Aquatic plyometric training increases vertical jump in female volleyball players

PURPOSE: Numerous studies have reported that land-based plyometrics can improve muscular strength, joint stability, and vertical jump (VJ) in athletes; however, due to the intense nature of plyometric training, the potential for acute muscle soreness or even musculoskeletal injury exists. Performance of aquatic plyometric training (APT) could lead to similar benefits, but with reduced risks due to the buoyancy of water. Unfortunately, there is little information regarding the efficacy of APT. Thus, the purpose of this study was to examine the effects of APT on VJ and muscular strength in volleyball players. METHODS: Nineteen female volleyball players (aged 15 +/- 1 yr) were randomly assigned to perform 6 wk of APT or flexibility exercises (CON) twice weekly, both in addition to traditional preseason volleyball training. Testing of leg strength was performed at baseline and after 6 wk, and VJ was measured at baseline and after 2, 4, and 6 wk. RESULTS: Similar increases in VJ were observed in both groups after 4 wk (APT = 3.1%, CON = 4.9%; both P < 0.05); however, the APT group improved by an additional 8% (P < 0.05) from week 4 to week 6, whereas there was no further improvement in the CON group (-0.9%; P = NS). After 6 wk, both groups displayed significant improvements in concentric peak torque during knee extension and flexion at 60 and 180 degrees x s(-1) (all P < 0.05). CONCLUSIONS: The combination of APT and volleyball training resulted in larger improvements in VJ than in the CON group. Thus, given the likely reduction in muscle soreness with APT versus land-based plyometrics, APT appears to be a promising training option.     

Staff nurse perceptions of the contributions of students to clinical agencies

This study is a replication and extension of Grindel and associates' 2001 study of the perceptions of staff nurses (psychiatric, perinatal, and medical/surgical) regarding the benefits of having students from a baccalaureate nursing program work in clinical agencies. Using the Nursing Students' Contributions to Clinical Agencies tool, the overall perception of students' contributions ranged from -4 to +5, with a mean of 2.50. The two highest ranked items were "allows opportunities for mentoring" and "threatens professional role development," indicating the ambivalence staff nurses feel toward nursing students. Qualitative data also demonstrated the benefits and challenges of working with students. Recommendations are made for the creation of a positive, nurturing learning environment through closer collaboration between nursing education and service.     

Tai Chi: improving functional balance and predicting subsequent falls in older persons

PURPOSE: To determine whether improved functional balance through a Tai Chi intervention is related to subsequent reductions in falls among elderly persons. METHODS: Two hundred fifty-six healthy, physically inactive older adults aged 70-92 (mean age +/- SD = 77.48 +/- 4.95), recruited from a local health system in Portland, OR, participated in a 6-month randomized controlled trial, with allocation to Tai Chi or exercise stretching control, followed by a 6-month postintervention follow-up. Functional balance measures included Berg balance scale, dynamic gait index, and functional reach, assessed during the 6-month intervention period (baseline, 3-month, and 6-month intervention endpoint) and again at the 6-month postintervention follow-up. Fall counts were recorded during the 6-month postintervention follow-up period. Data were analyzed through intention-to-treat analysis of variance and logistic regression procedures. RESULTS: Tai Chi participants who showed improvements in measures of functional balance at the intervention endpoint significantly reduced their risk of falls during the 6-month postintervention period, compared with those in the control condition (odds ratio (OR), 0.27, 95% confidence interval (CI), 0.07-0.96 for Berg balance scale; OR, 0.27, 95% CI, 0.09-0.87 for dynamic gait index; OR, 0.20, 95% CI, 0.05-0.82 for functional reach). CONCLUSIONS: Improved functional balance through Tai Chi training is associated with subsequent reductions in fall frequency in older persons.     

Risk of non-medullary thyroid cancer influenced by polymorphic variation in the thyroglobulin gene

Benign thyroid disorders are strong risk factors for non-medullary thyroid cancer (NMTC). Germline variation in Tg (thyroglobulin) and TSHR (thyroid stimulating hormone receptor) confers an increased risk of benign thyroid disorders. To explore the hypothesis that polymorphic variation in these genes affects the risk of NMTC we compared the frequency of TgQ2511R, TSHR-P52T and TSHR-D727E genotypes in two series of NMTC cases and controls (group 1, Canadian 102 cases and 102 controls; group 2, British 202 cases and 298 controls). No significant association was seen with TSHR-P52T and TSHR-D727E genotypes and risk of NMTC. However, the frequency of the R-allele of TgQ2511R was over represented in NMTC cases in both study populations. The odds ratios associated with hetero- and homozygosity for the R-allele were 1.6 (95% confidence interval, 1.1-2.5) and 2.0 (95% confidence interval, 1.2-3.3), respectively. Although the risk of NMTC associated with the TgQ2511R R-allele is modest, its high prevalence in the general population suggests it may make a significant contribution to the incidence of NMTC.     

Acute reboxetine administration increases plasma and salivary cortisol

We investigated the effect of a single oral dose of the selective noradrenaline reuptake inhibitor, reboxetine (4 mg), on plasma and salivary cortisol in 24 healthy volunteers in a randomized, placebo-controlled, parallel-group design. Reboxetine significantly increased both plasma and salivary cortisol, although the correlation between the responses in plasma and saliva was modest. Our results are consistent with previous neuroendocrine challenge studies showing that potentiation of brain noradrenaline function stimulates the hypothalamic-pituitary-adrenal axis. Reboxetine-induced salivary cortisol release appears to be a simple and relatively non-invasive test of hypothalamic noradrenaline function. However, placebo-controlled, within-subject designs are likely to yield a more valid measure of noradrenaline-mediated cortisol release.     

Changes in jugular bulb oxygenation in patients undergoing warm coronary artery bypass surgery (34-37 degrees C)

BACKGROUND AND OBJECTIVE: Imbalance between cerebral oxygen supply and demand is thought to play an important role in the development of cerebral injury during cardiac surgery with cardiopulmonary bypass. METHODS: We studied jugular bulb oxygen saturation, jugular bulb oxygen tension, arterial-jugular bulb oxygen content difference and oxygen extraction ratio in 20 patients undergoing warm coronary artery bypass surgery (34-37 degrees C) with pH-stat blood gas management. RESULTS: Only two patients showed desaturation (jugular bulb oxygen saturation < 50%) at 5 min on bypass, and none from 20 min onwards. Multiple regression models were performed after using bypass temperature, mean arterial pressure, cerebral perfusion pressure, haemoglobin concentration and arterial carbon dioxide tension as independent variables, and arterial-jugular bulb oxygen content difference, jugular bulb oxygen saturation, oxygen extraction ratio and jugular bulb oxygen tension as individual dependent variables. CONCLUSIONS: We found that jugular bulb oxygen saturation, jugular bulb oxygen tension and oxygen extraction ratio are mainly dependent on arterial carbon dioxide tension, and arterial-jugular bulb oxygen content difference is dependent on arterial carbon dioxide tension and the bypass temperature. Our results suggest jugular bulb oxygenation is mainly dependent on arterial carbon dioxide tension during warm cardiopulmonary bypass.     

The role of rigidity in DNA looping-unlooping by AraC

We applied two experiments useful in the study of ligand-regulated DNA binding proteins to AraC, the dimeric regulator of the Escherichia coli l-arabinose operon. In the absence of arabinose, AraC prefers to loop DNA by binding to two half-sites that are separated by 210 base pairs, and in the presence of arabinose it prefers to bind to adjacently located half-sites. The basis for this ligand-regulated shift in binding appears to result from a shift in the rigidity of the system, where rigidity both in AraC protein in the absence of arabinose, and in the DNA are required to generate the free energy differences that produce the binding preferences. Eliminating the dimerization domains and connecting the two DNA binding domains of AraC by a flexible peptide linker should provide a protein whose behavior mimics that of AraC when there is no interaction between its dimerization and DNA binding domains. The resulting protein bound to adjacent half-sites on the DNA, like AraC protein in the presence of arabinose. When the two double-stranded DNA half-sites were connected by 24 bases of single-stranded, flexible DNA, wild-type AraC protein bound to the DNA in the presence and absence of arabinose with equal affinity, showing that AraC modulates its DNA binding affinity in response to arabinose by shifting the relative positions of its DNA binding domains. These results are consistent with the light switch mechanism for the action of AraC, refine the model, and extend the range of experimental tests to which it has been subjected.     

Hyper-fractionated radiotherapy for soft tissue sarcoma: results of the second study of hyper-fractionated radiotherapy

Purpose and Method. Hyper-fractionated radiotherapy for treatment of soft tissue sarcomas is designed to deliver a higher total dose of radiation without an increase in late normal tissue damage. In a previous study at the Royal Marsden Hospital, a total dose of 75 Gy using twice daily 1.25 Gy fractions resulted in a higher incidence of late damage than conventional radiotherapy using 2 Gy daily fractions treating to a total of 60 Gy. The current trial therefore used a lower dose per fraction of 1.2 Gy and lower total dose of 72 Gy, with 60 fractions given over a period of 6 weeks.Subjects. A total of 37 patients (22 males and 15 females) with a median age of 56 years (range 19-88 years) were treated.Results. Of eight patients treated pre-operatively, six showed a partial response and in two the tumour was static. The maximum acute toxicities were grade 1 in eight, grade 2 in 14 and grade 3 in 15 patients. Late toxicities of the skin were graded 1 in 10 and grade 2 in nine patients. Five patients complained of pain in the irradiated bone and soft tissues, which was of moderate severity (grade 2). Stiffness was graded 2 in three patients and severe (grade 3) in one.Three patients had moderate and one patient had severe lymphoedema following treatment. The 5-year recurrence-free survival probability of patients treated radically was 76%. Following excision of local recurrences the study group had a disease-free survival probability of 86% at 5 years.Discussion. The regime is well tolerated with comparable local control and late complication rates to standard daily fractionated therapy.The potential benefit of this regime needs to be defined in a prospective randomized trial.     

Emergence of fluoroquinolone‐resistant clonal group A: clonal analysis of Norwegian and Russian E. coli isolates

Strand L, Jenkins A, Grude N, Allum A‐G, Mykland H‐C, Nowrouzian FL, Kristiansen B‐E. Emergence of fluoroquinolone‐resistant clonal group A: clonal analysis of Norwegian and Russian E. coli isolates. APMIS 2010; 118: 571–77. We describe a study of urinary tract and intestinal isolates of Escherichia coli from Norway and Russia using automated ribotyping, single nucleotide polymorphism analysis for clonal group A (CgA) supplemented with phylogrouping, virulence gene profiling and resistance profiling. CgA comprised 19% of the Norwegian UTI isolates from 2001. Two highly multiresistant fluoroquinolone‐resistant CgA isolates were found. Ribotypes clustered into four major and six minor groups (ribogroups). Fluoroquinolone‐resistant isolates and phylogroups A and B1 were associated with ribogroup ^RA. Ribogroup ^RB predominated among Russian UTI isolates and was predominantly phylogroup A and depleted in P‐fimbriae. Ribogroup ^RC predominated among Norwegian UTI isolates and was rich in virulence factors (S‐fimbriae, haemagglutinin and haemolysin) and predominantly phylogroup B2 and D. Ribogroup ^RG was associated with CgA and predominantly phylogroup D. Ribogroups ^RD, ^RE and ^RF had too few members for statistical analysis. The correlation between ribotype and phylogenetic group was not as strong as reported in other studies.     

Effects of Short-Term Varenicline Administration on Emotional and Cognitive Processing in Healthy,Non-Smoking Adults: A Randomized,Double-Blind,Study

Varenicline is an effective and increasingly prescribed drug for smoking cessation, but has been associated with depressive symptoms and suicidal behavior. However, it remains unclear whether those changes in mood and behavior are directly related to varenicline use, or caused by smoking cessation itself or reflects depression and suicidality rates in smokers, independent of treatment. To investigate the influence of varenicline on mood and behavior independent of smoking and smoking cessation, we assessed the effects of varenicline on emotional processing (a biomarker of depressogenic effects), emotion-potentiated startle reactivity, impulsivity (linked with suicidal behavior), and cognitive performance in non-smoking subjects. We used a randomized, double-blind design, in which we administered varenicline or placebo to healthy subjects over 7 days (0.5 mg/day first 3 days, then 1 mg/day). Cognitive and emotional processing was assessed by a battery of computerized tasks and recording of emotion-potentiated startle response. A total of 41 subjects were randomized, with 38 subjects included in the analysis. The varenicline group did not differ from placebo in terms of negative biases in emotional processing or mood. However, compared with placebo, the varenicline group scored higher on working and declarative memory. In conclusion, short-term varenicline use did not influence negative biases in emotional processing or impulsivity in non-smoking subjects, thereby not supporting direct depressogenic or suicidal risk behavior-inducing effects. In contrast, varenicline may have cognitive-enhancing effects.