Correlation of hepatic copper levels, rhodanine scores and histological diagnosis in archived canine liver samples.

The liver is the main storage site for copper. Excess copper accumulation, however, is a risk factor for the development of chronic hepatitis in dogs. Mass spectrometry or rhodanine staining are frequently used methods to assess copper levels in the liver. The association was studied between analytic hepatic copper levels and rhodanine scores in archived canine formalin-fixed-paraffinembedded liver sections from 2014 to 2021 with various diagnoses. Thirty-six (N = 36) liver samples with analytic interpretation of toxic (n = 12), high normal (n = 17), and normal (n = 7) copper levels were selected for the study. Rhodanine staining for each of these samples was graded (scale: 1 to 5), and the association was determined between actual liver copper levels and rhodanine scores and histological diagnoses (chronic hepatitis or other diagnoses). The analytic copper level and rhodanine scores were significantly higher (P < 0.05) in samples designated as toxic compared to normal. There was a significant association between hepatic copper levels and rhodanine scores (P < 0.05). Rhodanine score, but not the actual liver copper levels were significantly (P < 0.05) associated with chronic hepatitis versus other diagnoses. Rhodanine scores of ≥ 1.89 were statistically significant predictors of chronic hepatitis. It was concluded from this study that actual liver copper levels are positively associated with rhodanine scores and rhodanine scores can be a useful predictor of chronic hepatitis.

Le foie est le principal site de stockage du cuivre. Cependant, une accumulation excessive de cuivre est un facteur de risque pour le développement d'une hépatite chronique chez le chien. La spectrométrie de masse ou la coloration à la rhodanine sont des méthodes fréquemment utilisées pour évaluer les niveaux de cuivre dans le foie. L'association entre les niveaux analytiques de cuivre hépatique et les scores de rhodanine a été étudiée dans des sections de foie de chien archivées fixées au formol et incluses dans de la paraffine de 2014 à 2021 avec divers diagnostics. Trente-six (N = 36) échantillons de foie avec interprétation analytique des niveaux de cuivre toxiques (n = 12), normaux élevés (n = 17) et normaux (n = 7) ont été sélectionnés pour l'étude. La coloration à la rhodanine de chacun de ces échantillons a été évaluée (échelle : 1 à 5) et l'association a été déterminée entre les niveaux réels de cuivre dans le foie et les scores de rhodanine et les diagnostics histologiques (hépatite chronique ou autres diagnostics). Les niveaux analytiques de cuivre et les scores de rhodanine étaient significativement plus élevés (P < 0,05) dans les échantillons désignés comme toxiques par rapport à la normale. Il y avait une association significative entre les niveaux de cuivre hépatique et les scores de rhodamine (P < 0,05). Le score de rhodanine, mais pas les niveaux réels de cuivre dans le foie, était significativement (P < 0,05) associé à l'hépatite chronique par rapport à d'autres diagnostics. Les scores de rhodanine ≥ 1,89 étaient des prédicteurs statistiquement significatifs de l'hépatite chronique. Il a été conclu à partir de cette étude que les niveaux réels de cuivre dans le foie sont positivement associés aux scores de rhodanine et que les scores de rhodanine peuvent être un prédicteur utile de l'hépatite chronique.(Traduit par Docteur Serge Messier).

Hepatic copper accumulates in ferrets with and without hepatobiliary disease.

OBJECTIVE: To determine hepatic copper concentrations and zonal distribution in ferrets with and without hepatobiliary disease, validate rhodanine-based qualitative copper scoring and digital copper quantification in ferret hepatic samples, and ascertain whether clinical features predicted copper accumulation. ANIMALS: 34 ferrets, including 7 with necroinflammatory disease, 5 with hepatocellular carcinoma, 13 with non-necroinflammatory disease, and 9 with no hepatobiliary disease. PROCEDURES: Rhodanine-based digital copper quantification was validated by use of liver dually measured by atomic absorption spectroscopy and digital scanning (R2 = 0.98). Clinical features and hepatic copper scores and concentrations (dry weight liver) were compared between groups. Zonal copper distribution was determined. RESULTS: Hepatic copper concentration was strongly correlated with copper scores (ρ = 0.88). Ferrets with hepatobiliary disease were significantly older and had significantly higher serum alkaline phosphatase and γ-glutamyltransferase activities and creatinine concentrations. Centrilobular copper accumulated in 23 of 34 (64%) ferrets with (n = 15) and without (8) hepatobiliary disease. Median copper concentrations were not significantly different between ferrets with and without hepatobiliary disease but were significantly higher within neoplastic hepatic tissue in ferrets with hepatocellular carcinoma. Hepatic copper concentrations exceeded feline (> 180 µg/g) and canine (> 400 µg/g) reference limits in 19 and 9 ferrets, respectively. Hepatic copper > 1,000 µg/g occurred in 5 ferrets with and 2 without hepatobiliary disease. Clinical features did not predict copper accumulation. CLINICAL RELEVANCE: Rhodanine-based digital copper quantification and qualitative copper scoring discerned liver copper accumulation in ferrets. Ferrets with and without hepatobiliary disease displayed a propensity for centrilobular hepatic copper accumulation of uncertain clinical importance. Clinical and clinicopathologic features could not exclusively implicate pathologic copper accumulation.

Fluorogenic Probing of Membrane Protein Trafficking.

Methods to differentially label cell-surface and intracellular membrane proteins are indispensable for understanding their function and the regulation of their trafficking. We present an efficient strategy for the rapid and selective fluorescent labeling of membrane proteins based on the chemical-genetic fluorescent marker FAST (fluorescence-activating and absorption-shifting tag). Cell-surface FAST-tagged proteins could be selectively and rapidly labeled using fluorogenic membrane-impermeant 4-hydroxybenzylidene rhodanine (HBR) analogs. This approach allows the study of protein trafficking at the plasma membrane with various fluorometric techniques, and opens exciting prospects for the high-throughput screening of small molecules able to restore disease-related trafficking defects.

Dispersive liquid-liquid microextraction of lead(II) as 5-(4-dimethylaminobenzylidene) rhodanine chelates from food and water samples.

A dispersive liquid-liquid microextraction procedure for lead(II) as its 5-(4-dimethylaminobenzylidene) rhodanine complex has been established prior to its microsampling flame atomic absorption spectrometric determination. The influences of various analytical parameters including pH, solvent type and volume, dispersive solvent type and volume, 5-(4-dimethylaminobenzylidene) rhodanine amount, salt effect, and centrifugation time and speed were investigated. The effects of certain alkali, alkaline earth, and transition metal ions on the quantitative extraction of lead(II) were also studied. Quantitative recoveries were obtained at pH 6. The enrichment factor was calculated as 125. The detection limit for lead is 1.1 µg/L. The accuracy of the method was tested with the additions recovery test and analysis of the standard reference materials (SPS-WW2 waste water, NIST SRM 1515 apple leaves, and TMDA-51.3 fortified water). Applications of the present procedure were tested by analyzing water and food samples.

Study on the interaction among molecules and the determination of DNA by light scattering with a new type rhodanine derivative.

In this paper the resonance Rayleigh scattering (RRS) and second-order scattering (SOS) spectrums of interaction between deoxyribonucleic acid (DNA) and 3-(4'-methylphenyl)-5-(2'-sulfophenylazo) rhodanine (4MRASP) in the environment of surface active substance sodium dodecyl sulfate (SDS) were reported. The light scattering intensity of 4MRASP was enhanced obviously and directly proportional to the concentrations of DNA when DNA was present. Based on this, two new determination methods of DNA were established with high sensitivity and selectivity, and the limits of detection were 8.00 and 1.07ngmL(-1). They were applied to the determination of trace amounts of nucleic acid in synthetic and practical samples with satisfactory results. At last, the active mechanism among molecules was studied by ultraviolet spectrum, scattering spectrum and thermodynamics, which showed that the active force was changed from hydrophobic force to electrostatic force before and after SDS was added, and the mechanism of sensitization effect of SDS was proposed.

[Study on solid-phase-extraction spectrophotometric determination of silver with p-sulfobenzylidene-rhodanine].

The color reaction of silver with p-sulfobenzylidene-rhodanine (SBDR) was studied. Based on the color reaction of SBDR with silver (I) and the solid phase extraction of its colored complex with Waters Porapak Sep-Park-C18 cartridge, a new method for the determination of micro-amount of silver (I) was studied. In the presence of pH = 2.8 citric acid-sodium hydroxide buffer solution and Tween-80 medium, SBDR can react with silver (I) to form a stable 2:1 complex. The colored complex can be extracted by C18 cartridge and eluted by ethanol (containing 5% acetic acid), and then can be determined by spectrophotometry. The molar absorptivity is 7.53 x 10(4) L x mol(-1) x cm(-1) at 520 nm. Beer's law is obeyed in the range of 0-1.2 microg x (25 mL)(-1). This method can be applied to the determination of silver in water with satisfactory results.