The attentional blink is related to phonemic decoding, but not sight-word recognition, in typically reading adults.

This research investigated the relationship between the attentional blink (AB) and reading in typical adults. The AB is a deficit in the processing of the second of two rapidly presented targets when it occurs in close temporal proximity to the first target. Specifically, this experiment examined whether the AB was related to both phonological and sight-word reading abilities, and whether the relationship was mediated by accuracy on a single-target rapid serial visual processing task (single-target accuracy). Undergraduate university students completed a battery of tests measuring reading ability, non-verbal intelligence, and rapid automatised naming, in addition to rapid serial visual presentation tasks in which they were required to identify either two (AB task) or one (single target task) target/s (outlined shapes: circle, square, diamond, cross, and triangle) in a stream of random-dot distractors. The duration of the AB was related to phonological reading (n=41, ß=-0.43): participants who exhibited longer ABs had poorer phonemic decoding skills. The AB was not related to sight-word reading. Single-target accuracy did not mediate the relationship between the AB and reading, but was significantly related to AB depth (non-linear fit, R(2)=.50): depth reflects the maximal cost in T2 reporting accuracy in the AB. The differential relationship between the AB and phonological versus sight-word reading implicates common resources used for phonemic decoding and target consolidation, which may be involved in cognitive control. The relationship between single-target accuracy and the AB is discussed in terms of cognitive preparation.

Radial nerve lacerations--the outcome of end-to-end repairs in penetrating trauma.

Due to its mostly motor content, repair of the radial nerve is considered to yield favourable results. This is despite the fact that there are limited studies looking at the outcomes of end-to-end repair secondary to sharp penetrating trauma. We retrospectively reviewed the outcome of a series of repaired level 2 and level 3 radial nerves following penetrating stab injuries. Twenty-seven cases with adequate follow-up were included. All the patients underwent direct end-to-end repair. We evaluated the motor recovery of the target muscles using the British Medical Research Council (MRC) grading system. Wrist extension recovered in 93% of cases at a mean of six months. Finger extension recovered in 74% and thumb extension in 52% of cases within the follow-up period. We conclude that end-to-end repair is possible in the majority of level 2 and level 3 radial nerve lacerations secondary to penetrating stab injuries. Acceptable results can be expected.

Synthesis and anchoring of antineoplastic ferrocene and phthalocyanine derivatives on water-soluble polymeric drug carriers derived from lysine and aspartic Acid.

The general synthetic strategy towards water-soluble biodegradable drug carriers and the properties that they must have are discussed. The syntheses of water-soluble biodegradable copolymers of lysine and aspartic acid as potential drug-delivering devices, having amine-functionalised side chains are then described. Covalent anchoring of carboxylic acid derivatives of the antineoplastic ferrocene and photodynamically active phthalocyanine moieties to the amine-containing drug carrier copolymers under mild coupling conditions has been achieved utilising the coupling reagent O-benzotriazolyl-N,N,N('),N(')-tetramethyluronium hexafluorophosphate to promote formation of the biodegradable amide bond. Even though the parent antineoplastic ferrocene and phthalocyanine derivatives are themselves insoluble in water at pH < 7, the new carrier-drug conjugates that were obtained are well water-soluble.

Synthesis and photochemical characterization of a zinc phthalocyanine-zinc porphyrin heterotrimer and heterononamer.

The synthesis of two phthalocyanine-porphyrin covalently linked heteromolecules are described. Intramolecular energy transfer is investigated and quantified in terms of the quantum yield of energy transfer and found to be highly effective in both molecules. The photophysical properties of both molecules are modified greatly by the presence of the porphyrin moieties on the phthalocyanine core.

Interferon-gamma microsatellite and rheumatoid arthritis.

Several non-HLA genes contribute to the susceptibility to rheumatoid arthritis (RA). A recent report noted an allele (126 bp [CA(13)]) of the interferon-gamma intron A microsatellite repeat strongly associated with both the occurrence and the severity of RA. We assessed this locus in an independent set of 128 controls and 93 prospectively recruited patients with early RA. The reported association could not be confirmed. This discrepancy might be due to technical problems, which could be avoided by the use of reference samples.

A baboon model for in vivo assessment of mucociliary lung clearance.

A suitable baboon model (Papio ursinus) for assessing inhibitory effects on mucociliary lung clearance was required. Clearance of various dimensions of nebulized particles (99mTc-labelled) was monitored with the animals (n = 6) under either ketamine or pentobarbitone anaesthesia. The best prospect of substantial and reproducible clearance in spite of the inhibition by the anaesthesia were obtained with pentobarbitone, and using nebulized radiolabelled particles of diameter range between 10 and 45 microns, thus avoiding trapping in the non-ciliary alveoli.

Prostaglandin E1 and papaverine: a comparative study on the ability to increase the penile bloodpool as measured by the 99mTc-penogram in the baboon model.

The evaluation of arterial blood supply and venous drainage of the penis is essential in assessing the impotent male. The vaso-active drugs prostaglandin E1 and papaverine, as intracavernous injections, cause penile erections in humans by influencing the arterial blood supply and venous drainage. These drugs were used in the normal baboon and in vascular compromised baboons using a 99mTc-penogram to quantify the vascular status of the penis. Ligation of the A. Iliaca Interna was performed to change the penile blood supply, thus compromising the vascular supply. It was observed that pre- and post-operatively, the increase in the penile bloodpool was more dramatic although not significantly so (P less than 0.05), but more variable after papaverine than with prostaglandin E1. The effect was even more enhanced (P less than 0.05) in the vascular compromised baboons so that the occurrence of priapism after papaverine can speculatively not be excluded. Also the more consistent vasoactive response after prostaglandin E1 seems to establish it as the superior intracavernous injectable agent.

Quantitative evaluation of the penile vascular status by means of the 99mTc-penogram in conjunction with either papaverine or prostaglandin E1 in the anaesthetised baboon model.

The evaluation of both the arterial blood supply and the venous drainage of the penis is essential in the assessment of the impotent male. The vasoactive drugs papaverine and prostaglandin E1, as intracavernous injections, cause penile erections by influencing arterial blood supply and venous drainage. These drugs were used in a baboon model together with a 99mTc-penogram to provide information on the vascular status of the penis. An increase in penile blood pool was observed, more dramatic and rapid after administration of papaverine. A quantitative assessment of the vascular status seems possible and will next be monitored in a vascular-compromised baboon for purposes of clinical application.

Preparation and biokinetic evaluation of various halogenated iminodiacetic acid-type compounds labeled with technetium-99m for hepatobiliary scintigraphy in the baboon (Papio ursinus) model.

In an evaluation of various 99mTc-labeled halogenated (F, Cl, Br, I) iminodiacetic acid (IDA) derivatives for hepatobiliary scintigraphy, it was found that, in the baboon model, none of these compounds performed as well as did disida. F-IDA was least effective, with the lowest biliary excretion and highest renal participation, but multihalogen substitution as in penta-F-IDA increased the biliary specificity and reduced urinary excretion to the extent that penta-F-IDA scored second to disida and even above I-IDA, with its high molecular weight. Surprising also was the relatively good performance of Cl-IDA compared to Br-IDA and I-IDA.

Investigation by scintigraphic methods of neutrophil kinetics under normal and septic shock conditions in the experimental baboon model.

The purpose of this study was the correlation of neutrophil kinetics with the pathogenic course of septic shock in the baboon model. Radioactively labelled neutrophils were traced in vivo in normal baboons (n = 6) and in Escherichia coli-infected baboons, which were reinjected with labelled autologous neutrophils either 2 h after the onset of the E. coli infusion (procedure A) (n = 3) or simultaneously with the infusion (procedure B) (n = 3). Cell isolation was done according to a method developed in this laboratory. The cells were labelled with tropolonate In 111, resuspended in 1-2 ml plasma and reinjected. One-minute images were taken every 5th min and then hourly for 4 h with a gamma camera and analysed with a data processor. Time-activity curves were obtained for neutrophil washout from the lungs and neutrophil accumulation in the liver and spleen. These curves were compared for normal baboons and for those treated according to procedures A and B. A significant retention of neutrophils in the lungs of baboons with E. coli-induced septic shock was noted as well as an abnormally slow rate of accumulation in the liver and spleen. It also seems that any lung injury which could be attributed to changes in neutrophil behaviour should be traced back to events during the early exposure of neutrophils to bacterial infection.

Investigation by scintigraphic methods of platelet kinetics under normal and septic shock conditions in the experimental baboon model.

This study concerned the correlation of platelet kinetics with the pathogenic course of septic shock and adult respiratory distress syndrome (ARDS) in the anesthetised baboon model. 111In-tropolonate platelets were traced in vivo in normal baboons (n = 7) and in Escherichia coli-infected baboons, which were reinjected with the labeled autologous platelets either 2 hr after the onset of the E. coli infusion (procedure A: n = 4) or simultaneously with the infusion (procedure B; n = 3). One minute images were taken hourly for 5 hr, using a gamma camera and data processor. Time-activity curves were obtained for platelet clearance from the blood and the lungs and for platelet accumulation in the liver and spleen. A significant retention of platelets in the lungs of baboons with E. coli-induced septic shock was noted, as well as an accelerated clearance from the circulation. Platelets were distributed mainly to the spleen after induction of bacteremia, later substantially moved to the liver, and even later moved back to the spleen.

Using the "integral spleen" method of radiorenogram analysis and a baboon model to compare the diagnostic usefulness of technetium-99m-diethylenetriamine pentaacetic acid to that of various technetium-99m-mercaptoacetyltriglycene formulations and iodine-123-hippuran.

In light of the high price of commercially available mercaptoacetyltriglycene (MAG3) it was decided to attempt a local MAG3-formation and to test this against diethylenetriamine pentaacetic acid (DTPA), 123I-Hippuran, and commercial MAG3 for diagnostic radiorenographic capabilities also in conjunction with furosemide and captopril. A baboon model (n = 6) was used, and the parameters evaluated were obtained by the "integral spleen" method of radiorenogram analysis. Although the images and parameters pointed to 123I-Hippuran and commercial MAG3 as the ideal renal scanning agents and to DTPA as the least so, with the local product an acceptable alternative, the differences were not significant enough to warrant either the purchase of the commercial product or the extensive development of the local product. Inexpensive 99mTc-DTPA in conjunction with modern computer techniques will probably supply most of the answers.

Left ventricular volume and function changes during beta-blockade and accompanying atrial pacing.

Radionuclide ventriculography was performed at rest and during transoesophageal pacing on nine anaesthetized baboons (Papio ursinus), alternatively with and without administration of a beta-blocker. Left ventricular volumes, cardiac output, and ejection fraction were determined at each heart rate. A gradual decrease in end-diastolic, end-systolic, and stroke volume followed with increasing heart rate, significantly more pronounced under beta-blockade. Cardiac output and ejection fraction showed no significant changes, although tendencies to increase were observed without beta-blockade. Comparisons of these parameter changes were drawn to those previously observed during the first 5 h of septic shock (E. coli). We conclude that the tachycardia present during this phase of shock is not the only contributory factor to cardiac function changes but that other depressant influences prevail as the added effect of the beta-blocker seems to suggest.

Changes in phase analysis patterns of radionuclide ventriculograms obtained from baboons during atrial pacing, septic shock, and induced myocardial infarction.

Changes in intraventricular phase delays, phase angle histograms, amplitude images, and electrocardiograms (ECG) were investigated during oesophageal pacing with and without beta-blockade, after induced myocardial infarction, and during septic shock in the anaesthetized baboon model. Unavoidable triggering from the pacemaker spike and to a lesser extent increased heart rate were responsible for parameter changes during pacing. Myocardial infarction changed contraction patterns, which did not always correlate with conduction changes from the ECG's. Cardiac volume changes during septic shock could be responsible for the abnormal trends in phase angle spread and electrocardiographic data.

Scintigraphic phase analysis of abnormal A-V conduction in a baboon.

During an interventional cardiac investigation on an anaesthetised baboon (Papio ursinus) the animal developed A-V block. Scintigraphic phase analysis leading to quantified intraventricular delays and histogram characteristics pointed to abnormalities which persisted even after A-V block was replaced by nodal tachycardia as was reflected by the electrocardiogram. This indicated towards an increased diagnostic sensitivity with the use of phase analytical methods.

Fourier phase parameters with possible diagnostic importance as obtained from the radionuclide ventriculograms of normal baboons with and without cardiac catheterization and under prolonged anaesthesia.

The possible diagnostic importance of parameters defined from radionuclide ventriculograms and Fourier phase analysis was investigated for data from normal baboons (Papio ursinus) under prolonged anaesthesia (7 hours). Of the 14 animals, 7 were studied using indwelling cardiac catheters. Phase angle differences between the electromechanical activation of the septum and left lateral wall (LLW), and again between the activation of the septum and the apex indicated no significant differences (p greater than 0.05) for the consecutive hourly values for both catheterized and non-catheterized baboons. Consequently, average values and their ranges (mean +/- 1 S.D.) were obtained for these parameters in each group, and they did not differ significantly between the two groups. As could be expected, the activation delays between the septum and LLW, and the septum and apex differed with the latter being significantly longer. The phase angle histogram parameters of atrial peak width, left ventricular plus right ventricular peak width, (LV + RV), LV-to-RV peak separation and LV-to-atrial peak separation were similarly analysed and found not to change significantly between hourly measurements or because of catheterization. Therefore mean normal values and ranges were also obtained for these parameters, possibly to serve as baselines in the diagnosis of subtle conduction pathology.

Evaluation of the clinical validity of the "integral spleen" method of renography analysis from parameter changes induced by pharmacological and surgical intervention.

A set of controlled experimental animal procedures involving pharmacological and surgical interventions was carried out to assess the clinical validity of the parameters calculated by the "integral spleen" method of renography analysis. There appeared to be a good correlation between the observed changes of these parameters and current pathophysiological information. In particular, the described method includes an original calculation of the filtration fraction without blood and urine sampling or a second tracer injection. This calculation was experimentally validated here.

A progressive radiorenographic (99mTc-DTPA) presentation of surgically induced renal vein hypertension in baboons.

A 99mTc-DTPA radiorenographic study, supported by excretory urography, blood chemistry and eventually histology was performed on 8 chacma baboons (Papio ursinus) after surgical induction of unilateral renal vein hypertension. Frequent sequential repeat renograms during 6 post-operative months detected fluctuating renal behaviour but did not reveal typical course of the disease. Neither did any one of the radiorenographic parameters (TP, T1/2, FF, relative clearances and perfusion) prove to be more sensitive than the others in detecting abnormalities. Initial microscopic or macroscopic haematuria and proteinuria in general eventually cleared up. Light microscopy demonstrated only mild abnormalities. The effects of venous occlusion of the kidney and the prognosis seemed to be variable as was reflected by radiorenography.