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Piri T, Saarinen M, Hamberg L, Hantula J, Gaitnieks T. Efficacy of Biological and Chemical Control Agents against Heterobasidion Spore Infections of Norway Spruce and Scots Pine Stumps on Drained Peatland. J Fungi (Basel) 2023; 9:jof9030346. [PMID: 36983514 PMCID: PMC10053854 DOI: 10.3390/jof9030346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/08/2023] [Accepted: 03/09/2023] [Indexed: 03/18/2023] Open
Abstract
Treatment of conifer stumps with a control agent effectively prevents Heterobasidion spore infections in summer cuttings and protects the residual stand and the next tree generation from damage caused by Heterobasidion root rot. Thus far, stump treatment experiments have been carried out in mineral soils, and no information is available on the efficacy of stump treatment agents in boreal peatland conditions. In the present study, biological and chemical control agents (Phlebiopsis gigantea and urea, respectively) were tested in Scots pine and Norway spruce stands subjected to thinning, cap cutting, and clearcutting on drained peatland in Central Finland. The control efficacy of urea was high in both spruce and pine stumps (on average 99.5 and 85.3%, respectively), while the efficacy of P. gigantea was highly variable on both tree species and ranged from full protection down to negative control effect, i.e., there were more Heterobasidion infections on the treated than untreated half of the stumps. The moisture content of the stump wood or the thickness of the peat layer did not affect the control efficacy of either control agent. These results emphasize a need for further studies to determine the reasons for the unsteadiness of the biological control in peatland conditions.
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Affiliation(s)
- Tuula Piri
- Natural Resources Institute Finland (Luke), Natural Resources, Forest Health and Biodiversity, Latokartanonkaari 9, 00790 Helsinki, Finland
- Correspondence:
| | - Markku Saarinen
- Natural Resources Institute Finland (Luke), Natural Resources, Forest Management, Tietotie 4, 31600 Jokioinen, Finland
| | - Leena Hamberg
- Natural Resources Institute Finland (Luke), Natural Resources, Forest Health and Biodiversity, Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Jarkko Hantula
- Natural Resources Institute Finland (Luke), Natural Resources, Forest Health and Biodiversity, Latokartanonkaari 9, 00790 Helsinki, Finland
| | - Talis Gaitnieks
- Latvian State Forest Research Insitute Silava, Forest Phytopathology and Mycology, 111 Riga Str., LV-2169 Salaspils, Latvia
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Mali T, Laine K, Hamberg L, Lundell T. Metabolic activities and ultrastructure imaging at late-stage of wood decomposition in interactive brown rot - white rot fungal combinations. FUNGAL ECOL 2023. [DOI: 10.1016/j.funeco.2022.101199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Korhonen A, Miettinen O, Kotze JD, Hamberg L. Landscape context and substrate characteristics shape fungal communities of dead spruce in urban and semi-natural forests. Environ Microbiol 2022; 24:3451-3462. [PMID: 35048489 PMCID: PMC9543266 DOI: 10.1111/1462-2920.15903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 01/12/2022] [Accepted: 01/12/2022] [Indexed: 12/03/2022]
Abstract
Urban green areas are becoming increasingly recognized for their biodiversity potential. However, little is known about how urbanization shapes cryptic species communities, such as those residing in deadwood. In this study, we investigated downed Norway spruce trunks at intermediate stages of decay, in urban and semi‐natural forests in southern Finland. To understand the interconnections between landscape context, deadwood characteristics and wood‐inhabiting fungal communities, we studied structural characteristics, surface epiphyte cover and internal moisture and temperature conditions of the tree trunks, and fungal communities residing in the wood. Our findings showed that urban tree trunks had less epiphyte cover and lower moisture than trunks in semi‐natural forests. Overall, urban forests provide less favourable habitats for a majority of the dominant wood‐inhabiting fungal species and for red‐listed species as a group. Yet, 33% of urban trunks hosted at least one red‐listed species. While these landscape‐scale effects may be driven by local climatic conditions as well as contingencies related to available species pools, our results also highlight the significance of substrate‐scale variability of deadwood in shaping wood‐inhabiting fungal communities. We show that epiphyte cover is a significant driver or indicator of these small‐scale dynamic processes in deadwood.
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Affiliation(s)
| | - Otto Miettinen
- Finnish Museum of Natural History, University of Helsinki
| | - Johan D Kotze
- Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki
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Müller MM, Hamberg L. Eradication of endophytes from needles, their inoculation with Lophodermium piceae and persistence of this fungus in needles of Norway spruce. Mycol Prog 2021. [DOI: 10.1007/s11557-021-01714-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AbstractLophodermium piceae is the most common endophyte of Norway spruce (Picea abies) needles, and it probably occurs in the total distribution area of Norway spruce. Its significance to the host tree is still largely unknown mainly because no methodology is known for generating endophyte-free saplings nor for inoculation of intact needles with this fungus. We report here how a daily heat treatment at 40 °C for 8 h eradicates endophytes of Norway spruce needles within a few days without causing visible harm to the plants. We compared various methods for inoculation of endophyte-free saplings. In order to obtain effective inocula, we investigated what factors activate dormant L. piceae infections in the needle tissue resulting in ascomata formation. Best inoculation success was achieved by suspending naturally shed, highly infected needles above the saplings. Infection frequencies of up to 70% of needles were achieved with repeated inoculations in the course of 3 years. Once established in needles, individual infections by L. piceae can persist for at least 5 years. Individual infections remain small in young needles, but at a needle age of 6 years, they start to grow and spread resulting in presence all over the needle from base to tip at a needle age of 7 years, but still without causing visible symptoms on the needles. The presented methodology for generating both endophyte-free and endophyte-infected saplings of Norway spruce provides a new approach for testing the significance of infections by L. piceae to insect herbivory and diseases of Norway spruce needles.
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Hamberg L, Poimala A, Velmala S, Perttunen J, Muilu-Mäkelä R, Sievänen R. Root discoloration and shoot symptoms in silver birch after Phytophthora infection in vitro. Plant Biol (Stuttg) 2021; 23:162-171. [PMID: 33073496 DOI: 10.1111/plb.13198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 10/02/2020] [Indexed: 06/11/2023]
Abstract
There are no records of established plant pathogenic Phytophthora species in Finnish forests, but they are likely in the future. Therefore, the effects of Phytophthora inoculations on young, ca. 2-month-old silver birch (Betula pendula) seedling roots and shoots were investigated. Visual inspection of dark discoloration, direct PCR and re-isolation, and detailed root morphology analyses were used to evaluate the effects of Phytophthora inoculation on roots. Symptoms in leaves and stems were also recorded. Phytophthora was successfully re-isolated from 67% of the surface-sterilized roots of inoculated seedlings, but not from the non-inoculated control seedlings. Dark discolorations were found more often in the root segments of inoculated seedlings than in control seedlings. In the Phytophthora-treated seedlings, discoloured root segments were usually linked and found primarily in the main root or lateral roots attached to it, whereas in the control seedlings a few single discoloured root segments were scattered throughout the root systems. The number of root segments was lower in the inoculated than in the control seedlings, indicating root loss after Phytophthora inoculation. In the shoots of inoculated birches, leaf and shoot wilting was observed. The appearance of wilting in shoots without visible dark discoloration in the base of stems indicated that symptoms originated from roots inoculated with Phytophthora.
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Affiliation(s)
- L Hamberg
- Natural Resources Institute Finland, Helsinki, Finland
| | - A Poimala
- Natural Resources Institute Finland, Helsinki, Finland
| | - S Velmala
- Natural Resources Institute Finland, Helsinki, Finland
| | - J Perttunen
- Natural Resources Institute Finland, Helsinki, Finland
| | - R Muilu-Mäkelä
- Natural Resources Institute Finland, Helsinki, Finland
- Natural Resources Institute Finland, Tampere, Finland
| | - R Sievänen
- Natural Resources Institute Finland, Helsinki, Finland
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Hamberg L, Saksa T, Hantula J. Role and function of Chondrostereum purpureum in biocontrol of trees. Appl Microbiol Biotechnol 2020; 105:431-440. [PMID: 33340337 PMCID: PMC7806553 DOI: 10.1007/s00253-020-11053-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/06/2020] [Accepted: 12/09/2020] [Indexed: 11/30/2022]
Abstract
Abstract A decay fungus, Chondrostereum purpureum (Pers. Ex Fr.) Pouzar, has been investigated in Europe, Northern America and New Zealand for its ability to decay hardwood stumps and thus prevent sprouting. The aim of these investigations has been to find an alternative to mechanical (cutting only) and chemical sprout control (cutting and applying chemicals to stumps in order to prevent sprouting). Mechanical sprout control is not an efficient option due to hardwood tree species’ ability to re-sprout efficiently after cutting, and therefore management costs are high. Chemicals would be efficient but due to their harmful effects on the environment, alternatives are needed. The fungal treatment, i.e., cutting accompanied with C. purpureum inoculum is an environmentally friendly and efficient option for sprout control. This mini-review comprises the role and function of C. purpureum in biocontrol of trees: the ecology of C. purpureum, its sprout control efficacy, factors affecting sprout control efficacy, devices in biological sprout control, potential risks, and the future perspectives of biological sprout control. Key points • A fungus Chondrostereum purpureum is efficient in preventing sprouting of hardwoods • C. purpureum is not sensitive to environmental conditions • Devices should be developed for cost-efficient biological sprout control
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Affiliation(s)
- Leena Hamberg
- Natural Resources Institute Finland, P.O. Box 2, (Latokartanonkaari 9), FI-00790, Helsinki, Finland.
| | - Timo Saksa
- Natural Resources Institute Finland, Juntintie 154, FI-77600, Suonenjoki, Finland
| | - Jarkko Hantula
- Natural Resources Institute Finland, P.O. Box 2, (Latokartanonkaari 9), FI-00790, Helsinki, Finland
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Hamberg L, Saarinen VM, Rantala M, Hantula J, Seiskari P, Saksa T. Rainstorm effects on the biocontrol efficacy of the decay fungus Chondrostereum purpureum against birch sprouting in boreal forests. Appl Microbiol Biotechnol 2020; 104:5107-5117. [PMID: 32242263 PMCID: PMC7228963 DOI: 10.1007/s00253-020-10574-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 03/02/2020] [Accepted: 03/22/2020] [Indexed: 11/04/2022]
Abstract
Abstract In forest regeneration areas, alongside roads and railways, under electric power lines and above gas pipe lines, there is a need for regular sprout control. A biocontrol method against broadleaved sprouting with formulations including the decay fungus Chondrostereum purpureum (Pers. Ex Fr.) Pouzar has been shown to be effective. Yet, heavy rain during spreading of this fungal inoculum on freshly cut stumps may affect the efficacy of the treatment, i.e., stump mortality during the following years. Thus, we performed an experiment where freshly cut birch stump surfaces (Betula pendula Roth and Betula pubescens Ehrh.) were treated with fungal inoculum under heavy irrigation and without it. Furthermore, two different adjuvants which aimed to fix the fungal inoculum to freshly cut stumps during irrigation and to protect against solar radiation were tested. Our results revealed that the artificial rainstorm treatment caused a delay in the efficacy of C. purpureum, but after three growing seasons, there was no significant difference in the mortality of birch stumps treated under irrigation or without it (stump mortalities 74 and 86%, respectively). Adjuvants did not improve the efficacy in stumps treated under irrigation nor in those treated without irrigation. Key Points • Heavy rain delayed the sprout control efficacy of a fungus Chondrostereum purpureum. • Final efficacy of formulations was the same in wet and dry conditions. • No additional adjuvants are needed to improve formulations.
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Affiliation(s)
- Leena Hamberg
- Natural Resources Institute Finland, Latokartanonkaari 9, FI-00790, Helsinki, Finland.
| | - Veli-Matti Saarinen
- Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600, Suonenjoki, Finland
| | - Markku Rantala
- Natural Resources Institute Finland, Latokartanonkaari 9, FI-00790, Helsinki, Finland
| | - Jarkko Hantula
- Natural Resources Institute Finland, Latokartanonkaari 9, FI-00790, Helsinki, Finland
| | - Pekka Seiskari
- Verdera Ltd, P.O. Box 5, Kurjenkellontie 5 B, FI-02270, Espoo, Finland
| | - Timo Saksa
- Natural Resources Institute Finland (Luke), Juntintie 154, FI-77600, Suonenjoki, Finland
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Pap N, Hamberg L, Pihlava JM, Hellström J, Mattila P, Eurola M, Pihlanto A. Impact of enzymatic hydrolysis on the nutrients, phytochemicals and sensory properties of oil hemp seed cake (Cannabis sativa L. FINOLA variety). Food Chem 2020; 320:126530. [PMID: 32222655 DOI: 10.1016/j.foodchem.2020.126530] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 02/27/2020] [Accepted: 02/28/2020] [Indexed: 12/22/2022]
Abstract
Enzymatic hydrolysis of the oil hemp seed (FINOLA variety) cake and defatted hemp seed cake by SC-CO2 was carried out using Flavorpro 750 MDP and Promod 439 L enzymes, and proximate composition, proanthocyanidins, phytic acid, lignanamides and cannabinoids were determined from the separated phases. CIELAB* color parameters were measured, while trained panelists evaluated taste, color, and smell in 1-9 Hedonic scale. Ten lignanamides, seven cannabisin-type and three grossamide-type, were found, from the cannabinoids, only cannabidiolic acid was detected. Protein, fat, ash, lignanamides and proanthocyanidins remained mostly in the sediments after the hydrolysis process in the Flavorpro treated samples, while dry matter, fat and ash was released mostly to liquids in Promod treated samples. The defatting process by SC-CO2 resulted in a higher lightness and the enzymatic processing did not have effect on the color attributes. Sediments from the enzymatic treatment were tastier, with better color and smell than liquids.
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Affiliation(s)
- Nora Pap
- Natural Resources Institute Finland, Production Systems, Myllytie 1, FIN-31600 Jokioinen, Finland.
| | - Leena Hamberg
- Natural Resources Institute Finland, Bioeconomy and Environment, Latokartanonkaari 9, FIN-00790 Helsinki, Finland.
| | - Juha-Matti Pihlava
- Natural Resources Institute Finland, Production Systems, Myllytie 1, FIN-31600 Jokioinen, Finland.
| | - Jarkko Hellström
- Natural Resources Institute Finland, Production Systems, Myllytie 1, FIN-31600 Jokioinen, Finland.
| | - Pirjo Mattila
- Natural Resources Institute Finland, Production Systems, Itäinen Pitkäkatu 4 A, FIN-20520 Turku, Finland.
| | - Merja Eurola
- Natural Resources Institute Finland, Natural Resources, Tietotie 4, FIN-31600 Jokioinen, Finland.
| | - Anne Pihlanto
- Natural Resources Institute Finland, Production Systems, Myllytie 1, FIN-31600 Jokioinen, Finland.
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Hamberg L, Velmala SM, Sievänen R, Kalliokoski T, Pennanen T. Early root growth and architecture of fast- and slow-growing Norway spruce (Picea abies) families differ-potential for functional adaptation. Tree Physiol 2018; 38:853-864. [PMID: 29253241 DOI: 10.1093/treephys/tpx159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 11/16/2017] [Indexed: 06/07/2023]
Abstract
The relationship between the growth rate of aboveground parts of trees and fine root development is largely unknown. We investigated the early root development of fast- and slow-growing Norway spruce (Picea abies (L.) H. Karst.) families at a developmental stage when the difference in size is not yet observed. Seedling root architecture data, describing root branching, were collected with the WinRHIZO™ image analysis system, and mixed models were used to determine possible differences between the two growth phenotypes. A new approach was used to investigate the spatial extent of root properties along the whole sample root from the base of 1-year-old seedlings to the most distal part of a root. The root architecture of seedlings representing fast-growing phenotypes showed ~30% higher numbers of root branches and tips, which resulted in larger root extensions and potentially a better ability to acquire nutrients. Seedlings of fast-growing phenotypes oriented and allocated root tips and biomass further away from the base of the seedling than those growing slowly, a possible advantage in nutrient-limited and heterogeneous boreal forest soils. We conclude that a higher long-term growth rate of the aboveground parts in Norway spruce may relate to greater allocation of resources to explorative roots that confers a competitive edge during early growth phases in forest ecosystems.
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Affiliation(s)
- Leena Hamberg
- Natural Resources Institute Finland (Luke), P.O. Box 2 (Latokartanonkaari 9), FI-00790 Helsinki, Finland
| | - Sannakajsa M Velmala
- Natural Resources Institute Finland (Luke), P.O. Box 2 (Latokartanonkaari 9), FI-00790 Helsinki, Finland
| | - Risto Sievänen
- Natural Resources Institute Finland (Luke), P.O. Box 2 (Latokartanonkaari 9), FI-00790 Helsinki, Finland
| | - Tuomo Kalliokoski
- Department of Physics, University of Helsinki, Atmospheric Sciences, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Taina Pennanen
- Natural Resources Institute Finland (Luke), P.O. Box 2 (Latokartanonkaari 9), FI-00790 Helsinki, Finland
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Vuosku J, Karppinen K, Muilu-Mäkelä R, Kusano T, Sagor GHM, Avia K, Alakärppä E, Kestilä J, Suokas M, Nickolov K, Hamberg L, Savolainen O, Häggman H, Sarjala T. Scots pine aminopropyltransferases shed new light on evolution of the polyamine biosynthesis pathway in seed plants. Ann Bot 2018; 121:1243-1256. [PMID: 29462244 PMCID: PMC5946884 DOI: 10.1093/aob/mcy012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 04/18/2018] [Indexed: 05/21/2023]
Abstract
Background and Aims Polyamines are small metabolites present in all living cells and play fundamental roles in numerous physiological events in plants. The aminopropyltransferases (APTs), spermidine synthase (SPDS), spermine synthase (SPMS) and thermospermine synthase (ACL5), are essential enzymes in the polyamine biosynthesis pathway. In angiosperms, SPMS has evolved from SPDS via gene duplication, whereas in gymnosperms APTs are mostly unexplored and no SPMS gene has been reported. The present study aimed to investigate the functional properties of the SPDS and ACL5 proteins of Scots pine (Pinus sylvestris L.) in order to elucidate the role and evolution of APTs in higher plants. Methods Germinating Scots pine seeds and seedlings were analysed for polyamines by high-performance liquid chromatography (HPLC) and the expression of PsSPDS and PsACL5 genes by in situ hybridization. Recombinant proteins of PsSPDS and PsACL5 were produced and investigated for functional properties. Also gene structures, promoter regions and phylogenetic relationships of PsSPDS and PsACL5 genes were analysed. Key Results Scots pine tissues were found to contain spermidine, spermine and thermospermine. PsSPDS enzyme catalysed synthesis of both spermidine and spermine. PsACL5 was found to produce thermospermine, and PsACL5 gene expression was localized in the developing procambium in embryos and tracheary elements in seedlings. Conclusions Contrary to previous views, our results demonstrate that SPMS activity is not a novel feature developed solely in the angiosperm lineage of seed plants but also exists as a secondary property in the Scots pine SPDS enzyme. The discovery of bifunctional SPDS from an evolutionarily old conifer reveals the missing link in the evolution of the polyamine biosynthesis pathway. The finding emphasizes the importance of pre-existing secondary functions in the evolution of new enzyme activities via gene duplication. Our results also associate PsACL5 with the development of vascular structures in Scots pine.
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Affiliation(s)
- Jaana Vuosku
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Katja Karppinen
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Riina Muilu-Mäkelä
- Natural Resources Institute Finland, Bio-based Business and Industry, Parkano, Finland
| | - Tomonobu Kusano
- Tohoku University, Graduate School of Life Sciences, Sendai, Miyagi, Japan
| | - G H M Sagor
- Tohoku University, Graduate School of Life Sciences, Sendai, Miyagi, Japan
| | - Komlan Avia
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
- UMI 3614 Evolutionary Biology and Ecology of Algae, CNRS, Sorbonne Universités, UPMC, Pontificia Universidad Católica de Chile, Universidad Austral de Chile, Station Biologique Roscoff, Roscoff, France
| | - Emmi Alakärppä
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Johanna Kestilä
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Marko Suokas
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Kaloian Nickolov
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Leena Hamberg
- Natural Resources Institute Finland, Management and Production of Renewable Resources, Vantaa, Finland
| | - Outi Savolainen
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Hely Häggman
- University of Oulu, Department of Ecology and Genetics, Oulu, Finland
| | - Tytti Sarjala
- Natural Resources Institute Finland, Bio-based Business and Industry, Parkano, Finland
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Hamberg L, de la Bastide P, Hintz W, Shamoun SF, Brandtberg M, Hantula J. Interfertility and genetic variability among European and North American isolates of the basidiomycete fungus Chondrostereum purpureum. Fungal Biol 2018; 122:659-667. [PMID: 29880201 DOI: 10.1016/j.funbio.2018.03.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 03/09/2018] [Accepted: 03/20/2018] [Indexed: 01/10/2023]
Abstract
The conspecificity of Finnish and western Canadian isolates of the decay fungus Chondrostereum purpureum was investigated by several approaches, including the assessment of genetic variability, mating and progeny analysis, and the analysis of selected phenotypic traits. Eight second-generation single spore strains per fungal isolate pairing were investigated with specific genetic markers developed for both Finnish and Canadian parental isolates. Tests of linkage disequilibrium were used to analyze whether these markers assorted independently among single spore strains. This procedure was similarly applied to the third-generation spore progeny. Finally, global non-metric multidimensional scaling was used to analyze independent random amplified microsatellite marker data to assess the genetic variability of the parental Finnish and Canadian isolates, and their second- and third-generation progeny. Our results revealed that the parental isolates from Finland and western Canada were genetically divergent, but no interfertility barriers were identified between these geographically distant fungi. Furthermore, parental genetic markers used in mating studies demonstrated that second- and third-generation spore progenies underwent normal meiosis and genetic recombination without linkage disequilibrium. Based on this work, the studied C. purpureum isolates from Finland and Canada can be considered as belonging to a single biological species, although genetic and limited phenotypic differentiation was observed.
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Affiliation(s)
- Leena Hamberg
- Natural Resources Institute Finland, P.O. Box 2 (Latokartanonkaari 9), FI-00790, Helsinki, Finland.
| | - Paul de la Bastide
- Department of Biology, Centre for Forest Biology, University of Victoria, P.O. Box 1700, STN CSC, Victoria, BC, V8W 2Y2, Canada.
| | - Will Hintz
- Department of Biology, Centre for Forest Biology, University of Victoria, P.O. Box 1700, STN CSC, Victoria, BC, V8W 2Y2, Canada.
| | - Simon Francis Shamoun
- Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, BC, V8Z 1M5, Canada.
| | - Marina Brandtberg
- Verdera Ltd., P.O. Box 5, Kurjenkellontie 5 B, FI-02270, Espoo, Finland.
| | - Jarkko Hantula
- Natural Resources Institute Finland, P.O. Box 2 (Latokartanonkaari 9), FI-00790, Helsinki, Finland.
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Hamidi M, Sullivan M, Hunter G, Hamberg L, Cho NL, Gawande AA, Doherty GM, Moore FD, Nehs MA. 4D-CT is Superior to Ultrasound and Sestamibi for Localizing Recurrent Parathyroid Disease. Ann Surg Oncol 2018; 25:1403-1409. [PMID: 29484563 DOI: 10.1245/s10434-018-6367-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Recurrent primary hyperparathyroidism (PHPT) presents a diagnostic challenge in localizing a hyperfunctioning gland. Although several imaging modalities are available for preoperative localization, 4D-CT is increasingly utilized for its ability to locate both smaller and previously unlocalized lesions. Currently, there is a paucity of data evaluating the utility of 4D-CT in the reoperative setting compared with ultrasound (US) and sestamibi. We aimed to determine the sensitivity of 4D-CT in localizing parathyroid adenomas in recurrent or persistent PHPT. METHODS We performed a retrospective review of prospectively collected data from a tertiary-care hospital, and identified 58 patients who received preoperative 4D-CT with US and/or sestamibi between May 2008 and March 2016. Data regarding the size, shape, and number of parathyroid lesions were collected for each patient. RESULTS A total of 62 lesions were identified intraoperatively among the 58 patients (6 with multigland disease) included in this investigation. 4D-CT missed 13 lesions identified intraoperatively, compared with 32 and 22 lesions missed by US and sestamibi, respectively. Sensitivity for correct lateralization of culprit lesions was 77.4% for 4D-CT, 38.5% for US, and 46% for sestamibi. 4D-CT was superior in lateralizing adenomas (49/62) compared with US (20/52; p < 0.001) and sestamibi (18/47; p < 0.001). The overall cure rate (6-month postoperative calcium < 10.7 mg/dL) was 89.7%. All patients with lesions correctly lateralized by 4D-CT were cured at 6 months. CONCLUSION 4D-CT localized parathyroid adenomas with higher sensitivity among patients with recurrent or persistent PHPT compared with sestamibi or US-based imaging.
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Affiliation(s)
- Moska Hamidi
- Division of General Surgery, London Health Sciences Center, London, ON, Canada
| | - Michael Sullivan
- Division of General Surgery, Jersey Shore University Medical Center, Neptune City, NJ, USA
| | - George Hunter
- Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Leena Hamberg
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Nancy L Cho
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Atul A Gawande
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Gerard M Doherty
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Francis D Moore
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Matthew A Nehs
- Department of Surgery, Brigham and Women's Hospital, Boston, MA, USA. .,General and Endocrine Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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13
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Ruan C, Sodickson A, Hamberg L. SU-G-IeP2-05: Effect of Localizer Type and Patient Off-Centering On CT Radiation Dose with Use of Automatic Tube Current Modulation. Med Phys 2016. [DOI: 10.1118/1.4957010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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14
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Hamberg L, Hantula J. The efficacy of six elite isolates of the fungus Chondrostereum purpureum against the sprouting of European aspen. J Environ Manage 2016; 171:217-224. [PMID: 26899306 DOI: 10.1016/j.jenvman.2016.02.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 02/04/2016] [Accepted: 02/08/2016] [Indexed: 06/05/2023]
Abstract
The sprouting of broad-leaved trees after cutting is problematic in forest regeneration areas, along roads and railways, under electric power and above gas pipe lines. In Finland, one of the most difficult species to control in these areas is the European aspen (Populus tremula), which produces both stump sprouts and root suckers after saplings have been cut. In this study, we investigated whether a decay fungus of broad-leaved trees, Chondrostereum purpureum, could be used as a biological control agent against aspen sprouting. The efficacy of six elite strains of C. purpureum (improved earlier in a breeding process) was investigated on aspen for three years. The most efficient C. purpureum strain, R53, tested earlier on birch (Betula pendula and B. pubescens), was efficient in causing mortality of aspen stumps and preventing the development of root suckers. With this strain, stump mortality was 78%, while significantly lower in control stumps which were cut only (47%). Aspen trees in the vicinity of the treatments (within a 10 m radius around each sapling) decreased the efficacy of C. purpureum. This study shows that the decay fungus C. purpureum can successfully be used in the sprout control of aspen saplings.
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Affiliation(s)
- Leena Hamberg
- Natural Resources Institute Finland (Luke), Jokiniemenkuja 1, FI-01301, Vantaa, Finland.
| | - Jarkko Hantula
- Natural Resources Institute Finland (Luke), Jokiniemenkuja 1, FI-01301, Vantaa, Finland.
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15
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Vuorinen I, Hamberg L, Müller M, Seiskari P, Pennanen T. Development of growth media for solid substrate propagation of ectomycorrhizal fungi for inoculation of Norway spruce (Picea abies) seedlings. Mycorrhiza 2015; 25:311-324. [PMID: 25348909 DOI: 10.1007/s00572-014-0611-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 10/07/2014] [Indexed: 06/04/2023]
Abstract
A silica-based propagation medium was developed for large-scale production of ectomycorrhizal (ECM) fungal inoculum by solid state fermentation. Development of the medium was started by screening for an optimal growth medium among six different semisynthetic agar media traditionally used in cultivation of ECM fungi. The majority (65 %) of the twenty tested ECM fungal strains that typically colonize Norway spruce (Picea abies) seedlings grew best on modified Melin-Norkrans (MMN) medium with reduced sugar content (½MMN). In order to develop a nutritionally similar medium for large-scale cultivation of the ECM fungi, we chose silica to form a solid matrix and light brewery malt extract to provide nutrients. The medium was supplemented with a commercial humic acid product that was shown to boost fungal growth. The optimal concentration of the constituents was screened for in two assays by determining the growth rates of seven potential inoculant ECM fungal strains (Amphinema sp., Cenococcum geophilum, Hebeloma sp., Meliniomyces bicolor, Paxillus involutus, Piloderma byssinum, and Tylospora asterophora). As a result, we composed a silica-based mass propagation medium (pH 5.8) containing 2.5 % brewery malt extract and 0.5 g/l humic acid product Lignohumate AM. This medium is easily produced and supported good growth of even the slowly growing and rarely studied Athelioid ECM strains. Furthermore, root systems of Norway spruce nursery seedlings were colonized by the tested ECM fungi by using solid inoculum formulated from the silica medium.
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Affiliation(s)
- Irmeli Vuorinen
- Finnish Forest Research Institute-Metla, Jokiniemenkuja 1, Box 18, 01301, Vantaa, Finland,
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16
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Hamberg L, Lehvävirta S, Kotze DJ, Heikkinen J. Tree species composition affects the abundance of rowan (Sorbus aucuparia L.) in urban forests in Finland. J Environ Manage 2015; 151:369-377. [PMID: 25588119 DOI: 10.1016/j.jenvman.2015.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 11/26/2014] [Accepted: 01/04/2015] [Indexed: 06/04/2023]
Abstract
Recent studies have shown a considerable increase in the abundance of rowan (Sorbus aucuparia) saplings in urban forests in Finland, yet the reasons for this increase are not well understood. Here we investigated whether canopy cover or tree species composition, i.e., the basal areas of different tree species in Norway spruce dominated urban forests, affects the abundances of rowan seedlings, saplings and trees. Altogether 24 urban forest patches were investigated. We sampled the number of rowan and other saplings, and calculated the basal areas of trees. We showed that rowan abundance was affected by tree species composition. The basal area of rowan trees (≥ 5 cm in diameter at breast height, dbh) decreased with increasing basal area of Norway spruce, while the cover of rowan seedlings increased with an increase in Norway spruce basal area. However, a decrease in the abundance of birch (Betula pendula) and an increase in the broad-leaved tree group (Acer platanoides, Alnus glutinosa, Alnus incana, Amelanchier spicata, Prunus padus, Quercus robur, Rhamnus frangula and Salix caprea) coincided with a decreasing number of rowans. Furthermore, rowan saplings were scarce in the vicinity of mature rowan trees. Although it seems that tree species composition has an effect on rowan, the relationship between rowan saplings and mature trees is complex, and therefore we conclude that regulating tree species composition is not an easy way to keep rowan thickets under control in urban forests in Finland.
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Affiliation(s)
- Leena Hamberg
- Finnish Forest Research Institute, P.O. Box 18, FI-01301, Vantaa, Finland.
| | - Susanna Lehvävirta
- Botanic Garden and Herbarium, Finnish Museum of Natural History, University of Helsinki, P.O. Box 44, FI-00014, Helsinki, Finland.
| | - D Johan Kotze
- Department of Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014, Helsinki, Finland.
| | - Juha Heikkinen
- Finnish Forest Research Institute, P.O. Box 18, FI-01301, Vantaa, Finland.
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17
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Hamberg L, Vartiamäki H, Hantula J. Breeding increases the efficacy of Chondrostereum purpureum in the sprout control of birch. PLoS One 2015; 10:e0117381. [PMID: 25674794 PMCID: PMC4326358 DOI: 10.1371/journal.pone.0117381] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/23/2014] [Indexed: 11/18/2022] Open
Abstract
We tested whether the pairing of selected isolates could be used to increase the efficiency of a decay fungus Chondrostereum purpureum (Pers. Ex Fr.) Pouzar to control hardwood sprouting in Finland. We paired C. purpureum strains efficient in sprout control or highly active in laccase production, and tested the efficacy of their progeny in spout control experiments. This procedure resulted in a strain with an efficacy superior to that of the parental strains. The mortality of birch (Betula pendula Roth. and B. pubescens Ehrh.) 1 cm in stump diameter was 78%, 56% and 9% for the best progeny, the best parental strain and the control, respectively. Mortality was only slightly higher for B. pendula than for B. pubescens but no significant differences were found between the number or maximum height of stump sprouts. Our results showed that cross breeding of this decay fungus is a good alternative in attempts to produce efficient biocontrol agents against hardwood sprouting.
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Affiliation(s)
- Leena Hamberg
- Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland
- * E-mail:
| | - Henna Vartiamäki
- Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland
| | - Jarkko Hantula
- Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland
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18
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Park M, Gerbaudo V, Hamberg L, Seaver K, Kijewski M. SU-D-9A-04: Brain PET/CT Imaging On a Scanner with a Large Axial Field-Of-View. Med Phys 2014. [DOI: 10.1118/1.4887920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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19
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Hyder R, Pennanen T, Hamberg L, Vainio EJ, Piri T, Hantula J. Two viruses of Heterobasidion confer beneficial, cryptic or detrimental effects to their hosts in different situations. FUNGAL ECOL 2013. [DOI: 10.1016/j.funeco.2013.05.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Tarvainen O, Hamberg L, Ohenoja E, Strömmer R, Markkola A. Responses of fungal and plant communities to partial humus removal in mid-boreal N-enriched forests. J Environ Manage 2012; 108:120-129. [PMID: 22705763 DOI: 10.1016/j.jenvman.2012.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 10/21/2011] [Accepted: 05/04/2012] [Indexed: 06/01/2023]
Abstract
Partial removal of the forest humus layer was performed in nitrogen-enriched urban Scots pine forest stands in the northern Finland in order to improve soil conditions for ectomycorrhizal (ECM) fungi, important symbionts of trees. Aboveground part of understory vegetation and the uppermost half of the humus layer were removed (REMOVAL treatment) from sample plots in six urban and eight rural reference forest sites at the beginning of the 2001 growing season. During the seasons 2001-2005, we inventoried sporocarp production of ECM and saprophytic fungi, and in 2003 the recovery of understory vegetation. The REMOVAL treatment resulted in a higher number of fruiting ECM species and sporocarps than controls at the rural, but not at urban sites. The sporocarp number of saprophytic fungi declined in the REMOVAL subplots at the urban sites. The recovery of bryophytes and lichens in the REMOVAL treatment was slow at both the urban and rural sites, whereas Vaccinium dwarf shrub cover, and herb and grass cover returned rapidly at the urban sites. We conclude that the partial vegetation and humus layer removal as a tool to promote the reproduction of ECM fungal species is limited in the boreal urban forests.
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Affiliation(s)
- Oili Tarvainen
- Finnish Forest Research Institute, Oulu Unit, BOX 413, FI 90014 University of Oulu Finland.
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21
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Heikkila J, Hamberg L, Meurman JH. Temporomandibular Disorders: Symptoms and Facial Pain in Orchestra Musicians in Finland. ACTA ACUST UNITED AC 2012. [DOI: 10.1177/1943862112445796] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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22
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Hamberg L, Malmivaara-Lämsä M, Lehvävirta S, O'Hara RB, Kotze DJ. Quantifying the effects of trampling and habitat edges on forest understory vegetation--a field experiment. J Environ Manage 2010; 91:1811-20. [PMID: 20434828 DOI: 10.1016/j.jenvman.2010.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 03/19/2010] [Accepted: 04/07/2010] [Indexed: 05/16/2023]
Abstract
We investigated the effects of human trampling on boreal forest understory vegetation on, and off paths from suburban forest edges towards the interiors and on the likelihood of trampling-aided dispersal into the forests for three years by carrying out a trampling experiment. We showed that the vegetation was highly sensitive to trampling. Even low levels of trampling considerably decreased covers of the most abundant species on the paths. Cover decreased between 10 and 30% on paths which had been trampled 35 times, and at least by 50% on those trampled 70-270 times. On-path vegetation cover decreased similarly at forest edges and in the interiors. However, some open habitat plant species that occurred outside the forest patches and at forest edges dispersed into the forests, possibly through the action of trampling. A higher cover percentage of an open habitat species at the forest edge line increased its probability to disperse into the forest interior. The vegetation community on, next to, and away from lightly trampled paths remained the same throughout the trampling experiment. For heavily trampled paths, the community changed drastically on the paths, but stayed relatively similar next to and away from the paths. As boreal vegetation is highly sensitive to the effects of trampling, overall ease of access throughout the forest floor should be restricted to avoid the excessive creation of spontaneous paths. To minimize the effects of trampling, recreational use could be guided to the maintained path network in heavily used areas.
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Affiliation(s)
- Leena Hamberg
- Finnish Forest Research Institute, P.O. Box 18, FI-01301 Vantaa, Finland.
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23
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Malmivaara-Lämsä M, Hamberg L, Löfström I, Vanha-Majamaa I, Niemelä J. Trampling tolerance of understorey vegetation in different hemiboreal urban forest site types in Finland. Urban Ecosyst 2008. [DOI: 10.1007/s11252-007-0046-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Sahani DV, Kalva SP, Hamberg L, Willett C, Saini S. Perfusion CT of Rectal Cancer: Assessing Tumor Vascularity (Angiogenesis) and Response to Radiotherapy - Initial Observations. Acad Radiol 2005. [DOI: 10.1016/j.acra.2005.03.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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25
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de Crespigny AJ, D'Arceuil HE, Maynard KI, He J, McAuliffe D, Norbash A, Sehgal PK, Hamberg L, Hunter G, Budzik RF, Putman CM, Gonzalez RG. Acute studies of a new primate model of reversible middle cerebral artery occlusion. J Stroke Cerebrovasc Dis 2005; 14:80-7. [PMID: 17904005 DOI: 10.1016/j.jstrokecerebrovasdis.2004.12.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Accepted: 12/06/2004] [Indexed: 11/29/2022] Open
Abstract
The recent failure of many clinical trials of neuroprotective compounds may be due in part to poor animal models of human stroke. We have developed an endovascular stroke model in nonhuman primates that is compatible with serial magnetic resonance imaging (MRI) monitoring. Using cynomologous macaques (n = 4), a microcatheter was navigated transarterially (under fluoroscopic guidance) from the femoral artery to the middle cerebral artery (MCA). The microcatheter was wedged in a branch of the MCA for 3 hours to cause focal cerebral ischemia, as verified angiographically. During occlusion and/or reperfusion, animals were scanned with MRI, and imaging findings were compared with the stained brain sections. All animals demonstrated small stroke lesions in the expected vascular territory, as seen on diffusion-weighted MRI and confirmed by postmortem examination. Reperfusion after 3 hours was confirmed angiographically (n = 2) and also by MRI (n = 4). The mean initial lesion volume, measured on the postreperfusion MRI scans, was 2.3 +/- 1.3 mL (n = 4). There was good agreement between anatomic location of the lesion on MRI and postmortem histological staining (n = 3). A "minimally invasive" primate model of focal cerebral ischemia was developed that is ideally suited to MRI studies of both acute and chronic stroke. By using serial MRI scans to measure changes in lesion size over time, we will be able to control for variability in lesion size/location. This model should prove useful as a test bed for new stroke therapies, in which noninvasive imaging findings are readily comparable to human stroke.
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Affiliation(s)
- Alex J de Crespigny
- Neuroradiology Section, Department of Radiology, Massachusetts General Hospital, Boston, MA, USA
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26
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Cullen SP, Symons SP, Hunter G, Hamberg L, Koroshetz W, González RG, Lev MH. Dynamic contrast-enhanced computed tomography of acute ischemic stroke: CTA and CTP. Semin Roentgenol 2002; 37:192-205. [PMID: 12226898 DOI: 10.1016/s0037-198x(02)80019-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Sean P Cullen
- Division of Neuroradiology, Stroke Service, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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27
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Schaefer PW, He J, Hunter G, Hamberg L, Gonzalez RG. Diffusion and Perfusion MRI in Predicting Final Infarct Volume: A Study of 81 Patients with Acute Stroke. Stroke 2001. [DOI: 10.1161/str.32.suppl_1.343-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
P25
Purpose:
To assess the utility of diffusion weighted imaging, cerebral blood volume, cerebral blood flow and mean transit time mapping in predicting final infarct volume in 81 patients with acute ischemic stroke.
Methods:
DWI, CBV, CBF and MTT images were obtained in 81 patients within 53 hours of stroke onset. Follow-up CT or T2 weighted MR images were obtained at 1 day to 4 months. Ischemic region volumes were measured on all images. An analysis of covariance with the variables of age, sex, treatment, time from stroke onset to imaging, and lesion type was performed. Linear regressions of DWI, CBV, CBF and MTT versus final infarct volume were obtained. A mismatch was determined if there was greater than 20% difference in volume between the diffusion and perfusion images.
Results:
Analysis of covariance demonstrated that DWI best predicts final infarct volume and that CBV alone of the other variables significantly improves the DWI prediction of final infarct volume. Linear regression analysis yielded an R
2
of 0.90, slope of 1.24 for DWI versus follow-up, R
2
of 0.84, slope of 1.22 for CBV versus follow-up, R
2
of 0.37, slope of 0.44 for CBF versus follow-up and R
2
of 0.25, slope of 0.33 for MTT versus follow-up. 13/81 patients had a DWI - CBV mismatch with mean lesion growth of 121 % while 68/81 patients had a DWI - CBV match with mean lesion growth of 15%. 36/81 had a DWI - CBF mismatch with mean lesion growth of 56% while 45/81 had a DWI - CBF match with mean lesion growth of 13%. 43/81 had a DWI - MTT mismatch with mean lesion growth of 47%. 38/81 had a DWI - MTT match with mean lesion growth of 16%.
Conclusions:
Both DWI and CBV are very good predictors of final infarct volume. CBF and MTT maps identify tissue at risk of infarction not identified on DWI or CBV maps. Since this tissue does not always infarct, these maps greatly overestimate final infarct size.The identification of a DWI - CBV, DWI - CBF or DWI - MTT mismatch predicts much more lesion growth compared with a diffusion perfusion match. This is most dramatic for DWI - CBV mismatches. This information may be valuable in the assessment of new therapeutic strategies.
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Affiliation(s)
| | - Julian He
- MA Gen Hosp, Boston, MA; MA Gen Hosp
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28
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Berzin TM, Lev MH, Goodman D, Koroshetz WJ, Hunter GJ, Hamberg L, Buonanno F, Putman C, Budzik R, Eskey C, Schwamm LH, Gonzalez RG. CT Perfusion Imaging versus MR Diffusion Weighted Imaging: Prediction of Final Infarct Size in Hyperacute Stroke. Stroke 2001. [DOI: 10.1161/str.32.suppl_1.317] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
10
Background:
Both CT perfusion imaging (CTP) and MR diffusion weighted imaging (DWI) have been applied clinically to predict tissue outcome in patients with hyperacute stroke, however these techniques have not been directly compared in the same patient population. In CTP, whole brain CT scanning is performed during the steady state administration of a contrast bolus, creating both perfused blood volume weighted and CT angiographic images. Purpose: To determine the value of CTP imaging, compared to DWI, in predicting final infarct size in hyperacute stroke patients. Materials and
Methods:
CTP followed by DWI imaging was performed in 23 consecutive patients presenting within 12 hours of stroke onset. Mean time from stroke onset to imaging was 4.6 hours for CTP, 5.4 hours for DWI, and 6.5 days for conventional nonenhanced CT and/or MR follow-up. No patients had secondary events between initial and follow-up scanning. Initial and follow-up ischemic volumes were computed from the CTP, DWI, and follow-up scans using image segmentation software, and compared using linear and multiple regression.
Results:
CTP and DWI volumes were independent predictors of final infarct size (p=0.02). The regression line for CTP volume vs. final infarct size had slope 1.02 and r
2
= 0.88 (p<0.0001). The regression line for DWI volume vs. final infarct size had slope 1.41 and r
2
= 0.92 (p<0.0001). Overall sensitivity and specificity for parenchymal stroke
detection
were 83% and 100% for CTP, and 100% and 100% for DWI, respectively.
Conclusion:
Although DWI is more sensitive than CTP for parenchymal stroke detection, both DWI and CTP are highly accurate predictors of final infarct volume. DWI tends to underestimate final infarct size, whereas CTP more closely approximates final infarct size.
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29
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Wolf GL, Gazelle GS, Hamberg L, Hunter G, Rogowska J, Jiang D, Leong F. Functional computed tomography scanning with radiopaque agents: applications in the brain, kidney, and tumor of small and large mammals. Acad Radiol 1996; 3 Suppl 2:S376-8. [PMID: 8796607 DOI: 10.1016/s1076-6332(96)80589-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- G L Wolf
- Center for Imaging & Pharmaceutical Research, Charlestown, MA 02129, USA
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30
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Abstract
Experimental studies of stroke in animal models have traditionally relied on histological endpoints for the measurement of neuroprotection. In this study, we used in vivo and dynamic MRI to quantify the neuroprotective effects of the non-competitive NMDA antagonist MK801. Four hours of occlusion followed by 6 h of reperfusion was performed in a rabbit model of focal cerebral ischemia. Spin-echo T2-weighted (T2W) MRI was used to quantify ischemic lesion volumes. Hemispheric measurements of perfusion deficits were assessed by using dynamic susceptibility-contrast MRI to map the first-pass transit of injected GdDTPA. Histological correlates of infarction were quantified using tetrazolium staining. Animals treated with 2 mg/kg MK801 infused immediately post-occlusion (n = 6) were compared with untreated controls (n = 8). T2W MRI scans obtained after 6 h of reperfusion showed high-intensity lesions in the ischemic basal ganglia and cortex. MK801-treated animals showed significantly decreased lesion volumes compared to untreated controls (7.3 +/- 3.2% treated vs 20.7 +/- 4.8% control, p < 0.05). Lesion volumes measured with MRI were significantly correlated with tetrazolium-defined infarct volumes (r = 0.766, p = 0.004). Dynamic MRI demonstrated the phenomenon of delayed hypoperfusion in the ischemic hemisphere during the late reperfusion phase; relative cerebral blood volume (rCBV) was 45.2 +/- 10.3% in untreated animals. MK801 slightly improved these deficits although the differences did not reach statistical significance (rCBV = 77.0 +/- 9.7%, p = 0.128).(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- Y Pan
- Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown 02129, USA
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31
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Brownell AL, Hantraye P, Wullner U, Hamberg L, Shoup T, Elmaleh DR, Frim DM, Madras BK, Brownell GL, Rosen BR. PET- and MRI-based assessment of glucose utilization, dopamine receptor binding, and hemodynamic changes after lesions to the caudate-putamen in primates. Exp Neurol 1994; 125:41-51. [PMID: 7905836 DOI: 10.1006/exnr.1994.1004] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In vivo physiological changes associated with striatal pathology were determined by measurement of glucose utilization, binding to D1 receptors and dopamine reuptake sites, regional blood flow, and behavior before and after unilateral quinolinate infusions into caudate-putamen in three nonhuman primates (Macaca fascicularis and Macaca mulatta). Following the quinolinate lesion, symptoms similar to those of Huntington's disease could be induced by dopamine agonist treatment. In addition, all animals showed a long-term decrease in glucose utilization in the caudate by [19F]fluoro-2-deoxy-D-glucose positron emission tomography (PET). At 4-6 weeks following the lesion the average decrease in glucose utilization in the caudate-putamen was between 40 and 50% of the prelesion values in primates with large lesions. Corresponding caudate-putamen regional blood volume in these animals showed a 61 and 74% decrease as studied by magnetic resonance imaging with somewhat smaller changes observed in an index of cerebral blood flow. The caudate-putamen uptake rate constants for D1 receptors reflected neuronal loss and decreased by an average 40 and 48%, as determined by 11C-labeled Schering compound (SCH 39 166) and PET. Dopamine reuptake sites and fibers assessed by the 11C-labeled cocaine analog, WIN 35 428 compound, and PET showed a temporary decrease in areas with mild neuronal loss and a long-term decrease in striatal regions with severe destruction. These results, which were consistent with behavioral changes and neuropathology seen at postmortem examination, can be related to in vivo physiological studies of Huntington's disease patients.
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Affiliation(s)
- A L Brownell
- Department of Radiology, Massachusetts General Hospital, Boston 02114
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Hamberg L, Aronen H. [Principles and study techniques of magnetic imaging]. Duodecim 1992; 108:713-24. [PMID: 1366285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Affiliation(s)
- L Hamberg
- Harvard Medical School, Massachusetts General Hospital, Charlestown 02129
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Bervenmark H, Hamberg L. Fluorine concentrations in deciduous human teeth after oral administration of sodium fluoride in vitamin solution. Acta Paediatr Scand 1974; 63:232-4. [PMID: 4820587 DOI: 10.1111/j.1651-2227.1974.tb04789.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Hamberg L. [On water fluoridation: voluntary mass prophylaxis with fluorine as a task for the child-welfare centers]. Lakartidningen 1970; 67:751-7. [PMID: 5421492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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