Pediatric liver transplantation: preliminary results at Istituto Mediterraneo Trapianti e Terapie ad Alta Specializzazione

Between July 2003 and November 2004 14 pediatric liver transplantations (LTx) have been performed in 12 children using cadaveric donors. The primary diseases were as follows biliary atresia in 9 cases, whereas the other 3 children were affected by cystic fibrosis, Langherans cells histiocytosis, and hepatoblastoma, respectively. Median patient waiting time was 103 days (range, 2-158); no patient died while on the waiting list. Patients who underwent transplantation included 7 boys and 5 girls, ranging in age from 6 months to 14 years (median age, 5 years). Recipient median weight was 16 kg (range, 6-38). Donor median age was 19 years (range, 3-47), whereas donor median weight was 74 kg (range, 15-90). All children who underwent primary LTx were United Network for Organ Sharing (UNOS) status 2B. Of the 12 transplanted patients, 9 received a left lateral segment (LLS) from an in situ split liver, whereas 3 received a whole graft. Two children developed an episode of acute cellular rejection on the seventh postoperative day, which was treated successfully with a course of intravenous steroids for 3 days. After a median follow-up of 245 days, 10 children are alive but 2 children died due to primary nonfunction (PNF) on the second postoperative day and septic shock on the fifth postoperative day after retransplantation for acute hepatic artery thrombosis, respectively. One child who underwent retransplantation for hepatic artery thrombosis on the 31st postoperative day after primary LTx is currently alive. Evaluation of our initial data suggests that the split liver technique has the potential to meet the needs of pediatric LTx allowing grafting early in the course of the original disease and reducing waiting time.     

Cerebral metabolic responses of hyperglycemic immature rats to hypoxia-ischemia

Unlike adult rats, glucose supplementation of immature rats does not lead to accentuated hypoxic-ischemic brain damage. To explore the reason for this age-specific paradox, we subjected 7-day postnatal rats to unilateral common carotid artery occlusion followed by a subcutaneous injection of either 0.1 ml 50% glucose or normal saline. They were then exposed to hypoxia with 8% oxygen, during which they received 2.5 microCi 2-[14C]-glucose or were quick-frozen for brain metabolite analysis. During hypoxia-ischemia, glucose transport into the ipsilateral cerebral hemisphere of the hyperglycemic rats was greater (+100-150%) than in normoglycemic animals. However, glucose consumption was similar in the two groups. Glucose concentrations in brain were lower during hypoxia-ischemia in the normoglycemic animals, whereas lactate increased to similar levels in the two groups. The high-energy phosphate reserves, ATP and phosphocreatine, were depleted to a similar extent. Thus, hyperglycemia combined with hypoxia-ischemia, although associated with increased glucose transport into brain, does not lead to enhanced glucose utilization or lactate accumulation by brain over that of hypoxia-ischemia alone.     

Coverant control of self-evaluations through temporal cueing

Procedures involving temporal cueing of coverant emission were employed in the treatment of a case of interpersonal anxiety and depression. Spontaneous rate of positive self-evaluations was increased by the therapy procedures and maintained after the procedures were terminated. Concomitant improvements were reported for behavioral measures. The results are compared with previous attempts to use cueing procedures for coverant control and potential differences are suggested.     

Development of a PCR-ELISA assay for diagnosis of Perkinsus marinus and Perkinsus atlanticus infections in bivalve molluscs

Perkinsus atlanticus and P. marinus have been associated with mass mortality of bivalve molluscs. Perkinsus infections are routinely diagnosed by histology or the fluid thioglycollate medium (FTM) assay. In this study, we describe the development of a PCR-enzyme-linked immunosorbent assay (ELISA) for amplification and rapid detection of Perkinsus species. The PCR reactions were selected to either amplify an IGS sequence region shared by currently accepted Perkinsus species or to simultaneously amplify IGS regions specific to either P. atlanticus or P. marinus. The specific hybridisation of DIG-labelled amplified products to species-specific capture probes was detected colorimetrically. This assay is able to specifically detect P. atlanticus and P. marinus, and the intensity of the colorimetric signal is dependent upon the amount of amplified product. The PCR-ELISA assay format is 100-fold more sensitive than visualisation of PCR products on ethidium bromide (EtdBr)-stained agarose gels, and as sensitive as Southern hybridisation. The sensitivity limit of PCR-ELISA was 1 pg of DNA from P. atlanticus. No cross-reactivity of the assay was observed against the host DNA. When applied to the detection of P. atlanticus in clams, 39 samples out of 45 yielded concordant results for FTM assay and PCR-ELISA detection.     

Structural and functional diversity of the lectin repertoire in teleost fish: relevance to innate and adaptive immunity

Protein-carbohydrate interactions mediated by lectins have been recognized as key components of innate immunity in vertebrates and invertebrates, not only for recognition of potential pathogens, but also for participating in downstream effector functions, such as their agglutination, immobilization, and complement-mediated opsonization and killing. More recently, lectins have been identified as critical regulators of mammalian adaptive immune responses. Fish are endowed with virtually all components of the mammalian adaptive immunity, and are equipped with a complex lectin repertoire. In this review, we discuss evidence suggesting that: (a) lectin repertoires in teleost fish are highly diversified, and include not only representatives of the lectin families described in mammals, but also members of lectin families described for the first time in fish species; (b) the tissue-specific expression and localization of the diverse lectin repertoires and their molecular partners is consistent with their distinct biological roles in innate and adaptive immunity; (c) although some lectins may bind endogenous ligands, others bind sugars on the surface of potential pathogens; (d) in addition to pathogen recognition and opsonization, some lectins display additional effector roles, such as complement activation and regulation of immune functions; (e) some lectins that recognize exogenous ligands mediate processes unrelated to immunity: they may act as anti-freeze proteins or prevent polyspermia during fertilization.     

Regional cerebral blood flow during hypoxia-ischemia in immature rats

Immature rats subjected to a combination of unilateral common carotid artery ligation and hypoxia sustain brain damage confined largely to the ipsilateral cerebral hemisphere. To ascertain the extent and distribution of ischemic alterations in the brains of these small animals, we modified the Sakurada technique to measure regional cerebral blood flow using carbon-14 autoradiography. Seven-day-old rats underwent right common carotid artery ligation following which they were rendered hypoxic with 8% O2 at 37 degrees C. Before and during hypoxia, the rat pups received an injection of iodo[14C]antipyrine for determination of regional cerebral blood flow. Blood flows to individual structures of the ipsilateral cerebral hemisphere were not influenced by arterial occlusion alone; flows to the contralateral hemisphere and to the brainstem and cerebellum actually increased by 25-50%. Hypoxia-ischemia was associated with decreases in regional cerebral blood flow of the ipsilateral hemisphere such that by 2 hours, flows to subcortical white matter, neocortex, striatum, and thalamus were 15, 17, 34, and 41% of control, respectively. The hierarchy of the blood flow reductions correlated closely with the distribution and extent of ischemic neuronal necrosis. However, unlike the pathologic pattern of this model, the degree of ischemia appeared homogeneous within each brain region. Blood flows to contralateral cerebral hemispheric structures were relatively unchanged from prehypoxic values, whereas flows to the brainstem and cerebellum nearly doubled and tripled, respectively. Thus, ischemia is the predominant factor that determines the topography of tissue injury to major regions of immature rat brain, whereas metabolic factors (intrinsic vulnerability) may influence the heterogeneous pattern of damage seen within individual structures.