Immunization of healthy adults with a single recombinant pneumococcal surface protein A (PspA) variant stimulates broadly cross-reactive antibodies to heterologous PspA molecules.

Pneumococcal surface protein A (PspA) is a highly variable protein found on all strains of pneumococci. To be successful, a PspA-based vaccine for S. pneumoniae must induce antibodies that are broadly cross-reactive. To address whether cross-reactive antibodies could be induced in man, we evaluated serum from adults immunized with recombinant clade 2 PspA from strain Rx1. Immunization with 5-125 microg rPspA lead to a significant increase in circulating anti-PspA antibodies, as well as antibodies reactive to heterologous rPspA molecules. Increased binding of post-immune sera to 37 pneumococcal strains expressing a variety of PspA and capsule types was observed, versus pre-immune sera. The extent of cross-clade reactivity of human anti-rPspA followed roughly the amount of sequence homology to the non-clade 2 antigens. It is hypothesized that priming of humans by natural exposure to S. pneumoniae contributes to the breadth of the cross-reactivity of antibody to PspA.

Optimizing resuscitation outcomes with pharmacologic therapy.

Pharmacologic therapy plays a key role in the emergency resuscitation of patients with cardiac arrest. The Advanced Cardiac Life Support guidelines sanctioned by the American Heart Association provide flexible treatment protocols (algorithms) that serve as a valuable tool for clinicians. Vasoactive (vasopressive) therapy with epinephrine is of primary importance in all patients with nonperfusing rhythms (for example, ventricular fibrillation [VF], pulseless ventricular tachycardia [VT], electromechanical dissociation [EMD], and asystole) because it raises myocardial and cerebral perfusion pressures, thereby increasing the likelihood of successful resuscitation. Antiarrhythmic drugs play a secondary role to electrocardioversion in the treatment of VF and pulseless VT. Despite continued investigation and recent advances in our understanding of the role of drugs and other therapeutic interventions, the short-term and long-term prognoses of patients with cardiac arrest, especially out-of-hospital arrest, remain dismal. Clearly, much study into the prevention and treatment of sudden cardiac death is desperately needed.

Forgotten variables in memory theory and research.

Memory research, like other scientific research, disregards many variables in order to bring the full force of the scientific method to bear on clearly important variables. The reasons why memory research attends to certain variables and disregards others emanate largely from theoretical assumptions that distinguish memory systems from other psychological systems, and that distinguish variables intrinsic to memory from those extrinsic to memory. Nevertheless, a number of these 'forgotten' variables affect memory performance. Regardless of past practice, it is a mistake for memory research to continue to ignore relevant variables. Doing so introduces measurement error that contaminates memory performance measures, and classification error that precludes the discovery of legitimate memory variables. It is proposed here that if forgotten memory variables are controlled, manipulated, and measured more extensively, then future memory research will have greater power and memory theories will have greater validity.

Semantic relations as graded concepts.

This experiment tests the hypothesis that semantic relations are graded concepts. It also tests the predictions of relation element theory and of Klix's (1986) theory of semantic relations regarding possible predictors of graded structure for semantic relations. Results support the hypothesis that semantic relations have graded structures, and indicate that differences among relations in gradedness reflect the families of semantic relations described by Chaffin & Herrmann (1984). In addition, Klix's distinction between property relations and event relations appears to be useful in explaining differences among relations in graded structure.

Gender-linked differences in everyday memory performance.

Recent research has demonstrated that people hold beliefs about how well others perform everyday memory tasks according to another's sex. For example, meta-memory ratings indicate that other men and other women are believed to differ in their success at performing certain memory tasks (Crawford, Herrmann, Holdsworth, Randall & Robbins, 1989). In the present study, two experiments investigated whether gender stereotypes concerning everyday memory have any validity. Experiment 1 presented female and male subjects with two tasks that the aforementioned meta-memory ratings had shown are implicitly gender marked: learning a shopping list (a sterotypically feminine task) and learning directions to go to a particular place (a stereotypically masculine task). The results were consistent with the gender stereotypes, i.e. women recalled more of the shopping list than men whereas men recalled more of the directions than women. The second experiment investigated whether memory performance would be influenced by mere changes in the label of materials in memory tasks to be biased toward male or female gender background: labelling a shopping list as pertaining to 'groceries' or to 'hardware store'; and a set of directions to 'make a shirt' or to 'make a workbench'. The results also indicated that memory performance varied in ways consistent with gender stereotypes.

Quantitation of human IgG subclass antibodies to Haemophilus influenzae type b capsular polysaccharide. Results of an international collaborative study using enzyme immunoassay methodology.

An international collaborative study was conducted at ten sites to examine the performance of enzyme immunoassays (EIAs) for the quantitation of IgG1, IgG2, IgG3, IgG4 and total IgG anti-Haemophilus influenzae type b (Hib) capsular polysaccharide in human serum. All groups used the same reagents: microtiter plates coated with polyribosylribitol phosphate (PRP) conjugated to poly-L-lysine (PLL), reference, control and test human sera, biotin-conjugated International Union of Immunological Societies (IUIS)-documented monoclonal anti-human IgG1-4 and IgG Pan detection antibodies, avidin-peroxidase and TMB substrate. Initial mixing of soluble PRP antigen or an equal volume of buffer with the 20 test sera prior to analysis confirmed PRP antigen specificity in all five EIAs with greater than 80% competitive inhibition at most sites. Positive correlation between the total IgG anti-Hib and sum of IgG1-4 anti-Hib was demonstrated (r2 = 0.99, Y = 1.13X -0.15). Good agreement was shown between the total IgG anti-Hib as measured by EIA and the total Hib-specific antibodies measured by the current radiolabeled antigen binding assay (r2 = 0.97, Y = 4.6X -5.8). Assay parallelism was demonstrated with an average interdilutional %CV of 22% and parallel dose-response curve slopes. The interdilutional %CVs were calculated as an average per sample of the variation of microgram/ml (corrected for dilution) at different dilutions per laboratory for all participating sites. The interlaboratory variation was the only performance parameter studied that exceeded the target level of 35% CV in all IgG1-4 and total IgG anti-Hib assays. IgG subclass distributions in the test sera demonstrated a predominance of IgG1 anti-Hib in the pediatric serum pools and IgG2 anti-Hib in the adult sera, with low but detectable levels of IgG3 and IgG4 anti-Hib in each group.

The representational bias of acquired memory processes.

The notion that some memory processes are acquired has been around for at least two thousand years. However, acquired memory processes have been made the object of scientific investigation in only the past two decades. Traditionally, psychologists have assumed that acquired memory processes are equally effective across the entire range of memory tasks. This article reviews research that has investigated whether these processes are equally effective across tasks or are more effective for just certain tasks. The review indicates that most, if not all, acquired memory processes are biased to deal effectively just certain kinds of mental representation. The article proposes that these processes are representationally biased because (1) they activate basic memory processes (e.g. imagery, rehearsal) which themselves are biased to process certain representational attributes and because (2) their use of basic processes follows a sequence required by particular memory tasks. Increased understanding of the representational bias of acquired processes may be seen to enable better control of memory performance and to foster more powerful investigations of memory phenomena.

Retrieval and comparison processes in part--whole decisions.

Undergraduate students were presented with word pairs (e.g., egg-yolk) and were timed as they decided whether one word named part of the thing named by the other word. In Experiment 1, "no" responses to nonpart pairs (e.g., fish-flaps) were slowed by the similarity of the stimulus part (flaps) to a part that the stimulus object did possess (fins). This suggested that decisions were made by retrieving parts of the stimulus object from memory and comparing them to the stimulus part. Whereas the parts used as stimuli in Experiment 1 were nonspecific, belonging to several different types of object (e.g., wheel), those selected for Experiment 2 were specific to a single type of object (e.g., thumb). In Experiment 2, "no" responses to nonpart pairs (e.g., foot-thumb) were slowed by similarity of the stimulus object (foot) to an object that the stimulus part (thumb) belonged to (hand). This suggested that decisions were made by retrieving the object to which the stimulus part belonged and comparing it to the stimulus object. The results support a hybrid model of part-whole decisions that includes directed retrieval of relational knowledge from memory and a comparison process.

Effects of relation similarity on part-whole decisions.

Subjects were presented with word pairs (e.g., bed-mattress) and timed as they decided whether one word named part of the item named by the other word. Yes responses were facilitated, and no responses were impeded, by relation similarity (i.e., the similarity of the relation between the two stimulus items to the part-whole relation). Item similarity, the similarity of the two stimulus items to each other, had no effect. The results support the view that similarity effects in semantic decision tasks are due to the comparison of elements of the relation between the two stimulus words against relation elements that serve as criteria for the target relation that the subject has been asked to identify.

Antibody responses to meningococcal polysaccharide vaccine in adults without a spleen.

Asplenic persons are at risk for the development of overwhelming sepsis from certain encapsulated bacteria, including meningococci. Since it is not known if asplenic persons can have antibody responses, this study compared such responses following bivalent groups A and C meningococcal polysaccharide vaccine in 22 asplenic subjects and healthy control subjects. There were no adverse reactions to the vaccine. Antibody responses were measured using a solid-phase radioimmune assay; results were compiled for both seroconversions and changes in mean antibody titers of IgG, IgA, and IgM classes. Subjects who underwent splenectomy for trauma and control subjects with spleens showed a polyclonal antibody response to both vaccine antigens. Those persons who underwent splenectomy for nonlymphoid tumors had nearly as good a response as normal subjects. By contrast, asplenic subjects with lymphoid tumors who had received prior chemotherapy and radiotherapy had poor responses to both antigens. It is concluded that meningococcal vaccine is immunogenic in asplenic persons, with the aforementioned exceptions, and that this vaccine should be routinely administered to such persons.

Handedness and the mental rotation of perceived patterns.

The present experiment investigated the effect of hemispheric dominance, as indicated by handedness, and perceptual processing. Displays containing two visual patterns were presented to right- and left-handed subjects who classified the two patterns as being the same or different. Also the two patterns in a display were in either an identical orientation or nonidentical orientations. Overall, left handers were faster than right handers at the "same-different" judgement. Additionally, latency increased with the angular discrepancy in orientation between patterns for both handedness groups but this increase was smaller for left handers than for right handers. Apparently, left handers evaluate overall perceptual similarity faster than right handers and they also mentally rotate perceived patterns of discrepant orientations faster than right handers. These findings contradict previous generalizations that left handers are deficient perceptually. Moreover, the present results support the position that left handers should be faster at global perceptual tasks because left handers have less neural distance than right handers mediating the transmission of information between the locus of perception and the locus of dominance.

Familiarity and organization of category terms in semantic memory.

In order to determine production frequencies for various category terms, 219 college students were asked to generate category terms (e.g. Automobiles, Vegetables, Relatives) during a 4-rain period. The production frequency (i.e., the number of subjects who listed a particular term) for a given category term may be considered as reflecting the familiarity or amount of usage of that category term, and, as such, should be of value to memory researchers in designing experiments. Additionally, examination of the order in which terms were produced showed that subjects "clustered" related category terms, (e.g., "Countries" and "States" were often produced successively). This clustering of category terrms is supportive of the hypothesis that categories are organized in semantic memory in some kind of higher order structure.

Cross-category structure in semantic memory.

In Experiment I, subjects made similarity judgments about all 56 category terms listed in the Battig and Montague (1969) norms. These judgments were then subjected to a hierarchical clustering analysis. Experiment II demonstrated that the relations among the category labels are very similar to the relations among the high dominance exemplars of these categories. Experiment III showed that the distances between the category terms in the hierarchical clustering analysis could predict RTs in a same-different paradigm.