Genetic aspects of dental disorders

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.This paper reviews past and present applications of quantitative and molecular genetics to dental disorders. Examples are given relating to craniofacial development (including malocclusion), oral supporting tissues (including periodontal diseases) and dental hard tissues (including defects of enamel and dentine as well as dental caries). Future developments and applications to clinical dentistry are discussed. Early investigations confirmed genetic bases to dental caries, periodontal diseases and malocclusion, but research findings have had little impact on clinical practice. The complex multifactorial aetiologies of these conditions, together with methodological problems, have limited progress until recently. Present studies are clarifying previously unrecognized genetic and phenotypic heterogeneities and attempting to unravel the complex interactions between genes and environment by applying new statistical modelling approaches to twin and family data. linkage studies using highly polymorphic DNA markers are providing a means of locating candidate genes, including quantitative trait loci (QTL). In future, as knowledge increases: it should be possible to implement preventive strategies for those genetically-predisposed individuals who are identified-predisposed individuals who are identified to be at risk.Grant C. Townsend, Michael J. Aldred and P. Mark Bartol

Phylogeny and evolution of life-history strategies in the Sycophaginae non-pollinating fig wasps (Hymenoptera, Chalcidoidea)

<p>Abstract</p> <p>Background</p> <p>Non-pollinating Sycophaginae (Hymenoptera, Chalcidoidea) form small communities within <it>Urostigma </it>and <it>Sycomorus </it>fig trees. The species show differences in galling habits and exhibit apterous, winged or dimorphic males. The large gall inducers oviposit early in syconium development and lay few eggs; the small gall inducers lay more eggs soon after pollination; the ostiolar gall-inducers enter the syconium to oviposit and the cleptoparasites oviposit in galls induced by other fig wasps. The systematics of the group remains unclear and only one phylogeny based on limited sampling has been published to date. Here we present an expanded phylogeny for sycophagine fig wasps including about 1.5 times the number of described species. We sequenced mitochondrial and nuclear markers (4.2 kb) on 73 species and 145 individuals and conducted maximum likelihood and Bayesian phylogenetic analyses. We then used this phylogeny to reconstruct the evolution of Sycophaginae life-history strategies and test if the presence of winged males and small brood size may be correlated.</p> <p>Results</p> <p>The resulting trees are well resolved and strongly supported. With the exception of <it>Apocrytophagus</it>, which is paraphyletic with respect to <it>Sycophaga</it>, all genera are monophyletic. The Sycophaginae are divided into three clades: (i) <it>Eukoebelea</it>; (ii) <it>Pseudidarnes</it>, <it>Anidarnes </it>and <it>Conidarnes </it>and (iii) <it>Apocryptophagus</it>, <it>Sycophaga </it>and <it>Idarnes</it>. The ancestral states for galling habits and male morphology remain ambiguous and our reconstructions show that the two traits are evolutionary labile.</p> <p>Conclusions</p> <p>The three main clades could be considered as tribes and we list some morphological characters that define them. The same biologies re-evolved several times independently, which make Sycophaginae an interesting model to test predictions on what factors will canalize the evolution of a particular biology. The ostiolar gall-inducers are the only monophyletic group. In 15 Myr, they evolved several morphological adaptations to enter the syconia that make them strongly divergent from their sister taxa. Sycophaginae appears to be another example where sexual selection on male mating opportunities favored winged males in species with small broods and wingless males in species with large broods. However, some species are exceptional in that they lay few eggs but exhibit apterous males, which we hypothesize could be due to other selective pressures selecting against the re-appearance of winged morphs.</p

Inflammation in early kidney allograft surveillance biopsies and its relationship with de novo donor specific antibodies

Interstitial fibrosis and tubular atrophy (IFTA) associated with interstitial inflammation in non scarred areas (IFTA+i) is associated with poorer graft outcome than inflammation without IFTA or IFTA without inflammation. We evaluated if histological categories at week 6 could predict the development of interstitial fibrosis and de novo donor specific anti-HLA antibodies (dnDSA) at one year. Biopsies were classified according to Banff criteria as normal (i+t≤1 and ci+ct≤1), inflammation (i+t≥2 and ci+ct≤1), IFTA (i+t≤1 and ci+ct≥2) or IFTA+i (i+t≥2 and ci+ct≥2). We analyzed 598 standard immunological risk recipients. The histological diagnosis at 6 weeks was: normal (n= 206), inflammation (n=29), IFTA (n=255) and IFTA+i (n=108). Moderate/severe interstitial fibrosis (ci≥2) at 1 year was observed in 4.2% of patients with prior (6 weeks) normal histology, in 3.4% with inflammation, in 13.8 % with IFTA and in 24.5% with IFTA+i (p=0.0001). Fifty-three recipients (8.9%) had dnDSA at 1 year. Independent predictors of development of dnDSA at 1 year were: HLA-DR mismatches (OR 1.95, 95%CI 1.09-3.49), the presence of inflammation (OR 5.49, 95% CI 1.67-18.03) or IFTA+i (OR 4.09, 95%CI 1.67-10.0) in the 6 week surveillance biopsy. This research has been accepted and published in Transplantation. © 2017 Lippincott, Williams & Wilkin

Early Surfactant Guided by Lamellar Body Counts on Gastric Aspirate in Very Preterm Infants

Background: We have developed a rapid method, based on lamellar body counts (LBC) on gastric aspirate, for identifying newborns who will develop respiratory distress syndrome with a need for surfactant supplementation. Objective: We set out to test whether it was possible to improve the outcome when used in a clinical trial. Methods: We randomly assigned 380 infants born at 24-29 weeks' gestation and supported with nasal continuous positive airway pressure (nCPAP) to receive surfactant guided either by LBC (intervention group) or increasing need for oxygen (control group). The primary outcome was mechanical ventilation or death within 5 days. Secondary outcomes included need for oxygen expressed by arterial to alveolar oxygen tension ratio (a/APO(2)) at the age of 6 h and need for oxygen at day 28. Results: The primary outcomes were equal (25%) in the two groups. The intervention group had higher a/APO(2) than the control group at 6 h, median 0.64 versus 0.52 (p < 0.01), and the subgroup with gestational age 26-29 weeks needed fewer days of oxygen supplementation than the controls, median 2 vs. 9 days (p = 0.01), and fewer infants needed oxygen at day 28 (p = 0.04). Furthermore, there was a tendency in the intervention group towards a shorter duration of nCPAP. Too little or viscose aspirate in 23% of the cases was a limitation of the method. Conclusion: Using LBC test as indicator of lung maturity and early surfactant therapy in very preterm newborns, it is possible to reduce the need for oxygen supplementation. Copyright (C) 2013 S. Karger AG, Base