Three-dimensional genome architecture persists in a 52,000-year-old woolly mammoth skin sample.

Analyses of ancient DNA typically involve sequencing the surviving short oligonucleotides and aligning to genome assemblies from related, modern species. Here, we report that skin from a female woolly mammoth (†Mammuthus primigenius) that died 52,000 years ago retained its ancient genome architecture. We use PaleoHi-C to map chromatin contacts and assemble its genome, yielding 28 chromosome-length scaffolds. Chromosome territories, compartments, loops, Barr bodies, and inactive X chromosome (Xi) superdomains persist. The active and inactive genome compartments in mammoth skin more closely resemble Asian elephant skin than other elephant tissues. Our analyses uncover new biology. Differences in compartmentalization reveal genes whose transcription was potentially altered in mammoths vs. elephants. Mammoth Xi has a tetradic architecture, not bipartite like human and mouse. We hypothesize that, shortly after this mammoth's death, the sample spontaneously freeze-dried in the Siberian cold, leading to a glass transition that preserved subfossils of ancient chromosomes at nanometer scale.

Role of Machine Learning in Liquid Biopsy of Brain Tumours.

Liquid biopsy has multiple benefits and is used extensively in other fields of oncology, but its role in neuro-oncology has been limited so far. Multiple tumour-derived materials like circulating tumour cells (CTCs), tumour-educated platelets (TEPs), cell-free DNA (cfDNA), circulating tumour DNA (ctDNA), and miRNA are studied in CSF, blood (plasma, serum) or urine. Large and complex amounts of data from liquid biopsy can be simplified by machine learning using various algorithms. By using this technique, we can diagnose brain tumours and differentiate low versus highgrade glioma and true progression from pseudo-progression. The potential of liquid biopsy in brain tumours has not been extensively studied, but it has a bright future in the coming years. Here, we present a literature review on the role of machine learning in liquid biopsy of brain tumours.

Phacofragmentation of Posteriorly Dislocated Lens Fragments: Limbal versus Pars Plana Approach.

PURPOSE: To assess intra-operative complications and feasibility of removing crystalline lens fragments from the vitreous cavity through a limbal incision compared to a pars plana approach. DESIGN: Retrospective cohort study. SUBJECTS: 16 eyes underwent phacofragmentation via a limbal approach (Group A) and 9 eyes through a pars plana approach (Group B) at an academic center over a 10-year period. METHODS: We collected pre-operative, intra-operative, and post-operative data. We compared rates of intraoperative complications, including corneal wound burn, iris or capsular damage, retinal tears, and hemorrhage, and recorded post-operative BCVA and IOP measurements at the one-month post-operative appointment. We also compared rates of post-operative complications, including corneal edema, choroidal detachment, or retinal detachment. MAIN OUTCOME MEASURES: Primary outcomes of the study were the rates of intraoperative complications and the feasibility of crystalline lens removal with the limbal approach. We defined the latter outcome as the ability to complete lens removal without switching to the pars plana route. RESULTS: Mean BCVA for group A was 1.6, and for group B was 2.0 (p = .19). There was no significant difference between the two groups in the incidence of intraoperative complications, including corneal wound burn, iris damage, anterior capsular tear, iatrogenic retinal tear, or suprachoroidal hemorrhage (p > .99). There was no significant difference in the incidence of intra-operative vitreous hemorrhage (p = .36). Additionally, there was no significant difference in post-operative corneal edema (p = .27), choroidal detachment (p = .52), or retinal detachment (p > .99). The mean post-operative BCVA was 1.0 in group A and 1.0 in group B (p = .75). We completed all cases in group A using the limbal approach without switching to the pars plana route. CONCLUSION: Phacofragmentation through a limbal incision provides a feasible option for dropped nuclear fragment removal and is not associated with a higher risk of complications than the pars plana route.

Quality of life of pediatric patients with craniopharyngioma: A retrospective series from a low-middle-income country with more than 4 years follow-up.

Background: Craniopharyngiomas (CPs) are rare, low-grade tumors characterized by a range of debilitating symptoms. Most of the existing literature reports postoperative outcomes of the different treatment modalities of childhood CP. However, few studies have reported the impact of these different treatment methods on the quality of life (QoL) of survivors of childhood CP. Therefore, we aim to assess the correlation between different surgical modalities on the QoL of patients with childhood CP from a lower-middle-income country. Methods: Twenty-nine survivors who underwent treatment for CP were included in the study. The selected patients had either been managed with complete resection, debulking, or placement of an Ommaya reservoir. QoL was assessed by the pediatric quality of life (PedsQL) questionnaire. The effect of the different treatment modalities on the QoL was assessed. Results: Mean follow-up was 4.4 ± 2.19 years. The type of surgery was significantly related to the mean PedsQL scores for the total score as well as each of the individual domain scores (P < 0.001). Complete resection of the tumor resulted in the lowest mean (standard deviation) PedsQL total score of 56.6 ± 7.12 compared to the Ommaya reservoir with biopsy (83.3 ± 5.69) and debulking (93.8 ± 3.37) (P < 0.001). Conclusion: There was a significant effect of the type of surgical treatment on the QoL of the survivors of childhood CP. It is important to consider the long-term outcomes in addition to immediate postoperative outcomes when deciding on a treatment strategy while managing children with CP.

Effect of maternal obsessive-compulsive disorder (OCD) on feto-maternal outcomes: A systematic review and meta-analysis.

BACKGROUND: Mental health disorders in pregnant women have been related to unfavorable obstetric and neonatal outcomes. Obsessive-compulsive disorder (OCD) significantly distresses mothers and affects the maternal-infant bond. OBJECTIVES: The present meta-analysis and systematic review aimed to assess the association of maternal OCD with adverse feto-maternal outcomes. SEARCH STRATEGY: A systematic search was undertaken in the five databases-Cochrane, Embase, ProQuest, Web of Science, and PubMed-on September 5, 2023. SELECTION CRITERIA: Studies that included pregnant women with OCD in whom the feto-maternal outcomes were reported were included in the systematic review. DATA COLLECTION AND ANALYSIS: Two pass screening ("title-abstract screening" followed by "full-text review"), and data extraction by two authors independently using the Nested-Knowledge Auto living semi-automated systematic review platform was carried out. The decision for selected studies was reviewed by a third author. Of the 360 studies identified, eight were included for the meta-analysis. Meta-analysis was conducted using R software. MAIN RESULTS: Of the 24 maternal and neonatal adverse outcomes assessed, 11 were found to be associated with maternal OCD, notably pre-eclampsia (odds ratio [OR] 1.37, 95% confidence interval [CI] 1.19-1.57), antepartum hemorrhage or placental abruption (OR 1.32, 95% CI 1.13-1.54), postpartum hemporrhage (OR 1.19, 95% CI 1.08-1.31), cesarean section delivery (OR 1.32, 95% CI 1.23-1.41), emergency cesarean section (OR 1.22, 95% CI 1.15-1.30), preterm birth (OR 1.41, 95% CI 1.21-1.64), low birth weight (OR 1.41, 95% CI 1.28-1.54), low Apgar score at 5 min (OR 2.37, 95% CI 1.32-4.27), neonatal hypoglycemia (OR 1.37, 95% CI 1.23-1.53), neonatal respiratory distress (OR 1.77, 95% CI 1.44-2.16), and major congenital malformations (OR 1.37, 95% CI 1.08-1.74). CONCLUSION: OCD in pregnant women might be associated with multiple adverse feto-maternal outcomes.

Targeting self-care adherence for glycaemic control in multimorbid type 2 diabetes mellitus with depression using bupropion: a protocol for cross-over randomised controlled trial.

INTRODUCTION: Diabetes and depression are among the 10 biggest health burdens globally. They often coexist and exhibit a strong bidirectional relationship. Depression leads to decreased adherence to self-care activities. This impacts glycaemic control and worsens type 2 diabetes mellitus (T2D). Both conditions have a synergistic effect and lead to greater complications, hospitalisations, healthcare expenditure and a worse quality of life. There is no consensus on managing people with comorbid T2D and depression. Bupropion is an efficacious antidepressant with many properties suitable for T2D with depression, including a favourable metabolic profile, persistent weight loss and improvement in sexual dysfunction. We will assess the efficacy and safety of add-on bupropion compared with standard care in people with T2D and mild depression. This study can give valuable insights into managing the multimorbidity of T2D and depression. This can help mitigate the health, social and economic burden of both these diseases. RESEARCH DESIGN AND METHODS: This cross-over randomised controlled trial will recruit people with T2D (for 5 years or more) with mild depression. They will be randomised to add-on bupropion and standard care. After 3 months of treatment, there will be a washout period of 1 month (without add-on bupropion while standard treatment will continue). Following this, the two arms will be swapped. Participants will be assessed for glycosylated haemoglobin, adherence to diabetes self-care activities, lipid profile, urine albumin-to-creatinine ratio, autonomic function, sexual function, quality of life and adverse events. ETHICS AND DISSEMINATION: The Institutional Ethics Committee at All India Institute of Medical Sciences, Jodhpur has approved this study (AIIMS/IEC/2022/4172, 19 September 2022). We plan to disseminate the research findings via closed group discussions at the site of study, scientific conferences, peer-reviewed published manuscripts and social media. TRIAL REGISTRATION NUMBER: CTRI/2022/10/046411.

Prevalence of Acute on Chronic Liver Failure in Autoimmune Hepatitis, Treatment Response and Mortality Burden Assessment: A Region-Predominant Systematic Review and Meta-Analysis.

Acute-on-chronic liver failure (ACLF) is a global health problem. Little scientific evidence exists on its prevalence in autoimmune hepatitis. Treatment response and mortality outcomes have also been reported differently. The study was conducted to estimate the overall prevalence of ACLF among patients with autoimmune hepatitis (AIH) and determine the associated treatment response and mortality. We scrutinized wide literature in Scopus, PubMed, Embase, Web of Science, and Cochrane, and assessed published articles completely, studies performed and reported from around the globe, until December 07, 2023, according to the PROSPERO registered protocol (CRD42023412176). Studies (retrospective and prospective cohort study type) that stated the ACLF development among established AIH cases were considered. Features of the study, duration of follow-up, and numeric patient information were retrieved from the studies included. The research paper quality was checked for risk of bias. Random effect meta-analysis with metaregression and subsection scrutinies were performed with R. The main outcome was the collective prevalence of ACLF in the AIH patients, whereas treatment response and mortality in AIH-associated ACLF were secondary outcomes. Six studies were involved with confirmed diagnoses in 985 AIH patients for the data synthesis. The pooled prevalence of ACLF in the explored patients was 12% (95% CI: 8-17) ( P =0.01). Heterogeneity was found to be high in the present meta-analysis ( I2 =72%; P < 0.01). For the secondary endpoint analysis, the pooled prevalence of complete remission at 1-year follow-up was 71% (0.52; 0.85), and mortality from the ACLF-AIH patient population was 32% (95% CI: 18-50). Sensitivity analysis showed no influence on the overall estimations of the pooled prevalence of ACLF by omitting studies one by one. One in 10 AIH patients likely present with ACLF. The response to treatment is seen in two-thirds of patients, and mortality is high.

Oral health status of prisoners in India: A systematic review and meta-analysis.

AIMS: Given the high prevalence of oral health problems among prisoners, the goal of this systematic review is to provide a better knowledge of the scope of this problem. METHODS: Electronic searches of PubMed/MEDLINE, Embase, Scopus, and Google Scholar were performed. Studies that investigated inmates aged 18 or older with oral health problems were eligible. Variables reported in four or less studies were described narratively. Conversely, for variables reported in more than four studies, a meta-analysis was performed using random effect model. Furthermore, meta-regression and sensitivity analysis is also performed to evaluate moderator effect on outcome. Doi and LFT index is applied to assess publication bias. RESULTS: Out of 494 results, 12 studies were included. The pooled prevalence of caries among prisoners is 78.42% (59.48%-92.58%). On meta-regression, the prevalence of caries appears to be lower in studies with a higher male percentage; however, non-significant (p = .079) due to small sample size. Community periodontal index (CPI) scores revealed periodontal disease, with scores of 3 and 4. Moreover, a significant need for oral hygiene instruction, prosthesis, extraction, and tooth ache, periodontal disease, oral mucosal lesions, leucoplakia, attrition, abrasion, bruxism, and smoking behaviors were also reported. CONCLUSION: Poor oral health status in the incarcerated population highlights the urgent need for comprehensive oral health intervention in prisons.

Oral health status among the transgender population of India: A systematic review and meta-analysis.

BACKGROUND: The invisibility of the transgender population within official records, combined with other socio-economic factors, impacts oral health status among transgender people. Hence, our systematic review and meta-analysis aim to generate a pooled estimate of the oral health status of the transgender community in India. MATERIAL AND METHODS: A systematic search was performed across four databases. The studies included a quantitative research design conducted in India and involved self-identified transgender individuals. The pooled prevalence was determined at a 95% confidence interval (CI). Q-statistics and the I2 test were utilized to evaluate the source of heterogeneity. Leave-one-out analysis and Baujat plots were used to detect outliers within the studies. A Doi plot and LFK index were employed to assess the publication bias. RESULTS: A total of 12 studies comprising 1566 transgender participants were included. The pooled prevalence of toothbrush use among transgenders in India was found at 83% (95% CI: 0.73-0.91), smoking = 12% (CI: 0.03-0.26), smokeless tobacco = 53% (CI = 0.38-0.68), dental caries = 78% (CI: 67%-88%), calculus = 65% (CI: 0.4-0.86), and bleeding 18% (CI:0.08-0.32). CONCLUSION: Oral health disparities among Indian transgender individuals are evident in the low toothbrush usage, an elevated prevalence of tobacco use, and dental disorders such as calculus, cavities, and bleeding. Tailored dental health programs that include inclusive healthcare services and awareness are essential. PROSPERO REGISTRATION: CRD42023468872.

The Revival of Essay-Type Questions in Medical Education: Harnessing Artificial Intelligence and Machine Learning.

OBJECTIVE: To analyse and compare the assessment and grading of human-written and machine-written formative essays. STUDY DESIGN: Quasi-experimental, qualitative cross-sectional study. Place and Duration of the Study: Department of Science of Dental Materials, Hamdard College of Medicine & Dentistry, Hamdard University, Karachi, from February to April 2023. METHODOLOGY: Ten short formative essays of final-year dental students were manually assessed and graded. These essays were then graded using ChatGPT version 3.5. The chatbot responses and prompts were recorded and matched with manually graded essays. Qualitative analysis of the chatbot responses was then performed. RESULTS: Four different prompts were given to the artificial intelligence (AI) driven platform of ChatGPT to grade the summative essays. These were the chatbot's initial responses without grading, the chatbot's response to grading against criteria, the chatbot's response to criteria-wise grading, and the chatbot's response to questions for the difference in grading. Based on the results, four innovative ways of using AI and machine learning (ML) have been proposed for medical educators: Automated grading, content analysis, plagiarism detection, and formative assessment. ChatGPT provided a comprehensive report with feedback on writing skills, as opposed to manual grading of essays. CONCLUSION: The chatbot's responses were fascinating and thought-provoking. AI and ML technologies can potentially supplement human grading in the assessment of essays. Medical educators need to embrace AI and ML technology to enhance the standards and quality of medical education, particularly when assessing long and short essay-type questions. Further empirical research and evaluation are needed to confirm their effectiveness. KEY WORDS: Machine learning, Artificial intelligence, Essays, ChatGPT, Formative assessment.

RAPNO efforts in Brain Tumour Outcomes.

Assessing treatment efficacy for brain tumours has evolved since its inception with the introduction of MacDonald's criteria, which pioneered the utility of imaging to determine an objective and quantifiable response to treatment. This criterion failed to distinguish pseudo response or progression from progression and did not account for non-enhancing disease therefore; the response assessment in neuro-oncology (RANO) working group was established to account for these limitations. Since, its commencement it has worked to determine response assessment for multiple tumours. As paediatric tumours exhibit heterogeneous and variable-enhancing characteristics, the response assessment in paediatric neuro-oncology (RAPNO) working group was formed to create separate criteria. Six response criteria have been published to date, and the article summarizes them.

The role of 18F-FDG PET/CT in Neurolymphomatosis: A Comprehensive Imaging Approach.

Neurolymphomatosis (NL) is an uncommon and rare neurologic disorder characterised by extranodal lymphoma, where the tumour cells invade the cranial nerves, nerve plexus, nerve root, spinal nerve roots, trunk nerves or peripheral nerves. MRI is the modality of choice, but is often challenging in detection of early recurrence, assessing residual disease and response evaluation. 18FFDG PET/CT has superior diagnostic performance compared with body CT in the evaluation of NL. 18F-FDG PET-CT is helpful in evaluation of disease extent and potential to guide biopsy. 18F-FDG PETCT is a highly sensitive technique for early localisation of NL than MRI or CT alone. Besides diagnostic and prognostic value in NL, it might be very helpful in response assessment.

Exploring the role of Orexin-A neuropeptide in Parkinson's disease: A systematic review and meta-analysis.

BACKGROUND: Parkinson's disease (PD) is a progressive neurological condition that affects movement and coordination. Orexin-A (OXA) is an excitatory neuropeptide that is found throughout the central nervous system. There is growing interest in investigating the potential diagnostic and therapeutic utility of OXA in PD. To date, studies have reported a wide range of OXA concentrations in patients with PD. In this review, we discuss the current understanding of the dysregulation of OXA in PD and analyze its levels in the CSF. METHODS: We searched six databases (PubMed, Scopus, Web of Science, EMBASE, ProQuest, and EBSCOHost) and preprint servers using a predetermined search strategy through 4th March 4, 2023. The search keywords included "Parkinson's disease", "Orexin-A", "Hypocretin-1", "cerebrospinal fluid", and "CSF". Studies that reported OXA/Hypocretin-1 levels in the CSF of patients with PD were included. Two researchers independently reviewed the records and extracted data. FINDINGS: Eighteen studies involving 244 patients were analyzed. CSF Orexin-A concentrations were lower in patients with Parkinson's disease than in controls, with a mean difference of -59.21 (95 % CI: -89.10 to -29.32). The mean OXA levels were 281.52 (95 % CI: 226.65-336.40). CONCLUSION: Our analysis reveals lower concentrations of orexin-A in the cerebrospinal fluid of Parkinson's disease patients compared to controls, but within the normal range. These findings suggest a potential, but not significant, disruption in the orexinergic system associated with the disease.

Zavegepant for Acute Treatment of Migraine: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

OBJECTIVE: Evaluate the safety and efficacy of zavegepant (BHV-3500), a recently approved nasal spray containing a third-generation calcitonin gene-related peptide receptor antagonist, for treating acute migraine attacks. METHODS: A comprehensive search was conducted across various databases up to 06/26/2023 to identify relevant randomized clinical trials (RCTs) on zavegepant's efficacy and safety in treatment of acute migraine attacks. Primary outcome: freedom from pain at 2 hours postdose. Safety outcomes were evaluated based on adverse events (AEs), with zavegepant 10 mg and placebo groups compared for incidence of AEs. RESULTS: Two RCTs, involving 2061 participants (1014 receiving zavegepant and 1047 receiving placebo), were quantitatively analyzed. An additional trial was included for qualitative synthesis. Zavegepant 10 mg exhibited a significantly higher likelihood of achieving freedom from pain at 2 hours postdose compared with the placebo group (risk ratio [RR] 1.54, 95% confidence interval [CI] 1.28 to 1.84). It also showed superior relief from the most bothersome symptoms at 2 hours postdose compared with placebo (RR 1.26, 95% CI 1.13 to 1.42). However, the zavegepant 10 mg group experienced a higher incidence of AEs compared with placebo (RR 1.78, 95% CI 1.5 to 2.12), with dysgeusia being the most reported AE (RR 4.18, 95% CI 3.05 to 5.72). CONCLUSION: Zavegepant 10 mg is more effective than placebo in treating acute migraine attacks, providing compelling evidence of its efficacy in relieving migraine pain and most bothersome associated symptoms. Further trials are necessary to confirm its efficacy, tolerability, and safety in diverse clinic-based settings with varied patient populations.

Quality of Life of Children Treated for Split Cord Malformation.

OBJECTIVE: Split cord malformation (SCM), associated with neurologic deficits, necessitates surgical intervention for spinal cord detethering. Limited evidence exists regarding its impact on children's quality of life. Our study aims to evaluate the postoperative quality of life in children treated for SCM. METHODS: This retrospective cohort study examined records of patients with SCM operated on between July 1, 2012, and July 31, 2022, at a single center. Data, including Health Utility Index-3 (HUI-3) scores provided by guardians, was collected to assess quality of life. Clinical and neurologic outcomes were also analyzed. RESULTS: Twenty-five patients, predominantly female (68%), with a median age of 7 years, were included. Most presented with normal motor function (76%). The most common anatomic level of SCM was lumbar (12; 48%) followed by lumbosacral (5; 20%). A bony spur from the lamina was the most common cause of splitting the cord (64%). Over a median follow-up of 3.3 years, 64% of patients showed neurologic stability, 16% showed neurologic improvement, and 4% experienced deterioration. The mean HUI-3 score for 21 children was 0.93 ± 0.24. CONCLUSIONS: Surgical management of SCM showed favorable neurologic outcomes and a positive long-term quality of life, as shown by HUI-3 scores. Our findings emphasize the efficacy of surgical intervention in improving the lives of children with this condition.

Evolution of RANO in Assessing Brain Tumour Outcomes.

Assessing treatment response is extremely important in management of brain tumours. Response assessment in neuro-oncology (RANO) was introduced in 2008 for the purpose of making recommendations for it by addressing and countering the limitations in previously reported response criteriae. Subsequently, multiple RANO working groups have been formed to cater to different tumour types and to update their previous recommendations to counter the limitations in their criteria. Herein we have a summarized list of RANO criteria for adult brain tumours.

University teachers' perceptions of ICT-based teaching to construct knowledge for effective classroom interaction in the context of TPACK model.

The purpose of the research was to investigate university teachers' perceptions of information and communication technology (ICT) to enhance teaching and construct new knowledge. The objective was to determine how teachers at the University of the Gambia perceived the effectiveness of the TPACK (Technology, Pedagogy, and Content Knowledge) model in teaching through ICT and how different attributes of teachers affect their level of TPACK knowledge. This study used a questionnaire, adapted from the TPACK model, which was administered to 88 faculty selected purposively from the University of the Gambia to collect data on their level of awareness of ICT-based teaching. Descriptive analysis was first run to check the scores of all components of TPACK, then a correlational analysis was carried out to measure the relationship between the TPACK constructs. The data collected from these analyses were used to construct a structural equation model that showed the relationship between TPACK constructs as perceived by the faculty of the University of the Gambia. The results of this study showed that the individual construct (i.e., technology, pedagogy, and content) and the paired constructs (i.e. Technology and Pedagogy, Technology and Content, Pedagogy and Content knowledge) of TPACK are positively correlated with teachers' perceived TPACK, as well as the findings are consistent with the earlier claim that ICT-based instruction may not progress as quickly in education even when it is available and teachers are not knowledgeable about it. The results contribute to earlier research that aims to develop strategies for implementing ICT-based instruction in HEIs and offer advice to educators on how to create policies including TPACK components in their teaching and learning.

Prevalence of Frailty and Its Impact on Mortality and Hospitalization in Patients With Cirrhosis: A Systematic Review and Meta-analysis.

Background & aims: Frailty in patients with cirrhosis is associated with increased morbidity and mortality. In this study, we aimed to determine the prevalence of frailty and its impact on mortality and hospitalization in patients with cirrhosis. Methods: An elaborate search was undertaken in the databases "PubMed, Scopus, Web of Science, and Cochrane, and preprint servers", and an assessment of all published articles till 17 February 2023 was done. Studies that provided data on prevalence, mortality and hospitalization among frail patients with cirrhosis were included. The study characteristics and data on the prevalence, mortality, and hospitalization were extracted from included studies. The primary outcome was to estimate the pooled prevalence of frailty and determine its impact on mortality and hospitalization in patients with cirrhosis. Results: Overall, 12 studies were included. Data on prevalence of frailty and mortality were available in 11 studies, while seven studies reported data on hospitalization. The analysis conducted among 6126 patients with cirrhosis revealed pooled prevalence of frailty to be 32% (95% confidence interval [CI], 24-41). A total of 540 events of death revealed a pooled mortality rate of 29% (95% CI, 19-41). Six-month and twelve-month pooled estimates of mortality were found to be 24% (95% CI, 17-33) and 33% (95% CI, 23-45), respectively. The pooled hospitalization rate among the seven studies was 43% (95% CI, 21-68). Conclusion: The prevalence of frailty in patients with cirrhosis is high, leading to poor outcomes. Frailty assessment should become an integral part of cirrhosis evaluation. Registry and registration number of study: PROSPERO 2022 CRD42022377507.

Selenium levels in colorectal cancer: A systematic review and meta-analysis of serum, plasma, and colorectal specimens.

BACKGROUND: Colorectal cancer (CRC) is a growing public health problem. Several clinical studies have shown a potentially protective effect of selenium (Se), but the reports are inconsistent. The objective of the study was to examine the evidence for relation between serum/tissue Se status and CRC. METHOD AND MATERIALS: In this Systematic Review and Meta-Analysis, we searched Cochrane Library, EBSCOhost, EMBASE, ProQuest, PubMed/MEDLINE, Scopus, and Web of Science for studies reporting serum/plasma/whole blood/tissue Se concentrations in CRC patients and controls for articles published till August 2023. Meta-analysis was performed, and study quality, heterogeneity, and small study effects were assessed. Based on a random effects model, summary mean differences in serum levels of Se between CRC patients and healthy controls, and Se levels between malignant and matched non-malignant tissue specimens were assessed. RESULTS: After initial screening, a total of 24 studies (18 serum and 6 tissue studies) with a pooled total of 2640 participants were included in the meta-analysis. CRC patients had significantly lower serum Se levels than healthy controls, being the difference between the two equal to 3.73 µg/dl (95% CI: 6.85-0.61). However, the heterogeneity was very high, I2= 99% (p < 0.01). Our meta-analysis showed higher Se levels in CRC cancerous specimens than in matched healthy colon tissue: the increase was equal to 0.07 µg/g wet tissue weight (95% CI: 0.06-0.09; p= 0.02). CONCLUSIONS: CRC patients have lower serum and higher colon cancerous tissue Se levels. Some factors, such as Se levels in different tumor grades of CRC need to be further considered for a more conclusive association between Se levels and risk of CRC.