Collective Modes in Excitonic Magnets: Dynamical Mean-Field Study.

We present a dynamical mean-field study of dynamical susceptibilities in the two-band Hubbard model. Varying the model parameters we analyze the two-particle excitations in the normal as well as in the ordered phase, an excitonic condensate. The two-particle dynamical mean-field theory spectra in the ordered phase reveal the gapless Goldstone modes arising from spontaneous breaking of continuous symmetries. We also observe the gapped Higgs mode, characterized by vanishing of the gap at the phase boundary. Qualitative changes observed in the spin susceptibility can be used as an experimental probe to identify the excitonic condensation.

Spontaneous Spin Textures in Multiorbital Mott Systems.

Spin textures in k-space arising from spin-orbit coupling in noncentrosymmetric crystals find numerous applications in spintronics. We present a mechanism that leads to the appearance of k-space spin texture due to spontaneous symmetry breaking driven by electronic correlations. Using dynamical mean-field theory we show that doping a spin-triplet excitonic insulator provides a means of creating new thermodynamic phases with unique properties. The numerical results are interpreted using analytic calculations within a generalized double-exchange framework.

Clinical abnormalities of the nipple-areola complex: The role of imaging.

Clinical examination of the nipple is part of normal breast screening procedures. Abnormal processes of benign or malignant nature may be reflected by erythema, erosion, swelling or acquired inversion. In patients presenting with a persistent unilateral nipple lesion, it is advisable to collect a sample to exclude Paget's disease of the nipple, a rare form of ductal carcinoma in situ (DCIS). Imaging should be performed to detect breast cancer, which is found in more than 80% of cases, and determine its possible multifocal nature. Breast MRI is indicated if breast-conserving surgery is planned. The main differential diagnoses are erosive adenomatosis and eczema of the nipple. Acquired inverted nipple is generally of inflammatory origin. It is usually diagnosed by conventional breast examination but breast MRI can be helpful when in doubt about possible underlying neoplasia.

[Paget's disease of the nipple and differential diagnosis]. / Maladie de Paget du mamelon et principaux diagnostics différentiels.

Clinical evaluation of the nipple-areolar complex is a routine component of the breast screening examination. All persistent unilateral nipple lesion should be viewed with suspicion and Paget's disease of the nipple should be considered. The diagnosis is established by nipple scrape cytology. It is a rare variant of ductal carcinoma in situ. The breast imaging work-up should include a search for an underlying malignancy, present in over 80% of cases, not infrequently multifocal. Preoperative MRI is useful if breast conservative surgery is contemplated because of the high rate of occult malignancy on mammograms and ultrasound. Erosive adenomatosis of the nipple is a benign process that may simulate Paget's disease isolated to the nipple. Less frequently, pagetoid basal cell carcinoma, Bowen's disease and melanoma may be more difficult to differentiate clinically and share the unilateral and chronic features of Paget's disease. Biopsy is needed for diagnosis. Cutaneous extension of a breast cancer is rare but should be suspected in patients with retraction and/or fixed nipple. Eczema is characterized by the bilateral nature of the process, the absence of nipple deformity, the presence of flare-ups and the favorable response to local steroid therapy.

[Lupus profundus and myelopathy]. / Lupus profond et myélopathie.

BACKGROUND: We report a case of myelopathy during the course of lupus profundus that is unique to our knowledge. CASE-REPORT: A 29-year-old woman had lupus profundus since 1999, initially associated with thrombopenia (28,000 platelets/mm3) treated with corticosteroids for 6 months. Several nodular eruptions occurred from 1999 to 2004. Antinuclear antibodies were positive at 1/320 to 1/640 and complement C4 fraction was low. While being treated with hydroxychloroquine for a recent flare-up of nodular lesions of lupus profundus, she complained of paraesthesia of the abdominal wall and of the upper and lower limbs, suggestive of a medullary lesion. MRI disclosed an image of acute myelitis at the level of the second cervical vertebra. High doses of corticosteroids were promptly administered intravenously (methylprednisolone bolus) followed by oral prednisone and hydroxychloroquine. Six months later the patient was free of neurologic or cutaneous symptoms. DISCUSSION: In the literature, systemic signs are rarely associated with lupus profundus and myelitis has never been reported. Lupus myelitis is a vascular and/or demyelinating and usually segmental lesion of the spinal cord. Neurologic symptoms are those of acute rather than chronic or recurrent transverse myelitis. The prognosis is poor with frequent and severe functional sequelae. Treatment is mainly based on high-dose systemic corticotherapy alone or combined with cyclophosphamide. Our patient responded favourably to early methylprednisolone bolus followed by oral corticosteroids and antimalarial treatment. CONCLUSION: Lupus profundus is classically of benign course with only cutaneous involvement, but it may sometimes be a sign of systemic lupus and in rare cases may be associated with severe complications.

Primary malignant lymphoma of the urinary bladder: report of three cases and review of the literature.

We report three cases of a primary malignant lymphoma of the urinary bladder. The radiological features revealed a sessile mass of the lateral wall for one case, a circumferential thickening in the second, and two separated masses of the bladder wall in the last case. Primary malignant lymphoma of the urinary bladder is extremely rare. From a review of the literature, the clinical and radiological findings are discussed. In this paper we report the first case of urinary bladder lymphoma presented on CTas multiple masses.

[Assessment of the systematic preoperative insertion of an intra-aortic counterpulsation balloon in patients at high operative risk for coronary artery surgery]. / Bilan de la mise en place systématique d'un ballon de contre-pulsion intra-aortique pré-opératoire chez les coronariens à haut risque chirurgical.

The authors report their experience with pre-operative percutaneous balloon counterpulsation in 75 patients considered to be at high operative risk for coronary artery surgery, mainly because of unstable angina refractory to maximum medical therapy. The criteria to define high surgical risk are reported. The results and the vascular risk in relation to this technique are estimated. Two patients died during the operation, 12 died during the early postoperative phase without any improvement following intra-aortic balloon pumping. The rate and severity of complications of percutaneous insertion of intra-aortic balloon counterpulsation are low and seem to be related to pre-existing arteriosclerosis. The stabilizing effect of this pre-operative insertion on angina, refractory to medical treatment, seems to be justifiable in patients presenting one of the defined criteria.

[Slow-wave paradoxical sleep during the 1st year of life]. / Le sommeil paradoxal à ondes lentes au cours de la première année de vie.

A typical aspect of the EEG during Paradoxical Sleep (PS) was noted in 76% of 68 infants, 3 to 11 months old. This consisted in delta waves of high amplitude recorded during PS. These waves were seen from the beginning to the end of the first year of life; they could occupy all or part of each stage of PS and were seen at any time during the night. Few works have been published by other authors on the same subject. However, Tanguay et al. (1974) have observed that high delta waves in PS were present until four and a half year of age and that the relative delta power in PS decreased slowly between the first and fifth year of life. The problem consisted in finding out whether this type of tracing was related to the immaturity of some brain structures.

Delta, theta, alpha and beta power spectrum of sleep electroencephalogram in infants aged two to eleven months.

Automatic sleep EEG analysis was performed on infants from 2 to 11 months of age. Partial power spectra of delta, theta, alpha, and beta 1 bands were studied as function of sleep stages, age, and time of the night. beta 1, alpha, and delta power spectra are significantly lower in paradoxical sleep (PS) than in quiet sleep (QS) whatever the age; but theta is lower in PS than in QS only after 5 months of age. delta, theta, and alpha power increase with age in QS. Only delta and theta are greater in the first half of the night than in the second half. beta 1 power does not differ significantly in stages 2 and 3 of QS, during the course of the night or as a function of age. Thus delta, theta, alpha may be the best spectral parameters for the maturation of quiet sleep EEGs during the first year of life.

[Realization of a system which permits automatic analysis of sleep of infants (2-12 months)]. / Realisation d'un systeme automatique permettant de coder le sommeil des nourrissons (2 a 12 mois).

We have developed a system which permits automatic analysis of sleep of infants from 2 to 12 months of age. It is based on the calculation of a score on the basis of 6 parameters weighted according to their importance in determining the different phases of sleep. We use 3 EEG parameters derived from spectral analysis of the Cz-Oz derivation: total spectral energy (Hjorth activity), energy of the delta band, and energy of the beta band, and 3 polygraphic parameters: variability of muscle activity in each minute, variability of the respiratory frequency and presence or absence of rapid eye movements. The analysis provides a list of the sleep phases, minute by minute, and a traditional sleep diagram; we also calculate the successive appearances of the different sleep phases, in 10 min periods, and schematize these results in a diagram which shows the general trend of each sleep phase during the night. When compared with visual analysis, these results are satisfactory, since we observe on average 86.2% agreement in the differentiation of calm, paradoxical and transitional sleep, and 76.4% agreement in the differentiation of stages II, III and IV of calm sleep.