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Barros NLC, Ribeiro ML, Freitas AR, Delai RR, Kmetiuk LB, Teixeira WSR, Appolinario CM, Pimpão CT, Ponsart C, Vicente AF, Biondo AW, Megid J. Serological and Molecular Survey of Brucella Species in Owners and Their Dogs Living on Island and Mainland Seashore Areas of Brazil. Vector Borne Zoonotic Dis 2024; 24:104-110. [PMID: 37910779 DOI: 10.1089/vbz.2023.0061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Background: Although Brucella abortus, Brucella suis, and Brucella canis may infect humans and dogs worldwide, no study to date has assessed and compared owners and their dogs between island and mainland seashore areas. Materials and Methods: Accordingly, the study herein has applied serological tests, including Microplate Agglutination Test with 2-Mercaptoethanol, immunochromatographic assay, and Rose Bengal Test, and a Brucella genus-specific PCR assay to 195 owners and their 148 dogs living on 1 mainland seashore area and three nearby oceanic islands of southern Brazil. Results: No seropositivity to B. abortus and B. suis was detected in owner or dog sera. Anti-B. canis seropositivity was observed in 3/148 (2.0%) dogs, but no owner sample was seropositive to B. canis. In addition, all blood samples from both owners and dogs were negative on Brucella genus-specific PCR assay. Conclusions: The seropositive dogs were not related and lived on the seashore mainland area of Guaraqueçaba city. The absence of seropositivity on the islands and the low seropositivity on the seashore mainland could be attributed to geographic isolation, and suggest the low impact of the disease in the region. Despite being a zoonotic disease, brucellosis by B. canis is not included in the National Program for Control and Eradication of Brucellosis, and its diagnosis and notification are not mandatory. The presence of seropositive dogs highlights the risk to human health and the importance of epidemiological surveillance actions in the region, as well as the need for the implantation of preventive measures to avoid the transmission of the pathogen.
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Affiliation(s)
- Noelia Layslla Costa Barros
- Department of Animal Production and Preventive Veterinary Medicine, São Paulo State University (UNESP), Botucatu, Brazil
| | - Matheus Lopes Ribeiro
- Department of Animal Production and Preventive Veterinary Medicine, São Paulo State University (UNESP), Botucatu, Brazil
| | | | - Ruana Renostro Delai
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná (PUCPR), Curitiba, Brazil
| | - Louise Bach Kmetiuk
- Department of Veterinary Medicine, Federal University of Paraná (UFPR), Curitiba, Brazil
| | - Wanderson Sirley Reis Teixeira
- Department of Animal Production and Preventive Veterinary Medicine, São Paulo State University (UNESP), Botucatu, Brazil
| | - Camila Michele Appolinario
- Department of Animal Production and Preventive Veterinary Medicine, São Paulo State University (UNESP), Botucatu, Brazil
| | - Claudia Turra Pimpão
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná (PUCPR), Curitiba, Brazil
| | - Claire Ponsart
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), National/EU/WOAH, Maisons-Alfort, France
| | - Acacia Ferreira Vicente
- French Agency for Food, Environmental and Occupational Health & Safety (ANSES), National/EU/WOAH, Maisons-Alfort, France
| | | | - Jane Megid
- Department of Animal Production and Preventive Veterinary Medicine, São Paulo State University (UNESP), Botucatu, Brazil
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Freitas AR, Delai RR, Kmetiuk LB, Gaspar RC, da Silva EC, Martini R, Biondo LM, Giuffrida R, de Barros Filho IR, Santarém VA, Langoni H, Pimpão CT, Biondo AW. Spatial Owner-Dog Seroprevalence of Leptospira spp. Antibodies in Oceanic Islands and Costal Mainland of Southern Brazil. Trop Med Infect Dis 2023; 8:tropicalmed8040229. [PMID: 37104354 PMCID: PMC10141485 DOI: 10.3390/tropicalmed8040229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 04/28/2023] Open
Abstract
Leptospirosis has been described as a disease neglected worldwide. Affecting humans and animals, the disease is often related to poor environmental conditions such as lack of sanitation and presence of synanthropic rodents. Despite being considered as a One Health issue, no study has focused on comparing owner-dog seroprevalence between islands and seashore mainland. Accordingly, the present study assessed anti-Leptospira spp. antibodies by applying microscopic agglutination test (MAT) methods to Leptospira and assessing associated risk factors via univariate and multivariate logistic regression analysis of owners and their dogs in islands and seashore mainland of southern Brazil. No anti-Leptospira spp. Seropositivity was found in 330 owner serum samples, while dogs presented an overall seroprevalence of 5.9%. All seropositive dogs reacted to serogroups of Leptospira interrogans, including 66.7% of Pyrogenes, 44.4% Canicola, 22.2% Icterohaemorrhagiae, 16.7% Australis; six reacted to more than one serogroup. No association was found among seropositivity and epidemiological variables, except that neighborhood dogs were less likely to be seropositive. Although no seropositivity was observed in owners, seropositivity in dogs had the potential to indicate such species as being sentinels for environmental exposure and potential human risk of infection.
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Affiliation(s)
- Aaronson Ramathan Freitas
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
| | - Ruana Renostro Delai
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná, Curitiba 80230-130, PR, Brazil
| | - Louise Bach Kmetiuk
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
| | - Raquel Cuba Gaspar
- Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animals Science, São Paulo State University, Botucatu 18618-681, SP, Brazil
| | - Evelyn Cristine da Silva
- Institute of Biotechnology, São Paulo State University (UNESP), Tecomarias Avenue, Botucatu 18607-440, SP, Brazil
| | - Rafaella Martini
- Department of Physiology, Federal University of Paraná State, Curitiba 81530-000, PR, Brazil
| | | | - Rogério Giuffrida
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo, São Paulo 19001-970, SP, Brazil
| | | | - Vamilton Alvares Santarém
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo, São Paulo 19001-970, SP, Brazil
| | - Helio Langoni
- Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animals Science, São Paulo State University, Botucatu 18618-681, SP, Brazil
| | - Cláudia Turra Pimpão
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná, Curitiba 80230-130, PR, Brazil
| | - Alexander Welker Biondo
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
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Kmetiuk LB, Paula WVDF, Pádua GT, Delai RR, Freitas AR, Farinhas JH, de Paula LGF, Giuffrida R, Pimpão CT, Álvares Santarém V, Dos Santos AP, Figueiredo FB, Krawczak FDS, Biondo AW. Epidemiology of Rickettsia spp. in Atlantic rainforest areas of island and seashore mainland, southern Brazil. Transbound Emerg Dis 2022; 69:3597-3605. [PMID: 36196667 DOI: 10.1111/tbed.14723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/30/2022] [Accepted: 09/30/2022] [Indexed: 02/04/2023]
Abstract
Non-fatal cases of rickettsial infection with different clinical features than the classic BSF (Brazilian Spotted Fever) have been reported in seashore areas of Paraná state, southern Brazil. In addition, Amblyomma ovale tick infected by Rickettsia parkeri strain Atlantic rainforest has been also described in this area. Accordingly, the aim of this study was to investigate the occurrence of anti-Rickettsia spp. antibodies in human and dog populations, and Rickettsia spp. infection in ticks from oceanic islands and seashore mainland cities of southern Brazil. Serum samples were collected from 328 persons and their 282 dogs from three islands and two seashore mainland cities. A total of 211 ticks were collected from dogs, identified as A. ovale and R. sanguineus. In overall, 40 of 328 (12.2%) human samples were seropositive for Rickettsia spp., including 21 of 190 (11.1%) on islands and 19 of 138 (13.7%) on seashore mainland, and 62 of 282 (22.0%) dog samples, including 31 of 153 (20.3%) on islands and 31 of 129 (24.0%) in seashore mainland areas. In overall, nine of 82 (11.0%) ticks were positive to real-time PCR assay targeting a fragment of the rickettsial gltA gene, including two of 64 (3.1%) Rickettsia sanguineus and seven of 18 (38.9%) A. ovale, of which four were infected with the R. parkeri strain Atlantic rainforest. Despite no association between risk factors and Rickettsia spp. seropositivity was found in human beings, access to natural areas (p = .011) and tick infestation (p = .004) was significantly associated to dog seropositivity. The serological and molecular findings herein have confirmed previous tick and clinical case reports and enlarged the geographical occurrence of A. ovale infected by R. parkeri strain Atlantic rainforest in oceanic islands and seashore mainland cities of Paraná State, indicating a new likely transmission area of this new rickettsial infection in human beings and dogs of southern Brazil.
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Affiliation(s)
- Louise Bach Kmetiuk
- Laboratory of Cell Biology, Instituto Carlos Chagas, Fundação Oswaldo Cruz, Curitiba, Brazil
| | | | - Gracielle Teles Pádua
- School of Veterinary Medicine and Animal Science, Federal University of Goiás, Goiânia, Brazil
| | - Ruana Renostro Delai
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba, Brazil
| | | | | | | | - Rogério Giuffrida
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo (UNOESTE), Presidente Prudente, Brazil
| | - Claudia Turra Pimpão
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná, Curitiba, Brazil
| | - Vamilton Álvares Santarém
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo (UNOESTE), Presidente Prudente, Brazil
| | - Andrea Pires Dos Santos
- Department of Comparative Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, Indiana, USA
| | | | | | - Alexander Welker Biondo
- School of Veterinary Medicine and Animal Science, Federal University of Goiás, Goiânia, Brazil
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Freitas AR, Delai RR, Kmetiuk LB, da Silva EC, Martini R, Brandão APD, Giuffrida R, de Barros-Filho IR, Costa da Silva R, Langoni H, Figueiredo FB, Pimpão CT, Dos Santos AP, Santarém VA, Biondo AW. Seropositivity of Anti- Toxoplasma gondii Antibodies in Owners and Their Dogs Living on Island and Mainland Seashore Areas of Southern Brazil. Trop Med Infect Dis 2022; 7:252. [PMID: 36287993 PMCID: PMC9611663 DOI: 10.3390/tropicalmed7100252] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/02/2022] [Accepted: 08/11/2022] [Indexed: 07/29/2023] Open
Abstract
Although toxoplasmosis has been considered among the most neglected zoonoses worldwide, no study has focused on the frequency and associated risk factors of owners and their dogs living on an island and mainland seashore areas. Accordingly, anti-Toxoplasma gondii IgG antibodies were screened by indirect fluorescent antibody test (IFAT) in owners and dogs from three oceanic islands and two nearby mainland harbor areas, with associated risk factors for toxoplasmosis assessed by univariable and multivariable logistic regression models. Overall, anti-T. gondii seropositivity was observed in 59/328 (18.0%) owners and 66/283 (23.3%) dogs, with no statistical difference between owners (p = 0.360) and dogs (p = 0.655) from islands and mainland areas. Consumption of local water springs (p = 0.016; OR = 2.11) was an associated risk factor for T. gondii seropositivity, and owners with the habit of spring water intake were twice more likely seropositive (p = 0.014; OR = 2.14). Presence of anti-T. gondii antibodies in dogs was associated with seropositive owners (p = 0.008; OR = 2.81), household consumption of beef meat (p = 0.042; OR = 1.7) and chicken (p = 0.026; OR = 2.9). Despite being lower than the worldwide prevalence, toxoplasmosis seropositivity in owners and their dogs in southern Brazil was influenced by the positive owner, water source, and meat consumption, and not by inhabiting islands or seashore mainland areas, presence of dogs, cats, or both. In addition, drinking water quality should always be considered a critical risk factor for toxoplasmosis on islands.
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Affiliation(s)
- Aaronson Ramathan Freitas
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
| | - Ruana Renostro Delai
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
| | - Louise Bach Kmetiuk
- Laboratory of Cell Biology, Carlos Chagas Institute, Oswaldo Cruz Foundation, Curitiba 81310-020, PR, Brazil
| | - Evelyn Cristine da Silva
- Department of Veterinary Hygiene and Public Health, São Paulo State University, Botucatu 18618-681, SP, Brazil
| | - Rafaella Martini
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
| | | | - Rogério Giuffrida
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo, São Paulo 190019-70, SP, Brazil
| | | | - Rodrigo Costa da Silva
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo, São Paulo 190019-70, SP, Brazil
| | - Hélio Langoni
- Department of Veterinary Hygiene and Public Health, São Paulo State University, Botucatu 18618-681, SP, Brazil
| | - Fabiano Borges Figueiredo
- Laboratory of Cell Biology, Carlos Chagas Institute, Oswaldo Cruz Foundation, Curitiba 81310-020, PR, Brazil
| | - Cláudia Turra Pimpão
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná, Curitiba 80230-130, PR, Brazil
| | - Andrea Pires Dos Santos
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
| | - Vamilton Alvares Santarém
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo, São Paulo 190019-70, SP, Brazil
| | - Alexander Welker Biondo
- Department of Veterinary Medicine, Federal University of Paraná State, Curitiba 80035-050, PR, Brazil
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
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Delai RR, Freitas AR, Kmetiuk LB, Merigueti YFFB, Ferreira IB, Lescano SAZ, Gonzáles WHR, Brandão APD, de Barros-Filho IR, Pettan-Brewer C, Figueiredo FB, dos Santos AP, Pimpão CT, Santarém VA, Biondo AW. One Health approach on human seroprevalence of anti- Toxocara antibodies, Toxocara spp. eggs in dogs and sand samples between seashore mainland and island areas of southern Brazil. One Health 2021; 13:100353. [PMID: 34888410 PMCID: PMC8634035 DOI: 10.1016/j.onehlt.2021.100353] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/18/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022] Open
Abstract
Toxocariasis, caused by Toxocara spp. nematodes, is among the top 5 neglected parasitic diseases worldwide; however, no comprehensive study to date has serologically compared infections in people and their dogs and environmentally contaminated soil or sand of mainland and island locations. Accordingly, this study aimed to assess the seroprevalence of anti-Toxocara antibodies in traditional human seashore populations, the presence of eggs in dogs' feces and hair, and the presence of eggs in environmental samples from islands compared to the adjacent mainland of southern Brazil. Overall, 212/328 (64.6%) people were positive for Toxocara spp. antibodies, including 125/190 (65.8%) island and 87/138 (63.0%) mainland residents. For dog samples, 12/115 (10.43%) were positive for the presence of Toxocara spp. eggs, all from dogs living in islands, and 22/104 (21.15%) dog hair samples contained eggs of Toxocara spp. Environmental contamination with Toxocara spp. eggs was observed in 50/130 (38.46%) samples from all sampled sites. No significant association was found between risk factors (age, sex, educational level, monthly income, owning dogs or cats, ingestion of treated water, and consumption of raw or uncooked meat) and Toxocara spp. seropositivity. The present study is the first concurrent report on people, their dogs, and environmental contamination of Toxocara spp. The high prevalence we observed in the seashore populations of both in island and mainland areas may be caused by exposure to contaminated sand and climatic factors favoring frequent exposure to Toxocara spp. In conclusion, seashore lifestyle and living conditions of both island and mainland areas may have predisposed higher contact with infected pets and contaminated soil, favoring the high prevalence of toxocariasis.
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Affiliation(s)
- Ruana Renostro Delai
- Department of Veterinary Medicine, Federal University of Paraná (UFPR), Curitiba, Paraná (PR) 80035-050, Brazil
| | - Aaronson Ramathan Freitas
- Department of Veterinary Medicine, Federal University of Paraná (UFPR), Curitiba, Paraná (PR) 80035-050, Brazil
| | - Louise Bach Kmetiuk
- Laboratory of Cell Biology, Instituto Carlos Chagas, Fundação Oswaldo Cruz, Curitiba, Paraná, Brazil
| | - Yslla Fernanda Fitz Balo Merigueti
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo (UNOESTE), Presidente Prudente, São Paulo, Brazil
| | - Isabella Braghin Ferreira
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo (UNOESTE), Presidente Prudente, São Paulo, Brazil
| | | | | | | | - Ivan Roque de Barros-Filho
- Department of Veterinary Medicine, Federal University of Paraná (UFPR), Curitiba, Paraná (PR) 80035-050, Brazil
| | - Christina Pettan-Brewer
- Department of Comparative Medicine, School of Medicine, University of Washington, Seattle, USA
- One Health Brasil, Brazil
| | - Fabiano Borges Figueiredo
- Laboratory of Cell Biology, Instituto Carlos Chagas, Fundação Oswaldo Cruz, Curitiba, Paraná, Brazil
| | | | - Cláudia Turra Pimpão
- Department of Animal Science, School of Life Sciences, Pontifical Catholic University of Paraná, Curitiba, Brazil
| | - Vamilton Alvares Santarém
- Laboratory of Veterinary Parasitology, Veterinary Teaching Hospital, University of Western São Paulo (UNOESTE), Presidente Prudente, São Paulo, Brazil
| | - Alexander Welker Biondo
- Department of Veterinary Medicine, Federal University of Paraná (UFPR), Curitiba, Paraná (PR) 80035-050, Brazil
- Corresponding author: Department of Veterinary Medicine, Federal University of Paraná State, Funcionários Street, 1540, Curitiba, Paraná 80035-050, Brazil.
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Gaviolli VRN, Buzanskas ME, Cruz VAR, Savegnago RP, Munari DP, Freitas AR, Alencar MM. Genetic associations between weight at maturity and maturation rate with ages and weights at first and second calving in Canchim beef cattle. J Appl Genet 2012; 53:331-5. [PMID: 22562374 DOI: 10.1007/s13353-012-0100-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Revised: 03/26/2012] [Accepted: 04/20/2012] [Indexed: 10/28/2022]
Abstract
Genetic parameters for weight at maturity (WM), maturation rate (MR), age and weight at first calving (AFC and WFC) and second calving (ASC and WSC) were estimated for females of the Canchim breed. The number of records per trait ranged from 1440 to 1923. The restricted maximum likelihood method was used and the statistical model included the fixed effect of contemporary group and the additive genetic and residual as random effects. The mean heritability estimate and respective standard errors were 0.34±0.05 (WM), 0.13±0.04 (MR), 0.14±0.04 (AFC), 0.44±0.06 (WFC), 0.16±0.06 (ASC) and 0.39±0.06 (WSC). The heritability estimate for WM and MR suggested that it would be possible to achieve changes in the animals' growth curve through selection, but the genetic correlation between these two traits suggested that there would be antagonism between them. Selection for WM would result in animals with later growth and would also affect individuals' sexual precocity. This was also seen from the genetic correlations between WM and the other traits, which ranged from 0.37 to 0.98; and between MR and the other traits, which ranged from -0.83 to -0.25. Selection to modify WM would be expected to result in correlated responses in AFC, WFC and WSC and a moderate response in ASC. Although the heritability estimate for MR was low, selection aimed for its increase might cause a large decrease in AFC, ASC and WFC and a moderate change in WSC, and this could be an alternative for improving the progeny's overall performance.
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Affiliation(s)
- V R N Gaviolli
- Pós-Graduação em Genética e Melhoramento Animal, FCAV/UNESP, Jaboticabal, São Paulo, Brazil
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Bergamaschi MACM, Vicente WRR, Barbosa RT, Marques JA, Freitas AR. Effect of grazing system on fetal development in Nellore cattle. Theriogenology 2004; 61:1237-45. [PMID: 15036958 DOI: 10.1016/j.theriogenology.2003.07.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2002] [Accepted: 07/04/2003] [Indexed: 10/26/2022]
Abstract
Intensive grazing systems for beef females, based on abundant availability of high quality forages and supplementary concentrates, may affect fetal development. The objective of this study was to determine the effect of grazing system on length of gestation, fetal development, and characteristics of the calf at birth. Twenty-four pregnant (bred to Nellore bulls) Nellore females were allocated into two groups. The control group (G1) grazed Brachiaria decumbens (signal grass) in a traditional (extensive) grazing system and the second group (G2) were managed on Panicum maximumcv. Tanzania 1 (Tanzania grass) in an intensive grazing system. Fetal development was evaluated by ultrasonography on days 31, 45, 59, 94, 122, 220, and 255 of gestation. The diameter of the amniotic and allantoic cavities, crown-rump length, circumference, and diameter of the head and ocular orbit were determined. At birth, calves were weighed and height, length, thoracic circumference, and ocular orbit and bi-parietal diameters were measured. There were no differences (P > 0.05) in fetal development. The G1 cows had a longer gestation period (4.5 days; P<0.05) and their calves had greater (P<0.05) weight, height, length, and thoracic circumference at birth. In conclusion, Nellore females raised under intensive pasture management conditions, had significantly shorter gestation and smaller calves at birth than those raised under extensive pasture management conditions. Therefore, adoption of new management practices (e.g. intensive pasture management), should take into consideration animal behavior and productivity.
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Affiliation(s)
- M A C M Bergamaschi
- Department of Veterinary Medicine, Universidade Estadual Paulista (UNESP), Câmpus de Jaboticabal, Rua Sete de Setembro, 2875 São Carlos, SP 13560-181, Brazil.
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Abstract
Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie), appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc) and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction.
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Affiliation(s)
- V R Martins
- Centro de Tratamento e Pesquisa, Hospital do Câncer, Universidade de São Paulo, São Paulo, SP, Brasil
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