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One in five of the world's plant species is threatened with extinction according to the 2010 first global analysis of extinction risk. Tilman et al. predicted a massive ecological change to terrestrial plants within the next 50-100 y, accompanied by an increase in the number of global plant species facing extinction [Tilman D, et al. (2001) Proc Natl Acad Sci USA 98(10):5433-5440]. Most of the drug-producing plant families contain endangered species never previously studied for their utility to human health, which strongly validates the need to prioritize protection and assessment of these fragile and endangered groups [Zhu F, et al. (2011) Proc Natl Acad Sci USA 108(31):12943-12948]. With little prior attention given to endangered and rare plant species, this report provides strong justification for conservation of the rare plant Diplostephium rhododendroides Hieron., as well as other potential drug-producing endangered species in this and other groups.

Background: Nature has been a source of medicinal products for millennia, with many useful drugs developed from plant sources. Following discovery of the penicillins, drug discovery from microbial sources occurred and diving techniques in the 1970s opened the seas. Combinatorial chemistry (late 1980s), shifted the focus of drug discovery efforts from Nature to the laboratory bench., Scope of Review: This review traces natural products drug discovery, outlining important drugs from natural sources that revolutionized treatment of serious diseases. It is clear Nature will continue to be a major source of new structural leads, and effective drug development depends on multidisciplinary collaborations., Major Conclusions: The explosion of genetic information led not only to novel screens, but the genetic techniques permitted the implementation of combinatorial biosynthetic technology and genome mining. The knowledge gained has allowed unknown molecules to be identified. These novel bioactive structures can be optimized by using combinatorial chemistry generating new drug candidates for many diseases., General Significance: The advent of genetic techniques that permitted the isolation / expression of biosynthetic cassettes from microbes may well be the new frontier for natural products lead discovery. It is now apparent that biodiversity may be much greater in those organisms. The numbers of potential species involved in the microbial world are many orders of magnitude greater than those of plants and multi-celled animals. Coupling these numbers to the number of currently unexpressed biosynthetic clusters now identified (>10 per species) the potential of microbial diversity remains essentially untapped., (Published by Elsevier B.V.)

The discovery and development of novel, biologically active agents from natural sources, whether they be drugs, agrochemicals or other bioactive entities, involve a high level of interdisciplinary as well as international collaboration. Such collaboration, particularly at the international level, requires the careful negotiation of collaborative agreements protecting the rights of all parties, with special attention being paid to the rights of host (source) country governments, communities and scientific organizations. While many biodiversity-rich source countries currently might not have the necessary resources for in-country drug discovery and advanced development, they provide valuable opportunities for collaboration in this endeavor with research organizations from more high-income nations. This chapter discusses the experiences of the US National Cancer Institute and the US government-sponsored International Cooperative Biodiversity Groups program in the establishment of international agreements in the context of the Convention of Biological Diversity's objectives of promoting fair and equitable collaboration with multiple parties in many countries, and includes some specific lessons of value in developing such collaborations.

Understanding the skin's material properties and natural motion is critical to a myriad of applications from tissue engineering to spacesuits. While there is an extensive understanding of human skin properties based on active tensile testing, both in vitro and in vivo, there is a little current knowledge of the strains experienced by skin during natural movements. Using a motion capture system, we have developed a new technique to measure skin movement and strain around the knee during a squatting motion. With these new data, we are also able to calculate the local direction of lines of nonextension, or contours of the skin that remain a constant length during motion, lines of minimum extension, and lines of minimum compression.

Screening natural product extracts from the National Cancer Institute Open Repository for antifungal discovery afforded hits for bioassay-guided fractionation. Using LC-MS analysis to generate chemical structure information on potentially active compounds, two new cyclic hexapeptides, microsclerodermins J ( 1 ) and K ( 2 ), were isolated from the deep-water sponge Microscleroderma herdmani , along with microsclerodermins A ( 3 ) and B ( 4 ), previously isolated from an unidentified Microscleroderma species. The structures of the new compounds were elucidated by spectroscopic analysis and chemical methods. In vitro antifungal testing showed that the four compounds possessed strong activities against the opportunistic fungal pathogens Candida albicans , C andida glabrata, Candida krusei, Cryptococcus neoformans , and Aspergillus fumigatus .

This review is an updated and expanded version of the three prior reviews that were published in this journal in 1997, 2003, and 2007. In the case of all approved therapeutic agents, the time frame has been extended to cover the 30 years from January 1, 1981, to December 31, 2010, for all diseases worldwide, and from 1950 (earliest so far identified) to December 2010 for all approved antitumor drugs worldwide. We have continued to utilize our secondary subdivision of a "natural product mimic" or "NM" to join the original primary divisions and have added a new designation, "natural product botanical" or "NB", to cover those botanical "defined mixtures" that have now been recognized as drug entities by the FDA and similar organizations. From the data presented, the utility of natural products as sources of novel structures, but not necessarily the final drug entity, is still alive and well. Thus, in the area of cancer, over the time frame from around the 1940s to date, of the 175 small molecules, 131, or 74.8%, are other than "S" (synthetic), with 85, or 48.6%, actually being either natural products or directly derived therefrom. In other areas, the influence of natural product structures is quite marked, with, as expected from prior information, the anti-infective area being dependent on natural products and their structures. Although combinatorial chemistry techniques have succeeded as methods of optimizing structures and have been used very successfully in the optimization of many recently approved agents, we are able to identify only one de novo combinatorial compound approved as a drug in this 30-year time frame. We wish to draw the attention of readers to the rapidly evolving recognition that a significant number of natural product drugs/leads are actually produced by microbes and/or microbial interactions with the "host from whence it was isolated", and therefore we consider that this area of natural product research should be expanded significantly.

Using a mid- to late-gestation ovine model of intrauterine growth restriction (IUGR), we examined uteroplacental blood flow and fetal growth during melatonin supplementation as a 2 × 2 factorial design. At day 50 of gestation, 32 ewes were supplemented with 5 mg of melatonin (MEL) or no melatonin (CON) and were allocated to receive 100% [adequate; (ADQ)] or 60% [restricted (RES)] of nutrient requirements until day 130 of gestation. Umbilical artery blood flow was increased from day 60 to day 110 of gestation in MEL vs. CON dams, while umbilical artery blood flow was decreased from day 80 to day 110 of gestation in RES vs. ADQ dams. At day 130 of gestation, uteroplacental hemodynamics, measured under general anesthesia, and fetal growth were evaluated. Uterine artery blood flow was decreased in RES vs. ADQ dams, while melatonin supplementation did not affect uterine artery blood flow. Total placentome weight and placentome number were not different between treatment groups. Fetal weight was decreased by nutrient restriction. Abdominal girth and ponderal index were increased in fetuses from MEL-ADQ dams vs. all other groups. Fetal biparietal distance was decreased in CON-RES vs. CON-ADQ dams, while melatonin supplementation rescued fetal biparietal distance. Fetal kidney length and width were increased by maternal melatonin treatment. Fetal cardiomyocyte area was altered by both maternal melatonin treatment and nutritional plane. In summary, melatonin may negate the consequences of IUGR during specific abnormalities in umbilical blood flow as long as sufficient uterine blood perfusion is maintained during pregnancy.

Pea chips are produced as a by-product when field peas are processed to produce split peas for human consumption. The objective of this experiment was to test the hypothesis that inclusion of pea chips in diets fed to finishing pigs does not negatively influence pig growth performance, carcass composition, and the palatability of pork. A total of 24 barrows (initial BW: 58.0 ± 6.6 kg) were allotted to 1 of 4 treatments and fed early finishing diets for 35 d and late finishing diets for 35 d. A corn-soybean meal (SBM) control diet and 3 diets containing pea chips were formulated for each phase. Pea chips replaced 33.3, 66.6, or 100% of the SBM in the control diet. Pigs were housed individually, and all pigs were slaughtered at the conclusion of the experiment. Overall, there were no differences (P > 0.11) in final BW, ADFI, and G:F of pigs among treatments, but there was a quadratic response in ADG (P = 0.04), with the smallest value observed in pigs fed the control diet. Dressing percentage linearly decreased (P = 0.04) as pea chips replaced SBM in diets, but there were no differences (P > 0.20) among treatments in HCW, LM area, 10th-rib backfat, lean meat percentage, and marbling. Likewise, pH in loin and ham, drip loss, and purge loss were not influenced (P > 0.13) by treatment. However, there was a quadratic response (P = 0.08) in 24-h pH in the shoulder, with the smallest value present in pigs fed the diet, in which 66.6% of the SBM was replaced by pea chips. Subjective LM color and Japanese color score standard were reduced (quadratic, P = 0.03 and 0.05, respectively) and LM b* values and hue angle were increased (quadratic, P = 0.09 and 0.10, respectively) when pea chips replaced SBM in the diets. Ham L* (quadratic, P = 0.04), a* (linear, P = 0.02), b* (quadratic, P = 0.07), color saturation (linear, P = 0.02), and hue angle (quadratic, P = 0.05) were increased when pea chips replaced SBM. However, there were no differences (P > 0.16) in shoulder and fat color. Moreover, cook loss percentage, shear force, juiciness, and pork flavor of pork chops were not different (P > 0.10) among treatments, but tenderness of pork chops linearly decreased (P = 0.04) as SBM replaced pea chips. It is concluded that all the SBM in diets fed to growing-finishing pigs may be replaced by pea chips without negatively influencing growth performance or carcass composition. However, pigs fed pea chips will have pork chops and hams that are lighter, and chops may be less tender if pigs are fed pea chips rather than corn and SBM.

A sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the quantification of the plant natural product silvestrol in mice, using ansamitocin P-3 as the internal standard. The method was validated in plasma with a lower limit of quantification of 1 ng/mL, accuracy ranging from 87 to 114%, and precision (coefficient of variation) below 15%. The validated method was used to characterize pharmacokinetics in C57BL/6 mice and metabolism in mouse, human and rat plasma, and liver microsomes. Mice were dosed with silvestrol formulated in hydroxypropyl-β-cyclodextrin via intravenous, intraperitoneal, and oral routes followed by blood sampling up to 24 h. Intraperitoneal systemic availability was 100%, but oral administration resulted in only 1.7% bioavailability. Gradual degradation of silvestrol was observed in mouse and human plasma, with approximately 60% of the parent drug remaining after 6 h. In rat plasma, however, silvestrol was completely converted to silvestric acid (SA) within 10 min. Evaluation in microsomes provided further evidence that the main metabolite formed was SA, which subsequently showed no cytotoxic or cytostatic activity in a silvestrol-sensitive lymphoblastic cell line. The ability of the analytical assay to measure tissue levels of silvestrol was evaluated in liver, brain, kidney, and spleen. Results indicated the method was capable of accurately measuring tissue levels of silvestrol and suggested it has a relatively low distribution to brain. Together, these data suggest an overall favorable pharmacokinetic profile of silvestrol in mice and provide crucial information for its continued development toward potential clinical testing.

Co-culture of the fungus Aspergillus fumigatus with the bacteria Streptomyces peucetius led to the induction of production of formyl xanthocillin analogues. This mixed fermentation yielded two new metabolites, fumiformamide (1) and N,N'-((1Z,3Z)-1,4-bis(4-methoxyphenyl)buta-1,3-diene-2,3-diyl)diformamide (2), together with two known N-formyl derivatives and the xanthocillin analogue BU-4704. The structures were determined by spectroscopic methods and by comparison with literature. Cytotoxic activity of all the analogues was tested on the NCI-60 cell line screen, and compound 2 exhibited significant activity against several cell lines. The analogues did not show antimicrobial activity.

Two new minor silvestrol analogues [2'''-episilvestrol (1) and 2''',5'''-diepisilvestrol (2)], together with a new 21-norbaccharane-type triterpene (3), two new 3,4-secodammarane triterpenes (4 and 5), and a new eudesmane sesquiterpene (6), as well as nine known compounds, were isolated from a large-scale re-collection of the CHCl(3)-soluble extract of the stem bark of Aglaia foveolata obtained in Kalimantan, Indonesia. The structures of the new compounds were established by interpretation of their spectroscopic data. All of the isolates were tested for cytotoxicity against HT-29 cells. The new silvestrol analogues, 1 and 2, were considerably less active as cytotoxic agents than silvestrol (7) and episilvestrol (5'''-episilvestrol) (8) against this cell line, showing the importance of the configuration at C-2''' in mediating such activity within this compound class. Several of the compounds isolated were also evaluated in a NF-κB (p65) inhibition assay.

Unlabelled: A significant number of astronauts sustain hand injuries during extravehicular activity training and operations. These hand injuries have been known to cause fingernail delamination (onycholysis) that requires medical intervention. This study investigated correlations between the anthropometrics of the hand and susceptibility to injury., Methods: The analysis explored the hypothesis that crewmembers with a high finger-to-hand size ratio are more likely to experience injuries. A database of 232 crewmembers' injury records and anthropometrics was sourced from NASA Johnson Space Center., Results: No significant effect of finger-to-hand size was found on the probability of injury, but circumference and width of the metacarpophalangeal (MCP) joint were found to be significantly associated with injuries by the Kruskal-Wallis test. A multivariate logistic regression showed that hand circumference is the dominant effect on the likelihood of onycholysis., Discussion: Male crewmembers with a hand circumference > 22.86 cm (9") have a 19.6% probability of finger injury, but those with hand circumferences < or = 22.86 cm (9") only have a 5.6% chance of injury. Findings were similar for female crewmembers. This increased probability may be due to constriction at large MCP joints by the current NASA Phase VI glove. Constriction may lead to occlusion of vascular flow to the fingers that may increase the chances of onycholysis. Injury rates are lower on gloves such as the superseded series 4000 and the Russian Orlan that provide more volume for the MCP joint. This suggests that we can reduce onycholysis by modifying the design of the current gloves at the MCP joint.

A new quassinoid, designated 2'-(R)-O-acetylglaucarubinone (1), and seven known quassinoids (2-8) were isolated, using bioactivity-guided separation, from the bark of Odyendyea gabonensis (Pierre) Engler [syn. Quassia gabonensis Pierre]. The structure of 1 was determined by spectroscopic analysis and by semisynthesis from glaucarubolone. Complete (1)H and (13)C NMR assignments of compounds 1-8 were also established from detailed analysis of two-dimensional NMR spectra, and the reported configurations in odyendene (7) and odyendane (8) were corrected. Compound 1 showed potent cytotoxicity against multiple cancer cell lines. Further investigation using various types of breast and ovarian cancer cell lines suggested that 1 does not target the estrogen receptor or progesterone receptor. When tested against mammary epithelial proliferation in vivo using a Brca1/p53-deficient mice model, 1 also caused significant reduction in mammary duct branching.

We developed a new model of hypodynamic loading to support mice in chronic conditions of partial weight bearing, enabling simulations of reduced gravity environments and related clinical conditions. The novel hardware allows for reduced loading between 10 and 80% of normal body weight on all four limbs and enables characteristic quadrupedal locomotion. Ten-week-old female BALB/cByJ mice were supported for 21 days under Mars-analog suspension (38% weight bearing) and compared with age-matched and jacketed (100% weight bearing) controls. After an initial adaptation, weight gain did not differ between groups, suggesting low levels of animal stress. Relative to age-matched controls, mice exposed to Mars-analog loading had significantly lower muscle mass (-23% gastrocnemius wet mass, P < 0.0001); trabecular and cortical bone morphology (i.e., trabecular bone volume: -24% at the distal femur, and cortical thickness: -11% at the femoral midshaft, both P < 0.001); and biomechanical properties of the femoral midshaft (i.e., -27% ultimate moment, P < 0.001). Bone formation indexes were decreased compared with age-matched full-weight-bearing mice, whereas resorption parameters were largely unchanged. Singly housed, full-weight-bearing controls with forelimb jackets were largely similar to age-matched, group-housed controls, although a few variables differed and warrant further investigation. Altogether, these data provide strong rationale for use of our new model of partial weight bearing to further explore the musculoskeletal response to reduced loading environments.

The global marine pharmaceutical pipeline consists of three Food and Drug Administration (FDA) approved drugs, one EU registered drug, 13 natural products (or derivatives thereof) in different phases of the clinical pipeline and a large number of marine chemicals in the preclinical pipeline. In the United States there are three FDA approved marine-derived drugs, namely cytarabine (Cytosar-U((R)), Depocyt((R))), vidarabine (Vira-A((R))) and ziconotide (Prialt((R))). The current clinical pipeline includes 13 marine-derived compounds that are either in Phase I, Phase II or Phase III clinical trials. Several key Phase III studies are ongoing and there are seven marine-derived compounds now in Phase II trials. The preclinical pipeline continues to supply several hundred novel marine compounds every year and those continue to feed the clinical pipeline with potentially valuable compounds. From a global perspective the marine pharmaceutical pipeline remains very active, and now has sufficient momentum to deliver several additional compounds to the marketplace in the near future; this review provides a current view of the pipeline.

Drugs from the sea? Darwin may not have considered this concept when he was thinking about mechanisms that drove diversification of life on earth. In recognition of his 200th year, and celebration of the publication in 1859 of his "On the origin of species", we review the global status of marine biodiscovery in medicinal fields, with a focus on the South Pacific. Furthermore, in the Darwinian spirit, we touch on putative evolutionary drivers and the chemical ecology of the successful leads. We argue that, for the relatively limited investment in effort to date, the success of marine leads as therapeutics promotes enhanced focus on marine biodiversity as a source of useful medicinal agents. The simple prime argument in support of this is the fact that we can exploit over four billion years of evolution in combinatorial chemistry in marine organisms, directed at relevant and effective biological activity.

This review discusses the role of microbial secondary metabolites produced by organisms from all three domains of life (the Archaea, Prokarya and Eukarya) as sources of pure natural products or derivatives of natural products, and as leads for novel synthetic compounds that may have the potential to ameliorate cancer. Drugs for which a microbe has either been identified as the producer of the active component or has been associated with its production based on circumstantial evidence are discussed. In addition, the impact of the increase in available genomic information and manipulation is discussed, along with some relevant examples, leading to the realization that the potential of microbes as sources of new leads/agents or as biological probes is large.

Numerous 'scaffolds' that have been identified in natural product structures have led to very significant numbers of approved drugs and drug candidates for a multiplicity of diseases over the years. In this mini-review, we discuss the base scaffolds (chemical skeletons) that we feel have produced very significant numbers of agents as drugs or drug leads and, in a number of cases, compounds that can be used as chemical synthons or that present activities in biological areas that were not obvious from their earlier history.

Dermatophyte infections, while not life-threatening, are very common, and there is great interest in developing new antifungal agents. Transcriptional profiling of Trichophyton on keratin has identified some antioxidant genes as induced on this host substrate, including a thioredoxin gene TmTRX1. If thioredoxin is a virulence factor, or necessary for the growth on keratin, thioredoxin inhibitors should act as antifungals. As a first evaluation of this hypothesis, we have tested the activity of a thioredoxin-inhibitory natural product, pleurotin, against a clinical isolate of each of two fungal pathogens: the dermatophyte T. mentagrophytes and Candida albicans. Pleurotin inhibited the growth of the dermatophyte in vitro and in an ex vivo skin model, but had no effect on Candida. It may be possible to develop and optimise thioredoxin inhibitors, some of which are already under study in cancer chemotherapy, as antifungals., (© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.)

Therapeutic options for advanced B-cell acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL) are limited. Available treatments can also deplete T lymphocytes, leaving patients at risk of life-threatening infections. In the National Cancer Institute cell line screen, the structurally unique natural product silvestrol produces an unusual pattern of cytotoxicity that suggests activity in leukemia and selectivity for B cells. We investigated silvestrol efficacy using primary human B-leukemia cells, established B-leukemia cell lines, and animal models. In CLL cells, silvestrol LC(50) (concentration lethal to 50%) is 6.9 nM at 72 hours. At this concentration, there is no difference in sensitivity of cells from patients with or without the del(17p13.1) abnormality. In isolated cells and whole blood, silvestrol is more cytotoxic toward B cells than T cells. Silvestrol causes early reduction in Mcl-1 expression due to translational inhibition with subsequent mitochondrial damage, as evidenced by reactive oxygen species generation and membrane depolarization. In vivo, silvestrol causes significant B-cell reduction in Emu-Tcl-1 transgenic mice and significantly extends survival of 697 xenograft severe combined immunodeficient (SCID) mice without discernible toxicity. These data indicate silvestrol has efficacy against B cells in vitro and in vivo and identify translational inhibition as a potential therapeutic target in B-cell leukemias.

Two new cytotoxic xanthones were isolated from extracts of the Madagascar rain forest plant Psorospermum cf. molluscum using bioassay-guided fractionation with the Escherichia coli SOS chromotest. The structures of the new dihydrofuranoxanthones, designated 3',4'-deoxy-4'-chloropsoroxanthin-(3',5'-diol) ( 1) and psoroxanthin ( 4), were determined on the basis of 2D-NMR, MS, and UV spectroscopic data and are structurally related to the psorospermins, a known class of plant antitumor agents. A new hydroxyprenylated xanthone ( 5) is also described. Xanthones 1 and 4 showed selective in vitro cytotoxicity against ABAE cells (bovine endothelial cell line).

The seven serotypes of botulinum neurotoxin (BoNTs) are zinc metalloproteases that cleave and inactivate proteins critical for neurotransmission. The synaptosomal protein of 25 kDa (SNAP-25) is cleaved by BoNTs A, C, and E, while vesicle-associated membrane protein (VAMP) is the substrate for BoNTs B, D, F, and G. BoNTs not only are medically useful drugs but also are potential bioterrorist and biowarfare threat agents. Because BoNT protease activity is required for toxicity, inhibitors of that activity might be effective for antibotulinum therapy. To expedite inhibitor discovery, we constructed a hybrid gene encoding (from the N terminus to the C terminus, with respect to the expressed product) green fluorescent protein, then a SNAP-25 fragment encompassing residues Met-127 to Gly-206, and then VAMP residues Met-1 to Lys-94. Cysteine was added as the C terminus. The expressed product, which contained the protease cleavage sites for all seven botulinum serotypes, was purified and coupled covalently through the C-terminal sulfhydryl group to maleimide-activated 96-well plates. The substrate was readily cleaved by BoNTs A, B, D, E, and F. Using this assay and an automated 96-well pipettor, we screened 528 natural product extracts for inhibitors of BoNT A, B, and E protease activities. Serotype-specific inhibition was found in 30 extracts, while 5 others inhibited two serotypes.

This chapter is designed to demonstrate that compounds derived from nature are still in the forefront of drug discovery in diseases such as microbial and parasitic infections, carcinomas of many types and control of cholesterol/lipids in man. In each disease area we have provided short discussions of past, present and future agents, in general only considering compounds currently in clinical Phase II or later, that were/are derived from nature's chemical skeletons. Finishing with a discussion of the current and evolving role(s) of microbes (bacteria and fungi) in the production of old and new agents ostensibly produced by higher organisms.

Unlabelled: Space suits significantly affect the metabolic cost of human movement during extravehicular activity, a key component of future human missions to the Moon and Mars. We hypothesized that space suit legs act as springs during running, thereby lowering cost of transport relative to space-suited walking., Methods: We transformed data from suited and unsuited energetics studies into a common format and developed a regression equation for specific resistance, S, (energy per weight per distance) based on the Froude number (a nondimensional parameter associated with gait transitions), surface slope, gravity, and space suit pressure. Acceptance criteria for regression factors included significance and a reduction in residual variance. We divided suited data into two groups, running and walking or slow running, and performed a group means hypothesis test and categorical regression of metabolic rate per unit weight and S, measures of time- and distance-associated metabolic efficiency, respectively., Results: The regression on S achieved an adjusted R2 of 0.83; all factors were significant (P < 0.0005). No additional evaluated factors met the acceptance criteria. The categorical regression, but not the hypothesis test, suggested that the running group had reduced efficiency per unit time; both tests suggested that the running group had increased efficiency per unit distance., Discussion: The regression model largely explained variations in S across studies. Several findings suggest that gas-pressure space suit legs function as springs during running, including the finding of higher efficiency per unit distance during running, despite the presumed increased work against space suit joint torques at higher velocities.

Metabolic costs limit the duration and intensity of extravehicular activity (EVA), an essential component of future human missions to the Moon and Mars. Energetics Framework: We present a framework for comparison of energetics data across and between studies. This framework, applied to locomotion, differentiates between muscle efficiency and energy recovery, two concepts often confused in the literature. The human run-walk transition in Earth gravity occurs at the point for which energy recovery is approximately the same for walking and running, suggesting a possible role for recovery in gait transitions. Muscular Energetics: Muscle physiology limits the overall efficiency by which chemical energy is converted through metabolism to useful work. Unsuited Locomotion: Walking and running use different methods of energy storage and release. These differences contribute to the relative changes in the metabolic cost of walking and running as gravity is varied, with the metabolic cost of locomoting at a given velocity changing in proportion to gravity for running and less than in proportion for walking. Space Suits: Major factors affecting the energetic cost of suited movement include suit pressurization, gravity, velocity, surface slope, and space suit configuration. Apollo lunar surface EVA traverse metabolic rates, while unexpectedly low, were higher than other activity categories. The Lunar Roving Vehicle facilitated even lower metabolic rates, thus longer duration EVAs. Muscles and tendons act like springs during running; similarly, longitudinal pressure forces in gas pressure space suits allow spring-like storage and release of energy when suits are self-supporting.

Marine invertebrate animals such as sponges, gorgonians, tunicates and bryozoans are sources of biomedicinally relevant natural products, a small but growing number of which are advancing through clinical trials. Most metazoan and anthozoan species harbour commensal microorganisms that include prokaryotic bacteria, cyanobacteria (blue-green algae), eukaryotic microalgae, and fungi within host tissues where they reside as extra- and intra-cellular symbionts. In some sponges these associated microbes may constitute as much as 40% of the holobiont volume. There is now abundant evidence to suggest that a significant portion of the bioactive metabolites thought originally to be products of the source animal are often synthesized by their symbiotic microbiota. Several anti-cancer metabolites from marine sponges that have progressed to pre-clinical or clinical-trial phases, such as discodermolide, halichondrin B and bryostatin 1, are thought to be products derived from their microbiotic consortia. Freshwater and marine cyanobacteria are well recognised for producing numerous and structurally diverse bioactive and cytotoxic secondary metabolites suited to drug discovery. Sea sponges often contain dominant taxa-specific populations of cyanobacteria, and it is these phytosymbionts (= photosymbionts) that are considered to be the true biogenic source of a number of pharmacologically active polyketides and nonribosomally synthesized peptides produced within the sponge. Accordingly, new collections can be pre-screened in the field for the presence of phytobionts and, together with metagenomic screening using degenerate PCR primers to identify key polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes, afford a biodiscovery rationale based on the therapeutic prospects of phytochemical selection. Additionally, new cloning and biosynthetic expression strategies may provide a sustainable method for the supply of new pharmaceuticals derived from the uncultured phytosymbionts of marine organisms.

Fractionation of cytotoxic extracts of specimens of a newly described sponge genus, Candidaspongia, has yielded the candidaspongiolides (3), a complex mixture of acyl esters of a macrolide related to tedanolide. The general structure of the candidaspongiolides was determined by analyses of various 2D NMR and MS data sets. The acyl ester components were identified by GC-MS analysis of the derived fatty acid methyl esters. The mixture could be selectively converted to the deacylated macrolide core (4) by enzymolysis with immobilized porcine lipase, with the structure of the candidaspongiolide core then secured by NMR and MS analysis. The candidaspongiolide mixture was potently cytotoxic, exhibiting a mean panel 50% growth inhibition (GI50) of 14 ng/mL in the National Cancer Institute's 60-cell-line in vitro antitumor screen.

This review is an updated and expanded version of two prior reviews that were published in this journal in 1997 and 2003. In the case of all approved agents the time frame has been extended to include the 251/2 years from 01/1981 to 06/2006 for all diseases worldwide and from 1950 (earliest so far identified) to 06/2006 for all approved antitumor drugs worldwide. We have continued to utilize our secondary subdivision of a "natural product mimic" or "NM" to join the original primary divisions. From the data presented, the utility of natural products as sources of novel structures, but not necessarily the final drug entity, is still alive and well. Thus, in the area of cancer, over the time frame from around the 1940s to date, of the 155 small molecules, 73% are other than "S" (synthetic), with 47% actually being either natural products or directly derived therefrom. In other areas, the influence of natural product structures is quite marked, with, as expected from prior information, the antiinfective area being dependent on natural products and their structures. Although combinatorial chemistry techniques have succeeded as methods of optimizing structures and have, in fact, been used in the optimization of many recently approved agents, we are able to identify only one de novo combinatorial compound approved as a drug in this 25 plus year time frame. We wish to draw the attention of readers to the rapidly evolving recognition that a significant number of natural product drugs/leads are actually produced by microbes and/or microbial interactions with the "host from whence it was isolated", and therefore we consider that this area of natural product research should be expanded significantly.

This review covers advances in the discovery, preclinical and clinical development of potential anticancer agents based upon the diterpenoid taxane skeleton. The anticancer properties of approved clinical agents of this class are not discussed, but the review documents how, 13 years post-approval of paclitaxel (Taxol), the base taxane structure is still utilized as the starting skeleton for molecules with improved pharmacological and toxicological properties. Paclitaxel may in fact be the first example of a 'tunable' anticancer agent. In addition, paclitaxel, and perhaps other taxanes in due course, has activities beyond the known antitumor indications, with an example being the use of paclitaxel-coated stents in cardiovascular therapies.

Kaposi's sarcoma (KS) and its causative agent, Kaposi's sarcoma associated herpesvirus (KSHV/HHV-8), a gamma2 herpesvirus, have distinctive geographical distributions that are largely unexplained. We propose the "oncoweed" hypothesis to explain these differences, namely that environmental cofactors present in KS endemic regions cause frequent reactivation of KSHV in infected subjects, leading to increased viral shedding and transmission leading to increased prevalence of KSHV infection as well as high viral load levels and antibody titers. Reactivation also plays a role in the pathogenesis of KSHV-associated malignancies. To test this hypothesis, we employed an in vitro KSHV reactivation assay that measured increases in KSHV viral load in KSHV infected primary effusion lymphoma (PEL) cells and screened aqueous natural product extracts from KS endemic regions. Of 4,842 extracts from 38 countries, 184 (5%) caused KSHV reactivation. Extracts that caused reactivation came from a wide variety of plant families, and extracts from Africa, where KSHV is highly prevalent, caused the greatest level of reactivation. Time course experiments were performed using 28 extracts that caused the highest levels of reactivation. The specificity of the effects on viral replication was examined using transcriptional profiling of all viral mRNAs. The array data indicated that the natural extracts caused an ordered cascade of lytic replication similar to that seen after induction with synthetic activators. These in vitro data provide support for the "oncoweed" hypothesis by demonstrating basic biological plausibility., ((c) 2006 Wiley-Liss, Inc.)

The US National Cancer Institute's natural products collection program has been running since 1986 and over the years the materials collected and processed have been stored in a repository that as a result of initial planning, has permitted the establishment of a national resource that is now being utilized as a drug discovery tool for any disease of interest to the NIH by researchers world-wide. This paper describes the history of the program.

Pleurotin is a naphthoquinone antibiotic originally isolated from Pleurotus griseus. Two pleurotin producing strains of Hohenbuehelia atrocaerulea have been identified, which, on solid substrate fermentation for 2 months yield 1-2 mg/l of the antibiotic. Described here is the lengthy developmental process which resulted in a production protocol being developed which reliably yields pleurotin from liquid fermentation at >300 mg/l. Critical to obtaining this increase in titer was inclusion in the media of an aqueous extract of alder wood.

The bystander effect is a process whereby the medium in which cells are irradiated at very low levels is presumed to contain a "low molecular weight" entity that will induce cell death and/or genetic changes in fresh mammalian cells when they are incubated in the medium. Following discussions at a recent meeting in McMaster University, suggestions are made in this paper as to the possibility for the "entity" to be nitric oxide and recommendations are given as to methods that will permit a systematic (bio)chemical search to be performed in order to identify the "activator" and prove/disprove the hypothesis.

Development of an outpatient finger-prick glomerular filtration rate (GFR) procedure suitable for epidemiological studies. In clinical practice, reference GFR procedures are rarely used; in large-scale research studies, a great deal of effort and experience is required to obtain them, which is a considerable disincentive to using GFR as an end point. The major problem for both clinical staff and the subject is the length of time that the procedure takes, requiring continuous attendance in the outpatient clinic or its vicinity. Using iohexol as a marker, we therefore propose an alternative approach, which addresses this fundamental deterrent to a more widespread use of GFR measurement. Eighty-two GFR measurements were performed in a mixture of healthy subjects and patients with differing degrees of renal impairment with a wide range of GFRs. Serum was obtained from blood samples to enable a reference GFR to be calculated. Blood spots were collected on filter paper at the same intervals (120, 180, and 240 min), allowed to dry, and then sent through the post. Serum and blood spots were analyzed simultaneously for each individual by automated reverse-phase high-pressure liquid chromatography. Standard linear regression analyses confirmed a good agreement (r2 = 0.953) between the iohexol serum GFR and iohexol blood spots GFR. Bland-Altman analysis confirmed that there was no concentration bias. Paired comparisons (Wilcoxon's paired signed rank test) showed no significant difference between the two measurements. Capillary sampling is simple, effective, and significantly reduces the time and costs of performing plasma clearance GFR measurements. This approach will make the GFR measurement more accessible for clinical practice and large-scale epidemiological studies may become feasible.

Over the last twenty-five to thirty years, exploration of the marine fauna and microbial flora has progressed from a random search by natural product chemists who liked to dive and wished to combine their hobby with their profession, to fully integrated programs of systemic investigation of the chemical agents elaborated by marine organisms of all phyla (as presumably defensive agents against predators) for their potential as leads to human-use drug candidates where the putative mechanisms have been identified as modulation of, and/or interaction with, potential molecular targets, rather than just exhibiting general cytotoxicity. This review is not exhaustive but is meant to cover the highlights of such agents and is arranged on a (nominal) target basis rather than by organism or chemical class.

While effective treatments exist for acute lymphocytic leukemia (ALL), particularly in the case of children, and for chronic mylogenous leukemia (CML), more efficacious treatments for other forms of acute and chronic forms of the disease are still needed. The National Cancer Institute has tested over 90,000 extracts of terrestrial plants and marine plants and invertebrates in its human cancer one-dose/60-cell-line prescreen, and the results for plants and marine organisms meeting criteria established for activity against selected leukemia cell lines are presented. Taxonomic data are limited to family and genus in the case of plants, and phylum for marine organisms, and those groups of organisms exhibiting significant activity (so-called "hot" families and genera) are discussed. The "hot" terrestrial plant families Myrsinaceae and Sapindaceae have not been studied to any extent and appear to merit special attention, although leukemia cell line selectivity is also noted for other families.

Although the use of natural products as leads to drugs waned in the early 1980s with the rise of combinatorial chemistry as a putative discovery tool, inspection of the chemical literature shows that research in natural products, in one guise or another, is alive and active and the 'chemical inspiration' from these privileged structures is leading to novel approaches in drug design and discovery. In this short article, we propose why we consider natural products are poised for a renaissance as tools for drug discovery.

Plant-derived compounds have been an important source of several clinically useful anti-cancer agents. These include vinblastine, vincristine, the camptothecin derivatives, topotecan and irinotecan, etoposide, derived from epipodophyllotoxin, and paclitaxel (taxol A number of promising new agents are in clinical development based on selective activity against cancer-related molecular targets, including flavopiridol and combretastin A4 phosphate, while some agents which failed in earlier clinical studies are stimulating renewed interest.

Objectives: To determine whether microalbuminuria is an independent prognostic factor for the development of diabetic complications and whether improved glycaemic or blood pressure control has a greater influence on the development of diabetic complications in those with microalbuminuria than in those with normoalbuminuria., Data Sources: Electronic databases up until January 2002., Review Methods: A protocol for peer review by an external expert panel was prepared that included selection criteria for data extraction and required two independent reviewers to undertake article selection and review. Completeness was assessed using hand-searching of major journals. Random effects meta-analysis was used to obtain combined estimates of relative risk (RR). Funnel plots, trim and fill methods and meta-regression were used to assess publication bias and sources of heterogeneity., Results: In patients with type 1 or type 2 DM and microalbuminuria there is a RR of all-cause mortality of 1.8 [95% confidence interval (CI) 1.5 to 2.1] and 1.9 (95% CI 1.7 to 2.1) respectively. Similar RRs were found for other mortality end-points, with age of cohort being inversely related to the RR in type 2 DM. In patients with type 1 DM, there is evidence that microalbuminuria or raised albumin excretion rate has only weak, if any, independent prognostic significance for the incidence of retinopathy and no evidence that it predicts progression of retinopathy, although strong evidence exists for the independent prognostic significance of microalbuminuria or raised albumin excretion rate for the development of proliferative retinopathy (crude RR of 4.1, 95% CI 1.8 to 9.4). For type 2 DM, there is no evidence of any independent prognostic significance for the incidence of retinopathy and little, if any, prognostic relationship between microalbuminuria and the progression of retinopathy or development of proliferative retinopathy. In patients with type 1 DM and microalbuminuria there is an RR of developing end-stage renal disease (ESRD) of 4.8 (95% CI 3.0 to 7.5) and a higher RR (7.5, 95% CI 5.4 to 10.5) of developing clinical proteinuria, with a significantly greater fall in glomerular filtration rate (GFR) in patients with microalbuminuria. In patients with type 2 DM, similar RRs were observed: 3.6 (95% CI 1.6 to 8.4) for developing ESRD and 7.5 (95% CI 5.2 to 10.9) for developing clinical proteinuria, with a significantly greater decline in GFR in the microalbuminuria group of 1.7 (95% CI 0.1 to 3.2) ml per minute per year compared with those who were normoalbuminuric. In adults with type 1 or type 2 DM and microalbuminuria at baseline, the numbers progressing to clinical proteinuria (19% and 24%, respectively) and those regressing to normoalbuminuria (26% and 18%, respectively) did not differ significantly. In children with type 1 DM, regression (44%) was significantly more frequent than progression (15%). In patients with type 1 or type 2 DM and microalbuminuria, there is scarce evidence as to whether improved glycaemic control has any effect on the incidence of cardiovascular disease (CVD), the incidence or progression of retinopathy, or the development of renal complications. However, among patients not stratified by albuminuria, improved glycaemic control benefits retinal and renal complications and may benefit CVD. In the effects of angiotensin-converting enzyme (ACE) inhibitors on GFR in normotensive microalbuminuric patients with type 1 DM, there was no evidence of a consistent treatment effect. There is strong evidence from 11 trials in normotensive type 1 patients with microalbuminuria of a beneficial effect of ACE inhibitor treatment on the risk of developing clinical proteinuria and on the risk of regression to normoalbuminuria. Patients with type 2 DM and microalbuminuria, whether hypertensive or not, may obtain additional cardiovascular benefit from an ACE inhibitor and there may be a beneficial effect on the development of retinopathy in normotensive patients irrespective of albuminuria. There is limited evidence that treatment of hypertensive microalbuminuric type 2 diabetic patients with blockers of the renin--angiotensin system is associated with preserved GFR, but also evidence of no differences in GFR in comparisons with other antihypertensive agents. The data on GFR in normotensive cohorts are inconclusive. In normotensive type 2 patients with microalbuminuria there is evidence from three trials (all enalapril) of a reduction in risk of developing clinical proteinuria; in hypertensive patients there is evidence from one placebo-controlled trial (irbesartan) of a reduction in this risk. Intensive compared with moderate blood pressure control did not affect the rate of progression of microalbuminuria to clinical proteinuria in the one available study. There is inconclusive evidence from four trials of any difference in the proportions of hypertensive patients progressing from microalbuminuria to clinical proteinuria when ACE inhibitors are compared with other antihypertensive agents, and in one trial regression was two-fold higher with lisinopril than with nifedipine., Conclusions: The most pronounced benefits of glycaemic control identified in this review are on retinal and renal complications in both normoalbuminuric and microalbuminuric patients considered together, with little or no evidence of any greater benefit in those with microalbuminuria. Hence, microalbuminuric status may be a false boundary when considering the benefits of glycaemic control. Classification of a person as normoalbuminuric must not serve to suggest that they will derive less benefit from optimal glycaemic control than a person who is microalbuminuric. All hypertensive patients benefit from blood pressure lowering and there is little evidence of additional benefit in those with microalbuminuria. Antihypertensive therapy with an ACE inhibitor in normotensive patients with microalbuminuria is beneficial. Monitoring microalbuminuria does not have a proven role in modulating antihypertensive therapy while the patient remains hypertensive. Recommendations for microalbuminuria research include: determining rate and predictors of development and factors involved in regression; carrying out economic evaluations of different screening strategies; investigating the effects of screening on patients; standardising screening tests to enable use of common reference ranges; evaluating the effects of lipid-lowering therapy; and using to modulate antihypertensive therapy.

The National Space Biomedical Research Institute (NSBRI) is supporting the National Aeronautics and Space Administration's (NASA) education mission through a comprehensive Education and Public Outreach Program (EPOP) that communicates the excitement and significance of space biology to schools, families, and lay audiences. The EPOP is comprised of eight academic institutions: Baylor College of Medicine, Massachusetts Institute of Technology, Morehouse School of Medicine, Mount Sinai School of Medicine, Texas A&M University, University of Texas Medical Branch Galveston, Rice University, and the University of Washington. This paper describes the programs and products created by the EPOP to promote space life science education in schools and among the general public. To date, these activities have reached thousands of teachers and students around the US and have been rated very highly., (c2005 Elsevier Ltd. All rights reserved.)

The objective of the present experiment was to investigate the effects of transportation, lairage, and preslaughter stressor treatment on glycolytic potential and pork quality of the glycolytic longissimus and the oxidative supraspinatus (SSP) or serratus ventralis (SV) muscles. In a 2 x 2 x 2 factorial design, 384 pigs were assigned randomly either to short (50 min) and smooth or long (3 h) and rough transport, long (3 h) or short (< 45 min) lairage, and minimal or high preslaughter stress. Muscle samples were taken from the LM at 135 min and from the SSP at 160 min postmortem for determination of the glycolytic potential and rate of glycolysis. At 23 h postmortem, pork quality was assessed in the LM and the SV. Effects of transport and lairage conditions were similar in both muscle types. Long transport increased (P < 0.01) the glycolytic potential and muscle lactate concentrations compared with short transport. Both long transportation and short lairage decreased (P < 0.01) redness (a* values) and yellowness (b* values) of the LM and SV. In combination with short lairage, long transport decreased (P < 0.05) pork lightness (lower L* values), and electrical conductivity was increased (P < 0.05) after long transport. Several interactions between stress level and muscle type (P < 0.001) were observed. High preslaughter stress decreased (P < 0.001) muscle glycogen in both the LM and SSP, but this decrease was greater in the LM. Lactate concentrations were increased (P < 0.001) only in the LM by high preslaughter stress. Increases in ultimate pH (P < 0.001) and decreases in a* values (P < 0.01) were greatest in the SV, whereas increases in electrical conductivity (P < 0.001) were greatest in the LM. The lack of interactions among transportation, lairage, and muscle type was attributed to the relatively minor differences in stress among treatments. It was concluded that, in glycolytic muscle types such as the LM, the high physical and psychological stress levels associated with stress in the immediate preslaughter period have a greater effect on the water-holding capacity of the meat and may promote PSE development. Conversely, oxidative muscle types tend to have higher ultimate pH values and produce DFD pork in response to intense physical activity and/or high psychological stress levels preslaughter.

Recent advances in the use of natural products and compounds derivedfrom natural products as agents for the treatment of cancer and other diseases are reviewed. The antitumor agents discussed include tubulin interactive agents, inhibitors of topoisomerases I and II, caspase activators, proteasome inhibitors, histone deacetylase inhibitors, heat shock protein 90 inhibitors, protein kinase inhibitors, and inhibitors of hypoxia inducible factor 1. It can be concluded that, despite a perceived lack of popularity in recent years, the use of natural product scaffolds in searching for drug leads is still being practiced.

As part of an initiative to discover functional natural product analogues of bleomycin guided by the use of the COMPARE algorithm, a CH(2)Cl(2)-MeOH extract prepared from Crypteronia paniculata was found to exhibit relaxation of supercoiled pSP64 DNA in the presence of Cu(2+). Bioassay-guided fractionation employing a DNA strand scission assay resulted in the isolation of three novel DNA cleavage agents. Their structures were elucidated as umbelactonyl cinnamate derivatives 1-3 through their NMR and MS spectral data analyses. This is the first example of the isolation and structural characterization of naturally occurring umbelactonyl cinnamate derivatives. Compound 1 exhibited strong Cu(2+)-dependent relaxation of supercoiled pSP64 DNA, while compounds 2 and 3 had only weak DNA cleavage activity.

The objectives of the present experiment were 1) to study the effects of transport conditions and lairage duration on stress level, muscle glycolytic potential, and pork quality; and 2) to investigate whether the negative effects of high stress immediately preslaughter are affected by preceding handling factors (transport and lairage). In a 2 x 2 x 2 factorial design, halothane-free pigs (n = 384) were assigned to either short (50 min) and smooth or long (3 h) and rough transport; long (3 h) or short (<45 min) lairage; and minimal or high preslaughter stress. Pigs were processed in eight groups (48 pigs per group) on various days at a commercial plant. Blood samples were taken at exsanguination to measure plasma cortisol and lactate concentrations. Muscle pH and temperature were measured at 30 and 40 min, respectively, and both were measured at 3 h, postmortem. A LM sample was taken 135 min postmortem to estimate glycogen content and rate of glycolysis. Pork quality attributes were assessed 23 h postmortem. Short transport increased cortisol when followed by short lairage (transport x lairage; P < 0.01). Long transport, but not lairage (P > 0.30), tended to increase (P = 0.06) muscle glycolytic potential. Long transport tended to increase (P = 0.08) electrical conductivity, and decreased a* (P < 0.01) and b* (P < 0.02) values. Decreasing lairage from 3 h to <45 min decreased (P < 0.05) the L* value, but it did not (P > 0.10) affect other pork quality traits. High stress decreased (P < 0.001) muscle glycolytic potential, and increased (P < 0.001) plasma lactate, cortisol, muscle temperature, rate of pH decline, and ultimate pH. Except for decreased (P < 0.001) b* values, pork color was not (P > 0.40) affected by high stress, but water-holding properties (measured by electrical conductivity, filter paper moisture, and drip loss) were impaired (P < 0.001) by high stress. Fiber optic-measured light scattering and Warner-Bratzler shear force were not (P > 0.12) affected by any treatment. Comparisons with the "optimal" handling (short transport, long lairage, and minimal stress) revealed that, with regard to water-holding properties, the negative effects of high stress were aggravated by suboptimal transport and lairage conditions. High stress alone increased electrical conductivity by 56%, whereas high stress in combination with short lairage led to an 88% increase. However, high preslaughter stress contributed most and was the major factor responsible for reductions in pork quality.