Práticas profissionais no primeiro encontro dos pais com recém-nascido na unidade neonatal / Professional practices in the first meeting between parents and newborn in the neonatal unit / Prácticas profesionales en el primer encuentro entre padres y recién nacido en la unidad neonatal

Objetivo: analisar as práticas profissionais no primeiro encontro dos pais com recém-nascido na unidade neonatal. Método: estudo quantitativo, descritivo e transversal, desenvolvido com 69 profissionais de saúde da unidade de terapia intensiva neonatal de um Hospital Universitário no Rio de Janeiro, após aprovação pelo Comitê de Ética em Pesquisa. Os dados foram coletados no período de março a julho de 2021, por meio de questionário online, e analisados mediante estatística descritiva simples, percentual e média. Resultados: as práticas profissionais foram adequadas quanto possibilitar aos pais: o toque materno/paterno (91,3%); o livre acesso à unidade neonatal (86,9%); e a realização de cuidados com o bebê (81,1%). Conclusão: a maioria das práticas profissionais está alinhada às recomendações do Método Canguru. Contudo, as fragilidades relativas ao acolhimento evidenciam lacunas na abordagem da temática na formação profissional e em atividades de educação continuada.

Objective: to examine the professional practices in the first meeting between parents and newborn in the neonatal unit. Method: in this quantitative, descriptive, cross-sectional study conducted with 69 health personnel from the neonatal intensive care unit of a university hospital in Rio de Janeiro, after approval by the research ethics committee, data were collected from March to July 2021 by online survey and analyzed using simple percentage and average descriptive statistics. Results: the professional practices were appropriate in that they allowed parents: maternal/paternal touch (91.3%); free access to the neonatal unit (86.9%); and to provide care for the baby (81.1%). Conclusion: the professional practices were mostly in line with the recommendations of the Kangaroo Method. However, weaknesses in receptiveness highlighted gaps in how the subject was approached in training activities and continued professional development.

Objetivo: analizar las prácticas profesionales en el primer encuentro entre padres y recién nacido en la unidad neonatal. Método: estudio cuantitativo, descriptivo y transversal, desarrollado con 69 profesionales de la salud de la unidad de cuidados intensivos neonatales de un Hospital Universitario de Rio de Janeiro, previa aprobación del Comité de Ética en Investigación. Los datos fueron recolectados de marzo a julio de 2021, a través de una encuesta en línea, y analizados mediante estadística descriptiva simple, porcentaje y promedio. Resultados: las prácticas profesionales fueron adecuadas en cuanto a posibilitar a los padres: el toque materno/paterno (91,3%); el libre acceso a la unidad neonatal (86,9%); y la prestación de cuidados al bebé (81,1%). Conclusión: la mayoría de las prácticas profesionales está acorde con las recomendaciones del Método Canguro. Sin embargo, las debilidades relacionadas con la acogida evidencian lagunas acerca del enfoque del tema en la formación profesional y en actividades de educación continua.

Recursos del ambiente familiar y rendimiento de lectura en adolescentes / Recursos do ambiente familiar e desempenho de leitura em adolescentes / Family environment resources and reading performance by adolescents

Este estudo teve como objetivo verificar a associação entre os recursos do ambiente familiar e a leitura de adolescentes. Participaram 106 adolescentes, de ambos os sexos, de 11 a 16 anos, sem queixas de dificuldades de aprendizagem. Para a coleta de dados utilizou-se um texto narrativo, o questionário de múltipla escolha sobre o texto e o de Recursos do Ambiente Familiar, adaptado. Foi realizada a análise descritiva e inferencial por meio dos testes correlação de Spearman, Mann-Whitney e Kruskal Wallis, com nível de significância de 5%. Os recursos que promovem os processos proximais e as práticas parentais contribuíram para um melhor desempenho de leitura. Em contrapartida, a categoria de atividades previsíveis contribuiu negativamente. Assim, o ambiente e os recursos influenciaram o desempenho leitor dos adolescentes. Conclui-se que é importante a elaboração de medidas escolares e de políticas públicas, para fortalecer a relação família-escola, ampliar os recursos familiares e tornar o ambiente favorável ao ensino.

En este estudio se tuvo como objetivo verificar la asociación entre los recursos del ambiente familiar y la lectura de adolescentes. Participaron 106 adolescentes, de ambos sexos, de 11 a 16 años, sin quejas de dificultades de aprendizaje. Para la recopilación de datos se utilizó un texto narrativo, el cuestionario de múltiple elección sobre el texto y el de Recursos del Ambiente Familiar, adaptado. Se realizó el análisis descriptivo e inferencial por intermedio de las pruebas correlación de Spearman, Mann-Whitney y Kruskal Wallis, con nivel de significancia del 5%. Los recursos que promueven los procesos proximales y las prácticas parentales contribuyeron al mejor rendimiento de lectura. Por otro lado, la categoría de actividades previsibles contribuyó negativamente. Así, el ambiente y los recursos influenciaron el rendimiento lector de los adolescentes. Se concluye que es importante la elaboración de medidas escolares y de políticas públicas, para fortalecer la relación familia-escuela, ampliar los recursos familiares y tornar el ambiente favorable a la enseñanza.

This study aimed to verify the association between the resources of the family environment and teenage reading. A total of 106 adolescents of both sexes, aged between 11 and 16 years, without learning difficulties, participated in the study. For data collection, a narrative text, a multiple-choice questionnaire about the text and an adapted Family Environment Resources questionnaire were used. Descriptive and inferential analysis was performed using Spearman, Mann-Whitney and Kruskal Wallis correlation tests, with a significance level of 5%. Resources that promote proximal processes and parenting practices contributed to better reading performance. In contrast, the predictable activities category contributed negatively. Thus, the environment and resources influenced the adolescents' reading performance. It is concluded that the elaboration of school measures and public policies is important to strengthen the family-school relationship, expand family resources and make the environment favorable to teaching.

Suspect asymptomatic lesions: Congenital hypertrophy of the Retinal Pigment Epithelium (CHRPE).

Congenital hypertrophy of the retinal pigment epithelium is a rare benign tumor of the ocular fundus that may vary according to three types. It is frequently asymptomatic and diagnosed during routine ophthalmology exam. This lesion has an important differential diagnosis with retinal disease and may be related to systemic diseases, therefore, it is essential to recognize it and keep the follow-up. In this paper, three different cases of each type of CHRPE were described and documented. Abbreviations: CHRPE = Congenital hypertrophy of the Retinal Pigment Epithelium, RPE = Retinal Pigment Epithelium, CDVA = Corrected Distance Visual Acuity, PIO = Intraocular Pressure, FA = Fluorescein Angiography, FAP = Familial Adenomatous Polyposis, RPEH-FAP = Retinal Pigment Epithelial Hamartomas Associated with Familial Adenomatous Polyposis, OCT = Ocular Coherence Tomography.

Comparação da eficácia da retinografia colorida e da angiografia fluorescente no diagnóstico da retinopatia diabética / Comparing efficacy of fundus photography and fluorescein angiography in the diagnosis of diabetic retinopathy

RESUMO Objetivo: Avaliar a efetividade da retinografia colorida e a da angiografia fluorescente no diagnóstico e no rastreio da retinopatia diabética. Métodos: Estudo retrospectivo, com base na análise de resultados de ambos os exames de 398 pacientes diabéticos. Resultados: Os resultados da angiografia coincidiram com os da retinografia em 77,4% dos casos, e não houve diferença significativa no estadiamento e na identificação da retinopatia pelos dois métodos. Conclusão: Não houve diferença significativa em relação à capacidade diagnóstica da doença pelos métodos descritos, demonstrando não existir benefício em indicar a angiografia como avaliação inicial do paciente diabético.

ABSTRACT Objective: To assess effectiveness of fundus photography and fluorescein angiography in diagnosis and screening of diabetic retinopathy. Methods: A retrospective study of 398 diabetic patients, based on analysis of results of both tests. Results: Results of fluorescein angiography and fundus photography coincided in 77.4% of cases, and there was no significant difference in staging and identification of retinopathy by both methods. Conclusion: There was no significant difference between both methods regarding the capacity to diagnose the disease, showing no benefit in indicating fluorescein angiography as initial assessment of diabetic patients.

Consumo de drogas, rede e apoio social entre pacientes psiquiátricos ambulatoriais / Drug use, networking, and social support among outpatient psychiatric patients / Uso de drogas, red y apoyo social entre pacientes psiquiátricos ambulatorios

O consumo de drogas é elevado entre pessoas com quadros psicopatológicos e pode acarretar diversos prejuízos que se sobrepõem à morbidade psiquiátrica. A rede e o apoio social podem estar associados ao prognóstico desses indivíduos. O objetivo deste estudo foi identificar o uso problemático de drogas em indivíduos em tratamento psiquiátrico e verificar a associação entre o consumo e medidas de rede e do apoio social. A amostra foi composta por 178 participantes. Foram utilizados os instrumentos: Formulário de informações sociodemográficas e clínicas, ASSIST, MOS-SSS e Inventário sobre a Rede Social. Obteve-se que 41,6% dos participantes faziam uso problemático de drogas, sendo álcool, tabaco e maconha as mais utilizadas. Ter sido alvo de discriminação, não residir com parceiro fixo e não ser praticante de religião foram associados ao consumo problemático de drogas. Destaca-se a importância da avaliação de fatores ambientais na co-ocorrência do uso problemático de drogas e quadros clínicos psiquiátricos. AU

The consumption of drugs is high among people with psychopathological diagnoses and can cause harm that overlaps the psychiatric morbidity. The social network and support are associated with the prognosis of this population. The aim of this study was to identify problematic drug use among individuals undergoing psychiatric treatment and to verify the association between this problematic consumption and their social network and support measures. The sample consisted of 178 participants. An instrument composed of sociodemographic and clinical questions; the ASSIST; MOS-SSS; and the Social Networks Inventory were used for the data collection. It was found that 41.6% of the participants presented problematic drug use, the most used substances being alcohol, tobacco and marijuana. Having experienced discrimination, not living with a steady partner and not practicing religion were associated with the problematic drug use. The importance of environmental factors in the co-occurrence of problematic drug use and psychiatric diagnoses is highlighted. AU

El consumo abusivo de las drogas es grande entre las personas con cuadro clínico psicopatológico y puede generar daños que superponen con la morbilidad psiquiátrica. La red y el apoyo social pueden asociarse con el pronóstico de los individuos. El objetivo de este estudio fue identificar el uso problemático de drogas entre los individuos sometidos a tratamiento psiquiátrico y averiguar la relación entre consumo y medidas de la red y el apoyo social. La muestra fue compuesta por 178 participantes. Fueran utilizados los instrumentos: Formulario de Información Sociodemográfica y Clínica, ASSIST, MOS-SSS y el Inventario sobre Red Social. Se encontró que 41,6% de los participantes eran adictos a las drogas, siendo el alcohol, el tabaco y la marihuana las más utilizadas. Se asoció a la adicción a las drogas haber sufrido discriminación, no residir con pareja estable y no ser practicante religioso. Se resaltó la importancia de los factores ambientales en la co-ocurrencia de consumo problemático de las drogas y cuadros clínicos psiquiátricos. AU

Mesenchymal stem cells and cell-derived extracellular vesicles protect hippocampal neurons from oxidative stress and synapse damage induced by amyloid-ß oligomers.

Alzheimer's disease (AD) is a disabling and highly prevalent neurodegenerative condition, for which there are no effective therapies. Soluble oligomers of the amyloid-ß peptide (AßOs) are thought to be proximal neurotoxins involved in early neuronal oxidative stress and synapse damage, ultimately leading to neurodegeneration and memory impairment in AD. The aim of the current study was to evaluate the neuroprotective potential of mesenchymal stem cells (MSCs) against the deleterious impact of AßOs on hippocampal neurons. To this end, we established transwell cocultures of rat hippocampal neurons and MSCs. We show that MSCs and MSC-derived extracellular vesicles protect neurons against AßO-induced oxidative stress and synapse damage, revealed by loss of pre- and postsynaptic markers. Protection by MSCs entails three complementary mechanisms: 1) internalization and degradation of AßOs; 2) release of extracellular vesicles containing active catalase; and 3) selective secretion of interleukin-6, interleukin-10, and vascular endothelial growth factor to the medium. Results support the notion that MSCs may represent a promising alternative for cell-based therapies in AD.

Brain infusion of α-synuclein oligomers induces motor and non-motor Parkinson's disease-like symptoms in mice.

Parkinson's disease (PD) is characterized by motor dysfunction, which is preceded by a number of non-motor symptoms including olfactory deficits. Aggregation of α-synuclein (α-syn) gives rise to Lewy bodies in dopaminergic neurons and is thought to play a central role in PD pathology. However, whether amyloid fibrils or soluble oligomers of α-syn are the main neurotoxic species in PD remains controversial. Here, we performed a single intracerebroventricular (i.c.v.) infusion of α-syn oligomers (α-SYOs) in mice and evaluated motor and non-motor symptoms. Familiar bedding and vanillin essence discrimination tasks showed that α-SYOs impaired olfactory performance of mice, and decreased TH and dopamine levels in the olfactory bulb early after infusion. The olfactory deficit persisted until 45days post-infusion (dpi). α- SYO-infused mice behaved normally in the object recognition and forced swim tests, but showed increased anxiety-like behavior in the open field and elevated plus maze tests 20 dpi. Finally, administration of α-SYOs induced late motor impairment in the pole test and rotarod paradigms, along with reduced TH and dopamine content in the caudate putamen, 45 dpi. Reduced number of TH-positive cells was also seen in the substantia nigra of α-SYO-injected mice compared to control. In conclusion, i.c.v. infusion of α-SYOs recapitulated some of PD-associated non-motor symptoms, such as increased anxiety and olfactory dysfunction, but failed to recapitulate memory impairment and depressive-like behavior typical of the disease. Moreover, α-SYOs i.c.v. administration induced motor deficits and loss of TH and dopamine levels, key features of PD. Results point to α-syn oligomers as the proximal neurotoxins responsible for early non-motor and motor deficits in PD and suggest that the i.c.v. infusion model characterized here may comprise a useful tool for identification of PD novel therapeutic targets and drug screening.

Estudo transversal dos óbitos provocados por trauma nos membros necropsiados no Instituto Médico Legal de Belo Horizonte, 2006 - 2011 / Imprimir PDF Estatísticas ARTIGO ORIGINAL Estudo transversal dos óbitos provocados por trauma nos membros necropsiados no Instituto Médico Legal de Belo Horizonte, 2006 - 2011 Cross-sectional study of trauma deaths caused by extremity trauma necropsied at the Forensic Medicine Institute of Belo Horizonte, 2006 - 2011

Introdução: Nos países industrializados, o trauma é a terceira causa de mortalidade, sendo a principal entre menores de 45 anos de idade. Em Belo Horizonte (BH), no ano de 2015, quase metade das hospitalizações relacionadas a causas externas se deveu por trauma nos membros. Entretanto, a epidemiologia do trauma fatal de extremidades em nosso meio é ainda pouco conhecida. Objetivos: Avaliar os óbitos decorrentes de trauma nos membros ocorridos em BH e região metropolitana para se estabelecer o perfil das vítimas e dos subtipos deste trauma. Métodos: Estudo transversal dos casos necropsiados no Instituto Médico Legal de BH no período de 2006 a 2011 cuja causa do óbito tenha sido trauma nos membros. Resultados: Foram recuperados 128 casos. Quanto aosmecanismos de trauma, a maioria se deveu a ação contundente, seguida pela ação pérfurocontundente. O ano de 2007, o mês de outubro e o domingo apresentaram maior proporção de necropsias. A maioria dos necropsiados era homem, possuía menos de 49 anos, era solteira, feoderma e ativa do ponto de vista ocupacional. Em quase metade dos casos havia suspeita de homicídio e a maioria das vítimas foi encaminhada de uma unidade de saúde. Conclusões: A caracterização mais detalhada dos óbitos decorrentes de trauma nos membros ocorridos em BH pode fornecer informações de saúde pública importantes para o direcionamento de recursos e delineamento de prioridades para redução das fatalidades. (AU)

Introduction: In industrialized countries, trauma is the third leading cause of mortality, with the highest rate in the young. In Belo Horizonte, nearly half of hospitalizations related to external causes were due to limb trauma. However, the epidemiology of fatal trauma caused by trauma in extremities in our setting is still poorly understood. Objectives: To evaluate the limb trauma related deaths occurred in BH and metropolitan area in order to establish the profile of the victims and the subtypes of this trauma. Methods: Cross-sectional study of the necropsy reports performed at IML/BH from 2006 to 2011, caused by limb trauma. Results: 128 reports of fatal limb trauma victims were recovered during the study period. Concerning the mechanisms of trauma, the majority was due to blunt trauma, followed by gunshot wounds. The year 2007, October and Sunday had a higher proportion of necropsies. Most victims were male, younger than 49 years old, were single, feoderm and active from an occupational point of view. In almost half of the cases, homicide was suspected. Most of the cases had trauma in the lower limbs and were referred from a health unit. Conclusions: The more detailed characterization of limb trauma related deaths in BH can provide important public health information for resource allocation and delineation of priorities for fatalities reduction. (AU)

Caudoventral hip luxation in a miniature pig / Luxação caudoventral de quadril em um mini-pig

ABSTRACT: A miniature pig was examined because of left pelvic limb lameness after falling from a short height. Clinical examination and radiographs of the pelvic region revealed a left caudoventral hip luxation. Surgical reduction of luxation was performed on the patient under general anesthesia using a transarticular pinning technique. Postoperative radiographs confirmed that the luxation was reduced, the joint was aligned, and the transarticular pinning was correct. The transarticular pin was removed 21 days after it was surgically inserted. The limb was fully functional in the immediate postoperative period. Nine months after the surgery, the patient could use the limb properly, but mild degenerative joint disease was observed via radiographic follow-up. This technique may be a viable treatment option for the repair of caudoventral hip luxation in miniature pigs.

RESUMO: Um mini-pig foi atendido devido à claudicação do membro pélvico esquerdo após pequena queda. O exame clínico e radiografias da região pélvica revelaram uma luxação caudoventral de quadril no lado esquerdo. A redução cirúrgica da luxação foi realizada, com o paciente sob anestesia geral, usando um pino transarticular. As radiografias pós-operatórias confirmaram que a luxação foi reduzida, com alinhamento e fixação transarticular corretos. O pino transarticular foi removido cirurgicamente 21 dias após de ter sido inserido. O membro se tornou totalmente funcional já no período pós-operatório imediato. Nove meses após a cirurgia, o paciente utilizava o membro corretamente, porém foi detectada doença articular degenerativa leve através de acompanhamento radiográfico. A técnica empregada foi uma opção viável de tratamento para a reparação da luxação caudoventral de quadril em mini-pig.

Molecular confinement of human amylin in lipidic nanoparticles.

Amylin is a pancreatic hormone involved in the regulation of glucose metabolism and homeostasis. Restoration of the post-prandial and basal levels of human amylin in diabetic individuals is a key in controlling glycemia, controlling glucagon, reducing the insulin dose and increasing satiety, among other physiologic functions. Human amylin has a high propensity to aggregate. We have addressed this issue by designing a liposomal human amylin formulation. Nanoparticles of multilamellar liposomes comprising human amylin were obtained with 53% encapsulation efficiency. The in vitro kinetic release assay shows a biphasic profile. The stabilization of the lipidic nanoparticle against freeze-drying was achieved by using mannitol as a cryoprotectant, as evidenced by morphological characterization. The effectiveness of the human amylin entrapped in lipidic nanoparticles was tested by the measurement of its pharmacological effect in vivo after subcutaneous administration in mice. Collectively these results demonstrate the compatibility of human amylin with the lipidic interface as an effective pharmaceutical delivery system.

The importance of a gatekeeper residue on the aggregation of transthyretin: implications for transthyretin-related amyloidoses.

Protein aggregation into ß-sheet-enriched amyloid fibrils is associated with an increasing number of human disorders. The adoption of such amyloid conformations seems to constitute a generic property of polypeptide chains. Therefore, during evolution, proteins have adopted negative design strategies to diminish their intrinsic propensity to aggregate, including enrichment of gatekeeper charged residues at the flanks of hydrophobic aggregation-prone segments. Wild type transthyretin (TTR) is responsible for senile systemic amyloidosis, and more than 100 mutations in the TTR gene are involved in familial amyloid polyneuropathy. The TTR 26-57 segment bears many of these aggressive amyloidogenic mutations as well as the binding site for heparin. We demonstrate here that Lys-35 acts as a gatekeeper residue in TTR, strongly decreasing its amyloidogenic potential. This protective effect is sequence-specific because Lys-48 does not affect TTR aggregation. Lys-35 is part of the TTR basic heparin-binding motif. This glycosaminoglycan blocks the protective effect of Lys-35, probably by neutralization of its side chain positive charge. A K35L mutation emulates this effect and results in the rapid self-assembly of the TTR 26-57 region into amyloid fibrils. This mutation does not affect the tetrameric protein stability, but it strongly increases its aggregation propensity. Overall, we illustrate how TTR is yet another amyloidogenic protein exploiting negative design to prevent its massive aggregation, and we show how blockage of conserved protective features by endogenous factors or mutations might result in increased disease susceptibility.

Biophysical and morphological studies on the dual interaction of non-octarepeat prion protein peptides with copper and nucleic acids.

Conversion of prion protein (PrP) to an altered conformer, the scrapie PrP (PrP(Sc)), is a critical step in the development of transmissible spongiform encephalopathies. Both Cu(II) and nucleic acid molecules have been implicated in this conversion. Full-length PrP can bind up to six copper ions; four Cu(II) binding sites are located in the octarepeat domain (residues 60-91), and His-96 and His-111 coordinate two additional copper ions. Experimental evidence shows that PrP binds different molecules, resulting in diverse cellular signaling events. However, there is little information about the interaction of macromolecular ligands with Cu(II)-bound PrP. Both RNA and DNA sequences can bind PrP, and this interaction results in reciprocal conformational changes. Here, we investigated the interaction of Cu(II) and nucleic acids with amyloidogenic non-octarepeat PrP peptide models (comprising human PrP residues 106-126 and hamster PrP residues 109-149) that retain His-111 as the copper-anchoring residue. The effect of Cu(II) and DNA or RNA sequences in the aggregation, conformation, and toxicity of PrP domains was investigated at low and neutral pH. Circular dichroism and EPR spectroscopy data indicate that interaction of the PrP peptides with Cu(II) and DNA occurs at pH 7. This dual interaction induces conformational changes in the peptides, modulating their aggregation, and affecting the morphology of the aggregated species, resulting in different cytotoxic effects. These results provide new insights into the role of Cu(II) and nucleic acid sequences in the structural conversion and aggregation of PrP, which are both critical events related to prion pathogenesis.

Políticas de saúde no Brasil: uma visão baseada nas normas reguladoras editadas no período de 1990 a 2010 / Health politicies in Brazil: a vision based on regulatory rules published from 1990 to 2010

Com a Constituição Federal (CF) de 1988 foi criado o Sistema Único de Saúde (SUS), regulamentado pelas Leis nº 8.080/90 e nº 8.142/90. Posteriormente foi sendo construído através de normas operacionais e, mais recentemente pelo Pacto da Saúde. Neste contexto o presente estudo teve por objetivo analisar a trajetória das políticas públicas de saúde no Brasil, buscando identificar avanços que se refere à equidade e acesso universal. Para tal utiliza como instrumentos de pesquisa as legislações e os documentos oficiais e administrativos do Ministério da Saúde editados nas décadas de 1990 e 2000. Verificou-se através dos documentos e textos acadêmicos analisados que, na prática, a regulamentação do SUS ocorreu através de normas reguladoras, criadas para operar as transformações previstas na Constituição e na Lei Orgânica da Saúde. Identifica a inserção da Estratégia de Saúde da Família como política prioritária para a atenção primária e os incentivos para a mudança do modelo de atenção. Destaca a fragmentação das ações e o enfraquecimento gradativo dos estados, ator desconsiderado no processo de descentralização em curso à época. Identifica os avanços na regionalização com a edição da Norma Operacional da Assistência à Saúde, NOAS SUS 01/ 2001/2002. A década de 2000 assiste a edição da Portaria GM/MS nº 399/2006, que divulga o Pacto pela Saúde e seus desdobramentos atuais. Concluiu-se que o SUS vem sendo implementado de forma lenta e apesar dos avanços identificados mudanças no processo de financiamento e gestão são necessárias para torná-lo efetivamente, como um direito de cidadania.

Stepwise oligomerization of murine amylin and assembly of amyloid fibrils.

Amylin is a pancreatic hormone co-secreted with insulin. Human amylin has been shown to form dimers and exhibit high propensity for amyloid fibril formation. We observed the ability of the water-soluble murine amylin to aggregate in water resulting in an insoluble material with Thioflavin T binding properties. Infrared spectroscopy analysis revealed beta-sheet components in the aggregated murine amylin. Morphological analysis by transmission electron microscopy and atomic force microscopy provided access to the fibril nature of the murine amylin aggregate which is similar to amyloid fibrils from human amylin. X-ray diffraction of the murine amylin fibrils showed peaks at 4.7Å and 10Å, a fingerprint for amyloid fibrils. Electron spray ionization-ion mobility spectroscopy-mass spectrometry (ESI-IMS-MS) analysis and crosslinking assays revealed self-association intermediates of murine amylin into high order oligomeric assemblies. These data demonstrate the stepwise association mechanism of murine amylin into stable oligomers, which ultimately converges to its organization into amyloid fibrils.

Inhibition of human transthyretin aggregation by non-steroidal anti-inflammatory compounds: a structural and thermodynamic analysis.

Transthyretin (TTR) is a homotetrameric protein that circulates in plasma and cerebral spinal fluid (CSF) whose aggregation into amyloid fibrils has been associated with at least two different amyloid diseases: senile systemic amyloidosis (SSA) and familial amyloid polyneuropathy (FAP). In SSA aggregates are composed of WT-TTR, while in FAP more than 100 already-described variants have been found in deposits. Until now, TTR-related diseases have been untreatable, although a new drug called Tafamidis has been approved only in Europe to specifically treat V30M patients. Thus, new strategies are still necessary to treat FAP caused by other variants of TTR. TTR has two channels in the dimer interface that bind to the hormone thyroxin and that have been used to accommodate anti-amyloidogenic compounds. These compounds stabilize the tetramers, rendering TTR less amyloidogenic. Here, we investigated the effects of three non-steroidal anti-inflammatory compounds-sulindac (SUL), indomethacin (IND) and lumiracoxib (LUM)-as tetramer stabilizers and aggregation inhibitors. WT-TTR and the very aggressive TTR variant L55P were used as models. These compounds were able to stabilize TTR against high hydrostatic pressure (HHP), increasing the ΔGf by several kcal. They were also effective in inhibiting WT-TTR and L55P acid- or HHP-induced aggregation; in particular, LUM and IND were very effective, inhibiting almost 100% of the aggregation of both proteins under certain conditions. The species formed when aggregation was performed in the presence of these compounds were much less toxic to cells in culture. The crystal structures of WT-TTR bound to the three compounds were solved at high resolution, allowing the identification of the relevant protein:drug interactions. We discuss here the ligand-binding features of LUM, IND and SUL to TTR, emphasizing the critical interactions that render the protein more stable and less amyloidogenic.

Amyloid fibrils trigger the release of neutrophil extracellular traps (NETs), causing fibril fragmentation by NET-associated elastase.

The accumulation of amyloid fibrils is a feature of amyloid diseases, where cell toxicity is due to soluble oligomeric species that precede fibril formation or are formed by fibril fragmentation, but the mechanism(s) of fragmentation is still unclear. Neutrophil-derived elastase and histones were found in amyloid deposits from patients with different systemic amyloidoses. Neutrophil extracellular traps (NETs) are key players in a death mechanism in which neutrophils release DNA traps decorated with proteins such as elastase and histones to entangle pathogens. Here, we asked whether NETs are triggered by amyloid fibrils, reasoning that because proteases are present in NETs, protease digestion of amyloid may generate soluble, cytotoxic species. We show that amyloid fibrils from three different sources (α-synuclein, Sup35, and transthyretin) induced NADPH oxidase-dependent NETs in vitro from human neutrophils. Surprisingly, NET-associated elastase digested amyloid fibrils into short species that were cytotoxic for BHK-21 and HepG2 cells. In tissue sections from patients with primary amyloidosis, we also observed the co-localization of NETs with amyloid deposits as well as with oligomers, which are probably derived from elastase-induced fibril degradation (amyloidolysis). These data reveal that release of NETs, so far described to be elicited by pathogens, can also be triggered by amyloid fibrils. Moreover, the involvement of NETs in amyloidoses might be crucial for the production of toxic species derived from fibril fragmentation.

Nonspecific prion protein-nucleic acid interactions lead to different aggregates and cytotoxic species.

A misfolded form of the prion protein (PrP) is the primary culprit in mammalian prion diseases. It has been shown that nucleic acids catalyze the misfolding of cellular PrP into a scrapie-like conformer. It has also been observed that the interaction of PrP with nucleic acids is nonspecific and that the complex can be toxic to cultured cells. No direct correlation has yet been drawn between changes in PrP structure and toxicity due to nucleic acid binding. Here we asked whether different aggregation, stability, and toxicity effects are detected when nonrelated DNA sequences interact with recombinant PrP. Using spectroscopic techniques to analyze PrP tertiary and secondary structure and cellular assays to assess toxicity, we found that rPrP-DNA interactions lead to different aggregated species, depending on the sequence and size of the oligonucleotide tested. A 21-mer DNA sequence (D67) induced higher levels of aggregation and also dissimilar structural changes in rPrP, compared to binding to oligonucleotides with the same length and different nucleotide sequences or different GC contents. The rPrP-D67 complex induced significant cell dysfunction, which appears to be correlated with the biophysical properties of the complex. Although sequence specificity is not apparent for PrP-nucleic acid interactions, we believe that particular nucleic acid patterns, possibly related to GC content, oligonucleotide length, and structure, govern PrP recognition. Understanding the structural and cellular effects observed for PrP-nucleic acid complexes may shed light on the still mysterious pathology of the prion protein.

Mutant p53 aggregates into prion-like amyloid oligomers and fibrils: implications for cancer.

Over 50% of all human cancers lose p53 function. To evaluate the role of aggregation in cancer, we asked whether wild-type (WT) p53 and the hot-spot mutant R248Q could aggregate as amyloids under physiological conditions and whether the mutant could seed aggregation of the wild-type form. The central domains (p53C) of both constructs aggregated into a mixture of oligomers and fibrils. R248Q had a greater tendency to aggregate than WT p53. Full-length p53 aggregated into amyloid-like species that bound thioflavin T. The amyloid nature of the aggregates was demonstrated using x-ray diffraction, electron microscopy, FTIR, dynamic light scattering, cell viabilility assay, and anti-amyloid immunoassay. The x-ray diffraction pattern of the fibrillar aggregates was consistent with the typical conformation of cross ß-sheet amyloid fibers with reflexions of 4.7 Å and 10 Å. A seed of R248Q p53C amyloid oligomers and fibrils accelerated the aggregation of WT p53C, a behavior typical of a prion. The R248Q mutant co-localized with amyloid-like species in a breast cancer sample, which further supported its prion-like effect. A tumor cell line containing mutant p53 also revealed massive aggregation of p53 in the nucleus. We conclude that aggregation of p53 into a mixture of oligomers and fibrils sequestrates the native protein into an inactive conformation that is typical of a prionoid. This prion-like behavior of oncogenic p53 mutants provides an explanation for the negative dominance effect and may serve as a potential target for cancer therapy.

Mild Traumatic Brain Injury among the Geriatric Population.

Mild traumatic brain injury (TBI) is an unfortunately common occurrence in the elderly. With the growing population of older adults in the United States and globally, strategies that reduce the risk of becoming injured need to be developed, and diagnostic tools and treatments that may benefit this group need to be explored. Particular attention needs to be given to polypharmacy, drug interactions, the use of anticoagulants, safety issues in the living environment, elder abuse, and alcohol consumption. Low-mechanism falls should prompt health care providers to consider the possibility of head injury in elderly patients. Early and tailored management of our seniors following a mild TBI can provide them with the best possible quality of life. This review will discuss the current literature on mild TBI in the older adult, address gaps in research, and discuss the implications for future care of the older TBI patient.