High-speed, high-frequency ultrasound, \u3ci\u3ein utero\u3c/i\u3e vector-flow imaging of mouse embryos

Real-time imaging of the embryonic murine cardiovascular system is challenging due to the small size of the mouse embryo and rapid heart rate. High-frequency, linear-array ultrasound systems designed for small-animal imaging provide high-frame-rate and Doppler modes but are limited in regards to the field of view that can be imaged at fine-temporal and -spatial resolution. Here, a plane-wave imaging method was used to obtain high-speed image data from in utero mouse embryos and multi-angle, vector-flow algorithms were applied to the data to provide information on blood flow patterns in major organs. An 18-MHz linear array was used to acquire plane-wave data at absolute frame rates ≥10 kHz using a set of fixed transmission angles. After beamforming, vector-flow processing and image compounding, effective frame rates were on the order of 2 kHz. Data were acquired from the embryonic liver, heart and umbilical cord. Vector-flow results clearly revealed the complex nature of blood-flow patterns in the embryo with fine-temporal and -spatial resolution

Geometric mismatch of pulmonary and aortic anuli in children undergoing the Ross procedure: Implications for surgical management and autograft valve function

AbstractBackground: There is often substantial mismatch between the diameters of the pulmonary and aortic anuli in young patients with systemic outflow tract disease. To implant the autologous pulmonary valve in the aortic position under such circumstances, it is necessary to adapt the geometry of the systemic outflow tract. The effects of such adaptations on autograft function in children are not well known. Methods: To determine factors predictive of autograft regurgitation, we analyzed 41 cases of children who have undergone the Ross procedure. The diameter of the pulmonary valve was greater (by at least 3 mm) than that of the aortic valve in 20 cases, equal (within 2 mm) in 12 cases, and less (by at least 3 mm) in nine cases, with differences ranging from +10 to –12 mm. In 12 patients with a larger pulmonary anulus, aortoventriculoplasty was used to correct the mismatch. In patients with a larger aortic anulus, the mismatch was corrected by gradual adjustment along the circumference of the autograft, rather than by tailoring of the native aortic anulus. Results: At follow-up (median 31 months), two patients had undergone reoperation on the neoaortic valve for moderate regurgitation. In the remaining 38 cases, autograft regurgitation was as follows: none or trivial in 30, mild in seven, and moderate in one. There was no correlation between regurgitation and age, geometric mismatch, or previous or concurrent procedures. Conclusions: Subtle technical factors that may result in distortion of the valve complex are probably more important determinants of autograft regurgitation than are indication for repair, geometric mismatch, or previous or concomitant outflow tract procedures. Significant mismatch of the semilunar anuli is not a contraindication to the Ross procedure in children. (J Thorac Cardiovasc Surg 1998;115:1255-63

Evaluation of Fetuses in the Preventive IVIG Therapy for Congenital Heart Block (PITCH) study

The recurrence rate of anti-SSA/Ro associated congenital heart block (CHB) is 17%. Reversal of 3rd degree block has never been achieved. Based on potential reduction of maternal autoantibody titers as well as fetal inflammatory responses, IVIG was evaluated as a preventative therapy for CHB

The ocular dose of ultraviolet radiation to outdoor workers

Ocular ultraviolet radiation (UVR) exposure was assessed in three occupational groups: fisherman, landscape workers and construction workers. The ratio of ocular exposure to ambient exposure was determined by placing UV-sensitive film (295-320 nm) between the eyes of the subjects and in a nearby open field. The mean ocular exposures varied between 2 and 17% of the ambient exposure on a horizontal surface, depending on whether subjects wore hats, the job performed and the time of year. Wearing a brimmed hat significantly reduced ocular exposure in all groups of subjects. Subjects working over more reflective surfaces had significantly higher ocular exposure. A seasonal effect on the ocular ambient exposure ratio (OAER) was also observed. These results are consistent with measurements of OAER in mannikin and measurements of surface reflectivity in this and previous studies. The results provide parameters which can be used in modeling ocular UVR exposure in epidemiological and clinical studies

Autoimmune Congenital Complete Heart Block: How Late Can It Occur?

Objective Maternal anti-Ro (SSA) and/or anti-La (SSB) antibodies are a risk factor for congenital complete heart block (CHB). Because detailed analysis of the incidence of CHB after 24 weeks of gestational age (GA) is lacking, we aimed to ascertain the risk of “later-onset” CHB among offspring of SSA/SSB-positive mothers in the published literature. Study Design Using search terms “neonatal lupus heart block” and “autoimmune congenital heart block” on PubMed and Ovid, we gathered prospective studies of SSA/SSB-positive mothers with fetal echo surveillance starting from before CHB diagnosis and retrospective cases of fetal CHB diagnosis after 24 weeks of GA (if there was prior normal heart rate) or after birth. Results Ten prospective studies included 1,248 SSA/SSB-positive pregnancies with 24 cases of CHB diagnosed during pregnancy (1.9%). Among these, three (12.5%) were after 24 weeks—at weeks 25, 26, and 28. Our retrospective studies revealed 50 patients with CHB diagnosis in late fetal life and neonatal period and 34 in the nonneonatal childhood period. An additional four cases were diagnosed after age 18 years. Conclusion Later-onset autoimmune CHB in offspring of SSA/SSB-positive mothers does occur. Our analysis suggests that prenatal surveillance should continue beyond 24 weeks of GA but is limited by inconsistent published surveillance data