Appropriate use criteria for echocardiography in the Netherlands

Introduction

Appropriate use criteria (AUC) for echocardiography based on clinical scenarios were previously published by an American Task Force. We determined whether members of the Dutch Working Group on Echocardiography (WGE) would rate these scenarios in a similar way.

Methods

All 32 members of the WGE were invited to judge clinical scenarios independently using a blanked version of the previously published American version of AUC for echocardiography. During a face-to-face meeting, consensus about the final rating was reached by open discussion for each indication. For reasons of simplicity, the scores were reduced from a 9-point scale to a 3-point scale (indicating an appropriate, uncertain or inappropriate echo indication, respectively).

Results

Nine cardiologist members of the WGE reported their judgment on the echo cases (n = 153). Seventy-one indications were rated as appropriate, 35 were rated as uncertain, and 47 were rated as inappropriate. In 5% of the cases the rating was opposite to that in the original (appropriate compared with inappropriate and vice versa), whereas in 20% judgements differed by 1 level of appropriateness. After the consensus meeting, the appropriateness of 7 (5%) cases was judged differently compared with the original paper.

Conclusions

Echocardiography was rated appropriate when it is applied for an initial diagnosis, a change in clinical status or a change in patient management. However, in about 5% of the listed clinical scenarios, members of the Dutch WGE rated the AUC for echocardiography differently as compared with their American counterparts. Further research is warranted to analyse this decreased external validity.

Electronic supplementary material

The online version of this article (doi: 10.1007/s12471-017-0960-9) contains supplementary material, which is available to authorized users.

Seizures after single-agent overdose with pharmaceutical drugs: analysis of cases reported to a poison center

CONTEXT

Seizures during intoxications with pharmaceuticals are a well-known complication. However, only a few studies report on drugs commonly involved and calculate the seizure potential of these drugs.

OBJECTIVES

To identify the pharmaceutical drugs most commonly associated with seizures after single-agent overdose, the seizure potential of these pharmaceuticals, the age-distribution of the cases with seizures and the ingested doses.

METHODS

A retrospective review of acute single-agent exposures to pharmaceuticals reported to the Swiss Toxicological Information Centre (STIC) between January 1997 and December 2010 was conducted. Exposures which resulted in at least one seizure were identified. The seizure potential of a pharmaceutical was calculated by dividing the number of cases with seizures by the number of all cases recorded with that pharmaceutical. Data were analyzed using descriptive statistics.

RESULTS

We identified 15,441 single-agent exposures. Seizures occurred in 313 cases. The most prevalent pharmaceuticals were mefenamic acid (51 of the 313 cases), citalopram (34), trimipramine (27), venlafaxine (23), tramadol (15), diphenhydramine (14), amitriptyline (12), carbamazepine (11), maprotiline (10), and quetiapine (10). Antidepressants were involved in 136 cases. Drugs with a high seizure potential were bupropion (31.6%, seizures in 6 of 19 cases, 95% CI: 15.4-50.0%), maprotiline (17.5%, 10/57, 95% CI: 9.8-29.4%), venlafaxine (13.7%, 23/168, 95% CI: 9.3-19.7%), citalopram (13.1%, 34/259, 95% CI: 9.5-17.8%), and mefenamic acid (10.9%, 51/470, 95% CI: 8.4-14.0%). In adolescents (15-19y/o) 23.9% (95% CI: 17.6-31.7%) of the cases involving mefenamic acid resulted in seizures, but only 5.7% (95% CI: 3.3-9.7%) in adults (≥ 20y/o; p < 0.001). For citalopram these numbers were 22.0% (95% CI: 12.8-35.2%) and 10.9% (95% CI: 7.1-16.4%), respectively (p = 0.058). The probability of seizures with mefenamic acid, citalopram, trimipramine, and venlafaxine increased as the ingested dose increased.

CONCLUSIONS

Antidepressants were frequently associated with seizures in overdose, but other pharmaceuticals, as mefenamic acid, were also associated with seizures in a considerable number of cases. Bupropion was the pharmaceutical with the highest seizure potential even if overdose with bupropion was uncommon in our sample. Adolescents might be more susceptible to seizures after mefenamic acid overdose than adults. "Part of this work is already published as a conference abstract for the XXXIV International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 27-30 May 2014, Brussels, Belgium." Abstract 8, Clin Toxicol 2014;52(4):298.

Sheep persistently infected with Border disease readily transmit virus to calves seronegative to BVD virus

Bovine viral diarrhea- and Border disease viruses of sheep belong to the highly diverse genus pestivirus of the Flaviviridae. Ruminant pestiviruses may infect a wide range of domestic and wild cloven-hooved mammals (artiodactyla). Due to its economic importance, programs to eradicate bovine viral diarrhea are a high priority in the cattle industry. By contrast, Border disease is not a target of eradication, although the Border disease virus is known to be capable of also infecting cattle. In this work, we compared single dose experimental inoculation of calves with Border disease virus with co-mingling of calves with sheep persistently infected with this virus. As indicated by seroconversion, infection was achieved only in one out of seven calves with a dose of Border disease virus that was previously shown to be successful in calves inoculated with BVD virus. By contrast, all calves kept together with persistently infected sheep readily became infected with Border disease virus. The ease of viral transmission from sheep to cattle and the antigenic similarity of bovine and ovine pestiviruses may become a problem for demonstrating freedom of BVD by serology in the cattle population.

Numerical simulation and biomechanical analysis of an orthodontically treated periodontally damaged dentition

BACKGROUND AND OBJECTIVE

Once periodontitis has been completely resolved, one common follow-up method is to carry out orthodontic treatment to take advantage of the residual bone, i.e., via tooth intrusion. In this study, the biomechanical behavior of teeth in a reduced periodontium was studied by numerically simulating upper-incisor intrusion accomplished with various orthodontic mechanics.

MATERIALS AND METHODS

Using the finite element method, a patient-customized 3D model of a periodontally reduced dentition was generated in order to simulate tooth movement. The morphology of this upper-jaw model was derived from cone-beam computed tomography (CBCT) datasets of four patients. Material parameters were adopted from previous investigations, including teeth (E=20 GPa), periodontal ligament (PDL) (bilinear elastic; E1=0.05 MPa; E2=0.20 MPa; ε12=7%), and bone (homogeneous, isotropic; E=2 GPa). Two intrusion scenarios were used, the first drawing from Burstone's segmented-arch technique to intrude four splinted incisors at a time, and the second one using cantilevers to intrude single incisors. The aforementioned PDL material parameters were varied in several ways to simulate different biological and biomechanical states of PDL. All simulations were recalculated with an idealized, periodontally intact model to assess the effect of bone loss by way of comparison.

RESULTS

Single-tooth intrusion via cantilever mechanics was accompanied by less rotation than the segmented-arch approach. Both intrusion systems involved significantly greater degrees of tooth displacement and PDL load in the periodontally reduced model.

CONCLUSION

Periodontally reduced dentitions are associated with an increased load on periodontal tissue. This can be counteracted by reducing orthodontic force levels and by selecting mechanics that do not harm the tissue. In so doing, the use of numerical methods may greatly facilitate individualized computer-aided treatment-planning strategies.

Single trial discrimination of individual finger movements on one hand: a combined MEG and EEG study

It is crucial to understand what brain signals can be decoded from single trials with different recording techniques for the development of Brain-Machine Interfaces. A specific challenge for non-invasive recording methods are activations confined to small spatial areas on the cortex such as the finger representation of one hand. Here we study the information content of single trial brain activity in non-invasive MEG and EEG recordings elicited by finger movements of one hand. We investigate the feasibility of decoding which of four fingers of one hand performed a slight button press. With MEG we demonstrate reliable discrimination of single button presses performed with the thumb, the index, the middle or the little finger (average over all subjects and fingers 57%, best subject 70%, empirical guessing level: 25.1%). EEG decoding performance was less robust (average over all subjects and fingers 43%, best subject 54%, empirical guessing level 25.1%). Spatiotemporal patterns of amplitude variations in the time series provided best information for discriminating finger movements. Non-phase-locked changes of mu and beta oscillations were less predictive. Movement related high gamma oscillations were observed in average induced oscillation amplitudes in the MEG but did not provide sufficient information about the finger's identity in single trials. Importantly, pre-movement neuronal activity provided information about the preparation of the movement of a specific finger. Our study demonstrates the potential of non-invasive MEG to provide informative features for individual finger control in a Brain-Machine Interface neuroprosthesis.

Bending-related faulting and mantle serpentinization at the Middle America trench

The dehydration of subducting oceanic crust and upper mantle has been inferred both to promote the partial melting leading to arc magmatism and to induce intraslab intermediate-depth earthquakes, at depths of 50-300 km. Yet there is still no consensus about how slab hydration occurs or where and how much chemically bound water is stored within the crust and mantle of the incoming plate. Here we document that bending-related faulting of the incoming plate at the Middle America trench creates a pervasive tectonic fabric that cuts across the crust, penetrating deep into the mantle. Faulting is active across the entire ocean trench slope, promoting hydration of the cold crust and upper mantle surrounding these deep active faults. The along-strike length and depth of penetration of these faults are also similar to the dimensions of the rupture area of intermediate-depth earthquakes.

Activation of myocardial angiogenesis and upregulation of fibroblast growth factor-2 in transmyocardial-revascularization-treated mice

OBJECTIVE

To evaluate the growth factor responses associated with myocardial angiogenesis.

DESIGN

Mice were treated with transmyocardial revascularization (TMR) and evaluated for angiogenic and growth factor responses.

METHODS

TMR was performed via thoractomy with a 27 g needle. At 2, 5, and 7 days post-treatment, hearts were removed from the TMR treated and control groups, then assayed for angiogenesis, fibroblast growth factor (FGF)-2 expression and vascular endothelial cell growth factor (VEGF) expression.

RESULTS

TMR caused an angiogenic reaction in the myocardial blood vessels at 7 days post-TMR treatment. Elevated FGF-2 corresponded with increased TMR related angiogenesis. VEGF levels only increased in hearts that were prewounded then TMR treated.

CONCLUSIONS

The data show that TMR stimulates myocardial angiogenesis. The angiogenic reaction is mediated by FGF-2 which increased in most experimental treatment groups. The VEGF response was more specific, requiring prewounding then TMR treatment for a VEGF increase.

Failure to transmit disease from gray tremor mutant mice

Mice homozygous for mutant alleles at the gray tremor (gt) locus develop a marked non-intention tremor beginning at 8 days of age. Most homozygous mice die by 3 months. Homozygotes exhibit intense vacuolation of the central nervous system gray matter and vacuolation and hypomyelination of some white matter tracts. Based on neuropathological similarities with scrapie, other investigators inoculated wild-type mice with gray tremor brain homogenates to test the hypothesis of transmissibility. Published reports indicated that spongiform encephalopathy (R. L. Sidman, H. C. Kinney, and H. O. Sweet, Proc. Natl. Acad. Sci. USA 82:253-257, 1985) and disease, including hind limb paralysis in NFS mice (P. M. Hoffman, R. G. Rohwer, C. MacAuley, J. A. Bilello, J. W. Hartley, and H. C. Morse III, Proc. Natl. Acad. Sci. USA 84:3866-3870, 1987), were transmitted by inoculation of gt/gt brain homogenates. In our hands, however, no NFS/NCr animals inoculated intracerebrally with gt/gt or +/+ brain preparations showed any signs of disease or pathological changes in the brain. Positive transmission by other investigators may reflect the microbiological status of their donor or recipient mice.

The effect of preoperative tranexamic acid on blood loss after cardiac operations in children

Children undergoing cardiac operations in which cardiopulmonary bypass is used are at risk of significant postoperative blood loss. The acquired coagulopathy is complex but is thought to be due, in part, to excessive fibrinolysis. We examined the possibility of reducing postoperative blood loss in children by using the antifibrinolytic drug tranexamic acid. Using a prospective, randomized, double-blind study design, we administered a single dose of tranexamic acid (50 mg/kg intravenously) or saline placebo, before skin incision, in 88 children undergoing cardiac operations. Post-operative blood loss and fluid replacement were recorded for the next 24 hours. In addition, hemoglobin, platelet counts, and coagulation measures were recorded every 6 hours. When all patients were examined, there was no significant difference in postoperative blood loss between the treated and placebo groups (21.2 +/- 12 ml/kg per 24 hours, tranexamic acid, vs 27.2 +/- 20.3 mls/kg per 24 hours, placebo). However, when the children with cyanosis were analyzed separately, there was a highly significant difference in blood loss between the groups during the first 6 hours (11.2 +/- 3.7 ml/kg per 6 hours, tranexamic acid, vs 27.2 +/- 11.4 mls/kg per 6 hours, placebo; p < 0.002), as well as the overall 24 hour study period (23.7 +/- 7.5 mls/kg per 24 hours, tranexamic acid, vs 48.9 +/- 27.6 mls/kg per 24 hours, placebo; p < 0.02). Also significantly less blood and blood products were administered to the treated cyanosed group. Tranexamic acid produced a significant reduction in postoperative blood loss and blood product requirements in children with cyanosis undergoing heart operations. The drug had no effect in children without cyanosis or those requiring a second thoracotomy.

Continuous quality improvement: a perioperative nursing approach

This article describes in detail the steps taken in the Operating Room at the Toronto Hospital in implementing a Continuous Quality Management framework. Focusing on active participation, all levels of the O.R. staff worked through a process of identifying, developing, measuring and evaluating standards of practice. A step by step framework was followed in order to monitor current standards and develop new ones, thereby complying with the institution's mandate of supporting Continuous Quality Improvement.

[Comparison of a long-acting and short-acting GnRH analog in combination with gonadotropins in in vitro fertilization under various indications]

The occurrence of a premature luteinizing hormone (LH)-surge during gonadotropin stimulation for in-vitro fertilization leads to cancellation of the cycle. Moreover, insufficient follicular maturation is often caused by elevated basal gonadotropin levels. Therefore the gonadotropin releasing hormone (GnRH) agonist, D-TRP6-LHRH, was applied to patients exhibiting premature LH-surges, hyperandrogenemia or incipient premature menopause. 119 cycles were treated, using a long-acting versus a short-acting GnRH agonistic analogue. In protocol 1, patients received daily subcutaneous injections of 100-500 micrograms of a short-acting compound. In protocol 2, a long-acting bolus of 3.2 mg was given intramuscularly. Concomitant human gonadotropin (HMG) stimulation started in protocol 1 after clinical and biochemical evidence of pituitary suppression and in protocol 2 after a fixed suppression interval of 14 days. In protocol 1 higher estrogen levels were reached with more oocytes harvested. The pregnancy rate per transfer was increased from 3.5% to 18%, with most pregnancies occurring with protocol 2. The cancellation rate of 13.4% was mainly due to insufficient follicular development in patients, in whom premature menopause was suspected. Hyper-androgenemic patients with an elevated LH/FSH-ratio exhibited the best follicular recruitment with the highest pregnancy rate of 25% per transfer. Thus combined GnRH-agonist/gonadotropin stimulation offers a causal treatment for patients susceptible to premature LH-surges and for hyperandrogenemic patients.

Combined GnRH-agonist/gonadotrophin stimulation for in-vitro fertilization

The occurrence of a premature luteinizing hormone (LH) surge during gonadotrophin stimulation for in-vitro fertilization leads to cancellation of the cycle. Moreover, insufficient follicular maturation is often caused by elevated basal gonadotrophin levels. Therefore, the gonadotrophin-releasing hormone (GnRH) agonist, D-Trp-6-LHRH, was applied to patients exhibiting premature LH surges, hyperandrogenaemia or incipient premature menopause. A total of 119 cycles were treated using a long-acting versus a short-acting GnRH agonistic analogue. In protocol 1, patients received daily s.c. injections of 100-500 micrograms of a short-acting compound. In protocol 2, a long-acting bolus of 3.2 mg was given i.m. Concomitant human gonadotrophin stimulation was started in protocol 1 after clinical and biochemical evidence of pituitary suppression and in protocol 2 after a fixed suppression interval of 14 days. In protocol 1, higher oestrogen levels were reached with more oocytes harvested. The pregnancy rate per transfer was increased from 3.5 to 18%, with most pregnancies occurring with protocol 1. The cancellation rate of 13.4% was mainly due to insufficient follicular development in patients in whom premature menopause was suspected. Hyperandrogenaemic patients with an elevated LH/FSH ratio exhibited the best follicular recruitment with the highest pregnancy rate of 25% per transfer. Thus, combined GnRH-agonist/gonadotrophin stimulation offers a causal treatment for patients susceptible to premature LH surges and for hyperandrogenaemic patients.

Monoclonal antibodies against glycophorin A

Two mouse IgM monoclonal antibodies, 177.1 and 179.3, are directed against glycophorin A, the major sialoglycoprotein of human erythrocytes. Both antibodies agglutinate blood group M and N erythrocytes equally well, both before and after treatment with neuraminidase or trypsin, but fail to agglutinate erythrocytes treated with papain. Antibody 179.3 agglutinates MiVII(K.T.) cells, whose glycophorin A probably contains some alterations in amino acid sequence between residues 46-56, but antibody 177.1 does not agglutinate these cells. Neither antibody agglutinates En(a-)G.W. cells, which lack glycophorin A completely. The hemagglutinating activity of antibody 177.1 is inhibited by purified glycophorin A and its chymotryptic glycopeptides CH1 (amino acid residues 1-64) and CH3 (amino acid residues 35-64), whereas the hemagglutinating activity of 179.3 is inhibited weakly by glycophorin A but not by chymotryptic peptides. These antibodies both are classified as anti-En(a-)FS but apparently bind different epitopes.

Measurement Of Asphaltene Flocculation In Bitumen Solutions

Abstract

The ability to transport bitumen, in solutions of low viscosity solvents, can be seriously affected by asphaltene precipitation. Solvents differ dramatically in their ability to dissolve asphaltenes and often those which are inexpensive and readily available have poor solvating properties. Titrating a solution of bitumen in the solvent of interest with pentane and observing the onset of asphaltene flocculation yields the flocculation threshold for that solution. This information is often more useful than merely the dissolution properties of the solvent for asphaltenes or the standard asphaltene precipitation determination. A series of experiments were performed with various solvents utilizing apparatus assembled in our laboratory which measured the increase in light scattering at the onset of flocculation. Plots of the information obtained from the titration curves were constructed allowing solvent effects to be readily observed and measured.

Data is presented which compares the ability of n-pentane to initiate the flocculation of asphaltenes from various bitumen and crude oils indicating the stability to the asphaltene solution in the oil. The solubilizing characteristics of several solvents for an Athabasca bitumen are presented showing that a high aromatics diesel fuel is a better solubilizer than toluene. Some chemical additives such as surfactants, acids, and bases were found to delay the onset of asphaltene flocculation in the bitumen solutions.

Introduction

Solvent dilution is an important technique for viscosity reduction of heavy oil, bitumens and upgrading residues to aid in removal of water and solid contaminants or to improve the transport properties of the oil.The choice of a solvent depends upon its dissolution capability to ensure that asphaltenes are not precipitated producing additional problems. Often the most appropriate solvents are in short supply or not available(1) and information about the solvating power of readily available solvents is desired. A measurement of the asphaltene content by standard methods(2) generally does not provide the information about flocculation or precipitation kinetics which are of practical importance.

Work by Bichard(3) and Hotier and Robin(4) discussed methods for the study and measurement of solvating power, flocculation properties, and precipitation potentials by titrating samples with a solvent and observing the onset of asphaltene flocculation and precipitation. The initial studies of flocculation were accomplished by means of spot tests or optical microscopy(3–5) but these are tedious and time-consuming and often difficult to reproduce. The spot formed by placing a drop of a solution on filter paper can be compared with a series of reference spots to estimate the degree of asphaltene precipitation. The spot test is based on the fact that flocculated asphaltene particles diffuse more slowly than the surrounding liquid when the mixture is placed on the filter paper. When flocculated particles form in the solution a dark region is observed in the middle of the spot. This test is the basis of ASTM method D2781 for measuring the compatibility of oils. In optical microscopy as described by Bichard(3) the particles in suspension are observed directly within an aliquot of the mixture when placed on a microscope slide.

Retrovirus-like particles in salivary glands, prostate and testes of AIDS patients

AIDS associated retrovirus-like particles were identified in the salivary gland, prostate and/or testicle of two AIDS patients. These findings further suggest that saliva and semen may transmit the infection to susceptible individuals.

Thoracic manifestations of the acquired immune deficiency syndrome

The acquired immune deficiency syndrome is characterized by the development of multiple recurrent opportunistic infections or unusual neoplasms in individuals with no prior history of immune suppression. This report summarizes the thoracic diseases encountered in such patients before after death and the role of diagnostic techniques currently used in the evaluation of thoracic disease in 15 patients with this syndrome. Efficacy of treatment was determined by correlation with postmortem findings in all patients. Pulmonary disease was present in all 15 patients and necessitated 23 transbronchial biopsies in 11 patients. Pneumocystis carinii pneumonia and cytomegalovirus pneumonia were the most common findings. Nine open lung biopsies in eight patients disclosed either Pneumocystis carinii pneumonia or Kaposi's sarcoma. Esophageal disease was present in four patients, and endoscopic evaluation demonstrated Candida esophagitis (two), esophageal Kaposi's sarcoma (one), and cytomegalovirus esophagitis and Kaposi's sarcoma (one). Mean time to death from diagnosis of acquired immune deficiency syndrome was 7.7 months, with respiratory insufficiency being the most common cause of death (9/15, 60%). Pneumocystis carinii pneumonia was successfully eradicated in 70% of the patients. Candida esophagitis was ameliorated in both patients with the disease. Unsuspected pulmonary Kaposi's sarcoma, cytomegalovirus pneumonitis, and other infectious pathogens were documented at autopsy. These data reveal that Pneumocystis carinii pneumonia and Candida esophagitis can be managed successfully in patients with acquired immune deficiency syndrome if appropriately diagnosed. The major cause of death in this series was pulmonary insufficiency, often the result of severe cytomegalovirus infection. Thoracic surgeons must continue to play an aggressive and important role in the early diagnosis and management of potentially treatable pulmonary and esophageal disease in these patients.

Melatonin inhibition and pinealectomy enhancement of 7,12-dimethylbenz(a)anthracene-induced mammary tumors in the rat

The effects of the pineal hormone, melatonin, and of pinealectomy on the incidence of mammary adenocarcinoma in Sprague-Dawley rats treated with 7,12-dimethylbenz(alpha)-anthracene (DMBA) were investigated. Melatonin (2.5 mg/kg), begun on the same day as DMBA (5 mg) treatment and given daily in the afternoon for 90 days, significantly reduced the incidence of mammary tumors from 79% (control) to 20% (treated) (p less than 0.002). Rats pinealectomized at 20 days of age and treated with 7 mg of DMBA at 50 days of age had a higher incidence of tumors (88%) compared to control animals (22%). Fifteen mg of DMBA, which resulted in a higher incidence of tumors, reduced the difference between pinealectomized and control animals. Melatonin only partially reversed the effects of pinealectomy, reducing the incidence from 87% (pinealectomy alone) to 63% (pinealectomy plus melatonin); however, the tumor incidence was still lower (27%) in nonpinealectomized, melatonin-treated animals. Assessment of plasma prolactin, luteinizing hormone, follicle-stimulating hormone, estradiol, and cortisol in DMBA-treated tumor-free and tumor-bearing animals revealed a significantly lower plasma prolactin concentration [27 +/- 5 (S.E.) ng/ml] in melatonin-treated animals as compared to vehicle-treated animals [65 +/- 8 ng/ml]. The concentration of plasma prolactin was less in melatonin-treated, pinealectomized rats (55 +/- 10 ng/ml) as compared to vehicle-treated, pinealectomized animals (101 +/- 13 ng/ml). Other hormones were not affected by melatonin treatment. These data support the hypothesis that melatonin inhibits the development of DMBA-induced mammary tumors in the rat while removal of the pineal gland stimulates development of such tumors. Additionally, these experiments provide evidence that these effects may be mediated by a suppression of plasma prolactin levels.