RESUMO
Pollution represents a high risk to plants, animals, and human beings, causing an imbalance and affecting the environment. Soil is considered a universal sink, containing the highest load of environmental pollution. Puchuncaví-Ventanas sector, decreed as a saturated contamination zone in 1993, is considered one of the most affected areas by industrial pollution and belongs to one of the 5 sacrifice zones of Chile. The localities of Puchuncaví and Ventanas have heavy metal pollution levels that exceed up to 99% of the limits allowed by Canadian standards. The objective of this study was to characterize heavy metal tolerance and removal potential of filamentous fungi isolated from polluted soils for their use in decontamination systems and in situ soil improvement. Six fungal strains were selected based on their tolerance and a high capability to accumulate heavy metals, achieving copper bioaccumulation of 84% (Mortierella sp. strain LG01), 49% (Clonostachys sp. strain CQ23) and 48-77.5% (Trichoderma sp. strain LM01A). Trichoderma sp. strain LM01A was able to remove 41% of copper from contaminated soil under ex situ conditions. Some fungal strains belong to beneficial fungal genera, which are used as bioproducts in agriculture. The results of this study highlighted the use of Trichoderma sp. in soils contaminated, which may be of special interest in agriculture due to the large amounts of copper sulfate still applied as a pesticide in Chile and the world.
Assuntos
Metais Pesados , Poluentes do Solo , Humanos , Cobre/análise , Chile , Canadá , Metais Pesados/toxicidade , Metais Pesados/análise , Fungos , Poluição Ambiental , Solo , Poluentes do Solo/toxicidade , Poluentes do Solo/análiseRESUMO
We conducted a retrospective cohort study to evaluate risk factors associated with clinical mastitis in dairy cows in southern Chile between the first milk test after calving to 200 d in milk (DIM). Data from 8,772 cows were collected from June 2017 to November 2019 on 10 dairy farms selected by convenience in southern Chile. Data were analyzed using a multivariable mixed logistic regression using a manual backward selection process with logit link function and farm as a random effect. The dependent variable was clinical mastitis between the first milking sample collected by monthly milk sampling program up to 200 DIM. Days in milk, fat, urea, parity, season, and somatic cell counts were statistically associated with clinical mastitis in the first 200 d in milk. Cows with higher than average milk yield, parity, urea, and somatic cell count were at greater odds of being diagnosed with clinical mastitis compared with their respective referents. In contrast, higher milk fat was associated with lower odds of clinical mastitis. Significant interactions between days in milk with season and parity were observed, where for every 5-d increase in DIM, the odds of clinical mastitis decreased by different proportions depending on the interaction. Identified risk factors for clinical mastitis using first monthly milk sampling data can help dairy farmers in Chile implement herd-level mastitis prevention and control measures.
Assuntos
Mastite Bovina , Animais , Bovinos , Contagem de Células/veterinária , Chile/epidemiologia , Indústria de Laticínios , Fazendas , Feminino , Humanos , Lactação , Mastite Bovina/tratamento farmacológico , Leite , Gravidez , Estudos Retrospectivos , Fatores de Risco , UreiaRESUMO
BACKGROUND: The presence of a family history implies an increased risk for developing colorectal cancer (CRC), and may require a different screening strategy. The aim of this study was to evaluate lesions found during colonoscopies of patients that had a family history of CRC. MATERIAL AND METHODS: A retrospective study was conducted that included consecutive colonoscopies performed on patients with a family history of CRC at a referral center within the period from April 2000 to January 2012. The colonoscopic findings were analyzed in relation to sex, age, and the presence or absence of symptoms. RESULTS: Data from 3,792 colonoscopies were collected. The mean age of the patients was 53.14 years (SD 12.22), and 57.4% were women. Colonoscopy was normal in 71.7% of the cases, with hyperplastic polyps being detected in 7.1%, and adenomatous polyps in 19.8% (39.4% of them were high risk). There was a 1.5% presence of adenocarcinomas in the subjects. Polyps and CRC were predominant in men (P=.001 and P=.027, respectively) and there was a linear increase with age. Symptomatic patients had a higher CRC detection rate (P<.001), but no differences were observed in relation to polyp diagnosis. CONCLUSIONS: Age and male sex increased the risk for presenting with CRC or adenomas in the group of patients with a family history of CRC, and the presence of symptoms was associated with a greater risk for presenting with CRC.