Transporter Associated with Antigen Processing 1 Gene Polymorphisms Increase the Susceptibility to Tuberculosis.

Purpose: Tuberculosis (TB) is known to result from a complex interaction between the host immune response and Mycobacterium infection. The transporter associated with antigen processing (TAP) plays an important role in the processing and presentation pathways for the Mycobacterium tuberculosis (M. tb) antigen. To investigate the possible association of the TAP1 and TAP2 genes with TB. Patients and Methods: A total of 449 TB patients and 435 control subjects were included in this study, and single nucleotide polymorphisms (SNPs) in the TAP gene, as well as TAP1 and TAP2 alleles, were genotyped. Results: TAP gene association analysis of TB diseases showed that rs41551515-T in the TAP1 gene was significantly associated with susceptibility to TB (P=7.96E-04, OR=4.124, 95% CI: 1.683-10.102), especially pulmonary TB (PTB, P=6.84E-04, OR=4.350, 95% CI: 1.727-10.945), and the combination of rs1057141-T-rs1135216-C in the TAP1 gene significantly increased the risk of TB susceptibility (P=5.51E-05, OR=10.899, 95% CI: 2.555-46.493). Five novel TAP1 alleles were detected in Yunnan Han people, and the allele frequency of TAP1*unknown_3 (rs41555220-rs41549617-rs1057141-rs1135216-rs1057149-rs41551515: C-A-T-C-C-T) was notably increased in all TB patients, including in the PTB and EPTB subgroups, and was significantly associated with the risk of susceptibility to TB. However, no association between the TAP2 gene and TB was found in this study. Conclusion: Host genetic variants of rs41551515-T and the combination rs1057141-T-rs1135216-C, as well as TAP1*unknown_3 may play a critical role in susceptibility to TB disease.

Changing Kindergarten Teachers' Mindsets Toward Children to Overcome Compassion Fatigue.

Introduction: Kindergarten teachers who empathize with toddlers experience a great risk of burnout and emotional disturbance. This is referred to as compassion fatigue, in which teachers' empathy experience is reduced. This study proposed a moderated mediation model to identify the risks of compassion fatigue and its protective factors for developing evidence-based clinical interventions. Methods: In this cross-sectional study, self-report measures were administered to 1049 kindergarten teachers to observe their mindsets toward children, motivation for teacher empathy, job stress, social support, and compassion fatigue. The PROCESS macro (SPSS 23.0) was used to assess the moderated mediation model. Results: The results demonstrated that motivation for teacher empathy mediated the negative relationship between kindergarten teachers' mindsets toward children and compassion fatigue. Moreover, job stress and social support moderated the relationship between kindergarten teachers' mindsets toward children and motivation for teacher empathy. However, this effect was not observed in the negative relationship between kindergarten teachers' mindsets toward children and compassion fatigue. Conclusion: The proposed moderated mediation model was found to be valid. Furthermore, the study findings have practical implications for developing evidence-based interventions for addressing kindergarten teachers' compassion fatigue.

Purine metabolites promote ectopic new bone formation in ankylosing spondylitis.

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease that mainly affects the axial skeleton, whose typical features are inflammatory back pain, bone structural damage and pathological new bone formation. The pathology of ectopic new bone formation is still little known. In this study, we found increased purine metabolites in plasma of patients with AS. Similarly, metabolome analysis indicated increased purine metabolites in both serum of CD4-Cre; Ptpn11fl/fl and SHP2-deficient chondrocytes. SHP2-deficient chondrocytes promoted the growth of wild type chondrocytes and differentiation of osteoblasts in CD4-Cre; Ptpn11fl/fl mice, which spontaneously developed AS-like bone disease. Purine metabolites, along with PTHrP derived from SHP2-deficient chondrocytes, accelerated the growth of chondrocytes and ectopic new bone formation through PKA/CREB signaling. Moreover, Suramin, a purinergic receptor antagonist, suppressed pathological new bone formation in AS-like bone disease. Overall, these results highlight the potential role of targeting purinergic signaling in retarding ectopic new bone formation in AS.

Establishment and Validation of a Ferroptosis-Related Long Non-Coding RNA Signature for Predicting the Prognosis of Stomach Adenocarcinoma.

Background: Ferroptosis is a form of regulated cell death that follows cell membrane damage and mostly depends on iron-mediated oxidative. Long non-coding RNAs (LncRNAs) are associated with the development of a variety of tumors. Till date, LncRNAs have been reported to intervene in ferroptosis. Therefore, we intended to provide a prognostic ferroptosis-related-lncRNA signature in stomach adenocarcinoma (STAD). Methods: We downloaded ferroptosis-related genes from the FerrDb database and RNA sequencing data and clinicopathological characteristics from The Cancer Genome Atlas. Gene differential expression analysis was performed using the "limma" package. We used Cox regression analysis to determine the ferroptosis-related lncRNAs signature with the lowest AIC value. The Kaplan-Meier curve, ROC curve, and nomogram were used to evaluate the prognostic value of the risk score. Gene set enrichment analysis (GSEA) was used to explore the biologic functions of the three ferroptosis-related lncRNAs. LINC01615 expression in gastric cancer cell lines and tissues was measured by real-time PCR. A nuclear-cytoplasmic fractionation assay was used to analyze the subcellular localization for LINC01615. Furthermore, we used bioinformatics to predict potential target microRNAs (miRNAs) of LINC01615 and their target ferroptosis-related mRNAs. Results: Three ferroptosis-related-lncRNA signatures (AP000695.2, AL365181.3, and LINC01615) were identified, and then Kaplan-Meier, Cox regression analyses, and ROC curve confirmed that the ferroptosis-related-lncRNA model could predict the prognosis of STAD. The GSEA indicated that the three ferroptosis-related lncRNAs might be related to the extracellular matrix and cellular activities. LINC01615 is highly expressed in gastric cancer cell lines and tissues. A nuclear-cytoplasmic fractionation assay confirmed that in gastric cancer cell lines, most LINC01615 was enriched in the cytoplasm. Bioinformatics further predicts four potential target miRNAs of LINC01615 and then figured out 26 target ferroptosis-related mRNAs. Conclusion: We established a three-ferroptosis-related-lncRNA model (AP000695.2, AL365181.3, and LINC01615) that can predict the prognosis of STAD patients. We also expected to provide a promising target for LINC01615 for research in the future, which was highly expressed in gastric cancer and cell lines and acted as a ceRNA to get involved in ferroptosis.

Chromium Oxide Nanoparticle Impaired Osteogenesis and Cellular Response to Mechanical Stimulus.

BACKGROUND: Release of metallic wear particles from hip replacement implants is closely associated with aseptic loosening that affects the functionality and survivorship of the prostheses. Chromium oxide nanoparticles (CrNPs) are the dominant form of the wear particles found in the periprosthetic tissues. Whether CrNPs play a role in the clinically observed particle-induced osteolysis, tissue inflammatory reactions and functional activities of human mesenchymal stem cells (MSCs) remain unknown. METHODS: A tibia-defect rat model, cytotoxicity assays and flow cytometry were applied to study the effect of CrNPs on MSCs survival and macrophage inflammatory response. Also, oscillatory fluid flow stimulation was used to analyse the osteogenic differentiation of MSCs while treated by CrNPs. In addition, the influence of CrNPs on MSC biomechanical properties was determined via atomic force microscope (AFM) and fluorescence microscopy. RESULTS: It was found that implantation of CrNPs significantly decreased bone formation in vivo. CrNPs had no obvious effects on inflammatory cytokines release of U937 macrophages. Additionally, CrNPs did not interfere with MSCs osteogenic differentiation under static culture. However, the upregulated osteogenic differentiation of MSCs due to fluid flow stimulation was reduced by CrNPs in a dose-dependent manner. Moreover, osteogenic gene expression of OPN, Cox2 and Rnux2 after mechanical stimulation was also decreased by CrNPs treatments. Furthermore, cell elasticity and adhesion force of MSCs were affected by CrNPs over 3 days of exposure. We further verified that these effects of CrNPs could be associated with its interruption on cell mechanical properties. CONCLUSION: The results demonstrated that CrNPs impaired cellular response to mechanical stimulus and osteogenesis without noticeable effects on the survival of the human MSCs.

Extracellular vesicle-mediated regulation of tumor angiogenesis- implications for anti-angiogenesis therapy.

Angiogenesis plays an important role in tumour progression. However, anti-angiogenesis therapy of inhibiting pro-angiogenic factors failed to meet expectations in certain types of tumour in clinical trials. Recent studies reveal that tumour-derived extracellular vesicles (EVs) are essential in tumour angiogenesis and anti-angiogenesis drug resistance. This function has most commonly been attributed to EV contents including proteins and non-coding RNAs. Here, we summarize the recent findings of tumour-derived EV contents associated with regulating angiogenesis and illustrate the underlying mechanisms. In addition, the roles of EVs in tumour microenvironmental cells are also illustrated with a focus on how EVs participate in cell-cell communication, contributing to tumour-mediated angiogenesis. It will help offer new perspectives on developing targets of anti-angiogenesis drugs and improve the efficacy of anti-angiogenesis therapies based on tumour-derived EVs.

Gastric cancer-secreted exosomal X26nt increases angiogenesis and vascular permeability by targeting VE-cadherin.

Angiogenesis is closely associated with tumorigenesis, invasion, and metastasis by providing oxygen and nutrients. Recently, increasing evidence indicates that cancer-derived exosomes which contain proteins, coding, and noncoding RNAs (ncRNAs) were shown to have proangiogenic function in cancer. A 26-nt-long ncRNA (X26nt) is generated in the process of inositol-requiring enzyme 1 alpha (IRE1α)-induced unspliced XBP1 splicing. However, the role of X26nt in the angiogenesis of gastric cancer (GC) remains largely unknown. In the present study, we found that X26nt was significantly elevated in GC and GC exosomes. Then, we verified that X26nt could be delivered into human umbilical vein endothelial cells (HUVECs) via GC cell exosomes and promote the proliferation, migration, and tube formation of HUVECs. We revealed that exosomal X26nt decreased vascular endothelial cadherin (VE-cadherin) by directly combining the 3'UTR of VE-cadherin mRNA in HUVECs, thereby increasing vascular permeability. We further demonstrated that X26nt accelerates the tumor growth and angiogenesis in a mouse subcutaneous tumor model. Our findings investigate a unique intercellular communication mediated by cancer-derived exosomes and reveal a novel mechanism of exosomal X26nt in the regulation of tumor vasculature.

Polymorphisms in ERAP1 and ERAP2 Genes Are Associated With Tuberculosis in the Han Chinese.

Single nucleotide polymorphisms (SNPs) in the endoplasmic reticulum aminopeptidase (ERAP1 and ERAP2) genes are associated with the pathogenesis of bacterial and viral infections. To search for the variations in the ERAP1 and ERAP2 genes associated with tuberculosis (TB), 449 TB cases and 435 healthy individuals of the Han population in the Yunnan province of China were included in the present study. Eleven SNPs of ERAPs were genotyped using the SNaPshot SNP assay. Allelic, genotypic, and haplotypic association analyses were performed between the TB and control groups. Furthermore, stratification analyses among pulmonary TB (PTB), extrapulmonary TB (EPTB), and healthy controls; and initial treatment TB (ITTB), retreatment TB (RTB), and healthy controls were also performed. The TT genotype of rs26618 in ERAP1 exhibited a protective factor for TB, compared with the role of the CC/CT genotype (P = 0.003; OR = 1.490, 95% CI: 1.140-1.940). In ERAP2, the frequency of the G allele of rs2549782 was higher in the case group than in the control group (0.491 vs. 0.417, P = 0.002, OR = 1.350, 95% CI: 1.118-1.631), and the TT genotype exhibited a protective factor for TB, compared with the role of the GG/GT genotype (P = 0.001; OR = 1.650, 95% CI: 1.230-2.220). The frequency of the C allele of rs1056893 was higher in the case group than in the control group (0.468 vs. 0.394, P = 0.002, OR = 1.350, 95% CI: 1.118-1.631), and the genotype exhibited a difference in the log-additive model (P = 0.002; OR = 1.350, 95% CI: 1.120-1.630). The frequencies of the haplotype rs27037-rs27044-s30187-rs26618-rs26653-rs3734016-GCCCGC in ERAP1 (0.290 vs. 0.240, P-adj = 0.028, OR = 1.320, 95% CI: 1.063-1.638) and the haplotypes rs2549782-rs2248374-rs2287988-rs1056893-GTAGC in ERAP2 (0.446 vs. 0.348, P-adj = 4.80E-05, OR = 1.510, 95% CI: 1.246-1.829) was higher in the TB groups, while the frequencies of the haplotypes rs2549782-rs2248374-rs2287988-rs1056893-TAGAT (0.478 vs. 0.539, P-adj = 0.020, OR = 0.782, 95% CI: 0.649-0.943) were lower in the TB groups. The allelic and genotypic associations were also investigated in the subsequent stratification between the PTB, EPTB and control groups as well as between the ITTB, RTB, and control groups. In conclusion, variations in ERAP1 and ERAP2 genes were identified to be associated with TB in the Han Chinese population.

CCR5 Promoter Polymorphisms Associated With Pulmonary Tuberculosis in a Chinese Han Population.

Background: Tuberculosis (TB), an infectious disease caused by Mycobacterium tuberculosis, is a major public health concern. Chemokines and their receptors, such as RANTES, CXCR3, and CCR5, have been reported to play important roles in cell activation and migration in immune responses against TB infection. Methods: To understand the correlations involving CCR5 gene variations, M. tuberculosis infection, and TB disease progression, a case-control study comprising 450 patients with TB and 306 healthy controls from a Chinese Han population was conducted, along with the detection of polymorphisms in the CCR5 promoter using a sequencing method. Results: After adjustment for age and gender, the results of logistic analysis indicated that the frequency of rs2734648-G was significantly higher in the TB patient group (P = 0.002, OR = 1.38, 95% CI: 1.123-1.696); meanwhile, rs2734648-GG showed notable susceptibility to TB (P = 6.32E-06, OR = 2.173, 95% CI: 1.546-3.056 in a recessive model). The genotypic frequency of rs1799987 also varied between the TB and control groups (P = 0.008). In stratified analysis, rs2734648-GG significantly increased susceptibility to pulmonary TB in a recessive model (P < 0.0001, OR = 2.382, 95% CI: 1.663-3.413), and the rs2734648-G allele significantly increased susceptibility to TB recurrence in a dominant model (P = 0.0032, OR = 1.936, 95% CI: 1.221-3.068), whereas rs1799987-AA was associated with susceptibility to pulmonary TB (P = 0.0078, OR = 1.678, 95% CI: 1.141-2.495 in a recessive model) but not with extra-pulmonary TB and TB recurrence. A haplotype constructed with the major alleles of the eight SNPs in the CCR5 promoter (rs2227010-rs2856758-rs2734648-rs1799987-rs1799988-rs41469351-rs1800023-rs1800024: A-A-G-G-T-C-G-C) exhibited extraordinarily increased risk of susceptibility to TB and pulmonary TB (P = 6.33E-11, OR = 24.887, 95% CI: 6.081-101.841). Conclusion: In conclusion, CCR5 promoter polymorphisms were found to be associated with pulmonary TB and TB progression in Chinese Han people.

Human leucocyte antigen but not KIR alleles and haplotypes associated with chronic HCV infection in a Chinese Han population.

The host immune system plays a key role in the elimination of infected cells which depend on killer-cell immunoglobulin-like receptors (KIR), human leucocyte antigen (HLA) class I molecules and their combinations. To evaluate the roles of HLAclass I, KIR genes and their combination in Chronic hepatitis C virus (HCV) infection (CHC), a total of 301 CHCs and 239 controls in a Chinese Han population were included for HLA and KIR genotyping using next-generation sequencing and multiplex PCR sequence-specific priming, respectively. The allele frequency of HLA-C*08:01 was significantly higher in the CHCs than that of the controls (0.088 vs. 0.040, OR = 2.332, 95%CI: 1.361-3.996, p = 0.022), while the frequencies of B*13:01 (0.032 vs. 0.084, OR = 0.357, 95%CI: 0.204-0.625, p = 0.009) and C*08:04 (0.008 vs. 0.038, OR = 0.214, 95%CI: 0.079-0.581, p = 0.022) were significantly lower in the CHCs. The frequencies of haplotype A*11:01-C*08:01 were higher in the CHCs (0.058 vs. 0.019, OR = 3.096, 95%CI: 1.486-6.452, p = 0.026), while haplotype B*13:01-C*03:04 were lower in the CHCs compared to the controls (0.028 vs. 0.071, OR = 0.377, 95%CI: 0.207-0.685, p = 0.012). No association of CHC with KIR genes, genotypes, or haplotypes, as well as HLA/KIR combinations was observed. Our results indicated that HLA-C*08:01 was a risk factor for CHC, while HLA-C*08:04 and HLA-B*13:01 were protective factors against CHC. Haplotypes HLA-A*11:01-C*08:01 could increase susceptibility to CHC, while HLA-B*13:01-C*03:04 could be protective against CHC in the Chinese Han population.

Risk analysis and assessment based on Sigma metrics and intended use.

INTRODUCTION: In order to ensure the quality in clinical laboratories and meet the low risk requirements of patients and clinicians, a risk analysis and assessment model based on Sigma metrics and intended use was constructed, based on which differential sigma performance (σ) expectations of 42 analytes were developed. MATERIALS AND METHODS: Failure mode and effects analysis was applied to produce an analytic risk rating based on three factors, each test of which was graded as follows: 1) Sigma metrics; 2) the severity of harm; 3) intended use. By multiplying the score of Sigma metrics by the score of severity of harm by the score of intended use, each was assigned a typical risk priority number (RPN), with RPN ≤ 25 rated as low risk. Low risk was defined as acceptable standards; the sigma performance expectations were calculated. RESULTS: Among the 42 analytes, tests with σ ≥ 6, 5 ≤ σ < 6, 4 ≤ σ < 5, 3 ≤ σ < 4, σ < 3 were 21, 5, 5, 6, and 5, respectively; there were 7 high-risk tests, 8 of them medium risk tests. According to the risk assessment conclusion, 13 tests had sigma performance expectations ≥ 6; 15 test items had sigma performance expectations ≥ 5, while 3 test items had sigma performance expectations ≥ 4; 11 test items had sigma performance expectations ≥ 3. CONCLUSIONS: Constructing the risk analysis and assessment model based on Sigma metrics and intended use will help clinical laboratories to identify the high-risk tests more objectively and comprehensively. Such model can also be used to establish the sigma performance expectations and meet the low risk requirements of patients and clinicians.

Assessment of HCV genotypes in Yunnan Province of Southwest China.

Recently, we reported that the frequency of hepatitis C virus (HCV) genotypes and subtypes has rapidly changed among intravenous drug users (IDUs) in Yunnan Province over the last 5 years; this is especially true for subtype 6a which has increased in frequency from 5 to 15%. Here, we assessed 120 HCV-positive plasma samples from the general population (GP). HCV NS5B fragments were amplified and sequenced by PCR. We identified four HCV genotypes (1, 2, 3 and 6) and seven HCV subtypes (1b, 2a, 3a, 3b, 6a, 6n, and 6k) in this population. Genotype 3 was predominant, with a distribution frequency of 0.484, followed by genotype 1 (0.283), genotype 6 (0.133) and genotype 2 (0.100). HCV subtypes 3b (frequency 0.292) and 1b (frequency 0.283) were the most common subtypes. A comparison of the current data with previous results reported for IDUs showed that the distribution frequencies of genotypes 1, 2 and 6 were significantly different between patients in the GP and IDUs (P < 0.05). Among the HCV subtypes, the distribution frequencies of 1b, 2a, 6a, and 6n were significantly different between patients in the GP and IDU groups (P < 0.05). Moreover, Phylogenetic analyses showed that HCV subtype 6a strains isolated from IDUs and the GP were intermixed and not separately clustered. HCV subtype 6a was predominant not only among IDUs but also among those in the GP in the Guangdong Province and Vietnam. However, HCV subtype 6a was predominant only among IDUs and not among those in the GP in the Yunnan and Guangxi Provinces. Our results indicate that the HCV subtype 6a could rapidly spread across China.

[Clinical features, diagnosis and treatment of 5 cases of primary pneumonic plague in Tibet in 2010].

OBJECTIVE: To explore the clinical manifestations, the feature of chest X-ray, the clinical outcome, and the clinical treatments of severe pneumonic plague. METHODS: We observed the clinical course of primary pneumonic plague in 5 patients, who infected Yersinia pestis in Tibet during September 2010, including manifestations of chest X-ray, the antibiotic therapy, respiratory support and the prognosis. RESULTS: All of the 5 patients presented with high fever, bloody sputum and difficulty breathing. The chest X-ray showed signs consistent with necrotizing inflammation with multiple lobar involvement. Mass-like lesions might coalesce, and the "white lung" sign might appear. Three out of the 5 patients presented with hypoxemia. The results of reverse indirect hemagglutination assay (RIHA) in these patients were positive on the second day of the illness onset. All of these patients recovered after antibiotic therapy and other treatments. However, the absorption of lung lesions was very slow. CONCLUSIONS: Patients infected with primary pneumonic plague presented with rapid onset high fever and hemoptysis, and the lung injury was very severe. The positive result of RIHA was useful for early diagnosis of plague. Streptomycin should be the first choice for Yersinia pestis infection, but its optimal dose needed further study. Fluoroquinolones can be used as combination with Streptomycin. Nutritional support and symptomatic treatment, as well as non-invasive or invasive mechanical ventilation when needed, were important for the management of the disease.

Surface molecularly imprinted nanowires for biorecognition.

Herein we present a novel method for preparation of surface molecularly imprinted size-monodisperse nanowires. The imprint molecule is immobilized on the pore walls of a silane-treated nanoporous alumina membrane. The nanopores are then filled with the monomer mixture, and the polymerization is initiated. The alumina membrane is subsequently removed by chemical dissolution, leaving behind polypyrrole nanowires with glutamic acid binding sites situated at the surface. These nanowires can be dissolved in aqueous media, and their applications therefore should be compatible with procedures in which biological antibodies might otherwise be used. For example, the analyte molecule can be tagged with various markers, such as fluorescence probes and enzymes, whereby the problem of steric hindrance is avoided. Furthermore, these surface-imprinted nanowires are likely suited for imprinting and recognition of large-molecular-weight peptides and proteins. Related work is currently being undertaken in our laboratory.

[Determination of mercury in Chinese medicinal material and biological samples using pyrolysis atomic absorption spectrometry].

In this paper a rapid and simple method using pyrolysis coupled with atomic absorption spectrometry for the analysis of total mercury in Chinese medicinal material and biological samples is presented. No sample digestion was needed and this greatly simplifies the analytical procedure and minimizes potential sources of contamination. Under optimum conditions, the reproducibility of the method was 2.1% for peak area and 9.1% for peak height. The detection limit (3sigma) was 6.3 ng x g(-1), and the recovery was within the range of 95%-105%. Several standard reference materials were analyzed and the results were obtained with satisfaction. The performance of the method was compared with inductively coupled plasma-mass spectrometry (ICP-MS), and excellent agreements were observed between these two methods.

Molecularly imprinted sol-gel nanotubes membrane for biochemical separations.

In this study, we report a simple procedure for applying molecular imprinting functional groups to the inner surfaces of the template-synthesized sol-gel nanotubes for chemical separation of estrone. The silica nanotubes were synthesized within the pores of nanopore alumina template membranes using a sol-gel method by simultaneous hydrolysis of a silica monomer-imprinted molecule complex and tetraethoxysilane (TEOS). A covalent imprinting strategy was employed by generating a sacrificial spacer through the reaction of the isocyanate group of 3-(triethoxysilyl)propyl isocyanate and a phenol moiety of estrone to form a thermally cleavable urethane bond. This allowed us to remove the imprinted estrone by simple thermal reaction and to simultaneously introduce functional groups into the cavity formed by the silica nanotubes. Experiments indicated that estrone could be bound selectively by such an approach and have a binding affinity of 864 +/- 137 (n = 3).

Magnetite-containing spherical silica nanoparticles for biocatalysis and bioseparations.

The simultaneous entrapment of biological macromolecules and nanostructured silica-coated magnetite in sol-gel materials using a reverse-micelle technique leads to a bioactive, mechanically stable, nanometer-sized, and magnetically separable particles. These spherical particles have a typical diameter of 53 +/- 4 nm, a large surface area of 330 m(2)/g, an average pore diameter of 1.5 nm, a total pore volume of 1.427 cm(3)/g and a saturated magnetization (M(S)) of 3.2 emu/g. Peroxidase entrapped in these particles shows Michaelis-Mentan kinetics and high activity. The catalytic reaction will take place immediately after adding these particles to the reaction solution. These enzyme entrapping particles catalysts can be easily separated from the reaction mixture by simply using an external magnetic field. Experiments have proved that these catalysts have a long-term stability toward temperature and pH change, as compared to free enzyme molecules. To further prove the application of this novel magnetic biomaterial in analytical chemistry, a magnetic-separation immunoassay system was also developed for the quantitative determination of gentamicin. The calibration for gentamicin has a working range of 200-4000 ng/mL, with a detection limit of 160 ng/mL, which is close to that of the fluorescent polarization immunoassay (FPIA) using the same reactants.