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► Visual detection based gold and silver nanoparticles aggregation. ► Functionalized and non-functionalized nanoparticles. ► High selectivity and sensitivity. ► No complex ...instrumentation is required/chemical creativity for analyte detection.
Localized surface plasmon resonance (LSPR) is one of the most remarkable features of gold nanoparticles (Au NPs) and silver nanoparticles (Ag NPs). Due to these inherent optical properties, colloidal solutions of Au and Ag NPs have high extinction coefficients and different colour in the visible region of the spectrum when they are well-spaced in comparison with when they are aggregated. Therefore, a well-designed chemical interaction between the analyte and NPs surroundings leads to a change of colour (red to blue for Au NPs and yellow to brown for Ag NPs from well-spaced to aggregated ones, respectively) allowing the visual detection of the target analyte.
These approaches have exhibited an excellent analytical performance with high sensitivities due to the strong LSPR and excellent selectivity strategically driven by the interaction analyte-NPs surroundings involving mainly electrostatic and hydrogen bond interactions as well as donor–acceptor chemical reactions, among others. In addition, this kind of colorimetric assays has received considerable attention in the analytical field because of their simplicity and low cost since they do not require any expensive or complex instrumentation. As a consequence of this, detection of molecules with a high significance in the bio-medical, clinical, food safety and environmental fields including DNA, proteins and a wide spectrum of organic molecules as well as inorganic ions have been impressively reported in the most relevant literature using these assays.
This timely review offers a rational vision of the main achievements yielded in the relevant literature according to this exciting and creative analytical field.
Hepatitis E virus is a major cause of outbreaks as well as sporadic hepatitis cases worldwide. The epidemiology of this enterically transmitted infection differs between developing and developed ...countries. The aims of this study were to describe HEV infection in Colombian patients and to characterize the genotype.
A prospective study was carried out on 40 patients aged over 15 with a clinical diagnosis of viral hepatitis, recruited from five primary health units in the city of Medellin, Colombia. Fecal samples obtained from the 40 consecutives cases were analyzed for HEV RNA using nested reverse transcription PCR for both ORF1 and ORF2-3. The amplicons were sequenced for phylogenetic analyses.
Nine (22.5%) cases of HEV infection were identified in the study population. Three HEV strains obtained from patients were classified as genotype 3. No significant association was found between cases of Hepatitis E and the variables water drinking source, garbage collection system and contact with pigs.
This is the first prospective study of hepatitis E in Colombian patients. The circulation of the genotype 3 in this population is predictable considering the reports of the region and the identification of this genotype from pigs in the state of Antioquia, of which Medellin is the capital. Further studies are necessary to establish whether zoonotic transmission of HEV is important in Colombia.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In a growth phase occurring during most of folliculogenesis, the oocyte produces and accumulates molecules and organelles that are fundamental for the development of the preimplantation embryo. At ...ovulation, growth is followed by a phase of maturation that, although confined within a short temporal window, encompasses modifications of the oocyte chromosome complement and rearrangements of cytoplasmic components that are crucial for the achievement of developmental competence. Cumulus cells (CCs) are central to the process of maturation, providing the oocyte with metabolic support and regulatory cues.
PubMed was used to search the MEDLINE database for peer-reviewed original articles and reviews concerning oocyte maturation in mammals. Searches were performed adopting 'oocyte' and 'maturation' as main terms, in association with other keywords expressing concepts relevant to the subject. The most relevant publications, i.e. those concerning major phenomena occurring during oocyte maturation in established experimental models and the human species, were assessed and discussed critically to offer a comprehensive description of the process of oocyte maturation.
By applying the above described search criteria, 6165 publications were identified, of which 543 were review articles. The number of publications increased steadily from 1974 (n = 7) to 2013 (n = 293). In 2014, from January to the time of submission of this manuscript, 140 original manuscripts and reviews were published. The studies selected for this review extend previous knowledge and shed new and astounding knowledge on oocyte maturation. It has long been known that resumption of meiosis and progression to the metaphase II stage is intrinsic to oocyte maturation, but novel findings have revealed that specific chromatin configurations are indicative of a propensity of the oocyte to resume the meiotic process and acquire developmental competence. Recently, genetic integrity has also been characterized as a factor with important implications for oocyte maturation and quality. Changes occurring in the cytoplasmic compartment are equally fundamental. Microtubules, actin filaments and chromatin not only interact to finalize chromosome segregation, but also crucially co-operate to establish cell asymmetry. This allows polar body extrusion to be accomplished with minimal loss of cytoplasm. The cytoskeleton also orchestrates the rearrangement of organelles in preparation for fertilization. For example, during maturation the distribution of the endoplasmic reticulum undergoes major modifications guided by microtubules and microfilaments to make the oocyte more competent in the generation of intracellular Ca(2+) oscillations that are pivotal for triggering egg activation. Cumulus cells are inherent to the process of oocyte maturation, emitting regulatory signals via direct cell-to-cell contacts and paracrine factors. In addition to nurturing the oocyte with key metabolites, CCs regulate meiotic resumption and modulate the function of the oocyte cytoskeleton.
Although the importance of oocyte maturation for the achievement of female meiosis has long been recognized, until recently much less was known of the significance of this process in relation to other fundamental developmental events. Studies on chromatin dynamics and integrity have extended our understanding of female meiosis. Concomitantly, cytoskeletal and organelle changes and the ancillary role of CCs have been better appreciated. This is expected to inspire novel concepts and advances in assisted reproduction technologies, such as the development of novel in vitro maturation systems and the identification of biomarkers of oocyte quality.
Original results are presented in the field of research that addresses the extension of the reaction of residue of acyl-thiosemicarbazide fixation on the structure of 5-nitrobenzimidazole by a ...sulphonic group. The aim of the study is the increase of new thiosemicarbazide derivatives' applicative potential in the field of biochemistry, with a wide range of medical applications. The newly obtained compounds were characterized by using elemental analysis and spectral analysis (FT-IR and
H NMR). A study regarding the optimization of the chemical reactions was made. The performed in vitro biological tests confirmed the tuberculostatic activity of three newly obtained compounds against
.
6-Iodo-substituted carboxy-quinolines were obtained using a one-pot, three-component method with trifluoroacetic acid as a catalyst under acidic conditions. Iodo-aniline, pyruvic acid and 22 ...phenyl-substituted aldehydes (we varied the type and number of radicals) or O-heterocycles, resulting in different electronic effects, were the starting components. This approach offers advantages such as rapid response times, cost-effective catalysts, high product yields and efficient purification procedures. A comprehensive investigation was conducted to examine the impact of aldehyde structure on the synthesis pathway. A library of compounds was obtained and characterized by FT-IR, MS,
H NMR and
C NMR spectroscopy and single-ray crystal diffractometry. Their antimicrobial activity against
,
and
was tested in vitro. The effect of iodo-quinoline derivatives on microbial adhesion, the initial stage of microbial biofilm development, was also investigated. This study suggests that carboxy-quinoline derivatives bearing an iodine atom are interesting scaffolds for the development of novel antimicrobial agents.
Abstract
Context
Limited natural history data are available in patients with non-HIV–related lipodystrophy syndromes who never received disease-specific therapies, making interpretation of benefits ...of therapies in lipodystrophy syndromes challenging.
Objective
We assessed the natural history of non-HIV–related generalized lipodystrophy (GL) and partial lipodystrophy (PL) in patients who have never received leptin or other lipodystrophy-specific therapies.
Design/Setting/Patients
We conducted an international chart review of 230 patients with confirmed GL or PL at five treatment centers who never received leptin or other lipodystrophy-specific therapies. Patients were observed from birth to loss to follow-up, death, or date of chart abstraction.
Outcome Measures
Lifetime prevalence of diabetes/insulin resistance and select organ abnormalities, time to diabetes/insulin resistance, first organ abnormality, disease progression, and mortality were described.
Results
Diabetes/insulin resistance was identified in 58.3% of patients. Liver abnormalities were the most common organ abnormality (71.7%), followed by kidney (40.4%), heart (30.4%), and pancreatitis (13.0%). Kaplan-Meier estimates of mean (SE) time to first organ abnormality were 7.7 years (0.9) in GL and 16.1 years (1.5) in PL (P < 0.001). Mean time to diabetes/insulin resistance was 12.7 years (1.2) in GL and 19.1 years (1.7) in PL (P = 0.131). Mean time to disease progression was 7.6 years (0.8) and comparable between GL and PL subgroups (P = 0.393). Mean time to death was 51.2 years (3.5) in GL and 66.6 years (1.0) in PL (P < 0.001).
Conclusions
This large-scale study provides comprehensive, long-term data across multiple countries on the natural history of non-HIV–related lipodystrophy.
This international chart review of patients with lipodystrophy syndromes describes the disease natural history and highlights differences between generalized and partial forms.
► We evaluated undigested and in vitro digested blackberry metabolites. ► Blackberry digested in vitro showed different phenolic composition. ► Physiological concentrations of undigested metabolites ...did not protect neurons. ► Digested metabolites protected neuroblastoma from death contrary to undigested ones. ► Mechanisms beyond cellular antioxidant systems are involved.
Blackberry ingestion has been demonstrated to attenuate brain degenerative processes in rodents with the benefits ascribed to the (poly)phenolic components. The aim of this work was to assess the efficacy of blackberry polyphenolics in a neurodegeneration cell model before and after simulated gastrointestinal digestion.
Digested blackberry metabolites protected neuroblastoma cells from H2O2-induced death at low, non-toxic levels that approach physiologically-relevant serum concentrations. However, the original extracts were not protective even at fivefold higher concentrations. This potentiation may reflect alterations in the polyphenolic composition caused by the digestion procedure, as detected by liquid-chromatography-mass spectrometric analysis. This protection was not caused by modulation of the intracellular antioxidant capacity or through alteration of glutathione levels, although the original extract influenced both of these parameters. This work reinforces the importance of evaluating digested metabolites in disease cell models and highlights the possible involvement of other mechanisms beyond antioxidant systems.
The modified release of active substances such as chlorzoxazone from matrix tablets, based on Kollidon
SR and chitosan, depends both on the drug solubility in the dissolution medium and on the matrix ...composition. The aim of this study is to obtain some new oral matrix tablet formulations, based on Kollidon
SR and chitosan, in order to optimize the low-dose oral bioavailability of chlorzoxazone, a non-steroidal anti-inflammatory drug of class II Biopharmaceutical Classification System. Nine types of chlorzoxazone matrix tablets were obtained using the direct compression method by varying the components ratio as 1:1, 1:2, and 1:3 chlorzoxazone/excipients, 20-40 w/w % Kollidon
SR, 3-7 w/w % chitosan while the auxiliary substances: Aerosil
1 w/w %, magnesium stearate 0.5 w/w % and Avicel
up to 100 w/w % were kept in constant concentrations. Pharmaco-technical characterization of the tablets included the analysis of flowability and compressibility properties (flow time, friction coefficient, angle of repose, Hausner ratio, and Carr index), and pharmaco-chemical characteristics (such as mass and dose uniformity, thickness, diameter, mechanical strength, friability, softening degree, and in vitro release profiles). Based on the obtained results, only three matrix tablet formulations (F1b, F2b, and F3b, containing 30 w/w % KOL and 5 w/w % CHT, were selected and further tested. These formulations were studied in detail by Fourier-transform infrared spectrometry, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. The three formulations were comparatively studied regarding the release kinetics of active substances using in vitro release testing. The results were analyzed by fitting into four representative mathematical models for the modified-release oral formulations. In vitro kinetic study revealed a complex mechanism of release occurring in two steps of drug release, the first step (0-2 h) and the second (2-36 h). Two factors were calculated to assess the release profile of chlorzoxazone: f1-the similarity factor, and f2-the factor difference. The results have shown that both Kollidon
SR and chitosan may be used as matrix-forming agents when combined with chlorzoxazone. The three formulations showed optima pharmaco-technical properties and in vitro kinetic behavior; therefore, they have tremendous potential to be used in oral pharmaceutical products for the controlled delivery of chlorzoxazone. In vitro dissolution tests revealed a faster drug release for the F2b sample.
Theoretical models, numerical simulations, and experimental tests for determining surges transferred between the windings of transformers subjected to lightning impulse are addressed. Considering the ...surges transmitted in the transformer windings have inductive and capacitive components, the proposed model is focused on five aspects: 1) voltage transmission by electromagnetic induction; 2) surge transferred in the transformer windings by capacitive coupling; 3) oscillating component of the voltage transferred between the windings; 4) voltage transferred between the primary and secondary windings; and 5) voltage transferred to the tertiary winding. The maximum transferred voltage is analytically determined. The simulation relies on the Math Script RT Module. Experimental tests were performed on two types of transformers. For the first one (type TTUS-ONAN, 50/67 MVA, 132/13.8/6.6 kV, Ynyn0d1 connection), the maximum voltage between the medium-voltage (MV) winding and ground, in case of a 200 V impulse applied to the high-voltage winding, is around 20.3 V; the voltage transferred to the tertiary winding reaches 8.1 V. For the second type (type TTUS-ONAN, 54/73 MVA, 110/15/6.6 kV, Ynyn0d1 connection), the voltage transferred to the MV winding reaches 21.1 V; the voltage transferred to the tertiary winding is 11.9 V. The laboratory tests validate the proposed analytical and simulation model.
In March 2010, Brazil introduced the ten-valent pneumococcal conjugate vaccine (PCV10), which was licensed based on non-inferiority of immunological correlates of protection compared with the ...seven-valent vaccine. The schedule comprised three primary doses at ages 2 months, 4 months, and 6 months, and a booster dose at age 12 months. A single catch-up dose was offered for children aged 12-23 months at the time of introduction. We assessed PCV10 effectiveness against invasive pneumococcal disease in Brazilian children.
Invasive pneumococcal disease, defined as isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid, or another normally sterile site, was identified in children age-eligible for at least one PCV10 dose through laboratory-based and hospital-based surveillance in ten states in Brazil from March 1, 2010, until Dec 31, 2012. We aimed to identify four age-matched and neighbourhood-matched controls for each case. We used conditional logistic regression and calculated PCV10 effectiveness as (1-adjusted matched odds ratio) × 100% for vaccine-type and vaccine-related serotypes (ie, in the same serogroup as a vaccine serotype).
In 316 cases (median age 13·2 months, range 2·6-53·1) and 1219 controls (13·3 months, 2·6-53·1), the adjusted effectiveness of an age-appropriate PCV10 schedule was 83·8% (95% CI 65·9-92·3) against vaccine serotypes, and 77·9% (41·0-91·7) against vaccine-related serotypes. Serotype-specific effectiveness was shown for the two most common vaccine serotypes-14 (87·7%, 60·8-96·1) and 6B (82·8%, 23·8-96·1)-and serotype 19A (82·2%, 10·7-96·4), a serotype related to vaccine serotype 19F. A single catch-up dose in children aged 12-23 months was effective against vaccine-type disease (68·0%, 17·6-87·6). No significant effectiveness was shown against non-vaccine serotypes for age-appropriate or catch-up schedules.
In the routine immunisation programme in Brazil, PCV10 prevents invasive disease caused by vaccine serotypes. PCV10 might provide cross-protection against some vaccine-related serotypes.
Brazilian Ministry of Health, Pan-American Health Organization, and US Centers for Disease Control and Prevention.
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