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Biomedical subjects

D Trichopoulos

Publications and source records attributed to D Trichopoulos.

At least 415 records · Page 23Linked to original sources

Effect of corynebacterium parvum in the induction and course of mycoplasma arthritis of mice.

The effect of the immunostimulant C. parvum on the establishment and course of mycoplasma arthritis of mice was investigated. Male Swiss albino mice were injected intra-venously with M. arthritidis culture and intraperitoneally with C. parvum. It was shown that mice immunostimulated with C. parvum were significantly protected against the establishment of arthritis if the mycoplasma was given 9 days after the immunostimulant. However, when the arthritis was established C. parvum had no effect on the course of the arthritis. A close association between mycoplasma arthritidis and synovial cells in proposed as a possible explanation of this observation.

Animals↗

Obesity, serum cholesterol, and estrogens in premenopausal women.

Creatinine-adjusted levels of estrone, estradiol, and estriol were determined in luteal phase urine specimens of 200 premenopausal women from rural areas of Greece. The relation of each estrogen to height, weight, obesity index, and serum cholesterol was studied by multiple regression, controlling for age, age at menarche, and ovulation status (ovulation, anovulation, undetermined). No consistent relation between any of the somatometric variables and any of the urine estrogens emerged from the statistical analysis, but among older women (30-40 years old) both estrone and estradiol were positively associated with serum cholesterol (p less than 0.05). The data provide no support for the hypothesis that the relationship between body weight and breast cancer risk is mediated through an influence of body weight on estrogen levels--at least in premenopausal women. On the other hand the data on serum cholesterol levels are consonant with the idea that qualitative aspects of nutrition may affect breast cancer risk among older (e.g., postmenopausal) women.

Adolescent↗

Urine estrogens, frequency of ovulation, and breast cancer risk: case-control study in premenopausal women.

Urine specimens from 94 premenopausal women with breast cancer and from 70 control women have been compared with respect to concentration of the three major estrogen fractions and to frequency of ovulation as assessed by urine pregnanediol. The probability of anovulation (0.14 in the breast cancer patients and 0.09 among the controls) was not significantly higher among the women with breast cancer (P approximately 0.30). However, there was a positive association between urine estrogen concentration and breast cancer risk. The association was statistically significant (P less than 0.05) for each of the three estrogens measured and in both the follicular and the luteal phases of the menstrual cycle; the relative risk increased from 1 in the referent category (less than 5 micrograms estrogen/g creatinine) to about 3 in the highest category (greater than or equal to 15 micrograms estrogen/g creatinine). The association between urine estrogens and breast cancer risk was consistently stronger when the comparison was restricted to specimens collected in menstrual cycles during which ovulation occurred.

Breast Neoplasms↗

Epidemiologic research on the role of studying and urban environment in the development of myopia during school-age years.

Four hundred seventy-four Greek male subjects received an ophthalmologic examination and completed a questionnaire. The following were found: (1) the years of studying and urban residence are factors that strongly influence the prevalence of myopia; discriminant factor analysis classified correctly 81% of the subjects into the myopic or the nonmyopic group; (2) the incidence of myopia is significantly higher in the studying v the nonstudying groups; (3) the prevalence of myopia is higher in the more educated group; (4) there is no statistical difference between the orientation of myopes and nonmyopes toward studies or other occupations; (5) although the presence of myopia is determined by the years of studying and urban residence, the degree of myopia is not influenced to a statistically significant level by these factors; and (6) the results indicate that the interaction of these two variables is more significant in their contribution to the onset of myopia than the sum of each variable alone.

Adolescent↗

Age at menarche, urine estrogens and breast cancer risk.

In 511 nulliparous women aged 15-19 years and 347 aged 30-39, an analysis has been undertaken of the relationship of urine concentrations of the three principal estrogens to age, age at menarche and Quetelet's index of adiposity. The analysis was undertaken by means of multiple regression, controlling for each of the 12 centers from which the data originated, as well as for the other study variables. In the younger women, age was strongly and positively related to concentrations of E1 and E2 and less so to E3. In the age group 30-39, follicular phase specimens showed positive relationships with age for all three fractions but luteal specimens did not. Age at menarche showed inverse relationships to levels of E1 and E2 which were significant in the younger but not in the older age group. The associations of estrogens with Quetelet's index were weak and not statistically significant. The data suggest that women whose menarche occurs early not only have a longer duration of exposure to estrogens during years which are probably important in the initiation of breast cancer but, in addition, their exposures are at a higher level during those years and probably at later ages also. These observations support the hypothesis that the mechanism of the association of early menarche with breast cancer risk is via the association of both with estrogen stimulus.

Adipose Tissue↗

Age at menarche, probability of ovulation and breast cancer risk.

An analysis is undertaken of the frequency of ovulation in 17 groups of women aged 15 to 19 who had been the subjects of other studies. A urine specimen of at least 8 h accumulation had been provided on the 20th or 21st day of a menstrual cycle by 681 women. Analysis is restricted to 431 specimens which had been collected between 11 and 3 days prior to the onset of the subsequent menstrual period. A pregnanediol concentration of less than 1 mg per litre in such a specimen was taken as evidence that the cycle was anovular. The probability of a cycle being anovular was inversely and significantly related to the number of years since menarche, and, with years since menarche held constant, was positively but not significantly associated with age at menarche. This observation indicates that women with early menarche do not have a longer duration of exposure to anovular cycles than do those whose menarche is delayed, and that variation in the duration of exposure to post-menarcheal anovular cycles does not explain the association of breast cancer risk with early age at menarche. The 17 groups of women were classified into four categories according to ethnic origin and breast cancer incidence in the populations from which they derived. Anovular cycles were not more common in the high-risk groups; indeed, the two centers in the lowest risk category had the highest proportion of anovular cycles.

Adolescent↗

Does hepatitis B virus cause hepatocellular carcinoma?

Evaluation of the hypothesis of an association between hepatitis and hepatocellular carcinoma (HCC), first suspected on pathologic grounds, was made easier by the discovery of hepatitis B surface antigen. Population correlation and analytical epidemiologic studies established that there is a strong and specific association between hepatitis B virus (HBV) and HCC. The association is restricted to chronically active forms of HBV infection and is universally present, equally strong in the USA and Europe as in Africa and Asia. The causal nature of the association between HBV and HCC appears indisputable, even though the pathogenesis of HBV-related HCC has not been established. There is no evidence to support any of the non-causal interpretations, i.e., that a third factor causes both persistence of HBV and HCC, or that HCC increases susceptibility to the HBV carrier state. Since about 200 million people are hepatitis B surface antigen carriers, HBV would appear to be second only to cigarette smoking as the most important known human carcinogen. However, a substantial proportion of HCC cases throughout the world show no evidence of active HBV infection; for those cases other causal agents must be invoked. Aflatoxin may be an important etiologic factor in Africa and Asia, whereas in Europe and the USA cigarette smoking and alcohol drinking are serious and numerically important suspects for hepatocellular carcinogenicity. Several other factors, including natural and synthetic chemical carcinogens, infectious agents and steroid hormones are also suspected, but the supporting evidence is weak and the numerical importance of the factors probably limited.

Aflatoxins↗

An epidemiologic survey of thyroid enlargement among schoolchildren in a non-endemic area.

In 534 unselected schoolchildren aged 6-14 yr from the greater Athens area the size of the thyroid gland was assessed by palpation, and information was obtained on sex, age, height, weight, skinfold thickness, socioeconomic class, eye colour and urinary iodine excretion. The results were analysed by discriminant analysis. Altogether 14% of these children had a thyroid enlargement (7% had a definite goitre and another 7% a smaller enlargement). The set of variables studied were significantly discriminatory (Wilk's lambda 0.926, p approximately equal to 0.004). Most of the discrimination was accounted for by height (positive association, b coefficient 0.0114, SE 0.0029, t = 3.95) and weight (negative association, b coefficient 0.0107, SE 0.0030, t = 3.61). No other parameter, including iodine excretion, showed a significant difference between goitrous and nongoitrous. It is concluded that the only genuine difference is that goitrous are heavier for a given height or shorter for a given weight, i.e. more obese. The reason for which obesity protects from sporadic nontoxic goitre is not entirely clear, but probably both nutritional and genetic factors are involved.

Adolescent↗

Coffee and cancer of the pancreas.

We questioned 369 patients with histologically proved cancer of the pancreas and 644 control patients about their use of tobacco, alcohol, tea, and coffee. There was a weak positive association between pancreatic cancer and cigarette smoking, but we found no association with use of cigars, pipe tobacco, alcoholic beverages, or tea. A strong association between coffee consumption and pancreatic cancer was evident in both sexes. The association was not affected by controlling for cigarette use. For the sexes combined, there was a significant dose-response relation (P approximately 0.001); after adjustment for cigarette smoking, the relative risk associated with drinking up to two cups of coffee per day was 1.8 (95% confidence limits, 1.0 to 3.0), and that with three or more cups per day was 2.7 (1.6 to 4.7). This association should be evaluated with other data; if it reflects a causal relation between coffee drinking and pancreatic cancer, coffee use might account for a substantial proportion of the cases of this disease in the United States.

Aged↗

Lung cancer and passive smoking.

Fifty-one women with lung cancer and 163 other hospital patients were interviewed regarding the smoking habits of themselves and their husbands. Forty of the lung cancer cases and 149 of the other patients were non-smokers. Among the non-smoking women there was a statistically significant difference between the cancer cases and the other patients with respect to their husbands' smoking habits. Estimates of the relative risk of lung cancer associated with having a husband who smokes were 2.4 for a smoker of less than one pack and 3.4 for women whose husbands smoked more than one pack of cigarettes per day. The limitations of the data are examined; it is evident that further investigation of this issue is warranted.

Aged↗

Coffee and ovarian cancer.

Ninety-two women with common epithelial tumors of the ovary and 105 comparison women admitted for various orthopedic conditions were interviewed regarding demographic, socio-economic and biomedical characteristics, including their use of coffee and tobacco. There was no association between tobacco smoking and ovarian cancer. However a statistically significant trend association was noted between coffee drinking and ovarian cancer (p approximately 0.03). The association could not be explained in terms of any other variable included in the present study. The relative risk for women drinking two or more cups of coffee per day was 2.2 with 95% confidence limits 1.0-4.8. Several descriptive epidemiologic data are compatible with a causal association between coffee and ovarian cancer.

Adult↗

Isolation of Salmonella with the use of 100 ml of the R10 modification of Rappaport's enrichment medium.

One hundred and eighty samples of pork sausages were examined after pre-enrichment in buffered peptone water (P medium), for the presence of salmonellas. From each pre-enrichment four enrichments were made: (1) o.1 ml of P medium was inoculated into 10 ml of Rappaport's medium formula R 10 (R 10/43 degrees C), /2) 1 ml of the P medium was added to 100 ml of R10 broth (R10/100 ml/43 degrees C), (3) 1 ml of P medium was inoculated into 10 ml of Muller-Kauffmann tetrathionate broth (MK medium) prepared in accordance with the International Standards Organization document ISO 3565 (MK/43 degrees C) and (4) 10 ml of P medium were added to 100 ml of MK broth (MK/100 ml/43 degrees C). All the enrichments were incubated at 43 degrees C for 48 h. Forty-six and 47 samples were found positive with the first two enrichment methods (R10/43 degrees C and R10/100 ml/43 degrees C), while only 16 samples were found positive with the method MK/43 degrees C, and 27 with the methods MK/100ml/43 degrees C. The superiority of either one of the two R10 procedures over either one of the two MK methods is statistically highly significant (paired Chi2; P less than 0.001 in all four comparisons). The superiority of procedures MK/100 ml/43 degrees C over the method MK/43 degrees C is also statistically significant (P less than 0.005). Both R10/43 degrees C and R10/100 ml/43 degrees C procedures had a much stronger inhibitory effect on the competing organisms (lactose- and sucrose negative) than the two MK methods.

Animals↗

Improved isolation of Salmonellae from naturally contaminated meat products by using Rappaport-Vassiliadis enrichment broth.

A total of 454 specimens of meat products were examined for salmonellae by using five procedures of enrichment. The use of a selective motility medium, inoculated from enrichment in Muller-Kauffmann broth, resulted in an increase in the number of positive specimens. However, simple enrichment in Rappaport-Vassiliadis broth, after preenrichment, was more sensitive and specific for recovering salmonellae than the selective motility medium-Muller-Kauffmann broth method.

Animals↗