Datura stramonium poisoning in children. (25/46)

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Chronic effect of datura (seed) extract on the brain of albino rats. (26/46)

The effect of chronic treatment with datura (seed) extract was studied to investigate its effect on the energy metabolism and peroxidative activities in the brain of rats. Datura treatment was found to cause an increase in the activity of brain lipid peroxidase and catalase, while it caused a decrease in the activity of fructose diphosphate aldolase and glucose 6-phosphate dehydrogenase enzyme. A marked reduction was noted in the protein, DNA and RNA contents of datura administered rats.  (+info)

Tissue and subcellular distribution of the lectin from Datura stramonium (thorn apple). (27/46)

Plants of Datura stramonium (thorn-apple) were dissected into their component tissues and examined for the presence of the Datura lectin. This lectin was easily detected in seeds and in various parts of the flowers of adult plants. Traces were also found in green (emerged) cotyledons and roots of seedlings. The specific lectin activity in seeds contained within the fruits increased as the seeds matured. Mature seeds were homogenized in sucrose and separated by differential centrifugation into four fractions, three of which were clearly of distinct composition. Most of the lectin activity sedimented with the low-speed (cell-wall/protein-body) pellet, but a similar specific activity was recovered from the other fractions. However, if EDTA was included in the homogenization medium, three or four times more lectin activity was recovered in the soluble fraction. Immunofluorescent staining of formaldehyde-fixed sections showed that the lectin was localized in the cytoplasm, with little associated with cell walls. The possible relevance of these results to the function of the lectin in plant cells is discussed.  (+info)

Isolation of the tumor-inducing RNA from oncogenic and nononcogenic Agrobacterium tumefaciens. (28/46)

Two RNA fractions have been isolated and purified from both oncogenic and nononcogenic strains of Agrobacterium tumefaciens. Both RNAs are capable of inducing the formation of transplantable tumors when introduced at wound sites in stems of Datura stramonium plants. One of these RNA fractions was found to be bound to an RNA-directed DNA polymerase, while the other was associated with the bacterial DNA. Physical evidence suggests that both are single stranded and small in size; linear sucrose gradients show that their size corresponds to a value of 5-6 S. A concentration of 4-5 mug of the RNAs dissolved in 0.01 ml of water is effective in initiating the formation of transplantable tumors in Datura plants.  (+info)

Bronchodilator effects of antiasthmatic cigarette smoke (Datura stramonium). (29/46)

In 12 asthmatic patients with mild airway obstruction we have measured the effect on specific airway resistance (sRaw) of inhaling the smoke of one Datura stramonium cigarette. In 11 patients sRaw decreased substantially after the cigarette, the mean maximal decrease being 40% at the 30th minute. In seven patients the subsequent inhalation of 200 micrograms salbutamol caused no further decrease in sRaw. In the remaining four patients salbutamol induced a larger decrease in sRaw than the cigarette smoke. The inhalation, however, of a synthetic anticholinergic agent (SCH 1000, 600 micrograms) proved as effective as salbutamol in these patients. In one patient the cigarette smoke and SCH 1000 produced only a negligible amount of bronchodilatation whereas the bronchial obstruction was reversible with salbutamol. Minor side effects were observed in six patients after the cigarette.  (+info)

Teratogens in plants. (30/46)

Many compounds synthesized by plants are known to be teratogenic in laboratory animals, but only a few have been shown by feeding trials to produce terata in livestock. Studies of plant teratogens affecting livestock have not moved forward in a systematic nor rapid way because of the logistical problems connected with such experiments in large animals. Information that has accumulated can be conveniently separated into three categories: (1) known teratogens in known teratogenic plants, (2) known teratogenic plants with unidentified teratogens, and (3) suspected teratogenic plants. Included in the first group are the teratogens from Lupinus, Veratrum, Conium and Leucaena genera; in the second group are included the Astragalus , Nicotiana and Trachymene genera; and in the third group are included Datura, Prunus , Sorghum and Senecio genera. Total available information in each case varies, but in a few instances considerable fundamental as well as practical information is now known. Research has provided enough information in a few instances to enable elimination of the practical problem or significant reduction in incidence.  (+info)

Structural studies of the carbohydrate moieties of lectins from potato (Solanum tuberosum) tubers and thorn-apple (Datura stramonium) seeds. (31/46)

1. Methylation analysis of potato (Solanum tuberosum) lectin and thorn-apple (Datura stramonium) lectin confirmed previous conclusions that both glycoproteins contained high proportions of l-arabinofuranosides and lesser amounts of d-galactopyranosides. The arabinofuranosides are present in both lectins as short unbranched chains containing 1-->2- and 1-->3-linkages, which are known to be linked to hydroxyproline. Galactopyranosides are present as monosaccharides, which are known to be attached to serine, in potato lectin and as both the monosaccharide and the 1-->3-linked disaccharide in Datura lectin. 2. Alkaline digestion of potato lectin and subsequent separation of the components by gel filtration led to the isolation of four fractions corresponding to the mono-, di-, tri- and tetra-arabinosides of hydroxyproline. The latter two fractions accounted for over 70% of the total hydroxyproline. 3. Methylation analysis was used to show that the triarabinoside contained only 1-->2-linkages between sugars, but that the tetra-arabinoside contained both 1-->2- and 1-->3-linkages. Direct-insertion mass spectrometry of these compounds using electron impact and chemical ionization, in a comparison with other known structural patterns, was used to determine the sequences of the sugars, which were Araf1-->2Araf1-->2Araf1-->Hyp and Araf1-->3Araf1-->2Araf1-->2Araf 1-->Hyp. 4. On the basis of optical rotation it had previously been suggested [Allen, Desai, Neuberger & Creeth (1978) Biochem. J.171, 665-674] that all the arabinose of potato lectin was present as the beta-l-furanoside. However, measurement of the optical rotations of the hydroxyprolyl arabinosides showed that whereas the diarabinoside had a molar rotation ([m]) value close to that predicted, the triarabinoside was more dextrorotatory and the tetra-arabinoside was less dextrorotatory than expected. Possible explanations for these findings are that, although the di- and tri-arabinosides contain exclusively beta-arabinofuranosides, in the tri-arabinoside, interactions between pentose units lead to an enhanced positive rotation. The tetra-arabinoside, however, is proposed to contain a single alpha-arabinofuranoside residue, which is responsible for the lower than expected positive rotation. The observed rotation of the tetra-arabinoside was found to be close to the theoretical value predicted on that basis. Furthermore, the action of a specific alpha-arabinofuranosidase on the tetrasaccharide was to remove a single arabinose residue, presumably the terminal non-reducing sugar, and to produce a product that was indistinguishable on electrophoresis from the triarabinoside. Changes in rotation were compatible with this assumption. 5. It is concluded that the structures of the hydroxyprolyl tri- and tetra-arabinosides of potato lectin are: betaAraf1-->2betaAraf1-->2betaAraf1-->Hyp and alphaAraf1-->3betaAraf1-->2betaAraf 1-->2betaAraf1-->Hyp. These are identical with compounds that have been isolated from the insoluble hydroxyproline-rich glycoproteins of plant cell walls.  (+info)

Some properties of the lectin from Datura stramonium (thorn-apple) and the nature of its glycoprotein linkages. (32/46)

The lectin from Datura stramonium (thorn-apple; Solanaceae) has been purified by affinity chromatography and shown to be a glycoprotein containing about 40% (w/w) of carbohydrate. The most abundant amino acids are hydroxyproline, cystine, glycine and serine. Results obtained by gel filtration in 6m-guanidinium chloride on Sepharose 4B suggest that it has a subunit mol.wt. of about 30000 and that it probably associates into dimers. The lectin is inhibited specifically by chitin oligosaccharides and bacterial-cell-wall oligosaccharides, but only weakly by N-acetylglucosamine. Glycopeptides from soya-bean (Glycine max) lectin and fetuin are also strong inhibitors of Datura lectin, indicating that it interacts with internal N-acetylglucosamine residues. Its specificity is similar to, but not identical with, that of potato (Solanum tuberosum) lectin. After prolonged proteolytic digestion of reduced and S-carboxymethylated or S-aminoethylated derivatives of the lectin, glycopeptides of mol.wt. of about 18000 were isolated. The glycopeptides contained all the carbohydrate and hydroxyproline of the original glycoprotein, and lesser amounts of serine, S-carboxymethylcysteine and other amino acids. The arabinose residues of the glycoprotein are present as beta-l-arabinofuranosides linked to the polypeptide chain through the hydroxyproline residues, and can be removed by mild acid treatment; the ratio of arabinose to hydroxyproline is 3.4:1. Some of the serine residues of the polypeptide chain are substituted with one or two alpha-galactopyranoside residues, most of which can be removed by the action of alpha-galactosidase. The galactose residues are more easily removed from the acid-treated glycopeptide (from which arabinose has been removed) than from the complete glycopeptide, indicating a steric hindrance of the galactosidase action by the adjacent chains of arabinosides. There is a slow release of galactose residues by a process of beta-elimination in 0.5m-NaOH (pH13.7) from the complete glycopeptide, and a fairly rapid release of galactose by this process from the acid-treated glycopeptide, which lacks arabinose. This is probably due to the inhibitory effect of the negative charge on the adjacent arabinofuranoside residues. The similarities and differences between the lectins from Datura and potato are discussed, as are their structural resemblance to glycopeptides that have been isolated from plant cell walls.  (+info)