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1.
Skeletal Radiol ; 50(8): 1585-1591, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33410963

RESUMO

OBJECTIVE: To determine the frequency with which MRI of tenosynovial giant cell tumor demonstrates hemosiderin, visible intralesional fat signal, and proximity to synovial tissue. MATERIAL AND METHODS: This is a retrospective study of 31 cases of tenosynovial giant cell tumors which had concomitant MRI. Images were examined for lesion size, morphology, origin, bone erosions, MRI signal characteristics, contrast enhancement, and blooming artifact, comparing prospective and retrospective reports. Histology was reviewed for the presence of hemosiderin and xanthoma cells. RESULTS: Eight lesions were diffuse and 23 were localized nodules. Three lesions were located in subcutaneous tissue and 4 adjacent to tendons beyond the extent of their tendon sheath. All lesions exhibited areas of low T1- and T2-weighted signal. Blooming artifact on gradient echo imaging was present in 86% of diffuse and only 27% of nodular disease. There was interobserver variability of 40% in assessing blooming. Iron was visible on H&E or iron stain in 97% of cases. Fat signal intensity was seen in only 3% of cases, although xanthoma cells were present on in 48%. The correct diagnosis was included in the prospective radiology differential diagnosis in 86% of diffuse cases and 62% of nodular cases. CONCLUSION: Blooming on GRE MRI has low sensitivity for nodular tenosynovial giant cell tumors and is not universal in diffuse tumors. There was high interobserver variability in assessment of blooming. Intralesional fat signal is not a useful sign and may occur adjacent to tendons which lack a tendon sheath and may occur in a subcutaneous location.


Assuntos
Tumor de Células Gigantes de Bainha Tendinosa , Tumores de Células Gigantes , Sinovite Pigmentada Vilonodular , Tumor de Células Gigantes de Bainha Tendinosa/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Estudos Prospectivos , Estudos Retrospectivos
2.
J Inorg Biochem ; 164: 26-33, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27592288

RESUMO

Chromium (III) has been shown to act as a pharmacological agent improving insulin sensitivity in rodent models of obesity, insulin resistance, and diabetes. To act in beneficial fashion, chromium must reach insulin-sensitive tissues. Chromium is transported from the bloodstream to the tissues by the iron-transport protein transferrin. When blood concentrations of glucose are high (as in a diabetic subject), transferrin can be glycated, modifying its ability to bind and transport iron. However, the effects of glycation of transferrin on its ability to bind and transport Cr have not been examined previously. Storage of transferrin at 37°C in the presence and absence of glucose has significant effects on the binding of Cr. Transferrin stored in the absence of glucose only binds one equivalent of Cr tightly, compared to the normal binding of two equivalents of Cr by transferrin. Glycated transferrin (stored in the presence of glucose) binds two equivalents of Cr but the changes in its extinction coefficient at 245nm that accompany binding suggest that the Cr-bound transferrin possesses a conformation that deviates appreciably from untreated transferrin. These changes have dramatic effects, greatly reducing the ability of transferrin to transport Cr in vivo in rats. The results suggest that glycation of transferrin in subjects with high blood glucose concentrations should reduce the ability of Cr from pharmacological agents to enter tissues.


Assuntos
Cromo , Transferrina , Animais , Transporte Biológico Ativo , Bovinos , Cromo/química , Cromo/farmacocinética , Cromo/farmacologia , Diabetes Mellitus/sangue , Diabetes Mellitus/tratamento farmacológico , Glicosilação , Humanos , Resistência à Insulina , Masculino , Obesidade/sangue , Obesidade/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Transferrina/química , Transferrina/farmacocinética , Transferrina/farmacologia
3.
Biol Trace Elem Res ; 168(1): 221-6, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25910900

RESUMO

As Cr(III) compounds have been shown to increase insulin sensitivity and decrease plasma cholesterol and triglycerides in rodent models of diabetes and insulin resistance and as colorectal cancer risk has been associated with insulin resistance and diabetes, the effects of the Cr(III) compound Cr3 ([Cr3O(O2CCH2CH3)6(H2O)3](+)) were investigated in male and female FVB/NJ mice with azoxymethane-induced colorectal cancer. In contrast to a previous study on the effects of Cr3 on 1,2-dimethylhydrazine-induced colorectal cancer in Sprague Dawley rats, no effects of Cr3 at daily doses of 1 and 10 mg Cr/kg body mass were observed, leaving in question whether administration of Cr(III) compounds can delay or prevent the onset of colorectal cancer.


Assuntos
Anticarcinógenos/farmacologia , Azoximetano/antagonistas & inibidores , Azoximetano/toxicidade , Carcinógenos/toxicidade , Compostos de Cromo/farmacologia , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/prevenção & controle , Animais , Peso Corporal/efeitos dos fármacos , Feminino , Resistência à Insulina/genética , Masculino , Camundongos , Camundongos Endogâmicos
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