The marine environment is a rich source of biologically active molecules for the treatment of human diseases, especially cancer. The adaptation to unique environmental conditions led marine organisms to evolve different pathways than their terrestrial counterparts, thus producing unique chemicals with a broad diversity and complexity. So far, more than 36,000 compounds have been isolated from marine micro- and macro-organisms including but not limited to fungi, bacteria, microalgae, macroalgae, sponges, corals, mollusks and tunicates, with hundreds of new marine natural products (MNPs) being discovered every year. Marine-based pharmaceuticals have started to impact modern pharmacology and different anti-cancer drugs derived from marine compounds have been approved for clinical use, such as: cytarabine, vidarabine, nelarabine (prodrug of ara-G), fludarabine phosphate (pro-drug of ara-A), trabectedin, eribulin mesylate, brentuximab vedotin, polatuzumab vedotin, enfortumab vedotin, belantamab mafodotin, plitidepsin, and lurbinectedin. This review focuses on the bioactive molecules derived from the marine environment with anticancer activity, discussing their families, origin, structural features and therapeutic use. 相似文献
The soil organic carbon (SOC) pool of the Northern Hemisphere contains about half of the global SOC stored in soils. As the Arctic is exceptionally sensitive to global warming, temperature rise and prolonged summer lead to deeper thawing of permafrost‐affected soils and might contribute to increasing greenhouse gas emissions progressively. To assess the overall feedback of soil organic carbon stocks (SOCS) to global warming in permafrost‐affected regions the spatial variation in SOCS at different environmental scales is of great interest. However, sparse and unequally distributed soil data sets at various scales in such regions result in highly uncertain estimations of SOCS of the Northern Hemisphere and here particularly in Greenland. The objectives of this study are to compare and evaluate three controlling factors for SOCS distribution (vegetation, landscape, aspect) at two different scales (local, regional). The regional scale reflects the different environmental conditions between the two study areas at the coast and the ice margin. On the local scale, characteristics of each controlling factor in form of defined units (vegetation units, landscape units, aspect units) are used to describe the variation in the SOCS over short distances within each study area, where the variation in SOCS is high. On a regional scale, we investigate the variation in SOCS by comparing the same units between the study areas. The results show for both study areas that SOCS are with 8 kg m?2 in the uppermost 25 cm and 16 kg m?2 in the first 100 cm of the soil, i.e., 3 to 6 kg m?2 (37.5%) higher than existing large scale estimations of SOCS in West Greenland. Our approach allows to rank the scale‐dependent importance of the controlling factors within and between the study areas. However, vegetation and aspect better explain variations in SOCS than landscape units. Therefore, we recommend vegetation and aspect for determining the variation in SOCS in West Greenland on both scales. 相似文献
Human appropriation of net primary productivity (HANPP) is employed as a measure of human pressures on biodiversity, though largely at global and national scales rather than landscape to regional scales where many conservation decisions take place. Though gaining in familiarity, HANPP is not widely utilized by conservation professionals.
Objectives
This study, encompassing the US side of the Great Lakes basin, examines how regional distributions of HANPP relate to landscape-based biodiversity proxy metrics used by conservation professionals. Our objectives were (1) to quantify the HANPP of managed lands at the county scale; and (2) to assess spatial patterns of HANPP in comparison to landscape diversity and local habitat connectedness to determine if the metric can provide useful information to conservation professionals.
Methods
We aggregated forest and cropland NPP data between 2005 and 2015 and coupled it with previously published potential vegetation maps to quantify the HANPP of each county in the study region. We mapped the outputs at 500 m resolution to analyze spatial relationships between HANPP and landscape metrics of biodiversity potential.
Results
Area-weighted HANPP across our study region averaged 45% of NPP, down to 4.9% in forest-dominated counties. Greater HANPP correlated with reduced landscape diversity (p?<?0.001, r2?=?0.28) and reduced local habitat connectedness (p?<?0.001, r2?=?0.36).
Conclusion
HANPP could be used as an additional tool for conservation professionals during regional-scale land use planning or conservation decision-making, particularly in mixed-use landscapes that both support important biodiversity and have high levels of primary production harvest.
The aim of the present study was to investigate the organisation of the genes (cps) involved in biosynthesis the capsular polysaccharide (CPS) of Actinobacillus pleuropneumoniae serotypes 6, 7, and 12 and to compare these to the corresponding genes previously described in other A. pleuropneumoniae serotypes. In serotypes 6 and 7 the sequenced DNA regions comprised five and four open reading frames, respectively, designated cps6ABCDE and cps7ABCD, whereas the sequenced DNA region in serotype 12 comprised only two open reading frames designated cps12AB. At the amino acid level, CpsA, CpsB, and CpsC of A. pleuropneumoniae serotypes 2, 6, 7, and 8 contained a high degree of homology. At the amino acid level Cps6D revealed a high degree of homology to Cps8D, whereas Cps7D contained a high degree of homology to the Cps2D. The deduced gene product of the partially sequenced cps6E gene showed no homology to any deduced gene products of any cps genes of A. pleuropneumoniae investigated so far. None of the deduced gene products of the cps genes involved in encapsulation of A. pleuropneumoniae serotypes 2, 6, 7, and 8 revealed homology to the deduced gene products of the cps genes of serotypes 1, 5A, and 12. For some genes, a local homology was found to genes probably involved in teichoic acid synthesis in other bacteria. The results obtained revealed a high degree of homology among the genes involved in CPS biosynthesis for serotypes 2, 6, 7, and 8 and a different group of homologous cps genes for serotypes 1 and 12. In some serotype 7 strains, including the serotype 7 reference strain, WF83, the cps genes were not located adjacent to the genes responsible for CPS export (cpx), probably due to genetic rearrangements. 相似文献
Cooperative programs with agribusiness offer opportunities for colleges of veterinary medicine to expand their instructional programs in agricultural practice. Agribusinesses associated with livestock agriculture recognize the importance of veterinary medicine in maintaining a vibrant and successful industry. Stewardship of corporate support involves close communication with advocates within the companies, providing them with documentation of the potential effects of corporate investments. This article describes the creation of the Michigan State University (MSU) Training Center for Dairy Professionals, a key aspect of which was the identification of innovative and productive areas of mutual interest and benefit. In addition to supporting the dairy industry by training veterinary students, the program offers specific benefits to investors, including the use of MSU facilities and direct participation in veterinary instruction. 相似文献
The influence of dietary restriction on the negative feedback potency of 17-beta-estradiol (E2) was evaluated in both castrated male (wethers) and female sheep (OVX ewes) during the breeding season. In study 1, OVX ewes received maintenance or restricted dietary energy for 7 weeks or maintenance energy for 6 weeks prior to a 5 day fast (n=12ewes/feeding group). Estradiol (0.31microg E2/50kg/h) or vehicle (10% EtOH-saline) was continuously infused into half the animals in each dietary treatment for the final 54h of the study. The dynamic pattern of LH secretion was assessed during the final 6h of infusion. Estradiol inhibited luteinizing hormone (LH) pulse amplitude independent of nutrition (P=0.02); fasting increased mean LH, LH peak height, and LH nadir in the absence of E2 (P=0.004, P=0.02, and P=0.02, respectively); while E2 inhibited pulse frequency (P=0.02) and increased peak width (P=0.04) in restricted ewes. Interestingly, despite uniform E2 delivery, serum concentrations of E2 differed with feeding status. Therefore, 12 wethers were infused with 0.31microg E2/50kg/h (6 fed, 6 fasted) and six wethers received 0.19microg E2/50kg/h (fasted) to establish similar serum concentrations of E2 in fed (0.31microg/50kg/h) and fasted (0.19microg/50kg/h) wethers. When fed and fasted wethers had uniform serum concentrations of E2 LH pulse frequency was suppressed (P<0.05) in fasted relative to fed animals, supporting the postulate that energy restriction enhances the E2 negative feedback potency. Collectively, these studies demonstrate that nutrition affects E2 feedback potency and clearance. 相似文献
In the horse, the body condition score (BCS) system to assess subcutaneous fat deposition is a useful tool for making feeding management decisions. The system includes assessing fat deposition at six body areas (neck, withers, shoulders, ribs, loin, and tail head) and was developed in Quarter Horse mares. It has not been tested for use on other breeds or genders, possibly compromising the system's ability to describe fat accretion in other classes of horse. The objective of this study was to examine the ability of the previously developed fat accretion characteristics to describe fat deposition in mature Thoroughbred (TB) geldings. An additional goal was to determine whether fewer body areas could be used. Fifteen mature TB geldings were fed for weight gain over an 8-month period on one of two diets and were independently assessed for BCS on a monthly basis by two judges. BCS was determined by averaging the scores that were assigned to each of the six body areas. Fat accretion characteristics were also recorded. Across both diets, the neck area scored significantly higher than the withers and loin (P < 0.05) throughout the study. A BCS derived only from the body areas of neck, shoulders, ribs, and tailhead was found to accurately predict the six body area−derived mean BCS. The results of this study provide justification for modifications of the BCS system for use in TB geldings and also demonstrated that fewer body areas can be used to accurately predict mean BCS. 相似文献