Elke Vinck

Increased fibroblast proliferation induced by light emitting diode and low power laser irradiation

AbstractBackground and Objective: As Light Emitting Diode (LED) devices are commercially introduced as an alternative for Low Level Laser (LLL) Therapy, the ability of LED in influencing wound healing processes at cellular level was examined. Study Design/Materials and Methods: Cultured fibroblasts were treated in a controlled, randomized manner, during three consecutive days, either with an infrared LLL or with a LED light source emitting several wavelengths (950 nm, 660 nm and 570 nm) and respective power outputs. Treatment duration varied in relation to varying surface energy densities (radiant exposures). Results: Statistical analysis revealed a higher rate of proliferation (p ≤ 0.001) in all irradiated cultures in comparison with the controls. Green light yielded a significantly higher number of cells, than red (p ≤ 0.001) and infrared LED light (p ≤ 0.001) and than the cultures irradiated with the LLL (p ≤ 0.001); the red probe provided a higher increase (p ≤ 0.001) than the infrared LED probe and than the LLL source. Conclusion: LED and LLL irradiation resulted in an increased fibroblast proliferation in vitro. This study therefore postulates possible stimulatory effects on wound healing in vivo at the applied dosimetric parameters.

Extrinsic risk factors for compromised blood flow in the vertebral artery: anatomical observations of the transverse foramina from C3 to C7

The vertebral artery (VA) is often involved in the occurrence of complications after spinal manipulative therapy. Due to osteophytes compressing the VA anteriorly from the uncinate process or posteriorly from the facet complex, the VAs are susceptible to trauma in the transverse foramina. Such altered anatomical configurations are of major clinical significance, as spinal manipulations may result in dissection of the VA with serious consequences for the blood supply to the vertebrobasilar region. The purpose of this study is to describe numerous structural features of the third to seventh cervical vertebrae in order to contribute to the understanding of pathological conditions related to the VA. The minimal and maximal diameter of 111 transverse foramina in dry cervical vertebrae were studied. The presence of osteophytes and their influence on the VA were evaluated at the vertebral body and at the superior and inferior articular facets. The diameter of the transverse foramina increased from C3 to C6, while the transverse foramina of C7 had the smallest diameter. At all levels the mean dimensions of the left foramina were greater than those of the right side. Osteophytes from the uncinate process of C5 and C6 vertebrae were found in over 60% of dry vertebrae. Osteophytes from the zygapophyseal joints were more frequent at C3 and C4 vertebrae. About half of the osteophytes of the uncinate and of the superior articular process partially covered the transverse foramina. This was less common with those of the inferior articular facets. Osteophytes covering the transverse foramen force the VAs to meander around these obstructions, causing narrowing through external compression and are potential sites of trauma to the VAs potentially even leading to dissection. We strongly advocate that screening protocols for vertebrobasilar insufficiency (VBI) be used prior to any manipulation of the cervical spine and should include not only extension and rotation but any starting position from which the planned manipulation will be performed.

Atherosclerosis in the vertebral artery: an intrinsic risk factor in the use of spinal manipulation?

The presence of atherosclerotic plaques and their influence on the vertebral artery is of clinical importance within the scope of spinal manipulation. Manipulation may stimulate the development of atherosclerotic plaques, could detach an embolus with ensuing infarction, injure the endothelium or may directly cause a dissection in the presence of atherosclerotic plaques. In order to identify the sites and frequency of atherosclerotic plaques and to determine its relation to the tortuous course of the vertebral artery, a cadaveric study was performed. The vertebral arteries of 57 human cadavers were studied. The vertebral artery was virtually divided into four segments: the pre-vertebral (V1), the vertebral (V2), the atlanto-axial (V3), and the intracranial segment (V4). Abnormalities in the origin and course of the vertebral artery were noted, along with any associated osseous, or cartilaginous anomalies in the neck. After dissection, the artery was opened and macroscopically screened for the presence of atherosclerotic plaques. In 22.8% of the cases, no atherosclerotic plaques were present. In 35.1% of the cases, the atherosclerotic plaques were unilateral, of which 60.0% was on the left side, 40.0% on the right side, and in 42.1%, the occurrence was bilateral. Atherosclerotic plaques were significantly more present in the V3 segment than in the V1 (0.007) and V2 segment (0.049). In the V1 (P=0.008) and V2 segment (P=0.002), there was a correlation between a tortuous course of the vessel and the occurrence of atherosclerotic plaques. In individuals with marked atherosclerotic disease, stretching and compression effects of rotational manipulative techniques on atherosclerotic vessels impose a further risk factor for vertebrobasilar insufficiency. As direct evidence of atherosclerotic plaques are rarely available, therapists should avoid manipulative techniques at all levels of the cervical spine in the presence of any indirect sign of atherosclerotic disease or in the presence of calcified arterial walls or tortuosities of the vessels visible on routinely available X-ray images of the cervical or thoracic spine. It is strongly recommended, that if any doubt exists about the nature of a clinical presentation, vigorous manual procedures should be avoided until either the diagnosis is definitive or gentle manual therapy has proven effective.

Do infrared light-emitting diodes have a stimulatory effect on wound healing? From an in-vitro trial to patient treatment

Variable effects of different forms of light therapy on wound healing have been reported. This preliminary study covers the efficacy of infrared light emitting diodes (LED) in this domain. Cultured embryonic chicken fibroblasts were treated in a controlled, radomised manner. LED irradiation was performed three consecutive days with a wavelength of 950 nm and a power output of 160 mW, at 0,6 cm distance from the fibroblasts. Each treatment lasted 6 minutes, resulting in a surface energy denstiy of 3,2 J/cm2. The results indicated that LED treatment does not influence fibroblast proliferation at the applied energy density and irradiation frequency (p=0,474). Meanwhile the effects of LED on wound healing in vivo were studied by treating a surgical incision (6 cm) on the lateral side of the right foot in a male patient. The treatment started after 13 days, when initial stitches were being removed. The same parameters as in the in vitro study were used but the treatment was performed five times. The healing could only be evaluated clinically, the irradiated area (2,6 cm) showed a more appropriate contraction, less discoloration and a less hypertrophic scar than the control area (3,4 cm). The used parameters failed to demonstrate any biological effect of LED irradiation in vitro, although the case study on the other hand illustrated a beneficial effect.

Is photodynamic therapy an appropriate treatment of feline superficial squamous cell carcinomas? Two case studies in small animal practice

Oncological research and cancer treatment are more common in human medicine than in veterinary medicine. Nevertheless the latest decennium chemotherapy, radiotherapy and surgery also figure largely in the cancer treatment of pets. For this matter, the present study tried to explore the applicability of Photodynamic Therapy (PDT) as a proper and advantageous alternative for those treatments. PDT using topical 5-aminolaevulinic acid (5-ALA) cream was applied on superficial squamous cell carcinomas (SCC) at the nasal planum of two cats. Five hours after the cream was applied, the photosensitizing agent was removed and the sensitized area was irradiated with a red Light Emitting Diode (LED) contrivance with a wavelength of 660 nm. LED irradiation was administrated during 20 minutes, at a power output of 80 mW, with an energy density outcome of 38 J/cm2. The day after ths irradiation, the tumor area became erythematous and somewhat oedematous. After two days a scab occurred. Long-term post treatment observation showed complete removal of the malign cells related with regain of normal skin structure after three weeks. Follow-up period of one year for the first case and of two months for the second case revealed no recurrence. These promising results indicate that PDT is a possible alternative method to treat superficial skin tumors. Especially when taking into account that chemotherapy and radiotherapy are time-consuming treatments and that surgery (complete removal of the nasal planum) is not an esthetical solution.

The role of SPECT imaging in the diagnosis of vertebrobasilar insufficiency.

Vertigo is a clinical dilemma with many causes. Vertebrobasilar insufficiency (VBI) is a well-known cause of vertigo with or without accompanying neurological symptoms. It is defined as a group of disorders in which blood supply to the back of the brain via the two vertebral arteries and the basilar artery is disrupted [1]. Reduced blood flow in these vessels will give rise to a variety of signs and symptoms according to the site of ischaemia, of which the most important symptoms are dizziness/vertigo, diplopia, dysarthria, dysphagia, drop attacks and/or nausea.

Proliferative effect of green light emitting diode irradiation on chicken fibroblasts in hyperglycaemic circumstances: a preliminary in vitro study

A reduced mortality due to hyperglycaemia was noted since the development of insulin treatment for type I diabetes and various oral hypoglycaemic agents for type II diabetes. Nevertheless the chronic metabolic disorder, Diabetes Mellitus, remains an important cause of morbidity and mortality due to a series of common secondary metabolic complications. Patients with diabetes have an increased tendency to develop infections of the skin. Healing of skin lesions in diabetics evolves often relatively slow and the lesions tend to be more severe than in non-diabetics. Endeavouring to accelerate the healing process of skin lesions in diabetic patients, this preliminary in vitro study investigates the efficacy of green Light Emitting Diode (LED) irradiation on fibroblast proliferation of cells in hyperglycaemic circumstances. In an attempt to imitate the diabetic environment, embryonic chicken fibroblasts were cultured in hyperglycaemic medium (30.000mg Glucose per litre Hanks Medium). LED irradiation was performed three consecutive days with a wavelength of 540 nm and a power output of 10 mW, at 0,6 cm distance from the fibroblasts. Each treatment lasted 3 minutes, resulting in a surface energy density of 0,2 J/cm2. Statistical analysis revealed that LED irradiation at the applied parameters induced a higher rate of proliferation in hyperglycaemic circumstances after irradiation than in the same circumstances without irradiation. Regarding these results the effectiveness of green LED irradiation on cells in hyperglycaemic circumstances is proven. To ensure the effectiveness and to evaluate the value of LED irradiation in vivo, further research is required.

Proliferation of chicken fibroblasts induced by light-emitting diodes: a comparative trial for different wavelengths

The effectiveness and applicability of a variety of light sources, in the treatment of wounds has thoroughly been investigated, in vitro as well as in vivo. The current commercial availability of Light Emitting Diode (LED) sources therefore also invites research to explore the effect of low power infrared, red and green light on wound healing, e.g. by means of fibroblast proliferation. Therefore a controlled and randomized study on cultured embryonic chicken fibroblasts was conducted. The fibroblasts were irradiated during three consecutive days, at several wavelengths (950 nm, 660 nm and 570 nm) and a respective power output of 160 mW, 80 mW or 10 mW. Treatment duration varied from 1 minute to 3 minutes to obtain a surface energy density of 0.9 J/cm2 (infrared and red light) or 0.2 J/cm2 (green light). Statistical analysis revealed that LED irradiation for all three wavelengths induced a higher rate of proliferation in comparison of the control group. This difference was statistically significant (p < .001). With regard to the amount of proliferation the green probe yielded a significantly higher number of cells, than the red (p < .001) an the infrared probe (p < .001). Furthermore, the red probe provided a higher increase (p < .001) than the IR probe. LED irradiation results in an increased fibroblast proliferation in vitro. This outcome postulates beneficial stimulatory effects of LED at the applied wavelength, energy density and power output on wound healing in vivo. Further investigation is necessary to examine this hypothesis.