Pleurovenous Shunt Placement for the Management of Nonmalignant Pleural Effusion.

Therapeutic thoracentesis is a first-line therapy in the management of patients with medically refractory, nonmalignant pleural effusion. However, when required in short intervals, serial thoracenteses can lead to increased procedure-related complications and negatively impact quality of life. Alternative treatment options vary depending on the etiology of fluid accumulation. Hepatic hydrothorax secondary to cirrhosis is a common cause of medically refractory pleural effusion encountered by interventional radiologists. In select patients in whom surgical pleurodesis, transjugular intrahepatic portosystemic shunt placement, and/or tunneled pleural catheter placement cannot be performed or provide inadequate relief, implantation of a pleurovenous (Denver) shunt may assist in palliation. The Denver shunt system allows decompression of pleural fluid into the central venous circulation by utilizing unidirectional valves and a manually operated subcutaneous pump. Though limited reports have described favorable technical and clinical success, more research is required to determine the safety and efficacy of this procedure. This article discusses pleurovenous shunt placement, postprocedure shunt evaluation, and potential associated complications.

Synthesis and structural characterization of the peptide epitope of the ovarian cancer biomarker CA125 (MUC16).

A highly conserved region of 21 amino acids flanked by cysteine residues, contained within a larger repeated domain, has been proposed to be the antibody-binding site in the ovarian cancer biomarker CA125 (MUC16). In this study solid-phase peptide synthesis with Fmoc protection chemistry was used to assemble a 21-mer peptide corresponding to the most frequently occurring antibody binding sequence in CA125. Potentially significant sequence variants were also synthesized. Peptide secondary structure was investigated using Fourier transform infrared spectroscopy, revealing the consensus sequence peptide to be largely unstructured at physiological pH whether the cysteine residues were reduced or were oxidized to form an intramolecular disulfide bond. Substitution of serine for proline at position 8 (P8S) results in ß-sheet formation in peptides involved in intramolecular disulfide bonds. This ß-sheet structure does not persist in peptides incapable of intramolecular disulfide bonding because of sequence nor in peptides treated with the reducing agent dithiothreitol. In CA125, P8S is predicted to occur in ∼25% of repeat domains, suggesting that this structural motif is a non-negligible contributor to overall structure and function. These findings suggest that future structural characterization efforts of CA125 should be especially mindful of the amino acid sequence and oxidation state of the protein.