Long-Term Administration of Nicotinamide Mononucleotide Mitigates High-fat-diet-induced Physiological Decline in aging mice.

BACKGROUND: NAD+ level declines with age and boosting it can improve multi-organ functions and lifespan. OBJECTIVE: NMN (Nicotinamide mononucleotide), a natural NAD+ （Nicotinamide adenine dinucleotide）precursor with the ability to enhance NAD+ biosynthesis. Numerous studies have shown that a high-fat diet can accelerate the process of aging and many diseases. We hypothesized that long-term administration of NMN could exert protective effects on adipose, muscle, and kidney tissues in mice on a high-fat diet act by affecting the autophagic pathway. METHODS: Mice at 14 months of age were fed a high-fat diet and NMN was added to their drinking water at a dose of 400 mg/kg for 7 months. The locomotor ability of the mice was assessed by behavioral experiments such as grip test, wire hang test, rotarod, and beam-walking test. At the end of the behavioral experiments, the pathological changes of each peripheral organ and the expression of autophagy-related proteins as well as the markers of the senescence and inflammaging were analyzed by pathological staining, immunohistochemical staining and western blotting, respectively. RESULTS: We found that NMN supplementation increased NAD+ levels and ultimately attenuated age- and diet-related physiological decline in mice. NMN inhibited high-fat-diet-induced obesity, promoted physical activity, improved glucose and lipid metabolism, improved skeletal muscle function and renal damage as well as mitigated the senescence and inflammaging as demonstrated by p16, IL-1ß and TNF-α levels. In addition, the present study further emphasizes the potential mechanisms underlying the bidirectional relationship between NAD+ and autophagy. We detected changes in autophagy levels in various tissue organs, and NMN may play a protective role by inhibiting excessive autophagy induced by high-fat diet. CONCLUSION: Our findings demonstrated that NMN administration attenuated high fat diet-induced metabolic disorders and physiological decline in aging mice.

Optical control of protein delivery and partitioning in the nucleolus.

The nucleolus is a subnuclear membraneless compartment intimately involved in ribosomal RNA synthesis, ribosome biogenesis and stress response. Multiple optogenetic devices have been developed to manipulate nuclear protein import and export, but molecular tools tailored for remote control over selective targeting or partitioning of cargo proteins into subnuclear compartments capable of phase separation are still limited. Here, we report a set of single-component photoinducible nucleolus-targeting tools, designated pNUTs, to enable rapid and reversible nucleoplasm-to-nucleolus shuttling, with the half-lives ranging from milliseconds to minutes. pNUTs allow both global protein infiltration into nucleoli and local delivery of cargoes into the outermost layer of the nucleolus, the granular component. When coupled with the amyotrophic lateral sclerosis (ALS)-associated C9ORF72 proline/arginine-rich dipeptide repeats, pNUTs allow us to photomanipulate poly-proline-arginine nucleolar localization, perturb nucleolar protein nucleophosmin 1 and suppress nascent protein synthesis. pNUTs thus expand the optogenetic toolbox by permitting light-controllable interrogation of nucleolar functions and precise induction of ALS-associated toxicity in cellular models.

Impact of prognostic nutritional index change on prognosis after colorectal cancer surgery under propofol or sevoflurane anesthesia.

BACKGROUND: The alteration of the prognostic nutritional index (PNI) or the utilization of distinct anesthesia strategies has been linked to the prognosis of various cancer types, but the existing evidence is limited and inconclusive, particularly for colorectal cancer (CRC). Our objective was to evaluate the association between PNI change and progression free survival (PFS) and overall survival (OS) in patients treated with CRC surgery after propofol-based or sevoflurane-based anesthesia. METHODS: We conducted a retrospective analysis of 414 patients with CRC who underwent surgical resection. Among them, 165 patients received propofol-based total intravenous anesthesia (TIVA-P), while 249 patients received sevoflurane-based inhalation anesthesia (IA-S). The PNI change (ΔPNI) was calculated by subtracting the pre-surgery PNI from the post-surgery PNI, and patients were categorized into high (≥ -2.25) and low (< -2.25) ΔPNI groups. Univariate and multivariate analyses were employed to evaluate the effects of the two anesthesia methods, ΔPNI, and their potential interaction on PFS and OS. RESULTS: The median duration of follow-up was 35.9 months (interquartile range: 18-60 months). The five-year OS rates were 63.0% in the TIVA-P group and 59.8% in the IA-S group (hazard ratio [HR]: 0.96; 95% confidence interval [CI]: 0.70-1.35; p = 0.864), while the five-year PFS rates were 55.8% and 51.0% (HR: 0.92; 95% CI: 0.68-1.26; p = 0.614), respectively. In comparison to patients in the low ΔPNI group, those in the high ΔPNI group exhibited a favorable association with both OS (HR: 0.57; 95% CI: 0.40-0.76; p < 0.001) and PFS (HR: 0.58; 95% CI: 0.43-0.79; p < 0.001). Stratified analysis based on ΔPNI revealed significant protective effects in the propofol-treated participants within the high ΔPNI group, whereas such effects were not observed in the low ΔPNI group, for both OS (p for interaction = 0.004) and PFS (p for interaction = 0.024). CONCLUSIONS: Our data revealed that among patients who underwent CRC surgery, those treated with TIVA-P exhibited superior survival outcomes compared to those who received IA-S, particularly among individuals with a high degree of PNI change.

Exploring the Potential Role of Dexmedetomidine in Reducing Postoperative Cognitive Dysfunction in Elderly Hip Fracture Patients.

BACKGROUND: Hip fractures are prevalent in the elderly; however, Postoperative Cognitive Dysfunction (POCD) is a possible complication of hip fracture surgery in elderly patients. This study examines the influence and the underlying mechanism of dexmedetomidine on POCD in elderly patients following hip fracture surgery. METHODS: The retrospective study involved elderly patients with hip fracture who were treated at the Fifth Affiliated Hospital of Xinjiang Medical University from October 2021 to August 2022. During the surgery procedures, dexmedetomidine was administrated and the peripheral blood samples were collected from the patients. Inflammatory factors were measured using Enzyme-linked immunosorbent assay (ELISA), while pyroptosis-related proteins were detected through quantitative reverse transcription PCR (RT-qPCR) and western blot. Additionally, the levels of CD4+T and CD8+T cells were assessed using flow cytometry. An aged rats hip fracture model was established to further investigate the impact of dexmedetomidine on postoperative mobility, cognition function, pyroptosis and immune cells in rats. RESULTS: Postoperative cognitive function in patients did not show significant alteration when compared with pre-operation levels (p > 0.05). There were notable reduction in the levels of interleukin-18 (IL-18), Caspase-3, Gasdermin-D (GSDMD) and NLR Family Pyrin Domain Containing 3 (NLRP3) (p < 0.001), accompanied by an increase in the proportion of CD4+T cells and an decrease in CD8+T cells after operation (p < 0.01). In aged rats, postoperative exploratory activities increased compared to their preoperative state. Compared with preoperative levels, the levels of interleukin-1ß (IL-1ß), IL-18, Caspase-3, GSDMD, and NLRP3 were significantly decreased (p < 0.001), the proportion of CD4+T cells was increased, and the proportion of CD8+T cells was decreased postoperatively (p < 0.01). CONCLUSIONS: Although there was no significant alteration in postoperative cognitive function in patients, dexmedetomidine may still play a role in mitigating POCD potentially due to its effects on reducing immune inflammation and pyroptosis markers. Further research is needed to fully understand the underlying mechanisms and its clinical implications.

Evaluation of the performance of a novel HIV-1 viral load assay for HIV quantification in China.

OBJECTIVES: Our objective was to assess the HIV-1 quantification performance of the Livzon HIV-1 viral load (VL) assay and the Roche Cobas HIV-1 assay to evaluate an HIV-1 VL testing reagent for application in China. METHOD: We compared the Livzon and Roche Cobas HIV-1 VL assays using ethylenediaminetetraacetic acid plasma samples collected between May 2021 and November 2021 from patients with HIV-1 and healthy controls. We used Cohen's κ coefficient to measure agreement of qualitative values and Pearson's correlation coefficient (r) values and the coefficient of determination (R2 ) to determine the linear relationship between the two assays. We performed a Bland-Altman analysis to assess VL quantification agreement. RESULTS: In total, 11 plasma samples from patients with hepatitis B virus (HBV) or hepatitis C virus (HCV) and nine samples from healthy controls were undetectable on both assays. Overall agreement was seen in 419 of 500 specimens (91.40%), with a κ value of 0.59. Pearson's correlation coefficient between the two assays was 0.970. Using the Bland-Altman method, 95.14% (352/370) of paired VLs fell within the 95% confidence limits of agreement (-0.51 to 0.95 log10  copies/mL). Higher VLs had a better correlation and a smaller mean difference between the two assays. Pearson's correlation coefficient for the samples of subtype CRF01_AE, CRF07_BC, and CRF55_01B was 0.950, 0.935, and 0.952, respectively. CONCLUSION: The Livzon HIV-1 VL assay exhibits good precision and linearity and a high correlation with the Roche Cobas HIV-1 assay. The Livzon HIV-1 VL assay has salient advantages in terms of the lyophilized powder reagent, which gives the assay greater stability and sensitivity and can be readily used in low-resource areas.

The equilibrative nucleoside transporter ENT1 is critical for nucleotide homeostasis and optimal erythropoiesis.

The tight regulation of intracellular nucleotides is critical for the self-renewal and lineage specification of hematopoietic stem cells (HSCs). Nucleosides are major metabolite precursors for nucleotide biosynthesis and their availability in HSCs is dependent on their transport through specific membrane transporters. However, the role of nucleoside transporters in the differentiation of HSCs to the erythroid lineage and in red cell biology remains to be fully defined. Here, we show that the absence of the equilibrative nucleoside transporter (ENT1) in human red blood cells with a rare Augustine-null blood type is associated with macrocytosis, anisopoikilocytosis, an abnormal nucleotide metabolome, and deregulated protein phosphorylation. A specific role for ENT1 in human erythropoiesis was demonstrated by a defective erythropoiesis of human CD34+ progenitors following short hairpin RNA-mediated knockdown of ENT1. Furthermore, genetic deletion of ENT1 in mice was associated with reduced erythroid progenitors in the bone marrow, anemia, and macrocytosis. Mechanistically, we found that ENT1-mediated adenosine transport is critical for cyclic adenosine monophosphate homeostasis and the regulation of erythroid transcription factors. Notably, genetic investigation of 2 ENT1null individuals demonstrated a compensation by a loss-of-function variant in the ABCC4 cyclic nucleotide exporter. Indeed, pharmacological inhibition of ABCC4 in Ent1-/- mice rescued erythropoiesis. Overall, our results highlight the importance of ENT1-mediated nucleotide metabolism in erythropoiesis.

GATA factor-regulated solute carrier ensemble reveals a nucleoside transporter-dependent differentiation mechanism.

Developmental-regulatory networks often include large gene families encoding mechanistically-related proteins like G-protein-coupled receptors, zinc finger transcription factors and solute carrier (SLC) transporters. In principle, a common mechanism may confer expression of multiple members integral to a developmental process, or diverse mechanisms may be deployed. Using genetic complementation and enhancer-mutant systems, we analyzed the 456 member SLC family that establishes the small molecule constitution of cells. This analysis identified SLC gene cohorts regulated by GATA1 and/or GATA2 during erythroid differentiation. As >50 SLC genes shared GATA factor regulation, a common mechanism established multiple members of this family. These genes included Slc29a1 encoding an equilibrative nucleoside transporter (Slc29a1/ENT1) that utilizes adenosine as a preferred substrate. Slc29a1 promoted erythroblast survival and differentiation ex vivo. Targeted ablation of murine Slc29a1 in erythroblasts attenuated erythropoiesis and erythrocyte regeneration in response to acute anemia. Our results reveal a GATA factor-regulated SLC ensemble, with a nucleoside transporter component that promotes erythropoiesis and prevents anemia, and establish a mechanistic link between GATA factor and adenosine mechanisms. We propose that integration of the GATA factor-adenosine circuit with other components of the GATA factor-regulated SLC ensemble establishes the small molecule repertoire required for progenitor cells to efficiently generate erythrocytes.

Conformations of Steroid Hormones: Infrared and Vibrational Circular Dichroism Spectroscopy.

Steroid hormone molecules may exhibit very different functionalities based on the associated functional groups and their 3D arrangements in space, i.e., absolute configurations and conformations. Infrared (IR) and vibrational circular dichroism (VCD) spectra of four different steroid hormones, namely dehydroepiandrosterone (DHEA), 17α-methyltestosterone (MTTT), (16α,17)-epoxyprogesterone (Epoxy-P4), and dehydroepiandrosterone acetate (AcO-DHEA), were measured in deuterated dimethyl sulfoxide and some also in carbon tetrachloride. Extensive conformational searches were carried out using the recent developed conformer-rotamer ensemble sampling tool (CREST) which also accounts for solvent effects using an implicit solvation model. All the CREST conformational candidates were then reoptimized at the B3LYP-D3BJ/def2-TZVPD with the PCM of solvent. The good agreements between the experimental IR and VCD spectra and the theoretical simulations provide a conclusive information about their conformational distribution and absolute configurations. The experimental and theoretical IR and VCD spectra of AcO-DHEA in the carbonyl and alkene stretching region showed some discrepancies, and the possible causes related to solvent effects, large amplitude motions and levels of theory used in the modelling were explored in detail. As part of the investigation, additional calculations at the B3LYP-D3BJ/6-31++G (2d,p) and B3LYP-D3BJ/cc-pVTZ levels, as well as some 'mixed' calculations with the double-hybrid functional B2PLYP-D3 were also carried out. The results indicate that the double-hybrid functional is important for predicting the correct IR band pattern in the carbonyl and alkene stretching region.

Metal-Organic Framework-Based Artificial Organelle Corrects Microenvironment Interference for Accurate Intratumoral Glucose Analysis.

Enzymatic catalysis with high efficiency allows them a great prospect in metabolite monitoring in living cells. However, complex tumor microenvironments, such as acidity, H2 O2 , and hypoxia, are bound to disturb catalytic reactions for misleading results. Here, we report a spatially compartmentalized artificial organelle to correct intratumoral glucose analysis, where the zeolitic imidazolate framework-8 immobilized glucose oxidase-horseradish peroxidase cascade core and catalase-directed shell act as signal transduction and guarding rooms respectively. The acid-digested core and stable shell provide appropriate spaces to boost biocatalytic efficiency with good tolerability. Notably, the endogenous H2 O2 is in situ decomposed to O2 by catalase, which not only overcomes the interference in signal output but also alleviates the hypoxic states to maximize glucose oxidation. The marked protective effect and biocompatibility render artificial organelles to correct the signal transduction for dynamic monitoring glucose in vitro and in vivo, achieving our goal of accurate intratumoral metabolite analysis.

Drug resistance and genetic transmission characteristics of HIV-1 CRF59_01B in infected patients in Guangdong Province, China.

OBJECTIVES: To comprehensively analyse the prevalence of drug resistance and the transmission characteristics of CRF59_01B strains in infected patients in Guangdong, China. METHODS: CRF59_01B-infected individuals were recruited, and the HIV-1 pol region was amplified. Drug resistance-associated mutations (DRMs) and antiretroviral susceptibility were examined using the Stanford University HIV Drug Resistance Database to analyse pretreatment drug resistance (PDR) and acquired drug resistance (ADR). Genetic transmission networks were extracted from the maximum likelihood phylogenetic tree with Cluster Picker and visualized with Cytoscape. RESULTS: Two hundred and twenty-five CRF59_01B-infected individuals, comprising 35 ART-experienced and 190 ART-naive individuals, were recruited. No patients harboured PI DRMs, 5.33% (12/225) of the patients harboured NRTI DRMs and 11.11% (25/225) of the patients harboured NNRTI DRMs. The overall prevalence of strains with ADR was 51.43% (18/35), while the prevalence of strains with PDR was 2.63% (5/190). A total of 20 transmission networks, involving 25.78% (58/225) database-derived sequences, were identified. The networks ranged in size from 2 to 10 individuals, of which most (55.00%, 11/20) were made up of two individuals. Among the 225 study subjects, 9.78% (22/225) had 1 link and 16.00% (36/225) had ≥2 links. CONCLUSIONS: The overall prevalence of CRF59_01B strains with ADR among the ART-experienced patients was high. Although the overall prevalence of CRF59_01B strains with PDR among the ART-naive patients was low, it is necessary to remain vigilant regarding some important DRMs.

Single-Atom-Based Heterojunction Coupling with Ion-Exchange Reaction for Sensitive Photoelectrochemical Immunoassay.

Benefiting from the maximum atom-utilization efficiency and distinct structural features, single-atom catalysts open a new avenue for the design of more functional catalysts, whereas their bioapplications are still in their infancy. Due to the advantages, platinum single atoms supported by cadmium sulfide nanorods (Pt SAs-CdS) are synthesized to build an ultrasensitive photoelectrochemical (PEC) biosensing platform. With the decoration of Pt SAs, the PEC signal of CdS is significantly boosted. Furthermore, theory calculations indicate the positively charged Pt SAs could change the charge distribution and increase the excited carrier density of CdS. Meanwhile, it also suggests that Cu2+ can severely hinder the photoexcitation and electron-hole separation of CdS. As a proof of concept, prostate-specific antigen is chosen as the target analyte to demonstrate the superiority of the Pt SAs-CdS-based PEC sensing system. As a result, the PEC biosensor based on Pt SAs-CdS exhibits outstanding detection sensitivity and promising applicability.

Tuning the Ratio of Pt(0)/Pt(II) in Well-Defined Pt Clusters Enables Enhanced Electrocatalytic Reduction/Oxidation of Hydrogen Peroxide for Sensitive Biosensing.

Rational design and construction of advanced sensing platforms for sensitive detection of H2O2 released from living cells is one of the challenges in the field of physiology and pathology. Noble metal clusters are a kind of nanomaterials with well-defined chemical composition and special atomic structures, which have been widely explored in catalysis, biosensing, and therapy. Compared with noble metal nanoparticles, noble metal clusters exhibit great potential in electrochemical biosensing due to their high atom utilization efficiency and abundant reactive active sites. Herein, Pt nanoclusters anchored on hollow carbon spheres (PtNCS/HCS) were successfully prepared for sensitive detection of H2O2. By tuning the ratio of Pt(0)/Pt(II) at different annealing temperatures, the optimized PtNCS/HCS-550 showed higher H2O2 reduction and oxidation catalytic activities than other control samples. Density functional theory calculations revealed that H2O2*can be better activated and dissociated in the Pt0II model featured with the co-existence of Pt(0)/Pt(II) and the key intermediates OOH*/OH* have a stronger interaction with the Pt0II model. As a concept application, the electrochemical biosensing platform was successfully applied to sensitive detection of H2O2 released from the cells.

Axial Ligand-Engineered Single-Atom Catalysts with Boosted Enzyme-Like Activity for Sensitive Immunoassay.

Inspired by the key role of the coordination environment in the catalytic activity of enzymes, a rational design of the coordination structure of active sites at the atom scale is expected to develop high-performance enzyme-like catalysts. Here, we design a simple model system involving pentacoordinated and tetracoordinated Fe-N-C single-atom catalysts (named NG-Heme and G-Heme, respectively) to investigate structure-activity relationships. NG-Heme with axial ligand-engineered Fe sites exhibits superior enzyme-like activity to G-Heme, achieving the goal of vivid mimicking of the active sites of peroxidase. Experiments and theoretical studies reveal that the enhanced intrinsic catalytic activity originates from the "push effect" of the additional axial ligand, which can strengthen the interaction between the active site and the intermediate. Based on the outstanding catalytic activity, an NG-Heme-linked immunosorbent assay was constructed for colorimetric detection of carcinoembryonic antigen, exhibiting satisfactory sensitivity and feasibility in the analysis of clinical samples.

Transmitted drug resistance and transmission clusters among HIV-1 treatment-naïve patients in Guangdong, China: a cross-sectional study.

BACKGROUND: Transmitted drug resistance (TDR) that affects the effectiveness of the first-line antiretroviral therapy (ART) regimen is becoming prevalent worldwide. However, its prevalence and transmission among HIV-1 treatment-naïve patients in Guangdong, China are rarely reported. We aimed to comprehensively analyze the prevalence of TDR and the transmission clusters of HIV-1 infected persons before ART in Guangdong. METHODS: The HIV-1 treatment-naïve patients were recruited between January 2018 and December 2018. The HIV-1 pol region was amplified by reverse transcriptional PCR and sequenced by sanger sequencing. Genotypes, surveillance drug resistance mutations (SDRMs) and TDR were analyzed. Genetic transmission clusters among patients were identified by pairwise Tamura-Nei 93 genetic distance, with a threshold of 0.015. RESULTS: A total of 2368 (97.17%) HIV-1 pol sequences were successfully amplified and sequenced from the enrolled 2437 patients. CRF07_BC (35.90%, 850/2368), CRF01_AE (35.56%, 842/2368) and CRF55_01B (10.30%, 244/2368) were the main HIV-1 genotypes circulating in Guangdong. Twenty-one SDRMs were identified among fifty-two drug-resistant sequences. The overall prevalence of TDR was 2.20% (52/2368). Among the 2368 patients who underwent sequencing, 8 (0.34%) had TDR to protease inhibitors (PIs), 22 (0.93%) to nucleoside reverse transcriptase inhibitors (NRTIs), and 23 (0.97%) to non-nucleoside reverse transcriptase inhibitors (NNRTIs). Two (0.08%) sequences showed dual-class resistance to both NRTIs and NNRTIs, and no sequences showed triple-class resistance. A total of 1066 (45.02%) sequences were segregated into 194 clusters, ranging from 2 to 414 sequences. In total, 15 (28.85%) of patients with TDR were included in 9 clusters; one cluster contained two TDR sequences with the K103N mutation was observed. CONCLUSIONS: There is high HIV-1 genetic heterogeneity among patients in Guangdong. Although the overall prevalence of TDR is low, it is still necessary to remain vigilant regarding some important SDRMs.

Modulating the bicoid gradient in space and time.

BACKGROUND: The formation of the Bicoid (Bcd) gradient in the early Drosophila is one of the most fascinating observations in biology and serves as a paradigm for gradient formation, yet its mechanism is still not fully understood. Two distinct models were proposed in the past, the SDD and the ARTS model. RESULTS: We define novel cis- and trans-acting factors that are indispensable for gradient formation. The first one is the poly A tail length of the bcd mRNA where we demonstrate that it changes not only in time, but also in space. We show that posterior bcd mRNAs possess a longer poly tail than anterior ones and this elongation is likely mediated by wispy (wisp), a poly A polymerase. Consequently, modulating the activity of Wisp results in changes of the Bcd gradient, in controlling downstream targets such as the gap and pair-rule genes, and also in influencing the cuticular pattern. Attempts to modulate the Bcd gradient by subjecting the egg to an extra nuclear cycle, i.e. a 15th nuclear cycle by means of the maternal haploid (mh) mutation showed no effect, neither on the appearance of the gradient nor on the control of downstream target. This suggests that the segmental anlagen are determined during the first 14 nuclear cycles. Finally, we identify the Cyclin B (CycB) gene as a trans-acting factor that modulates the movement of Bcd such that Bcd movement is allowed to move through the interior of the egg. CONCLUSIONS: Our analysis demonstrates that Bcd gradient formation is far more complex than previously thought requiring a revision of the models of how the gradient is formed.

Characteristics of drug resistance in HIV-1 CRF55_01B from ART-experienced patients in Guangdong, China.

BACKGROUND: HIV-1 acquired drug resistance (ADR) has become a critical clinical and public health issue. Recently, HIV-1 CRF55_01B has been found more frequently in the MSM population. OBJECTIVE: To investigate the characteristics of HIV-1 drug resistance mutations (DRMs) and the extent of changes in drug susceptibility among ART-experienced CRF55_01B-infected adults of Guangdong. METHODS: ADR was tested for immediately in CRF55_01B-infected patients with virological failure. Demographic and epidemiological information was collected. DRMs and antiretroviral susceptibility were interpreted using the Stanford University HIV Drug Resistance Database HIVdb program. RESULTS: Overall, 162 (4.78%) CRF55_01B isolates were identified from 2013 to 2018. Among DRMs, M184V (43.83%) was the most frequent NRTI DRM, followed by K65R (23.46%), and V179E (98.77%) was the most frequent NNRTI DRM, followed by K103N (47.53%) and Y181C (14.81%). According to the HIVdb program, 79.01% of the CRF55_01B-infected patients carried mutations conferring low-level or higher drug resistance to any of the three classes of ART drugs. Among PI DRMs, only one mutation affording low-level resistance to nelfinavir was found (0.62%). Among NRTI DRMs, a high proportion of high-level resistance to lamivudine (58.64%) and emtricitabine (58.02%) was found. As regards NNRTIs, more than 75% of patients carried efavirenz and nevirapine DRMs. The percentages of high-level resistance were 70.99%, 63.58%, 22.22%, 17.90% and 4.32% for nevirapine, efavirenz, rilpivirine, doravirine and etravirine, respectively. CONCLUSIONS: High frequencies of DRMs and resistance were observed among CRF55_01B-infected patients failing ART in Guangdong, and interventions may be considered to minimize ecological contributions to ART.

Multicenter evaluation of Xpert HIV-1 viral load assay for HIV quantification in China.

New approaches to increase HIV-1 testing and HIV-1 viral load (VL) monitoring are needed for people living with HIV (PLHIV) in China. The Xpert HIV-1 VL assay was prequalified by the World Health Organization in 2017 but has not been evaluated in China. A multicenter evaluation was conducted to assess the accuracy of the Cepheid Xpert HIV-1 VL assay compared to the Abbott RealTime HIV-1 assay in China. Overall agreement was seen in 558 of 562 specimens (99.29%) with a κ value of 0.962. Pearson's coefficient between the two assays was 0.943. Analyzed by the Bland-Altman method, the mean bias was -0.54 log10 copies/mL, and 94.05% results fell within the 95% confidence limit of agreement (-1.248 to 0.168 log10 copies/mL). The coefficient of variation of the Cepheid Xpert HIV-1 VL assay ranged from 0.61% to 1.55%, as determined by testing eight positive plasma specimens with three different lots on different days. Due to its simplicity, random-access, rapid turnaround time, and accuracy, the Xpert HIV-1 VL assay can be used in local hospitals and clinics that bear the burden of identifying and treating HIV patients in China.

Normative Pancreatic Stiffness Levels and Related Influences Established by Magnetic Resonance Elastography in Volunteers.

BACKGROUND: Large-scale normative studies of pancreatic stiffness and potential influences have yet to be pursued via magnetic resonance elastography (MRE). PURPOSE: To determine normative MRE-based pancreatic stiffness values and to examine related influential factors. STUDY TYPE: Prospective. SUBJECTS: In all, 361 volunteers (men, 199; women, 162) with a median age of 54.0 years and a median body mass index (BMI) of 22.86 kg/m2 were prospectively recruited. Those with no histories of smoking, alcohol abuse, and diabetes mellitus (DM) were grouped as healthy volunteers, designating all others as positive controls. FIELD STRENGTH/SEQUENCE: Each volunteer underwent 3.0T pancreatic MRI at a frequency of 40 Hz. ASSESSMENT: Pancreatic stiffness values, pancreatic width and volume, waist circumference, and wave distance were measured in all subjects. STATISTICAL TESTS: Multiple linear regression analyses were performed to determine variables that influence MRE-determined stiffness. RESULTS: The mean pancreatic stiffness in all volunteers was 1.20 ± 0.16 kPa. Stiffness levels in positive control volunteers proved significantly greater than levels in healthy volunteers (1.29 ± 0.17 kPa vs. 1.14 ± 0.13 kPa; P < 0.001). In multiple linear regression analysis, sex (P = 0.004), BMI (P < 0.001), pancreatic width (P = 0.005), smoking (P < 0.001), alcohol abuse (P < 0.001), and DM (P = 0.001) emerged as significant independent factors impacting pancreatic stiffness. Smoking, alcohol abuse, DM, and wide pancreas were associated with greater pancreatic stiffness (coefficients = 0.202, 0.183, 0.149, and 0.160, respectively), while reduced pancreatic stiffness corresponded with female sex and larger BMI (coefficient = -0.155 and -0.192, respectively). DATA CONCLUSION: MRE-based pancreatic stiffness values are impacted by sex, BMI, pancreatic width, smoking, alcohol abuse, and DM. Reference values are essential for future clinical studies. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:448-458.

Overcoming blood-brain barrier transport: Advances in nanoparticle-based drug delivery strategies.

The Blood-Brain Barrier (BBB), a unique structure in the central nervous system (CNS), protects the brain from bloodborne pathogens by its excellent barrier properties. Nevertheless, this barrier limits therapeutic efficacy and becomes one of the biggest challenges in new drug development for neurodegenerative disease and brain cancer. Recent breakthroughs in nanotechnology have resulted in various nanoparticles (NPs) as drug carriers to cross the BBB by different methods. This review presents the current understanding of advanced NP-mediated non-invasive drug delivery for the treatment of neurological disorders. Herein, the complex compositions and special characteristics of BBB are elucidated exhaustively. Moreover, versatile drug nanocarriers with their recent applications and their pathways on different drug delivery strategies to overcome the formidable BBB obstacle are briefly discussed. In terms of significance, this paper provides a general understanding of how various properties of nanoparticles aid in drug delivery through BBB and usher the development of novel nanotechnology-based nanomaterials for cerebral disease therapies.

Pancreatic adenocarcinoma: quantitative CT features are correlated with fibrous stromal fraction and help predict outcome after resection.

OBJECTIVES: To identify quantitative imaging features of contrast-enhanced computed tomography (CE-CT) that may be prognostically favorable after resection of smaller (≤ 30 mm) pancreatic ductal adenocarcinomas (PDACs) located at head. METHODS: This retrospective study included two independent cohorts (discovery cohort, n = 212; test cohort, n = 100) of patients who underwent resection of head PDACs ≤ 30 mm and preoperative CE-CT. We examined tumor and surrounding parenchymal attenuation differences (deltas), and tumor attenuation changes across phases (ratios). Semantic features of PDACs were evaluated by two radiologists. Clinicopathologic and imaging features for predicting disease-free survival (DFS) and overall survival (OS) were analyzed via multivariate Lasso-penalized Cox proportional-hazards models. Survival rates were derived by Kaplan-Meier method. RESULTS: Imaging features achieved C-indices of 0.766 (discovery cohort) and 0.739 (test cohort) for DFS, and 0.790 (discovery cohort) and 0.772 (test cohort) for OS estimates through incorporation of clinicopathologic features. The most decisive imaging feature was delta 3, denoting attenuation differences between tumor and surrounding pancreas at pancreatic phase (DFS: HR = 2.122; OS: HR = 2.375; both p < 0.001). Compared with inconspicuous (low-delta-3, < 28 HU) tumors, conspicuous (high-delta-3) tumors correlated significantly with more aggressive histologic grades (p = 0.014) and less extensive tumor fibrous stromal fractions (p < 0.001). Patients with low-delta-3 tumors ≤ 20 mm experienced the most favorable outcomes (DFS, 36 months; OS, 42 months), whereas those with high-delta-3 tumors fared poorly, regardless of tumor size (DFS, 12 months; OS, 19 months). CONCLUSIONS: Quantifiable CT imaging features reflect heterogeneous fibrous stromal fractions and histologic grades of PDAC at head locations that help stratify patients with disparate clinical outcomes. KEY POINTS: • Quantitative and semantic imaging features achieved promising results for the prognosis of resected PDAC (≤ 30 mm) at head location, through incorporation of clinicopathologic features. • Attenuation difference at tumor-parenchyma interface (delta 3) emerged as the most decisive imaging feature, enabling further stratification of patients into distinct prognostic subtypes by tumor size. • High delta 3 signifies sharper contrast between tumor and surrounding pancreas, correlating with more aggressive histologic grades and less extensive tumor fibrous stromal fractions.