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: This was a single-center study at Johns Hopkins Center for Fetal Therapy, investigating a cohort of consecutive twin pregnancies treated with the Solomon laser technique for TTTS. Preoperative Quintero stage, perioperative characteristics and obstetric factors were investigated in relation to neonatal survival of the recipient and donor twins at discharge. Determinants of twin survival were evaluated using univariate logistic regression and cumulative survival probability analyses. RESULTS: Of 402 pregnancies with TTTS that underwent Solomon laser treatment, 80 (19.9%) were diagnosed with Quintero Stage-I TTTS, 126 (31.3%) with Stage II, 169 (42.0%) with Stage III and 27 (6.7%) with Stage IV. Post-laser twin anemia polycythemia sequence or recurrent TTTS occurred in 19 (4.7%) patients and 11 (2.7%) required repeat laser surgery. Preterm prelabor rupture of membranes occurred in 150 (37.3%) patients and median gestational age at delivery was 32 + 1 weeks. In 303 (75.4%) patients, both twins were alive at discharge; 67/80 (83.8%) were Stage I, 101/126 (80.2%) were Stage II, 113/169 (66.9%) were Stage III and 22/27 (81.5%) were Stage IV (P = 0.062). Donor twin survival was lower than that of recipients in cases with Stage-III TTTS (118/169 (69.8%) vs 145/169 (85.8%) (χ2 = 26.076, P < 0.0001)). Higher intertwin size discordance and absent or reversed umbilical artery (UA) end-diastolic velocity (EDV) were associated with donor demise (Nagelkerke R2, 0.38; P < 0.001). Overall, spontaneous post-laser donor demise occurred in 53 (39.6%) patients, accounting for the majority of all losses. Cumulative donor survival decreased from 92% to 65% when intertwin size discordance was >30% and to 48% when UA-EDV was absent or reversed (P < 0.001). CONCLUSIONS: The Solomon laser technique achieves TTTS resolution and double twin survival in a high proportion of cases. Recipient and donor survival is comparable unless there is significant intertwin size discordance and placental dysfunction. This degree of unequal placental sharing, typically found in Stage-III TTTS, is the primary factor preventing double survival due to a higher rate of donor demise. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

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.