Maternal awareness and neonatal outcome after ketamine induction of anaesthesia for Caesarean section

Ketamine was used as the sole anaesthetic during the induction-to-delivery interval in 20 full-term patients undergoing elective Caesarean section. The intravenous administration of ketamine 1.5 mg.kg-1 was followed by succinylcholine 1.5 mg.kg-1 and tracheal intubation. The mother's lungs were then ventilated using 100 per cent oxygen until the baby was delivered. Intraoperative maternal awareness was assessed by the isolated forearm technique. The Apgar scores of the newborn at one and five minutes, as well as their umbilical vein blood gases were also evaluated and correlated with the induction-to-delivery (I-D) and the uterine incision-to-delivery (U-D) intervals. In 13 patients (Group A) the I-D interval was less than 10 min and U-D interval less than 90 sec, while in seven (Group B) the I-D interval was greater than or equal to 10 min and the U-D interval greater than or equal to 90 sec. The isolated arm test was negative in all patients having an I-D interval less than 10 min, and was positive in three patients when the I-D interval exceeded ten minutes. The newborns of group A showed higher Apgar scores at one minute, as well as higher umbilical vein PO2 than was achieved in Group B. It was concluded that the technique used was not associated with maternal awareness or neonatal depression, provided that the I-D interval was less than 10 min and the U-D interval was less than 90 sec.

Awareness following different techniques of general anaesthesia for caesarean section

Using the isolated arm technique, the frequency of awareness was evaluated in 50 full-term patients undergoing elective Caesarean section under general anaesthesia. In 20 patients, anaesthesia was induced with thiopentone 4 mg kg-1, and in the other 30 patients, induction was with ketamine 1.5 mg kg-1. Following suxamethonium 1.5 mg kg-1 and tracheal intubation, anaesthesia was supplemented during the induction-delivery period in the thiopentone group with 50% nitrous oxide and 0.5% halothane in oxygen in 10 patients, and with 1% halothane in 100% oxygen in the other 10 patients. In the ketamine group, the patients underwent ventilation with 50% nitrous oxide and 0.5% halothane in oxygen in 10 patients, with 1% halothane in 100% in 10 patients, and with 100% oxygen only in the last 10 patients. Awareness was significantly greater after induction with thiopentone (14/20) than after ketamine (4/30). There were no significant differences in Apgar scores or umbilical vein blood-gas values in the newborns.

Pulmonary hypoplasia and osteogenesis imperfecta type II with defective synthesis of alpha I(1) procollagen

Perinatal lethal osteogenesis imperfecta (OI type II), a heritable disorder of connective tissue occurs approximately once in 60,000 live births. Phenotypic characteristics include defective cranial ossification and severe skeletal deformity due to intrauterine rib and long bone fractures. Lethal OI may be associated with intracranial hemorrhage or severe respiratory insufficiency. Pulmonary hypoplasia has been previously observed in OI type II, but has not been defined clinically. The infant described herein was born with OI type II and pulmonary hypoplasia. Pathological examination of airway branching patterns indicated that lung development had progressed to only the 10 week stage with immature acinar development. Investigation type I collagen synthesis by cultured dermal fibroblasts revealed the presence of electrophoretically abnormal alpha 1(I) polypeptides. These findings suggest that biochemically regulated processes, as well as mechanical factors, may impeded pulmonary development in similar cases of OI type II.

A method for determining simultaneously the dose and the elapsed time since irradiation using TLDs

Information about the time that has elapsed since an external radiation exposure is useful in order to determine the time of occurrence of an abnormal exposure in personal and accidental dosimetry is presented. This information can be obtained from certain irradiated thermoluminescent dosimeters. A computational method based on decay rates of thermoluminescence glow peaks has been used to estimate a range of suitable values of trap lifetimes of low temperature glow peaks. This provides a basis for the selection of an appropriate thermoluminescent material to assess not only the absorbed dose from a radiation exposure, but also the elapsed time. Experimental studies have been used to obtain additional information on decay rates as a function of energy, temperature and absorbed dose.

Obstetric diagnosis and perinatal mortality

A multidisciplinary team composed of obstetricians, pediatricians, and pathologists examined the causes of 453 consecutive perinatal deaths, which occurred between 1978 to 1982. A clear distinction between obstetric diagnosis and infant cause of death was made, and a prinicpal obstetric and infant diagnosis was assigned to each death. Perinatal death rates by obstetric category were calculated. The rates varied from 6.1 per 1000 births in uncomplicated cases to 217.4 per 1000 births in isolated intrauterine growth retardation. The causes of perinatal death within obstetric categories were tabulated. Nonviability or the complications of prematurity (65%) were the leading causes of death when there was third-trimester bleeding, premature labor, or premature rupture of membranes. Anoxia (59%) was the most frequent cause of death when there was hypertension/pre-eclampsia or other uteroplacental insufficiency states. Death from congenital abnormality accounted for 17.7% of all perinatal deaths. A focus on the causes of perinatal death with obstetric diagnostic categories helps weigh the risk of prematurity versus the risk of anoxia in the management of high-risk gravidas.

Receptor-assay for endogenous inhibitors of Na-K ATPase

It is now accepted that there is an endogenous digitalis-like substance (EDLS), previously called natriuretic factor, present in different mammalian species which participates to the regulation of the sodium balance and at least in some situations, to the genesis of hypertension. The physiological and pathophysiological role of this substance is well recognized. However, its chemical nature remains elusive. Our purpose was to define a receptor assay for this EDLS in order to be able to measure its concentration in urine and blood. To do so, we first prepared a pool of lyophylised urine from salt loaded men. The active material was isolated by Sephadex G25 chromatography. Using the same active fraction, we investigated its biological effects. Series of experiments have demonstrated the various properties of the EDLS: inducing natriuresis when injected into a rat, diminishing short circuit current in toad's bladder and colonic mucosa of rat in in vitro preparations, inhibiting Na-K ATPase activity in isolated toad's bladder cells, binding to ouabain receptors and cross-reacting with different antibodies directed against digoxin. Among these properties, the binding to ouabain receptors offers the unique opportunity to progress in our knowledges of the substance, making possible the calculation of its constant of affinity and the estimation of the molality of the active material contained in a gram of crude extract. Knowing the constant of affinity of the EDLS for its receptor would provide the best identification of the substance as long as we do not know its exact chemical nature.(ABSTRACT TRUNCATED AT 250 WORDS)

Are opioid peptides co-localized with vasopressin or oxytocin in the neural lobe of the rat?

The content of vasopressin, oxytocin, neurophysin, leucine-enkephalin, methionine-enkephalin, dynorphin-(1-13), and alpha-neoendorphin in the rat neurohypophysis was measured after different periods of dehydration and after depolarisation of isolated neural lobes and of neurosecretory nerve endings. The rates at which the amount of neurohypophysial hormone and opioid peptides decreased, and the changes in the ratios between the amount of vasopressin or oxytocin and opioid peptide in the neurohypophysis after dehydration and in the incubation medium after depolarization in vitro cast some doubt on, and can be explained by mechanisms other than co-localisation of the different peptides.

The value of endocervical curettage as part of the standard colposcopic evaluation

Whether to perform endocervical curettage (ECC) as part of a routine colposcopic examination in patients with an abnormal Papanicolaou smear remains controversial. Some studies consider ECC an essential part of a colposcopic examination regardless of the level of the squamocolumnar junction (SCJ); others consider it superfluous in cases where the SCJ can be visualized. Between January 1980 and December 1982, 278 new patients with abnormal Papanicolaou smears underwent colposcopy. Directed biopsies established the degree of cervical intraepithelial neoplasia (CIN) and ruled out invasive disease. ECC was done on every patient. A total of 51 patients (18%) had a positive ECC. Seven patients could not be evaluated because their records were incomplete. Of the 44 evaluable patients, 32 (73%) had satisfactory colposcopy. In the remaining 12 (27%) the upper limit of the transformation zone could not be seen clearly; in that group the degrees of CIN on colposcopic biopsy and ECC were in agreement in two cases; ECC revealed the degree to be less severe in four cases and more severe in six (50%). In the group with satisfactory examinations, 15 had the same degree of CIN on colposcopic biopsy and ECC; ten had less severe and seven (22%), more severe degrees of CIN on ECC. Of greatest clinical importance was that, overall, 11.5% had a positive ECC despite a satisfactory colposcopic examination. This study indicated that ECC provides unique and important information, justifying its inclusion as part of the standard evaluation of every patient undergoing colposcopy for abnormal cervical cytology.

Fetal neuroblastoma and catecholamine-induced maternal hypertension

A case of congenital neuroblastoma is presented. The interesting features are maternal symptomatology consistent with fetal production of catecholamines and the dilemmas of differential diagnosis. Observations are made on the frequency and diagnosis of fetal neoplasia. Antepartum detection of catecholamine metabolites may be the basis for the diagnosis of fetal neuroblastoma.

Simultaneous radioimmunoassay for plasma arginine-vasopressin and oxytocin using DEAE Sephadex A 25 extraction

A sensitive and specific radioimmunoassay method for simultaneous measurement of plasma arginine vasopressin (AVP) and oxytocin (OT) has been developed utilizing an extraction technique on DEAE Sephadex A25. This procedure resulted in mean recoveries of 70.7% (AVP) and 65.4% (OT) in the peptide range of 5 to 100 pg/4 ml. The sensitivity of the assay is 0.5 pg/tube for AVP and 2 pg/tube for OT. The lower limit of detection for plasma extracts was 1.2 pg AVP/ml and 5 pg OT/ml plasma. Employing this method in normal human non smokers and ad libitum fluid the basal levels (mean +/- SE) of plasma AVP are 3.5 +/- 0.2 pg/ml in males and 4.6 +/- 0.4 pg/ml in females and the basal concentrations of plasma OT are 5.1 +/- 0.3 pg/ml in males and 5.4 +/- 0.3 pg/ml in females. Dehydration and water loading produced significant changes in plasma AVP and OT concentrations and a significant correlation exists between plasma AVP and plasma (r = 0.96, p less than 0.001) and urinary (r = 0.84, p less than 0.01) osmolality, but not between plasma OT concentrations and plasma (r = 0.11, NS) and urinary (r = 0.27, NS) osmolality. These results suggest that a wide range of physiological and pathophysiological changes in plasma AVP and OT can be simultaneously measured by the extraction procedure and the radioimmunoassay described.

Phagocytosis and onset of human labor

An in vitro experimental model has been developed which allows the study of amnion lysosomal enzyme release under controlled conditions. Briefly, a layer of human amnion membrane mounted on a specially designed reaction vessel serves as the reaction surface. We have noted that the addition of particulate material to these membranes incubating in pseudoamniotic fluid results in an increased release of the lysosomal marker enzyme N-acetylglucosaminidase when compared to the release in the absence of particles. This release is completely inhibited by iodoacetate and slightly by azide. A similar increased release is also noted with the use of term amniotic fluid as incubation medium when compared to centrifuged (30,000 g/20 min) amniotic fluid. Lecithin and lysolecithin were effective in releasing increasing amounts of enzyme. This increased release was noted only from membranes of placentas collected from subjects who had undergone cesarean section prior to labor. Membranes collected from vaginal deliveries after labor showed a baseline increased release but no further stimulation upon the addition of any of the substances. These results suggest that the release of lysosomal enzymes from amnion membranes is brought about by substance(s) present in amniotic fluid. Very probably, these are surfactants. The interaction of these substances with amnion cells would eventually result in an exponential burst of prostaglandin synthesis, which would result in labor.

Presence of vasopressin, oxytocin and neurophysin in the retina of mammals, effect of light and darkness, comparison with the neuropeptide content of the neurohypophysis and the pineal gland

Arginine vasopressin (AVP) and oxytocin (OT) as well as their CNS carrier neurophysins (Np) have been found in the pineal gland. In view of the analogy between the pineal gland and the retina, the contents of these neuropeptides in rat, human and bovine retinae were determined. AVP, OT and Np were detected by specific radioimmunoassay (RIA) and their presence confirmed by RIA measurements (1) in rat and human retinae on HPLC fractions and (2) by the detection of the C-terminal portion of the precursor to AVP and its associated Np = propressophysin (CPP). The AVP and OT content in the retina of the rat was modified by light: AVP and OT content was smaller at 2 a.m. than at 2 p.m., but was increased by a 7 day constant exposure to darkness. In contrast, pituitary content was decreased after 7 days of constant darkness. If one optic nerve was cut we observed a decrease in retinal AVP content compared to the contralateral side and a decrease in pituitary AVP content. Our data clearly demonstrated the presence of AVP, OT and Np in the retina and their variation induced by light. It is probable that these peptides are of central origin.

Changes in total serum immunoreactive neurophysins and corticosterone levels after restraint stress in rats

This study indicates that total immunoreactive circulating neurophysins (IRN) increased in male rats submitted to acute restraint stress. Total immunoreactive serum corticosterone levels also were elevated, confirming the stressful character of the restraint situation. It is speculatively suggested that IRN elevations due to stress are the reflection of a corticotropin releasing factor (CRF)-IRN product.

Suppressed prolactin but normal neurophysin levels in cigarette smoking breast-feeding women

The hormonal responses to breast-feeding were studied during the first 3 post-partum weeks in ten women smoking more than fifteen cigarettes/day and in a control group. Basal PRL levels were significantly lower in smokers compared with non-smokers, but suckling induced acute increments in serum PRL and oxytocin-linked neurophysin, which were not influenced by smoking. The lactational pattern was normal, but smokers weaned their babies significantly earlier compared with non-smokers. Heavy cigarette smoking women have lower basal PRL levels and this may shorten the period of lactation.

Presence of neurophysins I and II in the human pineal gland: comparison with the content of neurohypophyseal hormones

We have previously measured the individual content of immunoreactive vasopressin (AVP), oxytocin (OT) and vasotocin (AVT) in 155 human pineal glands, and report here identification and measurement of the neurophysin (Np) content of the same glands, using specific homologous human neurophysin I (HNp I) and neurophysin II (HNp II) radioimmunoassays. Median values for HNp I were for men 47 ng/gland (range, 5 to 1360) and for women 24 ng/gland (range, 5 to 1000); median values for HNp II were respectively 7 ng/gland (range, 2 to 191) and 15 ng/gland (range, 2 to 356) with no significant difference between men and women for HNp I and HNp II but a significant difference (p less than 0.001) between HNp I and HNp II for both sexes. Gel filtration showed that pineal neurophysins were eluted at the same volume as both standard Np and Np from human posthypophyses used as controls. HNp I correlated both with AVP (rs = 0.54 for men and 0.55 for women) and OT (rs = 0.86 for men and 0.57 for women) but not with AVT, while HNp II correlated with AVP (rs = 0.52 for men and 0.53 for women) and OT (rs = 0.92 for men and 0.50 for women) but not with AVT. This study thus confirms the presence of two neurophysins in the human pineal gland and further indicates that they are related to AVP and OT concentrations in the same gland. The results also imply, however, that the presence of immunoreactive AVT (more probably a closely related peptide) is independent of the neurophysins.

Peripheral neurophysins changes under mild stress conditions

Total immunoreactive neurophysins levels increased significantly in rats after they had been trained in a situation based on the innate light-dark avoidance principle. These levels varied according to the amount of 'familiarisation cues' which characterised the situation. The results are discussed in terms of arousal/stress-neurophysins relationships.