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1.
Plant Physiol ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709683

RESUMO

Plants respond to increased CO2 concentrations through stomatal closure, which can contribute to increased water use efficiency. Grasses display faster stomatal responses than eudicots due to dumbbell-shaped guard cells flanked by subsidiary cells working in opposition. However, forward genetic screening for stomatal CO2 signal transduction mutants in grasses has yet to be reported. The grass model Brachypodium distachyon is closely related to agronomically important cereal crops, sharing largely collinear genomes. To gain insights into CO2 control mechanisms of stomatal movements in grasses, we developed an unbiased forward genetic screen with an EMS-mutagenized Brachypodium distachyon M5 generation population using infrared imaging to identify plants with altered leaf temperatures at elevated CO2. Among isolated mutants, a "chill1" mutant exhibited cooler leaf temperatures than wildtype Bd21-3 parent control plants after exposure to increased [CO2]. chill1 plants showed strongly impaired high CO2-induced stomatal closure despite retaining a robust abscisic acid-induced stomatal closing response. Through bulked segregant whole-genome-sequencing analyses followed by analyses of further backcrossed F4 generation plants and generation and characterization of sodium-azide and CRISPR-cas9 mutants, chill1 was mapped to a protein kinase, Mitogen-Activated Protein Kinase 5 (BdMPK5). The chill1 mutation impaired BdMPK5 protein-mediated CO2/HCO3- sensing together with the High Temperature 1 (HT1) Raf-like kinase in vitro. Furthermore, AlphaFold2-directed structural modeling predicted that the identified BdMPK5-D90N chill1 mutant residue is located at the interface of BdMPK5 with the BdHT1 Raf-like kinase. BdMPK5 is a key signaling component that mediates CO2-induced stomatal movements and is proposed to function as a component of the primary CO2 sensor in grasses.

2.
PLoS Biol ; 20(4): e3001600, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35421093

RESUMO

The risk of accidental or deliberate misuse of biological research is increasing as biotechnology advances. As open science becomes widespread, we must consider its impact on those risks and develop solutions that ensure security while facilitating scientific progress. Here, we examine the interaction between open science practices and biosecurity and biosafety to identify risks and opportunities for risk mitigation. Increasing the availability of computational tools, datasets, and protocols could increase risks from research with misuse potential. For instance, in the context of viral engineering, open code, data, and materials may increase the risk of release of enhanced pathogens. For this dangerous subset of research, both open science and biosecurity goals may be achieved by using access-controlled repositories or application programming interfaces. While preprints accelerate dissemination of findings, their increased use could challenge strategies for risk mitigation at the publication stage. This highlights the importance of oversight earlier in the research lifecycle. Preregistration of research, a practice promoted by the open science community, provides an opportunity for achieving biosecurity risk assessment at the conception of research. Open science and biosecurity experts have an important role to play in enabling responsible research with maximal societal benefit.


Assuntos
Biosseguridade , Contenção de Riscos Biológicos , Contenção de Riscos Biológicos/métodos
3.
Lancet Oncol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38942046

RESUMO

BACKGROUND: The standard of care for patients with intermediate-to-high risk renal cell carcinoma is partial or radical nephrectomy followed by surveillance. We aimed to investigate use of nivolumab before nephrectomy followed by adjuvant nivolumab in patients with high-risk renal cell carcinoma to determine recurrence-free survival compared with surgery only. METHODS: In this open-label, randomised, phase 3 trial (PROSPER EA8143), patients were recruited from 183 community and academic sites across the USA and Canada. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-1, with previously untreated clinical stage T2 or greater or Tany N+ renal cell carcinoma of clear cell or non-clear cell histology planned for partial or radical nephrectomy. Selected patients with oligometastatic disease, who were disease free at other disease sites within 12 weeks of surgery, were eligible for inclusion. We randomly assigned (1:1) patients using permuted blocks (block size of 4) within stratum (clinical TNM stage) to either nivolumab plus surgery, or surgery only followed by surveillance. In the nivolumab group, nivolumab 480 mg was administered before surgery, followed by nine adjuvant doses. The primary endpoint was investigator-reviewed recurrence-free survival in patients with renal cell carcinoma assessed in all randomly assigned patients regardless of histology. Safety was assessed in all randomly assigned patients who started the assigned protocol treatment. This trial is registered with ClinicalTrials.gov, NCT03055013, and is closed to accrual. FINDINGS: Between Feb 2, 2017, and June 2, 2021, 819 patients were randomly assigned to nivolumab plus surgery (404 [49%]) or surgery only (415 [51%]). 366 (91%) of 404 patients assigned to nivolumab plus surgery and 387 (93%) of 415 patients assigned to surgery only group started treatment. Median age was 61 years (IQR 53-69), 248 (30%) of 819 patients were female, 571 (70%) were male, 672 (88%) were White, and 77 (10%) were Hispanic or Latino. The Data and Safety Monitoring Committee stopped the trial at a planned interim analysis (March 25, 2022) because of futility. Median follow-up was 30·4 months (IQR 21·5-42·4) in the nivolumab group and 30·1 months (21·9-41·8) in the surgery only group. 381 (94%) of 404 patients in the nivolumab plus surgery group and 399 (96%) of 415 in the surgery only group had renal cell carcinoma and were included in the recurrence-free survival analysis. As of data cutoff (May 24, 2023), recurrence-free survival was not significantly different between nivolumab (125 [33%] of 381 had recurrence-free survival events) versus surgery only (133 [33%] of 399; hazard ratio 0·94 [95% CI 0·74-1·21]; one-sided p=0·32). The most common treatment-related grade 3-4 adverse events were elevated lipase (17 [5%] of 366 patients in the nivolumab plus surgery group vs none in the surgery only group), anaemia (seven [2%] vs nine [2%]), increased alanine aminotransferase (ten [3%] vs one [<1%]), abdominal pain (four [1%] vs six [2%]), and increased serum amylase (nine [2%] vs none). 177 (48%) patients in the nivolumab plus surgery group and 93 (24%) in the surgery only group had grade 3-5 adverse events due to any cause, the most common of which were anaemia (23 [6%] vs 19 [5%]), hypertension (27 [7%] vs nine [2%]), and elevated lipase (18 [5%] vs six [2%]). 48 (12%) of 404 patients in the nivolumab group and 40 (10%) of 415 in the surgery only group died, of which eight (2%) and three (1%), respectively, were determined to be treatment-related. INTERPRETATION: Perioperative nivolumab before nephrectomy followed by adjuvant nivolumab did not improve recurrence-free survival versus surgery only followed by surveillance in patients with high-risk renal cell carcinoma. FUNDING: US National Institutes of Health National Cancer Institute and Bristol Myers Squibb.

4.
J Urol ; 212(1): 3-10, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38661067

RESUMO

PURPOSE: Although representing approximately 25% of patients diagnosed with bladder cancer, muscle-invasive bladder cancer (MIBC) carries a significant risk of death that has not significantly changed in decades. Increasingly, clinicians and patients recognize the importance of multidisciplinary collaborative efforts that take into account survival and quality of life concerns. This guideline provides a risk-stratified, clinical framework for the management of muscle-invasive urothelial bladder cancer. METHODOLOGY/METHODS: In 2024, the MIBC guideline was updated through the AUA amendment process in which newly published literature is reviewed and integrated into previously published guidelines in an effort to maintain currency. The amendment allowed for the incorporation of additional literature released since the previous 2020 amendment. The updated search gathered literature from May 2020 to November 2023. This review identified 3739 abstracts, of which 46 met inclusion criteria.When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. RESULTS: Updates were made regarding neoadjuvant/adjuvant chemotherapy, radical cystectomy, pelvic lymphadenectomy, multi-modal bladder preserving therapy, and future directions. Further revisions were made to the methodology and reference sections as appropriate. CONCLUSIONS: This guideline seeks to improve clinicians' ability to evaluate and treat patients with MIBC based on currently available evidence. Future studies will be essential to further support or refine these statements to improve patient care.


Assuntos
Invasividade Neoplásica , Neoplasias da Bexiga Urinária , Neoplasias da Bexiga Urinária/terapia , Neoplasias da Bexiga Urinária/patologia , Humanos , Cistectomia/métodos , Carcinoma de Células de Transição/terapia , Carcinoma de Células de Transição/patologia , Urologia/normas
5.
J Urol ; 211(4): 533-538, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38265030

RESUMO

PURPOSE: The purpose of this American Urological Association (AUA)/Society of Urologic Oncology (SUO) guideline amendment is to provide a useful reference on the effective evidence-based treatment strategies for non-muscle invasive bladder cancer (NMIBC). MATERIALS AND METHODS: In 2023, the NMIBC guideline was updated through the AUA amendment process in which newly published literature is reviewed and integrated into previously published guidelines in an effort to maintain currency. The amendment allowed for the incorporation of additional literature released since the previous 2020 amendment. The updated search gathered literature from July 2019 to May 2023. This review identified 1918 abstracts, of which 75 met inclusion criteria.When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) in support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, additional information is provided as Clinical Principles and Expert Opinions. RESULTS: Updates were made to statements on variant histologies, urine markers after diagnosis of bladder cancer, intravesical therapy, BCG maintenance, enhanced cystoscopy, and future directions. Further revisions were made to the methodology and reference sections as appropriate. CONCLUSIONS: This guideline seeks to improve clinicians' ability to evaluate and treat patients with NMIBC based on currently available evidence. Future studies will be essential to further support or refine these statements to improve patient care.


Assuntos
Neoplasias não Músculo Invasivas da Bexiga , Neoplasias da Bexiga Urinária , Urologia , Humanos , Neoplasias da Bexiga Urinária/diagnóstico , Neoplasias da Bexiga Urinária/terapia , Cistoscopia , Resultado do Tratamento
6.
Osteoporos Int ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38653862

RESUMO

Review of medical records from 173 women with osteoporosis who received abaloparatide treatment revealed that 96.0% had at least one visit for osteoporosis management and 55.5% had medication support group access. The most common reasons for discontinuing treatment were financial (31.2%) and tolerability (22.8%). Most patients (64.8%) completed treatment as prescribed. PURPOSE: Abaloparatide is approved for the treatment of women with postmenopausal osteoporosis at high risk for fracture. This study evaluated real-world treatment patterns for patients new to abaloparatide, regardless of osteoporosis treatment history. METHODS: Data for patients with ≥ 1 prescription for abaloparatide were collected retrospectively from six academic and clinical practice settings across the US. RESULTS: A total of 173 patients were enrolled (mean [SD] age, 69.8 [7.4] years). At the time of abaloparatide treatment initiation, 78.6% had received other osteoporosis medications. Mean (SD) time from discontinuation of osteoporosis medications prior to initiation of abaloparatide was 1.7 (3.2) years. Twenty-four months of follow-up data from the initiation date of abaloparatide was collected from 94.0% of patients and 6.0% of patients had 12-24 months of follow-up. During the follow-up period, 96.0% of patients had at least one visit for osteoporosis management and 55.5% had access to a medication support program. The median duration of therapy was 18.6 months and 105/162 (64.8%) completed abaloparatide treatment as prescribed. The most common reasons for treatment discontinuation were financial (31.2%) and tolerability (22.8%). Following completion of a course of treatment with abaloparatide, 82/162 (50.6%) patients transitioned to another osteoporosis medication. The median time between abaloparatide treatment course completion and the initiation of follow-on medication was 21 days. CONCLUSION: Most patients completed treatment with abaloparatide as prescribed, and over half continued with an antiresorptive agent. This favorable conduct may be the result of regular follow-up visits and accessibility to both medication and patient support services.

7.
Wound Repair Regen ; 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38958095

RESUMO

Keloid disorder is a morbid and disfiguring benign fibroproliferative disease with a higher incidence in groups with darker skin pigmentation. Predicting keloidogenesis in patients is difficult with treatment primarily aimed at preventing further scar expansion and improving aesthetics without addressing their unknown underlying pathophysiology. We aimed to identify potential genetic predispositions to keloid scarring in the literature. A search was conducted on 21 August 2023, by the first and second authors independently from 1985 to August 2023 using PubMed, MEDLINE, Embase, Web of Science, Scopus and CINAHL. The following MeSH terms were used: 'Keloid', 'Risk' and 'Genetic'. Two researchers independently searched for studies based on titles and abstracts and screened filtered articles by reviewing full text. If no agreement could be reached, a third senior author designated whether the article should be included. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 statement as the basis of our organisation. Human studies with genetic analysis to determine an association of a protein or gene to keloidogenesis were selected for inclusion. Studies in languages other than English, reviews, conference articles, and book chapters were excluded. Fifty studies met inclusion criteria. The human leukocyte antigen (HLA) system was broadly implicated, and the DRB1*15 allele was associated with an increased risk of keloid in three separate ethnic groups. Some HLA Class I alleles were associated with keloid in one population but not in others. Additionally, polymorphisms in the E3 ubiquitin-protein ligase (NEDD4) signal cascade and vitamin D receptor (VDR) have been implicated in diverse groups. No current genetic test can predict keloid risk. Our review identified candidate predisposing genes, including NEDD4, VDR and components of the HLA system. Further studies in heterogeneous populations are needed to identify reliable screening targets.

8.
Proc Natl Acad Sci U S A ; 118(22)2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34039712

RESUMO

Although ultrafast manipulation of magnetism holds great promise for new physical phenomena and applications, targeting specific states is held back by our limited understanding of how magnetic correlations evolve on ultrafast timescales. Using ultrafast resonant inelastic X-ray scattering we demonstrate that femtosecond laser pulses can excite transient magnons at large wavevectors in gapped antiferromagnets and that they persist for several picoseconds, which is opposite to what is observed in nearly gapless magnets. Our work suggests that materials with isotropic magnetic interactions are preferred to achieve rapid manipulation of magnetism.

9.
Ann Plast Surg ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38896863

RESUMO

PURPOSE: Dermatochalasis with lateral hooding and medial orbital fat loss are common signs of aging in the upper eyelid. Removing the excess skin in this area through infrabrow skin excision can effectively lift the loose skin of the upper eyelid and minimizes visible scarring. Additionally, we have identified three compartments of orbital fat prolapse based on orbital anatomy. Transferring volume from the lateral compartment to the intermediate region can flatten the lateral upper eyelid and create medial fullness, which ultimately rejuvenates the upper eyelid. This study presents an operative method for correcting age-related changes in the upper eyelid using this technique. METHODS: A total of 34 eyelids from 17 patients underwent a surgical procedure involving infrabrow skin excision, along with repositioning and lifting of lateral orbital fat. The inclusion criteria consisted of patients with moderate to severe upper eyelid dermatochalasis, coupled with middle fat loss and lateral hooding. To correct lateral hooding and restore midfacial fullness, lateral orbital fat was repositioned to an intermediate position, and the orbicularis oculi muscle was fold-sutured to the corrugator supercilii muscle. RESULTS: The mean age of the patients was 55.59 ± 3.20 years, with a range of 48 to 61 years. The mean follow-up period was 9.94 ± 1.35 months, ranging from 8 to 12 months. Patients were evaluated at 1-month, 3-month, and 6-month intervals. The Strasser system was used to evaluate the surgical outcomes at 3 months. All patients achieved good surgical outcomes, expressed through satisfactory cosmetic improvements, and improved visual field. The procedure effectively corrected lateral hooding and loss of middle orbital fat through infrabrow skin excision. No complications, such as wound dehiscence, lagophthalmos, noticeable scarring, ocular dyskinesia, or sensory changes, were observed. CONCLUSIONS: The combination of infrabrow skin excision, repositioning of lateral orbital fat, and lifting of the orbicularis oculi muscle effectively addresses moderate to severe dermatochalasis, lateral hooding, medial fat loss, and improves elasticity of the anterior wall of the upper lid in our patients. This procedure can produce satisfactory and long-lasting aesthetic results with an inconspicuous scar beneath the brow.

10.
Surgeon ; 22(1): e26-e33, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37567846

RESUMO

BACKGROUND AND PURPOSE: Non-alcoholic fatty liver disease (NAFLD) has increasing worldwide prevalence, fuelled by rising obesity rates, and weight reduction is the mainstay of its management. We sought to study the effect of bariatric surgery, the most effective long-term treatment for obesity and associated metabolic disorders, on liver function in people with obesity. METHODS: We performed a retrospective longitudinal cohort study of 511 patients who had undergone bariatric surgery (71 sleeve gastrectomy and 440 gastric bypass) over 60 months of follow-up. Patients were stratified into groups based on their baseline alanine aminotransferase (ALT) into Group A (ALT < 40 U/L) and Group B (ALT > 40 U/L). Postoperative follow-up weight loss, liver function tests, HbA1c, blood pressure and lipid profiles were collected. FINDINGS: Bariatric surgery resulted in nadir total weight loss of 33.1% by 24 months (p < 0.001) with no significant difference between groups. In people with raised baseline ALT (Group B), ALT and gamma glutamyl transferase (GGT) levels decreased significantly by 4 months postoperatively (p < 0.001) and sustained over 60 months of follow-up. There was also significant and sustained reduction in HbA1c, blood pressure, total cholesterol, and non-HDL cholesterol overall with no differences between groups. CONCLUSIONS: Bariatric surgery results in significant weight loss, improves liver function tests and metabolic outcomes in people with obesity. Bariatric surgery could be a therapeutic consideration for patients with NAFLD associated with severe obesity who have otherwise been unresponsive to conservative management.


Assuntos
Cirurgia Bariátrica , Hepatopatia Gordurosa não Alcoólica , Obesidade Mórbida , Humanos , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/cirurgia , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Estudos Retrospectivos , Hemoglobinas Glicadas , Estudos Longitudinais , Cirurgia Bariátrica/métodos , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Alanina Transaminase , Gastrectomia/métodos , Redução de Peso/fisiologia , Colesterol , Resultado do Tratamento
11.
J Craniofac Surg ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856196

RESUMO

INTRODUCTION: The thyroid cartilage, an androgen-sensitive structure, enlarges during puberty in individuals assigned male at birth, often resulting in a pronounced neck protuberance. This feature can exacerbate gender dysphoria in transfeminine patients. Chondrolaryngoplasty, commonly known as tracheal shave, is a procedure incorporated into facial feminization surgery (FFS) to address this issue. This study reports on the implementation of an endoscopic-assisted chondrolaryngoplasty technique, its safety, and the outcomes observed. METHODS: The authors conducted a retrospective review of chondrolaryngoplasty cases at our center, examining patient outcomes and procedural safety. The analysis included a breakdown of concurrent gender-affirming surgeries performed. An endoscopic-guided technique was utilized, and its procedural steps were documented in a video. RESULTS: In the past five years, 32 patients received chondrolaryngoplasty at our facility. Postoperative complications were minimal, with no infections, wound separations, or surgical site complications reported. Only one patient experienced temporary hoarseness, which resolved within 6 weeks without intervention. The procedure was frequently combined with other surgical interventions, with the average patient undergoing 3 additional procedures, the most common being augmentation mammaplasty, brow lifting, and frontal bone reduction. CONCLUSIONS: Tracheal shave is an effective surgical technique for alleviating gender dysphoria in transfeminine patients. Keys to its success include the accurate identification of thyroid cartilage, especially in patients with enlarged cricoid cartilages, intraoperative coordination with anesthesia for laryngoscopic vocal cord visualization, sub-perichondrial cartilage excision to minimize the risk of bleeding and damage near the vocal cords, and carefully layered closure to optimize scar healing.

12.
J Craniofac Surg ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709082

RESUMO

BACKGROUND: Even after palatoplasty, the incidence of velopharyngeal dysfunction (VPD) can reach 30%; however, these estimates arise from high-income countries (HICs) where speech-language pathologists (SLP) are part of standardized cleft teams. The VPD burden in low- and middle-income countries (LMICs) is unknown. This study aims to develop a machine-learning model that can detect the presence of VPD using audio samples alone. METHODS: Case and control audio samples were obtained from institutional and publicly available sources. A machine-learning model was built using Python software. RESULTS: The initial 110 audio samples used to test and train the model were retested after format conversion and file deidentification. Each sample was tested 5 times yielding a precision of 100%. Sensitivity was 92.73% (95% CI: 82.41%-97.98%) and specificity was 98.18% (95% CI: 90.28%-99.95%). One hundred thirteen prospective samples, which had not yet interacted with the model, were then tested. Precision was again 100% with a sensitivity of 88.89% (95% CI: 78.44%-95.41%) and a specificity of 66% (95% CI: 51.23%-78.79%). DISCUSSION: VPD affects nearly 100% of patients with unrepaired overt soft palatal clefts and up to 30% of patients who have undergone palatoplasty. VPD can render patients unintelligible, thereby accruing significant psychosocial morbidity. The true burden of VPD in LMICs is unknown, and likely exceeds estimates from HICs. The ability to access a phone-based screening machine-learning model could expand access to diagnostic, and potentially therapeutic modalities for an innumerable amount of patients worldwide who suffer from VPD.

13.
Chembiochem ; 24(11): e202200774, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36917207

RESUMO

The targeting of bioactive molecules and probes to mitochondria can be achieved by coupling to the lipophilic triphenyl phosphonium (TPP) cation, which accumulates several hundred-fold within mitochondria in response to the mitochondrial membrane potential (Δψm ). Typically, a simple alkane links the TPP to its "cargo", increasing overall hydrophobicity. As it would be beneficial to enhance the water solubility of mitochondria-targeted compounds we explored the effects of replacing the alkyl linker with a polyethylene glycol (PEG). We found that the use of PEG led to compounds that were readily taken up by isolated mitochondria and by mitochondria inside cells. Within mitochondria the PEG linker greatly decreased adsorption of the TPP constructs to the matrix-facing face of the mitochondrial inner membrane. These findings will allow the distribution of mitochondria-targeted TPP compounds within mitochondria to be fine-tuned.


Assuntos
Mitocôndrias , Polietilenoglicóis , Interações Hidrofóbicas e Hidrofílicas , Compostos Organofosforados/farmacologia
14.
J Exp Biol ; 226(9)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37066839

RESUMO

Extremely anoxia-tolerant animals, such as freshwater turtles, survive anoxia and reoxygenation without sustaining tissue damage to their hearts. In contrast, for mammals, the ischemia-reperfusion (IR) injury that leads to tissue damage during a heart attack is initiated by a burst of superoxide (O2·-) production from the mitochondrial respiratory chain upon reperfusion of ischemic tissue. Whether turtles avoid oxidative tissue damage because of an absence of mitochondrial superoxide production upon reoxygenation, or because the turtle heart is particularly protected against this damage, is unclear. Here, we investigated whether there was an increase in mitochondrial O2·- production upon the reoxygenation of anoxic red-eared slider turtle hearts in vivo and in vitro. This was done by measuring the production of H2O2, the dismutation product of O2·-, using the mitochondria-targeted mass-spectrometric probe in vivo MitoB, while in parallel assessing changes in the metabolites driving mitochondrial O2·- production, succinate, ATP and ADP levels during anoxia, and H2O2 consumption and production rates of isolated heart mitochondria. We found that there was no excess production of in vivo H2O2 during 1 h of reoxygenation in turtles after 3 h anoxia at room temperature, suggesting that turtle hearts most likely do not suffer oxidative injury after anoxia because their mitochondria produce no excess O2·- upon reoxygenation. Instead, our data support the conclusion that both the low levels of succinate accumulation and the maintenance of ADP levels in the anoxic turtle heart are key factors in preventing the surge of O2·- production upon reoxygenation.


Assuntos
Tartarugas , Animais , Espécies Reativas de Oxigênio/metabolismo , Tartarugas/metabolismo , Superóxidos/metabolismo , Peróxido de Hidrogênio/metabolismo , Hipóxia/metabolismo , Mitocôndrias Cardíacas/metabolismo , Ácido Succínico/metabolismo , Succinatos/metabolismo , Mamíferos/metabolismo
15.
Trends Biochem Sci ; 43(11): 921-932, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30131192

RESUMO

Thousands of protein acyl modification sites have now been identified in vivo. However, at most sites the acylation stoichiometry is low, making functional enzyme-driven regulation in the majority of cases unlikely. As unmediated acylation can occur on the surface of proteins when acyl-CoA thioesters react with nucleophilic cysteine and lysine residues, slower nonenzymatic processes likely underlie most protein acylation. Here, we review how nonenzymatic acylation of nucleophilic lysine and cysteine residues occurs; the factors that enhance acylation at particular sites; and the strategies that have evolved to limit protein acylation. We conclude that protein acylation is an unavoidable consequence of the central role of reactive thioesters in metabolism. Finally, we propose a hypothesis for why low-stoichiometry protein acylation is selected against by evolution and how it might contribute to degenerative processes such as aging.


Assuntos
Acil Coenzima A/metabolismo , Cisteína/metabolismo , Lisina/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , Acil Coenzima A/química , Acilação , Animais , Cisteína/química , Humanos , Lisina/química , Proteínas/química
16.
Br J Cancer ; 127(2): 337-349, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35462561

RESUMO

BACKGROUND: Breast cancer remains a leading cause of death in women and novel imaging biomarkers are urgently required. Here, we demonstrate the diagnostic and treatment-monitoring potential of non-invasive sodium (23Na) MRI in preclinical models of breast cancer. METHODS: Female Rag2-/- Il2rg-/- and Balb/c mice bearing orthotopic breast tumours (MDA-MB-231, EMT6 and 4T1) underwent MRI as part of a randomised, controlled, interventional study. Tumour biology was probed using ex vivo fluorescence microscopy and electrophysiology. RESULTS: 23Na MRI revealed elevated sodium concentration ([Na+]) in tumours vs non-tumour regions. Complementary proton-based diffusion-weighted imaging (DWI) linked elevated tumour [Na+] to increased cellularity. Combining 23Na MRI and DWI measurements enabled superior classification accuracy of tumour vs non-tumour regions compared with either parameter alone. Ex vivo assessment of isolated tumour slices confirmed elevated intracellular [Na+] ([Na+]i); extracellular [Na+] ([Na+]e) remained unchanged. Treatment with specific inward Na+ conductance inhibitors (cariporide, eslicarbazepine acetate) did not affect tumour [Na+]. Nonetheless, effective treatment with docetaxel reduced tumour [Na+], whereas DWI measures were unchanged. CONCLUSIONS: Orthotopic breast cancer models exhibit elevated tumour [Na+] that is driven by aberrantly elevated [Na+]i. Moreover, 23Na MRI enhances the diagnostic capability of DWI and represents a novel, non-invasive biomarker of treatment response with superior sensitivity compared to DWI alone.


Assuntos
Neoplasias da Mama , Sódio , Animais , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/tratamento farmacológico , Meios de Contraste , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Camundongos
17.
J Synchrotron Radiat ; 29(Pt 4): 1004-1013, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35787567

RESUMO

The DIAD beamline for Dual Imaging and Diffraction at Diamond Light Source has opted to use an industrial robot to position its Dectris Pilatus 2M CdTe diffraction detector. This setup was chosen to enable flexible positioning of the detector in a quarter-sphere around the sample position whilst reliably holding the large weight of 139 kg of detector, detector mount and cabling in a stable position. Metrology measurements showed that the detector can be positioned with a linear repeatability of <19.7 µm and a rotational repeatability of <16.3 µrad. The detector position stays stable for a 12 h period with <10.1 µm of movement for linear displacement and <3.8 µrad for rotational displacement. X-ray diffraction from calibration samples confirmed that the robot is sufficiently stable to resolve lattice d-spacings within the instrumental broadening given by detector position and beam divergence.

18.
Int J Obes (Lond) ; 46(1): 137-143, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34552207

RESUMO

BACKGROUND: Early postnatal overfeeding (PO) induces long-term overweight and reduces brown adipose tissue (BAT) thermogenesis. Exercise has been suggested as a possible intervention to increase BAT function. In this study, we investigated chronical effects of moderate-intensity exercise in BAT function in postnatal overfed male Wistar rats METHODS: Litters' delivery was on postnatal-day 0 - PN0. At PN2, litters were adjusted to nine (normal litter - NL) or three pups (small litter - SL) per dam. Animals were weaned on PN21 and in PN30 randomly divided into sedentary (NL-Sed and SL-Sed) or exercised (NL-Exe and SL-Exe), N of 14 litters per group. Exercise protocol started (PN30) with an effort test; training sessions were performed three times weekly at 60% of the VO2max achieved in effort test, until PN80. On PN81, a temperature transponder was implanted beneath the interscapular BAT, whose temperature was assessed in periods of lights-on and -off from PN87 to PN90. Sympathetic nerve activation of BAT was registered at PN90. Animals were euthanized at PN91 and tissues collected RESULTS: PO impaired BAT thermogenesis in lights-on (pPO < 0.0001) and -off (pPO < 0.01). Exercise increased BAT temperature in lights-on (pExe < 0.0001). In NL-Exe, increased BAT activity was associated with higher sympathetic activity (pExe < 0.05), ß3-AR (pExe < 0.001), and UCP1 (pExe < 0.001) content. In SL-Exe, increasing BAT thermogenesis is driven by a combination of tissue morphology remodeling (pExe < 0.0001) with greater effect in increasing UCP1 (pExe < 0.001) and increased ß3-AR (pExe < 0.001) content. CONCLUSION: Moderate exercise chronically increased BAT thermogenesis in both, NL and SL groups. In NL-Exe by increasing Sympathetic activity, and in SL-Exe by a combination of increased ß3-AR and UCP1 content with morphologic remodeling of BAT. Chronically increasing BAT thermogenesis in obese subjects may lead to higher overall energy expenditure, favoring the reduction of obesity and related comorbidities.


Assuntos
Tecido Adiposo Marrom/metabolismo , Obesidade/fisiopatologia , Condicionamento Físico Animal/fisiologia , Animais , Brasil , Modelos Animais de Doenças , Camundongos , Obesidade/diagnóstico , Condicionamento Físico Animal/métodos , Ratos Wistar/crescimento & desenvolvimento , Ratos Wistar/metabolismo
19.
Anesthesiology ; 136(6): 901-915, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35188958

RESUMO

BACKGROUND: Residual neuromuscular blockade can be avoided with quantitative neuromuscular monitoring. The authors embarked on a professional practice initiative to attain documented train-of-four ratios greater than or equal to 0.90 in all patients for improved patient outcomes through reducing residual paralysis. METHODS: The authors utilized equipment trials, educational videos, quantitative monitors in all anesthetizing locations, and electronic clinical decision support with real-time alerts, and initiated an ongoing professional practice metric. This was a retrospective assessment (2016 to 2020) of train-of-four ratios greater than or equal to 0.9 that were documented before extubation. Anesthesia records were manually reviewed for neuromuscular blockade management details. Medical charts of surgical patients who received a neuromuscular blocking drug were electronically searched for patient characteristics and outcomes. RESULTS: From pre- to postimplementation, more patients were assigned American Society of Anesthesiologists Physical Status III to V, fewer were inpatients, the rocuronium average dose was higher, and more patients had a prereversal train-of-four count less than 4. Manually reviewed anesthesia records (n = 2,807) had 2 of 172 (1%) cases with documentation of train-of-four ratios greater than or equal to 0.90 in November 2016, which was fewer than the cases in December 2020 (250 of 269 [93%]). Postimplementation (February 1, 2020, to December 31, 2020), sugammadex (650 of 935 [70%]), neostigmine (195 of 935 [21%]), and no reversal (90 of 935 [10%]) were used to attain train-of-four ratios greater than or equal to 0.90 in 856 of 935 (92%) of patients. In the electronically searched medical charts (n = 20,181), postimplementation inpatients had shorter postanesthesia care unit lengths of stay (7% difference; median [in min] [25th, 75th interquartile range], 73 [55, 102] to 68 [49, 95]; P < 0.001), pulmonary complications were less (43% difference; 94 of 4,138 [2.3%] to 23 of 1,817 [1.3%]; P = 0.010; -1.0% difference [95% CI, -1.7 to -0.3%]), and hospital length of stay was shorter (median [in days] [25th, 75th], 3 [2, 5] to 2 [1, 4]; P < 0.001). CONCLUSIONS: In this professional practice initiative, documentation of train-of-four ratios greater than or equal to 0.90 occurred for 93% of patients in a busy clinical practice. Return-of-strength documentation is an intermediate outcome, and only one of many factors contributing to patient outcomes.


Assuntos
Bloqueio Neuromuscular , Fármacos Neuromusculares não Despolarizantes , Humanos , Neostigmina , Bloqueio Neuromuscular/efeitos adversos , Monitoração Neuromuscular , Fármacos Neuromusculares não Despolarizantes/efeitos adversos , Prática Profissional , Estudos Retrospectivos
20.
Cardiovasc Drugs Ther ; 36(1): 1-13, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-32648168

RESUMO

PURPOSE: Mitochondrial reactive oxygen species (ROS) production upon reperfusion of ischemic tissue initiates the ischemia/reperfusion (I/R) injury associated with heart attack. During ischemia, succinate accumulates and its oxidation upon reperfusion by succinate dehydrogenase (SDH) drives ROS production. Inhibition of succinate accumulation and/or oxidation by dimethyl malonate (DMM), a cell permeable prodrug of the SDH inhibitor malonate, can decrease I/R injury. However, DMM is hydrolysed slowly, requiring administration to the heart prior to ischemia, precluding its administration to patients at the point of reperfusion, for example at the same time as unblocking a coronary artery following a heart attack. To accelerate malonate delivery, here we developed more rapidly hydrolysable malonate esters. METHODS: We synthesised a series of malonate esters and assessed their uptake and hydrolysis by isolated mitochondria, C2C12 cells and in mice in vivo. In addition, we assessed protection against cardiac I/R injury by the esters using an in vivo mouse model of acute myocardial infarction. RESULTS: We found that the diacetoxymethyl malonate diester (MAM) most rapidly delivered large amounts of malonate to cells in vivo. Furthermore, MAM could inhibit mitochondrial ROS production from succinate oxidation and was protective against I/R injury in vivo when added at reperfusion. CONCLUSIONS: The rapidly hydrolysed malonate prodrug MAM can protect against cardiac I/R injury in a clinically relevant mouse model.


Assuntos
Cardiotônicos/farmacologia , Malonatos/farmacologia , Infarto do Miocárdio/prevenção & controle , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Animais , Cardiotônicos/síntese química , Cardiotônicos/química , Linhagem Celular , Modelos Animais de Doenças , Ésteres/química , Feminino , Humanos , Masculino , Malonatos/síntese química , Malonatos/química , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Pró-Fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Ácido Succínico/metabolismo
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