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1.
Medicina (Kaunas) ; 57(12)2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34946273

RESUMO

Human toxocariasis is a helminthozoonosis caused by the migration of Toxocara species larvae through an organism. The infection in humans is transmitted either by direct ingestion of the eggs of the parasite, or by consuming undercooked meat infested with Toxocara larvae. This parasitosis can be found worldwide, but there are significant differences in seroprevalence in different areas, depending mainly on hot climate conditions and on low social status. However, the literature estimates of seroprevalence are inconsistent. Infected patients commonly present a range of symptoms, e.g., abdominal pain, decreased appetite, restlessness, fever, and coughing. This manuscript presents a case report of a polytraumatic patient who underwent a two-phase spinal procedure for a thoracolumbar fracture. After the second procedure, which was a vertebral body replacement via thoracotomy, the patient developed a pathologic pleural effusion. A microscopic cytology examination of this effusion revealed the presence of Toxocara species larvae. Although the patient presented no specific clinical symptoms, and the serological exams (Enzyme-linked immunosorbent assay (ELISA), Western blot) were negative, the microscopic evaluation enabled a timely diagnosis. The patient was successfully treated with albendazole, with no permanent sequelae of the infection.


Assuntos
Parasitos , Toxocaríase , Animais , Ensaio de Imunoadsorção Enzimática , Humanos , Estudos Soroepidemiológicos , Status Social , Toxocara , Toxocaríase/diagnóstico , Toxocaríase/tratamento farmacológico
2.
Int J Cancer ; 139(10): 2252-60, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27407063

RESUMO

Richter syndrome represents the transformation of the chronic lymphocytic leukemia (CLL) into an aggressive lymphoma, most frequently the diffuse large B-cell lymphoma (DLBCL). In this report we describe a patient with CLL, who developed a clonally-related pleomorphic highly-aggressive mantle cell lymphoma (MCL) after five cycles of a fludarabine-based second-line therapy for the first relapse of CLL. Molecular cytogenetic methods together with whole-exome sequencing revealed numerous gene alterations restricted to the MCL clone (apart from the canonical t(11;14)(q13;q32) translocation) including gain of one copy of ATM gene or emergence of TP53, CREBBP, NUP214, FUBP1 and SF3B1 gene mutations. Similarly, gene expression analysis revealed vast differences between the MCL and CLL transcriptome, including overexpression of cyclin D1, downregulation of cyclins D2 and D3, or downregulation of IL4R in the MCL clone. Backtracking analysis using quantitative PCR specifically detecting an MCL-restricted focal deletion of TP53 revealed that the pre-MCL clone appeared in the bone marrow and peripheral blood of the patient approximately 4 years before the clinical manifestation of MCL. Both molecular cytogenetic and sequencing data support the hypothesis of a slow development of the pre-MCL clone in parallel to CLL over several years, and thereby exclude the possibility that the transformation event occurred at the stage of the CLL relapse clone by mere t(11;14)(q13;q32) acquisition.


Assuntos
Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Cromossomos Humanos Par 11 , Cromossomos Humanos Par 14 , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Leucemia Linfocítica Crônica de Células B/metabolismo , Perda de Heterozigosidade , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Linfoma de Célula do Manto/metabolismo , Pessoa de Meia-Idade , Translocação Genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
3.
J Sep Sci ; 38(2): 171-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25378270

RESUMO

The present study was aimed to investigate the polyphenolic profile of a pepper (Capsicum annuum L.) extract from Algeria and evaluate its biological activity. The total polyphenol content of the extract was determined as 1.373 mg of gallic acid equivalents (±0.0046), whereas the flavonoids were determined as 0.098 mg of quercetin (±0.0015). The determination of the complete polyphenolic profile of the extract was achieved by liquid chromatography with an RP-amide column in combination with photodiode array and mass spectrometry detection through an electrospray ionization interface. A total of 18 compounds were identified, of which five were reported for the first time in the sample tested. Quercetin rhamnoside was the most abundant compound (82.6 µg/g of fresh pepper) followed by quercetin glucoside (19.86 µg/g). The antioxidant activity and antimicrobial effects were also determined. For the antimicrobial tests assessed against Gram-positive and Gram-negative bacteria, kaempferol showed the strongest inhibitory effect followed by quercetin and caffeic acids. In the study of the cytotoxicity of the extract, the cancer cells (U937) were more affected than the normal cells (peripheral blood mononucleated cells), with more than 62% inhibition at the highest concentration.


Assuntos
Capsicum/química , Cromatografia Líquida de Alta Pressão/métodos , Extratos Vegetais/química , Polifenóis/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Células U937
4.
Chromatographia ; 78: 21-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25568463

RESUMO

Elution and solvation processes in liquid chromatography may be controlled by temperature changes. In the case of solvent adsorption, the temperature influences the amount of adsorbed solvent as well as the enthalpy and entropy of the solvation process. In this work, the thermodynamic parameters of organic solvents used as organic modifiers in the reversed-phase high-performance liquid chromatography elution process were determined. The changes of enthalpy and entropy in a series of chemically bonded stationary phases were measured to determine the effects of the temperature and surface coverage density of octadecyl ligands on the thermodynamic parameters of the solvation. For both the enthalpy and entropy a parabolic trend was observed with the minimum for medium surface coverage. The correlation of solvent adsorption values with the enthalpy of solvation was also investigated. The highest influence of the temperature on solvation process was observed for stationary phases with high surface coverage.

5.
J Sep Sci ; 37(4): 345-51, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24339351

RESUMO

The chromatographic behavior of steroid hormones on four cholesterol-bonded stationary phases with different structures in binary methanol/water mobile phases was studied. Of the stationary phases tested, the commercially available stationary phases Cogent UDC cholesterol™ and COSMOSIL cholester™ provided better separations of steroid hormones in comparison to homemade aminocholesterol and diaminocholesterol stationary phases. The results show that the temperature has a significant influence on the retention and selectivity for steroid hormones separation. The temperature increase may cause changes in the elution order. From the dependences of the retention (ln k) on temperature (1/T), the standard partial molar enthalpy and standard partial molar entropy were calculated and their enthalpic and entropic contributions to the retention were compared. The enthalpic effects principally control the retention mechanism.


Assuntos
Colesterol/química , Hormônios Esteroides Gonadais/isolamento & purificação , Metanol/química , Termodinâmica , Água/química
6.
Cesk Patol ; 50(3): 118-26, 2014 Jul.
Artigo em Tcheco | MEDLINE | ID: mdl-25186592

RESUMO

Complex laboratory investigation is necessary for the diagnosis and relevant classification of lymphomas. The classical histopathological morphology and cytology investigation is essential, but further investigations such as immunohistochemistry and fluorescence in situ hybridization are necessary. It is also important to employ flow cytometry as a method of investigation running synchronously or preceding the histopathological approach. Last but not least, the investigation of nucleic acids in lymphoma by molecular approaches is necessary and has become an everyday practice. Communication between pathologists and clinical colleagues (oncologists, hematologists, internal medicine specialists and radiologists) is very important. We demonstrate the necessity of a complex diagnostic approach to lymphomas and an appropriate interpretation of all laboratory investigations giving examples of eight patients with various types of lymphomas. In some cases, it is impossible to properly diagnose a lymphoma without molecular investigation. Occasionally, the results of the molecular investigation may be misleading and/or may be inaccurately interpreted, leading to an incorrect conclusion. For that reason, it is very important to incorporate all specialized laboratories and their teams under one roof (preferably that of pathology departments), enabling tight and daily cooperation between the specialists. This is the way to reach a precise diagnosis in a majority of cases, as well as how to comply with clinical expectations of properly classified lymphomas for a targeted therapy of patients.


Assuntos
Linfoma/diagnóstico , Patologia Clínica/métodos , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Masculino , Encaminhamento e Consulta
7.
J Clin Med ; 13(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38592338

RESUMO

Background: Percutaneous vertebroplasty (PVP) and kyphoplasty (PKP) are established methods in the treatment of vertebral compression fractures (VCFs). In our manuscript, the target was to evaluate the efficacy of PVPs/PKPs and to determine the implications of potential periprocedural complications. Methods: 280 patients, specifically 194 women (69.3%) and 86 men (30.7%), were enrolled. We used the AO spine fractures classification and the Yeom classification to determine the subtype of cement leakage. Only single-level VCFs of the thoracic or lumbar spine were included. Visual analogue scale (VAS) was assessed preoperatively and regularly after the surgery. Vertebral compression ratio (VBCR) was used to determine postoperative vertebral body collapse. Results: We recorded 54 cases (19.3%) of cement leakage. There was a significant decrease in mean VAS scores (6.82-0.76 in PVPs, 7.15-0.81 in PKPs). The decrease in VBCR was greater in the VP group (4.39%; 84.21-79.82) compared to the KP group (1.95%; 74.36-72.41). Conclusions: No significant difference in the risk of cement leakage when comparing KPs and VPs was found. VPs and KPs provide rapid and significant pain relief in patients with VCFs. Clinically relevant complications of VPs and KPs are rare. Kyphoplasties prevent further vertebral body collapse more effectively compared to vertebroplasties.

8.
J Sep Sci ; 36(17): 2753-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23801486

RESUMO

We investigated the retention behavior of phenolic acids in nonaqueous normal-phase (NP) LC with buffered methanol/acetonitrile mobile phases on hydrosilated silica-based stationary phases. The silica hydride, Diamond hydride, Bidentate C18, and Cholesterol columns showed a higher retention of phenolic acids in the nonaqueous mobile phases than in aqueous NP mobile phases. There are some selectivity differences between the aqueous and nonaqueous mobile phases, but generally the resolution and selectivity are better in the aqueous systems. The retention of the phenolic acids tested decreased with increasing concentration of methanol in the mobile phase, up to 20% v/v methanol. At increased temperatures, the retention factors and peak widths decrease in both NP modes, showing linear ln k versus 1/T plots, due to a single retention mechanism over the temperature range from 25°C up to the column stability limit, however, the best separations are achieved at low temperatures. The enthalpic and entropic contributions to the retention were determined, and the differences between the aqueous and nonaqueous modes are possibly due to the adsorbed water layer.

9.
J Clin Med ; 11(19)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36233673

RESUMO

Osteoid osteoma is a benign bone tumor typically affecting the long bones of the lower limbs in young male patients. The lesion can be asymptomatic but, in most cases, patients present with characteristic nocturnal pain that is very responsive to the administration of non-steroidal anti-inflammatory drugs. Although osteoid osteomas can regress spontaneously over time, surgical therapy is often indicated in cases of long-lasting resistant pain. Apart from a traditional open resection, the modalities of minimally invasive surgery, such as radiofrequency ablation or cryoablation, have gradually become the option of choice in most cases. The first part of this manuscript is a minireview of the contemporary literature on the pathogenesis, diagnosis, and current trends in the treatment of osteoid osteoma. The second part is a case report of our own experience with a conventional C-arm-guided radiofrequency ablation of an osteoid osteoma located in the femoral neck in an adolescent patient. The aim was to prove that, even when more sophisticated guiding devices (CT, O-arm, etc.) are not available, the safe and reliable ablation of the lesion using a C-arm is still possible even in hard-to-reach areas. The case was a success, with no perioperative or postoperative complications.

10.
Arthroplast Today ; 13: 29-34, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34917718

RESUMO

We present a case report of a 60-year-old Caucasian female patient, who had undergone a series of procedures for a periprosthetic (after total hip arthroplasty) Vancouver C type diaphyseal fracture of the right femur (reverse distal femoral locking compression plate [LCP] osteosynthesis, then a corrective osteotomy with another distal femoral LCP osteosynthesis). Subsequently, she developed high-grade osteoarthrosis of the right knee, indicated for a total knee arthroplasty. Considering the extent of previous procedures, which had significantly compromised the bone quality of the femur and therefore increased the risk of a refracture after an eventual hardware removal, we decided to retain the LCP plate. We concluded that the optimal solution would be the use of a computer-navigated total knee arthroplasty. This procedure obviated the need for intramedullary guiding, while ensuring optimal joint alignment. No postoperative complications emerged.

11.
Arthroplast Today ; 10: 171-174, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34409140

RESUMO

Traumatic anterior dislocation of a total knee arthroplasty (TKA) is an extremely rare occurrence. There are only a few known cases of this type of dislocation which discuss the high risk of a neurovascular complication. This article describes a traumatic anterior dislocation of the TKA with a severe vascular lesion in a 75-year-old severely comorbid patient. Further complications led to the development of a compartment syndrome. Despite the repeated effort in performing a well-functioning anastomosis of the popliteal artery tear by the vascular surgeon, reperfusion of the lower extremity was not effective. Furthermore, multiorgan system failure due to the reperfusion syndrome evolved. This led to an above-knee amputation as a lifesaving procedure. Despite thorough intensive care therapy, the patient did not survive this complication. Presently there are no reported cases with such severe complications after the luxation of a previously well-functioning TKA leading to the death of the patient.

12.
J Sep Sci ; 33(6-7): 841-52, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20087874

RESUMO

We investigated the retention of phenolic acid and flavone antioxidants on five polar columns in buffered aqueous ACN mobile phases. All columns show mixed retention mechanism: RP in highly aqueous mobile phases and normal phase (hydrophilic interaction LC, HILIC) in mobile phases with high concentration of ACN. The Silica Hydride and the ZIC HILIC sulfobetaine zwitterionic columns show rather limited retention in the RP mode. The Luna HILIC column shows higher retention in both the HILIC and the RP modes in comparison to the PEG and DIOL columns. We characterized the selectivity of various HILIC systems using linear solvation energy relationship model with molecular structure descriptors characterizing selective molecular size, dipole-dipole and proton-donor/proton-acceptor interactions and we investigated the effects of the mobile phase composition on the linear solvation energy relationship characteristics of the separation phase systems to select suitable conditions for orthogonal HILIC separations in combination with RP systems. Dual retention mechanism offers possibilities for using complementary selectivity in the HILIC and the RP modes for sequential 2-D separations of natural antioxidants on a single Luna HILIC column. Column equilibration time of 15 min between alternating RP and HILIC gradient runs is sufficient for reproducible results.

13.
Cesk Patol ; 50(1): 33, 38-9, 2014 Jan.
Artigo em Tcheco | MEDLINE | ID: mdl-25562099
14.
Clin Cancer Res ; 25(14): 4455-4465, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004002

RESUMO

PURPOSE: Mantle cell lymphoma (MCL) is an aggressive subtype of B-cell non-Hodgkin lymphomas characterized by (over)expression of BCL2. A BCL2-targeting drug, venetoclax, has promising anticancer activity in MCL. We analyzed molecular mechanisms of venetoclax resistance in MCL cells and tested strategies to overcome it. EXPERIMENTAL DESIGN: We confirmed key roles of proapoptotic proteins BIM and NOXA in mediating venetoclax-induced cell death in MCL. Both BIM and NOXA are, however, differentially expressed in cell lines compared with primary cells. First, NOXA protein is significantly overexpressed in most MCL cell lines. Second, deletions of BIM gene harbored by three commonly used MCL cell lines (JEKO-1, MINO, and Z138) were not found by array comparative genomic hybridization using a validation set of 24 primary MCL samples. RESULTS: We demonstrated that MCL1 and NOXA play important roles in mediating resistance to venetoclax. Consequently, we tested an experimental treatment strategy based on cotargeting BCL2 with venetoclax and MCL1 with a highly specific small-molecule MCL1 inhibitor S63845. The combination of venetoclax and S63845 demonstrated synthetic lethality in vivo on a panel of five patient-derived xenografts established from patients with relapsed MCL with adverse cytogenetics. CONCLUSIONS: Our data strongly support investigation of venetoclax in combination with S63845 as an innovative treatment strategy for chemoresistant MCL patients with adverse cytogenetics in the clinical grounds.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Sinergismo Farmacológico , Linfoma de Célula do Manto/tratamento farmacológico , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Recidiva Local de Neoplasia/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Pirimidinas/farmacologia , Sulfonamidas/farmacologia , Tiofenos/farmacologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Linfoma de Célula do Manto/metabolismo , Linfoma de Célula do Manto/patologia , Camundongos , Camundongos Endogâmicos NOD , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , Recidiva Local de Neoplasia/metabolismo , Recidiva Local de Neoplasia/patologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Clin Cancer Res ; 22(5): 1138-49, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26467384

RESUMO

PURPOSE: To investigate the roles of BCL2, MCL1, and BCL-XL in the survival of diffuse large B-cell lymphoma (DLBCL). EXPERIMENTAL DESIGNS: Immunohistochemical analysis of 105 primary DLBCL samples, and Western blot analysis of 18 DLBCL cell lines for the expression of BCL2, MCL1, and BCL-XL. Pharmacologic targeting of BCL2, MCL1, and BCL-XL with ABT-199, homoharringtonine (HHT), and ABT-737. Analysis of DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL. Immunoprecipitation of MCL1 complexes in selected DLBCL cell lines. Experimental therapy aimed at inhibition of BCL2 and MCL1 using ABT-199 and HHT, single agent, or in combination, in vitro and in vivo on primary cell-based murine xenograft models of DLBCL. RESULTS: By the pharmacologic targeting of BCL2, MCL1, and BCL-XL, we demonstrated that DLBCL can be divided into BCL2-dependent and MCL1-dependent subgroups with a less pronounced role left for BCL-XL. Derived DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL, as well as the immunoprecipitation experiments, which analyzed MCL1 protein complexes, confirmed these findings at the molecular level. We demonstrated that concurrent inhibition of BCL2 and MCL1 with ABT-199 and HHT induced significant synthetic lethality in most BCL2-expressing DLBCL cell lines. The marked cytotoxic synergy between ABT-199 and HHT was also confirmed in vivo using primary cell-based murine xenograft models of DLBCL. CONCLUSIONS: As homoharringtonine is a clinically approved antileukemia drug, and ABT-199 is in advanced phases of diverse clinical trials, our data might have direct implications for novel concepts of early clinical trials in patients with aggressive DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Proteína bcl-X/biossíntese , Animais , Apoptose/efeitos dos fármacos , Compostos de Bifenilo/administração & dosagem , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Harringtoninas/administração & dosagem , Mepesuccinato de Omacetaxina , Humanos , Linfoma Difuso de Grandes Células B/classificação , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/patologia , Camundongos , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Nitrofenóis/administração & dosagem , Piperazinas/administração & dosagem , Proteínas Proto-Oncogênicas c-bcl-2/genética , Sulfonamidas/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Virchows Arch ; 442(6): 538-47, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12728315

RESUMO

INTRODUCTION: Mantle cell lymphoma (MCL) is a clinicopathological entity characterized by an aggressive clinical course, morphological features, and overexpression of cyclin D1 due to juxtaposition of the bcl-1 locus (and CCND1 gene coding for the cyclin D1) to the IgH gene. This phenomenon is caused by t(11;14)(q13;q32). The morphological diagnosis of MCL may pose difficulties. Ancillary methods are available to support the diagnosis. PATIENTS AND METHODS: We studied a group of 32 patients with MCL; 24 men and 8 women. The median age at the diagnosis was 64 years. We characterized the investigated group by histology, and to analyze the immunohistochemical (IHC) profile we used a panel of antibodies including anti-cyclin D1. Polymerase chain reaction (PCR) was used to detect the rearrangement of bcl-1/IgH in 26 cases (in 11 patients, the DNA was isolated from frozen tissues or from nucleated cells of bone-marrow aspirate or peripheral blood, in 15 patients we utilized paraffin-embedded material). Dual color fluorescence in situ hybridization (FISH) on interphase nuclei detecting the t(11;14)(q13;q32) was applied in all 32 cases. RESULTS: Cyclin D1 IHC was positive in 29 of 30 cases tested (97%). In six, the result was weak and difficult to rely on to support the diagnosis. PCR revealed the fusion gene in 14 of the 26 cases (54%). The best yield was obtained from fresh and frozen samples (8 of 11 positive). Using FISH, we identified the translocation in all 32 patients, the findings being easily interpretable in 29 patients. In three cases, the intensity of red and green signals was weaker and difficult to read though the co-hybridized signals were identified. The classical pattern of the translocation was observed in 26 patients, while in 3 we found variant patterns suggesting a loss of the V segment of the IgH gene (2x) and a shift in the breakpoint region at chromosome 11 (1x). CONCLUSION: The diagnosis of MCL should be supported by a complex laboratory approach. Interphase FISH seems a useful complementary method to morphology and IHC. It is applicable to various tissues and cells prepared as tissue imprints or histological sections.


Assuntos
Cromossomos Humanos Par 11 , Cromossomos Humanos Par 14 , Linfoma de Célula do Manto/diagnóstico , Translocação Genética , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Ciclina D1/análise , DNA de Neoplasias/análise , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Hibridização in Situ Fluorescente , Linfoma de Célula do Manto/química , Linfoma de Célula do Manto/genética , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Estudos Retrospectivos
17.
Neuro Endocrinol Lett ; 21(5): 417-420, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11452235

RESUMO

OBJECTIVES: The authors described a case of Riedel's thyroiditis, a relatively rare disease affecting the thyroid gland. RESULTS: A 38-year-old female was diagnosed with Riedel's thyroiditis by a frozen section examination during attempted surgery for the suspicion of malignancy. The histopathologic examination confirmed the diagnosis of Riedel's thyroiditis combined with signs of giant cell arteritis. After hemithyroidectomy, the patient had paresis of the recurrent laryngeal nerve for five days and signs of hypothyroidism and hypoparathyroidism for three months after surgery. The level of thyroid peroxidase antibodies titer was higher. The patient had no compression symptoms, no signs of systemic immunopathology, and no signs of extracervical fibrosis. She was put on prednison 5 mg daily. CONCLUSIONS: Riedel's thyroiditis can be looked upon as a cervical fibrosis of unknown etiology affecting the thyroid. In our case it was combined with signs of giant cell arteritis.

18.
J Chromatogr A ; 1374: 102-111, 2014 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-25544246

RESUMO

Excess adsorption of water from aqueous acetonitrile mobile phases was investigated on 16 stationary phases using the frontal analysis method and coulometric Karl-Fischer titration. The stationary phases include silica gel and silica-bonded phases with different polarities, octadecyl and cholesterol, phenyl, nitrile, pentafluorophenylpropyl, diol and zwitterionic sulfobetaine and phosphorylcholine ligands bonded on silica, hybrid organic-silica and hydrosilated matrices. Both fully porous and core-shell column types were included. Preferential uptake of water by the columns can be described by Langmuir isotherms. Even though a diffuse rather than a compact adsorbed discrete layer of water on the adsorbent surface can be formed because of the unlimited miscibility of water with acetonitrile, for convenience, the preferentially adsorbed water was expressed in terms of a hypothetical monomolecular water layer equivalent in the inner pores. The uptake of water strongly depends on the polarity and type of the column. Less than one monomolecular water layer equivalent was adsorbed on moderate polar silica hydride-based stationary phases, Ascentis Express F5 and Ascentis Express CN column at the saturation capacity, while on more polar stationary phases, several water layer equivalents were up-taken from the mobile phase. The strongest affinity to water was observed on the ZIC cHILIC stationary phases, where more than nine water layer equivalents were adsorbed onto its surface at its saturation capacity. Columns with bonded hydroxyl and diol ligands show stronger water adsorption in comparison to bare silica. Columns based on hydrosilated silica generally show significantly decreased water uptake in comparison to stationary phases bonded on ordinary silica. Significant correlations were found between the water uptake and the separation selectivity for compounds with strong polarity differences.


Assuntos
Acetonitrilas/química , Cromatografia Líquida/instrumentação , Água/química , Adsorção , Cromatografia Líquida/métodos , Sílica Gel , Silicatos/química , Dióxido de Silício/química
19.
J Chromatogr A ; 1286: 111-8, 2013 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-23497850

RESUMO

The possibility of applying a theoretical model in the prediction of the retention of phenolic acids on hydrosilated silica, in aqueous normal phase mode was studied. The actual gradient of the aqueous component in acetonitrile may fluctuate from the pre-set program, as even the gradient-grade acetonitrile contains some water. Hence, the actual concentration of water during the gradient run is higher than pre-set by the gradient program, which leads to lower than expected sample retention. Furthermore, the actual gradient profile may be affected by an increase in water uptake on a polar column during the gradient run. These effects were investigated using the using frontal analysis method and Karl-Fischer titration, for the determination of water in the initial mobile phase, and in the column effluent. Preferential adsorption of water on the Silica hydride, Diamond hydride, UDC Cholesterol, Bidentate C18, and Phenyl hydride columns can be described by Langmuir isotherms. At the column saturation capacity, less than one monomolecular water layer is adsorbed, with a further decrease in coverage density for modified materials. Parameters of semi-logarithmic and logarithmic model equations, describing the dependence of retention factor on the concentration of water, were determined under isocratic conditions. These parameters and linear gradient profiles corrected for the actual water concentrations were used in calculation of gradient retention data. The corrections for the actual water concentration greatly improved the agreement between the experiment and the predicted gradient elution volumes. Generally, the semi-logarithmic model provides slightly better prediction of the gradient data, with respect to the logarithmic retention model.


Assuntos
Cromatografia Líquida/instrumentação , Cromatografia Líquida/métodos , Dióxido de Silício/química , Adsorção , Hidroxibenzoatos/química , Água/química
20.
J Chromatogr A ; 1228: 125-34, 2012 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-21782183

RESUMO

The effects of mobile phase composition and of temperature on the retention behavior of phenolic acids were studied on 4 hydrosilated (type C silica) based columns in buffered aqueous acetonitrile, both in the aqueous normal phase (HILIC) and in the reversed-phase mobile phase range. The UDC cholesterol and the C18 bidentate columns show significant reversed phase and normal-phase retention mechanisms, whereas very weak retention in the reversed-phase mode was observed on the silica hydride and the Diamond hydride columns. The concentration effects of the aqueous acetate buffer over the full mobile phase (HILIC and RP) composition range can be described by a simple four-parameter equation. At increasing temperature, the retention times and peak widths decrease both in the aqueous normal phase and in the reversed phase mobile phase range. Linear van't Hoff log k versus 1/T plots were observed, indicating a single retention mechanism predominating in the highly organic (HILIC), like in highly aqueous (RP) mobile phase ranges. Besides the type of the stationary phase, the separation selectivity of phenolic acids strongly depends on temperature and on the mobile phase composition. From among the 4 hydrosilated columns compared in this work, the UDC cholesterol column has high temperature stability (up to 100 °C) and is most suitable for selective and efficient separations of phenolic acids both in the HILIC and in the RP modes.


Assuntos
Cromatografia Líquida/instrumentação , Cromatografia Líquida/métodos , Hidroxibenzoatos/isolamento & purificação , Dióxido de Silício/química , Acetonitrilas/química , Colesterol/química , Cromatografia de Fase Reversa , Interações Hidrofóbicas e Hidrofílicas , Temperatura
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