695 research outputs found

    Fluorescent Plasmodium berghei sporozoites and pre-erythrocytic stages: a new tool to study mosquito and mammalian host interactions with malaria parasites.

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    To track malaria parasites for biological studies within the mosquito and mammalian hosts, we constructed a stably transformed clonal line of Plasmodium berghei, PbFluspo, in which sporogonic and pre-erythrocytic liver-stage parasites are autonomously fluorescent. A cassette containing the structural gene for the FACS-adapted green fluorescent protein mutant 2 (GFPmut2), expressed from the 5' and 3' flanking sequences of the circumsporozoite (CS) protein gene, was integrated and expressed at the endogenous CS locus. Recombinant parasites, which bear a wild-type copy of CS, generated highly fluorescent oocysts and sporozoites that invaded mosquito salivary glands and were transmitted normally to rodent hosts. The parasites infected cultured hepatocytes in vitro, where they developed into fluorescent pre-erythrocytic forms. Mammalian cells infected by these parasites can be separated from non-infected cells by fluorescence activated cell sorter (FACS) analysis. These fluorescent insect and mammalian stages of P. berghei should be useful for phenotypic studies in their respective hosts, as well as for identification of new genes expressed in these parasite stages

    Plasmodium translocon component EXP2 facilitates hepatocyte invasion

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    Plasmodium parasites possess a translocon that exports parasite proteins into the infected erythrocyte. Although the translocon components are also expressed during the mosquito and liver stage of infection, their function remains unexplored. Here, using a combination of genetic and chemical assays, we show that the translocon component Exported Protein 2 (EXP2) is critical for invasion of hepatocytes. EXP2 is a pore-forming protein that is secreted from the sporozoite upon contact with the host cell milieu. EXP2-deficient sporozoites are impaired in invasion, which can be rescued by the exogenous administration of recombinant EXP2 and alpha-hemolysin (an S. aureus pore-forming protein), as well as by acid sphingomyelinase. The latter, together with the negative impact of chemical and genetic inhibition of acid sphingomyelinase on invasion, reveals that EXP2 pore-forming activity induces hepatocyte membrane repair, which plays a key role in parasite invasion. Overall, our findings establish a novel and critical function for EXP2 that leads to an active participation of the host cell in Plasmodium sporozoite invasion, challenging the current view of the establishment of liver stage infection

    Estrogen receptor, progesterone receptor, and bcl-2 are markers with prognostic significance in CIN III

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    There are no known biological markers or technologies to predict the natural history of an individual CIN III. The probability of progression is considered greater with the persistence of high-risk human papillomavirus (HPV) infection and age. p53 polymorphism has been associated with cervical carcinogenesis. Hormone-induced cervical cancer is mediated by estrogen receptor (ER) and progesterone receptor (PR). In cervical cancer, increased bcl-2 and Bax immunoreactivity is generally associated with a better prognosis. The purpose of this study was to evaluate the value of HPV 16 and HPV 18 typing and p53 codon polymorphism genotyping by polymerase chain reaction and ER, PR, bcl-2, and Bax expression by immunohistochemistry in predicting the CIN III clinical behavior of CIN III lesions. We studied the expression of these prognostic factors in the CIN III adjacent to squamous cell microinvasive carcinomas of the cervix (MIC) from 29 patients with FIGO stage IA1 cervical cancer and in 25 patients with CIN III and no documented focus of invasion. In the MIC group, only the CIN III was considered at least 2 mm away from the microinvasive complex. The ER, PR, bcl-2, and Bax immunoreactivity was scored as positive (>10% staining cells) and negative (<10% staining cells). No significant difference was observed between MIC and CIN III group concerning HPV infection and p53 polymorphism. The ER, PR, bcl-2, and Bax immunohistochemical expression was stronger and more frequent in the CIN III group. After multivariable analysis, coexpression of ER, PR, and bcl-2 was the only independent factor in defining low risk of progression for CIN III. Our study suggests that coexpression of ER, PR, and bcl-2 may be a useful tool in identifying the CIN III lesions with low risk of progression to cervical cance

    Predicting nursing leadership roles of patient safety in the operating room

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    Objetivo: identificar a liderança percecionada pelos enfermeiros perioperatórios e determinar os papéis de liderança preditores da segurança do doente no bloco operatório. Método: estudo descritivo e explicativo numa amostra de 1.001 enfermeiros, com recurso ao questionário de segurança do doente no bloco operatório e ao instrumento de liderança de Quinn adaptado à saúde. No tratamento de dados utilizou-se a aplicação IBM SPSS Statistics, versão 25.0. Resultado: todas as dimensões de liderança obtiveram valor superior ao ponto médio da escala (M>4). Observado um valor mínimo no papel de Inovador (M=4,63) e máximo no Produtor (M=5,04). Os modelos de regressão permitiram salientar que os papéis de liderança são preditores da segurança do doente no bloco operatório, destacando-se os papéis Monitor, Produtor e Facilitador. Conclusão: os enfermeiros perioperatórios têm perceção moderadamente positiva do exercício da liderança, indiciando a necessidade de se promover o desenvolvimento dos diferentes papéis de liderança exercidos pelos enfermeiros gestores perioperatórios.Objective: to identify the leadership perceived by perioperative nurses and to determine the role of leadership predictors of patient safety in the operating room. Method: descriptive and explanatory study in a sample of 1,001 nurses, using the patient safety questionnaire in the operating room and Quinn’s leadership instrument adapted to health. The IBM SPSS Statistics application, version 25.0, was used in the data processing. Result: all leadership dimensions were higher than the midpoint of the scale (M>4). A minimum value was observed in the role of Innovator (M=4.63) and maximum in the Producer (M=5.04). The regression models allowed pointing out that leadership roles are predictors of patient safety in the operating room, especially the roles Monitor, Producer and Facilitator. Conclusion: perioperative nurses have moderately positive perception of leadership exercise, indicating the need to promote the development of different leadership roles exercised by perioperative management nurses.Objetivo: identificar el liderazgo percebido por las enfermeras perioperatorias y determinar el papel de los predictores de liderazgo de la seguridad del paciente en el quirófano. Método: estudio descriptivo y explicativo en una muestra de 1.001 enfermeras, utilizando el cuestionario de seguridad del paciente en el quirófano y el instrumento de liderazgo de Quinn adaptado a la salud. La aplicación IBM SPSS Statistics, versión 25.0, se utilizó en el procesamiento de datos. Resultado: todas las dimensiones de liderazgo fueron superiores al punto medio de la escala (M>4). Se observó un valor mínimo en el rol de Innovador (M=4,63) y máximo en el Productor (M=5,04). Los modelos de regresión permitieron señalar que los roles de liderazgo son predictores de la seguridad del paciente en el quirófano, especialmente los roles Monitor, Productor y Facilitador. Conclusión: las enfermeras perioperatorias tienen una percepción moderadamente positiva del ejercicio de liderazgo, indicando la necesidad de promover el desarrollo de diferentes roles de liderazgo ejercidos por las enfermeras administradoras de quirofanoinfo:eu-repo/semantics/publishedVersio

    Dying in the emergency service: nurses’ attitudes before and after the first critical period of COVID-19

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    Background: Death is an increasingly frequent event in hospitals, and nurses are the health professionals who live with this reality the most. The pandemic caused by COVID-19 made this event more present, showing that nurses’ attitudes toward death may influence the care provided to people at the end of life. The objective of this study was to analyze the attitudes of nurses in the emergency service toward death, before and after the first critical period of the pandemic by COVID-19 in Portugal. Methods: A quantitative, comparative, and cross-sectional study was conducted in a hospital in Northern Portugal at 2 different moments: the first in February 2018 and the second in May 2020, after the first critical period of the pandemic by COVID-19. In both moments, data were collected using a self-completion questionnaire, which included the Death Attitude Profile Assessment Scale. Results: The attitudes fear, avoidance, closeness, and escape did not show significant differences. In neutral/neutral acceptance, differences were found between the first and second moments of data collection (P=.01), with a lower mean after the critical period of the pandemic. Conclusions: The results obtained in 2018 and 2020 showed slight changes in attitudes toward death. The need to invest in the training and preparation of nurses who deal directly with death and the dying process was evident. Nurse managers should promote spaces for reflection and team training on death, aiming to reduce the professionals’ suffering and anxiety.info:eu-repo/semantics/publishedVersio

    A Post Hoc Analysis on Rhythm and High Intensity Interval Training in Cardiac Resynchronization Therapy

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    Objectives. Evaluate the effects of a 6-month High Intensity Interval Training (HIIT) program on (1) functional capacity and health-related quality of life, (2) multiple blood biomarkers, (3) echocardiographic parameters, and (4) exercise performance, in patients in cardiac resynchronization therapy (CRT) stratified by the presence of atrial fibrillation (AF), targeting the following questions: (1) Does CRT provide similar benefits in patients in AF and sinus rhythm (SR)?; and (2) Does HIIT provides similar benefits in patients in AF and SR? Design. Estimates were available at baseline and 6 months after CRT implantation in 37 patients with heart failure. Patients were randomized after CRT to a 24-week HIIT group or to a usual care group (CON). In this sub-analysis, HIIT (AF = 7; SR = 11) and CON (AF = 9; SR = 10) were stratified by the presence of AF. Results. Patients in AF benefitted to a lesser degree from CRT in functional status than patients in SR (23.8-46.0%). However, HIIT induced superior improvements in patients in AF compared to CON (23.9-61.0%). Decreases in TNF-α (8.5-42.9%), BNP (15.3-34.6%) and left ventricular mass (9.6-26.2%) were only observed in patients in SR, whereas increases in peak oxygen uptake were only observed in patients in AF (19.5-23.2%). HIIT improved exercise capacity (8.8-59.4%) in patients in SR. Conclusions. Patients in AF or SR undergoing CRT demonstrated distinct benefits from device implantation and from HIIT as an adjunctive therapeutic strategy. This suggests that both mainstay and adjunctive therapeutics may need to be managed differently in patients in AF and SR.info:eu-repo/semantics/publishedVersio

    Deposition and passage of transthyretin through the blood-nerve barrier in recipients of familial amyloid polyneuropathy livers

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    Familial amyloid polyneuropathy (FAP) is characterized by deposition of mutated transthyretin (TTR) in the peripheral nervous system. Prior to amyloid fibrils, nonfibrillar TTR aggregates are deposited inducing oxidative stress with increased nitration (3-NT). As the major source of TTR is the liver, liver transplantation (LT) is used to halt FAP. Given the shortage of liver donors, domino LT (DLT) using FAP livers is performed. The correlation between TTR deposition in the skin and nerve was tested in biopsies from normal individuals, asymptomatic carriers (FAP 0) and FAP patients; in FAP 0, nonfibrillar TTR was observed both in the skin and nerve in the same individuals; in patients, amyloid was detected in both tissues. The occurrence of amyloidosis in recipients of FAP livers was evaluated 1-7 years after DLT: TTR deposition occurred in the skin 3 years after transplantation either as amyloid or aggregates; in one of the recipients, fibrillar TTR was present in the epineurium 6 years after DLT. Deposits were scarce and 3-NT immunostaining was irrelevant. Nerve biopsies from DLT recipients had no FAP-related neuropathy. Our findings suggest that TTR amyloid formation occurs faster than predicted and that TTR of liver origin can cross the blood-nerve barrier. Recipients of FAP livers should be under surveillance for TTR deposition and tissue damag

    High-Intensity Interval Training in Cardiac Resynchronization Therapy: a Randomized Control Trial

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    AIMS: To determine the effects of high-intensity interval training (HIIT) following cardiac resynchronization therapy (CRT) implantation in patients with chronic heart failure (CHF), on noninvasive estimates of systolic ventricular function, exercise performance, severity of symptoms and quality of life. METHODS: Cardiopulmonary exercise testing, resting transthoracic echocardiogram and health-related quality of life assessment were obtained before and at 6 months after CRT implantation in 37 patients with moderate-to-severe CHF. Patients were randomized after CRT to either a 24-week HIIT group (90-95% peak heart rate, 2 days per week) or to a usual care group (CON). Mixed design 2 × 2 repeated measures ANOVA were used to test for differences within and in-between groups. RESULTS: Improvements in health-related quality of life (HIIT = 98.54%, CON = 123.47%), NYHA class (HIIT = 43.44%, CON = 38.30%) HR recovery at minute 1 (HIIT = 32.32%, CON = 42.94%), pulse pressure at peak effort (HIIT = 14.06%, CON = 9.52%, LVEF (HIIT = 42.17%, CON = 51.10%) and LV Mass (HIIT = 13.26%, CON = 11.88%) were similar in both groups (p > 0.05). Significant increases in CPET duration in the HIIT group (25.94%), and increases in peak VO2 (HIIT = 8.64%, CON = 4.85%) and percent-predicted VO2 (HIIT = 10.57%, CON = 4.26%) in both groups, were observed in the intention-to-treat analysis. CONCLUSION: Six months of HIIT in patients in CRT did not further improved indices of functional capacity and health-related quality of life, and LV structure and function, compared to CRT alone. However, HIIT led to further improvements in exercise performance. It remains unclear whether HIIT benefits patients in CRT to a similar degree as more conventional forms of exercise training previously shown to maximize benefits in CRT.info:eu-repo/semantics/publishedVersio

    Highly Dynamic Host Actin Reorganization around Developing Plasmodium Inside Hepatocytes

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    Plasmodium sporozoites are transmitted by Anopheles mosquitoes and infect hepatocytes, where a single sporozoite replicates into thousands of merozoites inside a parasitophorous vacuole. The nature of the Plasmodium-host cell interface, as well as the interactions occurring between these two organisms, remains largely unknown. Here we show that highly dynamic hepatocyte actin reorganization events occur around developing Plasmodium berghei parasites inside human hepatoma cells. Actin reorganization is most prominent between 10 to 16 hours post infection and depends on the actin severing and capping protein, gelsolin. Live cell imaging studies also suggest that the hepatocyte cytoskeleton may contribute to parasite elimination during Plasmodium development in the liver

    Transition of plasmodium sporozoites into liver stage-like forms is regulated by the RNA binding protein pumilio

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    Many eukaryotic developmental and cell fate decisions that are effected post-transcriptionally involve RNA binding proteins as regulators of translation of key mRNAs. In malaria parasites (Plasmodium spp.), the development of round, non-motile and replicating exo-erythrocytic liver stage forms from slender, motile and cell-cycle arrested sporozoites is believed to depend on environmental changes experienced during the transmission of the parasite from the mosquito vector to the vertebrate host. Here we identify a Plasmodium member of the RNA binding protein family PUF as a key regulator of this transformation. In the absence of Pumilio-2 (Puf2) sporozoites initiate EEF development inside mosquito salivary glands independently of the normal transmission-associated environmental cues. Puf2- sporozoites exhibit genome-wide transcriptional changes that result in loss of gliding motility, cell traversal ability and reduction in infectivity, and, moreover, trigger metamorphosis typical of early Plasmodium intra-hepatic development. These data demonstrate that Puf2 is a key player in regulating sporozoite developmental control, and imply that transformation of salivary gland-resident sporozoites into liver stage-like parasites is regulated by a post-transcriptional mechanism
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