Preclinical safety testing and initial experience of a morcellation bag with four sealable ports.

Electromechanical morcellation-so called power morcellation-is a minimally invasive approach to remove bulky lesions such as uterine fibroids. The spread of benign and malignant tissue due to morcellation is a major concern that might limit the use of laparoscopic interventions. We present an in vitro evaluation of the safety characteristics of a four-port endobag with closable trocar sleeves, and describe physical properties of the bag that may or may not allow passage through the hole.

Above-ground biomass references for urban trees from terrestrial laser scanning data.

Background And Aims: Within extending urban areas, trees serve a multitude of functions (e.g. carbon storage, suppression of air pollution, mitigation of the 'heat island' effect, oxygen, shade and recreation).

Biomechanical properties of the hypoxic and dying brain quantified by magnetic resonance elastography.

Respiratory arrest is a major life-threatening condition leading to cessation of vital functions and hypoxic-anoxic injury of the brain. The progressive structural tissue changes characterizing the dying brain biophysically are unknown. Here we use noninvasive magnetic resonance elastography to show that biomechanical tissue properties are highly sensitive to alterations in the brain in the critical period before death.

Sensitivity of multifrequency magnetic resonance elastography and diffusion-weighted imaging to cellular and stromal integrity of liver tissue.

Microscopic structural alterations of liver tissue induced by freeze-thaw cycles give rise to palpable property changes. However, the underlying damage to tissue architecture is difficult to quantify histologically, and published data on macroscopic changes in biophysical properties are sparse. To better understand the influence of hepatic cells and stroma on global biophysical parameters, we studied rat liver specimens freshly taken (within 30 min after death) and treated by freeze-thaw cycles overnight at either -20 °C or -80 °C using diffusion-weighted imaging (DWI) and multifrequency magnetic resonance elastography (MRE) performed at 0.

Therapeutic Perspectives on Chia Seed and Its Oil: A Review.

The attraction of novel foods proceeds alongside epidemic cardiovascular disease, diabetes, obesity, and related risk factors. Dieticians have identified chia () as a product with a catalog of potential health benefits relating to these detriments. Chia is currently consumed not only as seeds, but also as oil, which brings about similar effects.

Synthesis of europium-doped VSOP, customized enhancer solution and improved microscopy fluorescence methodology for unambiguous histological detection.

Background: Intrinsic iron in biological tissues frequently precludes unambiguous the identification of iron oxide nanoparticles when iron-based detection methods are used. Here we report the full methodology for synthesizing very small iron oxide nanoparticles (VSOP) doped with europium (Eu) in their iron oxide core (Eu-VSOP) and their unambiguous qualitative and quantitative detection by fluorescence.

Methods And Results: The resulting Eu-VSOP contained 0.

Tree biomass in the Swiss landscape: nationwide modelling for improved accounting for forest and non-forest trees.

Trees outside forest (TOF) can perform a variety of social, economic and ecological functions including carbon sequestration. However, detailed quantification of tree biomass is usually limited to forest areas. Taking advantage of structural information available from stereo aerial imagery and airborne laser scanning (ALS), this research models tree biomass using national forest inventory data and linear least-square regression and applies the model both inside and outside of forest to create a nationwide model for tree biomass (above ground and below ground).

Plasmodium falciparum Thioredoxin Reductase (PfTrxR) and Its Role as a Target for New Antimalarial Discovery.

The growing resistance to current antimalarial drugs is a major concern for global public health. The pressing need for new antimalarials has led to an increase in research focused on the Plasmodium parasites that cause human malaria. Thioredoxin reductase (TrxR), an enzyme needed to maintain redox equilibrium in Plasmodium species, is a promising target for new antimalarials.

Study of long term radon transport by measuring the difference of the 210Pb and 226Ra activity in soil as a function of the depth.

Long term radon transport has been studied by measuring the activity difference of 210Pb and 226Ra in soil as a function of the depth. The results are from test pits of 1-2 m depth made at a dam of a tailings pond and at the plateau of a waste rock pile. Soil samples of about 1 kg were taken at a successive distances of 5 cm and analyzed by means of gamma-ray spectroscopy using low background germanium n-type detectors.

Sixty years of thiamin diphosphate biochemistry.

The mechanism of ThDP enzymes originates in the anionic (ylid) structure of the coenzyme. On the other hand, no ylid species (as permanently existing structure) could be detected by 13C2-NMR studies with PDC (yeast), when the cofactor binds to the active site. Therefore, the rate of ylid formation as the first step of the catalytic mechanism distinguishes decisively the power (kcat) of all ThDP enzymes.

The presence of a hydroxyl group at the C-1 atom of the transketolase substrate molecule is necessary for the enzyme to perform the transferase reaction.

Transketolase catalyzes the transfer of an aldehyde residue from keto sugars to aldo sugars. The intermediate product is dihydroxyethylthiamine pyrophosphate (DHETPP). In the absence of an acceptor substrate, the reaction is stopped at this stage and DHETPP does not undergo subsequent transformations.

Specificity of coenzyme binding in thiamin diphosphate-dependent enzymes. Crystal structures of yeast transketolase in complex with analogs of thiamin diphosphate.

The three-dimensional structures of complexes of yeast apotransketolase with the coenzyme analogs 6'-methyl, N1'-pyridyl, and N3'-pyridyl thiamin diphosphate, respectively, were determined with protein crystallographic methods. All three coenzyme analogs bind to the enzyme in a fashion highly similar to the cofactor thiamin diphosphate. Thus, either one of the hydrogen bonds of the pyrimidine ring nitrogens to the protein is sufficient for proper binding and positioning of the cofactor.

Effects of metal ions, thiamine diphosphate analogues and subunit interactions on the reconstitution behaviour of pyruvate decarboxylase from brewer's yeast.

The reconstitution of pyruvate decarboxylase starts with reversible binding of thiamine diphosphate and Mg2(+)-ions to the apoenzyme, followed by a rate-limiting conformational change to the catalytically active holoenzyme. Investigations with diphospho-esters of 4-methyl-5-(2-hydroxyethyl)thiazolium derivatives have shown that the diphosphate residue of thiamine diphosphate is the most important part of the coenzyme responsible for the first reversible binding step. Methylation of the N1'-atom of the pyrimidine ring of thiamine diphosphate or 4'-oxythiamine diphosphate prevents the coenzyme from binding stably to the apoenzyme, so that the methylated coenzyme displays no coenzyme activity.

Subsite affinities of Aspergillus niger glucoamylase II determined with p-nitrophenylmaltooligosaccharides.

Kinetic parameters were obtained for glucoamylase catalysed hydrolysis of substrates of an alpha-(1,4)-maltooligosaccharide series and of a p-nitro-phenyl-alpha-maltooligosaccharide series. p-Nitrophenyl substrates of chain length 11 and 17 were synthesized in 97% and 95% purity, respectively, to test the significance of binding at remote subsites. The affinities of the subsites > 4 are demonstrated to be insignificant.

The influence of the effectors of yeast pyruvate decarboxylase (PDC) on the conformation of the dimers and tetramers and their pH-dependent equilibrium.

The influence of effectors of yeast pyruvate decarboxylase, phosphate, pyruvamide, thiamin diphosphate and Mg++, on the pH-dependent equilibrium between dimers and tetramers was studied by synchrotron radiation X-ray solution scattering. Thiamin diphosphate and phosphate shift the equilibrium to higher pH values without altering the structure of the oligomers. Pyruvamide, a substrate analogue activator, induces a significant change in the structure of the tetramer.

Application of polystyrene-bound invertase to continuous sucrose hydrolysis on pilot scale.

Invertase from baker's yeast (Saccharomyces cerevisiae) covalently bound to a macroporous polystyrene anion-exchange resin via glutaraldehyde was applied to continuous sucrose hydrolysis in packed bed-reactors. The process was scaled up from 3-mL laboratory reactors via 0.3-L reactors to pilot-scale 50-L reactors without significant loss of efficiency.

Synchrotron radiation solution X-ray scattering study of the pH dependence of the quaternary structure of yeast pyruvate decarboxylase.

The pH dependence of the quaternary structure of pyruvate decarboxylase from yeast was studied in the range 6.2 less than pH less than 8.4.

The catalytic power of pyruvate decarboxylase. A stochastic model for the molecular evolution of enzymes.

Pyruvate decarboxylase (PDC) catalyzes the decarboxylation of pyruvate anion by a factor of around 10(12), compared with the non-enzymic decarboxylation by thiamine, under standard state conditions of 1 mM pyruvate and thiamine diphosphate (TDP), pH 6.2. Free-energy diagrams constructed on the basis of earlier measurements for the enzymic and non-enzymic reactions give some information on catalysis by PDC.

Kinetic mechanism of pyruvate decarboxylase. Evidence for a specific protonation of the enzymic intermediate.

Decarboxylation of pyruvate by pyruvate decarboxylase (EC 4.1.1.

Thiamin pyrophosphate binding mechanism and the function of the aminopyrimidine part.

Besides the pyrophosphate group, acting as the essential and primary binding function of TPP the N1-atom of the aminopyrimidine component functions as a second and also essential anchor to the protein component. Only if both of the contacts are formed the productive conformation of TPP within the active site of TPP enzymes is realized. A mechanism is proposed, which explains the results of our experiments with TPP-analogs.

Interaction of invertase with polyelectrolytes.

In connection with our work on polyelectrolyte complex formation with polyampholytes, the interaction between invertase and several linear polyelectorlytes has been investigated by means of turbidimetry, light scattering measurements, and determination of the enzyme activity. Polyelectrolyte complex formation of invertase was shown to occur with cationic polyelectrolytes only. The light-scattering data yield information on aggregation and desegregation processes in complex formation.

Immobilization of invertase by encapsulation in polyelectrolyte complexes.

Free and polystyrene-bound invertase from Saccharomyces cerevisiae were encapsulated within symplex membranes which were composed of cellulose sulfate as the polymeric anion and poly(dimethyldiallylammonium chloride) as the polymeric cation. The kinetics and the performance of the encapsulated enzyme preparations have been compared to the free enzyme employing the hydrolysis of sucrose. The pH and temperature optima were only slightly affected by the encapsulation.

Protein adsorption and leakage in carrier-enzyme systems.

The capability of binding enzymes adsorptively to unmodified and silanized silica and glass as well as modified polystyrene carriers was studied for alpha-amylase, beta-amylase, and alpha-chymotrypsin. In most cases a high percentage of protein was bound very firmly under considerable loss of activity. The leakage of protein from the carriers was studied by measuring the intrinsic protein fluorescence on beta-amylase adsorptively bound to aminopropyl silica, aminomethyl, and hexadecylaminomethyl polystyrene.