PubMed Health⌕ Search

Biomedical subjects

F Contreras

Publications and source records attributed to F Contreras.

At least 37 records · Page 2Linked to original sources
PubMed1994

E-cadherin expression in basal cell carcinoma.

E-cadherin (E-CD) is a calcium-dependent cell-cell adhesion molecule which is expressed in almost all epithelial tissues. E-CD expression is involved in epidermal morphogenesis and is reduced during tumour progression of mouse epidermal carcinogenesis. It has been suggested that E-CD could play a role as an invasion-suppressor molecule. In the present work we have studied the E-CD expression in 31 patients with basal cell carcinoma (BCC) using an immunohistochemical technique with a monoclonal antibody (HECD-1) specific for human E-CD. E-CD expression was preserved in all specimens of superficial and nodular BCC, and was reduced in 10 of 15 infiltrative BCCs. A heterogeneous distribution of cells with different immunostaining intensity was more frequently observed in specimens of infiltrative BCC. These results suggest that E-CD might be related to the growth pattern and the local aggressive behaviour of BCC, and support the idea that E-CD might play a role as an invasion-suppressor molecule in vivo.

Adult↗
PubMed1994

Chondroid metaplasia in the tunica media of the aorta in dogs submitted to saphenous vein aorto-cava by-pass.

We submitted twelve dogs to aorto-superior vena cava by-pass with saphenous vein. Six months later, all dogs had developed areas of chondroid metaplasia in the tunica media of the aorta, near the area of anastomosis. Three dogs also had bony metaplasia. The Foci of metaplasia had no relation to sutures. This lesion begins with a build-up store of glycosaminoglycans in the tunica media. Later, elastic fibers show a fenestration and dissolution, while chondrocytes replace smooth muscle fibres. We suggest that the rupture of the vasa vasorum during operation and the traction and pulsation of the by-pass over the area of suture could be the cause of this direct metaplasia.

Anastomosis, Surgical↗
PubMed1993

Ophthalmic pathology laboratories in Latin America.

Ocular pathology laboratories have been one of the main reasons for the progress and evolution of ophthalmology in Latin America. This has been made possible through pathologic reports, meetings, and seminars and through the valuable help of basic teaching in residency programs in ophthalmology.

Clinical Laboratory Techniques↗
PubMed1993

Papular xanthoma in children: report and immunohistochemical study.

Papular xanthoma was diagnosed in a 14-month-old boy. The eruption cleared spontaneously within four years. Immunohistopathologic study revealed that the predominant foamy histiocytic cells had the phenotypic features of the dermal dendrocyte. Giant multinucleated cells, which showed characteristics of monocyte-derived macrophages, were also present. We suggest classifying diseases derived from dermal dendrocytes into a separate group of histiocytoses.

Giant Cells↗
PubMed1993

Histological outcome of chronic hepatitis C treated with a 12-month course of lymphoblastoid alfa interferon.

To assess the effect of long-term alfa interferon therapy (12 months) on liver histology of chronic hepatitis C, we studied 61 treated patients, and compared their outcome with 28 untreated cases followed as controls. A liver biopsy was taken from all patients, before (month 0) and after the completion of the treatment or the control period (month 12). A third liver specimen taken at month 24 was available in 29 treated cases. Liver biopsies were blindly graded following Knodell's method. In 33 out of the 61 treated patients (54.1%), aminotransferase levels became normal shortly after starting therapy and remained within normal values until the end of treatment (sustained response). Nine (27%) sustained responders relapsed after interferon discontinuation, while the remaining 24 (73%) continued with normal aminotransferase values during follow-up (16.8 +/- 9.9 months). All histological parameters, except fibrosis, improved significantly after 12 months of therapy (periportal necrosis, month 0: 2.7 +/- 1.0, month 12: 1.6 +/- 1.1, p < 0.0001; lobular damage, month 0: 2.5 +/- 1.1, month 12: 1.4 +/- 0.9, p < 0.0001; portal inflammation, month 0: 3.6 +/- 0.5, month 12: 3.0 +/- 0.9, p < 0.0001). Histological improvement was especially marked in patients who did not relapse, although those who relapsed and partial responders also improved. Overall histological diagnoses improved in most patients. A sustained response to interferon was predicted by high periportal and lobular scores, and by a low fibrosis score on the pretreatment liver biopsy. At 24 months, histological improvement persisted in patients without posttreatment relapse, while liver inflammation had returned to pretreatment levels in the remaining cases.

Adult↗
PubMed1993

[Malignant fibrous histiocytoma of the pancreas].

Malignant fibrous histiocytoma (MFH), a frequent sarcoma in retroperitoneal mesenchimal tissues, has also been reported, although in a few cases, in digestive viscera. We present a case of a primary MFH of the pancreas in a 37-year-old male, treated with a 90% distal pancreatectomy, plus external and intraoperative radiotherapy over the tumoral bed, and polychemotherapy. Response to treatment was poor, with early local recurrence, liver and bone metastases and a survival of 7 months. Only 4 other cases of MFH of the pancreas have been reported. We analyze these 5 cases: they have been usually diagnosed in young adults, with vague symptoms and large tumoral masses without jaundice. Local recurrence seems to be frequent; they develop liver metastases rather than lung metastases. Even when they are resectable, the anatomical relations of the pancreas with vital vascular structures make broad resection difficult, and local recurrences frequent. Analysis of these five reported cases of MFH of the pancreas, allows to expect a local recurrence rate higher than 50% and a 5-year-survival rate lower than 30% due to distant metastases. Only radiotherapy seems to play a role as an adjuvant treatment after surgery for pancreas and other retroperitoneal sarcoma as it significantly increases survival.

Adult↗
PubMed1992

Long-term undiagnosed syphilis with clinical presentation of meningitis.

A 43-year-old woman, with an 11-year history of progressive cutaneous lesions, was considered to have granuloma annulare and was treated as such for 4 years. She then developed chronic meningitis. Serological investigation revealed active syphilis. Appropriate antibiotic treatment led to a rapid resolution of the clinical symptoms. The recent reports of similar cases indicate the importance of an adequate knowledge of clinical manifestations and pathological patterns of syphilis.

Adult↗
PubMed1991

[Kaposi's sarcoma associated with chronic B lymphocytic leukemia. Coexistence of both diseases in skin lesions].

Kaposi's sarcoma is a rare malignancy. Its association with second primary cancers, especially of the lymphoreticular system, has been relatively frequently noted. We report a case of Kaposi's sarcoma (SK) in a 62 years-old women, affected by B-cell chronic lymphocytic leukemia (LLC B) for 22 month, that had received chemotherapy. Two skin lesions were seen on left lower limb. A biopsy revealed the coexistence of both diseases in the skin lesions. This finding is extremely rare. We review the possible etiopathogenic implications of this association and of the coexistence of both diseases in the same lesion.

Female↗
PubMed1991

Histiocytic cytophagic panniculitis: report of a case in a 12-year-old girl.

We report a 12-year-old girl with nodular skin lesions, fever, pancytopenia, coagulation defects and a fatal outcome within 4 months. Histopathology revealed proliferation of histiocytes with haemophagocytosis in skin, perivisceral fat and haemopoietic organs. The symptoms were most consistent with cytophagic histiocytic panniculitis.

Blood Coagulation Disorders↗
PubMed1991

Neonatal lupus erythematosus with multisystem organ involvement preceding cutaneous lesions.

Here we report a case of neonatal lupus erythematosus syndrome presenting with multisystem organ involvement, including anemia, thrombocytopenia, purpura, bloody diarrhea, enzymatic liver abnormalities, splenomegaly and pneumonitis. These findings preceded the cutaneous rash that was the clue for the diagnosis. The patient's mother had an undiagnosed subacute cutaneous lupus erythematosus. The various forms of onset of neonatal lupus erythematosus syndrome are emphasized.

Adult↗
PubMed1990

Screening and surgical intervention results from cataract-free-zone projects in Campinas, Brazil and Chimbote, Peru.

Two cataract-free-zone projects, one in Brazil and the other in Peru, were designed to provide surgery to all those who need and want it within a defined geographic area. In-home visual acuity screening was accepted by three-fourths of the enumerated population aged 50 years or more. Those with reduced bilateral visual acuity were referred to a community health post for ophthalmic examination. Among those diagnosed as bilaterally blind (less than or equal to 20/200), comprising 5% of the screened population, two-thirds were thought to be blind from cataract. Because of other ocular pathology and general health conditions, surgery was not indicated for 30-50%. Two-thirds of those recommended for out-patient surgery accepted. Motivational efforts to convince the refusers were uniformly unsuccessful. The average age of those accepting and those refusing surgery was in the mid-seventies. Those already aphakic were 7-8 years younger. Post-operative acuity was greater than or equal to 20/50 for only one-half of those operated. A significant number of cases had previously undetected macular degeneration and other causes of decreased vision. These projects have given increased attention to cataract blindness and the need for further operational research to develop effective methods for its control using outpatient surgery.

Aged↗
PubMed1990

Multiple self-healing indeterminate cell lesions of the skin in an adult.

We report a case of multiple cutaneous indeterminate cell proliferative lesions in an adult without any other organ involvement. All lesions regressed spontaneously over 5 years without recurrence over a 4-year period of follow-up. The electron-microscopic and immunohistochemical features of the cellular infiltrate were those of the indeterminate cells. This case supports the hypothesis that indeterminate cell proliferative disorder is a wide spectrum of conditions with variegated clinicopathologic presentation and with different biological behavior.

Cell Line↗
PubMed1990

The natural history of vasculitis. What the histology tells us about pathogenesis.

While histopathologic analysis may offer some clues as to the pathogenesis of vasculitis, observations must be interpreted with caution, as there is considerable overlap in the histologic pattern. In most cases, a predominantly neutrophilic vasculitis affecting small dermal venules suggests a relatively acute, immune complex-mediated reaction. Less commonly, this histologic pattern may be seen in non-immunologically mediated processes, such as in the presence of bacterial toxins or malignant hypertension, or in more chronic disease states, such as granuloma faciale or erythema elevatum diutinum. A predominantly lymphocytic vasculitis may represent several pathogenetic mechanisms. In lesions more than 24 to 48 hours old, a lymphocytic vasculitis may represent a resolving phase of an immune complex-mediated neutrophilic vasculitis. Alternatively, this histologic pattern may be seen de novo in conditions with a presumed cell-mediated immunologic pathogenesis. Lymphocytic vasculitis may also be seen in rickettsial infections such as Rocky Mountain spotted fever. The pathogenesis of granulomatous vasculitis remains poorly understood and is thought to be induced by a combination of circulating immune complexes and a cell-mediated immune response.

Granuloma↗
PubMed1989

[Multicentric reticulohistiocytosis: histochemical, histoenzymatic and immunocytochemical study].

Report of a case of multicentric reticulohistiocytosis with clinical, histopathologic, histochemical and immunohistochemical study. Neutral mucins and lipids were demonstrated in the cytoplasm of dermal histiocytes. The monocyte-histiocytic nature of the cells was shown by means of acid phosphatase, ATP-ase, muramidase and alpha-1-antitrypsin. Due to the immunohistochemical results, the relationship with Langerhans cells was rejected. No secretory activity of immunoglobulins was shown and the proliferation qualified as benign. The cells among the histiocytic population were typified as mature T lymphocytes.

Adult↗
PubMed1988

Histological reactions of human endometrium to the IUD.

A comparative study was made of four intrauterine contraceptive devices: the Nova-T, MLCu250 Short, MLCu375 and the Gyne T. An endometrial biopsy was performed on the 25th day of the menstrual cycle. The tissue obtained was analyzed to determine endometrial morphology patterns. After two years of IUD use, no inflammatory changes were demonstrated with MLCu375. Histological responses of the endometrium to the IUD depend on the amount of copper in the IUD.

Adult↗