Intravascular ultrasound assessment of culotte stent deployment for the treatment of stenoses at major coronary bifurcations

BACKGROUND: The mechanism for the disappointing late outcome following stenting of bifurcation lesions is unclear. This prospective observational study aims to evaluate culotte stent deployment and dimensions with intravascular ultrasound (IVUS). PATIENTS AND METHODS: Patients with bifurcation stenoses were treated using two stents in a culotte configuration. After optimizing the angiographic appearance of both stents, IVUS was used to evaluate both limbs of the culotte. The main outcome measures were cross-sectional area (CSA) and minimal lumen diameter (MLD) assessed by IVUS. RESULTS: Within the culotte stent, the final mean CSA in the main limb was 6.1 mm(2) (97% of reference) and in the side-limb was 5.9 mm(2) (97% of reference). However, in each case, the minimum CSA and IVUS MLD of both limbs was at the bifurcation point. For all patients, the final mean CSA at the bifurcation point of the main limb was 4.3 mm(2) (70% of main stent) and of the side-limb was 4.4 mm(2) (75% of side stent). The IVUS MLD at the bifurcation point of the main limb was 2.1 mm (78% of main stent) and of the side-limb was 2.1 mm (84% of the side stent). Importantly, this significant residual stenosis was not detectable with quantitative coronary angiography. CONCLUSIONS: IVUS evaluation of culotte stents is feasible. The minimum IVUS CSA and MLD of both limbs of the culotte stent is at the bifurcation point. Despite an optimal angiographic appearance a significant residual stenosis was noted with IVUS at each bifurcation point.     

Effects of growth temperature on transport and membrane viscosity in Streptococcus faecalis

A shift in the growth temperature of Streptococcus faecalis from 37 to 10°C resulted in an 18% increase in the proportion of unsaturated fatty acids. Electron spin resonance spectra of spin-labeled membranes and extracted phospholipids indicated viscosity changes consistent with the alterations in fatty acid composition. Growth temperature had no significant effect on the active transport of leucine and alanine; uptake rates assayed at 10 or 35°C were essentially the same in cells grown at either 10 or 37°C. The relative rapidity of amino acid transport, which presumably contributes to the ability of S. faecalis to thrive in cold environments, is evidently unrelated to adaptive changes in the viscosity of membrane lipids.Abbreviations doxyl 4-4-dimethyloxazolidine-N-oxyl - proxyl 2,2-disubstituted 5,5-dimethylpyrrolidine-N-oxyl     

Photoreaction of tyrosin-iodinated bacteriorhodopsin at low temperature

To elucidate the role of tyrosine residues in the shift of max and the light-driven proton pump of bacteriorhodopsin~ the photochemical reaction of tyrosine-iodinated bacteriorhodopsin (tyr-mod-bR) was investigated by low-temperature spectrophotometry. After 4–5 of 11 tyrosine residues of bacteriorhodopsin were iodinated, the meta-intermediate of tyr-mod-bR in 75% glycerol solution became so stable that its decay could be observed even at room temperature and i t was stable in the dark for several hours at –65°C.Four batho-intermediates were formed by irradiation with green light (500 nm) at –170°C. Like native bacteriorhodopsin, these batho-intermediates were photoreversible at –170°C. Four corresponding meta-intermediates were also formed by irradiation at –60°C. Using the difference spectra between meta-intermediates and tyr-mod-bR, the absorption spectra of four kinds of tyr-mod-bRs, batho-intermediates, and meta-intermediates were estimated. Each was at shorter wavelengths than that of its corresponding type in native bacteriorhodopsin. The results indicate that two or more tyrosine residues have some role in determining color in native bacteriorhodopsin.     

Early Stimulation of Phosphatidylcholine Biosynthesis During Wallerian Degeneration of Rat Sciatic Nerve

Phospholipid metabolism was studied in rat sciatic nerve during Wallerian degeneration induced by crush injury. Portions of crushed sciatic nerve, incubated with labeled substrates, showed significantly higher phosphatidylcholine synthesis than normal nerve, prior to any measurable alterations of phospholipid composition. Maximum synthesis occurred 3 days after crush injury, at which time the metabolism of other phospholipids was unchanged. After a rapid decrease in biosynthetic activity, a second phase of enhanced phosphatidylcholine synthesis occurred, beginning 6 days after crush injury. Increased incorporation of [33P]phosphate, [2-3H]glycerol, and [Me-14C]choline indicated stimulation of de novo synthesis of phosphatidylcholine 3 days after injury. Neither base exchange reactions nor sequential methylation of ethanolamine phospholipids contributed significantly to phosphatidylcholine synthesis. Assay of certain key enzymes under optimal conditions in subcellular fractions of sciatic nerve revealed higher activities of cholinephosphate cytidyltransferase, choline phosphotransferase, and acyl-CoA:lysophosphatidylcholine acyltransferase in injured nerve, while choline kinase activity remained unchanged. This indicates that stimulation of phosphatidylcholine synthesis occurs via the cytidine nucleotide pathway, as well as by increased acylation of lysophosphatidylcholine. Although the cause of stimulated phosphatidylcholine synthesis remains unexplained, it is possible that trace amounts of lysophospholipids or other metabolites produced by injury-enhanced phospholipase activity may be responsible.     

The interstitial cells in the renal medulla of rat,rabbit, and gerbil in different states of diuresis

Summary The inner zone of the renal medulla of rats, gerbils, and rabbits was investigated to determine whether or not there are any characteristic ultrastructural differences between the interstitial cells of these species. The effects on the interstitial cells of water deprivation and water loading were also investigated.In all three species, the Type 1 interstitial cells, the lipid containing cells, were abundant and their distribution and topographical relations as well as their general ultrastructure were similar. The previously reported significantly higher frequency in desert rats could not be confirmed. Although the lipid droplets of the interstitial cells were smaller in gerbils and rabbits when compared to rats, their fine structure was similar. Their electron dense outer zone was sometimes associated with a granular material and/or a lamellar material with a periodicity of about 40 Å resembling phospholipid myelin figures.Water-loaded rats showed a considerable increase in the number of lipid droplets when compared to dehydrated or untreated animals. In contrast, the interstitial cells of waterloaded gerbils and rabbits were depleted of lipid droplets.We are indebted to Professor A.B. Maunsbach for valuable discussions and criticism and to Mrss. Hanne Weiling and Birthe Overgaard for competent technical assistance. The gerbils used in this study were a gift from Leo AB, Helsingborg, Sweden. This study was supported by the Danish Medical Research Council (J. nos. 512-1067, 512-1545, 512-3633)     

Besondere Haarstrukturen der Soricidae (Mammalia,Insectivora) und ihre taxonomische Deutung

Zusammenfassung Die vorliegende Untersuchung befaßt sich mit besonderen Haarfeinstrukturen der Soricidae, wobei geklärt werden soll, ob dem H-förmigen Haarquerschnitt-Profil eine taxonomische Bedeutung zukommt. Wir überprüften deshalb die betreffenden Haarstrukturen mit Hilfe des REM in 8 Gattungen.Das besondere Haarprofil, das auf das Terminalsegment der Grannenhaare beschränkt ist, findet sich bei folgenden Gattungen:Sorex, Neomys, Blarina undCryptotis, alles Vertreter der Subfamilie Soricinae. Sämtliche untersuchten Vertreter der Subfamilie Crocidurinae, d.h.Crocidura, Praesorex, Suncus undSylvisorex weisen ein einfaches Haarprofil auf.Das H-Profil wird als Synapomorphie der Soricinae angesehen und charakterisiert diese als monophyletische Gruppe. Die haarmorphologischen Kriterien ergänzen somit die osteologischen Kriterien von Repenning (1967) und sprechen für die Beibehaltung der von vielen Autoren abgelehnten Subfamilien.

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Special hair structures in Soricidae (Mammalia, Insectivora) and their taxonomic interpretation

Summary The following study should clear up the structures of the H-shaped profile found in the hairs of some shrews and show if it has a taxonomic signification. Therefore we studied the concerned hair structures by scanning electron microscopy in 8 genera.The special hair-shape, which is confined to the terminal segment of guard hairs, is found in the species of the following genera:Sorex, Neomys, Blarina andCryptotis, all members of the subfamily Soricinae. All the examined members of the subfamily Crocidurinae, i.e.Crocidura, Praesorex, Suncus andSylvisorex show a simple hair shape.The H-shaped hair characterizes the Soricinae as a monophyletic unity. Yet, the morphological criteria of hair complete the osteological criteria of Repenning (1967) an plead for the validitiy of the often refuted subfamilies.

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Mit Unterstützung des Schweizerischen Nationalfonds zur Förderung der wissenschaftlichen Forschung (Nr. 3.515.71, 3.821.72, 3.413-0.74)

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Unser Dank gilt Herrn Prof. N. Schönenberger, Herrn Prof.R. Krstic und Frau C. Regamey, die uns bei der histologischen Präparation behilflich waren, insbesondere auch Herrn Dr. T. Jalanti, der uns in die REM-Technik einführte. Kostbares Material wurde uns von Frau A. Geraets (Bonn), Herrn Prof. U. Rahm (Basel) und Herrn Dr. V. Aellen (Genf) zur Verfügung gestellt; auch ihnen sei hierfür herzlich gedankt.     

Calf development and mother-calf spatial relationships in Southern right whales

Changes in spatial relationships between mother and calf right whales (Eubalaena australis) from birth to the separation of yearling calves from their mothers were observed. During the first few weeks of a calf's life, mother and calf were within close proximity over 90% of the time, and mothers were responsible for maintenance of contact with their infants. Later calves strayed farther and initiated many more leaves and approaches than their quiescent mothers. The mothers still maintained contact with their infants. Just before migration away from the area, pair members resumed close proximity and leaves and approaches by both diminished. Yearling calves, returning to the area with their mothers after six months, stayed close to their mothers and few leaves and approaches by either pair member were recorded. The yearling calves were responsible for maintaining contact as the mothers left them more than approached them. This behaviour on the part of mothers probably contributed to weaning of yearlings and separation after a few weeks in the area.