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Biomedical subjects

K J Carroll

Publications and source records attributed to K J Carroll.

5 recordsLinked to original sources

Cellular and molecular characterization of the role of the flk-2/flt-3 receptor tyrosine kinase in hematopoietic stem cells.

The flk-2/flt-3 receptor tyrosine kinase was cloned from a hematopoietic stem cell population and is considered to play a potential role in the developmental fate of the stem cell. Using antibodies derived against the extracellular domain of the receptor, we show that stem cells from both murine fetal liver and bone marrow can express flk-2/flt-3. However, in both these tissues, there are stem cell populations that do not express the receptor. Cell cycle analysis shows that stem cells that do not express the receptor have a greater percentage of the population in G0 when compared with the flk-2/flt-3-positive population. Development of agonist antibodies to the receptor shows a proliferative role for the receptor in stem cell populations. Stimulation with an agonist antibody gives rise to an expansion of both myeloid and lymphoid cells and this effect is enhanced by the addition of kit ligand. These studies serve to further illustrate the importance of the flk-2/flt-3 receptor in the regulation of the hematopoietic stem cell.

Animals↗

A prospective investigation of the long-term auditory-neurological sequelae associated with bacterial meningitis: a study from Vanuatu.

During the period August 1988-July 1991 all cases of bacterial meningitis admitted to Lenakel Hospital on the island of Tanna in Vanuatu were followed. During this period there were 83 cases of purulent meningitis giving an annual incidence of 134 per 100,000 population. There were 13 deaths during the acute illness phase (CFR = 15.7%). Of the 70 survivors 65 (93%) were successfully followed for a mean duration of 17.5 months. When grouped by severity of illness there was no significant difference in the mean age, duration of symptoms or sex of the patients. At the time of discharge 31.5% had auditory-neurological abnormalities. During follow-up 35% of the survivors were found to have one or more auditory-neurological sequelae. Hearing loss was the most frequent abnormality occurring in 32.2% of the study group. Of those with auditory-neurological sequelae 39% were judged to have severe disabilities likely to impair their ability to live independently. A statistically significant association was found between the severity of the illness at presentation and the risk of auditory-neurological sequelae. Meningitis caused by Streptococcus pneumoniae was associated with the highest incidence of sequelae and that caused by Hemophilus influenzae type b with the lowest. There was no association with sex or age group. Strategies to reduce the mortality and morbidity from bacterial meningitis in developing countries are briefly discussed.

Adolescent↗