Alteration by phosphatidyl serine of tension responses and 45Ca distribution in aortic smooth muscle

The effects of phosphatidyl serine (PS) on 45Ca distribution, 45Ca movements and contractions were examined in rabbit aortic smooth muscle. Contractile responses to submaximal concentrations of norepinephrine and histamine were potentiated by prior exposure to PS, but equivalent responses to potassium were unaffected. Addition of PS to the incubation solution decreased 45Ca uptake; exposure of aortic strips to PS during washout of either 45Ca or promethium (147Pm) resulted in maintained increases in efflux. These PS-induced alterations in net loss of 45Ca or 147Pm can be attributed to a decreased membrane reuptake and/or rebinding. However, the presence of PS during the washout significantly reduced the increases in 45Ca efflux rate elicited with either 0.05 mM concentrations of Ca++ or ethylenediamine tetraacetic acid. Thus, in rabbit aortic smooth muscle, exogenous PS can alter the availability and/or exchangeability of a membrane-bound Ca++ fraction. By specifically increasing the affinity for Ca++ at relevant membrane sites or stores. PS may enhance the ability of vascular smooth muscle to respond to stimulatory agents that mobilize Ca++ from these sites and, in this manner, potentiate contractile responses.     

In vitro activity of guinea pig transfer factor released into plasma

Plasma fractions and plasma dialysate from 2,4-dinitrochlorobenzene- and tuberculin-sensitive guinea pigs that had been treated with either antilymphocytic serum or normal control serum were analyzed for their ability to transfer lymphocyte transformation, passive cutaneous anaphylaxis, and macrophage migration inhibition, as well as delayed hypersensitivity in vivo. Antilymphocytic serum caused rapid release of material, which has characteristics of transfer factor, into the plasma. It was dialyzable, migrated electrophoretically with the alpha globulins and albumin, possessed a 280/260 (nm) optical density ratio of 0.7, and caused in vitro lymphocyte transformation in the presence of the specific antigen. Passive cutaneous anaphylaxis antibodies were also present in the plasma of sensitive animals, but they were isolated in electrophoretic or dialysis fractions separate from those containing transfer activity.     

Schistosoma mansoni: an enkephalinergic system that may participate in internal and host-parasite signaling

The present study is concerned with an opioid system in the human trematode Schistosoma mansoni, both as part of the endogenous chemical messenger system and as a tool in the parasite reaction to the host(s). A high-affinity opioid binding site was characterized in membrane suspensions prepared from adult worms. Scatchard analysis revealed a single class of receptors with a dissociation constant of 1.8 nM and a Bmax of 24.9 pmol/g protein for (D-Ala2, Met5)-enkephalin (DAME). The displacement experiments demonstrated that the most potent ligands were beta-endorphin, DAME, and met-enkephalin. These characteristics and the effects of various ions on DAME affinity suggest that S. mansoni has a delta-like opioid receptor, as previously described in other invertebrates. A met-enkephalin-like peptide was also characterized in a miracidial extract. Radioimmunoassay, reverse-phase HPLC, and bioassay by induction of cell conformational changes of human polymorphonuclear leukocytes revealed that the parasite peptide is very similar to authentic met-enkephalin. A met-enkephalin-like peptide was also shown to be present in adult worms and in their incubation medium. Taken together, these observations demonstrate the existence of a complete opiate system in S. mansoni. We discuss its role in molecular signaling within the parasite and in host-parasite interactions.     

What health professionals can do to identify and resolve patient dissatisfaction

BACKGROUND: Patient satisfaction affects consistency of self-care, health outcomes, level of service utilization, choice of health professionals, and decisions to sue in the face of adverse outcomes. Understanding patients' specific dissatisfactions may help health professionals and administrators identify and rectify organizational deficiencies before they become costly. COMMON CAUSES OF COMPLAINTS: As part of a series of research projects, more than 12,000 patient/family complaint narratives were examined in which patients or patients' family members told interviewers or patient advocates about the care they received from their health professionals in both inpatient and outpatient settings. Complaints may be categorized as involving issues of care and treatment, communication, humaneness, access and availability, environment, and billing/payment. STRATEGIES FOR RESOLVING COMPLAINTS: Even though caregivers may not have control over all the factors that lead to dissatisfaction, they can often hear and address complaints. As a result, they may not only contribute to quality of care but improve the systems in which they practice. The challenges are how to prevent dissatisfaction in the first place, and, if it does occur, to identify and if possible rectify patient concerns. Three case studies are provided. CONCLUSION: All health professionals must be involved in efforts to resolve problems that compromise patient care. Some problems could be prevented if administrators and leaders used complaint data to recommend new policies and procedures or to identify and counsel with health care team members who generate disproportionate numbers of complaints. If all are involved in both prevention and problem solving, resources devoted to uncovering, understanding, and resolving patient complaints are likely to prove cost-effective.     

Does age of the host affect growth rates of skeletal malignancies?

Statistical analysis of bone tumor growth rates as a function of age at initiation of radiation-induced skeletal malignancies in our animal colony indicated that the p value for an association between these parameters was <0.05, suggesting a correlation in beagle dogs. The youngest animals appeared to exhibit the most slowly growing tumors, and the trend was toward more rapidly growing tumors with increasing age. Less effective immune systems in older animals were invoked as a possible explanation of this relationship.