| 1. |
- Cossarizza, A., et al.
(författare)
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Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition)
- 2019
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Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 49:10, s. 1457-1973
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Tidskriftsartikel (refereegranskat)abstract
- These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.
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| 2. |
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| 3. |
- Schoch, C. L., et al.
(författare)
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A class-wide phylogenetic assessment of Dothideomycetes
- 2009
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Ingår i: Studies in mycology. - : Westerdijk Fungal Biodiversity Institute. - 0166-0616 .- 1872-9797. ; 64, s. 1-15
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Forskningsöversikt (refereegranskat)abstract
- We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41 families (six newly described in this volume) in Dothideomycetes. All currently accepted orders in the class are represented for the first time in addition to numerous previously unplaced lineages. Subclass Pleosporomycetidae is expanded to include the aquatic order Jahnulales. An ancestral reconstruction of basic nutritional modes supports numerous transitions from saprobic life histories to plant associated and lichenised modes and a transition from terrestrial to aquatic habitats are confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon.
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| 4. |
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| 5. |
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| 6. |
- Odin, Per, et al.
(författare)
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Collective physician perspectives on non-oral medication approaches for the management of clinically relevant unresolved issues in Parkinson's disease: Consensus from an international survey and discussion program.
- 2015
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Ingår i: Parkinsonism & Related Disorders. - : Elsevier BV. - 1873-5126 .- 1353-8020. ; 21:10, s. 1133-1144
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Forskningsöversikt (refereegranskat)abstract
- Navigate PD was an educational program established to supplement existing guidelines and provide recommendations on the management of Parkinson's disease (PD) refractory to oral/transdermal therapies. It involved 103 experts from 13 countries overseen by an International Steering Committee (ISC) of 13 movement disorder specialists. The ISC identified 71 clinical questions important for device-aided management of PD. Fifty-six experts responded to a web-based survey, rating 15 questions as 'critically important;' these were refined to 10 questions by the ISC to be addressed through available evidence and expert opinion. Draft guidance was presented at international/national meetings and revised based on feedback. Key take-home points are: • Patients requiring levodopa >5 times daily who have severe, troublesome 'off' periods (>1-2 h/day) despite optimal oral/transdermal levodopa or non-levodopa-based therapies should be referred for specialist assessment even if disease duration is <4 years. • Cognitive decline related to non-motor fluctuations is an indication for device-aided therapies. If cognitive impairment is mild, use deep brain stimulation (DBS) with caution. For patients who have cognitive impairment or dementia, intrajejunal levodopa infusion is considered as both therapeutic and palliative in some countries. Falls are linked to cognitive decline and are likely to become more frequent with device-aided therapies. • Insufficient control of motor complications (or drug-resistant tremor in the case of DBS) are indications for device-aided therapies. Levodopa-carbidopa intestinal gel infusions or subcutaneous apomorphine pump may be considered for patients aged >70 years who have mild or moderate cognitive impairment, severe depression or other contraindications to DBS.
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| 7. |
- Ebrahimi-Fakhari, Darius, et al.
(författare)
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Defining the clinical, molecular and imaging spectrum of adaptor protein complex 4-associated hereditary spastic paraplegia
- 2020
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Ingår i: Brain. - OXFORD ENGLAND : Oxford University Press (OUP). - 0006-8950 .- 1460-2156. ; 143:10, s. 2929-2944
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Tidskriftsartikel (refereegranskat)abstract
- Bi-allelic loss-of-function variants in genes that encode subunits of the adaptor protein complex 4 (AP-4) lead to prototypical yet poorly understood forms of childhood-onset and complex hereditary spastic paraplegia: SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). Here, we report a detailed cross-sectional analysis of clinical, imaging and molecular data of 156 patients from 101 families. Enrolled patients were of diverse ethnic backgrounds and covered a wide age range (1.0-49.3 years). While the mean age at symptom onset was 0.8 +/- 0.6 years [standard deviation (SD), range 0.2-5.0], the mean age at diagnosis was 10.2 +/- 8.5 years (SD, range 0.1-46.3). We define a set of core features: early-onset developmental delay with delayed motor milestones and significant speech delay (50% non-verbal); intellectual disability in the moderate to severe range; mild hypotonia in infancy followed by spastic diplegia (mean age: 8.4 +/- 5.1 years, SD) and later tetraplegia (mean age: 16.1 +/- 9.8 years, SD); postnatal microcephaly (83%); foot deformities (69%); and epilepsy (66%) that is intractable in a subset. At last follow-up, 36% ambulated with assistance (mean age: 8.9 +/- 6.4 years, SD) and 54% were wheelchair-dependent (mean age: 13.4 +/- 9.8 years, SD). Episodes of stereotypic laughing, possibly consistent with a pseudobulbar affect, were found in 56% of patients. Key features on neuroimaging include a thin corpus callosum (90%), ventriculomegaly (65%) often with colpocephaly, and periventricular white-matter signal abnormalities (68%). Iron deposition and polymicrogyria were found in a subset of patients. AP4B1-associated SPG47 and AP4M1-associated SPG50 accounted for the majority of cases. About two-thirds of patients were born to consanguineous parents, and 82% carried homozygous variants. Over 70 unique variants were present, the majority of which are frameshift or nonsense mutations. To track disease progression across the age spectrum, we defined the relationship between disease severity as measured by several rating scales and disease duration. We found that the presence of epilepsy, which manifested before the age of 3 years in the majority of patients, was associated with worse motor outcomes. Exploring genotype-phenotype correlations, we found that disease severity and major phenotypes were equally distributed among the four subtypes, establishing that SPG47, SPG50, SPG51 and SPG52 share a common phenotype, an 'AP-4 deficiency syndrome'. By delineating the core clinical, imaging, and molecular features of AP-4-associated hereditary spastic paraplegia across the age spectrum our results will facilitate early diagnosis, enable counselling and anticipatory guidance of affected families and help define endpoints for future interventional trials.
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| 8. |
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| 9. |
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| 10. |
- Saketkoo, LA, et al.
(författare)
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World Health Organization (WHO) International Classification of Functioning, Disability and Health (ICF) Core Set Development for Interstitial Lung Disease
- 2022
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Ingår i: Frontiers in pharmacology. - : Frontiers Media SA. - 1663-9812. ; 13, s. 979788-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The World Health Organization (WHO) introduced the International Classification of Functioning, Disability, and Health (ICF) as a scientific method of disability data collection comprised of >1,200 categories describing the spectrum of impairment types (functional, symptoms-based and anatomical) under the bio-psycho-social model with consideration of environmental and personal factors (pf). ICF Core Sets and ICF Checklists are streamlined disease-specific resources for clinical use, service provision, and for use in health economics and health policy. ICF can disclose strengths and weaknesses across multiple patient-reported outcome measures (PROMs) and help consolidate best-fitting question-items from multiple PROMs. Interstitial lung diseases (ILDs), are generally progressive, with restrictive physiology sometimes occurring in the context of multi-organ autoimmunity/inflammatory conditions such as connective tissue diseases (CTDs). In spite of significant associated morbidity and potential disability, ILD has yet to be linked to the ICF.Methods: Each instrument and their question-items within the consensus-recommended core sets for clinical trials in ILD were deconstructed to single concept units, and then linked per updated ICF linkage rules. Inter-linker agreement was established. Three additional subsequently validated measures were also included.Results: One-hundred-eleven ICF categories were identified for ten PROMs and three traditional objective measures that were amenable to ICF linkage. The proportion of agreement ranged from 0.79 (95% CI: 0.62, 0.91) to 0.93 (0.76, 0.99) with the overall proportion of inter-linker agreement being very high 0.86 (0.82, 0.89) for the initial instruments, with 94–100% for the three additional PROMs. Thirty-four new ‘Personal Factors’ emerged to capture disease-specific qualities not elsewhere described in ICF, e.g. ‘pf_embarrassed by cough’ or ‘pf_panic/afraid when can’t get a breath’.Conclusion: This first known effort in ICF linkage of ILD has provided important revelations on the current utility of the ICF in lung disease. Results have indicated areas for meaningful assessment of ICF descriptors for lung impairment. The mapping across PROMs provides insight into possibilities of developing more streamline and precise instrumentation. Finally, familiarity with the ICF in ILD may enable clinicians to experience a smoother transition with the imminent harmonization of ICD and ICF, ICD-11.
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| 11. |
- Volkmann, E, et al.
(författare)
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Effect of varicose vein surgery on venous reflux scoring and plethysmographic assessment of venous function.
- 2008
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Ingår i: European journal of vascular and endovascular surgery : the official journal of the European Society for Vascular Surgery. - : Elsevier BV. - 1532-2165. ; 36:6, s. 731-7
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Colour duplex ultrasonography (CDU) is widely recommended before varicose vein surgery, combined with quantification of venous reflux by plethysmography where required. This study assessed venous haemodynamics before and after varicose vein surgery by venous outflow plethysmography (VOP), venous reflux plethysmography (VRP) and by adoption of a modified segmental venous reflux score (VRS). The effect of wearing one or two class I medical compression stockings was also assessed. The aim of the study was to identify parameters which reflect the outcome of treatment using medical compression stockings or surgical intervention. METHODS: 24 legs of 21 patients with superficial vein incompetence of clinical grade C(2-4a) (CEAP) were assessed before and a mean of 8 S.D. 4 months after superficial vein surgery. Investigations were CDU, as well as VOP and VRP using mercury in rubber gauges fitted either around the calf or the forefoot. Venous reflux was semi-quantitatively graded by CDU in relation to the actual vein diameter and transformed into a VRS with respect to the number of involved serial vein segments. The venous reflux rates were measured in standing patients after knee bending before and after application of one or two superimposed compression stockings (class I). RESULTS: According to VRP, one compression stocking reduced the maximum venous reflux rates (VR(max)) by about 30% which was comparable with the effect of surgery on VR(max). Two superimposed compression stockings were almost twice as effective and diminished VR(max) pre- and post operatively by around 60%. Varicose surgery reduced the maximum venous outflow rates significantly (pre-op: 166 S.D. 77 ml/min x 100 ml tissue, post op: 120 S.D. 34) and improved VRS (pre-op median 5.0 IQR: 4.5-5.5, post-op median 0.5 IQR: 0-1.0). Surgery had no effect on venous refilling time or venous reflux rates when measured without compression stockings. CONCLUSION: Venous reflux assessed by plethysmography was moderated by the use of compression stockings pre-operatively but did not reflect the outcome of surgical treatment of superficial venous reflux. Increased venous volume and venous outflow were restored to the levels of normal contralateral limbs by surgery. The VRS decreased considerably following surgery, reflecting the effect of surgical treatment on the number of incompetent venous segments. Changes in this parameter did not correlate with any of the plethysmographic measurements.
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| 12. |
- Volkmann, J, et al.
(författare)
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Selecting deep brain stimulation or infusion therapies in advanced Parkinson's disease : an evidence-based review
- 2013
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Ingår i: Journal of Neurology. - : Springer Science and Business Media LLC. - 0340-5354 .- 1432-1459. ; 260:11, s. 2701-2714
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Tidskriftsartikel (refereegranskat)abstract
- Motor complications in Parkinson’s disease (PD) result from the short half-life and irregular plasma fluctuations of oral levodopa. When strategies of providing more continuous dopaminergic stimulation by adjusting oral medication fail, patients may be candidates for one of three device-aided therapies: deep brain stimulation (DBS), continuous subcutaneous apomorphine infusion, or continuous duodenal/jejunal levodopa/carbidopa pump infusion (DLI). These therapies differ in their invasiveness, side-effect profile, and the need for nursing care. So far, very few comparative studies have evaluated the efficacy of the three device-aided therapies for specific motor problems in advanced PD. As a result, neurologists currently lack guidance as to which therapy could be most appropriate for a particular PD patient. A group of experts knowledgeable in all three therapies reviewed the currently available literature for each treatment and identified variables of clinical relevance for choosing one of the three options such as type of motor problems, age, and cognitive and psychiatric status. For each scenario, pragmatic and (if available) evidence-based recommendations are provided as to which patients could be candidates for either DBS, DLI, or subcutaneous apomorphine.
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| 13. |
- Andréasson, Kristofer, et al.
(författare)
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Disease Features and Gastrointestinal Microbial Composition in Patients with Systemic Sclerosis from Two Independent Cohorts
- 2022
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Ingår i: ACR Open Rheumatology. - : Wiley. - 2578-5745. ; 4:5, s. 417-425
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The study objective was to examine alterations in gastrointestinal (GI) microbial composition in patients with systemic sclerosis (SSc) and to investigate the relationship between SSc features and GI microbiota using two independent, international cohorts. Methods: Prospective patients with SSc from Lund University (LU), Sweden, from the University of California, Los Angeles (UCLA), United States, and control subjects provided stool specimens for 16S ribosomal RNA sequencing. Alpha and beta diversity analyses were performed. Multivariate negative binomial models identified differentially abundant genera between groups. Results: Patients from LU with SSc (n = 106) with recent SSc diagnosis (median disease duration 2.0 years) had lower abundance of commensal genera (eg, Faecalibacterium) and higher abundance of pathobiont genera (eg, Desulfovibrio) than LU-controls (n = 85). Patients from UCLA with SSc (n = 71) had a similar prevalence of females, a similar body mass index, and similar age but an increased disease duration (median 7.1 years) compared with patients from LU with SSc. Factors associated with beta diversity in patients with SSc from both LU and UCLA included disease duration (P = 0.0016), interstitial lung disease (P = 0.003), small intestinal bacterial overgrowth (P = 0.002), and immunosuppression use (P = 0.014). In multivariable analysis, the UCLA-SSc cohort had higher abundance of specific pathobiont genera (eg, Streptococcus) compared with the LU-SSc cohort. Conclusion: Enrichments and depletions in certain microbial genera were observed in patients recently diagnosed with SSc, suggesting that dysbiosis is present in early SSc. Specific disease features were independently associated with fecal microbial composition in both cohorts. After controlling for these factors, the abundance of several pathobiont bacteria differed between the cohorts, suggesting that environmental factors, along with disease manifestations, should be considered in future SSc studies.
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| 14. |
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| 15. |
- Jatuzis, D, et al.
(författare)
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Evaluation of posterior cerebral artery blood flow with transcranial Doppler sonography : value and risk of common carotid artery compression.
- 2000
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Ingår i: Journal of Clinical Ultrasound. - 0091-2751 .- 1097-0096. ; 28:9, s. 452-460
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Investigations of the posterior cerebral arteries (PCA) by transcranial Doppler sonography (TCD) may be less reliable than investigations of the anterior part of the circle of Willis. Nevertheless, a true PCA may be identified by manual compression of the proximal common carotid artery (CCA) during TCD. Therefore, we used CCA compression in clinically indicated TCD studies and assessed retrospectively its risks and prospectively its benefits for PCA evaluations.METHODS: Using the transtemporal approach, we prospectively assessed flow velocities in posteriorly located blood vessels in 180 consecutive patients before and during CCA compression. The complications of CCA compression were retrospectively reviewed in all 3,383 clinical TCD investigations performed over an 8-year period.RESULTS: Decreased flow velocities during ipsilateral CCA compression occurred in 17% of patients. A PCA-like vessel with perfusion from the carotid artery or PCA supply from the carotid circulation was unmasked. Mixed distal PCA support by the posterior communicating artery and proximal PCA could not be shown by TCD. Transient cerebral symptoms occurred in less than 0.4% of the 3,383 retrospectively reviewed TCD investigations; no other adverse effects were seen.CONCLUSIONS: TCD without CCA compression may lead to false identification of the PCA. Since transient cerebral symptoms during CCA compression are rare, CCA compression can be used when a clinical TCD investigation of intracranial collateral blood flow compensation is indicated or when the identification of a cerebral artery is uncertain.
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| 16. |
- Nogueira, E, et al.
(författare)
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A Non-Synonymous Point Mutation in a WD-40 Domain Repeat of EML5 Leads to Decreased Bovine Sperm Quality and Fertility
- 2022
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Ingår i: Frontiers in cell and developmental biology. - : Frontiers Media SA. - 2296-634X. ; 10, s. 872740-
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Tidskriftsartikel (refereegranskat)abstract
- This study is part of a concerted effort to identify and phenotype rare, deleterious mutations that adversely affect sperm quality, or convey high developmental and fertility potential to embryos and ensuing progeny. A rare, homozygous mutation in EML5 (EML5R1654W), which encodes a microtubule-associated protein with high expression in testis and brain was identified in an Angus bull used extensively in artificial insemination (AI) for its outstanding progeny production traits. The bull’s fertility was low in cross-breeding timed AI (TAI) (Pregnancy/TAI = 25.2%; n = 222) and, in general, AI breeding to Nellore cows (41%; n = 822). A search of the 1,000 Bull Genomes Run9 database revealed an additional 74 heterozygous animals and 8 homozygous animals harboring this exact mutation across several different breeds (0.7% frequency within the 6,191 sequenced animals). Phenotypically, spermatozoa from the homozygous Angus bull displayed prominent piriform and tapered heads, and outwardly protruding knobbed acrosomes. Additionally, an increased retention of EML5 was also observed in the sperm head of both homozygous and heterozygous Angus bulls compared to wild-type animals. This non-synonymous point mutation is located within a WD40 signaling domain repeat of EML5 and is predicted to be detrimental to overall protein function by genomic single nucleotide polymorphism (SNP) analysis and protein modeling. Future work will examine how this rare mutation affects field AI fertility and will characterize the role of EML5 in spermatogenesis.
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| 17. |
- Odin, Per, et al.
(författare)
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Viewpoint and practical recommendations from a movement disorder specialist panel on objective measurement in the clinical management of Parkinson's disease
- 2018
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Ingår i: Npj Parkinson's Disease. - : Springer Science and Business Media LLC. - 2373-8057. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- Motor aspects of Parkinson's disease, such as fluctuations and dyskinesia, can be reliably evaluated using a variety of "wearable" technologies, but practical guidance on objective measurement (OM) and the optimum use of these devices is lacking. Therefore, as a first step, a panel of movement disorder specialists met to provide guidance on how OM could be assessed and incorporated into clinical guidelines. A key aspect of the incorporation of OM into the management of Parkinson's disease (PD) is defining cutoff values that separate "controlled" from "uncontrolled" symptoms that can be modified by therapy and that relate to an outcome that is relevant to the person with PD (such as quality of life). Defining cutoffs by consensus, which can be subsequently tested and refined, is the first step to optimizing OM in the management of PD. OM should be used by all clinicians that treat people with PD but the least experienced may find the most value, but this requires guidance from experts to allow non-experts to apply guidelines. While evidence is gained for devices that produce OM, expert opinion is needed to supplement the evidence base.
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| 18. |
- Schönhense, G., et al.
(författare)
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Time-of-flight photoelectron momentum microscopy with 80-500 MHz photon sources : Electron-optical pulse picker or bandpass pre-filter
- 2021
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Ingår i: Journal of Synchrotron Radiation. - 0909-0495. ; 28, s. 1891-1908
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Tidskriftsartikel (refereegranskat)abstract
- The small time gaps of synchrotron radiation in conventional multi-bunch mode (100-500 MHz) or laser-based sources with high pulse rate (∼80 MHz) are prohibitive for time-of-flight (ToF) based photoelectron spectroscopy. Detectors with time resolution in the 100 ps range yield only 20-100 resolved time slices within the small time gap. Here we present two techniques of implementing efficient ToF recording at sources with high repetition rate. A fast electron-optical beam blanking unit with GHz bandwidth, integrated in a photoelectron momentum microscope, allows electron-optical 'pulse-picking' with any desired repetition period. Aberration-free momentum distributions have been recorded at reduced pulse periods of 5 MHz (at MAX II) and 1.25 MHz (at BESSY II). The approach is compared with two alternative solutions: A bandpass pre-filter (here a hemispherical analyzer) or a parasitic four-bunch island-orbit pulse train, coexisting with the multi-bunch pattern on the main orbit. Chopping in the time domain or bandpass pre-selection in the energy domain can both enable efficient ToF spectroscopy and photoelectron momentum microscopy at 100-500 MHz synchrotrons, highly repetitive lasers or cavity-enhanced high-harmonic sources. The high photon flux of a UV-laser (80 MHz, <1 meV bandwidth) facilitates momentum microscopy with an energy resolution of 4.2 meV and an analyzed region-of-interest (ROI) down to <800 nm. In this novel approach to 'sub-μm-ARPES' the ROI is defined by a small field aperture in an intermediate Gaussian image, regardless of the size of the photon spot.
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| 19. |
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| 20. |
- Suarez, Catherine, et al.
(författare)
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The Malarial Serine Protease SUB1 Plays an Essential Role in Parasite Liver Stage Development
- 2013
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Ingår i: PLoS Pathogens. - : Public Library of Science. - 1553-7366 .- 1553-7374. ; 9:12
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Tidskriftsartikel (refereegranskat)abstract
- Transmission of the malaria parasite to its vertebrate host involves an obligatory exoerythrocytic stage in which extensive asexual replication of the parasite takes place in infected hepatocytes. The resulting liver schizont undergoes segmentation to produce thousands of daughter merozoites. These are released to initiate the blood stage life cycle, which causes all the pathology associated with the disease. Whilst elements of liver stage merozoite biology are similar to those in the much better-studied blood stage merozoites, little is known of the molecular players involved in liver stage merozoite production. To facilitate the study of liver stage biology we developed a strategy for the rapid production of complex conditional alleles by recombinase mediated engineering in Escherichia coli, which we used in combination with existing Plasmodium berghei deleter lines expressing Flp recombinase to study subtilisin-like protease 1 (SUB1), a conserved Plasmodium serine protease previously implicated in blood stage merozoite maturation and egress. We demonstrate that SUB1 is not required for the early stages of intrahepatic growth, but is essential for complete development of the liver stage schizont and for production of hepatic merozoites. Our results indicate that inhibitors of SUB1 could be used in prophylactic approaches to control or block the clinically silent pre-erythrocytic stage of the malaria parasite life cycle.
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| 21. |
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| 22. |
- Zachrisson, Helene, et al.
(författare)
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Changes in middle cerebral artery blood flow after carotid endarterectomy as monitored by transcranial Doppler.
- 2002
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Ingår i: Journal of Vascular Surgery. - 0741-5214 .- 1097-6809. ; 36:2, s. 285-90
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: By using transcranial Doppler (TCD) it is possible to measure blood flow velocities within the circle of Willis. In this study, TCD was performed before and after carotid endarterectomy (CEA) with the aim to describe cerebral hemodynamics after normalization of the carotid artery blood flow.METHODS: Thirty CEA patients were consecutively entered into the TCD study, whereas 15 patients were referred for postoperative TCD for various clinical reasons. All 45 patients were investigated by using TCD: first preoperatively, then during the first few days after CEA before discharge from the hospital, and finally 3 to 12 months later. In addition, all patients underwent duplex investigation of the internal carotid artery the day before surgery and 3 months postoperatively. For the analysis, the patients were divided into two groups, one with (S-group), suspected postoperative neurologic complications/symptoms and another one without (C-group). Six patients were assigned to the S-group and 37 to the C-group, the latter including two patients who underwent bilateral CEAs.RESULTS: In the whole study group,a significant postoperative increase in systolic flow velocity was recorded bilaterally in the middle cerebral artery (MCA) as measured some days after surgery. The patients in the S-group showed high blood flow velocities mainly in the MCA on the ipsilateral side. A contralateral flow velocity increase did not occur in patients with very severe contralateral stenosis or occlusion (n = 9) if the late follow-up investigation was chosen as a reference value. Twenty patients in the C-group formed a subgroup with high blood pressure and/or headache postoperatively (CB-group) The other 19 patients were referred to as the CA-group. The CB- and S-groups showed more pronounced vessel disease in internal carotid artery on the contralateral side combined with lower collateral capacity in the circle of Willis compared to the CA-group. In the S-group the mean +/- standard deviation peak systolic velocity in ipsilateral MCA increased from a preoperative value of 0.71 +/- 0.22 m/sec to 2.23 +/- 0.72 m/sec (P <.005). In the CB-group, we observed a bilateral MCA blood flow velocity increase from 0.72 +/- 0.18 to 1.35 +/- 0.56 m/sec (P <.0001) on the ipsilateral side and from 0.82 +/- 0.37 to 1.28 +/- 0.66 m/sec (P < 0.001) on the contralateral side. In the CA-group, we observed minor bilateral blood flow velocity increases in the MCA, from 0.79 +/- 0.25 m/sec to 1.03 +/- 0.33 m/sec on the ipsilateral (P <.001) and from 0.70 +/- 0.17 m/sec to 0.93 +/- 0.26 m/sec on the contralateral side (P <.005). At the follow-up 3 to 12 months after surgery, the MCA flow velocities had returned to normal.CONCLUSIONS: Soon after surgery, blood flow velocity increases often bilaterally in the MCA. However a contralateral flow velocity increase did not occur in patients with very severe contralateral stenosis or occlusion if the late follow-up investigation was chosen as a reference value. The clinical significance of bilateral flow velocity increases is uncertain, but very high blood flow velocities might be a signal for cerebrovascular hyperperfusion. In those patients, increased postoperative surveillance is recommended.
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| 23. |
- Zachrisson, Helene, et al.
(författare)
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Influence of poststenotic collateral pressure on blood flow velocities within high-grade carotid artery stenosis : differences between morphologic and functional measurements.
- 2001
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Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214 .- 1097-6809. ; 34:2, s. 263-8
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The driving force for blood flow through a high-grade stenosis in the internal carotid artery can be expressed as the pressure gradient over the stenosis itself, which, however, might be reduced by the back pressure exerted by distal collateral vessels. Theoretically the maximum blood flow velocity as a measure of the functional grade of obstruction may therefore be lower than what is expected from morphologic gradations of the stenosis. This study was designed to test prospectively the influence of intracranial collateral vessels on blood flow velocities within high-grade internal carotid artery stenoses.PATIENTS AND METHODS: Forty-five consecutive patients (age 66 +/- 11) with high-grade internal carotid artery stenoses were investigated before and during carotid endarterectomy. The preoperative investigations included duplex ultrasound scanning of the neck vessels, transcranial Doppler scanning for assessment of collateral flow to the middle cerebral artery and angiography. Carotid endarterectomy was performed with patients under deep general anesthesia without a shunt. Systolic and diastolic internal carotid artery blood pressures were measured before and during intraoperative cross-clamping (ie, stump pressure) of the carotid arteries.RESULTS: Within high-grade internal carotid artery stenoses, maximum systolic and end-diastolic blood flow velocities showed a significant inverse correlation to the corresponding systolic and diastolic stump blood internal carotid artery blood pressures. All patients with spontaneous collateral flow to the ipsilateral anterior part of the circle of Willis were divided into a group with relatively high and another one with low end-diastolic blood flow velocities. The stump pressure was significantly lower in patients with high end-diastolic blood flow velocities in spite of the fact that the mean angiographic grade of stenosis did not differ significantly between the groups.CONCLUSIONS: Flow velocities within a high-grade internal carotid artery stenosis are inversely dependent on the stump pressure, that is the poststenotic collateral perfusion pressure. This should be taken into consideration in case of discrepancies between angiography and ultrasound outcome.
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| 24. |
- Zachrisson, Helene, et al.
(författare)
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Middle cerebral artery circulation during carotid surgery. A transcranial Doppler study.
- 2000
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Ingår i: Scandinavian Cardiovascular Journal. - 1401-7431 .- 1651-2006. ; 34:6, s. 597-602
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Perioperative carotid cross-clamping might induce low stump pressures as well as hypoperfusion of the middle cerebral artery. In this study blood flow velocities in the middle cerebral artery were compared with intraoperative measurements of the poststenotic carotid blood pressure.DESIGN: Forty-one patients with internal carotid artery stenosis were operated on without shunting, under general anesthesia. Poststenotic carotid pressures and middle cerebral artery flow velocities were measured before and during cross-clamping. The hemodynamic responses to preoperative carotid compressions and intraoperative cross-clamping were evaluated.RESULTS: In seven patients the poststenotic carotid blood pressure decreased on clamping despite unchanged or even increased middle cerebral artery blood flow velocities. In all other patients, pressure changes were significantly correlated to the decrease in middle cerebral artery blood flow velocities. Autoregulatory blood flow velocity responses after preoperative common carotid artery compression were not reproducible by cross-clamping.CONCLUSIONS: Stump blood pressure measurements may not reflect middle cerebral artery perfusion in about 20% of thrombendarterectomies performed under general anesthesia. A possible explanation might be dimished cerebral autoregulation and changes in collateral flow distributions.
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| 25. |
- Zachrisson, Helene, et al.
(författare)
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Selectivity of superficial vein occlusion at the ankle and calf level : a methodological study in healthy volunteers.
- 1998
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Ingår i: Clinical Physiology. - 0144-5979 .- 1365-2281. ; 18:1, s. 55-60
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Tidskriftsartikel (refereegranskat)abstract
- Judgement of deep venous function may be necessary before surgery for superficial vein incompetence is performed. Assessment of deep venous function needs selective entrapment of superficial venous compartments between the ankle and knee, which may not be guaranteed if conventional tourniquets are used. This study was, therefore, aimed at modifying the technique of selective compression of superficial vein compartments. Twenty apparently normal legs of 10 volunteers were investigated on two study days. The subjects were in a supine position with the feet resting 30 cm above heart level. Ankle cuffs (3 cm wide) were placed just above the malleoli and stepwise inflated with air. The steady-state venous volume of the forefoot as a function of the pressure within the ankle cuff was measured with a mercury-in-rubber strain gauge. The maximum venous outflow velocity from the foot was also measured at each cuff pressure step after the addition of conventional thigh vein occlusion. The same protocol was used on the second study day: calf cuffs (3 cm wide) were then used instead of the ankle cuffs. In the forefoot, venous volume increased and the maximum venous outflow velocity decreased significantly either at ankle cuff pressures > 30 mmHg or at calf cuff pressures of > 60 mmHg. By using small cuffs, selective superficial vein occlusion seems to occur at cuff pressures ranging between 10 and 30 mmHg (ankle) and between 30 and 60 mmHg (calf), provided the feet are 30 cm above heart level. Higher cuff pressures seem to interact with deep venous function.
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