Quantitative Analysis of Nucleic Acid Hybridization on Magnetic Particles and Quantum Dot-Based Probes

In the present study we describe sandwich design hybridization probes consisting of magnetic particles (MP) and quantum dots (QD) with target DNA, and their application in the detection of avian influenza virus (H5N1) sequences. Hybridization of 25-, 40-, and 100-mer target DNA with both probes was analyzed and quantified by flow cytometry and fluorescence microscopy on the scale of single particles. The following steps were used in the assay: (i) target selection by MP probes and (ii) target detection by QD probes. Hybridization efficiency between MP conjugated probes and target DNA hybrids was controlled by a fluorescent dye specific for nucleic acids. Fluorescence was detected by flow cytometry to distinguish differences in oligo sequences as short as 25-mer capturing in target DNA and by gel-electrophoresis in the case of QD probes. This report shows that effective manipulation and control of micro- and nanoparticles in hybridization assays is possible

Neuropsychiatric symptoms in 921 elderly subjects with dementia: a comparison between vascular and neurodegenerative types.

Objective:  i) to describe the neuropsychiatric profile of elderly subjects with dementia by comparing vascular (VaD) and degenerative dementias, i.e. dementia with Lewy bodies (DLB) and Alzheimer’s disease (AD); ii) to assess whether the severity and type of dementia are associated with clinically relevant neuropsychiatric symptoms (CR‐NPS). Method:  One hundred and thirty‐one out‐patients with VaD, 100 with DLB and 690 with AD were studied. NPS were evaluated by the neuropsychiatric inventory (NPI). Results:  Vascular dementia had lower total and domain‐specific NPI scores and a lower frequency of CR‐NPS than AD and DLB, for which frequency of CR‐NPS increased significantly with disease severity, particularly in AD. Logistic regression analysis showed that a higher CDR score and a diagnosis of degenerative dementia were independently associated with CR‐NPS. Conclusion:  Vascular dementia is associated less with CR‐NPS than AD and DLB. Frequency of CR‐NPS increases with disease severity in AD and, to a lesser extent, in DLB

Impact of facial conformation on canine health: Brachycephalic Obstructive Airway Syndrome

The domestic dog may be the most morphologically diverse terrestrial mammalian species known to man; pedigree dogs are artificially selected for extreme aesthetics dictated by formal Breed Standards, and breed-related disorders linked to conformation are ubiquitous and diverse. Brachycephaly–foreshortening of the facial skeleton–is a discrete mutation that has been selected for in many popular dog breeds e.g. the Bulldog, Pug, and French Bulldog. A chronic, debilitating respiratory syndrome, whereby soft tissue blocks the airways, predominantly affects dogs with this conformation, and thus is labelled Brachycephalic Obstructive Airway Syndrome (BOAS). Despite the name of the syndrome, scientific evidence quantitatively linking brachycephaly with BOAS is lacking, but it could aid efforts to select for healthier conformations. Here we show, in (1) an exploratory study of 700 dogs of diverse breeds and conformations, and (2) a confirmatory study of 154 brachycephalic dogs, that BOAS risk increases sharply in a non-linear manner as relative muzzle length shortens. BOAS only occurred in dogs whose muzzles comprised less than half their cranial lengths. Thicker neck girths also increased BOAS risk in both populations: a risk factor for human sleep apnoea and not previously realised in dogs; and obesity was found to further increase BOAS risk. This study provides evidence that breeding for brachycephaly leads to an increased risk of BOAS in dogs, with risk increasing as the morphology becomes more exaggerated. As such, dog breeders and buyers should be aware of this risk when selecting dogs, and breeding organisations should actively discourage exaggeration of this high-risk conformation in breed standards and the show ring

Epigenetic alterations in metastatic cutaneous carcinoma

BackgroundSquamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are the 2 most common cutaneous carcinomas. Molecular profiles predicting metastasis of these cancers have not been identified.MethodsEpigenetic profiles of 37 primary cases of cutaneous SCC and BCC were quantified via the Illumina Goldengate Cancer Panel. Differential protein expression by metastatic potential was analyzed in 110 total cases by immunohistochemical (IHC) staining.ResultsUnsupervised hierarchical clustering analysis revealed that metastatic BCCs had a methylation profile resembling cutaneous SCCs. Metastatic cutaneous SCCs were found to be hypermethylated at FRZB (median methylation: 46.7% vs 4.7%; p = 4 × 10−5). Metastatic BCCs were found to be hypomethylated at MYCL2 (median methylation: 3.8% vs 83.4%; p = 1.9 × 10−6). Immunohistochemical staining revealed few differences between metastatic and nonmetastatic cancers.ConclusionMetastatic primary BCCs and cutaneous SCCs had distinct epigenetic profiles when compared to their nonmetastatic counterparts. Epigenetic profiling may prove useful in future diagnosis and prevention of advanced nonmelanoma skin cancers. © 2014 Wiley Periodicals, Inc. Head Neck 37: 994–1001, 2015Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111931/1/hed23701.pd

Nucleotide sequence encoding the carboxyl-terminal half of apolipoprotein B from spontaneously hypercholesterolemic pigs.

Previous studies from this laboratory characterized the hypercholesterolemia of pigs with a mutant allele of apolipoprotein B (apoB), designated Lpb5. This apoB allele is associated with low density lipoprotein (LDL) particles deficient in binding to the LDL receptor. To identify potential causative mutations in Lpb5 DNA, 10.6 kb of genomic DNA, encoding the carboxyl-terminal 58% of apoB were sequenced from the Lpb5 allele and from an allele encoding phenotypically normal apoB. Comparison of the two DNA sequences revealed 33 polymorphisms, 13 of which resulted in amino acid polymorphisms. To determine whether any of the amino acids at the polymorphic positions in Lpb5-encoded apoB were unique to that isoform, those positions were sequenced in four other pig apoB alleles encoding phenotypically normal apoB. None of the amino acids were by themselves uniquely encoded by the Lpb5 allele. However, a unique haplotype consisting of Asp3164 in conjunction with Ala3447 distinguished the Lpb5-encoded apoB from all other allelic isoforms sequenced in this region. To gain insight into changes in the tertiary structure of the mutant apoB, 13C-NMR analysis of LDL reductively methylated with [13C]-formaldehyde was performed. LDL has lysine residues that titrate at pH 10.5 and others that titrate at pH 8.9. The latter residues are thought to include those involved in the interaction of LDL with the LDL receptor. LDL from Lpb5 pigs possessed a smaller proportion of lysine residues titrating at pH 8.9 than did LDL from non-Lpb5 pigs, suggesting that the Lpb5-encoded apoB is altered in a manner affecting the microenvironment of particular lysine residues

Antioxidants inhibit low density lipoprotein oxidation less at lysosomal pH: a possible explanation as to why the clinical trials of antioxidants might have failed

Oxidised low density lipoprotein (LDL) was considered to be important in the pathogenesis of atherosclerosis, but the large clinical trials of antioxidants, including the first one using probucol (the PQRST Trial), failed to show benefit and have cast doubt on the importance of oxidised LDL. We have shown previously that LDL oxidation can be catalysed by iron in the lysosomes of macrophages. The aim of this study was therefore to investigate the effectiveness of antioxidants in preventing LDL oxidation at lysosomal pH and also establish the possible mechanism of oxidation. Probucol did not effectively inhibit the oxidation of LDL at lysosomal pH, as measured by conjugated dienes or oxidised cholesteryl esters or tryptophan residues in isolated LDL or by ceroid formation in the lysosomes of macrophage-like cells, in marked contrast to its highly effective inhibition of LDL oxidation at pH 7.4. LDL oxidation at lysosomal pH was inhibited very effectively for long periods by N,N'-diphenyl-1,4-phenylenediamine, which is more hydrophobic than probucol and has been shown by others to inhibit atherosclerosis in rabbits, and by cysteamine, which is a hydrophilic antioxidant that accumulates in lysosomes. Iron-induced LDL oxidation might be due to the formation of the superoxide radical, which protonates at lysosomal pH to form the much more reactive, hydrophobic hydroperoxyl radical, which can enter LDL and reach its core. Probucol resides mainly in the surface monolayer of LDL and would not effectively scavenge hydroperoxyl radicals in the core of LDL. This might explain why probucol failed to protect against atherosclerosis in various clinical trials. The oxidised LDL hypothesis of atherosclerosis now needs to be re-evaluated using different and more effective antioxidants that protect against the lysosomal oxidation of LDL

Kinetics of GLUT4 Trafficking in Rat and Human Skeletal Muscle

OBJECTIVE—In skeletal muscle, insulin stimulates glucose transport activity three- to fourfold, and a large part of this stimulation is associated with a net translocation of GLUT4 from an intracellular compartment to the cell surface. We examined the extent to which insulin or the AMP-activated protein kinase activator AICAR can lead to a stimulation of the exocytosis limb of the GLUT4 translocation pathway and thereby account for the net increase in glucose transport activity. RESEARCH DESIGN AND METHODS—Using a biotinylated photoaffinity label, we tagged endogenous GLUT4 and studied the kinetics of exocytosis of the tagged protein in rat and human skeletal muscle in response to insulin or AICAR. Isolated ep-itrochlearis muscles were obtained from male Wistar rats. Vastus lateralis skeletal muscle strips were prepared from open muscle biopsies obtained from six healthy men (age 39 11 years an