Bacterial adhesins are cell-surface proteins that anchor to the cell wall of the host. The first stage of infection involves the specific attachment to fibrinogen (Fg), a protein found in human blood. This attachment allows bacteria to colonize tissues causing diseases such as endocarditis. The study of this family of proteins is hence essential to develop new strategies to fight bacterial infections. In the case of the Gram-positive bacterium Staphylococcus aureus, there exists a class of adhesins known as microbial surface components recognizing adhesive matrix molecules (MSCRAMMs). Here, we focus on one of them, the clumping factor A (ClfA), which has been found to bind Fg through the dock-lock-latch mechanism. Interestingly, it has recently been discovered that MSCRAMM proteins employ a catch-bond to withstand forces exceeding 2 nN, making this type of interaction as mechanically strong as a covalent bond. However, it is not known whether this strength is an evolved feature characteristic of the bacterial protein or is typical only of the interaction with its partner. Here, we combine single-molecule force spectroscopy, biophysical binding assays, and molecular simulations to study the intrinsic mechanical strength of ClfA. We find that despite the extremely high forces required to break its interactions with Fg, ClfA is not by itself particularly strong. Integrating the results from both theory and experiments we dissect contributions to the mechanical stability of this protein.
Coagulase , Fibrinogen , Staphylococcus aureus , Staphylococcus aureus/metabolism , Staphylococcus aureus/chemistry , Coagulase/metabolism , Coagulase/chemistry , Fibrinogen/chemistry , Fibrinogen/metabolism , Protein Binding , Adhesins, Bacterial/metabolism , Adhesins, Bacterial/chemistry , Humans , Protein Stability
Protein mechanical stability determines the function of a myriad of proteins, especially proteins from the extracellular matrix. Failure to maintain protein mechanical stability may result in diseases and disorders such as cancer, cardiomyopathies, or muscular dystrophy. Thus, developing mutation-free approaches to enhance and control the mechanical stability of proteins using pharmacology-based methods may have important implications in drug development and discovery. Here, we present the first approach that employs computational high-throughput virtual screening and molecular docking to search for small molecules in chemical libraries that function as mechano-regulators of the stability of human cluster of differentiation 4, receptor of HIV-1. Using single-molecule force spectroscopy, we prove that these small molecules can increase the mechanical stability of CD4D1D2 domains over 4-fold in addition to modifying the mechanical unfolding pathways. Our experiments demonstrate that chemical libraries are a source of mechanoactive molecules and that drug discovery approaches provide the foundation of a new type of molecular function, that is, mechano-regulation, paving the way toward mechanopharmacology.
CD4 Antigens , Drug Discovery , Small Molecule Libraries , Humans , CD4 Antigens/metabolism , CD4 Antigens/chemistry , Drug Discovery/methods , High-Throughput Screening Assays/methods , HIV-1/metabolism , HIV-1/chemistry , Molecular Docking Simulation , Protein Stability , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology
Postpartum haemorrhage (PPH) is a significant cause of maternal mortality globally, necessitating prompt and efficient management. This review provides a comprehensive exploration of endovascular treatment dimensions for both primary and secondary PPH, with a focus on uterine atony, trauma, placenta accreta spectrum (PAS), and retained products of conception (RPOC). Primary PPH, occurring within 24 h, often results from uterine atony in 70% of causes, but also from trauma, or PAS. Uterine atony involves inadequate myometrial contraction, addressed through uterine massage, oxytocin, and, if needed, mechanical modalities like balloon tamponade. Trauma-related PPH may stem from perineal injuries or pseudoaneurysm rupture, while PAS involves abnormal placental adherence. PAS demands early detection due to associated life-threatening bleeding during delivery. Secondary PPH, occurring within 24 h to 6 weeks postpartum, frequently arises from RPOC. Medical management may include uterine contraction drugs and hemostatic agents, but invasive procedures like dilation and curettage (D&C) or hysteroscopic resection may be required.Imaging assessments, particularly through ultrasound (US), play a crucial role in the diagnosis and treatment planning of postpartum haemorrhage (PPH), except for uterine atony, where imaging techniques prove to be of limited utility in its management. Computed tomography play an important role in evaluation of trauma related PPH cases and MRI is essential in diagnosing and treatment planning of PAS and RPOC.Uterine artery embolization (UAE) has become a standard intervention for refractory PPH, offering a rapid, effective, and safe alternative to surgery with a success rate exceeding 85% (Rand T. et al. CVIR Endovasc 3:1-12, 2020). The technical approach involves non-selective uterine artery embolization with resorbable gelatine sponge (GS) in semi-liquid or torpedo presentation as the most extended embolic or calibrated microspheres. Selective embolization is warranted in cases with identifiable bleeding points or RPOC with AVM-like angiographic patterns and liquid embolics could be a good option in this scenario. UAE in PAS requires a tailored approach, considering the degree of placental invasion. A thorough understanding of female pelvis vascular anatomy and collateral pathways is essential for accurate and safe UAE.In conclusion, integrating interventional radiology techniques into clinical guidelines for primary and secondary PPH management and co-working during labour is crucial.
Functional gastrointestinal disorders (FGIDs) are classified as a combination of persistent gastrointestinal symptoms. The Rome IV criteria can elucidate several factors in the pathogenesis of FGIDs. The frequency of FGIDs can differ between clinical and nonclinical settings and between geographic regions. To determine the global prevalence of FGIDs in neonates and toddlers according to the Rome IV criteria. We included cohort and descriptive observational studies reporting the prevalence of FGIDs according to the Rome IV criteria in children aged 0-48 months. We searched the Medline, Embase, Lilacs, and CENTRAL databases from May 2016 to the present day. Furthermore, unpublished literature was searched to supplement this information. The Strengthening the Reporting of Observational Studies in Epidemiology statement was used to evaluate the risk of bias. A meta-analysis of the proportions was performed using MetaProp in R. The results are reported in forest plots. We identified and analyzed 15 studies comprising 48,325 participants. Six studies were conducted in Europe, three in Latin America, two in North America, and four in Asia. Most participants were 12-48 months old (61.0%) and were recruited from the community. The global prevalence of FGIDs was 22.0% (95% confidence interval, 15-31%). The most common disorder was functional constipation (9.0%), followed by infant regurgitation syndrome (8.0%). Its prevalence was higher in the Americas (28.0%). FGIDs, as defined by the Rome IV criteria, are present in 22% of children, and the most common primary disorder is functional constipation. A higher prevalence of FGIDs has been reported in America.
Introducción: La hipertensión arterial es una de las enfermedades con mayor preva-lencia en nuestro país. La prescripción de antagonistas del receptor de angiotensina tipo II, es uno los tratamientos más comunes; sin embargo, su dosis máxima efectiva es controversial. Objetivo: El objetivo del estudio fue caracterizar una población de una entidad promotora de salud en Colombia, que recibía para el manejo de la hipertensión arterial, una dosis de losartán mayor a 100 mg/día. Metodología: Se incluyó una base de prescripción de 3816 casos con hipertensión arterial, en manejo con losartán potásico a dosis superiores a 100 mg/día, con una muestra proporcional de 300 casos; en quienes se aplicó una alerta de dosis máxima (100 mg/día) en la prescripción. Se describió el perfil farmacoterapéutico, interacciones farmacológicas, cambios de dosificación y en las cifras de presión arterial. Para confirmar el efecto terapéutico de losartán potásico en control de cifras de presión arterial, se realizaron pruebas estadísticas (Tukey, Bonferroni). Resultados: De los 300 pacientes, 224 (74,6%) contaban con registro de presión arterial al inicio de la prescripción de losartán potásico a 100 mg/día; después de la intervención se logró reducción de dosis en 70 casos (23,3%). 76 casos (25,3%) no contaban con ningún paraclínico de seguimiento. Conclusión: No se encontró evidencia clínica o científica que justifique la prescripción de losartán con dosis mayores a 100 mg/día para el manejo de la hipertensión arterial esencial en nuestra población descrita.
SUMMARY Introduction: Hypertension is one of the most prevalent diseases in our country. Type II angiotensin receptor antagonists are one of the most common treatments; however, its maximum effective dose is controversial. Aim: The objective of study to characterize a population of a health promoting entity in Colombia, which received a dose of losartan greater than 100 mg/day for management of arterial hypertension. Methodology: The study included a prescription base of 3816 cases with arterial hypertension, in management with losartan potassium at doses higher than 100 mg/day, with a proportional sample of 300 cases; in whom a maximum dose alert (100 mg/day) was applied in prescription. Pharmacotherapeutic profile, drug interactions, dosage changes, and changes in blood pressure figures were described. To confirm therapeutic effect of losartan potassium in controlling blood pressure figures, statistical tests were performed (Tukey, Bonferroni). Results: Of the 300 patients, 224 (74.6%) had a blood pressure record at beginning of prescription of losartan potassium at 100 mg/day; after the intervention, a dose reduction was achieved in 70 cases (23.3%). 76 cases (25.3%) did not have any follow-up paraclinical. Conclusion: It was concluded that losartan potassium at doses greater than 100 mg/day did not show statistically significant differences for blood pressure control. We found insufficient clinical and scientific evidence to support the treatment with losartan more than 100 mg/day for hypertension in our population.
Introdução: A hipertensão arterial é uma das doenças mais prevalentes em nosso país. Os antagonistas do receptor de angiotensina tipo II são um dos tratamentos mais comuns; entretanto, sua dose máxima efetiva é controversa. Objetivo: Caracterizar uma população de uma entidade promotora de saúde na Colômbia, que receberam uma dose de losartana superior a 100 mg/dia para tratamento de hipertensão. Metodologia: O estudo incluiu uma base de prescrição de 3816 casos com hipertensão arterial, em manejo com losartana potássica em doses maiores superior a 100 mg/ dia, com amostra proporcional de 300 casos; em quem um máximo alerta de dose (100 mg/dia) foi aplicado na prescrição. Perfil farmacoterapêutico, interações medicamentosas, alterações de dosagem e alterações nos valores da pressão arterial foram descrito. Para confirmar o efeito terapêutico da losartana potássica no controle do sangue valores pressóricos, foram realizados testes estatísticos (Tukey, Bonferroni). Resultados: De dos 300 pacientes, 224 (74,6 %) tinham registro de pressão arterial no início da prescrição de losartana potássica a 100 mg/dia; após a intervenção, uma redução da dose foi alcançada em 70 casos (23,3 %). 76 casos (25,3 %) não tiveram seguimento paraclínico. Conclusão: Concluiuse que a losartana potássica em doses maiores superior a 100 mg/dia não apresentou diferenças estatisticamente significativas para a pressão arterial ao controle. Encontramos evidências clínicas e científicas insuficientes para apoiar o tratamento com losartana mais de 100 mg/dia para hipertensão em nossa população.
OBJECTIVE: To determine the prevalence of functional gastrointestinal disorders (FGIDs) in children according to Rome IV criteria. METHODS: We included cohorts and observational descriptive studies, including information for the prevalence of FGIDs according to Rome IV criteria in children 4 to 18 years old. We searched the MEDLINE (Ovid), EMBASE, LILACS, and CENTRAL databases from May 2016 to nowadays. Gray literature and other databases were also consulted. The risk of bias was assessed using the STROBE Statement. The results were reported in forest plots of the estimated effects of the included studies with a 95% confidence interval (95%CI). RESULTS: We included 14 studies involving a total of 17427 participants. Three studies were conducted in Europe, two in North America, and nine in Latin America. Most studies were school-based (n=14670, 84.18%), participants were mostly female (55.49%), white (51.73%), 8 to 18 years old (77.64%), and assisted to a public school (81.53%). Thirteen studies used the Questionnaire on Pediatric Gastrointestinal Symptoms (QPGS-RIV) to assess FGIDs. We found a global prevalence for FGIDs of 23% (95%CI 21-25%, I2 99%). Main disorders were functional constipation (FC) with 12% (95%CI 11-15%) followed by functional dyspepsia (FD) (5%, 95%CI 11-15%) and irritable bowel syndrome (IBS) (3%, 95%CI 2-4%). The prevalence of FGIDs was higher in the Americas, representing 23.67% (95%CI 21.2-26.2%, I2 91.3%). CONCLUSION: FGIDs are present in one of four children and adolescents, representing a common condition in this age group the central disorders were FC, FD, and IBS.
Dyspepsia , Gastrointestinal Diseases , Irritable Bowel Syndrome , Adolescent , Child , Child, Preschool , Constipation/diagnosis , Dyspepsia/diagnosis , Female , Gastrointestinal Diseases/epidemiology , Humans , Irritable Bowel Syndrome/epidemiology , Male , Prevalence , Rome , Surveys and Questionnaires
ABSTRACT Objective: To determine the prevalence of functional gastrointestinal disorders (FGIDs) in children according to Rome IV criteria. Methods: We included cohorts and observational descriptive studies, including information for the prevalence of FGIDs according to Rome IV criteria in children 4 to 18 years old. We searched the MEDLINE (Ovid), EMBASE, LILACS, and CENTRAL databases from May 2016 to nowadays. Gray literature and other databases were also consulted. The risk of bias was assessed using the STROBE Statement. The results were reported in forest plots of the estimated effects of the included studies with a 95% confidence interval (95%CI). Results: We included 14 studies involving a total of 17427 participants. Three studies were conducted in Europe, two in North America, and nine in Latin America. Most studies were school-based (n=14670, 84.18%), participants were mostly female (55.49%), white (51.73%), 8 to 18 years old (77.64%), and assisted to a public school (81.53%). Thirteen studies used the Questionnaire on Pediatric Gastrointestinal Symptoms (QPGS-RIV) to assess FGIDs. We found a global prevalence for FGIDs of 23% (95%CI 21-25%, I2 99%). Main disorders were functional constipation (FC) with 12% (95%CI 11-15%) followed by functional dyspepsia (FD) (5%, 95%CI 11-15%) and irritable bowel syndrome (IBS) (3%, 95%CI 2-4%). The prevalence of FGIDs was higher in the Americas, representing 23.67% (95%CI 21.2-26.2%, I2 91.3%). Conclusion: FGIDs are present in one of four children and adolescents, representing a common condition in this age group the central disorders were FC, FD, and IBS.
RESUMO Objetivo: Determinar a prevalência de distúrbios gastrointestinais funcionáis (DGF) em crianças de acordo com os critérios de Roma IV. Métodos: Incluímos coortes e estudos observacionais descritivos, incluindo informações para a prevalência de DGF de acordo com os critérios de Roma IV em crianças de 4 a 18 anos. Pesquisamos nas bases de dados MEDLINE (Ovid), EMBASE, LILACS e CENTRAL de maio de 2016 até os dias atuais. A literatura cinzenta e outras bases de dados também foram consultadas. O risco de viés foi avaliado usando a Declaração STROBE. Os resultados foram relatados em parcelas florestais dos efeitos estimados dos estudos incluídos com um intervalo de confiança de 95% (95%IC). Resultados: Foram incluídos 14 estudos envolvendo um total de 17.427 participantes. Três estudos foram realizados na Europa, dois na América do Norte e nove na América Latina. A maioria dos estudos foi de base escolar (n=14.670, 84,18%), os participantes eram em sua maioria do sexo feminino (55,49%), brancos (51,73%), de 8 a 18 anos (77,64%) e atendidos em escola pública (81,53%). Treze estudos usaram o Questionário de Sintomas Gastrointestinais Pediátricos (QPGS-RIV) para avaliar DGF. Encontramos uma prevalência global de DGF de 23% (95%IC 21-25%, I2 99%). Os principais distúrbios foram constipação funcional (CF) com 12% (95%IC 11-15%) seguido de dispepsia funcional (DF) (5%, 95%IC 11-15%) e síndrome do intestino irritável (SII) (3%, 95%IC 2-4%). A prevalência de DGF foi maior nas Américas, representando 23,67% (95%IC 21, 2-26,2%, I2 91,3%). Conclusão: DGF estão presentes em uma de quatro crianças e adolescentes, representando uma condição comum nessa faixa etária. Os distúrbios centrais foram CF, DF e SII.
In this work, a portable and disposable screen-printed electrode-based platform for CdS QDs electrochemiluminescence (ECL) detection is presented. CdS QDs were synthesized in aqueous media and placed on top of carbon electrodes by drop casting. The CdS QDs spherical assemblies consisted of nanoparticles about 4 nm diameters and served as ECL sensitizers to enzymatic assays. The nanoparticles were characterized by optical techniques, TEM and XPS. Besides, the electrode modification process was optimized and further studied by SEM and confocal microscopy. The ECL emission from CdS QDs was triggered with H2O2 as cofactor and enzymatic assays were employed to modulate the CdS QDs ECL signal by blocking the surface or generating H2O2 in situ. Thiol-bearing compounds such as thiocholine generated through the hydrolysis of acetylthiocholine by acetylcholinesterase (AChE) interacted with the surface of CdS QDs thus blocking the ECL. The biosensor showed a linear range up to 5 mU mL-1 and a detection limit of 0.73 mU mL-1 for AChE. Moreover, the inhibition mechanism of the enzyme was studied by using 1,5-bis-(4-allyldimethylammonium-phenyl)pentan-3-one dibromide with a detection limit of 79.22 nM. Furthermore, the natural production of H2O2 from the oxidation of methanol by the action of alcohol oxidase was utilized to carry out the ECL process. This enzymatic assay presented a linear range up to 0.5 mg L-1 and a detection limit of 61.46 µg L-1 for methanol. The reported methodology shows potential applications for the development of sensitive and easy to hand biosensors and was applied to the determination of AChE and methanol in real samples.
Biosensing Techniques , Cadmium Compounds , Quantum Dots , Carbon , Electrochemical Techniques , Electrodes , Hydrogen Peroxide , Luminescent Measurements
Cisplatin treatment confers the relative resistance to MCF-7 cells as compared to other breast cancer cell lines. One principal reason is that chemotherapeutic agents induce autophagy in these cells to inhibit apoptosis. Binding immunoglobulin protein (BiP), a master regulator of unfolded protein response (UPR) and 14-3-3ζ are two critical proteins upregulated in breast cancer rendering resistance to anticancer drugs. They also play pivotal roles in autophagy with crosstalk with the apoptotic pathways of UPR through certain regulators. Thus, BiP and 14-3-3ζ were selected as the candidate targets to enhance cell death and apoptosis. First, cisplatin resistance was induced and determined by MTT assay and qPCR in MCF-7 cells. Then, the apoptosis axis of UPR was activated by knocking down either BiP or 14-3-3ζ and overactivated by co-knockdown of BiP and 14-3-3ζ. Apoptosis assays were performed using flow cytometry, TUNEL assays utilized confocal microscopy followed by western blot analysis and caspase-3 and JNK activities were investigated to assess the outcomes. Finally, an autophagy assay followed by western blotting was performed to study the effects of co-knockdown genes on cell autophagy in the presence and absence of cisplatin. The present data indicated the enhancement of cisplatin sensitivity in MCF-7 cells co-knocked down in BiP and 14-3-3ζ compared with either gene knockdown. Upregulation of JNK and cleaved-PARP1 protein levels as well as caspase-3 and JNK overactivation confirmed the results. A marked attenuation of autophagy and Beclin1 as well as ATG5 downregulation were detected in co-knockdown cells compared to knockdown with either BiP or 14-3-3ζ. Cisplatin sensitization of MCF-7 cells through double-knockdown of BiP and 14-3-3ζ highlights the potential of targeting UPR and autophagy factors to increase the effect of chemotherapy.
14-3-3 Proteins/metabolism , Breast Neoplasms/drug therapy , Cisplatin/pharmacology , Drug Resistance, Neoplasm/genetics , Heat-Shock Proteins/metabolism , 14-3-3 Proteins/genetics , Apoptosis/drug effects , Apoptosis/genetics , Autophagy/drug effects , Autophagy/genetics , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , Cisplatin/therapeutic use , Endoplasmic Reticulum Chaperone BiP , Female , Gene Knockdown Techniques , Heat-Shock Proteins/genetics , Humans , MCF-7 Cells , Up-Regulation
Synthesis of atomic nanoclusters (NCs) using proteins as a scaffold has attracted great attention. Usually, the synthetic conditions for the synthesis of NCs stabilized with proteins require extreme pH values or temperature. These harsh reaction conditions cause the denaturation of the proteins and end up in the loss of their biological functions. Until now, there are no examples of the use of antibodies as NC stabilizers. In this work, we present the first method for the synthesis of catalytic NCs that uses antibodies for the stabilization of NCs. Anti-BSA IgG was used as a model to demonstrate that it is possible to use an antibody as a scaffold for the synthesis of semiconductor and metallic NCs with catalytic properties. The synthesis of antibodies modified with NCs is carried out under nondenaturing conditions, which do not affect the antibody structure. The resulting antibodies still maintain the affinity for target antigens and protein G. The catalytic properties of the anti-BSA IgG modified with NCs can be used to the quantification of bovine serum albumin (BSA) in a direct sandwich enzyme-linked immunosorbent assay (ELISA).
Antibodies/chemistry , Biological Assay/methods , Catalysis , Enzyme-Linked Immunosorbent Assay , Gold/chemistry , Immunoassay , Metal Nanoparticles/chemistry , Serum Albumin, Bovine/chemistry
A method is presented for sensitive determination of thrombin activity. It is based on (a) the interaction between fibrinogen after activation with thrombin, and (b) an enzymatic amplification step consisting of in-situ growth of CdS quantum dots (QDs). Fibrinogen is immobilized on the surface of the wells of a microplate and then incubated with a mixture of biotinylated fibrinogen and thrombin. Thrombin activates immobilized fibrinogen and free biotinylated fibrinogen. This leads to the formation of insoluble biotinylated fibrin that remains bound on the surface of the wells. Afterwards, the samples are incubated with avidin-labeled alkaline phosphatase (ALP) which binds to biotinylated fibrin. ALP hydrolyzes the substrate p-nitrophenyl phosphate (pNPP) under formation of phosphate ions which stabilize CdS QDs that are grown in-situ from cadmium(II) and sulfide. The generation of fibrin is correlated with the activity of thrombin. Increased thrombin concentration results in increased fluorescence that can be measured at excitation/emission wavelengths of 300/510 nm. The introduction of such an amplification step (the enzyme-triggered growth of QDs) allows for the quantification of thrombin in the picomolar concentration range, with a linear response up to 2.5 pM and a detection limit of 0.05 pM. The method was applied to the determination of thrombin activity in human plasma and of the thrombin inhibitor argatroban. Graphical abstract Schematic representation of a fluorometric method for determination of thrombin activity in the picomolar concentration range based on the interaction between fibrinogen after activation with thrombin, and an enzymatic amplification step consisting of in-situ growth of CdS quantum dots (CdS QD).
Cadmium Compounds/chemistry , Fluorometry , Quantum Dots/chemistry , Sulfides/chemistry , Thrombin/analysis , Thrombin/metabolism , Fibrinogen/analysis , Fibrinogen/metabolism , Humans , Particle Size , Surface Properties
Methanol is a poison which is frequently discovered in alcoholic beverages. Innovative methods to detect methanol in alcoholic beverages are being constantly developed. We report for the first time a new strategy for the detection of methanol using fluorescence spectroscopy and photoelectrochemical (PEC) analysis. The analytical system is based on the oxidation of cysteine (CSH) with hydrogen peroxide (H2O2) enzymatically generated by alcohol oxidase (AOx). H2O2 oxidizes capping agent CSH, modulating the growth of CSH-stabilized cadmium sulphide quantum dots (CdS QDs). Disposable screen-printed carbon electrodes (SPCEs) modified with a conductive osmium polymer (Os-PVP) complex were employed to quantify resulting CdS QDs. This polymer facilitates the "wiring" of in situ enzymatically generated CdS QDs, which photocatalyze oxidation of 1-thioglycerol (TG), generating photocurrent as the readout signal. Likewise, we proved that our systems did not suffer from interference by ethanol. The PEC assays showed better sensitivity than conventional methods, covering a wide range of potential applications for methanol quantification.
Alcohol Oxidoreductases/chemistry , Alcoholic Beverages/analysis , Biosensing Techniques/methods , Cadmium Compounds/chemistry , Methanol/analysis , Pichia/enzymology , Quantum Dots/chemistry , Sulfides/chemistry , Cysteine/chemistry , Electrochemical Techniques/methods , Enzymes, Immobilized/chemistry , Hydrogen Peroxide/chemistry , Limit of Detection , Oxidation-Reduction
RESUMEN El síndrome de Cohen (SC) es una enfermedad genética rara, con herencia autosómica recesiva. Se origina por daños en el gen VPS13B, locus 8q22-q23. El fenotipo característico consiste en discapacidad intelectual, microcefalia, facies dismórfica, anormalidades oftalmológicas, obesidad central e hipotonía. Solo se han publicado aproximadamente 150 casos, la mayoría de origen finlandés. Reportamos el caso de un preescolar con talla baja, craneosinostosis, facies dismórfica, hipotonía y retraso del desarrollo psicomotor a quien se le diagnosticó SC por medio de Hibridación Genómica Comparativa por microarreglos (HGCm), que mostró una deleción en homocigosis de 0.153 Mb en 8q22.2 incluyendo el gen VPS13B, OMIM #216550. Con esta publicación contribuimos al conocimiento epidemiológico de un síndrome genético infrecuente, y mostramos el aporte de la HGCm al diagnóstico etiológico de pacientes con discapacidad intelectual inexplicada, retardo del desarrollo psicomotor, problemas del lenguaje, autismo y anomalías congénitas múltiples.
SUMMARY Cohen syndrome (CS) is an uncommon autosomal recessive genetic disorder attributed to damage on VPS13B gene, locus 8q22-q23. Characteristic phenotype consists of intelectual disability, microcephaly, facial dysmorphism, ophthalmic abnormalities, truncal obesity and hipotony. Worldwide, around 150 cases have been published, mostly in Finish patients. We report the case of a 3 year-old male, with short height, craniosynostosis, facial dysmorphism, hipotony, and developmental delay. He was diagnosed with Cohen syndrome using Microarray Comparative Genomic Hibridization (aCGH) that showed homozygous deletion of 0.153 Mb on 8q22.2 including VPS13B gene, OMIM #216550. With this report we contribute to enlarge epidemiological databases on an uncommon genetic disorder. Besides, we illustrate on the contribution of aCGH to the etiological diagnosis of patients with unexplained intellectual disability, delayed psychomotor development, language difficulties, autism and multiple congenital anomalies.
RESUMO A síndrome de Cohen (SC) é uma doenças genética rara, com herança autossômica recessiva. Se origina por danos no gene VPS13B, locus 8q22-q23. O fenótipo característico consiste em deficiência intelectual, microcefalia, faces dismórfica, anormalidades oftalmológicas, obesidade central e hipotonia. Só se há publicado aproximadamente 150 casos, a maioria de origem finlandês. Reportamos o caso de um pré-escolar com estatura baixa, craniossinostose, faces dismórfica, hipotonia e retraso do desenvolvimento psicomotor a quem se lhe diagnosticou SC por meio de Hibridação Genômica Comparativa por microarranjos (HGCm), que mostrou uma deleção em homozigoto de 0.153 Mb em 8q22.2 incluindo o gene VPS13B, OMIM #216550. Com esta publicação contribuímos ao conhecimento epidemiológico de uma síndrome genética infrequente, e mostramos o aporte da HGCm ao diagnóstico etiológico de pacientes com deficiência intelectual inexplicada, atraso do desenvolvimento psicomotor, problemas da linguagem, autismo e anomalias congénitas múltiplas.
Humans , Male , Child , Rare Diseases , Comparative Genomic Hybridization , Genetics
We discovered that copper ions (Cu2+) catalyze the oxidation of cysteine (CSH) by oxygen (O2) to modulate the growth of CSH-capped cadmium sulfide (CdS) nanoparticles (NPs). This new chemical process was applied to sensitive fluorogenic and photoelectrochemical (PEC) detection of Cu2+ ions in real samples of mineral and tap water using the photocatalytic activity of the resulting NPs. Disposable screen-printed electrodes (SPCEs) modified with electroactive polyvinylpyridine bearing osmium complex (Os-PVP) by cyclic voltammetry (CV) were employed for PEC analytical system. CdS NPs formed during the assay photocatalyze oxidation of 1-thioglycerol (TG) upon application of 0.3 V vs. Ag/AgCl to SPCEs. Os-PVP complex mediated the electron transfer between the electrode surface and CdS NPs. We proved that our assays did not suffer from interference from other ions accompanying Cu2+ and the sensitivity of our assays covers the European Union standard limit of Cu2+ ions in drinking water.
Copper/analysis , Drinking Water/analysis , Quantum Dots , Cadmium Compounds , Drinking Water/standards , Electrochemical Techniques , Electrodes , Nanoparticles , Osmium , Sulfides
Abstract The cri-du-chat syndrome is caused by a deletion on the short arm of chromosome number 5. The size of genetic material loss varies from the 5p15.2 region only to the whole arm. Prevalence rates range between 1:15000 and 1:50000 live births. Diagnosis is suspected on infants with a high-pitched (cat-like) cry, facial dysmorfism, hypotonia and delayed psychomotor development. In adults, phenotypic findings are less specific. It is confirmed through high-resolution G-banding karyotype, fluorescent in situ hybridization or microarray-based comparative genomic hybridization (a-CGH). The following is the case report of a 21-year-old female patient with severe mental retardation and trichotillomania, who does not control sphincters and does not bathe or eat by herself. Her communication is based only on sounds and dysmorphic facies. The G-band karyotype reported is 46, XX. a-CGH shows 18.583Mb interstitial microdeletion in 5p15.33p14.3, including the cri-du-chat critical region. In children or adults with unexplained mental retardation and normal karyotype results (like this case), an a-CGH should be performed to make an etiological diagnosis, establish the prognosis, order additional medical tests and specific treatments, and offer appropriate genetic counseling.
Resumen El síndrome de cri du chat o del maullido de gato es causado por una deleción en el brazo corto del cromosoma 5; el tamaño de la pérdida de material genético varía desde solo la región 5p15.2 hasta el brazo entero. La prevalencia va desde 1 por 15 000 habitantes hasta 1 por 50 000 habitantes. Su diagnóstico se puede confirmar con cariotipo con bandas G de alta resolución, hibridación fluorescente in situ o hibridación genómica comparativa por microarreglos (HGCm); este se sospecha en infantes con un llanto similar al maullido de un gato, fascies dismórficas, hipotonía y retardo del desarrollo psicomotor; sin embargo, en los adultos afectados los hallazgos fenotípicos son menos específicos. Se presenta el caso de una mujer de 21 años con retardo mental severo y tricotilomanía, que no controla esfínteres y no se baña ni come sola; solo emite ruidos y tiene facies dismórficas. El cariotipo de bandas G es reportado 46, XX y la HGCm muestra microdeleción de 18.583Mb en 5p15.33p14.3, incluyendo región crítica de cri du chat. En pacientes de este tipo se debe realizar HGCm para hacer un diagnóstico etiológico, establecer un pronóstico, ordenar pruebas médicas adicionales y tratamientos específicos y realizar la adecuada asesoría genética.
Electrochemical detection strategies employing semiconductor quantum dots (QDs) open up new opportunities for highly sensitive detection of biological targets. We designed a new assay based on microbead linked enzymatic generation of CdS QDs (Microbead QD-ELISA) and employed it in optical and electrochemical affinity assays for the cancer biomarker superoxide dismutase 2 (SOD2). Biotinylated antibodies against SOD2 were immobilized on the surface of polyvinyl chloride microbeads bearing streptavidin. In order to prevent any non-specific adsorption the microbeads were further blocked with bovine serum albumin. The analyte, SOD2 was captured on microbeads and labeled with alkaline phosphatase-conjugated antibody linked with mouse antibody against SOD2. Hydrolysis of para-nitrophenylphosphate by immobilized alkaline phosphatase triggered the rapid formation of phosphate-stabilized CdS QDs on the surface of microbeads. The resulting semiconductor nanoparticles were detected by fluorescence spectroscopy, microscopy, and square-wave voltammetry (SWV). The electrochemical assay based on the detection with square-wave voltammograms of Cd2+ ions originating from immobilized CdS QDs showed linearity up to 45 ng mL-1, and the limit of SOD2 detection equal to 0.44 ng mL-1 (1.96 × 10-11 M). This detection limit is lower by 2 orders of magnitude in comparison with that of other previously published assays for superoxide dismutase. The electrochemical assay was validated with HepG2 (Human hepatocellular carcinoma) cell lysate containing SOD2.
Quantum Dots , Alkaline Phosphatase , Animals , Enzyme-Linked Immunosorbent Assay , Hep G2 Cells , Humans , Limit of Detection , Mice , Microspheres
The anisotropic morphology of gold nanorods (AuNRs) has been shown to lead to nonuniform ligand distribution and preferential etching through their tips. We have recently demonstrated that this effect can be achieved by biocatalytic oxidation with hydrogen peroxide, catalyzed by the enzyme horseradish peroxidase (HRP). We report here that modification of AuNRs with thiol-containing organic molecules such as glutathione and thiocholine hinders enzymatic AuNR etching. Higher concentrations of thiol-containing molecules in the reaction mixture gradually decrease the rate of enzymatic etching, which can be monitored by UV-vis spectroscopy through changes in the AuNR longitudinal plasmon band. This effect can be applied to develop novel optical assays for acetylcholinesterase (AChE) activity. The biocatalytic hydrolysis of acetylthiocholine by AChE yields thiocholine, which prevents enzymatic AuNR etching in the presence of HRP. Additionally, the same bioassay can be used for the detection of nanomolar concentrations of AChE inhibitors such as paraoxon and galanthamine.
Nanotubes , Acetylcholinesterase , Biosensing Techniques , Cholinesterase Inhibitors , Colorimetry , Gold
We report an innovative photoelectrochemical process (PEC) based on graphite electrode modified with electroactive polyvinylpyridine bearing osmium complex (Os-PVP). The system relies on the in situ enzymatic generation of CdS quantum dots (QDs). Alkaline phosphatase (ALP) catalyzes the hydrolisis of sodium thiophosphate (TP) to hydrogen sulfide (H2S) which in the presence Cd(2+) ions yields CdS semiconductor nanoparticles (SNPs). Irradiation of SNPs with the standard laboratory UV-illuminator (wavelength of 365 nm) results in photooxidation of 1-thioglycerol (TG) mediated by Os-PVP complex on the surface of graphite electrode at applied potential of 0.31 V vs. Ag/AgCl. A novel immunoassay based on specific enzyme linked immunosorbent assay (ELISA) combined with the PEC methodology was developed. Having selected the affinity interaction between bovine serum albumine (BSA) with anti-BSA antibody (AB) as a model system, we built the PEC immunoassay for AB. The new assay displays a linear range up to 20 ngmL(-1) and a detection limit (DL) of 2 ngmL(-1) (S/N=3) which is lower 5 times that of the traditional chromogenic ELISA test employing p-nitro-phenyl phosphate (pNPP).
Alkaline Phosphatase/chemistry , Cadmium Compounds/analysis , Conductometry/instrumentation , Immunoassay/instrumentation , Metal Nanoparticles/analysis , Metal Nanoparticles/chemistry , Selenium Compounds/analysis , Biosensing Techniques/instrumentation , Enzymes, Immobilized/chemistry , Equipment Design , Equipment Failure Analysis , Graphite/chemistry , Metal Nanoparticles/ultrastructure , Photometry/instrumentation
It was found out that semiconductor CdS nanoparticles (NPs) are able to catalyze photooxidation of the well known chromogenic enzymatic substrate 3,3',5,5'-tetramethylbenzidine (TMB) by oxygen. The photocatalytical oxidation of TMB does not require hydrogen peroxide and its rate is directly proportional to the quantity of CdS NPs produced in situ through the interaction of Cd(2+) and S(2-) ions in an aqueous medium. This phenomenon was applied to development of colorimetric sensitive assays for glucose oxidase and glutathione reductase based on enzymatic generation of CdS NPs acting as light-powered catalysts. Sensitivity of the developed chromogenic assays was of the same order of magnitude or even better than that of relevant fluorogenic assays. The present approach opens the possibility for the design of simple and sensitive colorimetric assays for a number of enzymes using inexpensive and available TMB as a universal chromogenic compound.
Benzidines/chemistry , Biosensing Techniques/methods , Cadmium Compounds/chemistry , Glucose Oxidase/metabolism , Glutathione Reductase/metabolism , Quantum Dots/chemistry , Sulfides/chemistry , Blood Glucose/analysis , Catalysis , Colorimetry/methods , Enzyme Activation , Glutathione/blood , Limit of Detection , Oxidation-Reduction , Semiconductors , Spectrophotometry, Ultraviolet , Substrate Specificity , Ultraviolet Rays
This work demonstrates the use of the peroxidase-mimicking DNAzyme (peroxidase-DNAzyme) as general and inexpensive platform for development of fluorogenic assays that do not require organic fluorophores. The system is based on the affinity interaction between the peroxidase-DNAzyme bearing hairpin sequence and the analyte (DNA or low molecular weight molecule), which changes the folding of the hairpin structure and consequently the activity of peroxidase-DNAzyme. Hence, in the presence of the analyte the peroxidase-DNAzyme structure is disrupted and does not catalyze the aerobic oxidation of l-cysteine to cystine. Thus, l-cysteine is not removed from the system and the fluorescence of the assay increases due to the in situ formation of fluorescent CdS nanocrystals. The capability of the system as a platform for fluorogenic assays was demonstrated through designing model geno- and aptasensor for the detection of a tumor marker DNA and a low molecular weight analyte, adenosine 5'triphosphate (ATP), respectively.
Aptamers, Nucleotide/analysis , Cadmium Compounds/chemistry , DNA, Catalytic/metabolism , Molecular Mimicry , Nanostructures , Peroxidases/metabolism , Sulfides/chemistry , Base Sequence , DNA Primers , Molecular Structure , Oxidation-Reduction
