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Biomedical subjects

F G Rodrigo

Publications and source records attributed to F G Rodrigo.

At least 19 recordsLinked to original sources
PubMed1997

Lipid peroxidation in type 2 normolipidemic diabetic patients.

Vascular complications, as a consequence of atherosclerosis, are the main causes of morbidity and mortality in diabetes. Low density lipoprotein (LDL) oxidation is accepted as a relevant pathogenic mechanism in atherogenesis. The aim of this work was to study the relationship between lipid peroxidation (LPO) and metabolic control. LPO was evaluated in 40 type 2 normolipidemic diabetic patients by measuring thiobarbituric acid reactive substances (TBARS), in the plasma, using malondialdehyde (MDA), end product of the oxidation of polyunsaturated fatty acids, as a standard. Fast blood glucose (FBG), serum total cholesterol (TC) and serum triglycerides (TG) were evaluated by routine methods. Fructosamine (FR) was measured by the nitroblue tetrazolium (NBT) colorimetric test. An elevated level of lipid peroxides (P < 0.001) was observed in the plasma of diabetic patients (4.51 +/- 1.29 nmol/ml) as compared to normal subjects (3.54 +/- 1.00 nmol/ml). Lipid peroxides did not correlate with the FR levels, nor with FBG, TC and TG. These results show an increase of LPO in type 2 normolipidemic diabetic patients. Probably the mechanism for higher lipid peroxide levels in diabetes is multifactorial. Our study supports the hypothesis of a role of oxidative stress in diabetes independently of the lipid serum content.

Aged↗
PubMed1997

[Dermatitis artefacta].

We report a case of a 29-year-old man presenting skin ulcerations on both sides of the mandible. The diagnosis of dermatitis artefacta was based on the morphology and evolution of the lesions, on the patient's borderline personality, on the objects found in his possession, and a later admission of having an involvement in the aggravation of the lesions.

Adult↗
PubMed1995

[Lipid peroxidation, production of PGE2 and cellular mortality induced by UV in cultured human skin fibroblasts].

UV irradiation induces lipid peroxidation (LPO) and cell damage. The aim of the present work was the study of UVB radiation effects on cultured human skin fibroblasts, concerning LPO, prostaglandine E2 (PGE2) formation and cell viability. The cells were exposed to 50, 100, and 150 mJ/cm2 of UVB irradiation. Cellular TBARS and supernatant fluorescent substances were measured spectrofluorimetrically. PGE2 was measured using an immunoenzymatic method. Cell viability was evaluated by the MTT test. All determinations were done after a 2 h incubation period post-irradiation. TBARS were increased for all doses of irradiation (p < 0.001). Fluorescent substances differed from controls at 50 mJ/cm2 (p < 0.001). UVB at 100 and 150 mJ/cm2 decreased cellular viability (p < 0.001). An increase of PGE2 was observed with UVB at 150 mJ/cm2 (p < 0.001). These results confirm the occurrence of LPO and cytotoxicity after UV irradiation; on the other hand, this study showed the formation of PGE2 induced by UV light on cultured human skin fibroblasts. We propose a relationship between these phenomena.

Cell Death↗
PubMed1992

[Malignant melanoma. A current problem].

Malignant Melanoma is a tumor of high malignancy which incidence has been shown to increase dramatically during last decades. The genesis of the tumor is uncertain, however the cutaneous fair complexion, the number and type of pigmented nevei and acute intermittent sun exposure with sunburn may play a significant role in its development. Histopathology of suspicious lesions is obligatory as diagnostic proof and to measure the tumor thickness and the skin invasion level. Distinct therapeutic attitudes are reviewed. Correct surgical excision is essential in localized primary lesions. The two main factors regarding surveillance and survival of patients afflicted with Malignant Melanoma are precocious diagnosis of early lesions and quick surgical intervention. On a prophylactic ground, for the early detection of Malignant Melanoma, one should point out the need for a complete and careful skin observation of every individual in current medical examinations.

Humans↗
PubMed1981

[Visualization of oxitalan fibers in normal human skin by the alkaline tetrazolium test].

The "elastic system" of the connective tissue includes the oxytalan, the elaunin and the elastic fibers. The oxytalan fibers are formed by the microfibrillar component of the elastic fibers (elastic microfibrils). In the human skin the oxytalan fibers are found in the papillary dermis perpendicularly oriented to the dermo-epidermal junction. It was previously demonstrated by biochemical analysis that sulfur amino acids are present in the elastic microfibrils. Based on these data we could visualize the oxytalan fibers in the human dermis using the nitroblue tetrazolium (NBT) technique.

Amino Acids↗
PubMed1979

Connective fibers involved in the dermoepidermal anchorage. An electron microscopical study.

The human dermoepidermal anchoring fibrils, the oxytalan fibers and the elaunin fibers have been related with dermoepidermal adherence. In the present work their ultrastructure and origin are studied. The similarity between the segment longspacing tropocollagen molecular aggregates and the anchoring fibrils band patterns is evidenced. This fact supports the concept that the anchoring fibrils may be formed by a mechanism of side by side tropocollagen molecular aggregation after its polar binding to the basement lamina. The oxytalan fibers were studied in the superficial dermis, and their direct continuity with the elaunin fibers was demonstrated. The role of these fibers in the dermoepidermal mechanical adhesion is discussed.

Adult↗
PubMed1977

The elastic system fibers.

Using the tannic acid-glutaraldehyde fixation it was possible to clearly visualize, with reproducible results, the elastic fiber amorphous material because of its density. The microfibrillar component was also evidenced with a good performance. With this technique the ultrastructural patterns of the oxytalan and elaunin fibers were also demonstrated. The oxytalan fibers appeared as a bundle of microfibrils similar to elastic microfibrils without amorphous material. The elaunin fibers presented a dispersed amorphous material intermingled among the microfibrils. It was suggested by ultrastructural evidences that oxytalan and elaunin fibers may represent interruption in successive phases in the development of the elastic fibers.

Elastic Tissue↗
PubMed1976

The use of tannic acid-glutaraldehyde in the study of elastic and elastic-related fibers.

Fixation with tannic acid-glutaraldehyde permits distinction of oxytalan, elaunin and elastic fibers in the electron microscope. The results obtained using tannic acid at concentrations of 1.0%, 0.5% and 0.25% in 3% glutaraldehyde were compared. The 0.25% concentration is recommended for studying fine details of connective fibrils and for regular staining of elastin.

Aldehydes↗
PubMedDate not supplied

[Crohn disease with unusual cutaneous expression].

Perianal fistula is a frequent complication of Crohn's disease. The diagnosis of the later may be difficult if cutaneous disease is dominant, and sometimes an important clinical challenge. The authors report a case of a 34 year old male complaining of painful perianal nodules for the three last years. Cutaneous histopathological examination was inespecific and colonoscopy normal. Pelvic CT scan and fistulography showed an intercommunicated fistular system invading both isquiorectal fossae, without intestinal communication. Repetition of colonoscopy showed normal mucosa, but in two of the biopsy samples noncaseous granulomas were found at the submucosa. The authors explain their main difficulties to reach the diagnosis of Crohn's disease and discuss the investigation and the evolution of the patient.

Adult↗
PubMedDate not supplied

[Epidermolysis bullosa and dermo-epidermic junction. Clinico-pathologic correlation].

Epidermolysis bullosa encompasses a group of hereditary diseases clinically and pathologically characteristic. In this review the grouping criteria commonly accepted for their classification are described. The cleavage phenomena observed in these diseases are analysed in accordance with the concept of a skin area including dermal and epidermal interrelated structures--the dermo-epidermal junction zone. Finally in the most expressive forms the clinical manifestations, diagnosis and treatment are reviewed.

Epidermis↗
PubMedDate not supplied

[Skin aging. Physiopathology and clinical perspective].

The main structural and functional alterations observed during skin ageing are reviewed, considering the intrinsic process of senescence and the damage induced by chronic exposure to actinic radiation. In photo-ageing the importance of skin type is stressed, concerning its capacity to tan in order to get protection against radiation. Finally some inflammatory, degenerative and neoplastic skin diseases associated with ageing and photo-ageing are briefly described.

Humans↗