| 1. |
- Andersson Grönlund, Marita, 1959-, et al.
(författare)
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Ophthalmological findings in children and young adults with genetically verified mitochondrial disease
- 2010
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Ingår i: British Journal of Ophthalmology. - : BMJ Publishing Group Ltd. - 0007-1161 .- 1468-2079. ; 94:1, s. 121-127
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To describe ophthalmological phenotypes in patients with mitochondrial disease and known genotypes.METHODS: A retrospective study was performed on 59 patients (29 male, 30 female) with a mean age of 11.8 years who had mitochondrial disease with known DNA mutations. Fifty-seven of the 59 subjects underwent a detailed ophthalmological examination including visual acuity (VA), eye motility, refraction, slit-lamp examination, ophthalmoscopy and, in almost one-half of the cases, a full-field electroretinogram (ERG).RESULTS: Forty-six (81%) of the patients had one or more ophthalmological findings such as ptosis (n = 16), reduced eye motility (n = 22) including severe external ophthalmoplegia (n = 9), strabismus (n = 4), nystagmus (n = 9), low VA (n = 21), refractive errors (n = 26), photophobia (n = 4), and partial or total optic atrophy (n = 25). Pigmentation in the macula and/or periphery was noted in 16 patients. In 10/27 investigated individuals with full field ERG, retinal dystrophy was recorded in six different genotypes representing Kearns-Sayre syndrome (n = 5), Leigh syndrome (n = 1), Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) (n = 1), Myoclonus epilepsy with red ragged fibres (MERRF) (n = 1), Leber hereditary optic neuropathy (n = 1) and mitochondrial myopathy (n = 1).CONCLUSION: The results show that a majority of patients with mitochondrial disorders have ophthalmological abnormalities. We recommend that an ophthalmological examination, including ERG, be performed on all children and adolescents who are suspected of having a mitochondrial disease.
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| 2. |
- Darin, Niklas, 1964, et al.
(författare)
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Mitochondrial myopathy with exercise intolerance and retinal dystrophy in a sporadic patient with a G583A mutation in the mt tRNA(phe) gene
- 2006
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Ingår i: Neuromuscular disorders : NMD. - : Elsevier BV. - 0960-8966 .- 1873-2364. ; 16:8, s. 504-6
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Tidskriftsartikel (refereegranskat)abstract
- We describe a second patient with the 583G>A mutation in the tRNA(phe) gene of mitochondrial DNA (mtDNA). This 17-year-old girl had a mitochondrial myopathy with exercise intolerance and an asymptomatic retinopathy. Muscle investigations showed occasional ragged red fibers, 30% cytochrome c oxidase (COX)-negative fibers, and reduced activities of complex I+IV in the respiratory chain. The mutation was heteroplasmic (79%) in muscle but undetectable in other tissues. Analysis of single muscle fibers revealed a significantly higher level of mutated mtDNA in COX-negative fibers. Our study indicates that the 583G>A mutation is pathogenic and expands the clinical spectrum of this mutation.
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| 3. |
- Hultdin, Magnus, et al.
(författare)
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Replication timing of human telomeric DNA and other repetitive sequences analyzed by fluorescence in situ hybridization and flow cytometry
- 2001
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Ingår i: Experimental Cell Research. - : Elsevier. - 0014-4827. ; 271, s. 223-229
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Tidskriftsartikel (refereegranskat)abstract
- The replication timing of telomeres seems to differ between species. Yeast telomeres are late replicating, whereas limited data from very few human cell lines have indicated telomere replication throughout S phase. In the present study a series of permanent cell lines and patient samples was investigated using a flow cytometric approach for telomere length determination based on in situ hybridization using peptide nucleic acid probes and DNA staining. This method permits selective analysis of cells in specific phases of the cell cycle without perturbation of the cell cycle machinery. The timing of replication of telomeric C(3)TA(2) and T(2)AG(3) repeats was found to differ between individual samples and could precede or be concomitant with the replication of bulk DNA. Replication of the T(2)AG(3) strand seemed to occur somewhat later than that of the C(3)TA(2) strand in some samples. (GTG)(n) and other repetitive sequences generally showed a replication pattern similar to that of the bulk of DNA with slightly individual differences, whereas centromeric DNA repeats consistently replicated within a short time frame in late S phase. The apparent variability in replication timing seen for telomeric DNA might suggest individual differences in firing of replication origins.
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| 4. |
- Hultdin, Magnus, et al.
(författare)
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Telomere analysis by fluorescence in situ hybridization and flow cytometry
- 1998
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Ingår i: Nucleic Acids Research. - Oxford : Oxford University Press. - 0305-1048 .- 1362-4962. ; 26:16, s. 3651-3656
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Tidskriftsartikel (refereegranskat)abstract
- Determination of telomere length is traditionally performed by Southern blotting and densitometry, giving a mean telomere restriction fragment (TRF) value for the total cell population studied. Fluorescence in situ hybridization (FISH) of telomere repeats has been used to calculate telomere length, a method called quantitative (Q)-FISH, We here present a quantitative flow cytometric approach, Q-FISHFCM, for evaluation of telomere length distribution in individual cells based on in situ hybridization using a fluorescein-labeled peptide nucleic acid (PNA) (CCCTAA)(3) probe and DMA staining with propidium iodide, A simple and rapid protocol with results within 30 h was developed giving high reproducibility, One important feature of the protocol was the use of an internal cell line control, giving an automatic compensation for potential differences in the hybridization steps. This protocol was tested successfully on cell lines and clinical samples from bone marrow, blood, lymph nodes and tonsils. A significant correlation was found between Southern blotting and Q-FISHFCM telomere length values (P = 0.002), The mean sub-telomeric DNA length of the tested cell lines and clinical samples was estimated to be 3.2 kbp, With the Q-FISHFCM method the fluorescence signal could be determined in different cell cycle phases, indicating that in human cells the vast majority of telomeric DNA is replicated early in S phase.
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| 5. |
- Li, Aihong, et al.
(författare)
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Automated white blood cell counts in cerebrospinal fluid using the body fluid mode on the platform Sysmex XE-5000
- 2014
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa Healthcare. - 0036-5513 .- 1502-7686. ; 74:8, s. 673-680
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The Sysmex XE-5000 offers automated quantification of red blood cells and white blood cells (WBCs) in body fluids, with differentiation of polymorphonuclear cells (PMNs) and mononuclear cells (MNCs). METHODS: We evaluated automated WBC counting in cerebrospinal fluid (CSF) using the body fluid mode on the Sysmex XE-5000, comparing it with flow cytometry as the reference method, and also with manual counting by microscopy. Experimental analysis for linearity and limit of detection was performed by diluting isolated WBCs in cell-free CSF. To study the ability to discriminate between PMNs and MNCs, samples were spiked using MNCs separated from peripheral blood. Comparison of WBC counts between a counting chamber and the XE-5000 was performed for 198 CSF samples. RESULTS: In the experimental set-up, within-run (CV 19%) and between-day imprecision (CV 15.3%) in quantitating total number of WBC on XE-5000 was acceptable for WBC counts >= 25x10(6)/L. Compared with expected cell counts, mean bias was +/- 2.6% for flow cytometry, +/- 5.5% for XE-5000 and -73.2% for manual counting. Differentiation between PMNs and MNCs was in concordance with flow cytometry. In comparisons of clinical CSF samples, overall agreement between the XE-5000 and manual counting was observed in 81% of the samples, but mean difference in WBC differentiation was higher for PMN (51.1x10(6)/L) than for MNC (7.95x10(6)/L). CONCLUSION: Despite limited precision at low WBC counts, XE-5000 could be a favourable alternative to the labour-intensive, time-consuming and less reliable manual counting and cuts turnaround times in routine CSF-based diagnosis.
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| 6. |
- Liljeholm, Maria, 1973-, et al.
(författare)
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Erythrocyte Flow Cytometric Analysis in Congenital Dyserythropoietic Anemia Type III-Evaluation of Eosin-5´-Maleimide, CD55, and CD59
- 2013
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Ingår i: Journal of Blood Disorders & Transfusion. - : OMICS International. - 2155-9864. ; 121:23, s. 4791-4799
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Flow cytometry with eosin-5´-maleimide (EMA), anti-CD55 and anti-CD59 is commonly used when investigating non-autoimmune hemolytic anemias. Reduced fluorescence of EMA, typically detected in hereditary spherocytosis is also seen in congenital dyserythropoietic anemia type II (CDA II). Reduction of CD55 and CD59 characterizes paroxysmal nocturnal hemoglobinuria (PNH). We studied the flow cytometric profile of EMA, CD55 and CD59 on erythrocytes in congenital dyserythropoietic anemia type III (CDA III). Methods: Erythrocytes from 16 CDA III positive individuals, 14 CDA III negative relatives and three normal controls per assay were studied with flow cytometry after EMA staining. Flow cytometry after anti-CD55 and anti- CD59 was performed on erythrocytes from 12 CDA III positive and 7 CDA III negative relatives with one normal control per assay. Results: CDA III - erythrocytes exhibited marginally stronger fluorescence after EMA-staining than normal controls. Correlation between EMA fluorescence and erythrocyte volume was confirmed. CDA III subjects did not differ from normal controls concerning CD55 and CD59. Conclusion: The results of the present study indicate no abnormality of the erythrocyte membrane in CDA III and show that standard flow cytometry cannot be used to discriminate between CDA III and normal controls.
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| 7. |
- Roos, Sara, 1979, et al.
(författare)
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A novel mitochondrial tRNA Arg mutation resulting in an anticodon swap in a patient with mitochondrial encephalomyopathy.
- 2013
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Ingår i: European journal of human genetics : EJHG. - : Springer Science and Business Media LLC. - 1476-5438 .- 1018-4813. ; 21:5, s. 571-3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We report a mutation in the anticodon of the tRNA(Arg) gene (m.10437G>A), resulting in an anticodon swap from GCU to ACU, which is the anticodon of tRNA(Trp), in a boy with mitochondrial encephalomyopathy. Enzyme histochemical analysis of muscle tissue and biochemical analysis of isolated muscle mitochondria demonstrated cytochrome c oxidase (COX) deficiency. Restriction fragment length polymorphism analysis showed that 90% of muscle and 82% of urinary epithelium mtDNA harbored the mutation. The mutation was not identified in blood, fibroblasts, hair roots, or buccal epithelial cells and it was absent in the asymptomatic mother, suggesting that it was a de novo mutation. Single-fiber PCR analysis showed that the proportion of mutated mtDNA correlated with enzyme histochemical COX deficiency. This mutation adds to the three previously described disease-causing mutations in tRNA(Arg), but it is the first mutation occurring in the anticodon of tRNA(Arg).European Journal of Human Genetics advance online publication, 11 July 2012; doi:10.1038/ejhg.2012.153.
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| 8. |
- Svenson, Ulrika, et al.
(författare)
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Telomere length in relation to immunological parameters in patients with renal cell carcinoma
- 2013
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Ingår i: PLOS ONE. - : Public Library Science. - 1932-6203. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- Over the last decade, telomere length (TL) has gained attention as a potential biomarker in cancer disease. We previously reported that long blood TL was associated with a poorer outcome in patients with breast cancer and renal cell carcinoma. Based on these findings, we hypothesized that certain immunological components may have an impact on TL dynamics in cancer patients. One aim of the present study was to investigate a possible association between serum cytokines and TL of peripheral blood cells, tumors and corresponding kidney cortex, in patients with clear cell renal cell carcinoma. For this purpose, a multiplex cytokine assay was used. Correlation analysis revealed significant positive correlations between tumor TL and peripheral levels of three cytokines (IL-7, IL-8 and IL-10). In a parallel patient group with various kidney tumors, TL was investigated in whole blood and in immune cell subsets in relation to peripheral levels of regulatory T cells (Tregs). A significant positive association was found between whole blood TL and Treg levels. However, the strongest correlation was found between Tregs and TL of the T lymphocyte fraction. Thus, patients with higher Treg levels displayed longer T cell telomeres, which might reflect a suppressed immune system with fewer cell divisions and hence less telomere shortening. These results are in line with our earlier observation that long blood TL is an unfavorable prognostic factor for cancer-specific survival. In summary, we here show that immunological components are associated with TL in patients with renal cell carcinoma, providing further insight into the field of telomere biology in cancer.
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| 9. |
- Thörn, Ingrid, 1957-, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukemia : Results of a Swedish multi-centre study comparing real-time PCR and multi-colour flow cytometry
- 2009
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this Swedish multi-center study of early treatment response in childhood acute lymphoblastic leukemia (ALL), we evaluated the concordance between multicolour flow cytometry (FCM) and real-time quantitative polymerase chain reaction (RQ-PCR) for assessment of minimal residual disease (MRD). Multiple time points (i.e. day 15, 29, 50 and 106) were evaluated with the NOPHO (Nordic Society of Pediatric Hematology and Oncology) ALL 2000 treatment protocol as backbone. During 2002-2006, 334 children were diagnosed with ALL, where 228 had paired samples taken at any of the four time points. With the detection level of 0.1%, the concordance between RQ-PCR and FCM was 90% in the 726 paired samples analyzed. At day 29, the correlation between the methods was greater with MRD levels >0.1% (rs=0.7, p<0.001) than below (rs=0.2, p=0.024). MRD levels higher than 0.1% at day 29 was a significant predictor of higher risk of having a bone marrow relapse. This was true both for BCP ALL and T-ALL analysed with either FCM or RQ-PCR, although RQ-PCR was a better discriminator than FCM in T-ALL. However, using the NOPHO ALL 2000 protocol, our data indicate that a higher cut-off value (0.2%) should be applied in BCP ALL when using RQ-PCR as MRD method. In contrast, MRD levels ≥ 0.1%, analysed with either method late during induction therapy, was not a predictor of isolated extramedullary relapse. We therefore conclude that MRD assessment by RQ-PCR based IG/TCR rearrangement and multicolour FCM monitoring can be used as a clinical tool if the aim is to find childhood ALL cases with increased risk of having bone marrow relapses.
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| 10. |
- Thörnerup, Ingrid, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukaemia: a Swedish multi-centre study comparing real-time polymerase chain reaction and multicolour flow cytometry.
- 2011
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 152:6, s. 743-753
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Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) assessment is a powerful prognostic factor for determining the risk of relapse in childhood acute lymphoblastic leukaemia (ALL). In this Swedish multi-centre study of childhood ALL diagnosed between 2002 and 2006, the MRD levels were analysed in 726 follow-up samples in 228 children using real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes and multicolour flow cytometry (FCM). Using an MRD threshold of 0·1%, which was the sensitivity level reached in all analyses, the concordance between RQ-PCR and FCM MRD values at day 29 was 84%. In B-cell precursor ALL, an MRD level of ≥0·1% at day 29 predicted a higher risk of bone marrow relapse (BMR) with both methods, although FCM was a better discriminator. However, considering the higher median MRD values achieved with RQ-PCR, a higher MRD cut-off (≥0·2%) improved the predictive capacity of RQ-PCR. In T-ALL, RQ-PCR was notably superior to FCM in predicting risk of BMR. That notwithstanding, MRD levels of ≥0·1%, detected by either method at day 29, could not predict isolated extramedullary relapse. In conclusion, the concordance between RQ-PCR and FCM was high and hence both methods are valuable clinical tools for identifying childhood ALL cases with increased risk of BMR.
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| 11. |
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