1,431 research outputs found
Comparative clinico-haematological analysis in young Zebu cattle experimentally infected with Trypanosoma vivax isolates from tsetse infested and non-tsetse infested areas of Northwest Ethiopia
Background:
Ethiopia, particularly in the Northwest region, is affected by both tsetse and non-tsetse fly transmitted trypanosomosis, with significant impact on livestock productivity. The aim of this study was to determine and compare clinical findings and haematological values between experimental infections induced by Trypanosoma vivax isolates from areas of either transmission mode. Sixteen young (aged between 6 and 12 months) Zebu cattle (Bos indicus), purchased from a trypanosome-free area and confirmed to be trypanosome-negative, were randomly assigned into four groups of four animals. Groups 1, 2 and 3 were infected with an isolate from a tsetse infested or one of two isolates from a non-tsetse infested area, and group 4 was a non-infected control. All animals in the infected groups were inoculated intravenously with 2 × 106 trypanosomes from donor animals. The experimental animals were monitored for eight consecutive weeks post infection for clinical signs, parasitaemia and haematological changes in packed cell volume (PCV), haemoglobin concentration (Hgb), total red blood cell (RBC) and white blood cell (WBC) counts, differential WBC count and blood indices (mean corpuscular volume [MCV], mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration).<p></p>
Results:
Infection was characterized by reduced feed intake, weakness, pyrexia, parasitaemia, rough hair coat, enlarged prescapular lymph nodes, lacrimation, weight loss, pallor mucus membrane and dehydration. Body weight loss in all infected groups was significantly higher than in the non-infected control. Similarly, body weight loss was higher (P < 0.001) in animals infected with the tsetse infested isolate than with the non-tsetse infested isolates. The mean PCV, Hgb, total RBC and WBC counts were lower (P < 0.001), and mean MCV was higher (P = 0.01) in all infected groups than in non-infected control animals at different time points during the study period. Except for minor variations in haematological values, the overall changes were similar in all infected groups.<p></p>
Conclusion:
Clinical signs and significant reduction in haematological values in the infected groups indicated the pathogenicity of the T. vivax parasites. Pathogenicity of T. vivax from the non-tsetse infested area can be considered as nearly as important as that of its counterpart derived from the tsetse infested area
Magnitude of Out of Pocket Health Expenditures and Associated Factors Among Civil Servants
In Ethiopia, as other developing countries, public health care is provided at nominally low prices and free to those that does not afford to pay. But the health care consumer population is still to make considerable amount of out-of-pocket health expenditure for various reasons. A cross sectional quantitative study from January to May 2013 was done. Study population was civil servants in Debre Markos town. A total of 467 study participants were selected by using simple random sampling method. Data were collected by trained high school graduates and then the collected data were entered into a computer by using Epi-Data version 3.1 and analysis was performed by using SPSS version 16 for windows. Possible associations between out of pocket health expenditure and its predictors were analyzed by using both bivariate and multivariate analysis. The mean age of the study participants were 41 years. Majorities were between 25 and 44 years of age, 258 (55.2%). The level of education among the study participants indicated that most 380 (81.4%) were graduates of higher education (HE) and majority were Orthodox Christian which accounted 446 (95.5%) followed by Muslims 13 (2.8%). To put it briefly, the study identified that the median of out of pocket health care expenditure accounted 8.26% of total household income. Health status of the household (with or without chronic illness), debt on any of the household, house on construction owned by any household member, educational fee for at least one member of the household and predominantly used health institution were the associated factors that have significant impact on household out of pocket health expenditure. There is economic burden as a result of health care at household level. Based on the results, the recommendation was introducing social health insurance for all civil servant employees in the study area
Markov Chain Modeling of Daily Rainfall in Lay Gaint Woreda, South Gonder Zone, Ethiopia
Information on seasonal Kiremet and seasonal Belg rainfall amount is important in the rain fed agriculture of Ethiopia since more than 85% of the population is dependent on agriculture particularly on rain fed farming practices. The distribution pattern of rainfall rather than the total amount of rainfall within the entire period of time is more important for studying the pattern of rainfall occurrence. A two-state Markov chain was used to describe the characteristics of rainfall occurrences in this woreda. The states, as considered were; dry (d) and rainy (r). The overall chance of rain and the fitted curve tells us that the chance of getting rain in the main rainy season is about twice as compared to the small rainy season. The first order Markov chain model indicates that the probability of getting rain in the small rainy season is significantly dependent on whether the earlier date was dry or wet. While the second order Marko chain indicates that the main rainy season the dependence of the probability of rain on the previous two dates\u27 conditions is less as compared with the small rainy season. Rainfall amounts are very variable and are usually modeled by a gamma distribution. Therefore, the pattern of rainfall is somewhat unimodial having only one extreme value in August. Onset, cessation and length of growing season of rainfall for the main rainy season show medium variation compared to the small rainy season
p38 MAP kinase mediated proteoglycan synthesis as a target for the prevention of atherosclerosis
The major underlying pathology of most cardiovascular disease is the chronic inflammatory disease of atherosclerosis. Type 2 diabetes, also recognised as an inflammatory condition, accelerates the development of atherosclerosis. Current therapies for atherosclerosis target risk factors such as elevated blood lipids and hypertension and are of strong but limited efficacy. The "response to retention" hypothesis states that atherosclerosis is initiated by the accumulation of lipids through binding to extracellular matrix, and this is specifically the glycosaminoglycan (GAG) chains on proteoglycans. Many vasoactive agonists stimulate changes in the structure of the GAGs which increase lipid binding and the relevant signalling pathways are a potential therapeutic target. It has recently been demonstrated that the actions of transforming growth factor b; on vascular smooth muscle proteoglycan synthesis involves signalling through p38 MAP kinase and inhibition of this pathway reduces binding of lipids. Inhibition of p38 MAP kinase will elicit a wide spread antiinflammatory response which may alleviate some of the deleterious processes in cardiovascular tissues. This article explores the potential for the actions of p38 MAP kinase inhibitors directed at proteoglycan synthesis in vascular smooth muscle to contribute to the beneficial outcomes from targeting p38 MAP kinase for the prevention of cardiovascular disease
Smad2-dependent glycosaminoglycan elongation in aortic valve interstitial cells enhances binding of LDL to proteoglycans
Calcific aortic valve disease is a progressive condition that shares some common pathogenic features with atherosclerosis. Transforming growth factor-ß1 is a recognized mediator of atherosclerosis and is expressed in aortic valve lesions. Transforming growth factor-ß1 stimulates glycosaminoglycan elongation of proteoglycans that is associated with increased lipid binding. We investigated the presence of transforming growth factor-ß1 and downstream signaling intermediates in diseased human aortic valves and the effects of activated transforming growth factor-ß1 receptor signaling on aortic valve interstitial cell proteoglycan synthesis and lipid binding as a possible mechanism for the initiation of the early lesion of calcific aortic valve disease
CFD Simulation and Optimization of Very Low Head Axial Flow Turbine Runner
The main objective of this work is Computational Fluid Dynamics (CFD) modelling, simulation and optimization of very low head axial flow turbine runner to be used to drive a centrifugal pump of turbine-driven pump. The ultimate goal of the optimization is to produce a power of 1kW at head less than 1m from flowing river to drive centrifugal pump using mechanical coupling (speed multiplier gear) directly. Flow rate, blade numbers, turbine rotational speed, inlet angle are parameters used in CFD modeling, simulation and design optimization of the turbine runner. The computed results show that power developed by a turbine runner increases with increasing flow rate. Pressure inside the turbine runner increases with flow rate but, runner efficiency increases for some flow rate and almost constant thereafter. Efficiency and power developed by a runner drops quickly if turbine speed increases due to higher pressure losses and conversion of pressure energy to kinetic energy inside the runner. Increasing blade number increases power developed but, efficiency does not increase always. Efficiency increases for some blade number and drops down due to the fact that change in direction of the relative flow vector at the runner exit, which decreases the net rotational momentum and increases the axial flow velocity
TGF-β stimulates biglycan core protein synthesis but not glycosaminoglycan chain elongation via Akt phosphorylation in vascular smooth muscle
Transforming growth factor-b (TGF-b) can mediate proteoglycan synthesis via Smad and non-Smad signalling pathways in vascular smooth muscle (VSM). We investigated whether TGF-b-mediated proteoglycan synthesis is via PI3K/Akt. TGF-b induced a rapid phosphorylation of Akt that continued upto 4 h. Akt phosphorylation was blocked by Akt1/2 inhibitor SN30978; however, it did not block Smad2 phosphorylation at either the carboxy or linker regions indicating that TGF-bmediated Akt phosphorylation is independent of Smad2 signalling. The role of Akt in TGF-b-mediated proteoglycan synthesis was investigated. Treatment with SN30978 showed a concentration-dependent decrease in TGF-b-mediated [35S]- sulphate and [35S]-Met/Cys incorporation into secreted proteoglycans; however, SDS-PAGE showed no change in biglycan size. In TGF-b-treated cells, biglycan mRNA levels increased by 40-100% in 24 h and was significantly blocked by SN30978. Our findings demonstrate that Akt is a downstream signalling component of TGF-b-mediated biglycan core protein synthesis but not glycosaminoglycan chain hyper-elongation in VSM
A dynamic model of transmission and elimination of peste des petits ruminants in Ethiopia
Peste des petits ruminants (PPR), a devastating viral disease of sheep and goats, has been targeted by the global community for eradication within the next 15 years. Although an efficacious attenuated live vaccine is available, the lack of knowledge about the transmission potential of PPR virus (PPRV) may compromise eradication efforts. By fitting a metapopulation model simulating PPRV spread to the results of a nationwide serological survey in Ethiopia, we estimated the level of viral transmission in an endemic setting and the vaccination coverage required for elimination. Results suggest that the pastoral production system as a whole acts as a viral reservoir, from which PPRV spills over into the sedentary production system, where viral persistence is uncertain. Estimated levels of PPRV transmission indicate that viral spread could be prevented if the proportion of immune small ruminants is kept permanently above 37% in at least 71% of pastoral village populations. However, due to the high turnover of these populations, maintaining the fraction of immune animals above this threshold would require high vaccine coverage within villages, and vaccination campaigns to be conducted annually. Adapting vaccination strategies to the specific characteristics of the local epidemiological context and small ruminant population dynamics would result in optimized allocation of limited resources and increase the likelihood of PPR eradication
Influence of the biotope on the tick infestation of cattle and on the tick-borne pathogen repertoire of cattle ticks in Ethiopia
Background:
The majority of vector-borne infections occur in the tropics, including Africa, but molecular eco-
epidemiological studies are seldom reported from these regions. In particular, most previously published data on ticks in
Ethiopia focus on species distribution, and only a few molecular studies on the occurrence of tick-borne pathogens or on
ecological factors influencing these. The present study was undertaken to evaluate, if ticks collected from cattle in different
Ethiopian biotopes harbour (had access to) different pathogens.
Methods:
In South-Western Ethiopia 1032 hard ticks were removed from cattle grazing in three kinds of tick biotopes. DNA
was individually extracted from one specimen of both sexes of each tick species per cattle. These samples were molecularly
analysed for the presence of tick-borne pathogens.
Results:
Amblyomma variegatum
was significantly more abundant on mid highland, than on moist highland.
Rhipicephalus
decoloratus
was absent from savannah lowland, where virtually only
A. cohaerens
was found. In the ticks
Coxiella burnetii
had
the highest prevalence on savannah lowland. PCR positivity to
Theileria
spp. did not appear to depend on the biotope, but
some genotypes were unique to certain tick species. Significantly more
A. variegatum
specimens were rickettsia-positive,
than those of other tick species. The presence of rickettsiae (
R. africae
) appeared to be associated with mid highland in case
of
A. variegatum
and
A. cohaerens
. The low level of haemoplasma positivity seemed to be equally distributed among the tick
species, but was restricted to one biotope type.
Conclusions:
The tick biotope, in which cattle are grazed, will influence not only the tick burden of these hosts, but also the
spectrum of pathogens in their ticks. Thus, the presence of pathogens with alternative (non-tick-borne) transmission routes,
with transstadial or with transovarial transmission by ticks appeared to be associated with the biotope type, with the tick
species, or both, respectively
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