Establishment and Evaluation of a Novel Method Based on Loop-Mediated Isothermal Amplification for the Rapid Diagnosis of Thalassemia Genes.

PURPOSE: Currently, thalassemia is commonly detected using gap-polymerase chain reaction (PCR) and deoxyribonucleic acid (DNA) reverse dot blot, which have high requirements of space, instruments, and personnel. Therefore, it is necessary to develop a new method for thalassemia detection with high sensitivity, low cost, and simple and fast operation. In this study, we aimed to design and evaluate a new method for detecting three α-thalassemia genes including -Southeast Asian (SEA), -α3.7, and -α4.2 and five ß-thalassemia genes including 654M, 41/42M, -28M, 17M, and 27/28M based on loop-mediated isothermal amplification (LAMP). METHODS: Primer sequences were designed using Primer Explorer V4 software. Blood samples (5 mL) were collected from all participants in EDTA. DNA was extracted using Chelex 100 and was subjected to LAMP. LAMP products were detected by fluorescence development in ultraviolet light. RESULTS: We found that LAMP assays for positive samples of thalassemia reached a plateau before 60 minutes, whereas the negative control samples entered the plateau after 70 minutes or showed no amplification. The concentration range of positive reactions was between 20-60 pg/µL and 20-60 ng/µL. Additionally, there were no cross-reactivities among 8 thalassemia subtypes. For clinical samples, the positive sample tube showed strong green fluorescence, whereas the negative tube showed light green fluorescence. According to these results, the LAMP method has high sensitivity for detecting thalassemia (252/254). However, 43 false-positive results were obtained in the LAMP test. The LAMP assay was also of low cost and with simple and fast operation. CONCLUSION: The novel LAMP assay can be completed within 60 min using a heating block or a water bath, and the result can be read visually based on color change to detect thalassemia. The LAMP assay fulfills the requirements of field application and resource-limited areas, especially those with primary hospitals and rural areas.

Association of Overlapped and Un-overlapped Comorbidities with COVID-19 Severity and Treatment Outcomes: A Retrospective Cohort Study from Nine Provinces in China.

OBJECTIVE: Several COVID-19 patients have overlapping comorbidities. The independent role of each component contributing to the risk of COVID-19 is unknown, and how some non-cardiometabolic comorbidities affect the risk of COVID-19 remains unclear. METHODS: A retrospective follow-up design was adopted. A total of 1,160 laboratory-confirmed patients were enrolled from nine provinces in China. Data on comorbidities were obtained from the patients' medical records. Multivariable logistic regression models were used to estimate the odds ratio ( OR) and 95% confidence interval (95% CI) of the associations between comorbidities (cardiometabolic or non-cardiometabolic diseases), clinical severity, and treatment outcomes of COVID-19. RESULTS: Overall, 158 (13.6%) patients were diagnosed with severe illness and 32 (2.7%) had unfavorable outcomes. Hypertension (2.87, 1.30-6.32), type 2 diabetes (T2DM) (3.57, 2.32-5.49), cardiovascular disease (CVD) (3.78, 1.81-7.89), fatty liver disease (7.53, 1.96-28.96), hyperlipidemia (2.15, 1.26-3.67), other lung diseases (6.00, 3.01-11.96), and electrolyte imbalance (10.40, 3.00-26.10) were independently linked to increased odds of being severely ill. T2DM (6.07, 2.89-12.75), CVD (8.47, 6.03-11.89), and electrolyte imbalance (19.44, 11.47-32.96) were also strong predictors of unfavorable outcomes. Women with comorbidities were more likely to have severe disease on admission (5.46, 3.25-9.19), while men with comorbidities were more likely to have unfavorable treatment outcomes (6.58, 1.46-29.64) within two weeks. CONCLUSION: Besides hypertension, diabetes, and CVD, fatty liver disease, hyperlipidemia, other lung diseases, and electrolyte imbalance were independent risk factors for COVID-19 severity and poor treatment outcome. Women with comorbidities were more likely to have severe disease, while men with comorbidities were more likely to have unfavorable treatment outcomes.

Design and Evaluation of a Novel Multiplex Real-Time PCR Melting Curve Assay for the Simultaneous Detection of Nine Sexually Transmitted Disease Pathogens in Genitourinary Secretions.

Background: Sexually transmitted diseases (STD) are a major cause of infertility, long-term disability, ectopic pregnancy, and premature birth. Therefore, the development of fast and low-cost laboratory STD diagnostic screening methods will contribute to reducing STD-induced reproductive tract damage and improve women's health worldwide. In this study, we evaluated a novel multiplex real-time PCR melting curve assay method for the simultaneous detection of 9 STD pathogens, including Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, Ureaplasma parvum, and herpes simplex virus. Methods: The analytical performance of the method, including its limit of detection (LOD), specificity, repeatability, and effect on different DNA extraction kits were evaluated. Additionally, we obtained 1,328 clinical specimens from 3 hospitals to detect the 9 STD pathogens using multiplex real-time PCR melting curve and Sanger sequencing, to evaluate the sensitivity, specificity, and consistency of the assay method. Results: The results showed that the analytical sensitivity of the novel multiplex real-time PCR melting curve assay is very excellent, with LOD of DNA corresponding to <200 copies/µL for the DNA of the 9 STDs and 1.00 × 104 color change unit /ml for those of UU and UP. Additionally, this assay demonstrated excellent analytical specificity, excellent repeatability, and its results had no effect of different DNA extraction kits. The performance, in terms of sensitivity (91.06-100%) and specificity (99.14-100%), was remarkable, since the consistency between it and Sanger sequencing was more than 0.85 in the clinic. Conclusion: The novel multiplex real-time PCR melting curve assay method has high sensitivity and specificity, relatively low cost, and simple to use for the simultaneous detection of 9 STD pathogens in genitourinary secretions.

[Differential expressions of the receptor for advanced glycation end products in prostate cancer and normal prostate].

OBJECTIVE: To study the differential expressions of the receptor for advanced glycation end products (RAGE) in the tissues of prostate cancer and normal prostate, and to find the role of RAGE in the pathogenesis of prostate cancer. METHODS: We collected the tissue of prostate cancer and that of normal prostate from the same patient, and compared the differential expressions of RAGE at the tissue, protein and mRNA levels between prostate cancer and normal prostate tissues of 10 patients by immunohistochemistry, Western blot and real-time quantitative PCR. RESULTS: Immunohistochemistry exhibited a significantly higher expression of RAGE in the prostate cancer tissue than in the normal prostate tissue; Western blot showed that the RAGE protein expression was 2.13 times higher in the former than in the latter (P < 0.05); and real-time quantitative PCR revealed the RAGE mRNA expression of the former to be 4.2 times that of the latter (P < 0.05). CONCLUSION: RAGE may play an important role in the pathogenesis and progression of prostate cancer.

[Construction, expression and location of eukaryotic expression vector CMV-FLAG-RB in human prostate cancer PC-3 cells].

OBJECTIVE: To construct an eukaryotic recombinant expression vector for retinoblastoma 1 gene (RB-1) and investigate the role of RB-1 in prostate cancer. METHODS: The coding sequence of RB-1 gene tagged with FLAG was amplified from the plasmid CMV-RB by PCR method. The fragment was cloned into CMV expression vector and identified by restriction enzyme digestion and sequence analysis. Western Blotting was used to detect RB-1 expression and immunofluorescence was used to observe RB-1 distribution in PC-3 cells transfected with the recombinant. RESULTS: The expression vector CMV-FLAG-RB was successfully constructed as confirmed by PCR, endonuclease digestion and DNA sequence analysis. RB-1 protein was highly expressed and showed a nuclear distribution in PC-3 cells transfected with the recombinant. CONCLUSIONS: The eukaryotic expression vector for RB-1 has been successfully constructed and can be efficiently expressed in PC-3 cells. The expression of RB-1 is located in the cell nuclei.