Asfotase alfa treatment for 1 year in a 16 year-old male with severe childhood hypophosphatasia.

We describe the clinical outcome of asfotase alfa therapy in a 16-year-old boy with severe childhood hypophosphatasia (HPP), who began therapy at age 15 years. The patient was diagnosed with HPP at age 2 years when he presented with genu varum and premature loss of primary teeth. He had a history of multiple fractures requiring 16 orthopedic surgeries with rod and pin placement in his lower extremities. He had chronic skeletal pain and used cane to ambulate with great difficulty. His height Z score at age 15 years was - 5. He had severe scoliosis and deformity of both legs. Bone radiograph showed hypomineralization and characteristic "tongues" of radiolucency in the distal radius and ulna. His serum alkaline phosphatase level was stable, with elevated serum pyridoxal 5'-phosphate and urine phosphoethanolamine, consistent with HPP. He was started on asfotase alfa 2 mg/kg given subcutaneously thrice weekly. He had marked clinical improvement in mobility with no report of pain after 3 months of treatment. At 6 month, he walked without cane and participated in outdoor activities with peers. Bone radiograph at 6 months showed striking improvement in previous radiolucent areas. At 9 months, his annualized growth velocity was 9.5 cm/year, while growth velocity of arm span was 12 cm/year. However, at 12 months, he was noted to have worsening scoliosis from 60 degrees before therapy to 110 degrees, with a slight decrease in height, necessitating a spinal fusion surgery. In conclusion, treatment with asfotase alfa significantly improved physical function, pain, overall quality of life, and skeletal radiographic findings in this patient. Close monitoring for progression of scoliosis in adolescents with HPP treated with asfotase alfa is recommended.

Renal cortical ischemia in rabbits revealed by contrast-enhanced power Doppler sonography.

OBJECTIVE: Our goals were to describe and quantify redistribution of renal cortical blood flow during systemic hypotension in rabbits using contrast-enhanced power Doppler sonography and to explore the feasibility of creating real-time regional blood flow maps of the kidney. MATERIALS AND METHODS: Mild, moderate, and severe systemic hypotension (70%, 50%, and 40% of baseline measurements, respectively) were induced by controlled exsanguination in nine anesthetized rabbits. Sagittal power Doppler sonograms of the kidney were obtained during and after i.v. injection of 0.2 ml per kilogram of body weight of an experimental microbubble-based contrast agent. Doppler sonograms were analyzed for anatomic distribution of contrast agent and changes in mean pixel intensity over time. Cortical time-intensity curves were drawn and the area under the curve was compared with regional renal blood flow as measured by radiolabeled microspheres using linear regression in eight of the nine rabbits during graded hypotension. RESULTS: Graded hypotension resulted in increasing thickness of the nonperfused peripheral cortex (p < .001 by analysis of variance) with preservation of deeper cortical flow on enhanced Doppler sonograms. Other changes included decreased peak enhancement ratios and area under the curve values (p < .0001) and increased time to peak enhancement for cortex (p < .01). We found a strong correlation between cortical area under the curve and regional renal blood flow (r = .86, p < .0001). These changes were not shown without contrast enhancement. CONCLUSION: Peripheral cortical perfusion is disproportionately affected during systemic hypotension. Contrast-enhanced power Doppler sonography shows potential for depicting changes in regional renal blood flow in real time and without radiation.

Menière symptoms induced by an otologic implant during MR.

A patient who had had sacculotomy with placement of a stainless steel sacculotomy tack 20 years earlier experienced vertigo and auditory sensations during MR imaging. The safety of these prosthesis in MR is questionable. A simple method of determining ferromagnetic interaction is proposed.