The results of laboratory analyses are affected by pre-analytical variables, and in particular can platelets be activated by shear handling stress and secrete granular substances. We therefore ...evaluated the effect of centrifugation speed and time on pre-analytical platelet activation.
Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean platelet volume (MPV), immature platelet fraction (IPF), and platelet distribution width (PDW) were measured. Platelet aggregation in platelet-rich plasma induced by arachidonic acid (AA), ADP or thrombin receptor activator peptide-6 (TRAP) was tested by 96-well aggregometry.
The median percentage of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% interquartile range (IQR), 38%-53% and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), p<0.001. Platelet count in plasma samples decreased with increasing speed but platelets were only completely removed if plasma was re-centrifuged. In platelet-rich plasma, increasing centrifugation speed significantly increased platelet yield but decreased contamination from other blood cells, platelet composition was altered as platelet parameters (MPV, IPF, and PDW) was lowered. Platelet aggregation was not affected by the centrifugation speed platelet-rich plasma was prepared.
Proportional to centrifugation speed, platelets in plasma and platelet-rich plasma were activated with centrifugation speed, cell content and composition changed while platelet aggregation was unaltered.
The increased rice production in the Mekong Delta during the last two decades has improved agricultural income and reduced poverty, but it has also had negative impacts on the environment and human ...health. This study shows that integrated rice–fish farming and integrated pest management strategies provide sustainable options to intensive rice farming, because of a more balanced use of multiple ecosystem services that benefit the farmers’ health, economy and the environment. The study investigates and compares farming strategies among 40 rice and 20 rice–fish farmers in two locations in the Mekong Delta. Production costs and income are used to compare the systems’ financial sustainability. The farmers’ perception on how their farming practices influence on ecosystem services and their livelihoods are used as an indication of the systems’ ecological and social sustainability. Although rice–fish farmers used lower amount of pesticides and fertilisers than rice farmers, there were no statistical differences in their rice yields or net income. Rice was seen as the most important ecosystem service from rice fields and related wetlands, but also several other ecosystem services, such as water quality, aquatic animals, plants, habitats, and natural enemies to pests, were seen as important to the farmers’ livelihoods and wellbeing. All farmers perceived that there had been a general reduction in all these other ecosystem services, due to intensive rice farming during the last 15 years, and that they will continue to decline. The majority of the farmers were willing to reduce their rice yields slightly for an improved quality of the other ecosystem services.
Enumeration of stem cells is essential in the management of peripheral blood stem cell (PBSC) harvest. An alternative to the gold standard flow cytometric CD34+ stem cell count is the fully automated ...hematopoietic stem cell (HPC) count on the Sysmex XN hematology analyzer.
Eighty-nine patients and healthy stem cell donors who underwent PBSC harvest were included in the study. Stem cells were enumerated in pre-harvest peripheral blood and the apheresis yield by both flow cytometric CD34+ stem cell enumeration and by the Sysmex XN HPC count.
The Sysmex HPC concentration overestimated the CD34+ stem cell concentration by a ratio of 1.3 in average. The agreement between the two methods was poor at concentration <40 stem cells/μL (Bias: 45 %, 95 % limits of agreement: -71 - 160 %). CD34+ stem cell concentration and HPC concentration correlated well in pre-harvest peripheral blood (R=0.73, slope=0.96). We established a positive cut off >43.5 HPC/μL, where PBSC harvest can be initiated. And a negative cut off <16.5 HPC/μL, where harvest should be postponed or other mobilizing regimens or bone marrow harvest should be considered. 33 % of measurements were in between the negative and positive cut-off and would require a supplementary CD34+ cell count.
Although Sysmex HPC count correlates well with CD34+ cell count in peripheral blood, the agreement between the two methods is poor, especially at low concentrations, namely in the clinical decision range. Sysmex HPC count as a surrogate for CD34+ cell count should, therefore, be used with caution.
Background
Lymphocyte neogenesis from primary lymphoid organs is essential for a successful reconstitution of immunity after allogeneic hematopoietic stem cell transplantation (HSCT). This ...single-center retrospective study aimed to evaluate T cell receptor excision circles (TREC) and kappa-deleting recombination excision circles (KREC) as surrogate markers for T and B cell recovery, as predictors for transplantation-related outcomes in adult acute myeloid leukemia (AML) patients.
Methods
Ninety adult patients diagnosed with AML and treated with HSCT between 2010 and 2015 were included in the study. TREC and KREC levels were measured by quantitative PCR at 1, 3, 6, and 12 months after transplantation.
Results
Overall, excision circle levels increased between 3 and 6 months post-HSCT for TREC (p = 0.005) and 1 and 3 months for KREC (p = 0.0007). In a landmark survival analysis at 12 months post-HSCT, TREC levels were associated with superior overall survival (HR: 0.52, 95% CI: 0.34 - 0.81, p = 0.004). The incidence of viral infections within the first 100 days after transplantation was associated with lower TREC levels at 6 months (p = 0.0002). CMV reactivation was likewise associated with lower TREC levels at 6 months (p = 0.02) post-HSCT. KREC levels were not associated with clinical outcomes in statistical analyzes.
Conclusions
Results from the present study indicate that TREC measurement could be considered as part of the post-HSCT monitoring to identify AML patients with inferior survival after transplantation. Further prospective studies are warranted to validate these findings.
Diagnostic Vaccination in Clinical Practice Hansen, Anette Tarp; Söderström, Anna; Jørgensen, Charlotte Sværke ...
Frontiers in immunology,
09/2021, Letnik:
12
Journal Article
Recenzirano
Odprti dostop
Testing the antibody response to vaccination (diagnostic vaccination) is crucial in the clinical evaluation of primary immunodeficiency diseases. Guidelines from the American Academy of Allergy, ...Asthma & Immunology (AAAAI) provide detailed recommendations for diagnostic vaccination with pure pneumococcal polysaccharide vaccines (PPV). However, the degree of compliance with these guidelines and the utility of the guidelines in actual practice are undescribed. To address this, we systematically evaluated diagnostic vaccination in adult patients with suspected primary immunodeficiency diseases in a single tertiary center from 2011 to 2016 (
= 229). We found that full compliance with the AAAAI guidelines was achieved for only 39 patients (17%), suggesting that the guidelines are not easy to follow. Worse, interpretation according to the guidelines was heavily influenced by which serotype-specific antibodies that were used for the evaluation. We found that the arbitrary choices of serotype-specific antibodies could change the fraction of patients deemed to have 'adequate immunity' by a factor of four, exposing an inherent flaw in the guidelines. The flaw relates to dichotomous principles for data interpretation under the AAAAI guidelines. We therefore propose a revised protocol for diagnostic vaccination limited to PPV vaccination, subsequent antibody measurements, and data interpretation using Z-scores. The Z-score compiles multiple individual antibody levels, adjusted for different weighting, into one single continuous variable for each patient. In contrast to interpretation according to the AAAAI guidelines, the Z-scores were robust to variations in the choice of serotype-specific antibodies used for interpretation. Moreover, Z-scores revealed reduced immunity after vaccination in the patients with recurrent pneumonia (a typical symptom of antibody deficiency) compared with control patients. Assessment according to the AAAAI guidelines failed to detect this difference. We conclude that our simplified protocol and interpretation with Z-scores provides more robust clinical results and may enhance the value of diagnostic vaccination.
Introduction
Central venous catheters (CVC) can facilitate a reliable blood flow for apheresis procedures, but the placement is time‐consuming and costly and the incidence of catheter‐related ...complications is high. Ultrasound can aid nurses to insert peripheral venous catheters (PVC), which is safer for the patients.
Methods and materials
We evaluated the use of CVC vs PVC for all apheresis procedures 3 years after the implementation of structured training of apheresis nurses to perform ultrasound‐guided PVC. Ultrasound can visualize the needle tip and target vessel dynamically and guide peripheral venous catheterization with an increased success rate. Time consumption for PVC insertion was measured.
Results
In 10 months, we performed 1294 apheresis procedures on 227 patients, where 97.4% were performed with PVC. Hundred percent of extracorporeal photophoresis (off‐line ECP) and peripheral blood stem cell collections on adults were performed with PVC. Patients who were treated with CVC (n = 8) were either children, had poor peripheral blood flow due to dehydration or admitted to an intensive care unit and had CVC for other reasons. Time consumption for PVC placement with ultrasound was 11 minutes on average.
Conclusion
Training of apheresis nurses in ultrasound‐guided peripheral venous catheterization can enable close to 100% of apheresis procedures to be performed by PVC.
Results from previous studies regarding platelet function in liver cirrhosis are discordant. The aim was to investigate platelet activation and platelet aggregation in patients with alcoholic liver ...cirrhosis. We included 27 patients with alcoholic liver cirrhosis and 22 healthy individuals. A recently established flow cytometric approach was used to measure platelet activation and platelet aggregation independent of sample platelet count. Platelet aggregation was further investigated using light transmission aggregometry (LTA) (for platelet count >100 × 10
9
/L). Platelet agonists were adenosine diphosphate, thrombin receptor-activating peptide, arachidonic acid, collagen, and collagen-related peptide. Patients had lower median platelet count than healthy individuals, 125 × 10
9
/L (interquartile range IQR 90˗185) versus 240 × 10
9
(IQR 204˗285), p < 0.001. Platelet activation levels in stimulated samples were lower in patients versus healthy individuals, e.g., after collagen-related peptide stimulation, the median percentage of platelets positive for activated glycoprotein IIb/IIIa was 85% (IQR 70-94) in patients versus 97% (IQR 94-99) in healthy individuals, p < 0.001; lower platelet activation capacity being associated with low platelet count and Child-Pugh class B/C cirrhosis. Flow cytometric platelet aggregation was reduced in patients for collagen-related peptide and for adenosine diphosphate, e.g., platelet aggregation (mean ± standard deviation) was 57% ± 4 in patients versus 70% ± 1 in healthy individuals for collagen-related peptide, p = 0.01. Light LTA showed reduced collagen-induced platelet aggregation in some patients compared with healthy individuals. In conclusion, platelet function was reduced in some patients with alcoholic liver cirrhosis and the severity was associated with platelet count and severity of liver cirrhosis.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Dabigatran is an oral anticoagulant and a reversible inhibitor of thrombin. Further, dabigatran might affect platelet function through a direct effect on platelet thrombin receptors. The aim was to ...investigate the effect of dabigatran on platelet activation and platelet aggregation. Healthy donor blood was incubated with dabigatran 0, 50, 500 ng/mL, corresponding to the therapeutic range of dabigatran peak plasma concentrations, and 10,000 ng/mL comprising a supra-therapeutic dabigatran plasma level. Platelet aggregation was tested with 96-well aggregometry. Flow cytometry was used to test platelet activation and platelet thrombin receptor expression (SPAN-12 and WEDE-15 expression). Agonists were thrombin, thrombin receptor-activating peptide, protease-activated receptor-4 agonist, collagen, collagen-related peptide, arachidonic acid, and adenosine diphosphate. All concentrations of dabigatran fully inhibited platelet aggregation for thrombin up to 2 IU/mL, while dabigatran did not affect platelet aggregation by other agonists. Platelet activation (percentage of platelets positive for activated GPIIb/IIIa, CD63, P-selectin) was reduced after thrombin stimulation in samples with dabigatran levels ≥500 ng/mL. After stimulation with thrombin, the percentage of activated GPIIb/IIIa-positive platelets was 99.8 ± 0.2% without dabigatran, 14.7 ± 4.7% with 500 ng/mL dabigatran, and 4.2 ± 0.2% with 10,000 ng/mL dabigatran, both p < 0.001 when compared to samples without dabigatran. Also, the receptor expression of GPIIb/IIIa, CD63, and P-selectin were reduced after dabigatran treatment. The expression of thrombin receptors was reduced at dabigatran on ≥ 500 ng/mL. In conclusion, dabigatran exclusively inhibits thrombin-induced platelet activation and aggregation with a dose-dependent response. Platelet stimulation with other agonists was not affected by dabigatran.
To evaluate the feasibility of a lifestyle program for early intervention in patients with COPD in a primary care population.
The study was performed in a Primary Health Care Centre in Western ...Sweden. During a four-week period, all smokers between 40-70 years of age were invited to answer a questionnaire and to perform spirometry. The intervention program included a specially designed smoking cessation program and programs for physical activity and diet.
84 smokers were included. 42% fulfilled the criteria for COPD. All of the COPD patients were in GOLD stage I and II. Among the COPD subjects, 38% were underweight and 56% had a low fat-free mass - both together indicating malnutrition and the need for nutritional treatment. By the end of the intervention program, 47% of the COPD patients had stopped smoking.
The intervention program was feasible and effective with a very high smoking cessation rate.
To assess the primary care management of chronic obstructive pulmonary disease (COPD) in relation to COPD guidelines.
A postal questionnaire was sent out to all Primary Health Care Centres (PHCCs) in ...western Sweden (n=232). The response rate was 75%.
A majority of the PHCCs had a nurse and physician responsible for COPD care. They used spirometry equipment regularly, but only 50% reported that they calibrated it at least weekly. Less than 30% of the PHCCs reported access to a dietician, occupational therapist or physiotherapist. There was a structured smoking cessation program in 50% of the PHCCs. Larger PHCCs were more likely to use spirometry equipment regularly and to have specific personnel for COPD care.
There is a need to establish structured programs for COPD care including smoking cessation programs for COPD patients with special trained staff. Larger PHCCs have a better infrastructure for providing guideline-defined COPD care.
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