Biomedical subjects
M O'Brien
Publications and source records attributed to M O'Brien.
Market research into part time training: consumers' views and regional variations.
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Career structure--the modern doctors' dilemma.
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Monocytic differentiation induced by 1,25 dihydroxyvitamin D3 in myeloid cells: an ultrastructural immunocytochemical study.
We have studied, by ultrastructural morphology and immunocytochemistry, the alterations that occur in cells from the HL60 leukaemia cell line and from patients with CGL following incubation in vitro with 1,25(OH)2D3 for 2-5 days. The main morphological changes observed were in the nuclear shape, the development of autophagic vacuoles and the appearance of a population of small granules in the cytoplasm. These changes were associated with a significant reduction in MPO activity and increased expression of membrane antigens detected by the monocyte-specific McAb FMC17 and FMC32, as shown by the IGM at EM level, and a decrease in granulocyte-specific antigens demonstrated by the McAb FMC10. These observations suggest that promyelocytes and myelocytes could transform into monocyte-like cells and that this remodelling of cells was associated with autophagic digestion of cellular structures.
Undergraduate attitudes to exposure to an NHS resource allocation problem.
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Activity level and sex-stereotyped toy choice in toddler boys and girls.
In the first study, the motor activity level and vigor of play of 52 toddlers was assessed as they played with a set of sex-role stereotyped and neutral toys. Boys and girls showed the same level of activity, and both were significantly more active when playing with stereotypically masculine toys. In the second study, 27 toddlers were observed playing with toys defined as potentially eliciting high, medium, or low activity within the masculine, feminine, and neutral categories. Again, boys and girls did not differ in overall activity level. All children preferred toys that allowed moderate to high activity, but given this preference, they selected toys stereotyped for their own gender above those stereotyped for the other gender.
Blast crisis of chronic granulocytic leukemia with mast cell and basophilic precursors.
The authors report a patient with Ph1-positive chronic granulocytic leukemia (CGL) who developed "blast crisis" after six years of chronic phase. The presence of mast cell precursors and basophil blasts was demonstrated by ultrastructural morphology and cytochemistry. Membrane phenotype studies with monoclonal antibodies helped in the further characterization of these cells. The possible implication of these findings in the origin of mast cells and the relationship of these cells with basophils are discussed.
A regional manpower plan for community medicine.
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Characterization of blast cells in chronic granulocytic leukaemia in transformation, acute myelofibrosis and undifferentiated leukaemia. I. Ultrastructural morphology and cytochemistry.
A systematic analysis of the blast cell population was carried out on samples from 50 patients suffering from blast transformation of chronic granulocytic leukaemia (CGL) (31) and of myelofibrosis (4), acute myelofibrosis (AM) (11) and undifferentiated acute leukaemia (4). Transmission electron microscopy (TEM), used in 41 samples, included: morphology and techniques for myeloperoxidase (MPO), platelet-peroxidase (PPO) and acid phosphatase (AP). The majority of cases were also studied by light microscopy cytochemistry and with a battery of cell markers which are reported in the accompanying paper (San Miguel et al, 1985). The characterization of the type(s) of proliferating blasts was made from the integration of ultrastructural and immunological data. TEM morphology allowed the precise recognition of specific granules in basophil and mast-cell precursors and of ferritin particles in blasts of erythroid lineage; these rare cell types were not adequately characterized by other methods. The PPO reaction made possible the identification of pure megakaryoblastic proliferations in 38% of cases, including eight of the 11 with AM; megakaryoblasts were also present in nine of 12 cases with mixed blast cell types. The MPO and AP reactions were useful for the characterization of myeloblasts and monoblasts, respectively. Lymphoblasts could be distinguished from other cell types by TEM morphology and negative MPO and PPO reactions. TEM techniques were valuable for diagnosing correctly the type of blast cell in this study in which only four cases (8%) remained unclassifiable.
Osteolytic lesion as the presenting feature of chronic granulocytic leukaemia.
We describe a woman in whom the first manifestation of chronic granulocytic leukaemia (CGL) was an osteolytic lesion. Six months later the peripheral blood showed the picture of CGL in blast crisis. Chromosome studies confirmed the diagnosis and immunological and ultrastructural studies demonstrated the presence of two blast populations: basophil blasts and megakaryoblasts.
Modified taurocholate-tellurite-gelatin agar for improved differentiation of Vibrio species.
A total of 78 strains, representing 21 Vibrio species, were examined by using taurocholate-tellurite-gelatin agar (TTGA) medium and modified TTGA medium containing 4-methylumbelliferyl-beta-D-galactoside (150 micrograms/ml). Modified TTGA medium allowed for simple and direct detection of beta-D-galactosidase (beta-gal) activity. This feature, in conjunction with other differential characteristics of TTGA medium, gave improved differentiation of the vibrios tested. The modified TTGA medium allowed for easy differentiation of Vibrio cholerae (beta-gal+) from Vibrio parahaemolyticus (beta-gal-). The 4-methylumbelliferyl-beta-D-galactoside substrate is inexpensive and very stable. Incorporation into the agar did not affect the performance of TTGA as a differential medium. The assay for beta-gal activity with this substrate was specific and sensitive.
Psychological, nutritional and physical status of olympic road cyclists.
Six members of the Irish Olympic Road Cycling Squad underwent a comprehensive medical, nutritional, psychological and biochemical assessment in January 1983. They were given specific medical and dietary recommendations and were reassessed in January 1984 after a period spanning the competitive racing season. The cyclists' diets at both sessions were comparable and generally conformed with recommended daily intakes. Supplementary ingestion was unnecessary to attain recommended daily intakes of vitamins. Serum levels of HDL-cholesterol increased and triglyceride decreased during the period of the study. The squad had characteristics indicating traits of self-sufficiency, toughness and practical mindedness. At the second assessment there was evidence of heightened ambition and competitiveness and an improvement in mood states with reduced ratings for confusion and tension.
Women and sport.
Changes in law and the greater emphasis on the benefits of exercise have led to a greater participation of women in sport at all levels. There are anatomical and physiological differences between males and females which give the male athletes advantages in sports which involve jumping and striding. There are fewer differences between male and female athletes from the same sport and with the same level of fitness than there are between fit and unfit females. Unfit women are less tolerant of exercise in a hot environment than fit women with a high aerobic capacity. The calorific requirements for women are more liable to be inadequate due to their dietary habits. Iron and folate metabolism in female athletes may be affected by several factors, such as increased demands and reduced absorption. Athletes, with the exception of swimmers, tend to have a later menarche than normal. Whether this is due to natural selection, body type, percent body fat, stress or abnormalities of the hypothalamic pituitary axis, still has to be determined. Menstrual disturbances in athletes are common in elite distance runners, who, as a group, tend to display distinct training profiles. Psychological factors and stress also play a part. In some athletes the effects of training and competition on the body composition and the hormones that initiate and control menstruation are varied, complex and not fully understood. Women tend to develop the same injuries as men under similar circumstances, causes being training errors, anatomical factors and so on. The incidence of injury is related to the level of fitness and conditioning as well as to the particular sport.
Management of Alzheimer's disease.
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Insect prothoracicotropic hormone: evidence for two molecular forms.
In an insect, the tobacco hornworm Manduca sexta, the cerebral neuropeptide prothoracicotropic hormone (PTTH), the primary effector of postembryonic development, exists as two molecular forms. These two PTTH's elicit characteristic in vitro dose responses of activation of prothoracic glands from different developmental stages, an indication that during development the glands change in their sensitivity to the neurohormones. Both PTTH's are active in a specific in situ bioassay. Since they may be released in situ at stage-specific times to evoke distinctly different developmental responses, the PTTH neuroendocrine axis appears to be an effective system for determining the functions of molecular forms of a neurohormone in the regulation of growth and development.
Sympathetic activity in benign familial tremor.
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Small bowel exclusion from the pelvis by a polyglycolic acid mesh sling.
Radiation enteritis is seen in patients receiving radiation therapy for various pelvic malignancies. Attempts to prevent this have included various surgical as well as nutritional approaches with little success. The use of a polyglycolic acid mesh sling sewn above the pelvic inlet has prevented small bowel descent into the true pelvis in rats and in humans. The technique has been successful in both with no attendant morbidity during an 11-month follow up. Several patients have received additional doses of radiation therapy that would not have been given if the small bowel were not removed from the area to be irradiated.