Association of Tagging Single Nucleotide Polymorphisms on 8 Candidate Genes in Dopaminergic Pathway with Schizophrenia in Croatian Population

Aim

To perform a comprehensive evaluation of association of common genetic variants in candidate genes in the dopaminergic pathway with schizophrenia in a sample from Croatian population.

Methods

A case-control association study was performed on 104 unrelated patients with schizophrenia recruited from a psychiatric hospital in Zagreb and 131 phenotypically normal Croatian subjects. Forty-nine tagging single nucleotide polymorphisms (tagSNPs) in 8 candidate genes in the dopaminergic pathway were identified from the HapMap database and tested for association. Genotyping was performed using the SNPlex platform. Statistical analysis was conducted to assess allelic and genotypic associations between cases and controls using a goodness of fit χ² test and trend test, respectively; adjustment for multiple testing was done by permutation based analysis.

Results

Significant allele frequency differences between schizophrenia cases and controls were observed at 4 tagSNPs located in the genes DRD5, HTR1B1, DBH, and TH1 (P < 0.005). A trend test also confirmed the genotypic association (P < 0.001) of these 4 tagSNPs. Additionally, moderate association (P < 0.05) was observed with 8 tagSNPs on SLC6A3, DBH, DRD4, SLC6A4, and COMT.

Conclusions

Common genetic variants in genes involved in the dopaminergic pathway are associated with schizophrenia in the populations of Caucasian descent.Schizophrenia is a chronic, severe, and disabling brain disease affecting about 1% of the global population (1). There is substantial evidence that genetic factors are involved in the etiology of the disease (2). High heritability (~ 80%) and higher concordance in monozygotic (~ 50%) than in dizygotic (~ 17%) twins are strong indicators for an inherited basis of schizophrenia (3-5). During the past decade, numerous loci and plausible candidate genes have been identified by linkage and association studies. However, the findings have remained inconclusive (2,6). Like other complex diseases, a complex genetic etiology compounded by involvement of other non-genetic factors has hindered the precise identification of schizophrenia gene variants. Second, a major limitation in most association studies has been testing of a few variants within a gene of interest rather than a thorough assessment of the entire gene region. With the availability of the sequence of the genome and large body of data on human genetic variation from the HapMap project (7), it is now possible to undertake more comprehensive association studies.Genes involved in the dopamine pathway are biologically plausible candidates in schizophrenia susceptibility. In this study, we report on the association of single nucleotide polymorphisms (SNPs) in 8 dopaminergic genes (DRD4, DRD5, SLC6A3, SLC6A4, HTR1B, DBH, TH, and COMT) with schizophrenia in a Caucasian sample from Croatia. We performed a comprehensive association study using tagging SNPs (tagSNPs). Overall, 49 tagSNPs were identified from the HapMap database (7), 4 of which showed strong evidence of association with schizophrenia susceptibility.     

Crack/cocaine users show more family problems than other substance users

OBJECTIVES:

To evaluate family problems among crack/cocaine users compared with alcohol and other substance users.

METHODS:

A cross-sectional multi-center study selected 741 current adult substance users from outpatient and inpatient Brazilian specialized clinics. Subjects were evaluated with the sixth version of the Addiction Severity Index, and 293 crack users were compared with 126 cocaine snorters and 322 alcohol and other drug users.

RESULTS:

Cocaine users showed more family problems when compared with other drug users, with no significant difference between routes of administration. These problems included arguing (crack 66.5%, powder cocaine 63.3%, other drugs 50.3%, p = 0.004), having trouble getting along with partners (61.5%×64.6%×48.7%, p = 0.013), and the need for additional childcare services in order to attend treatment (13.3%×10.3%×5.1%, p = 0.002). Additionally, the majority of crack/cocaine users had spent time with relatives in the last month (84.6%×86.5%×76.6%, p = 0.011).

CONCLUSIONS:

Brazilian treatment programs should enhance family treatment strategies, and childcare services need to be included.     

Multidrug resistance 1 gene polymorphisms may determine Crohn's disease behavior in patients from Rio de Janeiro

OBJECTIVES:

Conflicting data from studies on the potential role of multidrug resistance 1 gene polymorphisms in inflammatory bowel disease may result from the analysis of genetically and geographically distinct populations. Here, we investigated whether multidrug resistance 1 gene polymorphisms are associated with inflammatory bowel diseases in patients from Rio de Janeiro.

METHODS:

We analyzed 123 Crohn''s disease patients and 83 ulcerative colitis patients to determine the presence of the multidrug resistance 1 gene polymorphisms C1236T, G2677T and C3435T. In particular, the genotype frequencies of Crohn''s disease and ulcerative colitis patients were analyzed. Genotype-phenotype associations with major clinical characteristics were established, and estimated risks were calculated for the mutations.

RESULTS:

No significant difference was observed in the genotype frequencies of the multidrug resistance 1 G2677T/A and C3435T polymorphisms between Crohn''s disease and ulcerative colitis patients. In contrast, the C1236T polymorphism was significantly more common in Crohn''s disease than in ulcerative colitis (p = 0.047). A significant association was also found between the multidrug resistance 1 C3435T polymorphism and the stricturing form of Crohn''s disease (OR: 4.13; p = 0.009), whereas no association was found with penetrating behavior (OR: 0.33; p = 0.094). In Crohn''s disease, a positive association was also found between the C3435T polymorphism and corticosteroid resistance/refractoriness (OR: 4.14; p = 0.010). However, no significant association was found between multidrug resistance 1 gene polymorphisms and UC subphenotypic categories.

CONCLUSION:

The multidrug resistance 1 gene polymorphism C3435T is associated with the stricturing phenotype and an inappropriate response to therapy in Crohn''s disease. This association with Crohn''s disease may support additional pathogenic roles for the multidrug resistance 1 gene in regulating gut-microbiota interactions and in mediating fibrosis. Understanding the effects of several drugs associated with multidrug resistance 1 gene variants may aid in the selection of customized therapeutic regimens.     

Sex Differences in Head Acceleration During Heading While Wearing Soccer Headgear

Context:

Researchers have indicated that female soccer players may be at greater risk of concussion compared with their male counterparts. Soccer headgear is marketed for reducing head acceleration and risk of concussion.

Objective:

To determine the effect of sex and soccer headgear on head impact kinematics and dynamic stabilization during soccer heading.

Design:

Cross-sectional design.

Setting:

Research laboratory.

Patients or Other Participants:

Forty-four college-aged soccer players (29 women, 15 men).

Intervention(s):

Using a head impact model, participants performed 4 soccer headers under 3 headgear conditions (control, Head Blast Soccer Band, and Full90 Select Performance Headguard).

Main Outcome Measure(s):

Dependent variables assessed before soccer heading were head-neck anthropometrics and isometric neck muscle strength, and those assessed during soccer headers were resultant linear head acceleration, Head Injury Criteria (HIC₃₆), and superficial neck muscle electromyography. Statistical analyses included multivariate and univariate analyses of variance with repeated measures, independent-samples t tests, appropriate follow-up analyses of variance and post hoc t tests, and Pearson product moment correlations (α  =  .05).

Results:

Head acceleration in women was 32% and 44% greater than in men when wearing the Head Blast (21.5 g versus 16.3 g) and Full90 Select (21.8 g versus 15.2 g), respectively (P < .05). Compared with men, women exhibited 10% greater head accelerations (20.2 g versus 18.2 g) during the control condition (P  =  .164).

Conclusions:

Female soccer players exhibited greater head accelerations than their male counterparts when wearing headgear. Our results are important clinically because they indicate that soccer headgear may not be an appropriate head injury prevention tool for all athletes.     

Reliability and Validity of a Novel Muscle Contusion Device

Context:

Many models have been employed to replicate skeletal muscle injury associated with trauma; however, most are restricted to 1 level of severity.

Objective:

To create and validate an injury-producing device that could generate multiple levels of injury severity.

Design:

Validation study.

Patients or Other Participants:

Twenty-six male Wistar rats, 3 to 4 months old.

Intervention(s):

A contusion device was developed and its ability to deliver consistent impacts was validated alone and in the presence of an experimental animal. A free-falling mass (267 g) was adjusted to the desired height (40, 50, 60, or 70 cm) and then dropped.

Main Outcome Measure(s):

Peak load, peak displacement, impulse, energy, and velocity peak were measured. Injury severity was determined using magnetic resonance imaging.

Results:

Outcome measures observed from the device alone were different by height (F_18,136  =  21.807, P < .001, 1−β  =  1.0). Outcomes using the experimental animals were also dependent on height (F_14,102  =  68.679, P < .001, 1−β  =  1.0). Linear regression analyses indicated that height accounted for 17% to 89% of the variance.

Conclusions:

Mild to moderate and moderate to severe injuries can be replicated with this device, which will be useful in evaluating clinical treatments on acute muscle injury.     

Insomnia with Objective Short Sleep Duration is Associated with Deficits in Neuropsychological Performance: A General Population Study

Study Objectives:

To examine the joint effect of insomnia and objective short sleep duration on neuropsychological performance.

Design:

Representative cross-sectional study.

Setting:

Sleep laboratory.

Participants:

1,741 men and women randomly selected from central Pennsylvania.

Interventions:

None.

Measurements:

Insomnia (n = 116) was defined by a complaint of insomnia with a duration ≥ 1 year and the absence of sleep disordered breathing (SDB), while normal sleep (n = 562) was defined as the absence of insomnia, excessive daytime sleepiness, and SDB. Both groups were split according to polysomnographic sleep duration into 2 categories: ≥ 6 h of sleep (“normal sleep duration”) and < 6 h of sleep (“short sleep duration”). We compared the groups'' performance on a comprehensive neuropsychological battery that measured processing speed, attention, visual memory, and verbal fluency, while controlling for age, race, gender, education, body mass index, and physical and mental health.

Results:

No significant differences were detected between insomniacs and controls. However, the insomnia with short sleep duration group compared to the control with normal or short sleep duration groups showed poorer neuropsychological performance in variables such as processing speed, set-switching attention, and number of visual memory errors and omissions. In contrast, the insomnia with normal sleep duration group showed no significant deficits.

Conclusions:

Insomnia with objective short sleep duration is associated with deficits in set-switching attentional abilities, a key component of the “executive control of attention.” These findings suggest that objective sleep duration may predict the severity of chronic insomnia, including its effect on neurocognitive function.

Citation:

Fernandez-Mendoza J; Calhoun S; Bixler EO; Pejovic S; Karataraki M; Liao D; Vela-Bueno A; Ramos-Platon MJ; Sauder KA; Vgontzas AN. Insomnia with objective short sleep duration is associated with deficits in neuropsychological performance: a general population study. SLEEP 2010;33(4):459-465.     

Changes in Serum TSH and Free T4 during Human Sleep Restriction

Study Objectives:

To examine whether recurrent sleep restriction is accompanied by changes in measures of thyroid function.

Design:

Two-period crossover intervention study.

Setting:

University clinical research center and sleep laboratory.

Participants:

11 healthy volunteers (5F/6M) with a mean (± SD) age of 39 ± 5 y and BMI 26.5 ± 1.5 kg/m².

Intervention:

Randomized exposure to 14 days of sedentary living with ad libitum food intake and 5.5- vs. 8.5-h overnight sleep opportunity.

Measurements and Results:

Serum thyroid-stimulating hormone (TSH) and free thyroxine (T4) were measured at the end of each intervention. Partial sleep restriction was accompanied by a modest but statistically significant reduction in TSH and free T4, seen mainly in the female participants of the study.

Conclusions:

Compared to the well-known rise in TSH and thyroid hormone concentrations during acute sleep loss, tests obtained after 14 days of partial sleep restriction did not show a similar activation of the human thyroid axis.

Citation:

Kessler L; Nedeltcheva A; Imperial J; Penev PD. Changes in serum TSH and free T4 during human sleep restriction. SLEEP 2010;33(8):1115-1118.     

The Relationships Among Sagittal-Plane Lower Extremity Moments: Implications for Landing Strategy in Anterior Cruciate Ligament Injury Prevention

Context:

Excessive quadriceps contraction with insufficient hamstrings muscle cocontraction has been shown to be a possible contributing factor for noncontact anterior cruciate ligament (ACL) injuries. Assessing the relationships among lower extremity internal moments may provide some insight into avoiding muscle contraction patterns that increase ACL injury risk.

Objective:

To examine the relationships of knee-extensor moment with ankle plantar-flexor and hip-extensor moments and to examine the relationship between knee moment and center of pressure as a measure of neuromuscular response to center-of-mass position.

Design:

Cross-sectional study.

Setting:

Applied Neuromechanics Research Laboratory.

Patients or Other Participants:

Eighteen healthy, recreationally active women (age  =  22.3 ± 2.8 years, height  =  162.5 ± 8.1 cm, mass  =  57.8 ± 9.3 kg).

Intervention(s):

Participants performed a single-leg landing from a 45-cm box onto a force plate. Kinetic and kinematic data were collected.

Main Outcome Measure(s):

Pearson product moment correlation coefficients were calculated among the net peak knee-extensor moment (KEMpk), sagittal-plane ankle (AM) and hip (HM) net internal moments, and anterior-posterior center of pressure relative to foot center of mass at KEMpk (COP).

Results:

Lower KEMpk related to both greater AM (r  =  −0.942, P < .001) and HM (r  =  −0.657, P  =  .003). We also found that more anterior displacement of COP was related to greater AM (r  =  −0.750, P < .001) and lower KEMpk (r  =  0.618, P  =  .006).

Conclusions:

Our results suggest that participants who lean the whole body forward during landing may produce more plantar-flexor moment and less knee-extensor moment, possibly increasing hip-extensor moment and decreasing knee-extensor moment production. These results suggest that leaning forward may be a technique to decrease quadriceps contraction demand while increasing hamstrings cocontraction demand during a single-leg landing.     

Upper Airway Sensory Function in Children with Obstructive Sleep Apnea Syndrome

Study Objectives:

Children with the obstructive sleep apnea syndrome (OSAS) have impaired responses to hypercapnia, subatmospheric pressure, and inspiratory resistive loading during sleep. This may be due, in part, to an impairment in the afferent limb of the upper airway sensory pathway. Therefore, we hypothesized that children with OSAS had diminished upper airway sensation compared to controls.

Design:

Case-control

Setting:

Academic hospital

Participants:

Subjects with OSAS aged 6–16 years, and age- and BMI-matched controls.

Interventions:

Two-point discrimination (TPD) was measured during wakefulness with modified calipers in the anterior tongue, right interior cheek, and hard palate.

Results:

Thirteen children with OSAS and 9 controls were tested. The age (mean ± SD) for OSAS and controls was 11 ± 4 vs. 13 ± 2 years (NS); OSAS BMI Z score 2.4 ± 0.5, controls 2.2 ± 0.5 (NS); OSAS apnea hypopnea index 31 ± 48, controls 0.4 ± 0.5 events/hour (P < 0.001). Children with OSAS had impaired TPD in the anterior tongue (median [range]) = 9 [3–14] mm, controls 3 [1–7], P = 0.002) and hard palate (OSAS 6 [3–9] mm, controls 3 [1–4], P < 0.001). TPD in the cheek was similar between the groups (P = 0.12).

Conclusion:

TPD in the anterior tongue and hard palate was impaired in children with OSAS during wakefulness. We speculate that this impairment might be due to a primary sensory function abnormality or secondary to nerve damage and/or hypoxemia caused by OSAS. Further studies after treatment of OSAS are needed.

Citation:

Tapia IE; Bandla P; Traylor J; Karamessinis L; Huang J; Marcus CL. Upper airway sensory function in children with obstructive sleep apnea syndrome. SLEEP 2010;33(7):968–972.     

Obstructive Sleep Apnea Syndrome Is Associated with Overactive Bladder and Urgency Incontinence in Men

Study Objective:

To investigate the incidence of overactive bladder (OAB) and urgency incontinence (UI) in men with obstructive sleep apnea syndrome (OSAS).

Design:

Prospective questionnaire study

Setting:

Saarland University Hospital

Patients:

All male patients who underwent full-night in-laboratory polysomnography between November 2006 and April 2007.

Interventions:

Overactive bladder symptom score (OABSS) and International Consultation on Incontinence Questionnaire, Short-Form (ICIQ-SF).

Measurements and Results:

OSAS severity was assessed according to the apnea-hypopnea-index (AHI). Return rate of questionnaires was 100% (n = 100). Patients with upper airway resistance syndrome (UARS) served as controls. Evaluation of OABSS revealed that patients with moderate and severe OSAS presented with a significantly higher incidence of symptoms of OAB than patients with mild OSAS and UARS (P < 0.05). Further, the ICIQ-SF revealed a higher occurrence of UI in patients with severe OSAS than in those with mild OSAS and UARS (P < 0.05).

Conclusions:

Increasing severity of OSAS appears to be associated with an increasing occurrence of overactive bladder and urgency incontinence in men. This relationship may have clinical implications for the treatment of affected patients.

Citation:

Kemmer H; Mathes AM; Dilk O; Gröschel A; Grass C; Stöckle M. Obstructive Sleep Apnea Syndrome Is Associated with Overactive Bladder and Urgency Incontinence in Men. SLEEP 2009;32(2):271-275.     

Online social networks and smoking cessation: a scientific research agenda

Background

Smoking remains one of the most pressing public health problems in the United States and internationally. The concurrent evolution of the Internet, social network science, and online communities offers a potential target for high-yield interventions capable of shifting population-level smoking rates and substantially improving public health.

Objective

Our objective was to convene leading practitioners in relevant disciplines to develop the core of a strategic research agenda on online social networks and their use for smoking cessation, with implications for other health behaviors.

Methods

We conducted a 100-person, 2-day, multidisciplinary workshop in Washington, DC, USA. Participants worked in small groups to formulate research questions that could move the field forward. Discussions and resulting questions were synthesized by the workshop planning committee.

Results

We considered 34 questions in four categories (advancing theory, understanding fundamental mechanisms, intervention approaches, and evaluation) to be the most pressing.

Conclusions

Online social networks might facilitate smoking cessation in several ways. Identifying new theories, translating these into functional interventions, and evaluating the results will require a concerted transdisciplinary effort. This report presents a series of research questions to assist researchers, developers, and funders in the process of efficiently moving this field forward.     

Insomnia with Short Sleep Duration and Mortality: The Penn State Cohort

Study Objectives:

Because insomnia with objective short sleep duration is associated with increased morbidity, we examined the effects of this insomnia subtype on all-cause mortality.

Design:

Longitudinal.

Setting:

Sleep laboratory.

Participants:

1,741 men and women randomly selected from Central Pennsylvania.

Measurements:

Participants were studied in the sleep laboratory and were followed-up for 14 years (men) and 10 years (women). “Insomnia” was defined by a complaint of insomnia with duration ≥ 1 year. “Normal sleeping” was defined as absence of insomnia. Polysomnographic sleep duration was classified into two categories: the “normal sleep duration group” subjects who slept ≥ 6 h and the “short sleep duration group” subjects who slept < 6 h. We adjusted for age, race, education, body mass index, smoking, alcohol, depression, sleep disordered breathing, and sampling weight.

Results:

The mortality rate was 21% for men and 5% for women. In men, mortality risk was significantly increased in insomniacs who slept less than 6 hours compared to the “normal sleep duration, no insomnia” group, (OR = 4.00, CI 1.14-13.99) after adjusting for diabetes, hypertension, and other confounders. Furthermore, there was a marginally significant trend (P = 0.15) towards higher mortality risk from insomnia and short sleep in patients with diabetes or hypertension (OR = 7.17, 95% CI 1.41-36.62) than in those without these comorbid conditions (OR = 1.45, 95% CI 0.13-16.14). In women, mortality was not associated with insomnia and short sleep duration.

Conclusions:

Insomnia with objective short sleep duration in men is associated with increased mortality, a risk that has been underestimated.

Citation:

Vgontzas AN; Liao D; Pejovic S; Calhoun S; Karataraki M; Basta M; Fernández-Mendoza J; Bixler EO. Insomnia with short sleep duration and mortality: the Penn State Cohort. SLEEP 2010;33(9):1159-1164.     

Lack of Association of the APOE ε4 Allele with the Risk of Obstructive Sleep Apnea: Meta-Analysis and Meta-Regression

Study Objectives:

Reports on the association of polymorphisms in the gene encoding apolipoprotein E (APOE)—a vital macromolecule in cholesterol metabolism—with obstructive sleep apnea (OSA) have provided conflicting results. Our objective was to meta-analytically synthesize the existing evidence for the association of the APOE ε4 allele with the risk of OSA.

Design:

Random effects meta-analysis and meta-regression

Setting:

Genetic epidemiological studies reporting the association of APOE ε4 allele with OSA susceptibility.

Patients or Participants:

Synthesis of APOE ε4 allele data from 6,508 subjects including 1,901 cases of OSA and 4,607 controls.

Interventions:

None

Measurements and Results:

Eight studies were included in the random effects meta-analysis; the summary effect size measured as odds ratio (OR) for association of the APOE ε4 allele with the risk of OSA was found to be 1.13 (95% confidence interval 0.86–1.47). There was a statistically significant heterogeneity (I² = 72%, P = 0.001) across study results that was not explained by the mean age, proportion of males, or the proportion possessing the APOE ε4 allele or when grouped based on the geographic location of the study.

Conclusions:

The hypothesis that the APOE ε4 allele may be causally associated with OSA cannot be supported on the basis of published literature.

Citation:

Thakre TP; Mamtani MR; Kulkarni H. Lack of association of the APOE ε4 allele with the risk of obstructive sleep apnea: meta-analysis and meta-regression. SLEEP 2009;32(11):1507-1511.     

Self-Reported Health and Fitness Habits of Certified Athletic Trainers

Context:

As health care providers, certified athletic trainers (ATs) should be role models for healthy behaviors.

Objective:

To analyze the self-reported health and fitness habits of ATs.

Design:

A cross-sectional, cluster random sample.

Setting:

Online questionnaire.

Patients or Other Participants:

Of a sampling frame of 1000 potential participants, 275 ATs completed the questionnaire.

Main Outcome Measure(s):

Health habits and activity were based on a typical 7-day week.

Results:

A total of 41% of the participants met the exercise recommendations of the American College of Sports Medicine; 7% reported being sedentary. Differences were noted between the sexes for fitness habits (P < .035) and composite health score (P < .001). None of the ATs reported meeting the Daily Reference Intake for all 5 food groups. Seven percent of female ATs consumed more alcohol than recommended, compared with 2% of males. However, 80% of males and 93% of females reported consuming 5 or fewer drinks per week. Only 0.8% reported currently smoking.

Conclusions:

This sample of ATs had better health and fitness habits than the general population but did not meet professional recommendations set forth by the American College of Sports Medicine or the United States Department of Agriculture. Thus, these ATs were not ideal role models in demonstrating healthy behaviors.     

Curricular Satisfaction Levels of National Athletic Trainers' Association–Accredited Postprofessional Athletic Training Graduates

Context:

Academic programs rely on outcomes assessments to determine if changes in the curriculum are necessary.

Objective:

To examine the overall satisfaction levels of graduates (2005–2006) of National Athletic Trainers'' Association–accredited postprofessional athletic training education programs as related to the 2002 Standards and Guidelines for Development and Implementation of NATA-Accredited Post-Professional Graduate Athletic Training Education Programs.

Design:

Original survey instrument and demographic questionnaire.

Setting:

Online survey instrument.

Patients or Other Participants:

Of 211 survey recipients, 123 returned surveys (58.29% response rate).

Main Outcome Measure(s):

Demographic information and satisfaction levels in 10 standard areas (depth of learning, breadth of learning, critical thinking, instructor availability, theoretic basis, writing skills, scholarly growth, community return, leadership, and overall program satisfaction) were obtained. Satisfaction scores were categorized into 10 percentage brackets (eg, 80%–89%) for each standard area.

Results:

No differences were noted in relation to any of the standard satisfaction areas for evaluation of time off from school. However, graduates who required more than the allotted amount of time to complete their degree were less satisfied in the areas of depth of learning (P  =  .027), breadth of learning (P  =  .001), instructor availability (P  =  .005), writing (P  =  .022), and overall program satisfaction (P  =  .016).

Conclusions:

Graduates were generally satisfied across all areas of their didactic curriculum. However, satisfaction levels were affected if graduates required more than the allotted amount of time to complete their degrees.     

Muscle Activation and Movement Patterns During Prone Hip Extension Exercise in Women

Context:

The consistency of muscle activation order during prone hip extension has been debated.

Objective:

To investigate whether women use a consistent and distinguishable muscle activation order when extending the hip while prone and to explore the effects of verbal cues on muscle activation and movement.

Design:

Single-session, repeated-measures design.

Setting:

University laboratory.

Patients or Other Participants:

Eleven healthy women (age  =  27.7 ± 6.2 years [range, 22–37 years]).

Intervention(s):

We tested the participants under 3 conditions: no cues, cues to contract the gluteal muscles, and cues to contract the hamstrings muscles.

Main Outcome Measure(s):

We measured hip and knee angle and electromyographic data from the gluteus maximus, medial hamstrings, and lateral hamstrings while participants performed prone hip extension from 30° of hip flexion to neutral.

Results:

When not given cues, participants used the consistent and distinguishable muscle activation order of medial hamstrings, followed by lateral hamstrings, then gluteus maximus (195.5 ± 74.9, 100.2 ± 70.3, and 11.5 ± 81.9 milliseconds preceding start of movement, respectively). Compared with the no-cues condition, the gluteal-cues condition resulted in nearly simultaneous onset of medial hamstrings, lateral hamstrings, and gluteus maximus (131.3 ± 84.0, 38.8 ± 96.9, and 45.1 ± 93.4 milliseconds, respectively) (P > .059); decreased activation of the medial hamstrings (P < .03) and lateral hamstrings (P < .024) around the initiation of movement; increased activation of gluteus maximus throughout the movement (P < .001); and decreased knee flexion (P  =  .002). Compared with the no-cues condition, the hamstrings-cues condition resulted in decreased activation of the medial hamstrings just after the initiation of movement (P  =  .028) and throughout the movement (P  =  .034) and resulted in decreased knee flexion (P  =  .003).

Conclusions:

Our results support the contention that the muscle activation order during prone hip extension is consistent in healthy women and demonstrates that muscle timing and activation amplitude and movement can be modified with verbal cues. This information is important for clinicians using prone hip extension as either an evaluation tool or a rehabilitation exercise.     

Symptomatic and Functional Responses to Concentric-Eccentric Isokinetic Versus Eccentric-Only Isotonic Exercise

Context:

Rehabilitation protocols involving eccentric resistance exercise performed with loading more than 100% concentric 1-repetition maximum are effective in increasing muscle function in both healthy and injured populations. The mode of eccentric exercise (isokinetic versus isotonic) may be an important factor in limiting symptoms of delayed-onset muscle soreness and in improving muscle function after training.

Objective:

To compare functional and symptomatic responses after an eccentric-only (ECC) isotonic exercise protocol and after a combined concentric-eccentric (CON-ECC) isokinetic exercise protocol matched for total exercise volume.

Design:

Observational study.

Setting:

Controlled research laboratory.

Patients or Other Participants:

Twenty-four healthy, untrained, college-aged men (n  =  12) and women (n  =  12).

Intervention(s):

Participants were randomly assigned to the ECC isotonic or CON-ECC isokinetic exercise group and performed a single bout of resistance exercise involving the elbow flexors.

Main Outcome Measure(s):

Measurements of elbow flexion and extension, isometric strength, and muscle point tenderness were obtained before exercise (baseline) and during follow-up sessions (days 2, 4, 7, and 14). Separate 1-way analyses of variance and repeated-measures analyses of variance were used to determine outcome differences. Tukey post hoc testing was performed when indicated.

Results:

At baseline, no differences were present between groups for any measure. The ECC isotonic exercise protocol resulted in a 30% to 36% deficit in muscle strength, a 5% to 7% reduction in elbow flexion, and a 6% to 8% reduction in elbow extension at follow-up days 2 and 4 (P < .01). The CON-ECC isokinetic exercise protocol did not alter muscle strength or range of motion at any time when compared with baseline. Muscle point tenderness increased from baseline on days 2 and 4 in both groups (P < .05) but was not different between groups throughout the recovery period.

Conclusions:

Our results indicated more pronounced functional deficits occurred after a single bout of ECC isotonic exercise than with a CON-ECC isokinetic exercise protocol matched for training volume.     

Interleukin-6 and the IL-6 (–174) C/G polymorphism in breast pathologies and in HIV-infected patients

Introduction

Breast cancer and acquired immunodeficiency syndrome (AIDS) are key issues for modern medicine. The aim of the current study was to present how cytokines, in the example of IL-6 and its polymorphism, can affect these two conditions.

Material and methods

Thirty-one women with benign breast tumours, 42 breast cancer patients and 40 HIV-infected females were enrolled in the study. Serum IL-6 levels were determined by ELISA. The IL-6 polymorphism was genotyped by PCR-RFLP.

Results

Serum IL-6 in patients with benign breast tumours was significantly lower than in females with breast cancer (p = 0.017) and HIV-infected women (p = 0.032). We did not find statistically significant differences in serum IL-6 level between females with breast cancer and HIV-infected women (p = 0.749). Comparing the distribution of genotypes and frequency of the IL-6 (–174) C/G polymorphism between the three study groups – breast cancer patients, patients with benign breast tumours, and HIV-infected patients – we did not find any statistically significant differences.

Conclusions

IL-6 can play an important role in pathogenesis of breast cancer and HIV infection and its level is higher than in the control group irrespective of distribution of genotypes and frequency of the IL-6 (–174) C/G polymorphism.     

Athletic Training Approved Clinical Instructors' Reports of Real-Time Opportunities for Evaluating Clinical Proficiencies

Context:

Appropriate methods for evaluating clinical proficiencies are essential to ensuring entry-level competence in athletic training.

Objective:

To identify the methods Approved Clinical Instructors (ACIs) use to evaluate student performance of clinical proficiencies.

Design:

Cross-sectional design.

Setting:

Public and private institutions in National Athletic Trainers'' Association (NATA) District 4.

Patients or Other Participants:

Approved Clinical Instructors from accredited athletic training education programs in the Great Lakes Athletic Trainers'' Association, which is NATA District 4 (N  =  135).

Data Collection and Analysis:

Participants completed a previously validated survey instrument, Methods of Clinical Proficiency Evaluation in Athletic Training, that consisted of 15 items, including demographic characteristics of the respondents and Likert-scale items (1  =  strongly disagree to 5  =  strongly agree) regarding methods of clinical proficiency evaluation, barriers, educational content areas, and clinical experience settings. We used analyses of variance and 2-tailed, independent-samples t tests to assess differences among ACI demographic characteristics and the methods, barriers, educational content areas, settings, and opportunities for feedback regarding clinical proficiency evaluation. Qualitative analysis of respondents'' comments was completed.

Results:

The ACIs (n  =  106 of 133 respondents, 79.7%) most often used simulations to evaluate clinical proficiencies. Only 59 (55.1%) of the 107 ACIs responding to a follow-up question reported that they feel students engage in a sufficient number of real-time evaluations to prepare them for entry-level practice. An independent-samples t test revealed that no particular clinical experience setting provided more opportunities than another for real-time evaluations (t₁₁₉ range, −0.909 to 1.796, P ≥ .05). The occurrence of injuries not coinciding with the clinical proficiency evaluation timetable (4.00 ± 0.832) was a barrier to real-time evaluations. Respondents'' comments indicated much interest in opportunities and barriers regarding real-time clinical proficiency evaluations.

Conclusions:

Most clinical proficiencies are evaluated via simulations. The ACIs should maximize real-time situations to evaluate students'' clinical proficiencies whenever feasible. Athletic training education program administrators should develop alternative methods of clinical proficiency evaluations.