POMC gene-derived peptides activate melanocortin type 3 receptor on murine macrophages, suppress cytokine release, and inhibit neutrophil migration in acute experimental inflammation.

To investigate the relevance of adrenocorticotrophic hormone (ACTH) therapy in human gouty arthritis, we have tested the effect of several ACTH-related peptides in a murine model of experimental gout. Systemic treatment of mice with ACTH4-10 (MEHFRWG) (10-200 microgram s. c.) inhibited neutrophil accumulation without altering peripheral blood cell counts or circulating corticosterone levels. A similar effect was seen with alpha- and beta-melanocyte stimulating hormones (1-30 microgram s.c.). In vivo release of the chemokine KC-(detected in the lavage fluids before maximal influx of neutrophils) was significantly reduced (-50 to -60%) by ACTH4-10. Macrophage activation in vitro, determined as phagocytosis and KC release, was inhibited by ACTH and ACTH4-10 with approximate IC50 values of 30 nM and 100 microM, respectively. The melanocortin receptor type 3/4 antagonist SHU9119 prevented the inhibitory actions of ACTH4-10 both in vitro and in vivo. However, melanocortin type 3, but not type 4, receptor mRNA was detected in mouse peritoneal macrophages by RT-PCR. Therefore, we propose that activation of this receptor type by ACTH4-10 and related amino acid sequences attenuates KC release (and possibly production of other cytokines) from macrophages with consequent inhibition of the host inflammatory response, thus providing a notional anti-inflammatory mechanism for ACTH that is unrelated to stimulation of glucocorticoid release.     

Moth pollination of woody species in the Cerrados of Central Brazil: a case of so much owed to so few?

We present a survey of moth pollination in woody species of the Cerrado of Central Brazil. Although with the exception of Roupala montana (which has simple polysepalous flowers arranged in dense cymes) all moth pollinated species in this community have tubular flowers, or a pseudo-tube formed from a single folded petal in Qualea grandiflora, settling moth flowers (tube less than 15 mm) vs. hawkmoth flowers (tube more than 50 mm) are markedly different in size. Moths visit some 20 woody Cerrado species, but they are probably effective pollinators of only 13 species or ca.14% of the woody taxa studied, and even in these latter species they are often very sparse visitors. Nevertheless, it is notable that moths are pollinators for 21% of the 38 most commonly distributed woody Cerrado species. Moreover, the reproductive efficacy of the studied moth pollinated species was similar to that of species pollinated by other kind of vectors.     

A Molecular and Fitness Evaluation of Commercially Available versus Locally Collected Blue Lupine Lupinus perennis L. Seeds for Use in Ecosystem Restoration Efforts

Dependence on wild seed sources is often impractical for large‐scale habitat restoration programs. Reliance on commercial seed supplies of unknown provenance and fitness is thereby warranted. Little consideration has been given, however, to how the large volumes of seed required should be sourced. We evaluated commercial and locally collected seed sources for potential use in a New York State‐based, landscape‐scale program for restoring blue lupine Lupinus perennis. Through analysis of microsatellite markers we determined that “native” lupine designations by some commercial suppliers were in fact interspecific hybrids and therefore unreliable; at least two commercial sources, however, were genetically as close to native New York populations as native New York populations were to one other. Common garden experiments revealed that seed source influenced first‐year overwintering survival and subsequent height growth of surviving plants; seed sources more closely related genetically to native New York populations survived better and produced more stems per individual in the field in the area targeted for restoration. We conclude that (1) commercial suppliers often but not always offer reliably characterized seed sources of sufficient genetic similarity to native populations to warrant their use in restoration projects and (2) genetic affinity of potential seed stock to native populations is positively related to its fitness in the environment targeted for restoration.     

Kinetics of synthesis and/or conformational changes of biological macromolecules

The analogy, in both the thermodynamics and the kinetics, of reversible polymerizations on templates (in the case wherein these are catalyzed by exoenzymes) to helix–coil transitions (in the case where these proceed only from one end of each macromolecular chain) is presented. A suggestion, based on this analogy, is made concerning the possible nature of biological control of synthesis of macromolecules (enzyme induction and repression). The equations governing the kinetics of these one-dimensional cooperative processes are presented and their solutions discussed.     

Excitatory effects of cholinergic,adrenergic and glutaminergic agonists on a buccal muscle of Aplysia

The anterior extrinsic protractors in the buccal mass of Aplysia are symmetrical sheets of branching bundles of muscle fibers which form an electrical syncytium. The addition of potassium or cholinergic, adrenergic, and glutaminergic agonists to the sea water bathing medium produces contracture of the muscle. Strychnine and cholinergic or adrenergic antagonists all block contractures produced by cholinergic and adrenergic agonists but not those produced by potassium or glutamate. Iontophoretic application through microelectrodes of acetylcholine or dopamine anywhere on the muscle surface produced a graded depolarization of the membrane. By contrast, glutamate produces depolarization only at discrete membrane sites. Endogeneous contractions often appeared spontaneously or could be induced by drug exposure. ATP inhibits endogeneous contractions.     

A study of the mating system in Dolichandra cynanchoides (Bignoniaceae): an Argentinian Chaco woodlands liane with a late-acting self-incompatibility

We estimated the outcrossing rate in a population of 14 individuals of Dolichandra cynanchoides (Bignoniaceae), a species with late-acting self-incompatibility (LSI), at a site in Chaco woodland in Santa Fe province, Argentina. A subsample of five arbitrarily chosen loci from a total of 16 allozyme loci gave mating system parameters of t_m=0.881 (SD 0.039) and t_s=0.749 (SD 0.048), thus indicating that although predominantly outcrossing, D. cynanchoides has a mixed mating system. We draw attention to the fact that mixed mating in species with LSI is a very likely scenario, given that previous studies with diverse LSI taxa have shown that mixed cross-self pollen loads on the stigma, which is probably a common occurrence with natural pollinators, result in fruits with a proportion of selfed seeds.