Sterile water injection for labour pain: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Up to one-third of labouring women will experience painful 'back labour'. Sterile water injected lateral to the lumbosacral spine is a simple and well-researched approach to this pain. OBJECTIVE: To determine if sterile water injection for low back pain compared to placebo or alternative therapy increased or decreased the rate of Caesarean section. SEARCH STRATEGY: We performed a literature search with no language restriction in four databases: the Cochrane library, EMBASE (1980-2009), Ovid Medline (1950-2009) and CINAHL (1982-2009). SELECTION CRITERIA: We included all randomised controlled trials (RCTs) of sterile water injection for labour pain that included outcomes of interest and original data. DATA COLLECTION AND ANALYSIS: We compared Caesarean section rates among women who received sterile water injection in labour with those who received either placebo treatment or another non-pharmacological treatment modality. Other outcomes included pain scores, use of regional analgesia and women's assessment of treatment. We used Revman 5 for the meta-analysis. Data were entered by one reviewer and independently cross-checked. Pooled outcomes were reported as Relative Risk (RR) or Weighted Mean Difference using Mantel-Haenszel fixed-effects model except when the I2 value >50% indicated significant heterogeneity in which case random-effects model was used. MAIN RESULTS: We included eight RCTs. The Caesarean section rate was 4.6% in the sterile water injection group and 9.9% in the comparison group (n = 828) (RR 0.51, 95% CI: 0.30, 0.87). CONCLUSION: We believe that a large RCT should be mounted to validate our findings regarding the impact of sterile water injections on mode of delivery.

Radiation sources based on laser-plasma interactions.

Plasma waves excited by intense laser beams can be harnessed to produce femtosecond duration bunches of electrons with relativistic energies. The very large electrostatic forces of plasma density wakes trailing behind an intense laser pulse provide field potentials capable of accelerating charged particles to high energies over very short distances, as high as 1GeV in a few millimetres. The short length scale of plasma waves provides a means of developing very compact high-energy accelerators, which could form the basis of compact next-generation light sources with unique properties. Tuneable X-ray radiation and particle pulses with durations of the order of or less than 5fs should be possible and would be useful for probing matter on unprecedented time and spatial scales. If developed to fruition this revolutionary technology could reduce the size and cost of light sources by three orders of magnitude and, therefore, provide powerful new tools to a large scientific community. We will discuss how a laser-driven plasma wakefield accelerator can be used to produce radiation with unique characteristics over a very large spectral range.

Efficiency and energy spread in laser-wakefield acceleration.

The theoretical limits on efficiency and energy spread of the laser-wakefield accelerator are investigated using a one-dimensional model. Modifications, both of the wakefield due to the electron bunch, and of the laser pulse shape due to the varying permittivity of the plasma, are described self-consistently. It is found that a short laser pulse gives a higher efficiency than a long laser pulse with the same initial energy. Energy spread can be minimized by optimizing bunch length and bunch charge such that the variation of the accelerating force along the length of the bunch is minimized. An inherent trade-off between energy spread and efficiency exists.

Bunch self-focusing regime of laser wakefield acceleration with reduced emittance growth.

A new regime of laser wakefield acceleration of an injected electron bunch is described. In this regime, the bunch charge is so high that the bunch wakefields play an important role in the bunch dynamics. In particular, the transverse bunch wakefield induces a strong self-focusing that suppresses the transverse emittance growth arising from misalignment errors. The decelerating longitudinal bunch wakefield, however, is not so strong that it completely cancels the accelerating laser wakefield. In fact, the induced energy spread can be compensated by exploiting phase slippage effects. These features make the new regime interesting for high beam quality laser wakefield acceleration.

Simulation of laser wakefield acceleration of an ultrashort electron bunch.

The dynamics of the acceleration of a short electron bunch in a strong plasma wave excited by a laser pulse in a plasma channel is studied both analytically and numerically in slab geometry. In our simulations, a fully nonlinear, relativistic hydrodynamic description for the plasma wave is combined with particle-in-cell methods for the description of the bunch. Collective self-interactions within the bunch are fully taken into account. The existence of adiabatic invariants of motion is shown to have important implications for the final beam quality. Similar to the one-dimensional case, the natural evolution of the bunch is shown to lead, under proper initial conditions, to a minimum in the relative energy spread.

In vitro and in vivo microbial adhesion and growth on argon plasma-treated silicone rubber voice prostheses.

Patients who undergo a total laryngectomy usually receive a silicone rubber voice prosthesis for voice rehabilitation. Unfortunately, biofilm formation on the esophageal side of voice prostheses limits their lifetime to 3-4 mon on average. The effects of repeated argon plasma treatment of medical grade, hydrophobic silicone rubber on in vitro adhesion and growth of bacteria and yeasts isolated from voice prostheses, as well as in vivo biofilm formation are presented here. In vitro experiments demonstrated that initial microbial adhesion over a 4 h time span to plasma-treated, hydrophilized, silicone rubber was generally less than on original, hydrophobic silicone rubber, both in the absence and presence of a salivary conditioning film on the biomaterial. Growth studies over a time period of 14 d at 37 degrees C in a modified Robbins device, showed that fewer Candida cells adhered on plasma-treated, hydrophilized silicone rubber as compared to on original, hydrophobic silicone rubber. For the in vivo evaluation of biofilm formation on plasma-treated silicone rubber voice prostheses, seven laryngectomized patients received a partly hydrophilized "Groningen Button" voice prosthesis for a planned evaluation period of 4 wk. After removal of the voice prostheses, the border between the hydrophilized and the original, hydrophobic side of the prostheses was clearly visible. However, biofilm formation was, unexpectedly, less on the original, hydrophobic sides, although the microbial compositions of the biofilms on both sides were not significantly different. Summarizing, this study demonstrates that in vitro microbial adhesion and growth on silicone rubber can be reduced by plasma treatment, but in vivo biofilm formation on silicone rubber voice prostheses is oppositely enhanced by hydrophilizing the silicone rubber surface. Nevertheless, from the results of this study the important conclusion can be drawn that in vivo biofilm formation on voice prostheses is controlled by the hydrophobicity of the biomaterials surface used.

Sensitization to azo dyes: negative patch tests to yellow and red azo dyes in printed paper.

An over 2 x fold increase in para-aminoazobenzene allergy was observed in patients with allergic contact dermatitis during the years 1990-1991. Presuming that an increase in colour-printed newspapers might be a new unrecognized source of clinical allergy to azo dyes, patch tests were performed in 32 patients with an established p-aminoazobenzene allergy using a series of important azo dyes used in offset printing ink (Pigment Yellow 12, Pigment Yellow 13, Pigment Red 53, Pigment Red 57), as well as with dye-containing inks and specimens of colour-printed newspaper containing these azo dyes. In 25 out of the 32 patients (78%), positive patch tests were seen to textile azo dyes, in particular to Disperse Orange 3 (24 patients). In none of the 32 patients were reactions observed to the azo dyes used in printing ink, to the inks used or to the colour-printed paper specimens, indicating that these products were apparently not a cause of contact dermatitis in our group of patients with azo dye sensitization.

Sensitization to fragrance materials in Indonesian cosmetics.

2 different groups of patients were patch tested with 2 test series (A and B) containing extracts of fragrance raw materials, traditionally used in Indonesian cosmetics. Series A consisted of diluted extracts of commercially available Indonesian fragrances. Series B consisted of extracts prepared in our department from corresponding indigenous flowers and fruits. Group 1 consisted of 32 patients positive to fragrance-mix, of whom 8 (25%) had positive tests to 1 or more of the different extracts of fragrance raw materials. Reactions were observed to extracts of: Rosa hybrida Hort (7); Canangium odoratum Baill (5); Citrus aurantifolia Swingle (4); Jasminum sambac Ait (2). 6 of the 8 patients had reactions to 1 or more of the components of fragrance-mix: oakmoss (3); cinnamic alcohol (2), isoeugenol (1); cinnamic aldehyde (1) and geraniol (1). Group 2 consisted of 159 patients patch tested on suspicion of contact dermatitis, who were fragrance-mix negative. Only 2 (1.2%) had a positive patch test to the extracts of fragrance raw materials. Specimens taken (as is) from the flowers and citrus fruits (being the basis sources of the fragrance raw materials) were less antigenic. The use of additional test series in Indonesia to detect allergy to traditional cosmetics and perfumes merits further investigation.

Effects of topically applied glucocorticosteroids on patch test responses and recruitment of inflammatory cells in allergic contact dermatitis.

The effects of repeated topical application of a strong glucocorticosteroid (GCS) on patch test responses and the inflammatory infiltrate were studied in twenty nickel allergic patients. Patch test responses were strongly inhibited in 18 out of 20 patients. Immunohistochemical analysis revealed marked reductions in CD1+(T6+) Langerhans cells, activated inflammatory T cells and of mast cells in the skin. It is concluded that GCS suppress contact allergic responses by reduction, or functional inhibition of antigen presenting cells. The reduced number of mast cells release less vasoactive mediators, inhibiting recruitment of inflammatory cells.

Allergy to spermicidal lubricant in a contraceptive.

PIP: Allergic contact dermatitis is reported in a patient using a condom with the spermicidal lubricant Tectol. A 36 year old female, with no history of dermatitis or pruritus of the vagina or vulva, experienced itchy dermatitis 24-48 hours after her partner used a Durex Top Safe contraceptive containing Tectol. The dermatitis appeared on the neck, upper legs, underarms, and trunk area. When another contraceptive was used Durex Featherlite (without Tectol), the patient experienced no problems. Patch tests concluded that the Tectol lubricant was the cause for the reaction in the patient. Transmission of the lubricant to the patient occurred when the patient's partner, after handling the contraceptive (Durex Top Safe) during intercourse, placed his hands on the patient's body. To which exact element of Tectol the patient was sensitized could not be determined as the patient refused further treatment.^ieng

Sensitization to sodium hypochlorite causing hand dermatitis.

2 patients are reported with chronic hand dermatitis related to sensitization to sodium hypochlorite, as the active component in a bleaching product. To avoid irritant reactions in patch testing, a sodium hypochlorite concentration of 1.0% appeared to be useful. It is concluded that with regard to the frequent use of bleaching agents, allergy to sodium hypochlorite must be considered in certain cases of unidentified chronic allergic hand dermatitis.