Ultrastructural findings in progressive macular hypomelanosis indicate decreased melanin production.

Background: The pathogenesis of progressive macular hypomelanosis (PMH) is unknown. Recently, Westerhof et al. (Arch Dermatol 2004; 140: 210-214) hypothesized that Propionibacterium acnes produces a depigmenting factor that interferes with melanogenesis in the skin, resulting in hypopigmented spots.

Ultrastructural pathology of aortic dissections in patients with Marfan syndrome: Comparison with dissections in patients without Marfan syndrome.

Despite the discovery in 1990 that mutations in the fibrillin-1 gene cause the Marfan syndrome, the pathogenesis of the life-threatening dissections associated with this disease is far from elucidated. Both the massive number of known fibrillin-1 mutations that result in a heterogeneous patient population and the strongly heterogeneous histology of patients' aortae presumably contribute to this lack of knowledge. We performed a detailed ultrastructural immunoelectron microscopic and histochemical analysis of the dissected media of ascending aortae of 10 patients with Marfan syndrome and compared them with those of 6 patients without Marfan syndrome and 77 individuals without known aortic disease.

Hepatic response to right ventricular pressure overload.

Background & Aims: Modifying the afferent blood supply to the liver does not change the zonal expression pattern of hepatic enzymes in the rat.

Methods: We used pulmonary trunk banding (PTB) to study the effect of an efferent hindrance of blood flow on hepatic architecture and zonation of gene expression.

Results: Most PTB rats developed right ventricular hypertrophy and congestive heart failure.

Hypermelanocytic guttate and macular segmental hypomelanosis.

We report two sisters, 27 and 30 years of age, with a cutaneous pigmentary anomaly, which seems to be a new entity. At the age of 26 years the elder sister developed an asymptomatic and persistent rash consisting of discrete, grouped, round to oval, guttate and nummular, hypopigmented macules, 0.2-5 cm in diameter.

Generalized mottled pigmentation with postnatal skin blistering in three generations.

We describe three generations of a family expressing progressive mottled hypopigmentation and hyperpigmentation on the non-exposed parts of the body from childhood to adult life. At birth, they all had epidermal blistering of the distal extremities. Although the palmoplantar warty keratoses could be related to the bulla formation, the pigmentary changes could not.