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Biomedical subjects

G Hoff

Publications and source records attributed to G Hoff.

At least 73 records · Page 4Linked to original sources
PubMed1988

Colorectal adenomas and food. A prospective study of change in volume and total mass of adenomas in man.

In an endoscopic population screening study for detection of colorectal polyps the diet was registered before ascertaining whether polyps were present. Polyps less than 5 mm in diameter were followed up for 2 years before removal and histologic diagnosis. The relative risk of an increase both in the volume of registered adenomas (excluding new adenomas) and in the total mass of adenomas (including new adenomas) showed a trend towards an inverse relationship with intake of dietary fiber, non-fiber carbohydrate, and cruciferous vegetables, reaching the significance level only for intake of dietary fiber for increase of adenoma volume in men. A trend towards a positive relationship between growth and total fat intake was more inconsistent, although the significance level was reached for the relative risk of increase in adenoma mass for men. These prospective observations with regard to polyp-bearing individuals agree with previous incidence and prevalence data that have indicated a relationship between dietary habits and colorectal carcinogenesis.

Adenoma↗
PubMed1987

Humoral immunity in measles infection: a critical factor?

Cell-mediated immunity is generally regarded as the essential factor in recovery from measles infection. In other viral infections humoral immunity has been considered a critical factor when antibody titres were correlated with outcome or when serum therapy proved protective. A review of available studies of severe-to-fatal cases of measles infection having non-neurological symptoms indicate that the antibody response is depressed in virtually all cases. The current view of immune globulin being an ineffective therapeutic agent is based on treatment of measles encephalitis; in fact, the least effect should be expected among encephalitis cases since some already have antibodies from the onset of symptoms. Larger examinations of measles with other than neurological symptoms suggest that immune globulin has a beneficial impact on the clinical course of infection. There are indications that hyperimmune globulin increases the efficacy of this form of treatment. Since measles is still a major cause of hospitalization and mortality, further studies of the therapeutic effect of specific immune globulin are warranted. From our current knowledge, both the humoral and cell-mediated immunity seem to be critical factors in recovery from measles infection.

Antibody Formation↗
PubMed1987

Relationship between tobacco smoking and colorectal polyps.

A prospective endoscopic screening examination of a randomized population sample of 200 men and 200 women, aged 50-59 years, enabled the differentiation between individuals with and without polyps in the rectum and sigmoid colon. Both number of years of smoking and percentage years of life with smoking were associated with the presence of adenomas and hyperplastic polyps, both for men and women. No relationship was found between these factors or the daily number of cigarettes and the degree of dysplasia or the size or multiplicity of polyps. Two years' follow-up examination showed a tendency to fewer new polyps among male ex-smokers compared with smokers; however, the difference was not quite significant. No significant difference was found when comparing smokers with never smokers. In the relatively smaller groups of women no significant difference with regard to number of polyps was found among smokers, ex-smokers, and never smokers. The results provide evidence for an association between smoking and colorectal neoplasia and may suggest an initiating effect of smoking on carcinogenesis in the colon and rectum.

Adenoma↗
PubMed1986

High measles mortality in infancy related to intensity of exposure.

In a West African urban community, measles infection in infants was examined over 5 years (1979-1983). In the age group 0 to 11 months, measles mortality was higher among secondary cases (infected in the house) than among index cases (infected outside the house), and the proportion of secondary cases was significantly higher for this age group than for older children. Intensive exposure related to the social pattern of disease transmission may be important in explaining the high infant mortality observed with measles in developing countries. Mortality during the first 12 months of life increased with age, presumably because of the decrease of maternally derived measles antibodies. In children younger than 6 months of age, who are usually considered to be protected by maternal antibody, intensive exposure may lead to infection, as demonstrated by a high level of measles-specific antibodies in some children exposed to an older sibling with measles. The aim of public health policies should be to change conditions of exposure.

Antibodies, Viral↗
PubMed1986

Epidemiology of polyps in the rectum and sigmoid colon. Discriminant analysis for identification of individuals at risk of developing colorectal neoplasia.

In an endoscopic population screening examination for detection of colorectal polyps among 324 men and women aged 50-59 years, adenomas greater than or equal to 5 mm in diameter were found in 38 individuals, and 212 were polyp-free. Dietary registration was performed by 155 individuals on a case/control basis. At 2 years' follow-up study polyps less than 5 mm in diameter were also removed. This rendered a total of 39 adenoma patients and 59 polyp-free individuals available for a combined analysis of both case history and dietary information. Application of a linear discriminant model on the combined clinical and dietary information enabled us to select a possible set of variables to characterize 88 out of 98 individuals (90%) correctly as adenoma patients or polyp-free individuals. However, when only case history information was used for the total material of 38 adenoma patients and 212 polyp-free individuals, only 189 out of 250 individuals (76%) were correctly classified. Although age, smoking habits, and a family history of colorectal cancer appeared as useful variables in the discriminant function, this study demonstrated the importance of nutritional factors in characterization of adenoma patients in the present age group of 50-59 years. In the present study we could not find any set of case history information which could indicate the usefulness of a questionnaire-based 'pre-screening' to guide recommendations for endoscopic screening examination.

Colonic Polyps↗
PubMed1986

Epidemiology of polyps in the rectum and colon. Recovery and evaluation of unresected polyps 2 years after detection.

In an endoscopic population screening study for colorectal polyps among 200 men and 200 women, 50-59 years of age, 215 polyps less than 5 mm in diameter were left in situ for the present 2-year follow-up examination. The attendance rate was 102 of 106 (96%) for polyp patients and 77 of 90 (86%) in the control group. Of 194 polyps, 143 (74%) in the 102 polyp-bearing individuals were recovered for histological evaluation and 57 polyps were registered as new. Ninety-nine (50%) of the polyps were hyperplastic, 45 (23%) were adenomas, and 45 (23%) were mucosal tags. Both growth and regression of polyps were registered. Regression was commoner in the distal part of the rectum than in the proximal part or distal sigmoid colon. Growth was similar for recovered adenomas and hyperplastic polyps, whereas mucosal tags more often showed diminution in size. No polyp had reached a size of more than 5 mm in 2 years, and no case of severe dysplasia or carcinoma was registered. The estimated total polyp mass more than doubled both for adenomas and hyperplastic polyps. It is concluded that the time interval between initial examination with removal of polyps 5 mm or larger in diameter and the first follow-up examination may safely be set at 2 years.

Colonic Polyps↗
PubMed1986

Epidemiology of polyps in the rectum and sigmoid colon. Evaluation of breath methane and predisposition for colorectal neoplasia.

The clinical significance of methanogenic bacteria in large-bowel carcinogenesis has not been established so far. As part of a screening study of a randomized population sample of 200 men and 200 women aged 50-59 years, the present breath methane study was designed to gain further information on methane excretion in relation to premalignant colorectal lesions, familial cancer disposition, and dietary fat and fiber. Testing for breath methane excretion did not contribute towards the identification of individuals with premalignant colorectal lesions and therefore should probably not be considered a screening tool.

Adenoma↗
PubMed1986

Epidemiology of polyps in the rectum and sigmoid colon. Evaluation of nutritional factors.

Epidemiological studies have suggested an association between diet and colorectal cancer. Case/control studies, however, have been scarce, and studies based on interview with cancer patients who have symptoms from their cancer are inevitably prone to bias. An endoscopic population screening study for detection of colorectal adenomas enabled a double-blind registration of diet during 5 consecutive weekdays. Neither the participant nor the dietitian was informed of the findings at endoscopy. The estimation of 23 nutritional components was based on analysis of local commercial food and on the composition of foods in Norway. Results showed increasing consumption of fat and decreasing consumption of fiber and cruciferous vegetables in the presence of increasing neoplastic changes. The present material will form the basis for dietary-related follow-up studies.

Colonic Neoplasms↗
PubMed1985

Epidemiology of polyps in the rectum and sigmoid colon. Size, enzyme levels, DNA distributions, and nuclear diameter in polyps of the large intestine.

Enzyme activity and cell cycle variables were measured in 38 adenomas and 9 hyperplastic large-intestinal polyps equal to or larger than 5 mm in diameter. The polyps were resected endoscopically from patients 50-59 years old. A significantly higher activity of lactate dehydrogenase (LD) was found in polyps from women than in those from men. A higher LD and activity was also observed in adenomas with moderate to severe dysplasia than in those with mild dysplasia. A significantly higher activity was found for LD and glucose-6-phosphate dehydrogenase (G6PD) in adenomas greater than or equal to 10 mm than in adenomas less than 10 mm in diameter. DNA flow cytometry showed that all hyperplastic polyps were diploid and that two of the adenomas had an aneuploid DNA stemline in addition to the diploid one. The S-phase fraction varied from 3.5% to 26.5% and the G2 fraction from 0.4% to 6.7%. Two overlapping populations were found, based on nuclear size measurements. Hyperplastic polyps had almost only small nuclei, whereas adenomas had both small and large nuclei in various ratios. No statistical correlations were found between the S-phase or G2-phase fractions and polyp size or the presence of dysplasia. The number of adenomas with aneuploidy was too small to disclose a relationship to polyp size or enzyme activity. The increased enzyme activity in larger polyps and in polyps from women may point to certain risk factors in these special groups. The results indicate a further need for studies of combination of markers for prognostic evaluation of large-intestinal adenomas.

Adenoma↗
PubMed1985

Epidemiology of polyps in the rectum and sigmoid colon. Histological examination of resected polyps.

In an endoscopic screening study of rectosigmoidal polyps in a defined normal population aged 50-59 years, polyps 5 mm or larger in diameter were removed by diathermic snare resection for histological examination. Histological examination was possible in 50 of 55 polyps removed during colonoscopy from 27 men and 17 women. Of these polyps 41 (82%) were adenomas--12 with moderate dysplasia, 1 with severe dysplasia, and 2 with intramucosal carcinoma. In addition, a small ulcerating carcinoma, Dukes stage A, was found. A greater extent of dysplasia was found in rectosigmoidal adenomas in women, whereas more polyps were found in both distal and proximal parts of the colon among men. The size of adenomas and degree of dysplasia were unrelated to color of the lesions.

Adenoma↗
PubMed1985

Epidemiology of polyps in the rectum and sigmoid colon. Design of a population screening study.

The design of a population screening study, including endoscopic screening for polyps in the rectum and sigmoid colon, was tested in a defined population sample of 200 women and 200 men aged 50-59 years. The attendance rate was 81%. A simple bowel cleansing procedure performed immediately before the examination gave satisfactory conditions for endoscopic examination in 94% of attendants. Polyp prevalence was 35%. The present material and results represent the basis for further follow-up studies of risk factors for the development of cancer in the same group of individuals.

Colonic Polyps↗
PubMed1985

Epidemiology of polyps in the rectum and sigmoid colon. Endoscopic evaluation of size and localization of polyps.

The reproducibility of polyp localization and size measurements was tested to evaluate the reliability of observations during follow-up examinations of sigmoidoscopically diagnosed polyps. Our findings suggest that 25% of polyps less than 5 mm in diameter but only 5% of those larger than 5 mm are likely to be missed by a single endoscopic examination. Localization measurements made during insertion and withdrawal of the endoscope on different days of examination diverged proximal to 30 cm from the anal ring during repeat colonoscopy. Otherwise, reproducibility was good, demonstrating that sigmoidoscopy may be a fairly accurate procedure for evaluation of site and size of polyps during follow-up studies.

Colonic Polyps↗