Experimental infection of bed bugs (Cimex lectularius L.) with Burkholderia multivorans.

The bacterium Burkholderia multivorans is an opportunistic nosocomial pathogen of humans. A previous study reported molecular detection of this bacterium in several specimens of the common bed bug (Cimex lectularius L.) collected from an elderly care facility in the U.S.A., raising questions about the possibility of vector-borne transmission. However, the ability of B. multivorans to colonize bed bugs and the ability of bed bugs to transmit the bacteria both remained untested. To resolve this knowledge gap, here we performed a set of experiments to examine the persistence and shedding of B. multivorans following ingestion by bed bugs in a blood meal. We isolated viable B. multivorans from the bodies of bed bugs for up to 13 days post-ingestion, but bacterial load substantially diminished over time. By 16 days post-ingestion, the bacteria could not be isolated. Further, B. multivorans was not shed in the saliva of infected bugs during feeding nor was it transmitted vertically from infected insects to their progeny. Based on these results, significant biological or mechanical transmission of B. multivorans to humans by bed bugs appears unlikely. Nonetheless, some viable bacteria were passively shed into the environment through defecation, a process which could potentially contribute to transmission through indirect contamination under rare circumstances.

Molecular detection of Rickettsia infection in field-collected bed bugs.

Bed bugs are now one of the most prevalent human-associated, blood-feeding pests in the urban world, but few studies of their association with human pathogens have been conducted since their resurgence. Here, we used PCR to screen samples of field-collected bed bugs (Cimex spp.) for the presence of Rickettsia bacteria and we describe the first detection of an uncharacterized Rickettsia in Cimex lectularius in nature. Rickettsia was detected in 5/39 (12.8%) of the bed bug samples tested. In particular, three pools from the USA and two individual insects from the UK were positive for Rickettsia DNA. Sequencing and analysis of a fragment of the citrate synthase gene (gltA) from positive samples from each country revealed that the Rickettsia detected in both were identical and were closely related to a Rickettsia previously detected in the rat flea Nosopsyllus laeviceps. Additional experiments indicated that the Rickettsia localizes to multiple tissues in the bed bug and reaches high titres. Attempts were made to infect mammalian cells in culture but these efforts were inconclusive. Our findings suggest that Rickettsia are secondary endosymbionts of bed bugs and have potential implications for both bed bug control and public health. However, further investigation is required to determine the pathogenicity of this Rickettsia, its transmission mechanisms, and its contributions to bed bug physiology.

[Suffering at work among medical students: qualitative study using semi-structured interviews]. / Souffrance au travail des étudiants en médecine : étude qualitative par entretiens semi-dirigés.

INTRODUCTION: Suffering at work among health professionals is a hot topic. Medical students, doctors of tomorrow, are far from being spared. Prevalence of anxiety and mood disorders range from 20.3 to 69 % for the former and from 12 to 30 % for the latter. The purpose of this article is to determine these factors by qualitative research, according to medical students' points of view. METHODS: It is a qualitative study using semistructured interviews. The analysis is done according to the Grounded Theory. RESULTS: 12 medical students are interviewed. They expressed difficulties at work and positive factors. Three major themes are identified in selective coding: occupational factors, " study " factors and individual factors. All themes are both a source of well-being and ill-being according to the situations specified in the results. CONCLUSION: Studying medicine includes positive and negative aspects. Abandonment issues, lack of recognition and insufficient coaching emerge from our study. Screening of suffering at work should be systematic for medical students.

INTRODUCTION: La souffrance au travail chez les professionnels de santé est un sujet d'actualité. Les étudiants en médecine, médecins de demain, sont loin d'être épargnés. Ils présentent notamment des troubles anxieux et de l'humeur dont les prévalences s'échelonnent de 20,3 à 69 % pour les premiers et de 12 à 30 % pour les seconds. Cette étude a pour objectif de déterminer ce qui est ressenti comme positif ou négatif au travail du point de vue des étudiants hospitaliers. Matériel et méthode : Il s'agit d'une étude qualitative par entretiens semi-dirigés. L'analyse se fait selon une thématisation progressive en suivant la Grounded Theory, ou théorisation ancrée, méthode issue des sciences sociales, visant à élaborer une théorie des représentations, non à partir d'hypothèses prédéterminées, mais à partir de données de terrain recueillies par entretiens. Résultats : La variation est maximale. La saturation des données a été atteinte avec 12 sujets. Ceux-ci ont exprimé des difficultés au travail mais aussi des facteurs de ressenti positif. Trois grands thèmes ont été définis en codage sélectif : les facteurs professionnels, les facteurs " étude " et les facteurs individuels. Quelle que soit la thématique abordée, les relations avec le ressenti du travail sont à la fois source d'épanouissement et de souffrance selon les situations précisées dans les résultats. CONCLUSION: Le vécu des études médicales comprend des aspects positifs et négatifs. Les problématiques de délaissement, de manque de reconnaissance ou encore d'accompagnement insuffisant ressortent de notre étude. Ceci ouvre des pistes de prévention. Le dépistage d'un malêtre au travail devrait être systématique chez ces étudiants.

[Returning to work after an acute coronary syndrome: When waiting is wasting]. / Retour au travail après un accident coronarien aigu.

BACKGROUND: Return to work (RTW) after acute coronary syndrome (ACS) is an important issue for the patient's future. AIMS: The study aim was to determine whether RTW practice complies with guidelines or is delayed by failure in patient management. We analysed the factors influencing RTW beyond the 90-day period recommended by guidelines. METHODS: We conducted a survey of 216 self-employed workers admitted to the hospital for ACS using self-report questionnaires and medical examination. Factors influencing RTW, occupational and cardiac features, and recall and source of medical information were investigated. RESULTS: Ninety-three of 216 patients did not return to work by 90 days, despite good cardiac performance in 30 cases (32 %). The mean sick leave duration was 93.3±103.7 days. Advice concerning return to work was completely missing for 44 % of patients. Cardiac performance was independent of sick leave duration, but was correlated with the likelihood of RTW (P<0.001). Patients assimilated about 70 % of the medical information they were provided, but only 53 % of work-related information. Recall of work-related information was better among patients admitted to a rehabilitation facility (65 %) compared to those who did not receive rehabilitation (P<0.05). CONCLUSION: Cardiologists should assess the patient's cardiac performance within 2 months after ACS. Patient management should also include cardiac rehabilitation or therapeutic education toward improving information recall.

Knockdown of mitogen-activated protein kinase (MAPK) signalling in the midgut of Anopheles stephensi mosquitoes using antisense morpholinos.

Arthropod-borne infectious diseases are responsible for nearly 1.5 million deaths annually across the globe, with malaria responsible for >50% of these deaths. Recent efforts to enhance malaria control have focused on developing genetically modified Anopheles mosquitoes that are resistant to malaria parasite infection by manipulating proteins that are essential to the immune response. Although this approach has shown promise, the lack of efficient genetic tools in the mosquito makes it difficult to investigate innate immunity using reverse genetics. Current gene knockdown strategies based on small interfering RNA are typically labourious, inefficient, and require extensive training. In the present study, we describe the use of morpholino antisense oligomers to knockdown MEK-ERK signalling in the midgut of Anopheles stephensi through a simple feeding protocol. Anti-MEK morpholino provided in a saline meal was readily ingested by female mosquitoes with minimal toxicity and resulted in knockdown of total MEK protein levels 3-4 days after morpholino feeding. Further, anti-MEK morpholino feeding attenuated inducible phosphorylation of the downstream kinase ERK and, as predicted by previous work, reduced parasite burden in mosquitoes infected with Plasmodium falciparum. To our knowledge, this is the first example of morpholino use for target protein knockdown via feeding in an insect vector. Our results suggest this method is not only efficient for studies of individual proteins, but also for studies of phenotypic control by complex cell signalling networks. As such, our protocol is an effective alternative to current methods for gene knockdown in arthropods.

Aortic thrombosis and ulcerative colitis.

Arterial thrombotic accidents in the course of inflammatory bowel disease are rare. They generally affect young adults whose disease is active. We observed a case of aortic and renal arterial thrombosis in a 40-year-old woman who was suffering from ulcerative colitis. Surgical thrombectomy ensured good postoperative results, without any ischemic or renal sequelae. Six days later the patient presented with distal thrombosis of the splenic artery, which receded under anticoagulant treatment. The physiopathology of thromboembolic events in the course of inflammatory bowel disease is uncertain. Such events result from a state of hypercoagulability of various mechanisms, which can be observed in active inflammatory bowel disease. This possibility of serious arterial thrombosis argues in favor of long-term anticoagulant treatment when inflammatory bowel disease is active.

Treatment of popliteal arterial aneurysm using a superficial femoral artery autograft.

The usefulness of aggressive surgical management of popliteal arterial aneurysm is now widely accepted. Reconstruction is usually performed using either prosthesis or saphenous vein autograft. Autografts are preferable but not always possible because of problems of availability and congruence. An alternative conduit for cases involving lesions spanning the articular midline of the knee is the superficial femoral artery. From 1993 to 1998, we used superficial femoral artery autografts to treat a total of 18 aneurysms in 12 patients. All patients were male with a mean age of 66 years (range, 42 to 75). Fourteen aneurysms were treated during elective procedures, including four in combination with aortic repair. The remaining four were treated on an emergency basis. Exposure was achieved via the internal medial route in all cases. Treatment consisted of exclusion or aneurysmorraphy. The mean length of the autograft harvested from the ipsilateral thigh was 10.2 cm (range, 6-18). The harvested graft was replaced by a PTFE prosthesis. Our results show that superficial femoral artery autografts are a suitable alternative for two indications: for patients with small aneurysms located in the middle of the popliteal artery, since autografts provide excellent congruence, and for patients with no other useable donor vein or concurrent deep venous thrombosis.

[Quantitative assessment of carotid stenosis: comparison between Doppler ultrasound, spiral computed tomography angiography, magnetic resonance angiography and digital angiography]. / Quantification du degré de sténose carotidienne. Comparaison entre l'échographie Doppler, le scanner hélicoïdal, l'imagerie par résonance magnétique et l'angiographie numérise.

BACKGROUND: The North American Symptomatic Carotid Endarterectomy Trial has confirmed the benefit of carotid endarterectomy in comparison to medical treatment in stroke prevention in symptomatic patients having a carotid stenosis of 70% or more. The Asymptomatic Carotid Atherosclerosis Study has concluded that the benefit of surgical treatment remains significant in asymptomatic patients with 60% (or more) stenosis of the ipsilateral internal carotid artery, when mortality rate remains inferior to 3%. In these two trials, angiography has been used to quantify the stenosis. Though this test is carrying some neurological and renal risks, replacing the angiography stenosis grading for a non or less invasive test, seems to be permissible. METHODS: In our retroprospective study, the assessments of the carotid stenosis by several non-invasive tests findings were compared to the angiography results. Nineteen carotid arteries of fifteen patients, both symptomatic and asymptomatic, having a carotid stenosis at least 60% or more and being detected by the Doppler ultrasound were explored either by magnetic resonance angiography (MRA), spiral computed tomography angiography (SCTA) and angiography. RESULTS: The ultrasonography and angiography findings were well correlated (r=0,88; p<0.002) according to the Spearman test. The assessments of the MRA were better correlated to the angiography than to the SCTA (respectively r=0.91, p<0.0001 and r=0,68, p<0.001). Using both ultrasonography and MRA as a confirmatory test, the rate of injustified carotid endarterectomy was 25%. And this rate rose up to 33% when the ultrasonography was used with the SCTA. It is noteworthy that negative predictive value of ARM was 100%. To reduce the mortality rate, several surgical teams managed the carotid stenosis without angiography. CONCLUSION: MRA could replace angiography, on condition that the rate of unjustified carotid endarterectomy lowers and becomes acceptable. Far reaching complementary studies are necessary to confirm the fiability of those non-invasive tests. In order to raise the benefit to carotid endarterectomy, the research studies should turn to the predictive score determination of a surgical international risk and towards the "High benefit" patients groups after endarterectomy.

Primary malignant tumors of the venous system in the lower extremities.

Malignant tumors arising from venous walls in the lower extremity are uncommon. Histologically they are divided into two groups: hemangioendotheliomas of intermediate malignancy and leiomyosarcomas. This report describes a retrospective series of seven primary venous tumors observed in four men and three women with a mean age of 49.8 years (range: 18 to 64 years) who underwent surgical treatment between 1985 and 1995. The tumor was located in the superficial femoral vein in four patients, common femoral vein in two patients, and greater saphenous vein in one patient. A palpable tumor was present in five patients, localized pain in two patients, and metastasis in two patients. The histological diagnosis was leiomyosarcoma in six patients and hemangioendothelioma in one patient. Surgical treatment consisted of complete resection in six patients and partial excision in one patient. Venous reconstruction was performed in two patients and adjuvant radiation therapy in four patients. There was no operative morbidity/mortality. Median survival was 31 months. Four patients with leiomyosarcoma died from metastasis. Two patients with leiomyosarcoma and one with hemangioendothelioma are alive at 9 years, 16 months, and 9 months, respectively. Local recurrence was never observed after complete resection. The prognosis of venous leiomyosarcoma of the lower extremities is poor due to early occurrence of metastasis. Doppler ultrasound and MRI are useful to establish early diagnosis at the nontumoral stage. Improvement in the prognosis of leiomyosarcoma may justify perioperative chemotherapy before and after radical surgical excision.

[Value of imaging in early diagnosis of peripheral vein tumors]. / Apport de l'imagerie dans le diagnostic précoce des tumeurs veineuses périphériques.

Peripheral venous tumors are uncommon and their delayed clinical expression leads to poor prognosis. We report a series of 7 cases including 6 leiomyosacromas and 1 hemangioendothelioma. Duplex Doppler and MR imaging appeared to be best suited for diagnosis, allowing an evaluation of extension and an analysis of associated endoluminal thrombi. These imaging techniques help guide surgery and improve prognosis.

[Effect of meteorological variations on the emergence of deep venous thrombosis of the leg]. / Influence des variations météorologiques sur la survenue de thrombose veineuse profonde des membres inférieurs.

INTRODUCTION: Recent articles have established a significant relationship between metereology variables and the development of vascular disease. We performed a retrospective study to determine relationships between the development of deep vein thrombosis in the lower limb and certain meteorology variables. MATERIALS AND METHODS: We identified 345 cases of phlebitis in 1995. We studied the distribution of the number of venous thrombosis per day, per month and per season. We compared certain meteorological data (atmospheric pressure, temperature, mean hygrometery) for days with and days without venous thrombosis and the atmospheric variations during the 48 hours prior to venous thrombosis. RESULTS: There was a significant relationship (p < 0.004) between the mean number of cases of phlebitis recorded per day and season with winter predominating. On days when phlebitis occurred, the atmospheric pressure was significantly lower (p < 0.05). The number of thrombotic events was significantly different on days when the variation was greater than 10 hectopascals than on days when the variation was less than 10 hectopascals (p < 0.05). CONCLUSIONS: In our study, deep vein thrombosis of the lower limb was significantly associated with certain meteorology variables. Prospective multicentric studies are needed to confirm these relationships.

[Echo-Doppler and stenosis of the renal arteries. Report of 86 cases]. / Echo-Doppler et sténose des artères rénales. Etude a propos de 86 patients.

Duplex-scan is widely used for arterial stenosis diagnosis. Its role in detection of renal artery stenosis remains controversial (2, 17, 19, 28). The aim of this study was to determine retrospectively if duplex-scan is accurate for diagnosis of renal artery stenosis. During 36 months, 764 patients had a renal artery examination with duplex-scan: 90 patients had also renal arteriography. Duplex-scan was feasible in 95% of cases (excess bowel gas or major obesity gave to duplex-scan incomplete results in four patients upon 90). Ninety-three per cent of patients had hypertension; 20% had renal failure; 61% had obstruction of coronary, carotid artery or lower limb arteries. Nineteen patients among 86 had also an intravenous renal arteriography. We compared duplex-scan with venous angiography and intra-arterial arteriography. Duplex-scan criteria for stenoses were: a maximal systolic velocity (MSV) above 180 cm/s for detection of 60% to 79% stenoses and a MSV superior to 300 cm/s for detection of 80% to 99% stenoses. Global results showed a good sensitivity 59/64 (92%) and specificity 112/117 (96%) for duplex-scan. Duplex-scan is accurate for diagnosis of renal artery stenosis in a selected population.

Subclavian artery revascularization for myocardial ischemia.

A 54-year-old woman had a secondary occlusion of the subclavian artery proximal to the internal mammary artery, which had been used for an anterior interventricular artery bypass, and was the source of recurrent angina. A left carotid-to-subclavian bypass was performed with success. This rare complication underscores the need for careful selection and surveillance of candidates for myocardial revascularization using the internal mammary artery.

[Superior vena cava syndrome and Riedel's thyroiditis. Report of a case: review of the literature]. / Syndrome cave supérieur et thyroidite de Riedel. A propos d'un cas: revue de la littérature.

The authors present the case of a 42-year-old female patient, initially admitted to hospital for the etiological diagnosis--which remained negative--and the treatment of a superior vena cava syndrome. This patient was seen again two years later as the superior vena cava syndrome recurred, while a thyroid syndrome appeared at the same time. Exeresis followed by a clinicopathological study demonstrated Riedel's chronic fibrous thyroiditis. The authors study the causal relationships between both conditions and their integration into multifocal fibroses. To their knowledge, this is the first case in which the superior vena caval syndrome is the site of occurrence of fibrosis, precedes the thyroid involvement. The new radiological technique at our disposal--CT, MRI--should allow more easily searching for the various sites of the fibrosing disease (biliary ducts, pancreas, duodenum, retroperitoneum, mediastinum, orbits), and immunological studies will make it possible to better classify them and define their pathogenesis.

[Leg ulcers in Werner's syndrome. Report of one case]. / Les ulcères de jambe du syndrome de Werner. A propos d'un cas.

Werner's syndrome (adult progeria) is a rare autosomal recessive condition characterized mainly by a characteristic habitus (short stature, light body weight) scleroderma like changes of the limbs and premature aging. Chronic leg ulcers appears in about fifty per cent of the patients. These ulcers can be related to the combination of mechanical factors on atrophic subcutaneous tissue and skin of the feet and leg associated with early arteriosclerosis (20%) and diabetes mellitus (60%).

Arterioportal fistulas: twelve cases.

During the last 20 years, we encountered 14 arterioportal fistulas in 12 patients. Gastrointestinal hemorrhage or mesenteric artery insufficiency were the most frequent conditions found after the diagnosis. Arterioportal arterial fistulas were congenital in two cases and acquired in 10; seven of these 10 were iatrogenic. One patient had three successive and different sites of arterioportal fistula. The fistula originated from a branch of the celiac axis in nine cases, the superior mesenteric artery in three, and the inferior mesenteric artery in two. One patient died of massive anal bleeding before any treatment was possible. Eight fistulas were treated surgically and five by arterial embolization. After treatment there was no early mortality, while hemorrhagic and ischemic complications regressed in all cases. Three hemorrhagic recurrences were observed in patients with preexisting cirrhosis (two cases) or by recurrence of a congenital arteriovenous fistula (one case). Closure of symptomatic arterioportal fistula is justified. The choice of the most appropriate method for each patient should be discussed between the surgeon and interventional radiologist on a case by case basis.

[Prevention of nosocomial infections at a cardiovascular surgery unit: therapeutic tactics, efficacy and results]. / Prévention des infections nosocomiales dans un service de chirurgie cardio-vasculaire: tactiques thérapeutiques, efficacité, résultats.

The experience of prevention of nosocomial infections inside a cardiovascular surgical unit leads to insist, among the various tactics, on the quality and the mode of disinfection of the operating room and the intensive care unit, in particular, the technics of air and surface processing (by Anios) of sterilizing water (by Hyconium B and Filtranios), of sterilized respirators (by Formobloc). Quality and efficiency are bacteriologically controlled. The good results, obtained for 3 years, testify of the efficiency of such technics. However some architectural and structural drawbacks can jeopardize a strict compliance towards prevention of nosocomial infections.

Use of Permcath (Quinton) catheter in uraemic patients in whom the creation of conventional vascular access for haemodialysis is difficult.

During the last 4 years, the Permcath Quinton double-lumen silicone catheter was inserted into the internal jugular vein of 57 uraemic patients with difficulty for creating conventional vascular access for haemodialysis. In 4 patients, with definitive contraindication of conventional vascular access, this catheter still permits haemodialysis after a duration of 8-25 months. In 25 further patients with terminal uraemia, but poor vein system, it allowed the maturation of an arteriovenous fistula after 2-14 months of use. In 17 patients already on chronic haemodialysis, but who lost abruptly their vascular access (15 grafts and 2 arteriovenous fistulae), it allowed a new arteriovenous fistula to mature in 16 cases after a mean duration of 7.3 +/- months. In 5 patients with short life expectancy because of neoplasia, it allowed to dialyse them until their death which occurred after 6.5 +/- 2.2 months. In 6 patients with acute renal failure and haemostasis problems, it allowed to perform not only dialysis, but also plasmapheresis in 3 and parenteral nutrition in 3 other cases. The complications were the following: sepsis (n = 3); episodes of hypocoagulability due to inadvertent injection of heparin stored in the lumen (n = 2), thrombosis of the lumen (n = 3), and insufficient flow (n = 6). In no case these complications prevented continuation of haemodialysis. The catheter had to be removed in 2 cases because of septis and in 1 case because of insufficient flow. In 3 cases the catheter had to be replaced because of thrombosis and in 1 case because of laceration. These complication rates are, however, fewer than those reported in the literature for arteriovenous shunts or rigid subclavian and femoral catheters. The Permcath catheter seems, therefore to be the method of choice for immediated vascular access in patients in whom the creation of conventional vascular access is difficult.

[Malignant venous tumors of the limbs. Apropos of 6 cases]. / Les tumeurs veineuses malignes des membres. A propos de 6 observations.

The authors report six personal cases of malignant venous tumours of the limbs, tumour pathology of the inferior vena cava being excluded from this study. Diagnostic features are described together with the various therapeutic possibilities. This discussion forms the basis of a review of the worldwide literature, but stresses two problems which determine the prognosis: that of diagnosis, which in the majority of cases is very late, and that of their prognosis, which remains somber because of their tendency to metastasize by blood-borne spread and that of locoregional recurrences. Finally, the authors suggest a three stage classification, taking into account not only macroscopic pathological features but also the results of the various special investigations which have led to the diagnosis. Prognostic correlation based upon the features involved in this classification is entirely satisfactory.