ABSTRACT
High-mountain plant communities are strongly determined by abiotic conditions, especially low temperature, and are therefore susceptible to effects of climate warming. Rising temperatures, however, also lead to increased evapotranspiration, which, together with projected shifts in seasonal precipitation patterns, could lead to prolonged, detrimental water deficiencies. The current study aims at comparing alpine plant communities along elevation and water availability gradients from humid conditions (north-eastern Alps) to a moderate (Central Apennines) and a pronounced dry period during summer (Lefka Ori, Crete) in the Mediterranean area. We do this in order to (1) detect relationships between community-based indices (plant functional leaf and growth traits, thermic vegetation indicator, plant life forms, vegetation cover and diversity) and soil temperature and snow duration and (2) assess if climatic changes have already affected the vegetation, by determining directional changes over time (14-year period; 2001-2015) in these indices in the three regions. Plant community indices responded to decreasing temperatures along the elevation gradient in the NE-Alps and the Apennines, but this elevation effect almost disappeared in the summer-dry mountains of Crete. This suggests a shift from low-temperature to drought-dominated ecological filters. Leaf trait (Leaf Dry Matter Content and Specific Leaf Area) responses changed in direction from the Alps to the Apennines, indicating that drought effects already become discernible at the northern margin of the Mediterranean. Over time, a slight increase in vegetation cover was found in all regions, but thermophilisation occurred only in the NE-Alps and Apennines, accompanied by a decline of cold-adapted cushion plants in the Alps. On Crete, xeromorphic shrubs were increasing in abundance. Although critical biodiversity losses have not yet been observed, an intensified monitoring of combined warming-drought impacts will be required in view of threatened alpine plants that are either locally restricted in the south or weakly adapted to drought in the north.
Subject(s)
Climate , Plants , Biodiversity , Climate Change , Ecosystem , WaterABSTRACT
Mountain ecosystems are sensitive and reliable indicators of climate change. Long-term studies may be extremely useful in assessing the responses of high-elevation ecosystems to climate change and other anthropogenic drivers from a broad ecological perspective. Mountain research sites within the LTER (Long-Term Ecological Research) network are representative of various types of ecosystems and span a wide bioclimatic and elevational range. Here, we present a synthesis and a review of the main results from ecological studies in mountain ecosystems at 20 LTER sites in Italy, Switzerland and Austria covering in most cases more than two decades of observations. We analyzed a set of key climate parameters, such as temperature and snow cover duration, in relation to vascular plant species composition, plant traits, abundance patterns, pedoclimate, nutrient dynamics in soils and water, phenology and composition of freshwater biota. The overall results highlight the rapid response of mountain ecosystems to climate change, with site-specific characteristics and rates. As temperatures increased, vegetation cover in alpine and subalpine summits increased as well. Years with limited snow cover duration caused an increase in soil temperature and microbial biomass during the growing season. Effects on freshwater ecosystems were also observed, in terms of increases in solutes, decreases in nitrates and changes in plankton phenology and benthos communities. This work highlights the importance of comparing and integrating long-term ecological data collected in different ecosystems for a more comprehensive overview of the ecological effects of climate change. Nevertheless, there is a need for (i) adopting co-located monitoring site networks to improve our ability to obtain sound results from cross-site analysis, (ii) carrying out further studies, in particular short-term analyses with fine spatial and temporal resolutions to improve our understanding of responses to extreme events, and (iii) increasing comparability and standardizing protocols across networks to distinguish local patterns from global patterns.
ABSTRACT
BACKGROUND: During the 20th century medical education has been preoccupied largely with discussions of the venues and methods for teaching. Little attention has been paid to what should be learned about the scientific paradigm underlying research and practice. A 17th century model has gradually produced a technically efficient but increasingly narrow, monocausal, reductionistic view of health and disease. This "belief system" fails to accommodate or explain the meaning and impact on patients' health of diverse internal and external experiences and influences. During this period new physics and systemic views of biosystems have extended the Newtonian scientific paradigm beyond its materialistic boundaries, which still determines most of the medical sciences. METHODS: A broad range of historical and contemporary scientific literature is examined in support of four central questions addressed in this three-part series: Is there a reason to examine these matters now? How is medical scientific thinking influenced by the general reorientation of science during the 20th century? Is there is a reason to examine the impact of these changes on medicine now? Will a change of paradigm affect medical practice, research, and education? RESULTS: The extraordinarily productive contemporary biomedical model should be expanded to include meaningful information about how each patient's experiences impinge on health status. CONCLUSIONS: Family physicians, together with collaborators in the biological and behavioral sciences and other health professionals, should undertake rigorous research to establish the validity of the expanded paradigm espoused. Its impact could be profound on practice, research, education, and policies.
ABSTRACT
BACKGROUND: During the 20th century medical education has been largely preoccupied with discussions of the venues and methods for teaching. Little attention has been paid to what should be learned about the scientific paradigm underlying research and practice. A 17th century model has gradually produced an increasingly narrow, monocausal, reductionistic view of health and disease. Much good has resulted, but this "belief system" fails to accommodate or explain the meaning and impact on patients' health of diverse internal and external experiences and influences. During this period quantum mechanics and its ever-expanding capacity to accommodate new information and enhance understanding have superseded Newtonian physics in much scientific thinking. METHODS: A broad range of historical and contemporary scientific literature is examined in support of four central questions in this three-part series: (1) Are there reasons to examine these matters now? (2) How is medical scientific thinking influenced by the general reorientation of science during the 20th century? (3) Are there reasons now to examine the impact of these changes on medicine? (4) Will a change of paradigm affect medical practice, research, and education? RESULTS: The extraordinarily productive contemporary biomedical model should be expanded beyond the physical and biological to incorporate meaningful information about how each patient's experiences impinge on health status. CONCLUSIONS: Family and other primary care physicians together with collaborators in the biological and behavioral sciences and other health professions should undertake rigorous research to establish the validity of the expanded paradigm espoused. Its impact on practice, research, education, and policies could be profound.
ABSTRACT
BACKGROUND: During the 20th century medical education has been largely preoccupied with discussions of the venues and methods for teaching. Little attention has been paid to what should be learned about the scientific paradigm underlying research and practice. A 17th century model has gradually produced an increasingly narrow, monocausal, reductionistic view of health and disease. Much good has resulted, but this "belief system" fails to accommodate or explain the meaning and impact on patients' health of diverse internal and external experiences and influences. During this period quantum mechanics and its ever-expanding capacity to accommodate new information and enhance understanding have superseded Newtonian physics in much scientific thinking. METHODS: A broad range of historical and contemporary scientific literature is examined in support of four central questions in this three-part series: (1) Are there reasons to examine these matters now? (2) How is medical scientific thinking influenced by the general reorientation of science during the 20th century? (3) Are there reasons now to examine the impact of these changes on medicine? (4) Will a change of paradigm affect medical practice, research, and education? RESULTS: The extraordinarily productive contemporary biomedical model should be expanded beyond the physical and biological to incorporate meaningful information about how each patients experiences impinge on health status. CONCLUSIONS: Family and other primary care physicians together with collaborators in the biological and behavioral sciences and other health professions should undertake rigorous research to establish the validity of the expanded paradigm espoused. Its impact on practice, research, education, and policies could be profound.
ABSTRACT
Alkaloids derived from the tetrahydrobenzylisoquinoline alkaloid (S)-N-methylcoclaurine represent a vast and varied structural array of physiologically active molecules. These compounds range from the dimeric bisbenzylisoquinolines, such as the muscle relaxant (+)-tubocurarine, to the powerful anaesthetic opiate morphine, the antimicrobial berberine and the anti-microbial benzo[c]-phenanthridine sanguinarine. The 3'-hydroxylation of (S)-N-methylcoclaurine is a branch point that is the penultimate step in the biosynthesis of the central alkaloidal intermediate (S)-reticuline. This study identified this enzyme as a cytochrome P-450-dependent mono-oxygenase that has until now eluded attempts at identification using in vitro enzyme assays. Two alleles encoding this new enzyme (S)-N-methylcoclaurine 3'-hydroxylase (CYP80B1) were isolated from a cDNA library prepared from poly(A)+ RNA isolated from methyl jasmonate-induced cell-suspension cultures of the California poppy Eschscholzia californica. Partial clones generated by RT-PCR with cytochrome P-450-specific primers were used as hybridization probes. RNA gel-blot hybridization indicated that the transcripts for CYP80B1 accumulate in response to the addition of methyl jasmonate to the cell culture medium. Both alleles were functionally expressed in Saccharomyces cerevisiae and in Spodoptera frugiperda Sf9 cells in the presence and absence of the E. californica cytochrome P-450 reductase. The enzyme was found to hydroxylate exclusively (S)-N-methylcoclaurine with a pH optimum of 7.5, temperature optimum of 35 degrees C and K(m) of 15 microns. In addition to the CYP80B1 alleles, another cytochrome P-450 with an inducible transcript (CYP82B1) was isolated and expressed in the same manner, but was not found to be involved in alkaloid biosynthesis in this plant.
Subject(s)
Alcohol Oxidoreductases/genetics , Cytochrome P-450 Enzyme System/genetics , Genes, Plant , Plants/enzymology , Plants/genetics , Alcohol Oxidoreductases/metabolism , Alkaloids/biosynthesis , Alleles , Animals , Base Sequence , Cell Line , Cloning, Molecular , Cytochrome P-450 Enzyme System/metabolism , DNA, Complementary/genetics , DNA, Complementary/isolation & purification , DNA, Plant/genetics , DNA, Plant/isolation & purification , Gene Expression , Molecular Sequence Data , Saccharomyces cerevisiae/genetics , Spodoptera , Substrate Specificity , Terminology as TopicABSTRACT
A genomic clone, bbe1 was isolated that encodes the methyl jasmonate-inducible berberine bridge enzyme of antimicrobial benzophenanthridine alkaloid biosynthesis in the California poppy Eschscholzia californica. Genomic DNA gel blot analysis indicates that two genes are present in the E. californica genome that code for the berberine bridge enzyme reading frame. Each coding region is apparently preceeded by a unique promoter sequence. The bbe1 gene contains no introns and one transcriptional start site. A 41 nucleotide region between -496 and -455 of the 5'-flanking region appears to be essential for promoter activity in E. californica. The promoter displayed an unexpectedly high species specificity, being active in only E. californica and Thalictrum bulgaricum, out of 28 cell suspension cultures tested.
Subject(s)
Genes, Plant , Oxidoreductases, N-Demethylating/genetics , Papaver/enzymology , Papaver/genetics , Plants, Medicinal , Amino Acid Sequence , Base Sequence , California , Cloning, Molecular , Genome, Plant , Molecular Sequence Data , Oxidoreductases, N-Demethylating/biosynthesis , Recombinant Proteins/biosynthesisABSTRACT
Cytochrome P450 reductase was purified to homogeneity from cell suspension cultures of the opium poppy Papaver somniferum, the enzyme was characterized (K(m) cytochrome c, 8.3 microM; K(m) NADPH, 4.2 microM; pH optimum, 8.0; M(r), 80 kDa), and the amino acid sequence of internal peptides was determined. Partial cDNA clones from P. somniferum and from Eschscholzia californica (California poppy) were then generated using the polymerase chain reaction and were used as hybridization probes to isolate full-length cDNAs. The Papaver and Eschscholzia cytochrome P450 reductases are 63% identical at the nucleotide level and 69% identical at the amino acid level. SDS-PAGE of the purified native P. somniferum enzyme as well as genomic DNA gel blot analysis indicate that two cytochrome P450 reductase isoforms are present in each species. This evidence is also supported by translation of nucleotide sequences obtained from the PCR-generated partial cDNAs and the full-length cDNAs isolated from lambda libraries. The Papaver and Eschscholzia cytochrome P450 reductases were functionally expressed in the yeast Saccharomyces cerevisiae and in the insect cell culture Spodoptera frugiperda Sf9. Coexpression of cytochrome P450 reductase with the C-O phenol coupling cytochrome P450 of bisbenzylisoquinoline alkaloid biosynthesis in Berberis stolonifera, berbamunine synthase (CYP80A1), in insect cell culture resulted in an alteration of the product profile as compared to that obtained by expression of berbamunine synthase in the absence of plant reductase.
Subject(s)
NADPH-Ferrihemoprotein Reductase/chemistry , NADPH-Ferrihemoprotein Reductase/genetics , Papaver/enzymology , Plants, Medicinal , Alcohol Oxidoreductases/genetics , Alcohol Oxidoreductases/metabolism , Alkaloids/biosynthesis , Alkaloids/metabolism , Amino Acid Sequence , Animals , Cell Line , Cloning, Molecular , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/metabolism , Electrophoresis, Polyacrylamide Gel , Gene Expression , Metalloendopeptidases/metabolism , Molecular Sequence Data , Molecular Structure , NADPH-Ferrihemoprotein Reductase/isolation & purification , NADPH-Ferrihemoprotein Reductase/metabolism , Peptide Fragments/chemistry , Recombinant Proteins/chemistry , Recombinant Proteins/metabolism , Saccharomyces cerevisiae/genetics , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Spodoptera/geneticsABSTRACT
Contemporary medical education is determined by an increasing proliferation and disintegration of disciplines within medical schools. This development runs against an emerging scientific understanding of the integrated nature of living systems, initiated by the recent developments in physics. Undergraduate medical education aimed to meet the demands of our society will have to be based on modern systemic science and today's priority health problems and not on academically established disciplines.
Subject(s)
Curriculum/standards , Education, Medical, Undergraduate/standards , Clinical Competence , Family Practice/education , Humans , Physician-Patient Relations , Science , Sociology/educationABSTRACT
Linear approximations to the whiteness and tint formulas of the Commission Internationale de l'Eclairage (CIE) are presented in the CIE L*a*b* color system.
ABSTRACT
In the present study we tested the effect of immunization with schistosome derived antigens such as frozen-thawed schistosomula in combination with either BCG, liposomes or liposomal muramyl tripeptide-phosphatidyl ethanolamine (MTP-PE), on the resistance of mice to infection, and on the function of their macrophages and lymphocytes. Immunization with either F-T schistosomula + BCG or F-T schistosomula + MTP-PE and subsequent infection, resulted in a 2-3-fold increase in adherent peritoneal macrophage-mediated schistosomulicidal activity (SCA). Peritoneal and spleen macrophages from immunostimulant treated and/or immunized animals showed a significant increase in LPS triggered TNF-alpha production, as compared to non-treated controls. The highest increase in TNF-alpha production was achieved after immunization with either F-T schistosomula + BCG or F-T schistosomula + MTP-PE. LPS triggered IL-1 production was elevated in spleen and peritoneal macrophages from F-T schistosomula + BCG treated mice, and also in spleen macrophages treated with F-T schistosomula + MTP-PE. Only immunization with F-T schistosomula + BCG increased ConA-induced spleen lymphocyte proliferation and IL-2 production. Immunization of mice with F-T schistosomula + BCG also induced protection against parasite infection, while F-T schistosomula + MTP-PE failed to do so. Potentiation of antischistosomal resistance seems to require both macrophage and lymphocyte activation which was achieved only when BCG served as an immunostimulant.
Subject(s)
Interleukin-1/biosynthesis , Interleukin-2/biosynthesis , Schistosomiasis mansoni/immunology , Tumor Necrosis Factor-alpha/biosynthesis , Adjuvants, Immunologic/administration & dosage , Animals , Antigens, Helminth/administration & dosage , BCG Vaccine/administration & dosage , Immunization , Lymphocyte Activation , Macrophage Activation , Male , Mice , Mice, Inbred ICR , Peritoneal Cavity/cytology , Schistosoma mansoni/immunology , Schistosomiasis mansoni/prevention & control , Spleen/immunologyABSTRACT
Production of TNF-alpha and IL-1 by adherent peritoneal exudate macrophages (APEM) was monitored for 20 weeks in Schistosoma mansoni infected mice in comparison to their schistosomulicidal activity. LPS-triggered IL-1 and TNF-alpha production by APEM peaked 10 weeks post infection (p.i.) and declined thereafter. The schistosomulicidal activity of APEM also peaked after 10 weeks but remained elevated thereafter. Infected mice were also treated with the immunostimulator liposomal muramyl tripeptide-phosphatidyl ethanolamine (MTP-PE) 6 or 10 weeks p.i., and their APEM were tested 4 weeks later. APEM from such treated animals showed elevated IL-1 and TNF-alpha production when treatment commenced 6 weeks p.i., while their schistosomulicidal activity increased when treatment commenced either 6 or 10 weeks p.i. The L-arginine inhibitor, NG monomethyl arginine, markedly inhibited the schistosomulicidal activity but not the IL-1 and TNF-alpha production of APEM. Our results show that monokine production increases during the acute phase of infection and declines during its chronic phase, while macrophage schistosomulicidal activity remains constant throughout. Furthermore, TNF-alpha or IL-1 may play a minor role in APEM mediated killing of schistosomula.
Subject(s)
Acetylmuramyl-Alanyl-Isoglutamine/analogs & derivatives , Interleukin-1/biosynthesis , Macrophages/immunology , Phosphatidylethanolamines/pharmacology , Schistosoma mansoni/immunology , Tumor Necrosis Factor-alpha/biosynthesis , Acetylmuramyl-Alanyl-Isoglutamine/administration & dosage , Acetylmuramyl-Alanyl-Isoglutamine/pharmacology , Acetylmuramyl-Alanyl-Isoglutamine/therapeutic use , Adjuvants, Immunologic/pharmacology , Animals , Arginine/analogs & derivatives , Arginine/pharmacology , Biological Assay , Cells, Cultured , Drug Carriers , Immunity, Cellular , Interleukin-2/biosynthesis , Liposomes , Macrophages/drug effects , Male , Mice , Mice, Inbred ICR , Peritoneum/cytology , Phosphatidylethanolamines/administration & dosage , Phosphatidylethanolamines/therapeutic use , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/immunology , Spleen/drug effects , Spleen/immunology , Time Factors , omega-N-MethylarginineABSTRACT
Schistosomiasis is a chronic disease afflicting hundreds of millions of people throughout the world against which there is as yet no effective vaccine. In the present study we tested the effect of the immunomodulator muramyl tripeptide phosphatidyl ethanolamine (MTP-PE) on the survival of Schistosoma mansoni-infected mice and on the induction in them of schistosomulicidal macrophages. Mice exposed to 80 cercariae each and then treated with MTP-PE showed prolonged survival following either single or repeat infection. The treatment with MTP-PE, when initiated 70 days post the schistosome infection, diminished significantly the mortality of infected mice over an observed period of 110 days. In terms of treatment efficacy there was no evident difference between the intravenous and intraperitoneal mode of administration of the drug. MTP-PE treatment significantly reduced granuloma size and markedly diminished liver damaged as judged by the lower levels of alkaline phosphatase in the serum. Such treatment exerted no significant effect on the spleen or liver weight in infected mice nor on the worm burden resulting from either a single or double infection. In infected and non-treated mice, schistosomulicidal macrophages appeared after 8-10 weeks of infection. In infected mice treated with MTP-PE there was an accelerated appearance of such macrophages and these exhibited a greater cidal effect on the schistosomula. These immunostimulatory and life-prolonging effects of MTP-PE on S. mansoni-infected mice might indicate an effect of this reagent on cells involved in the granulomatous process.
Subject(s)
Acetylmuramyl-Alanyl-Isoglutamine/analogs & derivatives , Macrophages/immunology , Phosphatidylethanolamines/pharmacology , Schistosoma mansoni/immunology , Schistosomiasis mansoni/immunology , Acetylmuramyl-Alanyl-Isoglutamine/pharmacology , Adjuvants, Immunologic , Alkaline Phosphatase/blood , Animals , Cytotoxicity, Immunologic , Granuloma/parasitology , Liver Diseases, Parasitic/parasitology , Male , Mice , Mice, Inbred ICR , Schistosomiasis mansoni/parasitologyABSTRACT
An acute manifestation of a chronic brucellosis localised to the female breast is described. A granulomatous mastitis was identified on histological examination. To our knowledge, this is the first reported occurrence of this phenomenon. It is pointed out that it is clinically difficult to distinguish this type of infection from an inflammatory carcinoma of the breast.
Subject(s)
Brucellosis/pathology , Granuloma, Giant Cell/pathology , Mastitis/pathology , Abscess/pathology , Breast/pathology , Diagnosis, Differential , Female , Humans , Middle AgedSubject(s)
Family Practice , Health , Humans , Interprofessional Relations , Medicine , Research , SpecializationABSTRACT
[4-(3-Bromoacetylpyridinio)-butyl]adenosine pyrophosphate as a structural analog of NAD+ reacts covalently with the sulfhydryl groups of thiopropyl agarose. 10-20 mumol can be bound to 1 ml gel. Stabilization of the insoluble coenzyme is attained by treatment with sodium boro hydride (NaBH4). This complex when applied to column chromatography, allows the separation of various dehydrogenases as a result of their different complex stability coefficients. Alcohol dehydrogenase from liver, lactate dehydrogenase, and adenylate kinase, which all bind to the ADP-analog residues of the gel matrix, can thus be separated by different salt gradients. Alcohol dehydrogenase from yeast, however, does not form a complex and can easily be eluted from the column with phosphate buffer. Glyceraldehyde-3 phosphate and aldehyde dehydrogenases can be eluted by the addition of NAD+ or NADH to the buffer. The uncharged 1,4-dihydropyridine ring of the reduced coenzyme produces a more stable complex with the dehydrogenases than the oxidized form.