Overexpression of the immediate-early genes Egr1, Egr2, and Egr3 in two strains of rodents susceptible to audiogenic seizures.

Genetic animal models of epilepsy are an important tool for further understanding the basic cellular mechanisms underlying epileptogenesis and for developing novel antiepileptic drugs. We conducted a comparative study of gene expression in the inferior colliculus, a nucleus that triggers audiogenic seizures, using two animal models, the Wistar audiogenic rat (WAR) and the genetic audiogenic seizure hamster (GASH:Sal). For this purpose, both models were exposed to high intensity auditory stimulation, and 60min later, the inferior colliculi were collected. As controls, intact Wistar rats and Syrian hamsters were subjected to stimulation and tissue preparation protocols identical to those performed on the experimental animals. Ribonucleic acid was isolated, and microarray analysis comparing the stimulated Wistar and WAR rats showed that the genomic profile of these animals displayed significant (fold change, |FC|≥2.0 and p<0.05) upregulation of 38 genes and downregulation of 47 genes. Comparison of gene expression profiles between stimulated control hamsters and stimulated GASH:Sal revealed the upregulation of 10 genes and the downregulation of 5 genes. Among the common genes that were altered in both models, we identified the zinc finger immediate-early growth response gene Egr3. The Egr3 protein is a transcription factor that is induced by distinct stress-elicited factors. Based on immunohistochemistry, this protein was expressed in the cochlear nucleus complex, the inferior colliculus, and the hippocampus of both animal models as well as in lymphoma tumors of the GASH:Sal. Our results support that the overexpression of the Egr3 gene in both models might contribute to neuronal viability and development of lymphoma in response to stress associated with audiogenic seizures. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".

T-cell intracellular antigens function as tumor suppressor genes.

Knockdown of T-cell intracellular antigens TIA1 and TIAR in transformed cells triggers cell proliferation and tumor growth. Using a tetracycline-inducible system, we report here that an increased expression of TIA1 or TIAR in 293 cells results in reduced rates of cell proliferation. Ectopic expression of these proteins abolish endogenous TIA1 and TIAR levels via the regulation of splicing of their pre-mRNAs, and partially represses global translation in a phospho-eukaryotic initiation factor 2 alpha-dependent manner. This is accompanied by cell cycle arrest at G1/S and cell death through caspase-dependent apoptosis and autophagy. Genome-wide profiling illustrates a selective upregulation of p53 signaling pathway-related genes. Nude mice injected with doxycycline-inducible cells expressing TIA1 or TIAR retard, or even inhibit, growth of xenotumors. Remarkably, low expressions of TIA1 and TIAR correlate with poor prognosis in patients with lung squamous cell carcinoma. These findings strongly support the concept that TIA proteins act as tumor suppressor genes.

Carcinoma basaloide de pulmón: aspecto citológico y problemas diagnósticos en cepillado bronquial / Basaloid lung carcinoma: Cytological appearance and diagnostic problems with bronchial brush

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Altered expression of immunoreactive involucrin in lamellar ichthyosis.

In some cases of lamellar ichthyosis, mutations in the epidermal transglutaminase gene and a reduction in the thickness of the cornified envelope have been documented. Involucrin is a major component of the cornified envelope and a substrate for epidermal transglutaminase. The aim of the present work was to analyse the expression of involucrin in lamellar ichthyosis. An ultrastructural study and/or immunohistochemical and biochemical techniques with anti-involucrin antibody were carried out on the epidermis of fifteen patients (12 families) suffering from lamellar ichthyosis. The effect of in vivo retinoid treatment on the involucrin epidermal expression was also investigated. Four cases with normal skin, seventeen cases of other ichthyoses and ten cases of psoriasis were used as controls. In all these cases of lamellar ichthyosis, a thin or absent cornified envelope, electron-dense granules inside corneocytes and a decrease of the epidermal involucrin expression were observed. In the patients receiving treatment with retinoids, western blot and ELISA revealed an increase in the involucrin expression. The decreased expression of involucrin in lamellar ichthyosis could contribute to the altered desquamation process accompanying the disease, since the clinical improvement associated with retinoid treatment is accompanied by an increase in the expression of involucrin.

Protective effect of exogenous nitric oxide on the renal function and inflammatory response in a model of ischemia-reperfusion.

BACKGROUND: Tissue subjected to a period of ischemia undergoes morphological and functional damage that increases during the reperfusion phase. The aim of the present work was to assess the possible improvement induced by exogenous administration of nitric oxide (NO) on renal injury and inflammatory reaction in an experimental animal model of renal ischemia-reperfusion (I-R). METHODS: Ischemia was achieved by ligation of the left arteria and vein for 60 min, followed first by contralateral nephrectomy and then reestablishment of blood flow. Molsidomine, used as an NO donor, was administered by systemic injection 30 min before reperfusion. The effect of molsidomine was compared with the effect of hydralazine, a non-NO donor hypotensive agent. RESULTS: Treatment with molsidomine improved the renal dysfunction (increase in plasma creatinine and urea levels) caused by I-R. Moreover, molsidomine blunted the enhanced production of proinflammatory cytokines (tumor necrosis factor [TNF]-alpha and interleukin [IL] 1alpha), the increase in tissular levels of superoxide anions and oxygen free radical scavengers, and the neutrophilic infiltration observed in the ischemic kidney. One hundred percent survival was achieved in the group of animals treated with the NO donor, whereas the groups of animals undergoing I-R that did not receive molsidomine showed a 40% mortality from the second day after reperfusion. CONCLUSIONS: The present work demonstrated that systemic treatment with an NO donor before reperfusion improved renal function and diminished inflammatory responses in a kidney subjected to an I-R process.

[Perfusion of donor tissue improves the preservation of graft in heterotopic tracheal transplantation]. / La perfusión tisular del donante mejora la conservación del injerto en el transplante traqueal heterotópico.

To assess the effect on tracheal graft preservation of perfusion of donor tissue with a Collins solution before extraction and immunosuppression of the recipient. An experimental study was performed in 36 albino rabbits with revascularized heterotopic cervical reconstruction of the trachea with omentum. The animals were distributed in four groups. Groups I (n = 9) and III (n = 9) were transplanted with non perfused donor tissue. Animals in groups II (n = 9) and IV (n = 9) received grafts perfused with Collins solution. Immunosuppression with steroids and cyclosporin was continued for 21 days in groups III and IV. In a mid portion of the trachea viewed under optical microscope, the degree of inflammation or circumferential necrosis was assessed on a scale of 0 to 9 by adding the scores for mucosa, submucosa and cartilage. The mean score for tracheal lesion was lower in group IV, with a likelihood of random difference of less than 5%. Perfusion of peritracheal tissues with Collins solution in the donor, in addition to immunosuppression decreases the extent of tissue damage in the tracheal graft.

Enzymatic determination of phosphatidylcholine, sphingomyelin and phosphatidylglycerol in lipid dispersions, blood cell membranes and rat pulmonary surfactant.

A new micromethod for the determination of sphingomyelin in samples suspended in aqueous solutions, and modified micromethods for determining phosphatidylcholine and phosphatidylglycerol were used to determine phosphatidylcholine and sphingomyelin (detection limits of 1.8 mumol/l), and phosphatidylglycerol (detection limit of 2.3 mumol/l) in lipid dispersions, membranes from sheep erythrocytes and platelets, and pulmonary surfactants from rats of different ages and rats maintained under normobaric hyperoxia for 2 days prior to their sacrifice. The procedures are easy to perform, accurate, require less sample than conventional methods and can also be applied directly to aqueous samples. Phospholipase C and sphingomyelinase were used to release phosphorylcholine from phosphatidylglycerol and sphingomyelin, respectively. The choline released from phosphorylcholine by alkaline phosphatase is reconverted to phosphorylcholine by ATP and choline kinase. In the phophatidylglycerol determination, phospholipase D was used to release glycerol and phosphatidate. The glycerol formed was converted to glycerolphosphate using ATP and glycerol kinase. In all cases, the ADP thus formed was determined by following the enzymatic conversion of NADH to NAD at 340 nm in an coupled pyruvate kinase/lactate dehydrogenase system. Significant variations in the phospholipid composition of rat pulmonary surfactant were found during development; in particular there was an increase in the phosphatidylglycerol content of adult rats as compared with younger rats. Hyperoxia produced changes in the phosphatidylglycerol content of surfactant from adult rats, but not from 2-day old rats.

Benign cephalic histiocytosis: case report and literature review.

A 3-year-old boy had maculopapules on his face and neck since age 6 months. These were yellow-brown, asymptomatic, and clinically similar to flat warts. Histopathologic study revealed a fibrohistiocytic infiltrate in the superficial dermis. Ultrastructurally, comma-shaped bodies, desmosome-like junctions, and coated vesicles were seen; there were no lipid droplets or Birbeck granules. With these data, a diagnosis of benign cephalic histiocytosis was made. Twenty-five cases are reported in the literature: 17 males and 8 females (male:female ratio 2:1). Sixteen patients had lesions on parts of the body other than the head, neck, and shoulders.

Local pathological findings in experimental dorsal root entry zone lesions performed by mechanical section, laser and radiofrequency. A comparative study.

Dorsal root entry zone lesions are nowadays accepted as a first choice of treatment to alleviate certain types of chronic pain though it is still controversial to decide proper procedure for lesioning. Based on this last argument in 15 mongrel dogs different types of lesions using mechanical microsection, radiofrequency and laser were done. Under general anaesthesia a C-3 to C-7 laminectomy was performed in all animals and after open the dura mater the posterior nerve rootlets and posterolateral sulcus were identified using magnification. In 5 dogs, a longitudinal 1 mm deep incision from C-4 to C-6 spinal cord segments coinciding with the sulcus was carried out with a microknife; in other 5, a sequence of thermocoagulations produced by a radiofrequency current lower than 35 mA was done at same places and level with intervals of 2 mm; and in the rest of animals, an alike incision in depth, location and level was realised by carbon dioxide laser. Four days and three months after lesioning 2 and 3 animals of each group were sacrificed and spinal cord specimens submitted for histological and ultrastructural studies. Low-power microscopic examination showed that all lesioning methods were able to produce a reasonable well delimited necrotic area involving the whole dorsal root entry zone structures, slightly more diffuse with the laser. Acute perilesional changes as well as chronic ones were nevertheless more evident in mechanical and radiofrequency lesions, over all regarding oedema, perivascular haemorrhage, intraluminal thrombosis and ischaemic alterations.

Distribution of primary cochlear afferents in the bulbar nuclei of the rat: a horseradish peroxidase (HRP) study in parasagittal sections.

HRP was injected into the cochleae of 25 young albino rats in order to trace the primary afferents to the bulbar cochlear nuclei. Besides the classic V-shaped pattern and unconnected with it, HRP labelling revealed two plexuses stemming directly from the axons of the cochlear root. The plexuses cover the posterior area of the posteroventral cochlear nucleus (posterior plexus) and the anterolaterodorsal area of the anteroventral cochlear nucleus (anterior plexus). The fibres giving rise to these two plexuses were previously grouped in two bundles which have been called the posterior and anterior bundles, respectively. The origin of the anterior bundle is typically seen with the fibres stemming out at right angles; the origin and course of the posterior bundle, which characteristically cross over, is also a typical feature.

Plexiform structures in malignant schwannomas after prenatal exposure to ethylnitrosourea.

75 Schwann cell tumors were induced in the offspring of Wistar rats which had been treated intraperitoneally with 15 mg/kg b.w. ethylnitrosourea on the 15th day of pregnancy. Plexiform structures characterized by poorly-developed, distorted and bizarre bundles of nerves were seen in 2 of 33 benign tumors, and in 17 of 42 malignant schwannomas. Since when seen in man similar findings are distinctive of neurofibromatosis, it is suggested that this experiment may offer a model for studying non-inherited forms of neurofibromatosis and, more particularly, the malignant changes often associated with this disease.

Morphology of Hensen's cells.

The cochleae of ten guinea-pigs were studied by transmission electron microscopy, scanning electron microscopy and optical microscopy, using specific techniques for staining fats. The study of Hensen's cells showed the existence of prominent lipid droplets in the apex and the third coil of the cochlea. Similar images were not found in the basal coil. Lipids appear to be expelled into the endolymphatic space. The significance of these findings is discussed with respect to the geometry of the lateral anchorage of the tectorial membrane and to the possibility that Hensen's cells represent a modulation mechanism in the transmission of mechanical energy.