Toward embedded detection of polyps in WCE images for early diagnosis of colorectal cancer

Purpose   

Wireless capsule endoscopy (WCE) is commonly used for noninvasive gastrointestinal tract evaluation, including the detection of mucosal polyps. A new embeddable method for polyp detection in wireless capsule endoscopic images was developed and tested.

Methods   

First, possible polyps within the image were extracted using geometric shape features. Next, the candidate regions of interest were evaluated with a boosting based method using textural features. Each step was carefully chosen to accommodate hardware implementation constraints. The method’s performance was evaluated on WCE datasets including 300 images with polyps and 1,200 images without polyps. Hardware implementation of the proposed approach was evaluated to quantitatively demonstrate the feasibility of such integration into the WCE itself.

Results   

The boosting based polyp classification demonstrated a sensitivity of 91.0 %, a specificity of 95.2 % and a false detection rate of 4.8 %. This performance is close to that reported recently in systems developed for an online analysis of video colonoscopy images.

Conclusion   

A new method for polyp detection in videoendoscopic WCE examinations was developed using boosting based approach. This method achieved good classification performance and can be implemented in situ with embedded hardware.     

Sexually transmitted infections in European HIV-infected women: incidence in relation to time from infection. European Study on the Natural History of HIV Infection in Women

OBJECTIVES: To investigate the prevalence and incidence of sexually transmitted infections (STI) in HIV-infected women in relation to time from infection and sexual behaviour. DESIGN: The European study on the natural history of HIV infection in women is a prospective cohort study of 487 HIV-infected women with a known interval of seroconversion from 12 European countries. METHODS: Incidence was measured with person-time methods. Generalized estimating equations analysis was used to determine risk factors for STI. RESULTS: At entry, 15% of the women were diagnosed with at least one acute STI (chlamydial infection, trichomoniasis or gonorrhoea), 10% with at least one other STI (genital warts or genital ulcerations) and 13% with vaginal candidiasis. Although frequently diagnosed during follow-up, the occurrence of acute STI and vaginal candidiasis decreased, whereas the occurrence of other STI increased with ongoing time from HIV infection. Furthermore, women with a history of prostitution [relative risk (RR), 2.00; 95% confidence interval (95% CI), 1.20-3.33] and women with irregular condom use (RR, 7.74; 95% CI, 3.52-17.0) were at higher risk for an acute STI. CONCLUSIONS: Although STI diagnoses were frequent, the occurrence of acute STI declined with time from infection which might be explained by changed sexual behaviour over time. The occurrence of other STI increased with time from HIV infection, presumably due to reactivation as a result of immunosuppression.     

Isolated ostial stenosis: a peculiar anatomic form of coronary insufficiency in women

We report 5 cases of isolated ostial stenosis of the left main coronary vessel. Isolated ostial stenosis occurs preferentially in young or middle aged women for whom coronary insufficiency is usually not a serious threat. Patients with this type of lesion have characteristically severe angina of relatively recent onset. The condition may be difficult to diagnose at angiography, but a fall in pressure when the tip of the catheter enters the coronary lumen beyond the stenosis, a lack of reflux of the contrast medium into the sinus of Valsalva during intracoronary injection and its persistence in the coronary vessel should alert the investigator. A pathological study of 3 cases revealed typical atheromatous lesions in 2 patients (with extension of an aortic plaque to the left coronary ostium in one, and atheroma localized on the ostium in the other) and a purely fibrous lesions in a patient who had undergone thoracic radiotherapy 5 years previously. Although relatively rare, stenosis must be diagnosed in view of its sombre spontaneous prognosis (one patient died 3 days after coronary arteriography), of the risk of underestimating its frequency, and of the hazards of selective coronary catheterization in such patients (one of our patients died 15 minutes after coronary exploration).     

Development and evaluation of a laser catheter with tip fiberoptic for coronary angioplasty

A fiber-optic tip catheter has been developed for treating coronary and peripheral atherosclerosis percutaneously. The catheter is coupled to an ionised Argon laser emitting at an optical power of 1 to 7 Watts. It is designed to follow a guide wire and to perform tissue ablation by a new concept combining the effects of central vaporisation and peripheral thermal remodelling of the obstructed artery. This mode of function should considerably reduce the risks of false route previously encountered with laser angioplasty. The optical and thermic properties of the catheter prototypes were determined by physical methods. These experiments showed that the temperature of the metallic component of the catheter tip did not exceed 30 degrees C at a continuous power of 6 laser Watts when the flush was functioning. It attained 400 degrees C in the absence of the flush. The performances of the catheter were then tested in a number of in vitro experiments. First of all, the catheter tip was placed perpendicularly to atheromatous cadaver aortae to study the effect of vaporisation with respect to the laser power. The threshold of vaporisation was 1 Watt (irradiance: 1100 Watts/cm2). The catheter was then introduced into plastic tubes obstructed by atheromatous plaques. This experiment demonstrated the mechanical solidity of the catheter and its flexibility in difficult operating conditions: diameter 2mm, 45 degrees angles, irregular calcified plaques. It also showed that the optimal safety-efficacy laser power was 3 laser Watts and that the exposure times varied with respect to the nature of the plaques tested.(ABSTRACT TRUNCATED AT 250 WORDS)     

Multicenter epidemiological survey of primary myocardiopathies. Apropos of 380 cases]

A retrospective study of adult congestive cardiomyopathy was carried out; the admission criteria being heart failure with cardiomegaly after the exclusion of known causes of heart failure. Coronary artery disease was excluded by forming two sub groups, one with proven normal coronary arteries at angiography or autopsy and the other with only assumedly normal coronary arteries. The results concern the study of the incidence of this disease which has been regularly seen over the last 10 years in departments with a large number of referrals of cardiomyopathy. --Professional factors are analysed to see if there is a higher incidence amongst the working classes. --Other factors are analysed by comparison with three control groups: normal, coronary and valvular disease, and diabetes which may be a predisposing factor, but not the serum cholesterol which is decreased in these patients. There is a significant association with smoking and alcoholism and the main biological sign of the latter condition, macrocytosis. This is also found in both coronary sub groups. The isolation of this alcohol factor in the genesis of congestive cardiomyopathy implies the possibility of reversing or stabilising the myocardial damage after its withdrawal, so changing the severe diagnosis associated with this disease.     

Treatment of interstitial pneumonitis due to cytomegalovirus with ganciclovir and intravenous immune globulin: experience of European Bone Marrow Transplant Group.

Data on 49 allogeneic bone marrow transplant (BMT) recipients who developed interstitial pneumonia due to cytomegalovirus (CMV) were collected retrospectively. All patients were treated with ganciclovir and high doses of intravenous immune globulin, although types of immune globulins and schedules of treatment varied. Seventeen (35%) of 49 patients responded to treatment. Thirty days after the diagnosis of interstitial pneumonia, the survival rate among patients was 31%. CMV was detected in 81% of patients on whom autopsies were performed. The survival rate among patients who received total body irradiation (TBI) was significantly lower (11 [27%] of 41) than that among patients who did not receive TBI (six [75%] of eight; odds ratio = 12.3; P = .009). No other factor, including age, grade of graft-versus-host disease, types and dose of immune globulin used, or dose of ganciclovir, was correlated to survival. These results show that although survival of allogeneic BMT recipients with CMV interstitial pneumonia has improved, more than one-half of the patients still died of pneumonia. Thus, both prophylaxis for and treatment of CMV infection must be improved.     

Comparison of cimetidine and ranitidine on 24-hour intragastric acidity and serum gastrin profile in patients with esophagitis

Twenty-four-hour intragastric pH and serum gastrin profiles were monitored in six male asymptomatic patients who previously were found to have esophagitis on endoscopy and biopsy. They received cimetidine 300 mg qid (C), ranitidine 150 mg bid (R), or placebo (P) for one week each, utilizing the Latin-square design. The mean BAO was 0.4 +/- 0.2 mmol/hr, and the pentagastrin-stimulated MAO was 21.2 +/- 3.2 mmol/hr. In the P-treated patients, the pH fluctuated between 1.8 and 3.5 and over 90% of the readings were less than pH 4. As compared to P, both C and R significantly suppressed H+ after breakfast, overnight, and over the 24-hr period. The mean pH after lunch was significantly higher in R than in P, but not in C. Over the 24-hr period, a higher percentage of the readings were above pH 4.0 in R as compared to C. During the night, 50% of the pH readings were above pH 4.0 in C and R, whereas in P 50% of the pH readings were less than pH 2.0. The integrated gastrin responses after each meal were similar in C and R and were greater than in P. The biphasic response of the ratio of H+ and gastrin (H+/G) following each meal was suppressed by both H2-receptor antagonists, with numerically lower values obtained in R than in C. This study suggests that ranitidine 150 mg bid is superior to cimetidine 300 mg qid in suppressing the 24-hr intragastric acidity.     

Association of the R92Q TNFRSF1A mutation and extracranial deep vein thrombosis in patients with Behçet's disease

OBJECTIVE: Beh?et's disease is a chronic, relapsing, multisystemic inflammatory disorder characterized by recurrent oral and genital ulcers and by ocular, articular, vascular, and central nervous system involvement. The tumor necrosis factor alpha (TNFalpha) pathway is likely involved in the pathophysiology of Beh?et's disease. One of the 2 TNFalpha receptors is TNF receptor superfamily 1A (TNFRSF1A). We searched for R92Q TNFRSF1A mutations in patients with Beh?et's disease. METHODS: A search for TNFRSF1A mutations was performed by polymerase chain reaction amplification of the TNFRSF1A gene, followed by denaturing high-performance liquid chromatography scanning. RESULTS: Among the 74 unrelated European patients with Beh?et's disease, 5 (6.8%) carried the R92Q TNFRSF1A mutation. The frequency of the R92Q mutation in patients with Beh?et's disease was significantly higher than that in controls (P = 0.006 by Fisher's exact test). Deep vein thrombosis was significantly associated with the R92Q mutation (P = 0.001 [with Bonferroni adjustment for multiple comparisons]). Among the 30 patients with thrombosis, 10 had cerebral thrombophlebitis. None of these patients had the R92Q mutation. Among the 20 patients with Beh?et's disease who had extracranial deep vein thrombosis, 6 had the R92Q mutation, whereas 14 did not (P < 0.0001) CONCLUSION: The R92Q mutation in patients with Beh?et's disease is associated with an increased risk of extracranial venous thrombosis. This new finding may help in understanding the complex prothrombotic state in patients with Beh?et's disease.