The mitotic kinase Aurora--a promotes distant metastases by inducing epithelial-to-mesenchymal transition in ERα(+) breast cancer cells.

In this study, we demonstrate that constitutive activation of Raf-1 oncogenic signaling induces stabilization and accumulation of Aurora-A mitotic kinase that ultimately drives the transition from an epithelial to a highly invasive mesenchymal phenotype in estrogen receptor α-positive (ERα(+)) breast cancer cells. The transition from an epithelial- to a mesenchymal-like phenotype was characterized by reduced expression of ERα, HER-2/Neu overexpression and loss of CD24 surface receptor (CD24(-/low)). Importantly, expression of key epithelial-to-mesenchymal transition (EMT) markers and upregulation of the stemness gene SOX2 was linked to acquisition of stem cell-like properties such as the ability to form mammospheres in vitro and tumor self-renewal in vivo. Moreover, aberrant Aurora-A kinase activity induced phosphorylation and nuclear translocation of SMAD5, indicating a novel interplay between Aurora-A and SMAD5 signaling pathways in the development of EMT, stemness and ultimately tumor progression. Importantly, pharmacological and molecular inhibition of Aurora-A kinase activity restored a CD24(+) epithelial phenotype that was coupled to ERα expression, downregulation of HER-2/Neu, inhibition of EMT and impaired self-renewal ability, resulting in the suppression of distant metastases. Taken together, our findings show for the first time the causal role of Aurora-A kinase in the activation of EMT pathway responsible for the development of distant metastases in ERα(+) breast cancer cells. Moreover, this study has important translational implications because it highlights the mitotic kinase Aurora-A as a novel promising therapeutic target to selectively eliminate highly invasive cancer cells and improve the disease-free and overall survival of ERα(+) breast cancer patients resistant to conventional endocrine therapy.

High-fidelity, inexpensive surgical middle ear simulator.

HYPOTHESIS: A high-fidelity, inexpensive middle ear simulator could be created to enhance surgical training that would be rated as having high face validity by experts. BACKGROUND: With rapid prototyping using additive manufacturing technology (AMT), one can create high-resolution 3-dimensional replicas of the middle ear at low cost and high fidelity. Such a simulator could be of great benefit for surgical training, particularly in light of new resident training guidelines. METHODS: AMT was used to create surgical middle ear simulator (SMS) with 2 different materials simulating bone and soft tissue. The simulator is composed of an outer box with dimensions of an average adult external auditory canal without scutum and an inner cartridge based on an otosclerosis model. The simulator was then rated by otology experts in terms of face validity and fidelity as well as their opinion on the usefulness of such a device. RESULTS: Eighteen otologists from 6 tertiary academic centers rated the simulator; 83.3% agreed or highly agreed that SMS has accurate dimensions and 66.6% that it has accurate tactile feedback. When asked if performance of stapedotomy with the SMS improves with practice, 46% agreed. As to whether practicing stapedotomy with the SMS translates to improvement with live surgery, 78% agreed with this statement. Experts' average rating of the components of SMS (of possible 5) was as follows: middle ear dimensions, 3.9; malleus, 3.7; incus, 3.6; stapes, 3.6; chorda tympani, 3.7; tensor tympani, 4.1; stapedius, 3.8; facial nerve, 3.7; and promontory, 3.5. Overall, 83% found SMS to be at least "very useful" in training of novices, particularly for junior and senior residents. CONCLUSION: Most experts found the SMS to be accurate, but there was a large discrepancy in rating of individual components. Most found it to be very useful for training of novice surgeons. With these results, we are encouraged to proceed with further refinements that will strengthen the SMS as a training tool for otologic surgery.

Acquired epidermodysplasia verruciformis due to multiple and unusual HPV infection among vertically-infected, HIV-positive adolescents in Zimbabwe.

BACKGROUND: We have previously described the presentation of epidermodysplasia verruciformis (EV)-like eruptions in almost a quarter of hospitalized adolescents with vertically-acquired human immunodeficiency virus (HIV) infection in Harare, Zimbabwe, a region with a high prevalence of HIV infection. METHODS: We performed a clinical case note review and skin biopsy from affected sites in 4 HIV-infected adolescents with EV-like lesions in Harare. Biopsies were processed for histology and for human papillomavirus (HPV) typing. RESULTS: All patients had long-standing skin lesions that pre-dated the diagnosis of HIV by several years. The histology of skin biopsies from all patients was consistent with EV. In each biopsy, EV-associated ß-HPV type 5 was identified (additionally, type 19 was found in 1 biopsy). Cutaneous wart-associated HPV types 1 and 2 were detected in all biopsies, together with genital lesion-associated HPV types 6, 16, and 52, (as well as ≥3 other genital lesion-associated HPV types). Despite immune reconstitution with combination antiretroviral therapy (cART), there was no improvement in EV-like lesions in any patient. CONCLUSIONS: EV is a disfiguring and potentially stigmatizing condition among this patient group and is difficult to treat; cART appears to have no impact on the progression of skin disease. Among adolescents with longstanding HIV-induced immunosuppression and with high levels of sun exposure, close dermatological surveillance for potential skin malignancy is required.

Single-walled carbon nanotube-induced mitotic disruption.

Carbon nanotubes were among the earliest products of nanotechnology and have many potential applications in medicine, electronics, and manufacturing. The low density, small size, and biological persistence of carbon nanotubes create challenges for exposure control and monitoring and make respiratory exposures to workers likely. We have previously shown mitotic spindle aberrations in cultured primary and immortalized human airway epithelial cells exposed to 24, 48 and 96 µg/cm(2) single-walled carbon nanotubes (SWCNT). To investigate mitotic spindle aberrations at concentrations anticipated in exposed workers, primary and immortalized human airway epithelial cells were exposed to SWCNT for 24-72 h at doses equivalent to 20 weeks of exposure at the Permissible Exposure Limit for particulates not otherwise regulated. We have now demonstrated fragmented centrosomes, disrupted mitotic spindles and aneuploid chromosome number at those doses. The data further demonstrated multipolar mitotic spindles comprised 95% of the disrupted mitoses. The increased multipolar mitotic spindles were associated with an increased number of cells in the G2 phase of mitosis, indicating a mitotic checkpoint response. Nanotubes were observed in association with mitotic spindle microtubules, the centrosomes and condensed chromatin in cells exposed to 0.024, 0.24, 2.4 and 24 µg/cm(2) SWCNT. Three-dimensional reconstructions showed carbon nanotubes within the centrosome structure. The lower doses did not cause cytotoxicity or reduction in colony formation after 24h; however, after three days, significant cytotoxicity was observed in the SWCNT-exposed cells. Colony formation assays showed an increased proliferation seven days after exposure. Our results show significant disruption of the mitotic spindle by SWCNT at occupationally relevant doses. The increased proliferation that was observed in carbon nanotube-exposed cells indicates a greater potential to pass the genetic damage to daughter cells. Disruption of the centrosome is common in many solid tumors including lung cancer. The resulting aneuploidy is an early event in the progression of many cancers, suggesting that it may play a role in both tumorigenesis and tumor progression. These results suggest caution should be used in the handling and processing of carbon nanotubes.

A virtual surgical environment for rehearsal of tympanomastoidectomy.

This article presents a virtual surgical environment whose purpose is to assist the surgeon in preparation for individual cases. The system constructs interactive anatomical models from patient-specific, multi-modal preoperative image data, and incorporates new methods for visually and haptically rendering the volumetric data. Evaluation of the system's ability to replicate temporal bone dissections for tympanomastoidectomy, using intraoperative video of the same patients as guides, showed strong correlations between virtual and intraoperative anatomy. The result is a portable and cost-effective tool that may prove highly beneficial for the purposes of surgical planning and rehearsal.

In vivo micro-image mosaicing.

Recent advances in optical imaging have led to the development of miniature microscopes that can be brought to the patient for visualizing tissue structures in vivo. These devices have the potential to revolutionize health care by replacing tissue biopsy with in vivo pathology. One of the primary limitations of these microscopes, however, is that the constrained field of view can make image interpretation and navigation difficult. In this paper, we show that image mosaicing can be a powerful tool for widening the field of view and creating image maps of microanatomical structures. First, we present an efficient algorithm for pairwise image mosaicing that can be implemented in real time. Then, we address two of the main challenges associated with image mosaicing in medical applications: cumulative image registration errors and scene deformation. To deal with cumulative errors, we present a global alignment algorithm that draws upon techniques commonly used in probabilistic robotics. To accommodate scene deformation, we present a local alignment algorithm that incorporates deformable surface models into the mosaicing framework. These algorithms are demonstrated on image sequences acquired in vivo with various imaging devices including a hand-held dual-axes confocal microscope, a miniature two-photon microscope, and a commercially available confocal microendoscope.

Subcutaneous calcification presenting in a patient with mixed connective tissue disease and cutaneous polyarteritis nodosa.

Subcutaneous calcification often occurs in connective tissue diseases, most commonly scleroderma and dermatomyositis, but is rarely found in mixed connective tissue disease (MCTD). Cutaneous polyarteritis nodosa (PAN) is usually a primary skin disorder and although associated with connective tissue disease, has not been reported previously in MCTD. Calcinosis in cutaneous PAN is not a recognized feature. We describe the case of a 37-year-old woman who presented with tender ulcerated subcutaneous nodules on the lower legs consistent with cutaneous PAN, and she also showed features of MCTD with extensive secondary subcutaneous calcification. The use of systemic immunosuppressive treatment has improved the clinical features of PAN and MCTD but treatment of the calcification has proved challenging. No single medical or surgical treatment has been shown to be consistently effective in subcutaneous calcification, but the introduction of diltiazem in our patient has resulted in some improvement.

Multiple organ failure and severe bone marrow dysfunction in two 18 year-old Caucasian patients: Epstein-Barr virus and the haemophagocytic syndrome.

Haemophagocytic lymphohistiocytosis secondary to viral infection is an unusual but well recognised cause of bone marrow dysfunction and multiple organ failure in young patients. Two 18 year-old patients were admitted to a tertiary liver unit with features of acute liver failure, cardio-respiratory collapse and pancytopenia. Serological tests and bone marrow examination with in-situ hybridisation revealed severe acquired haemophagocytic lymphohistiocytosis secondary to acute Epstein-Barr virus infection. Both patients died despite full supportive therapy; the first due to pulmonary haemorrhage, the second due to acute respiratory distress syndrome refractory to high frequency oscillatory ventilation. The clinical spectrum, diagnostic features and current evidence based recommendations for treatment of this condition are explored. The diagnosis of haemophagocytic lymphohistiocytosis should be considered in young patients with marked bone marrow dysfunction and multiple organ failure. Further research into appropriate therapy for patients with acute severe forms of the disease who require intensive organ support is required.

Impaired p53 function leads to centrosome amplification, acquired ERalpha phenotypic heterogeneity and distant metastases in breast cancer MCF-7 xenografts.

In this study, we establish an MCF-7 xenograft model that mimics the progression of human breast carcinomas typified by loss of p53 integrity, development of centrosome amplification, acquired estrogen receptor (ERalpha) heterogeneity, overexpression of Mdm2 and metastatic spread from the primary tumor to distant organs. MCF-7 cells with abrogated p53 function (vMCF-7(Dnp53)) maintained nuclear ERalpha expression and normal centrosome characteristics in vitro. However, following mitogen stimulation, they developed centrosome amplification and a higher frequency of aberrant mitotic spindles. Centrosome amplification was dependent on cdk2/cyclin activity since treatment with the small molecule inhibitor SU9516 suppressed centriole reduplication. In contrast to the parental MCF-7 cells, when introduced into nude mice as xenografts, tumors derived from the vMCF-7(DNp53) cell line developed a strikingly altered phenotype characterized by increased tumor growth, higher tumor histopathology grade, centrosome amplification, loss of nuclear ERalpha expression, increased expression of Mdm-2 oncoprotein and resistance to the antiestrogen tamoxifen. Importantly, while MCF-7 xenografts did not develop distant metastases, primary tumors derived from vMCF-7(DNp53) cells gave rise to lung metastases. Taken together, these observations indicate that abrogation of p53 function and consequent deregulation of the G1/S cell cycle transition leads to centrosome amplification responsible for breast cancer progression.

Complete response of deep neutrophilic dermatosis associated with myelodysplastic syndrome to 5-azacytidine.

Cutaneous manifestations of myelodysplastic syndromes (MDS) may predict disease progression and a poorer prognosis. We describe a patient in whom a deep neutrophilic dermatosis preceded evolution of disease from refractory anaemia to RAEB (refractory anaemia with excess blasts) and resolved completely on treating the disease with 5-azacytidine. The dermatological response was accompanied by complete bone marrow remission and trilineage haematological improvement. We suggest that 5-azacytidine should be considered in the treatment of immune mediated cutaneous manifestations of MDS.

Sclerodermatous graft-versus-host disease: clinical spectrum and therapeutic challenges.

Sclerodermatous graft-versus-host disease (GVHD) is a rare complication of bone marrow transplantation. While GVHD is often associated with the beneficial graft vs. tumour effect, it also contributes towards significant morbidity and mortality. No reliably effective treatment has yet been established. We present 10 patients with haematological malignancies who underwent an allogeneic stem cell transplant and developed sclerodermatous GVHD. Donor lymphocyte infusion administered for relapse or reducing donor T-cell chimerism was a known trigger for sclerodermatous GVHD in four of the patients. Treatment with immunosuppressants, psoralen plus ultraviolet A (PUVA) and extracorporeal photopheresis has been largely unsuccessful in their management. Intensive immunosuppression including the use of anti-CD20 monoclonal antibody may have contributed to relapse of leukaemia in one patient 10 years after her transplant. Sclerodermatous GVHD may occur without a preceding lichenoid stage. Clinical heterogeneity is common, although sclerodermatous GVHD has a predilection for the limbs. Treatment options are largely unsatisfactory if conventional immunosuppression fails. PUVA may give some symptomatic benefit and extracorporeal photopheresis seems to be less efficacious than previously published work suggests.

Saccharomyces cerevisiae emboli in an immunocompromised patient with relapsed acute myeloid leukaemia.

In humans, Saccharomyces cerevisiae (baker's yeast) is found infrequently as a commensal of mucosal surfaces and rarely causes infections. We describe a case of cutaneous septic emboli developing in a patient with relapsing acute myeloid leukaemia M6 who had recently been treated with clofarabine. Yeast forms were seen on skin biopsy and S. cerevisiae was isolated from her Hickman line. We are not aware of any previous case reports of cutaneous emboli associated with this organism.