A cross-cultural investigation of suicidal behavior and attitudes in Austrian and Turkish medical students

Purpose  

This cross-cultural study investigated the prevalence of suicidal behavior and attitudes towards suicide and reactions to suicidal individuals in 320 Austrian and 326 Turkish medical students.     

Tardive parkinsonism in a bipolar patient: Post-mortem examination supports a physiological rather than pathological dysfunction

We describe a case of tardive parkinsonism in the setting of bipolar syndrome, and we offer pathological confirmation that idiopathic Parkinson disease was not the underlying etiology. A 74-year-old Hispanic woman with a history of bipolar disease was noted to have oro-buccal-lingual chorea and parkinsonian symptoms such as resting tremor, rigidity, bradykinesia, and gait disorder persisting several months after neuroleptic discontinuation. She had minor improvement in ambulation with levodopa treatment, and she significantly improved in ambulation only during her manic states. Examination of the subject's post-mortem brain revealed no explicit evidence of degeneration in substantia nigra or other brainstem centers, and no nigral or cortical Lewy bodies were present. Glial cytoplasmic inclusions (characteristic of multiple systems atrophy) and globose neurofibrillary tangles (seen in progressive supranuclear palsy) were not seen either. This patient's presentation was most consistent with neuroleptic-induced parkinsonism and tardive dyskinesia; the etiology was likely related to previous neuroleptic exposure.     

"Good enough solutions" and the genetics of complex diseases

In this Emerging Science Review, we discuss a systems genetics strategy, which we call gene module association study (GMAS), as a novel approach complementing genome-wide association studies (GWAS), to understand complex diseases by focusing on how genes work together in groups rather than singly. The first step is to characterize phenotypic differences among a genetically diverse population. The second step is to use gene expression microarray (or other high-throughput) data from the population to construct gene coexpression networks. Coexpression analysis typically groups 20 000 genes into 20 to 30 modules containing tens to hundreds of genes, whose aggregate behavior can be represented by the module's "eigengene." The third step is to correlate expression patterns with phenotype, as in GWAS, only applied to eigengenes instead of single nucleotide polymorphisms. The goal of the GMAS approach is to identify groups of coregulated genes that explain complex traits from a systems perspective. From an evolutionary standpoint, we hypothesize that variability in eigengene patterns reflects the "good enough solution" concept, that biological systems are sufficiently complex so that many possible combinations of the same elements (in this case eigengenes) can produce an equivalent output, that is, a "good enough solution" to accomplish normal biological functions. However, when faced with environmental stresses, some "good enough solutions" adapt better than others, explaining individual variability to disease and drug susceptibility. If validated, GMAS may imply that common polygenic diseases are related as much to group interactions between normal genes, as to multiple gene mutations.