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Absence of human papillomavirus DNA in the plume of erbium:YAG laser-treated warts.

BACKGROUND: The erbium:YAG laser (Continuum Biomedical, Dublin, Calif.) is a new resurfacing and ablating laser that produces minimal residual thermal damage. Laser safety requires careful attention to the hazards of the laser plume. It is important to know whether viable organisms survive in the vapors. Human papillomavirus (HPV) DNA has been detected in the vapor of carbon dioxide laser-treated and electrodesiccated human warts. The presence or absence of HPV DNA in the laser plume of erbium:YAG laser-treated warts has not been previously studied to our knowledge. OBJECTIVE: Our purpose was to determine the presence or absence of HPV DNA in the laser plume of erbium:YAG laser-treated human warts. METHODS: One half of clinically typical and histopathologically confirmed verrucae vulgares from five patients were submitted for HPV DNA detection with in situ hybridization. After erbium:YAG laser ablation of the remainder of the warts, the laser plume was deposited on the handpiece as an abundant fluffy material and was submitted for evaluation of HPV DNA by polymerase chain reaction with consensus primers for the HPV type detected in the wart specimens. RESULTS: HPV2 DNA was found in all warts. HPV DNA was not detected in the erbium:YAG laser plume after ablation of these same warts. CONCLUSION: The absence of HPV DNA in the plume of erbium:YAG laser-treated warts is a significant safety feature of this laser.

DNA, Viral↗

[Erbium laser phacoemulsification--a clinical pilot study].

INTRODUCTION: From August 1997 to March 1998, we performed a prospective pilot study to examine erbium laser phacoemulsification in cataract surgery under clinical conditions and to determine the side effects of this method. PATIENTS AND METHOD: 34 patients (40 eyes) with senile cataract were recruited. Slit lamp findings, keratometry, best corrected visual acuity, refraction, pachymetry, endothelial cell count and intraocular pressure were determined preoperatively and on 1st, 4th, 14th and 60th postop day according to a standardised protocol (single pulse energy between 10 and 20 mJ, frequency of application 60 Hz, average phaco time 3 min, total energy 38.5 mJ). The operations were done with the erbium laser system MCL 29, Aesculap-Meditec Co., Jena, Germany. RESULTS: A total emulsification of the nucleus was possible in 36 of 40 eyes (90%) (nucleus hardness between 0 and 3). A partial emulsification of the nucleus in nucleus hardness 3 was possible in 2 eyes, in nucleus hardness 4 in 1 eye and in nucleus hardness 2 in 1 eye (4 eyes--10%). Visual acuity increased from 0.3 preop to 0.8 two months postop (median). Intraocular pressure decreased from 16 mm Hg preoperatively to 13 mm Hg two months postoperatively (median). The increase of corneal thickness was not statistically significant compared to baseline. The decrease of endothelial cell count was 0.96%. Postoperative complications which are not known in ultrasonic phacoemulsification did not appear in erbium laser phacoemulsification. CONCLUSION: Erbium laser phacoemulsification is a surgical method that makes the emulsification of softer nuclei under clinical conditions possible with a low rate of complications also in the beginning of the learning curve. For higher nucleus hardnesses, technical and surgical parameters have to be optimised. Advantages of erbium laser phacoemulsification compared to ultrasonic phacoemulsification are less energy transmission into the eye, no heating of anterior chamber, impossibility of corneal burns and easier access in eyes that are deep into the orbit. Especially advantageous is the high protection of endothelium by erbium laser phacoemulsification. A prospective controlled comparative study to ultrasonic emulsification is desirable.

Aged↗

Combined erbium:YAG laser resurfacing and face lifting.

Facial aging occurs secondary to gravity-induced tissue ptosis and photoaging. Combined face lifting and carbon dioxide laser resurfacing provides a comprehensive one-stage approach to facial rejuvenation but is condemned by many plastic surgeons due to the nonspecific thermal effects of the laser and risk of skin necrosis. Newer high-energy erbium:YAG lasers allow precise tissue ablation with minimal thermal effect. In this study, various facial rejuvenation techniques were combined with simultaneous erbium:YAG laser resurfacing to assess results and complications. A total of 257 patients from Florida, Melbourne, Australia, and Tel Aviv, Israel, underwent combined erbium:YAG laser resurfacing and surgical facial rejuvenation. Various face-lift methods were used, including endoscopic, deep plane, and subcutaneous. Simultaneous, full-facial laser resurfacing was performed using a variety of erbium:YAG lasers. It was found that combined laser resurfacing and face lifting was successful in greater than 95 percent of patients with minimal morbidity. Two patients (1 percent) (both heavy smokers) developed small areas of skin necrosis that healed with minor pigment changes. Five patients (2 percent) developed synechia that was treated with no residual effect. Two additional patients (1 percent) developed temporary ectropion. There were no other cases of scarring, infection, or cosmetically obvious hypopigmentation. Although larger studies are necessary, it seems that the lack of thermal injury from the erbium:YAG laser makes it possible to safely perform laser resurfacing with surgical facial rejuvenation in nonsmokers. However, the authors caution that familiarity with the nuances of erbium:YAG laser resurfacing be obtained before performing combined laser resurfacing and face lifting.

Adult↗

Visible absorption spectra of the 4f electron transitions of neodymium, praseodymium, holmium and erbium complexes with fleroxacin and their analytical application.

The absorption spectra of the 4f electron transitions of neodymium, praseodymium, holmium and erbium complexes with fleroxacin in the presence of cetylpyridinium chloride were studied by normal and derivative spectrophotometry. Their molar absorptivity at the maximum absorption bands are about 5.3 (at 571 nm) times greater for neodymium, 2.8 (at 483 nm) times greater for praseodymium, 12.6 (at 448.5 nm) times greater for holmium and 9.7 (at 519 nm) times greater for erbium than those in the absence of complexing agents. The second-derivative spectrum is used both to eliminate the interference from other rare earths and to improve the sensitivity. Beer's law is obeyed from 3.0 - 70 microg ml(-1) for neodymium and holmium, from 6.0 - 70 microg ml(-1) for erbium, and from 12.0 - 70 microg ml(-1) for praseodymium. The relative standard deviations are 1.9% and 1.5% for 7.5 microg ml(-1) of neodymium and holmium, and 2.1% and 1.6% for 15.0 microg ml(-1) of praseodymium and erbium, respectively. Their detection limits (signal-to-noise ratio = 2) are 3.2 microg ml(-1), 1.3 microg ml(-1), (1.1) microg ml(-1) and 2.5 microg ml(-1) for praseodymium, neodymium, holmium and erbium, respectively. A new system for the simultaneous determinations of the praseodymium, neodymium, holmium and erbium in rare earth mixtures with good accuracy and selectivity is proposed.

Journal Article↗

Limitations of erbium:YAG laser photorefractive keratectomy.

PURPOSE: The erbium:YAG laser (lambda = 2.94 microm) has been considered promising as an alternative to the ArF excimer laser in photorefractive keratectomy (PRK). However, corneal application of this mid-infrared solid state laser is still plagued with various disadvantages compared to that of the ArF excimer laser (lambda = 193 nm). We discuss the limitations of PRK with the erbium:YAG laser. METHODS: Measurements of ablation threshold, ablation efficiency, and thermal damage were done to compare the process of erbium:YAG laser photoevaporization to the ArF excimer laser. PRK procedures were performed on fresh enucleated pig corneas to investigate the morphology and surface roughness of the cornea after scanning-spot and fundamental mode photoablation. Surface roughness was measured by using a tactile surface reprofiling system. RESULTS: The ablation threshold and the ablation efficiencies for the erbium:YAG laser are significantly higher compared to the ArF excimer laser. Collateral thermal damage decreases with a reduction of laser pulse duration to a minimum of approximately 5 microm. Scanning electron microscopy and surface roughness measurements of the corneal surface after erbium:YAG laser treatment demonstrated higher surface roughness compared to ArF excimer laser treatments. CONCLUSIONS: The erbium:YAG laser is not at present an alternative to the ArF excimer laser for photorefractive keratectomy.

Animals↗

Temperature and pressure effects during erbium laser stapedotomy.

BACKGROUND AND OBJECTIVES: Laser-assisted stapedotomy has become a well-established alternative to the mechanical drilling method. The goal of this study is to quantify the mechanical and thermal tissue effects and to determine optimum erbium laser parameters for safe clinical treatment. STUDY DESIGN/MATERIALS AND METHODS: On an inner ear model, time-resolved pressure measurements and Schlieren optical flash photography were performed during the perforation of the stapes foot plate using an erbium laser at 2.79 microns. The laser radiation was transmitted via an optical zirconium fluoride fiber. The laser-treated foot plates were investigated by light microscopy and scanning electron microscopy to visualise the laser-induced tissue effects. RESULTS: Perforation of the stapes foot plate can be performed with a few erbium laser pulses with high precision and a thermal damage zone of < 10 microns. Strong pressure transients were found to be generated by the bone ablation process and the collapse of a vapor channel created in the perilymph after fenestration. CONCLUSION: From the comparison of the laser-induced pressure with the limit graph to avoid hearing defects published by Pfander, an unobjectionable use of the erbium laser is deduced for fluences < 10 J/cm2. The erbium laser seems to represent an ideal instrument for middle ear surgery with all the advantages (precision, fiber optic transportable, high ablation efficiency, safety) desired for clinical application.

Erbium↗

Collagen tightening induced by carbon dioxide laser versus erbium: YAG laser.

BACKGROUND AND OBJECTIVE: Pulsed CO2 laser resurfacing improves photodamage and acne scarring by ablation of abnormal tissue with subsequent regeneration and remodeling of collagen and through heat induced collagen contraction. Whether collagen contraction persists long-term and helps maintain the skin tightening observed after resurfacing is debated. One possible mechanism of long-term clinical tightening is that of wound contracture that occurs as part of normal wound healing. If normal wound contracture, and not heat induced collagen contraction, is responsible for maintaining the initial skin tightening seen in CO2 laser resurfacing, then equal results would be expected from resurfacing with either CO2 or erbium lasers. The study was performed to determine whether there is a difference in skin tightening secondary to thermally mediated collagen contraction versus that which occurs secondary to tissue contraction of wound healing. The persistence of these changes over 6 months and the histologic characteristics were studied as well. STUDY DESIGN/MATERIALS AND METHODS: Nine patients had four tattoo dots applied to the upper eyelids, with horizontal axis measuring 18-20 mm and the vertical axis 6-10 mm. One month later, one eyelid was treated with three passes of the UltraPulse CO2 laser and the other eyelid with an erbium laser to the end point of early pinpoint bleeding. Three patients were treated with additional passes after pinpoint bleeding was encountered. The total number of pulses used per patient was recorded. Measurements of the vertical and horizontal distances were made after each pass and monthly for 6 months. The treated skin was then excised in performance of an upper lid blepharoplasty and the tissue submitted for histologic analysis. RESULTS: In the vertical plane, the UltraPulse CO2 laser induced an average of 43% tightening intraoperatively and this gradually diminished to an average of 34% by 6 months, whereas the wound contracture of erbium resurfacing was not seen until 1 month postoperatively, at which time 42% tightening was seen, gradually diminishing to 36% at 6 months. Three patients with erbium resurfacing had scarring present. These were the three patients treated most aggressively and also the three patients with the most significant wound contracture. Scarring was not seen on the CO2 treated side in any patients. In the horizontal plane, the CO2 laser caused 31% intraoperative tightening, decreasing to 19% at 6 months. In this plane, the erbium laser induced wound contracture was 12% at 1 month which remained stable and unchanged. CONCLUSIONS: Although wound contraction secondary to tissue healing may result in nearly the same tissue tightening as heat-induced collagen contraction, the two processes are very different and variable, with increased risk of scarring seen with wound contracture, compared with heat-induced collagen tightening. The tissue tightening seen with thermally induced collagen contraction is long-lasting, if not "permanent."

Blepharoplasty↗

The effect of erbium on the adsorption and photodegradation of orange I in aqueous Er3+-TiO2 suspension.

Pure TiO(2) and erbium ion-doped TiO(2) (Er(3+)-TiO(2)) catalysts prepared by the sol-gel method were characterized by means of XRD and diffusive reflectance spectra (DRS). The XRD results showed that erbium ion doping could enhance the thermal stability of TiO(2) and inhibit the increase of the crystallite size, and the DRS results showed that the optical absorption edge slightly shifted to red direction owing to erbium ion doping and the Er(3+)-TiO(2) catalysts had three typical absorption peaks located at 490, 523 and 654 nm owing to the transition of 4f electron from (4)I(15/2) to (4)F(7/2), (2)H(11/2) and (4)F(9/2). With a purpose of azo dyes degradation, orange I was used as a model chemical. And the adsorption isotherm, degradation and mineralization of orange I were investigated in aqueous suspension of pure TiO(2) or Er(3+)-TiO(2) catalysts. The results showed that Er(3+)-TiO(2) catalysts had higher adsorption equilibrium constants and better adsorption capacity than pure TiO(2). The adsorption equilibrium constants (K(a)) of Er(3+)-TiO(2) catalysts were about twice of that of pure TiO(2). The maximum adsorption capacity (Q(max)) of 2.0% Er(3+)-TiO(2) catalyst was 13.08x10(-5)mol/g, which was much higher than that of pure TiO(2) with 9.03x10(-5)mol/g. Among Er(3+)-TiO(2) catalysts, 2.0% Er(3+)-TiO(2) catalyst achieved the highest Q(max) and K(a) values. The kinetics of the orange I degradation using different Er(3+)-TiO(2) catalysts were also studied. The results demonstrated that the degradation and mineralization of orange I under both UV radiation and visible light were more efficient with Er(3+)-TiO(2) catalyst than with pure TiO(2), and an optimal dosage of erbium ion at 1.5% achieved the highest degradation rate. The higher photoactivity under visible light might be attributable to the transitions of 4f electrons of Er(3+) and red shifts of the optical absorption edge of TiO(2) by erbium ion doping.

Adsorption↗

Structural changes in human dental enamel after subablative erbium laser irradiation and its potential use for caries prevention.

Numerous studies have confirmed the potential of erbium laser irradiation for increasing the acid resistance of dental enamel. The objective of the present paper was to investigate the effect of subablative erbium laser irradiation on the structure and acid resistance of dental enamel by means of confocal laser scanning microscopy (CLSM). To this end, 12 samples of human dental enamel were irradiated with subablative energy densities (Phi) of an Er:YAG (lambda = 2.94 microm, Phi = 6 J/cm(2)) and an Er:YSGG laser (lambda = 2.79 microm, Phi = 8 J/cm(2)). The enamel surfaces of 6 samples were polished prior to irradiation. The remaining 6 samples were left intact (without polishing procedures) and, in the further course of the study, they were subjected to 1-week in situ demineralisation. All irradiated test surfaces were assigned a control surface on the same sample. The changes following laser irradiation and the in situ wearing time were assessed qualitatively using a confocal laser scanning microscope. The irradiation of dental enamel with subablative erbium laser irradiation produces fine cracks in the enamel surface. These cracks act as starting points for acid attack and favour deep demineralisation. These changes reduce or eliminate the positive effect of subablative erbium laser irradiation observed in connection with caries-preventive use. The clinical use of subablative erbium laser irradiation to prevent caries would appear not to make sense under the conditions studied.

Dental Caries↗

Laser resurfacing with a long pulse erbium:YAG laser compared to the 950 ms pulsed CO(2) laser.

BACKGROUND AND OBJECTIVE: Laser resurfacing with the 950 micros pulsed CO(2) laser is an effective treatment for photodamage and acne scarring; however, the potential for prolonged erythema and delayed re-epithelialization dissuade many patients from the procedure. With the use of erbium lasers alone, there is a decrease in the incidence and severity of these adverse sequelae; however, it is difficult to achieve the same degree of improvement as with the CO(2) laser because of the more superficial depth of resurfacing. Thus, new erbium lasers have been developed with longer pulse durations to deliver increased thermal effects to tissue. It is hypothesized that with the use of these lasers, diminished erythema and faster wound healing will be observed as well as enhanced clinical outcomes. STUDY DESIGN/MATERIALS AND METHODS: Sixteen patients were randomized to receive laser resurfacing on one-half of the face with the 950 micros pulsed CO(2) laser (UPCO(2)) followed by short pulse erbium:YAG ablation, and to the other half with a variable pulsed erbium laser (VP Er:YAG) followed by traditional short pulse erbium laser. Patients were evaluated clinically before resurfacing and at 1, 2, 4, 8, and 12 weeks post-operatively. Histologic samples taken at various time periods before and after resurfacing were also evaluated. RESULTS: Overall clinical improvement was equal for both UPCO(2) and VP Er:YAG treated sides with an average improvement in photoaging scores of 57%. Decreased erythema, less edema, and faster healing were observed on the VP Er:YAG treated side. CONCLUSION: The VP Er:YAG laser can achieve a similar degree of improvement as seen with short pulse CO(2) laser resurfacing with decreased thermal tissue effects and decreased risk for adverse sequelae.

Face↗

[CO2 and erbium YAG laser in eyelid surgery. A comparison].

BACKGROUND: Lasers are finding increasing use in cosmetic and reconstructive plastic surgery. We compared the erbium-YAG laser and the CO2 laser to conventional eyelid surgery with a scalpel. MATERIAL AND METHODS: We operated on 58 patients using the erbium-YAG laser and on 32 using the CO2 laser. Surgeries were benign tumor excisions and removal, xanthelasma removal, lower and upper eyelid blepharoplasties, and skin resurfacing in the area of the lower eyelid. RESULTS: Wound healing with the CO2 laser was significantly slower because of its larger thermal necrosis zone, but the hemostasis with the CO2 laser makes removal of deeper lesions easier. Advantages are the wide application spectrum for incisional and ablative surgery. The erbium-YAG laser is an excellent for ablating superficial benign lesions, including that in the area of the lid margin and close to the lacrimal puncta without scars. SUMMARY: The application spectrums of the erbium-YAG and CO2 lasers complement one another. The erbium-YAG laser is superior for esthetic skin resurfacing and ablation of superficial lesions, and the CO2 laser allows hemorrhage-free noncontact incisional surgery.

Blepharoplasty↗

Erbium: yttrium-aluminum-garnet laser induced vapor bubbles as a function of the quartz fiber tip geometry.

BACKGROUND: The use of modern erbium: yttrium-aluminum-garnet (YAG) laser systems in opthalmic microsurgery requires a precise knowledge of the size and dynamics of the laser induced vapor bubbles. The aim of this work was to clarify the possibilities of controlling the vapor bubble shape and size by using an optimized fiber tip geometry for various ophthalmic applications with the erbium: YAG laser. METHODS: The mid-infrared radiation of free-running erbium: YAG laser was coupled optically into means of different low OH(-) quartz fiber tips to investigate the vapor bubble formation in water by high-speed photography. The core diameter of four fiber tips ranged from 200 up to 940 microm. Fourteen fiber tips were polished at an angle graduated from 10 degrees to 70 degrees over the full core diameter (seven fiber tips) and over the half core diameter (seven fiber tips). Three fiber tips were produced to have a curvature at the distal end with curvature radii of 160, 230, and 420 microm. RESULTS: The shape as well as the size of erbium: YAG laser induced vapor bubbles can be controlled systematically by using adequate fiber tip geometries. In detail, the used different angles and curvatures demonstrate that the propagation direction of the vapor bubbles can be estimated by optical modeling considering Snell's law and the Fresnel laws at a quartz-air boundary. Beside this, the size of a vapor bubble can be predetermined by choosing ideal fiber tip geometries to reduce or increase the radiant exposure at the distal end of the quartz fiber tip. CONCLUSIONS: The good possibility of controlling the shape and size of vapor bubbles offers a wider range of new applications, especially in ophthalmic microsurgery such as erbium YAG laser vitrectomy.

Equipment Design↗

Minimally invasive skin rejuvenation with Erbium: YAG laser used in thermal mode.

BACKGROUND AND OBJECTIVES: To evaluate the efficacy and safety of a thermal mode Erbium:YAG laser several in-vivo morphological as well as clinical changes were monitored in a multi-center investigation. STUDY DESIGN/MATERIALS AND METHODS: An Erbium:YAG laser was used at a thermal mode with sub-ablative fluences of 2.1 and 3.1 J/cm(2) with parallel air cooling to treat either periorbital, perioral rhytides or patients with post-traumatic or acne scars. Two treatments were applied 2 months apart, with follow-up at 1, 3, 6, and 12 months post-treatment. Photographs were taken before and at each follow-up visit and evaluated by three blinded independent reviewers. Histology and immunohistochemistry for pro-collagen expression were investigated. Optical coherence tomography (OCT) was performed before, and at 4, 14, and 28 days after single pass treatment with Erbium:YAG thermal pulses. RESULTS: The improvement of rhytides at 1-3 months follow-up was graded as excellent in 19%, good in 19%, fair in 31%, and no improvement in 31%. At the 6- to 12-month follow-up, the improvement was excellent in 40%, good in 40%, fair in 20%, and no improvement in 0%. The improvement of scars at 3-6 months follow-up was graded as excellent in 50%, good in 25%, fair in 25%, and no improvement in 0%. Intra- and post-operative discomfort was described as mild by the patients. OCT, histological sections and immunohistochemistry demonstrated production of new collagen bundles. CONCLUSIONS: Thermal Erbium:YAG pulses can induce collagen neogenesis, as proved by temperature elevation and morphological changes in the upper dermis. This leads clinically to visible and long lasting reduction of wrinkles and scars after applying multiple passes with minimal side-effects.

Adult↗

[Chronic polyarthritis and radiosynoviorthesis: a prospective, controlled study of injection therapy with erbium 169 and rhenium 186].

The aim of this prospective study was to evaluate the efficiency of radiation synovectomy with rhenium-186 or erbium-169 in rheumatoid arthritis. In the control groups articulosynovitis was treated by injection of triamcinolonhexacetonid. Follow-up time was 3 years. Patients of the study had to fulfill the following criteria: rheumatoid arthritis (ARA criteria 1988), patient age above 40 years, standardized medical treatment with methotrexate, (started at least 6 month prior to injection therapy, given for the entiry study time), prednisolon < or = 7.5 mg/d and diclofenac < or = 150 mg/ d, and no previous surgery or injection therapy on this/these joint/s. Shoulder, elbow, wrist, and ankle joints were treated in group 1 by injection of rhenium-186 combined with triamcinolonhexacetonid, in group 2 by injection of triamcinolonhexacetonid alone. Each treatment group included 50 joints. Digital joints underwent injection of erbium-169 combined with triamcinolonhexacetonid (group 3 = 131 joints) or triamcinolonhexacetonid (group 4 = 86) alone. During the follow up period, the joints were assessed for pain, synovial swelling, joint motion, and stage of radiological destruction (Larsen-Dale-Eek). After 3 years follow-up, 228 joints met the above named criteria: group 1 = 41 joints, group 2 = 21 joints, group 3 = 131 joints, group 4 = 53 joints. Significantly better clinical results were achieved with the combined injection of rhenium-186 or erbium-169 and triamcinolonhexacetonid. Results for PIP joints were worse than for other joints, which is explained by better immobilization of the latter ones after injection. The progression in radiological joint destruction according to the stages of Larsen-Dale-Eek during the follow-up time of 3 years (= stage at 3 years minus stage prior to treatment) corresponded to the clinical results and was significantly slower in groups 1 and 3: group 1 = 0.62; group 2 = 1.7; group 3 = 0.75; group 4 = 1.43 Therefore, we recommend radiosynovectomy with erbium-169 or rhenium-168 in combination with triamcinolonhexacetonid and consequent immobilization after injection.

Adult↗

Erbium:YAG laser treatment of post-burn scars: potentials and limitations.

Erbium:YAG lasers are successfully used to treat a variety of epidermal and dermal lesions, including rhytides, dyschromias, and certain types of scars. To date, however, no report has focused on the experiences with this laser in reconstructive burn surgery. Since 2001, the Erbium:YAG laser has become an integral part of the treatment of postburn scars at the Berlin Burn Center. This paper presents the techniques applied and clinical experiences obtained. In addition, a new stripe technique is introduced, which avoids healing disturbances in scars following deep burns. In conclusion, the Erbium:YAG laser has proven to be a valuable supplementary tool for the improvement of cosmetically disturbing mild postburn scars. It is particularly handy in areas difficult to treat, such as the eyes, nose, lips, and fingers. The individual advantages of the Erbium:YAG laser, other laser systems, and dermabrasion for the treatment of burn scars are compared in a brief survey.

Adolescent↗

Interactions between metal ions and carbohydrates. The coordination behavior of neutral erythritol to lanthanum and erbium ions.

Lanthanide ions and erythritol form metal-alditol complexes with various structures. Lanthanum nitrate and erbium chloride coordinate to erythritol to give new coordination structures. The lanthanum nitrate-erythritol complex (LaEN), 2La(NO3)3.C4H10O(4).8H2O, La3+ exhibits the coordination number of 11 (namely 11 polar atoms bound to one lanthanum) and is 11-coordinated to two hydroxyl groups from one erythritol molecule, six oxygen atoms from three nitrate ions and three water molecules. One erythritol molecule is coordinated to two La3+ ions and links the two metal ions together. The ratio of M:L is 2:1. The erbium chloride-erythritol complex (ErE), ErCl2.C4H9O(4).2C2H5OH was obtained from ErCl3 and erythritol in aqueous ethanol solution and the structure shows that deprotonation reaction occurs in the reaction process. The Er3+ cation is 8-coordinated with three hydroxyl groups of one erythritol molecule, two hydroxyl groups from another erythritol molecule, two ethanol molecules, and one chloride ion. Erythritol provides its three hydroxyl groups to one erbium cation and two hydroxyl groups to another erbium cation, that is, one hydroxyl group is coordinated to two metal ions and therefore loses its hydrogen atom and becomes a oxygen bridge. Another chloride ion is hydrogen bonded in the structure. The results indicate the complexity of metal-sugar coordination.

Crystallization↗

Superficial erbium:YAG laser resurfacing of photodamaged skin.

BACKGROUND: Light chemical peels and microdermabrasion have enjoyed recent popularity for the treatment of mild photoaging. However, clinical improvement from these modalities is often minimal from both a patient's and physician's perspective. Erbium:YAG lasers have been effective in treating mild to moderate photoaging, but the need for either regional or general anesthesia, as well as the significant post-treatment recovery period has limited its use. OBJECTIVE: We sought to utilize a very low fluence approach to erbium:YAG laser resurfacing, with topical anesthesia, to ascertain its efficacy in treating mild to moderate photoaging. METHODS: A total of 250 subjects aged 28-80 years with skin types 1-4 and mild to moderate facial rhytids were treated with topical anesthesia and subsequently one pass of a 2940 nm erbium:YAG laser, using between 5 and 17.5 J/cm2. In addition, 58 of the treated facial subjects underwent neck resurfacing with fluences between 5 and 15 J/cm2 and eight treated facial subjects underwent upper chest resurfacing at fluences of 5-7 J/cm2. A single treatment was received by 246 subjects; four subjects were treated a second time after a 1-month interval. RESULTS: Most subjects completely re-epithelialized by 3-4 days; healing time was depth dependent. Most subjects were able to start skin care regimens within 1-2 weeks after the procedure. Results were judged to be excellent in individuals with thin skin and good in subjects with thicker skin. CONCLUSIONS: One pass of low fluence erbium:YAG resurfacing, under topical anesthesia, was effective for the treatment of mild to moderate photoaging.

Adult↗

Physical and biological dosimetry in patients undergoing radiosynoviorthesis with erbium-169 and rhenium-186.

Physical and biological dosimetry were investigated in 45 rheumatoid arthritis patients treated by radiosynoviorthesis (RSO) with 186Re-sulphide (medium-sized joints) and 169Er-citrate (digital joints). Biological dosimetry involved scoring dicentrics in lymphocytes, cultured from blood samples withdrawn just before and 6 h, 24 h and 7 days after treatment. Physical methods included repeated blood sample counts and scintigraphy data. For erbium-169 (pure beta emitter), only bremsstrahlung could be measured and solely in the injection area. For rhenium-186 (both beta and gamma emitter), whole body scans and static images of joints and locoregional lymph nodes were performed. Dosimetry calculations were in accordance with the MIRDOSE 3 software and tables. For erbium-169 (21 patients), either metacarpophalangeal (30 MBq) or proximal interphalangeal (20 MBq) joints of the hands were treated (one joint per patient); 18 patients (out of 21) were interpretable for biological dosimetry, 10 (out of 11) for physical dosimetry and six (out of 10) for both. For rhenium-186, 23 wrists, nine elbows, three shoulders and two ankles were injected in 24 patients, with a maximum of three joints per patient (70 MBq per joint); 20 patients (out of 24) and 10 (out of 10) were interpretable for biological and physical dosimetry, respectively, and eight (out of 10) for both methods. Erbium-169 biological dosimetry was negative in all interpretable patients, and physical dosimetry gave a blood dose of 15 +/- 29 microGy and an effective dose lower than 1 mSv/30 MBq. For rhenium-186, biological results were negative in 16 patients (out of 20), but showed a blood irradiation around 200 mGy in the last four. A significant cumulative increase of dicentrics 7 days after injection (16/10,000 instead of 5/10,000 prior to treatment; p < 0.04) was also noted. Gamma counts gave a blood dose of 23.9 +/- 19.8 mGy/70 MBq and the effective dose was found to be 26.7 +/- 5.1 mGy/70 MBq, i.e. about 380 microGy.MBq-1. Erbium-169 RSO is very safe from both physical and biological dosimetry standpoints. Rhenium-186 leak is greater, as demonstrated by the higher blood activity and the measurable, although limited, dicentrics induction in blood lymphocytes. However, the effective dose remains moderate, i.e. 30 times lower than in 131I therapy in benign thyroid diseases.

Adult↗