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Biomedical subjects

Russell Keenan

Publications and source records attributed to Russell Keenan.

3 recordsLinked to original sources

Factor X deficiency presenting as a pseudotumor. Case report.

The authors report their experience in successfully treating a 15-week-old child who became comatose following a spontaneous intracerebral hemorrhage. It was initially believed that a tumor in the right frontal lobe caused the hemorrhage. Coagulation studies revealed abnormal results on presentation, and the problem was only partially corrected after an infusion of fresh frozen plasma. The child underwent an emergency craniotomy in which the hematoma was evacuated, and a biopsy specimen was obtained from a firm mass at the base of the hematoma cavity. Postoperatively, the child recovered completely, and an analysis of detailed coagulation studies revealed that the child had a factor X deficiency. Histological analysis of the biopsy specimen revealed normal brain tissue with hemorrhagic infiltration. Subsequently, the child achieved normal developmental milestones. A diagnosis of congenital bleeding disorder should be considered in children with spontaneous intracerebral hemorrhage, even in those with no prior episode of extracerebral spontaneous hemorrhage.

Brain Neoplasms↗

Comparative analysis of CD8+ T cell responses against human cytomegalovirus proteins pp65 and immediate early 1 shows similarities in precursor frequency, oligoclonality, and phenotype.

CD8+ T cells are key effectors of the immune response against human cytomegalovirus (HCMV). A number of HCMV-derived CD8+ T cell epitopes are known. Using epitope prediction and subsequent testing for interferon-gamma responses by the ELISPOT assay, we identified an optimal human leukocyte antigen (HLA)-A*0201-restricted CD8+ T cell epitope derived from the major immediate early 1 (IE-1) gene product. As many as one-third of HLA-A*0201-positive, HCMV-seropositive donors make responses to this peptide (residues 316-324 [VLEETSVML]), which can exceed responses against a published immunodominant pp65 epitope (residues 495-503 [NLVPMVATV]). Major histocompatibility complex peptide tetramer staining facilitated detailed phenotypic analyses and revealed populations that resemble terminally differentiated effector cells (CD57+ and CD28-), with considerable restriction in T cell receptor beta-chain variable region use. The results confirm that, although pp65 is a major target for CD8+ T cells, the IE-1 protein may itself stimulate comparable responses in some persons.

Antigens, Viral↗