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1.
Cell ; 183(3): 786-801.e19, 2020 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-33125893

RESUMO

Trained immunity, a functional state of myeloid cells, has been proposed as a compelling immune-oncological target. Its efficient induction requires direct engagement of myeloid progenitors in the bone marrow. For this purpose, we developed a bone marrow-avid nanobiologic platform designed specifically to induce trained immunity. We established the potent anti-tumor capabilities of our lead candidate MTP10-HDL in a B16F10 mouse melanoma model. These anti-tumor effects result from trained immunity-induced myelopoiesis caused by epigenetic rewiring of multipotent progenitors in the bone marrow, which overcomes the immunosuppressive tumor microenvironment. Furthermore, MTP10-HDL nanotherapy potentiates checkpoint inhibition in this melanoma model refractory to anti-PD-1 and anti-CTLA-4 therapy. Finally, we determined MTP10-HDL's favorable biodistribution and safety profile in non-human primates. In conclusion, we show that rationally designed nanobiologics can promote trained immunity and elicit a durable anti-tumor response either as a monotherapy or in combination with checkpoint inhibitor drugs.


Assuntos
Inibidores de Checkpoint Imunológico/uso terapêutico , Imunidade , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/patologia , Nanotecnologia , Acetilmuramil-Alanil-Isoglutamina/metabolismo , Animais , Comportamento Animal , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Proliferação de Células/efeitos dos fármacos , Colesterol/metabolismo , Feminino , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Inibidores de Checkpoint Imunológico/farmacologia , Imunidade/efeitos dos fármacos , Imunoterapia , Lipoproteínas HDL/metabolismo , Camundongos Endogâmicos C57BL , Primatas , Distribuição Tecidual/efeitos dos fármacos , Microambiente Tumoral/efeitos dos fármacos
2.
Cell ; 150(6): 1135-46, 2012 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-22980977

RESUMO

DNA methylation at the 5 position of cytosine (5-mC) is a key epigenetic mark that is critical for various biological and pathological processes. 5-mC can be converted to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation (TET) family of DNA hydroxylases. Here, we report that "loss of 5-hmC" is an epigenetic hallmark of melanoma, with diagnostic and prognostic implications. Genome-wide mapping of 5-hmC reveals loss of the 5-hmC landscape in the melanoma epigenome. We show that downregulation of isocitrate dehydrogenase 2 (IDH2) and TET family enzymes is likely one of the mechanisms underlying 5-hmC loss in melanoma. Rebuilding the 5-hmC landscape in melanoma cells by reintroducing active TET2 or IDH2 suppresses melanoma growth and increases tumor-free survival in animal models. Thus, our study reveals a critical function of 5-hmC in melanoma development and directly links the IDH and TET activity-dependent epigenetic pathway to 5-hmC-mediated suppression of melanoma progression, suggesting a new strategy for epigenetic cancer therapy.


Assuntos
Citosina/análogos & derivados , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Melanoma/genética , Nevo/genética , 5-Metilcitosina/análogos & derivados , Citosina/metabolismo , Proteínas de Ligação a DNA/genética , Dioxigenases , Estudo de Associação Genômica Ampla , Humanos , Isocitrato Desidrogenase/genética , Melanócitos/metabolismo , Melanoma/patologia , Nevo/patologia , Proteínas Proto-Oncogênicas/genética
3.
Brain ; 147(6): 2069-2084, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38763511

RESUMO

The peroxisomal disease adrenoleukodystrophy (X-ALD) is caused by loss of the transporter of very-long-chain fatty acids (VLCFAs), ABCD1. An excess of VLCFAs disrupts essential homeostatic functions crucial for axonal maintenance, including redox metabolism, glycolysis and mitochondrial respiration. As mitochondrial function and morphology are intertwined, we set out to investigate the role of mitochondrial dynamics in X-ALD models. Using quantitative 3D transmission electron microscopy, we revealed mitochondrial fragmentation in corticospinal axons in Abcd1- mice. In patient fibroblasts, an excess of VLCFAs triggers mitochondrial fragmentation through the redox-dependent phosphorylation of DRP1 (DRP1S616). The blockade of DRP1-driven fission by the peptide P110 effectively preserved mitochondrial morphology. Furthermore, mRNA inhibition of DRP1 not only prevented mitochondrial fragmentation but also protected axonal health in a Caenorhabditis elegans model of X-ALD, underscoring DRP1 as a potential therapeutic target. Elevated levels of circulating cell-free mtDNA in patients' CSF align this leukodystrophy with primary mitochondrial disorders. Our findings underscore the intricate interplay between peroxisomal dysfunction, mitochondrial dynamics and axonal integrity in X-ALD, shedding light on potential avenues for therapeutic intervention.


Assuntos
Membro 1 da Subfamília D de Transportadores de Cassetes de Ligação de ATP , Adrenoleucodistrofia , Dinaminas , Dinâmica Mitocondrial , Adrenoleucodistrofia/metabolismo , Adrenoleucodistrofia/patologia , Adrenoleucodistrofia/genética , Animais , Dinâmica Mitocondrial/fisiologia , Humanos , Camundongos , Dinaminas/metabolismo , Dinaminas/genética , Membro 1 da Subfamília D de Transportadores de Cassetes de Ligação de ATP/genética , Caenorhabditis elegans , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Axônios/patologia , Axônios/metabolismo , Fibroblastos/metabolismo , Fibroblastos/patologia , Masculino , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Modelos Animais de Doenças , Tratos Piramidais/patologia , Tratos Piramidais/metabolismo , Fragmentos de Peptídeos , GTP Fosfo-Hidrolases
4.
Nano Lett ; 24(19): 5722-5728, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38712788

RESUMO

Quantum dots (QDs) with metal fluoride surface ligands were prepared via reaction with anhydrous oleylammonium fluoride. Carboxylate terminated II-VI QDs underwent carboxylate for fluoride exchange, while InP QDs underwent photochemical acidolysis yielding oleylamine, PH3, and InF3. The final photoluminescence quantum yield (PLQY) reached 83% for InP and near unity for core-shell QDs. Core-only CdS QDs showed dramatic improvements in PLQY, but only after exposure to air. Following etching, the InP QDs were bound by oleylamine ligands that were characterized by the frequency and breadth of the corresponding ν(N-H) bands in the infrared absorption spectrum. The fluoride content (1.6-9.2 nm-2) was measured by titration with chlorotrimethylsilane and compared with the oleylamine content (2.3-5.1 nm-2) supporting the formation of densely covered surfaces. The influence of metal fluoride adsorption on the air stability of QDs is discussed.

5.
Learn Mem ; 31(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38950977

RESUMO

Changes caused by learning that a food is inedible in Aplysia were examined for fast and slow synaptic connections from the buccal ganglia S1 cluster of mechanoafferents to five followers, in response to repeated stimulus trains. Learning affected only fast connections. For these, unique patterns of change were present in each follower, indicating that learning differentially affects the different branches of the mechanoafferents to their followers. In some followers, there were increases in either excitatory or inhibitory connections, and in others, there were decreases. Changes in connectivity resulted from changes in the amplitude of excitation or inhibition, or as a result of the number of connections, or of both. Some followers also exhibited changes in either within or between stimulus train plasticity as a result of learning. In one follower, changes differed from the different areas of the S1 cluster. The patterns of changes in connectivity were consistent with the behavioral changes produced by learning, in that they would produce an increase in the bias to reject or to release food, and a decrease in the likelihood to respond to food.


Assuntos
Aplysia , Gânglios dos Invertebrados , Neurônios Motores , Aplysia/fisiologia , Animais , Neurônios Motores/fisiologia , Gânglios dos Invertebrados/fisiologia , Aprendizagem/fisiologia , Mecanorreceptores/fisiologia , Plasticidade Neuronal/fisiologia , Alimentos , Comportamento Alimentar/fisiologia
6.
Learn Mem ; 31(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38950976

RESUMO

How does repeated stimulation of mechanoafferents affect feeding motor neurons? Monosynaptic connections from a mechanoafferent population in the Aplysia buccal ganglia to five motor followers with different functions were examined during repeated stimulus trains. The mechanoafferents produced both fast and slow synaptic outputs, which could be excitatory or inhibitory. In contrast, other Aplysia mechanoafferents produce only fast excitation on their followers. In addition, patterns of synaptic connections were different to the different motor followers. Some followers received both fast excitation and fast inhibition, whereas others received exclusively fast excitation. All followers showed strong decreases in fast postsynaptic potential (PSP) amplitude within a stimulus train. Fast and slow synaptic connections were of net opposite signs in some followers but not in others. For one follower, synaptic contacts were not uniform from all subareas of the mechanoafferent cluster. Differences in properties of the buccal ganglia mechanoafferents and other Aplysia mechanoafferents may arise because the buccal ganglia neurons innervate the interior of the feeding apparatus, rather than an external surface, and connect to motor neurons for muscles with different motor functions. Fast connection patterns suggest that these synapses may be activated when food slips, biasing the musculature to release food. The largest slow inhibitory synaptic PSPs may contribute to a delay in the onset of the next behavior. Additional functions are also possible.


Assuntos
Aplysia , Comportamento Alimentar , Gânglios dos Invertebrados , Neurônios Motores , Animais , Aplysia/fisiologia , Neurônios Motores/fisiologia , Gânglios dos Invertebrados/fisiologia , Comportamento Alimentar/fisiologia , Mecanorreceptores/fisiologia , Sinapses/fisiologia , Estimulação Física
7.
Plant Mol Biol ; 114(1): 4, 2024 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-38227103

RESUMO

Although many important discoveries have been made regarding the jasmonate signaling pathway, how jasmonate biosynthesis is initiated is still a major unanswered question in the field. Previous evidences suggest that jasmonate biosynthesis is limited by the availability of fatty acid precursor, such as ⍺-linolenic acid (⍺-LA). This indicates that the lipase responsible for releasing α-LA in the chloroplast, where early steps of jasmonate biosynthesis take place, is the key initial step in the jasmonate biosynthetic pathway. Nicotiana benthamiana glycerol lipase A1 (NbGLA1) is homologous to N. attenuata GLA1 (NaGLA1) which has been reported to be a major lipase in leaves for jasmonate biosynthesis. NbGLA1 was studied for its potential usefulness in a species that is more common in laboratories. Virus-induced gene silencing of both NbGLA1 and NbGLA2, another homolog, resulted in more than 80% reduction in jasmonic acid (JA) biosynthesis in wounded leaves. Overexpression of NbGLA1 utilizing an inducible vector system failed to increase JA, indicating that transcriptional induction of NbGLA1 is insufficient to trigger JA biosynthesis. However, co-treatment with wounding in addition to NbGLA1 induction increased JA accumulation several fold higher than the gene expression or wounding alone, indicating an enhancement of the enzyme activity by wounding. Domain-deletion of a 126-bp C-terminal region hypothesized to have regulatory roles increased NbGLA1-induced JA level. Together, the data show NbGLA1 to be a major lipase for wound-induced JA biosynthesis in N. benthamiana leaves and demonstrate the use of inducible promoter-driven construct of NbGLA1 in conjunction with its transient expression in N. benthamiana as a useful system to study its protein function.


Assuntos
Lipase , Nicotiana , Oxilipinas , Nicotiana/genética , Lipase/genética , Cloroplastos , Ciclopentanos , Glicerol
8.
Am J Transplant ; 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39147201

RESUMO

The innate immune system plays an essential role in regulating the immune responses to kidney transplantation, but the mechanisms through which innate immune cells influence long-term graft survival are unclear. The current study highlights the vital role of trained immunity in kidney allograft survival. Trained immunity describes the epigenetic and metabolic changes that innate immune cells undergo following an initial stimulus, allowing them have a stronger inflammatory response to subsequent stimuli. We stimulated healthy peripheral blood mononuclear cells with pretransplant and posttransplant serum of kidney transplant patients and immunosuppressive drugs in an in vitro trained immunity assay and measured tumor necrosis factor and interleukin 6 cytokine levels in the supernatant as a readout for trained immunity. We show that the serum of kidney transplant recipients collected 1 week after transplantation can suppress trained immunity. Importantly, we found that kidney transplant recipients whose serum most strongly suppressed trained immunity rarely experienced graft loss. This suppressive effect of posttransplant serum is likely mediated by previously unreported effects of immunosuppressive drugs. Our findings provide mechanistic insights into the role of innate immunity in kidney allograft survival, uncovering trained immunity as a potential therapeutic target for improving graft survival.

9.
Ann Surg ; 280(4): 604-615, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38916985

RESUMO

OBJECTIVE: To describe the evolution of pancreas transplantation, including improved outcomes and factors associated with improved outcomes over the past 5 decades. BACKGROUND: The world's first successful pancreas transplant was performed in December 1966 at the University of Minnesota. As new modalities for diabetes treatment mature, we must carefully assess the current state of pancreas transplantation to determine its ongoing role in patient care. METHODS: A single-center retrospective review of 2500 pancreas transplants was performed over >50 years in bivariate and multivariable models. Transplants were divided into 6 eras; outcomes are presented for the entire cohort and by era. RESULTS: All measures of patient and graft survival improved progressively through the 6 transplant eras. The overall death-censored pancreas graft half-lives were >35 years for simultaneous pancreas and kidney (SPK), 7.1 years for pancreas after kidney (PAK), and 3.3 years for pancreas transplants alone (PTA). The 10-year death-censored pancreas graft survival rate in the most recent era was 86.9% for SPK recipients, 58.2% for PAK recipients, and 47.6% for PTA. Overall, graft loss was most influenced by patient survival in SPK transplants, whereas graft loss in PAK and PTA recipients was more often due to graft failures. Predictors of improved pancreas graft survival were primary transplants, bladder drainage of exocrine secretions, younger donor age, and shorter preservation time. CONCLUSIONS: Pancreas outcomes have significantly improved over time through sequential, but overlapping, advances in surgical technique, immunosuppressive protocols, reduced preservation time, and the more recent reduction of immune-mediated graft loss.


Assuntos
Sobrevivência de Enxerto , Transplante de Pâncreas , Transplante de Pâncreas/métodos , Humanos , Estudos Retrospectivos , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Transplante de Rim , Resultado do Tratamento , Adolescente , Criança , Adulto Jovem , Taxa de Sobrevida
10.
Ann Surg ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39258375

RESUMO

OBJECTIVE: To investigate the long-term outcomes of patients with combined primary sclerosing cholangitis/inflammatory bowel disease (PSC-IBD) undergoing both liver transplantation (LT) and total abdominal colectomy (TAC). SUMMARY BACKGROUND DATA: The fraction of patients with PSC-IBD that require both LT and TAC is small, thereby limiting significant conclusions regarding long-term outcomes. METHODS: Adult and pediatric patients from nine centers from the US IBD Surgery Collaborative who underwent staged LT and TAC for PSC-IBD were included. Long-term outcomes, including survival, were assessed. RESULTS: Among 127 patients, 66 underwent TAC-before-LT, with a median time from TAC to LT of 7.9 yrs, while 61 underwent LT-before-TAC, with a median time from LT to TAC of 4.4 years. Median patient survival post TAC was significantly worse in those undergoing LT-before-TAC (16.0 yrs vs. 42.6 yrs, P=0.007), while post LT survival was not impacted by the order of TAC and LT (21.6 yrs vs. 22.0 yrs, P=0.81). Patients undergoing TAC for medically refractory disease had a higher incidence of recurrent PSC (rPSC) (P=0.02) and biliary complications (0.09) compared to those undergoing TAC for oncologic indications. Definitive TAC reconstruction with either end ileostomy or ileal-pouch anal anastomosis (IPAA) did not impact post-LT or post-TAC outcomes. CONCLUSIONS: Long term survival in PSC-IBD was contingent upon progression to LT and was not impacted by the need for TAC. PSC-IBD patients undergoing TAC for medically refractory disease had a higher incidence of rPSC and biliary complications. The use of IPAA in PSC-IBD was a viable alternative to end ileostomy.

11.
Ann Surg Oncol ; 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39172301

RESUMO

BACKGROUND: Liver transplantation (LT) is the treatment of choice for end-stage liver disease and certain malignancies such as hepatocellular carcinoma (HCC). Data on the surgical management of de novo or recurrent tumors that develop in the transplanted allograft are limited. This study aimed to investigate the perioperative and long-term outcomes for patients undergoing hepatic resection for de novo or recurrent tumors after liver transplantation. METHODS: The study enrolled adult and pediatric patients from 12 centers across North America who underwent hepatic resection for the treatment of a solid tumor after LT. Perioperative outcomes were assessed as well as recurrence free survival (RFS) and overall survival (OS) for those undergoing resection for HCC. RESULTS: Between 2003 and 2023, 54 patients underwent hepatic resection of solid tumors after LT. For 50 patients (92.6 %), resection of malignant lesions was performed. The most common lesion was HCC (n = 35, 64.8 %), followed by cholangiocarcinoma (n = 6, 11.1 %) and colorectal liver metastases (n = 6, 11.1 %). The majority of the 35 patients underwent resection of HCC did not receive any preoperative therapy (82.9 %) or adjuvant therapy (71.4 %), with resection their only treatment method for HCC. During a median follow-up period of 50.7 months, the median RFS was 21.5 months, and the median OS was 49.6 months. CONCLUSION: Hepatic resection following OLT is safe and associated with morbidity and mortality rates that are comparable to those reported for patients undergoing resection in native livers. Hepatic resection as the primary and often only treatment modality for HCC following LT is associated with acceptable RFS and OS and should be considered in well selected patients.

12.
Immunity ; 42(5): 850-63, 2015 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-25979419

RESUMO

The molecular mechanisms regulating antigen translocation into the cytosol for cross-presentation are under controversial debate, mainly because direct data is lacking. Here, we have provided direct evidence that the activity of the endoplasmic reticulum (ER) translocon protein Sec61 is essential for endosome-to-cytosol translocation. We generated a Sec61-specific intrabody, a crucial tool that trapped Sec61 in the ER and prevented its recruitment into endosomes without influencing Sec61 activity and antigen presentation in the ER. Expression of this ER intrabody inhibited antigen translocation and cross-presentation, demonstrating that endosomal Sec61 indeed mediates antigen transport across endosomal membranes. Moreover, we showed that the recruitment of Sec61 toward endosomes, and hence antigen translocation and cross-presentation, is dependent on dendritic cell activation by Toll-like receptor (TLR) ligands. These data shed light on a long-lasting question regarding antigen cross-presentation and point out a role of the ER-associated degradation machinery in compartments distinct from the ER.


Assuntos
Antígenos/metabolismo , Linfócitos T CD8-Positivos , Apresentação Cruzada/imunologia , Citosol/metabolismo , Endossomos/metabolismo , Proteínas de Membrana/metabolismo , Modelos Biológicos , Animais , Antígenos/imunologia , Linhagem Celular , Citosol/imunologia , Proteínas de Membrana/química , Camundongos , Transporte Proteico , Canais de Translocação SEC
13.
J Inherit Metab Dis ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38973597

RESUMO

The protein encoded by COQ7 is required for CoQ10 synthesis in humans, hydroxylating 3-demethoxyubiquinol (DMQ10) in the second to last steps of the pathway. COQ7 mutations lead to a primary CoQ10 deficiency syndrome associated with a pleiotropic neurological disorder. This study shows the clinical, physiological, and molecular characterization of four new cases of CoQ10 primary deficiency caused by five mutations in COQ7, three of which have not yet been described, inducing mitochondrial dysfunction in all patients. However, the specific combination of the identified variants in each patient generated precise pathophysiological and molecular alterations in fibroblasts, which would explain the differential in vitro response to supplementation therapy. Our results suggest that COQ7 dysfunction could be caused by specific structural changes that affect the interaction with COQ9 required for the DMQ10 presentation to COQ7, the substrate access to the active site, and the maintenance of the active site structure. Remarkably, patients' fibroblasts share transcriptional remodeling, supporting a modification of energy metabolism towards glycolysis, which could be an adaptive mechanism against CoQ10 deficiency. However, transcriptional analysis of mitochondria-associated pathways showed distinct and dramatic differences between patient fibroblasts, which correlated with the extent of pathophysiological and neurological alterations observed in the probands. Overall, this study suggests that the combination of precise genetic diagnostics and the availability of new structural models of human proteins could help explain the origin of phenotypic pleiotropy observed in some genetic diseases and the different responses to available therapies.

14.
Xenotransplantation ; 31(4): e12880, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39185772

RESUMO

OBJECTIVE: To evaluate the clinically relevant anti-CD40 antibody iscalimab for baseline immunosuppression in a preclinical pig-to-rhesus renal xenograft model. SUMMARY BACKGROUND DATA: CD40/CD40L co-stimulation blockade-based immunosuppression has been more successful than calcineurin-based protocols in prolonging xenograft survival in preclinical models. METHODS: GGTA1 knockout/CD55 transgenic pig kidneys were transplanted into rhesus monkeys (n = 6) receiving an iscalimab-based immunosuppressive regimen. RESULTS: Two grafts were lost early (22 and 26 days) because of ectatic donor ureters with otherwise normal histology. The other recipients survived 171, 315, 422, and 439 days with good renal function throughout the posttransplant course. None of the recipients experienced serious infectious morbidity. CONCLUSIONS: It may be reasonable to evaluate an iscalimab-based immunosuppressive regimen in clinical renal xenotransplantation.


Assuntos
Sobrevivência de Enxerto , Xenoenxertos , Imunossupressores , Transplante de Rim , Macaca mulatta , Transplante Heterólogo , Animais , Transplante Heterólogo/métodos , Suínos , Sobrevivência de Enxerto/imunologia , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Rim/métodos , Imunossupressores/farmacologia , Xenoenxertos/imunologia , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Anticorpos Monoclonais Humanizados/uso terapêutico , Anticorpos Monoclonais Humanizados/farmacologia , Animais Geneticamente Modificados , Anticorpos Monoclonais/farmacologia , Humanos , Galactosiltransferases/genética
15.
Clin Transplant ; 38(8): e15386, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39087488

RESUMO

BACKGROUND: Chronic immunosuppression following pancreas transplantation carries significant risk, including posttransplant lymphoproliferative disease (PTLD). We sought to define the incidence, risk factors, and long-term outcomes of PTLD following pancreas transplantation at a single center. METHODS: All adult pancreas transplants between February 1, 1983 and December 31, 2023 at the University of Minnesota were reviewed, including pancreas transplant alone (PTA), simultaneous pancreas-kidney transplants (SPK), and pancreas after kidney transplants (PAK). RESULTS: Among 2353 transplants, 110 cases of PTLD were identified, with an overall incidence of 4.8%. 17.3% were diagnosed within 1 year of transplant, 32.7% were diagnosed within 5 years, and 74 (67.3%) were diagnosed after 5 years. The overall 30-year incidence of PTLD did not differ by transplant type-7.4% for PTA, 14.2% for SPK, and 19.4% for PAK (p = 0.3). In multivariable analyses, older age and Epstein-Barr virus seronegativity were risk factors for PTLD, and PTLD was a risk factor for patient death. PTLD-specific mortality was 32.7%, although recipients with PTLD had similar median posttransplant survival compared to those without PTLD (14.9 year vs. 15.6 year, p = 0.9). CONCLUSIONS: PTLD following pancreas transplantation is associated with significant mortality. Although the incidence of PTLD has decreased over time, a high index of suspicion for PTLD following PTx should remain in EBV-negative recipients.


Assuntos
Sobrevivência de Enxerto , Transtornos Linfoproliferativos , Transplante de Pâncreas , Complicações Pós-Operatórias , Humanos , Transplante de Pâncreas/efeitos adversos , Masculino , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/epidemiologia , Feminino , Adulto , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Seguimentos , Fatores de Risco , Prognóstico , Pessoa de Meia-Idade , Incidência , Taxa de Sobrevida , Estudos Retrospectivos , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/mortalidade , Transplante de Rim/efeitos adversos , Adulto Jovem
16.
Nature ; 559(7713): 236-240, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29995867

RESUMO

Controlled transport of water molecules through membranes and capillaries is important in areas as diverse as water purification and healthcare technologies1-7. Previous attempts to control water permeation through membranes (mainly polymeric ones) have concentrated on modulating the structure of the membrane and the physicochemical properties of its surface by varying the pH, temperature or ionic strength3,8. Electrical control over water transport is an attractive alternative; however, theory and simulations9-14 have often yielded conflicting results, from freezing of water molecules to melting of ice14-16 under an applied electric field. Here we report electrically controlled water permeation through micrometre-thick graphene oxide membranes17-21. Such membranes have previously been shown to exhibit ultrafast permeation of water17,22 and molecular sieving properties18,21, with the potential for industrial-scale production. To achieve electrical control over water permeation, we create conductive filaments in the graphene oxide membranes via controllable electrical breakdown. The electric field that concentrates around these current-carrying filaments ionizes water molecules inside graphene capillaries within the graphene oxide membranes, which impedes water transport. We thus demonstrate precise control of water permeation, from ultrafast permeation to complete blocking. Our work opens up an avenue for developing smart membrane technologies for artificial biological systems, tissue engineering and filtration.

17.
J Med Genet ; 60(4): 406-415, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36243518

RESUMO

BACKGROUND: Schaaf-Yang syndrome (SYS) is caused by truncating mutations in MAGEL2, mapping to the Prader-Willi region (15q11-q13), with an observed phenotype partially overlapping that of Prader-Willi syndrome. MAGEL2 plays a role in retrograde transport and protein recycling regulation. Our aim is to contribute to the characterisation of SYS pathophysiology at clinical, genetic and molecular levels. METHODS: We performed an extensive phenotypic and mutational revision of previously reported patients with SYS. We analysed the secretion levels of amyloid-ß 1-40 peptide (Aß1-40) and performed targeted metabolomic and transcriptomic profiles in fibroblasts of patients with SYS (n=7) compared with controls (n=11). We also transfected cell lines with vectors encoding wild-type (WT) or mutated MAGEL2 to assess stability and subcellular localisation of the truncated protein. RESULTS: Functional studies show significantly decreased levels of secreted Aß1-40 and intracellular glutamine in SYS fibroblasts compared with WT. We also identified 132 differentially expressed genes, including non-coding RNAs (ncRNAs) such as HOTAIR, and many of them related to developmental processes and mitotic mechanisms. The truncated form of MAGEL2 displayed a stability similar to the WT but it was significantly switched to the nucleus, compared with a mainly cytoplasmic distribution of the WT MAGEL2. Based on the updated knowledge, we offer guidelines for the clinical management of patients with SYS. CONCLUSION: A truncated MAGEL2 protein is stable and localises mainly in the nucleus, where it might exert a pathogenic neomorphic effect. Aß1-40 secretion levels and HOTAIR mRNA levels might be promising biomarkers for SYS. Our findings may improve SYS understanding and clinical management.


Assuntos
Síndrome de Prader-Willi , Humanos , Síndrome de Prader-Willi/genética , Fenótipo , Mutação , Proteínas/genética , Biomarcadores
18.
Blood Purif ; 53(2): 107-113, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37926072

RESUMO

INTRODUCTION: Midazolam-based continuous intravenous sedation in patients admitted to the intensive care unit (ICU) was a necessity during the COVID-19 pandemic. However, benzodiazepine-based sedation is associated with a high incidence of benzodiazepine-related delirium and additional days on mechanical ventilation. Due to the requirement of high midazolam doses in combination with the impaired renal clearance (CL) of the pharmacological active metabolite 1-OH-midazolam-glucuronide (10% compared to midazolam), ICU patients with COVID-19 and continuous renal replacement therapy (CRRT) were at risk of unintended prolonged sedation. Several CRRT-related factors may have influenced the delivered CL of midazolam and its metabolites. Therefore, the aim of the study was to identify and describe these CRRT-related factors. METHODS: Pre-filter blood samples and ultrafiltrate samples were collected simultaneously. Midazolam, 1-OH-midazolam, and 1-OH-midazolam-glucuronide plasma samples were analyzed using an UPLC-MS/MS method. The prescribed CRRT dose was corrected for downtime and filter integrity using the urea ratio (urea concentration in effluent/urea concentration plasma). CL of midazolam and its metabolites were calculated with the delivered CRRT dose (corrected for downtime and saturation coefficient [SD]). RESULTS: Three patients on continuous venovenous hemodialysis (CVVHD) and 2 patients on continuous venovenous hemodiafiltration (CVVHDF) were included. Midazolam, 1-OH-midazolam, and 1-OH-midazolam-glucuronide concentrations were 2,849 (0-6,700) µg/L, 153 (0-295) µg/L, and 27,297 (1,727-39,000) µg/L, respectively. The SD was 0.03 (0.02-0.03) for midazolam, 0.05 (0.05-0.06) for 1-OH-midazolam, and 0.33 (0.23-0.43) for 1-OH-midazolam-glucuronide. The delivered CRRT CL was 1.4 (0-1.7) mL/min for midazolam, 2.7 (0-3.5) mL/min for 1-OH-midazolam, and 15.7 (4.0-27.7) mL/min for 1-OH-midazolam-glucuronide. CONCLUSIONS: Midazolam and 1-OH-midazolam were not removed during CVVHD and CVVHDF. However, 1-OH-midazolam-glucuronide was removed reasonably, approximately up to 43%. CRRT modality, filter integrity, and downtime affect this removal. These data imply a personalized titration of midazolam in critically ill patients with renal failure and awareness for the additional sedative effects of its active metabolites.


Assuntos
Injúria Renal Aguda , COVID-19 , Terapia de Substituição Renal Contínua , Humanos , Midazolam/uso terapêutico , Estado Terminal/terapia , Cromatografia Líquida , Glucuronídeos , Pandemias , COVID-19/terapia , Espectrometria de Massas em Tandem , Ureia , Terapia de Substituição Renal
19.
Proc Natl Acad Sci U S A ; 118(28)2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34187879

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic is heterogeneous throughout Africa and threatening millions of lives. Surveillance and short-term modeling forecasts are critical to provide timely information for decisions on control strategies. We created a strategy that helps predict the country-level case occurrences based on cases within or external to a country throughout the entire African continent, parameterized by socioeconomic and geoeconomic variations and the lagged effects of social policy and meteorological history. We observed the effect of the Human Development Index, containment policies, testing capacity, specific humidity, temperature, and landlocked status of countries on the local within-country and external between-country transmission. One-week forecasts of case numbers from the model were driven by the quality of the reported data. Seeking equitable behavioral and social interventions, balanced with coordinated country-specific strategies in infection suppression, should be a continental priority to control the COVID-19 pandemic in Africa.


Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , África/epidemiologia , COVID-19/diagnóstico , COVID-19/prevenção & controle , Previsões , Humanos , Modelos Estatísticos , Política Pública , SARS-CoV-2/isolamento & purificação , Tempo (Meteorologia)
20.
Molecules ; 29(16)2024 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-39202988

RESUMO

PURPOSE: Sodium N-[8-(2-hydroxybenzoyl)amino]caprylate (SNAC) is a well-known penetration enhancer widely used in commercial applications. This study aims to broaden its properties through a novel strategy of converting it into its phenolate salts. The objective is to investigate the synthesis of SNAC phenolate salts, specifically SNAC-choline (SNAC-CH), SNAC-sodium (SNAC-Na), and SNAC-phosphatidylcholine (SNAC-PC), and to explore their potential application in improving the oral absorption of semaglutide. METHODS: The synthesis of SNAC phenolate salts was confirmed through 1H-NMR, FTIR, and an elemental analysis of C, H, N, and O. In vivo testing was conducted to assess the oral delivery of semaglutide using these synthesized SNAC phenolate salts. Pharmacokinetic (PK) values were measured to evaluate the impact on drug absorption. RESULTS: The synthesis of SNAC phenolate salts (SNAC-CH, SNAC-Na, and SNAC-PC) was successfully achieved under appropriate conditions, and their structures were confirmed using analytical techniques such as IR, NMR, and CHN elemental analysis. The paradigm of their use was evaluated through an oral pharmacokinetic (PK) in vivo study using SNAC phenolate salts, which did not impair the original SNAC PK values. This suggests that this strategy holds promise as a potential new effective enhancer for oral absorption. CONCLUSIONS: The utilization of SNAC phenolate salts presents a novel and promising strategy for extending the verity of penetration enhancers' molecules and properties. Synthesizing phenolate salts represents a new chemical strategy that may open new avenues in molecular development. This approach holds future potential to enhance the oral delivery of peptide drugs like semaglutide without compromising therapeutic efficacy. Overall, it offers significant advancements in the field by providing a potential alternative to injectable peptides through oral delivery systems.


Assuntos
Disponibilidade Biológica , Caprilatos , Peptídeos Semelhantes ao Glucagon , Peptídeos Semelhantes ao Glucagon/farmacocinética , Peptídeos Semelhantes ao Glucagon/administração & dosagem , Peptídeos Semelhantes ao Glucagon/química , Administração Oral , Animais , Caprilatos/química , Sais/química , Ratos , Masculino
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