The effects of wulst ablations on color, brightness and pattern discrimination in pigeons (Columba livia).
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Biomedical subjects
Publications and source records attributed to M B Pritz.
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Nucleus rotundus is a prominent nucleus in the dorsal thalamus of nonmammalian amniotes. In one group of reptiles, Caiman crocodilus, previous studies have identified three parts of this neuronal aggregate. The central portion, the rotundal core, which receives visual input from the midbrain and projects to a restricted portion of the telencephalon, contains relay cells only. Previous examinations using Nissl morphology indicated that neurons of the rotundal core were not a homogeneous population of cells. The present investigation utilized another methodology to examine cell populations within the rotundal core, immunoreactivity to the calcium binding proteins, calbindin/calretinin and parvalbumin. Light microscopic observations revealed the following features. First, calbindin/calretinin immunoreactive neurons and parvalbumin immunoreactive neurons were present in the rotundal core. Of these two antibodies, immunoreactivity to calbindin/calretinin was much more robust and calbindin/calretinin immunoreactive neurons were more numerous than parvalbumin cells. Second, neurons immunoreactive to either calbindin/calretinin or parvalbumin were not homogeneous but comprised several populations based on perikaryal shape and size and neuronal process morphology. These results are compared with similar data in other amniotes.
A closed external ventricular drainage system that incorporates a Broviac catheter, with its dacron cuff, is described and its use is detailed. This device has been placed in 17 patients who have undergone 19 procedures. Indications for prolonged cerebrospinal fluid (CSF) drainage were: CSF leak (1 child) and shunt infection (16 children). Drainage was maintained for an average of 19 days, with a range of 6-47 days. The child with the CSF leak had resolution of this problem after 15 days, whereupon the system was removed. Thirteen of the 16 patients with shunt infections eventually underwent shunt placement. Two of the children in this group developed a shunt infection unrelated to their original septic episode that required placement of a second Broviac ventriculostomy. Two of the 3 children who did not undergo permanent shunt placement expired from other causes. Both of these children had clinically functioning Broviac ventriculostomies and culture-proven sterile CSF at the time of death. The remaining child with an infected shunt died of overwhelming sepsis. Complications included: ventricular catheter revision (4 cases), irrigation of the system (4 cases), and secondary CSF infection (1 case). The infection attack rate was 1 in 361 patient-catheter days, or 2.77/1,000 patient-catheter days. The advantages of the Broviac ventriculostomy are two. First, this system is highly resistant to infection. Second, the device is difficult to dislodge.
Four patients, including one preoperative patient, developed neurological deficits associated with angiographically proven cerebral vasospasm and were treated with intravascular volume expansion. Indicator dilution techniques were employed to monitor intravascular volume and cardiac functions during treatment. All four patients improved promptly. None of the patients developed cardiac or pulmonary dysfunction despite marked increase in intravascular volume and despite several risk factors such as cardiac symptoms, electrocardiographic abnormalities, and advanced age. The techniques of monitoring and controlling intravascular volume are described. We believe that this is an important therapeutic adjunct for certain aneurysm patients.