Purification of biosynthetic threonine deaminase from Escherichia coli.

Biosynthetic threonine deaminase (L-threonine hydro-lyase (deaminating), EC 4.2.1.16) was purified to apparent homogeneity from cell extracts of Escherichia coli by chromatographic procedures using valine-Sepharose, isoleucine-N-hexamethyleneamine-Sepharose, and hydroxyapatite with an overall yield of 40%. Analytical ultracentrifugation shows a molecular weight of 214 000. In sodium dodecyl sulfate gel electrophoresis, the enzyme migrates as a single band corresponding to a molecular weight of about 50 000. These data confirm that the enzyme is a tetramer. The sedimentation coefficient, s-020,w, determined by differential sedimentation experiments is 9.2 S. The enzyme shows absorption maxima at 415 and 280 nm. Determination of pyridoxal phosphate by three indenpendent methods shows the presence of two molecules of pyridoxal phosphate per enzyme molecule, the different methods being in excellent agreement equilibrium dialysis experiments establish the presence of two isoleucine binding sites. The Scatchard plot suggests non-cooperativity of these sites. The association constant for isoleucine is 1.2 - 10(5)M-1.

Diagnosis of personality disorder: a radical behavioral alternative.

From a radical behavioral perspective, a single, diagnostic system is unlikely to serve diverse purposes. Instead, ideal diagnostic systems should be developed to serve specific purposes. For example, the crucial proof required of a classification system designed to improve the outcome of psychosocial intervention would be that it enhance the clinician's influence on processes associated with client change. This means, in turn, that the change processes must be known or theoretically specified. As an illustration of this general approach to diagnostic classification, a specific behavioral theory is used to articulate processes of change in psychotherapy. The Axis II of the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) is then evaluated with respect to its ability to enhance clinicians' influence of these processes, found problematic, and an alternative classification criterion is proposed.

Testing the integrity of a psychotherapy protocol: assessment of adherence and competence.

Manipulation checks should be used in psychotherapy trials to confirm that therapists followed the treatment manuals and performed the therapy competently. This article is a review of some strategies that have been used to document treatment integrity; also, their limitations are discussed here. Recommendations for improving these checks are presented. Specific guidelines are offered regarding when and how to assess both therapist adherence to treatment protocols and competence.

A component analysis of cognitive-behavioral treatment for depression.

The purpose of this study was to provide an experimental test of the theory of change put forth by A. T. Beck, A. J. Rush, B. F. Shaw, and G. Emery (1979) to explain the efficacy of cognitive-behavioral therapy (CT) for depression. The comparison involved randomly assigning 150 outpatients with major depression to a treatment focused exclusively on the behavioral activation (BA) component of CT, a treatment that included both BA and the teaching of skills to modify automatic thoughts (AT), but excluding the components of CT focused on core schema, or the full CT treatment. Four experienced cognitive therapists conducted all treatments. Despite excellent adherence to treatment protocols by the therapists, a clear bias favoring CT, and the competent performance of CT, there was no evidence that the complete treatment produced better outcomes, at either the termination of acute treatment or the 6-month follow-up, than either component treatment. Furthermore, both BA and AT treatments were just as effective as CT at altering negative thinking as well as dysfunctional attributional styles. Finally, attributional style was highly predictive of both short- and long-term outcomes in the BA condition, but not in the CT condition.

Research on dialectical behavior therapy for patients with borderline personality disorder.

Research evidence to date indicates that, although DBT was developed for the treatment of patients with suicidal behavior, it can be adapted to treat BPD patients with comorbid substance-abuse disorder and be extended to other patient populations and the treatment of other disorders. Across studies, DBT seems to reduce severe dysfunctional behaviors that are targeted for intervention (e.g., parasuicide, substance abuse, and binge eating), enhance treatment retention, and reduce psychiatric hospitalization. Evidence suggests that additional research is warranted to examine which components of DBT contribute to outcomes. Although preliminary, skills coaching seems to be a crucial ingredient in producing reductions in parasuicidal behavior, and specific strategies (e.g., validation, balance of change, and acceptance interventions) may play an important role in positive behavioral change. Several investigators are evaluating the efficacy of DBT. For example, Asberg et al at the Karolinska Institute in Sweden have begun a pilot study comparing DBT for women who have made multiple suicide attempts to transference focus psychotherapy, a psychodynamic therapy developed by Kernberg. They have planned a randomized clinical trial to compare DBT and transference focus psychotherapy with TAU in the community. van den Bosch has completed a randomized clinical trial for women who met criteria for BPD and substance abuse comparing DBT-S with TAU. Lynch is conducting a randomized clinical trial examining the efficacy of DBT skills training plus medication versus medication only for the treatment of moderate to severe depression in the elderly. Results from these studies should become available over the next several years, providing further empiric evidence by which to evaluate the efficacy of DBT. Additional development of DBT seems warranted to improve its efficacy, and additional investigation is needed to establish its effectiveness in public health settings. Analyses from existing data sets of factors that predict treatment response and elements of the treatment that contribute to outcome are needed. Also, longitudinal follow-up studies to determine suicide rates and maintenance of treatment gains are needed. Because DBT has been adopted in a variety of clinical settings, effectiveness studies are needed. Given the difficulty of conducting treatment research with chronically suicidal individuals, perhaps the largest challenge to further treatment development is recruiting young investigators who are willing to conduct research in this area. Nevertheless, in the 6 years since the treatment manuals were published, DBT seems to be a step toward more effective treatment for severely multidisordered patients.

Isolation and epitope characterization of human monoclonal antibodies to hepatitis C virus core antigen.

In this study we describe the establishment of two hybridoma cell lines secreting human monoclonal antibodies to the 22-kD nucleocapsid protein (core, p22) of the hepatitis C virus (HCV). For this purpose we isolated B lymphocytes from an anti-HCV positive blood donor and infected them with Epstein-Barr (EBV). We obtained several lymphoblastoid cell clones secreting antibodies to the recombinant HCV core protein. The B-cell cultures were oligoclonally expanded and two of them were fused with the (mouse:human) heteromyeloma cell line K6H6/B5. The resulting stable hybridomas produce antibodies of the IgG1/kappa (U1/F10) and the IgM/kappa (Ul/F11) isotype reacting specifically with the recombinant core protein p22. To identify the epitopes recognized by these antibodies we synthesized overlapping peptides (13-mer and 6-mer) from the amino terminus of the core amino acid sequence. Antibody reactivity to these peptides was analyzed in an immunoblot assay. Finally, we were able to define a linear epitope recognized by the Ul/F10 antibody on the nucleocapsid protein. The antibody shows specificity to the sequence N-VYLLPR-C, which corresponds to the amino acids 34-39 of the core sequence.

The removal of impacted third molars. Principles and procedures.

This article reviews factors relating to the removal of impacted third molars. It covers indications for surgery and how indications and surgical difficulty correspond with the age of the patient. The difficulty of the procedure depends not only on age, but on how the tooth is categorized radiographically (classification, position, angulation) and on the patient's facial characteristics (tapering versus compact facial form). The operator's familiarity with the anatomy of the surgical site is indispensable for uneventful third molar surgery. A signed consent form is necessary to meet medico-legal standards. With a diagnosis, treatment plan, and consent to proceed, these teeth are extricated from their sockets with a modicum of instruments, each one fulfilling a specific purpose. The surgical procedure, whether maxillary or mandibular, can be broken into separate segments for technique elaboration and refinement. These segments are flap development, bone removal, luxation, sectioning, tooth removal, and closure. Specific methods may vary among dental surgeons based on training and experience, but they all should correspond to basic and established principles of surgical technique. Some of these principles and techniques have been outlined in describing the removal of typical mandibular and maxillary third molar impactions.

Pharmacologic considerations in the management of oral surgery patients in general dental practice.

Minor oral surgery is an integral part of dentistry, whether performed by the generalist or the specialist. Procedures include those within the broad discipline of general oral surgery (such as routine and surgical extractions, impactions, preprosthetics, biopsy, and implants), periodontics (such as periodontal surgery, mucogingival plastic surgery, and implants), and endodontics (periapical surgery). There is considerable overlap among generalists and surgical specialists in terms of the treatment provider. Perhaps the most important consideration with regard to appropriateness and quality of care is not who does the surgery but how it is done. The ability to perform surgery according to sound surgical principles and to properly prescribe medications in association with that surgery is a necessary requisite for quality treatment. This article reviewed how various pharmacologic agents can be administered and how they influence surgical procedures. Whether or not they are used and the manner in which they are used are predicated on the discretion and clinical judgment of the clinician on a case-by-case basis. If used appropriately, these medications can be instrumental in mitigating morbidity and increasing tolerance and overall patient satisfaction with the surgical experience.

[Effect of rejuvenation on the rheologic properties of stored erythrocytes]. / Einfluss der Rejuvenation auf die rheologischen Eigenschaften gelagerter Erythrozyten.

Buffycoat free red cell concentrates in a medium composed of sodium chloride, adenine, glucose and mannitol (SAGM) stored for 42 days at +4 degrees C were rejuvenated by a solution which contained pyruvate, inosine, disodiumphosphate and adenine (PIPA). The rheological behaviour of red cells was measured before and after rejuvenation by viscosimetry of red cell suspensions (hematocrit 45%) at various intervals during the storage period. The deformability of the red cells during storage was determined also before and after rejuvenation by measurement of the viscosity of hard packed cells (hematocrit 98%). The results show improvement of the rheological properties by rejuvenation. Moreover it is shown that incubation of the red cells at 37 degrees C for two hours without rejuvenation solution decreases the viscosity.

[Comparative studies of rheologic properties of erythrocyte concentrates in relation to a 6-week storage period in various preservative solutions]. / Vergleichende Untersuchungen der rheologischen Eigenschaften von Erythrozyten-konzentraten während einer Lagerungszeit von sechs Wochen in verschiedenen Konservierungs-lösungen.

Buffycoat free red cell concentrates were stored at 4 degrees C for 42 days in CPD-A1 and two new red cell preservation solutions, PAGGS-Sorbitol and SAG-Mannitol. The rheological behaviour of the red cells was measured by viscometry of red cell suspensions (hematocrit 45%) at steady flow at various intervals during the storage period. The viscoelastic properties of the red cells were studied at oscillatory flow using an oscillation rheometer. The deformability of the red cells during storage was determined by measurement of the viscosity of hard packed cells at steady flow. The results show better red cell deformability during the entire storage period using the new solutions PAGGS-Sorbitol or SAG-Mannitol compared to the standard blood bank preservation solution CPD-A1.

Persuasion criteria in research and practice: Gathering more meaningful psychotherapy data.

Psychotherapy research should ultimately benefit the psychotherapy client. Unfortunately, traditional psychotherapy research continues to have little influence on practicing clinicians and, therefore, does not benefit psychotherapy clients. As behavior analysts begin to show interest in this area of research, they may be in a position to improve its quality. We argue that traditional psychotherapy researchers have become prematurely wedded to a methodology that does not address the concerns of clinical audiences. Furthermore, we make a case for defining and evaluating psychotherapy data in terms of its capacity to influence both researchers and clinicians. We also suggest several alternative methods for gathering psychotherapy data based on the case formulation approach. We argue that this approach may be one of the most promising methods for gathering useful psychotherapy data.

Anterior apicos in general practice: step-by-step guidelines.

Apicoectomy and retroseal procedures should continue to be a mainstay of dental treatment because not all root canal therapy is successful, even when it is amenable to retreatment. Currently accepted methods for performing this operation have been reviewed. With appropriate case selection and the careful implementation of these techniques, the general dentist can confidently provide this service to patients.

Predictable exodontia in general practice.

Exodontia that is carefully and skillfully done by general dentists is a valuable service to patients. The majority of patients would rather have their family dentist perform necessary extractions or other minor surgery procedures than be referred outside the office. Most teeth that need to be extracted could be removed by a generalist if that person has developed the expertise to do not only relatively easy extractions, but also that percentage that is inevitably more difficult--requiring "surgical" removal. To be successful with exodontia, the dentist must have the ability to select cases within his or her level of comfort and ability, have a working knowledge of sound surgical principles, be able to apply a variety of patient management techniques, and then be prepared to handle whatever complications may arise. This article has presented ideas that should be integrated into the operator's own systematic approach to extractions. It is one of many resources to help the general dentist provide a higher level of surgical treatment.