Lesión traqueal con reparación de colgajo muscular / Tracheal Injury with Muscle Flap Repair

RESUMEN Los traumatismos en cuello se pueden clasificar las lesiones en contusas y penetrantes, en el caso de las heridas penetrantes las ocasionadas por arma punzocortante son las más frecuentes. Las manifestaciones clínicas dependen del mecanismo del trauma, tamaño y nivel de la lesión. Paciente masculino de 26 años de edad con heridas por arma punzocortante en cuello y muñecas se ingresó a quirófano de urgencia, se realizó una exploración vascular de cuello encontrando una avulsión completa del ligamento cricotiroideo, se realizó la reparación del defecto con un colgajo de los músculos cricotiroideos, cursando una buena evolución es egresado al duodécimo día. El diagnóstico de las lesiones traqueales es desafiante y debe realizase rápidamente. Se debe instalar una vía aérea definitiva de manera eficaz y planear la reconstrucción quirúrgica. El seguimiento postoperatorio realizado de manera interdisciplinaria es esencial para el pronóstico(AU)

ABSTRACT Neck injuries can be classified as blunt or penetrating injuries. Penetrating injuries caused by a puncturing gun are the most frequent. The clinical manifestations depend on trauma mechanism, and on lesion size and degree. We present the case of a 26-year-old male patient with puncture injuries to the neck and wrists. After he was admitted to the emergency room, a vascular exploration of the neck was performed, finding a complete avulsion of the cricothyroid ligament. The defect was repaired with a flap of the cricothyroid muscles. The patient had a good evolution and was discharged on the twelfth day. The diagnosis of tracheal lesions is challenging and must be carried out quickly. A definitive airway should be installed efficiently, as well as the planning of the surgical reconstruction. The postoperative follow-up performed in an interdisciplinary way is essential for the prognosis(AU)

Apendagitis epiplóica primaria / Primary epiploic appendagitis

RESUMEN La apendagitis epiploica primaria es una rara causa de dolor abdominal que puede simular cualquier otro cuadro de abdomen agudo. Esto hace de su diagnóstico un verdadero desafío. Se presenta el caso de un paciente masculino de 22 años de edad, sin antecedentes de importancia que ingresó a la sala de emergencias con un cuadro de dolor abdominal de 36 horas de evolución. En la exploración física presentó dolor a la palpación en el flanco derecho. Se le realizó una tomografía axial de abdomen contrastada en la cual se observó una imagen redondeada con un halo hiperdenso con borramiento de planos grasos y cambios inflamatorios a su alrededor sin relación a otro órgano abdominal. Con estos hallazgos hicimos el diagnóstico de una apendagitis epiploica primaria. El paciente fue ingresado a la sala de internamiento para manejo del dolor y con mejoría clínica es egresado a las 48 horas asintomático. Si bien la apendagitis epiploica primaria es una causa infrecuente de dolor abdominal, consideramos que su conocimiento es relevante para evitar errores diagnósticos y terapéuticos que incrementan de forma innecesaria la morbilidad como el uso inadecuado de antibióticos y de recursos hospitalarios(AU)

ABSTRACT Primary epiploic appendagitis is a rare cause of abdominal pain that may mimic any other acute abdomen condition. This makes its diagnosis a real challenge for physicians. Here is a 22 years-old male patient, with no significant history of diseases, who were admitted to the emergency room because he had suffered abdominal pain for 36 hours. The physical exam revealed pain on palpating the right flank. He underwent a contrasted computed tomography of abdomen which showed a rounded image with hyperdense halo, fat plane effacement and inflammatory changes around, which was unrelated to another abdominal organ. These findings allowed diagnosing primary epiploic appendagitis. The patient was hospitalized for pain management and was discharged 48 hours later with clinical improvement and no symptoms. Primary epiploic appendagitis is infrequent cause of abdominal pain, however, we consider that it is important to know it so as to avoid diagnostic and therapeutic mistakes that might unnecessarily increase morbidity and the inadequate use of antibiotics and of hospital resources(AU)

Asociación de invaginación y malrotación intestinal con el Síndrome de Waugh / Association of invagination and intestinal malrotation with Waugh's síndrome

RESUMEN El síndrome de Waugh es una patología del neonato caracterizado por la asociación de una malrotación intestinal a una intususcepción. Existen pocos casos documentados en la literatura, lo que conlleva una baja incidencia. Presentamos el caso de un neonato femenino de 4 meses de edad quien fue llevada a tratamiento quirúrgico con oclusión intestinal y evolución posoperatoria favorable. El objetivo del trabajo es presentar el caso de un síndrome de Waugh en un lactante en cuyo cuadro se debe mantener una alta sospecha diagnostica, apoyándose con la toma de estudios de imagen complementarios ante un cuadro de dolor abdominal en pacientes lactantes cuya resolución diagnostica siempre resulta un reto para el médico. Si bien estas acciones podrán en un futuro reflejar un aumento en la incidencia de este síndrome, también es posible que el manejo de dicho síndrome se optimice. Paciente femenina de 4 meses de edad la cual fue sometida a tres intentos de desinvaginación hidrostática antes de pasar a laparotomía exploradora para corrección definitiva de su patología. La asociación de invaginación con mal rotación intestinal actualmente es subdiagnósticada, debido a la tendencia conservadora actual. Es importante realizar más estudios de imagen antes de iniciar con cualquier estrategia terapéutica, para no retrasar el manejo quirúrgico definitivo que este requiere. De esta manera se podrá ganar en la calidad de los pronósticos de los pacientes(AU)

ABSTRACT Waugh's syndrome is a neonatal pathology characterized by the association of intestinal malrotation and intussusception. There is a low number of cases documented in literature, which implies low incidence. Here is a 4 months-old female neonate who was surgically treated because of intestinal occlusion, and her postoperative recovery was favorable. The objective was to present a Waugh's syndrome case in a newborn in which high diagnostic suspicion is important, supported by complementary imaging studies when we face abdominal pain in neonates whose diagnostic resolution is always a challenge to the physician. These actions may show an increase in the incidence of this syndrome in the future; it is also possible that the management of this disease be optimized. Hydrostatic disinvagination was performed three times in this patient before undergoing exploratory laparotomy for final correction of her pathology. The association of invagination and intestinal malrotation is poorly diagnosed at present, due to current conservative tendencies. However, it is important to perform more imaging studies before adopting any therapeutic strategy to avoid delays in the definitive surgical management of this disease(AU)

Schwannoma de retroperitoneo asociado a Neurofibromatosis tipo I / Retroperitoneal Schannoma associated to type I neurofibromatosis

RESUMEN Los Schwannomas son tumores de origen neural, corresponden al 1 por ciento de los tumores de retroperitoneo. En la mayoría de las ocasiones, son tumores de comportamiento benigno, encontrando que solo del 5 - 18 por ciento son malignos y aún menos frecuente es que sean de alto grado en su histología. Se trata de una paciente de 46 años de edad sin antecedentes crónico degenerativos. Con diagnóstico conocido de neurofibromatosis tipo I. Inició su padecimiento actual tres años previos a su ingreso en 2013, al presentar artralgia de rodilla derecha la cual se asocia a mialgias de forma ipsilateral. Se le solicitó como apoyo diagnostico una resonancia magnética de columna dorsal y lumbar, en la que se reporta una tumoración en la región del retroperitoneo de lado derecho con medidas de 10 x 17 cm con aparente origen espinal en L2 y L3. A pesar de ser masas de origen neural benignas la mayoría de las veces, no es infrecuente su malignización encontrando una cavidad con estructuras vecinas tomada por el tumor. En estos casos, es de vital importancia el manejo preoperatorio de manera multidisciplinaria tanto en la preparación preoperatoria, así como durante el procedimiento quirúrgico(AU)

ABSTRACT Schwannomas are tumors of neural origin and account for 1 percent of retroperitoneal tumors. In many times, they are benign tumors and just 5 to 8 percent are malignant; high degree is even less frequent in its histology. This is a male patient aged 46 years with no history of chronic degenerative problems and diagnosis of type I neurofibromatosis. The disease appeared three years before his admission to hospital in 2013 because of right knee arthralgia associated to myalgias on the same side. Diagnostic support was requested in terms of performance of magnetic resonance of dorsal and lumbar spine; this test reported the presence of a tumor in the right side of the retroperitoneal region, it measured 10 x 17 cm with apparent spinal origin in L2 and L3. Although they are often masses of benign neural origin, their malignization is not rare. There was a cavity with adjoining structures affected by the tumor. In this type of cases, the preoperative management with multidisciplinary involvement both in the preoperative preparation and during the surgical procedure is of vital importance(AU)

[Primary biliary cholangitis. Part 2. State of the art, diagnosis, associated diseases, treatment and prognosis]. / Colangitis biliar primaria. Parte 2. Actualización: diagnóstico, enfermedades asociadas, tratamiento y pronóstico.

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy characterized by a selective destruction of biliary epithelial cells of small and medium caliber hepatic ducts, which mainly affects women. The main symptoms are fatigue and pruritus, however, a large proportion of patients may be asymptomatic. The diagnosis is based on AMA titers >1:40, alkaline phosphatase >1.5 times the upper limit for more than 24 weeks and compatible liver histology. It is associated with multiple autoimmune diseases mainly extrahepatic, thyroid diseases, bone diseases, among others. The first line treatment is ursodeoxycholic acid (UDCA), that improves liver function tests and delay the progression to cirrhosis. Currently, there are new treatments and adjuvant therapies on study. The purpose of this review is to offer an update in this topic, which is very important in gastroenterology and internal medicine. We formed an interdisciplinary team to search in the data base Medline thorough PubMed with the keywords describe below, we made a critical lecture of the titles and abstracts of each article to write this paper.

Colangitis biliar primaria. Parte 2. Actualización: diagnóstico, enfermedades asociadas, tratamiento y pronóstico / Primary Biliary Cholangitis. Part 2. State of the Art, Diagnosis, Associated Diseases, Treatment and Prognosis

La colangitis biliar primaria (CBP), es una colangiopatía crónica caracterizada por la destrucción selectiva de las células epiteliales biliares de conductos hepáticos de pequeño y mediano calibre, que afecta principalmente a mujeres. Los principales síntomas son la fatiga y el prurito, sin embargo, gran porcentaje de los pacientes pueden ser asintomáticos. El diagnóstico se basa en anticuerpos antimitocondriales (AMA) con títulos >1:40, fosfatasa alcalina >1,5 veces del límite superior normal por más de 24 semanas e histología hepática compatible con la patología. Se asocia con múltiples enfermedades principalmente de carácter autoinmune extra hepáticas, enfermedades tiroideas, óseas, entre otras. El tratamiento de primera línea es el ácido ursodesoxicólico (AUDC) que a pesar que no cura la enfermedad, mejora las pruebas del perfil hepático, así como el retraso en la progresión a cirrosis. Actualmente se encuentran en estudio nuevos tratamientos y terapias adyuvantes. El propósito de esta revisión es ofrecer una actualización de este tema que se presenta en los servicios de medicina interna y gastroenterología; para su realización se conformó un equipo interdisciplinar que desarrolló una búsqueda en la base Medline a través de PubMed con los tesauros correspondientes y se procedió a una lectura crítica y analítica de títulos, resúmenes y textos completos para el filtro, extracción y síntesis de la información encontrada

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy characterized by a selective destruction of biliary epithelial cells of small and medium caliber hepatic ducts, which mainly affects women. The main symptoms are fatigue and pruritus, however, a large proportion of patients may be asymptomatic. The diagnosis is based on AMA titers >1:40, alkaline phosphatase >1.5 times the upper limit for more than 24 weeks and compatible liver histology. It is associated with multiple autoimmune diseases mainly extrahepatic, thyroid diseases, bone diseases, among others. The first line treatment is ursodeoxycholic acid (UDCA), that improves liver function tests and delay the progression to cirrhosis. Currently, there are new treatments and adjuvant therapies on study. The purpose of this review is to offer an update in this topic, which is very important in gastroenterology and internal medicine. We formed an interdisciplinary team to search in the data base Medline thorough PubMed with the keywords describe below, we made a critical lecture of the titles and abstracts of each article to write this paper

Perforación de ciego por colitis isquémica asociada a uso de cocaína: reporte de caso / Perforation of the cecum by isquemic colitis associated with cocaine use: a case report

Introducción: El consumo de cocaína es un problema mayor a nivel mundial; los usuarios crónicos presentan complicaciones médicas graves que afectan el aparato vascular, los cuales puedenderivar en accidentes isquémicos serios. A continuación presentamos un caso de perforación intestinal secundaria a colitis isquémica por uso de cocaína. Caso clínico: Un hombre de 21 anos de edad con antecedente de uso de cocaína inició su pade cimiento 5 días antes de su ingreso con dolor abdominal, náuseas y vómitos. Con el diagnóstico de perforación de víscera hueca se realizó una laparotomía exploradora, en la cual se encontró una perforación en la cara anterior del ciego. Se realizó una hemicolectomía derecha con una ileostomía y una fístula mucocutánea de colon transverso. Discusión: La causa de las perforaciones es la isquemia local en la mucosa y la necrosis parietal. En este paciente obtuvimos una prueba de orina positiva para cocaína; además, con el ante cedente de uso intenso de esta sustancia y el resultado en el reporte histopatológico pudimos llegar a este diagnóstico. Conclusión: La colitis isquémica asociada a uso de cocaína debe ser considerada como diagnós tico diferencial en pacientes jóvenes con dolor abdominal agudo y/o sangrado rectal.

Introduction: Cocaine use is a major problem worldwide. Chronic users have serious medical complications that affect the vascular system, which can lead to serious ischemic events. We describe a case of intestinal perforation secondary to ischemic colitis caused by cocaine. Case report: A 21-year-old man with a history of cocaine started 5 days before with abdominal pain, nausea and vomiting. With a diagnosis of a perforated intestine, a exploratory laparo tomy was performed, in which a perforation of the anterior wall of the cecum was found. A right hemicolectomy with ileostomy and a mucocutaneous fistula of the transverse colon were carried out. Discussion: Perforations are caused by local ischemia of the mucosa and parietal necrosis. In this patient, a urine test for cocaine was positive, in addition to the history of intensive use of this substance and a pathology report. Conclusion: Ischemic colitis associated with cocaine use should be considered as a differential diagnosis in young patients with acute abdominal pain and/or rectal bleeding.

Sugary drinks taxation, projected consumption and fiscal revenues in Colombia: Evidence from a QUAIDS model.

The global shift towards diets high in sugar-sweetened beverages (SSBs) is linked to higher prevalence of obesity, diabetes and most other non-communicable diseases. In Colombia, one out of every two people was overweight or obese by 2010. This study estimates price-elasticities from a Quadratic Almost Ideal Demand System model, using the 2006-2007 Colombian Income and Expenditure survey. The food groups that were jointly considered were: unsweetened unflavored milks; coffee and tea; sugar sweetened beverages (SSBs); sweets and candies (including sugar); dairy products; meats and animal-based products; grains based staples; fruits and vegetables; and condiments and snacks. We take into account the high proportion of households not purchasing specific food and beverage groups (censored data) and endogeneity on both prices (as unit values) and total expenditure. Unhealthy beverages are price-elastic (-1.61 for SSBs) meaning that the change in consumption is proportionally larger with respect to a change in price. Also, there is a high complementarity among SSBs and major food groups (grains, meats and fruits and vegetables). In Colombia, the design of a meaningful tax to influence healthier diets is a next critical step. This study also shows that a tax of 20% on SSBs should prove to be effective, and can yield revenues of about 1% of the Colombian government's total annual fiscal revenue, which can potentially be directed towards public health promotion and investments.

Colangitis biliar primaria. Parte 1. Actualización: generalidades, epidemiología, factores involucrados, fisiopatología y manifestaciones clínicas / Primary biliary cholangitis. Part 1. State of the art, epidemiology, physiopathology and clinical manifestations

La colangitis biliar primaria (CBP), es una colangiopatía crónica caracterizada por la destrucción selectiva de las células epiteliales biliares de conductos hepáticos de pequeño y mediano calibre, que afecta principalmente a mujeres. Los principales síntomas son la fatiga y el prurito, sin embargo, gran porcentaje de los pacientes pueden ser asintomáticos. El diagnóstico se basa en anticuerpos antimitocondriales (AMA) con títulos >1:40, fosfatasa alcalina >1,5 veces del límite superior normal por más de 24 semanas e histología hepática compatible con la patología. Se asocia con múltiples enfermedades principalmente de carácter autoinmune extra hepáticas, enfermedades tiroideas, óseas, entre otras. El tratamiento de primera línea es el ácido ursodesoxicólico (AUDC) que a pesar que no cura la enfermedad, mejora las pruebas del perfil hepático, así como el retraso en la progresión a cirrosis. Actualmente se encuentran en estudio nuevos tratamientos y terapias adyuvantes. El propósito de esta revisión es ofrecer una actualización de este tema que se presenta en los servicios de medicina interna y gastroenterología; para su realización se conformó un equipo interdisciplinario que desarrolló una búsqueda en la base Medline a través de PubMed con las palabras claves correspondientes y se procedió a una lectura crítica y analítica de títulos, resúmenes y textos completos para el filtro, extracción y síntesis de la información encontrada

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy characterized by a selective destruction of biliary epithelial cells of small and medium caliber hepatic ducts, which mainly affects women. The main symptoms are fatigue and pruritus, however, a large proportion of patients may be asymptomatic. The diagnosis is based on AMA titers >1:40, alkaline phosphatase >1.5 times the upper limit for more than 24 weeks and compatible liver histology. It is associated with multiple autoimmune diseases mainly extrahepatic, thyroid diseases, bone diseases, among others. The first line treatment is ursodeoxycholic acid (UDCA), that improves liver function tests and delay the progression to cirrhosis. Currently, there are new treatments and adjuvant therapies on study. The purpose of this review is to offer an update in this topic, which is very important in gastroenterology and internal medicine. We formed an interdisciplinary team to search in the database Medline thorough PubMed with the key words describe below, we made a critical lecture of the titles and abstracts of each article to write this paper

[Primary biliary cholangitis. Part 1. State of the art, epidemiology, physiopathology and clinical manifestations]. / Colangitis biliar primaria. Parte 1. Actualización: generalidades,epidemiología, factores involucrados, fisiopatología y manifestaciones clínicas.

Primary biliary cholangitis (PBC) is a chronic autoimmune cholangiopathy characterized by a selective destruction of biliary epithelial cells of small and medium caliber hepatic ducts, which mainly affects women. The main symptoms are fatigue and pruritus, however, a large proportion of patients may be asymptomatic. The diagnosis is based on AMA titers >1:40, alkaline phosphatase >1.5 times the upper limit for more than 24 weeks and compatible liver histology. It is associated with multiple autoimmune diseases mainly extrahepatic, thyroid diseases, bone diseases, among others. The first line treatment is ursodeoxycholic acid (UDCA), that improves liver function tests and delay the progression to cirrhosis. Currently, there are new treatments and adjuvant therapies on study. The purpose of this review is to offer an update in this topic, which is very important in gastroenterology and internal medicine. We formed an interdisciplinary team to search in the database Medline thorough PubMed with the key words describe below, we made a critical lecture of the titles and abstracts of each article to write this paper.

Quality of dry-cured ham compared with quality of dry-cured shoulder.

The physicochemical and sensory properties of 30 dry-cured hams and 30 dry-cured shoulders were analyzed to determine the relationships between them. The variables used to characterize both products were: compositional parameters, instrumental texture, amino acid and fatty acid composition, and sensory profile. Despite being products from the same animal and composed mainly of fat, lean, and bone, their morphological differences determine the conditions of the processing time, which produced differences between products in most of the parameters evaluated. Dry-cured shoulders showed lower moisture content and greater instrumental hardness due to their morphology and muscular structure. Besides, these samples showed lower amino acid content according to the shorter ripening time. For the same reason, the dry-cured hams showed higher moisture content, lower instrumental hardness, and higher amino acid content. However, the differences in the muscular structure did not affect the sensory characteristics, which were more related with some compositional parameters, such as chloride, moisture, and amino acid content and with the length of the curing process.

Bacterial-type oxygen detoxification and iron-sulfur cluster assembly in amoebal relict mitochondria.

The assembly of vital reactive iron-sulfur (Fe-S) cofactors in eukaryotes is mediated by proteins inherited from the original mitochondrial endosymbiont. Uniquely among eukaryotes, however, Entamoeba and Mastigamoeba lack such mitochondrial-type Fe-S cluster assembly proteins and possess instead an analogous bacterial-type system acquired by lateral gene transfer. Here we demonstrate, using immunomicroscopy and biochemical methods, that beyond their predicted cytosolic distribution the bacterial-type Fe-S cluster assembly proteins NifS and NifU have been recruited to function within the relict mitochondrial organelles (mitosomes) of Entamoeba histolytica. Both Nif proteins are 10-fold more concentrated within mitosomes compared with their cytosolic distribution suggesting that active Fe-S protein maturation occurs in these organelles. Quantitative immunoelectron microscopy showed that amoebal mitosomes are minute but highly abundant cellular structures that occupy up to 2% of the total cell volume. In addition, protein colocalization studies allowed identification of the amoebal hydroperoxide detoxification enzyme rubrerythrin as a mitosomal protein. This protein contains functional Fe-S centres and exhibits peroxidase activity in vitro. Our findings demonstrate the role of analogous protein replacement in mitochondrial organelle evolution and suggest that the relict mitochondrial organelles of Entamoeba are important sites of metabolic activity that function in Fe-S protein-mediated oxygen detoxification.

[Molecular characterization of heterozygous beta-thalassemia in Lanzarote, Spain]. / Caracterización molecular de la betatalasemia en Lanzarote.

BACKGROUND AND OBJECTIVE: The aim of this study was to determine the molecular defects of heterozygous beta thalassaemia and to ascertain their distribution in Lanzarote. PATIENTS AND METHOD: Molecular characterization was achieved by real time polymerase chain reaction (RT-PCR LightCycler, Roche), PCR-ARMS (PCR-amplification reaction mutations system) and DNA sequencing on an automated DNA sequencer. RESULTS: Two hundred forty-three heterozygous beta thalassaemia carriers were included between July 1991 and February 2007. RT-PCR detected the molecular defect in 81% of the beta thalassaemia chromosomes analyzed [113 codon CD 39 (C --> T); 41 IVS-1-nt-110 (G --> A), 25 IVS 1-nt-1 (G --> A) and 19 IVS 1-nt-6 (T --> C)]. The remaining 12 molecular defects included the deletion 619 bp (7.8%) and the mutations -28 (A --> G), IVS1-nt-2 (T --> G), CD 41/42 (-TTCT), CD 8/9 (+G), CD 51 (-C), CD 22 (G --> T) and CD 24 (T --> A), CD 67 (-TG) and the novel mutation CD 20/21-TGGA. CONCLUSIONS: The distribution of the mutations is similar to that found in the Mediterranean area. The increasing migratory flow received in the Canary Islands may explain the emergence of new mutations not reported before in our area.

Entamoeba histolytica mitosomes: organelles in search of a function.

It has been more than eight years since the discovery of mitosomes (mitochondrial remnant organelles) in the intestinal human pathogen Entamoeba histolytica. Despite detailed knowledge about the biochemistry of this parasite and the completion of the E. histolytica genome sequencing project no physiological function has yet been unequivocally assigned to these organelles. Entamoeba mitosomes seem to be the most degenerate of all endosymbiosis-derived organelles studied to date. They do not appear to participate in energy metabolism and may have dispensed completely with the proteins required for iron-sulphur cluster biosynthesis. However, the large number of mitosomes found in E. histolytica trophozoites hints at a significant biological role for these organelles in their natural environment. Identifying the protein complement of mitosomes will provide answers as to their biological significance and the reason(s) for their retention in this parasite.

A mitosome purification protocol based on percoll density gradients and its use in validating the mitosomal nature of Entamoeba histolytica mitochondrial Hsp70.

Mitochondria are indispensable for aerobic respiration, but many microbial eukaryotes have lost this function through reductive evolution. Their modified mitochondria are known as hydrogenosomes or mitosomes depending on whether or not they produce molecular hydrogen. The intestinal parasite Entamoeba histolytica contains mitosomes whose role in cellular metabolism is unclear. Only three proteins have been shown thus far to reside in these organelles: the molecular chaperones Hsp10 and Hsp60 and an unusual ADP/ATP carrier. Here we describe the isolation of E. histolytica mitosomes by cellular fractionation and density gradient centrifugation and show that the mitochondrial-type chaperone Hsp70 is also housed in Entamoeba mitosomes.

Aspectos biomédicos de la familia de las lipocalinas / Biomedical Aspects of the Lipocalines Family

La familia de las proteínas lipocalinas está compuesta de varios miembros que comparten una estructura común, definida en general por la unión de ligandos lipofílicos. Se expresan en forma diferencial específica por células y tejidos, y tienen una función extracelular de transporte para las hormonas lipídicas, incluidas las hormonas tiroideas, las vitaminas lipídicas (complejo vitamínico A), los ácidos grasos, los ácidos biliares, el hierro, los agentes tóxicos y los agentes farmacológicos. Las lipocalinas están implicadas en la fisiología hematoinmune,en la neurofisiología, en la fisiología de la reproducción y la fertilidad, en la proliferación y división celular, en la supervivencia celular y la apoptosis, y en la función enzimática (biosíntesis de prostanglandina D2). El rol en patología y bioclínica se deriva a partir de las observaciones de que varias lipocalinas tienen alteraciones en sus niveles de expresión en diferentes trastornos. Esta revisión resume estos hallazgos y sus implicaciones.

Evidence from bioinformatics, expression and inhibition studies of phosphoinositide-3 kinase signalling in Giardia intestinalis.

BACKGROUND: Giardia intestinalis is a parasitic protozoan and major cause of diarrhoeal disease. Disease transmission is dependent on the ability of the parasite to differentiate back and forth between an intestine-colonising trophozoite and an environmentally-resistant infective cyst. Our current understanding of the intracellular signalling mechanisms that regulate parasite replication and differentiation is limited, yet such information could suggest new methods of disease control. Phosphoinositide-3 kinase (PI3K) signalling pathways have a central involvement in many vital eukaryotic processes, such as regulation of cell growth, intracellular membrane trafficking and cell motility. Here we present evidence for the existence of functional PI3K intracellular signalling pathways in G. intestinalis. RESULTS: We have identified and characterised two genes, Gipi3k1 and Gipi3k2, which encode putative PI3Ks. Both genes are expressed in trophozoites and encysting cells, suggesting a possible role of GiPI3K1 and GiPI3K2 in regulating giardial growth and differentiation. Extensive nucleotide and amino acid sequence characterisation predicts that both encoded PI3Ks are functional as indicated by the presence of highly conserved structural domains and essential catalytic residues. The inhibitory effect of the PI3K inhibitor LY294002 on trophozoite proliferation also supports their functionality. Phylogenetic analysis supports the identity of GiPI3K1 as a Class I isoform and GiPI3K2 as a Class III isoform. In addition, giardial genes encoding putative homologues of phosphoinositide-metabolising enzymes such as PTEN, MTM, PIPkin and PI 5-phosphatase as well as downstream effectors with phosphoinositide-binding domains have been identified, placing GiPI3K1 and GiPI3K2 in a broader signalling context. Compared with twenty-six PI3Ks from other organisms, GiPI3K1 and GiPI3K2 are unique in that they contain large insertions within their highly conserved kinase domains. The function of these insertions is unknown; however we show here that they are not intron-derived and would probably not hinder substrate binding. These insertions may represent a plausible drug target. CONCLUSION: G. intestinalis encodes and expresses two putative PI3Ks, at least one of which appears to be required during normal parasite proliferation. The identification of Class I and Class III but not Class II isoforms suggests that both extracellularly-initiated signalling (Class I-regulated) and intracellular vesicle trafficking (Class III-regulated) might be controlled by PI3Ks in G. intestinalis. The presence of genes encoding putative homologues of phosphoinositide-metabolising enzymes and downstream effectors in the G. intestinalis genome further suggests that the overall architecture of PI3K signalling may be comparable with pathways present in other better-studied organisms.

Characterization of chaperonin 10 (Cpn10) from the intestinal human pathogen Entamoeba histolytica.

Entamoeba histolytica is the causative agent of amoebiasis, a poverty-related disease that kills an estimated 100 000 people each year. E. histolytica does not contain "standard mitochondria", but harbours mitochondrial remnant organelles called mitosomes. These organelles are characterized by the presence of mitochondrial chaperonin Cpn60, but little else is known about the functions and molecular composition of mitosomes. In this study, a gene encoding molecular chaperonin Cpn10--the functional partner of Cpn60--was cloned, and its structure and expression were characterized, as well as the cellular localization of its encoded protein. The 5' untranslated region of the gene contains all of the structural promoter elements required for transcription in this organism. The amoebic Cpn10, like Cpn60, is not significantly upregulated upon heat-shock treatment. Computer-assisted protein modelling, and specific antibodies against Cpn10 and Cpn60, suggest that both proteins interact with each other, and that they function in the same intracellular compartment. Thus, E. histolytica appears to have retained at least two of the key molecular components required for the refolding of imported mitosomal proteins.

Mitochondrion-derived organelles in protists and fungi.

The mitochondrion is generally considered to be a defining feature of eukaryotic cells, yet most anaerobic eukaryotes lack this organelle. Many of these were previously thought to derive from eukaryotes that diverged prior to acquisition of the organelle through endosymbiosis. It is now known that all extant eukaryotes are descended from an ancestor that had a mitochondrion and that in anaerobic eukaryotes the organelle has been modified into either hydrogenosomes, which continue to generate energy for the host cell, or mitosomes, which do not. These organelles have each arisen independently several times. Recent evidence suggests a shared derived characteristic that may be responsible for the retention of the organelles in the absence of the better-known mitochondrial functions--iron-sulfur cluster assembly. This review explores the events leading to this new understanding of mitochondrion-derived organelles in amitochondriate eukaryotes, the current state of our knowledge, and future areas for investigation.

Protein import, replication, and inheritance of a vestigial mitochondrion.

Mitochondrial remnant organelles (mitosomes) that exist in a range of "amitochondrial" eukaryotic organisms represent ideal models for the study of mitochondrial evolution and for the establishment of the minimal set of proteins required for the biogenesis of an endosymbiosis-derived organelle. Giardia intestinalis, often described as the earliest branching eukaryote, contains double membrane-bounded structures involved in iron-sulfur cluster biosynthesis, an essential function of mitochondria. Here we present evidence that Giardia mitosomes also harbor Cpn60, mtHsp70, and ferredoxin and that despite their advanced state of reductive evolution they have retained vestiges of presequence-dependent and -independent protein import pathways akin to those that operate in mammalian mitochondria. Although import of IscU and ferredoxin is still reliant on their amino-terminal presequences, targeting of Giardia Cpn60, IscS, or mtHsp70 into mitosomes no longer requires cleavable presequences, a derived feature from their mitochondrial homologues. In addition, we found that division and segregation of a single centrally positioned mitosome tightly associated with the microtubular cytoskeleton is coordinated with the cell cycle, whereas peripherally located mitosomes are inherited into daughter cells stochastically.