Foraging activity of the snail kite, Rostrhamus sociabilis (Aves: Accipitridae) in wetlands of southern Brazil.

The snail kite (Rostrhamus sociabilis) is widely distributed in the American continent. Its specialised diet consists mostly of the gastropod mollusk Pomacea sp and its foraging strategy probably varies depending on the season, prey availability, and climate factors, which can be reflected in its semi-nomad behaviour. This study was aimed at examining the hunting strategy of the snail kite, and its association with climate factors and habitat heterogeneity. Direct observations of birds between January 2010 and March 2011 in southernmost Brazil revealed that hunting was still the predominant foraging strategy (79% of records) to capture mollusks. Despite morphological specialisations to extract mollusks from the shells, the handling time (average = 92.4 s) was twice as much the time between prey search and capture (average = 55 s). The increase in the number of mollusks ingested apparently occurs when the resting time on perches or any other substrates near the hunting sites decreases between successive unsuccessful attempts. The correlation between the number of consumed preys and the climatic variables examined was low. Regarding habitat heterogeneity, our findings suggest that birds forage preferentially in marshes with low vegetation, which may increase the access to mollusks. The hunting efficiency of the snail kite was high (76 % successful attempts) compared to those of other birds of prey.

Foraging activity of the snail kite, Rostrhamus sociabilis (Aves: Accipitridae) in wetlands of southern Brazil / Atividade de forrageio de gavião-caramujeiro, Rostrhamus sociabilis (Aves: Accipitridae) em áreas úmidas do sul do Brasil

The snail kite (Rostrhamus sociabilis) is widely distributed in the American continent. Its specialised diet consists mostly of the gastropod mollusk Pomacea sp and its foraging strategy probably varies depending on the season, prey availability, and climate factors, which can be reflected in its semi-nomad behaviour. This study was aimed at examining the hunting strategy of the snail kite, and its association with climate factors and habitat heterogeneity. Direct observations of birds between January 2010 and March 2011 in southernmost Brazil revealed that hunting was still the predominant foraging strategy (79% of records) to capture mollusks. Despite morphological specialisations to extract mollusks from the shells, the handling time (average = 92.4 s) was twice as much the time between prey search and capture (average = 55 s). The increase in the number of mollusks ingested apparently occurs when the resting time on perches or any other substrates near the hunting sites decreases between successive unsuccessful attempts. The correlation between the number of consumed preys and the climatic variables examined was low. Regarding habitat heterogeneity, our findings suggest that birds forage preferentially in marshes with low vegetation, which may increase the access to mollusks. The hunting efficiency of the snail kite was high (76 % successful attempts) compared to those of other birds of prey.(AU)

O gavião-caramujeiro (Rostrhamus sociabilis) possui ampla distribuição no continente americano e apresenta dieta especializada no molusco gastrópode Pomacea sp. Possivelmente, a estratégia de forrageio da espécie responde às variações sazonais na disponibilidade de presas, bem como aos fatores climáticos, o que pode refletir em seu comportamento seminômade. O objetivo desse estudo foi avaliar a estratégia de caça do gavião-caramujeiro, buscando suas associações quanto aos aspectos climáticos e à heterogeneidade do habitat. Observações diretas das aves, feitas entre janeiro de 2010 e março de 2011 no extremo sul brasileiro, revelaram que, para a captura dos moluscos, as aves usaram predominantemente a estratégia de caça do tipo still hunting (79% dos registros). Apesar de apresentar especializações morfológicas para a extração dos moluscos da concha, a avaliação do tempo empregado na manipulação (média = 92,4 s) foi quase o dobro do desprendido entre a procura e a captura (média = 55 s) das presas. Aparentemente, o aumento no número de moluscos ingeridos ocorre por meio de redução no tempo de repouso entre sucessivas investidas de captura mal sucedidas, tal como pelo uso de poleiros ou quaisquer outros substratos próximos aos locais de captura. O número de presas consumidas apresenta baixa relação com as variáveis climáticas testadas. Quanto à heterogeneidade do habitat, os dados sugerem que as aves forrageiam preferencialmente em banhados com cobertura vegetal rasteira, o que poderia aumentar a acessibilidade aos moluscos. O gavião-caramujeiro apresentou alta taxa de eficiência de caça (76% das investidas tiveram êxito), revelando a eficiência da estratégia de caça desta ave quando comparada a outras aves de rapina.(AU)

La Medicina Nuclear más allá de la imágenes / The Nuclear Medicine beyond the images

La Medicina Nuclear clínica se apoya tradicionalmente en tres grandes pilares básicos, estos son las imágenes, la terapia con radionucleidos y las técnicas "in vitro". En los últimos años, tanto con el desarrollo de las imágenes moleculares como con el surgimiento de nuevas aplicaciones terapéuticas con radionucleidos, se nos abren insospechadas oportunidades para que nuestra especialidad ocupe un valioso sitial en las nuevas aplicaciones oncológicas. En este artículo se revisa nuestra experiencia en dos novedosas áreas en las cuales hemos tenido la oportunidad de desarrollarlas en nuestro centro. Estas son la terapia con 90Y-DOTATOC en tumores con sobre-expresión de receptores de somatostatina[1] (carcinoides, neuroendocrinos y otros) y el uso de 90Y-Ibritumomab-Tiuxetan en Linfomas No Hodgkin de células B con presencia de antígeno CD20+[2].

Cold-hot mismatch between Tc-99m HMPAO-labeled leukocytes and Tc-99m ciprofloxacin in axial skeleton infections: a report of three cases.

Radiolabeled leukocyte scintigraphy is a well-established technique for the diagnosis of inflammation and infection with a typical presentation of a hot spot within the abnormal areas. However, in some cases of osteomyelitis of the axial skeleton, a cold defect pattern has been described. Tc-99m ciprofloxacin is a new agent claimed to be specific for imaging sites containing viable bacteria. In this report, we present three cases of proved bacterial infection of the axial skeleton with a mismatch pattern between Tc-99m ciprofloxin and tagged leukocytes. Although Tc-99m-labeled leukocyte scanning showed a cold defect, probably caused by bone marrow replacement, the Tc-99m ciprofloxacin consecutively revealed a hot spot at the site of infection. These data suggest that Tc-99m ciprofloxacin should be a better agent than radiolabeled leukocytes for detecting osteomyelitis of the axial skeleton.

[Parathyroid scintigraphy with Tc99m Sestamibi]. / Cintigrafía de paratiroides con Tc99m Sestamibi.

BACKGROUND: Parathyroid scintigraphy with Tc99m Sestamibi, a tracer that is taken up by hyperfunctioning parathyroid tissue, has a high yield in the diagnosis of abnormal parathyroid growths. AIM: To assess the usefulness of parathyroid scintigraphy with Tc99m Sestamibi in patients with suspected hyperparathyroidism. PATIENTS AND METHODS: We analyzed retrospectively 29 patients with suspected hyperparathyroidism, in whom a scintigraphy with Tc99m Sestamibi was performed. RESULTS: Twenty four of 25 patients in whom hyperfunctioning parathyroid tissue was evidenced with scintigraphy, were operated. Histological diagnosis of the excised parathyroid gland, showed 23 adenomas and 1 hyperplasia. Anatomical location disclosed by scintigraphy was concordant with surgical findings in all cases, including a mediastinic adenoma. Of the four patients with negative scintigraphic findings, two had transitory PTH elevations and in two the presence of adenoma or hyperplasia could not be demonstrated with other diagnostic procedures. CONCLUSIONS: Parathyroid scintigraphy with Tc99m Sestamibi had an 86% sensitivity for the detection of hyperfunctioning parathyroid tissue in patients with elevated PTH.

[Renal artery thrombosis in newborn infants undergoing umbilical artery catheterization]. / Trombosis de arteria renal en recién nacidos sometidos a cateterización de la arteria umbilical.

A prospective study to detect renal artery thrombosis by radionuclide renal scintigraphy in newborn infants who underwent umbilical arterial catheterization over a one year period was done: 62 babies were catheterized, 92% were preterm and 85% had severe respiratory distress syndrome that required mechanical ventilation, 25/62 (40.3%) survived and in all of them Tc-99m DMSA scans were taken at a median of 5 days after withdrawal of the umbilical artery catheters (range 9 h to 29 days). A baby with renovascular hypertension had a DMSA scan which showed segmental vascular defect in one kidney. Another patient had left iliac artery thrombosis and two others showed evidence of transient vasospasm. Death occurred in 37/62 (59.7%), 92% of whom underwent autopsy studies which showed aortoiliac thrombosis in 8.8%, all of them without clinical symptoms. Other 12 newborn infants who died without previous umbilical artery catheterization had no evidence of thrombosis at autopsy.

[Computerized tomography of the skull in the diagnosis of meningiomas. Report of 16 cases]. / Tomografia computadorizada do crânio no diagnóstico dos meningiomas.

The authors report the usefulness of the skull's computerized tomography for the exact diagnosis of the meningiomas. The 16 cases reported were comproved surgical and histologically. The average was 52.1 years. They dealt out 10 females and 6 males. According to their localization, there are 5 on the orbital cavity and/or sphenoid ridge (31.2%), 3 of the falx (18.7%), 3 parasagitals (18.7%), 2 suprasellars (12.5%), 2 of the convexity (12.5%) and 1 of the tentorium (6.2%). The authors concluded that the computerized tomography of the skull is of high positiveness (95-98%), without damages for the patient, and nowadays it allows precocity in diagnosis, and, consequently, with better therapeutic results.