Partitioning of porcine pancreatic lipase in a two-phase systems of polyethylene glycol/potassium phosphate aqueous.

The hydrolysis of triglycerides at the oil-water interface, synthesis of esters and transesterification in microaqueous conditions are catalysed by lipase. For its application, a proper purification method was necessary. This study examined the application of an aqueous two-phase system to partition porcine pancreatic lipase. The influence of molecular weight and concentration of polyethylene glycol (PEG), tie line length (TLL), potassium phosphate concentration, sodium chloride (NaCl) addition and temperature in the partition was studied. The enzyme was more efficiently purified in PEG 8,000 at 14.5 degrees C (PF = 3.89-fold), presenting more recoveries at the top phase with shorter TLL and lower concentrations of PEG and potassium phosphate. Moreover, the increase of these variables repressed the purification and the further addition of NaCl did not promote the purification of the enzyme. These results demonstrated the efficiency of the aqueous two-phase system on lipase purification.

2-Chloro-deoxyadenosine induces durable complete remission in Castleman's disease but may accelerate its transformation to non-Hodgkin's lymphoma.

There is currently no consensus on the best treatment for unresectable hyaline-vascular variant or for multicentric Castleman's disease (MCD), because none of the reported regimens have consistently produced complete response or durable remission in the majority of patients In the present study, we report on the use of 2-CdA (2-chloro-deoxyadenosine) in three patients, two of them with MCD and one with unresectable hyaline-vascular type disease. Relapse-free survival of the responding patients was 24 and 20 months. Later, both patients evolved to non-Hodgkin's lymphoma (NHL) (diffuse large B-cell lymphoma and peripheral T-cell NHL, respectively). 2-CdA typically causes a long-lasting state of immunodeficiency and the profound influence of this drug on the immune system has raised questions concerning the emergence of secondary neoplasms after its use. Therefore, it is reasonable to conclude that: 1) 2-CdA can induce durable complete remission in MCD patients but unfortunately it cannot cure the disease; 2) the possibility that 2-CdA may accelerate the transformation of MCD to NHL cannot be ruled out.