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Biomedical subjects

J Yano

Publications and source records attributed to J Yano.

At least 37 records · Page 2Linked to original sources
PubMed1999

Inhibition of cancer cell growth by polyinosinic-polycytidylic acid/cationic liposome complex: a new biological activity.

A complex of polyinosinic-polycytidylic acid [poly(I) x poly(C)] and cationic liposome (LIC) inhibited the growth of many tumor cell lines at low concentration in vitro, but poly(I) x poly(C) alone had no such antiproliferative effect. The IC50 values of LIC against the tumor cells ranged from 0.1 to 1000 ng/ml. LIC had strong cytotoxic effects on malignant cells of epithelial and fibroblastic origin from various tissues and was also effective against Adriamycin-resistant tumor cells. LIC did not significantly affect the growth of lymphoma cells, leukemia cells, normal diploid fibroblasts, or primary liver cells at concentrations up to 10 microg/ml. The mechanism of the antiproliferative effect of LIC against malignant cells was the induction of apoptosis. LIC induced the fragmentation of nuclear DNA and the degradation of rRNA in tumor cells. The DNA fragmentation occurred within 1-5 h after the addition of LIC, and both the fragmentation and the inhibition of cancer-cell growth were suppressed by a nuclease inhibitor. In contrast, caspase inhibitors did not affect the antiproliferative activity of LIC. These results suggest that LIC induced apoptosis in malignant cells through the direct activation of nucleases and not through the activation of caspases. LIC reduced the incidence and the size of metastatic liver-cancer tumors in two different mouse metastatic liver-cancer models using human colon carcinoma cells. Histochemical analysis revealed that the KM12-HX cells in the tumor nodules were undergoing apoptosis; therefore, LIC also induced the apoptosis of tumor cells in vivo. In these animal models, LIC caused no observed changes in normal hepatocytes.

Animals↗
PubMed1999

Molecular interactions and kinetic properties of fats.

This article has reviewed the recent work on the molecular interactions and kinetic properties of the polymorphic transformations of the TAGs in the single and mixed states. Progress has recently been made in the molecular-level understanding of the polymorphic transformations of the TAGs. Particularly, the use of the time-resolved X-ray diffraction with Synchrotron radiation (SR-XRD) has provided precise information of the structural changes of the fat crystals at a time scale of 10 sec. Therefore, fruitful information was obtained on the kinetic and molecular aspects of crystallization and mixing processes of the various types of mixed-acid TAGs, which were not obtained with the traditional thermal and structural techniques because of their complicated structural properties. One may anticipate that, although the experimental sites and machine times are limited, the SR-XRD techniques will be more applied to the fat systems involving the following materials and systems; (a) multicomponent natural fats with and without additives of emulsifiers, proteins and carbohydrates, (b) fats in dispersed phases such as oil-in-water (O/W) and water-in-oil (W/O) emulsions, (c) crystallization and transformation processes under external influences of hydrostatic pressure and shear stress [68].

Fats↗
PubMed1999

Distribution of alpha1-adrenoceptor subtype mRNAs in human renal cortex.

OBJECTIVE: To determine the quantity and distribution of alpha1-adrenoceptor subtype mRNAs in human renal cortex. MATERIALS AND METHODS: Specimens of renal cortex tissue were obtained at the time of radical nephrectomy or total nephroureterectomy from 46 patients (mean age 59.0 years, sd 14.7) with renal cell carcinoma, renal pelvic or ureteric tumour. Using the reverse-transcriptase polymerase chain reaction (RT-PCR), the RNase protection assay and in situ hybridization, the presentation, quantity and distribution of alpha1-adrenoceptor subtype mRNAs were determined. RESULTS: Expression of the three alpha1-adrenoceptor subtype mRNAs (alpha1a, alpha1b and alpha1d) was confirmed in the arteries of the renal cortex (arciform, interlobular, arteriole), but among the three subtypes, the alpha1b was less apparent by in situ hybridization. Intense alpha1-mRNA staining was apparent especially in the smooth muscle of arterial walls. In both proximal and distal renal tubules, each of the alpha1-mRNAs was less marked in cytoplasm than in the arteries. In the glomeruli weak staining was detected in the endothelium but there was no obvious staining in the veins. RT-PCR showed all three subtypes of alpha1-adrenoceptor. The RNase protection assay showed that the predominant alpha1-adrenoceptor subtype mRNA in human renal cortex was alpha1a. However, the abundance of alpha1a-mRNA in human kidney was much less than in the prostate. CONCLUSION: Three alpha1-adrenoceptor subtype mRNAs were recognized in human renal cortex and detected particularly in the smooth muscle of the arteries. There was more alpha1a-adrenoceptor subtype in human renal cortex than the other subtypes. It is not known how each subtype operates against adrenergic stimulation; further studies are needed to examine receptor density or receptor function.

Adult↗
PubMed1999

Gene expression of prothrombin in human and rat kidneys: basic and clinical approach.

Prothrombin has remarkable affinity for calcium oxalate crystals. It is produced in renal tubular cells and is detected as a urinary form of prothrombin F1. The aim of this basic study was (1) to isolate prothrombin mRNA from normal human and rat kidneys; (2) to confirm expression level changes in stone-forming rat kidneys; and (3) to analyze the DNA sequence of renal prothrombin. The aim of the clinical investigation was to measure the serum levels of renal prothrombin in clinical cases of various urologic diseases. The expression of prothrombin mRNA in human kidneys and male Wistar rat kidneys was investigated using reverse transcription-PCR, with prothrombin (F1, F2, and thrombin) primers. Renal prothrombin levels were measured in the sera of patients with renal cell carcinoma, renal transplant donors, patients with chronic renal failure, and renal transplant recipients, using an enzyme-linked immunosorbent assay. Expression of cyclophilin as well as prothrombin mRNA could be detected. Prothrombin mRNA expression levels seemed to be increased in stone-forming rats. The DNA sequence of renal prothrombin differed from that of liver prothrombin at three points. Repeated measurements of renal prothrombin showed that values were high during the acute tubular necrosis period and tended to decrease with the recovery of renal function. Prothrombin mRNA expression could be confirmed in human and rat kidneys, as well as in stone-forming rat kidneys. Serum concentration measurements can be considered useful for assessment of recovery from acute tubular necrosis after renal transplantation and for diagnosis of acute rejection.

Adult↗
PubMed1999

Inhibition of metastatic carcinoma cell growth in livers by poly(I):poly(C)/cationic liposome complex (LIC).

The complex of poly(I):poly(C) and a new cationic liposome (LIC) has a potent antitumor activity against many tumor cell lines in vitro, whereas poly(I):poly(C) itself has no such activity. In the present study we tested the sensitivity of 21 human colon and pancreatic cancer cell lines to LIC or Adriamycin in vitro. The growth of most of the cell lines was strongly inhibited by both LIC and Adriamycin in vitro, although a few insensitive cell lines were different. We also studied the in vivo antitumor activity of LIC or Adriamycin in three experimental liver metastasis models in nude mice using a human pancreatic cancer cell line (AsPC-1) and two human colon cancer cell lines (Ls174T and HCC-M1544). The administration of LIC or Adriamycin was started 3 days after the injection of tumor cells. Animals received 0.1 mg/kg LIC IV twice weekly or 5 mg/kg Adriamycin IV every 5 days during the experiments. LIC showed potent antitumor activity in all three liver cancer models. Although Adriamycin had potent antitumor activity in the HCC-M1544 model, it had only a moderate effect in the AsPC-1 model and at most a weak effect in the Ls174T model. At the effective doses LIC did not cause detectable pathological changes in the liver and did not elicit toxicity to mice in these models, whereas Adriamycin did exhibit toxic effects. These results suggest that LIC is a promising candidate drug to treat hepatic metastasis.

Animals↗
PubMed1999

Structural analyses of polymorphic transitions of sn-1, 3-distearoyl-2-oleoylglycerol (SOS) and sn-1, 3-dioleoyl-2-stearoylglycerol (OSO): assessment on steric hindrance of unsaturated and saturated acyl chain interactions.

Polymorphic transformations in two saturated-unsaturated mixed acid triacylglycerols, SOS (sn -1,3-distearoyl-2-oleoylglycerol) and OSO (sn -1,3-dioleoyl-2-stearoylglycerol), have been studied by FT-IR spectroscopy using deuterated specimens in which stearoyl chains are fully deuterated. A reversible phase transition between sub alpha and alpha and a series of irreversible transitions (alpha-->gamma-->beta'-->beta (beta2, beta1) for SOS and alpha-->beta'-->beta for OSO) were studied with an emphasis on the conformational ordering process of stearoyl and oleoyl chains. The alpha-->sub alpha reversible transition was due to the orientational change of stearoyl chains in the lateral directions from the hexagonal subcell to a perpendicularly packed one. As the first stage of the series of irreversible transitions from alpha to beta, the conformational ordering of saturated chains took place in the alpha-->gamma transition of SOS and in the alpha-->beta' transition of OSO; one stearoyl chain in SOS and OSO takes the all-trans conformation and the second stearoyl chain in SOS takes the bent conformation like those observed in the most stable beta-type. As the final stage, the ordering of unsaturated chains occurred in the beta'-->beta transition both for SOS and OSO. A conversion in the layered structure from bilayer to trilayer was also accompanied by the conformational ordering in the alpha-->gamma transition of SOS and in the beta'-->beta transition of OSO.

Allosteric Site↗
PubMed1998

Diversity in the fatty-acid conformation and chain packing of cis-unsaturated lipids.

Recent X-ray diffraction and Fourier transform IR spectroscopic studies have unveiled a great diversity in the molecular conformation and chain packing of lipid molecules containing cis-unsaturated fatty-acid chains. Specifically, a dramatic diversity in the olefinic conformation, subcell packing and chain-chain interactions has been clearly revealed by crystal structures of principal cis-monounsaturated fatty acids. The structural diversity is most manifest in oleic acid crystals. These findings were applied to analyses of the complicated structural transformation of diacylglycerols and triacylglycerols containing oleic acid and saturated acid moieties, in which the stabilization of the oleic acid causes the complexity of the transformation and mixing behavior. Although this knowledge has been obtained in the crystalline state, one may assume that the structural diversity of these unsaturated molecules plays a similar role in the lipids of biomembranes, lipoproteins and lipid deposits in which aliphatic chain packing is a critical problem, since most lipid domains can undergo liquid to solid or solid to liquid alterations.

Crystallization↗
PubMed1998

Quantification and distribution of alpha1-adrenoceptor subtype mRNAs in human proximal urethra.

1. We performed RNase protection assays and in situ hybridization to investigate the ratio of the three alpha1-adrenoceptor subtype mRNAs, alpha1a, alpha1b and alpha1d, in human proximal urethra, and their localization in urethral cross-sections. As revealed by the RNase protection assays, alpha1a was the predominant subtype mRNA in both male and female urethral samples. Alpha1d mRNA was detected only in the female sample, and alpha1b mRNA was not detected in any of the samples tested. The ratio of the abundance of the subtype mRNAs, alpha1a:alpha1b:alpha1d, was 100:0:0 in the male urethra and 90:0:10 in the female urethra. 2. In situ hybridization studies showed no significant differences in the cross-sectional distribution of alpha1-adrenoceptor subtype mRNAs between male and female urethras. Intense alpha1a staining was observed in the smooth muscle of the urethra, but alpha1b and alpha1d staining was much less intense. 3. Of the three cloned alpha1 subtypes, alpha1a is the most likely to be responsible for the contraction of the human urethra. Owing to the side effects of nonselective alpha1 drugs, alpha1-selective drugs may be clinically superior to nonselective drugs for the treatment of urethral disorders.

Aged↗
PubMed1998

An epitope localized in c-Src negative regulatory domain is a potential marker in early stage of colonic neoplasms.

In previous work, we established a new monoclonal antibody that specifically recognizes the active form of c-Src tyrosine kinase (Kawakatsu et al, 1996). To determine whether c-Src is active in colorectal tumorigenesis, we examined the expression of an active form of c-Src in human normal mucosa, hyperplastic polyps, adenomas, and adenocarcinomas. The tissue distribution of the active form of c-Src was studied by immunohistochemistry using this antibody, termed Clone 28. Among 66 cases of adenoma tested, 61 (92%) showed positive staining (adenoma with mild atypia, 3 of 3; adenoma with moderate atypia, 38 of 42; adenoma with severe atypia, 20 of 21). In contrast to the frequent and intense staining in adenomas, adenocarcinoma showed weak staining with less frequency in 4 of 16 (25%) cases. The number of specimens with positive staining in well- and moderately differentiated adenocarcinomas was limited to an early stage. The active form of c-Src mainly localized to the nuclear membrane and the perinuclear region. These results provide the first direct evidence that the activation of c-Src appears to be an early event in colonic carcinogenesis in situ. The findings of the present study thus allow us to propose a molecular mechanism involving c-Src activation in the process of malignant transformation of the human colonic neoplastic cells.

Antibodies, Monoclonal↗
PubMed1998

Nitric oxide: a possible etiologic factor in spinal cord cavitation.

To determine whether nitric oxide (NO) is related to spinal cord cavitation, we treated mice that underwent spinal cord injury with NG-mono-methyl-L-arginine (N-MMA). Spinal cord specimens were subjected to glial fibrillary acidic protein (GFAP) immunostaining, which is selective for astrocytes. Spinal cord cavities and GFAP-positive glial cells appeared simultaneously at 3 days after spinal cord injury, and the cavities enlarged at 7 days. In mice receiving N-MMA, the cavities were significantly smaller than those in the mice that underwent spinal cord injury only. However, the numbers of GFAP-positive cells showed no difference between these two groups. These experimental findings suggest that cavitation of the spinal cord is caused mainly by NO released from activated glial cells.

Animals↗
PubMed1997

Identification of alpha 1-adrenoceptor subtypes in the human prostatic urethra.

To identify the alpha 1-adrenoceptor subtypes in the human prostatic urethra, we compared the potencies of various alpha 1-adrenoceptor agonists and antagonists in inhibiting [3H]tamsulosin binding to human prostatic urethral membranes with their potencies in inhibiting the binding of (+)-beta-([125I]iodo-4-hydroxyphenyl)ethylaminomethyl-tetralone ([125I]HEAT) to cloned human alpha 1a, alpha 1b and alpha 1d subtypes. The alpha 1A-selective antagonists 5-methylurapidil and (+)niguldipine showed higher affinities for both cloned alpha 1a and urethral alpha 1-adrenoceptors than for cloned alpha 1b- and alpha 1d-adrenoceptors. NS-49, (R)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethanesulfonanilide hydrochloride, recently characterized as an alpha 1A-selective agonist, also showed high affinity for the cloned alpha 1a subtype and urethral alpha 1-adrenoceptors. Prazosin showed lower affinity for alpha 1-adrenoceptors in the human prostatic urethra than for any of the three cloned alpha 1-adrenoceptors. Comparison of the affinities of alpha 1-adrenoceptor agonists and antagonists for human prostatic urethral alpha 1-adrenoceptors to their affinities for the three cloned alpha 1 subtypes indicated a close correlation between the affinities for human urethral alpha 1 and the cloned alpha 1a-adrenoceptors. However, prazosin did not conform to this pattern. These findings suggest that the predominant alpha 1-adrenoceptor in the human urethra is the alpha 1A subtype, and that an alpha 1L subtype which has been characterised by its low affinity for prazosin, may also be present.

Adrenergic alpha-Agonists↗
PubMed1997

Quantification and distribution of alpha 1-adrenoceptor subtype mRNAs in human vas deferens: comparison with those of epididymal and pelvic portions.

1. This study was intended to quantify the amounts of the alpha 1-adrenoceptor subtype mRNAs in human vas deferens, and demonstrate the receptor subtype responsible for the vas contraction. 2. The RNase protection assay showed that the mean total amount of alpha 1a mRNA was 7.4 +/- 2.2 pg/5 micrograms of poly (A)+ RNA (97.0% of the total alpha 1 mRNA) in the epididymal portion (E-vas) and 4.9 +/- 0.8 pg/5 micrograms of poly (A)+ RNA (96.3% of the total) in the pelvic portion (P-vas). The E-vas showed a tendency to have a greater alpha 1a mRNA abundance than the P-vas (P = 0.11). The alpha 1b and alpha 1d mRNAs were absent or of extremely low abundance. 3. By an in situ hybridization, the alpha 1a and alpha 1d mRNAs were recognized in the smooth muscle cells of the E-vas and the P-vas, and the distribution pattern the same in both tissue. The alpha 1b mRNA positive site was scarcely detectable in both vas portions. 4. In a functional study, l-phenylephrine produced concentration-dependent contraction in the E-vas (Emax = 2.24 +/- 0.70 g; pD2 = 5.32 +/- 0.09) and the P-vas (Emax = 2.46 +/- 0.46 g; pD2 = 5.07 +/- 0.12). KMD-3213, a novel alpha 1A-adrenoceptor-selective antagonist, caused parallel rightward shifts of the concentration-response curves for l-phenylephrine. Apparent pKB values were 9.90 +/- 0.16 for the E-vas and 9.71 +/- 0.17 for the P-vas. There was no significant difference in Emax, pD2 or pKB estimates between the two portions. 5. We have found that alpha 1a mRNA is predominant in the human vas deferens, and confirmed that contraction of this organ is mediated by the alpha 1A-adrenoceptor.

Aged↗
PubMed1997

The phylogeny of species of the genus Issatchenkia Kudriavzev (Saccharomycetaceae) based on the partial sequences of 18S and 26S ribosomal RNAs.

The ten strains of Issatchenkia species were examined for their partial base sequences of 18S and 26S rRNAs. In the 18S rRNA partial base sequences (positions 1451-1618, 168 bases), the strains of the species of the genus Issatchenkia were found to be not uniform phylogenetically. The calculated base differences numbered 5-0. The strains of Issatchenkia species examined had 3-1 base differences with the type strain of Pichia membranaefaciens. Especially, the type strain of Issatchenkia orientalis, the type species of the genus Issatchenkia was found to be closely related phylogenetically to that of P. membranaefaciens. The calculated number of base differences was only one. The base sequences on the fingerprint segment were comprised of four bases (four kinds of AUAU, CCAU, AUAG, and ACAU), as found in P. membranaefaciens (ACAA). In the 26S rRNA partial base sequences, the calculated number of base differences was 8-0 (positions 1611-1835, 225 bases), and the calculated percent similarities were 61-80 (positions 493-622, 130 bases), within the genus Issatchenkia. Discussion was made phylogenetically and taxonomically, especially on the phylogenetic relationship between the type species of the genera Issatchenkia and Pichia and on a circumscription of the genus Issatchenkia.

Base Sequence↗
PubMed1997

[Serodiagnosis with trehalose-6,6'-dimycolate of pulmonary tuberculosis].

Enzyme-linked immunosorbent assay (ELISA) was used to examine serum antibody levels of mycobacterial antigen in 92 patients with active tuberculosis, 36 with cured tuberculosis, 45 with nontuberculous mycobacteriosis, and as 31 with other diseases. Glycolipid fraction containing mainly cord factor (trehalose-6,6'-mycolate) from Mycobacterium tuberculosis H37Rv were used as ELISA antigen. Overall positive rates of the ELISA tests in the patients with active pulmonary tuberculosis, those with nontuberculous mycobacteriosis, and those with other diseases were 67.4%, 75.6%, and 6.5%, respectively. Patients with tuberculosis and those with nontuberculous mycobacteriosis differed from the control group (p < 0.0001). Higher positive rates were correlated with bacterial loads (smear-positive vs smear-negative, p < 0.01) and with chest roenrgenographic findings (far advanced or other cavitary vs noncavitary, p < 0.01). Because 18 of 36 smear-negative patients (50%) had positive results, we believe that the ELISA test with this antigen can be useful for diagnosis of M. tuberculosis, especially in patients with smear-negative.

Antibodies, Bacterial↗
PubMed1996

A new monoclonal antibody which selectively recognizes the active form of Src tyrosine kinase.

Phosphorylation and dephosphorylation of Tyr-530 in human c-Src (Tyr-527 in avian c-Src) is critical in regulating c-Src kinase activity. So far, it has not been possible to distinguish the active and inactive forms in vivo. We now report a new monoclonal antibody that selectively recognizes the active form of c-Src. This antibody, termed clone 28, recognized a region adjacent to Tyr-530 (Q529YQP532) in the C-terminal regulatory domain of c-Src, and its binding was hindered by phosphorylation of this tyrosine as determined by peptide competition assay. Combined immunoprecipitation/Western blotting revealed that clone 28 reacted with a 60-kDa protein that was precipitated by mAb 327, a well known monoclonal antibody against v-Src and c-Src. Cyanogen bromide cleavage and two-dimensional tryptic maps confirmed that clone 28 was specific for the active form (Tyr-530 not phosphorylated), whereas mAb 327 recognized the inactive form (Tyr-530 phosphorylated) as well as the active form. Clone 28 selectively immunoprecipitated the active form and augmented its kinase activity. Preabsorption experiments revealed that clone 28 could not completely immunoprecipitate the mAb 327 binding 60-kDa protein in either an in vitro or an in vivo phosphorylation system. These observations, taken together, strongly suggest the existence of multiple forms of c-Src as proposed by Cooper and Howell (1993) (Cooper, J. A., and Howell, B. (1993) Cell 73, 1051-1054). Using clone 28, we demonstrated a distinct localization of the active form of c-Src within cultured normal fibroblast cells. In liver tissue sections, we also examined the distribution of the active form in embryonic mice. Megakaryocytes were strongly stained, in contrast to completely negative immunoreactivity in hepatocytes, reticulocytes, and granulocytes. This result provides the first direct evidence that c-Src is highly activated in platelets.

Amino Acid Sequence↗
PubMed1996

Allelic loss of chromosome 16q in endometrial cancer: correlation with poor prognosis of patients and less differentiated histology.

Deletion of certain chromosomal regions can be demonstrated in malignant cells. Chromosome 16q is one of the regions where allelic loss is frequently detected in carcinoma of the breast and many other tumors, suggesting that gene(s) which retard tumor growth may exist here. To elucidate the clinicopathological significance of chromosome 16q, loss of heterozygosity (LOH) was investigated using microsatellite polymorphism analysis in 58 patients with endometrial lesions (50 with endometrial carcinoma and 8 who had hyperplasia with or without atypia). When 11 regions of chromosome 16q were examined, LOH was found in 20 patients with carcinoma (40%) and none of the patients with hyperplasia. The tumors of 9 of the 20 patients (45%) showed total loss of 16q, while the others (55%) showed partial deletion. Tumors with LOH were histologically less differentiated than those without LOH (P = 0.038, chi2 test). Patients with tumors showing LOH of 16q had a worse prognosis than those without LOH according to Kaplan-Meier survival analysis (P=0.0158, log-rank test). In addition, LOH of 16q showed a significant relationship to prognosis by Cox regression analysis. Deletion mapping of 16q demonstrated that two regions (16q22.1 and 16q22.2-23.1) were frequently involved. Patients with 16q22.1 LOH had a poorer prognosis than those with intact 16q22.1 (P=0.0003, log-rank test). These findings suggest that gene(s) of which defect is possibly related to the aggressiveness of endometrial cancer are localized on a limited region of 16q that includes 16q22.1.

Alleles↗