Retro-esophageal subclavian artery: a case report.

This case report presents the finding of an aberrant right subclavian artery during the routine dissection of 230 human adults specimens. The case which we describe appeared in an 82-year-old male donor, in whom the right retro-esophageal subclavian artery was observed as the last branch of the aortic arch. The rate of occurrence of this variation is stated to be less than 1%. This variation is described in detail; embryology and anatomy are reviewed and we discuss it in relation to other cases. The aortic arch was dissected, and its branches were described as regards their relations, length and diameter.

Stimulus frequency affects c-fos expression in the rat visual system.

We have characterised the c-fos expression patterns in various centers of the visual pathway of adult rats monocularly stimulated either by continuous or flickering light at different frequencies. Results show different immunocytochemical patterns in all centers studied, the geniculate lateral complex (LGC), superior colliculus (SC) and primary visual cortex (Oc1), depending on the physical characteristics of the stimulus (blinking frequency and light wavelength). After stimulation of the left eye, the ipsilateral pathway presents a substantial density of immunoresponsive cells, which is greater than expected with respect to the number of fibers that project ipsilaterally from the retina to the LGC and the superficial layers of the SC. A surprisingly high positive immunoresponsiveness is obtained in all cases with coherent light stimulation in the red spectrum (634 nm).

[Spontaneous spinal extradural hematomas: report of two cases]. / Hematomas extradurales espinales espontáneos: presentación de dos casos.

INTRODUCTION AND CLINICAL CASES: We present two cases of spontaneous spinal extradural hematoma, which occurred in 1996 and were admitted to and operated on by our Department. Both patients were women. No cause for the bleeding was found in either case. Both presented with the site of the lesion in the thoracic spine, although at different levels. There was acute onset of the clinical condition. The best diagnostic procedure was MR. The treatment of choice was surgical and the results related to the rate of onset of the clinical picture and the time elapsed before operation. CONCLUSION: The form of presentation is discussed, together with the importance of early diagnosis and the relation to emergency surgical treatment.

One further case of unusual origin of three hepatic arteries.

This article describes a triple vascularization of the liver which is not a common vascular anomaly. Dealing with this particular kind of vascularization, we note the following: a main hepatic a. which enters in the right lobe of the liver and two accessory arteries, the right hepatic a. (a branch of the superior mesenteric a.) and left hepatic a. (from the left gastric a.). In the same way, the cystic a. has an unusual origin: the right accessory hepatic artery. The whole hepatic pedicle was dissected, and its branches were described, indicating their relations, length and diameter.