Alveolar hydatid disease of the liver: Brief review and spectrum of adjacent organ invasion

The purpose of this study is to show the spectrum of adjacent organ invasion and to make a brief review of hepatic alveolar hydatid disease (AHD), using CT and MR imaging. We retrospectively reviewed CT and MR images of three patients with various adjacent organ invasions surgically and histologically proven to be AHD. Local invasion to right kidney and adrenal, right hemidiaphragm and lung were detected in one patient, right adrenal in another patient and gall bladder, duodenum, gastric wall and pancreas invasion in the other. AHD may rarely extend to the gall bladder, stomach, duodenum, pancreas, right adrenal and kidney, diaphragm, pleura and lung. The extension of the disease outside the liver is usually encountered in patients with large, peripherally located masses in the advanced stage of the disease.     

Deprivation of form vision suppresses diurnal cycling of retinal levels of leu-enkephalin

Deprivation of form vision by the fitting of translucent occluders suppressed the diurnal cycling of enkephalinergic amacrine cells (the ENSLI amacrine cells), in the chicken. Daily periods of normal vision or enforcing temporal contrast using strobe lighting appeared to restore normal functioning of the ENSLI cells. These results suggest that the ENSLI cells are involved in retinal circuits that assess the quality of the visual image and control eye growth.     

Distribution of mutations in the PEX gene in families with X-linked hypophosphataemic rickets (HYP)

Mutations in the PEX gene at Xp22.1 (phosphate-regulating gene with homologies to endopeptidases, on the X-chromosome), are responsible for X-linked hypophosphataemic rickets (HYP). Homology of PEX to the M13 family of Zn2+ metallopeptidases which include neprilysin (NEP) as prototype, has raised important questions regarding PEX function at the molecular level. The aim of this study was to analyse 99 HYP families for PEX gene mutations, and to correlate predicted changes in the protein structure with Zn2+ metallopeptidase gene function. Primers flanking 22 characterised exons were used to amplify DNA by PCR, and SSCP was then used to screen for mutations. Deletions, insertions, nonsense mutations, stop codons and splice mutations occurred in 83% of families screened for in all 22 exons, and 51% of a separate set of families screened in 17 PEX gene exons. Missense mutations in four regions of the gene were informative regarding function, with one mutation in the Zn2+-binding site predicted to alter substrate enzyme interaction and catalysis. Computer analysis of the remaining mutations predicted changes in secondary structure, N-glycosylation, protein phosphorylation and catalytic site molecular structure. The wide range of mutations that align with regions required for protease activity in NEP suggests that PEX also functions as a protease, and may act by processing factor(s) involved in bone mineral metabolism.      

Computed tomography and the prediction of pancreatic abscess in acute pancreatitis.

Pancreatic abscess has become the most common cause of death from acute pancreatitis. Since computed tomography (CT) permits noninvasive imaging of the peripancreatic anatomy, the relationship of early CT findings to late pancreatic sepsis has been evaluated in 83 patients with acute pancreatitis. Pancreatic abscesses developed in 18 patients and were responsible for five of the six deaths in this study. Initial CT findings were graded: A = normal, in 12 patients; B = pancreatic enlargement alone, in 19; C = inflammation confined to pancreas and peripancreatic fat, in 17; D = one peripancreatic fluid collection, in 12; and E = two or more fluid collections, in 23. The incidence of pancreatic abscess in grades A and B was 0%; in grade C, 11.8%; in grade D, 16.7; and in grade E, 60.9%. The severity of pancreatitis was also graded by previously reported prognostic signs as "mild" (0-2 signs) in 56 patients, "moderate" (3-5 signs) in 22, and "severe" (greater than or equal to 6 signs) in five patients. The incidence of abscesses in mild disease was 12.5%; in moderate, 31.8%; and in severe, 80%. Fluid collections on CT resolved spontaneously in 19 of 35 (54.3%) patients. Abscess developed in two patients with no fluid collections on initial CT study. No abscess occurred in 31 patients with CT grades A or B, and in one of 22 patients (4.5%) with CT grade C or D and less than three positive prognostic signs. Among 30 patients with CT grade E or CT grade C or D and three or more positive prognostic signs, 17 (56.7%) developed abscesses. All deaths were in patients with five or more positive prognostic signs. Early imaging of the pancreas by CT identifies a group of patients with increased risk of pancreatic abscess. Identification of this group is improved further by use of early objective prognostic signs.