Unlocking the observation of different proton populations in fluorinated polymers by solid-state 1H and 19F double resonance NMR spectroscopy.

Nafion proton exchange membranes (PEMs) for fuel cell applications are extensively studied and commercially applied, but their unique proton conduction capabilities are still somewhat unexplained. For studying proton dynamics in situ, molecular level spectroscopic techniques have been of limited utility so far. By solid-state 1H and 19F double resonance nuclear magnetic resonance (NMR) spectroscopy using the recently revived multiple contact cross-polarization (MC-CP) pulse sequence along with double-quantum 1H-1H filtering, high resolution proton populations distinct from the dominant water resonance were observed in Nafion for the first time. This methodology quenches signal decay due to spin-lattice relaxation in the rotating frame and enables magnetization transfer between the relatively mobile 1H and 19F spin baths in Nafion. Further studies of these previously unrevealed proton populations will lead to a better understanding of the Nafion proton conduction mechanism and proton exchange processes in general.

Distinct pattern of TP53 mutations in squamous cell carcinoma of the esophagus in Iran.

Extremely high rates of squamous cell carcinoma of the esophagus (SCCE) are observed in Iran, reflecting unknown, genetic and/or epidemiological risk factors. Among genetic alterations in SCCE, TP53 mutations are the most frequent, vary among populations, and may provide clues on etiological mechanisms. We have analysed mutations in TP53 (exons 5-8) in 98 SCCE from Iran by temporal temperature gel electrophoresis and direct sequencing. We found 58 mutations in 49 patients (50%), with a high prevalence of C to T transitions at CpG dinucleotides (29.3%). The TP53 mutation pattern in Iran was significantly different from that observed in SCCEs from high incidence areas of China and Western Europe (P=0.007). Moreover, the prevalence of mutations at A : T base pairs (transitions and transversions) was higher in men than in women (38.7% vs 11.1%, P=0.033). COX-2 overexpression was detected in 69% of the cases evaluated (24/35), without significant association with TP53 mutation. Accumulation of nitrotyrosine, a marker of protein damage by excess levels of nitric oxide, was observed in tumor cells in six of 18 [corrected] cases analysed. These results are consistent with the hypothesis that several factors are involved in TP53 mutagenesis in Iran. These factors include a baseline of chronic inflammatory stress, which may have a multiplicative impact on the sensitivity of esophageal cells to exogenous factors of risk.

Functionalization of Zr-based MOFs with alkyl and perfluoroalkyl groups: the effect on the water sorption behavior.

Stability and sorption of Metal-Organic Frameworks (MOFs) towards water are critical in many applications, and can a priori be modulated through the introduction of suitable organic functional groups on their backbone. We report here the preparation of a series of Zr(iv)-based MOFs functionalized with alkyl and perfluoroalkyl groups and their characterization by X-ray powder diffraction, multi-nuclei ((1)H, (13)C, (19)F) solid state nuclear magnetic resonance analyses, and nitrogen sorption measurements at 77 K. Their water sorption behavior was evaluated at 298 K and related to their physico-chemical features, highlighting both the effect of the confinement and the nature of the functional groups on the hydrophilic/hydrophobic balance.

Endothoracic endoesophageal pull-through operation. A new approach to cancers of the esophagus and proximal stomach.

Many thoracic surgeons have expressed concern about the complications inherent in transhiatal esophagectomy without thoracotomy. The technique of endothoracic endoesophageal pull-through uses a mucosal coring of normal esophagus beyond the tumor and leaves a muscular tube through which the substitute organ is passed. Mediastinal hemorrhage, tracheal injury, and chylothorax are eliminated.

Intraoperative bronchial aspiration of ruptured pulmonary hydatid cysts.

Ruptured pulmonary hydatid cysts are seen clinically and radiologically as persistent cavitary lesions of the lung. Bronchi opening into the pericyst cavity allow for discharge of fluid matter but not the escape of solid remnants of the collapsed parasite. Operative manipulation of the involved lung in the course of surgical management of chronic ruptured pulmonary hydatids can force fragments of the laminated membrane or small daughter cysts into the bronchial tree. Such extruded solid fragments lodge in bronchi of the same or opposite lung with resulting acute obstruction of airways. Intraoperative bronchial aspiration of hydatid material was seen in 7 patients with ruptured hydatid cysts of the lung, either primary or secondary to transdiaphragmatic extension of liver hydatids. The first clinical sign can be unexplained difficulty in ventilation. Effective management consists of prompt exposure of the stem bronchus on the operative side, with bronchotomy for suction retrieval of escaped solid fragments of the parasite.

A new approach to the palliation of advanced proximal gastric cancer.

BACKGROUND: The operative mortality and morbidity rates of palliative total gastrectomy can be high, and survival is not extended. The quality of a foreshortened life is often marred by distressing postprandial symptoms and relentless weight loss. These problems can be attributed to the conventional manner of reconstruction after total gastrectomy, with small-bowel gastric reservoirs restricting the amount of caloric intake. Large-bowel gastric reservoirs have greater capacity and empty well if positioned upright within the chest for proper emptying. The scope of a combined palliative total gastrectomy, esophagectomy, and colon pull-through must be kept within the limits of patient tolerance. STUDY DESIGN: A palliative total gastrectomy was performed in 70 patients with incurably advanced cancers of the proximal and middle third of the stomach (TNM stages: II, 4%; III, 26%; and IV, 70%) using the large-bowel as a gastric substitute. The trauma of reconstruction by colon pull-through was lowered by avoiding thoracotomy and by positioning the colon within the lumen of the deepithelialized esophagus. Proximal cervical esophagocolostomy, distal duodenocolostomy, and colocolostomy reestablished gastrointestinal continuity. Follow-up focused on subjective gastrointestinal symptoms and nutritional maintenance. RESULTS: The operative mortality rate was 10%, postoperative complications were not inordinately high, and autopsy findings showed no defects in the technique of reconstruction. The normal esophageal mucosa was readily cored out through the neck and the abdomen, and the remaining esophageal muscular tunnel accommodated the pulled-through segment of colon. Quantitative assessment of postoperative quality of life proved impractical, but none of 58 longterm survivors (mean of 17.1 months for combined TNM stages II, III, and IV) suffered from disabling symptoms or pronounced weight loss. The quality of life, but not its length, appeared distinctly improved. CONCLUSIONS: The frequently encountered problems of abdominal distress and weight loss after palliative total gastrectomy can be averted by safely positioning a colonic gastric substitute within the lumen of the normal esophagus from which the mucosal lining has been extracted.

Esophageal exfoliative cytology samplers. A comparison of three types.

OBJECTIVE: To compare three types of esophageal exfoliative cytology samplers in terms of patient acceptability, ease of use, final destination of the sampler tip in the gastrointestinal tract and cellular yield. STUDY DESIGN: A controlled, single-blind, cross-over study was undertaken to compare the balloon, sponge and sponge-mesh samplers in healthy volunteers. After completing the three procedures in random order, participants were asked about their preferred method. Ease of use was defined as the technician's ability to perform the intubation successfully. Final destination of the samplers was assessed fluoroscopically. Cytopathologists determined the cellular yield of each sampler using the Bethesda System. RESULTS: Sixty-two volunteers participated. The two encapsulated samplers were significantly preferred over the balloon (P < .0001). There was no significant difference in ease of use, final destination or cellular yield of the three techniques. All three samplers were successfully intubated on the first attempt and retrieved adequate numbers of squamous and glandular cells in > 78% of cases. CONCLUSION: All three samplers obtained satisfactory yields of squamous and glandular cells, but the encapsulated samplers were more patient acceptable. The sponge-mesh sampler may be the least complicated sampler for field screening use. Larger-scale studies will be required to test the accuracy of these three samplers for detecting esophageal dysplasia and carcinoma.

A new approach to the surgical treatment of hydatid cyst.

Hydatid cysts of soft-tissue organs occur in five forms: univesicular, multivesicular, calcified (aborted), ruptured (into adjacent body cavities or host organ ducts), and infected. Each of these distinct forms requires an appropriate surgical approach. For uni- or multivesicular cysts uncontrolled spillage of fertile elements of the parasite is a major hazard. A new method using local freezing of the cyst's outer layer and 0.5% silver nitrate as a scolicidal agent effectively overcomes this problem. Calcified cysts can be left alone. Suppuration or rupture into adjacent body cavities or internal organ channels must be handled according to basic surgical principles and all of the parasitic material removed.

[Role of thoracic radiography in the management of community-acquired pneumonia]. / Place de la radiographie de thorax pour la prise en charge des pneumonies communautaires.

In patients presenting with a lower respiratory tract infection, it is generally recommended to order a chest X-ray in two circumstances: when the clinical signs suggest the diagnosis of pneumonia or in case of rather atypical symptoms suggesting a potential risk of complications. Indeed, the presence of one or more recent opacities, and more specifically, homogeneous alveolar infiltration(s) remains the gold standard criterion for the diagnosis of pneumonia. One must not however let this rule overshadow certain limitations of the chest X-ray reported in the literature: 1. the misdiagnosis of certain cases of pneumonia or bronchopneumonia seen early; 2. the extent of the infiltration gives only a very relative assessment of severity; 3. the characteristics of the infiltration are only relatively specific for etiological diagnosis. In patients with community acquired pneumonia diagnosed on the basis of clinical signs and radiographic findings, systematically performed series of follow-up X-rays have shown that the initial extension of the infiltration and the rate of its resolution contribute quite variably to the diagnosis of complications. The best indication for ordering a follow-up X-ray before 6 weeks remains an unfavorable clinical course.

[Acute respiratory distress in a patient with sickle-cell anemia]. / Détresse respiratoire aiguë chez une patiente drépanocytaire.

The acute chest syndrome is a frequent complications of sickle-cell disease characterized by chest pain, fever, and new infiltrate on chest x-ray image. Pathophysiologic factors appear to be multifactorial and better known. We report the case of a 28-year-old woman with homozygous sickle cell anemia who developed acute chest syndrome probably secondary to fat embolism.

[Bronchopulmonary disease in drug abusers]. / La pathologie bronchopulmonaire des toxicomanes.

Drug abuse is a growing problem in industrialized countries, opening the way to new diseases of the respiratory tract. It has been demonstrated that regular inhalation of cannabis has the same consequences as tobacco smoking. The same cannot be said for other drugs. Cocaine, amphetamines or crack expose the patient to particular toxic effects: in addition to barotrauma related to the administration route, syndromes of acute respiratory distress have been described. These result either from bronchial reactions, asthma exacerbation or eosinophil bronchopneumonia, or alveolar involvement: intra-alveolar bleeding, pulmonary edema or organized pneumonia. Respiratory complications induced by opiates, often used in injections, are related to central alveolar hypoventilation and/or the development of injury from pulmonary edema or pneumonia. The pathophysiology of these lesions is not perfectly understood. Besides these specific conditions, infection is a major problem in drug abusers, irrespective of the drug: bacterial pneumonia, tuberculosis, HIV infection are much more frequent in this high-risk group. Finally repeated intravenous injections of various drugs designed for oral intake can lead to severe complications such as pulmonary hypertension or toxic interstitial lung disease. Summarizing, respiratory diseases in drug abuses can take on a wide range of quite complex presentations. Occasional or regular use of illicit drugs can lead, not exceptionally, to severe respiratory complications requiring rapid management. Knowledge of the principal complications and the appropriate diagnostic procedures is indispensable.

[Bacteremia and Pasteurella multocida pneumonia revealing HIV infection]. / Bactériémie et pneumopathie à Pasteurella multocida révélant une infection à VIH.

Pasteurella multocida is a major pathogen in local wound infections due to animal bites. Pneumonia and bacteremia are less frequent and usually associated with local or general impairment of host defenses. Scarce reports exist about Pasteurella multocida infections in HIV infected patients. We report here a case of hypoxemic pneumonia and bacteremia due to Pasteurella multocida revealing an HIV infection in a young man.

[Computed tomographic diagnosis of a fortuitously discovered opacity]. / Diagnostic tomodensitométrique d'une opacité de découverte fortuite.

We report a case of pleuroparietal lipoma discovered fortuitously. Despite the small size, the diagnosis was obtained with computed tomography using a rigorous protocol demonstrating a negative density corresponding to fat tissue. A series of slices sufficiently thin to avoid a partial volume effect was required to obtain reliable measurements. In case of doubt, magnetic resonance imaging would be indicated.

[Lemierre's syndrome: a case report]. / Le syndrome de Lemierre: a propos d'une observation.

We report a case of Lemierre's syndrome with a pleuropulmonary complication. Lemierre's syndrome is a rare etiology of lung abscess. The diagnosis is clinical and microbiological (anaerobic organisms). This syndrome associates an acute oropharyngeal infection with septic thrombophlebitis of the internal jugular vein (sometimes many days before the lung lesion) and pulmonary abscess formation. Clinicians should be aware of this syndrome that is fatal in 10% of patients, usually after delayed or missed diagnosis. The frequency of Lemierre's syndrome would be higher if antibiotics were given only to pharyngitis patients positive for streptococcus.

[Moderately abundant hemoptysis revealing endobronchial hamartochondroma]. / Une hémoptysie de moyenne abondance révélant un hamartochondrome endobronchique.

Hemoptysis is rarely the inaugural sign of endobronchial hamartoma. Abundance may range from moderate to massive, and may be life-threatening. We report the case of a 44-year-old woman who was referred to our center with moderate and persistent hemoptysis. A left upper lobe lobectomy was performed. We discuss the therapeutic options in such cases.

[Postpneumonectomy pulmonary edema. Review of the literature. Apropos of 2 new cases]. / Cedème pulmonaire postpneumonectomie. Revue de la littérature. A propos de deux nouveaux cas.

Postpneumonectomy pulmonary edema is a poorly understood clinical entity. We report two new cases and review the literature. The main manifestations are increased pulmonary perfusion flow, endothelial damage, and amputation of the lymphatic system. Treatment depends on the physiological situation of the lung remaining after pneumonectomy. Prevention requires co-operation between the medical and surgical teams.

[Yellow nail syndrome. Three cases]. / Le syndrome des ongles jaunes. A propos de trois observations.

Yellow nail syndrome is an uncommon diagnosis established on the basis of clinical presentation with slow-growing yellow discolored nails, lymphedema, and pulmonary manifestations. We report 3 new cases with their pulmonary component.

Optical anisotropy in self-assembled InAs nanostructures grown on GaAs high index substrate.

We present a study of the optical properties of InAs self-assembled nanostructures grown by molecular beam epitaxy on GaAs(11N)A substrates (N = 3-5). Photoluminescence (PL) measurements revealed good optical properties of InAs quantum dots (QDs) grown on GaAs(115)A compared to those grown on GaAs(113)A and (114)A orientations substrate. An additional peak localized at 1.39 eV has been shown on PL spectra of both GaAs(114)A and (113)A samples. This peak persists even at lower power density. Supporting on the polarized photoluminescence characterization, we have attributed this additional peak to the quantum strings (QSTs) emission. A theoretical study based on the resolution of the three dimensional Schrödinger equation, using the finite element method, including strain and piezoelectric-field effect was adopted to distinguish the observed photoluminescence emission peaks. The mechanism of QDs and QSTs formation on such a high index GaAs substrates was explained in terms of piezoelectric driven atoms and the equilibrium surfaces at edges.