Molecular and Morphological Characterization of Anncaliia azovica sp. n. (Microsporidia) Infecting Niphargogammarus intermedius (Crustacea,Amphipoda) from the Azov Sea

Five out of one hundred adults of Niphargogammarus intermedius caught at the Azov sea shore were found to be infected with microsporidia. The infection was found in the subcuticular fat body and myocytes. Parasites developed in direct contact with host cells, displayed a disporoblastic sporogony and diplokaryotic arrangement of nuclei at all stages. Spores were oval, 4.6–5.8 × 2.6–3.0 μm. Exospore appendages, vesicular–tubular secretions, and the anisofilar polar filament indicated a similarity to Anncaliia species. Sporont surfaces displayed ridges of amorphous material. Meronts and sporonts formed protoplastic extensions, similar to A. vesicularum and A. meligheti. Mature spores possessed a bipartite polaroplast. The polar tube was arranged in one row of 13–18 coils including 0–3 distal coils of lesser diameter. Partial sequencing of SSU, ITS, and LSU regions of rRNA gene (GenBank accessions: KY288064 – KY288065 ) confirmed this new species to be congeneric with A. algerae (# AF069063 ) and A. meligheti (# AY894423 ). The SSU gene of this novel microsporidium shared 99.4% sequence similarity to A. algerae and 98.9% to A. meligheti. Genes for HSP70 and RPB1 amplified with primers designed for A. algerae orthologs displayed 99.7% and 97.4% similarity, respectively, between A. algerae and the novel microsporidium. A new species, Anncaliia azovica, is described based on morphological and molecular characterization.     

Copper(II) complexes of a hydroxamic acid from maize

The thermodynamics of formation for DIMBOA-Cu(II) complexes (where DIMBOA = 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3-4H-one, a hydroxamic acid from maize) has been investigated in aqueous solutions by a potentiometric method. DIMBOA forms 1:1 and 1:2 chelates with Cu(II) at ionic strength 0.05 M (NaCl04). The stability constants measured were about 10⁵ and 10⁴ for the 1:1 and 1:2 complexes respectively, determined at 10, 20 and 30°. The contribution of ΔH and ΔS to the stability of complexes is examined and the pK values are compared with other ligands found in maize. Although DIMBOA has similar or higher constants to form copper complexes than other plant ligands, its possible role as a transport agent in maize remains to be established.     

Effects of GnRH on Neurite Outgrowth,Neurofilament and Spinophilin Proteins Expression in Cultured Spinal Cord Neurons of Rat Embryos

It has been previously described the presence of GnRH receptor in spinal cord neurons of rat embryos and adult rats. However, the functional role of these receptors has not been studied. In this work, the effect of GnRH on neurite outgrowth and cytoskeletal protein expression in cultured spinal cord neurons of rat embryos was analyzed. Specifically, neurofilaments of 68 and 200 kDa by immunoblot assays and spinophilin mRNA expression by RT-PCR. Results show that GnRH stimulates neurite outgrowth in addition to an increase in neurofilaments and spinophilin expression. These findings suggest that GnRH may play a role as neuromodulator in neuronal plasticity and that could be considered as a potential factor for neuronal regeneration in spinal cord injuries.     

Studies on the Inhibitory Action of Opiate Compounds in Isolated Bovine Adrenal Chromaffin Cells: Noninvolvement of Stereospecific Opiate Binding Sites

In isolated bovine adrenal chromaffin cells, beta-endorphin, dynorphin, and levorphanol caused a dose-dependent inhibition of catecholamine (CA) secretion elicited by acetylcholine (ACh), with an ID50 of 50, 1.3, and 4.3 microM, respectively. The inhibition by the opiate compounds was specific for the release evoked by ACh and nicotinic drugs and was noncompetitive with ACh. Stereospecific binding sites for the opiate agonist [3H]etorphine were found in homogenates of bovine adrenal medulla (KD = 0.59 nM). beta-Endorphin, dynorphin, levorphanol, and naloxone were potent inhibitors of the binding of [3H]etorphine with an ID50 of 12, 0.4, 5.2, and 6.2 nM, respectively. However, [3,5-I2Tyr1]-beta-endorphin, [3,5-I2Tyr1]-dynorphin, and dextrorphan, three opiate compounds with no or little activity in the guinea pig ileum assay, were relatively ineffective in inhibiting the binding of [3H]etorphine (ID50 700, 600, and 10,000 nM, respectively). On the other hand, these three compounds were equipotent with beta-endorphin, dynorphin, and levorphanol, respectively, in inhibiting the ACh-evoked release of CA from the adrenal chromaffin cells (ID50 of 10, 1.5, and 6 microM, respectively). Inhibition of CA release was also obtained with naloxone (ID50 = 14) microM) and naltrexone (ID50 greater than 10(-4) M), two classical antagonists of opiate receptors, and this effect was additive to that of beta-endorphin. These data indicate that the opiate modulation of CA release from adrenal chromaffin cells is not related to the stimulation of the high affinity stereospecific opiate binding sites of the adrenal medulla. The physiological function of these sites remains to be determined.     

Asbestos-elicited catecholamine secretion from isolated bovine adrenal chromaffin cells

Standard (UICC) chrysotile B asbestos fibres caused rapid (within minutes) 5-to-8-fold stimulations of catecholamine secretion from isolated bovine adrenal chromaffin cells without affecting their viability (97%). The stimulation of catecholamine secretion by asbestos was selective to chrysotile type fibres, half-maximal stimulation by standard chrysotile B, chrysotile A, crocidolite, amosite and silica fibres being observed at 7, 73, 160, 250 and ? 500 μg per ml, respectively. The secretory effect of chrysotile B was additive to that of acetylcholine and blocked by either the divalent cations, Co²⁺, Ni²⁺ and Mg²⁺ or the ion chelators, EGTA and EDTA. Conversely, neither verapamil, methoxyverapamil, or removal of extracellular calcium affected the asbestos-evoked catecholamine secretion. These data indicate that the selective stimulatory effect of chrysotile type asbestos on adrenal chromaffin cells can be mediated by membrane or intracellular calcium and raise the question of the possible involvement of catecholamines in the pathogenesis of asbestos related diseases.     

THE IMPAIRED DRIVER—A Review of the Facts

Traffic accidents have been subject to relatively little scientific study in California. A substantial barrier to adequate basic research in this field has been the assumption that more is known about the underlying causes of accidents than actually is. For example, within the medical profession, there is a tendency to assume that physical impairments of drivers are important in the causation of accidents, although little evidence has been collected to confirm or deny this assumption.Research into the underlying causes of accidents is a worthy but infinitely complex task. It must be accomplished before the driver''s contribution to accidents can be seen in proper perspective, its components identified and dealt with on a rational basis.