Cannabinoids for the pharmaceutical industry

Summary Cannabis sativa, is a rich source of a variety of compounds, including cannabinoids, terpenoids and flavonoids. Their content depends upon the plant genetics, growth conditions, time of harvest and drying conditions. To date, more than 60 different cannabinoids have been identified in the plant. Cannabis has been used medicinally for 4000 years and remained in the British pharmacopaeia until 1932, and in the British Pharmaceutical Codex until 1949. Medical use has been prohibited in the UK since 1973. The principal cannabinoid, delta-9-tetrahydrocannabinol (THC) was first isolated in 1964; the first cannabinoid pharmaceutical product Marinol® (a synthetic THC product) was approved in the USA in 1985. The discovery of specific cannabinoid receptors in the early 1990s and subsequent identification of the endocannabinoids anandamide and 2-arachadonoylglycerol, led to a resurgence of interest in the field of cannabinoid medicine, especially within the pharmaceutical industry. Cannabidiol (CBD), as a non-psychoactive, cannabinoid is currently a cannabinoid of significant interest, showing a wide range of pharmacological activity. The other classes of compounds present in cannabis also have their own pharmacology (e.g. terpenoids, flavonoids). The potential for interaction and synergy between compounds within the plant, may play a role in the therapeutic potential of cannabis. This may explain why a cannabis-based medicine using extracts containing multiple cannabinoids, in defined ratios, and other non-cannabinoid fractions, may provide better therapeutic success and be better tolerated than the single synthetic cannabinoid medicines currently available. The development and employment of one of these medicines, Sativex®, is described.     

Development of a SNLP marker from the Pi-ta blast resistance gene by tri-primer PCR

The Pi-ta gene from indica introgressed into japonica rice has been used to control the blast disease caused by the fungal pathogen Magnaporthe grisea (Herbert) Barr. (anamorph Pyricularia oryzae Cav.) worldwide. A single nucleotide length polymorphism (SNLP) was identified at the intron region of the Pi-ta gene to develop a codominant Pi-ta gene marker suitable for genotyping with an automated machine. The DNA primer specific to the resistant Pi-taallele was labeled with blue dye (FAM, 6-carboxyfluorescein) as a forward primer, the DNA primer specific to the susceptible pi-ta allele was labeled with green dye (HEX, 4,7,2′,4′,5′,7′-hexachloro-6-carboxyfluorescein) as another forward primer and the DNA primer identical to both Pi-ta/pi-ta alleles was unlabeled as the reverse primer for polymerase chain reaction (PCR). Using these three primers, a 181-bp blue peak in homozygous resistant and a green peak of 182–183 bp in homozygous susceptible, and both peaks in heterozygous plants were produced by PCR. The utility of marker was verified using a segregating F₂ population, inbred cultivated lines, dominant markers and pathogenicity testing. A codominant Pi-ta marker was thus developed for effective Pi-ta assisted selection for crop improvement. Using highly homologous competitive primers for allele detection by PCR can benefit the study of genome organization of the complex locus. This revised version was published online in August 2006 with corrections to the Cover Date.     

Determinants of the Travel Behavior of the Suburban Elderly

In recent years, a significant feature of population change in North American metropolitan areas has been the rapid suburbanization of elderly people. The ability to engage in routine activity may be a necessary condition for the maintenance of independent life styles and psychological well‐being among older suburbanites. Using a conceptual framework based on Parmelee and Lawton's ecological model of aging, this article offers an exploratory investigation of the determinants of the travel of separate samples of elderly male and female suburbanites to each of five destination categories of key service/activity sites in a Canadian city. The results of the tests of ten multiple regression models disclose that the levels of explanation of trip frequency afforded by “autonomy components” (e.g. health‐related characteristics, living arrangements, and income level) vary according to destination category. However, the explanatory power of “security components” (i.e. variables concerning access to destination categories) is generally low. Overall, the findings of the study provide a basis for developing a deeper understanding of the repetitive travel behavior of elderly suburbanites.     

Congruity backcrossing as a means of creating genetic variability in self pollinated crops: seed morphology of Phaseolus vulgaris L. and P. acutifolius A. Gray hybrids

Summary Seeds of early generations of three reciprocal congruity-backcross (CBC) pedigrees, developed by backcrossing Phaseolus vulgaris-P. acutifolius hybrids to each of the parent species in alternate generations, exhibited a preponderance of traits (size, shape, color, and pattern) of the cytoplasmic parent. The large size of Red Cloud (V₁), the P. vulgaris parent common to all of the pedigrees, dominated pedigrees with V₁ as the cytoplasmic parent, while the small size and rounded or square shapes of the tepary parents, wild P. acutifolius var. acutifolius PI 263590 or G400445 (A₁₉), wild P. acutifolius var. latifolius PI 406622 (A₁₀), or cultivated P. acutifolius var. latifolius Serowi PI 319443 (A₉), were the majority phenotypes when P. acutifolius was the cytoplasmic parent. Continuing through the second cycle of CBC, that is the second backcross with each of the parent species or the fourth backcross, began an amelioration of the apparent cytoplasmic effect on gene expression, as reciprocal pedigrees became more alike, usually with intermediate expression of parental traits or the appearance of new traits. The large seed size of V₁ was recovered in hybrids with P. acutifolius cytoplasm and the kidney shape of V₁ became rare in hybrids with P. vulgaris cytoplasm. Although the tepary-bean parents represented two subspecies and both cultivated and wild P. acutifolius, the three sets of reciprocal-hybrid pedigrees with P. vulgaris Red Cloud are surprisingly similar. It may be that the exotic parent used to develop a CBC pedigree should be selected more for combining ability in the interspecific cross than for specific economic traits. While the number of generations (six or more) required to produce fertile, intermediate CBC hybrids (that did not require embryo rescue) may preclude routine use of this method by practical plant breeders, the crossability of advanced hybrids with both parental species and the amount of variability apparent in advanced-hybrids progenies suggests that CBC would be valuable for maintaining exotic germplasm in immediately useful forms.     

Regrowth forests on abandoned agricultural land: A review of their habitat values for recovering forest fauna

Human land use has modified the structure and function of terrestrial landscapes throughout much of the world, with cropping and livestock grazing the major drivers of landscape change. In many tropical, sub-tropical, temperate and Mediterranean regions, regrowth forests regenerate naturally on abandoned agricultural land if human disturbance declines. With the exception of some tropical forest literature, the broader ecological and conservation literature has largely ignored the potential of regrowth forests to facilitate passive landscape restoration and the recovery of fauna communities in fragmented agricultural landscapes. This paper addresses this deficiency by reviewing the available global evidence of fauna recovery in regrowth forest from 68 papers, identifying the main gaps in current knowledge, and providing directions for further research. The majority of reviewed studies focus on regrowth in tropical regions, which often contain large areas of mature forest. Species’ utilisation of regrowth forest is highly variable and is particularly influenced by land-use history, an important determinant of the structural and compositional characteristics of regrowth forests. While site-scale (<1 ha) forest structure and floristic diversity were frequently studied, only 11 studies considered the spatial configuration and context of habitat patches and just two studies explicitly considered landscape structure. Based on this review, six key research questions are posed to direct future research on this important issue. We conclude that a broader perspective of the role of regrowth forest in the landscape is required if we are to realise the potential benefits of regrowth forest for passive landscape restoration and fauna conservation and recovery.