Noninvasive evaluation of renal tissue oxygenation with blood oxygen level-dependent magnetic resonance imaging early after transplantation has a limited predictive value for the delayed graft function.

PURPOSE: The aim of this study was to evaluate the feasibility of renal oxygenation assessment using blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in the early period after kidney transplantation and to estimate its prognostic value for delayed graft function. MATERIAL AND METHODS: Examinations were performed in 50 subjects: 40 patients within a week after the kidney transplantation and 10 healthy controls, using T2*-weighted sequence. Measurements in transplant patients were correlated to basic laboratory parameters in the early period after transplantation and at follow-up. RESULTS: Examinations of seven patients (18%) were rejected due to their poor technical quality. Mean R2* values in transplant recipients were lower than in controls (11.6 vs. 15.9 Hz; p = 0.0001). An R2* value of 0.28 Hz was calculated as the minimal detectable change. There was no relation between R2* values and laboratory parameters. However, patients eGFR ≥ 40 ml/min/1.73 m2 presented higher R2* values than recipients eGFR < 40 ml/min/1.73 m2 (12.0 vs. 11.1 Hz; p = 0.0189). In ROC analysis R2* of ≤ 11.7 predicted an early reduced graft function with 0.82 sensitivity and 56% specificity (AUC = 0.708; p = 0.024) but was not useful for delayed graft function prediction (p > 0.7). CONCLUSIONS: Evaluation of renal graft oxygenation using BOLD MRI is technically challenging in the early period after transplantation. An R2* value of 0.28 Hz may in practice be considered as the minimal detectable change. The delayed graft function seems not to be dependent on early oxygenation values. Further, large-scale studies are necessary to confirm the latter observation.

Diagnosing Ring Current(s) in Figure-Eight Skeletons: A 3D Through-Space Conjugation in the Two-Loops Crossing.

The macrocyclic structures with local conjugation readily undergo a redox-triggered change in the diatropic character, leading to a global current-density pathway of the doubly charged systems. The figure-eight geometry of the neutral dimer does not significantly change upon oxidation according to the spectroscopic and computational data. The oxidation leads to 3D cross-conjugation at the intersection of the two ethylene bridges resulting in a global ring current.

Pancreaticopleural fistulas of different origin: Report of two cases and a review of literature.

BACKGROUND: Pancreaticopleural fistula (PPF), a form of internal pancreatic fistula, is a rare complication of acute or chronic pancreatitis or pancreatic trauma. CASE REPORT: We report two cases of PPF resulting in formation of pleural pancreatic pseudocysts. A 35-year-old male alcoholic patient with a history of recurrent episodes of acute pancreatitis was admitted due to a severe dyspnea. A CT scan showed a significant left pleural effusion with a total left lung atelectasis, compression of the mediastinum, and dislocation of the left diaphragm. A follow-up CT showed a fistula between the abdominal pancreatic pseudocyst and the left pleural cavity. The second case was a 13-year-old male patient, who was admitted for a splenic stump excision. Two weeks after the surgery the patient presented a massive pleural amylase-rich effusion. CT exam suggested a PPF, which was indirectly confirmed by a thoracoscopy. CONCLUSIONS: PPF should be considered in cases of massive pleural effusion and encapsulated pleural fluid collections in patients with a history of acute pancreatitis and surgery involving pancreas.