Human Pesticide Exposure in Bolivia: A Scoping Review of Current Knowledge, Future Challenges and Research Needs.

Numerous studies have shown that pesticide exposure is linked to adverse health outcomes. Nevertheless, in Bolivia, where there is an increasing use of pesticides, the literature is sparse. To address knowledge gaps and guide future research in Bolivia, we conducted a scoping review spanning 22 years (January 2000 to December 2022). Our search identified 39 peer-reviewed articles, 27 reports/documents on Bolivian regulations, and 12 other documents. Most studies focused on farmers and revealed high pesticide exposure levels, assessed through biomarkers of exposure, susceptibility, and effect. The literature explored a range of health effects due to pesticide exposure, spanning from acute to chronic conditions. Many studies highlighted the correlation between pesticide exposure and genotoxic damage, measured as DNA strand breaks and/or micronuclei formation. This was particularly observed in farmers without personal protection equipment (PPE), which increases the risk of developing chronic diseases, including cancer. Recent findings also showed the alarming use of banned or restricted pesticides in Bolivian crops. Despite existing Bolivian regulations, the uncontrolled use of pesticides persists, leading to harmful health effects on the population and increasing land and water pollution. This review underscores the need for the stringent enforcement of regulations and continued research efforts, and it provides a scientific foundation for decision-making by relevant authorities.

Genotoxicity in humans exposed to arsenic, lithium, and boron in drinking water in the Bolivian Andes-A cross sectional study.

Elevated concentrations of arsenic, lithium and boron in drinking water have already been reported in Bolivia. Arsenic is known to cause genotoxicity but that caused by lithium and boron is less well known. The aim of the present cross-sectional study was to evaluate potential genotoxic effects of exposure to arsenic, while considering exposure to lithium and boron and genetic susceptibility. Women (n = 230) were recruited in villages located around Lake Poopó. Exposure to arsenic was determined as the sum of concentrations of arsenic metabolites inorganic arsenic, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine. Exposure to lithium and boron was determined based on their concentrations in urine. Genetic susceptibility was determined by GSTM1 (glutathione S-transferase-mu-1) and GSTT1 (glutathione S-transferase-theta-1) null genotypes and AS3MT (Arsenite Methyltransferase) rs3740393. Genotoxicity was measured in peripheral blood leukocytes using the comet assay. The geometric means of arsenic, lithium, and boron concentrations were 68, 897, and 3972 µg/L, respectively. GSTM1 and GSTT1 null carriers had more DNA strand breaks than gene carriers (p = .008, p = .005). We found no correlation between urinary arsenic and DNA strand breaks (rS = .03, p = .64), and only a weak non-significant positive association in the adjusted multivariate analysis (ß = .09 [-.03; .22], p = .14). Surprisingly, increasing concentrations of lithium in urine were negatively correlated with DNA strand breaks (rS = -.24, p = .0006), and the association persisted in multivariate analysis after adjusting for arsenic (ß = -.22 [-.36; -.08], p = .003). We found no association between boron and DNA strand breaks. The apparent protective effect of lithium merits further investigation.

Health Effects of Pesticide Exposure in Latin American and the Caribbean Populations: A Scoping Review.

BACKGROUND: Multiple epidemiological studies have shown that exposure to pesticides is associated with adverse health outcomes. However, the literature on pesticide-related health effects in the Latin American and the Caribbean (LAC) region, an area of intensive agricultural and residential pesticide use, is sparse. We conducted a scoping review to describe the current state of research on the health effects of pesticide exposure in LAC populations with the goal of identifying knowledge gaps and research capacity building needs. METHODS: We searched PubMed and SciELO for epidemiological studies on pesticide exposure and human health in LAC populations published between January 2007 and December 2021. We identified 233 publications from 16 countries that met our inclusion criteria and grouped them by health outcome (genotoxicity, neurobehavioral outcomes, placental outcomes and teratogenicity, cancer, thyroid function, reproductive outcomes, birth outcomes and child growth, and others). RESULTS: Most published studies were conducted in Brazil (37%, n=88) and Mexico (20%, n=46), were cross-sectional in design (72%, n=167), and focused on farmworkers (45%, n=105) or children (21%, n=48). The most frequently studied health effects included genotoxicity (24%, n=62) and neurobehavioral outcomes (21%, n=54), and organophosphate (OP) pesticides were the most frequently examined (26%, n=81). Forty-seven percent (n=112) of the studies relied only on indirect pesticide exposure assessment methods. Exposure to OP pesticides, carbamates, or to multiple pesticide classes was consistently associated with markers of genotoxicity and adverse neurobehavioral outcomes, particularly among children and farmworkers. DISCUSSION: Our scoping review provides some evidence that exposure to pesticides may adversely impact the health of LAC populations, but methodological limitations and inconsistencies undermine the strength of the conclusions. It is critical to increase capacity building, integrate research initiatives, and conduct more rigorous epidemiological studies in the region to address these limitations, better inform public health surveillance systems, and maximize the impact of research on public policies. https://doi.org/10.1289/EHP9934.

Human adaptation to arsenic in Bolivians living in the Andes.

Humans living in the Andes Mountains have been historically exposed to arsenic from natural sources, including drinking water. Enzymatic methylation of arsenic allows it to be excreted more efficiently by the human body. Adaptation to high-arsenic environments via enhanced methylation and excretion of arsenic was first reported in indigenous women in the Argentinean Andes, but whether adaptation to arsenic is a general phenomenon across native populations from the Andes Mountains remains unclear. Therefore, we evaluated whether adaptation to arsenic has occurred in the Bolivian Andes by studying indigenous groups who belong to the Aymara-Quechua and Uru ethnicities and have lived in the Bolivian Andes for generations. Our population genetics methods, including genome-wide selection scans based on linkage disequilibrium patterns and allele frequency differences, in combination with targeted and whole-genome sequencing and genotype-phenotype association analyses, detected signatures of positive selection near the gene encoding arsenite methyltransferase (AS3MT), the main arsenic methylating enzyme. This was among the strongest selection signals (top 0.5% signals via locus-specific branch length and extended haplotype homozygosity tests) at a genome-wide level in the Bolivian study groups. We found a large haplotype block of 676 kb in the AS3MT region and identified candidate functional variants for further analysis. Moreover, our analyses revealed associations between AS3MT variants and the fraction of mono-methylated arsenic in urine and showed that the Bolivian study groups had the highest frequency of alleles associated with more efficient arsenic metabolism reported so far. Our data support the idea that arsenic exposure has been a driver for human adaptation to tolerate arsenic through more efficient arsenic detoxification in different Andean populations.

Arsenic exposure and biomarkers for oxidative stress and telomere length in indigenous populations in Bolivia.

BACKGROUND: Women living in the Bolivian Andes are environmentally exposed to arsenic, yet there is scarce information about arsenic-related effects in this region. Several biomarkers for telomere length and oxidative stress (mitochondrial DNA copy number, mtDNAcn; 8-Oxo-2'-deoxyguanosine, 8-oxo-dG; and 4-hydroxy nonenal mercapturic acid, 4-HNE-MA) have been previously linked to arsenic, and some of which are prospective biomarkers for cancer risk. OBJECTIVE AND HYPOTHESIS: To evaluate associations between arsenic exposure and telomere length, mtDNAcn, 8-oxo-dG, and 4-HNE-MA in Bolivians. Arsenic exposure was hypothesized to be positively associated with all four toxicity biomarkers, particularly in individuals with a less efficient arsenic metabolism. METHODS: The study encompassed 193 indigenous women. Arsenic exposure was assessed in urine as the sum of inorganic arsenic metabolite concentrations (U-As) measured by HPLC-HG-ICP-MS, and in whole blood as total arsenic (B-As) measured by ICP-MS. Efficiency of arsenic metabolism was evaluated by a polymorphism (rs3740393) in the main arsenic methylating gene AS3MT measured by TaqMan allelic discrimination, and by the relative fractions of urinary inorganic arsenic metabolites. Telomere length and mtDNAcn were determined in peripheral blood leukocytes by quantitative PCR, and urinary 8-oxo-dG and 4-HNE-MA by LC-MS/MS. RESULTS: U-As and B-As were associated with longer telomeres and higher mtDNAcn, particularly in women with a less efficient arsenic metabolism. Urinary 8-oxo-dG and 4-HNE-MA were positively associated with U-As, but only 4-HNE-MA was associated with B-As. Arsenic metabolism efficiency did not have a clear effect on the concentrations of either of these biomarkers. CONCLUSION: Bolivian women showed indications of arsenic toxicity, measured by four different biomarkers. Telomere length, mtDNAcn, and 4-HNE-MA were positively associated with both U-As and B-As. The association of arsenic exposure with telomere length and mtDNAcn was only present in Bolivian women with a less efficient metabolism. These findings call for additional efforts to evaluate and reduce arsenic exposure in Bolivia.

In vitro cytotoxicity and genotoxicity of single and combined pesticides used by Bolivian farmers.

We previously showed that farmers in Bolivia are exposed to many pesticides, some at elevated levels, and that this was associated with increased risk of genetic damage. To improve the understanding of possible mixture effects, the cytotoxicity and genotoxicity of pesticides were studied in vitro using human liver HepG2 cells. The studied pesticides were 2,4-D, chlorpyrifos, cypermethrin, glyphosate, methamidophos, paraquat, profenofos, and tebuconazole. Three mixtures (U1, U2, and U3) were based on profiles of urinary pesticide metabolites and one mixture on the most frequently used pesticides (S1). The results showed that paraquat and methamidophos were the most cytotoxic pesticides (EC50 ≤0.3 mM). Paraquat, chlorpyrifos, tebuconazole, and the U1, U2, and U3 mixtures, which contained a large proportion of either chlorpyrifos or tebuconazole, significantly increased intracellular ROS levels. Most pesticides activated DNA damage signaling through proteins Chk1 and H2AX. Strongest responses were elicited by paraquat, profenofos, chlorpyrifos, cypermethrin, and the S1 mixture, which contained 25% paraquat. Comet assay revealed significant increases of DNA damage in response to paraquat, cypermethrin, and U2 and S1 mixtures, which contained high levels of cypermethrin and paraquat, respectively. In summary, we showed that the tested pesticides, alone or in mixtures, in general induced oxidative stress and that most pesticides, and especially paraquat and cypermethrin, were genotoxic in HepG2 cells. We could also show that mixtures dominated by these two pesticides displayed a marked genotoxic potency, which agreed with our previous population studies.

Arsenic Exposure and Cancer-Related Proteins in Urine of Indigenous Bolivian Women.

Indigenous people living in the Bolivian Andes are exposed through their drinking water to inorganic arsenic, a potent carcinogen. However, the health consequences of arsenic exposure in this region are unknown. The aim of this study was to evaluate associations between arsenic exposure and changes in cancer-related proteins in indigenous women (n = 176) from communities around the Andean Lake Poopó, Bolivia. Arsenic exposure was assessed in whole blood (B-As) and urine (as the sum of arsenic metabolites, U-As) by inductively coupled plasma-mass spectrometry (ICP-MS). Cancer-related proteins (N = 92) were measured in urine using the proximity extension assay. The median B-As concentration was 2.1 (range 0.60-9.1) ng/g, and U-As concentration was 67 (12-399) µg/L. Using linear regression models adjusted for age, urinary osmolality, and urinary leukocytes, we identified associations between B-As and four putative cancer-related proteins: FASLG, SEZ6L, LYPD3, and TFPI2. Increasing B-As concentrations were associated with lower protein expression of SEZ6L, LYPD3, and TFPI2, and with higher expression of FASLG in urine (no association was statistically significant after correcting for multiple comparisons). The associations were similar across groups with different arsenic metabolism efficiency, a susceptibility factor for arsenic toxicity. In conclusion, arsenic exposure in this region was associated with changes in the expression of some cancer-related proteins in urine. Future research is warranted to understand if these proteins could serve as valid biomarkers for arsenic-related toxicity.

Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers.

The use of pesticides has increased during the past decades, also increasing the risk of exposure to toxic pesticides that can cause detrimental health effects in the future. This is of special concern among farmers in low-to-middle-income countries that may lack proper training in the safe use of these chemicals. To assess the situation in Bolivia a cross-sectional study in three agricultural communities was performed (n = 297). Handling, use of personal protective equipment (PPE) and pesticide exposure were assessed by a questionnaire and measurements of urinary pesticide metabolites (UPMs). Results showed that methamidophos (65%) and paraquat (52%) were the most commonly used pesticides and that 75% of the farmers combined several pesticides while spraying. Notably, only 17% of the farmers used recommended PPEs while 84% reported to have experienced symptoms of acute pesticide poisoning after spraying. UPM measurements indicated high levels of exposure to chlorpyrifos, pyrethroids and 2,4D and that men generally were more highly exposed compared to women. Our study demonstrates that farmers who are better at following recommendations for pesticide handling and use of PPE had a significantly lower risk of having high UPM levels of most measured pesticides. Our results thus confirm the need of proper training of farmers in low-to-middle-income countries in proper protection and pesticide handling in order to reduce exposure levels and health problems.

Correction to: Pesticide exposure among Bolivian farmers: associations between worker protection and exposure biomarkers.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.In the original Article, co-author Ulla Stenius' surname was misspelled as Ulla Steinus. This has been corrected in the PDF, HTML and XML versions of this Article.

Increased levels of genotoxic damage in a Bolivian agricultural population exposed to mixtures of pesticides.

During the past decades, farmers in low to middle-income countries have increased their use of pesticides, and thereby the risk of being exposed to potentially genotoxic chemicals that can cause adverse health effects. Here, the aim was to investigate the correlation between exposure to pesticides and genotoxic damage in a Bolivian agricultural population. Genotoxic effects were assessed in peripheral blood samples by comet and micronucleus (MN) assays, and exposure levels by measurements of 10 urinary pesticide metabolites. Genetic susceptibility was assessed by determination of null frequency of GSTM1 and GSTT1 genotypes. The results showed higher MN frequency in women and farmers active ≥8 years compared to their counterpart (P < 0.05). In addition, age, GST genotype, alcohol consumption, and type of water source influenced levels of genotoxic damage. Individuals with high exposure to tebuconazole, 2,4-D, or cyfluthrin displayed increased levels of genotoxic damage (P < 0.05-0.001). Logistic regression was conducted to evaluate associations between pesticide exposure and risk of genotoxic damage. After adjustment for confounders, a significant increased risk of DNA strand breaks was found for high exposure to 2,4-D, odds ratio (OR) = 1.99 (P < 0.05). In contrast, high exposure to pyrethroids was associated with a reduced risk of DNA strand breaks, OR = 0.49 (P < 0.05). It was also found that high exposure to certain mixtures of pesticides (containing mainly 2,4-D or cyfluthrin) was significantly associated with increased level and risk of genotoxic damage (P < 0.05). In conclusion, our data show that high exposure levels to some pesticides is associated with an increased risk of genotoxic damage among Bolivian farmers, suggesting that their use should be better controlled or limited.

Elevated arsenic exposure and efficient arsenic metabolism in indigenous women around Lake Poopó, Bolivia.

Elevated concentrations of inorganic arsenic, one of the most potent environmental toxicants and carcinogens, have been detected in well water around Lake Poopó, Bolivia. This study aimed to assess human exposure to arsenic in villages around Lake Poopó, and also to elucidate whether the metabolism and detoxification of arsenic in this population is as efficient as previously indicated in other Andean areas. We recruited 201 women from 10 villages around Lake Poopó. Arsenic exposure was determined as the sum concentration of arsenic metabolites (inorganic arsenic; monomethylarsonic acid, MMA; and dimethylarsinic acid, DMA) in urine (U-As), measured by HPLC-HG-ICP-MS. Efficiency of arsenic metabolism was assessed by the relative fractions of the urinary metabolites. The women had a wide variation in U-As (range 12-407 µg/L, median 65 µg/L) and a markedly efficient metabolism of arsenic with low %MMA (median 7.7%, range: 2.2-18%) and high %DMA (80%, range: 54-91%) in urine. In multivariable-adjusted linear regression models, ethnicity (Aymara-Quechua vs. Uru), body weight, fish consumption and tobacco smoking were associated with urinary arsenic metabolite fractions. On average, the Uru women had 2.5 lower % (percentage unit) iAs, 2.2 lower %MMA and 4.7 higher %DMA compared with the Aymara-Quechua women. Our study identified several factors that may predict these women's arsenic methylation capacity, particularly ethnicity. Further studies should focus on mechanisms underlying these differences in arsenic metabolism efficiency, and its importance for the risk of arsenic-related health effects.

Evaluación de riesgo genotóxico por exposición laboral al betún en lustracalzados. La Paz-Bolivia / Evaluation of genotoxic risk due to shoe polish exposurein shoeshine boys. La Paz-Bolivia

OBJETIVO: Evaluar el riesgo genotóxico en los lustracalzados expuestos laboralmente al betún y sus componentes. MATERIAL Y MÉTODOS: Estudio de casos-controles y autocontroles. Se estudiaron 53 lustracalzados y 24 controles. Se determinó el daño genotóxico mediante la técnica de micronúcleos y otras alteraciones metanucleadas en mucosa bucal. RESULTADOS: Las edades promedio del grupo de expuestos y controles fue de 35.0±8.8 y 27.8±1.5 respectivamente. El grupo de expuestos estuvo conformado varones (83%) y mujeres (17%), con un promedio de años de trabajo de 13.4±7.6, de los cuales la mayoría no usa medidas de protección laboral (73.6%). No se observó diferencias significativas en la frecuencia de alteraciones metanucleadas entre el grupo de expuesto y controles: binucleadas (BN) (p=0.273), broken egg (BE) (p=0.635), carriorexis (CR) (p=0.677), cariolisis (CL) (p=0.770), índice de reparación celular (p=0.201). El análisis de asociación entre exposición y genotoxicidad demostró que el uso del betún no es un factor de riesgo. La evaluación pre y post exposición al betún del grupo de lustracalzados no obtuvo diferencias significativas luego del periodo ventana para BN (p=0.804), BE (p=1.274), CR (p=0.503), CL (p= 1.000) e IR (p=0.424). CONCLUSIÓN: El uso del betún en la población estudiada, no es un factor de riesgo genotóxico. Sin embargo, es necesario continuar estudios de cohorte con una población más numerosa.

OBJECTIVE: To asses the genotoxic risk in shoeshine boys who are constantly exposed to shoe polish and its components. MATERIAL AND METHODS: The study was cross-sectional (exposed and controls) and of cross over trials. It was studied 53 shoe shiners (exposed group) and 24 controls. The buccal cytome technique was applied on children for determining genotoxic damage. RESULTS: The average age of the exposed group and controls was 35.0 ± 8.8 and 27.8 ± 1.5 respectively. The exposed group consisted males (83%) and women (17%), with an average of 13.4 years of work ± 7.6, most of which do not use labor protection measures (73.6%). No significant differences were observed in frequency of metanucleadas alterations from the group of exposed and controls: binucleate (BN) (p = 0.273), broken egg (BE) (p = 0.635), karyorrhexis (KR) (p = 0.677), karyolysis (KL) (p = 0.770), cellular repair rate (RR) (p = 0.201). The analysis of association between exposure and genotoxicity showed that the use of shoe polish and its components is not a risk factor. The assessment pre and post-exposure to shoe polish in the exposed group showed no significant differences after the window period for BN (p = 0.804), BE (p = 1.274), CR (p = 0.503), CL (p = 1.000) and RR (p = 0.424). CONCLUSION: The use of shoe polish by shoeshine boy population is not a genotoxic risk factor. However it is necessary to continue cohort studies with a larger population.

Genetic profiling of Bolivian population using 15 STR markers of forensic importance.

Allele frequencies for the 13 CODIS markers plus D2S1358 and D19S433 loci were estimated in a sample of 148 unrelated individuals from Bolivia and parameters of forensic interest were calculated. Further, the STR data were analyzed using a distance-based method to assess the genetic relationships of this population with other ones living in Argentina, Brazil, Costa Rica, Mexico, Peru, Venezuela and three autochthonous populations living in the Beni Department of Bolivia (Quechua, Aymara and Beni population).

Genetic Alterations in Pesticide Exposed Bolivian Farmers: An evaluation by analysis of chromosomal aberrations and the comet assay.

BACKGROUND: Pesticides are of concern in Bolivia because of increasing use. Frequent intoxications have been demonstrated due to use of very toxic pesticides, insufficient control of distribution and sale and little knowledge among farmers of protective measures and hygienic procedures. METHOD: Questionnaires were applied and blood tests taken from 81 volunteers from La Paz County, of whom 48 were pesticide exposed farmers and 33 non-exposed controls. Sixty males and 21 females participated with a mean age of 37.3 years (range 17-76). Data of exposure and possible genetic damage were collected and evaluated by well known statistical methods, controlling for relevant confounders. To measure genetic damage chromosomal aberrations and the comet assay analysis were performed. RESULTS: Pesticide exposed farmers had a higher degree of genetic damage compared to the control group. The number of chromosomal aberrations increased with the intensity of pesticide exposure. Females had a lower number of chromosomal aberrations than males, and people living at altitudes above 2500 metres seemed to exhibit more DNA damage measured by the comet assay. CONCLUSIONS: Bolivian farmers showed signs of genotoxic damage, probably related to exposure to pesticides. Due to the potentially negative long term health effects of genetic damage on reproduction and the development of cancer, preventive measures are recommended. Effective control with imports and sales, banning of the most toxic pesticides, education and information are possible measures, which could help preventing the negative effects of pesticides on human health and the environment.

Evaluación de riesgo genotóxico: biomonitorización de trabajadores agrícolas de Caranavi, Guanay, Palca y Mecapaca, expuestos a plaguicidas / Assestement of genotoxic risk biomonitoring of farm workers exposed to pesticides in Caranavi, Guanay, Palca and Mecapaca

Objetivo- Detectar los efectos citotóxicos y genotóxicos en trabajadores agrícolas, mediante estudios de biomonitoreo genético. Diseño. Casos y controles. Participantes- Trabajadores agrícolas de Caranavi, Guanay, Mecapaca y Palca del Departamento de La Paz. Lugar.- Localidades de Caranavi, Guanay, Mecapaca y Palca. Unidad genética Toxicológica, Instituto de Genética. Material y Métodos. Se aplicó cuestionario a 259 trabajadores agrícolas. Se evaluó el efecto genotóxico en linfocitos de sangre heparinizada, a travéz de la frecuencia de intercambios entre Cromáties Hermanas (ICH), el índice de proliferación celular (PRI), el tanto por ciento de células con alta frecuencia de intercambios (por ciento HFC), frecuencia de micronúcleos en células binucleadas (MNBN), el índice de división nuclear (IDN), la presencia de aberraciones cromósonicas estructurales (AC), y parámetros de la prueba cometa, como DNA de la cola, DNA de la cabeza, longitud de la cola y longitud del cometa, el momento de la cola, y momento Olive.

Objective To detect the cytotoxic and genotoxic effects in farm workers, by means of genetic biomonitoring studies. Design Cases and controls Participants Farm workers from Caranavi, Guanay, Palca and Mecapaca Place Towns of Caranavi, Guanay, P alca and Mecapaca, Genetic Toxicology unit. Genetic Institute. Material and methodsQuestionnaires to 257 agricultural workers were applied genotoxic effect was evaluated in lymphocytes from heparinized blood, through analysis of sister chromatid Exchange (SCE), cells with a high frecuency of SCE (HFC), proliferation rate index (PRI) the micronucleus (MN) assay, nuclear division index (NDI), chromosomal aberrations (CA) and comet assay parameters like DNA tail, DNA head, tail length comet length, tail moment and Olive moment. Results The frequency of SCE, MN/BN and CA was significantly increased (p<0.05) in cases vs. control group. Likewise, the parameters of Tail DNA, DNA head...

Evaluación de riesgo genotóxico: biomonitorización de trabajadores agrícolas de Caranavi, Guanay, Palca y Mecapaca, expuestos a plaguicidas / Assessment of genoptoxic risk biomonitoring of farm workers exposed to pesticides in Caranavi, Guanay, Palca and Mecapaca

OBJETIVO: detectar los efectos citotóxicos y genotóxicos en trabajadores agrícolas, mediante estudios de biomonitoreo genético. DISEÑO: casos y controles Participantes Trabajadores agrícolas de Caranavi, Guanay, Mecapaca y Palca del Departamento de La Paz Lugar Localidades de Caranavi, Guanay, Palca y Mecapaca. Unidad de Genética, toxicológica Instituto de Genética MATERIAL Y MÉTODOS: se aplicó cuestionario a 259 trabajadores agrícolas. Se evaluó el efecto genotóxico en linfocitos de sangre heparinizada, a través de la frecuencia de Intercambios entre Cromátides Hermanas (ICH), el Índice de Proliferación Celular (PRI), el % de células con alta frecuencia de intercambios (%HFC), frecuencia de micronúcleos en células binucleadas (MNBN), el índice de división nuclear (IDN), la presencia de aberraciones cromosómicas estructurales (AC), y parámetros de la prueba del cometa, como DNA de la cola, DNA de la cabeza, longitud de la cola, longitud del cometa, el momento de la cola y momento Olive. RESULTADOS: Los casos presentaron un aumento estadísticamente significativo (p<0.05) en la frecuencia de ICH, MN/BN y aberraciones cromosómicas, en relación a los controles. Así mismo, los parámetros de DNA de la cola, DNA de la cabeza, longitud de la cola, longitud del cometa, el momento de la cola y momento Olive, mostraron un aumento en relación a los controles, (p<0.05). Los valores promedio (± ES) de los parámetros del ensayo del cometa, fueron mayores y estadísticamente significativos en los expuestos y RPP's en relación a los no expuestos. En el grupo de RPP´s se observó daño genotóxico en menor proporción pero no significativo en relación a los expuestos, posiblemente por su capacitación en medidas de protección. El análisis divariado entre exposición a plaguicidas y daño genotóxico mostró que las personas expuestas a plaguicidas tienen 1.49 veces más probabilidad de sufrir daño genotóxico con un OR de 2.49 (IC 95% 1.48 - 4.20). CONCLUSIÓN: los resultados indican que los trabajadores agrícolas expuestos sin protección ni medidas de seguridad a mezclas de plaguicidas, han experimentado riesgo genotóxico, que fue manifestado con elevada frecuencia de intercambios entre cromátides hermanas, micronúcleos, aberraciones cromosómicas y parámetros del cometa, en linfocitos de sangre periférica. Así mismo, la presencia de aberraciones cromosómicas, que son las que determinan la asociación con efecto carcinogénico, muestra que los trabajadores agrícolas expuestos a plaguicidas tienen mayor probabilidad de que las mutaciones encontradas al momento del estudio, puedan volverse irreversibles por la saturación de los sistemas de reparación del DNA y en el futuro desarrollar diversos tipos de cáncer. Estos hallazgos son indicativos de la necesidad de realizar biomonitorización permanente de los agricultores ocupacionalmente expuestos a varias mezclas de plaguicidas, utilizando una batería de pruebas de genotoxicidad. Por otra parte, ilustra la necesidad de implementar pautas generales para minimizar o prevenir la exposición.

OBJECTIVE: to detect the cytotoxic and genotoxic effects in farm workers, by means of genetic biomonitoring studies. Design Cases and controls Participants Farm workers from Caranavi, Guanay, Palca and Mecapaca Place Towns of Caranavi, Guanay, Palca and Mecapaca, Genetic Toxicology unit. Genetic Institute. MATERIAL AND METHODS: Questionnaires to 257 agricultural workers were applied genotoxic effect was evaluated in lymphocytes from heparinized blood, through analysis of sister chromatid Exchange (SCE), cells with a high frecuency of SCE (HFC), proliferation rate index (PRI) the micronucleus (MN) assay, nuclear division index (NDI), chromosomal aberrations (CA) and comet assay parameters like DNA tail, DNA head, tail length comet length, tail moment and Olive moment. RESULTS: the frequency of SCE, MN/BN and CA was significantly increased (p<0.05) in cases vs. control group. Likewise, the parameters of Tail DNA, DNA head , tail length, comet length, tail moment and Olive moment, showed increased values in relation to controls (p<0.05). Averages of comet parameters were significantly higher in exposed and RPP's group than in un exposed group. RPP`s groups showed minor DNA damage but not as significant as exposed group, possibly due to their training in protective measures. The bivariated analysis between pesticides exposure and genotoxic damage showed that the people exposed to pesticides have 1.49 times more probability of suffering genotoxic damage with OR 2.49 (IC 95% 1.48 - 4.20). CONCLUSIONS: the results indicate that the farm workers exposed to mixture of pesticides without protection and safety measures, are at genotoxic risk hazard , with high frequency of sister chromatid exchange, micronuclei, chromosomal aberrations and parameters of the comet assay in lymphocytes of peripheral blood. Also, the presence of chromosomal aberrations, which are those that determine the association with carcinogenic effect, shows that the farm workers exposed to pesticides have greater probability that the mutations found at the time of the study, can become irreversible by saturation of the DNA repair systems and in the future develop diverse types of cancer. These findings are indicative of the necessity to do permanent biomonitoring of the farmers occupationally exposed to several mixtures of pesticides, using a battery of genotoxicity tests. On the other hand, it illustrates the necessity to implement general guidelines to diminish or to prevent the exposure.

Aspectos éticos y bioéticos de la reproducción asistida y manipulación genética en Bolivia / Aspects ethics and bioethics of the reproduction attende and manipulation genetic in Bolivia

Los modernos avances y descubrimientos científicos y tecnológicos, y en especial en los campos de la Biomedicina y la Biotecnología, han posibilitado, entre otros, el desarrollo y utilización de técnicas de reproducción alternativas a la esterilidad de la pareja humana, generalmente conocidas como Técnicas de Reproducción Asistida o Artificial, algunas de ellas imaginables hasta hace algún tiempo. De ellas, la Inseminación Artificial (IA) con semen del marido o de la pareja (IAC) o con semen de donante (IAD), se viene realizando desde hace varios años. La Fecundación In Vitro (FIV) con transferencia de embriones (TE), de mayor complejidad técnica, se dio a conocer universalmente en 1978 con el nacimiento de Louise Brown, en el Reino Unido, mientras que en nuestro país, el primero de los hoy ya varios nacimientos por esta técnica tuvo lugar en la ciudad de Santa Cruz el año 1993. Actualmente ya se están aplicando en nuestro medio las técnicas de micromanipulación de gametos, como la Inseminación Intracitoplasmática de espermatozoides (ICSI) que consiste en la inyección de un solo espermatozoide directamente dentro del citoplasma del óvulo, tecnología altamente sofisticada y costosa

Programa de la catedra de bioquimica y biologia molecular

CONTENIDO: Guia de practicas; soluciones I; soluciones II; equilibrio acido base, potencial de hidrogeniones; membrana celular I; radicales libres; espectofotometria, metabolismo de hidratos de carbono; bilirrubinas; cinetica enzimatica I; cinetica enzimatica II, ciclo celular y apoptosis; acido desoixribonucleico-DNA; acido desoixribonucleico-DNA; extraccion del DNA; acido ribonucleico-RNA; señales de transcripcion; fundamentos de tecnicas de biologia molecular