The structural stabilization of the κ three-way junction by Mg(II) represents the first step in the folding of a group II intron.

Folding of group II introns is characterized by a first slow compaction of domain 1 (D1) followed by the rapid docking of other domains to this scaffold. D1 compaction initiates in a small subregion encompassing the κ and ζ elements. These two tertiary elements are also the major interaction sites with domain 5 to form the catalytic core.

Effect of cholecalciferol as adjunctive therapy with insulin on protective immunologic profile and decline of residual β-cell function in new-onset type 1 diabetes mellitus.

Objective: To evaluate the effect of vitamin D3 on cytokine levels, regulatory T cells, and residual β-cell function decline when cholecalciferol (vitamin D3 administered therapeutically) is given as adjunctive therapy with insulin in new-onset type 1 diabetes mellitus (T1DM).

Design And Setting: An 18-month (March 10, 2006, to October 28, 2010) randomized, double-blind, placebo-controlled trial was conducted at the Diabetes Center of São Paulo Federal University, São Paulo, Brazil.

Participants: Thirty-eight patients with new-onset T1DM with fasting serum C-peptide levels greater than or equal to 0.

HIV-1 induces NALP3-inflammasome expression and interleukin-1β secretion in dendritic cells from healthy individuals but not from HIV-positive patients.

Objective: NALP3-inflammasome is an innate mechanism, alternative to type-1 interferon, which is able to recognize nucleic acids and viruses in the cytoplasm and to induce pro-inflammatory response. Here, we hypothesized the involvement of inflammasome in the early defense against HIV-1 and in the full maturation of dendritic cells: for this, we evaluated the response of dendritic cells pulsed with HIV-1 in terms of inflammasome activation in healthy donors. Moreover, inflammasome response to HIV was evaluated in HIV-infected individuals.

A nickel hydride complex in the active site of methyl-coenzyme m reductase: implications for the catalytic cycle.

Methanogenic archaea utilize a specific pathway in their metabolism, converting C1 substrates (i.e., CO2) or acetate to methane and thereby providing energy for the cell.

Enhanced removal from the plasma of LDL-like nanoemulsion cholesteryl ester in trained men compared with sedentary healthy men.

The objective of this study was to evaluate the effects of exercise training on plasma removal of a cholesterol-rich nanoemulsion (LDE) that mimics low-density lipoprotein (LDL) lipid structure and binds to LDL receptors. LDE-derived cholesteryl ester plasma kinetics was studied in 24 exercise-trained and 20 sedentary male subjects. LDE labeled with [(14)C]cholesteryl ester was injected intravenously, and plasma samples were collected over a 24-h period to determine radioisotope decay curves.

Matrix effects on copper(II)phthalocyanine complexes. A combined continuous wave and pulse EPR and DFT study.

The effect of the electron withdrawing or donating character of groups located at the periphery of the phthalocyanine ligand, as well as the influence of polar and nonpolar solvents are of importance for the redox chemistry of metal phthalocyanines. Continuous wave and pulse electron paramagnetic resonance and pulse electron nuclear double resonance spectroscopy at X- and Q-band are applied to investigate the electronic structure of the complexes Cu(II)phthalocyanine (CuPc), copper(II) 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (CuPc(t)), and copper(II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine (CuPc(F)) in various matrices. Isotope substitutions are used to determine the g values, the copper hyperfine couplings and the hyperfine interactions with the 14N, 1H and 19F nuclei of the macrocycle and the surrounding matrix molecules.

Spin density and coenzyme M coordination geometry of the ox1 form of methyl-coenzyme M reductase: a pulse EPR study.

Methyl-coenzyme M reductase (MCR) catalyses the reduction of methyl-coenzyme M (CH3-S-CoM) with coenzyme B (H-S-CoB) to CH4 and CoM-S-S-CoB in methanogenic archaea. Here we present a pulse EPR study of the "ready" form MCR(ox1), providing a detailed description of the spin density and the coordination of coenzyme M (CoM) to the Ni cofactor F430. To achieve this, MCR was purified from cells grown in a 61Ni enriched medium and samples were prepared in D2O with the substrate analogue CoM either deuterated in the beta-position or with 33S in the thiol group.

Coenzyme B induced coordination of coenzyme M via its thiol group to Ni(I) of F430 in active methyl-coenzyme M reductase.

Methyl-coenzyme M reductase (MCR) catalyzes the reaction of methyl-coenzyme M (CH3-S-CoM) with coenzyme B (HS-CoB) to methane and CoM-S-S-CoB. At the active site, it contains the nickel porphinoid F430, which has to be in the Ni(I) oxidation state for the enzyme to be active. How the substrates interact with the active site Ni(I) has remained elusive.

Characterization of the MCRred2 form of methyl-coenzyme M reductase: a pulse EPR and ENDOR study.

Methyl-coenzyme M reductase (MCR), which catalyses the reduction of methyl-coenzyme M (CH(3)-S-CoM) with coenzyme B (H-S-CoB) to CH(4) and CoM-S-S-CoB, contains the nickel porphinoid F430 as prosthetic group. The active enzyme exhibits the Ni(I)-derived axial EPR signal MCR(red1) both in the absence and presence of the substrates. When the enzyme is competitively inhibited by coenzyme M (HS-CoM) the MCR(red1) signal is partially converted into the rhombic EPR signal MCR(red2).

Adverse effects of topical antiglaucomatous medications on the conjunctiva and the lachrymal (Brit. Engl) response.

Background: Increasing evidence indicates that long-term use of topically administered medication can induce changes in the conjunctiva and lachrymal function.

Methods: In order to evaluate changes in the conjunctiva and lachrymal response after prolonged use of topically administered antiglaucoma medications and preservatives found in antiglaucomatous medication solutions (benzalkonium chloride), we tested lachrymal function (Schirmer I., Jones, BUT, Ferning tests) and used the conjunctival impression cytology technique.

Cyclosporine C: a study of wound-healing modulation after trabeculectomy in rabbit.

The authors studied the clinical and histological effects of cyclosporine instilled after filtering surgery. Its efficacy and variety of advantages compared to other antimitotic agents encourage its use.

The relationship between pupil diameter and decentration in myopia.

Since optical zone centration is of such importance in refractive surgery, we have studied, with a computer-aided videopupillograph, the problem of identifying it in myopes. The findings of pupil centre shift as a function of pupil diameter and degree of myopia are reported in two groups of myopes (low and medium) and a control group. Results indicate that the amount and direction of decentration vary according to pupil diameter and degree of myopia.

[Changes in adrenergic innervation of the choroid during aging].

Background: Aging causes loss of neurons and adrenergic nerve termination in various human organism systems and apparatus. The aim of this work is the observation of qualitative and quantitative differences in the orientation and density of the human choroid adrenergic innervation in relation to age.

Methods: The choroid specimens were taken from the corresponding sectors of the eyeballs of four patients aged between 70 and 75 years and patients aged between 40 and 45 years.

Conjunctiva and subconjunctival tissue in primary open-angle glaucoma after long-term topical treatment: an immunohistochemical and ultrastructural study.

Background: Primary open-angle glaucoma is commonly treated with long-term hypotensive medical therapy. When this approach becomes inadequate, therapy proceeds with surgery. The present study investigates morphological changes in the conjunctival and subconjunctival tissues induced by short- and long-term topical medical therapy of primary open-angle glaucoma.

Neuronal populations in the spinal cord during ageing.

The sensory and motor fibres of the spinal cord and the relative centres of integration were studied during ageing. Sections of spinal cord and ganglia from C8 to T12 of rats aged 6 and 24 months were treated using several techniques: Nissl, NADPH-diaphorase, and antibodies to enkephalins, substance P and neuropeptide Y. Nissl staining of the C8 segment showed that in the aged rat the dorsal horn was more oblique and narrow, the central canal was enlarged, the cellular density was reduced, and the neurons of the intermediolateral and ventral horns and of lamina IV were smaller.