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PubMed1994

Fetal biophysical profile score in triplet pregnancies.

Assessment of the last fetal biophysical profile score (BPS) (excluding nonstress test) prior to delivery was carried out in 35 triplet pregnancies. A normal BPS was found to be reliable in predicting nondistressed fetuses in triplets (specificity, 94.9%), while an equivocal BPS (6/8) had low sensitivity (14.3%) in predicting distressed fetuses. Two stillbirths were not detected by ultrasound prior to delivery. No correlation was found between the BPS and either neonatal morbidity or perinatal mortality. The BPS could not differentiate between distressed and nondistressed fetuses in the same pregnancy. These results suggest that an equivocal BPS has limited value in predicting fetal distress in triplet pregnancies, but a normal one could be used to predict nondistressed fetuses.

Adult↗
PubMed1996

Delayed interval delivery in a triplet pregnancy: a case report.

The incidence of multiple pregnancies is increasing due to a surge in the availability of assisted conception techniques. Spontaneous miscarriages, preterm labour and delivery are common complications of multiple pregnancies. In rare circumstances where the leading foetus has been expelled and the rest remain in utero, it is conventional to augment uterine activity to expel the rest of the uterine contents so as to avoid sepsis. Conservative management in such circumstances might allow for foetal lung maturity in the remaining foetuses, but there is limited experience in the world literature. We present a case of conservative management of a triplet pregnancy with early loss of the leading triplet. The delivery interval was 34 days and both remaining triplets survived without any sequelae.

Adult↗
PubMed1997

[Short-term outcome of infants from triplet pregnancies. A series of 45 pregnancies].

OBJECTIVE: To evaluate outcome of triplets pregnancies. METHODS: A retrospective study about children of 45 triplet pregnancies which occurred spontaneously or after assisted reproductive technologies. All were managed by the same obstetrical and pediatric team. RESULTS: Mean birth weight was 1800 g and 26% of children were very low birth weights (< 1500 g). There was no difference in the mean Apgar score of pH between first, second and third infant. Neonatal and perinatal mortality rate were respectively 60 and 75%. Incidence of respiratory distress syndrome was 29%, hyaline membrane disease 11%, intraventricular hemorrhage (grade 4) 1.3%, necrotizing enterocolitis 10.5% and bronchopulmonary dysplasia 4%. Only 10% of the infants were not hospitalized and were kept by their mother. 38% of the newborns had to be hospitalized in a Neonatal Intensive Care Unit, with a mean stay of 6 days. At birth, 34% of the babies required intubation for artificial ventilation. CONCLUSIONS: The main problem of triplet pregnancies is high prematurity.

Apgar Score↗
PubMed2003

Reduction of the number of fetuses for women with triplet and higher order multiple pregnancies.

BACKGROUND: When couples are faced with the dilemma of a higher order multiple pregnancy there are three options. Termination of the entire pregnancy has generally not been acceptable to women, especially for those with a past history of infertility. Attempting to continue with all the fetuses is associated with inherent problems of preterm birth, survival and long term morbidity. The other alternative relates to reduction in the number of fetuses by selective termination. The acceptability of these options for the couple will depend on their social background and underlying beliefs. This review focused on reduction in the number of fetuses. OBJECTIVES: To assess a policy of multifetal reduction with a policy of expectant management of women with a triplet or higher order multiple pregnancy. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register (30 September 2002), the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2002), and PubMed (to 30 September 2002). SELECTION CRITERIA: Randomized controlled trials with reported data that compared outcomes in mothers and babies who were managed expectantly with outcomes in women who underwent selective fetal reduction of a triplet or higher order multiple pregnancy. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. MAIN RESULTS: There were no randomised controlled trials identified. REVIEWER'S CONCLUSIONS: There are insufficient data available to support a policy of pregnancy reduction procedures for women with a triplet or higher order multiple pregnancy. While randomised controlled trials will provide the most reliable evidence about the risks and benefits of fetal reduction procedures, reduction in the number of fetuses by selective termination may not been acceptable to women, especially for those with a past history of infertility. The acceptability of this option, and willingness to undergo randomisation will depend on the couple's social background and beliefs, and consequently, recruitment to such a trial may prove exceptionally difficult.

Female↗
PubMed2007

Effects of SCA1, MJD, and DPRLA triplet repeat polymorphisms on cognitive phenotypes in a normal population of adolescent twins.

The expansion of unstable trinucleotide CAG repeat polymorphisms of a number of genes causes several neurodegenerative disorders with decreased cognitive function, the severity of the disorder being related to allele length at the triplet repeat locus. While the effects of repeat length have been well studied in clinical samples, there has been little investigation of the effects of triplet repeat variation in the normal range for these genes. We have, therefore, examined linkage and association for three CAG triplet repeat markers (Spinocerebellar Ataxia Type 1, SCA1; Machado-Joseph Disease, MJD; Dentatorubro-pallidoluysian Atrophy, DRPLA) to assess their contribution to variation in cognitive ability (IQ, reading ability, processing speed) in a normal, unselected sample of adolescent twins (248 dizygotic (DZ) sibling pairs, aged 16 years). Association tests, performed in Mx and QTDT, showed a consistent positive association of SCA1 with Arithmetic (P = 0.04). While association was supported between SCA1 and Cambridge reading scores and between DRPLA and inspection time, results were inconsistent across software packages. Given the number of statistical tests performed, it is unlikely that trinucleotide repeat variation in the normal range for these genes influences variation in normal cognition.

Adolescent↗
PubMed1989

Generation of triplet carbonyl compounds during peroxidase catalysed reactions.

Peroxidases, acting as oxidase upon appropriate substrates, generate carbonyl compounds in the electronically excited triplet state. These excited species can transfer energy as demonstrated by the appearance of the acceptor fluorescence or induced photochemistry concomitant with the disappearance of phosphorescence. Chlorophyll, an efficient emissive acceptor, either naturally present or artificially incorporated into organelles and cells, allows the in situ detection of biologically generated excited species. With neutrophils, the myeloperoxidase promoted acetone phosphorescence can readily be detected. In other cases, e.g. triplet benzaldehyde, it is possible to observe emission from lipid peroxidation initiated by the triplet carbonyl compound.

Acetaldehyde↗
PubMed2006

Use of triplet excited States for the study of drug binding to human and bovine serum albumins.

The triplet excited states of (S)- and (R)-flurbiprofen (FBP) have been used as reporters for the microenvironments experienced within the binding sites of human and bovine serum albumins. Regression analysis of triplet decay provides valuable information on the degree of protection that these excited states are afforded from attack by a second FBP molecule, oxygen, or other reagents. The multiexponential fitting of these decays can be satisfactorily correlated with the distribution of the drug among the two binding sites and its presence as the noncomplexed form in the bulk solution. This assignment has been confirmed by using (S)-ibuprofen or capric acid as selective site II replacement probes. Triplet lifetimes and site occupancy are sensitive to the type of serum albumin employed (human versus bovine). Finally, the binding behaviour of (S)- and (R)-FBP exhibits little stereoselectivity.

Animals↗
PubMed2007

Triplet repeat in the Repin1 3'-untranslated region on rat chromosome 4 correlates with facets of the metabolic syndrome.

BACKGROUND: Congenic and subcongenic rat strains confirmed the quantitative trait loci (QTLs) for facets of the metabolic syndrome between 60.53 and 77.11 Mb on chromosome 4. The analysis of candidate genes in this region favoured the replication initiator 1 (Repin1) characterized by a SNP in the coding region and a triplet repeat (TTT) in the 3'-untranslated region (3'UTR). METHODS: We analysed nine rat strains (BB/OK, SHR, F344, BN, DA, LEW, hHTg, WOKW, and their founders WOK-F) and four wild rats on DNA (sequencing) and RNA level (gene expression in blood, liver, subcutaneous, and epididymal adipocytes). In addition, the rats were phenotypically characterized in order to link the rat phenotype to genotype differences in the QTL on chromosome 4. RESULTS: Wild rats were heterozygous for the SNP (C/T), whereas all the inbred strains were homozygous. The shortest triplet repeat was found in SHR (5) and the highest was found in hHTg and WOKW (11), which developed metabolic disorders. The repeat number correlated with most phenotypic traits studied. Using linear multiple regression analysis with repeat size as the dependent variable and considering all the data of this study, it was clearly demonstrated that not only VLDL cholesterol and serum insulin but also the expression of Repin1 in the liver is significantly associated with the repeat size of the 3'UTR. CONCLUSIONS: It is concluded that the triplet repeat expansion in 3'UTR is involved in metabolic alterations as found in hHTg and WOKW rats and that the functional unknown gene, Repin1, could be a novel candidate gene for the development of facets of the metabolic syndrome.

3' Untranslated Regions↗
PubMed2003

Anomalously fast migration of triplet-repeat DNA in capillary electrophoresis with linear polymer solution.

We investigated the capillary electrophoretic behavior of single-stranded DNA fragments in methylcellulose solution, and found that triplet-repeat DNA showed anomalously faster mobilities than DNA markers with random sequence. Through the further study on the electrophoretic data, reptation model is proven appropriate to describe the migration of DNA under our experimental conditions. Accordingly, with the equations based on reptation theory, we could obtain the persistence length of DNA fragments and find that these values of triplet-repeat DNAs are larger than that of DNA markers with random sequence, which means the former DNAs are less flexible than the latter ones when they migrate in the electric field. This phenomenon is supposed to result from the characteristic higher-order structure formed by GC base pairs within triplet-repeat DNA, which is further proven by the resumed migration order in accordance with DNA size when the denaturant is added into the sieving matrix.

Base Sequence↗
PubMed2005

Computational analyses of singlet-singlet and singlet-triplet transitions in mononuclear gold-capped carbon-rich conjugated complexes.

Density functional theory and CASSCF calculations have been used to determine equilibrium geometries and vibrational frequencies of metal-capped one-dimensional pi-conjugated complexes (H3P)Au(C[triple chemical bond]C)(n)(Ph) (n = 1-6), (H3P)Au(C[triple chemical bond]CC6H4)(C[triple chemical bond]CPh), and H3P--Au(C[triple chemical bond]CC6H4)C[triple chemical bond]CAu--PH3 in their ground states and selected low-lying pi(pi)* excited states. Vertical excitation energies for spin-allowed singlet-singlet and spin-forbidden singlet-triplet transitions determined by the time-dependent density functional theory show good agreement with available experimental observations. Calculations indicate that the lowest energy 3(pi(pi)*) excited state is unlikely populated by the direct electronic excitation, while the low-lying singlet and triplet states, slightly higher in energy than the lowest triplet state, are easily accessible by the excitation light used in experiments. A series of radiationless transitions among related excited states yield the lowest 3(pi(pi)*) state, which has enough long lifetimes to exhibit its photochemical reactivities.

Journal Article↗
PubMed2006

A computational study of the lowest singlet and triplet states of neutral and dianionic 1,2-substituted icosahedral and octahedral o-carboranes.

This work introduces a calibrated B3LYP/6-31G(d) study on the electronic structure of singlet and triplet neutral species of 1,2-substituted icosahedral 1,2-R(2)-1,2-C(2)B(10)H(10) and octahedral 1,2-R(2)-1,2-C(2)B(4)H(4) molecules with R = {H, OH, SH, NH(2), PH(2), CH(3), SiH(3)} and their respective dianions formed by proton removal on each R group. A variety of small adiabatic singlet-triplet gaps DeltaE(ST) are obtained from these systems ranging from 2.93 eV (R = NH(2)) <or= DeltaE(ST) <or= 3.98 eV (R = SiH(3)) for the icosahedral neutrals and 1.56 eV (R = NH(2)) <or= DeltaE(ST) <or= 4.13 eV (R = SiH(3)) for the octahedral neutrals, these gaps being globally smaller for the dianionic systems, ranging from 0.94 eV (R(-) = CH(2) (-)) <or= DeltaE(ST) <or= 2.01 (R(-) = e(-)) for the icosahedral dianions 1,2-(R(-))(2)-C(2)B(10)H(10) and 0.91 (R(-) = CH(2) (-)) <or= DeltaE(ST) <or= 2.41 (R = SiH(2) (-)) for the octahedral dianions 1,2-(R(-))(2)--C(2)B(4)H(4) (R(-) = e(-), O(-), S(-), NH(-), PH(-), CH(2) (-), PH(2) (-)). The different gaps lie within or in the neighborhood of the visible region of the electromagetic spectrum. The optimized geometries for the molecular cage remain similar in substituted icosahedral and octahedral singlet states, while a rich variety of different structures can be found for the optimized triplet states.

Algorithms↗
PubMed1991

Production of identical twin and triplet mice by nuclear transplantation.

Transplantation of a single nucleus from two- or four-cell embryos into one of the enucleated blastomeres of a two-cell embryo resulted in successful production of identical triplet and twin mice. The proportion of reconstituted embryos that developed in blastocysts was 71% (84/118) when four-cell embryos were used as donors of nuclei; 10 sets of quadruplet and nine sets each of triplet and twin blastocysts were obtained by this technique. After transfer to recipients, 30% (18/61) developed to term, and one set of identical triplet and four sets of identical twin mice were obtained. When two-cell embryos were used as donors of nuclei, 79 (95%) sets of twin embryos developed to blastocysts. Of 38 twin blastocysts transferred to recipients, 21 sets (55%) developed to term as identical twin mice. These results demonstrate that the enucleated two-cell embryo develops in vitro after transfer of a nucleus from a two- or four-cell embryo and the resultant blastocyst has high potential for development to term after transfer to a recipient.

Animals↗
PubMed1985

Calcium-activated neutral protease in the peripheral nerve, which requires microM order Ca2+, and its effect on the neurofilament triplet.

There are two types of calcium-activated neutral protease (CANP), m-CANP and mu-CANP, following the nomenclature of Suzuki et al to show that each requires mM and microM Ca2+, respectively, for its activation. We found mu-CANP activity in a crude CANP fraction extracted from the peripheral nerve, which degraded the neurofilament (Nf) triplet (200 K, 160 K, 68 K), especially the 160 K component, at Ca2+ concentrations of 50 microM and 0.1 mM. The triplet was degraded in the order of the 160 K, 68 K, and 200 K components, respectively. In addition, the effects of partially purified mu-CANP of rabbit skeletal muscle, purified natural mu-CANP of bovine liver, derived mu-CANP prepared by autodigestion of chicken muscle m-CANP, m-CANP of chicken skeletal muscle, and cathepsin B of rat liver on the Nf were examined. Among the triplet components, the 160 K component was most rapidly degraded by all proteases so far tested. The difference in the effect of mu-CANP and m-CANP or cathepsin B on susceptibility of the 200 K component to degradation might be due to the difference of the relative amounts of enzymes to Nf.

Animals↗
PubMed2000

Identification and characterization of the miniature pig Huntington's disease gene homolog: evidence for conservation and polymorphism in the CAG triplet repeat.

Huntington's disease (HD) is associated with a significant expansion of a CAG trinucleotide repeat, which results in a lengthened polyglutamine tract in the single gene product, huntingtin, on human 4p16.3. We isolated cDNA clones that encompassed the entire coding sequence of the miniature pig HD gene (Sus HD) from two porcine testis cDNA libraries. The cDNA contig revealed a 12,749-nucleotide transcript coding for a 345-kDa protein (3139 amino acid residues), which exhibited 96% peptide sequence homology to human huntingtin. Northern blot analysis revealed that the Sus HD gene was ubiquitously expressed as two large transcripts of approximately 11 and 13 kb in size in all the tested tissues, much like the human HD gene. The CAG trinucleotide repeat was found to be interrupted by CAA triplets and to encode 17 or 18 consecutive glutamine residues. In our laboratory stock of miniature pig, three allotypes in the triplet repeat sequence were found. Thus, the Sus HD gene closely resembles its human counterpart in terms of sequence and expression pattern. In particular, human-miniature pig similarities in the normal length of the CAG triplet repeat as well as its repeat-number polymorphism may indicate that miniature pig would provide a good animal model for Huntington's disease.

3' Untranslated Regions↗
PubMed1995

Solution structure of a DNA quadruplex containing the fragile X syndrome triplet repeat.

Both X-ray and NMR structural studies have defined the polymorphic nature of G-quadruplexes generated through mutual stacking of G.G.G.G tetrads by guanine rich telomeric sequences. Recently, the fragile X syndrome d(C-G-G)n triplet nucleotide repeat has been shown to form a stable quadruplex of undefined structure in monovalent cation solution. We have undertaken a structural characterization of the d(G-C-G-G-T3-G-C-G-G) undecanucleotide to elucidate the structural alignments associated with quadruplex formation by this oligomer which contains sequence elements associated with the fragile X syndrome triplet repeat. d(G-C-G-G-T3-G-C-G-G) in Na+ cation solution forms a quadruplex through dimerization of two symmetry related hairpins with the lateral connecting T3 loops positioned at opposite ends of the quadruplex. This novel NMR-molecular dynamics based solution structure contains internal G.C.G.C tetrads sandwiched between terminal G.G.G.G tetrads. Watson-Crick G.C base-pairs within individual hairpins dimerize through their major groove edges using bifurcated hydrogen bonds to form internal G(anti).C(anti).G(anti).C(anti) tetrads. Adjacent strands are anti-parallel to each other around the symmetric G-quadruplex which contains two distinct narrow and two symmetric wide grooves. By contrast, the terminal G-tetrads adopt G(syn).G(anti).G(syn).G(anti) alignments. The structure of the d(G-C-G-G-T3-G-C-G-G) quadruplex with its multi-layer arrangement of G.G.G.G and G.C.G.C tetrads greatly expands on our current knowledge of quadruplex folding topologies. Our results establish the pairing alignments that can be potentially utilized by the fragile X syndrome triplet repeat to form quadruplex structures through dimerization of hairpin stems. The formation of novel G.C.G.C tetrads through dimerization of Watson-Crick G.C base-pairs is directly relevant to the potential pairing alignments of helical stems in genetic recombination.

DNA↗
PubMed1996

CTG triplet repeats from the myotonic dystrophy gene are expanded in Escherichia coli distal to the replication origin as a single large event.

The expansion and contraction of CTG and CGG trinucleotide repeat sequences have been associated with several heritable genetic diseases. We developed a system for investigating the expansion of triplet repeat sequences in Escherichia coli in order to elucidate molecular mechanisms. Analysis of expanded regions using the interrupting CTA triplet sequence as a location marker within the CTG tract revealed that the expansion of large CTG repeats is one event rather than an accumulation of multiple small expansions and that the expansions occur more frequently in the region distal from the replication origin. Also, we showed that a loss of interruptions increases the expansion frequency. Thus, the instability of large triplet repeats in hereditary diseases occurs by a mechanism different from the instability in microsatellite sequences caused by defects in mismatch repair systems for certain sporadic cancers and hereditary non-polyposis colorectal cancers.

Base Sequence↗
PubMed1995

Investigating the extension of pairwise distance pharmacophore measures to triplet-based descriptors.

Distances between key functional groups have been used for some time as molecular descriptors in 3D database screening and clustering calculations. More recently, a number of groups have explored triplets of molecular centers to describe key ligand features in terms of the properties of triangles. Three-body distances are attractive, since they retain more information than pairwise representations. In most applications, the triangular descriptors have been used to detail molecular shape, using all the constituent atoms or molecular surface points as descriptor centers. As a consequence, the database keying times were such that only single conformers could be considered during molecular descriptor calculations. In this paper we reduce the points used in the molecular description down to the key functional centers, as applied in 3D pharmacophore database searches. Molecular triplets can then be calculated which describe the relative dispositions of differing functional groups, made up from multiple molecular conformations of a given molecule. The new triplet descriptors are compared with classical pairwise distance measures using a variety of pharmacophores, and their potential in database screening, clustering and pharmacophore identification is discussed.

Databases, Factual↗
PubMed1977

Cytogenetics of triplet conjugation in Tetrahymena: origin of haploid and triploid clones.

Triplet conjugation occurs frequently when three different mating types of T. thermophila are mixed under appropriate conditions. Genetic studies show that fertilization is usually tripolar, with each conjugant contributing a pronucleus to one mate and receiving a pronucleus from the other. Triplets are less common and less stable when only two mating types are mixed, and nuclear exchange is not always reciprocal. Some conjugants contribute a pronucleus but do not receive one in return. Others receive two pronuclei instead of one. Such triplets characteristically yield one haploid, one diploid and one triploid exconjugant, all of which are able to establish vigorous clones.

Animals↗