Implementing a Discharge Opioid Bundle in Adult Trauma Patients Decreases the Amount of Opioids Prescribed at Discharge

BACKGROUND

Opioids remain the mainstay treatment of acute pain caused by trauma. The lack of evidence driven prescribing creates a challenging situation for providers. We hypothesized that the implementation of a trauma discharge opioid bundle (TDOB) would decrease the total morphine milligram equivalents (MME) prescribed at discharge while maintaining pain control.

METHODS

This was a pre-post study of adult trauma patients before and after implementation of a TDOB to guide the prescription of opioids and discharge prescription education in patients discharged from a level one trauma center. The pre-group and post-group, included consecutively discharged patients from September through November in 2018 and 2019. The primary outcome was the total MME prescribed at discharge.

RESULTS

A total of 377 patients met inclusion criteria. One hundred and fifty-one patients were included in the pre-group and 226 in the post-group. The total MME prescribed at discharge (225 ± [150-300] pre vs 200 ± [100-225] post, P = < .001) and maximum MME/day (45 ± [30-45] vs 30 ± [20-45], P = .004) were significantly less in the post-group. Incidence of outpatient refills within fourteen days were similar. More non-opioid pain adjuncts were prescribed post-intervention and discharge pain education was provided more frequently.

CONCLUSION

The implementation of a TDOB significantly reduced the MME prescribed at discharge without increasing the number of opioid refills.

Pediatric reference intervals for endocrine markers in healthy children and adolescents on the Liaison XL (DiaSorin) immunoassay system

OBJECTIVES

Prominent physiological changes occurring throughout childhood and adolescence necessitate the consideration of age and sex in biomarker interpretation. Critical gaps exist in pediatric reference intervals (RIs) for specialized endocrine markers, despite expected influence of growth and development. The current study aimed to establish and/or verify RIs for six specialized endocrine markers on a specialized immunoassay system.

METHODS

Samples were collected from healthy children and adolescents (5 to <19 years) and apparently healthy outpatients (0 to <5 years) as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER). Serum samples were analysed for aldosterone, renin (plasma), thyroglobulin, anti-thyroglobulin, growth hormone, and insulin-like growth factor-1 (IGF-1) on the Liaison XL (DiaSorin) immunoassay platform. RIs (2.5th and 97.5th percentiles) were established for aldosterone, renin, thyroglobulin, anti-thyroglobulin, and growth hormone. Manufacturer-recommended pediatric RIs for IGF-1 were verified.

RESULTS

Age-specific RIs were established for aldosterone, renin, and thyroglobulin, while no age-specific differences were observed for anti-thyroglobulin or growth hormone. IGF-1 was the only endocrine marker studied that demonstrated significant sex-specific differences. Manufacturer-recommended IGF-1 RIs were verified for children aged 6 to <19 years, while those for children aged 0 to <6 years did not verify.

CONCLUSIONS

This study marks the first time that pediatric RIs for aldosterone and renin were established in the CALIPER cohort and highlights the dynamic changes that occur in water and sodium homeostasis during the first years of life. Overall, these data will assist pediatric clinical laboratories in test result interpretation and improve clinical decision-making for patients tested using Liaison immunoassays.

Diabetic mitochondria are resistant to palmitoyl CoA inhibition of respiration, which is detrimental during ischemia

The bioactive lipid intermediate palmitoyl CoA (PCoA) can inhibit mitochondrial ADP/ATP transport, though the physiological relevance of this regulation remains unclear. We questioned whether myocardial ischemia provides a pathological setting in which PCoA regulation of ADP/ATP transport would be beneficial, and secondly, whether the chronically elevated lipid content within the diabetic heart could make mitochondria less sensitive to the effects of PCoA. PCoA acutely decreased ADP‐stimulated state 3 respiration and increased the apparent K_m for ADP twofold. The half maximal inhibitory concentration (IC₅₀) of PCoA in control mitochondria was 22 µM. This inhibitory effect of PCoA on respiration was blunted in diabetic mitochondria, with no significant difference in the K_m for ADP in the presence of PCoA, and an increase in the IC₅₀ to 32 µM PCoA. The competitive inhibition by PCoA was localised to the phosphorylation apparatus, particularly the ADP/ATP carrier (AAC). During ischemia, the AAC imports ATP into the mitochondria, where it is hydrolysed by reversal of the ATP synthase, regenerating the membrane potential. Addition of PCoA dose‐dependently prevented this wasteful ATP hydrolysis for membrane repolarisation during ischemia, however, this beneficial effect was blunted in diabetic mitochondria. Finally, using ³¹P‐magnetic resonance spectroscopy we demonstrated that diabetic hearts lose ATP more rapidly during ischemia, with a threefold higher ATP decay rate compared with control hearts. In conclusion, PCoA plays a role in protecting mitochondrial energetics during ischemia, by preventing wasteful ATP hydrolysis. However, this beneficial effect is blunted in diabetes, contributing to the impaired energy metabolism seen during myocardial ischemia in the diabetic heart.

Short-term legacy effects of feedlot manure application on soil mesofauna

Little research exists on short-term legacy effects of feedlot manure application on soil mesofauna. This long-term (since 1998) study was on an irrigated clay loam soil in southern Alberta cropped to barley (Hordeum vulgare L.). We sampled the soil 3-4 yr (2017-2018) into the legacy period following 17 annual manure applications (1998-2014). The selected treatments sampled were stockpiled feedlot manure containing straw bedding applied at 0, 13, 39, and 77 Mg ha^-1 (dry wt.). Intact soil cores were taken at three depth intervals (0-3, 3-6, and 6-9 cm) in the fall over 2 yr to determine the densities of Acari (mites) suborders and Collembola (springtails) families. Significant (P ≤ .05) application rate effects occurred on Oribatida and Astigmata after 3 yr (but not after 4 yr) into the legacy phase, whereas Prostigmata were unaffected. Densities of Astigmata after 3 yr were 3.2- to 4.1-fold greater at the 77 Mg ha^-1 rate compared with three lower rates. Significant application rate effects occurred on Entomobryidae, Isotomidae, and Onychiuridae after 4 yr (but not after 3 yr), with no treatment effects on Neelidae. Densities of mesofauna were generally greater at higher than at lower rates, except for Entomobryidae in 2018, where the reverse trend occurred. Significant application rate effects were attributed to lower soil bulk density and greater volumetric soil water content and soil organic carbon. Therefore, legacy effects of feedlot manure application generally persisted on soil mesofauna 3-4 yr into the legacy phase but depended on mesofauna type, year, and depth.

Influence of Organic Amendment and Compaction on Nutrient Dynamics in a Saturated Saline-Sodic Soil from the Riparian Zone

Cattle grazing in wet riparian pastures may influence nutrient dynamics due to nutrient deposition in feces and urine, soil compaction, and vegetation loss. We conducted a lab incubation study with a saline-sodic riparian soil to study nutrient (N, P, S, Fe, Mn, Cu, and Zn) dynamics in soil pore water using Plant Root Simulator (PRS) probes and release of nutrients into the overlying ponded water during flooding. The treatment factors were organic amendment (manure, roots, and unamended control), compaction (compacted, uncompacted), and burial time (3, 7, and 14 d). Amendment treatment had the greatest impact on nutrient dynamics, followed by burial time, whereas compaction had little impact. The findings generally supported our hypothesis that organic amendments should first increase nitrate loss, then increase Mn mobility, then Fe mobility and associated release of P, and finally increase sulfate loss. Declines in nitrate due to amendment addition were small because nitrate was at low levels in all treatments due to high denitrification potential instead of being released to soil pore water or overlying water. Addition of organic amendment strongly increased Mn and Fe concentrations in overlying water and of adsorbed Fe on PRS probes but only increased Mn on PRS probes on Day 3 due to subsequent displacement from ion exchange membranes. Transport of P to overlying water was increased by organic amendment addition but less so for manure than roots despite higher P on PRS probes. The findings showed that saline-sodic soils in riparian zones are generally a nutrient source for P and are a nutrient sink for N as measured using PRS probes after 3 to 7 d of flooding.

Irreversible electroporation of the lumbar vertebrae in a porcine model: is there clinical-pathologic evidence of neural toxicity?

PURPOSE

To evaluate the effects of irreversible electroporation (IRE) in the porcine spine.

MATERIALS AND METHODS

This study was approved by the institutional animal care and use committee. Twenty computed tomographically guided IRE ablations in either a transpedicular location or directly over the posterior cortex were performed in the lumbar vertebrae of 10 pigs by a single operator. T1- and T2-weighted magnetic resonance (MR) imaging was performed with and without contrast material 2 or 7 days after ablation. Mathematical modeling was performed to estimate the extent of ablation. Clinical, radiologic, pathologic, and simulation findings were analyzed. The Miller low-bias back transformation was used to construct 95% confidence intervals for the mean absolute percentage difference between the maximum length and width of the ablation zone on MR images and pathologic measurements by using square-root-transformed data.

RESULTS

Bipolar IRE electrode placement and ablation were successful in all cases. The mean distances from the IRE electrode to the posterior wall of the vertebral body or the exiting nerve root were 2.93 mm ± 0.77 (standard deviation) and 7.87 mm ± 1.99, respectively. None of the animals had neurologic deficits. Well-delineated areas of necrosis of bone, bone marrow, and skeletal muscle adjacent to the vertebral body were present. Histopathologic changes showed outcomes that matched with simulation-estimated ablation zones. The percentage absolute differences in the ablation measurements between MR imaging and histopathologic examination showed the following average errors: 24.2% for length and 28.8% for width measurements on T2-weighted images, and 26.1% for length and 33.3% for width measurements on T1-weighted contrast material-enhanced images.

CONCLUSION

IRE ablation in the porcine spine is feasible and safe and produces localized necrosis with minimal neural toxicity. Signal intensity changes on images acquired with standard MR imaging sequences demonstrate the ablation zone to be larger than that at histopathologic examination.

Transport of Residual Nitrogen and Carbon through Intact Soil Cores Amended with Stockpiled Feedlot Manure with Wood-Chip or Straw Bedding

The environmental impact of using wood chips instead of straw bedding with feedlot manure on transport and leaching potential from feedlot manure is unknown. Our main objective was to determine if transport of total N, total organic N, NO-N, and nonpurgeable organic C (NPOC) to subsurface soil was lower for soils amended with feedlot manure if combined with wood chips compared with straw. A secondary objective was to compare transport of N and NPOC with organic amendments versus inorganic fertilizer. Stockpiled feedlot manure (SM) with wood chip (SM-WD) or barley straw (SM-ST) bedding at 39 Mg (dry wt.) ha, and inorganic fertilizer (IN) at 100 kg N ha, was applied annually for 13 yr to a clay loam soil in a replicated field experiment in southern Alberta, Canada. Intact soil cores were taken in fall 2011 (0-30 cm depth) from the three treatments, and the residual N and NPOC were eluted from the soil cores. Total N, total organic N, and NPOC were determined on filtered (1.0 μm) effluent samples that are primarily dissolved fraction but may contain some small particulate N and C. Peak concentrations, flow-weighted mean concentrations, and mass loss of total N, total organic N, NO-N, and NPOC were significantly ( ≤ 0.05) lower by 35 to 86% for SM-WD compared with SM-ST. Mean recoveries were also significantly lower for SM-WD than SM-ST by 0.07 to 8% (absolute difference). The transport behavior was similar for SM-WD and IN treatment, but solute transport was greater for SM-ST than for IN. Application of stockpiled feedlot manure with wood chips instead of straw bedding may be a beneficial management practice to reduce transport and leaching potential of N fractions and NPOC.

A mathematical model of adult subventricular neurogenesis

Neurogenesis has been the subject of active research in recent years and many authors have explored the phenomenology of the process, its regulation and its purported purpose. Recent developments in bioluminescent imaging (BLI) allow direct in vivo imaging of neurogenesis, and in order to interpret the experimental results, mathematical models are necessary. This study proposes such a mathematical model that describes adult mammalian neurogenesis occurring in the subventricular zone and the subsequent migration of cells through the rostral migratory stream to the olfactory bulb (OB). This model assumes that a single chemoattractant is responsible for cell migration, secreted both by the OB and in an endocrine fashion by the cells involved in neurogenesis. The solutions to the system of partial differential equations are compared with the physiological rodent process, as previously documented in the literature and quantified through the use of BLI, and a parameter space is described, the corresponding solution to which matches that of the rodent model. A sensitivity analysis shows that this parameter space is stable to perturbation and furthermore that the system as a whole is sloppy. A large number of parameter sets are stochastically generated, and it is found that parameter spaces corresponding to physiologically plausible solutions generally obey constraints similar to the conditions reported in vivo. This further corroborates the model and its underlying assumptions based on the current understanding of the investigated phenomenon. Concomitantly, this leaves room for further quantitative predictions pertinent to the design of future proposed experiments.

Effects of Near-infrared Laser Irradiation of Biodegradable Microspheres Containing Hollow Gold Nanospheres and Paclitaxel Administered Intraarterially in a Rabbit Liver Tumor Model

PURPOSE

To evaluate the effects of near-infrared (NIR) laser irradiation of microspheres (MS) containing hollow gold nanospheres (HAuNS) and paclitaxel (PTX) administered intraarterially in an animal model.

MATERIALS AND METHODS

For the ex vivo experiments, VX2 tumor-bearing rabbits underwent administration of MS-HAuNS or MS via the hepatic artery (HA). The animals were killed, the liver tumors were subjected to NIR irradiation, and temperature changes were estimated with magnetic resonance (MR) imaging. For the in vivo study, VX2 tumor-bearing rabbits were randomly assigned to three groups: MS-HAuNS-PTX-plus-NIR, MS-HAuNS-PTX, and saline-plus-NIR. Laser irradiation was delivered at 1 hour and at 3 days after administration of saline or MS-HAuNS-PTX via the HA. Animals were euthanized, and tumors were analyzed for necrosis and apoptosis. Plasma samples were collected from the MS-HAuNS-PTX-plus-NIR animals for PTX analysis.

RESULTS

Ex vivo experiments showed intratumoral heating in animals that received MS-HAuNS but no temperature change in animals that received MS. Animals treated with MS-HAuNS-PTX-plus-NIR showed a transient increase in plasma PTX levels after each NIR irradiation and significantly greater tumor necrosis than animals that received MS-HAuNS-PTX or saline-plus-NIR (44.9% vs 13.8% or 23.7%; P < .0001). The mean apoptotic index in the MS-HAuNS-PTX-plus-NIR group (5.01 ± 1.66) was significantly higher than the mean apoptotic index in the MS-HAuNS-PTX (2.99 ± 0.97) or saline-plus-NIR (1.96 ± 0.40) groups (P = .0013).

CONCLUSIONS

NIR laser irradiation after MS-HAuNS-PTX administration results in intratumoral heating and increases the efficacy of treatment. Further studies are required to evaluate the optimal laser settings to maximize therapeutic efficacy.

Influence of streambank fencing on the environmental quality of cattle-excluded pastures

Limited information exists on the effect of streambank fencing on riparian zone pastures. The objective of this study was to test the hypothesis that 4 to 6 yr of streambank fencing would improve the environmental quality of the cattle-excluded pasture compared with the grazed pasture and cause the fenced pasture to act as a buffer or filter strip. Rangeland health, vegetative and soil properties, and rainfall simulation runoff were measured in the cattle-excluded and adjacent grazed native pastures along the fenced reach of the Lower Little Bow River in southern Alberta, Canada, for 3 yr (2005-2007). Rangeland health was improved (health score increase from 55 to 72%); vegetation cover (13-21%) and standing litter (38-742%) were increased; and bare soil (72-93%) and soil bulk density (6-8%) were decreased under cattle exclusion, indicating an improvement in environmental quality from streambank fencing. In contrast, other vegetation (total and live basal area, fallen litter) and soil properties (soil water and soil C, N, and P) were not improved by cattle exclusion. Cattle exclusion significantly (P </= 0.10) reduced surface runoff depth of water (21-32%) and mass loads of total N fractions (21-52%) in 2 of 3 yr compared with the grazed pasture, suggesting that this fenced pasture may act as a buffer for certain runoff variables. In contrast, other runoff variables (turbidity, electrical conductivity, pH, concentrations and loads of total suspended solids, and certain N and P fractions) in the cattle-excluded pasture were generally not improved by streambank fencing. Overall, streambank fencing improved the quality of certain environmental variables within the cattle-excluded pasture.

Computed tomographic emphysema distribution: relationship to clinical features in a cohort of smokers

Computed tomography (CT) scanning allows precise assessment of both the extent and distribution of emphysema. There has been little work on the relationship between the distribution of emphysema and clinical features of the disease. The current study investigated the association between clinical features and distribution of emphysema. A total of 129 patients with smoking-related chronic obstructive pulmonary disease underwent CT assessment of the extent and distribution of their emphysema (core/rind and upper/lower zone predominance). Emphysema was found predominantly in the upper/core zone and this distribution was related to the extent of disease. Core predominance was associated with lower forced expiratory volume in one second (FEV(1)), FEV(1)/forced vital capacity ratio and body mass index (BMI); and with higher BODE (BMI, airflow obstruction, dyspnoea and exercise capacity) index and Medical Research Council dyspnoea score. Upper-zone predominance was associated with female sex and an increased total St George's Respiratory Questionnaire score. Using multiple linear regression age, sex and whole lung emphysema severity were independently associated with core/rind distribution, while sex and whole lung emphysema severity were independently related to upper/lower distribution. Distribution of emphysema related best to clinical features when divided into core/rind predominance. However, the effects were not independent of the extent of emphysema. Increased age and female sex were related to disease distribution independent of emphysema severity. These findings may be related to differences in development of emphysema.

Aberration correction by maximizing generalized sharpness metrics

The technique of maximizing sharpness metrics has been used to estimate and compensate for aberrations with adaptive optics, to correct phase errors in synthetic-aperture radar, and to restore images. The largest class of sharpness metrics is the sum over a nonlinear point transformation of the image intensity. How the second derivative of the point nonlinearity varies with image intensity determines the effects of various metrics on the imagery. Some metrics emphasize making shadows darker, and other emphasize making bright points brighter. One can determine the image content needed to pick the best metric by computing the statistics of the image autocorrelation or of the Fourier magnitude, either of which is independent of the phase error. Computationally efficient, closed-form expressions for the gradient make possible efficient search algorithms to maximize sharpness.

Hydrological properties of a clay loam soil after long-term cattle manure application

Limited information exists on the effect of long-term application of beef cattle (Bos taurus) manure on soil hydrological properties in the Great Plains region of North America. A site on a clay loam soil (Typic Haploboroll) was used to examine the effect of manure addition on selected soil hydrological properties in 1997 and 1998. The manure was annually applied in the fall for 24 yr at one, two, and three times the recommended rates (in 1973) under dryland (0, 30, 60, and 90 Mg ha(-1) wet basis) and irrigation (0, 60, 120, and 180 Mg ha(-1)). Manure significantly (P < or = 0.05) increased soil water retention (0-5 and 10-15 cm) by 5 to 48% compared with the control at most potentials between 0 and -1500 kPa. Field soil water content (0-5 and 10-15 cm) was increased by 10 to 22% in the summers of 1997 and 1998. Manure increased ponded infiltration by more than 200% at 90 Mg ha(-1) under dryland (1998) and at rates > or = 120 Mg ha(-1) under irrigation (1997). Field-saturated hydraulic conductivity (Kfs) of surface soil (1-cm depth) was significantly increased by 76 to 128% under dryland (1998) and irrigation (1997), as were number of pores > 1120 microm in diameter (37-128% increase). In contrast, manure rate had little or no effect on unsaturated hydraulic conductivity [K(psi)] values (-0.3, -0.5, -0.7, and -1.0 kPa) in 1997 and 1998. Overall, soil hydrological parameters generally had a neutral or positive response to 24 yr of annual manure addition.

Preischemic hyperglycemia-aggravated damage: evidence that lactate utilization is beneficial and glucose-induced corticosterone release is detrimental

Aerobic lactate utilization is crucial for recovery of neuronal function posthypoxia in vitro. In vivo models of cerebral ischemia pose a conceptual challenge when compared to in vitro models. First, the glucose paradox of cerebral ischemia, namely, the aggravation of delayed neuronal damage by preischemic hyperglycemia, cannot be reproduced in vitro. Second, in vitro elevated glucose levels protect against ischemic (hypoxic) damage, an outcome that has seldom been reproduced in vivo. Employing a rat model of cardiac-arrest-induced transient global cerebral ischemia (TGI), we found that hyperglycemic conditions, when induced 120-240 min pre-TGI, significantly reduced post-TGI neuronal damage as compared to normoglycemic conditions. In contrast, hyperglycemia, when induced 15-60 min pre-TGI, significantly aggravated post-TGI neuronal damage. Brain lactate levels in rats loaded with glucose either 15 min or 120 min pre-TGI were significantly and equally higher than those of control, saline-injected rats. The beneficial effect of 120 min pre-TGI glucose loading was abolished by lactate transport inhibition. A significant increase in blood corticosterone (CT) levels was observed upon glucose loading that peaked at 15-30 min and returned to baseline levels by 60-120 min. When rats loaded with glucose 15 min pre-TGI were treated with metyrapone, a CT synthesis inhibitor, a significantly lower degree of delayed neuronal damage in comparison to both untreated, 15 min glucose-loaded rats and normoglycemic, control rats was observed. Thus, although elevated levels of brain lactate cannot explain the glucose paradox of cerebral ischemia, hyperglycemia-induced, short-lived elevation in CT blood levels could. More importantly, lactate appears to play a crucial role in improving postischemic outcome.

Intracranial surgery: to shave or not to shave?

OBJECTIVE

In an effort to improve patient confidentiality as well as cosmesis, the authors have stopped shaving for all intracranial procedures. The objective was to determine whether this lack of shaving increased the postoperative infection rate.

DESIGN

A retrospective study was performed comparing all intracranial surgical procedures performed in the last 2(1/2) years, when hair was not shaved, with the infection rate in patients who did have their hair shaved in the preceding 3(1/2) years.

SETTING

An academic tertiary care referral center.

PATIENTS

Every patient (children and adults) who underwent an intracranial procedure by the skull base surgery team was included. Similar patient demographics were used for the hair-shaved group.

INTERVENTION(S)

Intracranial procedures consisted of acoustic tumor removal, vestibular nerve sections, skull base surgery procedures, vascular decompressions, and craniotomies for benign and malignant tumors.

MAIN OUTCOME MEASURES

The most essential criterion was to determine whether postoperative wound infection developed in a patient. This was documented as either minor (stitch abscess or wound dehiscence), moderate (wound breakdown requiring inpatient or outpatient therapy, such as oral or intravenous antibiotics), or severe (significant wound breakdown that required hospitalization, with surgical debridement and antibiotics).

RESULTS

In all, 150 patients were not shaved for their intracranial procedures; postoperative wound infections developed in 11 (7%). The infections were minor (6), moderate (5), and severe (0). By comparison, 100 patients undergoing intracranial procedures had their hair shaved. In this group, the number of infections noted was 6 (6%). Their categorization into mild, moderate, and severe was 4, 2, and 0, respectively. Statistical analysis did not reveal any significant difference between the two infection rates.

CONCLUSIONS

The rate of postoperative wound infection was statistically no greater when the hair was shaved than when it was not. Thus, for patient confidentiality as well as patient esteem, we recommend not shaving hair for intracranial procedures.

Sleep disorders: a risk factor for normal-tension glaucoma?

PURPOSE

To determine the prevalence of sleep-related symptoms and sleep-related breathing disorders by polysomnography in patients with normal-tension glaucoma (NTG).

PATIENTS AND METHODS

This comparative case series included 23 patients with NTG, 14 NTG suspects, and 30 comparison patients without NTG. A sleep history was obtained and determined to be positive or negative. Polysomnography was offered for patients with a positive sleep history. Prevalence of a positive sleep history and prevalence of sleep disorders were the main outcome measures.

RESULTS

The NTG, NTG suspect, and comparison groups did not differ with respect to age, body mass index, systemic disease, gender, or race. Thirteen (57%) of 23 patients with NTG, 6 (43%) of 14 NTG suspects, and 1 (3%) of 30 comparison patients had a positive sleep history (P = 0.001). Nine of 13 patients with NTG and four of six NTG suspects with a positive sleep history chose to undergo polysomnography. Seven (78%) of nine patients with NTG and all four NTG suspects undergoing polysomnography were diagnosed with a sleep disorder. Five patients with NTG had sleep apnea and two had sleep hypopnea. Two NTG suspects had sleep apnea; one had sleep hypopnea; and one had upper airway resistance syndrome. The one comparison patient with a positive sleep history had upper airway resistance syndrome by polysomnography.

CONCLUSIONS

Sleep-disturbed breathing may be a risk factor for NTG. Although we do not provide evidence for a cause-and-effect relationship, various physiologic factors produced by sleep-disturbed breathing may play a significant role in the pathogenesis of this optic neuropathy. We recommend obtaining a sleep history from patients with NTG and performing polysomnography in those patients with sleep disturbance symptoms.

Sleep disorders: a risk factor for pseudotumor cerebri?

OBJECTIVE

To determine whether sleep-related breathing disorders are common in patients with idiopathic intracranial hypertension.

MATERIALS AND METHODS

Medical records of 53 patients with idiopathic intracranial hypertension from a tertiary center neuroophthalmology practice were reviewed. Thirty-seven patients were identified who had a history of snoring, difficulty sleeping, or daytime somnolence. The data from polysomnograms were tabulated to determine the frequency of apneas, hypopneas, and arousals.

RESULTS

Fourteen of 37 patients with idiopathic intracranial hypertension and symptoms of sleep disturbance underwent polysomnography. There were two men and 12 women varying in age from 24 to 58 years (mean, 39.4 +/- 11.9). These patients were obese with body mass indexes varying from 33.0 to 63.2 (mean, 46.0 +/- 9.5). A diagnosis of sleep apnea was made in six and upper airway resistance syndrome in seven patients.

CONCLUSIONS

Sleep-related breathing problems were common in our patients with idiopathic intracranial hypertension. Obesity was common in these patients and may be playing a causative role in sleep apnea and idiopathic intracranial hypertension. It is suggested that idiopathic intracranial hypertension patients who have symptoms of sleep disturbance should be further evaluated for the presence of sleep-related breathing problems.

Blockade of lactate transport exacerbates delayed neuronal damage in a rat model of cerebral ischemia

Studies over the past decade have demonstrated that lactate is produced aerobically during brain activation and it has been suggested to be an obligatory aerobic energy substrate postischemia. It has been also hypothesized, based on in vitro studies, that lactate, produced by glia in large amounts during activation and/or ischemia/hypoxia, is transported via specific glial and neuronal monocarboxylate transporters into neurons for aerobic utilization. To test the role of lactate as an aerobic energy substrate postischemia in vivo, we employed the cardiac-arrest-induced transient global cerebral ischemia (TGI) rat model and the monocarboxylate transporter inhibitor alpha-cyano-4-hydroxycinnamate (4-CIN). Once 4-CIN was establish to cross the blood--brain barrier, rats were treated with the inhibitor 60 min prior to a 5-min TGI. These rats exhibited a significantly greater degree of delayed neuronal damage in the hippocampus than control, untreated rats, as measured 7 days post-TGI. We concluded that intra-ischemically-accumulated lactate is utilized aerobically as the main energy substrate immediately postischemia. Blockade of lactate transport into neurons prevents its utilization and, consequently, exacerbates delayed ischemic neuronal damage.

The glucose paradox in cerebral ischemia. New insights

The present in vivo findings that lactate, accumulated during an ischemic episode, is an essential aerobic energy substrate during the initial postischemic period are in full agreement with out in vitro findings. Moreover, the beneficial effects of hyperglycemia are also in agreement with our and others' in vitro results that have demonstrated a neuroprotective effect of glucose against hypoxic change. The aggravation of ischemic delayed neuronal damage by glucose loading 15 min prior to the ischemic insult is likely the result of glucose induction of a short-acting (30 to 60 min) systemic factor (hormonal?) that, when combined with an ischemic insult, potentiates the ischemic damage.

In vitro, animal, and human characterization of OPTISON infusions for myocardial contrast echocardiography

Traditionally, performing myocardial contrast echocardiography with OPTISON required maximal bolus dosing. However, sustained and consistent opacification of the myocardium would be preferable for perfusion imaging.

METHODS

Images of 5 anesthetized dogs and 6 human volunteers were obtained with a second harmonic ultrasound system during bolus administration of OPTISON and 2 infusion techniques. One infusion technique used diluted OPTISON, and the other used the buoyant properties of OPTISON microspheres by placing the contrast agent between an infusion source and the intravenous site in a vertically oriented extension line (ELT). Myocardial intensities and in vitro microsphere characteristics were analyzed to assess the consistency of microsphere delivery over time.

RESULTS

In addition to providing higher myocardial opacification intensity than diluted infusions, ELT infusions provided consistent microsphere concentration, phantom enhancement, and near-peak bolus-level myocardial opacification for 7 to 15 minutes. The myocardial intensity at 3 and 5 minutes in human subjects during ELT infusions (30 mL/h; 2.5 mL) was lower (220 arbitrary units [au] and 165 au, respectively) but not significantly different (P =.3 and.1, respectively) than the peak myocardial intensity (265 au) after bolus administration.

CONCLUSION

This new ELT infusion method provides an acceptable alternative to bolus administration of OPTISON for prolonged myocardial opacification.

The Contributions of Wayne Ruppenthal to the Field of Music Therapy

This paper examines the career of Wayne Ruppenthal, considered one of the early pioneers in the field of music therapy. He began his practice in the late 1940s and his clinical accomplishments at Topeka State Hospital, spanned nearly two decades during the height of Freudian psychoanalysis and "milieu" therapy prescribed by The Menninger Foundation. Ruppenthal received his education at The University of Kansas in Lawrence, Kansas, and was the first graduate of the Master's of Music Education in Functional Music program in 1948. His contributions to the profession were significant and enduring and included establishing formal clinical practice and training standards, assisting with development of the National Association for Music Therapy (NAMT), and promoting the credibility of music therapy through published research. He retired from Topeka State Hospital in 1968. This paper is dedicated to the memory of Wayne Ruppenthal, who died on August 31, 1997.

Failure to demonstrate therapeutic tachyphylaxis to topically applied steroids in patients with psoriasis

BACKGROUND

Tachyphylaxis, defined as a rapidly decreasing response to a physiologically active agent after administration of a few doses, can be well demonstrated in the experimental setting. However, tachyphylaxis in the clinical setting lacks clear demonstration.

OBJECTIVE

Our purpose was to identify dermatologists' perception of the clinical incidence of tachyphylaxis and then design a prospective study that would estimate the clinical incidence of tachyphylaxis.

METHODS

Clinical and academic dermatologists completed a survey questionnaire about the incidence of tachyphylaxis and the time course to its occurrence. Subjects with plaque psoriasis applied topical corticosteroid twice daily for 12 weeks to their plaques, leaving an isolated plaque untreated for comparison. Plaques were evaluated every 2 weeks. By means of a 9-point scale, an end point for clinical detection of tachyphylaxis was defined as "an increase in plaque elevation of at least 2 occurring after a detectable decrease in plaque elevation with topical steroid."

RESULTS

The survey found that 57% of dermatologists perceived that tachyphylaxis occurred after 8 weeks of therapy with topical corticosteroid. In the 12-week clinical study, none of 32 patients exhibited detectable signs of tachyphylaxis.

CONCLUSION

What accounts for the commonly held belief of tachyphylaxis in the clinical setting may be related to the therapeutic efficacy of topical corticosteroids. Failure of topical corticosteroids to clear psoriasis after an initial improvement may give the impression of tachyphylaxis. The common clinical perception of tachyphylaxis may also be related to issues of compliance outside a study setting or a psoriasis flare unrelated to therapy.

Fosphenytoin reduces hippocampal neuronal damage in rat following transient global ischemia

Fosphenytoin, a water-soluble disodium phosphate ester of phenytoin, is a phenytoin prodrug with similar anticonvulsant properties. In this study, we evaluated its neuroprotective properties in a cardiac arrest-induced global ischemia model. After 12 minute ischemia, Long-Evans hooded rats were resuscitated, given fosphenytoin (30 mg/kg, i.m.) or saline 5 minutes after the ischemic episode, and killed on day 7. Brains were removed, fixed, and vibratome sectioned to assess the numbers of normal appearing CAI pyramidal neurons and for immunohistological staining of glial fibrillary acidic protein (GFAP). After global ischemia, the number of hippocampal CA1 pyramidal neurons decreased significantly (from 14.33 +/- 1.73 to 2.19 +/- 0.16 per 100 micron 2). Most hippocampal CA1 pyramidal neurons showed signs of injury and GFAP immunoreactivity of the region increased. With fosphenytoin treatment 5 min after ischemia, hippocampal CA1 pyramidal neurons remained at near control level (13.90 +/- 0.92), however, GFAP staining was not significantly changed. Our data, although indicating different neuronal and glial responses following fosphenytoin treatment, nevertheless, suggest that fosphenytoin is an effective neuroprotectant against ischemia-induced damage.

Study of cerebral energy metabolism using the rat hippocampal slice preparation

This article describes methods and experimental paradigms used in combination with the rat hippocampal slice preparation in an attempt to better understand cerebral energy metabolism under the following conditions: normal resting conditions, conditions of oxygen and/or glucose deprivation, and conditions of activation (excitation). The outcome of this attempt, as described herewith, demonstrates the unmatched usefulness of the brain slice preparation as an in vitro tool in the field of neuroscience.

Accentuated viral exanthems in areas of inflammation

Types of lesions and patterns of distribution aid in the recognition of viral exanthems. Varicella and hand-foot-and-mouth disease can appear atypically in areas of inflammation. We describe 5 cases of morphologically altered exanthems that localized early and preferentially to areas of inflammation.

An increase in lactate output by brain tissue serves to meet the energy needs of glutamate-activated neurons

Aerobic energy metabolism uses glucose and oxygen to produce all the energy needs of the brain. Several studies published over the last 13 years challenged the assumption that the activated brain increases its oxidative glucose metabolism to meet the increased energy demands. Neuronal function in rat hippocampal slices supplied with 4 mM glucose could tolerate a 15 min activation by a 5 mM concentration of the excitatory neurotransmitter glutamate (Glu), whereas slices supplied with 10 mM glucose could tolerate a 15 min activation by 20 mM Glu. However, in slices in which neuronal lactate use was inhibited by the lactate transporter inhibitor a-cyano-4-hydroxycinnamate (4-CIN), activation by Glu elicited a permanent loss of neuronal function, with a twofold to threefold increase in tissue lactate content. Inhibition of glycolysis with the glucose analog 2-deoxy-D-glucose (2DG) during the period of exposure to Glu diminished normal neuronal function in the majority of slices and significantly reduced the number of slices that exhibited neuronal function after activation. However, when lactate was added with 2DG, the majority of the slices were neuronally functional after activation by Glu. NMDA, a nontransportable Glu analog by the glial glutamate transporter, could not induce a significant increase in slice lactate level when administered in the presence of 4-CIN. It is suggested that the heightened energy demands of activated neurons are met through increased glial glycolytic flux. The lactate thus formed is a crucial aerobic energy substrate that enables neurons to endure activation.

Granulocyte-macrophage colony-stimulating factor induces activation and restores respiratory burst activity in monocytes from septic patients

Monocyte activation in response to recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) was examined in vitro in septic shock patients. These monocytes exhibited a greater respiratory burst activity than monocytes from healthy subjects; the response to secondary stimulation with bacterial stimuli was attenuated. GM-CSF restored the ability of monocytes to respond appropriately to secondary stimulation. Expression of certain integrin adhesion molecules, L-selectin, and Fcgamma receptors was increased on monocytes of septic shock patients; expression of CD11c was reduced. GM-CSF up-regulated integrin expression and decreased L-selectin, FcgammaRII, and FcgammaRIII expression. Septic patients exhibited greater biologic activity of monocyte tissue factor than did healthy subjects. Priming monocytes with GM-CSF accelerated tissue factor activation following stimulation with lipopolysaccharide and bacterial culture supernatant. Certain parameters of monocyte function may be restored by exposure to GM-CSF. This benefit may be offset by an increase in monocyte procoagulant activity.

Glia are the main source of lactate utilized by neurons for recovery of function posthypoxia

Experiments are described in which a rat hippocampal slice preparation was used along with the metabolic glial inhibitor, fluorocitrate (FC), to investigate the role of glial-made lactate and its shuttling to neurons in posthypoxia recovery of synaptic function. After testing two less effective concentrations of FC, only 10.1 +/- 6.5% of slices treated with 100 microM of the metabolic toxin recovered synaptic function at the end of 10-min hypoxia and 30-min reoxygenation. In contrast, 79.6 +/- 7.4% of control, untreated slices recovered synaptic function after 10-min hypoxia and 30-min reoxygenation. The low rate of recovery of synaptic function posthypoxia in FC-treated slices occurred despite the abundance of glucose present in the medium before, during, and after hypoxia. The amount of lactate produced by FC-treated slices during the hypoxic period was only 62% of that produced by control, untreated slices. Supplementing FC-treated slices with exogenous lactate significantly increased the posthypoxia recovery rate of synaptic function. These results strongly support our previous findings concerning the mandatory role of lactate as an aerobic energy substrate for the recovery of synaptic function posthypoxia and clearly show that the bulk of the lactate needed for this recovery originates in glial cells.

Sarcoid myopathy: imaging findings

Sarcoidosis is a granulomatous multisystem disorder that may uncommonly involve muscle. Muscular sarcoid may be nodular, atrophic myopathic, or acute myositic. We illustrate a case of the myopathic type of muscular sarcoid that is unusual because the abdominal wall muscles, rather than the extremity muscles, were involved. Muscular involvement by sarcoid should be considered in the differential diagnosis of focal muscle disease, especially in a patient with a known history of sarcoid. The presence of typical bilateral hilar adenopathy on a chest radiograph as well as the presence of abdominal findings (hepatosplenomegaly and retroperitoneal adenopathy) may help establish the diagnosis. Otherwise, sonographically guided biopsy may be necessary for definitive diagnosis.

Strategies for getting students on the information superhighway

Many nurses indicate that they lack the formal education needed to use resources such as the Internet and computer technology related to healthcare. The results of a survey at a baccalaureate school of nursing revealed that although nearly 100% of those surveyed used computers, very few effectively used available Internet resources. In response, the authors implemented strategies to make available Internet resources "user-friendly" for communication and information gathering.

Brain lactate is an obligatory aerobic energy substrate for functional recovery after hypoxia: further in vitro validation

This study used the rat hippocampal slice preparation and the monocarboxylate transporter inhibitor, alpha-cyano-4-hydroxycinnamate (4-CIN), to assess the obligatory role that lactate plays in fueling the recovery of synaptic function after hypoxia upon reoxygenation. At a concentration of 500 microM, 4-CIN blocked lactate-supported synaptic function in hippocampal slices under normoxic conditions in 15 min. The inhibitor had no effect on glucose-supported synaptic function. Of control hippocampal slices exposed to 10-min hypoxia, 77.8 +/- 6.8% recovered synaptic function after 30-min reoxygenation. Of slices supplemented with 500 microM 4-CIN, only 15 +/- 10.9% recovered synaptic function despite the large amount of lactate formed during the hypoxic period and the abundance of glucose present before, during, and after hypoxia. These results indicate that 4-CIN, when present during hypoxia and reoxygenation, blocks lactate transport from astrocytes, where the bulk of anaerobic lactate is formed, to neurons, where lactate is being utilized aerobically to support recovery of function after hypoxia. These results unequivocally validate that brain lactate is an obligatory aerobic energy substrate for posthypoxia recovery of function.

Hepatosplenic cat-scratch disease and abdominal pain

BACKGROUND

There have been several recent reports that cat-scratch disease (CSD) causes a multiplicity of atypical clinical syndromes. We recently diagnosed hepatosplenic CSD in a child who was seen with fever and abdominal pain. We report this case and 10 other patients with hepatosplenic CSD and highlight the importance of abdominal pain in this clinical entity.

METHODS

This was a retrospective review of charts of patients with a diagnosis of cat-scratch disease at Egleston Children's Hospital between January, 1985, and June, 1996. From these cases patients with hepatosplenic CSD were selected for study.

RESULTS

Seven children (64%) had significant abdominal pain, and in three children abdominal pain was their chief complaint. All children in the study had pathologic evidence of CSD or elevated titers of antibodies to Bartonella henselae. Ultrasound examination showed that all children had microabscesses in the spleen, and eight had abscesses in the liver.

CONCLUSIONS

One of the most remarkable findings in this large series of cases of hepatosplenic CSD was that 64% of the patients complained of abdominal pain. All children in this study received antibiotics. It was our clinical impression that once antibiotics had been started, the patients appeared to improve very quickly. With an increased index of suspicion, the use of B. henselae serology and an abdominal ultrasound examination, the diagnosis of this underrecognized disease might be more readily made.

Brain lactate, not glucose, fuels the recovery of synaptic function from hypoxia upon reoxygenation: an in vitro study

Lactate has been considered for many years to be a useless, and frequently, harmful end-product of anaerobic glycolysis. In the present in vitro study, lactate-supplied rat hippocampal slices showed a significantly higher degree of recovery of synaptic function after a short hypoxic period than slices supplied with an equicaloric amount of glucose. More importantly, all slices in which anaerobic lactate production was enhanced by pre-hypoxia glucose overload exhibited functional recovery after a prolonged hypoxia. An 80% recovery of synaptic function was observed even when glucose utilization was blocked with 2-deoxy-D-glucose during the later part of the hypoxic period and during reoxygenation. In contrast, slices in which anaerobic lactate production was blocked during the initial stages of hypoxia did not recover their synaptic function upon reoxygenation despite the abundance of glucose and the removal of 2-deoxy-D-glucose. Thus, for brain tissue to show functional recovery after prolonged period of hypoxia, the aerobic utilization of lactate as an energy substrate is mandatory.

Total clinical laboratory test volume in Connecticut, 1994-1995

OBJECTIVE

To measure the volume of clinical laboratory testing in Connecticut during a one-year period. To explore the potential value of such data.

DESIGN

Summary and analysis of federal and state clinical laboratory registration/licensure/inspection forms.

SETTING

2,333 clinical laboratory test facilities registered in Connecticut.

MAIN OUTCOME MEASURES

The total clinical laboratory output for Connecticut by type of facility and category of technology over a 12-month period.

RESULTS

During 1995, 2,333 registered clinical laboratory test facilities performed approximately 65,427,103 analyses in Connecticut. This represents approximately 20 tests per person per year. Thirty-five acute care hospitals performed 59.4%, nine large commercial laboratories 33.2%, 30 small commercial laboratories 1.7%, 1,491 physicians' offices 3.9%, and a miscellaneous group 1% of the tests. Test volumes are further segregated into eight major categories of technology: chemistry 59%, hematology 23.3%, microbiology 5.6%, blood banking 2.9%, coagulation 2.8%, waived tests 2.7%, urine analysis 1.8%, cytology 0.9%, and histology 0.8%.

CONCLUSION

For the first time mechanisms are in place to measure essentially all clinical testing for a given area. With minor changes the data collection system could be greatly improved. The possible uses for such a data bank are discussed.