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Biomedical subjects

D S Allen

Publications and source records attributed to D S Allen.

48 records · Page 3Linked to original sources
PubMed1986

Identification of women at high risk of breast cancer.

Prospective studies of risk factors for breast cancer have been carried out since 1961 on a normal population which now comprises some 15,000 women. Classical (anamnestic) factors such as ages at menarche, menopause, or at first child, post-menopausal weight and high parity are not strong determinants of risk. Measurements of various aspects of endocrine function are more successful in identifying women at risk, as is assessment of mammographic parenchymal patterns but, again, these variables are not effective enough to make an intervention strategy imperative. However, the combination of classical, endocrinological, and radiological factors appears to achieve this aim. A substantial sub-set of women who have a four-fold risk of breast cancer may be identifiable.

Adult↗
PubMed1985

Influence of reproductive history on age at diagnosis of breast cancer and prognosis.

The effect on age at breast cancer diagnosis of age at menarche, age at first baby, parity and age at menopause has been determined for 739 unselected patients diagnosed between 1975 and 1980 as having operable breast cancer. Age at diagnosis was significantly and positively associated with ages at menarche, first baby and menopause. The average number of children significantly declined with increasing age at diagnosis. This was largely due to a change in the proportion of patients who were nulliparous (15% in women aged 41-50 years compared to about 30% in those over 60 years). A group of 1,989 normal women whose reproductive history was also collected between 1975 and 1980 showed similar trends between age and age at menarche, age at first baby and parity as the patients. Thus it appears that these reproductive parameters do not alter the time of onset of breast cancer but could be explained by temporal changes in reproductive patterns. There was no significant correlation between age at menopause and age at diagnosis for patients whose age at menopause was no more than 54 years and age at diagnosis no less than 55 years, respectively. It is therefore unlikely that age at menopause affects age at diagnosis. Postmenopausal patients with 3 or more children had a significantly shorter disease-free interval and lower survival rate than those with less children. None of the other parameters was associated with prognosis.

Adult↗
PubMed1985

Positive symptoms and the organization within and between ideas in schizophrenic speech.

The study examined the performance of positive symptom schizophrenics vis à vis that of demographically well-matched negative symptom schizophrenics and normals in organizing words into ideas and ideas into integrated spoken discourse. This involved applying a series of analyses to speech produced when describing pictures in an unconstrained way. The results showed that, for the most part, positive symptom schizophrenics organized their speech, both within and between ideas, as well as negative symptom schizophrenics and normals. The results did, however, show an increased tendency by the positive speech disordered schizophrenics to omit referents for noun phrases requiring referents. This constitutes a specific failure to connect ideas and does, at least in part, explain what makes positive speech disorder (incoherence of speech) unintelligible. However, taken altogether, the results do not support the extant view that positive symptom schizophrenics suffer from a general loss of control in producing speech.

Adult↗
PubMedDate not supplied

Pregnancy and menstrual hormone levels in mothers of twins compared to mothers of singletons.

This study examined the hormonal differences between premenopausal mothers of twins and other premenopausal parous women during and after pregnancy. Serum concentrations of oestradiol and testosterone between 6 and 20 weeks of gestation were measured for 11 mothers of twins and 115 mothers of singletons selected from the controls in a case-control study of cryptorchidism. Serum concentrations of oestradiol, progesterone, testosterone, follicle stimulating hormone and sex hormone-binding globulin during the menstrual cycle were measured for 25 mothers of twins and 38 mothers of singletons recruited as a part of a prospective study of breast cancer risk. During pregnancy, women carrying twins had a 58% higher geometric mean oestradiol concentration (p = 0.02) and a 50% higher testosterone concentration (p = 0.03) than women carrying singletons. Women who had previously had twins demonstrated a 49% higher mean concentration of follicle stimulating hormone (p = 0.02) and a 42% higher concentration of sex hormone-binding globulin (p = 0.03) than women who had singletons only, but no significant differences in oestradiol, progesterone and testosterone concentrations. The increased concentrations of follicle stimulating hormone during the menstrual cycle of mothers of twins, which has also been reported in two previous studies suggests that follicle stimulating hormone level may be an important determinant of dizygotic twinning.

Case-Control Studies↗
PubMedDate not supplied

Sex-hormone-binding globulin and breast cancer risk.

We have measured serum concentrations of SHBG in 5000 women over the age of 35. In both premenopausal and postmenopausal women who were not suffering from cancer or other diseases or taking drugs likely to affect SHBG, the protein decreased with increasing weight and was lower in single nulliparous women than in married nulliparous women or parous women. In premenopausal women, SHBG was higher in women with late menarche. These findings suggest that diminished SHBG concentrations may be associated with the increased risk for breast cancer conferred by nulliparity and early menarche.

Breast Neoplasms↗