Syncoilin isoform organization and differential expression in murine striated muscle

Syncoilin is a 64 kDa intermediate filament (IF) protein expressed in myocytes at the sarcolemma, perinucleus, myotendenous and neuromuscular junctions. Here we present a revised domain projection and structural analysis for the original isoform (sync-1) and introduce two novel syncoilin isoforms (sync-2 and sync-3) generated by exon splicing. On the basis of consensus identity we propose that syncoilin be reclassified as a type III IF protein. All three syncoilin isoforms lack a L1 domain, a significant departure from standard IF rod domain projections that is likely to impact significantly on their biological function. Our analyses indicate that syncoilin is unlikely to form classical intermediate filament structures by itself, and that the significant difference in C-terminal structure between the three isoforms indicates that they may play divergent roles in myocytes. We show that despite lacking an apparent structural role in striated muscle, syncoilin isoforms are differentially and strongly upregulated in response to cardiotoxin induced regeneration and denervation induced atrophy in the C57BL/6 mouse, possibly suggesting an atypical role for syncoilin in muscle.     

Personal reflections on the nature of intelligence in humans and machines

Computers, the human mind, and social systems have common problems of inadequate memory and insufficient data manipulation speed. In each of these domains, information compression techniques have evolved to reduce storage and processing needs. Among the techniques for information compression, coding of information in procedures stands out as exceptionally powerful. Procedural information coding also gives rise to behavior that may be defined as intelligent. It is found in the human mind, in machines and in social systems. Its use in human thought is aided by language development which promotes regular review of abstract procedures. A practical consequence of better understanding of procedural information coding is the possibility of training people to exhibit greater mental capacity, a controversial possibility. This paper explores the impact of data processing resource limitations, data compression and procedural thinking in men and machines.     

STUDIES ON BLOOD CAPILLARIES : I. General Organization of Blood Capillaries in Muscle

The wall of the blood capillaries of skeletal muscles (diaphragm, tongue, hind legs) and myocardium of the rat, guinea pig, and hamster consists of three consecutive layers or tunics: the endothelium (inner layer), the basement membrane with its associated pericytes (middle layer), and the adventitia (outer layer). The flattened cells of the endothelium have a characteristic, large population of cytoplasmic vesicles which, within the attenuated periphery of the cells, may attain a maximum frequency of 120/µ² of cell front and occupy ~18% of the cytoplasmic volume; these values decrease as the cells thicken toward the perikaryon. The vesicles are 650–750 A in over-all diameter and are bounded by typical unit membranes. They occur as single units or are fused to form short chains of two to three vesicles. Each configuration may lie entirely within the cytoplasm or open onto the cell surface. In the latter case, the unit membrane of the vesicle is continuous, layer by layer, with the plasmalemma. Chains of vesicles opening simultaneously on both the blood and tissue fronts of the endothelial tunic have not been observed either in sections or in a tridimensional reconstruction of a sector of endothelial cell cytoplasm. Adjacent endothelial cells are closely apposed to one another and appear to be joined over a large part of their margins, possibly over their entire perimeter, by narrow belts of membrane fusion (zonulae occludentes). Except for tongue capillaries, patent intercellular gaps are rare or absent. The middle layer is formed by a continuous basement membrane (~500 A thick) and by pericytes which lie in between leaflets of this membrane. The tips of the pericyte pseudopodia penetrate through the inner leaflet of the basement membrane and join the endothelium in maculae occludentes. The adventitia is a discontinuous layer comprising cellular (macrophages, fibroblasts, mast cells) and extracellular (fibrils, amorphous matrix) elements. The same general type of construction appears to be used along the entire length of the capillary.     

Microbiological Deterioration of Frozen Parfried Potatoes upon Holding After Thawing

Frozen parfried potatoes were thawed and stored at 55, 45, and 34 F (12.8, 7.2, 1.1 C). Significant changes in flavor and texture did not occur at these temperatures until the total bacterial count exceeded 100 million per gram. These sensory changes were produced after 4, 8, and 20 days of storage at 55, 45, and 34 F, respectively. Detectable color change appeared sooner and probably was not of microbial origin. It is unlikely that any health hazard exists under the range of conditions studied. Nevertheless, it seems undesirable to market food with such a high bacterial count. At half the storage periods given above, the count did not exceed 100,000 per gram.     

Diversity of siderophore genes encoding biosynthesis of 2,3-dihydroxybenzoic acid in Aeromonas spp.

Most species of the genus Aeromonas produce the siderophore amonabactin, although two species produce enterobactin, the siderophore of many enteric bacteria. Both siderophores contain 2,3-dihydroxybenzoic acid (2,3-DHB). Siderophore genes (designated aebC, -E, -B and -A, for aeromonad enterobactin biosynthesis) that complemented mutations in the enterobactin genes of the Escherichia coli 2,3-DHB operon, entCEBA(P15), were cloned from an enterobactin-producing isolate of the Aeromonas spp. Mapping of the aeromonad genes suggested a gene order of aebCEBA, identical to that of the E. coli 2,3-DHB operon. Gene probes for the aeromonad aebCE genes and for amoA (the entC-equivalent gene previously cloned from an amonabactin-producing Aeromonas spp.) did not cross-hybridize. Gene probes for the E. coli 2,3-DHB genes entCEBA did not hybridize with Aeromonas spp. DNA. Therefore, in the genus Aeromonas, 2,3-DHB synthesis is encoded by two distinct gene groups; one (amo) is present in the amonabactin-producers, while the other (aeb) occurs in the enterobactin-producers. Each of these systems differs from (but is functionally related to) the E. coli 2,3-DHB operon. These genes may have diverged from an ancestral group of 2,3-DHB genes.     

Synthesis and growth regulator activity of fatty acyl derivatives of d-glucose and d-galactose

In an attempt to gain information about one or more components of the brassin complex, fatty acid esters of d-glucose and d-galactose were prepared and tested for growth regulator activity in a bean hypocotyl bioassay. 4-O-Acyl-d-glucoses and, perhaps, 1-O-acyl- d-galactoses had a similar qualitative activity to that of the brassin complex. 3-O-Acyl- d-galactoses inhibited elongation of bean hypocotyls and stimulated rooting. 3- And 6-O- acyl-d-glucoses both stimulated and inhibited elongation, depending on the source of fatty acids; in both cases, stimulation was observed when safflower oil was used as the source of fatty acids and inhibition was observed when peanut oil was used as the source of fatty acids. Fatty alkyl β-d-galactopyranosides were inactive.     

Potentiated lymphokine-activated killer cell activity generated by low-dose interleukin-2 and mismatched double-stranded RNA

Summary Lymphokine-activated killer (LAK) cell activity was measured in human peripheral blood mononuclear cells (PBMC) treated in vitro for 3 days with recombinant interleukin-2 (rIL-2) and mismatched double-stranded RNA (dsRNA). Lytic activity was measured utilizing K562 (NK-sensitive) and 786-0 (NK-resistant) target cells. PBMC cultured with rIL-2 (10–1000 BRMP U/ml) alone showed concentration-dependent lytic activity against the 786-0 target cells, while cells cultured in unsupplemented medium or medium supplemented with mismatched dsRNA (200 µg/ml) alone could not lyse the 786-0 targets. The combination of mismatched dsRNA with suboptimal concentrations of rIL-2 (10–30 U/ml) showed enhancement of both natural killer (NK) and LAK cell activities. The uptake of [³H]thymidine by treated effector cells was dependent on time and rIL-2 concentration and was not increased in the cells treated with low-dose rIL-2/mismatched dsRNA, compared to those treated with low-dose rIL-2 or mismatched dsRNA alone. Similarly, changes in the expression of CD3, CD4, CD8, CD57, CD16 and CD25 cell surface antigens were dependent on rIL-2 concentration and not altered by the presence of mismatched dsRNA. These results indicate that mismatched dsRNA can potentiate rIL-2-induced LAK cell activity by increasing the functional activity per cell, rather than by increasing the number of activated cells.