The initial lesion in experimental allergic neuritis. A phase and electron microscopic study.

Experimental allergic neuritis (EAN) was produced in rats by the intradermal injection of an emulsion of peripheral nerve in Freund's adjuvant. Early lesions in perfused sciatic nerves were studied by phase, light, and electron microscopy at intervals up to 15 days following immunization. Circulating lymphocytes attached focally to the inner surface of blood vessels, primarily venules, to initiate parenchymal lesion formation. Attached cells had the hand mirror configuration typical of the motile lymphocyte. They subsequently flattened against the endothelial surface and then traversed the vascular wall by sinking into and passing through the cytoplasm of endothelial cells. The transgressor and transgressed cell membranes were intact and both cells retained their integrity. Lymphocytes began to transform and divide intravascularly; these events accelerated extravascularly. Although the migrating cells became larger and more pleomorphic in the perivascular regions, their essential character was in keeping with an origin from circulating lymphocytes. In many lesions, there was fluid with protein, possibly produced by the transformed extravascular cells. The described cellular events precede tissue damage and are likely instrumental in the myelin destruction which follows

Secretion of nerve growth factor by central nervous system glioma cells in culture.

Bacteriophage immunoassays, radioimmunoassays, and biological assays have been used to measure levels of NGF in media conditioned by rat C-6 glioma cells in culture. By all three criteria, these cells secrete a macromolecule which is indistinguishable from mouse submandibular gland NGF.

Nerve growth factor: relationship to the cyclic AMP system of sensory ganglia.

Nerve growth factor and N(6),O(2)' dibutyryl adenosine 3',5'-monophosphate both stimulate neurite elongation by explanted ganglia. However, the addition of nerve growth factor does not lead to increased amounts of adenosine 3',5'-monophosphate in intact ganglia, nor does it stimulate adenylate cyclase activity in broken ganglia cells.

Antiserum to immunoglobulin A: Inhibition of cell-mediated demyelination in tissue culture.

Lymph node cells from rats immunized with sciatic nerve in Freund's adjuvant demyelinate trigeminal ganglion cultures. Rabbit antiserum to rat immunoglobulin A blocks this cytodestructive event. The antiserum may act by combining with IgA on the lymphoid cell surface, preventing the interaction of cell-bound antibody and tissue anitigen.

Secretion of a nerve growth factor by primary chick fibroblast cultures.

Normal primary chick embryo fibroblast cultures product a nerve growth-promoting factor which cross-reacts with monospecfic antibody to pure male mouse submaxillary gland nerve growth factor (NGF). When taken together with the earlier demonstration that mouse L2 CELLS AND 3T3 cells also produce an NGF-like protein, these findings suggest that secretion of this factor may be a general property of fibroblast.

Suppressor and cytolytic cell function in multiple sclerosis. Effects of cyclosporine A and interleukin 2.

Patients with progressive multiple sclerosis (MS) demonstrated persistent reductions in levels of concanavalin A (Con A)-induced suppressor activity and heightened levels of in vitro pokeweed mitogen (PWM)-induced IgG secretion. The reduced Con A suppressor activity could not be reversed by addition of interleukin 2 (IL-2). Cyclosporine A (CsA) treatment did not alter the defect in Con A-induced suppressor activity, but did markedly inhibit T8+ cell-mediated alloantigen directed cytolytic activity; this latter defect was reversible by in vitro addition of IL-2. CsA-treated patients did not differ from placebo-treated patients with regard to levels of PWM-induced IgG secretion or proliferative responses of their mononuclear cells to Con A. The results indicate that CsA treatment of MS patients reduces cytolytic function from baseline normal values, but does not alter aberrant suppressor cell function.

Tumor growth: suppression in mice by submanidibular gland extirpation.

Transplanted A-10 breast adenocarcinomas grew more slowly in young-adult male A/HeJ mice from which the submandibular glands had been extirpated than in sham-operated or unoperated control mice of the same strain. The mitotic index was lower in tumors from experimental animals than in those from controls. Vascularization about the tumor margins was also less prominent. The C1300 neuroblastoma grew more slowly in sialoadenectomized mice than in controls. Modulation of tumor growth by factors of salivary gland origin may have been responsible for these effects.

Modulatory effect of the sympathetic nervous system on neuroblastoma tumor growth.

Growth of C-1300 neuroblastoma was markedly suppressed in mice chemically sympathectomized at birth with 6-hydroxydopamine. Growth of A-10 adenocarcinoma was also somewhat reduced. In newborn mice pretreated with nerve growth factor to induce sympathetic nervous system neuronal hypertrophy, neuronal maturation, and peripheral hyperinnervation, the growth of neuroblastoma was augmented.

Effect of 6-hydroxydopamine on tumor growth.

The growth of C-1300 neuroblastoma was markedly slowed in 6-hydroxydopamine-treated mice. The growth of the A-10 breast adenocarcinoma was also significantly retarded in 6-hydroxydopamine-treated mice but the growth of B-16 melanoma was not affected. In mice axotomized by pretreatment with 6-hydroxydopamine, the growth of C-1300 neuroblastoma was slowed but the growth of the A-10 tumor was not affected. It is suggested that an intact functional sympathetic nervous system may be a factor that determines the rate of growth of certain tumors in vivo.

Toxicity of methyldopa (Aldomet) to mouse neuroblastoma cells in vivo.

The adrenergic blocking agent methyldopa (Aldomet) is toxic to C-1300 neuroblastoma cells in vivo. Four injections of Aldomet at a dose of 7.5 mg/injection were given over a period of 24 hr to C-1300 neuroblastoma-bearing mice. This treatment killed a significant proportion of the C-1300 neuroblastoma cells. Flow cytometric data suggest that sensitivity of tumor cells to Aldomet is not related to the cell cycle.

Influence of the sympathetic nervous system on the growth of neuroblastoma in vivo and in vitro.

The sympathetic nervous system exerts a trophic-mitogenic influence on C-1300 mouse neuroblastoma. We now report that sympathetic axotomy suppresses growth of the S-20 clonal line of neuroblastoma but does not influence the growth in vivo of two other clonal lines, NIE-115 and C-46. Sympathetic ganglia-conditioned medium significantly increases proliferation of S-20 cells in vitro. Growth of NIE-115 and C-46 clonal neuroblastoma lines is not influenced by sympathetic ganglia-conditioned medium. We postulate that the sympathetic nervous system secretes a mitogenic-trophic factor that favors growth of C-1300 neuroblastoma in vivo. Sensitivity to this factor varies between neuroblastoma clonal lines.

Sympathetic nervous system trophism for neuroblastoma and its age dependence in rats.

The sympathetic nervous system modulates the growth of C-1300 mouse neuroblastoma in vivo and in vitro. We now report that a mitogenic/trophic factor that augments growth of C-1300 neuroblastoma and of the S-20 neuroblastoma clonal line is present in freshly excised sympathetic cervical ganglia from newborn rats, but is not detectable in homogenates from sympathetic ganglia obtained from adult rats.

Treatment of mouse muscular dystrophy with the protease inhibitor pepstatin.

Dystrophic mice were treated for 5 weeks beginning at 3 weeks of age with 20 ugm per day of pepstatin, a potent inhibitor of cathepsin D. Mortality was less and weight gain greater in pepstatin treated mice than in controls. Muscle bulk was greater and hind lamb contractures were reduced in treated mice. Mean muscle fiber mass was significantly increased by pepstatin treatment. Inhibition of muscle protease may be the mechanism by which pepstatin slows the tempo of progression of mouse muscular dystrophy.

Histocompatibility types and viral antibodies.

Serum neutralizing (Nt) antibodies to herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), and histocompatibility (HL-A) types, were determined in multiple sclerosis (MS) patients and in control subjects. Titers of Nt antibodies to HSV-1 and to HSV-2 were increased among subjects bearing HL-A3 or HL-A7 or both, whether they suffered from MS or not. The increases were statistically significant in the MS group. The MS and control groups did not differ significantly in levels of HSV-1 or HSV-2 Nt antibodies.

Experimental allergic encephalomyelitis. Passive transfer by the intraocular injection of sensitized cells.

Experimental allergic encephalomyelitis is a disease of cell-mediated immunity and can be transferred passively to virgin recipients by lymphoid cells from sensitized donors. The rabbit eye contains myelinated medullary rays that can be visualized ophthalmoscopically. Intraocular injection of autologous lymph node cells from myelin basic protein (BP)-immunized rabbits into the vitreous leads to readily visualized optic neuritis while injection of cells from adjuvant immunized control rabbits does not. Microscopical study confirmed the presence of myelin destruction in recipients of cells from BP-sensitized donors. This eye chamber technique provides a simple model for the study of demyelination in vivo under direct observation.

All-trans retinoic acid potentiates the ability of interferon beta-1b to augment suppressor cell function in multiple sclerosis.

OBJECTIVE: To determine the effects of combination all-trans retinoic acid (RA) and interferon beta-1b therapy on immune system functions potentially relevant to multiple sclerosis (MS). DESIGN: Interferon gamma-secreting cells, T suppressor cell function, and lymphocyte proliferative responses were assayed using peripheral blood mononuclear cells from patients with MS and control subjects under control conditions and in the presence of interferon beta-1b, RA, and the 2 combined. SETTING: A university hospital MS clinic. PARTICIPANTS: Seventeen patients with secondarily progressive MS and 25 control subjects. RESULTS: Interferon beta-1b use increased interferon gamma-secreting cell counts, augmented T suppressor cell function, and inhibited T-cell proliferation. Therapy with RA decreased interferon gamma-secreting cell counts, had a minimal positive effect on T suppressor cell function, and had no effect on T-cell proliferation. When RA and interferon beta-1b were combined, the inhibitory effect of RA on interferon gamma-secreting cells predominated, T suppressor cell function increased synergistically over the increment observed with interferon beta-1b use alone, and the inhibitory effect of interferon beta-1b alone on T-cell proliferation remained unchanged. CONCLUSIONS: Treatment with interferon beta-1b partially restores defective T suppressor cell function in patients with MS. This potentially beneficial action is synergistically potentiated by RA. Interferon beta-1b increases the number of interferon gamma-secreting cells in the circulation when treatment is initiated. A similar increment in interferon gamma-secreting cells is observed when interferon beta-1b is added to cultural peripheral blood mononuclear cells in vitro. This potentially deleterious action of interferon beta-1b is reversed by RA. Interferon beta-1b inhibits lymphocyte proliferation modestly but reproducibly. This action of interferon beta-1b is unaltered by RA. These data provide a rationale for a trial of combination treatment with interferon beta-1b and RA in patients with MS.

Histocompatibility typing in amyotrophic lateral sclerosis.

Histocompatibility (HL-A) phenotypes of 44 unrelated white patients from the greater Boston area with amyotrophic lateral sclerosis (ALS) and 200 white controls were compared. In the overall ALS group, an increased frequency of HL-A3 was noted (43% vs 25%, P less than .05). Thirty-eight patients had rapidly progressive disease; among this group the HL-A3 incidence was 50% (P less than .005). Six patients had slowly progressive disease, none had HL-A3, and five had HL-A12. The HL-A antigens may link with disease severity in ALS.

Etretinate augments interferon beta-1b effects on suppressor cells in multiple sclerosis.

BACKGROUND: Interferon beta treatment is only partially effective in multiple sclerosis (MS) suggesting a potential role for adjunctive therapies. Retinoids can augment the clinical efficacy of type 1 interferons in patients with cancer. We reasoned that the same might hold in MS. Interferon beta-1b added to peripheral blood mononuclear cells in vitro partially reverses the CD8 suppressor cell defect of patients with MS. All-trans retinoic acid added to peripheral blood mononuclear cells from untreated patients with MS or from controls potentiates this ability of interferon beta-1b to augment CD8 suppressor cell function in vitro. OBJECTIVE: To determine whether retinoid administration to patients with MS who are being treated with interferon beta-1b augments their CD8 suppressor cell function. SETTING: A university hospital MS clinic. PARTICIPANTS: Patients with MS who were being treated with interferon beta-1b, 14 patients with secondary progressive MS and 3 patients with relapsing remitting MS. RESULTS: Seventeen patients with MS received etretinate treatment for up to 6 months. Planned dosing was 10 mg 3 times daily for the first month, 25 mg twice daily for the second and third months, and 10 mg twice daily thereafter. The 25-mg twice daily dose was not well tolerated and of the 14 patients who remained in the phase 1 clinical trial through month 3 dose reduction to 10 mg thrice daily was required in 1 patient and to 10 mg twice daily in 4 patients. Eleven patients completed the trial. Etretinate treatment significantly augmented suppressor function over baseline values at 1, 3, and 6 months. No meaningful change was noted in disability or quality of life over the course of the phase 1 clinical trial. Neuropsychological testing of completers suggested improvement on selected aspects of verbal memory at 6 months compared with baseline values. CONCLUSIONS: Etretinate treatment at a dose of 10 mg twice or three times daily augments suppressor cell function in patients with MS receiving interferon beta-1b. Higher dose etretinate treatment (25 mg twice daily) is poorly tolerated by patients with MS. Even at 10 mg twice daily adverse experiences involving the mucous membranes and the skin become troublesome for some, but not all, patients. Whether pulse therapy or administration of retinoid restricted to the day of interferon beta dosing will also augment suppressor function, while being better tolerated, remains to be determined.

Mechanisms responsible for reduced in vitro immunoglobulin secretion in aged humans.

Age-related changes in the processes involved in T cell dependent polyclonal B cell activation in man were studied by comparing immunoglobulin (Ig) produced in autologous T:B (E+:E-) cell cultures of young and old donor pairs with Ig produced in crossover cultures. Each young and old donor was classified as a responder or a non-responder based on Ig levels in autologous pokeweed mitogen-activated T:B cultures. The data indicate that: (1) T suppressor influences are a major determinant of non-response in the young; (2) T cells of nonresponder old donors can support high levels of Ig secretion by young donors' B cells; (3) low response to pokeweed mitogen stimulation in the elderly may reflect either direct refractoriness of B cells to T cell dependent stimulation, heightened B cell sensitivity to suppressor signals, or a combination of the two.

Trigeminal neuralgia in multiple sclerosis relieved by a prostaglandin E analogue.

Trigeminal neuralgia is an uncommon but troublesome symptom of multiple sclerosis that can be refractory to conventional treatments. Misoprostol, a long-acting prostaglandin E1 analogue, relieved pain in six of seven patients who had failed to respond to conventional pharmacologic therapy.