PubMed Health⌕ Search

Biomedical subjects

K Yago

Publications and source records attributed to K Yago.

At least 19 recordsLinked to original sources
PubMed2000

Studies on neurosteroids X. Determination of pregnenolone and dehydroepiandrosterone in rat brains using gas chromatography-mass spectrometry-mass spectrometry.

An assay method for pregnenolone and dehydroepiandrosterone in rat brains is developed using gas chromatography (GC)-electron ionization-mass spectrometry (MS)-MS. The extract of the rat brain homogenate containing deuterated internal standard with organic solvent is purified by silica gel minicolumn chromatography. The obtained fraction is derivatized into methyloxime, treated with dimethylisopropylsilylimidazole, and then subjected to GC-MS-MS. The method is applied to the determination of these steroids in the gray matter and olfactory bulbs of rat brains, which are divided into control and acute stressed specimens. Although pregnenolone in both regions of the rat brains increases more than three times after stress, dehydroepiandrosterone in both regions is not so clearly influenced by stress.

Animals↗
PubMed1999

Studies on neurosteroids. IX. Characterization of estrogens in rat brains using gas chromatography-tandem mass spectrometry.

The characterization of the classical estrogens (estrone, estradiol, estriol) and guaiacol estrogens (2-hydroxyestrone 3-methyl ether, 4-hydroxyestrone 3-methyl ether) in rat brains was performed using gas chromatography-tandem mass spectrometry (GC-MS-MS). Estrogens were purified from Wistar strain rat brains by some chromatographic pre-treatments, such as solid-phase extraction, preparative thin-layer chromatography or preparative high-performance liquid chromatography. After the derivatization with O-methylhydroxylamine and/or N,O-bis(trimethylsilyl)trifluoroacetamide, estrogens were identified by comparison of their chromatographic behavior during GC-MS-MS operating in the product ion scan mode and comparison with the product ion MS spectra of an authentic sample. These evidences suggested that estrogens exist in rat brains as neurosteroids or neuroactive steroids.

Animals↗
PubMed1999

Plasma membrane disruption underlies injury of the corneal endothelium by ultrasound.

The nature and the extent of acute injury to corneal endothelial cells caused by exposure to ultrasound radiation were characterized, as well as the long-term reaction of these cells to this form of injury. It was found that the degree of lethal cell injury induced by ultrasound scaled with exposure intensity and duration. Immediate changes in plasma membrane permeability were induced by ultrasound exposure. This ultrasound-induced permeability change was, however, transient in many cells, allowing them to trap and retain a normally impermeant tracer, fluorescein dextran, in cytosol. Microvilli were present on ultrasound treated cells in far greater density than on control cells, characteristic of exocytosis-based resealing. Cultures containing a majority of transiently permeabilized endothelial cells were morphologically indistinguishable from untreated control cultures, and the fluorescein dextran-labeled cells in these populations locomoted and divided normally. We conclude that cell death due to ultrasound exposure can occur rapidly via a necrotic mechanism that can be attributed to mechanically induced damage to the plasma membrane. However, not all cells injured become necrotic: some survive and appear to behave normally after exposure. Conditions that favor plasma membrane disruption resealing, e.g. that result in sub-lethal rather than lethal cell injury, may mitigate the reduction in corneal endothelial cell density consequent on phacoemulsification and aspiration surgery.

Animals↗
PubMed1999

[A consideration on the results of nationwide surveillance of antimicrobial susceptibilities--gram-negative bacilli].

The results of the semi-annual nationwide surveillance of antimicrobial susceptibilities, conducted by the Japanese Ministry of Health and Welfare during the period of January 1993 to July 1995, were analyzed for typical Gram-negative bacilli in the purpose of provision of an index for antimicrobial selection. During these 3 years, Escherichia coli, Citrobacter freundii, Enterobacter aerogenes and Proteus mirabilis showed slightly increasing tendency in susceptibility to fosfomycin (FOM) and Citrobacter freundii. Klebsiella pneumoniae and Enterobacter aerogenes showed slightly increasing tendency to minocycline (MINO). While Haemophilus influenzae and Haemophilus parainfluenzae showed slightly decreasing tendency to cefmetazole (CMZ). However, these annual changes were almost negligible. Generally, these microorganisms showed relatively good susceptibilities, every year, to the principal antimicrobial agents being approved for use against Gram-negative bacilli. However, Enterobacter cloacae, Enterobacter aerogenes, Serratia marcescens and Pseudomonas aeruginosa showed tendencies of decreased susceptibility to some of the antimicrobial agents. On the other hand, sulfamethoxazole-trimethoprim (ST), CMZ, latamoxef (LMOX), gentamicin (GM) and amikacin (AMK) showed good activities against some of the Gram-negative bacilli to which no indications are approved. In conclusion, bedside the identification of the causative microorganisms and the performance of antimicrobial susceptibility testing, such analyses (graphics of susceptibility tendency of clinical isolates to variety of antimicrobial agents) could be used as an index for selection of antimicrobial agents, when emergent and urgent selection of antimicrobial agents is necessary.

Aminoglycosides↗
PubMed1999

[T cell non-depleted bone marrow transplantation for primary refractory erythroleukemia using a partially HLA-mismatched related donor].

We performed an HLA-mismatched T cell non-depleted bone marrow transplant on a 53-year-old man with acute erythroleukemia that was highly resistant to conventional remission-induction chemotherapy. After conditioning that included total body irradiation, the patient received a two-HLA-antigen-mismatched bone marrow graft harvested from his sister using tacrolimus and methotrexate for graft-versus-host disease (GVHD) prophylaxis. He successfully established rapid engraftment accompanied by steroid-responsive GVHD localized to the skin. Although bone marrow samples on day 31 and day 66 disclosed a complete remission with full donor chimerism, the patient relapsed and died of pulmonary infection on day 154. There is evidence that tacrolimus is effective in alleviating GVHD. Selected patients who have partially mismatched related donors with less HLA disparity may benefit from tacrolimus-based T cell non-depleted bone marrow transplants because of the more potent graft-versus-leukemia effect that can be expected compared to transplants using T cell depleted inoculum.

Bone Marrow Transplantation↗
PubMed1999

[Effects of an oxacephem antibiotic on liver function in orthopedic surgery].

The subjects were 531 patients who underwent orthopedic surgery. Flomoxef was administered, and liver function was examined before and after administration. Abnormal liver function after administration of flomoxef was found in 14.3% of patients. In male patients, a high rate of 18.8% was observed. A particularly high rate of 37.0% was obtained among patients who showed GOT values of more than 40 U/L before treatment with flomoxef. The prevalence of abnormal GOT and GPT values after administration of flomoxef was 3.6% and 13.2%, respectively. These values were significantly higher than those obtained with other cephem antibiotics. These rates of occurrence of abnormally high GOT and GPT are obviously higher than those submitted at the time of approval and reported in the drug use investigation. The prevalence of abnormal liver function values was high in patients receiving flomoxef, and particularly high in male patients and patients whose GOT was high before administration of flomoxef. Therefore, sufficient check of liver function appears important when administration of flomoxef to these types of patients is intended.

Adult↗
PubMed1998

[A consideration on the results of nationwide surveillance of antimicrobial susceptibilities--gram-positive cocci and gram-negative cocci].

The results of the semi-annual nationwide surveillance of antimicrobial susceptibilities, conducted by the Japanese Ministry of Health and Welfare during the period of January 1993 to July 1995, were analyzed for typical Gram-positive cocci and Gram-negative cocci in the purpose of provision of an index for antimicrobial selection. During these 3 years, Streptococcus pyogenes (group A) and Streptococcus agalactiae (group B) showed slightly increasing tendency in susceptibility to ofloxacin (OFLX) and sulfamethoxazole/trimethoprim (ST), while Streptococcus pneumoniae and Moraxella (Branhamella) catarrhalis showed slightly decreasing tendency to cefaclor (CCL). However, these annual changes were almost negligible. Generally, these microorganisms showed relatively good susceptibilities, every year, to the principal antimicrobial agents being approved for use against Gram-positive and -negative cocci. However, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis showed tendencies of decreased susceptibility to some of the antimicrobial agents. On the other hand, cefmetazole (CMZ), vancomycin (VCM), latamoxef (LMOX), ST and minocycline (MINO) showed good activities against some of the Gram-positive and -negative cocci to which no indication are approved. In conclusion, beside the identification of the causative microorganisms and the performance of antimicrobial susceptibility testing, such analyses (graphics of susceptibility tendency of clinical isolates to variety of antimicrobial agents) could be used as an index for selection of antimicrobial agents, when emergent and urgent selection of an antimicrobial agent is necessary.

Aminoglycosides↗
PubMed1998

Effect of growth factors on expression of integrin subtypes in microvascular endothelial cells isolated from bovine retinas.

We isolated microvascular endothelial cells from bovine retinas (BREC) by a colony isolation method, and investigated the effects of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) on growth as well as integrin subtype expression of the cultured BREC. Either of the growth factors stimulated growth of the cultured BREC. In non-stimulated BREC, alpha v beta 3 integrin expression was predominant over the other integrin subtypes tested (alpha v beta 5, alpha 2 beta 1 and alpha 5 beta 1), but no enhancement of the alpha v beta 3 expression occurred by either growth factor stimulation. On the other hand, bFGF addition stimulated alpha v beta 5 and alpha 5 beta 1 expression while VEGF induced the alpha 2 beta 1 expression as well. These results suggest that external stimuli such as bFGF and VEGF alter integrin expression profiles of BREC and probably influence interactions of endothelial cells with extracellular matrix during angiogenesis which must be involved in pathogenesis of ischemic retinal disorders. In this respect, this BREC culture system could be useful to study the mechanism of neovascularization in these disorders.

Animals↗
PubMed1996

Characterization of a T cell line specific to an anti-Id antibody related to the carbohydrate antigen, sialyl SSEA-1, and the immundominant T cell antigenic site of the antibody.

The stage-specific embryonic Ag-1 (SSEA-1) is a carbohydrate Ag and regarded as an onco-developmental Ag. Sialyl SSEA-1 Ag, the sialylated form of SSEA-1, is frequently expressed in human cancer cells as well as in murine cancer cells. A mAb, FH-6, was shown to specifically recognize the Ag. We have generated five anti-Id Abs directed to the paratope-related idiotopes of the FH-6 Ab. One of these anti-Id Abs, Id-F2, increased the survival of host mice that were inoculated with Meth-A cells expressing the sialyl SSEA-1 Ag. To clarify the exact mechanism underlying the antitumor effect of the anti-Id Ab, we established a T cell line that recognized Id-F2 in association with MHC class II molecules. The T cell line was CD4+V beta 8+, and produced IL-2, exhibiting helper activity for B cells. The VH CDR2 region of the Id-F2 amino acid sequences turned out to be strongly immunogenic to T cells. When the immune complexes, consisting of the sialyl SSEA-1 Ag, FH-6, and Id-F2, were formed at the Meth-A cell-surface, the T cell line showed a strong proliferative response. The possible roles played by such T cell subsets in the anti-tumor effect are discussed.

Amino Acid Sequence↗
PubMed1996

[Protein binding of clarithromycin in patients with chronic renal failure].

Assessment was made on the serum protein binding of clarithromycin (CAM), a representative oral macrolide, using sera from healthy subjects (HS) and patients with chronic renal failure (CRF) applying equilibrium dialysis in vitro. The protein binding of CAM was 81.9 +/- 1.9%, 85.9 +/- 3.6%, 82.9 +/- 3.3% and 86.8 +/- 3.3% for sera from HS, from patients in conservative treatment (ND), from those receiving hemodialysis (HD) and from those with continuous ambulatory peritoneal dialysis (CAPD), respectively. There was no significant difference among these values. The protein binding of CAM was 82.9 +/- 3.3% and 68.8 +/- 3.5% for sera before and after HD, respectively. There was significant difference between these values. In the study of the protein binding in patients on HD at an albumin concentration of 0.5 mM, the protein binding of CAM for sera was found to be significantly decreased following HD as compared to that prior to HD. The addition of palmitic acid (PA), a common NEFA, to pooled sera from HS, the protein binding of CAM showed no change. These findings suggest that changes in the protein binding of CAM with HD have been possibly caused by an increase in a drug binding inhibiter other than NEFA (PA) or by an allosteric effect on the albumin binding capacity. At therapy using CAM, the possibility of enhanced pharmacological effects and increased adverse reactions of CAM due to decreased protein binding in patients on HD should be considered.

Anti-Bacterial Agents↗
PubMed1994

Orbital reconstruction with hydroxyapatite ceramic implants.

Thirteen patients with fractures of the orbital floor (inferior wall), medial and lateral walls, or so-called "blowout" fractures with or without fractures of the zygoma were treated with artificially made hydroxyapatite ceramic implants made entirely from limestone, some of which were made with computer aided design and computer aided machinery (CAD-CAM) from data obtained from helical computed tomography. Orbital reconstruction with hydroxyapatite ceramic implants is a safe technique which is superior to previous ones in which autogenous or plastic materials were used.

Adult↗
PubMed1993

Expression of alpha-(1,3)-fucosyltransferases which synthesize sialyl Le(x) and sialyl Le(a), the carbohydrate ligands for E- and P-selectins,in human malignant cell lines.

Transcripts of alpha-(1,3)-fucosyltransferases in human epithelial cancer and leukemia cell lines were analyzed by Northern blotting and reverse transcriptase mediated-polymerase chain reaction using specific probes and primers which can discriminate between the transcripts derived from the four alpha-(1,3)-fucosyltransferase genes Fuc-TIII, IV, V, and VI. Flow cytometric analysis of the sialyl Le(x) and sialyl Le(a) antigens was also performed on the same cell lines. The sialyl Le(x) antigen was expressed on 14 of 15 epithelial cancer cell lines, and the sialyl Le(a) antigen was detected on 8 of them. The message of Fuc-TIII was detected in most of the epithelial cancer cell lines (14 of 15), which correlated with the surface expression of these carbohydrate determinants. In addition, the messages of Fuc-TIV and Fuc-TVI were detected in most epithelial cancer cell lines, while the message of Fuc-TV was undetectable in most of them. On the other hand, all leukemia cell lines were positively stained for sialyl Le(x), but none of them was stained for sialyl Le(a) in flow cytometry. The messages of Fuc-TIV++ were detected in all leukemia cell lines tested. Small quantities of Fuc-TIII, V, and/or VI messages were also detected in some leukemia cell lines in reverse transcriptase mediated-polymerase chain reaction analysis. These studies indicate that alpha-(1,3)-fucosyltransferase activities in epithelial cancer and leukemia cell lines are mixtures of multiple molecular species of alpha-(1,3)-fucosyltransferases. It is natural that epithelial cancer cells contain a significant amount of Fuc-TIII mRNA and leukemia cell lines contain Fuc-TIV mRNA, since their normal counterparts, normal epithelial cells and leukocytes, respectively, are known to contain these fucosyltransferases. The unexpectedly frequent occurrence of Fuc-TIV mRNA in epithelial cancer cell lines may be related to their retro-differentiation associated with tumorigenesis. Another unexpected finding was a weak but significant expression of the alpha-(1,3)-fucosyltransferases Fuc-TIII, V, and/or VI in leukemia cell lines detected by reverse transcriptase mediated-polymerase chain reaction analysis. Since these enzymes are known to be capable of synthesizing the sialyl Le(x) determinant, this finding implies a possibility that some of them may be involved in the synthesis of sialyl Le(x) in leukemia cells.

Adenocarcinoma↗
PubMed1993

Immunoglobulin variable region sequences of two human monoclonal antibodies directed to an onco-developmental carbohydrate antigen, lactotetraosylceramide (LcOse4Cer).

A human monoclonal antibody, 11-50, was generated and was shown to recognize an onco-developmental carbohydrate antigen, LcOse4Cer. The isotype of this antibody was IgM, lambda, similar to the previously known human anti-LcOse4 antibodies, such as IgMWOO and HMST-1. We raised a murine anti-idiotypic antibody G3 (IgG1, kappa) against 11-50, and tested its reactivity towards the affinity purified human polyclonal anti-LcOse4 antibodies prepared from pooled human sera using a Gal beta 1-->3GlcNAc beta-immobilized column. The results indicated that at least a part of the human polyclonal anti-LcOse4 antibodies shared the G3 idiotype with 11-50. We further analyzed the sequence of variable regions of the two anti-LcOse4 antibodies, 11-50 and HMST-1. Sequence analysis of the heavy chain variable regions indicated that the VH regions of these two antibodies were highly homologous to each other (93.5% at the nucleic acid level), and these antibodies utilized the germline genes VH1.9III and hv3005f3 as the VH segments, which are closely related germline genes of the VHIII family. It was noted that these germline VH genes are frequently utilized in fetal B cells. The JH region of both antibodies was encoded by the JH4 gene. For the light chain, the V lambda segments of the two antibodies were 96.3% homologous to each other at the nucleic acid level. The V lambda segments of both antibodies showed the highest homology to the rearranged V lambda gene called V lambda II.DS among reported V lambda genes, while the exact germline V lambda genes encoding the two antibodies were not yet registered in available sequence databanks. The amino acid sequences of the J lambda segments of both antibodies were identical. These results indicate that the two human antibodies recognizing the onco-developmental carbohydrate antigen Lc4 are encoded by the same or very homologous germline genes.

Amino Acid Sequence↗
PubMed1993

[Synthesis and antibacterial properties of 3-O-alkyl-D-glucose derivatives].

A series of 3-O-alkyl-1,2-O-isopropylidene-alpha-D-glucofuranoses (3-7), 6-deoxy-3-O-dodecyl-6-halo-1,2-O-isopropylidene-alpha-D-glucofuranose s (9-11), and 6-deoxy-3-O-dodecyl-6-halo-D-glucopyranoses (12-14) were prepared from 1,2; 5,6-di-O-isopropyridene-alpha-D-glucofuranose and their antibacterial activities were evaluated. The compounds having C12 and C14 alkylchains at C-3 of 1,2-O-isopropylidene glucoses were the most effective in vitro antibacterial screening, of which the structure-activity relationships are also discussed.

Bacteria↗
PubMed1993

[Synthesis and antimicrobial properties of methyl 3-O-alkyl-glucopyranosides].

A new type of nonionic surface-active agents containing sugars as the hydrophilic group were synthesized and evaluated for their antimicrobial activity. Methyl 6-deoxy-3-O-dodecyl-6-halo-D-glucopyranoside derivatives showed powerful antimicrobial activity, but no significant differences were observed on the activity with regard to the kinds of anomers as well as halogen atoms.

Bacteria↗
PubMed1992

IgM-producing renal plasmacytoma.

A seventy-six-year-old woman with plasmacytoma presenting as a renal mass died three months after diagnosis. Bone surveys disclosed no lytic lesions. Gallium-67 scan showed an avid uptake of the radionuclide in the renal mass. Histologic and immunofluorescence studies of resected specimens demonstrated that the renal parenchyma was destroyed by sheets of immature plasma cells producing IgM-lambda and by massive deposits of amorphous, eosinophilic substance stained with anti-mu and anti-lambda antisera. The literature is reviewed. We believe this case is the first one of well-documented IgM-producing renal plasmacytoma.

Aged↗
PubMed1992

[Synthesis and antimicrobial properties of 3-O-alkyl and 3-O-haloalkyl-D-glucoses].

A series of 3-O-alkyl and 3-O-haloalkyl-D-glucoses were prepared from 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose and their antibacterial activities were evaluated. The compounds with C12 and C14-alkyl chains were the most effective in vitro antibacterial screening, among 3-O-alkyl and 3-O-haloalkyl derivatives. The 3-O-alkyl derivatives were more effective than 3-O-haloalkyl derivatives.

Bacteria↗