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Biomedical subjects

F O'Sullivan

Publications and source records attributed to F O'Sullivan.

29 records · Page 2Linked to original sources
PubMed1992

Amaurosis fugax in young people.

Nine young adults (median age 19.5 years) who suffered from amaurosis fugax (AF) are described. The attacks of AF were short in duration and preceded by premonitory symptoms in five cases and by a migrainous headache in two. In five patients the visual loss progressed in a lacunar pattern unlike the 'curtain' pattern characteristic of AF in older patients. Investigation revealed no evidence of an embolic or atheromatous aetiology. In two cases a minor abnormality was found on echocardiography. We conclude that AF in young adults has a different clinical pattern and may have a different aetiology, possibly migrainous, compared with that seen in older patients. The pattern of visual loss in some of the cases suggests that the choroidal circulation rather than the retinal circulation is primarily affected.

Adolescent↗
PubMed1992

The pattern electroretinogram in glaucoma and ocular hypertension.

Thirty one eyes with established glaucoma, 61 high risk ocular hypertensive (OHTs) eyes, 66 medium risk OHT eyes, 58 low risk OHT eyes, and 47 control eyes have been followed for up to 2 years by clinical examination and pattern electroretinography (PERG). The study was 'masked' so electrophysiological and clinical data were kept separate. Criteria have been devised which enable PERG measurements to distinguish all established glaucomatous eyes from all normal controls; these criteria demonstrate abnormalities in some OHT eyes, particularly those at high risk. The PERG abnormality is greatest in eyes with established glaucoma in which the intraocular pressure has been lowered by treatment. The PERG becomes smaller as the degree of clinical abnormality increases. Test-retest variability of the PERG is sufficiently low to ensure that most of those first described as abnormal continue to be so.

Adult↗
PubMed1991

Macular colour contrast sensitivity in ocular hypertension and glaucoma: evidence for two types of defect.

Colour contrast sensitivity (CCS) of a large cohort of glaucomatous patients, ocular hypertensive patients (OH), and normal persons was measured at six-month intervals during a two-year period. The OHs were graded into high, medium, and low risk groups. 69% of glaucomatous patients and 32% of all OHs had CCS thresholds greater than the mean plus 2 SDs of the controls. Satisfactory specificity and sensitivity could not be obtained by adjusting the criterion of threshold. In abnormal eyes, progressive small increases of threshold occurred during the study, but glaucomatous eyes with normal thresholds on the first visit retained normal thresholds in the subsequent visits. Although our system is very sensitive and precise, the proportion of abnormalities detected is no greater than with other techniques. In some glaucomatous patients there is a true preservation of colour vision which does not merely reflect the limitations of the test employed.

Color Perception↗
PubMed1988

Deconvolution of episodic hormone data: an analysis of the role of season on the onset of puberty in cows.

A new approach to the analysis of episodic hormone data is described. The method involves a stochastic model in which measured blood hormone concentration is represented as a convolution of individual pulses, each of which is thought of as the response to a burst of neural activity. Individual pulses are not constrained to occur in a fixed regular pattern in time. The methodology takes a series of blood hormone measurements and produces a spike train of pulse peak times together with a set of pulse shape parameters. This decomposition motivates some fresh approaches to the analysis of hormone data. For a given number of pulses the model is fit by minimizing a residual sum of squares criterion. This is a difficult combinatorial optimization problem. A randomized local adjustment algorithm is developed. Generalized cross-validation is used to select the number of pulses. The technique seems to produce reliable results on simulated data sets. The methodology is used to study some data concerned with the role of season of birth on the onset of puberty in bovine females. The analysis raises some interesting questions related to the maturation of the pituitary and hypothalamus.

Algorithms↗
PubMed1983

CEA-like material in cytosols from human breast carcinomas. Correlation with biochemical and pathologic parameters.

CEA-like material was found in 51 of 62 primary human breast carcinomas and in only 2 of 12 fibroadenomas. Levels of carcinoma CEA-like material correlated weakly with cytoplasmic estradiol receptor levels, total cytosol estrogens, and cytosol progesterone. Levels of CEA-like material showed no significant correlation with carcinoma stage, grade, cellularity, size or histologic type. Levels, however, correlated inversely with lymphocyte infiltration.

Adenofibroma↗
PubMed1978

Transformation of human embryo cells with the use of cell-free extracts of a human rhabdomyosarcoma cell line (HUS-2): brief communication.

Cell-free extracts of the human rhabdomyosarcoma cell line HUS-2 caused the transformation of human embryo fibroblasts. This transformation included morphologic alteration, karyotypic change, and an increase in culture longevity. With the use of sex markers, multiple karyotypes confirmed that the human embryo fibroblasts were transformed, and the use of cell-free material further suggested the presence of a transforming virus. RNA-dependent DNA polymerase activity in a particle with a specific gravity of 1.16 g/cm3 indicated the presence of an RNA type C virus. Evidence also suggested that the known mammalian type C viruses, routine cytopathic effect-inducing viruses, or mycoplasma were not the agents responsible for the transformation. That both the donor (HUS-2) and converted (HUE-T) cell lines cross-reacted with antisera prepared against HUE-T indicated a common antigen arising in the process of conversion of HUS-2 cells to HUE-T cells.

Animals↗
PubMedDate not supplied

CEA and CA 15-3 in primary and recurrent breast cancer.

To evaluate CA 15-3, a new breast cancer associated antigen, and to compare it with carcinoembryonic antigen (CEA), all patients presenting with breast cancer had preoperative and serial (3-monthly) postoperative levels measured. Of 124 patients with primary breast cancer, 23% had an elevated CA 15-3 (greater than 25 units/ml) while 11% had an elevated CEA (greater than 5 ng/ml) (p = not significant). Neither marker was an indicator of spread to regional lymph nodes in primary breast cancer. In 45 recurrences of breast cancer, CA 15-3 was elevated at the time of first recurrence in 58% while CEA was elevated in 47% (p = not significant). Of 17 patients with locoregional recurrence alone, none had a CA 15-3 above 40 units/ml while 11 of 12 with synchronous locoregional and distant recurrence had a CA 15-3 level greater than 40 units/ml (chi 2: 21.36, p less than 0.0001). This study shows that CA 15-3, like CEA, is of little clinical value in primary breast cancer. CA 15-3, however, is an accurate indicator (overall accuracy, 97%) of synchronous distant metastases in patients with locoregional recurrence from breast cancer. This information has important implications for further investigation and management of such patients.

Antigens, Tumor-Associated, Carbohydrate↗