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J C de Sousa

Publications and source records attributed to J C de Sousa.

10 recordsLinked to original sources
PubMed1997

[Antithrombotic therapy in the elderly patient].

In 1994 there were about 100,000 deaths in Portugal (99.621), most of these (43%) were caused by cardiocirculatory and cerebrovascular diseases. A revision about antithrombotic therapy in the elderly is completely justified by the importance of these numbers. In respect to oral anticoagulant therapy, special attention is given to its use in atrial fibrillation concerning the actual therapeutic levels. The current recommendations point to the use of INR levels inferior to those usually used. An INR superior to 2.0-3.0 is only used in the case of valvular mechanical prosthesis. Particular importance is given to the problem of therapeutic induction, mentioning the principal causes of fluctuation of dose/response to oral anticoagulants in the elderly, with special attention to the possible alterations of vitamin K metabolism and the therapeutic interference. Finally, we specify the hemorrhagic complications of this kind of antithrombotic treatment, and give the recommended measures for a practical action for patients with a high level of INR with or without hemorrhages. Concerning heparin therapy, an explanation of the action of heparin and the principal differences between standard heparin and low molecular weight heparins are presented. In the elderly, we point out the secondary effects, such as hemorrhages, thrombocytopenia induced by heparin and osteoporosis. The usual measures for its minimization are related to the recommended dose and type of heparin administered. Finally, we approach the problem of the antiplatelet therapy. The current knowledge is reviewed concerning its use in primary prevention and the minimum dose of aspirin that seems to be effective. The use of aspirin in primary prevention, even if it is not well specified, can be proposed, in a minimum dose, in the elderly with high vascular risk (among other associated factors). However, some particular cases must be studied because an identical clinical attitude cannot be accepted for all patients. The minimum effective dose of aspirin is now also known to be significantly inferior to the one that has been used. With the possible exceptions of atrial fibrillation and valvular prosthesis, aspirin seems to be effective in doses of approximately 75 to 150 mg/day. Other possibilities of antiplatelet therapy, are also analysed, with emphasis on platelet receptor inhibitors and metabolic inhibitors, even if their indications not yet been have completely established.

Administration, Oral↗
PubMed1996

[Platelet antigens: immunology and immuno-allergology].

Platelet immunology allows the understanding of clinical findings in a genetic and serologic basis. Blood platelets bear common antigens and same specific antigens, classified in five groups (HPA 1 to 5), that are localized on membrane glycoproteins Ia, Ib alpha, IIb and IIIa. Antiplatelet autoimmunization is generally due to IgG antibodies against membrane complexes IIb/IIIa or Ib/lX. Antiplatelet alloimmunization, clinically resulting in Posttransfusion Purpura and Neonatal Thrombocytopenia is more frequently associated with anti-IIb/IIIa antibodies, either anti-HPA-1a or HPA-1b. Finally, platelet participation in immunoallergic reactions is discussed, focusing both platelet activation by allergen itself and platelet recruitment by other inflammatory cells.

Adult↗
PubMed1995

The distribution of endocrine cell types of the gastrointestinal mucosa in genetically diabetic (db/db) mice.

BACKGROUND/AIMS: Genetically diabetic (db/db) mice are a model for non-insulin-dependent diabetes in humans. The gastrointestinal tracts in 12-week-old db/db and nondiabetic control (db/+) mice were studied with particular emphasis on the endocrine cells. METHODS: Immunocytochemical and quantification techniques were used to localize and determine the number of cells containing serotonin and various regulatory peptides. RESULTS: In the antrum, the gastrin- and serotonin-immunoreactive cells were increased in number. In the large intestine, the enteroglucagon and the peptide tyrosine-immunoreactive cells were increased in number, whereas there were fewer serotonin-immunoreactive cells. There were also fewer somatostatin-immunoreactive cells in most gastrointestinal regions. In diabetic mice, the intestine was longer and its mucosa thicker than in control mice. CONCLUSIONS: The results indicate that the genetic diabetic (db/db) condition exerts a significant influence on the gastrointestinal tract and on the endocrine cell systems studied. The observed alterations may reflect the effect of indirect factors rather than the diabetes per se.

Animals↗
PubMed1994

[Antiphospholipid immunization syndrome and thrombosis].

The designation of Antiphospholipid Syndrome was first applied by Harris in 1987, to a clinical status characterized by the detection of anticardiolipin and/or lupus anticoagulant with clinical thromboembolic manifestations. Recent advances in its study has shown that the inducing antigen is really a complex of phospholipid and protein. Therefore, it became clear that there is a need for a protein cofactor to the formation and action of antiphospholipid antibodies (APL). The authors present a detailed revision of the nature and specificity of APL, described as its proteic counterpart. Their action is surely conditioned by the specific protein involved with phospholipids, as it may be with Beta 2-Glycoprotein 1, Prothrombin, Protein c and s, Anexin V and the association of plasminogen and t-PA. The isotype of immunoglobulins is also very heterogeneous, since it was detected as IgG as well as IgA and IgM immunoglobulins. Furthermore, they can coexist in the same patient and with no clear relationship with thromboembolic manifestations. These aspects demonstrate well the greater variability that is found in these patients in relation to clinical and laboratory manifestations of the disease. For laboratory diagnosis, micro ELISA systems were developed, allowing the identification of antiphospholipid immunoglobulins with relative specificity and accuracy. Finally, the most frequent clinical expression is described, emphasising the pitfalls of clinical and laboratory diagnosis of the antiphospholipid syndrome.

Antiphospholipid Syndrome↗
PubMed1991

[Antithrombin III. Physiologic, physiopathologic and laboratory aspects].

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.

Antithrombin III↗
PubMed1988

Association between coagulation factors VII and X with triglyceride rich lipoproteins.

The association between the concentration of different plasma lipoproteins and plasma factor VII (F VII) was analysed by isolating plasma very low density lipoprotein (VLDL), low density lipoprotein (LDL), and high density lipoprotein (HDL) lipoproteins and assessing their in vitro interaction with F VII by immunoenzyme assay using peroxidase labelled anti-factor VII immunoglobulins to determine whether F VII coagulant activity is prognostic for cardiovascular mortality. F VII bound to triglyceride rich lipoproteins, the fixation being stronger on chylomicrons and VLDL fractions than on LDL fractions. In our experiments HDL did not bind to F VII. The fixation of coagulation factor X (FX) tested by the same method is comparable with that of F VII. The nature of this fixation seemed to arise from hydrophobic interaction as calcium was not necessary and the use of Tween 20 inhibited the interaction. The binding of factors VII and X was increased when lipids were previously treated by phospholipase C and the interaction seemed to be completely dependent on the lipid part of the lipoproteins. Hyrophobic fixation is a possible mechanism of interaction of plasma lipoproteins and F VII and X, and it may be of importance in the covariance of triglyceride concentrations and the activity of vitamin K dependent coagulation factors.

Adult↗
PubMedDate not supplied

[Complementary internship of clinical pathology in hematology].

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)

Curriculum↗