Impact of White Adipose Tissue on Brain Structure, Perfusion, and Cognitive Function in Patients With Severe Obesity: The BARICO Study.

BACKGROUND AND OBJECTIVE: While underlying pathophysiology linking obesity to brain health is not completely understood, white adipose tissue (WAT) is considered a key player. In obesity, WAT becomes dysregulated, showing hyperplasia, hypertrophy, and eventually inflammation. This disbalance leads to dysregulated secretion of adipokines influencing both (cardio)vascular and brain health. Within this study, we investigated the association between omental WAT (oWAT) and subcutaneous WAT (scWAT) with brain structure and perfusion and cognition in adults with severe obesity. METHODS: Within the cross-sectional BARICO study, brain structure and perfusion and cognitive function were measured before bariatric surgery (BS) using MRI and cognitive assessments. During BS, oWAT and scWAT depots were collected and analyzed by histopathology. The number and diameter of adipocytes were quantified together with the amount of crown-like structures (CLS) as an indication of inflammation. Blood samples were collected to analyze adipokines and inflammatory markers. Neuroimaging outcomes included brain volumes, cortical thickness, white matter (WM) integrity, WM hyperintensities, cerebral blood flow using arterial spin labeling (ASL), and the ASL spatial coefficient of variation (sCoV), reflecting cerebrovascular health. RESULTS: Seventy-one patients were included (mean age 45.1 ± 5.8 years; 83.1% women; mean body mass index 40.8 ± 3.8 kg/m2). scWAT showed more CLS (z = -2.72, p < 0.01, r = -0.24) and hypertrophy compared with oWAT (F(1,64) = 3.99, p < 0.05, η2 = 0.06). Adiponectin levels were inversely associated with the average diameter of scWAT (ß = -0.31, 95% CI -0.54 to -0.08) and oWAT (ß = -0.33, 95% CI -0.55 to -0.09). Furthermore, the adipocyte diameter in oWAT was positively associated with the sCoV in the parietal cortex (ß = 0.33, 95% CI 0.10-0.60), and the number of adipocytes (per mm2) was positively associated with sCoV in the nucleus accumbens (NAcc) (ß = 0.34, 95% CI 0.09-0.61). Cognitive function did not correlate with any WAT parameter or plasma marker. These associations were highly influenced by age and sex. sCoV in the NAcc was positively associated with fasting plasma glucose (ß = 0.35, 95% CI 0.10-0.56). DISCUSSION: scWAT and oWAT are different in morphology and in their relationship with plasma markers and cerebrovascular health. Although scWAT showed more CLS and hypertrophy, scWAT was not associated with brain readouts. This study showed, however, important relationships between oWAT morphology and cerebrovascular health in obesity. TRIAL REGISTRATION INFORMATION: Trial Registration Number NTR7288 (trialregister.nl/trial/7090).

Lung ischemia-reperfusion injury: a molecular and clinical view on a complex pathophysiological process.

Lung ischemia-reperfusion injury remains one of the major complications after cardiac bypass surgery and lung transplantation. Due to its dual blood supply system and the availability of oxygen from alveolar ventilation, the pathogenetic mechanisms of ischemia-reperfusion injury in the lungs are more complicated than in other organs, where loss of blood flow automatically leads to hypoxia. In this review, an extensive overview is given of the molecular and cellular mechanisms that are involved in the pathogenesis of lung ischemia-reperfusion injury and the possible therapeutic strategies to reduce or prevent it. In addition, the roles of neutrophils, alveolar macrophages, cytokines, and chemokines, as well as the alterations in the cell-death related pathways, are described in detail.

Phase II multicenter clinical trial of pulmonary metastasectomy and isolated lung perfusion with melphalan in patients with resectable lung metastases.

INTRODUCTION: The 5-year overall survival rate of patients undergoing complete surgical resection of pulmonary metastases (PM) from colorectal cancer (CRC) and sarcoma remains low (20-50%). Local recurrence rate is high (48-66%). Isolated lung perfusion (ILuP) allows the delivery of high-dose locoregional chemotherapy with minimal systemic leakage to improve local control. METHODS: From 2006 to 2011, 50 patients, 28 male, median age 57 years (15-76), with PM from CRC (n = 30) or sarcoma (n = 20) were included in a phase II clinical trial conducted in four cardiothoracic surgical centers. In total, 62 ILuP procedures were performed, 12 bilaterally, with 45 mg of melphalan at 37°C, followed by resection of all palpable PM. Survival was calculated according to the Kaplan-Meier method. RESULTS: Operative mortality was 0%, and 90-day morbidity was mainly respiratory (grade 3: 42%, grade 4: 2%). After a median follow-up of 24 months (3-63 mo), 18 patients died, two without recurrence. Thirty patients had recurrent disease. Median time to local pulmonary progression was not reached. The 3-year overall survival and disease-free survival were 57% ± 9% and 36% ± 8%, respectively. Lung function data showed a decrease in forced expiratory volume in 1 second and diffusing capacity of the alveolocapillary membrane of 21.6% and 25.8% after 1 month, and 10.4% and 11.3% after 12 months, compared with preoperative values. CONCLUSION: Compared with historical series of PM resection without ILuP, favorable results are obtained in terms of local control without long-term adverse effects. These data support the further investigation of ILuP as additional treatment in patients with resectable PM from CRC or sarcoma.

Selective pulmonary artery perfusion with melphalan is equal to isolated lung perfusion but superior to intravenous melphalan for the treatment of sarcoma lung metastases in a rodent model.

OBJECTIVES: Isolated lung perfusion (ILuP) and selective pulmonary artery perfusion (SPAP) are experimental surgical techniques to deliver high-dose chemotherapy selectively to the lung for the treatment of lung metastases. ILuP with melphalan (MN) has shown to be feasible in clinical studies but can only be used once because it is invasive. SPAP as an endovascular technique can be repeated several times, but no results have been reported so far. Pharmacokinetics and efficacy of SPAP with MN were studied in a rodent lung metastasis model and compared it with ILuP and intravenous (IV) therapy. METHODS: Pharmacokinetics: forty-five Wag-Rij rats were randomized into three groups: IV 0.5 mg MN, ILuP 0.5 mg MN and SPAP 0.5 mg MN. Every treatment group was again randomized in three groups: 15 min treatment, 30 min treatment and 30 min treatment with 30 min reperfusion. Blood and tissue samples were taken for MN concentrations. EFFICACY: twenty-five Wag-Rij rats were randomized into five groups: control, sham thoracotomy, IV 0.5 mg MN, ILuP 0.5 mg MN and SPAP 0.5 mg MN. At day 0, bilateral lung metastases were induced, and treatment followed at day 7. At day 28, rats were sacrificed and pulmonary metastases counted. Survival: thirty Wag-Rij rats were randomized into five groups: control, sham ILuP, IV 0.5 mg MN, ILuP 0.5 mg MN, SPAP 0.5 mg MN. At day 0, left-sided lungmetastases were induced with treatment at day 7. Endpoints were death due to disease or survival up to 90 days. RESULTS: Pharmacokinetics: SPAP and ILuP resulted in significantly higher left lung MN concentrations compared with IV (P = 0.05). EFFICACY: SPAP (30 ± 22 nodules) and ILuP (20 ± 9 nodules) resulted in significantly less nodules compared with IV (113 ± 17 nodules; P < 0.01). Survival: median survival of SPAP (74 ± 8 days) was equal to ILuP MN (71 ± 10 days) but significantly longer compared with IV (54 ± 7 days; P < 0.01 both). CONCLUSIONS: SPAP with MN for the treatment of sarcoma lung metastases in rats is equally effective to ILuP but resulted in a significantly better survival compared with IV MN. As SPAP can be applied as a minimally invasive endovascular procedure, continued research with this technique is warranted.

Long-term survival of a phase I clinical trial of isolated lung perfusion with melphalan for resectable lung metastases.

OBJECTIVE: Surgical resection of lung metastases is a widely accepted procedure but 5-year survival rates remain low and vary between 20% and 50%. Isolated lung perfusion (ILuP) is an experimental technique to deliver a high dose of chemotherapy to the lung, without systemic toxicity. Long-term survival of ILuP has not been reported yet and was determined in a phase I clinical trial. METHODS: From May 2001 to December 2004, a phase I clinical trial was conducted to define the maximum tolerated dose (MTD) of ILuP with melphalan. Twenty-nine procedures were performed in 23 patients. The primary tumour was colorectal in 10 patients, renal in eight, sarcoma in four and salivary gland in one. Toxicity results were previously reported and the MTD of melphalan was determined at 45 mg when given at 37°C. Follow-up was updated and long-term survival is reported. RESULTS: Follow-up was complete, except for one patient who was lost to follow-up after 8 months. After a median follow-up of 62 months, 6 out of 23 patients were alive and free of recurrent disease. One patient died after a subsequent operation. Sixteen patients developed recurrent disease, of whom 11 died. Nine patients had intrathoracic recurrent disease only, one intra- and extrathoracic recurrences each and five extrathoracic only. In one patient, the location of recurrence was not known. Overall- and disease-free 5-year survival rates were 54.8 ± 10.6% and 27.5 ± 9.5%, respectively with an overall median survival time (MST) of 84 months (95% confidence interval (CI): 41-128) and disease-free MST of 19 months (95% CI: 4-34). Lung function and diffusion capacity initially dropped 1 month after perfusion, slightly improving afterwards. Radiographic follow-up with chest computed tomography showed no long-term toxicity from ILuP. CONCLUSION: ILuP can be applied without major long-term pulmonary toxicity. Five-year survival rate, overall and disease-free MST in this phase I clinical trial are promising. This is another incentive to perform further studies with ILuP.