Effect of 1440-nanometer neodymium:yttrium-aluminum-garnet laser irradiation on pain and neuropeptide reduction: a randomized prospective clinical trial.

INTRODUCTION: The purpose of this study was to investigate the efficacy of a 1440-nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser on relieving pain in relation to the levels of inflammatory cytokine and neuropeptides in the root canal exudates of teeth with persistent symptomatic apical periodontitis. METHODS: Forty teeth with persistent symptomatic apical periodontitis were randomly assigned to treatment groups: group L, intracanal irradiation of 1440-nm Nd:YAG laser with a 300-µm-diameter fiberoptic tip in addition to conventional root canal retreatment, and group C, conventional root canal re-treatment. The degrees of both spontaneous pain and the pain on percussion before and after treatment were recorded, and root canal exudate samples were collected to quantify the associated levels of substance P, calcitonin gene-related peptide (CGRP), and matrix metalloproteinase (MMP)-8 by immunoassay. RESULTS: All of the measured parameters were significantly reduced in group L (P < .05), whereas the level of pain on percussion, CGRP, and MMP-8 were significantly reduced in group C (P < .05). The 1440-nm Nd:YAG laser had significantly better effect on the relief of pain on percussion and the reduction of substance P, CGRP, and MMP-8 levels. The visual analog scale scores of perceived pain correlated with pain-related neuropeptides and inflammatory cytokine levels in root canal exudates. CONCLUSIONS: The 1440-nm Nd:YAG laser irradiation via fiberoptic tip to the teeth with persistent apical periodontitis provided promising consequences of pain and inflammation modulation.

[Adjuvant stereotactic low energy radiation therapy of exudative age-dependent macular degeneration (Oraya system)]. / Adjuvante stereotaktische niederenergetische Strahlentherapie bei exsudativer altersabhängiger Makuladegeneration (Oraya System).

With respect to the increasing number of patients and the risk and burden for patients caused by injections, a reduction in the number and frequency of injections with vascular endothelial growth factor (VEGF) inhibitors in exudative age-related macular degeneration (ARMD) is desirable. Stereotactic low-voltage x-ray irradiation seems to be a promising approach. For this purpose the Oraya system is available and has shown positive results in initial studies. Pending presentation of phase II and III study data this adjuvant irradiation should only be used in clinical trials.

Low-level laser therapy in different stages of rheumatoid arthritis: a histological study.

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease of unknown etiology. Treatment of RA is very complex, and in the past years, some studies have investigated the use of low-level laser therapy (LLLT) in treatment of RA. However, it remains unknown if LLLT can modulate early and late stages of RA. With this perspective in mind, we evaluated histological aspects of LLLT effects in different RA progression stages in the knee. It was performed a collagen-induced RA model, and 20 male Wistar rats were divided into 4 experimental groups: a non-injured and non-treated control group, a RA non-treated group, a group treated with LLLT (780 nm, 22 mW, 0.10 W/cm(2), spot area of 0.214 cm(2), 7.7 J/cm(2), 75 s, 1.65 J per point, continuous mode) from 12th hour after collagen-induced RA, and a group treated with LLLT from 7th day after RA induction with same LLLT parameters. LLLT treatments were performed once per day. All animals were sacrificed at the 14th day from RA induction and articular tissue was collected in order to perform histological analyses related to inflammatory process. We observed that LLLT both at early and late RA progression stages significantly improved mononuclear inflammatory cells, exudate protein, medullary hemorrhage, hyperemia, necrosis, distribution of fibrocartilage, and chondroblasts and osteoblasts compared to RA group (p < 0.05). We can conclude that LLLT is able to modulate inflammatory response both in early as well as in late progression stages of RA.

Effects of ultraviolet radiation (type B) on wound exudates, appearance and depth description.

Purulent exudate is one of the clinical signs of decubitus ulcers; and it is indicative of infection. The greatest challenge is the decreasing sensitivity of infective micro-organisms to antibiotics. There appears to be paucity of data on the effect of Ultraviolet radiation on wound exudates and appearance. The main purpose of this study was to determine the effect of ultraviolet radiation (Type B) on wound exudates and appearance of decubitus ulcers. Ten (10) bed-ridden subjects with ascertained bilateral sore from unrelieved pressure in their lower extremities consented to participate in the study. The decubitus ulcers were treated with traditional saline-wet-to-moist (WM) wound dressing. The decubitus ulcers on the left lower extremities were the experimental limbs and were exposed to ultraviolet radiation as adjunct while the right lower limbs served as control and received only the saline-wet-to-moist (WM) wound dressing. The frequency of treatment was 3 times per week for 6 weeks. The type of exudates produced, amount of exudates, wound appearance and depth description were scored on a 5-point likert scale. The data was analyzed using descriptive statistics and non-parametric inferential statistics (Kruska-Wallis test). The result of the Kruskal Wallis test showed that there was significant improvement in the type of exudates produced by the decubitus ulcers of the experimental (left) limbs (X{2} = 33.71, p < 0.00) when compared with the control limbs. Similarly, there was significant reduction in the amount of exudates produced by the decubitus ulcers of the experimental limbs (X{2} = 30.58, p < 0.00) when compared with that of the control. Also, there was significant improvement in the appearance of the decubitus ulcers (X{2} = 33.01, p< 0.00) and depth description of the experimental (left) limbs compared to that of the control (right). This study concluded that Ultraviolet radiation (Type B) can significantly improve the appearance of decubitus ulcers. Also, it can significantly reduce the amount of purulent exudates and can hasten skin replacement of decubitus ulcers.

An assessment of techniques for dehydrating root canals using infrared laser radiation.

Infrared lasers have been used for debridement and sterilisation of both soft and hard tissues, but there have been few studies of such laser applications in endodontics. The present laboratory study was undertaken to examine the feasibility of using pulsed infrared laser radiation to remove moisture from root canals (with an adjunctive sterilising effect). Canals were prepared in extracted teeth and a standardised technique used to fill the apical half of the root canal with saline. Pulses of CO2 or Nd:YAG laser energy were delivered into the root canal system via miniature applicators and residual fluid determined, as well as temperature changes on the root surface. With the CO2 laser, long pulse durations were effective at dehydrating the canals, but elicited deleterious thermal changes both locally within the canal as well as on the root surface. With Nd:YAG laser treatment, large temperature increases on the root surface occurred even with low powers and low pulse frequencies, and extended times were necessary for dehydration. With higher powers and pulse frequencies, complete dehydration could be achieved in less than 60 seconds, however root surface temperatures increased approximately 25 degrees, and the radicular dentine was damaged by the production of plasma. Dehydration of root canals could not be achieved safely with these two infrared lasers, and damage to both radicular dentine and the periodontal ligament would occur if these techniques were to be applied clinically. Alternative methods which do not exert significant thermal effects should be investigated.

Pteridines in the control of pigmentation.

The influence of UVB irradiation on the metabolic pathway for the production of L-tyrosine from L-phenylalanine in the human epidermis has been examined in 12 healthy volunteers with photo skin types I-VI (Fitzpatrick classification). This metabolic pathway involves the induction of GTP-cyclohydrolase 1 (GTP-CH-1), the rate-limiting enzyme for de novo synthesis of (6R)L-erythro-5,6,7,8-tetrahydrobiopterin (6-BH4). This essential cofactor controls the production of L-tyrosine from L-phenylalanine via phenylalanine hydroxylase (PAH). The de novo synthesis of 6-BH4 depends on the induction of GTP-CH-1, e.g., by tumor necrosis factor-alpha (TNF alpha). Epidermal suction blister tissues were taken before (0 h) and after (24 and 72 h) UVB exposure with a standardized dosage [1 minimal erythema dose (MED)]. In all cases, there was a significant increase in TNF alpha release, GTP-CH-1 activity, total 6-biopterin level, and PAH activity, indicative of enhanced L-tyrosine production. The response of this metabolic cascade over baseline activities was pronounced in fair photo skin types (I-III) compared to dark skin (IV-VI). Taken together, our results suggest that UVB can control the direct supply of L-tyrosine in the epidermis, and this process may represent an important factor in de novo melanogenesis.

Cytopathology of pleural effusions after radiotherapy.

The cytomorphology of pleural effusions following ionizing radiotherapy (IRT) has not been studied systematically. To determine if IRT produces alterations in pleural fluids that affect the cytopathologic interpretation of these specimens, two reviewers, without clinical information, independently assessed 55 specimens obtained following IRT and 39 control specimens obtained from nonirradiated cancer patients. None of the 24 cytologic features studied were identified significantly more frequently by both reviewers in the irradiated specimens. Only one feature (bizarre cells) was found to occur significantly more frequently in the irradiated specimens (36% versus 15%, P = .03) by either reviewer (reviewer B). Four other features showed a tendency to occur more frequently in the irradiated fluids by one or the other reviewer. They included degenerative changes (27% versus 13%, P = .09 [reviewer A]), smudgy chromatin (16% versus 5%, P = .09 [reviewer A]), large cytoplasmic vacuoles deforming the nuclei (44% versus 26%, P = .07 [reviewer B]) and cytomegaly (38% versus 23%, P = .12 [reviewer B]). The utility of these five features in identifying irradiated specimens was rigorously retested in a second masked review conducted jointly by the two pathologists. None of these features was found more frequently in the irradiated specimens in the second analysis. The results suggest that IRT does not consistently produce distinctive cytologic changes in pleural effusions and that a history of IRT should not affect the interpretation of these specimens.

[Transudative myopic maculopathy: pathogenetic validity and comparative effectiveness of laser interventions]. / Transsudativnaia miopicheskaia makulopatiia: patogeneticheskaia obosnovannost' i sravnitel'naia éffektivnost' lazernykh vmeshatel'stv.

The paper presents a retrospective (5-10 years) analysis of results of treatment in a group of patients (104 eyes) with "moist" myopic maculopathy and initial visual acuity from 0.04 to 0.3. Subretinal neovascular membranes were found in 59% of eyes. Localization of the membranes was subfoveolar in 48% of cases, parafoveolar--in 39%, extrafoveolar--in 13%, the size of them being to 300 micrometers in 28%, from 300 to 800--in 58%, more than 800--in 14% of cases. Comparative assessment of effectiveness of various kinds of laser coagulation, laser stimulation and conservative treatment has shown laser coagulation to be the most effective and pathogenetically substantiated method of treatment of neovascular membranes. The most resultant is laser coagulation by the type of "panmacular" in combination with radical laser coagulation of neovascular membranes (if they are present). The most radical is laser coagulation with preservation of a new point of gaze fixation, ensuring preservation of a rather high visual acuity, 0.3. Laser coagulation has a transient effect only in cases of myopic maculopathy without neovascular membranes. Conservative treatment is ineffective. Mechanisms of therapeutic action of laser coagulation and laser stimulation are discussed.

[Action of laser radiation on the peroxide chemiluminescence of wound exudate]. / Deistvie lazernogo izlucheniia na perekisnuiu khemiliuminestsentsiiu ranevogo ékssudata.

To assess the efficacy of laser therapy in the management of unresponding wounds and ulcers the method based on the estimation of chemiluminescence of tissue fluid in the presence of H2O2 was developed. It is suggested that laser radiation-induced decrease in chemiluminescence can be attributed to the activation of catalase in tissue fluid, which has an obvious positive therapeutic effect on reparative regeneration of wounds and ulcers.

Complement components in blood serum and suction blister fluid in erythropoietic protoporphyria.

Complement factor's C3c, C4, factor B, C3d and the immunoglobulin IgA were determined in suction blister fluid of patients with erythropoietic protoporphyria and in normal controls. The levels increased when the skin of the patients had been previously irradiated with 'white light', but with Kromayer radiation, and were interpreted as being the result of increased vasopermeability.

[Origin of a mitogrenic factor for cultivated macrophages (IMF: Inflammatory Mitogenic Factor) found in exudates of non-specific acute inflammation]. / Recherche sur l'origine d'un facteur mitogène pour les macrophages en culture (I.M.F.: Inflammatory Mitogenic Factor) présent dans des exsudats d'inflammations aiguës non spécifiques.

The mitogenic activity of inflammatory exudate obtained from irradiated Rats is reduced. After transfer of bone marrow syngeneic cells into irradiated Rats this mitogenic activity is further decreased, while after transfer of thymic cells it is increased. It is postulated that the mitogenic activity of inflammatory exudate could be related to thymic cells and that T lymphocytes may be involved in non specific-inflammatory reactions.

Kinetics of multinucleate giant cell formation and their modification by various agents in foreign body reactions.

Foreign body multinucleate giant cells were produced by the implantation of a strip of Melenex in the subcutaneous tissues of mice. The implants were removed at various intervals, and the proportion of multinucleate giant cells as well as the number of nuclei they contained were counted and statistically assessed. The greatest proportion of giant cells was reached 4 weeks after implantation, when 25% of the attached cells were multinucleated. The mean nuclear content however was greatest approximately 2 weeks after implantation and rapidly fell over the ensuing weeks. The fusion potential however, remained almost unaltered for the remainder of the experimental period. Transplantation of 7-day Melenex implants from normal donors into lethally irradiated recipients demonstrated that the halflife of the giant cells is only a few days. Treatment with carrageenin, species-specific antisera, actinomycin D and cortisone inhibited, while puromycin enhanced, multinucleate cell formation. Calcium gluconate, EDTA and irradiation had no significant effect. The possible interpretation of some of these findings is discussed.