Pseudoprominent aorta: radiographic findings and CT correlation

The presence of a persistent left-sided superior vena cava (LSVC) in the absence of a right-sided superior vena cava (RSVC) may be suspected on a posteroanterior (PA) chest radiograph because of a prominent-appearing ascending aorta, which results from the absence of the RSVC. In the absence of an RSVC, the right upper lobe abuts and outlines the course of the ascending aorta, allowing better demonstration of its profile. This report describes a patient with this finding on a PA chest radiograph. Computed tomographic correlation is presented.     

Doppler ultrasonography of the fetoplacental circulation--normal reference values

Normal reference values for the resistance index, A/B ratio and pulsatility index of the umbilical artery obtained by Doppler ultrasonography are presented. The resistance index and A/B ratio values are very similar to those previously published, indicating no need to formulate normal values for different populations. The pulsatility index differed from other published values, probably reflecting different calculation methods built into the spectrum analysers rather than differences in waveforms. The resistance index had the lowest coefficient of variation and showed least inter-observer variation. For routine use the resistance index is preferable to other indices.     

Conservative management of severe proteinuric hypertension before 28 weeks' gestation

Forty-five patients with severe proteinuric hypertension who presented before 28 weeks' gestation were managed conservatively by bed rest, antihypertensive treatment, betamethasone administration after 26 weeks' gestation, and intensive fetal and maternal monitoring. Eleven patients presented before 24 weeks and their babies all died; 34 patients presented at or after 24 weeks and 13 of their babies survived (38%). The indications for delivery were intra-uterine death (13), fetal distress (9), deterioration in the mother's condition (17), and maternal complications--pulmonary oedema in 3 cases and pleural effusion in 1. One patient went into spontaneous labour and one was induced at 34 weeks. At postpartum follow-up examination all the mothers in the group that had presented before 24 weeks were found to have underlying diseases, compared with 42% of those who had presented between 24 and 27 weeks. The low incidence of maternal complications and the relatively good survival rate of 38% indicate that there is a place for conservative management in patients with severe proteinuric hypertension presenting at 24 weeks or later. Termination of the pregnancy should, however, be seriously considered in those patients presenting before 24 weeks' gestation.     

Distribution of biliary cholesterol between mixed micelles and nonmicelles in relation to fasting and feeding in humans

To further investigate the nonmicelle mode of cholesterol transport in human bile, we examined its levels in relation to fasting and feeding. T-tube bile samples were collected (for 30 min) every 4 h over a 24-h period. All patients (3 with cholesterol gallstones; 1 with pigment stone) had their T tube clamped for a minimum of 4 days before the study to allow the bile acid pool to replete. Biliary lipid concentrations in all patients increased with feeding and decreased with fasting. However, because of a greater decrease in bile acid concentration relative to cholesterol concentration during the fasting period, fasting bile was consistently more saturated than bile obtained while feeding. Associated with the increase in lithogenic index with fasting was a decrease in the micelle solubilized cholesterol and an increase in nonmicelle solubilized cholesterol. At low bile acid concentrations (fasting) most biliary cholesterol is therefore transported as a nonmicelle complex, whereas at high bile acid concentrations (feeding) most of the cholesterol is transported in the mixed micelle. No nucleation of the biliary samples was observed in any of the patients over a 10-day period of observation. Thus the biliary nonmicelle complex (presumably vesicles) has a major cholesterol transport function especially at low bile acid concentrations.     

Effect of sildenafil and acclimatization on cerebral oxygenation at altitude

Phosphodiesterase-5 inhibitors decrease hypoxic pulmonary vasoconstriction under hypobaric hypoxia, but are not known to affect cerebral blood flow or oxygenation. The present study was designed to evaluate the effect of sildenafil on cerebral haemodynamics during acute exposure to altitude and after acclimatization. Ten subjects were studied 1 and 3 days after rapid ascent to 3480 m before and for two consecutive hours after taking sildenafil (50 mg). Before acclimatization, HR (heart rate) rose at 1 h (76.3+/-1.0 beats/min compared with 72.5+/-1.5 beats/min at baseline; P<0.05) and had returned to baseline at 2 h (71.3+/-1.1 beats/min; P>0.05). Mean BP (blood pressure) fell from 96.0+/-2.0 mmHg at baseline to 91.7+/-2.5 (P<0.001) at 1 h and 89.8+/-1.8 mmHg (P<0.0001) at 2 h, whereas SaO2 (arterial oxygen saturation) increased from 83.9+/-0.5% at baseline to 85.3+/-0.4% (P<0.0001) at 1 h and 85.0+/-0.5% (P<0.01) at 2 h. MCAV [MCA (middle cerebral artery) velocity] and PETCO2 (end-tidal partial pressure of CO2) were unchanged, but rSO2 (regional cerebral oxygen saturation) rose progressively at 1 h (62.7+/-0.8%; P<0.05) and 2 h (65.3+/-0.9%; P<0.0001) compared with baseline (59.3+/-1.3%). After 3 days of acclimatization, resting rSO2 and RMCA (MCA resistance) increased and oxygen delivery fell. Changes in HR and mean BP after sildenafil were similar to day 1, but SaO2 did not change. However, rSO2 increased [61.7+/-0.9% at baseline to 65.0+/-1.0% (P<0.0001) at 1 h and 64.0+/-0.9% (P<0.001) at 2 h], despite a reduction in MCAV [65.3+/-1.8 cm/s at baseline to 61.3+/-1.5 cm/s (P<0.01) at 1 h and 60.9+/-1.7 cm/s (P<0.0001) at 2 h] and PETCO2 [4.1+/-0.05 kPa at baseline to 4.0+/-0.04 kPa at 2 h (P<0.01)]. These observations suggest that sildenafil improves cerebral oxygenation at altitude. Whereas the early changes before acclimatization may be largely pulmonary in origin, the later observations may be a direct cerebral effect which warrants further study.     

Evaluation of a non-invasive method of assessing opioid induced respiratory depression

Opioid induced respiratory depression is potentially fatal. The aim of this study was to validate a monitoring system that could be used to assess respiratory depression in postoperative patients. The hypercapnic ventilatory response was estimated non-invasively in 12 volunteers. In two steps, we tested a system which delivered carbon dioxide (CO(2)) challenges through a venturi mask, measuring changes in ventilation with an uncalibrated respiratory inductance plethysmograph (RIP). RIP and pneumotachograph measurements of ventilation, taken at the same time during a CO(2) challenge, were similar; group mean (SD), pneumotachograph 13.9 (3.5) l x min(-1) x kPa(-1), RIP 14.3 (2.9) l x min(-1) x kPa(-1). Bland-Altmann analysis showed the variation between these two methods was +/- 5 l x min(-1) x kPa(-1) (2 SD). Second, we confirmed that the venturi mask is suitable for delivering CO(2) challenges. Despite the variability in RIP measurements, a simple multimodal respiratory monitoring system could be developed that incorporates clinical observation and non-invasive measurement of the ventilatory response to CO(2).     

The effect of dietary vitamin E and fatty acid supplementation of pregnant and lactating ewes on placental and mammary transfer of vitamin E to the lamb

The present study investigated the effect of maternal vitamin E and fatty acid supplementation on lamb antioxidant status. Forty-eight ewes were fed one of four concentrate diets supplemented with a basal (50 mg/kg) or supranutritional (500 mg/kg) level of vitamin E plus a source of either saturated fat (Megalac; Volac Ltd, Royston, Hertfordshire, UK) or long-chain PUFA (fish oil) from 6 weeks prepartum until 4 weeks postpartum. Blood samples were taken from ewes and lambs at intervals throughout the experiment and, at parturition, muscle, brain and blood samples were obtained from twelve lambs (three per treatment). Colostrum and milk samples were obtained at 12 h and 21 d after parturition, respectively. Supranutritional vitamin E supplementation of the ewe significantly increased concentrations of vitamin E in neonatal lamb tissues although plasma concentrations were undetectable. A significant increase in lamb birth weight resulted from increasing the dietary vitamin E supply to the ewe. Furthermore, maternal plasma, colostrum and milk vitamin E concentrations were increased by vitamin E supplementation, as were lamb plasma concentrations at 14 d of age. Neonatal vitamin E status was not significantly affected by fat source although plasma vitamin E concentrations in both ewes and suckling lambs were reduced by fish oil supplementation of the ewe. Fish oil supplementation reduced vitamin E concentrations in colostrum and milk and the activity of glutathione peroxidase in suckling lambs. The data suggest that the vitamin E status of the neonatal and suckling lamb may be manipulated by vitamin E supplementation of the ewe during pregnancy and lactation.     

Live births after autologous transplant of cryopreserved mouse ovaries

The fertility of mice after autologous transplantation of ovaries, before or after cryopreservation, was investigated in this study. Female mice were randomly assigned to either sham-operated (n = 14), ovariectomized (n = 11), fresh (n = 12) or cryopreserved (n = 11) ovarian transplant groups. Ovaries were cryopreserved in 1.4 M dimethyl sulphoxide (DMSO) by cooling to -55 degrees C at 0.5 degree C/min (ice nucleation at -7 degrees C), plunged in liquid nitrogen and then thawed at room temperature. Oestrous cyclicity was observed 7 days after sham operation or 15 days after fresh or cryopreserved ovarian transplant. Ovariectomized animals did not demonstrate oestrous cyclicity but were mated, and no pregnancies resulted. Live births were recorded from all sham-operated, all fresh transplant, and 8/11 (73%) cryopreserved transplant animals. Overall mean +/- SEM litter sizes from fresh (4.32 +/- 0.44) and cryopreserved (4.71 +/- 0.57) transplant groups were smaller (P < 0.05) than those of sham-operated animals (12.54 +/- 0.44), although the sizes were not significantly different (P > 0.05) from each other. Animals were mated at least four times, with four litters of live pups from 4/4 sham-operated, 1/10 fresh and 1/9 cryopreserved ovarian transplant animals. Litter sizes from pups of sham-operated and transplant animals were not significantly different from each other. Following autologous transplantation of mouse ovaries, before or after cryopreservation, offspring appeared normal, with high rates of fertility.      

Hepaticocystic duct — A case report

Summary A case of an anomalous extrahepatic biliary system is reported in which the common hepatic duct was found to enter the gallbladder, whereas the cystic duct drained the entire biliary system into the duodenum. In this case, the gangrenous gallbladder was removed and the continuity between the common hepatic duct and the gastrointestinal tract was restored by means of Roux-en-Y anastomosis. The identification and treatment options of this rare anomaly are briefly discussed.

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Conduit hépatico-cystique. A propos d'un cas

Résumé Un cas d'anomalie du système biliaire extra-hépatique est rapporté, dans lequel le conduit hépatique commun pénétrait la vésicule biliaire, tandis que le conduit cystique drainait la totalité du système biliaire dans le duodénum. Dans ce cas, la vésicule gangreneuse était enlevée et la continuité entre le conduit hépatique commun et le tractus digestif était restauré par une anastomose sur anse en Y de Roux. L'identification et les options thérapeutiques de cette anomalie rare sont brièvement discutées.