Ion-exchange High-performance Liquid Chromatography Research Articles

High peak of carbamylated hemoglobin discordant with urea level: a case report

ABSTRACT Hemoglobin A1c (HbA1c) measurement is commonly performed in diabetes mellitus patients to monitor glycemic control over the last three to four months. Carbamylated hemoglobin, which is the hemoglobin that binds to isocyanic acid derived from urea, is one of the possible analytical interference in the uremic patient. When measured by ion-exchange high-performance liquid chromatography (HPLC), carbamylated hemoglobin forms a peak that overlaps the peak of HbA1c, causing a falsely elevated HbA1c result. We report a case of a 60-years-old man who had a spurious increase in HbA1c, with a high carbamylated hemoglobin peak disproportionate to the urea value. Subsequent hemoglobin analysis using hemoglobin electrophoresis and HPLC hemoglobin testing system suggested hemoglobin J (Hb J) variant. Our case highlighted the possibility of misleading HbA1c interpretation in the presence of a high carbamylated hemoglobin peak, but not proportionate to urea value. In this study, Hb J was detected. A method free from hemoglobin variant interference should be used ideally, and monitoring glycemic control should be performed using alternative methods, such as serum fructosamine or continuous glucose monitoring.

Facile synthesis of the Z-scheme graphite-like carbon nitride/silver/silver phosphate nanocomposite for photocatalytic oxidative removal of nitric oxides under visible light

In this study, a novel ternary Z-scheme Graphite-like Carbon Nitride (g-C3N4)/Silver (Ag)/Silver Phosphate (Ag3PO4) photocatalyst was designed and prepared using a two-step method (sodium chloride (NaCl) template-assisted strategy plus selective deposition). Its photocatalysts performance against removing 400 ppm of Nitric Oxides (NOx) was then investigated. We found 50 wt% g-C3N4/Ag/Ag3PO4(AP-CN 2:1) catalyst removes up to 74% of NO in 90 min under the illumination of visible light (>420 nm), which is respectively 3.5 and 1.8 times higher than using g-C3N4 or Ag3PO4, alone. This improved performance was attributed to the formation of Z-scheme g-C3N4/Ag/Ag3PO4 heterojunction, driven by the built-in electric field across the g-C3N4/Ag/Ag3PO4 interface. These separated the electron-hole but enhanced the original strong oxidation and reduction performance of related components. The superior performance is also attributed to the improved surface area, enhanced hydrophilicity (H2O2) and better visible-light-harvesting capability of the composite compound. More importantly, the AP-CN 2:1 sample maintained a NO removal rate of more than 73% even after four rounds of recycling. The photocatalytic oxidation removal mechanism was evaluated using the radical-capture experiments, electron spin resonance (ESR) and ion-exchange high-performance liquid chromatography (HPLC) analysis. The findings of this work offer a simple but effective design of a highly reactive and practical ternary Z-scheme heterojunction photocatalysts for the removal of toxic NO.

Assessment of MGMT methylation status using high-performance liquid chromatography in newly diagnosed glioblastoma

BackgroundThe utility of O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation status as a prognostic marker in patients with glioblastoma (GBM) has been established. However, the number of CpG sites that must be methylated to cause transcriptional silencing remains unclear, and no significant consensus exists on the optimal method of assessing MGMT methylation. We developed a new high-performance liquid chromatography (HPLC) method that enables accurate analysis of DNA methylation levels using long PCR products. In the present study, we analyzed the MGMT methylation status of 28 isocitrate dehydrogenase–wild-type GBMs treated with temozolomide using ion-exchange HPLC and set the optimal cutoff values.ResultsWe designed three primers for separate regions (regions 1–3) that had 21 to 38 CpGs for PCR and validated the MGMT promoter methylation status using frozen samples. There was a strong correlation between HPLC and bisulfite sequencing results (R = 0.794). The optimal cutoff values for MGMT methylation in HPLC were determined to allow differentiation of patient prognosis by receiver operating characteristic curve analysis. The cutoff values were 34.15% for region 1, 8.84% for region 2, and 36.72% for region 3. Kaplan–Meyer curve analysis estimated that the most differentiated prognosis was enabled in the setting of 8.84% methylation of MGMT in region 2. Progression-free survival and overall survival were significantly longer for patients in this setting of region 2 methylation (p = 0.00365 and p = 0.00258, respectively).ConclusionsThe combination of our HPLC method and the original primer setting provides a new standard method for determination of MGMT methylation status in patients with GBM and is useful for refining MGMT-based drug selection.

Ultra-performance liquid chromatography (UPLC) for the determination of organic acids – The intermediates of branched-chain amino acid biosynthesis in Escherichia coli strains

Simple and rapid reverse-phase ultra-performance liquid chromatography with UV-detection (RP-UPLC-UV) was developed and validated for the simultaneous analysis of 2-isopropylmalate (2-IPM), 3-isopropylmalate (3-IPM), ketoisovalerate (KIV), ketoisocaproate (KIC), and α-keto-β-methylvalerate (KMV) in the culture fluid (CF) of branched-chain amino acid (BCAA) Escherichia coli strain producers. The RP-UPLC-UV method was developed using a Waters Acquity BEH C18 column (100 mm × 2.1 mm, 1.7 μm) with a mobile phase consisting of phosphate monobasic salt adjusted to a pH of 3.5 and methanol solution. The flow rate of the mobile phase was 0.5 mL min−1 with gradient elution. The RP-UPLC-UV method was compared with reverse-phase high-performance liquid chromatography with UV-detection (RP-HPLC-UV), ion-exchange high-performance liquid chromatography with UV-detection (IE-HPLC-UV), and ion-exchange high-performance liquid chromatography with electrochemical detection (IE-HPLC-ECD) and a postcolumn buffer for organic acid analysis. The proposed RP-UPLC-UV method was highly sensitive (LOD for KIV was 2.5 × 10−3 mg mL−1, for 2-IPM – 4.5 × 10−3 mg mL−1, for 3-IPM – 4.4 × 10−3 mg mL−1, for KIC – 3.4 × 10−3 mg mL−1, and for KMV – 2.8 × 10−3 mg mL−1) and successfully applied for the analysis of organic acids in the CF of E. coli strain producers.

The role of metformin hydrochloride in complex therapy of disorders of carbohydrate metabolism in patients with paranoid schizophrenia treated with atypical antipsychotics

Introduction. According to the literature, mortality among patients with schizophrenia is 1.5 -2 times higher than in the healthy population. One explanation for this is the complication of neuroleptic therapy, which, according to various authors, occurs in 2 to 100% of cases.
 Purpose. We aimed to study some indicators of carbohydrate metabolism disorders in patients with paranoid schizophrenia who have been taking neuroleptics for a long time, to correct the established changes by adding metformin hydrochloride to the standard regimen and to monitor its effectiveness.
 Methodology. The study was conducted based on Municipal non-commercial enterprise "Precarpathian regional clinical center of mental health of Ivano-Frankivsk regional council. This study included patients diagnosed with paranoid schizophrenia according to the criteria of ICD-10 (F20.0). As a result of our studies in 63 patients, we found a violation of carbohydrate metabolism, which accounted for 52% of all examined. Among them, 55 patients with prediabetes: 12 (19.04%) patients with impaired glucose tolerance (IGT), 43 (68%) with impaired fasting glycemia (IFG), and 8 patients (12.7%) with type 2 diabetes mellitus (T2D). Subsequently, all these 63 patients were prescribed corrective therapy with a drug from the group of biguanides - metformin hydrochloride at a dose from 500 to 1000 mg/day: in violation of IFG at a dose of 500 mg/day; in case of IGT - 850 mg/day; in the case of T2D- 1000 mg/day. All studies were performed before and after 3 months of metformin correction. These included fasting glucose, postprandial hyperglycemia (PPG) (two hours after a meal), glycosylated hemoglobin (HbAIc), immunoreactive insulin (IRI), and, if necessary, an oral glucose tolerance test (OGTT). Fasting plasma glucose (FPG) was measured by the glucose oxidase method. HbAIc values were determined by ion-exchange high-performance liquid chromatography (HPLC). The determination of the IRI level was performed by enzyme-linked immunosorbent assay (ELISA)
 Results and Discussion. The results of the research showed that 52% of all surveyed found disorders of carbohydrate metabolism. They were prescribed corrective therapy with a drug from the group of biguanides - metformin hydrochloride at a dose of 500 to 1000 mg/day. As a result of the research, we found that in all groups of examined patients revealed a positive dynamics of carbohydrate metabolism under the influence of this drug. A significantly higher therapeutic effect of the treatment of carbohydrate metabolism disorders with metformin was found in patients receiving the latter in combination with haloperidol. The combination of metformin with risperidone and quetiapine showed a slightly lower clinical effect.
 Conclusion. Our own clinical experience gives grounds to recommend metformin hydrochloride as a medium for the correction of carbohydrate metabolism disorders in patients with a paranoid form of schizophrenia in the treatment of this category of patients with neuroleptics

Rapid In-Process Monitoring of Lentiviral Vector Particles by High-Performance Liquid Chromatography

Lentiviral vectors (LVs) are a popular gene delivery tool in cell and gene therapy and they are a primary tool for ex vivo transduction of T cells for expression of chimeric antigen receptor (CAR) in CAR-T cell therapies. Extensive process and product characterization are required in manufacturing virus-based gene vectors to better control batch-to-batch variability. However, it has been an ongoing challenge to make quantitative assessments of LV product because current analytical tools often are low throughput and lack robustness and standardization is still required. This paper presents a high-throughput and robust physico-chemical characterization method that directly assesses total LV particles. With simple sample preparation and fast elution time (6.24 min) of the LV peak in 440 mM NaCl (in 20 mM Tris-HCl [pH 7.5]), this ion exchange high-performance liquid chromatography (IEX-HPLC) method is ideal for routine in-process monitoring to facilitate the development of scalable and robust LV manufacturing processes. Furthermore, this HPLC method is suitable for the analysis of all in-process samples, from crude samples such as LV supernatants to final purified products. The linearity range of the standard curve is 3.13 × 108 to 1.0 × 1010 total particles/mL, and both the intra- and inter-assay variabilities are less than 5%.

Detection of Hemoglobinopathies by HPLC in a Referral Clinical Laboratory in Nepal

Introduction: Various hemoglobin variants are prevalent in the Nepalese population owing to the ethnic diversity of our population. Detection of asymptomatic carriers by a reliable laboratory method is the cornerstone of prevention of this serious health problem. The simplicity of the automated system with internal sample preparation, superior resolution, rapid assay time, and accurate quantification of hemoglobin fractions makes ion-exchange high-performance liquid chromatography (IEX- HPLC) an ideal methodology for the routine screening for hemoglobinopathies. We report the clinical laboratory-based prevalence of variant hemoglobin and hemoglobinopathies through IEX- HPLC analysis in a cohort of patients referred for hemoglobin electrophoresis to a referral clinical laboratory in Nepal.
 Materials and Methods: The variant hemoglobin and hemoglobinopathy were diagnosed based on percentage, retention time, and peak characteristics of variant hemoglobin in a chromatogram. Peripheral blood films, reticulocyte count, serum iron profile, and sickling test were done in selected cases along with detailed family history.
 Results: Hemoglobinopathy was detected in all age group but the vast majority was detected between 20 to 40 years of age. Beta thalassemia trait was the most frequently detected hemoglobinopathy in all age groups.
 Conclusions: The present study conducted using IEX-HPLC reflects the magnitude of thalassemia and hemoglobinopathies in a laboratory-based population which helps to increase awareness among both health caregivers and the general population. Routine screening for hemoglobinopathy of individuals at the reproductive age group is recommended and this screening can be done through IEX-HPLC.

Identification of a new hemoglobin variant Hb Liuzhou [HBA1:C.182A→G] by MALDI-TOF mass spectrometry during HbA1c measurement

Structural hemoglobin (Hb) variant is generally caused by a point mutation in the globin gene that produces one amino acid substitution. Here, we describe a new α-chain variant found during HbA1c measurement. HbA1c procedures based on both ion-exchange high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) techniques failed to identify its presence. In contrast, MALDI-TOF mass spectrometry (MS) revealed the existence of a variant α-chain with a mass of 15155 Da. In addition, the Hb variant interfered with HbA1c determined by Bio-Rad D100. DNA sequencing confirmed the occurrence of a new heterozygous mutation [HBA1:C.182A→G] at codon 60, resulting in a coding change from lysine to arginine. We named it Hb Liuzhou for thde birthplace of the patient. This case exemplified that MALDI-TOF mass spectrometry can serve as the method of choice to identify and quantify the Hb variant.

Ion-exchange HPLC-ICP-MS: A new window to chromium speciation in biological tissues

The presented work proposes a novel analytical ICP-MS-based approach for the accurate and precise chromium speciation in biological tissues. The determination of total Cr(VI) and soluble Cr(III) species was carried out by alkaline EDTA extraction followed by their separation using ion-exchange high-performance liquid chromatography inductively coupled plasma mass spectrometry (IE-HPLC-ICP-MS). The developed method was validated according to the procedure given in the United States Food and Drug Administration guideline on the validation of bioanalytical methods. Validation parameters included limit of detection (≤ 0.03 μg g−1), limit of quantification (≤ 0.08 μg g−1), linearity (r ≥ 0.9998), intra-day and inter-day accuracy (86–110%) and precision (≤ 10%), extraction recovery (89–110%), carry-over effect and sensitivity. In addition, special attention was paid to the study of chromium species interconversion and the elimination of spectral interferences. Moreover, the validated ICP-MS method employing microwave acid digestion was used to determine the total Cr content in collected fractions. Finally, the whole ICP-MS-based methodology was applied to the analyses of two certified reference materials of hepatopancreas tissue. Obtained results indicated that the majority of chromium in biological tissues is bound to the solid residue, Cr(VI) was determined in none of the samples investigated. This is the first study focusing on soluble Cr(III), total Cr(VI), and total bound Cr species in biological tissues. It is characterized by efficient sample preparation and fast simultaneous analysis of Cr species with parallel total Cr analysis serving for chromium balance evaluation.

SAT-396 INTESTINAL PERMEABILITY IS IMPAIRED IN PATIENTS WITH GLOMERULAR DISEASES

Recent data link a dysregulated ‘gut-kidney axis’ to the development of immunoglobulin A nephropathy (IgAN), which may set the stage for more specific therapeutic approaches. Here, we aimed to analyze whether IgAN patients have a disturbed intestinal barrier function. We conducted an observational, single-center study to assess gut permeability in 35 IgAN patients, 18 patients with other glomerular diseases and 19 controls. Baseline characteristics are displayed in table 1. After an overnight fast, trial participants ingested a multi-sugar solution (lactulose, L-rhamnose, sucralose and erythritol). Subsequently, urine was collected over a period of 0-2h, 2-5h, 5-24h post-administration. Quantification of the sugars was carried out using isocratic ion-exchange high performance liquid chromatography mass spectrometry. Markers of small-intestine (lactulose/rhamnose (L/R) ratio, 0-2h and sucralose/erythritol (S/E) ratio 2-5h post-administration) and colon permeability (sucralose/erythritol (S/E) ratio, 5-24h post-administration) were calculated and compared between groups. Patients with glomerular diseases displayed an increased small intestine permeability (L/R, 0-2h) compared to control individuals (p=0.008), yet this difference was only significant in patients with non-IgAN glomerulopathies and IgAN patients only exhibited a trend towards an elevated small intestinal permeability (Figure 1A/B). Furthermore, we observed a decreased excretion of sucralose (p<0.05) in IgAN patients after 24h. Yet, the S/E ratio over the 5-24h-period that reflects colon permeability only showed a trend towards a decreased ratio in these patients (Figure 1C). Neither the degree of proteinuria nor eGFR correlated with small intestinal or colon permeability ratios in the two patient groups. The present study suggests a disturbed intestinal permeability is common in patients with glomerular diseases and does not specifically occur in IgAN.

HbA1c levels measured by enzymatic assay during off-site health checkups are lower than those measured by on-site HPLC assay.

HbA1c is widely used as a therapeutic target marker and as a diagnostic marker for diabetes mellitus. This has led to an increasing frequency of HbA1c measurements in current health checkups throughout Japan. In the present study, we compared the HbA1c levels measured by an enzymatic assay (EA-HbA1c) off-site during health checkups with the HbA1c levels measured by on-site ion-exchange high-performance liquid chromatography (HPLC; HPLC-HbA1c) in a hospital. A total of 96 individuals (53 males and 43 females; age, 68.9 ± 8.4years old; 70 diabetic and 26 non-diabetic individuals) whose HbA1c levels were measured by both the methods listed above were included in the study. Since no HPLC-HbA1c levels were measured on the day of the health checkup, HPLC-HbA1c levels were estimated using HPLC-HbA1c levels measured before and after the health checkup. A significant correlation of HbA1c levels was observed between the two groups (R = 0.973; p < 0.001). However, EA-HbA1c levels measured off-site during health checkups are lower than estimated HPLC-HbA1c levels measured on-site (6.37 ± 0.75% vs. 6.69 ± 0.75%; p < 0.001). Since lower EA-HbA1c levels measured during health checkups, which diverged from on-site measurements, may lead to underestimating diabetes mellitus, accurate measurement of HbA1c is required irrespective of the measuring method. Further investigation of the cause of falsely low EA-HbA1c levels and the strategy for reconciling HbA1c to reflect plasma glucose accurately are warranted.

C>A substitution in NT 46 of the 3’ UTR region (the α complex protected region) of the alpha-1 globin gene: a non-deletional mutation or polymorphism?

AimsUntranslated regions (UTRs) play an important role in post-transcriptional regulation of gene expression, including by modulating messenger RNA (mRNA) transport out of the nucleus, translation efficiency, subcellular localisation and stability....

Red Meat and Inflammation and A1c in Breast Cancer Women (P05-038-19)

ObjectivesTo determine the associations of processed and unprocessed red meat with serum C-reactive protein (CRP) and hemoblobin A1c (HbA1c) among breast cancer survivors. We hypothesized that processed and unprocessed red meat can increase CRP and HbA1c.These associations will not be completely mediated by body mass index (BMI). MethodsUsing a cross-sectional design, we analyzed data collected from 3088 breast cancer survivors who enrolled in the Women’s Healthy Eating and Living (WHEL) Study and had provided four detailed 24-hour dietary recalls over a 3-week period along with a blood sample to validate dietary pattern and measure plasma CRP and HbA1c from washed red blood cells. Intakes of processed and unprocessed red meat were extracted from dietary recalls. CRP concentrations were measured using high-sensitivity electrochemiluminescence assay. HbA1C was measured using ion exchange high-performance liquid chromatography. ResultsWe found significant positive associations for both unprocessed and processed red meat with plasma CRP and HbA1c. In multivariable adjusted models, compared to women with the lowest quintile intakes of unprocessed red meat, women with highest quintile had a 19% increase of CRP and had an 11% increase of HbA1c after adjustment for BMI. Further adjustment for total vegetable intake did not materially change these associations. We observed similar patterns for processed red meat. The magnitudes of the associations of processed red meat with CRP and HbA1c were similar to that of unprocessed meat with CRP and HbA1c after adjustment of BMI. P-values for trends were less than 0.002 for all of these associations. ConclusionsCRP and HbA1c are strong predictors for breast cancer prognosis and development of comorbidities (e.g., diabetes). Although many studies examined the association of red meat with CRP and HbA1c in general healthy population, few studies were conducted among breast cancer survivors. Our results for the first time demonstrate that the positive associations between unprocessed and processed red meat consumption and inflammation and hyperglycemia are not fully mediated by BMI among breast cancer women. Funding SourcesSDSU start-up funds.

The comparison of ion exchange-high performance liquid chromatography (IE-HPLC) and capillary electrophoresis (CE) for HbA1C measurement

The comparison of ion exchange-high performance liquid chromatography (IE-HPLC) and capillary electrophoresis (CE) for HbA1C measurement

DIFFERENCE IN GLICATED HEMOGLOBIN LEVEL BETWEEN BORONATE AFFINITY METHOD AND ION EXCHANGE-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD IN TYPE 2 DIABETES MELLITUS

Background: Glycated Hb (HbA1c) test is needed to control glycemic in high prevalence type 2 diabetes mellitus (DM) patients. Hemoglobin fraction separated and chemical reaction are two main concepts in HbA1c test. Ion exchange-high performance liquid chromatography (HPLC) and boronate affinity use first concept. Ion exchange-HPLC is reference method in most of clinical laboratorium. Point of care testing (POCT) with boronate affinity method that has been standardized by international institution is available. The aim of this study was to compare boronate affinity POCT method and ion exchange-HPLC method.Method: This cross sectional study was conducted to 22 type 2 DM patients those fullfill inclusion and exclusion criteria in January 2017 to February 2018. Level of HbA1c was assayed with boronate affinity POCT and ion exchange-HPLC method. T-test was used to analyse data and no significance difference if p&gt;0.005Results: Subjects of this study are women (59.1%) more than men (40.9%) with age mean 59.23 years old (8.1). Uncontroled type 2 DM (77.3%) more than controled type 2 DM (22.7%).Mean of HbA1 level was 8.0% (1.7) in boronate affinity POCT and 8.3% (1.8) in ion exchange-HPLC. T-test showed no significance difference between those two HbA1C assay methods (p&gt;0.005).Conclusion: There was no difference HbA1c level between boronate affinity POCT method and ion exchange-HPLC method.

イオン交換高速液体クロマトグラフィ法においてHbA1c値が偽低値を示した異常ヘモグロビン，HbE-Saskatoonの1例

イオン交換高速液体クロマトグラフィ法においてHbA1c値が偽低値を示した異常ヘモグロビン，HbE-Saskatoonの1例

Genetic Markers Explain Differences in HbA1c Levels between African-American (AA) and Non-Hispanic White (NHW) Participants of the Diabetes Prevention Program (DPP)

HbA1c levels are higher in AA than NHW independent of glycemia. We investigated whether genetics could explain observed differences in HbA1c levels between AA and NHW DPP participants. We tested 1) genetic variants known to cause hemoglobinopathies; 2) a genetic risk score (GRS) based on 60 variants associated with HbA1c in the most recent genome-wide association meta-analysis; and 3) Principal Components (PC) factors that are generated by a statistical procedure that uses a linear transformation to convert a set of observations of correlated genetic markers measured across the genome (HumanCore Exome arrays + 1000 Genomes imputation) into a set of values mirroring genetic variation due to continental ancestry to capture substructure admixture. Of 2,658 eligible DPP participants, 537 (20%) self-identified as AA and 1,476 (56%) as NHW. HbA1c was measured with ion-exchange high-performance liquid chromatography (Biorad Variant). Despite comparable fasting and 2h-glucose levels, AA had higher HbA1c (mean±SD= 6.2±0.6%) compared with NHW (5.8±0.4%; P&amp;lt;0.001). In AA, the genetic variant causing sickle cell trait was associated with higher HbA1c (β (SE)= +0.44 (0.08)%-unit per risk allele; P=2.1x10-4). The GRS was associated with HbA1c in both AA (β= +0.017 (0.005); P=0.002) and NHW (β= +0.016 (0.002); P=5.4x10-11). Self-identified AA were distributed along the first PC axis, as expected in mixed ancestry populations. The first PC explained 60% of the 0.4 unit difference in HbA1c between AA and NHW, while the sickle cell variant explained 16%, and GRS explained 14%. In conclusion, genetic variants causing hemoglobinopathies or currently known to influence HbA1c explained a small proportion of HbA1c difference between AA and NHW. A larger proportion of the difference was associated with the first PC, suggesting that other yet unidentified genetic markers influence HbA1c in AA, in addition to non-genetic factors. Disclosure M. Hivert: None. C.A. Christophi: None. K.A. Jablonski: None. S. Edelstein: None. S.E. Kahn: Advisory Panel; Self; Boehringer Ingelheim GmbH, Elcelyx Therapeutics, Inc., Eli Lilly and Company, Intarcia Therapeutics, Inc., Janssen Research &amp; Development, Merck &amp; Co., Inc., Novo Nordisk A/S. S. Golden: None. S. Dagogo-Jack: None. K.J. Mather: Research Support; Self; Merck &amp; Co., Inc., Sanofi-Aventis, Novo Nordisk A/S, Abbott. Advisory Panel; Self; Merck &amp; Co., Inc.. J.A. Luchsinger: None. A. Caballero: None. E. Barrett-Connor: None. W.C. Knowler: None. J.C. Florez: Consultant; Self; Intarcia Therapeutics, Inc.. Consultant; Spouse/Partner; Santen. W.H. Herman: Other Relationship; Self; Merck Sharp &amp; Dohme Corp., Lexicon Pharmaceuticals, Inc.. Consultant; Self; Janssen Scientific Affairs, LLC.. Research Support; Spouse/Partner; Nestlé. Other Relationship; Self; American Diabetes Association. Advisory Panel; Self; National Committee for Quality Assurance (NCQA). D. Research Group: None.

Análise de limite de galactosamina em hexosaminas totais em amostras injetáveis de heparina sódica suína

Introduction: Research, one of the core areas of health surveillance, has its importance justified by its search for answers to various health problems. Heparin, a biological product with anticoagulant and antithrombotic properties, has been related to adverse events between the years 2007–2008. Because of that, the official compendiums updated the monograph for raw material. However, there is a lack of monographs that evaluate the final product. Objective: The goal of this study is to propose a physicochemical method of analysis of the limits of galactosamine in total hexosamine from the finished product of porcine sodium heparin. Method: We developed an analytical method from the ionexchange high performance liquid chromatography with amperometric detection, with the appropriate evaluations of the system suitability for posterior analysis of three samples of porcine sodium heparin previously submitted to the sample preparation protocol through the Micro Bio-Spin column. Results: The samples were compared to the solution of the system suitability and raw material of porcine sodium heparin. We could detect the presence of galactosamine in one of the three analyzed samples in lower amounts than the limit stipulated by the American pharmacopeia. Conclusions: We concluded that the aforementioned method is efficient for the analysis of the finished product and that is the reason why it will be suggested to the Brazilian pharmacopeia.

Interference of Thalassemias on Hemoglobin A1c Measurement by Ion-Exchange High-Performance Liquid Chromatography Method Tosoh HLC-723 G8

The presence of hemoglobinopathies could interfere with some assays for Hemoglobin A1c (HbA1c) measurement; therefore, the effect of thalassemia on ion-exchange high-performance liquid chromatography (IEHPLC) method Tosoh HLC-723 G8 (Tosoh G8) was evaluated. A total of 43 normal controls and 101 thalassemia patients were quantified by Premier Hb9210 and Tosoh G8 (variant-mode) systems. At the same time, 7 normal controls and 8 thalassemia patients were confirmed by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) reference method for verification. For normal controls, the HbA1c values of Tosoh G8 system (y) showed great correlation and agreement with those from Premier Hb9210 (x) (y = 0.9688x + 0.2151, r = 0.9951; mean difference 0.02 ± 0.30%), and no significant relative bias above 7% was observed; the HbA1c values obtained by Tosoh G8 were consistent with the IFCC targets (relative bias < ± 6%) in all of the samples. However, for thalassemia, the correlation between Tosoh G8 (y) and Premier Hb9210 (x) became relatively low (y = 0.8079x + 1.2897, r = 0.7780); the HbA1c values of 91.1% of the samples (92/101) obtained by Tosoh G8 were higher than those by Premier Hb9210 (mean difference 0.33 ± 0.48%) and a significant positive bias above 7% was noticed in 43.3% (45/101) thalassemia patients; when compared with the IFCC targets, the 87.5% (7/8) relative bias was > ± 6%. Thalassemia could directly affect the measurement of HbA1c using the IE-HPLC method Tosoh G8 and the clinical laboratorial staff should pay close attention.

Proteomic analysis of the venom of the predatory ant Pachycondyla striata (Hymenoptera: Formicidae).

The ants use their venom for predation, defense, and communication. The venom of these insects is rich in peptides and proteins, and compared with other animal venoms, ant venoms remain poorly explored. The objective of this study was to evaluate the protein content of the venom in the Ponerinae ant Pachycondyla striata. Venom samples were collected by manual gland reservoir dissection, and samples were submitted to two-dimensional gel electrophoresis and separation by ion-exchange and reverse-phase high-performance liquid chromatography followed by mass spectrometry using tanden matrix-assisted laser desorption/ionization with time-of-flight (MALDI-TOF/TOF) mass spectrometry and electrospray ionization-quadrupole with time-of-flight (ESI-Q/TOF) mass spectrometry for obtaining amino acid sequence. Spectra obtained were searched against the NCBInr and SwissProt database. Additional analysis was performed using PEAKS Studio 7.0 (Sequencing de novo). The venom of P. striata has a complex mixture of proteins from which 43 were identified. Within the identified proteins are classical venom proteins (phospholipase A, hyaluronidase, and aminopeptidase N), allergenic proteins (different venom allergens), and bioactive peptides (U10-ctenitoxin Pn1a). Venom allergens are among the most expressed proteins, suggesting that P. striata venom has high allergenic potential. This study discusses the possible functions of the proteins identified in the venom of P. striata.