False positives in reverse transcription PCR testing for SARS-CoV-2

Unlike previous epidemics, in addressing COVID-19 nearly all international health organizations and national health ministries have treated a single positive result from a PCR-based test as confirmation of infection, even in asymptomatic persons without any history of exposure. This is based on a widespread belief that positive results in these tests are highly reliable. However, data on PCR-based tests for similar viruses show that PCR-based testing produces enough false positive results to make positive results highly unreliable over a broad range of real-world scenarios. This has clinical and case management implications, and affects an array of epidemiological statistics, including the asymptomatic ratio, prevalence, and hospitalization and death rates. Steps should be taken to raise awareness of false positives, reduce their frequency, and mitigate their effects. In the interim, positive results in asymptomatic individuals that havent been confirmed by a second test should be considered suspect. Key messagesThe high specificities (usually 100%) reported in PCR-based tests for SARS-CoV-2 infection do not represent the real-world use of these tests, where contamination and human error produce significant rates of false positives. Widespread misunderstanding of these false positive rates affects an array of clinical, case management and health policy decisions. Similarly, health authorities guidance on interpreting test results is often wrong. Steps should be taken immediately to reduce the frequency and impacts of false positive results.

Effects of 17β-Estradiol on the Plasminogen Activator System in Vascular Smooth Muscle Cells Treated with Lysophophatidylcholine

Objectives@#When administered soon after menopause, hormone therapy can prevent coronary heart diseases in women. To explore the mechanism underlying the cardioprotective actions of estrogen, we investigated the effects of 17β-estradiol (17β-E2) on the plasminogen activator system using cultured vascular smooth muscle cells (VSMCs). @*Methods@#VSMCs were isolated from rat aortas. Protein expression of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated using Western blotting and enzyme-linked immunosorbent assay, respectively. The enzyme activity of PAI-1 in a conditioned medium was assessed via reverse fibrin overlay zymography and that of t-PA was assessed via fibrin overlay zymography. Gene expression was quantified using real-time reverse transcription-polymerase chain reaction. @*Results@#Following pre-treatment for 24 hours, 17β-E2 suppressed both protein expression and enzyme activity of PAI-1 stimulated by lysophosphatidylcholine (lysoPC) in a significant and dose-dependent manner at a near physiological concentration. Moreover, 17β-E2 (10−7 M) inhibited PAI-1 gene expression, and ICI 182,780—a specific estrogen receptor antagonist—blocked the effects of 17β-E2 on the PAI-1 protein. 17β-E2 did not affect t-PA secretion but significantly enhanced free t-PA activity through reduced binding to PAI-1. Furthermore, 17β-E2 suppressed intracellular reactive oxygen species production and nuclear factor-κB-mediated transcription. @*Conclusions@#In VSMCs stimulated with lysoPC, 17β-E2 reduced PAI-1 expression through a non-receptor-mediated mechanism via antioxidant activity as well as a receptor-mediated mechanism; however, it did not alter t-PA secretion. Of note, 17β-E2 suppressed PAI- 1 activity and concurrently enhanced t-PA activity, suggesting a beneficial influence on fibrinolysis.

Differences in risk for type 1 and type 2 ovarian cancer in a large cancer screening trial / 부인종양

OBJECTIVE: To investigate the role of previous gynecologic surgery, hormone use, and use of non-steroidal anti-inflammatory drugs on the risk of type 1 and type 2 ovarian cancer. METHODS: We utilized data collected for the Prostate, Lung, Colorectal, and Ovarian cancer screening trial. All diagnosed ovarian cancers were divided into three groups: type 1, endometrioid, clear cell, mucinous, low grade serous, and low grade adenocarcinoma/not otherwise specified (NOS); type 2, high grade serous, undifferentiated, carcinosarcoma, and high grade adenocarcinoma/NOS; and other: adenocarcinoma with grade or histology not specified, borderline tumors, granulosa cell tumors. The odds ratios for type 1, type 2, and other ovarian cancers were assessed with regard to historical information for specific risk factors. RESULTS: Ibuprofen use was associated with a decrease in risk for type 1 ovarian cancer. Tubal ligation and oral contraceptive use were associated with a decrease in risk for type 2 ovarian cancer. A history of ectopic pregnancy was associated with a decreased risk for all ovarian cancers by almost 70%. CONCLUSION: These findings support the hypothesis that carcinogenic pathways for type 1 and type 2 ovarian cancer are different and distinct. The marked reduction in all ovarian cancer risk noted with a history of ectopic pregnancy and salpingectomy implies that the fallopian tube plays a key role in carcinogenesis for both type 1 and type 2 ovarian cancer.

Ovarian cancer screening in menopausal females with a family history of breast or ovarian cancer / 부인종양

OBJECTIVE: To determine whether annual screening reduces ovarian cancer mortality in women with a family history of breast or ovarian cancer. METHODS: Data was obtained from the Prostate, Lung, Colorectal, and Ovarian cancer trial, a randomized multi-center trial conducted to determine if screening could reduce mortality in these cancers. The trial enrolled 78,216 women, randomized into either a screening arm with annual serum cancer antigen 125 and pelvic ultrasounds, or usual care arm. This study identified a subgroup that reported a first degree relative with breast or ovarian cancer. Analysis was performed to compare overall mortality and disease specific mortality in the screening versus usual care arm. In patients diagnosed with ovarian cancer, stage distribution, and survival were analyzed as a secondary endpoint. RESULTS: There was no significant difference in overall mortality or disease specific mortality between the two arms. Ovarian cancer was diagnosed in 48 patients in the screening arm and 44 patients in the usual care arm. Screened patients were more likely to be diagnosed at an earlier stage than usual care patients. Patients in the screening arm diagnosed with ovarian cancer experienced a significantly improved survival compared to patients in the usual care arm; relative risk 0.66 (95% CI, 0.47 to 0.93). CONCLUSION: Screening did not appear to decrease ovarian cancer mortality in participants with a family history of breast or ovarian cancer. Secondary endpoints, however, showed notable differences. Significantly fewer patients were diagnosed with advanced stage disease in the screening arm; and survival was significantly improved. Further investigation is warranted to assess screening efficacy in women at increased risk.

Ovarian cancer screening in menopausal females with a family history of breast or ovarian cancer / 부인종양

OBJECTIVE: To determine whether annual screening reduces ovarian cancer mortality in women with a family history of breast or ovarian cancer. METHODS: Data was obtained from the Prostate, Lung, Colorectal, and Ovarian cancer trial, a randomized multi-center trial conducted to determine if screening could reduce mortality in these cancers. The trial enrolled 78,216 women, randomized into either a screening arm with annual serum cancer antigen 125 and pelvic ultrasounds, or usual care arm. This study identified a subgroup that reported a first degree relative with breast or ovarian cancer. Analysis was performed to compare overall mortality and disease specific mortality in the screening versus usual care arm. In patients diagnosed with ovarian cancer, stage distribution, and survival were analyzed as a secondary endpoint. RESULTS: There was no significant difference in overall mortality or disease specific mortality between the two arms. Ovarian cancer was diagnosed in 48 patients in the screening arm and 44 patients in the usual care arm. Screened patients were more likely to be diagnosed at an earlier stage than usual care patients. Patients in the screening arm diagnosed with ovarian cancer experienced a significantly improved survival compared to patients in the usual care arm; relative risk 0.66 (95% CI, 0.47 to 0.93). CONCLUSION: Screening did not appear to decrease ovarian cancer mortality in participants with a family history of breast or ovarian cancer. Secondary endpoints, however, showed notable differences. Significantly fewer patients were diagnosed with advanced stage disease in the screening arm; and survival was significantly improved. Further investigation is warranted to assess screening efficacy in women at increased risk.