Stroke in coronary artery bypass graft surgery: an analysis of the CASS experience. The participants in the Coronary Artery Surgery Study.

An analysis of the Coronary Artery Surgery Registry (CASS) was performed to determine the occurrence of stroke after coronary artery bypass surgery in patients entered into the Coronary Artery Surgery Study Registry. Of the 10,098 patients having coronary artery bypass surgery at the Coronary Artery Surgery Study participating sites during the period July 1974 through May 1979, a total of 348 patients (or 3.4%) sustained a stroke during the first year after coronary bypass surgery. Fifty-nine strokes occurred on the day of surgery, and an additional 129 strokes occurred during hospitalization for coronary bypass surgery. Thus, 188 patients (1.9%) of the entire surgical group sustained a stroke during initial hospitalization for coronary artery bypass surgery. Logistic regression analysis was used to predict stroke on the day of surgery, during the hospitalization for surgery, and during the first year after surgery. The most powerful predictors of stroke on the day of coronary artery bypass surgery were: 1) older age (n = less than 0.0001); 2) use of alpha-adrenergic drugs after bypass (n = 0.0001); and 3) longer duration of cardiopulmonary bypass (n = 0.002). For those strokes occurring at least 1 day after coronary artery bypass but during the initial hospitalization, age and duration of cardiopulmonary bypass were the most powerful predictors of stroke. An analysis of predictors of stroke within 1 yr after hospital dismissal for initial coronary bypass surgery revealed that the most powerful predictor was a history of previous cerebrovascular disease (n less than 0.0001) and a history of hypertension (n less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)     

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.      

Cryopreservation of human oocytes: a review of current problems and perspectives

It is well recognized that the ability to cryopreserve unfertilizedhuman oocytes would make a significant contribution to infertilitytreatment. However, despite considerable interest, very fewsuccessful pregnancies have arisen from cryopreserved oocytesafter thawing, insemination and transfer of the subsequent embryo.The reasons for this lack of progress may well result from adearth of information on how the various biophysical changesduring a cryopreservation regimen affect human oocyte function.Recently, fundamental studies on the effects of cooling, membranepermeability, cryoprotectant addition and ice formation havebeen performed on human oocytes by a number of groups, and theseform the basis of the current review. It is likely that successfulhuman oocyte cryopreservation will only follow once these factorsare fully understood, but the existing base of knowledge shouldprovide a platform for further improvements in the techniquescurrently employed.