Mental imagery combined with physical practice of approach shots for golf beginners.

Recent research on motor skills of golf have pointed to the usefulness of mental imagery. In golf, such training is rarely used as a teaching technique for beginners on the grounds that only top professionals stand to gain from mental imagery. This study tested whether mental imagery combined with physical practice can improve golf performance for the approach shot. 23 volunteer beginners, 8 women and 15 men, M age 23.4 yr. (SD = 3.7), enrolled in the University Physical and Sporting Activities Department, were divided into three groups, using a combination of physical practice of the approach shot plus mental imagery, physical practice only, and a third group engaging in various sporting activities instead of either mental or physical practice of the chip shot. Analysis showed that the beginners' approach shot performance improved most in the group combining physical practice and mental imagery when compared with the group just physically practising the approach shot. It seems mental training can be used effectively to improve performance even with beginners.

Caspase cleavage of the nuclear autoantigen LEDGF/p75 abrogates its pro-survival function: implications for autoimmunity in atopic disorders.

Lens epithelium-derived growth factor p75 (LEDGF/p75) is a nuclear autoantigen in atopic disorders implicated in cellular protection against stress-induced apoptosis. We observed that LEDGF/p75 was cleaved during apoptosis into fragments of 65 and 58 kD generated by caspases-3 and -7 cleaving at three sites: DEVPD30/G, DAQD486/G and WEID85/N. Sequence analysis revealed that the DEVPD30/G and WEID85/N sites lie within the highly conserved HATH (homologous to amino terminus of hepatoma-derived growth factor) region, also known as PWWP domain. Alignment of proteins containing this domain failed to reveal conservation of the DEVPD30/G and WEID85/N sites, suggesting that the HATH/PWWP domain of LEDGF/p75 may be specifically targeted by caspases. Overexpression of LEDGF/p75 protected HepG2 cells from serum starvation-induced cell death, whereas expression of the 65 kD fragment failed to protect. The apoptotic cleavage of LEDGF/p75 may contribute to the pathogenesis of atopic disorders by abrogating its pro-survival function and enhancing its immunogenicity.

Stability, reactivity, solution, and solid-state structure of halomethylzinc alkoxides.

In this paper, we report our findings regarding the development of a Lewis acid-catalyzed cyclopropanation of allylic alcohols with bis(iodomethyl)zinc. Iodomethylzinc alkoxides can be formed by treatment of an alcohol with bis(iodomethyl)zinc. These species are not prone to undergo cyclopropanation at low temperature but the addition of a Lewis acid in catalytic amounts induces the cyclopropanation reaction. Using this procedure, we demonstrated that the Lewis acid-catalyzed pathway significantly overwhelms the uncatalyzed one. This paper describes fundamental issues regarding the preparation and stability of halomethyl zinc alkoxides in solution as well as their aggregation state in solution and solid-state structures. Furthermore, the competition reaction between the inter- vs intramolecular cyclopropanation will be studied. Finally, we will discuss the possible activation pathways to explain the Lewis acid activation of halomethylzinc alkoxides. These findings provided new insights on the reactivity of ROZnCH(2)I and established the groundwork for the elaboration of an enantioselective version of the reaction.

Catalytic asymmetric cyclopropanation of allylic alcohols with titanium-TADDOLate: scope of the cyclopropanation reaction.

A substoichiometric amount of titanium-TADDOLate complex was effective at catalyzing the cyclopropanation reaction of allylic alcohols in the presence 1 equiv of bis(iodomethyl)zinc. After initial optimization of the catalyst structure, excellent yields and enantiomeric ratios were obtained for 3-aryl- or 3-heteroaryl-substituted allylic alcohols (up to 97:3). Alkyl-substituted allylic alcohols gave modest yields and enantiomeric ratios (up to 87:13) but these compare favorably with those observed with other substoichiometric chiral ligands. The full synthetic scope of the reaction is presented in this paper.

Secondary necrosis is a source of proteolytically modified forms of specific intracellular autoantigens: implications for systemic autoimmunity.

OBJECTIVE: Specific autoantigens targeted in systemic autoimmunity undergo posttranslational modifications, such as cleavage, during cell death that could potentially enhance their immunogenicity. In light of the increasing interest in the immunologic consequences of defective clearance of apoptotic cells, we sought to determine whether autoantigens cleaved during apoptosis undergo an additional wave of proteolysis as apoptosis progresses to secondary necrosis in the absence of phagocytosis. METHODS: Apoptosis was induced in Jurkat cells with etoposide, anti-Fas antibody, or staurosporine (STS), and in HeLa cells with STS. Progression to secondary necrosis was assessed morphologically and quantified by trypan blue uptake. Autoantigen proteolysis during cell death was examined by immunoblotting of cell lysates using highly specific human autoantibodies as detecting probes. RESULTS: Cells treated with the different apoptosis inducers underwent a rapid apoptosis that gradually progressed to secondary necrosis. During the initial apoptotic stages, several autoantigens, including poly(ADP-ribose) polymerase, topoisomerase I (or Scl-70), SSB/La, and U1-70 kd, were cleaved into their signature apoptotic fragments. Progression of apoptosis to secondary necrosis was associated with additional proteolysis of these and other autoantigens in a caspase-independent manner. Some autoantigens (e.g., ribosomal RNP, Ku, and SSA/Ro) appeared to be resistant to proteolysis during cell death. CONCLUSION: In the absence of phagocytosis, apoptotic cells may undergo secondary necrosis, a process associated with additional proteolytic degradation of specific autoantigens. Secondary necrosis may occur in vivo in autoimmune disorders associated with impaired clearance of apoptotic cells and serve as a source of modified forms of specific autoantigens that might stimulate autoantibody responses under proinflammatory conditions.

Imagery quality estimated by autonomic response is correlated to sporting performance enhancement.

It is now well established that mental imagery practice improves motor skills, but performance efficiency depends on many factors: the main one being individual differences. The aim of this study is to evaluate performance improvement with imagery quality estimated during ANS recording. Volleyball training ("receiving serve") afforded us the experimental paradigm. Subjects were required to pass an opponent's serve to a given team mate. The receiver's performance was evaluated from the accuracy of his pass to the targeted team mate. From these first test results, subjects were divided into two equivalent groups: imagers and controls. After mental practice the two groups were submitted to a posttest similar to the first one. During the pretest, posttest actual practice as well as the last session of corresponding mental rehearsal, six autonomic parameters were continuously recorded. Furthermore, and for the first time, a grade obtained from four different aspects of this response permits qualitative evaluation of each subject's mental imagery. This estimation, based on the well-established link between performance and autonomic response, is validated by the fact that good correlation was obtained between this grade and the performance improvement of each of the "imager" group subjects.

Autonomic nervous system responses correlate with mental rehearsal in volleyball training.

The aim of this study was to assess objectively the processes of mental rehearsing (imagery) by measuring variations of the autonomic nervous system (or ANS responses) during an open-ended complex motor skill in two actual experiments (volleyball) and during mental rehearsing taking place between them. Comparison between pre- and post-test (volleyball) scores related to imagining and non-imagining performances revealed significant improvement in the former (chi2 = 20.9, P < 0.00001) while in the latter chi2 = 27, P < 0.9, NS. The ANS parameters (skin potential and resistance, skin temperature and heat clearance, instantaneous heart rate and respiratory frequency) were quantified by original techniques and indices. Results from a principal component analysis showed a strong correlation between the responses in actual tasks (pre- and post-test volleyball) and during mental imagery, since the same preferential variables appeared on the main axis in 87% of cases. Thus the same autonomic channels seemed to be used during the actual activity and during the mental imagery of this activity. So far as phasic results were concerned, the main finding was a differing development of skill between imagining and non-imagining volleyball players. No clear difference was seen between pre- and post-tests in non-imaginers, except an increase in the median of the duration of the response observed in heat clearance, m1 and m2 respectively [m1 = 5.8 (SD 4.1) s, m2 = 7.6 (SD 3.9) s, P < 0.001]. Conversely, for other ANS parameters, a significant decrease was seen in the post-test responses compared to pre-test responses in the imagining group [for instance, the median of the duration of the resistance responses decreased from m1 = 12.6 (SD 4.3) s, and m2 = 7.8 (SD 4.5) s, P < 0.0001 in imaginers, while no change was observed in non-imaginers: 9.6 (SD 6.0) s vs 9.5 (SD 6.1) s, NS] except in the duration of the heat clearance response where an increase was seen [m1 = 7.3 (SD 5.0) s vs m2 = 7.6 (SD 3.1) s, NS]. Compared to the non-imagining group, the latter result may also have been associated with a response decrease in the imagining group. Thus mental rehearsing induced a specific pattern of autonomic response: decreased amplitude, shorter duration and negative skin potentials compared to the control group. As this pattern was associated with better performance in the tests it can be suggested that in the case of open-ended motor activity, mental rehearsing may help in the construction of schema which can be reproduced, without thinking, in actual practice. Thus a neural information process might develop in the central nervous system changing from a parallel into a serial treatment.

Stimulation of mitotic recombination upon transcription from the yeast GAL1 promoter but not from other RNA polymerase I, II and III promoters.

Homologous recombination in Saccharomyces cerevisiae and other organisms can be stimulated by transcription. Consistent with this, we find that recombination of a chromosomal ade1 allele with a plasmid-borne ADE1 ORF under the control of the GAL1 promoter increased from 6.1x10(-6) to 1.7x10(-4) when transcription of the plasmid locus was induced by growing the cells in the presence of galactose. Recombination could also be stimulated by over-expressing the Gal4 transcription factor in the presence of the GAL1-ADE1 plasmid, while culturing the cells in dextrose medium. However, when transcription of the same ORF was driven from the highly active promoters of the rDNA (RNA polymerase I), and ADH1 (RNA polymerase II) genes, only background levels of recombination (5-10x10(-6)) were observed, irrespective of the carbon source. Recombination was found to involve integration of the whole plasmid and to depend on RAD51, RAD52 and RAD54. The results indicate that increased accessibility of transcriptionally active chromatin is not sufficient to cause increased rates of this kind of reciprocal exchange.

Increased activation as a limiting factor of performance in sharp shooters.

The measurement of autonomic nervous system (ANS) activity was performed on 10 male and five female sharp shooters (rifle) during competitions. Electrodermal, thermovascular, cardiorespiratory variables and two indices of performance were recorded simultaneously. When the subjects fired shots that hit the target, they had a higher number of negative skin potential responses than when they missed. The responses had lower amplitude but lasted longer than when the shots missed the target. Good performance seemed to depend on high levels of motivation (increase in negative potential response), better mastery of the emotional reactivity (low amplitude response), and greater concentration time (increased duration of response).

Autonomic responses correlate to motor anticipation.

New findings have stated that autonomic nervous system (ANS) functioning may reflect some cognitive processes observed in real time analysis. Four ANS variables plus instantaneous heart rate and respiratory frequency were quantified by original techniques and indices on 11 subjects during a coincidence-anticipation task, performed on a computer screen under six different, randomly-presented modalities (3 modalities describing the spot moving along a parabola at 2 speeds). Tonic levels and phasic responses corresponding to each trial were recorded continuously. Results showed that skin resistance tonic level evolution gave evidence of vigilance changes. Thus, performance can be related to subjects' vigilance. An autonomic response was always observed during performance of an anticipation task. The six task modalities were distinguished by performance values. Simultaneously recorded ANS responses fully differentiated these same modalities for 10 subjects out of 11. These ANS responses were furthermore related to performance. Ten subjects out of 11 possess at least one Autonomic variable which can differentiate the six task modalities, confirming Lacey's hypothesis on ANS preferential response, and suggesting ANS specificity. ANS functioning may reveal some brain functions through a specific autonomic channel, characterizing each subject. The behavioral output of an individual may thus be reflected by such a functioning.

Autonomic nervous system response patterns correlate with mental imagery.

New findings related to autonomic nervous system (ANS) functions may reveal some brain functions, since they can be observed by real time analysis. ANS parameters (skin potential and resistance, skin temperature and blood flow, instantaneous heart rate) and instantaneous respiratory frequency are quantified by original techniques and indices. Results show that ANS responses correlate with mental imagery. Imagery contents influence autonomic responses, thus making it comparable to real activity. Therefore, by using two shooting events as models, the almost identical nature of the ANS response is evidenced during real shooting and in mental concentration before shooting. Next, shooting activity imagery can be distinguished from neutral imagery but is comparable to the activity itself as far as ANS responses are concerned.

Relationship between mental imagery and sporting performance.

Simultaneous measurement of six autonomic nervous system (ANS) variable responses during mental rehearsal of an action, makes it possible to draw a parallel between mental imagery of a task and its actual execution. The experiment was carried out in the field during precision shooting competitions and in the laboratory for imagery activity, on 22 subjects. Results show that there is similarity of ANS response in the three situations: the period of concentration prior to shooting, actual shooting and mental representation of shooting. The ratio formed by ANS response during concentration and imagery of actual firing tends towards the value one, therefore towards some identity. All subjects may be classified around this value; it is worth noting that subject distribution around this value corresponds to performance value. It seems that the better the subject, the closer his concentration/shooting or imagery/actual shooting ratio is to the theoretical value one. These results show the utmost importance of the quality of mental representation for performance improvement. It can be supposed that subject classification above the theoretical value one corresponds to overflowing emotional reactivity in one of the two phases and that this interferes with accuracy; a placing below the theoretical value one shows a lack of similarity between mental representation and the action.

Results from six autonomic nervous system responses confirm "autonomic response specificity" hypothesis.

The Autonomic Nervous System (ANS) specificity concept corresponds, according to Lacey, to the preferential reaction on the part of the same subject along a determined ANS channel. Six channels: skin potential, resistance, blood flow, temperature, and instantaneous heart and respiratory frequencies were recorded simultaneously in 33 subjects submitted to a verbal association test likely to arouse different kinds of emotions, and to mental arithmetic. Studies of these six parameters in relation to mean response, and principal component analysis made it possible to bring the individual response to the fore via ANS preferential channels, and thus to confirm Lacey's hypothesis, while adding further evidence as corollaries.

Two monoclonal antibodies to two different epitopes of human growth hormone form a precipitin line when counterdiffused as soluble immune complexes.

We have tested whether soluble immune complexes obtained by mixing human growth hormone (hGH) with one anti-hGH monoclonal antibody (MAb) can form a precipitin line when diffused against another MAb in a polyethylene glycol containing gel. By testing seven anti-hGH MAbs one against the other in this assay, we have found that 10 pairs of MAbs out of the 21 possible combinations formed a line. Apparently, the first MAb formed soluble hGH dimers that were linked by the second MAb into precipitating linear complexes. Since each precipitin line was formed by the cooperative reaction of two MAbs, this sequential reaction of MAbs may be used in methods for the positive selection of MAbs that are suitable for two-site immunoassays.

Production and characterization of monoclonal antibody to gentamicin.

Splenocytes from BALB/c mice immunized with a gentamicin-hemocyanin conjugate were fused with X63-Ag8.653 murine myeloma cells to produce hybridomas that secreted monoclonal antibody to gentamicin. Sixteen positive clones were obtained. The monoclonal antibody chosen for a gentamicin immunoassay has been characterized with respect to class, subclass, type of light chain, electrophoretic homogeneity, and binding affinity. Gentamicin monoclonal antibody purified from mouse ascites fluid was analyzed by immunoelectrophoresis, double immunodiffusion, enzyme-linked immunosorbent assay (ELISA), and polyacrylamide gel electrophoresis (PAGE). The results show that the antibody is an IgG2a (kappa). Two bands were detected when the purified antibody was electrophoresed on polyacrylamide gels: a major band and a less mobile minor component (5.6% of the major band). Both were IgG2a (kappa). The major band contained antibody which bound 2.1 moles of the substrate-labeled gentamicin derivative, beta-galactosyl-umbelliferone sisomicin, per mole of IgG, whereas one mole of the minor band bound only 0.095 moles of the substrate-labeled conjugate. The antibody has an affinity constant of 1.22 X 10(10) M-1.

Identifying immunoglobulin isotypes, allotypes and idiotypes by a hemolytic assay in gel.

We developed a hemolytic radial immunodiffusion assay for identifying immunoglobulin (Ig) isotypes, allotypes and idiotypes by using gels containing erythrocytes coated with anti-Ig antibody or erythrocytes coated with Staphylococcal protein A. These indicator cells lysed specifically when treated sequentially with Ig antigen, the appropriate anti-Ig antiserum (developer) and complement. To identify these Ig subpopulations, we used monospecific indicator cells, e.g. erythrocytes coated with antibody specific for an Ig isotype, and developers with broader specificities ('multispecific'), e.g. antiserum to Fab. Alternatively, we used 'multispecific' indicator cells, e.g. erythrocytes coated with antibody to Fab and monospecific developers, e.g. antiserum to Ig idiotype. To identify Ig subpopulations specifically, either the indicator cells or the developer need to be monospecific. When both the indicator cells and the developer were monospecific, e.g. to allotype and to isotype, the specificity was determined by both reagents and ultimately restricted by the reagent with the narrower specificity, that is, reacting with the smallest Ig subpopulation. This sensitive hemolytic assay may be used to quantitate subpopulations of Ig molecules and may be modified into a reverse plaque forming cell assay to count lymphocytes secreting a given Ig class, type, allotype and idiotype.