166 research outputs found
Drugs for neglected diseases: a failure of the market and a public health failure?
Infectious diseases cause the suffering of hundreds of millions of people, especially in tropical and subtropical areas. Effective, affordable and easy-to-use medicines to fight these diseases are nearly absent. Although science and technology are sufficiently advanced to provide the necessary medicines, very few new drugs are being developed. However, drug discovery is not the major bottleneck. Today's R&D-based pharmaceutical industry is reluctant to invest in the development of drugs to treat the major diseases of the poor, because return on investment cannot be guaranteed. With national and international politics supporting a free market-based world order, financial opportunities rather than global health needs guide the direction of new drug development. Can we accept that the dearth of effective drugs for diseases that mainly affect the poor is simply the sad but inevitable consequence of a global market economy? Or is it a massive public health failure, and a failure to direct economic development for the benefit of society? An urgent reorientation of priorities in drug development and health policy is needed. The pharmaceutical industry must contribute to this effort, but national and international policies need to direct the global economy to address the true health needs of society. This requires political will, a strong commitment to prioritize health considerations over economic interests, and the enforcement of regulations and other mechanisms to stimulate essential drug development. New and creative strategies involving both the public and the private sector are needed to ensure that affordable medicines for today's neglected diseases are developed. Priority action areas include advocating an essential medicines R&D agenda, capacity-building in and technology transfer to developing countries, elaborating an adapted legal and regulatory framework, prioritizing funding for essential drug development and securing availability, accessibility, distribution and rational use of these drugs
Comparative efficacy and safety of targeted therapies for BRAF-mutant unresectable or metastatic melanoma: Results from a systematic literature review and a network meta-analysis
Background: The objective of this study was to estimate the relative efficacy and safety of targeted therapies for the treatment of metastatic melanoma using a network meta-analysis (NMA).
Methods: A systematic literature review (SLR) identified studies in Medline, Embase and Cochrane published until November 2020. Screening used prespecified eligibility criteria. Following a transitivity assessment across included studies, Bayesian NMA was conducted.
Results: A total of 43 publications reporting 15 targeted therapy trials and 42 reporting 18 immunotherapy trials were retained from the SLR and considered for the NMA. Due to substantial between-study heterogeneity with immunotherapy trials, the analysis considered a network restricted to targeted therapies. Among combination therapies, encorafenib + binimetinib was superior to dabrafenib + trametinib for overall response rate (OR = 1.86; 95 % credible interval [CrI] 1.10, 3.17), superior to vemurafenib + cobimetinib with fewer serious adverse events (SAEs) (OR = 0.51; 95 % CrI 0.29, 0.91) and fewer discontinuations due to AEs (OR = 0.45; 95 % CrI 0.21, 0.96), and superior to atezolizumab + vemurafenib + cobimetinib with fewer SAEs (OR = 0.41; 95 % CrI 0.21, 0.82). Atezolizumab + vemurafenib + cobimetinib and encorafenib + binimetinib were generally comparable for efficacy endpoints. Among double combination therapies, encorafenib + binimetinib showed high probabilities of being better for all efficacy and safety endpoints.
Conclusions: This NMA confirms that combination therapies are more efficacious than monotherapies. Encorafenib + binimetinib has a favourable efficacy profile compared to other double combination therapies and a favourable safety profile compared to both double and triple combination therapies
Study of a Nonlocal Density scheme for electronic--structure calculations
An exchange-correlation energy functional beyond the local density
approximation, based on the exchange-correlation kernel of the homogeneous
electron gas and originally introduced by Kohn and Sham, is considered for
electronic structure calculations of semiconductors and atoms. Calculations are
carried out for diamond, silicon, silicon carbide and gallium arsenide. The
lattice constants and gaps show a small improvement with respect to the LDA
results.
However, the corresponding corrections to the total energy of the isolated
atoms are not large enough to yield a substantial improvement for the cohesive
energy of solids, which remains hence overestimated as in the LDA.Comment: 4 postscript figure
Cellular Defense Mechanisms Following Nanomaterial Exposure: A Focus on Oxidative Stress and Cytotoxicity
Dynamical properties of liquid Al near melting. An orbital-free molecular dynamics study
The static and dynamic structure of liquid Al is studied using the orbital
free ab-initio molecular dynamics method. Two thermodynamic states along the
coexistence line are considered, namely T = 943 K and 1323 K for which X-ray
and neutron scattering data are available. A new kinetic energy functional,
which fulfills a number of physically relevant conditions is employed, along
with a local first principles pseudopotential. In addition to a comparison with
experiment, we also compare our ab-initio results with those obtained from
conventional molecular dynamics simulations using effective interionic pair
potentials derived from second order pseudopotential perturbation theory.Comment: 15 pages, 12 figures, 2 tables, submitted to PR
The chemical characterization of Nigerian propolis samples and their activity against Trypanosoma brucei.
Profiling of extracts from twelve propolis samples collected from eight regions in Nigeria was carried out using high performance liquid chromatography (LC) coupled with evaporative light scattering (ELSD), ultraviolet detection (UV) and mass spectrometry (MS), gas chromatography mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR). Principal component analysis (PCA) of the processed LC-MS data demonstrated the varying chemical composition of the samples. Most of the samples were active against Trypanosoma b.brucei with the highest activity being in the samples from Southern Nigeria. The more active samples were fractionated in order to isolate the component(s) responsible for their activity using medium pressure liquid chromatography (MPLC). Three xanthones, 1,3,7-trihydroxy-2,8-di-(3-methylbut-2-enyl)xanthone, 1,3,7-trihydroxy-4,8-di-(3-methylbut-2-enyl)xanthone a previously undescribed xanthone and three triterpenes: ambonic acid, mangiferonic acid and a mixture of α-amyrin with mangiferonic acid (1:3) were isolated and characterised by NMR and LC-MS. These compounds all displayed strong inhibitory activity against T.b.brucei but none of them had higher activity than the crude extracts. Partial least squares (PLS) modelling of the anti-trypanosomal activity of the sample extracts using the LC-MS data indicated that high activity in the extracts, as judged from LCMS
2data, could be correlated to denticulatain isomers in the extracts
Neglected Tropical Diseases outside the Tropics
Neglected Tropical Diseases (NTDs) have been targeted due to their prevalence and the burden of disease they cause globally, but there has been no significant focus in the literature on the subject of NTDs as a group in immigrants and travelers, and no specific studies on the emerging phenomenon of imported NTDs. We present the experience of a Tropical Medicine Unit in a major European city, over a 19-year period, describing and comparing NTDs diagnosed amongst immigrants, travelers and travelers visiting friends and relatives (VFRs). NTDs were diagnosed outside tropical areas and occurred more frequently in immigrants, followed by VFR travelers and then by other travelers. The main NTDs diagnosed in immigrants were onchocerciasis, Chagas disease and ascariasis; most frequent NTDs in travelers were schistosomiasis, onchocerciasis and ascariasis, and onchocerciasis and schistosomiasis in VFRs. Issues focusing on modes of transmission outside endemic areas and how eradication programs for some NTDs in endemic countries may have an impact in non-tropical Western countries by decreasing disease burden in immigrants, are addressed. Adherence to basic precautions such as safe consumption of food/water and protection against arthropod bites could help prevent many NTDs in travelers
Genotoksičnost metalnih nanočestica: osvrt na podatke istraživanja In vivo
With increasing production and application of a variety of nanomaterials (NMs), research on their cytotoxic and genotoxic potential grows, as the exposure to these nano-sized materials may potentially result in adverse health effects. In large part, indications for potential DNA damaging effects of nanoparticles (NPs) originate from inconsistent in vitro studies. To clarify these effects, the implementation of in vivo studies has been emphasised. This paper summarises study results of genotoxic effects of NPs, which are available in the recent literature. They provide indications that some NP types cause both DNA strand breaks and chromosomal damages in experimental animals. Their genotoxic effects, however, do not depend only on particle size, surface modifi cation (particle coating), and exposure route, but also on exposure duration. Currently available animal studies may suggest differing mechanisms (depending on the duration of exposure) by which living organisms react to NP contact. Nevertheless, due to considerable inconsistencies in the recent literature and the lack of standardised test methods - a reliable hazard assessment of NMs is still limited. Therefore, international organisations (e.g. NIOSH) suggest utmost caution when potential exposure of humans to NMs occurs, as long as evidence of their toxicological and genotoxic effect(s) is limited.S povećanjem proizvodnje i primjene niza različitih nanomaterijala (NM) raste i potreba istraživanja njihovih mogućih citotoksičnih i genotoksičnih učinaka kao i drugih štetnih učinaka na zdravlje u uvjetima profesionalne ili opće izloženost ljudi. Indikacije potencijanog oštećenja DNA kojeg uzrokuju nanočestice u velikoj mjeri proizlaze iz nedosljednih in vitro ispitivanja. Kako bi se razjasnili ti učinci, naglašena je potreba provedbe in vivo ispitivanja. Ovaj pregledni rad sažima rezultate procjene genotoksičnih učinaka nanočestica koji su objavljeni u novijoj stručnoj i znanstvenoj literaturi. Navedeni rezultati pokazuju da određene nanočestice uzrokuju lomove u molekuli DNA i oštećuju kromosome u eksperimentalnim životinjama. Njihovi genotoksični učinci ne ovise samo o veličini čestice, modifi kaciji površine (oblaganje čestice) i načinu izlaganja, već i o trajanju izloženosti nanočesticama. Postojeća istraživanja provedena na životinjama upućuju na različite mehanizme koji ovise o trajanju izlaganja i pomoću kojih živi organizmi reagiraju na doticaj s nanočesticama. Međutim postoje brojne nedosljednosti u novijoj literaturi, a standardne testne metode nisu dostupne pa je stoga pouzdanija procjena opasnosti od izlaganja nanomaterijalima u ljudi još uvijek veoma ograničena. Stoga se u međunarodnim dokumentima savjetuje oprez prilikom svakog izlaganja ljudi nanomaterijalima kako bi se spriječili mogući opći toksični genotoksični učinci
E-β-Ocimene, a Volatile Brood Pheromone Involved in Social Regulation in the Honey Bee Colony (Apis mellifera)
Background: In honey bee colony, the brood is able to manipulate and chemically control the workers in order to sustain their own development. A brood ester pheromone produced primarily by old larvae (4 and 5 days old larvae) was first identified as acting as a contact pheromone with specific effects on nurses in the colony. More recently a new volatile brood pheromone has been identified: E-β-ocimene, which partially inhibits ovary development in workers. [br/]
Methodology and Principal Finding: Our analysis of E-β-ocimene production revealed that young brood (newly hatched to 3 days old) produce the highest quantity of E-b-ocimene relative to their body weight. By testing the potential action of this molecule as a non-specific larval signal, due to its high volatility in the colony, we demonstrated that in the presence of E-β-ocimene nest workers start to forage earlier in life, as seen in the presence of real brood. [br/]
Conclusions/Significance: In this way, young larvae are able to assign precedence to the task of foraging by workers in order to increase food stores for their own development. Thus, in the complexity of honey bee chemical communication, E-β- ocimene, a pheromone of young larvae, provides the brood with the means to express their nutritional needs to the workers
Global plagues and the Global Fund: Challenges in the fight against HIV, TB and malaria
BACKGROUND: Although a grossly disproportionate burden of disease from HIV/AIDS, TB and malaria remains in the Global South, these infectious diseases have finally risen to the top of the international agenda in recent years. Ideal strategies for combating these diseases must balance the advantages and disadvantages of 'vertical' disease control programs and 'horizontal' capacity-building approaches. DISCUSSION: The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) represents an important step forward in the struggle against these pathogens. While its goals are laudable, significant barriers persist. Most significant is the pitiful lack of funds committed by world governments, particularly those of the very G8 countries whose discussions gave rise to the Fund. A drastic scaling up of resources is the first clear requirement for the GFATM to live up to the international community's lofty intentions. A directly related issue is that of maintaining a strong commitment to the treatment of the three diseases along with traditional prevention approaches, with the ensuing debates over providing affordable access to medications in the face of the pharmaceutical industry's vigorous protection of patent rights. SUMMARY: At this early point in the Fund's history, it remains to be seen how these issues will be resolved at the programming level. Nevertheless, it is clear that significant structural changes are required in such domains as global spending priorities, debt relief, trade policy, and corporate responsibility. HIV/AIDS, tuberculosis and malaria are global problems borne of gross socioeconomic inequality, and their solutions require correspondingly geopolitical solutions
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