Small bowel intussusception and concurrent jejunal polyp with neoplastic transformation: a new diagnosis of Peutz-Jeghers syndrome.

Peutz-Jeghers syndrome (PJS) is a rare hereditary disease characterised by hyperpigmentation of the oral mucosa and gastrointestinal hamartomatous polyps. We report a case of a 27-year-old man who presented with a 5-day history of epigastric pain and rectal bleeding. Computed tomography suggested small bowel obstruction secondary to ileocolic intussusception and an incidental polyp in the mid jejunum. The patient underwent exploratory laparotomy during which right hemicolectomy and small bowel resection were performed. Histology from surgical specimens revealed Peutz-Jeghers polyps, one of which had low-grade dysplasia. This case emphasises that although rare, adults with PJS can present with intussusception. Also illustrated is the extremely rare possibility of concurrent polyps occurring in different parts of the bowel with neoplastic transformation. Intussusception is a challenge to diagnose because the presentation is often non-specific. Clinical history-taking and physical examination along with prompt axial imaging is important for the diagnosis. Careful examination of the bowel and polypectomy during laparotomy may prevent neoplastic transformation and short bowel syndrome.

Notch1 endocytosis is induced by ligand and is required for signal transduction.

The Notch signalling pathway is widely utilised during embryogenesis in situations where cell-cell interactions are important for cell fate specification and differentiation. DSL ligand endocytosis into the ligand-expressing cell is an important aspect of Notch signalling because it is thought to supply the force needed to separate the Notch heterodimer to initiate signal transduction. A functional role for receptor endocytosis during Notch signal transduction is more controversial. Here we have used live-cell imaging to examine trafficking of the Notch1 receptor in response to ligand binding. Contact with cells expressing ligands induced internalisation and intracellular trafficking of Notch1. Notch1 endocytosis was accompanied by transendocytosis of ligand into the Notch1-expressing signal-receiving cell. Ligand caused Notch1 endocytosis into SARA-positive endosomes in a manner dependent on clathrin and dynamin function. Moreover, inhibition of endocytosis in the receptor-expressing cell impaired ligand-induced Notch1 signalling. Our findings resolve conflicting observations from mammalian and Drosophila studies by demonstrating that ligand-dependent activation of Notch1 signalling requires receptor endocytosis. Endocytosis of Notch1 may provide a force on the ligand:receptor complex that is important for potent signal transduction.

Notch4 reveals a novel mechanism regulating Notch signal transduction.

Notch4 is a divergent member of the Notch family of receptors that is primarily expressed in the vasculature. Its expression implies an important role for Notch4 in the vasculature; however, mice homozygous for the Notch4(d1) knockout allele are viable. Since little is known about the role of Notch4 in the vasculature and how it functions, we further investigated Notch4 in mice and in cultured cells. We found that the Notch4(d1) allele is not null as it expresses a truncated transcript encoding most of the NOTCH4 extracellular domain. In cultured cells, NOTCH4 did not signal in response to ligand. Moreover, NOTCH4 inhibited signalling from the NOTCH1 receptor. This is the first report of cis-inhibition of signalling by another Notch receptor. The NOTCH4 extracellular domain also inhibits NOTCH1 signalling when expressed in cis, raising the possibility that reported Notch4 phenotypes may not be due to loss of NOTCH4 function. To better address the role of NOTCH4 in vivo, we generated a Notch4 null mouse in which the entire coding region was deleted. Notch4 null mice exhibited slightly delayed vessel growth in the retina, consistent with our novel finding that NOTCH4 protein is expressed in the newly formed vasculature. These findings indicate a role of NOTCH4 in fine-tuning the forming vascular plexus.

Prospective study of urine cytology screening for BK polyoma virus replication in renal transplant recipients.

OBJECTIVE: BK virus (BKV) may be associated with interstitial nephritis in renal transplant recipients and this can lead to irreversible chronic allograft dysfunction. Early diagnosis of BKV nephropathy determines its progress because no specific antiviral therapy exists. Urine cytology, detection of viral DNA in urine or blood and renal biopsy are the main diagnostic tools. The purpose of this study was to evaluate the use of urine cytology for diagnosis of BKV replication in renal graft recipients. PATIENTS AND METHODS: We studied 32 de novo renal transplant recipients prospectively with sequential urine samples for a period of 1 year. Thin-Prep methodology was used to prepare the slides. Cytology results were correlated with polymerase chain reaction (PCR) in urine and blood. RESULTS: Decoy cells indicative of BKV infection were detected in 14 (7.3%) of the 190 urine samples derived from 11 recipients. In three cases with positive decoy cells, BK viraemia and viruria were simultaneously identified. In a further three cases, BKV active replication was confirmed in urine by both cytology and PCR. CONCLUSIONS: Urine cytology is an easy and rapid method of detecting decoy cells in cases where renal biopsy is not possible. However, the low incidence of detection of decoy cells in the present study, together with poor correlation with PCR results, questions its sensitivity and specificity in diagnosing BKV reactivation.

Prevalence and distribution of Setaria yehi in southeastern white-tailed deer.

Filarial worms, Setaria yehi, were found in 286 of 1,045 white-tailed deer (Odocoileus virginianus) from 13 of 16 southeastern states. Infections were widespread in the piedmont and coastal plain physiographic provinces, but rarely occurred in deer of the mountains or in southern Florida. Infections were significantly more prevalent among fawn and yearling deer. Infections with S yehi largely accounted for a mild fibrinous peritonitis commonly observed among southeastern deer.

Fascioloides magna infection in white-tailed deer of southeastern United States.

Livers of 4,023 white-tailed deer (Odocoileus virginianus) from 13 southeastern states were examined for flukes; 514 (12.8%) harbored Fascioloides magna. Other species of liver flukes were not found. Forty-two nidi of infection were found, encompassing 56 counties in 9 states. As many as 125 flukes were recovered from a single deer. Although F magna was widely distributed throughout southeastern United States, most enzootic areas were confined to the coastal plain physiographic province. Since deer serve as reservoirs for F magna infections in domestic livestock, it was concluded that every precaution should be exercised to prevent introduction of liver flukes into areas now free of this helminth.

Intestinal nematodes of white-tailed deer in southeastern United States.

The small intestine, large intestine, and cecum of 975 white-tailed deer (Odocoileus virginianus) from 83 localities in 13 southeastern states were examined for nematodes. In order of prevalence, the following parasites were found: Capillaria bovis, Eucyathostomum webbi, Monodontus louisianensis, Nematodirus odocoilei, Oesophagostomum venulosum, Trichuris sp, Cooperia punctata, Trichostrongylus longispicularis, Strongyloides sp, Cooperia oncophora, Cooperia spatulata, Cooperia sp, and Trichostrongylus calcaratus. Over one-half of the deer examined were free of intestinal nematodes, and most infected deer harbored few parasites. Of the most prevalent species, C bovis, N odocoilei, O venulosum, and Trichuris sp were widely distributed, whereas M louisianensis and E webbi were restricted in distribution. Severe pathogenicity was associated with only heavy Strongyloides sp infections in 2 penned deer. The findings of this study suggested that white-tailed deer of the Southeast are insignificant in the epizootiology of important intestinal nematodes of domestic livestock.

Eucyathostomum webbi sp. n. (Strongyloidea: Cloacinidae) from white-tailed deer (Odocoileus virginianus).

The new species is described from white-tailed deer of McIntosh County, Georgia, and Pushmataha County, Oklahoma. Eucyathostomum webbi sp. n. differs from E. longesubulatum (type) in possessing more internal leaf crown elements, unbarbed spiculte tips, variability in the configuration of the dorsal ray of the male bursa, and shorter vagina and ovejectors; from E. copulatum in being much larger and not having males and females permanently united; from E. spinulosum in the origin of the externo-dorsal ray of the male bursa; and from E. dentatum in having more internal leaf crown elements, shorter spicules, a distinct cephalic vesicle, no dorsal gutter, and a pectinated flange posterior to the vulva. Problems in the taxonomy of the genus Eucyathostomum are discussed. Specimens previously identified as E. longesubulatum from southeastern white-tailed deer were reexamined and found to be conspecific with E. webbi.

Parasitism among white-tailed deer and domestic sheep on common range.

Parasitism was studied in white-tailed deer (Odocoileus virginianus) and domestic sheep (Ovis aries) which shared a common range in eastern West Virginia. Of 30 species of internal parasites, 11 were found in deer and 22 in sheep. Five parasites, Sarcocystis sp., Cysticercus tenuicollis, Oesophagostomum venulosum, Cooperia punctata, and Gongylonema pulchrum, occurred in both deer and sheep. An index of similarity of 17.2 suggests that the parasite faunas of these hosts are distinct, and that it is unlikely that white-tailed deer are reservoirs of common parasites of domestic sheep in the southern Appalachian region.

Helminth parasitisms among intermingling insular populations of white-tailed deer, feral cattle, and feral swine.

Helminth infections among free-ranging, intermingling populations of white-tailed deer (Odocoileus virginianus), cattle (Bos taurus), and swine (Sus scrofa) on an island off the Georgia coast were studied. Of 39 species of helminths collected, 19 were found in deer, 17 in cattle, and 13 in swine. Of 28 species of helminths recovered from ruminants, 8, viz, Capillaria bovis, Cooperia punctata, Dictyocaulus viviparus, Gongylonema pulchrum, G verrucosum, Haemonchus contortus, Moniezia benedeni, and Trichostrongylus axei, occurred in both deer and cattle. Common liver flukes (Fasciola hepatica) infected cattle and swine but not deer. Only 1 helminth, G pulchrum, infected deer, cattle, and swine. The findings suggested that helminths harbored by the host species are distinct, with little exchange occurring.