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Biomedical subjects

P Pais

Publications and source records attributed to P Pais.

At least 19 recordsLinked to original sources
PubMed2001

Pre hospital issues in acute myocardial infarction.

OBJECTIVES: Time is of prime importance in the management of acute myocardial infarction (AMI). Time to hospital admission should be minimised for maximum thrombolytic benefit. The present paper has evaluated some socio-demographic factors influencing pre hospital delay. METHODS: This prospective observational study of 1,072 patients with AMI admitted to 14 hospitals in South India was done over one year. Socio-demographic factors viz. time of symptom onset, place of residence, type of transportation to hospital, distance travelled, as well as clinical and treatment details were recorded. Hospitals were grouped based on their location into metropolitan and town hospitals. RESULTS: Males predominated (85%) and had AMI at a younger age than females. Most patients (74%) travelled less than 30 km to a hospital. The mean distance travelled to a town hospital was longer than that to a metropolitan hospital (24.2 km vs 21 km; p < 0.0001); however there was no significant difference in the type of transportation or time taken to reach either of the hospitals. Majority (79%) of patients arrived at a hospital within the thrombolytic window of 12 hours (mean time = 11 hours). The occurrence of a previous MI had no influence on time taken to hospital arrival, questioning the role of symptom education as an interventional strategy to reduce pre hospital delay. Patients older than 70 years and females in towns with symptom onset during the day (6 am to 6 pm) took a longer time to reach hospital. CONCLUSION: Community facilities do not affect pre hospital delay. Interventions should focus on reducing decision time to call for help and the role of symptom education needs further evaluation.

Community Health Services↗
PubMed2000

Chromatographic and related techniques for the determination of aromatic heterocyclic amines in foods.

Some 20 years ago, Japanese scientists discovered a new group of highly toxic compounds, classified as heterocyclic aromatic amines, from broiled and grilled meat and fish products. Numerous studies have shown that most HAs are mutagenic and carcinogenic, and the safety of HA-containing foods has become a concern for the public. To date, more than 20 different mutagenic and/or carcinogenic heterocyclic amines have been identified in foods. This paper reviews the analysis of foods for HAs with 145 references. We survey some of the numerous methods available for the chromatographic analysis of heterocyclic amines and highlight the recent advances. We discuss chromatographic and related techniques, including capillary electrophoresis, and their coupling to mass spectrometry for the determination of these contaminants in foods. In addition, the review summarises data on the content of HAs in various cooked foods.

Amines↗
PubMed2000

Formation of the mutagen IFP in model systems and detection in restaurant meats.

Mixtures of the free amino acids, creatine and glucose, were dry-heated to model the potential formation of heterocyclic amines in meats. The formation of the mutagenic amine IFP (determined to be 2-amino-(1,6-dimethylfuro[3,2-e]imidazo[4,5-b])pyridine) was investigated by varying heating time, heating temperature, and precursors. With an optimized mixture of glutamine, creatine, and glucose, heated at 200 degrees C for 60 min, 2 mg of IFP was purified for studies to define its structure. Trideuteriomethyl-IFP was made from trideuteriomethylcreatinine in the model system for use in LC-MS detection of IFP in foods. Analysis of well-done meats purchased from restaurants showed about half to contain IFP at levels from 1.4 to 46 ng/g of cooked meat, demonstrating human exposure to this mutagen.

Cooking↗
PubMed1999

Food heating and the formation of heterocyclic aromatic amine and polycyclic aromatic hydrocarbon mutagens/carcinogens.

Heterocyclic aromatic amines (HAA) and polycyclic aromatic hydrocarbons (PAH) are mutagens and animal carcinogens sometimes formed when foods are heated or processed. Determining their role in cancer etiology depends on comparing human exposures and determining any significant dose-related effects. Chemical analysis of foods shows that flame-grilling can form both PAH and HAA, and that frying forms predominantly HAA. With detection limits of about 0.1 ng/g, amounts found in commercially processed or restaurant foods range from 0.1 to 14 ng/g for HAA, and levels of PAH up to 1 ng/g in a liquid smoke flavoring. Laboratory fried samples have greater amounts of PAH, up to 38 ng/g in hamburgers, and high levels of HAA, over 300 ng/g, are measured in grilled chicken breast. Understanding the processing conditions that form PAH and HAA can lead to methods to greatly reduce their occurrence in processed foods.

Amines↗
PubMed1999

Relationship of glucose and insulin levels to the risk of myocardial infarction: a case-control study.

OBJECTIVE: To assess the relationship between dysglycemia and myocardial infarction in nondiabetic individuals. BACKGROUND: Nondiabetic hyperglycemia may be an important cardiac risk factor. The relationship between myocardial infarction and glucose, insulin, abdominal obesity, lipids and hypertension was therefore studied in South Asians-a group at high risk for coronary heart disease and diabetes. METHODS: Demographics, waist/hip ratio, fasting blood glucose (FBG), insulin, lipids and glucose tolerance were measured in 300 consecutive patients with a first myocardial infarction and 300 matched controls. RESULTS: Cases were more likely to have diabetes (OR 5.49; 95% CI 3.34, 9.01), impaired glucose tolerance (OR 4.08; 95% CI 2.31, 7.20) or impaired fasting glucose (OR 3.22; 95% CI 1.51, 6.85) than controls. Cases were 3.4 (95% CI 1.9, 5.8) and 6.0 (95% CI 3.3, 10.9) times more likely to have an FBG in the third and fourth quartile (5.2-6.3 and >6.3 mmol/1); after removing subjects with diabetes, impaired glucose tolerance and impaired fasting glucose, cases were 2.7 times (95% CI 1.5-4.8) more likely to have an FBG >5.2 mmol/l. A fasting glucose of 4.9 mmol/l best distinguished cases from controls (OR 3.42; 95% CI 2.42, 4.83). Glucose, abdominal obesity, lipids, hypertension and smoking were independent multivariate risk factors for myocardial infarction. In subjects without glucose intolerance, a 1.2 mmol/l (21 mg/dl) increase in postprandial glucose was independently associated with an increase in the odds of a myocardial infarction of 1.58 (95% CI 1.18, 2.12). CONCLUSIONS: A moderately elevated glucose level is a continuous risk factor for MI in nondiabetic South Asians with either normal or impaired glucose tolerance.

Biomarkers↗
PubMed1999

Formation of mutagenic/carcinogenic heterocyclic amines in dry-heated model systems, meats, and meat drippings.

Mixtures of amino acids, creatine, and glucose simulating the composition of six different kinds of meats (beef, chicken breast, chicken thigh, turkey breast, pork, and fish) were dry-heated to simulate the formation of heterocyclic amines in meats. The presence of 16 heterocyclic amines was investigated in the model systems and in the six meats and their corresponding meat drippings to determine the importance of meat composition to heterocyclic amine formation. Nine mutagenic amines (IQ, MeIQ, 8-MeIQx, 4,8-DiMeIQx, PhIP, IQx, IFP, DMIP, and TMIP) were found to be present at concentrations >0.1 ng/g in some of the model systems and in some of the meats or pan residues. Heterocyclic amine concentrations clearly are affected by precursor composition in this model system, and the same nine heterocyclic amines formed in the meat and in the model system show that this is a well-controlled surrogate for the reaction conditions that occur in meats during cooking.

Amines↗
PubMed1997

Liquid chromatography-atmospheric-pressure chemical ionization mass spectrometry as a routine method for the analysis of mutagenic amines in beef extracts.

A liquid chromatography-mass spectrometry (LC-MS) method using atmospheric-pressure chemical ionisation as interface was developed for the simultaneous determination of 14 heterocyclic aromatic amines and related compounds in beef extracts. The separation was performed on a conventional C18 column using a binary mobile phase composed of acetonitrile and 50 mM ammonium acetate at pH 5.7, and elution was carried out in gradient mode. Several parameters influencing the mass spectra were optimized, and the effect of the variation of cone voltage on the mass spectra was studied. The [M+H]+ ions and some fragments produced in the source were observed in the mass spectra when several extraction voltages were applied. Quality parameters (run-to-run and day-to-day reproducibility, intervals of linearity, and limits of detection) were studied in the optimum working conditions. The method was used to analyze the heterocyclic amines present in a commercial beef extract. Therefore, a solid-phase extraction clean-up procedure was performed prior the LC-MS analysis due to the complexity of the sample and the compounds Glu-P-1, Harman, Norharman and A alpha C were identified in the samples at ppb levels and successfully confirmed using in-source fragmentation.

Amines↗
PubMed1997

Liquid chromatography-electrospray mass spectrometry with in-source fragmentation for the identification and quantification of fourteen mutagenic amines in beef extracts.

Conditions for the liquid chromatography-electrospray mass spectrometric (LC-ES-MS) determination of the fourteen most abundant heterocyclic amines and related compounds that can be produced in thermally processed foods were established. The simultaneous separation of all HAs on an octadecylsilane microbore column using a gradient elution with 5 mM ammonium acetate, pH 4.0, and acetonitrile was optimized. The mass spectra obtained at different extraction voltages were studied. The highest extraction voltages provided structural information for the characterization of these amines. Good detection limits comparable with those of LC and electrochemical detection were obtained. The method was applied to the analysis of these mutagens in beef extracts after a solid-phase extraction clean-up and in-source fragmentation had been applied for confirmation purposes. The levels of several heterocyclic amines measured were estimated to be in the range of 7.8-135.2 ng g-1.

Amines↗
PubMed1996

Risk factors for acute myocardial infarction in Indians: a case-control study.

BACKGROUND: South Asians who have settled overseas and those in urban India have an increased risk of ischaemic heart disease (IHD). Reasons for this increased risk are unclear. Most studies have been based on migrants to western nations, so their findings may not apply to most south Asians, who live in their own countries. Therefore, we assessed the relative importance of risk factors for IHD among South Asians in Bangalore, India. METHODS: We conducted a prospective hospital-based case-control study of 200 Indian patients with a first acute myocardial infarction (AMI) and 200 age and sex matched controls. We recorded prevalence of the following risk factors for IHD: diet, smoking, alcohol use, socioeconomic status, waist to hip ratio (WHR), blood glucose, serum insulin, oral glucose tolerance test, and lipid profile. FINDINGS: The most important predictor of AMI was current smoking (odds ratio [OR] 3.6, p < 0.001) of cigarettes or beedis (a local form of tobacco), with individuals who currently smoked 10 or more per day having an OR of 6.7 (p < 0.001). History of hypertension and of overt diabetes mellitus were also independent risk factors (OR 2.69 [p = 0.001] and 2.64 [p = 0.004], respectively). Among all individuals, fasting blood glucose was a strong predictor of risk over the entire range, including at values usually regarded as normal (OR adjusted for smoking, hypertension, and WHR 1.62 for 1 SD increase, p < 0.001). Abdominal obesity (as measured by WHR) was also a strong independent predictor across the entire range of measures (OR adjusted for smoking, hypertension, and blood glucose 2.24 for 1 SD increase; p < 0.001). Compared with individuals with no risk factors, individuals with multiple risk factors had greatly increased risk of AMI (eg, OR of 10.6 for the group with smoking and elevated glucose). Lipid profile was not associated with AMI. In univariate analyses, higher socioeconomic (income) status (OR 0.32, p = 0.005 highest vs lowest; OR 0.75 middle vs lowest) and vegetarianism (OR = 0.55, p = 0.006), seemed to be protective. The impact of vegetarianism was closely correlated with blood glucose and WHR. INTERPRETATION: Smoking cessation, treatment of hypertension, and reduction in blood glucose and central obesity (perhaps through dietary modification) may be important in preventing IHD in Asian Indians.

Adult↗
PubMed1996

Solid-phase extraction for the selective isolation of polycyclic aromatic hydrocarbons, azaarenes and heterocyclic aromatic amines in charcoal-grilled meat.

A method for the simultaneous analysis of 12 mutagenic and/or carcinogenic compounds is described; these substances belong to three different chemical groups: polycyclic aromatic hydrocarbons (PAHs), azaarenes, i.e., nitrogen-containing polycyclic aromatic hydrocarbons (PANHs), and heterocyclic aromatic amines (HAAs). The selective enrichment procedure includes coupling of solid-phase extraction (SPE) steps using diatomaceous earth, propylsulfonic acid, silica gel and octadecylsilane columns. The eluted fractions were analysed by high-performance liquid chromatography with UV and electrochemical detection. Levels measured were estimated to be 4-19 ng g-1. Peak confirmation was carried out by GC-MS for both PAHs and PANHs, and by LC with a photodiode array detector for HAAs. The method was applied to the analysis of charcoal-grilled meat and was judged to be generally applicable for detection of these mutagens at the ppb level in processed foods.

Amines↗
PubMed1996

Determination of heterocyclic amines by pneumatically assisted electrospray liquid chromatography-mass spectrometry.

Electrospray ionization mass spectrometry was applied to the study of the amines IQ, Trp-P-1, Trp-P-2, PhIP and A alpha C and the co-mutagens harman and norharman. The results obtained on a triple quadrupole mass spectrometer equipped with a pneumatically assisted electrospray source are reported. The chromatographic conditions were optimized with a reversed-phase column (1 mm I.D.) using acetonitrile-5 mM ammonium acetate (pH 6.7) (50:50) as the mobile phase at a flow-rate of 50 microliters min-1. Different parameters influencing the mass spectra were investigated. For these compounds [M + H]+ in the positive-ion mode and also some fragments produced through collisionally activated decomposition in the interface were observed. Detection limits of 5.4-44 pg were obtained for standard solutions of these amines. Analysis of a meat extract was performed by HPLC-MS using single-ion monitoring after a solid-phase extraction clean-up.

Amines↗
PubMed1996

Isolation by solid-phase extraction and liquid chromatographic determination of mutagenic amines in beef extracts.

A solid-phase extraction method was successfully optimized for the isolation and preconcentration of five mutagenic amines, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole, 3-amino-1-methyl-5H-pyrido[4,3-b]indole, 2-amino-9H-pyrido[2,3-b]indole, 2-amino-3-methyl-9H-pyrido[2,3-b]indole and 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine, and two co-mutagens, 1-methyl-9H-pyrido[4,3-b]indole and 9H-pyrido[4,3-b]indole. Coupling of diatomaceous earth, propylsulphonyl silica gel, and octadecylsilane cartridges was used to separate selectively the imidazopyridine and indolpyridine derivatives from those of quinoxaline and quinoline. A method based on this sample preparation was applied to the determination of twelve heterocyclic amines and related substances in a commercial beef extract using HPLC with electrochemical and fluorescence detection. Good recovery values were obtained, ranging between 55 and 99%. The co-mutagens 1-methyl-9H-pyrido[4,3-b]indole (harman) and 9H-pyrido[4,3-b]indole (norharman) were found in the beef extract at levels of 110 and 53 ng g-1, respectively, and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and 2-amino-9H-pyrido[2,3-b]indole (A alpha C) were tentatively identified.

Amines↗
PubMed1996

HIV and India: looking into the abyss.

Serosurveillance of high risk groups started in India in October 1985. The first positive cases were detected in 1986. As of mid-1994, official figures stood at 15000 HIV positive cases and 559 cases of AIDS. This is most certainly an underestimate because of under reporting. Among high risk groups, prevalence has risen rapidly. Between 1986 and 1994, prevalence has risen from 1.6 to 40.0% in sex workers, 1.4 to 40% in STD clinics and 0 to 70% in i.v. drug abusers in various studies. The penetration into the general population is uncertain. As in Africa, infection has been mainly by heterosexual intercourse, with commercial sex workers, long distance truck drivers and migrant labour serving as vehicles of spread. Other routes of infection are transfusion of blood and blood products and i.v. drug use. Dependence on professional blood donors is the main cause of infected blood supplies. Ninety per cent of cases with HIV infection are aged between 15 and 45 years and belong to socioeconomically disadvantaged groups. The male to female ratio is 5:1, with female cases being mainly sex workers. The predominant virus is HIV-1 but cases with HIV-2 and mixed infection are being reported from port cities. The present situation in India is similar to the early pattern in Africa where a sharp increase in seroprevalence among high risk groups was followed by spread to the general population. Clinical AIDS is still infrequent. From experience so far, pulmonary tuberculosis has been the most common clinical presentation. So far AIDS associated tuberculosis has responded to standard therapy but the development of multi-drug resistant mycobacteria and their spread to the large tuberculous population in the country is a potential threat. Key factors of AIDS/HIV prevention are public education and counselling about the infection and safe sex practices, especially in high risk groups; STD control; promotion of voluntary blood donation and adequate screening of blood products and general and equitable progress in the economic development of the country and its people-much high risk behaviour is driven by poverty.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Correlation between the severity of symptoms in organophosphorus poisoning and cholinesterase activity (RBC and plasma) in humans.

This study was undertaken to examine the correlation, if any, between the inhibition of red blood cell cholinesterase (RBC ChE), plasma cholinesterase (PChE) and cerebrospinal fluid acetyl cholinesterase (CSF AChe) and the severity of symptoms in patients poisoned with organophosphorus (OP) compounds. Baseline values of the cholinesterases (RBC, Plasma & CSF) were established in our laboratory using a modified colorimetric method. OP poisoned patients were divided into 3 groups - mild, moderate and severe based on clinical symptoms. We observed a severity dependent inhibition of both RBC ChE and PChE, in acute poisoning. Sequential post exposure estimations of the ChEs upto 5 days not reveal any rise in the values though there was substantial clinical improvement. Our findings therefore indicate that the correlation of ChE values with severity of symptoms are applicable only in the initial stages of acute poisoning. AChE could not be detected in CSF in two severely neurotoxic patients who subsequently expired. The clinical significance of this observation needs to be examined further.

Cholinesterases↗