INFLUENCE OF ULTRASOUND ON THE PERCUTANEOUS-ABSORPTION OF NICOTINATE ESTERS

The influence of ultrasound on the percutaneous absorption of three nicotinate esters was investigated in 10 healthy volunteers in a double-blind placebo controlled crossover clinical trial. Using a specially designed experimental protocol, the effect of continuous output ultrasound (at frequency 3.0 MHz and intensity 1.0 W/cm2 for 5 min) on the percutaneous absorption of methyl, ethyl, and hexyl nicotinates, from gel bases, was investigated. A placebo control, involving massage with each of the gels, without ultrasound for 5 min, was also incorporated. The pharmacodynamic parameter of vasodilation caused by the nicotinates was used to monitor the percutaneous absorption of the drugs. Laser Doppler velocimetry, a noninvasive optical technique, was used to measure vasodilation of the cutaneous vessels within the treatment site. Ultrasound treatment led to enhanced vasodilator response to the nicotinates, therefore indicating an enhancement of their percutaneous absorption. These agents may prove to be useful compounds in examination of the mechanism of action of phonophoresis.

INTRAVASCULAR ANTI-IGE CHALLENGE IN PERFUSED LUNGS - MEDIATOR RELEASE AND VASCULAR PRESSOR-RESPONSE

Intravascular application of goat anti-rabbit immunoglobulin E (IgE) was used to stimulate parenchymal mast cells in situ in perfused rabbit lungs. Sustained pulmonary arterial pressure rise was evoked in the absence of lung vascular permeability increase and lung edema formation. Early prostaglandin (PG) D2 and histamine release into the perfusate was documented, accompanied by more sustained liberation of cysteinyl leukotrienes (LT), LTB4, and PGI2. The quantities of these inflammatory mediators displayed the following order: histamine > cysteinyl-LT > PGI2 > LTB4 > PGD2. Pressor response and inflammatory mediator release revealed corresponding bell-shaped dose dependencies. Cyclooxygenase inhibition (acetylsalicylic acid) suppressed prostanoid generation, increased LT release, and did not substantially affect pressor response and histamine liberation. BW755 C, a cyclo- and lipoxygenase inhibitor, blocked the release of cysteinyl-LT and markedly reduced the liberation of the other inflammatory mediators as well as the pressor response. The H-1-antagonist clemastine caused a moderate reduction of the anti-IgE-provoked pressure rise. We conclude that intravascular anti-IgE challenge in intact lungs provokes the release of an inflammatory mediator profile compatible with in situ lung parenchymal mast cell activation. Pulmonary hypertension represents the predominant vascular response, presumably mediated by cysteinyl-LT and, to a minor extent, histamine liberation.

Diagnosis of common bile duct stones by intravenous cholangiography:prediction by ultrasound and liver function tests compared with endoscopic retrograde cholangiography

Routine intravenous cholangiography using the safer contrast medium, meglumine iotroxate, may be a useful investigation prior to laparoscopic cholecystectomy for the detection of suspected common bile duct stones. We compared this with endoscopic cholangiography.

Neonatal Ultrasound Results Following Very Preterm Birth Predict Adolescent Behavioral and Cognitive Outcome

This study investigated the association between different neonatal ultrasonographic classifications and adolescent cognitive, educational, and behavioral outcomes following very preterm birth. Participants included a group of 120 adolescents who were born very preterm (33 weeks of gestation), subdivided into three groups according to their neonatal cerebral ultrasound (US) classifications: (a) normal (N = 69), (b) periventricular hemorrhage (PVH, N = 37), and (c) PVH with ventricular dilatation (PVH + DIL, N = 14), and 50 controls. The cognitive functions assessed were full-scale IQ, phonological and semantic verbal fluency, and visual-motor integration. Educational outcomes included reading and spelling; behavioral outcomes were assessed with the Rutter Parents' Scale and the Premorbid Adjustment Scale (PAS). Adolescent outcome scores were compared among the four groups. A main effect for group was observed for full-scale IQ, Rutter Parents' Scale total scores, and PAS total scores, after controlling for gestational age, socioeconomic status and gender, with the PVH + DIL group showing the most impaired scores compared to the other groups. The current results demonstrate that routine neonatal ultrasound classifications are associated with later cognitive and behavioral outcome. Neonatal ultrasounds could aid in the identification of subgroups of children who are at increased risk of neurodevelopmental problems. These at risk subgroups could then be referred to appropriate early intervention services.

Preferences for a third-trimester ultrasound scan in a low-risk obstetric population: a discrete choice experiment

Objective: Establish maternal preferences for a third-trimester ultrasound scan in a healthy, low-risk pregnant population.

Design: Cross-sectional study incorporating a discrete choice experiment.

Setting: A large, urban maternity hospital in Northern Ireland.

Participants: One hundred and forty-six women in their second trimester of pregnancy.

Methods: A discrete choice experiment was designed to elicit preferences for four attributes of a third-trimester ultrasound scan: health-care professional conducting the scan, detection rate for abnormal foetal growth, provision of non-medical information, cost. Additional data collected included age, marital status, socio-economic status, obstetric history, pregnancy-specific stress levels, perceived health and whether pregnancy was planned. Analysis was undertaken using a mixed logit model with interaction effects.

Main outcome measures: Women's preferences for, and trade-offs between, the attributes of a hypothetical scan and indirect willingness-to-pay estimates.

Results: Women had significant positive preference for higher rate of detection, lower cost and provision of non-medical information, with no significant value placed on scan operator. Interaction effects revealed subgroups that valued the scan most: women experiencing their first pregnancy, women reporting higher levels of stress, an adverse obstetric history and older women.

Conclusions: Women were able to trade on aspects of care and place relative importance on clinical, non-clinical outcomes and processes of service delivery, thus highlighting the potential of using health utilities in the development of services from a clinical, economic and social perspective. Specifically, maternal preferences exhibited provide valuable information for designing a randomized trial of effectiveness and insight for clinical and policy decision makers to inform woman-centred care.

Inter-observer agreement in evaluating the anterior chamber angle by ultrasound biomicroscopy

Purpose. To determine the agreement between observers in estimating the configuration of the human anterior chamber angle (ACA) using ultrasound biomicroscopy (UBM). Methods. Two masked clinicians used UBM images to estimate, in 41 eyes, the configuration of the ACA, especially (1) the position of contact between the peripheral iris and the inside of the eye wall, (2) the angularity of the approach to the ACA, and (3) the curvature of the peripheral iris. Agreement between observers was evaluated by the kappa statistic. Results. Inter-observer agreement in assessing the iris insertion (kappa = 0.79), angular width (Kappa = 0.95), and the peripheral iris curvature (kappa = 0.84) was high. Conclusions. The agreement between observers in evaluating the anterior chamber angle configuration by UBM was excellent.

Increasing the size of a small peripheral iridotomy widens the anterior chamber angle:An ultrasound biomicroscopy study

Purpose: A peripheral iridotomy (PI) is the treatment of choice for pupillary block. In this study we investigated the effect of enlarging the size of a small PI on the anterior chamber angle in patients with angle closure using ultrasound biomicroscopy (UBM). Patients and Methods: Patients who had been treated with laser peripheral iridotomy for angle closure and were identified to have a small patent PI (<100 µm) with still appositionally closed anterior chamber angle were selected prospectively. The anterior chamber angle was assessed using UBM. The angle opening distance 500 µm from the scleral spur (AOD500) as well as the anterior and posterior chamber depth (ACD and PCD) 1000 µm from the scleral spur was measured. In addition, the ACD/PCD ratio was calculated. Afterwards, the PI was enlarged using an Nd: YAG laser and the UBM measurements were repeated as described above. Results: Six eyes of six patients were examined. After the enlargement of the PI the average AOD500 increased from 109 µm (±36) to 147 µm (±40) (p

Agreement between clinical and ultrasound biomicroscopy findings in different types of glaucoma

Purpose. To evaluate agreement between clinical examination (slit lamp examination and gonioscopy) and ultrasound biomicroscopy (UBM) in characterizing various features of the anterior chamber angle and adjacent structures. Methods. Twenty-eight patients (51 eyes) with open angle glaucoma (14), closed angle glaucoma (4), narrow angle and/or plateau iris (10), who had undergone UBM between March 94 and September 95 were studied. Evaluated parameters included angle width, iris configuration and presence of angle closure. The UBMs were reviewed in a masked fashion. Results. In 87.8% of cases there was agreement (within 10 degrees) between gonioscopic and UBM estimates of angle width. In all cases with greater than 10 degrees difference (12.2%) the angle size estimated by UBM was less than that estimated clinically. Iris configuration was graded identically in 51% of cases; the majority of disagreements (76.1%) occurred in cases graded as "regular" by gonioscopy and as "steep" by UBM. Angle closure was judged to be present more frequently by UBM. Conclusions. UBM and gonioscopy do not necessarily yield identical values for angle width, iris configuration, and presence of angle closure.

Ultrasound biomicroscopy in deep sclerectomy

Purpose: To evaluate by ultrasound biomicroscopy (UBM) the anatomical characteristics and the intraocular pressure (IOP) lowering mechanisms of deep sclerectomy after long-term follow-up. Methods: In all, 22 eyes of 21 consecutive patients who had deep sclerectomy were examined by UBM. Several UBM variables were prospectively evaluated, including the presence and maximum length and height of the intrascleral space, the minimum thickness of residual trabeculo-Descemet membrane (TDM), the presence and type of subconjunctival filtering bleb, and the presence of other possible drainage sites, for example suprachoroidal. Surgical success was considered to be achieved when the IOP was

Ultrasound biomicroscopy in infantile glaucoma

Background: Glaucoma in infants has many causes. Evaluation of the anatomy of the anterior segment of eyes with infantile glaucoma may help to determine the pathogenesis of an infant's disease and influence therapeutic decisions. Methods: Eleven eyes of six infants with glaucoma were evaluated with ultrasound biomicroscopy (UBM) to evaluate the anatomic characteristics and relationships of the anterior segment structures. Results: The anterior chamber angle, iris, lens, ciliary body, and posterior chamber angle could be imaged in detail. Elongated and anteriorly placed ciliary processes were noted in all eight eyes with trabeculodysgenesis. There were no apparent anomalies in the trabecular meshwork, or anterior chamber. In three eyes with dense corneal opacities, ultrasound biomicroscopy showed severe anterior segment disorganization and thin central corneas with posterior corneal excavation. Conclusions: Ultrasound biomicroscopy is a useful non-invasive method for evaluating infants with glaucoma in cases with corneal opacities. This information can help in surgical planning for glaucoma management.

Intraobserver and interobserver agreement in evaluating the anterior chamber angle configuration by ultrasound biomicroscopy

Purpose: To determine the intra- and interobserver agreement in assessing the configuration of the human anterior chamber angle using ultrasound biomicroscopy (UBM). Methods: Two masked clinicians used ubm images to estimate, in 41 eyes, (a) the position of contact between the peripheral iris and the inside of the eye wall, (b) the angular size of the anterior chamber angle (ACA), and (c) the curvature of the peripheral iris. Both observers, masked to the previous results, examined the same images in a second session. Agreement was evaluated using the unweighted ? statistic. Results: Intraobserver agreement in assessing the iris insertion, angular width, and the iris curvature was high (range of ? values, 0.83-0.92). Interobserver agreement in evaluating the level of iris insertion (? = 0.79), the angular width (? = 0.95), and the iris curvature (? = 0.84) was also high. Conclusion: The agreement within the same observer and between observers in evaluating the ACA configuration by UBM was excellent.