The Effects of Anti-insulin Antibodies and Cross-reactivity with Human Recombinant Insulin Analogues in the E170 Insulin Immunometric Assay / 대한진단검사의학회지

BACKGROUND: Insulin assays are affected by varying degrees of interference from anti-insulin antibodies (IAs) and by cross-reactivity with recombinant insulin analogues. We evaluated the usefulness of the E170 insulin assay by assessing IA effects and cross-reactivity with 2 analogues. METHODS: Sera were obtained from 59 type 2 diabetes patients receiving continuous subcutaneous insulin infusion and 18 healthy controls. Insulin levels were determined using an E170 analyzer. To investigate the effects of IAs, we performed IA radioimmunoassays, and analyzed the differences between directly measured insulin (direct insulin) and polyethylene glycol (PEG)-treated insulins (free, IA-unbound; total, IA-bound and unbound insulin). We performed in-vitro cross-reactivity tests with insulin aspart and insulin glulisine. RESULTS: In IA-positive patients, E170 free insulin levels measured using the E170 analyzer were significantly lower than the direct insulin levels. The mean value of the direct/free insulin ratio and IA-bound insulin, which were calculated as the difference between total and free insulin, increased significantly as endogenous IA levels increased. The E170 insulin assay showed low cross-reactivities with both analogues (< 0.7%). CONCLUSIONS: IAs interfered with E170 insulin assay, and the extent of interference correlated with the IA levels, which may be attributable to the increase in IA-bound insulin, and not to an error in the assay. The E170 insulin assay may measure only endogenous insulin since cross-reactivity is low. Our results suggest that the measurement of free insulin after PEG pre-treatment could be useful for beta cell function assessment in diabetic patients undergoing insulin therapy.

Urine neopterin: a new parameter for monitoring disease activity in patients with systemic lupus erythematosus

Urine neopterin/creatinine [N/C] ratio was determined in early morning samples of 16 children with active systemic lupus erythematosus [SLE] and 10 children with inactive SLE disease, using radioimmunoassay [RIA] for measuring urine neopterin Concentration. Compared with apparently healthy 20 control children the mean urine N/C ratio was significantly increased in patients with active [P <0.001] and inactive [P <0.01] SLE. The mean urine N/C ratio was also significantly higher in children with active than in. those with inactive SLE [P <0.001]. The urine N/C ratio did not distinguish between patients with renal activity and those with other types of clinical activity and it was not influenced by different drug regimens. The correlation between urine N/C ratio and erythrocyte sedimentation rate [ESR] was a positive linear one while there was no significant correlation between urine N/C ratio and serum C4. When testing urine N/C ratio at a cut-off value of >/= 300 micro mol neopterin/mol creatinine and ESR at a cut-off value of >/= 50 mm/hr and serum C4 at a cut-off value of

The importance of employing homologous serum free of thyronines in radioimmunoassays to assess circulating thyroid hormones in rainbow trout

A pesar de ser abundante, la información relacionada con los valores de tironinas circulantes en la trucha arcoiris, es confusa. El presente estudio demuestra la importancia de mantener especies sero-homólgoas durante la medición de tironinas con RIE para eviatar falsos resultados. La utilización de suero homólogo (trucha) libre de tironinas en la curva estándar permite la estandarización de radioinmunoensayos exactos y específcos para cuantificar los niveles circulates de T3 y T4 en 10 microl de suero de trucha arcoiris. El límite de detección fue de 50 pg para ambas tironinas. Los coeficientes de variación inter e intra ensayo fueron menores al 10 por ciento. Los valores promedio para T3 y T4 + - DEM en la población de truchas estudiadas (n=34) fueron 23.6 + - 1.2 y 12.0 + - 2.3 ng/ml respectivamente. Se obsevó una correlación positiva y significativa (p < 0.005) entre el peso corporal y T3 confirmando la participación activa de esta tironina en el proceso de crecimiento.

Level of prostaglandin [F2 Alpha] during vaginal cerclage

This study included 30 cases in two groups. The first group is 20 cases undergoing vaginal cerclage [17 McDonald 3 modified Shirodkar]. Three samples were taken from every case, one before induction of anaesthesia and second after induction of anaesthesia and the third after completing the procedure, the levels of PGF 2 in plasma were measured, the mean level before induction of anesthesia was [434.75 +/- 618.56] and increased after induction of anesthesia [443.15 +/- 559.68] and increased again after completing the procedure [444.6 +/- 600.59]. The second group is 10 pregnant cases as control, two blood samples were taken from every case five minute before and after P.V. The mean level of PGF2 before P.V, was [885.4 +/- 793.84] and after P.V. was [680.80 +/- 803.24]. As the statical difference is not significant so we recommend that no need to routine administration of prostaglandin synthetase inhibitors during vaginal cerclage

Clinical and endocrine features of ultrasound diagnosed polycystic ovary patients the correlation between ovarian volume and androgen activity

125 cases with PCO on ultrasound, under went detailed clinical and endocrine evaluation the age matched control group comprised volunteers with normal ovaris on ultrasound and regular ovulatory cycles. Both group were subjected to ultrasound examination and radioimmunassay for E2, FSH, LH testosterone, and androstenedion and DHEAS. 32.8 percent of PCO patient were found to have ovarian volume within normal range while 67.2 percent had enlargement overasis, and there was a significant positive correlation between ovaries volume and serum LH [P=0.56, P<0.05] testosterone R=0.46 P<0.05] and androstenedion R=0.42, P<0.05] and DHEAs levels R=0.48, P<0.05

Significance of human chorionic gondotrophin value in tubal pregnancy

The study has been conducted on 20 conclusive cases, surgically proved to be tubal pregnancy, to detect whether serum B-HCG can predict site of rupture of tubal pregnancy, their ages ranged between 21 and 35 years and their parity ranged from nullipara to five parities. The gestational age at operation averaged 59.9 +/- 12.08 days. Out of 20 cases, 13 cases were ruptured [65%] while only 7 cases [35%] were unruptured. The mean serum B-HCG for ruptured tubal pregnancy was much higher than that of unruptured tubal cases. The mean levels were 528.8 +/- 303.8 and 222.4 +/- 51.5 mul/ml, respectively. Those planning for conservative or chemotherapeutic management of tubal pregnancy, an arbitrary serum HCG value of 280 mul/ml can be used as cut off limit for integrity of tubal pregnancy

Importance of free thyroxine in comparison with total thyroxine in thyroid exploration

The authors report a study about the more discriminative value of FTA versus TT4 in thyroid investigation. 196 patients have been tested: - 33 normal subjects. 48 patients suffering of hyper [n =24] or hypothyroidism [n = 24]. 115 patients who are clinically euthyroid but with disturbed TBG [75 impregnated with oestrogen, 17 undergoing a corticotherapy and 23 suffering of nephritic syndrome]. Their TT4, ET4 and TSH have been assedded by radioimmunoassay. In normal and dysthyroid patients the values of their three hormones agree with each other. The clinical euthyroid state of the third group is confirmed by their normal FT4and TSH values. Their apparent TT4 values are influenced by the disturbed value of their TBG [p < 0.0001].The assessment of FT4 associated to TSH seems to be an accurate test to investigate the thyroid function and the binding proteins

Correlation between endometrial biopsy and serum progesterone levels in prediction of corpus luteum function

Endometrial biopsy specimens were obtained from 40 normally menstruating women with unproven fertility 2 to 3 days before the anticipated onset of menses. A simultaneous blood sample was obtained for measurement of serum progesterone levels using radioimmunoassay technique. From these 40 biopsies, 27 were in-phase [IP] and 13 were out-of-phase [OOP]. Although a deliberate attempt was made to perform the biopsy 2 to 3 days before the onset of menses, there was some variation in the actual time of the biopsy as a result of the natural variation in the menstrual function. The mean serum P level obtained from women with OOP biopsies 3-4 days before the onset of menses was significantly lower than those obtained 1-2 days before the onset of menses. So, menstruation occurred in women with OOP biopsies at a time when serum progesterone level was apparently rising