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This systematic review and meta-analysis assesses the effectiveness of no or low-dose versus high-dose aspirin on the incidence of coronary artery aneurysms (CAAs), intravenous immunoglobulin (IVIG) resistance, hospital stay length, and fever duration during the acute phase of Kawasaki disease. Our review adheres to the Preferred Reporting Items for Systematic Reviews guidelines. The PubMed and Google Scholar databases were comprehensively searched to identify relevant studies in the literature, including observational studies and randomized controlled trials (RCTs). The primary outcome was the incidence of CAAs. The secondary outcomes were the hospital stay length, fever duration, and IVIG resistance. The risk of bias was assessed using the Newcastle-Ottawa scale for cohort studies and Cochrane's Risk of Bias Tool for RCTs. The data were analyzed using the Review Manager software. Twelve studies with a total of 68,495 participants met the inclusion criteria. The incidences of CAAs (odds ratio [OR] = 0.93; 95% confidence interval [CI] = 0.64-1.34) and IVIG resistance (OR = 1.46; 95% CI = 1.00-2.12) did not differ significantly between no or low-dose versus high-dose aspirin in treating acute KD. Moreover, the fever durations (mean difference [MD] = 3.55 h; 95% CI = -7.99-15.10) and hospital stay lengths (MD = -0.54 days; 95% CI = -2.50-1.41) were similar in the no and low-dose aspirin group compared to the high-dose aspirin group. Our review indicates that there are no significant differences in the incidences of CAA and IVIG resistance, fever durations, and hospital stay lengths between no or low-dose versus high-dose aspirin in treating the acute phase of KD.

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BACKGROUND: Dry eye disease (DED) is a complication of dyslipidemia (DLP) that is caused by metabolic syndrome and increased inflammation. This research aimed to assess leukocyte and systemic inflammation index ratios as potential biomarkers for systemic inflammation in dyslipidemia patients with dry eye disease (DLP-DED). METHODS: Several blood biomarkers were studied in 32 patients with DLP-DED (study group) and 63 patients with DLP-only (control group). The evaluated blood biomarkers included specific systemic inflammation index ratios, such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and neutrophil-to-lymphocyte and platelet ratio (NLPR), and lipid profiles, such as total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG), albumin (ALB), and C-reactive protein (CRP) levels. RESULTS: Lymphocyte levels were significantly greater in the DLP-DED group than in the DLP-only group (P = 0.044). In addition, a significant negative correlation between HDL and the NLPR (P = 0.007; r= -0.428) and a significant negative correlation between the serum ALB concentration and the PLR (P = 0.008; r= -0.420) were identified as potential inflammatory predictors of DLP-DED. CONCLUSION: The findings of this study suggest that patients with DLP-DED may benefit from routine blood monitoring of their elevated lipid profile and blood inflammatory biomarkers, such as CRP, leukocytes, and systemic inflammation index ratios (NLR, PLR, MLR, and NLPR), to reduce the complications of DLP on ocular health. The correlation data suggest that the NLPR, PLR, serum ALB concentration, and serum HDL concentration may be valuable inflammatory biomarkers in DLP-DED patients. More research is required to ascertain the significance of the NLR, PLR, MLR, and NLPR and the additive role that leukocytes play.

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Background: The inflammation plays a role in the pathophysiology of type-2 diabetes progression, and the mechanism remains unclear. The systemic immune-inflammation index (SII) is a novel inflammatory marker for type 2 diabetes patients and integrates multiple indicators in complete blood counts and routine blood tests. Aim: Since there is no international diagnostic standard for dry eye disease (DED), this study uses low-cost inflammatory blood biomarkers to investigate the correlation between SII and DM2-DED and determine the diagnosis indices of other biomarkers in DM2-DED. Methodology: A case-control retrospective analysis of totel patients n = 293 randomly selected and categorized into four groups: DED, DM2, DM2-DED, and healthy subjects. Demographic and blood biomarker variables were classified as categorical and continuous variables. The platelet-to-lymphocyte ratio (PLR), lymphocytes-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio (NLR), and SII were calculated platelet count multiply by NLR and analyzed for their correlation for all groups. Results: Focusing on DM2-DED patients was more common in females, 59.6%, than in males, 40.2%. The mean ages were 60.7 ± 11.85 years, a statistically significant difference with all groups. In the study group DM2-DED, there was an increase in all blood markers compared to all remaining groups except PLR. Only neutrophil, hemoglobin A1c (HbA1c), and fasting blood sugar levels were statistically significant differences in DM2-DED patients (p > 0.001, p < 0.001, and p < 0.001, respectively) compared to all groups. There was a positive correlation between HbA1c and PLR, HbA1c and NLR, and HbA1c and SII (r = 0.037, p = 0.705; r = 0.031, p = 0.754; and r = 0.066, p < 0.501, respectively) in the DM2-DED group. Conclusion: This study demonstrated that elevated SII values were linked to elevated HbA1c in DM2-DED patients. The potential of SII and HbA1c as early diagnostic indicators for ocular problems associated with diabetes mellitus is highlighted by their favorable connection in diagnosing DM2-DED.

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Osteoarthritis (OA) is a long-term, persistent joint disorder characterized by bone and cartilage degradation, resulting in tightness, pain, and restricted movement. Current attempts in cartilage regeneration are cell-based therapies using stem cells. Multipotent stem cells, such as mesenchymal stem cells (MSCs), and pluripotent stem cells, such as embryonic stem cells (ESCs), have been used to regenerate cartilage. However, since the discovery of human-induced pluripotent stem cells (hiPSCs) in 2007, it was seen as a potential source for regenerative chondrogenic therapy as it overcomes the ethical issues surrounding the use of ESCs and the immunological and differentiation limitations of MSCs. This literature review focuses on chondrogenic differentiation and 3D bioprinting technologies using hiPSCS, suggesting them as a viable source for successful tissue engineering. METHODS: A literature search was conducted using scientific search engines, PubMed, MEDLINE, and Google Scholar databases with the terms 'Cartilage tissue engineering' and 'stem cells' to retrieve published literature on chondrogenic differentiation and tissue engineering using MSCs, ESCs, and hiPSCs. RESULTS: hiPSCs may provide an effective and autologous treatment for focal chondral lesions, though further research is needed to explore the potential of such technologies. CONCLUSIONS: This review has provided a comprehensive overview of these technologies and the potential applications for hiPSCs in regenerative medicine.

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INTRODUCTION: To date few studies have investigated the correlation between inflammatory markers and lipoproteins in the serum of age-related macular degeneration (AMD) patients, often reporting conflicting findings. This study aimed to investigate the correlation between lipid analytes and C-reactive protein (CRP) levels in individuals diagnosed with dry AMD. METHODS: A standard clinical lipid panel (total cholesterol, triglycerides, high-density lipoprotein [HDL], and low-density lipoproteins) and CRP laboratory results were retrospectively collected from the medical records of patients with dry AMD and age- and sex-matched controls. RESULTS: The study included 90 patients with dry AMD and 270 patients without AMD. In univariate analysis, CRP showed a higher mean value in cases than in controls. After adjusting for age and sex, CRP and triglyceride levels showed significant differences between cases and controls. Pearson's correlation analysis revealed a significant negative correlation between CRP and HDL levels in the dry AMD group (n=90). Other lipid analytes showed no significant correlations with CRP. CONCLUSION: Our findings add to the growing body of evidence linking inflammation to AMD. Although it is unclear whether changes in serum CRP and triglyceride levels are the causes or effects, monitoring both analytes may be beneficial as an early disease predictor, especially in individuals with a family history of AMD. The negative correlation between CRP and HDL (i.e., inflammation and good cholesterol) may be targeted for future therapies.

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Oral cancer is one of the most common cancer types. Many factors can express certain genes that cause the proliferation of oral tissues. Overexpressed genes were detected in oral cancer patients; three were highly impacted. FAP, FN1, and MMP1 were the targeted genes that showed inhibition results in silico by ginsenoside C and Rg1. Approved drugs were retrieved from the DrugBank database. The docking scores show an excellent interaction between the ligands and the targeted macromolecules. Further molecular dynamics simulations showed the binding stability of the proposed natural products. This work recommends repurposing ginsenoside C and Rg1 as potential binders for the selected targets and endorses future experimental validation for the treatment of oral cancer.

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BACKGROUND: Chronic myeloid leukemia (CML) is a prevalent hematological malignancy known for the presence of the Philadelphia chromosome and activation of the BCR-Abl kinase activity. Although tyrosine kinase inhibitors are widely used as the standard treatment, resistance remains a concern among certain patients. This study aimed to investigate the gene expression profile of a group of CML patients in comparison to a control group in order to identify novel candidate genes associated with the disease. METHODS: Whole transcriptome sequencing was performed, and gene expression levels were validated using quantitative real-time PCR. Additionally, single nucleotide and insertion/deletion variants were analyzed in the selected candidate genes among 10 CML patients and 4 healthy control subjects. RESULTS: Analysis revealed a set of differentially expressed genes, whose up- or downregulation was further confirmed by qRT-PCR. Among the upregulated genes in the patient group were ribosomal protein like (RPL) members, specifically RPL9, RPL34, RPL36A, and RPL39, while downregulation was observed in CCDC170, LDB1, and SBF1 compared to the healthy subjects. Furthermore, gene variant studies identified novel genetic changes in these candidate genes, suggesting potential clinical significance in CML. CONCLUSIONS: This study highlights RPL9, RPL34, RPL36A, RPL39, CCDC170, LDB1, and SBF1 as potential targets in CML. Additionally, it underscores the importance of investigating these genes and their variants in larger cohort studies to assess their clinical significance in CML patients.

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Background: The neutrophil-to-lymphocyte ratio (NLR) and immunoglobulin A (IgA) level are commonly used as biomarkers for inflammation. Patients with type 2 diabetes (T2D) may experience an imbalance of tear film and inflammation, which can result in dry eye disease (DED). This study aimed to assess the levels of IgA and explore its correlation with the NLR as potential inflammatory biomarkers for dry eye disease in patients with T2D. Methods: A retrospective study was conducted at the cornea clinic and diabetes centre of King Abdulaziz Medical City (Jeddah, Saudi Arabia). The study included patients with DED and the number of available T2D-DED patients determined the sample size. Neutrophil, lymphocyte, IgA and CRP (C-reactive protein) laboratory values were obtained from medical records and correlational analyses were performed. Results: The study included 85 patients with an average age of 54 ± 14.4 years for the DED group (n=32) and 62 ± 13.9 years for the T2D-DED group (n=53). The age difference between the two groups was statistically significant (p 0.0001). The NLR values of the T2D-DED and DED groups were 3.203 ± 0.66 and 2.406 ± 0.46, respectively, with no significant difference (p<0.285). Similarly, there were no significant differences in neutrophil and lymphocyte values between the two groups. The IgA levels showed no significant variation between T2D-DED and DED groups (p<0.364). Spearman's correlation analysis in the DED group showed a significant negative correlation between IgA and lymphocyte (p=0.011; r= - 0.471) values and significant positive correlations between IgA and neutrophil (p=0.014; r=0.309) and NLR (p=0.052; r= - 0.283) values. In the T2D-DED group, a significant correlation was found between IgA and CRP values (p=0.032; r=0.33). Conclusion: Although diabetic patients may exhibit higher levels of NLR and IgA that correlate with disease severity, our study did not find significant differences in NLR and IgA values between the two groups. These findings may guide future research and enhance understanding of the disease's underlying mechanisms.

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Lactoferrin (LF) is a multifunctional antimicrobial, anti-inflammatory, and antioxidant protein that occurs naturally in mammals, most notably in exocrine gland tissues and fluids, such as in the eye. Nitrosative stress can promote changes to tyrosine and other amino acid residues of the protein, which also reduces the activity of LF. l-ergothioneine (ET) is a potent anti-inflammatory antioxidant present in the eye and other tissues through nutrition or supplementation and that may play a role in the prevention or treatment of a variety of diseases. Here we investigated the ability of ET to reduce 3-nitrotyrosine (NTyr) formation using two separate substrates, with the goal of determining whether ET can protect the antibacterial function of LF and other proteins when exposed separately to peroxynitrite and tetranitromethane as nitrating reagents. Native human LF was used as a simple protein substrate, and lamb corneal lysate was chosen as one example of mammalian tissue with a more complex mixture of proteins and other biomolecules. Nitration was monitored by absorbance and fluorescence spectroscopy as well as sandwich (nitrated LF) and direct NTyr (corneal lysate) enzyme-linked immunosorbent assays (ELISAs). We found that pretreatment with ET reduced chemical modification of both native LF and corneal lysate samples and loss of antibacterial LF function due to exposure to the nitrating reagents. These initial results suggest that ET, raised to sufficiently elevated levels, could be tailored as a therapeutic agent to reduce effects of nitrosative stress on LF and in turn sustain the protein activity.

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BACKGROUND: Patients with Diabetes mellitus (DM) are at risk of developing dry eye disease (DED). We investigated routine laboratory parameters in patients with type 2 DM (T2D) and T2D-DED to identify potential inflammatory markers. METHODS: A retrospective study of 241 randomly selected patients (30 DED non-diabetic, 120 T2D, and 91 with T2D-DED). The neutrophil-to-lymphocyte ratios (NLR), CRP-to-albumin ratios (CAR), and the glycosylated haemoglobin A1c (HbA1c) results were correlated between groups. RESULTS: The NLR and HbA1c were significantly higher in the T2D-DED group (p≤0.001 and 0.0001, respectively) when compared with T2D and DED non-diabetic groups. CAR was insignificantly high in the three groups (p=0.192). A positive correlation was identified between CAR and NLR in T2D-DED patients (p= 0.008). CONCLUSION: In T2D-DED patients, NLR was significantly high and positively correlate with CAR. These results predicate diabetes with dry eye complications, and biomarker-mediated inflammation may have important roles in DED pathogenesis.

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BACKGROUND: There are limited data regarding potential triggering factors of pulmonary embolism (PE) in coronavirus disease 2019 (COVID-19) patients and its outcomes in comparison with non-infected PE patients. We aimed to identify the contribution of COVID-19 among patients diagnosed with PE and compare risk factors, laboratory results, and outcomes between COVID-19 PE patients and non-COVID-19 PE patients. METHODS: This was a retrospective study of all PE patients between March 2020 and December 2020. The patients were segmented into two groups based on a COVID-19 nasopharyngeal swab result. Statistical analysis was used to determine the differences in risk factors, laboratory values, and outcomes. RESULTS: A total of 58 patients were included. Females comprised 44.8% of the total sample. Overall, 16 patients (27.6%) were COVID-19 positive. Being non-Saudi was observed more in PE COVID-19 patients compared with non-COVID-19 patients (43.7% vs 4.8%, P = 0.001). Intensive care unit (ICU) admission occurred in 50% of COVID-19 PE patients. CONCLUSION: COVID-19 was associated with 27.6% of the PEs in our hospital. Being male or a foreign resident was observed to be associated with COVID-19 PE. Further studies with larger sample sizes are needed, but these results may help the medical community regarding the increased risk of PE among COVID-19 patients and provide evidence of some potentially predictive factors that can be used to identify COVID-19 in high-risk patients.

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Background and Objectives: In both pandemic and non-pandemic situations, nonpharmaceutical public health measures may offer easy, low-cost, and effective means of reducing the spread and impact of acute respiratory infections. It is unknown whether such measures would be acceptable to the Saudi community beyond the current pandemic. Materials and Methods: A validated survey was used to test community acceptance of the measures. Respondents were asked which infection control practices they planned to maintain and which they believed should be policies for the community as a whole after the COVID-19 pandemic has subsided. Results: The survey was completed by 2057 people (95% completion rate), 1486 (72%) of whom were female, 259 (12.5%) of whom were current smokers, and 72 (3.5%) of whom had chronic lung disease. The most prevalent age groups were 18−30 years (933; 45.4%) and 31−40 years (483; 23.5%), with 641 individuals over 40 years old. Of the responses, 93% indicated that they would continue washing their hands more often; 92% wanted both clinicians and patients to wear masks in hospitals; 86% would continue avoiding smoking in indoor and outdoor areas; 73% would continue wearing a face covering on public transportation; 70% indicated that they would continue wearing a face covering in indoor public places. Regarding the respiratory virus infection control measures, 85% (11/13) received significant support (≥70% acceptability level) for continuation as policies in the future. Wearing face coverings outdoors and social distancing outdoors received little support (45% and 66%, respectively). Of the respiratory virus infection control measures, 54% received less support from current smokers than non-smokers (acceptability level < 70%). People with chronic respiratory disease supported 77% of the measures being regarded as policies in the future. Conclusion: The Saudi community supports nonpharmacological respiratory infection control measures that reduce the likelihood of infection. Public health campaigns should target smokers to increase awareness of the importance of these measures in lowering infections. Based on the findings of this study, nonpharmacological treatments should be presented and included in future recommendations for both the public and patients diagnosed with chronic respiratory diseases.

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BACKGROUND: Animal models of blood cancer are important tools to study these malignancies and also screen for novel therapeutic agents. Evidence from past research on the carcinogenic properties of 7,12-dimethylbenz[a]-anthracene (DMBA) was provided by a handful of studies. However, recent literature on DMBA carcinogenic activity and the underlying mechanisms is scarce. OBJECTIVE: The aim of this study was to develop a chemical model of leukemia using DMBA. Male Wistar rats (6 weeks old) were administered 1.5 mg of DMBA dissolved in sesame oil in biweekly doses using oral intragastric intubation. MATERIALS AND METHODS: Frequent complete blood counts and blood smear morphology assessment were used to assess the development of leukemia, while gross pathology and histopathology staining were used to evaluate malignancy development. RESULTS: The results showed that only 4% of rats developed acute lymphocytic leukemia. Interestingly, 36% of the rats developed tumors (parotid tumors [24%] and fibrosarcomas [12%]). CONCLUSION: These results suggest the pleiotropic potential of DMBA in the induction of multiple types of malignancies, including leukemia. This could be used as a model to validate therapeutic targets for leukemia and other induced malignancies.

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BACKGROUND: The coronavirus disease-19 (COVID-19) pandemic caused a major impact on blood donation process and supply globally. A lockdown management procedure was launched nationally in Saudi Arabia to manage this global health crisis. The main aim of this study was to determine the effect of COVID-19 lockdown on blood donation services and supply in different regions of Saudi Arabia. Study Design and Methods. A retrospective cross-sectional study was conducted in the blood bank centers of 5 major cities including Riyadh, Jeddah, Dammam, Hail, and Jizan in Saudi Arabia. Demographic and blood characteristics were retrieved from the first 6 months of 2019 (January-June) and compared to the same period of 2020. RESULTS: Our findings showed variation in the characteristics of blood donation and supply among the centers surveyed, as some of these centers were adversely affected, while others showed an increase in the availability of blood products during the pandemic. For example, Jeddah's center was significantly affected by COVID-19 lockdown whereas Hail's center showed a significant increase in the analyzed characteristics of blood donation services in 2020 compared to 2019. Overall, there was no major difference among the surveyed centers between 2020 and 2019, and this might be due to the effective management of blood supply and transfusion. Discussion. Although blood supply and transfusion practice was slightly affected at various degree among the surveyed centers, the whole process did not show a significant effect on the overall outcome. This is in fact due to the proper preparedness, management of blood requirements and supplies, and efficient response of the surveyed centers in Saudi Arabia.

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This study evaluated if the hepatic protective effect of Isoliquiritigenin (ISL) against doxorubicin (DOX)-treated rats involves upregulating sirtuin-1 (SIRT1) signaling. Adult male was divides into 5 groups (n = 6 rats/each) as control (vehicle), ISL (25 mg/kg), DOX (15 mg/kg), DOX + ISL, and DOX + ISL + EX-527 (a SIRT1 inhibitor, 5 mg/kg). ISL and EX-527 were administered 10 days before and after the single treatment of DOX. Also, cultured AML-12 hepatocytes (5 ×104) were treated with 10 µM of ISL for 24 h with or without DOX-treatments (10 µM) and in the presence or absence of EX-527 (5 µM). ISL prevented hepatocyte damage and decreased serum levels of hepatic transaminases, hepatic levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and hepatic mRNA levels of Bax and caspases-3,8, and 9. In the liver of the control and DOX-treated rats, ISL reduced levels of malondialdehyde (MDA) but increased hepatic levels of glutathione (GSH), superoxide dismutase (SOD), and catalase, as well as mRNA levels of Bcl2. In vitro, ISL stimulated cell survival and lowered levels of ROS but increased GSH levels. In vivo and in vitro, in the livers of control and DOX-treated animals, ISL significantly increased the nuclear activity and mRNA levels of SIRT1, enhanced the nuclear levels of Nrf2, and reduced nuclear levels of NF-κB p65. In conclusion, ISL alleviates DOX-induced hepatocyte toxicity by stimulating the Nrf2/antioxidants axis and concomitant suppression of NF-κB, mainly by upregulating/activating SIRT1.

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Adansonia digitata exhibits numerous beneficial effects. In the current study, we investigated the anti-cancer effects of four different extracts of A. digitata (polar and non-polar extracts of fruit powder and fibers) on the proliferation of human colon cancer (HCT116), human breast cancer (MCF-7), and human ovarian cancer (OVCAR-3 and OVCAR-4) cell lines. RNA sequencing revealed the influence of the effective A. digitata fraction on the gene expression profiles of responsive cells. The results indicated that only the polar extract of the A. digitata fibers exhibited anti-proliferative activities against HCT116 and MCF-7 cells, but not ovarian cancer cells. Moreover, the polar extract of the fibers resulted in the modulation of the expression of multiple genes in HCT116 and MCF-7 cells. We propose that casein kinase 2 alpha 3 (CSNK2A3) is a novel casein kinase 2 (CSNK2) isoform in HCT116 cells and report, for the first time, the potential involvement of FYVE, RhoGEF, and PH domain-containing 3 (FGD3) in colon cancer. Together, these findings provide evidence supporting the anti-cancer potential of the polar extract of A. digitata fibers in this experimental model of breast and colon cancers.

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PURPOSE: A proportion of 10 to 30% of patients treated by chemoradiotherapy followed by total mesorectal excision surgery for a locally advanced rectal cancer can achieve a complete pathological response. We aimed to identify predictive factors associated with complete pathological response or no response and to assess the impact of each response on survival rates. PATIENTS AND METHODS: Patients treated with long course chemoradiotherapy for locally advanced and/or node positive rectal cancer from 2010 to 2016 were retrospectively reviewed. Statistical analysis was carried out to determine predictors of tumor regression and treatment outcomes. RESULTS: Records were available on 70 patients. In the univariate analysis, clinical factors associated with complete tumor response were tumor mobility in digital rectal examination (P=0.047), a limited parietal invasion (P=0.001), clinically negative lymph node (P<0.001) and a circumferential extent greater than 50% (P=0.001). On the other hand, a T4 classification and an endoscopic tumor size greater than 6cm were associated with no response to treatment (P=0.049 and P=0.017 respectively). On multivariate analysis, T2 clinical classification and N0 statement before treatment were independent predictive factors of pathologic complete response (P<0.001 and P=0.001) and a delayed surgery after 12 weeks was associated with no response to treatment (P=0.001). CONCLUSION: The identification of predictive factors of histological response may help clinicians to predict the prognosis and to propose organ preservation for good responders.

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INTRODUCTION: The understanding of blood group phenotypes in Saudi Arabia is limited to the ABO and Rh blood groups. Data for the other major blood group phenotypes in different populations have been widely studied and used as a reference for identifying antigen-negative blood in hospital blood banks. Such information is crucial for facilitating the challenging task of providing antigen-negative blood for patients with multiple antibodies. OBJECTIVE: The aim of this study was to determine the frequency of the major blood group phenotypes in the Eastern region of Saudi Arabia and compare them to phenotypes in other populations. METHODS: A total of 100 volunteer Saudi donors were included in this study. Red blood cells from the donors were subjected to antigen typing of the major blood group systems (Rh, Kell, Kidd, Duffy, MNS, Lewis, Lutheran, and P) using the gel microtube technique. RESULTS: From the Rh blood group system, the e antigen was found in 97% of donors, followed by c at 86%. The Cellano (k) antigen of the Kell system was found in all donors, whereas the Kell (K) antigen was only found in 8 % of donors. The K+k- phenotype was not detected in our study. Unexpectedly, for the Duffy blood group system, the null phenotype Fy(a-b-) was found in 61% of donors. In the MNS blood group system, M+N-S+s+ was the most common phenotype at 24%. CONCLUSION: The frequency of blood group phenotypes in the Eastern region of Saudi Arabia differs from that in other populations because of the diverse ethnic backgrounds of those living in that region. The findings of this study can be used to establish a local donor registry to help provide antigen-negative blood for patients with unexpected antibodies or to create an in-house antibody identification panel to add to the commercial panel that would be useful for confirming antibody identification results.

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Lactoferrin (LF) is a multifunctional protein that plays important physiological roles as one of the most concentrated proteins in many human and other mammalian fluids and tissues. In particular, LF provides antibacterial properties to human milk, saliva, and tear fluid. LF also protects against stress-induced lipid peroxidation at inflammation sites through its iron-binding ability. Previous studies have shown that LF can be efficiently nitrated via biologically relevant mediators such as peroxynitrite (ONOO- ), which are also present at high intracellular concentrations during inflammation and nitrosative stress. Here, we examine changes in antibacterial properties and structure of LF following ONOO- treatment. The reaction induces nitration of tyrosine and tryptophan residues, which are commonly used as biomarker molecules for several diseases. Treatment with ONOO- at a 10/1 M ratio of ONOO- to tyrosine inhibited all antibacterial activity exhibited by native LF. Secondary structural changes in LF were assessed using circular dichroism spectroscopy. Nitration products with and without the addition of Fe3+ show significant reduction in alpha-helical properties, suggesting partial protein unfolding. Iron-binding capacity of LF was also reduced after treatment with ONOO- , suggesting a decreased ability of LF to protect against cellular damage. LC-MS/MS spectrometry was used to identify LF peptide fragments nitrated by ONOO- , including tyrosine residue Y92 located in the iron-binding region. These results suggest that posttranslational modification of LF by ONOO- could be an important pathway to exacerbate infection, for example, in inflamed tissues and to reduce the ability of LF to act as an immune responder and decrease oxidative damage.

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