Natural killer activity in the peritoneal exudates of mice infected with Listeria monocytogenes: characterization of the natural killer cells by using a monoclonal rat anti-murine macrophage antibody (M1/70)

Exudates induced by i.p. injection of five listeria monocytogenes (LM) constituted a rich source of CBA/J murine natural killer (NK) cells. Maximum expression of NK activity was seen from day 2 through day 6 after initial exposure to LM. When nylon wool nonadherent peritoneal exudate cells were examined by a single-cell cytotoxicity assay, the number of cells binding to YAC-1 target cells increased after infection as did their individual lytic capacity. A monoclonal rat anti-murine macrophage antibody (M1/70), previously shown by our group to recognize human NK cells, can also be used as a marker for murine NK cells. Utilizing M1/70 and the fluorescence-activated cell sorter, selection of M1/70-labeled mononuclear cells led to the enrichment of both NK and antibody-dependent cellular cytotoxicity. These M1/70-positive cells had a distinctive morphology and contained granules on Wright-Giemsa staining. They were not phagocytic, did not contain nonspecific esterase, and lacked surface I-Ak, IgM determinants, complement receptors, and high levels of Thy 1.2.     

Neurochemical Studies of the Mesolimbic Dopaminergic Pathway: Somatodendritic Mechanisms and GABAergic Neurones in the Rat Ventral Tegmentum

Abstract: The rat ventral tegmentum (containing dendrites and somata of mesolimbic neurones) contained 1.3 μg/g of dopamine, which was reduced to 40% of the control level by reserpine. Slices of ventral tegmentum were able to accumulate and release (elevated potassium or protoveratrine A) exogenous [³H]dopamine. In parallel studies the uptake mechanism in ventral tegmentum was shown to be virtually identical to the nerve terminal uptake of [³H]dopamine by slices of nucleus accumbens. The release of [³H]dopamine was indistinguishable from that observed in substantia nigra, where there is substantial evidence for dendritic mechanisms. Basal adenylate cyclase activity was present, but dopamine-stimulated activity was not detected. A high GABA concentration (7.7 μmol/g) was present in ventral tegmentum, in conjunction with an uptake and a release mechanism for [³H]GABA. GABA and muscimol elicited a small, reproducible efflux of [³H]dopamine, but an interaction between dopamine and [³H]GABA efflux was not observed. The results are in accord with transmitter roles for dopamine and GABA in the somatoden-dritic area of mesolimbic dopaminergic neurons.     

Identification on I-Ak molecules of a functional site recognized by proliferating T-lymphocytes

The inhibitory capacity of 17 monoclonal antibodies (m.Ab.) specific for the products of the I-A ^k subregion was evaluated in proliferative responses of B10.BR T-lymphocytes to GAT, Keyhole limpet hemocyanin, and ovalbumin. Considered in isolation, each m.Ab. mediated inhibitory effects of comparable magnitude on these three different proliferative responses. On the other hand, clear differences were observed when the magnitude of the inhibitory effects was compared from one m.Ab. to another. The m.Ab. were consequently classified as strong or moderate-to-weak inhibitors of T-cell proliferative responses. Evidence was simultaneously gained indicating the following: (a) the determinants recognized by different m.Ab. were expressed on the same molecules; (b) the differences in affinity of the m.Ab. for I-A^k positive cells did not explain their differences in inhibitory capacities; (c) conversely, the inhibitory capacity of each m.Ab. followed its ability to inhibit the cell surface fixation of Ia.17-specific 10-2.16 m.Ab.; (d) the strong inhibitory capacity of some m.Ab. was not related to a special ability to modulate cell surface Ia molecules. These results suggest that antigen recognition by T lymphocytes is preferentially restricted by a functional site of the I-A^k molecules related to the Ia.17 and Ia.1 specificities.Abbreviations EDTA Ethylenediamine-tetraacetic acid disodium salt - EHAA Eagle's Hanks' amino acids medium - FCS fetal calf serum - in polypeptide G is glutamate, A, alanine, T, tyrosine - HEPES N-2-hydroxy-piperazine-N-2-ethane sulfonic acid - kd dissociation rate constant - KLH Keyhole limpet hemocyanin - LPS lipopolysaccharide - m.Ab. monoclonal antibodies - NP-40 nonidet P-40 - PBS phosphate buffered saline - PBS-BSA PBS supplemented with 1% bovine serum albumin - PBS-BSA-NP-40 PBS-BSA supplemented with 0.5% NP-40 - RT room temperature - SEM standard error of the mean - s.c. spleen cells     

Dérivés Monotritylés du D-xylose

Monotritylation of O-acetyl derivatives of D-xylopyranose and D-xylofuranose with trityl chloride in acetonitrile-pyridine gave the tri-O-acetyl derivatives of 1-,2-, 3-, and 5-O-trityl-D-xylofuranose and of 1-, 2-, 3-, and 4-O-trityl-D-xylopyranose which were required for the identification of the various monotrityl derivatives obtained in the tritylation at 50° of D-xylose with trityl chloride in pyridine or hexamethylphosphoric triamide-silver acetate.     

Mise au point d'un milieu de culture pour le dénombrement deBeauveria tenella dans les sols

Résumé Un milieu de culture permettant d'isoler et de dénombrer les colonies deBeauveria tenella parmi d'autres champignons du sol a été mis au point en vue de faciliter l'étude du comportement d'un germe entomopathogène artificiellement introduit pour lutter contre les pullulations des larves du Hanneton commun.

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Summary A culture medium composed of 8 vegetable juices, glucose, yeast extract, dried oxgall and antibiotics (actidione, streptomycine, tetracycline) allows the isolation ofBeauveria tenella blastospores or conidiospores artificialy introduced in soil when the concentration of this inoculum varies between 100 and 40,000 spores per gram.

     

Pleiotrophin Gene Therapy for Peripheral Ischemia: Evaluation of Full-Length and Truncated Gene Variants

Pleiotrophin (PTN) is a growth factor with both pro-angiogenic and limited pro-tumorigenic activity. We evaluated the potential for PTN to be used for safe angiogenic gene therapy using the full length gene and a truncated gene variant lacking the domain implicated in tumorigenesis. Mouse myoblasts were transduced to express full length or truncated PTN (PTN or T-PTN), along with a LacZ reporter gene, and injected into mouse limb muscle and myocardium. In cultured myoblasts, PTN was expressed and secreted via the Golgi apparatus, but T-PTN was not properly secreted. Nonetheless, no evidence of uncontrolled growth was observed in cells expressing either form of PTN. PTN gene delivery to myocardium, and non-ischemic skeletal muscle, did not result in a detectable change in vascularity or function. In ischemic hindlimb at 14 days post-implantation, intramuscular injection with PTN-expressing myoblasts led to a significant increase in skin perfusion and muscle arteriole density. We conclude that (1) delivery of the full length PTN gene to muscle can be accomplished without tumorigenesis, (2) the truncated PTN gene may be difficult to use in a gene therapy context due to inefficient secretion, (3) PTN gene delivery leads to functional benefit in the mouse acute ischemic hindlimb model.