Auditory steady state response in hearing assessment in infants with cytomegalovirus

OBJETIVO:Relatar o caso de um lactente com citomegalovírus congênito e disacusia neurossensorial progressiva, analisado por três métodos de avaliação auditiva.DESCRIÇÃO DO CASO:Na primeira avaliação auditiva, aos quatro meses de idade, o lactente apresentou ausência de Emissões Otoacústicas (EOA) e Potencial Evocado Auditivo de Tronco Encefálico (PEATE) dentro dos padrões de normalidade para a faixa etária, com limiar eletrofisiológico em 30dBnHL, bilateralmente. Com seis meses, apresentou ausência de PEATE bilateral em 100dBnHL. A avaliação comportamental da audição mostrou-se prejudicada devido ao atraso no desenvolvimento neuropsicomotor. Aos oito meses, foi submetido ao exame de Resposta Auditiva de Estado Estável (RAEE) e os limiares encontrados foram 50, 70, ausente em 110 e em 100dB, respectivamente para 500, 1.000, 2.000 e 4.000Hz, à direita, e 70, 90, 90 e ausente em 100dB, respectivamente para 500, 1.000, 2.000 e 4.000Hz, à esquerda.COMENTÁRIOS:Na primeira avaliação, o lactente apresentou alteração auditiva no exame de EOA e PEATE normal, que passou a ser alterado aos seis meses de idade. A intensidade da perda auditiva só pôde ser identificada pelo exame de RAEE, permitindo estabelecer a melhor conduta na adaptação de aparelho de amplificação sonora individual. Ressalta-se a importância do acompanhamento audiológico para crianças com CMV congênito.

Differential Evolutionary Constraints in the Evolution of Chemoreceptors: A Murine and Human Case Study

Chemoreception is among the most important sensory modalities in animals. Organisms use the ability to perceive chemical compounds in all major ecological activities. Recent studies have allowed the characterization of chemoreceptor gene families. These genes present strikingly high variability in copy numbers and pseudogenization degrees among different species, but the mechanisms underlying their evolution are not fully understood. We have analyzed the functional networks of these genes, their orthologs distribution, and performed phylogenetic analyses in order to investigate their evolutionary dynamics. We have modeled the chemosensory networks and compared the evolutionary constraints of their genes in Mus musculus, Homo sapiens, and Rattus norvegicus. We have observed significant differences regarding the constraints on the orthologous groups and network topologies of chemoreceptors and signal transduction machinery. Our findings suggest that chemosensory receptor genes are less constrained than their signal transducing machinery, resulting in greater receptor diversity and conservation of information processing pathways. More importantly, we have observed significant differences among the receptors themselves, suggesting that olfactory and bitter taste receptors are more conserved than vomeronasal receptors.

Hypusine Modification of the Ribosome-binding Protein eIF5A, a Target for New Anti-Inflammatory Drugs: Understanding the Action of the Inhibitor GC7 on a Murine Macrophage Cell Line

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Citral and eugenol modulate DNA damage and pro-inflammatory mediator genes in murine peritoneal macrophages

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of cell cycle synchronization on the accuracy of murine and bovine embryo sex determination

Different cell cycle synchronization methods were used to increase the mitotic index and accuracy of sex determination in murine and bovine embryos. For sexing purposes, colchicine treatment for 2, 4, 6 and 8 h and the FdU-thymidine-colchicine combination were tested in murine embryos. The best results were obtained with colchicine treatment for 8 h (96.88% accuracy) and with FdU-thymidine-colchicine (97.22% accuracy). Mitotic indexes differed significantly between the 2 treatments (21.71% for colchicine and 32.95% for FdU-thymidine-colchicine). For sex identification of murine and bovine demi-embryos, both treatments were demonstrated to be equally effective (nearly 90%). The mitotic index for the FdU-treated murine demi-embryos (19.04%) was higher than the one obtained for the 8-h colchicine treatment (15.62%).

Nutritional status and immune response in murine experimental Jorge Lobo's disease

There are no studies investigating the role of nutritional status and immunity associated with Jorge Lobo's disease. The objective of this study was to evaluate the effects of protein-calorie malnutrition on the immune response of BALB/c mice inoculated with Lacazia loboi. In this study,the animals were divided into four groups: G1: inoculated with restricted diet, G2: not inoculated with restricted diet, G3: inoculated with regular diet, G4: not inoculated with regular diet. The animals of groups G1 and G2 were submitted to malnutrition for 20 days and once installed the animals were inoculated intradermally into the footpad. After 4 months, they were euthanised for the isolation of peritoneal lavage cells and removal of the footpad. The production of IL-2, IL-4, IL-10, IL-12, IFN-γ, TNF-α, H2 O2 and nitric oxide (NO) was evaluated in the peritoneal lavage cells. The footpad was evaluated regarding the size of macroscopic lesions, number of fungi and viability index. The results showed that the infection did not exert great influence on the body weight of the mice and previous malnutrition was an unfavourable factor for viability index, number of fungi, macroscopic lesion size in the footpad and production of H2 O2 , NO, IL-12, IL-10 and IFN-γ, suggesting that malnutrition significantly altered fungal activity and peritoneal cells. The results suggest considerable interaction between nutrition and immunity in Jorge Lobo's disease.

Effects of probiotic Lactobacillus gasseri strains of breast-fed infant in a murine model

The ingestion of probiotic lactic acid bacteria has been evaluated and noted that it has an effect on the balance of desirable microbiota in the gastrointestinal tract. Lactobacillus gasseri demonstrates good survival in the gastrointestinal tract, and it has been associated with a variety of probiotic activities and roles, including the reduction of fecal mutagenic enzymes, the production of bacteriocins and the stimulation of macrophages immunomodulation. The aim of the study was to evaluate the effects of a pool of L. gasseri strains isolated from the feces of breastfed infants added in the human milk of healthy women. The milk was both pasteurized and unpasteurized, to verify the cell cytotoxicity of macrophages and to quantify the production of immunologic mediators such as IL-4, IL-6, IFN-g, TNF-a, NO and oxygen intermediary compounds (H2O2). The administration of raw human milk and pasteurized human milk to infants is a regular, encouraged practice in units of intensive therapy (UITs) and our present investigation verified the beneficial effect of addition of a pool of L. gasseri to pasteurized human milk (PHML). Our results show that probiotic supplementation helped to maintain cell viability, reduced IL-6 and IFN-γ production and stimulated TNF-α, NO, H2O2, IL-4 production. Nevertheless, the results indicate that the addition of lactobacillus to human milk was not a determinant in the production of TNF-α. L. gasseri added to breast milk did not present a cytotoxic risk, and the addition of L. gasseri to pasteurized milk of human milk bank would benefit newborns that depend on milk banks for the colonization of more desirable microbiota.

Severe distal cytomegalovirus esophagitis with aerodigestive symptoms in an immunocompetent infant

We report a case of an immunocompetent infant, with no evidence of neurological disorders, which developed clinical manifestation of recurrent crisis of choking, dysphagia, laryngeal stridor and sub costal retractions since the first day of life. Direct laryngoscopy was unremarkable. Upper gastrointestinal series showed a dilated tortuous esophagus with severe peristalsis impairment and reflux episodes till the proximal third of the esophagus. An upper gastrointestinal endoscopy showed a moderately dilated esophagus with erosive lesions in the distal esophagus. Esophageal biopsy specimens revealed CMV inclusion bodies associated to moderate inflammation and immunohistochemistry was positive for CMV early antigen. Prolonged 24 h esophageal pH metry was within normal limits. Antiviral therapy with intravenous ganciclovir was introduced and was associated with rapid improvement of the symptoms. Child gradually increased oral intake and weight gain, and there were no side effects related to therapy. Thus, the respiratory symptoms could have been a supra esophageal manifestation of a non-acid reflux disease related to the CMV esophagitis.

Pharmacokinetics of Photogem Using Fluorescence Spectroscopy in Dimethylhydrazine-Induced Murine Colorectal Carcinoma

This study aimed to investigate the pharmacokinetics of a hematoporphyrin derivative in colonic tumors induced by dimethylhydrazine and adjacent normal colon in Wistar rats using an in vivo fluorescence spectroscopy technique. In conventional clinical application of photodynamic therapy, the interval between photosensitizer (PS) administration and lesion illumination is often standardized without taking into account variations due to the type or localization of the tumor and intrinsic differences in the microcirculation and vascular permeability of each target organ. The analysis of the fluorescence spectra was based on the intensity of porphyrin emission band centered at around 620nm in normal colon and colon tumors. The photosensitizer fluorescence intensity rapidly grew for carcinoma and normal colon, reaching the maximum values 1 and 3 hours after PS injection, respectively. Data presented here allow us to verify that the best compromise between selectivity and drug concentration for colon carcinoma in rats took place in the interval between 1 to 4 h after PS injection.

NLRP3 inflammasome-mediated neutrophil recruitment and hypernociception depend on leukotriene B4 in a murine model of gout

Objective Deposition of monosodium urate monohydrate (MSU) crystals in the joints promotes an intense inflammatory response and joint dysfunction. This study evaluated the role of the NLRP3 inflammasome and 5-lipoxygenase (5-LOX)derived leukotriene B4 (LTB4) in driving tissue inflammation and hypernociception in a murine model of gout. Methods. Gout was induced by injecting MSU crystals into the joints of mice. Wild-type mice and mice deficient in NLRP3, ASC, caspase 1, interleukin-1 beta (IL-1 beta), IL-1 receptor type I (IL-1RI), IL-18R, myeloid differentiation factor 88 (MyD88), or 5-LOX were used. Evaluations were performed to assess neutrophil influx, LTB4 activity, cytokine (IL-1 beta, CXCL1) production (by enzyme-linked immunosorbent assay), synovial microvasculature cell adhesion (by intravital microscopy), and hypernociception. Cleaved caspase 1 and production of reactive oxygen species (ROS) were analyzed in macrophages by Western blotting and fluorometric assay, respectively. Results. Injection of MSU crystals into the knee joints of mice induced neutrophil influx and neutrophildependent hypernociception. MSU crystal-induced neutrophil influx was CXCR2-dependent and relied on the induction of CXCL1 in an NLRP3/ASC/caspase 1/IL-1 beta/MyD88-dependent manner. LTB4 was produced rapidly after injection of MSU crystals, and this was necessary for caspase 1-dependent IL-1 beta production and consequent release of CXCR2-acting chemokines in vivo. In vitro, macrophages produced LTB4 after MSU crystal injection, and LTB4 was relevant in the MSU crystalinduced maturation of IL-1 beta. Mechanistically, LTB4 drove MSU crystal-induced production of ROS and ROS-dependent activation of the NLRP3 inflammasome. Conclusion. These results reveal the role of the NLRP3 inflammasome in mediating MSU crystalinduced inflammation and dysfunction of the joints, and highlight a previously unrecognized role of LTB4 in driving NLRP3 inflammasome activation in response to MSU crystals, both in vitro and in vivo.

CD25(+) T cell depletion impairs murine squamous cell carcinoma development via modulation of antitumor immune responses

Squamous cell carcinoma (SCC) constitutes a microenvironment that could modulate the antitumor immune response. Also, tumor-infiltrating lymphocytes are believed to play complex regulatory roles in antitumor immunity against SCC. The presence of regulatory T cells (Tregs) has been associated with the suppression of tumor-reactive T cells. However, the underlying mechanism for this T cell dysfunction is not clear. We used a multistage model of SCC to examine the role of Treg cells during tumor development. 7,12-dimethylbenz[a]-anthracene/phorbol 12-myristate 13-acetate treatment and systemic depletion of Treg cells using an anti-CD25 monoclonal antibody (PC61) resulted in a decrease in the number and incidence of papilloma. Furthermore, CD25 depletion increased the proportion of CD8(+) and CD4(+) T cells that were isolated from tumor lesions. The levels of interleukin (IL)-1 beta, IL-10, IL-12, IL-13, interferon-gamma, transforming growth factor-beta and tumor necrosis factor-alpha, but not IL-17, were increased in the tumor microenvironment after Treg depletion. Therefore, our results indicated involvement of CD25(+) T cells in SCC development and in the suppression of the inflammatory immune response.

The contribution of a murine CNS-TB model for the understanding of the host-pathogen interactions in the formation of granulomas

Central nervous system (CNS) tuberculosis (TB) is the most severe form of TB, characterized morphologically by brain granulomas and tuberculous meningitis (TBM). Experimental strategies for the study of the host-pathogen interaction through the analysis of granulomas and its intrinsic molecular mechanisms could provide new insights into the neuropathology of TB. To verify whether cerebellar mycobacterial infection induces the main features of the disease in human CNS and better understand the physiological mechanisms underlying the disease, we injected bacillus Calmette-Guerin (BCG) into the mouse cerebellum. BCG-induced CNS-TB is characterized by the formation of granulomas and TBM, a build up of bacterial loads in these lesions, and microglial recruitment into the lesion sites. In addition, there is an enhanced expression of signaling molecules such as nuclear factor-kappa B (NF-kappa B) and there is a presence of inducible nitric oxide synthase (iNOS) in the lesions and surrounding areas. This murine model of cerebellar CNS-TB was characterized by cellular and biochemical immune responses typically found in the human disease. This model could expand our knowledge about granulomas in TB infection of the cerebellum, and help characterize the physiological mechanisms involved with the progression of this serious illness that is responsible for killing millions people every year. (C) 2012 Elsevier B.V. All rights reserved.

Leishmania (V.) braziliensis and L. (L.) amazonensis promote differential expression of dendritic cells and cellular immune response in murine model

The expression of Langerhans cell (LC) and dermal dendritic cell (dDC) as well as T CD4+ and CD8+ immune responses was evaluated in the skin of BALB/c mice experimentally infected by L. (L.) amazonensis (La) and L. (V.) braziliensis (Lb). At 4th and 8th weeks post infection (PI), skin biopsies were collected to determine the parasite load and CD207+, CD11c+, CD4+, CD8+, iNOS+ cellular densities. Cytokine (IFN-?, IL-4 and IL-10) profiles were also analysed in draining lymph node. At 4th week, the densities of CD207+ and CD11c+ were higher in the La infection, while in the Lb infection, these markers revealed a significant increase at 8th week. At 4th week, CD4+ and CD8+ were higher in the La infection, but at 8th week, there was a substantial increase in both markers in the Lb infection. iNOS+ was higher in the Lb infection at 4th and 8th weeks. In contrast, the parasite load was higher in the La infection at 4th and 8th weeks. The concentration of IFN-? was higher in the Lb infection, but IL-4 and IL-10 were higher in the La infection at 4th and 8th weeks. These results confirm the role of the Leishmania species in the BALB/c mice disease characterized by differences in the expression of dendritic cells and cellular immune response.