Associations Between End-Tidal Carbon Dioxide During Pediatric Cardiopulmonary Resuscitation, Cardiopulmonary Resuscitation Quality, and Survival

BACKGROUND

Supported by laboratory and clinical investigations of adult cardiopulmonary arrest, resuscitation guidelines recommend monitoring end-tidal carbon dioxide (ETCO2) as an indicator of cardiopulmonary resuscitation (CPR) quality, but they note that "specific values to guide therapy have not been established in children."

METHODS

This prospective observational cohort study was a National Heart, Lung, and Blood Institute-funded ancillary study of children in the ICU-RESUS trial (Intensive Care Unit-Resuscitation Project; NCT02837497). Hospitalized children (≤18 years of age and ≥37 weeks postgestational age) who received chest compressions of any duration for cardiopulmonary arrest, had an endotracheal or tracheostomy tube at the start of CPR, and evaluable intra-arrest ETCO2 data were included. The primary exposure was event-level average ETCO2 during the first 10 minutes of CPR (dichotomized as ≥20 mm Hg versus <20 mm Hg on the basis of adult literature). The primary outcome was survival to hospital discharge. Secondary outcomes were sustained return of spontaneous circulation, survival to discharge with favorable neurological outcome, and new morbidity among survivors. Poisson regression measured associations between ETCO2 and outcomes as well as the association between ETCO2 and other CPR characteristics: (1) invasively measured systolic and diastolic blood pressures, and (2) CPR quality and chest compression mechanics metrics (ie, time to CPR start; chest compression rate, depth, and fraction; ventilation rate).

RESULTS

Among 234 included patients, 133 (57%) had an event-level average ETCO2 ≥20 mm Hg. After controlling for a priori covariates, average ETCO2 ≥20 mm Hg was associated with a higher incidence of survival to hospital discharge (86/133 [65%] versus 48/101 [48%]; adjusted relative risk, 1.33 [95% CI, 1.04-1.69]; P=0.023) and return of spontaneous circulation (95/133 [71%] versus 59/101 [58%]; adjusted relative risk, 1.22 [95% CI, 1.00-1.49]; P=0.046) compared with lower values. ETCO2 ≥20 mm Hg was not associated with survival with favorable neurological outcome or new morbidity among survivors. Average 2 ≥20 mm Hg was associated with higher systolic and diastolic blood pressures during CPR, lower CPR ventilation rates, and briefer pre-CPR arrest durations compared with lower values. Chest compression rate, depth, and fraction did not differ between ETCO2 groups.

CONCLUSIONS

In this multicenter study of children with in-hospital cardiopulmonary arrest, ETCO2 ≥20 mm Hg was associated with better outcomes and higher intra-arrest blood pressures, but not with chest compression quality metrics.

A Novel Embedded Feature Selection and Dimensionality Reduction Method for an SVM Type Classifier to Predict Periventricular Leukomalacia (PVL) in Neonates

This paper is concerned with the prediction of the occurrence of periventricular leukomalacia (PVL) in neonates after heart surgery. Our prior work shows that the Support Vector Machine (SVM) classifier can be a powerful tool in predicting clinical outcomes of such complicated and uncommon diseases, even when the number of data samples is low. In the presented work, we first illustrate and discuss the shortcomings of the traditional automatic machine learning (aML) approach. Consequently, we describe our methodology for addressing these shortcomings, while utilizing the designed interactive ML (iML) algorithm. Finally, we conclude with a discussion of the developed method and the results obtained. In sum, by adding an additional (Genetic Algorithm) optimization step in the SVM learning framework, we were able to (a) reduce the dimensionality of an SVM model from 248 to 53 features, (b) increase generalization that was confirmed by a 100% accuracy assessed on an unseen testing set, and (c) improve the overall SVM model's performance from 65% to 100% testing accuracy, utilizing the proposed iML method.

Recent developments and knowledge in pseudocereals including technological aspects

Amaranth, buckwheat, quinoa, and less known, canihua are the most important pseudocereals. Their high nutritional value is well recognized and they are increasingly used for the development of a wide range of starch-based foods, which has been fostered by intensified research data performed in recent years. In addition to health driven motivations, also environmental aspects like the ongoing climate change are an important stimulus to increase agricultural biodiversity again. As pseudocereals are botanically classified as dicotyledonous plants their chemical, physical and processing properties differ significantly from the monocotyledonous cereals. Most important factors that need to be addressed for processing is their smaller seed kernel size, their specific starch structure and granule architecture, their gluten-free protein, but also their dietary fibre and secondary plant metabolites composition. This review gives a condensed overview of the recent developments and gained knowledge with special attention to the technological and food processing aspects of these pseudocereals.

Differential diagnosis of auditory hallucinations in teenagers. Assessment and difficulties: Case report of a 13 year old patient

Introduction

Learning from a case of a 13 year old patient with auditory hallucinations for 2 months, admitted to the hospital due to suicidal ideation. Her mother had been diagnosed with Lupus and OCD. Her mood had been low for several months, probable mild intellectual disability.

Objectives

Learn how to assess auditory hallucinations and possible new onset psychotic symptoms in teenagers. Learn about different levels of care involved. Discuss differential diagnosis and future directions and treatment.

Methods

Description of the case. Differential diagnosis: Obsessive compulsive disorder, Major depressive disorder with Psychotic features, schizophrenia spectrum disorder, epilepsy or other neurologic disease, autoimmune disease, post-traumatic stress disorder… Tests and consults conducted by Neurology team Psychopharmacology description.

Results

Differential diagnosis: Obsessive compulsive disorder, Major depressive disorder with Psychotic features, schizophrenia spectrum disorder, epilepsy, autoimmune diseases like Lupus, post-traumatic stress disorder etc. Video EEG: normal. Brain MRI: normal Blood work unremarkable with positive ANA (titer 1:80). Work up, including lumbar puncture with autoimmune encephalitis and MS panels was negative. Psychopharmacology: Fluoxetine up to 40mg, and Aripiprazol up to 20mg without a good response. Possible sexual trauma was disclosed in a second hospitalization, months later.

Conclusions

Recommendation of assessing new onset of psychotic symptoms in detail to get a good diagnosis. Psychotic symptoms in young teenagers may occur as part of different presentations and it is important to provide a good follow up of the patient in order to provide the most accurate treatment.

Conflict of interest

Alicia Koplowitz Foundation

MLWAVE: A novel algorithm to classify primary versus secondary asphyxia-associated ventricular fibrillation

INTRODUCTION/HYPOTHESIS

The outcome of cardiopulmonary resuscitation (CPR) depends on timely recognition of the underlying cause of cardiac arrest. Ventricular fibrillation (VF) waveform analysis to differentiate primary VF from secondary asphyxia-associated VF may allow tailoring of therapies to improve cardiac arrest outcomes. Therefore, the primary goal of this investigation was to develop a novel technique utilizing wavelet synchrosqueezed transform (WSST) and decision-tree classifier that was specifically adapted to discriminate between these two incidents of VF.

METHODS

Secondary analytical investigation of electrocardiography (ECG) data obtained from swine models of either primary VF (n=18) or secondary asphyxia-associated VF (7min of asphyxia prior to VF induction; n=12). In the primary analysis, WSST technique was applied to the first 35s of the VF ECG signal to identify the most differentiating characteristics of the signal for use as features to develop a machine learning algorithm to classify the arrest as either primary VF vs. secondary asphyxia-associated VF. The performance of this new interactive Machine Learning algorithm with Wavelet Energy features of ECG (MLWAVE) was assessed using both classification accuracy and area under the receiver operating characteristic curve (AUCROC). To evaluate the validity of the new technique, the amplitude spectrum area (AMSA)-based technique, a well-established defibrillation classification method, was also applied to the same ECG signals. The classification accuracy and AUCROC were then compared between the two techniques.

RESULTS

For the primary analysis evaluating the first 35s of the VF waveform, the MLWAVE technique classified the type of VF with high accuracy (28/28 [100%], AUCROC: 1.00). The MLWAVE technique performed better than the AMSA technique across all comparisons, but given the small sample sizes, differences were not statistically significant (accuracy: 100% vs. 85.7%; p=0.24; AUCROC: 1.00 vs. 0.82; p=0.24).

CONCLUSION

This analytical investigation illustrates the advantages of the MLWAVE signal processing method which was associated with 100% accuracy in classifying the type of VF waveform: primary vs. asphyxia-associated. Such classification could lead to personalized tailoring of resuscitation (e.g., immediate defibrillation vs. continued CPR and treatment of reversible cardiac arrest causes before defibrillation) to improve outcomes for cardiac arrest.

Delayed and fractional use of enzymatic debridement with nexobrid for extensive burn injury: a case report

Selective enzymatic debridement is increasingly being used in cases of burn wounds. However, until now the use of Nexobrid has been limited to 15% of total body surface area (TBSA) and immediate use on admission day. A 61-year-old Caucasian male suffered a severe burn injury that affected 95% TBSA. After surgical escharotomy and tracheotomy on admission day, we successfully performed a fractional enzymatic debridement of 54% of the TBSA in three different sessions within four days. This case report reveals that a delayed and fractional application of Nexobrid to more than 15% TBSA is possible.

Quantitative [18F]Fluorodopa/PET and Histology of Fetal Mesencephalic Dopaminergic Grafts to the Striatum of MPTP-Poisoned Minipigs

The functional restoration of the dopamine innervation of striatum in MPTP-poisoned Göttingen minipigs was assessed for 6 months following grafting of fetal pig mesencephalic neurons. Pigs were assigned to a normal control group and a MPTP-poisoned group, members of which received no further treatment, or which received bilateral grafts to the striatum of tissue blocks harvested from E28 fetal pig mesencephalon with and without immunosuppressive treatment after grafting, or with additional co-grafting with immortalized rat neural cells transfected to produce GDNF. In the baseline condition, and again at 3 and 6 months postsurgery, all animals were subjected to quantitative [18F]fluorodopa PET scans and testing for motor impairment. At the end of 6 months, tyrosine hydroxylase (TH)-containing neurons were counted in the grafts by stereological methods. The MPTP poisoning persistently reduced the magnitude of k3D, the relative activity of DOPA decarboxylase in striatum, by 60%. Grafting restored the rate of [18F]fluorodopa decarboxylation to the normal range, and normalized the scores in motor function. The biochemical and functional recovery was associated with survival of approximately 100,000 TH-positive graft neurons in each hemisphere. Immunosuppression did not impart a greater recovery of [18F]fluorodopa uptake, nor were the number of TH-positive graft neurons or the volumes of the grafts increased in the immunosuppressed group. Contrary to expectation, co-grafting of transfected GDNF-expressing HiB5 cells, a rat-derived neural cell line, tended to impair the survival of the grafts with the lowest values for graft volumes, TH-positive cell numbers, behavioral scores, and relative DOPA decarboxylase activity. From the results we conclude that pig ventral mesencephalic allografts can restore functional dopamine innervation in adult MPTP-lesioned minipigs.

Faculty professional development in emergent pedagogies for instructional innovation in dental education

Innovative pedagogies have significantly impacted health professions' education, dental education included. In this context, faculty, defined in this study as instructor in higher education, has been increasingly required to hone their instructional skills. The purpose of this exploratory study was to share the design, implementation and preliminary outcomes of two programmes to enhance dental faculty's instructional skills, the Teaching and Learning Seminar Series and the Course Director Orientation. Data sources included faculty and student surveys developed and administered by the researchers; data extracted from the learning management system; reports from the learning analytics tool; and classroom observations. Participants' satisfaction, self-reported learning, instructional behavioural change, and impact on student learning behaviours and institutional practice were assessed borrowing from Kirkpatrick's 4-level model of evaluation of professional development effectiveness. Initial findings showed that faculty in both programmes reported positive learning experiences. Participants reported that the programmes motivated them to improve instructional practice and improved their knowledge of instructional innovation. Some faculty reported implementation of new instructional strategies and tools, which helped create an active and interactive learning environment that was welcomed by their students. The study contributes to literature and best practice in health sciences faculty development in pedagogy and may guide other dental schools in designing professional development programmes.

Advanced analytics for outcome prediction in intensive care units

In this paper we present a new expert knowledge based clinical decision support system for prediction of intensive care units outcome based on the physiological measurements collected during the first 48 hours of the patient's admission to the ICU. The developed CDSS algorithm is composed of several stages. First, we categorize the collected data based on the physiological organ that they represent. We then extract clinically relevant features from each data category and then rank these features based on their mutual information with the outcome. Then, we design an artificial neural network to serve as a classifier to detect patients at high risk of critical deterioration. We use the eight-fold cross validation method to test the developed CDSS classifier. The results from the classification show that the newly designed CDSS outperforms the widely used acuity scoring systems, SOFA and SAPS-III. The F-score classification result of our developed algorithms is 42% while the F-score results for SOFA and SAPS-III are 26% and 29% respectively.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

PET evaluation of the uptake of N-[11C]methyl CP-643,051, an NK1 receptor antagonist, in the living porcine brain

Antagonists of neurokinin receptors such as CP-643,051 are presently under investigation as potential antidepressants, but little is known about the brain uptake and distribution of these agents. We developed a method for the efficient N-[11C]methylation of CP-122,721, yielding the NK1 antagonist N-[11C]methyl CP-643,051. The brain uptake and distribution of N-[11C]methyl CP-643,051 were studied by positron emission tomography (PET) in the anaesthetized pig, first in a baseline condition, and again after displacement of specific binding with the NK1 receptor antagonist L-732,138 (0.6 mg/kg, i.v.). In order to validate this displacement procedure, we tested the effects of L-732,138 on cerebral blood flow (CBF) in one pig. We found that N-[11C]methyl CP-643,051 had a distribution volume close to 3 ml g(-1), and a binding potential (pB) of 0.3 in the pig striatum; this binding was displaceable by the L-732,138 pre-treatment, which evoked a small (10-20%) global increase in CBF. We conclude that of N-[11C]methyl CP-643,051 may serve as a lead structure for the development of PET NK-1 ligands of higher specific binding in vivo.

PET evaluation of a tetracyclic, atypical antidepressant, [N-methyl-11C]mianserin, in the living porcine brain

We synthesized [N-methyl-11C]mianserin by alkylation of N-desmethyl mianserin with [11C]methyl iodide followed by HPLC purification. We used PET for determining the regional cerebral pharmacokinetics of the radiotracer in anesthetized swine. [N-methyl-11C]Mianserin entered most brain regions readily (range of K1 values: 0.66-1.13), reaching highest levels in the basal ganglia and thalamus. The binding potential of [N-methyl-11C]mianserin was relatively low (range: 0.07-0.50), but regional differences were nonetheless observed, with highest values in the temporal cortex and lowest values in the brainstem. These PET findings, which are the first ones for a tetracyclic, antidepressant drug, show that [N-methyl-11C]mianserin has only a limited degree of regional specificity of binding in the living brain.

Positron emission tomography of hepatic first-pass metabolism of ammonia in pig

Hepatic first-pass metabolism plays a key role in metabolic regulation and drug metabolism. Metabolic processes can be quantified in vivo by positron emission tomography scanning (PET). We wished to develop a PET technique to measure hepatic first-pass metabolism of ammonia. Seven anaesthetised pigs were given positron-labelled ammonia, (13)NH(3), into the portal vein and into the vena cava as successive 2-min infusions followed by 22-min dynamic liver scanning. Vena cava infusion data were used to account for recirculation of tracer and metabolites following the portal vein infusion. The scan data were analysed by a model of sinusoidal zonation of ammonia metabolism with periportal urea formation and perivenous formation of glutamine. The hepatic extraction fraction of (13)NH(3) was 0.73+/-0.16 (mean+/-SD, n=7 pigs). Values of clearance of ammonia to urea and to glutamine were obtained, as were rate constants for washout of these two metabolites. Overall, the modelling showed half of the ammonia uptake to be converted to urea and half to glutamine. The washout rate constant for glutamine was about one-tenth of that for urea. We conclude that hepatic first-pass metabolism of ammonia was successfully assessed by PET.

Metabolites of (18)F-FDG and 3-O-(11)C-methylglucose in pig liver

PET uses (18)F-FDG widely to estimate glucose metabolism in vivo. Dynamic PET data are evaluated by kinetic models of the metabolic pathways. Knowledge of the metabolites of FDG is of critical importance for the interpretation of kinetic PET studies. The purpose of this study was to determine the metabolic pathways of FDG and 3-O-(11)C-methylglucose (MG) in liver tissue in vivo. It is usually assumed that MG is not metabolized and FDG is converted to (18)F-FDG-6-phosphate (FDG-6-P).

METHODS

The study was performed on 6 anesthetized 40-kg pigs that were given the 2 tracers intravenously. The content of metabolites was determined in successive liver tissue biopsies. Freeze-clamped liver tissue samples were subjected to extraction by acetonitrile at -5 degrees C to -10 degrees C, and extracts were analyzed by radio-high-performance liquid chromatography (radio-HPLC). The findings were identified by means of radio-HLPC measurements of the products of in vitro enzymatic reactions.

RESULTS

The applied extraction technique provided almost quantitative recovery of the radioactivity from tissue. After MG injection, only MG was detectable in the liver tissue; no labeled metabolites were found. After FDG injection, 2 metabolites were identified, FDG-6-P and 2-(18)F-fluoro-2-deoxy-6-phosphogluconate (FD-6-PG1). The tissue content of FDG increased rapidly, and, after 5 min, only FDG was identified; hereafter, the fraction of FDG decreased to approximately 40% of the tissue radioactivity after 180 min. After 20 min, FDG-6-P was found in each of the pigs and it increased throughout the measurement period of 180 min, with a somewhat slower rise at late time points. FD-6-PG1 began to appear in the liver tissue after 45 min and increased throughout the 180-min experiment, with the increase somewhat slower than that of FDG-6-P. After 180 min, approximately 40% of the metabolites was attributed to FD-6-PG1. The content of other metabolites was <2%, even after 180 min.

CONCLUSION

After the FDG injection, not only FDG-6-P but also FD-6-PG1 were formed in the liver. Any possible incorporation of FDG into glycogen was of minor importance.

FDOPA metabolism in the adult porcine brain: influence of tracer circulation time and VOI selection on estimates of striatal DOPA decarboxylation

Different methodologies for PET data analysis influence the magnitude of estimates of blood-brain transfer coefficients and rate constants for the metabolism of FDOPA in living striatum. We now test the effects on several kinetic parameters of automatic procedures for volume of interest (VOI) selection. We also tested the sensitivity of the estimates to dynamic frame sequence duration, and produced a standard method for minimizing the variations in physiological estimates for FDOPA kinetics in minipig brain. We used minipigs because our previous work has shown them to provide an appropriate animal model for study normal and pathological cerebral DOPA metabolism using PET. Time-activity curves in striatum of adult minipigs were acquired in VOIs defined manually on MR-images, or alternatively on the basis of the radioactivity concentration based on the most radioactive voxel in the last scan frame. For all frame sequences, the relative decarboxylase activity (k(3)(D)) declined significantly (P < 0.006) as the VOI threshold declined from 95 to 70% of the most radioactive voxel. Irrespective of VOI size, the magnitude of k(3)(D) declined significantly (P < 0.001) from 0.074+/-0.008 to 0.045+/-0.005 per min (mean+/-S.E.M.) as total sequence length increased from 60 to 120 min circulation. The method of VOI selection had no significant effect on the striatum decarboxylation index of FDOPA calculated relative to the radioactivity in cerebellum (k(3)(S)).

Internal consistency, intercriterion overlap and diagnostic efficiency of criteria sets for DSM-IV schizotypal, borderline, avoidant and obsessive-compulsive personality disorders

OBJECTIVE

To evaluate performance characteristics of DSM-IV Personality Disorders (PDs) criteria.

METHOD

Six hundred and sixty-eight adults recruited for the Collaborative Longitudinal Personality Disorders Study (CLPS) were assessed with diagnostic interviews.

RESULTS

Within-category inter-relatedness was evaluated by Cronbach's alpha and median intercriterion correlations (MIC). Cronbach's alpha ranged from 0.47 to 0.87 (median=0.71); seven of the 10 PDs had alphas greater than 0.70. Between-category criterion overlap was evaluated by "inter-category" intercriterion correlations between all PD pairs (ICMIC). ICMIC values (median=0.08) were lower than MIC values (median=0.23). Diagnostic efficiency statistics (sensitivity, specificity, positive predictive power and negative predictive power were calculated for schizotypal, borderline, avoidant and obsessive-compulsive PDs.

CONCLUSION

DSM-IV PD criteria sets have some convergent validity and discriminant validity: criteria for individual PDs correlate better with each other than with criteria for other PDs. Diagnostic efficiency statistics provide guidance regarding usefulness of criteria for inclusion or exclusion.

[14C]Serotonin uptake and [O-methyl-11C]venlafaxine kinetics in porcine brain

As part of our program of developing PET tracers for neuroimaging of psychotropic compounds, venlafaxine, an antidepressant drug, was evaluated. First, we measured in vitro rates of serotonin uptake in synaptosomes prepared from selected regions of porcine brain. Then, we determined the pharmacokinetics of venlafaxine, [O-methyl-11C]-labeled for PET. Synaptosomal studies showed that the active uptake of [14C]5-HT differed markedly between brain regions, with highest rates in hypothalamus, raphé region, and thalamus, and lowest rates in cortex and cerebellum. PET studies showed that the unidirectional rate of uptake of [O-methyl-11C]venlafaxine from blood to brain was highest in the hypothalamus, raphé region, thalamus and basal ganglia and lowest in the cortex and cerebellum. Under normal physiological conditions, the capillary permeability-surface area (PS) product for [O-methyl-11C]venlafaxine could not be estimated, because of complete flow-limitation of the cerebral uptake. Nevertheless, a correlation occurred between the apparent partition volume of the radiotracer and the rate of active uptake of 5-HT in selected regions of the porcine brain. During hypercapnia, limitations of blood-brain transfer were observed, giving PS-products for water that were only ca. 50% higher than those of venlafaxine. Thus, under normal physiological conditions, the rate of uptake of venlafaxine from blood into brain is completely flow-limited.

Normalization of markers for dopamine innervation in striatum of MPTP-lesioned miniature pigs with intrastriatal grafts

As part of the DaNeX study, the uptake and binding of several positron emitting tracers was recorded in brain of healthy Göttingen minipigs, in minipigs with a syndrome of parkinsonism due to MPTP intoxication, and in parkinsonian minipigs which had received intrastriatal grafts of mesencephalic neurons from fetal pigs. The specific binding of [11C]NS 2214 to catecholamine uptake sites was reduced by two thirds in striatum of the intoxicated animals, while the rate constant for the decarboxylation of [18F]fluorodopa was reduced by 50% in the intoxicated animals. Several months after grafting, both pre-synaptic markers of dopamine fibres were normal in striatum. Dopamine depletion or grafting were without effect on the cerebral perfusion rate, measured with [15O]-water, did not alter the rate of oxygen metabolism (CMRO2) in brain, and did not alter the binding potential of tracers for dopamine D1 or D2 receptors in pig striatum. However, the grafting was associated with a local increase in the binding of [11C]PK 11195, a tracer for reactive gliosis, suggesting that an immunological reaction occurs at the site of graft, which might potentially have reduced the graft patency. However, this apparent immunological response did not preclude the re-establishment of normal [18F]fluorodopa and [11C]NS 2214 uptake in the allografted striatum.

Liver kinetics of glucose analogs measured in pigs by PET: importance of dual-input blood sampling

Metabolic processes studied by PET are quantified traditionally using compartmental models, which relate the time course of the tracer concentration in tissue to that in arterial blood. For liver studies, the use of arterial input may, however, cause systematic errors to the estimated kinetic parameters, because of ignorance of the dual blood supply from the hepatic artery and the portal vein to the liver.

METHODS

Six pigs underwent PET after [15O]carbon monoxide inhalation, 3-O-[11C]methylglucose (MG) injection, and [18F]FDG injection. For the glucose scans, PET data were acquired for 90 min. Hepatic arterial and portal venous blood samples and flows were measured during the scan. The dual-input function was calculated as the flow-weighted input.

RESULTS

For both MG and FDG, the compartmental analysis using arterial input led to systematic underestimation of the rate constants for rapid blood-tissue exchange. Furthermore, the arterial input led to absurdly low estimates for the extracellular volume compared with the independently measured hepatic blood volume of 0.25 +/- 0.01 mL/mL (milliliter blood per milliliter liver tissue). In contrast, the use of a dual-input function provided parameter estimates that were in agreement with liver physiology. Using the dual-input function, the clearances into the liver cells (K1 = 1.11 +/- 0.11 mL/min/mL for MG; K1 = 1.07 +/- 0.19 mL/min/mL for FDG) were comparable with the liver blood flow (F = 1.02 +/- 0.05 mL/min/mL). As required physiologically, the extracellular volumes estimated using the dual-input function were larger than the hepatic blood volume. The linear Gjedde-Patlak analysis produced parameter estimates that were unaffected by the choice of input function, because this analysis was confined to time scales for which the arterial-input and dual-input functions were very similar.

CONCLUSION

Compartmental analysis of MG and FDG kinetics using dynamic PET data requires measurements of dual-input activity concentrations. Using the dual-input function, physiologically reasonable parameter estimates of K1, k2, and Vp were obtained, whereas the use of conventional arterial sampling underestimated these parameters compared with independent measurements of hepatic flow and hepatic blood volume. In contrast, the linear Gjedde-Patlak analysis, being less informative but more robust, gave similar parameter estimates (K, V) with both input functions.

The Collaborative Longitudinal Personality Disorders Study: reliability of axis I and II diagnoses

Both the interrater and test-retest-retest reliability of axis I and axis II disorders were assessed using the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) and the Diagnostic Interview for DSM-IV Personality Disorders (DIPD-IV). Fair-good median interrater kappa (.40-.75) were found for all axis II disorders diagnosed five times or more, except antisocial personality disorder (1.0). All of the test-retest kappa for axis II disorders, except for narcissistic personality disorder (1.0) and paranoid personality disorder (.39), were also found to be fair-good. Interrater and test-retest dimensional reliability figures for axis II were generally higher than those for their categorical counterparts; most were in the excellent range (> .75). In terms of axis I, excellent median interrater kappa were found for six of the 10 disorders diagnosed five times or more, whereas fair-good median interrater kappa were found for the other four axis I disorders. In general, test-retest reliability figures for axis I disorders were somewhat lower than the interrater reliability figures. Three test-retest kappa were in the excellent range, six were in the fair-good range, and one (for dysthymia) was in the poor range (.35). Taken together, the results of this study suggest that both axis I and axis II disorders can be diagnosed reliably when using appropriate semistructured interviews. They also suggest that the reliability of axis II disorders is roughly equivalent to that reliability found for most axis I disorders.