Trichoderma spp., una alternativa para la agricultura sostenible: una revisión

En la actualidad uno de los retos a los que se enfrentan los agricultores es producir alimentos bajo las inclemencias climáticas. Para el 2050, se estima un aumento en la demanda en producción de alimentos básicos a causa del incremento demográfico, aumentando con ello el detrimento de los recursos naturales. Dentro de las alternativas biológicas está el uso de insumos a base de microorganismos benéficos, como el género Trichoderma. Los cuales se han utilizado en los campos agrícolas para el control biológico contra un gran número de fitopatógenos. Sin embargo, aún son poco conocidas otras propiedades benéficas de este género para las plantas que coloniza y el ecosistema. Se realizó una búsqueda de artículos científicos en Academic Search Ultimate, BioOne, Acsess, Esmerald, Fuente Académica, ScienceDirect y Springer, entre 2015 y 2023, con dos excepciones de años anteriores. Se utilizó la palabra clave "Trichoderma" y aquellas relacionadas con interacciones microbianas y su aplicación agrícola. Esta revisión resume los hallazgos bibliográficos actuales de este género que muestran su alta capacidad hacia el desarrollo sostenible de los agroecosistemas. Varias investigaciones reportan su capacidad de inducir la defensa vegetal, la promoción del crecimiento y desarrollo radicular, así como la estimulación y síntesis de sustancias que contribuyen a fortalecer la fertilidad del suelo. Con ello mejora los rendimientos de los cultivos a los que se encuentra asociado. En definitiva, la aplicación de Trichoderma puede coadyuvar a disminuir los efectos negativos ocasionados por el uso de agroquímicos y fertilizantes sintéticos, contribuyendo a una producción más sostenible.

Currently, one of the most critical challenges facing farmers is the production of food under adverse weather conditions. By 2050, an increase in the production of staple foods is estimated due to demographics, thereby increasing the depletion of natural resources. Among the biological alternatives is the use of inputs based on beneficial microorganisms such as the Trichoderma genus, which have been used in agricultural fields for biological control against a large number of phytopathogens. However, other beneficial properties of this genus for the plants it colonizes, and the ecosystem are still little known. Therefore, a search for scientific articles was carried out in Academic Search Ultimate, BioOne, Acsess, Esmerald, Fuente Academic, ScienceDirect and Springer, between 2015 and 2023, with two exceptions from previous years. The keyword "Trichoderma" was used and those related to microbial interactions and their agricultural application. Therefore, this review summarizes the current bibliographic findings of this genus, that shows its high capacity towards the sustainable development of agroecosystems. Several investigations report its ability to induce plant defense, promote growth and root development, and stimulate and synthesize substances that help strengthen soil fertility. This improves the yields of the crops to which they are associated. With this, the application of Trichoderma can reduce the negative effects caused by the use of agrochemicals and synthetic fertilizers, contributing to a more sustainable production.

Seed morphology and germination of Willd. ex Schult. emulating environmental conditions within ant nest.

Damiana (Turnera diffusa Willd. ex Schult.) is a species of plant used in traditional Mexican medicine for its aphrodisiac properties. Although it has a high commercial demand, both nationally and internationally, its sexual propagation is not usual due to the low percentage of seed germination. It has been proposed that ants play an important role in germination, due to the presence of elaiosomes. Therefore, the objectives of this study were to characterize the seed morphology of T. diffusa for agronomic purposes, analyze their viability, and evaluate their germination by simulating environmental conditions of an ant nest. For the morphological characterization, 30 seeds were selected and evaluated for the variables of color, size, and weight. Viability was evaluated with a tetrazolium test using two lots of seeds collected in 2016 and 2017, with different concentrations and three exposure times at 40°C. The germination of T. diffusa was evaluated under three pre-germination treatments and nine germination treatments. The results of the study showed that the seeds of T. diffusa have an average size of 0.725 mm long and 0.182 mm wide; the color of the seeds varies from brown to black when ripe and yellowish white when immature. There are no significant differences in the viability percentage (60%) for seeds collected in 2016 and 2017 (p = 0.20). On the other hand, there are significant differences between all the pre-germination and germination tests analyzed. Seeds of T. diffusa have the highest percentage of germination (36%) with the presence of elaiosome and 500 ppm of GA3. The germination interval of the seeds occurs over a period of six to 39 days. The application of GA3 in the germination of the seeds indicates that they present a physiological latency which was inhibited at concentrations of 500 and 300 ppm.

Genome sequencing identifies coding and non-coding variants for non-syndromic hearing loss.

Hearing loss (HL) is a common heterogeneous trait that involves variants in more than 200 genes. In this study, we utilized exome (ES) and genome sequencing (GS) to effectively identify the genetic cause of presumably non-syndromic HL in 322 families from South and West Asia and Latin America. Biallelic GJB2 variants were identified in 58 probands at the time of enrollment these probands were excluded. In addition, upon review of phenotypic findings, 38/322 probands were excluded based on syndromic findings at the time of ascertainment and no further evaluation was performed on those samples. We performed ES as a primary diagnostic tool on one or two affected individuals from 212/226 families. Via ES we detected a total of 78 variants in 30 genes and showed their co-segregation with HL in 71 affected families. Most of the variants were frameshift or missense and affected individuals were either homozygous or compound heterozygous in their respective families. We employed GS as a primary test on a subset of 14 families and a secondary tool on 22 families which were unsolved by ES. Although the cumulative detection rate of causal variants by ES and GS is 40% (89/226), GS alone has led to a molecular diagnosis in 7 of 14 families as the primary tool and 5 of 22 families as the secondary test. GS successfully identified variants present in deep intronic or complex regions not detectable by ES.

Sordera neurosensorial congénita con malformación de oído interno ligada al X en una familia mexicana / Congenital sensorineural deafness X-linked, with inner ear malformation in a Mexican family

Introducción. Las sorderas o hipoacusias prelinguales son de etiología genética entre el 60 y el 68% de los casos; de estos, del 20 al 40% son malformaciones del oído interno. De los casos de hipoacusia no sindrómica ligada al X se han descrito siete tipos. De las malformaciones de oído interno, la partición coclear incompleta tipo III es la menos frecuente.Objetivo. Presentar el reporte clínico-genético de una familia mexicana, con indi-viduos varones afectados por sordera neurosensorial congénita con malformación de oído interno. Material y Métodos. Se realizó estudio de una familia en la que nueve miembros presentaban sordera. Se estudiaron cuatro de ellos y una madre sin manifestaciones, a través del estudio clínico general por médico genetista, el estudio audiológico (otos-copía y audiometría) por médico audiólogo y el estudio de tomografía computada (TC) por médico radiólogo.Resultados. Los pacientes estudiados presentaron sordera neurosensorial congéni-ta, de severa a profunda bilateral. A través de la TC, se evidenció malformación de oído interno. Tres pacientes presentaron partición coclear incompleta tipo III y un paciente partición incompleta tipo I. Debido al estudio clínico y al árbol genealógico, se definió diagnóstico de hipoacusia neurosensorial no sindrómica ligada al X. La TC de la madre sin manifestaciones no presentó evidencia de malformaciones en oído interno (MOI).Conclusión. El estudio de imagen es fundamental para definir presencia o no de MOI en todos los pacientes con hipoacusia y así poder guiar la terapéutica y el aseso-ramiento genético, así como realizar los estudios moleculares más adecuados

Introduction. The pre-lingual deafness or hearing loss are of genetic cause in be-tween 60% and 68% of cases, among these, between 20% and 40% are malforma-tion of the inner ear. From the non-syndromic hearing loss cases that are linked to the X chromosome, seven types have been described. Among these inner ear malforma-tions, incomplete cochlear partition type III is the less frequent.Objective. Present the clinical genetical report of a Mexican family, with male in-dividuals affected by congenital neurosensory deafness with inner ear malformation.Materials and methodology. A study on a family in which nine members were affected by deafness was done. Four of them, plus a mother without manifestation, were studied through a general clinical study by a geneticist, an audiological study (otoscopy and audiometry) by an audiologist, and a computed tomography (CT) scan by a radiologist.Results. The studied patients presented congenital neurosensory deafness, from se-vere to deep bilateral. Via the CT, the inner ear malformation was made clear. Three of the patients presented incomplete cochlear partition type III and one patient in-complete cochlear partition type I. Due to the clinical study and the family tree, it was diagnosed non-syndromic neurosensory deafness linked to X. The CT of the mother without manifestation did not show evidence of inner ear malformations.Conclusion. The study by image is fundamental to define whether there is or not a presence of inner ear malformations in any patient with heading loss to be able to guide the therapeutics and the genetic counseling, as well as to make more accurate molecular studies

The GLIM criteria for adult malnutrition and its relation with adverse outcomes, a prospective observational study.

BACKGROUND & AIMS: Malnutrition is considered a risk factor for many complications and mortality among hospitalized patients. Until 2016 there was a wide variety of clinical definitions for malnutrition, until the GLIM criteria proposed a consensual definition. The main goal of this study is to assess the performance of the GLIM criteria at acute care admission to detect those patients with adverse clinical outcomes such as mortality and the need to be transferred to critical care areas (CCA). METHODS: This was a prospective observational study including every adult patient admitted to the regular ward of the Hospital San Ángel Inn Universidad. Every nutrition and demographic variable evaluated by the nutrition team at hospital admission was captured. The malnutrition definition according to the GLIM and separate criteria were tested for their performance to detect patients at high risk for adverse outcomes (mortality and the need to be transferred to CCA), using odd ratios (OR), their confidence interval of 95% (CI95%) and binary logistic regression accordingly. RESULTS: A total of 1015 patients were included in the final analysis, with a prevalence of 18.9% of malnutrition (according to the GLIM definition) at hospital admission. Malnutrition was associated with mortality (OR of 59.69,CI95% 7.76-459.28) and unplanned transfer to CCA (OR of 9.453, CI95%4.35-20.56). However, despite being sensitive, the GLIM definition of malnutrition, displayed low positive predictive value, and was therefore associated with many false positives. There was a trend for higher risks for adverse outcomes with higher severity of malnutrition. Muscle wasting, chronic and acute inflammation were independent predictors for mortality and for unplanned transfer to CCA. CONCLUSIONS: Malnutrition according to the GLIM criteria is strongly associated with mortality and transfer to CCA. Muscle wasting and inflammation (acute and chronic) were independently associated with these outcomes.

Clinopodium mexicanum: potential and difficulties for the sustainable use of a Mexican medicinal plant / Clinopodium mexicanum: potencial y dificultades para el uso de una planta medicinal mexicana

Clinopodium mexicanum (Benth.) Govaerts (Lamiaceae) is a native plant of Mexico. This plant is used in traditional Mexican medicine for the treatment of cultural specific syndromes such as "susto", "nervios" or "espanto", conditions related to anxiety and depression. In addition, it has a high biocultural value for its medicinal and culinary use and for its exchange value in various indigenous areas of México. This review aims to compile updated information about the ethnobotanical, phytochemistry and commercialization aspects of Clinopodium mexicanum, and it focuses on the potential use of this species as a raw material in the phytopharmaceutical industry for the treatment of anxiety and pain. Moreover, it would be a viable productive alternative for many rural communities, which could not only produce the raw material but who could also add value to the sale of the plant.

Clinopodium mexicanum (Benth.) Govaerts, es una planta nativa de México. Es usada en la medicina tradicional mexicana para tratar síndromes de filiación cultural como "susto", "nervios" o "espanto", los cuales están asociados a la ansiedad y depresión. Además, la planta presenta un alto valor biocultural por sus usos: medicinal, culinario y por el valor de cambio que tiene en áreas indígenas de México. La revisión presentada tiene como objetivo compilar información actualizada sobre aspectos etnobotánicos, fitoquímicos y comercialización de Clinopodium mexicanum. Igualmente señalar el potencial uso de esta especie como materia prima para la elaboración de productos para la ansiedad y el dolor por parte de la industria fitofarmacéutica. Además de ser una alternativa productiva para muchas comunidades rurales, las cuales pueden venderla como materia prima o como producto derivado.

Novel pathogenic variants underlie SLC26A4-related hearing loss in a multiethnic cohort.

OBJECTIVES: The genetics of sensorineural hearing loss is characterized by a high degree of heterogeneity. Despite this heterogeneity, DNA variants found within SLC26A4 have been reported to be the second most common contributor after those of GJB2 in many populations. METHODS: Whole exome sequencing and/or Sanger sequencing of SLC26A4 in 117 individuals with sensorineural hearing loss with or without inner ear anomalies but not with goiter from Turkey, Iran, and Mexico were performed. RESULTS: We identified 27 unique SLC26A4 variants in 31 probands. The variants c.1673A > G (p.N558S), c.1708-1G > A, c.1952C > T (p.P651L), and c.2090-1G > A have not been previously reported. The p.N558S variant was detected in two unrelated Mexican families. CONCLUSION: A range of SLC26A4 variants without a common recurrent mutation underlies SLC26A4-related hearing loss in Turkey, Iran, and Mexico.

Antibody-coupled hydroxyapatite nanoparticles as efficient tools for labeling intracellular proteins.

Smart biomaterials for active targeting are a novel way for biosensing, gene and drug delivery, and bioimaging. The functional additives are chosen according to the material carrier characteristics, i.e. the functional mercapto acids of different lengths. In order to identify the target tissue, cell, organ or molecule, the biomaterial must be equipped with a recognizing molecule on its surface. In most cases, semiconductor o metal materials are employed in bioimaging and biosensing applications; in gene and drug delivery area, it is useful to employ porous nanoparticles as carriers. Hydroxyapatite nanoparticles have been proved efficiently in drug delivery. In this work we established a new protocol to obtain smart hydroxyapatite nanoparticles with 3-mercaptopropionic acid and anti-Actin molecules in order to localize actin molecules in cells.

Giant Basal Cell Carcinoma: A 12-Year Follow-up Case Report.

Giant basal cell carcinomas (GBCCs) are a strange and aggressive variety of basal cell carcinomas (BCCs); they are characterized by deep tissue invasion, rapid growth, high risk of metastasis, and a poor prognosis. GBCCs represent 0.4%-1% of all BCCs. The pathogenesis of GBCC is sometimes linked to a spontaneous mutation in the PTCH gene, mapped to the q22.33 locus of chromosome 9. The key factor in the development of GBCC, in at least 30% of the cases, is the delay in seeking medical attention (7.5 ± 3.1 years). This is associated to a poor socioeconomic level, deficient hygiene, mental illness, advanced age, and the fact that BCCs are painless lesions. The authors present a Mexican female with a 2-year ulcer diagnosed as a GBCC in the year 2000, its initial therapeutic approach, and her follow-up during the next 12 years.

Comprehensive analysis via exome sequencing uncovers genetic etiology in autosomal recessive nonsyndromic deafness in a large multiethnic cohort.

PURPOSE: Autosomal recessive nonsyndromic deafness (ARNSD) is characterized by a high degree of genetic heterogeneity, with reported mutations in 58 different genes. This study was designed to detect deafness-causing variants in a multiethnic cohort with ARNSD by using whole-exome sequencing (WES). METHODS: After excluding mutations in the most common gene, GJB2, we performed WES in 160 multiplex families with ARNSD from Turkey, Iran, Mexico, Ecuador, and Puerto Rico to screen for mutations in all known ARNSD genes. RESULTS: We detected ARNSD-causing variants in 90 (56%) families, 54% of which had not been previously reported. Identified mutations were located in 31 known ARNSD genes. The most common genes with mutations were MYO15A (13%), MYO7A (11%), SLC26A4 (10%), TMPRSS3 (9%), TMC1 (8%), ILDR1 (6%), and CDH23 (4%). Nine mutations were detected in multiple families with shared haplotypes, suggesting founder effects. CONCLUSION: We report on a large multiethnic cohort with ARNSD in which comprehensive analysis of all known ARNSD genes identifies causative DNA variants in 56% of the families. In the remaining families, WES allows us to search for causative variants in novel genes, thus improving our ability to explain the underlying etiology in more families.Genet Med 18 4, 364-371.

Unique spectrum of GJB2 mutations in Mexico.

OBJECTIVE: The aim of this study was to elucidate the involvement of mutations in three relatively common deafness genes in Mexican individuals with non-syndromic hearing loss. METHODS: We sequenced GJB2 for mutations, screened for two deletions involving GJB6, del(GJB6-D13S1830) and del(GJB6-D13S1854), and for the m.1555A>G mutation in the MTRNR1 gene in 76 (71 simplex and 5 multiplex) unrelated Mexican probands with prelingual non-syndromic hearing loss. Samples were obtained from the Department of Genetics at Instituto Nacional de Rehabilitacion in Mexico City. RESULTS: Eight previously reported pathogenic variants and two polymorphic variants in GJB2 were identified. The two screened GJB6 deletions and the m.1555A>G mutation were not detected. Eight cases (10.6%) were found to have bi-allelic mutations in GJB2 and six (7.9%) were found to have a monoallelic GJB2 mutation. Of the six monoallelic mutations, one (p.R184Q) was a previously reported autosomal dominant variant. The most frequent pathological allele detected in this population was the c.35delG mutation in the GJB2 gene. The p.V27I polymorphic variant was also detected, with an allele frequency of 0.24. All eight probands with GJB2 mutations had symmetric profound deafness, whereas patients without GJB2 mutations had moderate, severe or profound hearing loss. CONCLUSIONS: This study shows that GJB2 mutations are an important cause of prelingual deafness in the Mexican population.

Saccharomyces cerevisiae Bat1 and Bat2 aminotransferases have functionally diverged from the ancestral-like Kluyveromyces lactis orthologous enzyme.

BACKGROUND: Gene duplication is a key evolutionary mechanism providing material for the generation of genes with new or modified functions. The fate of duplicated gene copies has been amply discussed and several models have been put forward to account for duplicate conservation. The specialization model considers that duplication of a bifunctional ancestral gene could result in the preservation of both copies through subfunctionalization, resulting in the distribution of the two ancestral functions between the gene duplicates. Here we investigate whether the presumed bifunctional character displayed by the single branched chain amino acid aminotransferase present in K. lactis has been distributed in the two paralogous genes present in S. cerevisiae, and whether this conservation has impacted S. cerevisiae metabolism. PRINCIPAL FINDINGS: Our results show that the KlBat1 orthologous BCAT is a bifunctional enzyme, which participates in the biosynthesis and catabolism of branched chain aminoacids (BCAAs). This dual role has been distributed in S. cerevisiae Bat1 and Bat2 paralogous proteins, supporting the specialization model posed to explain the evolution of gene duplications. BAT1 is highly expressed under biosynthetic conditions, while BAT2 expression is highest under catabolic conditions. Bat1 and Bat2 differential relocalization has favored their physiological function, since biosynthetic precursors are generated in the mitochondria (Bat1), while catabolic substrates are accumulated in the cytosol (Bat2). Under respiratory conditions, in the presence of ammonium and BCAAs the bat1Δ bat2Δ double mutant shows impaired growth, indicating that Bat1 and Bat2 could play redundant roles. In K. lactis wild type growth is independent of BCAA degradation, since a Klbat1Δ mutant grows under this condition. CONCLUSIONS: Our study shows that BAT1 and BAT2 differential expression and subcellular relocalization has resulted in the distribution of the biosynthetic and catabolic roles of the ancestral BCAT in two isozymes improving BCAAs metabolism and constituting an adaptation to facultative metabolism.

Diagnóstico del sistema de manejo de desechos sólidos generados en el Hospital “Dr. Julio Criollo Rivas” / Evaluation of the solid waste management program of the Dr. Julio Criollo Rivas Hospital

Los Desechos Sólidos Hospitalarios (DSH), contienen agentes patógenos o infecto-contagiosos, que representan un riesgo potencial para el personal que labora en las instituciones de salud, los pacientes y público en general. En consecuencia, el presente estudio tiene por finalidad diagnosticar la situación actual del manejo de los desechos sólidos generados en el Hospital “Dr. Julio Criollo Rivas”, en Ciudad Bolívar - estado Bolívar, durante el último semestre del año 2007, a través de una investigación descriptiva prospectiva, mediante encuestas al personal de enfermería y saneamiento ambiental, visitas aleatorias en los diferentes turnos de trabajo, además de la tabulación sistemática y registro fotográfico; así como la aplicación de listas de verificación para determinar el nivel de eficiencia que presenta el centro hospitalario acerca del manejo de estos desechos. Se determinó que todas las áreas del Hospital generan los cinco tipo de desechos según la normativa legal vigente (A, B, C, D y E), establecida en el Decreto 2.218 “Normas para la Clasificación y Manejo de Desechos en Establecimientos de Salud”, del cual sólo se cumple 29,17%. Sin embargo, 49,06% del personal de enfermería y 45,83%, del personal de saneamiento ambiental, poseen un nivel de conocimiento “Aceptable” acerca del manejo de los DSH. No obstante, la situación actual acerca de la manipulación de los mismos es “Deficiente”, por ello, se deduce la necesidad de plantear e implementar un orden de procedimientos para el manejo de los DSH factible desde el punto de vista sanitario, económico y operativo, y así lograr cumplir con la normativa legal vigente y disminuir el riesgo de enfermedades infectocontagiosas, accidentes laborales y contaminación ambiental.

Hospital solid waste (HSW) contains pathogenic or infecteious agents, representing a potential hazard for healthcare workers, patients and the general public. The present study examined current waste management policies and practices at the “Dr. Julio Criollo Rivas” Hospital, Bolívar City, Bolívar state, during the last semester of 2007, using a descriptive and prospective design that included surveys of nursing and housekeeping personnel, random visits during different work shifts, systematic tabulation, photographic recording and use of checklists to determine the hospital’s efficiency level regarding handling of wastes. Five types of hospital waste were identified (A, B, C, D and E, according to the current legal norm, Decree 2.218 “Rules for classification and handling of waste handling from health establishments”), butonly 29,17% of these rules were being complied with. However, 49,06% and 45,83% of nursing and housekeeping personnel, respectively, exhibited an “acceptable” level of knowledge regarding HSW handling. Nevertheless, the actual practices with HSW handling were rated as “deficient”. Consequently, there is a need to propose and implement HSW policies and procedures that are feasible from health, economic and operational standpoints, so that there is compliance with the law, and environmental and occupational risks are reduced.

Diversidad y distribución de palmas (Arecaceae) en tres fragmentos de bosque muy húmedo en Costa Rica / Palm (Arecaceae) diversity and distribution in three humid forest fragments in Costa Rica

Palm (Arecaceae) diversity and distribution in three humid forest fragments in Costa Rica. To determine the existing differences between species composition of palms in forest fragments with different disturbance regimes, three forest fragments at "El Zota", Cariari de Guápiles, Costa Rica, were chosen according to their disturbance level: 1) Disturbed primary forest (B1-i), 2) Secondary forest (B2) and 3) Primary forest (B1). A field survey was carried out in nested plots, where palms were identified and counted according to three size categories: i) 0.15 m to 1.35 m ii) 1.35 m to 5 m and iii) more than 5 m in height. The diversity found in B1 and B1-i is very similar, meanwhile the B2 has the lowest diversity. Palm abundance and distribution were influenced by the level of disturbance of the fragment. The B1-i presents the higher diversity in the first size categories, while B1 has the highest abundance of palms over 5 m tall. Rev. Biol. Trop. 57 (Suppl. 1): 83-92. Epub 2009 November 30.

Para determinar las diferencias existentes entre la composición de especies de palmas en fragmentos de bosque con diversos grados de alteración, se escogieron tres fragmentos en "El Zota", Costa Rica, según el grado de alteración: 1) Bosque primario alterado (B1-i), 2) Bosque secundario (B2) y 3) Bosque primario (B1). Se hizo un muestreo con parcelas anidadas donde se identificaron y contabilizaron las palmas según tres categorías de tamaño: i) 0.15 m a 1.35 m, ii) 1.35 m a 5 m y iii) más de 5 m de alto. Se observó que la diversidad de B1 y B1-i es muy similar, mientras que B2 posee la menor diversidad. La abundancia y distribución de las palmas estaba influenciada por el nivel de alteración del fragmento. El B1-i presenta una mayor diversidad de la primera categoría de tamaño, mientras que B1 tiene mayor abundancia de palmas sobre 5 m de alto.

The zebrafish mutant vps18 as a model for vesicle-traffic related hypopigmentation diseases.

Hypopigmentation is a characteristic of several diseases associated with vesicle traffic defects, like the Hermansky-Pudlak, Chediak-Higashi, and Griscelli syndromes. Hypopigmentation is also a characteristic of the zebrafish mutant vps18(hi2499A), which is affected in the gene vps18, a component of the homotypic fusion and protein sorting complex that is involved in tethering during vesicular traffic. Vps18, as part of this complex, participates in the formation of early endosomes, late endosomes, and lysosomes. Here, we show that Vps18 is also involved in the formation of melanosomes. In the zebrafish mutant vps18(hi2499A) the retroviral insertion located at exon 4 of vps18, leads to the formation of two abnormal splicing variants lacking the coding sequence for the clathrin repeat and the RING finger conserved domains. A deficiency of Vps18 in zebrafish larvae results in hepatomegaly and skin hypopigmentation. We also observed a drastic reduction in the number of melanosomes in the eye's retinal pigmented epithelium along with the accumulation of immature melanosomes. A significant reduction in the vps18(hi2499A) larvae visual system capacity was found using the optokinetic response assay. We propose that the insertional mutant vps18(hi2499A) can be used as a model for studying hypopigmentation diseases in which vesicle traffic problems exist.

Desmoplastic fibroma-like tumor of maxillofacial region associated with tuberous sclerosis.

Desmoplastic fibroma is a rare primary tumor of bone that histologically and biologically mimics the extra-abdominal desmoid tumor of soft tissue. It usually presents in patients during the first three decades of life and often involves the mandible or long bones of the skeleton. Its clinical behavior is characterized by a locally aggressive, infiltrating, and destructing course, often with invasion of surrounding tissues but without metastasis. We present herein the clinicopathological features of a desmoplastic fibroma-like tumor involving the left maxillofacial region in a 14-year-old Hispanic boy with tuberous sclerosis.

Complicaciones agudas de la enfermedad diverticular / Acute complications of diverticular disease

Evaluar los resultados del tratamiento médico y quirúrgico, y los factores que afectan la morbimortalidad. Estudio retrospectivo, pacientes con diagnóstico de enfermedad diverticular colónica complicada ingresados a la emergencia del Hospital "Dr. Miguel Pérez Carreño" entre noviembre de 1997 y diciembre de 2002, se analizan variables clínicas, paraclínicas y terapéuticas. Un total de 99 pacientes, edad media 72 años, 52 (53 por ciento) del sexo masculino y 47 (47 por ciento) féminas. Motivo de consulta más frecuente dolor abdominal 54 (55 por ciento), y sangrado rectal 51 (52 por ciento), 80 (81 por ciento) pacientes era su primer episodio, 55 (54 por ciento) tenían enfermedades médicas importantes asociadas. Se reliazron 70 colonoscopias, 28 ecos abdominopélvicos, y 12 tomografías. La enfermedad se localizó: colon izquierdo 66 pacientes (43 en el sigmoides exclusivamente), 28 enfermedad universal, 2 colon descendente y transverso, 3 en el colon derecho. Tratamiento médico 83 (84 por ciento) pacientes, cirugía 16 (16 por ciento): 8 sigmoidectomías, siete hemicolectomías, 1 colectomía total, 6 anastomosis primarias con fugas, la cirugía se indicó por hemorragia en 5 y diverticultis en 11. Medida de hospitalización 8 días, evolución tórpida en 12 (12 por ciento), fallecieron 5 (5 por ciento) todos con diagnóstico de hemorragia y enfermedades asociadas, media de 84 años, 4 con anemia severa, 3 oligúricos e hipotensos. El tratamiento médico es de elección en los pacientes con episodios agudos, sólo un número reducido amerita cirugía. La cirugía en 2 etapas es segura. Las enfermedades asociadas, media de 84 años, 4 con anemia severa aumentan la mortalidad