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Biomedical subjects

A Peruga

Publications and source records attributed to A Peruga.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of two quantitative GC-MS methods for analysis of tomato aroma based on purge-and-trap and on solid-phase microextraction.

Two analytical procedures, one based on purge-and-trap and the other on solid phase microextraction, both followed by GC-MS measurement using an ion-trap mass spectrometer in the electron impact mode, have been developed for determination and quantitation of up to 39 aroma compounds in fresh tomatoes. The method based on purge-and-trap for isolation of the volatile compounds uses Tenax as adsorbent and a hexane-diethyl ether mixture as solvent for elution. The method was validated for linearity, precision (better than 20% for most compounds), and limit of detection, which was approximately 1 ng g(-1). This method enabled identification of up to 30 compounds in real samples. Use of SPME was considered as an alternative, to simplify sample treatment while maintaining the information level for the samples (e.g. the number of compounds detected) and quality of quantitation. A procedure based on SPME using a Carboxen/polydimethylsiloxane fibre was developed and validated for determination of 29 aroma compounds; precision was better than 20% and limits of detection ranged from 4 to 30 ng g(-1).

Gas Chromatography-Mass Spectrometry↗
PubMed2003

Application of solid-phase microextraction for the determination of pyrethroid residues in vegetable samples by GC-MS.

A solid-phase microextraction (SPME) method has been developed for the determination of 7 pyrethroid insecticides (bifenthrin, lambda-cyhalothrin, permethrin, cyfluthrin, cypermethrin, fenvalerate, and tau-fluvalinate) in water, vegetable (tomato), and fruit (strawberry) samples, based on direct immersion mode and subsequent desorption into the injection port of a GC/MS. The SPME procedure showed linear behavior in the range tested (0.5-50 microg L(-1) in water and 0.01-0.1 mg kg(-1) in tomato) with r(2) values ranging between 0.97 and 0.99. For water samples limits of detection ranged between 0.1 and 2 microg L(-1 )with relative standard deviations lower than 20%. Detection limits for tomato samples were between 0.003 and 0.025 mg kg(-1) with relative standard deviations around 25%. Finally, the SPME procedure has been applied to vegetable (tomato) and fruit (strawberry) samples obtained from an experimental plot treated with lambda-cyhalothrin, and in both cases the analyte was detected and quantified using a calibration curve prepared using blank matrix. SPME has been shown to be a simple extraction technique which has a number of advantages such as solvent-free extraction, simplicity, and compatibility with chromatographic analytical systems. Difficulties with the correct quantification in a complex matrix are also discussed.

Food Analysis↗
PubMed2001

[Availability of condoms in Mexico City].

INTRODUCTION: At the beginning of 1999, Mexico occupied third place, after USA and Brazil, in the number of accumulated cases of AIDS (38,390 notified cases) in America. More than 80% of the cases corresponded to men between 20 and 44 years old. The transmission by sexual route has increased in both sexes, the proportion of men infected by sexual contact increased from 85% in 1991 to 90% in 1998 and in women this proportion increased from 41% in 1991 to 57% in 1998. The ratio male/female of cases of AIDS has varied from 17:1 in 1983 to 6:1 in 1998. Condom use is considered an effective method for the prevention of the transmission of STI's/HIV and therefore the availability is of paramount importance to promote use with the finality of combating these diseases. METHOD: A simple randomized sampling was done in 612 establishments that included: drugstore, bars and nightclubs, hotels and motels, self-service shops and health centers in Mexico City, where am cross sectional study was performed during June and July of 1995, to evaluate the availability of condoms considering three important items: a) percent per capita required to buy an annual endowment of 100 condoms in comparison with this same indicator reported in other countries; b) physical availability, on behalf of the Secretaría de Salud, Mexico City, that considers the volume of existing condoms to be utilized for a year by the public sector in this city; c) physical availability of condoms in different evaluated locations. RESULTS: In order to purchase an annual supply of condoms an individual needs the assign $500 (Pesos) which represents 2.3 to 2.6% of the annual GNP per capita for 1998 and 1997 respectively. The physical availability of condoms, on behalf of the Secretaría de Salud, Mexico City, was 94.9% in health centers. In drugstores, hotels and motels, self-service shops, bars and nightclubs the availability of condoms was 100%, 82.9%, 75% and 1.2%, respectively. CONCLUSIONS: It has been documented that the adequate use of condom is an effective strategy for the prevention of STI's/HIV, therefore the availability of this method of prevention is important to decrease the incidence of these diseases The results of this study indicate that the price for this method of prevention represents an important expense for the homes, which is a limiting factor for condom use, especially for those populations that include adolescents and young adults. It then becomes necessary for Government Institutions to implement programs that will subsidize this method of prevention. Availability is less in self-service shops and practically non-existent in bars and nightclubs. It is suggested that the availability of condom should be mandatory in public places, like bars and nightclubs, where the risk to start casual sexual contact is eminent.

Adolescent↗
PubMed2000

Underestimation of Mycobacterium tuberculosis infection in HIV-infected subjects using reactivity to tuberculin and anergy panel.

BACKGROUND: This study aimed to evaluate purified protein derivative (PPD) reactivity and its interrelationship with anergy panel and CD4+ lymphocytes in HIV-infected subjects as compared to PPD reactivity in HIV-uninfected individuals in a tuberculosis endemic and high Bacillus Calmette-Guérin (BCG) coverage environment. METHODS: Clients of four Mexico City HIV detection centres were screened for HIV-1 antibodies (ELISA or haemagglutination, Western Blot); reactivity to PPD (Mantoux PPD, 5TU RT-23), Candida (1:1000, 0.1 ml), and tetanus toxoid (10Lf, 0.1 ml); and CD4+ T cells. Active tuberculosis was excluded. Informed consent was obtained. RESULTS: From 5130 clients 1168 subjects were enrolled; of these 801 (68.6%) were HIV positive. Reactivity to PPD among HIV-positive subjects was found in 174 (22%), 261 (32.6%), and 296 (37%), at PPD cutoff levels of > or =10 mm, > or =5 mm, and > or =2 mm as compared to 224 (61%) of 367 HIV-negative individuals' reactors to PPD (> or =10 mm) (P < 0.001). After exclusion of anergic individuals using two cutoff levels for cutaneous allergens (< or =2 mm and < or =5 mm), PPD reactivity between HIV-infected and uninfected individuals continued to be significantly different. Only HIV-infected individuals with CD4+ T cells > or =500 cells/mm3 had similar reactivity to PPD as HIV-uninfected individuals. Variables associated with PPD reactivity were CD4+ T cell counts, BCG scar, HIV infection and age. CONCLUSIONS: PPD reactivity was useful to diagnose tuberculosis infection only among HIV-infected individuals with CD4+ counts > or =500 cells/mm3. Among individuals with lower counts, lowering cutoff levels or using anergy panel did not permit comparable reactivity as that observed among HIV-uninfected individuals.

AIDS-Related Opportunistic Infections↗
PubMed2000

[Analysis of participation in surveys in 5 countries: the importance for public health research].

This study compares participation rates and reasons for nonresponse in surveys conducted in five countries of Latin America and the Caribbean. The objective of the surveys was to measure the prevalence of risk behaviors affecting the transmission of human immunodeficiency virus. The surveys were based on probability samples of the population of both sexes between 15 and 49 years old, except in Mexico, where only men were included. Proportions of three components of participation were estimated: residences interviewed, interviewed residences with eligible persons, and eligible persons who completed the interview. In addition, an overall index that combined the three components was calculated. The overall response rate ranged from 35.6% in Mexico to 81.4% in Chile. The component with the greatest variability was the participation of eligible persons, which ranged from 50% in Mexico to 95% in Cuba. These values were lower than what had been expected, especially among men, and will serve to guide future surveys, since rejection rates higher than the ones expected in the protocol should be considered. The results make it possible to infer the validity of the prevalence estimates for the various observed risk behaviors. The results also establish a benchmark to calculate the sample size in future surveys and to improve research methodology.

Adolescent↗
PubMed1999

Factors associated with condom use in the male population of Mexico City.

Sexually transmitted diseases (STDs) are an important public health problem, due to their medical, social and economic repercussions. Therefore, more knowledge is needed about the sexual behaviour that promotes their spread, in order to improve control and prevention strategies. Our aim was to determine the frequency of male condom use associated with sexual behaviour factors, a history of and knowledge about STDs in a sample of the male population in Mexico City. During 1994 a cross-sectional epidemiological study was carried out, using multi-stage sampling with conglomerates, in 1377 men from 15 to 49 years old. The mean age was 34.5 years (SD 7.5 years). Mean age at first sexual relations was 17.7 years (SD 2.8 years). The global proportion of condom use during the last sexual relation was 24.6%; use according to type of female sex partner in the last year was 18.8% with regular partners and 62.5% with occasional partners. The principal predictors of male condom use, identified through statistical modelling, were: younger age (<25 years), middle and high education level (>9 years), middle and high socioeconomic level and type of sexual partners (occasional and regular). This population has risk factors for acquiring and transmitting some STDs, such as occasional sexual partners and a history of STDs. Characteristics which are important in relation to male condom use were identified, such as age (younger than 35), education (complete junior high school or more) and type of sexual partners (occasional and regular).

Adolescent↗
PubMed1999

[Prevalence of hypertension in Valparaíso. Results of the base survey of the CARMEN project (Set of measures for the multifactorial reduction of non-transmissible diseases)].

BACKGROUND: There is little information about the real prevalence of hypertension in Chile. AIM: To assess the adjusted prevalence of hypertension and its main therapeutic measures among adults living in Valparaiso, Chile. MATERIALS AND METHODS: A random sample of dwellings in Valparaiso was chosen. Among these, an individual of 25 to 64 years old was randomly surveyed for risk factors for chronic diseases and sociodemographic parameters. Blood pressure, weight, height, oral glucose tolerance test, fasting cholesterol and triglycerides were also measured. Prevalence was pondered according to age, sex, and probability of selection in the dwelling interior. RESULTS: Three thousand one hundred twelve individuals were studied. The adjusted prevalence of hypertension was 11.4% (11.6% among females and 10.6% among men). The prevalence increased along with age from 3 and 1.9% in men and women of 25 to 34 years old respectively, to 18.2 and 27.4% among men and women of 55 to 64 years old (p < 0.01). People of low socioeconomic level had a higher prevalence of hypertension than those of high socioeconomic level (14.2 and 9.3% respectively, P < 0.05). Diabetes, obesity and hypercholesterolemia were significantly more frequent in subjects with hypertension than in the general population. Forty-four percent of diagnosed hypertensives were receiving medications (angiotensin converting enzyme inhibitors 40%, calcium antagonists 34%, beta blockers 22%). Twenty five percent of patients were treated with a combination of medications. Of those treated, only 22% had normal blood pressure levels at the moment of examination. CONCLUSIONS: High blood pressure is an important public health problem that requires more efficient detection and treatment programs.

Adult↗
PubMed1999

[Risk factors for non communicable diseases: methods and global results of the CARMEN program basal survey].

BACKGROUND: In the last decades, chronic non communicable diseases are becoming the main cause of disability and mortality among adults. The risk factor surveillance and management is the most efficient mean of reducing the impact of these diseases. AIM: To report the results of a non communicable disease risk factor surveillance program in Valparaiso, Chile. MATERIAL AND METHODS: A random samples of people aged 25 to 64 years old living in Valparaiso, Chile was studied. Subjects were questioned about smoking and physical activity habits. Blood pressure, height and weight were measured using standardized techniques at their homes and blood samples were obtained to measure serum lipid levels and oral glucose tolerance test at the nearest outpatient clinic. RESULTS: Of the initial 3852 homes selected, 752 individuals did no agree to answer the inquiry, therefore 3120 subjects were finally interviewed. Of these, 40.6% were smokers, 15% drank alcohol in two or more occasions per month, 84.6% were physically inactive, 19.7% had a body mass index over 30 kg/m2, 11.1% had high blood pressure, 3.9% were diabetic and 46.9% had high serum cholesterol levels. CONCLUSIONS: The basal survey for the CARMEN program shows a high prevalence of cardiovascular risk factors among Chileans.

Adult↗
PubMed1997

Incidence of HIV and HTLV-1 infection among sexually transmitted disease clinic attenders in Jamaica.

Of 970 sexually transmitted disease (STD) patients enrolled at the Comprehensive Health Centre, Kingston, Jamaica, between November 1990 and January 1991, 710 (73%, 333 men and 377 women) were reexamined between January 1992 and July 1993 to estimate the incidence of HIV and HTLV-I infection and to identify risk factors for infection. Of those reexamined, 20% were recruited passively when they returned to the clinic of their own accord, and 80% were recruited actively through field visits to their homes. Passively recruited persons were significantly more likely than active recruits to have had a sexually transmitted disease since enrollment or at their follow-up visit. Seven men and one woman became HIV positive during the period of follow-up. The overall HIV incidence rate was 0.7 per 100 person years (95% confidence interval [CI] = 0.3 to 1.4), 1.4 (CI = 0.6 to 2.8) for men and 0.2 (CI = 0.004 to 0.9) for women. Four of 270 men and 4 of 318 women were HTLV-I positive, an overall incidence of 0.9 per 100 person years (CI = 0.4 to 1.7), 1.0 for men and 0.8 for women. HTLV-I infection was associated with an age of 30 years or older (p < 0.01). The presumed lower transmission probability for HTLV-I may combine with a higher prevalence of HTLV-I in sexual partners to produce similar overall incidence rates for the two infections. The HIV and HTLV-I incidence rates may have been underestimated, because the study subjects who did not return to the clinic may have had a somewhat higher risk. On univariate analysis, there were significant associations between HIV infection in men and drinking alcohol before sex, cocaine use, total number of sex partners, sex with a prostitute since enrollment, ever accepting money for sex, the average number of sex partners per month, bruising during sex, and genital ulcers found on follow-up examination. This analysis needs to be interpreted with caution in view of the small number of seroconverters, which did not allow testing for independent effects in a logistic regression model.

Adult↗
PubMed1996

Trends in cervical cancer mortality in the Americas.

This article presents an assessment of cervical cancer mortality trends in the Americas based on PAHO data. Trends were estimated for countries where data were available for at least 10 consecutive years, the number of cervical cancer deaths was considerable, and at least 75% of the deaths from all causes were registered. In contrast to Canada and the United States, whose general populations had been screened for many years and where cervical cancer mortality has declined steadily (to about 1.4 and 1.7 deaths per 100,000 women, respectively, as of 1990), most Latin American and Caribbean countries with available data have experienced fairly constant levels of cervical cancer mortality (typically in the range of 5-6 deaths per 100,000 women). In addition, several other countries (Chile, Costa Rica, and Mexico) have exhibited higher cervical cancer mortality as well as a number of noteworthy changes in this mortality over time. Overall, while actual declining trends could be masked by special circumstances in some countries, cervical cancer mortality has not declined in Latin America as it has in developed countries. Correlations between declining mortality and the intensity of screening in developed countries suggest that a lack of screening or screening program shortcomings in Latin America could account for this. Among other things, where large-scale cervical cancer screening efforts have been instituted in Latin America and Caribbean, these efforts have generally been linked to family planning and prenatal care programs serving women who are typically under 30; while the real need is for screening of older women who are at substantially higher risk.

Adult↗
PubMed1995

Risk factors for HTLV-I among heterosexual STD clinic attenders.

Human T-cell lymphotropic virus type 1 (HTLV-I) status was assessed in 994 patients attending a sexually transmitted disease (STD) clinic in Kingston, Jamaica, between November 1990 and January 1991 for a new STD complaint. Of 515 heterosexual men, 36 (7.0%) were HTLV-I seropositive, as were 38 (7.9%) of 479 women. HTLV-I seroprevalence increased with age in women. A history of blood transfusion was associated with HTLV-I in both sexes, significantly so in men [odds ratio (OR) 4.7, confidence interval (CI) 1.1-17 for men; OR 1.9, CI 0.6-5.0 for women]. Further analysis excluded all persons reporting a transfusion. On multiple logistic regression analysis, independent associations with HTLV-I infection in men were shown for marital status (OR 3.5, CI 1.2-10 for married/common law vs. single/visiting unions), agricultural occupation (OR 9.0, CI 2.0-41), bruising during sex (OR 2.9, CI 1.0-8.1), > or = 15 years at first sexual intercourse (OR 2.9, CI 1.0-8.2), and a positive test for hepatitis B surface antigen (OR 7.3, CI 1.2-52). In women, associations were shown for two or more sex partners in the 4 weeks prior to complaint (OR 4.9, CI 1.8-13), 11 or more lifetime sexual partners (OR 5.9, CI 1.3-27), aged < 15 years at first sexual intercourse (OR 2.3, 1.0-5.4), bruising during sex (OR 2.7, CI 1.1-6.6), microhaemagglutination-Treponema pallidum positivity (OR 3.6, CI 1.6-8.4), and human immunodeficiency virus infection (OR 14, CI 2.1-92).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

HIV/AIDS and its interaction with tuberculosis in Latin America and the Caribbean.

At present, human immunodeficiency virus (HIV) is thought to have infected over 17 million people worldwide, over 1 million in North America and roughly 2 million in Latin America and the Caribbean. By comparison, infection with the tuberculosis (TB) agent Mycobacterium tuberculosis is far more common, current estimates indicating that roughly one-third of the world's population is infected. These two infections tend to aggravate each other. That is, HIV leads to a progressive immune system depression that favors reactivation of TB in people with latent tuberculous infections; it promotes progression of TB primary infections or reinfections to full-blown tuberculous disease; and it fosters TB transmission, because those simultaneously infected with HIV and M. tuberculosis tend to develop a bacilliferous and contagious TB that can be transmitted to other susceptible individuals, even though the latter are HIV-negative. In addition, this coinfection tends to promote circulation of drug-resistant M. tuberculosis and to produce peculiar manifestations that complicate TB diagnosis, treatment, and control. Overall, it seems clear that the growing threat posed by these associated agents demands effective action in the form of well-coordinated measures involving throughgoing participation by all countries.

AIDS-Related Opportunistic Infections↗
PubMed1994

Rising HIV-1 prevalence among sexually transmitted disease clinic attenders in Jamaica: traumatic sex and genital ulcers as risk factors.

Between November 1990 and January 1991, status of human immunodeficiency virus (HIV) infection was assessed for 522 men and 484 women attending the Comprehensive Health Centre in Kingston, Jamaica, for a new sexually transmitted disease (STD) complaint. Prevalence of HIV type 1 (HIV-1) infection was 3.1% (31 of 1,006), a tenfold rise in seroprevalence in 4.5 years. Nineteen of 517 (3.7%) heterosexual men, 3 of 5 (60%) homosexual/bisexual men, and 9 of 484 (1.9%) women were infected with HIV. In heterosexual men, factors associated with HIV infection after age adjustment included present complaint of genital ulcer [odds ratio (OR) 7.3; 95% confidence interval (CI) 1.4-72], past history of genital ulcer (OR, 4.3; CI, 1.4-12), positive MHATP syphilis serology (OR, 3.4; CI, 1.1-10), sex with a prostitute in the past month (OR, 3.8; CI, 1.1-11). Three or more sex partners in the month prior to complaint (OR, 3.6; CI, 1.0-12), and bruising during sex (OR, 4.0; CI, 1.4-13). On multiple logistic regression analysis, independent associations with HIV infection were shown for bruising during sex (OR, 3.0; CI, 1.1-8.3), positive MHATP syphilis serology (OR, 3.2; CI, 1.1-9.5), and history of genital ulcer (OR, 2.9; CI, 1.0-8.0).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Correlates of AIDS knowledge in samples of the general population.

Eighty studies presenting original research are reviewed to explore the correlates of AIDS knowledge in samples of the general population. Results from these studies indicate that being highly educated, young or white increases the chances of being knowledgeable about AIDS and that a relationship exists between strong religious beliefs or conservative political convictions and low AIDS knowledge. Other social or demographic variables appear to have little effect on AIDS knowledge. Evidence from these studies is divided between findings indicating no association and those showing some relationship between low AIDS knowledge and high level of concern. Restrictive attitudes toward persons with AIDS are associated with low level of knowledge. The literature examining the correlates of AIDS knowledge in samples of the general population is characterized by an abundance of studies with small convenience samples of adolescents or students. Larger and more representative samples of the general population tend to confirm the results of the less methodologically sound convenience samples. However, future studies should take into account potential confounders when examining the relation between knowledge and explanatory variables to assess the nature and reliability of purported associations.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Cardiovascular disease mortality in the Americas.

Despite subregional differences, mortality profiles have undergone major changes in most countries of the Americas. While the proportion of deaths caused by noncommunicable diseases, particularly cardiovascular diseases, has increased, overall age-adjusted mortality rates attributable to all cardiovascular disease are declining in 13 of the 15 countries selected for the present study. About half the countries showed decreasing mortality rates for ischaemic heart disease; the other half had increasing rates. The mortality rates for cerebrovascular disease and hypertensive disease declined in all but four countries. The ischaemic heart disease/cerebrovascular disease mortality ratio increased as a consequence of a greater decline in deaths due to cerebrovascular disease, except in two countries that exhibited a greater decline for ischaemic heart disease. With few exceptions the male-to-female mortality ratios increased for all cardiovascular disease, ischaemic heart disease and cerebrovascular disease, reflecting a greater decline in female mortality. In general there was a decline in all cardiovascular disease mortality for almost every age group in the North American, Southern Cone, English-speaking Caribbean, and Andean subregions, while there were increases in the Central American and Latin Caribbean subregions. The magnitude of the changes was related to the initial level of mortality and the date of onset of the decline. Change began earlier and the declines were largest in the countries with the highest initial mortality levels, whereas in the countries that initially had comparatively low values the mortality rates are still increasing. Insufficient information is available to permit elucidation of the determinants of the changes reported. There has been speculation about the possible role of factors such as demographic and sociocultural changes, changes in lifestyle and subsequently in the prevalence of risk factors for cardiovascular disease, and the increased utilization of advanced diagnostic and therapeutic technologies.

Adolescent↗
PubMed1992

Racial differences in AIDS knowledge among adults.

Adults 18 to 65 years of age (N = 1237) were interviewed by telephone to explore differences in AIDS knowledge between black and white Americans. Adjusted odds ratios were calculated to determine the association between race and AIDS knowledge. Results show no discrepancies between black and white respondents in the level of knowledge about proved HIV transmission modes (odds ratio [OR] = 1.31, 95% confidence interval [CI] 0.90-1.90). Racial differences in the level of knowledge of preventive measures (ORadj = 1.39, 95% CI 1.00-1.94) are due primarily to differences in educational attainment and not to race. However, lack of awareness of the difference between asymptomatic individuals infected with human immunodeficiency virus (HIV) and persons with AIDS (PWAs) remained significantly higher for black than for white respondents (ORadj = 1.81, 95% CI 1.32-2.50) after adjustment for educational attainment. This lack of awarenes may facilitate exposure of a larger proportion of black respondents to HIV. Racial disparities in the level of knowledge about unproved transmission modes also remained after adjustment for educational attainment (ORadj = 1.92, 95% CI 1.37-2.70). To interpret unexplained differences in knowledge, factors related to unaccounted-for socioeconomic confounding and to the effect of several variables involved in the communication process are discussed.

Acquired Immunodeficiency Syndrome↗