Electroacoustic miniaturized DNA-biosensor

A micrometer-sized electroacoustic DNA-biosensor was developed. The device included a thin semi-crystalline polyethylene terephthalate (PET) dielectric layer with two Ag microband electrodes on one side and a DNA thiol-labeled monolayer adsorbed on a gold surface on the other. A resonance wave was observed at 29 MHz with a network analyzer, upon AC voltage application between the two Ag electrodes, corresponding to electromechanical coupling induced by molecular dipoles of the PET polymer chain in the dielectric layer. It was found that the device size and geometry were well adapted to detect DNA hybridization, by measuring the capacity of the resonance response evolution: hybridization induced polarization of the dielectric material that affected the electromechanical coupling established in the dielectric layer. The 0.2 mm2 sensor sensitive area allows detection in small volumes and still has higher detection levels for bioanalytical applications, the non-contact configuration adopted avoids electric faradic reactions that may damage biosensor sensitive layers, and finally, PET is a costless raw material, easy to process and well adapted for large scale production. The well-balanced technological and economic advantages of this kind of device make it a good candidate for biochip integration

Electroacoustic Polymer Microchip as an Alternative to Quartz Crystal Microbalance for Biosensor Development

Laser photoablation of poly(ethylene terephthalate) (PET), a flexible dielectric organic polymer, was used to design an acoustic miniaturized DNA biosensor. The microchip device includes a 100-μm-thick PET layer, with two microband electrodes patterned in photoablated microchannels on one side and a depressed photoablated disk decorated by gold sputtered layer on the other side. Upon application of an electric signal between the two electrodes, an electroacoustic resonance phenomenon at ∼30 MHz was established through the microelectrodes/PET/ gold layer interface. The electroacoustic resonance response was fitted with a series RLC motional arm in parallel with a static C0 arm of a Buttlerworth-Van Dyke equivalent circuit: admittance spectra recorded after successive cycles of DNA hybridization on the gold surface showed reproducible changes on R, L, and C parameters. The same hybridizations runs were performed concomitantly on a 27-MHz (9 MHz, third overtone) quartz crystal microbalance in order to validate the PET device developed for bioanalysis applications. The electroacoustic PET device, ∼100 times smaller than a microbalance quartz crystal, is interesting for the large-scale integration of acoustic sensors in biochips

Pigmentation noire des deux os de l’avant-bras après traitement par minocycline pour pseudarthroseseptique. A propos d’un cas et revue de la littérature

International audienceWe report the case of a 28-year-old man with a septic forearm non-union treated with minocycline for 3 months. At the time of reconstructive surgery, the radius and ulna were entirely black. Surgical debridement until bleeding of both bone extremities resulted in a 5-cm defect that was filled with a cement spacer. Histology confirmed poorly vascularized bone with focal areas of acute inflammatory infiltrate at the non-union sites (highly suggestive of infection) and normal structure of the remaining diaphyseal bones, although black in color. Reconstruction with free vascularized fibula transfer was successful leading to complete bone healing. An incidental finding of minocycline-induced black bone discoloration should not change the surgeon's decision because there is no evidence of adverse effects on bone healing in the literature. Surgery can be performed safely at sites of minocycline-induced black bone pigmentation

Metacarpophalangeal joint instability in trapeziometacarpal osteoarthritis: A systematic review

International audienceThumb metacarpophalangeal instability is commonly found in conjunction with trapeziometacarpal osteoarthritis. If not corrected, it can have detrimental effects on the outcome. The authors describe the two types of metacarpophalangeal deformities - hyperextension and valgus - their pathophysiology and the surgical repair techniques available to surgeons. An algorithm for treating this instability is presented

Prognostic factors in two-stage flexor tendon reconstruction: Is it possible to predict surgical failure?

International audienceINTRODUCTION:Two-stage surgical reconstruction of the flexor tendons by the Hunter technique is the salvage option in case of old tears or a severely damaged fibro-osseous canal.HYPOTHESIS:The identification of poor prognostic factors during the assessment of injuries at presentation could help determine indications and predict failures.MATERIALS AND METHODS:We report a retrospective single center series of reconstruction of zone 2 of the flexor digitorum profundus of the long fingers between 2000 and 2012, in 22 patients, mean age 33 years old with a mean follow-up of 36.4 months.RESULTS:The total active range of motion (TAM) of the rays was 110° with a mean range of motion of the PIP and DIP of 71° and 39° respectively. Sixty-three percent of patients were satisfied and 73% returned to their professional activities. A group with good and fair results was determined based on the Strickland classification (68%, 15 patients, mean TAM 126°, mean QuickDASH 22.6) and a group with poor results (32%, 7 patients, mean TAM 77°, mean QuickDASH 43.4). The factors of a poor prognosis were associated injuries to the extensor apparatus, infection (phlegmon) (P=0.023) and joint injuries (P=0.09).DISCUSSION:There are no factors in the literature to predict a poor prognosis except for reconstruction of the flexor pollicis longus. A simplified procedure could provide better results in patients with associated injuries to the extensor apparatus, infection (phlegmon) or osteoarticular damage, in terms of the duration of physical therapy, additional surgery and overall socioeconomic cost. The results in the literature of superficialis finger reconstruction are significantly better (P<0.001).CONCLUSION:Although the Hunter technique is still the reference procedure for the reconstruction of flexor tendons, our study identified prognostic factors of poor functional results such as infection and associated extensor apparatus damage, which should orient the surgeon towards a simplified technique such as the superficialis finger procedure.LEVEL OF EVIDENCE:IV: retrospective study

Extensive limb-sparing surgery with reconstruction for sarcoma of the hand and wrist

International audienceBACKGROUND:Sarcoma rarely involves the hand or wrist. Extensive surgical excision is the current standard of care. At the extremities, such as the hand and wrist, limb-sparing surgery with reconstruction to provide optimal function is increasingly performed. A descriptive case-series study of 16 patients with sarcoma of the hand and wrist managed using limb-sparing surgery is reported here.MATERIAL AND METHODS:Of 19 patients with sarcoma of the hand or wrist treated between 1999 and 2012, 16 were managed using limb-sparing surgery. These were consecutive patients managed at a single-centre and studied retrospectively. The tumour involved the hand in 7 patients and the wrist in 9 patients. The procedure was primary in 6 patients, whereas 10 patients underwent secondary revision surgery. In 12 patients, reconstruction was performed for one or more of the following structures: nerves (n=2), tendons (n=3), bone (n=3), and/or skin (n=8). After surgical excision, the margins were R0 in 15 patients and R1 in 1 patient. At last follow-up, survival, pain, and function as reflected by the DASH and MSTS scores were assessed.RESULTS:After the median follow-up of 4.5years [1-13], 15 patients were alive with no local recurrence and 1 patient had lung metastases. Mean values were 18 [0-49] for the DASH score and 88.8% [53-100] for the MSTS score.DISCUSSION:Limb-sparing surgery reconciles the need to achieve complete tumour excision with the need to restore function. No limits should be placed on tumour excision, given the availability of effective reconstructive methods. The functional outcome depends on the tolerance of adjuvant treatments, most notably radiotherapy.LEVEL OF EVIDENCE:IV, retrospective study

Revision surgery for recurrent and persistent carpal tunnel syndrome: Clinical results and factors affecting outcomes

International audienceThirty-eight hands in 36 patients with recurrent or persistent carpal tunnel syndrome (CTS) were reviewed retrospectively after a mean of 51 months (range 12-86) to identify factors that may lead to poor outcomes after surgical management. Clinical assessment focused on pain and sensitivity recovery, measured with a VAS and Weber's two-point discrimination test, respectively. At the latest follow-up, we found 11 excellent, 15 good, nine fair and three poor results. The risk of fair or poor results was significantly higher in the presence of intraneural fibrosis, severe preoperative sensory deficit, neuroma of the palmar cutaneous branch of the median nerve, workers compensation claims and number of previous surgeries. This last factor also significantly increased the risk of intraneural fibrosis. Despite disappointing outcomes, identification of these factors may improve our prognostic ability for revision surgery in cases of recurrent CTS