73 research outputs found
Реконструкция системы электроснабжения ОАО «СтанкоГомель» в связи с изменением технологического процесса и разработкой энергосберегающих мероприятий
The aim of the present study was to compare an ultrasonically activated instrument (US), monopolar electrosurgery, and bipolar electrosurgery (ES) with respect to heat production, nerve function, and nerve morphology following in vivo application. less thanbrgreater than less thanbrgreater thanThe biceps femoris muscle of anesthetized rats was cut in a standardized manner longitudinally 1 mm adjacent to the sciatic nerve using US shears, a monopolar ES knife, or a bipolar ES scissors. Activation time and temperature were recorded continuously within 1-4 mm of the activation site ipsilateral and contralateral to the nerve with two thermoelectric microsensors. Temperature rise and time delay of reaching the temperature maximum, as an expression of heat spread within tissue, maximum temperature, and thermal dose (equivalent time of exposure at 43A degrees C) were measured and calculated. A total of 49 functional experiments were conducted. The electromyographic (EMG) potential was recorded distally. Nerve dysfunction was defined as more than 10% loss of the evoked EMG amplitude. Forty-eight nerves were coded and submitted to blind histopathological examination, and morphological damage was graded on a 4-grade scale. less thanbrgreater than less thanbrgreater thanThe maximum temperature elevation and the thermal dose were significantly higher for the bipolar ES compared with the US instrument ( = 0.024, = 0.049), and with much less variation of results for the US instrument. The monopolar ES maximum temperature and thermal dose were lower, but a very large variation occurred, probably as a result of more random electrical spread to the ground electrode and muscle motion artifacts. Functional loss was least common in the US group-without being significant-compared to bipolar and monopolar ES. Moderate and severe morphological damage was significantly less common in the US group than in the monopolar ES group ( = 0.041). We found no statistically significant correlation between the highest temperatures and the degree of morphological damage or functional loss less thanbrgreater than less thanbrgreater thanThe temperature elevation depends strongly on the distance to the activated instrument. The bipolar ES scissors generates a higher maximum temperature and thermal dose with a greater variation in than the US. Functional loss and severe morphological damage were uncommon in all groups.Funding Agencies|FORSS|
Weight reduction is not a major reason for improvement in rheumatoid arthritis from lacto-vegetarian, vegan or Mediterranean diets
OBJECTIVES: Several investigators have reported that clinical improvements of patients with rheumatoid arthritis (RA), from participating in therapeutic diet intervention studies, have been accompanied by loss of body weight. This has raised the question whether weight reduction per se can improve RA. In order to test this hypothesis, three previously conducted diet intervention studies, comprising 95 patients with RA, were pooled. Together with Age, Gender, and Disease Duration, change during the test period in body weight, characterised dichotomously as reduction or no reduction (dichoΔBody Weight), as well as Diet (dichotomously as ordinary diet or test diet), were the independent variables. Dependent variables were the difference (Δ) from baseline to conclusion of the study in five different disease outcome measures. ΔESR and ΔPain Score were both characterised numerically and dichotomously (improvement or no improvement). ΔAcute Phase Response, ΔPhysical Function, and ΔTender Joint Count were characterised dichotomously only. Multiple logistic regression was used to analyse associations between the independent and the disease outcome variables. RESULTS: Statistically significant correlations were found between Diet and three disease outcome variables i.e. ΔAcute-Phase Response, ΔPain Score, and ΔPhysical Function. Δ Body Weight was univariately only correlated to ΔAcute-Phase Response but not significant when diet was taken into account. CONCLUSION: Body weight reduction did not significantly contribute to the improvement in rheumatoid arthritis when eating lacto-vegetarian, vegan or Mediterranean diets
The effects of upper and lower limb exercise on the microvascular reactivity in limited cutaneous systemic sclerosis patients
Background: Aerobic exercise in general and high intensity interval training (HIIT) specifically is known to improve vascular function in a range of clinical conditions. HIIT in particular has demonstrated improvements in clinical outcomes, in conditions that have a strong macroangiopathic component. Nevertheless, the effect of HIIT on microcirculation in systemic sclerosis (SSc) patients is yet to be investigated. Therefore, the purpose of the study was to compare the effects of two HIIT protocols (cycle and arm cranking) on the microcirculation of the digital area in SSc patients.
Methods: Thirty four limited cutaneous SSc patients (65.3 ± 11.6 years old) were randomly allocated in three groups (cycling, arm cranking and control group). The exercise groups underwent a twelve-week exercise program twice per week. All patients performed the baseline and post-exercise intervention measurements where physical fitness, functional ability, transcutaneous oxygen tension (ΔtcpO2), body composition and quality of life were assessed. Endothelial-dependent as well as-independent vasodilation were assessed in the middle and index fingers using LDF and incremental doses of acetylcholine (ACh) and sodium nitroprusside (SNP). Cutaneous flux data were expressed as cutaneous vascular conductance (CVC).
Results: Peak oxygen uptake increased in both exercise groups (p<0.01, d=1.36). ΔtcpO2 demonstrated an increase in the arm cranking group only, with a large effect, but not found statistically significant,(p=0.59, d=0.93). Endothelial-dependent vasodilation improvement was greater in the arm cranking (p<0.05, d=1.07) in comparison to other groups. Both exercise groups improved life satisfaction (p<0.001) as well as reduced discomfort and pain due to Raynaud's phenomenon (p<0.05). Arm cranking seems to be the preferred mode of exercise for study participants as compared to cycling (p<0.05). No changes were observed in the body composition or the functional ability in both exercise groups.
Conclusion: Our results suggest that arm cranking has the potential to improve the microvascular endothelial function in SSc patients. Also notably, our recommended training dose (e.g., a 12-week HIIT program, twice per week), appeared to be sufficient and tolerable for this population. Future research should focus on exploring the feasibility of a combined exercise such as aerobic and resistance training by assessing individual's experience and the quality of life in SSc patients.
Trial registration: ClinicalTrials.gov (NCT number): NCT03058887, February 23, 2017, https://clinicaltrials.gov/ct2/show/NCT03058887?term=NCT03058887&rank=1
Key words: High intensity interval training, vascular function, quality of lif
Asymmetric dimethylarginine and total homocysteine in plasma after oral methionine loading
Background: Elevation of homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) in plasma are believed to be involved in the pathogenesis of cardiovascular disease (CVD). In humans, oral methionine loading results in acute elevation of plasma Hcy. This is associated with impaired NO-dependent vasodilatation, a mechanism that may explain the relationship between elevated Hcy and risk of CVD. ADMA, an endogenous competitive inhibitor of NO-synthase, may be elevated in plasma of patients with CVD. It was proposed that ADMA is synthesized in a methionine-dependent reaction which also forms Hcy. In this study plasma total homocysteine (tHcy) and ADMA concentrations were measured before and after oral methionine loading of human subjects. Methods: Plasma tHcy and ADMA levels were measured in 12 healthy males (age 32-58 years) before and after oral loading with L-methionine (100 mg/kg body weight in orange juice). Results: At noon, 4 h after methionine loading, tHcy and ADMA levels (35.4 +/- 10.9 and 0.80 +/- 0.13 mumol/L, mean +/-SD) were significantly higher than the corresponding values obtained at noon the day before (15.6 +/- 7.4 and 0.63 +/- 0.10 mumol/L, both p < 0.001). Noon values 4 h after methionine loading were also significantly higher than values obtained immediately before the methionine load (13.7 &PLUSMN; 5.9 and 0.66 &PLUSMN; 0.10 μmol/L, both p < 0.001). Reinvestigation of 8 of 12 subjects showed that at 4 and 8 h after compared with levels immediately before methionine loading there was a significant increase in tHcy (28.4 +/- 10.2 and 33.45 +/- 11.1 vs. 10.8 +/- 3.3 mumol/L, both p < 0.001). However, the corresponding ADMA levels did not increase (0.73 &PLUSMN; 0.17 and 0.76 &PLUSMN; 0.22 vs. 0.70 &PLUSMN; 0.10 μmol/L, both not significant). Conclusions: No clear evidence was found to support the supposition that methionine-induced hyperhomocysteinaemia may be accompanied by elevated levels of ADMA, an endogenous competitive NO-synthase inhibitor that may represent an alternative pathogenic mechanism for homocysteine-associated impairment of endothelial NO-dependent functions
Albumin-to-alkaline phosphatase ratio may be a better predictor of survival than sclerostin, dickkopf-1, osteopontin, osteoprotegerin and osteocalcin
Objectives: The value of biochemical markers of bone turnover (BTMs) in predicting survival and disease remains unclear. In a prospective study we evaluated the novel biomarkers for bone turnover sclerostin, dickkopf-1 (DKK-1), osteopontin (OPN), osteoprotegerin (OPG) and osteocalcin (OC), as well as a traditional biomarker, alkaline phosphatase (ALP) in relation to risk of mortality, cardiovascular events and fractures. Participants: and Methods:Routine blood tests and serum BTMs, including ALP, were analyzed in patients with hip fracture n = 97, stroke n = 71 and healthy volunteers n = 83 (mean age 86, 83 and 77, respectively), followed for 7 years. Hazard Ratios (HR) were calculated for mortality, cardiovascular events and fractures in relation to these biomarkers. After adding the albumin-to-ALP ratio (AAPR) a post hoc analysis was performed. Results: 120 participants died during the study. In the entire group of patients and volunteers (n = 251) higher AAPR (HR 0.28, 95 % CI 0.14–0.59, p < 0.001) was associated with decreased mortality. OPN and OPG were associated with mortality risk only in the univariate statistical analysis. HR for high AAPR in relation to new cardiovascular events was borderline significant (HR 0.29, 95 % CI 0.08–1.06, p = 0.061). None of the examined biomarkers were associated with new fractures, nor with an increased risk of a new cardiovascular event. Conclusions: AAPR may be a better predictor of mortality than the more novel BTMs, and higher AAPR could be associated with longer life expectancy. Further studies should determine the clinical usefulness of AAPR as a biomarker of mortality and cardiovascular disease
Alterations in bone turnover markers in patients with noncardio-embolic ischemic stroke.
BackgroundThe major cause of ischemic stroke is unstable or thrombogenic atherosclerotic plaques. Vascular calcification, a process that appears crucial for plaque stability, shares common features with bone formation. Many bone turnover proteins exhibit metabolic properties, but the evidence is conflicting regarding their possible involvement in vascular disease. Antibodies against sclerostin and dickkopf-1 are currently being evaluated as potential therapy for treating bone disorders. It is important to carefully assess the cardiovascular and metabolic effects of these proteins. The aim of the present study was to explore serum levels of bone turnover markers in patients with acute noncardio-embolic ischemic stroke in comparison with healthy controls.MethodsIn a cross-sectional study, we compared 48 patients aged ≥75 years with noncardio-embolic ischemic stroke and 46 healthy controls. Serum levels of dickkopf-1, sclerostin, osteoprotegerin, osteopontin and osteocalcin were determined by Luminex technique.ResultsWe found clearly increased serum levels of osteoprotegerin, sclerostin, dickkopf-1 and osteopontin in patients with stroke compared with healthy controls. No difference was seen in serum levels of osteocalcin between the two groups.ConclusionOur findings strengthen the hypothesis of bone turnover markers being involved in vascular disease. Whether these proteins can be used as candidate markers for increased stroke risk or prognostic biomarkers remains to be further elucidated
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