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1.
Clin Transplant ; 38(1): e15208, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38041492

RESUMO

BACKGROUND: End-stage liver disease (ESLD) and end-stage renal disease (ESRD) are prevalent diseases for which the definitive treatment is transplantation. With limited organ supply, strategies to maximize organ availability has led to increasing rates of split liver transplantations for ESLD patients. Therefore, simultaneous split liver and kidney transplantations (SSLK) for patients with ESLD and ESRD could represent a treatment option for comorbid patients. However, current practice and outcomes after SSLK are unknown. METHODS: We aim to report national trends and our experience with patients undergoing SSLK. We performed a retrospective review of the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research file from January 2011-April 2022. Descriptive analysis of preoperative characteristics, postoperative outcomes and actuarial graft and patient survivals are reported. RESULTS: National review of the UNOS transplant registry from 2011-2021 of adult patients undergoing initial transplantation via SSLK demonstrates that this procedure remains uncommon, with only 76 such cases captured in that time. Nevertheless, survival rates at 1, 3, and 5 years remains robust, at 94%, 92%, and 90% for patients overall, 90%, 88%, 88%, for the liver graft, and 93%, 91%, 88% for the kidney graft, respectively. Review of a single center experience with three such patients from 2019-2021 has shown a safe, enduring transplant option with no graft complications seen. CONCLUSIONS: SSLK is both safe and a feasible option to optimize organ supply while allowing recipients to receive quality liver and kidney grafts and should be considered more often by transplant centers going forward.


Assuntos
Doença Hepática Terminal , Falência Renal Crônica , Transplante de Rim , Transplante de Fígado , Adulto , Humanos , Transplante de Rim/efeitos adversos , Transplante de Fígado/efeitos adversos , Falência Renal Crônica/cirurgia , Falência Renal Crônica/etiologia , Doença Hepática Terminal/cirurgia , Estudos Retrospectivos , Rim , Sobrevivência de Enxerto , Resultado do Tratamento
2.
Artif Organs ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39034871

RESUMO

BACKGROUND: Efforts to improve the quality of marginal grafts for transplantation are essential. Machine perfusion preservation appears as a promising solution. METHODS: The United Network for Organ Sharing (UNOS) database was queried for deceased liver donor records between 2016 and 2022. The primary outcome of interest was the organ nonutilization rate. Long-term graft and patient survival among extended criteria donors (ECDs) were also analyzed. RESULTS: During the study period, out of 54 578 liver grafts recovered for transplant, 5085 (9.3%) were nonutilized. Multivariable analysis identified normothermic machine perfusion (NMP) preservation as the only predictor associated with a reduction in graft nonutilization (OR = 0.12; 95% CI = 0.06-0.023, p < 0.001). Further analysis of ECD grafts that were transplanted revealed comparable 1-,2- and 3-years graft survival (89%/88%/82% vs. 90%/85%/81%, p = 0.60), and patient survival (92%/91%/84% vs. 92%/88%/84%, p = 0.65) between grafts that underwent MP vs. those who did not, respectively. CONCLUSIONS: Liver nonutilization rates in the United States are at an all-time high. Available data, most likely including cases from clinical trials, showed that NMP reduced the odds of organ nonutilization by 12% among the entire deceased donor pool and by 16% among grafts from ECD. Collective efforts and further evidence reflecting day-to-day clinical practice are needed to fully reach the potential of MP for liver transplant.

3.
Clin Transplant ; 37(11): e15099, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37589889

RESUMO

BACKGROUND: Living donor liver transplantation (LDLT) in the elderly population is currently not well studied. There are single-center studies indicating that patient age should not be a barrier to LDLT, with similar outcomes compared to younger recipients. METHODS: Using UNOS/STAR data from 2010 to 2022 we retrospectively analyzed patients ≥70 years old receiving a living donor graft (LDLT ≥70y group) versus a deceased donor graft (DDLT ≥70y group). In addition, we compared recipients ≥70 years old undergoing LDLT versus patients 18-69 years old also undergoing LDLT. Donor and recipient baseline characteristics, as well as postoperative outcomes including graft and patient survival were analyzed and compared between groups. RESULTS: Recipients in the LDLT ≥70y group showed less disease burden and spent significantly less time on the waitlist when compared to recipients in the DDLT ≥70y group (102 [49-201] days versus 170 [36-336] days) respectively; p = .004. With the exception of a longer length of stay (LOS) in the LDLT ≥70y group (p ≤ .001), postoperative outcomes were comparable with recipients in the DDLT ≥70y group, including similar graft and patient survival rates at 1-, 3-, and 5-years. When compared to younger recipients of a graft from a living donor, patients in the LDLT ≥70y group had similar post-transplant functional status, re-transplant rates and similar causes contributing to graft failure. However, significantly lower graft and patient survival rates were observed. CONCLUSION: LDLT for recipients aged 70 or greater represents a faster access to transplantation in a safe and feasible manner when compared to similar- aged recipients undergoing DDLT.


Assuntos
Transplante de Fígado , Humanos , Idoso , Estados Unidos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores Vivos , Tempo de Internação , Sobrevivência de Enxerto , Resultado do Tratamento
4.
Plant J ; 108(1): 120-133, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34288193

RESUMO

Thioredoxins (TRXs) are well-known redox signalling players, which carry out post-translational modifications in target proteins. Chloroplast TRXs are divided into different types and have central roles in light energy uptake and the regulation of primary metabolism. The isoforms TRX m1, m2, and m4 from Arabidopsis thaliana are considered functionally related. Knowing their key position in the hub of plant metabolism, we hypothesized that the impairment of the TRX m signalling would not only have harmful consequences on chloroplast metabolism but also at different levels of plant development. To uncover the physiological and developmental processes that depend on TRX m signalling, we carried out a comprehensive study of Arabidopsis single, double, and triple mutants defective in the TRX m1, m2, and m4 proteins. As light and redox signalling are closely linked, we investigated the response to high light (HL) of the plants that are gradually compromised in TRX m signalling. We provide experimental evidence relating the lack of TRX m and the appearance of novel phenotypic features concerning mesophyll structure, stomata biogenesis, and stomatal conductance. We also report new data indicating that the isoforms of TRX m fine-tune the response to HL, including the accumulation of the protective pigment anthocyanin. These results reveal novel signalling functions for the TRX m and underline their importance for plant growth and fulfilment of the acclimation/response to HL conditions.


Assuntos
Arabidopsis/fisiologia , Tiorredoxinas de Cloroplastos/metabolismo , Transdução de Sinais , Antocianinas/metabolismo , Arabidopsis/genética , Arabidopsis/efeitos da radiação , Clorofila/metabolismo , Cloroplastos/metabolismo , Fluorescência , Luz , Mutação , Oxirredução , Folhas de Planta/genética , Folhas de Planta/fisiologia , Folhas de Planta/efeitos da radiação , Estômatos de Plantas/genética , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Isoformas de Proteínas
5.
Clin Transplant ; 36(10): e14687, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35468235

RESUMO

BACKGROUND: The timing of removing abdominal drains, central venous catheters (CVC), and urinary catheters (UC) on post liver transplantation (LT) outcomes is not well elucidated. OBJECTIVES: To provide international expert panel recommendations and guidelines on time of drain and catheter removal as a part of an ERAS protocol to reduce the length of hospital stay and enhance recovery. METHODS: Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel. Papers considered were those reporting one or more outcomes of interest related to drainage and line removal in the setting of LT. POSPERO Protocol ID: CRD42021238349 RESULTS: On analyzing five relevant studies pertaining to drains in patients undergoing LT (four retrospectives and one prospective), the length of hospital and/or ICU stay was similar or shorter, and postoperative morbidity and mortality were lower in those without drains. No studies pertaining specifically to the time of removal of drains, CVC's, or UC's in LT were found. Studies in patients undergoing major abdominal surgery or hepatectomies recommend early removal of CVC and UC to reduce catheter-associated infections. CONCLUSIONS: Based more on expert recommendation, we propose that abdominal drains, if placed during LT, should be removed by postoperative day 5 after LT, based on quantity and fluid characteristics (Quality of Evidence; Low to Moderate | Grade of Recommendation; Strong). Larger studies are needed to more reliably determine indications for early drain and line removal in an ERAS protocol setting.


Assuntos
Transplante de Fígado , Humanos , Tempo de Internação , Estudos Prospectivos , Drenagem/métodos , Remoção de Dispositivo
6.
Clin Transplant ; 36(12): e14801, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35997030

RESUMO

INTRODUCTION: Split liver transplantation (SLT) emerged due to its potential to contribute to the organ pool and reduce organ shortage. However, SLT is technically challenging and has been associated with higher rates of postoperative complications leading to concerns about graft and patient survival. Moreover, there are few studies on matched-pair adult recipients of SLT and whole-liver transplant (WLT), with conflicting results. METHODS: This retrospective study analyze outcomes among adults who underwent SLT at our institution from 2010 to 2019. A 1:1 propensity score matching analysis was performed based on important donor and recipient variables. Baseline characteristics and postoperative outcomes were analyzed and compared between groups. Actuarial graft and patient survival were analyzed by KM curves. RESULTS: Out of 592 adults receiving a LT in our institution, 21 SLT adult recipients were identified and matched with 21 adults undergoing WLT. As expected donor age was significantly lower in SLT recipients (16 (15-22) vs. 32 (17-47), P = .012). Additional donor characteristics, including anthropometrics, and ischemic times were similar between groups. Baseline recipient characteristics and postoperative outcomes, including length of stay, vascular complications, biliary complications, and re-transplantation were comparable between SLT and WLT recipients. Graft (95/95/95 vs. 100/94/94, P = .98) and patient (100/100/100 vs. 100/94/94, P = .30) survival at 1-, 3-, 5-years, were similar between the SLT- and WLT group, respectively. CONCLUSION: Split liver transplantation has the potential to increase the availability of organs for adult recipients without compromising individual outcomes.


Assuntos
Transplante de Fígado , Adulto , Humanos , Estudos Retrospectivos , Pontuação de Propensão , Resultado do Tratamento , Doadores de Tecidos , Sobrevivência de Enxerto
7.
Transpl Int ; 36: 10437, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35391900

RESUMO

Split and LDLT in pediatric patients have the potential to decrease wait times and waitlist mortality. Using UNOS-STAR data, we compared outcomes of pediatric patients undergoing LDLT and SLT using LLS grafts. The baseline characteristics and post-operative outcomes were compared between groups. Actuarial graft and patient survival were analyzed with Kaplan-Meier curves. Between 2010 and 2019, 911 pediatric LT were included in the analysis (LD graft group, n = 508, split graft group, n = 403). LD graft recipients spent more time on the waitlist vs. the split graft group (60 (22-138) days vs. 46 (16-108) days; p = 0.007). LD recipients had a lower rate of graft failure, found in 9.8% of patients compared with 14.6% in the split graft group (p = 0.02). HAT was the most common graft failure cause, with similar rates. Graft and patient survival at 1-, 3-, and 5-years was comparable between LDLT and SLT. In subgroup analyses, patients with biliary atresia, those ≤10 kg or ≤10 years old receiving an LD graft showed improved graft survival. In conclusion, LDLT is associated with a lower rate of graft failure in pediatric patients. The use of LLS regardless of the type of donor is a safe way to facilitate access to transplantation to pediatric patients with acceptable short and long-term outcomes.


Assuntos
Transplante de Fígado , Criança , Sobrevivência de Enxerto , Humanos , Doadores Vivos , Estudos Retrospectivos , Resultado do Tratamento
8.
Pediatr Transplant ; 26(8): e14159, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34687473

RESUMO

BACKGROUND: Split liver transplantation (SLT) is a strategy to address organ shortage, but is a technically more demanding procedure than whole graft liver transplantation (LT). We aimed to determine the outcomes following SLT in adult recipients as well as to highlight the impact that having a pediatric LT program has on SLT implementation. METHODS: All SLTs conducted at a single-center from 2010 to 2019 were identified. Patient data was obtained through retrospective review of the electronic medical record. Kaplan-Meier analysis assessed primary outcomes of 1-,3-, and 5-year graft and patient survival. RESULTS: We identified 37 SLTs performed at our institution from 2010 to 2019. Twenty-four donated livers resulted in 21 extended right lobes and 16 left lateral segments for adults and pediatrics recipients, respectively. Eighty-one percent (30/37) of the SLTs were performed after introduction of the combined pediatric program in 2016. 13/24 donor livers were split with both grafts allocated and used at our institution and 92% occurred after introduction of the pediatric program. Graft survival rates at 1-, 3-, and 5-years were 94% in adult recipients and 100% for all time periods in pediatric recipients. Actuarial post-transplant patient survival was 100% at 1-, 3-, and 5-years in both. CONCLUSIONS: The introduction of a pediatric liver transplantation program resulted in more than a fourfold increase in the number of SLTs performed at our center. Increase in allocation and use of both grafts at our institution was also seen.


Assuntos
Transplante de Fígado , Pediatria , Obtenção de Tecidos e Órgãos , Humanos , Criança , Adulto , Transplante de Fígado/métodos , Resultado do Tratamento , Sobrevivência de Enxerto , Fígado , Estudos Retrospectivos
9.
Liver Transpl ; 27(10): 1412-1423, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34053171

RESUMO

Maximizing liver graft volume benefits the living donor liver recipient. Whether maximizing graft volume negatively impacts living donor recovery and outcomes remains controversial. Patient randomization between right and left hepatectomy has not been possible due to anatomic constraints; however, a number of published, nonrandomized observational studies summarize donor outcomes between 2 anatomic living donor hepatectomies. This meta-analysis compares donor-specific outcomes after right versus left living donor hepatectomy. Systematic searches were performed via PubMed, Cochrane, ResearchGate, and Google Scholar databases to identify relevant studies between January 2005 and November 2019. The primary outcomes compared overall morbidity and incidence of severe complications (Clavien-Dindo >III) between right and left hepatectomy in donors after liver donation. Random effects meta-analysis was performed to derive summary risk estimates of outcomes. A total of 33 studies (3 prospective and 30 retrospective cohort) were used to identify 7649 pooled patients (5993 right hepatectomy and 1027 left hepatectomy). Proportion of donors who developed postoperative complications did not significantly differ after right hepatectomy (0.33; 95% confidence interval [CI], 0.27-0.40) and left hepatectomy (0.23; 95% CI, 0.17-0.29; P = 0.19). The overall risk ratio (RR) did not differ between right and left hepatectomy (RR, 1.16; 95% CI, 0.83-1.63; P = 0.36). The relative risk for a donor to develop severe complications showed no differences by hepatectomy side (Incidence rate ratio, 0.97; 95% CI, 0.67-1.40; P = 0.86). There is no evidence that the overall morbidity differs between right and left lobe donors. Publication bias reflects institutional and surgeon variation. A prospective, standardized, multi-institutional study would help quantify the burden of donor complications after liver donation.


Assuntos
Hepatectomia , Transplante de Fígado , Hepatectomia/efeitos adversos , Humanos , Fígado , Transplante de Fígado/efeitos adversos , Doadores Vivos , Morbidade , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Estudos Retrospectivos
10.
Cell Mol Life Sci ; 77(9): 1827-1845, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31372684

RESUMO

Leishmaniasis comprises a group of neglected diseases caused by the protozoan parasite Leishmania spp. As is the case for other trypanosomatid parasites, Leishmania is auxotrophic for heme and must scavenge this essential compound from its human host. In mammals, the SLC transporter FLVCR2 mediates heme import across the plasma membrane. Herein we identify and characterize Leishmania major FLVCRb (LmFLVCRb), the first member of the FLVCR family studied in a non-metazoan organism. This protein localizes to the plasma membrane of the parasite and is able to bind heme. LmFLVCRb levels in Leishmania, which are modulated by overexpression thereof or the abrogation of an LmFLVCRb allele, correlate with the ability of the parasite to take up porphyrins. Moreover, injection of LmFLVCRb cRNA to Xenopus laevis oocytes provides these cells with the ability to take up heme. This process is temperature dependent, requires monovalent ions and is inhibited at basic pH, characteristics shared by the uptake of heme by Leishmania parasites. Interestingly, LmFLVCRb is essential as CRISPR/Cas9-mediated knockout parasites were only obtained in the presence of an episomal copy of the gene. In addition, deletion of just one of the alleles of the LmFLVCRb gene markedly impairs parasite replication as intracellular amastigotes as well as its virulence in an in vivo model of cutaneous leishmaniasis. Collectively, these results show that Leishmania parasites can rescue heme through plasma membrane transporter LFLVCRb, which could constitute a novel target for therapeutic intervention against Leishmania and probably other trypanosomatid parasites in which FLVCR genes are also present.


Assuntos
Heme/metabolismo , Leishmania major/metabolismo , Leishmaniose/parasitologia , Macrófagos/parasitologia , Proteínas de Membrana Transportadoras/metabolismo , Porfirinas/metabolismo , Proteínas de Protozoários/metabolismo , Receptores Virais/metabolismo , Sequência de Aminoácidos , Animais , Transporte Biológico , Membrana Celular/metabolismo , Células Cultivadas , Humanos , Leishmania major/patogenicidade , Leishmaniose/metabolismo , Macrófagos/metabolismo , Proteínas de Membrana Transportadoras/genética , Oócitos/metabolismo , Oócitos/parasitologia , Proteínas de Protozoários/genética , Receptores Virais/genética , Homologia de Sequência , Virulência , Xenopus laevis
11.
FASEB J ; 33(12): 13367-13385, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31553893

RESUMO

Heme is an essential molecule synthetized through a broadly conserved 8-step route that has been lost in trypanosomatid parasites. Interestingly, Leishmania reacquired by horizontal gene transfer from γ-proteobacteria the genes coding for the last 3 enzymes of the pathway. Here we show that intracellular amastigotes of Leishmania major can scavenge heme precursors from the host cell to fulfill their heme requirements, demonstrating the functionality of this partial pathway. To dissect its role throughout the L. major life cycle, the significance of L. major ferrochelatase (LmFeCH), the terminal enzyme of the route, was evaluated. LmFeCH expression in a heterologous system demonstrated its activity. Knockout promastigotes lacking lmfech were not able to use the ferrochelatase substrate protoporphyrin IX as a source of heme. In vivo infection of Phlebotomus perniciosus with knockout promastigotes shows that LmFeCH is not required for their development in the sandfly. In contrast, the replication of intracellular amastigotes was hampered in vitro by the deletion of lmfech. However, LmFeCH-/- parasites produced disease in a cutaneous leishmaniasis murine model in a similar way as control parasites. Therefore, although L. major can synthesize de novo heme from macrophage precursors, this activity is dispensable being an unsuited target for leishmaniasis treatment.-Orrego, L. M., Cabello-Donayre, M., Vargas, P., Martínez-García, M., Sánchez, C., Pineda-Molina, E., Jiménez, M., Molina, R., Pérez-Victoria, J. M. Heme synthesis through the life cycle of the heme auxotrophic parasite Leishmania major.


Assuntos
Ferroquelatase/metabolismo , Heme/biossíntese , Leishmania major/crescimento & desenvolvimento , Leishmaniose Cutânea/metabolismo , Proteínas de Protozoários/metabolismo , Psychodidae/metabolismo , Virulência , Sequência de Aminoácidos , Animais , Coproporfirinogênio Oxidase/metabolismo , Feminino , Ferroquelatase/química , Ferroquelatase/genética , Leishmaniose Cutânea/parasitologia , Macrófagos/metabolismo , Macrófagos/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Conformação Proteica , Protoporfirinogênio Oxidase/metabolismo , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , Psychodidae/parasitologia , Homologia de Sequência
14.
J Exp Bot ; 67(22): 6253-6265, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27799283

RESUMO

Arbuscular mycorrhizal symbioses that involve most plants and Glomeromycota fungi are integral and functional parts of plant roots. In these associations, the fungi not only colonize the root cortex but also maintain an extensive network of hyphae that extend out of the root into the surrounding environment. These external hyphae contribute to plant uptake of low mobility nutrients, such as P, Zn, and Cu. Besides improving plant mineral nutrition, arbuscular mycorrhizal fungi (AMF) can alleviate heavy metal (HM) toxicity to their host plants. HMs, such as Cu, Zn, Fe, and Mn, play essential roles in many biological processes but are toxic when present in excess. This makes their transport and homeostatic control of particular importance to all living organisms. AMF play an important role in modulating plant HM acquisition in a wide range of soil metal concentrations and have been considered to be a key element in the improvement of micronutrient concentrations in crops and in the phytoremediation of polluted soils. In the present review, we provide an overview of the contribution of AMF to plant HM acquisition and performance under deficient and toxic HM conditions, and summarize current knowledge of metal homeostasis mechanisms in arbuscular mycorrhizas.


Assuntos
Metais Pesados/metabolismo , Transporte Biológico , Homeostase , Metais Pesados/toxicidade , Micorrizas/metabolismo , Plantas/metabolismo , Plantas/microbiologia
15.
Appl Environ Microbiol ; 81(21): 7533-45, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26296726

RESUMO

Motility plays an essential role in bacterial fitness and colonization in the plant environment, since it favors nutrient acquisition and avoidance of toxic substances, successful competition with other microorganisms, the ability to locate the preferred hosts, access to optimal sites within them, and dispersal in the environment during the course of transmission. In this work, we have observed that the mutation of the flagellar master regulatory gene, fleQ, alters bacterial surface motility and biosurfactant production, uncovering a new type of motility for Pseudomonas syringae pv. tomato DC3000 on semisolid surfaces. We present evidence that P. syringae pv. tomato DC3000 moves over semisolid surfaces by using at least two different types of motility, namely, swarming, which depends on the presence of flagella and syringafactin, a biosurfactant produced by this strain, and a flagellum-independent surface spreading or sliding, which also requires syringafactin. We also show that FleQ activates flagellum synthesis and negatively regulates syringafactin production in P. syringae pv. tomato DC3000. Finally, it was surprising to observe that mutants lacking flagella or syringafactin were as virulent as the wild type, and only the simultaneous loss of both flagella and syringafactin impairs the ability of P. syringae pv. tomato DC3000 to colonize tomato host plants and cause disease.


Assuntos
Proteínas de Bactérias/genética , Flagelos/fisiologia , Biogênese de Organelas , Pseudomonas syringae/fisiologia , Tensoativos/metabolismo , Transativadores/genética , Proteínas de Bactérias/metabolismo , Flagelos/genética , Locomoção , Solanum lycopersicum , Mutação , Doenças das Plantas/microbiologia , Pseudomonas syringae/genética , Transativadores/metabolismo , Virulência
16.
Updates Surg ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526699

RESUMO

Decades of experience supports LDLT as a favorable strategy to reduce waitlist mortality. The multiple regenerative pathways of hepatocytes and other hepatic cells justify the rationale behind it. Nonetheless, living liver donation is still underused and its broader implementation is challenging, mostly due to variability in practices leading to concerns related to donor safety. A non-systematic literature search was conducted for peer-reviewed original articles related to pre-operative evaluation of living liver donor candidates. Eligible studies were synthesized upon consensus for discussion in this up-to-date review. Review of the literature demonstrate that the importance of preoperative assessment of vascular, biliary and liver volume to ensure donor safety and adequate surgical planning for graft procurement is widely recognized. Moreover, data indicates that anatomic variants in vascular and biliary systems in healthy donors are common, present in up to 50% of the population. Therefore, comprehensive mapping and visualizations of each component is needed. Different imaging modalities are reported across practices and are discussed in detail. Lastly, assessment of liver volume must take into account several technical and donor factors that increase the chances of errors in volume estimation, which occurs in up to 10% of the cases. Experience suggests that maximizing donor safety and lessening their risks is a result of integrated experience between hepatobiliary and transplant surgery, along with multidisciplinary efforts in performing a comprehensive pre-operative donor assessment. Although technical advances have increased the accuracy of volume estimation, over- or under-estimation remains a challenge that needs further attention.

17.
Front Plant Sci ; 15: 1430695, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39114470

RESUMO

Background: Seeds of woody plant species, such as those in the Acer genus like Norway maple (Acer platanoides L.) and sycamore (Acer pseudoplatanus L.), exhibit unique physiological traits and responses to environmental stress. Thioredoxins (Trxs) play a central role in the redox regulation of cells, interacting with other redox-active proteins such as peroxiredoxins (Prxs), and contributing to plant growth, development, and responses to biotic and abiotic stresses. However, there is limited understanding of potential variations in this system between seeds categorized as recalcitrant and orthodox, which could provide insights into adaptive strategies. Methods: Using proteomic analysis and DDA methods we investigated the Trx-h1 target proteins in seed axes. We complemented the results of the proteomic analysis with gene expression analysis of the Trx-h1, 1-Cys-Prx, and TrxR NTRA genes in the embryonic axes of maturing, mature, and stored seeds from two Acer species. Results and discussion: The expression of Trx-h1 and TrxR NTRA throughout seed maturation in both species was low. The expression of 1-Cys-Prx remained relatively stable throughout seed maturation. In stored seeds, the expression levels were minimal, with slightly higher levels in sycamore seeds, which may confirm that recalcitrant seeds remain metabolically active during storage. A library of 289 proteins interacting with Trx-h1 was constructed, comprising 68 from Norway maple and 221 from sycamore, with distinct profiles in each seed category. Recalcitrant seed axes displayed a wide array of metabolic, stress response, and signaling proteins, suggesting sustained metabolic activity during storage and the need to address oxidative stress. Conversely, the orthodox seed axes presented a protein profile, reflecting efficient metabolic shutdown, which contributes to their extended viability. The results of the study provide new insights into seed viability and storage longevity mechanisms. They enhance the understanding of seed biology and lay the foundation for further evolutionary research on seeds of different categories.

18.
Sci Rep ; 14(1): 14364, 2024 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-38906940

RESUMO

Despite many interventions, science education remains highly inequitable throughout the world. Internet-enabled experimental learning has the potential to reach underserved communities and increase the diversity of the scientific workforce. Here, we demonstrate the use of lab-on-a-chip (LoC) technologies to expose Latinx life science undergraduate students to introductory concepts of computer programming by taking advantage of open-loop cloud-integrated LoCs. We developed a context-aware curriculum to train students at over 8000 km from the experimental site. Through this curriculum, the students completed an assignment testing bacteria contamination in water using LoCs. We showed that this approach was sufficient to reduce the students' fear of programming and increase their interest in continuing careers with a computer science component. Altogether, we conclude that LoC-based internet-enabled learning can become a powerful tool to train Latinx students and increase the diversity in STEM.


Assuntos
Internet , Estudantes , Humanos , Dispositivos Lab-On-A-Chip , Currículo , Disciplinas das Ciências Biológicas/educação
19.
Transplant Rev (Orlando) ; 37(1): 100750, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36878038

RESUMO

Living Donor Liver Transplantation (LDLT) emerged as an alternative treatment option for patients with end-stage liver disease waiting for an organ from a deceased donor. In addition to allowing for a faster access to transplantation, LDLT provides improved recipient outcomes when compared to deceased donor LT. However, it represents a more complex and demanding procedure for the transplant surgeon. In addition to a comprehensive preoperative donor assessment and stringent technical considerations during the donor hepatectomy to ensure upmost donor safety, the recipient procedure also comes with intrinsic challenges during LDLT. A proper approach during both procedures will result in favorable donor and recipient's outcomes. Hence, it is critical for the transplant surgeon to know how to overcome such technical challenges and avoid deleterious complications. One of the most feared complications following LDLT is small-for-size syndrome (SFSS). Although, surgical advances and deeper understanding of the pathophysiology behind SFSS has allowed for a safer implementation of LDLT, there is currently no consensus on the best strategy to prevent or manage this complication. Therefore, we aim to review current practices in technically challenging situations during LDLT, with a particular focus on management of small grafts and venous outflow reconstructions, as they possess one of the biggest technical challenges faced during LDLT.


Assuntos
Doença Hepática Terminal , Transplante de Fígado , Humanos , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Doadores Vivos , Circulação Hepática/fisiologia , Resultado do Tratamento
20.
Front Transplant ; 2: 1163539, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38993846

RESUMO

Introduction: Following procurement, the liver graft is exposed to an ischemic period that triggers several pathophysiologic changes in response to oxygen deprivation. Therefore, the goal during organ preservation is to attenuate such response and provide an adequate environment that prepares the graft for its metabolic reactivation following implantation. This has been widely achieved via static cold storage preservation, where the maintenance of the graft using cold preservation solutions reduce its metabolic activity and confer cytoprotection until transplantation. However, despite being the gold standard for organ preservation, static cold storage holds several disadvantages. In addition, the ongoing organ shortage has led to the use of unconventional grafts that could benefit from therapies pre-transplant. Organ preservation via machine perfusion systems appears as a promising solution to address both. Methods: Here, we aim to present a state-of-the-art narrative review regarding liver graft modification options using machine perfusion systems in combination with adjuvant strategies including immunomodulation, gene therapy and pharmacotherapy. Results: Available reports are scarce and mostly on experimental animal models. Most of the literature reflects the use of normothermic or subnormothermic machine perfusion devices given that these particular type of machine allows for a metabolically active organ, and therefore facilitates its modification. Although limited, promising findings in available reports suggest that organ preservation using machine perfusion system when combined with alternative therapies can be feasible and safe strategies for graft modification. Discussion: Further research on clinical settings are needed to better elucidate the true effect of graft modification pre-transplant on short- and long-term graft and patient survival. There is a long way ahead to develop guidelines and approve these novel therapies for clinical practice. However, the path looks promising.

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