Aminopeptidase N purified from gypsy moth brush border membrane vesicles is a specific receptor for Bacillus thuringiensis CryIAc toxin

We have evaluated the binding of Bacillus thuringiensis Cry toxins to aminopeptidase N (APN) purified from Lymantria dispar (gypsy moth) brush border membrane vesicle (BBMV). CryIAc toxin bound strongly to APN, while either the structurally related CryIAa and CryIAb toxins or CryIC, CryIIA, and CryIIIA toxins showed weak binding to APN. An in vitro competition binding study demonstrated that the binding of CryIAc to L. dispar BBMV was inhibited by APN. Inhibition of short circuit current for CryIAc, measured by voltage clamping of whole L. dispar midgut, was substantially reduced by addition of phosphatidylinositol-specific phospholipase C, which is known to release APN from the midgut membrane. In contrast, addition of phosphatidylinositol-specific phospholipase C had only a marginal effect on the inhibition of short circuit current for CryIAa. These data suggest that APN is the major functional receptor for CryIAc in L. dispar BBMV. A ligand blotting experiment demonstrated that CryIAc recognized a 120-kDa peptide (APN), while CryIAa and CryIAb recognized a 210-kDa molecule in L. dispar BBMV. In contrast, CryIAa and CryIAb bound to both the 120- and 210-kDa molecules in Manduca sexta BBMV, while CryIAc recognized only the 120-kDa peptide. The 120-kDa peptide (APN) in L. dispar BBMV reacted with soybean agglutinin, indicating that N-acetylgalactosamine is a component of this glycoprotein.     

Physiologic and hygienic characteristics of work conditions of miners in the Far North

Workers engaged into subsurface extraction of sand containing gold were proved to work in difficult conditions characterized by stable negative temperatures, high concentrations of dust, elevated levels of noise and vibration. The drill operators demonstrated extremely unfavorable changes of physiologic processes within a shift. Those changes were compromised cardiovascular regulation, early occurrence and intensive progress of fatigue. The authors provide recommendations to normalize the work conditions and to create rational scheme of work and rest for the occupations.     

Residency training in child sexual abuse evaluation

Insertin is an actin-binding protein that has been isolated from chicken gizzard smooth muscle that has been shown to be highly homologous to amino acids 962-1292 of tensin [Weigt et al., 1992]. Because of the high homology, we investigated the question whether the mRNAs of insertin and of tensin are derived from the same gene by alternative splicing, whether insertin and tensin are encoded by two different genes, or whether insertin is a proteolytic fragment of tensin. In a Northern blot analysis, mRNA from chicken gizzard was hybridized with oligonucleotides specific for tensin and for the insertin domain of tensin. The tensin-specific oligonucleotide hybridized only with the previously reported 8- and 10-kbp RNAs. However, the insertin domain-specific oligonucleotide hybridized with a 1.2 and a 1.6 kbp RNA in addition to the 8 and 10 kbp RNA. The 1.2- and 1.6-kbp RNA occurred in small amounts, as compared with the 8- and 10-kbp RNA. Southern blot analysis of DNA cleaved by the restriction endonucleases BamH1 and HindIII demonstrated that only one gene for the insertin and tensin exists. Insertin isolated from chicken gizzard smooth muscle was investigated by mass spectrometry. The N-termini of three isolated peptides were found to begin at adjacent amino acids and were likely to be formed from tensin by proteolysis. The results suggest that, for insertin, an mRNA exists that is derived from one gene common for insertin and tensin. However, the insertin-specific mRNA contributes relatively little to expression of insertin domains in cells. Insertin preparations from chicken gizzard contain mainly insertin domains formed from tensin by proteolysis.     

Overshadowing and latent inhibition counteract each other: support for the comparator hypothesis

In 4 conditioned lick suppression experiments with rats, the combined effects of latent inhibition treatment followed by overshadowing treatment were assessed as a test of the comparator hypothesis's (R.R. Miller & L.D. Matzel, 1988) explanations of overshadowing and latent inhibition. Experiments 1 and 2 confirmed the prediction of the comparator hypothesis that combined latent inhibition and overshadowing treatments attenuate the response deficit produced by either treatment alone. Furthermore, consistent with the comparator hypothesis, posttraining changes in the associative status of the putative comparator stimulus altered responding to the target conditioned stimulus (Experiment 3), and switching contexts between latent inhibition and overshadowing treatments (Experiment 4) eliminated the interaction between the latent inhibition and overshadowing treatments.