Fetal macrosomia and management of delivery.

During the period 1988-1966, 737 pregnancies, in which the infant birth weight was > or = 4000 grams were studied. During the same period there were 11,631 newborns, and 6.3% of them were infants with a birth weight > or = 4000 grams. Normal vaginal delivery occurred in 583 cases (79.1%), vacuum extraction in 24 cases (3.3%) and caesarean section in 130 cases (17.6%). Regarding the caesarean section, 38 (29.2%) of them were elective and 92 (70.8%) were done in different periods of the labour. In these macrosomic babies perinatal death never occurred, but different pathological neonatal outcomes were observed and the majority of these were clavicle abruptions (39 cases: 5.3%). Maternal morbidity observed in the 607 (82.4%) cases with vaginal delivery is characterized by: 60 cases (9.8%) of vaginal and perineal tears, 4 cases (0.6%) of cervical tears, and 2 cases (0.3%) of pubic symphysis traumatic diastasis. Shoulder dystocia is the most likely outcome in fetal macrosomic delivery; for this reason we considered the diagnostic and therapeutic management of this obstetrical complication. Because the normal outcome of neonatal births actually encourages the preference for normal vaginal delivery, we concluded that mothers with macrosomic fetuses can safely be managed expectantly unless there is a high maternal and fetal risk.

[Fetal macrosomia and mode of delivery]. / Megalosomia fetale e modalità del parto.

During the period 1988-1993 the route of delivery in 482 infants with birth weight > or = 4000 grams was studied. Normal vaginal delivery occurred in 396 (82.1%) cases, vacuum extractor in 8 (1.6%) cases and caesarean section in 78 (16.1) cases. Elective induction of labor with oxytocin and/or amniotomy was carried out in 25 cases of macrosomia. Perinatal death and shoulder dystocia never occurred in these macrosomic babies, but clavicles abruption (27 cases), cephalohaematoma (2 cases), shoulder-bladehaematoma (1 case) and birth brachial palsy (1 case) were observed. Because, in our experience, elective induction of labor increased the operative delivery rate (caesarean section, vacuum extractor), we conclude that mothers with macrosomic fetuses can safely be managed expectantly unless there is a indication for induction or caesarean section.

Characterization and cloning of two Rhizobium leguminosarum genes coding for glutamine synthetase activities.

We have demonstrated that Rhizobium leguminosarum strain LPR1105 contains a heat stable and a heat labile glutamine synthetase (EC 6.3.1.2) activity similar to those described for other Rhizobiaceae. Most of the activity is heat stable when this strain is grown on glutamine as sole nitrogen source, but most is heat labile when grown on nitrate. Using a gene bank of R. leguminosarum DNA we have isolated two clones, which code for heat stable (p7D9) and heat labile (p4F7) glutamine synthetase activity, by complementing the glutamine auxotrophy of Klebsiella pneumoniae glnA mutants. Cross-hybridization of p7D9 with a fragment of the glnA gene of K. pneumoniae was observed, but no cross-hybridization between p7D9 and p4F7 was found. Since these two regions hybridize to genomic DNA of R. leguminosarum they are probably the structural genes for GSI and GSII, and the availability of these genes will make it possible to test this hypothesis. Clone p4F7 complements an ntrC+ but not an ntrC K. pneumoniae glnA mutant, suggesting that the ntrC gene is required for the complementation of the glutamine auxotrophy by this plasmid.

Isolation of human glucose-6-phosphate dehydrogenase (G6PD) cDNA clones: primary structure of the protein and unusual 5' non-coding region.

Glucose-6-phosphate dehydrogenase (G6PD) is an ubiquitous enzyme which by determining the NADPH level has a crucial role in NADPH-mediated reductive processes in all cells (1). The structural gene for G6PD, Gd, is X-linked in mammals and on the basis of its expression in many tissues, it can be regarded as a typical "housekeeping" gene (2). Over 300 variants of the protein are known, many of which have deficient enzyme activity. Nearly 100 of these variants are polymorphic in various populations (3). The mammalian enzyme is a homodimer or a homotetramer with a subunit molecular weight of approximately 56000 daltons (4). Here we report the isolation of cDNA clones from HeLa cells, SV40-transformed human fibroblasts, human placenta and human teratocarcinoma cell lines. These clones have enabled us to sequence the entire coding region of Gd. Thus, the entire amino acid sequence of human G6PD is provided for the first time. This work is the first step for structural analysis of G6PD variants and for an understanding of the biological features of this enzyme at the molecular level.

Prediction of the secondary structure of the carboxy-terminal third of rat thyroglobulin.

A secondary structure prediction has been made using the available primary sequence data of the proposed carboxy-terminal of rat thyroglobulin. The model predicts 22% alfa-helix, 28% beta-structure and 17% beta turns. Out of the 8 possible carbohydrate acceptor-sites (Asn-x-Ser/Thr), 3 (residues 136, 368, 782) are associated with peptide sequences which favour the formation of beta-turn or loop-structures and are located in high hydrophilic regions. The entire sequence is predicted to be made up of two domains: one of them is highly structured, contains the hormonogenic sites, a cluster of tyrosines and at least one carbohydrate acceptor site.

The sequence of 967 amino acids at the carboxyl-end of rat thyroglobulin. Location and surroundings of two thyroxine-forming sites.

The entire rat thyroglobulin mRNA sequence (about 8500 nucleotides) has been cloned in five recombinant plasmids containing overlapping cDNA inserts. The 3' end of the mRNA is precisely defined by the poly (A) tail found in the furthest 3' end clone. Evidence that most of the 5' end is cloned come from size considerations and from a primer extension experiment. At the 3' end of the mRNA only one long open reading frame is present in the sequence of 3018 nucleotides that has been established. In the deduced protein sequence we have localized two thyroxine-forming sites in a region containing a high concentration of tyrosine residues.

Computer programs for the characterization of protein coding genes.

Computer programs, implemented on an Univac II00/80 computer system, for the identification and characterization of protein coding genes and for the analysis of nucleic acid sequences, are described.