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1.
Eur Respir J ; 61(3)2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36396142

RESUMO

BACKGROUND: The primary aim of our study was to investigate the association between intubation timing and hospital mortality in critically ill patients with coronavirus disease 2019 (COVID-19)-associated respiratory failure. We also analysed both the impact of such timing throughout the first four pandemic waves and the influence of prior noninvasive respiratory support on outcomes. METHODS: This is a secondary analysis of a multicentre, observational and prospective cohort study that included all consecutive patients undergoing invasive mechanical ventilation due to COVID-19 from across 58 Spanish intensive care units (ICUs) participating in the CIBERESUCICOVID project. The study period was between 29 February 2020 and 31 August 2021. Early intubation was defined as that occurring within the first 24 h of ICU admission. Propensity score matching was used to achieve a balance across baseline variables between the early intubation cohort and those patients who were intubated after the first 24 h of ICU admission. Differences in outcomes between early and delayed intubation were also assessed. We performed sensitivity analyses to consider a different time-point (48 h from ICU admission) for early and delayed intubation. RESULTS: Of the 2725 patients who received invasive mechanical ventilation, a total of 614 matched patients were included in the analysis (307 for each group). In the unmatched population, there were no differences in mortality between the early and delayed groups. After propensity score matching, patients with delayed intubation presented higher hospital mortality (27.3% versus 37.1%; p=0.01), ICU mortality (25.7% versus 36.1%; p=0.007) and 90-day mortality (30.9% versus 40.2%; p=0.02) compared with the early intubation group. Very similar findings were observed when we used a 48-h time-point for early or delayed intubation. The use of early intubation decreased after the first wave of the pandemic (72%, 49%, 46% and 45% in the first, second, third and fourth waves, respectively; first versus second, third and fourth waves p<0.001). In both the main and sensitivity analyses, hospital mortality was lower in patients receiving high-flow nasal cannula (HFNC) (n=294) who were intubated earlier. The subgroup of patients undergoing noninvasive ventilation (n=214) before intubation showed higher mortality when delayed intubation was set as that occurring after 48 h from ICU admission, but not when after 24 h. CONCLUSIONS: In patients with COVID-19 requiring invasive mechanical ventilation, delayed intubation was associated with a higher risk of hospital mortality. The use of early intubation significantly decreased throughout the course of the pandemic. Benefits of such an approach occurred more notably in patients who had received HFNC.


Assuntos
COVID-19 , Ventilação não Invasiva , Insuficiência Respiratória , Humanos , Estudos Prospectivos , Pandemias , Intubação Intratraqueal/efeitos adversos , Respiração Artificial/efeitos adversos , Insuficiência Respiratória/terapia , Insuficiência Respiratória/etiologia , Unidades de Terapia Intensiva
2.
Artigo em Inglês | MEDLINE | ID: mdl-32205347

RESUMO

Carbapenemase-producing Enterobacterales and specifically Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp) are rapidly spreading worldwide. The prognosis of ventilator-associated pneumonia (VAP) caused by KPC-Kp is not well known. Our study tries to assess whether ventilator-associated pneumonia caused by a KPC-Kp strain is associated with higher all-cause mortality than that caused by carbapenem-susceptible isolates. This is a retrospective cohort study of patients with VAP due to K. pneumoniae from a 35-bed polyvalent intensive care unit in a university hospital (>40,000 annual admissions) between January 2012 and December 2016. Adjusted multivariate analysis was used to study the association of KPC-Kp with 30-day all-cause mortality (Cox regression). We analyze 69 cases of K. pneumoniae VAP, of which 39 were produced by a KPC-Kp strain with high-level resistance to meropenem (MIC > 16 mg/ml). All-cause mortality at 30 days was 41% in the KPC-Kp group (16/39) and 33.3% in the carbapenem-susceptible cases (10/30). KPC-Kp etiology was not associated with higher mortality when controlled for confounders (adjusted hazard ratio [HR], 1.25; 95% confidence interval [CI], 0.46 to 3.41). Adequate targeted therapy (HR, 0.03; 95% CI, <0.01 to 0.23) was associated with all-cause mortality. Assuming the limitations due to the available sample size, the prognosis of VAP caused by KPC-Kp is similar to VAPs caused by carbapenem-susceptible K. pneumoniae when appropriate treatment is used.


Assuntos
Infecções por Klebsiella , Pneumonia Associada à Ventilação Mecânica , Antibacterianos/uso terapêutico , Proteínas de Bactérias/genética , Humanos , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae , Meropeném/uso terapêutico , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Estudos Retrospectivos , beta-Lactamases/genética
3.
New Phytol ; 227(1): 200-215, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32129890

RESUMO

Root-knot nematodes (RKNs; Meloidogyne spp.) induce new post-embryogenic organs within the roots (galls) where they stablish and differentiate nematode feeding cells, giant cells (GCs). The developmental programmes and functional genes involved remain poorly defined. Arabidopsis root apical meristem (RAM), lateral root (LR) and callus marker lines, SHORT-ROOT/SHR, SCARECROW/SCR, SCHIZORIZA/SCZ, WUSCHEL-RELATED-HOMEOBOX-5/WOX5, AUXIN-RESPONSIVE-FACTOR-5/ARF5, ARABIDOPSIS-HISTIDINE PHOSPHOTRANSFER-PROTEIN-6/AHP6, GATA-TRANSCRIPTION FACTOR-23/GATA23 and S-PHASE-KINASE-ASSOCIATED-PROTEIN2B/SKP2B, were analysed for nematode-dependent expression. Their corresponding loss-of-function lines, including those for LR upstream regulators, SOLITARY ROOT/SLR/IAA14, BONDELOS/BDL/IAA12 and INDOLE-3-ACETIC-ACID-INDUCIBLE-28/IAA28, were tested for RKN resistance/tolerance. LR genes, for example ARF5 (key factor for root stem-cell niche regeneration), GATA23 (which specifies pluripotent founder cells) and AHP6 (cytokinin-signalling-inhibitor regulating pericycle cell-divisions orientation), show a crucial function during gall formation. RKNs do not compromise the number of founder cells or LR primordia but locally induce gall formation possibly by tuning the auxin/cytokinin balance in which AHP6 might be necessary. Key RAM marker genes were induced and functional in galls. Therefore, the activation of plant developmental programmes promoting transient-pluripotency/stemness leads to the generation of quiescent-centre and meristematic-like cell identities within the vascular cylinder of galls. Nematodes enlist developmental pathways of new organogenesis and/or root regeneration in the vascular cells of galls. This should determine meristematic cell identities with sufficient transient pluripotency for gall organogenesis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Animais , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Citocininas , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Raízes de Plantas/metabolismo
4.
Plant Physiol ; 176(2): 1709-1727, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29233938

RESUMO

Body regeneration through formation of new organs is a major question in developmental biology. We investigated de novo root formation using whole leaves of Arabidopsis (Arabidopsis thaliana). Our results show that local cytokinin biosynthesis and auxin biosynthesis in the leaf blade followed by auxin long-distance transport to the petiole leads to proliferation of J0121-marked xylem-associated tissues and others through signaling of INDOLE-3-ACETIC ACID INDUCIBLE28 (IAA28), CRANE (IAA18), WOODEN LEG, and ARABIDOPSIS RESPONSE REGULATORS1 (ARR1), ARR10, and ARR12. Vasculature proliferation also involves the cell cycle regulator KIP-RELATED PROTEIN2 and ABERRANT LATERAL ROOT FORMATION4, resulting in a mass of cells with rooting competence that resembles callus formation. Endogenous callus formation precedes specification of postembryonic root founder cells, from which roots are initiated through the activity of SHORT-ROOT, PLETHORA1 (PLT1), and PLT2. Primordia initiation is blocked in shr plt1 plt2 mutant. Stem cell regulators SCHIZORIZA, JACKDAW, BLUEJAY, and SCARECROW also participate in root initiation and are required to pattern the new organ, as mutants show disorganized and reduced number of layers and tissue initials resulting in reduced rooting. Our work provides an organ regeneration model through de novo root formation, stating key stages and the primary pathways involved.


Assuntos
Arabidopsis/genética , Reprogramação Celular , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Transdução de Sinais , Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Modelos Biológicos , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Regeneração
5.
Artigo em Inglês | MEDLINE | ID: mdl-27895014

RESUMO

Ceftazidime-avibactam (CAZ-AVI) is a recently approved ß-lactam-ß-lactamase inhibitor combination with the potential to treat serious infections caused by carbapenem-resistant organisms. Few patients with such infections were included in the CAZ-AVI clinical trials, and clinical experience is lacking. We present a case series of patients with infections caused by carbapenem-resistant Enterobacteriaceae (CRE) or Pseudomonas aeruginosa (CRPa) who were treated with CAZ-AVI salvage therapy on a compassionate-use basis. Physicians who had prescribed CAZ-AVI completed a case report form. We used descriptive statistics to summarize patient characteristics and treatment outcomes. We used the Wilcoxon rank sum test and Fisher's exact test to compare patients by treatment outcome. The sample included 36 patients infected with CRE and two with CRPa. The most common infections were intra-abdominal. Physicians categorized 60.5% of patients as having life-threatening infections. All but two patients received other antibiotics before CAZ-AVI, for a median of 13 days. The median duration of CAZ-AVI treatment was 16 days. Twenty-five patients (65.8%) concurrently received other antibiotics to which their pathogen was nonresistant in vitro Twenty-eight patients (73.7%, 95% confidence interval [CI], 56.9 to 86.6%) experienced clinical and/or microbiological cure. Five patients (20.8%) with documented microbiological cure died, whereas 10 patients (71.4%) with no documented microbiological cure died (P = 0.01). In three-quarters of cases, CAZ-AVI (alone or combined with other antibiotics) cured infections caused by carbapenem-resistant organisms, 95% of which had failed previous therapy. Microbiological cure was associated with improved survival. CAZ-AVI shows promising clinical results for infections for which treatment options are limited.


Assuntos
Antibacterianos/uso terapêutico , Compostos Azabicíclicos/uso terapêutico , Carbapenêmicos/uso terapêutico , Ceftazidima/uso terapêutico , Idoso , Antibacterianos/farmacologia , Compostos Azabicíclicos/farmacologia , Carbapenêmicos/farmacologia , Ceftazidima/farmacologia , Combinação de Medicamentos , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/patogenicidade , Feminino , Humanos , Klebsiella oxytoca/efeitos dos fármacos , Klebsiella oxytoca/patogenicidade , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/patogenicidade , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Terapia de Salvação
6.
Liver Transpl ; 22(4): 427-35, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26709146

RESUMO

Targeted prophylaxis has proven to be an efficient strategy in liver transplantation recipients (LTRs). The aim of this study was to compare the effectiveness and safety of caspofungin with that of fluconazole in high-risk (HR) LTRs. Caspofungin and fluconazole were compared in a multicenter, retrospective, cohort study in HR-LTRs in Spain. Outcomes were assessed at 180 days after transplantation. A propensity score approach was applied. During the study period (2005-2012), we analyzed 195 HR-LTRs from 9 hospitals. By type of prophylaxis, 97 patients received caspofungin and 98 received fluconazole. Of a total of 17 (8.7%) global invasive fungal infections (IFIs), breakthrough IFIs accounted for 11 (5.6%) and invasive aspergillosis (IA) accounted for 6 (3.1%). By univariate analysis, no differences were observed in the prevention of global IFIs. However, caspofungin was associated with a significant reduction in the rate of breakthrough IFIs (2.1% versus 9.2%, P = 0.04). In patients requiring dialysis (n = 62), caspofungin significantly reduced the frequency of breakthrough IFIs (P = 0.03). The propensity score analysis confirmed a significant reduction in the frequency of IA in patients receiving caspofungin (absolute risk reduction, 0.06; 95% confidence interval [CI], 0.001-0.11; P = 0.044). Linear regression analysis revealed a significant decrease in blood alanine aminotransferase levels and a significant increase in bilirubin levels after administration of caspofungin. Caspofungin and fluconazole have similar efficacy for the prevention of global IFIs in HR-LTRs in this observational, multicenter cohort study. However, caspofungin was associated with a significant reduction of breakthrough IFIs and, after adjusting for confounders, caspofungin was associated with a lower rate of IA. This benefit is probably more favorable in patients on dialysis. Caspofungin is safe in HR-LTRs, although bilirubin levels may be increased.


Assuntos
Antifúngicos/uso terapêutico , Aspergilose/prevenção & controle , Equinocandinas/uso terapêutico , Fluconazol/uso terapêutico , Infecções Fúngicas Invasivas/prevenção & controle , Lipopeptídeos/uso terapêutico , Transplante de Fígado/efeitos adversos , Adulto , Idoso , Alanina Transaminase/sangue , Aspergilose/epidemiologia , Bilirrubina/sangue , Caspofungina , Estudos de Coortes , Equinocandinas/efeitos adversos , Feminino , Humanos , Infecções Fúngicas Invasivas/epidemiologia , Lipopeptídeos/efeitos adversos , Hepatopatias/cirurgia , Masculino , Pessoa de Meia-Idade , Profilaxia Pré-Exposição/métodos , Pontuação de Propensão , Estudos Retrospectivos , Risco , Espanha/epidemiologia , Resultado do Tratamento , Adulto Jovem
7.
J Exp Bot ; 66(22): 6991-7003, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26417017

RESUMO

Polyploidy is a common event in plants that involves the acquisition of more than two complete sets of chromosomes. Allopolyploidy originates from interspecies hybrids while autopolyploidy originates from intraspecies whole genome duplication (WGD) events. In spite of inconveniences derived from chromosomic rearrangement during polyploidization, natural plant polyploids species often exhibit improved growth vigour and adaptation to adverse environments, conferring evolutionary advantages. These advantages have also been incorporated into crop breeding programmes. Many tetraploid crops show increased stress tolerance, although the molecular mechanisms underlying these different adaptation abilities are poorly known. Understanding the physiological, cellular, and molecular mechanisms coupled to WGD, in both allo- and autopolyploidy, is a major challenge. Over the last few years, several studies, many of them in Arabidopsis, are shedding light on the basis of genetic, genomic, and epigenomic changes linked to WGD. In this review we summarize and discuss the latest advances made in Arabidopsis polyploidy, but also in other agronomic plant species.


Assuntos
Arabidopsis/genética , Genoma de Planta , Poliploidia
9.
Plant Physiol ; 158(2): 777-89, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22167118

RESUMO

Plants exploit ubiquitination to modulate the proteome with the final aim to ensure environmental adaptation and developmental plasticity. Ubiquitination targets are specifically driven to degradation through the action of E3 ubiquitin ligases. Genetic analyses have indicated wide functions of ubiquitination in plant life; nevertheless, despite the large number of predicted E3s, only a few of them have been characterized so far, and only a few ubiquitination targets are known. In this work, we characterized durum wheat (Triticum durum) RING Finger1 (TdRF1) as a durum wheat nuclear ubiquitin ligase. Moreover, its barley (Hordeum vulgare) homolog was shown to protect cells from dehydration stress. A protein network interacting with TdRF1 has been defined. The transcription factor WHEAT BEL1-TYPE HOMEODOMAIN1 (WBLH1) was degraded in a TdRF1-dependent manner through the 26S proteasome in vivo, the mitogen-activated protein kinase TdWNK5 [for Triticum durum WITH NO LYSINE (K)5] was able to phosphorylate TdRF1 in vitro, and the RING-finger protein WHEAT VIVIPAROUS-INTERACTING PROTEIN2 (WVIP2) was shown to have a strong E3 ligase activity. The genes coding for the TdRF1 interactors were all responsive to cold and/or dehydration stress, and a negative regulative function in dehydration tolerance was observed for the barley homolog of WVIP2. A role in the control of plant development was previously known, or predictable based on homology, for wheat BEL1-type homeodomain1(WBLH1). Thus, TdRF1 E3 ligase might act regulating the response to abiotic stress and remodeling plant development in response to environmental constraints.


Assuntos
Proteínas de Plantas/metabolismo , Triticum/enzimologia , Ubiquitina-Proteína Ligases/metabolismo , Sequência de Aminoácidos , Western Blotting , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Fosforilação , Proteínas de Plantas/química , Ligação Proteica , Triticum/citologia
10.
Plant Commun ; 4(6): 100737, 2023 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-37865820

RESUMO

Plant growth and development involve the specification and regeneration of stem cell niches (SCNs). Although plants are exposed to disparate environmental conditions, how environmental cues affect developmental programs and stem cells is not well understood. Root stem cells are accommodated in meristems in SCNs around the quiescent center (QC), which maintains their activity. Using a combination of genetics and confocal microscopy to trace morphological defects and correlate them with changes in gene expression and protein levels, we show that the cold-induced transcription factor (TF) C-REPEAT BINDING FACTOR 3 (CBF3), which has previously been associated with cold acclimation, regulates root development, stem cell activity, and regeneration. CBF3 is integrated into the SHORT-ROOT (SHR) regulatory network, forming a feedback loop that maintains SHR expression. CBF3 is primarily expressed in the root endodermis, whereas the CBF3 protein is localized to other meristematic tissues, including root SCNs. Complementation of cbf3-1 using a wild-type CBF3 gene and a CBF3 fusion with reduced mobility show that CBF3 movement capacity is required for SCN patterning and regulates root growth. Notably, cold induces CBF3, affecting QC activity. Furthermore, exposure to moderate cold around 10°C-12°C promotes root regeneration and QC respecification in a CBF3-dependent manner during the recuperation period. By contrast, CBF3 does not appear to regulate stem cell survival, which has been associated with recuperation from more acute cold (∼4°C). We propose a role for CBF3 in mediating the molecular interrelationships among the cold response, stem cell activity, and development.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Plantas/metabolismo , Células-Tronco
11.
Crit Care ; 15(1): R66, 2011 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-21342489

RESUMO

INTRODUCTION: Little information exists about the impact of acute kidney injury (AKI) in critically ill patients with the pandemic 2009 influenza A (H1N1) virus infection. METHODS: We conducted a prospective, observational, multicenter study in 148 Spanish intensive care units (ICUs). Patients with chronic renal failure were excluded. AKI was defined according to Acute Kidney Injury Network (AKIN) criteria. RESULTS: A total of 661 patients were analyzed. One hundred eighteen (17.7%) patients developed AKI; of these, 37 (31.4%) of the patients with AKI were classified as AKI I, 15 (12.7%) were classified as AKI II and 66 (55.9%) were classified as AKI III, among the latter of whom 50 (75.7%) required continuous renal replacement therapy. Patients with AKI had a higher Acute Physiology and Chronic Health Evaluation II score (19.2 ± 8.3 versus 12.6 ± 5.9; P < 0.001), a higher Sequential Organ Failure Assessment score (8.7 ± 4.2 versus 4.8 ± 2.9; P < 0.001), more need for mechanical ventilation (MV) (87.3% versus 56.2%; P < 0.01, odds ratio (OR) 5.3, 95% confidence interval (CI) 3.0 to 9.4), a greater incidence of shock (75.4% versus 38.3%; P < 0.01, OR 4.9, 95% CI, 3.1 to 7.7), a greater incidence of multiorgan dysfunction syndrome (92.4% versus 54.7%; P < 0.01, OR 10.0, 95% CI, 4.9 to 20.21) and a greater incidence of coinfection (23.7% versus 14.4%; P < 0.01, OR 1.8, 95% CI, 1.1 to 3.0). In survivors, patients with AKI remained on MV longer and ICU and hospital length of stay were longer than in patients without AKI. The overall mortality was 18.8% and was significantly higher for AKI patients (44.1% versus 13.3%; P < 0.01, OR 5.1, 95% CI, 3.3 to 7.9). Logistic regression analysis was performed with AKIN criteria, and it demonstrated that among patients with AKI, only AKI III was independently associated with higher ICU mortality (P < 0.001, OR 4.81, 95% CI 2.17 to 10.62). CONCLUSIONS: In our cohort of patients with H1N1 virus infection, only those cases in the AKI III category were independently associated with mortality.


Assuntos
Injúria Renal Aguda/epidemiologia , Estado Terminal/epidemiologia , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/epidemiologia , Injúria Renal Aguda/mortalidade , Injúria Renal Aguda/fisiopatologia , Adulto , Estado Terminal/mortalidade , Feminino , Humanos , Influenza Humana/mortalidade , Influenza Humana/fisiopatologia , Unidades de Terapia Intensiva/tendências , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
12.
Enferm Infecc Microbiol Clin ; 29 Suppl 4: 36-41, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21458718

RESUMO

The present article is an update of the literature on invasive fungal infections caused by filamentous fungi in critically ill patients. A multidisciplinary group of Spanish physicians with an interest in these infections organized a joint session and selected the most important papers produced lately in the field. Each article was analyzed and discussed by one of the members of the panel. Studies from the fields of causative microorganisms, epidemiology, and diagnosis are discussed; including the assessment of different strategies for the early identification and treatment of patients at risk of fungal infections by filamentous fungi in the intensive care unit setting.


Assuntos
Estado Terminal , Fungos , Micoses/microbiologia , Cuidados Críticos/tendências , Humanos , Micoses/diagnóstico , Micoses/tratamento farmacológico , Micoses/epidemiologia
13.
Sci Adv ; 7(1)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33523850

RESUMO

In Arabidopsis, the root clock regulates the spacing of lateral organs along the primary root through oscillating gene expression. The core molecular mechanism that drives the root clock periodicity and how it is modified by exogenous cues such as auxin and gravity remain unknown. We identified the key elements of the oscillator (AUXIN RESPONSE FACTOR 7, its auxin-sensitive inhibitor IAA18/POTENT, and auxin) that form a negative regulatory loop circuit in the oscillation zone. Through multilevel computer modeling fitted to experimental data, we explain how gene expression oscillations coordinate with cell division and growth to create the periodic pattern of organ spacing. Furthermore, gravistimulation experiments based on the model predictions show that external auxin stimuli can lead to entrainment of the root clock. Our work demonstrates the mechanism underlying a robust biological clock and how it can respond to external stimuli.

14.
Plant J ; 53(5): 705-16, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18005227

RESUMO

In animals and fungi, a group of proteins called the cyclin-dependent kinase inhibitors play a key role in cell cycle regulation. However, comparatively little is known about the role of these proteins in plant cell cycle regulation. To gain insight into the mechanisms by which the plant cell cycle is regulated, we studied the cyclin-dependent kinase inhibitor KRP1 in Arabidopsis. KRP1 interacts with the CDKA;1/CYCD2;1 complex in planta and functions in the G1-S transition of the cell cycle. Furthermore, we show that KRP1 is a likely target of the ubiquitin/proteasome pathway. Two different ubiquitin protein ligases, SCF(SKP2) and the RING protein RKP, contribute to its degradation. These results suggest that SCF(SKP2b) and RPK play an important role in the cell cycle through regulating KRP1 protein turnover.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Proteínas Inibidoras de Quinase Dependente de Ciclina/metabolismo , Quinases Ciclina-Dependentes/antagonistas & inibidores , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/enzimologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Ciclo Celular/fisiologia , Proteínas Inibidoras de Quinase Dependente de Ciclina/genética , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos , Plantas Geneticamente Modificadas , Proteínas Quinases Associadas a Fase S/genética , Proteínas Quinases Associadas a Fase S/metabolismo
15.
FEBS Lett ; 593(2): 209-218, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30447065

RESUMO

Spermidine is a polyamine present in eukaryotes with essential functions in protein synthesis. At high concentrations spermidine and norspermidine inhibit growth by unknown mechanisms. Transcriptomic analysis of the effect of norspermidine on the plant Arabidopsis thaliana indicates upregulation of the response to heat stress and denatured proteins. Accordingly, these polyamines inhibit protein ubiquitylation, both in vivo (in yeast, Arabidopsis, and human Hela cells) and in vitro (with recombinant ubiquitin ligase). This interferes with protein degradation by the proteasome, a situation known to deplete cells of amino acids. Norspermidine treatment of yeast cells induces amino acid depletion, and supplementation of media with amino acids counteracts growth inhibition and cellular amino acid depletion but not inhibition of protein polyubiquitylation.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Perfilação da Expressão Gênica/métodos , Espermidina/análogos & derivados , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Células HeLa , Resposta ao Choque Térmico/efeitos dos fármacos , Humanos , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Análise de Sequência de RNA , Espermidina/farmacologia , Ubiquitinação
16.
Medisur ; 21(5)oct. 2023.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1521213

RESUMO

Fundamento la toxicidad asociada a los tratamientos de quimioterapia y radioterapia eleva la morbilidad y la mortalidad en los pacientes oncológicos. Objetivo diseñar un modelo predictivo de toxicidad de la quimioterapia y la radioterapia en el paciente oncológico quirúrgico. Métodos estudio analítico, de casos y controles, en pacientes oncológicos quirúrgicos que cumplieron los criterios de inclusión para la predicción de toxicidad preoperatoria, en el periodo enero a diciembre de 2022, en el Hospital Provincial Docente Oncológico María Curie, de Camagüey. Mediante el paquete estadístico Statistical Package for the Social Sciences, se seleccionó una muestra aleatoria de 334 pacientes, 197 sin toxicidad (grupo control) y 137 con toxicidad (grupo de estudio). Se realizó estimación de predictores de toxicidad mediante regresión logística binaria. Se seleccionó el modelo de mejor ajuste. Resultados el modelo en el paso tres predice un porcentaje global de 83,5 % con respecto a los valores observados. La sensibilidad resultó ser de 81,8; y la especificidad, 84,8. El modelo presentó buen poder discriminativo. Las variables en la ecuación fueron: hipertensión arterial, fracción de eyección del ventrículo izquierdo y anemia. La comparación de la predicción con la realidad, mediante curva Receiver Operating Characteristic determinó un área bajo la curva de 0,901. Conclusión se obtuvo una función de regresión logística que permitió la estimación de la probabilidad de toxicidad en pacientes oncológicos quirúrgicos electivos, la cual proporcionó una herramienta para su predicción desde el preoperatorio.


Foundation the toxicity associated with chemotherapy and radiotherapy treatments increases morbidity and mortality in cancer patients. Objective to design a predictive model of chemotherapy and radiotherapy toxicity in surgical cancer patients. Methods analytical, case-control study, in surgical oncology patients who met the inclusion criteria for the prediction of preoperative toxicity, from January to December 2022, at the María Curie Provincial Teaching Oncology Hospital in Camagüey. Using the Statistical Package for the Social Sciences, a random sample of 334 patients was selected, 197 without toxicity (control group) and 137 with toxicity (study group). Toxicity predictors were estimated using binary logistic regression. The model with the best fit was selected. Results the model in step three predicts an overall percentage of 83.5% with respect to the observed values. The sensitivity turned out to be 81.8; and the specificity, 84.8. The model presented good discriminative power. The variables in the equation were: arterial hypertension, left ventricular ejection fraction, and anemia. The comparison of the prediction with reality, using the Receiver Operating Characteristic curve, determined an area under the curve of 0.901. Conclusion a logistic regression function was obtained that allowed the estimation of the toxicity probability elective surgical cancer patients, which provided a tool for its prediction from the preoperative period.

17.
Rev Iberoam Micol ; 33(4): 187-195, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27067875

RESUMO

BACKGROUND: Although over the past decade the management of invasive fungal infection has improved, considerable controversy persists regarding antifungal prophylaxis in solid organ transplant recipients. AIMS: To identify the key clinical knowledge and make by consensus the high level recommendations required for antifungal prophylaxis in solid organ transplant recipients. METHODS: Spanish prospective questionnaire, which measures consensus through the Delphi technique, was conducted anonymously and by e-mail with 30 national multidisciplinary experts, specialists in invasive fungal infections from six national scientific societies, including intensivists, anesthetists, microbiologists, pharmacologists and specialists in infectious diseases that responded to 12 questions prepared by the coordination group, after an exhaustive review of the literature in the last few years. The level of agreement achieved among experts in each of the categories should be equal to or greater than 70% in order to make a clinical recommendation. In a second term, after extracting the recommendations of the selected topics, a face-to-face meeting was held with more than 60 specialists who were asked to validate the pre-selected recommendations and derived algorithm. MEASUREMENTS AND PRIMARY OUTCOMES: Echinocandin antifungal prophylaxis should be considered in liver transplant with major risk factors (retransplantation, renal failure requiring dialysis after transplantation, pretransplant liver failure, not early reoperation, or MELD>30); heart transplant with hemodialysis, and surgical re-exploration after transplantation; environmental colonization by Aspergillus, or cytomegalovirus (CMV) infection; and pancreas and intestinal transplant in case of acute graft rejection, hemodialysis, initial graft dysfunction, post-perfusion pancreatitis with anastomotic problems or need for laparotomy after transplantation. Antifungal fluconazole prophylaxis should be considered in liver transplant without major risk factors and MELD 20-30, split or living donor, choledochojejunostomy, increased transfusion requirements, renal failure without replacement therapy, early reoperation, or multifocal colonization or infection with Candida; intestinal and pancreas transplant with no risk factors for echinocandin treatment. Liposomal amphotericin B antifungal prophylaxis should be considered in lung transplant (inhalant form) and liver transplant with major risk factors. Antifungal prophylaxis with voriconazole should be considered in lung transplant, and heart transplant with hemodialysis, surgical re-exploration after transplantation, environmental colonization by Aspergillus, or CMV infection. CONCLUSIONS: The management of antifungal prophylaxis in solid organ transplant recipients requires the application of knowledge and skills that are detailed in our recommendations and the algorithm developed therein. These recommendations, based on the DELPHI methodology, may help to identify potential patients, standardize their management and improve overall prognosis.


Assuntos
Antifúngicos/uso terapêutico , Micoses/prevenção & controle , Transplante de Órgãos , Complicações Pós-Operatórias/microbiologia , Complicações Pós-Operatórias/prevenção & controle , Pré-Medicação , Algoritmos , Humanos , Estudos Prospectivos
18.
Foods ; 3(2): 279-289, 2014 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-28234319

RESUMO

Food allergies to hazelnut represent an important health problem in industrialized countries because of their high prevalence and severity. Food allergenicity can be changed by several processing procedures since food proteins may undergo modifications which could alter immunoreactivity. High-hydrostatic pressure (HHP) is an emerging processing technology used to develop novel and high-quality foods. The effect of HHP on allergenicity is currently being investigated through changes in protein structure. Our aim is to evaluate the effect of HHP on the protein profile of hazelnut immunoreactive extracts by comparative proteomic analysis with ProteomeLab PF-2D liquid chromatography and mass spectrometry. This protein fractionation method resolves proteins by isoelectric point and hydrophobicity in the first and second dimension, respectively. Second dimension chromatogram analyses show that some protein peaks present in unpressurized hazelnut must be unsolubilized and are not present in HHP-treated hazelnut extracts. Our results show that HHP treatment at low temperature induced marked changes on hazelnut water-soluble protein profile.

19.
Mol Plant ; 5(1): 260-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21914649

RESUMO

Recently, it has been shown that plants contain homologs to the animal Polycomb repressive complex 1 (PRC1) components BMI1 and RING1A/B. In Arabidopsis, there are three BMI1-like genes, two of which, AtBMI1A and B, are required during post-embryonic plant growth to repress embryonic traits and allow cell differentiation. However, little is known about the third BMI1-like gene, AtBMI1C. In this work, we show that AtBMI1C is only expressed during endosperm and stamen development. AtBMI1C is an imprinted gene expressed from the maternal allele in the endosperm but biallelically expressed in stamen. We found that the characteristic expression pattern of AtBMI1C is the result of a complex epigenetic regulation that involves CG DNA methylation, RNA-directed non-CG DNA methylation (RdDM), and PcG activity. Our results show the orchestrated interplay of different epigenetic mechanisms in regulating gene expression throughout development, shedding light on the current hypotheses for the origin and mechanism of imprinting in plant endosperm.


Assuntos
Arabidopsis/genética , Epigênese Genética , Regulação da Expressão Gênica de Plantas , Impressão Genômica , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Endosperma/genética , Endosperma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento
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