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Biomedical subjects

A Singer

Publications and source records attributed to A Singer.

At least 379 records · Page 21Linked to original sources
PubMed1976

Causes of cervical carcinoma: new ideas.

There are many features of cervical cancer that distinguish it from other common human cancers. It is extraordinarily sensitive to environmental variation, thus coming under early notice by the epidemiologists. Its accessibility and the introduction of aids to visualization, such as the colposcope, have enabled us to combine the methods of epidemiology and molecular biology in studying disease. This combination may well untangle one of the more serious conceptual problems in contemporary biology - the real nature of the carcinogenic process and all this in man himself.

Adolescent↗
PubMed1975

Cellular immunity to human basic myelin protein in women with dysplasia and carcinoma in situ of the cervix.

Sensitization to human myelin basic protein or encephalitogenic factor (EF), and antigen thought to be analogous to different human tumours, can be measured by the macrophage migration inhibition test (MMI). The MMI test was done on one occasion in 51 women with dysplasia and carcinoma in situ of the cervix; 20 women with non-malignant gynaecological conditions served as controls. Sensitization to EF was found in 71 per cent of women with carcinoma in situ and 42 per cent of women with dysplasia. None of the controls showed sensitization. Sensitization could not be related to histological evidence for cellular infiltration within the cervix.

Adult↗
PubMed1975

The uterine cervix from adolescence to the menopause.

During adolescence the physiological transformation zone of the cervix in the virgin undergoes limited change when compared to that of girls who are sexually promiscuous; the latter often show large areas of metaplastic squamous epithelium and the development of an atypical transformation zone. During pregnancy, particularly the first, the transformation zone increases in size and acquires increased amounts of squamous metaplastic epithelium, probably due to the effect of acidic vaginal fluid on endocervical columnar epithelium. Evidence exists for the development of an atypical transformation zone during pregnancy with its own variable neoplastic potential. After delivery the atypical epithelium of the cervix may be partly or completely removed with resulting regression of the lesion. Alternatively, neoplastic potential may alter or the lesion may remain static or recur in its previous form. After the childbearing era the physiological transformation zone undergoes minimal change until the menopause when the whole cervix shrinks. As the studies described above dramatically show, the sexually promiscuous woman at all ages has an increased risk of developing cervical neoplasia; this risk seems to be the highest in the third decade of life.

Adult↗
PubMed1974

A membrane filter method for correlating colposcopic, histological, and cytological pictures: the application to nuclear DNA measurements.

A method is described for collecting cells on membrane filters in their natural topographical relationships, so that they can be correlated with exact areas in the cervix and with punch biopsy specimens. The same cell sample, after study with Papanicolaou stain, can then be used for other methods without the cells losing their spatial relationships. An example is given of an early cervical carcinoma in which, using a photographic method with a simple type of photometric device, the nuclear DNA was measured from accurately identified normal and neoplastic areas.

Biopsy↗
PubMed1972

Plasma steroid and luteinizing hormone levels during prostaglandin F 2 administration in luteal phase of menstrual cycle.

An intravenous infusion of prostaglandin F(2)alpha (12.5-250mug/min) was administered in four volunteers in the mid-late luteal phase and three in the early luteal phase of the menstrual cycle.Frequent measurement of plasma progesterone, oestrogens, and luteinizing hormone (LH) showed that administration of high doses depressed plasma progesterone levels in the late luteal phase and caused concomitant side effects. Levels of progesterone in the early luteal phase were unaffected. In both phases oestrogen and LH levels were little altered. In two subjects, hourly progesterone levels measured throughout the day at a similar time in a subsequent control menstrual cycle showed an appreciable variation in one but steady levels in the second. This variation may contribute to the magnitude of the fall in progesterone noted during the infusion of prostaglandins.

Adolescent↗