Cell-Based Imaging Assay for Detection of Phospholipidosis.

Accumulation of lysosomal phospholipids in cells exposed to cationic amphiphilic drugs is characteristic of drug-induced phospholipidosis. The morphological hallmark of phospholipidosis is the appearance of unicentric or multicentric-lamellar bodies when viewed under an electron microscope (EM). The EM method, the gold standard of detecting cellular phospholipidosis, has downsides, namely, low-throughput, high-costs, and unsuitability for screening a large chemical library. This chapter describes a cell-based high-content phospholipidosis assay using the LipidTOX reagent in a high-throughput screening (HTS) platform. This assay has been optimized and validated in HepG2 and HepRG cells, and miniaturized into a 1536-well plate, thus can be used for high-throughput screening (HTS) to identify chemical compounds that induce phospholipidosis.

Estrategia para el diagnóstico de las dislipidemias. Recomendación 2018 / Strategy for the diagnosis of dyslipidaemias

Las dislipidemias son alteraciones del metabolismo lipídico que cursan con concentraciones de lípidos alteradas, tanto por exceso como por defecto. Estas alteraciones están fuertemente asociadas con el proceso aterosclerótico, y se ha demostrado que el control de dichas alteraciones consigue disminuir la incidencia de episodios de origen isquémico. Diagnosticar las dislipidemias desde un punto de vista etiológico es muy importante, ya que el riesgo cardiovascular al que predispone cada una de ellas es diferente, dependiendo del tipo de lipoproteína que esté alterada y de su concentración. Por ello es de gran utilidad disponer de algoritmos diagnósticos sencillos que incluyan magnitudes del metabolismo lipídico disponibles en la mayoría de los laboratorios clínicos, con el fin de realizar el diagnóstico inicial del tipo de dislipidemia, en caso de poseer las herramientas diagnósticas adecuadas identificarla y, en caso contrario, disponer de la información apropiada para recomendar la ampliación del estudio en otro centro que disponga de los recursos necesarios para establecer el diagnóstico

Dyslipidaemias are alterations in lipid metabolism that involve an excess, as well as a deficit, in lipid concentrations. These alterations are strongly associated with atherosclerosis, and it has been shown that its control reduces the incidence of episodes of ischaemic origin. Diagnosing dyslipidaemias from an aetiological point of view is very important, since the cardiovascular risk to which each one predisposes is different, and depends on the type of lipoprotein that is altered and its concentration. For this reason, it is very useful to have simple diagnostic algorithms that include the measurements of lipid metabolism that are available in most clinical laboratories in order to make the initial diagnosis of the type of dyslipidaemia. In the case of having the right diagnostic tools, identify it; and if not, to have the appropriate information to recommend the extension of the study in another centre with resources to establish the diagnosis

Exploiting ensemble learning to improve prediction of phospholipidosis inducing potential.

Phospholipidosis is characterized by the presence of excessive accumulation of phospholipids in different tissue types (lungs, liver, eyes, kidneys etc.) caused by cationic amphiphilic drugs. Electron microscopy analysis has revealed the presence of lamellar inclusion bodies as the hallmark of phospholipidosis. Some phospholipidosis causing compounds can cause tissue specific inflammatory/retrogressive changes. Reliable and accurate in silico methods could facilitate early screening of phospholipidosis inducing compounds which can subsequently speed up the pharmaceutical drug discovery pipelines. In the present work, stacking ensembles are implemented for combining a number of different base learners to develop predictive models (a total of 256 trained machine learning models were tested) for phospholipidosis inducing compounds using a wide range of molecular descriptors (ChemMine, JOELib, Open babel and RDK descriptors) and structural alerts as input features. The best model consisting of stacked ensemble of machine learning algorithms with random forest as the second level learner outperformed other base and ensemble learners. JOELib descriptors along with structural alerts performed better than the other types of descriptor sets. The best ensemble model achieved an overall accuracy of 88.23%, sensitivity of 86.27%, specificity of 90.20%, mcc of 0.765, auc of 0.896 with 88.21 g-means. To assess the robustness and stability of the best ensemble model, it is further evaluated using stratified 10×10 fold cross validation and holdout testing sets (repeated 10 times) achieving 84.83% mean accuracy with 0.708 mean mcc and 88.46% mean accuracy with 0.771 mean mcc respectively. A comparison of different meta classifiers (Generalized linear regression, Gradient boosting machines, Random forest and Deep learning neural networks) in stacking ensemble revealed that random forest is the better choice for combining multiple classification models.

Lipid-Related Lesions in Quaker Parrots ( Myiopsitta monachus).

The Quaker parrot has been used as a psittacine model to study clinical lipidology and lipid-related disorders. However, while Quaker parrots appear to be anecdotally susceptible to a variety of spontaneous dyslipidemic disorders and lesions caused by excess lipid accumulation, epidemiologic data are lacking. A multicenter retrospective study on 652 pathology submissions (411 necropsies and 243 biopsies) from Quaker parrots was performed by recording the final pathological diagnoses, age, and sex for each bird. The prevalence of lesions associated with lipid metabolism, such as hepatic lipidosis, atherosclerosis, xanthomas, adipose tumors, coelomic steatitis/steatonecrosis, endogenous lipid pneumonia, and acute pancreatic necrosis/pancreatitis, was reported. Multiple logistic regression models were used to characterize the effects of sex and age on these lesions, and the prevalence of hepatic lipidosis and atherosclerosis was compared to those in a random sample of control psittacine birds. The raw prevalence of atherosclerosis and hepatic lipidosis was 5.6% (95% confidence interval [CI], 3.4%-7.8%) and 21.2% (95% CI, 17.2%-25.1%), respectively. While the prevalence of atherosclerosis was similar to other psittacine species, hepatic lipidosis was more common in Quaker parrots. Quaker parrots also showed a unique susceptibility to acute pancreatic necrosis with a prevalence of 12.9% (95% CI, 9.7%-16.1%). Male parrots were found to be more susceptible than females to lipid accumulation lesions ( P = .0024), including atherosclerosis ( P = .018) and hepatic lipidosis ( P < .001). This retrospective study confirms the high susceptibility of Quaker parrots to lipid-related disorders and presents epidemiological data that may be useful to avian clinicians, pathologists, and researchers using Quaker parrots.

An Immunohistochemical Investigation of Renal Phospholipidosis and Toxicity in Rats.

Immunohistochemical staining for the lysosome-associated membrane protein 2 (LAMP-2) has been proposed previously as an alternative to electron microscopy to identify hepatic phospholipidosis. This study used LAMP-2 immunohistochemistry (IHC) to diagnose phospholipidosis in rats exhibiting renal tubular injury. Rats were administered toreforant, a histamine H4 receptor antagonist by oral gavage at a dose of 3, 10, or 100 mg/kg/d for 6 months. Hematoxylin and eosin staining revealed renal tubular epithelial cell vacuolation, hypertrophy, degeneration, and luminal dilation in the 100 mg/kg/d group animals. Renal tubular injury was confirmed using kidney injury marker 1 (KIM-1) IHC. The involvement of phosopholipidosis in the renal injury was investigated by LAMP-2. Adipophilin IHC was included to differentiate phospholipidosis from lipidosis. Increased LAMP-2 staining was observed in the 100 mg/kg/d group animals when compared to vehicle group animals. Lysosome-associated membrane protein-2 staining was most prominent in the outer stripe of the outer medulla where KIM-1 staining was also most prominent. By contrast, adipophilin staining was not increased. Phospholipidosis was also confirmed by electron microscopy. These data support the use of LAMP-2 IHC as a diagnostic tool and suggest an association between phospholipidosis and the renal tubular injury caused by toreforant.

Glomerular Lipidosis in Dogs.

Glomerular lipidosis (GL) is characterized by dilated glomerular capillary loops containing lipid-laden cells (foam cells). Previously, GL was considered to be an incidental finding because affected dogs were typically not azotemic. However, the International Renal Interest Society staging system for canine chronic kidney disease has increased the awareness of other clinical parameters (eg, proteinuria and hypertension) that should be included in the assessment of renal function. As such, the aim of this study was to determine clinical abnormalities and concurrent renal lesions in dogs with GL. GL was identified in renal biopsies from 46 dogs evaluated by the International Veterinary Renal Pathology Service. GL was the sole diagnosis in 5 of 46 cases (11%), all of which were proteinuric. All 5 dogs had at least 1 additional clinicopathologic abnormality consistent with renal disease, including hypertension (4), azotemia (3), and/or hypoalbuminemia (2). The remaining 41 dogs had GL in combination with other glomerular lesions, the most common being focal segmental glomerulosclerosis (16, 35%), lesions consistent with juvenile nephropathy (8, 17%), and glomerular amyloidosis (5, 11%). Overall, dogs with severe GL were younger than were those with mild GL ( P < .001). The percentage of glomeruli affected by GL differed by concurrent diagnoses ( P = .034), with the highest percentage of affected glomeruli in dogs with GL alone or those with concurrent juvenile nephropathy. These findings suggest that GL should be a recognized histologic phenotype of glomerular injury associated with clinical renal dysfunction and/or juvenile nephropathies.

Follicular lipidosis in a dachshund dog.

BACKGROUND: Follicular lipidosis is a rare disease, having only been reported in six Rottweiler dogs. The diagnosis of follicular lipidosis is confirmed by histopathological examination of the affected skin. OBJECTIVE: To report a case of follicular lipidosis in a dachshund dog. ANIMALS: A 13-month-old female dachshund dog, with hypotrichosis on the head and cervical region from 10 months of age. METHODS: Histological examination of skin biopsy specimens. RESULTS: Histological examination revealed basket weave orthokeratosis, ballooning of matrix cells and external root sheath keratinocytes. CLINICAL IMPORTANCE: This case report highlights the importance of including follicular lipidosis among the differential diagnoses of noninflammatory and nonhormonal cutaneous lesions in dachshund presented with hair loss.

Biomarker discovery for drug-induced phospholipidosis: phenylacetylglycine to hippuric acid ratio in urine and plasma as potential markers.

CONTEXT: Drug-induced phospholipidosis is one of the significant concerns in drug development, especially in safety assessment and noninvasive diagnostic tool is highly desirable. OBJECTIVE: The objective of this study is to explored novel biomarkers for phospholipidosis using a metabolomic approach. METHOD: NMR spectrometry and LC/MS/MS analyses were applied to urine and plasma of rats administrated cationic amphiphilic drugs. RESULTS: The phenylacetylglycine to hippuric acid ratio in plasma was increased in time and dose-dependent manners; and it was well correlated with histopathological observation. CONCLUSION: The plasma phenylacetylglycine to hippuric acid ratio is a potential marker in monitoring drug-induced phospholipidosis.

[Glomerular lipidosis]. / Lipidosi glomerulari.

Lipidoses occur for an abnormal storage parenchymal deposition of lipids and products of their metabolism in large amounts or sometimes, involving only some particular tissue structures. The lipid storage is usually due to an inborn error causing an enzyme absence /deficiency in the primary lipidoses and to a complex metabolism alterations in the secondary forms. However, histologically all lipid depositions look very similar, and immunohistochemical investigation, clinical pictures knowledge and genetic tests need to make a correct diagnosis. Lipid deposition causes parenchymal structural changes especially of glomeruli resulting in renal function impairment and proteinuria and haematuria appearance. This manuscript gathers clinical and histological features present in these storage pathologies. Renal involvement is described in Anderson-Fabry disease, in hyperlipoproteinemias, in lecithin-cholesterol acyltransferase deficiency, in Gaucher disease and finally in secondary lipidoses features such as nephrotic syndrome, Alagille disease, and toxic or ischemic renal damage. Recently the replacement enzymatic therapy availability is substantially modifying the clinical picture and the outcome in some lipidoses such as Anderson-Fabry and Gaucher diseases. Therefore, it is import to be aware of these disorders, not only for making a correct diagnosis but also for starting, when it is possible, an effective therapy.

Diagnosis and management of lipoedema in the community.

Lipoedema is a chronic progressive adipose disorder that affects mainly women and presents as symmetrical enlargement of the buttocks and legs. It is commonly misdiagnosed as obesity or lymphoedema, but careful assessment will reveal a disproportionate enlargement below the waist which is resistant to dieting, sparing of the feet, legs are tender or painful to touch and bruise easily, there is occasional orthostatic oedema, and there is often significant psychological morbidity. Lipoedema is a oestrogen-regulated condition with onset around puberty in 78% of women, and there is often a strong family history. The condition is exacerbated by weight gain and there is increasing anecdotal evidence that women who are obese are seeking a diagnosis of lipoedema, either to procure NHS funded manual lymphatic drainage, or to medicalise their obesity and avoid acknowledging that the responsibility for their weight gain is lifestyle orientated. Management of lipoedema consists of accurate diagnosis, psychological care, management of orthostatic oedema, and prevention of progression through skin care and weight management.

The Application of Paraphenylenediamine Staining for Assessment of Phospholipidosis.

Drug-induced phospholipidosis is characterized by intracellular accumulation of phospholipids with lamellar bodies in cells exposed to xenobiotics. Demonstration of the lamellar bodies by transmission electron microscopy (TEM) is the hallmark for a definitive diagnosis of phospholipidosis. However, the preparation of tissue samples for TEM and their ultrastructural evaluation are technically challenging and time consuming. Paraphenylenediamine (PPD) is essentially a fat stain, and the staining mechanism is based upon the osmication of unsaturated lipids. Thus, the application of PPD staining to osmicated tissue samples is considered an optimal way to identify lipids. We evaluated the potential of PPD staining to localize phospholipid accumulations on osmium-fixed semi-thin tissue sections of the lung, kidney, and liver, which were affected with phospholipidosis, under a light microscope. PPD staining revealed the presence of PPD positive dark fine granular material in the cytoplasm for all affected tissues examined, which correlated ultrastructurally with lamellar bodies as well as a light microscopic finding of cytoplasmic vacuolation. The great advantage of PPD is that it can be incorporated into the protocol for standard TEM tissue preparation and significantly improve the efficiency of TEM work. In conclusion, PPD provides a simple, sensitive, and reliable method for visualizing phospholipid accumulation on light microscopy and represents an easy tool to study drug-induced phospholipidosis.

Establishment of an in silico phospholipidosis prediction method using descriptors related to molecular interactions causing phospholipid-compound complex formation.

Although phospholipidosis (PLD) often affects drug development, there is no convenient in vitro or in vivo test system for PLD detection. In this study, we developed an in silico PLD prediction method based on the PLD-inducing mechanism. We focused on phospholipid (PL)-compound complex formation, which inhibits PL degradation by phospholipase. Thus, we used some molecular interactions, such as electrostatic interactions, hydrophobic interactions, and intermolecular forces, between PL and compounds as descriptors. First, we performed descriptor screening for intermolecular force and then developed a new in silico PLD prediction using descriptors related to molecular interactions. Based on the screening, we identified molecular refraction (MR) as a descriptor of intermolecular force. It is known that ClogP and most-basic pKa can be used for PLD prediction. Thereby, we developed an in silico prediction method using ClogP, most-basic pKa, and MR, which were related to hydrophobic interactions, electrostatic interactions, and intermolecular forces. In addition, a resampling method was used to determine the cut-off values for each descriptor. We obtained good results for 77 compounds as follows: sensitivity = 95.8%, specificity = 75.9%, and concordance = 88.3%. Although there is a concern regarding false-negative compounds for pKa calculations, this predictive ability will be adequate for PLD screening. In conclusion, the mechanism-based in silico PLD prediction method provided good prediction ability, and this method will be useful for evaluating the potential of drugs to cause PLD, particularly in the early stage of drug development, because this method only requires knowledge of the chemical structure.

[Lysosomal storage diseases: A brief summary]. / Lysosomale Speicherkrankheiten : Ein kurzer Abriss.

BACKGROUND: A considerable number of lysosomal storage diseases (LSD), which can occur at any age in life, should be included in the differential diagnosis of histiocytic diseases. OBJECTIVE: To what extent can pathologists contribute to the diagnostics of LSD? MATERIAL AND METHODS: In material collected from LSD, morphological storage phenomena in some disease forms, particularly in histiocytic cells from bone marrow smears and some tissues are highlighted, presented and described. Due to the multitude and heterogeneity of LSDs this list is by no means exhaustive. RESULTS: In Gaucher disease, the forms of Niemann-Pick disease, cholesteryl ester storage disease (CESD), GM1 gangliosidosis and other LSDs, the histiocytic storage cells seen, for example, in bone marrow smears can be finely and ultrastructurally differentiated. Thereby, not only the presence of an LSD in general but also some individual types of LSD can be identified, even though preliminarily. To confirm the diagnosis the genetic and sometimes biochemical analysis of blood samples or fibroblast cultures from patients is usually required. CONCLUSION: The pathologist may be the first to suspect LSD and this applies to LSDs that show storage histiocytes or one of a number of other LSDs in which only minor or absent storage is seen in histiocytes but marked storage phenomena are found in other cell systems. Some of the numerous, extremely heterogeneous LSDs may, however, be overlooked as detailed knowledge of the generally rare LSDs is the domain of LSD specialists. Clinicians, pathologists, geneticists and biochemists should cooperate in solving the diagnostic problems.

Early lipoedema diagnosis and the RCGP e-learning course.

Frequently misdiagnosed as obesity, lipoedema is chronic condition involving an abnormal build-up of fat cells in the legs, thighs and buttocks that cannot be shifted by exercise or dieting. Estimated to affect up to 11% of the female population, the condition is widely unknown by health professionals. This means women typically wait for many years before diagnosis. This allows the condition to progress unchecked, resulting in unnecessary deterioration and the development of associated comorbidities, as well as significant pain and mental anguish. A free, 30-minute Royal College of General Practitioners (RCGP) e-learning course created in partnership with Lipoedema UK aims to rectify this situation by educating nurses, GPs and other health professionals on how to diagnose and manage lipoedema in primary care. This article aims to describe the condition of lipoedema, how to recognise/diagnose it, current treatment options and the findings of a 240-patient survey carried out by Lipoedema UK in 2013 that included documenting the difficulties for patients in obtaining a diagnosis as well as the mental and physical effects of the condition.

A diagnostic approach to recurrent myalgia and rhabdomyolysis in children.

Episodic myalgia is a common complaint in children and young adults. While many cases remain idiopathic even after extensive investigation, myalgia can be the first symptom of an underlying serious neuromuscular condition, and can be associated with an increased risk of such serious complications as rhabdomyolysis and malignant hyperthermia. We review and highlight the metabolic myopathies and other increasingly recognised muscle disorders that may present to paediatricians with episodic myalgia or isolated episodes of rhabdomyolysis, and propose a diagnostic algorithm for investigation of these complaints.

Liposome electrokinetic chromatography based in vitro model for early screening of the drug-induced phospholipidosis risk.

Drug-induced phospholipidosis (PLD) is a storage disorder of lysosomes characterized by the excessive accumulation of phospholipids as a result of improper medical treatments. Although few evidences have supported that PLD can induce significant pathological consequences, this potential toxicity indeed can put off the drug discovery process. In this research, a high-throughput liposome electrokinetic chromatography (LEKC) method was validated to evaluate the PLD risk of drug candidates by screening drug-phospholipid interaction, which correlates to the phospholipidosis inducing risk. A statistical analysis based on the Spearman's correlation test showed that the retention factors (log k) of the tested drugs in the LEKC system and the literature reported in vivo and in vitro PLD data were highly correlated. In order to investigate the predictability of LEKC, the effect of liposome composition such as the molar ratio of phospholipids and the addition of cholesterol were also discussed in this study. The results indicated that the LEKC method could offer a fast, reliable and cost-effective screening tool for early prediction of the PLD inducing potential of drug candidates.

Renal lipidosis in patients enrolled in a methadone substitution program.

Kidney biopsies often show accumulation of lipids or lipidlike material. Evidence has been provided that lipids can directly initiate and contribute to the progression of glomerular and tubulointerstitial lesions. In this study we describe a renal lipidosis occurring in patients with a positive history of narcotic abuse who were enrolled in a methadone substitution program. All 3 patients presented with proteinuria (2.5-20 g/d) and impaired renal function. Renal biopsy revealed a pronounced extracellular and intracellular deposition of lipidlike material in the glomerular, interstitial, and tubular compartments. Known causes of lipid storage could be excluded clinically and morphologically. We consider this to be a distinct renal lipidosis associated with narcotic abuse, methadone intake, or intravenous abuse thereof.