| 711. |
- Chroni, Elisabeth, et al.
(författare)
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Usefulness of assessing repeater F-waves in routine studies
- 2012
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 45:4, s. 477-485
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Repeater F-waves are sometimes seen in routine studies.METHODS: We retrospectively reviewed the clinical significance of repeater F-waves in median, ulnar, and fibular nerve recordings in 50 healthy subjects and groups of 50 patients each with diabetic polyneuropathy, amyotrophic lateral sclerosis, carpal tunnel syndrome, ulnar mononeuropathy, and L5 root lesion. The number of identical F-waves and their repetitions in samples of 20 stimuli were estimated.RESULTS: Repeater F-waves occurred significantly more frequently in all nerves and patient groups than in healthy individuals. Their persistence was negatively correlated with that of non-repeater F-waves.CONCLUSIONS: Based on the presented material and recording condition it appears that repeater F-waves differentiate between health and disease but not between different types of pathology of motor neurons or their axons. Even in routinely recorded samples of 20 traces, the index of repeater all F-waves could be used as a sign of nerve pathology.
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| 712. |
- Claesson, Kjersti, et al.
(författare)
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Counting the platelets: a robust and sensitive quantification method for thrombus formation
- 2016
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Ingår i: Thrombosis and Haemostasis. - : SCHATTAUER GMBH-VERLAG MEDIZIN NATURWISSENSCHAFTEN. - 0340-6245 .- 2567-689X. ; 115:6, s. 1178-1190
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Tidskriftsartikel (refereegranskat)abstract
- Flow chambers are common tools used for studying thrombus formation in vitro. However, the use of such devices is not standardised and there is a large diversity among the flow chamber systems currently used, and also in the methods used for quantifying the thrombus development. It was the study objective to evaluate a new method for analysis and quantification of platelet thrombus formation that can facilitate comparison of results between research groups. Whole blood was drawn over a collagen patch in commercial Ibid or in-house constructed PDMS flow chambers. Five percent of the platelets were fluorescently labelled and z-stack time-lapse images were captured during thrombus formation. Images were processed in a Python script in which the number of platelets and their respective x-, y- and z-positions were obtained. For comparison with existing methods the platelets were also labelled and quantified using fluorescence intensity and thrombus volume estimations by confocal microscopy. The presented method was found less sensitive to microscope and image adjustments and provides more details on thrombus development dynamics than the methods for measuring fluorescence intensity and thrombus volume estimation. The platelet count method produced comparable results with commercial and PDMS flow chambers, and could also obtain information regarding the stability of each detected platelet in the thrombus. In conclusion, quantification of thrombus formation by platelet count is a sensitive and robust method that enables measurement of platelet accumulation and platelet stability in an absolute scale that could be used for comparisons between research groups.
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| 713. |
- Clausen, Frederik Banch, et al.
(författare)
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External quality assessment of noninvasive fetal RHD genotyping
- 2020
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Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 115:5, s. 466-471
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Tidskriftsartikel (refereegranskat)abstract
- Background and objectives: Fetal RHD genotyping of cell-free maternal plasma DNA from RhD negative pregnant women can be used to guide targeted antenatal and postnatal anti-D prophylaxis for the prevention of RhD immunization. To assure the quality of clinical testing, we conducted an external quality assessment workshop with the participation of 31 laboratories. Materials and methods: Aliquots of pooled maternal plasma from gestational week 25 were sent to each laboratory. One sample was fetal RHD positive, and a second sample was fetal RHD negative. A reporting scheme was supplied for data collection, including questions regarding the methodological setup, results and clinical recommendations. The samples were tested blindly. Results: Different methodological approaches were used; 29 laboratories used qPCR and two laboratories used ddPCR, employing a total of eight different combinations of RHD exon targets. Fetal RHD genotyping was performed with no false-negative and no false-positive results. One inconclusive result was reported for the RHD positive sample. All clinical conclusions were satisfactory. Conclusion: This external quality assessment workshop demonstrates that despite the different approaches taken to perform the clinical assays, fetal RHD genotyping is a reliable laboratory assay to guide targeted use of Rh prophylaxis in a clinical setting.
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| 714. |
- Coppieters, Ken T., et al.
(författare)
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Persistent glucose transporter expression on pancreatic beta cells from longstanding type 1 diabetic individuals
- 2011
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Ingår i: Diabetes/Metabolism Research Reviews. - : Wiley. - 1520-7552 .- 1520-7560. ; 27:8, s. 746-754
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Recent reports have established the notion that many patients with longstanding type 1 diabetes (T1D) possess a remnant population of insulin-producing beta cells. It remains questionable, however, whether these surviving cells can physiologically sense and respond to glucose stimuli.METHODS: Frozen pancreatic sections from non-diabetic donors (n=8), type 2 diabetic patients (n=4), islet autoantibody-positive non-diabetic patients (n=3), type 1 diabetic patients (n=10) and one case of gestational diabetes were obtained via the network for Pancreatic Organ Donors. All longstanding T1D samples were selected based on the detection of insulin-producing beta cells in the pancreas by immunohistochemistry. RNA was isolated from all sections followed by cDNA preparation and quantitative real-time polymerase chain reaction for insulin, glucose transporter 1 (GLUT1), GLUT2 and GLUT3. Finally, immunofluorescent staining was performed on consecutive sections for all four of these markers and a comparison was made between the expression of GLUT2 in humans versus NOD mice.RESULTS: In contrast to islets from the most widely used T1D model, the NOD mouse, human islets predominantly express GLUT1 and, to a much lesser extent, GLUT3 on their surface instead of GLUT2. Relative expression levels of these receptors do not significantly change in the context of the various (pre-)diabetic conditions studied. Moreover, in both species preservation of GLUT expression was observed even under conditions of substantial leucocyte infiltration or decades of T1D duration.CONCLUSIONS: These data suggest that despite being subjected to multiple years of physiological stress, the remaining beta-cell population in longstanding T1D patients retains a capacity to sense glucose via its GLUTs.
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| 715. |
- Cui, Yanhua, et al.
(författare)
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Prior exposure to alkylating agents negatively impacts testicular organoid formation in cells obtained from childhood cancer patients
- 2024
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Ingår i: HUMAN REPRODUCTION OPEN. - : OXFORD UNIV PRESS. - 2399-3529. ; 2024:3
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Tidskriftsartikel (refereegranskat)abstract
- STUDY QUESTION Can human pre- and peri-pubertal testicular cells obtained from childhood cancer patients, previously treated with chemotherapy, form testicular organoids (TOs)?SUMMARY ANSWER Organoid formation from testicular tissue collected from childhood cancer patients positively correlates with SRY-Box transcription factor 9 (SOX9) expression in Sertoli cells, which in turn negatively correlates with previous exposure to alkylating chemotherapy.WHAT IS KNOWN ALREADY Pre- and peri-pubertal boys exposed to highly gonadotoxic therapies can only safeguard their fertility potential through testicular tissue cryopreservation. Today, there is no established clinical tool to restore fertility using these testicular samples. Organoids hold promise in providing fundamental early insights in creating such platforms. However, the generation of TOs that closely resemble the innate testis, to enable a thorough monitoring of the necessary steps for germ cell differentiation and somatic functionalities, remains a challenge.STUDY DESIGN, SIZE, DURATION We used a Matrigel-based three-layer gradient culture system to generate human TOs and to reveal whether chemotherapy exposure affects TO formation capacity and the functionality of pre- and peri-pubertal testicular somatic cells. Testicular cells of 11 boys (aged 7.7 +/- 4.1 (mean +/- SD) years) were assessed for TO formation in relation to previous chemotherapy exposure and SOX9 expression in histological sections of paraffin-embedded testicular tissue samples collected on the day of biopsy and compared with testicular tissue samples obtained from 28 consecutive patients (aged 6.9 +/- 3.8 (mean +/- SD) years). All 39 patients were part of the fertility preservation project NORDFERTIL; an additional 10 samples (from boys aged 5.5 +/- 3.5 (mean +/- SD) years, without an underlying pathology) in an internal biobank collection were used as controls.PARTICIPANTS/MATERIALS, SETTING, METHODS We obtained 49 testicular tissue samples from boys aged 0.8-13.4 years. Fresh samples (n = 11) were dissociated into single-cell suspensions and applied to a three-layer gradient culture system for organoid formation. Histological sections of another 28 samples obtained as part of the fertility preservation project NORDFERTIL, and 10 samples from a sample collection of a pathology biobank were used to evaluate the effects of prior exposure to alkylating agents on testicular samples. Testicular organoid formation was defined based on morphological features, such as compartmentalized structures showing cord formation, and protein expression of testicular cell-specific markers for germ and somatic cells was evaluated via immunohistochemical staining. Hormone secretion was analysed by specific enzyme-linked immunosorbent assays for testosterone and anti-M & uuml;llerian hormone (AMH) production.MAIN RESULTS AND THE ROLE OF CHANCE Our results revealed that 4 out of 11 prepubertal testicular samples formed TOs that showed compartmentalized cord-like structures surrounded by interstitial-like areas and increasing levels of both testosterone as well as AMH over a 7-day culture period. We observed that SOX9 expression was correlated positively with TO formation. Moreover, exposure to alkylating agents before biopsy was inversely correlated with SOX9 expression (P = 0.006).LARGE SCALE DATA N/A.LIMITATIONS, REASONS FOR CAUTION Due to the limited amount of material available, only 11 out of the 39 pre- and peri-pubertal testicular tissue samples could be used for the organoid formation experiments. The testicular tissue samples obtained from a sample collection of the internal biobank of Department of Pathology, Karolinska University Hospital were considered normal and included in the study if no testicular pathology was reported. However, detailed information regarding previous medical treatments and/or testicular volumes of the patients included in this biobank was not available.WIDER IMPLICATIONS OF THE FINDINGS Our observations suggest that SOX9 expression may serve as a putative indicator of TO formation, indicating a critical role of Sertoli cells in promoting organoid formation, seminiferous tubule integrity, and testicular function in pre- and peri-pubertal testicular tissue.STUDY FUNDING/COMPETING INTEREST(S) This study was supported by grants from the Swedish Childhood Cancer Foundation (PR2019-0123; PR2022-0115; TJ2020-0023) (J.-B.S.), Finnish Cancer Society (K.J.), Finnish Foundation for Paediatric Research (K.J.), Swedish Research Council (2018-03094; 2021-02107) (J.-B.S.), and Birgitta and Carl-Axel Rydbeck's Research Grant for Paediatric Research (2020-00348; 2020-00335; 2021-00073; 2022-00317) (J.-B.S. and K.J.). Y.C. and Y.Y. received a scholarship from the Chinese Scholarship Council. J.P.A-L. was supported by a Starting Grant in Medicine and Health (2022-01467) from the Swedish Research Council. R.T.M. was supported by a UKRI Future Leaders Fellowship (MR/S017151/1). The MRC Centre for Reproductive Health was supported by an MRC Centre Grant (MR/N022556/1). The authors declare no competing interests.
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| 716. |
- Dahlbom, Ingrid, et al.
(författare)
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Protein A and protein G ELISA for the detection of IgG autoantibodies against tissue transglutaminase in childhood celiac disease
- 2008
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981 .- 1873-3492. ; 395:1-2, s. 72-6
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate if the detection of celiac disease (CD) in children was improved by using alternative conjugates for assessment of tissue transglutaminase (tTG) autoantibodies. Methods: Serum samples from 108 biopsy confirmed CD children and 42 control subjects were investigated for the presence of autoantibodies with tTG coated microplates using protein A (PA), protein G (PG), anti-IgG, or anti-IgA as conjugates. Results: Of the 108 CD children, 86 (80%) were IgG-tTG positive, 91 (84%) were positive with the PA-conjugate, 94 (87%) were positive with the PG-conjugate, and 103 (95%) were IgA-tTG positive. Among the 42 controls. 4 (10%) were IgG-tTG positive, 5 (12%) were positive with both the PA- and PG conjugates. whereas 3 (7%) were IgA-tTG positive. Compared with IgG-tTG the concordance was 93% for PA and 95% for PG, with a positive correlation between antibody levels (r=0.967 and r=0.975. p< ;0.0001). All but one CD child were found positive by combining IgG-tTG and IgA-tTG detection. Conclusions: The sensitivity of IgG-tTG detection with ELISA increased by protein A or protein G conjugates, whereas the specificity was reduced as compared with anti-IgG conjugate. The combined measurement of IgA-tTG and IgG-tTG still seems to be the optimal procedure when screening children for CD.
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| 717. |
- de Alwis, Roger
(författare)
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Molecular Markers and Hypoxia in Renal Cell Carcinoma
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Renal cell carcinomas (RCCs) are a group of tumours that arise from the nephron within the kidney. They are characterised by an indolent growth pattern and do not display overt clinical symptoms in patients with early to locally advanced tumours. Furthermore, the global average age of a RCC patient at diagnosis is 75 and they usually present with co-morbidities that may render invasive surgical/biopsy approaches risky. The most prevalent form of RCC is the clear cell RCC (ccRCC) subtype that displays pseudohypoxic activation of the two transcription factors HIF- 1α and HIF-2α as the result of a non-functional pVHL protein. Although the general influence of these two transcription factors has been deciphered, the full extent of the tumour-promoting activities of HIF-2α via its target genes have not been elucidated. Given these limitations in the clinical management of RCC and understanding of its biology, we set out to address these issues through the papers included in this thesis.In our first paper we aimed to decipher HIF-2α specific target genes operating in normal renal proximal tubule epithelial cells as well as ccRCC tumour cells. We pharmacologically emulated the loss of functional pVHL in renal proximal tubule cells whilst inhibiting HIF-2α transcriptional activity. Subsequent RNA-sequencing revealed potentially HIF-2α specific genes of which we selected SEMA5B, where its protein expression pattern matched our RNA-sequencing findings. We verified the HIF-2α regulatory specificity to SEMA5B in ccRCC cell lines, with other lines of evidence definitively demonstrating that HIF-2α but not HIF-1α specifically regulates the expression of SEMA5B in renal proximal tubule and ccRCC cells. Therefore, SEMA5B may have important role(s) in the context of ccRCC tumour vascularity and microenvironment.With papers two and three, we sought to address issues in RCC prognostication and detection. In paper two, we analysed transcription factor network and regulon activity in RCC subtypes using publicly available datasets. Using this analysis, we identified NFIA, a transcription factor that had similar regulon activity to HNF4A, a well characterised transcription factor in RCC. Based on this data, we examined the relationship between RNA expression of our selected transcription factor NFIA and TCGA-based RCC patient clinicopathological factors such as grade, stage andcancer-specific survival. We assessed the protein expression of NFIA and HNF4A in a large tissue-microarray consisting of ccRCC and papillary RCC (pRCC) tumours and found that NFIA expression can independently predict CSS in ccRCC patients. Molecular markers for the prognostication of RCC patients are not currently used in the clinic and we hope that our work can contribute towards their eventual implementation.In paper three we developed a workflow to enrich, detect and subtype RCC tumour cells from whole blood. Given the poor performance of EpCAM based circulating tumour cell enrichment methods in RCC, we utilised a size-based isolation platform. We demonstrated that RCC tumour cells are suitable for this approach and showed that our methodology can isolate down to one spiked-in tumour cell from whole blood. Furthermore, through differential gene expression analyses between the three RCC subtypes, we identified transcriptomic markers that can be used to detect pRCC and ccRCC tumour cells from whole blood. This paper lays out a large extent of the methodology and fine-tuning required to isolate and detect RCC tumour cells from whole blood and may provide an additional way to monitor RCC patients in adjuvant and/or neoadjuvant settings.
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| 718. |
- De Leoz, M. L. A., et al.
(författare)
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NIST Interlaboratory Study on Glycosylation Analysis of Monoclonal Antibodies: Comparison of Results from Diverse Analytical Methods
- 2020
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476. ; 19:1, s. 11-30
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Tidskriftsartikel (refereegranskat)abstract
- A broad-based interlaboratory study of glycosylation profiles of a reference and modified IgG antibody involving 103 reports from 76 laboratories. Glycosylation is a topic of intense current interest in the development of biopharmaceuticals because it is related to drug safety and efficacy. This work describes results of an interlaboratory study on the glycosylation of the Primary Sample (PS) of NISTmAb, a monoclonal antibody reference material. Seventy-six laboratories from industry, university, research, government, and hospital sectors in Europe, North America, Asia, and Australia submitted a total of 103 reports on glycan distributions. The principal objective of this study was to report and compare results for the full range of analytical methods presently used in the glycosylation analysis of mAbs. Therefore, participation was unrestricted, with laboratories choosing their own measurement techniques. Protein glycosylation was determined in various ways, including at the level of intact mAb, protein fragments, glycopeptides, or released glycans, using a wide variety of methods for derivatization, separation, identification, and quantification. Consequently, the diversity of results was enormous, with the number of glycan compositions identified by each laboratory ranging from 4 to 48. In total, one hundred sixteen glycan compositions were reported, of which 57 compositions could be assigned consensus abundance values. These consensus medians provide community-derived values for NISTmAb PS. Agreement with the consensus medians did not depend on the specific method or laboratory type. The study provides a view of the current state-of-the-art for biologic glycosylation measurement and suggests a clear need for harmonization of glycosylation analysis methods.
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| 719. |
- de Wit, Meike, et al.
(författare)
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Cell surface proteomics identifies glucose transporter type 1 and prion protein as candidate biomarkers for colorectal adenoma-to-carcinoma progression
- 2012
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Ingår i: Gut. - : BMJ. - 0017-5749 .- 1468-3288. ; 61:6, s. 855-864
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective Early detection of colon adenomas at high risk of progression and early-stage colorectal cancer (CRC) is an effective approach to reduce CRC death rates. Current screening methods lack specificity as they detect many adenomas that will never progress to CRC. The authors aimed to identify cell surface protein biomarkers with extracellular domains that could be targeted for molecular imaging and discriminate low-risk adenomas and normal colon from high-risk adenomas and CRC. Design Cell surface proteins of five CRC cell lines were biotinylated, isolated and analysed by in-depth proteomics using gel electrophoresis and nanoliquid chromatography coupled to tandem mass spectrometry. Differential expression in adenomas and CRCs was based on mRNA expression and verified by immunohistochemical staining of tissue microarrays. Results In total, 2609 proteins were identified in the cell surface fractions. Of these, 44 proteins were selected as promising cell surface candidate biomarkers for adenoma-to-carcinoma progression based on the following criteria: protein identification in at least four out of five cell lines, a predicted (trans)membrane location and increased mRNA expression in CRCs compared to adenomas. Increased protein expression in high-risk adenomas and CRCs compared to low-risk adenomas was confirmed by immunohistochemistry for glucose transporter type 1 (gene symbol SLC2A1; p<0.00001) and prion protein (gene symbol PRNP; p<0.005). Conclusion This study revealed glucose transporter type 1, prion protein and 42 other cell surface candidate biomarkers for adenoma-to-carcinoma progression that could potentially serve as targets for emerging molecular imaging modalities like optical imaging, (19)F-MRI and positron emission tomography.
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| 720. |
- Demichev, Vadim, et al.
(författare)
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A time-resolved proteomic and prognostic map of COVID-19
- 2021
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Ingår i: Cell Systems. - : Elsevier BV. - 2405-4712 .- 2405-4720. ; 12:8, s. 780-794.e7
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Tidskriftsartikel (refereegranskat)abstract
- COVID-19 is highly variable in its clinical presentation, ranging from asymptomatic infection to severe organ damage and death. We characterized the time-dependent progression of the disease in 139 COVID-19 inpatients by measuring 86 accredited diagnostic parameters, such as blood cell counts and enzyme activities, as well as untargeted plasma proteomes at 687 sampling points. We report an initial spike in a systemic inflammatory response, which is gradually alleviated and followed by a protein signature indicative of tissue repair, metabolic reconstitution, and immunomodulation. We identify prognostic marker signatures for devising risk-adapted treatment strategies and use machine learning to classify therapeutic needs. We show that the machine learning models based on the proteome are transferable to an independent cohort. Our study presents a map linking routinely used clinical diagnostic parameters to plasma proteomes and their dynamics in an infectious disease.
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