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T Nishida

Publications and source records attributed to T Nishida.

At least 451 records · Page 25Linked to original sources
PubMed1991

Nucleotide sequence of pnl gene from Erwinia carotovora Er.

The nucleotide sequence of pnl gene encoding pectin lyase (PNL; EC4.2.2.10)from Erwinia carotovora Er was determined. The structural gene of pnl consisted of 942 base pairs. An open reading frame that could encode a 33,700 dalton polypeptide consisting 314 amino acids was assigned. The molecular size of the polypeptide predicted from the amino acid composition was close to the value of PNL determined in E.carotovora Er. The nucleotide sequence of the 5'-flanking region showed the presence of the consensus sequence of ribosome binding site, Pribnow box and the RNA polymerase recognition site in E.carotovora and Escherichia coli. Between the presumed Pribnow box and the ribosome binding site, two pairs of inverted repeats were found. By comparing the predicted amino acid sequences of pnl, several reported bacterial pectate lyases and Aspergillus niger pectin lyase, short regions of homology were found despite the different substrate specificities of these enzymes.

Amino Acid Sequence↗
PubMed1991

Sequencing and cloning of the cDNA of guinea pig eosinophil major basic protein.

Major basic protein (MBP) purified from guinea pig eosinophils elicited histamine release from rat peritoneal mast cells at concentrations higher than 3 micrograms/ml both in the presence and in the absence of extracellular Ca2+. After reverse-phase high-performance liquid chromatography, it was revealed that MBP was composed of two different proteins with quite similar molecular weights and pI values, although the amino acid compositions were slightly different. The partial amino acid sequence of one of these MBPs was determined and the primers for the polymerase chain reaction (PCR) were synthesized according to the partial amino acid sequence. Using these primers and the cDNAs obtained from guinea pig eosinophils, the PCR was carried out in order to synthesize the hybridization probe of MBP for screening the cDNA library. After screening with 8 x 10(5) clones, a positive clone, which encoded a full length of pre-proMBP, was obtained. According to the sequencing data of this clone, it was revealed that pre-proMBP was composed of 3 domains; signal peptide, acidic domain and mature MBP. The predicted pI value of mature MBP was 11.7, though that of proMBP was 7.8. The homology in the amino acid sequence between guinea pig proMBP and human proMBP was 49.4%, while guinea pig mature MBP was more homologous (58%) to human mature MBP.

Amino Acid Sequence↗
PubMed1991

Effect of tunicamycin, an inhibitor of protein glycosylation, on testicular cord organization in fetal mouse gonadal explants in vitro.

The effect of tunicamycin (TM) on testicular cord organization in the fetal mouse was examined in vitro at light and electron microscopic levels, with special reference to the glycoprotein functions during Sertoli cell differentiation. In testicular explants treated with TM, testicular cord organization was inhibited. TM treatment affected basal lamina formation by Sertoli cells, resulting in a discontinuous basal lamina or none at all in certain areas. The disorganized Sertoli cells were amorphous in shape, exhibited poor epithelial polarity, and were irregularly arranged in the testicular parenchyma. Extracellular matrix and collagen fibers were often observed in the intercellular spaces between the disorganized Sertoli cells. Lectin histochemical observation revealed that the number of wheat germ agglutinin binding sites on the plasma membrane and basal lamina of disorganized Sertoli cells was significantly decreased by TM treatment. However, junctions were normally observed in the plasma membrane between disorganized Sertoli cells. Leydig cells showed a normal differentiation in the testicular parenchyma in the presence of TM. These observations suggest that basal lamina formation of Sertoli cells and/or the expression of their cell surface glycoconjugates may be crucial for the establishment of Sertoli cell polarity and/or the Sertoli-Sertoli cell interactions required for proper testicular cord formation. Sertoli cell organization into testicular cords and Leydig cell differentiation may be controlled by different regulatory mechanisms.

Animals↗
PubMed1991

Expression of fibronectin receptor (integrin) in the uterus of rats in relation to the estrous cycle.

The expression and localization of fibronectin receptor (integrin), fibronectin, laminin and collagen type IV in the endometrium of the rat uterus during each period of the estrous cycle were investigated by immunofluorescent microscopy. Fibronectin receptor was observed at the epithelial cells of the endometrium and at vascular endothelial cells. At proestrus, when epithelial cells actively migrate, fibronectin receptor was observed at the basal and lateral epithelial cell surfaces. During estrus, fibronectin receptor had begun to disappear, little fibronectin receptor was observed at metestrus or diestrus. No prominent changes in the localization of fibronectin (seen at the vascular endothelial cells and in the stroma) or of laminin and collagen type IV (seen at the muscles and at the basement membranes of the epithelial and vascular endothelial cells) were observed in relation to the estrous cycle. Thus, uterine epithelial cells, like epithelial cells of the healing cornea, increase their expression of fibronectin receptor during active migration, probably facilitating their attachment to stromal fibronectin. This fibronectin-fibronectin receptor mechanism may underlie epithelial repair, whether the defect results from physiological processes or from an insult.

Animals↗
PubMed1991

De novo interstitial deletion of 4q[46,XX,del(4)(q27q28.2)] with intact blood group-MN locus, confining its locus to 4q28.2-4q31.1.

We report a malformed female infant with de novo interstitial deletion of 4q[46,XX,del(4)(q27q28.2)]. The MN blood type analysis of the family members showed that the patient had an intact blood group-MN locus. The locus of the gene responsible for the MN antigen activity is confined to a 4q28.2-4q31.1 segment on the basis of the result of this patient and the previous mapping data.

Abnormalities, Multiple↗
PubMed1991

Hyaluronan stimulates corneal epithelial migration.

Hyaluronan (hyaluronic acid), well-known for its viscoelastic properties, is also recognized as a biological signal to cells. Using organ cultures of the rabbit cornea, we investigated the effects of hyaluronan on the migration of corneal epithelium. The addition of hyaluronan to the culture medium increased the length of the path of the corneal epithelial layer in a dose-dependent fashion. Other glycosaminoglycans (chondroitin, chondroitin sulphate, keratan sulphate and heparan sulphate) were also tried, but only hyaluronan exhibited a stimulatory effect on corneal epithelial migration. The effects of hyaluronan and fibronectin or epidermal growth factor (EGF) were additive; the addition of antisera against fibronectin or against EGF did not alter the stimulatory effect of hyaluronan. These results demonstrate that hyaluronan stimulates corneal epithelial migration by mechanism(s) different from those of fibronectin and EGF.

Animals↗
PubMed1991

Deep-etch visualization of the Sertoli cell (blood-testis) barrier in the boar.

The Sertoli cell (blood-testis) barrier in the boar was visualized by the freeze-fracture, deep-etch, rotary-replication technique. Three kinds of cross-bridging structures were clearly recognized in the following three ectoplasmic specialization (ES) regions; (1) cross-bridges in the intercellular space between adjacent Sertoli cell membranes; (2) cross-bridges in the space between the Sertoli cell membrane and microfilament bundles; and (3) cross-bridges in the space between microfilament bundles and subsurface cisternae. Results from immunolocalization, vinculin and alpha-actinin were recognized in the Sertoli cell barrier. Our findings show that these structural elements of the Sertoli cell barrier are held together by these cross-bridging structures, and provide important morphological evidence that implicates the ES in the dynamic function of the microfilament bundles of the Sertoli cell barrier.

Actin Cytoskeleton↗
PubMed1991

Case report: diagnosis of cavo-portal shunt in inferior vena cava obstruction: comparison between venography and dynamic scintigraphy.

A cavo-portal shunt is a rare complication of inferior vena cava obstruction. A patient is described who had complete obstruction of the inferior vena cava (IVC) due to extension of tumour thrombus from a left renal cell carcinoma. Venocavography clearly showed many collateral veins but not a cavo-portal shunt. Dynamic scintigraphy, however, distinctively showed a draining vein and subsequent homogeneous radionuclide uptake of the liver, which indicates a cavo-portal shunt.

Carcinoma, Renal Cell↗
PubMed1991

Renaturation, purification, and characterization of human truncated macrophage colony-stimulating factor expressed in Escherichia coli.

A human truncated macrophage colony-stimulating factor (M-CSF) encoding the amino acid residues from 3 to 153 of the native M-CSF was expressed by using a two-cistron expression system in Escherichia coli. The truncated M-CSF found in inclusion bodies was renatured and had CSF activity. Purification, which included a QAE-ZeTa preparative cartridge concentration step followed sequentially by HPLC on TSK-gel Phenyl-5PW and TSK-gel DEAE-5PW columns, gave an overall yield of 63.8%. The purified truncated M-CSF had a specific activity of 4 x 10(7) units/mg of protein. Peptide mapping of a lysylendopeptidase digest by reversed-phase HPLC confirmed the amino acid sequence predicted from the cDNA sequence. SDS-PAGE of the purified truncated M-CSF gave a single band at 17 kDa under reducing conditions and at 32 kDa under non-reducing conditions. Activated Thiol-Sepharose 6B column chromatography and other experiments failed to detect any free cysteine residue in spite of the existence of 7 cysteine residues in the truncated M-CSF subunit. These results indicate that it is a dimeric structure linked by one or more intermolecular disulfide bonds.

Amino Acid Sequence↗
PubMed1991

Long-term storage of endocytosed latex beads in keratocytes in vivo.

Endocytosis by keratocytes (corneal fibroblasts) is an important part of the host defense system. To investigate the long-term fate of endocytosed materials, we injected polystyrene latex beads into the corneal stroma of four rabbits. The corneal stroma was observed under a transmission electron microscope 4 and 800 days after the injection. After 4 days, the beads were found not only between the collagen fibers of the stroma, but also in some keratocytes. After 800 days, no extracellular beads were seen, but endocytosed beads remained, surrounded by limiting membranes, in the cytoplasm of keratocytes. These observations demonstrate that keratocytes endocytose latex beads and store them for a long time, isolating these foreign materials from the corneal stroma. These observations suggest that keratocytes, like some other fibroblasts perform a noninflammatory and nonimmunological defense function.

Animals↗
PubMed1991

Ischemic myocardial mitochondrial function and ultrastructural change--influence of regional myocardial blood flow.

Myocardial blood flow (MBF), tissue ATP content, mitochondrial respiratory function and mitochondrial ultrastructure were examined in 62 adult mongrel dogs weighing 6-14 kg in which acute myocardial ischemia had been produced under anesthesia. The left anterior descending coronary artery was dissected free for ligation before the first diagonal branch. MBF was measured before coronary ligation and 60 min following ligation. Then, samples of myocardium were taken and subjected to tissue ATP content assay, mitochondrial respiratory function measurement respiratory control index (RCI) and rate of oxygen consumption in state III (QO2III); and electron microscopic examination. Mitochondrial morphologic injury was evaluated quantitatively according to Schaper's criteria. MBF was significantly correlated with tissue ATP content, mitochondrial respiratory function and mitochondrial ultrastructural change. When MBF was less than 20 ml/min/100g, tissue ATP content (1.86 +/- 1.21 mumol/g wet weight) and mitochondrial respiratory function (RCI 2.51 +/- 0.59) were significantly lower than in the non-ischemic area (ATP 4.52 +/- 1.11, RCI 3.82 +/- 0.37), and mitochondrial ultrastructural injury had deteriorated significantly at an MBF below 40 ml/min/100 g. In conclusion, our findings show that when MBF is reduced, mitochondrial ultrastructural changes precede the depression in mitochondrial oxidative phosphorylation.

Adenosine Triphosphate↗
PubMed1991

Histochemical localization of inhibin and activin alpha, beta A and beta B subunits in rat gonads.

The localization of alpha, beta A and beta B subunits of inhibin/activin polypeptides was studied in the ovary and testis of sexually mature, immature, and embryonic rats. Specific staining with these three subunits was also evident in the oocytes from embryonic to mature female rats. This result suggests that inhibin- and activin-like substances may be produced in the oocytes and these substances may play a role in the oocyte growth and differentiation. Judging from the intensity of immunoreaction in mature female rats, the three subunits should be produced more abundantly in luteal cells than in the granulosa cells. Immunoreactive alpha, beta A and beta B subunits were observed in the cummulus oophorous in the morning (11:00), but not in the evening (23:00) on proestrus. The results are in well agreement with the previous report that inhibin alpha and beta A subunit mRNA signals decline on proestrus evening. It is supposed that the cyclic change may be related with physiological phenomena prior to the ovulation, such as primary gonadotropin surges, loss of cummulus-oocyte gap junctions, or germinal vesicle breakdown. In both germ cells and Sertoli cells of the testis, alpha, beta A and beta B subunits were more abundant in the embryonic rat than in the mature rat. Although clear reactions with beta A and beta B subunits were detected in Leydig cells, alpha subunit was not detectable in the cells throughout the developmental stages examined.

Activins↗
PubMed1991

Morphological studies on the vascular architecture in the boar spermatic cord.

The morphological features of the testicular artery and the pampiniform plexus in the boar spermatic cord were evaluated by light microscopy, corrosion cast technique combined with scanning electron microscopy and by transmission electron microscopy. The testicular veins could be subdivided into 4 types according to their perivascular elements and their location to the testicular artery. Type I vein consisted of large veins and gave rise to type II and III veins. Type II vein was composed of a single layer of veins and ran along the testicular artery, while type III vein consisted of several layers of veins and was located between type II veins. Type IV vein, which was regarded as a venous portal system, was composed of small muscular and pericytic venules and was located in the tunica adventitia of type II vein and the testicular artery. Occasionally, type IV vein penetrated deep into the tunica media of the testicular artery, accompanied by a fenestrated endothelium in its thin portion. The direct arterio-venous anastomosis between the pampiniform plexus and the testicular artery was not found. Type IV vein was considered to be the most important vessel in reducing the capacity of the barrier between the testicular artery and the veins (type II and III). It is, therefore, suggested that type IV venous network may play a role in transferring the substances between the artery and the veins.

Animals↗
PubMed1991

Analysis of various antigens in golden hamster testis by monoclonal antibodies.

A total of 38 hybridomas producing monoclonal antibodies (mAbs) was established by immunizing BALB/c mice with extracts of the golden hamster testis. Six mAbs stained the acrosome of developing spermatids by immunofluorescence. Two mAbs (1A11 and 4D8) reacted with spermatid components other than acrosome. The mAbs 1C9 and 4D3 recognized a 103 kilodalton (kDa) protein on immunoblots, and were reactive to spermatocytes and early spermatids, but not to late spermatids and spermatozoa. This finding suggests that the protein functions for meiosis or early spermiogenesis. Four mAbs (3G2, 2E5, 2G3, and 3F10) stained all stages of spermatogenic cells. The remaining 24 mAbs showed a positive reaction to the basement membrane of the seminiferous tubule. Two of them, 3D6 and 3E5, recognized approximately 150 kDa major proteins, indicating that the antigen is an extracellular matrix.

Acrosome↗
PubMed1991

Distribution pattern of pudendal nerve plexus for the phallus retractor muscles in the cock.

Two paired retractor muscles, m. retractor phalli cranialis (MRPCr) and m. retractor phalli caudalis (MRPCa) exist as the intrinsic cloacal muscles of the chicken. Pudendal plexus was formed by the ventral rami of roots 30-34. Pudendal nerve (PN) and the intermediated caudal nerve (ICN) were composed of twigs from roots 30-33 and roots 30-34, respectively. Two or three rootlets participated in the PN; its third one originated from the root 33 which is the first root of caudal trunk in pudendal plexus. The non-striated MRPCr was innervated by the PN, whereas the striated MRPCa by the ICN.

Animals↗
PubMed1991

A sequential immunosuppressive treatment with mizoribin (Bredinin) plus cyclosporin A on the subrenal capsule assay.

To minimize immunological interferences on the subrenal capsule (SRC) assay, a new immunosuppressor, mizoribin (MZB: Bredinin) alone or combined with cyclosporin A (ScA) was evaluated by an experimental SRC assay system using a rat ovarian cancer tissue. Daily applications of MZB (200 mg/kg) for 7 days following the xenograft of cancer tissue were insufficient to suppress immunological reactions of the recipient mice, and all the grafted cancer tissues were rejected. Although CsA monotreatment (60 mg/kg of CsA given daily for 7 days) successfully suppressed the host immune reaction, enhanced toxicities of CsA in combination with anticancer agents caused high lethal rate of host mice during the experimental chemotherapy. Sequential use of CsA on day 0 to day 2 followed by MZB on day 3, 5 and 7 brought the most favorable results with minimal host reactions and toxicities. An anticancer screening test using the modified SRCA accurately reflected the results of experimental chemotherapy against the rat ovarian cancer. The immunosuppressive treatment which minimizes immunological interferences with SRC assay chemoscreening test.

Animals↗