The relationship between longer leukocyte telomeres and dNCR in non-cardiac surgery patients: a retrospective analysis.

BACKGROUND: Cognitive decline following surgery is a common concern among elderly individuals. Leukocyte telomere length (LTL) can be assessed as a biological clock connected to an individual lifespan. However, the mechanisms causing this inference are still not fully understood. As a result of this, LTL has the potential to be useful as an aging-related biomarker for assessing delayed neurocognitive recovery (dNCR) and related diseases. METHODS: For this study, 196 individuals over 60 who were scheduled due to major non-cardiac surgical operations attended neuropsychological testing before surgery, followed by additional testing one week later. The finding of dNCR was based on a measured Z-score ≤ -1.96 on two or more separate tests. The frequency of dNCR was presented as the primary outcome of the study. Secondly, we evaluated the association between dNCR and preoperative LTL. RESULTS: Overall, 20.4% [40/196; 95% confidence interval (CI), 14.7-26.1%] of patients exhibited dNCR 1-week post-surgery. Longer LTL was identified as a predictor for the onset of early cognitive impairment resulting in postoperative cognitive decline [odds ratio (OR), 14.82; 95% CI, 4.01-54.84; P < 0.001], following adjustment of age (OR, 12.33; 95% CI, 3.29-46.24; P < 0.001). The dNCR incidence based on LTL values of these patients, the area under the receiver operating characteristic (ROC) curve was 0.79 (95% CI, 0.722-0.859; P < 0.001). At an optimal cut-off value of 0.959, LTL values offered respective specificity and sensitivity values of 64.7% and 87.5%. CONCLUSIONS: In summary, the current study revealed that the incidence of dNCR was strongly associated with prolonged LTL. Furthermore, this biomarker could help identify high-risk patients and offer insight into the pathophysiology of dNCR.

Assessment of ctDNA in CSF may be a more rapid means of assessing surgical outcomes than plasma ctDNA in glioblastoma.

We aimed to develop a high-throughput deep DNA sequencing assay of cerebrospinal fluid (CSF) to identify clinically relevant oncogenic mutations that contribute to the development of glioblastoma (GBM) and serve as biomarkers to predict patients' responses to surgery. For this purpose, we recruited five patients diagnosed with highly suspicious GBM according to preoperative magnet resonance imaging. Subsequently, patients were histologically diagnosed with GBM. CSF was obtained through routine lumbar puncture, and plasma from peripheral blood was collected before surgery and 7 days after. Fresh tumor samples were collected using routine surgical procedures. Targeted deep sequencing was used to characterize the genomic landscape and identify mutational profile that differed between pre-surgical and post-surgical samples. Sequence analysis was designed to detect protein-coding exons, exon-intron boundaries, and the untranslated regions of 50 genes associated with cancers of the central nervous system. Circulating tumor DNAs (ctDNAs) were prepared from the CSF and plasma from peripheral blood. For comparison, DNA was isolated from fresh tumor tissues. Non-silent coding variants were detected in CSF and plasma ctDNAs, and the overall minor allele frequency (MAF) of the former corresponded to an earlier disease stage compared with that of plasma when the tumor burden was released (surgical removal). Gene mutation loads of GBMs significantly correlated with overall survival (OS, days) (Pearson correlation = -0.95, P = 0.01). We conclude that CSF ctDNAs better reflected the sequential mutational changes of driver genes compared with those of plasma ctDNAs. Deep sequencing of the CSF of patients with GBM may therefore serve as an alternative clinical assay to improve patients' outcomes.

Preoperative Salivary Cortisol AM/PM Ratio Predicts Early Postoperative Cognitive Dysfunction After Noncardiac Surgery in Elderly Patients.

BACKGROUND: The diagnosis of postoperative cognitive dysfunction (POCD) requires complicated neuropsychological testing and is often delayed. Possible biomarkers for early detection or prediction are essential for the prevention and treatment of POCD. Preoperative screening of salivary cortisol levels may help to identify patients at elevated risk for POCD. METHODS: One hundred twenty patients >60 years of age and undergoing major noncardiac surgery underwent neuropsychological testing 1 day before and 1 week after surgery. Saliva samples were collected in the morning and the evening 1 day before surgery. POCD was defined as a Z-score of ≤-1.96 on at least 2 different tests. The primary outcome was the presence of POCD. The primary objective of this study was to assess the relationship between the ratio of AM (morning) to PM (evening) salivary cortisol levels and the presence of POCD. The secondary objective was to assess the relationship between POCD and salivary cortisol absolute values in the morning or in the evening. RESULTS: POCD was observed in 17.02% (16 of 94; 95% confidence interval [CI], 9.28%-24.76%) of patients 1 week after the operation. A higher preoperative AM/PM salivary cortisol ratio predicted early POCD onset (odds ratio [OR], 1.56; 95% CI, 1.20-2.02; P = .001), even after adjusting for the Mini-Mental Sate Examination score (odds ratio, 1.55; 95% CI, 1.19-2.02; P = .001). The area under the receiver operating characteristic curve for the salivary cortisol AM/PM ratio in individuals with POCD was 0.72 (95% CI, 0.56-0.88; P = .006). The optimal cutoff value was 5.69, with a sensitivity of 50% and specificity of 91%. CONCLUSIONS: The preoperative salivary cortisol AM/PM ratio was significantly associated with the presence of early POCD. This biomarker may have potential utility for screening patients for an increased risk and also for further elucidating the etiology of POCD.

Activating mutations in PTPN3 promote cholangiocarcinoma cell proliferation and migration and are associated with tumor recurrence in patients.

BACKGROUND & AIMS: The pathogenesis of intrahepatic cholangiocarcinoma (ICC), the second most common hepatic cancer, is poorly understood, and the incidence of ICC is increasing worldwide. We searched for mutations in human ICC tumor samples and investigated how they affect ICC cell function. METHODS: We performed whole exome sequencing of 7 pairs of ICC tumors and their surrounding nontumor tissues to detect somatic alterations. We then screened 124 pairs of ICC and nontumor samples for these mutations, including 7 exomes. We compared mutations in PTPN3 with tumor recurrence in 124 patients and PTPN3 expression levels with recurrence in 322 patients (the combination of both in 86 patients). The functional effects of PTPN3 variations were determined by RNA interference and transgenic expression in cholangiocarcinoma cell lines (RBE, HCCC-9810, and Huh28). RESULTS: Based on exome sequencing, pathways that regulate protein phosphorylation were among the most frequently altered in ICC samples and genes encoding protein tyrosine phosphatases (PTPs) were among the most frequently mutated. We identified mutations in 9 genes encoding PTPs in 4 of 7 ICC exomes. In the prevalence screen of 124 paired samples, 51.6% of ICCs contained somatic mutations in at least 1 of 9 PTP genes; 41.1% had mutations in PTPN3. Transgenic expression of PTPN3 in cell lines increased cell proliferation, colony formation, and migration. PTPN3(L232R) and PTPN3(L384H), which were frequently detected in ICC samples, were found to be gain-of-function mutations; their expression in cell lines further increased cell proliferation, colony formation, and migration. ICC-associated variants of PTPN3 altered phosphatase activity. Patients whose tumors contained activating mutations or higher levels of PTPN3 protein than nontumor tissues had higher rates of disease recurrence than patients whose tumors did not have these characteristics. CONCLUSIONS: Using whole exome sequencing of ICC samples from patients, we found that more than 40% contain somatic mutations in PTPN3. Activating mutations in and high expression levels of PTPN3 were associated with tumor recurrence.

Efficacy of femoral periarterial block in preventing thigh tourniquet pain: a randomized controlled trial.

BACKGROUND: Tourniquet pain, described as a dull, tight, poorly localized aching sensation, is common in conscious patients. Although various pain-reduction methods have been implemented, none are completely effective. Femoral periarterial block (FAB) has been shown to attenuate tourniquet-induced hypertension in patients undergoing general anesthesia. We aimed to test the feasibility of FAB in inhibiting thigh tourniquet pain in orthopedic patients under conscious sedation. METHODS: Forty-two patients (aged 18-64 years and ASA I-II) scheduled for below-knee orthopedic surgeries with an anticipated tourniquet duration of more than 40 min were recruited and received FAB (Group 1) or not (Group 2). The primary outcome was the occurrence of tourniquet pain. The onset time and severity of the tourniquet pain were recorded. Total doses of sedatives and analgesics administered intraoperatively and hemodynamic changes were documented. The occurrence of local anesthetic systemic toxicity was recorded. RESULTS: Kaplan-Meier time-to-event curves indicated an improved tourniquet tolerance and delayed pain onset. Tourniquet pain occurrence was lower in Group 1 than in Group 2 (30% vs. 95.5%, P=0.02). Tourniquet pain onset was delayed in Group 1 (80[67,84] min vs. 58[51.5,60] min, P<0.01). Fewer patients in Group 1 experienced severe pain (3(15%) vs. 18(81.8%), P<0.01), and less hemodynamic changes (2(10%) vs. 12(54.5%), P<0.01). Local anesthetic systemic toxicity was absent. CONCLUSIONS: FAB, applied with regional anesthesia in patients undergoing below-knee orthopedic surgeries, could reduce thigh tourniquet pain, stabilize blood pressure and heart rate, and prolong tourniquet duration.

Microchip-based immunoassays with application of silicon dioxide nanoparticle film.

Highly sensitive detection of proteins offers the possibility of early and rapid diagnosis of various diseases. Microchip-based immunoassay integrates the benefits from both immunoassays (high specificity of target sample) and microfluidics (fast analysis and low sample consumption). However, direct capture of proteins on bare microchannel surface suffers from low sensitivity due to the low capacity of microsystem. In this study, we demonstrated a microchip-based heterogeneous immunoassay using functionalized SiO(2) nanoparticles which were covalently assembled on the surface of microchannels via a liquid-phase deposition technique. The formation of covalent bonds between SiO(2) nanoparticles and polydimethylsiloxane substrate offered sufficient stability of the microfluidic surface, and furthermore, substantially enhanced the protein capturing capability, mainly due to the increased surface-area-to-volume ratio. IgG antigen and FITC-labeled anti-IgG antibody conjugates were adopted to compare protein-enrichment effect, and the fluorescence signals were increased by ~75-fold after introduction of functionalized SiO(2) nanoparticles film. Finally, a proof-of-concept experiment was performed by highly efficient capture and detection of inactivated H1N1 influenza virus using a microfluidic chip comprising highly ordered SiO(2) nanoparticles coated micropillars array. The detection limit of H1N1 virus antigen was 0.5 ng mL(-1), with a linear range from 20 to 1,000 ng mL(-1) and mean coefficient of variance of 4.71%.

Identification of the popliteal sciatic nerve through the above-knee lateral approach provides superior echogenicity and ultrasound visibility: a patient volunteer trial.

BACKGROUND: Distinguishing light-echoed nerves from surrounding structures is challenging but may be important in nerve block administration. We evaluated the effect of patient characteristics on the echogenicity or visibility of the popliteal sciatic nerve (PSN). METHODS: This study included adult patients who presented to the operating room as volunteers. The primary outcome was the success rate of nerve identification by ultrasound using different PSN access paths. The secondary outcome included the PSN visibility score (VIS), scan time, and PSN depth. Logistic regression analysis was used to identify factors associated with the PSN identification success rate. The Body Mass Index (BMI) proximal-based cut-off was used to compare the PSN identification success rate through different access paths. RESULTS: The PSN was successfully identified in 89.7% of the volunteers. The access paths (P<0.01) and BMI (P=0.01) were identified as independent predictors of successful PSN identification. A higher PSN identification success rate (P=0.01), a higher VIS (P<0.01), a more superficial PSN depth (P<0.01), and a shorter scan time (P<0.01) were observed in the above-knee lateral approach. Among volunteers with BMI≥26.77 kg/m2, the PSN identification success rate through the above-knee lateral approach was significantly higher (P<0.01), and PSN depth was shallower (P<0.01) than through the medial approach. CONCLUSIONS: The ultrasound-guided above-knee lateral approach for PSN block improved the PSN identification success rate, ensured a more superficial nerve location, and provided a clearer image.

Association of acute normovolemic hemodilution with decreased length of hospital stay in rhesus-negative patients undergoing major cancer surgeries: a retrospective study.

BACKGROUND: Shortages of allogeneic blood supplies for rhesus (Rh)-negative patients who are scheduled for major cancer surgeries may cause delays in surgical procedure, resulting in a prolonged length of hospital stay (LOHS). This study investigated the relationship of acute normovolemic hemodilution (ANH) with LOHS in this patient population. METHODS: Rh-negative patients who underwent major cancer surgeries between January 2015 and April 2020 were included in this retrospective study. The primary outcome was LOHS. The secondary outcomes were length of preoperative stay (LOPS), perioperative laboratory data and allogeneic blood transfusion (ABT), and postoperative adverse events. Furthermore, relationships between these perioperative variables and LOHS were examined by both univariate analyses and multiple linear regression analysis. RESULTS: Seventy patients were divided into ANH (n=30) or Control (n=40) group. The two groups were well-matched for baseline data. LOHS, LOPS, perioperative ABT amount, and the overall rate of postoperative adverse events were all significantly lower in the ANH group (P=0.004, P=0.009, P<0.001, P=0.023, respectively). In the ANH group, levels of hemoglobin and hematocrit decreased on postoperative day 1 (P=0.023, P=0.012, respectively). Univariate analyses revealed significant association between LOHS and the following perioperative variables: ANH, body mass index, types of surgery, intraoperative colloids infusion, and perioperative ABT. Multiple linear regression analysis with correction for diagnosis identified ANH, intraoperative colloids infusion, and perioperative ABT as independent predictors. CONCLUSIONS: ANH was associated with the decreased LOHS in Rh-negative patients undergoing major cancer surgeries.

Association between preoperative serum homocysteine and delayed neurocognitive recovery after non-cardiac surgery in elderly patients: a prospective observational study.

BACKGROUND: Homocysteine, folate, and vitamin B12 involved in 1-carbon metabolism are associated with cognitive disorders. We sought to investigate the relationships between these factors and delayed neurocognitive recovery (dNCR) after non-cardiac surgery. METHODS: This was a prospective observational study of patients (n = 175) who were ≥ 60 years of age undergoing non-cardiac surgery. Patients were evaluated preoperatively and for 1 week postoperatively by using neuropsychological tests and were divided into dNCR or non-dNCR groups according to a Z-score ≤ - 1.96 on at least two of the tests. The relationship between the occurrence of dNCR and preoperative levels of homocysteine, folate, and vitamin B12 was analyzed. Univariate and multivariable logistic regression analyses were conducted to identify factors associated with dNCR. RESULTS: Delayed neurocognitive recovery was observed in 36 of 175 patients (20.6%; 95% confidence interval [CI], 14.5-26.6%) 1 week postoperatively. Patients who developed dNCR had significantly higher median [interquartile range (IQR)] homocysteine concentrations (12.8 [10.9,14.4] µmol/L vs 10.6 [8.6,14.7] µmol/L; P = 0.02) and lower folate concentrations (5.3 [4.2,7.3] ng/mL vs 6.9 [5.3,9.5] ng/mL; P = 0.01) than those without dNCR. Compared to the lowest tertile, the highest homocysteine tertile predicted dNCR onset (odds ratio [OR], 3.9; 95% CI, 1. 3 to 11.6; P = 0.02), even after adjusting for age, sex, education, and baseline Mini Mental State Examination. CONCLUSIONS: Elderly patients with high homocysteine levels who underwent general anesthesia for non-cardiac surgery have an increased risk of dNCR. This knowledge could potentially assist in the development of preventative and/or therapeutic measures. TRIAL REGISTRATION: NCT03084393 ( https://www.clinicaltrials.gov ).

Efficacy and safety of ultrasound-guided above-knee lateral approach for popliteal sciatic nerve block in surgeries below the knee: a randomized controlled trial.

BACKGROUND: Ultrasound guidance has become a standard method for detection of nerve structures in regional anesthesia. During ultrasound-guided blockade, to identify anatomical structures is crucial but can be challenging. In clinical practice, we find a wide difference in the visibility score of the sciatic nerve (SN) through different approaches. This study aimed to compare SNB through the anterior and above-knee lateral approach in terms of identification ease, performance efficacy, and safety. METHODS: Patients scheduled for below-knee surgery were randomized to either receive SNB using the above-knee lateral approach (Group L, n=27) or the anterior approach (Group A, n=26). The primary outcome was the visibility score of SN. Secondary outcomes included the time taken to identify the SN, nerve depth, success rate of SN identification, number of needle passes, time to elicit foot flexion, needle depth, and occurrence of SNB complications. Additionally, the sensory block onset and analgesia duration were assessed. RESULTS: We included 53 adult patients. Compared with Group A, Group L showed a higher SN visibility score [3.25 (3.17, 3.67) vs. 2.50 (1.86, 2.68), P<0.001]. The scan time was significantly shorter in Group L [8.70 (6.01) s vs. 31.54 (11.87) s, P<0.001]. The depth of the SN was 3.20 (0.56) cm in Group L and 5.53 (0.84) cm in Group A (P<0.001), and the needle insertion depth was 7.15 (0.90) cm in group L and 8.32 (1.13) cm in Group A (P<0.001). The number of needle passes was less in Group L, as well as the time to elicit foot flexion, and the time taken to perform the SN block (all P<0.001). The success rate of SN identification was non-significantly higher in Group L. There was no significant between-group difference in the onset of sensory block, as well as postoperative analgesia duration. None of the approaches involved acute systemic toxicity and hematoma occurrence. CONCLUSIONS: Based on the visibility score, the above-knee lateral approach allowed easy SN identification and safe SNB. Using the ultrasound-guided above-knee lateral approach for SNB in below-knee surgeries could be a reliable choice.

Humidity Sensors Realized via Negative Photoconductivity Effect in Nanodiamonds.

Herein, the negative photoconductivity (NPC) effect has been observed in nanodiamonds (NDs) for the first time, and with illumination under a 660 nm laser lamp, the conductivity of the NDs decreases significantly. The NPC effect has been attributed to the trapping of carriers by the absorbed water molecules on the ND surfaces. A humidity sensor has been constructed based on the NPC effect of the NDs, and the sensitivity of the sensor can reach 106%, which is the highest value ever reported for carbon-based humidity sensors.

Inhibition of K-Ras4B-plasma membrane association with a membrane microdomain-targeting peptide.

The association of K-Ras4B protein with plasma membrane (PM) is required for its signaling activity. Thus, direct inhibition of K-Ras4B-PM interaction could be a potential anti-Ras therapeutic strategy. However, it remains challenging to modulate such protein-PM interaction. Based on Ras isoform-specific PM microdomain localization patterns, we have developed a potent and isoform-selective peptide inhibitor, Memrasin, for detachment of K-Ras4B from the PM. Memrasin is one of the first direct inhibitors of K-Ras4B-PM interaction, and consists of a membrane ld region-binding sequence derived from the C-terminal region of K-Ras4B and an endosome-escape enhancing motif that can aggregate on membrane. It forms peptide-enriched domains in the ld region, abrogates the tethering of K-Ras4B to the PM and accordingly impairs Ras signaling activity, thereby efficiently decreasing the viability of several human lung cancer cells in a dose-responsive and K-Ras dependent manner. Memrasin provides a useful tool for exploring the biological function of K-Ras4B on or off the PM and a potential starting point for further development into anti-Ras therapeutics.

Hydrogen-bonded chains in 2,2,2-trichloro-N,N'-bis(4-methoxyphenyl)ethane-1,1-diamine and a three-dimensional hydrogen-bonded framework in 2,2,2-trichloro-N,N'-bis(4-chlorophenyl)ethane-1,1-diamine.

In 2,2,2-trichloro-N,N'-bis(4-methoxyphenyl)ethane-1,1-diamine, C(16)H(17)Cl(3)N(2)O(2), molecules are linked into helical chains by N-H...O hydrogen bonds. Molecules of 2,2,2-trichloro-N,N'-bis(4-chlorophenyl)ethane-1,1-diamine, C(14)H(11)Cl(5)N(2), are connected into a three-dimensional framework by two independent Cl...Cl interactions and one C-H...Cl hydrogen bond.

Diagnostic value of multislice computerized tomography angiography for aortic dissection: A comparison with DSA.

The aim of the present study was to compare multislice computed tomography angiography (MSCTA) and digital subtraction angiography (DSA) in the diagnosis of aortic dissection. In total, 49 patients with aortic lesions received enhanced computed tomography scanning, and three-dimensional (3D) images were reconstructed by volume rendering (VR), maximum intensity projection (MIP), multiplanar reformation (MPR) and curved planar reconstruction (CPR). The display rate of the entry tear site, intimal flap, true and false lumen from each reconstruction method was calculated. For 30 patients with DeBakey type III aortic dissection, the entry tear site and size of the first intimal flap, aortic maximum diameter at the orifice of left subclavian artery (LSCA), distance between the first entry tear site and the orifice of LSCA, and maximum diameter of aortic true and false lumens were measured prior to implantation of endovascular covered stent-grafts. Data obtained by MSCTA and DSA were then compared. For the entry tear site, MPR, CPR and VR provided a display rate of 95.92, 95.92 and 18.37%, respectively, and the display rate of the intimal flap was 100% in the three methods. MIP did not directly display the entry tear site and intimal flap. For true and false lumens, MPR, CPR, and VR showed a display rate of 100%, while MIP only provided a display rate of 67.35%. When MSCTA was compared with DSA, there was a significant difference in the display of entry site number and position (P<0.05), whereas no significant difference was shown in the measurement of aortic maximum diameter at the orifice of LSCA and the maximum diameter of true and false lumens (P>0.05). In conclusion, among the 3D post-processing reconstruction methods of MSCTA used, MPR and CPR were optimal, followed by VR, and MIP. MSCTA may be the preferable imaging method to diagnose aortic dissection and evaluate treatment of endovascular-covered stent-grafting, preoperatively.

Programmed death ligand 1 as an indicator of pre-existing adaptive immune responses in human hepatocellular carcinoma.

It is well known that the aberrant expression of programmed death ligand 1 (PD-L1) on tumor cells impairs antitumor immunity. To date, in hepatocellular carcinoma (HCC), the relationship between PD-L1 expression and host-tumor immunity is not well defined. Here, the expression levels of PD-L1 and CD8(+) T cell infiltration were analyzed by immunohistochemistry (IHC) in formalin fixed paraffin embedded (FFPE) specimens from 167 HCC patients undergoing resection. A significant positive association was found between PD-L1 expression and the presence of CD8(+) T cell (p < 0.0001). Moreover, constitutive PD-L1 protein expression was not detected by western blot in HepG2, Hep3B, and 7402 HCC cancer cell lines; but co-cultured these cell lines with INFγ, a cytokine produced by activated CD8(+) T cells, remarkably upregulated PD-L1 expression. In fresh frozen HCC specimens, INFγ was found to be significantly correlated with PD-L1 and CD8(+) gene expression, as evaluated by quantitative reverse transcriptase polymerase chain reaction (RT-PCR). These findings indicate that increased PD-L1 level may represent an adaptive immune resistance mechanism exerted by tumor cells in response to endogenous antitumor activity. Both increased intratumoral PD-L1 and CD8(+) were significantly associated with superior DFS (CD8(+): p = 0.03; PD-L1: p = 0.023) and OS (CD8(+): p = 0.001 and PD-L1: p = 0.059), but PD-L1 expression was not independently prognostic. In conclusions, PD-L1 upregulation is mainly induced by activated CD8(+) cytotoxic T cells pre-existing in HCC milieu rather than be constitutively expressed by the tumor cells, and it is a favorable prognostic factor for HCC.

Anisotropic cell-to-cell spread of vaccinia virus on microgrooved substrate.

Cell-to-cell spread of virus is a comprehensive process with involvement of cellular actin cytoskeleton and substrate topography can affect the arrangement of cytoskeleton via contact guidance, yet interaction among virus, cytoskeleton and substrate topography is still unknown. To investigate the virus-cell-substrate interaction, we designed a microgrooved poly(dimethyl siloxane) (PDMS) substrate for the study of vaccinia virus (VACV) cell-to-cell spread and the remodeling of cellular actin cytoskeleton in viral infection process. Interestingly, VACV-induced plaques on microgrooved substrate were elliptical instead of circular plaques on smooth substrate, suggesting an anisotropic cell-to-cell spread of VACV. The spread rate was faster in the direction parallel to microgroove and slower in the direction perpendicular to microgroove than that on smooth substrate. Host cells cultured on microgrooved surface showed significant alignment and elongation in the axis parallel to microgrooves. Cell elongation is one reason for anisotropic spread but could not totally explain the phenomenon. Actin fibers in infected cells maintained alignment and VACV-induced actin tails tipped with virions were oriented along the direction parallel to microgroove. These results suggested that substrate topography can affect infected cells and these effects will guide the spread of virus via orientation of actin cytoskeleton. This work opens a window for understanding virus response to substrate topography, and has potential implications on revealing virus-cell-substrate interactions in vivo.

GSTP1 arrests bladder cancer T24 cells in G0/G1 phase and up-regulates p21 expression.

OBJECTIVE: GSTP1 over-expression was introduced into human bladder cancer T24 cells via the lentivirus system. The influence of GSTP1 on the proliferation and cell cycle of T24 cells as well as the potential mechanisms was investigated. METHODS: The lentiviral vector GSTP1-pWPXL was constructed and transfected into T24 cells in the presence of Lipofectamine 2000. CCK8 assay and colony formation test were performed to explore the impact of GSTP1 on the proliferation of T24 cells. Ollowing PI staining, flow cytometry was done to detect the proportion of T24 cells in different phases. Western blot assay was conducted to detect the protein p21 expression. RESULTS: When compared with control group, T24 cells with GSTP1 over-expression showed significant reduction in cell proliferation (P < 0.01) and they were arrested in G0/G1 phase. Western blot assay indicated that the p21 protein expression in T24 cells with GSTP1 over-expression was significantly higher than that in control group. CONCLUSION: GSTP1 may inhibit the proliferation of T24 cells and arrest these cells in G0/G1 phase, which may be ascribed to the up-regulated expression of p21.

Utilization of stem cells in alginate for nucleus pulposus tissue engineering.

In a general view of anatomy, intervertebral disc is composed of three parts: annulus fibrosus (AF), nucleus pulposus (NP), and cartilage endplate (CEP). Recently, several types of stem cells were successfully isolated from these corresponding regions, but up to now, no research was performed about which kind of stem cells is the most efficient candidate for NP tissue engineering or for stem cell-based disc regeneration therapy. In this study, we compared the regenerative potentials of the above-mentioned three kinds of disc-derived stem cells with that of the classic bone marrow (BM)-mesenchymal stem cells (MSCs) in a rabbit disc degeneration model. By magnetic resonance imaging (MRI), X-ray, histology, etc. evaluations, we found that cartilage endplate-derived stem cells (CESCs) showed superior capacity compared with the annulus fibrosus-derived stem cells (AFSCs), nucleus pulposus-derived stem cells (NPSCs), and BM-MSCs (p<0.05); additionally, when comparing the CESC group with the normal control group, there existed no statistical difference in X-ray (p>0.05). Those results demonstrated that the CESC-seeded alginate construct performed the most powerful ability for NP regeneration, while AFSCs showed the most inferior potency, NPSCs and BM-MSCs had similar regenerative capacity and located in the middle. All in all, our study showed that CESCs might act as an efficient seed cell source for NP tissue engineering, which paved a new way for the biological solution of disc degeneration diseases.

A microfluidic platform for real-time and in situ monitoring of virus infection process.

Microfluidic chip is a promising platform for studying virus behaviors at the cell level. However, only a few chip-based studies on virus infection have been reported. Here, a three-layer microfluidic chip with low shear stress was designed to monitor the infection process of a recombinant Pseudorabies virus (GFP-PrV) in real time and in situ, which could express green fluorescent protein during the genome replication. The infection and proliferation characteristics of GFP-PrV were measured by monitoring the fluorescence intensity of GFP and determining the one-step growth curve. It was found that the infection behaviors of GFP-PrV in the host cells could hardly be influenced by the microenvironment in the microfluidic chip. Furthermore, the results of drug inhibition assays on the microfluidic chip with a tree-like concentration gradient generator showed that one of the infection pathways of GFP-PrV in the host cells was microtubule-dependent. This work established a promising microfluidic platform for the research on virus infection.