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Despite extensive investigation, a cause-and-effect relationship between varicocele and male infertility has not been fully proven. We investigated the effect of a unilateral varicocele on both testes. Spermatogenesis in the rats with a surgically induced left varicocele was evaluated 5 weeks postoperatively by measurement of testicular weight, flow cytometric DNA analysis and evaluation of the mean seminiferous tubular diameter (MSTD). In rats with varicoceles, the testicular weight, the percentage of haploid cells and the MSTD were decreased in both testes in contrast to sham-operated rats. There was a greater decrease on the left side. These results suggest that unilateral varicocele may impair spermatogenesis in both testes, with the impairment being greater on the ipsilateral side.

The Project Authorization Request (PAR) for the IEEE P1900.4 Working Group (WG), under the IEEE Standards Coordinating Committee 41 (SCC41) was approved in December 2006, leading to this WG being officially launched in February 2007 [1]. The scope of this standard is to devise a functional architecture comprising building blocks to enable coordinated network-device distributed decision making, with the goal of aiding the optimization of radio resource usage, including spectrum access control, in heterogeneous wireless access networks. This paper introduces the activities and work under progress in IEEE P1900.4, including its scope and purpose in Sects. 1 and 2, the reference usage scenarios where the standard would be applicable in Sect. 4, and its current system architecture in Sect. 5. © 2008 The Institute of Electronics, Information and Communication Engineers.

Udgivelsesdato: 1999-Aug Tinnitus is associated with a wide variety of disorders in the auditory system. Whether generated peripherally or centrally, tinnitus is believed to be associated with activity in specific cortical regions. The present study tested the hypothesis that these cortical centers subserve the generation, perception and processing of the tinnitus stimulus and that these processes are suppressed by lidocaine and masking. Positron emission tomography was used to map the tinnitus-specific central activity. By subtracting positron emission tomography images of regional cerebral blood flow distribution obtained during suppression of the tinnitus from positron emission tomography images obtained during the habitual tinnitus sensation, we were able to identify brain areas concerned with the cerebral representation of tinnitus. Increased neuronal activity caused by tinnitus occurred predominantly in the right hemisphere with significant foci in the middle frontal and middle temporal gyri, in addition to lateral and mesial posterior sites. The results are consistent with the hypothesis that the sensation of tinnitus is associated with activity in cortical regions functionally linked to subserve attention, emotion and memory. For the first time, the functional anatomy of conditions with and without the habitual tinnitus sensation was obtained and compared in the same subjects.