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Biomedical subjects

B Caplan

Publications and source records attributed to B Caplan.

18 recordsLinked to original sources
PubMed1992

Comparative analysis of the immunostimulatory properties of different adjuvants on the immunogenicity of a prototype parainfluenza virus type 3 subunit vaccine.

The immunogenicity of a parainfluenza virus type 3 (PIV-3) subunit vaccine consisting of affinity-purified haemagglutinin-neuraminidase (HN) and fusion (F) surface glycoproteins was tested in guinea-pigs and hamsters. The ability of several different immunopotentiating agents to enhance the antibody response of animals to the PIV-3 surface glycoproteins was evaluated. The immunity induced by HN and F alone was compared with the response elicited by purified proteins combined with Freund's complete adjuvant, aluminium phosphate, Syntex's threonyl-muramyl dipeptide (MDP) SAF-MF formulation, or Ribi's adjuvant formulation containing BCG cell wall skeleton (CWS), trehalose dimycolate (TDM) and monophosphoryl lipid A (MPL) in a 2% squalene-in-water emulsion. Purified proteins were also incorporated into three different liposome formulations prepared by the detergent dialysis procedure. Immunization of guinea-pigs and hamsters with two 15 micrograms doses of the PIV-3 surface glycoproteins administered in the absence of adjuvant elicited high haemagglutination inhibition, neutralization and anti-fusion titres. The liposome preparations failed to enhance the antibody titres. Ribi's adjuvant formulation was effective at inducing a good secondary response to the purified proteins while the immunostimulatory effects of aluminium phosphate, Syntex and Freund's adjuvants were clearly demonstrated in both primary and secondary responses. When administered without adjuvant, a 15 microgram dose of the HN and F mixture was capable of protecting hamsters against live virus challenge. The immunoprotective dose of the purified proteins could be reduced to at least 0.1 microgram by the addition of aluminium phosphate, Syntex or Freund's adjuvants.

Adjuvants, Immunologic↗
PubMed1991

Evaluation of the immunogenicity and protective efficacy of a candidate parainfluenza virus type 3 subunit vaccine in cotton rats.

A parainfluenza virus type 3 (PIV3) subunit vaccine consisting of detergent-solubilized, affinity-purified haemagglutinin-neuraminidase (HN) and fusion (F) surface glycoproteins was tested in cotton rats for immunogenicity, short-term effects on virus-induced immunopathology and protective efficacy. Groups of animals were immunized twice, 4 weeks apart, with graded doses of vaccine administered either alone or with aluminium phosphate (AlPO4). The minimum immunogenic dose of vaccine was 0.1 microgram HN and F when the vaccine was given alone and 0.01 microgram when the vaccine was administered with AlPO4 adjuvant. Antibody responses in animals immunized with 1 microgram HN and F mixed with adjuvant were similar to those in control animals infected with live PIV3 intranasally. Pulmonary and nasal wash PIV3 titres generally were inversely correlated with serum antibody levels. Virus titres were significantly reduced in all groups of animals immunized with greater than or equal to 0.1 microgram HN and F compared with control animals immunized with vehicle only. Four days after virus challenge, there was no evidence of enhanced histopathology in lung sections from animals immunized with the candidate vaccine.

Adjuvants, Immunologic↗
PubMed1990

Clinical applications of the Matching Familiar Figures Test: impulsivity vs. unilateral neglect.

Impulsivity is a common consequence of brain damage, one with negative prognostic implications. To attempt to study the incidence of impulsivity after lateralized cerebral lesions, 93 patients (50 RBD, 43 LBD) and 24 normal controls were administered the Matching Familiar Figures Test, a visual match-to-sample task in a multiple-choice format. The groups differed significantly (RBD less than LBD less than Controls) with respect to accuracy (visual-perceptual skill). Average response latency scores of the brain-damaged groups were slightly, but not significantly, lower than that of Controls. Although more than one-third of the RBD showed a tendency to respond rapidly, reduced response latency in RBD patients may be due, not to impulsivity per se, but, rather, to incomplete visual scanning characteristic of neglect. The present results illustrate the hazards of interpreting neuro-psychological test scores without consideration of pertinent processing variables.

Aged↗
PubMed1987

Assessment of unilateral neglect: a new reading test.

A new reading test, designed to detect left-sided visual neglect, was administered to 66 patients with unilateral lesions. As expected, the group with right-hemisphere involvement had a considerably higher incidence of impaired performance; only subjects in this group exhibited severe neglect. In general, subjects who showed neglect on the reading test also did so on visual-perceptual tasks. However, in some instances neglect surfaced only on the former. This instrument appears to be a valuable screening measure, and it also has potential as a retraining tool.

Aged↗
PubMed1987

Multiple memory systems: evidence from stroke.

In this report, we describe the "fractionation of memory systems" in a 62-yr.-old woman following a left anterior stroke. Despite the presence of a significant, persistent declarative memory (verbal learning) deficit, this patient exhibited relatively intact procedural learning. The latter was manifested over a 4-day period by improved performance on a maze task executed under "mirror-tracing" conditions. By the final set of trials, the patient's performance approximated that of a normal control subject with respect to speed, although not errors. The selective preservation of particular learning abilities in brain-damaged patients has implications for rehabilitative interventions.

Brain Damage, Chronic↗
PubMed1986

[Effects of enflurane and halothane on hepatic function in biliary surgery].

The effects of two volatile anaesthetics on hepatic function are compared in 80 patients in hepato-biliary surgery. 40 patients were anaesthetized either with enflurane or halothane. This study is based on the variations of blood levels of gamma GT, bilirubin, SGOT SGPT, alkaline phosphatase, L.D.H. Samples were taken the day prior to the operation, one, two and five days afterwards. The results show an increase in the levels of BD, SGPT, LDH no 5, less important with enflurane than with halothane, and mainly in patients with preoperative hepatic abnormalities. Enflurane appears to be preferable in such cases.

Adult↗
PubMed1985

Stimulus effects in unilateral neglect?

Unilaterally brain-damaged subjects and normal controls were administered parallel verbal and nonverbal forms of a visual cancellation task. The attentional theory of unilateral neglect, which predicts less manifest neglect on tasks that preferentially engage the damaged hemisphere, was not supported. Subjects who exhibited neglect did so to a comparable degree on both verbal and nonverbal tasks. The data are consistent with a model of right hemisphere dominance for attention across the visual field.

Aged↗
PubMed1984

Stressful sequelae of disabling illness.

Fifty former rehabilitation patients completed the recent life changes questionnaire (RLCQ), an inventory of potentially stressful life events. Subjects indicated those that had occurred to them during the 6 months prior to onset of illness/injury and during the 6 months following hospital discharge. Certain RLCQ items have associated point values ("life change units" or LCU) indicative of the amount of stress induced by that event. The average number of LCU reported for the post-discharge period exceeded by 3 1/2 times the average for the pre-injury epoch. Ranges for both sets of values were substantial. Forty-five of the fifty-seven events were reported more frequently for the later period, while eight occurred slightly more often before the onset of illness or injury. These findings have implications for the genesis, frequency, magnitude and individual variability of depression following the onset of disabling illness.

Adjustment Disorders↗
PubMed1984

High-level secretion of interleukin 2 by a subset of proliferating thymic lymphoblasts.

We have characterized the thymocytes that can be induced to secrete interleukin 2 (IL 2) after polyclonal stimulation with Con A. For maximal activation, an important adjunct to the Con A is the phorbol ester TPA. In the presence of TPA, IL 2 production by thymocytes is relatively independent of adherent accessory cells; this allows us to compare the abilities of different thymic subpopulations to make IL 2. The most numerous class that includes IL 2 producers is made up of cells with a typical "medullary" population, the phenotype: moderately small, postmitotic cells that fail to bind peanut agglutinin. In addition, however, a population of large, proliferating lymphoblasts is competent in IL 2 production directly as isolated. Relative to the total "medullary" population, the lymphoblasts are enriched for the ability to make IL 2. They account for a significant proportion of the total IL 2 produced by thymocytes, and demonstrate that this aspect of immunocompetence is not restricted to cells that have finished their intrathymic proliferation. The IL 2-producing lymphoblasts do not bind peanut agglutinin or express thymus-leukemia antigen, but they do express high levels of Lyt-1. Although distinct from most medullary thymocytes, therefore, they are also distinct from the majority of cortical blast cells for which a direct precursor role has been established. They may be a subset of the rare proliferating blast cells in the medulla. Further heterogeneity in the thymic IL 2 producers is demonstrated by their expression of the Lyt-2 glycoprotein. The majority of IL 2 producers are Lyt-2- as are the majority of peripheral T "helper" cells. However, a distinct minority of the thymic IL 2 producers express Lyt-2. Therefore, the ability of some peripheral Lyt-2+ cells to secrete IL 2 may be determined at the time of their initial programming in the thymus.

Animals↗