High Prevalence and Risk Factors Associated with Vitamin D Deficiency Among Chinese Hospital Staff: A Cross-Sectional Study.

Purpose: To determine the current status of vitamin D status and the associated factors for its deficiency among Chinese hospital staff. Methods: The physical examination data of 2509 hospital staff members was analyzed alongside that of 1507 patients who visited the hospital during the corresponding period of the examination. Serum concentration of 25-hydroxyvitamin D (25(OH)D) were measured in the participants. The hospital staff also completed surveys about general information, laboratory examination, and occupational characteristics. Results: The median vitamin D status (serum 25(OH)D concentration) of the participants was 9.0 ng/mL, ranging from 6.5 to 44.7 ng/mL, and the prevalence of deficiency (<12.3 ng/mL) was 81.47% (2044/2509). The multivariable logistic regression revealed that nurses (OR = 1.54, 95% CI 1.09-2.19, p = 0.015), BMI below 18 (OR = 2.39, 95% CI 1.02-5.58, p = 0.045) associated with higher prevalence of vitamin D deficiency. In the contrast, age above 30 (OR = 0.69, 95% CI 0.53-0.91, p = 0.009) and a high level of uric acid (OR = 0.56, 95% CI 0.41-0.78, p = 0.001) associated with lower prevalence of vitamin D deficiency. The prevalence of vitamin D deficiency was higher among the hospital staff (81.47%) compared to the patients who visited the hospital during the same time period (65.69%). A substantial disparity was observed in the propensity score matching dataset (69.14% vs 79.94%, p < 0.001). Conclusion: Hospital staff are a high-risk group for vitamin D deficiency. Paying attention to vitamin D status and supplementation of this vitamin are pertinent aspects of hospital staff health care. Outdoor activities, vitamin D supplementation, and foods rich in vitamin D should be advocated.

A case of gaucher disease with a rare complication of gaucheroma and protein-losing enteropathy.

This case report describes a patient initially diagnosed with Gaucher disease (GD) with type I with homozygous mutation c.1448T > C p. (Leu483Pro) at age of 2, presenting with hepatosplenomegaly and cytopenia. Imiglucerase replacement therapy was initiated. At age 17, bilateral hearing loss developed, with subsequent Cranial MRI revealing thalamic damage, leading to a reclassification as type 3 GD. By age of 20, the patient presented with a range of symptoms, including abdominal pain, diarrhea, hypoproteinemia, multiple lymphadenopathy, edema, and Gaucher cell infiltration in the lymph nodes. Comprehensive diagnosis identifies Gaucher tumor and protein-losing enteropathy. Imiglucerase therapy at 90-120 U/kg every 2 weeks significantly improved clinical symptoms, emphasizing the importance of tailored interventions for managing GD manifestations.

Deconvoluting the Effect of Cell-Penetrating Peptides for Enhanced and Controlled Insertion of Large-Scale DNA Nanopores.

DNA nanopores have emerged as powerful tools for molecular sensing, but the efficient insertion of large DNA nanopores into lipid membranes remains challenging. In this study, we investigate the potential of cell-penetrating peptides (CPPs), specifically SynB1 and GALA, to enhance the insertion efficiency of large DNA nanopores. We constructed SynB1- or GALA-functionalized DNA nanopores with an 11 nm inner diameter and visualized and quantified their membrane insertion using a TIRF microscopy-based single-liposome assay. The results demonstrated that incorporating an increasing number of SynB1 or GALA peptides into the DNA nanopore significantly enhanced the membrane perforation. Kinetic analysis revealed that the DNA nanopore scaffold played a role in prearranging the CPPs, which facilitated membrane interaction and pore formation. Notably, the use of pH-responsive GALA peptides allowed highly efficient and pH-controlled insertion of large DNA pores. Furthermore, single-channel recording elucidated that the insertion process of single GALA-modified nanopores into planar lipid bilayers was dynamic, likely forming transient large toroidal pores. Overall, our study highlights the potential of CPPs as insertion enhancers for DNA nanopores, which opens avenues for improved molecule sensing and the controlled release of cargo molecules.

[Short-term Effect of Venetoclax Combined with Azacitidine and "7+3" Regimen in the Treatment of Newly Diagnosed Elder Patients with Acute Myeloid Leukemia].

OBJECTIVE: To compare the short-term effect and adverse reaction of venetoclax (VEN) combined with azacitidine (AZA) versus "7+3" regimen in newly diagnosed elder patients with acute myeloid leukemia (AML). METHODS: From January 2021 to January 2022, the clinical data of seventy-nine newly diagnosed elder patients with AML at the Second Hospital of Shanxi Medical University and the Shanxi Bethune Hospital were retrospectively analyzed, including VEN+AZA group (41 cases) and "7+3" group (38 cases). The propensity score matching(PSM) method was used to balance confounding factors， then response， overall survival(OS), progressionfree survival(PFS) and adverse reactions between the two groups were compared. RESULTS: The ORR of VEN+AZA group and "7+3" group was 68% and 84%, respectively, and the CRc was 64% and 72%, respectively, the differents were not statistically significant (P >0.05). In the VEN+AZA group, there were 5 non-remission (NR) patients, 4 with chromosome 7 abnormality (7q-/-7), and 1 with ETV6 gene mutation. Median followed-up time between the two groups was 8 months and 12 months, respectively, and the 6-months OS was 84% vs 92% (P =0.389), while 6-months PFS was 84% vs 92% (P =0.258). The main hematological adverse reactions in two groups were stage Ⅲ-Ⅳ myelosuppression, and the incidence rate was not statistically different(P >0.05). The median time of neutrophil recovery in two groups was 27(11-70) d, 25(14-61) d （P =0.161）, and platelet recovery was 27(11-75) d, 25(16-50) d （P =0.270）, respectively. The infection rate of VEN+AZA group was lower than that of "7+3" group (56% vs 88%, P =0.012）. The rate of lung infections of two groups was 36% and 64%, respectively, the difference was statistically significant (P =0.048). CONCLUSION: The short-term effect of VEN+AZA group and "7+3" regimens in eldrly AML patients are similar， but the VEN+AZA regimen had a lower incidence of infection. The presence of chromosome 7 abnormality（7q-/-7） may be a poor prognostic factor for elderly AML patients treated with VEN+AZA.

Molecular Diagnosis of Hemophilia A and Pathogenesis of Novel F8 Variants in Shanxi, China.

The aim of this study was to perform a molecular diagnosis of hemophilia A (HA) among patients in the Shanxi Province of China. Fifty-two HA patients were tested, including IVS22 (31 samples), IVS1 (3 samples), missense (11 samples), nonsense (3 samples), and 4 cases of frameshift (2 cases of deletion, 1 case of insertion, 1 case of single-base duplication). With the exception of the single-base G duplication variant (p.Ile1213Asnfs*28), this was the hotspot variant reported by research groups at an early stage. The remaining variants were found, for the first time, in the region. The missense variants p.Cys172Ser, p.Tyr404Ser, p.Asp1903Gly, and p.Ser2284Asn, the deletion variant p.Leu2249fs*9, and the insertion variant p.Pro2319fs*97 were novel variants. The application of next-generation sequencing (NGS) molecular diagnosis enriched the variant spectrum of HA, which is greatly significant for individualized genetic counseling, clinical diagnosis, and treatment. NGS and a variety of bioinformatics prediction methods can further analyze the impact of genetic variation on protein structure or function and lay the foundation to reveal the molecular pathogenic mechanism of novel variants.

[Impact of CSF3R Mutation on Treatment Response and Survival of Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the expression of CSF3R mutation in acute myeloid leukemia (AML) and analyze its clinical characteristics and prognosis. METHODS: A retrospective study was conducted in 212 patients with AML who were newly diagnosed in the Second Hospital of Shanxi Medical University from January 1th 2018 to June 30th 2021, including 22 patients with CSF3R mutations as mutation group and 190 patients with CSF3R wild type ï¼»66 cases of them were screened by propensity score matching (PSM), as control groupï¼½. The early efficacy and survival between the two groups were compared. RESULTS: The median age of patients in the mutation group was 50(17-73) years old, and the ratio of male to female was 1.2:1 The main types were AML with maturation (11 cases) and acute myelomonocytic leukemia (9 cases). Prognostic stratification was carried out according to the risk stratification system of the European leukemia network in 2017, with 16 cases (72.73%) in the middle and high-risk group. At the initial diagnosis, the median count of white blood cell (WBC) was 44.75(1.30-368.71)×109/L, among which 15 cases (68.18%) were >10×109/L, and the median count of platelet (PLT) was 24(4-55)×109/L. CSF3R T618I (68.18%) was a common mutation site, which had concomitant gene mutations, in which CEBPA mutation was the most common (10 cases, 45.45%), but only existed in CSF3R T618I mutation. The CR/CRi rate was 68.18% and 71.21% in the mutant group and the control group (P >0.05), the median over all survival time was 15 months and 9 months (P >0.05), and the median disease-free survival time was 8 months and 4 months (P >0.05), respectively. CONCLUSION: Most AML patients with CSF3R mutation are middle-aged patients, the main types are AML with maturation and acute myelomonocytic leukemia, and most of them have middle and high-risk prognosis. CSF3R mutation may not be an independent prognostic marker for newly diagnosed AML patients.

Specific Detection of Proteins by a Nanobody-Functionalized Nanopore Sensor.

Nanopores are label-free single-molecule analytical tools that show great potential for stochastic sensing of proteins. Here, we described a ClyA nanopore functionalized with different nanobodies through a 5-6 nm DNA linker at its periphery. Ty1, 2Rs15d, 2Rb17c, and nb22 nanobodies were employed to specifically recognize the large protein SARS-CoV-2 Spike, a medium-sized HER2 receptor, and the small protein murine urokinase-type plasminogen activator (muPA), respectively. The pores modified with Ty1, 2Rs15d, and 2Rb17c were capable of stochastic sensing of Spike protein and HER2 receptor, respectively, following a model where unbound nanobodies, facilitated by a DNA linker, move inside the nanopore and provoke reversible blockade events, whereas engagement with the large- and medium-sized proteins outside of the pore leads to a reduced dynamic movement of the nanobodies and an increased current through the open pore. Exploiting the multivalent interaction between trimeric Spike protein and multimerized Ty1 nanobodies enabled the detection of picomolar concentrations of Spike protein. In comparison, detection of the smaller muPA proteins follows a different model where muPA, complexing with the nb22, moves into the pore, generating larger blockage signals. Importantly, the components in blood did not affect the sensing performance of the nanobody-functionalized nanopore, which endows the pore with great potential for clinical detection of protein biomarkers.

[Analysis of F12 gene variants and molecular mechanisms in patients with coagulation factor â « deficiency].

OBJECTIVE: To analyze the sequence of the F12 gene and molecular mechanism for 20 patients with coagulation factor Ⅻ (FⅫ) deficiency. METHODS: The patients were selected from the outpatient department of the Second Hospital of Shanxi Medical University from July 2020 to January 2022. The activity of coagulation factor Ⅷ (FⅧ:C), factor Ⅸ (FⅨ:C), factor Ⅺ (FⅪ:C) and factor Ⅻ (FⅫ:C) were determined by using a one-stage clotting assay. All exons and 5' and 3' UTR of the F12 gene were analyzed by Sanger sequencing to detect the potential variants. Bioinformatic software was used to predict the pathogenicity of the variants, conservation of amino acids, and protein models. RESULTS: The FⅫ:C of the 20 patients has ranged from 0.07% to 20.10%, which was far below the reference values, whilst the other coagulation indexes were all normal. Sanger sequencing has identified genetic variants in 10 patients, including 4 with missense variants [c.820C>T (p.Arg274Cys), c.1561G>A (p.Glu521Lys), c.181T>C (p.Cys61Arg) and c.566.G>C (p.Cys189Ser)], 4 deletional variants c.303_304delCA(p.His101GlnfsX36), 1 insertional variant c.1093_1094insC (p.Lys365GlnfsX69) and 1 nonsense variant c.1763C>A (p.Ser588*). The remaining 10 patients only harbored the 46C/T variant. The heterozygous c.820C>T(p.Arg274Cys) missense variant in patient 1 and the homozygous c.1763C>A (p.Ser588*) nonsense variant in patient 2 were not included in the ClinVar and the Human Gene Mutation Database. Bioinformatic analysis predicted that both variants were pathogenic, and the corresponding amino acids are highly conserved. The protein prediction models suggested that the c.820C>T (p.Arg274Cys) variant may affect the stability of the secondary structure of FⅫ protein by disrupting the original hydrogen bonding force and truncating the side chain, leading to changes in the vital domain. c.1763C>A (p.Ser588*) may produce a truncated C-terminus which may alter the spatial conformation of the protein domain and affect the serine protease cleavage site, resulting in extremely reduced FⅫ:C. CONCLUSION: Among individuals with low low FⅫ:C detected by one-stage clotting assay, 50% have harbored variants of the F12 gene, among which the c.820C>T and c.1763C>A were novel variants underlying the reduced coagulating factor FⅫ.

[Correlation Analysis of Fâ §Gene Mutation and the Production of Fâ § Inhibitor with Severe Hemophilia A Patients in a Single Medical Center].

OBJECTIVE: To investigate the relationship between the type of FⅧgene mutation and the development of FⅧ inhibitors in patients with severe haemophilia A (HA). METHODS: The medical records of 172 patients with severe hemophilia A from January 2009 to September 2020 were reviewed. The types of FⅧgene mutations and the production of factor Ⅷ inhibitors were collected and divided into high-risk mutation group ( intron 1 inversions, large deletions, nonsense mutations), low-risk mutation group (missense mutations, small deletions and insertions, splice site mutations) and intron 22 inversions group. The correlation of FⅧgenotype and the production of FⅧ inhibitors in patients with HA were analyzed. RESULTS: Among 172 patients with severe HA, 21 cases(12.21%) developed FⅧ inhibitors. The cumulative incidence of FⅧ inhibitor development was 32%(10/31) in high risk group (75% patients with large deletions, 43% patients with intron 1 inversions, 20% patients with nonsense mutations) and 5%(2/43) in low risk group(6% patients with missense mutations, 5% patients with small deletions or insertions and 0% patient with a splice site mutation) and 9%(9/98) in intron 22 inversions group. Compared with the risk of FⅧ inhibitor development in intron 22 inversions group, the risk of FⅧ inhibitor development in high risk group was higher (OR＝4.7, 95% CI： 1.7-13.0), the risk of FⅧ inhibitor development in low risk group was equal (OR＝0.5, 95% CI： 0.1-2.3). Compared with the risk of inhibitor development in low risk group, the risk of FⅧ inhibitor development in high risk group was higher (OR＝9.8, 95% CI： 2.0-48.7). CONCLUSION: Gene mutations of patients with severe HA in high-risk group which include intron 1 inversions, large deletions, nonsense mutations are a risk factor for FⅧ inhibitor production.

Exosomal MiR-4261 mediates calcium overload in RBCs by downregulating the expression of ATP2B4 in multiple myeloma.

Background: Hypercalcemia induced by multiple myeloma (MM) affects the biological functions of excitable and non-excitable cells. However, red blood cells (RBCs) regulatory effect on calcium in hypercalcemia is still not fully understood. Methods: A total of 113 patients with MM osteolytic lesions were studied retrospectively. Flow cytometry and atomic absorption spectroscopy were used to detect calcium content. Immunofluorescence and Western blotting were used to investigate protein expression. GEO and miRNA databases were used to screen miRNAs. Exosomal miR-4261 migration was investigated by Transwell assay. Dual-luciferase assays confirmed the targeting relationship between miR-4261 and ATP2B4. An RBC oxidative stress model was constructed, and Omega-Agatoxin IVA was used to study the role of plasma membrane Ca2+-ATPase 4 (PMCA4) in RBCs. Results: The results showed that MM RBCs had calcium overload, and serum calcium levels increased as the number of RBCs decreased. The expression of PMCA4 in MM RBCs was significantly lower than in normal RBCs. The exosomal miR-4261 produced by MM cells could be transferred to RBCs to downregulate the expression of ATP2B4. Conclusions: Studies have confirmed that RBCs experience calcium overload in MM with osteolytic lesions, which is related to the downregulation of ATP2B4 by MM exosomal miR-4261.

Generation of iPSC line from urine cells of hemophilia A with F8 (p. R814X) mutation.

The lack of coagulation factor VIII in patient with nonsense mutation hemophilia A leads to varying degrees of bleeding symptoms, and long-term use of alternative therapies can produce inhibitors that affect the efficacy. In this study, human induced pluripotent stem cells (iPSCs) of hemophilia A were generated by reprogramming of urine cells. Human urine cells (HUCs) were isolated by collecting patients' mid-stream urine, and cultured to good state in urine medium. Then, the HUCs were transfected with PEP4-EO2S-ET2K and pCEP4-M2L, and iPSCs were obtained in the medium without trophoblast cells and the composition was determined. Finally, alkaline phosphatase staining, karyotype analysis, immunofluorescence staining and teratoma were used to verify that we successfully reprogrammed hemophilia A-specific human induced pluripotent stem cells from patients' urine cells, providing a safe and effective cell model for the study of molecular mechanism and related treatment of hemophilia.

Generation an induced pluripotent stem cell line SXMUi001-A derived from a hemophilia B patient carries variant F9 c.223C＞T(p.R75X).

Hemophilia B (HB) is an X chromosome-linked recessive disorder caused by a quantitative or qualitative defect of coagulation zymogen factor IX. In this study, urine cells were collected from a patient with HB who carries variant F9 c.223C > T (p.R75X), and reprogrammed into induced pluripotent stem cells (iPSCs) using the reprogramming factors, OCT4, SOX2, m-MYC, and KLF4. The HB-iPSC line (SXMUi001-A) has characteristics similar to human embryonic stem cell, namely, pluripotency and the potential to differentiate into three germ layers. This cell line can be used as a disease model for exploring the molecular mechanism and readthrough treatment of HB.

Early platelet elevation after complete remission as a prognostic marker of favourable outcomes in favourable- and intermediate-risk acute myeloid leukaemia: A retrospective study.

OBJECTIVES: Platelet (PLT) recovery after chemotherapy is associated with the prognosis of patients with acute myeloid leukaemia (AML). This study aimed to explore the prognostic significance of early high PLT values in patients with de novo non-M3 AML who achieved first complete remission (CR). METHODS: A total of 206 patients with de novo non-M3 AML were analysed in this retrospective study. A receiver operating characteristic (ROC) curve was used to determine the optimal PLT cut-off. The overall survival (OS) and relapse-free survival (RFS) were assessed using Kaplan-Meier and Cox regression analyses. RESULTS: 312×109 /L was confined as the cut-off of the PLT count. The estimated 3-year OS of patients with high PLT was higher than that of their counterparts (72.3% vs. 34.6%, p = 0.001). In subgroup analysis, patients with high PLT had better OS in the favourable- and intermediate-risk (non-adverse-risk) AML (p = 0.001). The estimated 3-year RFS for the high and low PLT groups was 75.1% and 45.7% respectively (p = 0.078). Multivariate analyses revealed that high PLT count was an independent favourable variable for OS (HR = 0.264, p < 0.001) and RFS (HR = 0.375, p = 0.011) in the non-adverse-risk group. CONCLUSION: Our results showed that early high PLT count recovery at first CR in non-adverse-risk AML patients is a positive prognostic marker for survival outcomes.

Compound heterozygous p.L483P and p.S310G mutations in GBA1 cause type 1 adult Gaucher disease: A case report.

BACKGROUND: Gaucher disease (GD) is caused by a GBA1 gene mutation that leads to decreased acid ß-glucosidase activity [glucocerebrosidase (GCase)]. This study aimed to identify and characterise compound heterozygous mutations in GBA1 in a patient with type 1 GD. CASE SUMMARY: Here, we report a rare adult-onset type 1 GD in a 46-year-old female patient with clinical manifestations of giant spleen, thrombocytopenia, and bone pain, diagnosed by enzymatic and genetic testing. Enzymology and whole exome sequencing revealed heterozygous missense mutations in exon 10 c.1448T>C (p.L483P) and exon 7 c.928A>G (p.S310G) of GBA1. The latter was first reported in patients with GD. Structural modelling showed that p.S310G and p.L483P were distant from the GCase active site. The p.S310G mutation in domain 1 may decrease stability between the α2 and α3 helices of GBA1. The p.L483P mutation in domain 2 reduced the van der Waals force of the side chain and disrupted the C-terminal ß-sheet. The patient was treated with imiglucerase replacement therapy, and her condition was stable. CONCLUSION: The p.L483P/p.S310G novel compound heterozygous mutation underlies type 1 GD and likely affects GCase protein function. This is the first description of p.S310G being associated with mild type 1 GD in the context of a coinherited p.L483P mutation.

[Altered Splicing in Stable Cell Strains Expressing Mini-hF9 Gene with Nonsense Mutation].

OBJECTIVE: To investigate the molecular mechanism in stable cell strains expressing Mini-hF9 gene with nonsense mutation. METHODS: Mini-hF9 gene and its nonsense mutants were transfected into HeLa cells independently, and stable cell strains were obtained after G418 resistance screening and monoclonal transformation. The altered splicing and protein expression of mRNA in Mini-hF9 gene in stable cell strains were detected by using RT-PCR and Western blot. RESULTS: The wild type and nonsense mutated human coagulation factor IX stable cell strains were constructed successfully, which were named HeLa-F9-WT, HeLa-F9-M1 and HeLa-F9-M2. Only normal splicing Norm was detected in the wild-type cell strain HeLa-F9-WT; Norm and Alt-S1 splicing were detected in HeLa-F9-M1; while Norm, Alt-S1 and Alt-S2 splicing were detected in HeLa-F9-M2. CONCLUSION: The nonsense associated altered splicing (NAS) pathway, which generated alternately spliced transcripts, might be triggered in coagulation factor IX gene with nonsense mutation.

Real-time sensing of neurotransmitters by functionalized nanopores embedded in a single live cell.

Interface between neuron cells and biomaterials is the key to real-time sensing, transmitting and manipulating of neuron activities, which are the long-term pursue of scientists and gain intense research focus recently. It is of great interest to develop a sensor with exquisite sensitivity and excellent selectivity for real-time monitoring neurotransmitters transport through single live cell. Sensing techniques including electrode-based methods, optogenetics, and nanowire cell penetration systems have been developed to monitor the neuron activities. However, their biocompatibilities remain a challenge. Protein nanopores with membrane compatibility and lumen tunability provide real-time, single-molecule sensitivities for biosensing of DNA, RNA, peptides and small molecules. In this study, an engineered protein nanopore MspA (Mycobacterium smegmatis porin A) through site-directed mutation with histidine selectively bind with Cu2+ in its internal lumen. Chelation of neurotransmitters such as L-glutamate (L-Glu), dopamine (DA) and norepinephrine (NE) with the Cu2+ creates specific current signals, showing different transient current blockade and dwell time in single channel electrophysiological recording. Furthermore, the functionalized M2MspA-N91H nanopores have been embedded in live HEK293T cell membrane for real-time, in situ monitoring of extracellular L-glutamate translocating through the nanopore. This biomimetic neurotransmitter nanopore has provided a new platform for future development of neuron sensors, drug carrier and artificial synapse.

Multimode detection of ß-glycosidase and pathogenic bacteria via cation exchange assisted signal amplification.

A rapid strategy for the ß-glycosidase (ß-Gal) and Escherichia coli (E. coli) sensing is presented, which is based on selective recognition reactions of QDs using visualization/fluorescence (FL)/atomic fluorescence spectrometry (AFS)/inductively coupled plasma mass spectrometry (ICP-MS) multimode assay. CdTe QDs can selectively recognize Ag+ and Ag NPs with a cation exchange reaction (CER) where Ag+ triggers the release of Cd2+ and quenches the fluorescence signal of QDs. Taking advantage of the fact that ß-Gal can hydrolyze 4-Aminophenyl ß-D-galactopyranoside (PAPG) to produce p-aminophenol (PAP), which has the ability to reduce Ag+ to form Ag NPs. The ß-Gal can be easily detected by visualization or FL in a turn-on manner. Furthermore, combining with the selective separation of Cd2+ by filter membrane, AFS and ICP-MS with higher sensitivity were used for the determination of the enzyme. Under optimized conditions, the system limits of detections (LODs) were 0.01 U/L, 0.03 mU/L, and 0.02 mU/L using FL, AFS, and ICP-MS as the detector, respectively. The relative standard deviations (RSDs, n = 7) for 0.1 U/L ß-Gal were 2.2, 2.0, and 1.3% using FL/AFS/ICP-MS as the detector, respectively. And 0.1 U/L of ß-Gal can be discriminated from the blank solution with the naked eye. In addition, given that the ß-Gal can serve as an indicator of E. coli, we have successfully applied this strategy for the detection of E. coli with a LOD of 25 CFU/mL. Application of the method was demonstrated by analyzing human urine samples and milk samples for ultra-trace detection of E. coli. Graphical abstract The CVG-AFS/ICP-MS/visual/FL multimode ß-Gal and E.coli detection via CER.

Detection of Circulating Tumor Cells in Breast Cancer Patients by Nanopore Sensing with Aptamer-Mediated Amplification.

Circulating tumor cells (CTCs) have been utilized in the diagnosis and prognosis of tumor. However, the CTC concentration is extremely low to be detected in peripheral blood. Many existing methods suffer from either expensive labeling or complex operation. In this study, we constructed a label- and enzyme-free and sensitive method to detect the breast cancer CTCs. First of all, a probe containing a breast cancer cell-specific aptamer and a complementary single-stranded DNA (trigger DNA P1) were designed. When the target cells are present, the aptamer binds to the CTCs and releases P1 which triggers the strand displacement amplification. This process generates three-way junction structure DNA, the specific translocation signals of which are identified by nanopore assay. The detection limit of tumor cells is 5 in the current experimental setup and can be further reduced. Furthermore, the method is demonstrated in a clinical sample test with high recovery rate and accuracy. Our results suggest that this method could be applied to early diagnosis of metastatic recurrence and prognosis determination.