22 research outputs found

    Local Skin Inflammation in Cutaneous Leishmaniasis as a Source of Variable Pharmacokinetics and Therapeutic Efficacy of Liposomal Amphotericin B.

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    Disfiguring skin lesions caused by several species of the Leishmania parasite characterize cutaneous leishmaniasis (CL). Successful treatment of CL with intravenous (i.v.) liposomal amphotericin B (LAmB) relies on the presence of adequate antibiotic concentrations at the dermal site of infection within the inflamed skin. Here, we have investigated the impact of the local skin inflammation on the pharmacokinetics (PK) and efficacy of LAmB in two murine models of localized CL (Leishmania major and Leishmania mexicana) at three different stages of disease (papule, initial nodule, and established nodule). Twenty-four hours after the administration of one 25 mg/kg of body weight LAmB (i.v.) dose to infected BALB/c mice (n = 5), drug accumulation in the skin was found to be dependent on the causative parasite species (L. major > L. mexicana) and the disease stage (papule > initial nodule > established nodule > healthy skin). Elevated tissue drug levels were associated with increased vascular permeability (Evans blue assay) and macrophage infiltration (histomorphometry) in the infected skin, two pathophysiological parameters linked to tissue inflammation. After identical treatment of CL in the two models with 5 × 25 mg/kg LAmB (i.v.), intralesional drug concentrations and reductions in lesion size and parasite load (quantitative PCR [qPCR]) were all ≥2-fold higher for L. major than for L. mexicana In conclusion, drug penetration of LAmB into CL skin lesions could depend on the disease stage and the causative Leishmania species due to the influence of local tissue inflammation

    Orally Administered Activated Charcoal as a Medical Countermeasure for Acute Radiation Syndrome in Rats

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    Activated charcoal (AC) can be taken orally as enterosorbent for treatment of pathological states related to exogenous and endogenous intoxications. Synthesized granulated AC with a highly developed active surface (SBET ~2700 m2/g) was used as a medical countermeasure (MCM) to acute radiation sickness (ARS) in rats after total body X-ray irradiation. AC demonstrates positive results in ARS treatment, as expressed in, (i) a decrease in body weight loss, (ii) a protection of bone marrow (BM) cells colony formation capacity, (iii) a reduction of BM chromosomal aberrations and small intestine and spleen tissue damage, (iv) an amelioration of white blood cell count, and (v) a mitigation of superoxide ion generation rate in the liver. AC oral prescription seems to be perspective modality of ARS treatment.This research was funded by H2020-MSCA-RISE-2016 project, grant number 734641 acronym NanoMed

    Film-Forming Systems for the Delivery of DNDI-0690 to Treat Cutaneous Leishmaniasis.

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    In cutaneous leishmaniasis (CL), parasites reside in the dermis, creating an opportunity for local drug administration potentially reducing adverse effects and improving treatment adherence compared to current therapies. Polymeric film-forming systems (FFSs) are directly applied to the skin and form a thin film as the solvent evaporates. In contrast to conventional topical dosage forms, FFSs strongly adhere to the skin, favouring sustained drug delivery to the affected site, reducing the need for frequent applications, and enhancing patient compliance. This study reports the first investigation of the use of film-forming systems for the delivery of DNDI-0690, a nitroimidazole compound with potent activity against CL-causing Leishmania species. A total of seven polymers with or without plasticiser were evaluated for drying time, stickiness, film-flexibility, and cosmetic attributes; three FFSs yielded a positive evaluation for all test parameters. The impact of each of these FFSs on the permeation of the model skin permeant hydrocortisone (hydrocortisone, 1% (w/v) across the Strat-M membrane was evaluated, and the formulations resulting in the highest and lowest permeation flux (Klucel LF with triethyl citrate and Eudragit RS with dibutyl sebacate, respectively) were selected as the FFS vehicle for DNDI-0690. The release and skin distribution of the drug upon application to Leishmania-infected and uninfected BALB/c mouse skin were examined using Franz diffusion cells followed by an evaluation of the efficacy of both DNDI-0690 FFSs (1% (w/v)) in an experimental CL model. Whereas the Eudragit film resulted in a higher permeation of DNDI-0690, the Klucel film was able to deposit four times more drug into the skin, where the parasite resides. Of the FFSs formulations, only the Eudragit system resulted in a reduced parasite load, but not reduced lesion size, when compared to the vehicle only control. Whereas drug delivery into the skin was successfully modulated using different FFS systems, the FFS systems selected were not effective for the topical application of DNDI-0690. The convenience and aesthetic of FFS systems alongside their ability to modulate drug delivery to and into the skin merit further investigation using other promising antileishmanial drugs

    Multiple Sclerosis: LIFNano-CD4 for Trojan Horse Delivery of the Neuro-Protective Biologic “LIF” Into the Brain: Preclinical Proof of Concept

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    Multiple sclerosis (MS) is a demyelinating autoimmune disease that attacks the brain, with year-on-year loss of brain volume, starting late teens and becoming manifest late twenties. There is no cure, and current therapies are immunosuppressive only. LIF is a vital stem cell growth factor active throughout life—and essential for health of the central nervous system (CNS), being tolerogenic, myelinogenic, and neuroprotective. Nano-formulation of LIF (LIFNano) using FDA-approved PLGA captures LIF's compound therapeutic properties, increasing potency 1,000-fold when targeted to CD4 (LIFNano-CD4). Moreover, circulating CD4+ lymphocytes are themselves regulated by LIF to express the Treg phenotype, known to release T cell-derived LIF upon engagement with cognate antigen, perpetuating antigen-specific self-tolerance. With the longer-term aim of treating inflammatory lesions of MS, we asked, does LIFNano-CD4 cross the blood–brain barrier (BBB)? We measure pK and pD using novel methodologies, demonstrate crossing of the BBB, show LIF-cargo-specific anti-inflammatory efficacy in the frontal cortex of the brain, and show safety of intravenous delivery of LIFNano-CD4 at doses known to provide efficacious concentrations of LIF cargo behind the BBB

    Dose-dependent effect and pharmacokinetics of fexinidazole and its metabolites in a mouse model of human African trypanosomiasis.

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    Human African trypanosomiasis (HAT) is a neglected tropical disease, with a population of 70 million at risk. Current treatment options are limited. In the search for new therapeutics, the repurposing of the broad-spectrum antiprotozoal drug fexinidazole has completed Phase III trials with the anticipation that it will be the first oral treatment for HAT. This study used the recently validated bioluminescence imaging model to assess the dose and rate of kill effect of fexinidazole in infected mice, and the dose-dependent effect of fexinidazole on trypanosome infection. Pharmacokinetics of fexinidazole in plasma and central nervous system (CNS) compartments were similar in both infected and uninfected mice. Drug distribution within the CNS was further examined by microdialysis, showing similar levels in the cortex and hippocampus. However, high variability in drug distribution and exposure was found between mice

    Pharmacokinetics and Pharmacodynamics of the Nitroimidazole DNDI-0690 in Mouse Models of Cutaneous Leishmaniasis.

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    The nitroimidazole DNDI-0690 is a clinical drug candidate for visceral leishmaniasis (VL) that also shows potent in vitro and in vivo activity against cutaneous leishmaniasis (CL). To support further development of this compound into a patient-friendly oral or topical formulation for the treatment of CL, we investigated the free drug exposure at the dermal site of infection and subsequent elimination of the causative Leishmania pathogen. This study evaluates the pharmacokinetics (PK) and pharmacodynamics (PD) of DNDI-0690 in mouse models of CL. Skin microdialysis and Franz diffusion cell permeation studies revealed that DNDI-0690 permeated poorly (<1%) into the skin lesion upon topical drug application (0.063% [wt/vol], 30 μl). In contrast, a single oral dose of 50 mg/kg of body weight resulted in the rapid and nearly complete distribution of protein-unbound DNDI-0690 from the plasma into the infected dermis (ratio of the area under the curve [0 to 6 h] of the free DNDI-0690 concentration in skin tissue to blood [fAUC0-6 h, skin tissue/fAUC0-6 h, blood] is greater than 80%). Based on in vivo bioluminescence imaging, two doses of 50 mg/kg DNDI-0690 were sufficient to reduce the Leishmania mexicana parasite load by 100-fold, while 6 such doses were needed to achieve similar killing of L. major; this was confirmed by quantitative PCR. The combination of rapid accumulation and potent activity in the Leishmania-infected dermis indicates the potential of DNDI-0690 as a novel oral treatment for CL

    Efficacy of oleylphosphocholine in experimental cutaneous leishmaniasis.

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    OBJECTIVES: Cutaneous leishmaniasis (CL) is a neglected tropical disease causing a range of skin lesions for which safe and efficacious drugs are lacking. Oleylphosphocholine (OLPC) is structurally similar to miltefosine and has previously demonstrated potent activity against visceral leishmaniasis. We here present the in vitro and in vivo efficacy of OLPC against CL-causing Leishmania species. METHODS: The antileishmanial activities of OLPC were evaluated and compared with miltefosine in vitro against intracellular amastigotes of seven CL-causing species. Following the confirmation of significant in vitro activity, the performance of the maximum tolerated dose of OLPC was evaluated in an experimental murine model of CL followed by a dose-response titration and the efficacy evaluation of four OLPC formulations (two with a fast-release and two with a slow-release profile) using bioluminescent Leishmania major parasites. RESULTS: OLPC demonstrated potent in vitro activity of the same order as miltefosine in the intracellular macrophage model against a range of CL-causing species. A dose of 35 mg of OLPC/kg/day administered orally for 10 days was well-tolerated and able to reduce the parasite load in the skin of L. major-infected mice to a similar extent as the positive control paromomycin (50 mg/kg/day, intraperitoneally) in both in vivo studies. Reducing the dose of OLPC resulted in inactivity and modifying the release profile using mesoporous silica nanoparticles led to a decrease in activity when solvent-based loading was used in contrast to extrusion-based loading, which had no impact on its antileishmanial efficacy. CONCLUSIONS: Together, these data suggest that OLPC could be a promising alternative to miltefosine treatment for CL. Further investigations exploring experimental models with additional Leishmania species and skin pharmacokinetic and dynamic analyses are required

    Sustainability of biohydrogen as fuel: Present scenario and future perspective

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    Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

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    Background Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10-14 and 50-54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings The global TFR decreased from 2.72 (95% uncertainty interval [UI] 2.66-2.79) in 2000 to 2.31 (2.17-2.46) in 2019. Global annual livebirths increased from 134.5 million (131.5-137.8) in 2000 to a peak of 139.6 million (133.0-146.9) in 2016. Global livebirths then declined to 135.3 million (127.2-144.1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2.1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27.1% (95% UI 26.4-27.8) of global livebirths. Global life expectancy at birth increased from 67.2 years (95% UI 66.8-67.6) in 2000 to 73.5 years (72.8-74.3) in 2019. The total number of deaths increased from 50.7 million (49.5-51.9) in 2000 to 56.5 million (53.7-59.2) in 2019. Under-5 deaths declined from 9.6 million (9.1-10.3) in 2000 to 5.0 million (4.3-6.0) in 2019. Global population increased by 25.7%, from 6.2 billion (6.0-6.3) in 2000 to 7.7 billion (7.5-8.0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58.6 years (56.1-60.8) in 2000 to 63.5 years (60.8-66.1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019. Interpretation Over the past 20 years, fertility rates have been dropping steadily and life expectancy has been increasing, with few exceptions. Much of this change follows historical patterns linking social and economic determinants, such as those captured by the GBD Socio-demographic Index, with demographic outcomes. More recently, several countries have experienced a combination of low fertility and stagnating improvement in mortality rates, pushing more populations into the late stages of the demographic transition. Tracking demographic change and the emergence of new patterns will be essential for global health monitoring. Copyright (C) 2020 The Author(s). Published by Elsevier Ltd.Peer reviewe

    Estimating global injuries morbidity and mortality: methods and data used in the Global Burden of Disease 2017 study

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    BACKGROUND: While there is a long history of measuring death and disability from injuries, modern research methods must account for the wide spectrum of disability that can occur in an injury, and must provide estimates with sufficient demographic, geographical and temporal detail to be useful for policy makers. The Global Burden of Disease (GBD) 2017 study used methods to provide highly detailed estimates of global injury burden that meet these criteria. METHODS: In this study, we report and discuss the methods used in GBD 2017 for injury morbidity and mortality burden estimation. In summary, these methods included estimating cause-specific mortality for every cause of injury, and then estimating incidence for every cause of injury. Non-fatal disability for each cause is then calculated based on the probabilities of suffering from different types of bodily injury experienced. RESULTS: GBD 2017 produced morbidity and mortality estimates for 38 causes of injury. Estimates were produced in terms of incidence, prevalence, years lived with disability, cause-specific mortality, years of life lost and disability-adjusted life-years for a 28-year period for 22 age groups, 195 countries and both sexes. CONCLUSIONS: GBD 2017 demonstrated a complex and sophisticated series of analytical steps using the largest known database of morbidity and mortality data on injuries. GBD 2017 results should be used to help inform injury prevention policy making and resource allocation. We also identify important avenues for improving injury burden estimation in the future
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