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Introduction Transgender people have specific healthcare needs and experience difficulty in accessing health services. Medical students should receive teaching on general and gynaecological healthcare issues in this population. Our aim was to assess medical students' knowledge of healthcare needs of transgender people before and after a newly implemented teaching session on transgender healthcare. Method A mixed-method study was carried out over a three month period in a university obstetric and gynaecology hospital in Dublin. A one-hour teaching session was developed and delivered to final year medical students. Students completed a survey before and after receiving the lecture. Results Seventy-one students completed the pre-lecture survey and forty-three completed the post-lecture survey. Pre-lecture, 64 students (90%) reported some-to-no understanding of healthcare issues of transgender people, and only 13 (18%) reported understanding gynaecological issues faced by transgender people. Post-lecture, 41 (95%) had a better understanding of health issues faced by this population and 40 (93%) had a better understanding of gynaecological health issues faced. Most students (81%) wanted further teaching on the topic. Conclusion A one-hour teaching session was effective at improving student knowledge of care of transgender people. This teaching could be expanded to all Irish medical schools. Going forward, the teaching could be adapted for post-graduate obstetric and gynaecology teaching.

Introduction The World Health Organisation has identified air pollution as the single biggest environmental threat to human health. There is growing evidence in the literature that air pollution is associated with negative outcomes in pregnancy. The purpose of this study was to measure pollution levels in the immediate surroundings of the three Dublin maternity hospitals by measuring fine particulate matterlt;2.5 micrometres (PM2.5). Methods Data pertaining to levels of PM2.5 at the three Dublin maternity hospitals were obtained from Pollutrack's records for the time period 25/6/2021-2/12/2021. Results were compared to the 2021 WHO Air Quality Guidelines. Results Average PM2.5 levels were 9μg/m³ around the National Maternity Hospital, 10μg/m³ around the Coombe Hospital and 13μg/m³ around the Rotunda Hospital. Levels were higher during the day, weekdays and in December. No matter when the PM2.5 levels were measured, results were higher than those recommended by the World Health Organisation's Air Quality Guideline. Discussion Air pollution levels across Ireland's capital city are higher than recommended by the WHO. This is concerning for the public and in particular for the pregnant population. Going forward, further research is required on the relationship between levels of air pollutants and adverse pregnancy outcomes in Dublin.

In the research concerning rational emotive behavior therapy (REBT) in sport and exercise, irrational beliefs are proposed as a risk factor for health. Concurrent to this, researchers have also indicated that autonomous and controlled motivation, as proposed in organismic integration theory could, together with irrational beliefs, could determine individual health. However, research is yet to align irrational beliefs and motivation, and explore how this alignment relates to mental health. The present two study paper identifies individual subgroups, drawn from data concerning irrational beliefs, motivation, and health (psychological distress, and physical health), in a sample of exercisers (study 1) and student athletes (study 2). We examined the latent profile structure of irrational beliefs and motivation, and how these latent profiles relate to psychological distress (studies 1 and 2), and physical health (study 2). Results indicate a two class profile whereby class 1 is characterised by high irrational beliefs, low self-determined motivation, and poor health outcomes. Class 2 is characterised by low irrational beliefs, high self-determined motivation, and better health outcomes. The findings are discussed in relation to the theoretical implications for REBT and organismic integration theory, and the practical implications for key stakeholders in the health of exercise participants and athletes.

Neural tube defects (NTD) are potentially preventable in two-thirds of cases by periconceptional maternal Folic Acid (FA) supplementation. A national audit for the years 2009-11 showed no decline in NTD rates over twenty years. The aim of this national audit was to determine trends/rates and inform revision of national FA supplementation and food fortification strategies. Of 274,732 live and stillbirths there were 121(42.0%) cases of anencephaly, 136(47.2%) cases of spina bifida and 31(10.8%) cases of encephalocoele giving a total of 288 and overall rate of 1.05/1000 compared with 1.04/1000 in 2009-11(NS). In the 184 women where the information was available, only 29.9%(n=55) reported starting FA before pregnancy. The number of cases diagnosed antenatally was 91%(n=262) and 53%(n=154) were live-born. This audit confirms that over a generation, healthcare interventions have not succeeded in decreasing the number of pregnancies in Ireland complicated by NTD, and that revised strategies need to be developed and implemented.

Neutron imaging has been employed in life sciences in recent years and has proven to be a viable technique for studying internal features without compromising integrity and internal structure of samples in addition to being complementary to other methods such as X-ray or magnetic resonance imaging. Within the last decade, a neutron imaging beamline, IMAT, was designed and built at the ISIS Neutron and Muon Source, UK, to meet the increasing demand for neutron imaging applications in various fields spanning from materials engineering to biology. In this paper, we present the first neutron imaging experiments on different biological samples during the scientific commissioning of the IMAT beamline mainly intended to explore the beamline's capabilities and its potential as a noninvasive investigation tool in fields such as agriculture (soil-plants systems), palaeontology and dentistry. LAY DESCRIPTION: Neutrons form a highly penetrating radiation passing through matter without damaging or structurally modifying it, a property that makes them the ideal tool for many kinds of complementary material investigations. Moreover, the strong interaction of neutrons with hydrogen and their ability to distinguish between hydrogen and deuterium with no radiation damage make neutrons a good probe for imaging biological specimens. The recent technological developments of sources and detectors improved the capabilities of neutron imaging instruments and also have facilitated the use of neutron imaging on a much wider scale than before. Neutron imaging is proving its advantages as being complementary to other known methods of investigation such as X-ray imaging or magnetic resonance imaging and it is no surprise that it is not only employed in engineering or archaeology, but also in life sciences. This definitely opens new perspectives for a more interdisciplinary approach in contemporary science. Within the last decade a neutron imaging beamline, IMAT, was designed and built at the ISIS Neutron and Muon Source, UK, to meet the increasing demands of researchers from different fields, spanning from materials engineering to biology. The results presented here, acquired from first measurements on different biological samples during the scientific commissioning of IMAT beamline show the instrument capability and its suitability to palaeontology, agriculture (soil-plants systems) or dentistry applications.

Obese women are more likely to require general anaesthesia for an obstetric intervention than non-obese. Difficult tracheal intubation and oxygen desaturation is more common in pregnancy. Failed tracheal intubation has been associated with an increase in neck circumference (NC). We studied the relationship between maternal obesity and NC as pregnancy advanced in women attending a standard antenatal clinic. Of the 96 women recruited, 13.5% were obese. The mean NC was 36.8cm (SD 1.9) in the obese women compared with 31.5cm (SD 1.6) in women with a normal BMI (p0.001) at 18-22 weeks gestation. In the obese women it increased on average by 1.5cm by 36-40 weeks compared with an increase of 1.6 cm in women with a normal BMI. The antenatal measurement of NC is a simple, inexpensive tool that is potentially useful for screening obese women who may benefit from an antenatal anaesthetic assessment.

In 2010, national guidelines for the management of gestational diabetes mellitus (GDM) were published by the Health Service Executive (HSE). In 2012, a questionnaire was distributed to all maternity units to survey implementation of the guidelines. All units screened women for GDM, but used different screening tests with fifteen units (79%) using the recommended 75g OGTT, three units (16%) using a 100g OGTT and one unit (5%) using a 50g glucose challenge test. Optimal outcomes are best achieved through multidisciplinary diabetes-obstetric care and this was available in nine of the units (47%). The prevalence of GDM varied from 2.2 - 7.4%. Insulin usage varied from 15-56%. Six centres (31%) had not implemented the national guidelines in full because of lack of resources. Despite national endorsement of the guideline, significant variations remain in implementation. This may lead to differences in clinical outcomes depending on where a woman attends for obstetric care.

Benzene is a ubiquitous environmental pollutant that is known to cause hematotoxicity and leukemia in humans. The initial oxidative metabolite of benzene has long been suspected to be benzene oxide (3,5-cyclohexadiene-1,2-oxide). During in vitro experiments designed to characterize the oxidative metabolism of [14C]benzene, a metabolite was detected by HPLC-radioactivity analysis that did not elute with other known oxidative metabolites. The purpose of our investigation was to prove the hypothesis that this metabolite was benzene oxide. Benzene (1 mM) was incubated with liver microsomes from human donors, male B6C3F1 mice, or male Fischer-344 rats, NADH (1 mM), and NADPH (1 mM) in 0.1 M sodium phosphate buffer (pH 7.4) and then extracted with methylene chloride. Gas chromatography-mass spectrometry analysis of incubation extracts for mice, rats, and humans detected a metabolite whose elution time and mass spectrum matched that of synthetic benzene oxide. The elution time of the benzene oxide peak was approximately 4.1 min, while phenol eluted at approximately 8 min. Benzene oxide also coeluted with the HPLC peak of the previously unidentified metabolite. Based on the 14C activity of this peak, the concentration of benzene oxide was determined to be approximately 18 microM, or 7% of total benzene metabolites, after 18 min of incubation of mouse microsomes with 1 mM benzene. The metabolite was not observed in incubations using heat-inactivated microsomes. This is the first demonstration that benzene oxide is a product of hepatic benzene metabolism in vitro. The level of benzene oxide detected suggests that benzene oxide is sufficiently stable to reach significant levels in the blood of mice, rats, and humans and may be translocated to the bone marrow. Therefore benzene oxide should not be excluded as a possible metabolite involved in benzene-induced leukemogenesis.

The objective of the study was to identify those women attending for antenatal care who would have benefited from prepregnancy rubella vaccination. It was a population-based observational study of women who delivered a baby weighingor = 500 g in 2009 in the Republic of Ireland. The woman's age, parity, nationality and rubella immunity status were analysed using data collected by the National Perinatal Reporting System. Of the 74,810 women delivered, the rubella status was known in 96.7% (n = 72,333). Of these, 6.4% (n = 4,665) women were not immune. Rubella seronegativity was 8.0% (n = 2425) in primiparous women compared with 5.2% (n = 2239) in multiparous women (p0.001), 14.7% (n = 10653) in women25 years old compared with 5.0% (n = 3083) in womenor = 25 years old (p0.001), and 11.4% (n = 780) in women born outside the 27 European Union (EU27) countries compared with 5.9% (n = 3886) in women born inside the EU27 countries (p0.001). Based on our findings we recommend that to prevent Congenital Rubella Syndrome, the health services in Ireland should focus on women who are young, nulliparous and born outside the EU.

Gestational diabetes mellitus (GDM) has important maternal and fetal implications. In 2010, the Health Service Executive published guidelines on GDM. We examined the impact of the new guidelines in a large maternity unit. In January 2011, the hospital replaced the 100 g Oral Glucose Tolerance Test (OGTT) with the new 75 g OGTT. We compared the first 6 months of 2011 with the first 6 months of 2010. The new guidelines were associated with a 22% increase in women screened from 1375 in 2010 to 1679 in 2011 (p0.001). Of the women screened, the number diagnosed with GDM increased from 10.1% (n=139) to 13.2% (n=221) (p0.001).The combination of increased screening and a more sensitive OGTT resulted in the number of women diagnosed with GDM increasing 59% from 139 to 221 (p = 0.02).This large increase has important resource implications but, if clinical outcomes are improved, there should be a decrease in long-term costs.

We reviewed the outcome of fetal hydronephrosis with a renal pelvic dilatation (RPD) of 4-7 mm to assess whether a RPD7 mm had a higher predictive value for renal pathology. 373 fetuses were diagnosed with hydronephrosis giving an incidence of 2.2%. The male: female ratio was 1.8:1. 5(1.34%) fetuses with antenatal hydronephrosis were diagnosed with Down Syndrome. 299 (91.7% fetuses with an RPD of 4-7 mm had resolved by 34 weeks gestation with 10 (3.1%) having moderate to severe hydronephrosis. The resolution rate for RPD7 mm was 60.7% (17) with 11 fetuses (39.3%) requiring long term follow up.

Thromboprophylaxis for women undergoing caesarean section (CS) was introduced in the hospital in 1995. This study audited the use of tinzaparin prophylaxis in a nested cohort of women who screened negative for diabetes mellitus at 28 weeks gestation. All the women had their weight measured and BMI calculated at the first antenatal visit. Of the 284 women, 68 (24%) had a CS and all received tinzaparin. Of the 68, however, 94% received a dose lower than recommended. Compliance with prophylaxis was complete but compliance with the recommended dosage was suboptimal, which may result in venous thromboembolism after CS despite thromboprophylaxis.

Appropriate nutrition in pregnancy is fundamental for maternal and fetal health, and the long-term physiological wellbeing of the offspring. We aimed to determine whether a sample of pregnant women met the national guidelines for healthy eating during pregnancy, and to examine if compliance differs when analysed by Body Mass Index (BMI) category. Subjects completed a 24-hr dietary recall, and had their BMI calculated. The mean age was 27.8 years. The mean BMI was 25.1 kg/m2, with 32 (31.7%) subjects overweight and 14 (13.9%) obese based on BMI category. Although the majority of subjects thought that they had a healthy diet, less than half met the recommended guidelines for each individual food group with achievement of the dairy group being particularly low. Achievement of food group recommendations was not influenced by BMI category. Public health messages on healthy eating guidelines need to be clearly communicated to pregnant women.

Intrauterine fetal growth restriction (IUGR) is an important pregnancy complication associated with significant adverse clinical outcome, stillbirth, perinatal morbidity and cerebral palsy. To date, no uniformly accepted management protocol of Doppler surveillance that reduces mortality and cognitive morbidity has emerged. Aortic isthmus (AoI) evaluation has been proposed as a potential monitoring tool for IUGR fetuses. In this review, the current knowledge of the relationship between AoI Doppler velocimetry and preterm fetal growth restriction is reviewed. Relevant technical aspects and reproducibility data are reviewed as we discuss AoI Doppler and its place within the existing repertoire of Doppler assessments in placental insufficiency. The AoI is a link between the right and left ventricles which perfuse the lower and upper body, respectively. The clinical use of AoI waveforms for monitoring fetal deterioration in IUGR has been limited, but preliminary work suggests that abnormal AoI impedance indices are an intermediate step between placental insufficiency-hypoxemia and cardiac decompensation. Further prospective studies correlating AoI indices with arterial and venous Doppler indices and perinatal outcome are required before encorporating this index into clinical practice.

Bowel habit in 57 rectal prolapse patients was assessed before and after abdominal Ivalon rectopexy. There was a significant (chi-square = 8.7, P less than 0.01) increase in prevalence of constipation from 30 percent before to 51 percent after surgery. There were two explanations for this increased constipation. It was mainly the result of a 28 percent increase in prevalence of constipation among patients who were incontinent before rectopexy. Incontinent prolapse patients were more likely to acquire a predictable bowel habit after rectopexy if they became constipated. There was also a small (7 percent) increase in prevalence of constipation among continent patients, which could be attributed to the rectopexy procedure. In a subgroup of 15 patients, rectal wall thickness after rectopexy was assessed by pelvic computed tomographic scan carried out before and after surgery, or at more than one year after surgery. There was a significant (t = 4.5, P less than 0.001) increase in rectal wall thickness by 24 weeks after rectopexy, compared with before operation. This increase was also seen in a further five patients undergoing abdominal rectopexy without Ivalon sponge, suggesting that it was a consequence of rectal mobilization rather than the Ivalon sponge. This increased rectal wall thickness may impede the passage of formed stool into the lower rectum and contribute to the increased constipation found after rectopexy.

Respiratory dead-space is often increased in lung disease. This study evaluates the effects of increased alveolar dead-space (Vd(alv)), pulmonary shunt, and abnormal ventilation perfusion ratio (/) distributions on dead-space and alveolar partial pressure of carbon dioxide (Pa(co(2))) calculated by various methods, assesses a recently published non-invasive method (Koulouris method) for the measurement of Bohr dead-space, and evaluates an equation for calculating physiological dead-space (Vd(phys)) in the presence of pulmonary shunt.Pulmonary shunt, / distribution and Vd(alv) were varied in a tidally breathing cardiorespiratory model. Respiratory data generated by the model were analysed to calculate dead-spaces by the Fowler, Bohr, Bohr-Enghoff and Koulouris methods. Pa(co(2)) was calculated by the method of Koulouris.When Vd(alv) is increased, Vd(phys) can be recovered by the Bohr and Bohr-Enghoff equations, but not by the Koulouris method. Shunt increases the calculated Bohr-Enghoff dead-space, but does not affect Fowler, Bohr or Koulouris dead-spaces, or Vd(phys) estimated by the shunt-corrected equation if pulmonary artery catheterization is available. Bohr-Enghoff but not Koulouris or Fowler dead-space increases with increasing severity of / maldistribution. When alveolar Pco(2) is increased by any mechanism, Pa(co(2)) calculated by Koulouris' method does not agree well with average alveolar Pco(2).Our studies show that increased pulmonary shunt causes an apparent increase in Vd(phys), and that abnormal / distributions affect the calculated Vd(phys) and Vd(alv), but not Fowler dead-space. Dead-space and Pa(co(2)) calculated by the Koulouris method do not represent true Bohr dead-space and Pa(co(2)) respectively, but the shunt-corrected equation performs well.

To assess the acceptability of antenatal HIV testing. A questionnaire based study. Obstetric outpatient clinic at the Portiuncula Hospital, Galway, Ireland. Women attending the antenatal clinic between May and November 2000. The participating women received pamphlets explaining HIV testing in pregnancy before completing the questionnaire. The questions included assessment of their views towards prenatal HIV testing, perceived benefits and acceptability. Seven hundred and forty-eight questionnaires were distributed. Of these 715 (96%) completed questionnaires were returned out of which 32 (4.5%) were discarded because they were improperly completed. 683 (96%) correctly completed questionnaires were analysed. 650 (95.2%) women agreed that prenatal HIV testing was a good idea and that test was necessary, 17 (2.5%) said test was not a good idea, 30 (4.4%) said test was unnecessary and 16 (2.3%) and 3 (0.4%) women were unsure whether or not test was a good idea and necessary respectively. Three hundred and sixty two (53%) women were of the opinion that prenatal HIV testing was of benefit to the mother and her baby; 301 (44%) to the mother, baby and the health workers; 14 (2%) to the baby; and 3 (0.4%) only to the mother. Only 3 (0.4%) women reported that prenatal HIV testing was of no benefit. The majority of the women, 436 (63.8%) had second level education, 202 (29.6%) received third level and 45 (6.6%) had only primary education. Antenatal HIV testing is acceptable to the majority of the obstetric population studied.

A split study evaluated the ThinPrep(R) PapTesttrade mark (TP; Cytyc Corp., Boxborough, MA) compared with current methodologies of cervical cytology in two high-risk cohorts. One thousand, three hundred cases from a colposcopy clinic and a genito-urinary medicine outpatient clinic were examined. The TP reported increased detection of all grades of dyskaryosis (mild, moderate and severe; + 4.5%) and a decrease in borderline and unsuitable cases (- 4.9%). Four cases of high-grade dyskaryosis (moderate or severe) were detected only using the TP, while an additional four cases classified as high-grade dyskaryosis with the TP were reported as borderline by our conventional methods. The split-study finding of increased sensitivity with the TP provides for improved clinical management of patients in our high-risk cohorts.

Amplitude and phase frequency response characteristics of infant air-balloon catheters (IABC) of differing French gauge (FG) sizes and brands were quantified to determine their suitability for measuring dynamic intra-esophageal pressure (Pes) accurately. Frequency response performances of matching IABC and water-filled catheters (WFC) were also compared using the swept sine wave technique. The maximum respiratory rate within which IABCs could potentially measure Pes within a 5% error limit was calculated (FRR). Frequency responses of IABCs greater than FG size 5 exhibited underdamped resonant properties, while smaller FG size IABCs exhibited near-critical damping or overdamping. IABCs maintained uniform amplitude frequency responses up to 25 Hz, demonstrating the ability to measure Pes potentially up to 148 breaths/min within a 5% error limit. The frequency response performance of FG size 6 IABCs was similar to that of FG size 10 IABCs. Compared with matching WFCs, the frequency response performance of IABCs was significantly superior, the frequency response variability within IABC samples was lower, and IABC correlation between FG size and FRR was advantageously lower than for WFCs. FRR values for differing IABC brands and FG sizes are presented. We conclude that IABCs manufactured to infant-appropriate balloon specifications exhibit significantly superior frequency response characteristics compared with matching WFCs. Measurement accuracy is not improved using IABCs greater than FG size 6. Inexpensive intra-esophageal IABCs are technical suitable for the accurate measurement of dynamic Pes during high-frequency respiratory mechanics encountered during infant artificial ventilation.

Polyvinyl chloride (PVC) nasogastric feeding catheters are used clinically to measure intraesophageal pressure as an estimate of pleural pressure for calculating lung compliance in infants. The accuracy of pressure measurement of 4 French gauge (FG) catheter sizes and three brands of liquid-filled catheter manometer systems (CMS) was evaluated by determining their resonance-frequency amplitude and phase properties. All CMS were underdamped and resonated. No CMS exhibited a uniform mean frequency response above 11 Hz. The maximum respiratory rate (Frr) within which CMS could potentially measure dynamic intraesophageal pressure within a 5% error limit was determined (Frr): the highest mean Frr recorded reliably in large-diameter catheters was 82 breaths/min. Significant CMS differences in accuracy existed between catheter FG sizes and between catheters of similar diameters but differing brands. Correlation (r2) between catheter inner diameter and CMS Frr was 0.66 across brands. In conclusion, intraesophageal PVC liquid-filled feeding catheters are suitable for estimating pleural pressures in subjects mechanically ventilated without sharp inspiratory waveforms or high respiratory rates. Quantitative frequency response characterization of different nasogastric catheter brands and different diameters is mandatory prior to their utilization.

In order to determine which formula most accurately predicts weight in Irish infants we performed a prospective study on 162 mothers within one week of delivery. Actual weights were compared with estimated weights derived from the formulae of Shepard; Hadlock; Birnholtz; Deter and Campbell. Overall the Deter formula gave the closest approximation of birth weight. All the formulae became increasingly inaccurate in the larger infants i.e.4 kg. However in infants of average weight the Campbell formula, which is based on a single measurement (A.C), is as good as any.

In an attempt to determine whether the lactate threshold (LT) is the result of a sudden increase in plasma epinephrine (Epi), eight healthy college-aged males (22.4 +/- 0.4 yr) were recruited to perform three cycle ergometer exercise tests. Each subject performed a graded exercise test (GXT) to determine LT, Epi threshold, and norepinephrine threshold (64.6 +/- 2.4, 62.5 +/- 2.4, and 60.8 +/- 4.3% peak oxygen uptake, respectively). Each subject also completed, in random order, two 30-min submaximal (20% peak oxygen uptake below LT) exercise tests. During one test, graded Epi infusions were carried out at rates of 0.02–0.12 micrograms.kg-1.min-1; the other served as a control test. Infusion resulted in plasma Epi concentrations similar to those observed during GXT. The increase in blood lactate with Epi infusion was significantly greater than that during the control test (3.0 +/- 0.3 vs. 1.4 +/- 0.1 mmol/l at minute 30) but did not approach levels exhibited during GXT. We suggest an interaction of the increasing plasma Epi with other factors may be responsible for the sudden increase in blood lactate during graded exercise.

A series of hysterectomies performed during labor or shortly after delivery, all as emergencies is reported. The study covered the ten years 1982-1991, during which 65,488 deliveries resulted in infants with a birth weight of 500 g or more. There were no hysterectomies among the 21,998 primipara, the incidence in multipara being 1 per 3,954 deliveries. Five operations were performed for rupture of the uterus and six for cataclysmic bleeding. Seven of the 11 patients had history of caesarean section. In multipara, the existence of a caesarean scar multiplied the risk of emergency hysterectomy by a factor of 18. There were no maternal deaths but all patients required transfusion with more than 6 units of packed cells. These results emphasize the fact that a history of caesarean is the principal etiologic factor in patients experiencing complications of pregnancy which require emergency peri-partum hysterectomy.

The objectives of this study were to identify, by means of two third-trimester scans, fetuses with ultrasound evidence of inadequate growth but who were born with birth weights above the 10th centile for gestational age; and to determine if these infants constitute a high-risk group by comparing the incidence of obstetric intervention, of intrapartum complications and of neonatal morbidity between this group and the group of infants who showed no ultrasound evidence of intrauterine growth restraint. A total of 285 women with singleton pregnancies who were referred for a third-trimester ultrasound examination were included in this prospective study. Fetal weight was estimated by ultrasound twice in the third trimester and at each examination was assigned a centile score. A fall of20 centiles was taken as evidence of inadequate growth. The outcomes measured were the incidence of abnormal umbilical artery Doppler, induction of labor, meconiumstaining of the liquor, intrapartum fetal blood sampling, operative vaginal delivery, Cesarean section, Apgar score of7 at 5 min and admission to the neonatal intensive care unit. Seventy-five patients showed a drop of20 centiles between the first and second scans. The incidence of admission to the neonatal intensive care unit was greater in those infants who had ultrasound evidence of growth restraint. We conclude that infants of normal birth weight with inadequate growth diagnosed on ultrasound are not at increased risk, they have an increased incidence of admission to the neonatal intensive care unit, and they are more commonly found in mothers with diabetes mellitus.

The dynamic characteristics of gas analysers are often assessed by measuring the step response. It is difficult to generate a verifiable instantaneous step change in gas composition. We constructed a 0.06 ml measurement chamber connected via high-speed valves (0.5 ms response time) to two 31 reservoirs pressurized to 50 kPa with gases containing different concentrations of CO2. An electronic system opens the valves alternately depending on the polarity of a control voltage Vc. Two walls of the chamber contain narrow-band infra-red filters centered at 4.24 microns (50% transmission points at 4.16 and 4.32 microns) where CO2 absorption is high. A photoconductive infra-red sensor and an infra-red source are positioned on either side of the chamber. The output of the sensor is amplified by an instrumentation amplifier. Signal averaging of the sensor output in either the time or frequency domain was used to overcome the noise of the infra-red sensor. Step changes in Vc yielded exponentially changing outputs with a time constant of 1.1 ms. A quadrupole mass spectrometer's response to step changes in CO2 concentration generated in the measurement chamber fitted single exponential curves well with a maximum time constant of 37.7 ms and transport delay of 194 ms. The frequency response of the infra-red system, from Vc to the sensor output, fell by 0.7 dB with a phase lag of 30 degrees between 1 and 50 Hz. Using the infra-red system to measure the true input to the mass spectrometer, the frequency response of the mass spectrometer was found to fall by 35 dB with a phase lag of over 3000 degrees between 0.2 and 50 Hz. A first-order model with delay fitted to the step response predicted the mass spectrometer frequency response well below 10 Hz but overestimated the response above 10 Hz. A third-order model with delay fitted to the frequency response predicted the step response very well. Our results suggest that low-order models cannot predict the high-frequency performance of a mass spectrometer.

A knife cone biopsy of the cervix is usually performed as an inpatient procedure under general anesthesia and is associated with significant morbidity. Loop diathermy conization was performed under local anesthesia on colposcopy outpatients as an alternative to knife conization. In 33 consecutive patients studied the procedure was well tolerated, there were no operative complications, and a satisfactory specimen for histologic examination was obtained in every case. One case of unsuspected invasive cancer and two of suspected microinvasive cancer were diagnosed. The diagnosis of cervical precancer was made in 24 (73%) of the cases. The introduction of outpatient loop diathermy conization of the cervix instead of knife conization would decrease hospitalization costs, avoid the need for general anesthesia and potentially reduce short-term patient morbidity.

Of 1433 consecutive patients who underwent mammography, 90 were subsequently found to have histologically confirmed carcinoma of the breast (85 invasive carcinoma, three lobular carcinoma in situ, two intraduct carcinoma). Sixty (67%) of the mammograms of the patients with cancer were reported correctly as carcinoma. There were 27 (30%) false negative reports and three (3%) equivocal reports. In 14 (16%) patients with false negative reports the biopsy was delayed by between 2 and 24 months. The false reassurance of the mammogram report was responsible for the delay in diagnosis in nine and may have contributed in the remainder. The mammogram was most likely to be misleading when used as an investigation for a palpable lump in the breast. The mean age of patients with a false negative mammogram (44 years) was significantly less than that of patients with a true positive mammogram (57 years). In 23 of the 60 patients with positive mammograms management was changed as a result of the investigation. The mammogram was most helpful when no breast lump was palpable and there was either some other clinical evidence of local malignancy (ten patients, 11%) or metastatic disease (three patients, 3%), or the mammogram had been performed to screen a high-risk patient (three patients, 3%). The positive mammogram was also useful in two patients with residual or recurrent disease following local excision of a breast cancer. There were 15 patients with bilateral breast cancer (17%). Three (3%) were diagnosed within 2 months of the first tumour but mammography did not contribute to the diagnosis of any of these.

A stratified sample of normal infants born at term at Johannesburg Hospital, who attended the hospital for a routine 6-week follow-up visit, were selected to include 43 infants who were exclusively breast-fed, 42 fed a low-sodium formula and 39 fed a high-sodium formula (greater than 10 mmol sodium/l). Dynamic skinfold thickness measurements (DSTM), designed to assess the amount of interstitial fluid, were performed on each infant by the application of a skinfold caliper for a 3-second sampling period at two sites. The curves generated by these applications were recorded and analysed by microcomputer. There were no differences between any of the feeding groups for DSTM measurements of blood pressure suggesting that the range of sodium ingested by these groups of infants had no significant effects on extracellular water content. However, using multiple linear regression, both DSTM and blood pressure were best predicted by body weight and not by age or any other anthropometric measurement. Thus the normal postnatal decrease in extracellular fluid volume and increase in blood pressure appears to be most closely related to an increase in body weight.

The purpose of this study was to examine the hypothesis that dystocia in nulliparas is directly related to birth weight. The study was confined to the first 1000 nulliparas delivered in 1988 who went into labor after 37 weeks' gestation with a single live fetus and cephalic presentation. The management of labor was standardized. As birth weight increased, there was an increase in the mean duration of labor and of the second stage of labor, in the incidence of oxytocin augmentation, and in the incidence of both cesarean and forceps delivery for dystocia. The direct relationship between birth weight and the mean duration of labor was independent of gestation and oxytocin augmentation. These findings suggest that birth weight is an important factor in the development of dystocia in nulliparas.

The value of population screening for cervical cancer has recently been questioned. The purpose of this study was to examine the cytological screening history in 100 consecutive patients undergoing Wertheim's hysterectomy for early invasive cervical cancer. Twenty three per cent of the patients were never screened; the screening history was unavailable in 11%; the patient was referred appropriately in 21%; there was a delay in referral for gynaecological assessment in 21%; the patient's previous cervical smear before referral was normal in 24%. If population screening in Ireland is to have an impact on mortality from cervical cancer, the results of this study indicate that greater attention needs to be given not only to extending the number of women screened, but also to increasing the frequency of screening and to improving the clinical response to an abnormal smear.

The management of pregnancy after 40 completed weeks remains controversial because induction of labour has been, in the past, associated with an increase in the incidence of caesarean section. This study examined the use of vaginal prostaglandin tablets for the induction of labour in selected primiparae after forty one weeks of pregnancy. The outcome of prostaglandin induction in 118 consecutive patients was compared with the outcome in 90 consecutive patients who went into labour spontaneously at the same gestation before induction could be undertaken. The active management of labour was applied in both groups and, therefore, the management of labour was strictly standardised. There was no difference between the two groups in the mode of delivery. Nor was prostaglandin induction associated with an increased incidence of prolonged labour. In selected primiparae, the cautious use of vaginal prostaglandin tablets can induce labour successfully postdates without increasing the complications of labour. A larger study is required to examine the effects of the induction of labour at this gestation on the fetal outcome.

Bacteriological examinations were performed on 1103 infants to determine the ages at which the newborn are colonized at different sites by bacteria, and with which organisms. On the day of birth, specimens for culture included aspirated gastric contents, and swabs from nose, throat, groin and rectum; on Day 3 the umbilical cord clamp with a section of the cord, swabs from nose, throat, groin and rectum; on days 5 and 1, and weekly thereafter, swabs from the same 4 sites. These examinations included identification of the individual bacterial species. The mass of information so obtained was analysed by computer. The high level of bacterial colonization by day 3 was striking and, indeed, large numbers of potential pathogens were grown from infants within one hour of birth. Staphylococcus aureus was found only in very small numbers of infants, e.g. only 2.6 per cent of infants' umbilical cords on day 3, and 4 per cent of infants' noses on day 7. If the levels of colonization reflect the risks of infection, Pseudomonas aeruginosa ranks close to Staph. aureus in the newborn nursery of the modern maternity hospital. Forty two different species of bacteria were isolated from these infants of which 24 were potential pathogens and of the latter, gram-negative organisms greatly outnumbered the gram-positive. This high incidence of gram-negative colonization in a large series of hospitalized neonates may be a normal phenomenon but it suggests that the risk of infection is today greater with gram-negative than with gram-positive bacteria. The figures for carriage of pathogenic staphylococci in the present investigation contrast markedly with the figures reported by many workers between 1950 and 1960.

We show that the technique of exciting a differential pressure transducer at one port to measure its differential gain yields incorrect results in the case of asymmetrical differential pressure transducers but is acceptable in the case of symmetrical transducers. We have measured the common-mode gain of a symmetrical and an asymmetrical differential pressure transducer from 1 Hz to 100 Hz, both directly and by computation from differential gain measurements. No compensation for common-mode error is necessary when a symmetrical transducer is used in mechanically ventilated neonates. We have also measured the frequency response of neonatal Fleisch and screen pneumotachographs connected to Validyne MP45 differential pressure transducers in air, 60% oxygen and 100% oxygen, and concluded that the effect of oxygen concentration is small below 40 Hz. However, the normalised frequency response of the flow transducer differs markedly from unity at frequencies inside the flow bandwidth generated by neonatal pressure cycled ventilators and dynamic correction is therefore necessary.

The incorporation of HLA antigens into liposomes is described. At and above the lipidphase-transition temperature, between 50 and 80% of the added antigenic activity may be incorporated into liposomes in the form of multilamellar vesicles. The antigen appears to be asymmetrically orientated with respect to the lipid bilayer.

Conventional chest tomography and fibreoptic bronchoscopy were performed in 100 patients with a localised chest abnormality on their chest radiographs who had been referred with a possible diagnosis of bronchial carcinoma. Carcinoma was eventually confirmed in 74 cases and in 26 the lesion proved to be benign. The accuracy of tomography in the overall series was 83%, with a sensitivity of 92% and a specificity of 58%. These figures compare favourably with the results of other imaging techniques used in the diagnosis of bronchial carcinoma. In 50 patients bronchoscopy did not suggest carcinoma and in this group of patients 24 had a carcinoma and 26 a benign lesion. The accuracy of tomography in the bronchoscopy negative patients was 74%, the major source of error being the false positive category. The lesion eventually proved to be benign in 33% of the cases where tomography suggested malignancy, but when the tomograms suggested that the lesion was benign a tumour was found to be present in only 12% of cases.

Thirty patients undergoing anterior resection of the rectum were randomized for postoperative drainage with either corrugated (N = 14) or corrugated plus Shirley sump drain (N = 16). Drainage volume per 24 hours was measured, and volume of residual pelvic fluid collection estimated by CT scan on the seventh postoperative day. A mean of 591.9 +/- 415.2 ml of fluid drained during the first seven postoperative days. There was a significant (P less than 0.01) increase in 24 hour drainage volume between the fourth and sixth postoperative days. There was no significant difference in drainage volumes between the two drainage methods. Residual pelvic fluid collection (median volume, 16 ml) was detected in 80 percent of patients at one week after operation. While this was larger (24 ml median) for the corrugated only group compared with the corrugated plus sump drain group (11.5 ml median), the difference was not significant. Fluid loss during the first postoperative week (616.6 +/- 424.2 ml) was significantly (P less than 0.05) less when the anastomosis was situated higher than 12 cm (294 +/- 192 ml) compared with 6 to 12 cm from the anal margin (496 +/- 210 ml), or after coloanal anastomosis (1077 +/- 432 ml). Residual pelvic fluid collection was larger after coloanal anastomosis (median, 33 ml; range, 1.5 to 90 ml) compared with 6 to 12 cm (median, 11 ml; range, 0-124 ml) or higher than 12 cm (median 9 ml; range, 0 to 16 ml) from the anal margin, but the difference was not significant. Drainage after anterior resection is important because large volumes of serosanguineous fluid collect, especially after resection of low tumors. Neither of the drainage methods tested in this study prevented persisting pelvic fluid collection at the seventh postoperative day.

To evaluate the measurement of fluid status in the premature neonate using dynamic skinfold thickness (DST) measurement, a pair of calipers were interfaced to a computer, and weight and digital DST at four sites were measured daily in 24 neonates in the postnatal weight loss period. A biexponential equation was fitted to each curve from the instant the rate of caliper closure fell below 2 mm/s, and the five constants obtained used in a search for a parameter that correlated with the percentage of weight loss. The percentage of fall in the DST from 0.4 to 30 seconds yielded highest mean of individual coefficients of determination (COD) (0.83); the percentage of fall from 0.7 to 35 seconds yielded highest COD in pooled data (0.56). Expected weight loss can be predicted with standard error of 2.9% with pooled regression but with standard error of 1.3% using individual correlations. We conclude that individuals lose fluid in a consistent manner during this period but that interindividual differences are large and require further investigation.

Most bezoars are composed of hair (trichobezoars) or fibrous food debris (phytobezoars). The great majority are found in the stomach. DeBakey and Ochsner (1938, 1939) list 303 bezoars from the world literature and report another eight cases. Their total of 311 includes 172 trichobezoars, 126 phytobezoars and 13 bezoars of other concretions with only a single case of bezoar confined to the oesophagus. Various individual reports of oesophageal bezoar published since include nine cases of bezoar and two of food impaction (Pelner & Levy 1960; Mersten et al, 1981). They include six males and four females, with ages ranging from 27 to 78. We report an example of an intrathoracic phytobezoar causing acute gastro-oesophageal symptoms. A 50-year-old woman was admitted in 1980 with a threeweek history of vomiting, epigastric pain and weight loss. In 1971 she had undergone surgery for hiatus hernia. She had presented at another hospital in 1977 with epigastric pain and vomiting, when a barium meal had demonstrated w...

Results from a continuing clinical trial in benign breast disease indicate that danazol may induce progesterone receptors and that this effect persists after treatment. In women given danazol the number of biopsy specimens that were positive for progesterone receptors rose from 14 out of 31 before treatment to 23 out of 30 at the end of six months' treatment and remained raised at 21 out of 31 six months later. The number of biopsy specimens that were positive for oestrogen receptors rose transiently from eight out of 31 to 12 out of 30 and then fell to six out of 31. A satisfactory clinical response was achieved in 26 of the 31 patients but was maintained in only 11 six months or more after the end of treatment. It was only in this group that a significant and long-standing increase in progesterone receptors was observed. These findings suggest that in some women with benign breast disease who have been treated with danazol changes occur that may have long term benefit.

The inferior vena cava (i.v.c.) is a collapsible vessel which is subject to respiratory pressure variations. Clinical observations on humans show that, during deep inspiration, an increase in the propulsive pressure gradient causes the i.v.c. to collapse near the diaphragm and paradoxically reduces the blood flow. Postmortem casts show that there is a sharply localised elastic constriction where the i.v.c. passes through the diaphragm. A passive mechanical model, incorporating a similar elastic constriction, exhibits similar paradoxical or negative-resistance behaviour, which is in accordance with the principles governing flow through collapsible tubes.