William T. Shearer

Purification and immunohistochemical localization of rat brain myelin proteolipid protein.

Abstract— A homogeneous preparation of proteolipid protein (PLP) from rat brain myelin was isolated by preparative gel electrophoresis in sodium dodecyl sulfate and chemically characterized. The results of amino acid and N‐terminal amino acid analyses are reported. The same preparation of myelin PLP was used to produce specific precipitating antibodies. Rabbit and goat antisera to myelin PLP each gave a single precipitin line with purified PLP dissolved in Triton X‐100. Under identical conditions, no precipitation was observed with antiserum to myelin basic protein or with control serum. Immunofluorescence localization employing antiserum to PLP demonstrated bright specific fluorescence restricted to the myelin sheaths of axons in all anatomical areas of the rat brain examined. Neuronal cell bodies and their dendrites were completely negative with respect to the presence of proteolipid protein. PLP could not be localized in the cell bodies or fibrous processes in any of the glial elements in the adult rat brain. However, myelin PLP was clearly visible in the cytoplasm and processes of actively myelinating oligodendrocytes in the corpus callosum in the brains of 10‐day‐old rats.

Stimulation of Cells by Antibody

Tumor cell lines exposed to immunoglobulins specific for cell surface antigens developed increased cellular incorporation of [125I]iododeoxyuridine and [3H]thymidine (up to 200-fold increases over cells treated with normal rabbit immunoglobulins). Antibody-stimulated cells multiplied more rapidly and lived longer than control cells in tissue culture. These observations were made both with cells substituted with 2,4,6-trinitrophenol and purified antibody against 2,4,6-trinitrophenol, and with several cell lines and their respective whole-cell antibodies. Antibodies that were stimulatory at low concentrations were cytotoxic at high concentrations. These observations may have significance in regard to enhancing effects of antibodies on tumor cell growth in vivo.

Urinary retention in a neonate secondary to maternal ingestion of nortriptyline

A newborn child had urinary retention with bladder distention presumably due to maternal ingestion of the antidepressant drug nortriptyline.

Humoral immunostimulation. II. Increased nucleoside incorporation, DNA synthesis, and cell growth in L cells treated with anti-L cell antibody.

Interaction of rabbit antibody to L cell lines caused an intense stimulation of radioactive nucleoside uptake which was maximal 24–72 hr after exposure to antibody. Smaller but parallel increases in DNA synthesis, cell growth rate, and numbers were observed. A marked dose dependency was observed with smaller amounts of antisera being stimulatory and larger doses cytotoxic. The stimulatory antibody was demonstrated to be present in the IgG globulin fraction. The IgG antibody was rapidly cytotoxic to target cells in the presence of fresh exogenous complement. Prolonged trypsinization of L cells reduced the ability of the cells to be stimulated by anti-L antiserum presumably due to removal of membrane antigens.

Coarctation of the aorta and cerebrovascular accident: A proposal for early corrective surgery†

A 9-year-old boy was hospitalized because of an acute onset of right hemiplegia, right homonymous hemianopsia, and aphasia. Diagnostic studies revealed coarctation of the aorta distal to the origin of the left subclavian artery and a cerebrovascular accident involving the left cerebral hemisphere. Repair of isolated coarctation of the aorta at an early age, i.e., 8 years or younger, might possibly prevent cerebrovascular complications and relieve the continued stress upon the left ventricular muscle.