Multimodal fetal transesophageal echocardiography for fetal cardiac intervention in sheep.

BACKGROUND: The overall performance of available mechanical intravascular ultrasound catheters for fetal transesophageal echocardiography during fetoscopic fetal cardiac interventions in sheep has been limited by radioelectronic interference, low system frame rates, and low acoustic outputs. Therefore, a more reliable device is desired for human fetoscopic surgical procedures. METHODS AND RESULTS: We assessed the potential of a newly available 10-French phased-array intravascular ultrasound catheter for multimodal fetal transesophageal echocardiography in 5 fetal sheep between 78 and 98 days of gestation (term, 145 to 150 d). The intravascular ultrasound catheter was easily inserted through the mouth into the esophagus in all 5 sheep fetuses (mean weight, 600 g), and it permitted high-quality 2D imaging of the fetal heart in vertical imaging planes that were validated by MRI. Color Doppler and pulsed Doppler imaging permitted clear assessment of fetal cardiovascular flows and recording of velocity-time integral tracings of the fetal heart and great vessels. The vertical imaging planes were particularly useful to demonstrate interventional material inside the fetal heart and great vessels. CONCLUSIONS: Our early experience with the phased-array intravascular ultrasound catheter indicates that multimodal fetal transesophageal echocardiography has now become possible in these smallest of patients.

Soft contact lens polymers: an evolution.

A review of patents and literature reveals an evolution in materials technologies. The evolution has been driven by an increased understanding of the physiological needs of the cornea, beginning with the first hydrogel lenses developed by Wichterle, followed by a variety of high water hydrogels. Oxygen transmission requirements have been addressed through the use of siloxane and fluorosiloxane containing hydrogels. An important development has been the appreciation of the importance of polymer phase morphology on lens movement on the eye. In parallel with these activities have come the advancements in materials suitable to high volume, low cost production necessary for today's daily disposable lenses.

Facial EMG responses to auditory stimuli.

Three studies were performed to investigate the effects of auditory stimuli (pure tones and environmental noise) of different intensities on surface EMG activity recorded over five facial muscle regions (M. frontalis lateralis, M. corrugator supercilii, M. orbicularis oculi, M. zygomaticus major, M. depressor anguli oris). The results show that with presentation of tones and noises of high intensity (> 85 dB) strong facial EMG reactions over muscles of the upper face (M. frontalis lateralis, M. corrugator supercilii, M. orbicularis oculi) were evoked. Among environmental noises of different valence but the same intensity, baby's crying evoked EMG reactions over facial muscles in the mouth region, possibly indicating that the subjects demonstrated expressions of dislike during this particular stimulation. It is also discussed whether facial EMG reactions to auditory stimulation of different intensities could be connected to changes in muscle tone of the middle ear muscles. The contraction of these muscles modulates sensitivity to auditory stimulation. Thus, facial EMG activity of the muscles of the upper face could serve as an indicator of sensitivity to external auditory stimuli. However, the evaluation of pleasant and unpleasant emotional reactions in response to auditory stimulation seems to be impossible.

The durability of bioprostheses in young people. Long-term results with intra- or extracardiac implanted porcine valves.

Forty two children and two young adults who were long term survivors of either intracardiac or extracardiac valve replacement with glutaraldehyde porcine valves form the basis of this report. The follow-up period varied from 6 months to 9 years. Ten of eleven intracardiac valves developed some dysfunction--the eleventh patient died from other causes. Of a total of 36 extracardiac valved conduits in the Rt side of the heart, four have needed replacement and an additional four will require replacement in due course. The probability of an event free performance of an intracardiac porcine valve is zero at 5 years. Four extracardiac valves there is in an 80% expectancy at 5 years and a 12% at 8 years of trouble free existence.

In vivo corrosion and corrosion protection of magnesium alloy LAE442.

The aim of this study was to investigate whether the extruded magnesium alloy LAE442 reacts in vivo with an appropriate host response and to investigate how an additional magnesium fluoride (MgF(2)) coating influences the in vivo corrosion rate. Forty cylinders were machined from extruded LAE442 and 20 of these were coated additionally with MgF(2) and implanted into the medial femur condyle of adult rabbits. Synchrotron-radiation-based X-ray computed micro-tomography (SRmicroCT) was used to quantitatively analyse corrosion non-destructively in vivo and comparisons were made to magnesium degradation rates based on area measurements of the remaining metal on uncalcified sections. Blood concentrations of the alloying elements were measured below toxicological limits. The MgF(2) layer was no longer detected after 4 weeks of implantation by particle-induced gamma emission, and the MgF(2) coating reduced the blood content of alloying elements during the first 6 weeks of implantation with no elevated fluoride concentration in the adjacent bone. Histopathological examinations of liver showed in 9 out of 40 cases minimal infiltrations of heterophil granulocytes of unknown origin (5 LAE442, 4 LAE442+MgF(2)). The kidneys were mainly regular in structure. The synovial tissue showed a granular cell infiltration as a temporary observation in the LAE442+MgF(2) group after 2 weeks. No subcutaneous gas cavities were observed clinically and on postoperative X-rays in all animals. All specimens were scanned by SRmicroCT at 2, 4, 6 and 12 weeks postoperatively before uncalcified sections were performed. All magnesium implants have been observed in direct bone contact and without a fibrous capsule. Localized pitting corrosion occurred in coated and uncoated magnesium implants. This study shows that the extruded magnesium alloy LAE442 provides low corrosion rates and reacts in vivo with an acceptable host response. The in vivo corrosion rate can be further reduced by additional MgF(2) coating.

LCS mobile-bearing total knee replacement. A 10-year's follow-up study.

INTRODUCTION: For the last three decades total knee arthroplasty surgery has been facing the renewed choice of using a traditional fixed-bearing design or a mobile-bearing system. A growing number of surgeons have elected to increase their use of mobile-bearing prostheses. We wanted to assess the reliability, in our hospital of this alternative choice. HYPOTHESIS: Fixed-bearing and LCS mobile-bearing knees exhibit comparable long-term clinical and radiographic results. MATERIAL AND METHODS: Between January 1994 and December 1996, 126 LCS prostheses (DEPUY) were implanted by the same operator in 101 patients (mean age was 70.0 years). The predominant underlying pathology was osteoarthritis (113 prostheses); the posterior cruciate ligament was retained in 30% of these cases which permitted a tibial tray implantation using a PCR type meniscal-bearing component; 78 prostheses were cemented; 116 prostheses included a patellar button: 46 of these resurfaced patella featured a cementless metal implant and a mobile-bearing polyethylene insert. Overall function was assessed using the SF-12 and IKS scores, and on the basis of patients' satisfaction rate. Patients' review process took place between 1st October 2006 and 1st December 2006. Of the 101 patients, 59 were alive, 39 were clinically examined and 20 completed a self-assessment questionnaire; 32 had died and 10 were lost to follow-up. The average age of the patients still alive was 78 years (79 years for those operated on for osteoarthritis, 67 years for those operated on for rheumatoid polyarthritis); Mean follow-up period at the time of this review was 11.4 years. Mean body mass index (BMI) was 30.8 kg/m(2). RESULTS: No early infection was observed. Early complications included instability in one case, stiffness in six cases and resolutive patellar pain in three cases. Six prostheses necessitated to be revised. In the 39 reviewed patients (52 prostheses), the mean IKS knee score was 78/100, (range, 20 to 100/100), mean functional score was 66/100 (range, 0 to 100/100). Mean mobility in flexion was 105.8 degrees (range, 20 degrees to 135 degrees). The SF-12 quality of life score was assessed in 39 of the operated patients. Mean physical score was 37 (range, 22.6 to 61.2); mean mental score was 47 (range, 23.1 to 62.3). Seventeen patients were very satisfied, 18 satisfied (these combined categories representing 90% of patients), three were partially satisfied and one was unsatisfied. Forty-three radiographs were performed in 36 patients at the time of the follow-up visit: 39 of them included an A-P, a lateral and a patellar view at 30 degrees of flexion. Thirty-nine readings were normal. A radiolucent line beneath the tibial component was observed on three radiographs. An asymptomatic patellar tilt was reported in one instance. Mean tibial slope was 8 degrees (range, 1 degree to 11 degrees). DISCUSSION: Statistical analysis of these results demonstrates a significant and long-lasting improvement in the clinical score, an early improvement (both in respect to functional score and mobility) with a late minor deterioration of the quality of this initial improvement; a poorly significant negative correlation between mobility and BMI. Despite a high satisfaction rate, it does not quite match that obtained with hip arthroplasty. No correlation was found between the observed results and patient gender, prosthesis fixation method, type of prosthesis (PCR meniscal-bearings versus rotating platform, posterior cruciate ligament retention versus sacrifice), tibial slope, limb axis, and selected patellar treatment options. CONCLUSION: The mobile-bearing prostheses achieve results at least as good as comparable ones reported in other series; demonstrate a very low revision rate in relation to wear damages; and tolerate insufficient axis deformity corrections. LEVEL OF EVIDENCE: Level IV. Therapeutic study.

Incontinentia pigmenti (Bloch-Sulzberger syndrome). A case report.

Incontinentia pigmenti is a rare genodermatosis with multiple manifestations affecting the skeletal, ocular, dental, and other tissues. More than 95% of reported cases occur in females, and more than 60% of reported cases involve some dental abnormality. A brief review of the literature and a case in a 7-year-old girl with the disease are presented.

The acute effect of sodium cellulose phosphate on intestinal absorption and urinary excretion of calcium in man.

Intestinal 47Ca absorption has been determined from blood and stool radioactivity after oral administration of the isotope in nine patients before and during cellulose phosphate treatment. Oral administration of 5 g cellulose phosphate concomitant with 47Ca in 100 mg "carrier" calcium as CaCl2 decreased 47Ca absorption by 80 per cent. Cellulose phosphate, 5 g three times daily, decreased urinary excretion of non-radioactive calcium by 47 percent. Urinary magnesium excretion decreased by 47 percent whereas urinary phosphorus excretion increased by 67%. Calcium and magnesium excretion in urine decrease because cellulose phosphate binds divalent cations within the GI tract. The increased phosphorus excretion is probably due to partial hydrolysis of the substance in the gut.

Fluoride and mineral redeposition in outermost layers of bovine enamel during surface softening.

Mineral and fluoride concentration changes in the outermost layers of bovine enamel (depth less than 1 micron) were measured after demineralization in unbuffered hydroxyethylcellulose gels of pH = 5.4 with an intrinsic fluoride concentration of about 0.02 ppm. A combination of two nuclear analytical techniques, Rutherford backscattering spectrometry (RBS) and proton-induced gamma ray emission spectrometry (PIGE) was applied to determine the Ca/P molar ratios and F depth profiles, respectively. When compared to deeper layers, a reduced loss of mineral content is observed for the depth range of about 0-0.1 micron corresponding well with a F concentration increase from about 500 to about 5,000 ppm in the same range. These findings are interpreted as a fluoride-induced partial remineralization of the superficial surface layer during an overall demineralization process.

Oxygen permeability of a new type of high Dk soft contact lens material.

Lotrafilcon A is a biphasic block-copolymer, comprising a highly permeable siloxane-based polymeric phase, coupled with a water phase (hydrogel phase). The high oxygen permeability of this material, and the fact that it is a hydrogel, places it outside the applicability of both the polarographic ISO standard and coulometric ISO draft standards for contact lens Dk determination. The oxygen permeability (Dk) and transmissibility (Dk/t) of lotrafilcon A lenses were determined by an adaptation of the standard coulometric method. Lenses with a thickness (t) range from 30 microns to over 300 microns were measured in a liquid-to-gas and a gas-to-gas configuration in an effort to combine features of the ISO (draft) standards to yield a valid measurement of the intrinsic material's oxygen transmission characteristics. The following results, for lotrafilcon A, are the mean values and SE for the oxygen permeability coefficient (Dk) determined at 34 degrees C: 140 +/- 2 barrer with water overlay (liquid-to-gas) at 2100 rpm stirring speed, 150 +/- 5 barrer with water overlay (liquid-to-gas) at "infinite" stirring speed, and 170 +/- 2 barrer without water overlay (gas-to-gas), where barrer = 10(-11) (mlO2.cm)/(sec.cm2.mm Hg). Clinical lenses produced from this material are expected to be in the 60 to 90 microns thickness range, with an average center thickness of 80 microns. Given that the Dkmaterial is greater than or equal to 140 barrers, for this material, a parallel sided lens of 80 microns central thickness would exhibit a lens transmissibility (Dk/t) of at least 170 x 10(-9) mlO2/(sec.cm2.mm Hg) at 34 degrees C. This transmissibility is well in excess of the 87 x 10(-9) mlO2/(sec.cm2.mm Hg) value postulated to be sufficient to prevent overnight lens-induced corneal swelling and places it in the hyper-permeable material category.