scholarly journals New kinetic assay of complement activity using undiluted serum

1987 ◽  
Vol 10 (6) ◽  
pp. 560-565
Author(s):  
Masahiro Ueda ◽  
Shuhei Takemura ◽  
Masako Deguchi ◽  
Hideki Onodera ◽  
Shigeru Sugino ◽  
...  
Keyword(s):  
Kinetic Assay ◽  
Complement Activity ◽  
Undiluted Serum

scholarly journals The complement activity of canine serum

1957 ◽  
Vol 55 (3) ◽  
pp. 402-413 ◽  
Author(s):  
N. M. Larin ◽  
Rachel Gaddum ◽  
W. G. Orbell
Keyword(s):  
Guinea Pig ◽  
Technical Assistance ◽  
Specific Activity ◽  
Virus Antigen ◽  
Haemolytic Activity ◽  
Complement Activity ◽  
Undiluted Serum ◽  
Protein Particle ◽  
Canine Serum ◽  
Fixation Reaction

Quantitative studies have shown that the haemolytic activity of canine complement was in all essentials similar to guinea-pig complement. Canine serum which had been heated at 56° C. markedly enhanced the haemolytic activity of canine complement. The complement-enhancing power of heated canine serum was found to be increased with the concentration of serum up to 20%. Further concentration up to 50 % serum dilution, or the use of undiluted serum, resulted in a reduction of this effect.Serum aliquots were either pro-complementary or anti-complementary to cn, depending on whether they were heated at 56 or 62° C.Factors that possibly affect the complement-enhancement were investigated and evidence is presented which indicates that the electric charge on the protein particle is probably responsible for either the pro-complementary or anti-complementary serum activity; the mechanism of this, however, still remains obscure.The present work shows also that canine complement can be used instead of guinea-pig complement for testing canine sera with virus antigen by the complement-fixation reaction, an advantage of this being that the use of canine complement permits the testing of canine sera which are anti-complementary to guinea-pig complement.The data obtained are discussed in relation to canine complement and its specific activity.The authors are indebted to Professor W. I. B. Beveridge for his constructive advice, to Dr R. R. A. Coombs for his helpful comments on the complement activity, and to Dr Christine E. Rice of the Animal Diseases Research Institute, Canada, who has generously supplied the zymosan.Miss W. Barr and Miss M. Baker gave fine technical assistance throughout all the experiments. Miss M. Lambourne assisted in preparing the manuscript and graphs.

Computer-Assisted Kinetic Assay for Quantification of Total Complement Activity

1991 ◽  
Vol 8 (2) ◽  
pp. 92-103 ◽  
Author(s):  
M. Abbal ◽  
J. Tkaczuk ◽  
C. Praud ◽  
F. Msayeh ◽  
E. Ohayon
Keyword(s):  
Computer Assisted ◽  
Kinetic Assay ◽  
Complement Activity ◽  
Total Complement

SKY59, A Novel Recycling Antibody for Complement-mediated Diseases

2020 ◽  
Vol 27 (25) ◽  
pp. 4157-4164 ◽  
Author(s):  
Taku Fukuzawa ◽  
Junichi Nezu
Keyword(s):  
Inhibitory Effect ◽  
Biologic Agent ◽  
Microbial Infection ◽  
Duration Of Action ◽  
Complement Activity ◽  
Body Of Knowledge ◽  
Therapeutic Benefits ◽  
Long Duration ◽  
Recycling Technology ◽  
Current Therapies

Background: The complement system usually helps protect against microbial infection, but it could also be involved in the onset of various diseases. Inhibition of complement component 5 (C5) with eculizumab has resulted in a significant reduction of hemolysis, reduction of thromboembolic events, and increased survival in patients with Paroxysmal Nocturnal Hemoglobinuria (PNH). However, eculizumab requires frequent intravenous infusions due to the abundance of C5 in plasma and some patients may still experience breakthrough hemolysis. This review introduces the recent body of knowledge on recycling technology and discusses the likely therapeutic benefits of SKY59, a novel recycling antibody, for PNH and complement-mediated disorders. Methods: By using recycling technology, we created a novel anti-C5 antibody, SKY59, capable of binding to C5 pH-dependently. Results: In cynomolgus monkeys, SKY59 robustly inhibited C5 and complement activity for significantly longer than a conventional antibody. SKY59 also showed an inhibitory effect on C5 variant p.Arg885His, whereas eculizumab does not suppress complement activity in patients with this type of mutation. Conclusion: SKY59 is a promising anti-C5 biologic agent that has significant advantages over current therapies such as long duration of action and efficacy against C5 variants.

Immunoassay or LC-MS/MS for the measurement of salivary cortisol in children?

2016 ◽  
Vol 54 (5) ◽  
Author(s):  
Yoon Ju Bae ◽  
Alexander Gaudl ◽  
Sonia Jaeger ◽  
Stephanie Stadelmann ◽  
Andreas Hiemisch ◽  
...  
Keyword(s):  
Salivary Cortisol ◽  
Social Stress ◽  
Statistical Power ◽  
Stress Test ◽  
Externalizing Disorders ◽  
Cross Reactivity ◽  
Trier Social Stress Test ◽  
Healthy Children ◽  
Kinetic Assay ◽  
The Difference

AbstractBackground:Dysregulation of the adrenal cortex has been assessed with measurement of salivary cortisol. So far salivary cortisol is routinely measured with immunoassay (IA). However, liquid chromatography-tandem mass spectrometry (MS) is known to offer better specificity. We compared the concentrations of salivary cortisol measured by MS and IA at basal and stress induced conditions and evaluated reasons for the difference in method-dependent cortisol results.Methods:Saliva samples (n=2703) were collected from 169 children (age range: 8–14 years; 81 healthy children; 55 with internalizing and 33 with externalizing disorders) under circadian conditions and during the Trier Social Stress Test for Children (TSST-C). Biochemical analyses were performed with MS for cortisol and cortisone, IA (IBL, RE62011) for cortisol, and enzyme kinetic assay for α-amylase.Results:MS and IA showed mostly comparable results for circadian activity and TSST-C response with similar statistical power. However, IA measured cortisol concentrations about 2.39-fold higher than MS. We found that this difference in measured values between MS and IA was mainly due to different standardization of IA compared to MS. In addition, at cortisol IA concentration below 5 nmol/L, cross-reactivity with cortisone was found to contribute to the lower concordance between MS and IA.Conclusions:Immunoassay and LC-MS/MS were largely comparable in the interpretation of salivary cortisol dynamics in stress research. But the IA method revealed a restricted accuracy in the measuring range below 5 nmol/L.

scholarly journals Kinetics of tau aggregation reveals patient specific tau characteristics among Alzheimer's cases

2021 ◽  
Author(s):  
Tarun V Kamath ◽  
Naomi Klickstein ◽  
Caitlin Commins ◽  
Analiese R Fernandes ◽  
Derek H Oakley ◽  
...  
Keyword(s):  
Growth Phase ◽  
Tau Proteins ◽  
Patient Specific ◽  
Lag Phase ◽  
Plateau Phase ◽  
Kinetic Assay ◽  
Cellular Processes ◽  
Morphological Differences ◽  
Tau Aggregation ◽  
Kinetics Of

Abstract The accumulation of tau aggregates throughout the human brain is the hallmark of a number of neurodegenerative conditions classified as tauopathies. Increasing evidence shows that tau aggregation occurs in a “prion-like” manner, in which a small amount of misfolded tau protein can induce other, naïve tau proteins to aggregate. Tau aggregates have been found to differ structurally among different tauopathies. Recently, however, we have suggested that tau oligomeric species may differ biochemically among individual patients with sporadic Alzheimer disease, and have also showed that the bioactivity of the tau species, measured using a cell-based bioassay, also varied among individuals. Here, we adopted a live-cell imaging approach to the standard cell-based bioassay to explore further whether the kinetics of aggregation also differentiated these patients. We found that aggregation can be observed to follow a consistent pattern in all cases, with a lag phase, a growth phase, and a plateau phase, which each provide quantitative parameters by which we characterize aggregation kinetics. The length of the lag phase and magnitude of the plateau phase are both dependent upon the concentration of seeding-competent tau, the relative enrichment of which differs among patients. The slope of the growth phase correlates with morphological differences in the tau aggregates, which may be reflective of underlying structural differences. This kinetic assay confirms and refines the concept of heterogeneity in the characteristics of tau proteopathic seeds among individuals with Alzheimer’s disease and is a method by which future studies may characterize longitudinal changes in tau aggregation and the cellular processes which may influence these changes.

scholarly journals A 44-kb deleted-type copy number variation is associated with decreasing complement component activity and calf mortality in Japanese Black cattle

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Shinji Sasaki ◽  
Youko Miki ◽  
Takayuki Ibi ◽  
Hiroyuki Wakaguri ◽  
Yuichi Yoshida ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Copy Number Variation ◽  
Copy Number ◽  
Risk Allele ◽  
Wild Type ◽  
Japanese Black Cattle ◽  
Complement Activity ◽  
Categorical Trait ◽  
Number Variation ◽  
Calf Mortality

Abstract Background Calf mortality generally occurs in calves prior to weaning, which is a serious problem in cattle breeding. Several causative variants of monogenic Mendelian disorders in calf mortality have been identified, whereas genetic factors affecting the susceptibility of calves to death are not well known. To identify variants associated with calf mortality in Japanese Black cattle, we evaluated calf mortality as a categorical trait with a threshold model and performed a genome-wide copy number variation (CNV) association study on calf mortality. Results We identified a 44-kb deleted-type CNV ranging from 103,317,687 to 103,361,802 bp on chromosome 5, which was associated with the mortality of 1–180-day-old calves. The CNV harbored C1RL, a pseudogene, and an IncRNA localized in the C1R and C1S gene cluster, which is a component of the classical complement activation pathway for immune complexes for infectious pathogens. The average complement activity in CNVR_221 homozygotes at postnatal day 7 was significantly lower than that of wild-type animals and heterozygotes. The frequency of the risk allele in dead calves suffering from diarrhea and pneumonia and in healthy cows was 0.35 and 0.28, respectively (odds ratio = 2.2, P = 0.016), suggesting that CNVR_221 was associated with the mortality of Japanese Black calves suffering from an infectious disease. Conclusions This study identified a deleted-type CNV associated with the mortality of 1–180-day-old calves. The complement activity in CNVR_221 homozygotes was significantly lower than that in heterozygotes and wild type animals. The frequency of the risk allele was higher in dead calves suffering from an infectious disease than in healthy cows. These results suggest that the existence of CNVR_221 in calves could be attributed to a reduction in complement activity, which in turn leads to susceptibility to infections. Thus, the risk allele could serve as a useful marker to reduce the mortality of infected Japanese Black calves.

scholarly journals Moraxella lacunata infection accompanied by acute glomerulonephritis

Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 962-967
Author(s):  
Nami Sawada ◽  
Tamaki Morohashi ◽  
Tomokazu Mutoh ◽  
Tsukasa Kuwana ◽  
Junko Yamaguchi ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Case Reports ◽  
Laboratory Data ◽  
Inflammatory Cells ◽  
Final Diagnosis ◽  
Renal Tissue ◽  
Acute Glomerulonephritis ◽  
Pathological Findings ◽  
Complement Activity ◽  
Moraxella Lacunata

AbstractMoraxella lacunata (M. lacunata) is a Gram-negative bacterium, which rarely causes serious infection. This is a rare case report of acute glomerulonephritis diagnosed by pathological findings in a child accompanied by M. lacunata infection. The patient showed hematuria, proteinuria and hyperkalemia requiring emergency hemodialysis. After hospitalization, M. lacunata bacteremia became apparent. Pathological findings showed an increase in glomerulus inflammatory cells and glomerular C3 deposition was observed in the renal tissue biopsy. Final diagnosis was endocapillary proliferative glomerulonephritis. Clinical reports of M. lacunata infection requiring emergency hemodialysis in children are rare. Previous reports have suggested that lowered immune competency with chronic kidney disease may be a risk factor associated with serious invasive cases of M. lacunata infection. However, detailed clinical laboratory data and pathological findings have not been identified in previous case reports. Our case directly indicated complement activity and acute glomerulonephritis with M. lacunata infection. Although there are various causes for acute glomerulonephritis, infection-related glomerulonephritis (IRGN) is an important concept. M. lacunata infection might have a potential risk for IRGN with dysregulation of complement activity leading to serious and invasive clinical conditions than previously considered.

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