On parallel and antiparallel topology of a homodimeric multidrug transporter.

The recently suggested antiparallel topology of EmrE has intriguing implications for many aspects of the biology of ion-coupled transporters. However, it is at odds with biochemical data that demonstrated the same topology for all protomers in the intact cell and with extensive cross-linking studies. To examine this apparent contradiction we chemically cross-linked dimers with a rigid bifunctional maleimide using Cys replacements at positions not permissible by an antiparallel topology.

Alteration of blood-brain-CSF barrier in experimental meningeal carcinomatosis. A morphologic and adriamycin-penetration study.

An experimental model of meningeal carcinomatosis has been produced by subarachnoid inoculation of B16 melanoma cells into C57BL mice. Injection of 10(3) viable cells was sufficient to cause 100% tumor incidence and death within a median survival time of 17 days. The tumor infiltrated diffusely the meninges of the brain and spinal cord and filled the ventricular system.

Evidence that central nicotinic-acetylcholine receptors are involved in the modulation of basal and stress-induced adrenocortical responses.

We investigated the involvement of central nervous system nicotinic-acetylcholine receptors in the secretory activity of the hypothalamic-hypophyseal-adrenal axis. Antiacetylcholine receptor antibodies derived from rabbits immunized with purified Torpedo-acetylcholine receptor or from myasthenia gravis patients were injected intracerebroventricularly into adult male rats for 5 consecutive days. Treatment with both preparations caused increased basal corticosterone concentrations, inhibition of the corticosterone response to ether stress, and neurological signs and motor dysfunctions.

Experimental allergic encephalomyelitis: passive transfer of resistance during lactation.

Pregnant rats challenged with encephalitogenic antigen in complete Freund's adjuvant (CFA) during pregnancy, transferred a resistance to induction of experimental allergic encephalomyelitis (EAE) in encephalitogenic challenged offspring. The resistance to induction of EAE was transferred during the whole lactation period, until weaning, and not during pregnancy. Through the milk, anti-myelin basic protein antibodies were transferred to the newborn animals.

Selective route of doxorubicin administration improves outcome in experimental malignant epidural cord compression.

Epidural spinal cord compression was produced in adult Fischer rats by injection of 10(6) viable cells of malignant fibrous histiocytoma anterior to the T-13 vertebral body. Using a tracer dye, it was demonstrated that a portion of the inoculum was always present in the anterior epidural space at the time of inoculation. Paraplegia and incontinence occurred consistently on Days 14 to 27 (median, 23 +/- 3.

Waterborne outbreak of Campylobacter enteritis.

A report is given on an outbreak of enteritis which occurred in July 1982 in a kibbutz near Jerusalem. About 150 of the 512 inhabitants were affected. Campylobacter jejuni was isolated from ten out of 42 stool samples examined toward the end of the outbreak.

Effect of intracerebroventricular injection of nicotinic acetylcholine receptor antibodies on ACTH, corticosterone and prolactin secretion in the male rat.

The aim of the present study was to investigate the involvement of CNS nicotinic receptors for acetylcholine in the secretory activity of the hypothalamo-hypophyseal-adrenal axis and prolactin (PRL). Adult male rats received a daily intraventricular injection of partially purified nicotinic acetylcholine receptor antibodies (anti-AChR) obtained from a female patient with myasthenia gravis, for 5 consecutive days. Control animals were treated similarly with immunoglobulins obtained from a healthy woman.

Alpha-fetoprotein suppresses experimental allergic encephalomyelitis.

Experimental allergic encephalomyelitis (EAE), induced in guinea pigs by immunization with myelin basic protein (MBP) or whole CNS homogenate was successfully treated, as well as partially prevented, by daily administration of fetal alpha-fetoprotein (alpha FP). alpha FP which is produced in high quantities during pregnancy can inhibit both the cell-mediated immune response to MBP and the binding of MBP antibody to the antigen in vitro. It has a non-specific immunosuppressive effect on both the cellular and humoral responses.