Small interfering RNA (siRNA)-based therapeutic applications against viruses: principles, potential, and challenges.

RNA has emerged as a revolutionary and important tool in the battle against emerging infectious diseases, with roles extending beyond its applications in vaccines, in which it is used in the response to the COVID-19 pandemic. Since their development in the 1990s, RNA interference (RNAi) therapeutics have demonstrated potential in reducing the expression of disease-associated genes. Nucleic acid-based therapeutics, including RNAi therapies, that degrade viral genomes and rapidly adapt to viral mutations, have emerged as alternative treatments. RNAi is a robust technique frequently employed to selectively suppress gene expression in a sequence-specific manner. The swift adaptability of nucleic acid-based therapeutics such as RNAi therapies endows them with a significant advantage over other antiviral medications. For example, small interfering RNAs (siRNAs) are produced on the basis of sequence complementarity to target and degrade viral RNA, a novel approach to combat viral infections. The precision of siRNAs in targeting and degrading viral RNA has led to the development of siRNA-based treatments for diverse diseases. However, despite the promising therapeutic benefits of siRNAs, several problems, including impaired long-term protein expression, siRNA instability, off-target effects, immunological responses, and drug resistance, have been considerable obstacles to the use of siRNA-based antiviral therapies. This review provides an encompassing summary of the siRNA-based therapeutic approaches against viruses while also addressing the obstacles that need to be overcome for their effective application. Furthermore, we present potential solutions to mitigate major challenges.

Association of 3-hydroxy-3-methylglutaryl-coenzyme A reductase gene polymorphism with obesity and lipid metabolism in children and adolescents with autism spectrum disorder.

The prevalence of obesity among children and adolescents with autism spectrum disorder (ASD) is higher than that among typically developing children and adolescents. However, very few studies have explored the genetic factors associated with obesity in children and adolescents with ASD. Thus, the aim of this study was to examine the associations between 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) gene polymorphisms and obesity among children and adolescents with ASD. The study participants consisted of 33 children and adolescents with ASD and 271 age- and sex-matched typically developing controls. We compared the metabolic traits (body mass index, blood pressure, triglyceride, high-density lipoprotein, and fasting glucose levels) between the ASD and control group. Furthermore, we assessed the genotypes of rs12654264 in the HMGCR gene within the participants with ASD, and compared metabolic traits among the different allele subgroups. The mean body mass index (BMI) and triglyceride level of the ASD group were significantly higher than those of the control group. Within the ASD group, the triglyceride level of participants with rs12654264-T alleles was significantly higher than that of participants with A-alleles. A pattern of increasing values in the BMI and fasting glucose was also observed in participants with T allele. This is the first study to show that obesity in children and adolescents with ASD is associated with the cholesterol synthesis pathway. Future studies are needed to further clarify the molecular mechanisms by which the HMGCR gene influences metabolic traits.

Highly Bright Silica-Coated InP/ZnS Quantum Dot-Embedded Silica Nanoparticles as Biocompatible Nanoprobes.

Quantum dots (QDs) have outstanding optical properties such as strong fluorescence, excellent photostability, broad absorption spectra, and narrow emission bands, which make them useful for bioimaging. However, cadmium (Cd)-based QDs, which have been widely studied, have potential toxicity problems. Cd-free QDs have also been studied, but their weak photoluminescence (PL) intensity makes their practical use in bioimaging challenging. In this study, Cd-free QD nanoprobes for bioimaging were fabricated by densely embedding multiple indium phosphide/zinc sulfide (InP/ZnS) QDs onto silica templates and coating them with a silica shell. The fabricated silica-coated InP/ZnS QD-embedded silica nanoparticles (SiO2@InP QDs@SiO2 NPs) exhibited hydrophilic properties because of the surface silica shell. The quantum yield (QY), maximum emission peak wavelength, and full-width half-maximum (FWHM) of the final fabricated SiO2@InP QDs@SiO2 NPs were 6.61%, 527.01 nm, and 44.62 nm, respectively. Moreover, the brightness of the particles could be easily controlled by adjusting the amount of InP/ZnS QDs in the SiO2@InP QDs@SiO2 NPs. When SiO2@InP QDs@SiO2 NPs were administered to tumor syngeneic mice, the fluorescence signal was prominently detected in the tumor because of the preferential distribution of the SiO2@InP QDs@SiO2 NPs, demonstrating their applicability in bioimaging with NPs. Thus, SiO2@InP QDs@SiO2 NPs have the potential to successfully replace Cd-based QDs as highly bright and biocompatible fluorescent nanoprobes.

Au-Ag assembled on silica nanoprobes for visual semiquantitative detection of prostate-specific antigen.

BACKGROUND: Blood prostate-specific antigen (PSA) levels are widely used as diagnostic biomarkers for prostate cancer. Lateral-flow immunoassay (LFIA)-based PSA detection can overcome the limitations associated with other methods. LFIAbased PSA detection in clinical samples enables prognosis and early diagnosis owing to the use of high-performance signal reporters. RESULTS: Here, a semiquantitative LFIA platform for PSA detection in blood was developed using Au-Ag nanoparticles (NPs) assembled on silica NPs (SiO2@Au-Ag NPs) that served as signal reporters. Synthesized SiO2@Au-Ag NPs exhibited a high absorbance at a wide wavelength range (400-800 nm), with a high scattering on nitrocellulose membrane test strips. In LFIA, the color intensity of the test line on the test strip differed depending on the PSA concentration (0.30-10.00 ng/mL), and bands for the test line on the test strip could be used as a standard. When clinical samples were assessed using this LFIA, a visual test line with particular color intensity observed on the test strip enabled the early diagnosis and prognosis of patients with prostate cancer based on PSA detection. In addition, the relative standard deviation of reproducibility was 1.41%, indicating high reproducibility, and the signal reporter showed good stability for 10 days. CONCLUSION: These characteristics of the signal reporter demonstrated the reliability of the LFIA platform for PSA detection, suggesting potential applications in clinical sample analysis.

Inhibition of SARS-CoV-2 Virus Entry by the Crude Polysaccharides of Seaweeds and Abalone Viscera In Vitro.

Much attention is being devoted to the potential of marine sulfated polysaccharides as antiviral agents in preventing COVID-19. In this study, sulfated fucoidan and crude polysaccharides, extracted from six seaweed species (Undaria pinnatifida sporophyll, Laminaria japonica, Hizikia fusiforme, Sargassum horneri, Codium fragile, Porphyra tenera) and Haliotis discus hannai (abalone viscera), were screened for their inhibitory activity against SARS-CoV-2 virus entry. Most of them showed significant antiviral activities at an IC50 of 12~289 µg/mL against SARS-CoV-2 pseudovirus in HEK293/ACE2, except for P. tenera (IC50 > 1000 µg/mL). The crude polysaccharide of S. horneri showed the strongest antiviral activity, with an IC50 of 12 µg/mL, to prevent COVID-19 entry, and abalone viscera and H. fusiforme could also inhibit SARS-CoV-2 infection with an IC50 of 33 µg/mL and 47 µg/mL, respectively. The common properties of these crude polysaccharides, which have strong antiviral activity, are high molecular weight (>800 kDa), high total carbohydrate (62.7~99.1%), high fucose content (37.3~66.2%), and highly branched polysaccharides. These results indicated that the crude polysaccharides from seaweeds and abalone viscera can effectively inhibit SARS-CoV-2 entry.

Silver-Assembled Silica Nanoparticles in Lateral Flow Immunoassay for Visual Inspection of Prostate-Specific Antigen.

Prostate-specific antigen (PSA) is the best-known biomarker for early diagnosis of prostate cancer. For prostate cancer in particular, the threshold level of PSA <4.0 ng/mL in clinical samples is an important indicator. Quick and easy visual detection of the PSA level greatly helps in early detection and treatment of prostate cancer and reducing mortality. In this study, we developed optimized silica-coated silver-assembled silica nanoparticles (SiO2@Ag@SiO2 NPs) that were applied to a visual lateral flow immunoassay (LFIA) platform for PSA detection. During synthesis, the ratio of silica NPs to silver nitrate changed, and as the synthesized NPs exhibited distinct UV spectra and colors, most optimized SiO2@Ag@SiO2 NPs showed the potential for early prostate cancer diagnosis. The PSA detection limit of our LFIA platform was 1.1 ng/mL. By applying each SiO2@Ag@SiO2 NP to the visual LFIA platform, optimized SiO2@Ag@SiO2 NPs were selected in the test strip, and clinical samples from prostate cancer patients were successfully detected as the boundaries of non-specific binding were clearly seen and the level of PSA was <4 ng/mL, thus providing an avenue for quick prostate cancer diagnosis and early treatment.

Wikstroemiaganpi Extract Improved Atopic Dermatitis-Like Skin Lesions via Suppression of Interleukin-4 in 2,4-Dinitrochlorobenzene-Induced SKH-1 Hairless Mice.

Plants of the genus Wikstroemia are used in Chinese traditional medicine to treat inflammatory diseases, such as arthritis, bronchitis, and pneumonia. The present study was designed to determine whether Wikstroemia ganpi (Siebold and Zucc.) Maxim. offers a potential means of treating 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis (AD) in mice. Symptoms such as redness, edema, and keratinization in AD mice induced by DNCB were alleviated by the co-application of an ethanolic extract of W. ganpi for 2 weeks. The severity of skin barrier function damage was evaluated by measuring TEWL (transepidermal water loss). TEWLs of DNCB sensitized mouse dorsal skin were reduced by the application of a W. ganpi ethanolic extract, and skin hydration was increased. In addition, the infiltration of inflammatory cells into the dermis was significantly reduced, as were blood levels of IgE and IL-4, which play an important role in the expression of AD. The results of this experiment suggest that W. ganpi is a potential therapeutic agent for AD.

MicroRNA-98 is a prognostic factor for asbestos-induced mesothelioma.

Malignant pleural mesothelioma (MPM) is a type of cancer characterized by a short survival time and poor prognosis. Malignant pleural mesothelioma is most frequently associated with exposure to asbestos and other elongated mineral fibers. The aim of this study was to examine molecular differences between asbestos-exposed and non-exposed MPM patients and assess prognostic significances of molecular factors. Clinical and genetic data were downloaded from Cancer Genome Atlas. To identify the molecular differences, Significant Analysis of Microarray method was used. Prognostic significances of differentially expressed genes were confirmed by using Kaplan-Meier curve with the Log-Rank test. Although mRNAs did not exhibit any significant differences between the two patient groups, nine miRNAs were found to be down-regulated in the asbestos-exposed group. The top five pathways most relevant to the selected miRNAs were extracted through pathway enrichment analysis. Survival analysis revealed that high expression of only hsa-miR-98 was significantly associated with poor prognosis in patients with asbestos-exposed MPM. Evidence suggests that management of the aggressiveness and progression of asbestos-induced MPM may require high levels of hsa-miR-98 due to its tumor-suppressive role. This study might be helpful in enhancing our understanding of the biological mechanisms underlying asbestos-induced MPM and for acquiring greater insights into targeted therapy.Abbreviations: FDR: false discovery rate; MM: malignant mesothelioma; MPM: malignant pleural mesothelioma; mRNA: messenger RNA; miRNA: microRNA; SAM: significance analysis of microarrays; TCGA: the cancer genome atlas.

Prospective Physician Awareness of the Associations Between Social Media and Mental Health.

OBJECTIVE: Recently, studies have cited negative, positive, and an absence of impact on mental health with social media use. However, there has been little studied regarding the level of awareness and training of clinicians in screening and identifying for these associations. For this reason, the authors designed a study to assess the awareness of prospective physicians, or current medical students, on the associations between mental health and social media. METHODS: The study was in the form of a 12-question survey. The questions aimed at assessing the awareness through past experiences with social media, education of its use and potential impacts, and self-reported ability to screen, identify, and counsel patients on these associations. The survey was sent to a total of 634 medical students and included all classes from MS1-MS4. A total of 148 students completed this survey (23.3% response rate). RESULTS: The majority of medical students reported first social media use between the ages of 13 and 18, with the most common occurrence of bullying identified in this age group as well. The majority percentage of students believed there could be both positive and negative effects of social media on mental health; however, only a small percentage of students reported being aware of specific patterns of social media use that are associated with mental health. Moreover, only a few students reported feeling adequate in their ability to screen, educate, and counsel patients on these associations. CONCLUSIONS: Findings from this study suggest the need for educational resources to train future physicians in screening, identifying, and counseling patients on associations between social media and mental health. The small numbers in this study are a limiting factor for the validity of result interpretation.

Comparison of Services for Autism Spectrum Disorder in Massachusetts with Those in Seoul.

BACKGROUND: This article intended to identify and describe areas in need of services and interventions for individuals with autism spectrum disorder (ASD) and their families in Seoul, Korea. METHODS: A descriptive comparison was made between available services and interventions in Seoul, Korea and Massachusetts, USA. Relevant information was obtained through sending phone/email inquiries to the governments and organizations, visiting their official websites, and searching for published articles or reports. RESULTS: In a few areas such as level of education, economy, and general quality of healthcare, Seoul was found to be similar to Massachusetts. However, in terms of services and interventions for individuals with ASD and their families, especially early identification and intervention, special education, care coordination, school-based programs, and transition to adulthood, Massachusetts was shown to have far more availability. CONCLUSION: The limited availability of services and interventions for individuals with ASD and their families in Seoul in comparison to Massachusetts, underlines target areas for further investment and development.

Development of a scoring system to predict massive postpartum transfusion in placenta previa totalis.

PURPOSE: It is important to predict massive postpartum hemorrhage in patients with placenta previa totalis (PPT) and a method that accurately predicts this event is needed. The present study developed a scoring system that predicts massive transfusion in patients with PPT. METHODS: This single-center retrospective cohort study comprised 238 patients with PPT who underwent caesarean section between January 2004 and December 2010. Massive transfusion was defined as the transfusion of ≥8 units of packed red blood cells within 24 h after delivery. Multivariate regression analysis was used to estimate the risks of massive transfusion. A probability score model was then constructed and tested for performance. Subsequently, the model was validated in other patients with PPT (n = 117). RESULTS: Thirty-one patients (13.0%) underwent massive transfusion. Ultrasound suspicion of placental adhesion, previous caesarean section, gestational age <37 weeks, sponge-like appearance of the cervix, and anterior placenta were all independent predictors of massive transfusion. The performance for the score model revealed good calibration (Hosmer-Lemeshow chi-squared 1.64; P = 0.44), and its discrimination (the area under the receiver operating characteristic for this model was 0.84) was better than when suspicion of placental adhesion was used alone (0.67; P < 0.001). In the validation set, the performance was 0.88. CONCLUSION: The scoring system developed using the five independent risk factors had better performance to predict massive transfusion in patients with PPT than when suspicion of placental adhesion was used alone. However, further large-scale studies are warranted to clarify the usefulness and accuracy of this model.

Identification of the NAC1-regulated genes in ovarian cancer.

Nucleus accumbens-associated protein 1 (NAC1), encoded by the NACC1 gene, is a transcription co-regulator that plays a multifaceted role in promoting tumorigenesis. However, the NAC1-regulated transcriptome has not been comprehensively defined. In this study, we compared the global gene expression profiles of NAC1-overexpressing SKOV3 ovarian cancer cells and NAC1-knockdown SKOV3 cells. We found that NAC1 knockdown was associated with up-regulation of apoptotic genes and down-regulation of genes involved in cell movement, proliferation, Notch signaling, and epithelial-mesenchymal transition. Among NAC1-regulated genes, FOXQ1 was further characterized because it is involved in cell motility and epithelial-mesenchymal transition. NAC1 knockdown decreased FOXQ1 expression and promoter activity. Similarly, inactivation of NAC1 by expression of a dominant-negative construct of NAC1 suppressed FOXQ1 expression. Ectopic expression of NAC1 in NACC1 null cells induced FOXQ1 expression. NAC1 knockdown resulted in decreased cell motility and invasion, whereas constitutive expression of FOXQ1 rescued motility in cells after NAC1 silencing. Moreover, in silico analysis revealed a significant co-up-regulation of NAC1 and FOXQ1 in ovarian carcinoma tissues. On the basis of transcription profiling, we report a group of NAC1-regulated genes that may participate in multiple cancer-related pathways. We further demonstrate that NAC1 is essential and sufficient for activation of FOXQ1 transcription and that the role of NAC1 in cell motility is mediated, at least in part, by FOXQ1.

Preoperative factors as a predictor for early postoperative outcomes after repair of congenital transposition of the great arteries.

Transposition of the great arteries (TGA) requires early surgical repair during the neonatal period. Several preoperative factors have been identified for the postoperative poor outcome after arterial switch operation (ASO). However, the data remain uncertain an association. Therefore, we investigated the preoperative factors which affect the early postoperative outcomes. Between March 2005 and May 2012, a retrospective study was performed which included 126 infants with an ASO for TGA. Preoperative data included the vasoactive inotropic score (VIS) and baseline hemodynamics. Early postoperative outcomes included the duration of mechanical ventilation, the length of stay in the intensive care unit and hospital, and early mortality. Multivariate linear regression and receiver operating characteristics analysis were performed. The duration of mechanical ventilation was significantly correlated with the preoperative mechanical ventilator support and VIS, and CPB time. On multivariate linear regression analysis, a higher preoperative VIS, preoperative B-type natriuretic peptide (BNP) level, and the CPB time were identified as independent risk factors for delayed mechanical ventilation. Preoperative VIS (OR 1.154, 95 % CI 1.024-1.300) and the CPB time (OR 1.034, 95 % CI 1.009-1.060) were independent parameters predicting early mortality. A preoperative VIS of 12.5 had the best combined sensitivity (83.3 %) and specificity (85.3 %) and an AUC of 0.852 (95 % CI 0.642-1.061) predicted early mortality. Our results suggest that preoperative VIS and BNP can predict the need for prolonged postoperative mechanical ventilation. Moreover, preoperative VIS may be used as a simple and feasible indicator for predicting early mortality.

Prevalence of uninvestigated dyspepsia and gastroesophageal reflux disease in Korea: a population-based study using the Rome III criteria.

BACKGROUND/AIMS: There have been few population-based studies on the prevalences of gastroesophageal reflux disease (GERD) and dyspepsia using Rome III criteria in Asian countries. METHODS: A population-based, cross-sectional study was conducted by telephone interviews of 5,000 Koreans between the ages of 20-69 years. Gastrointestinal symptoms were assessed by a translated Korean version of Rome III criteria. Uninvestigated dyspepsia (UID) was defined by symptom criteria of Rome III. GERD was defined by troublesome heartburn and/or acid regurgitation occurring at least once a week. The EQ5D assessment tool was used for the evaluation of quality of life. RESULTS: The prevalences of UID, postprandial distress syndrome (PDS), and epigastric pain syndrome (EPS) were 7.7, 5.6, and 4.2 %, respectively. Overlap between PDS and EPS was found in 27.1 % (104/384) of subjects with UID. There were no significant differences in demographic variables between patients with PDS and EPS. The prevalence of GERD was 7.1 %. Overlap between GERD and UID was found in 50.0 % of GERD patients. The EQ5D index of patients without either UID or GERD was 0.92 ± 0.07, and those of patients with only UID, with only GERD, and with both UID and GERD were 0.88 ± 0.09, 0.88 ± 0.11, and 0.84 ± 0.15, respectively. CONCLUSIONS: GERD and UID based on Rome III criteria were prevalent and significantly affected the quality of life in Korea. In Korean patients with UID, there was considerable overlap and there were no significant differences in demographic variables between PDS and EPS.

Compensation for work-related hematologic, liver, and infectious diseases.

Occupational diseases may be defined only medically or scientifically, and even then, their definition is not simple. However, compensable occupational diseases involve the additional layer of legal systems and social welfare policies as well. Their multifaceted nature makes determining the work-relatedness of these diseases more complex. Korea has established standards for the recognition of occupational diseases in Schedule 5 of the Enforcement Decree of the Labor Standards Act, and specific criteria for the recognition of occupational diseases are listed in Schedule 3 of the Enforcement Decree of the Industrial Accident Compensation Insurance Act. The new list of compensable occupational diseases comprises 13 articles as an open-ended system. The newly added articles pertain to lymphohematopoietic (Article 5) and infectious diseases (Article 9), as well as diseases of other target organs. Furthermore, the article on liver diseases (Article 8) has been partially revised. The new act has been changed to clarify the meaning as it has been presented in recent research. It is necessary to achieve agreement among concerned parties, including experts from the legal, medical, and social domains to resolve the issues of work-relatedness, causation, notion of aggravation, and so on for preparing a list and a process that are more reasonable.

Splanchnic oxygen saturation immediately after weaning from cardiopulmonary bypass can predict early postoperative outcomes in children undergoing congenital heart surgery.

This study compared the abilities of cerebral, renal, and splanchnic regional oxygen saturation (rSO2) immediately after weaning from cardiopulmonary bypass (CPB) to predict early postoperative outcomes for children undergoing congenital heart surgery. The study enrolled 73 children (ages 0.1-72 months) undergoing corrective or palliative cardiac surgery requiring CPB. Laboratory and hemodynamic variables were analyzed at the time of successful weaning from CPB. Using near-infrared spectroscopy, cerebral, renal, and splanchnic rSO2 values were obtained simultaneously. Early postoperative outcome measures included the maximum vasoactive inotropic score (VIS(max)) during the first 36 postoperative hours, the duration of mechanical ventilation, and the postoperative hospital length of stay. In the univariate analysis, cerebral, renal, and splanchnic rSO2 values correlated significantly with early postoperative outcomes. However, splanchnic rSO2 was the only independent factor predicting VIS(max) (ß = -0.302, P = 0.021), duration of mechanical ventilation (ß = -0.390, P = 0.002), and postoperative hospital length of stay (ß = -0.340, P = 0.001) by multivariate analyses. Splanchnic rSO2 had a larger receiver operating characteristic area under the curve (AUC) for determining high VIS(max), prolonged mechanical ventilation, and longer postoperative hospital stay (AUC 0.775, 0.792, and 0.776, respectively) than cerebral (AUC 0.630, 0.638, and 0.632, respectively) and renal (AUC 0.703, 0.716, and 0.715, respectively) rSO2. After weaning from CPB, splanchnic rSO2 may be superior to rSO2 measured from brain and kidney in predicting an increased requirement for vasoactive inotropic support, a prolonged mechanical ventilation, and a longer postoperative hospital stay for children.

Postoperative alterations in ventriculoarterial coupling are an indicator of cardiovascular outcomes in liver transplant recipients.

BACKGROUND: Liver transplantation (LT) increases the heart and vessel workload in patients with cirrhotic cardiomyopathy. While the interaction of the left ventricle (LV) with the arterial system (ventriculoarterial coupling, VAC) is a key determinant of cardiovascular performance, little is known about changes in VAC after LT. Therefore, we evaluated the relationship between VAC after LT and cardiovascular outcomes. METHODS: 344 consecutive patients underwent echocardiographic assessments before and within 30 days after LT. Non-invasive arterial elastance (Ea), LV end-systolic elastance (Ees), and LV end-diastolic elastance (Eed) were calculated. The postoperative outcomes included the development of major adverse cardiovascular events (MACE) and the length of stay in the intensive care unit and hospital. RESULTS: A total of 240 patients were included in the analyses. After LT, Ea increased by 16% (P < 0.001), and Ees and contractility index of systolic velocity (S') increased by 18% (P < 0.001) and 7% (P < 0.001), respectively. The Eed increased by 6% (P < 0.001). The VAC remained unchanged (0.56 to 0.56, P = 0.912). Of these patients, 29 had MACE, and those with MACE had significantly higher postoperative VAC. Additionally, a higher postoperative VAC was an independent risk factor for a longer postoperative hospital stay (P = 0.038). CONCLUSIONS: These data suggest that ventriculoarterial decoupling is associated with poor postoperative outcomes after LT.

Beat-to-beat tracking of systolic blood pressure using noninvasive pulse transit time during anesthesia induction in hypertensive patients.

BACKGROUND: Pulse transit time (PTT) has been reported to show good agreement with arterial blood pressure (BP) in awake humans. We evaluated whether noninvasive beat-to-beat PTT accurately correlated with invasively measured continuous arterial BP during anesthesia induction in hypertensive patients. METHODS: Twenty-three hypertensive patients who were scheduled for kidney transplant were enrolled. Radial arterial BP, electrocardiogram, and finger pulse oximetric plethysmography were simultaneously recorded. PTT was measured as the time interval from the R-wave peak on the electrocardiogram to the maximal upslope of the photoplethysmogram. Relationships between beat-to-beat PTT and BP were evaluated by correlation and receiver operating characteristic (ROC) curve analysis. RESULTS: During anesthesia induction, changes in PTT were directly proportional to changes in BP: when BP decreased, PTT lengthened, and vice versa. The inverse of PTT demonstrated significantly better correlation with systolic BP than with mean BP (r = 0.81 ± 0.11 vs r = 0.72 ± 0.17; P < 0.001) or diastolic BP (r = 0.81 ± 0.11 vs r = 0.52 ± 0.24; P < 0.001). The inverse of PTT was more highly correlated with decreasing than with increasing changes in systolic BP (r = 0.83 ± 0.12 vs r = 0.68 ± 0.20; P = 0.001). The ROC curve analysis revealed that a 15% increase in PTT during anesthesia induction could detect a ≥30% decrease in systolic BP, with an area under the ROC curve of 0.85. CONCLUSION: Beat-to-beat PTT was fairly well correlated with invasive systolic BP and could predict a reduction in systolic BP during anesthesia induction. Beat-to-beat PTT may show potential as a useful noninvasive index of systolic BP when invasive BP is unavailable in high-risk hypertensive patients.