聚氯乙烯增塑糊流变行为的研究——Ⅳ.表面活性剂的影响

本文研究了各类表面活性剂对聚氯乙烯增塑糊流变行为的影响。阴离子表面活性剂使其增塑糊有较高致流值,呈明显假塑性流动;阳离子和非离子表面活性剂使其增塑糊有低的表观粘度,接近牛顿型流动。测定了聚氯乙烯粒子表面的Zeta电位和接触角,并讨论了表面活性剂影响增塑糊流变性能的机理。     

An immunohistochemical study of MAP2 and clathrin in gerbil hippocampus after cerebral ischemia

Changes in MAP2 and clathrin immunoreactivity were studied in gerbil hippocampus after transient cerebral ischemia. MAP2 immuno-reactivity decreased significantly by 1 h in the subiculum-CA1 and CA2 areas which correspond to reactive change, while no decrease was observed in CA1 until day 4. Before the initiation of delayed neuronal death, MAP2 immunoreactivity was not changed in CA1. On the other hand clathrin immunoreactivity increased in the pyramidal cell layer of CA1 by 3 h after ischemia and remained high for 2 days. Clathrin immunoreactivity in the pyramidal cell layer of CA1 diminished after delayed neuronal death. The transient change of clathrin was noted especially in CA1 in the period prior to delayed neuronal death. These results imply an abnormal change in clathrin turnover after ischemia, which may participate in the pathogenesis of delayed neuronal death.     

Predictors of Paternal Versus Maternal Stress in Families of Children With Neural Tube Defects

This study examined the types of stress experienced by maternal and paternal caretakers of children with Neural Tube Defects (NTD) and examined child and family characteristics that correlated with stress. Participants were 71 two-parent families of a child with spina bifida. Parents completed the Parenting Stress Index-Short Form to measure types of stress. Additional measures were completed to investigate variables potentially related to reported stress. Fathers reported significantly higher levels of stress from “dysfunctional parent-child interaction.” Mothers' personal stress correlated with disability and medical characteristics of the child. Fathers reported more stress when the child had maladaptive behaviors and when experiencing fewer social supports and resources. Mothers and fathers coparenting a child with NTD have both common and unique stresses. It is important that both be included in parent support and education initiatives.     

A Retrospective Review of the Use and Safety of Droperidol in a Large, High-risk, Inner-city Emergency Department Patient Population

Droperidol (DROP) is used in the emergency department (ED) for sedation, analgesia, and its antiemetic effect. Its ED safety profile has not yet been reported in patients (pts). OBJECTIVES: To document the use of DROP in high-risk pts (those with head injury, alcohol or cocaine intoxication, and/or remote or recent seizures), and to determine the number of serious and minor adverse events (AEs)-seizures, hypotension, extrapyramidal side effects (EPSEs)-after DROP. METHODS: The ED database (EmSTAT) was queried to determine who received intramuscular or intravenous DROP in the ED in 1998; further chart review was done if the patient was considered high risk for or had experienced an AE. Multiple regression analysis using a random-effects model determined the significance of each variable in the occurrence of AEs. RESULTS: 2,468 patients (aged 20 months to 98 years; 112 < or =17 years; 141 > or =66 years) received DROP for agitation (n = 1,357), pain (1,135), anxiety (99), vomiting (173), or other reasons (50). There were 945 pts considered high risk; 933 charts were reviewed (DROP mean dose 4.1 +/- 2.0 mg); of these, 50 patient visits did not meet the criteria for high risk. There were 622 pts with head trauma (401 with alcohol use), including 47 with computed tomography (CT) scans positive for brain injury, 64 with cocaine use, and 197 with recent or remote seizures (137 with alcohol use). Minor AEs such as transient hypotension occurred in 96 pts after DROP (73 with alcohol use); 20 received intravenous fluids, while an additional 28 pts (8 with alcohol use) received rescue medications for EPSEs. Six possible serious AEs occurred in pts with serious comorbidities; 2 cases of respiratory depression, 3 post-DROP seizures, and 1 cardiac arrest (resuscitated) 11 hours after DROP in a cocaine-intoxicated pt (normal QT interval). There was no significant difference among high-risk groups in the occurrence of AEs. CONCLUSIONS: The vast majority of pts who received DROP in the ED did not experience an AE. A few serious AEs were noted following DROP in patients with serious comorbidities; it is not clear that DROP was causative.     

Altered genetic response to beta-adrenergic receptor activation in late passage C6 glioma cells.

Previous studies have demonstrated variability in the phenotype of rat C6 glioma cells. In the present study, we compared morphology, growth rate, and beta-adrenergic regulation of gene expression in early (P39-47) and late (P55-90) passage C6 cells. Morphological changes were observed in five independently derived, late passage populations. In four of the five, the untreated cells were more polygonal than the fibroblast-like parental cells, and only a small fraction exhibited process outgrowth after dbcAMP treatment. Untreated cells from the fifth late passage population had longer cytoplasmic processes than parental cells and responded to dbcAMP with further process outgrowth. All late passage populations had shorter generation times than the parental cells. In early passage cells, treatment with the beta-adrenergic agonist, isoproterenol (IPR), resulted in an increase in c-fos mRNA and a decrease in c-jun mRNA (Gu-bits RM, Yu H: J Neurosci Res, 30:625-630, 1991). Both of these immediate early gene responses were irreversibly lost between P50 and P55. Additional differences in basal or IPR-induced mRNA levels were observed for beta-APP, GFAP, NGF, and PPE, but not for a number of other mRNAs. These results are discussed in relationship to previously described differences in the ability of early and late passage C6 cells to accumulate cAMP (Mallorga P, et al.: Biochim Biophys Acta 678:221-229, 1981).     

Antipeptide antibodies against the 5-HT1A receptor.

The availability of the primary amino acid sequence for a large number of molecules provides a fruitful opportunity for their cellular localization by utilizing the procedure of antipeptide antibody formation. This procedure permits a synthetic peptide sequence to be attached to a carrier molecule for the purpose of inoculating an animal to raise specific antibodies against the selected protein sequence. In this report we describe a number of steps that can be taken to increase the likelihood that the selected peptide sequence will be specific and antigenic. In addition, we describe how the peptides are synthesized, purified and coupled to keyhold limpet hemocyanin. The preparation of the antibody and its characterization are also presented in this method report. The immunocytochemical staining at both the light and ultrastructural level with serotonin (5-HT1A) receptor antipeptide antibodies is discussed. The advantages and disadvantages of this procedure are summarized.