1.Increasing the quality of reconstructed signal in compressive sensing utilizing Kronecker technique.
H ZANDDIZARI ; S RAJAN ; Houman ZARRABI
Biomedical Engineering Letters 2018;8(2):239-247
Quality of reconstruction of signals sampled using compressive sensing (CS) algorithm depends on the compression factor and the length of the measurement. A simple method to pre-process data before reconstruction of compressively sampled signals using Kronecker technique that improves the quality of recovery is proposed. This technique reduces the mutual coherence between the projection matrix and the sparsifying basis, leading to improved reconstruction of the compressed signal. This pre-processing method changes the dimension of the sensing matrix via the Kronecker product and sparsity basis accordingly. A theoretical proof for decrease in mutual coherence using the proposed technique is also presented. The decrease of mutual coherence has been tested with different projection matrices and the proposed recovery technique has been tested on an ECG signal from MIT Arrhythmia database. Traditional CS recovery algorithms has been applied with and without the proposed technique on the ECG signal to demonstrate increase in quality of reconstruction technique using the new recovery technique. In order to reduce the computational burden for devices with limited capabilities, sensing is carried out with limited samples to obtain a measurement vector. As recovery is generally outsourced, limitations due to computations do not exist and recovery can be done using multiple measurement vectors, thereby increasing the dimension of the projection matrix via the Kronecker product. The proposed technique can be used with any CS recovery algorithm and be regarded as simple pre-processing technique during reconstruction process.
Arrhythmias, Cardiac
;
Electrocardiography
;
Methods
2.Dental Undergraduatesâ’ Self-Assessed Confidence In Paediatric Dentistry
Wong SWY ; Wong XQ ; Vaithilingam RD ; Rajan S
Annals of Dentistry 2015;22(2):1-9
Aim: Self-assessment based on benchmarked professional standards is an excellent tool to assist inimproving the dental curriculum. Areas of strength and weaknesses can be identified. It can also actas a baseline standard when significant changes are introduced to the dental curriculum. The aimsof this prospective cross-sectional study was to investigate self-assessed confidence of final yeardental undergraduates in paediatric dentistry enrolled at University of Malaya in 2013. Methods: 65undergraduates completed anonymised questionnaires which were formulated based on expectedprofessional competencies in three domains namely clinical skills, patient management, and professionaldevelopment and clinical governance. Visual analogue score (VAS) represented by a 10cm line withscore ‘0’ no confidence at all and ‘10’ complete confidence was used to measure the level of confidence.Results: The overall analysis of self-assessed confidence was very positive with median VAS ≥ 5cmin; clinical skills, 7.66±1.31cm (range=2.41–9.97cm: n=62; 95.4%), patient management 7.73±1.27cm(range=5.09–9.95cm: n=64; 100.0%), and professional development and clinical governance,8.13±1.21cm (range=5.22–10.00cm: n=64; 100.0%). High confidence was reported for routine dental care(fillings and preventive care) while lower confidence reported for basic life support (median VAS=5.65cm)and pulp therapy for immature permanent teeth (median VAS=5.95cm). Conclusions: The final yeardental undergraduate students of the University of Malaya appear to have good overall self-assessedconfidence in core areas in paediatric dentistry.
3.Relation between heart rate variability and spectral analysis of electroencephalogram in chronic neuropathic pain patients
John RAJAN ; Girwar Singh GAUR ; Karthik SHANMUGAVEL ; Adinarayanan S
The Korean Journal of Physiology and Pharmacology 2024;28(3):253-264
Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis.Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals.LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP.These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.
4.The effects of naringenin and naringin on the glucose uptake and AMPK phosphorylation in high glucose treated HepG2 cells
Lakshi A. DAYARATHNE ; Sachithra S. RANAWEERA ; Premkumar NATRAJ ; Priyanka RAJAN ; Young Jae LEE ; Chang-Hoon HAN
Journal of Veterinary Science 2021;22(6):e92-
Background:
Naringin and its aglycone naringenin are citrus-derived flavonoids with several pharmacological effects. On the other hand, the mechanism for the anti-diabetic effects of naringenin and naringin are controversial and remain to be clarified further.
Objective:
This study examined the relationship between glucose uptake and AMP-activated protein kinase (AMPK) phosphorylation by naringenin and naringin in high glucose-treated HepG2 cells.
Methods:
Glucose uptake was measured using the 2-NBDG fluorescent d-glucose analog. The phosphorylation levels of AMPK and GSK3β (Glycogen synthase kinase 3 beta) were observed by Western blotting. Molecular docking analysis was performed to evaluate the binding affinity of naringenin and naringin to the γ-subunit of AMPK.
Results:
The treatment with naringenin and naringin stimulated glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells. Both flavonoids increased glucose uptake by promoting the phosphorylation of AMPK at Thr172 and increased the phosphorylation of GSK3β. Molecular docking analysis showed that both naringenin and naringin bind to the γ-subunit of AMPK with high binding affinities. In particular, naringin showed higher binding affinity than the true modulator, AMP with all three CBS domains (CBS1, 3, and 4) in the γ-subunit of AMPK. Therefore, both naringenin and naringin could be positive modulators of AMPK activation, which enhance glucose uptake regardless of insulin stimulation in high glucose-treated HepG2 cells.
Conclusions
The increased phosphorylation of AMPK at Thr172 by naringenin and naringin might enhance glucose uptake regardless of insulin stimulation in high glucose treated HepG2 cells.
5.Anti-adipogenic effect of the flavonoids through the activation of AMPK in palmitate (PA)-treated HepG2 cells
Priyanka RAJAN ; Premkumar NATRAJ ; Sachithra S. RANAWEERA ; Lakshi A. DAYARATHNE ; Young Jae LEE ; Chang-Hoon HAN
Journal of Veterinary Science 2022;23(1):e4-
Objectives:
The present study observed the anti-adipogenic effects of five major citrus flavonoids, including hesperidin (HES), narirutin (NAR), nobiletin (NOB), sinensetin (SIN), and tangeretin (TAN), on AMP-activated protein kinase (AMPK) activation in palmitate (PA)-treated HepG2 cells.
Methods:
The intracellular lipid accumulation and triglyceride (TG) contents were quantified by Oil-red O staining and TG assay, respectively. The glucose uptake was assessed using 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose (2-NBDG) assay. The levels of AMPK, acetyl-CoA carboxylase (ACC), and glycogen synthase kinase 3 beta (GSK3β) phosphorylation, and levels of sterol regulatory element-binding protein 2 (SREBP-2) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression were analyzed by Western blot analysis. The potential interaction between the flavonoids and the γ-subunit of AMPK was investigated by molecular docking analysis.
Results:
The flavonoid treatment reduced both intracellular lipid accumulation and TG content in PA-treated HepG2 cells significantly. In addition, the flavonoids showed increased 2-NBDG uptake in an insulin-independent manner in PA-treated HepG2 cells. The flavonoids increased the AMPK, ACC, and GSK3β phosphorylation levels and decreased the SREBP-2 and HMGCR expression levels in PA-treated HepG2 cells. Molecular docking analysis showed that the flavonoids bind to the CBS domains in the regulatory γ-subunit of AMPK with high binding affinities and could serve as potential AMPK activators.
Conclusion
The overall results suggest that the anti-adipogenic effect of flavonoids on PAtreated HepG2 cells results from the activation of AMPK by flavonoids.
6.Restoration of the adipogenic gene expression by naringenin and naringin in 3T3-L1 adipocytes
Lakshi A. DAYARATHNE ; Sachithra S. RANAWEERA ; Premkumar NATRAJ ; Priyanka RAJAN ; Young Jae LEE ; Chang-Hoon HAN
Journal of Veterinary Science 2021;22(4):e55-
Background:
Naringenin and its glycoside naringin are well known citrus flavonoids with several therapeutic benefits. Although the anti-adipogenic effects of naringenin and naringin have been reported previously, the detailed mechanism underlying their anti-adipogenesis effects is poorly understood.
Objectives:
This study examined the anti-adipogenic effects of naringenin and naringin by determining differential gene expression patterns in these flavonoids-treated 3T3-L1 adipocytes.
Methods:
Lipid accumulation and triglyceride (TG) content were determined by Oil red O staining and TG assay. Glucose uptake was measured using a 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose fluorescent d-glucose analog. The phosphorylation levels of AMP-activated protein kinase (AMPK) and acetyl Co-A carboxylase (ACC) were observed via Western blot analysis. Differential gene expressions in 3T3-L1 adipocytes were evaluated via RNA sequencing analysis.
Results:
Naringenin and naringin inhibited both lipid accumulation and TG content, increased phosphorylation levels of both AMPK and ACC and decreased the expression level of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) in 3T3-L1 adipocytes. RNA sequencing analysis revealed that 32 up-regulated (> 2-fold) and 17 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Scd1, Mogat1, Dgat, Lipin1, Cpt1a, and Lepr, were normalized to the control level in naringenin-treated adipocytes. In addition, 25 up-regulated (> 2-fold) and 25 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Fabp5, Scd1, Srebf1, Hmgcs1, Cpt1c, Lepr, and Lrp1, were normalized to the control level by naringin.
Conclusions
The results indicate that naringenin and naringin have anti-adipogenic potentials that are achieved by normalizing the expression levels of lipid metabolism-related genes that were perturbed in differentiated 3T3-L1 cells.
7.Restoration of the adipogenic gene expression by naringenin and naringin in 3T3-L1 adipocytes
Lakshi A. DAYARATHNE ; Sachithra S. RANAWEERA ; Premkumar NATRAJ ; Priyanka RAJAN ; Young Jae LEE ; Chang-Hoon HAN
Journal of Veterinary Science 2021;22(4):e55-
Background:
Naringenin and its glycoside naringin are well known citrus flavonoids with several therapeutic benefits. Although the anti-adipogenic effects of naringenin and naringin have been reported previously, the detailed mechanism underlying their anti-adipogenesis effects is poorly understood.
Objectives:
This study examined the anti-adipogenic effects of naringenin and naringin by determining differential gene expression patterns in these flavonoids-treated 3T3-L1 adipocytes.
Methods:
Lipid accumulation and triglyceride (TG) content were determined by Oil red O staining and TG assay. Glucose uptake was measured using a 2-[N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose fluorescent d-glucose analog. The phosphorylation levels of AMP-activated protein kinase (AMPK) and acetyl Co-A carboxylase (ACC) were observed via Western blot analysis. Differential gene expressions in 3T3-L1 adipocytes were evaluated via RNA sequencing analysis.
Results:
Naringenin and naringin inhibited both lipid accumulation and TG content, increased phosphorylation levels of both AMPK and ACC and decreased the expression level of 3-hydroxy-3-methylglutaryl CoA reductase (HMGCR) in 3T3-L1 adipocytes. RNA sequencing analysis revealed that 32 up-regulated (> 2-fold) and 17 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Scd1, Mogat1, Dgat, Lipin1, Cpt1a, and Lepr, were normalized to the control level in naringenin-treated adipocytes. In addition, 25 up-regulated (> 2-fold) and 25 down-regulated (< 0.6-fold) genes related to lipid metabolism, including Acaca, Fasn, Fabp5, Scd1, Srebf1, Hmgcs1, Cpt1c, Lepr, and Lrp1, were normalized to the control level by naringin.
Conclusions
The results indicate that naringenin and naringin have anti-adipogenic potentials that are achieved by normalizing the expression levels of lipid metabolism-related genes that were perturbed in differentiated 3T3-L1 cells.
8.Surgical outcomes and strategy of hypertrophic obstructive cardiomyopathy.
Ya-bin ZHU ; S RAJAN ; V M KURIAN ; Zhi-yong LIU
Journal of Zhejiang University. Science. B 2006;7(2):148-153
OBJECTIVETo evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy.
METHODSWe retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and Madras Medical Mission in India. Myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair (anterior mitral leaflet plication); 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall's procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge.
RESULTSOne patient died of post-operative heart failure. The mean follow-up time was 4.3 years. There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association (NYHA) Classes I-II due to associated valvular lesions.
CONCLUSIONOur experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion (SAM) of the mitral valve leaflet, which could not be avoided by other non-surgical treatment.
Adolescent ; Adult ; Aortic Valve ; surgery ; transplantation ; Cardiac Surgical Procedures ; Cardiomyopathy, Hypertrophic ; surgery ; China ; Coronary Artery Bypass ; Female ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; methods ; Humans ; India ; Male ; Middle Aged ; Mitral Valve ; pathology ; surgery ; transplantation ; Treatment Outcome
9.Evaluation of Xpert MTB/RIF assay performance in the diagnosis of abdominal tuberculosis.
Suraj KUMAR ; Sawan BOPANNA ; Saurabh KEDIA ; Pratap MOULI ; Rajan DHINGRA ; Rajesh PADHAN ; Mikashmi KOHLI ; Jigyasa CHAUBEY ; Rohini SHARMA ; Prasenjit DAS ; S DATTAGUPTA ; Govind MAKHARIA ; SK SHARMA ; Vineet AHUJA
Intestinal Research 2017;15(2):187-194
BACKGROUND/AIMS: The use of genetic probes for the diagnosis of pulmonary tuberculosis (TB) has been well described. However, the role of these assays in the diagnosis of intestinal tuberculosis is unclear. We therefore assessed the diagnostic utility of the Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) assay, and estimated the prevalence of multidrug-resistant (MDR) TB in the Indian population. METHODS: Of 99 patients recruited, 37 had intestinal TB; two control groups comprised 43 with Crohn's disease (CD) and 19 with irritable bowel syndrome. Colonoscopy was performed before starting any therapy; mucosal biopsies were subjected to histopathology, acid-fast bacilli staining, Lowenstein-Jensen culture, and nucleic acid amplification testing using the Xpert MTB/RIF assay. Patients were followed up for 6 months to confirm the diagnosis and response to therapy. A composite reference standard was used for diagnosis of TB and assessment of the diagnostic utility of the Xpert MTB/RIF assay. RESULTS: Of 37 intestinal TB patients, the Xpert MTB/RIF assay was positive in three of 37 (8.1%), but none had MDR-TB. The sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert MTB/RIF assay was 8.1%, 100%, 100%, and, 64.2%, respectively. CONCLUSIONS: The Xpert MTB/RIF assay has low sensitivity but high specificity for intestinal TB, and may be helpful in endemic tuberculosis areas, when clinicians are faced with difficulty differentiating TB and CD. Based on the Xpert MTB/RIF assay, the prevalence of intestinal MDR-TB is low in the Indian population.
Biopsy
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Colonoscopy
;
Crohn Disease
;
Diagnosis*
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Humans
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Irritable Bowel Syndrome
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Mycobacterium
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Nucleic Acid Amplification Techniques
;
Prevalence
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Sensitivity and Specificity
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Tuberculosis*
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Tuberculosis, Multidrug-Resistant
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Tuberculosis, Pulmonary
10.Role of random biopsies in surveillance of dysplasia in ulcerative colitis patients with high risk of colorectal cancer.
Sawan BOPANNA ; Maitreyee ROY ; Prasenjit DAS ; S DATTAGUPTA ; V SREENIVAS ; V Pratap MOULI ; Saurabh KEDIA ; Rajan DHINGRA ; Rajesh PRADHAN ; N Suraj KUMAR ; Dawesh P YADAV ; Govind MAKHARIA ; Vineet AHUJA
Intestinal Research 2016;14(3):264-269
BACKGROUND/AIMS: Recent data suggest that the incidence of ulcerative colitis (UC) related colorectal cancer (CRC) in India is similar to that of West. The optimum method for surveillance is still a debate. Surveillance with random biopsies has been the standard of care, but is a tedious process. We therefore undertook this study to assess the yield of random biopsy in dysplasia surveillance. METHODS: Between March 2014 and July 2015, patients of UC attending the Inflammatory Bowel Disease clinic at the All India Institute of Medical Sciences with high risk factors for CRC like duration of disease >15 years and pancolitis, family history of CRC, primary sclerosing cholangitis underwent surveillance colonoscopy for dysplasia. Four quadrant random biopsies at 10 cm intervals were taken (33 biopsies). Two pathologists examined specimens for dysplasia, and the yield of dysplasia was calculated. RESULTS: Twenty-eight patients were included. Twenty-six of these had pancolitis with a duration of disease greater than 15 years, and two patients had associated primary sclerosing cholangis. No patient had a family history of CRC. The mean age at onset of disease was 28.89±8.73 years and the duration of disease was 19.00±8.78 years. Eighteen patients (64.28%) were males. A total of 924 biopsies were taken. None of the biopsies revealed any evidence of dysplasia, and 7/924 (0.7%) were indefinite for dysplasia. CONCLUSIONS: Random biopsy for surveillance in longstanding extensive colitis has a low yield for dysplasia and does not suffice for screening. Newer techniques such as chromoendoscopy-guided biopsies need greater adoption.
Age of Onset
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Biopsy*
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Cholangitis, Sclerosing
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Colitis
;
Colitis, Ulcerative*
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Colonoscopy
;
Colorectal Neoplasms*
;
Humans
;
Incidence
;
India
;
Inflammatory Bowel Diseases
;
Male
;
Mass Screening
;
Methods
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Risk Factors
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Standard of Care
;
Ulcer*