Sensitive, High-Throughput, and Robust Trapping-Micro-LC-MS Strategy for the Quantification of Biomarkers and Antibody Biotherapeutics.

For LC-MS-based targeted quantification of biotherapeutics and biomarkers in clinical and pharmaceutical environments, high sensitivity, high throughput, and excellent robustness are all essential but remain challenging. For example, though nano-LC-MS has been employed to enhance analytical sensitivity, it falls short because of its low loading capacity, poor throughput, and low operational robustness. Furthermore, high chemical noise in protein bioanalysis typically limits the sensitivity. Here we describe a novel trapping-micro-LC-MS (T-µLC-MS) strategy for targeted protein bioanalysis, which achieves high sensitivity with exceptional robustness and high throughput. A rapid, high-capacity trapping of biological samples is followed by µLC-MS analysis; dynamic sample trapping and cleanup are performed using pH, column chemistry, and fluid mechanics separate from the µLC-MS analysis, enabling orthogonality, which contributes to the reduction of chemical noise and thus results in improved sensitivity. Typically, the selective-trapping and -delivery approach strategically removes >85% of the matrix peptides and detrimental components, markedly enhancing sensitivity, throughput, and operational robustness, and narrow-window-isolation selected-reaction monitoring further improves the signal-to-noise ratio. In addition, unique LC-hardware setups and flow approaches eliminate gradient shock and achieve effective peak compression, enabling highly sensitive analyses of plasma or tissue samples without band broadening. In this study, the quantification of 10 biotherapeutics and biomarkers in plasma and tissues was employed for method development. As observed, a significant sensitivity gain (up to 25-fold) compared with that of conventional LC-MS was achieved, although the average run time was only 8 min/sample. No appreciable peak deterioration or loss of sensitivity was observed after >1500 injections of tissue and plasma samples. The developed method enabled, for the first time, ultrasensitive LC-MS quantification of low levels of a monoclonal antibody and antigen in a tumor and cardiac troponin I in plasma after brief cardiac ischemia. This strategy is valuable when highly sensitive protein quantification in large sample sets is required, as is often the case in typical biomarker validation and pharmaceutical investigations of antibody therapeutics.

Adenosine Metabolism in COPD: A Study on Adenosine Levels, 5'-Nucleotidase, Adenosine Deaminase and Its Isoenzymes Activity in Serum, Lymphocytes and Erythrocytes.

Adenosine is a signaling molecule which is produced in high concentrations during airway inflammation. Airway inflammation is a characteristic feature of COPD. Therefore, the current study was designed to evaluate the changes in adenosine metabolism in COPD and correlate these changes with severity of the disease. The study was conducted on 50 healthy controls (25 healthy non-smokers and 25 healthy smokers) and 46 COPD patients (21 moderate, 15 severe and 10 very severe). The patients were sub-divided into moderate, severe and very severe categories as per the GOLD spirometric classification. Blood was collected from each subject and serum, lymphocytes and erythrocytes were separated. The adenosine levels and activities of 5'-nucleotidase, adenosine deaminase and its isoenzymes were assessed in serum, lymphocytes and erythrocytes. The data were analyzed statistically. A p value < 0.05 was considered as significant. In healthy smokers and COPD patients the adenosine levels increased. In COPD patients 5'-nucleotidase activity increased significantly in serum, lymphocytes and erythrocytes. The activities of ADA and isoenzymes decreased significantly in serum of healthy smokers and COPD patients, in lymphocytes and erythrocytes of very severe COPD patients and of ADA and ADA2 in lymphocytes and erythrocytes of moderate and severe COPD patients. The FEV1 (% of predicted) showed a significant negative correlation with adenosine levels and 5'-nucleotidase activity in serum, lymphocytes and erythrocytes and significant positive correlation with ADA and isoenzymes activity in serum and lymphocytes of COPD patients. We conclude that the adenosine metabolism changes in COPD. The adenosine levels and 5'-nucleotidase activity increase, and ADA activity decreases with severity of the disease.

Changes in protein profile of erythrocyte membrane in bronchial asthma.

OBJECTIVES: Erythrocyte membrane proteins reflect the prototype of multifunctional proteins of various erythroid and non-erythroid cells, which demonstrate various cellular functions. The protein profile of cells changes in various diseases. Therefore, the objective of this study was to understand the changes in protein profile of erythrocyte membranes in bronchial asthma. METHODS: The study included 20 patients of bronchial asthma and 20 healthy subjects. Erythrocytes were isolated from peripheral blood, membranes were prepared followed by the determination of protein contents, and protein profile was assessed using SDS-PAGE. RESULTS: In bronchial asthma, the protein contents of erythrocyte membranes in asthmatic patients were significantly higher (p < .005) than in healthy controls. Analysis of protein profile showed absence of the proteins, namely, band 4.2 and adducin subunit-II, and appearance of protein bands of molecular weights corresponding to galectin-3, glyceraldehyde 3-phosphate dehydrogenase, ß-actin, dematin, band 4.1, and adducin (subunit-I) in asthmatic patients when compared with healthy controls. CONCLUSIONS: In asthma, there are quantitative and qualitative changes in proteins of erythrocyte membranes. The absence of band 4.2 protein may cause impairment of the erythrocyte membrane integrity, and presence of galectin-3 may lead to the activation of various inflammatory cells. The altered protein profile may possibly lead to altered response of the inflammatory cells to the asthmogenic stimuli, which may be responsible for pathophysiology and manifestation of the symptoms of bronchial asthma.

Lipids of erythrocyte membranes of COPD patients: a quantitative and qualitative study.

Chronic obstructive pulmonary disease (COPD) is characterized by inflammation of lung parenchyma and pulmonary hypoxemia with a proven systemic component. Tobacco smoke is the most important risk factor and plasma membrane plays a major role in the disease pathology and progression. The properties of biological membranes are a function of their lipid composition. Any change in its composition may lead to the pathophysiology. In COPD research, erythrocytes are emerging as a new therapeutic venture, as their shape and properties change in the disease. Therefore we studied the lipid composition of the erythrocyte membranes of COPD patients. The study included 30 patients having COPD, 10 healthy smokers and 10 non-smokers. Erythrocytes were separated from peripheral blood and their membranes prepared, followed by estimation of proteins, cholesterol and phospholipids. Individual phospholipids were identified and separated by TLC and fatty acid composition determined by gas chromatography. The data were analyzed statistically and P < 0.05 was considered significant. Our results demonstrate that in very severe COPD, proteins decrease, whereas phospholipids and cholesterol contents increase significantly, which showed a consistent negative correlation with FEV1%. The fatty acid analysis showed preponderance towards saturated fatty acids mainly arachidic and behenic acid, suggesting a decrease in membrane fluidity or a closer packing of lipid rafts. We are the first to report about preponderance of saturated fatty acids in plasma membrane of erythrocytes of COPD patients which may decrease the membrane fluidity and possibly impair the functions of the plasma membrane in the disease.

Sphingomyelin metabolism in erythrocyte membrane in asthma.

BACKGROUND: Sphingomyelin (SM), a major lipid constituent of outer leaflet of plasma membranes, with cholesterol, constitutes microdomains, which are termed as lipid rafts. These rafts provide support to proteins, receptors, enzymes, and so on and organize and orient them to conduct cellular functions including transmembrane signaling to substances in external milieu. The SM contents are regulated by its metabolism, changes in which may affect the composition of lipid rafts and cell response to the triggers of asthma which may lead to the pathophysiology. For studying changes in membranes, erythrocytes, which contain lipid rafts, are considered to be the best cell type. Hence, this study was conducted on plasma membrane of erythrocytes of asthmatic patients. OBJECTIVE: The objective is to understand the changes in SM metabolism in asthma. METHODS: The study included 50 subjects (25 asthmatics and 25 healthy subjects). Erythrocytes were isolated from the peripheral blood and membrane prepared. This was followed by determination of total cholesterol, phospholipids, SM, and sphingomyelinase activity. P < .05 was considered significant. RESULTS AND CONCLUSIONS: In asthmatics, there was a significant decrease in cholesterol contents (p < .05), decrease in total phospholipid contents (p < .005), increase in SM (p < .01), decrease in cholesterol: SM ratio (p < .001) and increase in sphingomyelinase activity (p < .001) in erythrocyte membranes. We conclude that in asthma, the increase in SM contents is associated with increased sphingomyelinase activity which shows an imbalance in SM metabolism, directed toward its accumulation. The ratio of cholesterol to SM, critical for maintenance of lipid rafts, was significantly lower in asthmatics. This indicates changes in structure of lipid rafts which may lead to the pathophysiology and development of asthma. Regulation of SM metabolism may help in disease regulation and its control.

Beneficial effects of N-acetylcysteine on protease-antiprotease balance in attenuating bleomycin-induced pulmonary fibrosis in rats.

OBJECTIVES: The role of N-acetylcysteine (NAC) as an anti-oxidant in attenuating bleomycin-induced pulmonary fibrosis has been reported. However, its effect on parenchymal remodeling via regulating the protease-antiprotease balance is not fully defined. Therefore, the present study was designed to explore the possible role of matrix metalloproteinases (MMP), tissue inhibitors of metalloproteinases (TIMP) and transforming growth factor-ß1 (TGF-ß1) pathway and their modulation by NAC in attenuating bleomycin-induced pulmonary fibrosis in rats. MATERIALS AND METHODS: Bleomycin sulphate (7 units/kg) was instilled inside the trachea to induce pulmonary fibrosis. The time course of TGF-ß1, MMP-9, TIMP-1,3 mRNA and protein expression, TGF-ß1 and hydroxyproline levels were evaluated on days 7, 14, and 28. NAC (0.3 mmol/kg and 3 mmol/kg) was administered in bleomycin-instilled animals. RESULTS: NAC treatment significantly attenuated bleomycin-induced histopathological changes by decreasing interstitial inflammation and reducing the deposition of extracellular matrix proteins such as collagen. Moreover, it increased the mRNA and protein expression of MMP-9 and decreased the expression of TIMP-1,3 in alveolar epithelial cells (AECs), interstitial macrophages and inflammatory cells. Indeed, there was decrease in the MMP-9/TIMP ratio in bleomycin-instilled rats, which increased with NAC treatment. Moreover, NAC attenuated bleomycin-induced increased expression of TGF-ß1 and total lung collagen levels. CONCLUSION: NAC attenuates bleomycin-induced pulmonary fibrosis by normalizing the protease-antiprotease balance and favoring the degradation of collegen to reduce fibrosis.

Protective role of Cassia auriculata leaf extract on hyperglycemia-induced oxidative stress and its safety evaluation.

Cassia auriculata L. (Caesalpiniaceae) is widely used from the ancient period to treat diabetes mellitus. In the present study, the antioxidant activity of C. auriculata aqueous leaf extract (CLEt) was evaluated in streptozotocin-induced mild diabetic (MD) and severe diabetic (SD) rats. A short-term toxicity assessment was also conducted in healthy rats to examine toxic effects of the extract. Oral administration of CLEt to MD and SD rats (100, 200 and 400 mg/kg body weight per day for a period of 21 days) produced significant fall in fasting blood glucose (FBG) in a dose-dependent manner. Treatment with the extract (400 mg/kg) showed significant reduction in serum levels of thiobarbituric acid reactive substances (TBARS) and oxidized low-density lipoprotein (OxLDL) in both MD and SD rats. The antioxidant defense system was also found to be improved in CLEt-treated (400 mg/kg) MD and SD rats, as revealed by significant increase in activities of erythrocyte's antioxidant enzymes, i.e., superoxide dismutase (SOD) and catalase (CAT) with a concomitant elevation in erythrocyte's reduced glutathione (GSH) content. Moreover, there were no toxic signs in rats treated with high doses of the extract (1000 and 2000 mg/kg body weight per day for 21 days). Blood glucose, hepatic and renal function parameters in these rats were found within normal limits. Phytochemical screening of CLEt revealed the presence of alkaloids, flavonoids, saponins, tannins and cardiac glycosides with antihyperglycemic and antioxidant properties. This study suggests that CLEt possesses potent antioxidant activity along with antihyperglycemic potential, hence protective against diabetic complications.

Serum interleukin-1beta as a marker for differentiation of asthma and chronic obstructive pulmonary disease.

Asthma and chronic obstructive pulmonary disease (COPD) are diseases of airway inflammation with clinical and physiological similarities, making their differentiation difficult. Airway inflammatory changes are associated with systemic changes. However, no serum marker is known for their differentiation. Therefore, serum interleukin (IL)-1beta levels were determined. Out of a total of 1023 patients screened, we included in the study ten patients each with atopic asthma, non-atopic asthma and COPD and ten healthy subjects. Skin prick tests with 14 inhalant allergens were performed on each patient. Blood was collected in the symptomatic and asymptomatic phases of the diseases and serum IL-1beta and IgE levels were determined. Our results showed that in the symptomatic phase in asthmatics, serum IL-1beta levels were higher (P<0.05) than in patients with COPD. Serum IgE levels were higher (P<0.05) in atopic asthmatics than in non-atopic asthmatics and in COPD patients. We conclude that serum IL-1beta level determination during the symptomatic phase of the diseases may help to differentiate asthmatics from patients with COPD. Serum IgE levels may differentiate atopic asthmatics from non-atopic asthmatics and COPD patients.

De novo ABCD1 gene mutation in an Indian patient with adrenoleukodystrophy.

A large number of ABCD1 gene mutations have been reported all over the world, but not previously in India. We report on the first known patient with childhood cerebral adrenoleukodystrophy and a de novo 3' splice-site mutation in this gene. Magnetic resonance imaging of the brain revealed large, confluent, hyperintense areas in the bilateral cerebral white matter, predominantly parieto-occipital, with extensions into posterior regions that led to breakdown of the blood-brain barrier. An increased level of very long chain fatty acids was also consistent with the biochemical defect for adrenoleukodystrophy. Sequencing of the ABCD1 gene of this patient identified a 3' splice-site mutation in the intervening sequence 4 (-2a > g). We did not find any mutation in the gene of the proband's mother, which confirms its de novo occurrence.

An Improved 2-Dimensional Gel Electrophoresis Method for Resolving Human Erythrocyte Membrane Proteins.

The 2-dimensional gel electrophoresis (2-DE) technique is widely used for the analysis of complex protein mixtures extracted from biological samples. It is one of the most commonly used analytical techniques in proteomics to study qualitative and quantitative protein changes between different states of a cell or an organism (eg, healthy and diseased), conditionally expressed proteins, posttranslational modifications, and so on. The 2-DE technique is used for its unparalleled ability to separate thousands of proteins simultaneously. The resolution of the proteins by 2-DE largely depends on the quality of sample prepared during protein extraction which increases results in terms of reproducibility and minimizes protein modifications that may result in artifactual spots on 2-DE gels. The buffer used for the extraction and solubilization of proteins influences the quality and reproducibility of the resolution of proteins on 2-DE gel. The purification by cleanup kit is another powerful process to prevent horizontal streaking which occurs during isoelectric focusing due to the presence of contaminants such as salts, lipids, nucleic acids, and detergents. Erythrocyte membrane proteins serve as prototypes for multifunctional proteins in various erythroid and nonerythroid cells. In this study, we therefore optimized the selected major conditions of 2-DE for resolving various proteins of human erythrocyte membrane. The modification included the optimization of conditions for sample preparation, cleanup of protein sample, isoelectric focusing, equilibration, and storage of immobilized pH gradient strips, which were further carefully examined to achieve optimum conditions for improving the quality of protein spots on 2-DE gels. The present improved 2-DE analysis method enabled better detection of protein spots with higher quality and reproducibility. Therefore, the conditions established in this study may be used for the 2-DE analysis of erythrocyte membrane proteins for different diseases, which may help to identify the proteins that may serve as markers for diagnostics as well as targets for development of new therapeutic potential.

Bioanalysis of alectinib and metabolite M4 in human plasma, cross-validation and impact on PK assessment.

BACKGROUND: Alectinib is a novel anaplastic lymphoma kinase (ALK) inhibitor for treatment of patients with ALK-positive non-small-cell lung cancer who have progressed on or are intolerant to crizotinib. To support clinical development, concentrations of alectinib and metabolite M4 were determined in plasma from patients and healthy subjects. METHODS: LC-MS/MS methods were developed and validated in two different laboratories: Chugai used separate assays for alectinib and M4 in a pivotal Phase I/II study while Roche established a simultaneous assay for both analytes for another pivotal study and all other studies. CONCLUSION: Cross-validation assessment revealed a bias between the two bioanalytical laboratories, which was confirmed with the clinical PK data between both pivotal studies using the different bioanalytical methods.

Phospholipid metabolism and protein kinase C mediated protein phosphorylation in dietary protein deficiency in rat lung.

Nutritional deprivation of proteins decreases the protein kinase C (PKC) activity in rat lung. The activity of (PKC) is influenced by lipid metabolism. Changes in PKC activity may influence phosphorylation of its substrate proteins in the tissues. Therefore, alterations in phospholipid metabolism and PKC mediated protein phosphorylation in dietary protein deficiency in rat lung were envisaged. The study was conducted on rats fed on three different types of diet viz., casein (20% protein), deficient (4% protein, rice flour as source of protein) and supplemented (deficient diet supplemented with L-lysine and DL-threoning). Feeding of protein deficient diet caused reduction in incorporation of [3H] myo-inositol in the total phosphoinositides in lungs and an increase in total inositol phosphate pool. There was a significant reduction in the contents and turnover rate of phosphatidyl inositol and phosphatidyl inositol monophosphate. Supplementation of diet with L-lysine and DL-threonine had a reversing effect on total pool of phosphoinositides and, the metabolism of phosphatidyl inositol bisphosphate and phosphatidyl inositol. In phosphatidyl choline metabolism, the dietary protein deficiency led to a decrease in incorporation of [14C-methyl] choline-chloride in total phospholipids. In contrast, its incorporation increased in phosphatidyl choline pool. The contents of phosphatidyl choline and residue, incorporation of [14C-methyl] choline-chloride in them and their turnover rate also increased. Supplementation of diet had a reversal effect on most of these parameters. Phosphorylation of proteins of 84, 47, 35 and 16 kDa was identified to be mediated by PKC. In dietary protein deficiency, phosphorylation of all these proteins, except that of 47 kDa, increased. Supplementation of diet reversed the pattern except that of 84 kDa. The findings suggest that changes in phospholipid metabolism in dietary protein deficiency may effect the activity of PKC thereby influencing the phosphorylation of its substrate proteins and hence associated functions that may lead to pathophysiology of lung.

Buttock necrosis after uterine artery embolization.

BACKGROUND: Uterine artery embolization is an increasingly popular alternative to hysterectomy or myomectomy for treatment of symptomatic uterine leiomyomata. CASE: A woman with a symptomatic uterine fibroid developed 2 areas of full-thickness necrosis on her right buttock following uterine artery embolization. After surgical debridement, healing occurred over 14 weeks. CONCLUSION: Buttock necrosis is a possible complication of nontarget embolization during uterine artery embolization.

Aortic arch origin of the left external carotid artery and type II proatlantal fetal anastomosis.

This case report demonstrates a rare vascular pattern of a left external carotid artery (ECA) that arises directly from the aortic arch (AA), along with a type II proatlantal-vertebral artery anastomosis. Our research shows no report of an ECA arising from the AA. This, in association with a type II proatlantal anastomosis, is interesting because of its apparent rarity.

2014 White Paper on recent issues in bioanalysis: a full immersion in bioanalysis (Part 3 - LBA and immunogenicity).

The 2014 8th Workshop on Recent Issues in Bioanalysis (8th WRIB), a 5-day full immersion in the evolving field of bioanalysis, took place in Universal City, California, USA. Close to 500 professionals from pharmaceutical and biopharmaceutical companies, contract research organizations and regulatory agencies worldwide convened to share, review, discuss and agree on approaches to address current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches and immunogenicity. From the prolific discussions held during the workshop, specific recommendations are presented in this 2014 White Paper. As with the previous years' editions, this paper acts as a practical tool to help the bioanalytical community continue advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2014 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 3) covers the recommendations for Large molecules bioanalysis using LBA and Immunogenicity. Part 1 (Small molecules bioanalysis using LCMS) and Part 2 (Hybrid LBA/LCMS, Electronic Laboratory Notebook and Regulatory Agencies' Input) were published in the Bioanalysis issues 6(22) and 6(23), respectively.

2014 White Paper on recent issues in bioanalysis: a full immersion in bioanalysis (Part 1--small molecules by LCMS).

The 2014 8th Workshop on Recent Issues in Bioanalysis (8th WRIB), a 5-day full immersion in the evolving field of bioanalysis, took place in Universal City, California, USA. Close to 500 professionals from pharmaceutical and biopharmaceutical companies, contract research organizations and regulatory agencies worldwide convened to share, review, discuss and agree on approaches to address current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches and immunogenicity. From the prolific discussions held during the workshop, specific recommendations are presented in this 2014 White Paper. As with the previous years' editions, this paper acts as a practical tool to help the bioanalytical community continue advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2014 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 1) covers the recommendations for small molecule bioanalysis using LCMS. Part 2 (Hybrid LBA/LCMS, Electronic Laboratory Notebook and Regulatory Agencies' input) and Part 3 (Large molecules bioanalysis using LBA and Immunogenicity) will be published in the upcoming issues of Bioanalysis.

2014 White Paper on recent issues in bioanalysis: a full immersion in bioanalysis (Part 2 - hybrid LBA/LCMS, ELN & regulatory agencies' input).

The 2014 8th Workshop on Recent Issues in Bioanalysis (8th WRIB), a 5-day full immersion in the evolving field of bioanalysis, took place in Universal City, California, USA. Close to 500 professionals from pharmaceutical and biopharmaceutical companies, contract research organizations and regulatory agencies worldwide convened to share, review, discuss and agree on approaches to address current issues of interest in bioanalysis. The topics covered included both small and large molecules, and involved LCMS, hybrid LBA/LCMS, LBA approaches and immunogenicity. From the prolific discussions held during the workshop, specific recommendations are presented in this 2014 White Paper. As with the previous years' editions, this paper acts as a practical tool to help the bioanalytical community continue advances in scientific excellence, improved quality and better regulatory compliance. Due to its length, the 2014 edition of this comprehensive White Paper has been divided into three parts for editorial reasons. This publication (Part 2) covers the recommendations for Hybrid LBA/LCMS, Electronic Laboratory Notebook and Regulatory Agencies' Input. Part 1 (Small molecules bioanalysis using LCMS) was published in the Bioanalysis issue 6(22) and Part 3 (Large molecules bioanalysis using LBA and Immunogenicity) will be published in the Bioanalysis issue 6(24).

2013 White Paper on recent issues in bioanalysis: 'hybrid'--the best of LBA and LCMS.

The 2013 7th Workshop on Recent Issues in Bioanalysis was held in Long Beach, California, USA, where close to 500 professionals from pharmaceutical and biopharmaceutical companies, CROs and regulatory agencies convened to discuss current topics of interest in bioanalysis. These 'hot' topics, which covered both small and large molecules, were the starting point for fruitful exchanges of knowledge, and sharing of ideas among speakers, panelists and attendees. The discussions led to specific recommendations pertinent to bioanalytical science. Such as the previous editions, this 2013 White Paper addresses important bioanalytical issues and provides practical answers to the topics presented, discussed and agreed upon by the global bioanalytical community attending the 7th Workshop on Recent Issues in Bioanalysis.

2012 white paper on recent issues in bioanalysis and alignment of multiple guidelines.

Over 400 professionals representing pharmaceutical companies, CROs, and multiple regulatory agencies participated in the 6th Workshop on Recent Issues in Bioanalysis (WRIB). Like the previous sessions, this event was in the format of a practical, focused, highly interactive and informative workshop aiming for high-quality, improved regulatory compliance and scientific excellence. Numerous 'hot' topics in bioanalysis of both small and large molecules were shared and discussed, leading to consensus and recommendations among panelists and attendees representing the bioanalytical community. The major outcome of this year's workshop was the noticeable alignment of multiple bioanalytical guidance/guidelines from different regulatory agencies. This represents a concrete step forward in the global harmonization of bioanalytical activities. The present 2012 White Paper acts as a practical and useful reference document that provides key information and solutions on several topics and issues in the constantly evolving world of bioanalysis.