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Biomedical subjects

F Contreras

Publications and source records attributed to F Contreras.

At least 19 recordsLinked to original sources
PubMed1996

Growth hormone response to growth hormone releasing hormone in non-delusional and delusional depression and healthy controls.

Growth hormone (GH) responses to growth hormone releasing hormone (GHRH) of 53 in-patients meeting DSM-III-R criteria for major depressive episode with melancholia (24 non-delusional and 23 delusional depression) were compared with those of 19 healthy controls. No significant differences in basal GH were found between the control and either the non-delusional or the delusional groups. The whole group of depressed patients showed a significantly lower response than the control patients at all points of the GH response to GHRH curve as well as a lower area under curve. When the three groups (control, delusional, and non-delusional depressed) were compared, it was found that only the non-delusional depressed patients had a significantly lower area under curve and lower values at +60, +90 and +120 min than the controls. The only significant difference between the two groups of depressed patients was that the delusional group showed a delayed appearance of the maximum response peak and a more prolonged response.

Adult↗
PubMed1996

Neural variant of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome.

A 15-year-old boy with the characteristic features of the naevoid basal cell carcinoma syndrome presented with a retroperitoneal mass. The tumour showed morphological features of a still ill-defined variant of fetal rhabdomyoma, characterized by well-differentiated nerve fibres admixed with immature striated muscle cells, similar to neuromuscular choristoma. Four cases of fetal rhabdomyoma and naevoid basal cell carcinoma syndrome have been previously reported. The behaviour of this tumour has been benign, although a complete excision was impossible due to its close relation with abdominal vascular trunks.

Adolescent↗
PubMed1995

Differential patterns of placental and epithelial cadherin expression in basal cell carcinoma and in the epidermis overlying tumours.

P-cadherin (P-CD) and E-cadherin (E-CD) are expressed by keratinocytes and play an important role in skin morphogenesis. P-CD expression is restricted to the basal layer of normal epidermis, whereas E-CD is expressed in all the living layers. We have previously reported a reduced expression of E-CD in most cases of infiltrative basal cell carcinoma (BCC). In the present work we have investigated by immunohistochemistry the expression of both P-CD and E-CD in a new series of 32 patients with BCC. Most cases of superficial multicentric BCC and some nodular tumours had preserved expression of both cadherins in all tumour cells. The majority of nodular BCCs had partially reduced expression of one or both cadherins with an ordered distribution of cells showing different cadherin staining throughout the tumour mass. A severe reduction of E-CD expression with a disordered distribution of cells with different immunostaining intensity was observed in most specimens of infiltrative BCC. In contrast, P-CD expression was preserved in all cases of infiltrative BCC. These results suggest that P-CD and E-CD play different roles in the growth pattern of BCC. In addition, both anomalous P-CD expression and reduced E-CD expression were frequently observed in the spinous layer of epidermis overlying tumours. This phenomenon was significantly associated with the presence of keratinocytic atypia, which suggests that disturbed cadherin expression could be a marker of premalignant changes and/or hyperproliferative activity in human epidermis.

Aged↗
PubMed1995

p53 protein expression in viral warts from patients with epidermodysplasia verruciformis.

The p53 protein is the product of a tumour suppressor gene, which is implicated in many human malignancies. p53 expression was investigated by immunohistochemistry in a series of viral warts (n = 12) from five patients with epidermodysplasia verruciformis (EV), using a monoclonal anti-p53 antibody (DO7). p53 expression was also investigated in a series of common warts (n = 8), flat warts (n = 8), and penile bowenoid papulosis (n = 6) from non-EV patients. Immunostaining was positive in 11 of 12 (92%) EV warts, whereas p53 reactivity was negative in most cases of warts from non-EV patients. Exons 5-8 of the p53 gene were screened by the polymerase chain reaction-single strand conformation polymorphism technique in four EV warts, which were strongly stained for p53, and p53 mutations were not detected. These results suggest an association between p53 accumulation (probably of wild type) and EV warts.

Epidermodysplasia Verruciformis↗
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↗