Exchange High Performance Liquid Chromatography Research Articles

Association of Glycated Hemoglobin With Acute Ischemic Stroke in a Tertiary Care Center in a Tribal Region of Jharkhand.

Increased glycated hemoglobin (HbA1c) levels have shown an association with an increased risk of stroke in patients admitted to a tertiary care center in Jharkhand. To find out and estimate the risk of acute ischemic stroke in patients with increased HbA1c levels compared with controls. This observational case-control study was conducted on patients admitted to the department of general medicine at a tertiary care center in Ranchi from June 2021 to November 2022. The patients included in this study were those aged 18 years or older and who were clinically and radiologically diagnosed with acute ischemic stroke. Only patients with a first episode of stroke were included, and patients with hemorrhagic stroke or transient ischemic attack were excluded from this study. An equal number of control participants were also included. Ion exchange high-performance liquid chromatography was used to perform the HbA1c tests. The same method was used to measure HbA1c levels in the controls. All findings were recorded in aMicrosoft Excel sheet (Microsoft Corporation, Redmond, WA), and the data were analyzed using SPSS version 22.0software (IBM Corp., Armonk, NY). After performing a descriptive statistical analysis, the findings were classified over a range of values and described accordingly. For each variable, an independent t-test was performed to compare the cases with the controls. A multivariable logistic regression analysis was used to choose the appropriate potential factors to determine the association in the multivariable analysis. A total of 185 cases and 185 controls were included. The mean age of the cases with ischemic stroke was 63.77 ± 10.312, and that of the controls was 53.18 ± 11.35 (p < 0.01). The mean HbA1c level in the patients of acute ischemic stroke was 6.97 ± 1.84, and that of the controls was 5.99 ± 1.69 (p < 0.01). The mean random blood sugar (RBS) value in the ischemic stroke cases was 170.21 ± 84.16, and that of the controls was 150.03 ± 82.25 (p = 0.02). To compare the factors that were determined to be statistically significant between ischemic stroke cases and controls, a multivariable logistic regression analysis was performed. The HbA1c p-value was 0.01, the odds ratio (OR) was 1.280, and the 95% CI was 1.11-1.48. The other variables apart from HbA1c that were statistically significant between the ischemic stroke cases and the controls were age (p < 0.01, OR: 1.280, 95% CI: 1.06-1.11), hypertension (p = 0.618, OR: 1.130, 95% CI: 0.70-1.83), and high-density lipoprotein (p = 0.055, OR: 0.975, 95% CI: 0.95-1.00). When other cofounders were considered, it was concluded that with a 1% increase in HbA1c, the risk of stroke increases by 28% (OR: 1.28, 95% CI: 1.11-1.48). To compare the variables that were determined to be statistically significant between the control and ischemic stroke case groups, a multivariable logistic regression was used. The area under the receiver operating characteristic curve for HbA1c was 0.773and RBS was 0.600. This study shows that higher HbA1c levels in patients increase the risk of ischemic stroke. This study brings to light the need to screen the population periodically for diabetes by routinely testing for Hba1c in those who are at high risk of diabetes. Stroke risk can be reduced with early management and intervention. This study also concludes that HbA1c is a better predictor for assessing the risk of ischemic stroke than RBS levels.

Arsenic speciation analysis in cow's milk and plant-based imitation milks by HPLC-ICP-MS

Imitation milks based on vegetables have become relevant in recent years as a substitute for cow´s milk. Total and inorganic content of arsenic (As) determination in food is of utmost importance due to toxicological concerns. This study aimed to (1) optimize and validate a methodology for speciation analysis using anion exchange high performance liquid chromatography coupled to plasma mass spectrometry and (2) analyze the arsenic content in milk and imitation milks. Determination of As (III) and As (V) was done following a simple and innovative treatment, which consisted on the dilution of a small volume of sample in mobile phase and further filtration. Furthermore, acid microdigestion for total As determination with small amounts of acid and sample was optimized. The detection limits of the method ranged from 0.2 to 0.7 µg L−1. Regarding to arsenic content we found that imitation milks based on peanuts and nuts presented the lowest inorganic As content (between 1.7 and 1 µg L−1) whereas the highest values were found in imitations based on soy, rice and vetch (27.3, 13 and 8 µg L−1, respectively). The cow’s milk presented intermediate levels of inorganic As (4 µg L−1). Also, almond- and quinoa-based imitation milks showed inorganic As values below detection limits, so these imitation milks may be the safest to consume with respect to arsenic content.

Knockout of the intellectual disability-linked gene Hs6st2 in mice decreases heparan sulfate 6-O-sulfation, impairs dendritic spines of hippocampal neurons, and affects memory.

Heparan sulfate (HS) is a linear polysaccharide that plays a key role in cellular signaling networks. HS functions are regulated by its 6-O-sulfation, which is catalyzed by three HS 6-O-sulfotransferases (HS6STs). Notably, HS6ST2 is mainly expressed in the brain and HS6ST2 mutations are linked to brain disorders, but the underlying mechanisms remain poorly understood. To determine the role of Hs6st2 in the brain, we carried out a series of molecular and behavioral assessments on Hs6st2 knockout mice. We first carried out strong anion exchange-high performance liquid chromatography and found that knockout of Hs6st2 moderately decreases HS 6-O-sulfation levels in the brain. We then assessed body weights and found that Hs6st2 knockout mice exhibit increased body weight, which is associated with abnormal metabolic pathways. We also performed behavioral tests and found that Hs6st2 knockout mice showed memory deficits, which recapitulate patient clinical symptoms. To determine the molecular mechanisms underlying the memory deficits, we used RNA sequencing to examine transcriptomes in two memory-related brain regions, the hippocampus and cerebral cortex. We found that knockout of Hs6st2 impairs transcriptome in the hippocampus, but only mildly in the cerebral cortex. Furthermore, the transcriptome changes in the hippocampus are enriched in dendrite and synapse pathways. We also found that knockout of Hs6st2 decreases HS levels and impairs dendritic spines in hippocampal CA1 pyramidal neurons. Taken together, our study provides novel molecular and behavioral insights into the role of Hs6st2 in the brain, which facilitates a better understanding of HS6ST2 and HS-linked brain disorders.

The Diabetic Issues Related to a Familial Case of Hemoglobin Wayne: A Case Report and Review

Diabetes is a common disorder of carbohydrate metabolism that produces significant complications when either poorly treated or overtreated. Before 1978, the HgbA1c modality was not available to diagnose or monitor diabetes but now has become the standard of care. The results from this laboratory test are proportional to the glycosylation of hemoglobin and represents an accepted measure of glycemic control. Effects of hemoglobinopathies depend on their quaternary structure and have been shown to have impact HgbA1c results. Hgb Wayne is a rare hemoglobinopathy that occurs from a frameshift mutation in which either an asparagine (Hgb Wayne 1) or aspartic acid (Hgb Wayne 2) is located at residue 139 of the HBA2 gene. When separated by electrophoresis, this peak appears very close to that of the HgbA1c. Most HgbA1c monitoring equipment is either electrophoresis or ion exchange high-performance liquid chromatography which combine these two peaks together as one, falsely elevating the patient’s HgbA1c level. This co-elution can create an incongruity between HgbA1c levels and those of random glucose readings. Acting upon a falsely elevated HgbA1c with medication risks life-threatening hypoglycemia. In these following cases, this is explored with two related patients diagnosed independently by separate physicians in the same practice.

THU253 The Hemoglobin Wayne Variant And Association With Falsely Elevated HbA1c

Abstract Disclosure: N. Mulpuri: None. A. Bryant: None. D. Shahin: None. K. Soe: None. Background: Hemoglobin Wayne (Hb Wayne) is a rare, silent alpha chain variant caused by a frameshift mutation in the HbA2 gene. Although clinically silent, this mutation falsely elevates HbA1c values. Clinical cases: We are presenting three cases of Hb Wayne patients referred to our diabetes clinic within the last 5 years. All three cases were Caucasian-American males diagnosed with uncontrolled diabetes based on high HbA1c values of ranging from 10.1-10.6 %. One of the patients was initially started on metformin while the other patients’ treatment plan included dietary and lifestyle modifications. Review of the labs showed that renal function, complete blood count and fasting plasma glucose were within the normal range. High HbA1c value was noted by routine screening lab without having any symptoms related to DM or features of insulin resistance. The discrepancy between high HbA1c values and other glycemic index parameters (serum glucose and FSBG values) was noted. Subsequently, further work up was done (repeat HbA1c with different assay and fructosamine) to verify the diagnosis of uncontrolled DM. Fructosamine levels and repeat HbA1c with a different assay (enzymatic assay at Quest lab) were normal. Hemoglobin electrophoresis confirmed presence of an abnormal alpha variant consistent with Hb Wayne. The patients were reassured and educated about this Hb variant, and no further treatment for DM was pursued. Conclusion: Rare hemolgobinopathies may be more common than previously expected as they can be clinically silent and easily overlooked. While HbA1c has been an important clinical tool for diagnosis and management of diabetes, clinicians should look for underlying reasons which can affect HbA1c assay if there is any discrepancy between HbA1c, FSBG and plasma glucose values. The laboratory at our institution uses cation- exchange High Performance Liquid Chromatography method (Bio-Rad D-100 instrument) resulting in falsely high HbA1c values. Some hemoglobinopathies can affect the widely used HbA1c testing method such as CE-HPLC. The impact on HbA1c values will differ depending on hemoglobin variant and specific method and assay used. Given the limitations of HbA1c testing, clinicians should avoid relying heavily on HbA1c values in management and diagnosis of diabetes. It is vital that clinicians use their clinical judgment to correlate HbA1c with other clinical parameters such as continuous glucose monitoring data, glycated albumin,1,5 anhydroglucitrol (1,5 –AG), fingerstick blood glucose, plasma glucose and fructosamine values. Presentation: Thursday, June 15, 2023

Incidental finding of rare hemoglobin: hemoglobin Bari in northeast Spain

Abstract Objectives Cation exchange high-performance liquid chromatography (HPLC) is one of the techniques available for determining glycated hemoglobin (HbA1c) and also the method of choice for structural hemoglobinopathies screening. The objective of this case is to show how in a routine HbA1c test it is possible to incidentally find a hemoglobinopathy. Case presentation In a routine blood analysis, an abnormal value for the hemoglobin A2 (HbA2) was obtained during the study of HbA1c with HPLC on the ADAMS™ A1c HA-8180T. After suspecting it could be due to the presence of a hemoglobinopathy, the study of possible variants was expanded using electrophoresis and HPLC on the Hydrasys and Variant II analysers, respectively. Since it could not be identified by these conventional methods, a genetic study was also carried out using Sanger sequencing. The patient presented a low HbA2 (1.3 %) and a 24.9 % variant with a retention time of 1.95 min, compatible with alpha-globin chain variant. In the genetic study, the pathogenic variant c.138C&gt;G was detected in the HbA 2 gene in heterozygosis, which resulted in the expression of the structural hemoglobinopathy known as hemoglobin Bari. Conclusions The initial screening for structural hemoglobinopathies allows its identification or suspicion especially when it was performed with HbA1c analysis, requiring subsequent confirmation and diagnosis by other techniques.

Soluble-protein-aggregate-assisted improvements in heat-induced gel properties: Effect of genipin-mediated crosslinks on egg white protein

Genipin, a covalent crosslinker, has attracted significant attention from the food industry. Herein, the color, heat-induced gelling properties, and soluble aggregate character of the genipin-treated egg white were investigated to clarify the impact of soluble protein aggregates on the gel properties of egg white protein.After genipin pretreatment, the egg white protein turned dark blue and retained this color after heat-induced gelling. The genipin-pretreated egg white protein gel exhibited up to 2.9-fold and 13% higher breaking strength and strain, respectively, compared to non-treated egg white gel. The gel-breaking strength and strain correlated well with the color, before and after gelling. Gel electrophoresis, size exclusion, and anion exchange high-performance liquid chromatography revealed that a soluble protein aggregate with a negatively charged surface formed during pretreatment. The genipin-treated egg white protein formed a finely structured gel with high breaking strength and strain at all tested NaCl concentrations, indicating that the enhanced negative charge of the surface did not contribute to improving the gel properties.The soluble protein aggregates formed via covalent crosslinking are important for improving gel properties. The proposed method is a novel environmentally friendly method for enhancing the gel properties of egg white protein.

Thalassemia and Hemoglobinopathy Screening in Women Attending Antenatal Clinic at a Tertiary Care Center in Uttarakhand, India: A Re-look at the Laboratory Parameters Mandating High-Performance Liquid Chromatography Workup.

Thalassemia and hemoglobinopathies are the most common inherited hematological disorders. Of these, β thalassemia is the commonest disorder reported in India, followed by certain hemoglobinopathies encountered in different regions of the country. The data pertaining to the incidence of these disorders in the Uttarakhand region of India are sparse. To ascertain the prevalence and spectrum of thalassemia/hemoglobinopathies amongst antenatal women in Uttarakhand. The study also aimed to analyze the ability of red cell indices in differentiating beta thalassemia trait (BTT) from mild iron deficiency anemia (IDA). A total of 460 pregnant women in the first trimester of pregnancy were screened by cation exchange high-performance liquid chromatography. Retention time and proportions of normal/abnormal hemoglobin peaks were documented in all cases. Hemoglobin A2 (HbA2) values of ≥4% were taken as a cut-off for diagnosing BTT. Blood samples were also collected for complete blood counts, reticulocyte counts, and serum ferritin. The ability of the various discriminatory indices to differentiate between IDA and BTT was also assessed. The prevalence of BTT and hemoglobin D-Punjab trait amongst pregnant women was found to be 2.6% and 0.2%, respectively. RBC count, mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH) were found to be moderately strong predictors of BTT, with an area under the curve of 0.860, 0.857, and 0.842, respectively, which were comparable to the discriminatory indices found to be most useful in this study. In view of the 2.6% prevalence of BTT in antenatal women in this region of Uttarakhand, a routine screening will be helpful in detecting carriers early in the antenatal period. Careful interpretation of red cell indices is crucial to the distinction between BTT and IDA. Discriminatory indices are reasonably accurate in differentiating BTT from mild iron deficiency, but for practical purposes, MCV and MCH provide equivalent information to identify cases that require further workup.

Comparison of HbA2 Using High Performance Liquid Chromatography Versus Haemoglobin Capillary Zone Electrophoresis.

Thalassemia is among the most common hereditary disorders in the world. Approximately 5% of the world's population are carriers of hemoglobinopathies, and 2.9% are carriers of beta thalassemia. Haemoglobin A2 (HbA2) constitutes less than 3% of the total hemoglobin (Hb) in adults, and the determination of Hb A2 levels is important to diagnose the beta thalassemia trait(BTT). In some cases, the level of HbA2 is not typically elevated, and some difficulties may arise in making the diagnosis. Cation exchange high-performance liquid chromatography (HPLC) and HbCZE (haemoglobin capillary zone electrophoresis) are considered acceptable methods to diagnose BTT, but these vary in their accuracy and cut-offs. In this study, we attempted to compare HbA2 values using two methods, HPLC and HbCZE, in 536 whole blood samples sent by physician-ordered hemoglobinopathy screening over two years. This included antenatal women, patients with anemia not responding to iron, and cases of familial screening where either a child or a sibling had been diagnosed with hemoglobinopathy or thalassemia. The performance characteristics of both machines were compared for the detection of the 5 most common hemoglobin variants: Hb A, HbF, HbS, Hb C, and HbE. On comparing the HbA2 values, the HPLC showed higher values for HbA2 as compared to HbCZE, while the HbF and HbS measurement agreement was good between both methods. Normal ranges and mean normal values of HbA2 differ between different methods and different manufacturers; hence, each institute using these machines should validate its cutoffs.

SPECTRUM OF HEMOGLOBINOPATHIES AND THALASSEMIAS DIAGNOSED ON HPLC - A TERTIARY CARE HOSPITAL BASED STUDY

Background - The most common single gene disorders in the world are hemoglobinopathies and thalassaemias. The prevalence of thalassaemias and haemoglobinopathies varies by region. However, some communities have a very high incidence due to consanguinity, caste, and area endogamy, making this group of diseases a major public health problem in our country. High performance liquid chromatography (HPLC) is an automated instrument that is highly sensitive and specic, has a high resolution, and aids in the quantication of various haemoglobins. It is a viable alternative to electrophoresis. the study comp Materials and method - rises of total 220 patients presented with anaemia and were examined in the department of Medicine. Thereafter, blood smaples were taken and the hemoglobin typing were done in the department of Pathology by Cation exchange high performance liquid chromatography. - Among the 220 cases Results majority were females with 64.1% of cases and 35.9% (79) of cases are male. Out of total cases, 119 (54.1%) cases had normal hemoglobin and 101 (45.9%) cases had variant hemoglobin. Out 101 cases of variant hemoglobin, 38 (17.3%) cases were diagnosed with Hb E trait, 27 (12.3%) cases were detected with Hb E disease, 18 (8.2%) cases were diagnosed with Hb E-β Thalassemia, 17 (7.7%) cases were diagnosed as βThalassemia trait and 1 (0.5%) case was detected as β-Thalassemia major

Biomarkers of seafood intake during pregnancy – Pollutants versus fatty acids and micronutrients

Intake of fish and seafood during pregnancy may have certain beneficial effects on fetal development, but measurement of intake using questionnaires is unreliable. Here, we assessed several candidate biomarkers of seafood intake, including long-chain omega 3 fatty acids (n-3 LCPUFA), selenium, iodine, methylmercury, and different arsenic compounds, in 549 pregnant women (gestational week 29) in the prospective birth cohort NICE (Nutritional impact on Immunological maturation during Childhood in relation to the Environment). Proportions of the fatty acids eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in erythrocytes were measured using gas chromatography with flame ionization detector. Selenium was measured in blood plasma and erythrocytes, mercury and arsenic in erythrocytes, and iodine and several arsenic compounds in urine, using inductively coupled plasma mass spectrometry, arsenic compounds after first being separated by ion exchange high-performance liquid chromatography (HPLC). Each biomarker was related to intake of total seafood and to intake of fatty and lean fish, and shellfish in third trimester, estimated from a semi-quantitative food frequency questionnaire filled out in gestational week 34. The pregnant women reported a median total seafood intake of 184 g/week (5th-95th percentiles: 34–465 g/week). This intake correlated most strongly with erythrocyte mercury concentrations (rho = 0.49, p < 0.001), consisting essentially of methylmercury, followed by total arsenic in erythrocytes (rho = 0.34, p < 0.001), and arsenobetaine in urine (rho = 0.33, p < 0.001), the main form of urinary arsenic. These biomarkers correlated well with intake of both fatty fish, lean fish, and shellfish. Erythrocyte DHA and plasma selenium correlated, although weakly, mainly with fatty fish (rho = 0.25 and 0.22, respectively, both p < 0.001). In conclusion, elevated concentrations of erythrocyte mercury and urinary arsenobetaine can be useful indicators of seafood intake, more so than the n-3 LCPUFAs. However, the relative importance of the biomarkers may differ depending on the type and amount of seafood consumed.

Hearing loss in Type 2 diabetes: Impact of duration, glycemic control, and oxidative stress

Background: Type 2 diabetes mellitus (T2DM) has been linked to many problems, including hearing loss, which research studies have not paid much attention to. This study looks into the possible links between hearing loss in people with T2DM, the duration of time they have had diabetes, how well they control their blood sugar, and measures of reactive stress. Understanding how these things work together can help doctors find problems faster, develop better ways to treat them, and improve their patients’ health. Aims and Objectives: This study aims to see if there are any links between hearing loss and duration of T2DM, levels of glycemic control, and measures of oxidative stress in people with T2DM. The results of this study will help come up with early identification and healing ways to improve patient care. Materials and Methods: In a cross-sectional study at Government Medical College, Kozhikode, 63 diabetic patients aged 30–60 were compared with 63 age and sex-matched controls. Blood sugar was assessed using the glucose oxidase peroxidase method, hemoglobin A1C (HbA1C) through cation exchange high-performance liquid chromatography, serum malondialdehyde (MDA) through the thiobarbituric acid test, and superoxide dismutase (SOD) using the technique by Marklund and Marklund, with the latter two assessed spectrophotometrically. Hearing abilities were evaluated using pure tone audiometry. Results: Diabetic participants exhibited a marked increase in hearing loss incidence compared to controls (P &lt; 0.001). Males with diabetes showed a higher prevalence of hearing loss than females (P = 0.043). A significant correlation was found between hearing loss and the duration of diabetes (P &lt; 0.001), elevated glycemic levels (fasting blood sugar, random blood sugar, and HbA1c, all P &lt; 0.001), and altered oxidative stress parameters. Specifically, MDA levels were higher in people with diabetes (P &lt; 0.001) and associated with hearing loss (P = 0.033), while SOD levels were reduced (P &lt; 0.001) and significantly linked to hearing loss (P = 0.047). Logistic regression identified age, sex, HbA1c, MDA, and SOD as independent risk factors for hearing impairment in Type 2 diabetes patients. Conclusion: Our findings emphasize the significant association between Type 2 diabetes and heightened risk of hearing loss, influenced by age, gender, glycemic levels, and oxidative stress markers. Regular audiological assessments are crucial for early detection and intervention in diabetic patients.

Structural Analysis of Phosphorylation Proteoforms in a Dynamic Heterogeneous System Using Flash Oxidation Coupled In-Line with Ion Exchange Chromatography.

Protein posttranslational modifications (PTMs) are key modulators of protein structure and function that often change in a dynamic fashion in response to cellular stimuli. Dynamic PTMs are very challenging to structurally characterize using modern techniques, including covalent labeling methods, due to the presence of multiple proteoforms and conformers together in solution. We have coupled an ion exchange high-performance liquid chromatography separation with a flash oxidation system [ion exchange chromatography liquid chromatography-flash oxidation (IEX LC-FOX)] to successfully elucidate structural changes among three phosphoproteoforms of ovalbumin (OVA) during dephosphorylation with alkaline phosphatase. Real-time dosimetry indicates no difference in the effective radical dose between peaks or across the peak, demonstrating both the lack of scavenging of the NaCl gradient and the lack of a concentration effect on radical dose between peaks of different intensities. The use of IEX LC-FOX allows us to structurally probe into each phosphoproteoform as it elutes from the column, capturing structural data before the dynamics of the system to reintroduce heterogeneity. We found significant differences in the residue-level oxidation between the hydroxyl radical footprint of nonphosphorylated, monophosphorylated, and diphosphorylated OVA. Not only were our data consistent with the previously reported stabilization of OVA structure by phosphorylation, but local structural changes were also consistent with the measured order of dephosphorylation of Ser344 being removed first. These results demonstrate the utility of IEX LC-FOX for measuring the structural effects of PTMs, even in dynamic systems.

Hemoglobinopathies by HPLC: A 3 Year Study of 106,277 Cases

Introduction: Hemoglobinopathies and thalassemias are the most common single gene disorders in the world. World Health Organization figures estimate that 5% of the world populations are carriers of a potentially pathological hemoglobin (Hb) gene. The general incidence of thalassemia trait and sickle cell anaemia in India varies between 3-17% and 1-44% respectively3 but because of consanguinity, caste and area endogamy, some communities show a very high incidence, making the disease a major public health problem in our country. Cation exchange high-performance liquid chromatography (CE-HPLC) is one of the best methods for screening, detection, and identification of various hemoglobinopathies.&#x0D; Material &amp;Method: A retrospective study was carried out from period of 2017 to 2019 with 106277 cases evaluated with an aim to identify various hemoglobinopathies seen in Indian population by high-performance liquid chromatography. Cases outside Indian geographical location were excluded from the study&#x0D; Result: A total of 18,936(17.82%) cases with abnormal haemoglobin variants was reported in the study with 35 difference variants across India. Northeast India reported maximum abnormal hemoglobinopathies (50.16%). Beta Thalassemia Trait was the most common abnormal variant found.Such a high incidence emphasises premarital and prenatal screening for prevention of dangerous effects of hemoglobinopathies in the population.&#x0D; Conclusion: CE-HPLC should be used for early detection and proper management of these haemoglobinopathies. The most common hemoglobinopathy observed in our study was Beta thalassemia trait followed by Sickle cell trait and then sickle cell disease. It was also observed that Northeast India had maximum abnormal hemoglobinopathies.

Examination of the primary fraction of hemoglobin in individuals having sickle cell disease using high-performance liquid chromatography

Background: Hemoglobinopathies refer to a range of diseases, in which the hemoglobin (Hb) molecule’s synthesis or structure is aberrant. It is passed down through the generations (inherited). Hb C illness, Hb S-C disease, sickle cell anemia, and thalassemia are all part of this group. Hemoglobinopathies are the most frequent genetically inherited red blood cell condition on the planet. Hb variant screening and precise identification have become more crucial in the antenatal diagnosis and prevention of Hb diseases. Aims and Objectives: Hb analysis, cation exchange high-performance liquid chromatography (HPLC) has emerged as the method of choice. This research was brought up to diagnose numerous hemoglobinopathies and also to measure distinct Hb fractions. Materials and Methods: Four hundred and seventy participants were examined for hemoglobinopathies in the investigation. Different fractions of Hb were compared to patients with normal Hb after diagnosis. Results: Normal HPLC, SCA (Hb SS), sickle cell trait (SCT), and -thalassemia trait were discovered in 110 (23.4%), 130 (27.6%), 210 (44.6%), and 20 (4.2%) individuals, respectively, out of 470 patients. Rare hemoglobinopathies such as tenacious fetal Hb (PFH), Hb E, Hb D-Punjab, and Hb Q India accounted for 15 (3.1%) of the sufferers. Patients with SCA had a mean percent of Hb S, Hb F, Hb A, and Hb A2 of 81.6±74.6, 22.9±13.9, 3.1±6.1, and 2.5±1.02, respectively. Hb F was 22.9±13.9% on average, which was much higher than normal and SCT. A high HbA2 level (&gt;3.5%) indicated the existence of the β-thalassemia trait. Conclusion: In the included section of the population, SCD is the most common kind of hemoglobinopathy, both homozygous and heterozygous. Hb F concentrations are observed to be elevated in SCA patients, and it is thought to be a key element in protecting patients from problems. Raised Hb A2, which indicates the presence of the β-thalassemia trait, was also discovered in this area, and it is suspected when the value is &gt;3.7%. Cation exchange HPLC is ideal for routine hemoglobinopathies research due to its high resolution, short test time, and precise quantification.

Degradation and in-use stability study of five marketed therapeutic monoclonal antibodies by generic weak cation exchange liquid chromatographic method ((WCX)HPLC/DAD)

Therapeutic monoclonal antibodies (mAbs) represent a very important class of the current biopharmaceutics. The great complexity of their structure made necessary the use of different analytical approaches for assessing different physico-chemical properties. In this work, weak cation exchange (WCX) high performance liquid chromatography with diode array detection ((WCX)HPLC/DAD) is used to assess the charge variant profile. The method here developed combined the effect of ionic strength and controlled pH gradient and allows for the charge variants analysis of the five mAbs studied, namely bevacizumab (BVZ), cetuximab (CTX) infliximab (INF), rituximab (RTX) and trastuzumab (TTZ), which are among the most used mAbs worldwide. The differences in the charge variants in the natural isoforms of the mAbs promoted characteristic WCX chromatograms for each of mAbs that can be also useful for identification purposes. These chromatograms have provided to be suitable for tracking changes in the charge variants of each mAb analyzed both in controlled degraded and in stabilities study along time of in-use samples solutions at 2 mg/mL in 0.9% NaCl stored refrigerated (at 4 °C) and frozen (−20 °C) for two months. The results obtained indicated different stabilities of these mAbs, all IgG1, against degradation by different stressed environmental conditions and in-use stability along two months.

Production and Conjugation of Truncated Recombinant Diphtheria Toxin to VEGFR-2 Specific Nanobody and Evaluation of its Cytotoxic Effect on PC-3 Cell Line.

Immunotoxins have represented a great potency in targeted therapeutics to encounter tumors. They consist of a protein toxin conjugated to a targeting moiety, which recognizes a specific antigen on surface of cancer cells and accordingly induces cell death by toxin segment. The targeting part could be a nanobody, which is a group of antibodies composed of an only functional single variable heavy chain (VHH).Therefore, this study was done to produce an immunotoxin (VGRNb-DT) by chemical conjugation of a truncated diphtheria toxin moiety to an anti-vascular endothelial growth factor receptor 2(VEGFR-2) nanobody, and to identify effectiveness of immunotoxin in recognizing the VEGFR-2- positive cancer cells and inhibiting cell growth and survival. Diphtheria toxin was expressed and purified by nickel affinity chromatography, and accordingly, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis confirmed its expression. Function of heterobifunctional crosslinkers, Sulfo-SMCC (sulfosuccinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate), and SATP (N-succinimidyl-S- acetylthiopropionate) for bioconjugation purposes was acknowledged by cation exchange high-performance liquid chromatography (HPLC). Cytotoxicity of immunotoxin was evaluated on the VEGFR-2 positive PC-3 cell line by MTT assay.Overexpression of VEGFR-2 in the PC-3 cell line allowed immunotoxin to recognize them by anti-VEGFR-2 nanobodies. The concentrations above 5 μg/ml represented a significant decrease in cell survival rate in PC-3 cells compared to HEK293 cells (VEGFR-2 negative cells) as controls.VGRNb-DT demonstrated a successful bioconjugation; furthermore, variable concentrations were correlated with cell death in prostate cancer PC-3 cells.

Hb Kirikiriroa [α57(E6)Gly→Cys; HBA1: c.172G>T]: A Novel Unstable α-Globin Variant with Oxidized Derivatives Interfering with Hb A1c

We report the identification of a novel hemoglobin (Hb) variant [α57(E6)Gly→Cys; HBA1: c.172G>T], to be referred to as Hb Kirikiriroa. The variant was detected in five subjects from two families, with familial relationship established between the families following diagnosis. A persistently elevated Hb A1c over a 1-year period prompted hemoglobinopathy screening in an adolescent male of New Zealand (NZ) European descent (case 1). Capillary electrophoresis (CE) revealed the variant was negatively charged and susceptible to oxidation, with multiple abnormal peaks detected (0.4–5.1% total Hb). Hb A1c analysis by cation exchange high performance liquid chromatography (HPLC) was the first indication of the variant in a pregnant female of NZ European descent (case 2). Cases 1 and 2 had normal complete blood counts. Isopropanol stability testing provided evidence the variant was unstable. We herein describe the characterization of Hb Kirikiriroa and clinical significance of the variant for interference with Hb A1c analysis by CE and cation exchange HPLC.

Engineering immunomodulatory nanoplatforms from commensal bacteria-derived polysaccharide A.

Capsular zwitterionic polysaccharides (CZPs), typically found on the surfaces of commensal gut bacteria, are important immunomodulatory molecules due to their ability to produce a T cell dependent immune response upon processing by antigen presenting cells (APCs). Their immunological activity makes them potentially useful for generating material constructs that are applicable for the treatment of diseases, or as vaccines. Herein, we explored synthetic strategies to generate immunologically active polymer-carbohydrate conjugates and nanomaterials of the CZP, Polysaccharide A (PSA) derived from Bacteroides fragilis. Initially, we addressed the purification of PSA, which is critical for the realization of materials applicable for biomedical purposes. Anion exchange high performance liquid chromatography in the presence of a surfactant (CHAPS) enabled the isolation of pure PSA. Through modification of purified PSA with azide groups, we demonstrated that polymers or antigens could be incorporated with PSA via click chemistry reactions to generate conjugates that can be fabricated into nanoparticles. By conjugation of PSA with a DBCO end functionalized polyphosphoester polymer with hydrophobic pendant terminal alkyne groups, an amphiphilic conjugate was obtained which formed nanoparticles of about 100 nm in aqueous solution. Moreover, terminal alkyne groups could be modified with charged thiol molecules (amine/carboxylate) via thiol-yne radical chemistry to generate conjugates, which could be incorporated into nanoparticles via electrostatic interactions building onto a charged nanoparticle template. The conjugates and nanoparticles exhibited immunological activity as assessed by the toll-like receptor 2 (TLR2) activation assay and positive cytokine production (IL-10) following their co-incubation with APCs and T cells. Summarily, this work plainly demonstrates chemical biology strategies for fabricating immunomodulatory nanomaterials from commensal microorganisms that can potentially be novel vaccines or immunotherapeutics.

Combination of strong anion exchange liquid chromatography with microchip capillary electrophoresis sodium dodecyl sulfate for rapid two-dimensional separations of complex protein mixtures

Two-dimensional separations provide a simple way to increase the resolution and peak capacity of complex protein separations. The feasibility of a recently developed instrumental approach for two-dimensional separations of proteins was evaluated. The approach is based on the general principle of two-dimensional gel electrophoresis. In the first dimension, semi-preparative strong anion exchange high-performance liquid chromatography is utilized and fractions are collected by means of a fraction collector. They are subsequently analyzed in the second dimension with microchip capillary electrophoresis sodium dodecyl sulfate. Microchip capillary electrophoresis provides the necessary speed (approximately 1 min/fraction) for short analysis. In this study, three different samples were investigated. Different constructs of soluble guanylyl cyclase were expressed in Sf9-cells using the baculovirus expression system. Cell lysates were analyzed and the resulting separations were compared. In our experimental setup, the soluble guanylyl cyclase was identified among hundreds of other proteins in these cell lysates, indicating its potential for screening, process control, or analysis. The results were validated by immunoblotting. Samples from Chinese hamster ovary cell culture before and after a purification step were investigated and approximately 9% less impurities could be observed. The separation patterns obtained for human plasma are closely similar to patterns obtained with two-dimensional gel electrophoresis and a total of 218 peaks could be observed. Overall, the approach was well applicable to all samples and, based on these results, further directions for improvements were identified.Graphical abstract.