The origin and nature of stromal osteoclast-like multinucleated giant cells in breast carcinoma: implications for tumour osteolysis and macrophage biology

The origin and nature of osteoclast-like multinucleated giant cells (OMGCs), in extraskeletal neoplasms, is uncertain. The ultrastructure, antigenic phenotype and function of OMGCsm in a breast carcinoma were studied in order to clarify the relationship between OMGCs, osteoclasts and other cells of the mononuclear phagocyte system (MPS). OMGCs resorbed cortical bone in a manner similar to osteoclasts. However, unlike osteoclasts, OMGCs did not possess a ruffled border or clear zone, and expressed HLA-DR and Fc receptors and CD14, CD16, CD18 and CD11 (p150,95) antigens. In addition, OMGCs failed to respond morphologically to calcitonin and were directly stimulated by parathyroid hormone (PTH) to increase bone resorption. These findings suggest that OMGCs are a specific type of macrophage polykaryon distinct from both osteoclasts and other types of inflammatory polykaryon. Occasional smaller (20-25 microns) macrophage-like cells were also associated with resorption pits. Bone resorption by OMGCs isolated from the breast indicates that a cell of the MPS can be transplanted to a new tissue location and perform a highly specialised function appropriate to an MPS cell of that tissue (i.e. the osteoclast). PTH stimulation of bone resorption by OMGCs suggests that PTH or a PTH-like protein, may be involved in the bone resorption and consequent hypercalcaemia associated with metastatic breast cancer.     

Tolerance of ocular iontophoresis in healthy volunteers.

To evaluate ocular tolerance, healthy volunteers were iontophoresed transclerally using novel OcuPhor trade mark hydrogel drug delivery applicators filled with balanced salt solution. In this three-period crossover study in 24 male and female subjects, 16 subjects received 0 mA and two of the following DC currents: 0.1, 0.5., 1.0, 2.0, 3.0, or 4.0 mA for 20 min; 6 subjects received 3 mA for 20 min and 1.5 mA for 40 min (both equivalent to 60 mAmin total charge). Safety and tolerance were determined by subjective VAS and objective ophthalmic assessments. Subjects were evaluated before and up to 22 hr after dosing. The applicators were well-tolerated and no clinically significant changes in symptomology or in ophthalmic assessments were seen following exposure to 0-3.0 mA for 20 min or 1.5 mA for 40 min. At 4.0 mA 2 of 4 subjects reported a burning sensation under the applicator during dosing which resolved by 22 hr post-dose; superficial changes in fluorescein staining were observed at 1 hr, but not at 22 hr. The OcuPhor trade mark system has promise for noninvasive drug delivery to the eye.     

The remucosalizing alar cartilage flap: a reconstructive option for repairing nasal septal perforations

The objective of this study is to assess the results of repairing septal perforations with a vascularized pedicled alar cartilage island flap. Using the external rhinoplasty approach, a vascularized flap of alar cartilage, harvested as a cephalic trim and pedicled on the ascending columellar branches of the superior labial artery was raised. Bilateral mucoperichondrial septal flaps were elevated and the alar flap was transposed and secured within the defect and bilaterally overlaid with temporalis fascia. Silastic sheets were placed and remained in situ until the grafts were revascularized from the peripheries of the defect as well as centrally from the alar flap. The revascularized temporalis fascia acted as a scaffold for nasal remucosalization. The alar flap also increased the long-term structural robustness of the repair. Between 1999 and 2003, 14 patients with septal perforations ranging from 10 to 31 mm underwent septal reconstruction using this technique. There were nine males and five females. The flap was successfully raised in all cases and long-term closure was maintained in 12 patients (86%). The alar cartilage flap is an effective technique for repairing septal perforations in selected patients. It provides vascularized tissue which nourishes the grafts during remucosalization, and a cartilaginous framework, which affords long-term structural support to the repair. It also obviates the need to transpose nasal mucosa and create a secondary defect. The rhinoplasty approach furthermore permits additional nasal deformities to be corrected at the same time. Presented at the British Association of Plastic Surgeons Summer Scientific Meeting, Sheffield, UK (12 July 2006).     

Comparative dermal carcinogenesis of shale and petroleum-derived distillates

Ten test materials derived from petroleum or hydrotreated shale oils were applied 3 times/week for up to 105 weeks to the shaved skin of 25 male and 25 female C3H/HeN mice per group. Mineral oil and benzo(a) pyrene (0.15%) were control materials. Clinical observations were recorded during the study. At death, histopathologic examination was conducted on skin, internal organs and any gross lesions. Exposures to some materials were ended midway in the study due to severe irritation. Chronic toxicity of all materials was limited to inflammatory and degenerative skin changes. Significant increases over control incidence of skin tumors (squamous cell carcinoma and fibrosarcoma) occurred with both petroleum and shale-derived naphtha (21%, 50%), Jet A (26%, 28%), JP-4 (26%, 50%), and crude oils (84%, 54%). Severely hydrotreated shale oil and petroleum and shale-derived diesel distillates were not considered tumorigenic. Results indicate that toxicity of comparable petroleum and shale-derived fractions was qualitatively similar and confirm earlier findings that hydrotreating reduces or eliminates carcinogenicity of raw shale oil.     

Photopatch testing: a consensus methodology for Europe

A group of interested European Contact Dermatologists/Photobiologists met to produce a consensus statement on methodology, test materials and interpretation of photopatch testing. While it is recognized that a range of local variables operate throughout Europe, the underlying purpose of the work is to act as an essential preamble to a Pan European Photopatch Test Study focusing particularly on sunscreen chemicals.     

The impact of poverty on educational outcomes for children

Over the past decade, the unfortunate reality is that the income gap has widened between Canadian families. Educational outcomes are one of the key areas influenced by family incomes. Children from low-income families often start school already behind their peers who come from more affluent families, as shown in measures of school readiness. The incidence, depth, duration and timing of poverty all influence a child’s educational attainment, along with community characteristics and social networks. However, both Canadian and international interventions have shown that the effects of poverty can be reduced using sustainable interventions. Paediatricians and family doctors have many opportunities to influence readiness for school and educational success in primary care settings.