OBJECTIVE: Central lines in NICUs have long dwell times. Success in reducing central line-associated bloodstream infections (CLABSIs) requires a multidisciplinary team approach to line maintenance and insertion. The Perinatal Quality Collaborative of North Carolina (PQCNC) CLABSI project supported the development of NICU teams including parents, the implementation of an action plan with unique bundle elements and a rigorous reporting schedule. The goal was to reduce CLABSI rates by 75%. METHODS:Thirteen NICUs participated in an initiative developed over 3 months and deployed over 9 months. Teams participated in monthly webinars and quarterly face-to-face learning sessions. NICUs reported on bundle compliance and National Health Surveillance Network infection rates at baseline, during the intervention, and 3 and 12 months after the intervention. Process and outcome indicators were analyzed using statistical process control methods (SPC). RESULTS:Near-daily maintenance observations were requested for all lines with a 68% response rate. SPC analysis revealed a trend to an increase in bundle compliance. We also report significant adoption of a new maintenance bundle element, central line removal when enteral feedings reached 120 ml/kg per day. The PQCNC CLABSI rate decreased 71%, from 3.94 infections per 1000 line days to 1.16 infections per 1000 line days with sustainment 1 year later (P 5 .01). CONCLUSIONS:A collaborative structure targeting team development, family partnership, unique bundle elements and strict reporting on line care produced the largest reduction in CLABSI rates for any multiinstitutional NICU collaborative.

Transverse sections of immature and mature sugarcane internodes were investigated anatomically with white and fluorescence light microscopy. The pattern of lignification and suberization was tested histo‐chemically. Lignification began in the xylem of vascular bundles and progressed through the sclerenchymatic bundle sheath into the storage parenchyma. Suberization began in parenchyma cells adjacent to vascular bundle sheaths and spread to the storage parenchyma and outer sheath cells. In mature internodes most of the storage parenchyma was lignified and suberized to a significant degree, except in portions of walls of isolated cells. The pattern of increasing lignification and suberization in maturing internodes more or less paralleled an increase of sucrose in stem tissue. In mature internodes having a high sucrose concentration, the vascular tissue was surrounded by thick‐walled, lignified and suberized sclerenchyma cells. The apoplastic tracer dyes triso‐dium 3‐hydroxy‐5,8,10‐pyrenetrisulfonate (PTS) and amido black 10 B, fed into cut ends of the stalk, wereconfined to the vascular bundles in all internodes above the one that was cut — with no dye apparently in storage parenchyma tissue. Thus both structural and experimental evidence is consistent with vascular tissue being increasingly isolated from the storage parenchyma as maturation of the tissue proceeds. We conclude that in mature internodes the pathway for sugars from the phloem to the storage parenchyma is symplastic. The data suggest that an increasingly greater role for a symplastic pathway of sugar transfer occurs as the tissue undergoes lignification/suberization.

Both the mesophyll and bundle-sheath cells associated with the minor veins in the leaf of Amaranthus retroflexus L. contain abundant tubular endoplasmic reticulum, which is continuous between the two cell types via numerous plasmodesmata in their common walls. In bundle-sheath cells, the tubular endoplasmic reticulum forms an extensive network that permeates the cytoplasm, and is closely associated, if not continuous, with the delimiting membranes of the chloroplasts, mitochondria, and microbodies. Both the number and frequency of plasmodesmata between various cell types decrease markedly from the bundle-sheath - vascular-parenchyma cell interface to the sicve-tube member - companion-cell interface. For plants taken directly from lighted growth chambers, a stronger mannitol solution (1.4 M) was required to plasmolyze the companion cells and sieve-tube members than that (0.6 M) necessary to plasmolyze the mesophyll, bundle-sheath, and vascular-parenchyma cells. Placing plants in the dark for 48 h reduced the solute concentration in all cell types. Judging from the frequency of plasmodesmata between the various cell types of the vascular bundles, and from the solute concentrations of the various cell types, it appears that assimilates are actively accumulated by the sieve-tube - companion-cell complex from the apoplast.

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Individual spongy mesophyll cells in green areas of variegated Coleus blumei leaves were injected with the symplast‐mobile dye lucifer yellow and its movement to other cell types was followed with fluorescence microscopy. In 13 trials, the dye remained in the injected cell twice, moved only to other mesophyll cells five times, and moved up to and along minor veins six times. Where extensive movement of the dye occurred, the tissue was fixed with 4% glutaraldehyde, dehydrated, embedded in plastic, sectioned at 3 μm, and examined again with fluorescence microscopy. The dye was found in abaxial bundle‐sheath cells for up to 200 μm or more distant from the site of injection near the minor vein, but no convincing evidence was found for its presence in the vascular tissue itself. It thus appears that superficial whole‐mount views of lucifer yellow movement along leaf minor veins cannot be taken as certain evidence for symplastic transport of the dye into and along the vascular tissues.

1990. Structural aspects of the leaves of seven species of Portulaca growing in Hawaii. Can. J. Bot. 68: 1803-181 1.Seven species of Portulaca growing in Hawaii can be divided into two groups based on the morphology, anatomy, and ultrastructure of their leaves. Portulaca oleracea, P. molokiniensis, P. lutea, forming group A, have spatulate to obovate leaves, paradermal minor veins, and mesophyll cells that completely encircle the minor veins. The chloroplasts in their bundle sheath cells are larger than those in the mesophyll cells and have well-developed grana and reduced peripheral reticulum. Bundle sheath mitochondria are larger and more numerous than those in the mesophyll, and chloroplasts in the mesophyll cells have well-developed grana and peripheral reticulum. Portulaca pilosa, P. villosa, P. sclerocarpa, and P. "ulupalakua," forming group B, have lanceolate to oblong-oblanceolate leaves, peripheral minor veins, and incomplete wreaths of mesophyll cells. The choroplasts in their bundle sheath cells are about the same size as those in the mesophyll and have reduced grana and well-developed peripheral reticulum. ' The bundle sheath mitochondria are about the same in size and number as those in the mesophyll, and the mesophyll chloroplasts have well-developed grana and reduced peripheral reticulum. Groups A and B may be equivalent, respectively, to types ii and i of R. C. Carolin, S. W. L. Jacobs, and M. Vesk (Aust. J. Bot. 26: 683-698, 1978) and to coronary subtypes B and A of E. V. Voznesenskaya and Y. V. Gamalei (Bot. Zh. Leningrad, 71 : 1291-1306, 1986), which constitute groupings of Portulaca species studied by those authors. KIM, I., et FISHER, D. G. 1990. Structural aspects of the leaves of seven species of Portulaca growing in Hawaii. Can. J. Bot. 68 : 1803-1811. Sept espbces de Portulaca prksentes a Hawaii peuvent Ctre rtparties en deux groupes d'aprbs la morphologie, l'anatomie et I'ultrastructure de leurs feuilles. Les Portulaca oleracea, P. molokiniensis et P. lutea, qui constituent le group A, ont des feuilles spatulks a obovCes, des nervures mineures paradermiques et des cellules de mCsophylle encerclant complbtement les nervures mineures. Les chloroplastes des cellules des gaines pCrifasciculaires sont plus gros que ceux des cellules de mCsophylle et ont des granums bien differenciks et un kticulum pCriphCrique rkduit. Les mitochondries de la gaine pCrifasciculaire sont plus grosses et plus nombreuses que celles du mtsophylle et les chloroplastes des cellules du mCsophylle ont des granums et du reticulum pCriphCrique bien diffCrenciCs. Les Portulaca pilosa, P. villosa, P. sclerocarpa et P. cculupalakua., qui constituent le groupe B, ont des feuilles IanceolCes oblongues-oblancColCes, des nervures mineures pCriphCriques et des couronnes incompletes de cellules de mesophylle. Les chloroplastes des cellules de leur gaines ptrifasciculaires sont B peu prbs de la mCme grosseur que ceux du mCsophylle et ont des granums rCduits et un rCticulum ptriphCrique bien diffCrenciC. Les mitochondries de la ga...

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Variegated leaves of Coleus blumei Benth. were exposed for 4 h to 1.85 MBq 14CO2 to study the movement of 14C assimilate from green to albino portions of the lamina. Autoradiographs showed considerable 14C activity in both veins and mesophyll of the central albino regions, whether the lamina was left intact or various parts of it were severed or removed prior to 14CO2 exposure. However, when all of the photosynthetic tissue was removed, virtually no label appeared in the albino tissue. Autoradiographs of chromatographed extracts of albino regions from intact leaves showed that sucrose was the most abundant labeled compound and that imported assimilate was unloaded and metabolized into a number of other compounds. The albino region is therefore a genuine sink. No label was imported into any part of mature leaves when lower leaves were fed 14CO2, and young developing leaves ceased to import in the tip-to-base progression typical of dicotyledonous leaves.