RESUMO
This study increases the known biodiversity of cnidarian parasites in neotropical bryconid fishes. Two novel Myxobolus species are described based on morphology, ultrastructure and small subunit ribosomal DNA (ssrDNA) sequencing: Myxobolus vetuschicanus n. sp. infecting fins of Salminus franciscanus and Myxobolus mineirus n. sp. infecting the mesentery of Brycon orthotaenia from the São Francisco River basin, Minas Gerais State, Brazil. Ultrastructural analysis of the two species revealed an asynchronous sporogenesis process, with germinative cells and young developmental stages of myxospores in the periphery of the plasmodia. In M. vetuschicanus n. sp., the plasmodia were surrounded by a layer of fibroblasts and in M. mineirus n. sp., the plasmodial membrane had direct contact with the host tissue. The phylogenetic analysis based on the ssrDNA of Henneguya/Myxobolus species showed that the two novel Myxobolus species grouped in subclades together with other parasite species of bryconid fishes.
Assuntos
Biodiversidade , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Myxobolus/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Nadadeiras de Animais/parasitologia , Animais , Brasil , DNA Ribossômico , Brânquias/parasitologia , Myxobolus/classificação , Filogenia , Subunidades Ribossômicas Menores de Eucariotos , Rios/parasitologiaRESUMO
Metastatic breast cancer (MBC) entails an overall 5-year survival of approximately 25%. The choice of therapy is influenced by expression of the HER2 gene and hormone receptors, by a disease-free interval, and by age. The use of paclitaxel combined with gemcitabine (doublet protocol) has shown efficacy as first-line treatment for MBC in either initial or maintenance therapy when compared to monotherapy with paclitaxel. There is evidence showing that the doublet protocol is a good alternative to maintenance therapy in women under 50 years old. Nevertheless, there is a lack of information concerning individuals above that age. We report the case of an 81-year-old patient presenting with recurrence of MBC, with lung and skin metastases both positive for hormone receptor and negative for HER2. We implemented a therapy based on the combination of gemcitabine and paclitaxel for 12 cycles, when complete response was achieved. Currently, 16 months after this achievement, the patient is receiving maintenance treatment under the doublet protocol, presenting acceptable parameters of toxicity since the beginning of treatment, which shows satisfactory tolerability and management of chemotherapy in an elderly patient. We suggest that the maintenance treatment protocol with a doublet might be an alternative with a satisfactory response in patients with MBC.
RESUMO
A new species of myxosporea (Henneguya rotunda n. sp.) was found in the membrane of the gill arch and the fins of Salminus brasiliensis in the Mogi Guaçu River, municipality of Pirassununga, São Paulo state, Brazil. Morphological and morphometric analyses using light microscopy revealed parasites with similar characteristics at both infection sites. The mature spores found infecting the fins had oval spore body with 7.1 ± 0.2 µm in length, 5.6 ± 0.2 µm in width, 3.7 ± 0.1 µm in thickness, 16.4 ± 1.2 µm in length of the caudal process, and 23.6 ± 1.1 µm in total length of the spore. In a frontal view, the polar capsule was observed to be symmetrical with 3.4 ± 0.2 µm in length and 1.8 ± 0.1 µm in width. Mature spores contain six to seven turns of the polar filaments. The morphometric data concerning the spores obtained from plasmodia from the membrane of the gill arch were similar to those from the fins. Ultrastructure analysis revealed that the plasmodial wall was formed by a single membrane and had numerous pinocytotic canals connecting the outside of the plasmodia to the ectoplasm zone. Beyond that, various electron-translucent vesicles also were observed at the periphery of the plasmodium. The molecular analyses of the 18S rDNA gene from the spores obtained from the gill arch membrane and fin membrane showed that these sequences shared 100% similarity. Phylogenetic studies using maximum parsimony and maximum likelihood methods demonstrated the polyphyletic clustering of the myxosporean parasites of characiform fishes. H. rotunda n. sp. clustered as a sister species of Myxobolus pantanalis, also a parasite of S. brasiliensis.
Assuntos
Nadadeiras de Animais/parasitologia , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Myxozoa/classificação , Myxozoa/ultraestrutura , Animais , Brasil , Myxozoa/citologia , Filogenia , RNA Ribossômico 18S/genética , RiosRESUMO
During a survey of myxozoan parasites of freshwater fish from the Mogi Guaçu River in São Paulo State, Brazil, plasmodia of Henneguya visibilis n. sp. were found on the fins of Leporinus obtusidens (Characiformes: Anostomidae). The plasmodia, which were observed on five out of eight (62.5%) L. obtusidens examined, were 400-1,000 µm long. Mature spores were elongated with a spore body 10.8 ± 0.6 µm long and 3.9 ± 0.2 µm wide, a caudal process 18 ± 1.2 µm long, and a total spore length of 26.8 ± 1.1 µm. Polar capsules were elongated 4.9 ± 0.3 µm long and 1.4 ± 0.1 µm wide. Histological examination indicated that the plasmodia developed in the connective tissue, and no inflammatory infiltrate was observed at the infection site. Ultrastructural analysis showed a plasmodium wall with a single membrane and several pinocytotic canals. Sporogenesis occurred from the periphery to the center of the plasmodia. Phylogenetic analysis of the 18S rDNA sequence using maximum likelihood and maximum parsimony methods showed H. visibilis n. sp. positioned in a sub-clade composed of Henneguya/Myxobolus parasites of several freshwater fish families.