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1.
Polymers (Basel) ; 13(4)2021 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-33672475

RESUMO

Following the general aim of recapitulating the native mechanical properties of tissues and organs in vitro, the field of materials science and engineering has benefited from recent progress in developing compliant substrates with physical and chemical properties similar to those of biological materials. In particular, in the field of mechanobiology, soft hydrogels can now reproduce the precise range of stiffnesses of healthy and pathological tissues to study the mechanisms behind cell responses to mechanics. However, it was shown that biological tissues are not only elastic but also relax at different timescales. Cells can, indeed, perceive this dissipation and actually need it because it is a critical signal integrated with other signals to define adhesion, spreading and even more complicated functions. The mechanical characterization of hydrogels used in mechanobiology is, however, commonly limited to the elastic stiffness (Young's modulus) and this value is known to depend greatly on the measurement conditions that are rarely reported in great detail. Here, we report that a simple relaxation test performed under well-defined conditions can provide all the necessary information for characterizing soft materials mechanically, by fitting the dissipation behavior with a generalized Maxwell model (GMM). The simple method was validated using soft polyacrylamide hydrogels and proved to be very useful to readily unveil precise mechanical properties of gels that cells can sense and offer a set of characteristic values that can be compared with what is typically reported from microindentation tests.

2.
Biotechnol Bioeng ; 2021 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-33719058

RESUMO

Selenate (SeO4 2- ) reduction in hydrogen (H2 )-fed membrane biofilm reactors (H2 -MBfRs) was studied in combinations with other common electron acceptors. We employed H2 -MBfRs with two distinctly different conditions: R1, with ample electron-donor availability and acceptors SeO4 2- and sulfate (SO4 2- ), and R2, with electron-donor limitation and the presence of electron acceptors SeO4 2- , nitrate (NO3 - ), and SO4 2- . Even though H2 was available to reduce all input SeO4 2- and SO4 2- in R1, SeO4 2- reduction was preferred over SO4 2- reduction. In R2, co-reduction of NO3 - and SeO4 2- occurred, and SO4 2- reduction was mostly suppressed. Biofilms in all MBfRs had high microbial diversity that was influenced by the "rare biosphere" (RB), phylotypes with relative abundance less than 1%. While all MBfR biofilms had abundant members, such as Dechloromonas and Methyloversatilis, the bacterial communities were significantly different between R1 and R2. For R1, abundant genera were Methyloversatilis, Melioribacter, and Propionivibrio; for R2, abundant genera were Dechloromonas, Hydrogenophaga, Cystobacter, Methyloversatilis, and Thauera. Although changes in electron-acceptor or -donor loading altered the phylogenetic structure of the microbial communities, the biofilm communities were resilient in terms of SeO4 2- and NO3 - reductions, because interacting members of the RB had the capacity of respiring these electron acceptors.

5.
New Phytol ; 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33073860

RESUMO

That functional traits should affect individual performance and, in turn, determine fitness and population growth, is a foundational assumption of trait-based ecology. This assumption is, however, not supported by a strong empirical base. Here, we measured simultaneously two individual performance metrics (survival and growth), seven traits and 10 environmental properties for each of 3981 individuals of 205 species in a 50-ha stem-mapped subtropical forest. We then modelled survival/growth as a function of traits, environments and trait × environment interactions, and quantified their relative importance at both the species and individual levels. We found evidence of alternative functional designs and multiple performance peaks along environmental gradients, indicating the presence of complicated trait × environment interactions. However, such interactions were relatively unimportant in our site, which had relatively low environmental variations. Moreover, individual performance was not better predicted, and trait × environment interactions were not more likely detected, at the individual level than at the species level. Although the trait × environment interactions might be safely ignored in relatively homogeneous environments, we encourage future studies to test the interactive effects of traits and environments on individual performances and lifelong fitness at larger spatial scales or along experimentally manipulated environmental gradients.

6.
Omega (Westport) ; : 30222820947241, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32757692

RESUMO

Complicated grief is a significant health concern for older adults, resulting in significant psychological and physical morbidity. Elements of post traumatic stress disorder (PTSD) are often present in individuals with complicated grief. Accelerated Resolution Therapy (ART) is a brief form of psychotherapy that utilizes the techniques of imaginal exposure, rescripting of events, and lateral eye movements that may be useful in complicated grief with PTSD symptoms. Two cases where ART was used for complicated grief with PTSD are presented. Both individuals had attempted to come to terms with their loss through traditional grief therapy with an inadequate response and substantial residual grief symptoms. These cases illustrate how ART can be used to address CG and PTSD and describe situations where it may be appropriate. Clinical and research implications are also discussed.

7.
PLoS Pathog ; 16(7): e1008645, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32667960

RESUMO

Aspergillus fumigatus is an opportunistic fungal pathogen that secretes an array of immune-modulatory molecules, including secondary metabolites (SMs), which contribute to enhancing fungal fitness and growth within the mammalian host. Gliotoxin (GT) is a SM that interferes with the function and recruitment of innate immune cells, which are essential for eliminating A. fumigatus during invasive infections. We identified a C6 Zn cluster-type transcription factor (TF), subsequently named RglT, important for A. fumigatus oxidative stress resistance, GT biosynthesis and self-protection. RglT regulates the expression of several gli genes of the GT biosynthetic gene cluster, including the oxidoreductase-encoding gene gliT, by directly binding to their respective promoter regions. Subsequently, RglT was shown to be important for virulence in a chemotherapeutic murine model of invasive pulmonary aspergillosis (IPA). Homologues of RglT and GliT are present in eurotiomycete and sordariomycete fungi, including the non-GT-producing fungus A. nidulans, where a conservation of function was described. Phylogenetically informed model testing led to an evolutionary scenario in which the GliT-based resistance mechanism is ancestral and RglT-mediated regulation of GliT occurred subsequently. In conclusion, this work describes the function of a previously uncharacterised TF in oxidative stress resistance, GT biosynthesis and self-protection in both GT-producing and non-producing Aspergillus species.


Assuntos
Aspergilose , Aspergillus fumigatus/patogenicidade , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica/fisiologia , Gliotoxina/biossíntese , Fatores de Transcrição/metabolismo , Animais , Aspergilose/metabolismo , Aspergilose/microbiologia , Aspergillus fumigatus/metabolismo , Camundongos , Estresse Oxidativo/fisiologia , Virulência/fisiologia
8.
Int J Mol Sci ; 21(11)2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492823

RESUMO

Recent studies indicate that connexin hemichannels do not act as freely permeable non-selective pores, but they select permeants in an isoform-specific manner with cooperative, competitive and saturable kinetics. The aim of this study was to investigate whether the treatment with a mixture of IL-1ß plus TNF-α, a well-known pro-inflammatory condition that activates astroglial connexin 43 (Cx43) hemichannels, could alter their permeability to molecules. We found that IL-1ß plus TNF-α left-shifted the dye uptake rate vs. dye concentration relationship for Etd and 2-NBDG, but the opposite took place for DAPI or YO-PRO-1, whereas no alterations were observed for Prd. The latter modifications were accompanied of changes in Kd (Etd, DAPI, YO-PRO-1 or 2-NBDG) and Hill coefficients (Etd and YO-PRO-1), but not in alterations of Vmax. We speculate that IL-1ß plus TNF-α may distinctively affect the binding sites to permeants in astroglial Cx43 hemichannels rather than their number in the cell surface. Alternatively, IL-1ß plus TNF-α could induce the production of endogenous permeants that may favor or compete for in the pore-lining residues of Cx43 hemichannels. Future studies shall elucidate whether the differential ionic/molecule permeation of Cx43 hemichannels in astrocytes could impact their communication with neurons in the normal and inflamed nervous system.

9.
Rev. argent. neurocir ; 34(2): 140-144, jun. 2020. ilus
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1123385

RESUMO

El glioma del nervio óptico es una entidad de muy baja incidencia en pacientes adultos, lo cual impide tener suficiente información sobre historia natural y conducta terapéutica en este grupo etario. En el presente artículo comunicamos el caso de un paciente de 27 años de edad con compromiso agudo del nervio óptico izquierdo debido a hemorragia intra tumoral, forma de presentación muy poco común en este tipo de tumores. Se realizó la resección mediante un abordaje endoscópico transesfenoidal extendido, con preservación funcional de la vía óptica contralateral. La anatomía patológica confirmó astrocitoma pilocítico positivo para el rearreglo KIAA 1549-BRAF. y negativo para la mutación BRAF V600E. Teniendo en cuenta la histopatología y biología molecular en este caso, la estabilidad visual contralateral y la resección quirúrgica amplia, se decidió no realizar tratamiento adyuvante con radioterapia o quimioterapia. El objetivo de esta conducta fue evitar lesiones adicionales sobre el quiasma, nervio óptico contralateral y/o hipotálamo. Dada la escasa información existente en la literatura médica, el reporte de este caso podría contribuir con información adicional en el manejo y conducta terapéutica de este tipo de lesiones.


The optic nerve glioma is a very uncommon entity in adult patients, with little information about its natural history and therapeutical management. We report the case of a 27-year-old patient with acute involvement of the left optic nerve due to intratumoral hemorrhage, a very uncommon form of presentation in this type of tumor. Resection was performed using an extended transsphenoidal endoscopic approach, with functional preservation of the contralateral optic pathway. The histopathology confirmed positive pilocytic astrocytoma with KIAA 1549-BRAF rearrangement and without BRAF V600E mutation. Considering the histopathology and molecular biology, the contralateral visual stability and the wide surgical resection, it was decided not to perform further treatment. The purpose of this decision was to avoid additional damage to the chiasm, contralateral optic nerve and/or hypothalamus. Given the limited data available in medical literature, the report of this case could contribute with additional information on the management and therapeutic approach of this type of tumors


Assuntos
Humanos , Masculino , Glioma do Nervo Óptico , Nervo Óptico , Endoscopia , Hemorragia
10.
Antibiotics (Basel) ; 9(4)2020 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-32340386

RESUMO

Acinetobacter baumannii (named in honor of the American bacteriologists Paul and Linda Baumann) is a Gram-negative, multidrug-resistant (MDR) pathogen that causes nosocomial infections, especially in intensive care units (ICUs) and immunocompromised patients with central venous catheters. A. baumannii has developed a broad spectrum of antimicrobial resistance, associated with a higher mortality rate among infected patients compared with other non-baumannii species. In terms of clinical impact, resistant strains are associated with increases in both in-hospital length of stay and mortality. A. baumannii can cause a variety of infections; most involve the respiratory tract, especially ventilator-associated pneumonia, but bacteremia and skin wound infections have also been reported, the latter of which has been prominently observed in the context of war-related trauma. Cases of meningitis associated with A. baumannii have been documented. The most common risk factor for the acquisition of MDR A baumannii is previous antibiotic use, following by mechanical ventilation, length of ICU/hospital stay, severity of illness, and use of medical devices. Current efforts focus on addressing all the antimicrobial resistance mechanisms described in A. baumannii, with the objective of identifying the most promising therapeutic scheme. Bacteriophage- and artilysin-based therapeutic approaches have been described as effective, but further research into their clinical use is required.

11.
J. negat. no posit. results ; 5(3): 295-306, mar. 2020. graf
Artigo em Espanhol | IBECS | ID: ibc-194038

RESUMO

INTRODUCCIÓN: De acuerdo a la organización de las Naciones Unidas para la Alimentación y la Agricultura (FAO), la alimentación humana se define como un proceso voluntario consistente y educable. OBJETIVO: Determinar hábitos alimenticios y su impacto en el rendimiento académico de los estudiantes de la Licenciatura en Farmacia del ICSa. METODOLOGÍA: Se realizó un estudio observacional transversal. Se adaptó la encuesta sobre alimentación saludable de la fundación MAPFRE y el muestreo fue no probabilístico. RESULTADOS: Se aplicaron 102 encuestas, predomino el sexo femenino, con un promedio de edad de 20(±1) años. Cerca del 50%, mencionó traer alimentos de su casa y tener el hábito de desayunar, sin embargo, menos de la mitad de la muestra consume al menos una fruta y/o verdura al día. Un 76% considera que su alimentación si impacta en su rendimiento académico. CONCLUSIONES: Es importante concienciar a los estudiantes sobre la manera correcta de alimentarse y el impacto en su rendimiento académico, así como fomentar estilos de vida saludables y brindarles información necesaria y correcta para seleccionar adecuadamente sus alimentos y bebidas, de lo contrario esa selección de alimentos será no positiva, es decir, negativa


INTRODUCTION: According to the United Nations Food and Agriculture Organization (FAO), human food is defined as a consistent and educatable voluntary process. OBJECTIVE: To identify the impact of eating habits on the academic performance of students of the ICSa Pharmacy degree. METHODOLOGY: A cross-sectional, observational and prospective study was carried out. The MAPFRE Foundation's Healthy Eating survey was adapted and the sampling was non-probabilistic. RESULTS: We applied 102 surveys, predominated the female sex, with an average age of 20 (± 1) years. About 50%, he mentioned bringing food from his home and having the habit of having breakfast, however, less than half of the sample consumes at least one fruit and/or vegetable a day. A 76% believe their food if it impacts their academic performance. CONCLUSIONS: It is important to make students aware of the correct way to eat and the impact on their academic performance, as well as to promote healthy lifestyles and provide them with necessary and correct information to properly select their food and drinks, otherwise that food selection will not be positive, that is, negative


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Comportamento Alimentar/psicologia , Desempenho Acadêmico/estatística & dados numéricos , Avaliação Nutricional , Dieta Saudável/estatística & dados numéricos , Estudantes de Farmácia/estatística & dados numéricos , Estudos Transversais , Inquéritos Nutricionais/estatística & dados numéricos , Educação Alimentar e Nutricional , Prevenção de Doenças
12.
J Nat Prod ; 83(3): 610-616, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32073851

RESUMO

Social insects establish complex interactions with microorganisms, some of which play defensive roles in colony protection. The important role of pollinators such as the stingless bee Melipona scutellaris in nature encouraged us to pursue efforts to study its associated microbiota. Here we describe the discovery of two novel cyclic hexadepsipeptides, meliponamycin A (1) and meliponamycin B (2), from Streptomyces sp. ICBG1318 isolated from M. scutellaris nurse bees. Their structures were established by interpretation of NMR and MS data, and the absolute configuration of the constituent amino acids was determined by the advanced Marfey's method. Compounds 1 and 2 showed strong activity against the entomopathogen Paenibacillus larvae and human pathogens Staphylococcus aureus and Leishmania infantum.

13.
Acta Trop ; 204: 105360, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32001248

RESUMO

In Venezuela, areas endemic for schistosomiasis are of low transmission, with low parasite loads. Immunological tests often lack specificity and cannot differentiate past from present infections. Molecular tests are an alternative, although validation studies in endemic areas are needed. The aim of this study was to determine the performance of parasitological, immunological and molecular tests for the diagnosis of Schistosoma mansoni infection in low-transmission settings. A cross-sectional study was carried out in a rural community located in a schistosomiasis-endemic area of Venezuela to determine the prevalence and diagnostic performance of the Kato-Katz (KK) technique, Circumoval Precipitin Test (COPT), ELISA based on soluble egg antigen (ELISA-SEA) with and without treatment with sodium metaperiodate (ELISA-SEA-SMP), and PCR for amplification of the 121 bp highly repeated sequence of Schistosoma mansoni in faeces, urine and serum samples. The highest prevalence rates were obtained with ELISA-SEA (38.7%), COPT (33.3%), ELISA-SEA-SMP (31.5%), PCR on faeces (21.6%), and KK (17.1%), whereas PCR-based prevalence in urine was 6.2% and no positivity was detected in serum samples. Results showed that ELISA-SEA is the best method for the diagnosis of both current and former infections and that PCR on faeces is the best method for detecting recent transmission. The use of different tests that complement one another also allowed for a better diagnosis of Schistosoma mansoni infection, revealing a relatively high prevalence (33.8%) of schistosomiasis in a community of low transmission.


Assuntos
Antígenos de Helmintos/imunologia , Schistosoma mansoni/imunologia , Esquistossomose mansoni/epidemiologia , Adolescente , Adulto , Fatores Etários , Animais , Criança , Estudos Transversais , Ensaio de Imunoadsorção Enzimática , Fezes/parasitologia , Feminino , Humanos , Masculino , Carga Parasitária , Prevalência , Esquistossomose mansoni/diagnóstico , Sensibilidade e Especificidade , Venezuela/epidemiologia , Adulto Jovem
14.
Am J Hosp Palliat Care ; 37(10): 791-799, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31960705

RESUMO

BACKGROUND AND OBJECTIVES: Complicated grief (CG) is severe, prolonged (>12 months) grieving. Complicated grief disproportionately affects older adults and is associated with negative physical/psychological effects. Although treatment options exist, those which do are time-intensive. We report on a randomized clinical trial (RCT) which examined whether accelerated resolution therapy (ART), a novel mind-body therapy, is effective in treating CG, post-traumatic stress disorder (PTSD), and depression among hospice informal caregivers. RESEARCH DESIGN AND METHODS: Prospective 2 group, wait-listed RCT. All participants were scheduled to receive 4 ART sessions. INCLUSION: ≥60 years, inventory of CG >25, and PTSD checklist for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition >33 or Psychiatric Diagnostic Screen Questionnaire PTSD subscale >5. EXCLUSION: Major psychiatric disorder, other current psychotherapy treatment. Depression was measured by the Center for Epidemiologic Studies Depression. RESULTS: Mean (standard deviation [SD]) age of 54 participants was 68.7 (7.2) years, 85% female, and 93% white. Participants assigned to ART reported significantly greater mean (SD) CG reduction (-22.8 [10.3]) versus Wait-list participants (-4.3 [6.0]). Within-participant effect sizes (ESs) for change from baseline to 8-week post-treatment were CG (ES = 1.96 (95% confidence interval [CI]: 1.45-2.47; P < .0001), PTSD (ES = 2.40 [95% CI: 1.79-3.00]; P < .0001), depression (ES = 1.63 [95% CI: 1.18-2.08; P < .0001). Treatment effects did not substantially differ by baseline symptom levels. DISCUSSION AND IMPLICATIONS: Results suggests that ART presents an effective and less time-intensive intervention for CG in older adults. However, it should undergo further effectiveness testing in a larger, more diverse clinical trial with a focus on determining physiological or behavioral mechanisms of action.

15.
Transbound Emerg Dis ; 67(3): 1198-1212, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31834976

RESUMO

Infectious bursal disease virus (IBDV) is an economically relevant and widespread pathogen that produces immunosuppression in young chickens. IBDV is genetically classified into seven genogroups (G1-G7), where the traditional classic, variant and very virulent strains correspond to G1, G2 and G3, respectively. The G4 strains, also known as 'distinct' (dIBDV), have recently acquired increased relevance because of their prevalence and notorious impair to the poultry industry in South America. Here, worldwide dIBDV strains were studied using phylogenetic and phylodynamic approaches. The phylogenetic analyses performed using partial and complete sequences of both viral segments (A and B) consistently clustered the dIBDV strains in a monophyletic group. The analyses of the VP5, polyprotein and VP1 coding regions identified amino acid residues that act as markers for the identification of the entire dIBDV group or different sub-populations. The phylodynamic analyses performed using the hypervariable region of VP2 indicated that the dIBDV strains emerged in the early 1930s in Eastern Europe, shortly after the emergence of classic strains (1927) and before variant (1949) and very virulent strains (1967). The analysis of the migration routes indicated that after its emergence, the dIBDV strains spread to Eastern Asia around 1959, to Brazil around 1963, and to Argentina around 1990. These inter-continental migrations resulted in three sub-populations that are currently represented by strains from (a) Brazil, (b) Eastern Asia and Canada, and (c) Eastern Europe, Argentina and Uruguay. Taken together, our results highlight the complex evolutionary history of IBDV and the importance of new phylodynamic data to unravel and nearly follow the different evolutionary pathways taken by this important poultry pathogen.


Assuntos
Evolução Biológica , Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/fisiologia , Filogenia , Infecções por Birnaviridae/virologia , Vírus da Doença Infecciosa da Bursa/classificação , Vírus da Doença Infecciosa da Bursa/genética , Proteínas Virais/análise
16.
PLoS. Pathog., v. 16 n. 7, e1008645, jul. 2020
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP | ID: bud-3105

RESUMO

Aspergillus fumigatus is an opportunistic fungal pathogen that secretes an array of immune-modulatory molecules, including secondary metabolites (SMs), which contribute to enhancing fungal fitness and growth within the mammalian host. Gliotoxin (GT) is a SM that interferes with the function and recruitment of innate immune cells, which are essential for eliminating A. fumigatus during invasive infections. We identified a C6 Zn cluster-type transcription factor (TF), subsequently named RglT, important for A. fumigatus oxidative stress resistance, GT biosynthesis and self-protection. RglT regulates the expression of several gli genes of the GT biosynthetic gene cluster, including the oxidoreductase-encoding gene gliT, by directly binding to their respective promoter regions. Subsequently, RglT was shown to be important for virulence in a chemotherapeutic murine model of invasive pulmonary aspergillosis (IPA). Homologues of RglT and GliT are present in eurotiomycete and sordariomycete fungi, including the non-GT-producing fungus A. nidulans, where a conservation of function was described. Phylogenetically informed model testing led to an evolutionary scenario in which the GliT-based resistance mechanism is ancestral and RglT-mediated regulation of GliT occurred subsequently. In conclusion, this work describes the function of a previously uncharacterised TF in oxidative stress resistance, GT biosynthesis and self-protection in both GT-producing and non-producing Aspergillus species.

17.
Medicina (B Aires) ; 79(6): 453-460, 2019.
Artigo em Espanhol | MEDLINE | ID: mdl-31829947

RESUMO

Stereotactic radiosurgery has shown effectiveness in the multimodal treatment of skull base tumors, however it is suggested that in radiobiologically sensitive areas (eg. optic nerves and brainstem) the radiation dose should be reduced due to radiotoxic effects. To avoid the consequent therapeutic ineffectiveness, a recently implemented alternative is multisession radiosurgery (RCH). We retrospectively analyzed a series of patients with skull base tumors, in order to evaluate the treatment with RCH through tumor control in the post-treatment images. Age, sex, tumor histology, tumor volume, radiation protocol, pre-treatment Karnofsky performance status (KPS) previous neurosurgery and radiant treatment were also evaluated. Eighty-four patients were treated between January 2009 and January 2017. The median age was 51.5 years; females: 53.6%. There was a 92.7% non-progression after treatment, with a median follow-up time of 36 months. Treated tumors were mainly pituitary adenomas, acoustic schwannomas, and skull base meningiomas. Most of the patients received a 5-day fractionated treatment scheme, with a total dose of 25 Gy. No clinically manifest late radiotoxicity was observed. In the multivariate analysis, a high pre-treatment KPS was significantly associated with tumor non-progression. In our series, the high incidence of tumor non-progression would indicate that treatment with RCH could be a therapeutic option in some cases of skull-base tumors, mainly recurrences or tumor residuals of pituitary adenomas, neurinomas and meningiomas.


Assuntos
Radiocirurgia/métodos , Neoplasias da Base do Crânio/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Avaliação de Estado de Karnofsky , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Doses de Radiação , Reprodutibilidade dos Testes , Estudos Retrospectivos , Neoplasias da Base do Crânio/diagnóstico por imagem , Neoplasias da Base do Crânio/patologia , Fatores de Tempo , Carga Tumoral
18.
Medicina (B.Aires) ; 79(6): 453-460, dic. 2019. ilus, graf, tab
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1056753

RESUMO

La radiocirugía estereotáctica ha demostrado efectividad en el tratamiento multimodal de los tumores de base de cráneo, de todas maneras se sugiere que en áreas radiobioló;gicamente sensibles (ej. nervios ó;pticos y tronco cerebral) la dosis radiante debería reducirse por los efectos radiotó;xicos. Para evitar la ineficacia terapó;©utica, una alternativa recientemente implementada es la radiocirugía multisesió;n (RCH). Se analizó; en forma retrospectiva una serie de tumores de base de cráneo, con el fin de evaluar el tratamiento con RCH a travó;©s del control tumoral en las imágenes post-tratamiento. Se evaluó; tambín edad, sexo, histología tumoral, volumen tumoral, protocolo radiante, Karnofsky performance status (KPS) pre-tratamiento y neurocirugía y tratamiento radiante previos. Fueron tratados 84 pacientes entre enero 2009 y enero 2017. La mediana de edad fue 51.5 aó;±os; sexo femenino: 53.6%. Hubo un 92.7% de no-progresió;n luego del tratamiento, con una mediana de tiempo de seguimiento de 36 meses. Los tumores tratados fueron principalmente adenomas hipofisarios, neurinomas del acó;ºstico, y meningiomas de base de cráneo. La mayoría de los pacientes recibió; un esquema de tratamiento fraccionado de 5 días, con una dosis total de 25 Gy. No se observó; radiotoxicidad tardía clínicamente manifiesta. En el análisis multivariado, un KPS alto pre-tratamiento fue significativamente asociado a la no-progresió;n tumoral. En esta serie, la alta incidencia de no-progresió;n tumoral indicaría que el tratamiento con RCH podría ser una opció;n terapó;©utica en algunos casos de tumores de base de cráneo, principalmente recurrencias o remanencias tumorales de adenomas hipofisarios, neurinomas y meningiomas.


Stereotactic radiosurgery has shown effectiveness in the multimodal treatment of skull base tumors, however it is suggested that in radiobiologically sensitive areas (eg. optic nerves and brainstem) the radiation dose should be reduced due to radiotoxic effects. To avoid the consequent therapeutic ineffectiveness, a recently implemented alternative is multisession radiosurgery (RCH). We retrospectively analyzed a series of patients with skull base tumors, in order to evaluate the treatment with RCH through tumor control in the post-treatment images. Age, sex, tumor histology, tumor volume, radiation protocol, pre-treatment Karnofsky performance status (KPS) previous neurosurgery and radiant treatment were also evaluated. Eighty-four patients were treated between January 2009 and January 2017. The median age was 51.5 years; females: 53.6%. There was a 92.7% non-progression after treatment, with a median follow-up time of 36 months. Treated tumors were mainly pituitary adenomas, acoustic schwannomas, and skull base meningiomas. Most of the patients received a 5-day fractionated treatment scheme, with a total dose of 25 Gy. No clinically manifest late radiotoxicity was observed. In the multivariate analysis, a high pre-treatment KPS was significantly associated with tumor non-progression. In our series, the high incidence of tumor non-progression would indicate that treatment with RCH could be a therapeutic option in some cases of skull-base tumors, mainly recurrences or tumor residuals of pituitary adenomas, neurinomas and meningiomas.

19.
Front Oncol ; 9: 1143, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31737570

RESUMO

Tumor cells must generate sufficient ATP and biosynthetic precursors in order to maintain cell proliferation requirements. Otto Warburg showed that tumor cells uptake high amounts of glucose producing large volumes of lactate even in the presence of oxygen, this process is known as "Warburg effect or aerobic glycolysis." As a consequence of such amounts of lactate there is an acidification of the extracellular pH in tumor microenvironment, ranging between 6.0 and 6.5. This acidosis favors processes such as metastasis, angiogenesis and more importantly, immunosuppression, which has been associated to a worse clinical prognosis. Thus, lactate should be thought as an important oncometabolite in the metabolic reprogramming of cancer. In this review, we summarized the role of lactate in regulating metabolic microenvironment of cancer and discuss its relevance in the up-regulation of the enzymes lactate dehydrogenase (LDH) and monocarboxilate transporters (MCTs) in tumors. The goal of this review is to expose that lactate is not only a secondary product of cellular metabolic waste of tumor cells, but also a key molecule involved in carcinogenesis as well as in tumor immune evasion. Finally, the possible targeting of lactate production in cancer treatment is discussed.

20.
PeerJ ; 7: e7962, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31667018

RESUMO

Background: The canine transmissible venereal tumor (CTVT) or Sticker's sarcoma is a neoplastic disease affecting dogs. This disease is presented as a tumoral mass in the genital organs of both, male and female individuals. Up to date, there is no clear evidence indicating a viral agent as the causative mediator for CTVT development. Purpose: The present work aims to analyze 21 samples from canines with CTVT for molecular identification of Papillomavirus DNA sequences. In addition, microbiological analysis, cytologic and histopathologic evaluations were also performed. Results: All patients showed no biochemical and microbiological alterations. Molecular analysis demonstrated the viral DNA presence in the samples using different primer sets. The MY primers amplified a 450 bp band in seven out of 21 samples (33%). The PVF and Fap64 primer set, targeting the L1 sequence of Canine Papillomavirus (CPV), showed positivity in 16 out of 21 samples (76%). Conclusion: These results support the possible causative association between CPV and CTVT; nevertheless, additional studies are required to uphold such statement. This work presents evidence indicating that a viral agent might be involved in the pathogenesis of CTVT and set the bases for a better understanding of the CTVT pathobiology.

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