Benign giant cell tumour with metastases to bone and lung. One case studied over 20 years

We report a case of benign giant cell tumour which over a 20-year period has given rise to pulmonary and bony metastases. The indolent nature of these metastases is remarkable, with considerable implications for the long-term management of such cases.     

Chorioretinal neovascular membranes complicating contusional eye injuries with indirect choroidal ruptures.

Chorioretinal neovascular membranes are a recognised but rare cause of late visual loss in eyes suffering contusional injuries. A series of eight cases is presented all with indirect choroidal ruptures involving the perifoveal region. Two main patterns of 'at risk' rupture were noted: a temporally situated rupture passing almost directly through the fovea, and a rupture which curves inferior or superior to the optic disc stopping just short of the fovea. In six of eight cases there was only a partial thickness rupture of the choroid. These neovascular membranes may present at any time after the original injury, either early (within six months of the injury), which could be related to persistence of the normal reparative neovascular response, or late (at least one year after the injury), which are more likely to have resulted from a secondary breakdown of the outer blood-retina barrier.     

Electrophoretic isolation of extrachromosomal DNA from tumor cells

Gene amplification allows transformed cells to overexpress specific genes and gain a survival advantage. For this reason, cloning and characterization of amplified genes can improve our understanding of the biology of transformed cells. The techniques of in-gel renaturation and chromosome microdissection can enrich for amplified DNA sequences, but both are labor intensive and have other drawbacks. We have developed an alternative strategy of enriching for amplified DNA sequences that involves two-directional agarose gel electrophoresis of extrachromosomal circular DNA. Extrachromosomal circles can be detected with repetitive DNA probes and can be used to produce DNA probes suitable for fluorescence in situ hybridization for location of genomic origin. The ability to enrich for amplified DNA without specialized equipment or transformed cell metaphases should prove useful in the search for new genes which are important in tumor cell progression.     

Subcortical white matter lesions in osmotic demyelination syndrome.

We describe a case of histologically proved osmotic demyelination syndrome. In addition to abnormal T2 signal within the pons and thalami, MR showed linear enhancing lesions at the cortical medullary junction.     

The effects of normal aging on humor appreciation.

The importance of humor in healthy aging is being recognized. We compared elderly and young participants on their comprehension and appreciation of, and reaction to, verbal and nonverbal humor tests. Cognitive processes-working memory, cognitive flexibility, verbal abstraction, and visual scanning-were studied in relation to humor. Results indicated a relative deficit in the elderly in the cognitive comprehension of humor-selecting punch lines to jokes and in a cartoon array test. Measures of cognitive function correlated with humor comprehension. In contrast to this deficit in comprehension, the elderly showed intact affective appreciation and emotional reactiveness. Because of the hypothesis of frontal lobe degeneration as a basis for changes with aging, we compared the elderly to patients with focal frontal lesions. In this comparison, the elderly were significantly better than the patients in their comprehension of humor. They also displayed intact appreciation of humor compared to patients with frontal lesions. This preliminary study suggests that preserved affective responsiveness may underlie the success in using humor as a coping mechanism in the elderly.     

Complex Genetic Disease: Can Genetic Strategies in Alzheimer's Disease and New Genetic Mechanisms Be Applied to Epilepsy?

Summary: Strategies used in molecular genetics have changed modern neurology. The gene or genes responsible for several major neurologic diseases have now been identified using "reverse" or positional genetics. Unexpected new genetic mechanisms have been discovered in human neurologic diseases, including (a) identical mutations of the prion protein gene in Creutzfeldt-Jakob disease and fatal familial insomnia with the phenotypic expression directed by an accompanying polymorphism; (b) stable duplications of chromosome 17 in Charcot-Marie-Tooth disease (type 1 A) that involve many genes, only one of which appears to cause neuropathy; and (c) highly variable, dynamic mutations in myotonic dystrophy, fragile X syndrome, and Kennedy's syndrome that modulate variable expressivity in multiple tissues. There is growing recognition that neurologic diseases are often complex genetic diseases with multifactorial rather than simple modes of inheritance. For example, genetic association/linkage strategies have interacted with biochemistry and immunopathology studies to produce new insights into the disease mechanism of late-onset Alzheimer's disease. The role of apolipoprotein E in late-onset Alzheimer's disease is an example of how new analytical techniques of genetic disease can be applied to dissect multiple genes. Similar research strategies are suggested for the study of epilepsy as a complex disease.