[Thrombotic skin gangrene: A rare extra-intestinal manifestation of ulcerative colitis]. / La gangrène cutanée thrombotique : une manifestation extradigestive rare de la rectocolite hémorragique.

BACKGROUND: Thrombotic cutaneous gangrene is a rare extra-intestinal manifestation of ulcerative colitis with a severe prognosis. CASE REPORT: A 35-year-old woman with a 7-year history of ulcerative colitis presented with extensive ecchymotic lesions that began a few hours earlier. On examination, she was febrile with multiple necrotic lesions. Skin biopsy showed multiple microthrombi in the dermal vessels. A diagnosis of thrombotic cutaneous gangrene was established. The patient was treated with heparin and systemic corticosteroids. The majority of cutaneous lesions showed improvement after 1 month. Thrombophlebitis of the left lower limb occurred subsequently. CONCLUSION: Thrombotic cutaneous gangrene is attributed to microvascular thrombosis, which arises from the hypercoagulability observed in ulcerative colitis. Complete blood and coagulation tests must be performed and early anticoagulation with heparin must be considered in order to prevent the progression of cutaneous infarction.

[Bowel-associated dermatosis-arthritis syndrome during ulcerative colitis: A rare extra-intestinal sign of inflammatory bowel disease]. / Syndrome arthro-cutané lors d'une rectocolite ulcéro-hémorragique : une manifestation extra-intestinale rare des maladies inflammatoires de l'intestin.

INTRODUCTION: Bowel-associated dermatosis-arthritis syndrome (BADAS) is characterized by combined pustular skin eruption and arthralgia. It may be associated with inflammatory bowel disease or bowel bypass surgery. We report a case of BADAS in a patient with ulcerative colitis. CASE REPORT: A 39-year-old woman was being treated for a severe flare-up of ulcerative colitis present over the preceding 2 months and treated with prednisone, azathioprine and cyclosporine. She was also presenting a cutaneous eruption and arthralgia that had begun three days earlier. Dermatological examination revealed profuse vesicular and pustular lesions. Biopsy specimens showed mature neutrophilic infiltrate within the dermis. A diagnosis of BADAS was made and the same treatment was maintained. Systemic symptoms were resolved but the vesicular lesions were superseded by hypertrophic scars. DISCUSSION: Bowel-associated dermatosis-arthritis syndrome consists of a vesiculopustular eruption associated with arthralgia and/or arthritis and fever, as was the case in our patient. The histological picture is characterized by abundant neutrophilic infiltrate in the superficial dermis. The clinical and histological features and the course of BADAS allow this entity to be classified within the spectrum of neutrophilic dermatoses. Treatment chiefly involves systemic corticosteroids.

Adsorption of polyvinylpyrrolidone on Ag surfaces: insight into a structure-directing agent.

We use density functional theory to resolve the role of polyvinylpyrrolidone (PVP) in the shape-selective synthesis of Ag nanostructures. At the segment level, PVP binds more strongly to Ag(100) than Ag(111) because of a surface-sensitive balance between direct binding and van der Waals attraction. At the chain level, correlated segment binding leads to a strong preference for PVP bind to Ag(100). Our study underscores differences between small-molecule and polymeric structure-directing agents.

[Analysis of 18 Tunisian cases of mycetoma at the Sousse hospital (1974-2010)]. / Analyse d'une série tunisienne de 18 cas de mycétomes à l'hôpital de Sousse (1974-2010).

Mycetoma are inflammatory pseudotumors, due to infection by bacterial (Actinomycetoma) or fungal (Eumycetoma) agent. A retrospective study was conducted during 34 years. Our aim was to study epidemiologic, clinic, therapeutic and microbiologic characteristics. Eighteen patients were assessed. Sex-ratio H/F was 2. The mean age was 43.6 years. Principal localization was the feet. Our study was characterized by majority of actinomycetoma found in 15 cases (Actinomadura madurae in 14 cases and Nocardia sp. in one case). Eumycetoma were diagnosed in 3 cases (Madurella mycetomatis in two cases and Pseudallesheria in one case). All patients received medical treatment associated with surgical treatment in 11 cases.

Resonance Raman spectra of TNT and RDX using vibronic theory, excited-state gradient, and complex polarizability approximations.

Geometries, UV absorption bands, and resonance Raman (RR) cross sections of TNT and RDX are investigated using density functional theory (DFT) in conjunction with the Coulomb attenuated B3LYP exchange-correlation functional. The absorption and RR spectra are determined with use of vibronic (VB) theory, excited-state gradient, and complex polarizability (CPP) approximations. We examined low-energy isomers (two for TNT and four for RDX) whose energies differ by less than 1 kcal/mol, such that they would appreciably be populated at room temperature. The two TNT isomers differ by an internal rotation of the methyl group, while the four conformers of RDX differ by the arrangements of the nitro group relative to the ring. Our theoretical optical properties of the TNT and RDX isomers are in excellent agreement with experimental and recent CCSD-EOM results, respectively. For the two TNT isomers, the ultraviolet RR (UVRR) spectra are similar and in good agreement with recently measured experimental results. Additionally, the UVRR spectra computed using the excited-state and CPP approaches compare favorably with the VB theory results. On the other hand, the RR spectra of the RDX conformers differ from one another, reflecting the importance of the positioning of the NO2 groups with respect to the ring. In the gas phase or in solution, RDX would give a spectrum associated with a conformationally averaged structure. It is encouraging that the computed spectra of the conformers show similarities to recent measured RDX spectra in acetonitrile solution, and reproduce the 10-fold decrease in the absolute Raman cross sections of RDX compared to TNT for the observed 229 nm excitation. We show that in TNT and RDX vibrational bands that couple to NO2 or the ring are particularly resonance enhanced. Finally, the computed RDX spectra of the conformers present a benchmark for understanding the RR spectra of the solid-phase polymorphs of RDX.

Density functional theory study of pyrophyllite and M-montmorillonites (M = Li, Na, K, Mg, and Ca): role of dispersion interactions.

The stacking parameters, lattice constants, bond lengths, and bulk moduli of pyrophyllite and montmorillonites (MMTs), with alkali and alkali earth metal ions, are investigated using density functional theory with and without dispersion corrections. For pyrophyllite, it is found that the inclusion of the dispersion corrections significantly improves the agreement of the calculated values of the lattice parameters and bulk modulus with the experimental values. For the MMTs, the calculations predict that the interlayer spacing varies approximately linearly with the cation radius. The inclusion of dispersion corrections leads to sizable shifts of the interlayer spacings to shorter values. In Li-MMT, compaction of the interlayer distance triggers migration of the Li ion into the tetrahedral sheet and close coordination with basal oxygen atoms. Analysis of electron density distributions shows that the isomorphic octahedral Al(3+)/Mg(2+) substitution in MMT causes an increase of electron density on the basal oxygen atoms of the tetrahedral sheets.

Evaluation of theoretical approaches for describing the interaction of water with linear acenes.

The interaction of a water monomer with a series of linear acenes (benzene, anthracene, pentacene, heptacene, and nonacene) is investigated using a wide range of electronic structure methods, including several "dispersion"-corrected density functional theory (DFT) methods, several variants of the random phase approximation (RPA), DFT-based symmetry-adapted perturbation theory with density fitting (DF-DFT-SAPT), MP2, and coupled-cluster methods. The DF-DFT-SAPT calculations are used to monitor the evolution of the electrostatics, exchange-repulsion, induction, and dispersion contributions to the interaction energies with increasing acene size and also provide the benchmark data against which the other methods are assessed.

[Annular lipoatrophy of the ankles]. / Lipoatrophie annulaire des chevilles.

BACKGROUND: Annular lipoatrophy of the ankles (ALA) is an extremely rare form of localized lipoatrophy characterized by atrophy of subcutaneous fat. We report a case of annular atrophy of the ankles associated with a history of diabetes and Graves' disease. PATIENTS AND METHODS: A 22-year-old woman with a history of Graves' disease and diabetes consulted for annular lesions of ankles which had appeared three years earlier. She had suddenly developed erythematous annular plaques on the right ankle. One week later, the plaques had evolved towards progressive atrophic bands involving the lower third of the legs. The overlying skin was normal and muscle involvement was absent. Laboratory studies revealed an antinuclear antibody (ANA) titre of 1/640 while a skin biopsy specimen showed diffuse lobular lymphohistiocytic panniculitis rich in lymphocytes and lipophages foam cells without any evidence of vasculitis. A direct immunofluorescence microscopy study was negative. Lipoatrophy was still present after six months of chloroquine treatment (300mg per day). DISCUSSION: ALA is a rare and poorly understood condition. Based on the ten or so case reports in the literature, we attempted to define the clinical and histological profile of the disease as well as its course and its relationship with other forms of atrophic panniculitis. In particular, the onset of LAC in our patient presenting several autoimmune diseases underlines its close relationship to the condition described as "connective tissue panniculitis".

Assessment of the performance of common density functional methods for describing the interaction energies of (H2O)6 clusters.

Localized molecular orbital energy decomposition analysis and symmetry-adapted perturbation theory (SAPT) calculations are used to analyze the two- and three-body interaction energies of four low-energy isomers of (H(2)O)(6) in order to gain insight into the performance of several popular density functionals for describing the electrostatic, exchange-repulsion, induction, and short-range dispersion interactions between water molecules. The energy decomposition analyses indicate that all density functionals considered significantly overestimate the contributions of charge transfer to the interaction energies. Moreover, in contrast to some studies that state that density functional theory (DFT) does not include dispersion interactions, we adopt a broader definition and conclude that for (H(2)O)(6) the short-range dispersion interactions recovered in the DFT calculations account about 75% or more of the net (short-range plus long-range) dispersion energies obtained from the SAPT calculations.

[Acute generalized exanthematous pustulosis following a spider bite: three cases from Tunisia]. / Pustulose exanthématique aiguë généralisée succédant à une morsure d'araignée : trois observations tunisiennes.

BACKGROUND: acute generalized exanthematous pustulosis (AGEP) is a severe eruption induced in most cases by medication; more rarely, it is associated with viral infection, food allergens or toxins. The literature contains only very rare reports of AGEP caused by a spider bite. We describe three cases of AGEP in Tunisian women following a spider bite. CASE REPORTS: three Tunisian women were hospitalized in the dermatology department during the summer months presenting acute febrile pustulosis and rash occurring after a spider bite. The diagnosis of AGEP was confirmed with certainty based on the EuroSCAR score. Two patients presented marked eosinophilia. The outcome was favourable in all cases after symptomatic treatment. DISCUSSION: the factors militating in favour of spider-bite origin in these three patients were: (1) the presence of skin lesions characteristic of a spider bite; (2) the chronology of events, with eruption occurring 24 to 48 hours after the bite; and (3) the exclusion of the common causes of AGEP and the presence of marked eosinophilia in two of the cases. CONCLUSION: Our cases and the few cases published in the literature indicate that spider bites may be added to the list of the possible causes of AGEP.

Lymphatic spread in an immunocompetent adult.

Cutaneous tuberculosis with lymphatic spread is rarely described. We report the case of a woman aged 38, immunocompetent, working in a fruit sorting center, who consulted us for ulceration of the left third finger that had persisted for four months, following a prick from a prickly pear. Physical examination revealed a nodular, erythematous, and ulcerative lesion of the left third finger, associated with inflammatory subcutaneous nodules arranged in a line along the ipsilateral upper extremity and an ipsilateral axillary lymph node. Laboratory tests and chest X-ray were normal. Pathological examination revealed granulomatous chronic inflammation without necrosis. PCR detected DNA from Mycobacterium tuberculosis. No extracutaneous tuberculosis locations were detected. A tuberculous chancre by direct inoculation was therefore diagnosed. The patient received quadruple therapy (rifampicin + isoniazid + pyrazinamide + ethambutol) for 2 months, followed by a combination therapy based on isoniazid and rifampicin for 6 months. Marked regression of the cutaneous lesions occurred after 1 month of first-line therapy. A tuberculous chancre is a rare form of cutaneous tuberculosis, with possible lymphatic spread, in immunocompromised patients but also in immunocompetent children and young adults.

Variational and diffusion Monte Carlo study of post-d group 13-17 elements.

We present ab initio calculations of atomic and molecular systems containing the first-, second-, and third-row post-d elements (Ga-Br, In-I, and Tl-At) using several methods including variational and diffusion Monte Carlo. In the quantum Monte Carlo calculations, we used the recent scalar-relativistic energy-consistent Hartree-Fock pseudopotentials [M. Burkatzki et al., J. Chem. Phys. 126, 234105 (2007)], which are nonsingular at the origin. For the first- and second-row elements, the calculated ionization energies and electron affinities are in excellent agreement with those obtained using CCSD(T) with large basis sets and with experiment after correcting approximately for spin-orbit effects. For the third-row elements, where relativistic effects cannot be adequately included by a simple j-averaging, the results are in excellent agreement with CCSD(T) energies obtained with a large (5-zeta) basis set. Benchmark calculations of the dissociation energies, vibration frequencies, and equilibrium bond lengths of several diatomic molecules including As(2), Br(2), Sb(2), and I(2) as well as the hydrides XH (X = Ga, Br, In, I, and At) are presented.

[Chronic vulvar lymphedema revealing Crohn disease in a teenage girl]. / Lymphœdème vulvaire chronique révélant une maladie de Crohn.

INTRODUCTION: Cutaneous Crohn disease is a rare cutaneous manifestation of Crohn disease in children. Herein is reported a case of persistent vulvar lymphedema revealing Crohn disease in a teenage girl. CASE REPORT: A 14-year-old girl presented with an 8-month history of persistent vulvar swelling associated with chronic macrocheilia. Dermatologic examination showed an inflammatory vulvar lymphedema, associated with perianal fissures and hypertrophic gingivitis. Vulvar skin biopsy revealed non-necrotizing granulomatous inflammation. Gastrointestinal endoscopy yielded no significant findings. The diagnosis of Crohn disease presenting as vulvar lymphedema was established. Oral metronidazole therapy resulted in partial improvement of cutaneous lesions beginning the 1st week. CONCLUSION: The originality of this case lies in the presentation of chronic macrocheilia with persistent vulvar lymphedema in a child, revealing Crohn disease without gastrointestinal involvement.