Exploring dairy producer and veterinarian perceptions of barriers and motivators to adopting on-farm management practices for Johne's disease control in Ontario, Canada.

Motivating uptake of management change recommendations requires knowledge of the barriers and motivators influencing producer behavior. This study investigated dairy producers' and veterinarians' perceptions of the barriers and motivators influencing the adoption of Johne's disease (JD) control recommendations in Ontario, Canada. Eight focus groups, 6 with dairy producers and 2 with veterinarians, were conducted and thematically analyzed. Both producer and veterinarian groups identified physical resources (i.e., time, money, infrastructure) and producer mindset (i.e., perceived priority of JD, perceived practicality of JD control recommendations) as key barriers to adoption. Producers tended to prioritize JD control on their farm based on their lived experiences with JD and their view of the public's concern about JD. Many agreed that JD recommendations should focus on biosecurity more holistically and emphasize the broader health benefits of limiting calf exposure to many fecal-orally transmitted diseases. Producers also highlighted that some recommendations for on-farm change (i.e., keeping a closed herd, buying from low-risk herds) were unrealistic or too difficult to perform and often disrupted their habits or routine. In contrast, veterinarians suggested that most recommendations were practical and are routinely recommended. Participants suggested both extrinsic (i.e., incentives, premiums, penalties and regulations, and extension and communication) and intrinsic (i.e., pride and responsibility) methods for motivating producers. This study highlights the importance of producer mindset in on-farm change and offers insights into the attitudes and perceived barriers influencing on-farm change.

Group B streptococcal PCR testing in comparison to culture for diagnosis of late onset bacteraemia and meningitis in infants aged 7-90 days: a multi-centre diagnostic accuracy study.

The aim of this study was to compare an in-house real-time PCR assay, with bacterial culture as the reference, for the diagnosis of late onset group B Streptococcal (GBS) disease. This was a retrospective review. All children aged 7-90 days presenting to four paediatric centres that had a blood or CSF sample tested by GBS PCR were included. Of 7,686 blood and 2,495 cerebrospinal fluid (CSF) samples from patients of all ages received for PCR testing, 893 and 859 samples were eligible for the study, respectively. When compared to culture, the sensitivity of blood PCR was 65% (13/20) in comparison to the CSF PCR test which was 100% (5/5). Ten of 23 PCR-positive blood samples and 17 of 22 PCR-positive CSF samples were culture negative. The median threshold Ct values for culture-positive/PCR-positive CSF samples was lower than that of culture-negative/PCR-positive CSF samples (p = 0.08). Clinical details of 17 available cases that were culture negative/PCR positive were reviewed; seven were deemed to be definite cases, eight were probable and two were possible. The results showed that detection of GBS by PCR is useful for CSF samples from infants aged 7-90 days with suspected meningitis; however, analysis of blood samples by PCR is of limited value as a routine screening test for late onset GBS sepsis and should not replace bacterial culture.

Real-time polymerase chain reaction and culture in the diagnosis of invasive group B streptococcal disease in infants: a retrospective study.

Group B streptococcus (GBS) is a leading cause of invasive disease in infants. Accurate and rapid diagnosis is crucial to reduce morbidity and mortality. Real-time polymerase chain reaction (PCR) targeting the dltR gene was utilised for the direct detection of GBS DNA in blood and cerebrospinal fluid (CSF) from infants at an Irish maternity hospital. A retrospective review of laboratory and patient records during the period 2011-2013 was performed in order to evaluate PCR and culture for the diagnosis of invasive GBS disease. A total of 3570 blood and 189 CSF samples from 3510 infants had corresponding culture and PCR results. Culture and PCR exhibited concordance in 3526 GBS-negative samples and 13 (25%) GBS-positive samples (n = 53). Six (11%) and 34 (64%) GBS-positive samples were positive only in culture or PCR, respectively. Culture and PCR identified more GBS-positive infants (n = 47) than PCR (n = 43) or culture (n = 16) alone. Using culture as the reference standard, the sensitivity, specificity, and positive and negative predictive values for PCR on blood samples were 71.4%, 99.2%, 25% and 99.9%, and for CSF samples, they were 60%, 97.8%, 42.9% and 98.9%, respectively. The sensitivity and positive predictive values were improved (blood: 84.6% and 55%; CSF: 77.8% and 100%, respectively) when maternal risk factors and other laboratory test results were considered. The findings in this study recommend the use of direct GBS real-time PCR for the diagnosis of GBS infection in infants with a clinical suspicion of invasive disease and as a complement to culture, but should be interpreted in the light of other laboratory and clinical findings.

Evaluating the effect of Focus Farms on Ontario dairy producers' knowledge, attitudes, and behavior toward control of Johne's disease.

This study evaluated a participatory-based, experiential learning program, Ontario Focus Farms (FF), which aimed to change dairy producer behavior to control Johne's disease (JD) in Ontario, Canada. The goals were to (1) assess the effect of FF on participating dairy producers' knowledge, attitudes, and behavior with regard to JD control; (2) compare changes in these factors among FF participants to changes among a group of nonparticipating dairy producers; and (3) describe the characteristics of producers who made at least one on-farm management change. Pre- and post-FF intervention questionnaires collected data on respondents' knowledge, attitudes, behavior, herd production, and demographic information; before and after JD-risk assessments were used to assess respondents' on-farm risk of JD transmission. Overall, 176 dairy producers participated in the FF process; 39.8% (70/176) of FF and 14.6% (52/357) of control participants responded to both the pre- and postintervention questionnaires. Upon comparison, FF respondents were more likely to be younger, have larger herds, and have higher management scores. The proportion of FF participants who reported making at least one on-farm change (81%) was significantly higher than that of control respondents (38%). Overall, FF respondents significantly changed their risk score in 4 out of 5 risk areas and had an average reduction of 13 points in their overall risk score between before and after risk assessments. Control respondents' risk assessment scores did not significantly change during the study period. In a JD knowledge assessment, FF and control respondents exhibited a moderate knowledge score before the intervention period, with median scores of 75.9% (22/29) in each group. The FF respondents significantly increased their score at the postintervention assessment, with a median of 82.8% (24/29); control-respondent scores did not significantly change. Both FF and control respondents held strong positive attitudes toward JD control and felt a moderate amount of social pressure from veterinarians and industry organizations to make on-farm changes. However, they questioned their ability to effectively control JD on the farm. Last, participating in FF, having a moderate herd management score, having a positive perception about the practicality of on-farm recommendations, and having a singular learning preference were associated with increased odds of making an on-farm change. Overall, the FF process appears to be effective at influencing producer behavior toward implementing on-farm management practices for JD control. Future JD control programs should consider implementing peer-learning extension processes, such as FF, in combination with other extension approaches, to influence producer behavior.

Increased incidence of invasive group A streptococcal disease in Ireland, 2012 to 2013.

Invasive group A streptococcal (iGAS) infections have been notifiable in Ireland since 2004. Incidence rates (2004-2011) have ranged from 0.8 to 1.65 per 100,000. In 2012, the iGAS rate rose to 2.66 per 100,000 and was associated with a high proportion of emm1 isolates. A further increase in January to June 2013 has been associated with increased prevalence of emm3. Public health departments and clinicians have been alerted to this increase.

MicroRNA-204 increases sensitivity of neuroblastoma cells to cisplatin and is associated with a favourable clinical outcome.

BACKGROUND: Neuroblastoma remains a major cause of cancer-linked mortality in children. miR-204 has been used in microRNA expression signatures predictive of neuroblastoma patient survival. The aim of this study was to explore the independent association of miR-204 with survival in a neuroblastoma cohort, and to investigate the phenotypic effects mediated by miR-204 expression in neuroblastoma. METHODS: Neuroblastoma cell lines were transiently transfected with miR-204 mimics and assessed for cell viability using MTS assays. Apoptosis levels in cell lines were evaluated by FACS analysis of Annexin V-/propidium iodide-stained cells transfected with miR-204 mimics and treated with chemotherapy drug or vehicle control. Potential targets of miR-204 were validated using luciferase reporter assays. RESULTS: miR-204 expression in primary neuroblastoma tumours was predictive of patient event-free and overall survival, independent of established known risk factors. Ectopic miR-204 expression significantly increased sensitivity to cisplatin and etoposide in vitro. miR-204 direct targeting of the 3' UTR of BCL2 and NTRK2 (TrkB) was confirmed. CONCLUSION: miR-204 is a novel predictor of outcome in neuroblastoma, functioning, at least in part, through increasing sensitivity to cisplatin by direct targeting and downregulation of anti-apoptotic BCL2. miR-204 also targets full-length NTRK2, a potent oncogene involved with chemotherapy drug resistance in neuroblastoma.

Validation of an algorithm to identify incident interstitial lung disease in patients with rheumatoid arthritis.

BACKGROUND/PURPOSE: Interstitial lung disease (ILD) is an important problem for patients with rheumatoid arthritis (RA). However, current approaches to ILD case finding in real-world data have been evaluated only in limited settings and identify only prevalent ILD and not new-onset disease. Our objective was to develop, refine, and validate a claims-based algorithm to identify both prevalent and incident ILD in RA patients compared to the gold standard of medical record review. METHODS: We used administrative claims data 2006-2015 from Medicare to derive a cohort of RA patients. We then identified suspected ILD using variations of ILD algorithms to classify both prevalent and incident ILD based on features of the data that included hospitalization vs. outpatient setting, physician specialty, pulmonary-related diagnosis codes, and exclusions for potentially mimicking pulmonary conditions. Positive predictive values (PPV) of several ILD algorithm variants for both prevalent and incident ILD were evaluated. RESULTS: We identified 234 linkable RA patients with sufficient data to evaluate for ILD. Overall, 108 (46.2%) of suspected cases were confirmed as ILD. Most cases (64%) were diagnosed in the outpatient setting. The best performing algorithm for prevalent ILD had a PPV of 77% (95% CI 67-84%) and for incident ILD was 96% (95% CI 85-100%). CONCLUSION: Case finding in administrative data for both prevalent and incident interstitial lung disease in RA patients is feasible and has reasonable accuracy to support population-based research and real-world evidence generation.

Survey of Equine Referring Veterinarians' Satisfaction with Their Most Recent Equine Referral Experience.

BACKGROUND: Little is known about the veterinary referral process and factors that contribute to positive outcomes. OBJECTIVE: To investigate equine referring veterinarians' (rDVMs') satisfaction with their most recent referral experience and compare rDVM and specialist perspectives. SAMPLE: 187 rDVMs and 92 specialists (referral care providers). METHODS: Cross-sectional observational study. An online survey was administered to both rDVMs and specialists. Referring veterinarian satisfaction with their most recent referral experience was evaluated. Both rDVMs and specialists were asked to identify factors influencing a rDVM's decision where to refer, and the top 3 factors they perceive are barriers to referral care. RESULTS: Median rDVM satisfaction with their most recent referral care experience was 80 of 100 (mean, 75; range, 8-100). Referring veterinarians provided the lowest satisfaction score for the item asking about "The competition the referral hospital poses to your practice" (mean, 56.96; median, 62; range, 0-100). The top factor rDVMs identified as influencing their decision where to refer was "quality of care," whereas specialists identified "quality of communication and updates from the clinician." Referring veterinarians' top barrier to referral care was "high cost of referral care," and for specialists was "poor service provided to the client by the referral hospital." CONCLUSIONS AND CLINICAL IMPORTANCE: Referring veterinarians generally were satisfied with referral care, but areas exist where rDVMs and specialists differ in what they view as important to the referral process. Exploring opportunities to overcome these differences is likely to support high quality care.

Randomized trial comparing epirubicin, cisplatin, and fluorouracil versus fluorouracil, doxorubicin, and methotrexate in advanced esophagogastric cancer.

PURPOSE: We report the results of a prospectively randomized study that compared the combination of epirubicin, cisplatin, and protracted venous infusion fluorouracil (5-FU) (ECF regimen) with the standard combination of 5-FU, doxorubicin, and methotrexate (FAMTX) in previously untreated patients with advanced esophagogastric cancer. PATIENTS AND METHODS: Two hundred seventy-four patients with adenocarcinoma or undifferentiated carcinoma were randomized and analyzed for survival, tumor response, toxicity, and quality of life (QL). RESULTS: The overall response rate was 45% (95% confidence interval [CI], 36% to 54%) with ECF and 21% (95% CI, 13% to 29%) with FAMTX (P = .0002). Toxicity was tolerable and there were only three toxic deaths. The FAMTX regimen caused more hematologic toxicity and serious infections, but ECF caused more emesis and alopecia. The median survival duration was 8.9 months with ECF and 5.7 months with FAMTX (P = .0009); at 1 year, 36% (95% CI, 27% to 45%) of ECF and 21% (95% CI, 14% to 29%) of FAMTX patients were alive. The median failure-free survival duration was 7.4 months with ECF and 3.4 months with FAMTX (P = .00006). The global QL scores were better for ECF at 24 weeks, but the remaining QL data showed no differences between either arm of the study. Hospital-based cost analysis on a subset of patients was similar for each arm and translated into an increment cost of $975 per life-year gained. CONCLUSION: The ECF regimen results in a survival and response advantage, tolerable toxicity, better QL and cost-effectiveness compared with FAMTX chemotherapy. This regimen should now be considered the standard treatment for advanced esophagogastric cancer.

Male circumcision and HIV acquisition and transmission: cohort studies in Rakai, Uganda. Rakai Project Team.

BACKGROUND: Male circumcision is associated with reduced HIV acquisition. METHODS: HIV acquisition was determined in a cohort of 5507 HIV-negative Ugandan men, and in 187 HIV-negative men in discordant relationships. Transmission was determined in 223 HIV-positive men with HIV-negative partners. HIV incidence per 100 person years (py) and adjusted rate ratios (RR) and 95% confidence intervals (CI) were estimated by Poisson regression. HIV-1 serum viral load was determined for the seropositive partners in HIV-discordant couples. RESULTS: The prevalence of circumcision was 16.5% for all men; 99.1% in Muslims and 3.7% in non-Muslims. Circumcision was significantly associated with reduced HIV acquisition in the cohort as a whole (RR 0.53, CI 0.33-0.87), but not among non-Muslim men. Prepubertal circumcision significantly reduced HIV acquisition (RR 0.49, CI 0.26-0.82), but postpubertal circumcision did not. In discordant couples with HIV-negative men, no serconversions occurred in 50 circumcised men, whereas HIV acquisition was 16.7 per 100 py in uncircumcised men (P = 0.004). In couples with HIV-positive men, HIV transmission was significantly reduced in circumcised men with HIV viral loads less than 50000 copies/ml (P = 0.02). INTERPRETATION: Prepubertal circumcision may reduce male HIV acquisition in a general population, but the protective effects are confounded by cultural and behavioral factors in Muslims. In discordant couples, circumcision reduces HIV acquisition and transmission. The assessment of circumcision for HIV prevention is complex and requires randomized trials.

Mortality associated with HIV infection in rural Rakai District, Uganda.

OBJECTIVE: To assess mortality impact of HIV in rural Uganda. METHODS: An open cohort of 19983 adults aged 15-59 years, in Rakai district was followed at 10 month intervals for four surveys. Sociodemographic characteristics and symptomatology/disease conditions were assessed by interview. Deaths among residents and out-migrants were identified household census. Mortality rates were computed per 1000 person years (py) and the rate ratio (RR) of death in HIV-positive/HIV-negative subjects, and the population attributable fraction (PAF) of death were estimated according to sociodemographic characteristics. Mortality associated with potential AIDS defining symptoms and signs was assessed. RESULTS: HIV prevalence was 16.1%. Mortality was 132.6 per 1000 py in HIV-infected versus 6.7 per 1000 py in uninfected subjects, and 73.5% of adult deaths were attributable to HIV infection. Mortality increased with age, but the highest attributable risk of HIV associated deaths were observed in persons aged 20-39 years (PAF > 80%) and in women. HIV associated mortality was highest in the better educated (PAF > or = 75%) and among government employees (PAF > or = 82%). Of the HIV-positive subjects 40.5% reported no illness < 10 months preceding death, symptoms were poor predictors of death (sensitivity 1.6-38.8%), and only 9.1% met the World Health Organization clinical definition of AIDS. Infant mortality rates in babies of HIV-infected and uninfected mothers were 209.4 and 97.7 per 1000, respectively. CONCLUSION: HIV is taking substantial toll in this population, particularly among the younger better educated adults, and infants. Symptomatology or the World Health Organization definition of AIDS are poor predictors of death.

Relative risks and population attributable fraction of incident HIV associated with symptoms of sexually transmitted diseases and treatable symptomatic sexually transmitted diseases in Rakai District, Uganda. Rakai Project Team.

OBJECTIVES: To assess the linkage of sexually transmitted disease (STD) symptoms and treatable STD to HIV incidence. DESIGN: Analysis of a randomized trial of STD control for HIV prevention, Rakai, Uganda. METHODS: Consenting adults 15-59 years of age were seen at 10-monthly home visits, interviewed regarding STD symptoms, and asked to provide samples for HIV and STD diagnoses. HIV incidence was determined in 8089 HIV-negative subjects over 10 457 person years. Adjusted rate ratios (RR) and 95% confidence intervals (CI) of HIV acquisition associated with genital ulcer disease (GUD) and discharge/dysuria were used to estimate the population attributable fraction (PAF) of HIV acquisition. HIV transmission risks associated with STD symptoms in HIV-positive partners of 167 HIV discordant couples and the numbers of sexual partners reported by HIV-positive subjects were used to estimate the PAF of HIV transmission attributable to STD. RESULTS: HIV prevalence was 16%. The risk of HIV acquisition was increased with GUD (RR 3.14; CI 1.98-4.98) and in males with discharge/dysuria (RR 2.44; CI 1.17-5.12), but not in females with discharge/dysuria. The PAF of HIV acquisition was 9.5% (CI 2.8-15.8%) with any of the three STD symptoms. The PAF for GUD was 8.8% (CI 3.7-13.8), but only 8.2% of reported GUD was caused by treatable syphilis or chancroid . The PAF for discharge/dysuria in males was 6.7% (CI 1.1-13.8), but only 25% of symptomatic males had concurrent gonorrhea or chlamydial infection. No significant differences were seen in PAF between study treatment arms. The PAF of HIV transmission associated with STD symptoms in HIV-positive persons was indirectly estimated to be 10.4%. CONCLUSION: In this mature, generalized HIV epidemic setting, most HIV seroconversion occurs without recognized STD symptoms or curable STD detected by screening. Therefore, syndromic management or other strategies of STD treatment are unlikely to substantially reduce HIV incidence in this population. However, STD is associated with significant HIV risk at the individual level, and STD management is needed to protect individuals.

Antigen 43, a phase-variable bipartite outer membrane protein, determines colony morphology and autoaggregation in Escherichia coli K-12.

The product controlling colony form variation and autoaggregation in Escherichia coli K-12 (the flu gene product) has been identified as the phase-variable, bipartite, outer membrane protein, termed antigen 43 (Ag43). Identification is based: (i) on complete correlation in authentic flu variants between colony morphology/autoaggregation and Ag43 expression as determined by colony and Western immunoblotting and immunofluorescence microscopy; and (ii) on the use of a specific probe to map the gene encoding Ag43 to a position (min 43) on the E. coli chromosome previously established for flu.

Neither the A- nor B-repeat regions of the fibrinogen-binding protein of Streptococcus equi subsp. equi are essential for fibrinogen binding.

The major cell wall-associated protein (FgBP) of Streptococcus equi subsp. equi possesses two internal blocks of repeated sequence (A and B) and binds horse fibrinogen (Fg) avidly through residues located in the N-terminal half of the molecule. In the present study, we investigated the roles of the two repeats blocks in Fg binding through construction of recombinant FgBP proteins containing defined internal deletions of sequence. Ligand binding experiments clearly showed that neither repeat is essential for Fg binding. However, residues within the B repeats seem to play a major role in the aberrant mobility observed for FgBP following sodium dodecyl sulfate polyacrylamide gel electrophoresis.

Evaluation of distant metastases in esophageal cancer: 100 consecutive positron emission tomography scans.

BACKGROUND: Pilot studies suggest positron emission tomography (PET) scanning may be superior to conventional imaging in staging esophageal cancer, especially in the detection of radiographically occult distant metastases. This report summarizes our experience with PET in staging esophageal cancer. METHODS: One hundred consecutive PET scans in 91 patients with esophageal cancer referred for surgery were prospectively collected (1995 to 1998) and compared with computerized tomography (CT) and bone scan. PET images were acquired after injection of 18F-fluorodeoxyglucose and evaluated for abnormal uptake. Minimally invasive surgical staging (MIS) and/or clinical correlation were used to confirm or refute imaging results. RESULTS: MIS or clinical correlation confirmed 70 distant metastases in 39 cases. PET detected 51 metastases in 27 of 39 cases (69% sensitivity, 93.4% specificity, 84% accuracy) compared with CT, which detected 26 metastases in 18 of 39 cases (46.1% sensitivity, 73.8% specificity, 63% accuracy) (p < 0.01). CONCLUSIONS: PET was more accurate than CT in detecting distant metastases, but was only 69% sensitive compared with minimally invasive staging.

Phase-variable outer membrane proteins in Escherichia coli.

Escherichia coli contains at least two phase-variable proteins in its outer membrane. One, termed antigen 43 (Ag43), is the product of the metastable flu gene located at min 43.6 on the E. coli chromosome and is responsible for colony form variation and for autoaggregation in liquid media. Ag43 is composed of two proteinaceous subunits, alpha 43 and beta 43 in 1:1 stoichiometry. alpha 43 (apparent M(r) 60,000) is surface expressed, extends beyond the O-side chains of smooth lipopolysaccharide and is bound to the cell surface through an interaction with beta 43 (apparent M(r) 53,000), itself an integral, heat-modifiable, outer membrane protein. alpha 43 shows limited N-terminal sequence homology with certain enterobacterial adhesins, and notable sequence homology with AIDA-1, an adhesin of diffuse-adhering E. coli. In addition, alpha 43 contains an RGD motif and a consensus sequence for an (autoproteolytic?) aspartyl protease active site. Expression of Ag43 is subject to reversible phase variation-in liquid minimal medium, the rates of variation from Ag43+ to Ag43- states and from Ag43- to Ag43+ states being approximately 2.2 x 10(-3) and approximately 1 x 10(-3), respectively. Phase switching of Ag43 is regulated by DNA methylation (deoxyadenosine methylase (dam) mutants being 'locked OFF') and by OxyR (oxyR mutants being 'locked ON'). It is proposed that OxyR acts as a repressor of Ag43 transcription by binding to unmethylated GATC sites in the regulatory region of the gene. In some strains, Ag43 may also undergo antigenic variation. A 94 kDa immunocrossreactive outer membrane protein, showing similar rates of phase variation, has additionally been detected for some enteropathogenic and uropathogenic strains of E. coli. This 94 kDa protein can be proteolytically cleaved in situ with trypsin to yield two membrane-bound products with M(r)s and properties similar to those of alpha 43 and beta 43. Results suggest that Ag43 may represent one of a family of antigenically-related high-M(r) adhesins which are synthesized as polyprotein precursors. Some members may be processed and presented on the cell surface as bipartite protein complexes (as Ag43). Others can remain uncleaved.

Total videothoracoscopic lobectomy versus open thoracotomy for early-stage non small-cell lung cancer.

Lobectomy remains the standard procedure for early-stage non small-cell lung cancer (NSCLC). Advances in minimally invasive surgery allow lobectomy to be performed by videothoracoscopy (VATSLOBE). The objective of this study was to compare open thoracotomy (OPENLOBE) to VATSLOBE in the treatment of early-stage NSCLC. A retrospective review over a 6-year period at a single tertiary care center identified 31 patients treated by VATSLOBE. A comparison was made with 31 patients undergoing OPENLOBE during the same time period. The cases were matched for age, pulmonary function testing, tumor size, and comorbidities. The VATSLOBE technique was carried out using four 1 cm thoracoports, one of which was enlarged to a 4-6 cm access incision for lobe retrieval. OPENLOBE was performed by standard posterolateral thoracotomy. The VATSLOBE group had a longer operative time (214.03 min) compared to OPENLOBE (140.67 min). There was no difference in the extent of lymph node dissection or in morbidity between the two groups. VATSLOBE patients had their chest tubes removed earlier (4.77 vs. 8.16 days) and stayed in the hospital for a shorter time (7.07 vs. 11.94 days) compared to OPENLOBE patients. In this retrospective review, lobectomy performed by the videothoracoscopic approach was comparable to OPENLOBE in terms of lymph node dissection, morbidity, and long-term survival. VATSLOBE had the advantages of a shorter hospital stay and fewer days with a chest tube. Minimally invasive surgery for early-stage lung cancer should be further investigated in multi-institutional controlled trials.

A novel regulatory mechanism for a novel phase-variable outer membrane protein of Escherichia coli.

Antigen 43 (Ag43) is a prominent hetero-oligomeric protein complex in the outer membrane of Escherichia coli. It is composed of two subunits. alpha 43 (M(r) 60, 000) and beta 43 (M(r) 53, 000) in 1:1 stoichiometry. alpha 43 is surface expressed, extends beyond the O-side chains of smooth lipopolysaccharide and is bound to the cell surface through an interaction with beta 43, itself an integral outer membrane protein, alpha 43 shows limited sequence homology with some enterobacterial adhesins. Expression of Ag43 is subject to reversible phase variation, the rates of variation from the Ag43+ve to Ag43-ve states in liquid minimal medium being approximately 2.2 x 10(-3), the corresponding rates from Ag43-ve to Ag43+ve states being approximately 1 x 10(-3). Phase switching of genes encoding Ag43 are transcriptionally regulated by DNA methylation (deoxyadenosine methylase [dam] mutants being "locked OFF") and by OxyR (oxyR mutants being "locked ON"). It is proposed that OxyR acts as a repressor of Ag43 transcription by binding to unmethylated GATC sites in the regulatory region of the gene. Sequencing and mapping has identified Ag43 as the likely product of the metastable flu gene first described in 1980 by Diderichsen and responsible for colony form variation in E. coli.

Whole-body FDG positron emission tomographic imaging for staging esophageal cancer comparison with computed tomography.

PURPOSE: The aim of the authors in this study was to critically evaluate the role of whole-body positron emission tomographic (PET) imaging with fluorine-18 fluorodeoxyglucose (FDG) in staging esophageal cancer, and further to compare this method with conventional imaging with computed tomography (CT). MATERIALS AND METHODS: The authors performed independent, blinded retrospective evaluations of FDG PET images obtained in 47 patients referred for the initial staging of esophageal cancer before minimally invasive surgical staging. Twenty PET studies from patients with nonesophageal thoracic cancers were randomly selected for inclusion in the PET readings. In a subset of 37 of 47 cases, the PET findings were compared with independent readings of CT studies acquired within the same 6-week interval. The utility of the imaging findings was evaluated using a high-sensitivity interpretation (i.e., assigning equivocal findings as positive) and a low-sensitivity interpretation (i.e., assigning equivocal findings as negative). RESULTS: PET was less sensitive (41% in high-sensitivity mode, 35% in low-sensitivity mode) than CT (63% to 87%) for diagnosing tumor involvement in locoregional lymph nodes, which was identified by surgical assessment in 72% of patients. Notable, however, was the greater specificity of PET-determined nodal sites (to approximately 90%) compared with CT (14% to 43%). In detecting histologically proved distant metastases (n = 10), PET performed considerably better when applied in the high-sensitivity mode, with a sensitivity rate of approximately 70% and a specificity rate of more than 90% in the total group and in the subset of patients with correlative CT data. In the low-sensitivity mode, CT identified only two of seven metastatic sites, whereas the high-sensitivity mode resulted in an unacceptably high rate of false-positive readings (positive predictive value, 29%). PET correctly identified one additional site of metastasis that was not detected by CT. CONCLUSIONS: The relatively low sensitivity of PET for identifying locoregional lesions precludes its replacement of conventional CT staging. However, the primary advantage of PET imaging is its superior specificity for tumor detection and improved diagnostic value for distant metastatic sites, features that may substantially affect patient management decisions. In conclusion, PET imaging is useful in the initial staging of esophageal cancer and provides additional and complementary information to that obtained by CT imaging.

Overview of the Second International Workshop on Presence: April 6-7, 1999, Colchester, England.

On the 6th and 7th of April 1999, the Second International Workshop on Presence was held at the University of Essex. The event was organized by Jonathan Freeman (currently at Goldsmiths College, University of London and at the University of Essex during the workshop) and Wijnand IJsselsteijn (IPO, Center for Research on User-System Interaction) as part of the European Commission ACTS TAPESTRIES project. The TAPESTRIES project was managed by the UK Independent Television Commission (ITC) and the workshop was sponsored by SONY, BT, and the ITC. The workshop program is followed by a brief introduction to presence and then by short summaries of each of the papers.