Investing in green and white biotech

A substantial increase in political and financial investment that aligns plant and industrial biotech will pay dividends for sustainable energy and materials production.     

And then there were acyl coenzyme A:cholesterol acyl transferase inhibitors

PURPOSE OF REVIEW: The reputation of acyl coenzyme A:cholesterol acyltransferase (ACAT) inhibitors has changed profoundly from promising new drugs for cardiovascular prevention to drugs without clinical benefits or possibly even with adverse effects. RECENT FINDINGS: ACAT inhibitors decrease the intracellular conversion of free cholesterol into cholesteryl ester in a number of tissues, including intestine, liver and macrophages. In contrast to promising results in experimental animal models, all subsequent clinical studies in humans with ACAT inhibitors failed to show lipid profile changes as well as reductions in surrogate markers for coronary artery disease. In fact, there was even a tendency towards an increase in atheroma burden in the most recent and well executed clinical trials. In addition, the inhibition of this pivotal enzyme in cholesterol esterification may interfere with reverse cholesterol transport. SUMMARY: In our opinion, the consistent negative findings in recent clinical trials have virtually eliminated the chances for this class of drugs to be introduced for cardiovascular prevention. Possible strategies focused on selective ACAT 2 inhibition or the combination of ACAT inhibitors with compounds that stimulate reverse cholesterol transport may prove to have clinical benefit. This will have to await further clinical research in humans, however, as, obviously, rodent models cannot provide reliable data as to the efficacy of this class of drugs in humans.     

DHAP-dependent aldolases from (hyper)thermophiles: biochemistry and applications

Generating new carbon–carbon (C–C) bonds in an enantioselective way is one of the big challenges in organic synthesis. Aldolases are a natural tool for stereoselective C–C bond formation in a green and sustainable way. This review will focus on thermophilic aldolases in general and on dihydroxyacetone phosphate-dependent aldolases in particular. Biochemical properties and applications for synthesis of rare sugars and carbohydrates will be discussed.     

Real-time three-dimensional transthoracic echocardiography in daily practice: initial experience

Aim of the work

To evaluate the feasibility and possible additional value of transthoracic real-time three-dimensional echocardiography (RT3D-TTE) for the assessment of cardiac structures as compared to 2D-TTE.

Methods

320 patients (mean age 45 ± 8.4 years, 75% males) underwent 2D-TTE and RT3D-TTE using 3DQ-Q lab software for offline analysis. Volume quantification and functional assessment was performed in 90 patients for left ventricle and in 20 patients for right ventricle. Assessment of native (112 patients) and prosthetic (30 patients) valves morphology and functions was performed. RT3D-TTE was performed for evaluation of septal defects in 30 patients and intracardiac masses in 52 patients.

Results

RT3D-TTE assessment of left ventricle was feasible and reproducible in 86% of patients while for right ventricle, it was (55%). RT3D-TTE could define the surface anatomy of mitral valve optimally (100%), while for aortic and tricuspid was (88% and 81% respectively). Valve area could be planimetered in 100% for the mitral and in 80% for the aortic. RT3D-TTE provided a comprehensive anatomical and functional evaluation of prosthetic valves. RT3D-TTE enface visualization of septal defects allowed optimal assessment of shape, size, area and number of defects and evaluated the outcome post device closure. RT3D-TTE allowed looking inside the intracardiac masses through multiple sectioning, valuable anatomical delineation and volume calculation.

Conclusion

Our initial experience showed that the use of RT3D-TTE in the assessment of cardiac patients is feasible and allowed detailed anatomical and functional assessment of many cardiac disorders.     

Using wintergreen oil for mounting mosquito larvae: a safer alternative to xylene

Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents.     

The role of the apex in the phototropic curvature of Avena coleoptiles: positive curvature under conditions of continuous illumination

The differential growth causing second positive phototropic curvature in intact, black-capped and decapitated Avena coleoptiles has been measured. In all cases the curvature is brought about by a cessation in growth of the illuminated side. The fact that shading the apex does not significantly alter the initial steps of differential growth means that the subapical zones can perceive and respond to unilateral illumination. Decapitation significantly reduces coleoptile growth, especially in the most apical zone. However, the fact that differential growth is still evident in the other zones of decapitated coleoptiles within 30 min of unilateral illumination requires one to conclude that the apex cannot be controlling the differential growth in those basal zones.     

Chloroperoxidase-Catalysed Halogenation of Apolar Compounds Using Reversed Micelles

The chloroperoxidase from the mold Caldariomyces fumago was entrapped into reversed micelles composed of aqueous buffer, cetyltrimethylammonium chloride or bromide, pentanol and octane. The surfactant serves a dual function: i) it stabilizes the reversed micelle, and ii) the halide counter ion is used as a substrate for the enzyme. 2-Monochlorodimedon and 1,3-dihydroxybenzene were halogenated with this system, giving their 2-halo and 4-halo derivatives, respectively. The reaction rates were about twice as high as in aqueous media. Enzyme activity was maximal at high water content of the micelles and at relatively low pentanol concentration. The enzyme was inactivated by high concentrations of hydrogen peroxide.     

Downstream processing of enzymatically produced geranyl glucoside

Geraniol plays an important role in the fragrance and flavor industry. The corresponding glucoside has interesting properties as a "slow release" aroma compound. Therefore, the enzymatic production and downstream processing of geranyl glucoside were investigated. Geranyl glucoside was produced in a spray column reactor with an initial production rate of 0.58 mg x U(-1) x h(-1). A pretreated hydrophobic microfiltration membrane was used to prevent migration of the aqueous, enzyme-containing phase to the downstream process. No retention of the glucoside, which accumulated in the geraniol phase, was found. On the basis of examples from the literature, four downstream processes were tested on their viability for this system. Extraction with water and foaming were not suitable to recover geranyl glucoside from geraniol. In the first case, the glucoside selectivity for the geraniol phase was found to be high, which made extraction with water unsuccessful. In the second case it was possible to obtain a stable foam, but significant enrichment of the foam with glucoside did not occur. Adsorption on alumina and distillation under reduced pressure were applied successfully and tested in-line with the bioreactor. A maximum glucoside adsorption of 7.86 mg x g(-1) was achieved on alumina. After desorption and evaporation of the extractant the pure glucoside was obtained quantitatively. A pure product could not be obtained after distillation because a small amount of glucose was present in the permeate as well, which accumulated in the bottom fraction. It was shown that with this reactor system a production of 1 kg of geranyl glucoside in 2 days is possible using an initial amount of 50,000 units of enzyme.