Stage based recipient and donor outcome in twin-to-twin transfusion syndrome treated by fetoscopic laser surgery using Solomon technique.

OBJECTIVE: To evaluate twin survival stratified by Quintero stage in patients with twin-to-twin transfusion syndrome (TTTS) after Solomon laser treatment. METHODS: Single center cohort of consecutive twin pregnancies treated with Solomon laser for TTTS. Preoperative Quintero stage, perioperative characteristics and obstetric factors were related to neonatal survival of the recipient and donor at discharge. Determinants of twin survival were evaluated using univariate, logistic regression and cumulative survival probability analyses. RESULTS: Of 402 twins with TTTS, 80 (19.9%) had stage I, 126 (31.3%) stage II, 169 (42%) stage III and 27 (6.7%) stage IV. Post laser TAPS or recurrent TTTS occurred in 19 (4.7%) patients and 11 (2.7%) required repeat laser. Preterm premature rupture of membranes occurred in 150 (37.3%) patients and median gestational age of delivery 32+1 weeks. In 303 (75.4%) both twins were alive at discharge; [66 (82.5%) in stage I, 101 (80.2%) in stage II, 114 (67.5%) in stage III and 22 (81.5%) in stage IV, p=0.062]. Compared to recipients, donor survival was only lower in stage III (155 (91.7%) recipients vs 118 (69.8%) donors, Chi square 24.685, p<0.0001). Larger intertwin size discordance and umbilical artery (UA) end-diastolic velocity (EDV) determined donor demise (Nagelkerke R2 0.38, P<0.001). Overall, spontaneous post laser donor demise accounted for the majority (39.5%) of all losses. Cumulative donor survival decreased from 92% to 65% with size discordance >30% and 48% when UA EDV was absent (p<0.001). CONCLUSION: Solomon laser achieves TTTS resolution and double survival in a high proportion of cases. Recipient and donor survival is comparable unless there is significant size discordance and placental dysfunction. This degree of unequal placental sharing, typically found in stage III, is the primary factor preventing double survival due to a higher rate of donor demise. This article is protected by copyright. All rights reserved.

Characterization of a major nucleoplasmin-like germinal vesicle protein which is rapidly phosphorylated before germinal vesicle breakdown in Spisula solidissima.

Oocytes of the surf clam, Spisula solidissima, are arrested at the G2/M boundary of meiotic prophase I. At this stage, they possess a prominent germinal vesicle (GV), comprising about 25% of the total oocyte volume, in which pools of mRNAs and proteins that facilitate the rapid rounds of cell division which occur early in development are stored. We have isolated and characterized an abundant 49-kDa phosphoprotein, localized exclusively to the GV, which shares properties with nucleoplasmin. Like nucleoplasmin, this 49-kDa protein is a heat-stable, highly acidic phosphoprotein [containing over 32% (Glx + Asx) with an isoelectric point of about 4.0] and is soluble in 80% ammonium sulfate. In contrast to the pentameric nucleoplasmin, much of this protein is isolated as a disulfide-linked multimer which migrates at 120 kDa. In addition, a fraction of the 49-kDa protein is associated via disulfide bonds to a doublet of 42-kDa proteins. In vivo, this 49-kDa protein is phosphorylated prior to germinal vesicle breakdown (GVBD) and at 5 min after oocyte activation rapidly incorporates 32P to 60% of maximal level, suggesting that this protein plays a major role in the cascade of events which lead to oocyte activation and GVBD.

Translational regulation of histone synthesis in the sea urchin strongylocentrotus purpuratus.

The pattern and schedule of histone synthesis in unfertilized eggs and early embryos of the sea urchin Strongylocentrotus purpuratus were studied using two-dimensional gel electrophoresis. After fertilization there is an abrupt change in the pattern of histone variant synthesis. Although both cleavage-stage (CS) variants. However, after fertilization, both CS and alpha messages are translated. Since alpha histone mRNA isolated from unfertilized eggs can be translated in vitro, the synthesis of alpha histone subtypes appears to be under translational control. Although the synthesis of alpha subtypes is shown here to occur before the second S phase after fertilization, little or no alpha histone is incorporated into chromatin at this time. Thus, early chromatin is composed predominantly of CS variants probably recruited for the most part from the large pool of CS histones stored in the unfertilized egg.

Electrophoretic analysis of the stored histone pool in unfertilized sea urchin eggs: quantification and identification by antibody binding.

A maternal store of histones in unfertilized sea urchin eggs is demonstrated by two independent criteria. Stored histones are identified by their ability to assemble into chromatin of male pronuclei of fertilized sea urchin eggs in the absence of protein synthesis, suggesting a minimum of at least 25 haploid equivalents for each histone present and functional in the unfertilized egg. In addition, electrophoretic analysis of proteins from acid extracts of unfertilized whole eggs and enucleated merogons reveals protein spots comigrating with cleavage stage histone standards, though not with other histone variants found in later sea urchin development or in sperm. Quantification of the amount of protein per histone spot yields an estimate of several hundred haploid DNA equivalents per egg of stored histone. The identity of some of the putative histones was verified by a highly sensitive immunological technique, involving electrophoretic transfer of proteins from the two-dimensional polyacrylamide gels to nitrocellulose filters. Proteins in amounts less than 2 x 10(-4) micrograms can be detected by this method.