Counterbalancing the use of ultrasound contrast agents by a cavitation-regulated system.

The stochastic behavior of cavitation can lead to major problems of initiation and maintenance of cavitation during sonication, responsible of poor reproducibility of US-induced bioeffects in the context of sonoporation for instance. To overcome these disadvantages, the injection of ultrasound contrast agents as cavitation nuclei ensures fast initiation and lower acoustic intensities required for cavitation activity. More recently, regulated-cavitation devices based on the real-time modulation of the applied acoustic intensity have shown their potential to maintain a stable cavitation state during an ultrasonic shot, in continuous or pulsed wave conditions. In this paper is investigated the interest, in terms of cavitation activity, of using such regulated-cavitation device or injecting ultrasound contrast agents in the sonicated medium. When using fixed applied acoustic intensity, results showed that introducing ultrasound contrast agents increases reproducibility of cavitation activity (coefficient of variation 62% and 22% without and with UCA, respectively). Moreover, the use of the regulated-cavitation device ensures a given cavitation activity (coefficient of variation less 0.4% in presence of UCAs or not). This highlights the interest of controlling cavitation over time to free cavitation-based application from the use of UCAs. Interestingly, during a one minute sonication, while ultrasound contrast agents progressively disappear, the regulated-cavitation device counterbalance their destruction to sustain a stable inertial cavitation activity.

An intelligent telecardiology system for offline wireless transmission and remote analysis of ECG.

This paper illustrates a wireless system developed for offline ECG transmission and its remote processing. At the transmit end, a standalone embedded system collects short duration ECG samples from the source, stores them in a RAM and then encodes these using a customized bi-phase modulation for offline transmission in ISM band. At the receive end, another embedded system extracts ECG data from the demodulated output of the wireless receiver and delivers to a desktop computer using the serial port. An application software stores these samples in a text file. At first, the bit error and packet error are computed from the received dataset. Then, computed ECG wave durations and intervals along with lead data plot are generated on a Graphical User Interface for preliminary level diagnosis. Test results with synthetic ECG from PTB diagnostic ECG database (ptb-db) for short range of communication are reported.

Numerical simulations of particle dynamics in a poststenotic blood vessel region within the scope of extracorporeal ultrasound stenosis treatment.

A numerical model was developed to predict the dynamics of a solid particle in a poststenotic blood vessel region. The flow through a 3D axisymmetric stenosis with 75% reduction in cross-section area was considered for inlet Reynolds numbers of 500 and 1000, which corresponds to typical values for the blood flow in human large arteries. Spherical particles were injected in the flow from the stenosis and tracked using the Discrete Phase Model (DPM) based on a Lagrangian approach. Within the scope of the development of ultrasound thrombolysis methods, the hydrodynamical forces predicted were used to evaluate the residence time of the particle and the minimal ultrasonic intensity required to keep it in the treatment region. For particle sizes larger than 400 µm, the intensity required appeared to be compatible with extracorporeal therapeutic ultrasound.

[Contribution of low-intensity pulsed ultrasounds to bone regeneration]. / Intérêt des ultrasons pulsés de faible intensité dans la stimulation de la régénération osseuse.

A maxillo-facial surgeon manages patients with bone defects due to trauma, malformations or of iatrogenic origin. The surgical management has potentially deleterious effects and its cost for society is increasing. Hence, it is crucial to develop techniques stimulating bone growth, stimulating the regeneration of a fracture or filling bone deficit. Ultrasounds (US), vibrations of the same nature as sound but with frequencies above the highest audible frequency for men (above 20 kHz), are used in many fields, particularly in medicine, usually at frequencies of around 0.5 to 5 MHz (million cycles per second). Their biological effects are not fully understood yet, but it is well known that US have effects on organic tissues when their mechanical energy is converted into thermic energy. These effects induce vasodilation and modification of membrane permeability. Several publications present the benefit of US for the stimulation of bone regeneration after a fracture. We present an overview of current knowledge on the effect of pulsed ultrasound on craniofacial bone regeneration, with study results conducted within Inserm unit U1032 in Lyon, the current reference lab on this issue.

[The impact of low intensity pulsed ultrasound on mouse skull bone osteoblast cultures]. / Ultrasons pulsés de faible intensité (LIPUS): effets sur des cultures d'ostéoblastes crâniens de souris.

INTRODUCTION: Low intensity pulsed ultrasound (LIPUS) is one of the methods used to stimulate bone regeneration. This technique is still not well known or explained. The expression of several proteins (VEGF, IL-8, FGF-ß, IL-1 ß) or genes (ALP and OP) was increased after being exposed to weak ultrasounds, whereas IL-6 and TNF-α were not affected. The purpose of this study was to verify and understand the mechanisms involved in this stimulation, and more specifically to understand if the stimulation concerned only cellular differentiation factors or if it also affected transcription of stem cells into osteoblasts. MATERIALS AND METHODS: Cultures of mouse skull bone osteoblasts were exposed to pulsed ultrasounds of varying intensities during three consecutive days. The effect of this stimulation was assessed by counting cells and determining the number of bone nodules formed. We studied various genes participating in osteoblast proliferation or in the differentiation and transcription of osteoblasts, using reverse transcriptase PCR. RESULTS: The cellular proliferation of osteoblasts was increased after stimulation by low intensity pulsed ultrasound. The expression of various genes involved in differentiation and transcription of stem cells into osteoblasts was increased, especially after stimulating at 100 mW/cm(2). DISCUSSION: Low intensity pulsed ultrasound allows stimulation of bone proliferation in vitro by stimulating osteoblastic differentiation and transcription.

[Craniofacial approach for orbital tumors and ultrasonic bone cutting]. / Voies d'abord craniofaciales des tumeurs orbitaires et découpe osseuse ultrasonique.

BACKGROUND: Removal of orbital tumors is a difficult problem. The goal of this study was to evaluate the advantages of the craniofacial approach to remove such tumors and to evaluate ultrasonic bone cutting during the procedure. METHOD: The authors reviewed their experience with 57 tumors of the posterior cavity using lateral craniofacial and frontal transsinus approaches. Orbital osteotomies were performed with mechanical instruments or piezoelectric bone surgery as a minimally invasive surgery. For each case, the quality of bone cutting and soft tissue damage were evaluated. RESULTS: Craniofacial approaches are simple and fast. Under the microscope, they provide a good view of the entire posterior orbital cavity. Using Piezosurgery, the functional results are good with no soft tissue damage. These advantages balance with the increased operative time required by ultrasonic bone cutting. CONCLUSION: This study shows the advantages of craniofacial approaches for removal of posterior orbital tumor. Moreover, the present preliminary report introduces and demonstrates the utility of piezoelectric bone surgery in craniofacial approaches for orbital tumors.

Ultrasonic osteotomy as a new technique in craniomaxillofacial surgery.

Ultrasound osteotomy is a new surgical technique used in dentistry to section hard tissues without damaging adjacent soft tissues. It was hypothesized that this could also be useful in craniofacial and orthognathic surgery. An ultrasonic device was employed in the following craniofacial surgical procedures: 144 Le Fort I osteotomies, 140 palatal expansions after Le Fort I osteotomies and 140 bilateral sagittal osteotomies; 2 Le Fort III osteotomies for treatment of Crouzon syndrome in two patients; 12 cases of unicortical calvarial bone grafting; removal of superior orbital roof in 25 cases of craniofaciostenosis; removal of external wall of the orbit in 10 cases of orbital cavity tumour; removal of anterior and posterior walls of the frontal sinuses in four cases of orbital cavity tumour. Integrity of soft tissues and surgical time were evaluated. Functional results were good without any soft-tissue damage being observed, but the overall operative time was increased. Ultrasound osteotomy is a new technical procedure that is advantageous for bone cutting in multiple situations, with minimal to no damage in adjacent soft tissues such as brain, palatal mucosa and the inferior alveolar nerve.

[Cardiobacterium hominis endocarditis. A case report]. / Endocardite à cardiobacterium hominis. A propos d'un cas.

We report the case of a Cardiobacterium hominis endocarditis causing an acute mitral insufficiency complicated of left heart failure. The patient has been treated after a few days by surgical valvuloplasty. Cardiobacterium hominis is a bacteria of the HACCEK group, bacille gram-negative, sometimes anaerobic, difficult to isolate. Recently, Polymerase Chain Reaction analysis appears to be effective for the the diagnosis in the identification of fastidious micro-organisms like Cardiobacterium hominis. We have reviewed in the literature 71 cases of Cardiobacterium hominis endocarditis; clinical presentation is often sub-acute, the bacteriological diagnosis is based on hemocultures for which the culture is slow and require enriched environments. Hemodynamic and thrombo-embolic complications are frequent because of the high pathogenicity of the bacteria which provides big and friable vegetations. Despite a high sensibility to antibiotherapy, surgical intervention is often required.

Cse1l is essential for early embryonic growth and development.

The CSE1L gene, the human homologue of the yeast chromosome segregation gene CSE1, is a nuclear transport factor that plays a role in proliferation as well as in apoptosis. CSE1 and CSE1L are essential genes in Saccharomyces cerevisiae and mammalian cells, as shown by conditional yeast mutants and mammalian cell culture experiments with antisense-mediated depletion of CSE1L. To analyze whether CSE1L is also essential in vivo and whether its absence can be compensated for by other genes or mechanisms, we have cloned the murine CSE1L gene (Cse1l) and analyzed its tissue- and development-specific expression: Cse1l was detected at embryonic day 7.0 (E7.0), E11.0, E15.0, and E17.0, and in adults, high expression was observed in proliferating tissues. Subsequently, we inactivated the Cse1l gene in embryonic stem cells to generate heterozygous and homozygous knockout mice. Mice heterozygous for Cse1l appear normal and are fertile. However, no homozygous pups were born after interbreeding of heterozygous mice. In 30 heterozygote interbreeding experiments, 50 Cse1l wild-type mice and 100 heterozygotes were born but no animal with both Cse1l alleles deleted was born. Embryo analyses showed that homozygous mutant embryos were already disorganized and degenerated by E5.5. This implicates with high significance (P < 0.0001, Pearson chi-square test) an embryonically lethal phenotype of homozygous murine CSE1 deficiency and suggests that Cse1l plays a critical role in early embryonic development.

[The treatment of a fracture of proximal end of the femur in own material]. / Leczenie zlaman blizszego konca kosci udowej w materiale wlasnym.

Results of treatment for fracture of proximal end of the femur in 263 patients (86 males and 177 females) aged between 7 and 104 years were analyzed. Ninety percent of the patients were older than 60 years. Mean follow-up was 4.6 years (range 1 to 9 years). Immediate Austin-Moore hip hemiarthroplasty in the elderly and screw fixation in younger patients rendered best results in the femoral neck fractures. Ender nailing in the elderly and angular plating or skeletal traction in the young proved most successful in trochanteric fractures.

Free-floating thrombi in the right heart: diagnosis, management, and prognostic indexes in 38 consecutive patients.

BACKGROUND: Floating right heart thrombi (FRHTS) are a rare phenomenon, encountered almost exclusively in patients with suspected or proven pulmonary embolism and diagnosed by transthoracic echocardiography. Their management remains controversial. METHODS AND RESULTS: We report on a series of 38 consecutive patients encountered over the past 12 years. Thirty-two patients were in NYHA class IV, 20 in cardiogenic shock. Echocardiography usually demonstrated signs of cor pulmonale: right ventricular overload (91.7% of the population), paradoxical interventricular septal motion (75%), and pulmonary hypertension (86. 1%). The thrombus was typically wormlike (36 of 38 patients). It extended from the left atrium through a patent foramen ovale in 4 patients. Pulmonary embolism was confirmed in all but 1. Mortality was high (17 of 38 patients) irrespective of the therapeutic option chosen: surgery (8 of 17), thrombolytics (2 of 9), heparin (5 of 8), or interventional percutaneous techniques (2 of 4). The in-hospital mortality rate was significantly linked with the occurrence of cardiac arrest. Conversely, the outcome after discharge was usually good, because 18 of 21 patients were still alive 47.2 months later (range, 1 to 70 months). CONCLUSIONS: Severe pulmonary embolism was the rule in our series of FRHTS (mortality rate, 44.7%). The choice of therapy had no effect on mortality. Emergency surgery is usually advocated. However, thrombolysis is a faster, readily available treatment and seems promising either as the only treatment or as a bridge to surgery. In patients with contraindications to surgery or lytic therapy, interventional techniques may be proposed.

Wavelength and atrial vulnerability: an endocavitary approach in humans.

If atrial vulnerability parameters are well defined, wavelength (WL) measurement (conduction velocity x refractory period), has never been assessed through an endocavitary electrophysiological exam. We investigated 30 patients (14 female, mean age 63.4 +/- 13 y.o.), 10 with paroxysmal atrial fibrillation (PAF group), 10 with ischemic cerebral injury (ICI group) by comparison with 10 controls (C group). The upper to lower right atrium conduction time and velocity were measured in the right atrium with a decapolar electrode catheter applied along the free wall. Others parameters correlated to atrial excitability were also taken into account: effective (ERP) and functional refractory periods (FRP); spontaneous or paced atrial electrogram (A1) or extrastimulated atrial electrogram (A2) widths, ERP/A2 ratio, provocative atrial testing. Measurements were taken in sinus rhythm and in 600-460 ms paced cycle lengths. If ERP, FRP, A1 widths are the same in the 3 groups, PAF and ICI groups have a significant increased conduction time and lower conduction velocity, leading to a shorter A1 WL during 600 and 460 ms paced rhythms (p < 0.05) and A2 WL during 460 ms paced rhythm. The provocative testing was positive in 60% of PAF and ICI groups, and there is a significant correlation between arrhythmia induction and 600 ms A1 WL or 460 ms A2 WL. This electrophysiological study suggests the possibility of an approach in humans of wavelength concept and proves the presence of correlation between a short wavelength and atrial spontaneous or induced arrhythmias. A no-arrhythmia band (A1 WL > 17 cm during 600 ms paced rhythm, A1 WL > 16 cm or A2 WL > 12 cm during 460 ms paced rhythm) and a fibrillation-band (A1 WL < 12 cm during 600 and 460 ms pacing, A2 WL < 7 cm during 460 ms pacing) can be defined. Therefore, the ICI group has the same atrial pattern as the AF group.

Distortion product otoacoustic emissions and sensorineural hearing loss.

As other types of otoacoustic emissions, distortion product otoacoustic emissions (DPOAEs) allow the exploration of the active cochlear mechanisms known to take place in the outer hair cell system. Most authors consider that 2f1-f2 DPOAEs are generated in a cochlear region corresponding to the geometric mean (GM) of the primary frequencies. To verify the relevance of this hypothesis in clinical practice, DPOAEs were recorded at seven different frequencies, ranging from 0.5 to 4 kHz, in 81 hearing-impaired patients and in 24 normally hearing subjects. To test the hypothesis that DPOAEs reflect the hearing threshold at the frequency of the GM rather than at the 2f1-f2 frequency, this study compares the 2f1-f2 frequency and the GM of the primaries to the frequency of hearing loss. DPOAEs can be used to explore a large range of frequencies, especially at high frequencies, but responses at low frequencies are less reliable due to noise contamination. Secondly, DPOAEs can be recorded in ears that have a hearing threshold as high as 65 dB HL at the frequency corresponding to the GM of the primaries. Finally, DPOAE recordings show frequency specificity: i.e., hearing loss at a specific frequency correlates best with DPOAEs whose GM of primary frequencies corresponds to the frequency of the hearing loss. However, this frequency specificity is still unsatisfactory and decreases as the levels of primaries increase above 60 dB SPL. Moreover, DPOAE amplitude is too variable to predict hearing loss at a particular frequency, whereas DPOAE threshold allows a correct prediction of abnormal auditory threshold in more than 80% of the cases at frequencies above 1 kHz.