Since the term proteomics was coined by Marc Wilkins in 1994, there has been an explosion in the number of articles reporting the use of the proteomics technique. As the layers of biological organization and their regulation increase, the complexity of living beings increases. Thus, we go from the genome to tissues, cells, cellular compartments, and phenotypes and the complexity of the tools used to study this complexity also increases. Unlike the genome study, in the case of the proteome, we have a more complex panorama. We have a spatial and temporal proteome. Proteomics helps to answer complex biological questions since proteins\' function depends on their molecular structure, subcellular localization, and posttranslational modifications. In this protocol, we describe a methodology to extract proteins using different methods, separating proteins by electrophoresis in double-dimensional gels and analyzing the gels using specialized software that allows obtaining information on the number and abundance of the proteins from the gels.

Purpose The objective of this research project was to estimate DNA damage in patients diagnosed with cervical cancer using the comet assay, establish a correlation between this quantification and the oxidative stress marker malondialdehyde (MDA; plasma MDA), and compare the resulting parameters between the cases and age-matched controls. Materials and methods This study included 49 cervical cancer cases and 49 age-matched controls to measure DNA damage parameters such as comet length, head diameter, percentage of DNA in the comet head, tail length, percentage of DNA in the comet tail, and oxidative stress marker (plasma MDA) using the thiobarbituric acid reactive substance (TBARS) enzyme-linked immunosorbent assay (ELISA) method. Results Comet metrics suggesting DNA damage, such as comet length, tail length, and percentage of DNA in the comet tail, were considerably higher in cervical cancer cases than in age-matched controls. The proportion of DNA in the comet head, representing undamaged/mild DNA damage, was significantly higher in age-matched controls than in cervical cancer patients. Plasma MDA and comet tail length were shown to have a positive correlation. Compared to the age-matched controls, those between the ages of 30 and 39, with a parity of two to four, who had a history of early age at first pregnancy and a positive family history of cervical cancer, had the highest level of DNA damage. Conclusion The elevated levels of comet parameters and their positive correlation with plasma MDA suggest that individuals diagnosed with cervical cancer have a higher degree of DNA damage compared to the control group. In conjunction with established methods like the PAP smear, this predictive test comprising comet assay and estimation of plasma MDA may be utilized to identify and assess the risk of cervical cancer in individuals aged 30-39 years, with a parity between two and four pregnancies and a prior history of early age at first pregnancy, accompanied by a positive family history of the disease.

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We present a 57-year-old woman with diabetes mellitus and no other known comorbidities. HbA1c measurement by high-performance liquid chromatography (HPLC) gave unquantified results and a supernumerary peak was detected on the chromatogram. A thorough exploration of the hemoglobin profile showed the presence of an unclassified variant. Alkaline pH capillary electrophoresis revealed the presence of an abnormal peak migrating at zone 11, comprising 40.1% of total hemoglobin. An abnormal band migrating between hemoglobin A and hemoglobin F was observed by acid gel electrophoresis. Sequencing of the β-globin gene confirmed the presence of a rare hemoglobin variant, hemoglobin J-Guantanamo (HBB:c.386C>A) in the heterozygous state, which was for the first time documented in Morocco. Through this report, we emphasize the importance of careful analysis of the HPLC chromatogram for the detection of possible hemoglobin variants in HbA1c measurement.

Serum protein electrophoresis (SPE) and immunofixation (IFE) assays are commonly used to diagnose and monitor patients with multiple myeloma (MM). Identifying analytical interferences in SPE and IFE caused by therapeutic monoclonal antibodies (tmAbs) can be challenging. Here we report the case of a 72-year-old male with a long history of relapsed immunoglobulin (Ig)G kappa MM. A follow-up SPE showed the original peak plus 2 additional cathode peaks. Immunofixation was ordered as a reflex test to investigate the new peaks that showed initial patient monoclonal IgG kappa in addition to 2 restricted bands of the IgG kappa type. Therapeutic monoclonal antibody interference was suspected and the patient\'s chart was reviewed. The patient was not on any antimyeloma monoclonal antibody therapy. However, preexposure prophylaxis therapeutic monoclonal antibodies tixagevimab plus cilgavimab (Evusheld) for severe acute SARS-CoV-2 was administered approximately 45 minutes before sample collection, which led to the identifiable spikes and correlated bands. After 2 days, the IgG kappa bands disappeared, confirming this therapy\'s effect on SPE and IFE. Therefore, clinical pathologists should be aware of when providers prescribe new monoclonal antibody therapy and become familiar with the position of commonly prescribed (tmAbs) therapies at their institutions.

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Restrictive cardiomyopathy secondary to cardiac amyloidosis is an underdiagnosed, but treatable, cause of heart failure involving an extracellular deposition of misfolded protein. Hereby, we report a case of a female patient with history of nephrotic syndrome for 1 year who subsequently presented with symptoms of heart failure. The findings on cardiac imaging supported the suspicion of cardiac amyloidosis. Further laboratory workup for amyloidosis was pursued along with endomyocardial biopsy which confirmed amyloidosis-AL type. Patient was started on chemotherapy. The case underscores the importance of a timely diagnosis with the help of symptomatology and imaging along with a multidisciplinary approach for patient care.

Multiple myeloma is characterized by the presence of M-protein (monoclonal) in blood or urine. These proteins are immunoglobulins which are produced by a clone of abnormally proliferating B-lymphocytes and/or plasma cells. To evaluate M-protein, serum protein electrophoresis (SPEP) is used where a single band, known as M-band is seen. This band is usually seen in the gamma globulin region. However, in rare entities like biclonal gammopathy, two M-bands appear simultaneously at different positions on SPEP which may be attributed to the clonal expansion of two different neoplastic cell lines. Here, we describe an atypical case of IgA-kappa multiple myeloma, where two M-bands (one in the beta region and one in the gamma globulin region) were found during SPEP. This simulated a picture of biclonal gammopathy. However the monoclonal nature of this M-protein was proved by performing immunofixation electrophoresis (IFE). Further, we put across images to explain how IFE helps in differentiating between apparent and true biclonality.

Urine protein electrophoresis is often required for diagnosis and monitoring of urological or renal diseases and lymphoid hemopathies. We here report an uncommon urine protein electrophoresis result. The test was performed using agarose gel electrophoresis and capillary electrophoresis. It was a monoclonal peak of unknown significance migrating with gammaglobulins. Scientific literature and the tests performed demonstrated that it was myoglobin. In fact, myoglobin (17 kDa) is freely filtered by the glomerulus and normally reabsorbed by the tubules. If tubule capacity for reabsorption is exceeded, its presence results in overcharging proteinuria. Myoglobinuria helped diagnose rhabdomyolysis in our patient. Thus, the analysis of unknown peaks, can provide information on symptoms but also underlying pathologies, which may be of clinical interest.

Multiple myeloma is a haematological cancer caused by malignant plasma cells in the bone marrow that can result in organ dysfunction and death. Recent novel treatments have contributed to improved survival rates, including monoclonal antibody therapies that target the CD38 protein on the surface of plasma cells. Anti-CD38 therapies are IgG kappa monoclonal antibodies that are given in doses high enough for the drug to be visible on serum protein electrophoresis as a small paraprotein. We present a case where isatuximab, the most recent anti-CD38 monoclonal antibody to be approved for treatment of myeloma, obscured the patient\'s paraprotein on gel immunofixation, so that complete remission could not be demonstrated. This was resolved using the isatuximab Hydrashift assay. The interference on gel immunofixation was unexpected because isatuximab migrated in a position distinct from the patient\'s paraprotein on capillary zone electrophoresis. We demonstrate the surprising finding that isatuximab migrates in a different position on gel electrophoresis compared to capillary zone electrophoresis. It is vital that laboratories are aware of the possible interference on electrophoresis from anti-CD38 monoclonal antibody therapies, and are able to recognise these drugs on protein electrophoresis. The difference in isatuximab\'s electrophoretic mobility on capillary and gel protein electrophoresis makes this particularly challenging. Laboratories should have a strategy for alternative analyses in the event that the drugs interfere with assessment of the patient\'s paraprotein.