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F A Macrae

Publications and source records attributed to F A Macrae.

46 records · Page 3Linked to original sources
PubMed1982

Colorectal cancer: knowledge and attitudes of doctors in Victoria.

Successful introduction of screening for early colorectal cancer will depend, at least in part, on doctors' knowledge and attitudes. A 34-item questionnaire was sent to a random sample of one in five doctors in Victoria, with a final completion rate of 65%. The survey revealed gaps of knowledge, particularly about recognition of high-risk groups. Only 12% were aware of the degree of increased risk faced by first-degree relatives of patients with colorectal cancer and only 10% recognised the similar increase in risk for people with a history of resected colorectal cancer. While 73% of doctors order faecal occult blood tests, only 9% were aware that the more reliable quaiac method was used for their patients. Overall, 38% considered that faecal occult blood testing was a practical method for screening for colorectal cancer. Most of the doctors who accepted occult blood screening would follow up a positive test with digital rectal examination (80%) and barium enema (75%), but only 58% would want sigmoidoscopy performed and 34% colonoscopy. The diagnostic potential of digital rectal examination and sigmoidoscopy was over-estimated by half of the doctors surveyed. Recognition of subjects at high risk for colorectal cancer, and knowledge about the proper use, follow-up, and potential for screening of faecal occult blood tests need emphasis in medical educational programmes.

Attitude of Health Personnel↗
PubMed1982

Relationship between patterns of bleeding and Hemoccult sensitivity in patients with colorectal cancers or adenomas.

Although Hemoccult (Smith Kline Diagnostics, Inc., Sunnyvale, Calif.) screening for colorectal cancer is based on detection of the peroxidase activity of blood, little is known about the relationship between patterns of bleeding from cancers or adenomas and sensitivity of the test slides. 51Cr-labeled blood loss was measured for a mean of 9.1 days in 46 patients with colorectal cancer and 28 with adenomas. Duplicate sets of Hemoccult II slides were prepared by the patients and mailed for testing with and without preliminary rehydration. Mean blood loss was significantly related to the site of the cancers, but was unrelated to Dukes' staging. Geometric mean levels of blood loss from the cancers were 9.3 ml/day for cecum and ascending colon, 1.5 ml/day for transverse and descending colon, 1.9 ml/day for sigmoid colon, and 1.8 ml/day for rectum. Rehydration increased Hemoccult sensitivity for blood independently of storage delay, almost doubling sensitivity at the levels of bleeding commonly encountered with cancers of the left side of the colon. Relating results to testing over 3 days, the Hemoccult false-negative rate for cancer was 31% without rehydration, falling to 9% with rehydration. With adenomas, blood loss and Hemoccult positivity were closely related to lesion size. The findings support the validity of 3-day occult blood testing as a method of screening for colorectal cancers and large adenomas, provided the test employed has a high sensitivity for blood. Further information is needed about the specificity of rehydrated Hemoccult slides in subjects following diets of differing peroxidase content. The degree to which rehydration of slides lowers the false-negative rate for cancer indicates that this modification of slide development should be evaluated in large population screening programs.

Adenoma↗
PubMed1982

Optimal dietary conditions for hemoccult testing.

Preliminary rehydration of Hemoccult II slides increases slide sensitivity for blood and lowers the false-negative rate for colorectal cancer. To test the effect of this modification on the false-positive rate due to peroxidase-containing foods, 156 healthy young subjects crossed between diets of differing peroxidase content. Hemoccult II slides were prepared in duplicate for testing with and without rehydration. When developed without rehydration, only seven (0.4%) of 1856 slides were positive, the positive results occurring with challenge diets containing 250 g rare red meat. With preliminary rehydration, 53 (5.7%) of 926 slides were positive, in 26 (17%) of the 156 subjects on a challenge diet that included rare red meat and uncooked fruit and vegetables. Well-cooked red meat also gave positive tests, Diets excluding red meat but with large quantities of uncooked fruit and vegetables produced only five positive results in 314 rehydrated tests, in 3 of 53 subjects. On a strict low-peroxidase diet, two of 310 tests, in 2 of 52 subjects, were positive. Rehydration of Hemoccult slides and exclusion of red meat and certain other high-peroxidase foods should give optimal sensitivity and specificity for colorectal cancer detection. The effect of these conditions on yield of lesions and false-positive rates should be tested in screening programs.

Adult↗
PubMed1980

Spontaneous bacterial peritonitis: reversible cause of deterioration in patients with cirrhosis.

Spontaneous bacterial peritonitis (SBP) in cirrhotic patients with ascites carries a mortality rate ranging from 50% to 90%. Eleven patients were diagnosed at The Royal Melbourne Hospital over a 25-year period. Fever was present in eight, abdominal pain in eight, rebound tenderness in six and pre-coma in four. In two, the peritonitis was silent. All five diagnosed by paracentesis survived, but the three patients first diagnosed at laparotomy died. The experience shows that SBP can be successfully treated with antibiotics. Because of the variable clinical features, a diagnostic paracentesis is recommended in all cirrhotic patients presenting with ascites.

Adolescent↗
PubMedDate not supplied

Brush border hydrolases in normal and neoplastic colonic epithelium.

Previous studies have suggested that abnormal expression of enzymes characteristic of the intestinal brush border might accompany colonic neoplasia and possibly facilitate identification of epithelium at risk of malignancy. To test this possibility, the distribution of the brush border enzymes sucrase-isomaltase (SIM), maltase-glucoamylase (MGA), aminopeptidase-N (APN) and diamino-peptidylpeptidase-IV (DPPIV) were studied by the immunoperoxidase method in biopsies from the rectum and caecum of normal subjects, and neoplastic and non-neoplastic tissues from patients with adenoma or cancer. Brush border enzymes were detected by immunohistochemistry more frequently in the caecum than the rectum (P less than 0.05) of normal subjects. Diamino-peptidylpeptidase-IV and APN were present in highest concentration at the brush border of the most mature colonocytes on the luminal surface with less staining in the crypt, whereas SIM and MGA staining of the brush border was as prominent on crypt cells as surface cells. While all cancers expressed at least one enzyme, there was heterogeneity of staining within tumours and a tendency to lose polarity of enzyme expression in cells, sometimes with dense staining of the cytoplasm. Distally situated adenomas uncommonly expressed a brush border enzyme (25%) and the only enzyme expressed in them was SIM. These finding indicate that these brush border enzymes are not exclusively expressed in the small intestine; DPPIV and APN are markers of the normal mature colonocyte and should prove useful as markers of differentiation. However, the change associated with neoplasia would not appear to be of clinically predictive value.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMedDate not supplied

Chromosome 2p linkage analysis in hereditary non-polyposis colon cancer.

Hereditary non-polyposis colon cancer (HNPCC) comprises 2-6% of the total colorectal cancer burden. Two families are described that show linkage between the HNPCC susceptibility gene and the markers D2S123 and D2S119 on chromosome 2p, producing multipoint lod scores of 3.62 and 3.83, respectively, in the largest pedigree. In our third family the multipoint lod scores for D2S123 and D2S119, -2.97 and -3.12, excluded localization of a susceptibility gene in this region indicating that there is at least one more gene that causes predisposition to HNPCC. The exclusion was based on at least one genotype for an individual who had multiple primary colon and extracolonic tumours and could not be considered to have had common forms of cancer. Our results therefore encourage further gene mapping to pursue the localization of additional HNPCC genes. These findings confirm the presence of the susceptibility gene for HNPCC, COCA1, on chromosome 2p. They allow the immediate identification of a subset of HNPCC families, and provide the means for presymptomatic testing of family members if sufficient number of members are available for study.

Chromosomes, Human, Pair 2↗