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Nair SS, Leitch J, Garg ML. Suppression of inositol phosphate release by cardiac myocytes isolated from fish oil-fed pigs. Mol Cell Biochem 2000; 215:57-64. [PMID: 11204456 DOI: 10.1023/a:1026538932590] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Fatty acid composition of cardiac myocytes and release of inositol phosphates in pigs fed a fish oil supplemented diet was examined. Two groups of female pigs were fed diets supplemented with either 50 g/kg diet beef tallow (as control) or 50 g/kg diet fish oil (MaxEPA) rich in n-3 fatty acids. After 6 weeks of supplementation, the pigs were anesthetized and hearts were removed. Cardiac myocytes were isolated, lipid extracted and separated into non-polar and polar lipids by thin-layer chromatography. Fatty acid composition of individual neutral and polar lipid classes were examined by gas chromatography. To study the effect of membrane phospholipid modification on the phospholipase C (PLC) mediated release of inositol phosphates, cardiac myocytes were labelled with 4 microCi/mL myo-[2-(3)H]inositol for 48 h. After stimulation with epinephrine and phenylephrine, the water soluble [3H]inositol products were extracted, separated from [3H]inositol and [3H]glycerophosphoinositol by chromatography on Dowex AG 1-X8 and quantitated by scintillation counting. Cardiac myocytes isolated from fish oil-fed pigs had higher levels of n-3 polyunsaturated fatty acid in the non-esterified fatty acid and phospholipid fraction. Similarly, these cardiac myocytes had increased level of n-3 fatty and decreased n-6 fatty acids in all the phospholipid fractions, PE, PC, P1 and PS (p < 0.05). After stimulation, the levels of [3H]inositol trisphosphate (IP3) and [3H]inositol tetrakisphosphate (IP4) in cardiac myocytes isolated from fish oil-fed pigs were significantly reduced (p < 0.05) compared to myocytes isolated from beef tallow fed-pigs. This study for the first time has utilised adult cardiac myocytes to demonstrate the effect of n-3 PUFA supplementation on cardiac myocyte phospholipid fatty acid composition and release of second messengers.
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MESH Headings
- Animals
- Arachidonic Acid/metabolism
- Arrhythmias, Cardiac
- Cell Survival
- Cells, Cultured
- Chromatography
- Chromatography, Gas
- Chromatography, Thin Layer
- Dietary Supplements
- Epinephrine/pharmacology
- Fatty Acids/metabolism
- Fatty Acids, Omega-3
- Fatty Acids, Unsaturated/metabolism
- Female
- Fish Oils/pharmacology
- Inositol Phosphates/biosynthesis
- Inositol Phosphates/metabolism
- Lipids/analysis
- Myocardium/cytology
- Phenylephrine/pharmacology
- Phospholipids/metabolism
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, beta/metabolism
- Scintillation Counting
- Swine
- Triglycerides/metabolism
- Type C Phospholipases/metabolism
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Thornton SB, Nair SS. Parametric studies of human thermal mechanisms and measurements. IEEE Trans Biomed Eng 2000; 47:444-51. [PMID: 10763290 DOI: 10.1109/10.828144] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A systematic methodology is proposed for mathematically quantifying the effects of measurement inaccuracies due to instrument uncertainty in a human calorimetry project. Human thermal mechanisms are poorly understood at the systems level and this study investigates the importance of these mechanisms quantitatively. The proposed methodology uses sensitivity derivatives combined with sensor accuracies to quantify the effect of each heat transfer mechanism contributing to the errors in the system equations. The method is applicable to any differentiable model to be validated by experimentation. To illustrate the methodology, two example cases, a reclining nude resting subject and a reclining clothed working subject, are analyzed. The calculated expected errors clearly suggest specific modifications.
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Nair SS, Leitch J, Falconer J, Garg ML. Cardiac (n-3) non-esterified fatty acids are selectively increased in fish oil-fed pigs following myocardial ischemia. J Nutr 1999; 129:1518-23. [PMID: 10419984 DOI: 10.1093/jn/129.8.1518] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The effect of fish oil supplementation on the nonesterified fatty acid (NEFA) concentration and composition in the normoxic and hypoxic myocardium of pigs was examined. Two groups of female pigs (n = 7) were fed a diet supplemented with either 5 g beef tallow/kg (as control) or 5 g fish oil/kg (MaxEPA) rich in (n-3) fatty acids. After 6 wk of supplementation, the pigs were anesthetized, hearts exposed by thoracotomy followed by occlusion of the left anterior descending artery. Normoxic and hypoxic regions of the heart were examined for NEFA concentration and composition by using a combination of thin layer and gas chromatography. Nonesterified (n-6) and (n-3) fatty acid concentration and composition differed significantly between the two groups in both the normoxic and hypoxic areas of the heart. Eicosapentaenoic and docosahexaenoic acid concentration in the NEFA fraction of the normoxic myocardium were higher in the fish oil group than in the beef tallow group (P < 0.001). In the fish oil-fed pigs, the (n-3) NEFA concentration was significantly higher in the hypoxic compared to the normoxic region of the heart. The fish oil-fed group had lower levels of arachidonic acid in the NEFA fraction compared to the beef tallow-fed group, whereas the hypoxic myocardium had higher levels of arachidonic acid, regardless of the dietary fat supplementation. Despite large differences in the proportions of saturated fatty acids in the experimental diets, there was little or no difference in the saturated fatty acid content of cardiac phospholipid and NEFA fractions. Following myocardial ischemia, (n-3) fatty acids in the NEFA fractions were selectively increased in the fish oil-fed pigs, implicating the possible role of nonesterified (n-3) polyunsaturated fatty acids in the prevention of arrhythmias.
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Nair SS, Leitch J, Garg ML. Specific modifications of phosphatidylinositol and nonesterified fatty acid fractions in cultured porcine cardiomyocytes supplemented with n-3 polyunsaturated fatty acids. Lipids 1999; 34:697-704. [PMID: 10478927 DOI: 10.1007/s11745-999-0415-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Mechanisms for the antiarrhythmic effect of n-3 polyunsaturated fatty acids (PUFA) are currently being investigated using isolated cardiac myocytes. It is still not known whether the incorporation of n-3 PUFA into membrane phospholipids is a prerequisite for its protective action or if n-3 PUFA exert antiarrhythmic effects in their nonesterified form as demonstrated by recent studies. Adult porcine cardiomyocytes were grown in media supplemented with arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). After 24 h, analysis of total lipids showed that the myocytes were enriched with the respective fatty acids compared to control cells. Large proportions of all three fatty acids supplemented (69% AA, 72% DHA, and 66% EPA) remained unesterified. Fatty acid analyses of total phospholipids (PL) revealed that the incorporation of EPA and DHA, though small, was significantly different (P<0.05) from that of the control cells. The PL fraction was further separated into phosphatidylinositol (PI), phosphatidylethanolamine, phosphatidylcholine, and phosphatidylserine to study the pattern of incorporation of the fatty acids in these fractions. It became apparent that EPA and DHA were selectively incorporated into the PI fraction. This study demonstrates that in adult porcine cardiomyocytes, the n-3 PUFA supplementation selectively modulates two important lipid fractions, nonesterified fatty acid and PI, which were implicated in the mechanisms of prevention of cardiac arrhythmias.
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Husain SA, Nair J, Holcomb W, Reid JC, Vargas V, Nair SS. Stress reactions of children and adolescents in war and siege conditions. Am J Psychiatry 1998; 155:1718-9. [PMID: 9842781 DOI: 10.1176/ajp.155.12.1718] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This was a study of posttraumatic stress symptoms in children and adolescents during siege conditions in Sarajevo. METHOD Seven hundred ninety-one students aged 7-15 years were surveyed to assess symptoms of posttraumatic stress and level of deprivation. RESULTS Girls reported more stress than boys. Loss of family members and deprivation of basic needs were associated with more symptoms. CONCLUSIONS Personal experiences of siege are related to increased stress.
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Nair SS, Elizabeth MI. Esthesioneuroblastoma. Indian J Otolaryngol Head Neck Surg 1998; 50:33-5. [PMID: 23119374 PMCID: PMC3451258 DOI: 10.1007/bf02996765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Nair SS, Leitch JW, Falconer J, Garg ML. Prevention of cardiac arrhythmia by dietary (n-3) polyunsaturated fatty acids and their mechanism of action. J Nutr 1997; 127:383-93. [PMID: 9082021 DOI: 10.1093/jn/127.3.383] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The role of marine fish oil (n-3) polyunsaturated fatty acids in the prevention of fatal ventricular arrhythmia has been established in experimental animals. Prevention of arrhythmias arising at the onset of ischemia and reperfusion is important because if untreated, they result in sudden cardiac death. Animals supplemented with fish oils in their diet developed little or no ventricular fibrillation after ischemia was induced. Similar effects have also been observed in cultured neonatal cardiomyocytes. Several mechanisms have been proposed and studied to explain the antiarrhythmic effects of fish oil polyunsaturated fatty acids, but to date, no definite mechanism has been validated. The sequence of action of these mechanisms and whether more than one mechanism is involved is also not clear. Some of the mechanisms suggested to explain the antiarrhythmic action of fish oils include the incorporation and modification of cell membrane structure by (n-3) polyunsaturated fatty acids, their direct effect on calcium channels and cardiomyocytes and their role in eicosanoid metabolism. Other mechanisms that are currently being investigated include the role of (n-3) polyunsaturated fatty acids in cell signalling mediated through phosphoinositides and their effect on various enzymes and receptors. This article reviews these mechanisms and the antiarrhythmic studies using (n-3) polyunsaturated fatty acids.
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Kashani JH, Nair SS, Rao VG, Nair J, Reid JC. Relationship of personality, environmental, and DICA variables to adolescent hopelessness: a neural network sensitivity approach. J Am Acad Child Adolesc Psychiatry 1996; 35:640-5. [PMID: 8935211 DOI: 10.1097/00004583-199605000-00019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE This study identified critical factors from a set of psychiatric diagnoses, personality traits, and family and social support variables that relate to hopelessness in adolescents. METHOD One hundred fifty adolescents were selected in a systematic sample from 1,700 high school students; they completed the Millon Adolescent Personality Inventory, the Parental Bonding Questionnaire, the Social Support Questionnaire, the Hopelessness Scale for Children and were interviewed by trained clinicians on the Diagnostic Interview for Children and Adolescents. Selected variables were chosen for a back-propagation neural network model and for subsequent sensitivity and statistical analysis. RESULTS Sensitive adolescents and adolescents with less impulse control scored high on hopelessness. Forceful adolescents were less hopeless. CONCLUSIONS Using the neural network models, the authors suggest that assertive training as well as group activities that increase cooperativeness may ameliorate hopelessness.
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Reid JC, Nair SS, Kashani JH, Rao VG. Detecting dysfunctional behavior in adolescents: the examination of relationships using neural networks. PROCEEDINGS. SYMPOSIUM ON COMPUTER APPLICATIONS IN MEDICAL CARE 1994:743-6. [PMID: 7950023 PMCID: PMC2247956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We describe a neural network that models the effect of personality, social, and environmental variables on hopelessness in adolescents. A sensitivity analysis suggests the effect that variation in each of the input variables will have on the output. Clinical implications are that health professionals can focus their attention on the variables most likely to impact upon the outcome.
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Girija AS, Nair SS. Occipital tumour with cerebello-pontine angle manifestation. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 1986; 34:378-9. [PMID: 3489708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Nair SS. India well prepared for meeting future goals. ASIAN-PACIFIC POPULATION PROGRAMME NEWS 1982; 11:30-1. [PMID: 12279376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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Nair SS, Askari AD, Popelka CG, Kleinerman JF. Pulmonary hypertension and systemic lupus erythematosus. ARCHIVES OF INTERNAL MEDICINE 1980; 140:109-11. [PMID: 7352785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A combination of systemic lupus erythematosus (SLE) and fatal pulmonary hypertension occurred in a patient who, to our knowledge, had the highest pulmonary artery pressure (120/65 mm Hg) reported without any clinical or autopsy findings of pulmonary interstitial disease or vasculitis. The gradual development of pulmonary hypertension over years is a rare complication in patients with SLE.
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Shah PM, Karande SC, Panjabi GT, Nair SS. Use of jet injectors for B.C.G. vaccination. Indian Pediatr 1978; 15:117-20. [PMID: 680956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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40
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Shah PM, Nair SS. Physical growth of infants on vegetable based infant food. Indian Pediatr 1978; 15:133-41. [PMID: 680957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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41
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Nair SS. A simple model for planning and assessment of programmes for tuberculosis control. Indian J Public Health 1977; 21:111-31. [PMID: 615153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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42
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Rajalakshmi R, Nair SS. Estimation of number of repeat examinations required to detect all tuberculosis cases in the community. Indian J Public Health 1977; 20:118-21. [PMID: 411750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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43
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Nair SS. Application of operations research approach in evolving a national tuberculosis programme. Indian J Public Health 1977; 21:3-7. [PMID: 608768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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44
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Gothi GD, Narayan R, Nair SS, Chakraborty AK, Srikantaramu N. Estimation of prevalence of bacillary tuberculosis on the basis of chest X-ray and/or symptomatic screening. Indian J Med Res 1976; 64:1150-9. [PMID: 1086830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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45
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Chakraborty AK, Ganapathy KT, Nair SS, Bhushan K. Prevalence of non-specific sensitivity of tuberculin in a South Indian rural population. Indian J Med Res 1976; 64:639-51. [PMID: 965065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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46
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Srikantaramu N, B aily GV, Nair SS. An operational model of the District Tuberculosis Programme. Indian J Public Health 1976; 20:3-8. [PMID: 1022704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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47
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Nair SS, Seeta MA, Arora BC. Educational and training requirements of health care delivery system. NIHAE BULLETIN 1975; 9:295-307. [PMID: 10236546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Bhushan K, Baily GV, Nair SS, Ganapathy KT, Singh V. Freeze dried BCG vaccine sealed in presence of nitrogen. Indian J Med Res 1975; 63:1335-43. [PMID: 1222982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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49
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Nair SS. Some thoughts on reorganisation of health care delivery system in India. NIHAE BULLETIN 1974; 8:183-8. [PMID: 10238132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Waaler HT, Gothi GD, Baily GV, Nair SS. Tuberculosis in rural South India. A study of possible trends and the potential impact of antituberculosis programmes. Bull World Health Organ 1974; 51:263-71. [PMID: 4549350 PMCID: PMC2366280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Data on the dynamics of the tuberculosis situation in rural South India, obtained by the National Tuberculosis Institute, Bangalore, were fed into a mathematical model. By this means predictions about the future tuberculosis situation have been made under a wide range of hypothetical assumptions.
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