Failure of serum from recovered rats to prevent enhanced adoptive transfer of experimental allergic encephalomyelitis

The rat is unique among species used for research on experimental allergic encephalomyelitis (EAE) because of the spontaneous recovery which occurs routinely after severe, almost fatal disease. The mechanism of recovery has never been adequately explained although it has been suggested that suppressor cells might play a role in this phenomenon. In another immune system (contact sensitivity) anti-idiotypic antibodies obtained during the recovery phase have been shown to have a protective effect. Adoptive transfer of EAE, which can be markedly enhanced by incubation of sensitized cells with antigen in vitro, offers a convenient tool for investigating mechanisms of recovery. With this system, we have attempted to suppress transfer of disease with serum obtained from recovered rats. In spite of various manipulations of the experimental protocol, including the use of serum plus complement before and after incubation of cells with antigen, we have been unable to demonstrate suppression of disease. We and others recently reported that cells from recovered rats are also capable of enhanced transfer. This permitted the use of autologous serum from individual cell donors. Even in this strictly autologous system, however, no inhibitory effect of serum could be detected.     

A comparison of demyelinating and myelination-inhibiting factor induction by whole peripheral nerve tissue and P2 protein

Sera from rabbits sensitized with whole bovine spinal roots demyelinated and inhibited myelination in both peripheral and central nervous system tissue cultures. Antisera directed against the peripheral nerve myelin basic protein, P₂, demonstrated no antimyelin activity in vitro. These results suggest that demyelinating and myelination-inhibiting factors are directed against some peripheral nerve component(s) other than the P₂ protein.     

Effect of dietary fiber on copper, zinc, and magnesium utilization by adolescent boys.

The effect of three dietary fibers on zinc, copper, and magnesium utilization by adolescent boys was studied. The 21-day study was divided into a 2-day introductory nitrogen depletion period, a 3-day adjustment period, and a four 4-day randomly arranged experimental period. During the four experimental periods, the eight adolescent male subjects received a basal diet plus 14.2 g supplements of cellulose, hemicellulose, or pectin. All subjects received all experimental diets. Zinc, copper, and magnesium contents of food, urine and blood serum were measured by atomic absorption spectrophotometry. Relatively small changes in urinary excretion or in blood serum contents of these minerals were found that could be attributed to dietary fiber supplementation. Statistically significant changes in fecal mineral loss were demonstrated. While receiving the basal diet alone or plus hemicellulose, cellulose, or pectin, mean fecal zinc contents (milligrams per subject per day) were 9.64, 13.32, 10.26, and 9.63, respectively; mean fecal copper contents (milligrams per subject per day) were 3.78, 5.04, 4.07, and 3.91, respectively; and mean fecal magnesium contents (milligrams per subject per day) were 303.71, 379.20, 325.69, and 278.48, respectively.     

Trace polypeptides in cellular extracts and human body fluids detected by two-dimensional electrophoresis and a highly sensitive silver stain.

Development of a highly sensitive silver stain permits the characterization of trace cellular and body fluid proteins separated by the two-dimensional electrophoresis technique of O'Farrell. Many of the proteins detected by the silver stain in urine, spinal fluid, amniotic fluid, and cells were undetected with the widely used Coomassie blue stain. Trace polypeptides observed in Escherichia coli cell lysates with this silver stain could be detected previously only by growth in radioactive precursors followed by lengthy autoradiography. In situations that do not permit the use of radioactive labeling, as in human clinical studies, the enhanced ability to detect proteins achieved by the silver stain will facilitate metabolic studies and the screening for protein abnormalities in mutational studies and in genetic diseases.     

Radionuclide scans in staging of carcinoma of the lung

Radionuclide scans are relatively accurate, non-invasive, diagnostic tools when used in patients with carcinoma of the lung with clinically suspected metastases. Their role as a screening or staging procedure in patients without signs or symptoms of metastases is less clear. Brain scans in asymptomatic patients have a low yield. Liver scans done in the absence of hepatomegaly or elevated liver function tests show a high per cent of false-negative and negative results. Bone scans appear to be of considerable value in patients with or without clinical evidence of metastases, in spite of limitations imposed by frequent false-positive results.