Digestion capasity, nutrient digestibilities and physico-chemical conditions in the intestine influenced by the age of growing turkeys

Six experiments have been conducted to examine digestibility and feeding value of domestic Finnish fibre-rich cereals (barley and oats as compared to maize and wheat) and protein sources (rapeseed meal and cake, peas, faba beans, lupin seeds) for growing turkeys and to investigate effects of age of the birds (from 3 to 12 weeks of age) on digestion process and estimated nutrient digestibility and energy values. Besides, an objective of the study was to test applications of digestibility research methodology for turkeys. Total tract digestibility and apparent metabolizable energy (AME) was assayed in experimental cages using excreta collection, and a slaughter method was applied to sample small intestinal digesta for determination of apparent ileal crude protein digestibility (AICPD), jejuno-duodenal digesta viscosity and caecal volatile fatty acid (VFA) concentration. Digesta viscosity decreased and caecal VFA production increased with age of growing turkeys. Digesta retention times in the small intestine were generally longer in the older birds than in the younger ones. Crude fat digestibility and AME increased with age of growing turkeys, especially with viscous diets. AICPD seemed to decrease with age in most cases. Supplementation with β-gucanase-xylanase decreased viscosity, improved crude fat digestibility and metabolizable energy value and increased VFA production especially in barley-fed turkeys and especially in the young birds. Poor protein digestibility and low energy value of rapeseed meal and rapeseed cake decreased their feeding value for turkeys. In addition, a typical goitrogenic effect of rapeseed feeding was detected. Use of legume seeds as feed for growing turkeys is limited mostly by the low energy value in lupin seeds and the low ileal protein and amino acid digestibility in faba beans. Digestibility of fibre-rich protein sources was not improved with age of the turkeys. Euthanizing the turkeys for AICPD determination by carbon dioxide and bleeding led to lower digestibility values than mechanical stunning and cervical dislocation, suggesting inferiority of carbon dioxide stunning in experimental use. Comparison of AICPD and AME results obtained using different markers showed that considerable differences may occur, especially on total tract level, when acid-insoluble ash gave considerably lower AME values than titanium dioxide and chromic oxide.

Specific requirement of lysophosphatidylcholine for palmitoyl-CoA synthetase of chicken intestine

The presence of palmitoyl-CoA synthetase (EC 6.2.1.3) in the brush borderfree particulate fraction of chicken intestinal mucosa is demonstrated. The enzyme was dependent on the simultaneous presence of lysophosphatidylcholine and Triton X-100 as well as ATP, CoA and Mg2+ for maximal activity. Lysophosphatidylcholine could not be replaced by other lipids. Enzyme preparations solubilized by Triton X-100 or lysophosphatidylcholine were still dependent on the presence of detergents for maximal activity.

Fine-tuning of the signalling network controlling morphogenesis and stem cell development in teeth

Tooth development is regulated by sequential and reciprocal interactions between epithelium and mesenchyme. The molecular mechanisms underlying this regulation are conserved and most of the participating molecules belong to several signalling families. Research focusing on mouse teeth has uncovered many aspects of tooth development, including molecular and evolutionary specifi cs, and in addition offered a valuable system to analyse the regulation of epithelial stem cells. In mice the spatial and temporal regulation of cell differentiation and the mechanisms of patterning during development can be analysed both in vivo and in vitro. Follistatin (Fst), a negative regulator of TGFβ superfamily signalling, is an important inhibitor during embryonic development. We showed the necessity of modulation of TGFβ signalling by Fst in three different regulatory steps during tooth development. First we showed that tinkering with the level of TGFβ signalling by Fst may cause variation in the molar cusp patterning and crown morphogenesis. Second, our results indicated that in the continuously growing mouse incisors asymmetric expression of Fst is responsible for the labial-lingual patterning of ameloblast differentiation and enamel formation. Two TGFβ superfamily signals, BMP and Activin, are required for proper ameloblast differentiation and Fst modulates their effects. Third, we identifi ed a complex signalling network regulating the maintenance and proliferation of epithelial stem cells in the incisor, and showed that Fst is an essential modulator of this regulation. FGF3 in cooperation with FGF10 stimulates proliferation of epithelial stem cells and transit amplifying cells in the labial cervical loop. BMP4 represses Fgf3 expression whereas Activin inhibits the repressive effect of BMP4 on the labial side. Thus, Fst inhibits Activin rather than BMP4 in the cervical loop area and limits the proliferation of lingual epithelium, thereby causing the asymmetric maintenance and proliferation of epithelial stem cells. In addition, we detected Lgr5, a Wnt target gene and an epithelial stem cell marker in the intestine, in the putative epithelial stem cells of the incisor, suggesting that Lgr5 is a marker of incisor stem cells but is not regulated by Wnt/β-catenin signalling in the incisor. Thus the epithelial stem cells in the incisor may not be directly regulated by Wnt/β-catenin signalling. In conclusion, we showed in the mouse incisors that modulating the balance between inductive and inhibitory signals constitutes a key mechanism regulating the epithelial stem cells and ameloblast differentiation. Furthermore, we found additional support for the location of the putative epithelial stem cells and for the stemness of these cells. In the mouse molar we showed the necessity of fi ne-tuning the signalling in the regulation of the crown morphogenesis, and that altering the levels of an inhibitor can cause variation in the crown patterning.

Epithelial sodium channel in airway epithelium of the newborn infant : Implications for postnatal pulmonary adaptation

The aim of the present thesis was to study the role of the epithelial sodium channel (ENaC) in clearance of fetal lung fluid in the newborn infant by measurement of airway epithelial expression of ENaC, of nasal transepithelial potential difference (N-PD), and of lung compliance (LC). In addition, the effect of postnatal dexamethasone on airway epithelial ENaC expression was measured in preterm infants with bronchopulmonary dysplasia (BPD). The patient population was formed of selected term newborn infants born in the Department of Obstetrics (Studies II-IV) and selected preterm newborn infants treated in the neonatal intensive care unit of the Hospital for Children and Adolescents (Studies I and IV) of the Helsinki University Central Hospital in Finland. A small population of preterm infants suffering from BPD was included in Study I. Studies I, III, and IV included airway epithelial measurement of ENaC and in Studies II and III, measurement of N-PD and LC. In Study I, ENaC expression analyses were performed in the Research Institute of the Hospital for Sick Children in Toronto, Ontario, Canada. In the following studies, analyses were performed in the Scientific Laboratory of the Hospital for Children and Adolescents. N-PD and LC measurements were performed at bedside in these hospitals. In term newborn infants, the percentage of amiloride-sensitive N-PD, a surrogate for ENaC activity, measured during the first 4 postnatal hours correlates positively with LC measured 1 to 2 days postnatally. Preterm infants with BPD had, after a therapeutic dose of dexamethasone, higher airway epithelial ENaC expression than before treatment. These patients were subsequently weaned from mechanical ventilation, probably as a result of the clearance of extra fluid from the alveolar spaces. In addition, we found that in preterm infants ENaC expression increases with gestational age (GA). In preterm infants, ENaC expression in the airway epithelium was lower than in term newborn infants. During the early postnatal period in those born both preterm and term airway epithelial βENaC expression decreased significantly. Term newborn infants delivered vaginally had a significantly smaller airway epithelial expression of αENaC after the first postnatal day than did those delivered by cesarean section. The functional studies showed no difference in N-PD between infants delivered vaginally and by cesarean section. We therefore conclude that the low airway epithelial expression of ENaC in the preterm infant and the correlation of N-PD with LC in the term infant indicate a role for ENaC in the pathogenesis of perinatal pulmonary adaptation and neonatal respiratory distress. Because dexamethasone raised ENaC expression in preterm infants with BPD, and infants were subsequently weaned from ventilator therapy, we suggest that studies on the treatment of respiratory distress in the preterm infant should include the induction of ENaC activity.

Expression of GC-C, a receptor-guanylate cyclase, and its endogenous ligands uroguanylin and guanylin along the rostrocaudal axis of the intestine

Members of the receptor-guanylate cyclase (rGC) family possess an intracellular catalytic domain that is regulated by an extracellular receptor domain. GC-C, an intestinally expressed rGC, was initially cloned by homology as an orphan receptor. The search for its Ligands has yielded three candidates: STa (a bacterial toxin that causes traveler's diarrhea) and the endogenous peptides uroguanylin and guanylin. Here, by performing Northern and Western blots, and by measuring [I-125]STa binding and STa-dependent elevation of cGMP levels, we investigate whether the distribution of GC-C matches that of its endogenous ligands in the rat intestine. We establish that 1) uroguanylin is essentially restricted to small bowel; 2) guanylin is very low in proximal small bowel, increasing to prominent levels in distal small bowel and throughout colon; 3) GC-C messenger RNA and STa-binding sites are uniformly expressed throughout the intestine; and 4) GC-C-mediated cGMP synthesis peaks at the proximal and distal extremes of the intestine (duodenum and colon), but is nearly absent in the middle (ileum). These observations suggest that GC-C's activity may be posttranslationally regulated, demonstrate that the distribution of GC-C is appropriate to mediate the actions of both uroguanylin and guanylin, and help to refine current hypotheses about the physiological role(s) of these peptides.

Tumorigenesis in celiac disease

Celiac disease is life-long autoimmune disorder of the small intestine, which is caused by a reaction to gliadin found in wheat, rye and barley in genetically predisposed individuals. Proline- and glutamine -rich proteins cause villous atrophy and crypt hyperplasia with extensive inflammation in the epithelium and lamina propria. Symptoms of celiac disease vary considerably and elimination of gluten from diet is the only way to treat disease. In small intestine of celiac disease patient transglutaminase 2 (TG2) modifies gluten peptides, which causes T-cell activation and inflammation in the epithelium of mucosa. T-cell activation induces development of celiac disease specific antibodies. These celiac disease specific antibodies recognise TG2 and interfere in vitro and in vivo in angiogenesis. Abnormal angiogenesis is typical in many disorders, such in cancer, in which TG2 has a crucial role in the development and growth of tumor. Overexpression of TG2 has been shown to correlate with accelerated growth of tumor. TG2-specific antibodies are suggested to inhibit differentation of epithelial cell, increase their proliferation, decrease their barrier-function and increase the permeability of blood vessels. The aims of the pilot study were to establish whether celiac disease TG2 antibodies affect in vivo tumorigenesis and tumorangiogenesis as well as to try to clarify the mechanism behind the phenomenon. Tumor xenograft model was used in severe combined immunodeficient (SCID) mice. Human oesophageal carcinoma (OE-19) cancer cells were incubated with celiacs TG2 miniautoantibody (mini 2.8), non-celiac miniautoantibody (mini 6.2) or PBS before cancer cells were injected to mice subcutaneously. During the experiment mice were weighted and tumor size was measured couple of times per week. To estimate the volumes of tumors the following formula was used: π/6 * L* W* H. Experiment lasted for four weeks after which the mice were euthanized, cardiac blood and tissue samples taken and tumours were excised and weighted. Sections were made from tumors and immunohistochemical stainings were done to compare blood vessel areas and to study general tumors´morphology and other parameters. Western blot -analyse were performed to cancer cells. The masses and volumes were clearly smaller in mini 2.8-group compared to control groups and the necrotic area of tumor in mini 2.8 was smallest as percentage compared to control groups. Blood vessel area were smallest in mini 2.8 group. Results suggest that celiac disease anti-TG2-autoantibodies inhibit tumor growth, but the number of animals is insufficient to give an accurate outcome.

DNA damage recognition in the normal epithelium of human prostate and seminal vesicles

Prostate cancer is one of the most prevalent cancer types in men. The development of prostate tumors is known to require androgen exposure, and several pathways governing cell growth are deregulated in prostate tumorigenesis. Recent genetic studies have revealed that complex gene fusions and copy - number alterations are frequent in prostate cancer, a unique feature among solid tumors. These chromosomal aberrations are though to arise as a consequence of faulty repair of DNA double strand breaks (DSB). Most repair mechanisms have been studied in detail in cancer cell lines, but how DNA damage is detected and repaired in normal differentiated human cells has not been widely addressed. The events leading to the gene fusions in prostate cancer are under rigorous studies, as they not only shed light on the basic pathobiologic mechanisms but may also produce molecular targets for prostate cancer treatment and prevention. Prostate and seminal vesicles are part of the male reproductive system. They share similar structure and function but differ dramatically in their cancer incidence. Approximately fifty primary seminal vesicle carcinomas have been reported worldwide. Surprisingly, only little is known on why seminal vesicles are resistant to neoplastic changes. As both tissues are androgen dependent, it is a mystery that androgen signaling would only lead to tumors in prostate tissue. In this work, we set up novel ex vivo human tissue culture models of prostate and seminal vesicles, and used them to study how DNA damage is recognized in normal epithelium. One of the major DNA - damage inducible pathways, mediated by the ATM kinase, was robustly activated in all main cell types of both tissues. Interestingly, we discovered that secretory epithelial cells had less histone variant H2A.X and after DNA damage lower levels of H2AX were phosphorylated on serine 139 (γH2AX) than in basal or stromal cells. γH2AX has been considered essential for efficient DSB repair, but as there were no significant differences in the γH2AX levels between the two tissues, it seems more likely that the role of γH2AX is less important in postmitotic cells. We also gained insight into the regulation of p53, an important transcription factor that protects genomic integrity via multiple mechanisms, in human tissues. DSBs did not lead to a pronounced activation of p53, but treatments causing transcriptional stress, on the other hand, were able to launch a notable p53 response in both tissue types. In general, ex vivo culturing of human tissues provided unique means to study differentiated cells in their relevant tissue context, and is suited for testing novel therapeutic drugs before clinical trials. In order to study how prostate and seminal vesicle epithelial cells are able to activate DNA damage induced cell cycle checkpoints, we used primary cultures of prostate and seminal vesicle epithelial cells. To our knowledge, we are the first to report isolation of human primary seminal vesicle cells. Surprisingly, human prostate epithelial cells did not activate cell cycle checkpoints after DSBs in part due to low levels of Wee1A, a kinase regulating CDK activity, while primary seminal vesicle epithelial cells possessed proficient cell cycle checkpoints and expressed high levels of Wee1A. Similarly, seminal vesicle cells showed a distinct activation of the p53 - pathway after DSBs that did not occur in prostate epithelial cells. This indicates that p53 protein function is under different control mechanisms in the two cell types, which together with proficient cell cycle checkpoints may be crucial in protecting seminal vesicles from endogenous and exogenous DNA damaging factors and, as a consequence, from carcinogenesis. These data indicate that two very similar organs of male reproductive system do not respond to DNA damage similarly. The differentiated, non - replicating cells of both tissues were able to recognize DSBs, but under proliferation human prostate epithelial cells had deficient activation of the DNA damage response. This suggests that prostate epithelium is most vulnerable to accumulating genomic aberrations under conditions where it needs to proliferate, for example after inflammatory cellular damage.

Voyages and travels into Brasil and east-Indies : containing an exact description of the dutch Brasil and divers parts of the east-Indies, their provinces, cities, living creatures, and products, the manners, customs, habits and religion the inhabitants : with a particular account of all the remarkable passages that happened during the author's stay of nine years in Brasil, especially in relation to the revolt of the portugueses, and the intestine war carried on there from 1640 to 1649 : as also a most ample description of the most famous city of batavia in the east-Indies

Joan Nieuhoff, viajante alemão, nasceu em Usen, Vesfália, em 1618, e morreu em Madagascar, em 1672. Trabalhou na Companhia das Índias Orientais, foi nomeado agente em Batávia, em 1654. Em 1655, foi à China tratar da abertura dos portos daquele país ao comércio holandês. Governou o Ceilão de 1662 a 1667. Em 1672, desembarcando em Madagascar, foi morto pelos nativos.

The intestine as a diagnostic character in identifying certain clupeoids (Engraulididae, Clupeidae, Dussumieriidae) and as a morphometric character for comparing anchoveta (Centengraulis mysticetus) populations

ENGLISH: The several species of clupeoid fishes used as baitfish in the Eastern Pacific tuna fishery are, in some cases, sufficiently similar to make identification difficult. During a review of the anatomy of the intestine of clupeoid fishes it was observed that the morphology of the intestine is sometimes a useful character in the identification of systematic groups. The genera at least can be distinguished by means of the topographical anatomy of the intestines. This also may be a useful character because it is often found that a species occurs in the same area as another species that may be confused with it on external inspection, although it belongs to a different genus. SPANISH: La gran similitud morfológica de varias especies del órden Clupeoidea usadas como cebo en la pesquería de atún del Pacifíco Oriental, hace que su identificación sea en algunos casos difícil. Al realizar una revisión anatómica del intestino de los peces clupeoides, se observó que la morfología del mismo es a veces un carácter útil para la identificación de los diversos grupos sistemáticos. Al menos los géneros pueden ser distinguidos por medio de la anatomía topográfica de los intestinos. Esto también puede ser un carácter útil, puesto que a menudo dos especies pertenecientes a géneros diferentes y que ocupen la misma área, pueden ser confundidos si nos basamos solamente en la morfología externa. (PDF contains 24 pages.)

Efeito da L-Arginina e Glicina na parede do cólon irradiado Estudo experimental em ratos

A radioterapia é amplamente utilizada no tratamento de tumores pélvicos, incluindo os de bexiga, intestino e reto. Ela apresenta efeitos danosos, notadamente em tecidos que apresentam intensa renovação celular, sendo a mucosa intestinal altamente susceptível. Nesse contexto, a suplementação dietética com aminoácidos tem se mostrado uma terapia promissora para minimizar este dano. O objetivo desse estudo foi determinar o efeito da suplementação dietética com os aminoácidos L-arginina e glicina na estrutura da parede do cólon de ratos submetidos a irradiação abdominal. Quarenta ratos Wistar machos adultos foram distribuídos aleatoriamente em quatro grupos, cada um com dez animais: I controle não irradiado e sem suplementação de aminoácidos; II controle irradiado e sem suplementação de aminoácidos; III irradiado e suplementado com L-arginina; IV irradiado e suplementado com glicina. O período de suplementação dietética foi de 14 dias, com a irradiação ocorrendo no 8. dia do experimento. A análise estereológica mostrou que a irradiação provocou diminuição do volume total da parede colônica dos animais dos grupos II e III em relação aos animais saudáveis, mas não dos ratos que receberam suplementação de glicina. A camada mucosa dos animais irradiados de todos os grupos diminuiu quando comparada com os ratos saudáveis não irradiados. Os animais irradiados que não receberam suplementação de aminoácido apresentaram diminuição da camada muscular da mucosa, quando comparados com os grupos I e IV, e o grupo de ratos suplementados com glicina apresentou aumento significativo da camada submucosa em relação aos grupos I e II. Os animais do grupo III mostraram diminuição da camada muscular própria em comparação aos grupos I e IV. A suplementação com L-arginina foi eficaz na manutenção do volume parcial do epitélio da camada mucosa. Nossos resultados sugerem que a suplementação de glicina apresentou efeitos superiores ao da suplementação com L-arginina na estrutura da parede colônica, haja vista que foi capaz de manter a espessura da parede e a superfície epitelial da mucosa, enquanto a Larginina foi capaz de manter o volume parcial do epitélio e a superfície epitelial, mas não o volume total da parede intestinal.

Gen LPP : Avances en el conocimiento de uno de los genes candidato de la enfermedad celíaca

[ES] La enfermedad celíaca (EC) es una enteropatía autoinmune de predisposición genética, producida por la ingestión en la dieta de péptidos derivados de cereales como el trigo o la cebada. Aunque se creía que afectaba casi de forma exclusiva a los individuos europeos (1%), actualmente se conocen casos en todo el mundo. El modelo patogénico se centra en los mecanismos de la inmunidad adaptativa dependientes de la estimulación de linfocitos T CD4+ reactivos, pero existe además un efecto tóxico directo del gluten sobre el epitelio intestinal, dependiente de la inmunidad innata. La participación de la Genética en la susceptibilidad a la enfermedad es conocida desde hace tiempo, siendo el locus HLA el que explica aproximadamente el 40% del componente genético de la enfermedad. Para tratar de identificar otros genes con susceptibilidad, se han venido realizando múltiples esfuerzos durante los últimos años. Uno de los últimos, llevado a cabo en 2011, fue el Proyecto Immunochip. En él, se analizaron más de 200.000 variantes y se descubrieron 13 nuevos loci de riesgo para la EC, que junto con los descubiertos en anteriores trabajos y el locus HLA, daban un total de 40 loci de riesgo. Entre ellos, se encontraba la región que ocupa el gen LPP . Localizado en el cromosoma 3, un estudio reciente lo vincula con los procesos de adhesión celular en el intestino. En el presente trabajo, se ha estudiado el efecto de la gliadina sobre la expresión del gen de interés (LPP ) y el posible efecto de un silenciamiento del mismo sobre dos genes relacionados con las uniones celulares (ACTB y TJP1). En el caso de la gliadina, no se halló un cambio significativo en la expresión del gen. Mientras, los resultados del efecto del silenciamiento fueron dispares, no siendo concluyentes para el gen ACTB, pero encontrando una posible asociación entre los genes LPP y TJP1.