ANZ JOURNAL OF SURGERY, Issue 9 2007
Christopher J. Wall
Background: Acute compartment syndrome is a serious and not uncommon complication of limb trauma. The condition is a surgical emergency and is associated with significant morbidity if not diagnosed promptly and treated effectively. Despite the urgency of effective management to minimize the risk of adverse outcomes, there is currently little consensus in the published reports as to what constitutes best practice in the management of acute limb compartment syndrome. Methods: A structured survey was sent to all currently practising orthopaedic surgeons and accredited orthopaedic registrars in Australia to assess their current practice in the management of acute, traumatic compartment syndrome of the leg. Questions were related to key decision nodes in the management process, as identified in a literature review. These included identification of patients at high risk, diagnosis of the condition in alert and unconscious patients, optimal timeframe and technique for carrying out a fasciotomy and management of fasciotomy wounds. Results: A total of 264 valid responses were received, a response rate of 29% of all eligible respondents. The results indicated considerable variation in management of acute compartment syndrome of the leg, in particular in the utilization of compartment pressure measurement and the appropriate pressure threshold for fasciotomy. Of the 78% of respondents who regularly measured compartment pressure, 33% used an absolute pressure threshold, 28% used a differential pressure threshold and 39% took both into consideration. Conclusions: There is variation in the management of acute, traumatic compartment syndrome of the leg in Australia. The development of evidence-based clinical practice guidelines may be beneficial. [source]

Acute and Chronic Oral Magnesium Supplementation: Effects on Endothelial Function, Exercise Capacity, and Quality of Life in Patients With Symptomatic Heart Failure

CONGESTIVE HEART FAILURE, Issue 1 2006
Johanna C. Fuentes MD
Endothelial dysfunction is an important pathophysiologic mechanism in the progression of heart failure. The objective of the present study was to determine the effects of acute and chronic oral magnesium supplementation on endothelial function in patients with symptomatic heart failure. Twenty-two symptomatic chronic heart failure patients were randomized to receive 800 mg oral magnesium oxide daily or placebo for 3 months. Data collected included large and small arterial elasticity/compliance, hemodynamic parameters, exercise capacity, and quality-of-life score at baseline, 1 week, and 3 months. Patients who received magnesium had improved small arterial compliance at 3 months from baseline compared with placebo. This study suggests that chronic supplementation with oral magnesium is well tolerated and could improve endothelial function in symptomatic heart failure patients. [source]

Mechanical Bridging to Improvement in Severe Acute ,Nonischemic, Nonmyocarditis' Heart Failure

CONGESTIVE HEART FAILURE, Issue 2 2004
O.H. Frazier MD
Improved myocardial function has been observed in patients with acute myocarditis who have had short-term support with a ventricular assist system. Additionally, a limited number of patients with nonischemic cardiomyopathy have undergone successful device explantation after their myocardial function improved during ventricular assist system support. The authors present their experience with four patients who had acute, severe heart failure without coronary artery disease or biopsy-proven myocarditis. After receiving prolonged ventricular assist system support, all four patients had significantly improved left ventricular function, returning to New York Heart Association functional class I without inotropic therapy. In each case, dobutamine stress echocardiography and invasive hemodynamic tests were performed to confirm improvement of cardiac function before device explantation was undertaken. In all four cases, device explantation was followed by early successful maintenance of left ventricular function. These cases reveal a unique clinical syndrome that may be successfully treated with early institution of ventricular assist system support followed by explantation after myocardial recovery. [source]

Shoe contact dermatitis from dimethyl fumarate: clinical manifestations, patch test results, chemical analysis, and source of exposure

CONTACT DERMATITIS, Issue 5 2009
Ana Giménez-Arnau
Background: The methyl ester form of fumaric acid named dimethyl fumarate (DMF) is an effective mould-growth inhibitor. Its irritating and sensitizing properties were demonstrated in animal models. Recently, DMF has been identified as responsible for furniture contact dermatitis in Europe. Objective: To describe the clinical manifestations, patch test results, shoe chemical analysis, and source of exposure to DMF-induced shoe contact dermatitis. Patients, Materials, and Methods: Patients with suspected shoe contact dermatitis were studied in compliance with the Declaration of Helsinki. Patch test results obtained with their own shoe and the European baseline series, acrylates and fumaric acid esters (FAE), were recorded according to international guidelines. The content of DMF in shoes was analysed with gas chromatography and mass spectrometry. Results: Acute, immediate irritant contact dermatitis and non-immunological contact urticaria were observed in eight adults and two children, respectively. All the adult patients studied developed a delayed sensitization demonstrated by a positive patch testing to DMF , 0.1% in pet. Cross-reactivity with other FAEs and acrylates was observed. At least 12 different shoe brands were investigated. The chemical analysis from the available shoes showed the presence of DMF. Conclusion: DMF in shoes was responsible for severe contact dermatitis. Global preventive measures for avoiding contact with DMF are necessary. [source]

Effect of treatment delay upon pulp and periodontal healing of traumatic dental injuries , a review article

DENTAL TRAUMATOLOGY, Issue 3 2002
J.O. Andreasen
Abstract,,,Based on an analysis of the literature concerning parameters influencing the prognosis of traumatic dental injuries, few studies were found to have examined possible relationships between treatment delay and pulpal and periodontal ligament healing complications. It has been commonly accepted that all injuries should be treated on an emergency basis, for the comfort of the patient and also to reduce wound healing complications. For practical and especially economic reasons, various approaches can be selected to fulfill such a demand, such as acute treatment (i.e. within a few hours), subacute (i.e. within the first 24 h), and delayed (i.e. after the first 24 h). In this survey the consequences of treatment delay on pulpal and periodontal healing have been analyzed for the various dental trauma groups. Applying such a treatment approach to the various types of injuries, the following treatment guidelines can be recommended, based on our present rather limited knowledge of the effect of treatment delay upon wound healing. Crown and crown/root fractures: Subacute or delayed approach. Root fractures: Acute or subacute approach. Alveolar fractures: Acute approach (evidence however questionable). Concussion and subluxation: Subacute approach. Extrusion and lateral luxation: Acute or subacute approach (evidence however questionable). Intrusion: Subacute approach (evidence however questionable). Avulsion: If the tooth is not replanted at the time of injury, acute approach; otherwise subacute. Primary tooth injury: Subacute approach, unless the primary tooth is displaced into the follicle of the permanent tooth or occlusal problems are present; in the latter instances, an acute approach should be chosen. These treatment guidelines are based on very limited evidence from the literature and should be revised as soon as more evidence about the effect of treatment delay becomes available. [source]

Neural agrin increases postsynaptic ACh receptor packing by elevating rapsyn protein at the mouse neuromuscular synapse

DEVELOPMENTAL NEUROBIOLOGY, Issue 9 2008
Jennifer Brockhausen
Abstract Fluorescence resonance energy transfer (FRET) experiments at neuromuscular junctions in the mouse tibialis anterior muscle show that postsynaptic acetylcholine receptors (AChRs) become more tightly packed during the first month of postnatal development. Here, we report that the packing of AChRs into postsynaptic aggregates was reduced in 4-week postnatal mice that had reduced amounts of the AChR-associated protein, rapsyn, in the postsynaptic membrane (rapsyn+/, mice). We hypothesize that nerve-derived agrin increases postsynaptic expression and targeting of rapsyn, which then drives the developmental increase in AChR packing. Neural agrin treatment elevated the expression of rapsyn in C2 myotubes by a mechanism that involved slowing of rapsyn protein degradation. Similarly, exposure of synapses in postnatal muscle to exogenous agrin increased rapsyn protein levels and elevated the intensity of anti-rapsyn immunofluorescence, relative to AChR, in the postsynaptic membrane. This increase in the rapsyn-to-AChR immunofluorescence ratio was associated with tighter postsynaptic AChR packing and slowed AChR turnover. Acute blockade of synaptic AChRs with ,-bungarotoxin lowered the rapsyn-to-AChR immunofluorescence ratio, suggesting that AChR signaling also helps regulate the assembly of extra rapsyn in the postsynaptic membrane. The results suggest that at the postnatal neuromuscular synapse agrin signaling elevates the expression and targeting of rapsyn to the postsynaptic membrane, thereby packing more AChRs into stable, functionally-important AChR aggregates. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008 [source]

Noncorrelating Pap tests and cervical biopsies: Histological predictors of subsequent correlation

DIAGNOSTIC CYTOPATHOLOGY, Issue 5 2005
Nancy E. Joste M.D.
Abstract Lack of correlation between dysplastic cervicovaginal Papanicolaou (Pap) tests and subsequent cervical biopsies raises the concern that a significant squamous intraepithelial lesion (SIL) may go unconfirmed. Additional tissue sections of cervical biopsies may detect SILs after noncorrelation on initial sections. Complete step sectioning of paraffin blocks was undertaken on 111 noncorrelating biopsy specimens from 95 patients and selected slides were reviewed for the presence of SIL. The initial negative biopsy slides were evaluated for four histological features: chronic cervicitis, acute cervicitis, mucosal erosion, and squamous atypia. Twenty-seven biopsies (24.3%) demonstrated the presence of a SIL in deeper levels. The presence of squamous atypia was significantly associated with the presence of dysplasia deeper in the block (P < 0.002). Acute and chronic cervicitis was seen roughly equally. Additional tissue levels are a productive way of confirming SILs, and squamous atypia allows a refined selection of negative cervical biopsies most likely to reveal an SIL on review of deeper levels. Diagn. Cytopathol. 2005;32:310,314. © 2005 Wiley-Liss, Inc. [source]

Heat or Cold Packs for Neck and Back Strain: A Randomized Controlled Trial of Efficacy

ACADEMIC EMERGENCY MEDICINE, Issue 5 2010
Gregory Garra DO
Abstract Objectives:, Acute back and neck strains are very common. In addition to administering analgesics, these strains are often treated with either heat or cold packs. The objective of this study was to compare the analgesic efficacy of heat and cold in relieving pain from back and neck strains. The authors hypothesized that pain relief would not differ between hot and cold packs. Methods:, This was a randomized, controlled trial conducted at a university-based emergency department (ED) with an annual census of 90,000 visits. ED patients >18 years old with acute back or neck strains were eligible for inclusion. All patients received 400 mg of ibuprofen orally and then were randomized to 30 minutes of heating pad or cold pack applied to the strained area. Outcomes of interest were pain severity before and after pack application on a validated 100-mm visual analog scale (VAS) from 0 (no pain) to 100 (worst pain), percentage of patients requiring rescue analgesia, subjective report of pain relief on a verbal rating scale (VRS), and future desire for similar packs. Outcomes were compared with t-tests and chi-square tests. A sample of 60 patients had 80% power to detect a 15-mm difference in pain scores. Results:, Sixty patients were randomized to heat (n = 31) or cold (n = 29) therapy. Mean (±standard deviation [SD]) age was 37.8 (±14.7) years, 51.6% were female, and 66.7% were white. Groups were similar in baseline patient and pain characteristics. There were no differences between the heat and cold groups in the severity of pain before (75 mm [95% CI = 66 to 83] vs. 72 mm [95% CI = 65 to 78]; p = 0.56) or after (66 mm [95% CI = 57 to 75] vs. 64 mm [95% CI = 56 to 73]; p = 0.75) therapy. Pain was rated better or much better in 16/31 (51.6%) and 18/29 (62.1%) patients in the heat and cold groups, respectively (p = 0.27). There were no between-group differences in the desire for and administration of additional analgesia. Twenty-five of 31 (80.6%) patients in the heat group and 22 of 29 (75.9%) patients in the cold group would use the same therapy if injured in the future (p = 0.65). Conclusions:, The addition of a 30-minute topical application of a heating pad or cold pack to ibuprofen therapy for the treatment of acute neck or back strain results in a mild yet similar improvement in the pain severity. However, it is possible that pain relief is mainly the result of ibuprofen therapy. Choice of heat or cold therapy should be based on patient and practitioner preferences and availability. ACADEMIC EMERGENCY MEDICINE 2010; 17:484,489 © 2010 by the Society for Academic Emergency Medicine [source]

Acute and chronic toxicity of mercury to early life stages of the rainbow mussel, Villosa iris (Bivalvia: Unionidae)

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2005
Theodore W. Valenti
Abstract Mercury (Hg) contamination is receiving increased attention globally because of human health and environmental concerns. Few laboratory studies have examined the toxicity of Hg on early life stages of freshwater mussels, despite evidence that glochidia and juvenile life stages are more sensitive to contaminants than adults. Three bioassays (72-h acute glochidia, 96-h acute juvenile, and 21-d chronic juvenile toxicity tests) were conducted by exposing Villosa iris to mercuric chloride salt (HgCl2). Glochidia were more sensitive to acute exposure than were juvenile mussels, as 24-, 48-, and 72-h median lethal concentration values (LC50) for glochidia were >107, 39, and 14 ,g Hg/L, respectively. The 24-, 48-, 72-, and 96-h values for juveniles were 162, 135, 114, and 99 ,g Hg/L, respectively. In the chronic test, juveniles exposed to Hg treatments ,8 ,g/L grew significantly less than did control organisms. The substantial difference in juvenile test endpoints emphasizes the importance of assessing chronic exposure and sublethal effects. Overall, our study supports the use of glochidia as a surrogate life stage for juveniles in acute toxicity tests. However, as glochidia may be used only in short-term tests, it is imperative that an integrated approach be taken when assessing risk to freshwater mussels, as their unique life history is atypical of standard test organisms. Therefore, we strongly advocate the use of both glochidia and juvenile life stages for risk assessment. [source]

Acute and chronic toxicity of imidazolium-based ionic liquids on Daphnia magna

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2005
Randall J. Bernot
Abstract Room-temperature ionic liquids (ILs) are considered to be green chemicals that may replace volatile organic solvents currently used by industry. However, IL effects on aquatic organisms and ecosystems are currently unknown. We studied the acute effects of imidazolium-based ILs on survival of the crustacean Daphnia magna and their chronic effects on number of first-brood neonates, total number of neonates, and average brood size. Lethal concentrations of imidazolium ILs with various anions (X,) ranged from a median lethal concentration (LC50) of 8.03 to 19.91 mg L,1, whereas salts with a sodium cation (Na+ X,) were more than an order of magnitude higher (NaPF6 LC50, 9,344.81 mg L,1; NaBF4 LC50, 4765.75 mg L,1). Thus, toxicity appeared to be related to the imidazolium cation and not to the various anions (e.g., CI,, Br,, PF,6, and BF,4). The toxicity of imidazolium-based ILs is comparable to that of chemicals currently used in manufacturing and disinfection processes (e.g., ammonia and phenol), indicating that these green chemicals may be more harmful to aquatic organisms than current volatile organic solvents. We conducted 21-d chronic bioassays of individual D. magna exposed to nonlethal IL concentrations at constant food-resource levels. Daphnia magna produced significantly fewer total neonates, first-brood neonates, and average neonates when exposed to lower concentrations (0.3 mg L,1) of imidazolium-based ILs than in the presence of Na-based salts at higher concentrations (400 mg L,1). Such reductions in the reproductive output of Daphnia populations could cascade through natural freshwater ecosystems. The present study provides baseline information needed to assess the potential hazard that some ILs may pose should they be released into freshwater ecosystems. [source]

Acute and chronic toxicity of five selective serotonin reuptake inhibitors in Ceriodaphnia dubia

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2004
Theodore B. Henry
Abstract Contamination of surface waters by pharmaceutical chemicals has raised concern among environmental scientists because of the potential for negative effects on aquatic organisms. Of particular importance are pharmaceutical compounds that affect the nervous or endocrine systems because effects on aquatic organisms are possible at low environmental concentrations. Selective serotonin reuptake inhibitors (SSRIs) are drugs used to treat clinical depression in humans, and have been detected in low concentrations in surface waters. In this investigation, the acute and chronic toxicity of five SSRIs (fluoxetine, Prozac®; fluvoxamine, Luvox®; paroxetine, Paxil®; citalopram, Celexa®; and sertraline, Zoloft®) were evaluated in the daphnid Ceriodaphnia dubia. For each SSRI, the 48-h median lethal concentration (LC50) was determined in three static tests with neonate C. dubia, and chronic (8-d) tests were conducted to determine no-observable-effect concentrations (NOEC) and lowest-observable-effect concentrations (LOEC) for reproduction endpoints. The 48-h LC50 for the SSRIs ranged from 0.12 to 3.90 mg/L and the order of toxicity of the compounds was (lowest to highest): Citalopram, fluvoxamine, paroxetine, fluoxetine, sertraline. Mortality data for the 8-d chronic tests were similar to the 48-h acute data. The SSRIs negatively affected C. dubia reproduction by reducing the number of neonates per female, and for some SSRIs, by reducing the number of broods per female. For sertraline, the most toxic SSRI, the LOEC for the number of neonates per female was 0.045 mg/L and the NOEC was 0.009 mg/L. Results indicate that SSRIs can impact survival and reproduction of C. dubia; however, only at concentrations that are considerably higher than those expected in the environment. [source]

Acute and chronic toxicity of nickel to marine organisms: Implications for water quality criteria

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2002
John W. Hunt
Abstract Acute and chronic toxicity tests were conducted to determine the effects of nickel on three U.S. west coast marine species: a fish (the topsmelt, Atherinops affinis), a mollusk (the red abalone, Haliotis rufescens), and a crustacean (the mysid, Mysidopsis intii). The 96-h median lethal concentration (LC50) for topsmelt was 26,560 mg/L, and the chronic value for the most sensitive endpoint in a 40-d exposure was 4,270 mg/L. The median effective concentration (EC50) for 48-h abalone larval development was 145.5 ,g/L, and the chronic value for juvenile growth in a 22-d exposure through larval metamorphosis was 26.43 mg/L. The mysid 96-h LC50 was 148.6 ,g/L, and the chronic value for the most sensitive endpoint in a 28-d, whole life-cycle exposure was 22.09 ,g/L. The abalone and mysid acute values were lower than other values available in the literature. Acute-tochronic ratios for nickel toxicity to the three species were 6.220, 5.505, and 6.727, respectively, which were similar to the only other available saltwater value of 5.478 (for Americamysis [Mysidopsis] bahia) and significantly lower than the existing values of 35.58 and 29.86 for freshwater organisms. Incorporation of data from the present study into calculations for water quality criteria would lower the criterion maximum concentration and raise the criterion continuous concentration for nickel. [source]

Acute and chronic toxicity of nitrate to fathead minnows (Pimephales promelas), ceriodaphnia dubia, and Daphnia magna

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2000
George Scott
Abstract Increasing concentrations of nitrate in surface water and groundwater are becoming a worldwide concern, yet little information has been published on toxicity of nitrate to common organisms used for toxicity testing. The acute and chronic toxicity of nitrate (NO3 -N) to Ceriodaphnia dubia, Daphnia magna, and Pimephales promelas was investigated in 48-h to 17-d laboratory exposures. The 48-h median lethal concentration (LC50) of nitrate to C. dubia and D. magna neonates was 374 mg/L NO3 -N and 462 mg/L NO3 -N. The no-observed-effect concentration (NOEC) and the lowest-observed-effect concentration (LOEC) for neonate production in C. dubia were 21.3 and 42.6 mg/L NO3 -N, respectively. The NOEC and LOEC values for neonate production in D. magna were 358 and 717 mg/L NO3 -N, respectively. The 96-h LC50 for larval fathead minnows (P. promelas) was 1, 341 mg/L NO3 -N. The NOEC and LOEC for 7-d larval and 11-d embryo-larval growth tests were 358 and 717 mg/L NO3 -N, respectively. Additional exposure of breeding P. promelas and their fertilized eggs to nitrate did not increase susceptibility further. The LC50 values for all species tested were above ambient concentrations of nitrate reported for surface water. However, the LOEC for C. dubia was within the range of concentrations that could be found in streams draining areas under extensive agricultural cultivation. [source]

Structure,activity relationships for acute and chronic toxicity of alcohol ether sulfates

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2000
Scott D. Dyer
Abstract Acoholethersulfates(AES)areanionicsurfactantscommonlyusedinconsumerproducts. Commercial AES alkyl chain lengths range from C12 to C18, with ethoxylate (EO) units ranging from 1 to 5. Alkyl sulfate is a special case of AES with no EO units. Acute and chronic toxicity tests using Ceriodaphnia dubia via a novel flowthrough method were conducted with 18 AES compounds to derive SARs for effects assessment. In general, acute toxicity (48-h LC50) increased with increased alkyl carbon chain length and decreased with increased numbers of EO units. Parabolic structure,chronic (7-d) toxicity relationships were observed for endpoints such as the no-observed-effect concentration, lowest-observed-effect concentration, maximum acceptable toxicant concentration, EC20, and EC50. A linear relationship of the fractional negative-charged surface area (FNSA-3) with acute toxicity was also determined. FNSA-3 refers primarily to the polar head group of AES and secondarily to the alkyl chain. Seventy percent of the variance in the chronic data was addressed with a quadratic equation relating toxicity to alkyl chain length and EO units. Alternatively, the molecular descriptors FNSA-3 and S3P (3,p, which is the simple, third-order path index) were also found to address most of the data nonlinearity. A chronic test conducted with a mixture of four AES components indicated additivity, leading to the support of the performance of an effects assessment of AES as a mixture. [source]

Diphenhydramine as a Protective Agent in a Rat Model of Acute, Lethal Organophosphate Poisoning

ACADEMIC EMERGENCY MEDICINE, Issue 12 2002
Steven B. Bird MD
Objective: To evaluate the effects of diphenhydramine chloride (DPH) on mortality in a rat model of acute, severe organophosphate poisoning (OP).Methods: Wistar rats (n = 40) were randomized to pretreatment with either normal saline (controls), 5 mg/kg atropine, 3 mg/kg DPH, 15 mg/kg DPH, or 30 mg/kg DPH given as a single intramuscular injection 5 minutes prior to a subcutaneous injection of 25 mg/kg dichlorvos (n = 8 per group). The primary endpoint was 10-minute survival. Survival at 24 hours was a secondary endpoint. Comparison of survival rates between groups was carried out by ANOVA and the Student-Newman-Keuls test. Results: Dichlorvos exposure resulted in profound fasciculations within 2 minutes of injection in all cohorts. In controls, fasciculations were followed by respiratory arrest within 10 minutes (0% survival). The rats receiving atropine pre-treatment exhibited similar fasciculations (nicotinic effects) without subsequent respiratory arrest, resulting in a significant improvement in survival (88%, p < 0.001). The DPH-treated rats exhibited a significant dose-dependent reduction in mortality, with the 3 mg/kg, 15 mg/kg, and 30 mg/kg groups demonstrating 0%, 25%, and 100% survival, respectively. There was no additional mortality between 10 minutes and 24 hours in any group. There was no significant difference in survival between the high-dose DPH and the atropine groups. Conclusions: Diphenhydramine chloride significantly reduced mortality in rats with acute, severe dichlorvos exposure. [source]

Acute and long-term changes in the mesolimbic dopamine pathway after systemic or local single nicotine injections

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2002
R. Ferrari
Abstract We have examined several neurochemical and behavioural parameters related to the function of the mesolimbic dopamine (DA) pathway in animals treated with nicotine following three modes of drug administration, i.e. systemic intraperitoneal injection, intra-accumbens (Acb) infusion or intraventral tegmental area (intra-VTA) microinjection. The present modes of systemic, intra-Acb and intra-VTA nicotine administration elicited comparable acute increases in dialysate DA levels from the Acb. The increase in extracellular DA levels was paralleled by a significant enhancement of locomotion in a habituated environment in the case of systemic or intra-VTA nicotine administration, whereas unilateral or bilateral intra-Acb nicotine infusion was ineffective, showing that accumbal DA increase is not sufficient to elicit locomotion in this experimental paradigm. Intra-VTA, but not systemic or intra-Acb, nicotine administration caused a long-term (at least 24-h) increase in basal dialysate DA levels from the Acb. In addition, significant increases in tyrosine hydroxylase (TH) and GluR1 (but not dopamine transporter or NR1) mRNA levels in the VTA were detected 24 h after intra-VTA nicotine administration. Systemic nicotine injection caused only an increase in TH mRNA levels while intra-Acb infusion did not modify any of the mRNAs tested. The long-term increase in basal DA levels in the Acb and TH, and GluR1 mRNA levels in the VTA upon intra-VTA nicotine microinjection indicates that even a single nicotine injection can induce plastic changes of the mesolimbic DA pathway. [source]

Postoperative intensity-modulated radiation therapy for cancers of the paranasal sinuses, nasal cavity, and lacrimal glands: Technique, early outcomes, and toxicity,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2008
Bradford S. Hoppe MD
Abstract Background Our aim was to review Memorial Sloan-Kettering Cancer Center's experience with postoperative intensity-modulated radiotherapy (IMRT) for paranasal sinus, nasal cavity, and lacrimal gland cancer and report dosimetric measures, toxicity, and outcomes. Methods Between September 2000 and June 2006, 37 patients with paranasal sinus, nasal cavity, or lacrimal gland cancer underwent postoperative IMRT. Median values were as follows: prescription dose, 60 Gy (range, 50,70); PTVD95, 99% (range, 79,101%); optic nerve Dmax, 53 Gy (range, 2,54); optic chiasm Dmax, 51Gy (range, 2,55). Acute and late toxicities were scored by Radiation Therapy Oncology Group morbidity criteria. Results Median follow-up was 28 months. Two-year local progression,free and overall survivals were 75% and 80%. No early- or late-grade 3/4 radiation-induced ophthalmologic toxicity occurred. Conclusions Preliminary results show that adjuvant IMRT in these patients is feasible, allowed for excellent planning target volume (PTV) coverage, and minimized dose delivered to optic structures. Longer follow-up is warranted to assess the extent of late effects and outcomes. © 2008 Wiley Periodicals, Inc. Head Neck, 2008 [source]

Concomitant low-dose cisplatin and three-dimensional conformal radiotherapy for locally advanced squamous cell carcinoma of the head and neck: Analysis of survival and toxicity,

HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 3 2006
Harold Lau MD
Abstract Background. Our center sought to implement a simple chemoradiotherapy schedule for patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN) with minimal toxicity to achieve rates of overall survival comparable to other schedules. Methods. The chemoradiotherapy schedule consisted of daily radiation to 70 Gy over 7 weeks with concurrent cisplatin 20 mg/m2 during days 1 to 4 of weeks 1 and 5. Acute and late toxicities were recorded according to the Radiation Therapy Oncology Group (RTOG) and common toxicity criteria (CTC) grading. The overall, disease-specific, and locoregional recurrence,free survival were calculated using the STATA statistics package. Possible factors influencing these endpoints were analyzed. Results. Fifty-seven patients were treated, and 56 patients were evaluable for follow-up. Median follow-up of alive patients was 16.1 months. There was an 82% complete response rate to chemoradiotherapy. The 2-year Kaplan,Meier overall, disease-specific, and locoregional recurrence,free survival rates were 62%, 67%, and 63%. Acute grade 3 and 4 radiation toxicity was noted in 61% and 2%, respectively. Grade 3 or 4 hematologic toxicity was noted in 7% of patients. Factors influencing overall survival included: Karnofsky performance status, receiving more than 50% of planned chemotherapy, age, and initial hemoglobin level. Conclusion. This regimen is tolerable and achieves overall survival and locoregional control rates comparable to other chemoradiotherapy schedules. © 2005 Wiley Periodicals, Inc. Head Neck27: XXX,XXX, 2005 [source]

Problem of Distinguishing False-Positive Tests from Acute or Transient Helicobacter pylori Infections

HELICOBACTER, Issue 2 2006
Zhannat Z. Nugalieva
Abstract Background:, Reliable detection of acute Helicobacter pylori infections remains problematic. The high prevalence of false-positive non-invasive tests in low H. pylori prevalence populations makes identification of acute and transient infections difficult. Methods:, We explored the use of serum pepsinogens (PG) for diagnosis of acute infection in patients following H. pylori challenge such that the onset of the infection was known. We then compared those findings to a group of children with presumed acute infections defined as a positive urea breath test (UBT) and negative IgG serology. Results:, We examined the pattern and calculated cut-off values of PG levels in 18 adult volunteers with known acute H. pylori infection. We then compared the results with sera from nine symptomatic children with presumed acute H. pylori infection and a matched control group of nine children who did not meet criteria for acute H. pylori infection. In acute infection, both PGI and II levels increased following H. pylori infection reaching a peak by 2 weeks post-infection. The frequency of a positive test defined as a value > mean +2 SD was 17, 71, and 94% at week 1, 2, and 4 post-infection, respectively. Only one child with presumed acute H. pylori infection had an elevated serum PGI and one had an elevated PGII. Five of the children had follow-up UBTs and four were negative consistent with the diagnosis of false-positive UBT. H. pylori infection was confirmed in the child with an elevated PGI level. Conclusions:, These data suggest that a single positive noninvasive test in populations of low prevalence is most likely a false-positive result. This suggests that a single positive test requires confirmation preferably using a test that measures a different parameter (e.g., UBT confirmed by stool antigen test). It appears that most "transient"H. pylori infections are diagnosed on the basis of false-positive tests. PG levels are possible candidates as the confirmatory test. [source]

Antibodies Against Hepatitis C Virus,Like Particles and Viral Clearance in Acute and Chronic Hepatitis C

HEPATOLOGY, Issue 3 2000
Thomas F. Baumert M.D.
We recently described the efficient assembly of hepatitis C virus (HCV) structural proteins into HCV-like particles (HCV-LPs) in insect cells. These noninfectious HCV-LPs have similar morphologic and biophysical properties as putative virions isolated from HCV-infected humans and can induce a broadly directed immune response in animal models. The HCV envelope proteins of HCV-LPs are presumably presented in a native, virion-like conformation and may therefore interact with antienvelope antibodies directed against conformational epitopes. In this study, HCV-LPs were used as capture antigens in an enzyme-linked immunosorbent assay (ELISA) to detect and quantify antibodies against HCV structural proteins in patients with acute and chronic hepatitis C. High titers of anti,HCV-LP antibodies were detected in patients chronically infected with HCV genotypes 1 to 6. In contrast to individuals with chronic hepatitis C, patients with acute self-limited hepatitis C displayed only a transient and weak seroreactivity against HCV-LPs. Patients with chronic HCV infection successfully treated with interferon demonstrated a gradual decline of anti,HCV-LP titers during or subsequent to viral clearance. Sustained interferon responders were characterized by significantly higher pretreatment levels of anti,HCV-LP antibodies as compared with nonresponders (P = .0001). In conclusion, HCV infection is associated with limited humoral immunity against the envelope proteins present on the HCV-LPs. An HCV-LP,based ELISA may be a useful diagnostic tool to distinguish acute hepatitis C from chronic HCV infection with exacerbation, and to predict viral clearance in response to interferon. [source]

Healthcare Costs of Acute and Chronic Pain Associated with a Diagnosis of Herpes Zoster

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2007
Robert H. Dworkin PhD
OBJECTIVES: To determine the healthcare costs of acute and chronic pain associated with herpes zoster. DESIGN: Retrospective cohort analysis. SETTING: Inpatient and outpatient care. PARTICIPANTS: Patients were selected from Medicare, commercial insurance, and Medicaid claims databases if they had a diagnosis of herpes zoster or postherpetic neuralgia (PHN) or were prescribed analgesics after a diagnosis of herpes zoster (possible PHN) and were matched to controls for demographic and clinical factors using propensity scores. MEASUREMENTS: One-year excess healthcare expenditures attributable to herpes zoster pain or PHN were calculated for inpatient, outpatient, and prescription drug services. RESULTS: For the Medicare cohort, the average excess cost per patient was $1,300 in the year after a diagnosis of herpes zoster with 30 days or fewer of analgesic use and ranged from $2,200 to $2,300 per patient with PHN or possible PHN. Patients with possible PHN were 53% more prevalent than patients with PHN in the Medicare cohort and accounted for half of all excess expenditures. Findings were similar in the younger cohorts with commercial insurance and Medicaid except that costs attributable to PHN and possible PHN were higher, and patients with possible PHN were three to five times as prevalent as patients with PHN. CONCLUSION: Healthcare costs associated with PHN were substantially greater than those associated with herpes zoster pain that resolved within 30 days. The data suggest that as many as 80% of patients with PHN may not be diagnosed with PHN and that these patients account for at least half of PHN expenditures. [source]

Pulmonary responses and recovery following single and repeated inhalation exposure of rats to polymeric methylene diphenyl diisocyanate aerosols

JOURNAL OF APPLIED TOXICOLOGY, Issue 6 2002
Joanne D. Kilgour
Abstract Acute and repeated inhalation exposures (for 28 days) to polymeric methylene diphenyl diisocyanate (PMDI) were performed in rats. Investigations were made at the end of exposures and after 3, 10 and 30 days of recovery following single acute exposures and after 30 days of recovery following 28 days of exposure. Acute exposures to 10, 30 or 100 mg m,3 PMDI produced clinical signs in all animals that were consistent with exposure to irritant aerosols. An exposure concentration-related body weight loss and increase in lung weight were seen post-exposure, with complete recovery by day 8. The time course of changes in the lung over the initial days following exposure consisted of a pattern of initial toxicity, rapid and heavy influx of inflammatory cells and soluble markers of inflammation and cell damage, increased lung surfactant, a subsequent recovery and epithelial proliferative phase and, finally, a return to the normal status quo of the lung. During these stages there was evidence for perturbation of lung surfactant homeostasis, demonstrated by increased amounts of crystalline surfactant and increased number and size of lamellar bodies within type II alveolar cells. Repeated exposure over 28 days to the less toxic concentrations of 1, 4 or 10 mg m,3 PMDI produced no clinical signs or body weight changes, but an increase in lung weight was seen in animals exposed to 10 mg m,3, which resolved following the 30-day recovery period. Other effects seen were again consistent with exposure to irritant aerosols, but were less severe than those seen in the acute study. Analysis of bronchoalveolar lavage fluid revealed similar changes to those seen in the acute study. At both 10 and 4 mg m,3 PMDI increased numbers of ,foamy' macrophages in lung lavage cell pellet correlated with the increased phospholipid content of the pellet. Changes in lung lavage parameters and electron microscopic evidence again suggested perturbations in surfactant homeostasis. Histologically, bronchiolitis and thickening of the central acinar regions was seen at 10 and 4 mg m,3, reflecting changes in cell proliferation in the terminal bronchioles and centro-acinar regions. Almost all effects seen had recovered by day 30 post-exposure. Both acute and subacute studies demonstrate rapid recovery of effects in the lung following exposure to PMDI, with no progression of these effects even at concentrations higher than those shown to produce tumours in a chronic study. These findings add weight to the hypothesis that pulmonary tumours seen following chronic exposure to PMDI are most likely due to a combination of the chronic irritant effects of repeated exposure, coupled with the presence of insoluble polyureas formed by polymerization of PMDI (found in studies reported here and previous chronic studies), and therefore acute or short-term exposures to PMDI are likely to be of little concern for long-term pulmonary health. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Role of Inducible Nitric Oxide Synthase in Skeletal Adaptation to Acute Increases in Mechanical Loading,,

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 6 2002
Makoto Watanuki M.D.
Abstract To clarify the role of nitric oxide (NO) in regulation of bone metabolism in response to skeletal loading, we examined inducible NO synthase (iNOS) gene knockout mice in the tail-suspension model. Histomorphometric analyses of proximal tibias revealed that 7 days of tail suspension decreased the bone volume (BV/TV) and bone formation rate (BFR/BS) and increased the osteoclast surface (Oc.S/BS) in mice with all iNOS genotypes. Both iNOS+/+ and iNOS+/, mice responded to subsequent 14-day reloading, with increases in BV/TV and BFR/BS and a decrease in Oc.S/BS, whereas these responses were abolished in iNOS,/, mice. The osteoblasts flattened after tail suspension appeared cuboidal during subsequent reloading. Immunoreactivity for iNOS was detected in these osteoblasts and osteocytes by immunohistochemistry. These defective responses after reloading were rescued in iNOS,/, mice by treatment with an NO donor nitroglycerine (NG). Conversely, the responses in iNOS+/+ mice were inhibited by treatment with an NOS inhibitor aminoguanidine (AG). In bone marrow cell cultures, mineralized nodules derived from iNOS,/, mice after reloading were significantly reduced. Taken together, our results suggest that NO generated by iNOS in osteoblasts plays a critical role in adjusting bone turnover and increasing osteogenic activity in response to the acute increase in mechanical loading after tail suspension. [source]

On "Acute Effect of Cerivastatin on Cardiac Regional Ischemia in a Rat Model Mimicking Off-pump Coronary Surgery"

JOURNAL OF CARDIAC SURGERY, Issue 6 2005
Michael A. Borger M.D., Ph.D.
No abstract is available for this article. [source]

Circumferential Ultrasound Ablation for Pulmonary Vein Isolation: Analysis of Acute and Chronic Failures

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2002
WALID SALIBA M.D.
Circumferential Ultrasound Ablation for PV Isolation.Introduction: In patients undergoing circumferential isolation of the pulmonary veins with an ultrasound ablation system, we analyzed the temperatures achieved while delivering circumferential ostial lesions in the pulmonary veins. We also reviewed the angiograms obtained during the procedure and identified anatomic variants that could be responsible for ineffective lesion formation. Methods and Results: During the early clinical use in 33 patients, a total of 85 veins were ablated. A mean of 16.9 ± 12.3 ablations were delivered per patient, and a mean of 6.7 ablations per vein were applied. Entry block was assessed by placing a deflectable octapolar or a circular catheter in the vein. The following anatomic characteristics and technical limitations were identified as possible reasons for ineffective energy delivery: (1) funnel-shaped ostium; (2) ostial diameter larger than the balloon diameter; (3) inability to deliver the catheter to the right inferior or other vein ostia; (4) ostial instability; (5) early branching of the vein; and (6) eccentric position of the ultrasound transducer in the vein. In patients with recurrence of atrial fibrillation, 40% of the ostial lesions reached a temperature > 60°C. However, in patients cured by the ablation, 64% of the ostial lesions reached a temperature > 60°C (P < 0.06). At least 12 of the 20 chronic recurrences could have been related to technical limitations of the first system. Duration of atrial fibrillation and eccentric deployment of the ultrasound transducer were more frequent in patients with recurrence of arrhythmias at follow-up. Conclusion: Ostial anatomy of the veins may affect delivery of ultrasound energy to achieve circumferential lesions. Energy delivery at the ostium with a temperature > 60°C may be important to maximize success. Reconfiguration of the system to overcome the shortcomings identified in the initial experience could increase its performance. [source]

Effect of Electrical and Structural Remodeling on Spatiotemporal Organization in Acute and Persistent Atrial Fibrillation

JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2002
JOSEPH G. AKAR M.D.
Spatiotemporal Organization in Atrial Fibrillation.Introduction: Atrial fibrillation (AF) may originate from discrete sites of periodic activity. We studied the effect of structural and electrical remodeling on spatiotemporal organization in acute and persistent AF. Methods and Results: Atrial effective refractory periods (AERPs) were recorded from five different sites at baseline and after pacing in acute AF (n = 8 dogs) and persistent AF (n = 8). Four persistent AF dogs subsequently were cardioverted to sinus rhythm to allow AERP recovery. Periodicity was quantified by calculating power spectra on left atrial electrograms obtained from a 64-electrode basket catheter. Left atrial size was measured by intracardiac echocardiography and structural changes were assessed by electron microscopy. Mean AERPs decreased after pacing in acute (128 ± 16 msec to 108 ± 29 msec, P < 0.001) and persistent AF (135 ± 16 msec to 104 ± 24 msec, P < 0.0001). AERP recovery was established after 7 days of sinus rhythm. Structural changes were mild in acute AF, severe in persistent AF, and remained severe after AERP recovery. A single dominant frequency was identified in 94% of acute AF bipoles, 57% in persistent AF, and 76% after AERP recovery. Average correlation coefficient was 0.82 among acute AF bipoles, 0.63 in persistent AF, and 0.73 after AERP recovery. Conclusion: Transition from acute to persistent AF is associated with loss of spatiotemporal organization. A single dominant frequency recruits the majority of the left atrium in acute AF. Persistent AF, however, is associated with structural remodeling and dominant frequency dispersion. Recovery of refractoriness only partially restores spatiotemporal organization, indicating a major role for structural remodeling in the maintenance of persistent AF. [source]

Acute and Critical Care Clinical Nurse Specialists: Synergy for Best Practices

JOURNAL OF CLINICAL NURSING, Issue 14 2008
Janice Rattray
[source]

Teasing, rejection, and violence: Case studies of the school shootings

AGGRESSIVE BEHAVIOR, Issue 3 2003
Mark R. Leary
Abstract Media commentators have suggested that recent school shootings were precipitated by social rejection, but no empirical research has examined this claim. Case studies were conducted of 15 school shootings between 1995 and 2001 to examine the possible role of social rejection in school violence. Acute or chronic rejection,in the form of ostracism, bullying, and/or romantic rejection,was present in all but two of the incidents. In addition, the shooters tended to be characterized by one or more of three other risk factors,an interest in firearms or bombs, a fascination with death or Satanism, or psychological problems involving depression, impulse control, or sadistic tendencies. Implications for understanding and preventing school violence are discussed. Aggr. Behav. 29:202,214, 2003. © 2003 Wiley-Liss, Inc. [source]

Responses to handling and confinement stressors in juvenile great sturgeon Huso huso

JOURNAL OF FISH BIOLOGY, Issue 4 2009
B. Falahatkar
The effects of acute stressors on physiological responses of juvenile great sturgeon or beluga Huso huso L. were investigated in two experiments. In the first experiment, fish were handled by placing them in containers at either low density (LD, one fish l,1) or high density (HD, four fish l,1) for 60 s. Concentrations of plasma cortisol, glucose and lactate were determined from blood collected at 0, 1, 3, 6 and 12 h after application of the stressor. Plasma cortisol concentrations increased after the disturbance in H. huso from both handling treatments, but changes were not significant. Plasma glucose rose significantly by 22·9 and 31·6% in LD and HD handling treatments, respectively, after 3 h. Significant increases in plasma lactate occurred within 1 h in both treatment groups, but that of the HD group was much higher. In the second experiment, fish were held at two different densities, LD (2 kg m,2 tank bottom surface area) and HD (7 kg m,2), for 8 weeks and then subjected to an aerial emersion handling stressor in a net for 60 s; blood samples were taken before handling (resting, 0 h) and at 1, 3, 6 and 9 h after handling. Plasma cortisol increased significantly in fish from the HD treatment from 8·8 ± 0·3 to 19·2 ± 2·4 ng ml,1 (mean ±s.e.) by 1 h after stress, but post-handling changes in the LD group were not significant. Significant increases in both plasma glucose and lactate were observed by 1 h in both treatment groups, with peak levels of plasma glucose evident at 3 h [69·4 ± 2·9 and 60·9 ± 1·7 mg dl,1 (mean ±s.e.) in LD and HD groups, respectively]. Plasma glucose levels were significantly higher in the LD group than in the HD group at 3 and 6 h. Post-handling haemoglobin content increased by 1 h and white blood cell numbers were reduced by 3 and 6 h in the HD treatment group compared with resting values, but changes in these blood features in the LD group were not significant. Acute handling did not affect haematocrit in either treatment. The results suggest that H. huso is relatively resistant to handling and confinement, and could tolerate normal hatchery practices associated with aquaculture. Because changes in cortisol concentrations were relatively low compared with those in most teleosts, glucose and lactate concentrations may be more useful as stress indicators in juvenile H. huso. This study also demonstrated that prior exposure to a chronic stressor, specifically high stocking density, could alter the physiological response to subsequent acute handling in H. huso. [source]