Prevalence and Diagnosis of PCOS Using Electronic Health Records: A Scoping Review and a Database Analysis.

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder affecting women of reproductive age. It increases the risk of type 2 diabetes, cardiovascular disease, endometrial cancer, infertility, gestational diabetes, preeclampsia, and preterm birth. Accurately identifying predictors of these health risks is crucial. Electronic health records (EHRs) offer an affordable approach, however, the validity and reliability of EHRs for PCOS diagnosis are unclear. A scoping review of the literature on the prevalence and reliability of the diagnosis of PCOS using EHRs was performed. An analysis of the feasibility of obtaining diagnostic variables from a PCOS patient database was also carried out. Eight studies met the criteria. The prevalence of PCOS ranged from 0.27% to 5.8%. Reliability varied, with one study reporting a sensitivity of 50% and a specificity of 29%. Another study found a 74.4% agreement between international classification of disease (ICD) codes and clinical criteria. The database analysis found only 13.7%, 8%, and 7.5% of women had all the necessary variables for an objective diagnosis of PCOS using the Rotterdam, National Institutes of Health (NIH), and Androgen Excess and PCOS Society (AEPCOS) criteria, respectively. Using EHRs results in an underestimation of PCOS prevalence compared to other diagnostic criteria, and many women identified may not meet the complete diagnostic criteria. These findings have implications for future research studies on PCOS prevalence and related health risks.

Evaluating Transperineal Prostate Biopsies Performed by a New Operator: A Prospective Clinical Audit at Dorset County Hospital.

Introduction The transperineal (TP) approach for prostate biopsy offers advantages such as a low risk of infection, the ability to target lesions in difficult locations, and a rapid acquisition of proficiency. This prospective clinical audit aims to evaluate the outcomes and patient experiences of TP prostate biopsies performed by a new operator to determine the feasibility of adopting the TP biopsy as the primary method for prostate evaluations. Methods The study included all patients who underwent a TP prostate biopsy from August 1 to September 30, 2022, at Dorset County Hospital National Health Service Foundation Trust. The operator, a member of the urology team, had recently begun performing these biopsies independently after completing a four-month supervised training program and receiving approval from two consulting trainers. The biopsy technique was evaluated based on diagnostic yield and patient experience, comparing pre-procedure imaging results with histology reports and analyzing patient-completed questionnaires. Results Among the 42 patients, the cancer detection rate was 79%. The highest core positivity rate was 100% in two patients (5%), with 90% in 11 patients (26%). Of the patients, 57% showed complete agreement between magnetic resonance imaging findings and histology. A questionnaire assessing patient experience received a 64% response rate. The most common pain score reported was 2 (on a scale of 0-10), noted in 25% of patients. Most reported mild lower urinary tract symptoms (88%) and mild hematuria (85%). Of the patients, 44% rated their overall satisfaction as 10 (on a scale of 0-10), and no urinary tract infections were reported. Conclusion The findings support the adoption of TP biopsy as the primary method for prostate biopsies due to its short learning curve, high diagnostic yield, and favorable patient satisfaction. Training for new operators should be encouraged to achieve this goal.

Haemophilus influenzae Bacteremia and Pneumonia: A Case Report.

This study reports a case of respiratory failure and pneumonia attributed to infection from a confirmed case of Haemophilus influenzae in a patient with past medical history of interstitial lung disease following a COVID-19 infection. An 88-year-old man with significant past medical history of interstitial lung disease (ILD) and self-catheterization due to benign prostatic hyperplasia (BPH) presented to the ED with shortness of breath and cough. Examination revealed reduced respiratory effort and scattered rhonchi throughout the lung fields. Urine cultures were positive for extended spectrum beta-lactamase (ESBL) Escherichia coli. In addition, blood cultures and chest X-ray findings confirmed a case of H. influenzae bacteremia and pneumonia. The following case highlights the unusual finding of invasive H. influenzae disease and corresponds with the data provided by the Active Bacterial Core surveillance supported by the Centers for Disease Control and Prevention (CDC).

Inflicting Significant Losses in Slaughtered Animals: Exposing the Hidden Effects of Parasitic Infections.

We started a campaign in the heart of Faisalabad, Punjab, Pakistan, to expose the hidden threats of parasitic illnesses in ruminants and the severe financial consequences associated with them. Our in-depth investigations focused on the prevalence, impact, and astounding financial losses brought on by organ contamination in slaughtered animals. Of the 384 slaughtered ruminants examined for gastrointestinal parasites, a prevalence of 44.79% was recorded. It is interesting to note that we found no conclusive association between parasitic infection and the various ruminant species under study (p > 0.05). However, goats (52.0%) had the highest numerical prevalence of parasitic infection, followed by cattle (46.1%), buffalo (46.0%), and sheep (34.7%) in that order. A significant finding (p < 0.05) showed that the majority of animals had light parasitism (46.5%), as opposed to those with moderate (30.2%) or severe loads (23.2%). Our research revealed substantial (p < 0.05) relationships between ruminant age, sex, and parasitic infection prevalence. In comparison to females (56.4%) and adults (48.1%), males (36.1%) and young (36.9%) ruminants showed considerably decreased infection rates (p < 0.05). On the other hand, we discovered a non-significant (p > 0.05) association between the months and the prevalence of parasitic infection. As a result of the condemnation of contaminated organs such as the rumen, lungs, and liver, an estimated financial loss of PKR 133,731,400 (USD = 466,939.2) was incurred. The yearly economic losses caused by liver condemnation were much greater than those caused by rumen and lung condemnation (p < 0.05). Our research not only reported a significantly higher abundance but also economic threats of the parasitic diseases among the slaughtered animals in Faisalabad, Punjab, Pakistan. Our findings highlighted the critical need for preventive and therapeutic interventions for parasitic infections in animals, in order to mitigate the economic losses through strengthened animal health.

Polypharmacy, Gender Disparities, and Ethnic and Racial Predispositions in Long QT Syndrome: An In-Depth Review.

Long QT syndrome (LQTS) is a complex disorder of cardiac electrophysiology. It is characterized by delayed myocardial polarization leading to QT prolongation and alterations on the ST segment and T wave visible on electrocardiogram (ECG). Syncope is a common manifestation, and torsade de pointes (TdP) can lead to sudden cardiac death. Three major LQTS genes (KCI31, KCNH2, and SCN5) lead to most of the cases of LQTS. Lifestyle modifications, beta blockers, and implantable cardioverter defibrillator (ICD) placement are the main treatments for LQTS. Polypharmacy, including QT-prolonging drugs, has been shown to worsen LQTS. The impact on potassium channels and the human ether-a-go-go-related gene (hERG) is the mechanism behind the QT interval prolongation caused by these medications. There is an increased incidence of LQTS among African-American men and women as compared to Caucasians. Women with LQTS tend to have a higher mortality rate from the condition, especially during menstruation and shortly after giving birth. Genetic testing is reserved to those patientswho exhibit either a strong clinical index of suspicion or experience persistent QT prolongation despite their lack of symptoms. Knowing the genetics, racial, and gender discrepancies can help improve patient management and a better comprehension on each case. Proper understanding of how ion channels function and their interaction with medications will lead to a better comprehension and to develop effective forms to treat those patients.

A Functional Genomics Review of Non-Small-Cell Lung Cancer in Never Smokers.

There is currently a dearth of information regarding lung cancer in never smokers (LCINS). Additionally, there is a difference in somatic mutations, tumour mutational burden, and chromosomal aberrations between smokers and never smokers (NS), insinuating a different disease entity in LCINS. A better understanding of actionable driver alterations prevalent in LCINS and the genomic landscape will contribute to identifying new molecular targets of relevance for NS that will drastically improve outcomes. Differences in treatment outcomes between NS and smokers, as well as sexes, with NSCLC suggest unique tumour characteristics. Epidermal growth factor receptor (EGFR) tyrosine kinase mutations and echinoderm microtubule-associated protein-like 4 anaplastic lymphoma kinase (EML4-ALK) gene rearrangements are more common in NS and have been associated with chemotherapy resistance. Moreover, NS are less likely to benefit from immune mediators including PD-L1. Unravelling the genomic and epigenomic underpinnings of LCINS will aid in the development of not only novel targeted therapies but also more refined approaches. This review encompasses driver genes and pathways involved in the pathogenesis of LCINS and a deeper exploration of the genomic landscape and tumour microenvironment. We highlight the dire need to define the genetic and environmental aspects entailing the development of lung cancer in NS.

Combination of inhibitors for two glycolytic enzymes portrays high synergistic efficacy against Cryptosporidium parvum.

Cryptosporidium is an intracellular protozoan parasite that causes serious enteric disease in humans and in a wide range of animals worldwide. Despite its high prevalence, no effective therapeutic drugs are available against life-threatening cryptosporidiosis in at-risk populations including malnourished children, immunocompromised patients, and neonatal calves. Thus, new efficacious drugs are urgently needed to treat all susceptible populations with cryptosporidiosis. Unlike other apicomplexans, Cryptosporidium parvum lacks the tricarboxylic acid cycle and the oxidative phosphorylation steps, making it solely dependent on glycolysis for metabolic energy production. We have previously reported that individual inhibitors of two unique glycolytic enzymes, the plant-like pyruvate kinase (CpPyK) and the bacterial-type lactate dehydrogenase (CpLDH), are effective against C. parvum, both in vitro and in vivo. Herein, we have derived combinations of CpPyK and CpLDH inhibitors with strong synergistic effects against the growth and survival of C. parvum, both in vitro and in an infection mouse model. In infected immunocompromised mice, compound combinations of NSC303244 + NSC158011 and NSC252172 + NSC158011 depicted enhanced efficacy against C. parvum reproduction and ameliorated intestinal lesions of cryptosporidiosis at doses fourfold lower than the total effective doses of individual compounds. Importantly, unlike individual compounds, NSC303244 + NSC158011 combination was effective in clearing the infection completely without relapse in immunocompromised mice. Collectively, our study has unveiled compound combinations that simultaneously block two essential catalytic steps for metabolic energy production in C. parvum to achieve improved efficacy against the parasite. These combinations are, therefore, lead compounds for the development of a new generation of efficacious anti-cryptosporidial drugs.

Association of Parsonage-Turner syndrome with COVID-19 infection and vaccination: a systematic review.

OBJECTIVES: The exact etiology of Parsonage-Turner syndrome is unknown, but it is known to be preceded by infection, vaccination, or surgical intervention. In this review, we describe associations of Parsonage-Turner syndrome with COVID-19 infection and vaccination. METHODS: A systematic literature search was conducted using PubMed/MEDLINE, ScienceDirect, and Google Scholar. Microsoft Excel was used for data extraction and statistical analysis. The quality of case reports and case series was assessed using the Joanna Briggs Institute Critical Appraisal Tool. RESULTS: We selected 44 case reports and 10 case series, including 68 patients (32 post-vaccination and 36 with post-COVID-19 infection Parsonage-Turner syndrome). Middle-aged males were predominantly affected in both groups. The most frequently administered vaccine was Comirnaty (Pfizer) (53%). The mean latency was 11.7 days in the post-vaccination group and 20.3 days in the post-infection group. The most affected nerves in both groups were the axillary, suprascapular, and musculocutaneous nerves; and 78.1% and 38.9% of patients showed partial amelioration of their symptoms in the post-vaccination and post-infection groups, respectively. CONCLUSION: Post-vaccination Parsonage-Turner syndrome presents earlier than post-infection disease. Pain and sensorimotor deficits of the upper limb are common in both situations. Complete or partial recovery occurs in most cases.

Stem cells in degenerative lumbar spine disease: a review and focus on utility in Low- and Middle-Income Countries.

Stem cell therapy is a common adjunct in regenerative medicine and has recently seen greater adoption in spinal surgery. Arthrodesis is typically achieved with iliac-crest bone grafts with several adverse events, leading to the development of alternative biomaterials. One such biomaterial is stem cells, which may be equal in terms of effectiveness but with significantly fewer complications. Low- and Middle-Income Countries (LMICs) have seen slow adoption of stem cell therapy due to resource constraints but may benefit the most from these techniques. We conducted a comprehensive review of literature in the PUBMED, Scopus, and Cochrane Library databases on the use of stem cells and stem cell-based biomaterials in spinal surgery. Our review showed promising results, from a variety of methods including augmentation of existing scaffold with mesenchymal stem cells or concentrated bone marrow aspirate. With minimal complications, stem cell augmentation can be a good alternative to existing biomaterial use for spinal fusion and repair.

Effect of Wide-Spectrum Monochromatic Lights on Growth, Phytochemistry, Nutraceuticals, and Antioxidant Potential of In Vitro Callus Cultures of Moringa oleifera.

Moringa oleifera, also called miracle tree, is a pharmaceutically important plant with a multitude of nutritional, medicinal, and therapeutic attributes. In the current study, an in-vitro-based elicitation approach was used to enhance the commercially viable bioactive compounds in an in vitro callus culture of M. oleifera. The callus culture was established and exposed to different monochromatic lights to assess the potentially interactive effects on biomass productions, biosynthesis of pharmaceutically valuable secondary metabolites, and antioxidant activity. Optimum biomass production (16.7 g/L dry weight), total phenolic contents (TPC: 18.03 mg/g), and flavonoid contents (TFC: 15.02 mg/g) were recorded in callus cultures placed under continuous white light (24 h), and of other light treatments. The highest antioxidant activity, i.e., ABTS (550.69 TEAC µM) and FRAP (365.37 TEAC µM), were also noted under white light (24 h). The analysis of phytochemicals confirmed the significant impact of white light exposures on the enhanced biosynthesis of plant secondary metabolites. The enhanced levels of secondary metabolites, i.e., kaempferol (1016.04 µg/g DW), neochlorogenic acid (998.38 µg/g DW), quercetin (959.92 µg/g DW), and minor compounds including luteolin, apigenin, and p-coumaric acid were observed as being highest in continuous white light (24 h with respect to the control (photoperiod). Similarly, blue light enhanced the chlorogenic acid accumulation. This study shows that differential spectral lights demonstrate a good approach for the enhancement of nutraceuticals along with novel pharmacologically important metabolites and antioxidants in the in vitro callus culture of M. oleifera.

Acute coronary syndrome in patients with cancer.

INTRODUCTION: Improvement in cancer survival has led to an increased focus on cardiovascular disease as the other major determinant of survivorship. As a result, there has been an increasing interest in managing cardiovascular disease during and post cancer treatment. AREAS COVERED: This article reviews the current literature on the pathogenesis, risk factors, presentation, treatment and clinical outcomes of acute coronary syndrome (ACS) in patients with cancer. EXPERT OPINION: There is growing evidence that both medical therapy and invasive management of ACS improve outcomes in patients with cancer. Appropriate patient selection, risk stratification and tailored therapy represents the cornerstone of management in these patients.

ExAID: A multimodal explanation framework for computer-aided diagnosis of skin lesions.

BACKGROUND AND OBJECTIVES: One principal impediment in the successful deployment of Artificial Intelligence (AI) based Computer-Aided Diagnosis (CAD) systems in everyday clinical workflows is their lack of transparent decision-making. Although commonly used eXplainable AI (XAI) methods provide insights into these largely opaque algorithms, such explanations are usually convoluted and not readily comprehensible. The explanation of decisions regarding the malignancy of skin lesions from dermoscopic images demands particular clarity, as the underlying medical problem definition is ambiguous in itself. This work presents ExAID (Explainable AI for Dermatology), a novel XAI framework for biomedical image analysis that provides multi-modal concept-based explanations, consisting of easy-to-understand textual explanations and visual maps, to justify the predictions. METHODS: Our framework relies on Concept Activation Vectors to map human-understandable concepts to those learned by an arbitrary Deep Learning (DL) based algorithm, and Concept Localisation Maps to highlight those concepts in the input space. This identification of relevant concepts is then used to construct fine-grained textual explanations supplemented by concept-wise location information to provide comprehensive and coherent multi-modal explanations. All decision-related information is presented in a diagnostic interface for use in clinical routines. Moreover, the framework includes an educational mode providing dataset-level explanation statistics as well as tools for data and model exploration to aid medical research and education processes. RESULTS: Through rigorous quantitative and qualitative evaluation of our framework on a range of publicly available dermoscopic image datasets, we show the utility of multi-modal explanations for CAD-assisted scenarios even in case of wrong disease predictions. We demonstrate that concept detectors for the explanation of pre-trained networks reach accuracies of up to 81.46%, which is comparable to supervised networks trained end-to-end. CONCLUSIONS: We present a new end-to-end framework for the multi-modal explanation of DL-based biomedical image analysis in Melanoma classification and evaluate its utility on an array of datasets. Since perspicuous explanation is one of the cornerstones of any CAD system, we believe that ExAID will accelerate the transition from AI research to practice by providing dermatologists and researchers with an effective tool that they can both understand and trust. ExAID can also serve as the basis for similar applications in other biomedical fields.

Differential induction of antioxidant and anti-inflammatory phytochemicals in agitated micro-shoot cultures of Ajuga integrifolia Buch. Ham. ex D.Don with biotic elicitors.

Ajuga integrifolia Buch. Ham. ex D.Don, a member of Lamiaceae family is pharmaceutically an active perennial herb widely spread in China, Afghanistan and Pakistan Himalayan region. The application of biotic elicitors is a promising approach to cover limitations of in vitro cell technology and challenges faced by pharmaceuticals industry for bulk up production. The current study involved the induction of agitated micro-shoot cultures with the aim to investigate the growth-promoting as well as phytochemicals enhancement role of yeast extract (YE) and pectin (PE). The results showed that both elicitors induced a considerable physiological response. Biomass accumulation was observed maximum (DW: 18.3 g/L) against PE (10 mg/L) compared to YE and control. Eleven secondary phytocompounds were quantified using high-performance liquid chromatography. PE (50 mg/L) was found to be effective in elicitation of rosmarinic acid (680.20 µg/g), chlorogenic acid (294.12 µg/g), apigenin (579.61 µg/g) and quercetin (596.89 µg/g). However, maximum caffeic acid (359.52 µg/g) and luteolin (546.12 µg/g accumulation was noted in PE (1 mg/L) treatment. Harpagide, aucubin, harpagoside and 8-O-acetyl-harpagoside production was suppressed by both elicitors except for YE (100 mg/L). Catalpol accumulation in micro-shoot cultures was also downregulated except in response to YE (50 and 100 mg/L). Antioxidant activity and anti-inflammatory activity remained higher under PE (50 mg/L) and YE (100 mg/L) respectively. Therefore, results suggested that Ajuga integrifolia micro-shoot cultures treated with yeast extract and pectin might be an efficient bio-factory to produce commercially potent specific secondary metabolites.

Association study of interleukin-1 receptor associated kinase 1 rs3027898 A/C gene polymorphism and preeclampsia in Pakistani population.

OBJECTIVES: To find the association between interleukin-1 receptor-associated kinase 1 rs3027898 gene polymorphism and preeclampsia. METHODS: The case-control study was conducted from October, 2018 to September, 2019 at the Railway General Hospital and the Department of Biochemistry, Islamic International Medical College, Rawalpindi, Pakistan, and comprised patients diagnosed with preeclampsia and healthy controls. The interleukin receptor-associated kinase-1 polymorphism was determined using multiplex tetra primer amplification refractory mutation system polymerase chain reaction. Outcomes were determined in terms of association of interleukin receptor-associated kinase-1 with preeclampsia. Data was analysed using SPSS 22. RESULTS: Of the 160 subjects, 80(50% were cases with a mean age of 30±5.3 years and 80(50%) were controls with a mean age of 27±3.7 years. AC genotype was seen in 45(56.25%) cases and 30(37.5%) controls, AA genotype in 25(31.25%) cases and 30(37.5%) controls, while CC genotype was seen in 10(12.5%) cases and 20(25%) controls (p>0.05). CONCLUSIONS: There was no significant association of interleukin receptor-associated kinase-1 genotypes with preeclampsia.

Hydatigera taeniaeformis in urban rats (Rattus rattus) in Faisalabad, Pakistan.

Hydatigera taeniaeformis formerly referred to as Taenia taeniaeformis is a cestode of cats (definitive hosts) and rodents (intermediate hosts). The prevalence of the metacestode larval stage has been reported in rodents in many parts of the world even though the genetic polymorphisms or intraspecies variation is still understudied. Here, we report a prevalence of 22.09% (38/172) from an urban rodent population in Pakistan and a nucleotide diversity (cox1) of 0.00463 among the population. Infection was higher in male (27.85%) and adult (32.29%) rats than female and sub-adult/young rats. Interestingly, The median-joining network and phylogenetic construction comprising isolates from China, Japan, Kenya, Laos, Malaysia, Senegal, the United Arab Emirates, and countries in Europe demonstrated that Pakistani H. taeniaeformis are closer to Asian and African population than those of European origin. The results of the study will add-in preliminary data for H. taeniaeformis and will also contribute to understand the global molecular epidemiology and population structure of H. taeniaeformis.

Glutathione S-Transferase Theta 1 / Mu 1 Null Genotype and Risk of Development of Actinic Keratosis in Pakistani Population.

OBJECTIVE: To assess the frequency and association of Glutathione S-Transferase Theta 1 and Glutathione S-Transferase Mu 1 null genotypes in development of actinic keratosis (AK) in a group of Pakistani population. STUDY DESIGN: Case-control analytical study. PLACE AND DURATION OF STUDY: Department of Biochemistry, Islamic International Medical College, Rawalpindi in collaboration with Department of Dermatology, Railway Hospital and Rural Health Center, District Health Office, Rawalpindi from September 2018 to September 2019.  Methodology: A total of 86 participants were included in this study with 27 biopsy proven cases of AK and 59 matched controls. Blood samples were collected after obtaining written informed consent; and DNA was extracted by Chelex™ method. Multiplex PCR (M-PCR) was done to find respective allelic frequencies of GSTM1 and GSTT1 genes in both cases and controls.  Results: Mean age of participants in cases and controls was 62.93 ±10.29 years and was 61.42 ±9.96 years, respectively. There were 18 males (66.7%) and 9 females (33.3%); and 43 males (72.9%) and 16 females (27.1%) in cases and controls, respectively. There was a significant association of GSTT1 null genotype with AK (OR: 2.72, 95% CI: 1.05-7.05, p = 0.037). There was a positive correlation between GSTT1 null genotype and AK (r = 0.225, p = 0.037). CONCLUSION: GSTT1 null genotype has a significant association for AK development in the studied Pakistani population. Key Words: Actinic keratosis, Glutathione S-Transferase Mu 1, Glutathione S-Transferase Theta 1, Polymerase chain reaction, Squamous cell carcinoma.

Correction to: Two-stage framework for optic disc localization and glaucoma classification in retinal fundus images using deep learning.

Following publication of the original article.

Two-stage framework for optic disc localization and glaucoma classification in retinal fundus images using deep learning.

BACKGROUND: With the advancement of powerful image processing and machine learning techniques, Computer Aided Diagnosis has become ever more prevalent in all fields of medicine including ophthalmology. These methods continue to provide reliable and standardized large scale screening of various image modalities to assist clinicians in identifying diseases. Since optic disc is the most important part of retinal fundus image for glaucoma detection, this paper proposes a two-stage framework that first detects and localizes optic disc and then classifies it into healthy or glaucomatous. METHODS: The first stage is based on Regions with Convolutional Neural Network (RCNN) and is responsible for localizing and extracting optic disc from a retinal fundus image while the second stage uses Deep Convolutional Neural Network to classify the extracted disc into healthy or glaucomatous. Unfortunately, none of the publicly available retinal fundus image datasets provides any bounding box ground truth required for disc localization. Therefore, in addition to the proposed solution, we also developed a rule-based semi-automatic ground truth generation method that provides necessary annotations for training RCNN based model for automated disc localization. RESULTS: The proposed method is evaluated on seven publicly available datasets for disc localization and on ORIGA dataset, which is the largest publicly available dataset with healthy and glaucoma labels, for glaucoma classification. The results of automatic localization mark new state-of-the-art on six datasets with accuracy reaching 100% on four of them. For glaucoma classification we achieved Area Under the Receiver Operating Characteristic Curve equal to 0.874 which is 2.7% relative improvement over the state-of-the-art results previously obtained for classification on ORIGA dataset. CONCLUSION: Once trained on carefully annotated data, Deep Learning based methods for optic disc detection and localization are not only robust, accurate and fully automated but also eliminates the need for dataset-dependent heuristic algorithms. Our empirical evaluation of glaucoma classification on ORIGA reveals that reporting only Area Under the Curve, for datasets with class imbalance and without pre-defined train and test splits, does not portray true picture of the classifier's performance and calls for additional performance metrics to substantiate the results.

A Single Controlled Exposure to Secondhand Smoke May Not Alter Thrombogenesis or Trigger Platelet Activation.

INTRODUCTION: Chronic secondhand smoke (SHS) exposure increases cardiovascular events, particularly acute thrombotic events. There are little human data on acute SHS exposure. The aim of this study was to determine whether a single controlled exposure of humans to SHS increased thrombogenesis. METHODS: After 6-8 hours fast, subjects (n = 50) were exposed to constant dose SHS (particulate level of 500 µg/m(3)) for 120 minutes in a temperature-regulated and ventilated, simulated bar environment. Blood was drawn before and immediately after SHS exposure for thromboelastography (TEG) and flow cytometry. Maximum clot strength (MA) was measured using TEG and platelet leukocyte aggregates (LPA) were measured as an index of platelet activation. Anti-CD 14 antibodies were used as leukocyte markers and anti-CD 41 antibodies as platelet markers for cytometry. Data were analyzed using students' t test for paired samples. RESULTS: There was no effect of acute exposure to SHS on platelet activation or thrombogenesis. Also, intra group (smokers [n = 19] and nonsmokers [n = 31]) comparisons of LPA and TEG parameters did not show changes with SHS exposure. CONCLUSIONS: While there are abundant data showing enhanced thrombogenesis and platelet activation following repeated exposure to SHS, our study suggests that a single exposure does not appear to significantly alter thrombin kinetics nor result in platelet activation. The effects of SHS on thrombogenesis might be nonlinear.