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K Shibata

Publications and source records attributed to K Shibata.

At least 19 recordsLinked to original sources
PubMed1992

Identification of a cis-acting element that enhances the pigment cell-specific expression of the human tyrosinase gene.

To identify the cis-acting element that is responsible for the pigment cell-specific expression of the human tyrosinase gene, we analyzed the promoter activity of its 5'-flanking region by transient expression assays. The fusion genes were constructed by inserting the 5'-flanking region of the human tyrosinase gene upstream from the firefly luciferase gene and were introduced into human melanoma cells and HeLa cells. We thus found the element, located between 2.7 and 1.8 kilobase pairs upstream from the transcription initiation site, that enhances the transient expression of the luciferase reporter gene in melanoma cells, but not in HeLa cells, the tyrosinase gene expression of which is not detectable. Using the fusion genes containing putative enhancer elements under the control of the heterologous simian virus 40 promoter, we identified the pigment cell-specific enhancer of approximately 200 base pairs (bp) between -2.0 and -1.8 kilobase pairs and localized the core sequence to a 39-bp region. This 39-bp core element was then confirmed to direct the melanoma cell-specific expression of the reporter gene under the tyrosinase gene promoter. We thus propose that this core element is responsible for the pigment cell-specific expression of the human tyrosinase gene.

Animals↗
PubMed1992

The location of the arginine-specific carboxypeptidase in the membrane of Mycoplasma salivarium and its physiological functions.

A non-penetrating probe, 2,4,6-trinitrobenzenesulfonate, inhibited the activity of the carboxypeptidase purified from the cell membranes of Mycoplasma salivarium and the same enzymatic activity of intact Mycoplasma cells as well. Growth of the organism in medium containing benzoylglycyl-L-arginine resulted in a higher pH and higher turbidity than growth in the same medium without this supplement. It was concluded that the enzyme existed in the outer surface of the membrane of the cells and probably functioned to supply the organism with arginine as an energy source.

Arginine↗
PubMed1992

Downstream region of the human tyrosinase-related protein gene enhances its promoter activity.

We have cloned and sequenced the human genomic DNA segments encoding the 5'-flanking region and the first two exons of the tyrosinase-related protein (TRP) gene, a pigment cell-specific gene. Functional analysis of its promoter suggests that the downstream region of the TRP gene, including the first intron, enhances the transient expression of the luciferase gene under control of the TRP gene promoter about 16- to 20-fold. This enhancer-like activity is detected not only in melanoma cells but also in HeLa cells whose TRP gene expression is assumed to be repressed. We suggest a possibility that the downstream region is not sufficient to confer pigment cell-specific expression, but is required for efficient transcription of the TRP gene in pigment cells.

Animals↗
PubMed1992

Vesicular stomatitis virus antigenic octapeptide N52-59 is anchored into the groove of the H-2Kb molecule by the side chains of three amino acids and the main-chain atoms of the amino terminus.

This study describes an analysis of the interaction of individual amino acid residues of the vesicular stomatitis virus (VSV) nucleocapsid antigenic octapeptide (N52-59; Arg-Gly-Tyr-Val-Tyr-Gln-Gly-Leu) with the H-2Kb molecule and T-cell receptors (TCRs). Tyr-3, Tyr-5, and Leu-8 were the positions in the peptide found to be H-2Kb contact residues by analyzing single alanine-substituted peptides in a competition assay with a Kb-restricted antigenic nonapeptide of Sendai virus. Arg-1, Gly-2, Val-4, Gln-6, and Gly-7 of the peptide were identified as putative TCR contact residues by testing the peptide analogs for their capacity to sensitize targets for VSV-specific cytolytic T-lymphocyte clones. The octamer N52-59 was the optimal length of the peptide required for binding to Kb. This peptide length requirement and the finding of an irregular interspersing of major histocompatibility complex and TCR contact residues are most consistent with the conclusion that the peptide is in an extended conformation in the antigen binding groove. Furthermore, data on binding of truncated peptides show that, although the Arg-1 side chain has been assigned as a TCR contact residue, the main-chain atoms of the N-terminal amino group are most likely involved in interacting with the major histocompatibility complex molecule. A panel of H-2Kb point mutants was constructed to explore the effect of altered amino acid residues on the binding of N52-59. Mutants with amino acid substitutions along the floor of the groove all bound the VSV peptide but modulated its interaction with Kb, apparently causing subtle changes in the spatial arrangement of some specific TCR contact residues in the peptide.

Amino Acid Sequence↗
PubMed1992

Postoperative pyothorax.

Twenty-five cases of pyothorax occurred in a series of 1281 thoracotomies. Almost all cases of pyothorax without bronchopleural fistula were successfully treated by closed drainage and irrigation alone. On the other hand, patients with pyothorax and fistula who were treated only with closed drainage almost all had a poor outcome. When pyothorax with fistula was treated by closed drainage and irrigation followed by further procedures such as open window thoracostomy, muscle plombage and/or omentopexy, treatment was successful. It is concluded that pyothorax without fistula may be cured by closed drainage and irrigation alone, but that pyothorax with fistula requires operative intervention such as open window thoracostomy or omental flap as soon as possible.

Adolescent↗
PubMed1992

Decreased circulation time in the upper limb reduces the lag time of the finger pulse oximeter response.

To observe the influence of circulatory changes on the lag time of the pulse oximeter response, eight healthy patients scheduled for hand surgery were studied. After breath holding, the patients took a breath of oxygen and the time to an increase in SpO2 was measured before and after axillary brachial plexus block. It was found that the lag time with finger probe decreased from 28.6 +/- 7.1 sec to 15.8 +/- 1.1 sec (mean +/- SD) following brachial block (P less than 0.01). There was no change in arterial blood pressure. The results suggest that the lag time of the finger pulse oximeter response is primarily determined by blood flow.

Adult↗
PubMed1992

Preprotachykinin gene expression in the human basal ganglia: characterization of mRNAs and pre-mRNAs produced by alternate RNA splicing.

The nature and distribution of preprotachykinin (PPT, i.e. substance P/neurokinin A-encoding) gene expression in human basal ganglia was determined. Northern blot analysis visualized a single band of approximately 1300 bases, confirming the postmortem stability of PPT mRNA. Gross anatomical analysis indicated that PPT gene expression was relatively evenly distributed throughout the human caudate and putamen, but absent in the globus pallidus and substantia nigra. Nuclease protection analysis of these tissues established that human PPT mRNA consisted of approximately 80-85% beta-PPT (exon 1-7 derived) mRNA and 15-20% gamma-PPT (minus exon 4), with no alpha-PPT (minus exon 6) mRNA detected; these data contrast with the proportions of PPT mRNAs seen in non-human species. The incompletely spliced PPT RNA species detected in basal ganglia accounted for approximately 8% of total human PPT RNA and suggested a fixed order of exon splicing. Since various PPT mRNAs encode different combinations of tachykinin peptides with distinct biological activities, the markedly different proportions of PPT mRNAs seen in human basal ganglia compared to non-human tissues may be of physiological significance.

Animals↗
PubMed1992

Immunoelectronmicroscopic differentiation of linear IgA bullous dermatosis of adults with coexistence of IgA and IgG deposition from bullous pemphigoid.

BACKGROUND: The differentiation between linear IgA bullous dermatosis (LABD) and bullous pemphigoid (BP) is sometimes difficult in patients who have both IgA and IgG deposition in a linear pattern at the basement membrane zone. OBJECTIVE: We address whether two cases of acquired subepidermal blistering disease with coexistence of IgA and IgG deposition in a linear pattern at the basement membrane zone are LABD or BP. METHODS: The two cases were investigated by immunoelectron microscopy and compared with two typical cases of LABD. RESULTS: In both cases, the deposition of IgA and IgG was ultrastructurally localized below the lamina densa in close association with anchoring fibrils, as was seen in two cases of typical LABD. CONCLUSION: These findings indicate that our two cases of acquired blistering disease with co-existence of IgA and IgG deposition are LABD, rather than BP.

Aged↗
PubMed1992

Immunoglobulin G Fc fragment-binding proteins in Mycoplasma salivarium cells.

Cell proteins of Mycoplasma salivarium were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to membranes, then examined for reactivity with human IgG molecules, the Fc fragment of human IgG, and concanavalin A (ConA). Multiple protein bands bound IgG, and most of them also bound ConA. One (corresponding to a molecular mass of 90 kDa) of the IgG- and ConA-binding bands intensely interacted with the Fc fragment of IgG. The reactivity of proteins eluted from the band with the Fc fragment, tested by dot-blotting and ELISA, was inhibited (90%) by pre-incubation with IgG and to a lesser extent (50%), with IgM. Thus, M. salivarium contained a cellular protein with a molecular mass of 90 kDa, that bound the Fc fragment of human IgG.

Bacterial Proteins↗
PubMed1992

First autoclave-sterilized platelet-additive solution containing glucose with a physiological pH for the preparation of plasma-poor platelet concentrates.

The glucose-free platelet-additive solution (termed AR solution), developed by Adams and Rock [Transfusion 1988;28:217-220], was modified by adding glucose as an energy substrate for platelets and maltose to prevent platelet lysis and by replacing sodium gluconate with sodium phosphate for better pH maintenance. The new platelet-additive solution (termed Seto solution) contained 90 mM NaCl, 5 mM KCl, 3 mM MgCl2, 17 mM tri-sodium citrate, 4.9 mM NaH2PO4, 20.1 mM Na2HPO4, 23 mM sodium acetate, 28.8 mM maltose, and 23.5 mM glucose with a pH of 7.4. The solution was sterilized by autoclaving in plastic bags in nitrogen to prevent glucose caramelization at high pH. Plasma-poor platelet concentrates prepared by adding Seto solution to the pelleted platelet buttons were stored in a LE-2 polyolefin bag at 22 degrees C with constant agitation for 5 days. The platelets suspended in Seto solution maintained oxygen consumption at a rate of 1.1 nmol/min/10(9) platelets after 5-day storage, with glucose consumption and lactate production rates of 0.5 +/- 0.2 and 1.2 +/- 0.2 nmol/min/10(9) platelets, respectively. This resulted in a final mean pH of 7.0. Those suspended in AR solution ceased glycolysis within 3 days because residual plasma glucose had been consumed. This was associated with decreases in percent hypotonic shock response and aggregation induced by adenosine diphosphate and collagen. Lactate dehydrogenase discharge in AR solution was 5 and 8 times higher at day 3 and day 5, respectively, than that of Seto solution. Morphologically, there were no ballooned platelets after storage in Seto solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗
PubMed1992

Identification of mutations in the pigment cell-specific gene located at the brown locus in mouse.

The pigment cell-specific gene, located at the brown (b)-locus in mouse, encodes the protein that determines the type of melanin synthesized. This protein is known as tyrosinase-related protein, but here we tentatively term it b-locus protein to avoid confusions with the related sequence cross-hybridizing to the tyrosinase gene. In order to identify the mutation at the b-locus, we have cloned and characterized the b-locus protein gene of BALB/c mouse (b/b, c/c). The gene is about 18 kb long and organized into 8 exons and 7 introns. Sequence analysis of the b-locus protein gene reveals four base changes within the protein-coding regions: two missense mutations and two silent mutations. Two missense mutations result in the Cys to Tyr substitution at position 86 (codon 110) and the Arg to His substitution at position 302 (codon 326) of a b-locus protein molecule. Using allele-specific amplification, we confirmed that these missense mutations are actually present in the genomic DNA of two b-mutant strains examined, BALB/c and DBA/2 (b/b, C/C) mice, suggesting that these mutations are specific for the mutant mice at the b-locus. Moreover, we are able to show that the b-locus protein containing Tyr 86 is not reactive with the anti-b-locus protein monoclonal antibody, TMH-1, in transient expression assays.

Amino Acid Sequence↗
PubMed1992

Establishment of a folliculo-stellate-like cell line from a murine thyrotropic pituitary tumor.

An isologously transplantable mouse thyrotropic pituitary tumor (TtTb) that had been induced by radiothyroidectomy was found to form lobules composed of parenchymal glandular cell elements. The surfaces of these lobules were covered by stellate cells bearing long processes that gave a strong immunopositive reaction with a specific antiserum against glial fibrillary acidic protein (GFAP). GFAP was also positive in pituitary folliculo-stellate cells (FS cells). Since in the anterior pituitary gland, no other cellular component showing positive staining with anti-GFAP antibody was observed, it seems probable that the GFAP-positive cells in the thyrotropic tumor are related to the FS cells in the anterior pituitary. Upon cultivation of the thyrotropic tumor, cells with long processes appeared. These cells showed strong staining for GFAP and were dependent on basic fibroblast growth factor for cell growth. By repeated passage, the GFAP-positive cells became a stably growing immortal cell line, which was tentatively named TtT/GF. Since the characteristics of TtT/GF were similar to those of FS cells in the anterior pituitary, i.e. the presence of many lysosomes and numerous intermediate filaments in the cytoplasm, phagocytic activity, follicle formation, and GFAP and S-100 protein positivity, we suggest that TtT/GF cells are derived from pituitary FS cells.

Animals↗
PubMed1992

Antiandrogen. I. 2-azapregnane and 2-oxapregnane steroids.

2-Azachlormadinone acetate (5a, 17-acetoxy-6-chloro-2-azapregna-4,6-diene- 3,20-dione), 2-oxachlormadinone acetate (6, 17-acetoxy-6-chloro-2-oxapregna-4,6-diene-3,20-dione) and the derivatives were prepared as potential antiandrogenic agents. Biological evaluation showed that 5a and 6 had a potent antiandrogenic activity when tested in the castrated male rat.

Androgen Antagonists↗
PubMed1992

Renal microangiography and correlated histopathological observation of cows with nephropathy.

Seven Holstein-Friesian cows showing chronic nephropathy were studied by renal microangiography and its correlated histopathology. In cases of pyelonephritis associated with severe pathological lesions such as thickening of arterial walls, narrowing of the arterial and arteriolar lumen, and interstitial inflammation and abscess formation, patchy loss of the peritubular capillary plexus from the cortex to the medulla was clearly demonstrated by microangiography. Interlobular arteries were tortuous and attenuated or truncated. Opacification in the vasa rectae and interstitial capillaries was increased. Extensive non-perfused regions could be detected in the cortex. In cases of mild interstitial nephritis and moderate pyelonephritis, microangiography showed focal changes in the renal vasculature. Microangiography is thus shown to clearly demonstrate changes in the renal vasculature corresponding to the severity of the histopathological lesions.

Angiography↗
PubMed1992

Identification of effective component from a traditional herbal medicine and the inhibitory effects on experimental glomerular lesion in mice.

Effective constituents for renal disease were partially purified from a herbal prescription. The efficacy on renal diseases was examined using an experimental model system of glomerular lesion in mice induced by Agkistrodon acutus venom (Ac1-P). The extract of boiling water of the herbal prescription (P-3) was first fractionated by ether into an acidic fraction and a mixture of basic and neutral fractions. The acidic fraction was proved to be more effective and then further examined by thin layer chromatography and spectrophotometry. One of the main components was confirmed to be caffeic acid which had inhibitory effect on renal failure in mice by Ac1-P. This effect was considered to be caused by caffeic acid inhibiting the proteolytic enzyme activity of Ac1-P. Caffeic acid should thus have prophylactic or inhibitory effect on glomerular disease in which proteolytic enzymes may have pathogenic roles.

Animals↗
PubMed1992

Hemichorea associated with ipsilateral chronic subdural hematoma--case report.

Left-sided hemichorea developed suddenly in a 73-year-old male. Computed tomography revealed a left subdural hematoma (SDH) and infarction in the right corona radiata and temporo-occipital region. Hemichorea subsided completely after removal of the SDH. Postoperative single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime revealed a global low-perfusion area in the right cerebral hemisphere. Right carotid angiography demonstrated severe stenosis of the trunk of the right middle cerebral artery. The cerebral blood flow in the right cerebral hemisphere had probably already decreased to nearly the critical level and was reduced further by the left SDH, inducing the left-sided hemichorea due to dysfunction of the right cerebral hemisphere. This case shows that when hemichorea ipsilateral to a SDH is present, it is important to ascertain whether there is a pre-existing ischemic lesion in the contralateral cerebral hemisphere, particularly in the basal ganglia, thalamus, or corona radiata.

Aged↗