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Biomedical subjects

R McCarron

Publications and source records attributed to R McCarron.

7 recordsLinked to original sources

Chimeric cytotoxin IL2-PE40 inhibits relapsing experimental allergic encephalomyelitis.

IL2-PE40 is a chimeric protein composed of human interleukin-2 (IL2) genetically fused to a modified form of Pseudomonas exotoxin lacking the cell recognition domain. IL2-PE40 is cytotoxic for IL2 receptor-bearing lymphocytes in culture and can inhibit activation of T cells in vivo. IL2-PE40 can significantly diminish antigen-stimulated proliferation of lymphocytes sensitized to myelin basic protein. Intraperitoneal administration of IL2-PE40 not only markedly inhibits the clinical manifestations of adoptively transferred relapsing experimental allergic encephalomyelitis but also dramatically reduces both inflammation and demyelination characteristic of the disease.

Animals

Healing potential of the anulus fibrosus.

The purpose of this study was to investigate the healing of surgically created defects in the anulus fibrosus in an effort to determine the healing potential of this structure. Four identical lesions were made in the anulus fibrosus of ten dogs at levels L2-L5. Two dogs were killed at 3, 6, and 9 weeks. Four dogs were killed at 12 weeks. The spines were harvested during a 3- to 12-week period and evaluated grossly and microscopically. Our study demonstrated that a stab wound of the anulus has a limited healing potential and the persisting defect could provide a pathway for irritating nuclear fluid escape onto perineural tissue, possibly resulting in persistent low-back pain.

Animals

Adoptively transferred experimental autoimmune encephalomyelitis in SJL/J, PL/J, and (SJL/J x PL/J)F1 mice. Influence of I-A haplotype on encephalitogenic epitope of myelin basic protein.

Guinea pig basic protein (GPBP)-immune lymph node cells (LNC) from SJL, PL, and SJL x PL (F1) mice proliferated to whole GPBP and GPBP fragments 1-37, 43-88, and 89-169. All three strains of mice developed experimental allergic encephalomyelitis (EAE) by active immunization with whole GPBP or by passive transfer of LNC cultured with whole GPBP. SJL (H-2s) and PL (H-2u) mice developed EAE by active immunization with fragments 89-169 or 1-37, respectively, or by passive transfer of LNC cultured with the same Ag. F1 mice developed EAE by active immunization only with fragment 1-37 or by passive transfer of LNC cultured with either of the above fragments. Removal of macrophages (MO) from immune-F1 LNC resulted in the loss of a proliferative response and the ability to transfer EAE. Reconstitution of MO-depleted immune F1 T cells with either F1-, SJL-, or PL-MO restored the proliferative responses to whole GPBP and the three fragments. Cultures of immune F1 T cells reconstituted with any of the three MO populations and incubated with whole GPBP passively transferred EAE into naive F1 mice. Immune F1 T cells cultured with F1 MO in the presence of either fragment 1-37 or 89-169 transferred EAE. F1 T cells cultured with SJL MO were able to transfer EAE only if the Ag was fragment 89-169, whereas F1 T cells cultured with PL MO were able to transfer disease only if incubated in the presence of fragment 1-37. F1 mice are passively susceptible to EAE induced by adoptive transfer of cells reactive to either the N-terminal or C-terminal fragment and that the encephalitogenic determinant of GPBP is related to the genome of MO present in vitro.

Animals

Adoptively transferred acute and chronic relapsing autoimmune encephalomyelitis in the PL/J mouse and observations on altered pathology by intercurrent virus infection.

PL/J mice developed chronic relapsing experimental allergic encephalomyelitis (EAE) after receiving syngeneic guinea pig basic protein (GPBP)-immune lymph node cells or spleen cells which were cultured in the presence of GPBP or the encephalitogenic N-terminal peptide of GPBP. The presence of L3T4+ cells and in vitro proliferation in response to GPBP are required for the successful transfer. Pathologically, passively transferred EAE in the virus-free PL/J strain was characterized by an infiltration in the central nervous system by small lymphocytes, followed by the appearance of macrophages, and subsequently by primary demyelination. These findings were similar to those previously observed in chronic relapsing EAE in SJL/J mice. However, in some experiments pathologic examination of the spinal cord showed large demyelinating lesions which were necrotic and infiltrated with eosinophilic polymorphonuclear leukocytes. Sera from mice with this pathology contained antibodies to murine hepatitis virus and extensive search identified a few areas of coronavirus replication. The pathology of autoimmune mediated demyelination may be altered in the presence of coronavirus infection but the clinical pattern of EAE expression did not differ between virus-free and coronavirus-infected mice.

Animals