15 research outputs found
Intraoperative Doppler color flow imaging combined with regulation of arterial inflow during surgery for intrahepatic arterioportal fistula
Large fistulas associated with impaired liver function should be treated by direct obliteration or removal of the shunt orifice. In a large shunt with the portal branch lying on the arterial branch, identification of the exact site of the fistula can be a challenge. We report a case of impaired liver function due to a large intrahepatic arterioportal fistula. The site of the shunt orifice could not be located accurately by preoperative imaging. However, intraoperative color Doppler ultrasonography and the simple regulation of arterial inflow clearly demonstrated the shunt orifice. This original technique has allowed the precise definition of the problem and has optimized the surgical treatment for this critical condition. Consequently, it should be considered a new option for the definition and management of large intrahepatic arterioportal fistulas
Intracranial cerebrospinal fluid measurement studies in suspected idiopathic normal pressure hydrocephalus, secondary normal pressure hydrocephalus, and brain atrophy
Objective: To investigate intracranial cerebrospinal fluid (CSF) distribution in patients with a clinical diagnosis of idiopathic normal pressure hydrocephalus (INPH). Methods: 24 patients with a clinical diagnosis of INPH were studied. Control groups comprised 17 patients with secondary normal pressure hydrocephalus (SNPH), 21 patients with brain atrophy, and 18 healthy volunteers. Ventricular volume (VV) and intracranial CSF volume (ICV) were measured using a magnetic resonance based method and the VV/ICV ratio was calculated. Results: The SNPH group showed a marked increase in the VV/ICV ratio compared with the healthy volunteers (37.8% v 15.6%, p < 0.0001). The brain atrophy group showed a significant increase in ICV compared with the healthy volunteers (284.4 ml v 194.7 ml, p =0.0002). The INPH group showed an increase in ICV (281.2 ml, p = 0.0002) and an increase in the VV/ICV ratio (38.0%, p < 0.0001). Fifteen of 24 INPH patients underwent shunting; 11 improved and four did not. Conclusions: The results suggest that INPH patients have brain atrophy in addition to hydrocephalic features. This may help to explain the difficulties encountered in the diagnosis and the unpredictable response rate to shunt surgery in INPH patients
The colouration toolkit of the pipevine swallowtail butterfly, Battus philenor: Thin films, papiliochromes, and melanin
The ventral hindwings of Pipevine Swallowtail butterflies, Battus philenor, display a colourful pattern, created by variously coloured wing scales. Reflectance and transmittance measurements of single scales indicate that the cream and orange scales contain papiliochrome pigments, while brown, black and blue scales contain melanin. Microspectrophotometry and scatterometry of both sides of the wing scales show that the lower lamina acts as a thin film, with reflection properties dependent on the scale's pigmentation. Notably in the orange scales, the reflectance spectrum of the lower lamina is tuned to the pigment's absorbance spectrum. The dorsal hindwings of the male (but not the female) B. philenor are blue-green iridescent. At oblique illumination, the light reflected by the male's dorsal hindwings can be highly polarised, which may have a function in intersexual signalling