Publications by authors named "Helena C Castro"

Article Synopsis
  • This study focuses on creating and testing 6-aminated 1,4-benzoquinones (6-AQs) for their ability to combat seven resistant pathogens.
  • The 6-AQs were synthesized using a reaction between bromoquinone and substituted anilines, and their antimicrobial effectiveness was analyzed, revealing minimum inhibitory concentrations between 16 to 128 μg/ml.
  • Notably, two derivatives showed effectiveness against methicillin-resistant strains, showcasing both bacteriostatic and bactericidal properties and suggesting these compounds as potential new treatments.
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This overview initially describes insect immune reactions and then brings together present knowledge of the interactions of vector insects with their invading parasites and pathogens. It is a way of introducing this Special Issue with subsequent papers presenting the latest details of these interactions in each particular group of vectors. Hopefully, this paper will fill a void in the literature since brief descriptions of vector immunity have now been brought together in one publication and could form a starting point for those interested and new to this important area.

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Herpes simplex virus type 2 (HSV-2) is the most common agent of sexually transmitted infections around the world. Currently, no vaccine is available, and acyclovir is the reference compound in treatment HSV-2 infections. However, the emergence of resistant strains has reduced the efficacy in treatment.

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Sporothrix brasiliensis with low susceptibility isolates were described from the Brazilian zoonotic sporotrichosis hyperendemics. The aim of this work was to evaluate distinct fractions of Ocotea pulchella, Ocotea notata, Myrciaria floribunda, and Hypericum brasiliense plant extracts against itraconazole-sensitive and low susceptibility S. brasiliensis isolates.

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Despite intramuscular vaccines saving millions of lives, constant devastating waves of SARS-CoV-2 infections continue. The elimination of COVID-19 is challenging, but necessary in order to avoid millions more people who would suffer from long COVID if we fail. Our paper describes rapidly advancing and innovative therapeutic strategies for the early stage of infection with COVID-19 so that tolerating continuing cycles of infection should be unnecessary in the future.

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Article Synopsis
  • - The study focuses on evaluating new quinolone derivatives as potential antiviral agents against herpes simplex virus (HSV) due to the emergence of resistant strains.
  • - In vitro tests showed that these compounds effectively inhibited HSV replication, particularly by suppressing ICP27 viral protein expression, with EC values ranging from 8 μM to 32 μM, and highlighted the importance of specific chemical structures for effectiveness.
  • - While these new derivatives exhibited lower antiviral activity than acyclovir, they demonstrated unique mechanisms of action, warranting further pre-clinical research to develop these agents as alternative HSV treatments.
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This study aimed at identifying the perceptions of Brazilian postgraduate students from all over the country on the impacts of the COVID-19 pandemic on their academic trajectories. Data from 5985 postgraduate students were collected in the end of 2020, through a 37-item questionnaire, including multiple-choice questions, through Google Forms. The questions were divided into blocks with different proposals: personal profile, academic profile, issues related to COVID-19 infection, and issues related to mental health.

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Article Synopsis
  • Snakebite envenoming is a serious health issue and classified as a neglected tropical disease by the WHO since 2017.
  • This study examined the effectiveness of ten 1,2,3-triazole derivatives (AM001 to AM010) in inhibiting various toxic activities of snake venom, including coagulant and lethal effects.
  • The derivatives showed promise in reducing venom toxicity without being harmful themselves, particularly AM006 and AM010, suggesting they could be helpful in treating local effects of snakebites.
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The drug delivery systems are an important strategy of pharmaceutical technology to modulate undesirable properties, increasing efficacy, and reducing the side effects of active pharmaceutical ingredients (API). The sustained release is a type of controlled-release system that provides a suitable drug level in the blood through a slow release rate. An interesting alternative to achieve a controlled release is the application of carrier materials such as polymers, cyclodextrins, and clays.

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This article presents an overview of paratransgenesis as a strategy to control pathogen transmission by insect vectors. It first briefly summarises some of the disease-causing pathogens vectored by insects and emphasises the need for innovative control methods to counter the threat of resistance by both the vector insect to pesticides and the pathogens to therapeutic drugs. Subsequently, the state of art of paratransgenesis is described, which is a particularly ingenious method currently under development in many important vector insects that could provide an additional powerful tool for use in integrated pest control programmes.

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Cancer remains among the world's top devastating diseases, with millions of lives been affected each year. Conventional anticancer therapies are often far from ideal due to non-selective biodistribution. Therefore, the carbon nanotube (CNT) has been developed as a drug carrier for targeting specific cancer cells.

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Recently, the well-known geographically wide distribution of sporotrichosis in Brazil, combined with the difficulties of effective domestic feline treatment, has emphasized the pressing need for new therapeutic alternatives. This work considers a range of synthetic derivatives as potential antifungals against isolated from cats from the hyperendemic Brazilian region. Six isolates from the sporotrichotic lesions of itraconazole responsive or non-responsive domestic cats were studied.

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Introduction: The search for an animal model capable of reproducing the physiopathology of the COVID-19, and also suitable for evaluating the efficacy and safety of new drugs has become a challenge for many researchers.

Areas Covered: This work reviews the current animal models for tests with SARS-CoV-2 as well as the challenges involved in the safety and efficacy trials.

Expert Opinion: Studies have reported the use of nonhuman primates, ferrets, mice, Syrian hamsters, lagomorphs, mink, and zebrafish in experiments that aimed to understand the course of COVID-19 or test vaccines and other drugs.

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Background: The importance of health professionals has been recognized in COVID-19 pandemic-affected countries, especially in those such as Brazil, which is one of the top 3 countries that have been affected in the world. However, the workers' perception of the stress and the changes that the pandemic has caused in their lives vary according to the conditions offered by these affected countries, including salaries, individual protection equipment, and psychological support.

Objective: The purpose of this study was to identify the perceptions of Brazilian health workers regarding the COVID-19 pandemic impact on their lives, including possible self-contamination and mental health.

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The editors of several major journals have recently asserted the importance of combating racism and sexism in science. This is especially relevant now, as the COVID-19 pandemic may have led to a widening of the gender and racial/ethnicity gaps. Implicit bias is a crucial component in this fight.

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Ethylhexyl methoxycinnamate (EHMC) (CAS number: 5466-77-3) and butyl methoxydibenzoylmethane (BMDM) (CAS number: 70356-09-1) are important sunscreens. However, frequent application of large amounts of these compounds may reflect serious environmental impact, once it enters the environment through indirect release via wastewater treatment or immediate release during water activities. In this article, we reviewed the toxicological effects of EHMC and BMDM on aquatic ecosystems and the human consequences.

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Bovine mastitis is an infectious disease that affects the mammary gland of dairy cattle with considerable economic losses. Staphylococcus aureus is the main microorganism involved in this highly contagious process, and the treatment is only using antibiotics. Currently, the search for new treatment and/or compounds is still in need due to microbial resistance.

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Since the very beginning of the COVID-19 pandemic, different treatment strategies have been explored. These mainly involve the development of antimicrobial, antiviral, and/or anti-inflammatory agents as well as vaccine production. However, other potential options should be more avidly investigated since vaccine production on a worldwide level, and the anti-vaccination movement, also known as anti-vax or vaccine hesitancy by many communities, are still real obstacles without a ready solution.

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Article Synopsis
  • Antimicrobial resistance poses a significant challenge despite available antibiotics, leading to the urgent need for new drug development.
  • This study focused on synthetic N,O-acetals from 2-amino-1,4-naphthoquinone and their effectiveness against methicillin-resistant Staphylococcus aureus (MRSA), particularly highlighting the notable impact of compound 7b on biofilm formation.
  • Compound 7b was found to inhibit key virulence genes and showed potential to eliminate persistent bacterial cells, making it a promising candidate for future antimicrobial research aimed at treating chronic infections associated with biofilm.
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The COVID-19 pandemic has had global catastrophic effects on financial markets, jobs and peoples' lives. Future prevention/therapy of COVID-19 will rely heavily on vaccine development and attempts to repurpose drugs previously used for other microbial diseases. Little attention, however, has been paid to possible difficulties and delays in producing these drugs.

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