Methods for the Determination of the Purity of Exosomes

2020 ◽  
Vol 25 (42) ◽  
pp. 4464-4485 ◽  
Author(s):  
Katarzyna Kluszczyńska ◽  
Liliana Czernek ◽  
Wojciech Cypryk ◽  
Łukasz Pęczek ◽  
Markus Düchler
Keyword(s):  
Drug Transport ◽  
Biological Fluids ◽  
Drug Carriers ◽  
Biological Functions ◽  
Isolation And Purification ◽  
Pubmed Database ◽  
High Concentrations ◽  
Targeted Release

Background: Exosomes open exciting new opportunities for advanced drug transport and targeted release. Furthermore, exosomes may be used for vaccination, immunosuppression or wound healing. To fully utilize their potential as drug carriers or immune-modulatory agents, the optimal purity of exosome preparations is of crucial importance. Methods: Articles describing the isolation and purification of exosomes were retrieved from the PubMed database. Results: Exosomes are often separated from biological fluids containing high concentrations of proteins, lipids and other molecules that keep vesicle purification challenging. A great number of purification protocols have been published, however, their outcome is difficult to compare because the assessment of purity has not been standardized. In this review, we first give an overview of the generation and composition of exosomes, as well as their multifaceted biological functions that stimulated various medical applications. Finally, we describe various methods that have been used to purify small vesicles and to assess the purity of exosome preparations and critically compare the quality of these evaluation protocols. Conclusion: Combinations of various techniques have to be applied to reach the required purity and quality control of exosome preparations.

Analytical Methods for the Determination of Sartans in Pharmaceutical Formulations and Biological Fluids: A Review

2020 ◽  
Vol 16 (3) ◽  
pp. 208-222
Author(s):  
Miglena Smerikarova ◽  
Stanislav Bozhanov ◽  
Vania Maslarska
Keyword(s):  
Biological Fluids ◽  
Pharmaceutical Preparations ◽  
Improve Patient Care ◽  
Pharmaceutical Formulations ◽  
Treatment Of Hypertension ◽  
Therapeutic Doses ◽  
Reliable Methods ◽  
Improve Patient

Background: Sartans are mostly used as a part of combination with additional medicines in the therapy of essencial hypertension. Preferred combinations are ARB and thiazide diuretics (Hydrochlorothiazide (HCT) and Chlorthalidone (CHL)) or ARB and calcium antagonists. The number of sartans mostly prescribed by specialists is only seven - Candesartan (CDS), Eprosartan (EPS), Irbesartan (IBS), Losartan (LOS), Olmesartan (OMS), Telmisartan (TMS) and Valsartan (VLS). Methods: The widespread use of sartans in the treatment of hypertension requires reliable methods of analysis. Bulk drugs and pharmaceutical preparations should be analyzed to ensure the quality of the medicinal products reaching patients. On the other hand, the analysis of drugs in biological fluids aims to trace and improve patient care by adjusting the therapeutic doses of drugs. According to our knowledge, a review devoted to the analysis of sartans was published in 2014. Results: Spectral methods are widely used in the analysis of bulk drugs and pharmaceutical dosage forms due to their relatively simple procedures, low reagent and sample consumption, speed, precision and accuracy combined with accessibility and comparatively low cost of common apparatus. Many papers for determination of sartans in bulk drugs and pharmaceutical preparations based on liquid chromatographic techniques were published in the available literature. Among these methods, HPLC takes the leading place but UPLC and HPTLC are also present. Conclusion: The widespread use of sartans in the treatment of hypertension requires reliable methods of analysis. Bulk drugs and pharmaceutical preparations should be analyzed to ensure the quality of the medicinal products reaching patients. On the other hand, the analysis of drugs in biological fluids aims to trace and improve patient care by adjusting the therapeutic doses of drugs. Since 2014, many articles have been published on the sartans analysis and this provoked our interest to summarize the latest applications in the analysis of sartans in pharmaceutical formulations and biological media. Articles published from 2014 to 2018 are covered.

scholarly journals Effects of Macronutrients in the Physiological Quality of Soybean Seeds

2018 ◽  
Vol 10 (5) ◽  
pp. 312
Author(s):  
Geliandro Anhaia Rigo ◽  
Luis Osmar Braga Schuch ◽  
Willian Silva Barros ◽  
Rodrigo Lamaison de Vargas ◽  
Vinícius Jardel Szareski ◽  
...  
Keyword(s):  
Graduate Program ◽  
Plant Tissues ◽  
Soybean Seeds ◽  
Rio Grande Do Sul ◽  
Genetic Characteristics ◽  
Physiological Quality ◽  
High Concentrations ◽  
Nitrogen Phosphorus

The aim of this work was to correlate macronutrient content of soybean seeds to physiological quality of different cultivars. The work was developed in the Federal University of Pelotas, in the facilities of the Seed Science and Technology Graduate Program. The experimental design was randomized blocks in arranged in four replicates. The following soybean cultivars were used: BMX Apolo RR (12 lots), BMX Ativa RR (13 lots), BMX Energia RR (26 lots), BMX Força RR (24 lots), BMX Impacto RR (35 lots), BMX Magna RR (16 lots), BMX Turbo RR (44 lots), BMX Potência RR (82 lots) and NA 5909 RR (28 lots), with seeds produced in northwest Rio Grande do Sul. The determination of nutritional contents found in plant tissues of soybean seeds, were measured: Nitrogen (N), Phosphorus (P), Potassium (K), Magnesium (Mg), Calcium (Ca), Sulfur (S). The macronutrient contents of the seeds vary according to genetic characteristics of the cultivars, with higher oscillations of nitrogen, phosphorus, magnesium and sulfur contents present in soybean seeds. Potassium and calcium are defined as the most stable nutrients for the cultivars and seed lots analyzed. High concentrations of nitrogen, phosphorus and calcium are determinants for the physiological quality of soybean seeds.

Biochemical markers in the prediction of contrast-induced acute kidney injury

2020 ◽  
Vol 27 ◽  
Author(s):  
Magdalena Zdziechowska ◽  
Anna Gluba-Brzózka ◽  
Beata Franczyk ◽  
Jacek Rysz
Keyword(s):  
Acute Kidney Injury ◽  
Kidney Injury ◽  
Coronary Intervention ◽  
Percutaneous Coronary ◽  
High Concentrations ◽  
Kidney Injury Molecule 1 ◽  
Neutrophil Gelatinase ◽  
Overall Mortality

: For many years clinicians have been searching for “kidney troponin”- a simple diagnostic tool to assess risk of acute kidney injury (AKI). Recently, the rise in the variety of contrast-related procedures (contrast computed tomography [CT], percutaneous coronary intervention [PCI] and angiography) have resulted in increased number of contrast-induced acute kidney injuries (CI-AKI). CI-AKI remains important cause of overall mortality, prolonged hospitalization and it increases total costs of therapy. The consequences of kidney dysfunction affect the quality of life and they may lead to disability as well. Despite extensive worldwide research, there are no sensitive and reliable method of CI-AKI prediction. Kidney Injury Molecule 1 (KIM-1) and Neutrophil Gelatinase Lipocalin (NGAL) have been considered as kidney specific molecules. High concentrations of these substances before the implementation contrast-related procedures have been suggested to enable the estimation of kidney vulnerability to CI-AKI and they seem to have predictive potential for cardiovascular events and overall mortality. According to other authors, routine determination of known inflammation factors (e.g. CRP, WBC, neutrophil count) may be helpful in prediction of CI-AKI. However, the results of clinical trials provide contrasting results. The pathomechanism of contrast-induced nephropathy remains unclear. Due to its prevalence, the evaluation of the risk of acute kidney injury remains serious problem to be solved. This paper reviews pathophysiology and suggested optimal markers facilitating the prediction of contrast-induced acute kidney injury.

A METHOD FOR THE SIMULTANEOUS DETERMINATION OF PROGESTERONE, ANDROSTENEDIONE, TESTOSTERONE AND DEHYDROEPIANDROSTERONE SULPHATE IN BIOLOGICAL FLUIDS

1968 ◽  
Vol 57 (3) ◽  
pp. 447-456 ◽  
Author(s):  
Asbjørn Aakvaag ◽  
Petter Fylling
Keyword(s):  
Simultaneous Determination ◽  
Biological Fluids ◽  
List Type ◽  
Human Ovary ◽  
Peripheral Plasma ◽  
High Concentrations ◽  
Venous Plasma ◽  
Ovarian Cyst Fluid

ABSTRACT A method is presented for the simultaneous determination of progesterone, androstenedione, testosterone and dehydroepiandrosterone sulphate in biological fluids. The method has been applied for the investigation of the secretion of these compounds by the ovary as well as their concentration in ovarian cyst fluid and peripheral plasma. The concentrations of the three androgens were all found to be higher in ovarian venous plasma than in peripheral plasma, and are thus shown to be secreted by the human ovary. High concentrations of progesterone were found in the ovarian vein blood when a corpus luteum was present. In some cases progesterone was also found to be secreted by the ovary during the follicular phase. The data are discussed and found to be in agreement with the suggestion that progesterone and androgens are secreted by different anatomical compartments of the human ovary in vivo.

XII.—The Quality of the Forth Estuary (2)

1972 ◽  
Vol 71 (2-4) ◽  
pp. 143-170 ◽  
Author(s):  
R.W. Covill
Keyword(s):  
Biological Data ◽  
Dissolved Oxygen Concentration ◽  
Sources Of Pollution ◽  
Present Information ◽  
Time Work ◽  
Legal Position ◽  
Inshore Waters ◽  
High Concentrations

SynopsisThe introduction indicates the legal position relative to the control of discharges to the Forth estuary. Details are given of the volumes of the known sources of pollution, in 1958; chemical, bacteriological and biological data then follow relative to a survey carried out in August and September of that year. The conclusions, drawn from the 1958 Survey, emphasised the gross pollution existing at that time, and suggested methods whereby the pollution might be reduced. Section 4 of the paper discusses the results of chemical, biological, bacteriological and hydrographical surveys carried out since 1962. The results stress the deterioration in conditions in the estuary compared with the earlier survey, and in particular, the lower dissolved oxygen concentration in inshore waters and the increase in the Coliform and Escherichia coli counts in certain areas. Isolation of Salmonella species implies the possible health hazards existing at the present time. Work so far carried out in respect of the determination of heavy metal concentrations in core samples taken in the intertidal zone along the shore has indicated relatively high concentrations of certain metals and their effect on the ecology of the estuary has yet to be fully assessed. Float tests made over a period emphasise the tendency for the sewage discharges to be confined to inshore waters, resulting in the gross pollution of certain beaches. Present information stresses the need for the continuance of the monitoring programme.

scholarly journals Childhood and adolescent obesity and adult mortality: a systematic review of cohort studies

2008 ◽  
Vol 24 (suppl 4) ◽  
pp. s558-s568 ◽  
Author(s):  
Fernando Adami ◽  
Francisco de Assis Guedes de Vasconcelos
Keyword(s):  
Systematic Review ◽  
Cohort Studies ◽  
Adult Mortality ◽  
Adolescent Obesity ◽  
Childhood And Adolescence ◽  
Pubmed Database ◽  
Childhood And Adolescent Obesity ◽  
The Relationship

This systematic review addressed cohort studies on obesity in childhood and adolescence and adult mortality, published from January 1990 to March 2007. We searched the PubMed database with the following uniterms: obesity, mortality, child, adolescent; obesity and mortality; overweight and mortality. References were also analyzed. The age limit was 2 to 18 years. Quality of the articles was assessed, and eight were identified and reviewed. All used weight and stature for determination of obesity, and seven used body mass index (BMI). The quality score varied from 9 to 17. Evidence of association between obesity in childhood and adolescence and adult mortality should be viewed with caution. Use of BMI and potential confounders were discussed. Further research is needed to analyze the relationship between childhood and adolescent obesity and adult mortality.

Measurement of tricyclic antidepressants. Part II. Applications of methodology.

1980 ◽  
Vol 26 (7) ◽  
pp. 805-815 ◽  
Author(s):  
B A Scoggins ◽  
K P Maguire ◽  
T R Norman ◽  
G D Burrows
Keyword(s):  
Tricyclic Antidepressants ◽  
Biological Fluids ◽  
Plasma Concentrations ◽  
New Drugs ◽  
Rigorous Evaluation ◽  
Method Of Measurement ◽  
Precise Relationship ◽  
New Generation

Abstract This review, together with Part 1 (Clin. Chem. 26: 5-17, 1980), summarizes progress in measurement of tricyclic antidepressants in biological fluids and the application of the methodology to clinical practice. For many of the older drugs and for all of the new-generation antidepressants, further studies are required to delineate the precise relationship between plasma concentration and clinical response in well-defined diagnostic groups. For new drugs, rigorous evaluation of a method of measurement is required before it is applied to clinical studies. Assessment of drug interactions, inter-patient variability in plasma concentrations, and determination of the plasma concentrations required for therapeutic response all depend almost entirely on the quality of the assay methodology.

Measurement of tricyclic antidepressants. Part II. Applications of methodology.

1980 ◽  
Vol 26 (7) ◽  
pp. 805-815 ◽  
Author(s):  
B A Scoggins ◽  
K P Maguire ◽  
T R Norman ◽  
G D Burrows
Keyword(s):  
Tricyclic Antidepressants ◽  
Biological Fluids ◽  
Plasma Concentrations ◽  
New Drugs ◽  
Rigorous Evaluation ◽  
Method Of Measurement ◽  
Precise Relationship ◽  
New Generation

Abstract This review, together with Part 1 (Clin. Chem. 26: 5-17, 1980), summarizes progress in measurement of tricyclic antidepressants in biological fluids and the application of the methodology to clinical practice. For many of the older drugs and for all of the new-generation antidepressants, further studies are required to delineate the precise relationship between plasma concentration and clinical response in well-defined diagnostic groups. For new drugs, rigorous evaluation of a method of measurement is required before it is applied to clinical studies. Assessment of drug interactions, inter-patient variability in plasma concentrations, and determination of the plasma concentrations required for therapeutic response all depend almost entirely on the quality of the assay methodology.

Variations in the distribution of okadaic acid in organs and biological fluids of mice related to diarrhoeic syndrome

1999 ◽  
Vol 18 (5) ◽  
pp. 345-350 ◽  
Author(s):  
W G Matias ◽  
A Traore ◽  
E E Creppy
Keyword(s):  
Okadaic Acid ◽  
Potent Inhibitor ◽  
Enterohepatic Circulation ◽  
Biological Fluids ◽  
Intestinal Content ◽  
Fluorescent Detection ◽  
Shellfish Poisoning ◽  
Intestinal Tissue ◽  
High Concentrations

Okadaic acid (OA) is the main toxin produced by dinoflagellates which can accumulate in the hepatopancreas of mussels and cause diarrhetic shellfish poisoning in consumers. This toxin is also a tumour promoter and a specific potent inhibitor of protein phosphatases 1 and 2A. No specific target organ is known for this toxin. This study concerns the distribution of [3H]OA in organs and biological fluids of Swiss mice having received a single dose per os of AO (50 mg/kg). The determination of the toxin extracted from mouse organs 24 h after administration of [3H]OA and derivatised with 9-anthryldiazo methane (ADAM) before HPLC and fluorescent detection showed the highest concentration in intestinal tissue and stomach. This distribution was even more pronounced in intestinal tissue, when animal were given per os 90 mg/kg which induced diarrhoea. The high concentrations of [3H]OA in intestinal tissues and contents 24 h after administration demonstrates a slow elimination of OA. When the dose of OA was increased from 50–90 mg/kg, the concentrations of the toxin in the intestinal content and faeces increased proportionally. A good correlation was found between an increase of OA in the intestinal tissue and the diarrhoea in animals given 90 mg/kg orally. Moreover OA was present in liver and bile and in all organs including skin and also fluids. Altogether these results confirmed an enterohepatic circulation of OA as previously shown. These data also revealed that in acute OA intoxication the concentration of the toxin in the intestinal tissues reaches cytotoxic concentrations in accordance with the diarrhoea which is the main symptom of OA poisoning.

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