The following hypotheses were tested for groups of simultaneous hermaphrodites Biomphalaria tenagophila: (a) snails that have low reproductive success during the process of self-fertilization do not increase their reproductive success after the end of grouping; (b) the copulation behaviour and the presence of one snail whose eggs have a low viability rate influence the partner's reproductive su...

Patterning of the bipotential retinal primordia (the optic vesicles) into neural retina and retinal pigmented epithelium depends on its interaction with overlaying surface ectoderm. The surface ectoderm expresses FGFs and the optic vesicles express FGF receptors. Previous FGF-expression data and in vitro analyses support the hypothesis that FGF signaling plays a significant role in patterning t...

PCSCC is a variant of invasive squamous cell carcinoma, with less than 20 cases reported, to our knowledge, in the English literature [1,2]. PCSCC had been more often reported to occur in the oral mucosa and conjunctiva [3]. Pigmentation is probably due to cytokines secreted by tumoral cells that stimulate melanocytes to produce melanin [4]. In some cases, PCSCC may be the malignant progression...

BACKGROUND It is unclear whether pigmented Spitz and Reed nevi are distinct morphologic entities or part of the spectrum of Spitz nevi. METHODS In a retrospective observational study we analyzed dermatopathologic slides of 22 cases with clinical and dermatoscopic features indicative of pigmented Spitz or Reed nevus in a blinded fashion according to predefined criteria and subsequently correla...

BACKGROUND The absence or deficiency of melanin as in albinos, has detrimental effects on retinal development that include aberrant axonal projections from eye to brain and impaired vision. In pigmented retinal pigment epithelium (RPE), dihydroxyphenalanine (L-Dopa), an intermediate in the synthetic path for melanin, has been hypothesized to regulate the tempo of neurogenesis. The time course o...

Vitiligo is a disorder causing skin depigmentation, in which several factors have been proposed for its pathogenesis: Environmental, genetic and biological aspects of melanocytes, even those of the surrounding keratinocytes. However, the lack of understanding of the mechanisms has complicated the task of predicting the development and progression. The present study used microarray analysis to c...

IMPORTANCE Dermoscopic triage algorithms have been shown to improve beginners' abilities for identifying pigmented skin lesions requiring biopsy. OBJECTIVE To estimate the diagnostic accuracy of the Triage Amalgamated Dermoscopic Algorithm (TADA) for pigmented and nonpigmented skin cancers. Secondarily, to compare TADAs performance to those of existing triage algorithms for the identification...

PURPOSE The inheritance of specific apolipoprotein E allelles has been linked to atherosclerosis, Alzheimer disease, and, most recently, to the incidence of age-related macular degeneration. Apolipoprotein E is a common component of the extracellular plaques and deposits characteristic of these disorders, including drusen, which are a hallmark of age-related macular degeneration. Accordingly, w...

purpose: to report a rare case of ciliochoroidal malignant melanoma presenting as a subconjunctival black-colored mass adjacent to the limbus. patient and findings: a 42-year-old woman presented with a subconjunctival black-colored mass adjacent to the limbus in left eye from 2 years ago. the lesion had increased in size during the previous 2 months. funduscopic examination with scleral depress...

A 23-year-old man had a lesion in the right inferior iris which appeared to have enlarged since it was first seen when the patient was aged 5 years. The lesion was excised by a partial iridocyclectomy. Histopathologically the neoplasm was composed of both pigmented and non-pigmented cells. Pseudoacini, containing acid mucopolysaccharides, were present throughout the tumour matrix. Electron micr...