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Bo Lei

Publications and source records attributed to Bo Lei.

21 records · Page 2Linked to original sources

The ERG of guinea pig (Cavis porcellus): comparison with I-type monkey and E-type rat.

We have been in search of an alternate species for the monkey to study the effects of drugs on the I-type photopic electroretinogram (ERG) response that is typically seen in the cone-rich retina of the primate. The guinea pig has two types of cones, one of which contains a middle-wavelength sensitive pigment otherwise found only in Old World primates. We studied the Ganzfeld electroretinogram (ERG) of the guinea pig in relation to monkey and rat ERGs to learn whether the guinea pig might be a good animal model to study the 'primate-like' cone ERG. The guinea pig scotopic ERG was similar to other mammal ERGs and was not electronegative when fully dark-adapted. We saw no evidence of a negative-going scotopic threshold response (STR). The guinea pig photopic ERG a-wave is larger than that of the rat but much smaller than the primate a-wave, and it lacked a phasic d-wave. PDA eliminated guinea pig photopic a-wave and caused the OFF-response to long stimuli to invert polarity, as seen in monkey but not in rat. The guinea pig overall shows a weak I-type response and may be a useful substitute for primate in some studies of the photopic ERG.

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Use of a self-designed bladder controller for restoring bladder function in paraplegic dogs.

OBJECTIVE: To evaluate the results of a self-designed bladder controller for restoring micturition function in paraplegic dogs. METHODS: The spinal cords of 4 dogs were transected above the cone. Electrodes were implanted in S2 bilaterally and connected to the subcutaneous receivers for external activation. Microsurgical technique was employed to perform dorsal rhizotomy of S1-3 intradurally. The dogs were stimulated daily to observe micturition. Urodynamic testing and vesicography were performed. RESULTS: All the dogs acquired micturition under the control of electric stimulation, with urine volume 80-140 ml per time. The mode of micturition was post-stimulus voiding. Vesicography revealed that the bladder was filled well and the bladder neck was open in the micturition course of electric stimulation. Residual urine volume was 15-20 ml. Urodynamic testing found that the bladder pressure and intraurethral pressure increased simultaneously, but when the intraurethral pressure was greater than the bladder pressure, no micturition occurred. The pressure decreased to baseline rapidly and the bladder pressure decreased slowly between two bursts. Micturition occurred when the bladder pressure was greater than the intraurethral pressure. CONCLUSIONS: The self-designed bladder controller together with a sacral deafferentation procedure can restore micturition function of paraplegic dogs.

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