[Fatal outcome in a patient coinfected by malaria and HIV]. / Issue fatale chez un patient coinfecté par le VIH et la malaria.

Imported malaria is a pathology mainly due to Plasmodium falciparum. For patients with co- morbidities, such as HIV or believing themselves immune, the risk of malaria is more severe. We present the case of a HIV patient carrier with a cerebral malaria of letal evolution despite a rapid decline in its parasitaemia using Artesunate. This case describes the relationship HIV-malaria, stresses the place of Artesunate, and insist on the importance of preventive measures for malaria acquisition for any person with HIV traveling to endemic areas.

La malaria importée est une pathologie due principalement au Plasmodium falciparum. Pour les patients porteurs de comorbidités comme le VIH ou se croyant immunisés, le risque de malaria est plus sévère. Nous présentons le cas d'un patient porteur du VIH avec une malaria cérébrale d'évolution mortelle, malgré une diminution rapide de sa parasitémie grâce à l'utilisation d'Artesunate. Ce cas décrit les relations VIH- malaria, souligne la place de l'Artesunate, et insiste sur l'importance des mesures de prévention d'acquisition de la malaria auprès de toute personne VIH voyageant vers les zones endémiques.

Antiphase domain tailoring for combination of modal and 4¯ -quasi-phase matching in gallium phosphide microdisks.

We propose a novel phase-matching scheme in GaP whispering-gallery-mode microdisks grown on Si substrate combining modal and 4¯ -quasi-phase-matching for second-harmonic-generation. The technique consists in unlocking parity-forbidden processes by tailoring the antiphase domain distribution in the GaP layer. Our proposal can be used to overcome the limitations of form birefringence phase-matching and 4¯ -quasi-phase-matching using high order whispering-gallery-modes. The high frequency conversion efficiency of this new scheme demonstrates the competitiveness of nonlinear photonic devices monolithically integrated on silicon.

Millisecond Photon Lifetime in a Slow-Light Microcavity.

Optical microcavities with ultralong photon storage times are of central importance for integrated nanophotonics. To date, record quality (Q) factors up to 10^{11} have been measured in millimetric-size single-crystal whispering-gallery-mode (WGM) resonators, and 10^{10} in silica or glass microresonators. We show that, by introducing slow-light effects in an active WGM microresonator, it is possible to enhance the photon lifetime by several orders of magnitude, thus circumventing both fabrication imperfections and residual absorption. The slow-light effect is obtained from coherent population oscillations in an erbium-doped fluoride glass microsphere, producing strong dispersion of the WGM (group index n_{g}∼10^{6}). As a result, a photon lifetime up to 2.5 ms at room temperature has been measured, corresponding to a Q factor of 3×10^{12} at 1530 nm. This system could yield a new type of optical memory microarray with ultralong storage times.

Controling the coupling properties of active ultrahigh-Q WGM microcavities from undercoupling to selective amplification.

Ultrahigh-quality (Q) factor microresonators have a lot of applications in the photonics domain ranging from low-threshold nonlinear optics to integrated optical sensors. Glass-based whispering gallery mode (WGM) microresonators are easy to produce by melting techniques, however they suffer from surface contamination which limits their long-term quality factor to a few 10(8). Here we show that an optical gain provided by erbium ions can compensate for residual losses. Moreover it is possible to control the coupling regime of an ultrahigh Q-factor three port microresonator from undercoupling to spectral selective amplification by changing the pumping rate. The optical characterization method is based on frequency-swept cavity-ring-down-spectroscopy. This method allows the transmission and dispersive properties of perfectly transparent microresonators and intrinsic finesses up to 4.0 × 10(7) to be measured. Finally we characterize a critically coupled fluoride glass WGM microresonator with a diameter of 220 µm and a loaded Q-factor of 5.3 × 10(9) is demonstrated.

Acute paralysis after seafood ingestion.

The first European case of tetrodotoxin intoxication is reported in a patient who ingested a trumpet shellfish from the Atlantic Ocean in Southern Europe. He suffered general acute paralysis with respiratory failure necessitating ventilation. Early neurophysiologic studies showed complete peripheral nerve inexcitability, with no recordable sensory or motor responses, and normal electroencephalography. Tetrodotoxin was detected in high quantities in the patient's blood and urine through high performance liquid chromatography-mass spectrometry analysis. Seventy-two hours after admission the patient recovered normal strength, reflexes and sensation.

High-gain wavelength-selective amplification and cavity ring down spectroscopy in a fluoride glass erbium-doped microsphere.

We experimentally demonstrate a compact optical amplifier consisting of a rare-earth-doped whispering-gallery-mode microsphere coupled via a tapered fiber. A gain up to 20 dB is reported in an erbium-doped fluoride glass microsphere 135 µm in diameter. Below the amplification regime, the optical gain is used to compensate for unavoidable losses due to surface contamination or scattering. Quality factor as high as 2×10(9) has been measured by analyzing the transient response of the microsphere excited by a dynamically shifted frequency input signal.

Haemoperitoneum associated with cocaine abuse: a case report.

Cocaine use is now relatively common in the occidental societies and is responsible for a long list of medical complications involving almost every organ system in the body. The digestive complications are less known. We report a case of a young man who presented to the emergency department with violent abdominal pain and several episodes of vomiting after using intranasal cocaine. The abdominal pain was caused by a massive haemoperitoneum with no evidence of any underlying pathology. This case shows that we have to consider the possibility of a lethal abdominal haemorrhage in the differential diagnosis of acute abdominal pain in cocaine abusers.

Simple method to obtain symmetry harmonics of point groups.

We propose a simple, self-consistent method to obtain basis functions of irreducible representations of a finite point group. Our method is based on eigenproblem formulation of a projection operator represented as a nonhomogeneous polynomial of angular momentum L. The method is shown to be more efficient than the usual numerical methods when applied to the analysis of high-order symmetry harmonics in cubic and icosahedral groups. For low-order symmetry harmonics the method provides rational coefficients of expansion in the Y(L,M) basis.

[Verrucous carcinoma of the esophagus. A case report]. / Su di un caso di carcinoma verrucoso dell'esofago.

Verrucous carcinoma (VC) of the esophagus is a rare variant of squamous cell carcinoma and only 20 cases have so far been reported in the international literature. The neoplasm is usually highly differentiated, presents a slow growth pattern with invasion of surrounding organs rather than blood-borne metastases. Recently, a causative role of human papillomavirus (HPV) has been hypothesized. The case of a patient affected with locally advanced VC of the esophagus and treated by means of local antiviral therapy is reported. A 41-year-old male patient was admitted to our institution for persistent atypical thoracic pain. The imaging techniques (thoracic and abdominal CT scans; upper GI endoscopy; hydrosoluble contrast swallow; endoscopic US) revealed a cauliflower-like protruding esophageal mass, active mucosal mycosis, multiple ulcerations of the distal esophagus, as well as 2 broncho-esophageal fistulas. The neoplasm extended beyond the esophageal wall, infiltrating surrounding cervical and mediastinal organs and the patient presented with secondary esophageal achalasia and right bilobar pneumonia. The histologic specimen was consistent with VC of the esophagus and the presence of HPV infection was detected by means of qualitative PCR assay. The patient was deemed not fit for surgery and a local antiviral treatment with hydroxy-phosphonyl-methoxypropyl-cytosine 5 mg/kg a week was started. After initial response to treatment, the patient presented with sudden progression leading to further broncho-esophageal fistula treated with endoscopic stent placement and ultimate death 6 months after referral to our center. In keeping with international data, our case confirms that esophageal VC has a highly unfavorable outcome, despite its high degree of differentiation and slow growth pattern. The long natural history, the lack of specific symptoms and the presence of coexisting esophageal diseases delay the diagnosis and account for the local advancement of this malignancy. Surgery is the option of choice for early stage lesions and advanced VC does not seem to benefit from current chemotherapeutic regimens. The causative role of HPV and the advancements of molecular pharmacology might allow for effective treatment in high-risk patients.

[Multidisciplinary approach of hepatic metastasis of colorectal origin]. / Approche multidisciplinaire des métastases hépatiques d'origine colorectale.

Surgery remains the only potentially curative treatment for liver metastases. After margin free resection, approximately 30% of the patients present long-term survival. Due to the metastases number and/or volume, only 10 to 15% of the patients are candidates for curative-intent surgery. Thus, the objectives of the diagnostic and therapeutic management are to select adequately the patients for surgery and to improve resection rate by the use of neoadjuvants methods. Positron emission tomography could improve the preoperative detection of hepatic and extrahepatic metastases leading to the exclusion of some patients from useless surgical exploration. For patients with initially resectable tumors, no benefit has been demonstrated for adjuvant chemotherapy. For non resectable metastases, two neoadjuvants methods should be evaluated, chemotherapy to reduce tumor volume and portal vein embolization of the tumor side to improve the hepatic functional reserve and allow larger resection. For non-accessible lesion, selective tumor destruction using radiofrequency offers promising perspectives. In conclusion, the multiplication of the diagnostic and therapeutic methods certainly improve the global management of patients with liver metastases but also makes more difficult the individual choice for the best treatment. For this reason, a multimodal approach is absolutely mandatory.

Whispering-gallery-mode laser at 1.56 mum excited by a fiber taper.

We report the observation of whispering-gallery-mode lasers based on Er(3+) -doped ZBLAN microspheres coupled with half-tapered and tapered optical fibers. A multimode lasing effect is observed at 1.56mu when the taper diameters are properly adjusted so that their fundamental propagation constants match those of the resonant modes of interest. Overlap between the pump and the laser geometrical modes is optimized by pumping at 1.48mu .

TEM-24 extended-spectrum beta-lactamase-producing Enterobacter aerogenes: long-term clonal dissemination in French hospitals.

OBJECTIVE: To investigate interstrain relatedness of TEM-24-producing Enterobacter aerogenes clinical strains isolated between 1993 and 1998 in 10 French hospitals from nine areas by pulsed-field gel electrophoresis (PFGE) and plasmid patterns. METHODS: Fifteen TEM-24-producing strains and a set of 16 control strains having various other antibiotic resistance phenotypes were genotyped by PFGE. Plasmid DNA from TEM-24-producing strains and transconjugants was analyzed. RESULTS: Analysis of XbaI macrorestriction patterns revealed only minor variations, and showed that all 15 TEM-24-producing strains were closely related. Some isolates originating from distant areas had indistinguishable patterns. According to their clustering correlation coefficients, they were also genomically distant from the control strains. Two plasmid patterns were observed in TEM-24-producing strains, one of them in 13 of the strains. Large plasmids of 85 kb encoding TEM-24 beta-lactamase were present in all isolates and, in all except one strain, could be transferred with high frequency by conjugation. CONCLUSIONS: These results confirm that the spread of the TEM-24 extended-spectrum beta-lactamase in France was essentially due to the dissemination of a single clone.