1,665 research outputs found
Dicoumarol toxicity in neonatal calves associated with the feeding of sweet vernal (Anthoxanthum odoratum) hay
No full textNeonatal calves from a seasonal dairy herd in North Western Tasmania were presented for veterinary care due to mortalities and bleeding from multiple orifices. Necropsy examination revealed free blood throughout the parenchymatous organs, body cavities and connective tissues. There was no history of anticoagulant exposure, however, high quantities of dicoumarol were found in samples from hay fed to recently calved cows. No Australian cases of dicoumarol toxicity in neonatal calves have been previously documented, and dicoumarol toxicity in adult cattle would appear to be less common than in colder farming regions of the Northern Hemisphere.LR: 20061115; PUBM: Print; JID: 0370616; 66-76-2 (Dicumarol); CIN: Aust Vet J. 2003 Aug;81(8):479. PMID: 15086083; ppublishSource type: Electronic(1
The aetiology and pathogenesis of tropical ulcer
Get PDFTropical ulcer is a very specific form of cutaneous ulceration. It occurs worldwide in most tropical and a number of subtropical areas. The disease occurs mainly in older children and young adults with children under the age of 5 and adults over 45 years rarely being affected. Ulcers occur most commonly on the lower leg but may occur on the upper limb. Although most ulcers normally heal slowly over many weeks or months, some ulcers may recur. Recognised complications include squamous cell carcinoma, gangrene and osteitis, although these are rare. A number of authors have reported on the disease and suggested diet, trauma and infection as aetiological factors for this condition. This survey was thus conducted to assess as many of these factors as possible. The study took place in 5 tropical areas, namely Zambia, Gambia, southern India, Fiji and Papua New Guinea. Consultations took place at hospitals, rural clinics, health centres and villages. Although many authors have suggested that the disease is related to malnutrition, few have objectively assessed the nutritional status of the patients and compared it with controls. Those studies which included objective assessments were limited to small areas and only investigated specific parameters. In order to investigate the immune response of the host to an anaerobic infection, the antibody levels to the organisms isolated from the ulcers were measured by an ELISA test. The local host response to an infection with a Fusobacterium species was assessed by the number of antibody secreting B-lymphocytes at the site of the ulcers. These parameters may play a role in the localisation of the ulcers and account for recurrent infections
lugar donde hay muchas casas
No full textLa información de esta miniguía se basa en los trabajos publicados de Raúl Flores Guerrero, J. Ferrando Roig, R. Perry, M.A. Vázquez Benítez y Manuel ToussaintCalpan significa "lugar donde hay muchas casas", según la etimología náhuatl. Antes de la llegada de los europeos al nuevo mundo, ésta era una pequeña localidad independiente, pero muy ligada al poderío Huejotzinca, y al igual que ellos, participaban en las guerras floridas para capturar guerreros que eran sacrificados en ceremonias religiosas.
La conquista pone a los calpeños en relación semejante con sus vecinos, su población es diezmada por las epidemias pero, al igual que los tlaxcaltecas, apoyan a los españoles con mano de obra para la construcción de la ciudad de Puebla.
En 1548 Fray Juan de Alameda edifica el monasterio de San Andrés Calpan, uno de los conventos franciscanos mejor conservado del siglo XVI
The distortionary effects of tariff exemptions in Argentina
Get PDFTariff exemptions for exporters are widely used by many countries as aninstrument for providing export incentives. This author argues that when tariff exemptions are granted as a means of industrial regional promotion to an industry independently of its export performance, the tariff exemptions lose their potential as an export promotion instrument. The case of Argentina is of interest because it exemplifies the practice of many developing countries. A simple model is used to show that the indiscriminate use of duty exemptions has several undesirable effects : 1) duty exemptions deprive the government of revenues; 2) the more widespread the exemption, the less effective they become as an instrument for export promotion; 3) exemptions widen the variability of effective protection rates of industries in relation to their capital intensity; and 4) exemptions increase the demand for imports more than an export subsidy does, because output in the competing input industry contracts.Environmental Economics&Policies,TF054105-DONOR FUNDED OPERATION ADMINISTRATION FEE INCOME AND EXPENSE ACCOUNT,Economic Theory&Research,Consumption,Export Competitiveness
Exposure to indoor microbial agents, allergens and pets, and their relation to asthma and allergy prevalence in farmers' children and their peers from rural areas : Diploma thesis
Get PDFBackground In ‘westernised’ countries, the prevalence of childhood asthma and allergy have risen throughout the last three decades. Changes in lifestyle and environmental factors like an increase in exposure to air pollutants, environmental tobacco smoke, or indoor allergen and pet exposure have been considered as plausible explanations. However, little evidence in support of these causal risk factors for these common chronic childhood diseases has been found. Lower risk of hay fever and atopic sensitisation were reported in children with more siblings, and later also in children who attended day care centres early in infancy. These findings were summarised in the so-called ‘hygiene hypothesis’: limited exposure to bacterial and viral pathogens during early childhood results in a higher risk of developing allergic diseases. Recent allergy research has focused on the interaction between the innate and adaptive immunity: innate immunity receptors of pathogens seem to modulate the activation of adaptive immunity mechanisms. Three independent studies showed reduced prevalence of asthma and allergy among farmers’ children compared to their peers from the same rural areas from Switzerland, Austria, and Germany. A series of epidemiological studies in Europe, Canada, and Australia consistently confirmed and extended these findings. These results have been seen as an extension of the ‘hygiene hypothesis’, since a farm environment provides an enormous habitat for micro-organisms. A potential candidate that may explain these differences in the prevalence of childhood asthma and allergy is environmental exposure to endotoxin, a component of the outer membrane of gram-negative bacteria. Aim To assess the exposure to indoor microbial agents, allergens and pets in farmers’ children and their peers of non-farming families, and to estimate whether these exposures are associated with the prevalence of childhood asthma and allergies. Methods The ALEX (Allergy and Endotoxin) study was a cross-sectional survey in rural areas of Germany, Austria, and Switzerland. 2618 parents of 6-13 year-old children completed a standardised questionnaire including questions about asthma and allergy from the ISAAC study
and questions about the child’s activities on farms, and characteristics of the home environment.
Blood samples were obtained from selected children and tested for atopic sensitisation,
specially for specific IgE and IgG4 antibodies to grass pollen and cat allergen. Endotoxin and
cat allergen levels were measured in indoor dust samples and in settled dust from stables.
Complete data were available for 812 children. In a subgroup of 553 children mattress dust
muramic acid levels, another marker for exposure to bacteria, were determined.
Results
Higher levels of indoor endotoxin exposure were associated with reduced allergen sensitisation,
decreased prevalence of hay fever, atopic asthma and wheeze in a dose-dependent
manner. The associations were equally strong among the sub sample children from nonfarming
families, indicating that even lower levels of endotoxin may favourably influence the
risk of atopic diseases.
Endotoxin levels in stables were not correlated with the amount of endotoxin measured
indoors, but a dose-dependent association between the child’s activity on the farm and indoor
home endotoxin levels was observed, both in farmers’ and in non-farmers’ children. Pet keeping,
full time farming (compared to part time farming), and younger age of the children contributed
additionally to increased indoor endotoxin levels. Endotoxin levels in stables increased
with the number of cattle (but only up to the highest quartile), with hay feeding (compared
to feeding of mainly silage), and additionally with provision of accommodation of
horses, pigs, sheep or goats in the cattle stable. All these predictors might be surrogate measures
for traditional dairy farming in hilly German speaking areas.
Children’s mattress’ muramic acid levels were significantly higher in farmers’ children
than in non-farmers’ children. Mattress muramic acid and endotoxin levels were partially correlated,
indicating that both substances are markers for the exposure to micro-organisms. Independent
of being a farmers’ child, mattress dust from homes heated with wood or coal and
less frequently cleaned mattresses showed increasing muramic acid levels.
Independent of the endotoxin exposure, increasing muramic acid levels in mattress dust
was associated with a lower frequency of current wheeze, but not with atopic sensitisation or
hay fever. The protective effect on wheeze and diagnosed asthma was more pronounced in
non-sensitised children. The different effect spectrum for muramic acid and endotoxin exposure
suggest that different micro-organisms might contribute to the lower prevalence of
asthma and allergy among farmers’ children, compared to non-farmers’ children.
Current contact to dogs was inversely associated with diagnosed hay fever, asthma, and
specific sensitisation to grass pollen and to cat allergen, but not with increased IgG4 levels.
Early and current exposure to cats – but not to dogs – was associated with lower frequency of
wheeze and grass pollen sensitisation. None of these inverse associations were greatly affected
by additionally taking into account the indoor endotoxin or cat allergen levels, but additionally
adjustment for early or current exposure to farm animals attenuated the protective
effects. Although pet exposure was frequent in this rural population, the protective effects of
pet keeping observed in other peer-reviewed studies may be masked by frequent contact to
farming environments.
Conclusions and outlook
Endotoxin and muramic acid may be surrogate markers of a much broader spectrum of
microbial compounds. Thus, further studies have not only to confirm the lower risk of children
with contact to livestock or with higher exposure to micro-organisms early in life, but
also to find the relevant mixture of protective components in the farm dust. In addition, as
ingestion is another plausible route of exposure to micro-organisms, epidemiology may focus
on differences in nutrition and their association with childhood asthma and allergy. The PARSIFAL
(Prevention of allergy – Risk factors for sensitisation in children related to farming
and anthroposophic lifestyle) study offers the opportunity to do so, as this study include children’s
populations growing up with different lifestyles. Experimental studies may focus on
the relevant exposure route (inhalation, ingestion) of different patterns of micro-organisms.
The genetic dimension has to be kept in mind in the discussion of environmental exposure to
micro-organisms by identifying particularly sensitive groups through genetic investigations,
as the available data in the ALEX study was limited.
Current scientific evidence has not developed strongly enough to provide a reliable
course of action for primary prevention or therapy. Infectious diseases resulting from exposure
to pathogens continue to be a serious public health problem. Thus, the protective effect
of a microbial environment on the development of asthma and atopy should be balanced
against the benefits of established hygiene standards
Human population, urban settlement patterns and their impact on Plasmodium falciparum malaria endemicity
Get PDFBackground: the efficient allocation of financial resources for malaria control and the optimal distribution of appropriate interventions require accurate information on the geographic distribution of malaria risk and of the human populations it affects. Low population densities in rural areas and high population densities in urban areas can influence malaria transmission substantially. Here, the Malaria Atlas Project (MAP) global database of Plasmodium falciparum parasite rate (PfPR) surveys, medical intelligence and contemporary population surfaces are utilized to explore these relationships and other issues involved in combining malaria risk maps with those of human population distribution in order to define populations at risk more accurately.Methods: first, an existing population surface was examined to determine if it was sufficiently detailed to be used reliably as a mask to identify areas of very low and very high population density as malaria free regions. Second, the potential of international travel and health guidelines (ITHGs) for identifying malaria free cities was examined. Third, the differences in PfPR values between surveys conducted in author-defined rural and urban areas were examined. Fourth, the ability of various global urban extent maps to reliably discriminate these author-based classifications of urban and rural in the PfPR database was investigated. Finally, the urban map that most accurately replicated the author-based classifications was analysed to examine the effects of urban classifications on PfPR values across the entire MAP database.Results: masks of zero population density excluded many non-zero PfPR surveys, indicating that the population surface was not detailed enough to define areas of zero transmission resulting from low population densities. In contrast, the ITHGs enabled the identification and mapping of 53 malaria free urban areas within endemic countries. Comparison of PfPR survey results showed significant differences between author-defined 'urban' and 'rural' designations in Africa, but not for the remainder of the malaria endemic world. The Global Rural Urban Mapping Project (GRUMP) urban extent mask proved most accurate for mapping these author-defined rural and urban locations, and further sub-divisions of urban extents into urban and peri-urban classes enabled the effects of high population densities on malaria transmission to be mapped and quantified.Conclusion: the availability of detailed, contemporary census and urban extent data for the construction of coherent and accurate global spatial population databases is often poor. These known sources of uncertainty in population surfaces and urban maps have the potential to be incorporated into future malaria burden estimates. Currently, insufficient spatial information exists globally to identify areas accurately where population density is low enough to impact upon transmission. Medical intelligence does however exist to reliably identify malaria free cities. Moreover, in Africa, urban areas that have a significant effect on malaria transmission can be mappe
Skin-Related Neglected Tropical Diseases (Skin NTDs)—A New Challenge
Get PDFMedical teaching has emphasised over many years the uniqueness of disease states, valuing the rare skills on which the art of diagnosis is based and the intricacies of individual patient-centred management. [...
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