The use of gemeprost pessaries to arrest postpartum haemorrhage.
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Adult↗
Biomedical subjects
A Roberts
Publications and source records attributed to A Roberts.
Determinants of birth-weight in women with established and gestational diabetes.
Increased birth-weight (macrosomia) can complicate the diabetic pregnancy, but many factors other than hyperglycaemia can influence birth-weight, in particular maternal obesity. In a mixed population (European, Maori and Pacific Islander) with a high prevalence of glucose intolerance and obesity we have examined the relative impact of various maternal factors on birth-weight in women with both established and gestational diabetes. Mean birth-weight was significantly greater in women with established or gestational diabetes than in controls (p < 0.0001), but was similar in women with gestational and established diabetes, despite glycaemic control being significantly poorer (p < 0.0001) in the latter. Birth-weight closely paralleled prepregnancy body mass index rather than glycaemic control, but in Maori women it was lower than expected, probably because of their high prevalence of smoking. Daily cigarette consumption was negatively correlated with birth-weight (p < 0.01) despite the smokers having significantly poorer glycaemic control (p < 0.001). The most significant variables influencing birth-weight in the diabetic pregnancy were gestational age at delivery, prepregnancy body mass index, maternal height, estimated weight gain during pregnancy, the presence of hypertension and cigarette smoking (the latter 2 having negative effects on birth-weight). Glycaemic control in the last half of pregnancy was not significant in this analysis. We conclude that within the limits of glycaemic control which we obtained, birth-weight was largely determined by maternal factors other than hyperglycaemia. Birth-weight thus has severe limitations as an outcome measure of the diabetic pregnancy.
Adult↗
Control of frequency during swimming in Xenopus embryos: a study on interneuronal recruitment in a spinal rhythm generator.
1. In Xenopus embryos, the frequency of natural and fictive swimming usually drops slowly as swimming continues but can increase following stimulation of the skin or dimming of the illumination. We have investigated whether such increases are associated with an increase in the number of neurones active at higher frequencies. 2. Recordings from ventral presumed motoneurones show that these were reliably active at all swimming frequencies. 3. Recordings from more dorsal presumed interneurones showed that in the majority of these firing probability decreased as a function of swimming frequency. Dye-filled microelectrodes were used to show that some of these neurones had the anatomy of known classes of excitatory and inhibitory premotor interneurones. 4. If skin stimulation is given at appropriate phases of the swimming cycle, it can lead to a transient increase in frequency. Recordings from silent premotor interneurones during such stimulation show that they can be recruited to fire during the post-stimulus frequency increases. 5. It was possible that spike failure in the interneurones could have been due to damage by the recording microelectrodes. We therefore measured the amplitudes and probability of occurrence of rhythmic 'on-cycle' IPSPs which occur in sensory interneurones and 'on-cycle' IPSPs which sometimes occur in motoneurones during fictive swimming. Both decreased in amplitude and could fail as frequency dropped, providing further evidence that the number of inhibitory interneurones firing on each cycle of swimming is a function of frequency. 6. We conclude that premotor rhythm-generating interneurones are not active on all cycles of swimming and that their probability of firing action potentials increases with swimming frequency. This suggests that swimming frequency is determined in part by the number of premotor interneurones which are active.
Animals↗
Timing of antibiotic administration in knee replacement under tourniquet.
Cephamandole levels in serum and drain fluid were measured in 32 knee replacement operations to determine the benefit of an intravenous dose of antibiotic at the time of tourniquet deflation. Concentrations of cephamandole in drain fluid were directly proportional to the serum concentration at the time of tourniquet release. A 'tourniquet-release' dose of antibiotic increased drain fluid concentration threefold.
Cefamandole↗
Open learning--identifying the demand within midwifery education.
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Education, Nursing, Continuing↗
Isolated fetal pleural effusion: a prenatal management dilemma.
OBJECTIVE: To determine the etiology, pregnancy complications, and outcome of isolated fetal pleural effusion diagnosed antenatally and to evaluate the benefits of prenatal fetal interventions. DATA SOURCES: A literature search of MEDLINE was performed for relevant English language publications between 1985-1991. In addition, reference lists of articles were used to identify reported cases of isolated fetal pleural effusion. METHODS OF STUDY SELECTION: Our search uncovered 31 papers published in peer review journals. From these reports, 82 cases met our selection criteria: All fetuses were diagnosed antenatally with pleural effusion and had no other signs of hydrops at initial diagnosis. DATA EXTRACTION AND SYNTHESIS: The etiology of isolated fetal pleural effusion was unknown in most cases. Possible causes included congenital chylothorax, goiter, lung tumors, and infection. Cardiac defects (4.9%), Down syndrome (4.9%), and polydactyly (1.2%) may be associated with isolated fetal pleural effusion. Perinatal mortality was high (36%) and was related to the development of nonimmune hydrops, prematurity, and pulmonary hypoplasia. Early gestational age at diagnosis of isolated fetal pleural effusion (32 weeks or less) was associated with poor outcome and a neonatal death rate of 55%. In contrast, the neonatal death rate approached 31% as gestational age at diagnosis exceeded 32 weeks. Fifty-four cases were managed conservatively whereas 24 received intrauterine intervention, which included either pleuroamniotic shunt or repeated thoracenteses. Neonatal death rates were 37 and 33%, respectively. CONCLUSION: Not enough data exist to support either the conservative approach or intrauterine pleural drainage in cases of isolated fetal pleural effusion diagnosed antenatally.
Female↗
Enhanced learning experience--a progressive clinical experience.
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Clinical Competence↗
Has the process causing noninsulin dependent diabetes start at birth? Evidence in neonates from a population with a high prevalence of diabetes.
AIMS: to investigate whether differences in the glucose-insulin axis are present at birth in neonates from ethnic groups at high risk of diabetes. METHODS: fructosamine samples were taken from Maori, European and Pacific Island expectant mothers at their 28 week appointment at the public outpatients clinic at National Women's Hospital, Auckland. Umbilical cord samples for insulin, C-peptide and fructosamine assay were taken at delivery and babies had their subscapular skinfold fat thickness measured by callipers. RESULTS: the mean maternal 28 week fructosamine was similar in the three populations in spite of a higher prevalence of gestational diabetes among Pacific Islanders. Of the 1066 deliveries, cord samples were available for 207 Europeans, 81 Maoris and 113 Pacific Islanders. Both Pacific Island and Maori babies had higher cord fructosamine concentrations than European babies. However, Pacific Island babies were also heavier, and had higher cord insulin concentrations and subscapular skinfold thickness than European babies. CONCLUSIONS: the elevated cord fructosamine concentrations suggest that Maori and Pacific Island babies, who share a high risk of noninsulin dependent diabetes mellitus later in life, are hyperglycaemic at birth. The paradoxical insulin results and the cause for the relative neonatal hyperglycemia warrant further investigation.
Adult↗
Persistent rubella-specific IgM reactivity in the absence of recent primary rubella and rubella reinfection.
Between two and seven sera from cases of persistent detection of rubella-specific IgM for periods in excess of 2.5 months, but in the absence of recent primary rubella or rubella reinfection, were examined for rheumatoid factor, heterophile antibody, and IgM reactivity against toxoplasma and a number of viruses. The relative avidity of the rubella-specific IgG1 has been assessed in all the sera by two methods. None of the sera contained rheumatoid factor or heterophile antibody, nor did any contain detectable concentrations of IgM specific for any of the panel of antigens apart from five sera which contained low concentrations of IgM specific for some coxsackieviruses B. No sera were positive for low avidity specific IgG1 although three did give equivocal results with one avidity test and one gave equivocal results with the second avidity test.
Animals↗
The stopping response of Xenopus laevis embryos: behaviour, development and physiology.
1. When Xenopus laevis embryos swim into an obstruction they usually stop. This stopping response to stimulation on the head is present from stage 28 to 45. At stage 37/38 it is more reliable in restrained than in free-swimming animals, and to stimuli to the cement gland than to the head skin. 'Fictive' swimming also stops reliably after the same stimuli but struggling and 'fictive' struggling do not. 2. Discharge of deformation-sensitive trigeminal sensory neurons in response to pressure on the cement gland or head skin precedes the 'fictive' stopping response. When the embryo hangs from cement gland mucus, trigeminal neurons are active and the embryo is less responsive to stimulation. 3. Lesions of the central nervous system have allowed us to draw the following conclusions about this inhibitory pathway: (a) either the cement gland or the head skin must be intact; (b) one trigeminal ganglion is both sufficient and necessary; (c) the pathway is independent of the forebrain and midbrain; (d) it can take an ipsilateral or contralateral route through the hindbrain; (e) at least two hindbrain interneuron components are involved. 4. A similar stopping response is present in embryos and larvae of the urodele Ambystoma mexicanum.
Ambystoma mexicanum↗
In vivo microscopy of rat skeletal muscle after ischemia using labelled neutrophils (PMN).
Neutrophils (PMN) have been implicated as mediators of the "no-reflow" phenomenon seen in skeletal muscle during reperfusion after ischemia. In order to evaluate the PMN contribution to the changes seen in the microcirculation of skeletal muscle after ischemia, we evaluated PMN velocity using in vivo microscopy in a rat model. After the induction of anesthesia, the right iliac and femoral arteries were isolated. The right anterior tibialis muscle was exposed in situ, covered with a plexiglass disc, and perfused with Kreb's solution. Fluorescein-labeled bovine albumin was given intravenously, which identified the capillaries under microscopic magnification as viewed on the video screen. Acridine orange was then administered intravenously, which selectively fluoresced the PMN. The right iliac and femoral arteries were clamped for ischemia intervals of 5, 10, 15, 20, 25, and 30 min. Acridine orange was given immediately after the arteries were unclamped, after 30 min of reperfusion and after 60 min of reperfusion. PMN velocity was determined by the distance traveled by the PMN over time using the videotape and frame-by-frame review. Results demonstrated no change in PMN velocity (mm/sec) after 5 min of ischemia. After 10, 15, and 20 min of ischemia, PMN velocity initially slowed and then recovered, which was not statistically significant. After 25 min of ischemia, PMN velocity decreased significantly, which persisted (P < 0.05 compared to 5-min ischemia by ANOVA). No flow was seen after 30 min of ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
Analysis of Variance↗
Host factors and breast cancer growth characteristics.
The rate of growth and spread of breast cancer varies considerably from patient to patient. An observational study was undertaken to identify possible associations between breast cancer growth characteristics and a wide variety of host factors, including demographic, anthropometric, hormonal and dietary variables in 91 patients with breast cancer. Increasing age was associated with favourable growth characteristics, while previous tonsillectomy was associated with adverse growth characteristics. There were no significant associations in anthropometric variables. For postmenopausal women, increasing bioavailability of oestradiol was associated with favourable growth characteristics, while increasing prolactin concentration was associated with adverse growth characteristics. Increasing consumption of sugar, fibre, fruit and vegetables and vitamins was associated with favourable growth characteristics. Consumption of fat (monounsaturated and saturated) was associated with adverse characteristics when adjustment was made for total energy intake. The host environment may play a role in the control of breast cancer growth. In particular, the associations with oestrogen and progesterone receptor status indicate that nutrients may be of value as biological response modifiers in patients having hormonal therapy. This requires further investigation to assess therapeutic potential.
Age Factors↗
The effect of olfactory stimulation on fluency, vividness of imagery and associated mood: a preliminary study.
Twenty-two subjects were asked to visualize positive and negative phrases following exposure to either chamomile oil or placebo. Chamomile oil significantly increased the latency for all images, and shifted mood ratings and frequency judgements in a more positive direction, suggesting a possible mode of action for such oils.
Adult↗
Determinants of failure in superficial femoral artery angioplasty.
Although results of iliac artery balloon angioplasty have been shown to be good, there are much less data regarding initial success and durability of superficial femoral artery (SFA) dilation. The authors retrospectively reviewed the results of 22 patients treated for 27 SFA lesions between 1981 and 1986. Mean age was 64.5 years (fifty-five to seventy-six). Results were analyzed with respect to initial, early (< twelve months), and late (> twelve months) angiographic and clinical success. Indications were claudication (22), nonhealing ulcer (3), and rest pain (2). Mean follow-up was 30.9 months; 100% at one year and 92% at two years. Initial failure occurred in 9 (33%) lesions. There were 2 early and 2 late failures for a cumulative patency rate of 90.3% and 78% at one and two years, respectively. Predictors of clinical failure were: (1) initial--age, SFA occlusion, and angioplasty rating; (2) early--age, SFA occlusion, degree of atherosclerosis, and angioplasty rating; (3) late--angioplasty rating. There were 3 complications (11%). The authors conclude that: (1) 33% of attempted SFA angioplasties were initially unsuccessful and that the cumulative patency rate was 78% at two years. (2) Age is predictive of initial and early failure; SFA occlusion, of initial and early failure; degree of atherosclerosis, of early failure; and angioplasty appearance, of initial, early, and late failures. (3) Complications did not result in limb loss or require surgery.
Age Factors↗
The stopping response of Xenopus laevis embryos: pharmacology and intracellular physiology of rhythmic spinal neurones and hindbrain neurones.
1. Xenopus laevis embryos stop swimming in response to pressure on the cement gland. This behaviour and 'fictive' stopping are blocked by bicuculline (10 mumol 1(-1)), tubocurarine (110 mumol 1(-1)) and kynurenic acid (0.5 mmol 1(-1)). 2. Intracellular recordings from spinal neurones active during swimming have shown that pressure on the cement gland evokes compound, chloride-dependent inhibitory postsynaptic potentials (IPSPs). These are blocked by bicuculline, tubocurarine and kynurenic acid, but are unaffected by strychnine (2 mumol 1(-1)). 3. When the cement gland is pressed, trigeminal ganglion activity precedes both the IPSPs and the termination of 'fictive' swimming activity recorded in rhythmic spinal neurones. The trigeminal discharge is unaffected by the antagonists bicuculline, tubocurarine, kynurenic acid and strychnine. 4. Intracellular recordings from the hindbrain have revealed neurones that are normally silent, but rhythmically inhibited during 'fictive' swimming. In these neurones pressure on the cement gland evokes depolarising potentials, often with one or more spikes. 5. We propose that the stopping response depends on the excitation of pressure-sensitive trigeminal receptors which innervate the cement gland. These release an excitatory amino acid to excite brainstem GABAergic reticulospinal neurones, which inhibit spinal neurones to turn off the central pattern generator for swimming. There may also be a less direct pathway.
Animals↗
Search for cross-reactive idiotypes on monoclonal and myasthenia gravis acetylcholine receptor antibodies.
Myasthenia gravis patients have serum anti-acetylcholine receptor antibodies that compete with monoclonal antibodies for binding to epitopes on the human acetylcholine receptor. To investigate the presence of shared idiotypes we immunised syngeneic mice with each of ten well-characterised monoclonal antibodies, previously raised against purified human acetylcholine receptor, and tested the polyclonal antisera and seven monoclonal anti-idiotype antibodies, for binding to the antigen-combining site, to framework idiotopes, and by ELISA. The polyclonal sera were mostly directed against antigen-combining site idiotopes and cross-reacted only with monoclonal anti-acetylcholine receptor antibodies that bound to the same region on the acetylcholine receptor. In contrast, five of the seven IgM monoclonal anti-idiotypic antibodies raised, none of which demonstrated antigen-combining site specificity in solution, cross-reacted with mAbs binding to more than one region. None of the antisera showing reactivity with the antigen-combining site inhibited the binding of MG anti-acetylcholine receptor antibody.
Animals↗
Operative color Doppler imaging for vascular surgery.
Operative color Doppler imaging (CDI) was performed during 57 vascular operations (24 carotid, 24 lower extremity, six renal artery, and three other operations), and its benefits were assessed in comparison to B-mode imaging. Pre-reconstruction operative CDI was used selectively in 18 operations, and post-reconstruction operative CDI was used routinely in all operations. In 16 operations (28.6%), post-reconstruction CDI diagnosed vascular defects such as intimal flaps (n = 4), anastomotic stenoses (n = 7), and in situ bypass arteriovenous fistulas (n = 4). Vascular defects at eight operations required immediate repair. Operative CDI had advantages over B-mode imaging in (1) detection of preoperatively unknown vascular abnormalities before reconstruction, (2) faster recognition of vascular defects after reconstruction, (3) unique ability to detect problems (i.e., arteriovenous fistulas) that were unidentifiable by B-mode imaging, and (4) provision of supplemental blood flow information.
Blood Flow Velocity↗
The role of premotor interneurons in phase-dependent modulation of a cutaneous reflex during swimming in Xenopus laevis embryos.
Phase-dependent reflex modulation during fictive "swimming" in Xenopus laevis embryos has been examined with intracellular recordings from rhythmically active spinal neurons. (1) At rest, cutaneous trunk or tail skin stimulation evokes EPSPs in motoneurons and premotor excitatory and inhibitory interneurons of the opposite motor system. During swimming, these EPSPs can only be evoked during the depolarized phase of activity and can then produce extra action potentials that lead to phase-dependent reflexes in ventral roots. On the stimulated side, IPSPs are evoked in rhythmic neurons that can block centrally generated action potentials if the stimulus coincides with the inhibited phase of the swimming cycle. This inhibition suppresses ventral root discharge in a phase-dependent manner. (2) The presence of premotor interneurons in the crossed reflex pathway suggests two parallel routes for cutaneous excitation to reach the motoneurons, one direct and the other indirect through excitatory premotor interneurons. During swimming, the crossed excitation through both routes is gated by the rhythm-generating circuit to allow summation in motoneurons only during the depolarized phase of the swim cycle. (3) Following phase-dependent reflexes, the frequency of swimming is raised for several cycles, a phenomenon that requires sensory activation of premotor rhythm-generating interneurons. The results provide evidence on the role of identified premotor spinal interneurons in phase-dependent reflex modulation.
Animals↗