[Clinical diagnostic of brain death and transcranial Doppler, looking for middle cerebral arteries and intracranial vertebral arteries. Agreement with scintigraphic techniques]. / Diagnóstico clínico de muerte encefálica y empleo del Doppler transcraneal, con ecografía de las arterias cerebrales medias y el segmento intracraneal de las arterias vertebrales. Concordancia con los hallazgos de la gammagrafía cerebral.

INTRODUCTION: The Real Ordinance 2070/1999 meant an important modification in the legislation, when including transcranial Doppler (TCD) in explorations to confirm the clinical diagnosis of brain death (BD). Habitually for their employment in the diagnosis of BD, we look for blood flow signal from the middle cerebral arteries (MCA) and the basilar artery (BA). OBJECTIVES: To check the effectiveness of the TCD like test of BD, looking for both middle cerebral arteries (MCA) and both intracranial vertebral arteries (VA), instead of the BA, and taking as Gold Standard cerebral scintigraphic techniques. PATIENTS AND METHODS: . We present 25 patients diagnosed clinically with BD; on these TCD was carried out to confirm BD. Later on we proceeded to carry out cerebral scintigraphic techniques in all these cases. As statistical tool the test of c2 is used with confidence interval of 95%. RESULTS: In 24 of the 25 cases, the TCD was effective in confirming the diagnosis of BD. In the remaining patient, a false positive result was obtained, since the TCD didn't reveal flow in the infratentorial compartment, as contrary to the cerebral scintigraphic techniques which showed the presence of residual flow at this level; this residual flow disappeared in 36 hours. This patient was hemodynamically unstable during TCD exploration. CONCLUSIONS: In our results the TCD obtains a reliability of 100% when confirming the absence of blood flow in the supratentorial compartment; nevertheless the false positive result obtained at the infratentorial level, warns us to be cautious in accepting the flow from the VA as a test of absence of flow at the infratentorial compartment, especially in those patients with hemodynamic instability.

Antiproliferative effect of retinoic acid in intravitreous silicone oil in an animal model of proliferative vitreoretinopathy.

PURPOSE: To evaluate, in vitro, the solubility and stability of all-trans RA in silicone oil (SiO) and, in vivo, the stability and the antiproliferative effect of all-trans RA in SiO on an experimental model of PVR. METHODS: The solubility and stability of RA in SiO, in vitro and in vivo, were evaluated by HPLC. Rabbits underwent unilateral gas-compression vitrectomy and gas-SiO exchange. Rabbits received 10 micrograms (n = 17), 5 micrograms (n = 11), and 2 micrograms (n = 9) of all-trans RA in SiO, and SiO only (n = 12). All rabbits received an intravitreous injection of 150,000 fibroblasts. RESULTS: RA is stable in SiO in vitro, but some isomerization from all-trans to 13-cis was observed under light exposure. In vivo, after 1 week, trace amounts of RA in SiO were observed in the controls and in the experimental animals, suggesting a steady state between the release of RA from the SiO and from the retina to the SiO. The rate of fractional retinal detachment was significantly lower in the animals that received 10 and 5 micrograms of RA than in the controls (P < 0.05). No statistical differences were found between the eyes treated with 10 and 5 micrograms of RA. Eyes that received 2 micrograms of RA showed no difference from the control group. CONCLUSIONS: The in vivo data suggest that retinoic acid might be useful as an antiproliferative agent in human eyes.

Silicone oil as a delivery vehicle for BCNU in rabbit proliferative vitreoretinopathy.

The antiproliferative properties of a single intravitreous injection of BCNU [carmustine; 1,3-bis(2 chloroethyl)-1-nitrosourea] dissolved in 1 ml of medical grade, 1,000-centistoke silicone oil were evaluated in a rabbit model of proliferative vitreoretinopathy (PVR). 10 micrograms and 15 micrograms of BCNU in 1 ml silicone oil resulted in a 46% and 27% reduction in the incidence of retinal detachments, respectively. Chi-square tests showed a significant statistical difference (P < 0.05) between the control and treated groups. However, histopathologic examination of the eyes injected with BCNU and silicone oil indicated some retinal disorganization even at the lower therapeutic levels. With a therapeutic index of < 1.0, BCNU in silicone oil has a low margin of safety for treatment of PVR. Nevertheless, this study demonstrates that silicone oil when used for retinal tamponade in PVR may be the vehicle for delivery of a lipophilic antiproliferative agent.

[Contribution of iatrogenic pathology to all pleural diseases]. / Contribution de la pathologie iatrogène à l'ensemble des maladies de la plèvre.

The contribution of iatrogenic pathology to all pleural diseases was evaluated in a series of 562 cases by studying pleural effusions or pneumothoraxes induced by medical interventions. Iatrogenic pathology accounted for 5.5% of all pleural diseases (effusion 2.5%, pneumothorax 3%). The medical interventions most frequently responsible for pleural effusion were surgical operations performed in the thorax, but also on abdominal organs located close to the diaphragm. Pneumothorax was almost always induced by diagnostic manoeuvres: essentially needle biopsy and, less frequently, transbronchial lung biopsy under fibroscopy. It must be pointed out that iatrogenic pleural lesions are small and usually asymptomatic.