Titanium Powder 3D-Printing Technology for a Novel Keratoprosthesis in Alkali-Burned Rabbits.

Purpose: To evaluate the surgical technique, clinical performance, and biocompatibility of a novel keratoprosthesis (KPro) named KPro of Brazil (KoBra) in an alkali-burned rabbit model. Methods: Two-piece three-dimensional-printed titanium powder and polymethyl methacrylate KPros were implanted into 14 alkali-burned corneas of 14 rabbits using an autologous full-thickness corneal graft as the KPro carrier. Rabbits were examined weekly for 12 months to evaluate retention and postoperative complications. Anterior segment optical coherence tomography (AS-OCT) and scanning electron microscopy (SEM) were performed at the end of the experiment to evaluate the relationship between the KoBra and the carrier graft. Results: All surgeries were performed without intraoperative complications, and the immediate postoperative period was uneventful. In 12 eyes (85.7%), the implanted KPros integrated into the operated eyes and maintained clear optics without extrusion or further complications over 12 months. Two eyes presented late postoperative complications that progressed to KPro extrusion: one had a presumed infectious keratitis, and the other had sterile stromal necrosis. AS-OCT demonstrated the correct relationship of the device and carrier graft in all remaining animals at the final follow-up. SEM findings indicate the integration of the porous structure of the back plate into the surrounding tissue. Conclusions: Clinical evaluations, AS-OCT, and SEM findings indicate good biointegr-ation of the implanted device into the corneal carrier graft. KoBra has the advantage of using recipients' own corneas as the prosthesis supporter, and its surgical procedure is relatively simple and safe. Translational Relevance: Titanium three-dimensional-printed technology used in an animal limbal stem-cell deficiency model holds great promise for the treatment of corneal blindness in humans.

Correlation between body composition data obtained by DXA and skinfold predictive protocols in sprinters / Correlação entre dados de composição corporal obtidos pelo DXA e protocolos preditivos de dobras cutâneas em velocistas

Abstract The aim of this study was to describe the correlation between body composition data obtained through DXA and through skinfolds strategy, with some of their respective formulas, in sprinters. The sample consisted of 15 male sprinters (23.81 years ± 3.11; 70.06 Kg ± 4.38; and 179.13 CM ± 5.16) all high performance runners of speed and barriers events (100m, 200m, 400m, 110m with barriers and 400m with barriers). The athletes were submitted to DXA evaluation procedure and to skinfolds collection (triceps, biceps, subscapular, supra iliac, abdominal, medial thigh and calf) and the results were calculated through four distinct equations: Slaughter, Faulkner, Lázari and Boileau. The respective DXA correlations (0.60; 0.81; 0.23 and 0.48) and the equations predicted by skinfold strategy were calculated using Pearson correlation. Among the equations used, Faulkner's was the one presenting highest correlation value when compared to DXA protocol, although all of them aimed to estimate values for BF%.

Resumo O objetivo deste estudo foi descrever a correlação entre dados de composição corporal obtidos através de DEXA, e pela estratégia de dobras cutâneas, com algumas de suas respectivas fórmulas, em velocistas. A amostra foi composta por 15 velocistas do sexo masculino (23,81 anos ± 3,11; 70,06 Kg ± 4,38; e 179,13 cm ± 5,16) todos corredores de alto desempenho das provas de velocidade e barreiras (100m, 200m, 400m, 110m com barreiras e 400m com barreiras). Os atletas foram submetidos ao procedimento de avaliação do DEXA e a coleta de dobras cutâneas (tricipital, bicipital, subescapular, supra ilíaca, abdominal, coxa medial e panturrilha) e os resultados calculados através de quatros distintas equações Slaughter, Faulkner, Lázari e Boileau. As respectivas correlações (0,60; 0,81; 0,23 e 0,48) de DEXA e as equações previstas pela estratégia de dobras cutâneas foram calculadas através da correlação de Pearson. Dentre as equações utilizadas, a de Faulkner foi a que apresentou maior valor de correlação quando comparada ao protocolo do DEXA, apesar de todas terem por objetivo estimar valores para o %G.

Clinical Aspects of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis With Severe Ocular Complications in Brazil.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute and potentially fatal inflammatory vesiculobullous reactions that affect the skin and mucous membranes, and which are most often triggered by particular medications and infections. In Brazil, the drugs most frequently associated with TEN and SJS include cold medicine such as dipyrone and NSAIDs, followed by carbamazepine, phenobarbital, penicillin, and allopurinol. Genetic variations have been found to increase the risk of SJS/TEN in response to triggering factors such as medications. The most closely associated genes found in Brazilian cold-medicine-related SJS/TEN patients with severe ocular complications are HLA-A*66:01 in those of mixed African and European ancestry and HLA-B*44:03 and HLA-C*12:03 in those of solely European ancestry. Our classification system for grading ocular surface complication severity in SJS/TEN patients revealed the most severe complications to be limbal stem cell deficiency and dry eye. Changes to the conjunctival flora have also been observed in SJS/TEN patients. Our group identified bacterial colonization in 95% of the eyes (55.5% of which were gram-positive cocci, 25.5% of which were gram-negative bacilli, and 19% of which were gram-positive bacilli). Several new treatment options in the acute and chronic ocular management of the SJS/TEN patients have been described. This article highlights some Brazilian institutions' contributions to ocular surface care in both the acute phase (including the use of amniotic membrane transplantation) and the chronic phase (such as eyelid margin and fornix reconstruction, minor salivary gland transplantation, amniotic membrane and limbal transplantation, scleral contact lenses, anti-angiogenic eyedrops for corneal neovascularization, ex-vivo cultivated limbal epithelium transplantation, conjunctival-limbal autografting, oral mucosa transplantation, and keratoprosthesis).

Evaluation of wheat flour substitution type (corn, green banana and rice flour) and concentration on local dough properties during bread baking.

Different bread formulations, which provide different dough structures, were studied in order to better understand the effect of wheat flour substitution, flour type and concentration on dough development during baking, and their relationship with physical properties of the final product. Breads were produced with partial substitution of wheat flour by corn (CF), green banana (GF) and rice flour (RF), at different concentrations, and then baked at different times. Wheat flour substitution by CF, GF and RF in bread reduces heat transfer to the dough center by about 21%, 35% and 20%, respectively; and the water loss by about 5%, 15% and 0%, respectively. Those reductions were more influenced by flour type, than flour concentration. When wheat flour is substituted, the mechanisms of water migration are modified, once the pore system of bread dough is more discrete and stiffens later. Calculated thermal conductivity and diffusivity of the different flours used, and its correlations with average composite-bread heating rates (0.93) and water loss (0.85), respectively, indicates that thermal properties of composite bread dough could represent an important issue to be explored in dough systems with reduced gluten concentration.

Clinical characteristics of distal gastric cancer in young adults from Northeastern Brazil.

BACKGROUND: It has been suggested that distal gastric carcinoma (GC) in younger patients has a more aggressive outcome than in older patients, however this is a controversial issue. The aim of this study was to compare clinicopathological features between younger and older patients with GC in Northeastern Brazil. METHODS: A total of 207 patients with distal GC (41 patients ≤45 years, considered younger group, and 166 > 45 years, considered older group) were evaluated prospectively during a 6 year period. RESULTS: The mean patient age in the young group was 37.41 years old and 64.43 years in the older group. No significant difference was found regarding gender, area of residence, history of alcohol consumption, chronic tobacco smoking. Prevalence of first-degree GC history was 12.5% (7.3% in younger group vs. 13.9% in older; p <  0.46). The most frequent symptom was gastric pain and weight loss. Diffuse infiltrative cancer was more frequently seen in younger patients (70.70% vs. 33.70%, respectively; p <  0.01), as was histologically less differentiated tumors (63.40% vs. 33.10%; p <  0.01) and stage IV of GC (48.80% vs. 30.70%; p <  0.015). Five-year survival, evaluated in 82 patients, was lower in younger patients (p = 0.045); however, after adjusting for stage of GC in the multivariate analysis, this association did not remain significant. Family history of GC and gender had no impact on survival. CONCLUSIONS: Younger patients showed higher prevalence of diffuse type of Lauren and lower survival that was attributed to higher rate of advanced stage of GC. Gastric cancer screening strategies should also be considered in younger individuals, especially in areas of high prevalence. Further studies are warranted to determine risk factors associated with gastric cancer in young adults.

Impact of testicular sperm extraction and testicular sperm aspiration on gonadal function in an experimental rat model

ABSTRACT Purpose To assess the impact of sperm retrieval on the gonadal function of rats with impaired spermatogenesis by comparing testicular sperm extraction (TESE) to aspiration (TESA). The efficacy of these procedures to sperm obtainment was also compared. Materials and Methods A pilot study showed impaired spermatogenesis, but normal testosterone (T) production after a bilateral orchidopexy applied to 26 rats, which were randomly assigned into four groups: TESE (n=7), TESA (n=7), SHAM (n=6) and Control (n=6). The T levels were measured through comparative analysis after the orchidopexy. Results There was no statistical difference in the animal's baseline T levels after orchidopexy in comparison to the controls: the TESE and TESA groups, 6.66±4.67ng/mL; the SHAM group (orchidopexy only), 4.99±1.96ng/mL; and the Control, 4.75±1.45ng/mL, p=0.27. Accordingly, no difference was found in the postoperative T levels: TESE, 5.35±4.65ng/mL; TESA, 3.96±0.80ng/mL; SHAM, 3.70±1.27ng/mL; p=0.4. The number of sperm cells found through TESE (41.0±7.0) was significantly larger than that found through TESA (21.3±8.1, p=0.001). Moreover, higher tissue weight was found through TESE (0.09±0.02g versus 0.04±0.04g, p=0.04). Conclusions The testicular sperm capture performed in rats through extraction or aspiration, after orchidopexy, did not significantly decrease the T levels. The amount of sperm found through testicular sperm extraction was higher than that through testicular sperm aspiration.

Impact of testicular sperm extraction and testicular sperm aspiration on gonadal function in an experimental rat model.

PURPOSE: To assess the impact of sperm retrieval on the gonadal function of rats with impaired spermatogenesis by comparing testicular sperm extraction (TESE) to aspiration (TESA). The efficacy of these procedures to sperm obtainment was also compared. MATERIALS AND METHODS: A pilot study showed impaired spermatogenesis, but normal testosterone (T) production after a bilateral orchidopexy applied to 26 rats, which were randomly assigned into four groups: TESE (n=7), TESA (n=7), SHAM (n=6) and Control (n=6). The T levels were measured through comparative analysis after the orchidopexy. RESULTS: There was no statistical difference in the animal's baseline T levels after orchidopexy in comparison to the controls: the TESE and TESA groups, 6.66±4.67ng/mL; the SHAM group (orchidopexy only), 4.99±1.96ng/mL; and the Control, 4.75±1.45ng/ mL, p=0.27. Accordingly, no difference was found in the postoperative T levels: TESE, 5.35±4.65ng/mL; TESA, 3.96±0.80ng/mL; SHAM, 3.70±1.27ng/mL; p=0.4. The number of sperm cells found through TESE (41.0±7.0) was significantly larger than that found through TESA (21.3±8.1, p=0.001). Moreover, higher tissue weight was found through TESE (0.09±0.02g versus 0.04±0.04g, p=0.04). CONCLUSIONS: The testicular sperm capture performed in rats through extraction or aspiration, after orchidopexy, did not significantly decrease the T levels. The amount of sperm found through testicular sperm extraction was higher than that through testicular sperm aspiration.

Characterization of Aliivibrio fischeri strains associated with disease outbreak in brill Scophthalmus rhombus.

Three bacterial isolates were recovered from a disease outbreak with high mortality affecting brill Scophthalmus rhombus (Linnaeus, 1758). Moribund fish showed no external signs of disease, but plentiful haemorrhages were observed in liver. On the basis of phenotypic and genotypic characterization, the isolates were identified as Aliivibrio fischeri. The phenotypic profile of the isolates was basically similar to that of the type strain of this species, although some discrepancies were observed, mainly in the BIOLOG GN profile. The main cellular fatty acids of strain a591 were also consistent with this species. The highest 16S rDNA sequence similarities were recorded with the type strain of A. fischeri (99.07%); other Aliivibrio species showed similarity values below 96%. The highest sequence similarities with gyrB, rpoD and recA genes were also recorded with A. fischeri type strain (99.31, 98.99 and 95.29% similarity, respectively). DNA-DNA hybridization assays confirmed that these isolates belong to A. fischeri; levels of DNA relatedness were 73.5 to 86.2% with isolate a591 (reciprocal values of 86.9 to 99.04%). Finally, a virulence evaluation of the isolates using Senegalese sole fry was also performed; significant mortalities (100% mortality within 5 d) were recorded by intraperitoneal injection, but only with high doses of bacteria (2 × 106 cfu g-1 body weight).

Isolation of Lacinutrix venerupis strains associated with disease outbreaks in sea bream Sparus aurata and European sea bass Dicentrarchus labrax.

Four Gram-negative bacterial isolates were recovered from 2 disease outbreaks that occurred in 2013 affecting European sea bass Dicentrarchus labrax fry and sea bream Sparus aurata adults. Main symptoms were erratic swimming, eroded fins and, in the sea bream outbreak, haemorrhages on the body surface; bacteria were always recovered from internal organs, almost in pure culture. On the basis of phenotypic characterization and 16S rRNA gene sequence analysis, the isolates were identified as Lacinutrix venerupis, a bacterium not previously reported as a fish pathogen. The highest 16S rDNA sequence similarities were recorded with the type strain of this species (99.9-100% similarity), while other species showed similarities below 97%, the closest relative being L. mariniflava (96.3% similarity). Phenotypic characterization showed some discrepancies with the L. venerupis type strain (mainly in BIOLOG GN profile); however, DNA-DNA hybridization assays with L. venerupis and L. mariniflava type strains confirmed that these isolates belong to the former species (levels of DNA relatedness were 98-100% and 38-50%, respectively). Finally, a virulence evaluation of the isolates using Senegalese sole Solea senegalensis fry was also performed; significant mortalities (80-100% mortality within 4 d) were recorded after intraperitoneal injection, but only with high doses of bacteria (107colony forming units fish-1). Further studies will be necessary to determine the importance of this species as a fish pathogen.

Reconstrução torácica com retalhos do músculo reto abdominal e grande dorsal: relato de casos / Chest wall reconstruction using abdominal rectus and latissimus dorsi muscle flaps: case report

INTRODUÇÃO: A reconstrução da parede torácica ainda permanece como um dos grandes desafios da cirurgia plástica reparadora. O presente estudo tem como objetivo apresentar o relato de pacientes submetidos à reconstrução de parede torácica com a utilização de retalhos miocutâneos, após ressecções de parede por tumores/osteomielite. MÉTODOS: Foram incluídos quatro pacientes, três deles portadores de osteomielite e o último apresentando-se com sarcoma, todas as afecções acometendo a parede torácica. Foram submetidos à ressecção de parede e reconstrução com retalhos miocutâneos do grande dorsal (dois casos) e reto abdominal (dois casos). RESULTADOS: Os retalhos utilizados foram suficientes para cobertura cutâneo-muscular e mantiveram boa vitalidade. Em apenas um caso, houve sofrimento parcial do retalho. Não houve recidiva precoce da doença. A estabilidade da caixa torácica foi preservada. CONCLUSÕES: A utilização dos retalhos citados no reparo dos defeitos torácicos mostrou-se satisfatória na intenção de prover revestimento cutâneo e músculo bem vascularizado, este fundamental no combate aos quadros infecciosos locais.

INTRODUCTION: Chest wall reconstruction remains one of the great plastic surgery repair challenges. The present work aims to report on cases of chest wall reconstruction using myocutaneous flaps after wall resection due to tumor/osteomyelitis. METHODS: Four patients were included, among which three presented with osteomyelitis and the other presented with sarcoma; both of these conditions affected the chest wall. Each patient underwent wall resection and reconstruction using myocutaneous flaps from the latissimus dorsi (two cases) and abdominal rectus (two cases). RESULTS: The flaps used were sufficient for skin-muscle covering and maintained good vitality. Partial flap injury occurred in one case. Chest cavity stability was preserved. CONCLUSIONS: The use of the above flaps to repair chest defects was satisfactory with the aim of covering the skin and providing well-vascularized muscles, the latter of which was fundamental to preventing local infection.

Principles and application of LIMS in mouse clinics.

Large-scale systemic mouse phenotyping, as performed by mouse clinics for more than a decade, requires thousands of mice from a multitude of different mutant lines to be bred, individually tracked and subjected to phenotyping procedures according to a standardised schedule. All these efforts are typically organised in overlapping projects, running in parallel. In terms of logistics, data capture, data analysis, result visualisation and reporting, new challenges have emerged from such projects. These challenges could hardly be met with traditional methods such as pen & paper colony management, spreadsheet-based data management and manual data analysis. Hence, different Laboratory Information Management Systems (LIMS) have been developed in mouse clinics to facilitate or even enable mouse and data management in the described order of magnitude. This review shows that general principles of LIMS can be empirically deduced from LIMS used by different mouse clinics, although these have evolved differently. Supported by LIMS descriptions and lessons learned from seven mouse clinics, this review also shows that the unique LIMS environment in a particular facility strongly influences strategic LIMS decisions and LIMS development. As a major conclusion, this review states that there is no universal LIMS for the mouse research domain that fits all requirements. Still, empirically deduced general LIMS principles can serve as a master decision support template, which is provided as a hands-on tool for mouse research facilities looking for a LIMS.

Updates in Rhea--a manually curated resource of biochemical reactions.

Rhea (http://www.ebi.ac.uk/rhea) is a comprehensive and non-redundant resource of expert-curated biochemical reactions described using species from the ChEBI (Chemical Entities of Biological Interest) ontology of small molecules. Rhea has been designed for the functional annotation of enzymes and the description of genome-scale metabolic networks, providing stoichiometrically balanced enzyme-catalyzed reactions (covering the IUBMB Enzyme Nomenclature list and additional reactions), transport reactions and spontaneously occurring reactions. Rhea reactions are extensively curated with links to source literature and are mapped to other publicly available enzyme and pathway databases such as Reactome, BioCyc, KEGG and UniPathway, through manual curation and computational methods. Here we describe developments in Rhea since our last report in the 2012 database issue of Nucleic Acids Research. These include significant growth in the number of Rhea reactions and the inclusion of reactions involving complex macromolecules such as proteins, nucleic acids and other polymers that lie outside the scope of ChEBI. Together these developments will significantly increase the utility of Rhea as a tool for the description, analysis and reconciliation of genome-scale metabolic models.

The Enzyme Portal: a case study in applying user-centred design methods in bioinformatics.

User-centred design (UCD) is a type of user interface design in which the needs and desires of users are taken into account at each stage of the design process for a service or product; often for software applications and websites. Its goal is to facilitate the design of software that is both useful and easy to use. To achieve this, you must characterise users' requirements, design suitable interactions to meet their needs, and test your designs using prototypes and real life scenarios.For bioinformatics, there is little practical information available regarding how to carry out UCD in practice. To address this we describe a complete, multi-stage UCD process used for creating a new bioinformatics resource for integrating enzyme information, called the Enzyme Portal (http://www.ebi.ac.uk/enzymeportal). This freely-available service mines and displays data about proteins with enzymatic activity from public repositories via a single search, and includes biochemical reactions, biological pathways, small molecule chemistry, disease information, 3D protein structures and relevant scientific literature.We employed several UCD techniques, including: persona development, interviews, 'canvas sort' card sorting, user workflows, usability testing and others. Our hope is that this case study will motivate the reader to apply similar UCD approaches to their own software design for bioinformatics. Indeed, we found the benefits included more effective decision-making for design ideas and technologies; enhanced team-working and communication; cost effectiveness; and ultimately a service that more closely meets the needs of our target audience.

BioJS: an open source JavaScript framework for biological data visualization.

SUMMARY: BioJS is an open-source project whose main objective is the visualization of biological data in JavaScript. BioJS provides an easy-to-use consistent framework for bioinformatics application programmers. It follows a community-driven standard specification that includes a collection of components purposely designed to require a very simple configuration and installation. In addition to the programming framework, BioJS provides a centralized repository of components available for reutilization by the bioinformatics community. AVAILABILITY AND IMPLEMENTATION: http://code.google.com/p/biojs/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

The EBI enzyme portal.

The availability of comprehensive information about enzymes plays an important role in answering questions relevant to interdisciplinary fields such as biochemistry, enzymology, biofuels, bioengineering and drug discovery. At the EMBL European Bioinformatics Institute, we have developed an enzyme portal (http://www.ebi.ac.uk/enzymeportal) to provide this wealth of information on enzymes from multiple in-house resources addressing particular data classes: protein sequence and structure, reactions, pathways and small molecules. The fact that these data reside in separate databases makes information discovery cumbersome. The main goal of the portal is to simplify this process for end users.

Modelo prático para treinamento em tenorrafias / Pratical model for tenorrhaphy training

The training of residents in surgical specialties is a challenge, since psychomotor skills are eventually acquired and developed in vivo inthe very first attempt. The simulation techniques through practical models allows the resident's prior training, so that motor skills can be enhanced and evaluated in vivo before surgery. In the context of Plastic Surgery, the repair of tendons, especially flexors, presents technical difficulties during the first attempts of the resident. Objective: The proposed model is designed for practicing tenorraphies, designed to be easy reproducibility and low cost. Methods: We used a simulator using fixed mount, PVC pipe, pig tendons of legs and elastic envisioned to mimic the natural tension exists in the flexor tendons. Results: The model was satisfactory in the intention of allowing the simulation of tenorraphies, due to the similarities between human and pig tendons, and conferred by the elastic tension. Conclusions: The model provided adequate training of motor skills in tendo sutures. This is an interesting option to be used in the early learning curve...

O treinamento dos residentes de especialidades cirúrgicas representa um desafio, uma vez que as habilidades psicomotoras são, eventualmente, adquiridas e desenvolvidas in vivo já nas primeiras tentativas. A simulação das técnicas com o uso de modelos práticos permite o treinamento prévio do residente, de forma que as habilidades motoras possam ser incrementadas e avaliadas antes da cirurgia in vivo. No âmbito da Cirurgia Plástica, o reparo de tendões, em especial dos flexores, apresenta dificuldades técnicas durante as primeiras tentativas do residente. Objetivo: O modelo proposto foi idealizado para a prática de tenorrafias, idealizado para ser de fácil reprodutividade e baixo custo. Método: Foi utilizado um simulador de tenorrafias utilizando suporte fixo, tubos de PVC, tendões de patas de suínos e elásticos idealizados para imitar a tensão natural existente nos tendões flexores. Resultados: O modelo utilizado mostrou-se satisfatório na intenção de permitir a simulação de tenorradias, devido às semelhanças entre tendões humanos e suínos, além da tensão conferida pelos elásticos. Conclusões: O modelo proporcionou adequado treinamento de habilidades motoras nas suturas tendinosas . Trata-se de uma opção interessante a ser utilizada no início da curva de aprendizado...

Rhea--a manually curated resource of biochemical reactions.

Rhea (http://www.ebi.ac.uk/rhea) is a comprehensive resource of expert-curated biochemical reactions. Rhea provides a non-redundant set of chemical transformations for use in a broad spectrum of applications, including metabolic network reconstruction and pathway inference. Rhea includes enzyme-catalyzed reactions (covering the IUBMB Enzyme Nomenclature list), transport reactions and spontaneously occurring reactions. Rhea reactions are described using chemical species from the Chemical Entities of Biological Interest ontology (ChEBI) and are stoichiometrically balanced for mass and charge. They are extensively manually curated with links to source literature and other public resources on metabolism including enzyme and pathway databases. This cross-referencing facilitates the mapping and reconciliation of common reactions and compounds between distinct resources, which is a common first step in the reconstruction of genome scale metabolic networks and models.

Chemical Entities of Biological Interest: an update.

Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on 'small' chemical compounds. The molecular entities in question are either natural products or synthetic products used to intervene in the processes of living organisms. Genome-encoded macromolecules (nucleic acids, proteins and peptides derived from proteins by cleavage) are not as a rule included in ChEBI. In addition to molecular entities, ChEBI contains groups (parts of molecular entities) and classes of entities. ChEBI includes an ontological classification, whereby the relationships between molecular entities or classes of entities and their parents and/or children are specified. ChEBI is available online at http://www.ebi.ac.uk/chebi/. This article reports on new features in ChEBI since the last NAR report in 2007, including substructure and similarity searching, a submission tool for authoring of ChEBI datasets by the community and a 30-fold increase in the number of chemical structures stored in ChEBI.

ChEBI: a database and ontology for chemical entities of biological interest.

Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on 'small' chemical compounds. The molecular entities in question are either natural products or synthetic products used to intervene in the processes of living organisms. Genome-encoded macromolecules (nucleic acids, proteins and peptides derived from proteins by cleavage) are not as a rule included in ChEBI. In addition to molecular entities, ChEBI contains groups (parts of molecular entities) and classes of entities. ChEBI includes an ontological classification, whereby the relationships between molecular entities or classes of entities and their parents and/or children are specified. ChEBI is available online at http://www.ebi.ac.uk/chebi/