Effects of therapeutic ultrasound on the endothelial function of patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterized by endothelial dysfunction that causes micro- and macrovascular complications. Low intensity therapeutic ultrasound (LITUS) may improve endothelial function, but its effects have not been investigated in these patients. The aim of our study was to compare the effects of pulsed (PUT) and continuous (CUT) waveforms of LITUS on the endothelium-dependent vasodilation of T2DM patients. The present randomized crossover trial had a sample of twenty-three patients (7 men) diagnosed with T2DM, 55.6 (±9.1) years old, with a body mass index of 28.6 (±3.3) kg/m2. All patients were randomized and submitted to different waveforms (Placebo, CUT, and PUT) of LITUS and the arterial endothelial function was evaluated. The LITUS of 1 MHz was applied in pulsed (PUT: 20% duty cycle, 0.08 W/cm2 SATA), continuous (CUT: 0.4 W/cm2 SPTA), and Placebo (equipment off) types of waves during 5 min on the brachial artery. Endothelial function was evaluated using the flow-mediated dilation (FMD) technique. PUT (mean difference 2.08%, 95% confidence interval 0.65 to 3.51) and CUT (mean difference 2.32%, 95% confidence interval 0.89 to 3.74) increased the %FMD compared to Placebo. In the effect size analysis, PUT (d=0.65) and CUT (d=0.65) waveforms presented moderate effects in the %FMD compared to Placebo. The vasodilator effect was similar in the different types of waves. Pulsed and continuous waveforms of LITUS of 1 MHz improved the arterial endothelial function in T2DM patients.

Quality of life and functional capacity in depressive patients on hemodialysis: a systematic review and meta-analysis

Depression is a common disorder in patients with chronic kidney disease (CKD), and some data support its relationship with functional capacity and quality of life. However, to date, this has not been evaluated systematically or through meta-analysis. We sought to investigate the relationship of quality of life and functional capacity with depressive disorder in patients with CKD on hemodialysis. This systematic review considered studies published up to 2021 and included cross-sectional and cohort studies. PubMed, Embase, SPORTDiscus, Web of Science, and Cochrane (CENTRAL) databases were used to search for studies. The New Castle-Ottawa Quality Assessment scale was used to measure the quality of the studies. A total of 4,626 studies were found and, after applying the selection criteria, 16 studies (2,175 patients) remained for qualitative analysis and 10 for meta-analysis (1,484 patients). The physical component summary (MD=-6.563; 95%CI: −9.702 to −3.424) and mental component summary (MD=-18.760; 95%CI: −28.641 to −8.879) were lower in depressive patients, as in all Short Form Health Survey 36 (SF-36) domains. Only one study provided data regarding functional capacity, but it was not evaluated by the defined outcome measure. Twelve studies were classified as "moderate quality" (5 to 6 stars) and four were classified as "low-quality" (0 to 4 stars). This meta-analysis with CKD patients on hemodialysis showed a negative relationship between depression and quality of life, with worsening in all physical and mental domains of the SF-36 in depressed patients.

Oxidative stress is involved in LLLT mechanism of action on skin healing in rats

The skin injury healing process involves the main phases of homoeostasis, inflammation, proliferation, and remodeling. The present study aimed to analyze the effects of low-level laser therapy (LLLT) on hematological dynamics, oxidative stress markers, and its relation with tissue healing following skin injury. Wistar rats were divided into control, sham, skin injury, and skin injury LLLT. The biochemical and morphological analyses were performed in the inflammatory (1 and 3 days) and regenerative phases (7, 14, and 21 days) following injury. The skin injury was performed in the dorsal region, between the intrascapular lines, using a surgical punch. LLLT (Al-Ga-In-P, λ=660 nm, energy density of 20 J/cm2, 30 mW power, and a time of 40 s) was applied at the area immediately after injury and on every following day according to the experimental subgroups. LLLT maintained hematocrit and hemoglobin levels until the 3rd day of treatment. Surprisingly, LLLT increased total leukocytes levels compared to control until the 3rd day. The effects of LLLT on mitochondrial activity were demonstrated by the significant increase in MTT levels in both inflammatory and regenerative phases (from the 1st to the 7th day), but only when associated with skin injury. The results indicated that LLLT modulated the inflammatory response intensity and accelerated skin tissue healing by a mechanism that involved oxidative damage reduction mostly at early stages of skin healing (inflammatory phase).

Cryotherapy: biochemical alterations involved in reduction of damage induced by exhaustive exercise

When exercises are done in intense or exhaustive modes, several acute biochemical mechanisms are triggered. The use of cryotherapy as cold-water immersion is largely used to accelerate the process of muscular recovery based on its anti-inflammatory and analgesic properties. The present study aimed to study the biochemical effects of cold-water immersion treatment in mice submitted to exercise-induced exhaustion. Swiss albino mice were divided into 4 treatment groups: control, cold-water immersion (CWI), swimming exhaustive protocol (SEP), and SEP+CWI. Treatment groups were subdivided into times of analysis: 0, 1, 3, and 5 days. Exhaustion groups were submitted to one SEP session, and the CWI groups submitted to one immersion session (12 min at 12°C) every 24 h. Reactive species production, inflammatory, cell viability, and antioxidant status were assessed. The SEP+CWI group showed a decrease in inflammatory damage biomarkers, and reactive species production, and presented increased cell viability compared to the SEP group. Furthermore, CWI increased acetylcholinesterase activity in the first two sessions. The present study showed that CWI was an effective treatment after exercise-induced muscle damage. It enhanced anti-inflammatory response, decreased reactive species production, increased cell viability, and promoted redox balance, which could decrease the time for the recovery process.

Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

Alterações hematológicas provocadas pelo ultra-som de 1MHz na forma contínua aplicadas no tratamento da fase aguda de lesão muscular iatrogênica em ratos / Hematological changes produced by 1MHz continuous ultrasound, applied during the acute phase of iatrogenic muscle injury in rats

CONTEXTUALIZAÇÃO: A literatura demonstra o efeito benéfico da terapia ultra-sônica de baixa intensidade sobre o processo de cicatrização de vários tecidos. OBJETIVO: Avaliar o efeito do ultra-som contínuo (USC) sobre a dinâmica hematológica do processo inflamatório agudo de lesão muscular iatrogênica. MÉTODOS: Foram utilizados 16 ratos da raça Wistar (350 a 400g), divididos em grupo controle (GC=8) e grupo experimental (G1=8), submetidos à incisão cirúrgica na face lateral do membro posterior direito, onde o músculo bíceps femoral foi lesionado transversalmente. O USC (1MHz) foi aplicado sobre o local da lesão a uma intensidade de 0,4W/cm², durante três minutos, na 1ª, 8ª e 24ª hora após a lesão. Nestes períodos, foram realizadas as coletas de sangue por punção venosa do plexo retroorbital para as análises sangüíneas das séries brancas e vermelhas. RESULTADOS: O USC diminui 8 por cento dos eritrócitos na primeira coleta (9,9±0,1 versus 7,8±0,1; x10(5)/mm³, p<0,001); dobrou os neutrófilos segmentados na segunda coleta (3.166,8±161,4 versus 6.426,2±306,0; x10³/mm³ p=0,008) e os eosinófilos na terceira coleta (2.883,6±99,0 versus 4.714,4±275,2; x10³/mm³ p=0,011) em relação ao GC. Não se observaram diferenças entre os grupos no hematócrito, leucócitos totais, neutrófilos bastonetes, monócitos e linfócitos, nos três momentos estudados. CONCLUSÕES: A aplicação do USC no tratamento agudo de lesão muscular é contra-indicada nesta condição, pois promove a redução dos eritrócitos, aumento dos neutrófilos segmentados e dos eosinófilos, favorecendo a hemorragia e o aumento do processo inflamatório.

BACKGROUND: The literature shows the beneficial effects of low-intensity ultrasound therapy on the healing process of several biological tissues. OBJECTIVE: To evaluate the effects of continuous ultrasound (CUS) on the hematological dynamics of an acute inflammatory process in iatrogenic muscle injuries. METHODS: Sixteen Wistar rats (350 to 400g) were divided into a control group (CG=8) and an experimental group (G1=8). The rats were submitted to a surgical incision on the lateral aspect of the right hind limb, in which the biceps femoris muscle was transversally injured. The CUS (1MHz) was applied to the injury site at an intensity of 0.4W/cm², for three minutes, in 1, 8 and 24 hour after the injury. At these times, blood was drawn by venipuncture of the retroorbital plexus, for analysis of red and white blood cells. RESULTS: The CUS reduced erythrocytes in 8 percent at the first blood collection (9.9±0.1 versus 7.8±0.1; x10(5)/mm³; p<0.001); it doubled the number of segmented neutrophils at the second collection (3,166.8±161.4 versus 6,426.2±306.0; x10³/mm³; p=0.008) and the eosinophils at the third collection (2,883.6±99.0 versus 4,714.4±275.2; x10³/mm³; p=0.011), in relation to the CG. No differences between the groups were seen with regard to hematocrit, total leukocytes, rod neutrophils, monocytes or lymphocytes at the three times studied. CONCLUSIONS: Application of CUS for acute treatment of muscle injuries is contraindicated under this condition, because it promotes reductions in erythrocytes and increases in segmented neutrophils and eosinophils, thus favoring hemorrhage and increasing inflammatory process.

Hemodialysis improves endothelial venous function in end-stage renal disease

The objective of the present study was to determine the acute effect of hemodialysis on endothelial venous function and oxidative stress. We studied 9 patients with end-stage renal disease (ESRD), 36.8 ± 3.0 years old, arterial pressure 133.8 ± 6.8/80.0 ± 5.0 mmHg, time on dialysis 55.0 ± 16.6 months, immediately before and after a hemodialysis session, and 10 healthy controls matched for age and gender. Endothelial function was assessed by the dorsal hand vein technique using graded local infusion of acetylcholine (endothelium-dependent venodilation, EDV) and sodium nitroprusside (endothelium-independent venodilation). Oxidative stress was evaluated by measuring protein oxidative damage (carbonyls) and antioxidant defense (total radical trapping antioxidant potential - TRAP) in blood samples. All patients were receiving recombinant human erythropoietin for at least 3 months and were not taking nitrates or a-receptor antagonists. EDV was significantly lower in ESRD patients before hemodialysis (65.6 ± 10.5) vs controls (109.6 ± 10.8; P = 0.010) and after hemodialysis (106.6 ± 15.7; P = 0.045). Endothelium-independent venodilation was similar in all comparisons performed. The hemodialysis session significantly decreased TRAP (402.0 ± 53.5 vs 157.1 ± 28.3 U Trolox/µL plasma; P = 0.001). There was no difference in protein damage comparing ESRD patients before and after hemodialysis. The magnitude of change in the EDV was correlated negatively with the magnitude of change in TRAP (r = -0.70; P = 0.037). These results suggest that a hemodialysis session improves endothelial venous function, in association with an antioxidant effect.