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2.
Urol Oncol ; 42(8): 245.e9-245.e18, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38724349

RESUMO

OBJECTIVE: To evaluate the real-world added value of androgen deprivation therapy (ADT) in addition to external beam radiotherapy (EBRT) in men with high-risk non-metastatic prostate cancer, in view of advances in radiotherapy and diagnostics. METHODS: All Dutch men diagnosed with high-risk non-metastatic prostate cancer (defined as: ≥cT2c-T3b N0M0, PSA ≥20-50 ng/ml, and/or Gleason score ≥8 (International Society of Urological Pathology [ISUP] grade ≥4)) from 2009 through 2019 and treated with EBRT with or without ADT were identified in the population-based Netherlands Cancer Registry. Propensity scores were used to match (1:1) men that received ADT to men that did not receive ADT. Subsequently, OS was compared. Analyses were also stratified by number of high-risk features, 1 (either ≥cT2c, PSA >20 ng/ml or Gleason score ≥8) versus ≥2 (out of ≥cT2c, PSA >20 ng/ml and Gleason score ≥8). RESULTS: A total of 14,773 men with high-risk non-metastatic prostate cancer were identified, 3,958 (27%) of which received EBRT alone. After matching, 3,427 men remained in both groups and baseline characteristics were well-balanced. After a median follow-up of 92 months, OS was better in men treated with EBRT and ADT compared to men treated with EBRT alone (10-year OS: 66.4% versus 61.8%; HR 0.88 [95%CI: 0.80-0.96]). There was no statistically significant difference in OS in the subgroup of men with only 1 high-risk feature (10-year OS 67.7% versus 64.9%; HR 0.95 [95%CI: 0.85-1.07]). CONCLUSIONS: In a contemporary cohort of men treated for high-risk non-metastatic prostate cancer with EBRT, an OS benefit of adding ADT was only observed in men with at least 2 high-risk features. These results suggest that improvements in diagnostics and treatment in recent decades have resulted in a stage shift of men benefiting from the addition of ADT to EBRT.


Assuntos
Antagonistas de Androgênios , Neoplasias da Próstata , Humanos , Masculino , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Neoplasias da Próstata/tratamento farmacológico , Antagonistas de Androgênios/uso terapêutico , Idoso , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Taxa de Sobrevida , Dosagem Radioterapêutica , Estudos Retrospectivos , Terapia Combinada
3.
Front Allergy ; 5: 1355324, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38487467

RESUMO

Background: Half (49%) of clinically diagnosed allergic rhinitis (AR) patients are sensitized to house dust mite (HDM). If allergen avoidance and symptomatic medication fail, allergen immunotherapy may be indicated. Objective: We investigated safety and tolerability of HDM-sublingual immunotherapy by HDM-SLIT tablets in Dutch daily clinical practice. Methods: Daily intake of 12 SQ-HDM SLIT-tablet was investigated in a prospective, multicenter, observational study (EUPAS43753). It comprised 4 consultations in 1 year. Data on safety, tolerability, treatment satisfaction, symptomatic medication, compliance, and clinical effectiveness (Control of Allergic Rhinitis and Asthma Test; CARAT) were collected. Descriptive and longitudinal regression data analysis were performed. Results: Adult patients (n = 415), mean (SD) age 36.6 (12.2) years, 61.4% female and 36% asthmatic were included. The preponderance (65.1%) experienced adverse events (AEs). These, mostly mild (67%), AEs comprised: oral allergic reactions (58.6%), respiratory (12.4%) and gastrointestinal symptoms (9.4%). Sixty (14.5%) patients stopped due to AEs and 76 (18.3%) for non-AE reasons. CARAT scores improved clinically significant by 6 points and symptomatic medication use decreased from 96.1% to 77.4%. Most patients (74.5%) tolerated the treatment and were compliant (>86.5%). The majority of patients (62.4%) and investigators (69.4%) were satisfied with treatment. Conclusions: HDM SLIT-tablet is a safe and well-tolerated AR treatment. AEs occur often but are mostly mild and decreasing during the first year. CARAT scores improved and symptomatic medication use decreased suggesting better control of AR with treatment. Compliance, tolerability, and treatment satisfaction are good. However, patient follow-up and compliance remain important points of attention when initiating treatment.

4.
Eur Arch Psychiatry Clin Neurosci ; 274(2): 311-320, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37707566

RESUMO

BACKGROUND: Alcohol consumption to facilitate social interaction is an important drinking motive. Here, we tested whether alcohol influences trust in others via modulation of oxytocin and/or androgens. We also aimed at confirming previously shown alcohol effects on positive affect and risk-taking, because of their role in facilitating social interaction. METHODS: This randomized, controlled, within-subject, parallel group, alcohol-challenge experiment investigated the effects of alcohol (versus water, both mixed with orange juice) on perceived trustworthiness via salivary oxytocin (primary and secondary endpoint) as well as testosterone, dihydrotestosterone, positive affect, and risk-taking (additional endpoints). We compared 56 male participants in the alcohol condition (1.07 ± 0.18 per mille blood alcohol concentration) with 20 in the control condition. RESULTS: The group (alcohol versus control condition) × time (before [versus during] versus after drinking) interactions were not significantly associated with perceived trustworthiness (η2 < 0.001) or oxytocin (η2 = 0.003). Bayes factors provided also substantial evidence for the absence of these effects (BF01 = 3.65; BF01 = 7.53). The group × time interactions were related to dihydrotestosterone (η2 = 0.018 with an increase in the control condition) as well as positive affect and risk-taking (η2 = 0.027 and 0.007 with increases in the alcohol condition), but not significantly to testosterone. DISCUSSION: The results do not verify alcohol effects on perceived trustworthiness or oxytocin in male individuals. However, they indicate that alcohol (versus control) might inhibit an increase in dihydrotestosterone and confirm that alcohol amplifies positive affect and risk-taking. This provides novel mechanistic insight into social facilitation as an alcohol-drinking motive.


Assuntos
Consumo de Bebidas Alcoólicas , Ocitocina , Interação Social , Confiança , Humanos , Masculino , Teorema de Bayes , Concentração Alcoólica no Sangue , Di-Hidrotestosterona/metabolismo , Etanol , Ocitocina/metabolismo , Assunção de Riscos , Testosterona/metabolismo
5.
J Chem Theory Comput ; 19(22): 8013-8019, 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-37948626

RESUMO

We resolve a seeming paradox arising from a common misinterpretation of Ben-Naim's theorem, which rests on the decomposition of the Hamiltonian of a molecular solute/solvent system into solute-solvent and solvent-solvent interactions. According to this theorem, the solvation entropy can also be decomposed into a solute-solvent term and a remaining solvent-solvent term that is commonly referred to as the solvent reorganization term. Crucially, the latter equals the average solvent-solvent interaction energy such that these two solvent-solvent terms cancel and thus do not change the total solvation free energy. This analytical result implies that changes in the solvent-solvent interactions cannot contribute to any thermodynamic driving force. The solvent reorganization term is often identified with the contribution of many-body solvent correlations to the solvation entropy, which seems to imply that these correlations, too, cannot contribute to solvation. However, recent calculations based on atomistic simulations of a solvated globular protein and spatially resolved mutual information expansions revealed substantial contributions of many-body solvent correlations to the solvation free energy, which are not canceled by the enthalpy change of the solvent. Here, we resolved this seeming contradiction and illustrate by two examples─a simple Ising model and a solvated Lennard-Jones particle─that the solvent reorganization entropy and the actual entropy contribution arising from many-body solvent correlations differ both conceptually and numerically. Whereas the solvent reorganization entropy in fact arises from both solvent-solvent as well as solute-solvent interactions and thus has no straightforward intuitive interpretation, the mutual information expansion permits an interpretation in terms of the entropy contribution of solvent-solvent correlations to the solvation free energy.

6.
Expert Opin Drug Metab Toxicol ; 19(9): 635-652, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37728555

RESUMO

INTRODUCTION: Cisplatin is a very effective chemotherapeutic agent against a variety of solid tumors. Unfortunately, cisplatin causes permanent sensorineural hearing loss in at least two-thirds of patients treated. There are no FDA approved drugs to prevent this serious side effect. AREAS COVERED: This paper reviews various natural products that ameliorate cisplatin ototoxicity. These compounds are strong antioxidants and anti-inflammatory agents. This review includes mostly preclinical studies but also discusses a few small clinical trials with natural products to minimize hearing loss from cisplatin chemotherapy in patients. The interactions of natural products with cisplatin in tumor-bearing animal models are highlighted. A number of natural products did not interfere with cisplatin anti-tumor efficacy and some agents actually potentiated cisplatin anti-tumor activity. EXPERT OPINION: There are a number of natural products or their derivatives that show excellent protection against cisplatin ototoxicity in preclinical studies. There is a need to insure uniform standards for purity of drugs derived from natural sources and to ensure adequate pharmacokinetics and safety of these products. Natural products that protect against cisplatin ototoxicity and augment cisplatin's anti-tumor effects in multiple studies of tumor-bearing animals are most promising for advancement to clinical trials. The most promising natural products include honokiol, sulforaphane, and thymoquinone.

7.
Biomolecules ; 13(6)2023 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-37371553

RESUMO

BACKGROUND: Invasive dental treatment in patients exposed to antiresorptive and antiangiogenic drugs can cause medication-related osteonecrosis of the jaw (MRONJ). Currently, the exact pathogenesis of this disease is unclear. METHODS: In March 2022, Medline (Ovid), Embase (Ovid), Scopus, and Web of Science were screened to identify eligible in vitro studies investigating the effects of antiresorptive and antiangiogenic compounds on orally derived cells. RESULTS: Fifty-nine articles met the inclusion criteria. Bisphosphonates were used in 57 studies, denosumab in two, and sunitinib and bevacizumab in one. Zoledronate was the most commonly used nitrogen-containing bisphosphonate. The only non-nitrogen-containing bisphosphonate studied was clodronate. The most frequently tested tissues were gingival fibroblasts, oral keratinocytes, and alveolar osteoblasts. These drugs caused a decrease in cell proliferation, viability, and migration. CONCLUSIONS: Antiresorptive and antiangiogenic drugs displayed cytotoxic effects in a dose and time-dependent manner. Additional research is required to further elucidate the pathways of MRONJ.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Conservadores da Densidade Óssea , Humanos , Conservadores da Densidade Óssea/efeitos adversos , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/tratamento farmacológico , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/etiologia , Denosumab/efeitos adversos , Difosfonatos/farmacologia , Difosfonatos/uso terapêutico , Ácido Zoledrônico , Inibidores da Angiogênese/farmacologia , Inibidores da Angiogênese/uso terapêutico
8.
Front Immunol ; 14: 1125948, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37063917

RESUMO

Cisplatin is chemotherapy used for solid tumor treatment like lung, bladder, head and neck, ovarian and testicular cancers. However, cisplatin-induced ototoxicity limits the utility of this agent in cancer patients, especially when dose escalations are needed. Ototoxicity is associated with cochlear cell death through DNA damage, the generation of reactive oxygen species (ROS) and the consequent activation of caspase, glutamate excitotoxicity, inflammation, apoptosis and/or necrosis. Previous studies have demonstrated a role of CXC chemokines in cisplatin ototoxicity. In this study, we investigated the role of CXCL1, a cytokine which increased in the serum and cochlea by 24 h following cisplatin administration. Adult male Wistar rats treated with cisplatin demonstrated significant hearing loss, assessed by auditory brainstem responses (ABRs), hair cell loss and loss of ribbon synapse. Immunohistochemical studies evaluated the levels of CXCL1 along with increased presence of CD68 and CD45-positive immune cells in cochlea. Increases in CXCL1 was time-dependent in the spiral ganglion neurons and organ of Corti and was associated with progressive increases in CD45, CD68 and IBA1-positive immune cells. Trans-tympanic administration of SB225002, a chemical inhibitor of CXCR2 (receptor target for CXCL1) reduced immune cell migration, protected against cisplatin-induced hearing loss and preserved hair cell integrity. We show that SB225002 reduced the expression of CXCL1, NOX3, iNOS, TNF-α, IL-6 and COX-2. Similarly, knockdown of CXCR2 by trans-tympanic administration of CXCR2 siRNA protected against hearing loss and loss of outer hair cells and reduced ribbon synapses. In addition, SB225002 reduced the expression of inflammatory mediators induced by cisplatin. These results implicate the CXCL1 chemokine as an early player in cisplatin ototoxicity, possibly by initiating the immune cascade, and indicate that CXCR2 is a relevant target for treating cisplatin ototoxicity.


Assuntos
Perda Auditiva , Ototoxicidade , Ratos , Animais , Masculino , Cisplatino/efeitos adversos , Quimiocina CXCL1/genética , Ototoxicidade/tratamento farmacológico , Ototoxicidade/etiologia , Ratos Wistar , NADPH Oxidases/metabolismo , Perda Auditiva/induzido quimicamente , Perda Auditiva/metabolismo
9.
Bioorg Med Chem Lett ; 88: 129304, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-37119973

RESUMO

Derivatives of lactam, cyclic urea and carbamate were explored as aniline amide replacements in a series of phthalazinone-based ROCK inhibitors. Potent ROCK2 inhibitors such as 22 were identified with excellent overall kinase selectivity as well as good isoform selectivity over ROCK1.


Assuntos
Amidas , Lactamas , Quinases Associadas a rho , Lactamas/farmacologia , Isoformas de Proteínas , Quinases Associadas a rho/antagonistas & inibidores
10.
Transl Androl Urol ; 12(2): 241-248, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36915892

RESUMO

Background: Our objective was to assess the accuracy of transabdominal ultrasound (TAUS) measured prostate volume in the primary care setting with transrectal ultrasound (TRUS) measured prostate volume by the urologist as the reference test. Furthermore, our objective was to assess whether risk-stratification using TAUS prostate volume by the primary care physician could reduce unnecessary referrals to the urologist. Methods: Men in two Dutch primary care offices with a prostate cancer (PCa) screening request received a digital rectal examination (DRE), prostate specific-antigen (PSA), and TAUS prostate volume measurement by the general practitioner, followed by Rotterdam Prostate Cancer Risk Calculator (RPCRC) risk assessment. The examination was repeated by a urologist using TRUS. A prostate biopsy was performed in case of a RPCRC positive biopsy advice. A non-inferiority analysis was performed comparing TAUS and TRUS prostate volume differences. A risk-based referral strategy using TAUS and the RPCRC in the primary care setting was compared with the standard referral strategy based on PSA (≥3 ng/mL) and DRE. Results: A total of 105 men were included with a median PSA of 1.9 ng/mL. The mean prostate volumes measured by TAUS and TRUS were 55 and 45 mL, respectively. The mean overestimation of the prostate volume by TAUS as compared to the reference test was 9.9 mL (95% CI: 5.9-13.8). According to Dutch standard practice, 41 out of 105 (39%) men would have been referred to the urologist. Stratification in primary care based on the RPCRC using TAUS prostate volume would have avoided 29 out of the 41 (71%) referrals, at the expense of non-referral of 5 out of 11 (45%) men with a biopsy indication, according to the urologist. Conclusions: RPCRC-based risk stratification in primary care using TAUS prostate volume measurement is feasible and may prevent unnecessary referrals to the urologist and reduce costs. The accuracy of the risk assessment with TAUS might be improved by sufficient training and centralization to achieve a higher volume of consultations in primary care facilities.

11.
Ecol Indic ; 154: 1-15, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38274645

RESUMO

Ecosystem management requires a systematic, holistic approach that considers ecological and social outcomes. Effective restoration practices promote a balance of ecological and social goals by addressing ecological integrity, efficiently maximizing benefits while minimizing investment, and encompassing collaborative stakeholder engagement. Socio-ecological assessments can inform adaptive management and be utilized to prioritize restoration activities and monitor restoration effectiveness. In estuarine systems, socio-ecological assessments should evaluate the ability of habitats to support both ecologically and locally important species. The composite measure presented utilizes a combination of ecological and social measures to characterize ecological suitability for individual and multiple Gulf of Mexico estuarine species. The ecological suitability value (ES) for a given spatial unit is based on a suite of biophysical measures of the quality and extent of suitable habitat for each species, the species' trophic importance in a food web context, and the importance of each species in relation to stakeholder values and benefits. ES values for individual spatial units can be aggregated to estimate the distribution of ecological suitability at the estuarine scale. The ES values are calculated using examples for each step in the process. The information provided by ecological suitability characterizations can support restoration prioritization decisions for Gulf of Mexico estuaries and can provide a baseline measure to gauge restoration effectiveness over time to inform cumulative restoration assessments.

12.
Proc Natl Acad Sci U S A ; 119(28): e2204174119, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35787042

RESUMO

Myocardial fibrosis is a key pathologic feature of hypertrophic cardiomyopathy (HCM). However, the fibrotic pathways activated by HCM-causing sarcomere protein gene mutations are poorly defined. Because lysophosphatidic acid is a mediator of fibrosis in multiple organs and diseases, we tested the role of the lysophosphatidic acid pathway in HCM. Lysphosphatidic acid receptor 1 (LPAR1), a cell surface receptor, is required for lysophosphatidic acid mediation of fibrosis. We bred HCM mice carrying a pathogenic myosin heavy-chain variant (403+/-) with Lpar1-ablated mice to create mice carrying both genetic changes (403+/- LPAR1 -/-) and assessed development of cardiac hypertrophy and fibrosis. Compared with 403+/- LPAR1WT, 403+/- LPAR1 -/- mice developed significantly less hypertrophy and fibrosis. Single-nucleus RNA sequencing of left ventricular tissue demonstrated that Lpar1 was predominantly expressed by lymphatic endothelial cells (LECs) and cardiac fibroblasts. Lpar1 ablation reduced the population of LECs, confirmed by immunofluorescence staining of the LEC markers Lyve1 and Ccl21a and, by in situ hybridization, for Reln and Ccl21a. Lpar1 ablation also altered the distribution of fibroblast cell states. FB1 and FB2 fibroblasts decreased while FB0 and FB3 fibroblasts increased. Our findings indicate that Lpar1 is expressed predominantly by LECs and fibroblasts in the heart and is required for development of hypertrophy and fibrosis in an HCM mouse model. LPAR1 antagonism, including agents in clinical trials for other fibrotic diseases, may be beneficial for HCM.


Assuntos
Cardiomiopatia Hipertrófica , Receptores de Ácidos Lisofosfatídicos/genética , Animais , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/patologia , Proteínas de Transporte , Modelos Animais de Doenças , Células Endoteliais/patologia , Fibrose , Hipertrofia/patologia , Camundongos
15.
Medicines (Basel) ; 9(3)2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35323716

RESUMO

Background: the objective of this retrospective, cross sectional study was to assess the relationship between different levels of perceived health status and prescription medication expenditures among United States adults aged ≥50 years with self-reported pain. Methods: using 2019 Medical Expenditure Panel Survey (MEPS) data, four levels of perceived health status were formed (excellent, very good, good, and fair/poor health). Differences between characteristics in the groups were compared using chi square tests. Adjusted linear regression models, using logged positive annual prescription medication expenditures, were constructed to assess differences in prescription medication expenditures between levels of perceived health. Results: a total of 4826 individuals were included in the study. Adjusted linear regression analysis indicated those who reported excellent health had 65.8% lower annual prescription medication expenditures than those with fair/poor health. Those with very good health had 49.7% lower annual prescription medication expenditures than those with fair/poor health, while those with good health had 27.2% lower annual prescription medication expenditures than those with fair/poor health. Conclusions: better perceived health status was generally associated with relatively lower prescription medication expenditures. Further research is needed to investigate if this pattern is also observed for other categories of healthcare expenditures and in other populations.

16.
iScience ; 25(1): 103667, 2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35028538

RESUMO

Dysferlinopathies are muscular dystrophies caused by recessive loss-of-function mutations in dysferlin (DYSF), a membrane protein involved in skeletal muscle membrane repair. We describe a cell-based assay in which human DYSF proteins bearing missense mutations are quantitatively assayed for membrane localization by flow cytometry and identified 64 localization-defective DYSF mutations. Using this platform, we show that the clinically approved drug 4-phenylbutryric acid (4-PBA) partially restores membrane localization to 25 mutations, as well as membrane repair to cultured myotubes expressing 2 different mutations. Two-day oral administration of 4-PBA to mice homozygous for one of these mutations restored myofiber membrane repair. 4-PBA may hold therapeutic potential for treating a subset of humans with muscular dystrophy due to dysferlin deficiency.

17.
Antioxidants (Basel) ; 10(12)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34943021

RESUMO

Hearing loss is a significant health problem that can result from a variety of exogenous insults that generate oxidative stress and inflammation. This can produce cellular damage and impairment of hearing. Radiation damage, ageing, damage produced by cochlear implantation, acoustic trauma and ototoxic drug exposure can all generate reactive oxygen species in the inner ear with loss of sensory cells and hearing loss. Cisplatin ototoxicity is one of the major causes of hearing loss in children and adults. This review will address cisplatin ototoxicity. It includes discussion of the mechanisms associated with cisplatin-induced hearing loss including uptake pathways for cisplatin entry, oxidative stress due to overpowering antioxidant defense mechanisms, and the recently described toxic pathways that are activated by cisplatin, including necroptosis and ferroptosis. The cochlea contains G-protein coupled receptors that can be activated to provide protection. These include adenosine A1 receptors, cannabinoid 2 receptors (CB2) and the Sphingosine 1-Phosphate Receptor 2 (S1PR2). A variety of heat shock proteins (HSPs) can be up-regulated in the cochlea. The use of exosomes offers a novel method of delivery of HSPs to provide protection. A reversible MET channel blocker that can be administered orally may block cisplatin uptake into the cochlear cells. Several protective agents in preclinical studies have been shown to not interfere with cisplatin efficacy. Statins have shown efficacy in reducing cisplatin ototoxicity without compromising patient response to treatment. Additional clinical trials could provide exciting findings in the prevention of cisplatin ototoxicity.

18.
Rev Med Liege ; 76(7-8): 575-578, 2021 Jul.
Artigo em Francês | MEDLINE | ID: mdl-34357705

RESUMO

The authors report the case of a 41-year-old patient originating from Algeria who developed obstructive cholangitis caused by the membrane of a ruptured hydatid cyst leading to the diagnosis of cystic echinococcosis. Cystic echinococcosis can be asymptomatic for several years until a complication occurs, such as in this case an obstruction of the common bile duct, or cholangio-hydatidosis. This cause of jaundice is uncommon in Western Europe whereas it is more frequent in endemic areas. Identification and treatment of ruptured cysts are mandatory because of the mortality rate of these complications if left untreated. In this particular case, the treatment by endoscopic retrograde cholangiopancreatography was successful.


Les auteurs rapportent le cas d'un patient de 41 ans, originaire d'Algérie, chez qui un diagnostic d'échinococcose a été posé à la suite d'une cholangite obstructive sur rupture d'un kyste hydatique. L'échinococcose kystique peut être asymptomatique pendant plusieurs années jusqu'à ce qu'une complication ne survienne, comme une obstruction du canal cholédoque commun appelée également cholangio-hydatidose. Cette cause d'ictère est rare en Europe occidentale alors qu'elle est plus fréquente dans les zones endémiques. L'identification et le traitement des kystes rompus sont nécessaires en raison du taux de mortalité de ces complications lorsqu'elles ne sont pas traitées de manière adéquate. Dans ce cas particulier, le traitement par cholangio-pancréatographie rétrograde endoscopique s'est révélé efficace.


Assuntos
Colangite , Equinococose Hepática , Equinococose , Adulto , Colangiopancreatografia Retrógrada Endoscópica , Colangite/diagnóstico , Colangite/etiologia , Equinococose Hepática/complicações , Equinococose Hepática/diagnóstico , Humanos
19.
Biophys J ; 120(16): 3470-3482, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34087209

RESUMO

The folding stability of a protein is governed by the free-energy difference between its folded and unfolded states, which results from a delicate balance of much larger but almost compensating enthalpic and entropic contributions. The balance can therefore easily be shifted by an external disturbance, such as a mutation of a single amino acid or a change of temperature, in which case the protein unfolds. Effects such as cold denaturation, in which a protein unfolds because of cooling, provide evidence that proteins are strongly stabilized by the solvent entropy contribution to the free-energy balance. However, the molecular mechanisms behind this solvent-driven stability, their quantitative contribution in relation to other free-energy contributions, and how the involved solvent thermodynamics is affected by individual amino acids are largely unclear. Therefore, we addressed these questions using atomistic molecular dynamics simulations of the small protein Crambin in its native fold and a molten-globule-like conformation, which here served as a model for the unfolded state. The free-energy difference between these conformations was decomposed into enthalpic and entropic contributions from the protein and spatially resolved solvent contributions using the nonparametric method Per|Mut. From the spatial resolution, we quantified the local effects on the solvent free-energy difference at each amino acid and identified dependencies of the local enthalpy and entropy on the protein curvature. We identified a strong stabilization of the native fold by almost 500 kJ mol-1 due to the solvent entropy, revealing it as an essential contribution to the total free-energy difference of (53 ± 84) kJ mol-1. Remarkably, more than half of the solvent entropy contribution arose from induced water correlations.


Assuntos
Proteínas de Plantas , Dobramento de Proteína , Entropia , Conformação Proteica , Desnaturação Proteica , Termodinâmica
20.
Nat Commun ; 12(1): 3606, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127664

RESUMO

Membrane fusion is fundamental to biological processes as diverse as membrane trafficking or viral infection. Proteins catalyzing membrane fusion need to overcome energy barriers to induce intermediate steps in which the integrity of bilayers is lost. Here, we investigate the structural features of tightly docked intermediates preceding hemifusion. Using lipid vesicles in which progression to hemifusion is arrested, we show that the metastable intermediate does not require but is enhanced by divalent cations and is characterized by the absence of proteins and local membrane thickening. Molecular dynamics simulations reveal that thickening is due to profound lipid rearrangements induced by dehydration of the membrane surface.


Assuntos
Fusão de Membrana/fisiologia , Membranas/química , Simulação de Dinâmica Molecular , Animais , Fenômenos Biofísicos , Microscopia Crioeletrônica , Escherichia coli/genética , Bicamadas Lipídicas/química , Ratos , Proteínas SNARE/química , Proteínas SNARE/metabolismo
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