Tumor-Associated Antibodies in the Serum of Patients with Ocular Melanoma: IV. Correction for Smooth Muscle Antibodies

Serum samples from patients with choroidal malignant melanoma, carcinoma metastatic to the choroid and “normal” controls containing tumor-associated antibodies (TAA) to tissue cultured melanoma cells were examined for the presence of smooth muscle antibody (SMA). Sera found to contain SMA were absorbed with actin or thrombosthenin and reassayed for TAX With this modification, 72% (78% before absorption) of patients with uveal melanoma, 26% (78% before absorption) of patients with carcinoma metastatic to the choroid and 13% (24% before absorption) of “normal” controls were found to have tumor-associated antibodies in their serum.     

S-antigen in the developing retina and pineal gland: a monoclonal antibody study

Spleen cells of BALB/c mice, previously immunized with bovine retinal S-antigen, were fused with Sp2/0-Ag14 mouse myeloma cells. Two monoclonal antibodies (MAbs) MAbA9-C6 (IgG2a isotype) and MAbA1-G5 (IgG1 isotype) were selected on the basis of reactivity in an ELISA and immunofluorescent assay. In radioimmunoassay MAbA9-C6 and MAbA1-G5 do not compete and appear to define unrelated epitopes of S-antigen. Both MAbs reacted in the ELISA assay, whereas only MAbA9-C6 bound to S-antigen in fixed tissue sections. Because MAbA9-C6 was useful for immunocytochemistry, it was studied in more detail. MAbA9-C6 bound to all vertebrate retinas tested including human, bovine, guinea pig, and mice. The immunoreactivity of MAbA9-C6 also was studied in the developing rat retina and pineal gland. In the morphologically undifferentiated retina, assessed by conventional light microscopy, there was an incomplete separation of the outer neuroblastic cells. However, in the same retina a distinct zone, corresponding to S-antigen immunoreactivity, was present indicating antigenic differentiation with regard to S-antigen at this stage of retinal development. In the pineal gland, S-antigen immunoreactivity was first observed in the three day old rat and at all stages examined thereafter. The usefulness of these two MAbs in the study of the embryologic development of the retina and of the antigenic epitopes of S-antigen is discussed.     

Dimethylsulfoxide action on fast axoplasmic transport and ultrastructure of vagal axons.

The axonal microtubules (MT) are believed to be involved in fast axonal transport (FAXT). Dimethylsulfoxide (DMSO) has a strong stabilizing action on MT in vitro which may account for some of its reported biological effects. DMSO at concentrations of 5% disrupts the FAXT in a high percentage of axons emanating from the nodosum ganglion in the cat vagus nerve. Whereas 5% DMSO does not affect the FAXT in all axons, 10% DMSO blocks all the FAXT. The blockage is substantially, but not completely, reversed by washing the vagus for 2 h. DMSO at 2% caused no discernible change in either the FAXT or the axonal morphology, but some swelling of glial cells occurred. Ultrastructurally, 10% DMSO caused some axons to swell and others to shrink. The MT appeared normal and their total number per axon did not change. The spatial relationship of the axonal constituents is clearly altered by the DMSO and this may have contributed to the failure of the transport. It is suggested that the DMSO, through strengthening the forces involved in polymerization, renders them non-functional for FAXT.     

Role of the blood-brain barrier in the anticholinergic differential effects on LH and prolactin release in proestrous rats

The effects of homatropine and atropine on plasma LH and prolactin (PRL) levels during the afternoon of pro-oestrus were investigated. Homatropine methylbromide was unable to block the spontaneous increase of LH but prevented the prolactin surge in pro-oestrous rats at doses of 450 and 700 mg/kg s.c. Atropine sulphate blocked both LH and PRL at doses of 450 and 700 mg/kg s.c. These two anticholinergics when injected into the 3rd ventricle (250 mug/rat) blocked the pro-oestrus increase of LH and inhibited PRL. Pharmacological experiments were performed in parallel and the injection of either homatropine or atropine (450 mg/kg s.c.) resulted in the abolishment of peripheral toxic signs induced by pilocarpine (50 mg/kg s.c.) whereas its central toxic signs were prevented by atropine but not by homatropine. Our findings suggest that the difference in action of systemic injections of atropine and homatropine on LH and PRL release is explained by a relatively low permeability of homatropine to the brain. Therefore, cholinergic LH-controlling mechanisms may be situated above the median eminence and those related to PRL placed outside the blood-brain barrier.     

Maternal and sex-related influences on locomotor activity in rats following weaning

The effect of the presence of the mother beyond the normal time of weaning on the locomotor activity of litters is evaluated in the present work. Weaned rats, either females or males, showed a significantly higher activity in the open-field arena than the non-weaned ones. A sex-related difference was also detected. Weaned and nonweaned females showed higher activity than the weaned and nonweaned males, respectively. The androgen-induced lowering of female activity is affected by the presence of the mother. This is substained by the fact that weaned androgenized females exhibited higher levels of activity than nonweaned androgenized females. Our observations suggest that the presence of the mother after the normal time of weaning disturbs the emotional maturation of litters.     

Forebrain damage following prenatal exposure to low-dose X-irradiation

Exposure of fetal rats to X-irradiation on gestational day 15 resulted postnatally in dose-related effects on body weight, growth of forebrain structures, and branching of dendrites of caudate neurons. Rats were followed for 4 months postnatally after 125, 75, 50, or 25 R whole-body irradiation to the dam. Significant decreases in body weight were present at birth after the three high doses and continued as long as 4 months after 125 or 75 R. Decreased thickness of the cerebral cortex and decreased area of the caudate nucleus were also seen. Cortical thickness was reduced by 125 R to half the size of the control cortex and the caudate nucleus to two-thirds of the control. Significant decreases were present to 50 R. Dendritic branching was reduced in caudate neurons by 125 R but not in the basilar dendrites of cortical pyramidal cells. No reduction in number of cortical synapses was seen from electron micrographs of cortical layers 1 or 5. The effect on the cerebral cortex was interpreted as a loss of neurons with retention of branching and synaptogenesis of remaining neurons. In contrast, the caudate nucleus, which develops somewhat before the cerebral cortex, showed effects as a consequence either of direct damage to caudate neurons or of reduced neuropil from reduced afferent input.