Probing non polar interstellar molecules through their protonated form: Detection of protonated cyanogen (NCCNH+)

Cyanogen (NCCN) is the simplest member of the series of dicyanopolyynes. It has been hypothesized that this family of molecules can be important constituents of interstellar and circumstellar media, although the lack of a permanent electric dipole moment prevents its detection through radioastronomical techniques. Here we present the first solid evidence of the presence of cyanogen in interstellar clouds through the detection of its protonated form toward the cold dark clouds TMC-1 and L483. Protonated cyanogen (NCCNH+) has been identified through the J = 5 - 4 and J = 10 - 9 rotational transitions using the 40m radiotelescope of Yebes and the IRAM 30m telescope. We derive beam averaged column densities for NCCNH+ of (8.6 ± 4.4) × 1010 cm-2 in TMC-1 and (3.9 ± 1.8) × 1010 cm-2 in L483, which translate to fairly low fractional abundances relative to H2, in the range (1-10) × 10-12. The chemistry of protonated molecules in dark clouds is discussed, and it is found that, in general terms, the abundance ratio between the protonated and non protonated forms of a molecule increases with increasing proton affinity. Our chemical model predicts an abundance ratio NCCNH+/NCCN of ~ 10-4, which implies that the abundance of cyanogen in dark clouds could be as high as (1-10) × 10-8 relative to H2, i.e., comparable to that of other abundant nitriles such as HCN, HNC, and HC3N.

Necrotizing pancreatitis: a surgical approach independent of documented infection

BACKGROUND

Strategies for the management of patients with necrotizing pancreatitis remain controversial. While consensus opinion supports operative necrosectomy for the treatment of infected pancreatic necrosis, the timing for surgical intervention is not completely resolved. Further, the indication for the surgical management of sterile pancreatic necrosis is also subject to debate.

METHODS

The objective of this study was to evaluate outcome measures for the surgical management of necrotizing pancreatitis, independent of documented infection. A retrospective review was undertaken between 1994 and 2002 at a single county hospital.

RESULTS

Twenty-one patients with CT-documented necrotizing pancreatitis underwent operative pancreatic necrosectomy with laparostomy within 21 days of initial diagnosis and had an average of three reoperations. Average length of stay (LOS) in the ICU was 36 days and in the hospital 67 days. Ten patients had documented infected necrosis based on initial intra-operative cultures, while I I had sterile necrosis. Overall, 95% (20/21) of the patients had a complication, with an average of three complications per patient. Common complications included ARDS (71%), sepsis (33%), renal failure (24%), and pneumonia (24%). The overall mortality rate was 14% (3/21), with a mean follow-up of 469 days.

DISCUSSION

The surgical management of acute necrotizing pancreatitis, independent of documented infection, can be undertaken within 3 weeks of diagnosis with an acceptable morbidity and a low mortality rate. Creation of a laparostomy to enable ready, atraumatic debridement of the retroperitoneum is a safe alternative to standard repeat laparotomies and thus represents a useful adjunct to the surgical management of necrotizing pancreatitis.

Surgical treatment of complex forms of transposition

In spite of the new knowledge developed in recent years surgical treatment for patients with complex forms of transposition of the great arteries remains suboptimal. This is because of the morbidity and mortality that have followed many of the corrective operations, and these are related chiefly to the basic malformation and its secondary effects. This review summarizes information about surgical treatment of such patients and comments upon some of the implications of this experience.

Double-outlet right ventricle with transposed great arteries and subpulmonary ventricular septal defect. The Taussig-Bing malformation

The angiocardiographic findings and successful surgical treatment of three patients with double-outlet right ventricle, bilateral conus, transposition of the great arteries, subpulmonary ventricular septal defect, and pulmonary-mitral valve discontinuity are reported. The atria, viscera, and ventricles were normally located, and the aorta originated to the right and anterior to the pulmonary artery.

Surgical repair was accomplished by closure of the ventricular septal defect in such a way that left ventricular outflow was routed via a prosthetic tunnel to the pulmonary artery. Then systemic venous return was transposed intra-atrially by the Mustard technique.

All patients survived complete repair and have continued to improve over a period ranging from several months to 1 year after operation. In one patient complete heart block developed postoperatively, necessitating the insertion of a permanent electronic pacemaker. Details of the method of repair and preoperative studies are presented.