The opsonic fragment of the third component of human complement (C3)

Human peripheral blood phagocytes ingest Escherichia coli 026:B6 lipopolysaccharide (LPS)-coated paraffin oil droplets containing Oil red O only if fresh serum deposits C3 on the surfaces of the particles (opsonizes them), by reactions involving the properdin system. The rate of binding of purified [125-I]C3 in serum to LPS-coated particles correlated precisely with the rate of acquisition of ingestibility assayed spectrophotometrically. Once opsonized, LPS-coated particles remained fully ingestible and retained fixed [125-I]C3 radioactivity even after exposure to extremes of temperature, pH, ionic strength, phospholipases, urea or guanidine, some nonionic and ionic detergents, and organic solvents. Trypsin, human conglutinogen-activating factor, another heat-stable activity found in human serum, and sodium dodecyl sulfate removed radioactivity and diminished ingestibility of the opsonized particles. Alkylation, reduction plus alkylation and F(ab')2 from anti-C3 blocked ingestibility but did not alter particle-bound radioactivitymelectrophoretic and tryptic peptide autoradiographic analysis of dodecyl sulfate eluates of opsonized particles, cleansed of many contaminating proteins by boiling with 2 M NaCl (yet still opsonized), revealed that the polypeptide with C3-derived radioactivity had a mol wt of approximately 140,000 and was composed of 70,000 mol wt subunits linked by disulfide bonds. Immunochemical analysis and comparison of the peptide structure of the eluate with that of C3 indicated that the opsonic fragment is not the fragment defined as C3b but a smaller derivative of C3.     

Strategies used by families to simplify tasks for individuals with Alzheimer's disease and related disorders: psychometric analysis of the Task Management Strategy Index (TMSI)

PURPOSE: Little is known about the specific behavioral strategies used by families to manage the physical dependency of persons with Alzheimer's disease and related disorders (ADRD). This study reports the psychometric properties of the Task Management Strategy Index (TMSI), a measure designed to identify actions taken by caregivers to simplify everyday self-care tasks for persons with ADRD. Relationships between use of these strategies and caregiver and care-recipient characteristics were also examined. DESIGN AND METHODS: A pool of 20 items was developed and initially tested with 202 family caregivers (Sample 1) recruited for a dementia-management intervention study. Principal axis factor analysis was performed to determine scale structure. Convergent and discriminant evidence was examined using Pearson cor-relation and multiple regression analyses with a separate sample of 255 family caregivers (Sample 2) recruited for the Philadelphia site of the National Institutes of Health multisite initiative, Resources for Enhancing Alzheimer's Caregiver Health. RESULTS: Exploratory principal axis factoring yielded one general factor accounting for 60.2% of variance in the first sample. Nineteen items, loading at.3 or above, constituted the final scale (Cronbach's alpha =.81 in Sample 1 and.74 in Sample 2). In Sample 2, TMSI scores were significantly associated with greater functional dependency of ADRD patients, high self-efficacy, and greater use of positive coping strategies. As expected, caregiver upset with disruptive behaviors and caregiver use of criticism-based strategies were not associated with TMSI scores. Higher caregiver education was significantly associated with greater use of task strategies. IMPLICATIONS: Results provide preliminary evidence that the TMSI is an easily administered, reliable, valid scale. Caregivers with lower education may benefit from instruction in the use of these strategies.     

Distinct Wilson's disease mutations in ATP7B are associated with enhanced binding to COMMD1 and reduced stability of ATP7B

BACKGROUND & AIMS: Wilson's disease (WD) is characterized by hepatic copper overload and caused by mutations in the gene encoding the copper-transporting P-type adenosine triphosphatase (ATPase) ATP7B. ATP7B interacts with COMMD1, a protein that is deleted in Bedlington terriers with hereditary copper toxicosis. Here we characterized the implications of the interaction between COMMD1 and ATP7B in relation to the pathogenesis of WD. METHODS: Glutathione-S-transferase pull-down experiments, co-immunoprecipitations, immunofluorescence microscopy, site-directed mutagenesis, and biosynthetic labeling experiments were performed to characterize the interaction between COMMD1 and ATP7B and the effects of WD causing mutations. RESULTS: COMMD1 specifically interacted with the amino-terminal region of ATP7B. This interaction was independent of intracellular copper levels and of the expression of the copper chaperone ATOX1. Four WD patient-derived mutations in this region of ATP7B significantly increased its binding to COMMD1. Two of these mutations also resulted in mislocalization and increased degradation rate of ATP7B. Although COMMD1 did not affect copper-induced trafficking of ATP7B, it markedly decreased the stability of newly synthesized ATP7B. CONCLUSIONS: Our data implicate COMMD1 in the pathogenesis of WD and indicate that COMMD1 exerts its regulatory role in copper homeostasis through the regulation of ATP7B stability.     

Fluphenazine levels during maintenance treatment of recent-onset schizophrenia: relation to side effects, psychosocial function and depression

Rationale: The utility of fluphenazine levels during maintenance treatment of schizophrenia is still unclear. Objectives: This study investigated the relationship between fluphenazine levels and a variety of clinical measures during maintenance treatment of schizophrenia. Methods: Fluphenazine levels, side effects, depression and psychosocial outcome were measured at five time points over approximately 1 year in 59 recent onset schizophrenic patients treated with a maintenance dose of injectable fluphenazine decanoate. Negative symptoms were evaluated at the 1-year endpoint. Results: Fluphenazine levels showed marked intraindividual variability even when measurements were restricted to the second 6 months of treatment, by which time steady state levels should have been achieved. No consistent relationship was found between fluphenazine levels and any of the outcome measures. Conclusions: The results of this study suggest that fluphenazine plasma levels do not routinely add relevant clinical information beyond that of dose in evaluating potential side effects or negative consequences during maintenance treatment with the decanoate form of the medication. Received: 28 January 1999 / Final version: 20 September 1999