VEGFR2 promotes central endothelial activation and the spread of pain in inflammatory arthritis

Chronic pain can develop in response to conditions such as inflammatory arthritis. The central mechanisms underlying the development and maintenance of chronic pain in humans are not well elucidated although there is evidence for a role of microglia and astrocytes. However in pre-clinical models of pain, including models of inflammatory arthritis, there is a wealth of evidence indicating roles for pathological glial reactivity within the CNS. In the spinal dorsal horn of rats with painful inflammatory arthritis we found both a significant increase in CD11b⁺ microglia-like cells and GFAP⁺ astrocytes associated with blood vessels, and the number of activated blood vessels expressing the adhesion molecule ICAM-1, indicating potential glio-vascular activation. Using pharmacological interventions targeting VEGFR2 in arthritic rats, to inhibit endothelial cell activation, the number of dorsal horn ICAM-1⁺ blood vessels, CD11b⁺ microglia and the development of secondary mechanical allodynia, an indicator of central sensitization, were all prevented. Targeting endothelial VEGFR2 by inducible Tie2-specific VEGFR2 knock-out also prevented secondary allodynia in mice and glio-vascular activation in the dorsal horn in response to inflammatory arthritis. Inhibition of VEGFR2 in vitro significantly blocked ICAM-1-dependent monocyte adhesion to brain microvascular endothelial cells, when stimulated with inflammatory mediators TNF-α and VEGF-A₁₆₅a. Taken together our findings suggest that a novel VEGFR2-mediated spinal cord glio-vascular mechanism may promote peripheral CD11b⁺ circulating cell transmigration into the CNS parenchyma and contribute to the development of chronic pain in inflammatory arthritis. We hypothesise that preventing this glio-vascular activation and circulating cell translocation into the spinal cord could be a new therapeutic strategy for pain caused by rheumatoid arthritis.

Amputation neuroma of the great auricular nerve after operations on the parotid gland

We found an incidence of 6% (5/81) of traumatic neuroma after section of the great auricular nerve during operations on the parotid gland. Excision permits definitive diagnosis, the stump being allowed to retract beneath the belly of the sternomastoid muscle. However, excision is not always indicated, and the diagnosis can be made clinically allowing for a more conservative treatment policy.

Trans rectal ultrasound guided radioactive seed implant: the Sumter experience

108 patients were treated between 1/06/97 and 7/19/99. Ages ranged from 53 years to 82 years. Pretreatment PSA ranged from 4.0 to 34.6 and post treatment PSA from 0 to 7.3. Given the fact that carcinoma of the prostate is a relatively slow growing tumor and that long survival times are not uncommon even in the face of relatively advanced disease, our treatment team believes that the preferred method of treatment in otherwise healthy patients who have a 20 year life expectancy is radical surgery. We do believe that brachytherapy has a role in the treatment of organ-confined disease and may possibly be proven to be as effective as surgery; however, until there is at least 15-year data, it cannot be considered as the primary treatment of choice in young men. The senior author has stressed the term "treatment team" in this paper for a reason. We sincerely believe that the best results for our patients are obtained when we approach the treatment of the patient as a unified team that makes use of our individual talents and training for the good of the patient as a whole. Each member of the team performs the procedures that he is best trained to do, and we are consistent in our approach and advice to our patients regardless of our disciplines.

Lingual access for third molar surgery: a 20-year retrospective audit

We describe a technique for obtaining lingual access for the insertion of a wide metal retractor to protect the lingual nerve from accidental damage during third molar surgery. We also report an audit of a single practice over a 20-year period using the technique described. The approach involves raising soft tissues on the lingual side of the lower third molar tooth to allow insertion of a broad Hovell's lingual retractor. We conclude that raising lingual tissues to form a wide tension-free flap and inserting a specifically designed retractor does not increase the incidence of lingual nerve morbidity. Indeed, the overall incidence of lingual nerve damage was particularly low compared with those in other published series.

Safety recommendations for laser pointers

The use of laser diode pointers that operate in the visible radiation region (400-760 nm) is becoming widespread. These pointers are intended for use by educators while presenting talks in the classroom or at conventions and meetings. They are also useful in any situation where one needs to point out special items during any instructive situation. The pointers can be purchased in novelty stores, mail-order magazines, office supply stores, common electronic stores, and over the internet. The power omitted by these laser pointers ranges from 1 to 5 mW. The potential for hazard with laser pointers is generally considered to be limited to the unprotected eyes of individuals who might be exposed by a direct beam (intrabeam viewing). No skin hazard usually exists. There are, however, even more powerful laser pointers now appearing. The units are imported into the U.S. often without proper manufacturer certification or labeling. The potential for hazards with these devices is not well understood by the general public and workers, and numerous exposure incidents have been recorded by the authors. Users of these products need to be alerted to the potential hazards and be encouraged to follow appropriate safety recommendations. These factors are discussed and safety recommendations for laser pointers are presented.

Induced radioactivity of LDEF materials and structural components

We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEO) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design.

Waldenstrom's macroglobulinemia: search for occupational exposure

Two cases of Waldenstrom's macroglobulinemia (WM) that occurred in employees from one university academic department were investigated using approaches for both cluster and single case investigation. Common personal characteristics and potential past hazardous exposures were evaluated. The patients shared a young age at diagnosis, worked in the same building, and had similar duration of time between first entering the building and diagnosis of WM. No evidence was found to support the original hypothesis that exposure to radioactive material could be related to the occurrence of WM. Although this investigation did not identify a common causal agent among two cases of a rare disease, investigations of disease clusters may be useful for developing etiologic hypotheses even when a full-scale epidemiologic study is not undertaken. Detailed descriptions of case characteristics can help generate ideas for further research.

Foot currents and ankle SARs induced by dielectric heaters

Data are presented on ankle-specific SARs and foot currents as a function of strengths of radio-frequency electromagnetic fields encountered by operators of dielectric heaters. The determination of foot currents was based on near-field exposures in which reactive coupling dominates, and which can result in substantial SARs in exposed workers. The operators were located less than one wavelength from--usually within one meter of--the dielectric heaters, which generated fields at frequencies from 6.5 to 65 MHz. At distances normally assumed by workers, maximal strengths of electric fields ranged from 10(4) to 2.4 x 10(6) V2/m2; maximal strengths of magnetic fields ranged from 5.0 x 10(-3) to 33.3 A2/m2. Currents through both feet to ground were measured while operators stood where they normally worked. Maximal currents ranged from 3 to 617 mA, rms. Nearly 27 percent of the dielectric heaters induced foot currents that exceeded the 200-mA limit that has been proposed for a new ANSI C95.1 standard. Twenty percent of the heaters induced foot currents that exceeded 350 mA. SARs in ankles were calculated from foot currents, and they approximated 5 W/kg at 100 mA, 29 W/kg at 250 mA, and 57 W/kg at 350 mA. The maximal SAR in the ankle was approximately 176 W/kg at 617 mA.

Visible-light system for detecting doxorubicin contamination on skin and surfaces

A portable system that uses fluorescence stimulated by visible light to identify doxorubicin contamination on skin and surfaces was studied. When activated by violet-blue light in the 465-nm range, doxorubicin fluoresces, emitting orange-red light in the 580-nm range. The light source to stimulate fluorescence was a slide projector with a filter to selectively pass short-wave (blue) visible light. Fluorescence was both observed visually with viewing spectacles and photographed. Solutions of doxorubicin in sterile 0.9% sodium chloride injection were prepared in nine standard concentrations ranging from 2 to 0.001 mg/mL. Droplets of each admixture were placed on stainless steel, laboratory coat cloth, pieces of latex examination glove, bench-top absorbent padding, and other materials on which antineoplastics might spill or leak. These materials then were stored for up to eight weeks and photographed weekly. The relative ability of water, household bleach, hydrogen peroxide solution, and soap solution to deactivate doxorubicin was also measured. Finally, this system was used to inspect the antineoplastic-drug preparation and administration areas of three outpatient cancer clinics for doxorubicin contamination. Doxorubicin fluorescence was easily detectable with viewing spectacles when a slide projector was used as the light source. The photographic method was sensitive for doxorubicin concentrations from 2.0 to 0.001 mg/mL. Immersion of study materials in bleach for one minute eliminated detectable fluorescence. Doxorubicin contamination is detectable for at least eight weeks in the ambient environment. Probable doxorubicin contamination was detected in two of the three clinics surveyed. A safe, portable system that uses fluorescence stimulated by visible light is a sensitive method for detecting doxorubicin on skin and surfaces.

Optical radiation hazards of laser welding processes. Part II: CO2 laser

There has been an extensive growth within the last five years in the use of high-powered lasers in various metalworking processes. The two types of lasers used most frequently for laser welding/cutting processes are the Neodymium-yttrium-aluminum-garnet (Nd:YAG) and the carbon dioxide (CO2) systems. When such lasers are operated in an open beam configuration, they are designated as a Class IV laser system. Class IV lasers are high-powered lasers that may present an eye and skin hazard under most common exposure conditions, either directly or when the beam has been diffusely scattered. Significant control measures are required for unenclosed (open beam), Class IV laser systems since workers may be exposed to scattered or reflected beams during the operation, maintenance, and service of these lasers. In addition to ocular and/or skin exposure hazards, such lasers also may present a multitude of nonlaser beam occupational concerns. Radiant energy measurements are reported for both the scattered laser radiation and the plasma-related plume radiations released during typical high-powered CO2 laser-target interactions. In addition, the application of the nominal hazard zone (NHZ) and other control measures also are discussed with special emphasis on Class IV industrial CO2 laser systems.

Hazard zones and eye protection requirements for a frosted surgical probe used with an Nd:YAG laser

Detailed radiometric analyses are reported on selected frosted-style laser surgical probes that are in use in laser surgical procedures. These measurements were performed in order to determine their nominal hazard zone (NHZ) and the requirement for protective eyewear. All measurements were conducted under worst-case conditions using a 30-W Nd:YAG laser. The results show that for the style of probe tested, the NHZ can be considered a spherical volume of 1.3 m and will require eye protection devices having a maximum optical density rating of 4.3 at 1.06 microns for all personnel who may come within that range.

Evaluation of a smoke evacuator used for laser surgery

A preliminary study was conducted to determine the effectiveness of a smoke evacuation system used in laser surgery. A 30 W medical CO2 continuous wave (CW) laser was used to make cuts in a pork chop to simulate smoke production during laser surgery. A commercially available smoke evacuation system was used to control the smoke from the simulated surgery. The smoke concentration was measured at 6 in and at 3 and 4 ft from site of laser interaction. The nozzle of the smoke evacuator was located at distances of 2, 6, and 12 in from the surgical site to measure the relative effectiveness of the control. Complete control of smoke was achieved when the nozzle was located at 2 in, but significant amounts of smoke escaped when the nozzle was located at 6 and 12 in. Suggestions for the use of the smoke evacuation system and areas for further study are given.

Optical radiation hazards of laser welding processes. Part 1: Neodymium-YAG laser

High power laser devices are being used for numerous metalworking processes such as welding, cutting and heat treating. Such laser devices are totally enclosed either by the manufacturer or the end-user. When this is done, the total laser system is usually certified by the manufacturer following the federal requirements of the Code of Federal Regulations (CFR) 1040.10 and 10.40.11 as a Class I laser system. Similarly, the end-user may also reclassify an enclosed high-power laser into the Class I category following the requirements of the American National Standards Institute (ANSI) Z-136.1 (1980) standard. There are, however, numerous industrial laser applications where Class IV systems are required to be used in an unenclosed manner. In such applications, there is concern for both ocular and skin hazards caused by direct and scattered laser radiation, as well as potential hazards caused by the optical radiation created by the laser beam's interaction with the metal (i.e. the plume radiation). Radiant energy measurements are reported for both the scattered laser radiation and the resultant plume radiations which were produced during typical unenclosed Class IV Neodymium-YAG laser welding processes. Evaluation of the plume radiation was done with both radiometric and spectroradiometric measurement equipment. The data obtained were compared to applicable safety standards.

A radiation and industrial hygiene survey of video display terminal operations

Radiation surveys were performed on 136 terminals of some 530 in use at three different sites. Researchers measured both ionizing and nonionizing radiation. In the industrial hygiene survey, samples of workroom air were analyzed to determine worker exposure to selected airborne chemical contaminants. The results of these tests demonstrated that the VDT operators included in this investigation were not exposed to hazardous levels of radiation or chemical agents.

Semitransparent curtains for control of optical radiation hazards

The purposes and functions of semitransparent eye protective curtains are analyzed. Based upon this analysis, functional requirements are developed, and design requirements are specified for optimum curtains to be used with open arc welding and arc cutting processes. Such curtains also protect against other high intensity broad-spectral-band sources such as compact arc lamps. The requirements for filtering our hazardous UV radiation and blue light must be balanced against the need for transparency in the visible spectrum and the need for reduced glare. Infrared attenuation is shown to be of very little importance.

Gamma Ray Decay Schemes of Levels at Intermediate Energies in 32S

The reaction 32S(p,p'y)32S has been studied with a 12'7 cm by 10�2 cm NaI(TI) y-ray detector in conjunction with a 61 cm double-focusing magnetic spectrometer to determine the y-ray decay schemes of all known levels in 32S between the excitation energies of 5�40 and 7� 15 MeV.

The 5·80 MeV State of 32S

Studies of the reaction 29Si(a, n?)32S indicate that the 5 �80 MeV state of 32S has an excitation energy of 5798� 2�1� 0 keV, a mean lifetime of 14�7 fs, and a spin of 1. Particle?gamma coincidence studies of the reaction 32S(p,p'?)32S indicate that the state decays 100% to the 0+ ground state, with all other possible transitions having intensities ? 2% of the ground state transition. The properties of the state are shown to be consistent with those expected for the 1? member of the negative parity quintuplet predicted by the coupled quadrupole?octupole vibrator model.