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1.
World J Methodol ; 13(4): 359-365, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37771874

RESUMO

BACKGROUND: The anteromedial meniscofemoral ligament (AMMFL) is a very rare entity, commonly unrecognized and underreported. Although it was not proved to be a cause of anterior knee pain, concerns have been raised on the relationship between the presence of this structure and medial meniscus injury secondary to its abnormal motion. Regarding histologic examination, some studies have shown meniscus-like fibrocartilage, while others have identified it as ligament-like collagenous fibrous connective tissue. CASE SUMMARY: We report the case of a 34-year-old ballerina with an AMMFL associated with a torn medial meniscus of both knees. Surgery was performed to treat the meniscal injury and two biopsies of each AMMFL were taken in different locations to define the histopathological composition. Histologic examination revealed fibrocartilaginous tissue compatible with meniscus. Follow-up evaluation one year after surgery evidenced full remission of symptoms and the patient had resumed her athletic activities. CONCLUSION: Clinical, magnetic resonance imaging, arthroscopic, and histological features have been carefully described to better characterize the AMMFL.

2.
World J Methodol ; 13(5): 502-509, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38229936

RESUMO

BACKGROUND: The ExeterTM Universal cemented femoral component is widely used for total hip replacement surgery. Although there have been few reports of femoral component fracture, removal of a broken femoral stem can be a challenging procedure. CASE SUMMARY: A 54-year-old man with a Dorr A femur sustained a refracture of a primary ExeterTM stem, two years after receiving a revision using a cement-within-cement technique (CWC) through an extended trochanteric osteotomy (ETO). The technical problems related to the CWC technique and the ETO played a major role in the stem fatigue refracture. We performed revision surgery and removed the distal cement using a cortical femoral window technique, followed by re-implantation with an uncemented, modular, distally-fixed uncemented stem. The patient experienced an uneventful postoperative recovery. CONCLUSION: Re-fracture of a modern femoral ExeterTM stem is a rare event, but technical complications related to revision surgery can lead to this outcome. The cortical window osteotomy technique can facilitate the removal of a broken stem and cement, allowing for prosthetic re-implantation under direct vision and avoiding ETO-related complications.

3.
Front Chem ; 9: 690707, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34616711

RESUMO

Among healthy vegetables, those of the genus Allium stand out. Antioxidant and anti-inflammatory properties have been associated with these vegetables, attributed mainly to organosulfur compounds (OSCs). In turn, they are linked to a protective effect counteracting cardiovascular disease development. Now, to really ensure the bioactive efficacy of the said compounds once consumed, it is necessary to previously evaluate the ADME (absorption, distribution, metabolism, and excretion) profile. Alternatively, in vitro and in silico methods attempt to avoid or reduce experimental animals' use and provide preliminary information on drugs' ability to overcome the various biological barriers inherent in the ADME process. In this sense, in silico methods serve to provide primary information on drugs' bioavailability mechanisms. High-performance liquid chromatography (HPLC) using a stationary phase composed of phospholipids, the so-called immobilized artificial membrane (IAM), has been widely recognized as a valuable alternative method to extract and quantify information about the structure and physicochemical properties of organic compounds which are extensively used in studies of quantitative structure-activity relationships (QSARs). In the present study, the chromatographic capacity factors (log k' (IAM)) for 28 OSCs were determined by IAM-HPLC. In order to evaluate the ability of the IAM phase in assessing lipophilicity of the compounds under study, several quantitative structure-retention relationships (QSRRs) were derived from exploring fundamental intermolecular interactions that govern the retention of compounds under study on IAM phases. As expected, the hydrophobic factors are of prime importance for the IAM retention of these compounds. However, the molecular flexibility and specific polar interactions expressed by several electronic descriptors (relative negative charge, RNCG, and Mulliken electronegativity) are also involved. We also evaluated the IAM phase ability to assess several ADME parameters for the OSCs under study obtained using the SwissADME web tool integrated into the SwissDrugDesign workspace and the PreADMET web tool. The human gastrointestinal absorption (HIA), blood-brain barrier (BBB) permeation, and skin permeability were investigated through QSAR modeling, using several chemometric approaches. The ADME properties under study are strongly dependent on hydrophobic factors as expressed by log k'(IAM), which provide evidence for the great potential of the IAM phases in the development of QSAR models.

4.
ADMET DMPK ; 7(3): 196-209, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-35350661

RESUMO

CYP2A6 is a human enzyme responsible for the metabolic elimination of nicotine, and it is also involved in the activation of procarcinogenic nitrosamines, especially those present in tobacco smoke. Several investigations have reported that reducing this enzyme activity may contribute to anti-smoking therapy as well as reducing the risk of promutagens in the body. For these reasons, several authors investigate selective inhibitors molecules toward this enzyme. The aim of this study was to evaluate the interactions between a set of organosulfur compounds and the CYP2A6 enzyme by a quantitative structure-activity relationship (QSAR) analysis. The present work provides a better understanding of the mechanisms involved, with the final goal of providing information for the future design of CYP2A6 inhibitors based on dietary compounds. The reported activity data were modeled by means of multiple regression analysis (MLR) and partial least-squares (PLS) techniques. The results indicate that hydrophobic and steric factors govern the union, while electronic factors are strongly involved in the case of monosulfides.

5.
Food Chem ; 157: 199-204, 2014 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-24679771

RESUMO

This work proposes the novel application of a microextraction technique, solid phase microextraction (SPME), coupled to liquid chromatography with UV detection (HPLC-UV) for the analysis of organosulfur compounds (OSCs) in garlic samples. Additionally, a comparative study of OSCs profiles obtained by SPME coupled to HPLC-UV and gas chromatography with flame photometric detector (GC-FPD), respectively; was carried out. This study provided complementary evidence about OSCs's lability and "artifacts" formation during the analytical process. Raw, cooked and distilled garlic samples were considered. The target analytes were diallyl disulphide (DADS), diallyl sulphide (DAS), diallyl trisulphide (DATS), allicin, 3-vinyl-4H-1,3-dithiin (3-VD), 2-vinyl-4H-1,2-dithiin (2-VD) and (E)- and (Z)-ajoene, which are the most important OSCs with biological activities present in raw and processed garlic. The coupling of SPME and HPLC showed to be reliable, fast, sensible and selective methodology for OSCs analysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Microextração em Fase Sólida/métodos , Cromatografia Líquida , Alho/química
6.
J Agric Food Chem ; 55(8): 3096-103, 2007 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-17367159

RESUMO

In this study, multiple linear regression (MLR) and partial least-squares (PLS) techniques were used for modeling the soybean 15-lipoxygenase inhibitory activity of a varied group of mono-, di-, and trisulfides derived from the essential oil of garlic. The structures of the compounds under study were characterized by means of calculated physicochemical parameters and several nonempirical descriptors, such as topological, geometrical, and quantum chemical indices. The results obtained indicate that the inhibitory activity is strongly dependent on the ability of the compounds to participate in dispersive interactions with the enzyme, as expressed by the solvent-accessible surface area (SASA) and the average distance/distance degree descriptor (ADDD) index. On the other hand, the high contribution of the lowest unoccupied molecular orbit term (LUMO) in the PLS models derived for the di- and trisulfides suggests that the solute's electron-acceptor capacity plays a fundamental role in the inhibitory activity exhibited for these compounds. Finally, the geometric features as expressed by the shape parameters included in the models indicate a low but not negligible positive contribution of molecular linearity in the enzyme-inhibitor binding. In summary, the developed quantitative structure-activity relationship approach successfully accounts for the potencies of organosulfur compounds acting on soybean 15-lipoxygenase and thereby offers both a guide for the synthesis of new compounds and a hypothesis for the molecular basis of their activity.


Assuntos
Compostos Alílicos/química , Glycine max/enzimologia , Inibidores de Lipoxigenase , Inibidores de Lipoxigenase/farmacologia , Relação Quantitativa Estrutura-Atividade , Sulfetos/química , Compostos de Enxofre/farmacologia , Inibidores de Lipoxigenase/química , Óleos Voláteis/química , Análise de Regressão , Compostos de Enxofre/química
7.
Biometals ; 18(3): 213-20, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15984566

RESUMO

The present study was undertaken to assess whether chronic exposition to cadmium (Cd, 0.133 mM per liter for 2 months) through drinking water may affect the lipid contents in the pituitary anterior lobe (PAL) of adult male Wistar rats. As compared to metal non-exposed controls, PALs exposed to cadmium showed an increase in total phospholipid contents, which was associated to an increase of the incorporation of [1-14C]-methyl choline into phosphatidylcholine and of [U-14C]-glucose into total phospholipids. The incorporation of [1-14C]-methyl choline into sphingomyelin was not changed. Incorporation of [1-14C]-acetate into total fatty acids also increased but incorporation of [1-14C]-acetate into cholesterol did not change. The activity of phospholipase D decreased both in PALs from Cd exposed rats and in PAL dispersed cells treated with Cd in the culture medium from Cd non-exposed rats. In PALS from Cd exposed rats, a decrease of serum prolactin and growth hormone concentrations was determined. The results shown that cadmium modifies the lipid contents of pituitary gland and directly or indirectly the levels of prolactin and growth hormone in serum.


Assuntos
Cádmio/farmacologia , Hormônio do Crescimento/sangue , Metabolismo dos Lipídeos , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Prolactina/sangue , Acetatos/farmacologia , Animais , Peso Corporal/efeitos dos fármacos , Colina/química , Colina/farmacologia , Glucose/farmacologia , Masculino , Metilação , Tamanho do Órgão/efeitos dos fármacos , Fosfolipase D/metabolismo , Ratos , Ratos Wistar
8.
Talanta ; 62(2): 247-54, 2004 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-18969288

RESUMO

The electrochemical oxidation of salicylic acid (SA) has been studied on a glassy carbon electrode using cyclic voltammetry and differential pulse voltammetric (DPV) method. SA gives a single irreversible oxidation wave over the wide pH range studied. The irreversibility of the electrode process was verified by different criteria. The mechanism of oxidation is discussed. Using differential pulse voltammetry, SA yielded a well-defined voltammetric response in Britton-Robinson buffer solution, pH 2.37 at 1.088V (versus Ag/AgCl). The method was linear over the SA concentration range: 1-60mugml(-1). The method was successfully applied for the analysis of SA as a hydrolysis product, in solid pharmaceutical formulations containing acetylsalicylic acid (ASA).

9.
J Chem Inf Comput Sci ; 43(6): 2129-36, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14632465

RESUMO

The chromatographic capacity factors (log k') for 32 structurally diverse drugs were determined by high performance liquid chromatography (HPLC) on a stationary phase composed of phospholipids, the so-called immobilized artificial membrane (IAM). In addition, quantitative structure-retention relationships (QSRR) were developed in order to explain the dependence of retention on the chemical structure of the neutral, acidic, and basic drugs considered in this study. The obtained retention data were modeled by means of multiple regression analysis (MLR) and partial least squares (PLS) techniques. The structures of the compounds under study were characterized by means of calculated physicochemical properties and several nonempirical descriptors. For the carboxylic compounds included in the analysis, the obtained results suggest that the IAM-retention is governed by hydrophobicity factors followed by electronic effects due to polarizability in second place. Further, from the analysis of the results obtained of two developed quantitative structure-permeability studies for 20 miscellaneous carboxylic compounds, it may be concluded that the balance between polarizability and hydrophobic effects is not the same toward IAM phases and biological membranes. These results suggest that the IAM phases could not be a suitable model in assessing the acid-membrane interactions. However, it is not possible to generalize this observation, and further work in this area needs to be done to obtain a full understanding of the partitioning of carboxylic compounds in biological membranes. For the non-carboxylic compounds included in the analysis, this work shows that the hydrophobic factors are of prime importance for the IAM-retention of these compounds, while the specific polar interactions, such as electron pair donor-acceptor interactions and electrostatic interactions, are also involved, but they are not dominant.


Assuntos
Cromatografia , Membranas Artificiais , Preparações Farmacêuticas/química , Algoritmos , Aminas Biogênicas/química , Ácidos Carboxílicos/química , Ácidos Carboxílicos/farmacologia , Fenômenos Químicos , Físico-Química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Modelos Químicos , Relação Quantitativa Estrutura-Atividade , Análise de Regressão , Terminologia como Assunto
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