Effects of whole body vibration on strength and jumping performance in volleyball and beach volleyball players.

The primary aim of this study was to examine the effects of 6-week strength training with whole body vibration (WBV) on leg strength and jumping performance in volleyball and beach volleyball players. Twenty-three sub-elite male volleyball (VB; n=12) and beach volleyball players (BVB; n=11) aged 21.2±3.0 years were divided into two groups and subjected to 6 weeks of strength training (three one-hour sessions per week): (I) 12 players (6 VB and 6 BVB players) underwent training with WBV (30-40 Hz, 1.7-2.5 mm, 3.0-5.7 g), and (II) 11 players (6 VB and 5 BVB players) underwent traditional strength training. Squat jump (SJ) and countermovement squat jump (CMJ) measurements by the Ergo Tester contact platform and maximum leg press test (1RM) were conducted. Three-factor (2 time x 2 WBV use x 2 discipline) analysis of variance for SJ, CMJ and 1RM revealed a significant time main effect (p<0.001), a WBV use effect (p<0.001) and a discipline effect (p<0.001). Significantly greater improvements in the SJ (p<0.001) and CMJ (p<0.001) and in 1RM (p<0.001) were found in the WBV training groups than in traditional training groups. Significant 3-way interaction effects (training, WBV use, discipline kind) were also found for SJ, CMJ and 1RM (p=0.001, p<0.001, p=0.001, respectively). It can be concluded that implementation of 6-week WBV training in routine practice in volleyball and beach volleyball players increases leg strength more and leads to greater improvement in jump performance than traditional strength training, but greater improvements can be expected in beach volleyball players than in volleyball players.

Behavioural and neurophysiological markers reveal differential sensitivity to homeostatic interactions between centrally and peripherally applied passive stimulation.

Repetitive transcranial magnetic stimulation (rTMS) is an effective tool for inducing functional plastic changes in the brain. rTMS can also potentiate the effects of other interventions such as tactile coactivation, a form of repetitive stimulation, when both are applied simultaneously. In this study, we investigated the interaction of these techniques in affecting tactile acuity and cortical excitability, measured with somatosensory evoked potentials after paired median nerve stimulation. We first applied a session of 5-Hz rTMS, followed by a session of tactile repetitive stimulation, consisting of intermittent high-frequency tactile stimulation (iHFS) to a group of 15 healthy volunteers ("rTMS + iHFS" group). In a second group ("rTMS w/o iHFS"), rTMS was applied without iHFS, with a third assessment performed after a similar wait period. In the rTMS w/o iHFS group, the 5-Hz rTMS induced an increase in cortical excitability that continued to build for at least 25 min after stimulation, with the effect on excitability after the wait period being inversely correlated to the baseline state. In the rTMS + iHFS group, the second intervention prevented the continued increase in excitability after rTMS. In contrast to the effect on cortical excitability, rTMS produced an improvement in tactile acuity that remained stable until the last assessment, independent of the presence or absence of iHFS. Our results show that these methods can interact homeostatically when used consecutively, and suggest that different measures of cortical plasticity are differentially susceptible to homeostatic interactions.

Development and validation of an indirect enzyme immunoassay for detection of ovine antibody to Brucella ovis.

An indirect enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of Brucella ovis infection was developed. The assay uses a mouse monoclonal antibody to bovine IgG1 horseradish peroxidase (HRPO) conjugate that cross-reacts with immunoglobulin from sheep and a purified antigen from Brucella ovis. The ELISA data were read and analyzed according to a targeting procedure. The ELISA results were compared with a cold complement fixation test (CFT). Sera from 675 rams from three uninfected flocks were used to determine the ELISA cut-off value (O.D. 405 nm: 0.095) and the diagnostic specificity of the ELISA (100%) and the CFT (99.69% +/- 0.42). The ELISA cut-off value was corroborated by receiver operating characteristic (ROC) analysis. Six hundred and forty semen and serum samples from 419 rams from two naturally infected flocks were collected before and after mating-time during two consecutive years. All semen samples were cultured and Brucella ovis was isolated from 28 samples. Sera from the 28 rams with positive semen were used to determine the diagnostic sensitivity of the ELISA (96.43% +/- 6.8) and of the CFT (including suspected positive samples with titers of 1:5; 88.89% +/- 11.85). Considering the CFT suspicious and the anti-complementary reactions as positive resulted in a diagnostic sensitivity value of 89.28% +/- 11.46. Six hundred and ten serum samples from the 640 sera were used to determine relative sensitivity (excluding sera with 1:5) at: ELISA/CFT 97.26% +/- 3.74 and CFT/ELISA was 71.72% +/- 8.87. The percent agreement, beyond chance measured by the Kappa index was 79.7. Relative sensitivity ELISA/CFT (including 1:5 titers in the CFT as positive) was 94.9% +/- 4.83 and CFT/ELISA was 72.84% +/- 8.59. The Kappa index was 79.4.

Rearrangements and point mutations of P450c21 genes are distinguished by five restriction endonuclease haplotypes identified by a new probing strategy in 57 families with congenital adrenal hyperplasia.

Congenital adrenal hyperplasia (CAH) is caused by disorders of the P450c21B gene, which, with the P450c21A pseudogene, lies in the HLA locus on chromosome 6. The near identity of nucleotide sequences and endonuclease cleavage sites in these A and B loci makes genetic analysis of this disease difficult. We used a genomic DNA probe that detects the P450c21 genes (A pseudogene, 3.2 kb; B gene, 3.7 kb in Taq I digests) and the 3' flanking DNA not detected with cDNA probes (A pseudogene, 2.4 kb; B gene, 2.5 kb) to examine Southern blots of genomic DNA from 68 patients and 165 unaffected family members in 57 families with CAH. Of 116 CAH-bearing chromosomes, 114 could be sorted into five easily distinguished haplotypes based on blots of DNA digested with Taq I and Bgl II. Haplotype I (76 of 116, 65.6%) was indistinguishable from normal and therefore bore very small lesions, presumably point mutations. Haplotype II (4 of 116, 3.4%) and haplotype III (8 of 116, 6.9%) had deletions and duplications of the P450c21A pseudogene but had structurally intact P450c21B genes presumably bearing point mutations; point mutation thus was the genetic defect in 88 of 116 chromosomes (75.9%). Haplotypes IV and V lack the 3.7-kb Taq I band normally associated with the P450c21B gene. Haplotype IV (13 of 116, 11.2%) retains all other bands, indicating that the P450c21B gene has undergone a gene conversion event, so that it is now also associated with a 3.2-kb band. Haplotype V (13 of 116, 11.2%) lacks the 2.4-kb Taq I fragment and the 12-kb Bgl II fragments normally associated with the P450c21A pseudogene, as well as lacking the 3.7-kb Taq I fragment, indicating deletion of approximately 30 kb of DNA, resulting in a single hybrid P450c21A/B gene. Most (114 of 116, 98%) CAH alleles thus can easily be classified with this new probing strategy, eliminating many ambiguities resulting from probing with cDNA.