Application of contrast-enhanced sonography with time-intensity curve analysis to explore hypervascularity in Achilles tendinopathy by using a rabbit model.

OBJECTIVES: The purpose of this study was to investigate the ability of contrast-enhanced sonography in staging and grading hypervascularity in tendinopathic tissues by using a rabbit model. METHODS: Fourteen rabbits were injected with 100 and 50 µL of collagenase in their left and right Achilles tendons, respectively. The vascularity was assessed by non-contrast-enhanced and contrast-enhanced power Doppler sonography on day 0 (baseline) and days 1, 7, and 14 after collagenase injections. Color pixels within targeted areas were plotted according to time and analyzed by a curve-fitting method. RESULTS: Non-contrast-enhanced power Doppler sonography failed to differentiate vascularity at various stages or between bilateral tendons, whereas contrast-enhanced sonography showed that the peak color pixel amount reached its maximum on day 1 and declined over time in tendons treated with 100 µL of collagenase. A similar trend was observed in tendons receiving 50 µL of collagenase. For comparisons between bilateral tendons, higher vascularity was detected in those treated with more collagenase on day 1 or 7. Time-intensity curve analysis revealed rapid microbubble replenishment in both tendons during their initial phase after collagenase injections. CONCLUSIONS: Contrast-enhanced sonography discriminated the vascularity of various injury grades at different time points after collagenase injections. Time-intensity curve analysis detailed the hemodynamics in tendinopathic tissues, which helped differentiate vascularity in acute inflammatory from later degenerative phases.

Pulsed wave Doppler ultrasound is useful to assess vasomotor response in patients with multiple system atrophy and well correlated with tilt table study.

The study aim was to assess sympathetic vasomotor response (SVR) by using pulsed wave Doppler (PWD) ultrasound in patients with multiple system atrophy (MSA) and correlate with the tilt table study. We recruited 18 male patients and 10 healthy men as controls. The SVR of the radial artery was evaluated by PWD, using inspiratory cough as a provocative maneuver. The response to head-up tilt was studied by a tilt table with simultaneous heart rate and blood pressure recording. The hemodynamic variables were compared between groups, and were examined by correlation analysis. Regarding SVR, MSA patients exhibited a prolonged latency and less heart rate acceleration following inspiratory cough. Compared with the tilt table test, the elevation of heart rate upon SVR was positively correlated to the increase of heart rate after head-up tilt. The correlation analysis indicated that the magnitude of blood pressure drop from supine to upright was positively associated with the SVR latency but negatively correlated with the heart rate changes upon SVR. The present study demonstrated that blunted heart rate response might explain MSA's vulnerability to postural challenge. PWD may be used to predict cardiovascular response to orthostatic stress upon head-up tilt in MSA patients.

Dietary intake and growth deficits in Rett syndrome-A cross-section study.

Growth deficit is a common comorbidity and one of the supportive criteria in Rett syndrome (RTT). This study aimed to investigate the impact of dystonia, dietary intakes, and clinical severities on growth patterns in a Taiwanese cohort of RTT. We recruited 44 RTT patients with MECP2 mutation for analysis. For individuals ≤18 years of age, in comparison to the RTT-specific growth chart which comprised American RTT cohort, the body height was right-shifted to a higher percentile, whereas the body weight was left-shifted to a lower percentile. Furthermore, the body mass index was significantly decreased when compared to RTT-specific growth chart (p = 0.01). Higher degree of overall disease severity (odd ratio = 1.159; 95% CI = 1.063-1.264; p = 0.001) and hand use impairment (odd ratio = 2.017; 95% CI = 1.037, 3.921; p = 0.039) were associated with more severe growth patterns. All individuals had dystonia at certain variable degrees. The dystonia worsened with age (p < 0.001) but did not have significant impact on growth deficit. Most of our cohort had adequate protein (97.37%) and energy (58.97%) intakes. The fiber intakes were generally low, with about 38 (97.4%) individuals did not meet the daily reference intakes of fiber. The protein intake was significantly lower in individuals with severe growth deficit (p = 0.04). Our study shows that ethnicity should be considered when comparing RTT individuals' growth pattern to the RTT-specific growth chart. Further, disease severity, genotypes, and nutrition exert important impacts on RTT-growth pattern. LAY SUMMARY: Growth impairment is an important issue in Rett syndrome and the underlying patho-mechanism is multifactorial. Higher degree of overall disease severity and hand use impairment were associated with more severe growth pattern deficits. Although all individuals had dystonia at certain variable degrees and the dystonia worsened with age, but it did not have significant impact on growth deficit. Nutritional intakes may partially affect growth. Furthermore, ethnicity should be considered when comparing RTT individuals' growth pattern to the RTT-specific growth chart.