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Background and Purpose: The purpose of this study was to reevaluate the usefulness of relative maximum signal drop (rMSD), as compared to relative cerebral blood volume (rCBV) and cerebral blood flow (rCBF), in dynamic susceptibility contrast magnetic resonance imaging (MRI)., Methods: Twenty-five patients (11 with cerebral gliomas and 14 with infarcts of middle cerebral arterial territories) were included. The rMSD values were measured from 83 regions of interest and compared with measurements from corresponding rCBV and rCBF maps., Results: In stroke patients, rMSD correlated strongly with rCBF (r = 0.96) but only fairly with rCBV (r = 0.69). The absence of an association between rMSD and rCBV was evident in regions of increased contrast bolus dispersion. In glioma patients, the correlation of rMSD with rCBF (r = 0.85) was similar to that of rMSD with rCBV (r = 0.80). The interparameter associations were well predicted by computer simulations., Conclusions: The authors conclude that rMSD is as useful as rCBF under a variety of pathophysiological conditions, whereas in conditions with normal mean transit time, such as brain tumors, rMSD provides equivalent blood volume information to rCBV. The simplicity of rMSD maps could lead to the increased use of perfusion-weighted MRI.

Glucose and insulin stimulate leptin gene expression in vitro and in vivo. To identify cis-elements that are responsible for the glucose and insulin effects, mouse 3T3-L1 adipocytes were transiently transfected with reporter constructs with serial deletions in mouse ob gene promoter. The cis-elements were identified with Gel mobility shift assays (GMSA), DNase I footprint assays and PCR mediated site-directed mutation assays. Transient transfections detected a negative cis-acting element, a glucose-responsive element (GLRE), and an insulin-responsive element (IRE) in the region from -1 719 bp to -1 452 bp of mouse ob gene. This region does not contain any known GLRE or IRE. GMSA identified a DNA binding protein which specifically binds a native probe prepared from mouse ob gene promoter (-1 719 bp/-1 452 bp), and the binding was repressed by glucose or insulin. DNase I footprint assays and PCR mediated site-directed mutations assays identified that the binding motif AGCAAAA, spanning -1 698 bp to -1 692 bp of the mouse ob gene promoter, was responsible for the effects of glucose and insulin on ob gene expression. These studies suggest that a negative cis-acting element is located between -1 719 bp and -1 452 bp of the mouse ob gene promoter, and glucose and insulin simulate mouse ob gene expression by repressing the binding of a transcription factor to this element. This element, AGCAAAA, spanning -1 698 bp to -1 692 bp is a novel GLRE and IRE.

Relative quantitation RT-PCR was used to investigate the regulation of leptin expression in 3T3-F442A adipocytes by glucose and insulin. The results showed that glucose and insulin stimulated the expression of leptin in 3T3-F442A adipocytes, but they did not act synergically. Over-high concentration of glucose suppressed the expression of leptin and the effect of insulin. The elevation of the expression of leptin was characterized with saturation. The concentration of glucose is very important for the regulation of leptin expression.

Objectives: To compare speech recognition performance in Chinese-speaking cochlear implant patients with a speech processor program selected by the clinical audiologist in Taiwan and with a new speech processor program based on the Washington University clinical procedure developed by Skinner et al., Study Design: Six adult Chinese-speaking patients implanted with the Nucleus cochlear implant system participated in this study., Methods: A fitting procedure developed in 1995 by Skinner et al. at Washington University School of Medicine was used to create a new speech processor program to optimize each patient's hearing in everyday life. Speech tests (vowels, consonants, tones, and words), sound-field thresholds, and a self-report questionnaire were used to evaluate each patient's performance with his or her previous speech processor program and a new one., Results: Four of the six patients had significant changes from the previous to the new speech processor program. These changes were associated with improvement in score on at least one speech test, more sensitive sound field thresholds, and reported improvement in some everyday listening situations on the questionnaire., Conclusions: These results suggest that use of this procedure with adult cochlear implantees may improve benefit in everyday life. Analysis of the speech test stimuli and patients' responses provides a basis for modification or creation of new Mandarin Chinese speech tests for preoperative and postoperative evaluation of adult cochlear implant patients.

The Wang tube was modified to improve in vitro semen manipulation, by adding another two racks to the anterior (posterior) wall of the low component of the Wang tube and supplying another four convex lenses symmetrical to those on the bottom wall. The former provides a slanted position leading to a complete real-time sperm separation image and benefiting low-quality sperm preparation when the modified Wang tube is turned on its side. The latter converses the microscope's light better and gives a clearer objective image.

Various sperm preparation techniques, swim-up and Percoll gradient, and the newly developed Wang's tube system, were evaluated for their ability to recover normal-chromatin sperm. Twenty human semen samples, collected by masturbation, were studied simultaneously with the three methods. Analysis by Acridine orange fluorescence test was performed on all samples. Pretreated semen contains 58 +/- 22% green sperm (fertile/normal). Treatment with Wang's tube system resulted in 99 +/- 1.0% green sperm; Percoll gradient, 78 +/- 11%; and swim-up technique, 72 +/- 15%. It would appear that Wang's tube system yields a high-quality sperm preparation with enough concentration, very active forward progression, and greatly improved sperm morphology, while containing normal-chromatin, double-stranded DNA.