Photodynamic therapy (PDT) and photodiagnosis (PD) using endogenous photosensitization induced by 5-aminolevulinic acid (ALA): current clinical and development status.

Exogenous provision of 5-aminolevulinic acid (ALA) to many tissues results in the accumulation of sufficient quantities of the endogenous photosensitizer protoporphyrin IX (PpIX) via the heme biosynthetic pathway, to produce a photodynamic effect when exposed to activating light. Therefore, ALA may be considered the only current photodynamic therapy (PDT) agent in clinical development that is a biochemical precursor of a photosensitizer. Topical ALA application, followed by exposure to activating light (ALA PDT), has been reported effective for the treatment of a variety of dermatologic diseases including cutaneous superficial and nodular basal cell carcinoma, Bowen's disease, actinic (solar) keratoses, and T cell lymphoma. Local internal application of ALA has also been used for selective endometrial ablation in animal model systems and, in human clinical studies, it has shown selective formation of PpIX within the endometrium. PpIX induced by ALA application has also been used as a fluorescence detection marker for photodiagnosis (PD) of cancer and dysplastic conditions of the urinary bladder and other organs. Systemic, oral administration of ALA has been used for ALA PDT of superficial head and neck cancer, various gastrointestinal cancers, and the condition known as Barrett's esophagus. This paper reviews the current clinical and development status of ALA PDT and PD.

Childhood brain tumors that occupy more than one compartment at presentation. Multiple compartment tumors.

Children whose brain tumor involves two or more compartments at presentation differ clinically and pathologically from children whose brain tumor is confined to one compartment. In this study of 3,291 children with a brain tumor, at least 10% had a tumor that occupied two or three compartments at first hospitalization. Infratentorial tumors occupying multiple compartments were 1.7 times more likely to involve the cervicomedullary junction than the mesodiencephalic junction. Younger children (1-3 years) were more likely to have had multiple compartment tumors than older children. Children whose tumor was limited to the infratentorial compartment had a longer survival than children whose tumor also occupied other compartments. Ependymoma, anaplastic ependymoma, and astrocytoma (nos) were over represented among infratentorial multiple compartment tumors. Pilocytic astrocytoma, primitive neuroectodermal tumor (medulloblastoma), and desmoplastic medulloblastoma were less likely to have occupied multiple compartments at the time of the first surgical exploration. The distributions of histologic features in tumors at the cervicomedullary junction differed from those in tumors limited to the posterior fossa or to the spinal canal. Seizures were more likely if the tumor was confined to the supratentorial compartment, whereas nausea or vomiting and headache were more likely if the tumor was confined to the infratentorial compartment. Children whose tumor was confined to the spinal canal were significantly more likely to have bladder symptoms and back and/or abdominal pain than those whose tumor also involved compartments above the foramen magnum. We conclude that brain tumors apparently confined to one compartment at presentation are biologically and structurally different from tumors evident in two or more compartments.

Fluorescein angiography complication survey.

This is a report on the results of a national survey designed to study the nature and frequency of moderate and severe complications of intravenous fluorescein angiography. In this survey, 2434 responding ophthalmologists reported on 221,781 fluorescein angiograms performed in the year 1984. Adverse reactions were classified as mild, moderate, severe, and death, depending on the duration of the effect, the necessity for medical intervention, the time required for its resolution, and the final outcome. The frequency rate for a moderate reaction was (1:63), for a severe reaction (1:1900), and for death (1:222,000). A review of previous studies on adverse reactions to the drug, a compilation of suggested methods for the amelioration and prevention of the complications, and a comparison of the responses of the general ophthalmic public to the members of The Macula Society are also reported.

Adaptation and cognition. II. Experimental study of the homospatial process in artistic creativity.

In a previously reported experimental study from an ongoing program of research on the creative process, the type of cognition designated as homospatial thinking was shown to function in the creation of literary metaphor. Homospatial thinking consists of actively conceiving two or more discrete entities occupying the same space, a conception leading to the articulation of new identities. Under experimental conditions involving facilitation of homospatial thinking through presentation of superimposed visual images, and control presentation of the same images separated and side by side, the superimposed presentation stimulated significantly more creative literary metaphors. In the currently reported experiment, the effect of such stimuli on creation in the visual arts was assessed. Forty-three artist subjects were randomly assigned either to a control group viewing three sets of slide photographs paired side by side on a projection screen or to an experimental group viewing the identical pairs of slide images superimposed on each other. Each subject created a pastel drawing stimulated by each of the three slide pairs. Resulting drawings were categorized according to the type of composition produced and quality of all drawings were independently rated by two internationally prominent artists. The primary results were that drawings produced in the superimposed slide condition which contained elements from both slides intermingled together were rated significantly more creative than a single element composition and also more creative than similar composition drawings stimulated by the separated slide condition (p less than .05). Production of a final drawing in which individual components are recognizable and intermingled together in response to the superimposed stimulus condition indicates the operation of homospatial thinking involving elements occupying the same space. Consequently, the results indicate a relationship between homospatial thinking and creative visual artistic effects.

Artistic creation as stimulated by superimposed versus separated visual images.

An experiment was performed to examine the role of homospatial thinking in visual art. Each of 43 university-level art students produced three drawing stimulated by pairs of slides. Subjects were randomly assigned to view the pairs either superimposed on one another or separated on the screen. Drawings were independently judged by two internationally noted artists. As predicted, drawings containing an element from each component image intermingled were higher in creative potential when stimulated by the superimposed presentation; however, when sketches from either condition did not clearly contain images from both slides, the separated image presentation yielded the more creative result. Although results favor the hypothesis in part, the overall ambiguity of the data illustrates some of the difficulties in studying creative thought processes under experimental conditions.