Evidence for abnormal cortical functional connectivity during working memory in schizophrenia.

OBJECTIVE: Disturbed neuronal interactions may be involved in schizophrenia because it is without clear regional pathology. Aberrant connectivity is further suggested by theoretical formulations and neurochemical and neuroanatomical data. The authors applied to schizophrenia a recently available functional neuroimaging analytic method that permits characterization of cooperative action on the systems level. METHOD: Thirteen medication-free patients and 13 matched healthy comparison subjects performed a working memory (n-back) task and sensorimotor baseline task during positron emission tomography. "Functional connectivity" patterns, reflecting distributed correlated activity that differed most between groups, were extracted by a canonical variates analysis. RESULTS: More than half the variance was explained by a single pattern showing inferotemporal, (para-)hippocampal, and cerebellar loadings for patients versus dorsolateral prefrontal and anterior cingulate activity for comparison subjects. Expression of this pattern perfectly separated all patient scans from comparison scans, thus showing promise as a trait marker. This result was validated prospectively by successfully classifying unrelated scans from the same patients and data from a new cohort. An additional 19% of variance corresponded to the pattern activated by the working memory task. Expression of this pattern was more variable in patients during working memory but not the control condition, suggesting inability to sustain a task-adequate neural network, consistent with the disconnection hypothesis. CONCLUSIONS: Pronounced disruptions of distributed cooperative activity in schizophrenia were found. A pattern showing disturbed frontotemporal interactions showed promise as a trait marker and may be useful for future investigations.

Developmental tasks: a key to reducing teenage pregnancy.

The developmental tasks of adolescence are discussed as a factor in some adolescents' risky sexual activity, which may lead to pregnancy. This theory is presented in the context of a case study. Nursing diagnoses, possible interventions, and nursing implications are examined in relation to assisting at-risk teens to meet their developmental needs. It is hoped that this article will stimulate further dialogue in the literature of developmental causes of teenage pregnancy, identification of those at risk, and appropriate nursing responses.

System for control, monitoring ensures efficient linen use.

By implementing recommendations from a short-term consulting program, a hospital regained control over the use, costs, and quality of its linen service. Long-term measures, such as use of rescheduled distribution, appropriate quotas, consistent policies, a hospital linen manager, and reports for measuring performance, have cut the costs and improved the service of the linen department.