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Biomedical subjects

G Hoff

Publications and source records attributed to G Hoff.

At least 19 recordsLinked to original sources
PubMed2001

Smoking, folate and methylenetetrahydrofolate reductase status as interactive determinants of adenomatous and hyperplastic polyps of colorectum.

Most studies demonstrate increased risk of colorectal cancer (CRC) and adenomas in folate-deficient subjects or that high folate intake may afford some protection. Smoking increases such risk in some but not all studies. We investigated whether smoking, folate status and methylenetetrahydrofolate reductase (MTHFR) genotype predict the risk of adenomatous and hyperplastic polyps of colorectum. By colonoscopy, the type, number, size and extent of dysplasia of colorectal polyps were assessed in 443 subjects aged 63-72 years. We also determined RBC folate and the C667T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene. Smoking, folate status and the C677T MTHFR polymorphism were strong, interactive determinants of high-risk adenomas (HRAs, defined as adenomas > or =10 mm in diameter, adenomas with villous components or with severe dysplasia). The risk was particularly high in smokers with low folate and the CT/TT genotype (risk category T) and in smokers with high folate and the CC genotype (risk category C). With non-smokers with low folate and the CC genotype as reference, the odds ratios (OR, 95% CI) were 8.7 (2.5-29.7) in category T and 9.9 (2.6-38.4) in category C. Notably, this risk pattern was also observed for hyperplastic polyps. In conclusion, in smokers, high folate status may confer increased or decreased risk for HRAs, depending on the MTHFR genotype. These data demonstrate the strong gene-nutrition interaction involving the C677T MTHFR polymorphism.

Adenomatous Polyps↗
PubMed2001

Modulation of endotoxin-stimulated TNF-alpha gene expression by ketamine and propofol in cultured human whole blood.

AIM: Anesthetic agents have direct and indirect effects on immunocompetent cells but the molecular mechanisms of direct interactions are largely unknown. Therefore, the effect of propofol and ketamine on TNF-alpha gene expression was studied in cultured blood from healthy volunteers. METHODS: TNF-alpha was measured in blood cultured in the absence or presence of propofol or ketamine after stimulation with E. coli endotoxin. TNF-alpha concentrations were correlated with the expression of TNF-alpha mRNA in mononuclear cells. The half-life of TNF-alpha mRNA was assessed after addition of actinomycin D, an inhibitor of DNA-directed RNA synthesis. RESULTS: Propofol increased TNF-alpha mRNA (+42%) and protein (+44%) response while the addition of ketamine attenuated the TNF-alpha mRNA (-31%) and protein (-53%) response. The half-life of TNF-alpha mRNA was unaffected by the anesthetics. CONCLUSION: These data suggest that propofol and ketamine have opposite effects on transcription of the TNF-alpha gene. While the effects of propofol were observed with concentrations corresponding to an induction bolus, the effects of ketamine were restricted to higher concentrations.

Anesthetics, Dissociative↗
PubMed2001

Do undesirable effects of screening affect all-cause mortality in flexible sigmoidoscopy programmes? Experience from the Telemark Polyp Study 1983-1996.

There is substantial evidence for the beneficial effect of screening programmes aimed at reducing mortality from colorectal cancer (CRC). The effect on all-cause mortality, however, may not necessarily be beneficial. In the present study we used the follow-up results 13 years after a flexible sigmoidoscopy screening to evaluate the long-term effects of informing participants about findings at flexible sigmoidoscopy (FS) screening. There were no severe complications and there was no long-term difference in deaths related to whether there had been any mucosal rupture (biopsy or snare resection) or not. As a group, those who attended in 1983 and were informed that they had polyps tended to improve their smoking habits more than those informed that they had no polyps. Similarly, and in spite of more people giving up smoking, the group with polyps had a trend towards a smaller increase in BMI (+0.7 (95% CI 0.2-1.1)) than the polyp-free group (+1.2 (95% CI 0.9-1.6)) (P = 0.07). The observations suggest that flexible sigmoidoscopy screening may face an educational challenge to avoid unfavourable changes in the lifestyle of screenees, an effect that may more than outweigh the beneficial effect of screening.

Colonic Polyps↗
PubMed2001

Current diet and colorectal adenomas: a case-control study including different sets of traditionally chosen control groups.

High intake of fat and a low intake of foods rich in antioxidants and fibre are suggested to be associated with risk of colorectal adenomas. Inconsistency may, however, be due to dietary assessment problems or differences in the identification of cases and controls. We have compared 87 adenoma cases aged 50-76 years with 35 healthy controls and 35 'hospital' controls. All the controls were matched for sex and age (+/-5 years) and proven to be free of polyps. Current habitual diet was measured by a 5-day dietary record by weighing. Regarding the intakes of vegetable fat, protein, cholesterol, vitamin A, total vitamin D, edible fats, coffee and fish and fish products, the outcomes of the analysis depended upon the source of controls. However, an increased adenoma risk compared with either set of controls related to a low consumption of vegetables, cereals, iron, vitamin C and fibre and a high intake of total fat was found. This is suggestive of substantial differences, since bias due to abdominal symptoms, the dietary records or an inappropriate choice of controls, would have affected the estimations. The findings give further strength to the role of these dietary factors in the formation of precancerous lesions in the large intestine.

Adenoma↗
PubMed2000

Recurrence of urogenital Chlamydia trachomatis infection evaluated by mailed samples obtained at home: 24 weeks' prospective follow up study.

OBJECTIVES: To evaluate the rate of recurrence of genital Chlamydia trachomatis infection after antibiotic therapy in a population of patients drawn from general practice, and to evaluate whether retesting after antibiotic therapy was advisable and, if so, whether it could be based on a strategy involving samples obtained at home and mailed to the laboratory for analysis. METHODS: Prospective follow up study of 42 patients with genital C trachomatis infection drawn from general practice. Patients at or above the age of 18, with a positive urogenital swab sample obtained by a general practitioner were invited to participate. Follow up testing was based on LCR testing (LCx, Abbott diagnostics) of first void urinary and vaginal flush samples taken by the patients at home and mailed to the laboratory at weeks 2, 4, 8, 12, and 24 after antibiotic therapy. RESULTS: Cumulated incidence of recurrent infection was calculated to 29% (95% CI: 12%-46%) during the 24 weeks of follow up. Previous or present sexually transmitted diseases other than C trachomatis were significantly associated with recurrence (OR 6.1, p = 0.03). 89% of patients tested negative at week 2, and all patients tested negative at some point during the first 4-8 weeks. 84% of the test kits mailed to the patients were returned to the laboratory for analysis. CONCLUSIONS: Recurrence of C trachomatis after antibiotic treatment is a substantial problem. Retesting should be carried out, but not sooner than 12-24 weeks after treatment. Requiring patients to take tests at home appears to be a promising method for retesting.

Adult↗
PubMed2000

Smoking and colorectal adenomas: a case-control study.

A positive association between tobacco and colorectal adenomas has been suggested. Smoking is, however, also associated with 'poor' dietary habits, which in turn may be related to risk of adenomas. It is therefore of interest to study the relationship between smoking, diet and risk of colorectal adenomas in follow-up studies. We compared 87 adenoma cases to 35 'hospital' and 35 healthy controls (all controls were age- and sex-matched and proven to be free of adenomas). Smoking data were collected by an interview and a self-administrated questionnaire with a time interval of at least one month. After 3 years of follow-up, all polyps were removed. Our data indicate that smoking is associated with adenoma prevalence, but not necessarily with size, multiplicity, growth or recurrence of adenomas. Compared to both sets of controls, cases reported to have smoked more than 15 pack-years, or who are current smokers, had a fourfold increased frequency of adenomas (odds ratios 3.6-5.9). Smokers with adenomas had dietary habits that may also be associated with adenomas. The smoking estimates remained largely unchanged even after adjustments for dietary variables in multivariate analysis. This study lends support to the theory of an initiating role of tobacco smoke in neoplasia formation.

Adenoma↗
PubMed1998

Effect of intravenous anesthetics on spontaneous and endotoxin-stimulated cytokine response in cultured human whole blood.

BACKGROUND: Various anesthetics have been suggested to interfere with the immune system. The ability of leukocytes to express surface receptors and mediators is fundamental to a successful host defense. Therefore, the effects of intravenous anesthetics on cytokine release by leukocytes and expression of surface molecules known to modulate this response were determined. METHODS: Concentration-dependent effects of thiopentone, etomidate, propofol, ketamine, midazolam, and fentanyl on spontaneous and endotoxin (lipopolysaccharide; 1 microg/ml)-stimulated cytokine release were studied in whole blood from volunteers (n = 6) cultured for 25 h. In addition, expression of the lipopolysaccharide-recognition molecule CD14 and the major histocompatibility complex class II molecule human leukocyte locus A system-DR (HLA-DR) on monocytes were assessed using flow cytometry. RESULTS: All anesthetics studied elicited only minor effects on spontaneous cytokine release even at pharmacologic concentrations. However, expression density of CD14 was reduced in the presence of thiopentone, etomidate, and propofol, whereas HLA-DR was unaffected. Lipopolysaccharide-stimulated tumor necrosis factor response was inhibited by thiopentone (12.8% [median]; 7.6-18.8 [25-75 percentile]) of control, and ketamine (46.4% [median]; 44.4-56.4 [25-75 percentile]), at pharmacologic concentrations, whereas it was augmented even in the presence of low concentrations of propofol (172.3% [median]; 120.5-200.7 [25-75 percentile]). Ketamine additionally decreased the concentration of interleukin (IL)-1beta (14.8% [median]; 12.0-18.0 [25-75 percentile]). Release of IL-1 receptor antagonist (IL-1ra) was inhibited by thiopentone, etomidate, and propofol, whereas the same anesthetics increased IL-10 concentration simultaneously. Midazolam and fentanyl did not alter the concentrations of any cytokine. CONCLUSIONS: These results suggest a complex modulation of the cytokine response by the studied anesthetics in cultured whole blood. Although effects on spontaneous cytokine release by leukocytes were negligible, some anesthetics affected their ability to respond to lipopolysaccharide.

Anesthetics, Intravenous↗
PubMed1997

[Long-term result of a life style intervention group program].

156 former participants in a lifestyle modification programme for persons with coronary heart disease, or at high risk of developing this disease, were invited to a follow-up examination. The aim was to evaluate the long-term effect of a lifestyle intervention programme. Median time since completion of the programme was 3 years. The participants' serum cholesterol level at the time of the control examination was lower than before they attended the programme, but slightly higher than at the end of it. The body weight was similar at the control and before participation. The self-reported amount of physical activity of persons with established coronary heart disease was higher at the control examination than before the programme. For persons with no established coronary heart disease, the self-reported level of physical activity was the same before and after attending the programme. The most pronounced effect as regards a reduction of the risk factor profile was seen among the participants with established coronary heart disease. The number of smokers was reduced, but not significantly.

Aged↗
PubMed1997

[Integration of preventive medicine in an emergency department. A pedagogic model for improvement of communication].

At the Medical Department, Telemark Central Hospital, a project has been going on for five years now to evaluate consultations in lifestyle groups in preference to individual consultations for persons with dyslipidemia. 363 persons were recruited to participate in a series of 5 group consultations at intervals of 3 months, each session to last for 2 hours. Altogether 1469 consultations were of this type. After the first session 79% said they preferred lifestyle group consultations, rather than spending their share of the allotted time on personal consultations, and after the fifth session 81%. The concept has been extended to include patients with chronic disease (asthma and chronic inflammatory bowel disease), with the principal aim of improving the patients' understanding of their disease, and showing them how to control it themselves. The project has attracted much attention, and a consultant in preventive medicine has recently been appointed to the staff. We think it important in terms of impact that the initiative to establish local expertise in preventive medicine emerged from a department that deals with emergency admissions due to lifestyle-related diseases.

Adolescent↗
PubMed1996

Polypectomy of adenomas in the prevention of colorectal cancer: 10 years' follow-up of the Telemark Polyp Study I. A prospective, controlled population study.

BACKGROUND: The efficacy of polypectomy in preventing colorectal cancer (CRC) has never been demonstrated in a controlled, prospective study. This must be done by randomization within a population with a high prevalence of colorectal polyps, and the feasibility and safety of endoscopic screening examination is a prerequisite for this type of study. METHODS: The present study is a randomized, controlled study of the feasibility and safety of flexible sigmoidoscopic screening of a normal population sample of 799 men and women aged 50-59 years, findings at 2 and 6 years' colonoscopic follow-up, and the appearance of clinical colorectal cancer (CRC) after 10 years. RESULTS: The attendance rate was high, and there were no complications. After 10 years 1 of 400 in the screening group had developed CRC (in the group of 76 (19%) not attending for screening examination). Four of 399 controls developed CRC. CONCLUSIONS: Poor yield of polyps at follow-up, slow growth of in situ polyps, and no clinical CRC among screenees after 10 years provides support to infrequent or no colonoscopic follow-up after initial polypectomy in individuals with otherwise average risk of CRC.

Adenomatous Polyposis Coli↗
PubMed1992

Drinking water and the prevalence of colorectal adenomas: an epidemiologic study in Telemark, Norway.

This study was based on an endoscopic screening study for detection of polyps in the rectum and sigmoid colon in a randomized, normal population sample of 400 individuals aged 50-59 years. Family disposition for cancer and indicators of lifestyle (including dietary registration) were recorded. The 310 individuals received domestic drinking water from one out of four public water supplies. The participants were categorized according to the water supply connected to their house of residence. Drinking water was analysed monthly during 2 years for chloroform, total organic carbon, colour index, calcium, magnesium and chlorine. The overall prevalence of colorectal polyps was significantly higher in residents receiving chlorinated water with a high organic content when compared with recipients of water with a low organic content. There was no association between polyp prevalence and chloroform concentration in the drinking water. Multivariate analysis revealed that age, male sex, high BMI, smoking, few stools per week, high protein intake and low intake of fibre, iron and cruciferous vegetables were far more important for the presence of polyps than the total organic content in chlorinated drinking water.

Adenoma↗