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| 5. |
- Bergkvist, Leif, et al.
(författare)
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Axillary recurrence rate after negative sentinel node biopsy in breast cancer : three-year follow-up of the Swedish Multicenter Cohort Study
- 2008
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Ingår i: Annals of Surgery. - : Lippincott Williams & Wilkins. - 0003-4932 .- 1528-1140. ; 247:1, s. 150-156
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Tidskriftsartikel (refereegranskat)abstract
- Background: Sentinel lymph node biopsy is an established staging method in early breast cancer. After a negative biopsy, most institutions will not perform a completion axillary dissection. The present study reports the current axillary recurrence (AR) rate, overall and disease-free survival in the Swedish Multicenter Cohort Study.Methods: From 3534 patients with primary breast cancer ≤3 cm prospectively enrolled in the Swedish multicenter cohort study, 2246 with a negative sentinel node biopsy and no further axillary surgery were selected. Follow-up consisted of annual clinical examination and mammography. Twenty-six hospitals and 131 surgeons contributed to patient accrual.Results: After a median follow-up time of 37 months (0-75), the axilla was the sole initial site of recurrence in 13 patients (13 of 2246, 0.6%). In another 7 patients, axillary relapse occurred after or concurrently with a local recurrence in the breast, and in a further 7 cases, it coincided with distant or extra-axillary lymphatic metastases. Thus, a total of 27 ARs were identified (27 of 2246, 1.2%). The overall 5-year survival was 91.6% and disease-free survival 92.1%.Conclusions: This is the first report from a national multicenter study that covers, not only highly specialized institutions but also small community hospitals with just a few procedures per year. Despite this heterogeneous background, the results lie well within the range of AR rates published internationally (0%-3.6%). The sentinel node biopsy procedure seems to be safe in a multicenter setting. Nevertheless, long-term follow-up data should be awaited before firm conclusions are drawn.
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| 7. |
- Brommesson, Sara, et al.
(författare)
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Tiling array-CGH for the assessment of genomic similarities among synchronous unilateral and bilateral invasive breast cancer tumor pairs.
- 2008
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Ingår i: BMC Clinical Pathology. - : Springer Science and Business Media LLC. - 1472-6890. ; 8:July 10
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Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT: BACKGROUND: Today, no objective criteria exist to differentiate between individual primary tumors and intra- or intermammary dissemination respectively, in patients diagnosed with two or more synchronous breast cancers. To elucidate whether these tumors most likely arise through clonal expansion, or whether they represent individual primary tumors is of tumor biological interest and may have clinical implications. In this respect, high resolution genomic profiling may provide a more reliable approach than conventional histopathological and tumor biological factors. METHODS: 32 K tiling microarray-based comparative genomic hybridization (aCGH) was used to explore the genomic similarities among synchronous unilateral and bilateral invasive breast cancer tumor pairs, and was compared with histopathological and tumor biological parameters. RESULTS: Based on global copy number profiles and unsupervised hierarchical clustering, five of ten (p = 1.9 x 10-5) unilateral tumor pairs displayed similar genomic profiles within the pair, while only one of eight bilateral tumor pairs (p = 0.29) displayed pair-wise genomic similarities. DNA index, histological type and presence of vessel invasion correlated with the genomic analyses. CONCLUSION: Synchronous unilateral tumor pairs are often genomically similar, while synchronous bilateral tumors most often represent individual primary tumors. However, two independent unilateral primary tumors can develop synchronously and contralateral tumor spread can occur. The presence of an intraductal component is not informative when establishing the independence of two tumors, while vessel invasion, the presence of which was found in clustering tumor pairs but not in tumor pairs that did not cluster together, supports the clustering outcome. Our data suggest that genomically similar unilateral tumor pairs may represent a more aggressive disease that requires the addition of more severe treatment modalities, and underscores the importance of evaluating the clonality of multiple tumors for optimal patient management. In summary, our findings demonstrate the importance of evaluating the properties of both tumors in order to determine the most optimal patient management.
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| 8. |
- C Kapetanovic, Meliha, et al.
(författare)
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Influence of methotrexate, TNF blockers and prednisolone on antibody responses to pneumococcal polysaccharide vaccine in patients with rheumatoid arthritis.
- 2006
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Ingår i: Rheumatology. - : Oxford University Press (OUP). - 1462-0332 .- 1462-0324. ; 45:1, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To compare antibody responses to 23-valent pneumococcal vaccine (Pneumovax (R)) in controls and patients with established rheumatoid arthritis (RA) treated with TNF blockers, methotrexate (MTX) or a combination of both. Methods. Patients with RA (n = 149) and healthy controls (n = 47) were vaccinated. Treatment with TNF blockers (etanercept or infliximab) and MTX was given to 50 patients, and 62 patients were treated with TNF blockers alone or with other DMARDs. MTX alone was given to 37 patients. Concentrations of immunoglobulin G (IgG) antibodies against pneumococcal capsular polysaccharides 23F and 6B were measured by enzyme-linked immunoassay before and 4-6 weeks after vaccination. An immune response was defined as a twofold or higher increase in antibody concentration following vaccination. Results. Prevaccination antibody levels for both 23F and 6B were similar in the patient groups. Antibody concentrations after vaccination increased significantly in all groups. Patients treated with TNF blockers without MTX showed better immune responses than those treated with TNF blockers in combination with MTX (P = 0.037 for 23F and P = 0.004 for 6B) or MTX alone (P < 0.001 for both 23F and 6B). RA patients given MTX alone had the lowest immune responses. Prednisolone treatment did not influence the responses. Conclusions. Patients treated with TNF blockers and controls showed similar responses to vaccination. In contrast, patients treated with MTX had reduced responses regardless of anti-TNF treatment. The findings do not argue against the use of pneumococcal vaccination in RA patients undergoing treatment with TNF blockers.
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| 9. |
- Carneiro, Ana, et al.
(författare)
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Prognostic impact of array-based genomic profiles in esophageal squamous cell cancer
- 2008
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407. ; 8:98
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Tidskriftsartikel (refereegranskat)abstract
- Background: Esophageal squamous cell carcinoma (ESCC) is a genetically complex tumor type and a major cause of cancer related mortality. Although distinct genetic alterations have been linked to ESCC development and prognosis, the genetic alterations have not gained clinical applicability. We applied array-based comparative genomic hybridization (aCGH) to obtain a whole genome copy number profile relevant for identifying deranged pathways and clinically applicable markers. Methods: A 32 k aCGH platform was used for high resolution mapping of copy number changes in 30 stage I-IV ESCC. Potential interdependent alterations and deranged pathways were identified and copy number changes were correlated to stage, differentiation and survival. Results: Copy number alterations affected median 19% of the genome and included recurrent gains of chromosome regions 5p, 7p, 7q, 8q, 10q, 11q, 12p, 14q, 16p, 17p, 19p, 19q, and 20q and losses of 3p, 5q, 8p, 9p and 11q. High-level amplifications were observed in 30 regions and recurrently involved 7p11 (EGFR), 11q13 (MYEOV, CCND1, FGF4, FGF3, PPFIA, FAD, TMEM16A, CTTS and SHANK2) and 11q22 (PDFG). Gain of 7p22.3 predicted nodal metastases and gains of 1p36.32 and 19p13.3 independently predicted poor survival in multivariate analysis. Conclusion: aCGH profiling verified genetic complexity in ESCC and herein identified imbalances of multiple central tumorigenic pathways. Distinct gains correlate with clinicopathological variables and independently predict survival, suggesting clinical applicability of genomic profiling in ESCC.
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| 10. |
- Ekholm, Birgit, 1956-
(författare)
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Diagnostic Evaluation of Schizophrenia for Genetic Studies
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Schizophrenia is one of the most severe mental disorders. Heredity is accepted as a major causative factor. To find molecular mechanisms behind schizophrenia, patient materials with reliable and valid diagnoses must be identified. In order to compare schizophrenia diagnostic procedures for reliability, validity and suitability for genetic studies by evaluation of record information, interview and register diagnostic data and to examine patient materials for linkage or association with molecular genetic markers three patient materials were recruited: sporadic cases, a large pedigree and sib-pairs. Schizophrenia diagnoses based on patient records only, showed good to excellent agreement with diagnoses based on both records and interviews. Register diagnoses generally displayed poor agreement with research diagnoses, but in 94% of patients sometimes registered as schizophrenic psychoses a research diagnosis of these disorders was certified. In the pedigree, analysis suggested linkage to chr 6p23 in a single branch of the pedigree, and a genome scan indicated linkage to the 6q25 region. A genome scan analysis of the sib-pair material was suggestive of linkage to chr 10q25.3-q26.3. In the case-control sample and a meta-analysis there was an association between a dopamine D2 receptor polymorphism (Ser311Cys), on chr 11q22-23, and the disorder. Brain-derived neurotrophic factor gene variants (chr 11p13) were also analysed without any robust significant findings. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be valid, reliable and sufficient for assessment of lifetime research diagnosis. Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power in relation to corresponding research diagnoses. For future Swedish studies focusing on a broad definition of schizophrenia, it is sufficient to rely on the register diagnoses of schizophrenic psychosis. There is no major vulnerability gene or locus that is common to the majority of patients with schizophrenia, indicating genetic heterogeneity.
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| 11. |
- Ekholm, Birgit, et al.
(författare)
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Evaluation of diagnostic procedures in Swedish patients with schizophrenia and related psychoses
- 2005
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Ingår i: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 59:6, s. 457-464
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Tidskriftsartikel (refereegranskat)abstract
- We aimed to estimate the value of structured interviews, medical records and Swedish register diagnoses for assessing lifetime diagnosis of patients with schizophrenia. Psychiatric records and diagnostic interviews of 143 Swedish patients diagnosed by their treating physician with schizophrenia and related disorders were scrutinized. Based on record analysis only, or a combined record and interview analysis, DSM-IV diagnoses were obtained by the OPCRIT algorithm. Independent of the OPCRIT algorithm, a standard research DSM-IV diagnosis, based on both record and interview analysis, was given by the research psychiatrist. Concordance rates for the different psychosis diagnoses were calculated. DSM-IV diagnoses based on records only, showed a good to excellent agreement with diagnoses based on records and interviews. Swedish register diagnoses displayed generally poor agreement with the research diagnoses. Nevertheless, 94% of subjects sometimes registered with a diagnosis of schizophrenic psychoses (i.e. schizophrenia, schizoaffective psychosis or schizophreniform disorder) displayed a standard research DSM-IV diagnosis of these disorders. For patients in long-term treatment for schizophrenia in Sweden, psychiatric record reviews should be optimal, cost effective and sufficient for assessment of lifetime research diagnoses of schizophrenia. For these patients a research interview adds little new information. The results further indicate that a Swedish register diagnosis of schizophrenic psychoses has a high positive predictive power to a standard research DSM-IV diagnosis of the disorders. It is concluded that for future Swedish large-scale genetic studies focusing on a broad definition of schizophrenia, it would be sufficient to rely on the Swedish register diagnoses of schizophrenic psychosis.
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| 12. |
- Gustavsson, Lillemor, 1961-
(författare)
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Change of toxicity during secondary treatment of industrial sludge containing nitroaromatics
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wastewater treatment plants in Sweden are facing a great challenge due to the prohibition of depositing organic waste which gained legal force in January 2005. Biological and commercial available alternatives to disposal are composting and anaerobic digestion. A promising technique for wastewater and sludge treatment is the use of constructed wetland. In this thesis we have looked at the sludge from a wastewater treatment plant receiving wastewater from industries manufacturing pharmaceutical substances, chemical intermediates and explosives. The wastewater and sludge contains high concentrations of nitro-aromatic compounds and amino-aromatic compounds, both original compounds and degradation products. The degradation of nitroaromatics under different oxygen conditions is well examined and several studies have reported the alteration of nitroaromatics to more potent cytotoxic and genotoxic compounds after degradation. The use of bioassays is a practicable approach to estimate the toxic potency of complex samples such as sludge, since it is difficult to analyse all toxic compounds in a sample by using chemical analysis. The aim of this study was to follow change in toxicity in three different sludge treatment methods; aerobic composting and anaerobic digestion and constructed wetland to follow change in general and mechanism-specific toxicity. In order to detect both lipo- and hydrophilic compounds, different extraction and bioassays are necessary. We used organic solvents and multi-layer cleaned-up samples in the DR-Calux assay to detect the persistent lipophilic compounds causing dioxin-like activity. We also used both water and acetone extracts in the umu-C assay to detect genotoxicity and in the fishegg assay to detect embryotoxicty of water and semi-water soluble compounds in low concentrations. The results showed that anaerobic treatment is less suitable for this particular sludge, since the anaerobic residues showed high induction in all toxicity tests compared to the residues of the aerobic treatment. The anaerobic treatment also transformed the toxicants in the sludge to more lipophilic and persistent forms as well as to more water soluble, genotoxic compounds. This makes the treated material difficult to handle due to the toxic potential of the material as well as of the leachate. The aerobic treated material also showed an increased toxic potential of the material but the leachate showed no toxicity. However, high concentrations of nitrite were formed during both aerobic and anaerobic treatment, which is of environmental concern. The constructed wetlands eluated a non-toxic effluent and had a bed material with lower toxicity than expected considering the sludge concentrations and loaded sludge amount. The bed material contained concentration of TEQ considered as acceptable levels for sensitive ground use such as parks, lawns and other grounds without groundwater protection. However, all three treatment methods need to be optimised and the residual needs further evaluation in order to establish a suitable biodegradation method.
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| 14. |
- Hansén Nord, Karolin, et al.
(författare)
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Frequent deletion of the CDKN2A locus in chordoma: analysis of chromosomal imbalances using array comparative genomic hybridisation.
- 2008
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 1532-1827 .- 0007-0920. ; 98:2, s. 434-442
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Tidskriftsartikel (refereegranskat)abstract
- The initiating somatic genetic events in chordoma development have not yet been identified. Most cytogenetically investigated chordomas have displayed near-diploid or moderately hypodiploid karyotypes, with several numerical and structural rearrangements. However, no consistent structural chromosome aberration has been reported. This is the first array-based study characterising DNA copy number changes in chordoma. Array comparative genomic hybridisation (aCGH) identified copy number alterations in all samples and imbalances affecting 5 or more out of the 21 investigated tumours were seen on all chromosomes. In general, deletions were more common than gains and no high-level amplification was found, supporting previous findings of primarily losses of large chromosomal regions as an important mechanism in chordoma development. Although small imbalances were commonly found, the vast majority of these were detected in single cases; no small deletion affecting all tumours could be discerned. However, the CDKN2A and CDKN2B loci in 9p21 were homo- or heterozygously lost in 70% of the tumours, a finding corroborated by fluorescence in situ hybridisation, suggesting that inactivation of these genes constitute an important step in chordoma development.British Journal of Cancer (2008) 98, 434-442. doi:10.1038/sj.bjc.6604130 www.bjcancer.com Published online 11 December 2007.
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| 16. |
- Holst, Martina, et al.
(författare)
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Molecular mechanisms underlying N1, N11-diethylnorspermine-induced apoptosis in a human breast cancer cell line.
- 2008
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Ingår i: Anti-Cancer Drugs. - 0959-4973. ; 19:9, s. 871-883
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Tidskriftsartikel (refereegranskat)abstract
- Polyamine analogue treatment results in growth inhibition and sometimes in cell death. Therefore, polyamine analogues are considered in the treatment of cancer; however, the cellular properties that govern sensitivity are not known. The objective of this study was to elucidate molecular mechanisms behind apoptosis induced by the polyamine analogue N, N-diethylnorspermine (DENSPM). Four different breast cancer cell lines were treated with DENSPM. Cell death was evaluated with flow cytometry and a caspase 3 assay. The levels of a number of proapoptotic and antiapoptotic proteins in subcellular compartments were evaluated with western blot. In the most sensitive cell line, DENSPM treatment induced the release of cytochrome c from mitochondria, resulting in activation of caspase 3 but without decreasing the mitochondrial transmembrane potential. However, in the three other cell lines DENSPM treatment did not induce extensive cell death. This is partly explained by the high levels of antiapoptotic proteins Bcl-2 and Bad and low levels of proapoptotic proteins Bax and procaspase 3 in these three cell lines. The results are also partly explained by the degree of activation of the catabolic enzyme spermidine/spermine-N-acetyltransferase and polyamine pool reduction achieved by DENSPM treatment. Our results show that the protein profile of proapoptotic and antiapoptotic proteins may contribute to the outcome to treatment with the polyamine analogue DENSPM. The results also indicate that it should be possible to find molecular markers for sensitivity to DENSPM that could be used in the clinic to predict sensitivity to a polyamine analogue.
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| 17. |
- Jirström, Karin, et al.
(författare)
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Pathology parameters and adjuvant tamoxifen response in a randomised premenopausal breast cancer trial
- 2005
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Ingår i: Journal of Clinical Pathology. - : BMJ. - 0021-9746 .- 1472-4146. ; 58:11, s. 1135-1142
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Tidskriftsartikel (refereegranskat)abstract
- Background: Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment.Aims: To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer.Materials/methods: Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression.Results: Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly.Conclusions: Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.
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| 18. |
- Johannsdottir, Hrefna K., et al.
(författare)
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Chromosome 5 imbalance mapping in breast tumors from BRCA1 and BRCA2 mutation carriers and sporadic breast tumors
- 2006
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 119:5, s. 1052-1060
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Tidskriftsartikel (refereegranskat)abstract
- Comparative genomic hybridization (CGH) analysis has shown that chromosome 5q deletions are the most frequent aberration in breast tumors from BRCA1 mutation carriers. To map the location of putative 5q tumor suppressor gene(s), 26 microsatellite markers covering chromosome 5 were used in loss of heterozygosity (LOH) analysis of breast tumors from BRCA1 (n = 42) and BRCA2 mutation carriers (n = 67), as well as in sporadic cases (n = 65). High, density array CGH was also used to map chromosome 5 imbalance in 10 BRCA1 tumors. A high LOH frequency was found in BRCA1 tumors (range 19-82%), as compared to BRCA2 and sporadic tumors (ranges 11-44% and 7-43%, respectively). In all, 11 distinct chromosome 5 regions with LOH were observed, the most frequent being 5q35.3 (82%), 5q14.2 (71%) and 5q33.1 (69%) in BRCA1 tumors; 5q35.3 (44%), 5q31.3 (43%) and 5q13.3 (43%) in BRCA2 tumors and 5q31.3 (43%) in sporadic tumors. Array CGH analysis confirmed the very high frequency of 5q deletions, including candidate tumor suppressor genes such as XRCC4, RAD50, RASA1, APC and PPP2R2B. In addition, 2 distinct homozygous deletions were identified, spanning regions of 0.7-1.5 Mbp on 5q12.1 and 5q12.3-q13.1, respectively. These regions include only a few genes, most notably BRCC3/DEPDC1B (pleckstrin/G protein interacting and RhoGAP domains) and PIK3R1 (PI3 kinase P85 regulatory subunit). Significant association (p <= 0.05) was found between LOH at certain 5q regions and factors of poor prognosis, including negative estrogen and progesterone receptor status, high grade, large tumor size and high portion of cells in S-phase. In conclusion, our results confirm a very high prevalence of chromosome 5q alterations in BRCA1 tumors, pinpointing new regions and genes that should be further investigated. (c) 2006 Wiley-Liss, Inc.
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| 19. |
- Johansson, Veronica, et al.
(författare)
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Effect of polyamine deficiency on proteins involved in Okazaki fragment maturation.
- 2008
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Ingår i: Cell Biology International. - : Wiley. - 1095-8355 .- 1065-6995. ; 32, s. 1467-1477
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Tidskriftsartikel (refereegranskat)abstract
- Polyamine depletion causes S phase prolongation, and earlier studies indicate that the elongation step of DNA replication is affected. This led us to investigate the effects of polyamine depletion on enzymes crucial for Okazaki fragment maturation in the two breast cancer cell lines MCF-7 and L56Br-C1. In MCF-7 cells, treatment with N(1),N(11)-diethylnorspermine (DENSPM) causes S phase prolongation. In L56Br-C1 cells the prolongation is followed by massive apoptosis. In the present study we show that L56Br-C1 cells have substantially lower basal expressions of two Okazaki fragment maturation key proteins, DNA ligase I and FEN1, than MCF-7 cells. Thus, these two proteins might be promising markers for prediction of polyamine depletion sensitivity, something that can be useful for cancer treatment with polyamine analogues. DENSPM treatment affects the cellular distribution of FEN1 in L56Br-C1 cells, but not in MCF-7 cells, implying that FEN1 is affected by or involved in DENSPM-induced apoptosis.
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| 20. |
- Jönsson, Anders, et al.
(författare)
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A Virtual Machine Concept for Real-Time Simulation of Machine Tool Dynamics
- 2005
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Ingår i: International journal of machine tools & manufacture. - : Elsevier. - 0890-6955 .- 1879-2170. ; 45:7, s. 795-801
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Tidskriftsartikel (refereegranskat)abstract
- When designing CNC machine tools it is important to consider the dynamics of the control, the electrical components and the mechanical structure of the machine simultaneously. This paper describes the structure and implementation of a concept for real-time simulation of such machine tools using a water jet cutting machine as an application. The concept includes a real control system, simulation models of the dynamics of the machine and a virtual reality model for visualisation. The real-time capability of the concept, including the simulation of electrical and rather detailed mechanical component models is proofed. The validation process indicates good agreement between simulation and measurement, but suggests further studies on servo motor, connection and flexibility modelling. However, already from the initial simulation results presented in this paper it can be concluded that the influence of structural flexibility on manufacturing accuracy is of importance at desired feeding rates and accelerations. The fully automated implementation developed in this work is a promising base for dealing with this trade-off between productivity and accuracy of the manufacturing process through multidisciplinary optimisation.
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| 21. |
- Jönsson, Anders, et al.
(författare)
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Implications of modelling one-dimensional impact by using a spring and damper element
- 2005
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Ingår i: Proceedings of the Institution of mechanical engineers. Proceedings part K, journal of multi-body dynamics. - London : Professional Engineering Publishing. - 1464-4193 .- 2041-3068. ; 219:7, s. 299-305
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Tidskriftsartikel (refereegranskat)abstract
- A spring and damper contact force element is often used for modelling impact in multi-body dynamics. The related condition for transition between contact and non-contact is, however, inconsistently implemented in the literature and commercial software. This comparative study aims to clarify the implications of four commonly used transition conditions. Principal differences are discussed and, by simulation of a typical system, it is shown that there are significant differences in the dynamics of the system depending on the different conditions. Two of them give unrealistic contact forces and should imply incorrect prediction of system dynamics in most applications. This suggests that it is important to review results obtained from using these conditions and to eliminate them from commercial software. A discussion of the two other conditions culminates in a recommendation.
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| 22. |
- Jönsson, Björn, 1951-, et al.
(författare)
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A new probe for ankle systolic pressure measurement using Photoplethysmography (PPG)
- 2005
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Ingår i: Annals of Biomedical Engineering. - : Springer Science and Business Media LLC. - 0090-6964 .- 1573-9686. ; 33:2, s. 232-239
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Tidskriftsartikel (refereegranskat)abstract
- An automated method for ankle systolic pressure measurement, less operator dependent than the standard continuous wave (CW) Doppler technique, would imply an advantage both in patient measurements and in epidemiological studies. We present a new photoplethysmographic (PPG) probe that uses near-infrared light (880 nm) to detect pulsatory blood flow underneath the distal end of a standard pneumatic cuff. The probe is adapted to the anatomical conditions at the ankle, permitting recording of pressures in both ankle arteries separately. The validity of the equipment was tested with CW Doppler-derived systolic pressures and invasive blood pressure measurements for reference. In 20 healthy subjects, visual analysis of the PPG curves revealed a mean difference between CW Doppler and PPG measurements of –0.5 mmHg (SD 6.9). Corresponding results for the anterior and posterior tibial arteries separately were –1.8 mmHg (SD 6.2) and 0.9 mmHg (SD 7.3), respectively. A correct probe position was essential for the results. In direct recordings from the dorsalis pedis artery in 10 intensive care patients, PPG underestimated systolic pressure in the anterior tibial artery by 4.5 mmHg (SD 12.1). With further development, the PPG probe, integrated in the pneumatic cuff, may simplify measurements of ankle systolic pressures.
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| 23. |
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| 24. |
- Jönsson, Björn, 1951-, et al.
(författare)
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Automatic ankle pressure measurements using PPG in ankle-brachial pressure index determination
- 2005
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Ingår i: European Journal of Vascular and Endovascular Surgery. - : Elsevier BV. - 1078-5884 .- 1532-2165. ; 30:4, s. 395-401
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveTo evaluate a new technique using a photoplethysmographic (PPG) probe for automatic ankle pressure measurements.DesignComparative study on two techniques for ankle pressure measurement.SettingUniversity hospital.MaterialThirty-five patients with leg arterial disease and eight healthy volunteers. Ankle-brachial indices (ABPI) were measured using conventional CW Doppler technique and PPG-based prototype equipment for the ankle pressure recordings.Chief outcome measuresABPIs calculated from CW Doppler and PPG ankle pressure measurements. The PPG signals were analysed both by visual judgement and by a software based, automatic algorithm.Main resultsThe mean difference between ABPIs calculated from CW Doppler recordings and PPG (visual analysis) was −0.01 (limits of agreement (±two standard deviations) +0.16 to −0.19). The correlation coefficient was 0.93. When the algorithm was used, the mean difference (CW Doppler−PPG) was 0.05 (limits of agreement 0.28 to −0.18, r=0.89).ConclusionsThe PPG method is a promising technique with an inherent potential for automatisation of the ankle pressure measurements, thereby reducing the observer-dependency in ABPI recordings.
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| 25. |
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