RESUMEN
In the pursuit of higher food production and economic growth and increasing population, we have often jeopardized natural resources such as soil, water, vegetation, and biodiversity at an alarming rate. In this process, wider adoption of intensive farming practices, namely changes in land use, imbalanced fertilizer application, minimum addition of organic residue/manure, and non-adoption of site-specific conservation measures, has led to declining in soil health and land degradation in an irreversible manner. In addition, increasing use of pesticides, coupled with soil and water pollution, has led the researchers to search for an environmental-friendly and cost-effective alternatives to controlling soil-borne diseases that are difficult to control, and which significantly limit agricultural productivity. Since the 1960s, disease-suppressive soils (DSS) have been identified and studied around the world. Soil disease suppression is the reduction in the incidence of soil-borne diseases even in the presence of a host plant and inoculum in the soil. The disease-suppressive capacity is mainly attributed to diverse microbial communities present in the soil that could act against soil-borne pathogens in multifaceted ways. The beneficial microorganisms employ some specific functions such as antibiosis, parasitism, competition for resources, and predation. However, there has been increasing evidence on the role of soil abiotic factors that largely influence the disease suppression. The intricate interactions of the soil, plant, and environmental components in a disease triangle make this process complex yet crucial to study to reduce disease incidence. Increasing resistance of the pathogen to presently available chemicals has led to the shift from culturable microbes to unexplored and unculturable microbes. Agricultural management practices such as tillage, fertilization, manures, irrigation, and amendment applications significantly alter the soil physicochemical environment and influence the growth and behaviour of antagonistic microbes. Plant factors such as age, type of crop, and root behaviour of the plant could stimulate or limit the diversity and structure of soil microorganisms in the rhizosphere. Further, identification and in-depth of disease-suppressive soils could lead to the discovery of more beneficial microorganisms with novel anti-microbial and plant promoting traits. To date, several microbial species have been isolated and proposed as key contributors in disease suppression, but the complexities as well as the mechanisms of the microbial and abiotic interactions remain elusive for most of the disease-suppressive soils. Thus, this review critically explores disease-suppressive attributes in soils, mechanisms involved, and biotic and abiotic factors affecting DSS and also briefly reviewing soil microbiome for anti-microbial drugs, in fact, a consequence of DSS phenomenon.
RESUMEN
Bihar, India has been in the grip of kala-azar for many years. Its rampant and severe spread has made life miserable in most parts of the state. Such conditions require a comprehensive understanding of this affliction. The numbers coming out of the districts prone to the disease in the north and south Ganges have provided us with several startling revelations, as there are striking uniformities on both sides, including similar vegetation, water storage facilities, house construction and little change in risk factors. The northern areas have been regularly sprayed with DDT since 1977, but eradication of the disease appears to be a distant dream. In 2007 alone, there were as many as 37,738 cases in that region. In contrast, the southern districts of Patna and Nalanda have never had the disease in its epidemic form and endemic disease has been present in only some pockets of the two districts. In those cases, two rounds of spraying with DDT had very positive results, with successful control and no new established foci. In addition, an eleven-year longitudinal study of the man hour density and house index for the vector Phlebotomus argentipes demonstrated that they were quite high in Patna and Nalanda and quite low in north Bihar. Given these facts, an attempt has been made to unravel the role of P. argentipes saliva (salivary gland) in the epidemiology of kala-azar. It was determined that patchy DDT spraying should be avoided for effective control of kala-azar.
Asunto(s)
DDT , Insectos Vectores/crecimiento & desarrollo , Insecticidas , Leishmaniasis Visceral/prevención & control , Phlebotomus/crecimiento & desarrollo , Análisis de Varianza , Animales , Vivienda/clasificación , Vivienda/estadística & datos numéricos , Humanos , Humedad , India/epidemiología , Insectos Vectores/inmunología , Resistencia a los Insecticidas , Leishmaniasis Visceral/epidemiología , Leishmaniasis Visceral/transmisión , Estudios Longitudinales , Control de Mosquitos , Phlebotomus/inmunología , Densidad de Población , Glándulas Salivales/inmunologíaRESUMEN
The treatment of colorectal cancer continues to pose major challenges for oncologists throughout the world. Uracil and tegafur (UFT), as an oral agent, represents a new patient-focused approach to managing a malignancy with few treatment alternatives other than an intravenous fluorouracil (5-FU)-based regimen. The ability of UFT to achieve equivalent clinical outcomes compared with continuous 5-FU infusion, along with its oral formulation and mild toxicity profile, provide a compelling backdrop for fiscal analysis. An economic assessment of therapy attributes and effects would, therefore, be prudent and necessary when deliberating the adoption of this chemotherapy regimen. We developed a pharmacoeconomic model in Brazil and Argentina identifying clinical practices associated with chemotherapy administration and adverse event management practices from a panel of physicians assembled in each country. Practice patterns and clinical events were then evaluated for resource utilisation trends. The perspective of this pharmacoeconomic analysis was that of the healthcare payor. Country-specific charge data were applied to the identified resources to arrive at an average cost per patient receiving a 6-cycle course of 5-FU with either levamisole and/or leucovorin as a modulator vs a modelled oral UFT/leucovorin regimen. As a comparator, the oral UFT/leucovorin regimen was modelled based on the expert panel's input. Adverse events and incidence data were derived from clinical trial data for both agents. Both agents were analysed in the treatment of metastatic disease and as adjuvant therapy. The principal findings of a cost-minimisation analysis in Brazil revealed approximately equivalent treatment costs for both regimens in the adjuvant setting. When analysing the metastatic treatment arm, costs diverged by $R335/per patient ($R = Reals - the currency of Brazil) in favour of a UFT regimen. The profile in Argentina yielded more dramatic differences, with a UFT regimen costing $P782/per patient ($P = Pesos - the currency of Argentina) less than a 5-FU regimen in the adjuvant setting. In the treatment of metastatic disease, a UFT regimen provided $P1188/per patient in savings over a 5-FU regimen. These differences are predominantly driven by the mild toxicity profile of UFT and its corresponding less severe adverse event management practice patterns. In addition, the oral formulation of UFT versus intravenous 5-FU provides for ease of administration, lowering the total cost of care as well as likely impacting on the patient's quality of life. The pharmacoeconomic results suggest that a UFT regimen is a useful and economical alternative to the standard 5-FU regimen in the treatment of colorectal cancer in Brazil and Argentina.
RESUMEN
The escalating role played by managed care organizations in the health-care system is reflected in the increased demand for cost-effectiveness analyses (CEAs) to assess the balance between economic impact and clinical efficacy. For example, the high incidence and costs associated with colorectal cancer in Latin America calls for a comprehensive economic evaluation to ensure appropriate allocation of limited health-care funds. In addition, the current call for a "societal" perspective of such analyses indicates the need for increased consideration of the concerns of both patient and health-care provider. The introduction of oral tegafur and uracil (UFT) provided the opportunity to evaluate the pharmacoeconomic advantage of the new agent compared with the standard fluorouracil (5-FU). Results of this study indicated an economic advantage for oral UFT vs a 5-FU-based regimen in the treatment of colorectal cancer in Brazil and Argentina. It was further noted that the mild toxicity profile of UFT reduced both the number of clinic visits and the need for venipuncture procedures. Noting that oral UFT may have a positive impact on quality of life in addition to its estimated economic benefit, it was concluded that prospective economic research and quality-of-life evaluations are needed to fully assess the pharmacoeconomic impact of oral UFT.