Project description:ObjectiveRight lung transplantation in rats has been attempted occasionally, but the technical complexity makes it challenging to apply routinely. Additionally, basic research on inverted lobar lung transplantation is scarce because of the lack of a cost-effective experimental model. We first reported right lung transplantation in a rat model using left-to-right inverted anastomosis to imitate the principle of clinically inverted lung transplantation.MethodsRight lung transplantation was performed in 10 consecutive rats. By using a 3-cuff technique, the left lung of the donor rat was implanted into the right thoracic cavity of the recipient rat. The rat lung graft was rotated 180° along the vertical axis to achieve anatomic matching of right hilar structures. Another 10 consecutive rats had received orthotopic left lung transplantation as a control.ResultsAll lung transplantation procedures were technically successful without intraoperative failure. One rat (10%) died of full pulmonary atelectasis after right lung transplantation, whereas all rats survived after left lung transplantation. No significant difference was observed in heart-lung block retrieval (8.6 ± 0.8 vs 8.4 ± 0.9 minutes), cuff preparation (8.3 ± 0.9 vs 8.7 ± 0.9 minutes), or total procedure time (58.2 ± 2.6 vs 56.6 ± 2.1 minutes) between the right lung transplantation and standard left lung transplantation groups (P > .05), although the cold ischemia time (14.2 ± 0.9 vs 25.5 ± 1.7 minutes) and warm ischemia time (19.8 ± 1.5 vs 13.7 ± 1.8 minutes) were different (P < .001).ConclusionsRight lung transplantation with a left-to-right inverted anastomosis in a rat model is technically easy to master, expeditious, and reproducible. It can potentially imitate the principle of clinically inverted lung transplantation and become an alternative to standard left lung transplantation.
Project description:BackgroundAlthough single and double lung transplantation outcomes for chronic obstructive pulmonary disease (COPD) have been investigated, right and left single lung transplants have never been rigorously compared to evaluate disease-specific differences. Single lung transplants for COPD often have hyperinflation of the contralateral native lung, which may be more pronounced in left lung transplants.MethodsUsing the United Network for Organ Sharing registry, we conducted a retrospective cohort study of 5,585 adults who underwent lung transplantation for COPD from May 4, 2005 to June 30, 2017. Subjects were followed until March 2019. Post-transplant survival was compared using Cox proportional hazards and Royston and Parmar's flexible parametric survival models. We adjusted for donor and recipient factors with known or plausible associations with survival.ResultsLung transplant recipients who received a left single lung transplant for COPD had an increased risk of post-transplant death when compared with those who received a right single lung transplant for COPD (hazard ratio [HR]: 1.24, 95% CI: 1.08-1.48, p = 0.002). Survival did not differ significantly between double lung transplant and right single lung transplant recipients (HR: 0.88, 95% CI: 0.77-1.02, p = 0.086). Adjusted 5-year survival was 57.8% (95% CI: 55.7-60.1) for double lung recipients, 56.7% (95% CI: 55.4-58.0) for right single lung recipients, and 50.9% (95% CI: 47.2-55.0) for left single lung recipients.ConclusionsIn COPD, right single lung transplantation was associated with improved post-transplant survival compared with left single lung transplantation, and no significant difference in post-transplant survival compared with double lung transplantation was found. In light of the ongoing donor lung shortage, preferential allocation of right single lungs to patients with COPD should be considered.
Project description:Conventional orthotopic implantation of left liver grafts is technically demanding and requires consideration of limited space and vascular complications. The study proposed a modified approach termed "left at right" liver transplantation (LAR-LT), wherein left liver grafts were rotated and implanted in right subphrenic spaces. The selection of recipients for this approach is based on the measurement of the right subphrenic space width and left liver graft length, in which a rotated left liver graft could be comfortably placed in the right subphrenic space. A total of 36 recipients who had undergone LAR-LT between July 2006 and December 2017 were retrospectively reviewed. None of recipients died of complications related to this approach immediately after operation. All grafts showed remarkable increment in liver volume and bi-directional regeneration to fit well within the right abdominal cavity. Meanwhile, the alignment of the biliary tree in LAR-LT is quite straight, making no difficulty in both anastomosis during operation and dealing with biliary stenosis afterward. As such, long-term outcome of LAR-LT is satisfactory. Keeping in mind certain technical concerns, a heterotopic LAR-LT might be safely applied as an alternative with an easier reconstruction procedure for select patients.
Project description:The morphogenesis of left-right (LR) asymmetry is a crucial phase of organogenesis. In the digestive tract, the development of anatomical asymmetry is first evident in the leftward curvature of the stomach. To elucidate the molecular events that shape this archetypal laterality, we performed transcriptome analyses of the left versus right sides of the developing stomach in frog embryos. Besides the known LR gene pitx2, the only gene found to be expressed asymmetrically throughout all stages of curvature was single-minded 2 (sim2), a Down Syndrome-related transcription factor and homolog of a Drosophila gene (sim) required for LR asymmetric looping of the fly gut. We demonstrate that sim2 functions downstream of LR patterning cues to regulate key cellular properties and behaviors in the left stomach epithelium that drive asymmetric curvature. Our results reveal unexpected convergent cooption of single-minded genes during the evolution of LR asymmetric morphogenesis, and have implications for dose-dependent roles of laterality factors in non-laterality-related birth defects.
Project description:Ex vivo lung perfusion (EVLP) has become a reality as a technique to evaluate and recondition lungs from marginal donors. We report the first case on the use of EVLP followed by separate transplantation in two different centres. The local organ procurement organization proposed the lungs of a 53-year-old non-smoker donor who died for cerebral haemorrhage. P/F ratio was 294 after lung recruitment manoeuvres. Oto score was 10. Two centres accepted the grafts for two single transplantations under the condition of EVLP evaluation. After usual retrieval, the bi-pulmonary block was transferred to Centre 1 and EVLP was run as previously described. At the end of the procedure the two lungs were evaluated separately and both judged suitable for transplantation. After cooling and storage on ice, the block was separated on the back table. The left lung was transplanted in a patient with pulmonary fibrosis at Centre 1; surgery was complicated by cardiac arrhythmias that required several defibrillations. The right lung was transferred on ice to Centre 2, 250 km away from Centre 1, and transplanted in a patient with idiopathic pulmonary fibrosis. Thirty months after transplantations Patient 1 and Patient 2 are both alive, in good clinical conditions. This is the first report of the separate use of lungs after EVLP for non-urgent recipients in two different centres. This experience opens the door to a new allocation model with great potentials on organ shortage. Actually, we demonstrated that the perspective of a 'lung repair centre' is feasible and effective.
Project description:Full-left-full-right split liver transplantation (FSLT) for adult recipients, may increase the availability of liver grafts, reduce waitlist time, and benefit recipients with below-average body weight. However, FSLT may lead to impaired graft and patient survival. This study aims to assess outcomes after FSLT. Five databases were searched to identify studies concerning FSLT. Incidences of complications, graft- and patient survival were assessed. Discrete data were pooled with random-effect models. Graft and patient survival after FSLT were compared with whole liver transplantation (WLT) according to the inverse variance method. Vascular complications were reported in 25/273 patients after FSLT (Pooled proportion: 6.9%, 95%CI: 3.1-10.7%, I2 : 36%). Biliary complications were reported in 84/308 patients after FSLT (Pooled proportion: 25.6%, 95%CI: 19-32%, I2 : 44%). Pooled proportions of graft and patient survival after 3 years follow-up were 72.8% (95%CI: 67.2-78.5, n = 231) and 77.3% (95%CI: 66.7-85.8, n = 331), respectively. Compared with WLT, FSLT was associated with increased graft loss (pooled HR: 2.12, 95%CI: 1.24-3.61, P = 0.006, n = 189) and patient mortality (pooled HR: 1.81, 95%CI: 1.17-2.81, P = 0.008, n = 289). FSLT was associated with high incidences of vascular and biliary complications. Nevertheless, long-term patient and graft survival appear acceptable and justify transplant benefit in selected patients.
Project description:According to a theory of magnitude (ATOM, Walsh, 2003, 2015), the cognitive representations of quantity, time, and space share a general magnitude code. Interestingly though, research has largely ignored the relationship between physical (stimulus) size and spatial (response) location. We conducted two experiments investigating compatibility effects between physical stimulus size and left-right responses. In both experiments, right-handed participants responded to a small or a large square stimulus by pressing a left or a right key. In Experiment 1, size was the relevant stimulus feature and we varied the S-R mapping within participants. Results revealed a strong compatibility effect: Performance was better with the compatible mapping (small-left and large-right) than with the incompatible mapping (large-left and small-right). In Experiment 2, participants responded to stimulus color, which varied independently of stimulus size, by pressing a left or right key. Results showed a congruency effect that mirrored the compatibility effect of Experiment 1. The results of our experiments suggest a strong relationship between the cognitive representation of physical (stimulus) size and response location in right-handers. The findings support the notion of a general magnitude code, as proposed in ATOM.
Project description:Donor safety is crucial for living donor liver transplantation (LDLT), and sufficient liver regeneration significantly affects outcomes of living donors. This study aimed to investigate clinical factors associated with liver regeneration in living donors. The study retrospectively reviewed 380 living donors who underwent liver donation at Chang Gung Memorial Hospital in Linkou. The clinical characteristics and medical parameters of donors were analyzed and compared according to liver donation graft type. There were 355 donors (93.4%) with right hemi-liver donations and 25 donors (6.6%) with left hemi-liver donations. Left hemi-liver donors had a higher body mass index (BMI) and a larger ratio of remnant liver volume (RLV) to total liver volume (TLV). However, the 2 groups showed no significant difference in the liver regeneration ratio. The type of remnant liver (P < .001), RLV/body weight (P = .027), RLV/TLV (P < .001), serum albumin on postoperative day 7 and total bilirubin levels on postoperative day 30 were the most significant factors affecting liver regeneration in living donors. In conclusion, adequate liver regeneration is essential for donor outcome after liver donation. The remnant liver could eventually regenerate to an adequate volume similar to the initial TLV before liver donation. However, the remnant left hemi-liver had a faster growth rate than the remnant right hemi-liver in donors.
Project description:Inherent hemispheric asymmetry is significant for cognition, language and other functions. An understanding of normal brain and asymmetry development in the early period will further the knowledge of how different hemispheres prioritize specific functions, which is still unknown. We analysed the developmental changes in and asymmetry of the proteome in the bilateral frontal lobes of three foetal specimens in the late first trimester of pregnancy (9, 11, 13 gestational weeks). We found that during this period, the difference in expression between gestational weeks increased, and the difference in asymmetric expression decreased. The patterns of protein expression changes in the bilateral frontal lobes were different. Our results show that brain asymmetry can be observed in the early stage. Researchers can use these findings to further investigate the mechanisms of brain asymmetry.