Helene C. Rauch

Prenatal cocaine exposure in the laboratory mouse: Effects on maternal water consumption and offspring outcome

Pregnant mice were given 50 mg/kg cocaine HCl (1% solution, sc) once daily from gestation days 7 through 18 (sperm positive = day 0; term = day 19). Pair-fed and untreated control groups were also used. The pregnant cocaine-treated females showed normal weight gain and food consumption but had significantly increased water consumption. The cocaine-treated group had a significant increase in embryonic resorptions but no significant effects on stillbirths or postnatal mortality. The offspring of cocaine-treated females had significantly reduced birth weights and postnatal weight gains up to the age of 28 days. There was also a delay in their ear opening but not in other maturational milestones. Increased water consumption following cocaine treatment has been reported by other studies. We speculate that cocaine has a diuretic effect. We discuss the implications of this effect during pregnancy.

Chronic Theiler's virus infection in mice: appearance of myelin basic protein in the cerebrospinal fluid and serum antibody directed against MBP

Abstract Myelin basic protein (MBP) appears frequently in the cerebrospinal fluid (CSF) of mice with chronic demyelination following intracerebral infection with Theilers murine encephalomyelitis virus (TMEV); antibody to MBP can frequently be found in the sera. The peaks of the immune responses to both MBP and TMEV coincide with the time course of the clinical signs of disease. Adsorption of mouse sera with TMEV or MBP indicate the non-identity of the antigens and the specificity of the antisera as measured by ELISA. Immunoblot analysis of sera confirmed the ELISA findings. The mechanism of induction of antibody directed against MBP and its role in TMEV-associated demyelination remain to be determined.

An enzyme-linked immunosorbent assay for antibody against acetylcholine receptor.

An enzyme-linked immunosorbent assay is described for measurement of antibody against Torpedo acetylcholine receptor. As here developed, the assay is highly sensitive, reproducible, and requires small quantities of immunological reagents. Relative measurements of antibody concentration by this method are proportional to those determined by radioimmunoassay.

Natural Killer Cell Activity in Multiple Sclerosis and Myasthenia Gravis

Because of the potential role of Natural Killer (NK) cells in viral immunity and immunoregulation, we have undertaken a study of NK activity of peripheral blood lymphocytes from both Multiple Sclerosis (MS) and Myasthenia Gravis (MG) patients, two chronic diseases in which a viral etiology and an induced autoregulatory abnormality are strongly implicated. No significant difference between the mean NK activity in MS patients and controls was observed. A difference was observed between the NK activity of female MG patients and female controls, but no difference was seen between male MG patients and controls.

Effects of cardiotoxin d from naja naja siamensis snake venom upon murine splenic lymphocytes

Cardiotoxin D from Naja naja siamensis is cytotoxic to T-lymphocytes above 150 femtomoles/10(6) cells. Equivalent lysis of macrophages or B-lymphocytes requires at least 1000 times more toxin. Reduction and carboxamidomethylation of cardiotoxin D does not effect T cell lysis. At higher toxin concentrations, 50% T-cell lysis occurs within 10 min. Splenocytes cultured with mitogens are up to five times more susceptible to toxin than unstimulated cells. Cardiotoxin D may directly disrupt the plasma membrane, since lysis is unaltered at 4 degrees C.

Experimental allergic encephalomyelitis: Prevention with a nontoxic derivative of a cobra neurotoxin

Abstract Treatment with a cobra neurotoxin derivative protects guinea pigs from experimental allergic encephalomyelitis induced by myelin basic protein. The neurotoxin derivative and myelin basic protein cross react immunologically at both the cellular and humoral levels. We propose that the molecular basis for the immunologie relationship between these proteins is centered in their respective tryptophan-containing regions.

II. Application of high performance liquid chromatography to the preparation of encephalitogenic myelin basic protein

Abstract Two preparations of myelin basic protein (MBP) were derived from an acid extraction of chloroform-methanol defatted bovine spinal cord. The first was purified by ion-exchange chromatography using guanidine-HCl; the second, by high performance liquid chromatography (HPLC) using a triethylamine eluant. Both methods of preparation yield MBP which is identical on acid-urea polyacrylamide gel electrophoresis and which has identical encephalitogenic potency. Because of the greater time-efficiency of the HPLC system with no deleterious side effects due to buffer contamination, this latter method can be recommended for MBP purification.

Experimental allergic encephalomyelitis in mice: presence of myelin basic protein in cerebrospinal fluid

The concentration of myelin basic protein (MBP) in cerebrospinal fluid (CSF) correlates with the development of experimental allergic encephalomyelitis following intradermal injection with encephalitogen in adjuvant; MBP is absent in controls inoculated with adjuvants only. The presence of MBP is a sensitive indicator of disease inasmuch as CNS-inoculated mice with neurologic signs had an average of 0.29 ng/microliter of MBP in their CSF and controls, including normal or adjuvants only, had an average of 0.03 ng/microliter. The amount present per microliter of CSF, as well as the absolute amount, obtained from an individual mouse do not always reflect the severity of disease as indicated by clinical signs and the pathology observed in a sampling of the neuraxis. The presence of MBP does correlate with demyelination, although the extent of pathology observed by light microscopy in the mouse model is minimal, associated only with the inflammatory response, and does not extend beyond the zone of the perivascular cuff.

Clinical correlates of enzyme-immunoassay versus radioimmunoassay measurements of antibody against acetylcholine receptor in patients with myasthenia gravis

Antibody against human nicotinic acetylcholine receptor [Ab(AcChR)] was measured in the sera obtained from 55 patients with myasthenia gravis (MG) using both radioimmunoassay (RIA) and enzyme-linked immunosorbent assay (ELISA). By at least one assay, 91% of the patients had elevated Ab(AcChR). We found no correlation between the amount of Ab(AcChR) measured by RIA and that measured by ELISA. Patient subpopulations defined by ELISA- or RIA-measured Ab(AcChR) were associated with different disease durations. All of those who had high Ab(AcChR) levels by both assays had experienced symptoms for less than 2 years. 87% of those with high Ab(AcChR) levels by ELISA had had MG for less than 4 years. Those patients with high Ab(AcChR) only by RIA had a mean disease duration of over 8 years. With regard to correlations of Ab(AcChR) with patient age and sex, females under 50 years of age had high levels of Ab(AcChR) by RIA, but had lower levels by ELISA, whereas men over 50 had high Ab(AcChR) levels by ELISA. Using either assay, no relationship was established between concentrations of Ab(AcChR) and the patients functional status, previous thymectomy, or current therapy. In this study, 16% of the MG patients with elevated Ab(AcChR) would have been considered within the non-disease range of Ab(AcChR) had only the RIA been performed, thus recommending the routine use of both assays for diagnostic purposes.

Antibody response to synthetic encephalitogenic peptide

Abstract Tryptophan-peptide (Trp-peptide) which represents amino acids Phe-Ser-Trp-Gly-Ala-Glu-Gly-Gln-Lys of bovine central myelin basic protein (MBP) was chemically synthesized according to Merrifields procedure. This synthetic nonapeptide induces experimental allergic encephalomyelitis in guinea pigs and rabbits. Antisera to Trp-peptide were raised in chickens and rabbits using Trp-peptide conjugated to bovine serum albumin or polymerized alanine-lysine with water soluble 1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride. Antibody activity was assayed by agarose gel double diffusion. The antisera react with both conjugates and partially cross-react with the respective carriers. The Trp-peptide-specific antibody precipitin line can be inhibited by incubation with excess free Trp-peptide. These antisera do not react with histone, which precludes nonspecific precipitation due to interaction between highly charged proteins. However, these antisera do react with 2-hydroxy-5-nitrobenzyl bromide-treated MBP. Inasmuch as this chemical reaction modifies tryptophan, it seems unlikely that tryptophan is involved in the antigenic determinant. Fractionation of chicken antisera by gel filtration through a Sephadex G-200 column suggests that the antibody activity is associated with the first, IgM-like fraction, but not with the second fraction composed of lower molecular weight immunoglobulin.