The Reliability of 1- and 3Rm Tests of Unilateral Strength in Trained and Untrained Men and Women

The purpose of this study was to determine the reliability of the 1- and 3RM tests for the modified unilateral squat. Thirty untrained (22 women, 8 men) and 22 trained (12 women, 10 men) subjects participated in the study. The trained group had a minimum of 1 year lower-body training experience but had not participated in unilateral training prior to the study. After practicing proper technique with light loads, the subjects used the barbell squat to complete a 1- and 3RM pretest and posttest. In each group half of the subjects completed the 1RM tests prior to the 3RM tests while half of the subjects completed the 3RM tests first. A rest period of 48 hours was allowed between each test. Twenty subjects, randomly selected from the two groups, completed a third session of the 1RM test 3 days after the 1RM posttest. Intraclass correlation coefficients were recorded. Differences between pre- and posttest measures were determined by the paired-sample t-test. The 1- and 3RM tests were found to be significantly reliable for trained men, r = 0.98 and r = 0.97, untrained men, r = 0.99 and r = 0.97, trained women r = 0.99 and r = 0.94, and untrained women, r = 0.97 and r = 0.87, respectively. Posttest scores for the 1- and 3RM tests significantly improved above baseline levels in each group (p < 0.05). Strength scores did not significantly increase during the third 1RM test (p = 0.22). The data indicate that the modified unilateral squat can be measured with high reliability using the 1- and 3RM tests. The improved posttest scores indicate that a pretest session should take place before recording baseline measurements.

Key Points

• The modified unilateral squat is a reliable test for trained and untrained men and women.
• The 1RM and 3RM tests are reliable and safe for trained and untrained subjects.
• A practice session and pretest should be conducted prior to baseline testing.

Key words: Single-leg strength, unilateral squat, resistance exercise     

The relationship between levels of PCBs and pesticides in human hair and blood: preliminary result

Human hair as a biologic measure of exposure to persistent organic pollutants (POPs) has some advantages over the more commonly used blood and adipose tissue samples. However, one of the primary limitations is the difficulty in distinguishing between exogenous and endogenous contamination. In addition, there are currently no standardized methods for hair sample collection, washing, and chemical analysis. There is also very limited information describing the correlation between levels of organic contaminants in hair and other body compartments. To explore levels of POPs in blood and hair, samples from 10 volunteers were collected and analyzed for select organochlorine pesticides and 57 individual polychlorinated biphenyl (PCB) congeners. We demonstrated that the method for analyzing organic contaminants in human hair was reliable and reproducible. Washing hair with shampoo decreased levels of PCBs, pesticides, and lipids by 25-33% on average and up to 62% for low-chlorinated congeners. The percentage of lipids and the levels of organochlorines in hair were higher than in serum. We found strong correlation (r = 0.8) between p,p -DDE (dichlorodiphenyldichloroethylene) levels in hair and blood and moderate correlations for the more persistent PCB congeners, but no correlations or weak correlations for other organochlorines. The present study provides preliminary evidence on the utility of hair analysis for POPs; however, further larger studies are recommended before hair analysis can be successfully applied in epidemiologic studies on POPs.     

Sarizotan,a serotonin 5-HT<Subscript>1A</Subscript> receptor agonist and dopamine receptor ligand. 1. Neurochemical profile

Summary. Sarizotan exhibited high affinities only to serotonin 5-HT_1A receptors and dopamine DA D₄>D₃>D₂ receptors with the profile of a 5-HT_1A agonist and DA antagonist demonstrated by the inhibition of cAMP-stimulation and guinea pig ileum contraction, decreased accumulation of the 5-HT precursor 5-hydroxytryptophan and increased levels of 5-HT metabolites, increased accumulation of DA precursor dihydroxyphenylalanine (DOPA) and the reduced levels of DA metabolites in intact rats. However, sarizotan at higher doses decreased DA precursor accumulation in reserpinized rats and induced contralateral rotational behavior in unilaterally substantia nigra lesioned rats, indicating some intrinsic dopaminergic activity; at D₂ receptors sarizotan may act as a partial agonist, depending on the dopaminergic impulse flow. Sarizotan represents a new approach for the treatment of extrapyramidal motor complications such as l-DOPA-induced dyskinesia in Parkinsons disease.     

Facial closure: interrelationship with facial discrimination, other closure tests, and subjective contour illusions

Findings from previous research have argued for the dissociation of two visual-perceptual tasks traditionally thought to be mediated by the nondominant hemisphere (i.e. perceptual closure and facial discrimination). This, primarily methodological, study examined the extent to which the facial closure measure (Mooney closure faces test) involves "closure" and/or facial discrimination. A factor analysis of six visual perceptual measures, carried out separately for left brain damaged (LBDs, n=33) and right brain damaged (RBDs, n=30) patients, resulted in two relatively independent factors (i.e. a closure factor and a facial discrimination factor), with the Mooney closure faces test loading on both. The mixed factorial structure did not aid the facial closure measure's sensitivity to right-sided brain disease. Moreover, age and education intercorrelated differently with the two factors. Results argue for the use of more discrete visual-perceptual measures when examining perceptual functioning and/or right hemisphere integrity, and imply the existence of at least two discrete cortical level visual-perceptual neural systems.     

Glove use and the relative risk of acute hand injury: a case-crossover study

The purpose of this study was to investigate the relationship between glove use and acute traumatic occupational hand injury. We used a case-crossover, within-subject study design to control for differences between individuals such as occupation, injury history, age, gender, risk-taking behavior, manual dexterity, and muscle strength. A total of 1166 hand-injured workers were interviewed regarding the use of gloves at the time of the injury. The self-reported average duration of glove use in the previous work month was the measure of expected exposure to wearing gloves. Nineteen percent of subjects reported wearing gloves at the time of the injury. The expected exposure to glove use in the past work month was 27.9%. Glove use was associated with a lower risk of lacerations and punctures but not crush, fractures, avulsions, amputations, dislocations; the risk of the former two injury types was estimated to be 60-70% lower while wearing gloves. Glove use is only one component of a comprehensive hand injury prevention approach that might include the identification and elimination of sharp hazards, engineering controls, safety warnings, training in high-risk situation awareness, and proper selection and timing of glove use.     

Suppression of angiogenesis and tumor growth by selective inhibition of angiopoietin-2

Angiopoietin-2 (Ang2) exhibits broad expression in the remodeling vasculature of human tumors but very limited expression in normal tissues, making it an attractive candidate target for antiangiogenic cancer therapy. To investigate the functional consequences of blocking Ang2 activity, we generated antibodies and peptide-Fc fusion proteins that potently and selectively neutralize the interaction between Ang2 and its receptor, Tie2. Systemic treatment of tumor-bearing mice with these Ang2-blocking agents resulted in tumor stasis, followed by elimination of all measurable tumor in a subset of animals. These effects were accompanied by reduced endothelial cell proliferation, consistent with an antiangiogenic therapeutic mechanism. Anti-Ang2 therapy also prevented VEGF-stimulated neovascularization in a rat corneal model of angiogenesis. These results imply that specific Ang2 inhibition may represent an effective antiangiogenic strategy for treating patients with solid tumors.     

Devices for rapid diagnosis of Malaria: evaluation of prototype assays that detect Plasmodium falciparum histidine-rich protein 2 and a Plasmodium vivax-specific antigen

The ParaSight F test was developed as a pioneer industry effort in the large-scale, process-controlled production of a device for the rapid diagnosis of malaria. This device performed well in field settings but was limited to the detection of a single malaria species, Plasmodium falciparum. The ParaSight F+V assay advanced upon the ParaSight F test format by incorporating a monoclonal antibody directed against a proprietary Plasmodium vivax-specific antigen, in addition to the antibody directed against P. falciparum histidine-rich protein 2, which was used in the ParaSight F assay. The modified assay was developed to add the capability to detect P. falciparum and P. vivax in a single-test-strip format. The present study evaluated three distinct ParaSight F+V prototypes with samples from symptomatic patients in regions of Thailand and Peru where malaria is endemic. Over a 2-year enrollment period (1998 and 1999), a total of 4,894 patients consented to participation in the study. Compared with the results for duplicate microscopic examinations of Giemsa-stained blood smears as the reference diagnostic standard, each successive prototype showed substantial improvement in performance. The final ParaSight F+V prototype, evaluated in 1999, had an overall sensitivity for detection of asexual P. falciparum parasites of 98%. The sensitivity of the device was 100% for P. falciparum densities of >500 parasites/ micro l, with a sensitivity of 83% for parasite densities of 5,000/ micro l, 92% for parasite densities of 1,001 to 5,000/ micro l, 94% for parasite densities of 501 to 1,000/ micro l, and 55% for parasite densities of 1 to 500/ micro l. The specificity for the exclusion of P. vivax was 87%. The areas under the receiver operating characteristic curves for the diagnostic performance of the assay for the detection of P. falciparum and P. vivax were 0.8907 and 0.8522, respectively. These findings indicate that assays for rapid diagnosis have the potential to enhance diagnostic capabilities in those instances in which skilled microscopy is not readily available.     

Six year effectiveness of a population based two tier infant hearing screening programme

Aims: To determine whether a two tier universal infant hearing screening programme (population based risk factor ascertainment and universal distraction testing) lowered median age of diagnosis of bilateral congenital hearing impairment (CHI) >40 dB HL in Victoria, Australia. Methods: Comparison of whole population birth cohorts pre and post introduction of the Victorian Infant Hearing Screening Program (VIHSP). All babies surviving the neonatal period born in Victoria in 1989 (pre-VIHSP) and 1993 (post-VIHSP) were studied. (1) Pre-1992: distraction test at 7–9 months. (2) Post-1992: infants with risk factors for CHI referred for auditory brain stem evoked response (ABR) assessment; all others screened by modified distraction test at 7–9 months. Results: Of the 1989 cohort (n = 63 454), 1.65/1000 were fitted with hearing aids for CHI by end 1995, compared with 2.09/1000 of the 1993 cohort (n = 64 116) by end 1999. Of these, 79 cases from the 1989 cohort (1.24/1000) and 72 cases from the 1993 cohort (1.12/1000) had CHI >40 dB HL. Median age at diagnosis of CHI >40 dB HL for the 1989 birth cohort was 20.3 months, and for the 1993 cohort was 14.2 months. Median age at diagnosis fell significantly for severe CHI but not for moderate or profound CHI. Significantly more babies with CHI >40 dB HL were diagnosed by 6 months of age in 1993 than in 1989 (21.7% v 6.3%). Compared to the six years pre-VIHSP, numbers aided by six months were consistently higher in the six years post-VIHSP (1.05 per 100 000 births versus 13.4 per 100 000 births per year). Conclusions: VIHSP resulted in very early diagnosis for more infants and lowered median age of diagnosis of severe CHI. However, overall results were disappointing.     

Burden of end-stage renal disease among indigenous peoples in Australia and New Zealand

Rates of end-stage renal disease (ESRD) among indigenous people in Australia and New Zealand are considerably higher than the non-indigenous population. This trend, apparent for several years, is described here using data from the Australia & New Zealand Dialysis and Transplant (ANZDATA) Registry. The average age at start of renal replacement therapy (RRT) is approximately 10 years less than non-indigenous people. Among those starting RRT, rates of "diabetic nephropathy" are higher among indigenous patients, reflecting higher rates of diabetes. The increased burden of illness extends to coronary artery disease and chronic lung disease, which are present at rates 1.5 to 2 times non-indigenous rates. Once dialysis treatment has commenced, indigenous people are less likely to be placed on the active cadaveric transplant waiting list, and less likely to receive a graft. Overall mortality outcomes are poorer for indigenous patients overall, and for each RRT modality. These outcomes are not simply due to increased frequency of co-morbid illness: for indigenous people receiving dialysis treatment the mortality rate adjusted for age and gender is around 11/2 times the non-indigenous rate. These data are consistent with studies showing increased rates of markers of early renal disease (in particular albuminuria) among both Australian and New Zealand indigenous groups, and reflect a broader health profile marked by high rates of diabetes, cardiovascular disease and chronic lung disease. Addressing these issues is a major challenge for health care providers in these regions.