[Progress in stimuli-responsive molecularly imprinted polymers for enrichment analysis of trace components in traditional Chinese medicine].

Molecularly imprinted polymers demonstrate outstanding performance in the research on trace ingredients because of their high selectivity. Stimuli-responsive molecularly imprinted polymers(STR-MIPs) with the introduction of different responsive groups on the basis of traditionally imprinted materials can undergo reversible transformations when exposed to external stimuli such as temperature, magnetism, pH or light. Such responsiveness, combined with the specific recognition, endows STR-MIPs with excellent perfor-mance in trace component studies. Traditional Chinese medicine(TCM) contains complex components with trace content, and thus STR-MIPs have broad application prospects in the enrichment analysis of trace components in TCM. This paper elaborates on the application of STR-MIPs in the enrichment analysis of trace components in TCM from the perspectives of different stimuli, summarized relevant research achievements in the recent five years to broaden the application fields of molecular imprinting, and proposed a few opi-nions about their future development.

Red fluorescent nanoprobe based on Ag@Au nanoparticles and graphene quantum dots for H2O2 determination and living cell imaging.

A sensitive and turn-on fluorescence nanoprobe based on core-shell Ag@Au nanoparticles (Ag@AuNPs) as a fluorescence receptor and red emissive graphene quantum dots (GQDs) as a donor was fabricated. They were conjugated together through π-π stacking between the GQDs and single-strand DNA modified at the Ag@AuNPs surface. The absorption spectrum of the receptor significantly overlapped with the donor emission spectrum, leading to a strong Förster resonance energy transfer (FRET) and thus a dramatic quenching. The sensing mechanism relies on fluorescence recovery following DNA cleavage by •OH produced from Fenton-like reaction between the peroxidase-like Ag nanocore and H2O2. The red emissive feature (Ex/Em, 520 nm/560 nm) provides low background in physiological samples. The •OH production, great spectrum overlapping, and red emission together contributes to good sensitivity and living cell imaging capability. The fluorescence assay (intensity at 560 nm) achieves a low detection limit of 0.49 µM H2O2 and a wide linear range from 5 to 200 µM, superior to most of the reported fluorescent probes. The RSD value for 100 µM H2O2 was 1.4%. The nanoprobe exhibits excellent anti-interferences and shows low cytotoxicity. The recovery of 100 µM standard H2O2 in a cancer cell lysate was 85.8%. Most satisfactorily, it can realize monitoring and imaging H2O2 in living cells. This study not only presents a sensitive H2O2 probe but also provides a platform for detecting other types of reactive oxygen species.

Reductive Coupling between C-N and C-O Electrophiles.

The cross-electrophile reaction is a promising strategy for C-C bond formation. Recent studies have focused mainly on reactions with organic halides. Here we report a coupling reaction between C-N and C-O electrophiles that demonstrates the possibility of constructing a C-C bond via C-N and C-O cleavage. Several reactions between benzyl/aryl ammonium salts and vinyl/aryl C-O electrophiles have been studied. Preliminary mechanistic studies revealed that the benzyl ammoniums were activated through a radical mechanism.

The Role of KLRG1 in Human CD4+ T-Cell Immunity Against Tuberculosis.

Background: KLRG1 is a marker of terminally differentiated CD8+ T cells in viral infection, but its role in human Mycobacterium tuberculosis infection remains elusive. Methods: A set of cohorts of patients with tuberculosis was designed, and the expression profiles and functions of KLRG1+CD4+ T cells were determined with and without antibody blocking. Results: KLRG1 expression on CD4+ T cells was significantly increased in patients with active tuberculosis, compared with healthy controls and patients without tuberculosis. Upon M. tuberculosis-specific stimulation, the ability to secrete interferon γ, interleukin 2, and tumor necrosis factor α was significantly greater in KLRG1-expressing CD4+ T cells than in their KLRG-negative counterparts and was accompanied by a decreased proportion of regulatory T cells and increased Akt signaling. However, KLRG1-expressing CD4+ T cells had a shorter life-span, which was associated with a higher apoptosis rate but a similar proliferative response. Blockade of KLRG1 signaling significantly enhanced interferon γ and interleukin 2 secretion without affecting either cell apoptosis or multiplication. Addition of a specific Akt inhibitor prevented this increased cytokine response, implicating the Akt signaling pathway. Conclusions: Our study delineated the profile of KLRG1+CD4+ T cells in patients with tuberculosis and suggests that M. tuberculosis infection drives CD4+ T cells to acquire increased effector function in a terminally differentiated state, which is restrained by KLRG1 via KLRG1/Akt signaling pathway.

Humanin rescues cultured rat cortical neurons from NMDA-induced toxicity not by NMDA receptor.

Excitatory neurotoxicity has been implicated in many pathological situations and there is no effective treatment available. Humanin is a 24-aa peptide cloned from the brain of patients with Alzheimer's disease (AD). In the present study, excitatory toxicity was induced by N-methyl-D-aspartate (NMDA) in primarily cultured rat cortical neurons. MTT assessment, lactate dehydrogenase (LDH) release, and calcein staining were employed to evaluate the protective activity of humanin on NMDA induced toxicity. The results suggested that NMDA (100 µmol/L, 2.5 hr) triggered neuronal morphological changes, lactate dehydrogenase (LDH) release (166% of the control), reduction of cell viability (about 50% of the control), and the decrease of living cell density (about 50% of the control). When pretreated with humanin, the toxicity was suppressed. The living cells' density of humanin treated group was similar to that of control. The cell viability was attenuated dose-dependently (IC50 = 0.132 nmol/L). The LDH release was also neutralized in a dose-dependent manner. In addition, the intracellular Ca(2+) overloading triggered by NMDA reverted quickly and humanin could not inhibit it. These findings indicate that humanin can rescue cortical neurons from NMDA-induced toxicity in rat but not through interfering with NMDA receptor directly.

[Gelsolin level for prognostic evaluation in patients with critically illness].

OBJECTIVE: To investigate the changes of plasma gelsolin level in patients with critical illness and its application in prognostic evaluation. METHODS: Ninety six critically ill patients admitted in ICU of Sichuan Provincial People's Hospital from February 2012 to December 2013 were enrolled in the prospective cohort study. Plasma gelsolin levels were detected with enzyme linked immunosorbent assay (ELISA) at admission (d1), d2, d4 and d8 after admission, and also detected in blood samples of 186 healthy subjects as controls. Logistic regression model was used to analyze the relationship between the level of plasma gelsolin and prognosis of patients. RESULTS: The average levels of plasma gelsolin were significantly lower in critically ill patients than those in control subjects (F=1986.37, P<0.01). There was significant difference in overall level of gelsolin between survival patients and fatal patients (F=16.691, P<0.01). APACHE Ⅱ score was associated with survival outcomes (r=0.489, P=0.009); the APACHE Ⅱ score was significantly higher in fatal patients than that in survival patients (29.5±7.7 vs 22.1±5.7, t=5.375, P<0.01). There was a negative correlation between plasma gelsolin levels and fatal outcomes (r=-0.512, P<0.01). Logistic regression analysis showed that the overall plasma gelsolin levels and the last measured level was a prognostic factor for critically ill patients (P<0.05). CONCLUSION: Plasma gelsolin levels are correlated with the severity of critically ill patients, and plasma gelsolin can be used as indicator of prognosis.

Emergence of a novel GIII Getah virus variant in pigs in Guangdong, China, 2023.

From May to July of 2023, one pig farm in Heyuan city, Guangdong Province of China, suffered severe piglet death and sow reproductive disorders. The common pig viruses and bacteria tested negative. To uncover the possible cause of the disease, a metagenomic analysis was performed in the pooled small intestine samples from three 8-day-old diseased piglets. The results showed that Getah virus (GETV), an RNA virus, might be the potential pathogen that affects pig health. Subsequently, GETV nucleotide was detected in all of the 15 samples collected from three diseased piglets using quantitative reverse transcription PCR, suggesting GETV as the main pathogen of the disease. A GETV strain, designated as GDHYLC23, was successfully isolated using the swine testicle cell line. Sequence analysis showed that the epidemic strain had a unique 32-nucleotide repeat insertion in the 3' noncoding region. Phylogenetic analysis showed that GDHYLC23 belonged to the pandemic group III. The identification of GETV with new variations implies the continuous evolution of the virus, which poses potential threats to the swine industry.IMPORTANCEPig farms are faced with emerging and re-emerging viruses that may cause substantial economic loss. The identification of potentially pathogenic viruses helps to prevent and control the spread of diseases. In this study, by using metagenomic analysis, we found that a neglected virus, GETV with a unique insertion in the genome, was the main pathogen in one pig farm that suffered severe piglet death and sow reproductive disorders. Although the potential impact of such an insertion on viral pathogenicity is unknown, the surveillance of the continuing evolution of GETV in pig farms cannot be ignored.

Optimization and mechanisms of proteolytic enzyme immobilization onto large-pore mesoporous silica nanoparticles: Enhanced tumor penetration.

Immobilization of proteolytic enzymes onto nanocarriers is effective to improve drug diffusion in tumors through degrading the dense extracellular matrix (ECM). Herein, immobilization and release behaviors of hyaluronidase, bromelain, and collagenase (Coll) on mesoporous silica nanoparticles (MSNs) were explored. A series of cationic MSNs (CMSNs) with large and adjustable pore sizes were synthesized, and investigated together with two anionic MSNs of different pore sizes. CMSNs4.0 exhibited the highest enzyme loading capacity for hyaluronidase and bromelain, and CMSNs4.5 was the best for Coll. High electrostatic interaction, matched pore size, and large pore volume and surface area favor the immobilization. Changes of the enzyme conformations and surface charges with pH, existence of a space around the immobilized enzymes, and the depth of the pore structures, affect the release ratio and tunability. The optimal CMSNs-enzyme complexes exhibited deep and homogeneous penetration into pancreatic tumors, a tumor model with the densest ECM, with CMSNs4.5-Coll as the best. Upon loading with doxorubicin (DOX), the CMSNs-enzyme complexes induced high anti-tumor efficiencies. Conceivably, the DOX/CMSNs4.5-NH2-Coll nanodrug exhibited the most effective tumor therapy, with a tumor growth inhibition ratio of 86.1 %. The study provides excellent nanocarrier-enzyme complexes, and offers instructive theories for enhanced tumor penetration and therapy.

pH-Sensitive Biomimetic Nanosystem Based on Large-Pore Mesoporous Silica Nanoparticles with High Hyaluronidase Loading for Tumor Deep Penetration.

Loading hyaluronidase (Hyal) in a nanocarrier is a potent strategy to degrade the tumor extracellular matrix for tumor deep penetration and enhanced tumor therapy. Herein, a pH-sensitive biomimicking nanosystem with high Hyal loading, effective tumor targeting, and controllable release is constructed. Specifically, cationic mesoporous silica nanoparticles (CMSNs) with large pores 13.52 nm in diameter were synthesized in a one-pot manner by adding N-[3-trimethoxysilylpropyl]-N,N,N-trimethylammonium to a reversed microemulsion reaction system. The Hyal loading rate was as high as 19.47% owing to matched pore size and the cationic surface charge. Subsequently, a pH-sensitive biomimetic hybrid membrane (pHH) composed of pH-sensitive liposome (pHL), red blood cell membrane, and pancreatic cancer cell membrane was camouflaged on the pHL-coated and doxorubicin/Hyal-loaded CMSNs (shortened as DHCM). The DHCM@pHL@pHH is stable at neutral pH while it releases the payloads smoothly in the tumor acidic microenvironment. Consequently, it can escape from macrophage clearance, be specifically taken up by pancreatic cancer cells, and efficiently accumulate at the tumor site. More importantly, it can penetrate deeply in pancreatic tumors with a tumor growth inhibition ratio of 80.46%. The nanosystem is biocompatible and has potential for clinical transformation, and the nanocarrier is promisingly applicable as a platform for encapsulation of various macromolecules for smart and tumor-targeted delivery.

Development of a multiplex qRT-PCR assay for the detection of porcine epidemic diarrhea virus, porcine transmissible gastroenteritis virus and porcine Deltacoronavirus.

Currently, porcine coronaviruses are prevalent in pigs, and due to the outbreak of COVID-19, porcine coronaviruses have become a research hotspot. porcine epidemic diarrhea virus (PEDV), Transmissible Gastroenteritis Virus (TGEV), and Porcine Deltacoronavirus (PDCoV) mentioned in this study mainly cause diarrhea in pigs. These viruses cause significant economic losses and pose a potential public health threat. In this study, specific primers and probes were designed according to the M gene of PEDV, the S gene of TGEV, and the M gene of PDCoV, respectively, and TaqMan probe-based multiplex real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was developed for the simultaneous detection of PEDV, TGEV, and PDCoV. This method has high sensitivity and specificity, and the detection limit of each virus can reach 2.95 × 100 copies/µl. An assay of 160 clinical samples from pigs with diarrhea showed that the positive rates of PEDV, TGEV, and PDCoV were 38.13, 1.88, and 5.00%; the coinfection rates of PEDV+TGEV, PEDV+PDCoV, TGEV+PDCoV, PEDV+TGEV+PDCoV were 1.25, 1.25, 0, 0.63%, respectively. The positive coincidence rates of the multiplex qRT-PCR and single-reaction qRT-PCR were 100%. This method is of great significance for clinical monitoring of the porcine enteric diarrhea virus and helps reduce the loss of the breeding industry and control the spread of the disease.

[Analysis of the risk factors for pesticide poisoning among children in countryside of Guigang city].

OBJECTIVE: This study was to investigate the risk factors for pesticide poisoning among rural children in Guigang. METHODS: A 1:4 matched case-control study was conducted. A total of 78 rural children who were hospitalized or visited the out-patient clinic due to pesticide poisoning in Guigang from January to December in 2009 were recruited as cases, and 312 matched controls were recruited during the same time. The children's parents or guardians were surveyed with a questionnaire. The questionnaire including general information and 21 possible risk factors concerned in family structure, guardian status, educational level of parents, average annual family income, family and school health education and dangerous behavior in children. The data were analyzed by conditional logistic regression analysis. RESULTS: Three risk factors and five protective factors were identified significantly associated with pesticide poisoning in rural children. The risk factors included inappropriate deposit of hydrocomion and contaminated working clothes (OR = 3.529, 95%CI: 1.408 - 8.848), playing outside frequently (OR = 2.846, 95%CI: 1.513 - 5.352), grandparents being children's guardian (OR = 2.187, 95%CI: 1.187 - 4.029). The protective factors included high frequency of guardianship (OR = 0.408, 95%CI: 0.205 - 0.811), knowledge for poisoning prevention (OR = 0.412, 95%CI: 0.224 - 0.758), washing working clothes in time (OR = 0.435, 95%CI: 0.212 - 0.893), taking health educational courses in school (OR = 0.448, 95%CI: 0.232 - 0.867) and teaching children non-access to toxic agents regularly (OR = 0.462, 95%CI: 0.227 - 0.939). CONCLUSION: Childhood pesticide poisoning accidence in countryside of Guigang was caused by multiple factors including children's risk behaviors, family factors, environmental factors and health education.

[Development of determination of germanium hydride in the air of workplace by atomic fluorescence].

OBJECTIVE: An atomic fluorescence (AFS) method was developed to determine germanium hydride in the air of workplace. METHOD: Germanium hydride in the air of workplace was collected by charcoal tube, and desorbed by nitric acid followed filtration with 0.22 microm cellulose filter, the AFS was used to determine Germanium in the desorbed solution. RESULTS: The linear was good at the range of 0.85-300 microg/L with the correlation coefficient of 0.9993; the LOD and LOQ were 0.51 microg/L and 0.000 17 mg/m3, respectively. The recovery was ranged from 90% to 106%, the RSD of intra- and inter- precision were 3.3%-5.9% and 3.7%-6.3%. CONCLUSION: The linear range, sensitivity and precision of the method were all satisfied for the determination of germanium hydride in the air of workplace.

Effect of individualized medical nutrition guidance on pregnancy outcomes in older pregnant women.

OBJECTIVE: We aimed to explore the effect of individualized medical nutrition guidance on pregnancy outcomes among older pregnant women. METHODS: This was a prospective study using a randomized controlled trial design. We selected 820 older pregnant women and randomly divided them into a study group and control group (410 women each). The control group was given routine health education and nutrition guidance; the study group was provided individualized medical nutrition guidance. Gestational diabetes mellitus, hypertensive disorders of pregnancy, vaginal delivery rate, postpartum hemorrhage rate, gestational body weight, neonatal birth weight, and neonate transfer to the neonatal intensive care unit (NICU) were compared between the groups. RESULTS: The incidence of gestational diabetes in the study group was significantly lower and the rate of vaginal delivery was significantly higher than those in the control group. The incidence of macrosomia, rate of neonatal transfer to the NICU, and rate of neonatal hyperbilirubinemia were significantly lower in the study group than those in the control group. CONCLUSIONS: Individualized nutritional intervention for older pregnant women can effectively reduce the incidence of complications during pregnancy and childbirth and improve maternal and child outcomes.

Enones from Acid Fluorides and Vinyl Triflates by Reductive Nickel Catalysis.

A nickel-catalyzed reductive coupling between acid fluorides and vinyl triflates has been described. This method provides an efficient access to various enones and avoids the requirement for acyl or vinyl metallic reagents in the conventional approaches. The reaction proceeds with a broad range of acid fluorides and cyclic vinyl triflates, tolerating several functional groups. The utility of this synthetic method has been demonstrated by the late-stage modification of pharmaceuticals and biologically active natural compounds.

Differential T cell responses against DosR-associated antigen Rv2028c in BCG-vaccinated populations with tuberculosis infection.

The IFN-γ release assays (IGRAs) based on region of difference 1 (RD1) antigens have improved diagnosis of Mycobacterium tuberculosis (Mtb) infection. However, IGRAs with these antigens could not distinguish latent tuberculosis infection (LTBI) from active tuberculosis (ATB). DosR regulon genes are thought to be important for Mtb dormancy, and their products have higher immunogenicity in LTBI than ATB individuals, suggesting protective immunity mediated by DosR regulon-encoded antigens and potential utility of them for differential diagnostics of Mtb-infected populations or development of therapeutic vaccines against tuberculosis (TB). Among them, Rv2028c is a dormancy-related antigen that has demonstrated potential use in TB control, but its immunological characteristics in the BCG-vaccinated Chinese population are unknown. In this study, a total of 148 individuals, including 98 patients with ATB, 20 cases with LTBI and 30 healthy controls, were tested for Rv2028c-specific T cell responses by using an IFN-γ ELISA assay. The results showed that the T-cell responses in LTBI individuals were almost always higher than those in ATB patients, regardless of the site of infection or the results of bacteriological examination in the patients. This allowed for good differentiation between these two groups of Mtb-infected individuals even in the BCG-vaccinated high TB-incidence setting that pertains in China. In addition, the diagnostic efficacy for ATB was enhanced by combining the results from Rv2028c and RD1 antigen-based IFN-γ ELISA assays. In conclusion, Rv2028c-specific T-cell responses might contribute to natural protection against dormant Mtb infection, and the determination of these responses can aid discrimination between healthy LTBI individuals and ATB patients in the Mtb-infected populations.

The Profile of T Cell Responses in Bacille Calmette-Guérin-Primed Mice Boosted by a Novel Sendai Virus Vectored Anti-Tuberculosis Vaccine.

The kinds of vaccine-induced T cell responses that are beneficial for protection against Mycobacterium tuberculosis (Mtb) infection are not adequately defined. We had shown that a novel Sendai virus vectored vaccine, SeV85AB, was able to enhance immune protection induced by bacille Calmette-Guérin (BCG) in a prime-boost model. However, the profile of T cell responses boosted by SeV85AB was not determined. Herein, we show that the antigen-specific CD4+ and CD8+ T cell responses were both enhanced by the SeV85AB boost after BCG. Different profiles of antigen-specific po T cell subsets were induced in the local (lung) and systemic (spleen) sites. In the spleen, the CD4+ T cell responses that were enhanced by the SeV85AB boost were predominately IL-2 responses, whereas in the lung the greater increases were in IFN-γ- and TNF-α-producing CD4+ T cells; in CD8+ T cells, although IFN-γ was enhanced in both the spleen and lung, only IL-2+TNF-α+CD8+ T subset was boosted in the latter. After a challenge Mtb infection, there were significantly higher levels of recall IL-2 responses in T cells. In contrast, IFN-γ-producing cells were barely boosted by SeV85AB. After Mtb challenge a central memory phenotype of responding CD4+ T cells was a prominent feature in SeV85AB-boosted mice. Thus, our data strongly suggest that the enhanced immune protection induced by SeV85AB boosting was associated with establishment of an increased capacity to recall antigen-specific IL-2-mediated T cell responses and confirms this Sendai virus vector system as a promising candidate to be used in a heterologous prime-boost immunization regimen against TB.

Reductive coupling of benzyl oxalates with highly functionalized alkyl bromides by nickel catalysis.

Coupling reactions involving non-sulfonated C-O electrophiles provide a promising method for forming C-C bonds, but the incorporation of functionalized or secondary alkyl groups remains a challenge due to the requirement for well-defined alkylmetal species. In this study, we report a reductive nickel-catalyzed cross-coupling of benzyl oxalates with alkyl bromides, using oxalate as a new leaving group. A broad range of highly functionalized alkyl units (such as functional groups: alkyl chloride, alcohol, aldehyde, amine, amide, boronate ester, ether, ester, heterocycle, phosphonate, strained ring) were efficiently incorporated at the benzylic position. The utility of this synthetic method was further demonstrated by late-stage modification of complex bioactive compounds. Preliminary mechanistic experiments revealed that a radical process might be involved in the reaction.