Mauricio Horta - Academia.edu (original) (raw)

Papers by Mauricio Horta

Acta Paediatrica, 2010

References 1. Finlay JL, Zacharoulis S. The treatment of high grade gliomas and diffuse intrinsic... more References 1. Finlay JL, Zacharoulis S. The treatment of high grade gliomas and diffuse intrinsic pontine tumors of childhood and adolescence: a historical -and futuristic -perspective. J Neurooncol 2005; 75: 253-66.

Tumor papilar sólido-cístico do pâncreas: aspectos clínico-radiológicos e resultados cirúrgicos e... more Tumor papilar sólido-cístico do pâncreas: aspectos clínico-radiológicos e resultados cirúrgicos em cinco pacientes operados ARTIGO ORIGInAl RESUMO Objetivo: Descrever cinco casos de tumor papilar-cístico do pâncreas considerando os achados clínicos e radiológicos e o tratamento cirúrgico. Métodos: Os autores apresentam cinco pacientes portadores de tumores sólido-císticos do pâncreas. Todos os pacientes foram tratados no Serviço de Cirurgia Geral do Hospital-Escola da Faculdade de Medicina do ABC, Santo André, São Paulo. Quatro pacientes eram do sexo feminino e um do sexo masculino. A idade variou de 15 a 36 anos. O período de estudo foi de janeiro de 2000 a novembro de 2006. Os principais aspectos relativos aos achados clínicos, epidemiológicos e radiológicos foram estudados. Resultados: Todos os tumores eram ressecáveis. Os seguintes procedimentos cirúrgicos foram adotados: duas gastroduodenopancreatectomias cefálicas, uma pancreatectomia subtotal mais esplenectomia, uma pancreatectomia distal mais esplenectomia e uma gastroduodenopancreatectomia mais esplenectomia. Não houve óbitos. A morbidade pós-operatória foi de 20%. Todos os pacientes sobreviveram à retirada do tumor. Não houve recorrência (o período de seguimento variou de 6 a 54 meses). Conclusão: Os tumores papilares sólido-císticos do pâncreas são tumores que têm bom prognóstico. Os achados clínico-epidemiológicos e radiológicos são importantes para um diagnóstico correto.

Arquivos De Gastroenterologia, 2008

BACKGROUND: Despite its rarity, gallbladder cancer is an aggressive type of neoplasia with a very... more BACKGROUND: Despite its rarity, gallbladder cancer is an aggressive type of neoplasia with a very poor prognosis. The best resection for oncological purposes continues to be right hepatectomy extended to segment IV. However, bisegmentectomy IV-V is becoming an interesting alternative because of greater preservation of the parenchyma. AIM: To report the early and late results from bisegmentectomy IV-V in cases of carcinoma of the gallbladder. METHODS: A series of seven cases of invasive carcinoma is presented (six women and one man). These patients underwent bisegmentectomy IV-V at the General Surgery Service of the Teaching Hospital of the ABC Medical School, Santo André, SP, Brazil. The study was conducted between 2002 and 2006. The patients ages ranged from 52 to 72 years. The diagnosis was preoperative (radiological) in five cases, which were all confirmed by intraoperative frozen-tissue examination, while in two cases the diagnosis was postoperative, following open cholecystectomy. RESULTS: The duration of the operation ranged from 180 to 340 minutes. The quantity of intraoperative bleeding ranged from 200 to 1500 mL. There were two major complications but no mortality. Six patients did not present any recurrence over the course of 3 to 30 months of follow-up. CONCLUSION: Bisegmentectomy IV-V may constitute a curative surgical alternative for treating gallbladder cancer. This procedure presents acceptable morbidity and mortality.

Pediatric Neurology, 2009

We report a case of acute disseminated encephalomyelitis after infection by the spirochete Leptos... more We report a case of acute disseminated encephalomyelitis after infection by the spirochete Leptospira interrogans and review the few cases of acute disseminated encephalomyelitis and central nervous system disorders described in literature. The high prevalence of leptospirosis in developing countries and the possibility of acute disseminated encephalomyelitis, per se, highlights the importance of complete investigation for diagnosis and early treatment, leading to a better prognosis with reduction of morbidity and mortality rates.

Veterinary Parasitology, 2011

Acta Scientiarum. Biological Sciences, 2009

Veterinary Parasitology, 2009

Memorias Do Instituto Oswaldo Cruz, 2007

This study investigated rickettsial infection in animals, humans, ticks, and fleas collected in f... more This study investigated rickettsial infection in animals, humans, ticks, and fleas collected in five areas of the state of São Paulo. Eight flea species (Adoratopsylla antiquorum antiquorum, Ctenocephalides felis felis, Polygenis atopus, Polygenis rimatus, Polygenis roberti roberti, Polygenis tripus, Rhopalopsyllus lugubris, and Rhopalopsyllus lutzi lutzi), and five tick species (Amblyomma aureolatum, Amblyomma cajennense, Amblyomma dubitatum, Ixodes loricatus, and Rhipicephalus sanguineus) were collected from dogs, cats, and opossums. Rickettsia felis was the only rickettsia found infecting fleas, whereas Rickettsia bellii was the only agent infecting ticks, but no animal or human blood was shown to contain rickettsial DNA. Testing animal and human sera by indirect immunofluorescence assay against four rickettsia antigens (R. rickettsii, R. parkeri, R. felis, and R. bellii), some opossum, dog, horse, and human sera reacted to R. rickettsii with titers at least four-fold higher than to the other three rickettsial antigens. These sera were considered to have a predominant antibody response to R. rickettsii. Using the same criteria, opossum, dog, and horse sera showed predominant antibody response to R. parkeri or a very closely related genotype. Our serological results suggest that both R. rickettsii and R. parkeri infected animals and/or humans in the studied areas.

In serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three... more In serum samples obtained from all the healthy humans, horses, dogs, and donkeys present on three farms in the Pedreira Municipality, an endemic area for Brazilian spotted fever, an indirect immunofluorescence assay (IFA) detected antibodies against Rickettsia rickettsii in 17 (77.3%) horses, 5 (31.3%) dogs (titers ranging from 64 to 4,048), and none of 4 donkeys or 50 humans. Five canine and eight equine sera with high antibody titers to R. rickettsii were also tested by IFA against R. bellii, R. akari, and R. africae antigens. Sera from two horses and two dogs that showed similar high antibody titers against two rickettsial antigens were evaluated after cross-absorption. Sera from seven horses and two dogs contained antibodies specific for R. rickettsii, and one dog serum had antibodies against a Rickettsia species very closely related to R. africae. The latter may have been caused by infection with the recently identified COOPERI strain.

Journal of Clinical Microbiology, 2004

Owing to the potential role of the tick Amblyomma cooperi in the enzootic cycle of Rickettsia ric... more Owing to the potential role of the tick Amblyomma cooperi in the enzootic cycle of Rickettsia rickettsii, the etiologic agent of Brazilian spotted fever (BSF), this study evaluated infection by Rickettsia species in A. cooperi ticks collected from an area in Brazil where BSF is endemic. Among a total of 40 A. cooperi adult ticks collected in an area of BSF endemicity in the state of São Paulo, PCR analysis detected DNA of Rickettsia bellii in 16 ticks (40%), and 3 other ticks (7.5%) were positive for a previously unidentified spotted-fever-group (SFG) rickettsia. Cultivation in Vero cell cultures by the shell vial technique with individual A. cooperi ticks resulted in two isolates of R. bellii and one isolate genotypically characterized as an SFG rickettsia. The two R. bellii isolates were established in Vero cell cultures in the laboratory and were confirmed to be R. bellii by molecular analysis of the gltA and 17-kDa protein-encoding genes and by electron microscopic analysis. The SFG rickettsial isolate could not be stably passaged in cell culture in the laboratory, but molecular analysis of early passages suggested that it was closely related to Rickettsia parkeri, Rickettsia africae, and Rickettsia sibirica. These results do not support the role of A. cooperi in the ecology of R. rickettsii in the area studied, but they add two more species of rickettsiae to the poorly developed list of species occurring in ticks in South America.

Revista Do Instituto De Medicina Tropical De Sao Paulo, 2008

The present study investigated the infection by spotted fever rickettsia in an endemic area for B... more The present study investigated the infection by spotted fever rickettsia in an endemic area for Brazilian spotted fever (BSF; caused by Rickettsia rickettsii) in Minas Gerais State, Brazil. Human, canine and equine sera samples, and Amblyomma cajennense adult ticks collected in a rural area of Itabira City, Minas Gerais State were tested for rickettsial infection. Through Immunofluorescence Assay (IFA) we demonstrated the presence of antibodies anti-R. rickettsii in 8.2%, 81.3% and 100% of the human, canine and equine sera, respectively. None of the 356 tick specimens analyzed were positive for Rickettsia by the hemolymph test or Polymerase Chain Reaction technique (PCR) for the htrA and the gltA genes. Our serological results on horses and dogs (sentinels for BSF) appoint for the circulation of a SFG Rickettsia in the study area, however in a very low infection rate among the A. cajennense tick population. VIANNA, M.C.B.; HORTA, M.C.; SANGIONI, L.A.; CORTEZ, A.; SOARES, R.M.; MAFRA, C.L.; GALVÃO, M.A.M.; LABRUNA, M.B. & GENNARI, S.M. -Rickettsial spotted fever in Capoeirão village, Itabira, Minas Gerais, Brazil. Rev. Inst. Med. trop. S. Paulo, 50(5): 297-301, 2008.

Cadernos De Saude Publica, 2008

The present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area f... more The present study provides a rickettsial serosurvey in 25 dogs and 35 humans in an endemic area for Brazilian spotted fever in the State of São Paulo, where the tick Amblyomma aureolatum is the main vector. Testing canine and human sera by indirect immunofluorescence against four Rickettsia antigens (R. rickettsii, R. parkeri, R. felis and R. bellii) showed that 16 (64%) of canine sera and 1 (2.8%) of human sera reacted to at least one of these rickettsial antigens with titers ³ 64. Seven canine sera and the single reactive human serum showed titers to R. rickettsii at least four times those of any of the other three antigens. The antibody titers in these 7 animals and 1 human were attributed to stimulation by R. rickettsii infection. No positive canine or human serum was attributed to stimulation by R. parkeri, R. felis, or R. bellii. Our serological results showed that dogs are important sentinels for the presence of R. rickettsii in areas where the tick A. aureolatum is the main vector of Brazilian spotted fever.

Experimental and Applied Acarology, 2002

Biological data of three generations of Amblyomma tigrinum in the laboratory are reported and the... more Biological data of three generations of Amblyomma tigrinum in the laboratory are reported and the suitability of different host species for immature ticks are compared. Grouping the three generations, infestations by both the larval and nymphal stages were performed on chickens (Gallus gallus), wistar rats (Rattus norvegicus), rabbits (Oryctolagus cuniculus),wild mice (Calomys callosus), dogs (Canis familiaris) and opossums (Didelphis albiventris). Only dogs were used for infestations by adult ticks. Tick developmental periods were observed in an incubator at 27°C and RH 90%. The proportion of engorged larvae recovered from chickens (21.7% of the exposed larvae) was significantly larger (pppC. callosus, which showed significantly longer (pth feeding day, followed by the 6th day, on all hosts except for C. callosus. Larval premolt periods were similar for engorged ticks exposed to different host species, except for larvae fed on dogs, which showed significantly longer (pth feeding day on chickens. Although nymphal detachment on rats peaked on the 8th day, only 15 nymphs were recovered from this host species. In a sample of 144 F3 nymphs fed on chickens no significant difference (p>0.10) was found between the feeding or premolt periods of 82 males and 62 females, but female nymphs were significantly heavier (pA. tigrinum, which is consistent with, several reports of adult A. tigrinum ticks parasitizing dogs in different areas of South America. Our results reinforce that in these same areas avian species are the major hosts for immature stages of this tick species.

Applied and Environmental Microbiology, 2006

We report the isolation and establishment of Rickettsia felis in the C6/36 cell line. Rickettsial... more We report the isolation and establishment of Rickettsia felis in the C6/36 cell line. Rickettsial growth was intense, always with 90 to 100% of cells being infected after few weeks. The rickettsial isolate was confirmed by testing infected cells by PCR and sequencing fragments of three major Rickettsia genes (gltA, ompB, and the 17-kDa protein gene).

Ticks and Tick-borne Diseases

Sera of 320 dogs from urban and rural areas of a Pantanal region of Brazil were evaluated for ric... more Sera of 320 dogs from urban and rural areas of a Pantanal region of Brazil were evaluated for rickettsial (Rickettsia rickettsii, R. parkeri, R. amblyommii, R. rhipicephali, R. felis, and R. bellii) and ehrlichial (Ehrlichia canis) infection by the immunofluorescence assay (IFA). Risk factors for ehrlichiosis or rickettsiosis were also evaluated. Positive reaction against Ehrlichia spp. was detected in 227 (70.9%) dogs, 119 (74.3%) from an urban area and 108 (67.5%) from rural areas (P > 0.05). For Rickettsia spp., 152 (47.5%) dogs were positive, 31 (19.3%) from urban and 121 (75.6%) from rural areas (P < 0.05). Highest anti-Rickettsia spp. endpoint titers were observed for R. amblyommii, suggesting homologous reactions to this agent or a very closely related organism. While most of the urban dogs were found parasitized by the tick Rhipicephalus sanguineus, infestations on rural dogs were predominated by Amblyomma cajenennse. Rickettsial infection was significantly higher (P < 0.05) in rural dogs, in dogs with hunting practice, or in A. cajennense-infested dogs.

Annals of The New York Academy of Sciences, 2006

Abstract: An Ixodes loricatus engorged female, infected with Rickettsia bellii, was collected fro... more Abstract: An Ixodes loricatus engorged female, infected with Rickettsia bellii, was collected from an opossum (Didelphis aurita) in Mogi das Cruzes, São Paulo State, Brazil. Two consecutive laboratory tick generations (F1 and F2) reared from this single engorged female were evaluated for Rickettsia infection by polymerase chain reaction (PCR) targeting specific Rickettsia genes. Immature ticks fed on naïve Wistar rats (Rattus norvegicus) and adult ticks fed on opossum (D. aurita), both free of ticks and rickettsial infection. PCR performed on individual ticks from the F1 (20 larvae, 10 nymphs, and 10 adults) and the F2 (30 larvae, 30 nymphs, and 15 adults) yielded expected bands compatible with Rickettsia. All the PCR products that were sequenced, targeting gltA gene, resulted in sequences identical to each other and 99.7% (349/350) similar to the corresponding sequence of R. bellii in GenBank. The R. bellii infection on ticks from the second laboratory generation (F2) was confirmed by other PCR protocols and successful isolation of R. bellii in cell culture. We report for the first time a Rickettsia species infecting I. loricatus, and the first report of R. bellii in the tick genus Ixodes. We conclude that there was an efficient transovarial transmission and transstadial survival of this Rickettsia species in the tick I. loricatus. Our results suggest that R. bellii might be maintained in nature solely by transovarial transmission and transstadial survival in ticks (no amplifier vertebrate host is needed), since there has been no direct or indirect evidence of infection of vertebrate hosts by R. bellii.

Journal of Feline Medicine and Surgery, 2009

Rickettsia species antibodies have been detected in some cats but it is unknown whether infected ... more Rickettsia species antibodies have been detected in some cats but it is unknown whether infected cats develop clinical signs. The prevalence of Rickettsia species deoxyribonucleic acid (DNA) in blood from clinically ill cats has not been determined. The objective of this study was to determine if cats with fever (body temperature !102.5 F [39.2 C]) were more likely to have evidence of rickettsial infection than healthy, age-matched, control cats with a body temperature < 102.5 F. Rickettsia species polymerase chain reaction (PCR) assays were performed to detect rickettsial DNA extracted from blood (71 paired samples), indirect immunofluorescence assays (IFA) were performed to detect serum antibodies against Rickettsia felis (90 paired samples) and Rickettsia rickettsii (91 paired samples), and the results between pairs were compared. All samples were negative for Rickettsia species DNA. More cats with fever were seropositive for R felis or R rickettsii than control cats, but results were not statistically significant. Results of this pilot study failed to show an association between Rickettsia species DNA or Rickettsia species antibodies and fever.

Arquivo Brasileiro De Medicina Veterinaria E Zootecnia, 2005

Samples of 10 and 14 Ctenocephalides felis felis fleas were collected on dogs from Pedreira and M... more Samples of 10 and 14 Ctenocephalides felis felis fleas were collected on dogs from Pedreira and Mogi das Cruzes municipalities, respectively, in the State of São Paulo, Brazil, for detection of Rickettsia spp. Individual fleas were submitted to Polymerase Chain Reaction targeting the 17-kDa and the 190-kDa (OmpA) genes of Rickettsiae. This later gene is specific for spotted fever group. Nine fleas from Pedreira (90%) and four fleas from Mogi das Cruzes (28%) were positive for the 17-kDa gene, and eight fleas from Pedreira (80%) and four from Mogi das Cruzes (28%) were positive for 190-kDa gene. The nucleotide sequence of the 190-kDa products of one flea from Pedreira and one flea from Mogi das Cruzes were 100% identical to each other, and when compared to the GenBank Data, they were 100% identical to the 190-kDa sequence of R. felis. This was the first report of its occurrence in the State of São Paulo.

Vector-borne and Zoonotic Diseases, 2007

The current study evaluated the prevalence of Ehrlichia canis Donatien and Lestoquard in domestic... more The current study evaluated the prevalence of Ehrlichia canis Donatien and Lestoquard in domestic dogs, Canis familiaris L., and Rhipicephalus sanguineus (Latreille) (Acari: Ixodidae) ticks from different areas of Brazil. In Monte Negro County (state of Rondô nia, Brazilian western Amazon), the indirect immunoßuorescence assay detected E. canis-reactive antibodies (titer Ն40) in 58/153 (37.9%) and 40/161 (24.8%) dogs from the urban and rural areas, respectively. These values were signiÞcantly different between the two areas. Ticks from a household in the urban area of Monte Negro, and from households in three other localities (162Ð165 adult ticks per household) in the state of São Paulo (SP) were tested by polymerase chain reaction (PCR) targeting an erlichial dsb gene fragment. The prevalence of infected ticks (given as minimal infection rate) was 2.3, 6.2, and 3.7% for populations 1 (Monte Negro), 2 (Jundiaṍ, SP), and 3 (São Paulo I, SP), respectively, which were statistically similar. In contrast, no infected tick was detected in population 4 (São Paulo II, SP). DNA sequences were determined for some of the PCR products generated from ticks and dogs from populations 1Ð3, being all identical to each other and to available sequences of E. canis in GenBank. These results reinforce previous records of E. canis-infecting dogs in Brazil. Natural infection of R. sanguineus ticks by E. canis is reported for the Þrst time in Brazil, where this tick is the commonest species infesting dogs.