Stenting and interventional radiology for obstructive jaundice in patients with unresectable biliary tract carcinomas

Together with biliary drainage, which is an appropriate procedure for unresectable biliary cancer, biliary stent placement is used to improve symptoms associated with jaundice. Owing to investigations comparing percutaneous transhepatic biliary drainage (PTBD), surgical drainage, and endoscopic drainage, many types of stents are now available that can be placed endoscopically. The stents used are classified roughly as plastic stents and metal stents. Compared with plastic stents, metal stents are of large diameter, and have long-term patency (although they are expensive). For this reason, the use of metal stents is preferred for patients who are expected to survive for more than 6 months, whereas for patients who are likely to survive for less than 6 months, the use of plastic stents is not considered to be improper. Obstruction in a metal stent is caused by a tumor that grows within the stent through the mesh interstices. To overcome such problems, a covered metal stent was developed, and these stents are now used in patients with malignant distal biliary obstruction. However, this type of stent has been reported to have several shortcomings, such as being associated with the development of acute cholecystitis and stent migration. In spite of these shortcomings, evidence is expected to demonstrate its superiority over other types of stent

Tratamentos integrados em efluente metal-mecânico: precipitação química e biotratamento em reator do tipo air-lift Integrated treatments for metalworking effluent: chemistry precipitation and biotreatment in air-lift reactor type

Os objetivos deste trabalho foram: realizar a caracterização físico-química de um efluente metal-mecânico e efetuar o tratamento integrado (precipitação química e biotratamento), utilizando micro-organismos autóctones do efluente (FI e FV) e uma referência (A. niger). A caracterização indicou pH de 1,7; cor de 1.495 mg Pt.L-1; demanda química de oxigênio de 9.147 mgO2.L-1; 887 mg.L-1 de óleo e graxa, além de 2,5 mgO2.L-1 de oxigênio dissolvido. Com o tratamento por precipitação química, obteve-se, em pH = 7,5, a redução de todos os íons metálicos investigados. Após o biotratamento, a cor foi reduzida em 95%, utilizando o micro-organismos FV. As reduções da demanda química de oxigênio e de óleo e graxa foram mais significativas utilizando FI, que reduziu os mesmos em 52 e 62%, respectivamente. Estes resultados indicaram que os micro-organismos autóctones do efluente foram mais eficazes no tratamento do mesmo do que o organismo de referência A. niger.<br>The objectives of this paper were: to perform the physical-chemical characterization of a metalworking effluent and to carry out the integrated treatment (chemical precipitation and biotreatment), using effluent autochthonous microorganisms (FI and FV) and a reference (A. niger). The characterization indicated pH of 1.7; color, 1,495 mg Pt.L-1; chemical oxygen demand, 9,147 mgO2.L-1; oil and grease, 887 mg.L-1, and dissolved oxygen with 2.5 mgO2.L-1. With the chemical precipitation treatment, in pH = 7.5, the reduction of all the investigated metallic ions was obtained. The color was reduced 95% after the biotreatment using the FV microorganism. The chemical oxygen demand and oil and grease reductions were more significant when using FI, which reduced the same in 52 and 62%, respectively. These results indicated that the autochthonous microorganisms were more efficient in the effluent treatment than the reference organism A. niger