Interferometric near-field characterization of plasmonic slot waveguides in single- and poly-crystalline gold films.

Single-crystalline gold films show superior plasmonic properties compared to their poly-crystalline counterparts. However, this advantage comes at the cost of a more complex preparation process. It is thus crucial to validate whether the impact of the material quality on the performance of the respective plasmonic device justifies this additional effort. In order to address this question for the case of plasmonic slot waveguides, we present interferometric near-field measurements at telecommunication wavelengths on slot waveguides in single- and poly-crystalline gold films. We observe significantly larger propagation lengths in the case of single-crystalline gold films for slot widths below 100 nm. In contrast for larger widths, both gold films give rise to comparable propagation lengths.

Freestanding metasurfaces for optical frequencies.

We present freestanding metasurfaces operating at optical frequencies with a total thickness of only 40 nm. The metasurfaces are fabricated by focused ion beam milling of nanovoids in a carbon film followed by thermal evaporation of gold and plasma ashing of the carbon film. As a first example, we demonstrate a metasurface lens based on resonant V-shaped nanovoids with a focal length of 1 mm. The second example is a metasurface phase plate consisting of appropriately oriented rectangular nanovoids that transform a Gaussian input beam into a Laguerre-Gaussian LG-1,0 mode.

Allogeneic bone marrow transplantation for postpolycythemic myeloid metaplasia with myelofibrosis: a case report.

Myeloid metaplasia with myelofibrosis develops in about 10% of patients with polycythemia vera. We report a case of a 48-year-old female with postpolycythemic myelofibrosis successfully treated with allogeneic HLA-matched bone marrow transplantation.

Nosocomial outbreaks due to amikacin-resistant tobramycin-sensitive Acinetobacter species: correlation with amikacin usage.

Fifty-seven patients in the Val-de-Grâce hospital were infected or colonized with amikacin-resistant, tobramycin-sensitive Acinetobacter spp. between January 1985 and December 1987. This resistance phenotype was attributed to the recently described 3'-O-aminoglycoside phosphotransferase (APH(3')-VI), on the basis of substrate profile and DNA-DNA hybridization, and was mainly encountered in various biotypes of A. baumannii isolated from patients. It was also encountered in saprophytic A. johnsonii isolates from the hands of 11 healthy workers among the medical staff, which provided evidence for the dissemination of an epidemic gene among different biotypes and species of Acinetobacter. A retrospective epidemiological survey showed a significant correlation between amikacin consumption and case incidence in the wards where cross-infection had occurred.

[Lymphoma or testicular seminoma: histopathological aspects of the differential diagnosis]. / Lymphome ou séminome testiculaire: aspects histopathologiques du diagnostic différentiel.

Differential diagnosis between seminoma versus primary lymphoma of the testis can be difficult in some observations. Well established data, concerning epidemiological, clinical and radiological findings with histological results allows the right diagnosis to be made in most of cases. Cytological study of tumor prints is always interesting for uncertain cases. Therefore, if doubts persist, immunohistological study, even performed on paraffin embedded material, is the best method.

[MRI aspects of progressive multifocal leukoencephalopathy]. / Aspects IRM de la leucoencéphalopathie multifocale progressive.

Progressive Multifocal Leukoencephalopathy is a demyelinating disease. MRI shows high signal intensity areas on T2w sequence and low intensity aeras on T1w sequence, without enhancement after intravenous contrast injection. The involvement of arcuate fiber (U fibers) creates a sharp border with the cortex. There is no mass effect. Involvement of parieto-occipital areas is frequent. The lesions may be uni or bilateral, single or multiple; bilateral lesions are asymmetric. This typical appearance on MR images occurs in 90% of the patients with PML. Some atypical patterns may occur: focal hemorrhage, atrophy, faint peripheral enhancement and involvement of deep gray matter (basal ganglia). In most cases, the clinical and MR features provide the diagnosis. The main differential diagnosis, in MRI, is HIV-leukoencephalitis, but lesions are diffuse, less intense on T2w sequence and not visible on T1, without involvement of the arcuate fibers. Stereotactic biopsy should be performed only for atypical lesions, particularly in case of predominant involvement of deep gray structures.

[Nephropathy and filariasis from Loa loa. Apropos of 1 case of adverse reaction to a dose of ivermectin]. / Néphropathie et filariose à Loa loa. A propos d'un cas de réaction adverse à la prise d'ivermectine.

A patient with a filarial infection due to Loa loa, received single oral dose of ivermectin A few hours after, he has presented a severe renal impairment. Native of the Cameroons, he was also treated for malaria. A renal biopsy has been done, because of chronic proteinuria. It has showed microfilariae in glomeruli, thickening of the basement membrane and a segmental and focal mesangial hyalinosis. By immunofluorescence microscopy there were granular deposits of IgM and C3 along this membrane. Electron microscopy has showed subepithelial electron- dense deposits. This suggests that the renal disease is immunologically induced. During the therapy, adverse reactions seemed to be related with massive liberation of filarial antigens. This is well known with diethylcarbamazine but also now, sometimes with ivermectin.

[Inflammatory pseudo-tumor of the lung. Clinico-pathologic report of a case]. / Pseudo-tumeur inflammatoire du poumon. Etude anatomo-clinique d'une observation.

One case of a solitary pulmonary nodule occurring in a 54-year-old woman with history of breast carcinoma is presented. Histological examination of the surgical specimen excluded breast carcinoma metastasis and revealed an inflammatory pseudotumor. Principal clinico-pathological findings in previously reported cases are described. Inflammatory pseudotumors may exhibit, as in our case, some nuclear atypia making the diagnosis sometimes difficult with malignancy.

[Tumor of the peripheral nerve sheath with rhabdomyoblastic differentiation arising in a ganglioneuroma: neurilemmoma? A fortuitously detected case]. / Tumeur des gaines des nerfs périphériques à différenciation musculaire survenant sur un ganglioneurome: tumeur de Triton?

An otherwise healthy 21-year-old man with no evidence or family history of Von Recklinghausen's neurofibromatosis presented a posterior mediastinal mass detected on routine chest radiographs. The findings of standard light microscopy, ultrastructural examination and immunohistochemical studies suggested the working hypothesis of an unusual malignant "Triton" tumour: -arising in a pre-existing de novo ganglioneuroma; -fortuitously detected; -predominantly made of multinucleated spindle cells with only ultrastructural and immunohistochemical rhabdomyoblastic differentiation.

[Stereotaxy, MRI and independent computer. 85 punctures]. / Stéréotaxie, IRM et console indépendante. 85 ponctions.

After 150 stereotactic biopsy with CT, the team of Val-de-Grâce has made these ones with MRI and simulation of the complete procedure with an independent computer. The result of 85 biopsies is reported. This one imply the acquisition of 3DFT millimetrics slices, the transfer by Ethernet network on a computer where a specific software treat the data and allow to establish the better course for the needle biopsy. The constraints of quality are very important and some test must be executed. The diagnosis are established, avoiding an unless trepanation.

[Diffuse toxoplasmic encephalitis in a non-immunosuppressed patient]. / Encéphalite toxoplasmique diffuse chez un sujet non immunodéprimé.

Diffuse encephalitic toxoplasmosis is an unusual presentation of toxoplasmosis, in which neuroradiological investigations may not show focal abcesses. Until now it was only reported in immunocompromised patients. In immunocompetent patients, cerebral toxoplasmosis is very unusual, and appears as multiple abcesses, like the classic form in immunocompromised patients. We report the case of an immunocompetent patient who presented a diffuse encephalitic toxoplasmosis; CT and MR examinations showed only nonspecific features of brain swelling and cortical infarct due to vasculitis.

[Progressive multifocal leukoencephalopathy localized in the thalamic grey matter in an AIDS-patient]. / Leuco-encéphalopathie multifocale progressive localisée en substance grise thalamique chez un patient atteint de SIDA.

Involvement of the deep grey matter is unusual in Progressive Multifocal Leukoencephalopathy (PML), which is disease of the white matter. Basal ganglia involvement is usually secondary to extension from lesions of adjacent white matter and easy to recognize. We report a biopsy-proven case of PML in which lesions were mainly thalamic.

[Retrocecal mucus-secreting tumors of the appendix (mucoceles). Apropos of 3 radiologically diagnosed cases]. / Tumeurs mucosécrétantes rétrocaecales de l'appendice (mucocèles). A propos de 3 cas diagnostiqués radiologiquement.

The term of appendiceal mucocele has been applied to a group of lesions distending the lumen of the appendix; filled with mucus. About 15% of these lesions are malignant tumors (cystadenocarcinomas). All these lesions may lead to pseudomyxoma peritonei, but only the peritoneal involvement due to a malignant tumor (adenocarcinoma) has multiple recurrences and poor prognosis. Benign lesions are cured by appendicectomy, even if a peritoneal "gelatinous" effusion is present. These lesions can usually be early diagnosed by US and CT features if the mucocele extends behind the cecum in the retroperitoneal space, especially if the wall is calcified. A colic examination (with barium enema or colonoscopy) must be taken event if the diagnosis is made by US or CT means, because of the significant association of mucocele with other colonic tumors.

[Primary brain lymphoma in AIDS. 17 cases studied by MRI before stereotaxic biopsies]. / Lymphome cérébral primitif du SIDA. 17 cas explorés en IRM avant biopsie stéréotaxique.

AIM: Determining which semiological criteria might help to suggest lymphoma when an intracerebral mass in observed in a patient with AIDS. The use of these criteria might shorten the duration of the anti-toxoplasmic test treatment and to perform puncture earlier. The fast growth of the lymphomas may account for the rapid death of these patients if untreated, but as a corollary, its increase in size can be objectively measured over a short period, about ten days. MEANS: Retrospective study of 17 lymphomas diagnosed with stereotaxic puncture. RESULTS: The most discriminating criteria are ventricular encasement or an original site in the white matter, as well as the moderate character of the edema and of the mass effect relative to the volume of the tumor. Other arguments also help: simple lesion, large size, sinuous contour, no signs of hemorrhage. CONCLUSION: The diagnosis of lymphoma can often be proposed at once. A control must then be performed very soon, with stereotaxic puncture if the volume of the lesion has increased in the meantime.

[Disk highlighting after injection in MRI. Macroscopy and histology of 25 postoperative recurrences]. / Le rehaussement discal après injection en IRM. Macroscopie et histologie de 25 récidives post-opératoires.

400 cases of failed back syndrome were examined with MRI in a prospective study (SE w Rho and T2, SE wT1 before and after injection of paramagnetic contrast agent in axial and sagittal planes). After second time surgery, 70 cases of herniated disks were found. 25 herniated disks were studied in microscopy and results correlated with enhanced herniated disks. Authors describe 4 types of enhancement: veinous plexus (5/24), inflammatory or granulomatous tissue (12/24), degenerative disc with fibrosis (5/24) and osteophytosis (2/24). The criterions of each pattern are described.

[Castleman disease localized in the mesentery]. / Maladie de Castleman localisée au mésentère.

We report a case of Castleman disease in the mesentery localized to a 58 year-old man. The mass is hypervascular on CT, which can suggest the diagnostic before surgery.

[Benign non-parasitic splenic cysts. 9 cases]. / Kystes spléniques bénins non parasitaires. 9 observations.

Benign non-parasitic splenic cysts are uncommon. Their diagnosis can benefit from ultrasounds and computed tomography. However, it may be difficult, before surgery, to distinguish between true cysts, which are congenital with epidermal lining, and false cysts, which are consecutive to a trauma, inflammatory or degenerative, without epidermal lining. We report nine cases of non-parasitic splenic cysts and try to determine the preoperative diagnostic approach. To prevent the overwhelming post-splenectomy infection syndrome, conservative surgical treatment is mandatory. Various surgical methods are discussed.

[Epidemiology of testicular tumors]. / Epidémiologie des tumeurs du testicule.

Testicular tumours are rare tumours affecting young adults (75% of tumours are diagnosed between the ages of 25 and 40 years). The descriptive epidemiological study of the data of the literature reveals a considerable improvement in the prognosis of testicular cancers, particularly since the introduction of cisplatin in the 1980. An epidemiological study conducted on a series of 200 testicular tumours treated at Val-de-Grace military hospital between 1979 and 1989 confirms this improvement with a mortality rate of 7.5% for all stages and histological types combined, with a follow-up of 2 to 12 years.

[Anatomic pathology of testicular tumors]. / Anatomie pathologique des tumeurs du testicule.

Pathological examination of testicular tumours demonstrates the heterogeneity of the histological types encountered. Germ cell tumours, with one or several components, represent 95% of all testicular tumours. The distinction between these various types is always based on morphological criteria, but may also be facilitated by the use of immunolabelling techniques on fixed sections. The local and regional extension and the distinction between seminomatous and non-seminomatous germ cell tumours are important criteria in the subsequent therapeutic strategy. At the present time, there is no consensus concerning the selection of other histoprognostic criteria, which may be observed in the primary tumour it its metastases. Residual masses also have a variable histology and their pathophysiology is sometimes difficult to interpret.

[Ewing's sarcoma and peripheral neuroectodermal tumors. Report of a case with laterothoracic localization]. / Sarcomes d'Ewing et tumeurs neuroectodermiques périphériques. A propos d'un cas de localisation latéro-thoracique.

The authors report the case of a 20-year old male patient presenting with a lateral thoracic tumour which at pathological examination looked like an extra-osseous Ewing's sarcoma. Strongly positive NSE immunolabeling suggested a recently described variant of this lesion: Askin's tumour. In 1979, F. B. Askin described a tumour made of round small cells, located on the side of the thorax and possibly derived from differentiated neuroectodermal tissue. Since that time, the ever wider use of electron microscopy and immunohistochemical methods has made it possible to demonstrate the existence of peripheral neuroectodermal tumours (PNETs) distinct from neuroblastomas. Askin's tumour being only, as it turned out, one of their clinical forms. Following a brief presentation of the clinical, pathological and therapeutic features of PNETs, the authors underline the great similarity between these tumours and Ewing's sarcoma. Owing to the successive discoveries of a cytogenetic abnormality common to these tumour--t(11;22)(q24;q12)--, of a similar expression of proto-oncogens and of identical neuroenzymatic characteristics, Ewing's syndrome can now be regarded as the most undifferentiated of all PNETs, probably arising from the postganglionic neuron of the parasympathetic system.