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1.
N Z Med J ; 137(1594): 43-53, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38696831

RESUMO

AIM: Bariatric surgery is an effective tool for weight loss and for improving weight related co-morbidities. Changes in medication usage after a silastic ring laparoscopic Roux-en-Y gastric bypass (SR-LRYGB) compared with laparoscopic sleeve gastrectomy (LSG) are unknown. METHODS: This was a single-centre, double-blind, randomised controlled trial. Patients were randomised to either SR-LRYGB or LSG. A medication history was obtained at regular follow-up intervals, and mean numbers of prescribed medications were analysed over 5 years. Poisson regression and generalised estimating equations were used to test for statistically significant changes in usage. RESULTS: After eight patients were lost to follow-up, data from 52 patients in each group were available for analysis. There was no difference between the SR-LRYGB or LSG groups in the number of medications prescribed, with the exception of oral glucose-lowering medications, where there was a greater decrease after SR-LRYGB compared to LSG (79% vs 55% respectively) from baseline to 5 years. At 5 years, total medication prescribed was down 10% from pre-operative levels. Prescribed insulin decreased by 72%, and cardiovascular medication decreased by 56% compared to baseline. Prescriptions for analgesia increased by 50%, psychiatric medications by 133% and proton-pump inhibitors by 81%. CONCLUSION: Both SR-LRYGB and LSG reduced requirement for diabetic and cardiovascular medications, but increased requirement for nutritional supplementation, analgesia and psychiatric medications. There was a greater reduction in oral anti-diabetic medication prescriptions following SR-LRYGB compared to LSG, but no other difference in medication usage between surgical groups was found.


Assuntos
Diabetes Mellitus Tipo 2 , Gastrectomia , Derivação Gástrica , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/cirurgia , Derivação Gástrica/métodos , Feminino , Masculino , Gastrectomia/métodos , Método Duplo-Cego , Pessoa de Meia-Idade , Adulto , Obesidade Mórbida/cirurgia , Hipoglicemiantes/uso terapêutico , Redução de Peso , Laparoscopia/métodos , Resultado do Tratamento
3.
Oncotarget ; 15: 124-133, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38329728

RESUMO

GZ17-6.02, composed of curcumin, harmine and isovanillin, has undergone phase I evaluation in patients with solid tumors (NCT03775525) with an RP2D of 375 mg PO BID. The biology of GZ17-6.02 in malignant T cells and in particular those derived from mycosis fungoides (MF) patients, has not been studied. GZ17-6.02 alone and in combination with standard-of-care agents was effective in killing MF cells. All three components are necessary for optimal killing of MF cells. GZ17-6.02 activated ATM, the AMPK, NFκB and PERK and inactivated ERK1/2, AKT, ULK1, mTORC1, eIF2α, and reduced the expression of BCL-XL and MCL1. GZ17-6.02 increased ATG13 S318 phosphorylation and the expression of Beclin1, ATG5, BAK and BIM. GZ17-6.02 in a dose-dependent fashion enhanced autophagosome formation and autophagic flux, and tumor cell killing. Signaling by ATM and AMPK were both required for efficient killing but not for the dose-response effect whereas ER stress (eIF2α) and macroautophagy (Beclin1, ATG5) were required for both efficient killing and the dose-response. Knock down of the death receptor CD95 reduced killing by ~20% and interacted with autophagy inhibition to further reduce killing, collectively, by ~70%. Inhibition of autophagy and knock down of death-mediators downstream of the mitochondrion, AIF and caspase 3, almost abolished tumor cell killing. Hence in MF cells, GZ17-6.02 is a multi-factorial killer, utilizing ER stress, macroautophagy, death receptor signaling and directly causing mitochondrial dysfunction.


Assuntos
Antineoplásicos , Micose Fungoide , Neoplasias Cutâneas , Humanos , Bexaroteno/farmacologia , Proteínas Quinases Ativadas por AMP , Proteína Beclina-1/genética , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/genética , Receptores de Morte Celular
4.
Chem Sci ; 14(44): 12693-12706, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38020373

RESUMO

Plasmids are ubiquitous in biology, where they are used to study gene-function relationships and intricate molecular networks, and hold potential as therapeutic devices. Developing methods to control their function will advance their application in research and may also expedite their translation to clinical settings. Light is an attractive stimulus to conditionally regulate plasmid expression as it is non-invasive, and its properties such as wavelength, intensity, and duration can be adjusted to minimise cellular toxicity and increase penetration. Herein, we have developed a method to site-specifically introduce photocages into plasmids, by resynthesising one strand in a manner similar to Kunkel mutagenesis. Unlike alternative approaches to chemically modify plasmids, this method is sequence-independent at the site of modification and uses commercially available phosphoramidites. To generate our light-activated (LA) plasmids, photocleavable biotinylated nucleobases were introduced at specific sites across the T7 and CMV promoters on plasmids and bound to streptavidin to sterically block access. These LA-plasmids were then successfully used to control expression in both cell-free systems (T7 promoter) and mammalian cells (CMV promoter). These light-activated plasmids might be used to remotely control cellular activity and reduce off-target toxicity for future medical use. Our simple approach to plasmid modification might also be used to introduce novel chemical moieties for advanced function.

5.
J Orthop Case Rep ; 13(9): 108-111, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37753141

RESUMO

Introduction: Posterior cruciate ligament (PCL) injuries and tibial plateau fractures are common orthopedic injuries. In the pediatric population, femoral-sided avulsions are the most common injury pattern for PCL injuries. However, there is limited literature on the characterization and treatment of pediatric PCL avulsion with concomitant tibial plateau fracture. Case Report: We present the case of an adolescent female who was involved in an all-terrain vehicle rollover. The patient sustained a femoral-sided PCL avulsion injury with an associated lateral tibial plateau fracture. The PCL avulsion was treated through arthroscopic cruciate repair, while the tibial plateau fracture was managed with open reduction and internal fixation (ORIF). Conclusion: This case report highlights a rare combination of a femoral-sided PCL avulsion and lateral tibial plateau fracture in a pediatric patient. The treatment involved arthroscopic cruciate repair for the PCL avulsion and ORIF for the tibial plateau fracture. Further studies are needed to establish optimal management strategies for similar cases.

6.
Nat Chem Biol ; 19(9): 1138-1146, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37414974

RESUMO

Gene-expressing compartments assembled from simple, modular parts, are a versatile platform for creating minimal synthetic cells with life-like functions. By incorporating gene regulatory motifs into their encapsulated DNA templates, in situ gene expression and, thereby, synthetic cell function can be controlled according to specific stimuli. In this work, cell-free protein synthesis within synthetic cells was controlled using light by encoding genes of interest on light-activated DNA templates. Light-activated DNA contained a photocleavable blockade within the T7 promoter region that tightly repressed transcription until the blocking groups were removed with ultraviolet light. In this way, synthetic cells were activated remotely, in a spatiotemporally controlled manner. By applying this strategy to the expression of an acyl homoserine lactone synthase, BjaI, quorum-sensing-based communication between synthetic cells and bacteria was controlled with light. This work provides a framework for the remote-controlled production and delivery of small molecules from nonliving matter to living matter, with applications in biology and medicine.


Assuntos
Células Artificiais , Proteínas de Bactérias/metabolismo , Comunicação Celular , Bactérias/genética , Bactérias/metabolismo , Percepção de Quorum/genética
7.
Obes Surg ; 33(7): 1989-1996, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37243915

RESUMO

INTRODUCTION: Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) are common bariatric procedures that are effective in treating type 2 diabetes (T2D) in patients with obesity. Limited data from randomized trials are available comparing longevity of diabetes remission directly between the two procedures beyond 5 years. METHODS: A prospective, randomized, parallel, two-arm, clinical trial comparing the outcomes of silastic ring (SR)-LRYGB versus LSG was conducted at a single (Auckland, New Zealand) center. Patients and researchers were blinded until the 5-year mark and follow-up after this was unblinded. Eligible patients had T2D of > 6 months duration with a BMI 35--65 kg/m2 and were aged 20-55 years. Randomization was 1:1 to SR-LRYGB and LSG following induction of anesthesia and was stratified by age group, BMI group, ethnicity, diabetes duration, and insulin therapy. The primary outcome was T2D remission, defined as HbA1c < 6% (42 mmol/mol), without the use of glucose-lowering medications. RESULTS: A total of 114 patients were randomized of whom 6 died before the 7-year follow-up (2 SR-LRYGB, 4 LSG). Diabetes remission, assessed in 89 (82.4%) of the remaining patients, was seen in 23/50 (46.0%) after SR-LRYGB and 12/39 (30.8%) after LSG (adjusted OR 4.64, 95% CI 1.39, 15.52, p = 0.013). Percentage total body weight loss was greater after SR-LRYGB than LSG (26.2% vs 13.4%; absolute difference 12.8%; 95% CI 7.2%, 18.2%; p < 0.001). Complication rates were similar between groups. CONCLUSION: SR-LRYGB was superior to LSG for diabetes remission and weight loss at 7 years following surgery, with acceptable complication rates.


Assuntos
Diabetes Mellitus Tipo 2 , Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Humanos , Derivação Gástrica/métodos , Obesidade Mórbida/cirurgia , Diabetes Mellitus Tipo 2/cirurgia , Estudos Prospectivos , Resultado do Tratamento , Laparoscopia/métodos , Gastrectomia/métodos , Redução de Peso
8.
J Am Chem Soc ; 145(17): 9471-9480, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37125650

RESUMO

Cell-free gene expression is a vital research tool to study biological systems in defined minimal environments and has promising applications in biotechnology. Developing methods to control DNA templates for cell-free expression will be important for precise regulation of complex biological pathways and use with synthetic cells, particularly using remote, nondamaging stimuli such as visible light. Here, we have synthesized blue light-activatable DNA parts that tightly regulate cell-free RNA and protein synthesis. We found that this blue light-activated DNA could initiate expression orthogonally to our previously generated ultraviolet (UV) light-activated DNA, which we used to generate a dual-wavelength light-controlled cell-free AND-gate. By encapsulating these orthogonal light-activated DNAs into synthetic cells, we used two overlapping patterns of blue and UV light to provide precise spatiotemporal control over the logic gate. Our blue and UV orthogonal light-activated DNAs will open the door for precise control of cell-free systems in biology and medicine.


Assuntos
Células Artificiais , Luz , DNA/genética , Raios Ultravioleta , Biotecnologia
9.
Commun Chem ; 6(1): 59, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37005479

RESUMO

Controlling cell-free expression of a gene to protein with non-invasive stimuli is vital to the future application of DNA nanodevices and synthetic cells. However, little emphasis has been placed on developing light-controlled 'off' switches for cell-free expression. Light-activated antisense oligonucleotides have been developed to induce gene knockdown in living cells; however, they are complicated to synthesise and have not been tested in cell-free systems. Developing simple, accessible methods to produce light-activated antisense oligonucleotides will be crucial for allowing their application in cell-free biology and biotechnology. Here, we report a mild, one-step method for selectively attaching commercially-available photoremovable protecting groups, photocages, onto phosphorothioate linkages of antisense oligonucleotides. Using this photocaging method, upon illumination, the original phosphorothioate antisense oligonucleotide is reformed. Photocaged antisense oligonucleotides, containing mixed phosphorothioate and phosphate backbones, showed a drastic reduction in duplex formation and RNase H activity, which was recovered upon illumination. We then demonstrated that these photocaged antisense oligonucleotides can be used to knock down cell-free protein synthesis using light. This simple and accessible technology will have future applications in light-controlled biological logic gates and regulating the activity of synthetic cells.

10.
Chem Commun (Camb) ; 59(38): 5685-5688, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37073467

RESUMO

Developing simple methods to silence antisense oligonucleotides (ASOs) using photocages opens up the possibility of precise regulation of biological systems. Here, we have developed a photocaging strategy based on 'handcuffing' two ASOs to a protein. Silencing was achieved by divalent binding of two terminally photocleavable biotin-modified ASOs to a single streptavidin. These 'handcuffed' oligonucleotides showed a drastic reduction in gene knockdown activity in cell-free protein synthesis and were unlocked through illumination, regaining full activity.


Assuntos
Oligonucleotídeos Antissenso , Oligonucleotídeos , Humanos , Células Epiteliais/metabolismo , Técnicas de Silenciamento de Genes , Oligonucleotídeos/metabolismo , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/metabolismo
11.
J Am Chem Soc ; 145(17): 9481-9487, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37074404

RESUMO

Cell-free expression of a gene to protein has become a vital tool in nanotechnology and synthetic biology. Remote-control of cell-free systems with multiple, orthogonal wavelengths of light would enable precise, noninvasive modulation, opening many new applications in biology and medicine. While there has been success in developing ON switches, the development of OFF switches has been lacking. Here, we have developed orthogonally light-controlled cell-free expression OFF switches by attaching nitrobenzyl and coumarin photocages to antisense oligonucleotides. These light-controlled OFF switches can be made from commercially available oligonucleotides and show a tight control of cell-free expression. Using this technology, we have demonstrated orthogonal degradation of two different mRNAs, depending on the wavelength used. By combining with our previously generated blue-light-activated DNA template ON switch, we were able to start transcription with one wavelength of light and then halt the translation of the corresponding mRNA to protein with a different wavelength, at multiple timepoints. This precise, orthogonal ON and OFF remote-control of cell-free expression will be an important tool for the future of cell-free biology, especially for use with biological logic gates and synthetic cells.


Assuntos
Oligonucleotídeos , Proteínas , Sistema Livre de Células , RNA Mensageiro/genética
12.
Obes Surg ; 33(5): 1536-1544, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36964319

RESUMO

PURPOSE: This study investigated the impact of either Roux-en-Y gastric bypass with silastic ring (SR-RYGB) or sleeve gastrectomy (SG) types of bariatric surgery on psychological health and explored the role of pre-existing depressive symptoms on weight loss. MATERIALS AND METHODS: A total of 114 participants with obesity and type 2 diabetes were randomized to receive SR-RYGB or SG at a single centre. Data from the Hospital Anxiety and Depression Scale (HADS), RAND 36-item Health Survey and body weight were collected before surgery and annually for 5 years. RESULTS: Sixteen patients were lost to follow-up at 5 years. Of the 98 patients who completed 5-year psychological follow-up assessments, 13 had mild to severe depressive symptoms (SR-RYGB n = 6, SG n = 7). SR-RYGB and SG resulted in similar psychological health improvement but percent weight loss at 5 years was greater for SR-RYGB by 10.6% (95% CI: 7.2 to 14.0, P < 0.0001). Scores for depressive symptoms and most RAND-36 domains improved significantly from baseline to 5 years in both groups. Patients with pre-existing depressive symptoms had similar percent weight loss at 5 years compared to patients without depressive symptoms, irrespective of procedural type. CONCLUSION: Patients receiving either SR-RYGB or SG had comparable psychosocial functioning, which was maintained to 5 years post-surgery. Pre-existing depressive symptoms did not affect weight loss achieved at 5 years. These findings confirm previous longitudinal studies demonstrating that bariatric surgery is generally associated with improved psychosocial functioning.


Assuntos
Cirurgia Bariátrica , Diabetes Mellitus Tipo 2 , Derivação Gástrica , Obesidade Mórbida , Humanos , Obesidade Mórbida/cirurgia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/cirurgia , Cirurgia Bariátrica/métodos , Derivação Gástrica/métodos , Obesidade/complicações , Obesidade/cirurgia , Redução de Peso , Gastrectomia/métodos , Estudos Retrospectivos , Resultado do Tratamento
13.
Life (Basel) ; 13(1)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36676156

RESUMO

Within many chemical and biological systems, both synthetic and natural, communication via chemical messengers is widely viewed as a key feature. Often known as molecular communication, such communication has been a concern in the fields of synthetic biologists, nanotechnologists, communications engineers, and philosophers of science. However, interactions between these fields are currently limited. Nevertheless, the fact that the same basic phenomenon is studied by all of these fields raises the question of whether there are unexploited interdisciplinary synergies. In this paper, we summarize the perspectives of each field on molecular communications, highlight potential synergies, discuss ongoing challenges to exploit these synergies, and present future perspectives for interdisciplinary efforts in this area.

14.
J Am Chem Soc ; 144(38): 17468-17476, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-36103297

RESUMO

Biological cells display complex internal architectures with distinct micro environments that establish the chemical heterogeneity needed to sustain cellular functions. The continued efforts to create advanced cell mimics, namely, artificial cells, demands strategies for constructing similarly heterogeneous structures with localized functionalities. Here, we introduce a platform for constructing membraneless artificial cells from the self-assembly of synthetic DNA nanostructures in which internal domains can be established thanks to prescribed reaction-diffusion waves. The method, rationalized through numerical modeling, enables the formation of up to five distinct concentric environments in which functional moieties can be localized. As a proof-of-concept, we apply this platform to build DNA-based artificial cells in which a prototypical nucleus synthesizes fluorescent RNA aptamers that then accumulate in a surrounding storage shell, thus demonstrating the spatial segregation of functionalities reminiscent of that observed in biological cells.


Assuntos
Aptâmeros de Nucleotídeos , Células Artificiais , Nanoestruturas , DNA/química , Difusão , Nanoestruturas/química
16.
Diabetes Care ; 45(7): 1503-1511, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35554515

RESUMO

OBJECTIVE: To determine whether silastic ring laparoscopic Roux-en-Y gastric bypass (SR-LRYGB) or laparoscopic sleeve gastrectomy (LSG) produces superior diabetes remission at 5 years. RESEARCH DESIGN AND METHODS: In a single-center, double-blind trial, 114 adults with type 2 diabetes and BMI 35-65 kg/m2 were randomly assigned to SR-LRYGB or LSG (1:1; stratified by age-group, BMI group, ethnicity, diabetes duration, and insulin therapy) using a web-based service. Diabetes and other metabolic medications were adjusted according to a prespecified protocol. The primary outcome was diabetes remission assessed at 5 years, defined by HbA1c <6% (42 mmol/mol) without glucose-lowering medications. Secondary outcomes included changes in weight, cardiometabolic risk factors, quality of life, and adverse events. RESULTS: Diabetes remission after SR-LRYGB versus LSG occurred in 25 (47%) of 53 vs. 18 (33%) of 55 patients (adjusted odds ratios 4.5 [95% CI 1.6, 15.5; P = 0.009] and 4.2 [1.3, 13.4; P = 0.015] in the intention-to-treat analysis). Percent body weight loss was greater after SR-LRYGB than after LSG (absolute difference 10.7%; 95% CI 7.3, 14.0; P < 0.001). Improvements in cardiometabolic risk factors were similar, but HDL cholesterol increased more after SR-LRYGB. Early and late complications were similar in both groups. General health and physical functioning improved after both types of surgery, with greater improvement in physical functioning after SR-LRYGB. People of Maori or Pacific ethnicity (26%) had lower incidence of diabetes remission than those of New Zealand European or other ethnicities (2 of 25 vs. 41 of 83; P < 0.001). CONCLUSIONS: SR-LRYGB provided superior diabetes remission and weight loss compared with LSG at 5 years, with similar low risks of complications.


Assuntos
Diabetes Mellitus Tipo 2 , Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Adulto , Diabetes Mellitus Tipo 2/etiologia , Diabetes Mellitus Tipo 2/cirurgia , Método Duplo-Cego , Gastrectomia , Derivação Gástrica/métodos , Humanos , Laparoscopia/métodos , Obesidade/cirurgia , Obesidade Mórbida/cirurgia , Complicações Pós-Operatórias/epidemiologia , Qualidade de Vida , Resultado do Tratamento
17.
Cureus ; 14(2): e21886, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35265418

RESUMO

Osteopetrosis is a genetic illness defined by defective osteoclasts that are incapable of absorbing adequate amounts of bone. This exceedingly rare disorder has been linked to multiple genetic mutations that have a direct impact on osteoclast function. Osteopetrosis causes bones to become brittle with large amounts of cortical bone formation making patients susceptible to pathologic fractures, pancytopenia, and cranial neuropathies among other sequelae. Known as the "marble bone disease," this condition can range from as severe as causing death in newborn infants to as mild as an incidental finding of increased cortical thickening in a trauma patient. This case demonstrates an incidental finding of osteopetrosis in a trauma patient who suffered from significant injuries as a result of a high-velocity trauma. The patient was the pedestrian in a car vs pedestrian accident and suffered from a central cord syndrome in his cervical spine, a right humerus fracture, a left subtrochanteric femur fracture, a right tibia fracture, and a right fibula fracture. This case report illustrates the complexity of dealing with a polytrauma patient with osteopetrosis and reviews the literature on the approach to fracture fixation in osteopetrotic individuals. This paper will also discuss current medication recommendations and the current standard of care for optimizing patients with osteopetrosis as well as genetic counseling.

18.
Cureus ; 14(2): e21829, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35291548

RESUMO

A 25-year-old male developed left knee pain several years after anterior cruciate ligament (ACL) reconstruction. MRI showed a suspected cyclops lesion over the anterior portion of the knee. The patient underwent diagnostic knee arthroscopy with lesion removal, and it was discovered the patient had a tenosynovial giant cell tumor. A tenosynovial giant cell tumor is a rare intraarticular lesion that requires a high suspicion for clinical diagnosis. Management is currently centered around arthroscopic versus open removal of the lesion with serial monitoring and advanced imaging for recurrence.

19.
Front Microbiol ; 13: 796018, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35265057

RESUMO

Methane emissions from aquatic ecosystems are increasingly recognized as substantial, yet variable, contributions to global greenhouse gas emissions. This is in part due to the challenge of modeling biologic parameters that affect methane emissions from a wide range of sediments. For example, the impacts of fish bioturbation on methane emissions in the literature have been shown to result in a gradient of reduced to enhanced emissions from sediments. However, it is likely that variation in experimental fish density, and consequently the frequency of bioturbation by fish, impacts this outcome. To explore how the frequency of disturbance impacts the levels of methane emissions in our previous work we quantified greenhouse gas emissions in sediment microcosms treated with various frequencies of mechanical disturbance, analogous to different levels of activity in benthic feeding fish. Greenhouse gas emissions were largely driven by methane ebullition and were highest for the intermediate disturbance frequency (disturbance every 7 days). The lowest emissions were for the highest frequency treatment (3 days). This work investigated the corresponding impacts of disturbance treatments on the microbial communities associated with producing methane. In terms of total microbial community structure, no statistical difference was observed in the total community structure of any disturbance treatment (0, 3, 7, and 14 days) or sediment depth (1 and 3 cm) measured. Looking specifically at methanogenic Archaea however, a shift toward greater relative abundance of a putatively oxygen-tolerant methanogenic phylotype (ca. Methanothrix paradoxum) was observed for the highest frequency treatments and at depths impacted by disturbance (1 cm). Notably, quantitative analysis of ca. Methanothrix paradoxum demonstrated no change in abundance, suggesting disturbance negatively and preferentially impacted other methanogen populations, likely through oxygen exposure. This was further supported by a linear decrease in quantitative abundance of methanogens (assessed by qPCR of the mcrA gene), with increased disturbance frequency in bioturbated sediments (1 cm) as opposed to those below the zone of bioturbation (3 cm). However, total methane emissions were not simply a function of methanogen populations and were likely impacted by the residence time of methane in the lower frequency disturbance treatments. Low frequency mechanical disruption results in lower methane ebullition compared to higher frequency treatments, which in turn resulted in reduced overall methane release, likely through enhanced methanotrophic activities, though this could not be identified in this work. Overall, this work contributes to understanding how animal behavior may impact variation in greenhouse gas emissions and provides insight into how frequency of disturbance may impact emissions.

20.
Front Pharmacol ; 13: 814134, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35153785

RESUMO

The aim of the study was to apply Physiologically-Based Pharmacokinetic (PBPK) modelling to predict the effect of liver disease (LD) on the pharmacokinetics (PK) of dexamethasone (DEX) in the treatment of COVID-19. A whole-body PBPK model was created to simulate 100 adult individuals aged 18-60 years. Physiological changes (e.g., plasma protein concentration, liver size, CP450 expression, hepatic blood flow) and portal vein shunt were incorporated into the LD model. The changes were implemented by using the Child-Pugh (CP) classification system. DEX was qualified using clinical data in healthy adults for both oral (PO) and intravenous (IV) administrations and similarly propranolol (PRO) and midazolam (MDZ) were qualified with PO and IV clinical data in healthy and LD adults. The qualified model was subsequently used to simulate a 6 mg PO and 20 mg IV dose of DEX in patients with varying degrees of LD, with and without shunting. The PBPK model was successfully qualified across DEX, MDZ and PRO. In contrast to healthy adults, the simulated systemic clearance of DEX decreased (35%-60%) and the plasma concentrations increased (170%-400%) in patients with LD. Moreover, at higher doses of DEX, the AUC ratio between healthy/LD individuals remained comparable to lower doses. The exposure of DEX in different stages of LD was predicted through PBPK modelling, providing a rational framework to predict PK in complex clinical scenarios related to COVID-19. Model simulations suggest dose adjustments of DEX in LD patients are not necessary considering the low dose administered in the COVID-19 protocol.

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