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Biomedical subjects

C Gamallo

Publications and source records attributed to C Gamallo.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Bioprosthetic mitral valve thrombosis: clinical profile, transesophageal echocardiographic features, and follow-up after anticoagulant therapy.

Cardiac bioprosthetic valve thrombosis is frequently found on pathologic examination, but preoperative diagnosis is rarely performed. Four hundred six patients with mitral porcine xenograft bioprostheses were examined by transthoracic echocardiography. Transesophageal echocardiography (TEE) was performed in 161 of the patients, with clinical or echocardiographic criteria of prosthetic malfunction. Fairly homogeneous and echodense masses, attached to the ventricular surface of the mitral bioprosthetic cusps, were detected by TEE in 15 patients. Only 10 patients, in whom diagnosis of bioprosthetic thrombosis was confirmed, are included in this study. After TEE, two patients underwent prosthetic replacement and eight patients received anticoagulants. A new TEE was performed 85.6 +/- 29.8 days after anticoagulation in these eight patients. Clinical follow-up was continued for 13.6 +/- 8.6 months, and one additional patient underwent surgery during the follow-up. Pathologic examination of removed grafts (three cases) identified these masses as being thrombotic tissue. TEE examination after therapeutic anticoagulation demonstrated complete disappearance of the echogenic masses on bioprosthetic cusps and normal mobility of all leaflets in six cases. In the other two cases, cusp masses were notably reduced, but partially restrictive mobility of affected leaflets persisted, suggesting incomplete resolution of thrombi. Mitral valve prosthetic mean gradient decreased from 11.8 +/- 4.5 to 7.6 +/- 3.7 mm Hg (p < 0.001), and mitral valve area increased from 1.13 +/- 0.3 to 1.72 +/- 0.6 cm2 (p < 0.001). Long-term symptomatic improvement after anticoagulation was obtained in seven patients. Thus this study shows that mitral bioprosthetic thrombosis is a relatively frequent cause of valve dysfunction, TEE is useful for detecting thrombus in relation to mitral bioprosthetic valves, and oral anticoagulation is effective in resolving thrombosis on bioprostheses.

Aged↗
PubMedDate not supplied

Cytologic features of malignant peripheral nerve sheath tumor.

OBJECTIVE: To study the cytomorphologic features of malignant peripheral nerve sheath tumor (MPNST), including the epithelioid cell variant, and to establish differential diagnostic features with benign neurogenic tumors and other sarcomas. STUDY DESIGN: Cytologic smears from primary, recurrent and metastatic tumors in 10 patients with MPNST were reviewed. Three patients had neurofibromatosis 1 (NF1), and in two others the tumor arose from a preexisting neurofibroma. Immunocytochemical evaluation of S-100 protein was performed in four cases. A complete pathologic study was available in all cases. To assess the validity of morphologic recognition, a blinded study, including eight cases of spindle MPNST among smears from histologically proven schwannomas, synovial sarcomas, leiomyosarcomas, malignant fibrous histiocytomas and liposarcomas, was performed. RESULTS: Neurogenic differentiation was recognizable in four cases (differentiated), while the other four (anaplastic) were indistinguishable from other pleomorphic sarcomas. The presence of elongated, slender, often wavy nuclei and less commonly a delicate, fibrillary metachromatic stroma were features suggestive of nerve sheath differentiation. Other cytologic, as well as clinical, features permitted their identification as malignant. Two cases of epithelioid MPNST disclosed large, polygonal to plasmocytoid tumor cells without specific cytologic features. S-100 immunoexpression was positive in two of the four cytologic samples tested. CONCLUSION: Although no morphologic findings are specific to MPNST, the above-mentioned cytologic features may suggest, in differentiated cases, its neurogenic differentiation. On the basis of morphologic features alone, the diagnosis of anaplastic and epithelioid MPNST is not possible, and immunocytochemical and ultrastructural studies are necessary. A specific cytodiagnosis is possible in recurrences, metastases and cases of NF1 or a preexisting neurofibroma.

Adult↗
PubMedDate not supplied

HIV-1 (p24)-positive multinucleated giant cells in HIV-associated lymphoepithelial lesion of the parotid gland. A report of two cases.

BACKGROUND: Cystic benign lymphoepithelial lesion (CBLL) is a well-recognized parotid disorder the diagnosis of which can be made on the basis of clinical findings, human immunodeficiency virus (HIV) testing, image studies and fine needle aspiration (FNA). Most aspirations are cystic, and the lesion can be recognized if the triad of foamy macrophages, lymphoid and epithelial (squamous) cells is observed. CASES: The authors recently observed FNA cytologic features of two HIV-associated cases that exhibited numerous multinucleated giant cells (MGCs) but failed to show the epithelial component. A subsequent surgical resection was performed in one patient. Similarly to what has been described for nasopharyngeal (adenoid and tonsil) lymphoid tissue of HIV-positive patients, intense immunoexpression of S-100 and p24 (HIV-1) protein was present in MGC. CONCLUSION: The diagnosis of HIV-associated CBLL should always be considered if a parotid cystic lesion presents with numerous MGCs. Immunocytochemical detection of p24 (HIV-1) protein in MGC becomes a very useful diagnostic aid and extends to parotid CBLL many of those pathogenic features of HIV-1 infection already noted in other HIV-1-infected, lymphoid oropharyngeal lesions.

Adult↗
PubMedDate not supplied

Posttransplant CD30 (Ki-1)-positive anaplastic large cell lymphoma. Report of a case with presentation as a pleural effusion.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) are almost always of B-cell derivation and have a strong association with Epstein-Barr virus (EBV). Only rare cases of CD30 (Ki-1)-positive anaplastic large cell (ALC) lymphomas in transplant recipients have been described. EBV has been studied in few of these cases. Pleural effusion is an uncommon clinical manifestation of both PTLDs and CD30-positive ALC lymphoma. CASE: A 60-year-old, male renal transplant recipient presented with fever and pleural effusion. Cytologic examination of the effusion revealed a large cell lymphoma. Immunocytologic studies disclosed a T-cell phenotype. Subsequently a cutaneous lesion and an accessory spleen were observed, and cervical lymphadenopathies developed. Fine needle aspiration of lymph nodes confirmed the presence of lymphoma. Histologic and immunohistochemical studies of the lymph nodes, skin and accessory spleen revealed the presence of CD30-positive, T-cell, ALC lymphoma. No EBV DNA was detected by polymerase chain reaction analysis. Despite chemotherapy, the patient died seven months after the initial cytologic diagnosis of lymphoma. CONCLUSION: CD30-positive ALC lymphomas are an uncommon variant of PTLDs that should be considered in the differential diagnosis of neoplastic disorders arising in immunosuppressed patients. Cytology and immunocytochemistry are useful diagnostic procedures for their early detection.

Antigens, CD↗
PubMedDate not supplied

Biological comparison between three clones of Trypanosoma cruzi and the strain of origin (Bolivia) with reference to clonal evolution studies.

After isolating three clones of Trypanosoma cruzi (Bolivia), we first characterized them according to parasitaemia, pleomorphism and virulence, and then histopathologically. The study's interest lies on the hypothesis that clonal evolution of T. cruzi has a major impact on biologically relevant properties of this parasite. Data obtained from the studies of parasitaemia, pleomorphism and virulence showed no differences between the groups studied. As a final point, the histopathological study shows us a muscular tissue tropism both in clones and in their mother strain (Bolivia). In this paper, we conclude that Bolivia strain and clones isolated from it, pertaining to the same major clone share similar biological properties.

Animals↗
PubMedDate not supplied

Characterization of a Trypanosoma rangeli strain of Colombian origin.

A Colombian strain of Trypanosoma rangeli was characterized by analyzing its behaviour in different axenic and cellular culture, its infection rate and the histopathological lesions produced in experimental animals. Although slight inflammatory infiltrations were shown in different histopathological sections, no pseudocysts could be observed. Grace's insect medium is better than liver infusion tryptose or artificial triatomine urine supplemented with proline when studying T. rangeli metacyclogenesis, with a peak of 32% trypomastigotes. High infection rates were found in VERO and J774 cells. Because of its 100% infectivity rates and adequacy of parasitemia levels, C23 strain is a suitable model of T. rangeli biology study.

Animals↗
PubMedDate not supplied

Ultrastructure of 26 cases of Ki-1 lymphomas: morphoimmunologic correlation.

Twenty-six cases of high-grade lymphomas with activation markers (CD30) classified and immunophenotyped according to the Kiel classification were studied to determine their fine structural features. Transmission electron microscopy showed in 17 cases anaplastic nuclear and cytoplasmic changes identical to those observed in Hodgkin's disease, it being impossible to determine by the morphology a B, T, or null nature. Four high-grade B-centroblastic and immunoblastic cases and five T-pleomorphic cases showed nuclear changes and cytoplasmic differentiation that suggested a T or B nature. An immunogold-labeling technique showed CD30-positive particles primarily in the Golgi complex and occasionally in the cell membrane.

Antigens, Differentiation↗
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Adrenal gland leiomyoma in a child with acquired immunodeficiency syndrome.

An adrenal gland leiomyoma was incidentally found at autopsy in a 2-year-old boy with acquired immunodeficiency syndrome (AIDS). Smooth muscle neoplasms have been described in pediatric AIDS and affect mainly the tracheobronchopulmonary, gastrointestinal, and hepatobiliary systems. An association between Epstein-Barr virus (EBV) and smooth muscle tumors in patients with AIDS has been described. This case is the first leiomyoma to be reported in the adrenal gland of a child with AIDS. EBV genome was demonstrated in the tumor by polymerase chain reaction.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

[Pseudomelanoma].

Explore the source record for details and available documents.

Aged↗
PubMedDate not supplied

[Lipomatous hypertrophy of the interauricular septum, fibrosis of the bundle of His and calcification of the mitral annulus associated with multiple rhythm and conduction disorders. The anatomicoclinical correlations].

We present the case of a 72 years old female with multiple episodes of atrial fibrillation, interatrial block and different degrees of atrioventricular block, that died because of stroke. Postmortem pathologic examination showed a lipomatous hypertrophy of the interatrial septum (previously suspected on echocardiogram), his bundle and right branch degeneration as well as mitral annular calcification extended to conduction system. According to these pathologic findings, rhythm and conduction disturbances are correlated with the two levels (atrial and atrioventricular) where anatomic abnormalities were found.

Aged↗
PubMedDate not supplied

Electrophysiologic changes during acute rejection of heterotopically transplanted rat hearts.

Noninvasive monitoring of heart allograft rejection was performed by electrophysiologic techniques using an implanted electrode located on the epicardial surface of the heterotopic transplanted heart of rats. R wave and slew rate determinations were performed daily in 30 syngeneic and 66 allogeneic transplants. These determinations were later compared with histopathologic studies of the transplanted hearts. R wave and slew rate values of allogeneic or rejecting hearts were found to decrease significantly compared with syngeneic or nonrejecting hearts on the days studied. This noninvasive electrophysiologic method may be a promising method for monitoring heart allograft rejection.

Abdomen↗
PubMedDate not supplied

[Dendritic cells in chronic adult periodontal disease].

At the gingiva there are two cellular populations with mediation capacity in the immunoregulation, whose mechanisms seen to be implicated in the pathogenesis of the periodontal disease. One of these populations is formed by the macrophages and the other one by the Langerhans cells belonging to the epithelia. In this paper wr are demonstrating that both populations keep an inverse proportional relation in the two sides of gingival epithelium. In the oral side, the Langerhans cells are predomiating, while in the periodontal pocket they are in small number, in comparison with the macrophages, which are highly abundant and forming a subepithelial band.

Adult↗