448 research outputs found

    Two crystal forms of a hydrated 2:1 b-cyclodextrin× fluconazole complex: Single crystal x-ray structures, dehydration profiles, and conditions for their individual isolation

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    Inclusion complexes between cyclodextrins (CDs) and active pharmaceutical ingredients (APIs) have potential for pharmaceutical formulation. Since crystallization of a given complex may result in the isolation of multiple crystal forms, it is essential to characterize these forms with respect to their structures and physicochemical properties to optimize pharmaceutical candidate selection. Here, we report the preparation and characterization of two crystallographically distinct hydrated forms of an inclusion complex between β-cyclodextrin (β-CD) and the antifungal API fluconazole (FLU) as well as temperature–concentration conditions required for their individual isolation. Determination of crystal water contents was achieved using thermoanalytical methods. X-ray analyses revealed distinct structural differences between the triclinic (TBCDFLU, space group P1) and monoclinic (MBCDFLU, space group C2) crystal forms. Removal of the crystals from their mother liquors led to rapid dehydration of the MBCDFLU crystal, while the TBCDFLU crystal was stable, a result that could be reconciled with the distinct packing arrangements in the respective crystals. This study highlights (a) the importance of identifying possible multiple forms of a cyclodextrin×API complex and controlling the crystallization conditions, and (b) the need to characterize such crystal forms to determine the extent to which their physicochemical properties may differ

    Prevalence and factors associated with not receiving the booster dose of the COVID-19 vaccine in adults in Latin America and the Caribbean

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    "Background: Booster doses have been described as effective in reducing hospitalizations and deaths from the new variants. However, its coverage is heterogeneous in Latin America and the Caribbean (LAC), one of the regions most affected by the pandemic. We aimed to assess the factors associated with not receiving a coronavirus disease 2019 (COVID-19) vaccine booster dose in adults from LAC. Methods: We analyzed a secondary database compiled by the University of Maryland and Facebook assessing the global impact of COVID-19. We included Facebook users over 18 years of age who resided in LAC and responded to the survey between February 13, 2022, and March 14, 2022. We evaluated sociodemographic characteristics, comorbidities, food, and economic insecurity, mental health, and vaccination-related practices. We calculated crude (cPR) and adjusted (aPR) prevalence ratios with their respective 95% confidence intervals (95%CI). Results: The sample included 154,841 adults from 20 LAC countries. 33.7% (n = 46,459) reported not receiving the COVID-19 booster vaccine. Being under 75 years old, having a college, high school, pre-university, primary, or lower education, having no or 1 to 2 comorbidities, living in a town, having food insecurity, depressive symptoms, and having had COVID-19, were associated with a higher prevalence of not receiving the booster dose. In contrast, being female or non-binary and having anxiety symptoms were associated with a lower prevalence of not receiving the booster dose. Conclusions: Approximately three out of 10 adults surveyed in LAC reported not having received the booster vaccine. Authorities must design campaigns that promote receiving a booster dose considering the factors found.

    Inclusion of Hydroxycinnamic Acids in Methylated Cyclodextrins: Host-Guest Interactions and Effects on Guest Thermal Stability

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    There is ongoing interest in exploiting the antioxidant activity and other medicinal properties of natural monophenolic/polyphenolic compounds, but their generally low aqueous solubility limits their applications. Numerous studies have been undertaken to solubilize such compounds via supramolecular derivatization with co-crystal formation with biocompatible coformer molecules and cyclodextrin (CD) complexation being two successful approaches. In this study, eight new crystalline products obtained by complexation between methylated cyclodextrins and the bioactive phenolic acids (ferulic, hydroferulic, caffeic, and p-coumaric acids) were investigated using thermal analysis (hot stage microscopy, thermogravimetry, differential scanning calorimetry) and X-ray diffraction. All of the complexes crystallized as ternary systems containing the host CD, a phenolic acid guest, and water. On heating each complex, the primary thermal events were dehydration and liberation of the respective phenolic acid component, the mass loss for the latter step enabling determination of the host-guest stoichiometry. Systematic examination of the X-ray crystal structures of the eight complexes enabled their classification according to the extent of inclusion of each guest molecule within the cavity of its respective CD molecule. This revealed three CD inclusion compounds with full guest encapsulation, three with partial guest inclusion, and two that belong to the rare class of ‘non-inclusion’ compounds

    Identification of a new cocrystal of citric acid and paracetamol of pharmaceutical relevance

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    Cocrystals have been increasingly recognized as an attractive alternative delivery form for solid drug products. In this work, Raman spectroscopy, X-ray powder diffraction/X-ray crystallography, and differential scanning calorimetry have been used to study the phenomenon of cocrystal formation in stoichiometric mixtures of citric acid with paracetamol. Raman spectroscopy was particularly useful for the characterization of the products and was used to determine the nature of the interactions in the cocrystals. It was observed that little change in the vibrational modes associated with the phenyl groups of the respective reactants took place upon cocrystal formation but changes in intensities of the vibrational modes associated with the amide and the carboxylic acid groups were observed upon cocrystal formation. Several new vibrational bands were identified in the cocrystal which were not manifest in the raw material and could be used as diagnostic features of cocrystal formation. An understanding of the effects of cocrystal formation on the vibrational modes was obtained by the complete assignment of the spectra of the starting materials and of the cocrystal component. The results show that the cocrystals was obtained in a 2:1 molar ratio of paracetamol to citric acid. The asymmetric unit of the crystal contains two paracetamol molecules hydrogen-bonded to the citric acid; one of these acts as a phenolic-OH hydrogen bond donor to the carbonyl of a carboxylic acid arm of citric acid. In contrast, the other phenolic-OH acts as a hydrogen bond acceptor from the quaternary C-OH of citric acid. © 2011 The Royal Society of Chemistry

    Toxoplasma gondii infection in patients with hematological malignancies.

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    Toxoplasmosis is one of the most common parasitic infections in humans, but in most cases it does not cause serious illness; this protozoan can nevertheless cause devastating disease in immunocompromised hosts such as HIV-positive individuals. Only rarely is toxoplasmosis documented in hematological patients, and among them, those who undergo a transplant procedure are more frequently affected. In a retrospective multicenter survey, we collected data on six cases of toxoplasmosis in hematological patients. In the majority of cases, patients had undergone transplant procedures (five had undergone autologous or allogeneic transplantation). This complication needed special care in diagnosis, usually based on serology, neuroradiology, and PCR examination. However, in our experience the appropriate therapeutic approach was successful in the majority of cases

    Bis(acetyl­acetonato-κ2 O,O′)(2-amino-1-methyl-1H-benzimidazole-κN 3)oxido­vanadium(IV)

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    The title mixed-ligand oxidovanadium(IV) compound, [VO(C5H7O2)2(C8H9N3)], contains a VIV atom in a distorted octahedral coordination, which is typical for such complexes. The vanadyl group and the N-heterocyclic ligand are cis to each other. The coordination bond is located at the endocyclic N atom of the benzimidazole ligand. Intra­molecular hydrogen bonds between the exo-NH2 group H atoms and acetyl­acetonate O atoms stabilize the crystal structure

    Systemic antifungal treatment after posaconazole prophylaxis: results from the SEIFEM 2010-C survey.

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    OBJECTIVES: To investigate the incidence, treatment and outcome of breakthrough invasive fungal infections (IFIs) in adult acute myeloid leukaemia (AML) patients after posaconazole prophylaxis. METHODS: From January 2010 to April 2012, all consecutive patients with newly diagnosed AML were prospectively registered at 33 participating Italian centres. All cases of IFIs occurring within 30 days after the end of the first induction chemotherapy were recorded. The strategy of antifungal treatment (empirical, pre-emptive or targeted) and the drugs used were analysed. ClinicalTrials.gov code: NCT01315925. RESULTS: In total, 1192 patients with newly diagnosed AML were enrolled in the study, of whom 510 received posaconazole prophylaxis and were included in the present analysis. Of these patients, 140 (27%) needed systemic antifungal treatment. Among the 127 evaluable cases, an empirical approach was utilized in 102 patients (80%), a pre-emptive approach in 19 patients (15%) and targeted therapy in 6 patients (5%). Only five patients died of IFIs (three in the empirical group and two in the targeted group; 4%). A critical review of IFI diagnoses at 30 days demonstrated that among the patients treated empirically, ∼30% were not affected by IFIs but rather only by fever of unidentified origin. A comparison between the empirical and the pre-emptive groups showed no significant differences regarding the attributable and overall mortalities. CONCLUSIONS: This study confirms that posaconazole prophylaxis reduces the incidence of breakthrough IFIs and does not modify the efficacy of subsequent systemic antifungal treatment, regardless of the approach (empirical or pre-emptive) or the antifungal drug used

    Liver X receptors, lipids and their reproductive secrets in the male

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    International audienceLiver X receptor (LXR) a and LXRb belong to the nuclear receptor superfamily. For many years they have been called orphan receptors, as no natural ligand was identified. In the last decade the LXR natural ligands have been shown to be oxysterols, molecules derived from cholesterol. While these nuclear receptors have been abundantly studied for their roles in the regulation of lipid metabolism, it appears that they also present crucial activities in reproductive organs such as testis and epididymis, as well as prostate. Phenotypic analyses of mice lacking LXRs (−/−) pointed out their physiological activies in the various cells and organs regulating reproductive functions. This review summarizes the impact of LXR-deficiency in male reproduction, highlighting the novel information coming from the phenotypic analyses of −/−, −/− and −/− mice

    Spiral valve parasites of blue and common thresher sharks as indicators of shark feeding behaviour and ecology

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    Open Access via the Jisc Wiley agreement Acknowledgements This work would not have been possible without the assistance and samples provided by the National Marine Fisheries Service (NMFS) Southwest Region Fishery Observer Program and the participating drift gillnet fishermen. A. Arevalo, E. Reed, H. Colley, J. Williams, J. Tamez and K. Tran assisted with spiral valve dissections and parasite sorting in the lab. D. Losey helped with library research. D. Sweetnam, A. Yau, A. Thompson, M. Craig, S. Stohs, G. DiNardo provided constructive critiques that helped improve the manuscript. This research was supported by the National Oceanographic Atmospheric Administration (NOAA).Peer reviewedPublisher PD

    Genetic PTX3 deficiency and aspergillosis in stem-cell transplantation

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    BACKGROUND: The soluble pattern-recognition receptor known as long pentraxin 3 (PTX3) has a nonredundant role in antifungal immunity. The contribution of single-nucleotide polymorphisms (SNPs) in PTX3 to the development of invasive aspergillosis is unknown. METHODS: We screened an initial cohort of 268 patients undergoing hematopoietic stem-cell transplantation (HSCT) and their donors for PTX3 SNPs modifying the risk of invasive aspergillosis. The analysis was also performed in a multicenter study involving 107 patients with invasive aspergillosis and 223 matched controls. The functional consequences of PTX3 SNPs were investigated in vitro and in lung specimens from transplant recipients. RESULTS: Receipt of a transplant from a donor with a homozygous haplotype (h2/h2) in PTX3 was associated with an increased risk of infection, in both the discovery study (cumulative incidence, 37% vs. 15%; adjusted hazard ratio, 3.08; P=0.003) and the confirmation study (adjusted odds ratio, 2.78; P=0.03), as well as with defective expression of PTX3. Functionally, PTX3 deficiency in h2/h2 neutrophils, presumably due to messenger RNA instability, led to impaired phagocytosis and clearance of the fungus. CONCLUSIONS: Genetic deficiency of PTX3 affects the antifungal capacity of neutrophils and may contribute to the risk of invasive aspergillosis in patients treated (Funded by the European Society of Clinical Microbiology and Infectious Diseases and others) .with HSCT.Supported by grants from the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) (to Dr. Carvalho); the German Ministry for Education and Science (03Z2JN21, to Dr. Kurzai); the European Commission (FP7-HEALTH-2009-260338, to Dr. Romani; FP7-HEALTH-2011-280873, to Dr. Mantovani), the European Research Council (ERC-2008-AdG-233417, to Dr. Mantovani; ERC-2011-AdG-293714, to Dr. Romani), Associazione Italiana per la Ricerca sul Cancro (99629, to Dr. Mantovani); and Fundacao para a Ciencia e Tecnologia, Portugal (SFRH/BPD/46292/2008, to Dr. Carvalho; SFRH/BD/65962/2009, to Dr. Cunha; and SFRH/BPD/70783/2010, to Dr. Almeida)
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