Histological response to titanium endodontic endosseous implants in dogs.

Endodontic endosseous implants stabilize teeth that have crown-root ratios compromised by periodontal disease, trauma, or apical resorption. By increasing the crown-root ratio, the implant improves the prognosis of the tooth, thus increasing its longevity. The purpose of this study was to evaluate, in vivo, the healing response to a newly introduced titanium endodontic implant. Eight implants were placed in the maxillary incisors and mandibular premolars of two adult beagle dogs after completion of root canal and osseous preparation. Peri-implant tissues were examined radiographically and histologically at 6 months postinsertion. Radiographically, the periapical area and tissue surrounding the implants seemed normal. Histologically, fibrous connective tissue and healthy bone intimately surrounded the implant. Epithelium or chronic inflammatory cells were not observed along the length of the implant. These findings suggest that titanium is a biocompatible metal when used as an endodontic endosseous implant.

Cast prosthesis removal using ultrasonics and a thermoplastic resin adhesive.

Nonsurgical endodontic procedures are routinely performed on teeth with existing cast restorations. The internal anatomy of the tooth and location of the root canals may be obscured by a crown or fixed partial denture. Tooth morphology and canal location may, therefore, be better visualized without the cast restoration in place. This article describes a conservative technique to remove an existing cast restoration to facilitate nonsurgical root canal treatment.

[Antithrombin III. Physiologic, physiopathologic and laboratory aspects]. / Antitrombina III. Aspectos fisiológicos, fisiopatológicos e laboratoriais.

Hemostatic control is based in a delicate balance between the activities of activator enzymes and their inhibitors, each one depending on a large number of proteins. Plasma Antithrombin III (ATIII) is one of the most important coagulation inhibitors and the fundamental enzyme for the therapeutical action of heparin. In the last years it was well established that ATIII deficiency accounts for a thrombotic state and inefficiency of heparin therapy. In this work, the authors review the biology of ATIII including its biochemical nature, its physiology, physiopathology and mechanism of action, analysing the implications of its deficiency. The authors draw the attention on clinical and laboratory studies that analyse the prevalence and importance of congenital and acquired deficiency of ATIII, in relation to the prevalence of venous thrombosis. Finally, the laboratory methods applied to the study of ATIII and to the biological control of heparin therapy are described with emphasis on the importance of the ATIII concentrates on this type of treatment. Also the fundamental aspects of heparin resistance are specially mentioned.

[Complementary internship of clinical pathology in hematology]. / Internato complementar de patologia clínica em hematologia.

The correct practice of specialized Clinical Pathology is dependent on the acquired aptitude and capacity gained by residents during their specialization. So, the adopted program for residents must be practical and detailed, obviously exceeding the simple and routine execution of laboratory methods and techniques. In this paper the authors describe a scheme for the Clinical Pathology residents practical program in hematology. The program is applied to a central laboratory (Hospital de Santa Maria - Lisboa). This scheme describes the basic principles for orientation of residents: systematic learning and training of laboratory technology, acquisition of experience in organization and valorizing this activity, introduction to methods and practice of quality control and administration of laboratory activity. Methodological studies and valorization are adapted to its clinical and technical specifications. Furthermore, specialization must include other theoretical and practical activities, which are in fact essential to systematization, organization and consolidation or residents knowledge. We schematized the discussion of technical reports, conception and discussion of investigation protocols and active participation in scientific meetings in this field. Responsibility for the execution of practical scientific work and for the presentation of the final report are fundamental to assess the experience and knowledge that has been acquired and simultaneously to give a mean of self criticism and perfectionism. In fact, this last aspect must be a part of the discussion and conclusion of the final report. In this paper, all these particularities are presented and the methods for their effective use are suggested in detail.(ABSTRACT TRUNCATED AT 250 WORDS)

Factor VII hyperactivity in acute myocardial thrombosis. A relation to the coagulation activation.

It has been shown that coagulation factor VII (FVII) has an increased coagulant activity (FVIIc) in cardiovascular high risk patients and that it is a important risk factor for the development of ischaemic heart disease (IHD) and cardiovascular death. In this study, we measured FVII coagulant (FVIIc) and immunological (FVIIag) activities during the acute phase of unstable angina (UA) and acute uncomplicated and complicated myocardial infarction (AMI). We have also studied its changes in relation to thrombin formation and coagulation activation, as assessed by determination of thrombin-antithrombin circulating complexes (T-AT) at the same time. Our results show a marked increase in FVIIc in all patients, with highest significant levels in complicated AMI. In fact, this increase was also different between groups, complicated AMI showing a significant degree of increase in FVIIc in relation to UA and uncomplicated AMI. FVIIag did not vary between groups and controls, implicating a progressive activation of FVII. As expected, we found comparable levels of T-AT in UA and in AMI patients, suggesting that a common thrombotic process is involved in both situations. FVIIc was strongly correlated to T-AT in all patients (r = 0. 750; p less than 0.001) and also within groups. This study underlines the important positive contribution of FVIIc to IHD and to the prognosis of its thrombotic acute events, and shows that the increase in FVII activity is associated with an increase of a thrombotic marker (thrombin-antithrombin). Further studies are needed to evaluate if FVII activation is the cause or the consequence of the thrombotic processes.