scholarly journals Assessment of macroprolactinemia by the polyethylene glycol precipitation method

2020 ◽  
Vol 73 (7-8) ◽  
pp. 229-234
Author(s):  
Stanislava Nikolic ◽  
Romana Mijovic ◽  
Dragana Oluski ◽  
Tanja Ostojic ◽  
Ivana Bajkin
Keyword(s):  
Polyethylene Glycol ◽  
The Other ◽  
Precipitation Method ◽  
Serum Prolactin ◽  
Serum Samples ◽  
Simple Method ◽  
Significant Difference ◽  
Low Incidence ◽  
Polyethylene Glycol Precipitation ◽  
Phosphate Buffered Saline

Introduction. Macroprolactinemia is one of the common causes of hyperprolactinemia, especially in cases where standard routine commercial immunometric assays are used for prolactin level measurement. Two forms of prolactin, inactive dimeric prolactin (50 - 60 kDa) and a low-activity tetramer (molecular weight above 150 kDa), contribute to this condition. The relatively low incidence of symptoms in macroprolactinemia patients has necessitated a relatively simple method to detect large, biologically inactive prolactin molecules, such as polyethylene glycol precipitation method. The aim of this study was to compare the precipitation method using polyethylene glycol dissolved in phosphate buffered saline in relation to polyethylene glycol dissolved in water. Material and Methods. This study included 82 patients who visited the Center of Laboratory Medicine, Clinical center of Vojvodina, to determine serum prolactin levels. The obtained serum samples were divided into two aliquots. The first aliquot was frozen and stored at - 20?C and the other was immediately analyzed. Aqueous solution was added to one aliquot and polyethylene glycol Merck 6000 to the other. All serum and supernatant samples were analyzed using the automated Abbott Architect i2000sr immunoassay. Recovery values were calculated as the ratio of double values of free prolactin and total prolactin concentration, expressed as a percentage. Results. The prolactin concentrations and calculated recovery values were lowest in fresh supernatant prolactin treated with phosphate buffered saline. Statistical analysis showed no significant difference in the calculated recovery values obtained by precipitation of fresh and frozen sera using polyethylene glycol dissolved in phosphate buffered saline (p = 0.893). Conclusion. Precipitation using polyethylene glycol dissolved in phosphate buffered saline is a more reliable method for laboratory detection of macroprolactinemia compared to polyethylene glycol dissolved in water.

Some Studies on the Polyethylene Glycol Turbidity Method for Detecting Immune Complexes in Serum

1981 ◽  
Vol 18 (6) ◽  
pp. 373-377 ◽  
Author(s):  
D C Kilpatrick ◽  
J Weston ◽  
W J Irvine
Keyword(s):  
Polyethylene Glycol ◽  
Immune Complexes ◽  
Solid Phase ◽  
Mean Value ◽  
Simple Method ◽  
Significant Difference ◽  
The Mean ◽  
Turbidity Method ◽  
Polyethylene Glycol Precipitation ◽  
Routine Assay

A rapid and simple method for detecting circulating immune complexes based on turbidity measurements following polyethylene glycol precipitation was studied with regard to its suitability as a routine assay in clinical laboratories. This method was found to have an acceptable degree of precision provided the temperature was carefully controlled. The mean value obtained with a group of 70 blood donors was 0·09 (SD 0·05) and the 90th percentile value was 0·16. There was no significant difference between values obtained from groups divided on the basis of age or sex. Of 70 diabetic sera assayed by the polyethylene glycol turbidity method, 20% gave positive values although only 10% were strongly positive. The corresponding figures for the solid phase Clq binding method were 15·7% and 14·3%, respectively. Correlation between the two methods was poor. It was concluded that although both methods have a similar likelihood of detecting immune complexes in randomly selected diabetics, it is probable that different immune complexes were being detected.

scholarly journals Prevalence of hepatitis G virus (HGV) among hepatitis-B patients and others suspected for PT-hepatitis in Baghdad

2013 ◽  
Vol 7 (1) ◽  
pp. 35-40
Author(s):  
Ghassaq Tariq Sadiq
Keyword(s):  
Hepatitis B ◽  
The Other ◽  
Control Group ◽  
Minor Role ◽  
Shadow Zone ◽  
Serum Samples ◽  
Hepatitis G Virus ◽  
Significant Difference ◽  
Group 2 ◽  
A Minor

The aim of this research is to evaluate the prevalence of HGV among three different categories, group1, composed of hepatitis –B patients (HB- patients), group 2, included people having hepatitis-like symptoms with sera negative for HBV and HCV markers, referred to as suspected for hepatitis (SUS-patients) while the third group is the control group. Serum samples were assayed for anti-HGV antibodies using ELISA technique-indirect method. Results revealed that HGV coinfection detected in only few number of HB-P 9.8%, 23.5% of HB-P having anti-HGV antibodies with titer lower than the cut-off value (COV) which are said to be in the shadow zone and the other 66.6% of the group are reported as negative cases, reporting a highly significant difference P˂0.001. Among the second group (SUS- patients), HGV was detected in only 4.8%, 58.5% detected as shadow cases while the other 36.5% were found to be negative for HGV.When both HB-P and SUS-P are gathered in one group a low percentage 7.6% of HGV infection was recorded, 39.1% of HB-/SUS-patients were in the shadow zone while the majority of this group 53.2% were detected as negative cases. In conclusion HGV play only a minor role as a confection agent with HBV and as a responsible agent among non-A-E hepatitis cases. Remarkable high percentages of shadow cases are reported in the three groups especially among non-A-E hepatitis patients.

scholarly journals An Investigation of the Effectiveness of Bupivacaine Applied to the Abdominal Wall and Fallopian Tubes in Reducing Pain after Laparoscopic Tubal Ligation

1986 ◽  
Vol 14 (2) ◽  
pp. 148-151 ◽  
Author(s):  
P. T. Cook ◽  
T. F. Lambert
Keyword(s):  
General Anaesthesia ◽  
Analogue Scale ◽  
Tubal Ligation ◽  
The Other ◽  
Fallopian Tubes ◽  
Moderate Pain ◽  
Double Blind ◽  
Pain Scores ◽  
Significant Difference ◽  
Low Incidence

Sixty women having laparoscopic sterilisation performed under general anaesthesia were randomly allocated to one of two groups. Intraoperatively, one group had bupivacaine applied topically to the fallopian tubes and injected into the skin wounds, while the other group received no local anaesthetic. A double-blind investigation utilising a visual analogue scale failed to demonstrate a statistically significant difference in postoperative pain between the two groups. In both groups there was a significant reduction in mean pain scores between ½ and 7 hours, but there was no further reduction between 7 hours and 17 hours. At 7 hours, only 10% of patients scored their pain as 3 or greater (out of a possible 10). It is concluded that the use of bupivacaine as described is not a useful adjuvant to general anaesthesia and that the low incidence of even moderate pain at 7 hours confirms the view that these patients are suitable for management in the day-stay unit.

Determination of Ultrafilterable Prolactin: Elimination of Macroprolactin Interference With a Monomeric Prolactin-Selective Sample Pretreatment

2006 ◽  
Vol 130 (12) ◽  
pp. 1807-1812
Author(s):  
Adam M. Quinn ◽  
Tara C. Rubinas ◽  
C. Jean Garbincius ◽  
Earle W. Holmes
Keyword(s):  
Clinical Laboratory ◽  
Elevated Serum ◽  
Gel Filtration ◽  
Sample Pretreatment ◽  
Serum Prolactin ◽  
Albumin Concentration ◽  
Serum Samples ◽  
Simple Method ◽  
Healthy Female ◽  
Undiluted Serum

Abstract Context.—Macroprolactin (macroPRL), present in as many as 25% of serum specimens with elevated serum prolactin concentrations, can cause apparent hyperprolactinemia in the absence of clinical features and lead to unnecessary clinical, laboratory, and neuroradiological workups. Objective.—To develop an ultrafiltration method that eliminates macroPRL interference from PRL immunoassays. Design.—The method involves centrifugation of undiluted serum in a Centricon-100 filter device followed by a PRL assay of the serum ultrafiltrate. Results.—Ultrafiltrates prepared by this technique are devoid of gamma globulins and contain (mean ± SE) 19% ± 7% of the albumin concentration of the original serum. These ultrafiltrates contain 85% ± 7% of the total PRL immunoreactivity of serum spiked with 23 kd recombinant human prolactin (rHuPRL) and less than 2% of the 50 kd big PRL (bPRL) of whole serum. The fractional recovery of ultrafilterable PRL (uPRL) from serum samples of 54 female patients was 0.78 (confidence interval 0.73–0.83) of the total. The run-to-run coefficient of variation of the uPRL assay was 4.3%. The uPRL concentration (mean ± SD) in a group of healthy female controls was 8.0 ± 3.1 ng/mL. Conclusions.—Ultrafiltration is a rapid and simple method for eliminating analytical interference by macroPRL. Ultrafiltrates can be analyzed by most, if not all, currently available PRL immunoassays and represent a practical and precise alternative to gel filtration chromatography for the estimation of the monomeric prolactin concentration of serum.

scholarly journals Macroenzyme detection by polyethylene glycol precipitation

2003 ◽  
Vol 40 (5) ◽  
pp. 514-520 ◽  
Author(s):  
D Fraser Davidson ◽  
Dawn JM Watson
Keyword(s):  
Enzyme Activity ◽  
Polyethylene Glycol ◽  
Typical Case ◽  
Precipitation Method ◽  
Reference Ranges ◽  
Case Histories ◽  
Additional Test ◽  
Plasma Enzyme ◽  
Diagnostic Confusion ◽  
Polyethylene Glycol Precipitation

Background: The presence of macroenzymes can cause significant diagnostic confusion and their detection can involve relatively cumbersome analytical procedures. Methods: Using a simplified polyethylene glycol precipitation technique and isoenzyme electrophoresis, this report describes the construction of reference ranges of precipitable activity for each of seven commonly measured enzymes in plasma. Results: The proposed reference ranges are reported. Since introducing the protocol, 12 cases of macroenzymaemia have been encountered. Three typical case histories are described in some detail. Conclusions: The polyethylene glycol precipitation method has thus far proved to be a simple and effective additional test for the detection of macroenzymes when the plasma enzyme activity is elevated.

scholarly journals The prevalence of ovine herpesvirus-2 in 4 sheep breeds from different regions in South Africa

2010 ◽  
Vol 81 (2) ◽  
Author(s):  
C.W. Bremer
Keyword(s):  
South Africa ◽  
Nested Pcr ◽  
Lower Incidence ◽  
The Other ◽  
Malignant Catarrhal Fever ◽  
Single Tube ◽  
Sheep Breeds ◽  
Significant Difference ◽  
Herpesvirus 1 ◽  
Low Incidence

About 90% of bovine malignant catarrhal fever (BMCF) PCR-positive cases in South Africa are caused by alcelaphine herpesvirus-1 (AlHV-1) and the other 10 % by ovine herpesvirus-2 (OvHV-2). The prevalence of OvHV-2 in different sheep breeds in South Africa was determined in order to investigate whether the lower incidence of BMCF caused by OvHV-2 in comparison with AlHV-1 can be ascribed to a low incidence of the virus in sheep. A single-tube hemi-nested PCR was developed, evaluated and applied to detect OvHV-2 DNA. The prevalence of the virus in 4 sheep breeds from various regions in South Africa was shown to be 77 %. No statistically significant difference was found amongst the sheep breeds tested.

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