Internal heating method of loop-mediated isothermal amplification for detection of HPV-6 DNA.

Loop-mediated isothermal amplification (LAMP) is a promising diagnostic tool for genetic amplification, which is known for its rapid process, simple operation, high amplification efficiency, and excellent sensitivity. However, most of the existing heating methods are external for completion of molecular amplification with possibility of contamination of specimens. The present research provided an internal heating method for LAMP using magnetic nanoparticles (MNPs), which is called nano-LAMP. Near-infrared light with an excitation wavelength of 808 nm was employed as the heating source; hydroxy naphthol blue (HNB) was used as an indicator to conduct methodological research. We demonstrate that the best temperature was controlled at a working power of 2 W and 4.8 µg/µL concentration of nanoparticles. The lowest limit for the detection of HPV by the nano-LAMP method is 102 copies/mL, which was confirmed by a gel electrophoresis assay. In the feasibility investigation of validated clinical samples, all 10 positive HPV-6 specimens amplified by nano-LAMP were consistent with conventional LAMP methods. Therefore, the nano-LAMP detection method using internal heating of MNPs may bring a new vision to the exploration of thermostatic detection in the future.

Circulating Tumor Cells with Stem-Like Phenotypes for Diagnosis, Prognosis, and Therapeutic Response Evaluation in Hepatocellular Carcinoma.

Background: In the present study, we assessed the clinical value of circulating tumor cells (CTC) with stem-like phenotypes for diagnosis, prognosis, and surveillance in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) by an optimized qPCR-based detection platform.Methods: Differing subsets of CTCs were investigated, and a multimarker diagnostic CTC panel was constructed in a multicenter patient study with independent validation (total n = 1,006), including healthy individuals and patients with chronic hepatitis B infection (CHB), liver cirrhosis (LC), benign hepatic lesion (BHL), and HBV-related HCC, with area under the receiver operating characteristic curve (AUC-ROC) reflecting diagnostic accuracy. The role of the CTC panel in treatment response surveillance and its prognostic significance were further investigated.Results: The AUC of the CTC panel was 0.88 in the training set [sensitivity = 72.5%, specificity = 95.0%, positive predictive value (PPV) = 92.4, negative predictive value (NPV) = 77.8] and 0.93 in the validation set (sensitivity = 82.1%, specificity = 94.2%, PPV = 89.9, NPV = 89.3). This panel performed equally well in detecting early-stage and α-fetoprotein-negative HCC, as well as differentiating HCC from CHB, LC, and BHL. The CTC load was decreased significantly after tumor resection, and patients with persistently high CTC load showed a propensity of tumor recurrence after surgery. The prognostic significance of the CTC panel in predicting tumor recurrence was further confirmed [training: HR = 2.692; 95% confidence interval (CI), 1.617-4.483; P < 0.001; and validation: HR = 3.127; 95% CI, 1.360-7.190; P = 0.007].Conclusions: Our CTC panel showed high sensitivity and specificity in HCC diagnosis and could be a real-time parameter for risk prediction and treatment monitoring, enabling early decision-making to tailor effective antitumor strategies. Clin Cancer Res; 24(9); 2203-13. ©2018 AACR.

A mammalian monothiol glutaredoxin, Grx3, is critical for cell cycle progression during embryogenesis.

Glutaredoxins (Grxs) have been shown to be critical in maintaining redox homeostasis in living cells. Recently, an emerging subgroup of Grxs with one cysteine residue in the putative active motif (monothiol Grxs) has been identified. However, the biological and physiological functions of this group of proteins have not been well characterized. Here, we characterize a mammalian monothiol Grx (Grx3, also termed TXNL2/PICOT) with high similarity to yeast ScGrx3/ScGrx4. In yeast expression assays, mammalian Grx3s were localized to the nuclei and able to rescue growth defects of grx3grx4 cells. Furthermore, Grx3 inhibited iron accumulation in yeast grx3gxr4 cells and suppressed the sensitivity of mutant cells to exogenous oxidants. In mice, Grx3 mRNA was ubiquitously expressed in developing embryos, adult tissues and organs, and was induced during oxidative stress. Mouse embryos absent of Grx3 grew smaller with morphological defects and eventually died at 12.5 days of gestation. Analysis in mouse embryonic fibroblasts revealed that Grx3(-/-) cells had impaired growth and cell cycle progression at the G(2) /M phase, whereas the DNA replication during the S phase was not affected by Grx3 deletion. Furthermore, Grx3-knockdown HeLa cells displayed a significant delay in mitotic exit and had a higher percentage of binucleated cells. Therefore, our findings suggest that the mammalian Grx3 has conserved functions in protecting cells against oxidative stress and deletion of Grx3 in mice causes early embryonic lethality which could be due to defective cell cycle progression during late mitosis.

Health compromising behaviors among Chinese adolescents: role of physical abuse, school experience, and social support.

This study examined the influence of immediate social environment on health compromising behaviors (HCB) among 6564 high school students in China. Results showed that physical abuse by parents was a major risk factor that accounted for high rates of HCB. Perceived positive school experience and social support were protective factors associated with low rates of HCB. These two protective factors also buffered the adverse influence of abuse on the practice of individual HCB. In particular, parental abuse was associated with sexual experimentation, non-fatal self-harm, and suicide behaviors only at low levels of protective factors.

Pepsinogens and pepsins from Japanese seabass (Lateolabrax japonicus).

Three pepsinogens (PG1, PG2, PG3) were highly purified from the stomach of Japanese seabass (Lateolabrax japonicus) by ammonium sulfate fractionation, DEAE-Sephacel anion exchange column chromatography and Sephacryl S-200 gel-filtration. Two dimensional polyacrylamide gel electrophoresis (2D-PAGE) analysis revealed that the molecular masses of the three PGs were 35, 37, and 34kDa, and their isoelectric points were 5.3, 5.1, and 4.7, respectively. Zymography analysis showed that the three pepsinogens had different mobilities and enzymatic activities under native conditions. Pepsinogens converted into their active form pepsins under pH 2.0 by one-step pathway or stepwise pathway. All three pepsins were completely inhibited by pepstatin A, a typical aspartic proteinase inhibitor. The N-terminal amino acid sequences of the three pepsinogens were determined to the 30th, 30th and 28th amino acid residue and those of their corresponding active form pepsins were also determined to the 19th, 18th and 20th amino acid residue, respectively. All amino acid sequences of Japanese seabass PGs revealed high identities to reported fish and mammalian pepsinogens. The effective digestion of fish and shrimp muscular proteins by pepsins indicated their physiological function in the degradation of food proteins.

Purification and characterization of pepsinogens and pepsins from the stomach of rice field eel (Monopterus albus Zuiew).

Three pepsinogens (PG1, PG2, and PG3) were highly purified from the stomach of freshwater fish rice field eel (Monopterus albus Zuiew) by ammonium sulfate fractionation and chromatographies on DEAE-Sephacel, Sephacryl S-200 HR. The molecular masses of the three purified PGs were all estimated as 36 kDa using SDS-PAGE. Two-dimensional gel electrophoresis (2D-PAGE) showed that pI values of the three PGs were 5.1, 4.8, and 4.6, respectively. All the PGs converted into corresponding pepsins quickly at pH 2.0, and their activities could be specifically inhibited by aspartic proteinase inhibitor pepstatin A. Optimum pH and temperature of the enzymes for hydrolyzing hemoglobin were 3.0-3.5 and 40-45 °C. The K (m) values of them were 1.2 × 10⁻4 M, 8.7 × 10⁻5 M, and 6.9 × 10⁻5 M, respectively. The turnover numbers (k(cat)) of them were 23.2, 24.0, and 42.6 s⁻¹. Purified pepsins were effective in the degradation of fish muscular proteins, suggesting their digestive functions physiologically.

Study on pepsinogens and pepsins from snakehead (Channa argus).

Three pepsinogens (PG1, PG2, and PG3) were highly purified from the stomach of freshwater fish snakehead (Channa argus) by ammonium sulfate fractionation, anion exchange, and gel filtration. Two-dimensional gel electrophoresis and native-PAGE analysis revealed that their molecular masses were 37, 38, and 36 kDa and their isoelectric points 4.8, 4.4, 4.0, respectively. All of the pepsinogens converted into their active form pepsins under pH 2.0 by one-step pathway or stepwise pathway. The three pepsins showed maximal activity at pH 3.0, 3.5, and 3.0 with optimum temperature at 45, 40, and 40 degrees C, respectively, using hemoglobin as substrate. All of the pepsins were completely inhibited by pepstatin A, a typical aspartic proteinase inhibitor. The N-terminal amino acid sequences of the three pepsinogens were determined to the 34th, 25th, and 28th amino acid residues, respectively. Western blot analysis of the three PGs exhibited different immunological reactions.