Occurrence of fungal diseases of Coffea arabica L. in montane rainforests of Ethiopia

Coffee Berry Disease (CBD), Colletotrichum kahawae, Coffee Wilt Disease (CWD), Gibberella xylarioides and Coffee Leaf Rust (CLR), Hemileia vastatrix are the three major diseases reducing production and consumption of coffee in Ethiopia. A survey was conducted from July to September 2005 for CBD and CWD and from 2003 until 2007 for CLR in montane rainforest coffee areas of Ethiopia to estimate the occurrence and distribution of these diseases. Diseases were prevalent in all the surveyed forest coffee areas of Ethiopia: Harenna, Bonga, Berhane-Kontir and Yayu. Depending on the forest coffee area the mean percent incidence of CBD ranged from 2 to 40 % in general and from 2 to 17.9 % at Berhane-Kontir and Bonga, respectively. The mean incidence of CWD varied from 2.4 % at Berhane-Kontir to 16.9 % at Yayu forest coffee areas. The mean incidence of CLR also varied for instance in 2005 from 32.2 % at Berhane-Kontir to 96 % at Harenna forest coffee areas. The detection of the diseases during our surveys requires an integrated management of major coffee diseases for a sustainable conservation and wise use of coffee in montane rainforests of Ethiopia

Use of Integrated SPECT/CT Imaging for Tumor Dosimetry in I-131 Radioimmunotherapy: A Pilot Patient Study

Abstract Integrated systems combining functional (single-photon emission computed tomography; SPECT) imaging with anatomic (computed tomography; CT) imaging have the potential to greatly improve the accuracy of dose estimation in radionuclide therapy. In this article, we present the methodology for highly patient-specific tumor dosimetry by utilizing such a system and apply it to a pilot study of 4 follicular lymphoma patients treated with I-131 tositumomab. SPECT quantification included three-dimensional ordered-subset expectation-maximization reconstruction and CT-defined tumor outlines at each time point. SPECT/CT images from multiple time points were coupled to a Monte Carlo algorithm to calculate a mean tumor dose that incorporated measured changes in tumor volume. The tumor shrinkage, defined as the difference between volumes drawn on the first and last CT scan (a typical time period of 15 days) was in the range 5%-49%. The therapy-delivered mean tumor-absorbed dose was in the range 146-334cGy. For comparison, the therapy dose was also calculated by assuming a static volume from the initial CT and was found to underestimate this dose by up to 47%. The agreement between tracer-predicted and therapy-delivered tumor-absorbed dose was in the range 7%-21%. In summary, malignant lymphomas can have dramatic tumor regression within days of treatment, and advanced imaging methods allow for a highly patient-specific tumor-dosimetry calculation that accounts for this regression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78152/1/cbr.2008.0568.pd

Bone marrow adipose tissue is a unique adipose subtype with distinct roles in glucose homeostasis

Bone marrow adipose tissue (BMAT) comprises >10% of total adipose mass, yet unlike white or brown adipose tissues (WAT or BAT) its metabolic functions remain unclear. Herein, we address this critical gap in knowledge. Our transcriptomic analyses revealed that BMAT is distinct from WAT and BAT, with altered glucose metabolism and decreased insulin responsiveness. We therefore tested these functions in mice and humans using positron emission tomography-computed tomography (PET/CT) with 18F-fluorodeoxyglucose. This revealed that BMAT resists insulin- and cold-stimulated glucose uptake, while further in vivo studies showed that, compared to WAT, BMAT resists insulin-stimulated Akt phosphorylation. Thus, BMAT is functionally distinct from WAT and BAT. However, in humans basal glucose uptake in BMAT is greater than in axial bones or subcutaneous WAT and can be greater than that in skeletal muscle, underscoring the potential of BMAT to influence systemic glucose homeostasis. These PET/CT studies characterise BMAT function in vivo, establish new methods for BMAT analysis, and identify BMAT as a distinct, major adipose tissue subtype

Towards a collaborative research: A case study on linking science to farmers' perceptions and knowledge on Arabica coffee pests and diseases and its management

The scientific community has recognized the importance of integrating farmer's perceptions and knowledge (FPK) for the development of sustainable pest and disease management strategies. However, the knowledge gap between indigenous and scientific knowledge still contributes to misidentification of plant health constraints and poor adoption of management solutions. This is particularly the case in the context of smallholder farming in developing countries. In this paper, we present a case study on coffee production in Uganda, a sector depending mostly on smallholder farming facing a simultaneous and increasing number of socio-ecological pressures. The objectives of this study were (i) to examine and relate FPK on Arabica Coffee Pests and Diseases (CPaD) to altitude and the vegetation structure of the production systems; (ii) to contrast results with perceptions from experts and (iii) to compare results with field observations, in order to identify constraints for improving the information flow between scientists and farmers. Data were acquired by means of interviews and workshops. One hundred and fifty farmer households managing coffee either at sun exposure, under shade trees or inter-cropped with bananas and spread across an altitudinal gradient were selected. Field sampling of the two most important CPaD was conducted on a subset of 34 plots. The study revealed the following findings: (i) Perceptions on CPaD with respect to their distribution across altitudes and perceived impact are partially concordant among farmers, experts and field observations (ii) There are discrepancies among farmers and experts regarding management practices and the development of CPaD issues of the previous years. (iii) Field observations comparing CPaD in different altitudes and production systems indicate ambiguity of the role of shade trees. According to the locality-specific variability in CPaD pressure as well as in FPK, the importance of developing spatially variable and relevant CPaD control practices is proposed. (Résumé d'auteur

Mating Test and In Vitro Production of Perithecia by the Coffee Wilt Pathogen , Gibberella xylarioides (Fusarium xylarioides)

Gibberella xylarioides Heim & Saccas, the teleomorphic state of Fusarium xylarioides Steyaert, is a fungal pathogen causing a vascular wilt disease of coffee known as tracheomycosis. Coffee wilt disease has been one of the endemic diseases of Arabica coffee (Coffea arabica) with increasing outbreaks and prevalence in Ethiopia. In the present study, in vitro production of fertile perithecia was assessed by crossing eight randomly selected monoconidial isolates of G. xylarioides (F. xylarioides) collected from C. arabica, including few strains from C. canephora and C. excelsa. Five media types and two temperature levels were compared for inducing the sexual structures in the fungus. In vivo development of perithecia on coffee trees in the field and on inoculated young seedlings in the greenhouse was also examined. More than 30% of the crosses formed perithecia in vitro including those pairings of isolates recovered from the different Coffea spp. Isolate Gx1 (BBA 71975) showed high intra- and inter-fertility with most of the strains indicating that this isolate was most probably ‘female fertile' mating type. This interfertility was successfully achieved only on carrot agar and V-8 juice medium at 20oC and 12-hr photoperiod 10 – 12 wks after plating. The fungus often produced abundant perithecia containing enormous ascospores in the barks of dead coffee trees in the field and in the artificially infected young seedlings. The in vitro and in vivo perithecial developments were most likely favoured by cool and moist (wet) conditions. Abundant production of ascospores in the field is an integral part of survival and dispersal mechanisms along with genetic exchange system. The in vitro formation of fertile perithecia enables to study inheritance of traits such as pathogenicity (virulence) and gene flow and genetic diversity in populations of G. xylarioides. Keywords: Coffee wilt disease; Coffea arabica; Ethiopia; Gibberella xylarioides; Mating test; Perithecia Ethiopian Journal of Biological Sciences Vol. 6 (1) 2007: pp. 63-7

Clinical dosimetry in the treatment of bone tumors: old and new agents

Treatment of multisite, sclerotic bone metastases is successfully performed by radionuclide therapy. Pain palliation is the most common aim for the treatment. Two radiopharmaceuticals are currently approved by the European Medicines Agency (Sm-153-EDTMP and Sr-89-Cl-2) whilst other radiopharmaceuticals are at different stages of development, or are approved in some European countries (Re-186-HEDP, Sn-117(m)-DTPA and Ra-223-Cl-2). The tissues at risk for the treatment are bone marrow and normal bone. A review of the methods applied for dosimetry for these tissues and for tumours is performed, including the calculation of S values (the absorbed dose per decay) and optimal procedures on how to obtain biodistribution data for each radiopharmaceutical. The dosimetry data can be used to individualise and further improve the treatment for each patient. Dosimetry for radionuclide therapy of bone metastases is feasible and can be performed in a routine clinical practice

Single-cell dosimetry for radioimmunotherapy of B-cell lymphoma patients with special reference to leukemic spread

Aims: Many lymphoma patients have both macroscopic tumors and single-cell manifestations of their disease. Treatment efficacy could, therefore, depend on the radionuclide used. The aim of this study was to investigate dosimetry at a cellular level for three isotopes of radioiodine. Methods: Cells were assumed to be spherical with radii of 6.35, 7.7, and 9.05 mu m corresponding to the dimensions of the Raji cells. The radius of the nucleus was assumed to be 75% of the cellular radius. The electron energies were 18, 28, and 190 keV, corresponding to the mean electron energy per decay for I-125, I-123, and I-131, respectively. S-values for different activity distributions were simulated using Monte Carlo and dose-volume histograms as well as absorbed doses, and absorbed dose rates were calculated. Results: I-125 gives the highest absorbed dose (similar to 4-40 times that of I-131), whereas I-123 Will give the highest absorbed dose rate (similar to 100 times that of I-131). Under the given assumptions, the absorbed dose at this level is more dependent on the Size of the cells than on whether the radioimmunoconjugate is internalized. Conclusions: This enquiry showed that both I-123 and I-125 have greater potential than I-131 for the treatment of leukemic spread in patients With lymphoma