Ecological interactions in the transmission of the leishmaniases

Epidemiological studies on the leishmaniases are disclosing a multiplicity of Leishmania species infecting a wide range of wild mammalian hosts, from marsupials to monkeys. In the primitive, silvatic habitat these parasites are transmitted by an equally wide variety of phlebotomine sandfly species (Diptera: Psychodidae: Phlebotominae). Transmission is not haphazard, however, and available evidence points to the existence of environmental barriers that normally limit the different Leishmania species to specific sandfly vectors, transmitting to certain mammalian species, within distinct ecotopes. In this situation, humans may become infected by a variety of leishmanial parasites when intruding into the different enzootics, if the sandfly vectors are anthropophilic. Many are not, however, and their parasites rarely, if ever, make contact with the human host. Natural or man-made ecological changes may result in modification of the epidemiological pattern of leishmaniasis, leading to either a reduction or an increase in the human disease.

2021 ◽  
Vol 22 (9) ◽  
pp. 4617
Author(s):  
Styliana Kyriakoudi ◽  
Anthi Drousiotou ◽  
Petros P. Petrou

Mitochondria are dynamic organelles, the morphology of which is tightly linked to their functions. The interplay between the coordinated events of fusion and fission that are collectively described as mitochondrial dynamics regulates mitochondrial morphology and adjusts mitochondrial function. Over the last few years, accruing evidence established a connection between dysregulated mitochondrial dynamics and disease development and progression. Defects in key components of the machinery mediating mitochondrial fusion and fission have been linked to a wide range of pathological conditions, such as insulin resistance and obesity, neurodegenerative diseases and cancer. Here, we provide an update on the molecular mechanisms promoting mitochondrial fusion and fission in mammals and discuss the emerging association of disturbed mitochondrial dynamics with human disease.


2021 ◽  
Vol 9 (8) ◽  
pp. 1656
Author(s):  
Simona Gabrielli ◽  
Marialetizia Palomba ◽  
Federica Furzi ◽  
Emanuele Brianti ◽  
Gabriella Gaglio ◽  
...  

Blastocystis is a common intestinal protist distributed worldwide, infecting humans and a wide range of domestic and wild animals. It exhibits an extensive genetic diversity and, so far, 25 distinct small subunit ribosomal RNA (SSU rRNA) lineages termed subtypes (STs)) have been characterized; among them, 12 have thus far been reported in humans. The aims of the present study were to detect and genetically characterize Blastocystis sp. in synantropic animals to improve our current knowledge on the distribution and zoonotic transmission of Blastocystis STs in Italy. Samples were collected from N = 193 farmed animals and submitted to DNA extraction and PCR amplification of the SSU rRNA. Blastocystis was detected in 60 samples (31.08%) and successfully subtyped. Phylogenetic analysis evidenced that the isolates from fallow deer, goats, and pigs (N = 9) clustered within the ST5; those from pheasants (N = 2) in the ST6; those from chickens (N = 8) in the ST7; those from sheep (N = 6) in the ST10; and those from water buffaloes (N = 9) in the ST14 clade. The comparison between the present isolates from animals and those previously detected in humans in Italy suggested the animal-to-human spillover for ST6 and ST7. The present study represents the widest Blastocystis survey performed thus far in farmed animals in Italy. Further epidemiological studies using molecular approaches are required to determine the occurrence and distribution of Blastocystis STs in other potential animal reservoirs in Italy and to define the pathways of zoonotic transmission.


Author(s):  
Ying Pin Chua ◽  
Ying Xie ◽  
Poay Sian Sabrina Lee ◽  
Eng Sing Lee

Background: Multimorbidity presents a key challenge to healthcare systems globally. However, heterogeneity in the definition of multimorbidity and design of epidemiological studies results in difficulty in comparing multimorbidity studies. This scoping review aimed to describe multimorbidity prevalence in studies using large datasets and report the differences in multimorbidity definition and study design. Methods: We conducted a systematic search of MEDLINE, EMBASE, and CINAHL databases to identify large epidemiological studies on multimorbidity. We used the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews (PRISMA-ScR) protocol for reporting the results. Results: Twenty articles were identified. We found two key definitions of multimorbidity: at least two (MM2+) or at least three (MM3+) chronic conditions. The prevalence of multimorbidity MM2+ ranged from 15.3% to 93.1%, and 11.8% to 89.7% in MM3+. The number of chronic conditions used by the articles ranged from 15 to 147, which were organized into 21 body system categories. There were seventeen cross-sectional studies and three retrospective cohort studies, and four diagnosis coding systems were used. Conclusions: We found a wide range in reported prevalence, definition, and conduct of multimorbidity studies. Obtaining consensus in these areas will facilitate better understanding of the magnitude and epidemiology of multimorbidity.


2010 ◽  
Vol 23 (1) ◽  
pp. 4-22 ◽  
Author(s):  
Paul Guilloteau ◽  
Romuald Zabielski ◽  
Harald M. Hammon ◽  
Cornelia C. Metges

The consequences of early-life nutritional programming in man and other mammalian species have been studied chiefly at the metabolic level. Very few studies, if any, have been performed in the gastrointestinal tract (GIT) as the target organ, but extensive GIT studies are needed since the GIT plays a key role in nutrient supply and has an impact on functions of the entire organism. The possible deleterious effects of nutritional programming at the metabolic level were discovered following epidemiological studies in human subjects, and confirmed in animal models. Investigating the impact of programming on GIT structure and function would need appropriate animal models due to ethical restrictions in the use of human subjects. The aim of the present review is to discuss the use of pigs as an animal model as a compromise between ethically acceptable animal studies and the requirement of data which can be interpolated to the human situation. In nutritional programming studies, rodents are the most frequently used model for man, but GIT development and digestive function in rodents are considerably different from those in man. In that aspect, the pig GIT is much closer to the human than that of rodents. The swine species is closely comparable with man in many nutritional and digestive aspects, and thus provides ample opportunity to be used in investigations on the consequences of nutritional programming for the GIT. In particular, the ‘sow–piglets’ dyad could be a useful tool to simulate the ‘human mother–infant’ dyad in studies which examine short-, middle- and long-term effects and is suggested as the reference model.


2005 ◽  
Vol 48 (spe2) ◽  
pp. 145-152 ◽  
Author(s):  
David Wareham ◽  
J. Michael ◽  
Satya Das

Nuclear medicine is a powerful diagnostic technique able to detect inflammatory foci in human disease. A wide range of agents have been evaluated for their ability to distinguish lesions due to microbial infection from those due to sterile inflammation. Advances continue to be made on the use of radiolabelled antibiotics which as well as being highly specific in the diagnosis of infection may be useful in monitoring the treatment and course of disease. Here we provide an update on in-vitro and clinical studies with a number of established and novel radiopharmaceuticals


2021 ◽  
Vol 23 (11) ◽  
pp. 330-343
Author(s):  
Yogendra Shrestha ◽  
◽  
Jeet Bahadur Moktan ◽  
Renukaradhya Chitti ◽  
Shiv Kumar Yadav ◽  
...  

Background: Many variants detected after Wuhan-Hu-1 reference which were able to develop the resistance against the neutralizing antibodies induced by vaccine and may cause false negative results in diagnostic test. Novel variant B1.617 was detected in India and the Covid-19 cases hiked to its maximum; forcing the government towards approving a new vaccine for restricted use in emergency situation to cover a maximum population. Aims: This review looks at the efficacy, safety, and economical aspects of vaccines that have been authorized in India. Materials and methods: Wide-ranging assessment and analysis of accessible resources on online database. Results: The rAd26-s & rAd5-s demonstrate high efficacy as well as safety, followed by BBV152 and AZD1222. Various combinations of the vaccines with different platforms or vectors may induce wide range of immunity than a specific one. As per economical aspect, AZD1222 is more economical than the other two currently approved in India. Conclusion: There is a lack of clear end point to measure efficacy of the vaccine so the epidemiological studies with huge number of populations is required which may predict the perfect endpoint for efficacy measurement. Until then, inoculation with locally accessible vaccines and self-awareness about disease transmission prevention are the main options for reducing fatalities, protecting the health-care system, and eventually disease control.


Author(s):  
H Klus ◽  
M Kunze ◽  
S Koenig ◽  
E Poeschl

AbstractSmoking, especially cigarette smoking, is the most common form of tobacco consumption world-wide. It is generally accepted that smoking carries health risks for smokers. The combustion and pyrolysis products of tobacco generated during smoking are considered to be responsible for the harmful effects. Smokeless tobacco, another wide-spread form of tobacco use, is not subjected to burning and produces no combustion or pyrolysis products. Therefore, there is an increasingly intense debate about the potential role of smokeless tobacco in reducing the harm of tobacco use.An overview is presented on the different types of smokeless tobaccos consumed around the world. Commercial products differ widely in composition and patterns of use. The smokeless tobaccos of the Western world (Europe and North America) need to be clearly distinguished from those popular in Asia, Africa and South America. The modern smokeless tobaccos used in Europe and North America are reviewed regarding their chemical composition and toxicological properties. Agents of concern found in smokeless tobacco, especially the tobacco specific N-nitrosamines, are dealt with in particular.The epidemiological evidence is summarized concerning a wide range of health outcomes. Published reviews and studies are presented and interpreted regarding non-neoplastic oral diseases, various forms of cancer, circulatory diseases, several other diseases and pregnancy outcome. While many of the epidemiological studies have weaknesses and data are often inconsistent it is quite obvious that smokeless tobacco use is much less risky for consumers than smoking. In fact, for modern forms of European moist snuff such as Swedish snus, which is subject to strict quality standards, there is evidence for - if any - only very limited serious health risk.The ongoing public discussion centers around the influence smokeless tobacco may have on smoking rates (initiation or cessation) and the occurrence of tobacco specific diseases - with Sweden being a revealing example. There is an interesting controversy regarding product and marketing regulations for smokeless tobaccos in the European Union.


2021 ◽  
Vol 288 (1944) ◽  
pp. 20202716
Author(s):  
Steve Kett ◽  
Ayush Pathak ◽  
Stefano Turillazzi ◽  
Duccio Cavalieri ◽  
Massimiliano Marvasi

Arthropods can produce a wide range of antifungal compounds, including specialist proteins, cuticular products, venoms and haemolymphs. In spite of this, many arthropod taxa, particularly eusocial insects, make use of additional antifungal compounds derived from their mutualistic association with microbes. Because multiple taxa have evolved such mutualisms, it must be assumed that, under certain ecological circumstances, natural selection has favoured them over those relying upon endogenous antifungal compound production. Further, such associations have been shown to persist versus specific pathogenic fungal antagonists for more than 50 million years, suggesting that compounds employed have retained efficacy in spite of the pathogens' capacity to develop resistance. We provide a brief overview of antifungal compounds in the arthropods’ armoury, proposing a conceptual model to suggest why their use remains so successful. Fundamental concepts embedded within such a model may suggest strategies by which to reduce the rise of antifungal resistance within the clinical milieu.


2018 ◽  
Vol 46 (5) ◽  
pp. 1213-1224 ◽  
Author(s):  
Jessica L. Barnes ◽  
Maria Zubair ◽  
Kaarthik John ◽  
Miriam C. Poirier ◽  
Francis L. Martin

Humans are variously and continuously exposed to a wide range of different DNA-damaging agents, some of which are classed as carcinogens. DNA damage can arise from exposure to exogenous agents, but damage from endogenous processes is probably far more prevalent. That said, epidemiological studies of migrant populations from regions of low cancer risk to high cancer risk countries point to a role for environmental and/or lifestyle factors playing a pivotal part in cancer aetiology. One might reasonably surmise from this that carcinogens found in our environment or diet are culpable. Exposure to carcinogens is associated with various forms of DNA damage such as single-stand breaks, double-strand breaks, covalently bound chemical DNA adducts, oxidative-induced lesions and DNA–DNA or DNA–protein cross-links. This review predominantly concentrates on DNA damage induced by the following carcinogens: polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, mycotoxins, ultraviolet light, ionising radiation, aristolochic acid, nitrosamines and particulate matter. Additionally, we allude to some of the cancer types where there is molecular epidemiological evidence that these agents are aetiological risk factors. The complex role that carcinogens play in the pathophysiology of cancer development remains obscure, but DNA damage remains pivotal to this process.


Author(s):  
P.F. Stevens

Linnaeus was educated in Sweden, and became a doctor of medicine in Harderwijk, Holland, in 1735. He visited other European countries then, but he never left Sweden after his return in 1738. After practising as a physician in Stockholm, he moved to Uppsala University as professor of medicine and botany in 1741. He articulated four different but complementary ways of understanding nature – through two kinds of classification, and through what can be called developmental and functional/ecological interactions. Linnaeus is best known for his classificatory work, for which he received material from all over the world. His classificatory precepts are elaborated in the Philosophia botanica of 1751, an enlarged version of the 365 aphorisms of his Fundamenta botanica of 1735; the other aspects of his work are diffused through his writings. His artificial classification system, initially very popular, was replaced by the ’natural’ system, more slowly in botany than in zoology, and more slowly in England than in some other countries. Current biological nomenclature is based on his Species plantarum, edition 1 (for plants), and Systema naturae, edition 10 (for animals). His codification of botanical terms remains influential. Almost 200 dissertations, most written by Linnaeus, were defended by his students. In these and other less well-known works, including the unpublished Nemesis divina (Stories of Divine Retribution), he covered a wide range of subjects. Quinarian thinking is noticeable in Linnaeus’ work – there are five ranks in systems, five years’ growth in flowers – and in some of the occult works that he knew. He also shows a strong combinatorial bent and a tendency to draw close analogies between the parts of animals and plants.


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