Publications by authors named "S Chidambaram"

181 Publications

Mitochondrial and Organellar Crosstalk in Parkinson's Disease.

ASN Neuro 2021 Jan-Dec;13:17590914211028364

College of Pharmacy and Nutrition, 7235University of Saskatchewan, Saskatoon, SK- S7N 5A2, Canada.

Mitochondrial dysfunction is a well-established pathological event in Parkinson's disease (PD). Proteins misfolding and its impaired cellular clearance due to altered autophagy/mitophagy/pexophagy contribute to PD progression. It has been shown that mitochondria have contact sites with endoplasmic reticulum (ER), peroxisomes and lysosomes that are involved in regulating various physiological processes. In pathological conditions, the crosstalk at the contact sites initiates alterations in intracellular vesicular transport, calcium homeostasis and causes activation of proteases, protein misfolding and impairment of autophagy. Apart from the well-reported molecular changes like mitochondrial dysfunction, impaired autophagy/mitophagy and oxidative stress in PD, here we have summarized the recent scientific reports to provide the mechanistic insights on the altered communications between ER, peroxisomes, and lysosomes at mitochondrial contact sites. Furthermore, the manuscript elaborates on the contributions of mitochondrial contact sites and organelles dysfunction to the pathogenesis of PD and suggests potential therapeutic targets.
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http://dx.doi.org/10.1177/17590914211028364DOI Listing
July 2021

Diagnostic accuracy of fresh drooled saliva for SARS-CoV-2 in travelers.

Travel Med Infect Dis 2021 Jul 21;43:102144. Epub 2021 Jul 21.

Infectious Disease Department, Sungai Buloh Hospital, Ministry of Health Malaysia, Malaysia.

Background: The standard for SARS-CoV-2 diagnosis is RT-PCR from nasopharyngeal or oropharyngeal swabs. Major airports require COVID-19 screening, and saliva has the potential as a substitute specimen for SARS-CoV-2 diagnosis. We investigated the utility of fresh drooled saliva against NPS for COVID-19 screening of travelers.

Methods: We recruited 81 travelers and 15 non-travelers (including ten controls) prospectively within a mean of 3·22 days of RT-PCR confirmed COVID-19. Each study participant provided 2 mls of early morning fresh drooled whole saliva separately into a sterile plastic container and GeneFiX™ saliva collection kit. The saliva specimens were processed within 4 h and tested for SARS-CoV-2 genes (E, RdRP, and N2) and the results compared to paired NPS RT-PCR for diagnostic accuracy.

Results: Majority of travellers were asymptomatic (75·0%) with a mean age of 34·26 years. 77 travelers were RT-PCR positive at the time of hospitalization whilst three travelers had positive contacts. In this group, the detection rate for SARS-CoV-2 with NPS, whole saliva, and GeneFiX™ were comparable (89·3%, 50/56; 87·8%, 43/49; 89·6%, 43/48). Both saliva collection methods were in good agreement (Kappa = 0·69). There was no statistical difference between the detection rates of saliva and NPS (p > 0·05). Detection was highest for the N2 gene whilst the E gene provided the highest viral load (mean = 27·96 to 30·10, SD = 3·14 to 3·85). Saliva specimens have high sensitivity (80·4%) and specificity (90·0%) with a high positive predictive value of 91·8% for SARS-CoV-2 diagnosis.

Conclusion: Saliva for SARS-CoV-2 screening is a simple accurate technique comparable with NPS RT-PCR.
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http://dx.doi.org/10.1016/j.tmaid.2021.102144DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8294709PMC
July 2021

Clinical utility and applicability of circulating tumor DNA testing in esophageal cancer: a systematic review and meta-analysis.

Dis Esophagus 2021 Jul 21. Epub 2021 Jul 21.

Department of Surgery and Cancer, Imperial College London, London, UK.

Esophageal cancer is an aggressive malignancy with a relatively poor prognosis even after multimodality therapy. Currently, patients undergo a series of investigations that can be invasive and costly or pose secondary risks to their health. In other malignancies, liquid biopsies of circulating tumor DNA (ctDNA) are used in clinical practice for diagnostic and surveillance purposes. This systematic review summarizes the latest evidence for the clinical applicability of ctDNA technology in esophageal cancer. A systematic review of the literature was performed using MEDLINE, EMBASE, the Cochrane Review and Scopus databases. Articles were evaluated for the use of ctDNA for diagnosis and monitoring of patients with esophageal cancer. Quality assessment of studies was performed using the QUADAS-2 tool. A meta-analysis was performed to assess the diagnostic accuracy of sequencing methodologies. We included 15 studies that described the use of ctDNA technology in the qualitative synthesis and eight studies involving 414 patients in the quantitative analysis. Of these, four studies assessed its utility in cancer diagnosis, while four studies evaluated its use for prognosis and monitoring. The pooled sensitivity and specificity for diagnostic studies were 71.0% (55.7-82.6%) and 98.6% (33.9-99.9%), while the pooled sensitivity and specificity for surveillance purposes were 48.9% (29.4-68.8%) and 95.5% (90.6-97.9%). ctDNA technology is an acceptable method for diagnosis and monitoring with a moderate sensitivity and high specificity that is enhanced in combination with current imaging methods. Further work should demonstrate the practical integration of ctDNA in the diagnostic and surveillance clinical pathway.
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http://dx.doi.org/10.1093/dote/doab046DOI Listing
July 2021

Outcomes of bariatric surgery in extreme obesity: results from the United Kingdom National Bariatric Surgery Registry for patients with a body mass index >70 kg/m.

Surg Obes Relat Dis 2021 Jun 16. Epub 2021 Jun 16.

Department of Bariatric Surgery, St George's University Hospitals NHS Foundation Trust, London, United Kingdom.

Background: Bariatric and metabolic surgery (BMS) is an established safe, effective, and durable treatment for obesity and its complications. However, there is still a paucity of evidence on surgery outcomes in patients suffering from extreme obesity.

Objectives: This study aimed to evaluate outcomes of BMS in weight loss and the resolution of co-morbidities in patients with a body mass index (BMI) ≥70kg/m.

Setting: National Health Service and private hospitals in the United Kingdom.

Methods: This cohort study analyzed prospectively collected records from the UK National Bariatric Surgery Registry of patients with a BMI ≥70 kg/m undergoing Roux-en-Y gastric bypass (RYGB), sleeve gastrectomy (SG), or adjustable gastric band (AGB) between January 2009 and June 2014.

Results: There were 230 patients (64% female) eligible for inclusion in the study: 22 underwent AGB; 102 underwent SG, and 106 underwent RYGB. Preoperative weight and BMI values were comparable (76 ± 7 kg/m for AGB; 75 ± 5 kg/m for SG; 74 ± 5 kg/m for RYGB). The median postoperative follow-up was 13 months for AGB (10-22 mo), 18 for SG (6-28 mo), and 15 for RYGB (6-24 mo). Patients undergoing RYGB and SG exhibited the greatest postoperative total body weight loss (35 ± 13% and 31 ± 15%, respectively; P = .14), which led to postoperative BMIs of 48 ± 10 kg/m and 51 ± 11 kg/m, respectively (P = .14). All procedures conferred a reduction in the incidence of co-morbidities, including type 2 diabetes, and led to improved functional statuses. The overall complication rate was 7%, with 3 deaths (1%) within 30 days of surgery.

Conclusion: This study found that primary BMS in patients with a BMI >70kg/m has an acceptable safety profile and is associated with good medium-term clinical outcomes. RYGB and SG are associated with better weight loss and great improvements in co-morbidities than AGB. Given the noninferiority of SG outcomes and SG's potential for further conversion to other BMS procedures if required, SG may be the best choice for primary BMS in patients with extreme obesity.
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http://dx.doi.org/10.1016/j.soard.2021.06.002DOI Listing
June 2021

Effect of sleep habits on academic performance in schoolchildren age 6 to 12 years: a cross-sectional observation study.

J Clin Sleep Med 2021 Jul 9. Epub 2021 Jul 9.

Department of Pediatrics, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamilnadu, India.

Study Objectives: Sleep plays a vital role in the cognitive and neurodevelopmental outcome of children; therefore, adequate sleep is needed to improve academic performance. Primary objective of the study is to find out the prevalence of sleep behavior and its effect on academic performance in schoolchildren age 6 12 years translating into greater opportunity for healthy development and academic success.

Methods: Our study included 791 healthy children between ages 6 to 12 years from schools part of the Central Board of Secondary Education in the South Indian urban population. Pro forma and The Children's Sleep Habits Questionnaire (CSHQ, along with local language translation) was given to the parents, and any doubts regarding the questionnaire were clarified during parent-teacher meetings. The previous two cycles of academic grades for these children were collected and categorized into A, B, and C grades accordingly. Then the statistical analysis of the filled CSHQ questionnaires was performed .

Results: On analyzing the CSHQ questionnaire, 71.9% of the children studied had a score higher than 41, which is in the clinical range indicating a significant prevalence of altered sleep habits. Other risk factors include nocturnal enuresis (3.5%), snoring (10.6%), night terrors (8%), and teeth grinding (6.4%).

Conclusions: Altered sleep habits have a major effect on the academic performance of the school-age children. Assessment of sleep habits should be included in routine pediatric office visits.
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http://dx.doi.org/10.5664/jcsm.9520DOI Listing
July 2021
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