Entomopathogenic fungal infection (Deuteromycotina: Hyphomycetes) affects water relations of the german cockroach,Blattella germanica (L.) (Dictyoptera: Blattellidae)

• 1.1. The total body water, lipid content, and cuticular permeability of fungus infected and uninfected German cockroaches, Blattella germanica, were examined.
• 2.2. Infected adult cockroaches weighed less and had significantly more body water than did uninfected specimens of the same size.
• 3.3. Uninfected medium-size nymphs weighed significantly more than infected nymphs, but there was no difference in body size between infected and uninfected small nymphs.
• 4.4. Cuticular permeability and lipid content of infected and uninfected cockroaches was not significantly different.
• 5.5. Sequestering of water by the fungal cells is discussed as a possible factor in the pathology of this fungal parasite.

     

The composition of the skin surface lipids of European cattle and buffalo steers

• 1.1. This study compared the composition of the skin surface lipids (SSL) of cattle (Bos taurus) and of buffalo (Bubalis bubalis) steers at the same level of feed intake in a thermoneutral environment.
• 2.2. There was about eight times less lipid per unit area of skin surface on the buffalo than on cattle.
• 3.3. The distribution of the different lipid classes in the SSL of the two breeds was different. Compared to cattle, the buffalo SSL was characterized by smaller proportions of wax ester bands 2 and 3 and triglycerides.
• 4.4. There were significant species differences in the fatty acid patterns of the individual lipid classes.
• 5.5. The results are discussed in relation to the functional attributes of sebum.

     

Disruption of endothelial barrier function: relationship to fluidity of membrane extracellular lamella

• 1.1. Endothelial cells were cultured in tissue culture flasks or on microcarrier beads and labeled with a lipid specific spin-label.
• 2.2. Exposure of endothelial cells to benzyl alcohol caused a dose- and time-dependent increase in membrane fluidity using electron spin resonance (ESR). Maximum fluidity was reached after a 5-min exposure to 100 mM benzyl alcohol.
• 3.3. Albumin permeability across endothelial cells cultured on micropore filters was used as an indication of endothelial monolayer integrity.
• 4.4. A significant increase in permeability occurred with 50 mM benzyl alcohol. Maximal albumin permeability was reached after a 5-min exposure to 100 mM benzyl alcohol.

     

Purification and characterization of vitellogenin from the American cockroach,Periplaneta americana

• 1.1. Vitellogenin (VG) was isolated and purified from the hemolymph of female American cockroaches.
• 2.2. The purification method used in this study comprises two steps: the first step is based on the method originally developed for purifying lipophorin from hemolymph, and the second step is the separation of VG from lipophorin by a KBr density gradient ultracentrifugation.
• 3.3. The purified VG was characterized according to molecular weight, substructure, shape and size, and lipid composition.
• 4.4. The VG molecule is almost globular in shape with the diameter of about 15.5 nm and is indistinguishable from lipophorin in shape and size.
• 5.5. The native molecular weight determined by light scattering method was 560 kDa.
• 6.6. The VG consists of four subunits with molecular weights of approximately 102, 81, 49 and 40 kDa, respectively.
• 7.7. VG is a lipoprotein and comprises 92% protein and 8% lipid.
• 8.8. Major lipid components were found to be diacylglycerol (25%) and phospholipids (71%).

     

The effect of total environmental CO2 concentrations on the ion-permeability of shore crabs,Carcinus maenas (L.)

• 1.1. Salt exchange characteristics (permeability, half-time for salinity adaptation and net salt flux after a change in salinity) of adult shore crabs were studied in relation to experimentally increased external CO₂ (TCO₂ = carbon dioxide, carbonic acid, bicarbonate and carbonate) concentrations.
• 2.2. Up to about 15mM TCO₂/1, elevated external TCO₂ concentrations induce an increase in the salt permeability of shore crabs, resulting in higher passive salt fluxes across the body wall. The effect is most pronounced in larger animals (body weight > 25 g).
• 3.3. When external TCO₂ concentrations exceed internal TCO₂ concentrations, then permeability and salt exchange drop to low values, comparable to those observed in control animals. The results clarify a connection between blood gas transport and salt transport.
• 4.4. Elevated CO₂ levels are unfavourable by inhibiting the chloride/bicarbanate pump (thus disturbing the removal of metabolically produced CO₂ and the salt uptake in a hypotonic environment). High TCO₂ levels, up to about 20 mmol TCO₂/1, cause stress but Carcinus maenas can survive, at least temporarily, at the expense of metabolic energy.

     

Biochemical aspects of Balanus hameri haemolymph,together with some comparative haemolymph data for Balanus balanus and Lepas anatifera

• 1.1. The concentration of protein in the haemolymph of Balanus hameri ranged from 2.0 to 17.3 mg/ml, and the lipid from 1.4 to 7.7 mg/ml; the haemolymph protein and lipid levels increased significantly prior to cross-fertilization.
• 2.2. The protein and lipid concentrations in Balanus balanus haemolymph were 8.1 and 1.7 mg/ml respectively.
• 3.3. The lipid concentration of Lepas anatifera haemolymph was 1.2 mg/ml.
• 4.4. The neutral lipid and phospholipid components of B. hameri and L. anatifera haemolymph were the same, with the major components of the phospholipid fraction being phosphatidyl ethanolamine and phosphatidyl choline.
• 5.5. The osmolarity (970.4 mOsm), chloride ion concentration (501.3 m-eq/l) and pH (7.29) of B. hameri haemolymph were also determined.

     

Reductive Stress Selectively Disrupts Collagen Homeostasis and Modifies Growth Factor-independent Signaling Through the MAPK/Akt Pathway in Human Dermal Fibroblasts

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Highlights

• •Changes to the proteome of skin fibroblasts subjected to reductive stress have been quantitated.
• •Only a small set of proteins is selectively diminished upon exposure to reductants.
• •Collagens (COL1A2 and COL6A2) emerge as sentinels of reductive stress.
• •Reductive stress triggers receptor-independent Akt phosphorylation at Ser473.

     

Seasonal changes of total lipids in the turtle Sternotherus odoratus

• 1.1. Seasonal variation in total lipids was examined in several body components of the turtle Sternotherus odoratus.
• 2.2. Carcass fat stores in both sexes were depleted during winter. Additionally, a decline in carcass lipids was associated with increases in gonadal mass.
• 3.3. Concentrations of liver lipids were maximal during August and minimal during winter.
• 4.4. Males showed little seasonal change in plasma lipid levels, whereas females had seasonal peaks temporally associated with ovarian development and carcass fat storage.
• 5.5. Ovarian concentrations of lipids were minimal after nesting and increased during fall.
• 6.6. Results suggest that S. odoratus uses stored fats both for reproduction and maintenance during winter.

     

Biochemical and physiological aspects of anhydrobiosis

• 1.1. The biochemical and physiological mechanisms which are involved in anhydrobiotic survival have been reviewed.
• 2.2. The physical state of water within hydrated and dehydrated organisms is discussed in relation to the concepts of “free” and “bound” water and to the “vicinal water network model” of Clegg (1979) Cell Associated Water. Academic Press, New York.
• 3.3. Evidence is presented for the replacement of “bound” water by glycerol in dried embryos of Artemia salina, but the role of high glycerol content in the free-living nematode Aphelenchus avenae has yet to be evaluated.
• 4.4. The adaptive significance of trehalose is shown to lie in the fact that because it is a non-reducing sugar, it will not participate in a “browing” reaction between reduced groups of sugars and free amino groups of dry proteins. Trehalose also inhibits “browning” reactions between reducing sugars and dry proteins.
• 5.5. The effect of dehydration on membrane permeability suggests that dried organisms suffer mostly if placed directly into a revival medium due to leakage through structurally deformed membrane systems.
• 6.6. Glycerol and trehalose may interact with lipid membranes and reduce the amount of leakage.
• 7.7. Damage to membranes caused by lipid peroxidation is discussed.
• 8.8. Results suggest that the role of high lipid contents in nematode anhydrobiotes is essentially that of a food reserve, although the morphological distribution of such lipid may be important in maintaining the spatial distribution of body tissues in the absence of bulk water.

     

Electrolyte changes,cell volume regulation and hormonal influences during acclimation of rainbow trout (Salmo gairdnerii) to salt water

• 1.1. Rainbow trout were acclimated to salt water (1.5, 2.0 or 3.0%, which means 40, 60 or 85% concentrated sea-water) and the electrolyte, glucose and cortisol concentrations of the plasma as well as the extra- and intracellular muscle space, the muscle electrolyte concentrations and the ATPase activity were analysed.
• 2.2. Plasma osmolality, Na⁺, Ca²⁺ and Mg²⁺ concentrations of the plasma had a maximum at 24 hr after the start of acclimation when acclimated to 3.0% salt water. Plasma osmolality, Na⁺ and Mg²⁺ concentrations were significantly higher during the whole acclimation time when exposed to 3.0% salt water.
• 3.3. Variations and regulations of ECS and ICS were clearly demonstrated. The intracellular electrolyte concentrations were also maximal at 24 hr.
• 4.4. The plasma glucose level was just slightly elevated, but the cortisol level clearly indicated a stress response at 24 hr.
• 5.5. The activity of gill Na-K-ATPase increased during the acclimation time.
• 6.6. The regulatory processes in trout during acclimation to salt water are compared with those occurring in tilapia and carp.

     

Solubilization and characterization of functionally coupled Escherichia coli heat-stable toxin receptors and particulate guanylate cyclase associated with the cytoskeleton compartment of intestinal membranes

• 1.1. Particulate guanylate cyclase and receptors for E. coli heat-stable enterotoxin were solubilized from the rat intestinal cytoskeletal compartment using Lubrol-PX and KC1.
• 2.2. Thirty to forty percent of the ST receptor and guanylate cyclase activities were extracted from the lipid layer with Lubrol-PX alone.
• 3.2. Seventy percent of the remaining activities were solubilized from the cytoskeleton with Lubrol-PX and KCl.
• 4.3. Guanylate cyclase solubilized from either compartment exhibited similar reaction kinetics.
• 5.4. Both high- and low-affinity classes of ST receptors were solubilized from the lipid and cytoskeleton compartments.
• 6.5. In the presence of ATPγS, ST selectively activated the guanylate cyclase solubilized from the cytoskeleton compared to that solubilized from the lipid bilayer.
• 7.6. Crosslinking experiments demonstrated a preferential solubilization of the 130 kDa receptor subunit from the cytoskeleton and the 56 kDa subunit from the lipid bilayer.
• 8.7. Development of a procedure to solubilize ST receptors and guanylate cyclase from the intestinal membrane cytoskeleton will permit purification and further detailed studies of the coupling of these activities.

     

Enhanced Salt Tolerance of Rhizobia-inoculated Soybean Correlates with Decreased Phosphorylation of the Transcription Factor GmMYB183 and Altered Flavonoid Biosynthesis

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Highlights

• •Rhizobia affects flavonoid metabolism via GmMYB183 phosphorylation.
• •Flavonoids rebalance the cellular ROS under salt stress.
• •Mechanistic insights into soybean responses to salinity revealed by proteomics.

     

Lipid components and utilization in consumers of a seagrass community: An indication of carbon source

• 1.1. The lipid components of three animals, the rock crab Nectocarcinus integrifons, the rock flathead Platycephalus laevigatus and the southern garfish Hyporhamphus melanochir, feeding in the seagrass beds at Corner Inlet, Victoria, Australia have been examined in detail in order to provide further information on seagrass community structure.
• 2.2. Biological marker compounds detected within animal gut content material were used to recognize dietary sources and then utilized by community members.
• 3.3. Both H. melanochir and N. integrifons have been shown to ingest and to varying degrees incorporate seagrass lipid material, thus further confirming the importance of seagrass carbon in the Corner Inlet environment.
• 4.4. The southern sea garfish H. melanochir is observed to remove C₁₈ PUFAs (polyunsaturated fatty acids) from ingested seagrass material.
• 5.5. Seagrass sterols are altered during incorporation into the lipids of this fish.
• 6.6. Lipid-rich digestive juices play a role in the digestive processes of all three animals.
• 7.7. Components tentatively identified as (NMI) (non-methylene interrupted) fatty acids have been detected in the lipids of the garfish H. melanochir and the crab N. integrifons.
• 8.8. The fecal material of all three animals represent possible sources of these lipids (NMI acids) in Corner Inlet sediments.
• 9.9. Based on lipid compositional data, N. integrifons feeds on Posidonia australis detritus and associated epiphyte material.
• 10.10. The removal of both plant and epibiota cellular lipids along the digestive tract of the crab was observed, although structural components such as long chain mono- and α,ω-dicarboxylic acids, which have been previously recognized as seagrass marker lipids are not directly absorbed.

     

Biphasic action of growth hormone on intestinal amino acid absorption in striped bass hybrids

• 1.1. Weekly injections of bovine growth hormone (bGH) increased the maximal transport rate of both Na⁺-dependent and Na⁺ -independent l-leucine transport with little effect on the affinity constants in the intestine of striped bass hybrids.
• 2.2. The Na⁺-dependent and the Na⁺-independent transport of the non-metabolizable analog cycloleucine was also stimulated by bGH.
• 3.3. The Na⁺ -dependent active transport was stimulated 2 days after the hormone treatment, while the stimulation of the Na⁺-independent diffusional transport was not observed until after 2 weeks of treatment.
• 4.4. Studies of intestinal morphometry and l-leucine transport using brush border membrane vesicles suggested that bGH affects intestinal amino acid absorption initially by increasing the number of transporters per cell.
• 5.5. This phase is followed by a general increase of the intestinal mass after long-term treatment with the hormone.

     

The glycogen content in stressed marine bivalves: The initial absence of a decrease

• 1.1. Changes in the glycogen content, condition, stomach content and acetic acid concentration of mussels Mytilus edulis and cockles Cerastoderma edule were followed during periods of up to 14 days of exposure (to air) at temperatures of 5 and 20°C.
• 2.2. In animals with a high glycogen content the glycogen is not used during the first 3 to 7 days, at high and low temperature respectively.
• 3.3. After this latent period the glycogen concentration often decreased, coinciding with a high mortality and an increase of the concentration of acetic acid.
• 4.4. In cockles with a low glycogen content, and kept at a high temperature, glycogen can be used from the beginning of the stress period.
• 5.5. Between species no clear differences were found.
• 6.6. The stomach content decreased during exposure; however, the stomach content amounted to only 0.5 to 0.7% of the body weight, and is thought to be of minor importance as an energy source during the stress period.
• 7.7. Especially at the higher temperatures glycogen finally is transformed into acetic acid.
• 8.8. It is concluded that during exposure, the animals do not die because of a lack of energy reserves, but because of a high accumulation of acids.

     

Utilization of body stores in embryonated ova and larvae of two coregonid species (Coregonus lavaretus L. and C. albula L.)

• 1.1. Developing eggs of whitefish (Coregonus lavaretus L.) and vendace (Coregonus albula L.) were kept at 1–2°C and some eggs taken gradually up to 8°C to provoke mass hatching of embryos.
• 2.2. Wet weight, dry matter and the contents of lipid, protein and ash were measured in fish during the course of experiment.
• 3.3. Dry matter content decreased gradually in whitefish eggs from 15.64 to 11.95% during 1 month at 1–2°C, whereas vendace eggs showed only a slight decrease from 16.27 to 15.53%.
• 4.4. In both species protein content decreased but lipid increased when approaching the natural time of hatching.
• 5.5. During delayed hatching at low water temperatures protein contributes to catabolism, whereas lipid content decreased only in the later phase of the experiment.
• 6.6. Larvae starved for 10 days after hatching lost increasing amounts of dry matter (from 26.1 to 50.3% of body weight) and protein (from 18.7 to 45.9% of body weight) as they remained longer in cold water as embryos.
• 7.7. A correspondence was found between assessment of metabolic utilization of body stores based on chemical analysis of fish body and previous work on oxygen consumption and nitrogen excretion.

     

Changes in the phospholipid composition and in fatty acids of phosphatidylcholine and phosphatidylethanolamine of various tissues of the developing tadpole of Agalychnis dacnicolor

• 1.1. Lipid changes occur in the developing tadpole of A. dacnicolor. The phosphatidylcholine content of liver and tail decrease during metamorphosis.
• 2.2. In liver, the fatty acids of phosphatidylcholine and phosphatidylethanolamine become more unsaturated.
• 3.3. In skin, phosphatidylcholine becomes more unsaturated and phosphatidylethanolamine becomes more saturated.
• 4.4. In tail, phosphatidylcholine becomes more saturated and phosphatidylethanolamine shows no change.
• 5.5. Triglycerides become more unsaturated in skin but become more saturated in tail.

     

Cloning and characterization of rabbit pancreatic colipase

• 1.1. Among the digestive enzymes synthesized by pancreas, lipase is the principle lipolytic enzyme which hydrolyses dietary glycerides.
• 2.2. For its action it requires a coenzyme, colipase.
• 3.3. The molecular mechanisms of the interaction of these two are not fully understood.
• 4.4. Further, molecular events that regulate and influence lipid absorption are ill denned.
• 5.5. The rabbit is the conventional animal model for the study of lipid absorption. We have undertaken the molecular cloning, and characterization of rabbit pancreatic colipase, the coenzyme for pancreatic lipase.
• 6.6. Colipase has been cloned from a gt 11 library of an adult rabbit pancreatic cDNA by probing with an oligonucleotide derived from human colipase sequence.
• 7.7. The total reading frame consists of 321 nucleotides coding for 90 amino acids of the functional protein and 17 nucleotides of the leader peptide.
• 8.8. Northern blot analysis revealed a distinct band around 0.5kb. Comparison with other species revealed an over all homology of 75% at the nucleotide level.
• 9.9. At the amino acid level highest conservation is observed at the lipase-binding region (AA 53–73).
• 10.10. Rabbit enzyme also retained the N-terminal pentapeptide of it preform.
• 11.11. The regions of homology and conservation may aid to define the sites of interaction of colipase with lipase.

     

Breeding and moulting fasts in macaroni penguins: Do birds exhaust their fat reserves?

• 1.1. Plasma concentrations of urea, uric acid and total lipid were compared in pre- and late-fast breeding and moulting macaroni penguins (Eudyptes chrysolophus) to test the hypothesis that birds exhaust their lipid reserves and initiate marked protein utilisation towards the end of natural fasts.
• 2.2. Male and female macaroni penguins fasted for a minimum of 29–32 days and 20 days during the breeding and moult fasts, and the difference in body weight over the sample period (reflecting body weight loss) was 31–34% and 41–47%, respectively.
• 3.3. There was no significant increase in plasma urea or uric acid at the end of either fast, nor any decrease in plasma lipid concentrations compared to pre-fast birds.
• 4.4. These results suggest that macaroni penguins continue to rely mainly on lipid reserves during the later stages of natural fasts. This is consistent with post-fast body composition data for other small penguin species.

     

Superoxide dismutase,reduced glutathione and TBA-reactive products in erythrocytes of patients with multiple sclerosis

• 1.1. Superoxide dismutase, reduced glutathione and lipid peroxides levels were determined in the erythrocytes of multiple sclerosis patients.
• 2.2. Superoxide dismutase activity and the malonyldialdehyde production rate were found to be significantly enhanced.
• 3.3. The isoelectric focusing pattern of Superoxide dismutase from multiple sclerosis and normal subjects erythrocytes was substantially overlapping.
• 4.4. Our results indicate the occurrence of a higher susceptibility of multiple sclerosis erythrocytes to lipid peroxidation.