Responses of spruce seedlings (Picea abies) to exhaust gas under laboratory conditions--I. Plant-insect interactions.

The effects of motor vehicle exhaust gas on Norway spruce seedlings (Picea abies (L.) Karst) and plant-insect interaction of spruce shoot aphid (Cinara pilicornis Hartig) was studied. The exhaust gas concentrations in the fumigation chambers were monitored and controlled by measuring the concentration of nitrogen oxides (NO(x)) with a computer aided feedback system.

Norway spruce and spruce shoot aphid as indicators of traffic pollution.

Two-year-old Norway spruce (Picea abies (L.) Karst) seedlings were exposed to traffic emissions along roadsides with three different traffic densities and speed limits; highway, street and a quiet local road. The responses of the exposed seedlings as a host plant and those of spruce shoot aphid (Cinara pilicornis Hartig) were studied.

Significance of wood terpenoids in the resistance of Scots pine provenances against the old house borer, Hylotrupes bajulus, and brown-rot fungus, Coniophora puteana.

We tested how terpenoid (i.e., monoterpenes and resin acids) composition and concentration in wood affects resistance against wood-borers and decaying fungi.

Keratocyte activation and inflammation in diffuse lamellar keratitis after formation of an epithelial defect.

Purpose: To examine the inflammatory reaction in acute or late-onset post-laser in situ keratomileusis (LASIK) diffuse lamellar keratitis (DLK) associated with an epithelial defect.

Setting: Department of Ophthalmology, Helsinki University Central Hospital, Helsinki, Finland.

Methods: Six consecutive LASIK patients presented with stage 2 to 3 unilateral DLK 1 to 4 days after formation of an epithelial detachment (intraoperatively or up to 19 months postoperatively).

Evidence for the lack of a specific interaction between cholesterol and sphingomyelin.

The putative specific interaction and complex formation by sphingomyelin and cholesterol was investigated. Accordingly, low contents (1 mol % each) of fluorescently labeled derivatives of these lipids, namely 1-palmitoyl-2[10-(pyren-1-yl)]decanoyl-sn-glycero-3-phosphocholine (PyrPC), n-[10-(1-pyrenyl)decanoyl]sphingomyelin (PyrSM), and increasing concentrations of cholesterol (up to 5 mol %), were included in large unilamellar vesicles composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) or 1,2-dinervonoyl-sn-glycero-3-phosphocholine (DNPC), and the excimer/monomer fluorescence emission ratio (I(e)/I(m)) was measured. In DNPC below the main phase transition, the addition of up to 5 mol % cholesterol reduced I(e)/I(m) significantly.

Group IIA phospholipase A(2) content in tears of patients having photorefractive keratectomy.

Purpose: To study the effect of photorefractive keratectomy (PRK) on the concentration of group IIA phospholipase A(2) (GIIAPLA(2)) in tears.

Setting: Departments of Ophthalmology and Pathology, University of Turku, Turku, and Helsinki University Eye Hospital, Helsinki, Finland.

Methods: Tear samples were collected from 25 eyes of 23 patients (mean age 32.

Reducing the physical work load and strain of personal helpers through clothing redesign.

This study assessed the effects of redesigning clients' clothing on the physical work load and strain of personal helpers. Five women, aged 18-54 years, who helped persons with physical disabilities were measured at their worksites before and after development of the clothes worn by clients. The physical work load and strain of the helpers' dressing/undressing of clients were determined from their hand and back movements, work time, muscular activity, heart rate (HR), percentage of heart rate range (%HRR), and rating of perceived exertion (RPE).

Activation of matrix metalloproteinase-8 by membrane type 1-MMP and their expression in human tears after photorefractive keratectomy.

Purpose: Matrix metalloproteinases (MMPs) play a central role in the wound-healing process. The objective of this study was to identify and characterize the levels and molecular forms of human tear fluid collagenase-2 (MMP-8) and membrane type 1-MMP (MT1-MMP or MMP-14) in patients who had undergone excimer laser photorefractive keratectomy (PRK) and in healthy subjects. Whether MT1-MMP activates pro-MMP-8 was also determined.

Toxic carriers in pepper sprays may cause corneal erosion.

We describe four patients who developed corneal erosion after an exposure to a pepper spray containing toxic carriers. Two of these patients were exposed to a pepper gas containing 5% oleoresin capsicum (OC) as an irritant and 92% trichlorethylene or unknown amount of dichloromethane as a carrier. One patient was exposed to a mock (containing 92% trichlorethylene as a carrier) training pepper gas without OC.

In vivo confocal microscopy of Fleck dystrophy and pre-Descemet's membrane corneal dystrophy.

Purpose: To assess the value of in vivo confocal microscopy (CM) in the diagnosis of Fleck dystrophy and pre-Descemet's membrane corneal dystrophy.

Methods: Case report of two patients. Standard slit-lamp and ophthalmic examination and in vivo CM were performed on both patients.

Contrasting effects of elevated carbon dioxide concentration and temperature on Rubisco activity, chlorophyll fluorescence, needle ultrastructure and secondary metabolites in conifer seedlings.

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.

Surface charge density determines the efficiency of cationic gemini surfactant based lipofection.

The efficiencies of the binary liposomes composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine and cationic gemini surfactant, (2S,3R)-2,3-dimethoxy-1,4-bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide as transfection vectors, were measured using the enhanced green fluorescent protein coding plasmid and COS-1 cells. Strong correlation between the transfection efficiency and lipid stoichiometry was observed. Accordingly, liposomes with X(SR-1) > or = 0.

Observation of topical catalysis by sphingomyelinase coupled to microspheres.

Sphingomyelinase, SMase (EC 3.1.4.

Secondary metabolite concentrations and terpene emissions of Scots pine xylem after long-term forest fertilization.

Secondary compounds are known to be associated with the resistance of conifer xylem against insects and fungi. The effects of long-term forest fertilization with nitrogen (N) or with N, calcium (Ca), and phosphorus (P) on secondary compounds in the xylem of 50-yr-old Scots pine (Pinus sylvestris L.) trees were examined.

Macroscopic consequences of the action of phospholipase C on giant unilamellar liposomes.

Macroscopic consequences of the formation of diacylglycerol by phospholipase C (PC-PLC) in giant 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) unilamellar vesicles (GUVs, diameter 10-100 microm) were studied by phase contrast and fluorescence microscopy. PC-PLC caused a series of fast stepwise shrinkages of fluid SOPC GUVs, continuing until the vesicle disappeared beyond the optical resolution of the microscope. The presence of N-palmitoyl-sphingomyelin (mole fraction X = 0.

Olfactory responses of Plutella xylostella natural enemies to host pheromone, larval frass, and green leaf cabbage volatiles.

The parasitoids Trichogramma chilonis (Hymenoptera: Trichogrammatidae) and Cotesia plutellae (Hymenoptera: Braconidae), and the predator Chrysoperla carnea (Neuroptera: Chrysopidae), are potential biological control agents for the diamondback moth, Plutella xylostella (Lepidoptera: Yponomeutidae). We present studies on the interactions between these bioagents and various host-associated volatiles using a Y olfactometer. T chilonis was attracted to a synthetic pheromone blend (Z11-16:Ald, Z11-16:Ac, and Z11-16:OH in a 1:1:0.

Sphingomyelinase activity of LDL: a link between atherosclerosis, ceramide, and apoptosis?

Atherosclerosis is characterized by the accumulation in the arterial intima of mainly low-density lipoprotein (LDL)-derived lipids, together with apolipoprotein B-100 (apoB-100), the protein moiety of LDL. Recent studies indicate aggregation of LDL within the arterial wall to represent a critical step in the initiation of this disease. Aggregation of LDL has been further proposed to involve ceramide, the levels of which are elevated in atherosclerotic plaques as well as in LDL isolated from these lesions.

Elevated lysosomal pH in neuronal ceroid lipofuscinoses (NCLs).

We report here the intracellular (pHi) and lysosomal pH in fibroblasts of six forms of neuronal ceroid lipofuscinoses (NCLs). Acid extrusion rate and pH(i) values were measured by the membrane-permeant acetoxymethyl ester of the indicator dye, 2',7'-bis(carboxyethyl)-5-(and-6)-carboxy-fluorescein (BCECF) and lysosomal pH by a spectrofluorometric assay utilizing a novel acidotropic probe, Lysosensor yellow/blue. Intracellular pH was normal in all NCLs.

Comparison of the membrane association of two antimicrobial peptides, magainin 2 and indolicidin.

Interactions of two antimicrobial peptides, magainin 2 and indolicidin, with three different model biomembranes, namely, monolayers, large unilamellar vesicles (LUVs), and giant liposomes, were studied. Insertion of both peptides into lipid monolayers was progressively enhanced when the content of an acidic phospholipid, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) in a film of 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) was increased. Indolicidin and magainin 2 penetrated also into lipid monolayers containing cholesterol (mole fraction, X = 0.

Characterization of mixed monolayers of phosphatidylcholine and a dicationic gemini surfactant SS-1 with a langmuir balance: effects of DNA.

Monolayers of a cationic gemini surfactant, 2,3-dimethoxy-1,4-bis(N-hexadecyl-N;N-dimethyl-ammonium)butane dibromide (abbreviated as SS-1) and its mixtures with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were studied using a Langmuir balance. More specifically, we measured the force-area (pi-A) curves and determined the elastic area compressibility modulus (C) as a function of lateral packing pressure and the mole fraction of the cationic lipid (X(SS-1)), with and without DNA in the subphase. Both SS-1 and POPC exhibited smooth compression isotherms, indicating their monolayers to be in the liquid expanded state.

Mechanisms of initiation of membrane fusion: role of lipids.

Main emphasis in studies on the mechanisms of fusion of cellular membranes has been in the roles of various proteins, with far less interest in the properties of lipids. Yet, on a molecular level fusion involves the merging of lipid bilayers. Studies so far have revealed lipids forming inverted non-lamellar phases to be important in controlling membrane fusion.

Study on liposomes by capillary electrophoresis.

Liposomes made of mixtures of zwitterionic and anionic lipids were investigated by means of capillary electrophoresis and dynamic light scattering. The influence of the molar lipid ratio and of the buffers, used in the running electrolyte solution, on the physical characteristics of the liposomes were investigated. Data on effective electrophoretic mobilities, total charges as well as sizes of the liposomes are given.

Interfacial interactions of ceramide with dimyristoylphosphatidylcholine: impact of the N-acyl chain.

The mixing behavior of dimyristoylphosphatidylcholine (DMPC) with either N-palmitoyl-sphingosine (C16:0-ceramide) or N-nervonoyl-sphingosine (C24:1-ceramide) was examined using monomolecular films. While DMPC forms highly elastic liquid-expanded monolayers, both neat C16:0-ceramide and C24:1-ceramide yield stable solid condensed monomolecular films with small areas and low interfacial elasticity. Compression isotherms of mixed C16:0-ceramide/DMPC films exhibit an apparent condensation upon increasing X(cer16:0) at all surface pressures.

The assembly factor P17 from bacteriophage PRD1 interacts with positively charged lipid membranes.

The interactions of the assembly factor P17 of bacteriophage PRD1 with liposomes were investigated by static light scattering, fluorescence spectroscopy, and differential scanning calorimetry. Our data show that P17 binds to positively charged large unilamellar vesicles composed of the zwitterionic 1-palmitoyl-2-oleoyl-phosphatidylcholine and sphingosine, whereas only a weak interaction is evident for 1-palmitoyl-2-oleoyl-phosphatidylcholine vesicles. P17 does not bind to negatively charged membranes composed of 1-palmitoyl-2-oleoyl-phosphatidylglycerol and 1-palmitoyl-2-oleoyl-phosphatidylcholine.