A review of curcumin as a biological stain and as a self-visualizing pharmaceutical agent

Curcumin has been widely used to color textiles but, unlike other natural dyes such as hematoxylin or saffron, it rarely has been discussed as a biological stain. Aspects of the physicochemistry of curcumin relevant to biological staining and self-visualization, i.e., its acidic properties, lipophilicity, metal and pseudometal complexes, and optical properties, are summarized briefly here. Reports of staining of non-living biological specimens in sections and smears, both fixed and unfixed, including specimens embedded in resin, are summarized here. Staining of amyloid, boron and chromatin are outlined and possible reaction mechanisms discussed. Use of curcumin as a vital stain also is described, both in cultured monolayers and in whole organisms. Staining mechanisms are considered especially for the selective uptake of curcumin into cancer cells. Staining with curcumin labeled nanoparticles is discussed. Toxicity and safety issues associated with the dye also are presented.     

Support for an expanded family concept of Malvaceae within a recircumscribed order Mai vales: a combined analysis of plastid atpB and rbcL DNA sequences

Sequence analyses of the plastid genes atpB and rbcL support an expanded order Malvales. Within this alliance, core Malvales are clearly supported and comprise most genera that have previously been included in Sterculiaceae, Tiliaceae, Bombacaceae, and Malvaceae. Additional well supported malvalean alliances include the bixalean clade (Bixaceae, Diego-dendraceae, and Cochlospermaceae), the cistalean clade (Cistaceae, Dipterocarpaceae, and Sarcolaenaceae) and Thymelaeaceae (including Gonystyloideae and Aquilarioideae). Our results indicate sister-group relationships between (1) Neuradaceae and the cistalean clade; (2) Sphaerosepalaceae and Thymelaeaceae; (3) these two clades (1 and 2); and (4) all these and an alliance comprising the bixalean clade and core Malvales, but this pattern is weakly supported by the bootstrap. The affinities of Muntingiaceae and Petenaea are especially ambiguous, although almost certainly they are Malvales s.l. The traditional delimitation of families within core Malvales is untenable. Instead, we propose to merge Sterculiaceae, Tiliaceae and Bombacaceae with Malvaceae and subdivide this enlarged family Malvaceae into nine subfamilies based on molecular, morphological, and biogeographical data: (1) Byttnerioideae, including tribes Byttnerieae, Lasiopetaleae and Theobromeae (all of which have cucullate petals) and Hermannieae; (2) Grewioideae, including most genera of former Tiliaceae; (3) Tilioideae, monogeneric in our analysis; (4) Helicteroideae, comprising most of the taxa previously included in Helictereae, plus Mansonia, Triplochiton (indicating that apocarpy evolved at least twice within Malvaceae) and possibly Durioneae; (5) Sterculioideae, defined by apetalous, apocarpous, usually unisexual flowers with androgynophores; (6) Brownlowioideae, circumscribed as in previous classifications; (7) Dombeyoideae, expanded to include Burretiodendron, Eriolaena, Pterospermum, and Schoutmia; (8) Bombacoideae, corresponding to former Bombacaceae (without Durioneae) but including Fremontodendreae     

Structure and Function of the Elasmobranch Auditory System

Behavioral evidence indicates that sharks detect underwatersound at frequencies up to 1000 Hz, and that certain low frequencysignals attract sharks from large distances. It appears thatthe adequate stimulus for "sound detecting" systems of the sharkis panicle motion, as opposed to fluctuations in sound pressure.The elasmobranch ear consists of the three semi-circular canalsfor detecting angular accelerations, and otolith organs fordetecting linear motion and accelerations due to gravity. Twoof these organs, the sacculus and macula neglecta, have beenshown to be responsive to vibratory motion, with the maculaneglecta having best sensitivity to vertical movements. A directvibrational pathway exists to the macula neglecta from the parietalfossa of the dorsal chondrocranium. It is not clear at present,however, whether it is the inner ear or the lateral line systemwhich is responsible for hearing. Both detection systems aretheoretically capable of providing information to the brainabout sound source location using non-parallel arrays of directionallysensitive hair-cell receptors. Recent theories of underwatersound localization by fishes and sharks suggest that the abilityto detect a vertical displacement component of an acoustic signal(e. g., via the macula neglecta) is necessary for instantaneouslocation decisions. It is not known, however, whether the sharkslocalize by processing information about various aspects ofthe sound field simultaneously (in parallel), or whether thesound field is sampled successively at different points in space.Clearly, more experimental work on the physiology of elasmobranchacoustic behavior is called for.     

Short repetitive sequences in green algal mitochondrial genomes: potential roles in mitochondrial genome evolution

Current data on green algal mitochondrial genomes suggest an unexpected dichotomy within the group with respect to genome structure, organization, and sequence affiliations. The present study suggests that there is a correlation between this dichotomy on one hand and the differences in the abundance, base composition, and distribution of short repetitive sequences we observed among green algal mitochondrial genomes on the other. It is conceivable that the accumulation of GC- rich short repeated sequences in the Chlamydomonas-like but not Prototheca-like mitochondrial genomes might have triggered evolutionary events responsible for the distinct series of evolutionary changes undergone by the two green algal mitochondrial lineages. The similarity in base composition, nucleotide sequence, abundance, and mode of organization we observed between the short repetitive sequences present in Chlamydomonas-like mitochondrial genomes on one hand and fungal and vertebrate homologs on the other might extend to some of the roles that the short repetitive sequences have been shown to have in the latter. Potential involvements we propose for the short repetitive sequences in the evolution of Chlamydomonas-like mitochondrial genomes include fragmentation and scrambling of the ribosomal-RNA-coding regions, extensive gene rearrangements, coding-region deletions, surrogate origins of replication, and chromosomal linearization.      

Changes in grassland ecosystem function due to extreme rainfall events: implications for responses to climate change

Climate change is causing measurable changes in rainfall patterns, and will likely cause increases in extreme rainfall events, with uncertain implications for key processes in ecosystem function and carbon cycling. We examined how variation in rainfall total quantity (Q), the interval between rainfall events (I), and individual event size (S_E) affected soil water content (SWC) and three aspects of ecosystem function: leaf photosynthetic carbon gain (), aboveground net primary productivity (ANPP), and soil respiration (). We utilized rainout shelter‐covered mesocosms (2.6 m³) containing assemblages of tallgrass prairie grasses and forbs. These were hand watered with 16 I×Q treatment combinations, using event sizes from 4 to 53 mm. Increasing Q by 250% (400–1000 mm yr^?1) increased mean soil moisture and all three processes as expected, but only by 20–55% (P≤0.004), suggesting diminishing returns in ecosystem function as Q increased. Increasing I (from 3 to 15 days between rainfall inputs) caused both positive () and negative () changes in ecosystem processes (20–70%, P≤0.01), within and across levels of Q, indicating that I strongly influenced the effects of Q, and shifted the system towards increased net carbon uptake. Variation in S_E at shorter I produced greater response in soil moisture and ecosystem processes than did variation in S_E at longer I, suggesting greater stability in ecosystem function at longer I and a priming effect at shorter I. Significant differences in ANPP and between treatments differing in I and Q but sharing the same S_E showed that the prevailing pattern of rainfall influenced the responses to a given event size. Grassland ecosystem responses to extreme rainfall patterns expected with climate change are, therefore, likely to be variable, depending on how I, Q, and S_E combine, but will likely result in changes in ecosystem carbon cycling.     

Systematics of the tribe Podalyrieae (Fabaceae) based on DNA, morphological and chemical data

Phylogenetic relationships among nine genera and 28 species of the southern African tribe Podalyrieae were estimated from sequences of the internal transcribed spacer (ITS) of nuclear ribosomal DNA as well as morphological and chemical data. Morphological and ITS sequence data produced cladograms with similar topologies, both supporting the monophyly of Podalyrieae (excluding Hypocalyptus ). The combined data sets indicate that subtribe Xiphothecinae are monophyletic, but embedded within Podalyriinae. The high degree of congruence between previous taxonomic hypotheses and those based on DNA data provides further evidence for the utility of ITS sequences in studying phylogeny.  © 2002 The Linnean Society of London , Botanical Journal of the Linnean Society , 2002, 139 , 159–170.     

Systematics of Vitaceae from the viewpoint of plastid rbcL DNA sequence data

A phylogenetic analysis of plastid rbcL DNA sequences for 20 species of Vitaceae s.l. (including Leeaceae) and eight outgroups from Dilleniaceae and Santalales is presented. Patterns of floral and vegetative morphology and ontogeny within the family are compared to the phylogenetic trees produced. Despite the limited sampling of large and variable genera, there is a good correspondence with hypothesized floral and vegetative ontogenetic trends, with Leea and Ampelopsis ancestral, Cissus and Ampelocissus intermediate and Vitis most derived. A clade containing Parthenocissus , Tetrastigma , Cyphostemma and Vitis is found in all shortest trees. Cyphostemma and Parthenocissus are shown to be closely related to Vitis , to which clade Tetrastigma and Cayratia comprise the sister clade. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 421–432.