Complete Genome Sequence of Alkaliphilus metalliredigens Strain QYMF, an Alkaliphilic and Metal-Reducing Bacterium Isolated from Borax-Contaminated Leachate Ponds

Alkaliphilus metalliredigens strain QYMF is an anaerobic, alkaliphilic, and metal-reducing bacterium associated with phylum Firmicutes QYMF was isolated from alkaline borax leachate ponds. The genome sequence will help elucidate the role of metal-reducing microorganisms under alkaline environments, a capability that is not commonly observed in metal respiring-microorganisms.

The epidemiology of life-threatening complications associated with reproductive process in public hospitals in Argentina

OBJECTIVE

To analyse life-threatening obstetric complications that occurred in public hospitals in Argentina.

DESIGN

Multicentre collaborative cross-sectional study.

SETTING

Twenty-five hospitals included in the Perinatal Network of Buenos Aires Metropolitan Area.

POPULATION

Women giving birth in participating hospitals during a 1-year period.

METHODS

All cases of severe maternal morbidity (SMM) and maternal mortality (MM) during pregnancy (including miscarriage and induced abortion), labour and puerperium were included. Data were collected prospectively.

MAIN OUTCOME MEASURES

Identification criteria, main causes and incidence of SMM; case-fatality rates, morbidity-mortality index and effective intervention's use rate.

RESULTS

A total of 552 women with life-threatening conditions were identified: 518 with SMM, 34 with MM. Identification criteria for SMM were case-management (48.9%), organ dysfunction (15.2%) and mixed criteria (35.9%). Incidence of SMM was 0.8% (95% confidence interval [95% CI] 0.73-0.87%) and hospital maternal death ratio was 52.3 per 100 000 live births (95% CI 35.5-69.1). Main causes of MM were abortion complications and puerperal sepsis; main causes of SMM were postpartum haemorrhage and hypertension. Overall case-fatality rate was 6.2% (95% CI 4.4-8.6): the highest due to sepsis (14.8%) and abortion complications (13.3%). Morbidity-mortality index was 15:1 (95% CI 7.5-30.8). Use rate of known effective interventions to prevent or treat main causes of MM and SMM was 52.3% (95% CI 46.9-57.7).

CONCLUSIONS

This study describes the importance of life-threatening obstetric complications that took place in public hospitals with comprehensive obstetric care and the low utilisation of known effective interventions that may decrease rates of SMM and MM. It also provides arguments that justify the need to develop a surveillance system for SMM.

Infliximab as rescue therapy in hospitalised patients with steroid-refractory acute ulcerative colitis: a long-term follow-up of 211 Swedish patients

BACKGROUND

Rescue therapy with infliximab (IFX) has been proven effective in a steroid-refractory attack of ulcerative colitis (UC). The long-term efficacy is not well described.

AIM

To present a retrospective study of IFX as rescue therapy in UC. Primary end points were colectomy-free survival at 3 and 12 months.

METHODS

In this multicentre study, 211 adult patients hospitalised between 1999 and 2010 received IFX 5 mg/kg as rescue therapy due to a steroid-refractory, moderate-to-severe attack of UC. Exclusion criteria were duration of current flare for >12 weeks, corticosteroid treatment for >8 weeks before hospitalisation, previous IFX therapy or Crohn's disease.

RESULTS

Probability of colectomy-free survival at 3 months was 0.71 (95% CI, 0.64-0.77), at 12 months 0.64 (95% CI, 0.57-0.70), at 3 years 0.59 (95% CI, 0.52-0.66) and at 5 years 0.53 (95% CI, 0.44-0.61). Steroid-free, clinical remission was achieved in 105/211 (50%) and 112/209 (54%) patients at 3 and 12 months respectively. Of 75 colectomies during the first year, 48 (64%) were carried out during the first 14 days, 13 (17%) on days 15-90 and 14 (19%) between 3 and 12 months. There were three (1.4%) deaths during the first 3 months.

CONCLUSIONS

Infliximab is an effective rescue treatment, both short- and long-term, in a steroid-refractory attack of UC. Most IFX failures underwent surgery during the first 14 days, which calls for studies on how to optimise induction treatment with IFX. Serious complications, including mortality, were rare.

Risk of haematopoietic cancer in patients with inflammatory bowel disease

BACKGROUND AND AIMS

Several chronic inflammatory conditions are associated with an increased risk of lymphoma. Whether this applies to inflammatory bowel disease (IBD) is still unclear but of paramount interest, particularly in the safety evaluation of newer immunosuppressive drugs. Reports also indicate a possible increase in the risk of leukaemia in IBD. We therefore assessed the risk of haematopoietic cancers in a large cohort of patients with IBD.

SUBJECTS AND METHODS

We performed a population based cohort study using prospectively recorded data, including 47 679 Swedish patients with Crohn's disease (CD) or ulcerative colitis (UC) assembled from regional cohorts of IBD from 1955 to 1990 (n = 8028) and from the Inpatient Register of 1964-2000 (n = 45 060), with follow up until 2001. Relative risks were expressed as standardised incidence ratios (SIR).

RESULTS

Overall, we observed 264 haematopoietic cancers during follow up, which corresponded to a borderline significant 20% increased risk in both UC and CD. In UC, lymphomas occurred as expected (SIR 1.0, n = 87) but myeloid leukaemia occurred significantly more often than expected (SIR 1.8, n = 32). In CD, there was a borderline significant increased lymphoma risk (SIR 1.3, n = 65), essentially confined to the first years of follow up. Proxy markers of disease activity had little impact on lymphoma risk.

CONCLUSION

On average, patients with IBD have a marginally increased risk of haematopoietic cancer. In UC, this is accounted for by an excess of myeloid leukaemia. In CD, a modest short term increase in the risk of lymphoma of unknown significance cannot be excluded but any long term risk increase seems unlikely.

Infliximab in inflammatory bowel disease: clinical outcome in a population based cohort from Stockholm County

BACKGROUND

Several placebo controlled studies have demonstrated the efficacy of infliximab in inflammatory bowel disease (IBD) but the potential toxicity of this new biological compound has been less studied.

AIM

To assess the use of infliximab in IBD in a population based cohort, with special emphasis on the occurrence of severe adverse events and mortality.

PATIENTS

All patients with IBD treated with infliximab between 1999 and 2001 in Stockholm County were evaluated.

METHODS

Prospective registration of clinical data was carried out. Retrospective analyses were made of possible adverse events occurring in relation to infliximab treatment. Adverse events requiring pharmacological treatment or hospitalisation were defined as severe. Clinical response was assessed as remission, response, or failure.

RESULTS

A cohort comprising 217 patients was assembled: 191 patients had Crohn's disease (CD), and infliximab was used off label for ulcerative colitis (UC) in 22 patients. Four patients were treated for indeterminate colitis (IC). Mean age was 37.6 (0.9) years (range 8-79). The mean number of infliximab infusions was 2.6 (0.1) (range 1-11). Forty two severe adverse events were registered in 41 patients (CD, n = 35). Eleven of the severe adverse events occurred postoperatively (CD, n = 6). Three patients with CD developed lymphoma (of which two were fatal), opportunistic infections occurred in two patients (one with UC, fatal), and two patients with severe attacks of IBD died due to sepsis (one with CD, one postoperatively with UC). One additional patient with UC died from pulmonary embolism after colectomy. Mean age in the group with fatal outcome was 62.7 years (range 25-79). The overall response rate was 75% and did not differ between the patient groups.

CONCLUSIONS

Infliximab was efficacious as an anti-inflammatory treatment when assessed in a population based cohort of patients with IBD. However, there appear to be a significant risk of deleterious and fatal adverse events, particularly in elderly patients with severe attacks of IBD. Off label use of infliximab in UC and IC should be avoided until efficacy is proven in randomised controlled trials. The underlying risk of developing malignancies among patients with severe or chronically active CD in need of infliximab treatment is not known but the finding of a 1.5% annual incidence of lymphoma emphasises the need for vigilant surveillance with respect to this malignant complication.

Family history as a risk factor for colorectal cancer in inflammatory bowel disease

BACKGROUND & AIMS

Familial colorectal cancer (CRC) is a risk factor for CRC in healthy individuals and, as indicated by case-control studies, possibly in ulcerative colitis. Little is known about the cancer risk in familial inflammatory bowel disease (IBD). We assessed the significance of familial CRC, or IBD, on the risk for CRC in patients with IBD.

METHODS

Population-based cohort study of 19,876 individuals with ulcerative colitis or Crohn's disease born between 1941 and 1995. Registry-based follow-up and assessment of familial CRC, and IBD. Risk of CRC assessed as incidence proportion ("absolute risk," IP) and relative risk (RR).

RESULTS

Familial CRC was associated with a more than 2-fold risk of CRC (adjusted RR = 2.5, 95% confidence interval 1.4-4.4) and an increase in the IP of CRC at 54 years of age from 3.8% to 6.9%. Patients with a first-degree relative diagnosed with CRC before 50 years of age had a higher RR (9.2, 95% confidence interval 3.7-23) and the highest IP (29%). No association with familial IBD was observed.

CONCLUSIONS

Information on family history of CRC may be a simple way to identify individuals with IBD at elevated risk of developing CRC.

Recurrence after colectomy in Crohn's colitis

PURPOSE

Previous studies on recurrence and reoperation after colectomy in Crohn's colitis have been based on heterogeneous groups of patients, and divergent findings may be explained by referral biases and small numbers of patients. The aim of this study was to account for recurrence rates, present risk factors for recurrence after primary colectomy, and account for the ultimate risk of having a stoma after colectomy with ileorectal anastomosis in patients with Crohn's colitis.

METHODS

Data on the primary resection, postoperative recurrence, influence of concomitant risk factors, frequency of stoma operations and proctectomy were evaluated retrospectively using multivariate analysis in a population-based cohort of 833 patients with Crohn's colitis.

RESULTS

The cumulative 10-year risk of a symptomatic recurrence was 58 percent (95 percent confidence interval, 53-63 percent) and 47 percent (95 percent confidence interval, 42-52 percent), respectively, after colectomy with ileorectal anastomosis and segmental colonic resection. In colectomy with ileostomy, lower rates were found with respectively 24 percent (95 percent confidence interval, 18-30 percent) and 37 percent (95 percent confidence interval, 32-43 percent) after subtotal colectomy and proctocolectomy with ileostomy. The multivariate analysis showed that perianal disease, ileorectal anastomosis, and segmental resection were independent risk factors for postoperative recurrence. In 76 percent of patients with ileorectal anastomosis, a stoma-free function could be retained during a median follow-up of 12.5 years.

CONCLUSION

Colectomy with ileorectal anastomosis or segmental resection is a feasible option in the surgical treatment of Crohn's colitis, although anastomoses, in addition to perianal disease, carry an increased risk of recurrent disease.

The changing epidemiology of inflammatory bowel diseases

Epidemiological studies of inflammatory bowel disease are important in order to find possible clues to the still unknown etiology, as well as for the planning of the health service. In supplement to short-term studies, reporting the actual state of the disease, long-term studies are requisited to follow up the development of inflammatory bowel disease. Inflammatory bowel disease has become more frequent during the past decades, with an approximate prevalence of 0.5% in the northern part of the world. A changed disease panorama can be noted with increasing median age at diagnosis, a growing entity of patients with colorectal Crohn's disease and a shift towards more distal ulcerative colitis. The increased age at diagnosis is attributed to a postponement of the age-specific incidence peak. While the difference between gender has levelled off, difference still exists in young adults in Crohn's disease and in elderly in ulcerative colitis. Colorectal cancer has become a matter also in Crohn's disease.

Colorectal cancer rates among first-degree relatives of patients with inflammatory bowel disease: a population-based cohort study

BACKGROUND

Inflammatory bowel disease (IBD) and colorectal cancer might share a common cause and, therefore, relatives of patients with IBD could be at increased risk of this malignant disease. We aimed to assess cancer rates among first-degree relatives of patients with IBD to try to determine whether an association between the two diseases exists.

METHODS

In a population-based study, we identified 114,102 first-degree relatives by registry linkage and followed them up for cancer occurrence. We used standardised incidence ratio (SIR) of cancer as relative risk.

FINDINGS

560 colorectal cancers were identified among relatives. First-degree relatives of patients with Crohn's disease or ulcerative colitis were not at increased risk of cancer (SIR 0.90, 95% CI 0.82-0.97). The relative risk was 0.96 (0.87-1.06, n=379) for colon cancer and 0.78 (0.68-0.91, 181) for rectal cancer. The SIRs were not affected by age, relation to patient, or type or extent of IBD in the patient. Relatives of patients with both IBD and colorectal cancer had an 80% increased risk of colorectal cancer.

INTERPRETATION

Our results do not endorse a common cause of IBD and colorectal cancer. The slightly decreased relative risk for colorectal cancer among relatives could indicate the proportion of all colorectal cancer cases attributable to IBD.

The Rhodobacter capsulatus genome

The genome of Rhodobacter capsulatus has been completely sequenced. It consists of a single chromosome containing 3.5 Mb and a circular plasmid of 134 kb. This effort, started in 1992, began with a fine-structure restriction map of an overlapping set of cosmids that covered the genome. Cosmid sequencing led to a gapped genome that was filled by primer walking on the chromosome and by using lambda clones. Methods had to be developed to handle strong stops in the high GC (68%) inserts. Annotation was done with the ERGO system at Integrated Genomics, as was the reconstruction of the cell's metabolism. It was possible to recognize 3709 orfs of which functional assignments could be made with high confidence to 2392 (65%). Unusual features include the presence of numerous cryptic phage genomes embedded in the chromosome.

Risk factors for surgery and recurrence in 907 patients with primary ileocaecal Crohn's disease

BACKGROUND

Previous studies on risk factors for resection and postoperative recurrence in Crohn's disease have given inconclusive results. The aim of this study was to assess the risk for resection and postoperative recurrence in the treatment of ileocaecal Crohn's disease and to define factors affecting the course of the disease.

METHODS

A population-based cohort of 907 patients with primary ileocaecal Crohn's disease was reviewed retrospectively.

RESULTS

Resection rates were 61, 77 and 83 per cent at 1, 5 and 10 years respectively after the diagnosis. Relapse rates were 28 and 36 per cent 5 and 10 years after the first resection. A younger age at diagnosis resulted in a low resection rate. The presence of perianal Crohn's disease and long resection segments increased the incidence of recurrence, and resection for a palpable mass and/or abscess decreased the recurrence rate. A decrease in recurrence rate during the study period (1955-1989) was observed.

CONCLUSION

In ileocaecal Crohn's disease the probability of resection is high and the risk of recurrence moderate. Crohn's disease in childhood carries a lower risk of primary resection. Perianal disease and extensive ileal resection increase the risk of recurrence.

Risk factors for surgery and postoperative recurrence in Crohn's disease

OBJECTIVE

To assess the impact of possible risk factors on intestinal resection and postoperative recurrence in Crohn's disease (CD) and to evaluate the disease course.

SUMMARY BACKGROUND DATA

The results of previous studies on possible risk factors for surgery and recurrence in Crohn's disease have been inconsistent. Varying findings may be explained by referral biases and small numbers of patients in some studies.

METHODS

Data on initial intestinal resection and postoperative recurrence were evaluated retrospectively in a population-based cohort of 1,936 patients. The influence of concomitant risk factors was assessed using uni- and multivariate analyses.

RESULTS

The cumulative rate of intestinal resection was 44%, 61%, and 71% at 1, 5, and 10 years after diagnosis. Postoperative recurrences occurred in 33% and 44% at 5 and 10 years after resection. The relative risk of surgery was increased in patients with CD involving any part of the small bowel, in those having perianal fistulas, and in those who were 45 to 59 years of age at diagnosis. Female gender and perianal fistulas, as well as small bowel and continuous ileocolonic disease, increase the relative risk of recurrence.

CONCLUSIONS

Three of four patients with CD will undergo an intestinal resection; half of them will ultimately relapse. The extent of disease at diagnosis and the presence of perianal fistulas have an impact on the risk of surgery and the risk of postoperative recurrence. Women run a higher risk of postoperative recurrence than men. The frequency of surgery has decreased over time, but the postoperative relapse rate remains unchanged.

Low molecular weight heparin as adjuvant therapy in active ulcerative colitis

BACKGROUND

Heparin given intravenously has shown beneficial effects in the treatment of refractory ulcerative colitis in open trials. Low molecular weight heparin (LMWH) offers advantages in the method of administration but have not been evaluated in inflammatory bowel disease conditions.

AIM

To assess the tolerability and safety of subcutaneous self-administered LMWH in outpatients with refractory ulcerative colitis and to evaluate any potential adjuvant therapeutic effect.

PATIENTS AND METHODS

Twelve patients with mild to moderately active ulcerative colitis were included in the trial. The patients had either responded poorly to treatment with conventional therapy, including oral and/or rectal glucocorticosteroids, or had experienced a rapid relapse during or shortly after GCS therapy. Dalteparin sodium 5000 units s.c. injection was administered twice daily for 12 weeks. Patients were monitored for possible adverse events and changes in clinical symptoms, and endoscopic and histological scores were analysed. Leucocyte scanning was performed at inclusion and at the end of the study.

RESULTS

Tolerability and compliance were excellent and no serious adverse events occurred. Eleven patients improved symptomatically and six (50%) attained complete remission after 12 weeks of treatment. Endoscopic, scintigraphic and histological scores were found to be significantly improved.

CONCLUSION

Self-administered LMWH given s.c. may be a safe adjuvant therapy for patients with active, glucocorticosteroids-refractory ulcerative colitis. A controlled trial should be undertaken to confirm the positive effects found in this study.

The prevalence of gallstone disease in a defined cohort of patients with Crohn's disease

OBJECTIVE

Crohn's disease (CD) is associated with a high prevalence of gallstone disease but the relative risk has not been completely established. Ileal disease or resection have been considered as contributing factors to the increased risk. The aim of this study was to evaluate the prevalence of gallstone disease in a defined cohort of CD patients, to evaluate possible risk factors, and to evaluate the relative risk compared with the general population.

METHODS

All inhabitants in Stockholm County born in 1933-1935 or 1953-1955, with CD diagnosed between 1955-1989 and not having had a previous cholecystectomy, were invited for an ultrasonography of the gallbladder. The prevalence of gallstone disease was related to disease extent, previous intestinal resections, age, and gender. The relative risk of developing gallstones was calculated using a recent study of gallstone disease in general, with similar age groups as controls.

RESULTS

We found that 26.4% had gallstone disease (relative risk [RR] = 1.8; 95% confidence interval [CI], 1.2-2.7). The number of previous intestinal resections was the only significant risk factor. There was no significant difference in gallstone disease between gender (28.2% vs 24.1%) or age (34% vs 21.8%).

CONCLUSIONS

Patients with Crohn's disease, regardless of gender and age, have almost a doubled risk of developing gallstone disease compared with the general population. Circumstances related to laparotomy may contribute to the increased risk. The lack of association between the disease extent and the site of previous intestinal resection, together with a previous finding of normal cholesterol saturation of the bile in patients with CD, indicate that these patients may develop pigment stones rather than cholesterol stones.

Identification of early apoptosis in feulgen-stained cultured cells in situ by computerized image analysis

A method is presented in which Feulgen-stained apoptotic cells are identified among cultured cells in situ using computerized image analysis of their nuclei. Images of either control (untreated) human lymphoblastoid cell nuclei or of similar cells treated with 3mM methyl methanesulfonate for 1 h, which induces apoptosis in 100% of the cells, were converted to a standard size (80 x 80 pixels) and Fourier transforms and boundary images based on 21 proportional mean gray-level thresholds obtained. The perimeter and the mean fractal dimension of the latter and 39 selected coefficients of the former were then obtained from which data were chosen heuristically and subjected to multivariate linear discrimination analysis. Eighty-two percent of a teaching set of 50 nuclei and 69% of a test set of 29 nuclei were correctly identified as apoptotic versus nonapoptotic by the computer, compared with 57% identified correctly by a panel of 7 pathologists. This study shows the feasibility of using this type of analysis to directly identify apoptotic cells in culture, and probably also in tissues, by direct observation using computerized imaging technology.

Clinical course of colorectal Crohn's disease: a 35-year follow-up study of 507 patients

BACKGROUND & AIMS

Crohn's disease (CD) confined to the colon and rectum is an increasing clinical entity. The aim of this study was to assess the features and clinical course of colorectal CD.

METHODS

This was a retrospective cohort study of 507 patients in whom colonic or rectal CD had been diagnosed between 1955 and 1989.

RESULTS

Colonic distribution was segmental in 40%, total in 31%, and left-sided in 26%. Perianal/rectal fistulas occurred in 37%. In patients who attained clinical remission, the 5-year cumulative relapse rate after diagnosis was 67% (95% confidence interval [CI], 62-72). At the initial presentation of CD, the frequency of major surgery decreased from 24% to 14% (P < 0.005) over time. Still, the overall long-term probability of major surgery after 10 years was unaltered (49% vs. 47%). The presence of fistulas increased the probability of surgical resection (relative risk [RR], 1.7 [95% CI, 1.3-2.2]), whereas left-sided disease was associated with a decrease (RR, 0.6 [95% CI, 0.4-0.8]). Twenty-four percent of the patients developed inflammation in the small bowel. The cumulative risk for a permanent ileostomy was 25% (95% CI, 21-29) 10 years after diagnosis.

CONCLUSIONS

Colorectal CD is an increasing entity carrying substantial morbidity. Half of the patients will undergo surgical resection within the first 10 years, and half of those will ultimately undergo ileostomy. Changed management at diagnosis has not affected the long-term probability of resection.

Bile composition in patients with ileal resection due to Crohn's disease

Patients with Crohn's disease (CD) have an increased risk of developing gallstones, but the mechanisms are unknown. In a previous study, we found a subnormal cholesterol saturation in the bile of patients with short ileal resections due to CD. The aim of this study was to test the hypothesis that (a) CD patients with a long ileal resection have an altered biliary composition and (b) that CD patients with short or long ileal resection have an increased content of bilirubin in their bile. Biliary lipid composition, cholesterol saturation, bile acid pattern, and bilirubin concentration were determined in fasting duodenal bile of 10 CD patients with long ileal resections and in 4 patients with short resections. Ten healthy subjects served as controls. Cholesterol saturation was significantly lower in those CD patients who had a long or short resection compared with the healthy subjects. Bile acid composition in the CD patients was characterized by a significant decrease in the deoxycholic acid fraction and a prominent increase in the ursodeoxycholic acid fraction. The bilirubin concentrations, expressed as micromoles of bilirubin per millimole bile acid, were 45-50% higher in patients who had a long or a short ileal resection compared with healthy controls. Based on these results, CD patients who had had an ileal resection seem not to be at an increased risk of cholesterol gallstone formation but rather at risk of developing pigment stones.

Is there any advantage to the acquisition of 24-hour thallium images, in the presence of persistent perfusion defects at 4 h after reinjection?

We determined the incidence of delayed 24-h reversibility post thallium-201 reinjection and imaging at 4 h, as well as the prognostic and significance of such delayed reversibility. We studied 46 consecutive patients with persistent thallium-201 perfusion or incompletely reversible single-photon emission tomography (SPET) perfusion defects acquired within 10 min after reinjection performed 4 h after stress. In 38 of 46 patients (82%) 24-h images showed no further reversibility beyond the post-reinjection 4-h study (group A). Eight of 46 patients (17%) demonstrated reversibility on 24-h imaging (group B). Of these eight, three patients showed no improvement compared with the post-stress images, with a mean perfusion score of the abnormal segments of 1. 25+/-0.50 on the 4-h images, and of 3.00 on the 24-h images, where normal is 4. Four patients presented with nine mixed regions. Four of these regions showed an improvement in the mean perfusion score of 2.50+/-0.58 on 4- and 24-h images. Two of them, with moderate/severe defects, demonstrated complete reversibility at 4-h post-reinjection imaging. In addition, five other regions presented no improvement at 4-h imaging, but showed an improvement in the mean perfusion score from 0.80+/-0.84 at 4-h to 3.30+/-0.89 at 24-h imaging. Two of these regions in one patient showed a severe perfusion score of 0 at 4 h, and complete reversibility at 24 hours, with a mean score improvement of 4. Another patient had three severe perfusion defects; two of them redistributed partially at 4 h and completely at 24 h. The remaining segment with a perfusion score of 0 at 4 h, presented complete reversibility with a score of 4 at 24 h. Two (4%) patients revealed significant reversibility at 24 h in a region that was severely underperfused after post-reinjection imaging at 4 h. Among group B patients, 75% (6/8) had recent acute ischemic syndrome, compared with only 13% (5/38) in group A (P = 0. 001). Among 11 patients with unstable angina, six (55%) had evidence of delayed 24-h reversibility, compared with 2 of 35 (6%) patients without clinically acute ischemia (P = 0.001). On follow-up, there were seven (17%) cardiac deaths among the 38 group A patients but three (38%) among the eight group B patients (P = 0.3). These findings suggest that although the presence of delayed 24-h 201Tl, post-reinjection reversibility is infrequent, it has potential clinical importance. Thus, delayed 24-h imaging should be considered in the context of unstable angina or other acute coronary syndromes.

Expression of a stress- and starvation-induced dps/pexB-homologous gene is controlled by the alternative sigma factor sigmaB in Bacillus subtilis

SigmaB-dependent general stress proteins (Gsps) of Bacillus subtilis are essential for the development of glucose-starvation-induced cross-resistance to oxidative challenge. However, the proteins directly involved in this nonspecific resistance to oxidative stress have to be identified. We found that one prominent Gsp displayed strong sequence similarity to the previously characterized oxidative-stress-inducible MrgA protein of B. subtilis and to the starvation-induced Dps/PexB protein of Escherichia coli. We therefore designated this prominent Gsp Dps. While MrgA belongs to the peroxide-stress-inducible proteins needed for the H2O2-inducible adaptive response to oxidative stress, Dps belongs to the proteins induced by heat, salt, or ethanol stress and after starvation for glucose but not by a sublethal oxidative challenge. Primer extension experiments identified two overlapping promoters upstream of the coding region of dps, one being sigmaB dependent (PB) and the other being sigmaB independent (P1). Both promoters contribute to the basal level of dps during growth. After stress or during entry into the stationary phase, transcription from PB strongly increased whereas transcription from P1 decreased. Mutant strains lacking Dps completely failed to develop glucose-starvation-induced resistance to oxidative stress. These results confirm our suggestion that sigmaB-dependent general stress proteins of B. subtilis are absolutely required for the development of nonspecific resistance to oxidative stress.

HIV and the dental profession

In order to assess the response of dentists to the increasing incidence of HIV, a study was conducted to explore their attitudes, knowledge and the additional costs involved in treating HIV positive patients. The response of dentists to the increasing incidence of HIV positive patients is influenced by their fears and concerns about HIV, their knowledge about the disease, and their attitudes towards providing care for HIV patients. The results of this research suggest that the negative response to HIV patients from dentists can be attributed to several factors. Dentists are afraid of contracting the virus, they do not trust the honesty of HIV patients, and they believe there are additional costs involved in treating these patients. In order to provide quality dental treatment for HIV patients, dentists must overcome their misperceptions and feelings of anxiety and fear about HIV. Education is a major weapon in the fight against HIV. Dentists agree there is a need for continuing education despite the fact that their overall knowledge about HIV is good.

The complete genome sequence of the gram-positive bacterium Bacillus subtilis

Bacillus subtilis is the best-characterized member of the Gram-positive bacteria. Its genome of 4,214,810 base pairs comprises 4,100 protein-coding genes. Of these protein-coding genes, 53% are represented once, while a quarter of the genome corresponds to several gene families that have been greatly expanded by gene duplication, the largest family containing 77 putative ATP-binding transport proteins. In addition, a large proportion of the genetic capacity is devoted to the utilization of a variety of carbon sources, including many plant-derived molecules. The identification of five signal peptidase genes, as well as several genes for components of the secretion apparatus, is important given the capacity of Bacillus strains to secrete large amounts of industrially important enzymes. Many of the genes are involved in the synthesis of secondary metabolites, including antibiotics, that are more typically associated with Streptomyces species. The genome contains at least ten prophages or remnants of prophages, indicating that bacteriophage infection has played an important evolutionary role in horizontal gene transfer, in particular in the propagation of bacterial pathogenesis.

Incidence of Crohn's disease in Stockholm County 1955-1989

AIM

To evaluate the incidence of Crohn's disease in Stockholm County between 1955 and 1989.

METHODS

A cohort of 1936 patients with Crohn's disease was retrospectively assembled. Incidence rates and changes in disease distribution were assessed.

RESULTS

The mean increase in incidence was 15% (95% confidence intervals 12% to 18%) per five year period with a mean annual incidence rate at 4.6/10(5) during the last two decades. The mean incidence for the entire study period was similar for men and women. The mean age at diagnosis increased from 25 years in 1960-64 to 32 years in 1985-89, partly because of an increasing proportion of patients aged at least 60 years at diagnosis. The proportion of patients with colonic Crohn's disease at the time of diagnosis increased from 15% to 32% (17% difference; 95% confidence intervals 12% to 23%) whereas the proportion of patients with ileocaecal disease decreased from 58% to 41% (17% difference; 95% confidence intervals 10% to 24%) during the study period. Elderly patients had a higher proportion of small bowel disease and a lower proportion of ileocolonic disease compared with the younger patients.

CONCLUSION

The incidence rate of Crohn's disease in Stockholm has stabilised at 4.6/10(5) and the proportion of elderly patients has increased during a 35 year period. Colonic Crohn's disease has increased in frequency with a reciprocal decrease in ileocaecal disease.

A new approach using multiplex long accurate PCR and yeast artificial chromosomes for bacterial chromosome mapping and sequencing

An efficient approach for structural studies on bacterial chromosomes is presented. It is based on high-resolution PCR map construction by using a multiplex long accurate PCR (MLA PCR) protocol and a YAC clone carrying the region to be mapped as indicator. The high-resolution PCR map of the bacillus subtilis rrnB-dnaB region is presented as an example. Data are also presented on the use of DNA generated by LA PCR for sequencing; they are relevant to LA PCR induced mutations and justify the application of such mapping for sequencing long stretches of bacterial chromosomes.

Effects of ileal resection on biliary lipids and bile acid composition in patients with Crohn's disease

Biliary lipid composition, cholesterol saturation, and bile acid pattern were determined in fasting duodenal bile of 10 patients (four men and six women, mean age 41 years) with Crohn's disease and a history of ileal resection (mean 64 cm). The data were compared with corresponding values in a group of healthy subjects. None of the patients with Crohn's disease had supersaturated bile. Cholesterol saturation was significantly lower in the patients with Crohn's disease than in the healthy subjects. The molar percentage of cholesterol was also lower among the patients but there was no significant difference. The molar percentages of phospholipids and bile acids were normal. Bile acid composition in the patients with ileal resection was characterised by a significant decrease in the deoxycholic acid fraction and a pronounced increase in the ursodeoxycholic acid fraction compared with the healthy subjects. The surprisingly high percentage of ursodeoxycholic acid may contribute to the low degree of cholesterol saturation in bile. Based on these results patients with Crohn's disease should not have an increased risk of cholesterol gall stone formation.

A computerized record and verify system for radiation treatments

We have developed a general purpose, comprehensive, and highly reliable computerized Record and Verify System to detect and prevent mistakes in the delivery of external beam radiation therapy. This system helps prevent accidental delivery of dangerous dose, improves quality control, and provides invaluable record keeping and report generating capabilities. Currently, treatment machine and couch parameter settings of four different machines are monitored by the system and compared with prescribed values. The system inhibits a machine from being turned on if the settings do not agree with the prescribed values to within specified maximum permissible deviations. The system is user-friendly and provides useful, complete, and easily accessible data. We describe many aspects of the system including hardware, software, data, and operation, and we conclude with a brief discussion of clinical experience and preliminary data.