An in-depth look at pressure sores using monolithic silicon pressure sensors

Three-dimensional scalar pressure distributions were measured in solid tissue near bony prominences in vitro in meat and in vivo in pigs using silicon pressure sensors. Data are in accord with previous theoretical models and indicate that pressure is three to five times higher internally near a bony prominence than it is at the skin over the prominence. Pressure sores are thus thought to begin internally; by the time they are evident at the skin, the sore has worked its way completely from bone to skin. This conclusion is in accord with previous clinical data. Future measurement of local vector forces is needed to fully characterize the force distribution in vivo.     

Mercury in blood cells—Altered elemental profiles

The study was composed of 27 persons that displayed vague symptoms similar to those of the victims of Minamata and Iraq. Skew distributions of mercury were observed in individual erythrocytes and neutrophil granulocytes when measured by PIXE. Mercury could not be detected in the platelets. The erythrocytes also displayed lowered concentrations of magnesium and zinc, together with increased concentrations of calcium and strontium. The neutrophils displayed decreased concentrations of magnesium and zinc and increased concentrations of calcium, strontium, and iron. The presence of mercury and the altered elemental profiles in the erythrocytes and the neutrophil granulocytes are suggested as early signs of exposure.     

N-Deacetylation of 2-acetamido-2-deoxy-hexosecontaining oligosaccharides and polysaccharides by calcium in liquid ammonia

N-Deacetylation of 2-acetamido-2-deoxy-hexose residues is accomplished in liquid ammonia containing calcium. Oligosaccharides, lacto-N-fucopentaose II and lacto-N-difucohexaose I, containing 3,4-disubstitutedN-acetylhexosamine residues are quantitativelyN-deacetylated. When applied to polysaccharides, however, only partialN-deacetylation was achieved.Author for correspondence. AXRD     

Hedbergia, a new genus of Scrophulariaceae from Africa

Hedbergia is described as a new, monotypic genus in the Scrophulariaceae, subfamily Rhinanthoideae, tribe Rhinantheae. The species H. abyssinica is transferred from Bartsia. Hedbergia abyssinica is the most primitive taxon so far known in the subtribe Euphrasineae.     

Effect of recombinantly-derived bovine somatotropin on reproductive performance of dairy cattle

Data from 814 cows involved in five separate full lactation studies were used to assess the effect of recombinantly-derived methionyl bovine somatotropin (sometribove) on reproductive performance. Data were separated by parity (first and second or greater), route of administration (intramuscular: i.m. or subcutaneous: s.c.), length of breeding period (number of days in milk), and level of production (high vs low). Through 305 days in milk, pregnancy rates were reduced 18% in primiparous, sometribove-treated (i.m.) cows but were not significantly affected in multiparous cows. No differences were noted in either parity group when sometribove was administered subcutaneously. The level of production was more often found to be a significant factor affecting reproductive parameters than was sometribove administration. In general, length of the breeding period and level of milk production had a greater influence on reproductive performance than treatment with sometribove.     

Immunoreactivity for laminin in the developing ventral longitudinal pathway of the brain

The first long tract to form in the brain of a vertebrate embryo is the ventral longitudinal pathway. In order to investigate what chemical cues may guide nerve growth cones along this pathway, affinity-purified antibodies to laminin and collagen type IV were used to stain sections of mouse embryos from Embryonic Days 8 through 17. A monoclonal anti-neurofilament antibody was used to show the development of the ventral longitudinal pathway in relationship to immunoreactivity for laminin and collagen type IV. At Day 8 fluorescent immunoreactivity for laminin is bright in the external limiting membrane of the neural tube, but the neuroepithelium does not show bright laminin or neurofilament immunoreactivity. At E9 the ventral longitudinal pathway is forming and punctate immunoreactivity for laminin is present on the surfaces of neuroepithelial cells in the marginal zone, through which axons of the ventral pathway extend. Punctate immunofluorescence for laminin remains concentrated in the marginal zone on Days E10 through E14, but on E16 punctate immunofluorescence was much reduced, although immunoreactivity for laminin remained bright in the maturing pial and arachnoid membranes and on blood vessels in the brain. Immunoreactivity for collagen type IV was strong in the external limiting membrane and on blood vessels, but never showed concentrated punctate immunofluorescence in the marginal zone. These results indicate that laminin may be available on cell surfaces and in extracellular spaces as an adhesive ligand for growth cones during the formation of the ventral longitudinal pathway.     

Epidermal ultrastructure of Anoplodium stichopi (Plathelminthes,Dalyellioida), a flatworm endosymbiotic in Stichopus tremulus (Holothurioida)

Summary The epidermal ultrastructure of Anoplodium stichopi Bock 1925 (Platyhelminthes, Dalyellioida, Umagillidae) was studied using transmission and scanning electron microscopy. The species lives in the perivisceral coelom of the aspidochirote holothurian Stichopus tremulus Gunnerus 1767. Two types of cells were observed in the epidermis of A. stichopi: ciliated cuboidal epithelial cells and nonciliated pear-shaped cells. The surface of the ciliated epidermal cells is folded into anastomosing ridges. Numerous coated vesicles are subjacent to the surface folds and mitochondria are abundant just below them. Observations indicate that A. stichopi takes up nutrients pinocytically from the coelomic fluid of the host. The ciliation of A. stichopi is sparse.