A new automated turbidimetric immunoassay for quantifying alpha 1-antitrypsin in serum.

1986 ◽  
Vol 32 (6) ◽  
pp. 1020-1022 ◽  
Author(s):  
J A Viedma ◽  
A de la Iglesia ◽  
M Parera ◽  
M T López
Keyword(s):  
Polyethylene Glycol ◽  
Parametric Estimation ◽  
Tween 20 ◽  
Upper Limit ◽  
Analytical Recovery ◽  
The Mean ◽  
Alpha 1 Antitrypsin ◽  
Polyethylene Glycol 6000 ◽  
Immunoprecipitation Reaction ◽  
Turbidimetric Immunoassay

Abstract This rapid, sensitive equilibrium turbidimetric immunoassay for quantification of alpha 1-antitrypsin involves a monospecific antibody, polyethylene glycol 6000 to accelerate and enhance the immunoprecipitation reaction, and Tween 20 surfactant to decrease and stabilize the sample-blank values. Turbidity at 334 nm is measured by an automated discrete analyzer. Grossly lipemic, icteric, or hemolyzed samples can be assayed. Correlation with results by radial immunodiffusion (RID) was excellent (r = 0.97, n = 84). Analytical recovery averaged 97.7 (SD 2.9)%. Within-run CVs ranged from 1.6 to 1.9%, between-day CVs from 2.0 to 3.5%. Reference values for healthy adults (n = 147) were determined by parametric estimation (for an assumed normal distribution of untransformed data). The lower limit (g/L) with its 0.90 confidence interval is 1.23 (range 1.18-1.28), the upper limit is 2.15 (2.10-2.20), and the mean is 1.69 g/L.

Turbidimetric immunoassay of serum C-reactive protein.

1982 ◽  
Vol 28 (10) ◽  
pp. 2121-2124 ◽  
Author(s):  
S Otsuji ◽  
H Shibata ◽  
M Umeda
Keyword(s):  
Radial Immunodiffusion ◽  
Tween 20 ◽  
C Reactive Protein ◽  
Standard Curve ◽  
Reactive Protein ◽  
Analytical Recovery ◽  
Polyethylene Glycol 6000 ◽  
Sample Dilution ◽  
Immunoprecipitation Reaction ◽  
Turbidimetric Immunoassay

Abstract This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.

scholarly journals Macroprolactinaemia: Contribution to Hyperprolactinaemia in a District General Hospital and Evaluation of a Screening Test Based on Precipitation with Polyethylene Glycol

1997 ◽  
Vol 34 (3) ◽  
pp. 252-258 ◽  
Author(s):  
M N Fahie-Wilson ◽  
S G Soule
Keyword(s):  
Polyethylene Glycol ◽  
Screening Test ◽  
Reference Range ◽  
Gel Filtration ◽  
District General Hospital ◽  
Serum Prolactin ◽  
Common Phenomenon ◽  
Common Cause ◽  
Upper Limit ◽  
Polyethylene Glycol 6000

For a period of 12 months all samples submitted for serum prolactin (PRL) assay and with PRL>700mU/L were examined by gel filtration chromatography. In 17 (25%) of 69 samples we found macroprolactin. The Delfia and Immuno 1 immunoassay systems gave similar PRL results with samples containing macroprolactin whereas the ACS 180 system gave lower results. With the Delfia and Immuno 1 systems samples containing substantial quantities of macroprolactin showed low recovery of PRL after precipitation with polyethylene glycol 6000 (PEG 6000) and this technique can be used as a screening test for macroprolactinaemia. We conclude that macroprolactinaemia is a common phenomenon and, in assays which detect this species, is a common cause of hyperprolactinaemia. Macroprolactinaemia may contribute to the difficulty in establishing an upper limit of the reference range for serum PRL. In our experience, patients with macroprolactinaemia do not exhibit features of the hyperprolactinaemia syndrome and it is important to recognize macroprolactin as the cause of hyperprolactinaemia to avoid unnecessary investigation and treatment.

scholarly journals Initial evaluation of cystatin C measurement by particle-enhanced immunonephelometry on the Behring nephelometer systems (BNA, BN II)

1997 ◽  
Vol 43 (6) ◽  
pp. 1016-1022 ◽  
Author(s):  
Hazel Finney ◽  
David J Newman ◽  
Walter Gruber ◽  
Peter Merle ◽  
Christopher P Price
Keyword(s):  
Glomerular Filtration Rate ◽  
Rheumatoid Factor ◽  
Cystatin C ◽  
Filtration Rate ◽  
Mean Difference ◽  
Serum Cystatin C ◽  
Serum Cystatin ◽  
Upper Limit ◽  
Analytical Recovery ◽  
Turbidimetric Immunoassay

Abstract Serum cystatin C has been suggested as a new marker of glomerular filtration rate (GFR). We describe a fully automated and rapid particle-enhanced nephelometric immunoassay (PENIA) for measuring serum cystatin C on the Behring nephelometer systems (BNA, BN II). Each sample is analyzed in 6 min with as many as 75 samples per batch. The assay covers the range 0.23–7.25 mg/L, up to seven times the upper limit of normal. The intra- and interassay imprecision are <3.3% and <4.5%, respectively. There is absolute linearity across the assay range (r2 = 0.997), with analytical recovery by cystatin C addition between 95% and 109% (mean 102%). Hemoglobin (≤8.0 g/L), bilirubin (≤488 μL), triglycerides (≤23 mmol/L), rheumatoid factor (≤2000 kIU/L), and myeloma paraprotein (≤41 g/L) do not interfere with the assay. This assay agreed well with an in-house particle-enhanced turbidimetric immunoassay (PETIA) (mean difference = 1.73 ± 2.10) and a commercial PETIA (mean difference = 1.13 ± 0.86). This is a new assay by which cystatin C may be effectively used as a marker of GFR estimation.

Hepatitis a Virus Concentration from Experimentally Contaminated Distilled, Tap, Waste and Seawater

1989 ◽  
Vol 21 (3) ◽  
pp. 255-258 ◽  
Author(s):  
Evangélos Biziagos ◽  
Jacques Passagot ◽  
Jean-Marc Crance ◽  
Robert Deloince
Keyword(s):  
Cell Culture ◽  
Polyethylene Glycol ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Tap Water ◽  
Virus Concentration ◽  
Beef Extract ◽  
Polyethylene Glycol 6000

The concentration of cell-culture-adapted hepatitis A virus (HAV) from experimentally contaminated distilled, drinking, waste and seawater was performed by using a filter adsorption-elu-tion method in the following conditions: HAV seeded in water was adsorbed at pH 4.0 to two nitrocellulose membranes (1.2 and 0.45 µm porosity for distilled and tap water or 8.0 and 3.0 µm porosity for waste and seawater), then eluted by 3% beef-extract at pH 8.5 and further concentrated by polyethylene glycol 6000 precipitation. Thus, HAV in 5 to 50 liters of seeded waters was concentrated approximately 1,700 to 17,000 fold with greater than 70% recovery of the initial virus added to the samples.

Prolactin Screening in a Cohort of Schizophrenia Patients in Birmingham

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
I. Waheed ◽  
A. Khan
Keyword(s):  
Health Centre ◽  
Drug Dosage ◽  
Oral Risperidone ◽  
Clinical Symptomatology ◽  
Upper Limit ◽  
Routine Monitoring ◽  
Current Medication ◽  
The Mean ◽  
Unselected Group

Aim:To establish the numerical prevalence and severity of raised prolactin levels in patients apparently asymptomatic.Method:All outpatients with schizophrenia receiving antipsychotics at Small Heath Health Centre had routine annual prolactin measurements. the sampling was done 0900-1300 either in clinic or at patient's homes. the Upper Limit of Normal (ULN) for prolactin was set by the hospital pathology service at 324 mIU/L (males) and 496 mIU/L (females). Sampling was done 0900-1200 either in clinic or at patient's homes. We recorded the patient's name, age, unit number, ethnicity, details of current medication, recent changes to medication and symptoms of hyperprolactinaemia.Results:Prolactin levels were obtained for 43 patients (M: 24 F:19). All of these patients had no clinical symptomatology that had led to prolactin measurements previously. Abnormal values were found in 47 per cent of females and 58 per cent of males, or 56 per cent (n=24) of the whole cohort. the mean prolactin was 789 mIU/L with a mean of 497 mIU/L in males and 1100 mIU/L in females. All patients on oral risperidone had hyperprolactinaemia.Conclusion:Routine prolactin screening showed abnormal values in 56 per cent of patients and significantly abnormal levels (>1000 mIU/L) that should lead to consideration of drug/dosage alterations in 26% of patients. the prevalence of hyperprolactinaemia in an unselected group of outpatients with schizophrenia suggests that consideration may be given to routine monitoring.

scholarly journals FORMULATION AND EVALUATION OF ATORVASTATIN CALCIUM NANOCRYSTALS CONTAINING P-GLYCOPROTEIN INHIBITORS FOR ENHANCING ORAL DELIVERY

2021 ◽  
pp. 19-23
Author(s):  
SARAH LABIB ◽  
MOHAMED NASR ◽  
MOHAMED NASR
Keyword(s):  
Polyethylene Glycol ◽  
Oral Drug Delivery ◽  
Tween 80 ◽  
Degree Of Crystallinity ◽  
Oral Drug ◽  
Tween 20 ◽  
Atorvastatin Calcium ◽  
Peg 400 ◽  
P Glycoprotein ◽  
Saturated Solubility

Objective: The main objective of this study was to develop atorvastatin calcium (ATR) as an oral drug delivery system for a P-glycoprotein (P-gp) substrate drug using different pharmaceutical excipients that inhibit P-glycoprotein and evaluate the influence of nanocrystals on the dissolution characteristics and bioavailability compared to the plain drug. Methods: A nanosuspension was prepared by Solvent-antisolvent precipitation method using a solvent containing stabilizer that act as a p-gp inhibitor dissolved in distilled water as polyethylene glycol 300, polyethylene glycol 400 (PEG 300, PEG 400), tween 20 and tween 80 while the solvent selected for atorvastatin calcium was methanol. The concentrations were as follows: PEG 300 and 400 = 0.25% w/v, tween 20 and 80 = 0.75% v/v. Nanocrystals were extracted from the suspension and characterized. Results: Particle size of the drug was 1307±127.79 nm while the formulas prepared ranged from 223±17.67 to 887±58.12 nm. Pure ATR had a saturated solubility of 0.059±0.005 mg/ml and the prepared nanocrystals ranged from 0.32±0.021 to 0.88±0.019 mg/ml. The Percentage of drug released of plain atorvastatin calcium reached 41.49% while the formula ranged from 44.32 to 61.5%. Both XRD and SEM discussed the degree of crystallinity as follows: F1<F2<F4<F3<ATR. Conclusion: 0.3% of PEG 300 and PEG 400 were not enough to formulate proper nanocrystals while 0.75% tween 20 and tween 80 achieved acceptable formulas. F4 which is prepared with tween 80 exhibited the highest enhancement in saturated solubility, dissolution rate and subsequently expected to have improved oral bioavailability.

scholarly journals Effects of Matric and Osmotic Priming Treatments on Broccoli Seed Germination

1996 ◽  
Vol 121 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Lewis W. Jett ◽  
Gregory E. Welbaum ◽  
Ronald D. Morse
Keyword(s):  
Polyethylene Glycol ◽  
Seed Germination ◽  
Root Growth ◽  
Growth Rates ◽  
Germination Rate ◽  
Membrane Integrity ◽  
Seed Vigor ◽  
Radicle Emergence ◽  
The Mean ◽  
Peg 8000

Priming, a controlled-hydration treatment followed by redrying, improves the germination and emergence of seeds from many species. We compared osmotic and matric priming to determine which was the most effective treatment for improving broccoli seed germination and to gain a greater understanding of how seed vigor is enhanced by priming. Broccoli (Brassica oleracea L. var. italica) seeds were osmotically primed in polyethylene glycol (PEG 8000) at -1.1 MPa or matrically primed in a ratio of 1.0 g seed:0.8 g synthetic calcium silicate (Micro-Cel E):1.8 ml water at -1.2 MPa. In the laboratory, germination rates and root lengths were recorded from 5 to 42C and 10 to 35C, respectively. Broccoli seeds germinated poorly at >35C. Root growth after germination was more sensitive to temperatures >30C and <15C than radicle emergence. Matric and osmotic priming increased germination rate in the laboratory, greenhouse, and field. However, matric priming had a greater effect on germination and root growth rates from 15 to 30C. Neither priming treatment affected minimum or maximum germination or root growth temperatures. Both priming treatments decreased the mean thermal time for germination by >35%. The greater germination performance of matrically primed seeds was most likely the result of increased oxygen availability during priming, increased seed Ca content, or improved membrane integrity.

scholarly journals Is there a trend in cirrus cloud cover due to aircraft traffic?

2005 ◽  
Vol 5 (8) ◽  
pp. 2155-2162 ◽  
Author(s):  
F. Stordal ◽  
G. Myhre ◽  
E. J. G. Stordal ◽  
W. B. Rossow ◽  
D. S. Lee ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Cloud Cover ◽  
Reasonable Agreement ◽  
Global Scale ◽  
Cirrus Cloud ◽  
Positive Trend ◽  
Spatially Correlated ◽  
Upper Limit ◽  
Main Emphasis ◽  
The Mean

Abstract. Trends in cirrus cloud cover have been estimated based on 16 years of data from ISCCP (International Satellite Cloud Climatology Project). The results have been spatially correlated with aircraft density data to determine the changes in cirrus cloud cover due to aircraft traffic. The correlations are only moderate, as many other factors have also contributed to changes in cirrus. Still we regard the results to be indicative of an impact of aircraft on cirrus amount. The main emphasis of our study is on the area covered by the METEOSAT satellite to avoid trends in the ISCCP data resulting from changing satellite viewing geometry. In Europe, which is within the METEOSAT region, we find indications of a trend of about 1-2% cloud cover per decade due to aircraft, in reasonable agreement with previous studies. The positive trend in cirrus in areas of high aircraft traffic contrasts with a general negative trend in cirrus. Extrapolation in time to cover the entire period of aircraft operations and in space to cover the global scale yields a mean estimate of 0.03 Wm-2 (lower limit 0.01, upper limit 0.08 Wm-2) for the radiative forcing due to aircraft induced cirrus. The mean is close to the value given by IPCC (1999) as an upper limit.

scholarly journals X-ray Constraints on AGN Clustering

1989 ◽  
Vol 134 ◽  
pp. 492-493
Author(s):  
G. De Zotti ◽  
M. Persic ◽  
A. Franceschini ◽  
L. Danese ◽  
G.G.C. Palumbo ◽  
...  
Keyword(s):  
Space Distribution ◽  
Background Intensity ◽  
Additional Contribution ◽  
List Type ◽  
X Ray ◽  
Upper Limit ◽  
Angular Scale ◽  
Sky Survey ◽  
The Mean ◽  
X Ray Background

Studies of the HEAO–1 A2 all–sky survey data have established that the level of anisotropy of the extragalactic X–ray background (XRB) is relatively low: –The cell–to–cell XRB intensity variations can be entirely accounted for by Poisson fluctuations in the space distribution of known classes of sources; the 90% confidence upper limit to any additional contribution on a scale of 26 square degrees is 2.3% (Shafer and Fabian 1983).–No significant correlations of XRB intensity fluctuations appear to be present; the formal 90% confidence upper limit on the amplitude of autocorrelations, relative to the mean background intensity, for an angular scale of 3° is Γ(3°) ≤ 1.9 × 10−2 (Persic et al. 1988).

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