Eccentric exercise in ischemic cardiac patients and functional capacity: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Eccentric (ECC) exercise is an "economical" type of exercise with low energy requirements and does not cause early fatigue. Therefore, it is used for cardiac patients, who have low physical activity and exercise intolerance, as an easier kind of training. OBJECTIVE: This systematic review aimed to investigate the efficacy of ECC exercise for functional capacity (FC) in patients with ischemic heart disease. DESIGN: Systematic review. METHODS: MEDLINE via PubMed and EBSCO databases were searched for articles of randomized controlled trials of adults with ischemic heart disease who underwent ECC training as compared with other forms of exercise (concentric exercise) or no exercise and assessed FC. The methodologic quality of studies was assessed by the PEDro scale. A meta-analysis was performed with sufficient homogeneity between at least 2 studies in the pre-defined comparisons. RESULTS: Four studies, investigating a total of 99 subjects, met the inclusion criteria. The results of the studies did not clearly indicate whether ECC exercise could improve FC better than traditional forms of exercise. However, the small number of studies and their methodologic weaknesses do not allow for drawing firm conclusions. CONCLUSIONS: We found contradictory results about the effectiveness of ECC as compared with concentric exercise in terms of FC in ischemic cardiac patients. Further investigation with well-designed randomized trials is needed to determine the effectiveness of this kind of exercise for FC in such patients.

First observation of the unbound nucleus 15Ne.

We report on the first observation of the unbound proton-rich nucleus 15Ne. Its ground state and first excited state were populated in two-neutron knockout reactions from a beam of 500 MeV/u 17Ne. The 15Ne ground state is found to be unbound by 2.522(66) MeV. The decay proceeds directly to 13O with simultaneous two-proton emission. No evidence for sequential decay via the energetically allowed 2- and 1- states in 14F is observed. The 15Ne ground state is shown to have a strong configuration with two protons in the (sd) shell around 13O with a 63(5)% (1s1/2)2 component.

Test-retest reliability of grip strength measurement in full elbow extension to evaluate maximum grip strength.

The objective of this study was to investigate the test-retest reliability of measurement of grip strength in full elbow extension. The grip strengths of 19 healthy participants were measured using the Jamar dynamometer by the same rater on two occasions with an interval of 7 days between measures. Test-retest reliability of grip strength measurement was excellent in full elbow extension and associated with low values of standard error of measurement and small variations in the differences between the two measurements in both testing sessions.

Nuclear (DNA, RNA, histone and non-histone protein) and nucleolar changes during growth and senescence of may apple leaves.

Quantitative interference microscopy was used to determine changes in nuclear and nucleolar indices (dry mass and cross-sectional area) in upper and lower epidermal cells and adjacent leaf-margin hair cells of the May apple (Podophyllum peltatum L.) leaves over a 42-day period (after leaves emerged above the ground litter). These indices decreased in a highly correlated manner. A ploidy variation may exist between epidermal cells and leaf-margin hair cells. Using the leaf-margin hair cells model, six nuclear macromolecule indices (total nucleic acid, DNA, RNA, total nuclear protein, histone and non-histone protein), nuclear volume, nucleolar volume and perinucleolar volume (measured using quantitative epifluorescence-phase contrast microscopy) all declined with age (42-day study) in a highly correlated manner. The degeneration of the nucleus and nucleolus in the three leaf locations studied followed the patterns observed for programmed cellular senescence and death (necrosis) in epidermal cells of onion leaf bases (stored tissue; leaf bases did not contain chlorophyll) and human epithelial cells (buccal; cervical). We conclude that the epidermal cells and leaf-margin hair cells from green leaves of the May Apple are ideal for the study of programmed cell senescence and death in plants, especially for the partitioning of this process into the study of: the point-of-no-return (solubilization of the karyoskeleton and loss of non-histone proteins and RNA associated with the karyoskeleton from the nucleus); nuclear pycnosis (loss of nuclear dry mass and volume and loss of nuclear internal support structure); chromatin condensation, margination along the inner nuclear envelope; and DNA-histone degeneration; degeneration of the nucleolus and loss of the perinucleolar zone of exclusion. The characterization of chlorenchyma cells during the 42-day period should now be undertaken (leaf senescence as indicated by the beginning of yellowing about 35 days after emergence) to determine whether these cells with functional chloroplasts undergo nuclear changes like those lacking functional chloroplasts.

Nuclear degeneration in epidermal cells of drying onion bulb leaf bases.

We tested the null hypothesis 'that activated nuclei and nucleoli in outer-epidermal cells of newly exposed equatorial tissue of the turgid leaf bases of white onions (exposed to the ambient atmosphere by removal of two dry and two turgid leaf bases) remained in that state as the tissue dried' by following nuclear macromolecules (total nucleic acid, DNA, RNA, total protein, histone, and non-histone protein; compared with T0 = 100%) and nucleolar morphologies over a 5-day period. The nuclei became activated within 6 h and remained in that state for 2-3 days [increases in RNA, non-histone protein, and volume of major nucleoli occurred by T12 (about 191, 177, and 289%, respectively) and appearance of the minor nucleoli between T12 and T24 (activation of silent rRNA cistrons)]. Combined nucleolar (major and minor) volumes decreased to 228% by T24 and to 150% by T48. Minor nucleoli were visible at T24 and T48. DNA (DAPI) remained unchanged over that period of time. At the T96 sampling, all nuclear indices had decreased to levels below those obtained at the time of exposure to the ambient atmosphere; minor rRNA cistrons had became silent genes; nuclear volume was about 89% of the original volume; and, nucleolar volume (major nucleoli) was about 93%. The percentages for nuclear indices at T120 were DNA, 85% of T0; RNA, 35%; histone, 87%; non-histone protein, 47%; nuclear volume, 81%; and nucleolar volume, 67%. Of interest is the lack of change in major nucleolar morphologies between T96 and T120 although they decreased in volume during that period. We infer that the karyoskeleton (nuclear matrix) had undergone irreversible degeneration after T48 and that the cells had passed the point-of-no-return in the senescence pathway by T120. We propose that this model for cell senescence and death (drying of turgid leaf bases to form the dry, dead outer covering of the bulbs) simulates post-harvest storage conditions and will prove helpful to those studying cellular senescence mechanisms and associated host-pathogen interactions in plants.

Brassinolide is a selective ribosomal cistron regulator in onion leaf base tissue.

Outer epidermal cells from the basal, equatorial, near-apical, and apical regions of the third turgid onion (Allium cepa L. var. yellow, sweet Spanish) leaf base were treated (3 and 6 h in the dark = T3 and T6, respectively) with brassinolide (Br, a brassinosteroid plant growth regulator; effects on excised pieces compared with those in water controls: there were no statistical differences between the T3 and T6 results). Br induced increases in the volume and changes in morphologies of the major nucleoli to a greater extent than observed for major nucleoli in basal through near-apical controls. No major nucleoli were activated in control or Br-treated apical tissue. Minor nucleolar organizer regions in control and Br-treated tissue remained inactive in all locations. We propose that Br is a major ribosomal cistron regulator.

Effect of abscisic acid, gibberellic acid, indoleacetic acid, and kinetin on selective ribosomal cistron regulation in quiescent and senescent onion leaf base tissue.

Small pieces of tissue from the basal, equatorial, near-apical, and apical regions of the third turgid onion leaf base were treated (3 and 6 h in the dark) with abscisic acid (ABA), gibberellic acid (GA3), indoleacetic acid (IAA), and kinetin (K) and compared with responses in water controls. ABA inhibited the activation (increase in size and changes in morphologies from round or oval to elongated-oval and dumbbell) of major nucleolar organizer regions (NORs) in basal, equatorial, and near-apical tissue. GA3 and K activated the major NORs in the basal, equatorial, and near-apical tissue. IAA stimulated the activation of major NORs in basal tissue but inhibited their activation in equatorial and near-apical tissue. No major nucleoli were activated in control or plant growth regulator-treated apical tissue. Minor NORs were not expressed in the control and plant growth regulator-treated tissue in these four locations. Actinomycin D and cycloheximide inhibited major NOR activation in equatorial control and kinetin-treated tissue. We propose that ABA, GA3, IAA, and K are major NOR regulators. We infer that the basal through near-apical cells were quiescent during post-harvest storage and that the cells in the apical tissue had senesced beyond the point of no return (degeneration of the karyoskeleton) in the cellular senescence pathway.

Effect of ethylene on selective ribosomal cistron regulation in quiescent and senescent onion leaf base tissue.

Excised pieces of tissue from four regions (base, equator, near-apex, and apex) of yellow, sweet Spanish onion bulbs were treated with ethylene in an attempt to activate minor nucleolar organizer regions (NORs). In the quiescent equatorial and near-apical regions, major nucleoli in control and ethylene-treated tissue increased in size and changed morphologies. The minor NORs were expressed only in the ethylene-treated tissue. These data confirm and extend our previous findings. In the quiescent basal region, major nucleoli increased in size and changed morphology from round to oval, elongated-oval and dumbbell shapes in both control and ethylene-treated tissue. However, the number of elongated-oval and dumbbell types were one-third that observed in equatorial and near-apical tissue. Minor NORs were not expressed. We infer that the responses of the major nucleoli and the inability to activate minor NORs were due to hormone interactions that affect the expression of rRNA cistrons (methylation-demethylation of CpG sites in the external spacers) in this basal (meristematic) region. In the senescing apical region, major nucleoli in control and ethylene-treated tissue did not change in size or morphology and ethylene had no effect on minor NORs. We infer that the cells in the apical region had passed the point of no return in the senescence pathway. We propose that the inability to activate major and minor NORs in senescing tissue is one of the earliest symptoms of cellular senescence and is associated with karyoskeleton degeneration.

Changes in nuclear macromolecules and nucleolar volume associated with selective ribosomal cistron activation by ethylene.

Pieces of leaf base tissue from the equatorial region of the third turgid onion (Allium cepa L.; yellow, sweet Spanish, quiescent tissue) leaf base with two visible major nucleoli (volume = 0.51 microns3) and two inactive minor nucleolar organizer regions (NORs) in the outer epidermal cells were placed in shallow water (time = T0 control). After 3 h (T3 control), the two visible nucleoli enlarged (178% of T0) and changed shape (from 88% round and 12% oval at T0 to 5% round, 68% oval, 20% elongated-oval, and 7% dumbbell). The minor NORs remained inactive. Nuclear RNA and non-histone protein (nHP) increased (RNA = 128% and nHP = 134%, compared with T0 data, set at 100%). The content of DNA and histone protein (H) in nuclei remained unchanged. Major nucleoli in pieces of onion placed in 10(-5) M ethylene enlarged and minor nucleoli became visible in 33% of the nuclei; i.e., ethylene acted as a selective ribosomal cistron regulator. The nucleolar volume (212% of T0) was statistically greater than those for T0 and T3. DNA and H remained unchanged (not statistically different) but RNA (159% of T0) and nHP (169% of T0) were greater (statistically significant) than those for T0 and T3 controls. Cobalt chloride (10(-5) M Co) alone or in 10(-5) M ethylene (Co + E) inhibited the enlargement of some of the major nucleoli and completely inhibited the appearance of minor nucleoli. The nucleolar volumes for the cobalt and for cobalt-ethylene treatments were significantly less than those for T3 controls and ethylene treatment at T3. DNA and histone did not change.(ABSTRACT TRUNCATED AT 250 WORDS)

Ethylene is a selective ribosomal cistron regulator in Allium cepa epidermal cells.

In Allium cepa L. (onion) the number, size, and morphology of visible nucleoli per nucleus varies during cell division, growth, differentiation, storage, activation of quiescent tissue, senescence, wounding, and disease (host-pathogen interactions). Since there are two types (differentiated visually by size) of ribosomal cistrons in onion (major and minor nucleoli differ in the external spacer nucleotide sequences), we inferred that they function separately. In controls, major nucleolar organizer regions (NORs) were visible in epidermal cell nuclei as nucleoli. After exposure of the tissue to ambient conditions, these nucleoli enlarged and changed morphology. Minor NORs (when in the genome) required more than 6 h to become developed as visible nucleoli. In the ethylene treatments, the major NORs (visible nucleoli in quiescent epidermal cells) increased in size a (activation of a greater number of tandem rRNA genes) as in the controls. The minor, quiescent NORs became active and visible (activation of quiescent, inactive NORs) within 3 h. Actinomycin D, and cycloheximide, with or without ethylene, inhibited the increase in size of the major NORs, and prevented activation of the minor NORs (i.e. they did not become visible). Silver nitrate and cobalt chloride had no effect on major NORs but inhibited the appearance of minor nucleoli when combined with ethylene treatments. We infer: ethylene acts to regulate the expression of the minor NORs (selective ribosomal cistron regulation); and, other hormone(s) are involved in the regulation of the major NORs. Yellow and white sweet Spanish onions we studied had two major NORs and two minor NORs. Red sweet Spanish onions we studied had only the two major NORs.

Effect of leu-(Asp, Asn, Glu, Gln) dipeptides on platelet aggregation in vitro.

A series of Leu-(Asp, Asn, Glu, Gln) dipeptides were synthesized and tested for their effect on human platelet aggregation in vitro induced by collagen, ADP, or adrenaline. It was found that only Leu-Asp-NH2 and Leu-Asn-NH2 inhibit rather strongly platelet aggregation, whereas a small inhibition was observed with Leu-Glu-NH2 and Leu-Gln-NH2, respectively.