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Friedreich's ataxia is the first known autosomal recessive disease caused by an unstable trinucleotide expansion mutation. The most frequent mutation is expansion of a GAA repeat in the first intron of gene X25. We studied transmission of the expanded GAA repeat in 37 Friedreich's ataxia pedigrees and analysed blood and sperm alleles in eight patients. We showed intergenerational instability in 84% of the alleles with an overall excess of contractions. Both contractions and expansions of the GAA repeat occurred in maternal transmission with a stronger tendency to expand for smaller repeats and to contract for longer repeats. Paternally transmitted alleles contracted only. Parental age and the intergenerational change in expansion size were directly correlated in maternal transmission and inversely in paternal transmission. The size of the GAA expansion was slightly lower in patients than heterozygous carriers. Sperm analysis confirmed the tendency to contract of paternal alleles, which was more marked with ageing. The degree of contraction of the GAA repeat in sperm was much higher than that found in intergenerational transmission and was directly related to the repeat size. A blood expanded allele reverted to normal size in the sperm of one patient. This study suggests the existence of different mutational mechanisms in Friedreich's ataxia alleles, which occur both pre- and post-zygotically.  相似文献   
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The patients with highly damaged renal functions following extracorporeal circulation (ECC) were reviewed. Markers such as serum and urine creatinine (SCr, UCr), blood urea nitrogen (BUN), alpha 1-microglobulin in urine (as a marker of renal tubular function, abbreviated as U alpha 1-m), microalbumin in urine (as a marker of renal glomerular function, abbreviated as UA1b) were measured in each cases. Twenty patients were selected with the maximum value of U alpha 1-mover 60 micrograms/dl during or after ECC. The patients were classified into three groups according to preoperative value of alpha 1-m index (alpha 1-m index (I) = U alpha 1-m/UCr x 100 mg/g Cr), and Albumin index (Albumin index (I) = UA1b/UCr x 100 mg/g Cr). Group I (n = 13); alpha 1-m I > 10 and, Alb I > or = 50 (abnormal value of tubular and glomerular function), Group II (n = 3); alpha 1-m I < or = 10, Alb I > or = 50 (abnormal value of glomerular function), Group III (n = 4); alpha 1-m I < or = 10, Alb I < 50 (normal value of tubular and glomerular function). Six patients in Group I required postoperative hemodialysis (HD) and one patient in Group II. No one required HD in Group III. These facts suggest that preoperative damage of tubular and glomerular functions may become prolonged or irreversible damages may occur after operation. HD is required frequently in patients with alpha 1-m I level over 500 mg/g Cr, especially continuous HD may be needed in patient with alpha 1-m I level over 1000 mg/g Cr.  相似文献   
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In this paper, we propose two new types of dual-pole double-throw (DPDT) switch GaAs JFET monolithic microwave integrated circuits (MMICs) for digital cellular handsets. These ICs have the excellent characteristics of low insertion loss and high power handling capability, even with a low control voltage by stacking three JFETs with shallow Vp and using a novel bias circuit using p-n junction diodes. One DPDT switch IC has two shunt FET blocks and can achieve high isolation without external parts. An insertion loss less than 0.6 dB and isolation over 25 dB up to 2 GHz were achieved. P1dB was about 35 dBm even with a control voltage of 0/3 V. Another DPDT switch IC utilizes parallel resonance of external inductors and parasitic capacitance between the drain and the source of the OFF-state FETs. By attaching 15 nH inductors, for example, the IC exhibited an insertion loss as low as 0.4 dB, an isolation of better than 40 dB at 1.5 GHz, a bandwidth of about 400 MHz for 20 dB isolation, and P1dB of about 34 dBm with the 0/3 V control  相似文献   
95.
The dynamics of ovarian follicular development and the pattern of pituitary and ovarian hormone concentration were investigated during the luteal phase in ewes with autotransplanted ovaries. The follicles were measured by ultrasound and samples of ovarian and jugular venous blood were collected at intervals of 12 h. Blood samples were collected before and after a GnRH challenge (250 ng GnRH, i.v.) to allow the determination of basal and LH-stimulated concentration of ovarian steroids. Throughout the luteal phase, large antral follicles developed in three waves, each of which was preceded by a rise in the concentration of FSH (P < 0.05). The concentrations of oestradiol and androstenedione in the unstimulated and LH-stimulated samples were similar (P > 0.05) during the first 3 days of the luteal phase but differed thereafter, with the LH-stimulated being significantly higher than the basal concentrations (P < 0.05). In the first wave of follicular development the changes in follicular size were accompanied by an increase in the concentration of ovarian steroids and inhibin A. During the second follicular wave, although changes in follicle diameter were similar to the first wave (P > 0.05), the basal concentration of ovarian steroids and inhibin A remained unchanged throughout the period of emergence and demise of the large follicles. These results confirm that the development of large antral follicles during the luteal phase of the sheep occurs in successive waves that are associated with fluctuations in FSH secretion. However while the results strongly suggest that fluctuations in both inhibin A and oestradiol secretion control FSH during the first follicular wave, the cause of the FSH fluctuations associated with waves two and three is unclear. Final resolution of this issue may need to await the development of a specific assay for dimeric inhibin B.  相似文献   
96.
In the present study, we attempted to determine the extent to which an anterior capsulorrhexis carried out during cataract surgery contracts postoperatively. The size of the continuous curvilinear capsulorrhexis (CCC) was measured at the end of surgery and at the final follow-up examination in 52 eyes of 40 patients who underwent phacoemulsification/aspiration and implantation of an intraocular lens (IOL) with 6-mm optics. Images obtained by video during surgery and by slit-lamp microscopy were used to determine the CCC size with reference to the optics of the IOL. The average CCC size was 5.0 mm at the end of surgery; it contracted to 4.4 mm by the final postoperative examination. The contraction of the anterior capsule progressed rapidly in the first 50 days following surgery and then gradually thereafter. The extent of contraction was greater in older patients. The smaller the CCC size immediately after surgery, the more rapidly it contracted. The size of the capsulorrhexis contracted an average of 22% following cataract surgery. The contraction rate tended to be higher in older patients. The results suggest that the capsulorrhexis carried out in cataract surgery for elderly patients should be sufficiently large, but not larger than the optics size of the IOL.  相似文献   
97.
This is a case report of a 43-year-old woman who received a transplant for end-stage liver disease due to hereditary hemorrhagic telangiectasia and fibropolycystic liver disease. This is an uncommon association of two autosomal-dominant conditions with defined genetic and molecular defects. The liver showed extensive vascular malformations of arteries and veins as well as telangiectasia and fibrosis. In addition, there were cystically dilated ducts containing inspissated bile and extensive von Meyenburg complexes. This case raises interesting questions about the possible relationship of these genes and their gene products, both of which are related to cell-matrix interactions and are strongly associated with blood vessels, one of them being expressed on endothelial cells and the other being developmentally important in blood vessels.  相似文献   
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