High resolution two-dimensional polyacrylamide gel electrophoresis using Immobilines. Application to the study of brain proteins

Cytoplasmic soluble proteins of unknown origin but which could be associated with the development and maturation of the central nervous system are recognized by antibodies found in serum of patients with a paraneoplastic neurological syndrome. The associated antigens are of great interest in understanding these neurological pathologies. To study these antigens we describe and criticize a two dimensional polyacrylamide gel electrophoresis (2D-PAGE), using immobilized pH gradient (IPG) in first dimension. Proteins from brain complex mixtures were separated by this technique in order to identify and characterize (molecular weight, p-isoelectric point, sequencing) a protein of interest. Results prove the high reproducibility and the good resolution of the technique. Without applying enrichment method prior to 2D-PAGE, any proteins are not sequenceable after transblotting to PVDF (polyvinylidene difluoride) membrane and Coomassie blue staining. In these cases the meaning to reach the wanted aim, i.e. sequencing, was discussed.

Posterior uveitis, paraneoplastic encephalomyelitis and auto-antibodies reacting with developmental protein of brain and retina

We report a 68-year-old woman who presented with posterior uveitis, cerebellar ataxia, dysautonomia, peripheral neuropathy and undifferentiated carcinoma. Autopsy showed slight brain inflammatory changes and severe Purkinje cell degeneration. By immunocytochemistry, the serum and CSF contained antibodies that reacted with the cytoplasm of cells in the brain and retina of rat. Some neurons and glial cells were stained. However, the most labelled cells were immature cells of the subventricular layers of the dentate gyrus, olfactory bulb and lateral ventricles. In rat retina, the plexiform layers and cells of the inner granular layer were stained. E15 rat embryo showed diffuse staining of post-mitotic cells and process in the central and peripheral nervous system. With the patient's IgG, various bands of 45, 60, 70 and 135 kDa apparent molecular weight were demonstrated on immunoblots of adult human, adult and E15 embryonic rat brain and rat and bovine retina. Eluates of tissue bound IgG labelled the same bands.

Effects of diabetes type and treatment on zinc status in diabetes mellitus

Zinc status was assessed in 53 diabetic patients: 18 insulin-dependent diabetic patients (IDDM), 22 noninsulin-dependent diabetic patients (NIDDM) treated with oral antidiabetic agents, and 13 insulin-treated, noninsulin-dependent diabetic patients (IRDM). Plasma zinc concentrations were in the usual range for healthy subjects in these three groups (15.3 +/- 0.9 mumol/L). Urinary zinc excretions were elevated in the IDDM group (18.3 +/- 4.1 mumol/24 h; p less than 0.01 vs normal) and in the NIDDM group (17.5 +/- 3.5 mumol/24 h; p less than 0.01 vs normal), but normal in the IRDM group (11.3 +/- 2.4 mumol/24 h). In 14 NIDDM patients treated with transient continuous sc insulin injections, urinary zinc decreased from 16.5 +/- 2.2 mumol/24 h before insulin treatment to 11.5 +/- 0.3 mumol/24 h after insulin treatment without any modification in plasma zinc concentrations.