Quantifying the ossification of the carpus in skeletal age estimation: Radiographic standards for Australian subadults.

An evaluation of the development of a child's skeleton and estimation of bone age provides an insight into a child's overall maturation. This study aimed to introduce a contemporary method for assessing bone age of Australian children using formulae incorporating carpal areal measurements. The standards introduced in this study can be used to assess the developmental status of Australian children who may be affected by growth-related illnesses. Additionally, in situations where the living age of a subadult is unknown, methodologies to accurately estimate age are required, particularly in the Western world where knowledge of the age of an individual is necessary for legal reasons. The sample consisted of retrospective hand and wrist radiographs acquired from 541 children (females: 246, males: 295) aged from birth to 20 years. Using the DICOM viewer Weasis, the carpal area ratio (B.Ar/T.Ar) was calculated for each individual radiograph by measuring the carpal bone area (B.Ar) and total tissue area of the carpus (T.Ar). A changepoint regression model demonstrated that the model constructed in this study was the most accurate in the younger age groups and was able to accurately determine whether a child was under 12 years if female and 13 years if male. A rapid acceleration of growth was observed at approximately 12-13 years in our sample, which may represent the onset of the pubertal growth spurt; this resulted in a high data variance and low model prediction accuracy in female and male children older than 12 and 13 years, respectively.

The effect of breastmilk and saliva combinations on the in vitro growth of oral pathogenic and commensal microorganisms.

Neonates are exposed to microbes in utero and at birth, thereby establishing their microbiota (healthy microbial colonisers). Previously, we reported significant differences in the neonatal oral microbiota of breast-fed and formula-fed babies after first discovering a primal metabolic mechanism that occurs when breastmilk (containing the enzyme xanthine oxidase) and neonatal saliva (containing highly elevated concentrations of the substrates for xanthine oxidase: xanthine and hypoxanthine). The interaction of neonatal saliva and breast milk releases antibacterial compounds including hydrogen peroxide, and regulates the growth of bacteria. Using a novel in vitro experimental approach, the current study compared the effects of this unique metabolic pathway on a range of bacterial species and determined the period of time that microbial growth was affected. We demonstrated that microbial growth was inhibited predominately, immediately and for up to 24 hr following breastmilk and saliva mixing; however, some microorganisms were able to recover and continue to grow following exposure to these micromolar amounts of hydrogen peroxide. Interestingly, growth inhibition was independent of whether the organisms possessed a catalase enzyme. This study further confirms that this is one mechanism that contributes to the significant differences in the neonatal oral microbiota of breast-fed and formula-fed babies.

Deep sequencing of the 16S ribosomal RNA of the neonatal oral microbiome: a comparison of breast-fed and formula-fed infants.

In utero and upon delivery, neonates are exposed to a wide array of microorganisms from various sources, including maternal bacteria. Prior studies have proposed that the mode of feeding shapes the gut microbiota and, subsequently the child's health. However, the effect of the mode of feeding and its influence on the development of the neonatal oral microbiota in early infancy has not yet been reported. The aim of this study was to compare the oral microbiota of healthy infants that were exclusively breast-fed or formula-fed using 16S-rRNA gene sequencing. We demonstrated that the oral bacterial communities were dominated by the phylum Firmicutes, in both groups. There was a higher prevalence of the phylum Bacteroidetes in the mouths of formula-fed infants than in breast-fed infants (p = 0.01), but in contrast Actinobacteria were more prevalent in breast-fed babies; Proteobacteria was more prevalent in saliva of breast-fed babies than in formula-fed neonates (p = 0.04). We also found evidence suggesting that the oral microbiota composition changed over time, particularly Streptococcus species, which had an increasing trend between 4-8 weeks in both groups. This study findings confirmed that the mode of feeding influences the development of oral microbiota, and this may have implications for long-term human health.

Antenatal ureaplasma infection impairs development of the fetal ovine gut in an IL-1-dependent manner.

Ureaplasma infection of the amniotic cavity is associated with adverse postnatal intestinal outcomes. We tested whether interleukin-1 (IL-1) signaling underlies intestinal pathology following ureaplasma exposure in fetal sheep. Pregnant ewes received intra-amniotic injections of ureaplasma or culture media for controls at 3, 7, and 14 d before preterm delivery at 124 d gestation (term 150 d). Intra-amniotic injections of recombinant human interleukin IL-1 receptor antagonist (rhIL-1ra) or saline for controls were given 3 h before and every 2 d after Ureaplasma injection. Ureaplasma exposure caused fetal gut inflammation within 7 d with damaged villus epithelium and gut barrier loss. Proliferation, differentiation, and maturation of enterocytes were significantly reduced after 7 d of ureaplasma exposure, leading to severe villus atrophy at 14 d. Inflammation, impaired development and villus atrophy of the fetal gut was largely prevented by intra-uterine rhIL-1ra treatment. These data form the basis for a clinical understanding of the role of ureaplasma in postnatal intestinal pathologies.

Video analysis of falls experienced by paediatric iceskaters and roller/inline skaters.

OBJECTIVES: To evaluate differences in the way iceskaters and roller/inline skaters fall. METHODS: Children's falls related to skating were videotaped and categorised based on type of skating activity, child's estimated age, direction of fall, whether the child attempted to break the fall, and whether the head struck the skating surface. RESULTS: In total, 216 iceskating and 201 roller/inline skating falls were captured on videotape. In both iceskating and roller/inline skating, the majority of falls were forward in direction. The skaters attempted to break the falls with their arms or hands in over 90% of falls in both iceskating (93.1%) and roller/inline skating (94.5%). A greater proportion of falls in iceskating resulted in the head striking the skating surface (13.0%) than did those in roller/inline skating (3.0%) (odds ratio = 4.8; 95% confidence interval 1.9 to 13.3; p<0.001). CONCLUSIONS: This study found that paediatric iceskaters and roller/inline skaters fall similarly and that both types of skaters try to break their falls with their arms or hands; however, because iceskating takes place on a low friction surface, attempts to break falls with the arms or hands are often unsuccessful, leading to head and face injuries. The development of a new type of protective gear, a wrist guard with a non-slip palm, should stop iceskaters from striking the head, protect against upper extremity fractures, and unlike a bulky helmet, should not discourage children from skating.

The phylogeny of Ureaplasma urealyticum based on the mba gene fragment.

Sequencing of mba gene fragments of reference strains of Ureaplasma urealyticum serovars 1, 3, 6, 14 and 8, in addition to 33 clinical U. urealyticum isolates is reported. A phylogenetic tree deduced from alignment of these sequences clearly demonstrates two major clusters (confidence limit 100%), which equate to the parvo and T960 biovars, and five types, which have been designated mba 1, 3, 6, 8 and X. These relationships are supported by bootstrap analysis. Polymorphisms within the mba fragment of types mba 1, 3 and 6 were used to define nine subtypes (mba 1a, 1b, 3a, 3b, 3c, 3d, 3e, 6a and 6b), thus facilitating high resolution typing of U. urealyticum. Inclusion of reference strains for serovars 1, 3, 6 and 8 in the mba typing scheme showed that the results of this analysis are broadly consistent with currently accepted serotyping. In addition, a ure gene fragment from nine of the clinical isolates was amplified and sequenced. Comparisons of the sequences clearly distinguished the two biovars of U. urealyticum; however, this fragment was invariant within the parvo biovar. This study has shown that the mba sequence can reveal the fine details of the relationships between U. urealyticum isolates and also supports the significant evolutionary gap between the two biovars.

Comparison of PCR, nested PCR, and random amplified polymorphic DNA PCR for detection and typing of Ureaplasma urealyticum in specimens from pregnant women.

A PCR assay, using three primer pairs, was developed for the detection of Ureaplasma urealyticum, parvo biovar, mba types 1, 3, and 6, in cultured clinical specimens. The primer pairs were designed by using the polymorphic base positions within a 310- to 311-bp fragment of the 5' end and upstream control region of the mba gene. The specificity of the assay was confirmed with reference serovars 1, 3, 6, and 14 and by the amplified-fragment sizes (81 bp for mba 1, 262 bp for mba 3, and 193 bp for mba 6). A more sensitive nested PCR was also developed. This involved a first-step PCR, using the primers UMS-125 and UMA226, followed by the nested mba-type PCR described above. This nested PCR enabled the detection and typing of small numbers of U. urealyticum cells, including mixtures, directly in original clinical specimens. By using random amplified polymorphic DNA (RAPD) PCR with seven arbitrary primers, we were also able to differentiate the two biovars of U. urealyticum and to identify 13 RAPD-PCR subtypes. By applying these subtyping techniques to clinical samples collected from pregnant women, we established that (i) U. urealyticum is often a persistent colonizer of the lower genital tract from early midtrimester until the third trimester of pregnancy, (ii) mba type 6 was isolated significantly more often (P = 0.048) from women who delivered preterm than from women who delivered at term, (iii) no particular ureaplasma subtype(s) was associated with placental infections and/or adverse pregnancy outcomes, and (iv) the ureaplasma subtypes most frequently isolated from women were the same subtypes most often isolated from infected placentas.

The role of Ureaplasma urealyticum in adverse pregnancy outcome.

We investigated Ureaplasma urealyticum genital tract colonization rates in an Australian population to determine whether colonization was associated with adverse pregnancy outcome. Women attending an antenatal clinic were evaluated for lower genital tract colonization at their first antenatal visit (162 women) and at 28 weeks' gestation (120 women). Placentas from 92 women were cultured. U. urealyticum was the predominant isolate from the lower (57.4%) and upper (17.4%) genital tract in this population of pregnant women. U. urealyticum was a persistent colonizer during mid-trimester of pregnancy (in 88% of women colonized) whereas M. hominis, G. vaginalis, and Group B streptococcus were present as transient flora of the lower genital tract. Lower genital tract colonization during pregnancy was not directly associated with adverse pregnancy outcome. However preterm delivery in afebrile, asymptomatic women, could possibly be associated with chorioamnionitis (4 of 16 preterm births). Screening of women with a history of preterm birth may prevent upper genital tract infections and preterm delivery.