Saliva Malondialdehyde Concentration of Dogs With and Without Periodontal Disease.

The study investigated whether malondialdehyde (MDA), a biomarker for oxidative stress, can be used as a viable parameter in dog saliva for the diagnosis or early detection of periodontal disease (PD). Saliva MDA concentrations were measured preoperatively in dogs diagnosed with PD during dental prophylaxis and compared with those of dentally healthy dogs. 35 dogs were included in the study.

[Common veterinary practice in small animal anesthesia - an online survey among small animal practitioners in Europe].

Objectives: Survey concerning the situation of small animal anesthesia in Europe and assessment of the compliance with the guidelines of the AVA (American Society of Anesthesiologists) and the DVG specialty group VAINS (Veterinary Anesthesia, Intensive Care, Emergency Medicine, and Pain Management).

Material And Methods: A link to an online survey with questions concerning anesthesia management (topics include demographics, equipment, monitoring, thermal management, pre-anesthetic examination, anesthetic protocol, and others) was sent to small animal practitioners in several countries.

Results: A total of 767 evaluable questionnaires came from Germany (n = 343), Austria (n = 216), Switzerland (n = 83), the United Kingdom (n = 38), France (n = 25), Hungary (n = 25), Scandinavia (n = 23), and "other countries" (n = 11).

Inhibition of the thioredoxin system by PX-12 (1-methylpropyl 2-imidazolyl disulfide) impedes HIV-1 infection in TZM-bl cells.

Human immunodeficiency virus (HIV-1) entry is initiated by the binding between the viral envelope glycoprotein gp120 and the host receptor CD4, and followed by reduction of structural disulfides of gp120 and CD4. The host thioredoxin-1 (Trx1) efficiently reduces disulfides of gp120 and CD4 in vitro, and recently CD4-dependent HIV-1 entry was shown to be inhibited by anti-Trx1-antibodies, indicating a central role for Trx1. 1-methylpropyl-2-imidazolyl disulfide (PX-12) is a reversible inhibitor of the Trx1 system that may also cause a slow irreversible thioalkylation of Trx1.

Three-Dimensional Geometry of Collagenous Tissues by Second Harmonic Polarimetry.

Collagen is a biological macromolecule capable of second harmonic generation, allowing label-free detection in tissues; in addition, molecular orientation can be determined from the polarization dependence of the second harmonic signal. Previously we reported that in-plane orientation of collagen fibrils could be determined by modulating the polarization angle of the laser during scanning. We have now extended this method so that out-of-plane orientation angles can be determined at the same time, allowing visualization of the 3-dimensional structure of collagenous tissues.

The Cellular Thioredoxin-1/Thioredoxin Reductase-1 Driven Oxidoreduction Represents a Chemotherapeutic Target for HIV-1 Entry Inhibition.

Background: The entry of HIV into its host cell is an interesting target for chemotherapeutic intervention in the life-cycle of the virus. During entry, reduction of disulfide bridges in the viral envelope glycoprotein gp120 by cellular oxidoreductases is crucial. The cellular thioredoxin reductase-1 plays an important role in this oxidoreduction process by recycling electrons to thioredoxin-1.

Development and evaluation of a pilot nurse case management model to address multidrug-resistant tuberculosis (MDR-TB) and HIV in South Africa.

Setting: Multidrug-resistant tuberculosis (MDR-TB) unit in KwaZulu-Natal, South Africa.

Objective: To develop and evaluate a nurse case management model and intervention using the tenets of the Chronic Care Model to manage treatment for MDR-TB patients with a high prevalence of human immunodeficiency virus (HIV) co-infection.

Design: A quasi-experimental pilot programme utilizing a nurse case manager to manage care for 40 hospitalized MDR-TB patients, 70% HIV co-infected, during the intensive phase of MDR-TB treatment.

Methodological aspects of ELISA analysis of thioredoxin 1 in human plasma and cerebrospinal fluid.

Thioredoxin-1 (Trx1) is a protein antioxidant involved in major cellular processes. Increased plasma levels of Trx1 have been associated with human diseases suggesting that Trx1 is a marker for oxidative stress with putative clinical use. However, the reported mean levels of Trx1 in the control cohorts vary a hundred-fold between studies (0.

Structural origins of chiral second-order optical nonlinearity in collagen: amide I band.

The molecular basis of nonlinear optical (NLO) chiral effects in the amide I region of type I collagen was investigated using sum-frequency generation vibrational spectroscopy; chiral and achiral tensor elements were separated using different input/output beam polarization conditions. Spectra were obtained from native rat tail tendon (RTT) collagen and from cholesteric liquid crystal-like (LC) type I collagen films. Although RTT and LC collagen both possess long-range order, LC collagen lacks the complex hierarchical organization of RTT collagen.

Is trichloroacetic acid an insufficient sample quencher of redox reactions?

The global protein thiol pool has been reported to play a major role in the defense against oxidative stress as a redox buffer similar to glutathione. The present study uses a novel method to visualize cellular changes of the global protein thiol pool in response to induced oxidative stress. Unexpectedly, the results showed an uneven distribution of protein thiols in resting cells with no apparent change in their level or distribution in response to diamide as has been reported previously.

Thioredoxin-1 and protein disulfide isomerase catalyze the reduction of similar disulfides in HIV gp120.

HIV-1 enters cells via interaction of the viral glycoprotein gp120, the host cell surface receptor CD4 and the co-receptors CCR5 or CXCR4. For entry, gp120 undergoes conformational changes that depend on the reduction of one or more disulfides. Previous studies indicate that protein disulfide isomerase (PDI), thioredoxin-1 (Trx1), and glutaredoxin-1 (Grx1) catalyze gp120 reduction, but their specific disulfide targets are not known.

Aspergillus nidulans contains six possible fatty acyl-CoA synthetases with FaaB being the major synthetase for fatty acid degradation.

Aspergillus nidulans can use a variety of fatty acids as sole carbon and energy sources via its peroxisomal and mitochondrial beta-oxidation pathways. Prior to channelling the fatty acids into beta-oxidation, they need to be activated to their acyl-CoA derivates. Analysis of the genome sequence identified a number of possible fatty acyl-CoA synthetases (FatA, FatB, FatC, FatD, FaaA and FaaB).

AoxA is a major peroxisomal long chain fatty acyl-CoA oxidase required for beta-oxidation in A. nidulans.

Filamentous fungi can use a variety of fatty acids (FA) as sole carbon and energy sources. Aspergillus nidulans has been shown to possess both peroxisomal and mitochondrial beta-oxidation pathways. In these studies, the major peroxisomal long chain fatty acyl coenzyme A oxidase AoxA was identified.

Anulus fibrosus tension inhibits degenerative structural changes in lamellar collagen.

Mechanical stress is one of the risk factors believed to influence intervertebral disc degeneration. Animal models have shown that certain regimes of compressive loading can induce a cascade of biological effects that ultimately results in cellular and structural changes in the disc. It has been proposed that both cell-mediated breakdown of collagen and the compromised stability of collagen with loss of anular tension could result in degradation of lamellae in the anulus fibrosus (AF).

Quantitative analysis of structural disorder in intervertebral disks using second harmonic generation imaging: comparison with morphometric analysis.

A novel signal processing algorithm for quantifying structural disorder in biological tissue using second harmonic generation (SHG) imaging is described. Both the magnitude and the pattern of disorder in collagenous tissues can be determined with this method. Mathematical models are used to determine the range of disordered states over which the algorithm can be used, because highly disordered biological samples do not generate second harmonic signals.

Spectral moment invariant analysis of disorder in polarization-modulated second-harmonic-generation images obtained from collagen assemblies.

Spectral moment invariants (SMIs) are applied, for what we believe to be the first time, to second-harmonic-generation data obtained from biological samples. This method can be used to identify the presence of structural abnormalities in collagenous tissues and also to quantify the extent of the abnormality through analysis of textural deterioration. SMIs are not affected by potentially confounding factors, such as the structural heterogeneity in biological subjects, variability in scan conditions, and differences in scanning techniques.

Sum frequency vibrational spectroscopy: the molecular origins of the optical second-order nonlinearity of collagen.

The molecular origins of second-order nonlinear effects in type I collagen fibrils have been identified with sum-frequency generation vibrational spectroscopy. The dominant contributing molecular groups are: 1), the methylene groups associated with a Fermi resonance between the fundamental symmetric stretch and the bending overtone of methylene; and 2), the carbonyl and peptide groups associated with the amide I band. The noncentrosymmetrically aligned methylene groups are characterized by a distinctive tilt relative to the axis perpendicular to the main axis of the collagen fiber, a conformation producing a strong achiral contribution to the second-order nonlinear effect.

Polarization-modulated second harmonic generation imaging: method for quantitative assessment of disorganization in anulus.

An experimental method for quantifying disorder within the anulus fibrosus is described based on polarization-modulated second harmonic generation imaging (PM-SHG-I). This method is demonstrated by imaging the anular lamellar architecture of a mouse model of compressive loading. Results were consistent with those obtained in an earlier study where organization was quantified directed secants image analysis on photomicrographs.

Advanced glycation endproduct-induced aging of the retinal pigment epithelium and choroid: a comprehensive transcriptional response.

Advanced glycation endproduct (AGE) formation is a trigger for the onset of age-related disease. To evaluate AGE-induced change in the ocular fundus, 5-mo-old C57BL/6 mice were given low-dose D-galactose (D-gal) for 8 wk and evaluated by AGE fluorescence, electroretinography (ERG), electron microscopy, and microarray analysis for 20 wk. Although AGE fluorescence was increased in D-gal-treated retinal pigment epithelium (RPE)-choroid compared with controls at all time points, ERG showed no AGE-induced functional toxicity.

Glycation increases human annulus fibrosus stiffness in both experimental measurements and theoretical predictions.

One of the primary age-related changes to collagenous tissues is the increased concentration of advanced glycation endproducts (AGEs). Although AGEs have been shown to increase the mechanical stiffness of many tissues, their influence on the mechanical properties of the annulus fibrosus has not been measured experimentally. In previous theoretical work, we hypothesized that the mechanical influence of AGEs on the annulus could be represented in an additive strain energy function with a separate crosslinking term, but the material coefficients associated with this term were not correlated with AGE concentration.

Ultrastructural aging of the RPE-Bruch's membrane-choriocapillaris complex in the D-galactose-treated mouse.

Purpose: Low-dose D-galactose treatment in mice induces accelerated aging due to advanced glycation endproduct (AGEs) formation. The purpose of this study was to identify ultrastructural aging in the retinal pigment epithelium (RPE)-Bruch's membrane-choriocapillaris.

Methods: Five-month-old C57Bl6 mice were injected daily with D-galactose or control buffer for 8 weeks.

Quantitative second-harmonic generation microscopy in collagen.

The second-harmonic signal in collagen, even in highly organized samples such as rat tail tendon fascicles, varies significantly with position. Previous studies suggest that this variability may be due to the parallel and antiparallel orientation of neighboring collagen fibrils. We applied high-resolution second-harmonic generation microscopy to confirm this hypothesis.

Polarization-modulated second harmonic generation in collagen.

Collagen possesses a strong second-order nonlinear susceptibility, a nonlinear optical property characterized by second harmonic generation in the presence of intense laser beams. We present a new technique involving polarization modulation of an ultra-short pulse laser beam that can simultaneously determine collagen fiber orientation and a parameter related to the second-order nonlinear susceptibility. We demonstrate the ability to discriminate among different patterns of fibrillar orientation, as exemplified by tendon, fascia, cornea, and successive lamellar rings in an intervertebral disc.

Polarization-dependent optical second-harmonic imaging of a rat-tail tendon.

Using scanning confocal microscopy, we measure the backscattered second harmonic signal generated by a 100 fs laser in rat-tail tendon collagen. Damage to the sample is avoided by using a continuous scanning technique, rather than measuring the signal at discrete points. The second harmonic signal varies by about a factor of 2 across a single cross section of the rat-tail tendon fascicle.

Chronic estradiol treatment attenuates stiffening, glycoxidation, and permeability in rat carotid arteries.

Aging-related changes in vascular stiffening and permeability are associated with cardiovascular disease. We examined the interaction of estradiol on the aging process in vascular tissue from rats by assessing the changes in endothelial layer permeability, arterial compliance, and glycoxidative damage levels. We isolated carotid arteries from ovariectomized (OVX) rats that underwent 1 yr of estrogen treatment with subcutaneous pellets and a subsequent 1 mo of cessation of treatment.