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The Spf1p protein from Saccharomyces cerevisiae belongs to the family of P5A-ATPases that have recently been shown to protect the endoplasmic reticulum by dislocating misinserted membrane proteins. The loss of function of P5A-ATPases leads to endoplasmic reticulum stress with a pleiotropic phenotype including protein, sterol and metal ion dyshomeostasis. Like other P-ATPases, Spf1p requires Mg

Angiotensin-converting enzyme 2 (ACE2) is the receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which causes COVID-19. Viral entry requires ACE2 and transmembrane protease serine 2 (TMPRSS2). Transcriptomic studies showed that children display lower ACE2 than adults, though gene expression levels do not always correlate with protein levels. We investigated the effect of age on ACE2 and TMPRSS2 protein expression in alveolar type II (AT2) cells in the lungs of children compared to adults. We also analysed the ratio of Ang-(1-7) to Ang II as a surrogate marker of ACE2 activity in the subjects' lung parenchyma.Ang II and Ang-(1-7) levels and ACE2 and TMPRSS2 protein expression were measured by radioimmunoassay and immunohistochemistry, respectively.The amount of ACE2-expressing AT2 cells and ACE2 protein content were lower in children than in adults. Ang II levels were higher in children compared to adults and inversely correlated with the amount of ACE2-expressing AT2 cells. Children presented lower Ang-(1-7)/Ang II ratio than adult suggesting lower ACE2 activity in children. TMPRSS2 protein expression was not influenced by age.These results expand on previous transcriptomic studies and may partially explain the low susceptibility of children to SARS-CoV-2 infection.Clinical original research IMPACT: Children display lower ACE2 protein content and activity compared to adults. Ang II levels were higher in children compared to adults and inversely correlated with the amount of ACE2-expressing AT2 cells TMPRSS2 protein expression was not influenced by age. These results expand on previous transcriptomic studies and may partially explain the low susceptibility of children to SARS-CoV-2 infection.

Aims Angiotensin-converting enzyme (ACE) 2 is the receptor for severe acute respiratory syndrome coronavirus 2 which causes coronavirus disease 2019 (COVID-19). Viral cellular entry requires ACE2 and transmembrane protease serine 2 (TMPRSS2). ACE inhibitors (ACEIs) or angiotensin (Ang) receptor blockers (ARBs) influence ACE2 in animals, though evidence in human lungs is lacking. We investigated ACE2 and TMPRSS2 in type II pneumocytes, the key cells that maintain lung homeostasis, in lung parenchymal of ACEI/ARB-treated subjects compared to untreated control subjects. Main methods Ang II and Ang-(1–7) levels and ACE2 and TMPRSS2 protein expression were measured by radioimmunoassay and immunohistochemistry, respectively. Key findings We found that the ratio Ang-(1–7)/Ang II, a surrogate marker of ACE2 activity, as well as the amount of ACE2-expressing type II pneumocytes were not different between ACEI/ARB-treated and untreated subjects. ACE2 protein content correlated positively with smoking habit and age. The percentage of TMPRSS2-expressing type II pneumocytes was higher in males than females and in subjects under 60 years of age but it was not different between ACEI/ARB-treated and untreated subjects. However, there was a positive association of TMPRSS2 protein content with age and smoking in ACEI/ARB-treated subjects, with high TMPRSS2 protein levels most evident in ACEI/ARB-treated older adults and smokers. Significance ACEI/ARB treatment influences human lung TMPRSS2 but not ACE2 protein content and this effect is dependent on age and smoking habit. This finding may help explain the increased susceptibility to COVID-19 seen in smokers and older patients with treated cardiovascular-related pathologies.

An important aim of undergraduate science education is to develop student skills in reading and evaluating research papers. We have designed, developed, and implemented an on-line interactive resource entitled “Evaluating Scientific Research literature” (ESRL) aimed at students from the first 2 years of the undergraduate program. In this article, we describe the resource, then use student data collected from questionnaire surveys to evaluate the resource within 2 years of its launch. Our results add to those reported previously and indicate that ESRL can enable students to start evaluating research articles when used during their undergraduate program. We conclude maximal learning is likely to occur when the resource can be embedded in the curriculum such that students have a clearly articulated context for the resource's activities, can see their relevance in relation to assessed assignments and can be encouraged to think deeply about the activities in conversation with one another and/or with staff. © 2017 by The International Union of Biochemistry and Molecular Biology, 2017.

Critically evaluating research papers is an important vehicle for promoting acculturation into a scientific discipline. As science students progress through their undergraduate studies, their critical abilities are expected to become heightened, and research papers are read and cited in order to support a variety of assignments, such as essays, critical reviews and presentations, progressing to shaping laboratory research projects and dissertation-writing. This article describes the process of designing a modular online resource. The resource is aimed at familiarising students with the structural conventions and argumentative devices used in research papers and supporting them in deep-reading a research paper in life sciences or chemistry. The modules employ audio- and video-recorded extracts from interviews with a key author to provide a context for the origins, motivations and processes behind the writing of a specific paper, plus scaffolded questions to encourage critical evaluation of the paper. Notable features of the project were the employment of a multi-disciplinary team of staff and research postgraduates coupled with the developmental testing of the resource by undergraduates. Lessons learnt from the project are considered, including the resource’s integration within the curriculum and the challenges of writing such interactive resources for different disciplines.

X-ray crystallography is a core technique underpinning many important results in the field of biochemistry. Although most biochemists will not become experts in this technique, many will use the structural models deposited in the protein data bank for designing and interpreting other experiments. Since there are a number of limitations to these models, it is important that undergraduate biochemists, as potential end-users of this technique, have some understanding of how these models are produced. A computer activity is described in which the program WinCoot is used to build part of a protein model to interpret an electron density map. This activity allows students to experience the nature of crystallographic data first-hand and discover how protein structural models are produced.

Angiotensin-I-converting enzyme (ACE) plays a critical role in the regulation of blood pressure through its central role in the renin-angiotensin and kallikrein-kinin systems. ACE contains two domains, the N and C domains, both of which are heavily glycosylated. Structural studies of ACE have been fraught with severe difficulties because of surface glycosylation of the protein. In order to investigate the role of glycosylation in the N domain and to create suitable forms for crystallization, we have investigated the importance of the 10 potential N-linked glycan sites using enzymatic deglycosylation, limited proteolysis, and mass spectrometry. A number of glycosylation mutants were generated via site-directed mutagenesis, expressed in CHO cells, and analyzed for enzymatic activity and thermal stability. At least eight of 10 of the potential glycan sites are glycosylated; three C-terminal sites were sufficient for expression of active N domain, whereas two N-terminal sites are important for its thermal stability. The minimally glycosylated Ndom389 construct was highly suitable for crystallization studies. The structure in the presence of an N domain-selective phosphinic inhibitor RXP407 was determined to 2.0 A resolution. The Ndom389 structure revealed a hinge region that may contribute to the breathing motion proposed for substrate binding.

Angiotensin I-converting enzyme (ACE) plays a key role in the renin-angiotesin aldosterone cascade. We analysed the secondary structure and structural organization of a purified 65kDa N-domain ACE (nACE) from Wistar rat mesangial cells, a 90 kDa nACE from spontaneously hypertensive rats and a 130 kDa somatic ACE. The C-terminal alignment of the 65 kDa nACE with rat ACE revealed that the former was truncated at Ser(482), and the sequence of the 90 kDa nACE ended at Pro(629). Protein's secondary structure consisted predominantly of alpha-helices. The 90 and 65 kDa isoforms were the most stable in guanidine and at low pH, respectively. Enzymatic activity decreased with loss in secondary structure, except in the case of guanidine HCl where the 90 kDa fragment loses its secondary structure faster than its enzymatic activity. We identified and characterized the activity and stability of these isoforms and these findings would be helpful on the understanding of the role of nACE isoforms in hypertension.

Bluetooth modules are increasingly used in pervasive portable electronic items. In this paper, a flexible measurement-based power model for Bluetooth devices is proposed. This model has been used to implement a software simulator to estimate the average power consumption of Bluetooth modules under real operating conditions. The correctness of the assumptions underlying the model has experimentally been proven. In addition, the effect of measurement uncertainty is analyzed.

Angiotensin I-converting enzyme (ACE) is central to the regulation of the renin-angiotensin system and is a key therapeutic target for combating hypertension and related cardiovascular diseases. Currently available drugs bind both active sites of its two homologous domains, although it is now understood that these domains function differently in vivo. The recently solved crystal structures of both domains (N and C) open the door to new domain-specific inhibitor design, taking advantage of the differences between these two large active sites. Here we present the first crystal structure at a resolution of 2.25 Å of testis ACE (identical to the C domain of somatic ACE) with the highly C-domain-specific phosphinic inhibitor, RXPA380. Testis ACE retains the same conformation as seen in previously determined inhibitor complexes, but the RXPA380 central backbone conformation is more similar to that seen for the inhibitor captopril than enalaprilat. The RXPA380 molecule occupies more subsites of the testis ACE active site than the previously determined inhibitors and possesses bulky moieties that extend into the S2′ and S2 subsites. Thus the high affinity of RXPA380 for the testis ACE/somatic ACE C domain is explained by the interaction of these bulky moieties with residues unique to these domains, specifically Phe 391, Val 379, and Val 380, that are not found in the N domain. The characterization of the extended active site and the binding of a potent C-domain-selective inhibitor provide the first structural data for the design of truly domain-specific pharmacophores.

Significant climate risks are associated with a positive carbon-temperature feedback in northern latitude carbon-rich ecosystems, making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and quasi-continuous ecosystem observations of CO2 and CH4 fluxes. Experimental areas are located both in natural and in managed wetlands and cover a wide range of climatic regions, ecosystem types, and management practices. Based on direct observations we predict that sustained CH4 emissions in natural ecosystems are in the long term (i.e., several centuries) typically offset by CO2 uptake, although with large spatiotemporal variability. Using a space-for-time analogy across ecological and climatic gradients, we represent the chronosequence from natural to managed conditions to quantify the "cost" of CH4 emissions for the benefit of net carbon sequestration. With a sustained pulse-response radiative forcing model, we found a significant increase in atmospheric forcing due to land management, in particular for wetland converted to cropland. Our results quantify the role of human activities on the climate footprint of northern wetlands and call for development of active mitigation strategies for managed wetlands and new guidelines of the Intergovernmental Panel on Climate Change (IPCC) accounting for both sustained CH4 emissions and cumulative CO2 exchange.

Human angiotensin-converting enzyme is an important drug target for which little structural information has been available until recent years. The slow progress in obtaining a crystal structure was due to the problem of surface glycosylation, a difficulty that has thus far been overcome by the use of a glucosidase-1 inhibitor in the tissue culture medium. However, the prohibitive cost of these inhibitors and incomplete glucosidase inhibition makes alternative routes to minimizing the N-glycan heterogeneity desirable. Here, glycosylation in the testis isoform (tACE) has been reduced by Asn-Gln point mutations at N-glycosylation sites, and the crystal structures of mutants having two and four intact sites have been solved to 2.0 A and 2.8 A, respectively. Both mutants show close structural identity with the wild-type. A hinge mechanism is proposed for substrate entry into the active cleft, based on homology to human ACE2 at the levels of sequence and flexibility. This is supported by normal-mode analysis that reveals intrinsic flexibility about the active site of tACE. Subdomain II, containing bound chloride and zinc ions, is found to have greater stability than subdomain I in the structures of three ACE homologues. Crystallizable glycosylation mutants open up new possibilities for cocrystallization studies to aid the design of novel ACE inhibitors.

Lecithins, mainly composed of the phospholipids phosphatidylcholines (PC), have many different uses in the pharmaceutical and clinical field. PC are involved in structural and biological functions as membrane trafficking processes and cellular signaling. Considering the increasing applications of lecithin-based nanosystems for the delivery of therapeutic agents, the aim of the present work was to determine the effects of phosphatidylcholine nanoparticles over breast cancer cellular proliferation and signaling. PC dispersions at 0.01 and 0.1% (w/v) prepared in buffer pH 7.0 and 5.0 were studied in the MCF-7 breast cancer cell line. Neutral 0.1% PC-derived nanoparticles induced the activation of the MEK-ERK1/2 pathway, increased cell viability and induced a 1.2 fold raise in proliferation. These biological effects correlated with the increase of epidermal growth factor receptor (EGFR) content and its altered cellular localization. Results suggest that nanoparticles derived from PC dispersion prepared in buffer pH 7.0 may induce physicochemical changes in the plasma membrane of cancer cells which may affect EGFR cellular localization and/or activity, increasing activation of the MEK-ERK1/2 pathway and inducing proliferation. Results from the present study suggest that possible biological effects of delivery systems based on lecithin nanoparticles should be taken into account in pharmaceutical formulation design. Fil: Gándola, Yamila Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina Fil: Pérez, Sebastián E.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina Fil: Irene, Pablo Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina Fil: Sotelo, Ana Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina Fil: Miquet, Johanna Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina Fil: Corradi, Gerardo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina

139 patients undergoing cardiac surgery were included in a prospective, randomized trial. Patients were randomly allocated to receive cardiopulmonary bypass (CPB) with Trillium™ Biopassive Surface (TBS Group) coated oxygenators or conventional circuits (control group). 112 patients were studied with respect to postoperative biochemical profile; a subgroup of 27 patients was studied with respect to perioperative complement (C3a) activation. Patients in the TBS group demonstrated a significantly lower white blood cell count at the end of the operation (p=0.036) and a significantly higher platelet count the day after the operation (p=0.023) when compared to the control group. C3a was significantly higher (p=0.02) in the TBS group after 30 minutes of CPB, but the C3a increase after protamine administration was significantly less pronounced in the TBS group vs. the control group. Further studies involving platelet and leukocyte activation are required to better elucidate the action of this new coating in the setting of routine CPB.

Two synthetic routes to surface-aminated polypyrrole–silica nanocomposite particles have been investigated. Route 1 involved the initial synthesis of homopolypyrrole – silica particles as described previously, followed by surface amination using 3-aminopropyltriethoxy-silane. In Route 2 aminated polypyrrole–silica particles were synthesized directly by copolymerising an N-substituted aminopyrrole comonomer with pyrrole in the presence of an ultrafine silica sol. Both types of aminated particles were characterized in terms of their particle size and morphology, long-term colloid stability and degree of amination using transmission electron microscopy, disc centrifuge photosedimentometry and zeta potential measurements, respectively.

We describe some of our recent results on the characterization of aqueous colloidal dispersions of conducting polymer-inorganic oxide nanocomposite particles. Such colloids are easily prepared by synthesizing the conducting polymer in the presence of commercially available ultrafine silica (or tin(IV) oxide) particles in aqueous media. In the present study we present electrokinetic data as a function of pH for the following systems: polypyrrole-silica, carboxylic acid-functionalized polypyrrole-silica, amine-functionalized polypyrrole-silica, polyaniline-silica, and polypyrrole-tin(IV) oxide colloids. These data show that both the isoelectric points and zeta potentials of these nanocomposite dispersions are governed primarily by the nature of the charged groups at the inorganic oxide surface rather than by the conducting polymer component. This suggests that the inorganic oxide is the major component at the particle surface, which is consistent with the excellent long-term colloid stability of these dispersions. The aqueous electrophoresis measurements also indicate that our surface functionalization experiments were successful: Carboxylic acid groups can be incorporated via copolymerization using an appropriate functional pyrrole comonomer, while amine groups can be introduced via derivatization of the silica component using 3-aminopropyl triethoxysilane.

The P5-ATPases are important components of eukaryotic cells. They have been shown to influence protein biogenesis, folding, and transport. The knowledge of their biochemical properties is, however, limited, and the transported ions are still unknown. We expressed in Saccharomyces cerevisiae the yeast Spf1 P5A-ATPase containing the GFP fused at the N-terminal end. The GFP-Spf1 protein was localized in the yeast endoplasmic reticulum. Purified preparations of GFP-Spf1 hydrolyzed ATP at a rate of ~0.3-1 μmol of P(i)/mg/min and formed a phosphoenzyme in a simple reaction medium containing no added metal ions except Mg(2+). No significant differences were found between the ATPase activity of GFP-Spf1 and recombinant Spf1. Omission of protease inhibitors from the purification buffers resulted in a high level of endogenous proteolysis at the C-terminal portion of the GFP-Spf1 molecule that abolished phosphoenzyme formation. The Mg(2+) dependence of the GFP-Spf1 ATPase was similar to that of other P-ATPases where Mg(2+) acts as a cofactor. The addition of Mn(2+) to the reaction medium decreased the ATPase activity. The enzyme manifested optimal activity at a near neutral pH. When chased by the addition of cold ATP, 90% of the phosphoenzyme remained stable after 5 s. In contrast, the phosphoenzyme rapidly decayed to less than 20% when chased for 3 s by the addition of ADP. The greater effect of ADP accelerating the disappearance of EP suggests that GFP-Spf1 accumulated the E1~P phosphoenzyme. This behavior may reflect a limiting countertransported substrate needed to promote turnover or a missing regulatory factor.

The costs that an organization incurs in producing a product or service can be likened to an iceberg. Some quality costs and expenditures are obvious—like the tip of the iceberg—but many quality costs and expenditures are hidden away like the 90 percent of the iceberg below the surface. These quality costs are sometimes referred to as the “cost of doing business” when, in reality, they are the costs of doing things wrong: The accounting department can measure the dollars into and out of an operation or an organization, but many activities within the operation consume such resources as money, material, labor, and utilities without a definitive control process. One of the leaders in the practice of gathering and using data to improve products and services is an organization's quality group. Because this group interacts with all other departments in the organization to assure quality, it has the unique ability to guide the organization toward the use of the “cost of quality” system to help it optimize profits while meeting its obligations to the communities in which it operates. Developed with the assistance of the controller group, this system can be used to identify costs that affect the quality of the products and services that the organization provides, thus improving the quality and profitability of the organization.

Methane (CH4) emission from boreal, arctic and subarctic wetlands constitutes a potentially positive feedback to global climate warming. Many process-based models have been developed, but high uncertainties remain in estimating the amount of CH4 released from wetlands at the global scale. This study tries to improve estimates of CH4 emissions by up-scaling a wetland CH4 emission model, PEATLAND-VU, to the global scale with a spatial resolution of 0.5 degrees for the period 2001-2006. This up-scaling was based on the global circum-arctic distribution of wetlands with hydrological conditions being specified by a global hydrological model, PCR-GLOBWB. In addition to the daily hydrological output from PCR-GLOBWB, comprising water table depths and snow thickness, the parameterization included air temperature as obtained from the ECMWF Operational Archive. To establish the uncertainty in the representations of the circum-arctic distribution of wetlands on the CH4 emission, several existing products were used to aggregate the emissions. Using the description of potential peatlands from the FAO Digital Soil Map of the World and the representation of floodplains by PCR-GLOBWB, the average annual flux over the period 2001-2006 was estimated to be 78 Tg yr(-1). In comparison, the six-year average CH4 fluxes were 37.7, 89.4, 145.6, and 157.3 Tg yr(-1) for different estimates of wetland extends based on the studies by Matthews and Fung, Prigent et al., Lehner and Doll, and Kaplan, respectively. This study shows the feasibility to estimate interannual variations in CH4 emissions by coupling hydrological and CH4 emission process models. It highlights the importance of an adequate understanding of hydrology in quantifying the total emissions from northern hemispheric wetlands and shows how knowledge of the sub-grid variability in wetland extent helps to prescribe relevant hydrological conditions to the emission model as well as to identify the uncertainty associated with existing wetland distributions. (Less)

8 pages. To be published in the proceedings of the ESO workshop "Science with the VLT in the ELT Era", held in Garching (Germany) on 8-12 October 2007, A. Moorwood editor.; Nowadays, compact sources relatively warm like surfaces of nearby stars, circumstellar environments of stars from early stages to the most evolved ones and surroundings of active galactic nuclei can be investigated at milli-arcsecond scales only with the VLT in its interferometric mode. We propose a spectro-imager, named VSI (VLTI spectro-imager), which is capable to probe these sources both over spatial and spectral scales in the near-infrared domain. This instrument will provide information complementary to what is obtained at the same time with ALMA at different wavelengths and the extreme large telescopes.

International audience; Angiotensin-converting enzyme (ACE) is a metallopeptidase that converts angiotensin I into angiotensin II. ACE is crucial in the control of cardiovascular and renal homeostasis and fertility in mammals. In vertebrates, both transmembrane and soluble ACE, containing one or two active sites, have been characterized. So far, only soluble, single domain ACEs from invertebrates have been cloned, and these have been implicated in reproduction in insects. Furthermore, an ACE-related carboxypeptidase was recently characterized in Leishmania, a unicellular eukaryote, suggesting the existence of ACE in more distant organisms. Interestingly, in silico databank analysis revealed that bacterial DNA sequences could encode putative ACE-like proteins, strikingly similar to vertebrates' enzymes. To gain more insight into the bacterial enzymes, we cloned the putative ACE from the phytopathogenic bacterium, Xanthomonas axonopodis pv. citri, named XcACE. The 2 kb open reading frame encodes a 672-amino-acid soluble protein containing a single active site. In vitro expression and biochemical characterization revealed that XcACE is a functional 72 kDa dipeptidyl-carboxypeptidase. As in mammals, this metalloprotease hydrolyses angiotensin I into angiotensin II. XcACE is sensitive to ACE inhibitors and chloride ions concentration. Variations in the active site residues, highlighted by structural modelling, can account for the different substrate selectivity and inhibition profile compared to human ACE. XcACE characterization demonstrates that ACE is an ancestral enzyme, provoking questions about its appearance and structure/activity specialisation during the course of evolution.

Protoporphyrinogen IX oxidase, a monotopic membrane protein, which catalyzes the oxidation of protoporphyrinogen IX to protoporphyrin IX in the heme/chlorophyll biosynthetic pathway, is distributed widely throughout nature. Here we present the structure of protoporphyrinogen IX oxidase from Myxococcus xanthus, an enzyme with similar catalytic properties to human protoporphyrinogen IX oxidase that also binds the common plant herbicide, acifluorfen. In the native structure, the planar porphyrinogen substrate is mimicked by a Tween 20 molecule, tracing three sides of the macrocycle. In contrast, acifluorfen does not mimic the planarity of the substrate but is accommodated by the shape of the binding pocket and held in place by electrostatic and aromatic interactions. A hydrophobic patch surrounded by positively charged residues suggests the position of the membrane anchor, differing from the one proposed for the tobacco mitochondrial protoporphyrinogen oxidase. Interestingly, there is a discrepancy between the dimerization state of the protein in solution and in the crystal. Conserved structural features are discussed in relation to a number of South African variegate porphyria-causing mutations in the human enzyme.

Human somatic angiotensin I-converting enzyme (sACE) is a key regulator of blood pressure and an important drug target for combating cardiovascular and renal disease. sACE comprises two homologous metallopeptidase domains, N and C, joined by an inter-domain linker. Both domains are capable of cleaving the two hemoregulatory peptides angiotensin I and bradykinin, but differ in their affinities for a range of other substrates and inhibitors. Previously we determined the structure of testis ACE (C domain); here we present the crystal structure of the N domain of sACE (both in the presence and absence of the antihypertensive drug lisinopril) in order to aid the understanding of how these two domains differ in specificity and function. In addition, the structure of most of the inter-domain linker allows us to propose relative domain positions for sACE that may contribute to the domain cooperativity. The structure now provides a platform for the design of "domain-specific" second-generation ACE inhibitors.

139 patients undergoing cardiac surgery were included in a prospective, randomized trial. Patients were randomly allocated to receive cardiopulmonary bypass (CPB) with Trillium Biopassive Surface (TBS Group) coated oxygenators or conventional circuits (control group). 112 patients were studied with respect to postoperative biochemical profile; a subgroup of 27 patients was studied with respect to perioperative complement (C3a) activation. Patients in the TBS group demonstrated a significantly lower white blood cell count at the end of the operation (p=0.036) and a significantly higher platelet count the day after the operation (p=0.023) when compared to the control group. C3a was significantly higher (p=0.02) in the TBS group after 30 minutes of CPB, but the C3a increase after protamine administration was significantly less pronounced in the TBS group vs. the control group. Further studies involving platelet and leukocyte activation are required to better elucidate the action of this new coating in the setting of routine CPB.

The authors report two cases of malignant fibrous histiocytoma localised in the gluteus maximus and re-evaluate some clinical and biological aspects of the neoplasia. Although its histiogenesis is still unsure, the tumour can be classified into various isotopes: the vorticoid-polymorphous variety (70%), and the myxoid, giant cell, angiomatous and inflammatory varieties. It is the most common soft tissue sarcoma in adults and onset is most frequently observed on the trunk and limbs. Biological behaviour shows a marked tendency to local recidivation, with metastatic diffusion occurring mainly late. The choice of therapy consists of more or less radical surgical removal with or without ratio- and immunotherapy. The results of surgery are influenced by the technique used, and the biological and clinical behaviour of the tumour; in view of the numerous case reports of anomalous behaviour, these factors are only indicative. Therapeutic efficacy is on the whole greater in cases of tumours with diameters of less than 5 cm and more superficial localisations compared to the deep muscular fascia.

The treatment of postoperative chronic thoracic fistulas with fibrin glue can be the non-operative ideal solution for the relative simplicity of the execution technique.

The Authors report a case of Poland's syndrome formerly undergone reconstructive surgery with unsatisfactory results. Therefore, a new surgical reconstructive strategy having aesthetic purposes is illustrated.

The Authors report their experience in the application of local anesthesia during breast prosthesis implantation.

We have synthesised poly(3,4-ethylenedioxythiophene), (PEDOT), using FeCl3, Ce(SO4)2 and (NH4)2Ce(NO3) 6 oxidants. Greater than stoichiometric amounts of FeCl3 were required for reasonable yields. PEDOT produced using the eerie-based oxidants contained significant quantities of unidentified cerium compounds. Conductivities as high as 20 Ω−1 cm−1 were obtained. The PEDOT samples were characterised using thermogravimetric analysis and FTIR spectroscopy.

Mn-Zn ferrite prepared by wet methods show high reactivity : pressed samples reach almost theoretical density at temperatures lower than those usually required for sintering powders prepared by common ceramic techniques. They also show a largely different cation site occupancy which evolves with temperature approaching that of ceramic ferrites. Mossbauer spectra on MnFe2O4 also prepared by wet methods confirm such evolution which causes the magnetic moment at 0 K to shift from 4.11 to 4.60 µB as the temperature increases from 25 to 1 350 °C. The temperature dependence of magnetization with increasing Zn content for as prepared samples varies in a different way from that of samples annealed at 1 350 °C and quenched in water. The values of magnetic moments lower than those expected by the normal Neel theory of ferrimagnetism are explained rather well by a certain phenomenological evidence of a Yafet-Kittel effect.

The ideal way to bioassay a mammalian pheromone is to experiment with freely moving animals in a natural setting, and intact social units. The year-round family territories of the North American beaver, Castor canadensis, provide such an opportunity. Being largely nocturnal, beaver have depended on their chemical senses for social communication, food selection, and possibly other behaviors such as orientation in space, and predator detection and avoidance.