Chlamydomonas reinhardtii and Microbacterium forte sp. nov., a mutualistic association that favors sustainable hydrogen production.

A naturally occurring multispecies bacterial community composed of Bacillus cereus and two novel bacteria (Microbacterium forte sp. nov. and Stenotrophomonas goyi sp. nov.) has been identified from a contaminated culture of the microalga Chlamydomonas reinhardtii. When incubated in mannitol- and yeast extract-containing medium, this bacterial community can promote and sustain algal hydrogen production up to 313 mL H2·L-1 for 17 days and 163.5 mL H2·L-1 for 25 days in high-cell (76.7 µg·mL-1 of initial chlorophyll) and low-cell density (10 µg·mL-1 of initial chlorophyll) algal cultures, respectively. In low-cell density algal cultures, hydrogen production was compatible with algal growth (reaching up to 60 µg·mL-1 of chlorophyll). Among the bacterial community, M. forte sp. nov. was the sole responsible for the improvement in hydrogen production. However, algal growth was not observed in the Chlamydomonas-M. forte sp. nov. consortium during hydrogen-producing conditions (hypoxia), suggesting that the presence of B. cereus and S. goyi sp. nov. could be crucial to support the algal growth during hypoxia. Still, under non­hydrogen producing conditions (aerobiosis) the Chlamydomonas-M. forte sp. nov. consortium allowed algal growth (up to 40 µg·mL-1 of chlorophyll) and long-term algal viability (>45 days). The genome sequence and growth tests of M. forte sp. nov. have revealed that this bacterium is auxotroph for biotin and thiamine and unable to use sulfate as sulfur source; it requires S-reduced forms such as cysteine and methionine. Cocultures of Chlamydomonas reinhardtii and M. forte sp. nov. established a mutualistic association: the alga complemented the nutrient deficiencies of the bacterium, while the bacterium released ammonium (0.19 mM·day-1) and acetic acid (0.15 mM·day-1) for the alga. This work offers a promising avenue for photohydrogen production concomitant with algal biomass generation using nutrients not suitable for mixotrophic algal growth.

Stenotrophomonas goyi sp. nov., a novel bacterium associated with the alga Chlamydomonas reinhardtii.

Background: A culture of the green algae Chlamydomonas reinhardtii was accidentally contaminated with three different bacteria in our laboratory facilities. This contaminated alga culture showed increased algal biohydrogen production. These three bacteria were independently isolated. Methods: The chromosomic DNA of one of the isolated bacteria was extracted and sequenced using PacBio technology. Tentative genome annotation (RAST server) and phylogenetic trees analysis (TYGS server) were conducted. Diverse growth tests were assayed for the bacterium and for the alga-bacterium consortium. Results: Phylogenetic analysis indicates that the bacterium is a novel member of the Stenotrophomonas genus that has been termed in this work as S. goyi sp. nov. A fully sequenced genome (4,487,389 base pairs) and its tentative annotation (4,147 genes) are provided. The genome information suggests that S. goyi sp. nov. is unable to use sulfate and nitrate as sulfur and nitrogen sources, respectively. Growth tests have confirmed the dependence on the sulfur-containing amino acids methionine and cysteine. S. goyi sp. nov. and Chlamydomonas reinhardtii can establish a mutualistic relationship when cocultured together. Conclusions: S. goyi sp. nov. could be of interest for the design of biotechnological approaches based on the use of artificial microalgae-bacteria multispecies consortia that take advantage of the complementary metabolic capacities of their different microorganisms.

Coristoma óseo lingual. Nuevo caso de una entidad extremadamente infrecuente / Lingual osseous choristoma. New case of an extremely uncommon entity

Los osteomas constituyen un grupo de tumores óseos benignos que se localizan habitualmente en el cráneo y los huesos de la región facial, siendo rara su presencia en los tejidos blandos de la cavidad oral. También se les conoce como coristomas óseos, ya que están compuestos por tejido óseo maduro de aspecto normal. En la cavidad oral, la localización más frecuente es el tercio posterior de la lengua y suele aparecer en mujeres con edades comprendidas entre la segunda y tercera década de vida. A pesar de que la mayoría de los pacientes presentan un curso asintomático, no es infrecuente que su motivo de consulta sea la sensación de cuerpo extraño y disfagia. Afortunadamente, los osteomas linguales tienen buen pronóstico, ya que una vez realizada la extirpación no hay descritos casos de recurrencia. Debido a su insólita presentación, con menos de 100 casos publicados en la literatura, se decide presentar este caso clínico. (AU)

Osteomas are rare benign tumors that can be located on the craniomaxillofacial skeleton, being unusual its presence in the soft tissues of the oral cavity. They are also known as osseous choristomas, as they consist of normal matured bone tissue. Osteomas of the tongue occur more frequently in women in their second or third decade and the most frequent location in the oral cavity is the posterior third of the tongue. Most patients are asymptomatic, though other forms of presentation could be complaining of the sensation of having a foreign body or, even, dysphagia. The fact that less than 100 cases have been reported in the literature, has motivated the presentation of this clinical case. (AU)

Chlamydomonas-Methylobacterium oryzae cooperation leads to increased biomass, nitrogen removal and hydrogen production.

In the context of algal wastewater bioremediation, this study has identified a novel consortium formed by the bacterium Methylobacterium oryzae and the microalga Chlamydomonas reinhardtii that greatly increase biomass generation (1.22 g L-1·d-1), inorganic nitrogen removal (>99%), and hydrogen production (33 mL·L-1) when incubated in media containing ethanol and methanol. The key metabolic aspect of this relationship relied on the bacterial oxidation of ethanol to acetate, which supported heterotrophic algal growth. However, in the bacterial monocultures the acetate accumulation inhibited bacterial growth. Moreover, in the absence of methanol, ethanol was an unsuitable carbon source and its incomplete oxidation to acetaldehyde had a toxic effect on both the alga and the bacterium. In cocultures, both alcohols were used as carbon sources by the bacteria, the inhibitory effects were overcome and both microorganisms mutually benefited. Potential biotechnological applications in wastewater treatment, biomass generation and hydrogen production are discussed.

¿Es el desplazamiento discal sinónimo de patología articular temporomandibular? Correlación clínico-radiológica y prevalencia de trastornos internos en sujetos voluntarios asintomáticos / Is disc displacement synonymous with temporomandibular joint pathology? Clinical-radiological correlation and prevalence of internal disorders in asymptomatic volunteers subjects

INTRODUCCIÓN: Los trastornos internos (TI) de la articulación temporomandibular (ATM) constituyen la condición clínica articular más frecuente en pacientes con trastornos temporomandibulares (TTM). Presentes hasta en un 80-90 % de los casos sintomáticos, no se sabe por qué, su presencia en sujetos asintomáticos no causa dolor ni disfunción. En contraposición, una posición normal del disco ha sido descrita en un 16-23 % de pacientes sintomáticos. OBJETIVOS: Analizar la prevalencia de TI de la ATM en sujetos voluntarios asintomáticos y qué características clínico-radiológicas podrían favorecer su presencia o desarrollo. MATERIAL Y MÉTODO: Se diseñó un estudio descriptivo, observacional, transversal. Se seleccionaron 43 sujetos de una población de 253 residentes que realizaban su formación médica especializada. El estudio fue desarrollado en varias fases. Fase I: Anamnesis y examen clínico. Empleo del índice craneomandibular de Fricton (ICM); Fase II: Adquisición y evaluación de imágenes de Resonancia Magnética (RMN). Las imágenes fueron procesadas a formato DICOM 4.0 y evaluadas por dos examinadores externos. Fase III: Análisis morfoestructural de las ATM. Las imágenes de RMN fueron analizadas empleando el programa informático Osirix® V 3.5.1. RESULTADOS: Setenta y dos articulaciones (pertenecientes a 36 sujetos) fueron finalmente analizadas. La edad media fue de 28,39 ± 3,70 años con una distribución por sexos de 47,2 % hombres y de 52,8 % mujeres. El análisis inferencial mostró resultados estadísticamente significativos en relación con las variables sexo (p = 0,021), chasquido articular (p = 0,007), valor del ICM (p = 0,000296), morfología discal (p = 1,032 X 10-8), morfología condilar (p = 2,116 X 10-8), posición condilar en el interior de la ATM (longitudes posterior y superior, p = 5,385 X 10-9; p = 0,000245, respectivamente) y morfología de la fosa articular (p = 0,024). CONCLUSIONES: Existe una elevada prevalencia de TI de la ATM en los sujetos asintomáticos analizados. Ciertos criterios clínicos (chasquido articular) y radiológicos (morfología discal alargada/doblada, cóndilo y fosa aplanados y posición más posterior y craneal del cóndilo mandibular) podrían ser considerados como predictores o relacionados con la presencia de desplazamiento discal. El ICM podría constituir una herramienta útil en el diagnóstico de patología articular de la ATM

INTRODUCTION: Internal derangements (IDs) of the temporomandibular joint (TMJ) constitute the most common clinical joint condition in patients with temporomandibular disorders (TMDs). Present in up to 80-90 % of symptomatic cases, it is not known why, its presence in asymptomatic subjects does not cause pain or dysfunction. In contrast, a normal position of the disc has been described in 16-23 % of symptomatic patients. OBJECTIVES: To analyze the prevalence of IDs of the TMJ in asymptomatic voluntary subjects and what clinical-radiological characteristics could favor their presence or development. MATERIAL AND METHODS: A descriptive, observational, cross-sectional study was designed. Fortythree subjects from a population of 253 residents who performed their training program were selected. The study was carried out in several phases. Phase I: Anamnesis and clinical examination. Use of the Fricton Cranio-mandibular Index (CMI); Phase II: Acquisition and evaluation of Magnetic Resonance Imaging (MRI). The images were processed in DICOM 4.0 format and evaluated by two external examiners. Phase III: Morpho-structural analysis of the TMJs. The MRI were analyzed using the Osirix® V 3.5.1 Software. RESULTS: Seventy-two joints (belonging to 36 subjects) were finally analyzed. The mean age was 28.39 ± 3.70 years with a distribution by sex of 47.2% men and 52.8 % women. The inferential analysis showed statistically significant results in relation to the variables sex (p = 0.021), joint click (p = 0.007), CMI value (p = 0.000296), disc morphology (p = 1.032x10-8), condylar morphology (p = 2.116x10-8) and condylar position inside the TMJ ((posterior and superior lengths, p = 5.385x10-9; p = 0.000245, respectively) and morphology of the joint fossa (p = 0.024). CONCLUSIONS: A high prevalence of IDs in asymptomatic subjects is present in our study. Certain clinical (joint clicking) and radiological criteria (an elongated or bent disc morphology, a flattened condyle and fossa and a more posterior and cranial position of the mandibular condyle) could be considered as predictors or be related to the presence of disc displacement. The CMI could be a useful tool in the diagnosis of joint pathology of the TMJ

Algae-Bacteria Consortia as a Strategy to Enhance H2 Production.

Biological hydrogen production by microalgae is a potential sustainable, renewable and clean source of energy. However, many barriers limiting photohydrogen production in these microorganisms remain unsolved. In order to explore this potential and make biohydrogen industrially affordable, the unicellular microalga Chlamydomonas reinhardtii is used as a model system to solve barriers and identify new approaches that can improve hydrogen production. Recently, Chlamydomonas-bacteria consortia have opened a new window to improve biohydrogen production. In this study, we review the different consortia that have been successfully employed and analyze the factors that could be behind the improved H2 production.

Long-Term Dislocation of the Mandible: Is there an Algorithm to Success? Intraoperative Decision and Review of Literature.

PURPOSE: Long-term TMJ dislocation is a rare condition. It occurs when an acute luxation remains untreated in time. METHODS: A 52-year-old man presented with a long-term TMJ luxation in the context of Steinert's disease. A discectomy together with condylectomy and eminectomy was performed, obtaining an adequate reduction of the luxated condyle and disc. RESULTS: Twelve months after the operation, the condition has not recurred at all. A stable and centred occlusion was checked; his MIO was over 30 mm. CONCLUSION: The combination of these three techniques could be a good option in cases of Steinert's myotonia, where the condyle luxation becomes chronic and irreducible due to the altered neuromuscular condition. There is still no consensus regarding the treatment for long-term TMJ dislocations. New and more solid studies may be needed in order to find adequate treatment protocols for this condition.

Ferredoxin5 Deletion Affects Metabolism of Algae during the Different Phases of Sulfur Deprivation.

Ferredoxin5 (FDX5), a minor ferredoxin protein in the alga Chlamydomonas (Chlamydomonas reinhardtii), helps maintain thylakoid membrane integrity in the dark. Sulfur (S) deprivation has been used to achieve prolonged hydrogen production in green algae. Here, we propose that FDX5 is involved in algal responses to S-deprivation as well as to the dark. Specifically, we tested the role of FDX5 in both the initial aerobic and subsequent anaerobic phases of S-deprivation. Under S-deprived conditions, absence of FDX5 causes a distinct delay in achieving anoxia by affecting photosynthetic O2 evolution, accompanied by reduced acetate uptake, lower starch accumulation, and delayed/lower fermentative metabolite production, including photohydrogen. We attribute these differences to transcriptional and/or posttranslational regulation of acetyl-CoA synthetase and ADP-Glc pyrophosphorylase, and increased stability of the PSII D1 protein. Interestingly, increased levels of FDX2 and FDX1 were observed in the mutant under oxic, S-replete conditions, strengthening our previously proposed hypothesis that other ferredoxins compensate in response to a lack of FDX5. Taken together, the results of our omics and pull-down experiments confirmed biochemical and physiological results, suggesting that FDX5 may have other effects on Chlamydomonas metabolism through its interaction with multiple redox partners.

Acetic acid is key for synergetic hydrogen production in Chlamydomonas-bacteria co-cultures.

This study is a proof of concept for the synergetic biohydrogen production in alga-bacteria co-cultures. Algal hydrogen photoproduction was obtained in sugar-containing media only when the green alga Chlamydomonas reinhardtii was co-cultured with Pseudomonas putida (40.8 ml H2·L-1), Escherichia coli (35.1 ml H2·L-1) and Rhizobium etli (16.1 ml H2·L-1). Hydrogen photo-production in these co-cultures was not only linked to the induction of hypoxia, but to the ability of the bacteria to produce acetic acid from sugars. Synergetic hydrogen production was achieved by integrating the photobiological and fermentative production in Chlamydomonas and Escherichia coli co-cultures supplemented with glucose, which resulted in 60% more H2 production than the sum of the respective monocultures. This cooperation relied on the ability of the alga to consume the excreted bacterial acetic acid, which benefited both bacterial and algal hydrogen production. This knowledge may open new possibilities for the biohydrogen production from industrial wastes.

Arginine is a component of the ammonium-CYG56 signalling cascade that represses genes of the nitrogen assimilation pathway in Chlamydomonas reinhardtii.

Nitrogen assimilation and metabolism are essential processes for all living organisms, yet there is still much to be learnt on how they are regulated. The use of Chlamydomonas reinhardtii as a model system has been instrumental not only in identifying conserved regulation mechanisms that control the nitrogen assimilation pathway, but also in understanding how the intracellular nitrogen status regulates metabolic processes of industrial interest such as the synthesis of biolipids. While the genetic regulators that control the nitrogen pathway are successfully being unravelled, other layers of regulation have received less attention. Amino acids, for example, regulate nitrogen assimilation in certain organisms, but their role in Chlamydomonas has not thoroughly been explored. Previous results had suggested that arginine might repress key genes of the nitrogen assimilation pathway by acting within the ammonium negative signalling cascade, upstream of the nitric oxide (NO) inducible guanylate cyclase CYG56. We tested this hypothesis with a combination of genetic and chemical approaches. Antagonising the effects of arginine with an arginine biosynthesis mutant or with two chemical analogues released gene expression from ammonium mediated repression. The cyg56 and related non1 mutants, which are partially insensitive to ammonium repression, were also partially insensitive to repression by arginine. Finally, we show that the addition of arginine to the medium leads to an increase in intracellular NO. Our data reveal that arginine acts as a negative signal for the assimilation of nitrogen within the ammonium-CYG56 negative signalling cascade, and provide a connection between amino acid metabolism and nitrogen assimilation in microalgae.

H2 production pathways in nutrient-replete mixotrophic Chlamydomonas cultures under low light. Response to the commentary article "On the pathways feeding the H2 production process in nutrient-replete, hypoxic conditions," by Alberto Scoma and Szilvia Z. Tóth.

BACKGROUND: A recent Commentary article entitled "On the pathways feeding the H2 production process in nutrient-replete, hypoxic conditions" by Dr. Scoma and Dr. Tóth, Biotechnology for Biofuels (2017), opened a very interesting debate about the H2 production photosynthetic-linked pathways occurring in Chlamydomonas cultures grown in acetate-containing media and incubated under hypoxia/anoxia conditions. This Commentary article mainly focused on the results of our previous article "Low oxygen levels contribute to improve photohydrogen production in mixotrophic non-stressed Chlamydomonas cultures," by Jurado-Oller et al., Biotechnology for Biofuels (7, 2015; 8:149). MAIN BODY: Here, we review some previous knowledge about the H2 production pathways linked to photosynthesis in Chlamydomonas, especially focusing on the role of the PSII-dependent and -independent pathways in acetate-containing nutrient-replete cultures. The potential contributions of these pathways to H2 production under anoxia/hypoxia are discussed. CONCLUSION: Despite the fact that the PSII inhibitor DCMU is broadly used to discern between the two different photosynthetic pathways operating under H2 production conditions, its use may lead to distinctive conclusions depending on the growth conditions. The different potential sources of reductive power needed for the PSII-independent H2 production in mixotrophic nutrient-replete cultures are a matter of debate and conclusive evidences are still missing.

Glucose Uptake in Prochlorococcus: Diversity of Kinetics and Effects on the Metabolism.

We have previously shown that Prochlorococcus sp. SS120 strain takes up glucose by using a multiphasic transporter encoded by the Pro1404 gene. Here, we studied the glucose uptake kinetics in multiple Prochlorococcus strains from different ecotypes, observing diverse values for the Ks constants (15-126.60 nM) and the uptake rates (0.48-6.36 pmol min-1 mg prot-1). Multiphasic kinetics was observed in all studied strains, except for TAK9803-2. Pro1404 gene expression studies during the 21st Atlantic Meridional Transect cruise showed positive correlation with glucose concentrations in the ocean. This suggests that the Pro1404 transporter has been subjected to diversification along the Prochlorococcus evolution, in a process probably driven by the glucose availabilities at the different niches it inhabits. The glucose uptake mechanism seems to be a primary transporter. Glucose addition induced detectable transcriptomic and proteomic changes in Prochlorococcus SS120, but photosynthetic efficiency was unaffected. Our studies indicate that glucose is actively taken up by Prochlorococcus, but its uptake does not significantly alter the trophic ways of this cyanobacterium, which continues performing photosynthesis. Therefore Prochlorococcus seems to remain acting as a fundamentally phototrophic organism, capable of using glucose as an extra resource of carbon and energy when available in the environment.

What is the role of elective neck dissection in patients with squamous cell carcinoma of the upper jaw? / ¿Cual es el papel de la disección cervical electiva en el carcinoma escamoso del maxilar superior?

Background. Surgical treatment of clinically negative neck in maxillary squamous cell carcinoma (SCC) of the upper jaw is controversial. The purpose of this study was to define the incidence of cervical metastasis and to assess if elective neck dissection is justified when the neck is not primarily affected. Methods. We retrospectively reviewed 20 patients treated of SCC of the maxillary alveolus and hard palate between 2005 and 2012. Results. Six (30%) patients presented with cervical lymph metastasis at initial diagnosis. Two of the14 patients who initially had no signs of metastasis in the neck developed cervical metastasis during follow-up and another patient with cervical metastasis at diagnosis developed contralateral cervical metastasis. All the patients with cervical metastasis (45%) were pT3/T4 SCC. Cervical metastasis developed at a mean of 11.6 months. Conclusions. Despite this study being limited by its retrospective nature and the sample size, based on our findings and on an extensive review of the literature, we may conclude that cervical metastasis from maxillary alveolus and hard palate SCC appears most frequently in pT3/T4 tumors. Therefore, we find elective neck dissection appropriate for patients with pT3/T4 SCC of the upper jaw (AU)

Introducción. El tratamiento quirúrgico del cuello clínicamente negativo en el carcinoma de células escamosas (CCE) del maxilar superior es controvertido. El objetivo de este estudio es mostrar la incidencia de metástasis cervical y analizar si la disección cervical electiva está justificada cuando el cuello no está afectado de inicio. Métodos. Revisamos retrospectivamente 20 pacientes tratados por CCE de paladar duro y reborde alveolar superior entre 2005 y 2012. Resultados. Seis (30%) pacientes presentaron metástasis cervical de inicio. Dos de los 14 pacientes que inicialmente no tuvieron signos de metástasis cervical la desarrollaron durante el seguimiento, y otro paciente con metástasis cervical al inicio desarrolló una metástasis cervical contralateral. Todos los pacientes con metástasis cervical (45%) fueron pT3/T4 CCE. El tiempo medio de aparición de metástasis cervical fue de 11,6 meses. Conclusiones. A pesar de las limitaciones de este estudio (naturaleza retrospectiva, limitado número de pacientes), y tras analizar los resultados obtenidos y revisar la literatura, podemos concluir que la metástasis cervical de CCE de maxilar superior aparece con mayor incidencia en tumores pT3/T4. Por lo tanto, creemos conveniente realizar disección cervical electiva en pacientes con CCE T3/T4 de maxilar superior (AU)

Low oxygen levels contribute to improve photohydrogen production in mixotrophic non-stressed Chlamydomonas cultures.

BACKGROUND: Currently, hydrogen fuel is derived mainly from fossil fuels, but there is an increasing interest in clean and sustainable technologies for hydrogen production. In this context, the ability of some photosynthetic microorganisms, particularly cyanobacteria and microalgae, to produce hydrogen is a promising alternative for renewable, clean-energy production. Among a diverse array of photosynthetic microorganisms able to produce hydrogen, the green algae Chlamydomonas reinhardtii is the model organism widely used to study hydrogen production. Despite the well-known fact that acetate-containing medium enhances hydrogen production in this algae, little is known about the precise role of acetate during this process. RESULTS: We have examined several physiological aspects related to acetate assimilation in the context of hydrogen production metabolism. Measurements of oxygen and CO2 levels, acetate uptake, and cell growth were performed under different light conditions, and oxygenic regimes. We show that oxygen and light intensity levels control acetate assimilation and modulate hydrogen production. We also demonstrate that the determination of the contribution of the PSII-dependent hydrogen production pathway in mixotrophic cultures, using the photosynthetic inhibitor DCMU, can lead to dissimilar results when used under various oxygenic regimes. The level of inhibition of DCMU in hydrogen production under low light seems to be linked to the acetate uptake rates. Moreover, we highlight the importance of releasing the hydrogen partial pressure to avoid an inherent inhibitory factor on the hydrogen production. CONCLUSION: Low levels of oxygen allow for low acetate uptake rates, and paradoxically, lead to efficient and sustained production of hydrogen. Our data suggest that acetate plays an important role in the hydrogen production process, during non-stressed conditions, other than establishing anaerobiosis, and independent of starch accumulation. Potential metabolic pathways involved in hydrogen production in mixotrophic cultures are discussed. Mixotrophic nutrient-replete cultures under low light are shown to be an alternative for the simultaneous production of hydrogen and biomass.

Melanoma mucoso en una localización extremadamente infrecuente: la base de lengua. A propósito de un caso y revisión de la literatura / Mucosal melanoma in an extremely rare location: base of the tongue. A case presentation and literature review

El melanoma primario en la cavidad oral es una neoplasia rara, especialmente en la lengua. Presentamos un caso de melanoma mucoso en la base de la lengua, una localización extremadamente infrecuente (en la literatura médica tan solo se han aportado unos 30 casos). El estudio de extensión no reveló lesiones metastásicas a distancia. El paciente fue tratado mediante glosectomía subtotal y vaciamiento cervical funcional bilateral. La lengua es una de las estructuras más difíciles de reconstruir, debido a su papel central en la fonación, la deglución y la protección de las vías respiratorias El defecto fue reconstruido con colgajo libre microvascularizado anterolateral de muslo. El tratamiento quirúrgico se complementó con radioterapia e inmunoterapia adyuvantes. El postoperatorio se desarrolló sin complicaciones. En la actualidad, 13 meses después de la cirugía, el paciente se encuentra asintomático, no hay evidencia de recidiva de la enfermedad y no tiene ninguna dificultad en la deglución ni fonación (AU)

Primary malignant melanoma of the oral cavity is a rare neoplasm, especially on the tongue. We report a case of mucosal melanoma at the base of the tongue, an extremely rare location (only about 30 cases have been reported in the literature). The extension study did not reveal any distant metastatic lesions. The patient was treated by sub-total glossectomy and bilateral functional neck dissection. The tongue is one of the most difficult structures to reconstruct, because of its central role in phonation, swallowing, and airway protection. The defect was reconstructed with an anterolateral thigh free flap. Surgical treatment was supplemented with adjuvant radiotherapy and immunotherapy. The post-operative period was uneventful. At present, 13 months after surgery, patient is asymptomatic, with no evidence of recurrence of melanoma and has no difficulty in swallowing or phonation (AU)

Relevance of nutrient media composition for hydrogen production in Chlamydomonas.

Microalgae are capable of biological H2 photoproduction from water, solar energy, and a variety of organic substrates. Acclimation responses to different nutrient regimes finely control photosynthetic activity and can influence H2 production. Hence, nutrient stresses are an interesting scenario to study H2 production in photosynthetic organisms. In this review, we mainly focus on the H2-production mechanisms in Chlamydomonas reinhardtii and the physiological relevance of the nutrient media composition when producing H2.

¿Cuál es su diagnóstico y cual sería su tratamiento / What is your diagnosis and what would your treatment be?

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Tumor fibroso solitario de cavidad oral. Confirmación histológica final ante la sospecha de lipoma facial / Solitary fibrous tumor of the oral cavity. Final histologic confirmation after suspected facial lipoma

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Idoneidad del colgajo anterolateral de muslo para reconstrucción de grandes defectos craneofaciales / Suitability of the anterolateral thigh free flap for reconstruction of large craniofacial defects

La reconstrucción de grandes defectos en la región craneal y del cuero cabelludo constituyen un reto para el cirujano reconstructivo. Diversos factores pueden influir en la selección de un determinado método quirúrgico, tales como: anatomía del defecto, factores dependientes del paciente, preferencias del cirujano, etc. En condiciones desfavorables, tales como grandes defectos, presencia de infección o cirugías previas, los colgajos microvascularizados se presentan superiores al resto de técnicas reconstructivas en la recuperación de la integridad craneofacial. Presentamos un varón de 57 años de edad con defecto estético importante en región frontal e infección crónica activa de más de 20 años de evolución reconstruido con un colgajo libre microvascularizado de la región antero-lateral del muslo de una forma dual, solucionando con ello el cuadro infeccioso al aportar tejido sano vascularizado; y el defecto estético al añadir volumen, consiguiéndose un excelente resultado final (AU)

Reconstruction of large defects in the skull and scalp are a challenge for reconstructive surgeon. Several factors can influence the selection of a particular surgical method: anatomy of the defect, patient-dependent factors, surgeon preferences, etc. In unfavorable conditions such as large defects, presence of infection or previous surgery, microvascularized free flaps are considered superior to other reconstructive techniques in the recovery of craniofacial integrity. We present a male of 57 years with a major cosmetic defect on the forehead and active chronic infection of over 20 years onset reconstructed with a microvascular dual free flaps of the antero-lateral thigh, solving the infectious process with the use of healthy vascularized tissue, and the aesthetic defect by adding volume, achieving an excellent result (AU)