Studies on Datura Leichhardtii Muell. Ex Benth

The variation in the proportion of hyoscyamine and hyoscine in the aerial parts of Datura leichhardtii has been investigated. From the roots, the alkaloids 7-hydroxy-3, 6-ditigloyloxytropane, 3α-tigloyloxytropane and meteloidine have been isolated.

Studies on Datura Leichhardtii Muell. Ex Benth

Datura leichhardtii is readily distinguished from other species of the genus by its general morphology. Although similar to that of D. stramonium, the microscopy of the leaf differs in the length of the clothing trichomes and often in the form of the calcium oxalate crystals; it may be distinguished from other members of the Section Dutra, with the exception of D. metel, by the form and abundance of trichomes. D. leichhardtii differs from D. metel in possessing on the lamina of the leaf, glandular trichomes with a uniseriate stalk and a single-celled head. The values for palisade ratio and stomatal index are within the same range as those of allied species.

Part II.–The Alkaloids of Australian Datura Ferox and of Indian Henbane

Australian-grown Datura ferox has been found to contain as principal alkaloids, hyoscine and meteloidine. The chief alkaloidal constituents of Indian henbane are hyoscine, hyoscyamine and tropine; in this respect, Indian henbane differs from Hyoscyamus niger only in the absolute and relative proportions of the alkaloids.

What price for a year of life? A survey of U.S. and Canadian oncologists

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Background: New cancer drugs are increasingly expensive and raise difficult questions about the magnitude of therapeutic benefit needed to justify their incremental cost. In this context, it is unclear whether oncologists endorse standard thresholds of $50,000 to $100,000 per year of life. Methods: We surveyed 1,379 U.S. and 356 Canadian (Cdn) oncologists and asked how much longer a patient would need to survive metastatic cancer to justify the expense of a new treatment. To determine the stability of attitudes towards cost-effectiveness (CE) we randomized oncologists to receive two different versions of the scenario in which the price of the new treatment was varied (higher versus lower drug cost). In the U.S. survey, oncologists were also randomized to receive surveys in which we varied the provision of contextual information about the CE of several familiar interventions. Both U.S. and Cdn oncologists were asked to indicate what they “thought was ‘good value for money’ expressed as cost per life-year gained (LYG).” Results: Response rate was 57% in the U.S. and 48% in Canada. CE ratios implied by oncologists’ responses differed significantly between the groups randomized to the higher versus lower price of the hypothetical treatment (p < 0.001 U.S., p < 0.0001 Canada), but were independent of randomization to varying contextual information (p > 0.1). The median willingness to pay for a quality-adjusted year of life ranged from $150,000 (for oncologists considering the lower priced drug) to $250,000 (for those considering the more expensive drug) in both countries. Among those who considered the more expensive drug, 25% of respondents implicitly endorsed a CE ratio greater than $600,000 (U.S.) and $500,000 (Canada). In contrast, when asked directly to indicate CE ratios that were good value for the money outside of the clinical scenario, 70% (U.S.) and 64% (Canada) of respondents indicated values of less than $100,000 per LYG. Conclusions: Oncologists responding to our survey provided inconsistent views on how much benefit expensive new drugs should provide to be worthwhile. This suggests that means of eliciting input from physicians that reflect more stable attitudes need to be developed to appropriately inform decision-makers.

No significant financial relationships to disclose.

A survey of U.S. and Canadian oncologists’ attitudes toward the cost, cost-effectiveness (CE), and reimbursement of cancer drugs

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Background: Drug costs and reimbursement issues offer significant challenges to U.S. and Canadian oncologists even though they practice in substantially different health care systems. However, little is known about the attitudes of American and Canadian oncologists towards these issues. Methods: We surveyed 1,379 U.S. and 356 Cdn oncologists to assess their attitudes to cancer drug costs, CE and reimbursement policies. Results: Response rate was 57% in the U.S. and 48% in Canada. Oncologists in both countries stated that patients' “out-of-pocket” drug costs influenced their treatment recommendations (84% U.S., 80% Cdn respondents). Most respondents felt that every patient should have access to effective cancer treatments regardless of cost (66% US; 54% Cdn), while 59% of U.S. and 72% of Cdn and respondents believed that patients should only have access to effective cancer treatments that provided “good value for money.” 70% of U.S. and 64% Cdn respondents felt that <$100,000 per life year gained was a reasonable definition of “good value for money” but less than half of respondents (42% US, 49% Cdn) felt well prepared to interpret and use CE information in their treatment decisions. A majority of respondents (57% US, 69% Cdn) felt government price controls for cancer drugs are needed while a minority felt that more cost-sharing by patients was needed (29% US, 37% Cdn). Most oncologists felt that evaluating whether a drug provides “good value” should be overseen by an independent non-profit agency (57% US, 71% Cdn) or physicians (61% US and Cdn); in contrast, few believed that government (21% US, 33% Cdn), patients (36% US, 37% Cdn) or insurance companies (6% US, 10% Cdn) should determine “good value”. 79% of U.S. and 69% of Cdn respondents felt more use of CE data in coverage and reimbursement decisions is needed. Conclusions: Oncologists in the U.S. and Canada share many similar attitudes to cancer drug costs, CE, and reimbursement policies despite differences in their health care systems. In both countries, oncologists favor more use of CE information.

No significant financial relationships to disclose.

Annatto: a natural choice

Annatto is a pigment derived from the seeds of Bixa orellana. It has been used from antiquity in South America and for over 100 years in Europe. It is now an important safe additive for a wide range of food, partly finding favour due to its natural origin.

Alkaloids of hairy root cultures of a Datura candida hybrid

From the in vitro hairy root cultures of a Datura candida hybrid, 19 tropane alkaloids have been identified using capillary gas-liquid chromatography and mass spectrometry. As in the parent plants, scopolamine is the major alkaloid. Two hitherto undescribed alkaloids have been detected and their structure tentatively characterised on the basis of their mass spectral fragmentations.

High-yield production of tropane alkaloids by hairy-root cultures of aDatura candida hybrid

Hairy root cultures were obtained following inoculation of the stems of sterile plantlets of aDatura candida hybrid withAgrobacterium rhizogenes. The scopolamine and hyoscyamine content was quantified by HPLC and compared with the non-transformed plants. The alkaloid yield (0.68% dry weight) obtained with the hairy roots was 1.6 and 2.6 times the amount found in the aerial parts and in the roots of the parent plants, respectively. Only a small proportion of alkaloids was released into the growth medium. Scopclamine was the principal alkaloid and the scopolamine/hyoscyamine ratio of ca. 5:1 makes these hairy roct cultures worthy of consideration as a source of scopolamine.

The 1986 Lake Nyos Gas Disaster in Cameroon, West Africa

The sudden, catastrophic release of gas from Lake Nyos on 21 August 1986 caused the deaths of at least 1700 people in the northwest area of Cameroon, West Africa. Chemical, isotopic, geologic, and medical evidence support the hypotheses that (i) the bulk of gas released was carbon dioxide that had been stored in the lake's hypolimnion, (ii) the victims exposed to the gas cloud died of carbon dioxide asphyxiation, (iii) the carbon dioxide was derived from magmatic sources, and (iv) there was no significant, direct volcanic activity involved. The limnological nature of the gas release suggests that hazardous lakes may be identified and monitored and that the danger of future incidents can be reduced.

Tropane alkaloids of species of anthocercis, cyphanthera and crenidium

Eight tropane alkaloids, anabasine and ursolic acid have been isolated from the newly-described species CRENIDIUM SPINESCENS. ANTHOCERCIS ILICIFOLIA possesses a similar alkaloid spectrum to that of A. LITTOREA to which it is taxonomically closely related. In alkaloid composition, A. GENISTOIDES is a variable species and the sample analysed here contained meteloidine as principal alkaloid. The alkaloids of CYPHANTHERA ODGERSII and C. TASMANICA are consistent with those of other species of the genus. At present, ursolic acid does not appear to be a useful characteristic for the classification of solanaceous taxa belonging to Anthocercideae.

Chemical and toxicological studies on bracken fern, Pteridium aquilinum var. latiusculum. VIII. The inability of bracken extracts containing pterosins to cause cattle bracken poisoning

Methanol extracts of bracken frond and rhizomes prepared using a metallic extraction vessel, were proved incapable of producing bracken poisoning in calves. Nevertheless, they contained appreciable quantities of pterosins and pterosides. Thus the poisonous principle(s) in bracken responsible for the toxicological effects are not associated with these major sesquiterpenoids of the plant.

The comparative phytochemistry of the genus Erythroxylon

Recent research suggests that, in addition to the well-documented occurrence of significant quantities of cocaine and related alkaloids in a limited number of species, the genus Erythroxylon will prove to be a rich source of tropane alkaloids. These bases are esters of a range of acids with tropine, 3 alpha, 6 beta-dihydroxytropane and 3 alpha, 6 beta, 7 beta-trihydroxytropane; the numbers are further increased by nor-derivatives, and stereoisomerism involving the C-3 hydroxyl of the tropane skeleton. The diterpenes of the genus also appear worthy of further study.

A steroid constituent from Solanum abutiloides

A steroidal aglycone, isonuatigenin, has been isolated from the hydrolysate of unripe fruits of Solanum abutiloides. The acetylation of isonuatigenin in weak acid has been studied.

Biochemistry of the bacterial catabolism of aromatic compounds in anaerobic environments

Methods of aerobic degradation of aromatic compounds in the biosphere are well understood, but it is only relatively recently that it has been shown how some bacteria can also degrade these substrates in the absence of molecular oxygen. This occurs by photometabolism (Athiorhodaceae), nitrate respiration (Pseudomonas and Moraxella sp.) and methanogenic fermentation (a consortium) in which the benzene nucleus is first reduced and then cleaved by hydrolysis to yield aliphatic acids for cell growth. These methods may be used by microbial communities to catabolise man-made pollutants.