Hyperglycemia in the acute phase of stroke and stress response.

There are two main reasons that this is not always so in practice. The first is that the skull also has considerable effects on the geometry of the ultrasound beam, varying from a simple shortening of the focal distance (due to refraction and refocusing) to complete disintegration of the sample volume caused by irregularities of the inner bony surface ("split beam"). The first of these may possibly be compensated for by increasing the acoustic output of the instrument, but this will have no beneficial effect in the second case. The second reason is that attenuation in the cancel-lous tissue of the diploe, where this is present, is between 10 and 30 times as great, 7 and which has an even more destructive effect on the beam geometry. Osteoporotic changes in postmenopausal females cause a similar effect, 8 and neither can be rectified by increasing ultrasonic intensity. References 1. Eden A. Effect of emitted power on waveform intensity in trans-cranial Doppler. Rate of successful recording of blood flow signals in the middle cerebral artery using transcranial Doppler sonography. Response It is thought that the transcranial Doppler examination is useful for monitoring real-time changes of blood flow signals and screening for cerebrovascular diseases. Therefore, in our recent study, 1 we checked a success rate for recording Doppler signals from the middle cerebral artery (MCA) in Japanese subjects, and by increasing emitted power we attempted to overcome the problem of obtaining no signals in elderly females. For the adjustment of the emitted intensity, by learning Halsey's method 2 from a specialist at Medasonics who was in communication with Prof Halsey, we modulated only the amount of the electrical power to the transducer crystal to obtain the desired emitted power. As described in his reply to the Eden letter, 3-4 the term "power of N mW/cm 2 " used throughout our article should be understood to mean "that power that would result in an estimated in situ intensity of N mW/cm 2 ." As pointed out by Dr Eden, we mistakenly calculated the product of time and intensity, for safe recording, the exposure time at an emitted intensity that results in an in situ intensity of 400 mW/cm 2 should be limited to 71 seconds. In the majority of the subjects examined at higher emitted power, we finished the examination within 60 seconds, and fortunately any subjected to longer exposure time (from 70 to …