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OBJECTIVE: Different studies identify mental health literacy as a protective factor for developing a mental health problem. The aim of this paper was to determine the degree of mental health literacy of the adolescent population of Barcelona, and its relationship with socio-demographic and educational variables. METHODS: A cross-sectional study was carried out in Barcelona during the 2017-2018 academic year. A total of 1,032 young people between thirteen and seventeen years of age participated. The following variables were collected: sex, age, nationality, socioeconomic status (RDHpc) and average school grade. The aim was to determine the degree of mental health literacy (knowledge, stigma and help-seeking) of the adolescent population of Barcelona, and its relationship with socio-demographic and educational variables. Multiple linear regression analysis was performed adjusting for the effect of sociodemographic variables on the score of each scale. RESULTS: The mean score (standard deviation) of the EMHL test was 7.28 (1.27) and 4.24 (1.14) respectively, with higher scores obtained by girls, high RDHpc, excellent score and Spanish nationality. The greatest difference in EMHL scores, adjusting for the rest of the variables, corresponded to adolescents with an excellent mean score and a high RDHpc index (with respect to the baseline category, beta=0.72 and 0.52 respectively). The mean stigma score was 27.6 (4.47) for CAMI and 8.83 (3.36) for RIBS. The variables related to a greater difference in score with respect to the baseline category and adjusted for the rest of the variables were: gender (boy=1.54) and academic grade (excellent=-2.38) for CAMI, and nationality (foreign=0.82) and academic grade (excellent=-1.30) for RIBS. The mean RIBS score was 8.83 (3.36) with the largest difference in score from baseline being foreign nationality (beta=0.82) and having a grade of excellent (1.30). Help-seeking was higher in parents and friends, with differences according to gender and nationality. CONCLUSIONS: The level of mental health literacy is medium-low. While gender, nationality and educational attainment are the factors that are related to knowledge and stigma, socio-economic status is only related to mental health literacy.
OBJECTIVE: Diferentes estudios identifican la alfabetización en salud y/o salud mental (ASM) como factores protectores contra el desarrollo de un problema de salud mental. El objetivo de este trabajo fue determinar el grado de alfabetización en salud mental de la población adolescente de Barcelona, así como su relación con variables sociodemográficas y educativas. METHODS: Se realizó un estudio transversal en Barcelona durante el curso 2017-2018. Participaron 1.032 jóvenes entre trece y diecisiete años. Se recogieron las siguientes variables: sexo; edad; nacionalidad; nivel socioeconómico (RDHpc); y nota media escolar. La ASM se midió mediante los test de conocimientos EMHL (reconocimiento de problemas mentales y conocimientos en salud mental; rango 0-10 cada parte), estigma (CAMI: rango 10-50, y RIBS: rango 4-20) y búsqueda de ayuda (GHSQ: rango de 1 a 7). Se realizó análisis de regresión lineal múltiple ajustando el efecto de variables sociodemográficas sobre la puntuación de cada escala. RESULTS: La puntuación media (desviación típica) del EMHL test fue de 7,28 (1,27) y 4,24 (1,14), respectivamente, obteniendo mayor puntuación las chicas, RDHpc altas, nota excelente y con nacionalidad española. La mayor diferencia de puntuación en EMHL, ajustando por el resto de variables, correspondió a los adolescentes con nota media excelente y con índice RDHpc elevado (respecto a la categoría basal, beta=0,72 y 0,52, respectivamente). La puntuación media del estigma fue 27,6 (4,47) para CAMI y 8,83 (3,36) para RIBS. Las variables relacionadas con una mayor diferencia de puntuación respecto a la categoría basal y ajustado por el resto de variables fueron: sexo (chico=1,54) y nota académica (excelente=-2,38) para CAMI, y nacionalidad (extranjera=0,82) y nota académica (excelente=-1,30) para RIBS. La puntuación media de RIBS fue 8,83 (3,36), siendo la mayor diferencia de puntuación respecto a la categoría basal la nacionalidad extranjera (beta=0,82) y tener una nota de excelente (1,30). La búsqueda de ayuda fue mayor en padres/madres y amigos, con diferencias según sexo y nacionalidad. CONCLUSIONS: El nivel de alfabetización de salud mental es medio-bajo. Mientras que género, nacionalidad y resultados académicos son los factores que se relacionan con conocimientos y estigma, el nivel socioeconómico se relaciona únicamente con conocimientos en salud mental.
Assuntos
Letramento em Saúde , Transtornos Mentais , Masculino , Feminino , Humanos , Adolescente , Saúde Mental , Estudos Transversais , Espanha/epidemiologia , Inquéritos e QuestionáriosRESUMO
Inguinal bladder hernia (IBH) is an uncommon occurrence in males with a groin mass. It may be present with lower urinary tract symptoms but is often asymptomatic, making it a diagnostic challenge. IBH is frequently an incidental finding during surgery, which increases the risk of iatrogenic injury of the bladder. This report examines the case of a 77-year-old male who experienced a painful, reducible right-sided groin mass with acute urinary retention. Investigations conducted through computed tomography exhibited a right indirect inguinal hernia containing omental fat and a portion of the urinary bladder. The patient underwent a right open herniorrhaphy with mesh repair. This report presents a systematic approach to differential diagnoses for a male groin mass and its relationship to IBH.
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Despite the addition of several new agents to the armamentarium for the treatment of multiple myeloma (MM) in the last decade and improvements in outcomes, the refractory and relapsing disease continues to take a great toll, limiting overall survival. Therefore, additional novel approaches are needed to improve outcomes for MM patients. The oncogenic transcription factor MYC drives cell growth, differentiation and tumor development in many cancers. MYC protein levels are tightly regulated by the proteasome and an increase in MYC protein expression is found in more than 70% of all human cancers, including MM. In addition to the ubiquitin-dependent degradation of MYC by the 26S proteasome, MYC levels are also regulated in a ubiquitin-independent manner through the REGγ activation of the 20S proteasome. Here, we demonstrate that a small molecule activator of the 20S proteasome, TCH-165, decreases MYC protein levels, in a manner that parallels REGγ protein-mediated MYC degradation. TCH-165 enhances MYC degradation and reduces cancer cell growth in vitro and in vivo models of multiple myeloma by enhancing apoptotic signaling, as assessed by targeted gene expression analysis of cancer pathways. Furthermore, 20S proteasome enhancement is well tolerated in mice and dogs. These data support the therapeutic potential of small molecule-driven 20S proteasome activation for the treatments of MYC-driven cancers, especially MM.
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In recent years, there has been an increase in studies evaluating the effectiveness of mental health literacy programs within the context of education as a universal, preventive intervention. A systematic review and meta-analysis regarding the effectiveness of mental health literacy interventions in schools, from 2013 to the present, on mental health knowledge, stigma, and help-seeking is conducted. Of the 795 identified references, 15 studies met the inclusion criteria. Mental health knowledge increased after the interventions (standardized mean difference: SMD = 0.61; 95% CI (0.05, 0.74)), at two months (SMD = 0.60; 95% CI (0.4, 1.07)) and six months (SMD = 0.39; 95% CI (0.27, 0.51)). No significant differences were observed between stigma and improving help-seeking. Mental health literacy interventions are effective in augmenting mental health knowledge, but not in reducing stigma or improving help-seeking behavior.
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Breast cancer is the most commonly diagnosed cancer in women and the second most common cause of cancer-related deaths in the United States. Although early detection has significantly decreased breast cancer mortality, patients diagnosed with distant metastasis still have a very poor prognosis. The most common site that breast cancer spreads to are local lymph nodes. Therefore, the presence of lymph node metastasis remains one of most important prognostic factors in breast cancer patients. Given its significant clinical implications, increased efforts have been dedicated to better understand the molecular mechanism governing lymph node metastasis in breast cancer. The identification of lymphatic-specific biomarkers, including podoplanin and LYVE-1, has propelled the field of lymphatic metastasis forward. In addition, several animal models such as cell line-derived xenografts, patient-derived xenografts, and spontaneous tumor models have been developed to recreate the process of lymphatic metastasis. Moreover, the incorporation of various -omic platforms have provided further insight into the genetic drivers facilitating lymphatic metastasis, as well as potential biomarkers and therapeutic targets. Here, we highlight various models of lymphatic metastasis, their potential pitfalls, and other tools available to study lymphatic metastasis including imaging modalities and -omic studies.
Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/patologia , Linfonodos/patologia , Metástase Linfática/diagnóstico , Animais , Biomarcadores Tumorais/metabolismo , Mama/patologia , Neoplasias da Mama/diagnóstico , Linhagem Celular Tumoral , Feminino , Humanos , Linfonodos/diagnóstico por imagem , Metástase Linfática/patologia , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Experimentais , Glicoproteínas de Membrana/análise , Glicoproteínas de Membrana/metabolismo , Camundongos , Camundongos Transgênicos , Invasividade Neoplásica/patologia , Prognóstico , Proteínas de Transporte Vesicular/análise , Proteínas de Transporte Vesicular/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Here we describe a 27-year-old woman, 5 months post partum, who presented to the emergency department with bilateral breast masses. She was initially treated as lactational mastitis with no improvement. Breast ultrasound showed bilateral breast and axillary lymphadenopathy suggestive of metastatic/neoplastic process, and chest X-ray showed a large anterior mediastinal mass. Further work-up led to the diagnosis of T-cell acute lymphoblastic leukaemia. The patient was started on a paediatric regimen using the children's oncology group AALL0434 protocol. The patient achieved a complete remission following induction chemotherapy with resolution of her presenting symptoms.
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Neoplasias da Mama , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Adulto , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Feminino , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológicoRESUMO
INTRODUCTION: The effect of germline BRCA mutations on the outcomes of patients with triple-negative breast cancer (TNBC) is not well understood. MATERIALS AND METHODS: The present retrospective study included women with newly diagnosed TNBC from January 1, 2004 to December 30, 2013. The demographic and tumor characteristics, genetic testing results, and outcomes were collected by a review of the patients' medical records. The outcomes were compared between the BRCA+ and BRCA- women. Kaplan-Meier curves were plotted for survival analysis, and Cox proportional hazard regression was used to determine the predictors of recurrence-free survival. RESULTS: A total of 266 TNBC patients who had undergone BRCA testing were included in the final analysis. Of the 266 patients, 72 (27.0%) tested positive for a pathogenic BRCA mutation and 194 (73.0%) tested negative. BRCA+ women were more likely to be diagnosed with breast cancer at a younger age than were the BRCA- women. Mutation carriers were also more likely to undergo bilateral mastectomy and less likely to receive radiation. The 2- and 5-year overall survival in BRCA+ women was 97.1% and 83.1% and was 97.3% and 89.7% in the BRCA- women, respectively. No statistically significant difference was found in overall survival between the BRCA+ and BRCA- group. No statistically significant difference was noted in the rate of locoregional recurrence, distant recurrence, or recurrence-free survival between the BRCA+ and BRCA- women. CONCLUSION: Our study has demonstrated that BRCA mutation carrier status does not affect overall survival or recurrence-free survival in patients with TNBC.
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Genes BRCA1 , Genes BRCA2 , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/mortalidade , Adulto , Idoso , Estudos de Coortes , Intervalo Livre de Doença , Mutação em Linhagem Germinativa , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Estudos RetrospectivosRESUMO
At the Ediacaran/Cambrian boundary, ecosystems witnessed an unparalleled biological innovation: the appearance of shelled animals. Here, we report new paleoecological and paleobiological data on Cloudina, which was one of the most abundant shelled animals at the end of the Ediacaran. We report the close association of Cloudina tubes with microbial mat textures as well as organic-rich material, syndepositional calcite and goethite cement between their flanges, thus reinforcing the awareness of metazoan/microorganism interactions at the end of the Ediacaran. The preservation of in situ tubes suggests a great plasticity of substrate utilization, with evidence of different life modes and avoidance behavior. Geochemical analysis revealed walls composed of two secondary laminae and organic sheets. Some walls presented boreholes that are here described as predation marks. Taken together, these data add further information regarding the structuring of shelled animal communities in marine ecosystems.
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Exoesqueleto/fisiologia , Biomineralização/fisiologia , Ecossistema , Exoesqueleto/anatomia & histologia , Animais , Brasil , Carbonato de Cálcio/química , Fósseis , Modelos Biológicos , Análise Espectral Raman , Fatores de TempoRESUMO
The ability of an antimicrobial, cationic polyethylenimine (PEI+) to induce the three known extracytoplasmic stress responses of Escherichia coli was quantified. Exposure of E. coli to PEI+ in solution revealed specific, concentration-dependent induction of the Cpx extracytoplasmic cellular stress response, ~2.0-2.5-fold at 320 µg/mL after 1.5 h without significant induction of the σ(E) or Bae stress responses. In comparison, exposure of E. coli to a non-antimicrobial polymer, poly(ethylene oxide) (PEO), resulted in no induction of the three stress responses. The antimicrobial small molecule vanillin, a known membrane pore-forming compound, was observed to cause specific, concentration-dependent induction of the σ(E) stress response, ~6-fold at 640 µg/mL after 1.5 h, without significant induction of the Cpx or Bae stress responses. The different stress response induction profiles of PEI+ and vanillin suggest that although both are antimicrobial compounds, they interact with the bacterial membrane and extracytoplasmic area by unique mechanisms. EPR studies of liposomes containing spin-labeled lipids exposed to PEI+, vanillin, and PEO reveal that PEI+ and PEO increased membrane stability, whereas vanillin was found to have no effect.
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Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Polietilenoimina/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismoRESUMO
The current study describes the development of a small animal, closed-joint model of traumatic anterior cruciate ligament (ACL) and meniscal rupture. This model can be used in future studies to investigate the roles of these acute damages on the long-term health of an injured knee joint. Forty-two Flemish Giant rabbits received an insult to the left tibiofemoral joint ex vivo in order to document optimal energy and joint orientation needed to generate ACL and meniscal rupture, without gross fracture of bone. Impact energies ranged from 10 J to 22 J, and joint flexion angle ranged from 60 deg to 90 deg. Three in vivo animals were impacted at 13 J with the knee flexed at 90 deg, as this was determined to be the optimal load and joint orientation for ACL and meniscal ruptures, and sacrificed at 12 weeks. Impact data from the ex vivo group revealed that 13 J of dropped-mass energy, generating approximately 1100 N of load on the knee, would cause ACL and meniscal ruptures, without gross bone fracture. Acute damage to the lateral and medial menisci was documented in numerous ex vivo specimens, with isolated lateral meniscal tears being more frequent than isolated medial tears in other cases. The in vivo animals showed no signs of ill health or other physical complications. At 12 week post-trauma these animals displayed marked degeneration of the traumatized joint including synovitis, cartilage erosion, and the formation of peripheral osteophytes. Histological microcracks at the calcified cartilage-subchondral bone interface were also evident in histological sections of these animals. A closed-joint model of traumatic ACL and meniscal rupture was produced, without gross bone fracture, and a pilot, in vivo study showed progressive joint degeneration without any other noticeable physical impairments of the animals over 12 weeks. This closed-joint, traumatic injury model may be useful in future experimental studies of joint disease and various intervention strategies.
Assuntos
Lesões do Ligamento Cruzado Anterior , Lesões do Menisco Tibial , Animais , Fenômenos Biomecânicos , Engenharia Biomédica , Modelos Animais de Doenças , Articulações/lesões , Articulações/patologia , Projetos Piloto , Coelhos , Ruptura , Estresse Mecânico , Suporte de Carga/fisiologiaRESUMO
The knee is often a site of injury that can often lead to a chronic disease known as osteoarthritis (OA). The disease may be initiated, in part, by acute injuries to joint cartilage and its cells. In a recent study by this laboratory, using Flemish Giant rabbits, an impact compressive load on the tibial femoral joint was shown to cause significant levels of acute damage to chondrocytes in cartilage of the medial and lateral tibial plateaus. In the current study, using the same model, histological and mechanical data from the plateaus were documented at 6 and 12 months post impact, and compared to the unimpacted control limbs and a limb from unimpacted, control animals. The mechanical properties of cartilage were measured with indentation relaxation tests on the medial and lateral plateaus in regions covered and uncovered by the meniscus. The histological studies on impacted limbs showed surface lesions on both plateaus, thickening of the underlying subchondral bone at 12 months and numerous occult microcracks at the calcified cartilage-subchondral bone interface at 6 and 12 months, without significant changes in cartilage thickness or its mechanical properties versus controls. Yet, there was an increase in both the matrix and fiber moduli and a decrease in the permeability of uncovered, medial plateau cartilage in both limbs of impacted animals between 6 and 12 months post impact that was not documented in control animals.
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Cartilagem Articular/lesões , Cartilagem Articular/fisiopatologia , Modelos Animais de Doenças , Tíbia/lesões , Tíbia/fisiopatologia , Ferimentos não Penetrantes/fisiopatologia , Animais , Cartilagem Articular/patologia , Doença Crônica , Módulo de Elasticidade , Fêmur/lesões , Fêmur/patologia , Fêmur/fisiopatologia , Humanos , Coelhos , Tíbia/patologia , Ferimentos não Penetrantes/patologiaRESUMO
BACKGROUND: Injury patterns of the meniscus following impact trauma resulting in anterior cruciate ligament (ACL) rupture are not well understood. This study explored the spatial and temporal distribution of meniscal tears in a novel in vivo lapine model. METHODS: Skeletally mature Flemish Giant rabbits were subjected to either tibiofemoral impaction resulting in ACL rupture or surgical ACL transection. Meniscal damage was assessed acutely and after 12 wk for traumatically torn, and after 12 wk in ACL transected animals. Morphological grading was assessed using previously established criteria, and descriptions of meniscal damage were diagnosed by a Board certified orthopedist. Histological assessment was also made on 12 wk traumatically torn and ACL transected animals using Fast-Green/Safranin-O staining. RESULTS: Traumatic ACL rupture resulted in acute tears predominately in the lateral menisci. Animals subjected to both surgical transection and traumatic ACL rupture experienced degradation of the lateral and medial menisci 12 wk after injury. However, traumatic ACL rupture resulted in acute lateral damage and chronic degradation of the menisci, as well as more severe degradation of the menisci 12 wk after injury. CONCLUSIONS: This study showed that unconstrained high-intensity impacts on the tibiofemoral joint lead to meniscal damage in conjunction with ACL ruptures. Both acute and chronic changes to the menisci following traumatic impaction were observed. This research has implications for the future use of lapine models for osteoarthritis, as it incorporates traumatic loading as a more realistic mode contributing to the progression of osteoarthritis (OA) compared to surgically transected models.
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Lesões do Ligamento Cruzado Anterior , Meniscos Tibiais/patologia , Osteoartrite/cirurgia , Animais , Modelos Animais de Doenças , Fêmur/lesões , Fêmur/patologia , Osteoartrite/complicações , Osteoartrite/patologia , Coelhos , Ruptura Espontânea/etiologia , Tíbia/lesões , Tíbia/patologia , Lesões do Menisco Tibial , Suporte de CargaRESUMO
Recent studies have indicated that there may be a correlation between acute chondrocyte damage and joint degeneration reminiscent of early-stage osteoarthritis (OA). P188 surfactant has been shown to acutely restore the integrity of damaged chondrocytes; however, its long-term efficacy is unknown. The hypothesis of this study was that a single injection of P188 into a traumatized joint would acutely repair damaged cell membranes and maintain their viability in the long term. Twelve rabbits were divided into two groups, with and without P188, and sacrificed 4 days after tibiofemoral (TF) impact. Another six rabbits were sacrificed after 6 weeks and divided into two groups, with and without P188 treatment immediately posttrauma. Treatment with P188 increased the viable cell density 4 days posttrauma. A higher density of viable cells was also documented 6 weeks posttrauma in the treated versus untreated limb. The results of the current study confirm the acute efficacy of P188 treatment, and may suggest long-term efficacy of treatment, but additional studies are still needed to investigate the chronic implications of the acute repair of cells in the traumatized joint.
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Cartilagem Articular/efeitos dos fármacos , Condrócitos/efeitos dos fármacos , Poloxâmero/farmacologia , Joelho de Quadrúpedes/efeitos dos fármacos , Tensoativos/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Cartilagem Articular/lesões , Cartilagem Articular/patologia , Contagem de Células , Sobrevivência Celular/efeitos dos fármacos , Condrócitos/patologia , Modelos Animais de Doenças , Coelhos , Joelho de Quadrúpedes/lesões , Joelho de Quadrúpedes/patologia , Resultado do Tratamento , Ferimentos não Penetrantes/tratamento farmacológico , Ferimentos não Penetrantes/patologiaRESUMO
Epidemiological studies show that tibial plateau fractures comprise about 10% of all below-knee injuries in car crashes. Studies from this laboratory document that impacts to the tibiofemoral (TF) joint at 50% of the energy producing gross fracture can generate cartilage damage and microcracks at the interface between calcified cartilage and underlying subchondral bone in the tibial plateau. These injuries are suggestive of the initiation for a long term chronic disease, such as osteoarthritis. The disease process may be further encouraged by acute damage to chondrocytes in the cartilage overlying areas of occult microcracking. The hypothesis of the current study was that significant damage to chondrocytes in tibial plateau cartilage could be generated in areas of high contact pressure by a single impact delivered to the rabbit TF joint, without a gross fracture of bone. Three rabbits received a single, 13 J of energy blunt insult to the TF joint, while another three animals were used as controls. Cell viability analyses compared chondrocyte damage in impacted versus control cartilage. Two additional rabbits were impacted to document contact pressures generated in the TF joint. The study showed high contact pressures in uncovered areas of the plateau, with a trend for higher pressures in the lateral versus medial facets. A significantly higher percentage of damaged chondrocytes existed in impacted versus the opposite, nonimpacted limbs. Additionally, more chondrocyte damage was documented in the superficial zone (top 20% of cartilage thickness) of the cartilage compared to middle (middle 50% of thickness) and deep (bottom 30% of thickness) zones. This study showed that a single blunt insult to the in situ rabbit TF joint, generating large areas of contact pressure exceeding 20 MPa, produces significant chondrocyte damage in the tibial articular cartilage, especially in the superficial zone, without gross fracture of bone. Future studies will be needed to investigate the long term, chronic outcome of this blunt force joint trauma.
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Condrócitos/patologia , Condrócitos/fisiologia , Fraturas de Cartilagem/patologia , Fraturas de Cartilagem/fisiopatologia , Traumatismos do Joelho/patologia , Traumatismos do Joelho/fisiopatologia , Estimulação Física/efeitos adversos , Animais , Fraturas de Cartilagem/etiologia , Traumatismos do Joelho/etiologia , Articulação do Joelho/patologia , Articulação do Joelho/fisiopatologia , Pressão , CoelhosRESUMO
In Escherichia coli, the CpxR/A two-component system senses various types of extracytoplasmic stresses and responds by activating the expression of genes encoding periplasmic protein folding and trafficking factors that clear such stresses to ensure the organism's survival. The cpxP gene encodes a small, stress-combative periplasmic protein and is the most strongly induced member of the Cpx regulon. We demonstrate that the Cpx stress response suppresses the toxicity associated with two misfolded proteins derived from the P pilus of uropathogenic E. coli and that mutations in either cpxP or the gene for the periplasmic protease DegP prevent suppression by preventing the degradation of these proteins. Strikingly, the presence of a periplasmic misfolded protein substrate significantly enhances the proteolysis of CpxP by DegP. Our data suggest that CpxP functions as a periplasmic adaptor protein that is required for the effective proteolysis of a subset of misfolded substrates by the DegP protease.
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Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas de Choque Térmico/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Periplásmicas/metabolismo , Serina Endopeptidases/metabolismo , Adesinas de Escherichia coli/metabolismo , Citoplasma , Escherichia coli/citologia , Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/farmacologia , Proteínas de Fímbrias/metabolismo , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Proteínas de Membrana/farmacologia , Dobramento de Proteína , ATPases Translocadoras de Prótons/metabolismo , Especificidade por SubstratoRESUMO
Advanced techniques for observing protein localization in live bacteria show that the distributions are dynamic. For technical reasons, most such techniques have not been applied to outer membrane proteins in Gram-negative bacteria. We have developed two novel live-cell imaging techniques to observe the surface distribution of LamB, an abundant integral outer membrane protein in Escherichia coli responsible for maltose uptake and for attachment of bacteriophage lambda. Using fluorescently labelled bacteriophage lambda tails, we quantitatively described the spatial distribution and dynamic movement of LamB in the outer membrane. LamB accumulated in spiral patterns. The distribution depended on cell length and changed rapidly. The majority of the protein diffused along spirals extending across the cell body. Tracking single particles, we found that there are two populations of LamB--one shows very restricted diffusion and the other shows greater mobility. The presence of two populations recalls the partitioning of eukaryotic membrane proteins between 'mobile' and 'immobile' populations. In this study, we have demonstrated that LamB moves along the bacterial surface and that these movements are restricted by an underlying dynamic spiral pattern.
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Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Receptores Virais/metabolismo , Bacteriófago lambda/metabolismo , Bacteriófago lambda/ultraestrutura , Membrana Celular/metabolismo , Escherichia coli/ultraestrutura , Coloide de Ouro/metabolismo , PorinasRESUMO
The Drosophila salivary gland is a simple tubular organ derived from a contiguous epithelial primordium, which is established by the activities of the homeodomain-containing proteins Sex combs reduced (SCR), Extradenticle (EXD), and Homothorax (HTH). EGF signaling along the ventral midline specifies the salivary duct fate for cells in the center of the primordium, while cells farther away from the source of EGF signal adopt a secretory cell fate. EGF signaling works, at least in part, by repressing expression of secretory cell genes in the duct primordium, including fork head (fkh), which encodes a winged-helix transcription factor. FKH, in turn, represses trachealess (trh), a duct-specific gene initially expressed throughout the salivary gland primordium. trh encodes a basic helix-loop-helix PAS-domain containing transcription factor that has been proposed to specify the salivary duct fate. In conflict with this model, we find that three genes, dead ringer (dri), Serrate (Ser), and trh itself, are expressed in the duct independently of trh. Expression of all three duct genes is repressed in the secretory cells by FKH. We also show that SER in the duct cells signals to the adjacent secretory cells to specify a third cell type, the imaginal ring cells. Thus, localized EGF- and Notch-signaling transform a uniform epithelial sheet into three distinct cell types. In addition, Ser directs formation of actin rings in the salivary duct.