New experimental model of acute aqueductal blockage in cats: effects on cerebrospinal fluid pressure and the size of brain ventricles

It is generally assumed that cerebrospinal fluid (CSF) is secreted in the brain ventricles, and so after an acute blockage of the aqueduct of Sylvius an increase in the ventricular CSF pressure and dilation of isolated ventricles may be expected. We have tested this hypothesis in cats. After blocking the aqueduct, we measured the CSF pressure in both isolated ventricles and the cisterna magna, and performed radiographic monitoring of the cross-sectional area of the lateral ventricle. The complete aqueductal blockage was achieved by implanting a plastic cannula into the aqueduct of Sylvius through a small tunnel in the vermis of the cerebellum in the chloralose-anesthetized cats. After the reconstitution of the occipital bone, the CSF pressure was measured in the isolated ventricles via a plastic cannula implanted in the aqueduct of Sylvius and in the cisterna magna via a stainless steel cannula. During the following 2 h, the CSF pressures in the isolated ventricles and cisterna magna were identical to those in control conditions. We also monitored the ventricular cross-sectional area by means of radiography for 2 h after the aqueductal blockage and failed to observe any significant changes. When mock CSF was infused into isolated ventricles to imitate the CSF secretion, the gradient of pressure between the ventricle and cisterna magna developed, and disappeared as soon as the infusion was terminated. However, when mock CSF was infused into the cisterna magna at various rates, the resulting increased subarachnoid CSF pressure was accurately transmitted across the brain parenchyma into the CSF of isolated ventricles. The lack of the increase in the CSF pressure and ventricular dilation during 2 h of aqueductal blockage suggests that aqueductal obstruction by itself does not lead to development of hypertensive acute hydrocephalus in cats

Pollination ecology and breeding system of two Calceolaria species in Chile

Indexación: Web of Science; Scielo.Many angiosperms are exclusively dependent on pollinators for its reproduction (Matallana et al.2010; Arroyo et al. 2006). However, pollinators sometimes could be erratic and variable in relation to the ecological context (e.g., plant community composition), especially in alpine zones where it is known that pollinators decline in abundance with the increment in altitude (Arroyo and Squeo1990; Totland 1994). The latest could be critical in specialized pollination system and more over when specialized flowering plants inhabit in sympatry, potentially sharing the specialized floral visitors. In this context, it is expected that plant species develop reproductive strategies to ensure reproduction and/or exhibit some differences in their pollination ecology.http://ref.scielo.org/dv2yv

CISTERNAS.

A cisterna é uma boa reserva de água para usar na seca; O tamanho da cisterna e sua área de captação; Componentes básicos e cuidados essenciais com uma cisterna; Tratamento da água da cisterna.bitstream/item/133117/1/ID-31780.pdfElaboração: Everaldo Rocha Porto, CPATSA; Luiz Teixeira de Lima Brito, CPATSA; José Barbosa dos Anjos, CPATSA; Maria Sônia Lopes da Silva. CPATSA

Lymphangiography to treat postoperative lymphatic leakage: a technical review.

In addition to imaging the lymphatics and detecting various types of lymphatic leakage, lymphangiography is a therapeutic option for patients with chylothorax, chylous ascites, and lymphatic fistula. Percutaneous thoracic duct embolization, transabdominal catheterization of the cisterna chyli or thoracic duct, and subsequent embolization of the thoracic duct is an alternative to surgical ligation of the thoracic duct. In this pictorial review, we present the detailed technique, clinical applications, and complications of lymphangiography and thoracic duct embolization