Optimizing production of extracellular lipase fromRhodotorula glutinis

Production of extracellular lipase byRhodotorula glutinis was substantially enhanced when the type and concentration of carbon and nitrogen source, the initial pH of culture medium and the growth temperature were consecutively optimized. Lipase activity as high as 30.4 U/ml of culture medium was obtained at optimum conditions, comparing favourably with most of the activities reported for other lipase hyperproducing microorganisms. The enzyme was optimally active at pH 7.5 and 35°C and had, at optimum pH, half-lives of 45 and 11.8 min at 45 and 55°C respectively. The high activity and kinetic characteristics of the enzyme make this process worthy of further investigation.     

Prediction of Ovarian Hyperstimulation Syndrome in Patients Treated with Corifollitropin alfa or rFSH in a GnRH Antagonist Protocol

Study Question

What is the threshold for the prediction of moderate to severe or severe ovarian hyperstimulation syndrome (OHSS) based on the number of growing follicles ≥ 11 mm and/or estradiol (E₂) levels?

Summary Answer

The optimal threshold of follicles ≥11 mm on the day of hCG to identify those at risk was 19 for both moderate to severe OHSS and for severe OHSS. Estradiol (E₂) levels were less prognostic of OHSS than the number of follicles ≥ 11 mm.

What Is Known Already

In comparison to long gonadotropin-releasing hormone (GnRH) agonist protocols, the risk of severe OHSS is reduced by approximately 50% in a GnRH antagonist protocol for ovarian stimulation prior to in vitro fertilisation (IVF), while the two protocols provide equal chances of pregnancy per initiated cycle. Nevertheless, moderate to severe OHSS may still occur in GnRH antagonist protocols if human chorionic gonadotropin (hCG) is administered to trigger final oocyte maturation, especially in high responder patients. Severe OHSS following hCG trigger may occur with an incidence of 1–2% in a relatively young (aged 18 to 36 years) IVF population treated in a GnRH-antagonist protocol.

Study Design, Size, Duration

From the Engage, Ensure and Trust trials, in total, 2,433 women who received hCG for oocyte maturation and for whom the number of follicles ≥ 11 mm and the level of E₂ on the day of hCG administration were known were included in the analyses.

Participants/Materials, Setting, Methods

The threshold for OHSS prediction of moderate and severe OHSS was assessed in women treated with corifollitropin alfa or daily recombinant follicle stimulation hormone (rFSH) in a gonadotropin-releasing hormone (GnRH)-antagonist protocol. Receiver operating characteristics curve analyses for moderate to severe OHSS and severe OHSS were performed on the combined dataset and the sensitivity and specificity for the optimal threshold of number of follicles ≥ 11 mm, E₂ levels on the day of (hCG), and a combination of both, were determined.

Main Results and the Role of Chance

The optimal threshold of follicles ≥ 11 mm on the day of hCG to identify those at risk of moderate to severe OHSS was 19 (sensitivity and specificity 62.3% and 75.6%, respectively) and for severe OHSS was also 19 (sensitivity and specificity 74.3% and 75.3%, respectively). The positive and negative predictive values were 6.9% and 98.6%, respectively, for moderate to severe OHSS, and 4.2% and 99.5% for severe OHSS.

Limitations, Reasons for Caution

This was a retrospective analysis of combined data from three trials following ovarian stimulation with two different gonadotropins.

Wider Implications of the Findings

For patients with 19 follicles or more ≥11 mm on the day of hCG, measures to prevent the development of OHSS should be considered. Secondary preventive measures include cycle cancellation or coasting, use of a GnRH agonist to trigger final oocyte maturation in place of hCG and a freeze all strategy.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00702845","term_id":"NCT00702845"}}NCT00702845{"type":"clinical-trial","attrs":{"text":"NCT00696800","term_id":"NCT00696800"}}NCT00696800{"type":"clinical-trial","attrs":{"text":"NCT00696878","term_id":"NCT00696878"}}NCT00696878     

Enhanced bronchoconstriction responses to prostaglandin F2α following inhalation of sulfur dioxide

The effect of chronic sulfur dioxide (SO₂) inhalation was investigated in pharmacologic-induced bronchoconstruction in beagle dogs. Increase in pulmonary resistance (R_L) and decrease in dynamic lung compliance (C_DYN) were observed with i.v. and aerosol administration of prostaglandin F_2α (PGF_2α). After control historical data were accumulated, the animals received exposures of 500 ppm of SO₂ for two hours twice a week. After six months of chronic SO₂ exposure, a significant enhancement in the R_L response to i.v. and aerosolized PGF_2α was observed as compared to pre-SO₂ data. Tracheobronchial inflammation, as observed by fiberoptic bronchoscopy, occurred as a result of the chronic inhalation of SO₂; however, only a small increase in mucous production was observed visually. In additon, hypercapnic and acidotic changes in blood gas profiles were found. Therefore, beagle dogs chronically exposed to SO₂, developed hyperactive airways as seen by increased sensitivity to PGF_2α. This model appears to reflect many of those changes observed in clinical bronchial hyperreactivity and may provide an additional insight into obstructive disease.     

Spectral characteristics of the bioluminescence induced in the marine fish,Porichthys notatus,byCypridina (ostracod) luciferin

Summary Specimens ofPorichthys notatus, which are naturally luminous along the coast of California, are non-luminous in Puget Sound. However, luminescence capability may be induced in the adult Puget SoundPorichthys by the administration of purifiedCypridina (ostracod) luciferin, syntheticCypridina luciferin, orCypridina organisms. The bioluminescence emission spectra produced by the Puget Sound fish following induction is similar, if not identical, to that of the naturally luminousPorichthys notatus from California waters (maxima: 485 and 507 nm).