Mapping the local viscosity of non-Newtonian fluids flowing through disordered porous structures.

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.

Choroid Plexus Cyst in a Neonatal Burmeister's Porpoise (Phocoena spinipinnis).

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.

Choroid Plexus Cyst in a Neonatal Burmeister's Porpoise (Phocoena spinipinnis)

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.

anomalias de desenvolvimento neuroectodérmicas são raramente relatadas em cetáceos e cistos do sistema nervoso central não são descritos. Descrevemos as características macroscópicas, microscópicas, histoquímicas e imuno-histoquímicas de um cisto mielencefálico neuroaxial em uma toninha de Burmeister neonatal encalhada (Phocoena spinipinnis). Grosso modo, uma estrutura cística amarela subdural, extra-axial, bem demarcada e cheia de líquido (1,9 × 1,6 × 1 cm) expandiu o forame esquerdo de Luschka, o recesso cerebelar caudolateral esquerdo e o mielencéfalo cranioventral esquerdo. O cisto deslocou o paraflóculo ventral ipsilateral e distendeu os nervos cranianos subjacentes IX, X, XI e XII. Microscopicamente, a estrutura cística foi revestida por uma monocamada de epitélio cubóide a achatado baixo, suportada por uma fina matriz fibrovascular. A imuno-histoquímica (IHC) revelou forte e difusa expressão de AE1 / AE3 e positividade focal para vimentina. O IHC para antígeno da membrana epitelial, proteína do ácido fibrilar glial, sinafofisina e S100 foi negativo. Com base nesses achados, foi diagnosticado um cisto extra-axial do plexo coróide do quarto ventrículo (CCPFV). A relevância patológica do CCPFV neste caso é incerta. A causa da morte envolveu traumatismo interespecífico (tubarão) perinatal grave. O presente caso fornece a primeira evidência de um cisto neuroepitelial em espécies de cetáceos. patologia cetáceo Anomalia congenita neuroectoderma

External and internal gelation of pectin solutions: microscopic dynamics versus macroscopic rheology.

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.

PBDE levels in franciscana dolphin (Pontoporia blainvillei): temporal trend and geographical comparison.

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.

Digenetic trematodes in South American sea lions from southern Brazilian waters.

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.

Dechlorane-related compounds in franciscana dolphin (Pontoporia blainvillei) from southeastern and southern coast of Brazil.

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.

Equilibrium concentration profiles and sedimentation kinetics of colloidal gels under gravitational stress.

We study the sedimentation of colloidal gels by using a combination of light scattering, polarimetry and video imaging. The asymptotic concentration profiles (z,t → ∞) exhibit remarkable scaling properties: profiles for gels prepared at different initial volume fractions and particle interactions can be superimposed onto a single master curve by using suitable reduced variables. We show theoretically that this behavior stems from a power law dependence of the compressive elastic modulus versus , which we directly test experimentally. The sedimentation kinetics comprises an initial latency stage, followed by a rapid collapse where the gel height h decreases at constant velocity and a final compaction stage characterized by a stretched exponential relaxation of h toward a plateau. Analogies and differences with previous works are briefly discussed.

NADPH-dependent reductases and polyol formation in human leukemia cell lines.

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.

[The subclinical involvement of the lung in rheumatoid arthritis: evaluation by high-resolution computed tomography] / L'interessamento polmonare subclinico nell'artrite reumatoide: studio mediante tomografia ad alta risoluzione.

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.

Clinical applications of 2D and 3D CT imaging of the airways--a review.

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.

Neutrophils in galactose-fed dogs: suppressed apoptosis and increased adhesion to retinal capillary endothelial cells.

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.

3-Fluoro-3-deoxy-D-galactose: a new probe for studies on sugar cataract.

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.

[Subclinical interstitial lung involvement in rheumatic diseases. Correlation of high resolution computerized tomography and functional and cytologic findings]. / L'interessamento polmonare interstiziale subclinico nelle malattie reumatiche. Correlazione fra Tomografia computerizzata con alta risoluzione e i reperti funzionali e citologici.

INTRODUCTION: Rheumatic diseases are frequently associated with interstitial lung disease. Since interstitial fibrosis is an irreversible process, understanding the mechanisms leading to fibrosis is necessary for the development of treatment strategies to prevent irreversible pulmonary damage. High-resolution Computed Tomography (HRCT) is superior to chest radiography in assessing the presence and extent of parenchymal abnormalities in diffuse infiltrative lung diseases and provides a sensitive and noninvasive method of quantifying global disease extent. PURPOSE: The aims of this study were to quantify the severity and extent of subclinical interstitial lung disease as depicted on HRCT and to study the relationship between the patterns of lung disease quantified by HRCT and the functional parameters and bronchoalveolar lavage findings in patients with rheumatic diseases. PATIENTS: Eighty nonsmoking patients (24 patients with systemic sclerosis, 24 with primary Sjögren's syndrome, 20 with rheumatoid arthritis and 7 with dermatopolymyositis) were examined. No patient had any signs or symptoms of pulmonary disease. RESULTS: Thirty-three of 80 patients (41.2%) had abnormal HRCT findings, namely isolated septal/subpleural lines, irregular pleural margins and ground-glass appearance. Chest X-ray showed parenchymal abnormalities in only 15 patients (18.7%) who had evidence of fibrosis on HRCT. Abnormal differential cell counts (alveolitis) at bronchoalveolar lavage were found in 46 of 80 patients (57.5%). Three types of alveolitis were observed: pure lymphocyte alveolitis, pure neutrophil alveolitis, and neutrophil alveolitis associated with lymphocytosis (mixed alveolitis). The patients with neutrophil alveolitis had more extensive disease on HRCT than those with lymphocyte alveolitis or with normal cellular patterns at bronchoalveolar lavage. The extent of a reticular pattern on HRCT correlated with the neutrophil rate (p = 0.001) and total count (p = 0.003) on bronchoalveolar lavage. Eosinophil and lymphocyte rate and total count correlated (p < 0.05) with the extent of the ground-glass pattern on HRCT. Lung volumes were not significantly different among patients with ground-glass pattern and those with reticular patterns on HRCT, while the diffusing capacity for carbon monoxide was significantly lower (p < 0.05) in the latter. CONCLUSIONS: HRCT is a sensitive tool in detecting interstitial lung disease in patients with rheumatic diseases with no signs and symptoms of pulmonary involvement. The relationship between the different HRCT patterns and bronchoalveolar lavage cell profiles can identify patients at higher risk of developing irreversible lung fibrosis. A long-term, prospective follow-up study is needed to determine whether these patients will develop over pulmonary disease.

Polyol formation and NADPH-dependent reductases in dog retinal capillary pericytes and endothelial cells.

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.

Integration of TBNA and TCNA in the diagnosis of peripheral lung nodules. Influence on staging.

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.

3-FG as substrate for investigating flux through the polyol pathway in dog lens by 19F-NMR spectroscopy.

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.

Effect of sorbitol dehydrogenase inhibition on sugar cataract formation in galactose-fed and diabetic rats.

Several recent studies with the sorbitol dehydrogenase inhibitors 4-[4-(N,N-dimethylsulfamoyl)-piperazino]-2-methylpyrimidine, SDH-1, and its active metabolite 4-[4-(N, N-dimethylsulfamoyl)piperazino]-2-hydroxymethylpyrimidine , SDH-2, suggest that inhibition of sorbitol dehydrogenase may be beneficial in delaying the onset of diabetic complications due to their ability to ameliorate redox changes associated with polyol metabolism. To compare the relative importance of sorbitol dehydrogenase versus aldose reductase inhibition on sugar cataract formation, cataract formation was monitored in 50% galactose-fed and diabetic rats treated with/without the sorbitol dehydrogenase inhibitors SDH-1 or SDH-2 or the aldose reductase inhibitors AL 1576 or Ponalrestat. For these studies, diabetes was induced in young 50 g rats with streptozotocin while galactosemia was produced by feeding a diet containing 50% galactose. Inhibitors were administered in the diet with the diet containing 0.06% (w/w) of the sorbitol dehydrogenase inhibitors or Ponalrestat, and 0.0125% (w/w) of AL 1576. Cataract formation was monitored by hand-held slit lamp and polyol levels were measured by gas chromatography. Sugar cataract formation was accelerated in diabetic rats treated with sorbitol dehydrogenase inhibitors while no difference in cataract formation was observed in galactose-fed rats treated with/without SDH inhibitors. Cataract formation was inhibited in both diabetic and galactosemic rats by either Ponalrestat or AL 1576. These results support the concept that sugar cataract formation is initiated by the aldose reductase catalysed intracellular accumulation of polyols and that these sugar cataracts can be prevented through inhibition of aldose reductase.

A longitudinal study of pulmonary involvement in primary Sjögren's syndrome: relationship between alveolitis and subsequent lung changes on high-resolution computed tomography.

Eighteen non-smoking women suffering from primary Sjögren's syndrome (pSS) with previously documented alveolitis were re-examined, clinically and by pulmonary function tests (PFT), bronchoalveolar lavage (BAL), chest X-ray and high-resolution computed tomography (HRCT) after a 2 yr follow-up period. Longitudinal evaluation revealed unchanged PFT. The final BAL study showed a normal differential count in six of 14 patients with initial lymphocyte alveolitis, and a persistent alveolar lymphocytosis in the remaining eight patients, associated with an increased percentage of neutrophils in one of them. In four patients with initial mixed alveolitis, the BAL cell profile was unchanged 2 yr later. Five of 18 patients (28%) had abnormal HRCT, represented by isolated septal/subpleural lines in three patients, ground-glass opacities with irregular pleural margins in one patient, and ground-glass opacities associated with septal/subpleural lines in another. All these patients had abnormal BAL results with an increased proportion of both neutrophils and lymphocytes. The presence of alveolar neutrophils was associated with a significantly (P=0.005) greater mean rate of reduction of carbon monoxide diffusing capacity (DLCO) -- more than four times the normal rate of loss of DLCO. Chest X-ray, repeated at the end of the 2 yr follow-up period, showed parenchymal abnormalities in only one patient who had evidence of fibrosis on HRCT. This study provides evidence that lung involvement is not an uncommon extraglandular manifestation of pSS and that a BAL neutrophilia may play an important role in the pathogenesis of pulmonary disease in this autoimmune disorder.

[Virtual bronchoscopy: the correlation between endoscopic simulation and bronchoscopic findings]. / Broncoscopia virtuale: correlazione tra simulazione endoscopica e reperti broncoscopici.

PURPOSE: We carried out a preliminary clinical validation of 3D spiral CT virtual endoscopic reconstructions of the tracheobronchial tree, by comparing virtual bronchoscopic images with actual endoscopic findings. MATERIALS AND METHODS: Twenty-two patients with tracheobronchial disease suspected at preliminary clinical, cytopathological and plain chest film findings were submitted to spiral CT of the chest and bronchoscopy. CT was repeated after endobronchial therapy in 2 cases. Virtual endoscopic shaded-surface-display views of the tracheobronchial tree were reconstructed from reformatted CT data with an Advantage Navigator software. Virtual bronchoscopic images were preliminarily evaluated with a semi-quantitative quality score (excellent/good/fair/poor). The depiction of consecutive airway branches was then considered. Virtual bronchoscopies were finally submitted to double-blind comparison with actual endoscopies. RESULTS: Virtual image quality was considered excellent in 8 cases, good in 14 and fair in 2. Virtual exploration was stopped at the lobar bronchi in one case only; the origin of segmental bronchi was depicted in 23 cases and that of some subsegmental branches in 2 cases. Agreement between actual and virtual bronchoscopic findings was good in all cases but 3 where it was nevertheless considered satisfactory. The yield of clinically useful information differed in 8/24 cases: virtual reconstructions provided more information than bronchoscopy in 5 cases and vice versa in 3. Virtual reconstructions are limited in that the procedure is long and difficult and needing a strictly standardized threshold value not to alter virtual findings. Moreover, the reconstructed surface lacks transparency, there is the partial volume effect and the branches < or = 4 pixels phi and/or meandering ones are difficult to explore. CONCLUSIONS: Our preliminary data are encouraging. Segmental bronchi were depicted in nearly all cases, except for the branches involved by disease. Obstructing lesions could be bypassed in some cases, making an indication for endoscopic laser therapy. Future didactic perspectives and applications to minimally invasive or virtual reality-assisted therapy seem promising, even though actual clinical applications require further studies.