The strength ratio between hamstrings and quadriceps (H/Q) is associated with knee injuries as well as hip abductor muscle (HAB) weakness. Sixteen resistance trained men (age, 32.5 ± 4.2 years) performed 5 s maximal isometric contractions at 75° of knee flexion/extension and 15° of hip abduction on a dynamometer. After this isometric test they performed a Farmer's walk exercise to find out if the muscle strength ratio predicted the electromyography amplitude expressed as a percentage of maximum voluntary isometric contraction (%MVIC). The carried load represented a moderate intensity of 75% of the exercise six repetitions maximum (6RM). Electromyography data from the vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF) and gluteus medius (Gmed) on each leg were collected during the procedure. The groups selected were participants with H/Q ≥ 0.5, HQ < 0.5, HAB/H ≥ 1, HAB/H < 1, HAB/Q ≥ 0.5 and HAB/Q < 0.5. One way ANOVA showed that Gmed activity was significantly greater in the group with HAB/H < 1 (42 ± 14 %MVIC) as compared to HAB/H ≥ 1 (26 ± 10 %MVIC) and HAB/Q < 0.5 (47 ± 19 %MVIC) compared to HAB/Q ≥ 0.5 (26 ± 12 %MVIC). The individuals with HAB/H < 1 were found to have greater activation of their Gmed during the Farmer's walk exercise. Individuals with HAB/Q < 0.5 had greater activation of the Gmed. Gmed strength ratios predict the muscle involvement when a moderate amount of the external load is used. The Farmer's walk is recommended as an exercise which can strengthen the gluteus medius, especially for individuals with a HAB/H ratio < 1 and HAB/Q < 0.5.

• Publikační typ
• časopisecké články MeSH

• MeSH
• elektrokardiografie MeSH
• finanční podpora výzkumu jako téma MeSH
• hypertenze patofyziologie   MeSH
• hypertrofie levé komory srdeční diagnóza   patofyziologie   MeSH
• kontrakce myokardu MeSH
• krysa rodu rattus MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

OBJECTIVE: We evaluated response decrement during a short time repetitive low and high contrast reversal and low contrast motion stimulation in controls and migraineurs. METHODS: A total of 39 migraine patients (out of which 19 were in the interictal period and without prophylactic treatment) and 36 healthy volunteers were examined using pattern-reversal (PR-VEP) and motion-onset (M-VEP) visual evoked potentials. Binocular stimulation lasted 2.5 min and the decrement assessment was blinded. RESULTS: Evidence of significant decrement was observed in healthy volunteers for high contrast PR-VEP amplitude of P100-N75 ratios between the fifth and first blocks (0.9; p=0.001) with a linear decline (-0.7 μV/min, p=0.001) and in the P100-N145 amplitude with linear decline (-0.5 μV/min, p=0.004). Significant decrement was also observed for the ratio between the fifth and first block P1-N2 amplitudes in M-VEP (0.9, p=0.006). No significant decrement was noted in the low contrast PR-VEP or among migraineurs. CONCLUSIONS: We confirm differences in decrease of VEPs amplitude during short term examination between controls and migraineurs. We showed the decrement deficit also in the extrastriatal regions of the migraineurs' visual cortex. SIGNIFICANCE: Low contrast and motion-onset stimuli in short time decrement assessment did not increase the test sensitivity.

• MeSH
• dospělí MeSH
• fyzikální stimulace MeSH
• habituace (psychofyziologie) * MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• migréna diagnóza   patofyziologie   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• pohyb těles MeSH
• zrakové evokované potenciály * MeSH
• zrakové korové centrum patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky kontrolované MeSH
• práce podpořená grantem MeSH

Visual evoked potentials to motion-onset stimulation (M-VEPs) gradually attenuate in amplitude during examination. The observed decline in averaged responses can be caused by decreases in single response magnitudes and/or increased variability in a response delays, that is, latency jittering. To illuminate the origins of the suppression of M-VEPs during stimuli repetition, we used correlation technique to estimate an upper bound of possible latency jittering of single sweeps and we evaluated the effect of its correction on the amplitudes of three M-VEP dominant peaks P1, N2 and P3. During prolonged visual motion stimulation, the variability of corrective latency shifts in the occipital region increased (r = 0.35: 0.44) and the number of single responses corresponding to the average curve declined in occipital and parietal derivations (r = -0.48: -0.62). While the P1 peak amplitude did not exhibit any time-specific behaviour, the N2 amplitude exhibited a significant decay of 29.4% that was partially reduced to 16.6% in the central occipital derivation by the latency jitter and non-correspondence corrections. The strongest attenuation (32.7%) was observed in the P3 amplitude and was less sensitive to the corrections, dropping only to 27.9%. The main part of the response suppression to repeated motion stimulation was caused by amplitude drop and represents non-stationary process that likely correspond to a fatigue model. The rise of variability in latency jitter correction and the reduction in single responses correlated with the M-VEP were significant factors associated with prolonged motion stimulation. The relation of these parameters to a hypothetical veridical response is ambiguous and can be caused by a time shift of the response or by a change of signal-to-noise ratio. Using selective averaging and latency jitter correction, the effect of response suppression was partially removed.

• MeSH
• adaptace oční fyziologie   MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• rozpoznávání obrazu fyziologie   MeSH
• vnímání pohybu fyziologie   MeSH
• zrakové evokované potenciály fyziologie   MeSH
• zrakové korové centrum fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

International Laser Center, Bratislava, Slovak Republic. bacharvo@ilc.skThe aim of the study was to analyze the relationship between QRS amplitude and left ventricular mass (LVM) in early stages of two different experimental models of left ventricular hypertrophy (LVH) in rats: in exercise-induced hypertrophy and pathological hypertrophy due to genetically conditioned pressure overload. Three groups of experimental animals were studied: healthy control Wistar-Kyoto rats (WKYs), spontaneously hypertensive rats (SHRs), and WKY rats exposed to training by intermittent swimming (SWIM). Orthogonal electrocardiograms were recorded in each group at the age of 12 and 20 weeks, and the maximum spatial QRS vector (QRSmax) was calculated. Then the animals were sacrificed and LVM was measured. The specific potential of myocardium (SP) was calculated as a ratio of QRSmax to LVM. The QRSmax values did not follow the changes in LVM. At the end of the follow-up period, the highest values of QRSmax were recorded in the control WKY rats (0.80 +/- 0.05 mV). The QRSmax values in both groups with experimental LVH were significantly lower as compared with control animals (SHR 0.44 +/- 0.02 mV, p < 0.001; SWIM 0.53 +/- 0.04 mV, p < 0.001). Similarly, the SP values were significantly lower in both groups with experimental LVH as compared with control animals (SHR 0.42 +/- 0.02 mV/g, p < 0.001; SWIM 0.55 +/- 0.05 mV/g, p < 0.001). A decrease in QRSmax and SP was observed in both models of experimental LVH. We attributed these findings to the changes in electrogenetic properties of myocardium in the early stage of developing LVH. In other words, it is changes of nonspatial determinants that influence the resultant QRS voltage in terms of the solid angle theory.

• MeSH
• elektrokardiografie MeSH
• financování vládou MeSH
• hodnotící studie jako téma MeSH
• hypertrofie levé komory srdeční diagnóza   etiologie   patofyziologie   MeSH
• kondiční příprava zvířat škodlivé účinky   MeSH
• krysa rodu rattus MeSH
• srdeční komory radiografie   MeSH
• velikost orgánu MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH

PURPOSE: The natural course of lumbar spinal stenosis (LSS) fluctuates and is not necessarily progressive. The aim of this study was to explore the predictors of clinical outcome in patients with LSS that might eventually help to optimise the therapeutic choices. METHODS: A group of 56 patients (27 men, 29 women, median age 55; range 31-72 years) with clinically symptomatic mild-to-moderate LSS were re-examined after a median period of 88 months and their clinical outcomes classified as satisfactory (34 patients, 60.7 % with stable or improved clinical status) or unsatisfactory (22 patients, 39.3 % for whom clinical status deteriorated). A wide range of demographical, clinical, imaging and electrophysiological entry parameters were evaluated as possible predictors of clinical outcome. RESULTS: Unlike the demographical, clinical and imaging variables, certain electrophysiological parameters were significantly associated with unsatisfactory outcomes. There was a significantly higher prevalence of pluriradicular involvement detected by EMG in patients with unsatisfactory outcome than those with satisfactory outcome (68.2 vs. 32.3 %; p = 0.035). Patients with unsatisfactory outcome had more frequent bilateral abnormalities of the soleus H-reflex (50.0 vs. 14.7 %; p = 0.015) and lower mean H-reflex amplitude. Multivariate logistic regression proposed two variables as mutually independent predictors of unsatisfactory outcome: EMG signs of pluriradicular involvement (OR = 3.72) and averaged soleus H-reflex amplitude ≤ 2.8 mV (OR = 2.87). CONCLUSIONS: Satisfactory outcomes were disclosed in about 61 % of the patients with mild-to-moderate LSS in a 7-year follow-up. Electrophysiological abnormalities, namely the presence of pluriradicular involvement and abnormalities of the soleus H-reflex, were predictive of deterioration of clinical status in these patients.

• MeSH
• bederní obratle MeSH
• dospělí MeSH
• elektromyografie MeSH
• H-reflex fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• odds ratio MeSH
• progrese nemoci MeSH
• ROC křivka MeSH
• senioři MeSH
• spinální stenóza komplikace   patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Increased glycemic variability (GV) may be associated with diabetes complications. Our study assessed the relationship between microvascular complications (MVCs) and GV calculated from continuous glucose monitoring (CGM) data in type 1 diabetes patients. SUBJECTS AND METHODS: Thirty-two patients with type 1 diabetes (16 with and 16 without MVC) participated in this cross-sectional study. Vibration perception threshold (VPT), microalbuminuria, and fundoscopy were used to detect MVC. CGM data were recorded for 2 weeks and analyzed using proprietary software. Total SD (SDT), coefficient of variation (CV), and mean amplitude of glycemic excursions (MAGE) were compared. RESULTS: Patients with any MVC had significantly higher GV, calculated from CGM, than patients without MVC (SDT, 4.1 ± 0.6 vs. 3.4 ± 0.8 mmol/L [P = 0.010]; CV, 0.43 ± 0.06 vs. 0.38 ± 0.08 [P = 0.032]; MAGE, 6.9 ± 1.2 vs. 5.9 ± 1.2 mmol/L [P = 0.014]) but comparable glycated hemoglobin (HbA1c) (70 ± 9 vs. 69 ± 10 mmol/mol [8.6 ± 0.8% vs. 8.5 ± 0.9%], difference not significant). No significant difference in GV was found between the two groups when using only self-monitored blood glucose (SMBG) data. A positive association was found between VPT and SDT in all patients (r = 0.51, P = 0.0026). CONCLUSIONS: Patients with type 1 diabetes and any MVC had significantly higher GV calculated from CGM, but not from SMBG, than patients with comparable glycemic control but without complications. This supports the hypothesis that increased GV might be associated with MVC in type 1 diabetes and that HbA1c may not describe diabetes control completely.

• MeSH
• albuminurie MeSH
• ambulantní monitorování metody   MeSH
• analýza rozptylu MeSH
• biologické markery krev   MeSH
• diabetes mellitus 1. typu krev   komplikace   patofyziologie   MeSH
• diabetické angiopatie krev   etiologie   patofyziologie   MeSH
• dospělí MeSH
• glykovaný hemoglobin metabolismus   MeSH
• hodnocení rizik MeSH
• krevní glukóza metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• odds ratio MeSH
• prediktivní hodnota testů MeSH
• průřezové studie MeSH
• selfmonitoring glykemie MeSH
• vibrace MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: Inferolateral early repolarization (ER) is highly prevalent and is associated with idiopathic ventricular fibrillation (VF). OBJECTIVE: The purpose of this study was to evaluate the potential role of T-wave parameters to differentiate between malignant and benign ER. METHODS: We compared the ECGs of patients with ER and VF (n = 92) with control subjects with asymptomatic ER (n = 247). We assessed J-wave amplitude, QTc interval, T-wave/R-wave (T/R) ratio in leads II and V5, and presence of low-amplitude T waves (T-wave amplitude <0.1 mV and <10% of R-wave amplitude in lead I, II, or V4-V6). RESULTS: Compared to controls, the VF group had longer QTc intervals (388 ms vs. 377 ms, P = .001), higher J-wave amplitudes (0.23 mV vs. 0.17 mV, P <.001), higher prevalence of low-amplitude T waves (29% vs. 3%, P <.001), and lower T/R ratio (0.18 vs. 0.30, P <.001). Logistic regression analysis demonstrated that QTc interval (odds ratio [OR] per 10 ms: 1.15, 95% confidence interval [CI} 1.02-1.30), maximal J-wave amplitude (OR per 0.1 mV: 1.68, 95% CI 1.23-2.31), lower T/R ratio (OR per 0.1 unit: 0.62, 95% CI 0.47-0.81), presence of low-amplitude T waves (OR 3.53, 95% CI 1.26-9.88). and presence of J waves in the inferior leads (OR 2.58, 95% CI 1.18-5.65) were associated with malignant ER. CONCLUSION: Patients with malignant ER have a higher prevalence of low-amplitude T waves, lower T/R ratio (lead II or V5), and longer QTc interval. The combination of these parameters with J-wave amplitude and distribution of J waves may allow for improved identification of malignant ER.

• MeSH
• dospělí MeSH
• elektrokardiografie * MeSH
• fibrilace komor diagnóza   epidemiologie   patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• míra přežití trendy   MeSH
• následné studie MeSH
• prevalence MeSH
• převodní systém srdeční patofyziologie   MeSH
• retrospektivní studie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Evropa epidemiologie   MeSH

Cíl studie: Cílem studie bylo zjištění vztahů mezi manifestací tinnitu, nálezem na sluchových evokovaných potenciálech a genetickým pozadím u receptoru pro gamaaminomáselnou kyselinu typu A (GABA(A) receptor), podporující desinhibiční hypotézu vzniku tinnitu. Soubor a metodika: Bylo vyšetřeno 131 pacientů z hlediska sluchové ztráty, provedena kvantifikace tinnitu, sluchové evokované potenciály střední latence (MLR) a kmenové sluchové evokované potenciály (BAEP) a dále stanovení genotypu (CA)n repetitivní sekvence pro beta‑3 podjednotku GABA(A) receptoru. Následně byly hledány vztahy mezi jednotlivými výsledky a manifestací tinnitu. Výsledky: Byla nalezena korelace tinnitus skóre s amplitudovým poměrem vln V/III v BAEP (R = 0,22, p < 0,001) a s průměrným sluchovým prahem (R = 0,22, p = 0,17). Rovněž byla nalezena korelace tinnitus skóre s amplitudou vlny PA v MLR (R = 0,31–0,37; p < 0,001). Výsledky MLR neukázaly žádný vztah k průměrnému sluchovému prahu. U skupiny s kratší anamnézou tinnitu (méně než devět měsíců) byl prokázán rozdíl v manifestaci tinnitu na genotypu pro (CA)n repetitivní sekvenci genu pro beta‑3 podjednotku GABA(A) receptoru (p = 0,002). Tento výsledek byl rovněž konzistentní s rozložením amplitudy vlny PA v dané subpopulaci. Závěr: Tyto výsledky svědčí o existenci dvou hlavních regulačních mechanizmů vzniku tinnitu: první, který je závislý na velikosti sluchové ztráty, je na úrovni mozkového kmene, zatímco druhý je na úrovni korové s možnou souvislostí s genotypem (CA)n repetitivní sekvence pro beta‑3 podjednotku GABA(A) receptoru.

Study aim:Study objective was to explore associations between manifestation of tinnitus, auditory evoked potentials and genetic background of gamma‑aminobutyric acid type A (GABA(A) receptors) to support the disinhibited feedback hypothesis of tinnitus generation. Materials and methods: A population of 131 patients was assessed for severity of hearing loss, quantification of tinnitus, mid‑latency responses (MLR) and brainstem auditory evoked potentials (BAEP), and (CA)n tandem repeat polymorphism in GABA(A) Beta‑3 subunit gene to establish any correlation with manifestation of tinnitus. Results: It was observed that tinnitus score correlates with V/III amplitude ratio in BAEP (R = 0.22, p < 0.001) and with mean pure tone audiometry (PTA) threshold (R = 0.22, p = 0.017). Analysis of the MLR results showed a significant correlation between the PA wave amplitude and the tinnitus score (R = 0.31–0.37; p < 0.001). MLR result analysis showed no statistically significant correlation between the wave amplitudes and the mean auditory threshold. An analysis of a subgroup with shorter clinical history (less than nine months) revealed a statistically significant difference in the tinnitus score in relation to the genotype of (CA)n tandem repeat of the GABRß3 receptor subunit gene (p = 0.002). This result was also consistent with the distribution of the PA wave amplitude in the given subpopulation. Conclusion: Our findings indicate existence of two main regulatory mechanisms of tinnitus generation: first, the brainstem mechanism is dependent on the severity of the hearing loss; second, the cortical mechanism is likely to be dependent on the genotype of (CA)n tandem repeat in GABA(A) beta‑3 subunit gene.

• MeSH
• akustická stimulace metody   MeSH
• audiometrie čistými tóny * využití   MeSH
• dospělí MeSH
• genotyp MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• koncové repetice genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mozkový kmen fyziologie   MeSH
• receptory GABA-A * fyziologie   genetika   MeSH
• senioři MeSH
• sluchová dráha fyziologie   MeSH
• sluchové evokované potenciály * fyziologie   genetika   MeSH
• sluchový práh * fyziologie   MeSH
• tinnitus * diagnóza   genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• práce podpořená grantem MeSH

OBJECTIVE: Changes in the N20/P25 amplitude of somatosensory evoked potentials (SEP) of the median nerve have been found to correlate with those in cortical regional cerebral blood flow (rCBF). Our study presents the use of median nerve SEP amplitude in predicting the clinical outcome of urgent surgical internal carotid artery (ICA) recanalization. METHODS: A total of 27 patients suffering an acute ischemic stroke (AIS) with extracranial ICA occlusion within 24 h were prospectively recruited. The primary preoperative endpoints included the SEP amplitude absolute value (SEP-amp) and the SEP amplitude side-to-side ratio (SEP-ratio). Clinical outcome at 3 months postoperatively was assessed using the modified Rankin scale (mRS-3M). RESULTS: The positive predictive values (PPVs) for SEP-amp and SEP-ratio were 95.5% and 100%, respectively, with the negative predictive values (NPVs) being 60.0% and 100%, respectively. The SEP-ratio correlated fully with mRS-3M. CONCLUSION: The median SEP side-to-side N20/P25 amplitude ratio seems to be a very strong positive and negative predictor of the clinical outcome of urgent recanalization of an extracranial ICA occlusion. SIGNIFICANCE: The results suggest that cortical evoked activity may help in selection patient for surgical recanalization and predict clinical recovery after an acute ischemic stroke.

• MeSH
• arteria carotis interna patofyziologie   chirurgie   MeSH
• ischemická cévní mozková příhoda diagnóza   chirurgie   MeSH
• lidé MeSH
• pooperační komplikace epidemiologie   MeSH
• prognóza MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• somatosenzorické evokované potenciály * MeSH
• výkony cévní chirurgie škodlivé účinky   metody   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH