Ricinus: A plant genus of the family EUPHORBIACEAE, order Euphorbiales, subclass Rosidae. The seed of Ricinus communis L. is the CASTOR BEAN which is the source of CASTOR OIL; RICIN; and other lectins.Ixodes: The largest genus of TICKS in the family IXODIDAE, containing over 200 species. Many infest humans and other mammals and several are vectors of diseases such as LYME DISEASE, tick-borne encephalitis (ENCEPHALITIS, TICK-BORNE), and KYASANUR FOREST DISEASE.Castor Bean: Common name for Ricinus communis, a species in the family EUPHORBIACEAE. It is the source of CASTOR OIL.Nymph: The immature stage in the life cycle of those orders of insects characterized by gradual metamorphosis, in which the young resemble the imago in general form of body, including compound eyes and external wings; also the 8-legged stage of mites and ticks that follows the first moult.Tick Infestations: Infestations with soft-bodied (Argasidae) or hard-bodied (Ixodidae) ticks.Arachnid Vectors: Members of the class Arachnida, especially SPIDERS; SCORPIONS; MITES; and TICKS; which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Plant Lectins: Protein or glycoprotein substances of plant origin that bind to sugar moieties in cell walls or membranes. Some carbohydrate-metabolizing proteins (ENZYMES) from PLANTS also bind to carbohydrates, however they are not considered lectins. Many plant lectins change the physiology of the membrane of BLOOD CELLS to cause agglutination, mitosis, or other biochemical changes. They may play a role in plant defense mechanisms.Anaplasma phagocytophilum: A species of gram-negative bacteria in the genus ANAPLASMA, family ANAPLASMATACEAE, formerly called Ehrlichia phagocytophila or Ehrlichia equi. This organism is tick-borne (IXODES) and causes disease in horses and sheep. In humans, it causes human granulocytic EHRLICHIOSIS.Tick-Borne Diseases: Bacterial, viral, or parasitic diseases transmitted to humans and animals by the bite of infected ticks. The families Ixodidae and Argasidae contain many bloodsucking species that are important pests of man and domestic birds and mammals and probably exceed all other arthropods in the number and variety of disease agents they transmit. Many of the tick-borne diseases are zoonotic.Babesia: A genus of tick-borne protozoan parasites that infests the red blood cells of mammals, including humans. There are many recognized species, and the distribution is world-wide.Borrelia burgdorferi Group: Gram-negative helical bacteria, in the genus BORRELIA, that are the etiologic agents of LYME DISEASE. The group comprises many specific species including Borrelia afzelii, Borellia garinii, and BORRELIA BURGDORFERI proper. These spirochetes are generally transmitted by several species of ixodid ticks.Lectins: Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.Anaplasmataceae: A family of bacteria which inhabit RED BLOOD CELLS and cause several animal diseases.Babesia microti: A species of protozoa infecting humans via the intermediate tick vector IXODES scapularis. The other hosts are the mouse PEROMYSCUS leucopus and meadow vole MICROTUS pennsylvanicus, which are fed on by the tick. Other primates can be experimentally infected with Babesia microti.Ricin: A protein phytotoxin from the seeds of Ricinus communis, the castor oil plant. It agglutinates cells, is proteolytic, and causes lethal inflammation and hemorrhage if taken internally.Ticks: Blood-sucking acarid parasites of the order Ixodida comprising two families: the softbacked ticks (ARGASIDAE) and hardbacked ticks (IXODIDAE). Ticks are larger than their relatives, the MITES. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many TICK-BORNE DISEASES, including the transmission of ROCKY MOUNTAIN SPOTTED FEVER; TULAREMIA; BABESIOSIS; AFRICAN SWINE FEVER; and RELAPSING FEVER. (From Barnes, Invertebrate Zoology, 5th ed, pp543-44)Plants, Toxic: Plants or plant parts which are harmful to man or other animals.PolandBabesiosis: A group of tick-borne diseases of mammals including ZOONOSES in humans. They are caused by protozoa of the genus BABESIA, which parasitize erythrocytes, producing hemolysis. In the U.S., the organism's natural host is mice and transmission is by the deer tick IXODES SCAPULARIS.Lyme Disease: An infectious disease caused by a spirochete, BORRELIA BURGDORFERI, which is transmitted chiefly by Ixodes dammini (see IXODES) and pacificus ticks in the United States and Ixodes ricinis (see IXODES) in Europe. It is a disease with early and late cutaneous manifestations plus involvement of the nervous system, heart, eye, and joints in variable combinations. The disease was formerly known as Lyme arthritis and first discovered at Old Lyme, Connecticut.Castor Oil: Oil obtained from seeds of Ricinus communis that is used as a cathartic and as a plasticizer.Borrelia: A genus of gram-negative, anaerobic, helical bacteria, various species of which produce RELAPSING FEVER in humans and other animals.Ehrlichiosis: A tick-borne disease characterized by FEVER; HEADACHE; myalgias; ANOREXIA; and occasionally RASH. It is caused by several bacterial species and can produce disease in DOGS; CATTLE; SHEEP; GOATS; HORSES; and humans. The primary species causing human disease are EHRLICHIA CHAFFEENSIS; ANAPLASMA PHAGOCYTOPHILUM; and Ehrlichia ewingii.Encephalitis, Tick-Borne: Encephalitis caused by neurotropic viruses that are transmitted via the bite of TICKS. In Europe, the diseases are caused by ENCEPHALITIS VIRUSES, TICK-BORNE, which give rise to Russian spring-summer encephalitis, central European encephalitis, louping ill encephalitis, and related disorders. Powassan encephalitis occurs in North America and Russia and is caused by the Powassan virus. ASEPTIC MENINGITIS and rarely encephalitis may complicate COLORADO TICK FEVER which is endemic to mountainous regions of the western United States. (From Joynt, Clinical Neurology, 1996, Ch26, pp14-5)Rickettsia: A genus of gram-negative, aerobic, rod-shaped bacteria often surrounded by a protein microcapsular layer and slime layer. The natural cycle of its organisms generally involves a vertebrate and an invertebrate host. Species of the genus are the etiological agents of human diseases, such as typhus.Encephalitis Viruses, Tick-Borne: A subgroup of the genus FLAVIVIRUS that causes encephalitis and hemorrhagic fevers and is found in eastern and western Europe and the former Soviet Union. It is transmitted by TICKS and there is an associated milk-borne transmission from viremic cattle, goats, and sheep.Arthropod Vectors: Arthropods, other than insects and arachnids, which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Ricinoleic Acids: Eighteen carbon fatty acids that comprise the great majority of CASTOR OIL, which is from the seed of RICINUS.Anaplasmataceae Infections: Infections with bacteria of the family ANAPLASMATACEAE.Dermacentor: A widely distributed genus of TICKS, in the family IXODIDAE, including a number that infest humans and other mammals. Several are vectors of diseases such as TULAREMIA; ROCKY MOUNTAIN SPOTTED FEVER; COLORADO TICK FEVER; and ANAPLASMOSIS.Disease Reservoirs: Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.Ehrlichia: Small, often pleomorphic, coccoid to ellipsoidal organisms occurring intracytoplasmically in circulating LYMPHOCYTES. They are the etiologic agents of tick-borne diseases of humans; DOGS; CATTLE; SHEEP; GOATS; and HORSES.Deer: The family Cervidae of 17 genera and 45 species occurring nearly throughout North America, South America, and Eurasia, on most associated continental islands, and in northern Africa. Wild populations of deer have been established through introduction by people in Cuba, New Guinea, Australia, New Zealand, and other places where the family does not naturally occur. They are slim, long-legged and best characterized by the presence of antlers. Their habitat is forests, swamps, brush country, deserts, and arctic tundra. They are usually good swimmers; some migrate seasonally. (Walker's Mammals of the World, 5th ed, p1362)Nitrate Reductase (NADH): An NAD-dependent enzyme that catalyzes the oxidation of nitrite to nitrate. It is a FLAVOPROTEIN that contains IRON and MOLYBDENUM and is involved in the first step of nitrate assimilation in PLANTS; FUNGI; and BACTERIA. It was formerly classified as EC 1.6.6.1.Receptors, Mitogen: Glycoprotein molecules on the surface of B- and T-lymphocytes, that react with molecules of antilymphocyte sera, lectins, and other agents which induce blast transformation of lymphocytes.Borrelia burgdorferi: A specific species of bacteria, part of the BORRELIA BURGDORFERI GROUP, whose common name is Lyme disease spirochete.Forestry: The science of developing, caring for, or cultivating forests.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Arvicolinae: A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.Borrelia Infections: Infections with bacteria of the genus BORRELIA.Slovakia: Created 1 January 1993 as a result of the division of Czechoslovakia into the Czech Republic and Slovakia.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Rodent Diseases: Diseases of rodents of the order RODENTIA. This term includes diseases of Sciuridae (squirrels), Geomyidae (gophers), Heteromyidae (pouched mice), Castoridae (beavers), Cricetidae (rats and mice), Muridae (Old World rats and mice), Erethizontidae (porcupines), and Caviidae (guinea pigs).Wheat Germ Agglutinins: Lectins purified from the germinating seeds of common wheat (Triticum vulgare); these bind to certain carbohydrate moieties on cell surface glycoproteins and are used to identify certain cell populations and inhibit or promote some immunological or physiological activities. There are at least two isoforms of this lectin.Ixodidae: A family of hardbacked TICKS, in the subclass ACARI. Genera include DERMACENTOR and IXODES among others.Czechoslovakia: Created as a republic in 1918 by Czechs and Slovaks from territories formerly part of the Austro-Hungarian Empire. The country split into the Czech Republic and Slovakia 1 January 1993.Acaricides: A pesticide or chemical agent that kills mites and ticks. This is a large class that includes carbamates, formamides, organochlorines, organophosphates, etc, that act as antibiotics or growth regulators.Bartonella Infections: Infections by the genus BARTONELLA. Bartonella bacilliformis can cause acute febrile anemia, designated Oroya fever, and a benign skin eruption, called verruga peruana. BARTONELLA QUINTANA causes TRENCH FEVER, while BARTONELLA HENSELAE is the etiologic agent of bacillary angiomatosis (ANGIOMATOSIS, BACILLARY) and is also one of the causes of CAT-SCRATCH DISEASE in immunocompetent patients.Spirochaetales: An order of slender, flexuous, helically coiled bacteria, with one or more complete turns in the helix.Receptors, Concanavalin A: Glycoprotein moieties on the surfaces of cell membranes that bind concanavalin A selectively; the number and location of the sites depends on the type and condition of the cell.Concanavalin A: A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.Ectoparasitic Infestations: Infestations by PARASITES which live on, or burrow into, the surface of their host's EPIDERMIS. Most ectoparasites are ARTHROPODS.Galactosides: Glycosides formed by the reaction of the hydroxyl group on the anomeric carbon atom of galactose with an alcohol to form an acetal. They include both alpha- and beta-galactosides.Galactose: An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.Mistletoe: Parasitic plants that form a bushy growth on branches of host trees which are in the order Santalales. It includes the Christmas mistletoe family (VISCACEAE), the showy mistletoe family (LORANTHACEAE) and the catkin mistletoe family (Eremolepidaceae). The composition of toxins, lectins, tyramine, phenethylamines, and other compounds may be affected by the host.Glossitis, Benign Migratory: An idiopathic disorder characterized by the loss of filiform papillae leaving reddened areas of circinate macules bound by a white band. The lesions heal, then others erupt.Bites and StingsAnaplasma: A genus of gram-negative bacteria whose organisms are obligate parasites of vertebrates. Species are transmitted by arthropod vectors with the host range limited to ruminants. Anaplasma marginale is the most pathogenic species and is the causative agent of severe bovine anaplasmosis.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Umbelliferones: 7-Hydroxycoumarins. Substances present in many plants, especially umbelliferae. Umbelliferones are used in sunscreen preparations and may be mutagenic. Their derivatives are used in liver therapy, as reagents, plant growth factors, sunscreens, insecticides, parasiticides, choleretics, spasmolytics, etc.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Jatropha: A plant genus of the family EUPHORBIACEAE. Members contain jatrophone and other diterpenes.Nymphaea: A plant genus of the family NYMPHAEACEAE. The common name of lotus is also used for LOTUS and NELUMBO.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Rodentia: A mammalian order which consists of 29 families and many genera.Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.Bartonella: A genus of gram-negative bacteria characteristically appearing in chains of several segmenting organisms. It occurs in man and arthropod vectors and is found only in the Andes region of South America. This genus is the etiologic agent of human bartonellosis. The genus Rochalimaea, once considered a separate genus, has recently been combined with the genus Bartonella as a result of high levels of relatedness in 16S rRNA sequence data and DNA hybridization data.SwitzerlandSalivary Proteins and Peptides: Proteins and peptides found in SALIVA and the SALIVARY GLANDS. Some salivary proteins such as ALPHA-AMYLASES are enzymes, but their composition varies in different individuals.GermanyBartonella henselae: A species of gram-negative bacteria that is the etiologic agent of bacillary angiomatosis (ANGIOMATOSIS, BACILLARY). This organism can also be a cause of CAT-SCRATCH DISEASE in immunocompetent patients.Alphaproteobacteria: A class in the phylum PROTEOBACTERIA comprised mostly of two major phenotypes: purple non-sulfur bacteria and aerobic bacteriochlorophyll-containing bacteria.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Muridae: A family of the order Rodentia containing 250 genera including the two genera Mus (MICE) and Rattus (RATS), from which the laboratory inbred strains are developed. The fifteen subfamilies are SIGMODONTINAE (New World mice and rats), CRICETINAE, Spalacinae, Myospalacinae, Lophiomyinae, ARVICOLINAE, Platacanthomyinae, Nesomyinae, Otomyinae, Rhizomyinae, GERBILLINAE, Dendromurinae, Cricetomyinae, MURINAE (Old World mice and rats), and Hydromyinae.Salivary Glands: Glands that secrete SALIVA in the MOUTH. There are three pairs of salivary glands (PAROTID GLAND; SUBLINGUAL GLAND; SUBMANDIBULAR GLAND).Czech Republic: Created 1 January 1993 as a result of the division of Czechoslovakia into the Czech Republic and Slovakia.Ribosome Inactivating Proteins: N-Glycosidases that remove adenines from RIBOSOMAL RNA, depurinating the conserved alpha-sarcin loop of 28S RIBOSOMAL RNA. They often consist of a toxic A subunit and a binding lectin B subunit. They may be considered as PROTEIN SYNTHESIS INHIBITORS. They are found in many PLANTS and have cytotoxic and antiviral activity.Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Insect Bites and Stings: Bites and stings inflicted by insects.Glycoconjugates: Carbohydrates covalently linked to a nonsugar moiety (lipids or proteins). The major glycoconjugates are glycoproteins, glycopeptides, peptidoglycans, glycolipids, and lipopolysaccharides. (From Biochemical Nomenclature and Related Documents, 2d ed; From Principles of Biochemistry, 2d ed)Larva: Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.Ribosome Inactivating Proteins, Type 2: Ribosome inactivating proteins consisting of two polypeptide chains, the toxic A subunit and a lectin B subunit, linked by disulfide bridges. The lectin portion binds to cell surfaces and facilitates transport into the ENDOPLASMIC RETICULUM.

Lectins as membrane components of mitochondria from Ricinus communis. (1/117)

1. Mitochondria were isolated from developing endosperm of Ricinus communis and were fractionated into outer membrane and inner membrane. The relative purity of the two membrane fractions was determined by marker enzymes. The fractions were also examined by negative-stain electron microscopy. 2. Membrane fractions were sequentially extracted in the following way. (a) Suspension in 0.5M-potassium phosphate, pH7.1; (b)suspension in 0.1M-EDTA (disodium salt)/0.05M-potassium phosphate, pH7.1; (c) sonication in 0.05M-potassium phosphate, pH7.1;(d)sonication in aq. Triton X-100 (0.1%). The membranes were pelleted by centrifugation at 100 000g for 15 min, between each step. Agglutination activity in the extracts was investigated by using trypsin-treated rabbit erythrocytes. 3. The addition of lactose to inner mitochondrial membrane resulted in the solubilization of part of the lectin activity, indicating that the protein was attached to the membrane via its carbohydrate-binding site. Pretreatment of the membranes with lactose before tha usual extraction procedure showed that lactose could extract lectins that normally required more harsh treatment of the membrane for solubilization. 4. Lectins extracted from inner membranes were purified by affinity chromatography on agarose gel. Polyacrylamide-gel electrophoresis of purified samples in sodium dodecyl sulphate indicated that at least part of the lectin present in inner mitochondrial membrane was identical with the R. communis agglutinin of mol.wt. 120 000.  (+info)

Expression of Ricinus communis receptors on epithelial cells in oral carcinomas and oral wounds. (2/117)

The histological distribution of receptors for Ricinus communis Fraction 1 (RCA1) in oral carcinomas and in oral epithelial cells during wound healing has been studied by use of fluorescein-tagged RCA1. Biopsies from 15 human oral carcinomas and adjacent normal mucosa showed RCA1 receptors at the cell membranes in the basal and spinous layer of the normal epithelium, whereas receptors could not be demonstrated in invading islands of the tumors. In healing oral wounds from eight humans and three monkeys, RCA1 receptors were demonstrated both in normal epithelium adjacent to the wounds and in the epithelial outgrowth from the wound margin. Titrations, however, showed that the epithelial outgrowth reacted more weakly than did the normal adjacent epithelium. These results support previous in vitro studies showing changes in carbohydrate composition of moving normal cells and of malignant cells, a finding that may be of interest in relation to formation of metastases.  (+info)

Nitrate reductases from leaves of Ricinus (Ricinus communis L.) and spinach (Spinacia oleracea L.) have different regulatory properties. (3/117)

The activity of nitrate reductase (+Mg(2+), NR(act)) in illuminated leaves from spinach, barley and pea was 50-80% of the maximum activity (+EDTA, NR(max)). However, NR from leaves of Ricinus communis L. had a 10-fold lower NR(act), while NR(max) was similar to that in spinach leaves. The low NR(act) of Ricinus was independent of day-time and nitrate nutrition, and varied only slightly with leaf age. Possible factors in Ricinus extracts inhibiting NR were not found. NR(act) from Ricinus, unlike the spinach enzyme, was very low at pH 7.6, but much higher at more acidic pH with a distinct maximum at pH 6.5. NR(max) had a broad pH response profile that was similar for the spinach and the Ricinus enzyme. Accordingly, the Mg(2+)-sensitivity of NR from Ricinus was strongly pH-dependent (increasing sensitivity with increasing pH), and as a result, the apparent activation state of NR from a Ricinus extract varied dramatically with pH and Mg(2+)concentration. Following a light-dark transition, NR(act) from Ricinus decreased within 1 h by 40%, but this decrease was paralleled by NR(max). In contrast to the spinach enzyme, Ricinus-NR was hardly inactivated by incubating leaf extracts with ATP plus okadaic acid. A competition analysis with antibodies against the potential 14-3-3 binding site around ser 543 of the spinach enzyme revealed that Ricinus-NR contains the same site. Removal of 14-3-3 proteins from Ricinus-NR by anion exchange chromatography, activated spinach-NR but caused little if any activation of Ricinus-NR. It is suggested that Mg(2+)-inhibition of Ricinus-NR does not require 14-3-3 proteins. The rather slow changes in Ricinus-NR activity upon a light/dark transient may be mainly due to NR synthesis or degradation.  (+info)

Ultrastructural localization of lectin-binding sites on the zonae pellucidae and plasma membranes of mammalian eggs. (4/117)

Receptors for Ricinus communis agglutinin I (RCAI), concanavalin A (Con A), and wheat germ agglutinin (WGA) were localized on the zonae pellucidae and plasma membranes of hamster, mouse, and rat eggs with ferritin-lectin conjugates. Intact eggs labeled with the ferritin conjugates showed dense concentrations of RCAI and WGA receptors in the outermost regions of their zonae pellucidae and sparse distributions of Con A receptors throughout the zonae. Ferritin-lectin labeling was specific, since inhibitory saccharides effectively blocked labeling. The asymmetric density of RCAI receptors across the zona was confirmed by ferritin-RCAI and fluorescein-RCAI labeling of mechanically isolated zonae pellucidae, indicating that the RCAI-binding sites are more densely distributed in the exterior zona regions. Plasma membranes of rodent eggs contained RCAI, WGA, and Con A receptors. These receptors were found to be more or less randomly distributed on surfaces of aldehyde-fixed eggs or on eggs labeled near 0 degrees C. However, eggs incubated at 25 degrees C showed aggregated WGA- and Con A-binding site distributions on their plasma membranes. This indicates that lectin-induced receptor redistribution occurs at this temperature. The possibility that plasma membrane receptor mobility is a requirement for sperm-egg fusion is discussed.  (+info)

Leaf development in Ricinus communis during drought stress: dynamics of growth processes, of cellular structure and of sink-source transition. (5/117)

Dicot leaf growth is characterized by partly transient tip-to-base gradients of growth processes, structure and function. These gradients develop dynamically and interact with dynamically developing stress conditions like drought. In Ricinus communis plants growing under well-watered and drought conditions growth rates peaked during the late night and minimal values occurred in the late afternoon. During this diurnal course the leaf base always showed much higher rates than the leaf tip. The amplitude of this diurnal course decreased when leaves approached maturity and during drought stress without any significant alteration of the diurnal pattern and it increased during the first days after rewatering. Unique relationships between leaf size and cytological structure were observed. This provided the framework for the analysis of changes in assimilation, transpiration and dark respiration, chlorophyll, protein, carbohydrate, and amino acid concentrations, and of activities of sink-source-related enzymes at the leaf tip and base during leaf development in well-watered and drought-stressed plants. Gas exchange was dominated by physiological rather than by anatomical properties (stomatal density). Tip-to-base gradients in carbohydrate concentrations per dry weight and sink-source-related enzymes were absent, whereas significant gradients were found in amino acid concentrations per dry weight. During drought stress, growing leaves developed source function at smaller leaf size, before specific physiological adaptations to drought occurred. The relevance of the developmental status of individual leaves for the drought-stress response and of the structural changes for the biochemical composition changes is discussed.  (+info)

Characterization of group N streptococcus lipoteichoic acid. (6/117)

Lipoteichoic acid was extracted from the group N organism Streptococcus lactis ATCC 9936 with hot aqueous phenol and purified by gel chromatography followed by affinity chromatography using Ricinus communis lectin as the specific absorbent. The teichoic acid moiety of the lipoteichoic acid was calculated to contain 16 to 17 glycerol phosphate units, approximately half of which were substituted with alpha-D-galactosyl residues; the glycolipid moiety contained O-alpha-D-glucosyl-1 yields 2-O-alpha-D-glucosyl-1 yields 1-glycerol. The finding of 2-O-alpha-D-galactosyl glycerol in the lipid fraction of hydrofluoric acid hydrolysates suggests that fatty acids also occur as substituents on the main chain of the lipoteichoic acid. The reactivity of the lipoteichoic acid with R. communis lectin was studied by the quantitative precipitin method and compared with the reactivity of Lactobacillus fermenti lipoteichoic acid, which has a lower degree of alpha-D-galactosyl substitution. Group N antiserum reacted strongly with the S. lactis lipoteichoic acid and cross-reacted with L. fermenti lipoteichoic acid. From inhibition studies it is concluded that the antibodies are specific for alpha-D-galactosyl substituents. In addition to lipoteichoic acid, a fraction was obtained by gel chromatography which contained galactose and reacted with group N antiserum but could be distinguished from the lipoteichoic acid by immunoelectrophoresis.  (+info)

The ricinosomes of senescing plant tissue bud from the endoplasmic reticulum. (7/117)

The ricinosome (synonym, precursor protease vesicle) is a novel organelle, found so far exclusively in plant cells. Electron microscopic studies suggest that it buds off from the endoplasmic reticulum in senescing tissues. Biochemical support for this unusual origin now comes from the composition of the purified organelle, which contains large amounts of a 45-kDa cysteine endoprotease precursor with a C-terminal KDEL motif and the endoplasmic reticulum lumen residents BiP (binding protein) and protein disulfide isomerase. Western blot analysis, peptide sequencing, and mass spectrometry demonstrate retention of KDEL in the protease proform. Acidification of isolated ricinosomes causes castor bean cysteine endopeptidase activation, with cleavage of the N-terminal propeptide and the C-terminal KDEL motif. We propose that ricinosomes accumulate during senescence by programmed cell death and are activated by release of protons from acidic vacuoles.  (+info)

Lipolytic activity of ricin from Ricinus sanguineus and Ricinus communis on neutral lipids. (8/117)

The present study was carried out with a view of determining ricin lipolytic activity on neutral lipids in emulsion and in a membrane-like model. Using 2,3-dimercapto-1-propanol tributyrate (BAL-TC(4)) as substrate, the lipolytic activity of ricin was found to be proportional to ricin and substrate concentrations, with an apparent K(m) (K(m,app)) of 2.4 mM, a k(cat) of 200 min(-1) and a specific activity of 1.0 unit/mg of protein. This work was extended to p-nitrophenyl (pNP) fatty acid esters containing two to twelve carbon atoms. Maximum lipolytic activity was registered on pNP decanoate (pNPC(10)), with a K(m,app) of 3.5 mM, a k(cat) of 173 min(-1) and a specific activity of 3.5 units/mg of protein. Ricin lipolytic activity is pH and galactose dependent, with a maximum at pH 7.0 in the presence of 0.2 M galactose. Using the monolayer technique with dicaprin as substrate, ricin showed a lipolytic activity proportional to the ricin concentration at 20 mN/m, which is dependent on the surface pressure of the lipid monolayer and is detectable up to 30 mN/m, a surface pressure that is of the same order of magnitude as that of natural cell membranes. The methods based on pNPC(10) and BAL-TC(4) hydrolysis are simple and reproducible; thus they can be used for routine studies of ricin lipolytic activity. Ricin from Ricinus communis and R. sanguineus were treated with diethyl p-nitrophenylphosphate, an irreversible serine esterase inhibitor, and their lipolytic activities on BAL-TC(4) and pNPC(10), and cytotoxic activity, were concurrently recorded. A reduction in lipolytic activity was accompanied by a decrease in cytotoxicity on Caco2 cells. These data support the idea that the lipolytic activity associated with ricin is relevant to a lipase whose activity is pH and galactose dependent, sensitive to diethyl p-nitrophenylphosphate, and that a lipolytic step may be involved in the process of cell poisoning by ricin. Both colorimetric tests used in this study are sensitive enough to be helpful in the detection of possible lipolytic activities associated with other cytotoxins or lectins.  (+info)

  • Ricinus ticks collected in the natural foci in Russia and Ukraine, having an unusual RFLP Msel-pattern, were studied using sequencing rrfA-rrlB spacer and rrs gene. (prohealth.com)
  • I. ricinus has three active life stages: larva, nymph, and adult (Fig. 1 ), and each requires a single blood meal from a vertebrate host. (wiley.com)
  • Infection of adult I. ricinus ticks on 10 localities fluctuated from 4.0 to 15.0% and over 10% of adult ticks in forests and in some urban and suburban parks of the city Katowice were infected. (aaem.pl)
  • In early summer of 1996, 101 unfed adult I. ricinus ticks were collected by flagging vegetation. (asm.org)
  • Questing nymphal and adult I. ricinus ticks were collected (i) at the edge of a forest in Eberdingen near Stuttgart (Germany), (ii) in an alder marsh outside the village Klasdorf located south of Berlin (Germany), (iii) near the town of Lembach in the northern Vosges region of France, and (iv) on pastured meadows on Madeira Island (Portugal) in 2004 by passing a flannel flag over the vegetation. (asm.org)
  • A new ixodid that had long been confused with Ixodes ricinus is described by the first 2 authors from adult males and females collected from cattle and occasionally from horses in Argentina and Uruguay as I. pararicinus sp. (eurekamag.com)
  • Mice were pluriinfested with nymphs and rabbits, with adult Ixodes ricinus . (springer.com)
  • Brossard M (1982) Rabbits infested with adult Ixodes ricinus L.: effects of mepyramine on acquired resistance. (springer.com)
  • Brossard M, Girardin P (1979) Passive transfer of resistance in rabbits infested with adult Ixodes ricinus L.: humoral factors influence feeding and egg laying. (springer.com)
  • In Europe, the most important hosts of adult female I. ricinus are cervids. (uio.no)
  • Sequencing of a Tick-Borne Encephalitis Virus from Ixodes ricinus Reveals a Thermosensitive RNA Switch Significant for Virus Propagation in Ectothermic Arthropods. (diva-portal.org)
  • In this study we have generated strategies for detection of broad types of tick-borne flaviviruses in pools of I. ricinus sampled in Sweden. (diva-portal.org)
  • This should lead to increased awareness of signs and symptoms compatible with Lyme borreliosis in persons living in or visiting areas where I. ricinus is present. (diva-portal.org)
  • Here, we present data on the prevalence of B. henselae and Lyme disease spirochetes in 654 questing ticks ( I. ricinus ) collected at four locations in Europe, suggesting that ticks might serve as potential vectors for the transmission of B. henselae to humans. (asm.org)
  • We tested the hypotheses that cattle grazing used in woodland management decreases the density of questing I. ricinus, and that it decreases the nympal infection prevalence of B. burgdorferi sensu lato. (wur.nl)
  • The study examined both in vivo and in vitro response of L. major infection to combined therapy of Ricinus communis and Azadirachta indica extracts in BALB/c mice as the mouse model. (springer.com)
  • The aim of this study was to identify environmental factors influencing questing I. ricinus nymph abundance and B. burgdorferi s.l. infection in questing nymphs using a large-scale survey across Scotland. (gla.ac.uk)
  • The results obtained from the study indicate that I. ricinus larvae feed not only on small or medium animals but also on large animals and they (i.e. roe deer, red deer and wild boars) were the most prevalent in all study areas as the essential hosts for larvae of I. ricinus . (springer.com)
  • Methanolic extracts of the leaves of Ricinus communis were used in antimicrobial testing against eight pathogenic bacteria in rats and showed antimicrobial properties. (wikipedia.org)
  • In this study, the efficacy of immunization with recombinant ferritin 2 and native tick protein extracts (TPEs) against Ixodes ricinus infestations in calves was assessed in two immunization experiments. (frontiersin.org)
  • 50% of sera from these animals reacted against a tick antigen with a molecular weight of 25 kDa, which was detected in total extracts of partially fed I. ricinus females and in tick integumental extract. (springer.com)
  • Sera of I. ricinus -infested rabbits and mice or of rabbits infested with Rhipicephalus appendiculatus adults reacted with a 20-kDa antigen in total extracts of partially fed R. appendiculatus females and the integument of this species. (springer.com)
  • Le ricin ( Ricinus communis L.) est une plante peu exigeante dont la culture offre d'énormes potentialités économiques pour les exploitants agricoles sénégalais. (ajol.info)
  • Previous studies using Southern blots have indicated the presence of multiple copies of the preproricin gene in the Ricinus communis genome and a survey of a 4X draft coverage of the genome shows the presence of seven full length genes, one of which is ricin and six of which are ricin-like proteins (RLP). (georgetown.edu)
  • Larval and nymphal I. ricinus were fed on a B. birtlesii -infected mouse. (plos.org)
  • To test these hypotheses, we compared the densities of questing I. ricinus between twenty pairs of plots in grazed and ungrazed forest areas. (wur.nl)
  • Immunization with native I. ricinus TPEs thus conferred a strong immune response in calves and significantly reduced the feeding success of both nymphs and adults. (frontiersin.org)
  • 1. A cDNA sequence encoding a Ricinus communis β-ketoacyl-ACP synthase protein, wherein said cDNA sequence comprises the mature protein encoding portion of said synthase protein, and wherein said mature protein has a molecular weight of approximately 50 kD. (google.com)
  • This is the first report on an anti-tick vaccine trial on I. ricinus using a protein able to interact with both host immunity and haemostasis, as a vaccinating antigen. (nih.gov)
  • E. Christy Jeyaseelan and P. T. Justin Jashothan, " In vitro control of Staphylococcus aureus (NCTC 6571) and Escherichia coli (ATCC 25922) by Ricinus communis L," Asian Pacific Journal of Tropical Biomedicine , vol. 2, no. 9, pp. 717-721, 2012. (hindawi.com)
  • A. Kadri, N. Gharsallah, M. Damak, and R. Gdoura, "Chemical composition and in vitro antioxidant properties of essential oil of Ricinus communis L ," Journal of Medicinal Plants Research , vol. 5, no. 8, pp. 1466-1470, 2011. (hindawi.com)
  • Blood was collected from the calves before the first and after the second immunization and fed to I. ricinus females and nymphs using an in vitro artificial tick feeding system. (frontiersin.org)
  • An affinity-purified plant lectin from Ricinus communis (RCA II ) was shown to exhibit differential toxicity toward SV40-transformed 3T3 fibroblasts grown in vitro . (aacrjournals.org)
  • Les réponses des accessions ont été évaluées en conditions in vitro sur la base de paramètres morphologiques, biochimiques et de survie des vitroplants. (ajol.info)
  • This master thesis describes the prevalence and genotype composition of B. burgdorferi s.l. in host-seeking I. ricinus ticks at different locations in Scandinavia. (uio.no)
  • The northern limit of I. ricinus and B. burgdorferi s.l. in Sweden corresponds roughly to the northern limit of the southern boreal vegetation zone, and is characterized climatically by snow cover for a mean duration of 150 days and a vegetation period averaging 170 days. (diva-portal.org)
  • The aim of this study was to examine whether the larvae of I. ricinus can transmit B. burgdorferi ( s.l ) and B. miyamotoi to vertebrate hosts. (biomedcentral.com)
  • The geographical distribution of I. ricinus in Sweden was analysed with respect to vegetation zones and climate. (diva-portal.org)
  • The zoogeographical distribution of I. ricinus in Sweden can be classified as southerly-central, with the centre of the distribution south of the Limes Norrlandicus. (diva-portal.org)
  • We measured the presence of I. ricinus tick nymphs at 159 stratified random lowland forest and meadow sites in Denmark, Norway and Sweden by dragging 400 m transects from August to September 2016, representing a total distance of 63.6 km. (eurosurveillance.org)
  • We analysed the spatial distribution of I. ricinus with generalised mixed effects models (GLMMs) based on data from extensive field surveys of questing density in two coastal regions in Norway, from which home range data from 73 red deer with GPS collars were available. (uio.no)
  • Questing I. ricinus density was predicted by several landscape features, such as elevation, distance to the fjord and topographic slope. (uio.no)
  • Dobson A & Randolph SE (2011) Modelling the effects of recent changes in climate, host density and acaricide treatments on population dynamics of Ixodes ricinus in the UK, Journal of Applied Ecology, 48 (4), pp. 1029-1037. (stir.ac.uk)
  • In order to find a host I. ricinus adopts an ambush strategy, known as "questing," that involves climbing up vegetation and waiting to grab on to a passing host. (wiley.com)
  • To find a blood meal, I. ricinus first climbs onto low vegetation to quest for a passing vertebrate host. (biologists.org)
  • The aim of the present study was to appraise the antimicrobial activity of Ricinus communis L. essential oil against different pathogenic microorganisms and the cytotoxic activity against HeLa cell lines. (biomedcentral.com)
  • How might climate change affect I. ricinus host-seeking behavior (questing)? (wiley.com)
  • We hypothesize that, in order to maximize survival, I. ricinus have adapted their questing in response to temperature in accordance with local climates. (wiley.com)
  • Most studies on I. ricinus behaviour have focused on field observations and have been limited to observing questing ticks. (biologists.org)
  • We studied factors governing the alternation of questing and quiescence and the duration of these states by continuously following the behaviours of individual I. ricinus nymphs. (biologists.org)
  • B. henselae DNA was detected in questing Ixodes pacificus and I. persulcatus ticks in North America, Eastern Europe, and Russia, respectively ( 4 , 13 , 14 , 22 , 25 ) and in I. ricinus ticks feeding on people or domestic animals in Central Europe ( 24 , 26 ). (asm.org)
  • of the spotted fever group, in questing Ixodes ricinus ticks, taking into account tick characteristics. (asm.org)
  • The aims of this study were to identify DNA of CNM in small mammals, the ticks parasitizing them and questing ticks in areas with sympatric existence of Ixodes ricinus and Dermacentor reticulatus in Germany. (biomedcentral.com)
  • Blood, transudate and organ samples (spleen, kidney, liver, skin) of 91 small mammals and host-attached ticks from altogether 50 small mammals as well as questing I. ricinus ticks (n=782) were screened with a real-time PCR for DNA of CNM. (biomedcentral.com)
  • In the areas of the Ústí nad Labem Region, Olomouc Region, South Bohemian Region, and Highlands Region, 600 m2 plots were selected in the local optimal I. ricinus habitats where tick flagging was performed every year in the spring-summer and autumn seasons of the tick questing activity. (eurekamag.com)
  • We used a membrane-feeding technique to infect I. ricinus with B. henselae and demonstrate transmission of B. henselae within I. ricinus across developmental stages, migration or multiplication of B. henselae in salivary glands after a second meal, and transmission of viable and infective B. henselae from ticks to blood. (cdc.gov)