The impact of hyperbaric oxygen therapy on late irradiation injury in oral microcirculation.

BACKGROUND: Late side effects of radiotherapy in patients with head and neck cancer (HNCPs) result in decreased tissue vascularity, a compromised healing capacity and spontaneous breakdown of tissue. The aim of this study was to examine the in vivo effect of hyperbaric oxygen therapy (HBOT) on the microcirculation in irradiated oral tissue. METHODS: Using a handheld microscope, the effect of HBOT on oral mucosal microcirculation parameters was measured in 34 previously irradiated HNCPs prior to HBOT and at 4 weeks and 6 months posttreatment. RESULTS: A significant increase in mean buccal vessel density and decrease in buccal vessel diameter was found 6 months after HBOT compared to baseline, 22 ± 11 versus 25 ± 7 cpll/mm2 (p < 0.05) and 20 ± 4 versus 16 ± 5 µm (p < 0.05), respectively. CONCLUSION: Our results indicate that oral microcirculation histopathology associated with irradiation is able to respond to HBOT by redirecting oral microcirculation parameters towards values consistent with healthy tissue.

Microvascular Effects of Pulsed Dye Laser in Combination With Oxymetazoline.

BACKGROUND AND OBJECTIVE: Oxymetazoline, an α-1A agonist, is approved by the United States Food and Drug Administration (FDA) for treatment of persistent facial erythema associated with rosacea and induces vasoconstriction by interacting with α receptors. The objective of our study was to study the microvascular effects of oxymetazoline and pulsed dye laser (PDL). MATERIALS AND METHODS: A dorsal window chamber was surgically installed on 20 mice. Each animal was assigned to one of four experimental groups: saline alone, oxymetazoline alone (10 µl applied once daily × 7 days), saline + PDL (saline applied 5 minutes before PDL irradiation [10 mm spot, 1.5 ms pulse duration, 7 J/cm2 delivered to epidermis]), or oxymetazoline + PDL (10 µl oxymetazoline applied 5 minutes before PDL and then once daily × 7 days). Brightfield and laser speckle imaging were performed for 7 days to monitor vascular architectural and functional changes. RESULTS: We observed persistent blood flow in all of the saline-only and oxymetazoline-only experiments. A higher rate of vascular shutdown was observed with oxymetazoline + PDL (66.7%) compared with saline + PDL alone (16.7%). Oxymetazoline application increased venule diameter at 5 minutes post-application and decreased both arteriole and venule diameters at 60 minutes post-application. CONCLUSION: The combination protocol of oxymetazoline + PDL induces persistent vascular shutdown observed 7 days after irradiation. This result may be associated with the acute vascular effects of oxymetazoline. Oxymetazoline + PDL should be evaluated as a treatment for cutaneous vascular disease, including rosacea and port wine birthmarks. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Besides Photothermal Effects, Low-Level CO2 Laser Irradiation Can Potentiate Skin Microcirculation Through Photobiomodulation Mechanisms.

Background: Improvement of microcirculation is one of the important mechanisms of low-level laser therapy (LLLT) to treat some diseases such as wound healing. Most previous studies have been carried out with multiple lasers other than the 10,600-nm CO2 laser. Recently, the CO2 laser has been used not only as a tool for excision of soft tissues but also for therapeutic applications. Objective: To study whether low-level CO2 laser irradiation can influence microcirculation and further explore the underlying mechanisms. Methods: Seventy-milliwatt (70-mW) CO2 lasers irradiated the forearms of 12 participants and skin blood perfusion (SkBP) was measured with a laser speckle imager. The thermal effect of irradiation was evaluated by measuring the irradiated skin in vivo and the exposed cell suspensions in vitro. Extracellular adenosine triphosphate (eATP) of the human mast cell line (HMC-1) is assessed by luciferin-luciferase assay to explore the potential mechanisms. Results: Irradiation caused dose-dependent increase in SkBP. At a medium dose of 262 J/cm2, SkBP reached its maximum value at 195.8% ± 18.6% of the baseline (n = 12, p < 0.01). Such laser irradiation had a mild thermal effect, heating local skin temperature (SkT) by 6.1°C ± 0.3°C (n = 10) and warming cell suspensions by 4.5°C ± 0.8°C (n = 6). Irradiation dose-dependently lowered eATP levels of HMC-1 cells in vitro. At a medium dose of 262 J/cm2, eATP levels declined to the minimum at 74.8% ± 5.5% of the baseline (n = 12, p < 0.01). This downregulation effect could be significantly inhibited by 100-µM ARL67156, a nonspecific ecto-ATPase inhibitor. On the contrary, heating itself slightly raised the level of eATP. Conclusions: Low-level CO2 laser irradiation can improve microcirculation. Besides the thermal effect, regulation of extravascular eATP by the photobiomodulation mechanism may be involved. This implies that CO2 lasers might be used in LLLT.

The effect of LED on blood microcirculation during chronic wound healing in diabetic and non-diabetic patients-a prospective, double-blind randomized study.

Chronic wounds, especially in diabetic patients, represent a challenging health issue. Since standard treatment protocols often do not provide satisfactory results, additional treatment methods-like phototherapy using low-level light therapy-are being investigated. The aim of our study was to evaluate the effect of phototherapy with light-emitting diodes on chronic wound treatment in diabetic and non-diabetic patients. Since a sufficient blood supply is mandatory for wound healing, the evaluation of microcirculation in the healthy skin at a wound's edge was the main outcome measure. Forty non-diabetic patients and 39 diabetics with lower limb chronic wounds who were referred to the University Medical Center Ljubljana between October 2012 and June 2014 were randomized to the treated and control groups. The treated group received phototherapy with LED 2.4 J/cm2 (wavelengths 625, 660, 850 nm) three times a week for 8 weeks, and the control group received phototherapy with broadband 580-900 nm and power density 0.72 J/cm2. Microcirculation was measured using laser Doppler. A significant increase in blood flow was noted in the treated group of diabetic and non-diabetic patients (p = 0.040 and p = 0.033), while there was no difference in the control groups. Additional Falanga wound bed score evaluation showed a significant improvement in both treated groups as compared to the control group. According to our results, phototherapy with LED was shown to be an effective additional treatment method for chronic wounds in diabetic and non-diabetic patients.

Effect of Prewarming during Induction of Anesthesia on Microvascular Reactivity in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery: A Randomized Clinical Trial.

BACKGROUND: General anesthesia may induce inadvertent hypothermia and this may be related to perioperative cardiovascular complications. Microvascular reactivity, measured by the recovery slope during a vascular occlusion test, is decreased during surgery and is also related to postoperative clinical outcomes. We hypothesized that microvascular changes during surgery may be related to intraoperative hypothermia. To evaluate this, we conducted a randomized study in patients undergoing off-pump coronary artery bypass surgery, in which the effect of prewarming on microvascular reactivity was evaluated. METHODS: Patients scheduled for off-pump coronary artery bypass surgery were screened. Enrolled patients were randomized to the prewarming group to receive forced-air warming during induction of anesthesia or to the control group. Measurement of core and skin temperatures and vascular occlusion test were conducted before anesthesia induction, 1, 2, and 3 h after induction, and at the end of surgery. RESULTS: In total, 40 patients were enrolled and finished the study (n = 20 in the prewarming group and n = 20 in the control group). During the first 3 h of anesthesia, core temperature was higher in the prewarming group than the control group (p < 0.001). The number of patients developing hypothermia was lower in the prewarming group than the control group (4/20 vs. 13/20, p = 0.004). However, tissue oxygen saturation and changes in recovery slope following a vascular occlusion test at 3 h after anesthesia induction did not differ between the groups. There was no difference in clinical outcome, including perioperative transfusion, wound infection, or hospital stay, between the groups. CONCLUSIONS: Prewarming during induction of anesthesia decreased intraoperative hypothermia, but did not reduce the deterioration in microvascular reactivity in patients undergoing off-pump coronary artery bypass surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT02186210.

Effects of pulsed electromagnetic fields on peripheral blood circulation in people with diabetes: A randomized controlled trial.

Cutaneous blood flow provides nourishment that plays an essential role in maintaining skin health. We examined the effects of pulsed electromagnetic fields (PEMFs) on cutaneous circulation of dorsal feet. Twenty-two patients with diabetes mellitus (DM) and 21 healthy control subjects were randomly allocated to receive either PEMFs or sham PEMFs (0.5 mT, 12 Hz, 30 min). Blood flow velocity and diameter of the small vein were examined by using ultrasound biomicroscopy; also, microcirculation at skin over the base of the 1st metatarsal bone (Flux1) and distal 1st phalange (Flux2) was measured by laser Doppler flowmetry before and after intervention. Results indicated that PEMFs produced significantly greater changes in blood flow velocity of the smallest observable vein than did sham PEMFs (both P < 0.05) in both types of subjects. However, no significant difference was found in changes of vein diameter, nor in Flux1 and Flux2, between PEMFs and sham PEMFs groups in subjects with or without DM. We hypothesized that PEMFs would increase blood flow velocity of the smallest observable vein in people with or without DM. Bioelectromagnetics. 37:290-297, 2016. © 2016 Wiley Periodicals, Inc.

[The influence of the low-frequency laser radiation on microcirculatory disorders in the patients presenting with chronic viral hepatitis].

AIM: The objective of the present study was to elucidate the character of microcirculatory disorders in the patients presenting with chronic viral hepatitis and to evaluate the possibilities for the correction of the associated disorders with the use of laser irradiation. Material and methods. All the patients were divided into three groups. Group 1 was comprised of 30 patients who were treated by means of traditional medicamental therapy alone; they served as controls. Group 2 consisted of 45 patients treated by intravenous laser irradiation in addition to traditional medicamental therapy. The patients of group 3 (n=45) received a course of laser skin treatment. The state of microcirculation was assessed by the laser Doppler flowmetry (LDF) technique with the help of a LAKK-02 apparatus (<> Research and Manufacturing Complex, Moscow, Russia). RESULTS: The study has demonstrated heterogeneity of the types of microcirculation with the statistically significant increase in the frequency of its pathological cases. All the patients treated with the use of low-intensity laser therapy exhibited a significant improvement of the blood flow characteristics regardless of the initial hemodynamic type of microcirculation. CONCLUSION: It is concluded that the application of laser irradiation as a component of the combined treatment of the patients presenting with chronic viral hepatitis facilitates correction of microcirculatory disorders.

Effects of Therapeutic Physical Agents on Achilles Tendon Microcirculation.

STUDY DESIGN: Controlled laboratory study. OBJECTIVES: To measure Achilles tendon microcirculation (total hemoglobin [THb] and oxygen saturation [StO2]) before and after the application of a physical agent in asymptomatic participants, and to compare differences between application location and physical agent dosage. BACKGROUND: Tendon microcirculation can be altered by superficial heating or cryotherapy. METHODS: Fifty-one healthy adults (median age, 22 years; range, 20-34 years) were recruited and randomly assigned into 1 of 4 groups. Participants in each group received an intervention consisting of 1 of the following 4 physical agents: ultrasound (n = 12), interferential current (n = 14), low-level laser (n = 11), or vibration massage (n = 14). In each group, the selected intervention was applied at 2 different doses (ultrasound, 0.8 or 1.2 W/cm(2); laser, 5.4 or 18 J) or target locations (vibration and electrostimulation, calf muscle or Achilles tendon). For each participant, each dose or target location was randomly applied to 1 randomly selected lower leg (each leg receiving only 1 of the 2 options). RESULTS: The StO2 values significantly increased after ultrasound at both doses (P<.008), and the THb value significantly increased for the higher dose only (P<.008). Both THb and StO2 values also significantly increased in response to vibration massage targeting the Achilles tendon (P<.008), and these values were greater than those resulting from the vibration massage applied to the calf muscle (P = .003 and .002, respectively). No significant THb and StO2 differences were found after the application of interferential current or low-level laser. CONCLUSION: Tendon microcirculation increases after ultrasound and vibration massage intervention concentrated on the Achilles tendon. These modalities may be considered for the purpose of temporarily increasing microcirculation in the tendon.

Effect of hyperbaric oxygen treatment on oxygen tension and vascular capacity in irradiated skin and mucosa.

The aim of this study was to evaluate the effect of hyperbaric oxygen therapy (HBOT) on vascular function and tissue oxygenation in irradiated facial skin and gingival mucosa. Twenty-two patients, aged 51-90 years, were randomly allocated to a treatment or control group. All had a history of radiotherapy (50-70 Gy) to the orofacial region 2-20 years previously. Skin and mucosal perfusion were recorded with laser Doppler flowmetry (LDF). Tissue oxygenation was recorded by transcutaneous oximetry (TcPO(2)). Measurements were taken before HBOT and 3 and 6 months after a mean of 28 HBOT sessions (partial pressure of oxygen of 240 kPa for 90 min). For control subjects, measurements were taken on two occasions 6 months apart. After HBOT, blood flow in mucosa and skin after heat provocation increased significantly (P < 0.05). TcPO(2) increased significantly in the irradiated cheek (P < 0.05), but not at reference points outside the field of radiation. There were no differences between the 3- and 6-month follow-ups. In the control group, no significant changes in LDF or TcPO(2) were observed. It is concluded that oxygenation and vascular capacity in irradiated facial skin and gingival mucosa are increased by HBOT. The effects persist for at least 6 months.

[Molecular-cellular mechanisms of light radiation and weak magnetic fields on the blood status and microcirculation system (at therapeutic doses) with using modern magnetolaser equipment (review of the literature)].

This review covers the molecular-cellular mechanisms of therapeutic action of light and magnetic field on blood components, blood vessels and the microcirculation system. Noted the role of the magnetic field as a trigger of vasodilation/vasoconstriction, depending on the initial vascular tone. Discussed the importance of NO-dependent effects of magnetic field on the microcirculatory response and angiogenesis.

Análise termográfica da região de masseter após irradiação com laser ou LED - estudo clínico / Infrared thermal analysis of the masseter region after irradiation with led low level laser - clinical study

Introdução: Segundo alguns estudos, a terapia com laser de baixa intensidade pode promover modificações na microcirculação periférica. Objetivo: Busca-se, por meio desse estudo analisar a temperatura facial após ser submetida a irradiação com laser e LED. Métodos: Nove voluntários, com idade média de 28 anos, receberam radiação com laser (660 nm, 30 mW, 7,5 J/cm2, 10 segundos) ou LED (640±20 nm, 30 mW, 4 J/cm2, 20 segundos). Resultados: O lado contralateral (controle) das terapias não apresentou diferenças significativas pós-irradiação. Conclusão: Pode-se sugerir que, nas doses testadas, não existiram efeitos sistêmicos sobre a temperatura superficial pós-irradiação. As terapias com os parâmetros utilizados (teste) para o laser não promoveram diferença significativa na temperatura superficial local, no entanto, para o LED pode apresentar efeito modulador da temperatura periférica em até 5 minutos pós-irradiação, podendo auxiliar no pós- operatório, porém necessita de mais estudos.

Introduction: According to some studies, therapy with low-intensity laser can promote changes in peripheral microcirculation. Objective: The aim is, through this study to analyze the facial temperature after being subjected to irradiation with laser and LED. Methods: Nine volunteers, mean age 28 years, received radiation laser (660 nm, 30 mW, 7.5 J/cm2, 10 seconds) or LED (640 ± 20 nm, 30 mW, 4 J/cm2, 20 seconds). Results: The contralateral (control) of therapy showed no significant differences in post-irradiation. Conclusion: The results suggest that, at the dose tested, there were no systemic effects on the surface temperature post-irradiation. Therapies with the parameters used (test) for the laser did not cause significant difference in local surface temperature, however, the LED may have a modulatory effect of peripheral temperature within 5 minutes after irradiation, which could aid in the postoperative period, but requires further studies.

Noninvasive cutaneous blood flow as a response predictor for visible light therapy on segmental vitiligo: a prospective pilot study.

BACKGROUND: Visible light is a treatment option for segmental vitiligo (SV), and visible light-induced repigmentation is associated with normalization of sympathetic dysfunction. Currently, it is difficult to predict individual patients' response to visible light therapy. OBJECTIVES: To test whether cutaneous blood flow can serve as a response predictor for visible light on treating SV. METHODS: Fourteen patients with SV were recruited in this prospective pilot study. Laser Doppler flowmetry was used to evaluate the cutaneous blood flow over SV lesions and contralateral normal skin. The pretreatment blood flow evaluation consisted of two stages: stage 1, following cold stress without prior visible light irradiation, and stage 2, following cold stress with prior visible light irradiation. Subsequently, the patients received regular visible light treatment for 3months, and a comparison of the pretreatment blood flow patterns between the visible light responding and nonresponding groups was carried out at the end of the study period. RESULTS: The SV lesions showed different blood flow profiles as compared with the contralateral normal skin. At the end of the 3-month study period, seven (50%) patients showed clinical repigmentation of >25%. The visible light responding group showed a more consistent occurrence of increased blood flow after stage 2 of the pretreatment evaluation while the nonresponding counterpart showed no significant changes. CONCLUSIONS: Normalization of sympathetic dysfunction may account for the efficacy of visible light in treating SV. Evaluation of cutaneous blood flow with and without prior visible light irradiation on cold-stressed SV lesions may serve as a treatment response predictor.

[Study of alternating magnetic field influence on rates of rehabilitation of patients after dental implantation].

New way of using alternating magnetic field is described. Basic functional description of new treatment and diagnostic offered (patents of RF No75294 and 75314), which included digital plethysmograph and regulation of angiotonic microcirculation channel device. Comparative estimation of clinical and functional indiced of regional blood flow of patients in the main group and in the control group showed a positive correlation. Expressed influence of alternating magnetic field on frequency of oscillations pulse vessels microcircution channel and acceleration of leveling disorder of blood circulation in tissue after surgical treatment was proved.

[Effects of low-level laser irradiation on rat mesenteric microcirculatory disturbance during early stage of endotoxemia].

OBJECTIVE: To observe the effects of low-level laser irradiation on mesenteric microcirculation of rats in vivo in the early stage of endotoxemia (ETM). METHODS: The experimental model of ETM was reproduced by injection of lipopolysaccharide (LPS). Sixty healthy male Sprague-Dawley (SD) rats were divided into three groups used random number table: control group, LPS group and low-level laser irradiation group, each group included 20 rats which were subdivided into four temporal subgroups (1, 2, 4, 6 hours, respectively). In low-level laser irradiation group, the rats were irradiated by type SLT semiconductor laser (650 nm, 5 mW) on unilateral femoral artery and vein, and blood vessel of the ear concurrently for 30 minutes. The interference course was vertical irradiation taken at 30 minutes after the injection of LPS. At 1, 2, 4, 6 hours after the injection of LPS, changes in mesenteric microcirculation and microcirculatory blood flow were recorded with the laser Doppler flowmeter, the velocity of red blood cells in venules was observed, and the number of open capillaries and adherent leukocytes were recorded. RESULTS: The blood flow velocity (mm/s) of the mesenteric microcirculation in LPS group was accelerated at 1 hour and 2 hours after LPS injection (1 hour: 0.190+/-0.007 vs. 0.174+/-0.009, 2 hours: 0.200+/-0.010 vs. 0.172+/-0.015, both P<0.05, respectively), but decelerated at 6 hours (0.116+/-0.015 vs. 0.164+/-0.011, P<0.05). The blood flow volume in the mesenteric vessels and the number of open capillaries did not show any significant change at that time. Significant increase in number of adherent leukocytes was observed at 2, 4, 6 hours after injury (2 hours: 2.60+/-1.14 vs. 0.40+/-0.55, 4 hours: 5.40+/-0.89 vs. 0.40+/-0.55, 6 hours : 5.40+/-1.52 vs. 0.60+/-0.90, all P<0.05, respectively). The state of blood flow in the microcirculation became abnormal. After irradiated with laser in low dose, the blood flow velocity was smooth and stable (mm/s, 1 hour: 0.174+/-0.011, 2 hours: 0.180+/-0.023, 4 hours: 0.168+/-0.013, 6 hours: 0.162+/-0.023), and the number of adherent leukocytes was reduced significantly at 4 hours and 6 hours than that in LPS group (4 hours: 2.00+/-0.71 vs. 5.40+/-0.89, 6 hours: 2.60+/-1.52 vs. 5.40+/-1.52, both P<0.05) and the microcirculatory flow state was improved obviously. CONCLUSION: Low-level laser irradiation may ameliorate the local mesenteric microcirculation, alleviate the microcirculatory disorder in early stage of ETM.

[Use of alternating magnetic field with the frequency of spontaneous local vessels oscillation for rehabilitation of patients after dental implantation].

New software-hardware system for diagnostic and treatment (RF patents: number 75294, 2008 and number 75314, 2008) allowing to use the technique of microcirculatory bed regional pulse vessels control (RF patent number 2383369, 2008) for optimization of patients' rehabilitation process after dental implantation operation. It was shown the normalizing action of alternating magnetic field with the frequency of spontaneous local vessels oscillation by comparison of regional blood flow indices.

Effect of low-level laser therapy on malondialdehyde concentration in random cutaneous flap viability.

OBJECTIVE: The aim of this study was to assess the effects of 830 and 670 nm laser on malondialdehyde (MDA) concentration in random skin-flap survival. BACKGROUND DATA: Low-level laser therapy (LLLT) has been reported to be successful in stimulating the formation of new blood vessels and activating superoxide-dismutase delivery, thus helping the inhibition of free-radical action and consequently reducing necrosis. MATERIALS AND METHODS: Thirty Wistar rats were used and divided into three groups, with 10 rats in each one. A random skin flap was raised on the dorsum of each animal. Group 1 was the control group; group 2 received 830 nm laser radiation; and group 3 was submitted to 670 nm laser radiation. The animals underwent laser therapy with 36 J/cm(2) energy density immediately after surgery and on the 4 days subsequent to surgery. The application site of the laser radiation was 1 point, 2.5 cm from the flap's cranial base. The percentage of the skin-flap necrosis area was calculated 7 days postoperative using the paper-template method, and a skin sample was collected immediately after as a way of determining the MDA concentration. RESULTS: Statistically significant differences were found between the necrosis percentages, with higher values seen in group 1 compared with groups 2 and 3. Groups 2 and 3 did not present statistically significant differences (p > 0.05). Group 3 had a lower concentration of MDA values compared to the control group (p < 0.05). CONCLUSION: LLLT was effective in increasing the random skin-flap viability in rats, and the 670 nm laser was efficient in reducing the MDA concentration.

[Types of microcirculation and laser therapy in chronic pancreatitis].

The aim of the study was to evaluate effect of low-intensity laser therapy (LILT) on systemic circulation in patients with chronic pancreatitis (CP) in the phase of exacerbation. 65 patients aged 36-77 years were divided into study (n = 20) and control (n = 45) groups. In addition, 30 healthy subjects were examined. Patients of the study group received drug therapy combined with intravenous blood or skin laser irradiation. Controls were treated with medicinal preparations alone. CP was diagnosed based on characteristic pain syndrome, compromised secretory function of the pancreas, results of laboratory and instrumental analysis. Microcirculation was studied by laser Doppler flowmetry with a LAKK-02 apparatus (Lazma, Russia). CP patients had heterogeneous microcirculation with a significantly increased frequency of its pathologic types (spastic, hyperemic, spastic-congestive). Major characteristics of microcirculation were significantly different from those in healthy subjects. Combination of drug therapy and LILT substantially improved microcirculation regardless of its hemodynamic type.

The effect of low-level laser in knee osteoarthritis: a double-blind, randomized, placebo-controlled trial.

INTRODUCTION: Low-level laser therapy (LLLT) is thought to have an analgesic effect as well as a biomodulatory effect on microcirculation. This study was designed to examine the pain-relieving effect of LLLT and possible microcirculatory changes measured by thermography in patients with knee osteoarthritis (KOA). MATERIALS AND METHODS: Patients with mild or moderate KOA were randomized to receive either LLLT or placebo LLLT. Treatments were delivered twice a week over a period of 4 wk with a diode laser (wavelength 830 nm, continuous wave, power 50 mW) in skin contact at a dose of 6 J/point. The placebo control group was treated with an ineffective probe (power 0.5 mW) of the same appearance. Before examinations and immediately, 2 wk, and 2 mo after completing the therapy, thermography was performed (bilateral comparative thermograph by AGA infrared camera); joint flexion, circumference, and pressure sensitivity were measured; and the visual analogue scale was recorded. RESULTS: In the group treated with active LLLT, a significant improvement was found in pain (before treatment [BT]: 5.75; 2 mo after treatment : 1.18); circumference (BT: 40.45; AT: 39.86); pressure sensitivity (BT: 2.33; AT: 0.77); and flexion (BT: 105.83; AT: 122.94). In the placebo group, changes in joint flexion and pain were not significant. Thermographic measurements showed at least a 0.5 degrees C increase in temperature--and thus an improvement in circulation compared to the initial values. In the placebo group, these changes did not occur. CONCLUSION: Our results show that LLLT reduces pain in KOA and improves microcirculation in the irradiated area.

Frequency-modulated electromagnetic neural stimulation enhances cutaneous microvascular flow in patients with diabetic neuropathy.

AIM: The aim of this study was to investigate the effects of frequency modulated electromagnetic neural stimulation (FREMS), a recently developed safe and effective treatment of painful diabetic neuropathy, on cutaneous microvascular function. METHODS: Thirty-one patients with painful neuropathy were enrolled in a randomised, double-blind, crossover FREMS vs. placebo study; each received two series of 10 treatments of either FREMS or placebo in random sequence within no more than 3 weeks. Patients were studied at baseline, end of FREMS and placebo series, and after 4 months of follow-up. Cutaneous blood flow was measured by laser doppler flowmetry and partial tissue tension of oxygen (TcPO2) and carbonic anhydride (TcPCO2) by oxymetry at the lower extremities in basal resting conditions and as incremental response after thermal stimulation. RESULTS: Crossover analysis showed no consistent differences between FREMS and placebo. After 4-month follow-up, a 52% increase of cutaneous blood flow was observed in resting conditions (P=.0086 vs. baseline), while no differences were observed as incremental flow after warming; compared with baseline, no significant differences were observed for TcPO2 and TcPCO2, both in resting conditions and as incremental response to warm. CONCLUSION: These results indicate that 10 treatments with FREMS may induce an enhancement of microvascular blood flow measurable at 4 months of follow-up. The findings of this study will need to be confirmed in a larger, adequately powered study (ClinicalTrial.gov Id: NCT00337324).

Role of nitric oxide in the visible light-induced rapid increase of human skin microcirculation at the local and systemic level: I. diabetic patients.

OBJECTIVE: This study aimed to reveal the effects of polychromatic visible (pVIS) or pVIS + near IR (nIR) light similar to some components of solar light on skin microcirculation and microvascular response to the vasodilatators acetylcholine (ACh) and nitroglycerine (NG), in the extremities of patients with diabetic microangiopathy. BACKGROUND DATA: The mechanisms behind light-induced increases in microcirculation as well as extracellular effects of terrestrial pVIS and pVIS + nIR light remain unknown. MATERIALS AND METHODS: In 24 subjects with type 2 diabetes mellitus local microcirculation was measured in the skin of the foot before and after exposure to both types of light. In another 26 patients systemic microcirculation was studied in the back of the hand before and after exposure of the lumbar-sacral area to light energy. Two different types of light therapy were performed by using two devises: Q-light, which delivers pVIP (385-750 nm) and pVIS nIR light (385-1700 nm) with a power density of 40 mW/cm2, which is similar to summer sunlight at noon in Central Europe. RESULTS: At 2 min after irradiation (12 J/cm2) of the forefoot with pVIS or pVIS + nIR light, a rise in local blood flow volume (Qas) was observed, on average by 39% and 31%, respectively. The maximal effect (+41-47%) had developed in all patients at 30 min, and it then decreased and disappeared completely 24 h post-irradiation. We obtained similar results after irradiation of the sacral area in Qas of the skin of the hand. Both types of microcirculation also increased following a second exposure to the light sources. Enhancement of microcirculation was accompanied by a decrease in the microvascular response to ACh and NG solutions administered intracutaneously by iontophoresis. CONCLUSION: Both types of irradiation stimulated microcirculation at the local and systemic levels through a mechanism of enhancement of endothelium-dependent and endothelium-independent vasodilation, in which nitric oxide plays a major role.