Non-injected illicit drug use and infectious disease risk of donor tissue: a single institution retrospective review.

This study assessed the relationship of non-injected illicit drug use and infectious disease seropositivity for human immunodeficiency virus (HIV-1), hepatitis B virus (HBV), hepatitis C virus (HCV), and Syphilis. In a retrospective review of 986 donor charts recovered from 2009 to 2011 at a single tissue bank, the absence of reported non-injected illicit drug use corresponded with seropositivity in 6.61 %, of recovered donors while reported illicit drug use in the medical and social history corresponded with seropositivity in 11.25 %, representing a 70 % increased risk. There was no significant difference noted for overall seropositivity rates between types on noninjected illicit drugs, although donors that used cocaine had a higher incidence of HIV, while marijuana use was associated with a higher rate of HBV, HCV, and syphilis positivity. Toxicology screening results were not an accurate predictor of seropositivity (PPV = 3.77 %; NPV = 91.56 %). Further, the degree of relationship between the donor and the next of kin had no bearing on the veracity of actual drug use when comparing the response of the medical-social history and the toxicology screen.

Regulation of onco and tumor suppressor MiRNAs by mTORC1 inhibitor PRP-1 in human chondrosarcoma.

Metastatic chondrosarcoma of mesenchymal origin is the second most common bone malignancy and does not respond either to chemotherapy or radiation; therefore, the search for new therapies is relevant and urgent. This study aimed to reveal the comparative analysis of miRNAs and their targets in human JJ012 chondrosarcoma cell line between control and experimental samples, treated with mTORC1 inhibitor, cytostatic antiproliferative proline-rich polypeptide (PRP-1). Examination of tumor-specific microRNA expression profiles has revealed widespread deregulation of these molecules in diverse cancers. It was reported that microRNAs can function as novel biomarkers for disease diagnostics and therapy, as well as a novel class of oncogenes and tumor suppressor genes. mTORC 1 inhibitor PRP-1 caused significant upregulation of tumor suppressors, such as miR20a, miR125b, and miR192; and downregulation of onco miRNAs, miR509-3p, miR589, miR490-3p, miR 550 in human chondrosarcoma JJ012 cell line.

Pathogens in FRI - Do bugs matter? - An analysis of FRI studies to assess your enemy.

Fracture-related infection (FRI) is a devasting complication for both patients and their treating Orthopaedic surgeon that can lead to loss of limb function or even amputation. The unique and unpredictable features of FRI make its diagnosis and treatment a significant challenge. It has substantial morbidity and financial implications for patients, their families and healthcare providers. In this article, we perform an in-depth and comprehensive review of FRI through recent and seminal literature to highlight evolving definitions, diagnostic and treatment approaches, focusing on common pathogens such as Staphylococcus aureus, polymicrobial infections and multi-drug-resistant organisms (MDRO). Furthermore, multiple resistance mechanisms and adaptations for microbial survival are discussed, as well as modern evidence-based medical and surgical advancements in treatment strategies in combating FRI.

Fracture-related infection in revision proximal femoral intramedullary nails.

BACKGROUND: The proximal femoral nail is a commonly used fixation device for extra-capsular neck of femur fractures at our UK NHS Trust. Fracture-related infection (FRI) is a catastrophic complication that can be associated with internal fixation. FRI is often diagnosed late, and causes significant impact on the patient and healthcare system, leading to extended hospital stays, reduced quality of life, high healthcare costs and increased mortality and morbidity. AIM: This study aims to evaluate whether failed proximal femoral nails treated at a major trauma centre in the United Kingdom are undergoing routine intraoperative microbiology sampling, as outlined by the FRI Consensus Group in 2020, and also to establish how often fracture-related infection is present in failed proximal femoral nails. METHOD: Electronic patient record systems were reviewed over a 4-year period between 2018-2022 to identify patients who had a proximal femoral nailing, and those who required revision surgery. From this cohort, we then identified whether sampling had taken place during revision surgery, and the number of samples taken. RESULTS: 1041 proximal femoral nails were performed at our trust during the 4-year period. 60 of these implants failed, with 52 of these undergoing revision surgery at our hospital.  Only 56% cases had intra-operative samples taken for microbiology testing, with an average of 9 samples sent per case. Intra-operative sampling confirmed infection in 25% of cases with samples sent.  Of the cases requiring ≥ 3 operations, 75% of cases had confirmed infection. DISCUSSION: The data shows that more can be done to ensure earlier diagnosis of fracture-related infection in failed proximal femoral nails. We should have a high suspicion of FRI in this cohort of patients. This study highlights the importance of a standardised protocol to ensure routine intra-operative sampling during proximal femoral nail revision surgery.

Consensus on managing open ankle fractures in the frail patient.

Aims: Ankle fractures are common injuries and the third most common fragility fracture. In all, 40% of ankle fractures in the frail are open and represent a complex clinical scenario, with morbidity and mortality rates similar to hip fracture patients. They have a higher risk of complications, such as wound infections, malunion, hospital-acquired infections, pressure sores, veno-thromboembolic events, and significant sarcopaenia from prolonged bed rest. Methods: A modified Delphi method was used and a group of experts with a vested interest in best practice were invited from the British Foot and Ankle Society (BOFAS), British Orthopaedic Association (BOA), Orthopaedic Trauma Society (OTS), British Association of Plastic & Reconstructive Surgeons (BAPRAS), British Geriatric Society (BGS), and the British Limb Reconstruction Society (BLRS). Results: In the first stage, there were 36 respondents to the survey, with over 70% stating their unit treats more than 20 such cases per year. There was a 50:50 split regarding if the timing of surgery should be within 36 hours, as per the hip fracture guidelines, or 72 hours, as per the open fracture guidelines. Overall, 75% would attempt primary wound closure and 25% would utilize a local flap. There was no orthopaedic agreement on fixation, and 75% would permit weightbearing immediately. In the second stage, performed at the BLRS meeting, experts discussed the survey results and agreed upon a consensus for the management of open elderly ankle fractures. Conclusion: A mutually agreed consensus from the expert panel was reached to enable the best practice for the management of patients with frailty with an open ankle fracture: 1) all units managing lower limb fragility fractures should do so through a cohorted multidisciplinary pathway. This pathway should follow the standards laid down in the "care of the older or frail orthopaedic trauma patient" British Orthopaedic Association Standards for Trauma and Orthopaedics (BOAST) guideline. These patients have low bone density, and we should recommend full falls and bone health assessment; 2) all open lower limb fragility fractures should be treated in a single stage within 24 hours of injury if possible; 3) all patients with fragility fractures of the lower limb should be considered for mobilisation on the day following surgery; 4) all patients with lower limb open fragility fractures should be considered for tissue sparing, with judicious debridement as a default; 5) all patients with open lower limb fragility fractures should be managed by a consultant plastic surgeon with primary closure wherever possible; and 6) the method of fixation must allow for immediate unrestricted weightbearing.

Patient reported outcomes after definitive open tibial fracture management.

AIMS: Open tibial fractures are often life-changing injuries and patient outcomes remain poor despite the introduction of national management guidelines. The longer-term impact to the patient can be considerable but this is often overlooked in the literature. This study aims to establish the functional, physical, and psychosocial impact of sustaining an open tibial fracture. METHODS: We reviewed 69 consecutive Gustilo-Anderson grade IIIB and IIIC open tibial fractures that presented to our Major Trauma Centre (MTC) between September 2012 and April 2018. Each participant was interviewed and sent patient-reported outcome questionnaires, a minimum of 12 months following injury. Our primary outcome was the Lower Extremity Functional Scale (LEFS). Secondary outcomes included the Short-Form 36 Healthy Survey (SF-36), Sickness Impact Profile 128 (SIP) and return to occupation. Subgroups were analysed according to age, Injury Severity Score (ISS) and limb amputation. RESULTS: The mean follow up was 43 months. 96% were grade IIIB and 4% grade IIIC. The response rate for our study was 72%. The mean LEFS was 42 (IQR 21.5-58.5). All total and sub-domain scores within both the SF-36 and SIP questionnaires were reduced when compared to normative population data. Only 48% of patients returned to full time employment. Subgroup analysis revealed significantly reduced LEFS, SIP and SF-36 subdomain scores for those with a presenting ISS >14 and those undergoing limb amputation. CONCLUSION: Patients are at significant risk of longer-term functional, physical and psychosocial harm after suffering an open tibial fracture. Those sustaining major polytrauma or amputation demonstrated to have the greatest risk of poor outcome. Early identification of these individuals likely to suffer most from their injury would help direct appropriate resources to those with greatest need at the earliest opportunity.

Frequency Of Hyperuricemia In Subjects With Unstable Angina/Myocardial Infarction And Their Prognosis.

BACKGROUND: Inhibition of nitric oxide synthesis and stimulation of smooth muscle proliferation by increased serum levels of uric acid play an important role in accelerated atherogenesis in the vessels of patients with hyperuricemia. The objective of the study was to determine the frequency of hyperuricemia in patients with acute coronary syndrome and their in-hospital outcomes. METHODS: This cross-sectional study was conducted in the cardiology department of Ayub Teaching Hospital, Abbottabad from 1st September, 2018 to 28th February, 2019. A total of 199 patients diagnosed with acute coronary syndrome (ACS) were enrolled in this study using non-probability consecutive sampling. Diagnosis of ACS was made on history, electrocardiogram (ECG) findings and on the presence of elevated cardiac biomarkers. Serum uric acid was checked within 24 hours of presentation and patients were grouped into hyperuricemic and normouricemic groups according to uric acid levels. Next in-hospital outcomes were compared between the two groups by comparing the presence or absence of complications. The data was collected on a structured proforma and was analyzed statistically by using SPSS version 16. RESULTS: Out of 199 patients, 146 (73.37%) were male and 53 (26.63%) were female. The mean age of the study participants was 57.99 ± 6.07 years with a range of 48-68 years. Hyperuricemia was diagnosed in 50 (25.13%) study participants. Among complications, 15 patients (7.94%) had cardiogenic shock, 27 (13.57%) had heart failure, 10 (5.03%) had cardiac arrhythmias, 16 (8.04%) had conduction defects and hyperuricemia was diagnosed in 50 (25.13%) patients. Cardiogenic shock was more common in patients with hyperuricemia (p < 0.05). CONCLUSIONS: Hyperuricemia is associated with a number of significant adverse outcomes for patients with an acute coronary event. Regular screening / monitoring of serum uric acid level in general population can prevent the direct and indirect morbidity associated with hyperuricemia.

Outcomes following the delayed management of open tibial fractures.

AIMS: National guidelines set standards for the definitive management of open fractures within 72 h. This study aims to investigate our outcomes where this timeline was unachievable for most cases due to a split-site orthoplastic service. PATIENTS & METHODS: 116 consecutive Gustilo-Anderson grade IIIB & IIIC open tibial fractures presenting to our major trauma centre (MTC) between September 2012 and April 2018 were reviewed. The mean follow up was 46 months (17 to 88). 110 (95%) were grade IIIB and 6 (5%) grade IIIC. The most common injury mechanism included road traffic accidents (59%) and falls (28%). Primary outcomes were recorded according to; timing of initial debridement and definitive cover, rates of superficial and deep infection, non-union and amputation. Subgroups were statistically analysed according to time to initial debridement, definitive soft-tissue cover and injury severity score (ISS). RESULTS: The mean time to initial debridement was 11.3 h (2.9 to 38.9) and definitive soft-tissue cover 9.9 days (0 to 37). We recorded rates of: superficial infection; 42 cases (36%), deep infection; 14 cases (12%) and non-union requiring revision; 19 cases (16%). There were 20 amputations (17%) with 9 (8.6%) performed early and 11 (9.5%) delayed. Subgroup analysis showed higher rates of superficial infection (50%, p = 0.002) and amputation (26.6%, p = 0.01) for those debrided <12 h. A greater presenting ISS related to a delay to definitive cover >7 days (p = 0.05). Primary outcomes trended worse for those covered >7 days but did not reach significance. CONCLUSION: Major trauma patients are particularly vulnerable to poor outcomes resulting from the delay in definitive management of open fractures. MTC's need resources and a co-located orthoplastic service to achieve national standards and better outcomes. Current guidelines do not advise for the management of patients where a delay in definitive surgery is anticipated.

Etiology and Types of Seizures in Patients Presenting to a Tertiary Care Hospital in Karachi: A Cross-Sectional Study.

Introduction Epilepsy is a burdensome disorder for affected individuals and community. There is limited data available on the epidemiological aspects of seizures in Pakistan and further research is necessary. We aimed to fill this gap by studying this information in epilepsy patients presenting to our neurology department. The purpose of this study is to evaluate the causes and types of seizures among the target population. Method This is a cross-sectional study conducted at the Department of Neurology, Dr. Ruth K.M. Pfau Civil Hospital Karachi. In this study we evaluated the causes and types of seizures among patients presenting to our department during the two-year study duration (January 2018-December 2019). Informed consent was taken. Detailed history was taken including features of seizure episodes, age at first seizure, family history and comorbid conditions. Relevant investigations were carried out. The data was compiled to deduce the relevant information using SPSS v20.0. T-test and Chi-square were used for analyzing the data. Results A total of 996 patients presented during the study duration. Primary seizures were found in 58% cases while secondary seizures were found in 42% cases. This distribution was more equal in children with 49.6% primary seizures and 50.4% secondary seizures; the gap widened in adults with 64.3% primary seizures and 35.7% secondary seizures. The most common cause of secondary seizures was neonatal encephalopathy which was present in 18.7% patients, followed by traumatic head injury in 18.2% patients. Central nervous system (CNS) infection was the cause in 17.9% patients, cerebral tumors in 14.1% patients, stroke in 11.5%, metabolic encephalopathy in 7.4%, febrile seizures in 6.5% and CNS malformations in 5.7% patients. The top three causes in children were neonatal encephalopathy (28.3%), CNS infections (19.3%) and febrile seizures (12.7%). Adults with secondary seizures were diagnosed most often with head trauma (25.2%), cerebral tumors (19.9%) and stroke (18.4%) as causative factors. The most common type of seizures was generalized onset tonic-clonic seizures which was found in 73.0% patients followed by focal to bilateral tonic-clonic seizures in 8.9% patients. Other types of seizures included focal aware seizures in 5.0%, mixed seizure types in 4.2%, focal impaired awareness seizures in 3.1%, absence seizures in 2.7%, myoclonic seizures in 2.0% and atonic seizures in 1.0% patients. Seizures in children were mostly generalized onset tonic-clonic seizures (75.4%), mixed seizure types (5.7%) and focal to bilateral tonic-clonic seizures (5.2%). In adults the three most common types corresponded to the overall result: generalized onset tonic-clonic seizures (71.2%), focal to bilateral tonic-clonic seizures (11.6%) and focal aware seizures (6.6%). Conclusion We found that the most common cause of seizures overall in our study population was primary seizures, though primary and secondary seizures were more evenly present in children. Among secondary causes neonatal encephalopathy stood out as the most common cause in children; head trauma was the predominant cause in adults. Most common type of seizures overall and in adults was generalized onset tonic-clonic seizures, followed by focal to bilateral tonic-clonic and focal aware seizure types. Pediatric patients presented most often with generalized onset tonic-clonic seizures, followed by mixed seizure types and focal to bilateral tonic-clonic seizures.

Regenerative medicine in lower limb reconstruction.

Bone is a highly specialized connective tissue and has a rare quality as one of the few tissues that can repair without a scar to regain pre-injury structure and function. Despite the excellent healing capacity of bone, tumor, infection, trauma and surgery can lead to significant bone loss requiring skeletal augmentation. Bone loss in the lower limb poses a complex clinical problem, requiring reconstructive techniques to restore form and function. In the past, amputation may have been the only option; however, there is now an array of reconstructive possibilities and cellular therapies available to salvage a limb. In this review, we will evaluate current applications of bone tissue engineering techniques in limb reconstruction and identify potential strategies for future work.

Toll like receptors TLR1/2, TLR6 and MUC5B as binding interaction partners with cytostatic proline rich polypeptide 1 in human chondrosarcoma.

Metastatic chondrosarcoma is a bone malignancy not responsive to conventional therapies; new approaches and therapies are urgently needed. We have previously reported that mTORC1 inhibitor, antitumorigenic cytostatic proline rich polypeptide 1 (PRP-1), galarmin caused a significant upregulation of tumor suppressors including TET1/2 and SOCS3 (known to be involved in inflammatory processes), downregulation of oncoproteins and embryonic stem cell marker miR-302C and its targets Nanog, c-Myc and Bmi-1 in human chondrosarcoma. To understand better the mechanism of PRP-1 action it was very important to identify the receptor it binds to. Nuclear pathway receptor and GPCR assays indicated that PRP-1 receptors are not G protein coupled, neither do they belong to family of nuclear or orphan receptors. In the present study, we have demonstrated that PRP-1 binding interacting partners belong to innate immunity pattern recognition toll like receptors TLR1/2 and TLR6 and gel forming secreted mucin MUC5B. MUC5B was identified as PRP-1 receptor in human chondrosarcoma JJ012 cell line using Ligand-receptor capture technology. Toll like receptors TLR1/2 and TLR6 were identified as binding interaction partners with PRP-1 by western blot analysis in human chondrosarcoma JJ012 cell line lysates. Immunocytochemistry experiments confirmed the finding and indicated the localization of PRP-1 receptors in the tumor nucleus predominantly. TLR1/2, TLR6 and MUC5B were downregulated in human chondrosarcoma and upregulated in dose-response manner upon PRP-1 treatment. Experimental data indicated that in this cellular context the mentioned receptors had tumor suppressive function.

Effect of cytostatic proline rich polypeptide-1 on tumor suppressors of inflammation pathway signaling in chondrosarcoma.

Cytokines produced in the tumour microenvironment exert an important role in cancer pathogenesis and in the inhibition of disease progression. Cancer of the cartilage is termed metastatic chondrosarcoma; however, the signaling events resulting in mesenchymal cell transformation to sarcoma have yet to be fully elucidated. The present study aimed to characterize the cytokine expression profile in the human JJ012 chondrosarcoma cell line, as well as the effect of cytostatic proline-rich polypeptide-1 (PRP-1). Western blot experiments demonstrated that the levels of suppressor of cytokine signaling 3 (SOCS3) were upregulated in chondrocytes compared with chondrosarcoma cells. Addition of PRP-1 restored the expression of the tumor suppressors, SOCS3 and ten-eleven-translocation methylcytosine dioxygenase 1 and 2 (TET1/2), in a dose-responsive manner. It is known that methylation of histone H3K9 was eliminated from the promoters of the inflammation-associated genes. PRP-1 inhibited H3K9 demethylase activity with an IC50 (concentration required to give half-maximal inhibition) value of 3.72 µg/ml in the chondrosarcoma cell line. Data obtained from ELISA experiments indicated that the expression of interleukin-6 (IL-6) in chondrosarcoma cells was 86-fold lower compared with that in C28 chondrocytes. In the present study, a 53-fold downregulation of IL-6 expression in co-culture of chondrosarcoma cells and C28 chondrocytes was identified as well. Downregulation of IL-6 expression has been documented in numerous other tumor types, although the reasons for this have not been fully established. In chondrosarcoma, IL-6 manifests itself as an anti-inflammatory agent and, possibly, as an anti-tumorigenic factor. To explore protein-DNA interactions leading to such differences, a gel-shift chemiluminescent assay was performed. Gel shifts were observed for chondrosarcoma and chondrocytes in the lanes that contained nuclear cell extract and oligo-IL-6 DNA. Notably, the DNA-protein complexes in C28 chondrocytes were markedly larger compared with those in chondrosarcoma cells. The mechanisms that underpin such differences, and characterization of the interacting proteins, remain to be fully elucidated.

Seasonal diagnosis of echocardiographically demonstrated endocarditis.

BACKGROUND: Many cardiac and infectious diseases have a seasonal incidence. It is not known whether similar variations exist for endocarditis. METHODS: As echocardiography plays a key role in diagnosing endocarditis, patients referred for echocardiography with suspected endocarditis from 1993 through 2001 were identified. The modified Duke criteria were used in establishing endocarditis. The echocardiography date was arbitrarily used to determine season: fall/winter (October to March) and spring/summer (April to September). RESULTS: For the 1,279 patients referred for echocardiography to rule out endocarditis, there was no seasonal difference between the total number of referred fall/winter and spring/summer patients (645 patients vs 634 patients, respectively). However, endocarditis was found in 41 fall/winter patients (6.4%) and 19 spring/summer patients (3.0%) patients (odds ratio, 2.20; 95% confidence interval, 1.26 to 3.83; p = 0.004). This seasonal disparity was present in 7 of the 9 years studied. No clinical factors could account for this seasonal disparity. CONCLUSIONS: As with many other cardiac diseases, a significant fall/winter predominance for endocarditis was found.

Restoration of desmosomal junction protein expression and inhibition of H3K9-specific histone demethylase activity by cytostatic proline-rich polypeptide-1 leads to suppression of tumorigenic potential in human chondrosarcoma cells.

Disruption of cell-cell junctions and the concomitant loss of polarity, downregulation of tumor-suppressive adherens junctions and desmosomes represent hallmark phenotypes for several different cancer cells. Moreover, a variety of evidence supports the argument that these two common phenotypes of cancer cells directly contribute to tumorigenesis. In this study, we aimed to determine the status of intercellular junction proteins expression in JJ012 human malignant chondrosarcoma cells and investigate the effect of the antitumorigenic cytokine, proline-rich polypeptide-1 (PRP-1) on their expression. The cell junction pathway array data indicated downregulation of desmosomal proteins, such as desmoglein (1,428-fold), desmoplakin (620-fold) and plakoglobin (442-fold). The tight junction proteins claudin 11 and E-cadherin were also downregulated (399- and 52-fold, respectively). Among the upregulated proteins were the characteristic for tumors gap junction ß-5 protein (connexin 31.1) and the pro-inflammatory pathway protein intercellular adhesion molecule (upregulated 129- and 43-fold, respectively). We demonstrated that PRP-1 restored the expression of the abovementioned downregulated in chondrosarcoma desmosomal proteins. PRP-1 inhibited H3K9-specific histone demethylase activity in chondrosarcoma cells in a dose-dependent manner (0.5 µg/ml PRP, 63%; 1 µg/ml PRP, 74%; and 10 µg/ml PRP, 91% inhibition). Members of the H3K9 family were shown to transcriptionally repress tumor suppressor genes and contribute to cancer progression. Our experimental data indicated that PRP-1 restores tumor suppressor desmosomal protein expression in JJ012 human chondrosarcoma cells and inhibits H3K9 demethylase activity, contributing to the suppression of tumorigenic potential in chondrosarcoma cells.

Epigenetic regulation of embryonic stem cell marker miR302C in human chondrosarcoma as determinant of antiproliferative activity of proline-rich polypeptide 1.

Metastatic chondrosarcoma of mesenchymal origin is the second most common bone malignancy and does not respond either to chemotherapy or radiation; therefore, the search for new therapies is relevant and urgent. We described recently that tumor growth inhibiting cytostatic proline-rich polypeptide 1, (PRP-1) significantly upregulated tumor suppressor miRNAs, downregulated onco-miRNAs in human chondrosarcoma JJ012 cell line, compared to chondrocytes culture. In this study we hypothesized the existence and regulation of a functional marker in cancer stem cells, correlated to peptides antiproliferative activity. Experimental results indicated that among significantly downregulated miRNA after PRP-1treatment was miRNAs 302c*. This miRNA is a part of the cluster miR302­367, which is stemness regulator in human embryonic stem cells and in certain tumors, but is not expressed in adult hMSCs and normal tissues. PRP-1 had strong inhibitory effect on viability of chondrosarcoma and multilineage induced multipotent adult cells (embryonic primitive cell type). Unlike chondrosarcoma, in glioblastoma, PRP-1 does not have any inhibitory activity on cell proliferation, because in glioblastoma miR-302-367 cluster plays an opposite role, its expression is sufficient to suppress the stemness inducing properties. The observed correlation between the antiproliferative activity of PRP-1 and its action on downregulation of miR302c explains the peptides opposite effects on the upregulation of proliferation of adult mesenchymal stem cells, and the inhibition of the proliferation of human bone giant-cell tumor stromal cells, reported earlier. PRP-1 substantially downregulated the miR302c targets, the stemness markers Nanog, c-Myc and polycomb protein Bmi-1. miR302c expression is induced by JMJD2-mediated H3K9me2 demethylase activity in its promoter region. JMJD2 was reported to be a positive regulator for Nanog. Our experimental results proved that PRP-1 strongly inhibited H3K9 activity comprised of a pool of JMJD1 and JMJD2. We conclude that inhibition of H3K9 activity by PRP-1 leads to downregulation of miR302c and its targets, defining the PRP-1 antiproliferative role.

Proteomic and phospho-proteomic profile of human platelets in basal, resting state: insights into integrin signaling.

During atherogenesis and vascular inflammation quiescent platelets are activated to increase the surface expression and ligand affinity of the integrin alphaIIbbeta3 via inside-out signaling. Diverse signals such as thrombin, ADP and epinephrine transduce signals through their respective GPCRs to activate protein kinases that ultimately lead to the phosphorylation of the cytoplasmic tail of the integrin alphaIIbbeta3 and augment its function. The signaling pathways that transmit signals from the GPCR to the cytosolic domain of the integrin are not well defined. In an effort to better understand these pathways, we employed a combination of proteomic profiling and computational analyses of isolated human platelets. We analyzed ten independent human samples and identified a total of 1507 unique proteins in platelets. This is the most comprehensive platelet proteome assembled to date and includes 190 membrane-associated and 262 phosphorylated proteins, which were identified via independent proteomic and phospho-proteomic profiling. We used this proteomic dataset to create a platelet protein-protein interaction (PPI) network and applied novel contextual information about the phosphorylation step to introduce limited directionality in the PPI graph. This newly developed contextual PPI network computationally recapitulated an integrin signaling pathway. Most importantly, our approach not only provided insights into the mechanism of integrin alphaIIbbeta3 activation in resting platelets but also provides an improved model for analysis and discovery of PPI dynamics and signaling pathways in the future.