Enfermedad de Paget extramamaria / Extramammary Paget's disease

La enfermedad de Paget extramamaria es un carcinoma epidérmico de diferenciación apocrina que se origina en la epidermis o secundario a la diseminación epidermotropa de neoplasias adyacentes o a distancia. Suele presentarse como una lesión eccematiforme, de límites bien definidos, en zonas ricas en glándulas apocrinas como axilas, zona genital y anal. Su pronóstico depende de 2 factores: la profundidad de la invasión del tumor primario y de la presencia o no de tumor asociado. Su sintomatología inespecífica y la lenta evolución de las lesiones a menudo provoca un retraso en el diagnóstico que conlleva un empeoramiento del pronóstico. El diagnóstico de enfermedad de Paget es histológico precisando en ocasiones un estudio inmunohistoquímico. La inmunohistoquímica permite orientar hacia la naturaleza primaria o secundaria de la enfermedad, pero precisará de un estudio de extensión (AU)

Extramammary Paget disease is an epidermal carcinoma with apocrine differentiation originating in the epidermis o secondary to epidermotropic dissemination from a near or distant neoplasm. It usually shows as an eczematiform lesion with well defined margins in areas rich in apocrine glands, such as the axilla, genital and anal areas. Prognosis is defined by two factors: depth of invasion of primary tumour and whether there is an associated tumour. Its non specific clinical signs and slow evolution of the lesions, often delay the diagnosis, which leads to a poor prognosis. The diagnosis of Paget's disease is histological, sometimes requiring an immunohistochemical study. This can orient towards the primary or secondary nature of the disease, but will still need an extension study (AU)

Study of the microbial aggregation in Mycobacterium using image analysis and electron microscopy.

Cellular aggregation, which occurs in both prokaryotes and eukaryotes, is controlled by the hydrophobicity as well as the electrokinetic potential of the cell surface and substratum. It is known that the Mycobacterium genus form aggregates, but the influence of sugar on the cellular aggregation has not been reported for this genus. The mutant strain Mycobacterium sp. MB-3683 that transforms sterol to androstenedione (AD), a steroidal precursor used by the pharmaceutical industries, was employed in this study. This strain was cultivated in a synthetic medium on three sugars (glycerol, glucose and fructose) at different concentrations, and at 144 h microbial growth, cellular aggregation, hydrophobicity, lipid content, fatty acid composition, and width of cellular walls were measured. It was observed that at different sugar concentrations, similar growth and pH were obtained. However, in fructose, the aggregation level was significantly high, followed by glycerol and glucose (fructose < glycerol < glucose). These results were confirmed using electron microscopy and the aggregate area quantified by image analysis. Hydrophobicity was the highest in fructose and the lowest in glucose. The total lipids, in contrast to cellular hydrophobicity, were higher in glucose than glycerol. Although, the hydrophilic-lipophilic balance (HLB) of principal fatty acids isolated was similar regardless of sugar used. In glycerol and fructose, the paraffins were observed, which are responsible for the high cellular hydrophobicity detected above. The width of cell wall of the organisms grown on glucose and fructose was similar, but in glycerol the walls were very thin. There is a correspondence between cell wall width and lipid content.

Effects of cytochalasin B and of deoxyglucose on phagocytosis-related changes in membrane potential in rat peritoneal macrophages.

Cytochalasin B (CB) and deoxyglucose alter the electrical responses of the plasma membrane of rat peritoneal macrophages to the presence of phagocytosable latex particles. With both agents, instead of the initial hyperpolarization we previously observed, there is a depolarization. In the case of cytochalasin B (CB) this is followed by a gradual repolarization to the initial resting level, whereas with deoxyglucose the membrane eventually does hyperpolarize. One possible interpretation is that plasma membrane receptors mediate the depolarization in response to phagocytosable particles, but that normally this is masked by other changes effected here by the agents we used.

Hyperpolarisation of rat peritoneal macrophages phagocytosing latex particles.

The changes that take place in the plasma membrane during endocytosis are still poorly understood. Studies of the electrical properties and related permeabilities of cells during pinocytosis and phagocytosis should provide insight into these changes. This approach has not been much exploited, although there have been a few relevant reports. For example, induction of pinocytosis in amoebae produces a marked decrease in plasma membrane resistance, and exposure of polymorphonuclear leukocytes to phagocytosable particles can engender alterations in ionic permeabilities. The present report demonstrates that the induction of phagocytosis in rat peritoneal macrophages is accompanied by a sustained hyperpolarisation of the cells.