by human T-lymphotropic virus-1 (HTLV-1)-transformed lymphocytes, which has a high structural homology with an endogenous dithiol reducing coenzyme, thioredoxin. Its localization was investigated immunohistochemically in the cervix, using normal tissue (27 samples) and squamous neoplastic tissue (three condylomas, 42 cervical intraepithelial neoplasia [CIN] samples, 34 invasive squamous cell carcinoma samples). The expression of human papillomavirus (HPV) DNA was also studied in serial sections of the same subjects. Normal squamous cells and glandular cells of the cervix were negative for ADF. However, intracytoplasmic and/or intranuclear ADF-positive cells were usually found in the intermediate and superficial layers of the neoplastic squamous epithelium of condylomas (three of three cases) and CIN (35/42 cases). HPV DNA was detected in all condylomas and in 27 of 42 CIN specimens. HPV DNA-positive cells were usually localized in the intermediate and superficial layers of the neoplastic squamous epithelium. These HPV DNA-positive cells were also positive for ADF. Invasive squamous cell carcinoma was also positive for ADF (24/34 cases) and HPV DNA (11/34 cases). The coexpression of HPV DNA and ADF was observed in all HPV DNA-positive cases. Coexistence of HPV DNA and ADF immunopositivity in neoplastic squamous cells of the cervix suggests that ADF expression closely reflects the intracellular event on HPV DNA replication.

Adult↗
PubMed1991

Purification and characterization of phytase from rat intestinal mucosa.

Phytase (myo-inositol hexakisphosphate phosphohydrolase; EC 3.1.3.8 or 3.1.3.26) was purified from rat intestinal mucosa. The purified enzyme preparation exhibited two protein bands on SDS-polyacrylamide gel electrophoresis with estimated molecular masses of 70 kDa and 90 kDa. Rabbit antisera prepared against the 90K subunit cross-reacted with the 70K subunit on immunoblotting. The peptide maps of the 70K and 90K subunits were similar, and the N-terminal amino acid sequences of the two subunit proteins were almost identical. Treatments to remove sugar moieties from the proteins showed that the two subunit proteins had different oligosaccharide chains, although the difference in their molecular masses was not due to the difference in their oligosaccharide compositions. The purified enzyme also showed activity of alkaline phosphatase (orthophosphoric monoester phosphohydrolase; EC 3.1.3.1), but the properties of the two enzyme activities were different; the optimum pH for phytase activity was 7.5, while that for alkaline phosphatase was 10.4. Phytase activity did not necessarily require divalent cations, while Mg2+ was essential for alkaline phosphatase activity. Phenylalanine, a specific inhibitor of intestine-type alkaline phosphatase had no effect on the phytase activity.

6-Phytase↗
PubMed1991

Immunohistochemical localization of adult T-cell leukaemia-derived factor, a human thioredoxin homologue, in human fetal tissues.

An immunohistochemical study of the expression of adult T-cell leukaemia-derived factor (ADF), a human thioredoxin homologue, was performed using a rabbit antibody against the C-terminal peptides of ADF. Tissues were obtained from human fetuses between 9 and 23 weeks of gestation. It was revealed that ADF was widely distributed in different organs and tissues during the fetal period. The ADF antibody reacted selectively with medullary cells of the thymus, lung epithelium, the epithelium of the digestive tract, hepatocytes, bladder epithelium, peripheral nerve cells, hair follicles, sebaceous glands, osteoblasts and the proximal tubules of the kidney. It also reacted with cells destined to differentiate into ciliated cells in the fallopian tube and efferent ductules of the testis, interstitial cells in the ovary, Leydig cells of the testis, and dendritic cells in the spleen and lymph nodes. This is the first report on the thioredoxin system in human cells during the early fetal period. The selectivity of ADF staining in fetal tissues suggests that, during early fetal life, ADF expression correlates well with the cellular function of certain tissues.

Cytokines↗
PubMed1991

Vestibular aqueduct in Menière's disease and non-Menière's disease with endolymphatic hydrops: a computer aided volumetric study.

The volume of the vestibular aqueduct was studied by a computer-aided volumetric method in 9 temporal bones with endolymphatic hydrops from individuals with Menière's disease (MD), 7 temporal bones with endolymphatic hydrops from individuals without a history of Meniere's disease (non-MD hydrops), and 10 normal temporal bones (controls) to investigate the cause of endolymphatic hydrops in both MD and non-MD hydrops. A hypoplastic vestibular aqueduct was found significantly more often in the MD group than in either the non-MD hydrops group (chi 2-test, chi 2 = 4.063, p less than 0.05) or the control group (chi 2-test, chi 2 = 6.363, p less than 0.05). The difference in volume between the non-MD hydrops group and the control group was not significant. It is speculated that a small vestibular aqueduct (presumably containing a small endolymphatic sac) might be a predisposing factor in Menière's disease. In contrast, in non-MD hydrops, there seems to be no correlation of endolymphatic hydrops with a hypoplastic vestibular aqueduct and endolymphatic sac.

Adult↗
PubMed1991

Adult T cell leukemia derived factor (ADF) in oral epithelial lesions.

To examine the distribution of adult T cell leukemia derived factor (ADF) in oral epithelial lesions, an immunohistochemical method using a polyclonal antibody against ADF C-terminal peptide was applied to formalin fixed and paraffin embedded tissues. All cases of periodontitis, epithelial hyperplasia, epithelial dysplasia and leukoplakia examined stained positively for ADF. Immunoreactive products were localized in the cytoplasm and/or nucleus of spinous and parakeratotic layers, but not in basal and keratinous layers. In addition, five out of nine papillomas stained positively for ADF, especially in koilocytotic cells. Eight out of 13 squamous cell carcinomas stained positively. Furthermore, ADF positive areas in oral epithelial lesions were included in the areas for protein bound SH-groups. Our results suggested that ADF may be a factor involved in the differentiation and proliferation of stratified squamous epithelium of the oral cavity.

Carcinoma, Squamous Cell↗
PubMed1991

The influence of noise exposure on endolymphatic hydrops. An experimental study.

The influence of noise exposure on endolymphatic hydrops was examined morphologically. Endolymphatic hydrops was produced experimentally in guinea pigs by means of endolymphatic sac obliteration. Approximately 2 months later, the animals were subjected to noise exposure for 2 h and, as a result, the following findings were obtained: Vascular and circulatory disturbances in the 3rd and 4th turns of cochlea, i.e., vasoconstriction-like changes in the upper coiled arterioles and capillaries in the stria vascularis, as well as blood cell sludge. In addition, the outer hair cells in Corti's organ at the same turns disappeared sporadically. No changes were observed in the opposite, control, ear of the same animal which was free from endolymphatic hydrops. On the basis of these results, it is argued that endolymphatic hydropic ears are highly vulnerable to noise exposure.

Animals↗
PubMed1991

Development of inner ear vessels. A scanning electron microscopic study.

The development of the inner ear vessels of guinea pigs were studied by SEM. Employing 32- to 55-gestational-day-old guinea pig embryos, corrosion casts of inner ear blood vessels were prepared using Mercox resin and then observed by scanning electron microscopy. Between the 35th and 40th gestational days, the vascular structure of the vestibule was sufficiently developed, but the capillary network in the wall of the cochlea remained immature. Thus, in the guinea pig, the development of the vestibular structure precedes the development of the cochlear vessels. Moreover, at both sites, the density of the embryonic blood vessels was high, and the vessels were believed to transport a large blood flow. From about the 40th day of gestation, the coiled vessels and the capillary network in the lateral wall of the cochlea underwent rapid development, and the vascular structure in both the vestibule and cochlea was nearly complete by the time of birth.

Animals↗
PubMed1991

Measurement of inner ear vessel diameters with casting method.

Under scanning electron microscopy we measured the vessel diameters of every part of the inner ear in rats and guinea pigs with casting method using Mercox resin. There were only few errors in measurement values in the same part of the same vessel with this method. The vessels of the stria vascularis were much larger in diameter than any other capillaries in the lateral wall of the cochlea in the rat and especially in the guinea pig. It is suggested that the velocity of the blood flow in the stria vascularis is slow and that the stria vascularis can retain much blood. The anterior vestibular artery (AVA) was larger in diameter than the posterior vestibular artery (PVA). The AVA supplies the large area in the vestibule whereas the PVA supplies the small area.

Animals↗
PubMed1991

Distribution of arteries from brain stem to inner ear around the internal auditory canal.

In the present work, casts of vessels surrounding the internal auditory canal of the guinea pig were subjected to scanning electron microscopic examination. Most casts were prepared by the resin-casting method using Mercox resin. The following results were obtained: 1) Individual variations and bilateral asymmetry were observed in the anterior inferior cerebellar artery (AICA), which branches off the basilar artery (BA); 2) Frequently a loop the AICA was found in the CP-angle and internal auditory canal; 3) The internal auditory artery (IAA) did not always originate in AICA but sometimes arose directly from BA; 4) In common cochlear artery and anterior vestibular artery, there were individual differences and asymmetric branching patterns on both sides; 5) We conclude that inner ear disease of vascular origin may be influenced by individual variations in the BA and its branches.

Animals↗
PubMed1991

Microvasculature of the tympanic membrane.

In order to investigate the blood flow of the tympanic membrane (TM) in various conditions, the microvasculature of the TM was observed by scanning electron microscope, using casting methods. Differences in vascular patterns between pars tensa and pars flaccida were observed, suggesting that vascular distribution in TM is closely concerned with the arrangement of radial fibers in the intermediate fibrous layer. Once inflammation was induced, changes in blood vessels quickly took place and most remarkably at the central zone of TM. The TM which closed earlier was found to leak resin at the edge of the perforation. It is proposed that an active blood flow to the perforation edge is necessary for a smooth closing.

Animals↗
PubMed1991

Microvascular structure of the larynx. A scanning electron microscopic study of microcorrosion casts.

In this study, scanning electron microscopic observations were made of the microvasculature of the larynx of guinea pigs, rabbits and humans. The results showed that 1) The epiglottis being the most abundant of all laryngeal structures in vascular plexus, with some of the vessels perforating cartilage; 2) Blood vessels of the vocal cord course along its long axis showing undulation; arteriovenous anastomoses was noted; 3) In the arytenoid, blood vessels were found to be irregularly coursing and tortuous, thereby facilitating the purpose of smooth movements of this structure.

Animals↗
PubMed1990

Role of ATL-derived factor (ADF) in the normal and abnormal cellular activation: involvement of dithiol related reduction.

HTLV-I transformed T cells not only express a large number of interleukin-2 receptors (IL-2R/p55(Tac], but also produce an IL-2R/Tac inducer named ATL-derived factor (ADF). We have cloned the ADF cDNA and found that ADF production in human lymphocytes can be enhanced by cellular activators such as mitogens or phorbol esters. Recombinant ADF produced by E. coli was shown to have growth-promoting activity in combination with interleukin-2 or suboptimal mitogenic stimuli on several lymphoid cells including human PBMCs, besides the originally reported IL-2R/Tac inducing activity. Homology analysis revealed an unexpected structural relationship between ADF and dithiol-reducing enzyme, thioredoxin, which had been characterized originally in prokaryotic system. Recombinant ADF also has a reducing activity, suggesting the presence of still unknown features of ADF action in vivo. The requirement of dithiol reduction in the biological activities of ADF, together with the possible involvement of ADF production in the normal and abnormal activation of human cells are discussed.

Amino Acid Sequence↗
PubMed1989

Mitogenicity and down-regulation of high-affinity interleukin 2 receptor by YTA-1 and YTA-2, monoclonal antibodies that recognize 75-kDa molecules on human large granular lymphocytes.

A large number of interleukin 2 receptors lacking the Tac epitope (IL-2R/p75) were found to be constitutively expressed on the human large granular lymphocyte/natural killer cell line YT, which bears inducible IL-2R/p55 associated with Tac antigen. Two anti-YT IgG1 monoclonal antibodies, YTA-1 and YTA-2, recognizing different epitopes of the same 75- to 80-kDa molecule, were established. The 75-kDa antigen recognized by these monoclonal antibodies was strongly expressed on the large granular lymphocytes of normal peripheral blood mononuclear cells and on various lymphoid cell lines bearing IL-2R/p75. The YTA-1 and YTA-2 antibodies were mitogenic and were different from other mitogenic monoclonal antibodies such as anti-T3 (CD3), anti-T11 (CD2), and KOLT-2 (CD28). Further, they down-regulated the high-affinity IL-2R of peripheral blood mononuclear cells within 24 hr in culture. The relationship between the YTA-1/2 antigen and the IL-2R system is discussed.

Antibodies, Monoclonal↗
PubMed1988

Noise-induced vasoconstriction in the cochlea.

Observation of the inner ear vessel using the casting method has the advantage of revealing the whole of the blood vessel in the one animal. This study was employed the blood vessel casting method and stylene cracking method to observe the morphological changes occurring in the inner ear vessel due to sound exposure. Results indicated vasoconstriction of the blood vessels of the cochlear lateral wall and spiral lamina due to sound exposure. Sludging of the blood cells was also recognized in these blood vessels. Such morphological changes were found to be reversible. The above findings thus imply that the cause of NITTS (Noise-Induced Temporary Threshold Shift) and NIPTS (Noise-Induced Permanent Threshold Shift) lies in impaired blood flow due to vasoconstriction of the inner ear capillary.

Animals↗
PubMed1988

IL-2 receptor and Fc epsilon R2 gene activation in lymphocyte transformation: possible roles of ATL-derived factor.

Lymphocyte transformation/activation is accompanied by the induction of a variety of the inducible receptors associated with the activation antigens. The p55 chain of the interleukin-2 receptor (IL-2R/p55) recognized by anti-Tac monoclonal antibody (mAb) is expressed on activated T and B cells as well as natural killer (NK) cells. IL-2R/p55(Tac) is constitutively expressed on T4(+) T cells transformed by human T-lymphotropic virus I (HTLV-I), which is a causative agent for adult T-cell leukemia (ATL). Low affinity Fc receptor for IgE (Fc epsilon R2/CD23) is another inducible receptor binding IgE and is expressed on various hematopoietic cell types. While the physiological expression of Fc epsilon R2 and its soluble form (IgE Binding Factor; IgE BF) is variably regulated by cytokines and IgE, there is a constitutive expression of Fc epsilon R2 on Epstein-Barr virus (EBV) transformed B cell lines and some of HTLV-I (+) T cell lines. ATL-derived factor (ADF) has been characterized as an IL-2R/p55(Tac) inducing factor derived from HTLV-I(+) T cell lines. Purification of ADF protein and the cDNA cloning proved that ADF is closely related to the autocrine growth factor produced by an EBV(+) B cell line 3B6 (H. Wakasugi and T. Tursz) and belonging to the family of thiol reducing co-enzyme thioredoxin which is involved in many biological reactions. Recombinant ADF produced by COS cells and E. coli showed both IL-2R inducing and reducing activities. We will discuss the biological roles of ADF in viral and normal lymphocyte activation and transformation in relation to the receptor gene activation.

Amino Acid Sequence↗