9 research outputs found
Evaluation of Cuspidaria pulchra and its Isolated Compounds Against Schistosoma mansoni Adult Worms
The present study has investigated the chemical composition of the bioactive EtOAc fraction of Cuspidaria pulchra aerial parts, as well as its schistosomicidal activities against Schistosoma mansoni adult worms in vitro. To this end, the crude ethanol extract obtained from the aerial parts of C. pulchra (Bignoniaceae) was partitioned with n-hexane, EtOAc, and n-BuOH. The EtOAc fraction was purified by preparative HPLC, which afforded 3,4-dihydroxybenzaldehyde (1), p-coumaric acid (2), p-hydroxybenzoic acid (3), ursolic acid (4), and oleanolic acid (5). The bioassay results indicated that the crude ethanol extract and the EtOAc fraction at 100 µg/mL killed the adult schistosomes in vitro. Compounds 1 and 3 at 100 µm were only able to separate coupled S. mansoni adult worms
Case report: Urbanized non-human primates as sentinels for human zoonotic diseases: a case of acute fatal toxoplasmosis in a free-ranging marmoset in coinfection with yellow fever virus
Free-ranging non-human primates (NHP) can live in anthropized areas or urban environments in close contact with human populations. This condition can enable the emergence and transmission of high-impact zoonotic pathogens. For the first time, we detected a coinfection of the yellow fever (YF) virus with Toxoplasma gondii in a free-ranging NHP in a highly urbanized area of a metropolis in Brazil. Specifically, we observed this coinfection in a black-tufted marmoset found dead and taken for a necropsy by the local health surveillance service. After conducting an epidemiological investigation, characterizing the pathological features, and performing molecular assays, we confirmed that the marmoset developed an acute fatal infection caused by T. gondii in coinfection with a new YF virus South American-1 sub-lineage. As a result, we have raised concerns about the public health implications of these findings and discussed the importance of diagnosis and surveillance of zoonotic agents in urbanized NHPs. As competent hosts of zoonotic diseases such as YF and environmental sentinels for toxoplasmosis, NHPs play a crucial role in the One Health framework to predict and prevent the emergence of dangerous human pathogens
Poisoning by Nierembergia veitchii: Effects on vascular smooth muscle cells in the pathogenesis of enzootic calcinosis
Vascular mineralization is a hallmark of enzootic calcinosis. Histopathological, ultrastructural, and immunohistochemical investigations were performed on the external carotid arteries of seven sheep naturally poisoned by Nierembergia veitchii. Histologically, moderate to marked hyperplasia of the tunica intima was observed without mineralization. The tunica media exhibited mild to severe mineralization and osteochondroid metaplasia. Sheep with enzootic calcinosis showed arterial overexpression of osteopontin and tissue-nonspecific alkaline phosphatase and immunolabeling for osteonectin and osteocalcin in both intima and media layers of the tested arteries. The main ultrastructural finding in the tunica media was a marked phenotypic change of vascular smooth muscle cells from a contractile phenotype (VSMC-C) into a synthetic phenotype (VSMC-S). In the tunica media, VSMC-S produced matrix and extracellular vesicles, forming mineralizable granules associated with arterial mineralization. VSMC-S were also present in the tunica intima, but matrix and extracellular vesicles and mineralization were not observed. The absence of matrix and extracellular vesicles in the intimal hyperplasia, even in the presence of noncollagenous bone proteins, tissue-nonspecific alkaline phosphatase, and vitamin D receptors, reinforces the hypothesis that the presence of matrix and extracellular vesicles are crucial for the development of vascular mineralization in enzootic calcinosis. It is proposed that the two different VSMC-S phenotypes in calcinosis are due to the expression of at least two genetically different types of these cells induced by the action of 1,25(OH)2D3.Fil: Machado, Mizael. Instituto Nacional de InvestigaciĂłn Agropecuaria Inia Uruguay; UruguayFil: Castro, Márcio B.. Universidade do BrasĂlia; BrasilFil: Wilson, Tais M.. Universidade do BrasĂlia; BrasilFil: Gonçalves, Alexandra A. B.. Universidade do BrasĂlia; BrasilFil: Portiansky, Enrique Leo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Riet Correa, Franklin. Instituto Nacional de InvestigaciĂłn Agropecuaria Inia Uruguay; Uruguay. Universidade Federal da Bahia; BrasilFil: Barros, Severo S.. Universidade Federal de Santa Maria; Brasi
Synthesis of the Silaisocyanoacetylene Molecule
The hitherto elusive silaisocyanoacetylene molecule (HCCNSi)î—¸a
member of the silaisocyanide familyî—¸has been synthesized for
the first time through the reaction of the silicon nitride radical
(SiN) with acetylene (C<sub>2</sub>H<sub>2</sub>) in the gas phase
under single collision conditions. Compared to the isoelectronic reaction
of the cyano radical (CN) with acetylene, the replacement of the carbon
atom in the cyano group by an isovalent silicon atom has a pronounced
effect on the reactivity. Whereas the silicon nitride radical was
found to pass an entrance barrier and adds with the nitrogen atom
to the acetylene molecule, the cyano radical adds barrierlessly with
the carbon atom forming the HCCHÂ(NSi) and HCCHÂ(CN) intermediates,
respectively. These structures undergo hydrogen loss to form the linear
silaisocyanoacetylene (HCCNSi) and cyanoacetylene molecules (HCCCN),
respectively. Therefore, the isovalency of the silicon atom was found
to bear little resemblance with the carbon atom having a dramatic
effect not only on the reactivity, but also on the reaction mechanism,
thermochemistry, and chemical bonding of the isoelectronic silaisocyanoacetylene
and cyanoacetylene products, effectively reversing the thermodynamical
stability of the nitrile versus isonitrile and silanitrile versus
isosilanitrile isomer pairs
Hepato-pathological hallmarks for the surveillance of Yellow Fever in South American non-human primates
University of BrasĂlia. Graduate Program in Animal Science. Brasilia, DF, Brazil / Brazilian Ministry of Health. Brasilia, DF, BrazilBrazilian Ministry of Health. Brasilia, DF, BrazilBrazilian Ministry of Health. Brasilia, DF, BrazilBrazilian Ministry of Health. Brasilia, DF, BrazilThe University of Sydney. Sydney, New South Wales, AustraliaFundação Oswaldo Cruz. Rio de Janeiro, RJ, BrazilUniversidade do Estado do Pará. BelĂ©m, PA, BrazilMinistĂ©rio da SaĂşde. Secretaria de Vigilância em SaĂşde. Instituto Evandro Chagas. Ananindeua, PA, BrasilUniversidade do Estado do Pará. BelĂ©m, PA, BrazilUniversity of BrasĂlia. Graduate Program in Animal Science. Brasilia, DF, Brazil / University of BrasĂlia. Veterinary Pathology Laboratory. BrasĂlia, DF, BrazilUniversity of BrasĂlia. Graduate Program in Animal Science. Brasilia, DF, Brazil / University of BrasĂlia. Veterinary Pathology Laboratory. BrasĂlia, DF, BrazilUniversity of BrasĂlia. Graduate Program in Animal Science. Brasilia, DF, Brazil / University of BrasĂlia. Veterinary Pathology Laboratory. BrasĂlia, DF, BrazilUniversity of BrasĂlia. Graduate Program in Animal Science. Brasilia, DF, BrazilUniversity of BrasĂlia. Graduate Program in Animal Science. Brasilia, DF, Brazil / University of BrasĂlia. Veterinary Pathology Laboratory. BrasĂlia, DF, BrazilThe early detection and diagnosis of deaths in free-ranging non-human primates (NHPs) are key points for the surveillance of Yellow Fever (YF) in Brazil. The histopathological identification of infectious diseases remains very useful and reliable in the screening and detection of emerging zoonotic diseases such as YF. We surveyed data records and liver slides stained with hematoxylin and eosin from the Epizootics Surveillance Network to control YF, Ministry of Health of Brazil, to evaluate histopathological hallmarks for the diagnosis of the YF virus infection. We selected natural fatal cases in NHPs from the genera Alouatta spp., Callithrix spp., and Sapajus spp. with a positive immunohistochemical assay for YF in liver samples. Our findings showed the full-spectrum YF-associated hepatic lesions in all NHPs, but some histopathological findings differed in the distribution and intensity between the three genera. In our study, South American NHPs showed significant differences in the YF-associated hepatic histopathological features compared to fatal cases reported in humans
Clinicopathological discrepancies in the diagnoses of childhood causes of death in the CHAMPS network: An analysis of antemortem diagnostic inaccuracies
Introduction Determining aetiology of severe illness can be difficult, especially in settings with limited diagnostic resources, yet critical for providing life-saving care. Our objective was to describe the accuracy of antemortem clinical diagnoses in young children in high-mortality settings, compared with results of specific postmortem diagnoses obtained from Child Health and Mortality Prevention Surveillance (CHAMPS).Methods We analysed data collected during 2016–2022 from seven sites in Africa and South Asia. We compared antemortem clinical diagnoses from clinical records to a reference standard of postmortem diagnoses determined by expert panels at each site who reviewed the results of histopathological and microbiological testing of tissue, blood, and cerebrospinal fluid. We calculated test characteristics and 95% CIs of antemortem clinical diagnostic accuracy for the 10 most common causes of death. We classified diagnostic discrepancies as major and minor, per Goldman criteria later modified by Battle.Results CHAMPS enrolled 1454 deceased young children aged 1–59 months during the study period; 881 had available clinical records and were analysed. The median age at death was 11 months (IQR 4–21 months) and 47.3% (n=417) were female. We identified a clinicopathological discrepancy in 39.5% (n=348) of deaths; 82.3% of diagnostic errors were major. The sensitivity of clinician antemortem diagnosis ranged from 26% (95% CI 14.6% to 40.3%) for non-infectious respiratory diseases (eg, aspiration pneumonia, interstitial lung disease, etc) to 82.2% (95% CI 72.7% to 89.5%) for diarrhoeal diseases. Antemortem clinical diagnostic specificity ranged from 75.2% (95% CI 72.1% to 78.2%) for diarrhoeal diseases to 99.0% (95% CI 98.1% to 99.6%) for HIV.Conclusions Antemortem clinical diagnostic errors were common for young children who died in areas with high childhood mortality rates. To further reduce childhood mortality in resource-limited settings, there is an urgent need to improve antemortem diagnostic capability through advances in the availability of diagnostic testing and clinical skills