Application of Ethidium Bromide for High-Resolution Banding Analysis of Chromosomes from Human Malignant Cells

Ethidium bromide was added to cultured human leukemic bone marrow and solid tumor cells to evaluate its inhibitory effect on mitotic chromosome condensation and its possible application to high-resolution banding analysis. In most experiments ethidium bromide treatment resulted in a high proportion of mitotic cells having elongated chromosomes, without remarkable reduction in either the mitotic index or quality of metaphase chromosomes. Optimal effect on chromosome length was obtained by adding 10 μg/ml of ethidium bromide during the final 2 hr of culture. Because of the simplicity and reproducibility of the technique involved, ethidium bromide can be used routinely to extend the length of chromosomes for fine-banding analysis of malignant cells.     

Streptozotocin-induced diabetes increases (Ca2+-Mg2+)-ATPase activity in hepatic plasma membranes of rats: Involvement of protein kinase C

The alteration in calcium transport in the liver of rats with streptozocin(STZ)-diabetic state was investigated. STZ (6 mg/100 g body weight) was subcutaneously administered in rats, and 1 or 2 weeks later they were sacrificed by bleeding. STZ administration caused a remarkable elevation of serum glucose concentration. Liver calcium content was significantly increased by STZ administration. Hepatic plasma membrane (Ca²⁺-Mg²⁺)-ATPase activity was markedly elevated by STZ administration. This increase was completely abolished by the presence of staurosporine (10^-7-10^-5 M), an inhibitor of protein kinase C, in the enzyme reaction mixture, suggesting an involvement of protein kinase C signalling. Moreover, the STZ-induced increase in liver plasma membrane (Ca²⁺-Mg²⁺)-ATPase activity was significantly raised by the presence of okadaic acid (10^-5 and 10^-4 M). Meanwhile, the STZ-increased (Ca²⁺-Mg²⁺)-ATPase activity was not appreciably altered by the presence of anti-regucalcin IgG in the reaction mixture, indicating that the activatory protein regucalcin does not participate in the elevation of the enzyme activity. The present study demonstrates that STZ-induced diabetes causes the increase in hepatic plasma membrane (Ca²⁺-Mg²⁺)-ATPase activity of rats.     

Stereoscopic observation of enzyme distribution in lowicryl K4M-embedded specimens by conventional electron microscopy

The present investigation was undertaken to explore the value of the Lowicryl K4M embedding technique for enzyme histochemical examination of semi-thin sections. The low-temperature embedding procedure with Lowicryl K4M was found to provide favorable conditions for preservation of enzyme activity in tissue samples. We tested the histological effects of various fixatives; the best results were obtained using 4% paraformaldehyde when testing for AcPase, AlPase, TPPase, and Mg-ATPase in the dorsal root ganglion. The three-dimensional cellular fine structure could be clearly seen in stereo pair pictures under stereoscopy.     

Isonicotinic acid hydrazide induced changes and inhibition in mycolic acid synthesis in Nocardia and related taxa

The mycolic acid compositions of Nocardia rubra and related bacteria grown in media containing different concentrations of antituberculous isonicotinic acid hydrazide (INH) were determined in detail by gas chromatography-mass spectrometry. On the basis of molecular species composition, average carbon numbers of mycolic acids were calculated. In Nocardia rubra, N. lutea and Rhodococcus rhodochrous IFO-13161, the ratio of mycolic to non-mycolic fatty acids and the average carbon numbers of mycolic acids were decreased at the INH concentrations of higher than 1 g/ml, paralleling with the significant inhibition of growth. In above three species the synthesis of longer chain mycolic acids (longer than C₄₄ or C₄₆) was inhibited more significantly than shorter homologues such as C₃₈ or C₄₀. In contrast, neither growth inhibition nor change in corynomycolic acid composition was observed in Corynebacteria xerosis and Rhodococcus rhodochrous IFO-13165 at the concentration region of INH up to 100 g/ml. The direct mass fragmentographic analysis of the trimethylsilylated (TMS) derivatives of mycolic acid methyl esters, monitoring [M-15] ions of individual molecular species, revealed that the chain shortening of total mycolic acid molecule by INH occurred more greatly in more highly unsaturated subclasses than in less unsaturated subclasses. Furthermore, mass fragmentographic analysis, monitoring fragment ions (A) and (B), due to straight chain and branched chain alkyl units, respectively, demonstrated the inhibition of mycolic acids was not attributed to the shortening of -alkyl chain, but to the inhibition of chain elongation of C₂₈ to C₃₂ straight chain meromycolic acids. It was also indicated the amounts of trehalose mono- and di-mycolate (cord factor) decreased significantly with the addition of INH (1 to 20 g/ml) in the above strains. From the results obtained above, INH appeared to inhibit the synthesis of mycolic acids longer than C₄₄ or C₄₆ specifically by inhibiting chain elongation or desaturation of precursor long chain fatty acids longer than C₂₈ or C₃₀.     

Serum Osteopontin Predicts Degree of Hepatic Fibrosis and Serves as a Biomarker in Patients with Hepatitis C Virus Infection

Background & Aims

Osteopontin (OPN) is a matricellular protein that upregulates during pathogenesis of hepatic fibrosis. The present study was aimed to evaluate whether serum OPN could be used as a biomarker to assess the degree of hepatic fibrosis in patients with hepatitis C virus (HCV) infection.

Methods

Needle biopsy was performed on HCV patients and scored as zero fibrosis (F0), mild fibrosis (F1), moderate fibrosis (F2), severe fibrosis (F3) and liver cirrhosis (F4) based on Masson’s trichrome and α-smooth muscle actin (α-SMA) staining. Serum OPN levels were measured using ELISA and correlated with the degree of fibrosis. Furthermore, the OPN values were correlated and evaluated with platelets count, serum hyaluronic acid (HA), and collagen type IV and subjected to receiver operating characteristic (ROC) curve analysis.

Results

Serum OPN levels were remarkably increased from F0 through F4 in a progressive manner and the differences were significant (P < 0.001) between each group. The data were highly correlated with the degree of hepatic fibrosis. The ROC curve analysis depicted that serum OPN is an independent risk factor and an excellent biomarker and a prognostic index in HCV patients.

Conclusions

The results of the present study indicate that serum OPN levels reflect the degree of hepatic fibrosis and could be used as a biomarker to assess the stage of fibrosis in HCV patients which would help to reduce the number of liver biopsies. Furthermore, serum OPN serves as a prognostic index towards the progression of hepatic fibrosis to cirrhosis and hepatocellular carcinoma.     

Association between common genetic variants in pre-microRNAs and gastric cancer risk in Japanese population

Background: Common single‐nucleotide polymorphisms (SNPs) in microRNAs (miRNA) have been shown to be associated with susceptibility to several human cancers. We evaluated the associations of three SNPs (rs11614913, rs2910164, and rs3746444) in pre‐miRNAs (miR‐196a2, miR‐146a, and miR‐499) with the risk of gastric cancer (GC) and peptic ulcer diseases, and with the severity of Helicobacter pylori‐induced gastritis in Japanese population. Methods: The rs11614913 (C>T), rs2910164 (G>C), and rs3746444 (A>G) SNPs were genotyped in 552 GC, and 697 non‐cancer subjects, including 141 gastric and 73 duodenal ulcer, and 483 non‐ulcer subjects. The degree of histologic gastritis was classified according to the updated Sydney System, and the serum pepsinogen levels were measured in selected 579 and 204 cases. Results: The rs2910164 CC genotype held a significantly higher risk of GC when compared to non‐cancer subjects (adjusted odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.02–1.66, p =.03). Similarly, the rs2910164 C carrier was associated with higher risk of GC when compared to both non‐cancer and non‐ulcer subjects (OR = 1.39, 95%CI = 1.00–1.93, p =.05, adjusted OR = 1.57, 95%CI = 1.09–2.27, p =.016, respectively). The rs2910164 CC genotype was associated with non‐cardia and upper third, diffuse type and advanced stage GC. The rs11614913 TT genotype was associated with higher degree of mononuclear cell infiltration (score 0–1 vs 2～, adjusted OR = 1.62, 95%CI = 1.05–2.49, p =.03). Conclusions: The rs2910164 (G>C) SNP in the miR‐146a is associated with susceptibility to GC. In addition, the rs11614913 (C>T) SNP in the miR‐196a2 is associated with the degree of H. pylori‐induced mononuclear cell infiltration.     

Single-Molecule Analysis of Restriction DNA Fragments Using Fluorescence Correlation Spectroscopy

The cleavage of fluorescence-labeled M13DNA (7250 bp) usingHaeIII,HgaI,BsmAI, andBspMI was analyzed by fluorescence correlation spectroscopy (FCS) in a small volume (1.5 × 10⁻¹⁵liters). The digestion process can be monitored by the decrease in amplitude of the fluorescence correlation function while the original DNA molecule is divided into several fragments by the enzymes. To analyze this reaction by FCS, we derived a practical equation for estimating the number of molecules in the FCS measurements. Under standard enzymatic conditions,HaeIII andBsmAI digested fluorescence-labeled DNA to completion in the range of 8 h, whereasHgaI andBspMI digested the DNA after 40 h. The comparison of recognition sequences suggested that some tagged nucleotides could be inserted between the recognition site and the cleavage site of the slow enzyme group. The decrease in amplitude in the fluorescence correlation function quantitatively monitors the hydrolysis of DNA during the digestion process.     

Tissue-specific binding of nuclear factors to the 5′-flanking region of rat gene for calcium-binding protein regucalcin

The existence of nuclear factors which bind to the 5-flanking region of calcium-binding protein regucalcin gene in rats was investigated. We previously reported that rat regucalcin mRNA is expressed in a highly tissue-specific manner; the mRNA was mainly present in the liver but only slightly in the kidney. When the nuclear proteins extracted from the liver and kidney of rats were used in the gel mobility shift assays, a protein-DNA complex was uniquely formed with the DNA fragment containing the upstream region from the first exon of rat regucalcin gene. On the other hand, this complex was not found by using the nuclear extracts from rat brain, spleen, and heart. The nuclear proteins of these extracts, however, could specifically bind to the DNA fragment containing the first exon region of rat regucalcin gene, although Northern blot analysis did not show detectable amount of regucalcin mRNA levels in rat brain, spleen, and heart. The present study demonstrates that the existence of nuclear protein components which bind to the regucalcin gene. These identified components may be involved in the tissue-specific regulation of regucalcin gene expression.