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Biomedical subjects

M Lecha

Publications and source records attributed to M Lecha.

At least 37 records · Page 2Linked to original sources

Urinary porphyrin excretion measurements in healthy neonates.

The objective of this study was to establish normal reference ranges for porphyrins in healthy neonates. There is little information about urinary porphyrin excretion in this age group. This knowledge may provide an early diagnostic tool for detecting subtle alterations or latent forms in disorders of heme biosynthesis. Fifty healthy neonates were selected from the Department of Obstetrics. Total urinary porphyrins in random specimens were analysed by a spectrofluorometry method. The measurement of porphyrin fractions was made by fluorometric high-performance liquid chromatography (HPLC). The results were adjusted to urinary creatinine excretion to correct any imprecision and interindividual variation in body mass. The urinary total porphyrin had a median value of 331.50 (nmol/L). A statistically significant relationship between total porphyrin (nmol/L) and creatinine (mmol/L) was found (p < 0.01). The porphyrin/creatinine ratio showed a median value of 56.30 nmol/mmol creatinine. The study of individual porphyrins revealed that coproporphyrin and uroporphyrin were the major porphyrins excreted in neonates (coproporphyrin represents 81.98% and uroporphyrin 16.64% of total porphyrin); in both cases, isomer I was predominant with median values of 22.36 and 6.25 nmol/mmol creatinine, respectively. No significant relationships were found between porphyrin excretion and sex, gestational age, weight, or height. Our data provide the reference limits for porphyrins in neonates as a diagnostic guideline for evaluation of subtle alterations in heme biosynthesis.

Age Factors↗

Mutations in the ferrochelatase gene of four Spanish patients with erythropoietic protoporphyria.

Erythropoietic protoporphyria is a hereditary disorder of porphyrin metabolism caused by mutations in the ferrochelatase gene. Ferrochelatase catalyzes the chelation of ferrous iron into protoporphyrin IX to form heme. Mutation analysis was performed in four Spanish erythropoietic protoporphyria families resulting in the identification of four different mutations in the ferrochelatase gene. Two of them were novel mutations, a missense mutation (1157 A-->C, H386P) and a frameshift mutation (843delC) found in two Spanish families, respectively. The third and the forth Spanish patients carried already published ferrochelatase gene mutations, a nonsense mutation (343C-->T, R115X) and a missense mutation (557T-->C, I186T), respectively. The newly described frameshift mutation (843delC) predicted formation of an abrupt mRNA. The deleterious effect of His386 to Pro substitution as a result of mutation 1157 A-->C on the ferrochelatase activity was investigated by expressing the mutant ferrochelatase in Escherichia coli. The mutant ferrochelatase exhibited only 0.8% of the wild-type ferrochelatase activity. Prediction of the secondary structure of ferrochelatase suggested that the H386P mutation disrupted the original alpha-helical structure by way of introducing a turn, a rather drastic structural change of the enzyme sufficient to cause activity loss.

Electrophoresis, Polyacrylamide Gel↗

Flutamide photosensitivity--residual vitiliginous lesions.

A case of flutamide photosensitivity is reported in a patient receiving treatment for prostate cancer. Photopatch testing with flutamide at 10 and 20% in acetone was positive and controls negative. Other reports in the literature indicate that flutamide photosensitivity can be produced either by UV-A or UV-B, but the small number of reports and the differences in the tests performed do not allow the specific characteristics of flutamide photosensitivity to be established. Presently it would be advisable, due to the frequent use of this drug, to include flutamide in the investigation of photosensitive patients.

Aged↗

Subacute cutaneous lupus erythematosus associated with cinnarizine and thiethylperazine therapy.

We report the case of a woman who developed subacute cutaneous lupus erythematosus (SCLE) after exposure to the sun while taking cinnarizine and thiethylperazine. The patient recalled that 10 years previously, a similar eruption had appeared after sunbathing, while she was taking only cinnarizine. SCLE development in this patient was probably drug related and there is some evidence that cinnarizine played an important pathogenic role.

Adult↗

A mutation (G281E) of the human uroporphyrinogen decarboxylase gene causes both hepatoerythropoietic porphyria and overt familial porphyria cutanea tarda: biochemical and genetic studies on Spanish patients.

Hepatoerythropoietic porphyria is a severe cutaneous porphyria caused by deficiency of uroporphyrinogen decarboxylase and is considered to be the homozygous form of familial (type II) porphyria cutanea tarda. To elucidate further the relation between these conditions, we studied five Spanish families with hepatoerythropoietic porphyria and nine unrelated Spanish patients with familial porphyria cutanea tarda. Immunoreactive and catalytic uroporphyrinogen decarboxylase was decreased by greater than 95% in the five patients with hepatoerythropoietic porphyria. Hepatic uroporphyrinogen decarboxylase activity was decreased to 22% of normal. Four patients were homozygous for a mutation (G281E) originally identified in a Tunisian family; the fifth patient was a compound heterozygote for this mutation. The calculated carrier frequency for G281E in Spain is one in 1800. None of the nine familial porphyria cutanea tarda patients carried the G281E mutation. However, one G281E heterozygote in a family with hepatoerythropoietic porphyria had overt porphyria cutanea tarda. These findings suggest that the G281E mutation is functionally less severe than erythrocyte measurements indicate, that its clinical penetrance is very low in heterozygotes, and that, for this particular mutation, hepatoerythropoietic porphyria is the homozygous form of familial porphyria cutanea tarda.

Base Sequence↗

Immunopathologic study of skin lesions in dermatomyositis.

To determine the phenotype of skin infiltrates in affected and uninvolved skin from patients with dermatomyositis, immunohistochemical studies with 10 murine monoclonal antibodies were carried out on 25 skin biopsy specimens. Dermal infiltrates consisted predominantly of HLA-DR-expressing macrophages and T lymphocytes, especially of the CD4 subset. B lymphocytes, as defined by positive staining for Leu-12, were absent. Epidermal Langerhans cells were absent or decreased in some areas of affected skin but the total number was normal. OKT6+ cells were present in some dermal mononuclear infiltrates in close contact with lymphocytes. We observed reduced HLA-DR positivity of dermal capillary endothelia. These findings are apparently different from dermatomyositis muscle infiltrates but are similar to those in skin affected by cutaneous lupus erythematosus. Our observations support the concept that, in autoimmune diseases, cellular infiltrates may be more organ-specific than disease-specific.

Antibodies, Monoclonal↗

[Kaposi's sarcoma associated with the acquired immunodeficiency syndrome. An analysis of 67 cases with a study of the prognostic factors].

The features and prognostic factors of 67 cases of Kaposi's sarcoma (KS) associated to the acquired immunodeficiency syndrome (AIDS) diagnosed at the Hospital Clinic, Barcelona, are analyzed. All the patients were male; mean age was 39.7 years, ranging from 22 and 62 years. 64 were homosexuals (95.5%), two were homosexual-drug addicts (3%) and one was drug addict (1.5%). Prevalence of cytomegalovirus and herpes virus infections were 91.1% and 89.5% respectively. In 42 cases (62.7%) KS was the initial AIDS presentation. The most common localization was the skin (89.5%), followed by the digestive tract (52.2%) and the lymph nodes (22.4%). Staging distribution was: 20 patients (29.8%) were in stage I, 11 patients (16.4%) in stage II, 7 patients (10.4%) in stage III, and 29 patients (43.2%) in stage IV. Constitutional symptoms associated to KS were found in 37 patients (55%). Overall 39 patients have already died, and the actuarial survival possibility of these 67 cases was 55% after 12 months. Univariant statistical analysis showed the presence of six variables with prognostic significance (p less than 0.05): staging, symptomatology, total white blood count, total lymphocyte count, T helper lymphocyte count and hemoglobin. Multivariant statistical analysis only chose the staging and symptomatology variables as independent (p less than 0.01 and p less than 0.001, respectively).

Acquired Immunodeficiency Syndrome↗

Subacute cutaneous lupus erythematosus: clinicopathologic findings in thirteen cases.

The clinicopathologic and serologic findings of thirteen patients with subacute cutaneous lupus erythematosus are reported. The clinical and immunologic features are similar to those described by most other authors. From a histologic point of view, however, two aspects could be emphasized: the presence of a larger number of epidermal colloid bodies and severe epidermal necrosis (more than 60% of cases). All patients with this microscopic picture have a similar clinical and serologic pattern: annular lesions, anti-Ro antibodies and human leukocyte antigen-DR3.

Adult↗

[The concept of cryptic cutaneous atopy in contact reactions. Considerations on the clinical control over the subgroup of patients with frustrated cutaneous atopy].

Contact dermatitis, allergic or irritative, is not distributed by chance among the general population, but appears in a determined group of patients. The clinical and anamnestic picture of this group of patients (and that of their close blood relatives) is described. Clinical facts lead us to consider that group of patients as a subgroup of cutaneous atopy. The medical-legal importance which the acceptance of this type of patient could have on occupational contact dermatitis is pointed out. In contact dermatitis the factors of the person suffering the contact rather than those of the contact agents seem to be of decisive power in the response, although at the present moment, the possibility of carrying out analytical studies on the allergens and irritants is easier than on the patients who react to them.

Dermatitis, Atopic↗