Improved skin decontamination efficacy for the nerve agent VX.

Early initiated decontamination is demonstrated to be crucial to avoid systemic effects of highly toxic and low volatile agents exposed on the skin. Skin decontamination can be performed by simple procedures, such as washing with soap and water, or by using advanced decontamination products containing absorption and agent degradation properties. Reactive Skin Decontamination Lotion (RSDL) has demonstrated high efficacy to remove nerve agents from the skin. However, contrary to the current operational recommendations, experimental studies have shown that prolonged skin contact time of RSDL is important for efficient decontamination of VX. In the present study, several RSDL-protocols were evaluated for the efficacy to remove neat VX from human skin in vitro. The decontamination efficacies of the RSDL-procedures were compared with the efficacy of the simple procedure of washing off the skin with soapy water. The RSDL-protocols containing repeated swabbing with the sponge and a 10 min skin contact time of RSDL-lotion demonstrated the greatest decontamination efficacy of all procedures evaluated. Repeating the protocol 2 h after the initial decontamination step resulted in a transient increased skin penetration of remaining intact agent on skin and was followed by rapidly declined agent penetration rate. Decontamination performed with soapy water significantly increased agent amounts penetrating skin, most likely caused by skin hydration and agent dilution. In conclusion, a slightly extended procedure for RSDL-decontamination showed improved efficacy and is therefore recommended for removal of nerve agents from the skin. In addition, it is of highest importance that skin decontamination of nerve agents should consist of procedures using low water content.

Comparison of skin decontamination efficacy of commercial decontamination products following exposure to VX on human skin.

The decontamination efficacy of four commercially available skin decontamination products following exposure to the nerve agent VX was evaluated in vitro utilizing a diffusion cell and dermatomed human skin. The products included were Reactive Skin Decontamination Lotion (RSDL), the Swedish decontamination powder 104 (PS104), the absorbent Fuller's Earth and the aqueous solution alldecontMED. In addition, various decontamination procedures were assessed to further investigate important mechanisms involved in the specific products, e.g. decontamination removal from skin, physical removal by sponge swabbing and activation of degradation mechanisms. The efficacy of each decontamination product was evaluated 5 or 30 min after dermal application of VX (neat or diluted to 20% in water). The RSDL-lotion was superior in reducing the penetration of VX through human skin, both when exposed as neat agent and when diluted to 20% in water. Swabbing with the RSDL-sponge during 2 min revealed decreased efficacy compared to applying the RSDL-lotion directly on the skin for 30 min. Decontamination with Fuller's Earth and alldecontMED significantly reduced the penetration of neat concentration of VX through human skin. PS104-powder was insufficient for decontamination of VX at both time-points, independently of the skin contact time of PS104. The PS104-slurry (a mixture of PS104-powder and water), slightly improved the decontamination efficacy. Comparing the time-points for initiated decontamination revealed less penetrated VX for RSDL and Fuller's Earth when decontamination was initiated after 5 min compared to 30 min post-exposure, while alldecontMED displayed similar efficacy at both time-points. Decontamination by washing with water only resulted in a significant reduction of penetrated VX when washing was performed 5 min after exposure, but not when decontamination was delayed to 30 min post-exposure of neat VX. In conclusion, early initiated decontamination with the RSDL-lotion, containing both absorption and degrading properties, allowed to act on skin for 30 min was superior in preventing VX from penetrating human skin. Adding water during decontamination resulted in increased penetration of neat VX, however, water in the decontaminant removal process did not influence the decontamination efficacy. From our study on commercially available decontaminants, it is recommended that future product developments should include both strong absorbents and efficient nerve agent degrading components.

RSDL decontamination of human skin contaminated with the nerve agent VX.

Dermal exposure to low volatile organophosphorus compounds (OPC) may lead to penetration through the skin and uptake in the blood circulation. Skin decontamination of toxic OPCs, such as pesticides and chemical warfare nerve agents, might therefore be crucial for mitigating the systemic toxicity following dermal exposure. Reactive skin decontamination lotion (RSDL) has been shown to reduce toxic effects in animals dermally exposed to the nerve agent VX. In the present study, an in vitro flow-through diffusion cell was utilized to evaluate the efficacy of RSDL for decontamination of VX exposed to human epidermis. In particular, the impact of timing in the initiation of decontamination and agent dilution in water was studied. The impact of the lipophilic properties of VX in the RSDL decontamination was additionally addressed by comparing chemical degradation in RSDL and decontamination efficacy between the VX and the hydrophilic OPC triethyl phosphonoacetate (TEPA). The epidermal membrane was exposed to 20, 75 or 90% OPC diluted in deionized water and the decontamination was initiated 5, 10, 30, 60 or 120min post-exposure. Early decontamination of VX with RSDL, initiated 5-10min after skin exposure, was very effective. Delayed decontamination initiated 30-60min post-exposure was less effective but still the amount of penetrated agent was significantly reduced, while further delayed start of decontamination to 120min resulted in very low efficacy. Comparing RSDL decontamination of VX with that of TEPA showed that the decontamination efficacy at high agent concentrations was higher for VX. The degradation mechanism of VX and TEPA during decontamination was dissected by 31P NMR spectroscopy of the OPCs following reactions with RSDL and its three nucleophile components. The degradation rate was clearly associated with the high pH of the specific solution investigated; i.e. increased pH resulted in a more rapid degradation. In addition, the solubility of the OPC in RSDL also influenced the degradation rate since the degradation of VX was significantly faster when the NMR analysis was performed in the organic solvent acetonitrile compared to water. In conclusion, we have applied the in vitro flow-through diffusion cell for evaluation of skin decontamination procedures of human epidermis exposed to OPCs. It was demonstrated that early decontamination is crucial for efficient mitigation of epidermal penetration of VX and that almost complete removal of the nerve agent from the skin surface is possible. Our data also indicate that the pH of RSDL together with the solubility of OPC in RSDL are of primary importance for the decontamination efficacy.

In vitro human skin penetration model for organophosphorus compounds with different physicochemical properties.

A flow-through diffusion cell was validated for in vitro human epidermal penetration studies of organophosphorus compounds (OPCs) applied by infinite dosing. By testing OPCs with similar molecular weight but different physicochemical properties, it was shown that hydrophilic and lipophilic properties are major determinants for the penetration rate. Lipophilic OPCs displayed maximum cumulative penetration in the 20-75% agent concentration range whereas the hydrophilic OPCs displayed maximum cumulative penetration at 10 or 20% agent concentration. Low penetration was observed for all agents at 1% agent concentration or when applied as neat agents. The impact of the receptor solution composition was evaluated by comparing the penetration using receptor solutions of different ratios of ethanol and water. For diluted OPCs, a high concentration of ethanol in the receptor solution significantly increased the penetration compared to lower concentrations. When OPCs were applied as neat agents, the composition of the receptor solution only affected the penetration for one of four tested compounds. In conclusion, the flow-through diffusion cell was useful for examining the penetration of OPCs through the epidermal membrane. It was also demonstrated that the penetration rates of OPCs are strongly influenced by dilution in water and the receptor fluid composition.

Emission factors for gases and particle-bound substances produced by firing lead-free small-caliber ammunition.

Lead-free ammunition is becoming increasingly popular because of the environmental and human health issues associated with the use of leaded ammunition. However, there is a lack of data on the emissions produced by firing such ammunition. We report emission factors for toxic gases and particle-bound compounds produced by firing lead-free ammunition in a test chamber. Carbon monoxide, ammonia, and hydrogen cyanide levels within the chamber were analysed by Fourier transform infrared spectroscopy, while total suspended particles and respirable particles were determined gravimetrically. The metal content of the particulate emissions was determined and the associated organic compounds were characterized in detail using a method based on thermal desorption coupled to gas chromatography and mass spectrometry. The particulate matter (∼30 mg/round) consisted primarily of metals such as Cu, Zn, and Fe along with soot arising from incomplete combustion. Nitrogen-containing heterocyclic aromatic compounds such as carbazole, quinolone, and phenazine were responsible for some of the 25 most significant chromatographic peaks, together with PAHs, diphenylamine, and phthalates. Emission factors were determined for PAHs and oxygenated PAHs; the latter were less abundant in the gun smoke particles than in domestic dust and diesel combustion smoke. This may be due to the oxygen-deficient conditions that occur when the gun is fired. By using an electrical low pressure impactor, it was demonstrated that more than 90% of the particles produced immediately after firing the weapon had diameters of less than 30 nm, and so most of the gun smoke particles belonged to the nanoparticle regime.

Phenotypic biomonitoring using multivariate flow cytometric analysis of multi-stained microorganisms.

A new method for monitoring phenotypic profiles of pure cultures and complex microbial communities was evaluated. The approach was to stain microorganisms with a battery of fluorescent dyes prior to flow cytometry analysis (FCM) and to analyse the data using multivariate methods, including principal component analysis and partial least squares. The FCM method was quantitatively evaluated using different mixtures of pure cultures as well as microbial communities. The results showed that the method could quantitatively and reproducibly resolve both populations and communities of microorganisms with 5% abundance in a diverse microbial background. The feasibility of monitoring complex microbial communities over time during the biodegradation of naphthalene using the FCM method was demonstrated. The biodegradation of naphthalene occurred to differing extents in microcosms representing three different types of aromatic-contaminated groundwater and a sample of bio-basin water. The FCM method distinguished each of these four microbial communities. The phenotypic profiles were compared with genotypic profiles generated by random-amplified polymorphic DNA analysis. The genotypic profiles of the microbial communities described only the microbial composition, and not their functional change, whereas the phenotypic profiles seemed to contain information on both the composition and the functional change of the microorganisms. Furthermore, event analysis of the FCM data showed that microbial communities with initially differing compositions could converge towards a similar composition if they had a capacity for high levels of degradation, whereas microbial communities with similar initial compositions could diverge if they differed in biodegrading ability.

Structure of a Natural Microbial Community in a Nitroaromatic Contaminated Groundwater Is Altered during Biodegradation of Extrinsic, but Not Intrinsic Substrates.

A BSTRACTThis study demonstrates microbial community changes over time in a nitroaromatic-contaminated groundwater upon amendment with hydrocarbons previously unknown to the microbial community (extrinsic) and hydrocarbons previously known to the microbial community (intrinsic). Sealed flasks, shaken and incubated at 25 degrees C, containing contaminated groundwater and salts were amended twice with extrinsic hydrocarbons including phenol, benzoic acid, and naphthalene, and intrinsic hydrocarbons including 2,4-dinitrotoluene (2,4-DNT) and para-nitrotoluene ( p-NT). Microbial growth, biodegradation, and community structure changes measured by random amplified polymorphic DNA (RAPD) and quantitative PCR (qPCR) targeting catechol-2,3-dioxygenase (C23O) genes were monitored over time. All amended substrates were biodegraded after both substrate amendments except for 2,4-DNT, which was only partially degraded after the second amendment. Unique microbial communities were developed in flasks amended with phenol, benzoic acid, and naphthalene. However, in the flasks amended with intrinsic hydrocarbons the microbial community remained similar to the unamended control flasks. The relative amount of C23O genes detected by qPCR correlated with the biodegradation of phenol and naphthalene but not with 2,4-DNT. The results showed that a selection for microorganisms capable of catabolizing extrinsic hydrocarbons naturally and initially present in the nitroaromatic-contaminated groundwater occurred. However, growth-linked biodegradation of added intrinsic hydrocarbons was not selective.

Personal decontamination after exposure to stimulated liquid phase contaminants: functional assessment of a new unit.

OBJECTIVE: To evaluate the efficacy of a decontamination station following exposure of volunteers to liquids with physical characteristics comparable to sarin and mustard gas. DESIGN: Twenty-four volunteers participated in the experiment which was performed with all staff wearing personal protective equipment including respiratory protection. The clothes, skin, and hair of the volunteers were contaminated with the simulated liquid phase contaminants, ethyl lactate and methyl salicylate. Sulphur hexafluoride gas was used to confirm the ventilation efficacy. Decontamination followed guidelines using a two-stage procedure. In the first chamber, all volunteers received a 3-minute shower with water at 30 degrees C, and their clothes but not their respiratory masks were removed. In the second, they were twice washed thoroughly with soap and water. After decontamination, the volunteers entered a third chamber for first aid measures. RESULTS: The air concentration of sulphur hexafluoride was reduced by 1:10,000 between the first and the third chambers. Ethyl lactate and methyl salicylate were measured in low concentrations in the third chamber. The capacity was 16 volunteers per hour with two-thirds on stretchers. After self-decontamination of the staff, the concentration of ethyl lactate increased significantly in the third chamber, consistent with residual ethyl lactate adsorbed by their underwear. This observation revealed a deficiency in the guidelines for self-decontamination. CONCLUSION: The capacity of the decontamination unit was found to be 16 volunteers per hour. The ventilation system and guidelines of the decontamination unit were demonstrated to be effective under the conditions examined. The self-decontamination of the staff was not optimal.

Future of assisted reproductive technologies.

Within a decade, from the birth of Louise Brown in 1978, there has been tremendous advances in the field of assisted reproduction. These advances are the collective result of techniques known as Assisted Reproductive Technologies (ART). ART is defined as techniques in which the oocyte is handled in-vitro before replacement either as oocytes or embryos. The techniques in ART include in-vitro fertilisation and embryo replacement (IVF-ER), gamete intra-fallopian transfer (GIFT), tubal embryo (TET), donor oocytes and embryos, and freezing of embryos and oocytes. The most recent has been assisting fertilisation by micro-manipulation, including zonal procedures and micro-insemination, e.g. micro-insemination sperm transfer (MIST). There has also been many ethical issues in ART, and little advance in the "take home" baby rate. There is now major interest in co-culture of embryos with ampullary, endometrial and fibroblast mono-layers, to improve the quality of these embryos before their return into the mother. Because of the public's interest in ART, its usefulness has been "oversold". In time to come, ART may be limited to patients who really need it.

Simple office methods to predict ovulation: the clinical usefulness of a new urine luteinizing hormone kit compared to basal body temperature, cervical mucus and ultrasound.

A new urine luteinizing hormone (LH) kit, First Response (Tambrands Inc., Palmer, MA) was compared with basal body temperature (BBT), cervical mucus scoring and abdominal ultrasound follicular scanning in their ability to predict ovulation to within 2 days of the serum LH peak. BBT was kept daily. From day 10 daily ultrasound scanning and cervical mucus examination were performed and serum oestradiol, luteinizing hormone, follicular stimulating hormone and progesterone were assayed. First Response was significantly more accurate than BBT and cervical mucus when compared in their ability to predict ovulation to within 2 days of the LH peak (p less than 0.05). First Response pinpointed 93% (27/29) of the ovulatory cycles compared to 72% (18/25) and 61% (19/31) for BBT and cervical mucus respectively. It was better but not significantly so against abdominal ultrasound which predicted 77% (24/31). The implications of this finding and the value of the other simple office tests in clinical practice are discussed.

Reduced rate of postoperative infections in emergency cesarean section after two doses of cefuroxim perioperatively. A placebo-controlled study.

The rate of postoperative infections after cesarean section was studied in a prospective double-blind randomized study to compare cefuroxim with a placebo. Intravenous bolus injections were given at the beginning of, and 12h after the operation. Eighty patients received cefuroxim and 80 received placebo. Endometritis or wound infection, or both, was diagnosed in 2/80 (2.5%) patients receiving cefuroxim and in 23/80 (29%) patients receiving placebo. No side effects were demonstrated or reported by the patients. Thus, two bolus injections of 1.5 g of cefuroxim given perioperatively significantly reduced postoperative infectious morbidity after emergency cesarean section.

Contributions to reproductive medicine through in-vitro fertilization: a review.

In vitro fertilization (IVF) is now an accepted treatment procedure for subfertility. Its use has also contributed greatly to the understanding of our knowledge in reproductive medicine. This review looks at these contributions. In the female, IVF has made it possible to examine more closely ovarian physiology through the follicular micro-environment, follicular dominance and cohorts. In the male, the new sperm preparation technology has assisted the investigation of sperm parameters in-depth. A better understanding of human egg and sperm physiology, the fertilization process and pre-implantation phenomena has also contributed to better management of the infertile couple. Perhaps in the future, the pre-implantation embryo may be considered as a "patient".

Effect of a strict preoperative hygienic routine on the rate of infections following cesarean section.

The frequency of postoperative infections after cesarean section was studied during two periods. In the first period no strict preoperative hygienic routines were applied; 321 patients were delivered by cesarean section during this period. In the next period strict hygienic routines were introduced; this period included 337 patients. The infection rate was significantly reduced during the second period from 20% to 16%. This reduction was found among the elective operations, and among parturients who had been treated in the hospital for more than 24 h prior to delivery. The frequency of endometritis decreased significantly from the first to the second period, whereas no difference was found concerning wound infections. Significantly fewer patients contracted septicemia during the second period. Since all septicemia cases occurred in endometritis patients the results might indicate that not only the number of patients contracting infection but also the severity of the infections was reduced. No reduction of infections was found after emergency operations. Antibiotic prophylaxis might therefore be of value in this group of patients.

Risk factors in cesarean section infection.

Factors associated with risk of postoperative infection after cesarean section were studied in 321 patients not given antibiotic prophylaxis. Infections occurred in 56 (25%) of the 228 patients who were delivered by emergency cesarean section and in eight (9%) of the 93 patients who underwent elective surgery (P less than .01). These frequencies corresponded well with the infection rates reported after administration of antibiotics in other studies. Risk factors were: duration of operation more than one hour; blood loss more than 800 ml; presence of Staphylococcus aureus in the nares; signs of intrauterine infection before surgery; and failure of progress in labor. The results indicated that obstetric interventions had been performed more frequently in patients at risk of infection, rather than being the real cause of the infections. The importance of strict preoperative hygienic routine is discussed.