Release of corrosion products from amalgam in phosphate containing solutions

Abstract— The effect of phosphate concentration on corrosion was compared for two types of amalgam: a conventional alloy (ANA 68) and a high-Cu admixed alloy (Dispersalloy). The test specimens were stored for 4 months in electrolytes containing 85 mM NaCl and 85 mM NaCl with 2.5, 10, or 100 mM phosphate buffer respectively. The solutions were renewed each month and analyzed for Cu, Zn, Sn, Hg, and Ag in an atomic absorption spectrophotometer. The surfaces and cross-sections of the specimens were studied in a scanning electron microscope (SEM) with an energy dispersive detector (EDAX). The corrosion products, mainly Sn-compounds, at the surface of the amalgams were less in the solutions containing high concentrations of phosphate. In cross-section subsurface corrosion of the high-Cu amalgam was observed especially in specimens immersed in the NaCl solution without phosphate. The conventional amalgam showed surface corrosion only. The decrease in release of elements with time from the conventional amalgam in all the experimental solutions might indicate passivation. For the high-Cu amalgam the release of elements increased with time, except for Cu and Sn in the solution with 100 mM phosphate, indicating that phosphate inhibits corrosion of the Cu-Sn-phases. Release of corrosion products from the high-Cu amalgam was more dependent on the presence of phosphate than the conventional amalgam.     

Developmental Toxicity Evaluation of Ethylene Glycol by Gavage in New Zealand White Rabbits

Artificially inseminated New Zealand white (NZW) rabbits wereadministered ethylene glycol (EG) by gavage on Gestational Days(GD) 6 through 19 at doses of 0, 100, 500, 1000, or 2000 mg/kg/day,with 23–24 inseminated animals per group. Clinical signswere recorded and water consumption was measured daily; doeswere weighed on GD 0, 6–19, 25, and 30. At necropsy (GD30), maternal liver, kidney, and gravid uterine weights wererecorded. Histopathologic examination was performed on kidneysfrom 10 does/dose and for all unscheduled deaths. Ovarian corporalutea were counted and uterine implantation sites (total sites,resorptions, dead and live fetuses) were recorded. All livefetuses were weighed, sexed, and examined for external, visceral,and skeletal malformations and variations. EG resulted in profoundmaternal toxicity at 2000 mg/kg/day (42% mortality; three earlydeliveries and one spontaneous abortion) associated with renalpathology and unaccompanied by any other indicators of maternaltoxicity. Renal lesions at 2000 mg/kg/day involved the corticalrenal tubules and included intraluminal oxalate crystals, epithelialnecrosis, and tubular dilatation and degeneration. No dose-relatedmaternal toxicity occurred at 100–1000 mg/kg/day. Therewas no indication of developmental toxicity at any dose tested,including no effects on pre- or postimplantation loss, numberof fetuses, fetal body weight, or sex ratio (% male fetuses)per litter, and no evidence of teratogenicity. The "no observableadverse effect level" (NOAEL) for maternal toxicity was therefore1000 mg/kg/day and the NOAEL for developmental toxicity wasat least 2000 mg/kg/day in this study. The sensitivity of NZWrabbits relative to that of Sprague—Dawley rats and Swissmice for maternal and developmental toxicity from gavage administrationof EG during organogenesis can be determined for maternal toxicity:rabbits>mice>rats, and for developmental toxicity, mice>>rats >> rabbits.     

RELATIONSHIPS BETWEEN GRIEF AND FAMILY SYSTEM CHARACTERISTICS: A CROSS LAGGED LONGITUDINAL ANALYSIS

The present study explored the question of whether the grief process affects the characteristics of relationships within the family system or, alternatively, whether family characteristics affect the experience of grief symptoms. Sixty-one people who had recently experienced the death of a parent (82%) or spouse (18%) completed a questionnaire to assess their current grief symptomatology and characteristics of the relationships within their family 4-5 weeks after the death, and again six months later. Results from cross-lagged panel analyses suggested that increased expression of family affect, family cohesion, and both higher total Family Environment Scale and Family Assessment Measure Version III General scores were predictors of fewer grief symptoms over time. Overall, these results suggest that knowledge of a variety of aspects of a family's structure and process shortly after a death may help predict the later grief of the loss of a loved one.     

The first report of a patient with interrupted inferior vena cava,multiple post-renal veins and azygos-hemiazygos continuation

The first case of a patient with interrupted inferior vena cava, four post-renal veins and an azygoshemiazygos continuation is presented. The complicated anomalies were omphalocele and atrial septal defect. Cine-magnetic resonance imaging and cardiac catheterization showed an anomalous retroaortic left innominate vein, azygos-hemiazygos continuation in the prerenal portion, arch formed renal vein in the renal portion and four embryonic vessels in the post-renal portion. Combination of these anomalies in the major venous system suggested that the inferior vena cava had failed to form and that the bilateral embryonic venous system, postcardinal and supracardinal veins persisted to be the systemic venous channels.     

Pace-Termination and Pacing for Prevention of Atrial Tachyarrhythmias: Results from a Multicenter Study with an Implantable Device for Atrial Therapy

INTRODUCTION: Patients with bradycardia requiring permanent pacing frequently suffer from additional atrial tachyarrhythmias (ATs). This study evaluated the safety and efficacy of atrial antitachycardia pacing (ATP) and the performance of pacing for AT prevention implemented into a new pacemaker. METHODS AND RESULTS: In patients with conventional indications for permanent pacing, an investigational DDDRP pacemaker (Medtronic AT500, model 7253) was implanted. The primary study objectives were to determine the safety of overall device functioning and its efficacy in terminating spontaneous AT. A secondary endpoint was to determine the reliability of AT detection. Pacemaker memory functions were used to analyze the impact of dedicated pacing algorithms on AT prevention. In 33 European and Canadian centers, 325 patients were enrolled (mean follow-up 2.3+/-1.3 months). Complication-free survival at 3 months was 88%. In 2,145 episodes stored with atrial electrograms, AT detection was confirmed in 97%. The algorithm for continuous overdrive pacing increased the percentage of atrial pacing to 97%. After ATP activation, 16,683 of 52,468 AT episodes were treated (120 patients). Of these, 8,903 episodes (53%) were terminated successfully by ATP. No proarrhythmic effect of preventive pacing or atrial ATP was observed. Preventive pacing algorithms increased the median percentage of atrial pacing from 62% to 97%. However, the number of AT/AF (atrial fibrillation) episodes (4.1 vs 4.1 per patient per day) and the time in AT/AF (13.7% vs 12.8%) was not significantly different before and after activation of preventive pacing. CONCLUSION: DDDRP pacing with a new system for AT therapy was safe and associated with successful pace-termination of AT in 53% of episodes. Preventive pacing and atrial ATP algorithms represent two new functions that can be implemented safely into pacemaker systems for nonpharmacologic treatment of ATs in patients requiring pacemaker therapy.     

From the brain to bad behaviour and back again: Neurocognitive and psychobiological mechanisms of driving while impaired by alcohol

Issues. Driving while impaired by alcohol (DWI) is responsible for substantial mortality and injury. Significant gaps in our understanding of DWI re‐offending, or recidivism, reduce our ability to practically assess recidivism probability and to match interventions to individual risk profiles. These shortcomings reflect the baffling heterogeneity in the DWI population and the limited focus of much existing DWI recidivism research to psychosocial, psychological and substance use correlates. Approach. This narrative review summarises the evidence for the contribution of neurocognitive and psychobiological mechanisms to DWI behaviour and recidivism. Given the nascent nature of this literature, insight into the putative contribution of these mechanisms to DWI is also drawn from other experimental literatures, particularly those on alcohol use disorders and cognitive and behavioural neuroscience. Key Findings. Alcohol‐related neurotoxicity and dysregulation of hypothalamic–pituitary–adrenal axis and serotonergic systems may underlie certain offender characteristics consistently correlated with heightened DWI risk, persistence and intervention resistance. Their markers are less vulnerable to sources of bias than subjective psychosocial indices and are more far‐reaching than alcohol abuse in explaining DWI behaviour and recidivism. Implications. The investigation of neurocognitive and psychobiological mechanisms in DWI research is a promising avenue for discerning clinically meaningful subgroups within the DWI population. This can lead to research and development in alternative assessment and more targeted intervention technologies. Conclusion. Multidimensional research in DWI and recidivism offers novel avenues for increasing road safety.[Brown TG, Ouimet MC, Nadeau L, Gianoulakis C, Lepage M, Tremblay J, Dongier M. From the brain to bad behaviour and back again: Neurocognitive and psychobiological mechanisms of driving while impaired by alcohol. Drug Alcohol Rev 2009;28:406–418]