Relationship between apathy and cognitive dysfunctions in de novo untreated Parkinson's disease: a prospective longitudinal study.

BACKGROUND AND PURPOSE: Apathy may be either a symptom of major depression or a behavioral disturbance occurring in concomitance with depression or alone in Parkinson's disease (PD). The aim of the present study was to determine the progression of cognitive impairment in drug-naïve untreated PD patients with or without clinically significant apathy. METHODS: Sixty-two PD patients with a disease duration <2 years and without history of present or past therapy with pro-dopaminergic agents were included and underwent the Apathy Evaluation Scale (S-AES), a clinical interview based on diagnostic criteria for apathy and a comprehensive neuropsychological battery to assess memory, frontal functions and visuospatial functions. Two years after the first assessment, all patients were re-evaluated on the S-AES, a clinical interview and neuropsychological tests. RESULTS: According to the cut-off value of the S-AES and diagnostic criteria for apathy, eight patients experienced apathy at both baseline and follow-up (A+A+), nine patients had apathy only at follow-up (A-A+), 37 patients never experienced apathy (A-A-) and eight patients showed apathy at the baseline only (A+A-). Cognitive performance significantly declined in all four groups. At both baseline and follow-up A+A+ performed worse than A-A- on visuospatial and frontal tests; A-A+ had lower scores than A-A- on the interference task of the Stroop test (IT-ST). Regression analysis showed that poor performance on the IT-ST at baseline was the only independent predictor of onset of apathy at follow-up. CONCLUSIONS: The results indicated a relationship between apathy and dysexecutive syndrome in early PD. Reduced scores on the IT-ST may predict development of apathy in PD patients.

Calmodulin distribution and the actomyosin cytoskeleton in Toxoplasma gondii.

The gliding motility of the protozoan parasite Toxoplasma gondii and its invasion of cells are powered by an actin-myosin motor. We have studied the spatial distribution and relationship between these two cytoskeleton proteins and calmodulin (CaM), the Ca(2+)-dependent protein involved in invasion by T. gondii. A 3D reconstruction using labeling and tomographic studies showed that actin was present as a V-like structure in the conoidal part of the parasite. The myosin distribution overlapped that of actin, and CaM was concentrated at the center of the apical pole. We demonstrated that the actomyosin network, CaM, and myosin light-chain kinases are confined to the apical pole of the T. gondii tachyzoite. MLCK could act as an intermediate molecule between CaM and the cytoskeleton proteins. We have developed a model of the organization of the actomyosin-CaM complex and the steps of a signaling pathway for parasite motility.

Transcutaneous pacing.

Transcutaneous pacing is a safe and effective treatment for use in a variety of emergent and nonemergent situations. Large anterior and posterior skin electrodes transmit electrical current through the thorax in an attempt to stimulate myocardial contraction. Advantages include its safe and effective use, timeliness and ease of initiation, and economical value. Revisions of the former models allow for improved comfort for the patient; however, many patients continue to find the sensation unacceptable. In the critical care environment, transcutaneous pacing has several implications for nursing.