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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 775 records · Page 43Linked to original sources

Functional down-regulation of beta1 and beta2 integrins of lamina propria lymphocytes (LPL) and tumor-infiltrating lymphocytes (TIL) in colorectal cancer patients.

Integrins play an important role in various lymphocyte functions. In this study, we isolated lamina propria lymphocytes (LPL) and tumor-infiltrating lymphocytes (TIL) from normal and malignant tissues in patients with colorectal cancer, and examined the expression of beta1 and beta2 integrins on these lymphocytes quantitatively with two-color flow cytometry. Both LPL and TIL expressed a lower level of common beta1 chain (CD29) in CD4 and CD8 subpopulations than did peripheral blood lymphocytes (PBL). Among the associated alpha chains, the expression levels of alpha1 (CD49a) and alpha2 (CD49b) were slightly higher, whereas those of alpha4 (CD49d) and alpha6 (CD49f) were markedly reduced in LPL and TIL. No significant differences were observed in expressions of any alpha1 integrin chains between these two lymphocytes populations. Similarly, both alphaL (CD11a) and beta2 (CD18) were down-regulated in TIL and LPL with CD8+ cytotoxic phenotype, but not in those with CD4+ phenotype. CD8+ TIL expressed a slightly but significantly higher level of alphaLbeta2 than did CD8+ LPL. CD8+ LPL and CD8+ TIL consistently showed significantly decreased binding to purified ICAM-1, VCAM-1 and HT29 colon cancer cells as compared with CD8+ PBL. Although CD8+ TIL showed a slightly higher level of adhesion to these substrates than did CD8+ LPL, the level was much lower than that in PBL. The expression pattern and functional down-regulation of these integrins may be one of the reasons why TIL cannot eradicate the cancer cells in colorectal cancer.

Adenocarcinoma↗

Impairment of cold-induced increase in thyroxine 5'-deiodinase activity in mouse brown adipose tissue by the intracerebroventricular administration of bombesin.

Effects of bombesin on brown adipose tissue (BAT) thyroxine (T4) 5'-deiodinase (5'D) activity and rectal temperature were examined in male mice. Immediately following an intracerebroventricular (ICV) or intravenous (IV) injection of bombesin (0.1-100 ng/animal) or vehicle (20 mM bacitracin dissolved in 0.9% saline), the mice were placed in a room at 4 degrees C or 22 degrees C for 30, 60, 120 or 240 min. The ICV injection of bombesin dose-dependently lessened cold-induced increase in BAT 5'D activity and increased hypothermia determined at 120 min of cold exposure, whereas the IV injection of bombesin was without effect. Bombesin (ICV)-induced hypothermia preceded the inhibition of BAT 5'D activity by at least 30 min at 4 degrees C. BAT 5'D activity was not affected by ICV injection of bombesin in mice kept at 22 degrees C, although the rectal temperature was significantly decreased. Bombesin thus appears to prevent cold-induced increase in T4 5'D activity in mouse BAT by its central effect. Bombesin-induced excessive hypothermia itself and/or the decrease in sympathetic tone of BAT by bombesin might decrease cold-induced increase in BAT 5'D activity.

Adipose Tissue, Brown↗

Perinatal intracranial hemorrhage due to severe neonatal alloimmune thrombocytopenic purpura (NAITP) associated with anti-Yukb (HPA-4a) antibodies.

Neonatal alloimmune thrombocytopenic purpura (NAITP) is one of the causes of thrombocytopenia in the newborn period. The thrombocytopenia is caused by maternal transplacental antiplatelet alloantibodies. We report a case of NAITP in a newborn infant having subarachnoid hemorrhage. Examination of platelet antibodies revealed anti-Yukb, that is, human platelet antigen (HPA)-4a incompatibility. Cranial ultrasound and brain magnetic resonance imaging revealed subarachnoid hemorrhage in the temporal region inferior to the cephalohematoma. The lesion seemed to have been sustained during delivery. The patient was treated with high-dose gamma-globulin and several transfusions of random donor platelets and showed a good clinical course. This is the second reported case of NAITP associated with the Yuk antigen system having intracranial hemorrhage.

Antigens, Human Platelet↗

Three-dimensional visualization of basal body structures and some cytoskeletal components in the apical zone of tracheal ciliated cells.

The ciliated cells of tracheal epithelium were mechanically fragmented to remove the cytoplasmic soluble contents, and the apical zone was examined to clarify the three-dimensional structures of basal body and cytoskeletal filaments using freeze-fracture-etch approaches. The basal body was connected to the apical plasma membrane by definite laminae, formerly called alar sheets. The distal one-half of the basal foot was composed of several smooth-surfaced 12-nm fibrils. Intermediate filament networks extended to the lower half plane of the basal body, and enmeshed the basal body tightly by tiny 5- to 8-nm fibrils. Actin core bundles of microvilli also had tiny crosslinking fibrils. Some actin filaments were seen to run horizontally at the upper half plane of the basal body. Tracheal cilated cells also had circular actin filament bundles just inside the zonula adherens as many other epithelial cells. These cytoskeletal networks which enmeshed both basal bodies and core filaments of microvilli may function as a coordinator of ciliary beating.

Actins↗

Synthesis and properties of an oligodeoxynucleotide modified with a pyrene derivative at the 5'-phosphate.

The synthesis of an oligonucleotide (ODN) modified with pyrene (pyr) on the 5'-phosphate is described. The ODN and pyrene are joined through a linker composed of four methylene groups. Modification of the oligonucleotide was effected via condensation of the 2-cyanoethyl N,N-diisopropylphosphoramidite of 4-(1-pyrenyl)butanol (pyr-m4OPAm, 2) with the 5'-OH of an ODN. This derivative is suitable for incorporation into automated solid-phase DNA synthesis and was attached to the 5' terminus of the DNA chain through a phosphodiester linkage. The properties of the 5'-(pyr-m4)d(T)15 (3) and the duplex it formed with d(A)15 were investigated by fluorescence and absorbance spectroscopy. The pyrene fluorescence in the modified duplex was quenched 96.3% relative to an identical concentration of free 4-(1-pyrenyl)butanol. The ultraviolet spectrum of the 5'-(pyr-m4)-d(T)15 and 5'-(pyr-m4)-d(T)15-d-(A)15 modified duplex, in the 320-360-nm region, was red-shifted 6 nm relative to the free 4-(1-pyrenyl)-butanol. The Tm values of the unmodified and modified duplexes at 0.1 M NaCl were 34.9 and 41.9 degrees C, respectively. The pyrene-induced stabilization corresponds to a free energy change (delta delta G degrees) of -2.6 kcal/mol.

Oligonucleotides↗

Striped iron zoning of olivine induced by dislocation creep in deformed peridotites.

Deformation of solid materials affects not only their microstructures, but also their microchemistries. Although chemical unmixing of initially homogeneous multicomponent solids is known to occur during deformation by diffusion creep, there has been no report on their chemical zoning due to deformation by dislocation creep, in either natural samples or laboratory experiments. Here we report striped iron zoning of olivine ((Mg,Fe)2SiO4) in deformed peridotites, where the iron concentration increases at subgrain boundaries composed of edge dislocations. We infer that this zoning is probably formed by alignment of edge dislocations dragging a so-called Cottrell 'atmosphere' of solute atoms (iron in this case) into subgrain boundaries during deformation of the olivine by dislocation creep. We have found that the iron zoning does not develop in laboratory experiments of high strain rates where dislocations move too fast to drag the Cottrell atmosphere. This phenomenon might have important implications for the generation of deep-focus earthquakes, as transformation of olivine to high-pressure phases preferentially occurs in high-iron regions, and therefore along subgrain boundaries which would be preferentially aligned in plastically deformed mantle peridotites.

Journal Article↗

Clinical evaluation of sodium hyaluronate for the treatment of patients with rotator cuff tear.

A randomized study of two types of conservative treatment of 78 shoulders in 78 patients with rotator cuff tears was performed. Twenty-five milligrams of sodium hyaluronate (SH) was injected into shoulders in one group (SH group) and 2 mg of dexamethasone was injected in the other group (steroid group). Injection of each drug was planned for once per week for 5 consecutive weeks. In the SH group, University of California at Los Angeles score before treatment was 13.6 +/- 2.6 points in 16 patients who did not require surgery (satisfied patients) and 12.8 +/- 3.5 points in 22 patients who required surgery (unsatisfied patients) (not statistically significant). In the steroid group, University of California at Los Angeles score before treatment was 11.9 +/- 3.6 points for 15 satisfied patients and 12.6 +/- 3.9 points for 25 unsatisfied patients (again, not statistically significant). In the SH group, the score at 4 weeks after treatment for satisfied patients increased to 27.6 +/- 3.1 points, whereas that for unsatisfied patients was 14.9 +/- 1.2 points (P <.0001). Similarly, in the steroid group, the score at 4 weeks after the treatment for satisfied patients increased to 26.5 +/- 2.0 points, whereas that for unsatisfied patients was 15.0 +/- 4.0 points (P <.0001). At 24 weeks after treatment, the score for satisfied patients was 26.2 +/- 3.1 points in the SH group and 25.3 +/- 2.5 points in the steroid group. The effective rate of the SH group was 39.5% and that of the steroid group was 35%. Therapeutic efficacy in the SH group was equivalent to that in the steroid group. In both groups, the rate of patients who engaged in manual labor was significantly higher in the group of unsatisfied patients than in that of satisfied patients. No adverse reaction to either treatment was observed. These results suggest that SH is an effective conservative treatment for patients with rotator cuff tears.

Activities of Daily Living↗

Novel class of DNA binding motifs based on bistetrahydrofuran and bisfuran skeleton with long alkyl chains.

Small molecules with DNA-binding affinity within the minor groove have become of great interest. In this paper, new DNA binding molecules; diamino-bistetrahydrofuran (bisTHF) and diamino-bisfuran are reported. The bisTHF ligand with RR configuration at the amino groups and C8 alkyl chains (RR8) stabilized GC-rich duplex. In contrast, bisfuran compounds stabilized AT-rich duplex. The binding affinity of RR8 with 12 mer duplex DNA was determined by isothermal titration calorimetry to be 3.3 x 10(8) M-1.

Binding Sites↗

The role of alpha-galactosylceramide-activated Valpha14 natural killer T cells in the regulation of Th2 cell differentiation.

Valpha14 natural killer T (NKT) cells produce large amounts of both IL-4 and IFN-gamma upon stimulation with a ligand, alpha-galactosylceramide (alpha-GalCer), and play a crucial role in various immune responses, including allergic diseases. Interestingly, Valpha14 NKT cells are not essential for the induction of IgE responses but rather induce suppression of specific IgE production upon activation. The suppression in the IgE production is not detected either in Valpha14 NKT cell-deficient mice or in IFN-gamma-deficient mice. Thus, activated Valpha14 NKT cells are likely to exert a potent suppressive activity on Th2 cell differentiation and subsequent IgE production by producing a large amount of IFN-gamma. In marked contrast, little regulatory effect of IL-4 produced by Valpha14 NKT cells on Th2 cell differentiation is suggested.

Animals↗

Ethnic differences in allele frequencies of two microsatellite markers closely linked to the locus for polycystic kidney disease 1 (PKD1).

Two microsatellite markers, D16S283 and D16S284, closely linked to the locus of autosomal polycystic kidney disease (PKD1), were amplified in a Japanese population sample by the polymerase chain reaction to investigate differences in allele frequencies between Japanese and Caucasian populations. Ten D16S283 alleles and four D16S284 alleles were discerned among 53 Japanese. The observed heterozygosities of D16S283 and D16S284 in this study were 76.8 and 9.1%, and the polymorphism-informative contents were 0.75 and 0.09, respectively. Several allele frequencies of D16S283 exhibited significant differences. The Y9 allele (19 CA repeats, 91 bp) was the most frequent in both populations but its frequency in Caucasians was higher. The second most frequent allele was different: Y6 (22 CA repeats, 97 bp) in Japanese and Y10 (18 CA repeats, 89 bp) in Caucasians. Y8 (20 CA repeats, 93 bp) and Y11 (17 CA repeats, 87 bp) alleles also showed different frequencies. For D16S284, no differences in allele frequencies were observed between the two populations. As we observed differences in allele frequencies for D16S283, an association study with this polymorphism should carefully control for the ethnic origin of subjects.

Alleles↗

Flow cytometric analysis of p53 expression during the cell cycle.

Mutant p53 expressed in many types of carcinoma lacks an inhibitory function on cell growth, but its role has been unclear. We performed two-parameter flow cytometry (FCM) to elucidate the relationship between the expression of p53 and the cell cycle in A431 cells. Fluorescence in situ hybridization proved that an A431 cell had two p53 genes whereas chromosome 17 was tetraploid. FCM showed that A431 cells expressed constantly high levels of p53 during the cell cycle. Under conditions of both serum deprivation and presence of hydroxyurea, p53 expression was decreased throughout the cell cycle, and the bivariate DNA/p53 distribution pattern during the cell cycle did not change. The expression of p53 was reduced to 60% for the first 4 h after the addition of cycloheximide, and showed no significant changes at least for 20 h. Treatment with Triton X-100 increased p53 immunoreactivity throughout the cell cycle. These results indicate that mutant p53 differs from proliferative markers such as PCNA, Ki-67 and DNA polymerase-alpha, and that there are no links between the expression of p53 and the cell cycle in A431 cells.

Cell Cycle↗

Influence of vagal pyloric branches on gastric acid secretion and gastrointestinal motility in patients following a pylorus preserving pancreatoduodenectomy.

BACKGROUND/AIMS: The authors evaluated the influence of the vagal pyloric branches on the gastrointestinal function in patients who underwent a pylorus preserving pancreatoduodenectomy (PPPD). METHODOLOGY: Twenty-seven patients with pancreatobiliary and duodenal diseases underwent a PPPD between 1991 and 1994. We analyzed several variables including the daily volume of gastric juice, days of gastric suctioning, start of diet, gastric acid, and gastrin levels. In addition, a gastric emptying scintigram and gastrointestinal manometry were measured. These variables were compared between two groups, namely, those with retained superior pyloric branches of the vagus nerve (preserved group: n = 14), and those without these branches (non-preserved group: n = 13). RESULTS: There were no significant differences in basal acid output, maximum acid output, or plasma gastrin levels between the preserved group and the non-preserved group. In addition, a gastric emptying scintigram demonstrated no difference between the two groups. Finally, on gastrointestinal manometry, there was no significant difference between the two groups during gastric and jejunal phase III activity of migrating motor complex. CONCLUSIONS: Preservation of the vagal pyloric branches did not influence gastric exocrine and endocrine secretion, nor did it effect the gastric emptying of patients who underwent a PPPD.

Adult↗