Skeletal effects of low-intensity pulsed ultrasound on the ovariectomized rodent

Growing evidence supports low-intensity pulsed ultrasound (US) as an osteogenic mechanical stimulus. Its effects on isolated bone cells and on fractured bone are established. However, its effects on osteoporosis are not clear. This study examined US effects on ovariectomy (OVX) induced bone changes within the rodent hindlimb (distal femur and proximal tibia), and on normal bone in animals following sham-OVX. Animals were exposed to daily unilateral active-US and contralateral inactive-US for 12 weeks. Bone status was assessed using dual energy X-ray absorptiometry and histomorphometry. Ovariectomy resulted in significant bone changes. Low-intensity pulsed US did not influence these changes. These results suggest that the US dose introduced may not be a beneficial treatment for osteoporosis, and that intact bone may be less sensitive to US than fractured bone and isolated bone cells. This may relate to the biophysical mechanisms of action of US, US-bone interactions and tissue level processes taking place.

Aberrant protective force generation during neural provocation testing and the effect of treatment in patients with neurogenic cervicobrachial pain

Background: Observation of the occurrence of protective muscle activity is advocated in assessment of the peripheral nervous system by means of neural provocation tests. However, no studies have yet demonstrated abnormal force generation in a patient population. Objectives: To analyze whether aberrations in shoulder girdle-elevation force during neural tissue provocation testing for the median nerve (NTPTI) can be demonstrated, and whether possible aberrations can be normalized following cervical mobilization. Study Design: A single-blind randomized comparative controlled study. Setting: Laboratory setting annex in a manual therapy teaching practice. Participants: Twenty patients with unilateral or bilateral neurogenic cervicobrachial pain. Methods: During the NTPTI, we used a load cell and electrogoniometer to record continuously the shoulder-girdle elevation force in relation to the available range of elbow extension. Following randomization, we analyzed the immediate treatment effects of a cervical contralateral lateral glide mobilization technique (experimental group) and therapeutic ultrasound (control group). Results: On the involved side, the shoulder-girdle elevation force occur-red earlier, and the amount of force at the end of the test was substantially, though not significantly, greater than that on the uninvolved side at the corresponding range of motion. Together with a significant reduction in pain perception after cervical mobilization, a clear tendency toward normalization of the force curve could be observed, namely, a significant decrease in force generation and a delayed onset. The control group demonstrated no differences. Conclusions: Aberrations in force generation during neural, provocation testing are present in patients with neurogenic pain and can be normalized with appropriate treatment modalities.

Therapeutic efficacy of zeta-cypermethrin pour-on for the treatment of biting and sucking lice in cattle under field conditions

Objective To assess the efficacy of zeta-cypermethrin pour-on to control cattle lice. Design Five field trials in south-eastern Australia. Procedure Zeta-cypermethrin pour-on, deltamethrin pour-on and pour-on vehicle were applied to groups of 10 cattle. Lice were counted before treatment and 14, 28, 42 and 56 days after treatment. Results Zeta-cypermethrin pour-on given at 2.5 mg/kg was equivalent to, or marginally more effective than a deltamethrin pour-on at 0.75 mg/kg. It eliminated B bovis and H eurysternus and gave good control of L vituli and S capillatus. Zeta-cypermethrin at 1 mg/kg gave good control of B bovis and H eurysternus but was not satisfactory against L vituli and S capillatus. Conclusion Zeta-cypermethrin pour-on, given at 2.5 mg/kg, is an effective treatment for cattle lice control. Zeta-cypermethrin, and other synthetic pyrethroid pour-ons, are the treatment of choice to control B bovis.

Comparison of calcaneal ultrasound and DXA in young women

Purpose: The purpose of the study was to assess quantitative ultrasound (QUS) parameters in collegiate female gymnasts, a population whose training incorporates high-impact loading, which is particularly osteogenic, and to determine the discriminative capacity of this relatively new radiation-free technique compared with bone densitometry in a young healthy population. Methods: We studied 19 collegiate gymnasts and 23 healthy controls undergoing regular weight-bearing activity, matched for age (gymnasts 19.2 +/- 1.2, controls 19.9 +/- 1.6 yr) and body weight (gymnasts 56.7 +/- 3.7, controls 57.7 +/- 7.8 kg). QUS parameters of the calcaneus (broadband ultrasound attenuation (BUA), bone velocity (BV), and speed of sound (SOS)) were measured by a Walker Sonix UBA 575+. Bone mineral density (BMD; g.cm(-2)) of the lumbar spine, hip (Femoral neck, trochanter. Ward's triangle) and whole body was assessed by dual energy x-ray absorptiometry (DXA, Hologic QDR 1000/W). Data analysis included unpaired two-tailed Student's t-tests, analysis of variance, Pearson product-moment, and Spearman rank-order correlations. Results: Regional and whole body BMD of gymnasts was greater than controls (P < 0.001), with the difference being 7-28%. Average QUS parameters of the right and left calcaneus were also higher (P < 0.001) in the gymnasts. BUA, BV, and SOS were significantly (P < 0.001) correlated to each bone site with r = 0.54-0.79. Analysis of receiver operating characteristic (ROC) curves indicated no significant difference in sensitivity and specificity for QUS and DXA measures. Conclusions: These results indicate that QUS parameters of the calcaneus are higher in young women gymnasts compared to individuals who undergo regular weight-bearing activity and that QUS parameters are able to discriminate between these two groups in a similar manner as does regional and whole body BMD.

Initial results of ultrasound screening for aneurysm of the abdominal aorta in Western Australia: relevance for endoluminal treatment of aneurysm disease

Background. Increased life expectancy in men during the last thirty years is largely due to the decrease in mortality from cardiovascular disease in the age group 29-69 yr. This change has resulted in a change in the disease profile of the population with conditions such as aneurysm of the abdominal aorta (AAA) becoming more prevalent. The advent of endoluminal treatment for AAA has encouraged prophylactic intervention and fuelled the argument to screen for the disease. The feasibility of inserting an endoluminal graft is dependent on the morphology and growth characteristics of the aneurysm. This study used data from a randomized controlled trial of ultrasound screening for AAA in men aged 65-83 yr in Western Australia for the purpose of determining the norms of the living anatomy in the pressurized infrarenal aorta. Aims. To examine (1) the diameters of the infra-renal aorta in aneurysmal and non-aneurysmal cases, (2) the implications for treatment modalities, with particular reference to endoluminal grafting, which is most dependent on normal and aneurysmal morphology, and (3) any evidence to support the notion that northern Europeans are predisposed to aneurysmal disease. Methods. Using ultrasound, a randomized control trial was established in Western Australia to assess the value of a screening program in males aged 65-83 yr, The infra-renal aorta was defined as aneurysmal if the maximum diameter was 30 mm or more. Aortic diameter was modelled both as a continuous tin mm) and as a binary outcome variable, for those men who had an infra-renal diameter of 30 mm or more. ANOVA and linear regression were used for modelling aortic diameter as a continuum, while chi-square analysis and logistic regression were used in comparing men with and without the diagnosis of AAA. Findings. By December 1998, of 19.583 men had been invited to undergo ultrasound screening for AAA, 12.203 accepted the invitation (corrected response fraction 70.8%). The prevalence of AAA increased with age from 4.8% at 65 yr to 10.8% at 80 yr (chi (2) = 77.9, df = 3, P<0.001). The median (IQR) diameter for the non-aneurysmal group was 21.4 mm (3.3 mm) and there was an increase (<chi>(2) = 76.0, df = 1, P<0.001) in the diameter of the infra-renal aorta with age. Since 27 mm is the 95th centile for the non-aneurysmal infra-renal aorta, a diameter of 30 mm or more is justified as defining an aneurysm. The risk of AAA was higher in men of Australian (OR = 1.0) and northern European origin (OR = 1.0, 95%CL: 0.9. 1.2) compared with those of Mediterranean origin (OR = 0.5, 99%CL: 0.4, 0.7). Conclusion. Although screening has not yet been shown to reduce mortality from AAA. these population-based data assist the understanding of aneurysmal disease and the further development and use of endoluminal grafts for this condition. (C) 2001 Published by Elsevier Science Ltd on behalf of The International Society for Cardiovascular Surgery.

Ultrasound evaluation of polymer gel dosimeters

A new method for the evaluation of radiotherapy 3D polymer gel dosimeters has been developed using ultrasound to assess the significant structural changes that occur following irradiation of the dosimeters. The ultrasonic parameters of acoustic speed of propagation, attenuation and transmitted signal intensity were measured as a function of absorbed radiation dose. The dose sensitivities for each parameter were determined as 1.8 x 10(-4) s m(-1) Gy(-1), 3.9 dB m(-1) Gy(-1) and 3.2 V-1 Gy(-1) respectively. All parameters displayed a strong variation with absorbed dose that continued beyond absorbed doses of 15 Gy. The ultrasonic measurements demonstrated a significantly larger dynamic range in dose response curves than that achieved with previously published magnetic resonance imaging (MRI) dose response data. It is concluded that ultrasound shows great potential as a technique for the evaluation of polymer gel dosimeters.

Ultrasound imaging in rehabilitation: Just a fad?

Real-time ultrasound imaging provides an unrivalled opportunity to observe muscle morphology and contraction. This has obvious potential for clinical practice and the tool is beginning to be adopted into physical therapy. The implementation of ultrasound imaging has become particularly widespread for assessment of size and activation of deep trunk muscles, such as the transversus abdominis and lumbar multifidus, and for assessment of the pelvic floor muscles. The obvious benefit for these areas is that ultrasound permits observation of muscles that are difficult to assess through noninvasive means. This realization of the clinical potential of ultrasound imaging has been paralleled by an explosion of clinical and physiological research. However, despite the enthusiasm for utilization of ultrasound imaging, a question that is critical to address is whether ultrasound can actually improve rehabilitation.