Recurrent gastric lactobezoar in an infant

Lactobezoars are a type of bezoar composed of undigested milk and mucus. The aetiology is likely multifactorial, being classically described in association with pre-term, low-birth weight infants fed with hyperconcentrated formula. The authors present a case of lactobezoar recurrence in a pre-term infant with oesophageal atresia. To our knowledge, this is the first report of recurrence of lactobezoar.info:eu-repo/semantics/publishedVersio

Functional expression of a penicillin acylase from the extreme thermophile Thermus thermophilus HB27 in Escherichia coli

Background: Penicillin acylases (PACs) are enzymes of industrial relevance in the manufacture of beta-lactam antibiotics. Development of a PAC with a longer half-life under the reaction conditions used is essential for the improvement of the operational stability of the process. A gene encoding a homologue to Escherichia coli PAC was found in the genome of the thermophilic bacterium Thermus thermophilus (Tth) HB27. Because of the nature of this PAC and its complex maturation that is crucial to reach its functional heterodimeric final conformation, the overexpression of this enzyme in a heterologous mesophilic host was a challenge. Here we describe the purification and characterization of the PAC protein from Tth HB27 overexpressed in Escherichia coli. Results: Fusions to a superfolder green fluorescent protein and differential membrane solubilization assays indicated that the enzyme remains attached through its amino-terminal end to the outer side of the cytoplasmic membrane of Tth cells. In order to overexpress this PAC in E. coli cells, a variant of the protein devoid of its membrane anchoring segment was constructed. The effect of the co-expression of chaperones and calcium supplementation of the culture medium was investigated. The total production of PAC was enhanced by the presence of DnaK/J and GrpE and even more by trigger factor and GroEL/ES. In addition, 10 mM calcium markedly improved both PAC specific and volumetric activities. Recombinant PAC was affinity-purified and proper maturation of the protein was confirmed by SDS-PAGE and MALDI-TOF analysis of the subunits. The recombinant protein was tested for activity towards several penicillins, cephalosporins and homoserine lactones. Hydrophobic acyl-chain penicillins were preferred over the rest of the substrates. Penicillin K (octanoyl penicillin) was the best substrate, with the highest specificity constant value (16.12 mM-1.seg-1). The optimum pH was aprox. 4 and the optimum temperature was 75 [DEGREE SIGN]C. The half-life of the enzyme at this temperature was 9.2 h. Conclusions: This is the first report concerning the heterologous expression of a pac gene from a thermophilic microorganism in the mesophilic host E. coli. The recombinant protein was identified as a penicillin K-deacylating thermozymeL.T., A.H. and J.B. acknowledge funding from the Spanish Ministry of Science (grants CIT 010000-2009-29, RyC2006-02441) and an institutional grant from Fundación Ramón Areces to CBMS

Syngamus trachea in free-ranging white stork (Ciconia ciconia) nestlings in Switzerland.

Syngamosis is a disease caused by the strongylid nematode Syngamus trachea, which infects the respiratory tract of various bird species around the world. The parasite appears to be harmful for a wide variety of avian orders, occasionally leading to a fatal outcome, particularly in young birds. The aim of this study was to examine the parasitic fauna in deceased or euthanized, free-ranging white storks nesting at the Zoo Basel in 2019 and 2020; and to assess the extent to which these parasites contributed to the wild birds' death. In five out of 24 necropsied white storks, an infection with S. trachea was diagnosed based on morphological analysis of adult nematode stages and eggs, in combination with PCR amplification and sequencing of DNA extracted from female worms. The main pathological changes affected the white storks' respiratory tract and a mixed cell tracheitis was diagnosed in the histopathological examination of three of the five infected birds. Some birds displayed additional lesions compatible with syngamosis, namely partially degenerated parasitic structures with concurrent granulomatous inflammation in the lung and multifocal acute hemorrhages in the bronchi and parabronchi. Coprological examinations (fecal flotation technique, fecal sedimentation technique, sodium acetate acetic acid formalin procedure and Ziehl-Neelsen staining) from the intestinal content as well as a PCR for Toxoplasma gondii on brain, lung, heart, liver, and spleen tissue yielded negative results in all examined individuals. In the absence of further major pathological findings, S. trachea was assumed to have significantly contributed to the death of the infected birds

Instability of insular tree communities in an Amazonian mega-dam is driven by impaired recruitment and altered species composition

Mega-dams create highly fragmented archipelagos, affecting biodiversity and ecosystem functioning in remnant forest isolates. This study assessed the long-term impact of dam-induced fragmentation on insular tropical tree communities, with the aim of generating robust recommendations to mitigate some of the detrimental biodiversity impacts associated with future dam development. We inventoried adult and sapling trees across 89 permanent plots, located on 36 islands and in three mainland continuous forest sites in the Balbina Dam, Brazilian Amazon. We examined differences in recruitment, structure, and composition of sapling and adult tree communities, in relation to plot-, patch- and landscape-scale attributes including area, isolation, and fire severity. Islands harboured significantly lower sapling (mean ± 95% CI 48.6 ± 3.8) and adult (5 ± 0.2) tree densities per 0.01 ha, than nearby mainland continuous forest (saplings, 65.7 ± 7.5; adults, 5.6 ± 0.3). Insular sapling and adult tree communities were more dissimilar than in mainland sites, and species compositions showed a directional shift away from mainland forests, induced by fire severity, island area, and isolation. Insular sapling recruitment declined with increasing fire severity; tree communities with higher community-weighted mean wood density showed the greatest recruitment declines. Our results suggest that insular tree communities are unstable, with rare species becoming extinction-prone due to reduced tree recruitment and density on islands, potentially leading to future losses in biodiversity and ecosystem functioning across Balbina's >3,500 reservoir islands. Policy implications. In Balbina, fire and reduced habitat area and connectivity were drivers of tree community decay after only 28 years of insularization, despite strict protection provided by the ~940,000 ha Uatumã Biological Reserve. Given that many dams are planned for lowland, moderately undulating Amazonia, we recommend that dam development strategy explicitly considers (a) dam location, aiming to minimize creation of small (<10 ha) and isolated islands, (b) maintaining reservoir water levels during droughts to reduce fire risk, and (c) including aggregate island area in environmental impact and offset calculations. Ideally, we recommend that alternatives to hydropower be sought in lowland tropical regions, due to the far-reaching biodiversity losses and ecosystem disruption caused by river impoundment

Bronchogenic cyst excision using a robotic laparoscopic transdiaphragmatic approach

AbstractWe describe one case of a bronchopulmonary foregut malformations (BPFM) excision using robotic technology in a pediatric patient. Traditionally, surgical resection is performed using a thoracotomy or video-assisted thoracic surgery. A 12-year-old girl with a previous medical history of cough was diagnosed with a left cystic paracardiac mass. Her operation employed a transdiaphragmatic approach to remove the mass. The postoperative course was uneventful, and she was discharged after four days. The subsequent pathology concluded that the mass was a bronchogenic cyst. To the best of our knowledge, this is the first report of transdiaphragmatic laparoscopic approach and first use of robotics-platform for BPFM excision by children. We elected to use this type of procedure to decrease the postoperative morbidity associated with the thoracic approach. The robotic technology permitted surgical resection with a similar efficiency as standard thoracic or laparoscopic procedures. We hypothesized that this technology would simplify some of the technical points, decreasing any postoperative complications

Study of non-equilibrium effects and thermal properties of heavy ion collisions using a covariant approach

Non-equilibrium effects are studied using a full Lorentz-invariant formalism. Our analysis shows that in reactions considered here, no global or local equilibrium is reached. The heavier masses are found to be equilibrated more than the lighter systems. The local temperature is extracted using hot Thomas Fermi formalism generalized for the case of two interpenetrating pieces of nuclear matter. The temperature is found to vary linearly with bombarding energy and impact parameter whereas it is nearly independent of the mass of the colliding nuclei. This indicates that the study of temperature with medium size nuclei is also reliable. The maximum temperatures obtained in our approach are in a nice agreement with earlier calculations of other approaches. A simple parametrization of maximal temperature as a function of the bombarding energy is also given.Comment: LaTex-file, 17 pages, 8 figures (available upon request), Journal of Physics G20 (1994) 181

Cyclohexanedione as the negative electrode reaction for organic redox flow batteries

The electrochemical reduction and oxidation of cyclohexanedione is evaluated for the first time as the negative electrode reaction in an organic redox flow battery. Electrochemical characterization indicates that the redox reaction of cyclohexanedione is a proton-coupled electron transfer process with quasi-reversible behavior in acidic media (pH 2 M) and exhibit reduction process with up to 4 electrons transferred

Engineering the substrate specificity of a thermophilic penicillin acylase from thermus thermophilus

A homologue of the Escherichia coli penicillin acylase is encoded in the genomes of several thermophiles, including in different Thermus thermophilus strains. Although the natural substrate of this enzyme is not known, this acylase shows a marked preference for penicillin K over penicillin G. Three-dimensional models were created in which the catalytic residues and the substrate binding pocket were identified. Through rational redesign, residues were replaced to mimic the aromatic binding site of the E. coli penicillin G acylase. A set of enzyme variants containing between one and four amino acid replacements was generated, with altered catalytic properties in the hydrolyses of penicillins K and G. The introduction of a single phenylalanine residue in position α188, α189, or β24 improved the Km for penicillin G between 9- and 12-fold, and the catalytic efficiency of these variants for penicillin G was improved up to 6.6-fold. Structural models, as well as docking analyses, can predict the positioning of penicillins G and K for catalysis and can demonstrate how binding in a productive pose is compromised when more than one bulky phenylalanine residue is introduced into the active site. © 2013, American Society for Microbiology.Spanish Ministry of Science (CIT no. 010000-2009-29, RyC2006-02441, and BIO2010-18875); Fundación Ramón ArecesPeer Reviewe

Local Thermal and Chemical Equilibration and the Equation of State in Relativistic Heavy Ion Collisions

Thermodynamical variables and their time evolution are studied for central relativistic heavy ion collisions from 10.7 to 160 AGeV in the microscopic Ultrarelativistic Quantum Molecular Dynamics model (UrQMD). The UrQMD model exhibits drastic deviations from equilibrium during the early high density phase of the collision. Local thermal and chemical equilibration of the hadronic matter seems to be established only at later stages of the quasi- isentropic expansion in the central reaction cell with volume 125 fm$^{3}$. distributions at all collision energies for $t\geq 10 fm/c$ with a unique Baryon energy spectra in this cell are approximately reproduced by Boltzmann rapidly dropping temperature. At these times the equation of state has a simple form: $P \cong (0.12-0.15) \epsilon$. At 160 AGeV the strong deviation from chemical equilibrium is found for mesons, especially for pions, even at the late stage of the reaction. The final enhancement of pions is supported by experimental data.Comment: 17 Pages, LaTex, 8 eps figures. Talk given at SQM'98 conference, 20-24 July 1998, Padova, Italy, submitted to J. Phys.