A Randomized, Double-Blind, Phase 3 Safety and Efficacy Study of Ridinilazole Versus Vancomycin for Treatment of Clostridioides difficile Infection: Clinical Outcomes With Microbiome and Metabolome Correlates of Response.

BACKGROUND: Exposure to antibiotics predisposes to dysbiosis and Clostridioides difficile infection (CDI) that can be severe, recurrent (rCDI), and life-threatening. Nonselective drugs that treat CDI and perpetuate dysbiosis are associated with rCDI, in part due to loss of microbiome-derived secondary bile acid (SBA) production. Ridinilazole is a highly selective drug designed to treat CDI and prevent rCDI. METHODS: In this phase 3 superiority trial, adults with CDI, confirmed with a stool toxin test, were randomized to receive 10 days of ridinilazole (200 mg twice daily) or vancomycin (125 mg 4 times daily). The primary endpoint was sustained clinical response (SCR), defined as clinical response and no rCDI through 30 days after end of treatment. Secondary endpoints included rCDI and change in relative abundance of SBAs. RESULTS: Ridinilazole and vancomycin achieved an SCR rate of 73% versus 70.7%, respectively, a treatment difference of 2.2% (95% CI: -4.2%, 8.6%). Ridinilazole resulted in a 53% reduction in recurrence compared with vancomycin (8.1% vs 17.3%; 95% CI: -14.1%, -4.5%; P = .0002). Subgroup analyses revealed consistent ridinilazole benefit for reduction in rCDI across subgroups. Ridinilazole preserved microbiota diversity, increased SBAs, and did not increase the resistome. Conversely, vancomycin worsened CDI-associated dysbiosis, decreased SBAs, increased Proteobacteria abundance (∼3.5-fold), and increased the resistome. CONCLUSIONS: Although ridinilazole did not meet superiority in SCR, ridinilazole greatly reduced rCDI and preserved microbiome diversity and SBAs compared with vancomycin. These findings suggest that treatment of CDI with ridinilazole results in an earlier recovery of gut microbiome health. Clinical Trials Registration.Ri-CoDIFy 1 and 2: NCT03595553 and NCT03595566.

Parkinson's disease-derived α-synuclein assemblies combined with chronic-type inflammatory cues promote a neurotoxic microglial phenotype.

Parkinson's disease (PD) is a common age-related neurodegenerative disorder characterized by the aggregation of α-Synuclein (αSYN) building up intraneuronal inclusions termed Lewy pathology. Mounting evidence suggests that neuron-released αSYN aggregates could be central to microglial activation, which in turn mounts and orchestrates neuroinflammatory processes potentially harmful to neurons. Therefore, understanding the mechanisms that drive microglial cell activation, polarization and function in PD might have important therapeutic implications. Here, using primary microglia, we investigated the inflammatory potential of pure αSYN fibrils derived from PD patients. We further explored and characterized microglial cell responses to a chronic-type inflammatory stimulation combining PD patient-derived αSYN fibrils (FPD), Tumor necrosis factor-α (TNFα) and prostaglandin E2 (PGE2) (TPFPD). We showed that FPD hold stronger inflammatory potency than pure αSYN fibrils generated de novo. When combined with TNFα and PGE2, FPD polarizes microglia toward a particular functional phenotype departing from FPD-treated cells and featuring lower inflammatory cytokine and higher glutamate release. Whereas metabolomic studies showed that TPFPD-exposed microglia were closely related to classically activated M1 proinflammatory cells, notably with similar tricarboxylic acid cycle disruption, transcriptomic analysis revealed that TPFPD-activated microglia assume a unique molecular signature highlighting upregulation of genes involved in glutathione and iron metabolisms. In particular, TPFPD-specific upregulation of Slc7a11 (which encodes the cystine-glutamate antiporter xCT) was consistent with the increased glutamate response and cytotoxic activity of these cells toward midbrain dopaminergic neurons in vitro. Together, these data further extend the structure-pathological relationship of αSYN fibrillar polymorphs to their innate immune properties and demonstrate that PD-derived αSYN fibrils, TNFα and PGE2 act in concert to drive microglial cell activation toward a specific and highly neurotoxic chronic-type inflammatory phenotype characterized by robust glutamate release and iron retention.

Closing the knowledge gap: Helminth parasites of freshwater turtles from the Chaco-Pampa Plain, Southern South America.

Six species of freshwater turtles dominate the Chaco-Pampa Plain in southern South America and their parasites have been relatively understudied, with most records concentrated in Brazil. Particularly in Argentina, there are only scattered records of parasites for most of the turtles that inhabit the region, leaving a large knowledge gap. The purpose of the present contribution is to increase the knowledge of the internal parasites of six species of freshwater turtles from Argentina, after 15 years of fieldwork, by providing new hosts and additional geographic records for many host-parasite relationships. Some molecular sequences of the studied parasites were provided as a tool for better species identification. We processed 433 stomach and fecal samples from live individuals and visceral and soft tissue samples from 54 dissected turtles collected from a wide range and different ecoregions. We found 6230 helminths belonging to 18 taxa (one cestode, 11 digeneans and six nematodes). Fourteen new parasite-host associations are reported here, and for the first time parasites are recorded for Phrynops williamsi. This work contributes significantly to the knowledge of the parasitofauna in freshwater turtles in Argentina, providing a detailed list of parasites present in each turtle species and reporting molecular characters for future studies.

Phylogenetic relationship between Contracaecum spp. (Nematoda, Anisakidae) parasitizing cormorants (Aves, Phalacrocoracidae) in Argentina.

Species of the genus Contracaecum (Family Anisakidae) exhibit a broad host and geographical distribution, parasitizing aquatic organisms such as piscivorous birds and mammals as their definitive hosts. Several Contracaecum species have been reported parasitizing cormorants (Family: Phalacrocoracidae) in South America. The objective of this study was to highlight phylogenetic relationships between Contracaecum species parasitizing cormorants based on both molecular analyses and the papillae arrangement on the male tail. Some Contracaecum species parasitizing Red-legged cormorants from the Ría Deseado (RD), and other nematodes parasitizing eight Neotropic cormorants from San Miguel del Monte lagoon (SMML), Argentina, were collected and analyzed. Both morphological and phylogenetic analyses allowed us to recognize two species: Contracaecum chubutensis parasitizing Phalacrocorax gaimardi, and Contracaecum australe parasitic in Phalacrocorax brasilianus. According to the obtained sequences (mtDNA cox2, ITS1, ITS2, and SSrRNA), Contracaecum sp. parasitizing P. gaimardi exhibited concordance with the previously reported C. chubutensis parasitizing P. atriceps from Bahía Bustamante, Chubut province. Likewise, Contracaecum sp. isolates parasitizing P. brasilianus showed concordance with C. australe from Chile. Besides, the papillae arrangement on the male tail allowed us to understand the interspecific and genetic relationships between the Contracaecum species. The analyses confirm that C. chubutensis specimens parasitizing P. gaimardi from RD present a new host record for the species, whereas, those C. australe specimens parasitizing P. brasilianus from SMML provide a new geographical record for the species and the extension of its distribution range. Present results also confirm the inland and marine distribution of C. australe and C. chubutensis, respectively.

Description of patterns of ear and tail lesions during the grower-finisher period in a commercial pig farm.

BACKGROUND: Ear and tail lesions are prevalent indicators of impaired welfare observed in pig production with different multifactorial causes. Understanding the progression of ear and tail lesions over time is important to implement preventative strategies on commercial pig farms. Therefore, this case study aimed to provide a detailed account of patterns of ear and tail lesions in pigs on a single commercial farm during the grower-finisher period. CASE PRESENTATION: A total of 1,676 12-week old pigs (n = 773 females and n = 903 males, all tail docked) were followed from arrival to the grower facilities until transferred to the finisher stage on a commercial pig farm in Ireland. Pigs were individually weighed and inspected for the severity of fresh ear and tail lesions (score 0-4) on transfer to the first grower (24.9 ± 5.33 kg, 12 weeks of age, n = 1,676 pigs), second grower (33.3 ± 7.04 kg, 14 weeks of age, n = 1,641 pigs), and finisher stage (60.2 ± 7.74 kg, 18 weeks of age, n = 1,626 pigs). Due to the low number of pigs with high scores, ear lesions were classified as no (score 0), mild (score 1), moderate (score 2) and severe (score ≥ 3) and tail lesions were classified as no (score 0), mild (score 1), and moderate-to-severe (score ≥ 2). Ear lesions were more prevalent than tail lesions at each inspection. There were approx. 19% of pigs with ear lesions at all three inspections but no pigs presented with tail lesions at all three inspections. When considering the specific severity categories, we observed 32 different ear lesion score combinations and 15 different tail lesion score combinations across the three inspections. CONCLUSION: The high number of observed patterns of ear and tail lesions suggest large individual variability in lesion progression. Ear lesions were more of an issue than tail lesions and little is known about this health and welfare problem indicating that further research into causes and management strategies is needed.

Dissolved organic phosphorus bond-class utilization by Synechococcus.

Dissolved organic phosphorus (DOP) contains compounds with phosphoester, phosphoanhydride, and phosphorus-carbon bonds. While DOP holds significant nutritional value for marine microorganisms, the bioavailability of each bond-class to the widespread cyanobacterium Synechococcus remains largely unknown. This study evaluates bond-class specific DOP utilization by Synechococcus strains from open and coastal oceans. Both strains exhibited comparable growth rates when provided phosphate, a phosphoanhydride [3-polyphosphate and 45-polyphosphate], or a DOP compound with both phosphoanhydride and phosphoester bonds (adenosine 5'-triphosphate). Growth rates on phosphoesters [glucose-6-phosphate, adenosine 5'-monophosphate, bis(4-methylumbelliferyl) phosphate] were variable, and neither strain grew on selected phosphorus-carbon compounds. Both strains hydrolyzed 3-polyphosphate, then adenosine 5'-triphosphate, and lastly adenosine 5'-monophosphate, exhibiting preferential enzymatic hydrolysis of phosphoanhydride bonds. The strains' exoproteomes contained phosphorus hydrolases, which combined with enhanced cell-free hydrolysis of 3-polyphosphate and adenosine 5'-triphosphate under phosphate deficiency, suggests active mineralization of phosphoanhydride bonds by these exoproteins. Synechococcus alkaline phosphatases presented broad substrate specificities, including activity toward the phosphoanhydride 3-polyphosphate, with varying affinities between strains. Collectively, these findings underscore the potentially significant role of compounds with phosphoanhydride bonds in Synechococcus phosphorus nutrition and highlight varied growth and enzymatic responses to molecular diversity within DOP bond-classes, thereby expanding our understanding of microbially mediated DOP cycling in marine ecosystems.

Energy flux couples sulfur isotope fractionation to proteomic and metabolite profiles in Desulfovibrio vulgaris.

Microbial sulfate reduction is central to the global carbon cycle and the redox evolution of Earth's surface. Tracking the activity of sulfate reducing microorganisms over space and time relies on a nuanced understanding of stable sulfur isotope fractionation in the context of the biochemical machinery of the metabolism. Here, we link the magnitude of stable sulfur isotopic fractionation to proteomic and metabolite profiles under different cellular energetic regimes. When energy availability is limited, cell-specific sulfate respiration rates and net sulfur isotope fractionation inversely covary. Beyond net S isotope fractionation values, we also quantified shifts in protein expression, abundances and isotopic composition of intracellular S metabolites, and lipid structures and lipid/water H isotope fractionation values. These coupled approaches reveal which protein abundances shift directly as a function of energy flux, those that vary minimally, and those that may vary independent of energy flux and likely do not contribute to shifts in S-isotope fractionation. By coupling the bulk S-isotope observations with quantitative proteomics, we provide novel constraints for metabolic isotope models. Together, these results lay the foundation for more predictive metabolic fractionation models, alongside interpretations of environmental sulfur and sulfate reducer lipid-H isotope data.

Calidad de vida y funcionalidad en sobrevivientes de cuidados intensivos: Una revisión exploratoria / Quality of life and functionality of intensive care survivors: An exploratory review / Qualidade de vida e funcionalidade em sobreviventes de terapia intensiva: uma revisão exploratória

Introducción: La calidad de vida en pacientes críticos que sobreviven al tratamiento en unidades de cuidados intensivos es inferior al de la población general. La condición de salud basal y la severidad de la condición clínica al ingreso a terapia intensiva son factores de riesgo para la calidad de vida y la funcionalidad. Objetivo: Analizar el nivel de conocimiento en la calidad de vida y la funcionalidad de los sobrevivientes de cuidados intensivos. Materiales y métodos: Se realizó una revisión exploratoria en las bases de datos: Scielo, PubMed, Science Direct, ProQuest, Redalyc, Dialnet, OVID, Scopus, publicados entre enero del año 2010 y mayo del año 2020. El estudio se desarrolló según la estructura de la Metodología PRISMA. Se revisaron y analizaron los textos completos que cumplían los criterios de inclusión para la selección final de los artículos. Resultados: De 1814 artículo seleccionados, se eligieron 65 artículos que describen la calidad de vida y la funcionalidad en pacientes después de cuidados intensivos, y finalmente, 16 artículos son incluidos, donde se analizaron las características de los artículos, las características de la población estudiada, y las variables de análisis sobre la evaluación de la calidad de vida y la funcionalidad en los sobrevivientes después cuidados intensivos. Conclusión: Los estudios sobre calidad de vida y funcionalidad en sobrevivientes de cuidados intensivos se realizaron en mayor proporción en Europa en los años 2010 a 2016. Con estudios observacionales prospectivos que correlacionan los factores que determinan la salud mental y física después del egreso de cuidados intensivos. Se aplicaron múltiples escalas siendo las más utilizadas SF-36 y el EQ-5D para evaluar la calidad de vida y del índice de Barthel para determinar el estado de funcionalidad en los egresados de cuidados intensivos. El SF-36 y el índice de Barthel reportaron una afectación en la calidad de vida y en la funcionalidad en la población sobreviviente de cuidados intensivos.

Introduction:The quality of life of critically ill patients who survive treatment in intensive care units is lower than that of the general population. Baseline health status and severity of clinical condition on admission to intensive care are risk factors for quality of life and functionality. Objetive: To analyze the level of knowledge on quality of life and functionality of intensive care survivors. Materials and Methods: An exploratory review was conducted by searching studies published between January 2010 and May 2020 in Scielo, PubMed, Science Direct, ProQuest, Redalyc, Dialnet, OVID, and Scopus databases. The study was conducted according to the PRISMA statement. Full texts that met the inclusion criteria were reviewed and analyzed in the final selection of articles. Results: Of 1814 articles identified, 65 articles describing the quality of life and functionality in post-intensive care patients were screened. Finally, 16 were included to analyze the article's characteristics, population characteristics, and variables of analysis for assessing the quality of life and functionality of post-intensive care survivors. Conclusions: Studies on quality of life and functionality in intensive care survivors were conducted mainly in Europe between 2010 and 2016. They are primarily prospective observational studies correlating factors determining mental and physical health after intensive care discharge. Multiple scales were applied; the most used were the SF-36 and the EQ-5D to assess the quality of life and the Barthel Index to determine functional status in patients discharged from intensive care. The SF- 36 and Barthel index reported impaired quality of life and functionality of the intensive care survivor population.

Introdução: A qualidade de vida em pacientes críticos que sobrevivem ao tratamento em unidades de terapia intensiva é inferior à da população geral. A condição de saúde de base e a gravidade do quadro clínico na admissão à terapia intensiva são fatores de risco para qualidade de vida e funcionalidade. Objetivo: Analisar o nível de conhecimento sobre qualidade de vida e funcionalidade de sobreviventes de terapia intensiva. Materiais e Métodos: Foi realizada uma revisão exploratória nas seguintes bases de dados: Scielo, PubMed, Science Direct, ProQuest, Redalyc, Dialnet, OVID, Scopus, publicadas entre janeiro de 2010 e maio de 2020. O estudo foi desenvolvido de acordo com a estrutura da Metodologia PRISM. Os textos completos que atenderam aos critérios de inclusão foram revisados e analisados para a seleção final dos artigos. Resultados: Dos 1.814 artigos selecionados, foram escolhidos 65 artigos que descrevem a qualidade de vida e funcionalidade em pacientes após terapia intensiva e, por fim, são incluídos 16 artigos, onde são apresentadas as características dos artigos, as características da população estudada e as variáveis de análise sobre a avaliação da qualidade de vida e funcionalidade em sobreviventes após terapia intensiva. Conclusões: Estudos sobre qualidade de vida e funcionalidade em sobreviventes de terapia intensiva foram realizados em maior proporção na Europa nos anos de 2010 a 2016. Com estudos observacionais prospectivos que correlacionam os fatores que determinam a saúde mental e física após a alta da terapia intensiva. Foram aplicadas múltiplas escalas, sendo as mais utilizadas o SF-36 e o EQ-5D para avaliar a qualidade de vida e o índice de Barthel para determinar o estado de funcionalidade em egressos de terapia intensiva. O SF-36 e o índice de Barthel relataram impacto na qualidade de vida e funcionalidade na população sobrevivente de terapia intensiva.

Gastropods as intermediate hosts of Angiostrongylus spp. in the Americas: bioecological characteristics and geographical distribution

BACKGROUND Intermediate hosts are key organisms in maintaining parasite life cycles, because they can act as amplifiers in the transmission from natural reservoirs to humans. One of the most important groups of intermediate hosts for zoonotic nematode infections are gastropods,slugs and snails. These are essential organisms in the larval development of Angiostrongylus species. OBJECTIVES The objective of this paper is to review reports of Angiostrongylus spp. in naturally infected gastropods from the Americas, taking into account the diagnostic methods used in their identification, to be able to provide more accurate list of their intermediate hosts. We also discuss the factors that aid the dispersion of Angiostrongylus spp. in the Americas. METHODS This study reviews scientific publications and book sections on Angiostrongylus spp. in the Americas, including original works assessing larvae of Angiostrongylus in intermediate hosts. The eligible reports were classified accordingly to their geographical location, year of first record, and the larvae identification methodologies used. Digital repositories were used for the search. The bioecological characteristics of the main intermediate hosts are summarised. FINDINGS A total of 29 gastropod species that are naturally infected with Angiostrongylus spp. have been reported as intermediate hosts, 16 of which are land snails, two are freshwater snails, and 11 land slugs. MAIN CONCLUSIONS This study highlights the importance of integrative studies, analysing both the etiological agent and its transmission dynamic in the environment, the biological and ecological characteristics of the hosts, and the impact on host populations. It is necessary to increase interdisciplinary studies to determine the potential epidemiological health risk of angiostrongyliasis in the Americas, and thus be able to establish prevention, monitoring and contingency strategies in the region.

Angiostrongylus spp. in the Americas: geographical and chronological distribution of definitive hosts versus disease reports

BACKGROUND Angiostrongyliasis is an infection caused by nematode worms of the genus Angiostrongylus. The adult worms inhabit the pulmonary arteries, heart, bronchioles of the lung, or mesenteric arteries of the caecum of definitive host. Of a total of 23 species of Angiostrongylus cited worldwide, only nine were registered in the American Continent. Two species, A. cantonensis and A. costaricensis, are considered zoonoses when the larvae accidentally parasitise man. OBJECTIVES In the present study, geographical and chronological distribution of definitive hosts of Angiostrongylus in the Americas is analysed in order to observe their relationship with disease reports. Moreover, the role of different definitive hosts as sentinels and dispersers of infective stages is discussed. METHODS The study area includes the Americas. First records of Angiostrongylus spp. in definitive or accidental hosts were compiled from the literature. Data were included in tables and figures and were matched to geographic information systems (GIS). FINDINGS Most geographical records of Angiostrongylus spp. both for definitive and accidental hosts belong to tropical areas, mainly equatorial zone. In relation to those species of human health importance, as A. cantonensis and A. costaricensis, most disease cases indicate a coincidence between the finding of definitive host and disease record. However, in some geographic site there are gaps between report of definitive host and disease record. In many areas, human populations have invaded natural environments and their socioeconomic conditions do not allow adequate medical care. MAIN CONCLUSIONS Consequently, many cases for angiostrongyliasis could have gone unreported or unrecognised throughout history and in the nowadays. Moreover, the population expansion and the climatic changes invite to make broader and more complete range of observation on the species that involve possible epidemiological risks. This paper integrates and shows the current distribution of Angiostrongylus species in America, being this information very relevant for establishing prevention, monitoring and contingency strategies in the region.

Radioterapia en el Cáncer Cérvico Uterino: estudio retrospectivo enero 2006 diciembre2009 / Radiotherapy of cervical cancer: retrospective study during january 2006 and december 2009

Con el objetivo de evaluar la eficacia del tratamiento con Radioterapia del Cáncer Cérvico Uterinoen la región central de Cuba, se realizó un estudio descriptivo, retrospectivo y transversal apacientes atendidas en el Servicio de Radioterapia del Hospital Universitario Dr CelestinoHernández Robau de Villa Clara, entre enero de 2006 a diciembre de 2009. La población laintegraron 320 pacientes y la muestra estuvo conformada por 169 seleccionadas por muestreoaleatorio; procedentes mayoritariamente de la provincia de Villa Clara y Sancti-Spíritusagrupándose por edad entre los 36 y 40 años principalmente. El tipo histológico que predominó fue el carcinoma epidermoide y el estadio clínico IIB. El mayor número de las pacientes mostrórespuesta clínica completa, de la muestra ensayada recidivaron 81 enfermas(AU)

With the objective to evaluate radotherapy treatment efficacy of cervical cancer in the CentralRegion of Cuba, a descriptive retrospective and transversal study was made to patients attended In Radiotherapy Service of the University Hospital Dr Celestino Hernández Robau located in SantaClara, betweem january 2006 and december 2009. The population was conformed by 320 patientsand for the sample were selected 169 persons taking into consideration the aleatory sample,belonging them mainly from Villa Clara province and Sancti Spiritus. They were joined according tothe age (36 and 40 years ). The histological type obtained was epidermoide carcinome and theclinical state IIB. A great quantity of patients showed a complete clinical answer, from the samplewere 81 recidivation(AU)

Distribución de los esfuerzos en tres tipos de elementos intrarradiculares con diferentes longitudes / Stress distribution in three types of posts with different lengths

Introducción: el objetivo fue observar la distribución de los esfuerzos en los dientes restaurados con elementos de retención intrarradicular (postes) de diferentes longitudes, usando el análisis de elementos finitos (AEF). Métodos: un modelo tridimensional de elementos finitos (modelo de 4 mm con 34.010 nodos y 9.317 elementos, modelo de 6mm con 36.798 nodos y 10.371 elementos, modelo de 8 mm con 38.587 nodos y 11.025 elementos) de un incisivo central superior es presentado. El modelo del diente restaurado con un poste está formado por hueso esponjoso, hueso cortical, ligamento periodontal, encía, raíz, gutapercha, cemento resinoso, postes, muñón de resina (para postes prefabricados), cofia metálica y corona cerámica. Los diferentes postes fueron modelados en una aleación de metal noble, titanio y fibra de vidrio. Los postes fueron cementados con cemento resinoso. Las variables incluidas en el modelado fueron el módulo de elasticidad, la razón de Poisson y la longitud del poste (4, 6 y 8 mm). Se aplicó una carga de 1 N en la corona con una inclinación de 45o y fueron calculados los esfuerzos de von Mises, los esfuerzos máximos y mínimos principales y los esfuerzos máximos cortantes. Resultados: el análisis de elementos finitos indicó que la distribución de los esfuerzos generados en el diente modelado con los diferentes postes disminuyó significativamente, de acuerdo con una relación inversamente proporcional con el módulo de elasticidad del material. Los esfuerzos en la raíz también se vieron reducidos al incrementar la longitud del poste (4, 6 y 8 mm). Conclusiones: con las limitantes de este estudio, se encontró que existen variaciones marcadas con respecto a la longitud de los postes relacionadas con la distribución de los esfuerzos en la dentina y en el mismo poste, siendo menor la distribución de los esfuerzos en la dentina con postes de mayor longitud y de mayor módulo de elasticidad.

Amelogenesis imperfecta: alternativas de tratamiento / Amelogenesis imperfecta: treatment alternatives

La comprensión y entendimiento de trastornos del desarrollo que afectan a las estructuras bucales, se logra mediante el conocimiento de su embriología, histología y la revisión de conceptos genéticos actuales. Estos defectos se pueden presentar desde el nacimiento y algunos de ellos siguen patrones de herencia por lo que se debe de ser cuidadoso al diferenciar trastornos hereditarios de los congénitos. La amelogénesis imperfecta es un desarrollo defectuoso del esmalte, representa el clásico trastorno hereditario que afecta a esta estructura, teniendo presente su no incidencia con cualquier otro trastorno de tipo sindromico, metabólico o sistémico. Actualmente se conocen tres tipos de amelogénesis imperfecta; de tipo hipoplásico, hipomaduración e hipocalcificado, las cuales pueden presentar una variedad de hasta once fenotipos, según el tipo de herencia mendeliana. El aspecto del esmalte afectado puede presentar defectos que van desde los imperceptibles hasta los que afectan muy notablemente la apariencia y función dental. Según David Bixler, este tipo de trastornos ocasionan en el paciente severos daños en su desarrollo psicológico y social, llegando a afectar en la mayoría de los casos la autoestima del niño o adolescente. (David Bixler, 1998). El odontólogo debe conocer alternativas de tratamiento que brinden al paciente una solución estética y funcional a este padecimiento. Antiguamente, la única alternativa de solución que se le ofrecía al paciente era la extracción total o parcial de la dentadura afectada y posteriormente la confección de una prótesis total o parcial, situación que además de drástica resultaba traumática para el paciente. (Dominique Bouvier, 1999). La presente investigación bibliografica describe alternativas de tratamiento que proporcionan soluciones estéticas y funcionales a pacientes que presentan amelogénesis imperfecta; revisando materiales y técnicas antiguas de restauración como lo son las amalgamas de plata y coronas de acero cromado, y materiales mas recientemente desarrollados como cementos de ionómero de vidrio, compomeros, resinas composites y la porcelana dental en sus diferentes aplicaciones clínicas (carillas y coronas); que son esencialmente las mejores alternativas para tratar la amelogénesis imperfecta. Es necesario mencionar la ausencia de referencias documentales en cuanto a los tratamientos y/o técnicas específicas para cada tipo de amelogénesis imperfecta, ya que en cada caso es el odontólogo quien debe decidir el material y la técnica adecuada, según las características clínicas y condiciones bajo las que se presenta el paciente.

The understanding and understanding of developmental disorders that affect oral structures is achieved through knowledge of their embryology, histology and the review of current genetic concepts. These defects can occur from birth and some of them follow inheritance patterns, so care must be taken when differentiating inherited from congenital disorders. Amelogenesis imperfecta is a defective development of the enamel, it represents the classic hereditary disorder that affects this structure, taking into account its non-incidence with any other syndromic, metabolic or systemic disorder. Three types of amelogenesis imperfecta are currently known; hypoplastic, hypomaturated and hypocalcified, which can present a variety of up to eleven phenotypes, depending on the type of Mendelian inheritance. The appearance of the affected enamel can present defects that range from the imperceptible to those that affect the appearance and tooth function in a very noticeable way. According to David Bixler, this type of disorder causes serious damage to the psychological and social development of the patient, affecting in most cases the self-esteem of the child or adolescent. (David Bixler, 1998). The dentist must know treatment alternatives that provide the patient with an aesthetic and functional solution to this condition. In the past, the only alternative solution that was offered to the patient was the total or partial extraction of the affected teeth and later the realization of a total or partial prosthesis, a situation that was also drastic for the patient. (Dominique Bouvier, 1999). The present bibliographic research describes treatment alternatives that provide aesthetic and functional solutions to patients with amelogenesis imperfecta; review old restorative materials and techniques such as silver amalgams and chrome steel crowns, and more recently developed materials such as glass ionomer cements, compomers, composite resins and dental porcelain in their different clinical applications (veneers and crowns); which are essentially the best alternatives for the treatment of amelogenesis imperfecta. It is necessary to mention the absence of documentary references on the treatments and / or specific techniques for each type of amelogenesis imperfecta, since in each case it is the dentist who must decide the appropriate material and technique, according to the clinical characteristics and conditions under those presented by the patient.