Combined NGS Approaches Identify Mutations in the Intraflagellar Transport Gene IFT140 in Skeletal Ciliopathies with Early Progressive Kidney Disease

Ciliopathies are genetically heterogeneous disorders characterized by variable expressivity and overlaps between different disease entities. This is exemplified by the short rib‐polydactyly syndromes, Jeune, Sensenbrenner, and Mainzer‐Saldino chondrodysplasia syndromes. These three syndromes are frequently caused by mutations in intraflagellar transport (IFT) genes affecting the primary cilia, which play a crucial role in skeletal and chondral development. Here, we identified mutations in IFT140, an IFT complex A gene, in five Jeune asphyxiating thoracic dystrophy (JATD) and two Mainzer‐Saldino syndrome (MSS) families, by screening a cohort of 66 JATD/MSS patients using whole exome sequencing and targeted resequencing of a customized ciliopathy gene panel. We also found an enrichment of rare IFT140 alleles in JATD compared with nonciliopathy diseases, implying putative modifier effects for certain alleles. IFT140 patients presented with mild chest narrowing, but all had end‐stage renal failure under 13 years of age and retinal dystrophy when examined for ocular dysfunction. This is consistent with the severe cystic phenotype of Ift140 conditional knockout mice, and the higher level of Ift140 expression in kidney and retina compared with the skeleton at E15.5 in the mouse. IFT140 is therefore a major cause of cono‐renal syndromes (JATD and MSS). The present study strengthens the rationale for IFT140 screening in skeletal ciliopathy spectrum patients that have kidney disease and/or retinal dystrophy.     

Van der Waals heterostructures of SiC and Janus MSSe (M = Mo,W) monolayers: a first principles study

Favorable stacking patterns of two models with alternative orders of chalcogen atoms in SiC-MSSe (M = Mo, W) vdW heterostructures are investigated using density functional theory calculations. Both model-I and model-II of the SiC-MSSe (M = Mo, W) vdW heterostructures show type-II band alignment, while the spin orbit coupling effect causes considerable Rashba spin splitting. Furthermore, the plane-average electrostatic potential is also calculated to investigate the potential drops across the heterostructure and work function. The imaginary part of the dielectric function reveals that the first optical transition is dominated by excitons with high absorption in the visible region for both heterostructures. Appropriate band alignments with standard water redox potentials enable the capability of these heterostructures to dissociate water into H⁺/H₂ and O₂/H₂O.

Using DFT calculations, we have investigated the electronic structure, Rashba effect, optical and photocatalytic performance of SiC-MSSe (M = Mo, W) van der Waals heterostructures with different stacking patterns of chalcogen atoms.     

Improved identification and enrolment into care of HIV-exposed and -infected infants and children following a community health worker intervention in Lilongwe,Malawi

Background

Early identification and entry into care is critical to reducing morbidity and mortality in children with HIV. The objective of this report is to describe the impact of the Tingathe programme, which utilizes community health workers (CHWs) to improve identification and enrolment into care of HIV-exposed and -infected infants and children.

Methods

Three programme phases are described. During the first phase, Mentorship Only (MO) (March 2007–February 2008) on-site clinical mentorship on paediatric HIV care was provided. In the second phase, Tingathe-Basic (March 2008–February 2009), CHWs provided HIV testing and counselling to improve case finding of HIV-exposed and -infected children. In the final phase, Tingathe-PMTCT (prevention of mother-to-child transmission) (March 2009–February 2011), CHWs were also assigned to HIV-positive pregnant women to improve mother-infant retention in care. We reviewed routinely collected programme data from HIV testing registers, patient mastercards and clinic attendance registers from March 2005 to March 2011.

Results

During MO, 42 children (38 HIV-infected and 4 HIV-exposed) were active in care. During Tingathe-Basic, 238 HIV-infected children (HIC) were newly enrolled, a six-fold increase in rate of enrolment from 3.2 to 19.8 per month. The number of HIV-exposed infants (HEI) increased from 4 to 118. During Tingathe-PMTCT, 526 HIC were newly enrolled over 24 months, at a rate of 21.9 patients per month. There was also a seven-fold increase in the average number of exposed infants enrolled per month (9.5–70 patients per month), resulting in 1667 enrolled with a younger median age at enrolment (5.2 vs. 2.5 months; p<0.001).During the Tingathe-Basic and Tingathe-PMTCT periods, CHWs conducted 44,388 rapid HIV tests, 7658 (17.3%) in children aged 18 months to 15 years; 351 (4.6%) tested HIV-positive. Over this time, 1781 HEI were enrolled, with 102 (5.7%) found HIV-infected by positive PCR. Additional HIC entered care through various mechanisms (including positive linkage by CHWs and transfer-ins) such that by February 2011, a total of 866 HIC were receiving care, a 23-fold increase from 2008.

Conclusions

A multipronged approach utilizing CHWs to conduct HIV testing, link HIC into care and provide support to PMTCT mothers can dramatically improve the identification and enrolment into care of HIV-exposed and -infected children.     

Effect of Acute Ethanol on Uptake of [3H]Adenosine by Rat Cerebellar Synaptosomes

Many classes of CNS-acting drugs have been suggested to act at least partially via inhibition of adenosine uptake. Synaptosomal uptake of [3H]adenosine and the effect of acute ethanol on it were studied in a rat brain area known to be involved in the coordination and modulation of normal motor activity, the cerebellum. Uptake of [3H]adenosine was found to be linear with time (about 40 sec) and increasing concentrations (up to 1.5 microM) of adenosine. The uptake of [3H]adenosine was inhibited by dilazep (IC50 = 2.5 x 10(-7) M) in a dose-dependent manner. Pharmacologically and/or toxicologically relevant concentrations of ethanol (2.5 to 100 mM) significantly inhibited the uptake of [3H]adenosine between 12 and 15%. Lineweaver-Burk plots indicated that both in vitro (25 mM) and in vivo (1.5 g/kg i.p.; 30 mM blood level) ethanol lowered Km as well as Vmax values for adenosine uptake to nearly the same extent. In the case of in vivo ethanol, no ethanol was present during the assay since synaptosome preparation would wash out residual ethanol. The results of the present study indicate possible membranal alterations by in vivo ethanol. It is concluded that the uptake of [3H]adenosine is inhibited by intoxicating concentrations of ethanol in vitro and by acute ethanol (1.5 g/kg) in vivo. This may partially explain the modulatory role of endogenous adenosine in ethanol-induced motor disturbances.