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The extrinsic and intrinsic respiratory nervous systems receive specific contributions from the vagal and sympathetic components. Using specific markers for vagal and sympathetic structures, we studied the distribution patterns of immunoreactivity to galanin (GAL), pituitary adenylate cyclase-activating polypeptide-27 (PACAP) and the tachykinin substance P in extrinsic and intrinsic nerve of chick embryo respiratory system, during development from the very early age to hatching. All peptides studied appeared in the intrinsic and extrinsic nervous systems early. We found substance P in both the vagal and sympathetic systems, PACAP in vagal components alone and GAL mainly in the sympathetic system. The intrinsic nervous system showed high immunoreactivity for all peptides studied. These data accord with the well known early trophic functions that peptides have on the development of nervous networks and modulatory activity on the intrinsic nervous system. The GAL again proves to be the main peptide in chick embryo sympathetic respiratory system. [ABSTRACT FROM AUTHOR]

Intestinal motility disorders are a common complication after surgery for neonatal intestinal atresia. Although intestinal atresia causes alterations in the enteric nervous system, especially in its inner structures (nervous fibers in the mucosa, submucous and deep muscular plexuses), how these alterations develop is unclear. The chick model is a useful research tool for investigating the ontogenesis of the enteric nervous system and the pathogenesis of congenital bowel diseases. More information is needed on the overlap between the developing enteric nervous system and intestinal atresia. Because vasoactive intestinal polypeptide and substance P are typical intestinal neuropeptides, and vasoactive intestinal polypeptide acts as a modulator in neurodevelopment and an inhibitor of smooth muscle cell proliferation, our aim in this study was to investigate the distribution of their immunoreactivity in the developing enteric nervous system of normal and experimental chick models. We studied gut specimens excised from normal chick embryos (aged 12-20 days) and experimental chick embryos (aged 15-20 days) that underwent surgical intervention on day 12 to induce intestinal atresia (atresic embryos) or simply to grasp the bowel loop (sham-operated embryos). In normal chick embryos we showed vasoactive intestinal polypeptide and substance P immunoreactivity from day 12 in the submucous and myenteric plexuses. The distribution of peptide immunoreactivity differed markedly in atresic and normal or sham-operated gut embryos. These differences especially affected the inner structures of the enteric nervous system of specimens proximal to atresia and were related to the severity of dilation. Because nerve structures in the gut wall mucosa and submucous and deep muscular plexuses play a role in motility control and stretch sensation in the intestinal wall, our findings in the chick embryo may help to explain how gut motility disorders develop after surgery for neonatal intestinal atresia. [ABSTRACT FROM AUTHOR]

Guanylin-like peptides regulate electrolyte/water transport through the epithelia. Moreover, these peptides possess antiproliferative activity and regulate the turnover of epithelial cells. In an earlier study we localized guanylin immunoreactivity in secretory ducts of adult rodent salivary glands. In this study we investigated the appearance and distribution pattern of this peptide during the development of rat salivary glands. Guanylin immunoreactivity appeared at the beginning of cell differentiation from solid bud, on embryonic day 17 in the submandibular and sublingual glands and after day 18 in the parotid gland. Guanylin immunoreactivity appeared first in ductal and acinar anlage: its cell distribution pattern and fate differed in these two compartments. In the duct cells guanylin immunoreactivity spread after the duct system developed, whereas in acinar cells it disappeared after cell differentiation. The guanylin immunoreactivity we detected in adult salivary duct cells accords with guanylin’s role in regulating electrolyte and water transport through the various epithelia. It does so by activating guanylate cyclase-C receptor, increasing intracellular cGMP concentration, and phosphorylating the cystic fibrosis transmembrane conductance regulator (CFTR) protein by the cGMP-dependent protein kinase II. This signaling cascade couples to the ductal electrolyte/water secretion and modulates finally the electrolyte composition of the saliva. On the other hand, CFTR is also involved in mechanisms of cell growth, by regulating apoptosis, and promoting cell differentiation. The early diffuse guanylin immunoreactivity we observed in ducts and acinar anlage, before the secretory set is operative, suggests guanylin has a role in cell differentiation. [ABSTRACT FROM AUTHOR]

This paper presents an easy and straightforward routing algorithm for WK-recursive topologies. The algorithm, based on adaptive routing, takes advantage of the geometric properties of such topologies. Once a source node S and destination node D have been determined for a message communication, they characterize, at some level l, two virtual nodes hl_vn(S[sub D]) and hl_vn(D[sub S]) that respectively contain S but not D and D but not S. Such virtual nodes characterize other N[sub d] -- 2 (where N[sub d] is the node degree for a fixed topology) virtual nodes hl_vn (I[sub SD]) of the same level that contain neither S nor D. Consequently, it is possible to locate N[sub d] - 2 triangles whose vertices are these virtual nodes with property to share the same path, called the self-routing path, directly connecting hl_vn(S[sub D]) to hl_vn(D[sub S]). When the self-routing path is unavailable to transmit a message from S to D because of deadlock, fault, and congestion conditions, the routing strategy can follow what we call the triangle rule to deliver it. The proposed communication scheme has the advantage that 1) it is the same for all three conditions; 2) each node of a WK-recursive network, to transmit messages, does not require any information about their presence or location. Furthermore, this routing algorithm is able to tolerate up to [N[sub d](N[sub d] - 3)/2 + 1]N[sup l, sub d] - 1/N[sub d] - 1] faulty links. [ABSTRACT FROM AUTHOR]

From observations in the Republic of Argentina it is concluded that the regular intake of drinking water containing more than 0.1 ppm of arsenic leads to clearly recognizable signs of intoxication and ultimately in some cases to skin cancer [ABSTRACT FROM AUTHOR]

This paper presents a new dataflow graph model, where only data tokens are allowed to flow. First we introduce a High-Level Dataflow System (HLDS) to describe a formal dataflow graph model, then we present a homogeneous HLDS ( hHLDS) that formally describes our proposal. In this proposal the dataflow graph is obtained by employing only actors with homogeneous I/O conditions, that is, each actor, which executes an elemental operation, is characterised by having one output and two input arcs. Even though no control tokens are allowed, i.e. no T-gate, merge, and switch actors are present in this model, it is always possible to obtain dataflow graphs, which represent any programming structure and whose behaviour is well-behaved. As homogeneous I/O conditions are a severe restriction to represent the flow of a computation and the token flow in such dataflow graphs is completely asynchronous, proof is given to guarantee their determinacy. The main advantage of this representation is that it maps directly to hardware through a one-to-one correspondence between actors of the model and Functional Units of a dataflow machine. [ABSTRACT FROM AUTHOR]

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A patient described as a 45,X male (Forabosco et al. 1977) was examined for the presence of Y-specific DNA by using various probes detecting restriction fragments from different regions of the Y chromosome. Positive hybridization signals were obtained for Yp fragments only. In situ hybridization with two different probes, pDP31 and the pseudoautosomal probe 113F, led to a clear assignment of the Yp sequences to the short arm of one chromosome 18. Cytogenetically, the presence of all of Yp including the Y centromere on 18p could be demonstrated replacing a segment of similar size of 18p. Thus, the Y/18 translocation chromosome is dicentric structurally, but it was shown to be monocentric functionally with the no. 18 centromere active. Gene dosage studies with the probe B74 defining a sequence at 18p11.3 demonstrated a single dose of this sequence in the patient. In agreement with these observations, the patient shows clinical signs of the 18p-syndrome. It is concluded that in XO males in general, the X is of maternal origin while the maleness is due to a de novo Y/autosome translocation derived from the father. Depending on the nature of the autosomal deficiency caused by the Y/autosome translocation, the patient may have congenital malformations. [ABSTRACT FROM AUTHOR]