Nor-ent-kaurane diterpenes and hydroxylactones from Antennaria geyeri and Anaphalis margaritacea

In a study of Pacific Northwest plants of the Asteraceae family, a nor-ent-kaurane diterpene and a known diterpene, both displaying antibacterial activities, were isolated together with scopoletin and sitosterol-3-O-beta-glucopyranoside from the aerial parts of Antennaria geyeri. Anaphalis margaritacea afforded two hydroxylactones. The structures were established by one and two dimensional NMR techniques, IR and CIMS.     

C6-Green leaf volatiles trigger local and systemic VOC emissions in tomato

In response to insect feeding, tomato plants (Lycopersicon esculentum) release elevated levels of volatile organic compounds; that is, monoterpenes and sesquiterpenes are released both locally and systemically with wounding while C(6) green leaf volatiles are released only from damaged leaves. With the exogenous application (100 nmol) of the C(6)-tomato-volatile (E)-2-hexenal, an increase in the release of local and systemic terpenes was observed, while an equimolar amount of methyl jasmonate triggered only local emissions of terpenes. Labeling studies with 13CO(2) showed that de novo synthesis was not required for monoterpene or sesquiterpene release immediately following chemical treatment or insect feeding. Comparative measurements were made between aldehyde doses applied to the plant and levels naturally released from leaves with insect damage.     

Potential protective effect of HSCAS and bentonite against dietary aflatoxicosis in rat: with special reference to chromosomal aberrations.

Bentonite and hydrated sodium calcium aluminsilicate (HSCAS) were added at a level of 0.5% (w/w) to the diets containing 2.5 mg aflatoxins (AF) per kg diet and fed to male mature rats for 15 successive days. Aflatoxin alone significantly decreased feed intake and altered serum biochemical parameters of liver and kidney functions. Aflatoxin caused chromosomal aberrations in bone marrow cells. Bentonite or HSCAS did not alter any of the parameters measured. The addition of bentonite or HSCAS to the AF-contaminated diet diminished most of the deleterious effects of the aflatoxin. Pathological examinations of liver and kidney proved that both bentonite and HSCAS were hepatonephroprotective agents against aflatoxicosis. The cytogenetic findings demonstrated that the addition of bentonite or HSCAS to AF-contaminated diet suppressed chromosomal aberrations. These findings indicated that bentonite and HSCAS could diminished many of the adverse effect of dietary AF in rats.     

Statistical procedure for evaluating the sensitivity of Limulus amoebocyte lysate by using a reference lysate.

A study was designed to estimate variability of the Limulus amoebocyte lysate test by comparing a reference lysate against itself. Three technicians performed parallel tests, i.e., titrated side by side, the contents of two vials of reference lysate on 4 different days using 24 vials of the United States reference lysate and 12 vials of the United States reference endotoxin. Each parallel test was replicated three times. From the sensitivity endpoints, ratios were calculated for each parallel test. These ratios were converted to the logarithm for estimating variability among technicians and among vials of endotoxin. By using the overall variability of log ratios, a statistical procedure was developed to evaluate the sensitivity of each lot of licensed lysate submitted to the Bureau of Biologics for release.     

Autosomal recessive “uncomplicated” profound childhood deafness in an arabic family with high consanguinity

Summary An Arabic family has been studied in our genetic counselling centre. This family included 13 cases of heritable uncomplicated profound childhood deafness. All of these were the offspring of first cousin (F.C.) marriages. The inheritance pattern was consistent with autosomal recessive (A.R.) determination of the deafness and all the affected children studied showed identical phenotypic expression.     

Metabolic profiling of Medicago truncatula cell cultures reveals the effects of biotic and abiotic elicitors on metabolism

GC-MS-based metabolite profiling was used to analyse the response of Medicago truncatula cell cultures to elicitation with methyl jasmonate (MeJa), yeast elicitor (YE), or ultraviolet light (UV). Marked changes in the levels of primary metabolites, including several amino acids, organic acids, and carbohydrates, were observed following elicitation with MeJa. A similar, but attenuated response was observed following YE elicitation, whereas little response was observed following UV elicitation. MeJa induced the accumulation of the triterpene beta-amyrin, a precursor to the triterpene saponins, and LC-MS analysis confirmed the accumulation of triterpene saponins in MeJa-elicited samples. In addition, YE induced a slight, but significant accumulation of shikimic acid, an early precursor to the phenylpropanoid pathway, which was also demonstrated to be YE-inducible by LC-MS analyses. Correlation analyses of metabolite relationships revealed perturbation of the glycine, serine, and threonine biosynthetic pathway, and suggested the induction of threonine aldolase activity, an enzyme as yet uncharacterized from plants. Members of the branched chain amino acid pathway accumulated in a concerted fashion, with the strongest correlation being that between leucine and isoleucine (r2=0.941). While UV exposure itself had little effect on primary metabolites, the experimental procedure, as revealed by control treatments, induced changes in several metabolites which were similar to those following MeJa elicitation. Sucrose levels were lower in MJ- and YE-elicited samples compared with control samples, suggesting that a portion of the effects observed on the primary metabolic pool are a consequence of fundamental metabolic repartitioning of carbon resources rather than elicitor-specific induction. In addition, beta-alanine levels were elevated in all elicited samples, which, when viewed in the context of other elicitation responses, suggests the altered metabolism of coenzyme A and its esters, which are essential in secondary metabolism.     

Regeneration of Immature Inflorescences of Barley In Vitro

Two spring barley cultivars, Golden Promise and Galan, were screened for callus induction and shoot regeneration from cultured immature inflorescences. Genotype Galan have better regeneration capacity in in vitro conditions than Golden Promise.     

Intercalating nucleic acids: the influence of linker length and intercalator type on their duplex stabilities

Six new examples of intercalating nucleic acids were synthesized in order to evaluate the dependence of the length of the linker between oligo and intercalator on the thermal stability of their corresponding duplexes and triplexes.