Younger age at onset and sex predict celiac disease in children and adolescents with type 1 diabetes: an Italian multicenter study

OBJECTIVE— To estimate the prevalence of biopsy-confirmed celiac disease in Italian children and adolescents with type 1 diabetes and to assess whether age at onset of type 1 diabetes is independently associated with diagnosis of celiac disease. RESEARCH DESIGNANDMETHODS— The study group was a clinic-based cohort of children and adolescents with type 1 diabetes cared for in 25 Italian centers for childhood diabetes. Yearly screening for celiac disease was performed using IgA/IgG anti-gliadin and IgA anti-endomysium antibodies. RESULTS— Of the 4,322 children and adolescents (age 11.8 4.2 years) identified with type 1 diabetes, biopsy-confirmed celiac disease was diagnosed in 292 (prevalence 6.8%, 95% confidence interval [CI] 6.0 –7.6), with a higher risk seen in girls than in boys (odds ratio [OR] 1.93, 1.51–2.47). In 89% of these, diabetes was diagnosed before celiac disease. In logistic regression analyses, being younger at onset of diabetes, being female, and having a diagnosis of a thyroid disorder were independently associated with the risk of having diabetes and celiac disease. In comparison with subjects who were older than 9 years at onset of diabetes, subjects who were younger than 4 years at onset had an OR of 3.27 (2.20–4.85). CONCLUSIONS— We have provided evidence that 1) the prevalence of biopsy-confirmed celiac disease in children and adolescents with type 1 diabetes is high (6.8%); 2) the risk of having both diseases is threefold higher in children diagnosed with type 1 diabetes at age 4 years than in those age 9 years; and 3) girls have a higher risk of having both diseases than boys

Aspetti morfo-funzionali dell'epitelio digestivo in Appendicolarie (Urochordata)

Le Appendicolarie, tunicati planctonici, costruiscono ciclicamente un sistema esterno "usa e getta", molto specializzato per la cattura del cibo, svolgendo un ruolo fondamentale nel trasferimento di energia attraverso le catene trofiche degli oceani. A differenza degli ascidiacei, ben poco si conosce sul loro tubo digerente. Di questo abbiamo ora studiato l'organizzazione e l'ultrastruttura comparandole a quelle degli ascidiacei. Nelle Oikopleuridae il tubo digerente comprende un esofago tubolare, uno stomaco sacciforme suddiviso in due lobi diversificati e un intestino ad U, diviso in prossimale-medio e retto, privo di ghiandola pilorica e terminante con un ano tra i due spiracoli. Rispetto agli ascidiacei mancano le cellule mucose, le cellule endocrine, le cellule plicate e i centri proliferativi. La propulsione del cibo e la formazione dei pellet avvengono ad opera di cellule cigliate a microvili che nell'esofago producono unasecrezione densa, mentre nello stomaco e nell'intestino sono anche assorbenti e presentano profonde interdigitazioni baso-laterali di membrana associate a mitocondri con probabile ruolo di regolazione osmotica. Nello stomaco la digestione \ue8 a carico delle cellule basofile che, diversamente dalle ascidie, sono raggruppate in una banda gastrica nel lobo sinistro. Cellule a globi nello stomaco e nel retto assorbono per pinocitosi macromolecole quali la perossidasi. L'apparente semplificazione strutturale \ue8 in linea con l'economia organizzativa delle appendicolarie e permette comunque un'alta efficienza nel trattamento del cibo per soddisfare le elevate richieste energetiche del loro rapido ciclo vitale

Tissue repair during egg segregation in tunic of the compound ascidian, Diplosoma listerianum

In D. listerianum mature eggs are isoltaed in the tunic where embryos develops. The process of egg segregation was studied by light and electron microscopy. Initially the egg is contained in a sac-like pocket of the epidermis which narrows to form an ephemeral collar at its proximal end. The follicle cells discharged from the egg are retracted towards the zooid to block the aperture of the collar. The epidermis breaks close to the egg and the lips of the wound heal rapidly, enclosing the egg in the tunic and later re-establishing the epidermal continuity of the zooid. Both granulocytes form the bloodstream and epitheliocytes engulf tissue debris. Moreover, apocrine secretion of the epidermis participates in tunic restoration. The permeability barrier of the zooid seems to be assured by tight junctions, together with the plug of follicle cells

Ovulation and placentation in Botryllus schlosseri(Ascidiacea): An ultrastructural study.

The mode of ovulation and placentation was studied by light and electron microscopy in the ovoviviparous ascidian Botryllus schlosseri using colonies from the laboratory. The full-grown oocyte is surrounded by the outer and inner follicle cell layers, the acellular vitelline coat (chorion), and the test cells, and it is furnished with its own vesicular oviduct which is interposed between the egg and the atrial epithelium. In contrast to most ascidians, the outer follicle is thick and has an ultrastructure consistent with intense protein synthesis. At ovulation the outer follicle shows signs of involution where it contacts the oviduct. When the oviducal wall breaks and the egg moves through the oviduct, the outer follicle cells are discharged in the mantle to form a sort of corpus luteum. The egg remains hanging in the atrial chamber by means of a cuplike "placenta." The placental tissues are all of maternal origin, being derived from both the atrial and oviducal epithelia together with some of the inner follicle cells. These latter anchor to the oviducal epithelium by means of junctional spots and a filamentous cementing secretion. Our results suggest that the main role of the "placenta" is to attach the embryo to the parent, thus exposing it to the flow of seawater

SYNCHRONOUS SPERMATOGENESIS IN APPENDICULARIANS

Spermatogenesis was studied in appendicularians belonging to the families Fritillariidae (Fritillaria borealis, Fritillaria pellucida) and Oikopleuridae (Oikopleura dioica, Oikopleura albicans, Oikopleura longicauda). Particular attention was given to specimen of Fritillaria borealis collected in the fjord of Bergen (Norway) and to Oikopleura dioica reared in a laboratory at the Station Zoologique in Villefranche-sur-Mer. In all species, spermatogenesis proceeds in a highly synchronized way in the whole testis, thanks to the presence of syncytial structures. Two models were identified: 1) In Fritillaria borealis, the syncytium contains organelles and two populations of large and small nuclei. The large somatic nuclei produce "nuage" and occupy the center of wide cytiplasmic areas, at the periphery of which the small nuclei of the germ cells lie. As spermatogenesis progresses, large nuclei and syncytial cytoplasm reduce volume, while germ cells greatly proliferate and undergo meiosis and spermiogenesis. Lastly, the large nuclei degenerate while late spermatids, all possessing a single mitochondrion and a flagellum, segregate from the syncytium. 2) In Oikopleura dioica, the large cytoplasmic area contains most of the organelles and germ cell nuclei hanging at the periphery. Germ cells undergo series of mitosis, meiosis and spermiogenesis, whereas mitochondria migrate from the common cytoplasmic area through bridges. Lastly, the syncytial area is markedly reduced, and spermatozoa segregate and mature all together. In all species, spermatozoa are small and flagellate. They mature in great numbers and are appropriately arranged in the testis, thus exploiting to fulest extent the space for the imminent spawning

The appendicularian alimentary tract: a comparative study

Species belonging to the three families of appendicularians (Oikopleuridae, Fritillariidae, Kowalevskiidae) reveal general simplification of trunk organs, especially Fritilalriidae and Kowalevskiidae. In particular, the alimentary tract, studied by light and electron microscopy using specimens cut with complete series of sections, shows that no connective or muscle tissue accompanies the gut epithelium, and no cell-renewing regions nor endocrine-like cells can be identified. In the pharynx, the endostyle varies in complexity from Oikopleura to Fritillaria, but is absent in Kowalevskia. The post-pharyngeal tract is always composed of an oesophagus, a stomach and an intestine, the latter subdivided into two or three regions. In Oikopleura, several cell types with different functions are recognisable. In the other families, the cells are very few, mostly giant, and poorly diversified. Food passage depends upon ciliary activity. Absorption, digestion and epithelial transport are also evident. The gut tracts are always separated by valves (usually cardiac, pyloric and rectal) although their importance varies among species. In general, oikopleurids possess common features in the histology of the alimentary tract, completely distinc from fritillarids and kowalevskids, which have othe features in common

Gut ultrastructure of the appendicularian Oikopleura dioica (Tunicata)

The appendicularians, planktonic tunicates, possess a specialized, external filtering system that captures food particles <1 \u3bcm in size. In this work the alimentary canal of Oikopleura dioica has been studied by serial sections of whole animals and ultrastructure. The gut includes a dorsal esophagus, a bilobed saccular stomach, and a curved intestine, divided into vertical, mid-, and distal intestine (or rectum). No multicellular glands or cellular proliferative centers were found. Three main cell types were recognized, ciliated microvillar cells, globular cells and gastric band cells, with specializations reflecting different physiological roles in the various regions. Ciliated microvillar cells, the most diffuse, are considered to be involved in food propulsion, fecal pellet formation, absorption, and nutrient storage. Pinocytotic features and vacuoles suggest that absorption of macromolecules and intracellular digestion occur in the globular cells of the stomach and rectum. The large gastric band cells of the left lobe have typical features of intense protein synthesis and probably produce enzymes for extracellular digestion. Diffuse interdigitations of many cells enormously increase the plasmalemma surface and may be involved in liquid/ion exchange. Despite the apparent structural simplicity of the gut epithelium, O. dioica efficiently processes food to fulfill the energy requirements of its exceptionally rapid life-cycle

Toxicity of organotin compounds on embryos of a marine invertebrate (Styela plicata; Tunicata)

none5Organotin compounds are an useful class of tin chemicals, a number of which have found commercial applications and are industrially synthesized in large amounts. Their uncontrolled use may cause profound effects on the fate and long-term environmental impact in natural aquatic environments. Butyltin compounds (TBT and its degradation products, i.e. DBT and MBT) are leached out from antifouling paints; triphenyltin (TPT) and tricyclohexyltin (TCHT) compounds have source in the run off waters of treated plants on which they are use as pesticides. There is much concern about their hurtful effects on marine life, especially fish and molluscs. The lagoon of Venice is a particular coastal area with shallow and incompletely turnovering waters, in which the resident benthonic population suffers the negative impact of organotins for bioaccumulation. In order to clarify the interaction mechanism, we studied the toxic effects of organotins on a benthonic filter-feeding ascidian. We followed the embryonic development of the ascidian Styela plicata with two different approaches: i) in vivo observations on different stages of ascidian development from fertilized egg to larval stages by incubation with 0.1, 1, 10 µM organotins for various exposure times; ii) ultrastructural observations on the early embryonic stages (2-4 cells, morula, gastrula) incubated with 10 µM TBT or TPT for 1 hour. Our results show that organotins significantly affect all stages of ascidian development in a dose- and time-dependent manner and the most sensitive stages are gastrula and neurula. These compounds are able to block the development giving rise to anomalous embryos with irreversible effects. The order of inhibition appears strongly dependent on the organotin liposolubility: TBT>DBT>MBT and TPT>TCHT. The mitosis block of blastomers in the early stages may be related to an inhibition of the microtubule polymerization. Observations with light and electron microscopes reveal globe-shaped blastomers with large intercellular spaces in morula and gastrula stages, suggesting a toxic damage on aggregation of microfilaments. Moreover the occurrence of electron-dense precipitates of organotins in the inner membrane of mitochondria and morphological changes of their cristae suggests an inhibition of mitochondrial oxidative phosphorylation which is important in the gastrula stage. In this stage, these electron-dense aggregates grow from 50-70 nm to 110-170 nm and the alteration of the cristae increases.noneCIMA F.; L. BALLARIN; BRESSA G.; MARTINUCCI G.B.; BURIGHEL P.Cima, Francesca; Ballarin, Loriano; Bressa, G.; Martinucci, G. B.; Burighel, P