Giant mature cystic teratoma of the mediastinum resected by VATS: a case report.

The incidence of mediastinal teratomas is low, it's important to recognize them between all the differential diagnoses for mediastinal tumors. The treatment is surgical resection. We report a giant mature cystic teratoma of the mediastinum in a 40-year-old woman. She presented with dyspnea, flu-like symptoms during the previous 5 days. An x-ray complemented with a chest CT scan showed a heterogeneous extrapulmonary multiloculated and predominantly fluid density tumor located at the left side of the mediastinum. The patient underwent resection by video-assisted thoracic surgery (VATS). The tumor was 15 cm in diameter with a predominant cystic component. Histologic examination revealed a mature cystic teratoma. Treatment of these tumors should attempt a complete resection. Open approaches are painful, require a longer recovery and are associated with higher morbidity. VATS has been used to treat these tumors, demonstrating the same effectiveness and advantages over open procedures.

Primary tracheal schwannoma resected in a Turner syndrome patient: a case report.

We report a case of primary tracheal schwannoma in a 31-year-old woman. She had a previous history of follicular thyroid carcinoma treated surgically and Turner syndrome. In a follow-up computed tomography scan, we found a partially obstructing intraluminal tracheal tumor, which was confirmed by bronchoscopy. The patient was treated by surgical resection and primary tracheal anastomosis. The tumor was 14 mm in diameter, with an intact capsule. Histologic analysis revealed a Schwann cell origin tumor.

Heavy metal content in soils under different wastewater irrigation patterns in Chihuahua, Mexico.

An area near the city of Chihuahua has been traditionally irrigated with wastewater to grow forage crops. It has been hypothesized that metal levels could be found in these soils high enough to cause potential health problems to the population. The objective of this study was to determine heavy metal concentrations in different soils due to irrigation practices. Four soil types were evaluated; a soil with a past and present history of wastewater irrigation (S1), a soil with a history of wastewater irrigation until 2003 (S2), a soil with no irrigation history (S3), and a soil similar to S1 and adjacent to the river where the wastewater is transported (S11). Three soil depths were evaluated; 0-15, 15-30 and 30-50 cm. Consequently, a total of 150 soil samples were analyzed evaluating pH, EC, OM and the following elements; Na, K, Cd, Pb, Ni, Cr, Cu and Fe. The pH (P=0.000) and EC (P=0.000) were different for each soil type but no differences were noted for soil depth and the interaction. Maximum pH levels were noted in S3 with a value of 8.74 while maximum EC was observed in S1 with a value of 0.850 dSm-1. The OM level was different for soil type (P=0.000), soil depth (P=0.005) and the interaction (P=0.014). S1 and S11 obtained maximum levels of OM while minimum levels were noted in S3. Maximum OM levels were observed at the 0-15 cm depth followed by the 15-30 cm depth and finally at the 30-50 cm depth. The highest concentration of metals was as follows: K in S1 (359.3 mg kg-1); Cd in S1 (4.48 mg kg-1); Pb in S11 (155.83 mg kg-1); Ni in S1 (10.74 mg kg-1); Cu in S1 (51.36 mg kg-1); B in S3 (41.5 mg kg-1); Fe in S3 (20,313.0 mg kg-1), Cr in S3 (44.26 mg kg-1) and Na in S3 (203.0 mg kg-1). The conclusion is that some metals are present in the soils due to anthropogenic activities but others are present in natural forms.

Application of a low density support material as an alternative to prevent clogging in a three-phase fluidized-bed reactor.

A low density support material was evaluated to determine its effect on biofilm growth dynamics when treating synthetic wastewater in a three-phase fluidized-bed reactor. After two 40-day experimental runs, the results showed significant microbial activity from the very beginning of the study. The highest biofilm growth was observed during the first 10 days of operation. Biofilm kept gradually growing after the 11th day and reached a steady-state at day 21, defined by a consistent biomass attached to the particles. As an indicator of biofilm detachment effluent suspended biomass decreased as biofilm attachment increased, tending also to stabilize around day 21. During the first 10 days, chemical oxygen demand removal averaged 100 mg l(-1) representing 48% of the influent chemical oxygen demand concentration. The highest chemical oxygen demand removal efficiency (78%) was achieved between days 23 and 29, when influent chemical oxygen demand was 280 mg l(-1). The support material evaluated proved to be effective at allowing attachment of microorganisms. Due to its low density, bed fluidization was achieved under recirculation rates lower than those required to fluidize beds of higher density. The physical properties of the proposed support material allowed an appropriate equilibrium to be achieved between biomass attachment and detachment, eliminating the need for bed backwashing.