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1.
Environ Sci Technol ; 46(22): 12364-72, 2012 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-23016984

RESUMO

Concentrations of Dechlorane (Dec) 603 (0.75 ng/g lipid weight (lw); mean) and Dec 602 (0.38 ng/g lw; mean) were quantified in more than 95% of the franciscana (Pontoporia blainvillei) dolphin samples, whereas the frequency of detection decreased to 75% for Dechlorane Plus (DP) (1.53 ng/g lw, mean). The presence of Chlordene Plus (CP) was also observed (0.13 ng/g lw, mean) in half of the samples. On the contrary, Dec 604, decachloropentacyclooctadecadiene (aCl(10)DP), and undecachloropentacyclooctadecadiene (aCl(11)DP) concentrations were below the limit of quantifications in all cases. To the best of our knowledge, this is the first article reporting the presence of Dec 603, Dec 602, and CP in mammals. For comparative purposes, levels of Mirex, polybrominated diphenyl ethers (PBDEs), and decabromodiphenylethane (DBDPE) are also reported. Considering geographic distribution evaluation together with the strong positive correlations found between DP and PBDEs (r(s) = 0.63; p < 0.01), highly anthropogenic areas were identified as potential sources of these chemicals in this dolphin species. However, local sources for Dec 602, 603, Mirex, CP, and DBDPE were not found indicating that in this case historical use and/or atmospheric transport and deposition may play an important role in their fate.


Assuntos
Bromobenzenos/metabolismo , Exposição Ambiental , Retardadores de Chama/metabolismo , Éteres Difenil Halogenados/metabolismo , Hidrocarbonetos Clorados/metabolismo , Poluentes Químicos da Água/metabolismo , Fatores Etários , Animais , Brasil , Cromatografia Gasosa , Monitoramento Ambiental , Geografia , Espectrometria de Massas , Fatores Sexuais
2.
Sci Rep ; 10(1): 11733, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678140

RESUMO

Flow of non-Newtonian fluids through topologically complex structures is ubiquitous in most biological, industrial and environmental settings. The interplay between local hydrodynamics and the fluid's constitutive law determines the distribution of flow paths. Consequently the spatial heterogeneity of the viscous resistance controls mass and solute transport from the micron to the meter scale. Examples range from oil recovery and groundwater engineering to drug delivery, filters and catalysts. Here we present a new methodology to map the spatial variation of the local viscosity of a non-Newtonian fluid flowing through a complex pore geometry. We use high resolution image velocimetry to determine local shear rates. Knowing the local shear rate in combination with a separate measurement of the fluid's constitutive law allows to quantitatively map the local viscosity at the pore scale. Our experimental results-which closely match with three-dimensional numerical simulations-demonstrate that the exponential decay of the longitudinal velocity distributions, previously observed for Newtonian fluids, is a function of the spatial heterogeneity of the local viscosity. This work sheds light on the relationship between hydraulic properties and the viscosity at the pore scale, which is of fundamental importance for predicting transport properties, mixing, and chemical reactions in many porous systems.

3.
J Comp Pathol ; 157(1): 51-56, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28735671

RESUMO

Neuroectodermal developmental anomalies are reported rarely in cetaceans and central nervous system cysts are not described. We describe the gross, microscopical, histochemical and immunohistochemical features of a neuraxial myelencephalic cyst in a stranded neonatal Burmeister's porpoise (Phocoena spinipinnis). Grossly, a subdural, extra-axial, well-demarcated, yellow fluid-filled cystic structure (1.9 × 1.6 × 1 cm) expanded the left foramen of Luschka, the left caudolateral cerebellar recess and the left cranioventral myelencephalon. The cyst displaced the ipsilateral ventral paraflocculus and distended the underlying cranial nerves IX, X, XI and XII. Microscopically, the cystic structure was lined by a monolayer of low cuboidal to flattened epithelium supported by a thin fibrovascular matrix. Immunohistochemistry (IHC) revealed strong and diffuse expression of AE1/AE3 and focal positivity for vimentin. IHC for epithelial membrane antigen, glial fibrillary acid protein, synaptophysin and S100 was negative. Based on these findings, an extra-axial cyst of the choroid plexus of the fourth ventricle (CCPFV) was diagnosed. The pathological relevance of the CCPFV in this case is uncertain. The cause of death involved severe perinatal interspecific (shark) trauma. The present case provides the first evidence of a neuroepithelial cyst in cetacean species.


Assuntos
Plexo Corióideo/anormalidades , Defeitos do Tubo Neural/veterinária , Phocoena/anormalidades , Animais , Animais Recém-Nascidos
4.
J Neuroimmunol ; 49(1-2): 189-95, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8294555

RESUMO

Pure gangliosides obtained from bovine brain including GM1, GD1b, GT1b and asialo-GM1 (GA1) did not induce normal human B cell proliferation in vitro. No B cell proliferation was observed either when GM1 was tested in the presence of interleukin-2 (IL-2), IL-4 or IL-6. Furthermore, the proliferative responses of human B cells induced by Staphylococcus aureus Cowan I (SAC), a T cell-independent B cell mitogen, were inhibited by these gangliosides. The degree of inhibition was influenced by ganglioside-bound sialic acid, although sialic acid per se was not inhibitory. Strongest inhibition was observed in the presence of GT1b (EC50 8.8 microM/10(5) B cells) and lowest in the presence of GA1 (EC50 129.5 microM/10(5) B cells) with intermediate values for GM1 and GD1b. GM1 inhibition of SAC-induced B cell proliferation did not represent cytotoxic effects and was still evident when GM1 was added 24-48 h after the beginning of the cultures. GM1 inhibition of SAC-induced proliferation was not reversed by the addition of IL-2, IL-4, IL-6 or their combination. In addition, GM1 inhibited the ILs-driven proliferative responses of SAC-induced B cell blasts. However, no inhibition of Epstein-Barr virus-induced B cell proliferative responses was observed. In conclusion, these results show that bovine brain-derived gangliosides do not induce proliferative responses of normal human B cells but, on the contrary, inhibit B cell responses induced by SAC.


Assuntos
Linfócitos B/imunologia , Gangliosídeos/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Animais , Bovinos , Células Cultivadas , Humanos , Interleucinas/farmacologia , Ácido N-Acetilneuramínico , Ácidos Siálicos/farmacologia , Staphylococcus aureus/imunologia
5.
Invest Ophthalmol Vis Sci ; 39(13): 2688-95, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9856779

RESUMO

PURPOSE: To investigate flux through the polyol pathway in the dog lens by 19F-nuclear magnetic resonance (19F-NMR) spectroscopy, using 3-fluoro-3-deoxy-D-glucose (3-FG) as a substrate. METHODS: 3-FG metabolism was monitored by 19F-NMR analysis. Dog lenses were incubated in Dulbecco's modified Eagle's medium containing 10 mM 3-FG. Enzymatic reductase and dehydrogenase activities were spectrophotometrically determined, whereas the analyses of 3-FG metabolites were conducted by 19F-NMR analysis. Aldose reductase (AR) was immunohistochemically localized in dog lens with antibodies raised against dog kidney AR. RESULTS: 19F-NMR spectra indicate that incubation of purified dog lenses AR with 3-FG results in the formation of 3-fluoro-3-deoxy-D-sorbitol (3-FS) and that incubation of dog liver sorbitol dehydrogenase (SDH) with 3-FS results in the formation of 3-fluoro-3-deoxy-D-fructose (3-FF). This confirms that 3-FG is metabolized to 3-FF by the polyol pathway enzymes. The affinity (Km) of AR for 3-FG is approximately 20-fold better than that for D-glucose, whereas the Km of SDH for 3-FS was fourfold less than for D-sorbitol. 3-FG in cultured dog lenses is metabolized primarily to 3-FS; however, small amounts of 3-FF and 3-fluoro-3-deoxy-D-gluconic acid (3-FGA) are also formed. 3-FS formation was reduced by the AR inhibitor AL 1576, and 3-FF formation was eliminated by the SDH inhibitor CP-166,572. In dog lens epithelial cells cultured with 3-FG, only 3-FS is formed. Similarly, only 3-FS is formed when lens capsule containing primarily epithelial lens contaminated with superficial epithelial cells was incubated in 3-FG. Similar incubation of the remaining cortex resulted primarily in the formation of 3-FS and 3-FGA. This enzymatic distribution was confirmed by spectrophotometric activity analysis and the immunohistochemical localization of AR. CONCLUSIONS: The data confirm that flux through the polyol pathway primarily results in sorbitol accumulation. The absence of fructose and gluconic acid from cultured lens epithelium suggests that the epithelial cells primarily contain AR, whereas differentiated fiber cells also contain SDH and glucose dehydrogenase.


Assuntos
Desoxiglucose/análogos & derivados , Cristalino/metabolismo , Polímeros/metabolismo , Aldeído Redutase/antagonistas & inibidores , Aldeído Redutase/metabolismo , Animais , Desoxiglucose/metabolismo , Cães , Inibidores Enzimáticos/farmacologia , Células Epiteliais/enzimologia , Fluorenos/farmacologia , Flúor/metabolismo , Frutose/análogos & derivados , Frutose/metabolismo , Gluconatos/metabolismo , Hidantoínas/farmacologia , Técnicas Imunoenzimáticas , Cristalino/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Sorbitol/análogos & derivados , Sorbitol/metabolismo
6.
Invest Ophthalmol Vis Sci ; 40(3): 697-704, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10067973

RESUMO

PURPOSE: Dogs fed a diet containing 30% galactose experience retinal vascular changes similar to those in human diabetic retinopathy, with selective pericyte loss as an initial lesion. In the present study the relationship among reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reductases, polyol formation, and flux through the polyol pathway in cultured dog retinal capillary cells were investigated. METHODS: Pericytes and endothelial cells were cultured from retina of beagle dogs. NADPH-dependent reductases were characterized by chromatofocusing after gel filtration. Sugars in cultured cells were analyzed by gas chromatography, and flux through the polyol pathway was investigated by 19F nuclear magnetic resonance (NMR) with 3-fluoro-3-deoxy-D-glucose (3FG) as a substrate. The presence of aldose reductase and sorbitol dehydrogenase in these cells was examined by northern blot analysis. RESULTS: Two distinct peaks corresponding to aldose reductase and aldehyde reductase, the latter being dominant, were observed in pericytes by chromatofocusing. Culture in medium containing either 10 mM D-galactose or 30 mM D-glucose resulted in the accumulation of sugar alcohol in pericytes that was markedly reduced by aldose reductase inhibitors. 19F NMR spectra obtained from pericytes cultured for 5 days in medium containing 2 mM 3FG displayed the marked accumulation of 3-fluoro-deoxysorbitol but not 3-fluoro-deoxyfructose. No 3FG metabolism was observed in similarly cultured endothelial cells. With northern blot analysis, aldose reductase was detected in pericytes but not in endothelial cells. Sorbitol dehydrogenase was below the detectable limit in pericytes and endothelial cells. CONCLUSIONS: Aldose, aldehyde, and glyceraldehyde reductases are present in dog retinal capillary pericytes, with aldehyde reductase being the major reductase present. Polyol accumulation easily occurs in pericytes but not in endothelial cells.


Assuntos
Aldeído Redutase/metabolismo , Endotélio Vascular/enzimologia , L-Iditol 2-Desidrogenase/metabolismo , Pericitos/enzimologia , Vasos Retinianos/enzimologia , Desidrogenase do Álcool de Açúcar/metabolismo , Álcoois Açúcares/metabolismo , Aldeído Redutase/antagonistas & inibidores , Animais , Northern Blotting , Capilares/enzimologia , Células Cultivadas , Cromatografia Gasosa , Cromatografia em Gel , Cães , Eletroforese em Gel de Poliacrilamida , Endotélio Vascular/citologia , Inibidores Enzimáticos/farmacologia , Hexoses/análise , L-Iditol 2-Desidrogenase/antagonistas & inibidores , Espectroscopia de Ressonância Magnética , Pericitos/citologia , Desidrogenase do Álcool de Açúcar/antagonistas & inibidores
7.
Immunol Lett ; 38(2): 127-30, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8294140

RESUMO

Adrenaline has been shown to inhibit the release of tumor necrosis factor (TNF) elicited by lipopolysaccharide (LPS) when tested in vitro on cultured human blood cells and rat macrophages. In this report we have examined the effect of the in vivo administration of adrenaline on TNF serum levels induced by LPS. In agreement with in vitro data, adrenaline (0.1 mg/kg, s.c.) was found to inhibit in the mouse the LPS-induced TNF release. The beta-adrenergic antagonist propranolol administered 1 h before adrenaline completely blocked the adrenaline activity, whereas the alpha-adrenergic antagonist phentolamine was ineffective. These data demonstrate that: (i) adrenaline is an effective antagonist of LPS-induced TNF release in vivo, and (ii) its effect is mediated by beta-adrenergic receptors.


Assuntos
Epinefrina/farmacologia , Lipopolissacarídeos/antagonistas & inibidores , Receptores Adrenérgicos beta/fisiologia , Fator de Necrose Tumoral alfa/metabolismo , Animais , Testes Imunológicos de Citotoxicidade , Epinefrina/antagonistas & inibidores , Camundongos , Fentolamina/farmacologia , Propranolol/farmacologia , Receptores Adrenérgicos alfa/fisiologia , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/biossíntese
8.
Chest ; 108(1): 131-7, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7606947

RESUMO

A study to evaluate the usefulness of the integration of the transbronchial and percutaneous approaches in the diagnosis of peripheral pulmonary nodules or masses (PPN/M) was conducted. The authors used both procedures, performed by a single diagnostic team, a pulmonologist, radiologist, and cytopathologist, who were all simultaneously present in the radiologic suite during the maneuvers. From January 1985 to June 1993, under fluoroscopic guidance, the authors performed 557 transbronchial pulmonary biopsies (TBPB), 483 transbronchial needle aspirations (TBNA), and 652 percutaneous needle aspirations (PCNA) on 1,027 consecutive patients referred because of a PPN/M (mean diameter, 3.5 cm; range, 0.8 to 8 cm). The procedure used was as follows: (1) bronchoscopy with exploration of the upper airways and bronchial tree, followed by TBNA and immediate cytologic assessment (ICA); (2) at least three TBPB; (3) if TBNA was diagnostic, the procedure was stopped; if not, a second pass with the needle was performed and then the bronchoscope was removed; (4) if the second TBNA was not diagnostic, PCNA with ICA was performed up to a maximum of three needle passes. Diagnostic sensitivity for malignant lesions was as follows: 53.9% for TBPB, 69.3% for TBNA, 75.4% for TBPB and TBNA together, 93.2% for PCNA, and 95.2% overall. The percentage of benign nodules correctly defined was 41.4% for TBPB, 17.4% for TBNA, 45.8% for PCNA, and 59.5% overall. Examination of the upper airways and bronchial tree was positive for lesions endoscopically visible in 12.6% of cases. The authors' experience shows that transbronchial and percutaneous approaches must be considered complementary and that their integrated use not only increases diagnostic yield but also permits important information to be obtained for disease staging. The creation of teams able to use both approaches with the cytopathologist present for ICA should be encouraged to optimize the diagnostic management of PPN/M with a reduction in diagnostic and hospitalization time and consequent cost saving.


Assuntos
Neoplasias Pulmonares/patologia , Nódulo Pulmonar Solitário/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Biópsia/métodos , Biópsia por Agulha , Feminino , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade
9.
Eur Cytokine Netw ; 4(5): 371-5, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8117939

RESUMO

The treatment with phosphatidylserine (PS) has recently been shown to inhibit in vivo the lipopolysaccharide (LPS)-induced release of tumor necrosis factor (TNF) (Monastra and Bruni, 1992, Lymphokine Cytokine Res. 11:39). The aim of the present work was to investigate the mechanism(s) involved in the inhibition by PS. No in vitro inhibition of LPS-induced TNF release was observed when PS was used in vitro with human whole blood cells. The opposite was observed, in vitro PS enhanced TNF release. Previous work has shown that PS induces histamine release by mast cells and it is known that histamine inhibits TNF release. PS treatment of W/WV mice lacking mast cells, which are therefore unable to release histamine, resulted in inhibition of LPS-induced TNF release; thus excluding a major role of histamine in mediating PS inhibition. However, in adrenalectomized mice PS treatment failed to inhibit the LPS-induced TNF release, while the effect of PS was evident in sham-operated mice. PS treatment in adrenalectomized mice was associated with an increase in TNF serum levels when compared to untreated animals. Overall these results suggest that PS inhibition of LPS-induced TNF release is dependent on adrenal hormones, while PS, in the absence of adrenal hormones, seems to have a priming effect on the cells that produce TNF after LPS stimulus.


Assuntos
Glândulas Suprarrenais/fisiologia , Lipopolissacarídeos/antagonistas & inibidores , Fosfatidilserinas/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , Corticosteroides/fisiologia , Adrenalectomia , Animais , Histamina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos
10.
J Diabetes Complications ; 10(6): 304-13, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8972381

RESUMO

Recent reports suggest that excess amounts of sugar alcohol are linked to leukocyte dysfunctions associated with diabetes. As the polyol pathway has not been firmly established in leukocytes, we have investigated NADPH-dependent reductases and sugar alcohol formation in dog leukocytes. NADPH-dependent reductase activity was observed with DL-glyceraldehyde as substrate in both mononuclear and polymorphonuclear leukocytes isolated from dog. By chromatofocusing, this activity corresponded primarily to aldehyde reductase rather than aldose reductase. The enzymatic conversion of glucose to the sugar alcohol sorbitol in leukocytes was confirmed in vitro by 19F nuclear magnetic resonance (NMR) spectroscopy using 3-deoxy-3-fluoro-D-glucose as substrate. The NMR spectrum obtained after incubation with 10 Mm 3-deoxy-3-fluoro-D-glucose at 37 degrees C for 24 h displayed newly formed 3-deoxy-3-fluoro-D-sorbitol and 3-deoxy-3-fluoro-D-fructose peaks with both mononuclear and polymorphonuclear leukocytes. Sugar alcohol production in leukocytes from galactose-fed dogs was also observed in vivo. Galactitol accumulation was consistently observed by gas chromatography to occur in mononuclear cells while only trace amounts of galactitol were observed in polymorphonuclear leukocytes. Activation of NADPH oxidase activity in neutrophils isolated from galactose-fed dogs by zymosan was also significantly reduced compared to that of nongalactosemic control dogs. These results indicate that glucose is converted to fructose through sorbitol in both mononuclear and polymorphonuclear leukocytes despite the observations that these cells primarily contain aldehyde reductase rather than aldose reductase. In vivo, sugar alcohol accumulation in mononuclear cells is greater than in polymorphonuclear leukocytes.


Assuntos
Galactosemias/sangue , Leucócitos/enzimologia , NADH NADPH Oxirredutases/sangue , Álcoois Açúcares/sangue , Aldeído Redutase/sangue , Aldeído Redutase/isolamento & purificação , Animais , Cães , Galactosemias/enzimologia , Células HL-60 , Humanos , Cinética , Leucócitos Mononucleares/enzimologia , Espectroscopia de Ressonância Magnética , Masculino , NADPH Oxidases/sangue , Neutrófilos/enzimologia , Valores de Referência , Especificidade por Substrato
11.
J Diabetes Complications ; 13(3): 151-8, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10509875

RESUMO

Dogs fed a diet containing 30% galactose develop diabetes-like retinal capillary changes. As retinal capillary occlusion is commonly observed in diabetic retinopathy, neutrophil apoptosis and the interaction of neutrophils with retinal capillary endothelial cells were investigated. Neutrophils were isolated with Ficoll-Hypaque centrifugation from dogs fed a 30% galactose diet and dogs fed a normal, control diet containing 30% non-nutrient filler. Apoptosis of neutrophils was microscopically examined after incubation at 37 degrees C for 3 hours with either 100 U/mL tumor necrosis factor alpha (TNF-alpha), 2 microg/mL cycloheximide or 50 ng/mL phorbol 12-myristate 13-acetate (PMA). Neutrophil adhesion to dog retinal capillary endothelial cells was examined by counting the cells attached to the surface of endothelial cells after the incubation in the presence of either 100 U/mL TNF-alpha or 5 microg/mL lipopolysaccharides (LPS) at 37 degrees C for 3 hours. With all three stimulants TNF-alpha, cycloheximide and PMA, the rate of apoptosis was significantly lower for neutrophils isolated from galactose-fed dogs compared to control dogs fed a normal diet. Preincubation of neutrophils from control dogs in medium containing 30% galactose for 3 hours did not affect the rate of apoptosis. Neutrophil adhesion to retinal capillary endothelial cells induced by incubation in the presence of either 100 U/mL TNF-alpha or 5 microg/ml LPS was significantly higher with neutrophils isolated from galactose-fed dogs than those from control dogs. The data indicate that long-term galactose feeding is essential with development of various neutrophil dysfunctions. These neutrophil changes may contribute to the development of retinal microangiopathy associated with diabetes and galactosemia.


Assuntos
Apoptose , Adesão Celular , Diabetes Mellitus Experimental/patologia , Endotélio Vascular/patologia , Neutrófilos/patologia , Vasos Retinianos/patologia , Animais , Capilares/patologia , Cicloeximida/farmacologia , Fragmentação do DNA , Diabetes Mellitus Experimental/induzido quimicamente , Cães , Ativação Enzimática/efeitos dos fármacos , Galactose , Masculino , Proteína Quinase C/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
12.
Chem Biol Interact ; 143-144: 363-71, 2003 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-12604223

RESUMO

Because of the limited availability of human tissues, leukemia cell lines are often utilized as the models for human leukocytes. In this study, we investigated the NADPH-dependent reductases and polyol pathway in commonly utilized human leukemia cell lines. The relative amounts of aldose and aldehyde reductases were estimated by separating two enzymes with chromatofocusing. The flux of glucose through the polyol pathway was examined by 19F-NMR using 3-fluoro-3-deoxy-D-glucose (3FG) as substrate. Sugar alcohol analysis was conducted by gas chromatography. In myelocytic leukemia cells, the major reductase was aldehyde reductase, and levels of aldose reductase were extremely low. Although lymphocytic cells also contained both aldose and aldehyde reductases, the levels of aldose reductase appeared to be higher in lymphocytic cells than myeolcytic cells. In two lymphocytic cells MOLT-4 and SKW6.4, aldose reductase is clearly dominant. When incubated in medium containing D-galactose, all cell lines quickly accumulated galactitol. There was correlation between galactitol levels and aldose reductase levels. The aldose reductase inhibitor FK 366 significantly reduced the formation of galactitol. 19F-NMR of the cells cultured with 3FG as substrate demonstrated the formation of 3-fluoro-3-dexoy-sorbitol in all the cell lines examined in this study. The relative amounts of sorbitol and fructose varied significantly among the cells. The data confirm that the polyol pathway is present in both myelocytic and lymphocytic leukemia cell lines. However, there is a large variation among the cell lines in the levels of enzymes and flux of glucose through the polyol pathway.


Assuntos
Leucemia/enzimologia , NADP/metabolismo , Oxirredutases/metabolismo , Polímeros/metabolismo , Cromatografia Gasosa , Cromatografia por Troca Iônica , Humanos , Leucemia/metabolismo , Leucemia/patologia , Espectroscopia de Ressonância Magnética , Células Tumorais Cultivadas
13.
Eur J Radiol ; 34(1): 9-25, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10802203

RESUMO

Hardware and software evolution has broadened the possibilities of 2D and 3D reformatting of spiral CT and MR data set. In the study of the thorax, intrinsic benefits of volumetric CT scanning and better quality of reconstructed images offer us the possibility to apply additional rendering techniques to everyday clinical practice. Considering the large number and redundancy of possible post-processing imaging techniques that we can apply to raw CT sections data, it is necessary to precisely set a well-defined number of clinical applications of each of them, by careful evaluation of their benefits and possible pitfalls in each clinical setting. In diagnostic evaluation of pathological processes affecting the airways, a huge number of thin sections is necessary for detailed appraisal and has to be evaluated, and information must then be transferred to referring clinicians. By additional rendering it is possible to make image evaluation and data transfer easier, faster, and more effective. In the study of central airways, additional rendering can be of interest for precise evaluation of the length, morphology, and degree of stenoses. It may help in depicting exactly the locoregional extent of central tumours by better display of relations with bronchovascular interfaces and can increase CT/bronchoscopy sinergy. It may allow closer radiotherapy planning and better depiction of air collections, and, finally, it could ease panoramic evaluation of the results of dynamic or functional studies, that are made possible by increased speed of spiral scanning. When applied to the evaluation of peripheral airways, as a completion to conventional HRCT scans, High-Resolution Volumetric CT, by projection slabs applied to target areas of interest, can better depict the profusion and extension of affected bronchial segments in bronchiectasis, influence the choice of different approaches for tissue sampling by better evaluation of the relations of lung nodules with the airways, or help to detect otherwise overlooked slight pathological findings. In the exploration of the air-spaces of the head and neck, targeted multiplanar study can now be performed without additional scanning by retro-reconstructed sections from original transverse CT slices. Additional rendering can help in surgical planning, by simulation of surgical approaches, and allows better integration with functional paranasal sinuses endoscopic surgery, by endoscopic perspective rendering. Whichever application we perform, the clinical value of 2D and 3D rendering techniques lies in the possibility of overcoming perceptual difficulties and 'slice pollution', by easing more efficient data transfer without loss of information. 3D imaging should not be considered, in the large majority of cases, as a diagnostic tool: looking at reformatted images may increase diagnostic accuracy in only very few cases, but an increase in diagnostic confidence could be not negligible. The purpose of the radiologist skilled in post-processing techniques should be that of modifying patient management, by more confident diagnostic evaluation, in a small number of patients, and, in a larger number of cases, by simplifying communication with referring physicians and surgeons. We will display in detail possible clinical applications of the different 2D and 3D imaging techniques, in the study of the tracheobronchial tree, larynx, nasal cavities and paranasal sinuses by Helical CT, review relating bibliography, and briefly discuss pitfalls and perspectives of CT rendering techniques for each field.


Assuntos
Processamento de Imagem Assistida por Computador , Sistema Respiratório/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Humanos , Neoplasias do Sistema Respiratório/diagnóstico por imagem
14.
Curr Eye Res ; 18(4): 277-82, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10372987

RESUMO

PURPOSE: Aldose reductase (AR) activity and flux through the polyol pathway can conveniently be monitored in dog lenses by measuring the metabolism of 3-fluoro-3-deoxy-D-glucose by 19F nuclear magnetic resonance (NMR) spectroscopy. Since AR has broad substrate specificity and preferentially utilizes galactose over glucose as substrate, the ability of AR to utilize 3-fluoro-3-deoxy-D-galactose (3-FDGal) as substrate as well as the metabolism of 3-FDGal in intact dog lens and cultured lens epithelial cells has been investigated. METHODS: The suitableness of 3FDGal as a substrate was examined by incubating 3FDGal with purified dog lens aldose reductase in the presence of an NADPH generating system or with galactitol dehydrogenase in the presence of NAD+. Dog lenses and dog lens epithelial cells were cultured in 3-FDGal medium with and without the AR inhibitor AL 1576. Metabolism was studied using 19F NMR. RESULTS: AR activity with 3-FDGal as substrate is higher than that with D-galactose and its Km of 4.2 mM is ca 10-fold higher than that of D-galactose. Purified dog lens AR incubated with 3-FDGal resulted in the formation of 3-fluoro-3-deoxy-D-galactitol. Galactitol formation was prevented by the addition of AL 1576. Incubation of 3-FDGal with galactitol dehydrogenase resulted in the formation of 3-fluoro-3-deoxy-D-galactonic acid. Dog lenses cultured in 3-FDGal medium formed NMR peaks corresponding to 3-fluoro-3-deoxy-D-galactitol and 3-fluoro-3-deoxy-D-galactonic acid. The presence of AL 1576 inhibited the formation of galactitol but not galactonic acid. Lens epithelial cells cultured in 3-FDGal medium formed only 3-fluoro-3-deoxy-D-galactitol. These cells developed multiple cytoplasmic vacuoles which was prevented by the aldose reductase inhibitor AL 1576. CONCLUSIONS: The high affinity of this fluorinated sugar for aldose reductase makes this an excellent probe for investigating aldose reductase activity in dog lens tissues.


Assuntos
Catarata/induzido quimicamente , Aldeído Redutase/metabolismo , Animais , Células Cultivadas , Citoplasma/ultraestrutura , Cães , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Fucose/análogos & derivados , Fucose/metabolismo , Fucose/farmacologia , Técnicas In Vitro , Cristalino/citologia , Cristalino/efeitos dos fármacos , Cristalino/metabolismo , Cristalino/patologia , Desidrogenase do Álcool de Açúcar/metabolismo , Vacúolos/ultraestrutura
15.
Monaldi Arch Chest Dis ; 48(2): 130-3, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8390898

RESUMO

A 61 year old man presented with chronic bronchitis, which he had been suffering from for many years, and reported the recent onset of polyuria with polydipsia. A chest X-ray showed a peripheral pulmonary nodule in the right lower lobe, that was diagnosed as small cell lung cancer following histological examination of the pulmonary tissue specimen, obtained with transbronchial biopsy. After establishing the central origin of the diabetes insipidus, its cause was revealed by magnetic resonance imaging of the brain, that demonstrated metastasis to the hypothalamic-neurohypophyseal area.


Assuntos
Carcinoma de Células Pequenas/complicações , Carcinoma de Células Pequenas/secundário , Diabetes Insípido/etiologia , Neoplasias Hipotalâmicas/complicações , Neoplasias Hipotalâmicas/secundário , Neoplasias Pulmonares/patologia , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/secundário , Humanos , Sistema Hipotálamo-Hipofisário/fisiopatologia , Masculino , Pessoa de Meia-Idade
16.
Reumatismo ; 53(4): 280-288, 2001.
Artigo em Italiano | MEDLINE | ID: mdl-12089621

RESUMO

Pulmonary involvement is one of the most frequent extra-articular manifestations of rheumatoid arthritis (RA) and represents a serious complication, being the second cause of death after infection. High-resolution computed tomography (HRCT), owing to its increased sensitivity and diagnostic accuracy respect to the conventional chest radiograph (CXR), allows to detect pulmonary abnormalities in RA patients more frequently than CXR. The aim of this study was to assess pulmonary involvement by HRCT in lifelong non-smoking RA patients without symptoms and clinical signs of pulmonary disease. Seventy-two patients (54 women and 18 men) with a mean age of 56.8+/-10.4 years (range, 40-77 years) and mean duration of disease of 6.9+/-4.7 years (range, 2-12 years) entered the study. 52/72 (72%) were positive for rheumatoid factor (> 20 UI/ml). Standard CXR and HRCT were carried out in each patient. CXR showed a mild interstitial fibrosis in 7 patients (9.7%), whereas HRCT demonstrated pulmonary abnormalities in an higher number of them (22/72 = 30.5%). The most frequent abnormal findings on HRCT were irregular pleural margins (13.8%) and septal/subpleural lines (18%), both compatible with pulmonary fibrosis. Ground-glass opacities were found in 8.3% of the patients. Pulmonary nodules (diameter, range 0,5-2 cm) predominantly located in the subpleural portions of the lung, were demonstrated in the same percentage (8.3%) of patients. Small airway involvement, represented by bronchiectasis/bronchioloectasis, was shown in 15.2% of patients. Subpleural cysts were present in two cases (2.8%). No patient had evidence of honeycombing on HRCT. In conclusion, HRCT is an accurate, non-invasive and safe method of diagnosing lung abnormalities in RA patients without signs and clinical symptoms of pulmonary disease.

17.
Ann Ital Chir ; 70(6): 851-5, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10804661

RESUMO

Although transbronchial and percutaneous approaches to peripheral pulmonary lesions (PPL) are widely diffused, effective and safe diagnostic techniques, no standardised strategy yet exists that defines the specific role of each in this clinical setting. With the aim of defining the role of each approach and of verifying if the two techniques are alternative or may be integrated in a logical diagnostic sequence based on the advantages and the limits of each biopsy method, the authors analysed their experience with the integrated use of transbronchial and percutaneous approach to PPL performed on 1,680 consecutive patients affected by PPL. The procedure used was as follows: 1) bronchoscopy with exploration of the bronchial tree and transbronchial needle aspiration (TBNA) of hilar/mediastinal lympho nodes for staging N factor followed by TBNA and transbronchial pulmonary biopsy (TBPB) of the PPL under fluoroscopic guidance and immediate cytological assessment (ICA); 2) if TBNA was diagnostic, the procedure was stopped; if not, a second pass with the needle was performed and then the bronchoscope removed; 3) if the second TBNA was not diagnostic, percutaneous approach (PCNA) with ICA was performed up to a maximum of three needle passes. Diagnostic sensitivity for malignant lesions was: 50.0% for TBPB, 70.1% for TBNA, 76.0% for TBPB and TBNA together, 92.8% for PCNA, and 95.0% overall. The percentage of benign nodules correctly defined was 43.0% for TBPB, 16.7% for TBNA, 47.8% for PCNA. Examination of the upper airways and bronchial tree was positive for lesions endoscopically visible in 11.4% of cases. TBNA of hilar/mediastinal lympho nodes was positive for metastatic involvement in 43.9%. The authors' experience demonstrates that transbronchial and percutaneous approaches must be considered complementary and that their integrated use not only increases diagnostic yield but also permits important information to be obtained for the staging of lung cancer. The creation of teams able to utilise both approaches with the cytopathologist present for ICA should be encouraged in order to optimise the diagnostic management of PPL.


Assuntos
Neoplasias Pulmonares/patologia , Pulmão/patologia , Linfonodos/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Biópsia por Agulha/métodos , Biópsia por Agulha/estatística & dados numéricos , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Sensibilidade e Especificidade
18.
Sci Total Environ ; 493: 405-10, 2014 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-24954561

RESUMO

Total PBDE concentrations determined in archived blubber samples from franciscana dolphins (Pontoporia blainvillei) unintentionally captured in the Brazilian coastal region off Rio Grande do Sul State (FMA III) between 1994 and 2004 (n = 73) ranged from 7.9 to 65 ng g(-1) lipid weight in mature males, with an increase over the ten-year period. Total PBDE concentrations in blubber samples collected from the FAM II (n = 41) between 2002 and 2005 were higher (67.8 to 763.7 ng g(-1)lw) than those from FMA III. This is possibly due to the proximity to important industrial development sites in the state of São Paulo. Despite the differences in total concentrations, PBDE profiles were comparable and the PBDE concentrations decreased in the following order BDE 47>BDE99>BDE 100 for both FMA and for males and females as well as adults, juveniles and pups.


Assuntos
Golfinhos/metabolismo , Éteres Difenil Halogenados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Brasil , Monitoramento Ambiental , Feminino , Geografia , Masculino
19.
J Phys Condens Matter ; 26(46): 464106, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25347466

RESUMO

Pectin is a natural biopolymer that forms, in the presence of divalent cations, ionic-bound gels typifying a large class of biological gels stabilized by non-covalent cross-links. We investigate and compare the kinetics of formation and aging of pectin gels obtained either through external gelation via perfusion of free Ca(2+) ions, or by internal gelation due to the supply of the same ions from the dissolution of CaCO3 nanoparticles. The microscopic dynamics obtained with photon correlation imaging, a novel optical technique that allows obtaining the microscopic dynamics of the sample while retaining the spatial resolution of imaging techniques, is contrasted with macroscopic rheological measurements at constant strain. Pectin gelation is found to display peculiar two-stage kinetics, highlighted by non-monotonic growth in time of both microscopic correlations and gel mechanical strength. These results are compared to those found for alginate, another biopolymer extensively used in food formulation.


Assuntos
Alginatos/química , Cálcio/química , Géis , Pectinas/química , Reologia , Simulação por Computador , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Cinética , Microscopia Eletrônica , Estrutura Molecular , Termodinâmica
20.
J Parasitol ; 99(5): 910-3, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23421418

RESUMO

The aim of this work was to perform a systematic study to detect and quantify the digenetic trematode infections in South American sea lions from the southern Brazilian coast. Twenty-four South American sea lions, Otaria flavescens (Carnivora: Otaridae), were found dead along the coast of Rio Grande do Sul State, Brazil, between June 2010 and September of 2011. Two trematode species were found in the intestines of O. flavescens, i.e., Stephanoprora uruguayense (Digenea: Echinostomatidae) and Ascocotyle (Phagicola) longa (Digenea: Heterophyidae). Ascocotyle (P.) longa reached a prevalence of 33.3% and mean intensity of 248,500, whereas S. uruguayense showed a prevalence of 4.2% and mean intensity of 202. The 2 trematode species infecting sea lions were likely transmitted by feeding on mullets, Mugil platanus, that commonly harbor heterophyid metacercariae. The present work is the first report of digenetic trematodes infecting O. flavescens in Brazil. The high prevalence and mean intensity values of the 2 trematode species infecting sea lions in the present study suggest caution in human consumption of mullets and other fish, which can be infected with the metacercariae of these trematodes known to have zoonotic potential.


Assuntos
Enteropatias Parasitárias/veterinária , Leões-Marinhos/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Oceano Atlântico/epidemiologia , Brasil/epidemiologia , Dieta/efeitos adversos , Feminino , Parasitologia de Alimentos , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Intestinos/parasitologia , Masculino , Prevalência , Smegmamorpha/parasitologia , Trematódeos/crescimento & desenvolvimento , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
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