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Basement membrane, a specialized ECM that underlies polarized epithelium of eumetazoans, provides signaling cues that regulate cell behavior and function in tissue genesis and homeostasis. A collagen IV scaffold, a major component, is essential for tissues and dysfunctional in several diseases. Studies of bovine and Drosophila tissues reveal that the scaffold is stabilized by sulfilimine chemical bonds (S = N) that covalently cross-link methionine and hydroxylysine residues at the interface of adjoining triple helical protomers. Peroxidasin, a heme peroxidase embedded in the basement membrane, produces hypohalous acid intermediates that oxidize methionine, forming the sulfilimine cross-link. We explored whether the sulfilimine cross-link is a fundamental requirement in the genesis and evolution of epithelial tissues by determining its occurrence and evolutionary origin in Eumetazoa and its essentiality in zebrafish development; 31 species, spanning 11 major phyla, were investigated for the occurrence of the sulfilimine cross-link by electrophoresis, MS, and multiple sequence alignment of de novo transcriptome and available genomic data for collagen IV and peroxidasin. The results show that the cross-link is conserved throughout Eumetazoa and arose at the divergence of Porifera and Cnidaria over 500 Mya. Also, peroxidasin, the enzyme that forms the bond, is evolutionarily conserved throughout Metazoa. Morpholino knockdown of peroxidasin in zebrafish revealed that the cross-link is essential for organogenesis. Collectively, our findings establish that the triad-a collagen IV scaffold with sulfilimine cross-links, peroxidasin, and hypohalous acids-is a primordial innovation of the ECM essential for organogenesis and tissue evolution.
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Membrana Basal/metabolismo , Evolução Biológica , Iminas/química , Compostos de Enxofre/química , Sequência de Aminoácidos , Animais , Colágeno Tipo IV/química , Reagentes de Ligações Cruzadas/química , Drosophila melanogaster , Matriz Extracelular/metabolismo , Proteínas da Matriz Extracelular/química , Heme/química , Espectrometria de Massas , Dados de Sequência Molecular , Peptídeos/química , Peroxidase/química , Peroxidases/química , Estrutura Terciária de Proteína , Análise de Sequência de RNA , Homologia de Sequência de Aminoácidos , Peixe-Zebra , PeroxidasinaRESUMO
Chronic inflammation is known to play a critical role in the development of cancer. Recent evidence suggests that high salt in the tissue microenvironment induces chronic inflammatory milieu. In this report, using three breast cancer-related cell lines, we determined the molecular basis of the potential synergistic inflammatory effect of sodium chloride (NaCl) with interleukin-17 (IL-17). Combined treatment of high NaCl (0.15M) with sub-effective IL-17 (0.1 nM) induced enhanced growth in breast cancer cells along with activation of reactive nitrogen and oxygen (RNS/ROS) species known to promote cancer. Similar effect was not observed with equi-molar mannitol. This enhanced of ROS/RNS activity correlates with upregulation of γENaC an inflammatory sodium channel. The similar culture conditions have also induced expression of pro-inflammatory cytokines such as IL-6, TNFα etc. Taken together, these data suggest that high NaCl in the cellular microenvironment induces a γENaC mediated chronic inflammatory response with a potential pro-carcinogenic effect.
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Neoplasias da Mama/imunologia , Canais Epiteliais de Sódio/metabolismo , Inflamação , Interleucina-17/metabolismo , Cloreto de Sódio/farmacologia , Estresse Fisiológico/imunologia , Western Blotting , Neoplasias da Mama/fisiopatologia , Carcinógenos/farmacologia , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Canais Epiteliais de Sódio/genética , Feminino , Humanos , Estresse Fisiológico/genética , Regulação para Cima/efeitos dos fármacosRESUMO
OBJECTIVE: To determine to what extent did health care workers experience the pandemic as a severe stress event. METHODS: This cross-sectional evaluation of 8299 health care workers, representing a 22% response rate, utilized machine learning to predict high levels of escalating stress based on demographics and known predictors for adverse psychological outcomes after trauma. RESULTS: A third of health care workers experienced the pandemic as a potentially traumatic stress event; a greater proportion of health care workers experienced high levels of escalating stress. Predictive factors included sense of control, ability to manage work-life demands, guilt or shame, age, and level of education. Gender was no longer predictive after controlling for other factors. Escalating stress was especially high among nonclinical academics and clinical private practitioners. CONCLUSION: Findings suggest adverse effects on total worker health, care quality, professionalism, retention, and acute and chronic mental health.
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COVID-19 , Desastres , Transtornos de Estresse Pós-Traumáticos , Humanos , COVID-19/epidemiologia , Estudos Transversais , Autoavaliação (Psicologia) , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Pessoal de Saúde/psicologiaRESUMO
Cell based immunotherapy is rapidly emerging as a promising cancer treatment. A modest increase in salt (sodium chloride) concentration in immune cell cultures is known to induce inflammatory phenotypic differentiation. In our current study, we analyzed the ability of salt treatment to induce ex vivo expansion of tumor-primed CD4 (cluster of differentiation 4)+T cells to an effector phenotype. CD4+T cells were isolated using immunomagnetic beads from draining lymph nodes and spleens from tumor bearing C57Bl/6 mice, 28 days post-injection of Py230 syngeneic breast cancer cells. CD4+T cells from non-tumor bearing mice were isolated from splenocytes of 12-week-old C57Bl/6 mice. These CD4+T cells were expanded ex vivo with five stimulation cycles, and each cycle comprised of treatment with high salt (Δ0.035 M NaCl) or equimolar mannitol controls along with anti-CD3/CD28 monoclonal antibodies for the first 3 days, followed by the addition of interleukin (IL)-2/IL-7 cytokines and heat killed Py230 for 4 days. Ex vivo high salt treatment induced a two-fold higher Th1 (T helper type 1) expansion and four-fold higher Th17 expansion compared to equimolar mannitol treatment. Importantly, the high salt expanded CD4+T cells retained tumor-specificity, as demonstrated by higher in vitro cytotoxicity against Py230 breast cancer cells and reduced in vivo syngeneic tumor growth. Metabolic studies revealed that high salt treatment enhanced the glycolytic reserve and basal mitochondrial oxidation of CD4+T cells, suggesting a role of high salt in enhanced pro-growth anabolic metabolism needed for inflammatory differentiation. Mechanistic studies demonstrated that the high salt induced switch to the effector phenotype was mediated by tonicity-dependent transcription factor, TonEBP/NFAT5. Using a transgenic murine model, we demonstrated that CD4 specific TonEBP/NFAT5 knock out (CD4cre/creNFAT5flox/flox) abrogated the induction of the effector phenotype and anti-tumor efficiency of CD4+T cells following high salt treatment. Taken together, our data suggest that high salt-mediated ex vivo expansion of tumor-primed CD4+T cells could induce effective tumor specific anti-cancer responses, which may have a novel cell-based cancer immunotherapeutic application.
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The burden of the COVID-19 pandemic upon healthcare workers necessitates a systematic effort to support their resilience. This article describes the Yale University and Yale New Haven Health System effort to unite several independent initiatives into a coherent integrated model for institutional support for healthcare workers. Here, we highlight both opportunities and challenges faced in attempting to support healthcare workers during this pandemic.
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Centros Médicos Acadêmicos/organização & administração , Sintomas Comportamentais/terapia , COVID-19 , Atenção Plena/organização & administração , Estresse Ocupacional/terapia , Recursos Humanos em Hospital/psicologia , Intervenção Psicossocial/organização & administração , Resiliência Psicológica , Apoio Social , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The sodium-dependent, high affinity choline transporter - choline cotransporter - (ChCoT, aka: cho-1, CHT1, CHT) undergoes constitutive and regulated trafficking between the plasma membrane and cytoplasmic compartments. The pathways and regulatory mechanisms of this trafficking are not well understood. We report herein studies involving selective endosomal ablation to further our understanding of the trafficking of the ChCoT. Selective ablation of early sorting and recycling endosomes resulted in a decrease of approximately 75% of [3H]choline uptake and approximately 70% of [3H]hemicholinium-3 binding. Western blot analysis showed that ablation produced a similar decrease in ChCoTs in the plasma membrane subcellular fraction. The time frame for this loss was approximately 2 h which has been shown to be the constitutive cycling time for ChCoTs in this tissue. Ablation appears to be dependent on the intracellular cycling of transferrin-conjugated horseradish peroxidase and the selective deposition of transferrin-conjugated horseradish peroxidase in early endosomes, both sorting and recycling. Ablated brain slices retained their capacity to recruit via regulated trafficking ChCoTs to the plasma membrane. This recruitment of ChCoTs suggests that the recruitable compartment is distinct from the early endosomes. It will be necessary to do further studies to identify the novel sequestration compartment supportive of the ChCoT regulated trafficking.
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Colinérgicos/metabolismo , Endossomos/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Neurônios/fisiologia , Técnicas de Ablação/métodos , Animais , Membrana Celular/metabolismo , Colina/metabolismo , Endocitose , Feminino , Hemicolínio 3/metabolismo , Peroxidase do Rábano Silvestre/metabolismo , Caranguejos Ferradura , Masculino , Neurônios/citologia , Cloreto de Potássio/metabolismo , Ligação Proteica , Transporte Proteico/fisiologia , Frações Subcelulares/fisiologia , Fatores de Tempo , Trítio/metabolismoRESUMO
Previous phase I DNA-vaccine based clinical trials using Mammaglobin-A (Mam-A), a human breast tumor associated antigen (TAA), demonstrated that this agent was safe and efficient at treating patients with stage IV breast cancer. The long-term success of cancer vaccines is limited by the diminished expression of human leukocyte antigen (HLA) class I molecules in the tumor microenvironment. The current study assessed the impact of various selenocompounds on the expression of HLA class I molecules in THP-1 cells, an apparent proficient antigen that presents a human monocyte-like cell line, and their eventual activation of MamA2.1 (HLA-A2 immunodominant epitope of Mam-A) specific cytotoxic CD8+ T lymphocytes (CTLs). The results revealed that, following treatment with methylselenol producing compounds [methylselenic acid (MSA) and dimethylselenide (DMDSe)], the expression of HLA class-I was increased and components involved with the antigen presentation machinery of THP-1 cells were upregulated. Furthermore, CTLs activated by MamA2.1 peptide presenting THP-1 cells, pre-treated with MSA and DMDSe, demonstrated an enhanced cytotoxicity in HLA-A2+/Mam-A+ AU565 and UACC-812 breast cancer cell lines when compared with CTLs activated by THP-1 cells without drug treatment. However, no significant cytotoxicity was observed under similar conditions in HLA-A2+/Mam-A- MCF-7 and MDA-MB-231 breast cancer cell lines. The results indicated that treatment with methylselenol producing compounds retained antigen-dependent activation of CD8+ T cells. The data of the current study demonstrated that MSA and DMDSe potentiated effector cytotoxic responses following TAA specific activation of CTLs, indicating their future role as vaccine adjuvants in cancer immunotherapy.
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Recent evidence from our laboratory has demonstrated that high salt (Δ0.05 M NaCl) induced inflammatory response and cancer cell proliferation through salt inducible kinase-3 (SIK3) upregulation. As calcium influx is known to effect inflammatory response and drug resistance, we examined the impact of high salt on calcium influx in breast cancer cells. Treatment of MCF-7 and MDA-MB-231 cells with high salt induced an enhanced intracellular calcium intensity, which was significantly decreased by store operated calcium entry (SOCE) inhibitor co-treatment. Further, high salt induced P-glycoprotein (P-gp) mediated paclitaxel drug resistance in breast cancer cells. Murine tumor studies demonstrated that injection of MCF-7 cells cultured in high salt, exerted higher tumorigenicity compared to the basal cultured counterpart. Knock down of SIK3 by specific shRNA inhibited tumorigenicty, expression of SOCE regulators and P-gp activity, suggesting SIK3 is an upstream mediator of SOCE induced calcium influx. Furthermore, small molecule inhibitor, prostratin, exerted anti-tumor effect in murine models through SIK3 inhibition. Taken together, we conclude that SIK3 is an upstream regulator of store operated calcium entry proteins, Orai1 and STIM1, and mediates high salt induced inflammatory cytokine responses and P-gp mediated drug resistance. Therefore, small molecule inhibitors, such as prostratin, could offer novel anti-cancer approaches.
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OBJECTIVE: To quantify midlevel practitioner (MLP) staffing requirements based on the volume and complexity of patient care and the duty-hour constraints of the Accreditation Council for Graduate Medical Education 80-hour workweek. DESIGN: Data extracted from Eclipsys Sunrise Decision Support Manager, the hospital financial budget, and census reports; and MLP, resident, and subspecialty fellow clinical, operative, and on-call schedules, and educational curriculum. Fiscal year 2005 patient census and hours of required care were defined by attending physician service and/or patient care location. Volume of patient care activity for MLPs, residents, and subspecialty fellows were established by verified self-reporting methodology. SETTING: Urban teaching hospital with 867 beds, of which 116 are surgical beds (which include 36 intensive care unit beds and 12 step-down beds). PARTICIPANTS: Attending physicians, MLPs, residents, and subspecialty fellows. MAIN OUTCOME MEASURES: Coverage index (available staffing hours [residents, subspecialty fellows, and MLPs] divided by the clinical coverage schedule), and the workload staffing efficiency index (number of clinical hours of patient care activities divided by the hours of available staff for a specific clinical service). RESULTS: The workload staffing efficiency index and the coverage index identified 4 services that benefited from the addition of new MLPs. CONCLUSION: We developed a quantitative MLP staffing methodology based on patient volume and the type and complexity of direct and indirect patient care activities, encompassing the roles and availability of residents, subspecialty fellows, and MLPs.
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Benchmarking , Hospitais Universitários , Corpo Clínico Hospitalar/provisão & distribuição , Carga de Trabalho , Cirurgia Geral , Humanos , Estudos Retrospectivos , Estados Unidos , Recursos HumanosRESUMO
The ACGME mandates a competency-based resident education curriculum. The Joint Commission (TJC) requires a quality improvement (QI) program in all hospitals with residency training programs. Our QI program, based on M&M conference data, provided the operational framework for peer review and resolution of adverse events. However, the conference focused on only three of the six ACGME core competencies (patient care, medical knowledge, practice-based learning and improvement) but not specifically on interpersonal and communication skills, professionalism or systems-based practice. To address this issue, we devised a two-tiered QI process that meets the reporting mandate of TJC and addresses all six ACGME core competencies. Adverse events are reported and discussed in the Department of Surgery's divisional M&M conferences. If an issue involving the ACGME core competencies is identified that requires nonconference discussion, ie, communication, professionalism or systems-based practice, the case is referred to the Department of Surgery Subcommittee for Quality Improvement (SCQI). A report is then returned to the divisional M&M for discussion and possible incorporation into the Resident Core Curriculum. Resident and attending surgeon surveys demonstrated the new format to be effective in addressing all six ACGME competencies.
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Competência Clínica , Congressos como Assunto , Educação de Pós-Graduação em Medicina , Internato e Residência , Avaliação de Programas e Projetos de Saúde , Acreditação , Currículo , Humanos , Morbidade , Mortalidade , Qualidade da Assistência à SaúdeRESUMO
BACKGROUND: The pro-inflammatory cytokines, tumor necrosis factor (TNF)-α, and interleukin (IL)-17, have been implicated in the pathogenesis of liver fibrosis. In this study, we investigated the role of TNFα and IL-17 toward induction of profibrotic factor, periostin. METHODS: HepG2 cells were cultured and treated with inflammatory cytokines, TNFα and IL-17. Computational promoter sequence analysis of the periostin promoter was performed to define the putative binding sites for transcription factors. Transcription factors were analyzed by Western blot and Chromatin Immunoprecipitation. Periostin and transcription factor expression analysis was performed by RT-PCR, Western blot, and fluorescence microscopy. Type I collagen expression from fibroblast cultures was analyzed by Western blot and Sircol soluble collagen assay. RESULTS: Activation of HepG2 Cells with TNFα and IL-17 enhanced the expression of periostin (3.5 and 4.4 fold, respectively p<0.05) compared to untreated cells. However, combined treatment with both TNFα and IL-17 at similar concentration demonstrated a 13.3 fold increase in periostin (p<0.01), thus suggesting a synergistic role of these cytokines. Periostin promoter analysis and specific siRNA knock-down revealed that TNFα induces periostin through cJun, while IL-17 induced periostin via STAT-3 signaling mechanisms. Treatment of the supernatant from the cytokine activated HepG2 cells on fibroblast cultures induced enhanced expression of type I collagen (>9.1 fold, p<0.01), indicative of a direct fibrogenic effect of TNFα and IL-17. CONCLUSION: TNFα and IL-17 induced fibrogenesis through cJun and STAT-3 mediated expression of profibrotic biomarker, periostin. Therefore, periostin might serve as a novel biomarker in early diagnosis of liver fibrosis.
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Moléculas de Adesão Celular/metabolismo , Colágeno Tipo I/metabolismo , Mediadores da Inflamação/farmacologia , Interleucina-17/farmacologia , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Fator de Necrose Tumoral alfa/farmacologia , Moléculas de Adesão Celular/genética , Colágeno Tipo I/genética , DNA de Neoplasias/metabolismo , Fibroblastos/metabolismo , Células Hep G2 , Humanos , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteínas Proto-Oncogênicas c-jun/metabolismo , Fator de Transcrição STAT3/metabolismo , Transcrição GênicaRESUMO
We describe herein the cloning of a group of syntaxins in Limulus that are associated with the plasma membrane. Initially, multiple degenerate oligonucleotide primers (DOP) and probes were designed from sequences of known plasma membrane associated syntaxins. Combined experiments using reverse transcriptase-polymerase chain reaction (RT-PCR), colony hybridization and reverse dot blot yielded three distinct probes. Subsequently, two cDNA libraries derived from the Limulus central nervous system (CNS) were screened and four distinct isoforms, designated Limulus syntaxin (Lim-syn) 1A, 1B, 1C and 1D, were obtained from forty cloned full-length sequences. The predicted amino acid (aa) sequences 1-265 were identical for Lim-syn 1A, 1C and for Lim-syn 1B, 1D, respectively. A comparison of the 265 aa cytoplasmic segments for the two subgroups Lim-syn 1A/1C and Lim-syn 1B/1D differed at 13 aa residues within this sequence. Lim-syn 1A and 1B contained 290 aa residues, and both contained a transmembrane domain (TMD, 267-288) and a myristylation-like site (286-290) at the C-termini. Lim-syn 1C (291 residues) contained only the TMD whereas Lim-syn 1D was truncated (277 residues) and had neither a TMD nor a myristylation-like site. All Lim-syn isoforms showed great identity with syntaxin 1-homologs (syntaxin 1A/1B) from various other species. Ribonuclease protection assay (RPA) analyses revealed distinctive expression patterns for individual Lim-syn transcripts but all were detectable in the CNS. Moreover, the antibody (anti-Lim-syn-1) produced against aa 133-145 epitope of Lim-syn identified a protein of approximately 35 kDa found only in CNS tissues.
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Membrana Celular/metabolismo , Caranguejos Ferradura/genética , Proteínas de Membrana/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Clonagem Molecular , DNA Complementar/química , DNA Complementar/genética , Expressão Gênica , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Isoformas de Proteínas/genética , Proteínas Qa-SNARE , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de AminoácidosRESUMO
The authors describe their reactions, as surgical educators, to the mandate of the Accreditation Council for Graduate Medical Education to reduce resident work hours. They explain these reactions in terms of Dr. Elizabeth Kübler-Ross's five stages of grief: denial, anger, bargaining, depression, and finally acceptance ("which should not be mistaken for a happy stage"). The authors describe each stage of grief and use it to make specific comments on the difficulties that the mandate imposes. They then reveal that their views about the work-hours regulations differ: Dr. Ivy now sees them as an opportunity to grow and improve, and likens the resistance to the new restrictions to that of Europeans to the printing press. But Dr. Barone ("the older of the coauthors and a known curmudgeon") is not so sure, and shares many of the concerns described earlier in the five stages of grief, even though he has outwardly accepted the work-hours rules and insists on full compliance by his residents and faculty. In particular, he is saddened that some residents feel they have the absolute right to go home regardless of the situation on the surgery service, and this feeling is validated by the work-hours rules.
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Atitude do Pessoal de Saúde , Internato e Residência/organização & administração , Admissão e Escalonamento de Pessoal/organização & administração , Tolerância ao Trabalho Programado/psicologia , Carga de Trabalho/psicologia , Cirurgia Geral/educação , Humanos , Valores Sociais , Estados UnidosRESUMO
PURPOSE: To define the extent and nature of the End-of-Life (EOL) decision-making process in critically ill patients. MATERIALS AND METHODS: Retrospective review of all deaths in adult medical and surgical intensive care units of a tertiary care hospital over a one-year period. RESULTS: There were sixty-one deaths in the study period. The mean age was 68 years, and 30 patients (49%) were female. Nearly one-third of patients had advance directives: eight patients presented advance directives on hospital admission, and 10 families produced advance directives at EOL. Seventy-six percent were admitted to the ICU as Code I (full care) and 24% were Code II (selective modification of care). At EOL, 10 patients were Code I, 14 were Code II, and 38 were transitioned to Code III (comfort care only). In the Code III population, the change in code status was initiated by the family in 12 cases. CONCLUSIONS: In a substantial number of instances transitioned to comfort care at EOL, the family initiated the code-status change. Interestingly, in several cases the family initially withheld advance directives. Critically ill patients and their families are assuming an active role in EOL care.
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Cuidados Críticos , Assistência Terminal , Idoso , Tomada de Decisões , Família , Feminino , Humanos , Masculino , Planejamento de Assistência ao Paciente , Estudos RetrospectivosRESUMO
The identities of genes that underlie population variation in adipose tissue development in farm animals are poorly understood. Previous studies in our laboratory have suggested that increased fat tissue involves the expression modulation of an array of genes in broiler chickens. Of special interest are eight genes, FGFR3, EPHB2, IGFBP2, GREM1, TNC, COL3A1, ACBD7, and SCD. To understand their expression regulation and response to dietary manipulation, we investigated their mRNA levels after dietary manipulation during early development. Chickens were fed either a recommended standard or a high caloric diet from hatch to eight weeks of age (WOA). The high caloric diet markedly affected bodyweight of the broiler birds. mRNA levels of the eight genes in the abdominal adipose tissue were assayed at 2, 4, 6, and 8 WOA using RT-qPCR. Results indicate that (1) FGFR3 mRNA level was affected significantly by diet, age, and diet:age interaction; (2) COL3A mRNA level was repressed by high caloric diet; (3) mRNA levels of EPHB2, ACBD7, and SCD were affected by age; (4) mRNA level of TNC was modulated by age:diet interaction; (5) changes in GREM1 and IGFBP2 mRNA levels were not statistically different.
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OBJECTIVE: To explore why it is permissible for surgeons to "unilaterally withhold" surgery, whereas it is not commonplace (in the United States) to unilaterally withhold cardiopulmonary resuscitation (CPR) for clinical situations with similar degrees of uncertainty and prognosis. DATA SOURCES: The medical literature was sampled using PubMed and Google search engines, employing a variety of search strategies to capture articles relating to medical/surgical decision-making, risk aversion, acute care surgery, and withholding life-saving therapies. These topics are used to highlight interprovider variability that affects all practitioners-not just surgeons-and to consider why we deem it permissible for surgeons to withhold surgery, whereas-in the United States, at least-it is not routinely permissible for clinicians to unilaterally withhold mechanical ventilation and CPR for cases with similar prognoses. CONCLUSIONS: While there are no published research studies that deal directly with this topic, knowledge, heuristics, experience, variable aversion to risk, and other features inherent in medical-surgical education likely impact decisions to offer or withhold potentially life-saving therapies of all kinds. Both surgeons and clinicians, who request surgical consultation for hospitalized patients, should consider these issues and politely pursue second opinions when there is any doubt whether forgoing surgery is in the patient's best interests. Similarly, while unilateral withholding of CPR is not commonly employed in some medical cultures, including the United States, beneficence can be facilitated through robust informed consent.
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Tomada de Decisões , Cirurgia Geral , Médicos , Suspensão de Tratamento , Adulto , Reanimação Cardiopulmonar , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Current therapies to enhance CNS cholinergic function rely primarily on extracellular acetylcholinesterase (AChE) inhibition, a pharmacotherapeutic strategy that produces dose-limiting side effects. The Na(+)-dependent, high-affinity choline transporter (CHT) is an unexplored target for cholinergic medication development. Although functional at the plasma membrane, CHT at steady-state is localized to synaptic vesicles such that vesicular fusion can support a biosynthetic response to neuronal excitation. To identify allosteric potentiators of CHT activity, we mapped endocytic sequences in the C-terminus of human CHT, identifying transporter mutants that exhibit significantly increased transport function. A stable HEK-293 cell line was generated from one of these mutants (CHT LV-AA) and used to establish a high-throughput screen (HTS) compatible assay based on the electrogenic nature of the transporter. We established that the addition of choline to these cells, at concentrations appropriate for high-affinity choline transport at presynaptic terminals, generates a hemicholinium-3 (HC-3)-sensitive, membrane depolarization that can be used for the screening of CHT inhibitors and activators. Using this assay, we discovered that staurosporine increased CHT LV-AA choline uptake activity, an effect mediated by a decrease in choline K(M) with no change in V(max). As staurosporine did not change surface levels of CHT, nor inhibit HC-3 binding, we propose that its action is directly or indirectly allosteric in nature. Surprisingly, staurosporine reduced choline-induced membrane depolarization, suggesting that increased substrate coupling to ion gradients, arising at the expense of nonstoichiometric ion flow, accompanies a shift of CHT to a higher-affinity state. Our findings provide a new approach for the identification of CHT modulators that is compatible with high-throughput screening approaches and presents a novel model by which small molecules can enhance substrate flux through enhanced gradient coupling.
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Colina/metabolismo , Ensaios de Triagem em Larga Escala/métodos , Proteínas de Membrana Transportadoras/metabolismo , Terminações Pré-Sinápticas/metabolismo , Regulação Alostérica/fisiologia , Animais , Células COS , Chlorocebus aethiops , Feminino , Células HEK293 , Humanos , Transporte Proteico/fisiologia , Xenopus laevisRESUMO
HYPOTHESIS: The acute care surgery (ACS) 2-year training model, incorporating surgical critical care (SCC), trauma surgery, and emergency general surgery, was developed to improve resident interest in the field. We believed that analysis of survey responses about the new training paradigm before its implementation would yield valuable information on current practice patterns and on opinions about the ACS model. DESIGN: Two surveys. PARTICIPANTS: Members of the Surgery Section of the Society of Critical Care Medicine and SCC program directors. INTERVENTIONS: One survey was sent to SCC program directors to define the practice patterns of trauma and SCC surgeons at their institutions, and another survey was sent to all Surgery Section of the Society of Critical Care Medicine members to solicit opinions about the ACS model. MAIN OUTCOME MEASURES: Practice patterns of trauma and SCC surgeons and opinions about the ACS model. RESULTS: Fifty-seven of 87 SCC program directors responded. Almost all programs are associated with level I trauma centers with as many as 15 trauma surgeons. Most of these trauma surgeons cover SCC and emergency general surgery. Sixty-six percent of surgical intensive care units are semiclosed; 89.0% have surgeons as directors. Seventy percent of the staff in surgical intensive care units are surgeons. One hundred fifty-five of approximately 1100 Surgery Section of the Society of Critical Care Medicine members who responded to the other survey did not believe that the ACS model would compromise surgical intensive care unit and trauma care or trainee education yet would allow surgeons to maintain their surgical skills. Respondents were less likely to believe that the ACS fellowship would be important financially, increase resident interest, or improve patient care. CONCLUSIONS: In academic medical centers, surgical intensivists already practice the ACS model but depend on many nonsurgeons. Surgical intensivists believe that ACS will not compromise care or education and will help maintain the field, although the effect on resident interest is unclear.
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Cuidados Críticos , Cirurgia Geral/educação , Internato e Residência , Traumatologia/educação , Escolha da Profissão , Coleta de Dados , HumanosRESUMO
INTRODUCTION: Groups of evidence-based guidelines were developed into a comprehensive treatment bundle as part of an international-based Surviving Sepsis Campaign to improve treatment of severe sepsis and septic shock. Conventional educational strategies of this sepsis treatment "bundle" may not ensure acceptable knowledge or completion of these specific tasks and may overlook other dynamic factors present during critical moments of a crisis. Simulation using multidisciplinary teams of clinicians through mannequin-based simulations (MDMS) may improve "bundle" compliance by identifying sepsis guideline errors, reinforcing knowledge, and exposing other potential causes of poor performance. METHODS: Seventy-four clinicians participated in the MDMS 14 months after hospital-wide introduction of the sepsis bundle. Additionally, each team was given a sepsis treatment-learning packet before the training session. Twelve teams underwent a MDMS of a patient in septic shock. Two evaluators recorded completed sepsis guideline tasks in real time. Sessions were videotaped and reviewed with the team in a postscenario debriefing session. Pre/posttests were also administered. RESULTS: Individual participants' pretest scores averaged 64.6% correct. Despite all but one team having at least one knowledgeable member with a pretest score of at least 80%, team task completion averaged only 60.4%. Team mean pretest scores and proportion of tasks completed were significantly correlated (P = 0.007), but correlations between specific tasks and related questions showed no relationship to knowledge. CONCLUSION: Inadequate completion of the sepsis guideline tasks during the MDMS could not be explained by inadequate pretest knowledge alone. MDMS may be a useful tool in identifying and exploring these unknown factors.