Effect of anatomic distribution of pulmonary emboli on interobserver agreement in the interpretation of pulmonary angiography

OBJECTIVE: This study examines the anatomic distribution of emboli on pulmonary angiography and attempts to determine the relationship of vessel size to interobserver agreement, two factors having important implications in comparing pulmonary angiography with cross-sectional imaging for pulmonary embolism. MATERIALS AND METHODS: One hundred twenty-five consecutive pulmonary angiograms were reviewed retrospectively by three interventional radiologists. Initial interpretations were recorded and compared to determine interobserver agreement on a per-patient and per-embolus basis. Discordant interpretations were reviewed by all radiologists for a consensus interpretation. RESULTS: Unanimous per-patient agreement occurred in 91% (114/125) of initial interpretations. The largest artery containing acute pulmonary embolism was segmental or larger in 24 patients (83% of patients with acute positive findings, 19% of all patients) and subsegmental in only five patients (17% and 4%, respectively). On a per-patient basis, initial interobserver agreement averaged 45% and unanimous consensus agreement was achieved for 79% of patients having isolated subsegmental pulmonary embolism. Consensus readings altered initial per-patient interpretations for 30% of patients having only subsegmental pulmonary embolism; per-embolus interpretations were altered for 37% of all subsegmental emboli. CONCLUSION: Subsegmental emboli occurring as isolated findings are relatively rare. Approximately one third of subsegmental emboli and one third of patients having isolated subsegmental emboli may be initially misdiagnosed on pulmonary angiography. Objections to cross-sectional imaging for pulmonary embolism based on the inability to detect subsegmental pulmonary embolism when compared with pulmonary angiography should be reexamined with this data in mind.     

The sleep of abstinent pure primary alcoholic patients: natural course and relationship to relapse

Sleep in male pure primary alcoholic inpatients was examined at a mean of 16 days (n = 29), 19 weeks (n = 29), 14 months (n = 9), and 27 months (n = 4) of abstinence. Results were as follows: (1) the sleep of abstinent alcoholic patients is short, fragmented, and shallow early in abstinence; (2) a patient's sleep improves slowly over at least the first year of abstinence; however, (3) some facets of a patient's sleep remain abnormal even after 27 months of abstinence; (4) insomnia and sleep fragmentation after approximately 5 months of abstinence may be related to relapse by 14 months. The mechanism underlying the relationship between sleep and withdrawal in alcoholic patients is not well understood, and the issue of treating sleep problems as an adjunct to prevention of relapse warrants further investigation.     

Tracer kinetic modeling of the 5-HT1A receptor ligand [carbonyl-11C]WAY-100635 for PET

[Carbonyl-11C]WAY-100635 is a promising PET radioligand for the 5-HT1A receptor, having demonstrated more favorable characteristics for in vivo imaging than the previously available [O-methyl-11C]WAY-100635. The current study evaluates different tracer kinetic modelling strategies for the quantification of 5-HT1A receptor binding in human brain. Mathematical modelling of the carbonyl-labeled radiotracer is investigated using compartmental structures, including both plasma input and reference tissue approaches. Furthermore, the application of basis function methods allows for the investigation of parametric imaging, providing functional maps of both delivery and binding of the radioligand. Parameter estimates of binding from normal volunteers indicate a low intra- versus a high intersubject variability. It is concluded that a simplified reference tissue approach may be used to quantify 5-HT1A binding either in terms of ROI data or as parametric images.     

Coupling of the human Y2 receptor for neuropeptide Y and peptide YY to guanine nucleotide inhibitory proteins in permeabilized SMS-KAN cells

This study of location information involved in information persistence used the partial-report paradigm. Six subjects were asked on 144 trials to recall positions of dots presented in a display. The subjects were instructed to maintain only information on location (but not on identity information) of the presented dots until a partial-report cue was introduced. The effects of display duration (50, 200, and 350 msec.) and cue delay (interval between the display offset and the onset of the partial-report cue: 50, 250, and 500 msec.) were examined. Analysis showed effect of cue delay on partial-report performance decreased as the duration of display increased so performance was negatively affected by the cue delay only when the subject was exposed to the presented dots for 50 msec. Contrarily, partial-report performance did not decline much for a 200-msec. duration and showed little variation in a 350-msec. duration, even though the cue delay increased. Consequently, the decay of the information on location mediating partial-report performance about dots varies with duration of display.     

Retrograde coronary venous infusion of ethanol for ablation of canine ventricular myocardium

INTRODUCTION: Permanent cure of reentrant ventricular tachycardia (VT) associated with coronary artery disease is difficult to achieve. Retrograde coronary venous infusion of ethanol for ablation of ventricular myocardium associated with reentrant tachyarrhythmias has several potential advantages, including use of physiologic mapping techniques and production of deeper, wider necrotic zones. METHODS AND RESULTS: Nine anesthetized dogs had baseline hemodynamic measurement, left ventriculography, coronary arteriography, occlusive coronary venography, and programmed electrical stimulation of the right ventricular apex and outflow tract. A balloon-tipped infusion catheter was advanced into a distal coronary venous branch, the balloon slowly inflated, and pure ethanol infused at volumes of 1.5, 3, or 5 cc. Hemodynamic measurements, angiography, ventriculography, and programmed electrical stimulation were repeated immediately and 1 week following ablation. Formalin-perfused hearts were serially sectioned and lesion volumes determined. Histologic examination of ablation beds then was performed. No significant difference was found in any hemodynamic measurement before or after ablation. Coronary arteriograms and left ventriculograms were unchanged after ablation. Nonsustained VT occurred in eight dogs during ethanol infusion; however, VT was not inducible in any dog before or after ablation. Infusion volumes of 3 cc or more were required to produce transmural lesions. CONCLUSION: Retrograde coronary venous infusions of ethanol using a balloon-tipped infusion catheter were effective in ablating ventricular myocardium. Retrograde chemical ablation did not itself result in inducible VT or adversely affect hemodynamic measurements or coronary arteries. Transmural myocardial necrosis, necessary in the ablation of VT associated with coronary artery disease, can be produced by higher infusion volumes.     

Evidence for the involvement of phospholipase A2 mechanisms in the development of stimulant sensitization

Evidence suggests that phospholipase A2 (PLA2) activation is involved in numerous neuroplastic phenomena, including long-term potentiation. Considering the pharmacological similarities between long-term potentiation and stimulant sensitization, it seems possible that PLA2 inhibition activity also might have a role in the induction of stimulant sensitization. In this study, we have investigated whether PLA2 inhibition, by quinacrine, has any effects on stimulant-induced behavioral sensitization. Both locomotor and stereotypic behavioral sensitization were dose-dependently blocked in rats pretreated with quinacrine (8-25 mg/kg i.p.) 15 min before cocaine (30 mg/kg i.p.), when tested with cocaine (15 mg/kg i.p) 72 hr later. Similar results also were found with d-amphetamine (2 mg/kg i.p.) sensitization using a 10-day treatment regimen with testing on day 11. The ability of PLA2 activation, by melittin, to produce cocaine sensitization also was tested. Local injections of melittin (0.1 microgram/0.4 microliter) into the ventral tegmental area sensitized the subsequent stimulation of locomotor activity, stereotypy and nucleus accumbens dopamine release by cocaine, when tested 72 hr later. Local injections of melittin (0.1-1.0 microgram/0.8 microliter) into the nucleus accumbens had a moderate sensitizing effect on locomotion. Quinacrine (16 mg/kg) pretreatment 45 min before intraventral tegmental area melittin injection significantly decreased melittin-induced sensitization of the locomotor and stereotypy response to cocaine. These results indicate that PLA2 activation may play a role in the induction of stimulant sensitization. It is proposed that PLA2 activity in mesolimbic dopamine neurons, at the level of the cell bodies and perhaps the nerve terminals, is involved in the biochemical mechanisms mediating the development of stimulant sensitization.     

Multiple emulsion-based systems carrying insulin: development and characterization

An insulin delivery system based on liquid surfactant membranes has been developed. The formulation was based on a w/o/w emulsion where an organic membrane separated two aqueous phases and the internal aqueous phase contained insulin. Sesame and cotton seed oils were used as organic membranes. In order to facilitate the transportation of glucose across the organic membrane various additives such as calcium stearate, lecithin, cholesterol, hexamine, stearic acid and glyceryl tristearate were used. The additives were found to be successful carriers for the transportation of glucose to the internal aqueous phase. Similarly, viscosity enhancers, e.g. cetostearyl alcohol, in the organic phase enhanced the immobilization of insulin. Various parameters affecting the stability of the emulsions were established. The developed system was characterized for insulin activity and insulin efflux profile.     

Renal lesion growth in children with tuberous sclerosis complex

Clostridium difficile-associated diarrhea (CDAD) is regarded as an emerging nosocomial infection. All patients positive for C. difficile in Sweden were recorded during 1995, including primary care patients. Those positive for toxin in feces were defined as CDAD cases. A total of 5,133 CDAD cases were recorded (58 per 100,000 inhabitants per year), as compared with 86 cases diagnosed in 1978 and 553 in 1983. CDAD was almost twice as prevalent as all (combined) diagnosed domestic cases of reportable bacterial and protozoal diarrhea. The age-specific incidence was little affected by gender but increased > 10-fold over the age range of 60-98 years. The differences in overall CDAD incidence were sixfold between counties and threefold between major hospitals. Among hospitalized patients the incidences were highest in geriatric/rehabilitation wards, followed by infectious diseases and internal medicine wards; 28% of all cases involved no recent hospitalization and were defined as community-acquired CDAD.