Electrochemical measurements of DNA melting on surfaces.

Thermal denaturation, or melting, measurements are a classic technique for analysis of thermodynamics of nucleic base driven associations in solution, as well as of interactions between nucleic acids and small molecule ligands such as drugs or carcinogens. Performed on surface-immobilized DNA films, this well-established technique can help understand how energetics of surface hybridization relate to those in solution, as well as provide high-throughput platforms for screening of small molecule ligands. Here we describe methods for measuring DNA melting transitions at solid/liquid interfaces with focus on the role of immobilization chemistry, including a common "immobilization-through-self-assembly" approach that is effective at moderate temperatures, and a thermo-stable approach based on polymer-supported DNA monolayers that can be used at elevated temperatures.

Melting thermodynamics of reversible DNA/ligand complexes at interfaces.

A variety of solution methods exist for analysis of interactions between small molecule ligands and nucleic acids; however, accomplishing this task economically at the scale of hundreds to thousands of sequences remains challenging. Surface assays offer a prospective solution through array-based multiplexing, capable of mapping out the full sequence context of a DNA/ligand interaction in a single experiment. However, relative to solution assays, accurate quantification of DNA/ligand interactions in a surface format must contend with limited understanding of molecular activities and interactions at a solid-liquid interface.

[Long-term efficacy and safety of chondroitin sulphate (structum, France) in patients with coxarthrosis].

Aim: To evaluate long-term therapeutic effect and safety of structum in patients with manifest coxarthrosis.

Material And Methods: Twenty patients with manifest coxarthrosis of degree I-III were given a 6 month structum course. Criteria of efficacy were Leken index, pain in the affected joints, nonsteroid anti-inflammatory drugs requirement, assessment of the efficacy by the patient and the doctor.

[Structum therapy of patients with rheumatoid arthritis].

Aim: To study efficacy of the chondroprotector chondroitin sulphate (structum, Pier Fabr Medicament Production, France) in patients with rheumatoid arthritis (RA) and secondary osteoarthrosis of the knee joints.

Material And Methods: 15 women with a long history of RA (mean duration 11.9 years) entered an open non-randomized trial of structum.

Mitochondrial adaptations in skeletal muscle cells in mammals exposed to gravitational unloading.

It is known that exposure to actual or simulated weightlessness is often accompanied by decreased muscle dynamic performance, and increased level of blood lactate accumulation. Decreased mitochondrial content found in fibers of the working muscles is considered to be one of the possible causes for those changes. Studies on oxidative potential of the muscle cell (i.

Effects of Ca2+(-)binding agent on unloaded rat soleus: muscle morphology and sarcomeric titin content.

It had been hypothesized and recently shown that the exposure to gravitational unloading brought out to sufficient accumulation of Ca2+ in the myoplasm of soleus muscle fibers. Some authors believe that this dramatic Ca2+ accumulation induces the muscle protein degradation (including cytoskeletal proteins) by means of Ca 2(+)-activated proteases. For instance, the loss of giant sarcomeric cytoskeletal protein titin which is believed to determine the elasticity properties of muscle fibers, may contribute to the fiber stiffness decrease under unloading conditions.

Structural and metabolic characteristics of human soleus fibers after long duration spaceflight.

The fiber size decline, alterations in fiber metabolic potential and increase of connective tissue component were shown in human m. vastus lateralis after short and long-duration space flights and in m.soleus and m.

Characteristic of changes in the structure and metabolism of the vastus lateralis muscles in monkeys after space flight.

Monkeys subjected to space flight were found to have significant decreases in the sizes of slow and rapid fibers in the vastus lateralis muscle, due not only to weightlessness but also, to some extent, to restriction of movement activity within the capsule. The quantity of total protein in muscle fibers did not decrease. The respiratory peak in the pool of vastus lateralis muscle fibers decreased after space flight, as did the activity of oxidative enzymes (particularly in rapid fibers of the vastus lateralis muscle).

Effects of weightlessness and movement restriction on the structure and metabolism of the soleus muscle in monkeys after space flight.

After humans and animals have been in conditions of real and modeled weightlessness, the most marked changes are seen in the "slow" tonic muscles, particularly soleus. Studies of the effects of weightlessness and movement restriction on the soleus muscle in monkeys demonstrated significant reductions in the sizes of slow and rapid fibers due mainly to the actions of real weightlessness (rather than movement restriction in the space capsule). Protein loss in soleus muscle fibers in monkeys following space flight was more marked than loss of other components, including water.

Influence of repetitive Gz acceleration on structural and metabolic profile of m. vastus lateralis in monkeys exposed to 30 day bedrest.

It was shown that changes in structural and metabolic indices of extensor muscles of the lower extremities were usually found in man after exposure to space flight or to bed rest. Similar changes were also observed in monkeys, space-flown on "Kosmos" biosatellites. Response to weightlessness and to restraint was found to be different in m.

Dystrophin in limb skeletal muscle fibers and creatinkinase leakage after acute +3 Gz acceleration in rhesus monkeys.

Intensive muscle tension induces significant blood accumulation of enzymes and structural proteins of the muscle origin. Altered macromolecular permeability of the sarcolemma is attributed to integrity of sarcolemmal cytoskeleton, mainly to dystrophin-sarcoglycan (DSG) complex. It is known that intensive tension of the antigravity extensor muscles is observed under conditions of gravitational overloading.

Morphology changes in rat skeletal muscles after 19 day exposure to +2 G.

Effects of long duration hypergravity on m. soleus morphology characteristics are still unknown. Particularly, only one paper describes the size and myosin heavy chain profiles of rat hindlimb extensor muscle fibers after 2 weeks of +2 G exposure.

Effects of long-duration bed rest on structural compartments of m. soleus in man.

Magnetic resonance imaging (MRI), histomorphometry and electron microscopy of muscle demonstrate that long-term exposure to actual or simulated weightlessness (including head down bed rest) leads to decreased volume of antigravity muscles in mammals. In muscles interbundle space is occupied by the connective tissue. Rat studies show that hindlimb unloading induces muscle fiber atrophy along with increase in muscle non-fiber connective tissue compartment.

[Changes in structure and metabolism in the m. vastus lateralis in monkeys after a space flight].

Monkeys developed a significant reduction in size of the m. vastus lateralis' fast and slow fibres, the amount of protein in them remaining the same.

[Effect of weightlessness and movement restraint on structure and metabolism of M. soleus in monkeys after space flight].

After staying in real and simulated weightlessness, the most obvious changes were recorded in the "slow" tonic muscles like m. soleus, the protein loss in the fibres being greater than the loss of other components, water included.

[Structural and metabolic characteristics of m. vastus lateralis of monkeys during 30-day hypokinesia: effects of prophylactic Gz-accelerations].

Studies of m. vastus lateralis in Rhesus monkeys exposed to weightlessness on board of the Russian biosatellites showed the profound changes of the muscle structural and metabolic profile. It is known that exposure to head-down tilt berets (BR) induces the similar changes though not so pronounced.

Structural and metabolic profile of rhesus monkey m. vastus lateralis after spaceflight.

The effect of microgravity on slow- and fast-twitch fibers of m. vastus lateralis of rhesus monkeys was investigated. After real flight, fibers of both types were reduced in size, whereas after simulated flight, only type I fibers tended to diminish.

Structural and metabolic characteristics of rhesus monkey m. soleus after spaceflight.

The effect of microgravity and diminished motor activity on m. soleus fibers of rhesus monkeys was investigated. A significant size reduction of both slow- and fast-twitch fibers was found in the flight animals only.

Time-course of human muscle fibre size reduction during head-down tilt bedrest.

The first studies of space flown rats revealed that in m.soleus (SOL) slow-twitch fibers (ST) were reduced in size more pronouncedly than fast-twitch fibers (FT). The same differences in the fiber atrophy levels were found in rats after hind-limb suspension.

[Dynamics of human muscle fibers atrophy during long-term head-down hypokinesia].

The dynamics of atrophy in the muscles-extensors of the leg and thigh during long-term hypokinesia was studied with the model of head-down tilt (HDT -6 degrees) in a series of two experiments (120 and 60 days in duration) with participation of men and women. Dynamics of the cross-sectional area of human muscular fibers was characterized by similar atrophy of the fast and slow fibers on the first stage of HDT. Later on, the size of fast fibers in m.

[Tuberculin-dependent and nonspecific migration activity of leukocytes in astronauts].

There have been presented the results of studying the reactivity of leucocytes with respect to tuberculin and monspecific migration activity of leukocytes in the cosmonatus pre flight and after completion of orbital expeditions of various duration are presented. In some cosmonauts tuberculin rearranged migration of leukocytes. This may bear witness to activisation of the immunity system in response to the antigens which had been already familiar to test-subjects.