Multifunctional roles for MALT1 in T-cell activation

The activation of T cells is vital to the successful elimination of pathogens, but can also have a deleterious role in autoimmunity and transplant rejection. Various signalling pathways are triggered by the T-cell receptor; these have key roles in the control of the T-cell response and represent interesting targets for therapeutic immunomodulation. Recent findings define MALT1 (mucosa-associated-lymphoid-tissue lymphoma-translocation gene 1) as a protein with proteolytic activity that controls T-cell activation by regulating key molecules in T-cell-receptor-induced signalling pathways

Citrobacter rodentium Requires Intestinal Neural Wiskott-Aldrich Syndrome Protein (N-WASp) for Actin Pedestal Formation, Colonization and Epithelial Barrier Disruption In Vivo

Background: Citrobacter rodentium is a natural mouse pathogen that is genetically closelyrelated to the human enteric pathogens enteropathogenic and enterohemorrhagic E. coli.Among the repertoire of conserved virulence factors that these pathogens deliver via typeIII secretion, Tir and EspF are responsible for the formation of characteristic actin-richpedestals and disruption of tight junction integrity, respectively. There is evidence In Vitrothese effectors accomplish this, at least in part, by subverting the normal host cellularfunctions of N-WASP, a critical regulator of branched chain actin assembly. Although NWASPhas been shown to be involved in pedestal formation In Vitro, the requirements ofN-WASP-mediated actin pedestals for intestinal colonization by attaching/effacing (A/E)pathogens In Vivo is not known. Furthermore, it is not known whether N-WASP is requiredfor EspF-mediated tight junction disruption. Methods: To investigate the role of N-WASPin the gut epithelium, we generated mice with intestine-specific deletion of N-WASP(iNWKO), by mating mice homozygous for a floxed N-WASP allele (N-WASPL2L/L2L) tomice expressing Cre recombinase under the villin promoter. Separately housed groups ofWT and iNWKO mice were inoculated with 5x108 GFP-expressing C. rodentium by intragastriclavage. Stool was collected 2, 4, 7, and 12 days after infection, and recoverablecolony forming units (CFUs) of C. rodentium were quantified by plating serial dilutions ofhomogenized stool on MacConkey's agar. GFP+ colonies were counted after 24 hoursincubation at 37°C. The presence of actin pedestals was investigated by electron microscopy(EM), and tight junction morphology was assessed by immunofluorescence staining ofoccludin, ZO-1 and claudin-2. Results: C. rodentium infection did not result in mortalityin WT or iNWKO mice. Compared to controls, iNWKO mice exhibited higher levels ofbacterial shedding during the first 4 days of infection (day 4 average: WT 5.2x104 CFU/gvs. iNWKO 4.7x105 CFU/g, p=0.08), followed by a more rapid clearance of C. rodentium, (day7-12 average: WT 2x106 CFU/g vs. iNWKO 2.7x105, p=0.01). EM and immunofluorescencerevealed the complete lack of actin pedestals in iNWKO mice and no mucosa-associatedGFP+ C. rodentium by day 7. WT controls exhibited tight junction disruption, reflected byaltered distribution of ZO-1, whereas iNWKO mice had no change in the pattern of ZO-1.Conclusion: Intestinal N-WASP is required for actin pedestal formation by C. rodentium InVivo, and ablation of N-WASP is associated with more rapid bacterial clearance and decreasedability of C. rodentium to disrupt intercellular junctions.

The temporoparietal fascia flap: a versatile tool in head and neck reconstruction.

PURPOSE OF REVIEW: The article reviews recent significant advances and current applications of the temporoparietal fascia flap (TPFF) in head and neck surgery. RECENT FINDINGS: The recent literature describes a wide span of new applications of the TPFF in many areas. Significant developments and refinements in the reconstruction of orbitomaxillary composite defects and orbital exenteration cavities are reported. The TPFF combined with alloplastic framework is gaining in importance in external ear reconstruction. Innovative prefabricated skin or soft-tissue grafts based on the TPFF are used to restore facial contour or in the reconstruction of complex facial defects. The free TPFF finds a role in laryngotracheal reconstruction as a vascular carrier to support cartilage grafts. SUMMARY: Owing to its reliability and unequalled structural properties, the TPFF still plays a central role in facial reconstruction. Future investigation will likely incorporate the free TPFF as a vascular carrier of bioengineered tissues, such as cartilage and mucosa, for various head and neck indications.

The immunological, environmental, and phylogenetic perpetrators of metastatic leishmaniasis.

Cutaneous leishmaniases have persisted for centuries as chronically disfiguring parasitic infections affecting millions of people across the subtropics. Symptoms range from the more prevalent single, self-healing cutaneous lesion to a persistent, metastatic disease, where ulcerations and granulomatous nodules can affect multiple secondary sites of the skin and delicate facial mucosa, even sometimes diffusing throughout the cutaneous system as a papular rash. The basis for such diverse pathologies is multifactorial, ranging from parasite phylogeny to host immunocompetence and various environmental factors. Although complex, these pathologies often prey on weaknesses in the innate immune system and its pattern recognition receptors. This review explores the observed and potential associations among the multifactorial perpetrators of infectious metastasis and components of the innate immune system.

Alho em pó na alimentação alternativa de frangos de corte

O objetivo deste trabalho foi estudar o efeito da inclusão de alho em pó (Allium sativum) em rações para frangos, sobre desempenho, rendimento de carcaça e partes, peso de órgãos, níveis de colesterol e triacilgliceróis sangüíneos, e morfometria intestinal. Foram utilizados 720 pintainhos machos Cobb, com um dia de idade, distribuídos em blocos casualizados com seis tratamentos: ração sem promotor de crescimento (PC), sem anticoccidiano (AC) e com 0,00, 0,25, 0,50, 0,75 e 1,00% de alho; e ração com PC+AC, com quatro repetições de 30 aves cada. Peso, ganho de peso, consumo de ração, conversão alimentar e mortalidade foram obtidos aos 21 e 42 dias de idade. Aos 42 dias de idade foram abatidas 20 aves por tratamento para determinação do rendimento de carcaça e 4 aves para avaliação do peso de órgãos e morfometria intestinal. Sangue de 8 aves por tratamento foi colhido para determinação de colesterol e triacilgliceróis. Em aves alimentadas até 42 dias de idade com ração sem promotor de crescimento e anticoccidiano, a inclusão de até 1,00% de alho em pó beneficiou a conversão alimentar e não alterou o rendimento de carcaça e partes, peso relativo dos órgãos, mucosa intestinal, nem os níveis séricos de colesterol e triacilgliceróis. O alho não substitui com eficiência o antibiótico usado como promotor de crescimento em rações de frangos.

Immune responses to Helicobacter pylori infection.

Helicobacter pylori (H. pylori) infection is one of the most common infections in human beings worldwide. H. pylori express lipopolysaccharides and flagellin that do not activate efficiently Toll-like receptors and express dedicated effectors, such as γ-glutamyl transpeptidase, vacuolating cytotoxin (vacA), arginase, that actively induce tolerogenic signals. In this perspective, H. pylori can be considered as a commensal bacteria belonging to the stomach microbiota. However, when present in the stomach, H. pylori reduce the overall diversity of the gastric microbiota and promote gastric inflammation by inducing Nod1-dependent pro-inflammatory program and by activating neutrophils through the production of a neutrophil activating protein. The maintenance of a chronic inflammation in the gastric mucosa and the direct action of virulence factors (vacA and cytotoxin-associated gene A) confer pro-carcinogenic activities to H. pylori. Hence, H. pylori cannot be considered as symbiotic bacteria but rather as part of the pathobiont. The development of a H. pylori vaccine will bring health benefits for individuals infected with antibiotic resistant H. pylori strains and population of underdeveloped countries.

Immunohistochemical analysis of bone morphological protein signaling pathway in human myometrium.

We assessed by immunohistochemistry the expression of the phosphorylated (activated) form of Smad1 and 5 (P-SMAD1/5), of Noggin and of two smooth muscle cell markers (α-SMA and SM22) in a series of human myometrium samples and in a smooth muscle cell line derived from human myometrium (HUt-SMC, PromoCell, USA). Myometrium samples were removed from two cadavers (a fetus at 26weeks of gestation and a neonate) and from ten non-menopausal women who underwent hysterectomy for adenomyosis and leiomyoma. P-SMAD1/5 expression was never detected in myometrium (both normal and pathological specimens), but only as a nuclear positive staining in glandular and luminal epithelial cells in sections in which also the endometrial mucosa was present. Noggin was strongly expressed especially in myometrium and adenomyosis samples from non-menopausal patients in comparison to the neonatal and fetal myometrium specimens in which muscle cells were less positive. In more than 95% of HUt-SMCs, α-SMA and Desmin were co-expressed, indicating a pure smooth muscle phenotype. When progesterone was added to the culture medium, no P-SMAD1/5 expression was detected, whereas the expression Noggin and SM22, a marker of differentiated smooth muscle cells, increased by 3 fold (p=0.002) and 4.3 fold (p=0.001), respectively (p=0.002). Our results suggest that, in non-menopausal normal human myometrium, the BMP pathway might be inhibited and that this inhibition might be enhanced by progesterone, which increases the differentiation of smooth muscle cells (SM22 levels). These findings could help in the identification of new mechanisms that regulate uterine motility.

Aphtes récidivants: comment faire face [How to cope with recurrent aphthous stomatitis].

Recurrent aphthous stomatitis (RAS) is the most common oral mucosa ailment. This condition is frequently considered as idiopathic due to the doubts about its etiology, probably related to a minor immunological dysregulation in a context of genetic predisposition. However, ulcers that resemble recurrent aphthous stomatitis in some respects can be found in systemic disorders that must be ruled out for the differential diagnosis of SAR, particularly when they appear after adolescence and/or when associated lesions exist out of the oral cavity. SAR management lies on the elimination of predisposing factors (drugs, oral trauma, food allergies...) and if needed, topical corticosteroids are the first choice regimen. More severe cases may require systemic regimens.

Gut permeability and food allergies.

Intestinal permeability is a critical feature of the gastrointestinal epithelium as it must allow an efficient passage of nutrients and restrict the entry of larger molecules, such as protein antigen, in order to facilitate appropriate immune responses towards food antigens. The proper regulation of the epithelial barrier relies on multiple, intricate physiological and immunologic mechanisms, in terms of which recent progresses regarding the cellular and molecular components have been unravelled. In genetically predisposed individuals, breakdown of oral tolerance can occur, leading to the inadequate production of allergen-specific IgE and the recruitment of mast cells in the gastrointestinal mucosa. Under such conditions, the intestinal permeability towards allergen is altered via different mechanisms, with IgE-CD23-mediated transport across the mucosa playing an important amplification role. Additionally, during the effector phase of the allergic reaction, when mast cells degranulate, a series of inflammatory mediators, such as proteases and cytokines, are released and further affects intestinal permeability. This leads to an increase in the passage of allergens and hence contributes to perpetuate the inflammatory reaction. In this review, we describe the importance of properly balanced intestinal permeability in oral tolerance induction and address the processes involved in damaging the intestinal barrier in the sensitized epithelium and during allergic reactions. We conclude by speculating on the effect of increased intestinal permeability on the onset of sensitization towards dietary antigens.

Minor salivary gland tumors: a clinicopathological study of 18 cases

Introduction: Minor salivary gland tumors (MSGTs) are infrequent, representing 10-15% of all salivary neoplasms. Despite this low frequency, MSGTs conform a heterogeneous group of neoplasms characterized by a broad range of histological types. Patients and method: We identified cases of MSGT in a retrospective study of the biopsies made in the period 1997-2007 in the Service of Oral Surgery (Dental Clinic of the University of Barcelona, Spain). The data collected comprised patient age and sex, the clinical characteristics and location of the tumor, the duration of the lesion, its size, the treatment provided, and the histopathological findings. Results: Of the 18 cases of MSGT studied, 12 corresponded to women (66.7%) and 6 to men (33.3%). The great majority (94.4%) were benign tumors. The preferential location was the posterior third of the hard palate (33.2%), followed by the soft palate (16.7%) and the mucosa of the upper lip (16.7%). The histopathological diagnoses of our MSGTs comprised 10 pleomorphic adenomas (55.3%), 2 cystadenomas (11.1%), 1 myoepithelioma (5.6%), 1 sialadenoma papilliferum (5.6%), 1 basal cell adenoma (5.6%), 1 Warthin"s tumor (5.6%), 1 canalicular adenoma (5.6%), and 1 low-grade polymorphic adenocarcinoma (5.6%). Discussion and conclusions: Coinciding with our own results, the literature describes a high recurrence rate for MSGTs (5-30%) when surgical removal is incomplete. Six percent of all benign minor salivary gland tumors are considered to relapse, versus 65% of all malignant lesions. Periodic clinical controls are required, since the possibility of malignant transformation must be taken into account

Extensive (8 to 12 cm2) noncircumferential endoscopic mucosal resection for early esophageal cancer.

Background: Endoscopic mucosal resection (EMR) is an appealing method for treating intramucosal esophageal cancer but must comply with the following stringent requirements: proper preoperative staging, complete resection of the lesion, obtaining a resected specimen for histologic analysis of safety margins, and squamous reepithelialization without stricture formation. Methods: A rigid esophagoscope was created to resect up to 12 cm(2) of esophageal mucosa in a single specimen and at a constant depth through the submucosa. Under visual control, the esophageal mucosa is sucked into a transparent window and resected with a thin diathermy wire loop in 10 seconds. After extensive preclinical studies in a sheep model, this article reports our early experience in humans. Results: Twenty-one hemi-circumferential EMRs were performed for 11 dysplastic Barrett's esophagi and 10 early squamous cell carcinomas with no perforation, one hemorrhage controlled by embolization of the left gastric artery, and one incomplete resection. Deep safety margins were clear in 19 of 21 resected specimens (2 patients, unfit for operations, had submucosal invasion of squamous cell carcinoma and adenocarcinoma, respectively). Lateral margins were not clear by definition in 7 circumferential Barrett's esophagi, but were clear in 4 incomplete Barrett's esophagi and 10 early squamous cell carcinomas. Conclusions: Large EMRs of 12 cm(2) can safely be performed at the submucosal level in the esophagus. Although feasible in one session, circumferential EMR in humans is not yet advisable because of the risk of stricture formation during the healing phase. The rate of complications of this series of 21 EMRs in humans is acceptable. (Ann Thorac Surg 2010; 89: S2151-5) (C) 2010 by The Society of Thoracic Surgeons

Un diagnostic de maladie coeliaque peut en cacher un autre [A diagnosis of coeliac disease can hide an alternative diagnosis]

The Common variable Immunodeficiency (CVID) is next to the selective IgA-deficiency the most frequent primary immunodeficiency syndrome. Because of its variable clinical manifestations and age of declaration, CVID can mimic different other pathologies and is therefore frequently diagnosed in a later stage of the disease. However, as a consequence of late diagnosis, irreversible organ damage can have occurred which could have been prevented by early treatment. Therefore, early diagnosis of CVID by the general practitioner in patients with recurrent infections or other typical clinical manifestations is of great importance.

Application of ultrasound in bone surgery: two case reports

The present study describes some of the applications of ultrasound in bone surgery, based on the presentation of two clinical cases. The Piezosurgery® ultrasound device was used (Tecnología Mectron Medical, Carasco, Italy). In one case the instrument was used to harvest a chin bone graft for placement in a bone defect at level 1.2, while in the other case a bony window osteotomy was made in the external wall of the maxillary sinus, in the context of a sinus membrane lift procedure. The Piezosurgery® device produces specific ultrasound frequency modulation (25-29 kHz), and has been designed to secure increased precision in application to bone surgery. This instrument produces selective sectioning of the mineralized bone structures, and causes less intra- and postoperative bleeding. One of the advantages of the Piezosurgery® device is that it can be used for maxillary sinus lift procedures in dental implant placement. In this context it considerably lessens the risk of sinus mucosa laceration by preparing the bony window in the external wall of the upper maxilla, and can be used to complete the lifting maneuver. The use of ultrasound in application to hard tissues can be regarded as a slow technique compared with the conventional rotary instruments, since it requires special surgical skill and involves a certain learning curve.

hTERT methylation is necessary but not sufficient for telomerase activity in colorectal cells

Colorectal cancers exhibit a high telomerase activity, usually correlated with the hypermethylation of the promoter of its hTERT catalytic subunit. Although telomerase is not expressed in normal tissue, certain proliferative somatic cells such as intestinal crypt cells have demonstrated telomerase activity. The aim of this study was to determine whether a correlation exists between telomerase activity, levels of hTERT methylation and telomere length in tumoral and normal colorectal tissues. Tumor, transitional and normal tissues were obtained from 11 patients with a colorectal cancer. After bisulfite modification of genomic DNA, hTERT promoter methylation was analyzed by methylation-sensitive single-strand conformation analysis (MS-SSCA). Telomerase activity and telomere length were measured by a fluorescent-telomeric repeat amplification protocol assay and by Southern blotting, respectively. A significant increase of hTERT methylation and telomerase activity, and a reduction of the mean telomere length were observed in the tumor tissues compared to the transitional and normal mucosa. In the transitional and normal mucosa, telomerase activity was significantly lower than that in tumor tissues, even with high levels of hTERT methylation. Nevertheless, hTERT promoter methylation was not linearly correlated to telomerase activity. These data indicate that hTERT promoter methylation is a necessary event for hTERT expression, as is telomerase activity. However, methylation is not sufficient for hTERT activation, particularly in normal colorectal cells.