RESUMEN

Two-thirds of Earth's surface is formed at mid-ocean ridges, yet sea-floor spreading events are poorly understood because they occur far beneath the ocean surface. At 9 degrees 50'N on the East Pacific Rise, ocean-bottom seismometers recently recorded the microearthquake character of a mid-ocean ridge eruption, including precursory activity. A gradual ramp-up in activity rates since seismic monitoring began at this site in October 2003 suggests that eruptions may be forecast in the fast-spreading environment. The pattern culminates in an intense but brief (approximately 6-hour) inferred diking event on 22 January 2006, followed by rapid tapering to markedly decreased levels of seismicity.

Asunto(s)

Asunto(s)

RESUMEN

Abnormal expression of class II MHC antigens was consistently observed in an immunohistological study on placentae from patients with pemphigoid gestationis. The area affected in all the placentae was the chorionic villi adjacent to the maternal decidua. The villous stroma, and in some cases the chorionic fetal endothelium, had abnormal expression of class II MHC antigens. Monoclonal antibodies specific for the class II MHC subregion products (DR, DP and DQ) were used to analyse the class II MHC antigen expression. Differential expression of the class II MHC subregion products was observed on the villous stroma and chorionic fetal endothelium; DR and DP were always expressed but DQ in some cases was heterogeneous. This abnormal expression of class II MHC antigens may reflect an immunological attack on the placenta in pemphigoid gestationis.

Asunto(s)

Asunto(s)

RESUMEN

The villous stroma and fetal endothelium in chorionic villi adjacent to maternal decidua in a placenta of a woman suffering from pemphigoid gestationis were found to have abnormal expression of HLA-DR antigen. This aberrant DR expression may be a reflection of an immune attack on the placenta.

Asunto(s)

Asunto(s)

RESUMEN

A 34-year-old man is described with angiokeratoma corporis diffusum. This eruption was once thought to be diagnostic of Anderson-Fabry disease; however, recent studies have shown that it may also occur in the enzyme disorders fucosidosis and sialidosis. In our patient with widespread angiokeratomas, the results of enzyme studies were normal, and there were no systemic problems or significant family history. Our case demonstrates that angiokeratoma corporis diffusum can occur in a benign form without systemic features.

Asunto(s)

Asunto(s)

RESUMEN

We have studied the infants in fifty pregnancies affected by pemphigoid gestationis (herpes gestationis). There was a significant increase in the frequency of infants that were 'small for dates'. As such infants have a raised mortality and morbidity it follows that in pemphigoid gestationis the fetal prognosis is impaired. In view of this it is essential that patients with pemphigoid gestationis are delivered in maternity units which have facilities for intensive care of the newborn.

Asunto(s)

RESUMEN

Circulating immune complexes were measured in 35 patients with polymorphic eruption of pregnancy employing three different techniques. No significant abnormalities were detected by the C1q solid phase binding assay and polyethylene glycol precipitation of immunoglobulin G. However, using a solid phase polyclonal rheumatoid factor binding assay, which detects small immune complexes, we demonstrated a significant reduction in the level of circulating immune complexes during the acute stage of the eruption. We suggest that the leakage of small immune complexes through dilated upper dermal vessels may play a role in the aetiology of polymorphic eruption of pregnancy.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

In a study of twenty-five patients with herpes gestationis we found that 80% possessed the HLA antigen DR3, which confers increased immune responsiveness and a predisposition to 'auto-immune disease'. In five patients the development of herpes gestationis coincided with a change in sexual partner, suggesting that the development of herpes gestationis may depend on exposure to an antigen derived from the father. This might share determinants with a component of the basement membrane zone of skin. Although anti-basement membrane zone antibodies are present in HG it is not clear whether they play a pathogenic role. The infrequency of neonatal involvement and the lack of correlation between immunofluorescence findings and clinical activity in our patients suggested that the antibodies might be a result of tissue damage rather than its cause. Two patients in our study were exceptional in that episodes of herpes gestationis were followed by normal pregnancies. In these patients the relationship of their DR antigens to those of the fetus may have been important in determining whether or not the pregnancy would be affected by herpes gestationis.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

The terminology of the specific dermatoses of pregnancy has become increasingly confusing, with several names in use for identical clinical disorders. On the basis of our own study of sixty-four patients and a review of the literature, we propose a simplified classification: (1) herpes gestationis (pemphigoid gestationis); (2) polymorphic eruption of pregnancy; (3) prurigo of pregnancy; and (4) pruritic folliculitis of pregnancy.

Asunto(s)

RESUMEN

Five patients with typical bullous herpes gestationis and five patients with polymorphic eruption of pregnancy were studied. Shave biopsies were taken from both involved and uninvolved skin and examined by routine immunofluorescence. They were also examined by immunoelectron microscopy employing a multistep peroxidase-antiperoxidase technique which has been shown to be more sensitive than immunofluorescence. Despite the increased sensitivity of immunoelectron microscopy all cases of polymorphic eruption of pregnancy were completely negative. Although there is a considerable clinical and histopathological overlap between herpes gestationis and polymorphic eruption of pregnancy our findings indicate that these conditions are pathogenetically distinct and should be classified as separate disorders.

Asunto(s)

RESUMEN

We compared the clinical features, histopathology, immunopathology and immunogenetics of 30 patients with toxic erythema of pregnancy and 24 patients with herpes gestationis. Although we found some clinical and histopathological overlap we highlighted several important differences. In toxic erythema of pregnancy prominent striae were frequently present. Herpes gestationis was suggested by the occurrence of periumbilical lesions, acute exacerbations immediately after delivery, and persistence of the eruption for more than 3 weeks post-partum. In herpes gestationis, immunofluorescence studies were consistently positive, there was a high frequency of HLA-B8 and an association with autoimmune thyrotoxicosis. Toxic erythema of pregnancy did not share these immunological features. Therefore we feel that toxic erythema of pregnancy and herpes gestationis should continue to be classified as separate disorders.

Asunto(s)

Asunto(s)