Multi-scale distribution and dynamics of bivalve larvae in a deep atoll lagoon (Ahe, French Polynesia).

Bivalve larvae and hydrographic parameters were sampled over a range of spatio-temporal scales in a deep atoll lagoon. Bivalve larvae abundances were very high throughout the year: 18,550 m(-3) in average. Larvae were (i) concentrated at mid-depth with nocturnal ascent and diurnal descent, (ii) heterogeneously dispersed at the lagoon scale, (iii) subject to day-to-day variation in abundance and (iv) transferred between different parts of the lagoon providing evidence of intra-lagoonal connectivity. The primacy of physical factors was seen on large spatial scale with the diluting effect of water renewal and transfers by hydrodynamics. On smaller spatial scale, the primacy of biological processes was recognised, with larval swimming activity leading to dial vertical migration correlated with food concentration. Variations in larval abundance were driven by bivalve reproductive activity correlated with meteorological conditions (i.e. windy periods). Finally, relationship between bivalve larvae patterns and pearl oyster (Pinctada margaritifera) settlement structuring is discussed.

Bivalve larvae transport and connectivity within the Ahe atoll lagoon (Tuamotu Archipelago), with application to pearl oyster aquaculture management.

Patterns of bivalve larvae dispersal in the deep Ahe atoll lagoon was studied by using a numerical 3D transport model (MARS3D) coupled with a vertical swimming sub-model, forced mainly by tide and wind-induced currents. The simulations were validated against observations of larval dispersal monitored several days throughout the lagoon. Connectivity matrices describing larval exchanges inside the lagoon were inferred. Larvae displayed a significant dispersal capacity at the lagoon scale, especially with dominant eastern winds. With southeastern winds, larvae mostly remained in their origin sector. The total export rate of the larvae, toward the ocean through the pass and shallow lagoon borders, was independent of the wind conditions, with 1% of the total concentration exported per day. However, the tide-driven currents efficiently flushed larvae in sectors close to the pass. Connectivity matrices suggest that the south and west sectors were more suitable for spat collecting and that central sectors would be efficient sanctuaries if genitors were accumulated.

Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.

A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies elsewhere and we provide guidelines in terms of costs for all the different stages involved.

Human eastern equine encephalitis: immunohistochemistry and ultrastructure.

The brain of a 7-year-old boy who died of eastern equine encephalitis (EEE) was examined by immunohistochemical and ultrastructural techniques to detect the presence and distribution of viral antigen. A mouse polyclonal antibody was most effective for demonstrating the presence of antigen previously unreported in this disease in humans. Antigen was localized to the perikaryon and dendrites of neurons; little was detected in glial cells. Cell death by apoptosis was conspicuous, but it was primarily identified in glial and inflammatory cells. Neuronal death was most commonly marked by cytoplasmic swelling or eosinophilia and nuclear pyknosis. A disassociation between the degree of inflammation and the presence of antigen was noted, especially in cerebral cortex and spinal cord, presumably where infected cells already had been cleared. Ultrastructurally, rare mature viral particles were seen in extracellular spaces.

Musculoaponeurotic fibromatosis (extraabdominal desmoid tumor) in a child with idiopathic multicentric osteolysis.

The fibromatoses are a group of benign proliferations of fibrous tissue with clinical behavior ranging from that of truly malignant tumors to that of benign reactive fibrous proliferations. Some of the superficial fibromatoses are fairly common, but the deep ones, also known as desmoid tumors or musculoaponeurotic fibromatoses, are rare. Idiopathic multicentric osteolysis is a rare skeletal disorder of childhood that causes progressive destruction of bones and renal failure. We recently saw a young girl with both extraabdominal musculoaponeurotic fibromatosis and idiopathic multicentric osteolysis. The classification, diagnosis, and treatment of the deep fibromatoses are reviewed, and the possible association between the minor bone changes occasionally reported in musculoaponeurotic fibromatosis and idiopathic multicentric osteolysis is discussed.

Endoscopic treatment of reflux: migration of Teflon to the lungs and brain.

We set out to determine experimentally whether particles of polytetrafluoroethylene migrate to the lungs and brain when relatively small volumes of Teflon paste are injected into the bladder in the manner used to correct reflux. Numerous particles of polytetrafluoroethylene were recovered from these organs within 2 weeks of injection. Those in the brain measured up to 15 microns in diameter, indicating that the pulmonary bed is an inefficient filter of particles gaining access to the venous circulation. Although clinically no adverse neurological effects have hitherto been reported, this study suggests that following the 'sting' procedure, some particles may lodge in the brain where they can block the cerebral microcirculation. We believe these findings represent a contraindication to the use of Teflon paste in children.

Demonstration of silicon in sites of connective-tissue disease in patients with silicone-gel breast implants.

BACKGROUND AND DESIGN: Silica, Silastic, and silicone (any organic compound in which silicon replaces carbon) have been associated with a number of connective-tissue diseases, most commonly systemic sclerosis (scleroderma). Silicone is known to leak from breast implants and spread to surrounding tissues, including lymph nodes, but silicone's role in the origin and pathogenesis of the inflammation and fibrosis related to such conditions remains controversial. Synovial tissue, alveolar macrophages, and skin, each from three different patients with silicone-gel implants, plus the breast implant capsules from each of the three patients, were examined by light microscopy, transmission electron microscopy, and electron probe microanalysis for the presence of silicon-containing material. RESULTS: Silicon was identified within the fibrous breast capsule of each case, associated with a chronic inflammatory cell infiltrate. Silicon was also identified within tissues involved by chronic inflammation and fibrosis, namely, synovium, skin, and alveolar macrophages, in association with clinical, serologic, and histologic evidence of connective tissue disease. All three patients improved after removal of the silicone-gel breast implants. CONCLUSIONS: The presence of silicon-containing material within sites of connective-tissue disease supports a role for silicon in the origin or pathogenesis of such conditions in patients with silicone-gel breast implants. All patients with connective-tissue disease should be questioned about exposure to various forms of silicon. In those patients with known exposure, tissue specimens should be examined carefully for silicon-containing material and, if found, the source should be removed.

Annular epidermolytic ichthyosis: a unique phenotype.

A 30-year-old white woman developed bullous and ichthyosiform skin lesions at the age of 8 months. Blistering ceased at puberty, but the hyperkeratotic plaques persisted. She subsequently delivered five children, two of whom were affected with a bullous type of ichthyosis. At the age of 27 years, she developed numerous annular and polycyclic, erythematous, hyperkeratotic plaques on the trunk and extremities that were pruritic, enlarged slowly, and then resolved. Histopathologic examination of these annular plaques revealed epidermolytic hyperkeratosis. Electron microscopic examination of the annular plaques showed interrupted perinuclear tonofilament rings consistent with either bullous ichthyotic erythroderma of Brocq or ichthyosis bullosa of Siemens. This kindred may represent a new phenotype of epidermolytic (acanthokeratolytic) ichthyosis.

Aspiration cytologic, ultrastructural, and DNA cytometric findings of solid and papillary tumor of the pancreas.

Solid and papillary epithelial neoplasm of the pancreas (SPENP) is a rare lesion characteristically occurring in young women. By contrast with pancreatic ductal adenocarcinomas, SPENP is a slow-growing tumor that rarely metastasizes or is fatal. The current report describes light and electron microscopic and histochemical findings with DNA flow cytometric analyses of two cases of SPENP. The first patient was a 24-year-old woman; the second, a 72-year-old man. Although SPENP is rare in older men, both patients had characteristic radiographic and light microscopic features of SPENP. Ultrastructural evidence of acinar differentiation was seen in the first patient; the second patient had focal neuroendocrine differentiation. Flow cytometric analysis of the first tumor demonstrated diploid-range DNA content with a 5.8% S-phase fraction (SPF). The DNA cytometric analysis of a biopsy specimen from the second tumor revealed diploid-range DNA content with a 6.1% SPF, although subsequent sampling of the resected tumor showed an aneuploid population with a DNA index of 1.8 and SPF of 2.1%.

Oral neurofibrosarcoma associated with neurofibromatosis type I.

One of the most feared complications of neurofibromatosis type I (NF-I) is development of cancer, which is estimated to occur in about 5% of cases. The most common associated malignancy is the neurofibrosarcoma (NFS). HOwever, oral NFS in association with NF-I has rarely been reported. We report two cases of oral NFS arising in patients with NF-I. Both patients died of their tumors. Oral NFS arising in association with NF-I appears to have an extremely poor prognosis, as do these tumors at other sites of the body.

Juvenile xanthogranuloma of the paravertebral soft tissue in infancy: a report of two cases.

We report 2 cases of paravertebral soft tissue lesions with the histologic features of juvenile xanthogranuloma, both of which occurred in infants. Juvenile xanthogranuloma situated in the soft tissue is rare. We describe 2 cases with similar clinical and pathologic features; there has been no recurrence at 1 and 2 years after excision, respectively.

Multiple rhabdomyomatous mesenchymal hamartomas of skin.

A case of multiple rhabdomyomatous mesenchymal hamartomas is presented. The patient is a black male infant, the product of an uncomplicated term gestation and delivery. At birth, there were numerous polyps distributed over the periorbital and periauricular areas bilaterally. Some appeared fingerlike with constrictions below their tips. Others were branched or globular in shape. These projections showed spontaneous and independent movement, particularly during feedings. On histopathologic examination, the polyps were covered by squamous epithelium and contained normal follicular units. Bundles of skeletal muscle were present in the reticular dermis, extending into the subcutis. Regular cross-striations were seen in these muscle fibers. In some specimens, the muscle bundles formed a solid, central core. Skeletal muscle histochemical stains confirmed the presence of both types 1 and 2 muscle fibers. Electron microscopy revealed a normal skeletal muscle banding pattern. This case is the first report of multiple rhabdomyomatous mesenchymal hamartomas of skin. Functional skeletal muscle with spontaneous movement is part of the clinical picture.

Scleroderma following augmentation mammoplasty. Report of a case and review of the literature.

A 46-year-old woman developed localized scleroderma after surgical manipulation of her silicone gel-filled breast prostheses. She developed firm, shiny plaques on her legs that progressed to involve the thighs. Histopathologic examination of a deep-skin biopsy specimen confirmed the diagnosis of scleroderma. On surgical removal of the silicone implants, and their replacement with saline-filled implants, the scleroderma gradually resolved. Histopathologic examination of the removed implant capsules revealed evidence of silicone leakage. All new female patients with scleroderma should be questioned and examined regarding augmentation mammoplasty. Until prospective studies are completed on the possible association between scleroderma and silicone breast implants, it would seem prudent to use the saline-filled, elastomeric envelope-type breast implant for augmentation mammoplasty rather than the silicone gel-filled implant.

Preschool sarcoidosis masquerading as juvenile rheumatoid arthritis: two case reports and a review of the literature.

Preschool sarcoidosis is characterized by the triad of skin, joint, and eye disease without pulmonary involvement. Arthritis and uveitis are also frequently seen together in juvenile rheumatoid arthritis. We report two patients with preschool sarcoidosis, both of whom were initially diagnosed and treated as having juvenile rheumatoid arthritis. Skin biopsy is an important early diagnostic procedure to differentiate the conditions. The uveitis in both diseases can have serious sequelae.

Pyoderma gangrenosum in pediatric acquired immunodeficiency syndrome.

We describe two children with human immunodeficiency virus infection in whom pyoderma gangrenosum developed. Although pyoderma gangrenosum most commonly occurs in children with inflammatory bowel disease, it has also been described in patients with a variety of immunodeficiencies. In such patients a vigorous search to exclude a treatable infection should be made before the lesions are treated as pyoderma gangrenosum.