Oxidative stress and metallothionein expression in the liver of rats with severe thermal injury

The aim of this work was to study oxidative stress and the compensating mechanisms implicated in severe thermal injury using the burned rat model. Results showed that after thermal injury glutathione (GSH) level was decreased, oxidized glutathione (GSSG) and the ratio of GSSG/GSH increased both at 24 and 48 h in the liver. The activities of GSH-reductase (GSH-Rx) in the liver and GSH-peroxidase (GSH-Px) both in the liver and erythrocytes increased at 24 h and then decreased at 48 h. The level of alpha-tocopherol in plasma was reduced at 24 h. Lipid peroxide levels increased both at 24 and 48 h in the liver. The serum zinc level decreased, reaching a minimum at 12h, whereas liver zinc level was elevated and reached the maximum at 12 h. After severe thermal injury enhancement of metallothionein (MT) expression has been discovered for the first time. MT content in the liver increased both at 24 and 48 h. Expression of MT-I mRNA was activated at 3 h and reached the top at 24 h postburn. The conclusion is that severe thermal injury gives rise to oxidative stress and dramatic enhancement of MT expression could be one of the important compensative mechanisms of natural defense system postburn.

A COOH-terminal peptide confers regiospecific orientation and facilitates atomic force microscopy of an IgG1

An antibody (IgG1) was designed for oriented adherence to a metal-containing surface. This was achieved by adding a metal-chelating peptide, (CP = His-Trp-His-His-His-Pro), to the COOH-terminus of the heavy chain through genetic engineering. Electroporation of the engineered heavy chain gene into cells expressing the complimentary light chain yielded colonies secreting an intact antibody containing the metal-chelating peptide (IgG1-CP) which had high affinity for a nickel-loaded iminodiacetate column. Purified IgG1-CP was bound to nickel-treated mica and imaged by atomic force microscopy (AFM). Antibody lacking the COOH-terminal metal binding peptide failed to produce discernible AFM images. The AFM images of individual IgG1-CP molecules and their calculated dimensions demonstrated that regiospecific binding and uniform orientation of the antibody was imparted by the peptide. The ability to stably orient macromolecules in their native state to a surface may be used advantageously to visualize them.

Reversible encephalopathy after cardiac transplantation: histologic evidence of endothelial activation, T-cell specific trafficking, and vascular endothelial growth factor expression

Reversible encephalopathy after transplantation is well recognized. The condition is commonly thought to be related to immune suppression, and a characteristic brain imaging pattern is typically recognized with vasogenic edema in the parietal and occipital regions, typically termed posterior reversible encephalopathy syndrome (PRES). We report the case of a patient with reversible encephalopathy after cardiac transplantation with brain biopsy evidence of endothelial activation, selective intravascular/perivascular T-cell trafficking, and VEGF expression in astrocytes, neurons, and the endothelium.

Estimates of quantitative genetic parameters of immunological traits in the chicken

Three in vivo assays were used to measure the immunocompetence of chickens in two generations of a selection experiment. The obtained data were used to estimate the variance components for sire and dam for antibody production to Pasteurella multocida and Mycoplasma gallisepticum vaccines, for T-cell-mediated immunity evaluated by a phytohemagglutinin wing web assay, and for clearance of foreign particles from the circulatory system. Heritabilities of and genetic correlations among these immunological traits were calculated from the sire variance components. Heritability estimates of the immunological traits based on the sire component of variance ranged from .06 to .53, and genetic correlations among immunological traits were generally negative.

Tumor suppressor p53 is a negative regulator in thyroid hormone receptor signaling pathways

Thyroid hormone nuclear receptors (TRs) are ligand-dependent transcription factors which regulate growth, differentiation, and development. The molecular mechanisms by which TRs mediate these diverse effects are unclear. One emerging hypothesis suggests that TRs could mediate these diverse effects via cooperation with different transcription factors/receptors. Indeed, we have recently shown that the human TR subtype beta1 (h-TRbeta1) interacts with the tumor suppressor p53. p53 is a transcription factor that plays a critical role in cell cycle regulation and tumor development. To assess the physiological relevance of the interaction of h-TRbeta1 with p53, the present study addressed the question as to whether the functions of h-TRbeta1 could be modulated by p53. We first compared the h-TRbeta1-mediated transcriptional activity in two pairs of isogenic cell lines, RKO/RKO E6 and MCF-7/MCF-7 E6. RKO and MCF-7 cells are colon and breast carcinoma cell lines, respectively, that contain p53 but lack TRbeta1. The isogenic RKO E6 and MCF-7 E6 cells are stable clones expressing high levels of papillomavirus type 16 E6 protein. In these cells, the level of p53 protein was lower than the parental cells. The impairment of p53 functions in these E6-containing cells led to an activation of TRbeta1-mediated transcriptional activity. Furthermore, in a growth hormone-producing cell line in which the expression of the growth hormone gene is positively regulated by TRs, overexpression of the wild-type p53 led to repression in the expression of the growth hormone gene. Thus, TRs could cross-talk with p53 in its signaling pathways to regulate gene regulatory functions. The present findings further strengthen the hypothesis that mediation of the pleiotropic effects of T3 requires the cooperation of TRs with a large network of transcription factors.

Measuring gene-specific nucleotide excision repair in human cells using quantitative amplification of long targets from nanogram quantities of DNA

We have been developing a rapid and convenient assay for the measurement of DNA damage and repair in specific genes using quantitative polymerase chain reaction (QPCR) methodology. Since the sensitivity of this assay is limited to the size of the DNA amplification fragment, conditions have been found for the quantitative generation of PCR fragments from human genomic DNA in the range of 6-24 kb in length. These fragments include: (1) a 16.2 kb product from the mitochondrial genome; (2) 6.2, 10.4 kb, and 15.4 kb products from the hprt gene, and (3) 13.5, 17.7, 24.2 kb products from the human beta-globin gene cluster. Exposure of SV40 transformed human fibroblasts to increasing fluences of ultraviolet light (UV) resulted in the linear production of photoproducts with 10 J/m(2) of UVC producing 0.085 and 0.079 lesions/kb in the hprt gene and the beta-globin gene cluster, respectively. Kinetic analysis of repair following 10 J/m(2) of UVC exposure indicated that the time necessary for the removal of 50% of the photoproducts, in the hprt gene and beta-globin gene cluster was 7.8 and 24.2 h, respectively. Studies using lymphoblastoid cell lines show very little repair in XPA cells in both the hprt gene and beta-globin locus. Preferential repair in the hprt gene was detected in XPC cells. Cisplatin lesions were also detected using this method and showed slower rates of repair than UV-induced photoproducts. These data indicate that the use of long targets in the gene-specific QPCR assay allows the measurement of biologically relevant lesion frequencies in 5-30 ng of genomic DNA. This assay will be useful for the measurement of human exposure to genotoxic agents and the determination of human repair capacity.

Do the American Society of Clinical Oncology Value Framework and the European Society of Medical Oncology Magnitude of Clinical Benefit Scale Measure the Same Construct of Clinical Benefit?

Purpose Whether the ASCO Value Framework and the European Society for Medical Oncology (ESMO) Magnitude of Clinical Benefit Scale (MCBS) measure similar constructs of clinical benefit is unclear. It is also unclear how they relate to quality-adjusted life-years (QALYs) and funding recommendations in the United Kingdom and Canada. Methods Randomized clinical trials of oncology drug approvals by the US Food and Drug Administration, European Medicines Agency, and Health Canada between 2006 and August 2015 were identified and scored using the ASCO version 1 (v1) framework, ASCO version 2 (v2) framework, and ESMO-MCBS by at least two independent reviewers. Spearman correlation coefficients were calculated to assess construct (between frameworks) and criterion validity (against QALYs from the National Institute for Health and Care Excellence [NICE] and the pan-Canadian Oncology Drug Review [pCODR]). Associations between scores and NICE/pCODR recommendations were examined. Inter-rater reliability was assessed using intraclass correlation coefficients. Results From 109 included randomized clinical trials, 108 ASCOv1, 111 ASCOv2, and 83 ESMO scores were determined. Correlation coefficients for ASCOv1 versus ESMO, ASCOv2 versus ESMO, and ASCOv1 versus ASCOv2 were 0.36 (95% CI, 0.15 to 0.54), 0.17 (95% CI, -0.06 to 0.37), and 0.50 (95% CI, 0.35 to 0.63), respectively. Compared with NICE QALYs, correlation coefficients were 0.45 (ASCOv1), 0.53 (ASCOv2), and 0.46 (ESMO); with pCODR QALYs, coefficients were 0.19 (ASCOv1), 0.20 (ASCOv2), and 0.36 (ESMO). None of the frameworks were significantly associated with NICE/pCODR recommendations. Inter-rater reliability was good for all frameworks. Conclusion The weak-to-moderate correlations of the ASCO frameworks with the ESMO-MCBS, as well as their correlations with QALYs and with NICE/pCODR funding recommendations, suggest different constructs of clinical benefit measured. Construct convergent validity with the ESMO-MCBS did not increase with the updated ASCO framework.

Multi-locus interactions predict risk for post-PTCA restenosis: an approach to the genetic analysis of common complex disease

The complexity of recognizing the potential contribution of a number of possible predictors of complex disorders is increasingly challenging with the application of large-scale single nucleotide polymorphism (SNP) typing. In the search for putative genetic factors predisposing to coronary artery restenosis following balloon angioplasty, we determined genotypes for 94 SNPs representing 62 candidate genes, in a prospectively assembled cohort of 342 cases and 437 controls. Using a customized coupled-logistic regression procedure accounting for both additive and interactive effects, we identified seven SNPs in seven genes that, together, showed a statistically significant association with restenosis incidence (P <0.0001), accounting for 11.6% of overall variance observed. Among them are candidate genes for cardiovascular pathophysiology (apolipoprotein-species and NOS), inflammatory response (TNF receptor and CD14), and cell-cycle control (p53 and p53-associated protein). Our results emphasize the need to account for complex multi-gene influences and interactions when assessing the molecular pathology of multifactorial medical entities.

NAGLU mutations underlying Sanfilippo syndrome type B

Sanfilippo syndrome type B (mucopolysaccharidosis III B) is a rare autosomal recessive disease caused by deficiency of alpha-N-acetylglucosaminidase, one of the enzymes required for the lysosomal degradation of heparan sulfate. The gene for this enzyme, NAGLU, recently was isolated, and several mutations were characterized. We have identified, in amplified exons from nine fibroblast cell lines derived from Sanfilippo syndrome type B patients, 10 additional mutations: Y92H, P115S, Y140C, E153K, R203X, 650insC, 901delAA, P358L, A664V, and L682R. Four of these mutations were found in homozygosity, and only two were seen in more than one cell line. Thus, Sanfilippo syndrome type B shows extensive molecular heterogeneity. Stable transfection of Chinese hamster ovary cells, by cDNA mutagenized to correspond to the NAGLU missense mutations, did not yield active enzyme, demonstrating the deleterious nature of the mutations. Nine of the 10 amino acid substitutions identified to date are clustered near the amino or the carboxyl end of alpha-N-acetylglucosaminidase, suggesting a role for these regions in the transport or function of the enzyme.

The effect of delipidated deglycolipidated (DDMV) and heat-killed Mycobacterium vaccae in asthma

Experimental and epidemiological evidence supports the hypothesis that exposure to mycobacteria has the potential to suppress the development of asthma and/or atopy and there are reports in the Chinese medical literature of repeated vaccination with inactivated BCG being effective in the management of asthma. Forty-three patients with stable moderately severe asthma who were skin prick test positive to house dust mite were randomized to receive two intradermal injections of either phosphate-buffered saline (placebo), heat-killed Mycobacterium vaccae (0.5 mg), or delipidated deglycolipidated Mycobacterium vaccae (DDMV) (0.05 mg). Markers of asthma severity were measured for 3 mo and blood eosinophil, IgE levels, and the T cell proliferative and cytokine responses were monitored. There were no significant differences between either treatment group and the placebo group for any of the outcome variables. There was also no difference between the treatment groups and placebo for eosinophil, IgE levels, or the T cell proliferative and cytokine response. The results indicate no effect of low dose intradermal DDMV or M. vaccae on asthma severity in patients with established asthma.

MR Elastography Can Be Used to Measure Brain Stiffness Changes as a Result of Altered Cranial Venous Drainage During Jugular Compression

BACKGROUND AND PURPOSE

Compressing the internal jugular veins can reverse ventriculomegaly in the syndrome of inappropriately low pressure acute hydrocephalus, and it has been suggested that this works by "stiffening" the brain tissue. Jugular compression may also alter blood and CSF flow in other conditions. We aimed to understand the effect of jugular compression on brain tissue stiffness and CSF flow.

MATERIALS AND METHODS

The head and neck of 9 healthy volunteers were studied with and without jugular compression. Brain stiffness (shear modulus) was measured by using MR elastography. Phase-contrast MR imaging was used to measure CSF flow in the cerebral aqueduct and blood flow in the neck.

RESULTS

The shear moduli of the brain tissue increased with the percentage of blood draining through the internal jugular veins during venous compression. Peak velocity of caudally directed CSF in the aqueduct increased significantly with jugular compression (P < .001). The mean jugular venous flow rate, amplitude, and vessel area were significantly reduced with jugular compression, while cranial arterial flow parameters were unaffected.

CONCLUSIONS

Jugular compression influences cerebral CSF hydrodynamics in healthy subjects and can increase brain tissue stiffness, but the magnitude of the stiffening depends on the percentage of cranial blood draining through the internal jugular veins during compression—that is, subjects who maintain venous drainage through the internal jugular veins during jugular compression have stiffer brains than those who divert venous blood through alternative pathways. These methods may be useful for studying this phenomenon in patients with the syndrome of inappropriately low-pressure acute hydrocephalus and other conditions.

The structure of networks that produce the transformation from grid cells to place cells

Since grid cells were discovered in the medial entorhinal cortex, several models have been proposed for the transformation from periodic grids to the punctate place fields of hippocampal place cells. These prior studies have each focused primarily on a particular model structure. By contrast, the goal of this study is to understand the general nature of the solutions that generate the grids-to-places transformation, and to exploit this insight to solve problems that were previously unsolved. First, we derive a family of feedforward networks that generate the grids-to-places transformations. These networks have in common an inverse relationship between the synaptic weights and a grid property that we call the normalized offset. Second, we analyze the solutions of prior models in terms of this novel measure and found to our surprise that almost all prior models yield solutions that can be described by this family of networks. The one exception is a model that is unrealistically sensitive to noise. Third, with this insight into the structure of the solutions, we then construct explicitly solutions for the grids-to-places transformation with multiple spatial maps, that is, with place fields in arbitrary locations either within the same (multiple place fields) or in different (global remapping) enclosures. These multiple maps are possible because the weights are learned or assigned in such a way that a group of weights contributes to spatial specificity in one context but remains spatially unstructured in another context. Fourth, we find parameters such that global remapping solutions can be found by synaptic learning in spiking neurons, despite previous suggestions that this might not be possible. In conclusion, our results demonstrate the power of understanding the structure of the solutions and suggest that we may have identified the structure that is common to all robust solutions of the grids-to-places transformation.

Two year follow up of pulmonary function values among welders in New Zealand

OBJECTIVES

To examine whether welding is a risk factor for an accelerated decline in pulmonary function.

METHODS

2 Year follow up of pulmonary function and respiratory symptoms among 54 welders and 38 non-welders in eight New Zealand welding sites.

RESULTS

There were no significant differences in age, height, smoking habits, ethnicity, or total time in industrial work between welders and non-welders. No overall differences were noted in the changes of pulmonary function variables between the two study groups. However, when the comparison was restricted to smokers, welders had a significantly greater (p = 0.02) annual decline (88.8 ml) in FEV1 than non-welders, who had a slight non-significant annual increase (34.2 ml). Also, welders without respiratory protection or local exhaust ventilation while welding had a greater annual decline both in forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) than welders with protection (p = 0.001 and 0.04, respectively). Among welders a significant association was found between the acute across shift change and the annual decline in FEV1. Chronic bronchitis was more common among welders (24%) than non-welders (5%). Only one welder (2%) but eight non-welders (21%) reported having asthma.

CONCLUSIONS

Welders who smoked and welders working without local exhaust ventilation or respiratory protection have an increased risk of accelerated decline in FEV1.

Expression of thyroid hormone receptors is disturbed in human renal clear cell carcinoma

Human renal clear cell carcinoma (RCCC) accounts for up to 2% of human cancers. To find out if thyroid hormone (T3) and its receptors (TRs) play a role in tumorigenesis of RCCC, the expression of TRs was evaluated on mRNA and protein level. It was found that TRalpha (both alpha1 and alpha2) mRNA amount was significantly decreased in tumors while compared with healthy kidney tissue, and this decrease was deepest in G1 (well differentiated) RCCCs. In contrast, TRalpha1 protein was 1.6x overexpressed in tumors. TRbeta1 mRNA amount was overexpressed in 30% and significantly decreased in 70% of examined tumors. On the protein level, TRbeta1 amount was 1.7x lower in tumors than in healthy controls.

The impact of pretransplant mechanical ventilation on short- and long-term survival after lung transplantation

Lung transplantation in mechanically ventilated (MV) patients has been associated with decreased posttransplant survival. Under the Lung Allocation Score (LAS) system, patients at greatest risk of death on the waiting list, particularly those requiring MV, are prioritized for lung allocation. We evaluated whether pretransplant MV is associated with poorer posttransplant survival in the LAS era. Using a national registry, we analyzed all adults undergoing lung transplantation in the United States from 2005 to 2010. Propensity scoring identified nonventilated matched referents for 419 subjects requiring MV at the time of transplantation. Survival was evaluated using Kaplan-Meier methods. Risk of death was estimated by hazard ratios employing time-dependent covariates. We found that pretransplant MV was associated with decreased overall survival after lung transplantation. In the first 6 months posttransplant, ventilated subjects had a twofold higher risk of death compared to nonventilated subjects. However, after 6 months posttransplant, survival did not differ by MV status. We also found that pretransplant MV was not associated with decreased survival in noncystic fibrosis obstructive lung diseases. These results suggest that under the LAS, pretransplant MV is associated with poorer short-term survival posttransplant. Notably, the increased risk of death appears to be strongest the early posttransplant period and limited to certain pretransplant diagnoses.

Expression and function of HLA-DQ8 (DQA1*0301/DQB1*0302) genes in transgenic mice

Transgenic mice expressing HLA-DQA1*0301 and HLA-DQB1*0302 genes (DQ8) were produced. The transgenes were then transferred into mouse (Ab degrees) class II negative mice: the only class II molecules expressed in these animals were therefore coded by the HLA-DQ8 genes. Good expression of HLA-DQ molecules was found. Both CD4+ T cells and DQ8-specific T-cell receptor V beta expressing cells were positively selected in these mice. The HLA-DQ8 molecules expressed in these animals can present various foreign and self antigens and induce T-cell proliferation in vitro. These mice will be invaluable in future studies of the structure and function of HLA-DQ8 genes.

An economic analysis of patients with active arterial peptic ulcer hemorrhage treated with endoscopic heater probe, injection sclerosis, or surgery in a prospective, randomized trial

BACKGROUND

There are no published, detailed assessments of the direct costs of endoscopic hemostasis for actively bleeding peptic ulcers. We compared the direct costs of care for patients with active ulcer hemorrhage treated with endoscopic or medical-surgical therapies and correlated these costs with patient outcomes.

METHODS

In a prospective, randomized, controlled trial, 31 patients with active ulcer hemorrhage at emergency endoscopy were randomly assigned to heater probe, injection, or medical-surgical treatment. For further ulcer bleeding, heater probe and injection patients were re-treated endoscopically and medical-surgical patients were referred for surgery. Direct costs were estimated using fixed and variable costs for resources consumed and Medicare reimbursement rates for physician fees.

RESULTS

Compared to medical-surgical treatment, the heater probe and injection groups had significantly higher primary hemostasis rates (100% and 90% vs 8%) and lower rates of emergency surgery (0% and 10% vs 75%), blood transfusions, and median direct costs per patient ($4153 and $5247 vs $11,149). Furthermore, compared to medical-surgical treatment, the heater probe group had a significantly lower incidence of severe ulcer rebleeding (11% vs 75%).

CONCLUSIONS

Heater probe and injection sclerosis are similarly efficacious treatments for active ulcer hemorrhage, and both treatments yield significantly lower direct costs of medical care and cost savings.

High-dose isoniazid therapy for isoniazid-resistant murine Mycobacterium tuberculosis infection

The use of isoniazid (INH) for the treatment of INH-resistant Mycobacterium tuberculosis infection has been controversial. The purpose of the present studies was to determine if there is a dose response with INH for INH-susceptible M. tuberculosis Erdman (ATCC 35801), and whether high-dose INH (100 mg/kg of body weight) was more effective than standard-dose INH (25 mg/kg) for therapy of tuberculosis infections caused by INH-resistant mutants of M. tuberculosis Erdman. Six-week-old CD-1 mice were infected with approximately 10(7) viable mycobacteria. Early control groups of infected but untreated mice were euthanized by CO(2) inhalation 1 week later when treatment was initiated. INH (25, 50, 75, and 100 mg/kg) was given by gavage 5 days/week for 4 weeks. Late control groups of untreated mice and treated mice were sacrificed 2 days after the last dose of drug. Spleens and right lungs were removed aseptically and homogenized, and viable cell counts were determined by titration on 7H10 agar plates. In the next study, INH at 100 mg/kg was compared to INH at 25 mg/kg against an isogenic mutant of M. tuberculosis Erdman (INH MIC, 2 microg/ml) and the parent strain. This mutant was found to have a mutation in the KatG protein (Phe to Leu at position 183). In the first study, there was no dose response with increasing doses of INH. In the second study, there was no significant difference between the reduction of viable cell counts for mice treated with INH at 100 mg/kg and that for mice treated with INH at 25 mg/kg (parent or INH-resistant mutant). These preliminary results suggest that INH may be useful in combination therapy of M. tuberculosis infections caused by low-level INH-resistant organisms (INH MICs, 0.2 to 5 microg/ml) and that higher doses of INH are unlikely to be more efficacious than the standard 300-mg/day dose.

Pretreatment with cationic lipid-mediated transfer of the Na+K+-ATPase pump in a mouse model in vivo augments resolution of high permeability pulmonary oedema

Resolution of pulmonary oedema is mediated by active absorption of liquid across the alveolar epithelium. A key component of this process is the sodium-potassium ATPase (Na+K+-ATPase) enzyme located on the basolateral surface of epithelial cells and up-regulated during oedema resolution. We hypothesised that lung liquid clearance could be further up-regulated by lipid-mediated transfer and expression of exogenous Na+K+-ATPase cDNA. We demonstrate proof of this principle in a model of high permeability pulmonary oedema induced by intraperitoneal injection of thiourea (2.5 mg/kg) in C57/BL6 mice. Pretreatment of mice (24 h before thiourea) by nasal sniffing of cationic liposome (lipid #67)-DNA complexes encoding the alpha and beta subunits of Na+K+-ATPase (160 microg per mouse), significantly (P<0.01) decreased the wet:dry weight ratios measured 2 h after thiourea injection compared with control animals, pretreated with an equivalent dose of an irrelevant gene. Whole lung Na+K+-ATPase activity was significantly (P<0.05) increased in mice pretreated with Na+K+-ATPase cDNA compared both with untreated control animals as well as animals pretreated with the irrelevant gene. Nested RT-PCR on whole lung homogenates confirmed gene transfer by detection of vector-specific mRNA in three of four mice studied 24 h after gene transfer. This demonstration of a significant reduction in pulmonary oedema following in vivo gene transfer raises the possibility of gene therapy as a novel, localised approach for pulmonary oedema in clinical settings such as ARDS and lung transplantation.