Dermal dendrocytes are decreased in collagenomas.

Dermal dendrocytes comprise a subset of spindle-shaped cells which normally reside in the dermis. While they appear to play some role in the reticuloendothelial system, their exact functions have not been completely elucidated. In addition to their purported immunologic functions, it has been suggested that dermal dendrocytes may play an inhibitory role in the regulation of dermal collagen synthesis. We examined 7 collagenomas with antibodies directed against factor XIIIa (FXIIIa) in order to test the hypothesis that dermal dendrocytes were focally diminished in these hamartomatous overgrowths of collagen. In all cases, there was a marked diminution in the number of FXIIIa-positive cells in the lesional dermis when compared to the surrounding dermis. Our data support the hypothesis that dermal dendrocytes may be involved in regulation of collagen synthesis.

Alopecia universalis in an HIV-positive patient: possible insight into pathogenesis.

Alopecia universalis, a variant of alopecia areata, is a disease of unknown etiology, though evidence for an autoimmune etiology continues to mount. We report an HIV-positive patient with altered T-lymphocyte subsets in whom alopecia universalis developed. A skin biopsy of the patient's scalp demonstrated a classic perifollicular lymphocytic infiltrate, and immunophenotyping of the same specimen revealed that the majority of the cells were CD4+ lymphocytes. During the active loss of hair, the patient's CD4/CD8 ratio was decreased. This ratio normalized during the period of regrowth. Our data suggest that systemic immune dysfunction, as seen in HIV infection, may be more important in mediating alopecia areata than localized immune responses. Given the proposed mechanism of alopecia areata developing in this patient, i.e. influx of CD4+ lymphocytes to the perifollicular regions of skin when the CD4/CD8 ratio is low, it is surprising that alopecia areata is not seen more commonly in patients with HIV infection.

The role of categorization in visual search for orientation.

Visual search for 1 target orientation is fast and virtually independent of set size if all of the distractors are of a single, different orientation. However, in the presence of distractors of several orientations, search can become inefficient and strongly dependent on set size (Exp. 1). Search can be inefficient even if only 2 distractor orientations are used and even if those orientations are quite remote from the target orientation (e.g. 20 degrees or even 40 degrees away, Exp. 2). Search for 1 orientation among heterogeneous distractor orientations becomes more efficient if the target orientation is the only item possessing a categorical attribute such as steep, shallow (Exp. 3), tilted left or tilted right (Exp. 4), or simply tilted (Exps. 5 and 6). Orientation categories appear to be 1 of several strategies used in visual search for orientation. These serve as a compromise between the limits on parallel visual processing and the demands of a complex visual world.

Epidermolysis bullosa acquisita (EBA) and esophageal webs: a new association.

Epidermolysis bullosa acquisita (EBA) is a well-defined, blistering disorder of the skin associated with autoantibodies to type VII collagen. Although esophageal pathology is common in children with hereditary dystrophic forms of epidermolysis bullosa, esophageal problems have not been reported previously in patients with bona fide EBA. In this report, a 71-yr-old white female with longstanding EBA presented with recurrent dysphagia and multiple esophageal webs that responded to esophageal dilatation.

Epidermolysis bullosa acquisita and associated symptomatic esophageal webs.

Epidermolysis bullosa acquisita (EBA) is a well-characterized, subepidermal blistering disorder associated with autoimmunity to type VII collagen, which is the collagen localized to anchoring fibrils within the dermoepidermal junction of skin. Although the full clinical spectrum of EBA is still being defined, it is known that the clinical features of EBA may be reminiscent of hereditary dystrophic epidermolysis bullosa, a scarring blistering disease of children that is commonly associated with esophageal stenosis. We describe a patient with EBA who had both an acral-predominant mechanobullous disease akin to dystrophic epidermolysis bullosa and an inflammatory, widespread bullous eruption reminiscent of bullous pemphigoid in association with esophageal webs and dysphagia. Although esophageal involvement is common in dystrophic epidermolysis bullosa, a review of the literature shows that this is the first bonafide case of EBA with symptomatic esophageal disease.

Marketing, financial goals play into CCRC refund plan.

An entry fee refund is the marketing tool for continuing care retirement communities (CCRCs) with the most easily assessed financial effects. The financial results of refund schedules can be measured in terms of a CCRC's ability to generate pools of cash and withdraw cash from these pools to fund operations. A CCRC's choice of refund schedule also will affect net present value of an investment in retirement housing.

Limitations on the parallel guidance of visual search: color x color and orientation x orientation conjunctions.

In visual search for a conjunction it is much more difficult to search for the conjunction of 2 colors or 2 orientations than for Color x Orientation or Color x Shape conjunctions. The result is not limited to particular colors or shapes. Two colors cannot occupy the same spatial location in Color x Color searches. However, Experiments 6 and 7 show that Color x Shape searches remain efficient even if the color and shape are spatially separated. Our guided search model suggests that in searches for Color x Shape, a parallel color module can guide attention toward the correct color, whereas the shape module guides attention toward the correct shape. Together these 2 sources of guidance lead attention to the target. However, if a target is red and green among red-blue and green-blue distractors, it is not possible to guide search independently toward red items and green items or away from all blue items.

Conflict and the friendship relations of young children.

The purpose of this investigation was to compare conflicts occurring between young children and their friends to those occurring between nonfriends. 53 children with a median age of 4 years, 3 months were observed and interviewed to determine who were mutual friends, unilateral associates, or neutral associates. 146 conflicts were also observed. Conflicts between mutual friends, as compared to those occurring between neutral associates: (a) did not occur less frequently, differ in length, or differ in the situations that instigated them, but (b) were less intense, were resolved more frequently with disengagement, and more frequently resulted in equal or partially equal outcomes. Continued socialization was also more likely following conflicts between friends. Conflicts between unilateral associates resembled those between nonfriends, although postconflict interaction resembled that between mutual friends. Conflict resolution strategies favored by friends maximize the likelihood that their interaction and their relationships will continue.

Molecular cloning and expression of the major protein kinase C substrate of platelets.

In platelets, agonists that stimulate phosphoinositide turnover cause the rapid phosphorylation of a protein of apparent relative molecular mass (Mr) 40-47,000, called P47, by protein kinase C (PKC). Diverse identities have been ascribed to P47 including lipocortin, inositol 1,4,5-trisphosphate 5-phosphomonoesterase, pyruvate dehydrogenase alpha subunit and an actin regulatory protein. We have isolated human P47 clones by immunological screening of a lambda gt11 complementary DNA library from HL-60 cells, a human promyelocytic leukaemia cell line. P47 recombinants thus identified hybridized to a 3.0 kilobase (kb) messenger RNA in mature white blood cell lines; the same mRNA was induced in HL-60 cells during differentiation. A 1,050 base pair (bp) open reading frame that could encode a protein of Mr40,087 was confirmed by comparison with peptide sequences from platelet P47, and by expression of the putative recombinant P47 in E. coli and in vitro. The P47 sequence appears to have been conserved throughout vertebrate evolution, and is not similar to any other known sequence including human lipocortin and the alpha subunit of pyruvate dehydrogenase. The P47 protein contains a potential Ca2+-binding 'EF-hand' structure and a region that strongly resembles known PKC phosphorylation sites.