Bile duct carcinoma in patients with ulcerative colitis

Six cases of bile duct carcinoma were encountered among 1207 patients with ulcerative colitis, a prevalence rate of 0.5%. The relative risk of bile duct carcinoma in patients with ulcerative colitis was 31.3. Colitis was extensive in all six patients with a mean duration of 23.2 years before the diagnosis of carcinoma. The mean age at the diagnosis of carcinoma was 38.5 years. Three patients had undergone colectomy 5–16 years earlier, and in four patients pericholangitis and sclerosing cholangitis preexisted. The tumors, histologically adenocarcinomas, were located in the common bile duct in five patients and in the hepatic duct in one. The mean survival was 11.8 months (one patients is still alive with recurrent carcinoma). Pericholangitis and sclerosing cholangitis is a frequent preexisting lesion in patients with bile duct carcinoma complicating ulcerative colitis and may be considered a premalignant lesion in these patients. Both sclerosing cholangitis and bile duct carcinoma are rare in Crohn's disease.     

Rurality, remoteness and the change process: evidence from a study of maternity services in the north of Scotland.

There is a wealth of material on 'how to do' change plus empirical work revealing change process complexity. In health care, the relevance of context is highlighted, but studies of rural health-care change have focused on community impacts. There is little to inform health-care managers of how remoteness and rurality impact upon change processes. This study considered Scottish maternity units and aimed to identify issues in the change process associated with rurality and remoteness. Six units were purposively selected and 131 interviews were conducted with managers, staff and community members over 15 months. Analysis induced themes pertinent to remoteness and rurality. These included: perceived 'distance' between senior managers imposing change and the wider community of staff and residents; perceptions of community vulnerability; and tensions arising from working in small teams and living in small communities. The study provides useful insights for rural managers at a time of considerable service reconfiguration.     

Chaperonin-mediated assembly of wild-type and mutant subunits of human propionyl-CoA carboxylase expressed in Escherichia coli

We developed a bacterial expression system for the human alpha and beta cDNAs of propionyl-CoA carboxylase (PCC). These cDNAs (less the putative mitochondrial matrix targeting presequences) were co-expressed in Escherichia coli on one plasmid vector with each cDNA having its own IPTG-inducible promoter. Only negligible amounts of active PCC were measured despite the presence of both alpha and beta subunits as indicated by Western blot analysis and the almost complete biotinylation of the alpha subunit. Co-expression of this plasmid with a second plasmid vector over-expressing the E. coli chaperonin proteins, groES and groEL, resulted in a several hundred-fold increase in PCC specific activity, to a level comparable with that found in crude human liver extracts. PCC was partially purified on monomeric avidin affinity resin and the presence of both alpha and beta subunits was demonstrated, thereby confirming the assembly of both subunits into an active enzyme. Deficiency of either alpha PCC or beta PCC results in propionic acidemia, an autosomal recessive disorder. We used this expression system to characterize one missense mutation previously described in five Japanese alleles, namely C1283T (Thr428lle) in beta PCC. This mutation, when expressed in E.coli under the same conditions as that of wild-type PCC, had null activity, despite the presence of assembled alpha PCC and beta PCC subunits. This bacterial expression system can be useful for analysis of either alpha PCC or beta PCC mutations. Our findings indicated that the groES and groEL chaperonin proteins were essential for folding and assembly of the human PCC heteromeric subunits.      

Antigenic variation among Borrelia spp. in relapsing fever.

Seven antigens of Borrelia hermsii, B. parkeri, and B. turicatae with isoelectric points in the range of 4.4 to 5.0 and molecular masses of 40 to 43 kilodaltons played a role in the relapse phenomenon of relapsing fever. Based upon location of the antigens in the outer envelope, the molecular weight, and Western blot analysis, the antigens from each phase of spirochetemia appeared to be a mixture of the serotype-specific antigens of cloned B. hermsii.     

Unusual Enterobacteriaceae: a Salmonella cubana that is Urease Positive

This is the first report of a naturally occurring Salmonella that is urea positive. The strain was identified as Salmonella cubana and it was typical in all biochemical, serological, and bacteriophage reactions, except that is produced urease strongly.     

H7 antiserum-sorbitol fermentation medium: a single tube screening medium for detecting Escherichia coli O157:H7 associated with hemorrhagic colitis.

Escherichia coli serotype O157:H7 has been isolated from outbreaks and sporadic cases of hemorrhagic colitis. There is convincing evidence that it can cause this diarrheal disease. Because of the interest in hemorrhagic colitis, it has become desirable to detect this particular strain in human feces, which usually contains many other strains of E. coli. Two characteristics of the incriminated E. coli O157:H7 strain have made its isolation and identification easier. It does not ferment D-sorbitol rapidly, in contrast to about 95% of other E. coli strains. In addition, the strain has H antigen 7, but only about 10% of other E. coli strains have this particular antigen. To screen for E. coli O157:H7 we devised H7 antiserum-sorbitol fermentation medium (18 g of enteric fermentation base, 10 g of D-sorbitol, 4 g of agar, 10 ml of Andrade indicator, 989 ml of water; all ingredients were mixed, autoclaved, and cooled; 1 ml of E. coli H7 antiserum was then added). Colonies to be screened were inoculated into this medium. Strains of E. coli O157:H7 gave a characteristic pattern; they did not ferment sorbitol and were immobilized in the semisolid medium because of the reaction of their flagella with the flagella antiserum. Almost all other strains of E. coli gave a different pattern; they fermented sorbitol or were not immobilized by the H7 serum or both. Strains which were presumptive positives (sorbitol negative, H7 positive) were then tested in E. coli O157 serum by slide or tube agglutination. The number of strains which were presumptive positive by H7-sorbitol medium but then were not found to be O157 was less than 1%. A second approach has been helpful in deciding which colonies to screen in H7-sorbitol medium. MacConkey-sorbitol agar (22.2 g MacConkey agar base [which contains no sugar], 10 g of D-sorbitol, 1,000 ml of water) was designed as a plating medium. Stools were plated on MacConkey agar to estimate the number of E. coli colonies and also plated on MacConkey-sorbitol agar to estimate the number of sorbitol-negative colonies of E. coli. These two approaches have proved useful for isolating and identifying E. coli O157:H7 form human feces and from feces of animals infected in the laboratory with this strain. The results suggest that media may be formulated in a similar fashion for detecting other specific strains of E. coli.     

Identification of Proteus penneri sp. nov., formerly known as Proteus vulgaris indole negative or as Proteus vulgaris biogroup 1.

The name Proteus penneri sp. nov. is proposed for a group of organisms previously called Proteus vulgaris indole negative or P. vulgaris biogroup 1. All of these strains were salicin negative, esculin negative, and chloramphenicol resistant (zone size, less than 14 mm). DNA relatedness studies indicated that when DNA from P. penneri strain 1808-73 was labeled and tested against unlabeled DNA from 13 other P penneri strains, a highly related group was formed (88 to 99% relatedness at 60 degrees C and 67 to 99% relatedness at 75 degrees C). Strain 1808-73 (ATCC 33519) is proposed as the type strain of P. penneri. In this study, two distinct groups of indole-positive P. vulgaris strains were also apparent. The first group (defined as P. vulgaris biogroup 2) was indole positive, salicin positive, and esculin positive, and the second group (defined as P. vulgaris biogroup 3) was indole positive, salicin negative, and esculin negative. The current type strain of P. vulgaris (ATCC 13315) belongs to biogroup 3. The DNA from P. penneri strains was not highly related to labeled DNA from the type strain of P. vulgaris (14 to 30% relatedness at 75 degrees C) or from P. vulgaris strain PR 1 (ATCC 29905), which belongs to biogroup 2 (27 to 33% relatedness at 75 degrees C). Strains of biogroup 2 were sensitive to chloramphenicol (zone size, greater than 19mm), and 10 of these strains formed a highly related group by DNA hybridization when DNA from PR 1 was labeled (64 to 100% relatedness at 60 degrees C and 70 to 100% relatedness at 75 degrees C), but they were not highly relatedness to the type strain of P. vulgaris (51 to 68% relatedness at 60 degrees C and 14 to 44% relatedness at 75 degrees C). Further DNA relatedness studies are needed on strains of biogroup 3 before a definitive taxonomic proposal can be made for these two indole-positive biogroups.