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Biomedical subjects

A Castells

Publications and source records attributed to A Castells.

At least 109 records · Page 6Linked to original sources
PubMed1990

Inhibition of gamma-glutamyl transpeptidase decreases amino acid uptake in human keratinocytes in culture.

Acivicin inhibits gamma-glutamyl transpeptidase activity in human keratinocytes in culture. Treatment of these cells with acivicin produces a decrease in the uptake of L-[U-14C]alanine, 2-amino-[1-14C]-isobutyrate, L-[U-14C]leucine and 1-aminocyclopentane-1-[14C]carboxylate. D-[U-14C]glucose uptake is not affected by the presence of acivicin. These results support, for the first time in vitro, the hypothesis that the gamma-glutamyl cycle may be involved in amino acid uptake by human cells.

Amino Acids↗
PubMed1990

Diarrhea as a presenting symptom of hepatocellular carcinoma.

The clinical manifestations of hepatocellular carcinoma (HCC) are highly nonspecific since they usually mimic those of hepatic cirrhosis, which frequently underlies this neoplasm. The fact that some HCC patients present with severe diarrhea, an unusual symptom in liver cirrhosis, prompted us to determine the prevalence of diarrhea in a series of 23 consecutive HCC patients and compare it with that of a control group formed by cirrhotic patients without HCC, matched by age, sex, and etiology of the liver disease. All the patients were interviewed about the existence of diarrhea (defined as the presence of three or more loose stools per day appearing over three or more days) in the three months prior to admission. Both groups of patients were similar in regards to the degree of liver failure and presence of diarrhea-favoring factors. By contrast, diarrhea was significantly more frequent among HCC cases than among cirrhotics without HCC (47.8% vs 8.7%, P less than 0.005). HCC patients with diarrhea exhibited higher alkaline phosphatase and bilirubin levels and worse liver function, assessed by the Child-Pugh's classification, than patients without diarrhea. However, neither tumor size, vascular invasion, or the degree of tumor differentiation were significantly different between these two groups of HCC patients. These results show that diarrhea is a frequent manifestation of HCC in patients with cirrhosis. Therefore, the development of HCC in these patients should be suspected upon the appearance of diarrhea.

Adult↗
PubMed1990

Distribution of involucrin in normal and pathological human uterine cervix.

A study was undertaken to determine the potential value of involucrin immunostaining, a protein synthesized by mature squamous epithelial cells, in distinguishing benign from neoplastic lesions in cervical pathology. A total of 146 cervical biopsies were analyzed using an indirect immunoperoxidase method and polyclonal antibody. A suprabasal homogeneous cytoplasmic staining pattern was consistently observed in normal squamous cervical epithelium. In contrast, 43.7% of cervical condylomas showed involucrin at all levels of the epithelium including the basal layer. Variable patterns were seen in cervical intraepithelial neoplasia (CIN), with 46% of full-thickness stainings, although no significant difference was obtained among the different grades of CIN lesions. Distribution of involucrin was correlated (P less than 0.05) with the degree of tumor differentiation in squamous cell carcinomas, being absent in 71.4% of poorly differentiated carcinomas and focally present in 75% of well-differentiated carcinoma. Lesions of endocervical origin, either benign or malignant, were entirely negative for involucrin. It is concluded that involucrin seems unable to establish a reliable differential diagnosis between benign and neoplastic conditions in cervical pathology, and should therefore be considered only a specific marker of squamous differentiation in both normal and pathological human uterine cervix.

Adult↗
PubMed1990

[Toxic megacolon and intestinal perforation caused by Salmonella enteritidis].

Two cases of colitis due to Salmonella enteriditis which later developed a toxic megacolon with intestinal perforation are presented and the probable pathogenesis is discussed. This exceptional clinical course which has not been previously described forces to perform a differential diagnosis with chronic intestinal inflammatory disease which must be based on microbiologic, serologic and/or histologic criteria. Moreover, the authors warn about the unsuitability of using anticholigernic drugs in gastroenteritis since they could be related to the ethiopathogenical basis of the disease's unfavorable course in the described patients.

Adult↗
PubMed1989

Distribution of epithelial antigens in the human uterine cervix: a review.

Epithelial antigen immunostaining in the uterine cervix has been claimed to be helpful in the identification and classification of rare lesions, evaluation of basement membrane integrity, study of atypical condylomas, immunodetection of proliferating processes and early diagnosis of malignant transformation. The present review attempts to demonstrate the potential value of immunohistological techniques as a means of identifying normal and abnormal patterns of antigenic expression in cervical epithelium.

Antigens, Neoplasm↗
PubMed1989

Precocious appearance of markers of squamous differentiation in metaplastic cells of human endocervix.

We used immunoperoxidase methods employing antibodies against involucrin and filaggrin, both markers of squamous terminal differentiation, to study squamous metaplastic transformation in the human endocervix. Expression of involucrin and filaggrin was restricted to squamous metaplastic cells whereas columnar epithelial cells were constantly negative. Immature squamous metaplastic epithelium also showed a positive immunostaining. In mature squamous metaplasia a suprabasal homogeneous staining pattern similar to that found in the exocervical epithelium was detected, although with full-thickness filaggrin immunoreactivity in 45% of cases (P less than 0.05). These results support the hypothesis of an epithelial origin of reserve subcolumnar cells, and suggest that precocious squamous differentiation seems to take place in metaplastic cells of the human endocervix.

Adult↗
PubMed1989

[Oral hairy leukoplakia. A study of 5 cases].

Oral hairy leukoplakia (HL) is a newly described lesion (1984) in human immunodeficiency virus infected patients. Patients with HL show a high probability of developing an acquired immunodeficiency syndrome (AIDS). The results of histopathological, microbiological, immunological and ultrastructural studies in five patients with HL and AIDS are reported. The histopathological exam revealed in all cases acanthosis, parakeratosis, koilocytosis and keratin projections on the surface. Dermis was normal. Herpes type virus were seen in four cases and in one of them papilloma virus was also present in electron microscopic examination. There was immunocytochemical evidence of papilloma virus in one lesion. Candida albicans was found in 5 lesions by culture but only in two ones by periodic acid Schiff stain. Virus cultures for herpes virus were negative. Immunocytochemical search of Langerhans cells (S-100, HLA-DR, OKT4, OKT6) showed nearly absence of these cells in HL lesions. These results favour the viral etiology hypothesis of hairy leukoplakia.

Acquired Immunodeficiency Syndrome↗
PubMed1987

[Distribution of Langerhans cells in spinocellular epitheliomas].

The authors perform and study about Langerhans cell's distribution on squamous cell carcinomas and on one ecrine porocarcinoma. We used OKT6 and HLA-Dr antigens with fluorescein. We observed a higher density of these cells on the tumors more differentiated. On the other hand, we have seen that tumoral cells of the ecrine porocarcinoma display HLA-Dr antigens.

Adenoma, Sweat Gland↗
PubMed1987

[Densitometry study of the Langerhans cells in human skin].

A densitometric study of Langerhans cells with ATPase technique is made. 62 samples of normal skin were studied. The buttocks and upper limbs showed the highest density of Langerhans cells. No differences related to age and sex were found.

Adenosine Triphosphatases↗
PubMed1986

[Autoantibodies in vitiligo. Clinical significance].

The occurrence of circulating autoantibodies was determined by indirect immunofluorescence in patients with vitiligo. In addition we determined the existence of anti-melanocytic antibodies by an immunofluorescence complement fixation technique, immunoglobulins in achromic and perilesional skin, complement (C3 and C4) and immunoglobulins in serum by immunoelectrophoresis. The results only indicate that a significant occurrence of circulating autoantibodies exists, especially antithyroid autoantibodies, which, moreover, are related to the vitiligos which affect important areas of the cutaneous surface (generalized vitiligo).

Autoantibodies↗
PubMed1986

[Netherton syndrome].

The authors reported a case of Netherton's syndrome. This patient presented cutaneous lesions of ichthyosis linearis circumflexa, tricorrexis invaginata and atopy signs associated with cystinuria. Cutaneous and hair lesions were treated with etretinate.

Cystinuria↗
PubMed1985

Thymopentin treatment in patients with chemotherapy-resistant lepromatous leprosy.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae; it is chiefly involving the skin and peripheral nerves. In lepromatous leprosy there are widespread loose infiltrates with M. leprae multiplying extensively in the skin macrophages and Schwann cells of peripheral nerves. Such patients reveal a decrease of circulating T helper cells, which is still more pronounced in the cutaneous lesions. Due to the ever increasing bacterial resistance to classical dapsone and combined chemotherapy as well, an immunomodulatory approach seemed reasonable: Eight patients with long-lasting (5-40 years) disease who had become resistant to combined chemotherapy were treated with thymopentin, 50 mg s.c., 3 times weekly for 5 weeks and thereafter combined with dapsone and clofazimine for 5 months. During the trial a statistically significant increase in E-rosette-forming cells (p less than 0.05) was observed, along with a steady improvement of the bacterial status of the nasal mucus. Although the skin lesions did not disappear within the observation period of the study, it is important to realize that long-term improvement of such lesions is always initiated by clearance of bacilli from the nasal mucus, hence, thymopentin treatment appears to be a promising approach to chemotherapy-resistant lepromatous lepra.

Adjuvants, Immunologic↗
PubMed1985

[Carcinoma of the sebaceous glands].

A case of sebaceous gland carcinoma is reported. The patient, a woman aged 70, presented the lesion at the age of 17; it was destroyed by electrocoagulation, but recurred and was excised when she was 70. Histology showed a sebaceous gland carcinoma. No metastasis occurred in the long term evolution.

Adenocarcinoma↗