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Biomedical subjects

J M Mascaro

Publications and source records attributed to J M Mascaro.

At least 37 records · Page 2Linked to original sources
PubMed1997

Mucosal and mucocutaneous (generalized) pemphigus vulgaris show distinct autoantibody profiles.

Pemphigus vulgaris is an autoimmune bullous disorder characterized by autoantibodies directed against desmoglein 3. A group of 19 pemphigus vulgaris sera were characterized by immunoblotting, immunofluorescence, immunoprecipitation, and the passive transfer mouse model. The aim of these studies was to determine the specificity of the autoantibody response in these patients. All patients had clinical and histologic evidence of pemphigus vulgaris. Fogo selvagem sera (n = 8), bullous pemphigoid sera (n = 8), antinuclear antibodies positive sera from patients with lupus erythematosus (n = 2), and normal human sera (n = 8) were used as controls. All pemphigus vulgaris patients showed titers of IgG autoantibodies by indirect immunofluorescence > or = 1:60, predominantly of the IgG4 subclass and immunoprecipitated recombinant desmoglein 3 expressed in the baculovirus system. Patients with disease localized to the mucous membranes showed no reactivity with desmoglein 1 and only one had weak reactivity with mouse skin by indirect immunofluorescence (titer = 1:20). Sera of four of these mucosal patients were tested in the mouse model and three of four did not elicit skin or mucosal disease in the animals. In contrast, sera from all seven patients with disease involving the skin and mucous membranes (generalized disease) produced disease in neonatal mice. In one patient the disease evolved from pure mucosal involvement associated with anti-desmoglein 3 antibodies to a disorder involving mucosas and skin. This transition was associated with the appearance of anti-desmoglein 1 antibodies in the patient's serum. These studies indicate that the autoantibody response in pemphigus vulgaris is heterogeneous. Epitopes recognized by some pemphigus vulgaris sera are species specific and others may be mucosal specific.

Animals↗
PubMed1997

A highly sensitive enzyme-linked immunosorbent assay for the detection of circulating anti-BP180 autoantibodies in patients with bullous pemphigoid.

The BP180 antigen, a component of the epidermal anchoring complex, has been identified as one of the major antigenic targets of autoantibodies associated with the blistering skin disease, bullous pemphigoid. Our research group has recently demonstrated that reactivity of bullous pemphigoid autoantibodies to the BP180 ectodomain is almost entirely restricted to a set of four antigenic sites clustered within the membrane-proximal noncollagenous stretch (NC16A). Using a passive transfer mouse model, antibodies to the corresponding noncollagenous region of murine BP180 were shown to trigger an inflammatory subepidermal blistering disease that closely mimics bullous pemphigoid. We now report the development of an enzyme-linked immunoabsorbent assay system that is extremely sensitive in detecting disease-specific autoantibodies in the sera of bullous pemphigoid patients. The target antigen in this assay is a recombinant form of the BP180 NC16A domain that contains all four of the well-defined bullous pemphigoid-associated antigenic sites. Of 50 randomly selected bullous pemphigoid sera tested, 47 (94%) were positive in this assay, whereas no specific reactivity was detected in any of the 107 controls. Interestingly, all three of the bullous pemphigoid sera that were negative in this assay had been obtained from patients who were already undergoing treatment. The NC16A enzyme-linked immunosorbent assay is more sensitive than any of the standard techniques for detecting circulating bullous pemphigoid autoantibodies, including other enzyme-linked immunosorbent assays, immunoblotting, and indirect immunofluorescence. Finally, the NC16A enzyme-linked immunosorbent assay provides immunologic information that cannot be obtained from direct immunofluorescence studies of skin biopsies, and that may well be relevant in the diagnosis and treatment of bullous pemphigoid.

Autoantibodies↗
PubMed1997

Uncommon cutaneous manifestations of lupus erythematosus.

Cutaneous manifestations of lupus erythematosus (LE) are, usually, characteristic enough to permit an easy diagnosis. However, some patients may present less typical lesions, associated or not to the classic ones. Therefore, irrespectively of the variety of LE (acute, subacute and chronic), in absence of the typical butterfly rash, erythematosquamous papules or plaques, or any of the characteristic cutaneous alterations, it is important (even though not always easy) to recognize the uncommon and/or atypical changes of the skin.

Chilblains↗
PubMed1995

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↗
PubMed1995

The porphyrias: a brief overview based on 25 years of experience (1969-1994) by the Department of Dermatology of the Hospital Clinic and Faculty of Medicine of Barcelona, Spain.

The porphyrias are uncommon diseases caused by enzymatic deficiencies in the heme pathway. In the 25 year period 1969-1994, the Department of Dermatology of the Hospital Clinic of Barcelona has been able to study 793 cases of porphyria (724 cases of PCT, 27 of EPP, 26 of PV, 5 of CEP, 5 of HEP, 5 of AIP, 1 of HCP). Homozygous expression of an enzymatic deficiency in the heme pathway produces severe disease. Commonly, clinical manifestations appear in the homozygous state (the autosomal recessive porphyrias). However, homozygous forms of autosomal dominant porphyrias may occur exceptionally. Moreover, there are cutaneous porphyrias whose clinical manifestations do not permit dermatologists to classify them clearly into one of the well-defined syndromes. These uncommon and atypical forms are difficult to recognize without biochemical and enzyme studies. The porphyrias have a wide clinico-biochemical spectrum, including a large proportion of well defined diseases. Nevertheless, atypical forms occur and may be difficult to evaluate. It is important to note the genetic heterogeneicity of porphyrias, which accounts for the varying phenotypic expression.

Hospital Departments↗
PubMed1995

Chromosome 9p deletions in cutaneous malignant melanoma tumors: the minimal deleted region involves markers outside the p16 (CDKN2) gene.

We have analyzed 12 microsatellite markers on chromosome 9p in 54 paired cutaneous malignant melanoma (CMM) tumors and normal tissues. Forty-six percent of the tumors, including two in situ CMMs, showed loss of heterozygosity (LOH) at 9p. Only one tumor was homozygously deleted for 9p markers. The smallest deleted region was defined by five tumors and included markers D9S126 to D9S259. Loss of eight or more markers correlated significantly with worse prognosis (P < .002). Among the primary tumors, 87.5% of those with large deletions have a high risk of metastasis, as compared with only 18% of those without deletions or with loss of fewer than 8 markers (P < .001). It was not possible to demonstrate homozygous deletions of p16 in any of the CMM tumors. In four tumors, the LOH for 9p markers did not involve p16. The reported data suggest the existence of several tumor suppressor genes at 9p that are involved in the predisposition to and/or progression of CMM and exclude p16 from involvement in the early development of some melanoma tumors.

Base Sequence↗
PubMed1995

The porphyrias and hepatocellular carcinoma.

Hepatocellular carcinoma probably represents the final step of the effects of the various precipitating agents for porphyria cutanea tarda, such as alcohol, drugs, hormones, and hepatitis C infection. Risk factors associated with its development include male gender, age over 50 years, liver fibrosis or cirrhosis, and a long history (over 10 years) of symptomatic porphyria cutanea tarda.

Adult↗
PubMed1995

[Midazolam versus placebo before spinal anesthesia].

The goal of this randomized, double blind and multicentric study was to compare the effects of midazolam (M) and placebo (P) administered by titration before puncture for spinal anaesthesia on the comfort of 211 patients scheduled for elective surgery after oral premedication with hydroxyzine. The administered dose of midazolam was 3.4 +/- 1.3 mg (mean +/- SD). Anxiety was nil in 92% of the patients of the M group and in 64% of the patients of the P group (p < 0.001) and memorization of the pain of the puncture was reported in 34% of the patients of the M group and in 66% of the patients of the P group (p < 0.001). However cooperation of the patient and easiness of the puncture were similar in both groups. In conclusion titrated sedation with midazolam before puncture for spinal anaesthesia increases the comfort of the patient.

Adjuvants, Anesthesia↗
PubMed1994

The porphyrias.

Explore the source record for details and available documents.

Humans↗
PubMed1992

Specific cutaneous lesions in a CD8+ peripheral T-cell lymphoma.

Histopathologic, immunohistochemical, and ultrastructural studies were carried out on cutaneous lesions of a 43-year-old man with an aggressive peripheral T-cell lymphoma involving the lung, central nervous system, bone marrow, and skin. Some results are distinctive and not previously reported, such as extremely strong epidermotropism, aberrant CD8+ immunophenotype with lack of one pan T antigen (CD5), and giant cytoplasmic granules. We discuss these features comparing them with other hematologic malignancies usually involving the skin, such as cutaneous T-cell lymphoma, adult T-cell leukemia/lymphoma, angiocentric lymphomas, and malignant histiocytosis.

Adult↗
PubMed1992

Neutrophilic pustulosis associated with chronic myeloid leukemia: a special form of Sweet's syndrome. Report of two cases.

Two subjects with Ph-positive chronic myeloid leukemia (CML) in whom pustular Sweet's syndrome was diagnosed are reported. The first patient was a 47-year-old woman who developed fever, painful ulcers of the oral mucosa and vagina and generalized pustulous skin lesions 2 years after the diagnosis of CML. Histologically, the skin lesions consisted of dense neutrophilic infiltrates with perifollicular disposition. The microbiologic studies were negative. The lesions showed a favorable response to corticosteroids, but fever recurred with every attempt of tapering prednisone; it finally disappeared with the addition of oral cyclophosphamide. The second patient was a 45-year-old man who developed fever and disseminated pustules with histologic features consistent with Sweet's syndrome and negative microbiologic studies at 2.5 years after diagnosis of CML. The picture showed a dramatic response to prednisone and did not recur after the drug was discontinued. In both patients, CML remained stable after resolution of Sweet's syndrome.

Cyclophosphamide↗