St Thomas' Hospital

About: St Thomas' Hospital is a healthcare organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Pregnancy. The organization has 12105 authors who have published 15596 publications receiving 624309 citations. The organization is also known as: St Thomas's Hospital & St. Thomas's.

Anaesthesia for Caesarean section and neonatal acid‐base status: a meta‐analysis*

Abstract: Spinal anaesthesia is generally preferred for Caesarean section. Its superiority for the baby is often assumed. Umbilical artery acid-base status provides a valid index of fetal welfare. Twenty-seven studies reporting neonatal acid-base data with different types of anaesthesia were used to compare umbilical artery or vein pH and base deficit, using random-effect meta-analysis. Cord pH was significantly lower with spinal than with both general (difference: -0.015; 95% CI -0.029 to -0.001; 13 studies, 1272 subjects) and epidural anaesthesia (difference -0.013; 95% CI -0.024 to -0.002; 11 studies, 828 subjects). Larger doses of ephedrine contributed to the latter effect (p = 0.023). Sixteen studies reported a base deficit, which was significantly higher for spinal than for general (difference 1.109; 95% CI 0.434-1.784 mEq.l(-1); seven studies, 695 subject) and epidural anaesthesia (difference 0.910; 95% CI 0.222-1.598 mEq.l(-1); seven studies, 497 subjects). Spinal anaesthesia cannot be considered safer than epidural or general anaesthesia for the fetus.

Bisphosphonate-Anchored PEGylation and Radiolabeling of Superparamagnetic Iron Oxide: Long-Circulating Nanoparticles for in Vivo Multimodal (T1 MRI-SPECT) Imaging

Abstract: The efficient delivery of nanomaterials to specific targets for in vivo biomedical imaging is hindered by rapid sequestration by the reticuloendothelial system (RES) and consequent short circulation times. To overcome these two problems, we have prepared a new stealth PEG polymer conjugate containing a terminal 1,1-bisphosphonate (BP) group for strong and stable binding to the surface of ultrasmall-superparamagnetic oxide nanomaterials (USPIOs). This polymer, PEG(5)-BP, can be used to exchange the hydrophobic surfactants commonly used in the synthesis of USPIOs very efficiently and at room temperature using a simple method in 1 h. The resulting nanoparticles, PEG(5)-BP-USPIOs are stable in water or saline for at least 7 months and display a near-zero ζ-potential at neutral pH. The longitudinal (r1) and transverse (r2) relaxivities were measured at a clinically relevant magnetic field (3 T), revealing a high r1 of 9.5 mM–1 s–1 and low r2/r1 ratio of 2.97, making these USPIOs attractive as T1-weighted MRI c...

A systematic review of the effect of oral antioxidants on male infertility

Abstract: The use of antioxidants in treatment of infertile men has been suggested, although the evidence base for this practice is unclear. A systematic review of randomized studies was conducted to evaluate the effects of oral antioxidants (vitamins C and E, zinc, selenium, folate, carnitine and carotenoids) on sperm quality and pregnancy rate in infertile men. MEDLINE, EMBASE, Cochrane Library and CINAHL were searched for relevant trials published from respective database inception dates to May 2009. Study selection, quality appraisal and data extraction were performed independently and in duplicate. Seventeen randomized trials, including a total of 1665 men, were identified, which differed in the populations studied and type, dosage and duration of antioxidants used. Only two-thirds of the studies (11/17) reported using allocation concealment and three studies (18%) used intention-to-treat analysis. Despite the methodological and clinical heterogeneity, 14 of the 17 (82%) trials showed an improvement in either sperm quality or pregnancy rate after antioxidant therapy. Ten trials examined pregnancy rate and six showed a significant improvement after antioxidant therapy. The use of oral antioxidants in infertile men could improve sperm quality and pregnancy rates. Adequately powered robust trials of individual and combinations of antioxidants are needed to guide clinical practice.

A survey of the acoustic output of commercial extracorporeal shock wave lithotripters

Abstract: A survey of the pressures and intensities generated by different commercial extracorporeal shock wave (ESWL) lithotripters is reported. The lithotripters included in the survey are the Dornier HM3, Wolf Piezolith 2200 and 2300, Siemens Lithostar, Technomed Sonolith 2000 and 3000, and EDAP LT-01. Measurements were made using a polyvinylidene difluoride (PVdF) membrane hydrophone in water. The zero crossing frequency of one complete cycle of the focused pulse from ESWL equipment is in the range 0.1 to 1 MHz. Spatial-peak temporal-peak positive and negative pressures up to 114 MPa and 10 MPa, respectively, have been measured and the rise times of the positive pressure half cycle at maximum output settings are 30 ns or less. The mean spatial-peak temporal-average intensity of the lithotripters is 5.0 × 10 2 W m −2 when operated at a pulse repetition frequency of 1 Hz. The spatial-peak pulse-average intensity ranges from 6.6 × 10 7 to 1.24 × 10 9 W m −2 . The estimated acoustic energy in a single pulse (at the focus) at the maximum output setting of the lithotripters varies from 2.0 × 10 −3 J to about 9.0 × 10 −2 J. The beam area in the focal plane varies by a factor of 100 on different lithotripters and the temporal-peak pressure at the position of the skin at the entry point of the beam by a factor of 30. Measurement problems associated with hydrophone damage and the uncertainties in the hydrophone calibration at high pressures are discussed and an estimate of the total uncertainty in the absolute measurements of the spatial-peak temporal-peak positive pressure is given as ±36%.