جستجوی مقالات مرتبط با کلیدواژه "capillary electrophoresis" در نشریات گروه "پزشکی"

The possible adverse effect of histamine on human health has made it a detrimental aspect to the quality and safety of many fermented food products especially fish sauce.

In the present study, hdcA gene in Staphylococcus epidermidis TYH1 was knocked out and its effect on histamine production was evaluated. HdcA encodes histidine decarboxylase, an enzyme that produces histamine from histidine. Both strains of TYH1, the wild type (WT) and mutant (∆hdcA) were then incubated in tryptic soy broth (TSB) supplemented with histidine (0.5 mM). The histamine content determined by capillary zone electrophoretic (CZE) analysis. Safety assessment of this mutant of food origin was conferred by virulence genes.

It was found that S. epidermidis TYH1 exhibited production of histamine (50.09 ± 0.06 μg/mL), while ∆hdcA strain of TYH1 exhibited no histamine forming activity. Safety assessment of ∆hdcA revealed the presence of nuc gene, while superantigenic toxins and coa genes were not observed. Therefore, it has the ability to be used as a starter culture to decrease the histamine content in any fermented food products.

Our study findings may contribute to provide a novel approach of promoting the food safety of fish sauce and other fermented food products regarding the regulation of histamine content.

Determination of HbA1c level is a precious indicator for therapeutic follow-up of patients with type 1 or type 2 diabetes. Our study aimed to evaluate the analytical characteristics of Capillarys 3 Octa® HbA1c measurement by capillary electrophoresis.

Our study involved 265 venous whole blood specimens repeatability, intermediate fidelity, accuracy, linearity, and correlation with the Arkray HA-8180 analyzer which uses HPLC as a dosing method. We studied interferences such as hematocrit, triglycerides, total bilirubin, labile fraction, and hemoglobin abnormalities.

The linearity correlation was between 4.4% and 20.3%. There was a strong correlation with HPLC (r > 0.99, P< 0.0001). No interference from hematocrit (20-93%) (P: 0.888), triglycerides (until 25 mmol/L) (P: 0.388), total bilirubin (< 587 µmol/L) (P: 0.993), and labile fraction was observed. No problem related to inter-sample contamination was observed. The sensitivity was zero for homozygous sickle cell disease and S/C composite hemoglobinosis. However, sensitivity was high for heterozygous forms (69% for A/S and 60% for A/C). The analyzer was able to separate and quantify HbA2 fraction, allowing ß-thalassemia accidental detection.

Capillarys 3 Octa® based on capillary electrophoresis proved to be precise and a linear instrument for HbA1c measurement. Several clinical interferences and Hb variants had no effect on the results. The results of this evaluation suggest that this analyzer is suitable for routine use in clinical chemistry laboratories.

A new microfluidic-based method with electrochemical detection was developed for the simultaneous quantification of acetaminophen (AP) and phenylephrine (PHE) pharmaceuticals in the human blood and pharmaceuticals (e.g. tablet and drop).

The separation was achieved on a SU8/glass microchip with a 100 µm Pt working electrode that was positioned out of the channel and 2-(N-morpholino) ethanesulfonic acid was used as a running buffer (pH 7, 10 mM). Home designed modulated high voltage power supply and dual time switcher was used for controlling the injection and separation of the analytes in the unpinched injection mode.

The injection was carried out using +750 V for 7 seconds, and the separation and detection voltages were set at +1000 V and +0.9 V, respectively. Critical parameters such as detection potential, buffer concentration, injection, and separation voltage were studied in terms of their effects on the resolution, peak height, and migration times. For each analyte, the correlation coefficients were over 0.99 (n=6). The developed microchip was able to detect AP and phenylephrine simultaneously with the limit of detection of 7.9 and 5.2 (µg/mL) respectively for PHE and AP and excellent linear range of 10-200 (µg/mL). The recovery of the drugs ranged from 96% to 103%, while the repeatability of the method through inter- and intra-day was lower than 7%.

The developed method offers several advantages, including easy sample pretreatment process, simplicity, very fast analysis compared to other typical chromatographic methods. Thus, the proposed microfluidic-based method is proposed to be used as a time- and cost-effective monitoring method for the analysis of AP and PHE.

Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide and are usually multifactorial medical conditions. Usually cardiovascular patients must follow a complicated treatment scheme, containing several drugs. Fixed dose combinations (FDCs) are pharmaceutical formulations containing two or more active ingredients in a one pill. FDCs can add multiple benefits to the treatment of CVDs including increased patient compliance, elimination of some side effects and the simultaneous blockage of multiple pathogenic links. The great prevelance of FDCs in modern therapy brings the necessity of developing new analytical methods for the simultaneous analysis of their components. Capillary electrophoresis (CE) was shown to be as a complementary and attractive alternative to the more frequently used chromatographic methods. CE advantages relate to the high efficiency of separation, rapid method developement, short analysis time and relatively low operational costs. The most frequently used CE techniques in the analysis of FDCs are capilllary zone electrophoresis (CZE) for ionized analytes and micellar electrokinetic chromatography (MEKC) for neutral ones. The current article reviews application of CE in the analysis of FDCs used in the treatment of CVDs.

There are more than 400 different variations on α-globin protein, and most of them are not associated with noticeable clinical manifestation. Hemoglobin (Hb) is an oxygen-transporting protein and Hb Daneshgah- Tehran is an α-globin variant that for the first time was reported from Iran in a case with normal haematological indices. The capillary electrophoresis of an 8-year- old-girl with normal hematological parameters showed a peak in the location of Hb S (19.2%) with small amount of Hb A2 variant. The sequencing analysis indicated that the patient was heterozygote for Hb Daneshgah- Tehran (HBA1:c.218A>G p.His72Arg). Alpha and beta thalassemia are common health problems in north of Iran, and about 15% of Mazandarani people are carriers for alpha globin gene deletions, hence premarital screening program can help diagnosis of common and rare hemoglobinopathies. This case was the first report on Hb Daneshgah- Tehran from Mazandaran and the second one from Iran. The presented case showed that Hb Daneshgah- Tehran had haematological indices in normal range, and for the detection of this Hb variant, electrophoresis and PCR sequencing methods should be applied.

Tramadol is a widely used opioid analgesic frequently prescribed for treatment of moderate to severe, acute and chronic pain. It has a complex mechanism of action, acting both as a central opiate agonist and as a norepinephrine and serotonin reuptake inhibitor. It is a chiral substance, having two chiral centers in its structure and it is used in therapy as a racemic mixture of two of its enantiomers, (S,S)-tramadol and (R,R)-tramadol. In the last 25 years, several analytical procedures have been published in the literature for the achiral and chiral determination of tramadol from pharmaceutical formulations and biological matrices. Among these methods, capillary electrophoresis techniques have proved to be an efficient, reliable and cost-effective solution. The purpose of the present review is to provide a systematic survey to present and discuss the electrodriven methods available in the literature for the achiral and chiral analysis of tramadol.

 Non syndromic oculocutaneous albinism type (OCA) is caused by mutations in tyrosinase (TYR), OCA2, TYRP1, MATP (SLC45A2), SLC24A5 and C10ORF11 genes. Screening for mutations is important in families with oculocutaneous albinism patients in order to accurately diagnose the albinism type, genetic counseling and future therapeutic purposes.

 The Aim of this study was to investigate the founder effect of most frequent mutations in OCA patients.

 TYR gene was sequenced in 26 unrelated inbred OCA families as well as 56 unrelated healthy individuals. In addition, homozygosity mapping was performed using 13 STR markers for 6 OCA loci (TYR, OCA2, TYRP1, MATP (SLC45A2), SLC24A5 and C10ORF11 genes). Different mutations were found in these genes from which a single base duplication (c.286dupA) and two single base substitutions c.996G > A (p.M332I) and c.230G > A (p.R77Q) had the most frequencies among the OCA families. In order to investigate the founder effect of these mutations, the haplotypes of two STR markers (TYR-S1 and TYR-S2) inside the TYR gene were ascertained.

 It was revealed that families with similar mutation harbored similar haplotype for the TYR STR markers too.

 We conclude that these mutations are possible founder mutations in the Iranian population.