Transplantation of embryonic spleen tissue reveals a role for adult non-lymphoid cells in initiating lymphoid tissue organization

In this report we describe a transplantation system where embryonic spleens are grafted into adult hosts. This model can be used to analyze the cellular and molecular requirements for the development and organization of splenic microenvironments.Whole embryonic day 15 (ED15) spleens, grafted under the kidney capsule of adult mice, were colonized by host-derived lymphocytes and DC and developed normal splenic architecture. Grafts were also able to form germinal centers in response to T-dependent antigen. Using this system we demonstrated that adult host-derived lymphotoxin (LT) a was sufficient for the development of ED15 LTa/ grafts. Grafting of ED15 LTa/ spleens into RAG/ hosts followed by transfer of LT a/ splenocytes revealed no requirement for lymphocyte-derived LT a in the induction of CCL21 or the development of T-zone stroma. These data suggest that interactions between adult lymphoid-tissue inducer-like cells and embryonic stromal cells initiated T-zone development. Furthermore,adult lymphoid tissue inducer-like cells were shown to develop from bone marrow-derived progenitors. The model described here demonstrates a method of transferring whole splenic microenvironments and dissecting the stromal and hematopoietic signals involved in spleen development and organization

Pbx loss in cranial neural crest, unlike in epithelium, results in cleft palate only and a broader midface.

Orofacial clefting represents the most common craniofacial birth defect. Cleft lip with or without cleft palate (CL/P) is genetically distinct from cleft palate only (CPO). Numerous transcription factors (TFs) regulate normal development of the midface, comprising the premaxilla, maxilla and palatine bones, through control of basic cellular behaviors. Within the Pbx family of genes encoding Three Amino-acid Loop Extension (TALE) homeodomain-containing TFs, we previously established that in the mouse, Pbx1 plays a preeminent role in midfacial morphogenesis, and Pbx2 and Pbx3 execute collaborative functions in domains of coexpression. We also reported that Pbx1 loss from cephalic epithelial domains, on a Pbx2- or Pbx3-deficient background, results in CL/P via disruption of a regulatory network that controls apoptosis at the seam of frontonasal and maxillary process fusion. Conversely, Pbx1 loss in cranial neural crest cell (CNCC)-derived mesenchyme on a Pbx2-deficient background results in CPO, a phenotype not yet characterized. In this study, we provide in-depth analysis of PBX1 and PBX2 protein localization from early stages of midfacial morphogenesis throughout development of the secondary palate. We further establish CNCC-specific roles of PBX TFs and describe the developmental abnormalities resulting from their loss in the murine embryonic secondary palate. Additionally, we compare and contrast the phenotypes arising from PBX1 loss in CNCC with those caused by its loss in the epithelium and show that CNCC-specific Pbx1 deletion affects only later secondary palate morphogenesis. Moreover, CNCC mutants exhibit perturbed rostro-caudal organization and broadening of the midfacial complex. Proliferation defects are pronounced in CNCC mutants at gestational day (E)12.5, suggesting altered proliferation of mutant palatal progenitor cells, consistent with roles of PBX factors in maintaining progenitor cell state. Although the craniofacial skeletal abnormalities in CNCC mutants do not result from overt patterning defects, osteogenesis is delayed, underscoring a critical role of PBX factors in CNCC morphogenesis and differentiation. Overall, the characterization of tissue-specific Pbx loss-of-function mouse models with orofacial clefting establishes these strains as unique tools to further dissect the complexities of this congenital craniofacial malformation. This study closely links PBX TALE homeodomain proteins to the variation in maxillary shape and size that occurs in pathological settings and during evolution of midfacial morphology

Determinants of postnatal spleen tissue regeneration and organogenesis

Abstract The spleen is an organ that filters the blood and is responsible for generating blood-borne immune responses. It is also an organ with a remarkable capacity to regenerate. Techniques for splenic auto-transplantation have emerged to take advantage of this characteristic and rebuild spleen tissue in individuals undergoing splenectomy. While this procedure has been performed for decades, the underlying mechanisms controlling spleen regeneration have remained elusive. Insights into secondary lymphoid organogenesis and the roles of stromal organiser cells and lymphotoxin signalling in lymph node development have helped reveal similar requirements for spleen regeneration. These factors are now considered in the regulation of embryonic and postnatal spleen formation, and in the establishment of mature white pulp and marginal zone compartments which are essential for spleen-mediated immunity. A greater understanding of the cellular and molecular mechanisms which control spleen development will assist in the design of more precise and efficient tissue grafting methods for spleen regeneration on demand. Regeneration of organs which harbour functional white pulp tissue will also offer novel opportunities for effective immunotherapy against cancer as well as infectious diseases

Análise do comportamento e da resistência de um sistema de lajes com fôrma de aço incorporada

The objective of this thesis is to analyze the behavior and strength of composite slabs with ribbed decking built with steel deck MF-50, manufactured by METFORM S. A., after concrete has been cured. A series of tests was conducted to identify and evaluate the parameters that affect this composite slab performance. The experimental program consisted of tests in 16 full scale slabs built with different height and span as well as deck thickness. The slabs were single span and were tested according international design codes for composite slabs. The analysis of the test results is based on load × endslip load × midspan deflection and load × midspan deck strains relationships. A single mode of failure was obtained in all tests: shear bond. Based on these test results, the slabs design strength for this failure mode was determined according to the m e k method and partial interaction method.O objetivo deste trabalho é analisar o comportamento e a resistência de um sistema de laje mista com fôrma de aço incorporada, empregando o steel-deck MF-50 fabricado pela METFORM S. A., durante todas as fases do carregamento após a cura do concreto. Para isto foi realizado um programa de ensaios de laboratório a fim de se identificar e avaliar os vários parâmetros que influenciam as características globais de resistência deste sistema de laje mista. Esse programa consistiu de ensaios em 16 protótipos fabricados em escala natural com diferentes alturas de laje, vãos e espessuras da fôrma de aço incorporada. As lajes foram testadas na condição de simplesmente apoiadas seguindo as recomendações de normas internacionais. As análises dos resultados dos ensaios foram feitas considerando-se as curvas: carga × deslizamento relativo de extremidade, carga × flecha no meio do vão e carga × deformação no aço, que possibilitou conhecer o comportamento do sistema misto e definir precisamente o seu modo de colapso: cisalhamento longitudinal. Expressões analíticas para o cálculo da capacidade última das lajes para este modo de colapso foram determinadas através do método semi-empírico m e k e do método da interação parcial

A Pbx1-dependent genetic and transcriptional network regulates spleen ontogeny

The genetic control of cell fate specification, morphogenesis and expansion of the spleen, a crucial lymphoid organ, is poorly understood. Recent studies of mutant mice implicate various transcription factors in spleen development, but the hierarchical relationships between these factors have not been explored. In this report, we establish a genetic network that regulates spleen ontogeny, by analyzing asplenic mice mutant for the transcription factors Pbx1, Hox11 (Tlx1), Nkx3.2 (Bapx1) and Pod1 (capsulin, Tcf21). We show that Hox11 and Nkx2.5, among the earliest known markers for splenic progenitor cells, are absent in the splenic anlage of Pbx1 homozygous mutant (-/-) embryos, implicating the TALE homeoprotein Pbx1 in splenic cell specification. Pbx1 and Hox11 genetically interact in spleen formation and loss of either is associated with a similar reduction of progenitor cell proliferation and failed expansion of the splenic anlage. Chromatin immunoprecipitation assays show that Pbx1 binds to the Hox11 promoter in spleen mesenchymal cells, which co-express Pbx1 and Hox11. Furthermore, Hox11 binds its own promoter in vivo and acts synergistically with TALE proteins to activate transcription, supporting its role in an auto-regulatory circuit. These studies establish a Pbx1-Hox11-dependent genetic and transcriptional pathway in spleen ontogeny. Additionally, we demonstrate that while Nkx3.2 and Pod1 control spleen development via separate pathways, Pbx1 genetically regulates key players in both pathways, and thus emerges as a central hierarchical co-regulator in spleen genesis

Parvovirus and distemper - the serious gastroenteritis viral / Parvovirose e cinomose – as graves gastroenterites virais

Viruses, in their great majority, have the serious capacity to be easily transmitted through countless carriers. The great concern is due to the fact that they are able to promote critical conditions that threaten animal body homeostasis, inducing serious pathological conditions such as vomiting and diarrhea. Parvovirus is characterized by being a serious disease that affects a large part of the young animal population due to numerous reasons such as the nonexistence or lack of immunity right when they are born. Affected animals have very serious enteric conditions, which often lead the animal to death quickly. Canine distemper, caused by the canine distemper virus, causes enteric conditions and mainly neurological conditions, promoting diarrhea and nervous symptoms such as cases of paralysis and incoordination of the affected members. Diseases, if detected in time, enable effective therapeutic, control and prevention measures that can increase the life expectancy of the affected animals and, in some cases, cure patients

Artificial Diuresis: animal studies on efficacy and safety of a new miniaturized device for extracorporeal ultrafiltration

Introduction. We have recently developed a new miniaturized device for extracorporeal ultrafiltration to be used in patients with fluid overload: Artificial Diuresis-1, or AD1 (Medica S.p.A., Medolla, Italy). The device has a reduced priming volume and operates at very low pressure and flow regimes and is designed to perform extracorporeal UF at bedside. After accurate experiments carried out in vitro, we report in this paper the results of in vivo tests ultrafiltration session carried out in selected animals according to veterinary best practice. Materials and methods. The AD1 kit is pre-filled with sterile isotonic solution and operates with a polysulfone mini-filter MediSulfone (Polysulfone at 50000 Dalton). A collection bag with a volumetric scale is connected to the UF line and the ultrafiltrate is obtained by gravity based on the height at which the ultrafiltrate collection bag is placed. Animals were prepared and anesthetized. Jugular vein was cannulated with a double lumen catheter. Three six hours sessions of ultrafiltration were scheduled with a target fluid removal of 1500 ml. Heparin was used as anticoagulant.Results. In all treatments the target value of ultrafiltration was obtained in the absence of major clinical or technical problems with a maximum deviation from the scheduled ultrafiltration rate lower than 10%. The device resulted safe, reliable, accurate and easily usable thanks to a user friendly interface and the very small dimensions. Conclusions. This study opens the way for clinical trials in different settings including departments with low intensity of care and even in ambulatory centers or patient's home

Intra-parenchymal renal resistive index variation (IRRIV) describes renal functional reserve (RFR): Pilot study in healthy volunteers

An increase of glomerular filtration rate after protein load represents renal functional reserve (RFR) and is due to afferent arteriolar vasodilation. Lack of RFR may be a risk factor for acute kidney injury (AKI), but is cumbersome to measure. We sought to develop a non-invasive, bedside method that would indirectly measure RFR. Mechanical abdominal pressure, through compression of renal vessels, decreases blood flow and activates the auto-regulatory mechanism which can be measured by a fall in renal resistive index (RRI). The study aims at elucidating the relationship between intra-parenchymal renal resistive index variation (IRRIV) during abdominal pressure and RFR. In healthy volunteers, pressure was applied by a weight on the abdomen (fluid-bag 10% of subject's body weight) while RFR was measured through a protein loading test. We recorded RRI in an interlobular artery after application of pressure using ultrasound. The maximum percentage reduction of RRI from baseline was compared in the same subject to RFR. We enrolled 14 male and 16 female subjects (mean age 38 ± 14 years). Mean creatinine clearance was 106.2 ± 16.4 ml/min/1.73 m2. RFR ranged between -1.9 and 59.7 with a mean value of 28.9 ± 13.1 ml/min/1.73 m2. Mean baseline RRI was 0.61 ± 0.05, compared to 0.49 ± 0.06 during abdominal pressure; IRRIV was 19.6 ± 6.7%, ranging between 3.1% and 29.2%. Pearson's coefficient between RFR and IRRIV was 74.16% (p < 0.001). Our data show the correlation between IRRIV and RFR. Our results can lead to the development of a "stress test" for a rapid screen of RFR to establish renal susceptibility to different exposures and the consequent risk for AKI