Usefulness of image guidance in the surgical treatment of petrous apex cholesterol granuloma

The petrous apex is a pyramid-shaped structure, located medial to the inner ear and the intrapetrous segment of the internal carotid artery. Lesions of the petrous apex can be surgically treated through different surgical routes. Because of the important neurovascular structures located inside the temporal bone, anatomical 3D knowledge is paramount. For this reason, image-guided surgery could represent a useful tool. We report the case of a young woman who came to our observation for a trigeminal neuralgia due to a petrous apex cholesterol granuloma. The lesion was treated through the placement of a drainage tube via an infracochlear approach, with the aid of neuronavigation and intraoperative MRI. Preoperative CT scan images and intraoperative MRI images were fused for surgical planning. The accuracy of the neuronavigation system has proved to be good, and the safety of the procedure was enhanced. Therefore, neuronavigation and intraoperative MRI, though not available in all neurootological centres, should be considered useful tools in these challenging procedures

Polariton-polariton scattering in microcavities: A microscopic theory

We apply the fermion commutation technique for composite bosons to polariton-polariton scattering in semiconductor planar microcavities. Derivations are presented in a simple and physically transparent fashion. A procedure of orthogonolization of the initial and final two-exciton state wavefunctions is used to calculate the effective scattering matrix elements and the scattering rates. We show how the bosonic stimulation of the scattering appears in this full fermionic approach whose equivalence to the bosonization method is thus demonstrated in the regime of low exciton density. We find an additional contribution to polariton-polariton scattering due to the exciton oscillator strength saturation, which we analyze as well. We present a theory of the polariton-polariton scattering with opposite spin orientations and show that this scattering process takes place mainly via dark excitonic states. Analytical estimations of the effective scattering amplitudes are given.Comment: Theoretical paper on polariton-polariton scattering in planar microcavities. The new version contains a slightly modified abstract and a revised introduction. Typos have been corrected wherever spotted. 16 page

Correction of prominent ears with a new splinting technique

Correction of prominent ears represents one of the main applications in plastic surgery. Apart from its cosmetic nature, this operation is important because of the psychological distress that the deformity causes patients. In this study, 40 patients who underwent treatment for prominent ears in our department were evaluated. The classical surgical technique described by Chongchet followed by a new splinting procedure was performed. The advantages of this technique are described in comparison with traditional methods

Subalgebras of \gc_N and Jacobi polynomials

We classify the subalgebras of the general Lie conformal algebra \gc_N that act irreducibly on \C[\partial]^N and that are normalized by the $\operatorname{sl}_2$--part of a Virasoro element. The problem turns out to be closely related to classical Jacobi polynomials $P_n^{(-\sigma,\sigma)}$, \sigma\in\C. The connection goes both ways -- we use in our classification some classical properties of Jacobi polynomials, and we derive from the theory of conformal algebras some apparently new properties of Jacobi polynomials.Comment: 35 pages, LaTe

Prognostic significance of primary-tumor extension, stage and grade of nuclear differentiation in patients with renal cell carcinoma

Surgery remains the preferred therapy for renal cell carcinoma. The various adjunctive or complementary therapies currently yield disappointing results. Identifying reliable prognostic factors could help in selecting patients most likely to benefit from postoperative adjuvant therapies. We reviewed the surgical records of 78 patients who had undergone radical nephrectomy with lymphadenectomy for renal cell carcinoma, matched for type of operation and histology. According to staging (TNM), 5.1% of the patients were classified as stage I, 51.3% as stage II, 29.5% as stage III and 14.5% as stage IV. Of the 78 patients 40 were T2N0 and 21 T3aN0. Tumor grading showed that 39.7% of the patients had well-differentiated tumors(G1), 41.1% moderately-differentiated (G2), and 19.2% poorly-differentiated tumors (G3). Overall actuarial survival at 5 and 10 years was 100% for stage 1; 91.3% at 5 years and 83.1% at 10 years for stage II; 45.5% and 34.1% for stage III; and 29.1% and nil for stage IV (stage II vs stage III p = 0.0001). Patients with tumors confined to the kidney (pT2N0) had better 5- and 10-year survival rates than patients with tumors infiltrating the perirenal fat (pT3aN0) (p = 0.000006). Survival differed according to nuclear grading (G1 vs G3 ; p = 0.000005; G2 vs G3; p = 0.0009). In conclusion our review identified tumor stage, primary-tumor extension, and the grade of nuclear differentiation as reliable prognostic factors in patients with renal cell carcinomas

External ultrasound-assisted lipectomy: effects on abdominal adipose tissue

The use of ultrasound “on the surface” was hypothesized by Scuderi et al. in 19871 and resumed by Zocchi in 1996.2 Ultrasound-assisted liposuction is as a technique that can be associated with suctionassisted lipectomy.3 This new technique is called external ultrasound-assisted lipectomy. Whereas ultrasound- assisted liposuction emulsifies adipose tissue due to adipocyte membrane lysis, external ultrasound- assisted lipectomy, being less “invasive,” induces cell-to-cell contact loss and alters collagenic fibers. This leads to an easier detachment of adipose cells, which remain unaltered and can be mechanically removed. The external ultrasound-assisted lipectomy technique is the transcutaneous application of ultrasound by means of high-frequency ultrasound upon massive infiltrated tissue, followed by traditional liposuction. Results showed that several different effects were detected on both adipocytes and collagen fibers

Sustaining the Medical Home: How PROMETHEUS Payment Can Revitalize Primary Care

Argues for reforming the current fee-for-service payment system on the PROMETHEUS model of budgeting for a comprehensive episode of care for a condition. Analyzes the implications for a sustainable patient-centered medical home model of care delivery