Peptides and multiple antigen peptides from Schistosoma mansoni glyceraldehyde 3-phosphate dehydrogenase: preparation, immunogenicity and immunoprotective capacity in C57BL/6 mice.

Four monoepitopic MAPs (MAP A, B, C and E) and one bis-diepitopic MAP B-E derived fromthe primary sequence of Schistosoma mansoni glyceraldehyde 3-phosphate dehydrogenase, previously tested in BALB/c mice, were examined for their immunogenicity and protective capacity in C57BL/6 mice. Despite multimerization into MAPs, MAP Aand MAP C were poorly immunogenic. In contrast toBALB/c mice, MAP E was non-immunogenic in C57BL/6 mice. Peptide B in the form of MAP B orbis-diepitopic MAPB-E elicited immune responses in C57BL/6 mice that were associated with a significant decrease in worm burden. The MAPs were prepared by the stepwise solid-phase peptide synthesis using Boc/Bzl chemistry, successfully purified on the RP-HPLC column and characterized by RP-HPLC, HPCE and MALDI-TOF MS techniques. A general strategy for MAPs purification is discussed here and the purification of MAP Band MAP E is documented in detail.     

Renal excretion capacity in hydrated desert rodents (Jaculus orientalis andJaculus deserti)

Summary The capacity to excrete a water load was studied in rats and in two desert rodents (Jaculus orientalis andJaculus deserti) adapted to either 5 or 30°C ambient temperature. The rat is able to eliminate the entire water load regardless of thermal adaptation. Cold-adaptedJ. orientalis andJ. deserti excreted 60% of the water load in comparison to 20–30% in warm-adapted jerboas.At both adaptation temperatures, antidiuretic hormone (ADH) concentration was estimated at maximum diuresis in the two desert species. Though hydration induced a significant decrease in ADH concentration in both species, its level in the plasma remained relatively high. The decrease was more pronounced inJ. orientalis thanJ. deserti.Abbreviation ADH antidiuretic hormone     

Identification of the 5-HT1A Receptor Binding Subunit in Rat Brain Membranes Using the Photoaffinity Probe [3H]8-Methoxy-2-[N-n-Propyl, N-3-(2-Nitro-4-Azidophenyl)Aminopropyl]Aminotetralin

The synthesis of a tritiated derivative of the 5-HT1A photoaffinity probe 8-methoxy-2-[N-n-propyl, N-3-(2-nitro-4-azidophenyl)aminopropyl]aminotetralin ([3H]8-methoxy-3'-NAP-amino-PAT) allowed the use of this probe for attempting the irreversible labeling of specific binding sites in rat brain membranes. Sodium dodecyl-sulfate-polyacrylamide gel electrophoresis of proteins solubilized from hippocampal microsomal membranes that had been incubated with 20 nM [3H]8-methoxy-3'-NAP-amino-PAT under UV light revealed a marked incorporation of 3H label into a 63-kilodalton protein termed PI. As expected of a possible correspondence between PI and 5-HT1A receptor binding sites, 3H labeling by the photoaffinity probe could be prevented by selective 5-HT1A ligands such as 8-hydroxy-2-(di-n-propylamino)tetralin, ipsapirone, buspirone, and gepirone and by N-ethylmaleimide, but not by the 5-HT2 antagonist ketanserin, noradrenaline- and dopamine-related drugs, monoamine oxidase inhibitors, and chlorimipramine. Furthermore, the regional and subcellular distributions of PI were identical to those of specific 5-HT1A binding sites. These results indicated that the binding subunit of the 5-HT1A receptor is a 63-kilodalton protein with a functionally important sulfhydryl group(s).     

Induction of androgenesisin vitro in various genetic forms ofSecale cereale

Six thousand anthers ofSecale cereale cv. Dańkowskie Zlote and inbred lines L214 L215 and L258c/5, in the uninuclear microspore were cultured over a period of three months on Murashige and Skoog nutrient medium supplemented with IAA (1–2μg1⁻¹), kinetin (0.2 to (1.0μg1⁻¹) and 2,4-D (0.5–2.0μg1⁻¹). First divisions of microspore were observed after 7 days. In the course of 10 weeks, 4 albino tic embryos at the cotyledon stage were observed that died away in the course of further culture. The course of androgenesis was regular in inbred lines and irregular in rye cv. Dańkowskie Ziote. The efficiency of androgenesis and the amount of observed globular structures in anthers were also dependent on the genetic potency of the material. Inbred lines did not show any greater viability of embryos.     

Fine structure of muscles in the tickHyalomma (Hyalomma) dromedarii (Ixodoidea: Ixodidae)

Skeletal and visceral muscles are distinguished in the unfed nymphHyalomma (Hyalomma) dromedarii according to position, structure and function. The skeletal muscles include the capitulum, dorsoventral and leg oblique muscles. Their muscle fibres have the striated pattern of successive sarcomeres whose thick myosin filaments are surrounded by orbitals of up to 12 thin actin filaments. The cell membrane invaginates into tubular system (T) extending deeply into the sarcoplasm and closely associated to cisternae of sarcoplasmic reticulum (SR). The T and SR forming two-membered dyads are considered to be the main route of calcium ions whose movements are synchronized with the motor impulse to control contraction and relaxation in most muscles. Two types of skeletal muscle fibres are recognized, and are suggested as representing different physiological phases.In the visceral-muscle fibres investing tick internal organs, the actin and myosin filaments are slightly interrupted, and the T and SR are well demonstrated. Both skeletal and visceral muscles are invaginated by tracheoles and innervated by nerve-axons containing synaptic vesicles.     

Motile aeromonas infection of striped (grey) mullet Mugil cephalus

Infection of striped mullet (Mugil cephalus) with Aeromonas hydrophila results in an acute septicemic disease. The disease can be experimentally induced by intramuscular injection, skin or gill scarification or by the oral route using pellets purposely seeded with bacteria. The organism was isolated from the blood 1–2 days after infection and from all organs 24 hr or longer after infection. The disease is characterized by early inflammatory and proliferative changes and later necrotic changes. Enteritis and hepatic necrosis are constant findings in aeromonad disease of M. cephalus but surface lesions are not pathognomic for these infections in mullet. Death of infected fish may be attributed to bacterial toxins which cause necrosis of parenchymal organs and soft tissue structure.     

Metabolic activities of the sugarbeet pathogens Fusarium solani (Mart.) Sacc. and Sclerotium rolfsii Sacc. under pyramin stress

Effects of different concentrations of active ingredient of the herbicide pyramin on metabolic activities of Fusarium solani and Sclerotium rolfsii were examined. High concentrations of this herbicide (1000 and 2000 g mL^-1 for F. solani and 100 and 200 g mL^-1 for S. rolfsii) had inhibitory effects on the metabolic activities of both fungi. These were demonstrated by significant decreases in growth, and increases in rates of CO₂ evolved, O₂ consumed and keto acids produced. These were accompanied by increased rates of sugar, nitrate and inorganic phosphorus absorption as well as lowered rates of synthesis of carbohydrates and insoluble nitrogenous (including protein) and phosphorus (including RNA-P and DNA-P) compounds. In addition, rates of excretion of both nitrogen and phosphorus fractions by the mycelial mats were increased.A concentration of 25 g mL^-1 exerted little or no effect on the metabolic activities of these fungi, although S. rolfsii was somewhat sensitive to this concentration.     

A bacteriological survey of an oyster-growing area: The Oualidia Lagoon,Morocco

A 3-year bacteriological survey of an oyster-growing area in Morocco, where the Japanese oyster (Crassostrea gigas) is grown, showed that the contamination of this lagunar ecosystem was not continuous but intermittent and that animal manure and human recreational activities were important sources of pollution. The major source of contamination was of animal origin, except during the summer, when human contamination prevailed.     

Uptake of ferrous iron histidinate, a promoter of lipid peroxidation, by Ehrlich ascites tumor cells

The kinetics of the uptake of Fe(II)-histidinate, a known promoter of lipid peroxidation, into Ehrlich ascites tumor (EAT) cells and the intracellular binding of iron were studied in vitro. EAT cells (27.10(6)/ml) were incubated in Hanks' balanced salts solution at 37 degrees C for various time intervals in the presence of FeSO4 (1 mM) and L-histidine (10 mM). Total iron was determined by the 1,10-phenanthroline/ascorbate method and ferric iron by reaction with 5-sulfosalicylic acid; the difference was ascribed to ferrous iron. Total iron decreased rapidly in the medium (242 nmol within the first 10 min), and a corresponding increase of total iron (saturation value 376 nmol after 60 min) was determined within the cells, after the cellular proteins had been solubilized with 6 M urea. In the absence of EAT cells, Fe(II)-histidinate was readily oxidized to Fe(III)-histidinate by oxygen, but this reaction was strongly retarded by the tumor cells. The uptake of iron histidinate occurred in the oxidized state, while an uptake of ferrous iron could not be proven unambiguously. When EAT cells were saturated with iron, it was found that 93% of intracellular iron was bound to water-insoluble proteins and 7% was associated with soluble proteins, while no unbound iron was detectable by the method used. It was concluded that, despite the high uptake of total iron, only a very small portion of the intracellular iron was available as a redox catalyst for lipid peroxidation.     

Specific inhibition of human granulocyte elastase with peptide aldehydes

The kinetic features of human granulocyte elastase, chymotrypsin, porcine pancreatic elastase and elastomucoproteinase were compared. Amino acyl ester substrates were assayed and Km and kcat values were defined. Aldehyde analogues of the p-nitroanilide substrates designed for granulocyte elastase as optimal for Km appeared to be potent inhibitors. Suc-D-Phe-Pro-valinal (Ki = 40 microM) was found to inhibit granulocyte elastase competitively and specifically when measured with synthetic substrates, and the Ki was 3 microM with the natural protein substrate, elastin.