THE IMMUNOLOGY OF EXPERIMENTAL CHAGAS' DISEASE : III. REJECTION OF ALLOGENEIC HEART CELLS IN VITRO

Experiments that consisted of incubation of Trypanosoma cruzi-sensitized lymphocytes derived from chronically infected rabbits and from rabbits repeatedly immunized with a small particle or membrane fraction derived from homogenates of T. cruzi forms, showed destruction of allogeneic, parasitized and nonparasitized heart cells in vitro. Mononuclear cells collected from peripheral blood were incubated for 1 h at 37°C to isolate the lymphocytes. Following incubation, over 99% of the cells in the supernate were lymphocytes, which were utilized in these experiments. At the start of these experiments, 70–80% of the sensitized lymphocytes were unattached, small and round, with sparse filipodia. In the ensuing hours, marked heart cell destruction, similar to that seen in an active lesion when lymphocytes invade heart tissue, were observed. After 18 h incubation, about 65–70% of the lymphocytes were attached, larger, and rough surfaced. Inhibition of monocyte migration tests, each in the presence of the antigens of subcellular fractions of T. cruzi organisms and of allogeneic heart myofibers, indicated the presence of a cross-reacting antigen common to both the parasite and the heart in the small particle or membrane fractions. The particulate antigens of the 30,000 g, 35-min fraction of heart muscle gave rise to inhibition of monocyte migration as did the counterpart fraction derived from T. cruzi organisms. The destruction of nonparasitized target heart cells by T. cruzi-sensitized lymphocytes is an in vitro model of the chronic myocarditis of Chagas' disease, and the recognition of cross-reactive antigens of the host cell by T. cruzi-sensitized lymphocytes is believed to be the pathogenic basis for subsequent tissue injury in the chronic phase of this disease

The Neuroprotective Disease-Modifying Potential of Psychotropics in Parkinson's Disease

Neuroprotective treatments in Parkinson's disease (PD) have remained elusive. Psychotropics are commonly prescribed in PD without regard to their pathobiological effects. The authors investigated the effects of psychotropics on pathobiological proteins, proteasomal activity, mitochondrial functions, apoptosis, neuroinflammation, trophic factors, stem cells, and neurogenesis. Only findings replicated in at least 2 studies were considered for these actions. Additionally, PD-related gene transcription, animal model, and human neuroprotective clinical trial data were reviewed. Results indicate that, from a PD pathobiology perspective, the safest drugs (i.e., drugs least likely to promote cellular neurodegenerative mechanisms balanced against their likelihood of promoting neuroprotective mechanisms) include pramipexole, valproate, lithium, desipramine, escitalopram, and dextromethorphan. Fluoxetine favorably affects transcription of multiple genes (e.g., MAPT, GBA, CCDC62, HIP1R), although it and desipramine reduced MPTP mouse survival. Haloperidol is best avoided. The most promising neuroprotective investigative priorities will involve disease-modifying trials of the safest agents alone or in combination to capture salutary effects on H3 histone deacetylase, gene transcription, glycogen synthase kinase-3, α-synuclein, reactive oxygen species (ROS), reactive nitrogen species (RNS), apoptosis, inflammation, and trophic factors including GDNF and BDNF

Idade e crescimento do boca-negra, Helicolenus dactylopterus dactylopterus (Delaroche, 1809) dos Açores

A idade e o crescimento de boca-negra, Helicolenus dactylopterus dactylopterus (Delaroche, 1809), foram estudadas pela observação dos otólitos (sagittae) esquerdos inteiros (n = 401) obtidos de exemplares (14-47 cm de comprimento total) capturados em águas Açoreanas. Enumeraram-se os anéis opacos observados na face anti-sulcal dos otólitos. Os intervalos de idades foram 3-14 anos para machos e 3-12 anos para fêmeas. Estimaram-se e compararam-se os parâmetros da equação de crescimento de von Bertalanffy, entre sexos e entre métodos (leitura directa de otólitos, retrocálculo e análise de distribuições de frequências de comprimentos). Não se verificaram diferenças importantes. Os resultados são diferentes da literatura publicada para a região. Discutem-se as causas e implicações dos resultados obtidos.ABSTRACT: Bluemouth, Helicolenus dactylopterus dactylopterus (Delaroche, 1809), age and growth were studied by whole-view examination of left sagittae (n = 401) obtained from specimens (14-47 cm in total length) caught off the Azores. Opaque rings observed on the anti-sulcal surface of sagittae were enumerated as age estimates. Ages ranged from 3 to 14 years in males and 3 to 12 years in females. The von Bertalanffy growth equation was fitted to average length at age data, and compared between sexes and methods (direct examination of otoliths, backcalculation and length-frequency analysis). No important differences in growth between sexes were found. Results are different from published literature for the region. The causes and implications of the results are discussed

Can Eucalyptus plantations influence the distribution range of mesocarnivores?

Context The expansion of exotic plantations can impose conservation challenges on wildlife, and the Iberian Peninsula has one of the widest planted areas of exotic Eucalyptus sp. in Europe. Since mesocarnivores are pivotal elements of ecosystems’ functioning and Eucalyptus have been modifying the Portuguese landscape context in the last half century, it is crucial to understand how these systems may affect carnivores’ range. Objectives We aim to identify the drivers of five mesocarnivores’ distribution in Portugal (e.g., land-cover, ecogeographic predictors, mammal prey availability) and understand the influence of Eucalyptus plantations in their distribution range. Methods Using generalized linear models, we modelled the distribution range of mesocarnivores. The initial dataset was randomly split for model training and validation, and the multicollinearity between the predictors was tested. Then, we examined the potential relationship between the Eucalyptus plantations area and the predicted probability presence of each species. Results We detected species-specific patterns explained by different drivers, including climatic, land cover and mammal prey related ones. Furthermore, in areas of Eucalyptus plantations, the probability of occurrence of most Portuguese mesocarnivores is lower: red fox,stone marten,European badger, and Egyptian mongoose. Conclusions Managers must take action to adapt their management to promote native forest patches within plantation, and allow the development of some understory within stands, to improve this plantation’s permeability to mesocarnivores. This will increase the spatial heterogeneity and enhance resource availability, reducing the constraints that plantations might have on the range of mesocarnivores in Portugal.info:eu-repo/semantics/publishedVersio

Early psychiatric morbidity in a Brazilian sample of acute ischemic stroke patients

OBJECTIVE: Stroke is a major public health problem worldwide, and its neuropsychiatric sequelae are frequent and disabling. Furthermore, there is evidence that these sequelae impair recovery. Brazil has the highest stroke rates in Latin America, but data on the frequency of neuropsychiatric disorders in these patients are scarce. This study aimed to identify mental disorders among in-hospital patients with acute ischemic stroke. METHODS: The Mini International Neuropsychiatric Interview-Plus (MINI-Plus) was applied to 60 patients during the first week of hospitalization. RESULTS: Psychiatric disorders were diagnosed in 55% of the patients. A wide range of neuropsychiatric disorders have been identified, mainly mood and anxiety disorders. Specifically, we identified major depression (26.7%), alcohol abuse or dependence (11.7%), specific phobia (8.3%), generalized anxiety disorder (6.7%), psychosis (5.0%), social phobia (3.3%), adjustment disorder (3.3%) and panic disorder (1.7%). CONCLUSION: Psychiatric comorbidity should be evaluated as part of the rehabilitation of stroke patients and should be carefully examined by physicians

Accelerated Epigenetic Aging in Older Adults With HIV Disease: Associations With Serostatus, HIV Clinical Factors, and Health Literacy

The prevalence of older persons with HIV (PWH) disease has increased considerably in the last 20 years, but our understanding of biological factors of aging and their clinical correlates among PWH remains limited. Study participants were 149 persons aged 50 and older, including 107 PWH and 42 seronegatives. All participants completed a blood draw, research medical evaluation, structured psychiatric interview, neurocognitive assessment, questionnaires, and measures of health literacy. Four epigenetic clocks were generated from stored blood samples using standardized laboratory methods. In regression models adjusting for sex and smoking status, PWH had significantly higher epigenetic aging acceleration values than seronegatives on all four indicators. Within the PWH sample, higher levels of epigenetic aging acceleration were moderately associated with lower current CD4 count, AIDS diagnoses, higher scores on the Veterans Aging Cohort Study Index, and lower telomere values. Higher epigenetic aging acceleration indices were also associated with lower health literacy among PWH. PWH experience accelerated aging as measured by a series of epigenetic clocks, which may be linked to immune compromise and risk of all-cause mortality. Health literacy may be a modifiable target for mitigating the risk of accelerated aging among older PWH

Apathy Is Not Associated With a Panel of Biomarkers in Older Adults With HIV Disease

OBJECTIVE: Apathy is prevalent in HIV disease and can significantly impact personal well-being; however, little is known about its neurobiological substrates in persons with HIV (PWH) disease. METHODS: This cross-sectional, correlational study examined the association between apathy and several plasma biomarkers (tumor necrosis factor alpha, kynurenine, tryptophan, quinolinic acid, brain-derived neurotrophic factor, glial fibrillary acidic protein, neurofilament light chain, and phosphorylated tau at position threonine 181) in 109 PWH and 30 seronegative participants ages 50 and older. Apathy was measured with a composite score derived from subscales of the Frontal Systems Behavior Scale and the Profile of Mood States. RESULTS: Multiple regressions showed that PWH had significantly greater severity of apathy symptoms, independent of both data-driven and conceptually-based covariates. Pairwise correlations in the PWH sample indicated that apathy was not significantly associated with any of the measured biomarkers and all of the effect sizes were small. CONCLUSION: Findings suggest that apathy is not strongly associated with peripheral biomarkers of inflammation, neurotrophic support, or neurodegeneration in older PWH. Limitations of this study include the cross-sectional design, the use of self-report measures of apathy, and low rates of viremia. Longitudinal studies in more representative samples of PWH that include a more comprehensive panel of fluid biomarkers, informant and behavioral indicators of apathy, and relevant psychosocial factors might help to further clarify the neurobiological substrates of this complex neuropsychiatric phenomenon

Piolhos hematófagos podem disseminar infecção pelo Trypanosoma cruzi em babuínos

Trypanosoma cruzi (Schyzotrypanum, Chagas, 1909), and Chagas disease are endemic in captive-reared baboons at the Southwest Foundation for Biomedical Research, San Antonio, Texas. We obtained PCR amplification products from DNA extracted from sucking lice collected from the hair and skin of T. cruzi-infected baboons, with specific nested sets of primers for the protozoan kinetoplast DNA, and nuclear DNA. These products were hybridized to their complementary internal sequences. Selected sequences were cloned and sequencing established the presence of T. cruzi nuclear DNA, and minicircle kDNA. Competitive PCR with a kDNA set of primers determined the quantity of approximately 23.9 ± 18.2 T. cruzi per louse. This finding suggests that the louse may be a vector incidentally contributing to the dissemination of T. cruzi infection in the baboon colony.As infecções pelo Trypanosoma cruzi e a doença de Chagas são endêmicas em babuínos (Papio hamadryas) reproduzidos em cativeiro na Southwest Foundation for Biomedical Research, em Santo Antonio, Texas. Nós obtivemos produtos de amplificação por PCR do DNA extraído de piolhos colhidos do cabelo e da pele de babuínos chagásicos, com primers aneladores específicos para DNAs nuclear e de cinetoplasto do protozoário. Esses produtos foram hibridizados com suas respectivas seqüências internas complementares. Seqüências selecionadas foram clonadas e o sequenciamento demonstrou a presença de DNA nuclear de T. cruzi, e de minicírculo de kDNA. A PCR competitiva com primers de kDNA determinou a quantidade de aproximadamente 23.9 ± 18.2 T. cruzi por piolho. Este achado sugere que o piolho pode ser um vetor contribuindo para a disseminação de T. cruzi na colônia de babuínos

Antibacterial activity of crude methanolic extract and fractions obtained from Larrea tridentata leaves

Larrea tridentata (Zygophyllaceae), commonly known as creosote bush, is a plant that grows in semiarid areas of Southwestern United States and Northern Mexico and was traditionally used for medicinal purposes. This plantis a notable source of natural compounds with approximately 50% of the leaves (dry weight) being extractable matter. This study was designed to evaluate the antibacterial activity of the crude methanolic extract (CME) and fractions [hexane (H), dicloromethane (DCM), ethyl acetate (EA) and ethanol (Et)] obtained from Larrea tridentata leaves. A preliminary study of the antibacterial activity was performed using the agar diffusion method against six strains of Gram-positive and Gram-negative bacteria. The micro-dilution method was applied for the determination of the minimal inhibitory concentration (MIC) of selected bacteria strains. HPLC analyses of tested samples were also carried out. The antibacterial activity of the tested samples was noticeable more effective inhibiting the growth of Gram-positive bacteria comparing with Gram-negative bacteria, by the CME, DCM and EA fractions. EA fraction showed the highest antibacterial activity against methicillin-resistant Staphylococcus aureus isolated from secretion; with a MIC value (31.3 μg/mL) lower than the reference antibiotic tetracycline (64 μg/mL). Low MIC values (62.5 μg/mL) were also obtained for crude methanolic extract and DCM fraction compared to tetracycline. The highest concentrations of quercetin, kaempferol and nordihydroguaiaretic acid were observed in CME (8.67, 21.52 and 35.75 mg/g, respectively); nevertheless, EA fraction also showed considerable levels of these compounds compared with the remaining fractions. Other compounds were observed in the HPLC chromatograms and further studies are needed in order to identify them. The antibacterial activity of the samples studied might be explained by the synergistic or additive effects of several components rather than arising from a single compound. In conclusion, EA fraction showed the most promising results against the bacterial strain methicillin-resistant Staphylococcus aureus, which represents an important step for the search and development of a new antibacterial agent. Nevertheless, further toxicological and pharmacological studies are needed in order to confirm the hypothesis of using phytochemicals from Larrea tridentata leaves