[en] A radioimmunoassay for oxytocin in cow plasma is described. Antisera were raised in rabbits against synthetic oxytocin coupled to bovine thyroglobulin. Iodinated oxytocin free of unlabelled oxytocin and most likely also free of diiodo-oxytocin was used as radioactive tracer. The tracer showed a high degree of purity, and was stable on storage. It could be used in the assay for 2-3 months. The assay showed very little cross-reactivity with vasopressin. Acetone was used for the extraction of oxytocin from plasma as well as from standards made of synthetic exytocin in pooled cow plasma. Inhibition curves obtained with plasma collected from cows at parturition were parallel to those obtained with the oxytocin standard preparation. The mean recovery of oxytocin added to cow plasma was 106% (SD=14). The within-assay coefficient of variation (CV) varied from 5.2 to 10.9%, and the between-assay CV was in the order of 13%. The assay sensitivity was 1 pg (0.5 μU) per tube, corresponding to 3 pg/ml plasma. Around the time of milking the plasma oxytocin profile showed a strong response to the preparation for milking, and a further effect related to the attachment of the teat cups of the milking machine. Peak concentrations were in the range of 15-50 pg/ml. During parturition there was a peak of oxytocin (65 pg/ml) coinciding with the expulsion phase. After this peak levels decreased by remained measurably elevated until the expulsion of the placenta. The plasma disappearance curve for immunoreactive oxutocin after the infusion of 100 IU oxytocin over a period of 1 h showed two components with apparent half-lives of 7-9 and 25 min, respectively. (author)

[en] High affinity antibodies against oxytocin were produced by multiple intradermal injections. The antibodies do not cross react with lysine vasopressin. Reduction of the S-S link changes the immunoreactivity. The high affinity constant of the antibodies allows direct RIA of oxytocin in diluted plasma (1:5), with a sensitivity of at least 4μU/ml. Preliminary results for oxytocin determination in human umbilical cord plasma range between 15-100μU/ml

[en] Objective: To reduce average induction delivery internal in patients with poor Bishop score without compromising fetomaternal outcome (in terms of birth weight, NICU admission, maternal complications and mode of delivery). Study Design: A descriptive study. Place and Duration of Study: Department of Obstetrics and Gynaecology, Pakistan Atomic Energy Commission (PAEC) General Hospital, Islamabad, from February to December 2009. Methodology: All patients needing 2nd dinoprostone pessary for induction of labour were included in the study. Patients with gestation below 37 weeks, those with intra-uterine growth restriction, bad obstetric history, previous uterine scar and patients in whom Bishop score improved for amniotomy after 1st dinoprostone pessary, were excluded. Data was collected on a special proforma where all variables were defined. Results:Out of 90 patients, 44 (48.8 percentage) had spontaneous vertex deliveries and 12 (13.3 percentage) had instrumental deliveries so a total vaginal deliveries occurred in 56 (62.2 percentage) patients. Thirty four patients (37.8 percentage) had emergency caesarean sections. Main indication for cesarean was failure to progress in 1st stage of labour followed by fetal distress. There were 3 failed inductions. Only 2 patients had hyperstimulation. NICU admission were 8 and all babies were discharged healthy from nursery with no case of early neonatal death. Conclusion:Concurrent oxytocin with 2nd dinoprostone in patients with poor Bishop scores (initial scores 2 and 3) resulted in more vaginal birth and comparatively shorter induction delivery time with almost negligible fetomaternal complications. (author)

[en] The radioimmunoassay is based on a reaction antigen-antibody, whose kinetics are expressible in mathematical terms. The specificity and sensibility of the method depend fundamentally on the specificity and the likeness of the antibody. For these reasons el RIA turns out to be a simple, quick and sensitive rehearsal, specific with potential applicability to a great number of substances

[en] The major objective of this study was to find out the consequence of exogenous administration of oxytocin to Sahiwal cow, local breed of Pakistan (to enhance milk let down) on mineral composition. Milk samples were collected from two groups of eight animals under controlled atmosphere and feeding input. The analysis of fodder and feed samples were also carried out to support this study. Means of macro and micro minerals of fodder and feed samples were determined. One group of Sahiwal cows was subjected to intramuscular injection of oxytocin (20 IU). The milk obtained from oxytocin injected animals possessed significantly higher sodium and chloride with increment in ash content. Lactose content decreased by 0.39% and ash content increased by 0.08% in milk treated with oxytocin injections. Oxytocin administration increased the level of Na (19.74%), Cl (9.39%) and Cu (146.89%) while K content decreased (10.06%). (author)

[en] A radioimmunoassay (RIA) for oxytocin (OT) in urine is described. ¹²⁵I-OT was prepared, and antibodies were raised in rabbits against OT coupled to bovine serumalbumine. This allowed us to set up a RIA for OT which limit of detection is 1.25 pg/tube (0.6 μU). The use of an extraction procedure using CG₅₀ Amberlite is essential. The recovery after extraction reaches 70.5 %. pH 5 is the optimum pH were urine samples must be stored. The superposition of the elution peak of endogenous OT on that of exogenous hormone is an argument in favour of the validity of such an extraction procedure. Daily urinary excretion of OT reaches 9.58 mU +- 3.48 in 18 healthy young men

[en] This book offers the proceedings of a symposium on the hormone of oxytocin. It includes 6 contributions of the measurement of oxytocin through radioimmunoassay. Methods of extraction; standard; preparation of the tracer are considered. Besides, the book deals with electrophysiological determinants of oxytocin secretion and neural pathways of oxytocin; biosynthesis; neuroendocrine control; physiological stimuli to synthesis and control; pharmacological uses. (G.J.P.)

[en] Objectives: To compare oral misoprostol versus intramuscular oxytocin in the management of third stage of labour. Methods: The quasi-experimental study was conducted at the Obstetrics and Gynaecology Unit II, Civil Hospital, Karachi, from June 20 to December 19, 2006. A total of 70 patients diagnosed in active phase of labour who fulfilled the inclusion criteria were selected by non-probability convenience sampling. These patients were divided into 2 groups of 35 patients each, for Oxytocin (Group 1) and misoprostol (Group 2). Main and secondary outcome measures were analysed. SPSS 10 was used for statistical analysis. Results: Average amount of blood loss(ml) was 267.14+-140.35 with Oxytocin versus 302.86+-160.4, with Misoprostol, this difference was statistically insignificant (p=0.236). Average drop in haemoglobin concentration (g/dl) with Oxytocin was 1.55+-0.38 vs 1.66+-0.61 with Misoprostol (p=0.684). Drop in haematocrit (%) was 4.18+-0.64 with Oxytocin vs. 4.50+-0.92 with Misoprostol (p=0.133). There was also insignificant difference in duration of third stage of labour, between oxytocin and Misoprostol groups (5.37+-2.20 vs. 5.23+-2.46, p=0.451) Shivering, in Misoprostol group occured in n=11 (31.4%) vs n=3 (8.6%) with Oxytocin (p=0.017) and pyrexia in n=6 (17.1%) with misoprostol vs n=0, with oxytocin (p=0.025) thus significantly higher in misoprostol group. Conclusion: There were no major differences in oral misoprostol and intramuscular oxytocin in the management of third stage of labour. (author)

[en] Objective: To look for failed trail of labor after one caesarean section and predicting factors associated with failed labor Study Design: Cross-sectional Study. Place and Duration of Study: Gynecology and Obstetrics department Pak Emirates Military Hospital, Rawalpindi Pakistan, from May 2021 to Oct 2021. Methodology: A prospective study was conducted on the women who were booked cases in our department for antenatal checkups and labor. Those women with history of one caesarean section were recruited for the analysis. They underwent labor in our department and those with failed labor were diagnosed and managed by consultant obstetrician. Relevant clinical factors associated with failed labor among women with one previous caesarean section included in our study. Results A total of 380 women who underwent labor in our hospital with one previous caesarean section were recruited. Mean age of the women included in the study was 34.43±7.36 years. 162(42.6%) had successful trial of labour while in 218(57.4%) women trail of labour could not succeed. Statistical analysis revealed that gestation age more than 40 weeks, poor Bishop score (<5) at admission and requirement of labour augmentation (with oxytocin) were found statistically significantly associated with failed trial of labour in our study participants (p-value<0.05). Conclusion Failed trial of labour was a common clinical condition in women with one previous caesarean section. Women with gestation age more than 40 weeks, poor bishop score at admission and requiring labour augmentation were more at risk of having failed trial in our study participants. (author)

[en] The response of plasma oxytocin and vasopressin to machine milking in cows was studied by radioimmunoassay. Depending on the method of machine milking used, plasma oxytocin increased to a greater or lesser degree after teat cup application. Plasma vasopressin was not affected by the milking procedures. (author)