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Biomedical subjects

A Choy

Publications and source records attributed to A Choy.

16 recordsLinked to original sources
PubMed1999

Pedophiles: mental retardation, maternal age, and sexual orientation.

Intellectual functioning, parental age, and sexual orientation in 991 male sexual offenders were investigated. Sources of data included semistructured interviews, clinical charts, phallometric tests, and self-administered questionnaires. The results suggest two main conclusions: (i) Among pedophiles in general, erotic preference moves away from adult women along two dimensions: age and sex. The extent of this movement is greater, along both dimensions, for pedophiles with lower levels of intellectual functioning. (ii) High maternal age (or some factor it represents) increases the likelihood of exclusive sexual interest in boys. Intellectual deficiency (or some factor it represents) decreases the likelihood of exclusive sexual interest in girls. These two factors summate, so that a pedophile with both factors is more likely to be sexually interested in boys than a pedophile with only one.

Adult↗
PubMed1996

Induction of tumour cell shedding into effluent venous blood breast cancer surgery.

Surgeons have long been concerned that cancer may be disseminated by shedding of tumour cells into the bloodstream during surgery. Early claims that cancer operations induced an increase in the number of tumour cells shed into the circulation were subsequently discredited, and the issue has remained unresolved. We used immunocytochemistry for cytokeratins to detect tumour cells in effluent blood from breast carcinomas in 18 patients undergoing surgery. Tumour cells were detectable in 6/18 patients during surgery, in only one patient before operation and in none post-operatively (P = 0.025). Circulating cells were associated with vascular invasion within the primary tumour (P = 0.032). No cytokeratin-positive cells were found in blood from ten normal volunteers or four patients undergoing surgery for other breast conditions. These results confirm that cancer surgery in humans results in an increase in the shedding of tumour cells into the circulation. The implications for prognosis and practice should be determined by larger prospective studies.

Breast Neoplasms↗
PubMed1995

Association between tumour angiogenesis and tumour cell shedding into effluent venous blood during breast cancer surgery.

Tumour angiogenesis is a powerful prognostic indicator in breast cancer. Shedding of tumour cells into the bloodstream is essential for haematogenous metastasis. The relation between cell shedding and angiogenesis in human cancer is not known. We studied vascular density and cell shedding in 16 women undergoing breast cancer surgery. Circulating cells were found in one patient before, in six during, and none after operation. Vascular density was related to detection of circulating tumour cells during surgery (correlation coefficient for first intraoperative sampling = 0.56, p = 0.024, 95% CI 0.08 to 0.83). Tumour cell shedding during surgery is related to vascular density; the relevance of this relation to the prognostic significance of vascular density in breast cancer merits further study.

Breast Neoplasms↗
PubMed1994

Streptokinase inhibits pulmonary tumor seeding in an animal experimental model.

One aspect of the metastatic process involves entrapment of tumor cells within the microcirculation of organs in a "fibrin-platelet mesh." We postulate that destruction of this mesh by fibrinolysis might discourage tumor seeding, thereby inhibiting metastasis. To study this hypothesis, the effect of intravenous streptokinase on pulmonary tumor seeding was examined in a rodent model. In vitro experiments demonstrated that streptokinase had no cytotoxic or cytostatic effect on the Mtln3 cell line. Pharmacokinetic studies showed that at 30,000 U/kg, streptokinase caused systemic fibrinolysis in the Fischer rat, as demonstrated by the thrombin time and fibrin plate lysis assay. Streptokinase administered at this dose, 30 min after tumor cell injection, caused a significant decrease in pulmonary tumor seeding (median 23.0 in the streptokinase-treated group vs. 67.5 in untreated controls, P < 0.0001, Mann-Whitney U-test). Analysis of fibrin degradation products in the streptokinase-treated group suggested that this effect might be secondary to fibrinolysis. The implications of these findings are discussed.

Adenocarcinoma↗
PubMed1977

Oculocutaneous albinism associated with Apert's syndrome.

Five of nine patients with Apert's syndrome (acrocephalosyndactyly) showed an associated hypopigmentation of hair, skin, and eyes. The hair color of these five patients ranged from light brown to blond, the skin was pale, and the irides hazel or blue. Iris transillumination and hypopigmentation of the fundus were present and associated with absent or diffuse foveal reflexes. Unlike most forms of classic oculocutaneous albinism, however, there was good visual acuity and no pendular nystagmus. The evidence indicated that the lack of pigmentation associated with the characteristic skeletal anomalies of Apert's syndrome resulted from a disturbance of independent, genetically related, processes occurring at a common point in gestation.

Acrocephalosyndactylia↗
PubMed1976

Congenital ophthalmoplegia in oculoauriculovertebral dysplasia-hemifacial microsomia (Goldenhar-Gorlin syndrome). A clinicopathologic study and review of the literature.

Two patients with Goldenhar-Gorlin syndrome showed paralysis of one or more extraocular eye movements on neurologic examination. At autopsy, a third patient showed unilateral agenesis of trochlear and abducens nerves and corresponding brain stem nuclei. Congenital ophthalmoplegia is not infrequent in Goldenhar-Gorlin syndrome and may be due to hypoplasia or agenesis, or both, of extraocular muscles, extraocular nerves, and brain stem nuclei.

Abducens Nerve↗