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

Author(s):  
D C Kilpatrick ◽  
J Weston ◽  
W J Irvine

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.

2020 ◽  
Vol 73 (7-8) ◽  
pp. 229-234
Author(s):  
Stanislava Nikolic ◽  
Romana Mijovic ◽  
Dragana Oluski ◽  
Tanja Ostojic ◽  
Ivana Bajkin

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.


2017 ◽  
Vol 43 (1) ◽  
pp. 71-75
Author(s):  
Sema Ciftci Dogansen ◽  
Gulsah Yenidunya Yalin ◽  
Sema Yarman

AbstractPurpose:Macroprolactin, the high-molecular mass prolactin isoform, is considered to be an inactive product with extrapituitary origin. Although macroprolactinemia is considered a benign condition, there is evidence of overlapping clinical features among patients with hyperprolactinemia. Data on the prevalence of macroprolactinemia in prolactinomas is also quite limited. The aim of this study was to assess the prevalence of macroprolactinemia in our patients with prolactinoma.Methods:The study included patients with macroprolactinoma (n=50) and microprolactinoma (n=16). Prolactin level was measured with an electrochemiluminescent immunoassay, and macroprolactinemia was defined as the percentage of prolactin recovery <40% after the polyethylene glycol precipitation.Results:Macroprolactinemia was not detected in our patients with prolactinoma (the percentage of PRL recovery range; 55%–96%). The mean percentage of prolactin recovery was similar in patients with macroprolactinoma and microprolactinoma (67.7%±8.0% and 70%±9.4%, respectively, p=0.96).Conclusion:Macroprolactinemia is generally associated with negative findings on pituitary imaging. Although the monomeric prolactin is dominant, rarely macroprolactin may also be present in prolactinomas. We did not detect presence of macroprolactin in any of the patients and there was no statistically significant difference between micro- and macroprolactinomas in terms of prolactin recovery.


1996 ◽  
Vol 75 (05) ◽  
pp. 772-777 ◽  
Author(s):  
Sybille Albrecht ◽  
Matthias Kotzsch ◽  
Gabriele Siegert ◽  
Thomas Luther ◽  
Heinz Großmann ◽  
...  

SummaryThe plasma tissue factor (TF) concentration was correlated to factor VII concentration (FVIIag) and factor VII activity (FVIIc) in 498 healthy volunteers ranging in age from 17 to 64 years. Immunoassays using monoclonal antibodies (mAbs) were developed for the determination of TF and FVIIag in plasma. The mAbs and the test systems were characterized. The mean value of the TF concentration was 172 ± 135 pg/ml. TF showed no age- and gender-related differences. For the total population, FVIIc, determined by a clotting test, was 110 ± 15% and the factor VIlag was 0.77 ± 0.19 μg/ml. FVII activity was significantly increased with age, whereas the concentration demonstrated no correlation to age in this population. FVII concentration is highly correlated with the activity as measured by clotting assay using rabbit thromboplastin. The ratio between FVIIc and FVIIag was not age-dependent, but demonstrated a significant difference between men and women. Between TF and FVII we could not detect a correlation.


1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.


Author(s):  
Yuko Komuro ◽  
Yuji Ohta

Conventionally, the strength of toe plantar flexion (STPF) is measured in a seated position, in which not only the target toe joints but also the knee and particularly ankle joints, are usually restrained. We have developed an approach for the measurement of STPF which does not involve restraint and considers the interactions of adjacent joints of the lower extremities. This study aimed to evaluate this new approach and comparing with the seated approach. A thin, light-weight, rigid plate was attached to the sole of the foot in order to immobilize the toe area. Participants were 13 healthy young women (mean age: 24 ± 4 years). For measurement of STPF with the new approach, participants were instructed to stand, raise the device-wearing leg slightly, plantar flex the ankle, and push the sensor sheet with the toes to exert STPF. The sensor sheet of the F-scan II system was inserted between the foot sole and the plate. For measurement with the seated approach, participants were instructed to sit and push the sensor with the toes. They were required to maintain the hip, knee, and ankle joints at 90°. The mean values of maximum STPF of the 13 participants obtained with each approach were compared. There was no significant difference in mean value of maximum STPF when the two approaches were compared (new: 59 ± 23 N, seated: 47 ± 33 N). The coefficient of variation of maximum STPF was smaller for data obtained with the new approach (new: 39%, seated: 70%). Our simple approach enables measurement of STPF without the need for the restraints that are required for the conventional seated approach. These results suggest that the new approach is a valid method for measurement of STPF.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tilahun Fufa Debela ◽  
Zerihun Asefa Hordofa ◽  
Aster Berhe Aregawi ◽  
Demisew Amenu Sori

Abstract Background The consequences of obstetric fistula on affected women are more than the medical condition. It has extensive physical, psychological, social, and economic consequences on them. Obstetric fistula affects the entire health and entire life of women. Women suffering from obstetric fistula are often abandoned by her partner, relatives, and the community. This study aimed to determine the quality of life of obstetrics fistula patients before and after surgical repair. Methods Institutional-based prospective, before and after study design was conducted in the Jimma University Medical Center from November 1, 2019–October 30, 2020. A face-to-face interview was conducted with fistula patients who visited Jimma University Medical center, fistula clinic during the study period. All fistula patients were included in the study. Accordingly, 78 women who underwent surgical repair were interviewed. The means and the standard deviation were computed using conventional statistics formulas. The unpaired t-test was used to compare two independent means, and one-way analysis of variance (ANOVA) was used to compare the quality of life before repair and after a successful repair. Linear regression analysis was done for identifying determinants of quality of life. A P value of 0.05 will be considered statistical significance. Result The overall quality of life of women was 58.17 ± 7.2 before the surgical repair and 71.20 ± 10.79 after surgical repair. The result indicates there is a significant difference in the mean value of pre and post-operative (P < 0.001). The overall satisfaction of women with their health status before the surgical repair was 22.5 ± 1.30and it has increased to 53.0 ± .90after surgical repair. The physical health dimension score was 16.51 ± 5.27 before the surgical repair while it has increased to 21.77 ± 5.38 after the surgical repair. The score of the social domain before the surgical repair was 5.19 ± 1.34 and it has increased to 7.13 ± 3.67 after the surgical repair. The score of the environmental health domain was 17.41 ± 2.89 before the surgery while it also increased to 21.65 ± 4.04 after the surgical repair. The results have shown there was a significant difference in the mean values of pre and post-operatives in both social and environmental scores (P < 0.001). The score of the psychological health domain before the surgery was 19.06 ± 1.46 and it was increased to 19.84 ± 3.21 after the surgical repair. The result showed there is a significant difference in mean value pre and post-operative (P = 0.048), though it is a slight improvement compared to other domains. Conclusion The overall quality of life of the patient with fistula was improved after successful surgical repair. Although all domains of quality of life had shown significant improvement after successful surgical repair, the psychological domain showed slight improvement.


Biology ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 358
Author(s):  
Javier Aragoneses ◽  
Ana Suárez ◽  
Nansi López-Valverde ◽  
Francisco Martínez-Martínez ◽  
Juan Manuel Aragoneses

The aim of this study was to evaluate the effect of implant surface treatment with carboxyethylphosphonic acid and fibroblast growth factor 2 on the bone–implant interface during the osseointegration period in vivo using an animal model. The present research was carried out in six minipigs, in whose left tibia implants were inserted as follows: eight implants with a standard surface treatment, for the control group, and eight implants with a surface treatment of carboxyethylphosphonic acid and immobilization of FGF-2, for the test group. At 4 weeks after the insertion of the implants, the animals were sacrificed for the histomorphometric analysis of the samples. The means of the results for the implant–bone contact variable (BIC) were 46.39 ± 17.49% for the test group and 34.00 ± 9.92% for the control group; the difference was not statistically significant. For the corrected implant–bone contact variable (BICc), the mean value of the test group was 60.48 ± 18.11%, and that for the control group, 43.08 ± 10.77%; the difference was statistically significant (p-value = 0.035). The new bone formation (BV/TV) showed average results of 27.28 ± 3.88% for the test group and 26.63 ± 7.90% for the control group, meaning that the differences were not statistically significant (p-value = 0.839). Regarding the bone density at the interthread level (BAI/TA), the mean value of the test group was 32.27 ± 6.70%, and that of the control group was 32.91 ± 7.76%, with a p-value of 0.863, while for the peri-implant density (BAP/TA), the mean value of the test group was 44.96 ± 7.55%, and that for the control group was 44.80 ± 8.68%, without a significant difference between the groups. The current research only found a significant difference for the bone–implant contact at the cortical level; therefore, it could be considered that FGF-2 acts on the mineralization of bone tissue. The application of carboxyethylphosphonic acid on the surface of implants can be considered a promising alternative as a biomimetic coating for the immobilization of FGF-2. Despite no differences in the new bone formation around the implants or in the interthread or peri-implant bone density being detected, the biofunctionalization of the implant surface with FGF-2 accelerates the mineralization of the bone–implant interface at the cortical level, thereby reducing the osseointegration period.


1967 ◽  
Vol 56 (1) ◽  
pp. 99-106 ◽  
Author(s):  
K. Leybold ◽  
J. Rieper ◽  
L. Weissbecker

ABSTRACT A simple method for the determination of cortisol-binding capacity is described. For saturation of the cortisol-binding proteins, plasma samples are incubated with an excess of cortisol. In the next step NADPH and liver microsomes of female rats are added. The microsomal Δ4-3-ketosteroid hydrogenase only reduces non protein-bound cortisol to tetrahydrocortisol-5α. Then the steroids are extracted by dichloromethane, and after some purification steps analyzed by fluorometry. Tetrahydrocortisol gives practically no fluorescence. The cortisol determined by this method corresponds to protein-bound cortisol and indicates the extent of cortisolbinding capacity. Precision and accuracy of the method were found to be good. The values of cortisol-binding capacity obtained by our method are compared with the results of other authors. The mean value of adult men was 25.5 ± 3.4 μg/100 ml, that of pregnant women, mens IX-X, 42.3 ± 4.2 μg/100 ml.


2004 ◽  
Vol 12 (4) ◽  
pp. 344-348 ◽  
Author(s):  
Eduardo Bresciani ◽  
Terezinha de Jesus Esteves Barata ◽  
Ticiane Cestari Fagundes ◽  
Akimi Adachi ◽  
Marina Martins Terrin ◽  
...  

The aim of this study was to compare, in different periods of time, the compressive and diametral tensile strength of a traditional high viscous glass ionomer cement: Fuji IX (GC Corporation), with two new Brazilian GIC's: Vitro-Molar (DFL) and Bioglass R (Biodinamica), all indicated for the Atraumatic Restorative Treatment (ART) technique. Fifteen disk specimens (6.0mm diameter x 3.0mm height) for the diametral tensile strength (DTS) test and fifteen cylindrical specimens (6.0mm diameter x 12.0mm height) for the compressive strength (CS) test were made of each GIC. Specimens were stored in deionized water at 37º C and 100% of humidity in a stove until testing. Five specimens of each GIC were submitted to CS and DTS test in each period, namely 1 hour, 24 hours and 7 days. The specimens were tested in a testing machine (Emic) at a crosshead speed of 1.0mm/min for CS and 0.5mm/min for the DTS test until failure occurred. The data were submitted to two-way ANOVA and Tukey tests (alpha=0.05). The mean CS values ranged from 42.03 to 155.47MPa and means DTS from 5.54 to 13.72 MPa, with test periods from 1h to 7 days. The CS and DTS tests showed no statistically significant difference between Fuji IX and Vitro Molar, except for CS test at 1-hour period. Bioglass R had lowest mean value for CS of the cements tested. In DTS test Bioglass R presented no statistically significant differences when compared with all others tested GICs at 1-hour period and Bioglass R presented no difference at 24-hour and 7-day periods when compared to Vitro-Molar. Further studies to investigate other physical properties such as fracture toughness and wear resistance, as well as chemical composition and biocompatibility, are now needed to better understand the properties of these new Brazilian GIC's.


2020 ◽  
Vol 10 (2) ◽  
pp. 82-86
Author(s):  
Mushtaq Hussain Lashari ◽  
Sumbel Sumera ◽  
Umer Farooq ◽  
Zia Ur Rehman ◽  
Nuzhat Sial ◽  
...  

Background: Health problem are culturally associated with smoking in developing countries. Many hazardous chemicals are taken up by direct or passive smoking causing lipid peroxidation resulting in oxidative stress. Objectives: To estimate the occurrence of smoking and its effects on the lipid profile in populations of Hasilpur, Pakistan. Methodology: The current study was conducted from April - August 2014. Out of 247 apparently healthy subjects of both genders (male=220; female=27), 134 were smokers and 113 were non-smokers. In order to analyze lipid profile, blood samples were collected in early morning hours from the selected members who were asked to fast all night. By using Chem-100 chemistry analyzer, cholesterol, triglyceride, HDL, LDL and VLDL were analyzed. Results: The overall prevalence of smokers was 54.25%. The results showed 60.9% prevalence in males and 0% in females. The mean value of serum triglyceride in control, light smokers and heavy smokers was 147.4±11.7mg/dl, 190.8±41.4 and 205.3±29.7mg/dl, respectively. The results of cholesterol in control, light smokers and heavy smokers were 147.38±7.99mg/dl, 136.8 ±12. 8mg/dl and 173.44±8.63mg/dl, respectively. There was a considerable distinction in the mean level of serum triglyceride and cholesterol between the control group, light smokers and heavy smoker groups (P<00.5). The mean value of HDL of control, light smokers and heavy smokers was 30.93±1.30mg/dl, 31.10±2.45 and 34.58±1.55mg/dl, respectively. The mean values of LDL and VLDL of control, light smokers and heavy smokers were 110.46±3.63mg/dl, 106.00±4.52mg/dl, 117.19±3.48mg/dl and 33.54±3.11mg/dl, 49±9.02mg/dl, 41.06±5.34mg/dl, respectively. There was significant difference in the mean level of HDL, LDL and VLDL between the control group, light smokers and heavy smoker groups (P<0.05). Conclusion: This study concluded that smoking is the reasons of variation in the lipid profile. Elevated period of smoking and the number of smoked cigarettes/day reason the alteration in serum lipid levels and is probably related with increased danger for coronary artery disease.


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