A NOVEL MICROTITER PLATE ASSAY FOR FUNCTIONAL PLASMINOGEN-ACTIVA-TOR INHIBITOR (PAI) LEVELS IN WHOLE PLASMA

1987 ◽  
Author(s):  
R C Carroll ◽  
R M HAnsard ◽  
M H GoldMan
Keyword(s):  
Age Groups ◽  
Microtiter Plate ◽  
Functional Assay ◽  
Age Group ◽  
Plasma Samples ◽  
Major Drawback ◽  
Microtiter Plate Assay ◽  
Microtiter Plates ◽  
Linear Slope ◽  
Plasmin Inhibitor

Currently, the most widely used functional assay for PAI levels in plasma is that developed by Chmielewska et al (Thromb. Res. 31:427-436, 1983). A major drawback of this assay is the considerable manipulation of plasma samples required by the necessity of acidification and reneutralization in order to determine remaining activator levels based on plasminogen to plasmin conversion. We have devised an assay based on microtiter plates coated with 20 U/ml urokinase. In this assay, aliquots of citrate- or EDTA-anticoagulated plasma are incubated in the coated wells for 30 min at room temperature to allow PAI in the plasma to complex with the solid state urokinase. The plasma is then removed, the wells extensively washed with Tris-saline buffer plus 1 mg/ml bovine serum albumin, and the remaining urokinase activity determined by adding plasminogen and S-2251 chroma-genic substrate for plasmin. Inhibitor levels can be conveniently expressed as percent inhibition relative to the urokinase activity in wells not exposed to plasma. Absolute units of inhibitor have also been derived by titration of plasma samples with known units of urokinase (calibrated by S-2444 chromagenic substrate for plasminogen activators). Between the range of 90% to 10% inhibition, a linear slope of 0.69±0.6 units ml-1/10% inhibition is obtained.In agreement with previous reports, we find a wide variation in control subjects and some tendency towards higher PAI levels in older age groups. Age group 20-39, n=29, 36.6 ± 14.9%. Age group 40 and over, n=16, 48.9 ±12.9%.Reproducible values (SEM ± 4.6%,n=5)are obtained for control* individuals sampled and assayed at various times over a period of several months. We have also assayed plasma samples from patients undergoing a variety of surgical procedures, and have followed rapid post-surgical increases in PAI levels with a gradual return to pre-operative levels. Evidence is presented that the post-surgical increase is predominantly from the platelet releasable pool.

scholarly journals Semiautomated microtiter plate assay for monitoring peptidylprolyl cis/trans isomerase activity in normal and pathological human sera

1998 ◽  
Vol 44 (3) ◽  
pp. 502-508 ◽  
Author(s):  
Gerhard Küllertz ◽  
Sabine Lüthe ◽  
Gunter Fischer
Keyword(s):  
Biological Fluids ◽  
Microtiter Plate ◽  
Serum Samples ◽  
Ppiase Activity ◽  
Microtiter Plate Assay ◽  
Isomerase Activity ◽  
Microtiter Plates ◽  
Activity Factor ◽  
Healthy Donors ◽  
Human Sera

Abstract An UV/VIS spectrophotometric assay technique was developed that was able to routinely monitor peptidylprolyl cis/trans isomerase (PPIase) activity of biological fluids in 96-well microtiter plates. The assay, based on monitoring the cis-to-trans isomerization of succinyl-Phe-cisPro-Phe-4-nitroanilide as substrate in a chymotrypsin-coupled reaction, yields a throughput of 96 samples per 30 min. The assay’s capacity was exemplified by dealing with the PPIase activity in several normal and pathological human sera. Reference values of 151 healthy subjects (83 females, 69 males, 17 to 60 years old) were found to possess significant sex-specific differences. PPIase activity factor K of the sera was significantly greater in males (5th, 50th, 95th percentiles: 17, 36, 55 K) than females (14, 30, 48 K). PPIase activities of sera from healthy donors (n = 151) were significantly higher (Mann–Whitney rank-sum test P <0.0001) than those of patients (n = 47). PPIase activity in serum samples stored at 4 °C was stable for at least 20 h.

Hydrodynamic Evaluation of Microtiter Plate Assay Using Computational Fluid Dynamics for Biofilm Formation

2019 ◽  
Author(s):  
R. Zahra ◽  
A. A. Khan ◽  
M. Sajid
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Bacterial Cells ◽  
Microtiter Plate Assay ◽  
Plate Assay ◽  
Microtiter Plates ◽  
Biofilm Production ◽  
Static Conditions

Abstract Biofilms are complex surface associated communities where bacterial cells are enclosed by self-produced extra cellular polymeric substances (EPS), mainly consisting of exopolysaccharides, proteins and extracellular DNA. Treatment of biofilm associated persistent infections is an emerging issue for clinicians as bacterial cells adhere with human epithelial cells or indwelling medical devices such as implants and catheters, used in urinary tract and respiratory infections. Several methods are in practice to assess the biofilm formation of bacterial strains. Most of these are phenotypic methods which include Congo red assay (CRA), Air liquid interface (ALI), tissue culture plate method and Microtiter plate assay (MTPA). MTPA is considered as a standard screening method for comparing adherence pattern and is the most widely used quantitative method for detection of biofilm formation. Generally, the assay is performed under standard static conditions and little is known about the hydrodynamics in the microtiter plates. A few studies have applied computational fluid dynamics (CFD) simulations to describe flow pattern in microtiter plates during biofilm production and optimized the suitable conditions to detect the biofilm formation which have proven to be efficient. In this work the dependencies of biofilm formation on the hydrodynamics in microtiter plate assays were evaluated using OpenFOAM® an open-source toolbox for numerical simulation. It was found that higher flow rates increase the nutrient availability, promote cell growth, and attachment pattern with increased production of exopolymer, while the increase in flow velocity increases the shear rate causing erosion and disassembly of biofilm production because of detachment from the surface.

scholarly journals Detection of Microbial Growth on Polycyclic Aromatic Hydrocarbons in Microtiter Plates by Using the Respiration Indicator WST-1

2002 ◽  
Vol 68 (6) ◽  
pp. 2683-2689 ◽  
Author(s):  
Anders R. Johnsen ◽  
Karen Bendixen ◽  
Ulrich Karlson
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Carbon Sources ◽  
Microtiter Plate ◽  
Water Soluble ◽  
Most Probable Number ◽  
Microtiter Plate Assay ◽  
Probable Number ◽  
Microtiter Plates ◽  
Polycyclic Aromatic

ABSTRACT We have developed a microtiter plate method for screening a large number of bacterial isolates for the ability to grow on different crystalline polycyclic aromatic hydrocarbons (PAHs). Growth on PAHs cannot easily be determined with standard growth assays because of the very low aqueous solubility and bioavailability of the PAHs. Our microtiter plate assay utilizes a new water-soluble respiration indicator, WST-1 {4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate}, in combination with easily degradable carbon sources. PAH-mineralizing strains were grown on PAHs in microtiter plates for 7 to 10 days. The tetrazolium dye WST-1 was added after incubation. Dehydrogenases in growing cells reduced WST-1 to a water-soluble colored formazan, and the intensity of the color was a measure of the respiration rate. Addition of easily degradable carbon to the wells along with WST-1 resulted in a 3- to 40-fold increase in the absorbance of positive wells within 90 min, which made it possible to detect growth on fluorene, phenanthrene, anthracene, fluoranthene, and pyrene. Addition of the electron transport blocker sodium azide unexpectedly decreased formazan formation. The method was adapted for most-probable-number enumeration of PAH degraders in soil.

The Effect of Collagen Mediated Platelet Release on Plasma Prekallikrein Activation

1984 ◽  
Vol 51 (01) ◽  
pp. 037-041 ◽  
Author(s):  
K M Weerasinghe ◽  
M F Scully ◽  
V V Kakkar
Keyword(s):  
Platelet Aggregation ◽  
Healthy Volunteers ◽  
Platelet Rich Plasma ◽  
Age Groups ◽  
Inhibitory Effect ◽  
Age Group ◽  
Platelet Factor ◽  
Activated Platelets ◽  
Platelet Release ◽  
Collagen Treatment

SummaryCollagen mediated platelet aggregation caused -5.6 ± 6.7% inhibition and +39.1 ± 15.2% potentiation of prekallikrein activation in plasma from normal healthy volunteers between 20–40 and 50–65 years of age, respectively (n = 15, p <0.01). The amouns of platelet factor-four (PF4) released in the two groups were not significantly different. Collagen treatment in the presence of indomethacin caused +11.5 ± 3.6% and +59.6 ± 19.5% potentiation in the 20–40 and 50–65 age groups respectively (p <0.02). Adrenaline mediated platelet aggregation caused -55.2 ± 7.1% and -35.2 ± 8.3% inhibition in the 20–40 and 50–65 age groups, respectively. Collagen treatment of platelet-deficient-plasma and platelet-rich-plasma in EDTA also caused potentiation of prekallikrein activation.The results indicate that the observed degree of prekallikrein activation after platelet aggregation is a net result of the inhibitory effect of PF4 and the potentiatory effect of activated platelets. The potentiatory effect was greater after collagen treatment as compared to adrenaline treatment, and in the 50–65 age group as compared to the 20–40 age group.

Health and Nutritional Status of Orphan Children’s Living in Orphanages with Special Reference to District Anantnag of Jammu and Kashmir

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Mashkoor Ahmad Lone ◽  
Dr. P. Ganesan
Keyword(s):  
Age Groups ◽  
Indian Academy ◽  
Dental Enamel ◽  
Nutritional Intake ◽  
Age Group ◽  
Asian Countries ◽  
Jammu And Kashmir ◽  
Material Resources ◽  
Height For Age ◽  
Weight For Age

The practice of placing deprived children having least or no emotional and material resources, in orphanages has since long been prevailing in socio -economically poor Asian countries. A sample of 30 children residing in orphanage in district Anantnag in the age group of 13-18 years was selected for the present study. Most of the children were found socially and psychologically disturbed. As per Indian Academy Paediatrics (IAP) classification with respect to weight for age the condition was not bad that as approximately 67% percent of the children were found to be normal. In the same way height for age as per Waterloo’s classification shown that more than half of the children were normal. On clinical examination approximately 47% of children were normal, while as rest were suffering from dispigmentation of hair, moon face, xerosis of skin cheilosis, magenta tongue, spongy bleeding gums, oedema, conjuctival xerosis, and mottled dental enamel. The findings indicated that nutritional intake was deficient for all nutrients when compared to, Recommended Daily Allowances Chart (RDA) for all age groups which may be linked to poor planning of menus in orphanages.

COVID-19 Epigenetics and Implications for Public Health

Coronaviruses ◽  
2020 ◽  
Vol 01 ◽  
Author(s):  
Verda Tunalıgil ◽  
Gülsen Meral ◽  
Ahmet Katı ◽  
Dhrubajyoti Chattopadhyay ◽  
Amit Kumar Mandal
Keyword(s):  
Chronic Conditions ◽  
Empirical Investigation ◽  
Age Groups ◽  
Infectious Agent ◽  
Well Being ◽  
Epigenetic Mechanisms ◽  
Age Group ◽  
Epigenetic Changes ◽  
Patient Groups ◽  
Epigenetic Processes

Abstract:: Epigenetic changes in COVID-19 host, a pandemic-causing infectious agent that globally incapacitated communities in varying complexities and capacities are discussed, proposing an analogy that epigenetic processes contribute to disease severity and elevate the risk for death from infection. Percentages of hospitalization, with and without intensive care, in the presence of diseases with increased ACE2 expression, were compared, based on the best available data. Further analysis compared two different age groups, 19-64 and ≥65 years of age. The COVID-19 disease is observed to be the most severe in the 65-and-higher-age group with preexisting chronic conditions. This observational study is a non-experimental empirical investigation of the outcomes of COVID-19 in different patient groups. Results are promising for conducting clinical trials with intervention groups. To ultimately succeed in disease prevention, researchers and clinicians must integrate epigenetic mechanisms to generate valid prescriptions for global well-being.

scholarly journals Tower Running—Participation, Performance Trends, and Sex Difference

2020 ◽  
Vol 17 (6) ◽  
pp. 1902 ◽  
Author(s):  
Daniel Stark ◽  
Stefania Di Gangi ◽  
Caio Victor Sousa ◽  
Pantelis Nikolaidis ◽  
Beat Knechtle
Keyword(s):  
Sex Differences ◽  
Statistical Model ◽  
Sex Difference ◽  
Random Effects ◽  
Age Groups ◽  
Repeated Measurements ◽  
Stair Climbing ◽  
Age Group ◽  
Performance Trends ◽  
The Difference

Though there are exhaustive data about participation, performance trends, and sex differences in performance in different running disciplines and races, no study has analyzed these trends in stair climbing and tower running. The aim of the present study was therefore to investigate these trends in tower running. The data, consisting of 28,203 observations from 24,007 climbers between 2014 and 2019, were analyzed. The effects of sex and age, together with the tower characteristics (i.e., stairs and floors), were examined through a multivariable statistical model with random effects on intercept, at climber’s level, accounting for repeated measurements. Men were faster than women in each age group (p < 0.001 for ages ≤69 years, p = 0.003 for ages > 69 years), and the difference in performance stayed around 0.20 km/h, with a minimum of 0.17 at the oldest age. However, women were able to outperform men in specific situations: (i) in smaller buildings (<600 stairs), for ages between 30 and 59 years and >69 years; (ii) in higher buildings (>2200 stairs), for age groups <20 years and 60–69 years; and (iii) in buildings with 1600–2200 stairs, for ages >69 years. In summary, men were faster than women in this specific running discipline; however, women were able to outperform men in very specific situations (i.e., specific age groups and specific numbers of stairs).

scholarly journals Ten-year trends of hypertension treatment and control rate in Korea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kwang-il Kim ◽  
Eunjeong Ji ◽  
Jung-yeon Choi ◽  
Sun-wook Kim ◽  
Soyeon Ahn ◽  
...  
Keyword(s):  
Age Groups ◽  
Favorable Effect ◽  
Age Group ◽  
Hypertension Treatment ◽  
Treatment Rate ◽  
Cross Sectional ◽  
The Past ◽  
Nationally Representative ◽  
Multistage Sampling ◽  
And Control

AbstractWe analyzed the Korean National Health and Nutrition Examination Survey (KNHANES) database to determine the trends of hypertension treatment and control rate in Korea over the past 10 years. In addition, we tried to investigate the effect of chronic medical conditions on hypertension management. We investigated the hypertension prevalence, awareness, treatment, and control rate from 2008 to 2017. KNHANES, which uses a stratified multistage sampling design, is a cross-sectional, nationally representative survey conducted by the Korean government. A total of 59,282 adults (≥ 20 years) were included, which was representative of the total population of around 40 million Koreans per year. The mean age was 50.7 ± 16.4 years and 42.6% were male. The prevalence of hypertension, hypercholesterolemia, diabetes mellitus, and obesity significantly increased over the 10 years. During this period, the hypertension treatment and control rate significantly improved. Hypertension treatment rate was significantly lower in the younger age group compared to the older age group, but the control rate among the treated patients was not significantly different between age groups. The treatment and control rates of hypertension were higher in patients with multimorbidity, which implies that it has a favorable effect on the treatment and control of hypertension. Hypertension treatment and control rate have improved over the past 10 years. The higher treatment and control rate in patients with multimorbidity suggest that the more aggressive surveillance might be associated with the improvement of hypertension treatment and control rate in Korea.

scholarly journals A Study of Varicella Seroprevalence in a Pediatric and Adolescent Population in Florence (Italy). Natural Infection and Vaccination-Acquired Immunization

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 152
Author(s):  
Beatrice Zanella ◽  
Angela Bechini ◽  
Benedetta Bonito ◽  
Marco Del Riccio ◽  
Alessandra Ninci ◽  
...  
Keyword(s):  
Natural Infection ◽  
Age Groups ◽  
Varicella Vaccination ◽  
Age Group ◽  
Disease Notification ◽  
Test Elisa ◽  
Vaccine Schedule ◽  
Almost All ◽  
Vaccination Campaigns ◽  
Dose Vaccine

Background: Varicella is a well-known infectious disease that can have severe complications, also in young children. The Universal Varicella Vaccination (UVV) program was introduced in Tuscany (Italy) in 2003, with a two-dose vaccine schedule given to children between their 13th and 15th month, and at 5–6 years old, as a monovalent for varicella (V) or tetravalent (measles, mumps, rubella and varicella (MMRV)) formulation. Although varicella notifications have dramatically fallen in the last two decades, varicella disease underreporting remains a challenge. Methods: A qualitative immunoenzymatic test (ELISA) was used to measure the presence of anti-varicella antibodies in 165 sera of subjects aged 1–18 years residing in the province of Florence (Italy). Information regarding the anamnestic and vaccination status (including disease notification) was also collected. Results: Our study showed an overall varicella seropositivity of 75.8% (reaching the maximum at 96.3% in the 15–18 years age group). We found that varicella disease notification had been recorded for only 7/165 subjects; however, since 42/165 recalled having had the disease, we can hypothesize that some of them must have been underreported. Furthermore, our study showed that the presence of antibodies after the varicella vaccination remained over time, lasting up to 12 years. Conclusions: Although varicella seroprevalence is <95% in almost all our age groups (except for the 15–18 years age group), our data are encouraging and reflect the success of the introduction of the UVV program and the vaccination campaigns promoted in the Tuscany region.

scholarly journals Screening for optimal protease producing Bacillus licheniformis strains with polymer-based controlled-release fed-batch microtiter plates

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tobias Habicher ◽  
Tobias Klein ◽  
Jacqueline Becker ◽  
Andreas Daub ◽  
Jochen Büchs
Keyword(s):  
Controlled Release ◽  
Bacillus Licheniformis ◽  
Protease Activity ◽  
Microtiter Plate ◽  
Fed Batch ◽  
Batch Mode ◽  
Screening Process ◽  
Microtiter Plates ◽  
Batch Fermenter ◽  
Production Conditions

Abstract Background Substrate-limited fed-batch conditions have the favorable effect of preventing overflow metabolism, catabolite repression, oxygen limitation or inhibition caused by elevated substrate or osmotic concentrations. Due to these favorable effects, fed-batch mode is predominantly used in industrial production processes. In contrast, screening processes are usually performed in microtiter plates operated in batch mode. This leads to a different physiological state of the production organism in early screening and can misguide the selection of potential production strains. To close the gap between screening and production conditions, new techniques to enable fed-batch mode in microtiter plates have been described. One of these systems is the ready-to-use and disposable polymer-based controlled-release fed-batch microtiter plate (fed-batch MTP). In this work, the fed-batch MTP was applied to establish a glucose-limited fed-batch screening procedure for industrially relevant protease producing Bacillus licheniformis strains. Results To achieve equal initial growth conditions for different clones with the fed-batch MTP, a two-step batch preculture procedure was developed. Based on this preculture procedure, the standard deviation of the protease activity of glucose-limited fed-batch main culture cultivations in the fed-batch MTP was ± 10%. The determination of the number of replicates revealed that a minimum of 6 parallel cultivations were necessary to identify clones with a statistically significant increased or decreased protease activity. The developed glucose-limited fed-batch screening procedure was applied to 13 industrially-relevant clones from two B. licheniformis strain lineages. It was found that 12 out of 13 clones (92%) were classified similarly as in a lab-scale fed-batch fermenter process operated under glucose-limited conditions. When the microtiter plate screening process was performed in batch mode, only 5 out of 13 clones (38%) were classified similarly as in the lab-scale fed-batch fermenter process. Conclusion The glucose-limited fed-batch screening process outperformed the usual batch screening process in terms of the predictability of the clone performance under glucose-limited fed-batch fermenter conditions. These results highlight that the implementation of glucose-limited fed-batch conditions already in microtiter plate scale is crucial to increase the precision of identifying improved protease producing B. licheniformis strains. Hence, the fed-batch MTP represents an efficient high-throughput screening tool that aims at closing the gap between screening and production conditions.

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