Nanopores: maltoporin channel as a sensor for maltodextrin and lambda-phage

BACKGROUND: To harvest nutrition from the outside bacteria e.g. E. coli developed in the outer cell wall a number of sophisticated channels called porins. One of them, maltoporin, is a passive specific channel for the maltodextrin uptake. This channel was also named LamB as the bacterial virus phage Lambda mis-uses this channel to recognise the bacteria. The first step is a reversible binding followed after a lag phase by DNA injection. To date little is known about the binding capacity and less on the DNA injection mechanism. To elucidate the mechanism and to show the sensitivity of our method we reconstituted maltoporin in planar lipid membranes. Application of an external transmembrane electric field causes an ion current across the channel. Maltoporin channel diameter is around a few Angstroem. At this size the ion current is extremely sensitive to any modification of the channels surface. Protein conformational changes, substrate binding etc will cause fluctuations reflecting the molecular interactions with the channel wall. The recent improvement in ion current fluctuation analysis allows now studying the interaction of solutes with the channel on a single molecular level. RESULTS: We could demonstrate the asymmetry of the bacterial phage Lambda binding to its natural receptor maltoporin. CONCLUSION: We suggest that this type of measurement can be used as a new type of biosensors

Full-length human placental sFlt-1-e15a isoform induces distinct maternal phenotypes of preeclampsia in mice

<div><p>Objective</p><p>Most anti-angiogenic preeclampsia models in rodents utilized the overexpression of a truncated soluble fms-like tyrosine kinase-1 (sFlt-1) not expressed in any species. Other limitations of mouse preeclampsia models included stressful blood pressure measurements and the lack of postpartum monitoring. We aimed to 1) develop a mouse model of preeclampsia by administering the most abundant human placental sFlt-1 isoform (hsFlt-1-e15a) in preeclampsia; 2) determine blood pressures in non-stressed conditions; and 3) develop a survival surgery that enables the collection of fetuses and placentas and postpartum (PP) monitoring.</p><p>Methods</p><p>Pregnancy status of CD-1 mice was evaluated with high-frequency ultrasound on gestational days (GD) 6 and 7. Telemetry catheters were implanted in the carotid artery on GD7, and their positions were verified by ultrasound on GD13. Mice were injected through tail-vein with adenoviruses expressing hsFlt-1-e15a (n = 11) or green fluorescent protein (GFP; n = 9) on GD8/GD11. Placentas and pups were delivered by cesarean section on GD18 allowing PP monitoring. Urine samples were collected with cystocentesis on GD6/GD7, GD13, GD18, and PPD8, and albumin/creatinine ratios were determined. GFP and hsFlt-1-e15a expression profiles were determined by qRT-PCR. Aortic ring assays were performed to assess the effect of hsFlt-1-e15a on endothelia.</p><p>Results</p><p>Ultrasound predicted pregnancy on GD7 in 97% of cases. Cesarean section survival rate was 100%. Mean arterial blood pressure was higher in hsFlt-1-e15a-treated than in GFP-treated mice (∆MAP = 13.2 mmHg, p = 0.00107; GD18). Focal glomerular changes were found in hsFlt-1-e15a -treated mice, which had higher urine albumin/creatinine ratios than controls (109.3±51.7μg/mg vs. 19.3±5.6μg/mg, p = 4.4x10^-2; GD18). Aortic ring assays showed a 46% lesser microvessel outgrowth in hsFlt-1-e15a-treated than in GFP-treated mice (p = 1.2x10^-2). Placental and fetal weights did not differ between the groups. One mouse with liver disease developed early-onset preeclampsia-like symptoms with intrauterine growth restriction (IUGR).</p><p>Conclusions</p><p>A mouse model of late-onset preeclampsia was developed with the overexpression of hsFlt-1-e15a, verifying the <i>in vivo</i> pathologic effects of this primate-specific, predominant placental sFlt-1 isoform. HsFlt-1-e15a induced early-onset preeclampsia-like symptoms associated with IUGR in a mouse with a liver disease. Our findings support that hsFlt-1-e15a is central to the terminal pathway of preeclampsia, and it can induce the full spectrum of symptoms in this obstetrical syndrome.</p></div

Pre-expanded thin DIEP free flap in pediatric upper extremity reconstruction for burn sequelae: A case report

International audienceDeep burns sequelae involving the upper limb are challenging even for experienced surgeons, mainly because local reconstructive options and donor sites are often compromised. The use of free flaps for this type of reconstruction remains difficult due to the small recipient vessel diameter and tendency to vasospasm. Moreover, pediatric cases bring the challenge to another level. We present the case of a 13-year-old girl presenting major retractile sequelae of the upper left limb, including complete wrist immobilization combining wrist hyper-extension, ulnar deviation deformity, and a ulno-carpal dislocation. She was referred to our department where a two-stage reconstruction was performed using a pre-expanded free deep inferior epigastric artery perforator (DIEP) flap. The first surgery consisted of placing two kidney-shaped expanders in a subfascial plane in the hypogastric region. Four months later, after a bi-weekly expansion, an excision of the scar tissue, and the DIEP flap transfer were completed. At the 12-month follow-up evaluation, both aesthetic and functional results were satisfactory, with a good contour and regained mobility of the wrist

Spatio-temporal summarizing method of periodic image sequences with Kohonen Maps

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Prognosis associated with initial care of increased fasting glucose in early pregnancy: A retrospective study

Aim. – To evaluate whether the initial care of women with fasting plasma glucose (FPG) levels at 5.1–6.9 mmol/L before 22 weeks of gestation (WG), termed ‘early fasting hyperglycaemia’, is associated withfewer adverse outcomes than no initial care.Methods. – A total of 523 women with early fasting hyperglycaemia were retrospectively selected in ourdepartment (2012–2016) and separated into two groups: (i) those who received immediate care(n = 255); and (ii) those who did not (n = 268), but had an oral glucose tolerance test (OGTT) at or after22 WG, with subsequent standard care if hyperglycaemia (by WHO criteria) was present. The number ofcases of large-for-gestational age (LGA) infants, shoulder dystocia and preeclampsia with initial care ofearly fasting hyperglycaemia were compared after propensity score modelling and accounting forcovariates.Results. – Of the 268 women with no initial care, 134 had hyperglycaemia after 22 WG and thenreceived care. Women who received initial care vs those who did not were more likely to be insulin-treated during pregnancy (58.0% vs 20.9%, respectively; P < 0.00001), gained less gestational weight(8.6 5.4 kg vs 10.8 6.1 kg, respectively; P < 0.00001), had a lower rate of preeclampsia [1.2% vs 2.6%,respectively; adjusted odds ratio (aOR): 0.247 (0.082–0.759), P = 0.01], and similar rates of LGA infants (12.2%vs 11.9%, respectively) and shoulder dystocia (1.6% vs 1.5%, respectively). When initial FPG levels were5.5 mmol/L (prespecified group, n = 137), there was a lower rate of LGA infants [6.7% vs 16.1%, respectively;aOR: 0.332 (0.122–0.898); P = 0.03].Conclusion. – Treating women with early fasting hyperglycaemia, especially when FPG is 5.5 mmol/L,may improve pregnancy outcomes, although this now needs to be confirmed by randomized clinicaltrials

Reconstruction of cardiac Cine MR Images using analytic image and neural networks

International audienc

The Autonomization Principle in Vascularized Flaps: An Alternative Strategy for Composite Tissue Scaffold In Vivo Revascularization

International audienceAutonomization is a physiological process allowing a flap to develop from the reconstructed wound bed. This phenomenon has been used since the early application of flap surgeries but still remains poorly understood. Reconstructive strategies have greatly evolved since, and fasciocutaneous flaps have progressively replaced muscle-based reconstructions, ensuring better functional outcomes with great reliability. However, plastic surgeons still encounter challenges in complex cases where conventional flap reconstruction reaches its limitations. Furthermore, emerging bioengineering applications, such as decellularized scaffolds allowing a complex extracellular matrix to be repopulated with autologous cells, also face the complexity of revascularization. The objective of this article is to gather evidence of autonomization phenomena. A systematic review of flap autonomization is then performed to document the minimum delay allowing this process. Finally, past and potential applications in bio- and tissue-engineering approaches are discussed, highlighting the potential for in vivo revascularization of acellular scaffolds