RESUMO
MECOM rearrangements are recurrent in myeloid neoplasms and associated with poor prognosis. However, only inv(3)(q21q26.2) and t(3;3)(q21;q26.2), the classic MECOM rearrangements resulting in RPN1-MECOM rearrangement with Mecom overexpression and GATA2 haploinsufficiency, define the distinct subtype of acute myeloid leukemia (AML), and serve as presumptive evidence for myelodysplastic syndrome based on the current World Health Organization classification. Myeloid neoplasms with nonclassic 3q26.2/MECOM rearrangements have been found to be clinically aggressive, but comparative analysis of clinicopathologic and genomic features is limited. We retrospectively studied cohorts of myeloid neoplasms with classic and nonclassic MECOM rearrangements. Cases with classic rearrangements consisted predominantly of AML, often with inv(3) or t(3;3) as the sole chromosome abnormality, whereas the group of nonclassic rearrangements included a variety of myeloid neoplasms, often with complex karyotype without TP53 mutations and similarly dismal overall survival. Immunohistochemistry revealed Mecom protein overexpression in both groups, but overexpression in cases with nonclassic rearrangements was mediated through a mechanism other than GATA2 distal enhancer involvement typical for classic rearrangement. Our results demonstrated that myeloid neoplasms with nonclassic 3q26.2/MECOM rearrangements encompass a diverse group of diseases with poor clinical outcome, overexpression of Mecom protein as a result of the nonclassic mechanism of MECOM activation.
Assuntos
Rearranjo Gênico/genética , Leucemia Mieloide , Proteína do Locus do Complexo MDS1 e EVI1 , Adulto , Idoso , Análise Citogenética , Feminino , Genômica , Humanos , Leucemia Mieloide/diagnóstico , Leucemia Mieloide/genética , Leucemia Mieloide/patologia , Proteína do Locus do Complexo MDS1 e EVI1/genética , Proteína do Locus do Complexo MDS1 e EVI1/metabolismo , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Estudos Retrospectivos , Adulto JovemRESUMO
Focal adhesion kinase (FAK) plays a key role in integrin and growth factor signaling pathways. FAK-related non-kinase (FRNK) is an endogenous inhibitor of FAK that shares its primary structure with the C-terminal third of FAK. FAK S910 phosphorylation is known to regulate FAK protein-protein interactions, but the role of the equivalent site on FRNK (S217) is unknown. Here we determined that S217 is highly phosphorylated by ERK in cultured rat aortic smooth muscle cells. Blocking phosphorylation by mutation (S217A) greatly increased FRNK inhibitory potency, resulting in strong inhibition of FAK autophosphorylation at Y397 and induction of smooth muscle cell apoptosis. FRNK has been proposed to compete for FAK anchoring sites in focal adhesions, but we did not detect displacement of FAK by WT-FRNK or superinhibitory S217A-FRNK. Instead, we found FRNK interacted directly with FAK, and this interaction is markedly strengthened for the superinhibitory S217A-FRNK. The results suggest that FRNK limits growth and survival signaling pathways by binding directly to FAK in an inhibitory complex, and this inhibition is relieved by phosphorylation of FRNK at S217.
Assuntos
Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Miócitos de Músculo Liso/enzimologia , Inibidores de Proteínas Quinases/metabolismo , Animais , Quinase 1 de Adesão Focal , Músculo Liso Vascular/citologia , Fosforilação , Ratos , Transdução de Sinais/fisiologiaRESUMO
The cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA) establishes the intracellular calcium gradient across the sarcoplasmic reticulum membrane. It has been proposed that SERCA forms homooligomers that increase the catalytic rate of calcium transport. We investigated SERCA dimerization in rabbit left ventricular myocytes using a photoactivatable cross-linker. Western blotting of cross-linked SERCA revealed higher-molecular-weight species consistent with SERCA oligomerization. Fluorescence resonance energy transfer measurements in cells transiently transfected with fluorescently labeled SERCA2a revealed that SERCA readily forms homodimers. These dimers formed in the absence or presence of the SERCA regulatory partner, phospholamban (PLB) and were unaltered by PLB phosphorylation or changes in calcium or ATP. Fluorescence lifetime data are compatible with a model in which PLB interacts with a SERCA homodimer in a stoichiometry of 1:2. Together, these results suggest that SERCA forms constitutive homodimers in live cells and that dimer formation is not modulated by SERCA conformational poise, PLB binding, or PLB phosphorylation.
Assuntos
ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/química , Trifosfato de Adenosina/química , Trifosfato de Adenosina/metabolismo , Animais , Western Blotting , Cálcio/química , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Cães , Transferência Ressonante de Energia de Fluorescência , Células HEK293 , Ventrículos do Coração/química , Ventrículos do Coração/enzimologia , Humanos , Imunoprecipitação , Proteínas Luminescentes/química , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Modelos Moleculares , Células Musculares/química , Células Musculares/enzimologia , Mutação , Fosforilação , Fotodegradação , Multimerização Proteica , Coelhos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismoRESUMO
Recent updates in the classification of myeloid neoplasms (MNs) recognize the poor prognostic impact of TP53 mutations, with particular emphasis on the TP53 allele status. Studies on the effect of TP53 allele status exclusively in therapy-related MNs (t-MNs) are lacking. We compared the clinicopathologic and survival characteristics of t-MNs with single-hit (SH) and multi-hit (MH) TP53 mutations. A total of 71 TP53-mutated t-MNs were included, including 56 (78.9%) MH and 15 (21.1%) SH. Both groups showed comparable genetic profiles with an excess of high-risk karyotypes and a paucity of other co-mutated genes. TP53 was the sole detectable mutation in 73.3% of SH and 75.0% of MH cases. The overall survival (OS) of SH TP53-mutated t-MNs was not significantly different from MH cases (median survival: 233 vs.273 days, p = 0.70). Our findings suggest that t-MNs with SH TP53 mutations share the poor prognostic and biologic profile of their MH counterparts.
RESUMO
The MYC protooncogene plays a critical role in many cellular processes. MYC translocations are recurrent in large B-cell lymphomas (LBCLs) where they exhibit a negative effect on survival. Gain of MYC copies is also frequently identified; however, there is no consensus on the frequency and prognostic significance of MYC copy gains. We collected FISH data for MYC with reflex testing for BCL2 and BCL6 and IHC results at diagnosis for a cohort of 396 de novo and transformed LBCL cases and compared progression-free (PFS) and overall survival (OS) to determine the prognostic impact of extra MYC copies. The prevalence of cases with MYC copy number gain was 20.9%. PFS was shorter for patients with ≥5 MYC copies compared to controls (p = 0.0005, HR = 2.25). .MYC gain trended towards worse OS; patients with ≥7MYC copies had worse OS (p = 0.013), similar to patients with MYC translocations. We propose that MYC gain represents a dose-dependent prognostic factor for LBCLs.
Assuntos
Variações do Número de Cópias de DNA , Linfoma Difuso de Grandes Células B , Humanos , Prognóstico , Hibridização in Situ Fluorescente , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/patologia , Translocação Genética , Proteínas Proto-Oncogênicas c-bcl-6/genéticaRESUMO
¼ Overall evidence for the treatment of an anterior cruciate ligament (ACL) injury in a pediatric or skeletally immature patient remains lows.¼ An ACL reconstruction is recommended with concomitant repairable chondral and meniscus injury or with symptoms of persistent instability despite high-quality rehabilitation.¼ Treatment decision for pediatric ACL reconstruction should use a shared decision-making model weighing the risks and benefits of both a nonoperative vs. surgical treatment.
Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Traumatismos do Joelho , Lesões do Menisco Tibial , Humanos , Criança , Lesões do Ligamento Cruzado Anterior/cirurgia , Lesões do Ligamento Cruzado Anterior/complicações , Traumatismos do Joelho/cirurgia , Traumatismos do Joelho/diagnóstico , Lesões do Menisco Tibial/cirurgiaRESUMO
OBJECTIVE: To quantify soft tissue perfusion changes in pilon fractures during staged treatment using laser-assisted indocyanine green angiography (LA-ICGA). SETTING: Level 1 trauma center. DESIGN: Prospective cohort study. PATIENTS/PARTICIPANTS: Twelve patients with 12 pilon fractures participated in the study. Seven patients had OTA/AO classification of 43-C3, 3 had 43-C2, and 2 had 43-B2. MAIN OUTCOME MEASURES: LA-ICGA was performed with the SPY fluorescence imaging platform. Analysis via ImageJ was used to generate a fractional area of perfusion (FAP) based on fluorescent intensity to objectively quantify soft tissue perfusion. Anterior, medial, and lateral measurements were performed at the time of initial external fixation (EF) application and then at the time of definitive fixation. RESULTS: FAP within the region of interest was on average 64% medially, 61% laterally, and 62% anteriorly immediately before EF placement. Immediately before definitive open reduction internal fixation, fractional region of interest perfusion was on average 86% medially, 87% laterally, and 86% anteriorly. FAP increased on average 24% medially ( P = 0.0004), 26% laterally ( P = 0.001), and 19% anteriorly ( P = 0.002) from the time of initial EF to the time of definitive open reduction and internal fixation. CONCLUSIONS: Quantitative improvement in soft tissue perfusion was identified through the course of staged surgical management in pilon fractures. LA-ICGA potentially may be used to determine appropriate timing for definitive surgical intervention based on the readiness of the soft tissue envelope. Ultimately, these findings may influence clinical outcomes with respect to choice of surgical approach, soft tissue management, surgical timing, and wound healing. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Assuntos
Fraturas do Tornozelo , Fraturas da Tíbia , Angiografia , Fraturas do Tornozelo/cirurgia , Fixação Interna de Fraturas/métodos , Humanos , Verde de Indocianina , Lasers , Perfusão , Projetos Piloto , Estudos Prospectivos , Estudos Retrospectivos , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/cirurgia , Resultado do TratamentoRESUMO
Intrachromosomal amplification of chromosome 21 (iAMP21) defines a rare provisional entity of B-cell acute lymphoblastic leukemia (B-ALL) in the current WHO classification and has been described as specific for pediatric patients with a median age at diagnosis of 9-10 years. We report two adult cases of B-ALL with iAMP21, one 31-year-old woman and one 40-year-old man, identified by karyotyping and next generation sequencing (NGS), with fluorescence in situ hybridization (FISH) pattern meeting diagnostic criteria for iAMP21. Both patients were treated on high-risk chemotherapeutic regimen followed by stem cell transplant. In contrast to reported high relapse rate within the first three years in pediatric population, our adult patients are alive in remission, with the interval from diagnosis to last follow up of 2.95 and 3.96 years. Our cases illustrate the importance of screening for iAMP21 in adult population when ETV6-RUNX1 FISH testing is not routinely performed for adult patients.
Assuntos
Leucemia de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Criança , Humanos , Hibridização in Situ Fluorescente , Cromossomos Humanos Par 21/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Aberrações CromossômicasRESUMO
The COVID-19 pandemic created new challenges in health care, and pathology departments have led with innovations in testing and education. While the medical community and public showed great interest in gross and histologic findings in COVID-affected patients, paradoxically many autopsy services nationwide closed due to uncertainties surrounding the proximity to infected patient tissue, shortages in personal protective equipment, and pressures to discontinue perceived nonessential hospital operations. These disruptions furthermore negatively impacted pathology trainee education. The autopsy division at Northwestern Memorial Hospital, with the belief that a fully functioning autopsy service is especially crucial at this time, adopted a framework for continuing at full capacity for both clinical care and education. New operations were modeled on national protocols by the Centers for Disease Control and Prevention and the College of American Pathologists, and the service continually adjusted policies to reflect rapidly changing guidelines and feedback from trainees and staff. Between January and December 2020, we performed 182 adult autopsies including 45 COVID-19 autopsies. Twelve residents, 4 staff, and 5 attendings rotated through the service. In exit interviews, participants expressed: (1) improved comfort managing both COVID-related and general autopsies; (2) sense of personal safety on service (despite the increased risk of exposure); (3) belief that both COVID-related and general autopsies contributed to their personal education and to the medical community. There have been zero known autopsy-related COVID-19 infections to date. We hope that our innovative autopsy service restructuring can serve as a framework for other academic programs during the current and in future pandemics.
RESUMO
CONTEXT.: This study represents the largest compilation to date of clinical and postmortem data from decedents with coronavirus disease 2019 (COVID-19). It will augment previously published small series of autopsy case reports, refine clinicopathologic considerations, and improve the accuracy of future vital statistical reporting. OBJECTIVE.: To accurately reflect the preexisting diseases and pathologic conditions of decedents with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection through autopsy. DESIGN.: Comprehensive data from 135 autopsy evaluations of COVID-19-positive decedents is presented, including histologic assessment. Postmortem examinations were performed by 36 pathologists at 19 medical centers or forensic institutions in the United States and Brazil. Data from each autopsy were collected through the online submission of multiple-choice and open-ended survey responses. RESULTS.: Patients dying of or with COVID-19 had an average of 8.89 pathologic conditions documented at autopsy, spanning a combination of prior chronic disease and acute conditions acquired during hospitalization. Virtually all decedents were cited as having more than 1 preexisting condition, encompassing an average of 2.88 such diseases each. Clinical conditions during terminal hospitalization were cited 395 times for the 135 autopsied decedents and predominantly encompassed acute failure of multiple organ systems and/or impaired coagulation. Myocarditis was rarely cited. CONCLUSIONS.: Cause-of-death statements in both autopsy reports and death certificates may not encompass the severity or spectrum of comorbid conditions in those dying of or with COVID-19. If supported by additional research, this finding may have implications for public health decisions and reporting moving forward through the pandemic.
Assuntos
COVID-19/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Autopsia , Brasil/epidemiologia , COVID-19/diagnóstico , COVID-19/epidemiologia , Causas de Morte , Doença Crônica , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Inquéritos e Questionários , Estados Unidos/epidemiologiaRESUMO
The recently-discovered single-span transmembrane proteins endoregulin (ELN), dwarf open reading frame (DWORF), myoregulin (MLN), and another-regulin (ALN) are reported to bind to the SERCA calcium pump in a manner similar to that of known regulators of SERCA activity, phospholamban (PLB) and sarcolipin (SLN). To determine how micropeptide assembly into oligomers affects the availability of the micropeptide to bind to SERCA in a regulatory complex, we used co-immunoprecipitation and fluorescence resonance energy transfer (FRET) to quantify micropeptide oligomerization and SERCA-binding. Micropeptides formed avid homo-oligomers with high-order stoichiometry (nâ¯>â¯2 protomers per homo-oligomer), but it was the monomeric form of all micropeptides that interacted with SERCA. In view of these two alternative binding interactions, we evaluated the possibility that oligomerization occurs at the expense of SERCA-binding. However, even the most avidly oligomeric micropeptide species still showed robust FRET with SERCA, and there was a surprising positive correlation between oligomerization affinity and SERCA-binding. This comparison of micropeptide family members suggests that the same structural determinants that support oligomerization are also important for binding to SERCA. Moreover, the unique oligomerization/SERCA-binding profile of DWORF is in harmony with its distinct role as a PLB-competing SERCA activator, in contrast to the inhibitory function of the other SERCA-binding micropeptides.
Assuntos
Peptídeos/química , Peptídeos/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/química , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Sinalização do Cálcio/genética , Sinalização do Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular , Transferência Ressonante de Energia de Fluorescência , Humanos , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Fases de Leitura Aberta/genética , Ligação Proteica , Multimerização Proteica/genética , Multimerização Proteica/fisiologia , Proteolipídeos/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genéticaRESUMO
With unprecedented expansion of the roles of women in the military and the longest period of continuous active combat in US history, it is time that research expanded, including the nutritional and hydration requirements of the female tactical athlete. Dehydration has a negative effect on athletic performance, most significantly in high intensity, aerobic endurance activities. There is evidence female athletes may be more prone to the potentially lethal effects of over hydration. The purpose of this article is to provide a review of the literature to ascertain optimal hydration strategies for the female tactical athlete.