Recent Photosensitizer Developments, Delivery Strategies and Combination-based Approaches for Photodynamic Therapy†.

Photodynamic therapy of cancer (PDT) is a therapeutic technique, minimally invasive, which is currently used to treat cancerous lesions and tumors that have been in the spotlight for its potential over the recent decades. Nonetheless, PDT still needs further development to become a first-option treatment for patients. This review compiles recent progress in several aspects of the current research in the constantly growing area of PDT to overcome the main challenges as an attempt to serve as a guide and reference for newcomers into this research area. This review has been prepared to highlight the use of chemical modifications on photosensitizers to improve their solubility, photostability, selectivity and phototoxicity. Additionally, the use of liposomes and cavitands as drug delivery systems to aid in the biodistribution and bioaccumulation of photosensitizers is presented. Also, the combination of PDT with chemotherapy or immunotherapy as an option to boost and improve treatment outcomes is discussed. Finally, the inhibition of antioxidant enzymes as a strategy for a synergistic effect to ameliorate the performance of the photosensitizers in PDT is presented as an alternative for future researchers.

Cassava Frogskin Disease: Current Knowledge on a Re-Emerging Disease in the Americas.

Cassava frogskin disease (CFSD) is a graft-transmissible disease of cassava reported for the first time in the 1970s, in Colombia. The disease is characterized by the formation of longitudinal lip-like fissures on the peel of the cassava storage roots and a progressive reduction in fresh weight and starch content. Since its first report, different pathogens have been identified in CFSD-affected plants and improved sequencing technologies have unraveled complex mixed infections building up in plants with severe root symptoms. The re-emergence of the disease in Colombia during 2019-2020 is again threatening the food security of low-income farmers and the growing local cassava starch industry. Here, we review some results obtained over several years of CFSD pathology research at CIAT, and provide insights on the biology of the disease coming from works on symptoms' characterization, associated pathogens, means of transmission, carbohydrate accumulation, and management. We expect this work will contribute to a better understanding of the disease, which will reflect on lowering its impact in the Americas and minimize the risk of its spread elsewhere.

Health risk assessment of gaseous elemental mercury (GEM) in Mexico City.

Emissions of gaseous elemental mercury (GEM or Hg0) from different sources in urban areas are important subjects for environmental investigations. In this study, atmospheric Hg measurements were conducted to investigate air pollution in the urban environment by carrying out several mobile surveys in Mexico City. This work presents atmospheric concentrations of GEM in terms of diurnal variation trends and comparisons with criteria for pollutant concentrations such as CO, SO2, NO2, PM2.5, and PM10. The concentration of GEM was measured during the pre-rainy period by using a high-resolution active air sampler, the Lumex RA 915 M mercury analyzer. In comparison with those for other cities worldwide, the GEM concentrations were similar or slightly elevated, and they ranged from 0.20 to 30.23 ng m-3. However, the GEM concentration was significantly lower than those in contaminated areas, such as fluorescent lamp factory locations and gold mining zones. The GEM concentrations recorded in Mexico City did not exceed the WHO atmospheric limit of 200 ng m-3. We performed statistical correlation analysis which suggests equivalent sources between Hg and other atmospheric pollutants, mainly NO2 and SO2, emitted from urban combustion and industrial plants. The atmospheric Hg emissions are basically controlled by sunlight radiation, as well as having a direct relationship with meteorological parameters. The area of the city studied herein is characterized by high traffic density, cement production, and municipal solid waste (MSW) treatment, which constantly release GEM into the atmosphere. In this study, we included the simulation with the HYSPLIT dispersion model from three potential areas of GEM release. Emissions from industrial corridors and volcanic plumes localized outside the urban area contribute to the pollution of Mexico City and mainly affect the northern area during specific periods and climate conditions. Using the USEPA model, we assessed the human health risk resulting from exposure to inhaled GEM among residents of Mexico City. The results of the health risk assessment indicated no significant noncarcinogenic risk (hazard quotient (HQ) < 1) or consequent adverse effects for children and adults living in the sampling area over the study period. GEM emissions inventory data is necessary to improve our knowledge about the Hg contribution and effect in urban megacity areas with the objective to develop public safe policy and implementing the Minamata Convention.

Biomonitoring of airborne trace elements using transplanted lichens around a paper industry (Morelia, Mexico).

The deposition of trace elements around a pulp and paper industry in Morelia, Mexico, was evaluated using two lichen species as biomonitors. Samples of the foliose lichen Flavopunctelia praesignis and the fruticose lichen Usnea ceratina were collected in two remote areas and transplanted at different distances and directions from the pollution source. Lichen samples were exposed for 4 months (1) around the industrial area and (2) in their native habitats (control sites). We investigated the bioaccumulation of 11 trace elements in lichen thalli, and we compared the response of the two lichen species. To identify possible common sources, we evaluated the relationships between trace elements by correlations and cluster analyses. Our results showed that Cd was a good tracer for air pollution from the pulp and paper mills. In samples of Usnea ceratina exposed around the industrial area, Cd was significantly higher than in the remote area. Within the study area, trace element contents increase with the distance from the source, and they showed high depositions in the direction of prevailing winds. Moreover, we were able to detect groups of elements with similar behavior and common origins. Our results indicated that Flavopunctelia praesignis showed a higher capacity to accumulate trace elements than Usnea ceratina.

Cytotoxic and Pro-Inflammatory Effects of Miniscrews Subject to Corrosion in Oral Cell Cultures.

Cytotoxic and pro-inflammatory effects of mini-screws subject to corrosion in oral cells culture. To analysis the products of corrosion of three different commercial orthodontic mini-screws and evaluate the cytotoxicity and pro-inflammatory effects in culture with human gingival fibroblast cells (HGFs) and human osteoblast-like bone surface cells (HBCs). An experimental in vitro study was carried out with 3 different type of mini-screws: Vector-Tas®, Forestadent ORTHOEasy®, Bio-Ray® (n = 30/gp). The samples were subjected to accelerated corrosion for 24, 48, 72 and 96 hours, which were observed with a stereomicroscope and scanning electron microscope. The corrosion products were analyzed by inductively coupled plasma with mass spectrometry. The direct and indirect cytotoxicity was tested in culture with HGFs and HBCs, cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The pro-inflammatory effect was determined by the expression of prostaglandin E2 (PGE2) with the ELISA test. The data were subjected to Shapiro-Wilks normality tests, paired t-tests and Tukey's post hoc ANOVA. The mini-screw topography showed significant morphological changes after corrosion. The main ions after corrosion were Al, Ti, and Fe. Corrosion products by direct and indirect contact with cells slightly reduced (P < 0.05) cell viability, considered non-cytotoxic. The expression of PGE2 was not increased by the presence of the corrosion products even in a previous pro-inflammatory state. The corrosion products were not cytotoxic and did not induce a pro-inflammatory state in culture with HGFs and HBCs.

Gaseous Elemental Mercury (GEM) in the Mexico City Metropolitan Area.

This paper presents atmospheric gaseous elemental mercury (GEM) data recorded during two short-term monitoring surveys in the Mexico City Metropolitan Area (MCMA) at 12th May 2019 and at 22nd May 2020, during conditions of low and high human activity respectively. Results, although they are limited, can be considered as the representative range of exposure to GEM of the inhabitants of MCMA; differences in results reveal the impact of human activities on GEM background levels (2.53 and 3.76 ng m-3, respectively). GEM concentrations and their spatial distribution does not allow for the identification of important industrial sources and do not reach intervention pollution levels. The activity of the Popocatépetl volcano is not likely to have an effect on GEM in the MCMA. In spite the evident decrease in GEM concentrations compared with data previously reported, monitoring must be carried out routinely given Mexico's participation in the Minamata Convention on Mercury.

Historical trends of metals concentration in PM10 collected in the Mexico City metropolitan area between 2004 and 2014.

In this work, we report metals concentrations in 80 PM10 samples collected at four sites in the Mexico City Metropolitan Area (MCMA): Tlalnepantla (NE), Xalostoc (NE), Merced (C), and Pedregal (S), during the dry/cold season (October to January) for the 2004-2014 period. Mean PM10 mass concentration (66.1 µg m-3) significantly exceeds the annual mean air quality guidelines recommended by the World Health Organization. The statistical analysis of concentration data and meteorological parameters allows us to recognize the importance of wind intensity speed (Wsp) and wind direction conditions in the enrichment of PM concentrations. The proximity and magnitude of the emitting source is also relevant for PM concentration. Such conditions favored that higher metal concentration was recognized at the north of the studied area. By means principal component analysis (PCA) was difficult to identify the groups of metals associated with specific sources (anthropogenic and geogenic) given the high complexity of the study area and the long period of time evaluated. Metal concentration trend shows an important positive trend for Pt, V and Cr, while PM10, Ni, Cu, Ag and Sb show a trend of moderate increase. In contrast, Pb and Co registered a strong percentage reduction, while Hg, Mn, As and Cd show a slight reduction, probably resulting from the implementation of regulatory measures and influenced by urban changes associated at the north of the studied area. The results of this research provide information that should be considered for evaluating the impact of anthropogenic sources and applying regulatory measures to control emissions.

Metal(loid) exposure on children from a historical metallurgical site.

The data obtained in this study represent a comprehensive assessment of human exposure to metal(loids) enriched in the environment, derived from metallurgical activities in Cedral, a town in North-Central Mexico. A multi-elemental analysis (As, Cd, Cr, Cu, Fe, Mn and Sb) shows high metal(loid) content in environmental media (tailings samples, dust samples and particulate matter < 2.5 µm collected in the urban area). Blood samples from school-age children were collected and analyzed to determine exposure levels. The assessment of the data obtained from this study shows that Sb and Cd are highly enriched elements in the environment of Cedral; their respective levels in the blood samples analyzed are 10.9 and 11.3 times higher than their pediatric reference levels. The statistical analysis indicates a strong relationship between metal(loid)s in blood samples and both dust and PM2.5 samples, which reveal that ingestion and inhalation could represent important exposure routes for metal(loid) intake. Continuous monitoring in the area is paramount to assess the health impact posed by the different routes of exposure. It is also important to implement health education programs to decrease the population's exposure to metal(loid)s and to design urgent remediation measures, to be implemented as soon as possible.

Mercury, Platinum, Antimony and Other Trace Elements in the Atmospheric Environment of the Urban Area of Mexico City: Use of Ficus benjamina as Biomonitor.

The application of Sb, Pt and Hg in the development of new strategic technologies has increased significantly in recent years. This study evaluates the impact of vehicular traffic on the rise in emission of Sb, Pt and Hg in the atmospheric environmen of Mexico City and their correlation to Co, Cr, Cu, Ni, Pb, V and Zn. Ficus benjamina leaves were collected as biomonitor of atmospheric metals deposited in areas exposed to heavy vehicular traffic. High enrichment factor values (metal(loid) concentration/background values) were calculated: 146 (Sb), 52.8 (Pb), 29.7 (Pt) and 25.1 (Cr). Enrichment factors of Ni, Zn, Co, V, Cu and Hg decrease in that order and are < 10. Principal component analysis allows recognize that most of the analyzed metal(loids) are related to traffic sources; Ni and Cr are also attributable to an additional anthropogenic source. No relationship was found relating Pb to vehicular sources.

Developing evidence briefs for policy: a qualitative case study comparing the process of using a guidance-contextualization workbook in Peru and Uganda.

BACKGROUND: Translating research evidence from global guidance into policy can help strengthen health systems. A workbook was developed to support the contextualization of the WHO's 'Optimizing health worker roles to improve maternal and newborn health' (OptimizeMNH) guidance. This study evaluated the use of the workbook for the development of evidence briefs in two countries - Peru and Uganda. Findings surrounding contextual factors, steps in the process and evaluation of the workbook are presented. METHODS: A qualitative embedded case study was used. The case was the process of using the workbook to support the contextualization of global health systems guidance, with local evidence, to develop evidence briefs. Criterion sampling was used to select the countries, participants for interviews and documents included in the study. A template-organizing style and constant comparison were used for data analysis. RESULTS: A total of 19 participant-observation sessions and 8 interviews were conducted, and 50 documents were reviewed. Contextual factors, including the cadres, or groups, of health workers available in each country, the way the problem and its causes were framed, potential policy options to address the problem, and implementation considerations for these policy options, varied substantially between Peru and Uganda. However, many similarities were found in the process of using the workbook. Overall, the workbook was viewed positively and participants in both countries would use it again for other topics. CONCLUSIONS: Organizations that produce global guidance, such as WHO, need to consider institutionalizing the application of the workbook into their guidance development processes to help users at the national/subnational level create actionable and context-relevant policies. Feedback mechanisms also need to be established so that the evidence briefs and health policies arising from global guidance are tracked and the findings coming out of such guideline contextualization processes can be taken into consideration during future guidance development and research priority-setting.

Spatial and temporal distribution of metals in PM2.5 during 2013: assessment of wind patterns to the impacts of geogenic and anthropogenic sources.

The Mexico City Metropolitan Area (MCMA) was the object of a chemical elemental characterization (Ti, V, Cr, Mn, Co, Ni, Cu, Mo, Ag, Cd, Sb, Pb, La, Sm, Ce, and Eu) of PM2.5 collected during 2013 and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Sampling campaigns were carried out at five locations simultaneously-northwest, northeast, center, southwest, and southeast-during dry-warm season (April), rainy season (August), and dry-cold season (November). By means of enrichment factor (EF) and principal component analysis (PCA), it was possible to attribute the analyzed elements to geogenic and anthropogenic sources, as well as to identify a group of elements with mixed provenance sources. The highest concentrations for most metals were found in northwest and northeast, and during dry-warm (DW), confirming the trend observed in PM2.5 samples collected in 2011. Despite similarities between 2011 and 2013, an increase of 17% in PM2.5 mass concentration was observed, mainly attributable to geogenic sources, whereby the importance of wind intensity to the impact of emission sources is highlighted. The effect of wind intensity was revealed, by means of polar plots, as the controlling mechanism for this increase. This allowed us to conclude that high-speed episodes (5 m s-1) were responsible for raising geogenic metal concentrations rather than wind direction.

Atmospheric PM2.5 Mercury in the Metropolitan Area of Mexico City.

In this study, atmospheric mercury concentration in airborne particulate matter with an aerodynamic diameter ≤ 2.5 µm (PM2.5) was analyzed by ICP-MS. Samples were collected in the Mexico City Metropolitan Area (MCMA), during 2013, in five locations, Northwest, Northeast (NE), Central, Southwest and Southeast, along three seasons: dry warm, rainy, and dry cold (DC). It can be observed that NE shows the highest mercury concentration (p < 0.05), where pollution events were identified. The seasonal distribution shows that samples collected during DC present the highest concentration (p < 0.05). These results are in agreement with the distribution of important mercury industrial sources located in the northern urban area as well with the temperature and wind conditions during 2013. The comparison of data obtained in this work with those of similar previous studies clearly indicates a decrease, between 2006 and 2013, of mercury content in PM2.5 collected in MCMA.

Fractionation and mobility of thallium in areas impacted by mining-metallurgical activities: Identification of a water-soluble Tl(I) fraction.

Mining and metallurgy generate residues that may contain thallium (Tl), a highly toxic metal, for which it is currently not feasible to determine its geochemical speciation through X-ray absorption spectroscopy due to a combination of very low contents and the interference of accompanying high arsenic contents. Therefore, fractionation studies in residues and soils are required to analyze the mobility and bioavailability of this metal, which in turn provide information to infer its speciation. For this purpose, in this work a modification of the BCR procedure was applied to residues and contaminated soils from three mining zones of Mexico and two mining zones of Spain, spanning samples with acidic to alkaline pH values. The Tl extraction procedure consisted of the following fractions: (1) water-extractable, (2) easily exchangeable and associated to carbonates, associated to (3) poorly-crystalline and (4) crystalline Fe and Mn oxyhydroxides, and (5) associated to organic matter and sulfides; and finally a residual fraction as associated to refractory primary and other secondary minerals. The extracted contents were analyzed by Inductively-Coupled Plasma with Mass Spectrometry. Surprisingly, water-soluble, in Tl(I) oxidation state, was detected in most areas, regardless of the pH, a fact that has not been reported before in these environments, and alerts to potential health risks not previously identified. Most of the samples from a metallurgy area showed high levels of Tl in non-residual fractions and a strong correlation was obtained between extracted Mn and Tl in the third fraction, suggesting its association to poorly crystalline manganese oxides. In the majority of samples from purely mining environments, most of the Tl was found in the residual fraction, most probably bound to alumino-silicate minerals. The remaining Tl fractions were extracted mainly associated to the reducible mineral fractions, and in one case also in the oxidizable fraction (presumably associated to sulfides). Capsule: Soluble Tl(I) was found in all soil samples contaminated with either mining or metallurgical wastes. Additionally, in those affected by metallurgical wastes a very strong Tl-Mn correlation was found.

Recognition of the importance of geogenic sources in the content of metals in PM2.5 collected in the Mexico City Metropolitan Area.

The study of airborne metals in urban areas is relevant due to their toxic effects on human health and organisms. In this study, we analyzed metals including rare earth elements (REE) in particles smaller than 2.5 µm (PM2.5), collected at five sites around the Mexico City Metropolitan Area (MCMA), during three periods in 2011: April (dry-warm season, DW), August (rainy season, R), and November (dry-cold season, DC). Principal component analysis allowed identifying factors related to geogenic sources and factors related to anthropogenic sources. The recognition of the high impact of geogenic sources in PM2.5 is in agreement with the REE distribution patterns, which show similar behavior as those shown by igneous rocks, confirming the influence of the regional geogenic material. Metals associated to geogenic sources showed higher concentration (p < 0.05) at NE of the MCMA and a significant correlation with prevalent winds. Geogenic metals show similar seasonal distribution, with the highest concentration during DW (p < 0.05), suggesting a possible metal resuspension effect which affects more significantly at lower relative humidity (RH). The metals associated with anthropogenic sources are in agreement with the urban complexity of the area, showing homogenous distribution throughout MCMA (p > 0.05) and no similar seasonal pattern among them. These unexpected results exposed outstanding information regarding the identification of different geogenic sources as the main contributors of metals in the atmospheric environment in the MCMA and highlighted the importance of meteorology in the spatial and seasonal metal patterns.

Diversity of Neopestalotiopsis and Pestalotiopsis spp., Causal Agents of Guava Scab in Colombia.

Common guava (Psidium guajava L.) is a fruit tree of global economic importance. It is grown in Asia, South and Central America, and Hawaii for its exquisite aroma and flavor, and nutritional and medical properties. However, guava production is limited by guava scab, caused by fungi in the Pestalotiopsis genus. Characteristic symptoms of guava scab are corky, ovoid or round lesions on fruit surfaces. These lesions may thicken, affecting the flesh below and reducing fruit quality and commercial value. We characterized 81 isolates isolated from guava scab lesions on guava leaves and fruit in different regions of Colombia, and identified them as Pestalotiopsis and Neopestalotiopsis spp. We analyzed the morphology, pathogenicity, and genetic diversity of the isolates based on the sequences of the internal transcribed spacer, ß-tubulin, and elongation factor genes. Isolates were morphologically, pathogenically, and genetically diverse but the diversity did not correlate with geographical origin, or guava cultivar or tissue from which the isolates were recovered. Selected monosporic isolates included in the multiple-gene analysis were identified as belonging to two genera: Neopestalotiopsis (65 isolates with versicolorous conidia) and Pestalotiopsis (4 isolates with concolorous conidia).

The peroxyl radical-induced oxidation of Escherichia coli FtsZ and its single tryptophan mutant (Y222W) modifies specific side-chains, generates protein cross-links and affects biological function.

FtsZ (filamenting temperature-sensitive mutant Z) is a key protein in bacteria cell division. The wild-type Escherichia coli FtsZ sequence (FtsZwt) contains three tyrosine (Tyr, Y) and sixteen methionine (Met, M) residues. The Tyr at position 222 is a key residue for FtsZ polymerization. Mutation of this residue to tryptophan (Trp, W; mutant Y222W) inhibits GTPase activity resulting in an extended time in the polymerized state compared to FtsZwt. Protein oxidation has been highlighted as a determinant process for bacteria resistance and consequently oxidation of FtsZwt and the Y222W mutant, by peroxyl radicals (ROO•) generated from AAPH (2,2'-azobis(2-methylpropionamidine) dihydrochloride) was studied. The non-oxidized proteins showed differences in their polymerization behavior, with this favored by the presence of Trp at position 222. AAPH-treatment of the proteins inhibited polymerization. Protein integrity studies using SDS-PAGE revealed the presence of both monomers and oligomers (dimers, trimers and high mass material) on oxidation. Western blotting indicated the presence of significant levels of protein carbonyls. Amino acid analysis showed that Tyr, Trp (in the Y222W mutant), and Met were consumed by ROO•. Quantification of the number of moles of amino acid consumed per mole of ROO• shows that most of the initial oxidant can be accounted for at low radical fluxes, with Met being a major target. Western blotting provided evidence for di-tyrosine cross-links in the dimeric and trimeric proteins, confirming that oxidation of Tyr residues, at positions 339 and/or 371, are critical to ROO•-mediated crosslinking of both the FtsZwt and Y222W mutant protein. These findings are in agreement with di-tyrosine, N-formyl kynurenine, and kynurenine quantification assessed by UPLC, and with LC-MS data obtained for AAPH-treated protein samples.

Phenotyping Brachiaria Genotypes to Assess Rhizoctonia Resistance by Comparing Three Inoculum Types.

Rhizoctonia foliar blight, caused by Rhizoctonia solani, is an important disease of Brachiaria spp. in tropical America. Host-plant resistance is an attractive option for disease management. In this study, we evaluated three inoculum types (mycelium-infected agar disc, microdiscs suspensions, and microencapsulated-mycelium suspensions) in order to identify a rapid and accurate method for mass screening of Brachiaria genotypes for resistance to Rhizoctonia spp. in greenhouse trials. Visual damage score, area under the disease progress curve, and percent chlorophyll loss were estimated to determine the most accurate and precise method for evaluating Rhizoctonia resistance. The microencapsulated-mycelium solution (0.75 g/ml in potato dextrose broth sprayed on plants 30 days after planting) caused greater foliar damage than the other inoculum types and allowed effective discrimination between resistant and susceptible genotypes. The effectiveness of spray-applied, microencapsulated-mycelium was further corroborated by the evaluation of 350 genotypes not previously selected for resistance to Rhizoctonia spp., which varied significantly in their reaction to R. solani. The microencapsulated-mycelium methodology has several advantages over existing methods, including its high-throughput capacity, efficient use of time and space, ease of quantification of inoculum, and consistent results over replicate trials. This methodology could be applied to assess resistance to Rhizoctonia spp. in other crops.

Anaplasma platys Immunoblot Test Using Major Surface Antigens.

Anaplasma platys is an uncultivable tick-borne obligatory intracellular bacterium, which is known to infect platelets of dogs. A. platys causes infectious canine cyclic thrombocytopenia in subtropical and tropical regions throughout the world. Several cases of human infection with A. platys infection have also been reported. However, seroprevalence of A. platys exposure and infection has not been determined in most of the regions, in part, due to lack of a simple and reliable assay method. Furthermore, A. platys antigens recognized by dogs are unknown. We previously sequenced gene encoding A. platys major outer membrane proteins P44 and Omp-1X. In the present study, we obtained purified recombinant A. platys P44 and Omp-1X proteins, and using them as antigens in immunoblotting examined seroreactivity in dogs. Of 34 specimens from Venezuela where A. platys infection was previously reported, 25 specimens (73.5%) reacted to rAplP44 and/or rAplOMP-1X. Neither Anaplasma phagocytophilum-seropositive (N = 10) nor A. phagocytophilum-seronegative canine specimens (N = 10) from the geographic regions where A. platys infection has never been reported, reacted rAplP44 or rAplOMP-1X. The result indicates a high A. platys seroprevalence rate in tested dogs from Venezuela and suggests that the immunoblot analysis based on recombinant A. platys major outer membrane proteins can provide a simple and defined tool to enlighten the prevalence of A. platys infection.

Intervenciones para optimizar la oferta de métodos modernos de planificación familiar en la región tropical de Loreto, Perú / Interventions to Optimize the Modern Family Planning Method Supply in the Loreto Tropical Region, Peru / Intervenções para otimizar a oferta a métodos modernos de planejamento familiar na região tropical de Loreto, Peru

El uso de métodos de planificación familiar, principalmente de métodos anticonceptivos modernos -por su mayor eficacia-, está asociado a la disminución de casos de embarazo no deseado, abortos, y a una disminución de las tasas de fecundidad y mortalidad materna, viabilizando así una maternidad voluntaria y saludable. Sin embargo, su uso en el Perú es aún insuficiente, sobre todo en un departamento como Loreto que presenta el mayor porcentaje de demanda insatisfecha de planificación familiar a nivel nacional (14,2%) y altas tasas de fecundidad (3,8). Este es un problema importante para la salud sexual y reproductiva, y en general para la salud pública, ya que tiene repercusiones socioeconómicas relevantes. En este artículo se realiza una revisión narrativa de la evidencia disponible sobre tres intervenciones destinadas a incrementar la oferta de los métodos anticonceptivos modernos, su contextualización local y las consideraciones para su potencial implementación local.

The use of family planning methods, mainly modern contraceptive methods - due to their higher effectiveness - is associated with a reduction in the number of unplanned pregnancy and abortion cases, and also with a reduction in the maternal fertility and morbidity rates, leading to a greater visibility of a voluntary and healthy maternity. However, the use of these methods is still insufficient in Peru, especially in states such as Loreto, which has the highest unfulfilled demand rate for family planning methods on the national level (14.2%) and high fertility rates (3.8). This is an important issue for sexual and reproductive health and, in general terms, for public health, as it has relevant social and economic results. In this article, we carry out a narrative review of the available evidence on three interventions aimed to increase the supply of modern contraceptive methods, their local contextualization, and considerations for potential local implementation.

O uso de métodos de planejamento familiar, principalmente de métodos contraceptivos modernos -pela sua maior eficácia-, é associado à diminuição de casos de gravidez não desejada, abortos, e diminuição das taxas de fecundidade e mortalidade materna, possibilitando assim uma maternidade voluntaria e saudável. No entanto, o uso no Peru ainda é insuficiente, sobretudo em um departamento como Loreto que apresenta a maior porcentagem de demanda insatisfeita de planejamento familiar no nível nacional (14,2%) e altas taxas de fecundidade (3,8). Este é um problema importante de saúde sexual e reprodutiva e em geral para a saúde pública, pois tem repercussões socioeconómicas relevantes. Neste artigo realiza-se uma revisão narrativa da evidencia disponível sobre três intervenções destinadas a incrementar a oferta dos métodos anticoncepcionais modernos, sua contextualização local e as considerações para sua potencial implementação local.

Increase in platinum group elements in Mexico City as revealed from growth rings of Taxodium mucronatum ten.

Tree rings may be used as indicators of contamination events providing information on the chronology and the elemental composition of the contamination. In this framework, we report PGEs enrichment in growth rings of Taxodium mucronatum ten for trees growing in the central area of Mexico City as compared to trees growing in a non-urban environment. Concentrations of PGE were determined by ICP-MS analysis on microwave-digested tree rings. The element found in higher concentrations was Pd (1.13-87.98 µg kg(-1)), followed by Rh (0.28-36.81 µg kg(-1)) and Pt (0.106-7.21 µg kg(-1)). The concentration trends of PGEs in the tree-ring sequences from the urban area presented significant correlation values when comparing between trees (r between 0.618 and 0.98, P < 0.025) and between elements within individual trees (r between 0.76 and 0.994, P < 0.01). Furthermore, a clear increase was observed for rings after 1997, with enrichment of up to 60 times the mean concentration found for the sequence from the non-urban area and up to 40 times the mean concentration for the pre-1991 period in the urban trees. These results also demonstrate the feasibility of applying T. mucronatum ten to be used as a bioindicator of the increase in PGE in urban environments.