颈内动脉接近完全闭塞时的处理

目的由于卒中风险随着狭窄严重程度的增加而升高，因此认为颈内动脉（ICA）接近闭塞患者的卒中风险很高。在现有的随机试验中，还没有专门针对这种情况进行探讨，因此其处理尚存在争汶。方法：对相关文献进行系统评价。结果：对ICA接近闭塞患者的处理还存在争议：一些学者支持进行干预，而另一些学者则认为存在风险或没有益处而反对进行干预。在ICA接近闭塞的有症状患者中进行一项比较外科治疗与最佳内科治疗的多中心前瞻性随机试验似乎非常困难，因为这类研究需要大量的患者。尽管如此，基于目前的证据，似乎很难拒绝手术治疗。结论：由于目前对ICA接近闭塞患者的最佳处理方案仍存在着争议，因此需要前瞻性观察性研究以证实其在有症状和无症状人群中的患病率以及相关的卒中风险。基于目前的证据，大多数医疗中心选择手术治疗，但它相对干内科治疗的特粱尚右待证章．     

Pneumococcal carriage amongst children in Adelaide, South Australia

Amongst 1267 healthy children 6 months to 4.5 years of age in Adelaide, the pneumococcal carriage rate from a single nasal swab sampling was 29% in the period 1980-1. Of 269 children, sampled monthly on five occasions, 91% carried a pneumococcus on one or more occasions: 55% carried a single type, 33% carried two types, 2% carried three types and 1% carried four types; 18% carried a pneumococcus on either 4 or 5 occasions. The commonest types encountered were types 6, 19 and 23 in that order, and these three types constituted 57% of the total: other common types (greater than 5% of the total) were types 14, 15 and 11, and the six commonest types constituted 77% of the total. Of these, types 6, 14, 19 and 23 commonly cause systemic disease in children; on the other hand types 11 and 15 cause disease infrequently. The number of strains showing antimicrobial drug resistance was low: on quantitative testing 0.7% of 291 isolates examined showed relative resistance to benzylpenicillin and 0.7% were resistant to tetracycline; 10.9% of 230 isolates examined showed resistance to co-trimoxazole; dual or multiple drug resistance was not detected, and all isolates tested were susceptible to chloramphenicol, erythromycin, lincomycin and rifampicin.     

CT demonstration of extraocular muscle atrophy

Two cases of CT-documented extraocular muscle atrophy are presented. Unilateral atrophy was observed in a patient with a lesion of the cavernous sinus. Atrophic extraocular muscles were noted bilaterally in a young woman with "ophthalmoplegia plus" (probable Kearns-Sayre syndrome).     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.