Metacercariae of Heterodiplostomum lanceolatum (Trematoda: Proterodiplostomidae) found in Leptodactylus podicipinus (Anura: Leptodactylidae) from Brazil: a morphological, molecular and ecological study.

The trematodes from South American reptiles are poorly known, with only one life cycle completely characterized. We used molecular and morphological methods to characterize diplostomoid metacercariae found in 29 of 86 pointedbelly frogs, Leptodactylus podicipinus (Cope, 1862) collected in a marsh pond in Selvíria, in the central-west region of Brazil. The metacercariae were identified as Heterodiplostomum lanceolatum Dubois, 1936 (Proterodiplostomidae), a rarely reported species that matures in snakes. In phylogenetic analysis of partial sequences from 28S rDNA, H. lanceolatum fell within a polytomy with the proterodiplostomid Crocodilicola pseudostoma (molecular divergence of 4.1%) and other members of the superfamily Diplostomoidea. Our collections provide insights into the ecology of this parasite, in that infected frogs were smaller than uninfected frogs, and metacercariae were more numerous in the abdominal cavity and hindlimb muscles than in abdominal muscles, which suggests directions for future research on the transmission and pathology of this proterodiplostomid.

Link Between the Adult and the Metacercaria of Clinostomum heluans Braun, 1899 (Trematoda: Clinostomidae) Through DNA Sequences, and its Phylogenetic Position Within the Genus Clinostomum Leidy, 1856.

The phylogenetic position of Clinostomum heluans Braun, 1899 within the genus Clinostomum Leidy, 1856 is reported in this study based on sequences of the barcoding region of the mitochondrial cytochrome c oxidase subunit 1 gene ( COX1). Additionally, molecular data are used to link the adult and the metacercariae of the species. The metacercariae of C. heluans were found encysted infecting the cichlid fish Australoheros sp. in Minas Gerais, Brazil, whereas the adults were obtained from the mouth cavity of the Great White Egret, Ardea alba, in Campeche, Mexico. The COX1 sequences obtained for the Mexican clinostomes and the Brazilian metacercaria were almost identical (0.2% molecular divergence), indicating conspecificity. Similar molecular divergence (0.2-0.4%) was found between sequences of C. heluans reported here and Clinostomum sp. 6 previously obtained from a metacercaria recovered from the cichlid Cichlasoma boliviense in Santa Cruz, Bolivia. Both maximum likelihood and Bayesian inference analyses unequivocally showed the conspecificity between C. heluans and Clinostomum sp. 6, which form a monophyletic clade with high nodal support and very low genetic divergence. Moreover, tree topology reveals that C. heluans occupies a basal position with respect to New World species of Clinostomum, although a denser taxon sampling of species within the genus is further required. The metacercaria of C. heluans seems to be specific to cichlid fish because both samples from South America were recovered from species of this fish family, although not closely related.

Psittacara leucophthalmus (Aves: Psittacidae) como um novo hospedeiro de Paratanaisia bragai (Trematoda: Eucotylidae) no Brasil: achados clínicos e patológicos: relato de caso / Psittacara leucophthalmus as a new host of Paratanaisia bragai (Trematoda: Eucotylidae) in Brazil: clinical and pathological findings: case report

Paratanaisia bragai é um trematódeo que parasita rins e ureteres de aves domésticas e selvagens. Apesar de considerado pouco patogênico pode levar a complicações clínicas e morte em infecções severas. No presente estudo, um caso de parasitismo fatal em maritaca (Psittacara leucophthalmus) por P. bragai é relatado. A ave, oriunda da área urbana do município de Lavras, Minas Gerais, Brasil, teve manifestações clínicas de apatia, desidratação, dispneia e veio a óbito. Na necropsia foram observados rins aumentados de volume, pálidos, com superfície irregular e nodulações esbranquiçadas. Ao corte verificaram-se parasitos nos rins, que foram processados para montagem de lâminas permanentes e identificados segundo técnica de rotina como P. bragai. No exame histopatológico dos rins foram constatados infiltrado inflamatório linfoplasmocítico multifocal moderado, dilatação de túbulos e focos de regeneração tubular, associados a fibrose intersticial moderada no córtex renal. Na medula renal havia infiltrado de macrófagos, heterófilos, eosinófilos e células gigantes multinucleadas associado a parasitos em ductos coletores dilatados. O parasitismo de P. leucophthalmus por P. bragai é relatado pela primeira vez. A importância de se considerar este parasito entre as possibilidades diagnósticas em aves com insuficiência renal é brevemente discutida.(AU)

Paratanaisia bragai is a trematode parasite of the kidneys and ureters of poultry and wild birds. Despite its low pathogenicity, this parasite can lead to several clinical complications and death in heavy infections. In the present study, a fatal case of parasitism by P. bragai in a specimen of the White-eyed Parakeet, Psittacara leucophthalmus, is reported. The bird, coming from the urban area of the county of Lavras, Minas Gerais, Brazil, was clinically evaluated and revealed apathy, dehydration, dyspnea, and death. The gross findings were pale and enlarged kidneys, which also had irregular surface with whitish nodulations. Parasites were observed on cutting surface of the renal parenchyma. They were processed for assembly of permanent slides and identified as P. bragai according to routine technique. The histologic findings were mild multifocal lymphoplasmacytic infiltrate, tubular dilatation and foci of tubular regeneration related to mild interstitial fibrosis in the renal cortex, and infiltration of macrophages, heterophils, eosinophils and multinucleated giant cells associated with metazoan parasites in the collecting ducts in renal medulla. The parasitism of P. leucophthalmus by P. bragai is reported for the first time. The importance of considering this parasite among the diagnostic possibilities in birds with renal insufficiency is briefly discussed.(AU)

Centrocestus formosanus (Trematoda: Heterophyidae) in Melanoides tuberculata (Gastropoda: Thiaridae) from Vila do Abraão, Ilha Grande, Rio de Janeiro, Brazil / Centrocestus formosanus (Trematoda: Heterophyidae) em Melanoides tuberculata (Gastropoda, Thiaridae) da Vila do Abraão, Ilha Grande, Rio de Janeiro, Brasil

Abstract Pleurolophocercous cercariae found in the invasive gastropod Melanoides tuberculata (Müller, 1774) collected in a stream of the Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil were used for experimental infection that enabled the identification of the heterophyid trematode Centrocestus formosanus (Nishigori, 1924). The parasite has been found in the locality since 2007, after two years of the introduction of M. tuberculata. Recently, from a sample of 483 specimens collected in June 2013, 101 (21%) were found infected with parasite. The potential environmental impacts caused by the parasite occurrence could be underestimated in the country, and actions to monitor and control both the parasite and the mollusk are necessary.

Resumo Cercárias do tipo pleurolofocerca encontradas no gastrópode invasor Melanoides tuberculata (Müller, 1774) coletados em um riacho da Vila do Abraão em Ilha Grande, Angra dos Reis, Rio de Janeiro, Brasil foram utilizadas em estudos de infecção experimental que possibilitaram a identificação do trematódeo heterofiídeo Centrocestus formosanus (Nishigori, 1924). O parasito vem sendo encontrado na localidade desde 2007, dois anos após a introdução do molusco. Recentemente, de uma amostra de 483 espécimes coletados em junho de 2013, 101 (21%) apresentavam-se infectados pelo parasito. Os potenciais impactos ambientais ocasionados pela ocorrência deste parasito podem estar sendo subestimados no país, sendo necessárias ações visando o monitoramento e controle tanto do parasito quanto do molusco.

Centrocestus formosanus (Trematoda: Heterophyidae) in Melanoides tuberculata (Gastropoda: Thiaridae) from Vila do Abraão, Ilha Grande, Rio de Janeiro, Brazil.

Pleurolophocercous cercariae found in the invasive gastropod Melanoides tuberculata (Müller, 1774) collected in a stream of the Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro, Brazil were used for experimental infection that enabled the identification of the heterophyid trematode Centrocestus formosanus (Nishigori, 1924). The parasite has been found in the locality since 2007, after two years of the introduction of M. tuberculata. Recently, from a sample of 483 specimens collected in June 2013, 101 (21%) were found infected with parasite. The potential environmental impacts caused by the parasite occurrence could be underestimated in the country, and actions to monitor and control both the parasite and the mollusk are necessary.

Can the same species of Platynosomum (Trematoda: Dicrocoeliidae) infect both mammalian and avian hosts?

The importance of platynosomiasis has increased in feline veterinary practice, but aspects related to the specificity of Platynosomum spp. in definitive hosts requires further study. Although morphological traits suggest that the same species, P. illiciens, may infect both birds and mammals, the synonymies previously proposed have not been widely accepted, likely because host specificity is assumed. In addition, the name P. fastosum has frequently been used for parasites recovered from mammals. In the present study, metacercariae (n= 100/animal) of P. illiciens recovered from lizards (Hemidactylus mabouia) in Brazil were fed to Australian parakeets (Melopsittacus undulatus) and mice. Two parasites were recovered from the liver of one M. undulatus specimen during a necropsy that was performed 105 days after infection, and all mice were found to be infected with 37 ± 12 (18-48) parasites. The morphology of the P. illiciens obtained from the parakeet was similar to that of parasites obtained from mice and those described previously from naturally infected birds and mammals. Non-specificity of P. illiciens in hosts is discussed briefly, based on the parasitological and morphological results obtained during the avian experimental platynosomiasis and the epidemiology and geographical distribution of this parasite.

Experimental and molecular study of cercariae of Clinostomum sp. (Trematoda: Clinostomidae) from Biomphalaria spp. (Mollusca: Planorbidae) in Brazil.

Despite the large number of reports of species of Clinostomum from vertebrate hosts in South America, studies evaluating the molluscan transmitters of these parasites are scarce. In the present study, clinostomatoid cercariae shed from 0.02% (4/17,485) specimens of Biomphalaria spp., collected at the Pampulha reservoir, Belo Horizonte, Minas Gerais, Brazil, were used for experimental infection of Poecilia reticulata . Samples of cercariae from molluscs and metacercariae experimentally obtained from fish were subjected to morphological and molecular analyses and compared with species of Clinostomum reported in the Americas. The cercariae and metacercariae, here identified as Clinostomum sp., present general morphology similar to that reported for Clinostomum marginatum , however, from molecular point of view, differ significantly from North American C. marginatum and other species of Clinostomum reported in South America. These results suggest that the diversity of Clinostomum found in Brazil may be underestimated. Additional studies aimed at molecular characterization of South American species of Clinostomum, including the finding of specimens with sequences similar to that reported for C. marginatum in North America are required.

Biomphalaria straminea (Mollusca: Planorbidae) as an intermediate host of Ribeiroia sp. (Trematoda: Psilostomidae) in Brazil.

Species of Ribeiroia are trematode parasites of birds and mammals that have acquired notoriety since Ribeiroia ondatrae was identified as a cause of mortality and malformations in North American amphibians. Although species of Ribeiroia have been reported in vertebrate hosts in South America, the snails involved in its transmission remain unknown in Brazil. During malacological studies conducted at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and February 2012, in total 14,264 specimens of Biomphalaria straminea were collected, of which 192 (1.35%) were infected with gymnocephalous cercariae. The larvae were used for experimental infection of laboratory-reared guppies ( Poecilia reticulata ); metacercariae obtained in these fishes were orally administered to domestic ducks (Cairina moschata); and adult parasites were obtained from the proventriculus 10 days after infection. Based on morphological and molecular analyses, the parasite was identified as Ribeiroia sp., a species morphologically similar to R. ondatrae , but distinctly different at the molecular level. This is the first report of larvae of Ribeiroia in Brazil and B. straminea as a new intermediate host for this genus.

Biomphalaria straminea and Biomphalaria glabrata (Mollusca: Planorbidae) as new intermediate hosts of the fish eyefluke Austrodiplostomum compactum (Trematoda: Diplostomidae) in Brazil.

Austrodiplostomum compactum has been involved in cases of ocular diplostomiasis in several species of fish in Brazil, but the molluscan intermediate hosts of the parasite remain unknown. In the present study, malacological surveys were carried out at Pampulha Reservoir, Belo Horizonte, Minas Gerais, Brazil, between January 2009 and July 2012. A total of 16,119 specimens of Biomphalaria spp. were collected and examined, of which 68/14,948 specimens (0.45%) of Biomphalaria straminea and 6/541 (1.11%) of Biomphalaria glabrata were found harboring a strigeid cercariae. Groups of 5 specimens of Cyprinius carpio were experimentally infected with these cercariae (100 larvae/fish), and metacercariae were recovered from the eyes of the fish, 65 days after infection, with a mean intensity of infection of 10.4 (8-13) metacercariae/fish. Morphological study on cercariae and metacercariae identified them as A. compactum . This is the first record of cercariae of A. compactum in Brazil, and B. straminea and B. glabrata as new intermediate hosts for the parasite.

Melanoides tuberculata (Mollusca: Thiaridae) harboring renicolid cercariae (Trematoda: Renicolidae) in Brazil.

Melanoides tuberculata , naturally infected by gymnocephalous cercariae, were found in aquatic collections from Belo Horizonte, Minas Gerais, Brazil. After morphological characterization, larvae were used for experimental infection of Poecilia reticulata. Metacercariae were obtained from the liver of these fish, which were also found to be naturally infected in the same locality. The morphology and biology of the developmental stages of trematodes we obtained were characteristic of Renicola sp. This is the first record of renicolid cercariae and metacercariae in Brazil.

In vivo 1H MR spectroscopy of human head and neck lymph node metastasis and comparison with oxygen tension measurements.

BACKGROUND AND PURPOSE: Current diagnostic methods for head and neck metastasis are limited for monitoring recurrence and assessing oxygenation. 1H MR spectroscopy (1H MRS) provides a noninvasive means of determining the chemical composition of tissue and thus has a unique potential as a method for localizing and characterizing cancer. The purposes of this investigation were to measure 1H spectral intensities of total choline (Cho), creatine (Cr), and lactate (Lac) in vivo in human lymph node metastases of head and neck cancer for comparison with normal muscle tissue and to examine relationships between metabolite signal intensities and tissue oxygenation status. METHODS: Volume-localized Lac-edited MRS at 1.5 T was performed in vivo on the lymph node metastases of 14 patients whose conditions were untreated and who had primary occurrences of squamous cell carcinoma. MRS measurements were acquired also from the neck muscle tissue of six healthy volunteers and a subset of the patients. Peak areas of Cho, Cr, and Lac were calculated. Tissue oxygenation (pO2) within the abnormal lymph nodes was measured independently using an Eppendorf polarographic oxygen electrode. RESULTS: Cho:Cr ratios were significantly higher in the nodes than in muscle tissue (node Cho:Cr = 2.9 +/- 1.6, muscle Cho:Cr = 0.55 +/- 0.21, P = .0006). Lac was significantly higher in cancer tissue than in muscle (P = .01) and, in the nodes, showed a moderately negative correlation with median pO2 (r = -.76) over a range of approximately 0 to 30 mm Hg. Nodes with oxygenation values less than 10 mm Hg had approximately twice the Lac signal intensity as did nodes with oxygenation values greater than 10 mm Hg (P = .01). Cho signal intensity was not well correlated with pO2 (r = -.46) but seemed to decrease at higher oxygenation levels (>20 mm Hg). CONCLUSION: 1H MRS may be useful for differentiating metastatic head and neck cancer from normal muscular tissue and may allow for the possibility of assessing oxygenation. Potential clinical applications include the staging and monitoring of treatment.

Physician perspectives on increasing minorities in cancer clinical trials: an Eastern Cooperative Oncology Group (ECOG) Initiative.

PURPOSE: This paper describes the ECOG-NMA Minority Accrual Initiative to assure minority participation in cancer clinical trials. METHODS: Focus groups were held to identify physician-reported barriers to the enrollment of minority patients in Cleveland, OH, Indianapolis, IN, Santa Clara County, CA, and Philadelphia, PA. Community physicians affiliated with the National Medical Association (NMA), and Eastern Cooperative Oncology Group (ECOG) investigators participated in the focus groups. A four-step process consisting of focus group workshops were conducted to (i) identify barriers, (ii) develop potential solutions to the barriers, (iii) define solutions to barriers involving specific clinical trials, and (iv) implement the solutions. RESULTS: Focus group participants identified physician lack of information, patient fears and suspicion, the fear of losing patients, and distrust of the health care system as the major barriers to enrollment of African Americans. We found significant differences between community physicians and cancer program physicians in several areas. Community physicians emphasized personal contacts to address the lack of information and to overcome patient fears and suspicions, while the cancer program physicians emphasized printed materials. There was no difference by region in the barriers identified in the focus group workshops; however, the proposed solutions to overcoming the barriers were specific to each site. CONCLUSION: The four-step process developed by the ECOG and the NMA used the focus group methodology to identify and overcome barriers to participation of African Americans in cancer clinical trials. Outreach efforts to educate patients, their families, and community physicians about cancer clinical trials should be directed at overcoming patient suspicions and providing practical information to physicians about specific trials and how to enroll patients.

Tissue oxygen distribution in head and neck cancer patients.

BACKGROUND: The importance of hypoxia in limiting the sensitivity of tumor cells to ionizing radiation has long been known. METHODS: We evaluated the tissue oxygenation status with a polarographic needle electrode system in 37 patients with malignancies of the head and neck and correlated the pO2 of 25 patients with treatment outcome. RESULTS: Sixteen tumors contained areas of severe hypoxia, defined by pO2 values below 2.5 mm Hg. Tumor oxygenation parameters were not correlated with hemoglobin, age, and history of tobacco use. There were no subcutaneous PO2 values below 10 mm Hg (ie, no areas of moderate or severe hypoxia), whereas this degree of hypoxia was commonly found in the tumors. Though not statistically significant, hypoxic tumors showed trends for poorer treatment outcome. CONCLUSION: Our data demonstrate a great interindividual variability in the oxygenation of head and neck cancers and appears unassociated with clinical parameters. The method is capable of identifying patients with poorly oxygenated tumors, thereby providing important information for selecting patients who might need customized therapy designed to kill hypoxic tumor cells. Hypoxic tumors show a consistent trend for poor treatment outcome.

DNA damage measured by the comet assay in head and neck cancer patients treated with tirapazamine.

Tirapazamine (TPZ) [3-amino-1,2,4-benzotriazine 1,4-dioxide, SR4233, WIN 59075, and Tirazone] is a novel anticancer drug that is selectively activated by the low oxygen environment in solid tumors. By killing the radioresistant hypoxic cells, TPZ potentiates the antitumor efficacy of fractionated irradiation of transplanted tumors in mice. As this cell kill is closely correlated with TPZ-induced DNA damage, we investigated whether human head and neck cancers would show DNA damage similar to that seen in mouse tumors following TPZ administration. TPZ-induced DNA damage in both transplanted tumors in mice and in neck nodes of 13 patients with head and neck cancer was assessed using the alkaline comet assay on cells obtained from fine-needle aspirates. The oxygen levels of the patients' tumors were also measured using a polarographic oxygen electrode. Cells from the patients' tumors showed DNA damage immediately following TPZ administration that was comparable to, or greater than, that seen with transplanted mouse tumors. The heterogeneity of DNA damage in the patients' tumors was greater than that of individual mouse tumors and correlated with tumor hypoxia. The similarity of TPZ-induced DNA damage in human and rodent tumors suggests that tirapazamine should be effective when added to radiotherapy or to cisplatin-based chemotherapy in head and neck cancers.

Management of the clinically positive neck in organ preservation for advanced head and neck cancer.

BACKGROUND: To investigate clinicopathologic predictive criteria for the optimal management of neck metastases in patients with advanced head and neck cancers treated with combined chemoradiotherapy. METHODS: Prospective study, 48 patients. Mean length follow-up, 23 months. RESULTS: Neck stage predicted neck response to chemoradiotherapy; N3 necks showed more partial responses (P = 0.04), and N1 necks showed more complete responses (P = 0.12). Primary tumor site strongly predicted the pathologic response found on neck dissection in patients with a clinical partial response (cPR) following chemoradiotherapy. There was no difference in survival between patients with a clinical complete response (cCR) after chemoradiotherapy, and patients with a pathologic complete response (pCR) after neck dissection (P = 0.20); however, when grouped together, these patients survived longer than did patients with a pPR at neck dissection (P = 0.06). CONCLUSIONS: Clinical response to induction chemotherapy is a poor predictor of ultimate neck control. Induction chemotherapy followed by chemoradiotherapy, and planned neck dissection for patients with persistent cervical lymphadenopathy, provides good regional control.

Surgical morbidity of neck dissection after chemoradiotherapy in advanced head and neck cancer.

The use of chemotherapy and irradiation for organ preservation attempts to eliminate the need for extensive surgery in patients with advanced squamous cell carcinoma of the head and neck (SCCHN). We sought to characterize the morbidity of surgery in patients who needed surgery after treatment with induction chemotherapy followed by simultaneous chemotherapy and radiotherapy (chemoradiotherapy). The surgical morbidity within the first 30 postoperative days of 17 patients treated in an organ preservation approach between July 1991 and December 1994 was compared with a control group of patients undergoing similar surgical procedures during the same period. The organ preservation study patients underwent surgical procedures consisting of 18 neck dissections and 5 resections of the primary site. Six patients in the organ preservation study group experienced 8 surgical complications within the first 30 postoperative days, and most complications were minor. There was no significant difference in the duration of surgery or length of hospitalization between study patients and matched controls. Our surgical complication rate (35.3%) was higher but not statistically different from that of the control group, and compared favorably to reports of surgical morbidity (44% to 61%) in the literature on patients treated with chemoradiotherapy. The lower complication rate seen in this study may be a reflection of early surgical intervention as part of our organ preservation study scheme, the preponderance of neck dissections performed, and the limited number of pharyngeal procedures performed.

Participation in clinical trials: is it state-of-the-art treatment for African Americans and other people of color?

We have attempted to initiate a much needed constructive dialogue regarding the participation of African-American patients in clinical cancer research trials. It was our intent to provide a greater understanding of the historical context and evolving nature of clinical research trials pertaining to cancer. Some of the same challenges hold true for acquired immunodeficiency syndrome (AIDS)-related clinical research. Physicians interested in becoming a member of SOCRATES should contact Dr Roach at the University of California San Francisco.