HER4 expression correlates with cytotoxicity directed by a heregulin-toxin fusion protein

We have constructed, expressed, and purified a fusion protein, HAR-TX beta 2, consisting of heregulin-beta 2 fused to a binding-defective form of Pseudomonas exotoxin A, PE40. The fusion protein was found to induce receptor tyrosine phosphorylation in CEM cells transfected with HER4 alone or in combination with HER2 but not in cells transfected with HER2 or HER1 alone. The phosphorylation of receptor tyrosines was both dose-dependent and saturable in amounts similar to those shown to be active for native heregulin. HAR-TX beta 2 was specifically cytotoxic toward a variety of carcinoma cell lines in the ng/ml range. However, some tumor cell lines were found to be insensitive to the cytotoxic action of the fusion protein even at > 2 micrograms/ml. Relative amounts of HER4, HER3, and HER2 were determined on seven cell lines sensitive and four cell lines insensitive to HAR-TX beta 2. All lines that express HER4 were killed by HAR-TX beta 2, while none lacking HER4 were affected. HAR-TX beta 2 was able to bind to and signal via tyrosine phosphorylation in cell lines that co-express HER2 and HER3 in the absence of HER4 without inducing cytotoxicity. Thus HAR-TX beta 2 may prove to be a useful reagent for the targeting and elimination of HER4-positive tumor cells.

The use of orthodontics before fixed prosthodontics in restorative dentistry

For a variety of reasons, orthodontic intervention is often overlooked as a viable modality to correct occlusal, axial, rotational, and space discrepancies before undertaking fixed prosthetic rehabilitation. However, patient treatment is being enhanced as never before by such intervention. This valuable treatment option facilitates tooth preparation, path of insertion, optimum oral hygiene, and a better pontic and abutment design, while occlusal forces can be directed against the long axes of the teeth for a more predictable prognosis. Moreover, this interdisciplinary approach can be cost-effective to patients and their treating dentists from the standpoint of producing more stable, durable, and esthetic restorations.

Pulp response to a novel adhesive calcium hydroxide based cement

This study compares pulp responses to 3 formulations of calcium hydroxide, namely: a) An experimental adhesive calcium hydroxide cement containing polyacrylic acid, b) Dycal (L.D> Caulk Co, Milford, Delaware) Batch Nos 176970/176990, c) "Analar" calcium hydroxide mixed with sterile distilled water. After 28 days dentine bridges were present in 77% of teeth capped with the test material, 64% of teeth treated with Dycal and in 62% of teeth capped with calcium hydroxide and water. Inflammatory infiltrates were observed in a number of teeth remote from the bridges. Bacteria were detected in these specimens. Exposed rat molar pulp responses to an experimental adhesive calcium hydroxide cement were similar to to those observed with 2 other calcium hydroxide formulations.

Development of two new lining/base materials based upon calcium hydroxide/polyacrylic acid

Two experimental adhesive calcium hydroxide cements containing polyacrylic acid were formulated and tested. These experimental materials were stronger than a proprietary calcium hydroxide formulation and were capable of adhesion to dentine. The properties of these new formulations indicated that preliminary biological testing is warranted.

Development of new adhesive pulp capping materials

The pulp capping materials currently available do not adhere to dentine but cover it and therefore extensive removal of tooth tissue is necessary to expose sufficient dentine for the adhesives used to secure the restoration (the adhesives do not adhere to the capping material). The authors describe how two new pulp capping materials have been developed, which combine the properties required for pulp capping with an ability to adhere to dentine.

The conserved C-terminal domain of the bovine papillomavirus E5 oncoprotein can associate with an alpha-adaptin-like molecule: a possible link between growth factor receptors and viral transformation

The bovine papillomavirus E5 gene encodes an oncoprotein that can independently transform rodent fibroblasts. This small 44-amino-acid protein is thought to function through the activation of growth factor receptors. E5 activation of the epidermal growth factor receptor results in an increase in the number of activated receptors at the cell surface. This finding suggests that E5 may act by inhibiting the normal down regulation of activated epidermal growth factor receptor via coated pit-mediated endocytosis. We have constructed a fusion protein consisting of glutathione S-transferase and the conserved C-terminal domain of E5 (GST-E5) in order to identify E5-associated cellular proteins that may be involved in its transforming activity. We have identified a 125-kDa cellular protein with a strong associated serine kinase activity that specifically associated with GST-E5 in the reduced form but not with GST-E5 fusions that contained changes in several conserved amino acids. Microsequence and biochemical analyses suggest that p125 is a novel member of the alpha-adaptin family. Since alpha-adaptins have previously been shown to be involved in coated pit-mediated cell surface receptor endocytosis and down regulation, these results suggest that p125 may be an alpha-adaptin-like molecule involved in growth factor receptor down regulation and that E5 may act by inhibiting its activity.

Transformation-specific interaction of the bovine papillomavirus E5 oncoprotein with the platelet-derived growth factor receptor transmembrane domain and the epidermal growth factor receptor cytoplasmic domain

The bovine papillomavirus E5 transforming protein appears to activate both the epidermal growth factor receptor (EGF-R) and the platelet-derived growth factor receptor (PDGF-R) by a ligand-independent mechanism. To further investigate the ability of E5 to activate receptors of different classes and to determine whether this stimulation occurs through the extracellular domain required for ligand activation, we constructed chimeric genes encoding PDGF-R and EGF-R by interchanging the extracellular, membrane, and cytoplasmic coding domains. Chimeras were transfected into NIH 3T3 and CHO(LR73) cells. All chimeras expressed stable protein which, upon addition of the appropriate ligand, could be activated as assayed by tyrosine autophosphorylation and biological transformation. Cotransfection of E5 with the wild-type and chimeric receptors resulted in the ligand-independent activation of receptors, provided that a receptor contained either the transmembrane domain of the PDGF-R or the cytoplasmic domain of the EGF-R. Chimeric receptors that contained both of these domains exhibited the highest level of E5-induced biochemical and biological stimulation. These results imply that E5 activates the PDGF-R and EGR-R by two distinct mechanisms, neither of which specifically involves the extracellular domain of the receptor. Consistent with the biochemical and biological activation data, coimmunoprecipitation studies demonstrated that E5 formed a complex with any chimera that contained a PDGF-R transmembrane domain or an EGF-R cytoplasmic domain, with those chimeras containing both domains demonstrating the greatest efficiency of complex formation. These results suggest that although different domains of the PDGF-R and EGF-R are required for E5 activation, both receptors are activated directly by formation of an E5-containing complex.

Perception of self and other in major depression

Previous research on the nature of person perception in depression has been inconclusive. This investigation differs from earlier studies in that extensive free-response descriptions of other people and self were collected from patients with major depression and from nonpsychiatric control Ss. In comparison with control Ss, depressed patients described fewer positive aspects not only of self but also of parents and significant others and reported more negative aspects of these people. Cluster analysis (HICLAS) also showed that more cognitive differentiation of negative self-perceptions (negative self-complexity) was characteristic of clinical depression. In both control Ss and patients, a positive (or negative) view of self was highly correlated (.85 or more) with a positive (or negative) view of parents and significant others. These correlations were significantly stronger than those between self and less important others.

Effect of thermal placement techniques on some physical properties of gutta-percha

Some clinical techniques for the placement of gutta-percha root fillings involve the application of heat. This study was undertaken to assess the effects of intracanal heating techniques on the following properties of gutta-percha: coefficient of thermal expansion, softening temperature, phase transition temperature and organic content. Samples from each of four products were prepared by three different methods. The materials were studied by thermomechanical analysis, simultaneous thermogravimetry and differential thermal analysis, and by measurement of weight loss on ashing. It was shown that the techniques of gutta-percha placement involving heating in the root canal caused reversible physical changes in the materials without any apparent change in chemical composition. The average coefficient of thermal expansion was 137 x 10(-6)/degrees C, the softening temperature was 55.5 degrees C, there were two characteristic phase changes, and the organic content was 25%.

Orthodontic adjunctive treatment in fixed prosthodontics

The purpose of this article has been to increase the restorative dentist's appreciation for the rationale justifying preprosthodontic orthodontic treatment. It has not been intended to identify all the specific indications for the use of orthodontic treatment to enhance prosthodontic treatment nor has it been intended as a reference to assist the restorative dentist in placing and using orthodontic appliances. Figure 12 illustrates a typical case in which the combination of orthodontic and prosthodontic treatment resulted in a more favorable outcome than prosthodontic treatment alone. When planning prosthodontic treatment, the dentist should embrace a dynamic view of tooth position and determine whether restorative treatment can be enhanced by tooth movement. Improved tooth position can eliminate potentially pathologic occlusion and create a healthier periodontal environment that is easier to maintain. In addition, it permits the dentist to place restorations that often require less natural tooth reduction during preparation, and that are more esthetic, functional, stable, and durable. Orthodontic treatment that accomplishes these benefits may be limited to a partial fixed appliance localized to one segment of an arch or require a more extensive fixed appliance. Much of this treatment can be accomplished by the interested restorative dentist. Addressing more comprehensive orthodontic problems in patients requiring prosthodontic care is best managed through a restorative dentist and orthodontist team approach to treatment.

Identification and characterization of the neurofibromatosis type 1 protein product

The neurofibromatosis type 1 (NF1) gene responsible for von Recklinghausen neurofibromatosis is related to regulators of ras proteins, and a portion of NF1 that is homologous to the ras GTPase-activating protein (GAP) encodes a similar GTPase-stimulating activity. We have raised rabbit antisera to a bacterially synthesized 48-kDa peptide corresponding to the GAP-related domain of NF1 (NF1-GRD). These antisera immunoprecipitated the NF1-GRD peptide, and one of them specifically inhibited the GTPase-stimulating activity of NF1-GRD. The sera specifically detected a 280-kDa protein in lysates of mouse NIH 3T3 and human HeLa cells. This protein corresponds to the NF1 gene product, as shown by several criteria, including partial proteolysis. Subcellular fractionation revealed that while GAP is predominantly cytoplasmic, all of the NF1 was recovered in a pellet (100,000 x g) fraction. NF1 was present in a large molecular mass complex in fibroblast and Schwannoma cell lines and appears to associate with a very large (400-500 kDa) protein in both cell types. The relevance of these findings to cellular regulation of p21ras is discussed.

Castable glass ceramic crowns and their reaction to endodontic therapy

The purpose of this investigation was to determine how castable glass (Dicor) crowns would react to both cold testing and endodontic access intervention. Full crown preparations were made on six extracted maxillary teeth. The teeth were then forwarded to Dentsply International, York, Pa. Six castable glass crowns were fabricated to fit these teeth and returned to us. Subsequently the teeth were dried and the crowns were cemented. Scanning electron micrographs of the cemented crowns were made, and endodontic access openings were drilled. The teeth were also cold tested with standard methods. The teeth were then again subjected to scanning electron microscopy to determine any changes the crowns might have undergone. One crown cracked around the gingival collar as scanning electron microscopy was performed. The other crowns did not exhibit any problems such as cracking or crazing from either the access openings or the cold testing.

Self-structure in schizophrenia

This study used a set-theoretical model to construct self-perception structures and person-perception structures for 10 recently hospitalized schizophrenic patients, 10 nonschizophrenic patients recently hospitalized for depression, and 10 nonpsychiatric subjects. Overall self-perception structures were significantly less elaborated in the schizophrenic patients when compared with either the psychiatric or the nonpsychiatric comparison group. No comparable differences were found for measures taken from the person-perception structures. The degree of elaboration of self in the particular context of self as psychiatric patient was found to be correlated (r = .74, p less than .01) with Global Assessment Scale ratings of current functional level in the schizophrenic group.

Self-structure in schizophrenia

This study used a set-theoretical model to construct self-perception structures and person-perception structures for 10 recently hospitalized schizophrenic patients, 10 nonschizophrenic patients recently hospitalized for depression, and 10 nonpsychiatric subjects. Overall self-perception structures were significantly less elaborated in the schizophrenic patients when compared with either the psychiatric or the nonpsychiatric comparison group. No comparable differences were found for measures taken from the person-perception structures. The degree of elaboration of self in the particular context of self as psychiatric patient was found to be correlated (r = .74, p less than .01) with Global Assessment Scale ratings of current functional level in the schizophrenic group.

The horizontal-vertical illusion and knowledge of results

The Horizontal-Vertical (HV) Illusion was examined in two studies in which subjects adjusted the vertical line in L-shaped and inverted-T figures or produced lines in the vertical and horizontal planes. On the adjustment tasks, vertical lines were made significantly shorter than horizontal comparison lines, especially for the inverted-T figure. On the production tasks, lines drawn in the vertical plane were significantly shorter than lines drawn in the horizontal plane. The adjusted and created lines of subjects receiving intertrial feedback on illusion magnitude were significantly more accurate and less variable than the estimations of control subjects. Performance on either task or figure type did not differ as a function of sex of subject. The present results show that the HV illusion exists in the absence of line bisection or a comparison line and results from the overestimation of vertical lines. These findings further clarify the relative contributions of the structural and strategy mechanisms in the formation of the Horizontal-Vertical Illusion.

Personal identity and the schizophrenic process: an integration

In this paper we explore the relation between theories of self, particularly identity theory, and the schizophrenic process. A fundamental assumption in identity theory is that a person's self includes a hierarchically organized set of identities. When an individual's set of identities is limited in range and/or diffusely organized he/she is thought to be at risk for schizophrenia. The onset and relapse of schizophrenic episodes are assumed to occur when important identities are negated. Implications of identity theory for integrating extant conceptions of schizophrenia are discussed. Also discussed are the effects of medication in establishing a patient identity and the role of the patient identity in preventing psychotic relapse.

Hepatitis A virus in stool during clinical relapse

Among 256 patients with acute hepatitis A, 17 (6.6%) had a relapse of the disease between 30 and 90 days after the primary episode. We studied 7 of these patients. Serologic testing showed mean alanine aminotransferase levels of 1668 IU/L during the acute stage, 107 IU/L during the early convalescence, and 1027 IU/L during the relapse. Tests for IgM antibody against hepatitis A virus were positive in the 7 patients at the onset of disease, with decreasing levels in 3 of the 4 patients tested during the evolution of the illness. Stools collected during the relapse phase showed hepatitis A virus by immune electron microscopy, radioimmunoassay, and molecular hybridization using a 32P-labeled cDNA-hepatitis A virus probe. Stools collected from 4 of these patients 6 to 12 months after the onset of disease were negative for the virus. The finding of hepatitis A virus in the stool of these patients during the relapse phase strongly implicates hepatitis A virus as the causative agent of the clinical relapse.