Bone mass and quality in patients with juvenile idiopathic arthritis: longitudinal evaluation of bone-mass determinants by using dual-energy x-ray absorptiometry,peripheral quantitative computed tomography,and quantitative ultrasonography

Introduction

Our objective was to evaluate longitudinally the main bone-mass and quality predictors in young juvenile idiopathic arthritis (JIA) patients by using lumbar spine dual-energy X-ray absorptiometry (DXA) scan, radius peripheral quantitative computed tomography (pQCT), and phalangeal quantitative ultrasonography (QUS) at the same time.

Methods

In total, 245 patients (172 females, 73 males; median age, 15.6 years: 148 oligoarticular, 55 polyarticular, 20 systemic, and 22 enthesitis-related-arthritis (ERA) onset) entered the study. Of these, 166 patients were evaluated longitudinally. Data were compared with two age- and sex-matched control groups.

Results

In comparison with controls, JIA patients, but not with ERA, had a reduced spine bone-mineral apparent density (BMAD) standard deviation score (P < 0.001) and musculoskeletal deficits, with significantly lower levels of trabecular bone mineral density (TrabBMD) (P < 0.0001), muscle cross-sectional area (CSA) (P < 0.005), and density-weighted polar section modulus (SSIp) (P < 0.05). In contrast, JIA showed fat CSA significantly higher than controls (P < 0.0001). Finally, JIA patients had a significant reduced amplitude-dependent speed of sound (AD-SoS) (P < 0.001), and QUS z score (P < 0.005).Longitudinally, we did not find any difference in all JIA patients in comparison with baseline, except for the SSIp value that normalized. Analyzing the treatments, a significant negative correlation among spine BMAD values, TrabBMD, AD-SoS, and systemic and/or intraarticular corticosteroids, and a positive correlation among TNF-α-blocking agents and spine BMAD, TrabBMD, and AD-SoS were observed.

Conclusions

JIA patients have a low bone mass that, after a first increase due to the therapy, does not reach the normal condition over time. The pronounced bone deficits in JIA are greater than would be expected because of reduction in muscle cross-sectional area. Thus, bone alterations in JIA likely represent a mixed defect of bone accrual and lower muscle forces.     

Establishing of a minimal set of tests (minimal standards) to identify species included in the genus Mycobacterium

Mycobacterium genus includes over 100 species and subspecies; new species are discovered every year. Minimal standard criteria are represented by the resistance to acid-alcohol (e.g. in the Ziehl - Neelsen staining), the presence of some mycolic acids containing 60-90 carbon atoms that can be cleaved by pyrolysis in fatty acids with 22 - 26 carbon atoms and a guanine + cytosine content of the DNA of 61 to 71 mol %. The species with the highest rate of involvement are those from Mycobacterium tuberculosis complex, and tuberculosis is still one of the most widespread world diseases. The most important for a laboratory is to be able to identify the species from M. tuberculosis complex. We have done a series of experiments, their goal being to evaluate and establish a minimal set of useful tests for identification of mycobacterial species. We used strains from "Cantacuzino" Institute collection and applied a series of classical and modern methods. We appreciate that the minimal set of tests could be represented by the microscopic examination for acid-fast bacilli (AFB), the examination for the preferred growth temperature, the growth rate, the colonies morphology, pigmentation and photo reactivity, the niacin accumulation test, the test of nitrate reduction, the catalase test (in both variants), plus the susceptibility to Para-Amino Salicylic Acid, Para-Nitro-Benzoic Acid andto Tiophene-2-Carboxylic Acid Hydrazide.     

Cadmium tolerance and adsorption by the marine brown alga Fucus vesiculosus from the Irish Sea and the Bothnian Sea

Cadmium (Cd) uptake capacities and Cd tolerance of the marine alga Fucus vesiculosus from the Irish Sea (salinity 35 psu) and from the Bothnian Sea (northern Baltic, 5 psu) were quantified. These data were complemented by measurements of changes in maximal photosynthetic rate (P(max)), dark respiration rate and variable fluorescence vs. maximal fluorescence (F(v):F(m)). At concentrations between 0.01 and 1 mmol Cd l(-1), F. vesiculosus from the Bothnian Sea adsorbed significantly more (about 98%) Cd compared with F. vesiculosus from the Irish Sea. The photosynthetic measurements showed that the Bothnian Sea F. vesiculosus were more sensitive to Cd exposure than the Irish Sea algae. The algae from the Irish Sea showed negative photosynthetic effects only at 1 mmol Cd l(-1), which was expressed as a decreased P(max) (-12.3%) and F(v):F(m) (-4.6%). On the contrary, the algae from the Bothnian Sea were negatively affected already at Cd concentrations as low at 0.1 mmol Cd l(-1). They exhibited increased dark respiration (+11.1%) and decreased F(v):F(m) (-13.9%). The results show that F. vesiculosus from the Bothnian Sea may be an efficient sorption substrate for Cd removal from Cd contaminated seawater and this algae type may also have applications for wastewater treatment.     

New pyrimido[5,4-b]indoles and [1]benzothieno[3,2-d]pyrimidines: high affinity ligands for the alpha(1)-adrenoceptor subtypes

A number of new pyrimido[5,4-b]indole and [1]benzothieno[3,2-d]pyrimidine derivatives were synthesized and evaluated for their binding and functional properties at alpha(1)-adrenergic receptor (alpha(1)-AR) subtypes. They behaved as potent alpha(1)-AR antagonists. In binding experiments, some of them (RC24 and RC23) showed very high affinity for the alpha(1D)-AR subtype.     

A nuclear magnetic resonance study of the diastereoisomer complexes formed between a terguride derivative and naproxen

¹H NMR (600 MHz) measurements of chemical shift changes were made in acidified (DCI) CD₃OD/D₂O 1:9 v/v equimolar solutions of (S)- and (R,S)-6-methoxy-α-methyl-2-naphthaleneacetic acid (naproxen) in the presence of 1-(3-aminopropyl)-(5R,8S,10R)-terguride (AMP-TER). The most significant bonding interactions concurring to the formation of diastereoisomer complexes are seen as chemical shifts in proximity to the positively charged nitrogen N(6)-CH₃ and of H(12), H(13), H(14) protons of the ergoline skeleton, both the adducts having an electrostatic term and different π–π stabilizing interactions. Chemical shift data exclude any contribution of the aminopropyl chain to the chiral recognition mechanism. These findings provide an experimental basis for the enantiodiscriminative process accounting for the observed chromatographic resolutions of arylcarboxylic acids on chiral stationary phases derived from AMP-TER. © 1994 Wiley-Liss, Inc.     

Oxygen Radical Injury and Loss of High-Energy Compounds in Anoxic and Reperfused Rat Heart: Prevention By Exogenous Fructose-1, 6-Bisphosphate

Isolated Langendorff-perfused rat hearts after 10 minutes preperfusion, were subjected to a substrate-free anoxic perfusion (20 minutes) followed by 20 minutes reperfusion with a glucose-containing oxygen-balanced medium. Under the same perfusion conditions, the effect of exogenous 5mM fructose-1, 6-bisphosphate has been investigated. The xanthine dehydrogenase to xanthine oxidase ratio, concentrations of high-energy phosphates and the TBA-reactive material (TBARS) were determined at the end of each perfusion period in both control and fructose-1, 6-bisphosphate-treated hearts. Results indicate that anoxia induces the irreversible transformation of xanthine dehydrogenase into oxidase as a consequence of the sharp decrease of the myocardial energy metabolism. This finding is supported by the protective effect exerted by exogenous fructose-1, 6-bisphosphate which is able to maintain the correct xanthine dehydrogenase/oxidase ratio by preventing the depletion of phosphorylated compounds during anoxia. Moreover, in control hearts, the release oflactate dehydrogenase during reperfusion, is paralleled by a 50% increase in the concentration of tissue TBARS. On the contrary, in fructose-1, 6-bisphosphate-treated hearts this concentration does not significantly change after reoxygenation, while a slight but significant increase of lactate dehydrogenase activity in the perfusates is observed.

On the whole these data indicate a direct contribution of oxygen-derived free radicals to the worsening of post-anoxic hearts. A hypothesis on the mechanism of action of fructose-1, 6-bisphosphate in anoxic and reperfused rat heart and its possible application in the clinical therapy of myocardial infarction are presented.