Biomedical subjects

Carlos Graeff-Teixeira

Publications and source records attributed to Carlos Graeff-Teixeira.

12 recordsLinked to original sources

PubMed2006

Phenantroline, lovastatin, and mebendazole do not inhibit oviposition in the murine experimental infection with Angiostrongylus costaricensis.

Abdominal angiostrongyliasis is a zoonotic infection produced by a metastrongylid intra-arterial nematode, Angiostrongylus costaricensis. Human accidental infection may result in abdominal lesions. The presence of the eggs in the tissues plays an essential role in morbidity of abdominal angiostrongyliasis. The objective of this study is to evaluate and compare the effects of lovastatin, phenanthrolin, and mebendazole on oviposition of A. costaricensis in a murine experimental model. Each group of 12 male Swiss mice (Mus musculus) was orally infected with 10 L3 of the "Santa Rosa" strain of A. costaricensis. Two control groups were established: (1) mice were infected and not treated; (2) noninfected and nontreated animals. The experimental groups received (1) lovastatin TL), at a daily dose of 250 mg/kg for 10 consecutive days 16 days after infection; (2) phenanthroline at a daily dose of 20 mg/kg for 5 consecutive days 21 days after infection; and (3) mebendazole at a daily dose of 5 mg/kg for 5 consecutive days 21 days after infection. There was no significant inhibition of oviposition for lovastatin- and mebendazole-treated animals, whereas phenanthroline was associated with the lowest averages of larviposition per postinfection day and significant reduction of mortality.

Angiostrongylus↗

PubMed2005

Longitudinal clinical and serological survey of abdominal angiostrongyliasis in Guaporé, southern Brazil, from 1995 to 1999.

Abdominal angiostrongyliasis is a zoonotic infection caused by Angiostrongylus costaricensis, a nematode with an intra-vascular location in the mesentery. Our objective was to address several aspects of the natural history of this parasitosis, in a longitudinal clinical and seroepidemiological study. A total of 179 individuals living in a rural area with active transmission in southern Brazil were followed for five years (1995-1999) resulting in yearly prevalence of 28.2%, 4.2%, 10%, 20.2% and 2.8% and incidences of 0%, 5.9%, 8% and 1.5%, respectively. Both men and woman were affected with higher frequencies at age 30-49 years. In 32 individuals serum samples were collected at all time points and IgG antibody reactivity detected by ELISA was variable and usually persisting not longer than one year. Some individual antibody patterns were suggestive of re-infection. There was no association with occurrence of abdominal pain or of other enteroparasites and there was no individual with a confirmed (histopathologic) diagnosis. Mollusks were found with infective third-stage larvae in some houses with an overall prevalence of 16% and a low parasitic burden. In conclusion, abdominal angiostrongyliasis in southern Brazil may be a frequent infection with low morbidity and a gradually decreasing serological reactivity.

Adolescent↗

PubMed2005

In vitro maintenance of Angiostrongylus costaricensis does not provide physiological conditions for egg laying.

Fifteen pairs (male/female) of Angiostrongylus costaricensis were kept in vitro in Waymouth medium for three days to evaluate the amount and duration of egg laying. At 24, 48 and 72 hours, the mean egg counts were 321, 24 and 4 eggs/10 microliters, respectively. Most of the eggs were eliminated within the first 24 hours, suggesting they are expelled under non-physiological conditions. These results indicate that in vitro conditions are not appropriate for drug trials of egg-laying inhibitors for treatment of abdominal angiostrongylosis.

Angiostrongylus↗

PubMed2004

The initial epidemiological studies in the low endemicity schistosomiasis area in Esteio, Rio Grande do Sul, the southernmost Brazilian state, 1997 to 2000.

Nor Biomphalaria glabrata neither Schistosoma mansoni were reported from Rio Grande do Sul, the southernmost Brazilian state before 1997. Their detection next to the Sinos River, Esteio, confirmed predictions of schistosomiasis expansion to the south. Parasitological examinations both in snails and fecal samples from the human population were performed from 1997 to 2000. The last 3 out of 5 surveys were performed after a preliminar serological screening procedure in a risk group identified at a population census. A total of 11 infected individuals were found infected and snails from 2 different sites were positive for S. mansoni. Samples from these 2 and other sites were identified as B. glabrata. Egg counts in feces were below 1 per gram in 6 out of 11 patients. Some socio-cultural perceptions of water contact activities next to the Sinos River may cause difficulties to control efforts, but they also may be partially acting against a very rapid increase in transmission intensity. The southernmost schistomiasis mansoni foci in Americas rise the alert for its ongoing expansion.

Adolescent↗

PubMed2004

Treatment with mebendazole is not associated with distal migration of adult Angiostrongylus costaricensis in the murine experimental infection.

Abdominal angiostrongyliasis is a zoonotic infection produced by a metastrongylid intra-arterial nematode, Angiostrongylus costaricensis. Human accidental infection may result in abdominal lesions and treatment with anti-helminthics is contra-indicated because of potential higher morbidity with excitement or death of worms inside vessels. To evaluate the effect of mebendazole on localization of the worms, male Swiss mice, 5 week-old, were infected with 10 third stage larvae per animal. Twelve infected mice were treated with oral mebendazol, at 5 mg/kg/day, for 5 consecutive days, begining 22 days after inoculation. As control groups, 12 infected but non-treated mice and other 12 non-infected and non-treated mice were studied. The findings at necropsy were, respectively for the treated (T) and control (C) groups: 92% and 80% of the worms were inside the cecal mesenteric arterial branch; 8% and 10% were located inside the aorta. Only in the group C some worms (10%) were found inside the portal vein or splenic artery. These data indicate that treatment with mebendazole does not lead to distal or ectopic migration of A. costaricensis worms.

Angiostrongylus cantonensis↗

PubMed2004

Molecular differentiation of Angiostrongylus costaricensis, A. cantonensis, and A. vasorum by polymerase chain reaction-restriction fragment length polymorphism.

Angiostrongylus cantonensis, A. costaricensis, and A. vasorum are etiologic agents of human parasitic diseases. Their identification, at present, is only possible by examining the adult worm after a 40-day period following infection of vertebrate hosts with the third-stage larvae. In order to obtain a diagnostic tool to differentiate larvae and adult worm from the three referred species, polymerase chain reaction-restriction fragment length polymorphism was carried out. The rDNA second internal transcribed spacer (ITS2) and mtDNA cytochrome oxidase I regions were amplified, followed by digestion of fragments with the restriction enzymes RsaI, HapII, AluI, HaeIII, DdeI and ClaI. The enzymes RsaI and ClaI exhibited the most discriminating profiles for the differentiation of the regions COI of mtDNA and ITS2 of rDNA respectively. The methodology using such regions proved to be efficient for the specific differentiation of the three species of Angiostrongylus under study.

Angiostrongylus↗

PubMed2003

Drug trials for treatment of human angiostrongyliasis.

Abdominal and cerebral angiostrongyliasis are two important infections produced by metastrongylid worms, the former occurring in Central and South America and the later in Asia and Pacific Islands. Drug treatment is a challenge since the worms and its evolving larvae live or migrate inside vessels and efficient killing of the parasites may produce more severe lesions. Larvicidal effect of certain drugs appears to be more easily accomplished but this outcome is not useful in abdominal angiostrongyliasis since clinical manifestations appear to result from sexual maturation of the worms. We review the drug trials in murine experimental models and conclude that most of them could not be considered good candidates for treatment of human infection, except for PF1022A, pyrantel and flubendazole.

Angiostrongylus↗

PubMed2003

[Eggs and reproductive organs of female Angiostrongylus costaricensis are more intensely recognized by human sera from acute phase in abdominal angiostrongyliasis].

Angiostrongylus costaricensisis is an intra-arterial nematode of rodents. Man may become accidentally infected through ingestion of contaminated food or water. Our objective was to describe the parasite structures recognized by human antibodies in serum samples from acute and convalescent phases of abdominal angiostrongyliasis. An indirect immunofluorescent method was employed to study reactivity on whole eggs and sections of female worms and first stage larvae (L1). L1 were also studied before and after sonication. Fluorescence, always higher with acute phase sera, was detected on the surface of whole eggs and in L1 fragments and was neither present on whole L1 nor on their sections. An inespecific reactivity was seen on the cuticular border of the general cavity and reproductive organs. The data indicate the latter as a main source of antigenicity.

Acute Disease↗

PubMedDate not supplied

Natural infection of deroceras laeve (Mollusca: gastropoda) with metastronbylid larvae in a transmission focus of abdominal angiostrongyliasis.

Angiostrongylus costaricensis is a nematode parasitic of rodents. Man may become infected by ingestion of the third stage larvae produced within the intermediate hosts, usually slugs from the family Veronicellidae. An epidemiological study carried out in a locality in southern Brazil (western Santa Catarina State) where these slugs are a crop pest and an important vector for A. costaricensis has documented for the first time the natural infection of Deroceras laeve with metastrongylid larvae. This small limacid slug is frequently found amid the folds of vegetable leaves and may be inadvertently ingested. Therefore D. laeve may have an important role in transmission of A. costaricensis to man.

Animals↗

PubMedDate not supplied

Dogs may be a reservoir host for Angiostrongylus costaricensis.

Angiostrongylus costaricensis is a parasitic nematode of wild rodents. Several other vertebrate species including man may become infected by ingestion of the third stage larvae produced by the intermediate hosts, usually slugs from the family Veronicellidae. There is a report of the diagnosis of abdominal angiostrongyliasis in Canis familiaris with lesions resembling those found in human disease. As a preliminar evaluation of the adequacy of a canine model for pathogenetic studies, a dog was inoculated with 75 L3 of A. costaricensis. Infection was established and fist stage larvae were found in feces up to 88 days post infection, sometimes in very large numbers (9.5 x 10(4) L1/g). No clinical manifestations or significant lesions were detected. These are indications that dog may play a role as a reservoir host for A. costaricensis.

Angiostrongylus↗

PubMedDate not supplied

Diagnosis of abdominal angiostrongyliasis by PCR from sera of patients.

Abdominal angiostrongyliasis is a zoonotic infection caused by an intra-vascular nematode parasitic of wild rodents, Angiostrongylus costaricensis. No parasitological diagnosis is currently available and immunodiagnosis presents several drawbacks. Primers constructed based on a congeneric species, A. cantonensis, were able to amplify a 232 bp fragment from serum samples of 3 patients with histopathological diagnosis. Extraction was better performed with DNAzol and the specificity of the primers was confirmed by Southern blot. This disease has been diagnosed with frequency in south of Brazil, thus, this method appears like the important and unpublished alternative to improve diagnostic of disease.

Angiostrongylus↗

PubMedDate not supplied

Abdominal angiostrongyliasis: a case with severe evolution.

A case of acute abdomen disease caused by abdominal angiostrongyliasis is reported. A 42-year-old otherwise healthy patient presented with a complaint of nine days of abdominal pain, constipation, disury, fever and right iliac fossa palpable mass. Exploratory laparotomy was performed. After surgical treatment the patient presented serious complications.

Abdomen, Acute↗