The effects of freeze–thaw on β-trace protein and β2-microglobulin assays after long-term sample storage

Abstract Background The pervasiveness of doping and findings of anti-doping corruption threaten weightlifting’s position at the 2024 Olympic Games. Analysing the practices of doping in weightlifters could identify patterns in doping that assist in future detection. Methods We analysed publicly available data on sanctioned athletes/support personnel from the International Weightlifting Federation between 2008 and 2019 and announced retrospective Anti-Doping Rule Violations (ADRVs) from the 2008 and 2012 Olympic Games. Results There were 565 sanctions between 2008 and 2019 of which 82% related to the detection of exogenous Anabolic Androgenic Steroid (AAS) metabolites and markers indicating endogenous AAS usage. The detection of exogenous AAS metabolites, markers of endogenous AAS usage and other substance metabolites varied by IWF Continental Federation (p ≤ 0.05) with Europe (74%, 11%, 15%) and Asia (70%, 15%, 15%) showing a higher detection of exogenous AAS compared to Pan America (37%, 30%, 33%) and Africa (50%, 17%, 33%). When looking at the 10 most detected substances, the nations with the highest number of sanctions (range 17–35) all had at least one overrepresented substance that accounted for 38–60% of all detected substances. The targeted re-analysis of samples from the 2008 and 2012 Olympic Games due to the discovery of long-term metabolites for exogenous AAS resulted in 61 weightlifters producing retrospective ADRVs. This includes 34 original medallists (9 gold, 10 silver and 15 bronze), the highest of any sport identified by Olympic Games sample re-testing. The exogenous AAS dehydrochloromethyltestosterone and stanozolol accounted for 83% of detected substances and were present in 95% of these samples. Conclusion Based on these findings of regional differences in doping practices, weightlifting would benefit from the targeted testing of certain regions and continuing investment in long-term sample storage as the sensitivity and specificity of detection continues to improve.

Download Full-text

Amino acid sequence of a modified β2-microglobulin in renal failure patient urine and long-term dialysis patient blood

Clinica Chimica Acta ◽

10.1016/0009-8981(95)06039-g ◽

1995 ◽

Vol 236 (2) ◽

pp. 135-144 ◽

Cited By ~ 5

Author(s):

Tomoko Momoi ◽

Masami Suzuki ◽

Koiti Titani ◽

Shuichi Hisanaga ◽

Hiroshi Ogawa ◽

...

Keyword(s):

Renal Failure ◽

Amino Acid ◽

Amino Acid Sequence ◽

Dialysis Patient ◽

Renal Failure Patient ◽

Β2 Microglobulin

Download Full-text

Differential arthropod responses to warming are altering the structure of Arctic communities

Royal Society Open Science ◽

10.1098/rsos.171503 ◽

2018 ◽

Vol 5 (4) ◽

pp. 171503 ◽

Cited By ~ 20

Author(s):

Amanda M. Koltz ◽

Niels M. Schmidt ◽

Toke T. Høye

Keyword(s):

Community Composition ◽

Primary Productivity ◽

Species Interactions ◽

Ecosystem Processes ◽

The Arctic ◽

Individual Species ◽

Freeze Thaw ◽

Compositional Changes ◽

Arctic Communities

The Arctic is experiencing some of the fastest rates of warming on the planet. Although many studies have documented responses to such warming by individual species, the idiosyncratic nature of these findings has prevented us from extrapolating them to community-level predictions. Here, we leverage the availability of a long-term dataset from Zackenberg, Greenland (593 700 specimens collected between 1996 and 2014), to investigate how climate parameters influence the abundance of different arthropod groups and overall community composition. We find that variation in mean seasonal temperatures, winter duration and winter freeze–thaw events is correlated with taxon-specific and habitat-dependent changes in arthropod abundances. In addition, we find that arthropod communities have exhibited compositional changes consistent with the expected effects of recent shifts towards warmer active seasons and fewer freeze–thaw events in NE Greenland. Changes in community composition are up to five times more extreme in drier than wet habitats, with herbivores and parasitoids generally increasing in abundance, while the opposite is true for surface detritivores. These results suggest that species interactions and food web dynamics are changing in the Arctic, with potential implications for key ecosystem processes such as decomposition, nutrient cycling and primary productivity.

Download Full-text

MO921PROGNOSTIC OUTCOMES OF TRANSPLANTED KIDNEY USING SOLUBLE CD30 AND Β2- MICROGLOBULIN

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfab112.003 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Ahmed Abo omar ◽

Gamal Saadi

Keyword(s):

Acute Rejection ◽

Graft Survival ◽

Patient Group ◽

The Other ◽

Kidney Graft ◽

Post Transplantation ◽

Β2 Microglobulin ◽

Transplanted Kidney ◽

Successful Transplantation

Abstract Background and Aims Transplantation is the first successful modality of renal replacement therapy (RRT) for irreversible chronic kidney disease (CKD; stage 5). Identifying additional factors associated with poor long-term prognosis after transplantation may provide clues regarding the pathophysiological mechanisms involved in allograft failure and identify high-risk patients who may benefit from additional monitoring or interventions. Successful kidney transplantation results in a substantial decrease in β2M levels, but a delayed decrease or increasing levels after transplantation may serve as a marker of acute rejection or inflammation. Several reports show that elevated sCD30 levels, pre and post transplantation are associated with a poor prognosis for long term kidney graft survival. These studies found higher CD30 levels in allograft recipients and a good predictor of impending acute rejection. The aim of the work is to study the prognostic outcomes of transplanted kidney using CD30 and β2-Microglobulin Method prospective study was conducted in nephrology unit –internal medicine department at Tanta and Kasr El Ainy university ,over 1 year.20 patients subjected to primary Tx.participated in this study.Cd30 and β2M.at day -1,2weeks and 3 months,with clinical follow up after 1 year to detect graft survival Results At day -1,level of cd30 was higher in rejection group than the other patient group.2 weeks post transplantation ,level of cd30 was higher in rejection group than the other patient group and at 3 monthes post transplantation level of cd30 was higher in rejection group than the other patient group,and these differences are statistically highly significant.(p values :0.003 ,0.005 and 0.002 respectively) Successful transplantation leads to significant decrease in serum cd30 at 2 weeks post tx.(P1 <0.005) and at 3 monthes post tx. (P1<0.001) although in rejection group, significant decrease in cd30 was at 2 weeks post tx.only(P1<0.005) and at 3 monthes serum cd30 began to rise again with( P1 0.157). At day -1,level of β2microglobulin was higher in rejection group than the other patient groupwith statistically significant difference (p. 0.01).2 weeks post transplantation ,level of β2microglobulin was higher in rejection group than the other patient groupbut statistically not significant(p. 0.18 ) and at 3 monthes post transplantation level of β2microglobulin was higher in rejection group than the other patient group but statistically non significant(p. 0.18 ). Successful transplantation leads to significant decrease in serum β2microglobulin at 2 weeks post tx.(P1 <0.002) and at 3 monthes post tx. (P1<0.001) although in rejection group ,significant decrease in β2microglobulin was at 3 monthes post tx.only(P1<0.005) and at 2 weeks no significant decrease(p1 0.15) Conclusion pre transplantation high Cd30 and β2M is associated with poor outcome.failure of decrease of cd30 and β2M post Tx. also associated with poor outcome or infection. Successful transplantation leads to significant decrease in serum cd30 and β2M. which can be used as predictors of graft survival with better sensitivity and specificity than serum creatinin.

Download Full-text

Inverted roof insulation kits and their durability

MATEC Web of Conferences ◽

10.1051/matecconf/201816308005 ◽

2018 ◽

Vol 163 ◽

pp. 08005 ◽

Cited By ~ 1

Author(s):

Barbara Francke ◽

Robert Geryło

Keyword(s):

Water Absorption ◽

Thermal Insulation ◽

Laboratory Tests ◽

Expanded Polystyrene ◽

Insulation Layer ◽

Performance Properties ◽

Climate Conditions ◽

Freeze Thaw ◽

Moisture Increase

In the paper there was analyzed a mechanism of loss of performance properties of inverted roof insulation kits resulted by moisture increase of the insulation layers. This problem is very important in such systems because the thermal insulation is placed above the waterproofing layer and is not protected against water absorption. Abovementioned problem is more and more common in the course of building’s utilization in Polish climate conditions. Because inverted roof kits are based on extruded polystyrene (XPS) and expanded polystyrene (EPS), those materials have been used in tested samples. The results of laboratory tests showed the phenomenon and its effect on durability and sustainability of roof covering performance. It was also found that the biggest influence on the increase of moisture in the thermal insulation layer has not the long term water absorption by immersion but freeze –thaw cycles.

Download Full-text

Longitudinal Study of Proteins in Plasma and Dialysate during Continuous Ambulatory Peritoneal Dialysis (CAPD)

Peritoneal Dialysis International ◽

10.1177/089686089001000402 ◽

1990 ◽

Vol 10 (4) ◽

pp. 257-261 ◽

Cited By ~ 6

Author(s):

Gerald A. Young ◽

Albert Taylor ◽

Steven Kendall ◽

Aleck M. Brownjohn

Keyword(s):

Peritoneal Dialysis ◽

Longitudinal Study ◽

Membrane Permeability ◽

Continuous Ambulatory Peritoneal Dialysis ◽

Plasma Proteins ◽

Complement C3 ◽

Acid Glycoprotein ◽

Β2 Microglobulin ◽

Male Patients

The aim was to evaluate plasma proteins during continuous ambulatory peritoneal dialysis (CAPD) in relation to dialysis losses, membrane permeability, renal insufficiency, and time on CAPD. Ten male patients, established on CAPD for at least 14 months, were studied every 8 weeks for 56 weeks. Blood and dialysate from the morning exchange were analysed for urea, creatinine, and 7 proteins, and used to calculate dialysate to plasma concentration ratios (DIP). These ratios were not significantly changed suggesting that permeability remained constant. However, there was a trend for β2-microglobulin, creatinine, and urea to increase progressively. After 56 weeks, β2-microglobulin had increased from 27.9 to 31.3 mglL (p < 0.05) and creatinine 1006 to 1099 μmoLIL (p < 0.05) and both correlated with time on CAPD (p < 0.001). Plasma α1-acid glycoprotein, albumin, transferrin, IgG, IgA, and complement C3 were not significantly changed, although IgA and complement C3 were each negatively correlated with time on CAPD (r = −0.70 and −0.67, respectively), creatinine (r = 0.51 and −0.54), and urea (r = −0.61 and −0.61) (p < 0.001 for all). It is concluded that increases in β2-microglobulin, creatinine, and urea are not due to loss of membrane permeability but reflect a slight increase in uraemia. Long-term decreases in immunological proteins may be caused by uraemia or progressive depletion.

Download Full-text