Radionuclides in marine fishes and birds from Amchitka and Kiska Islands in the Aleutians: establishing a baseline

Amchitka Island (51degrees N lat, 179 degrees E long) was the site of three underground nuclear tests from 1965-1971. There have been no substantive studies of radionuclides in marine fishes and birds in the area since the mid-1970's. In this study, levels of 60Co, 52Eu, 90Sr, 99Tc, 129I, 137Cs, and the actinides (241Am, 238Pu, 239,240Pu, 234U, 235U, 236U, and 238U) were studied in ten marine fish species (including Pacific Cod Gadus macrocephalus and Pacific Halibut Hippoglossus stenolepis) and five marine bird species (including Glaucous-winged Gulls Larus glaucescens, Tufted Puffins Fratercula cirrhata, and Common Eider Ducks Somateria mollissima) from Amchitka. The same species were collected at a reference site, Kiska Island (52 degrees N lat; 177 degrees E long), about 130 km west of Amchitka. Each sample was a composite of edible muscle from five or more individual fish or birds of similar size (+/-15%) from the same sampling station. The null hypotheses of no differences among species or between Amchitka and Kiska were tested. Most analytic results were below the minimum detectable activity (MDA), even when 1,000 g sizes and 72 h counting times were used. The only radionuclides detected above the MDA were 137Cs, 241Am, 239,240Pu, 234U, 235U, and 238U. There were significant differences in 137Cs as a function of species, but not location, for top predatory fishes. Of the fishes, eight of ten species had 137Cs values above the MDA for some samples; only one bird, Glaucous-winged Gull, had 137Cs values above the MDA. The highest concentrations of 137Cs were in Dolly Varden [Salvelinus malma, 0.780 (Bq kg(-1) wet weight)] and Pacific Cod (0.602 Bq kg(-1)). In aggregate for any actinides, 73 of 234 (31%) composites for fish were above the MDA, compared to only 3 of 98 (3%) for birds. 234U and 238U, radionuclides that are primarily natural in origin, were routinely detected in these biological samples, but there were no significant differences in mean concentrations between Amchitka and Kiska. The concentrations of all radionuclides examined at Amchitka are similar to those of other uncontaminated Northern Hemisphere sites, and are lower than those reported for fishes and birds from the Irish Sea in the vicinity of the Sellafield nuclear reprocessing facility, an area with known contamination.     

Mitochondrial ferritin: a new player in iron metabolism

Mitochondrial ferritin (MtF) is a novel H-type ferritin encoded by an intronless gene on chromosome 5q23.1. The protein is synthesized as a precursor of about 30 kDa that is targeted to mitochondria by a leader sequence of 60 amino acids. This leader is proteolytically removed inside the mitochondria and the resulting 22 kDa subunit forms typical ferritin shells. These shells have ferroxidase activity and are therefore likely to sequester potentially harmful free iron. However, this may be a limited function since MtF has a very restricted tissue expression. High amounts are found in testis but only very low levels are found in iron storage organs. The levels of MtF appear to correlate more with mitochondrial abundance than with iron metabolism. MtF does not seem to be an obligatory intermediate in transfer of free iron to heme and other iron compounds in mitochondria. However, its level increases dramatically in sideroblastic anemia when heme synthesis is disrupted. This increased synthesis does not appear to involve the classical translational control since MtF mRNA lacks an apparent iron response element. In transfected HeLa cells added iron is incorporated as quickly into MtF as into cytosolic ferritin. In addition, increased levels of MtF cause a redistribution of iron from cytosol to mitochondria and this effect is enhanced by iron chelation. Thus high levels of MtF result in an iron deficient phenotype in cytosol with decreased expression of ferritin and increased expression of transferrin receptor. This avidity for iron may explain why MtF levels are maintained at low levels in most normal cells. The regulation of MtF expression and possible therapeutic applications of MtF in neurological disorders involving increased iron deposition are topics for future research.     

Rekonstruktion des Au?enbandapparats mittels Kniebeugesehnentransplantat bei chronischer Au?enbandinstabilit?t des OSG

Objective

Reconstruction of the anterior talofibular (ATFL) and calcaneofibular (CFL) ligament in patients with chronic lateral ankle instability.

Indications

Symptomatic chronic lateral ankle instability.

Contraindications

Bony malalignment, advanced arthritic changes of the ankle joint, diabetic foot syndrome.

Surgical technique

Reconstruction of the ATFL and CFL with a free gracilisor or semitendinosus tendon graft through a V-shaped tunnel at the insertion site of the ATFL on the talar neck as well as a transfibular tunnel directed anterior to posterior through the fibula tip to a blind ending tunnel in the calcaneus at the insertion site of the CFL. Insertion of the graft through the talar tunnel, passing both graft ends through the fibular tunnel to the calcaneus. Fixation with a bioabsorbable screw.

Postoperative management

Short leg cast for 10?C14?days and partial weight-bearing. Afterwards ankle brace for 6?weeks and functional physical therapy.

Results

From December 2003 to August 2005, reconstruction of the ATFL and CFL with a hamstring tendon autograft was performed in 20 patients with chronic lateral instability of the ankle joint. All patients were evaluated after a mean follow-up time of 1.8?years (15?C36?months). Clinical evaluation referred to the AOFAS score. Stress radiography was performed for objective assessment of lateral ankle stability. Postoperatively 19 of 20 patients reported good subjective stability with no further ankle sprains. The mean postoperative AOFAS score was 92 of 100 points (72?C100). Stress radiography showed a significant reduction of both lateral ankle instability and talar tilt.     

Protein C activators from snake venoms and their diagnostic use

Proteinases converting the zymogen protein C (PC) of vertebrates into activated PC have been detected in several snake venoms. Most PC activators have been purified from venom of snake species belonging to the genera of the Agkistrodon complex. Unlike the physiological, thrombin-catalyzed PC activation reaction which requires thrombomodulin as a cofactor, most snake venom activators directly convert the zymogen PC into the catalytically active form which can easily be determined by means of coagulation or chromogenic substrate techniques. Due to this feature, the fast-acting PC activator Protac from Agkistrodon contortrix contortrix (southern copperhead snake) venom has found a broad application in diagnostic practice for the determination of disorders in the PC pathway. Recently, screening assays for the PC pathway have been introduced, based on the observation that the PC pathway is probably the most important physiological barrier against thrombosis.     

The Relationship Between Cortical Excitability and Pain Catastrophizing in Myofascial Pain

Pain catastrophizing regularly occurs in chronic pain patients. It has been suggested that pain catastrophizing is a stable, person-based construct. These findings highlight the importance of investigating catastrophizing in conceptualizing specific approaches for pain management. One important area of investigation is the mechanism underlying pain catastrophizing. Therefore, this study explored the relationship between a neurophysiological marker of cortical excitability, as assessed by transcranial magnetic stimulation, and catastrophizing, as assessed by the Brazilian Portuguese Pain Catastrophizing Scale, in patients with chronic myofascial pain syndrome. The Pain Catastrophizing Scale is a robust questionnaire used to examine rumination, magnification and helplessness that are associated with the experience of pain. We include 24 women with myofascial pain syndrome. The Brazilian Portuguese Pain Catastrophizing Scale and cortical excitability were assessed. Functional and behavioral aspects of pain were evaluated with a version of the Profile of Chronic Pain scale and by multiple pain measurements (eg, pain intensity, pressure pain threshold, and other quantitative sensory measurements). Intracortical facilitation was found to be significantly associated with pain catastrophizing (β = .63, P = .001). Our results did not suggest that these findings were influenced by other factors, such as age or medication use. Furthermore, short intracortical inhibition showed a significant association with pressure pain threshold (β = .44, P = .04). This study elaborates on previous findings indicating a relationship between cortical excitability and catastrophizing. The present findings suggest that glutamatergic activity may be associated with mechanisms underlying pain catastrophizing; thus, the results highlight the need to further investigate the neurophysiological mechanisms associated with pain and catastrophizing.     

An automated tester for evaluation of pacemaker battery performance and reliability

Four- and 5-year-old rechargeable batteries continue to function normally after real time, high-drain, animal implantation pacemaker and body temperature bench tests. An automated battery test system with four major functions: (a) biological environmental simulation, (b) battery discharge-recharge cycling, (c) data collection and recording, and (d) failure warning and diagnosis has been designed and built. Accelerated tests on over 100 rechargeable batteries have consistently simulated over 16 years of pacemaking. Hermetically sealed, rechargeable pacemakers that will run for $\text{3}\text{1}\text{2}$ years without recharging are now undergoing chronic animal implantation. Units for clinical testing are under construction.