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1.
Chem Sci ; 15(25): 9582-9590, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38939159

ABSTRACT

Amines are centrally important motifs in medicinal chemistry and biochemistry, and indispensable intermediates and linchpins in organic synthesis. Despite their cross-disciplinary prominence, synthetic access to amine continues to rely on two-electron approaches based on reductions and additions of organometallic reagents, limiting their accessible chemical space and necessitating stepwise preassembly of synthetic precursors. We report herein a homogeneous photocatalytic tricomponent decarboxylative radical-mediated amine construction that enables modular access to α-branched secondary amines directly from the broad and structurally diverse chemical space of carboxylic acids in a tricomponent reaction with aldehydes and aromatic amines. Our studies reveal the key role of acridine photocatalysis acting in concert with copper and Brønsted acid catalytic processes in facilitating the previously inaccessible homogeneous photocatalytic reaction and provide a streamlined segue to a wide range of amines and nonproteinogenic α-amino acids.

2.
ACS Catal ; 14(9): 6973-6980, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38737399

ABSTRACT

Development of photocatalytic systems that facilitate mechanistically divergent steps in complex catalytic manifolds by distinct activation modes can enable previously inaccessible synthetic transformations. However, multimodal photocatalytic systems remain understudied, impeding their implementation in catalytic methodology. We report herein a photocatalytic access to thiols that directly merges the structural diversity of carboxylic acids with the ready availability of elemental sulfur without substrate preactivation. The photocatalytic transformation provides a direct radical-mediated segue to one of the most biologically important and synthetically versatile organosulfur functionalities, whose synthetic accessibility remains largely dominated by two-electron-mediated processes based on toxic and uneconomical reagents and precursors. The two-phase radical process is facilitated by a multimodal catalytic reactivity of acridine photocatalysis that enables both the singlet excited state PCET-mediated decarboxylative carbon-sulfur bond formation and the previously unknown radical reductive disulfur bond cleavage by a photoinduced HAT process in the silane-triplet acridine system. The study points to a significant potential of multimodal photocatalytic systems in providing unexplored directions to previously inaccessible transformations.

3.
Chem Sci ; 15(14): 5277-5283, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38577370

ABSTRACT

Chemodivergent construction of structurally distinct heterocycles from the same precursors by adjusting specific reaction parameters is an emergent area of organic synthesis; yet, understanding of the processes that underpin the reaction divergence is lacking, preventing the development of new synthetic methods by systematically harnessing key mechanistic effects. We describe herein cesium carbonate-promoted oxadiaza excision cross-coupling reactions of ß-ketoesters with 1,2,3-triazine 1-oxides that form pyridones in good to high yields, instead of the sole formation of pyridines when the same reaction is performed in the presence of other alkali metal carbonates or organic bases. The reaction can be further extended to the construction of synthetically challenging pyridylpyridones. A computational study comparing the effect of cesium and sodium ions in the oxadiaza excision cross-coupling reactions reveals that the cesium-coordinated species changes the reaction preference from attack at the ketone carbonyl to attack at the ester carbon due to metal ion-specific transition state conformational accommodation, revealing a previously unexplored role of cesium ions that may facilitate the development of chemodivergent approaches to other heterocyclic systems.

4.
Am J Trop Med Hyg ; 110(3): 491-496, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38295420

ABSTRACT

The threats from vector-borne pathogens transmitted by ticks place people (including deployed troops) at increased risk for infection, frequently contributing to undifferentiated febrile illness syndromes. Wild and domesticated animals are critical to the transmission cycle of many tick-borne diseases. Livestock can be infected by ticks, and serve as hosts to tick-borne diseases such as rickettsiosis. Thus, it is necessary to identify the tick species and determine their potential to transmit pathogens. A total of 1,493 adult ticks from three genera-Amblyomma, Hyalomma, and Rhipicephalus-were identified using available morphological keys and were pooled (n = 541) by sex and species. Rickettsia species were detected in 308 of 541 (56.9%) pools by genus-specific quantitative polymerase chain reaction assay (Rick17b). Furthermore, sequencing of the outer membrane protein A and B genes (ompA and ompB) of random samples of Rickettsia-positive samples led to the identification of Rickettsia aeschlimannii and Rickettsia africae with most R. africae DNA (80.2%) detected in pools of Amblyomma variegatum. We report the first molecular detection and identification of the rickettsial pathogens R. africae and R. aeschlimannii in ticks from Ghana. Our findings suggest there is a need to use control measures to prevent infections from occurring among human populations in endemic areas in Ghana. This study underscores the importance of determining which vector-borne pathogens are in circulation in Ghana. Further clinical and prevalence studies are needed to understand more comprehensively the clinical impact of these rickettsial pathogens contributing to human disease and morbidity in Ghana.


Subject(s)
Ixodidae , Rickettsia , Tick-Borne Diseases , Ticks , Animals , Adult , Humans , Ticks/microbiology , Ghana/epidemiology , Rickettsia/genetics , Tick-Borne Diseases/microbiology
5.
Chem Sci ; 14(46): 13384-13391, 2023 Nov 29.
Article in English | MEDLINE | ID: mdl-38033883

ABSTRACT

Sulfinamides are some of the most centrally important four-valent sulfur compounds that serve as critical entry points to an array of emergent medicinal functional groups, molecular tools for bioconjugation, and synthetic intermediates including sulfoximines, sulfonimidamides, and sulfonimidoyl halides, as well as a wide range of other S(iv) and S(vi) functionalities. Yet, the accessible chemical space of sulfinamides remains limited, and the approaches to sulfinamides are largely confined to two-electron nucleophilic substitution reactions. We report herein a direct radical-mediated decarboxylative sulfinamidation that for the first time enables access to sulfinamides from the broad and structurally diverse chemical space of carboxylic acids. Our studies show that the formation of sulfinamides prevails despite the inherent thermodynamic preference for the radical addition to the nitrogen atom, while a machine learning-derived model facilitates prediction of the reaction efficiency based on computationally generated descriptors of the underlying radical reactivity.

6.
Nat Commun ; 14(1): 6392, 2023 10 23.
Article in English | MEDLINE | ID: mdl-37872141

ABSTRACT

Invasive non-typhoidal Salmonella (iNTS) disease manifesting as bloodstream infection with high mortality is responsible for a huge public health burden in sub-Saharan Africa. Salmonella enterica serovar Typhimurium (S. Typhimurium) is the main cause of iNTS disease in Africa. By analysing whole genome sequence data from 1303 S. Typhimurium isolates originating from 19 African countries and isolated between 1979 and 2017, here we show a thorough scaled appraisal of the population structure of iNTS disease caused by S. Typhimurium across many of Africa's most impacted countries. At least six invasive S. Typhimurium clades have already emerged, with ST313 lineage 2 or ST313-L2 driving the current pandemic. ST313-L2 likely emerged in the Democratic Republic of Congo around 1980 and further spread in the mid 1990s. We observed plasmid-borne as well as chromosomally encoded fluoroquinolone resistance underlying emergences of extensive-drug and pan-drug resistance. Our work provides an overview of the evolution of invasive S. Typhimurium disease, and can be exploited to target control measures.


Subject(s)
Salmonella Infections , Salmonella typhimurium , Humans , Africa South of the Sahara/epidemiology , Drug Resistance, Microbial , Genomics , Salmonella Infections/epidemiology , Salmonella typhimurium/genetics
7.
Vector Borne Zoonotic Dis ; 23(2): 75-80, 2023 02.
Article in English | MEDLINE | ID: mdl-36763962

ABSTRACT

Background: Leishmaniasis is a parasitic disease that mostly affects populations in tropical and subtropical countries. In Ghana, cutaneous leishmaniasis (CL) is the most common form of the disease affecting communities of the Volta Region. Conventional parasitological method (microscopy) is the commonly used test for CL diagnosis in many endemic countries, but has low sensitivity in chronic cases. Therefore, there is a clear need for a sensitive and easy-to-use point-of-care diagnostic method like an isothermal recombinase polymerase amplification-lateral flow (RPA-LF) test, suitable for use in austere and low-resource settings for the identification of CL cases. This study compared the efficacy of RPA-LF test with quantitative PCR (qPCR) in detecting Leishmania in suspected CL cases from the Volta Region. Methods: Twenty-five participants between 5 and 14 years were enrolled in the study from whom a total of 26 samples were obtained. Lesion samples were collected using FTA® filter papers applied to ulcerated lesions for molecular diagnosis. DNA isolated from filter papers was used for both the RPA-LF test and qPCR. Results: Twenty-two participants (88%) presented with one or two ulcerated active lesions per individual, while the rest of them had plaques or dried lesions. Among the 26 samples, 19/26 (73%) had concordant results when comparing the two diagnostic methods. Conclusion: Data from this study suggest that the RPA-LF test can be used in addition to a conventional parasitological diagnostic test (microscopy) to detect CL cases in communities of the Volta Region.


Subject(s)
Leishmania , Leishmaniasis, Cutaneous , Animals , Leishmania/genetics , Recombinases/genetics , Ghana/epidemiology , Sensitivity and Specificity , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/veterinary , Nucleic Acid Amplification Techniques/methods , Nucleic Acid Amplification Techniques/veterinary , Leishmaniasis, Cutaneous/diagnosis , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Cutaneous/veterinary
8.
Article in English | MEDLINE | ID: mdl-36570094

ABSTRACT

Hookworm infection is caused by the blood-feeding hookworm gastrointestinal nematodes. Its harmful effects include anemia and retarded growth and are common in the tropics. A current control method involves the mass drug administration of synthetic drugs, mainly albendazole and mebendazole. There are however concerns of low efficacy and drug resistance due to their repeated and excessive use. Although, Necator americanus glutathione S-transferase 3 (Na-GST-3) is a notable target, using natural product libraries for computational elucidation of promising leads is underexploited. This study sought to use pharmacoinformatics techniques to identify compounds of natural origins with the potential to be further optimized as promising inhibitors. A compendium of 3182 African natural products together with five known helminth GST inhibitors including Cibacron blue was screened against the active sites of the Na-GST-3 structure (PDB ID: 3W8S). The hit compounds were profiled to ascertain the mechanisms of binding, anthelmintic bioactivity, physicochemical and pharmacokinetic properties. The AutoDock Vina docking protocol was validated by obtaining 0.731 as the area under the curve calculated via the receiver operating characteristics curve. Four compounds comprising ZINC85999636, ZINC35418176, ZINC14825190, and Dammarane Triterpene13 were identified as potential lead compounds with binding energies less than -9.0 kcal/mol. Furthermore, the selected compounds formed key intermolecular interactions with critical residues Tyr95, Gly13 and Ala14. Notably, ZINC85999636, ZINC14825190, and dammarane triterpene13 were predicted as anthelmintics, whilst all the four molecules shared structural similarities with known inhibitors. Molecular modelling showed that the compounds had reasonably good binding free energies. More so, they had high binding affinities when screened against other variants of the Na-GST, namely Na-GST-1 and Na-GST-2. Ligand quality assessment using ligand efficiency dependent lipophilicity, ligand efficiency, ligand efficiency scale and fit quality scale showed the molecules are worthy candidates for further optimization. The inhibitory potentials of the molecules warrant in vitro studies to evaluate their effect on the heme regulation mechanisms.

9.
Obstet Med ; 15(2): 136-140, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35845228

ABSTRACT

Chronic kidney disease (CKD) and end stage kidney disease are prevalent even in women of reproductive age. These are known to reduce fertility and successful pregnancy. There are chances of conception even in advanced CKD, though laden with complications. We present two cases of women who conceived in advanced CKD and were on haemodialysis in a tertiary hospital in Kenya, and review of literature.

10.
Article in English | MEDLINE | ID: mdl-34912942

ABSTRACT

The emergence of drug resistance against the known hookworm drugs namely albendazole and mebendazole and their reduced efficacies necessitate the need for new drugs. Chemically diverse natural products present plausible templates to augment hookworm drug discovery. The present work utilized pharmacoinformatics techniques to predict African natural compounds ZINC95486082, ZINC95486052 and euphohelionon as potential inhibitory molecules of the hookworm Necator americanus ß tubulin gene. A library of 3390 compounds was screened against a homology-modelled structure of ß tubulin. The docking results obtained from AutoDock Vina was validated with an acceptable area under the curve (AUC) of 0.714 computed from the receiver operating characteristic (ROC) curve. The three selected compounds had favourable binding affinities and were predicted to form no interactions with the resistance-associated mutations Phe167, Glu198 and Phe200. The compounds were predicted as anthelmintics using a Bayesian-based technique and were pharmacologically profiled to be druglike. Further molecular dynamics simulations and MM-PBSA calculations showed the compounds as promising anthelmintic drug leads. Novel critical residues comprising Leu246, Asn247 and Asn256 were also predicted for binding. Euphohelionon was selected as a template for the de novo fragment-based design of five compounds labelled A1, A2, A3, A4 and A5; with four of them having SAscore values below 6, denoting easy synthesis. All the five de novo molecules docked firmly in the binding pocket of the ß tubulin with no binding interactions with the three known resistance mutation residues. Binding energies of -8.2, -7.6, -7.3, -7.2 and -6.8 kcal/mol were obtained for A1, A2, A3, A4 and A5, respectively. The identified compounds can serve as treasure troves from which future potent anthelmintics can be designed. The current study strives to assuage the hookworm disease burden, especially making available molecules with the potential to circumvent the chemoresistance.

11.
Biochemistry ; 60(26): 2064-2070, 2021 07 06.
Article in English | MEDLINE | ID: mdl-34137579

ABSTRACT

Here we show that an NH-π interaction between a highly conserved Asn and a nearby Trp stabilizes the WW domain of the human protein Pin1. The strength of this NH-π interaction depends on the structure of the arene, with NH-π interactions involving Trp or naphthylalanine being substantially more stabilizing than those involving Tyr or Phe. Calculations suggest arene size and polarizability are key structural determinants of NH-π interaction strength. Methylation or PEGylation of the Asn side-chain amide nitrogen each strengthens the associated NH-π interaction, though likely for different reasons. We hypothesize that methylation introduces steric clashes that destabilize conformations in which the NH-π interaction is not possible, whereas PEGylation strengthens the NH-π interaction via localized desolvation of the protein surface.


Subject(s)
Asparagine/chemistry , Hydrogen Bonding/drug effects , NIMA-Interacting Peptidylprolyl Isomerase/chemistry , Polyethylene Glycols/chemistry , Tryptophan/chemistry , WW Domains/drug effects , Amino Acid Sequence , Humans , Methylation , Models, Molecular , Mutation , NIMA-Interacting Peptidylprolyl Isomerase/genetics , Protein Conformation , Thermodynamics , WW Domains/genetics
12.
Biomolecules ; 11(5)2021 04 29.
Article in English | MEDLINE | ID: mdl-33946644

ABSTRACT

Severely ill coronavirus disease 2019 (COVID-19) patients show elevated concentrations of pro-inflammatory cytokines, a situation commonly known as a cytokine storm. The p38 MAPK receptor is considered a plausible therapeutic target because of its involvement in the platelet activation processes leading to inflammation. This study aimed to identify potential natural product-derived inhibitory molecules against the p38α MAPK receptor to mitigate the eliciting of pro-inflammatory cytokines using computational techniques. The 3D X-ray structure of the receptor with PDB ID 3ZS5 was energy minimized using GROMACS and used for molecular docking via AutoDock Vina. The molecular docking was validated with an acceptable area under the curve (AUC) of 0.704, which was computed from the receiver operating characteristic (ROC) curve. A compendium of 38,271 natural products originating from Africa and China together with eleven known p38 MAPK inhibitors were screened against the receptor. Four potential lead compounds ZINC1691180, ZINC5519433, ZINC4520996 and ZINC5733756 were identified. The compounds formed strong intermolecular bonds with critical residues Val38, Ala51, Lys53, Thr106, Leu108, Met109 and Phe169. Additionally, they exhibited appreciably low binding energies which were corroborated via molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations. The compounds were also predicted to have plausible pharmacological profiles with insignificant toxicity. The molecules were also predicted to be anti-inflammatory, kinase inhibitors, antiviral, platelet aggregation inhibitors, and immunosuppressive, with probable activity (Pa) greater than probable inactivity (Pi). ZINC5733756 is structurally similar to estradiol with a Tanimoto coefficient value of 0.73, which exhibits anti-inflammatory activity by targeting the activation of Nrf2. Similarly, ZINC1691180 has been reported to elicit anti-inflammatory activity in vitro. The compounds may serve as scaffolds for the design of potential biotherapeutic molecules against the cytokine storm associated with COVID-19.


Subject(s)
COVID-19/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , Biological Products/metabolism , Coronavirus/pathogenicity , Cytokines/metabolism , Humans , Inflammation/metabolism , Molecular Docking Simulation , ROC Curve
13.
Clin Med Res ; 19(2): 64-71, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33789952

ABSTRACT

Objective: Perioperative chemotherapy can potentially downstage esophageal cancer, reducing the risk of early systemic dissemination. One recommended neoadjuvant regimen for managing gastroesophageal junction and esophageal cancer is docetaxel, cisplatin, and 5-fluorouracil (DCF). To address the high toxicity profile of DCF, modifications in dosages and treatment intervals have been studied. We integrated a modified DCF regimen (mDCF) into a multimodal treatment approach for non-metastatic esophageal cancer (nMEC). Retrospectively, we sought to describe our community experience of administrating neoadjuvant mDCF to patients with nMEC.Design: Patients diagnosed with nMEC between August 2008 and November 2017 and prescribed mDCF were identified for retrospective review. Outcomes of interest included disease-free survival (DFS), overall survival (OS), and hematologic toxicities. Analyses were performed using SAS 9.4.Results: Thirty patients met inclusion criteria with a median age of 64.9 years; 90% were male. The 2-year and 5-year DFS was 60.8% and 41.7%, respectively, for adenocarcinoma and 71.4% and 71.4% for squamous cell carcinoma (SCC). The 2-year and 5-year OS was 64.9% and 44.5%, respectively, for adenocarcinoma and 71.4% and 71.4% for SCC. Both DFS and OS decreased with increasing disease stage, histology (adenocarcinoma versus squamous), esophageal compared to esophagogastric-junction involvement, and without surgical intervention. Frequent toxicity grades for leukopenia and thrombocytopenia were Grades I and II.Conclusion: Using an mDCF regimen in combination with chemoradiation +/- surgical resection in a community setting appears to have an acceptable toxicity profile as well as DFS and OS outcomes compared to chemotherapeutic regimens reported in other similar studies.


Subject(s)
Esophageal Neoplasms , Stomach Neoplasms , Aged , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Cisplatin/therapeutic use , Docetaxel/therapeutic use , Esophageal Neoplasms/drug therapy , Fluorouracil/therapeutic use , Humans , Male , Middle Aged , Neoadjuvant Therapy , Retrospective Studies , Stomach Neoplasms/drug therapy , Taxoids/therapeutic use
14.
Biomolecules ; 11(3)2021 03 18.
Article in English | MEDLINE | ID: mdl-33803906

ABSTRACT

The huge burden of leishmaniasis caused by the trypanosomatid protozoan parasite Leishmania is well known. This illness was included in the list of neglected tropical diseases targeted for elimination by the World Health Organization. However, the increasing evidence of resistance to existing antimonial drugs has made the eradication of the disease difficult to achieve, thus warranting the search for new drug targets. We report here studies that used computational methods to identify inhibitors of receptors from natural products. The cell division cycle-2-related kinase 12 (CRK12) receptor is a plausible drug target against Leishmania donovani. This study modelled the 3D molecular structure of the L. donovani CRK12 (LdCRK12) and screened for small molecules with potential inhibitory activity from African flora. An integrated library of 7722 African natural product-derived compounds and known inhibitors were screened against the LdCRK12 using AutoDock Vina after performing energy minimization with GROMACS 2018. Four natural products, namely sesamin (NANPDB1649), methyl ellagic acid (NANPDB1406), stylopine (NANPDB2581), and sennecicannabine (NANPDB6446) were found to be potential LdCRK12 inhibitory molecules. The molecular docking studies revealed two compounds NANPDB1406 and NANPDB2581 with binding affinities of -9.5 and -9.2 kcal/mol, respectively, against LdCRK12 which were higher than those of the known inhibitors and drugs, including GSK3186899, amphotericin B, miltefosine, and paromomycin. All the four compounds were predicted to have inhibitory constant (Ki) values ranging from 0.108 to 0.587 µM. NANPDB2581, NANPDB1649 and NANPDB1406 were also predicted as antileishmanial with Pa and Pi values of 0.415 and 0.043, 0.391 and 0.052, and 0.351 and 0.071, respectively. Molecular dynamics simulations coupled with molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) computations reinforced their good binding mechanisms. Most compounds were observed to bind in the ATP binding pocket of the kinase domain. Lys488 was predicted as a key residue critical for ligand binding in the ATP binding pocket of the LdCRK12. The molecules were pharmacologically profiled as druglike with inconsequential toxicity. The identified molecules have scaffolds that could form the backbone for fragment-based drug design of novel leishmanicides but warrant further studies to evaluate their therapeutic potential.


Subject(s)
Antiprotozoal Agents/pharmacology , Leishmania donovani/cytology , Leishmania donovani/drug effects , Amphotericin B/pharmacology , Binding Sites , Cell Cycle/drug effects , Cyclin-Dependent Kinase 9/metabolism , Humans , Molecular Dynamics Simulation , Morpholines/pharmacology , Paromomycin/pharmacology , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/pharmacology , Protein Structure, Secondary , Pyrazoles/pharmacology , Pyrimidines/pharmacology
15.
Molecules ; 26(2)2021 Jan 14.
Article in English | MEDLINE | ID: mdl-33466743

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome virus 2 (SARS-CoV-2) has impacted negatively on public health and socioeconomic status, globally. Although, there are currently no specific drugs approved, several existing drugs are being repurposed, but their successful outcomes are not guaranteed. Therefore, the search for novel therapeutics remains a priority. We screened for inhibitors of the SARS-CoV-2 main protease and the receptor-binding domain of the spike protein from an integrated library of African natural products, compounds generated from machine learning studies and antiviral drugs using AutoDock Vina. The binding mechanisms between the compounds and the proteins were characterized using LigPlot+ and molecular dynamics simulations techniques. The biological activities of the hit compounds were also predicted using a Bayesian-based approach. Six potential bioactive molecules NANPDB2245, NANPDB2403, fusidic acid, ZINC000095486008, ZINC0000556656943 and ZINC001645993538 were identified, all of which had plausible binding mechanisms with both viral receptors. Molecular dynamics simulations, including molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) computations revealed stable protein-ligand complexes with all the compounds having acceptable free binding energies <-15 kJ/mol with each receptor. NANPDB2245, NANPDB2403 and ZINC000095486008 were predicted as antivirals; ZINC000095486008 as a membrane permeability inhibitor; NANPDB2403 as a cell adhesion inhibitor and RNA-directed RNA polymerase inhibitor; and NANPDB2245 as a membrane integrity antagonist. Therefore, they have the potential to inhibit viral entry and replication. These drug-like molecules were predicted to possess attractive pharmacological profiles with negligible toxicity. Novel critical residues identified for both targets could aid in a better understanding of the binding mechanisms and design of fragment-based de novo inhibitors. The compounds are proposed as worthy of further in vitro assaying and as scaffolds for the development of novel SARS-CoV-2 therapeutic molecules.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Biological Products/pharmacology , Coronavirus 3C Proteases/metabolism , SARS-CoV-2/drug effects , Africa , Antiviral Agents/metabolism , Bayes Theorem , Binding Sites , Biological Products/chemistry , Biological Products/metabolism , Cheminformatics/methods , Coronavirus 3C Proteases/chemistry , Drug Evaluation, Preclinical , Fusidic Acid/chemistry , Fusidic Acid/pharmacology , Ligands , Molecular Docking Simulation , Molecular Dynamics Simulation , Pentacyclic Triterpenes/chemistry , Pentacyclic Triterpenes/pharmacology , Protein Conformation , Betulinic Acid
16.
Rev. peru. med. exp. salud publica ; 37(1): 104-109, ene.-mar. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1101816

ABSTRACT

RESUMEN Se evaluó el uso de partículas magnéticas acopladas a proteína L para la concentración y purificación de anticuerpos monoclonales inmunoglobulina M (mIgM) contra Taenia solium. Se evaluaron tres métodos de concentración y diferentes tiempos de elución y se optimizó la proporción de partículas a la proporción de mIgM. Demostramos que: 1) con el uso partículas magnéticas no se requiere de una concentración previa de mIgM, lo que disminuye la manipulación de los anticuerpos y mejora la recuperación, 2) se puede omitir el uso de un tampón de unión, ya que el pH de la mayoría de los sobrenadantes de cultivo celular son neutros, y 3) se necesitan tiempos de elución más largos (~45 minutos) para aumentar la recuperación a un nivel mayor a 80%. El estudio demuestra que el uso de partículas magnéticas acopladas a proteína L es una herramienta simple y eficiente para la concentración y purificación de mIgM.


ABSTRACT The use of L protein coupled magnetic particles for the concentration and purification of immunoglobulin M (mIgM) monoclonal antibodies against Taenia solium was evaluated. Three concentration methods and different elution times were evaluated and the ratio of particles to the ratio of mIgM was optimized. It is demonstrated that: 1) with the use of magnetic particles, a previous concentration of mIgM is not required, which reduces the manipulation of the antibodies and improves the recovery, 2) the use of a binding buffer can be omitted, since the pH of most cell culture supernatants are neutral, and 3) longer elution times (~ 45 minutes) are needed to increase recovery to a level greater than 80%. The study demonstrates that the use of L protein-coupled magnetic particles is a simple and efficient tool for mIgM concentration and purification.


Subject(s)
Animals , Immunoglobulin M , Taenia solium , Magnetic Phenomena , Antibodies, Monoclonal , Immunoglobulin M/immunology , Taenia solium/immunology , Antibodies, Monoclonal/isolation & purification
18.
J Vasc Access ; 20(6): 697-700, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31057048

ABSTRACT

INTRODUCTION: The objective of our study was to document the level of preparedness for renal replacement therapy assessed by incident hemodialysis vascular access and the access at least 3 months after initiation of hemodialysis at Kenyatta National Hospital, Nairobi. METHODS: Between June and July 2018, we carried out a cross-sectional descriptive study on the preparedness for hemodialysis by patients who were on chronic hemodialysis in the Kenyatta National Hospital Renal Department. Sociodemographic, medical history, duration of follow-up, and state of preparedness parameters were obtained through interview and entered into the questionnaire. The data were entered in preprogrammed format in the Statistical Package for the Social Sciences (SPSS) version 20.0 for analyses. RESULTS: Eighty-two patients were enrolled. Males were 50% (41). The mean age was 45.39 ± 15.96 years but females were 5 years younger than their male counterparts. About 85.4% of the patients were drawn from the hypertension and diabetes clinics, and the mean, mode, and median of the duration of follow-up were 41, 0, and 0 months, respectively, in these clinics. Almost three in every four patients (74.4%) were initiated on hemodialysis as emergency (p value < 0.001). About 80% were initiated hemodialysis via acute catheters placed in the jugular and subclavian veins (p value < 0.001). At least 3 months later, 40% still had acute catheters on the same veins (p value < 0.001). Acute venous catheters in the femoral veins were in 9.2% at initiation and 6.6% of the patients at least 3 months later. Less than 2% of the patients had arteriovenous fistulae at initiation, which rose to 14.5% in 3 months. Tunneled catheters were placed in 11.8% initially and at least 3 months, were almost in 40% of the patients. CONCLUSION: In conclusion, our young hemodialysis population mainly drawn from hypertension and diabetes clinic requires more input in hemodialysis vascular access planning. Focused individualized follow-up and early referrals to nephrologists are required. Uptake of arteriovenous grafts for hemodialysis might reduce the prevalence of hemodialysis catheters. As it is, this population is threatened with iterative vascular accesses complications as well as real danger of exhaustion of their vascular capital. There is real danger of increase in mortality from access complications.


Subject(s)
Arteriovenous Shunt, Surgical/trends , Catheterization, Central Venous/trends , Hospitals/trends , Practice Patterns, Physicians'/trends , Renal Dialysis/trends , Renal Insufficiency, Chronic/therapy , Adult , Cross-Sectional Studies , Female , Humans , Kenya , Male , Middle Aged , Renal Insufficiency, Chronic/diagnosis , Time Factors
20.
Arch Sex Behav ; 47(4): 963-972, 2018 05.
Article in English | MEDLINE | ID: mdl-29071544

ABSTRACT

Voices convey important social information about an individual's identity, including gender. This is especially relevant to transgender individuals, who cite voice alteration as a primary goal of the gender alignment process. Although the voice is a primary target of testosterone therapy among female-to-male (FTM) trans people, little research has explored the effects of such changes on their psychological well-being. Here, we investigated how FTMs' vocal gender related to their well-being. A total of 77 FTMs (M age = 25.45 years, SD = 6.77) provided voice samples and completed measures of their well-being and psychological health. An independent group of 32 naïve raters (M age = 22.16 years, SD = 8.21) subsequently rated the voice samples for masculinity. We found that FTMs whose voices sounded more congruent with their experienced gender (i.e., sounded more masculine) reported greater well-being (better life satisfaction, quality of life, and self-esteem; lower levels of anxiety and depression) than FTMs with less gender congruent (i.e., more feminine) voices (ß = .48). The convergence between outwardly perceived vocal gender and gender identity brought about through hormone replacement therapy may therefore support greater well-being for FTMs.


Subject(s)
Masculinity , Mental Health/trends , Quality of Life/psychology , Transgender Persons/psychology , Transsexualism/psychology , Voice/physiology , Adult , Female , Humans , Male , Young Adult
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