A randomized controlled study of human serum albumin and serum substitute supplement as protein supplements for IVF culture and the effect on live birth rates.

BACKGROUND: It has been speculated that the addition of proteins more complex than human serum albumin (HSA) to culture media may improve IVF outcomes. Whether the expense, labor and risk of adding additional human-derived protein to IVF media are warranted is a question unanswered. METHODS: In a randomized controlled trial with couples undergoing routine IVF or ICSI, 528 patients were assigned to one of two treatment groups. Embryos were cultured in either media supplemented with HSA as a solitary protein supplement or in media supplemented with HSA+serum substitute supplement (SSS) from the 2PN stage until the time of embryo transfer. Clinical end-points monitored included implantation (total 1151 embryos) and live birth rates (total 528 patients). RESULTS: The transfer of embryos cultured in HSA+SSS resulted in higher embryo implantation (289/571, 50.6% versus 254/580, 43.8%; difference 6.8% with 95% CI 1.0-12.7, P = 0.042) and live birth rates (167/266, 62.8% versus 142/262, 54.2%; difference 8.6% with 95% CI 0.1-17.3, P = 0.043) when compared with those of women whose embryos were cultured with HSA as the sole protein supplement. CONCLUSIONS: SSS added to commercial HSA-supplemented embryo culture media resulted in an overall increase in implantation and live birth rates. It remains uncertain whether the use of human-derived blood products in culture media and the requirement for ultra-rigorous quality control measures make these findings applicable to the average IVF laboratory. Protein enrichment of media may significantly improve the blastocyst implantation rate, creating opportunities to transfer single blastocysts without compromising the live birth rate. The study was registered at clinicaltrials.gov. NCT00708383.

A controlled randomized trial evaluating the effect of lowered incubator oxygen tension on live births in a predominantly blastocyst transfer program.

BACKGROUND: The potentially damaging effect of free O(2) radicals to cultured embryos may be reduced by adding scavengers to the culture media or by reducing the incubator O(2) levels. However, lowering the O(2) in the culture environment can be expensive, troublesome and may not be justifiable. The objective of this study was to evaluate the effect of lowered incubator O(2) tension on live birth rates in a predominately Day 5 embryo transfer program. METHODS: Two hundred and thirty first-cycle women undergoing routine IVF or ICSI with ejaculated sperm were randomized in a prospective clinical trial and stratified for patient age and physician. Embryos of patients were randomly assigned for culture in either a 21% O(2) (atmospheric) or 5% O(2) (reduced) environment. Clinical endpoints monitored were rates of implantation, clinical pregnancy, live birth and blastocyst cryopreservation. RESULTS: Embryos cultured in a 5% O(2) environment consistently resulted in higher rates of live birth implantation (106/247, 42.9% versus 82/267, 30.7%; difference of 12.2% with 95% confidence interval (CI) of 3.9-20.3, P = 0.005) and live births (66/115, 57.4% versus 49/115, 42.6%; difference of 14.8% with 95% CI of 1.9-27.0, P = 0.043) when compared with rates among women whose embryos were cultured in an atmospheric O(2) environment. CONCLUSIONS: The overall increase in live births demonstrated by this study indicates that the effort and expense to culture embryos in a low-O(2) environment is justified. The study was registered at clinicaltrials.gov. NCT00708487.

If you want to cure their asthma, ask about their job.

Occupational asthma is the most common occupational respiratory disorder and accounts for 15% of cases of adult asthma. A recent systematic review of evidence and management has clarified patient care for General Practitioners (GPs) who are key professionals in early diagnosis. Exposure to respirable agents in the work environment by means of dust, water aerosol or gases, causes an allergic sensitisation process in the respiratory tract. Initial rhinitis and night cough may progress to patterns of work-related wheezing from two weeks to six months after starting employment. The absence of symptoms while on holiday or sick leave suggests the diagnosis. Serial peak flow recordings show characteristic patterns. Smoking and atopy have a variable influence on whether a worker will develop the disease with exposure. Early identification and removal from exposure is essential for the worker since it improves prognosis. Other workers will be at risk, and occupational hygienists are required to measure and improve the working environment by means of ventilation and extraction of toxic fumes. Workplaces with workers who are at risk of occupational asthma, such as paint sprayers, food processors, welders and animal handlers, require health surveillance programmes for new and existing employees, as well as reinforcement of the more important primary safety measures of environmental monitoring and respiratory protection. All clinicians responsible for asthma management need to be aware of the potential for occupational asthma in new cases of adult asthma or unexplained worsening of pre-existing asthma. Specialist help is required to confirm the diagnosis, which has substantial legal and economic implications for the worker and their employer.

Virological surveillance of influenza-like illness in the community using PCR and serology.

BACKGROUND: Surveillance of winter respiratory viral illness has been carried out for nearly 30 years using a clinical diagnosis by general practitioners as part of the Scottish Sentinel General Practice (SSGP) network. Contemparaneous laboratory diagnosis has not been available previously. OBJECTIVES: To assess the proportion of influenza-like illness (ILI) attributable to influenza, respiratory syncytial virus (RSV) and picornavirus infection during the winter season. To compare the influenza PCR data with serology of paired blood samples. STUDY DESIGN: Combined nose and throat swabs, from patients with ILI attending 15 general practices across Scotland, were submitted to the laboratory in virus PCR sample solution (VPSS). The extracted nucleic acid was tested using a multiplex reverse-transcription polymerase chain reaction (RT-PCR) assay. Serological analysis was performed on paired serum samples using complement fixation assays. The rate of influenza virus positivity was compared with reports of ILI obtained from the SSGP network. RESULTS: Of 240 samples received at the laboratory, 132 (55%) were PCR positive for influenza A virus. There were nine (3.8%) picornavirus and three (1.2%) RSV PCR positives, two (0.8%) were dual influenza A/picornavirus infections. Ninety four (39.2%) were negative for all viruses tested. Results on paired sera from 89 patients showed a rising titre to influenza A in 48 of the 57 PCR positive samples (84.2%). One PCR negative patient displayed a significant rising titre to influenza A. Virological data paralleled the SSGP data but was available at least a week earlier. CONCLUSIONS: Influenza A infection was detected in the majority of patients with ILI; picornavirus infection was also shown to be an important cause of illness. PCR is a rapid and sensitive method for respiratory virus surveillance. Serology is slow, insensitive and difficult to interpret at low titres.

Facile synthesis of (Z)-tetracos-5-enoic acid and racemic cis-4-(2-octadecylcyclopropane-1-yl)-butanoic acid.

(Z)-tetracos-5-enoic acid and racemic cis-4-(2-octadecylcyclopropane-1-yl)-butanoic acid have been prepared from 1-eicosene by a new facile route. Periodic acid cleavage of the epoxide of 1-eicosene gave nonadecanal which was condensed with 4-carboxybutyltriphenylphosphonium bromide to give predominately (Z)-tetracos-5-enoic acid. Simmons-Smith type cyclopropanation of (Z)-tetracos-5-enoic acid gave a minor proportion of racemic cis-4-(2-octadecylcyclopropane-1-yl)-butanoic acid accompanied by major amounts of its methyl ester.

A type II pathway for fatty acid biosynthesis presents drug targets in Plasmodium falciparum.

It has long been held that the malaria parasite, Plasmodium sp., is incapable of de novo fatty acid synthesis. This view has recently been overturned with the emergence of data for the presence of a fatty acid biosynthetic pathway in the relict plastid of P. falciparum (known as the apicoplast). This pathway represents the type II pathway common to plant chloroplasts and bacteria but distinct from the type I pathway of animals including humans. Specific inhibitors of the type II pathway, thiolactomycin and triclosan, have been reported to target this Plasmodium pathway. Here we report further inhibitors of the plastid-based pathway that inhibit Plasmodium parasites. These include several analogues of thiolactomycin, two with sixfold-greater efficacy than thiolactomycin. We also report that parasites respond very rapidly to such inhibitors and that the greatest sensitivity is seen in ring-stage parasites. This study substantiates the importance of fatty acid synthesis for blood-stage parasite survival and shows that this pathway provides scope for the development of novel antimalarial drugs.

Analogues of thiolactomycin: potential drugs with enhanced anti-mycobacterial activity.

Analogues of the antibiotic thiolactomycin (TLM) have been synthesized and have been shown to have enhanced activity against whole cells of Mycobacterium tuberculosis H37Rv and against mycolic acid biosynthesis in cell extracts of Mycobacterium smegmatis. TLM has a methyl-branched butadienyl side chain attached at position 5 on a 'thiolactone' ring, namely 4-hydroxy-3,5-dimethyl-5H-thiophen-2-one. Various combinations of strong bases were explored to create a reactive anion at position 5 on the thiolactone ring which could react with halides to produce 5-substituted derivatives; the best reagent was two equivalents of lithium-bis-(trimethylsilyl)amide in tetrahydrofuran. The analogue with a 5-tetrahydrogeranyl substituent showed the best biological activity with an MIC(90) for M. tuberculosis of 29 micro M and 92% mycolate inhibition in extracts of M. smegmatis, as compared to 125 micro M and 54%, respectively, for TLM; other related C(10) and C(15) isoprenoid derivatives had similar biological activity. These isoprenoid-based derivatives did not inhibit type II fatty acid synthase from M. smegmatis, but compounds with iso-butyl and iso-butenyl side chains did show some inhibitory activity against this enzyme. These short-chain derivatives did not inhibit mycolate synthesis or have significant antibiotic activity. Treatment of the thiolactone with a weaker base, sodium hydride in tetrahydrofuran, gave 3-alkyl-3,5-dimethyl-thiophene-2,4-dione analogues, which had no effect on fatty acid or mycolate synthesis. However, the geranyl derivative had an MIC(99) of 60 micro M for M. tuberculosis, one quarter that (240 micro M) of TLM, demonstrating its excellent antibiotic potential against an unknown cellular target.