Termite sensitivity to temperature affects global wood decay rates.

Deadwood is a large global carbon store with its store size partially determined by biotic decay. Microbial wood decay rates are known to respond to changing temperature and precipitation. Termites are also important decomposers in the tropics but are less well studied. An understanding of their climate sensitivities is needed to estimate climate change effects on wood carbon pools. Using data from 133 sites spanning six continents, we found that termite wood discovery and consumption were highly sensitive to temperature (with decay increasing >6.8 times per 10°C increase in temperature)-even more so than microbes. Termite decay effects were greatest in tropical seasonal forests, tropical savannas, and subtropical deserts. With tropicalization (i.e., warming shifts to tropical climates), termite wood decay will likely increase as termites access more of Earth's surface.

Identifying the Biosynthetic Gene Cluster for Triacsins with an N-Hydroxytriazene Moiety.

Triacsins are a family of natural products having in common an N-hydroxytriazene moiety not found in any other known secondary metabolites. Though many studies have examined the biological activity of triacsins in lipid metabolism, their biosynthesis has remained unknown. Here we report the identification of the triacsin biosynthetic gene cluster in Streptomyces aureofaciens ATCC 31442. Bioinformatic analysis of the gene cluster led to the discovery of the tacrolimus producer Streptomyces tsukubaensis NRRL 18488 as a new triacsin producer. In addition to targeted gene disruption to identify necessary genes for triacsin production, stable isotope feeding was performed in vivo to advance the understanding of N-hydroxytriazene biosynthesis.

Application of risk score analysis to low-coverage whole genome sequencing data for the noninvasive detection of trisomy 21, trisomy 18, and trisomy 13.

OBJECTIVES: Clinical performance of a low coverage, low cost, massively parallel sequencing (MPS)-based assay to stratify risk of trisomy 21, 18, and 13 pregnancies was determined. METHODS: The study included 1100 samples with birth outcome or karyotype results, comprising low-risk patients (84.2%) negative for risk indications from maternal age, serum screening, ultrasound, or family history, and high-risk patients (15.8%) with at least one of the aforementioned indications. Cell free DNA (cfDNA) was extracted from maternal plasma. Library preparation incorporated 96 index barcodes to enable sequencing on a HiSeq 2000 or 2500. Risk scores were calculated using chromosomal representation, fetal fraction, and maternal age at the estimated date of delivery. A risk score greater than or equal to 1 in 100 was used to stratify samples as high risk for trisomy 21, trisomy 18, or trisomy 13. RESULTS: Sensitivity and specificity were calculated based on risk group stratification. Trisomy 21, trisomy 18, and trisomy 13 were detected with greater than 99% sensitivity and 99.9% specificity. Fetal sex classification accuracy was 99.3%. CONCLUSIONS: We conclude that simplified MPS can be used to stratify the risk of pregnancies for trisomy 21, trisomy 18, and trisomy 13 and accurately determine fetal sex. © 2015 John Wiley & Sons, Ltd.

Clinical and neuroimaging findings of Cree leukodystrophy: a retrospective case series.

BACKGROUND AND PURPOSE: CLD is a rapidly progressive and invariably fatal neurodegenerative disorder. We describe clinical and neuroimaging findings in 5 infants with CLD. MATERIALS AND METHODS: Retrospective review of medical records of infants with CLD from the past 11 years at our institution was performed. Relevant clinical and demographic data were recorded. Specific attention was directed toward postmortem examination findings and genetic testing. CT and MR imaging results were reviewed. RESULTS: Five Cree infants were diagnosed with CLD. CT demonstrated bilateral symmetric hypoattenuation of the white matter and globus pallidus. MR imaging demonstrated corresponding T2 hyperintensity in these regions and abnormal signal intensity in the thalami and substantia nigra. Symmetric restricted diffusion in the deep white matter was seen. MRS demonstrated decreased NAA, elevated choline, and the presence of lactate. Postmortem examination in 1 infant showed corresponding poor myelination in the brain stem, cerebellum, deep gray structures, and the cerebral hemispheres. Genetic testing in 2 infants revealed homozygous mutations in the eIF2B5 gene. CONCLUSIONS: Neuroimaging in CLD is striking and is an important tool in diagnosing CLD. Extensive white matter involvement as well as involvement of the globus pallidus and patchy involvement of the thalami and substantia nigra are characteristic. MRS findings are compatible with destruction of normal brain parenchyma with evidence of anaerobic metabolism in the regions of demyelination. Clinical suspicion of VWM in a Native American infant from this region should prompt the consideration of CLD with appropriate imaging work-up and genetic testing.

Synthesis of a highly substituted N(6)-linked immobilized NAD(+) derivative using a rapid solid-phase modular approach: suitability for use with the kinetic locking-on tactic for bioaffinity purification of NAD(+)-dependent dehydrogenases.

This study is concerned with further development of the kinetic locking-on strategy for bioaffinity purification of NAD(+)-dependent dehydrogenases. Specifically, the synthesis of highly substituted N(6)-linked immobilized NAD(+) derivatives is described using a rapid solid-phase modular approach. Other modifications of the N(6)-linked immobilized NAD(+) derivative include substitution of the hydrophobic diaminohexane spacer arm with polar spacer arms (9 and 19.5 A) in an attempt to minimize nonbiospecific interactions. Analysis of the N(6)-linked NAD(+) derivatives confirm (i) retention of cofactor activity upon immobilization (up to 97%); (ii) high total substitution levels and high percentage accessibility levels when compared to S(6)-linked immobilized NAD(+) derivatives (also synthesized with polar spacer arms); (iii) short production times when compared to the preassembly approach to synthesis. Model locking-on bioaffinity chromatographic studies were carried out with bovine heart l-lactate dehydrogenase (l-LDH, EC 1.1.1.27), bakers yeast alcohol dehydrogenase (YADH, EC 1.1.1.1) and Sporosarcinia sp. l-phenylalanine dehydrogenase (l-PheDH, EC 1.4.1.20), using oxalate, hydroxylamine, and d-phenylalanine, respectively, as locking-on ligands. Surprisingly, two of these test NAD(+)-dependent dehydrogenases (lactate and alcohol dehydrogenase) were found to have a greater affinity for the more lowly substituted S(6)-linked immobilized cofactor derivatives than for the new N(6)-linked derivatives. In contrast, the NAD(+)-dependent phenylalanine dehydrogenase showed no affinity for the S(6)-linked immobilized NAD(+) derivative, but was locked-on strongly to the N(6)-linked immobilized derivative. That this locking-on is biospecific is confirmed by the observation that the enzyme failed to lock-on to an analogous N(6)-linked immobilized NADP(+) derivative in the presence of d-phenylalanine. This differential locking-on of NAD(+)-dependent dehydrogenases to N(6)-linked and S(6)-linked immobilized NAD(+) derivatives cannot be explained in terms of final accessible substitutions levels, but suggests fundamental differences in affinity of the three test enzymes for NAD(+) immobilized via N(6)-linkage as compared to thiol-linkage.

Rotational coupling of the transmembrane and kinase domains of the Neu receptor tyrosine kinase.

Ligand binding to receptor tyrosine kinases (RTKs) regulates receptor dimerization and activation of the kinase domain. To examine the role of the transmembrane domain in regulation of RTK activation, we have exploited a simplified transmembrane motif, [VVVEVVV](n), previously shown to activate the Neu receptor. Here we demonstrate rotational linkage of the transmembrane domain with the kinase domain, as evidenced by a periodic activation of Neu as the dimerization motif is shifted across the transmembrane domain. These results indicate that activation requires a specific orientation of the kinase domains with respect to each other. Results obtained with platelet-derived growth factor receptor-beta suggest that this rotational linkage of the transmembrane domain to the kinase domain may be a general feature of RTKs. These observations suggest that activating mutations in RTK transmembrane and juxtamembrane domains will be limited to those residues that position the kinase domains in an allowed rotational conformation.

Transformation and Stat activation by derivatives of FGFR1, FGFR3, and FGFR4.

The fibroblast growth factor receptor (FGFR) family members mediate a number of important cellular processes, and are mutated or overexpressed in several forms of human cancer. Mutation of Lys650-->Glu in the activation loop of the FGFR3 kinase domain causes the lethal human skeletal disorder thanatophoric dysplasia type II (TDII) and is also found in patients with multiple myeloma, bladder and cervical carcinomas. This mutation leads to constitutive activation of FGFR3. To compare the signaling activity of FGFR family members, this activating mutation was generated in FGFR1, FGFR3, and FGFR4. We show that the kinase domains of FGFR1, FGFR3, and FGFR4 containing the activation loop mutation, when targeted to the plasma membrane by a myristylation signal, can transform NIH3T3 cells and induce neurite outgrowth in PC12 cells. Phosphorylation of Shp2, PLC-gamma, and MAPK was also stimulated by all three 'TDII-like' FGFR derivatives. Additionally, activation of Stat1 and Stat3 was observed in cells expressing the activated FGFR derivatives. Finally, we demonstrate that FGFR1, FGFR3, and FGFR4 derivatives can stimulate PI-3 kinase activity. Our comparison of these activated receptor derivatives reveals a significant overlap in the panel of effector proteins used to mediate downstream signals. This also represents the first demonstration that activation of FGFR4, in addition to FGFR1 and FGFR3, can induce cellular transformation. Moreover, our results suggest that Stat activation by FGFRs is important in their ability to act as oncogenes.

RTK mutations and human syndromeswhen good receptors turn bad.

Mutations in receptor tyrosine kinases (RTKs) have been linked to an increasing number of inherited human disease syndromes, including dwarfism, craniosynostosis, heritable cancer susceptibility, venous malformation and Piebaldism. Both gain-of-function mutations resulting in constitutive receptor activation, and loss-of-function mutations resulting in non-functional or dominant negative receptors, have been observed. This review summarizes RTK families that are involved in inherited syndromes, describes the molecular consequences of the disease mutations, and predicts that many novel mutations remain to be identified.

Periodontal status in a Hutterite population.

The periodontal status of a population of 117 adult Hutterites living in Saskatchewan, Canada, was assessed. Despite poor oral hygiene levels, and inadequate dental knowledge, the presence of periodontitis was low. The findings are in accordance with data obtained recently from other selected populations.

Pseudomonas aeruginosa in the oral cavity and sputum of patients with cystic fibrosis.

Patients with cystic fibrosis (CF) are often hosts to colonies of both mucoid and nonmucoid strains of Pseudomonas aeruginosa. The major pathogens for chronic and recurrent pulmonary infection in these patients are the mucoid variants of P. aeruginosa. Of the 31 CF patients studied, 14 patients yielded both mucoid and nonmucoid strains of P. aeruginosa from the various oral ecologic sites and saliva. Of the sites tested, the dorsum of the tongue gave the highest yield of P. aeruginosa (27 strains), followed by the buccal mucosa (17 strains), saliva (15 strains), and dental plaques (6 strains). Eleven patients had P. aeruginosa in the oral cavity and sputum simultaneously. Antibiotic susceptibility tests on these multiple isolates suggest that CF patients may be cocolonized or coinfected by two or more strains of P. aeruginosa. Therefore, it may be important to identify multiple isolates of P. aeruginosa, not only from sputum cultures but also from oral cultures, for antibiotic-susceptibility testing. Oral colonization by the mucoid variants of P. aeruginosa may lead to further colonization in the lower respiratory tract and subsequent pulmonary infection in CF patients.