Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

Ex Input:
Abstract: The posterior cell layer of the normal human cornea or "endothelium" was investigated by electron microscopy and immunocytochemistry. Ultrastructurally, the cells lacked the characteristic marker for endothelial cells (Weibel-Palade body). Immunoperoxidase studies demonstrated these cells to be negative for factor VIII antigen, but strongly positive for keratine, vimentin, S-100 protein, and neuron-specific enolase. The anterior epithelial cell layer showed identical immunoreactivity. These studies strongly suggest that the posterior cell layer of the cornea lacks ultrastructural and immunocytochemical markers of endothelial cells and both the anterior and posterior cell layers share similar cell markers. The authors propose that the posterior cell layer of the cornea should, therefore, not be misnamed as "endothelium."

Ex Output:
Cells

Ex Input:
Abstract: From December 1981 through August 1984, 24 patients with spinal cord compression syndrome due to epidural neoplasms were evaluated for radiotherapy with clinical examination, radiographs of the spine, and myelography. All plain films were reviewed, and mock radiotherapy fields designed using specific criteria for margins. The same patients were reviewed a second time considering the additional information provided by myelography. The initial treatment fields were found to be inadequate in 69% of the patients. Even in patients with discrete bony lesions, the results of myelography affected the treatment 45% of the time. A history of previous spinal irradiation significantly influenced port design in only 1 of the 7 patients who had received previous radiotherapy. Although invasive, myelography is essential in planning the treatment of spinal cord compression.

Ex Output:
Adult

Ex Input:
Abstract: Skilled forelimb use was studied in rats with unilateral lesions of the sensorimotor cortex, the caudate-putamen, or the dopaminergic nigrostriatal bundle, in a task involving reaching for food. Limb preference and efficiency were evaluated, as well as the relationship between limb use, spontaneous, and methamphetamine-induced rotation bias, both preoperatively and postoperatively. To induce use of the nonpreferred limb, a bracelet, which prevented reaching but not other movements, was attached to the forearm of the preferred forelimb. Whereas small cortical lesions of the forepaw area of the sensorimotor cortex mildly influenced limb preference and use, larger lesions changed preference. Furthermore, medium-sized sensorimotor cortex lesions impaired contralateral limb use, although surprising recovery occurred on the forced tests with the bracelet. Large cortical lesions abolished effective reaching even on the forced tests. Impairments similar to those following sensorimotor cortex lesions were also obtained following small and large caudate-putamen lesions. By contrast, unilateral dopamine depletions not only blocked use of the limb contralateral to the depletion but also impaired use of the ipsilateral limb. There was recovery in use of the ipsilateral forelimb but not the contralateral forelimb. Correlational analysis showed a weak relation between methamphetamine-induced rotation and limb preference preoperatively but no significant relation between these two variables postoperatively. The similarity in the deficits following sensorimotor cortex lesions and basal ganglia lesions suggests that skilled forelimb use depends upon a shared neural organization within the two systems.

Ex Output:
Animal