The oncofetal protein, 5T4, is a suitable target for antibody-guided anti-cancer chemotherapy with calicheamicin.

The oncofetal protein, 5T4, is a tumor-associated protein displayed on the cell membrane of various carcinomas. This molecule is a promising target for anti-tumor vaccine development and for targeted therapy with staphylococcus exotoxin. The potential use of 5T4 as a target for antibody-guided chemotherapy has not been demonstrated. We report oncolytic efficacy and selectivity in vitro and in vivo with immuno-conjugates of calicheamicin (CM) and the anti-5T4 antibody, H8. CM is a potent cytotoxic drug that causes double strand breaks in DNA. Conjugates of CM and H8 were constructed with acid-labile as well as acid-stabile linkers. In vitro, when applied to monolayers of 5T4(+) cells, CM-conjugates targeting 5T4 were consistently more toxic than either free drug or a non-binding control CM-conjugate. This difference was less pronounced on 5T4-deficient cells. In vivo, four 5T4-positive subcutaneous tumor models were treated with conjugates. Efficacy was demonstrated by reduction of tumor growth relative to controls treated with drug vehicle. To evidence selectivity, the efficacy of the anti-5T4 conjugates was compared to the efficacy of H8, a mixture of H8 and calicheamicin, calicheamicin alone or calicheamicin conjugated to the anti-CD33 antibody, hP67.6. In addition, the efficacy and selectivity of an acid-labile conjugate of H8 was evaluated in an orthotopic model for 5T4(+) lung cancer. Increased survival following treatment was used as a parameter of efficacy. Calicheamicin conjugates of H8 were effective and selective in all the examined tumor models. Differences in efficacy between the acid-labile and acid-stabile conjugates depended on the investigated tumor model.

Therapeutic potential of CD22-specific antibody-targeted chemotherapy using inotuzumab ozogamicin (CMC-544) for the treatment of acute lymphoblastic leukemia.

CMC-544 (inotuzumab ozogamicin) is a CD22-specific cytotoxic immunoconjugate of calicheamicin intended for the treatment of B-lymphoid malignancies. This preclinical study investigated antitumor activity of CMC-544 against CD22+ acute lymphoblastic leukemia (ALL). CMC-544 inhibited in vitro growth of ALL cell lines more potently than that of Ramos B-lymphoma cells. When administered to nude mice with established sc xenografts of REH ALL, CMC-544 caused dose-dependent inhibition of xenograft growth producing complete tumor regression and cures in tumor-bearing mice at the highest dose of 160 microg/kg of conjugated calicheamicin. In contrast, a nonbinding control conjugate was 16-fold less effective than CMC-544 in inhibiting growth of REH ALL xenografts. When REH cells were injected intravenously in scid mice and allowed to disseminate systemically, mice developed hind-limb paralysis that was effectively prevented by treatment with CMC-544. Flow cytometric analysis of cells recovered from the bone marrow from mice with disseminated disease verified the presence of engrafted ALL cells. Significantly reduced numbers of ALL cells were recovered from the bone marrow of CMC-544-treated mice than from vehicle-treated mice with disseminated disease. The anti-leukemia activity of CMC-544 demonstrated here further supports clinical evaluation of CMC-544 for the treatment of CD22+ leukemia.

Autophosphorylation of KDR in the kinase domain is required for maximal VEGF-stimulated kinase activity and receptor internalization.

We have previously reported the identification of four autophosphorylation sites on the KDR VEGF receptor. Two of these sites (tyrosines 951 and 996) are located in the receptor's kinase insert domain, and two (tyrosines 1054 and 1059) are located in the catalytic domain. In order to clarify the functional significance of these sites, we made DNA constructs in which tyrosine codons were replaced with those for phenylalanine, and expressed the DNA constructs in 293 cells. VEGF binding to cells expressing the native receptor led to a rapid increase in receptor and PLC-gamma phosphorylation, and a slower increase in the phosphorylation of p125FAK and paxillin. VEGF binding to KDR(Y951F) and KDR(Y996F) expressing cells resulted in phosphorylation of all cellular substrates tested, although the level of PLCgamma phosphorylation was decreased for KDR(Y996F). The decreased level of PLCgamma phosphorylation was not because PLCgamma-containing SH2 domains bind to the Y996 autophosphorylation site. We conclude that there exists receptor autophosphorylation sites not previously identified which allow for signaling via PLCgamma, as well as p125FAK and paxillin. VEGF binding to cells expressing KDR mutated at both tyrosine's 1054 and 1059 activated receptor autophosphorylation but at a level which was only 10% of that seen for cells expressing native receptor. Tyrosine phosphorylation of cell signaling proteins was not observed in KDR(Y1054,1059) expressing cells. Utilizing an in vitro assay which directly measures receptor catalytic activity allowed us to determine that the tyrosine kinase activity of the native receptor was significantly greater than that for the double mutant. We conclude from this result that VEGF-induced autophosphorylation at tyrosines 1054 and 1059 is a required step for allowing maximal KDR kinase activity. Maximal rates of receptor kinase activity is required for VEGF-induced receptor internalization, as internalization was delayed in the KDR(Y1054,1059F) expressing cells when compared to cells expressing native receptor.

Right hemisphere involvement in depression: toward a neuropsychological theory of negative affective experiences.

Several lines of inquiry provide converging evidence for a critical role for the right cerebral hemisphere in negative affective experiences. This research includes the assessment of affective consequences of both focal cerebral lesions and pharmacological inactivation of one or the other hemisphere, as well as experimental and physiological techniques assessing differential hemispheric activation. The specific nature of right hemispheric involvement is conceptualized as a tendency to become activated by aversive experiences, and once activated, to process stimuli in a manner consistent with the right hemisphere's more negative affective tone. A theory of right hemisphere involvement in depressive affect is presented in detail and its relevance to clinical phenomena, e.g., the co-occurrence of depression and pain, and sex differences in depression, is examined, as is congruence with cognitive theories of depression.

A logical functional analysis of reinforcement-based disorders: alcoholism and pedophilia.

This article discusses a nomothetic functional strategy, termed logical functional analysis, as an approach to the refinement of the structural diagnostic categories of the Diagnostic and Statistical Manual of Mental Disorders (e.g., 4th ed.; DSM-IV; American Psychiatric Association, 1994). As heterogeneous diagnostic categories are more the norm than the exception in the DSM-IV, an argument is made for the identification of homogenous subgroups within diagnostic classes based on functional principles. Outlines of a logical functional analysis for 2 reinforcement-based disorders, alcoholism and pedophilia, are presented. The outlines show how topographically similar behavior patterns can serve different functions that are important to consider when making treatment decisions. The logical functional analysis is a strategy that helps practitioners to identify motivational conditions, antecedents, consequences, and concomitant behavioral repertoires associated with a given disorder. It also provides guidance for the selection of intervention strategies.

Comparison of reactive and non-reactive measures of smoking cessation at follow-up.

Subjects who had completed a smoking cessation program were contacted at 3- and 4-month follow-up to assess self-reported frequency of daily cigarette smoking. Subjects were randomly assigned to a reactive or non-reactive condition of telephone contact in obtaining the self-report. In the reactive condition, the telephone caller seeking self-report identified herself as an assistant in the original smoking cessation treatment program. In the non-reactive condition the telephone caller identified herself as an employee of a firm conducting a market research survey of the use of various consumer products. There were no statistically significant differences between the conditions in either self-report of abstinence or absolute frequency of daily cigarette consumption.

Compound stimuli in emergent stimulus relations: Extending the scope of stimulus equivalence.

Three experiments were conducted to investigate stimulus relations that might emerge when college students are taught relations between compound sample stimuli and unitary comparison stimuli using match-to-sample procedures. In Experiment 1, subjects were taught nine AB-C stimulus relations, then tested for the emergence of 18 AC-B and BC-A relations. All subjects showed the emergence of all tested relations. Twelve subjects participated in Experiment 2. Six subjects were taught nine AB-C relations and were then tested for symmetrical (C-AB) relations. Six subjects were taught nine AB-C and three C-D relations and were then tested for nine AB-D (transitive) relations. Five of 6 subjects demonstrated the emergence of symmetrical relations, and 6 subjects showed the emergence of transitivity. In Experiment 3, 5 college students were taught nine AB-C and three C-D relations and were then tested for nine equivalence (D-AB) relations and 18 AD-B and BD-A relations. Three subjects demonstrated all tested relations. One subject demonstrated the AD-B and BD-A relations but not the D-AB relations. One subject did not respond systematically during testing. The results of these experiments extend stimulus equivalence research to more complex cases.

Protocol analysis of the correspondence of verbal behavior and equivalence class formation.

In two equivalence experiments, a "think aloud" procedure modeled after Ericsson and Simon's (1980) protocol analysis was implemented to examine subjects' covert verbal responses during matching to sample. The purpose was to identify variables that might explain individual differences in equivalence class formation. The results from Experiment 1 suggested that subjects who formed equivalence classes described the relations among stimuli, whereas those not showing equivalence described sample and comparison stimuli as unitary compounds. Because Experiment 1 only demonstrated a correlation between describing stimulus compounds and the absence of equivalence classes, a second study was conducted. In Experiment 2, equivalence class formation was brought under experimental control through pretraining manipulations that facilitated responding either to stimulus compounds or to relations among stimuli. The results demonstrated that a history of describing stimulus compounds, when compared with describing the relations among the stimuli, interfered with the emergence of stimulus equivalence. These findings clarify individual differences in stimulus equivalence. They also demonstrate the utility of analyzing verbal reports to identify possible variables that can be manipulated experimentally.

A computer touch-screen apparatus for training visual discriminations in rats.

We describe an operant conditioning apparatus that uses computerized touch-screen technology and is designed for the versatile and highly controlled testing of rats in a potentially wide variety of behavioral paradigms. Although computer-controlled touch-screen systems have been developed for use with pigeons, monkeys, and humans, analogous technologies and methods have not yet been developed for rats. The development of a touch-screen system for rats could enhance the efficiency of behavioral research with rats, and may offer a unique tool for studying animal learning. In the first test of the utility of the apparatus, 3 Sprague-Dawley rats learned to activate the touch screen only after the touch-screen panel was made slightly movable. These animals then learned to discriminate visual stimuli presented on the computer monitor, but only after the food magazine and pellet dispenser were moved to the rear of the chamber opposite the stimulus display and response window. In a test of the utility of the modified apparatus, 6 Long-Evans rats learned to activate the touch screen and learned one of three different simple discriminations using computer-generated, visually presented stimuli. A basic method for training rats to activate the computer touch screen and for visual discrimination training is described. Results show that rats learned to activate the touch screen and discriminate visual stimuli presented on a computer monitor. Potential applications and advantages of the touch-screen-equipped rat operant conditioning chamber are discussed.

The transfer of respondent eliciting and extinction functions through stimulus equivalence classes.

Two studies investigated the transfer of respondent elicitation through equivalence classes. In Experiment 1, match-to-sample procedures were used to teach 8 subjects two four-member equivalence classes. One member of one class was then paired with electric shock, and one member of the other class was presented without shock. All remaining stimuli were then presented. Using skin conductance as the measure of conditioning, transfer of conditioning was demonstrated in 6 of the 8 subjects. In Experiment 2, similar procedures were used to replicate the results of Experiment 1 and investigate the transfer of extinction. Following equivalence training and conditioning to all members of one class, one member was then presented in extinction. When the remaining stimuli from this class were then presented, they failed to elicit skin conductance. In the final phase of the experiment, the stimulus that was previously presented in extinction was reconditioned. Test trials with other members of the class revealed that they regained elicitation function. These results demonstrate that both respondent elicitation and extinction can transfer through stimulus classes. The clinical and applied significance of the results is discussed.

A bigger picture: cause and cognition in relation to differing scientific frameworks.

The exchange between Lee (1992) and Hawkins (1992) on the one hand and Bandura (present volume) on the other represents a far more fundamental disagreement than whether behavior-analytic or cognitive accounts of self-efficacy are more persuasive. The deeper disagreement is really a conflict between equally legitimate but incompatible world views and, thus, it is both ontological and epistemological in nature. The present paper argues that the disagreement can be traced to differences between mechanistic and contextual or relational scientific frameworks and involves such issues as basic scientific objectives, units of analysis, and differing perspectives on causation and explanation. These differences are briefly described.

Cognitive concepts, behavior analysis, and behavior therapy.

This symposium acknowledges that the dispute between cognitively oriented and behavior analytically oriented behavior therapists is, in fact, a paradigm clash and that the essential disagreements are "pre-analytic" in nature and are not resolvable by data alone.

The transfer of avoidance evoking functions through stimulus equivalence classes.

Recent research in the area of stimulus equivalence suggests that transfer of function via members of stimulus equivalence classes may have relevance to human emotional responding and the development and generalization of certain psychological disorders. This study investigated the transfer of avoidance evoking functions through equivalence classes. Eight subjects were trained in the necessary relations for two-four member stimulus equivalence classes to emerge. Next, using an on-baseline classical conditioning procedure, one member of one class was paired with shock while one member of the other class was presented without shock. Then, while subjects engaged a key-press task, a differential, signalled avoidance task was introduced wherein shock was avoided if a response occurred to the stimulus previously associated with shock. The remaining stimuli from both classes were then presented. The behavior of all eight subjects showed the differential transfer of the avoidance evoking function. The clinical and theoretical implications of the results are discussed.

The effects of covert sensitization on preference for sexual stimuli: a preliminary analogue experiment.

Although covert sensitization is a widely and diversely employed clinical technique, there is no generally accepted conceptual guideline for its implementation. Consequently, there is considerable variability in the way covert sensitization procedures are employed, which may account for the reported inconsistency in its clinical effectiveness. The present study is an analogue experimental test of a conceptual account of covert sensitization that is based upon classical conditioning. The classical conditioning procedure is viewed as affecting operant target behaviors by altering the reinforcer effectiveness of target stimuli. This was explicitly tested by examining the effects of covert sensitization on subjects' preference for sexual stimuli in an operant choice paradigm. The results support the conceptual account.

Sex differences and personality factors in responsivity to pain.

This study investigated the relationship between measured levels of masculinity-femininity, social desirability, and responsivity to pain in men and women. The literature suggests that the two personality variables might provide an explanation for the common findings of higher pain thresholds and tolerances in men than in women. A significant interaction was found between masculinity-femininity and sex for pain thresholds. Analysis of this interaction indicated that for men, but not women, there was a significant correlation between masculinity-femininity and pain, where higher masculinity was associated with higher pain thresholds. However, this finding did not account for the sex difference in pain threshold. The sex of the subject remained a significant predictor of both pain thresholds and tolerances after allowing for the influence of masculinity-femininity, social desirability, and their associated interactions.

Research: conception to completion.

UNLABELLED: A lack of theory-based nursing research exists in the area of vascular disease. Nursing research is critical to evaluate the effectiveness of specific nursing interventions with the patient population with peripheral vascular disease. This knowledge will strengthen the scientific basis for nursing practice. For the purpose of facilitating increased participation in nursing research by members of the Society for Vascular Nursing, the authors presented the following article, " RESEARCH: Conception to Completion," at the Tenth Annual Symposium in Chicago. The author's current research entitled, "The Effects of Nurse Follow-Up on Increasing Self Care in Patients With Peripheral Vascular Disease: A Prospective Randomized Study," is used as a prototype to illustrate the conceptual, empiric, and interpretive phases of the research process. As the Society for Vascular Nursing moves into its second decade, members will become more focused on research that will generate new knowledge and validate current practices as vascular specialists. There is a great need for the generation and dissemination of knowledge that will help nurses better understand adaptation to health and illness. From this knowledge must come clinical strategies that assist people to promote their own health or cope with illness and its effects on their lives. Vascular specialists must be at the forefront of this effort. Furthermore, the era of cost containment has resulted in increasing pressure to document what nurses do and the differences they make in the outcomes of patient care. The most important outcome of clinical nursing research is the potential benefit it offers to patients. This article will review the steps in conducting nursing research.

A behavior-analytic account of depression and a case report using acceptance-based procedures.

Although roughly 6% of the general population is affected by depression at some time during their lifetime, the disorder has been relatively neglected by behavior analysts. The preponderance of research on the etiology and treatment of depression has been conducted by cognitive behavior theorists and biological psychiatrists and psychopharmacologists interested in the biological substrates of depression. These approaches have certainly been useful, but their reliance on cognitive and biological processes and their lack of attention to environment-behavior relations render them unsatisfactory from a behavior-analytic perspective. The purpose of this paper is to provide a behavior-analytic account of depression and to derive from this account several possible treatment interventions. In addition, case material is presented to illustrate an acceptance-based approach with a depressed client.

Establishing operations, cognition, and emotion.

In this paper we argue that behavior analysts have tended to neglect the study of important aspects of complex human behavior, including cognition and emotion. This relative neglect has been costly in terms of mainstream psychology's perception of the field of behavior analysis and in terms of our ability to provide a more thorough account of human behavior. Observations and findings from the clinical context are offered as examples of behavior that are not readily explained by the three-term contingency, and we argue that an adequate account of these behaviors must include principles derived from recent behavior-analytic work, in particular a better understanding of the short- and long-term effects of establishing operations. The concept of the establishing operation and its implications for understanding complex human behavior are discussed.

The dimensions of clinical behavior analysis.

In most talk therapies for outpatient adults, the therapist has no contro over the client's daily life or contingencies outside the treatment session. The fundamental theoretical issue facing the behavior analyst is, "How can the talking that goes on during the session help the client with problems that occur outside the session in the client's daily life?" An historical analysis and the application of verbal behavior principles are used to answer the question and form the basis of clinical behavior analysis (CBA). The implications of CBA range from providing a theoretical base for psychotherapy to suggesting new forms of treatment.