A simple novel approach for detecting blood-brain barrier permeability using GPCR internalization.

AIMS: Impairment of blood-brain barrier (BBB) is involved in numerous neurological diseases from developmental to aging stages. Reliable imaging of increased BBB permeability is therefore crucial for basic research and preclinical studies. Today, the analysis of extravasation of exogenous dyes is the principal method to study BBB leakage. However, these procedures are challenging to apply in pups and embryos and may appear difficult to interpret. Here we introduce a novel approach based on agonist-induced internalization of a neuronal G protein-coupled receptor widely distributed in the mammalian brain, the somatostatin receptor type 2 (SST2). METHODS: The clinically approved SST2 agonist octreotide (1 kDa), when injected intraperitoneally does not cross an intact BBB. At sites of BBB permeability, however, OCT extravasates and induces SST2 internalization from the neuronal membrane into perinuclear compartments. This allows an unambiguous localization of increased BBB permeability by classical immunohistochemical procedures using specific antibodies against the receptor. RESULTS: We first validated our approach in sensory circumventricular organs which display permissive vascular permeability. Through SST2 internalization, we next monitored BBB opening induced by magnetic resonance imaging-guided focused ultrasound in murine cerebral cortex. Finally, we proved that after intraperitoneal agonist injection in pregnant mice, SST2 receptor internalization permits analysis of BBB integrity in embryos during brain development. CONCLUSIONS: This approach provides an alternative and simple manner to assess BBB dysfunction and development in different physiological and pathological conditions.

Smith Lemli-Opitz syndrome: a contribution to the delineation of a cognitive/behavioral phenotype.

AIM: Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive congenital malformation syndrome caused by an inborn error of cholesterol biosynthesis. The incidence is around 1:20000-1:70000. SLOS phenotype is very broad: severe phenotypes show exitus in perinatal period while milder phenotypes only show behavioral and learning problems. The purpose of this study is to further contribute to the delineation of a cognitive and behavioral phenotype in SLOS. METHODS: Nine patients with SLOS aged between 22 months and 25 years have been followed at the Department of Pediatrics, University of Naples "Federico II" for 2 years. A neuropsychologic study has been carried out in order to assess motor development, adaptive skills, social behavior, communication and language, temperament, aggressive behavior, symptoms typical of autism spectrum disorders (ASDs). RESULTS: The overall assessment of cognitive/behavioral phenotype showed severe / profound mental retardation in most of them (8/9) with a quite homogeneous neuropsychological profile. The language area was deficient both in expressive and receptive skills. Adaptive skills were in line with mental development. The presence of behavior problems (self-injury and stereotypies) was detected in 6 patients. The study of temperament showed a trend towards a sedentary lifestyle, lack of inhibition against novelty and danger, and reduced interest in the stimuli. None of our patients could be diagnosed as having ASDs. CONCLUSION: Although a specific behavioral phenotype for SLOS has gained support in the literature, we believe that many of the features described in individuals with SLOS are common to other mental retardation syndromes.

Surgical risk factors associated with lung transplantation.

BACKGROUND: Despite years of experience with lung transplantation, perioperative morbidity rates remain high. The objective of this study was to analyze our series of lung transplant recipients, seeking to identify possible intra- and postoperative risk factors associated with mortality. PATIENTS AND METHODS: We performed a descriptive, retrospective study of 224 consecutive patients undergoing lung transplantation over a period of 112 months; we excluded retransplant procedures. We gathered details of the surgical procedure and postoperative period in the recovery unit. Univariate analysis using the chi-square test identified variables associated with the incidence of mortality. RESULTS: From 1999 to 2008, we performed 224 lung transplants, including 66% in men and 34% in women. Their overall mean age was 49.9 +/- 13.5 years. The conditions that led to transplantation were pulmonary fibrosis (38.4%); chronic obstructive pulmonary disease emphysema (29%); cystic fibrosis (10.7%); bronchiectasis (8.9%); pulmonary hypertension (3.1%); and other diseases (9.9%). A total of 124 (55.4%) patients underwent single and 100 (44.6%) received sequential bilateral lung transplantations. Surgical risk factors were identified in 51.3% of the cases, the most frequent being hemorrhage (25.3%), followed by severe pulmonary hypertension (14.7%) and cardiopulmonary bypass (12.1%). Greater perioperative mortality was detected among patients with surgical risk factors, namely, significantly related to cardiopulmonary bypass, pulmonary hypertension, and air leak. A higher frequency of surgical risk factors was observed among patients with bilateral lung transplantations and longer procedures, but they were not associated with greater perioperative mortality. Reoperation was necessary in 16 patients (7.2%), mainly owing to bleeding, it was not significantly related to mortality risk. CONCLUSIONS: The incidence of surgical risk factors in lung transplantation was high, especially in bilateral lung transplantations and prolonged procedures. Postoperative bleeding requiring reoperation was not frequent and not associated with increased preoperative mortality in our series.

Reoperation in the postoperative period of lung transplantation.

BACKGROUND: Lung transplantation (LTx) has been established as the last treatment option in certain lung diseases. It is not uncommon for complications to occur that require urgent reoperation. The objective of our study was to analyze the characteristics of lung transplant patients who required reoperation in the postoperative period. PATIENTS AND METHODS: We have conducted a retrospective descriptive study of 224 lung transplants from January 1999 to September 2008, excluding retransplants. A subgroup of 16 subjects (7.2%) required reoperations. RESULTS: These 16 individuals had a mean age of 49.38 +/- 14.32 years with 75% men and 25% women. The disease leading to LTx was emphysema in 6 (37.5%), pulmonary fibrosis in 5 (31.3%), pulmonary hypertension in 2 (12.5%) and bronchiectasis, cystic fibrosis, and lymphangioleiomyomatosis in 1 each (6.3%). Preoperatively, 40% were taking corticosteroids. Double lung transplantation was performed in 56.3% and single lung in 43.7%. LTx surgery was prolonged in 68.8% of patients and intraoperative complications were more frequent than in the other patients (P = .041). The causes for reoperation were bleeding in 13 (of these, 5 had severe adhesions and 4 required extracorporeal circulation during LTx); bronchial dehiscence in 1; wall dehiscence in 1; and vascular stenosis in 1. At the end of the study, 62.5% were alive and among the 6 who died, 3 succumbed as a result of the surgery. Most subjects underwent late reoperation after a mean of 16 days from transplantation (range, 1-55). The need for reoperation was not associated with greater perioperative mortality. CONCLUSIONS: The incidence of reoperation in the postoperative period was low in our series. The main cause was bleeding. In more than half of the cases, LTx surgery was prolonged and intraoperative complications were more frequent. The need for reoperation was not associated with greater perioperative mortality.