RESUMEN
Pituitary adenomas are relatively common intracranial neoplasms that are frequently treated with surgical resection. Rapid visualization of pituitary tissue remains a challenge as current techniques either produce little to no information on hormone-secreting function or are too slow to practically aid in intraoperative or even perioperative decision-making. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) represents a powerful method by which molecular maps of tissue samples can be created, yielding a two-dimensional representation of the expression patterns of small molecules and proteins from biologic samples. In this chapter, we review the use of MALDI MSI, its application to the characterization of the pituitary gland, and its potential applications for guiding the management of pituitary adenomas.
Asunto(s)
Biomarcadores/metabolismo , Procesamiento de Imagen Asistido por Computador/métodos , Espectrometría de Masas/métodos , Imagen Molecular/métodos , Monitoreo Intraoperatorio/métodos , Neoplasias Hipofisarias/patología , Animales , Manejo de la Enfermedad , Humanos , Neoplasias Hipofisarias/metabolismo , Neoplasias Hipofisarias/cirugíaRESUMEN
Endometriosis is a common condition in women, whose main repercussions are painful symptoms. In addition, it was shown that endometriosis was a major cause of infertility and various obstetric complications could be related to this pathology. Uterine rupture is a rare but serious complication whose incidence tends to decrease with the screening of women at risk, however, its fetal, maternal morbidity and mortality causes remains important. We were confronted with a case of posterior uterine rupture in a patient of 36 years, primipare term exceeded in immediate postpartum period. The patient's primary antecedent of uterine surgery torus was responsible for infertility endometriosis. The outcome was favorable for the mother, after a surgical treatment by laparotomy, and for the child. In the literature, two cases have been reported of uterine rupture after endometriosis surgery, which is why we found it interesting to report this rare case. Given the increase in surgical management of this disease, it seems relevant to ask whether, in the future, we should be more vigilant in monitoring pregnancy for these women.
Asunto(s)
Endometriosis/cirugía , Procedimientos Quirúrgicos Ginecológicos/efectos adversos , Enfermedades del Recto/cirugía , Rotura Uterina/etiología , Enfermedades Vaginales/cirugía , Adulto , Femenino , Humanos , EmbarazoAsunto(s)
Muerte Fetal , Placenta Previa , Adulto , Parto Obstétrico/métodos , Femenino , Humanos , EmbarazoRESUMEN
Aberrant splicing of the cyclin-dependent kinase-associated phosphatase, KAP, promotes glioblastoma invasion in a Cdc2-dependent manner. However, the mechanism by which this occurs is unknown. Here we show that miR-26a, which is often amplified in glioblastoma, promotes invasion in phosphatase and tensin homolog (PTEN)-competent and PTEN-deficient glioblastoma cells by directly downregulating KAP expression. Mechanistically, we find that KAP binds and activates ROCK2. Thus, RNA-mediated downregulation of KAP leads to decreased ROCK2 activity and this, in turn, increases Rac1-mediated invasion. In addition, the decrease in KAP expression activates the cyclin-dependent kinase, Cdk2, and this directly promotes invasion by increasing retinoblastoma phosphorylation, E2F-dependent Cdc2 expression and Cdc2-mediated inactivation of the actomyosin inhibitor, caldesmon. Importantly, glioblastoma cell invasion mediated by this pathway can be antagonized by Cdk2/Cdc2 inhibitors in vitro and in vivo. Thus, two distinct RNA-based mechanisms activate this novel KAP/ROCK2/Cdk2-dependent invasion pathway in glioblastoma.
Asunto(s)
Quinasa 2 Dependiente de la Ciclina/metabolismo , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/metabolismo , Fosfatasas de Especificidad Dual/metabolismo , Glioblastoma/patología , MicroARNs/fisiología , Quinasas Asociadas a rho/metabolismo , Actomiosina/antagonistas & inhibidores , Neoplasias Encefálicas/patología , Proteína Quinasa CDC2 , Proteínas de Unión a Calmodulina/antagonistas & inhibidores , Línea Celular Tumoral , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 2 Dependiente de la Ciclina/genética , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/biosíntesis , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/genética , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/biosíntesis , Fosfatasas de Especificidad Dual/biosíntesis , Fosfatasas de Especificidad Dual/genética , Factores de Transcripción E2F/fisiología , Activación Enzimática , Humanos , MicroARNs/antagonistas & inhibidores , MicroARNs/genética , Invasividad Neoplásica , Fosfohidrolasa PTEN/metabolismo , Fosforilación , Unión Proteica , Interferencia de ARN , ARN Interferente Pequeño , Proteína de Retinoblastoma/metabolismo , Proteína de Unión al GTP rac1/fisiologíaRESUMEN
Uterine torsion is a rare obstetrical complication whose diagnosis remains challenging. We report a case of 180 degrees dextrogyre torsion at 36(+5) weeks of gestation complicated by partial abruption and in utero fetal death. Emergency cesarean section was performed through an unintentional posterior hysterotomy. Literature reports a few similar cases. Vertical hysterotomy should be advised in this context avoiding incision on lateral sides associated with increased risk of vascular or ureteral injury.
Asunto(s)
Desprendimiento Prematuro de la Placenta , Muerte Fetal , Complicaciones del Embarazo , Anomalía Torsional/complicaciones , Enfermedades Uterinas/complicaciones , Adulto , Cesárea/métodos , Tratamiento de Urgencia , Femenino , Edad Gestacional , Humanos , Histerotomía , EmbarazoRESUMEN
BACKGROUND: There is no prognostic index for primary cutaneous T-cell lymphomas such as mycosis fungoides (MF) and Sezary syndrome (SS). METHOD: Two prognostic indices were developed for early (IA-IIA) and late stage (IIB-IVB) disease based on multivariate data from 1502 patients. End-points included overall survival (OS) and progression free survival (PFS). External validation included 1221 patients. FINDINGS: Significant adverse prognostic factors at diagnosis consisted of male gender, age >60, plaques, folliculotropic disease and stage N1/Nx for early stage, and male gender, age >60, stages B1/B2, N2/3 and visceral involvement for late stage disease. Using these variables we constructed two separate models each defined using 3 distinct groups for early and late stage patients: 0-1 (low risk), 2 (intermediate risk), and 3-5 factors (high risk). 10 year OS in the early stage model was 90.3% (low), 76.2% (intermediate) and 48.9% (high) and for the late stage model 53.2% (low), 19.8% (intermediate) and 15.0% (high). For the validation set significant differences in OS and PFS in early stage patients (both p<0.001) were also noted. In late stage patients, only OS differed between the groups (p=0.002). INTERPRETATION: This proposed cutaneous lymphoma prognostic index provides a model for prediction of OS in early and late stage MF/SS enabling rational therapeutic choices and patient stratification in clinical trials.
Asunto(s)
Micosis Fungoide/diagnóstico , Síndrome de Sézary/diagnóstico , Neoplasias Cutáneas/diagnóstico , Biomarcadores de Tumor/sangre , Supervivencia sin Enfermedad , Femenino , Humanos , Estimación de Kaplan-Meier , L-Lactato Deshidrogenasa/sangre , Masculino , Persona de Mediana Edad , Análisis Multivariante , Micosis Fungoide/sangre , Micosis Fungoide/mortalidad , Micosis Fungoide/patología , Micosis Fungoide/terapia , Estadificación de Neoplasias , Modelos de Riesgos Proporcionales , Factores de Riesgo , Síndrome de Sézary/sangre , Síndrome de Sézary/mortalidad , Síndrome de Sézary/patología , Síndrome de Sézary/terapia , Neoplasias Cutáneas/sangre , Neoplasias Cutáneas/mortalidad , Neoplasias Cutáneas/patología , Neoplasias Cutáneas/terapia , Factores de TiempoRESUMEN
The marked photosensitivity associated with chronic actinic dermatitis (CAD) is presumed to be due to a T cell-mediated response to ultraviolet (UV)-induced epidermal neoantigens. Photosensitivity is, however, a rare occurrence in cutaneous T-cell lymphoma (CTCL). We discuss a series of four patients with erythrodermic CTCL who exhibited marked photosensitivity mimicking CAD. Significantly, the tumour cells had a CD8 phenotype in half of these patients. All patients had T-cell clones in skin and also demonstrated identical peripheral T-cell clones in blood or lymph node involvement. Sézary cell counts ranged from 6% to 20%, CD4/CD8 ratios from 0.22 to 23.5. Clinical presentation was striking for a marked photosensitive distribution. Monochromator irradiation testing revealed reduced minimal erythema doses throughout UVB and UVA ranges, findings consistent with those seen in CAD. All patients subsequently died from systemic disease. These findings suggest that, rarely, malignant clonal T-cell populations may recognize a unique UV-induced neoantigen, resulting in the clinical features of severe photosensitivity mimicking those seen in CAD.
Asunto(s)
Linfoma Cutáneo de Células T/diagnóstico , Trastornos por Fotosensibilidad/diagnóstico , Neoplasias Cutáneas/diagnóstico , Anciano , Dermatitis Exfoliativa/complicaciones , Dermatitis Exfoliativa/diagnóstico , Dermatitis Exfoliativa/patología , Diagnóstico Diferencial , Resultado Fatal , Humanos , Linfoma Cutáneo de Células T/complicaciones , Linfoma Cutáneo de Células T/patología , Masculino , Persona de Mediana Edad , Trastornos por Fotosensibilidad/etiología , Trastornos por Fotosensibilidad/patología , Neoplasias Cutáneas/complicaciones , Neoplasias Cutáneas/patología , Rayos Ultravioleta/efectos adversosRESUMEN
Folliculotropic mycosis fungoides is associated with a worse prognosis than classical mycosis fungoides (MF), but whether this is due to resistance to skin-directed therapy or to biological differences is unclear. We discuss a case of a patient with folliculotropic MF (stage IIA) who progressed to develop Sézary syndrome (SS), stage IVB, over 6 years. A 40-year-old man presented with pruritic plaques affecting his head and trunk, characterized by follicular plugging. The histology was consistent with folliculotropic MF and T-cell gene analysis studies revealed a T-cell clone in the skin only. His condition gradually deteriorated and 5 years after presentation, T-cell gene analysis studies revealed the presence of a clone in the blood identical with that seen in the skin. His condition progressed with the development of erythrodermic disease and a leukaemic blood picture and he subsequently died of systemic nodal and visceral involvement. We present the first report detailing the stepwise progression of a patient with stage IIA folliculotropic MF to SS. This case demonstrates that MF and SS represent a clinical spectrum of the same disease.
Asunto(s)
Mucinosis Folicular/patología , Micosis Fungoide/patología , Síndrome de Sézary/patología , Adulto , Recuento de Linfocito CD4 , Antígenos CD8 , Progresión de la Enfermedad , Resultado Fatal , Humanos , Masculino , Mucinosis Folicular/genética , Mucinosis Folicular/inmunología , Micosis Fungoide/genética , Micosis Fungoide/inmunología , Síndrome de Sézary/genética , Síndrome de Sézary/inmunologíaRESUMEN
Fatigue is frequent and disabling in patients with traumatic brain injury (TBI). Its mechanisms are complex and multifactorial. We performed a literature review of reports of the condition using the following key words: brain injury, depression, neuroendocrine dysfunction, and treatment. Five scales have been used to evaluate fatigue in TBI patients: the Fatigue Severity Scale, the visual analog scale (VAS) for fatigue, the Fatigue Impact Scale, the Barrow Neurological Institute (BNI) Fatigue Scale and the Cause of Fatigue (COF) Questionnaire. The BNI Fatigue Scale and the COF Questionnaire have been designed specifically for brain-injured patients. Fatigue is present in 43-73% of patients and is one of the first symptoms for 7% of them. Fatigue does not seem to be significantly related to injury severity not to time since injury. It can be related to mental effort necessary to overcome attention deficit and slowed processing ("coping hypothesis"). It can also be related to sleeping disorders and depression, although the relation between fatigue and depression are debated. Finally, fatigue can also be related to infraclinical pituitary insufficiency (growth hormone insufficiency, hypocorticism). To date, no published study of treatment of fatigue after TBI exists.
Asunto(s)
Lesiones Encefálicas/complicaciones , Fatiga/etiología , Lesiones Encefálicas/psicología , Depresión/complicaciones , Depresión/etiología , Fatiga/diagnóstico , Fatiga/psicología , Humanos , Hipopituitarismo/complicaciones , Hipopituitarismo/etiología , Trastornos del Sueño-Vigilia/complicaciones , Trastornos del Sueño-Vigilia/etiologíaRESUMEN
Invasion of brain tumor cells has made primary malignant brain neoplasms among the most recalcitrant to therapeutic strategies. We tested whether the secreted protein Slit2, which guides the projection of axons and developing neurons, could modulate brain tumor cell invasion. Slit2 inhibited the invasion of medulloblastoma cells in a variety of in vitro models. The effect of Slit2 was inhibited by the Robo ectodomain. Time-lapse videomicroscopy indicated that Slit2 reduced medulloblastoma invasion rate without affecting cell direction or proliferation. Both medulloblastoma and glioma tumors express Robo1 and Slit2, but only medulloblastoma invasion is inhibited by recombinant Slit2 protein. Downregulation of activated Cdc42 may contribute to this differential response. Our findings reinforce the concept that neurodevelopmental cues such as Slit2 may provide insights into brain tumor invasion.
Asunto(s)
Meduloblastoma/patología , Invasividad Neoplásica/prevención & control , Proteínas del Tejido Nervioso/fisiología , Animales , Astrocitoma/genética , Astrocitoma/patología , Neoplasias Encefálicas/patología , División Celular/efectos de los fármacos , Neoplasias Cerebelosas/genética , Neoplasias Cerebelosas/patología , Técnicas de Cocultivo , Medios de Cultivo Condicionados , Glioma/patología , Humanos , Péptidos y Proteínas de Señalización Intercelular , Cinética , Meduloblastoma/genética , Ratones , Microscopía por Video , Proteínas del Tejido Nervioso/genética , ARN Neoplásico/genética , ARN Neoplásico/aislamiento & purificación , Receptores Inmunológicos/genética , Receptores Inmunológicos/fisiología , Proteínas Recombinantes/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas , Proteínas RoundaboutRESUMEN
BACKGROUND: Skin is an inherently heterogeneous tissue, thus the procurement of pure cell populations is critical for the accurate correlation of a molecular profile to a particular cell type or histological location. Laser Capture Microdissection (LCM) permits the efficient procurement of cells and mapping of genetic changes from histologically prepared samples. METHODS: This paper describes a robust LCM protocol established in our laboratory for the extraction of high quality DNA which sequenced from 100% of microdissected samples without the need for cloning. The unique properties of skin, in particular its strong intercellular adhesive forces, have dictated a significant modification to the normal procedure of tissue preparation to ensure reliable cell procurement. RESULTS: Using the methods outlined below we were able to precisely map the pattern of genomic mutations in our target gene of interest in normal skin, actinic keratosis and squamous cell carcinoma. CONCLUSIONS: The capability to select pure cell populations from the skin will revolutionise our ability to understand the processes involved in cutaneous tumourigenesis.
Asunto(s)
Separación Celular/métodos , Técnicas Histológicas , Microdisección , Enfermedades de la Piel/patología , Biopsia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , ADN de Neoplasias/análisis , Humanos , Queratosis/genética , Queratosis/patología , Rayos Láser , Trastornos por Fotosensibilidad/genética , Trastornos por Fotosensibilidad/patología , Lesiones Precancerosas/genética , Lesiones Precancerosas/patología , Enfermedades de la Piel/genética , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/patologíaRESUMEN
This study was carried out to investigate sequel of oxidative insult to human erythrocytes induced by a water-soluble radical initiator, 2,2'-azobis-(amidinopropane) dihydrochloride (AAPH) and the effect of a commercially available mixed antioxidant (Blackmores, BioAce Excel), containing alpha-tocopherol, ascorbic acid, beta-carotene and some herbal extracts (containing grape seed catechins and milk thistle derived silybin), on lipid peroxidation, degradation of membrane proteins and haemolysis. We performed this study in order firstly to clarify aspects of the mechanism of AAPH induced free radical damage in human erythrocytes and secondly to establish in vitro conditions by which the efficacy of mixed antioxidant preparations may fairly and objectively be compared. In the process of oxidation initiated by peroxyl radical, a rapid loss of reduced glutathione occurred in the first 60 min. Formation of thiobarbitric acid-reactive substances indicative of lipid peroxidation increased subsequently and almost reached maximal levels at 180 min before significant apparent degradation of membrane proteins was detected. At this point, a significant haemolysis occurred. This sequence of events is consistent with the idea that haemolysis is a consequence of lipid peroxidation and the degradation of membrane proteins. The mixed commercial antioxidant, which suppressed lipid peroxidation and protected membrane proteins against degradation induced by peroxyl radicals, also effectively delayed AAPH induced haemolysis. The system we describe provides a sound objective basis for the in vitro comparison of the potential efficacy of the hundreds of antioxidant nutritional supplements currently available in the market place.
Asunto(s)
Amidinas/farmacología , Antioxidantes/farmacología , Eritrocitos/efectos de los fármacos , Hemólisis/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Oxidantes/farmacología , Amidinas/antagonistas & inhibidores , Ácido Ascórbico/farmacología , Catequina/farmacología , Combinación de Medicamentos , Eritrocitos/fisiología , Frutas , Glutatión/sangre , Humanos , Técnicas In Vitro , Cinética , Proteínas de la Membrana/sangre , Proteínas de la Membrana/efectos de los fármacos , Metahemoglobina/metabolismo , Extractos Vegetales/farmacología , Semillas , Silimarina/farmacología , Sustancias Reactivas al Ácido Tiobarbitúrico/análisis , Vitamina E/farmacología , beta Caroteno/farmacologíaRESUMEN
Three different types of red blood cells (RBC) were used: (i) RBC from sheep having genetically high GSH (ii) RBC from sheep with genetically low GSH and (iii) RBC from high-GSH sheep treated with CDNB to deplete GSH. Incubation of these RBC with t-butyl hydroperoxide (tBHP, 3 mM) for 10 min caused the formation of TBARS, oxidation of haemoglobin and degradation and aggregation of membrane proteins in RBC from low-GSH sheep and GSH-depleted RBC. By contrast, RBC from high-GSH sheep (normal RBC) did not show the degradation and aggregation of membrane proteins within the first 10 min. Dithiothreitol (DTT) was highly effective in preventing the tBHP-mediated oxidation of haemoglobin, the formation of TBARS and the degradation and aggregation of membrane proteins in both normal RBC and low-GSH RBC. However, DTT did not provide protection in GSH-depleted RBC or normal RBCs in the presence of 1.5 mM mercaptosuccinate (MCS), a potent inhibitor of GSH peroxidase (GSHPx). The ability of GSH to prevent the oxidation of haemoglobin and the degradation and aggregation of membrane proteins was abolished in the presence of MCS. These results indicate that the protective function of DTT involves a GSH-dependent mechanism. Both GSH and GSHPx play key roles in this enzymatic system. In the light of the complete protection of RBC against oxidation induced by tBHP in the presence of DTT or GSH, the GSH/GSHPx system appears to act directly as a tBHP scavenger. The activities of four well-known antioxidants, Butylated hydroxytoluene, ascorbate, alpha-tocopherol and desferrioxamine were also tested in this study to cast further light on the role of free radical scavenging in protection from tBHP mediated free radical insult.
Asunto(s)
Eritrocitos/efectos de los fármacos , Glutatión Peroxidasa/sangre , Glutatión/sangre , Estrés Oxidativo/efectos de los fármacos , terc-Butilhidroperóxido/farmacología , Animales , Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Hidroxitolueno Butilado/farmacología , Deferoxamina/farmacología , Ditiotreitol/farmacología , Eritrocitos/metabolismo , Ingeniería Genética , Glutatión Peroxidasa/efectos de los fármacos , Hemoglobinas/efectos de los fármacos , Hemoglobinas/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Proteínas de la Membrana/efectos de los fármacos , Proteínas de la Membrana/metabolismo , Ovinos/genética , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Vitamina E/farmacologíaRESUMEN
Severe diffuse traumatic brain injury (TBI) may impair the performance of daily-life complex activities. The aim of the present study was to assess whether these difficulties are related to a representational impairment of action knowledge. Two tasks requiring the manipulation of scripts were used. The first (script reconstitution) required subjects to sort cards describing actions belonging to 4 different scripts, presented in a random order. The second (script generation) required subjects to generate actions belonging to a given script. The results showed that TBI patients had preserved access to goal representation and action knowledge. However, they demonstrated (1) significant impairments when they had to deal with simultaneous competing sources of information and (2) a lack of inhibitory control on routine overlearned skills. Patients' performance was significantly correlated with behavioral modifications in everyday life. These data suggest that action impairment in severe TBI patients cannot be attributed to an impairment of action knowledge per se. As previously suggested by Schwartz et al., a restriction of limited-capacity processing resources may account for the observed deficits.
Asunto(s)
Actividades Cotidianas/psicología , Lesión Encefálica Crónica/diagnóstico , Traumatismos Cerrados de la Cabeza/diagnóstico , Recuerdo Mental , Adulto , Atención , Lesión Encefálica Crónica/psicología , Lesión Encefálica Crónica/rehabilitación , Formación de Concepto , Lesión Axonal Difusa/diagnóstico , Lesión Axonal Difusa/psicología , Lesión Axonal Difusa/rehabilitación , Femenino , Escala de Coma de Glasgow , Traumatismos Cerrados de la Cabeza/psicología , Traumatismos Cerrados de la Cabeza/rehabilitación , Humanos , Masculino , Pruebas Neuropsicológicas , Solución de Problemas , PronósticoRESUMEN
Haemolysis of red blood cells (RBC) in glycerol media may be measured spectrophotometrically. The haemolytic process in a rapid phase obeys a first order rate law. The rate constant expresses the rate of haemolysis. To gain a better understanding of the mechanism of haemolysis in glycerol media, the effects of pH and band 3 inhibitors on the rate of haemolysis in human and sheep RBC were observed. Over the pH range used (pH 5.8-10.0), the rate of haemolysis decreased with increase in pH in sheep RBC. By contrast, the rate of haemolysis increased from pH 5.8 to 6.4 and decreased above pH 6.4 in human RBC. The different effects of pH on the rate of haemolysis are due to inhibition of glycerol permeability by H(+) in human RBC but not in sheep RBC. This is supported by the different effects of temperature and Cu(2+) on the rate of haemolysis in human and sheep RBC. We did not observe complete inhibition of haemolysis by the classical band 3 inhibitor, 4, 4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS). Another band 3 inhibitor 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNDS) showed only weak inhibition. Phenylgloxal (PG), another band 3 inhibitor, had no effect whatsoever on the rate of haemolysis. These results indicate that the anion pathway of band 3 is not the preferred route of transport of glycerol in mammalian RBC.
Asunto(s)
Proteína 1 de Intercambio de Anión de Eritrocito/metabolismo , Eritrocitos/metabolismo , Glicerol/metabolismo , Hemólisis , Concentración de Iones de Hidrógeno , Ovinos/sangre , Animales , Proteína 1 de Intercambio de Anión de Eritrocito/antagonistas & inhibidores , Cobre/metabolismo , Medios de Cultivo , Humanos , Cinética , TemperaturaRESUMEN
Glutathione reductase (GR) activity and flavin concentration were studied in systemic tissues (brain, heart, lung, liver, spleen, stomach, pancreas, muscle, kidney, testis) and blood components (erythrocytes and plasma) from male guinea-pigs. GR activity and the flavin concentration were high in kidney and liver, and low in muscle. GR activity in erythrocytes was found in a range of tissues, but flavin concentration in erythrocytes was lower than in any tissues. GR was saturated with flavin adenine dinucleotide (FAD) in almost all tissues, but not in muscle or erythrocytes.
Asunto(s)
Flavinas/metabolismo , Glutatión Reductasa/metabolismo , Cobayas/metabolismo , Animales , Eritrocitos/metabolismo , Flavina-Adenina Dinucleótido/metabolismo , Masculino , Valores de Referencia , Distribución TisularRESUMEN
It was recently coincidentally discovered, using 1H NMR spectroscopy, that the erythrocytes of two species of Australian marsupials, Tammar Wallaby (Macropus eugenii) and Bettong (Bettongia penicillata), contain relatively high concentrations of the essential amino acid lysine (Agar NS, Rae CD, Chapman BE, Kuchel PW. Comp Biochem Physiol 1991;99B:575-97). Hence, in the present work the rates of transport of lysine into the erythrocytes from the Common Brushtail Possum (Dactylopsilia trivirgata) and Eastern Grey Kangaroo (Macropus giganteus) (which both have low lysine concentrations), and Tammar Wallaby were studied, to explore the mechanistic basis of this finding. The concentration-dependence of the uptake was studied with lysine alone and in the presence of arginine, which may be a competitor of the transport in some species. In relation to GSH metabolism, glutamate uptake was determined in the presence and absence of Na+. The data was analysed to yield estimates of the maximal velocity (Vmax) and the Km in each of the species. Erythrocytes from Tammar Wallaby lacked saturable lysine transport in contrast to the other two species. The glutamate uptake was normal in all three animals for adequate GSH biosynthesis.
Asunto(s)
Eritrocitos/metabolismo , Ácido Glutámico/sangre , Lisina/sangre , Macropodidae/sangre , Zarigüeyas/sangre , Aminoácidos/sangre , Animales , Transporte BiológicoRESUMEN
The phospholipid classes of erythrocyte membranes and plasma from several domestic animals and marsupials were quantified by 31P NMR using detergents. Washed erythrocyte samples were thoroughly haemolysed by tip-sonication and dissolved in sodium cholate; plasma samples were dissolved in Triton X-100. The species studied were: common wombat (Vombatus ursinus), black-striped wallaby (Macropus dorsalis), bandicoot (Isoodon macrocarpus), Eastern grey kangaroo (Macropus giganteus), Tammar wallaby (Macropus eugenii), sheep (Ovis aries), goat (Capra hircus), cattle (Bos taurus), horse (Equus caballus), dog (Canus familiaris) and rabbit (Orytolagus caniculus). There were considerable species variations in the relative abundance of erythrocyte and plasma phospholipid classes. The variations may be attributed to the habitats and diets of the animals as well as to their phylogenetic differences.