Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
MedComm Oncol ; 3(2)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38831791

RESUMO

Infectious etiologies have previously been proposed as causes of both melanoma and non-melanoma skin cancer. This exploratory overview explains and presents the evidence for the hypothesis that a microorganism excreted in infected ruminant animal feces, Mycobacterium avium subspecies paratuberculosis (MAP), is the cause of some cases of cutaneous melanoma (CM). Occupational, residential, and recreational contact with MAP-contaminated feces, soil, sand, and natural bodies of water may confer a higher rate of CM. Included in our hypothesis are possible reasons for the differing rates and locations of CM in persons with white versus nonwhite skin, why CM develops underneath nails and in vulvar skin, why canine melanoma is an excellent model for human melanoma, and why the Bacille Calmette-Guérin (BCG) vaccine has demonstrated efficacy in the prevention and treatment of CM. The pathogenic mechanisms and etiologic aspects of MAP, as a transmittable agent underlying CM risk, are carefully deliberated in this paper. Imbalances in gut and skin bacteria, genetic risk factors, and vaccine prevention/therapy are also discussed, while acknowledging that the evidence for a causal association between MAP exposure and CM remains circumstantial.

2.
Transl Cancer Res ; 12(2): 398-412, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36915598

RESUMO

Background and Objective: Animal microorganisms have been proposed as a cause of human cancers associated with farming, agricultural occupation or residence, and related downstream exposures. Several studies have described uveal melanoma (UvM) as a farming-associated cancer. A possible suspect is the animal microorganism Mycobacterium avium subspecies paratuberculosis (MAP), the causative agent of paratuberculosis in dairy cows. This microbe is transmitted to humans through various means, including contact with animal faeces, contaminated dust and soil, organic fertilizers, and as workers in slaughterhouses/animal processing facilities. The objective of the current manuscript was to examine the putative association between Mycobacterium avium sub-species paratuberculosis and non-solar UvM. Methods: Online data sources (PubMed, Scopus, Cochrane Library, and Google) published in English between 1980 to present were searched for key words pertaining to MAP exposure, farming-related occupations and activities, and locations with or in the vicinity of dairy cattle. Key Content and Findings: While higher than expected rates of eye cancer have been suggested among dairy farmers, with MAP being ubiquitous in their environment, the involvement of MAP in the aetiology of non-solar UvMs (which account for ~97% of UvM cases) remains uncertain. Conclusions: Alternative explanations exist and future cause-and-effect research is needed to answer this hypothesis. A precautionary approach to exposure continues to be a prudent strategy.

3.
Artigo em Inglês | MEDLINE | ID: mdl-35913017

RESUMO

Several infections have been associated with motor neuron diseases resembling ALS, including species of viruses, bacteria, and parasites. Mycobacterium avium subspecies paratuberculosis (MAP), most known for its probable etiologic association with Crohn's disease, has been suggested as another possible infectious cause of motor neuron disease. Two published case reports describe the successful treatment of ALS-like symptoms with antimycobacterial antibiotics. Both cases had atypical features. Based on these, we believe it would be reasonable to begin performing chest imaging in PALS who have features of their history or exam that are atypical for ALS such as pain, fevers, or eye movement abnormalities. If the chest imaging is abnormal, more specific testing for mycobacteria may be indicated. Until there is more clear evidence of an association between mycobacteria and ALS, we cannot endorse the widespread use of potentially toxic antimycobacterial antibiotics for PALS.


Assuntos
Esclerose Lateral Amiotrófica , Doença de Crohn , Doença dos Neurônios Motores , Mycobacterium avium subsp. paratuberculosis , Animais , Humanos , Antibacterianos/uso terapêutico , Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/complicações , Doença de Crohn/etiologia , Doença de Crohn/microbiologia , Doença dos Neurônios Motores/complicações
4.
Open Vet J ; 9(1): 5-12, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-31086759

RESUMO

An increased rate of diffuse gliomas, including glioblastoma, has been noted in livestock farmers in Western countries. Some researchers have suggested that a zoonotic virus or bacteria present in the livestock animal's feces or manure may be a possible etiologic factor. Mycobacterium avium subspecies paratuberculosis (MAP), the cause of a chronic enteropathy in domestic livestock and a probable zoonosis, is heavily excreted in an infected animal's feces or manure, contaminating soil and ground on the animal's farm. Once excreted in an animal's feces, MAP lasts indefinitely in a dormant but viable form, and easily spreads outside farms to the surrounding environment. MAP's presence throughout the soil in countries where MAP infection of domestic livestock is extensive and long-standing may explain the increased rates of glioblastoma in tennis and baseball players who handle balls coated with MAP-contaminated dirt. MAP infection is consistent with glioblastoma's two defining histopathologic characteristics: endothelial cell proliferation and pseudopalisading necrosis. MAP is a non-tuberculous or atypical mycobacterium, which can cause hypoxic necrotizing granulomas, granulomas that resemble areas of pseudopalisading necrosis. There are known bacterial causes of endothelial cell proliferation. Almost unique amongst intracellular bacteria, MAP's variant isocitrate dehydrogenase 1 (IDH1) enzyme, a type 2-oxoglutarate ferredoxin oxidoreductase, can use a host cell's cytosolic α-ketoglutarate in its own Krebs or tricarboxylic acid cycle. MAP's ability to use a host cell's α-ketoglutarate may explain the survival advantage of the cytosolic IDH1 enzyme mutation for patients with diffuse gliomas including glioblastoma, astrocytoma, and oligdendroglioma, a mutation that results in a reduced supply of cytosolic α-ketoglutarate. MAP may therefore be one possible infectious cause of glioblastoma and the other histologic categories of diffuse glioma.


Assuntos
Glioblastoma/veterinária , Glioma/veterinária , Mycobacterium avium subsp. paratuberculosis/fisiologia , Paratuberculose/epidemiologia , Animais , Glioblastoma/epidemiologia , Glioblastoma/metabolismo , Glioblastoma/patologia , Glioma/epidemiologia , Glioma/metabolismo , Glioma/patologia , Humanos , Paratuberculose/metabolismo , Paratuberculose/microbiologia , Paratuberculose/patologia
5.
Med Hypotheses ; 119: 1-5, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30122477

RESUMO

There are several suspected infectious causes of amyotrophic lateral sclerosis (ALS) or motor neurone disease including HIV-1 and species of Brucella, Cyanobacteria and Schistosoma. The increased rates and clusters of ALS in amateur and professional outdoor sports players including rugby, football and soccer players suggest a microorganism present in the grass, dirt and dust they play on and in may be a causative factor. The probable zoonosis Mycobacterium avium subspecies paratuberculosis (MAP) is heavily excreted in an infected domestic ruminant's feces or manure and is extensively distributed throughout the soil in countries where MAP infection of domestic livestock is longstanding. Like other zoonotic pathogens, MAP can be transmitted to humans by inhalation of aerosolized pathogen-contaminated soil, by direct contact of pathogen-contaminated grass, dirt and dust with mucus membranes lining the nose or mouth or through abrasions and cuts in the skin. Outdoor sports players may develop ALS after multiple oral, nasal or subcutaneous doses of MAP present in the dirt, dust and grass of their playing fields.


Assuntos
Esclerose Lateral Amiotrófica/etiologia , Esclerose Lateral Amiotrófica/microbiologia , Atletas , Mycobacterium avium subsp. paratuberculosis , Animais , Poeira , Exposição Ambiental , Fezes , Futebol Americano , Humanos , Esterco , Poaceae , Futebol , Solo
6.
Infect Agent Cancer ; 13: 1, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29308085

RESUMO

Infectious agents are known causes of human cancers. Schistosoma japonicum and Schistosoma mansoni cause a percentage of colorectal cancers in countries where the respective Schistosoma species are prevalent. Colorectal cancer is a complication of ulcerative colitis and colonic Crohn's disease, the two main forms of idiopathic inflammatory bowel disease (IIBD). Mycobacterium avium subspecies paratuberculosis (MAP), the cause of a chronic intestinal disease in domestic and wild ruminants, is one suspected cause of IIBD. MAP may therefore be involved in the pathogenesis of IIBD-associated colorectal cancer as well as colorectal cancer in individuals without IIBD (sporadic colorectal cancer) in countries where MAP infection of domestic livestock is prevalent and MAP's presence in soil and water is extensive. MAP organisms have been identified in the intestines of patients with sporadic colorectal cancer and IIBD when high magnification, oil immersion light microscopy (×1000 total magnification rather than the usual ×400 total magnification) is used. Research has demonstrated MAP's ability to invade intestinal goblet cells and cause acute and chronic goblet cell hyperplasia. Goblet cell hyperplasia is the little-recognized initial pathologic lesion of sporadic colorectal cancer, referred to as transitional mucosa, aberrant crypt foci, goblet cell hyperplastic polyps or transitional polyps. It is the even lesser-recognized initial pathologic feature of IIBD, referred to as hypermucinous mucosa, hyperplastic-like mucosal change, serrated epithelial changes, flat serrated changes, goblet cell rich mucosa or epithelial hyperplasia. Goblet cell hyperplasia is the precursor lesion of adenomas and dysplasia in the classical colorectal cancer pathway, of sessile serrated adenomas and serrated dysplasia in the serrated colorectal cancer pathway, and of flat and elevated dysplasia and dysplasia-associated lesions or masses in IIBD-associated intestinal cancers. MAP's invasion of intestinal goblet cells may result in the initial pathologic lesion of IIBD and sporadic colorectal cancer. MAP's persistence in infected intestines may result in the eventual development of both IIBD-associated and sporadic colorectal cancer.

7.
Virulence ; 3(6): 546-50, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23076274

RESUMO

Nine individuals with ulcerative colitis or Crohn disease grew up or lived in Plains, Montana, a 1,200-person community adjacent to the Clark Fork River near herds of free ranging Rocky Mountain bighorn sheep. This inflammatory bowel disease outbreak is similar to others that have occurred along rivers contaminated by animal feces.


Assuntos
Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Surtos de Doenças , Carneiro da Montanha/microbiologia , Adolescente , Adulto , Animais , Animais Selvagens , Criança , Fezes/microbiologia , Humanos , Pessoa de Meia-Idade , Montana/epidemiologia , Mycobacterium avium subsp. paratuberculosis , Rios , Poluição da Água , Adulto Jovem
8.
Gut Pathog ; 3(1): 20, 2011 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-22196128

RESUMO

We report an ongoing outbreak of ulcerative colitis and Crohn's disease in Forest, Virginia involving 15 unrelated children and teenagers who resided in close proximity to dairy farms. Some of our cases demonstrated serologic evidence of Mycobacterium avium subspecies paratuberculosis infection, suggesting its potential role as an etiologic agent.

9.
Gut Pathog ; 2(1): 21, 2010 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-21167058

RESUMO

Mycobacterium avium, subspecies paratuberculosis (MAP) causes a chronic disease of the intestines in dairy cows and a wide range of other animals, including nonhuman primates, called Johne's ("Yo-knee's") disease. MAP has been consistently identified by a variety of techniques in humans with Crohn's disease. The research investigating the presence of MAP in patients with Crohn's disease has often identified MAP in the "negative" ulcerative colitis controls as well, suggesting that ulcerative colitis is also caused by MAP. Like other infectious diseases, dose, route of infection, age, sex and genes influence whether an individual infected with MAP develops ulcerative colitis or Crohn's disease. The apparently opposite role of smoking, increasing the risk of Crohn's disease while decreasing the risk of ulcerative colitis, is explained by a more careful review of the literature that reveals smoking causes an increase in both diseases but switches the phenotype from ulcerative colitis to Crohn's disease. MAP as the sole etiologic agent of both ulcerative colitis and Crohn's disease explains their common epidemiology, geographic distribution and familial and sporadic clusters, providing a unified hypothesis for the prevention and cure of the no longer "idiopathic" inflammatory bowel diseases.

10.
Gut Pathog ; 1(1): 17, 2009 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-19772668

RESUMO

A "cluster" of patients refers to the geographic proximity of unrelated patients with the same disease and suggests a common environmental cause for that disease. Clusters of patients with Crohn's disease have been linked to the presence of an infectious microorganism in unpasteurized milk and cheese, untreated water supplied by wells or springs, animal manure used as fertilizer for family vegetable gardens, and bodies of water contaminated by agricultural runoff. Mycobacterium avium subspecies paratuberculosis (MAP) is the suspected cause of Crohn's disease. MAP causes a disease in dairy cows and other animals that is similar to Crohn's disease, called Johne's ('Yo-knees') disease or paratuberculosis. Dairy cows with Johne's disease secrete MAP into their milk and excrete MAP into their feces. MAP is present in untreated water such as well water, in bodies of water contaminated by agricultural runoff, and in unpasteurized milk and cheese. The "treatment" of "tap" water to make it "drinkable" or "potable" by the processes of sedimentation, filtration and chlorination has little to no effect on MAP. MAP is so resistant to chlorine disinfection that such disinfection actually selects for its growth. Other subspecies of Mycobacterium avium grow in biofilms present on tap water pipes. Despite the documented presence of MAP in tap water and its probable growth on tap water pipes, clusters of Crohn's disease have not previously been described in relationship to tap water pipes supplying patients' homes. This report describes three unrelated individuals who lived on the same block along a street in a midwestern American city and developed Crohn's disease within four years of each other in the 1960's. A common tap water pipe supplied their homes. This is the first reported cluster of Crohn's disease possibly linked to fully treated drinking water, and is consistent with previously reported clusters of Crohn's disease linked to an infectious microorganism in water.

11.
PLoS Pathog ; 5(3): e1000234, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19325887

RESUMO

Mycobacterium avium subspecies paratuberculosis (MAP) causes a chronic granulomatous inflammation of the intestines, Johne's disease, in dairy cows and every other species of mammal in which it has been identified. MAP has been identified in the mucosal layer and deeper bowel wall in patients with Crohn's disease by methods other than light microscopy, and by direct visualization in small numbers by light microscopy. MAP has not been accepted as the cause of Crohn's disease in part because it has not been seen under the microscope in large numbers in the intestines of patients with Crohn's disease. An analysis of the literature on the pathology of Crohn's disease and on possible MAP infection in Crohn's patients suggests that MAP might directly infect endothelial cells and adipocytes and cause them to proliferate, causing focal obstruction within already existing vessels (including granuloma formation), the development of new vessels (neoangiogenesis and lymphangiogenesis), and the "creeping fat" of the mesentery that is unique in human pathology to Crohn's disease but also occurs in bovine Johne's disease. Large numbers of MAP might therefore be found in the mesentery attached to segments of intestine affected by Crohn's disease rather than in the bowel wall, the blood and lymphatic vessels running through the mesentery, or the mesenteric fat itself. The walls of fistulas might result from the neoangiogenesis or lymphangiogenesis that occurs in the bowel wall in Crohn's disease and therefore are also possible sites of large numbers of MAP. The direct visualization of large numbers of MAP organisms in the tissues of patients with Crohn's disease will help establish that MAP causes Crohn's disease.


Assuntos
Doença de Crohn/microbiologia , Doença de Crohn/patologia , Paratuberculose/complicações , Humanos , Mycobacterium avium subsp. paratuberculosis
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA