Application of MFI-5 in severe complications and unfavorable outcomes after radical resection of colorectal cancer.

BACKGROUND: Frailty is considered a characteristic manifestation of physiological decline in multiple organ systems, which significantly increases the vulnerability of elderly individuals with colorectal cancer (CRC) and is associated with a poor prognosis. While studies have demonstrated that the 11-factor Modified Frailty Index (mFI-11) can effectively predict adverse outcomes following radical resection of CRC, there is a lack of research on the applicability of the 5-factor Modified Frailty Index (mFI-5) within this patient population. METHODS: In this retrospective analysis, we examined a cohort of CRC patients aged 65 years and above who had undergone radical resection. For each patient, we calculated their mFI-5 score, considering a score of ≥ 2 as an indication of frailty. We conducted univariate and multivariate analyses to assess the association between the mFI-5 and adverse outcomes as well as postoperative complications. RESULTS: Patients with an mFI-5 score ≥ 2 exhibited a significantly higher incidence of serious postoperative complications (53% vs. 30%; P = 0.001) and experienced a longer hospital stay [19.00 (15.00-24.50) vs. 17.00 (14.00-20.00); P < 0.05]. Notably, an mFI-5 score greater than 2 emerged as an independent risk factor for severe postoperative complications (odds ratio: 2.297; 95% confidence interval: 1.216 to 4.339; P = 0.01). Furthermore, the mFI-5 score displayed predictive capabilities for severe postoperative complications with an area under the receiver operating characteristic (ROC) curve of 0.629 (95% confidence interval: 0.551 to 0.707; P < 0.05). CONCLUSION: The mFI-5 demonstrates a high level of sensitivity in predicting serious complications, prolonged hospital stays, and mortality following radical resection of colorectal carcinoma. As a practical clinical assessment tool, the mFI-5 enables the identification of high-risk patients and facilitates preoperative optimization.

Rapid identification and quantitation of the viable cells of Lactobacillus casei in fermented dairy products using an aptamer-based strategy powered by a novel cell-SELEX protocol.

An aptamer-based strategy was developed for qualitative and quantitative analysis of viable Lactobacillus casei in dairy products. Three highly specific aptamers for L. casei were obtained using systematic evolution of ligands by exponential enrichment protocol using the whole bacterium cell as the target (cell-SELEX) facilitated by polyethyleneglycol and chitosan modified graphene oxide and complementary ring-mediated rolling circle amplification. Two aptamers, one for separating and enriching the L. casei cells and the other for generating fluorescence signals, were employed to develop an aptamer-based strategy, which was demonstrated for the selective detection of L. casei in commercial dairy drinks, with a dynamic range of 105 to 109 cfu/mL. Viable and nonviable L. casei cells could be discriminated based on the significant difference in fluorescence intensity. This established strategy is of high selectivity and sensitivity, and can be used for rapid analysis of viable L. casei in quality control and food surveillance areas.

Chirality transmission in macromolecular domains.

Chiral communications exist in secondary structures of foldamers and copolymers via a network of noncovalent interactions within effective intermolecular force (IMF) range. It is not known whether long-range chiral communication exists between macromolecular tertiary structures such as peptide coiled-coils beyond the IMF distance. Harnessing the high sensitivity of single-molecule force spectroscopy, we investigate the chiral interaction between covalently linked DNA duplexes and peptide coiled-coils by evaluating the binding of a diastereomeric pair of three DNA-peptide conjugates. We find that right-handed DNA triple helices well accommodate peptide triple coiled-coils of the same handedness, but not with the left-handed coiled-coil stereoisomers. This chiral communication is effective in a range (<4.5 nm) far beyond canonical IMF distance. Small-angle X-ray scattering and molecular dynamics simulation indicate that the interdomain linkers are tightly packed via hydrophobic interactions, which likely sustains the chirality transmission between DNA and peptide domains. Our findings establish that long-range chiral transmission occurs in tertiary macromolecular domains, explaining the presence of homochiral pairing of superhelices in proteins.

Visualized Detection of Vibrio parahaemolyticus in Food Samples Using Dual-Functional Aptamers and Cut-Assisted Rolling Circle Amplification.

A biosensor using two aptamers (Dual-Apt) and cut-assisted rolling circle amplification (CA-RCA) for rapid and visualized detection of Vibrio parahaemolyticus was established. The anchoring aptamer (A-Apt) that specifically binds to the surface of V. parahaemolyticus was applied to separate and enrich the bacterium from the food matrix with the help of streptavidin magnetic beads. While the detecting aptamer (D-Apt), binding on the different sites of the cell surface, was used as a signal reporter. CA-RCA with an enhanced amplification rate was fabricated here to amplify the D-Apt to produce the monomeric G4 sequence that catalyzes the oxidation of ABTS2-, resulting in the coloration visible to the naked eye. Under optimal conditions, as low as 10 colony-forming units (CFU)/mL (g) of V. parahaemolyticus can be visibly detected in real food samples. Free from DNA extraction, visualized signal output and no need for expensive instruments enable Dual-Apt and CA-RCA to be a promising strategy for on-spot rapid detection.

Selection of highly specific aptamers to Vibrio parahaemolyticus using cell-SELEX powered by functionalized graphene oxide and rolling circle amplification.

Cell-SELEX is a powerful tool to screen aptamers binding to living cellular organisms such as bacteria, fungi and even oncocytes. Here, we developed an advanced cell-SELEX strategy featuring functionalized graphene oxide (GO) and isothermal rolling circle amplification (RCA) to select aptamers against a prevailing foodborne pathogen, Vibrio parahaemolyticus. Polyethyleneglycol (PEG) and chitosan (CTS) were grafted onto the sheet-like GO molecules to synthesize a PC-GO material. TEM and FT-IR characterization demonstrated that the PC-GO composites were near-nanometric scale and tethered with PEG and CTS moieties, a property that significantly improved its solubility in biological buffer solutions used in cell-SELEX process. PC-GO could bind with ssDNAs with lower affinities to target cells, therefore the selection efficiency is greatly enhanced. The cell-binding aptamer candidates (CACs) were amplified by 107 fold using complementary ring mediated (CRM-RCA), a created amplification method that generate single-stranded products, which could be directly used in the next round selection. As fueled by PC-GO and CRM-RCA, four highly specific aptamers with lowest Kd value of 10.3 ±â€¯2.5 nM were obtained. Flow cytometry analysis showed that all the four aptamers exhibited more than 75% binding affinity to V. parahaemolyticus than to other foodborne bacteria (less than 18%). Simple procedure, high efficiency, and free from expensive thermal cycler (required by PCR amplification) will enable the established strategy to find its applications in aptamer selecting against fungi, stem and cancerous cells as well.

A novel isothermal method using rolling circle reverse transcription for accurate amplification of small RNA sequences.

RNA amplification has extensive applications on biochemistry and its related fields. Here, we present an isothermal strategy named rolling circle reverse transcription-mediated RNA amplification (RCRT-MRA) to amplify small RNAs with accurate length and sequence. The target RNA and complementary DNA were circularized to serve as amplicons replicated via the rolling circle mechanism. The transcription product consisting of tandemly repeated RNA units, was monomerized by site-specific cleavage to generate amplified RNA with authentic length and sequence. T4 DNA ligase was chosen to circularize RNA template for its high efficiency and low cost. SuperScript IV reverse transcriptase was found to be able to catalyze the RCRT reaction on the circular RNA template, and the reaction efficiency was enhanced by adding the nicking enzyme, Nb.BbvCI to the RCRT system. E. Coli RNA polymerase, instead of the commonly used T7 RNA polymerase, was applied to synthesize long-strand RNA product for its high universality and processivity. Under the optimized conditions, small RNAs can be precisely amplified by 105∼6 folds. The fidelity of the established method was demonstrated by the accordance of the sequencing result and the initial RNA sequences. Free from expensive thermal cycler (necessary for RT-PCR-based amplification), precise replication of the initial RNA and high fidelity will enable the established strategy to be applied in RNA-seq, mRNA profiling, microarray analysis and RNA-based SELEX as well.