Performance of the new biological small- and wide-angle X-ray scattering beamline 13A at the Taiwan Photon Source.

Recent developments in the instrumentation and data analysis of synchrotron small-angle X-ray scattering (SAXS) on biomolecules in solution have made biological SAXS (BioSAXS) a mature and popular tool in structural biology. This article reports on an advanced endstation developed at beamline 13A of the 3.0 GeV Taiwan Photon Source for biological small- and wide-angle X-ray scattering (SAXS-WAXS or SWAXS). The endstation features an in-vacuum SWAXS detection system comprising two mobile area detectors (Eiger X 9M/1M) and an online size-exclusion chromatography system incorporating several optical probes including a UV-Vis absorption spectrometer and refractometer. The instrumentation and automation allow simultaneous SAXS-WAXS data collection and data reduction for high-throughput biomolecular conformation and composition determinations. The performance of the endstation is illustrated with the SWAXS data collected for several model proteins in solution, covering a scattering vector magnitude q across three orders of magnitude. The crystal-model fittings to the data in the q range ∼0.005-2.0 Å-1 indicate high similarity of the solution structures of the proteins to their crystalline forms, except for some subtle hydration-dependent local details. These results open up new horizons of SWAXS in studying correlated local and global structures of biomolecules in solution.

Da Vinci SP robotic approach to colorectal surgery: two specific indications and short-term results.

BACKGROUND: Da Vinci® Single Port (dvSP) was recently developed. Its application in colorectal surgery is under investigation. The aim of this study was to explore the safety and feasibility of dvSP for intersphincteric (dvSP-ISR), right colectomy (dvSP-RC), and transverse colectomy (dvSP-TC). Surgical indication and short-term results were analyzed. METHODS: All consecutive patients from a prospective database of patients who underwent dvSP-ISR, dvSP-RC, and dvSP-TC at Korea University Anam Hospital from November 2020 to December 2021, were analyzed. Perioperative, pathological, and oncological short-term outcomes were analyzed. RESULTS: A total of 7 dvSP-ISR, 5 dvSP-RC, and 1 dvSP-TC were performed. Median age was 56.0 (55.0-61.0) years for the dvSP-ISR and 54.0 (44.7-63.5) years for the dvSP-RC/TC. Median body mass index was 22.8 (17.1-24.8) kg/m2 for the dvSP-ISR and 23.6 (20.8-26.9) kg/m2 for the dvSP-RC/TC. All dvSP-ISR patients received neoadjuvant long-course chemoradiotherapy, including one patient with squamocellular carcinoma who was treated with 5-fluorouracil (5-FU)/mitomycin. All other patients, excluding one dvSP-RC patient with Crohn's disease, had an adenocarcinoma. Median operation time was 280 (240-370) minutes for the dvSP-ISR and 220 (201-270) minutes for the dvSP-RC/TC. Estimated blood loss was insignificant. No intraoperative complications or conversions to multiport/open surgery was reported. Median post-operative stay was 7.0 (6.0-10.0) days for the dvSP-ISR and 5.0 (4.0-6.7) days for the dvSP-RC/TC. Quality of mesorectum was complete for six patients, and nearly complete for one. Median number of retrieved lymph nodes were 21 (17-25) for the dvSP-ISR and 28 (24-49) for the dvSP-RC/TC. Proximal and distal resection margins were tumor free. Four patients experienced post-operative complications not related to the platform which were: ileus, voiding dysfunction, infected pelvic hematoma, and wound infection. Median follow-up was 9 (6-11) months and 11 (7-17) months for the dvSP-ISR and dvSP-RC/TC, respectively. Two patients had systemic recurrence; all others were tumor free. CONCLUSIONS: The dvSP platform is safe and feasible for intersphincteric resection with right lower quadrant access, and right/transverse colectomy with suprapubic access. Further studies are needed to evaluate benefit differences compared to multiport robotic platform.

Robotic-assisted resection for beyond TME rectal cancer: a novel classification and analysis from a specialized center.

Locally advanced rectal cancer often requires an extended resection beyond the total mesorectal excision plane (bTME) to obtain clear resection margins. We classified three types of bTME rectal cancer following local disease diffusion: radial (adjacent pelvic organs), lateral (pelvic lateral lymph nodes) and longitudinal (below 3.5 cm from the anal verge, submitted to intersphincteric resection). The primary aim of this study was to evaluate the application of robotic surgery to the three types of bTME regarding the short and long-term oncological outcomes. Secondary aim was to identify survival prognostic factors for bTME rectal cancers. A total of 137 patients who underwent robotic-assisted bTME procedures between 2008 and 2018 were extracted from a prospectively collected database. Patient-related, operative and pathological factors were assessed. Morbidity was moderately high with 66% of patients reporting postoperative complications. Median follow up was 47 months (IQR, 31.5-66.5). Local recurrence rate was 15.3% with a statistical difference between the three types of bTME (p = 0.041). Disease progression/distant metastasis rate was 33.6%. Overall survival was significantly different (p = 0.023) with 1- and 3-years rates of: 77.8% and 55.0% (radial; n = 19); 96.6% and 84.8% (lateral; n = 30); 97.7% and 86.9% (longitudinal; n = 88). No statistical difference was observed for disease-free survival (p = 0.897). Local recurrence-free survival was significantly different between the groups (p = 0.031). Multivariate analysis showed that (y)pT (p = 0.028; HR (95% CI) 5.133 (1.192-22.097)), (y)pN (p = 0.014; HR (95% CI) 2.835 (1.240-6.482)) and type of bTME were associated to OS whilst (y)pT (p = 0.072) and type of bTME were not associated to LRFS.

Use of real-world registry data: a hernia mesh example.

PURPOSE: Clinical performance of hernia mesh devices is poorly understood due to a lack of relevant clinical trial and real-world data (RWD). Registries offer a means to capture longitudinal data in real-world practice. This report highlights the need for data quality, completeness, and appropriate analysis methodology for more accurate and informed interpretation of RWE of medical devices. METHODS: Hernia mesh registry data were used to cross-tabulate the 30-day infection rate of patients who received one of four mesh types. RESULTS: Initial data review suggested lower infection rate for permanent mesh versus absorbable mesh. Additional registry RWD were factored into the analysis, providing more context in the interpretation of the results. CONCLUSIONS: High-quality registries can be used to generate real-world evidence (RWE) to support surveillance and other regulatory decisions.

Understanding the patient perspective after ventral hernia repair.

PURPOSE: More than 350,000 ventral hernia repairs are performed in the U.S. each year. However, long-term quality of life of patients living with hernia repair is less known. Follow-up using patient-reported outcomes (measures) is an important representation of the patient experience and can inform quality improvements of hernia treatments. This study aims to understand the patients' experience after ventral hernia repair, to enhance quality of care and long-term hernia treatment outcomes. METHODS: To better understand long-term outcomes of ventral hernia repair and to enhance an existing PRO tool, two rounds of semi-structured interviews and focus groups were conducted. In total, 22 patients who had ventral hernia repair were enrolled. The patient perspectives obtained were grouped into themes to inform the further development of the PRO tool. Data were transcribed and analyzed using atlas.ti and Microsoft Word. RESULTS: Ten major themes were identified in this analysis. Patients' quality of life was impacted by hernia repairs and hernia recurrences, including chronic pain, effects on daily activities and social relationships, and the challenge in finding new treatments. The lack of provider-patient communication and patient understanding of hernia repairs highlighted the need for providing patients with more comprehensive information regarding repair options and outcomes prior to surgery. CONCLUSION: PRO assessments and meaningful communications between the physician and the patient can provide a comprehensive benefit-risk assessment prior to surgery, and may also improve patient understanding of what to expect during recovery from surgery.

Genomic screening of Fabry disease in young stroke patients: the Taiwan experience and a review of the literature.

BACKGROUND AND PURPOSE: Fabry disease is an X-linked disease, and enzyme-based screening methods are not suitable for female patients. METHODS: In total, 1000 young stroke patients (18-55 years, 661 with ischaemic stroke and 339 with hypertensive intracerebral hemorrhage) were recruited. The Sequenom iPLEX assay was used to detect 26 Fabry related mutation genes. The frequency of Fabry disease in young stroke was reviewed and compared between Asian and non-Asian countries. RESULTS: Two male patients with ischaemic stroke were found to have a genetic mutation of IVS4+919G>A. There was no α-galactosidase A (GLA) gene mutation in female patients. The frequency in Asian stroke patients was 0.62% (male vs. female 0.63% vs. 0.58%) with 0.72% for ischaemic stroke and none for hemorrhagic stroke, compared to 0.88% (0.77% vs. 1.08%) with 0.83% for ischaemic stroke and 1.40% for hemorrhagic stroke reported in western countries. CONCLUSION: IVS4+919G>A is the GLA mutation in Taiwanese young ischaemic stroke patients. Fabry disease is more frequent among non-Asian patients compared to Asian patients.

Phase-shifting differential interference contrast microscope with Savart shear prism and rotatable analyser.

A novel differential interference contrast microscope (DICM) is proposed in this research. It is constituted by inserting a Savart shear prism between the objective and sample of a polarising microscope having a rotatable analyser as the phase-shifter, and it is with the ability to enhance image contrast using the principle of shearing interferometry. This letter is to introduce the configuration, interpret the interference patterns and present the experimental setup of the DICM. In addition, this letter is to display the experimental results from the uses of the setup; the results demonstrate the validity and ability of the DICM.

Quantum spin liquids unveil the genuine Mott state.

The localization of charge carriers by electronic repulsion was suggested by Mott in the 1930s to explain the insulating state observed in supposedly metallic NiO. The Mott metal-insulator transition has been subject of intense investigations ever since1-3-not least for its relation to high-temperature superconductivity4. A detailed comparison to real materials, however, is lacking because the pristine Mott state is commonly obscured by antiferromagnetism and a complicated band structure. Here we study organic quantum spin liquids, prototype realizations of the single-band Hubbard model in the absence of magnetic order. Mapping the Hubbard bands by optical spectroscopy provides an absolute measure of the interaction strength and bandwidth-the crucial parameters that enter calculations. In this way, we advance beyond conventional temperature-pressure plots and quantitatively compose a generic phase diagram for all genuine Mott insulators based on the absolute strength of the electronic correlations. We also identify metallic quantum fluctuations as a precursor of the Mott insulator-metal transition, previously predicted but never observed. Our results suggest that all relevant phenomena in the phase diagram scale with the Coulomb repulsion U, which provides a direct link to unconventional superconductivity in cuprates and other strongly correlated materials.

Low-Energy Excitations in Quantum Spin Liquids Identified by Optical Spectroscopy.

The electrodynamic response of organic spin liquids with highly frustrated triangular lattices has been measured in a wide energy range. While the overall optical spectra of these Mott insulators are governed by transitions between the Hubbard bands, distinct in-gap excitations can be identified at low temperatures and frequencies, which we attribute to the quantum-spin-liquid state. For the strongly correlated ß^{'}-EtMe_{3}Sb[Pd(dmit)_{2}]_{2}, we discover enhanced conductivity below 175 cm^{-1}, comparable to the energy of the magnetic coupling J≈250 K. For ω→0, these low-frequency excitations vanish faster than the charge-carrier response subject to Mott-Hubbard correlations, resulting in a dome-shaped band peaked at 100 cm^{-1}. Possible relations to spinons, magnons, and disorder are discussed.

Leukocytes as a reservoir of circulating oncogenic DNA and regulatory targets of tumor-derived extracellular vesicles.

Essentials Tumor-bearing mice were employed to follow oncogenic HRAS sequences in plasma, and blood cells. Cancer DNA accumulated in leukocytes above levels detected in exosomes, platelets and plasma. Extracellular vesicles and nucleosomes are required for uptake of tumor DNA by leukocytes. Uptake of tumor-derived extracellular vesicles by leukocytes triggers coagulant phenotype. SUMMARY: Background Tumor-derived extracellular vesicles (EVs) and free nucleosomes (NSs) carry into the circulation a wealth of cancer-specific, bioactive and poorly understood molecular cargoes, including genomic DNA (gDNA). Objective Here we investigated the distribution of extracellular oncogenic gDNA sequences (HRAS and HER2) in the circulation of tumor-bearing mice. Methods and Results Surprisingly, circulating leukocytes (WBCs), especially neutrophils, contained the highest levels of mutant gDNA, which exceeded the amount of this material recovered from soluble fractions of plasma, circulating EVs, platelets, red blood cells (RBCs) and peripheral organs, as quantified by digital droplet PCR (ddPCR). Tumor excision resulted in disappearance of the WBC-associated gDNA signal within 2-9 days, which is in line with the expected half-life of these cells. EVs and nucleosomes were essential for the uptake of tumor-derived extracellular DNA by neutrophil-like cells and impacted their phenotype. Indeed, the exposure of granulocytic HL-60 cells to EVs from HRAS-driven cancer cells resulted in a selective increase in tissue factor (TF) procoagulant activity and interleukin 8 (IL-8) production. The levels of circulating thrombin-antithrombin complexes (TAT) were markedly elevated in mice harboring HRAS-driven xenografts. Conclusions Myeloid cells may represent a hitherto unrecognized reservoir of cancer-derived, EV/NS-associated oncogenic gDNA in the circulation, and a possible novel platform for liquid biopsy in cancer. In addition, uptake of this material alters the phenotype of myeloid cells, induces procoagulant and proinflammatory activity and may contribute to systemic effects associated with cancer.

"Snowmelt Sign" and "Corkscrew Microvessels" Predicting Epithelium Regeneration After Acute Rejection of Small-Bowel Transplantation: A Case Report.

Intestinal failure characterized by inadequate maintenance of nutrition via normal intestinal function comprises a group of disorders with many different causes. If parenteral nutrition dependency develops, which is associated with higher mortality and complications, it is considered for intestine transplantation. However, the graft failure rate is not low, and acute cellular rejection is one of the most important reasons for graft failure. As a result, early identification of rejection and timely modification of anti-rejection medications have been considered to be associated with better graft and patient survival rates. The diagnostic gold standard for rejection is mainly based on histology, but hours of delay by pathology may occur. Some researchers investigated the association of endoscopic images with graft rejection to provide timely diagnosis. In this study, we present the first case report with characteristic features under magnifying endoscopy with a narrow-band imaging system to predict epithelial regeneration and improvement of graft rejection in a patient with small-bowel transplantation.

Quantum-mechanical analysis of effect of alloying elements on ε-martensite start temperature of steels.

With regard to the transformation mechanism of austenitic high manganese steel, the prediction of the ε-martensite start temperature is a critical consideration in alloy design. Evaluation of the ε-martensite start temperature makes it possible to predict the microstructure and to understand the phase transformation occurring during deformation. Here we use the quantum mechanical calculation of random alloys to understand the physics for ε-martensitic transformation in steels. We could find the linear relationship between the measured ε-martensite start temperatures and the crystal structure stability for various compositions. We also could estimate the effect of several alloying elements. It is expected that the effect of decreasing the temperatures for the same amount of alloying elements addition will be larger moving farther from Group VIII. By creating a free-energy model that reflects the temperature effect, we were able to calculate the average driving force required for the ε-martensitic transformations.

Temporary work and depressive symptoms in South Korean workers.

BACKGROUND: In many countries, including South Korea, labour market changes have led to an increase in unstable, temporary jobs. There is evidence that workers in such jobs may experience poorer mental health than those in more stable employment. AIMS: To investigate the association between temporary employment and depressive symptoms in South Korean workers. METHODS: We analysed data from the 2010-2014 Korean Welfare Panel Study (KOWEPS). Employment type was categorized into workers paid per day of labour (day labourers), those on short-term contracts (fixed-term workers) and permanent workers. The association between employment type and depressive symptoms, measured using the Center for Epidemiological Studies Depression scale (CES-D 11), was examined using the generalized estimating equation model. RESULTS: A total of 3756 workers aged 20-59 were included in the 2010 baseline population. Day labourers had the highest mean CES-D 11 score, followed by fixed-term workers and permanent workers. With the day labourer group as reference, fixed-term workers (ß: -1.5027, P < 0.001) and permanent workers (ß: -2.1848, P < 0.001) showed statistically significant decreases in depression scores. CONCLUSIONS: Compared with day labourers, fixed-term workers and permanent workers had progressively lower depression scores. The findings of this study suggest that mental health inequalities based on employment type exist in South Korea.

Caveolin-1 serves as a negative effector in senescent human gingival fibroblasts during Fusobacterium nucleatum infection.

It is well established that aging is associated with increased susceptibility to infectious diseases. Fusobacterium nucleatum is a well-known bacterial species that plays a central bridging role between early and late colonizers in the human oral cavity. Further, the ability of F. nucleatum to invade gingival fibroblasts (GFs) is critical to the development of periodontal diseases. However, the mechanisms underlying the age-related infection of GFs by F. nucleatum remain unknown. We used young (fourth passage) and senescent (22nd passage) GFs to investigate the mechanisms of F. nucleatum infection in aged GFs and first observed increased invasion of F. nucleatum in senescent GFs. We also found that the co-localization of caveolin-1 (Cav-1), a protein marker of aging, with F. nucleatum and the knockdown of Cav-1 in GFs reduced F. nucleatum invasion. Additionally, F. nucleatum infection triggered the production of reactive oxygen species (ROS) through activation of NADPH oxidase in GFs, but senescent GFs exhibited significantly lower levels of NADPH oxidase activity and ROS production compared with young GFs in both the uninfected and infected conditions. Also, senescent GFs exhibited a decline in proinflammatory cytokine production and extracellular signal regulated kinase (ERK) phosphorylation following F. nucleatum infection. Interestingly, the knockdown of Cav-1 in senescent GFs increased NADPH oxidase activity and caused the upregulation of interleukin-6 and interleukin-8 and the phosphorylation of ERK. Collectively, the increased expression of Cav-1 might play a critical role in F. nucleatum invasion and could hinder the host response in senescent GFs.

Manufacturing method affects mitochondrial DNA release and extracellular vesicle composition in stored red blood cells.

BACKGROUND AND OBJECTIVES: Damage-associated molecular patterns (DAMPs) are found in transfusion products, but their potential impacts are not fully understood. We examined the influence of manufacturing method on levels of mitochondrial (mt) DNA and extracellular vesicle (EV) DAMPs in red cell concentrates (RCCs). MATERIALS AND METHODS: Eighty-seven RCCs were prepared using nine different methods (6-15 units/method), including three apheresis, five whole blood (WB)-derived leucoreduced (LR) and one WB-derived non-LR method. On storage days 5 and 42, levels of mtDNA (by PCR) and number and cell of origin of EVs (by flow cytometry) were assessed in RCC supernatants. RESULTS: There was a 100-fold difference in mtDNA levels among methods, with highest levels in non-LR, followed by MCS+ and Trima apheresis RCCs. There was a 10-fold difference in EV levels among methods. RBC-derived CD235a+ EVs were found in fresh RCCs and increased in most during storage. Platelet-derived CD41a+ EVs were highest in non-LR and Trima RCCs and did not change during storage. WBC-derived EVs were low in most RCCs; CD14+ EVs increased in several RCCs during storage. CONCLUSION: DAMPs in RCCs vary by manufacturing method. MtDNA and EV could be informative quality markers that may be relevant to RCC immunomodulatory potential.

Effect of dehydration on the development of collaterals in acute middle cerebral artery occlusion.

BACKGROUND AND PURPOSE: Recent large series studies have demonstrated that dehydration is common amongst stroke subjects and is associated with poor outcome. However, the effects of hydration status on the development of collaterals have never been discussed. In this study, the hypothesis that hydration status is an important factor for developing collaterals after acute middle cerebral artery (MCA) infarction was tested. METHODS: Eighty-seven patients with acute infarction due to occlusion of the MCA were enrolled. Two collateral markers, posterior cerebral artery (PCA) laterality and fluid-attenuated inversion recovery hyperintense vessels (HVs) were assessed from magnetic resonance imaging. Dehydration status was defined by a nitrogen to creatinine ratio ≧ of 15. The associations between dehydration status and the development of collaterals were estimated. RESULTS: Sixty-one of 87 patients (70.1%) were identified as dehydrated. The development of PCA laterality and HVs shows a significant difference between dehydrated and euhydrated patients. A serum nitrogen to creatinine ratio <15, diastolic blood pressure and the presence of a dense MCA on computed tomography were significantly associated with the development of PCA laterality. A serum nitrogen to creatinine ratio <15, the initial National Institutes of Health Stroke Scale score, the presence of a dense MCA and calcifications of the internal carotid artery on computed tomography were significantly associated with the development of HVs. Dehydration remained an independent negative predictor for the development of PCA laterality and HVs in the multivariate analysis. CONCLUSIONS: Hydration status is associated with the development of collateral flow after acute MCA occlusion. This preliminary study provides an imaging clue that hydration status and early hydration therapy could be important for acute stroke management.

A home-based training programme improves family caregivers' oral care practices with stroke survivors: a randomized controlled trial.

OBJECTIVES: Stroke survivors experience poor oral health when discharged from the hospital to the community. The aim of this study was to evaluate the effectiveness of a home-based oral care training programme on knowledge, attitude, self-efficacy and practice behaviour of family caregivers. METHODS: A randomized controlled trial was conducted. The experimental group consisted of 48 family caregivers who received the home-based oral care training programme, and the control group consisted of 46 family caregivers who received routine oral care education. The outcomes were measured by the Knowledge of Oral Care, Attitude towards Oral Care, Self-Efficacy of Oral Care and Behaviour of Oral Care before the training programme, and at one and two months afterwards. The data were analysed using mixed model anova to determine differences in the outcomes between the two groups. RESULTS: The findings demonstrated that the intervention group had more knowledge (t = 8.80, P < 0. 001), greater self-efficacy (t = 3.53, P < 0.01) and better oral care behaviour (t = 11.93, P < 0.001) than the control group at one and two months, with statistically significant differences in oral care knowledge, self-efficacy and behaviour outcome over time. The attitude of the intervention group towards oral care practice was generally positive (mean of baseline and two month = 12.9 and 14.7), but no significant difference in attitude change between the control and intervention groups (t = 1.56, P = 0.12). The treatment interaction effect was significant for the family caregivers' behaviour of oral care at one and two months of the intervention for both groups. CONCLUSION: Our individualized home-based oral care education can achieve significant improvements in oral care knowledge and self-efficacy among family caregivers of stroke survivors, and it can sufficiently empower them to modify their oral care practices in a home-based healthcare environment.

Intentional examination of esophagus by narrow-band imaging endoscopy increases detection rate of cervical inlet patch.

Foci of heterotopic gastric mucosa have been identified at different sites in the human body and the most common location is the proximal esophagus which is referred to as cervical inlet patch (CIP). The true prevalence of CIP varies and it is usually incidental findings during endoscopy. Because CIP is always asymptomatic, it was believed to be of little clinical relevance. However, emerging studies have described the acid-secreting characteristics of heterotopic gastric mucosa and associations of CIP with gastroesophageal reflux disease (GERD). In addition, complications such as stricture, fistula, infection, mucosal hyperplasia, and malignant transformation have been reported. In this study, we investigated the prevalence of CIP, its associations with clinical manifestations, and the effect of intentional screening upper esophagus by magnifying endoscopy-narrow-band imaging (ME-NBI) system. Consecutive healthy adults who underwent panendoscopy were separated into two groups. Patients in group I (n = 471) were examined by an endoscopist who intended to find CIPs by ME-NBI. Patients in group II (n = 428) were examined by two endoscopists who were unaware of the study and performed white-light imaging endoscopy. Participants provided questionnaires on GERD-related symptoms. Higher CIP prevalence (11.7% vs. 1.9%, P < 0.0001) and longer duration of esophageal examination (mean ± standard deviation, 17.50 ± 12.40 vs. 15.24 ± 10.78 seconds, P = 0.004) were noted in group I than in group II. Analyzing group I patients revealed the higher prevalences of reflux symptoms (32.7% vs. 18.3%, P = 0.013) and erosive esophagitis (43.6% vs. 25.5%, P = 0.005) in patients with CIP than in those without. CIP was not associated with globus or dysphagia symptoms. More small CIPs (< 5 mm) were detected by ME-NBI than by white-light imaging (85.3% vs. 41.4%, P = 0.001). In conclusion, CIP prevalence was not low under intentional ME-NBI examination of the upper esophagus. The clinical relevance of CIP and its association with GERD require further investigation.

Development of a mitochondrial DNA real-time polymerase chain reaction assay for quality control of pathogen reduction with riboflavin and ultraviolet light.

BACKGROUND AND OBJECTIVES: Transfusion is associated with a risk of infection and alloimmunization. Pathogen reduction using riboflavin and UV light (Mirasol treatment) inactivates pathogens and leucocytes. With increasing adoption of the technology in clinical use, regulatory agencies have recommended the introduction of quality control measures to monitor pathogen reduction efficacy. We sought to develop a real-time PCR-based assay to document the impact of pathogen reduction on the mitochondrial genome in blood components. MATERIALS AND METHODS: DNA was extracted from platelet and plasma components before and after treatment with riboflavin and UV light. Inhibition of PCR amplification of mitochondrial DNA (mtDNA) in short- and long-amplicon target regions, ranging from under 200 base pairs (bp) to over 1800 bp, was measured in treated relative to untreated components. RESULTS: Pathogen reduction of platelets using riboflavin and UV light resulted in inhibition of PCR amplification of long-amplicon mtDNA targets, demonstrating approximately 1 log reduction of amplification relative to untreated products. Amplification of short-amplicon mtDNA targets was not affected by treatment. Evaluation of 110 blinded platelet samples from the PREPAReS clinical trial resulted in prediction of treatment status with 100% accuracy. Pathogen reduction of plasma components resulted in similar levels of PCR inhibition, while testing of 30 blinded plasma samples resulted in prediction of treatment status with 93% accuracy. CONCLUSION: A differential sized amplicon real-time PCR assay of mitochondrial DNA effectively documents nucleic acid damage induced by Mirasol treatment of platelets. The use of the assay for plasma product pathogen reduction requires further investigation.