[High flow oxygen via nasal cannula: Palliative care and ethical considerations]. / Oxygénothérapie nasale à haut débit : soins palliatifs et aspects éthiques.

High flow oxygen via nasal cannula (HFO2NC) has become the first-line reference symptomatic treatment for hypoxemic acute respiratory failure. This non-invasive technique can be addressed, as palliative therapeutic care, to frail patients near end-of-life with a do-not-intubate order. A distinction will be made between those with an imminent and inevitable fatal outcome (pallitative end-of-life management) and those with hope for transient clinical remission (meliorative management). This review focuses on the expected physiological benefits and technical benefits/risks incurred by HFO2NC use in this population. Its main purpose is to highlight the ethical principles governing the palliative management of patients in acute respiratory failure with a do-not-intubate order, and to discuss the various elements to be considered when defining the patient's palliative care plan, in a holistic, individual-centered approach.

Kinetic study of hydrogen lateral diffusion at high temperature in a directly-bonded InP-SiO2/Si substrate.

Hybrid integration of III-V materials onto silicon by direct bonding technique is a mature and promising approaches to develop advanced photonic integrated devices into the silicon photonics platform. In this approach, the III-V material stack is grown on an InP wafer in a unique epitaxial step prior to the direct bonding process onto the silicon-on-insulator wafer. Currently, no additional epitaxial regrowth steps are implemented after bonding. This can be seen as a huge limitation as compared to the III-V on III-V wafer mature technology where multi-regrowth steps are most often implemented. In this work, we have studied the material behavior of an InP membrane on silicon (InPoSi) under epitaxial regrowth conditions by metal-organic vapor phase epitaxy (MOVPE). MOVPE requires high-temperature elevation, typically above 600 °C. We show for the first time the appearance of voids at 400 °C in an InP seed (100 nm) directly-bonded onto a thermally oxidized Si substrate despite the use of a thick SiO2 oxide (200 nm) at the bonding interface. This phenomenon is explained by a weakening of the bonding interface while high-pressurized hydrogen is present. A kinetic study of the hydrogen lateral diffusion is carried out, enabling the assessment of its lateral diffusion length. To overcome the void formation, highly efficient outgassing trenches after bonding are demonstrated. Finally, high-quality AlGaInAs-based multi-quantum well (MQW) heterostructure surrounded by two InP layers was grown by MOVPE on InPoSi template patterned with outgassing trenches. This process is not only compatible with MOVPE regrowth conditions (650 °C under PH3) but also with conventional fabrication processes used for photonic devices.

Spatial gradient in nitrogen deposition affects plant species frequency in acidic grasslands.

Anthropogenic eutrophication impacts ecosystems worldwide. Here, we use a vegetation dataset from semi-natural grasslands on acidic soils sampled along a gradient in north-western Europe to examine the response of species frequency to nitrogen (N) deposition, controlling for the effects of other environmental variables. A second dataset of acidic grasslands from Germany and the Netherlands containing plots from different time periods was analysed to examine whether the results of the spatial gradient approach coincided with temporal changes in the abundance of species. Out of 44 studied species, 16 were affected by N deposition, 12 of them negatively. Soil pH and phosphorus (P) influenced 24 and 14 species, respectively, predominantly positively. Fewer species were related to the soil contents of NO3(-) or NH4(+), with no significant differences between the number of positive and negative effects. Whereas the temporal change of species was unrelated to their responses to pH, species responding negatively to N deposition, soil P and NO3(-) showed a significant decline over time in both countries. Species that were negatively affected by high N deposition and/or high soil P also showed a negative temporal trend and could be characterised by short stature and slow growth. The results confirm the negative role of N deposition for many plant species in semi-natural acidic grasslands. The negative temporal trends of species sensitive to high N deposition and soil P values clearly show a need for maintaining low soil nutrient status and for restoring the formerly infertile conditions in nutrient-enriched grasslands.

Addressing the Impact of Atmospheric Nitrogen Deposition on Western European Grasslands.

There is a growing evidence base demonstrating that atmospheric nitrogen deposition presents a threat to biodiversity and ecosystem function in acid grasslands in Western Europe. Here, we report the findings of a workshop held for European policy makers to assess the perceived importance of reactive nitrogen deposition for grassland conservation, identify areas for policy development in Europe and assess the potential for managing and mitigating the impacts of nitrogen deposition. The importance of nitrogen as a pollutant is already recognized in European legislation, but there is little emphasis in policy on the evaluation of changes in biodiversity due to nitrogen. We assess the potential value of using typical species, as defined in the European Union Habitats Directive, for determining the impact of nitrogen deposition on acid grasslands. Although some species could potentially be used as indicators of nitrogen deposition, many of the typical species do not respond strongly to nitrogen deposition and are unlikely to be useful for identifying impact on an individual site. We also discuss potential mitigation measures and novel ways in which emissions from agriculture could be reduced.

Piezoresistance of top-down suspended Si nanowires.

Measurements of the gauge factor of suspended, top-down silicon nanowires are presented. The nanowires are fabricated with a CMOS compatible process and with doping concentrations ranging from 2 × 10(20) down to 5 × 10(17) cm(-3). The extracted gauge factors are compared with results on identical non-suspended nanowires and with state-of-the-art results. An increase of the gauge factor after suspension is demonstrated. For the low doped nanowires a value of 235 is measured. Particular attention was paid throughout the experiments to distinguishing real resistance change due to strain modulation from resistance fluctuations due to charge trapping. Furthermore, a numerical model correlating surface charge density with the gauge factor is presented. Comparison of the simulations with experimental measurements shows the validity of this approach. These results contribute to a deeper understanding of the piezoresistive effect in Si nanowires.

[Comparison of the individual deprivation index of the French Health Examination Centres and the administrative definition of deprivation]. / Comparaison du score individuel de précarité des centres d'examens de santé, EPICES, à la définition socio- administrative de la précarité.

In French Health Examination Centres, populations in deprived situation were usually defined by administrative criteria The aim of the study was to investigate whether EPICES, a new individual index of deprivation, was more strongly related to health status than an administrative classification. The EPICES score was calculated on the basis of 11 weighted questions related to material and social deprivation. Participants were 197, 389 men and women, aged over 18, encountered in 2002 in French Health Examination Centres. Relationships between health status, health-related behaviours, access to health care, EPICES and the administrative classification of deprivation were analyzed by logistic regression. The associations between EPICES and the study variables were stronger than those observed for the administrative definition. The comparison also showed socially disadvantaged people with poor health identified by the EPICES score who were not by the administrative classification. These results showed that the EPICES score can be a useful tool to improve the identification of deprived people having health problems associated to deprivation.

PCR-RFLP using a SNP on the mitochondrial Lsu-rDNA as an easy method to differentiate Tuber melanosporum (Perigord truffle) and other truffle species in cans.

Canned truffle products labeled Tuber melanosporum, the famous Perigord truffle, may contain other less tasty and cheaper truffle species. To protect consumers from fraud, a PCR DNA-based method was used to unequivocally identify the nature of the product. Several rapid and simple cell lysis procedures, used in conjunction with a commercially available DNA purification kit, were evaluated for their effectiveness in recovering DNA from canned truffle. In parallel, a marker for T. melanosporum was tested on the mitochondrial rDNA. These two techniques were then combined to differentiate T. melanosporum from other truffle species like T. aestivum, T. brumale or T. indicum up to the legal threshold in canned products. These findings not only allow a comparison of the effectiveness of the different DNA extraction methods but also provide a preliminary indication of the specificity and sensitivity of the detection with the mitochondrial marker that might be attainable for truffle species in a quantitative PCR-based analysis method.

Rapid molecular typing of Tuber melanosporum, T. brumale and T. indicum from tree seedlings and canned truffles.

We have developed new DNA extraction and purification procedures for investigation of mycorrhized seedlings and canned truffles. Use of these procedures on approximately 100 mg initial material enabled good sample representation. For mycorrhized seedlings, Taq polymerase inhibitors were discarded irrespective of tree species. In routine analysis we systematically used consensus primers ITS1/ITS4 to check the absence of Taq polymerase inhibitors and the presence of fungus DNA. Positive response with ITS validates other positive or negative PCR results. Absence of amplification with ITS prevents validation of other results. For canned truffles, DNA harvested from ascocarps sterilized for one and a half hours at 115 degrees C was amplified with specific primers. We have developed consensus primers, named R12/F12, to check for the presence of amplifiable fungus DNA and the absence of Taq polymerase inhibitors. Here also, positive response with consensus R12/F12 validates other positive or negative PCR results. We have developed one primer pair specific for T. brumale and another specific for T. melanosporum. We can then characterize these two taxa, which enables the use of "truffle or truffled" French designations. We can also characterize T. indicum, the Asiatic black truffle that might fraudulently be sold as T. melanosporum and T. brumale. These three specific primer pairs were used independently of DNA extraction from tree seedlings or canned truffles. Our process is specific, sensitive, convenient, and quick.

Confidence of academic general internists and family physicians to teach ambulatory procedures.

OBJECTIVE: To evaluate and compare the readiness of academic general internal medicine physicians and academic family medicine physicians to perform and teach 13 common ambulatory procedures. DESIGN: Mailed survey. SETTING: Internal medicine and family medicine residency training programs associated with 35 medical schools in 9 eastern states. PARTICIPANTS: Convenience sample of full-time teaching faculty. MEASUREMENTS AND MAIN RESULTS: A total of 331 general internists and 271 family physicians returned completed questionnaires, with response rates of 57% and 65%, respectively. Academic generalists ranked most of the ambulatory procedures as important for primary care physicians to perform; however, they infrequently performed or taught many of the procedures. Overall, compared with family physicians, general internists performed and taught fewer procedures, received less training, and were less confident in their ability to teach these procedures. Physicians' confidence to teach a procedure was strongly associated with training to perform the procedure and performing or precepting a procedure at least 10 times per year. CONCLUSIONS: Many academic general internists do not perform or precept common adult ambulatory procedures. To ensure that residents have the opportunity to learn routine ambulatory procedures, training programs may need to recruit qualified faculty, train current faculty, or arrange for academic specialists or community physicians to teach these skills.

Confidence of graduating internal medicine residents to perform ambulatory procedures.

OBJECTIVE: To evaluate the training of graduating internal medicine residents to perform 13 common ambulatory procedures, 3 inpatient procedures, and 3 screening examinations. DESIGN: Self-administered descriptive survey. SETTING: Internal medicine training programs associated with 9 medical schools in the eastern United States. PARTICIPANTS: Graduating residents (N = 128); response rate, 60%. MEASUREMENTS AND MAIN RESULTS: The total number of procedures performed during residency, importance for primary care physicians to perform these procedures, confidence to perform these procedures, and helpfulness of rotations for learning procedures were assessed. The majority of residents performed only 2 of 13 outpatient procedures 10 or more times during residency: simple spirometry and minor wound suturing. For all other procedures, the median number performed was 5 or fewer. The percentage of residents attributing high importance to a procedure was significantly greater than the percentage reporting high confidence for 8 of 13 ambulatory procedures; for all inpatient procedures, residents reported significantly higher confidence than importance. Continuity clinic and block ambulatory rotations were not considered helpful for learning ambulatory procedures. CONCLUSIONS: Though residents in this sample considered most ambulatory procedures important for primary care physicians, they performed them infrequently, if at all, during residency and did not consider their continuity clinic experience helpful for learning these skills. Training programs need to address this deficiency by modifying the curriculum to ensure that these skills are taught to residents who anticipate a career in primary care medicine.

Patient preferences for care by general internists and specialists in the ambulatory setting.

OBJECTIVE: To investigate patients' preferences for care by general internists and specialists for common medical conditions. DESIGN: Telephone interview. SETTING: A convenience sample of general internal medicine practices at 10 eastern academic medical centers. PATIENT/PARTICIPANTS: A probability sample of 314 participants who had at least one visit with their primary care physician during the preceding 2 years. MEASUREMENTS AND MAIN RESULTS: Items addressed patients' attitudes concerning continuity of care, preferences for care by general internists or specialists for common medical problems, and perceptions about the competency of general internists and specialists to manage these problems. Continuity was important to participants, with 63% reporting they preferred having one doctor. Respondents were willing to wait 3 or 4 days to see their regular doctor (85%) and wanted their doctor to see them in the emergency department (77%) and monitor their care while in the hospital (94%). A majority (>60%) preferred care from their regular doctor for a variety of new conditions. Though respondents valued continuity, 84% felt it was important to be able to seek medical care from any type of physician without a referral, and 74% responded that if they needed to see a specialist, they were willing to pay out-of-pocket to do so. Although most participants (98%) thought their regular doctor was able to take care of usual medical problems, the majority thought that specialists were better able to care for allergies (79%) and better able to prescribe medications for depression (65%) and low-back pain (72%). CONCLUSIONS: Participants preferred to see their general internist despite their perceptions that specialists were more competent in caring for the conditions we examined. However, they wanted unrestricted access to specialists to supplement care provided by general internists.

Increasing recruitment contacts between generalist residents at the Medical College of Georgia and rural and underserved communities.

To increase the number of residents choosing to practice in rural and underserved areas, the Medical College of Georgia in 1994 created the Office of Recruitment and Retention (ORR) for generalist physicians as part of its participation in The Robert Wood Johnson Foundation's Generalist Physician Initiative. Its major purpose is to increase the contact between generalist residents and practice opportunities, especially those in rural and underserved areas. The office has helped residents better understand the resources available in rural settings and has helped these communities better understand the needs of graduates in generalist residency programs. It became a point of contact for residents and communities. It also organized on-campus "practice opportunity fairs" that permitted community representatives to meet formally with generalist residents to provide information on practice opportunities and community resources. The office organized practice management sessions and provided legal consultation to residents desiring to enter private practice in rural settings. This program has already been instrumental in furthering contact between generalist residents and the rural communities they selected as clinical practice sites during training. Although it is too early to know the impact of these activities, communities increasingly use the office to recruit generalist physicians, and residents use it to identify appropriate practice sites.

Typing Tuber ectomycorrhizae by polymerase chain amplification of the internal transcribed spacer of rDNA and the sequence characterized amplified region markers.

Identification of some economically important Tuber species using classical morphological characteristics is sometimes difficult. We report here the molecular characterization of a species coming from China, Tuber indicum, mistaken with Tuber melanosporum species. Using restriction analysis of the amplified internal transcribed spacer (ITS) of rDNA, ITS sequence analysis, and sequence characterized amplified region markers, with DNA from fruit bodies or mycorrhizae, genetic variation was found between these two species, allowing to differentiate and characterize them.

Development and validation of a scaled questionnaire for evaluation of residency programs.

As residency programs adapt to the need to promote primary care, the importance of quantitating qualitative issues increases. In this study, a questionnaire based on reported residency stressors was answered by 238 internal medicine residents. The Profile of Mood States (POMS) was also completed by 64. Factor analysis derived three scales reflecting emotional distress and satisfaction with the workload and learning environment. Emotional distress correlated positively with POMS scores indicating depression and dejection and was inversely related to workload. Workload satisfaction was significantly higher in programs with fewer admissions and lower in programs with greater patient loads. Responses did not differ by postgraduate year of training. Residents in different programs showed significant differences in emotional distress and workload but not learning environment. Residents in university programs indicated more stress and less satisfaction with workload than those in community programs. This study supports the validity of the three scales and provides insights into elements of the educational process that are difficult to quantitate.

[Guillain-Barré syndrome associated with cytomegalovirus infection after kidney transplantation]. / Syndrome de Guillain-Barré associé à une infection à cytomégalovirus après transplantation rénale.

The Guillain-Barré syndrome associated with cytomegalovirus infection is a recognized entity of unknown pathogenesis. We observed two characteristic cases with acute polyradiculoneuropathy which occurred after renal transplantation. Both patients fulfilled the diagnostic criteria for Guillain-Barré syndrome: tetraparesis with diffuse areflexia and moderate sensorial signs, high protein level in cerebrospinal fluid without cellular reaction, slow or blocked nerve conduction and partial cure after several months delay. In two-thirds of such cases, the syndrome follows an episode of infection. Cytomegalovirus has been recognized as a possible association. The demyelinating polyradiculoneuropathy induced by cytomegalovirus has been reported essentially in immunodepressed patients infected with the human immunodeficiency virus in whom a pathogenic role for cytomegalovirus in peripheral nerves has been suggested. In our two cases, the cytomegalovirus infection occurred before onset of the acute polyradiculoneuropathy. In both cases, specific IgM antibodies and clear IgG positivization occurred before the first signs of neurological impairment even though neither the virus nor specific antibodies could be concomitantly detected in the cerebrospinal fluid. Despite the frequency of cytomegalovirus infections in transplant recipients, to our knowledge, only 9 cases of Guillain-Barré syndrome after transplantation have been reported and the exact mechanism remains to be ascertained. These two cases suggest that the onset of the Guillain-Barré syndrome after renal transplantation was closely related to cytomegalovirus infection. Adequate measures should be taken to quickly diagnose such cases in order to instore rapid treatment for the polyradiculoneuropathy. In addition, this particular situation of post-transplantation onset might help better understand the exact role of cytomegalovirus infection in the Guillain-Barré syndrome.

Holt-Oram syndrome associated with hypoplastic peripheral vasculature and midsystolic click.

Holt-Oram syndrome is a rare, autosomal dominant syndrome characterized by upper extremity skeletal abnormalities and cardiac defects. The most common skeletal anomalies involve the thumbs and range from minor radiographic abnormalities to phocomelia. The most common cardiovascular abnormality is ostium secundum ASD, followed by ventriculo-septal defect and ostium primum ASD. MVP and hypoplastic peripheral vasculature of the upper extremities have been reported only rarely. We have reported the case of a patient with HOS who has both hypoplastic peripheral upper extremity vasculature and evidence of MVP.

Combined liver kidney transplantation in primary hyperoxaluria type I. Prevention of the recidive of calcium oxalate deposits in the renal graft.

We report the case of a 31-year-old patient who underwent combined liver and kidney transplantation for primary hyperoxaluria type I. Intensive hemodialysis was performed before the intervention and post-operatively in order to maintain plasma oxalate levels near the normal range. In spite of the correction of the liver enzyme deficiency, oxalate removal from the tissular stores led to prolonged hyperoxaluria, more longer than one year after the transplantation, as already reported. This increased urinary oxalate excretion exposes the renal graft to the risk of recurrence of calcium oxalate deposits and stone formation during a prolonged period. Hemodialysis in the postoperative period and fluid intake allowing a large urine volume might be able to decrease the concentration of urinary oxalate under the critical value of 300 mumol/l, at which supersaturation of urine in respect of calcium oxalate occurs.

Case report: cavernous hemangioma of the liver.

Although cavernous hemangioma is the most common benign tumor of the liver, controversy persists regarding diagnosis and management of these lesions. With the development of multiple noninvasive modalities to visualize the liver, hepatic cavernous hemangiomas are recognized with increased frequency. The authors report the unusual case of a post-menopausal woman on no exogenous estrogen therapy who had a cavernous hemangioma that remained stable for approximately 10 years before dramatically increasing in size. This patient illustrates the vague symptoms associated with cavernous hemangiomas and the unpredictability of growth. Although estrogens have been reported trophic, this patient had no exogenous or endogenous estrogen supply, yet her lesion reached massive proportions. Modalities necessary to assure accurate diagnosis and factors influential in management are discussed.