The Quebec Association of Gastroenterology position paper on colorectal cancer screening - 2003.

Colorectal cancer is a leading cause of death and the third most common cancer in Canada. Evidence suggests that screening can reduce mortality rates and the cost effectiveness of a program compares favourably with initiatives for breast and cervical cancer. The objectives of the Association des gastro-entérologues du Québec Task Force were to determine the need for a policy on screening for colorectal cancer in Quebec, to evaluate the testing methods available and to propose one or more of these alternatives as part of a formal screening program, if indicated. Fecal occult blood testing (FOBT), endoscopy (including sigmoidoscopy and colonoscopy), barium enema and virtual colonoscopy were considered. Although most clinical efficacy data are available for FOBT and sigmoidoscopy, there are limitations to programs based on these strategies. FOBT has a high false positive rate and a low detection yield, and even a combination of these strategies will miss 24% of cancers. Colonoscopy is the best strategy to both detect and remove polyps and to diagnose colorectal cancer, with double contrast barium enema also being a sensitive detection method. The Task Force recommended the establishment, in Quebec, of a screening program with five- to 10-yearly double contrast barium enema or 10-yearly colonoscopy for individuals aged 50 years or older at low risk. The program should include outcome monitoring, public and professional education to increase awareness and promote compliance, and central coordination with other provincial programs. The program should be evaluated; specific billing codes for screening for colorectal cancer would help facilitate this. Formal feasibility, effectiveness and cost-effectiveness studies in Quebec are now warranted.

The Incidence of Salmonella , Campylobacter , and Yersinia enterocolitica in Swine Carcasses and the Slaughterhouse Environment.

This study was done to evaluate the degree of contamination of cooler-ready hog carcasses and the slaughterhouse environment by Salmonella spp., Campylobacter spp. and Yersinia enterocolitica . Samples from diaphragms and feces were collected from 200 market hogs in a Quebec slaughterhouse. Scalding-tank water and environmental swabs were also collected in the slaughterhouse. Specimens were tested for the presence of Salmonella spp., Y. enterocolitica , and Campylobacter spp. Salmonella spp. were isolated from 45 (10%) of 448 samples. The distribution of the isolates were slaughtering floor (8.9%), feces (80.2%), cold-room floor (4.4%), and diaphragms (6.7%). Campylobacter spp. were isolated from 247 (61.7%) of 400 specimens, and C. coli , C. jejuni , and C. laridis accounted for 97%, 2%, and 1% of isolates, respectively. Ninety-nine percent of fecal samples were positive for the presence of C. coli . Y. enterocolitica was found in 42 (9.3%) of the 448 specimens. Of these, 85.7%, 11.9%, and 2.4% of the isolates came from fecal, diaphragm, and cold-room floor samples, respectively. Neither Salmonella spp. nor Y. enterocolitica were isolated from scalding-tank water.

Differentiation of radiation-induced fibrosis from recurrent pulmonary neoplasm by CT.

We describe and compare the computed tomographic (CT) manifestations of radiation fibrosis and recurrent neoplasm and consider the potential application of CT in the follow-up of patients after radiotherapy for bronchogenic carcinoma. Thirty-one patients were evaluated in this retrospective study. The CT findings in 20 patients with radiation fibrosis were compared with those in 11 patients with recurrent tumor. In 19 of the 20 patients with radiation fibrosis, CT allowed demonstration of consolidation, with a straight lateral margin and containing ectatic air-containing bronchi. In 9 of the 11 patients with recurrent tumor, CT showed a soft tissue mass with a convex lateral border and without air-containing bronchi. Twenty of the 31 patients had a suspected recurrence on plain chest radiographs. CT permitted accurate differentiation between radiation fibrosis and recurrent tumor in all patients, with the exception of two who had large pleural effusions. Because of its great specificity, CT appears useful in complementing chest radiographs in the follow-up of patients after radiotherapy.

Computed tomography used to exclude pneumothorax in bullous lung disease.

We report two patients with bullous lung disease and suspected pneumothorax on plain chest radiographs. Chest tubes were inserted in both patients, but no clinical or radiological improvement occurred. Computed tomographic (CT) scans were then performed and showed bullous lesions without any pneumothorax. This permitted the removal of unnecessary chest tubes. In selected patients with severe bullous disease, CT may be useful, either on admission or later, when the diagnosis of pneumothorax by conventional radiographs is doubtful.

The use of Hanks'--pipes buffers in the preparation of human, normal leucocytes for TEM observation.

It is suggested that the use of Hanks' + pipes + sucrose buffers, in combination with glutaraldehyde and osmium tetroxide fixatives, represent an excellent mode of preparation of fresh and cultured peripheral blood leucocytes, not only for transmission electron microscopy observation of these cells but also for scanning electron microscopy.

Streptokinase thrombolysis of a chronically thrombosed mitral prosthetic valve.

Thrombus obstruction of a prosthetic heart valve is usually treated surgically. We report a well-documented case of an obstructed mitral prosthetic valve where fibrinolytic treatment was successful. Furthermore the thrombus formation probably had occurred 6 months earlier. Thus fibrinolysis appears to be a safe alternative to surgery although late occurrence of thrombosis may be possible.

Tannic acid- and thiocarbohydrazide-mediated osmium tetroxide binding in the preparation of human leucocytes for SEM observation.

Normal human leucocytes, successively treated with glutaraldehyde-tannic acid-osmium tetroxide-thiocarbohydrazide-osmium tetroxide-thiocarbohydrazide-osmium tetroxide, were prepared for scanning electron microscopy observation. These cells produced well-contrasted, non-charging scanning images compatible with metal-evaporated material. Further, the mononuclear and polymorphonuclear cells resisted shrinkage during dehydration and critical point drying, thus allowing much improved images at high magnification than those covered with evaporated metal. In all cases at least a second thiocarbohydrazide-osmium tetroxide treatment could not be avoided.

Traumatic subarachnoid-mediastinal fistula mimicking a ruptured aorta.

A 35-year-old man, injured in an automobile accident was found to have a subarachnoid-mediastinal fistula that mimicked a ruptured aorta. Of 16 reported cases of traumatic subarachnoid-mediastinal fistula, this is only the third in which the fistulous communication was with the extrapleural space only. The possibility of subarachnoid-mediastinal fistula, although rare, should be entertained in injuries to the thoracocervical spine when neurologic symptoms are present.

The simultaneous use of Hanks' and Hepes buffers in the preparation of human leucocytes for SEM observation.

Leucocytes were isolated from the peripheral blood of normal individuals and prepared for SEM observation. The addition of the buffer Hanks and Hepes to the glutaraldehyde fixative was found to maintain the initial ambient pH throughout cell manipulation, and to allow satisfactory preservation of surface architecture.

SEM observation of cultured, mitogen-stimulated leukocytes. Cells obtained from patients with acute myeloblastic and chronic lymphocytic leukemias.

SEM observation of acute myeloblastic leukemia cells, incubated for 20 h with the mitogens pokeweed and phytohaemagglutinin, showed these to have elongated structures that were either smooth or partially covered by thumblike figures. By contrast, the chronic lymphocytic leukemia cells possessed more compact shapes and some were covered with blebs of varying sizes.

The use of various buffers in the preparation of human lymphocytes for SEM observation.

A study is presented of various buffers utilized in the preparation of human lymphocytes for scanning electron microscopy. Of nineteen different buffers tested, Hanks' balanced salt solution +0.04 mol sucrose appeared most adequate for satisfactory preservation of lymphocyte surface architecture.

Preparation of human leukocytes for SEM observation: a modified technique.

Variations in the mode of preparation, type of fixation and leukocyte collection can plan an important part in the determination of the surface structure of a given population, and can result in modifications of the microprojections, and their number, evident on the cell surface. We present preparatory modes that circumvent these difficulties, and the results obtained clearly show that the techniques are profitable, appear essential for the preservation of cell population and integrity, and allow accurate scanning electron microscopy observations without resort to time consuming procedures. Indeed, the entire process can be completed in one day.

Isolation of enterotoxigenic Aeromonas from fish.

This paper reports two different enterotoxigenic classes of the genus Aeromonas isolated from fishes. Strains of A. sobria were isolated from healthy fishes only wheras strains of A. hydrophila were isolated from both healthy and moribund fishes. Aeromonas sobria and hydrophilia strains produced a cytotoxic factor and were highly proteolytic. Seventy-five percent (75%) of the A. sobria strains produced only one type of hemolysis on 5% blood agar, but 92% of the A. hydrophilia produced two types of hemolysis. Enterotoxigenicity of all strains was tested by the rabbit gut loop technique and the suckling mouse test. Most of those Aeromonads were enterotoxigenic. Enterotoxigenic strains appeared to produce two different enterotoxins which were antigenically related, but they seemed to have different mechanisms of action. Enterotoxins of Aeromonas were shown to be antigenically different from those of E. coli.

The fine structure of Strongylocentrotus purpuratus testes.

The fine structure os Strongylocentrotus purpuratis testes has been examined. No obviously important differences appear to exist between the description reported here and the published fine structure of testes obtained from other sources. The most useful fixative was found to be a mixture of glutaraldehyde-paraformaldehyde.