US-guided core breast biopsy: use and cost-effectiveness

OBJECTIVES: We sought to determine, using serial echocardiography, the hydrodynamic mechanisms involved in the occurrence of hemolysis after mitral valve repair. BACKGROUND: Recently, fluid dynamic simulation models have identified distinct patterns of mitral regurgitant flow disturbances in patients with mitral prosthetic hemolysis that were associated with high shear stress and may therefore produce clinical hemolysis. Rapid acceleration, fragmentation, and collision jets were associated with high shear stress and hemolysis whereas slow deceleration and free jets were not. METHODS: We reviewed serial echocardiographic studies of 13 consecutive patients with hemolytic anemia after mitral valve repair who were referred for mitral reoperation between January 1985 and December 1996 (group 1). Thirteen patients undergoing reoperation for mitral regurgitation after mitral valve repair but without hemolysis served as controls (group 2). RESULTS: The mitral regurgitant jet was central in origin in 12 group 1 patients and 9 group 2 patients (Fisher exact test, p= 0.3). The other patients had para-ring regurgitation. Group 1 patients had collision (n=11), rapid acceleration (n=2) or fragmentation (n=1) jets whereas group 2 patients had slow deceleration (n=11) or free jets (n=2) (Fisher exact test, p < 0.0001). One patient with hemolysis had both collision and rapid acceleration jets. The "culprit" jet could be identified on the postbypass transesophageal echocardiography (TEE) study in only 1 patient at the time of initial mitral repair. Twelve group 1 patients underwent reoperation, with subsequent resolution of hemolysis in all patients. At reoperation, the initial repair was found to be intact in 8 (67%) patients. CONCLUSION: Distinct patterns of flow disturbance associated with high shear stress were identified by color Doppler imaging in patients with hemolysis after mitral valve repair. The majority (92%) of these color flow disturbances were not present during intraoperative postbypass TEE study after initial mitral repair and subsequently developed in the early postoperative period.     

Pediatric pain management in an adult critical care unit

Many children every year will be treated in "adult" critical care units because of the limited pediatric trauma centers currently available. Assessment is an integral part of all pain management. Ideally, self-report is the gold standard for assessing pain; however, some children may not have the ability to use these tools. Nonverbal children may be assessed with behavioral tools such as the CHEOPS or FLACC. In children as young as 3 years old, the self-report tool called an OUCHER can be administered to assess their pain. Easy to apply nonpharmacological approaches are discussed with recommendations for nurses to incorporate into their daily care.     

Cytochemical localization of acetylcholine receptors at the neuromuscular junction by means of horseradish peroxidase-labeled alpha-bungarotoxin

The cytochemical localization of acetylcholine (ACh) receptors at the neuromuscular junction was investigated with a procedure utilizing alpha-bungarotoxin (alpha-BtX) labeled directly with horseradish peroxidase (HRP). Following incubation of tissues in the conjugate and reaction for peroxidase, activity was observed on the junctional folds of the motor endplate. A uniform layer of reaction product approximately 15 nm thick occurred over the apical portions of the junctional folds. Membranes at the bases of the synaptic cleft showed only small amounts of reaction product. Non-junctional regions of the muscle fiber were unreactive. Activity was also observed in the membrane of the axon facing the muscle surface, often including the axolemma overlying the "active zones" of the nerve terminal. Such presynaptic activity was still evident on nerve terminals disjuncted from the synapse by enzymatic treatment prior to incubation in the conjugate. This localization indicates the possible presence of presynaptic ACh receptors within the axolemma. In muscle denervated for 7-12 days, motor endplates were reactive and parajunctional sarcolemma showed slight activity, but most extrajunctional regions contained no obvious accumulations of reaction product. Activity at all sites was prevented by preincubation of tissues in native alpha-BTX prior to incubation in the conjugate and reaction for HRP. This procedure represents a simple and convenient method for the high resolution localization of ACh receptors.     

Crash and burn? Vehicle,collision, and driver factors that influence motor vehicle collision fires

A retrospective population-based case–control study was performed to determine the association between vehicle fires, and vehicle, collision, and driver factors on highways with a posted speed limit of at least 55 mph. Data were obtained from the Kentucky Collision Report Analysis for Safer Highways (CRASH) electronic files for 2000–2009 from the Kentucky State Police Records Sections. The results from the final multiple logistic regression show that large trucks were at a higher risk for a collision involving a fire than passenger vehicles and pickup trucks. When controlling for all other variables in the model, vehicles 6 years old and older, driving straight down the highway, and single vehicle collisions were also identified as factors that increase the risk of motor vehicle collision fires on roadways with a posted speed limit of ≥55 mph. Of the 2096 vehicles that caught fire, there were 632 (30%) non-fatally injured drivers and 224 (11%) fatally injured drivers. The results of this study have the potential to inform public health messages directed to the transportation industry, particularly semi truck drivers, in regard to fire risk.     

CARBON FROM PERIPHYTON SUPPORTS FISH BIOMASS IN WATERHOLES OF A WET–DRY TROPICAL RIVER

The identification of the dominant sources of carbon supporting consumer biomass in aquatic food webs is often difficult but essential to understanding the limits to aquatic secondary production. Stable isotope analysis (SIA) is a powerful tool to estimate the contribution of different sources to consumers, but most food web studies using this approach limit analyses to a few key consumer taxa rather than measuring biomass‐weighted contribution of sources to the entire community. Here we combined stable isotope analysis with standardized measurements of abundance and biomass of fishes and invertebrates in seven waterholes of a wet–dry tropical river sampled early and late in the dry season. We showed that periphyton (as opposed to phytoplankton and terrestrial C3 plant detritus) was responsible for most standing fish biomass (range 42%–97%), whereas benthic invertebrates were reliant on a mixture of the three sources (range 26%–100%). Furthermore, larger, older fishes at high trophic levels (catfish Neoarius spp., sleepy cod Oxyeleotris lineaolatus and barramundi Lates calcarifer) were supported almost exclusively by periphyton. Phytoplankton and detritus supported a considerable biomass of benthic and pelagic invertebrates, but only in taxa that occupied low trophic levels (e.g. snails). These measurements provide further evidence that although periphyton is relatively inconspicuous relative to other sources, it contributes disproportionately to metazoan biomass in wet–dry tropical rivers. Copyright © 2012 John Wiley & Sons, Ltd.     

Spinal amino acid release and precipitated withdrawal in rats chronically infused with spinal morphine

Glutamate receptors are implicated in the genesis of opioid tolerance and dependence. Factors governing release of amino acids in systems chronically exposed to opiates, however, remain undefined. Using rats, each prepared with a spinal loop dialysis catheter and with a chronic lumbar intrathecal infusion catheter connected to a subcutaneous minipump, the release of amino acids before and during antagonist-precipitated withdrawal in unanesthetized rats was examined. Spinal infusion of morphine (20 nmol/micro l/hr) for 4 d had little effect on resting release of amino acids. In morphine-infused, but not saline-infused, rats naloxone (2 mg/kg, i.p.) evoked an immediate increase in the release of L-glutamate (299 +/- 143%) and taurine (306 +/- 113%) but not other amino acids. The magnitude and time course of the release of these amino acids significantly correlated with behavioral indices of withdrawal intensity. Acute intrathecal pretreatment immediately before naloxone with clonidine (20 microg; alpha2 agonist), MK-801 (3 microg; noncompetitive NMDA antagonist), or aminophosphonopentanoic acid (AP-5; 3 microg; competitive NMDA antagonist) suppressed naloxone-induced increases in spinal L-glutamate and taurine release and behavioral signs of withdrawal in spinal morphine-infused rats. Results point to a correlated increase in spinal L-glutamate release, which contributes to genesis of the opioid withdrawal syndrome. Agents such as clonidine that suppress opioid withdrawal may owe their action to an inhibition of excitatory amino acid release. The effects of MK-801 and AP-5 suggest a glutamate-evoked glutamate release.     

The effect of transdermal nicotine on digital perfusion in reformed habitual smokers

The effects of transdermal nicotine-assisted smoking cessation on digital perfusion and health-related quality of life were assessed in 10 chronic smokers. Components of digital blood flow were evaluated by digital temperature and laser Doppler fluxmetry before, during, and after a standardized cold challenge. Nutritional flow was measured by vital capillaroscopy; a quantitative perfusion profile was obtained by laser Doppler perfusion imaging. A battery of validated measures were used to evaluate health-related quality of life. The microvascular response of smokers was evaluated before smoking cessation and at 2 and 7 days after smoking cessation and was compared with the response of nonsmoking controls. Results demonstrated that a (1) cutaneous microvascular perfusion was lower in smokers than nonsmokers, (2) the acute administration of transdermal nicotine did not decrease cutaneous perfusion, (3) smoking cessation and transdermal nicotine normalized digital microvascular perfusion by 7 days, and (4) transdermal nicotine and smoking cessation did not negatively impact health-related quality of life.     

Fate of Escherichia coli O157:H7 in ground apples used in cider production

Survival of Escherichia coli O157:H7 in ground Golden Delicious, Red Delicious, Rome, and Winesap apples stored at 4, 10, and 25 degrees C was determined. E. coli O157:H7 populations were monitored for up to 18 days (4 degrees C), 12 days (10 degrees C), and 5 days (25 degrees C), when mold contamination became visible. At 25 degrees C, Red Delicious apples supported survival of E. coli O157:H7 better (P < 0.05) than the other cultivars, followed by Golden Delicious and Rome apples, which were not statistically different (P > 0.05). Winesap apples were the least favorable (P < 0.05) for survival of E. coli O157:H7 at 25 degrees C. E. coli O157:H7 was recovered at similar rates from Golden Delicious and Red Delicious apples, (P > 0.05), but pathogen populations increased in both cultivars (P < 0.05) during storage at 25 degrees C. At 10 degrees C, survival of E. coli O157:H7 was poorest (P < 0.05) in ground Red Delicious apples, while there was no significant difference in survival of E. coli O157:H7 among ground Golden Delicious, Rome, or Winesap cultivars (P > 0.05). When stored at 4 degrees C, Golden Delicious and Rome apples were not statistically different in supporting survival of the pathogen (P > 0.05). In general, apple pH increased during storage and was associated with mold growth. Results of this investigation indicate that there is no trend toward a particular apple cultivar supporting survival of E. coli O157:H7. However, variation in apple pH during storage can negatively or positively influence E. coli O157:H7 survival at 25 degrees C.