Toxocara cati Infection in Cats (Felis catus): A Systematic Review and Meta-Analysis.

Introduction: Toxocariasis is an infection caused in canines, felines, humans, and other vertebrates by species of the genus Toxocara, such as T. canis and T. cati. The embryonated eggs of these parasites are the primary means of acquiring the infection for both definitive hosts, dogs and cats, respectively, and for intermediates, such as humans and other vertebrates. When deposited on park soils, environmental contamination becomes a risk to environmental, human, and animal health. Objective: To determine the global prevalence of Toxocara cati in cats (Felis catus). Methods: A systematic review of the literature was carried out in six databases (Scopus, PubMed, ScienceDirect, SciELO and Google Scholar) to evaluate the global prevalence of Toxocara cati in cats, defined by coproparasitological, histological, and molecular techniques. A meta-analysis was performed using a random effects model to calculate pooled prevalence and 95% confidence intervals (95% CI). A two-tailed 5% alpha level was used for hypothesis testing. Results: Two hundred and eighty-nine studies were included. The global pooled prevalence of Toxocara cati in cats using coproparasitological methods was 17.0% (95.0% CI: 16.2-17.8%). In the subgroup analysis according to country, Nepal had the highest prevalence of T. cati infection (94.4%; 95% CI 89.7-99.2%). The pooled prevalence of T. cati infection by PCR in four studies was 4.9% (95.0% CI: 1.9-7.9%). Conclusions: This systematic review underscores the need for preventive action against toxocariasis due to its widespread prevalence. The interplay between animal and human health should be emphasised, necessitating measures like deworming cats, hygiene practices, and public education to mitigate risks. Safeguarding feline health can also reduce human transmission, benefiting both species.

Prevalence of human cryptosporidiosis in the Americas: systematic review and meta-analysis.

Cryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the pathogen at the species or genotype level is of great importance to define the sources of infection for humans and the potential for public health. This study investigated the diversity of the genus Cryptosporidium spp. in humans from all over the American continent and observed whether the method used to search for the parasite influenced the prevalence found in the Americas. This systematic review was carried out using the Pubmed, Science direct, Lilacs, Scielo, and Scopus databases with publications from January 1, 2010, to December 31, 2020. For data synthesis, the PRISMA flowchart was used and for the meta-analysis we used the MetaXL program. Of the selected publications, 57, 9 and 16 belonged to the region of South, Central and North America, respectively. The prevalence found for South, Central, and North America was 7%, 7%, and 8%, respectively, when analyzing publications that used only the microscopy method. When we analyzed the publications that used immunological and molecular methods, we found prevalences of 10%, 9%, and 21% for South, Central, and North America, respectively. The C. hominis subtype IbA10G2 was the most reported in the American continent, followed by subtype IeA11G3T3 and, for C. parvum, subtype IIaA15G2RI was the most reported. In conclusion, Cryptosporidium spp. is present throughout the American continent and its prevalence is higher when immunological and/or molecular methods are used, in addition to direct microscopic examination.

Prevalence of human cryptosporidiosis in the Americas: systematic review and meta-analysis

ABSTRACT Cryptosporidiosis is a disease caused by the Cryptosporidium spp parasite. As some species of Cryptosporidium have a wide host spectrum, the characterization of the pathogen at the species or genotype level is of great importance to define the sources of infection for humans and the potential for public health. This study investigated the diversity of the genus Cryptosporidium spp. in humans from all over the American continent and observed whether the method used to search for the parasite influenced the prevalence found in the Americas. This systematic review was carried out using the Pubmed, Science direct, Lilacs, Scielo, and Scopus databases with publications from January 1, 2010, to December 31, 2020. For data synthesis, the PRISMA flowchart was used and for the meta-analysis we used the MetaXL program. Of the selected publications, 57, 9 and 16 belonged to the region of South, Central and North America, respectively. The prevalence found for South, Central, and North America was 7%, 7%, and 8%, respectively, when analyzing publications that used only the microscopy method. When we analyzed the publications that used immunological and molecular methods, we found prevalences of 10%, 9%, and 21% for South, Central, and North America, respectively. The C. hominis subtype IbA10G2 was the most reported in the American continent, followed by subtype IeA11G3T3 and, for C. parvum, subtype IIaA15G2RI was the most reported. In conclusion, Cryptosporidium spp. is present throughout the American continent and its prevalence is higher when immunological and/or molecular methods are used, in addition to direct microscopic examination.

Effects of multiple doses of simvastatin and artesunate monotherapy on SCHISTOSOMA MANSONI adult worms during infection in hyperlidemic mice / Efectos de múltiples dosis de simvastatina y artesunato en monoterapia en gusanos adultos de SCHISTOSOMA MANSONI durante la infección en ratones hiperlidémicos / Efeitos de doses múltiplas de monoterapia com sinvastatina e artesunato em vermes adultos SCHISTOSOMA MANSONI durante a infecção em camundongos hiperlidêmicos

A single dose of simvastatin and of artesunate monotherapy cause damage to the reproductive system of schistosomes as well as severe tegumental damage in male worms recovered from mice fed high-fat chow. This study aims to investigate whether treatment with multipledose regimes may offer more antischistosomal activity advantages than single daily dosing in mice fed high-fat chow. For this purpose, nine weeks post-infection, Swiss Webster mice were gavaged with simvastatin (200 mg/kg) or artesunate (300 mg/kg) for five consecutive days and euthanized two weeks post-treatment. Adult worms were analyzed using brightfield microscopy, confocal microscopy and scanning electron microscopy, presenting damages caused by simvastatin and artesunate to the reproductive system of males and females as well as tegument alterations, including peeling, sloughing areas, loss of tubercles, tegumental bubbles and tegument rupture exposing subtegumental tissue. The overall findings in this study revealed the potential antischistosomal activity of simvastatin and artesunate against Schistosoma mansoni adult worms, in addition to showing that multiple doses of either monotherapy caused severe damage to the tegument.

Una sola dosis de simvastatina y de artesunato en monoterapia causa daño al sistema reproductivo de los esquistosomas, así como daño tegumental severo en gusanos machos recuperados de ratones alimentados con comida rica en grasas. Este estudio tiene como objetivo investigar si el tratamiento con regímenes de dosis múltiples puede ofrecer más ventajas de actividad antiesquistosomal que la dosis única diaria en ratones alimentados con comida rica en grasas. Para este propósito, nueve semanas después de la infección, los ratones Swiss Webster se alimentaron por sonda con simvastatina (200 mg / kg) o artesunato (300 mg / kg) durante cinco días consecutivos y se sacrificaron dos semanas después del tratamiento. Los gusanos adultos se analizaron utilizando campo claro microscopía, microscopía confocal y microscopía electrónica de barrido, presentando daños causados ​​por simvastatina y artesunato en el sistema reproductivo de machos y hembras, así como alteraciones del tegumento, incluyendo descamación, desprendimiento, pérdida de tubérculos, burbujas tegumentales y rotura del tegumento exponiendo tejido subtegumental. Los hallazgos generales de este estudio revelaron la posible actividad antiesquistosomal de la simvastatina y el artesunato contra los gusanos adultos de Schistosoma mansoni, además de mostrar que dosis múltiples de cualquiera de las dos monoterapia causaron daños graves al tegumento.

Uma única dose de sinvastatina e de monoterapia com artesunato causa danos ao sistema reprodutivo dos esquistossomos, bem como danos graves ao tegumento em vermes machos recuperados de camundongos alimentados com ração rica em gordura. Este estudo tem como objetivo investigar se o tratamento com regimes de múltiplas doses pode oferecer mais vantagens da atividade anti-esquistossomótica do que uma única dose diária em ratos alimentados com ração rica em gordura. Para tanto, nove semanas após a infecção, camundongos Swiss Webster foram inoculados com sinvastatina (200 mg / kg) ou artesunato (300 mg / kg) por cinco dias consecutivos e sacrificados duas semanas após o tratamento. Vermes adultos foram analisados ​​usando campo claro microscopia, microscopia confocal e microscopia eletrônica de varredura, apresentando danos causados ​​pela sinvastatina e artesunato ao sistema reprodutivo de homens e mulheres, bem como alterações do tegumento, incluindo descamação, áreas de descamação, perda de tubérculos, bolhas tegumentais e ruptura do tegumento com exposição de tecido subtegumentar. Os achados gerais deste estudo revelaram a potencial atividade anti-esquistossomótica da sinvastatina e do artesunato contra vermes adultos do Schistosoma mansoni, além de mostrar que doses múltiplas de ambas as monoterapias causaram danos graves ao tegumento.

Tratamientos alternativos en tumor venéreo transmisible en caninos / Alternative treatments in transmissible venereal tumor in canines / Tratamentos alternativos em tumor venéreo transmissível em caninos

Resumen El Tumor Venéreo Transmisible (TVT), es una neoplasia común de la especie canina, se localiza principalmente en la mucosa de los genitales; es altamente contagiosa y es la única que puede ser transmisible mediante el trasplante celular por contacto directo. Se diagnostica por estudio citológico y su tratamiento es la quimioterapia con sulfato de vincristina, fármaco de elección por tener un alto porcentaje de efectividad y baja recidiva; sin embargo, se han descrito efectos adversos como trastornos digestivos, hemáticos y nerviosos por parte de la población tratada. El objetivo de este trabajo es dar a conocer la efectividad y comportamiento de otras alternativas para el tratamiento de TVT; primero con un protocolo de autohemoterapia y el otro mediante la inmunoterapia con ácido yatrénico mas caseína, que actúan sobre el sistema inmunológico del animal, haciendo que sea el mismo organismo quien realice la eliminación del tumor.

Abstract Transmissible Venereal Tumor (TVT) is a common canine neoplasia; it is mainly located in the genital mucosa. This pathology is highly contagious and can be transmitted by direct contact cell transplantation from a diseased to a non-diseased mucosa. It is primarily diagnosed by cytology and its treatment is chemotherapy being the vincristine sulfate the medicine of choice. The Vincristine has a high rate of effectiveness and low recidivism; however, this alternative has important side effects. The treatment with Vincristine could cause primarily digestive upset, hematological, and nervous diseases. The objective of this work is to determine the efficacy and performance of alternative therapies for the treatment of TVT, firstly, with an autohemoterapy protocol, and using an immunotherapy treatment with yatrenic acid and casein, which acts in the animal's immune system and causes the same organism to eradicate the tumor.

Resumo O Tumor Venéreo Transmissível (TVT), é uma neoplasia comum da espécie canina, localiza-se principalmente na mucosa dos genitais; é altamente contagioso e é o único que pode ser transmitido por transplante de células de contato direto. É diagnosticado por estudo citológico e seu tratamento é a quimioterapia com sulfato de vincristina, a droga de escolha por apresentar alto percentual de eficácia e baixa recorrência; entretanto, efeitos adversos como distúrbios digestivos, sanguíneos e nervosos foram relatados na população tratada. O objetivo deste trabalho é apresentar a eficácia e o comportamento de outras alternativas para o tratamento do TVT; a primeira com um protocolo de auto-hemoterapia e a outra por meio de imunoterapia com ácido yatrênico mais caseína, que atuam no sistema imunológico do animal, fazendo com que o mesmo organismo realize a retirada do tumor.

Whipworm Infection Promotes Bacterial Invasion, Intestinal Microbiota Imbalance, and Cellular Immunomodulation.

Infections with Trichuris trichiura are among the most common causes of intestinal parasitism in children worldwide, and the diagnosis is based on microscopic egg identification in the chronic phase of the infection. During parasitism, the adult worm of the trichurid nematode maintains its anterior region inserted in the intestinal mucosa, which causes serious damage and which may open access for gut microorganisms through the intestinal tissue. The immune-regulatory processes taking place during the evolution of the chronic infection are still not completely understood. By use of the Swiss Webster outbred mouse model, mice were infected with 200 eggs, and tolerance to the establishment of a chronic Trichuris muris infection was induced by the administration of a short pulse of dexamethasone during nematode early larval development. The infected mice presented weight loss, anemia, an imbalance of the microbiota, and intense immunological cell infiltration in the large intestine. It was found that mice have a mixed Th1/Th2/Th17 response, with differences being found among the different anatomical locations. After 45 days of infection, the parasitism induced changes in the microbiota composition and bacterial invasion of the large intestine epithelium. In addition, we describe that the excretory-secretory products from the nematode have anti-inflammatory effects on mouse macrophages cultured in vitro, suggesting that T. muris may modulate the immune response at the site of insertion of the worm inside mouse tissue. The data presented in this study suggest that the host immune state at 45 days postinfection with T. muris during the chronic phase of infection is the result of factors derived from the worm as well as alterations to the microbiota and bacterial invasion. Taken together, these results provide new information about the parasite-host-microbiota relationship and open new treatment possibilities.

Coinfections and differential diagnosis in immunocompetent patients with uveitis of infectious origin.

BACKGROUND: Making a definite diagnosis of infectious uveitis is a challenging task because many other infectious, and non-infectious uveitis, may have similar non-specific symptoms and overlapping clinical appearances. Co-infections in immunocompetent patients are not frequently proved with traditional serologic-diagnostic tools. METHODS: Descriptive transversal study, in a Uveitis Service of an Ophthalmology Reference Center, in Bogotá, Colombia, from July 2014 to February 2016. Aqueous humor (AH) and/or vitreous fluid, blood and serum samples were collected from consecutive patients suspected of having infectious uveitis. The diagnosis of ocular toxoplasmosis (OT) was confirmed by the Goldmann-Witmer coefficient (GWC) and by polymerase chain reaction (PCR). Differential diagnosis by PCR in AH was done for viral origin such as Cytomegalovirus (CMV), Herpes simplex virus type 1 (HSV1), Herpes simplex virus type 2 (HSV2), Varicella zoster virus (VZV), Epstein-Barr virus (EBV) and Mycobacterium tuberculosis. RESULTS: In 66 Colombian patients with uveitis of presumed infectious origin: 22 (33.3%) were confirmed as OT, 16 (24.2%) as undetermined OT, five (7.5%) as co-infections and 23 (34.8%) as other uveitis. Toxoplasma coinfection with M. tuberculosis was identified in one case by PCR and in four cases with HSV by GWC. The initial clinical diagnosis changed, after laboratory examination, in 21 cases (31.8%). CONCLUSIONS: Clinical diagnosis can be changed by laboratory examination in a significant proportion of cases of uveitis. Diagnosis of OT should combine the use of PCR and GWC to reach the maximum of confirmation of cases. The use of multiple laboratory methods is necessary to identify co-infections and viral infections that can mimic OT in immunocompetent patients.

Occurrence of Capillaria sp. in the liver of sheep (Ovis aries ) in a slaughterhouse in the state of Acre, Brazil.

Although sheep farming has grown in the state of Acre over the past four decades, little is known about occurrences of helminthiases in the herds of this region. The objective of the study was to assess the occurrences of non-intestinal helminthiasis among sheep slaughtered in Rio Branco. A total of 110 sheep livers were inspected from two slaughter batches (july 2014 and march 2015) in a slaughterhouse in Rio Branco. Livers with macroscopic lesions were photographed and were then subjected to histopathological analysis under an optical microscope. The macroscopic lesions showed small nodes with inflammatory characteristics and areas of fibrosis, which appeared to be calcified, thus suggesting a granulomatous reaction. Of the 110 evaluated livers, we noticed 110 nodules in total; these nodules have an average size of 0.5 cm. The histopathological analysis showed alterations to the architecture of the hepatic lobe, with multiple foci of necrosis and polymorphonuclear cells. Two samples revealed the presence of helminths from Nematode class and Capillaria sp. eggs identified by the typical morphology and morphometry. This seems to be the first report of Capillaria sp. in sheep livers in Brazil, and it serves as an important alert regarding animal health surveillance and control and regarding the Capillaria sp. zoonotic role in humans.

Occurrence of Capillaria sp. in the liver of sheep (Ovis aries ) in a slaughterhouse in the state of Acre, Brazil / Ocorrência de Capillaria sp. em fígado de ovino ( Ovis aries) em um abatedouro no estado do Acre, Brasil

Although sheep farming has grown in the state of Acre over the past four decades, little is known about occurrences of helminthiases in the herds of this region. The objective of the study was to assess the occurrences of non-intestinal helminthiasis among sheep slaughtered in Rio Branco. A total of 110 sheep livers were inspected from two slaughter batches (july 2014 and march 2015) in a slaughterhouse in Rio Branco. Livers with macroscopic lesions were photographed and were then subjected to histopathological analysis under an optical microscope. The macroscopic lesions showed small nodes with inflammatory characteristics and areas of fibrosis, which appeared to be calcified, thus suggesting a granulomatous reaction. Of the 110 evaluated livers, we noticed 110 nodules in total; these nodules have an average size of 0.5 cm. The histopathological analysis showed alterations to the architecture of the hepatic lobe, with multiple foci of necrosis and polymorphonuclear cells. Two samples revealed the presence of helminths from Nematode class and Capillaria sp. eggs identified by the typical morphology and morphometry. This seems to be the first report of Capillaria sp. in sheep livers in Brazil, and it serves as an important alert regarding animal health surveillance and control and regarding the Capillaria sp. zoonotic role in humans.(AU)

Embora a ovinocultura tenha despertado o interesse de criadouros no estado do Acre nas últimas quatro décadas, pouco se conhece sobre a ocorrência de helmintoses no plantel de ovinos dessa região. O objetivo do presente estudo foi avaliar a possibilidade de ocorrência de helmintíases não intestinais entre ovinos abatidos no município de Rio Branco. Foram inspecionados 110 fígados de ovinos em dois abates (julho de 2014 e março de 2015) em um abatedouro no município de Rio Branco. Fígados com lesões macroscópicas foram fotografados com posterior análise histopatológica por microscopia de luz. Nas lesões macroscópicas foram encontrados pequenos nódulos apresentando características inflamatórias com áreas de fibrose, aparentemente calcificadas, sugerindo uma reação granulomatosa. Dos 110 fígados avaliados, observou-se 110 nódulos no total; estes nódulos têm um tamanho médio de 0,5 cm. A análise histopatológica mostrou alterações na arquitetura do lóbulo hepático, com múltiplos focos de necrose, além da formação de abscessos hepáticos constituídos por polimorfonucleares. Duas amostras revelaram a presença de helmintos da Classe Nematoda e ovos de Capillaria sp. identificados pela morfologia típica e morfometria. Esse resultado parece ser o primeiro registro de Capillaria sp. em fígado de ovino no Brasil, o que é um importante alerta para a vigilância no controle sanitário animal e o seu papel zoonótico para humanos.(AU)

Occurrence of Capillaria sp. in the liver of sheep (Ovis aries ) in a slaughterhouse in the state of Acre, Brazil / Ocorrência de Capillaria sp. em fígado de ovino ( Ovis aries) em um abatedouro no estado do Acre, Brasil

Abstract Although sheep farming has grown in the state of Acre over the past four decades, little is known about occurrences of helminthiases in the herds of this region. The objective of the study was to assess the occurrences of non-intestinal helminthiasis among sheep slaughtered in Rio Branco. A total of 110 sheep livers were inspected from two slaughter batches (july 2014 and march 2015) in a slaughterhouse in Rio Branco. Livers with macroscopic lesions were photographed and were then subjected to histopathological analysis under an optical microscope. The macroscopic lesions showed small nodes with inflammatory characteristics and areas of fibrosis, which appeared to be calcified, thus suggesting a granulomatous reaction. Of the 110 evaluated livers, we noticed 110 nodules in total; these nodules have an average size of 0.5 cm. The histopathological analysis showed alterations to the architecture of the hepatic lobe, with multiple foci of necrosis and polymorphonuclear cells. Two samples revealed the presence of helminths from Nematode class and Capillaria sp. eggs identified by the typical morphology and morphometry. This seems to be the first report of Capillaria sp. in sheep livers in Brazil, and it serves as an important alert regarding animal health surveillance and control and regarding the Capillaria sp. zoonotic role in humans.

Resumo Embora a ovinocultura tenha despertado o interesse de criadouros no estado do Acre nas últimas quatro décadas, pouco se conhece sobre a ocorrência de helmintoses no plantel de ovinos dessa região. O objetivo do presente estudo foi avaliar a possibilidade de ocorrência de helmintíases não intestinais entre ovinos abatidos no município de Rio Branco. Foram inspecionados 110 fígados de ovinos em dois abates (julho de 2014 e março de 2015) em um abatedouro no município de Rio Branco. Fígados com lesões macroscópicas foram fotografados com posterior análise histopatológica por microscopia de luz. Nas lesões macroscópicas foram encontrados pequenos nódulos apresentando características inflamatórias com áreas de fibrose, aparentemente calcificadas, sugerindo uma reação granulomatosa. Dos 110 fígados avaliados, observou-se 110 nódulos no total; estes nódulos têm um tamanho médio de 0,5 cm. A análise histopatológica mostrou alterações na arquitetura do lóbulo hepático, com múltiplos focos de necrose, além da formação de abscessos hepáticos constituídos por polimorfonucleares. Duas amostras revelaram a presença de helmintos da Classe Nematoda e ovos de Capillaria sp. identificados pela morfologia típica e morfometria. Esse resultado parece ser o primeiro registro de Capillaria sp. em fígado de ovino no Brasil, o que é um importante alerta para a vigilância no controle sanitário animal e o seu papel zoonótico para humanos.

Simvastatin and artesunate impact the structural organization of adult Schistosoma mansoni in hypercholesterolemic mice.

Experimental data have shown that simvastatin and artesunate possess activity against Schistosoma mansoni worms in mice fed standard chow. However, little is known regarding the roles of these drugs in mice fed high-fat chow. We have extended past studies by measuring the effects of these drugs on the structural organization of adult schistosomes in hypercholesterolemic mice. For this purpose, mice were gavaged with either simvastatin or artesunate at nine weeks post-infection and were euthanized by cervical dislocation at two weeks post-treatment. Adult worms were then collected and examined by conventional light microscopy, morphometry and confocal laser scanning microscopy. Plasma total cholesterol and worm reduction rates were significantly increased in mice fed high-fat chow compared with their respective control groups. Simvastatin and artesunate caused changes in the tegument, tubercles, and reproductive system (testicular lobes, vitelline glands and ovarian cells), particularly when administered to mice fed high-fat chow. In particular, the tegument and tubercles were significantly thinner in artesunate-treated worms in mice fed high-fat chow compared with mice fed standard chow. This study thus demonstrated that simvastatin and artesunate have several novel effects on the structural organization of adult worms. Together, these results show, for the first time, that simvastatin and artesunate display antischistosomal activity in hypercholesterolemic mice.

First report of equine Pegivirus in South America, Brazil.

The human Pegivirus (HPgV, also known as GBV-C virus or hepatitis G virus) is a lymphotropic RNA-virus phylogenetically related to the Hepatitis C virus, which infects approximately 5% of the world's human population. Recently, two novel, presumably hepatotropic, pegiviruses, designated as equine Pegivirus (EPgV) and Theiler's Disease Associated Virus (TDAV), were discovered in horses with clinical and laboratory evidence of hepatic disease. To verify the occurrence of pegiviruses infection in horses from Pará State, northern Brazil, serum samples from 114 horses located in four cities (Acará, Belém, Dom Eliseu and Ananindeua) were submitted for the molecular analysis of EPgV by nested RT-PCR. The results of nucleotide sequencing and phylogenetic analysis of EPgV NS3 and NS5B genomic regions confirmed one positive sample among 114 tested samples (1/114; 0.8%). No evidence of TDAV infection was found, but despite the low prevalence and unknown clinical significance among the studied population, these results represent the first molecular detection of EPgV in horses in South America.

Changes in the small intestine of Schistosoma mansoni-infected mice fed a high-fat diet.

The consumption of a high-fat diet modifies both the morphology of the small intestine and experimentally tested effects of schistosomiasis mansoni. However, whether a schistosomiasis infection associated with a high-fat diet causes injury to the small intestine has never been investigated. Mice were fed either a high-fat or a standard-fat diet for 6 months and were then infected with Schistosoma mansoni cercariae. Physical characteristics of the intestinal tissue (mucosal thickness, small intestinal villi length and height, and abundance of goblet cells and enterocytes on the villous surface) and the distribution of granulomas along the intestinal segments and their developmental stage were measured at the time of sacrifice (9 or 17 weeks post-infection). The group fed a high-fat diet exhibited different granuloma stages, whereas the control group possessed only exudative granulomas. The chronically infected mice fed a high-fat diet exhibited higher granuloma and egg numbers than the acutely infected group. Exudative, exudative/exudative-productive and exudative-productive granulomas were present irrespective of diet. Computer-aided morphometric analysis confirmed that villus length, villus width, muscular height and submucosal height of the duodenal and jejunal segments were affected by diet and infection. In conclusion, a high-fat diet and infection had a significant impact on the small intestine morphology and morphometry among the animals tested.

Uso de modelos matemáticos para la descripción del crecimiento de tumores cancerosos / Use mathematical models to describe the growth of cancerous tumors

La producción de tumores cancerosos o tumorgénesis ha sido estudiada desde principios del siglo XX por matemáticos y físicos interesados en aplicaciones biológicas. En este trabajo se plantean diversos modelos que utilizan ecuaciones diferenciales ordinarias, ecuaciones diferenciales parciales, modelos estocásticos discretos, estadísticos y de análisis numérico para describir el crecimiento de tumores cancerosos. Se muestra un análisis comparativo entre estos modelos matemáticos, estableciendo particularidades y limitaciones debido a la especificidad de las poblaciones cancerosas. Se amplía un estudio del modelo de competencia por nutrientes utilizando una simulación computacional, donde se muestran resultados gráficos de las simulaciones para poblaciones de células cancerosas y muertas.

Implicaciones históricas y biológicas del cambio climático: [revisión] / Historical and biological implications of climate change: [review]

Este trabajo presenta una revisión histórica de construcción científica acerca de la problemática del cambio climático y el calentamiento global. Se discuten algunas de las implicaciones sociales, científicas, políticas y educativas que el estudio del fenómeno ha generado. Además se presenta de manera suscinta algunas implicaciones biológicas sobre la influencia en la biodiversidad y el comportamiento de los ecosistemas causado por las alteraciones en el comportamiento del clima global. Las plantas y los animales se han ido adaptando a los cambios en su entorno, tanto a través de la evolución como de la migración. Sin embargo, los modelos recientes publicados demuestran que muchas especies no podrán mantenerse al día con las tasas proyectadas de cambio. Aún más grave es la fragmentación de los hábitats naturales por la actividad humana, problema que no puede ser atribuido a las fuerzas naturales.

High fat diet has a prominent effect upon the course of chronic schistosomiasis mansoni in mice.

This study investigated whether a long-term high-fat diet has an effect on the outcome of chronic murine schistosomiasis mansoni compared to a standard diet. Swiss Webster female mice (3 weeks old) were fed each diet for up to six months and were then infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring total serum cholesterol and body mass. Infected mice were examined 6-17 weeks post infection to estimate the number of eggs in faeces. Mice were euthanised the next day. Total serum cholesterol was lower in infected mice in comparison to uninfected controls (p = 0.0055). In contrast, body mass (p = 0.003), liver volume (p = 0.0405), spleen volume (p = 0.0124), lung volume (p = 0.0033) and faecal (p = 0.0064) and tissue egg density (p = 0.0002) were significantly higher for infected mice fed a high-fat diet. From these findings, it is suggested that a high-fat diet has a prominent effect on the course of chronic schistosomiasis mansoni in mice.

High fat diet has a prominent effect upon the course of chronic schistosomiasis mansoni in mice

This study investigated whether a long-term high-fat diet has an effect on the outcome of chronic murine schistosomiasis mansoni compared to a standard diet. Swiss Webster female mice (3 weeks old) were fed each diet for up to six months and were then infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring total serum cholesterol and body mass. Infected mice were examined 6-17 weeks post infection to estimate the number of eggs in faeces. Mice were euthanised the next day. Total serum cholesterol was lower in infected mice in comparison to uninfected controls (p = 0.0055). In contrast, body mass (p = 0.003), liver volume (p = 0.0405), spleen volume (p = 0.0124), lung volume (p = 0.0033) and faecal (p = 0.0064) and tissue egg density (p = 0.0002) were significantly higher for infected mice fed a high-fat diet. From these findings, it is suggested that a high-fat diet has a prominent effect on the course of chronic schistosomiasis mansoni in mice.

Las condiciones laborales de los profesionales de la salud a partir de la Ley 100 de 1993: evolución y un estudio de caso para Medellín / As condições laborais dos profissionais de saúde a partir da Lei 100 de 1993: evolução e um estudo de caso para Medellín / Labor conditions for health professionals starting from the Act 100 of 1993: evolution and a case study for Medellin

Este artículo pretende analizar los cambios en las condiciones laborales del recurso humano en salud a partir de la Ley 100 de 1993. Para esto, el trabajo se desarrolla en dos partes: la primera presenta un análisis de la evolución de las condiciones laborales de los profesionales de la salud con base en fuentes secundarias y la segunda presenta los resultados de una encuesta aplicada a una muestra de profesionales de Medellín. Se encontró que a partir de la aplicación de la Ley, las condiciones laborales se deterioraron, especialmente para aquellos que no poseen contratación directa con las entidades de salud; se ampliaron las brechas salariales; se dieron aumentos en la intensidad horaria y se detectó cierto grado de subempleo.

The purpose of this article is to analyze the major changes in working conditions of human resources in health since Act 100 of 1993. This paper is divided in two parts: the first one refers to the working conditions of health professionals in Colombia based on secondary sources and the second shows the results of a survey of a sample of Medellin professionals. We found that after the implementation of the Act, working conditions have been deteriorated, especially for those professionals who do not have a direct engagement with health agencies, it also has generated wage gaps between professionals from different fields and even within the same; and has increased the working-day hours and underemployment found it in the area.

Este artigo pretende analisar as mudanças nas condições laborais do recurso humano e saúde a partir da Lei 100 de 1993. Para isto, o trabalho se desenvolve em duas partes: a primeira apresenta uma analise da evolução das condições laborais dos profissionais de saúde com base em fontes secundárias; e a segunda, apresenta os resultados de uma pesquisa aplicada a uma amostra de profissionais de Medellín. Os resultados ilustram que a partir da aplicação da Lei, as condições laborais se deterioram, especialmente para aqueles que não têm contratação direita com as entidades de saúde; ampliaram-se as brechas salariais; aumento da intensidade de horários e detectou-se certo grau de desemprego.

Long-term feeding a high-fat diet causes histological and parasitological effects on murine schistosomiasis mansoni outcome.

This study investigated whether long-term feeding a high-fat diet (HFC) has an effect on schistosomiasis mansoni outcome compared to standard chow diet (SC). Swiss Webster female mice (3 wk old) fed each diet over 5 months, and then were infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring growth rates twice a week and measuring serum levels of lipoproteins. Mice were euthanised 63 days after infection. Parasitological and liver histological analyses were performed. The levels of TC, HDL-C and LDL-C, fecal and tissue schistosome eggs were statistically different (p<0.05) between groups. Livers from HFC mice showed exudative, exudative/exudative-productive, exudative-productive and productive granulomas, some degree of hepatic steatosis and focal necrosis. Mice fed normal-chow did not present productive granulomas and hepatic steatosis. The morphometric evaluation of hepatic granulomas did not reach statistical significance (p>0.05) between diets assayed. The high-fat diet for long-term produces effects on schistosomiasis mansoni outcome.

Somatic, Biochemical and Hepatic Alterations in Wild Type Mice Chronically Fed High Fat Diet / Alteraciones Somáticas Bioquímicas y hepáticas en un Tipo de Ratas Alimentadas Crónicamente con Dieta Alta en Grasas

This study evaluated whether a high fat diet (HFC group) induces overweight, hepatic steatosis and plasma lipoproteins level alteration compared to standard chow diet (SC group). Female mice were submitted to each diet over 6 months. Body mass and food intake were evaluated weekly throughout the experiment. Total cholesterol, TG, LDL-c, HDL-c and VLDL-c were analyzed. Mice were sacrificed to remove liver, spleen, heart and intestine. The volume of the organs was determined according to the submersion method. Fixed livers were embedded in paraffin and stained with hematoxylin and eosin and Masson's trichrome. The analysis used a video microscope system and a test-system with 42 test-points. The volume density was estimated for hepatocytes, steatosis and sinusoids. Animals fed HFC had smaller chow intake than SC group. HFC group presented body mass greater than SC. Animals fed HFC showed heavier liver and spleen and lighter intestine than SC (p<0.05), heart mass was not significant between groups. Plasma lipoproteins differed between groups (p<0.05) except VLDL-c and TG fractions. The liver structure was without major alteration in SC group however, HFC mice group showed different degrees of fatty degeneration with micro- and macrovesicular steatosis dispersed in all liver with typical peri-cellular/peri-sinusoidal fibrosis. The quantitative study showed significant (p<0.05) volume density reduction for hepatocytes and sinusoids. In conclusion, our results clearly show that hepatic steatosis can be induced in mouse by such a fat-rich diet without any toxin ingestion, alimentary deficiency and genes depletion.

Este estudio evaluó cómo una dieta de alta densidad energética (grupo ADE) induce sobrepeso, esteatosis hepática y altera los niveles de las lipoproteínas plasmáticas cuando son comparados con la dieta patrón (grupo SC). Hembras de camundongos fueron sometidas a cada una de las dietas durante 6 meses. La masa corporal y la ingestión de alimento fueron evaluadas semanalmente durante el experimento. Además fueron medidos el colesterol total, TG, LDL-c, HDL-c e VLDL-c. Los animales fueron sacrificados y el hígado, bazo, corazón e intestinos fueron removidos para estudio. El volumen de los órganos fue medido por el método de la sumersión. Fragmentos de hígado fueron preparados para el estudio en microscopía de luz, teñidos con hematoxilina-eosina y tricrómico de Masson. El análisis fue realizado con video microscopía y sistema test M42. La densidad de volumen fue estimada para hepatocitos, esteatosis y sinusoides. Los animales alimentados con dieta ADE presentaron menor ingestión de alimento y tuvieron masa corporal mayor que los animales con dieta patrón. Animales ADE mostraron también hígado y bazo más pesados e intestino más liviano que animales SC (p<0.05). Para la masa del corazón no hubo diferencia significativa entre los dos grupos. Las lipoproteínas plasmáticas fueron diferentes entre los grupos (p<0.05) excepto VLDL-c y fracciones de TG. La estructura hepática no presentó grandes alteraciones en el grupo SC; sin embargo, animales del grupo ADE presentaron diferentes grados de degeneración adiposa con esteatosis macro y microvesicular dispersas en todo el hígado con típica fibrosis pericelular y perisinusoidal, y significativa reducción de la densidad de volumen de hepatocitos y sinosoides. En conclusión, los resultados muestran que la esteatosis hepática puede ser inducida experimentalmente en camundongos, a través de dieta ADE, sin ingestión de cualquier toxina, deficiencia alimentaria o depleción genética.