An Assessment of the Feasibility of Phytoextraction for the Stripping of Bioavailable Metals from Contaminated Soils.

Phytoextraction has been proposed in many papers as a low-cost method for remediating contaminated soil. However, if national regulation is based on total metal(loid) concentrations in soil, phytoextraction is generally infeasible because of the long time required for remediation. Assessing phytoextraction requires determination of the dynamic rate of metal removal from soil. Phytoextraction may be feasible if the main goal is to reduce the soluble fraction of the metal(loid) with the goal of reducing bioavailability. However, it has been reported that there is a large mass balance mismatch between the reduction of the soluble metal fraction in contaminated soil and metal uptake by plants. Several studies report that the decrease of soluble fraction of metals in soil is higher than can be accounted for by plant uptake. In other words, studies generally overestimate the feasibility of bioavailable contaminant stripping. Therefore, a more rigorous approach is advisable to ensure that papers on bioavailable contaminant stripping include relevant information on mass balances. Furthermore, to implement the concept of bioavailable contaminant stripping, regulations must distinguish between the bioavailable fraction and the total metal concentration in soil. Environ Toxicol Chem 2023;42:558-565. © 2022 SETAC.

Which soil Cu pool governs phytotoxicity in field-collected soils contaminated by copper smelting activities in central Chile?

Several studies have attempted to predict the so-called "phytoavailable" fraction by correlating plant responses with different soil metal pools. Most of the data derived from these studies tend to be inconsistent, making interpretations difficult. Thus, the main objective of this study was to determine which soil Cu pool (free Cu2+, salt-exchangeable Cu or total Cu) controls Cu phytotoxicity in soils near a Cu smelter in central Chile. We studied the following traits of the local plant community grown spontaneously on the study site: species richness, shoot biomass, and plant cover. The site was dominated by four early plant colonizers: Eschscholzia californica Cham., Hirschfeldia incana (L.) Lagr.-Fossat, Lolium perenne L., and Vulpia bromoides (L.) Gray. We determined exchangeable soil Cu and activity of free Cu2+ in 0.1 M KNO3 extracts using soil/solution ratio of 1/2.5. The effect of total soil Cu on plant responses was not significant (p > 0.05). In our field-collected soil series, exchangeable Cu was a better indicator of soil phytotoxicity than either total soil Cu or free Cu2+ in the soil solution. We determined upper critical threshold values for Cu exposure using the three plant traits cited above. The mean values of EC10, EC25, and EC50 (effective concentration at 10%, 25%, and 50%, respectively) of exchangeable soil Cu (in µg L-1) were 255, 391, and 533, respectively. The mean EC10, EC25 and EC50 values of pCu2+ were 7.5, 6.8, and 5.9, respectively. We highlight the importance of further studies on Cu phytotoxicity using actual field-contaminated soils.

[Synchronic bilateral testicular seminomas. Ultrasound diagnosis]. / Seminomas testiculares bilaterales sincrónicos. Diagnóstico ecográfico.

OBJECTIVES: To report a new case of bilateral synchronic testicular tumors, and to perform a bibliographic review on the topic, emphasizing the ultrasound characteristics and oddity of these presentation, which accounts for less than 1% of germ cell testicular tumors. METHODS/RESULTS: 29-year-old patient consulting because of an increase of the testicular size over one year. Physical examination and ultrasound revealed a synchronic neoplastic involvement of the testicles, suggesting the radiological diagnosis of bilateral "seminomatous tumor", with "non seminomatous" foci in one of them. Histologically, tumors were in accordance with ultrasound working diagnosis (seminomas, showing one of them anaplastic foci). CONCLUSIONS: Synchronic testicular involvement by neoplasias is an unfrequent fact, scarcely reported in the literature, being most cases germ cell tumors, mainly seminomas, and shows a good correlation between ultrasound and histologic diagnosis.

[Renal pseudoaneurysm and arteriovenous fistula: color doppler study of a post-lithotripsy simple cyst]. / Pseudoaneurisma y fístula arteriovenosa renal estudio mediante doppler color de quiste simple post-litotricia.

OBJECTIVES: To describe the clinical and radiological (color doppler ultrasound, CT scan and arteriography) features of a case of renal arteriovenous malformation type mixed fistula with pseudoaneurysm in a female patient after extracorporeal shock wave lithotripsy. METHODS/RESULTS: We report one case of secondary vascular malformation in a 54-year-old female patient who underwent extracorporeal shockwave lithotripsy, presenting as recurrent hematuria. Ultrasound detected a "cystic" formation newly appeared after lithotripsy, being the diagnostic made by a color doppler study which showed a mixed high speed arteriovenous turbulent flow. The lesion showed intense intravenous contrast uptake on CT scan. Diagnosis was confirmed by arteriography. CONCLUSIONS: External shock wave lithotripsy is, as well as interventional procedures, a known cause of renal vascular complications, so that doppler color studies may be diagnostic in patients with suggestive clinical features, focusing specially on those lesions or morphological abnormalities newly appeared when compared to pre-treatment studies.

Recidiva paratesticular de carcinoma renal / Paratesticular metastasis from renal cell carcinoma

OBJETIVO: Describir las características clínicas e histopatológicas que presenta la recidiva de un carcinoma de células renales en el testículo, ya que la rareza de esta forma de presentación puede suponer dificultades diagnósticas y, consecuentemente, de estadiaje y tratamiento de la enfermedad. MÉTODOS/RESULTADOS: Presentamos un caso de metástasis paratesticular de carcinoma renal en un paciente de 65 años, diagnosticado, tras nefrectomía, 3 años antes. El estudio histológico muestra las típicas características citohistológicas e inmunohistoquímicas de esta neoplasia: nidos de células epiteliales claras con positividad inmunohistoquímica para Vimentina, Citoqueratinas y EMA. CONCLUSIÓN: Aunque el carcinoma de células renales metastatiza raramente al área testicular, el estudio histológico constituye un método fundamental para el diagnóstico definitivo y el planteamiento terapéutico de la enfermedad (AU)