The effects of inversion and eye displacements of familiar and unknown faces on early and late-stage ERPs.

OBJECTIVES: The objective of this study is to examine whether configural alterations of faces affect early or late processing stages as a function of their familiarity and their level of representation in memory. We then sought to verify whether the structural encoding stage is susceptible to top-down influences. METHODS: Electrophysiologic and behavioral studies were undertaken, during which unknown and familiar faces were presented upright or upside-down with or without feature alterations. The subjects were asked to determine whether the faces were familiar or not. RESULTS: N170 and N360 amplitudes were larger for familiar faces as well as altered ones. A higher degree of familiarity decreased reaction times (RTs) and N360 latencies, but increased N170 latencies, whereas face alterations increased RTs and latencies of both components examined. However, familiarity interacted with altered face configurations only for RTs and the N170. SIGNIFICANCE: In the perceptual stage, familiar faces seem to develop a more elaborate type of processing because of top-down influences linked to the robust nature of their representations in memory. The more elaborate type of processing for familiar faces has advantageous consequences for the following steps of information processing, by facilitating access to structural representations in memory (N360) as well as the final step reflected by RTs. The fact that configural alterations cause different effects for familiar as opposed to unfamiliar faces indicate that these stimuli are processed in a qualitatively different manner and solicit different representations in memory.     

Cumulative renal tubular damage associated with cisplatin nephrotoxicity

Summary We assessed the acute and chronic effect of multiple courses of cisplatin therapy on renal tubules by monitoring the urinary excretion of alanine aminopeptidase, N-acetyl--D-glucosaminidase, and total protein. Urine specimens were obtained before and after doses of cisplatin (90 mg/m²) given to 12 patients. Each dose of cisplatin induced transient increases in enzyme excretion, followed by proteinuria 3–5 days later. Transient enzymuria after the last cisplatin dose was significantly greater than that after the first dose. Moreover, persistent increases in urinary N-acetyl--D-glucosaminidase and serum creatinine concentrations over pretherapy levels indicated chronic renal tubular damage. Our findings disclosed striking differences between patients in susceptibility to progressive nephrotoxicity.Supported by Biomedical Research Support Grant RR05584 (MPG), Cancer Center Support Grant (CORE) CA-21765, Chilhood Solid Tumor Program Project Grant CA-23099 and the American Lebanese Syrian Associated Charities (ALSAC)     

Radioiodinated derivatives of beta adrenoceptor blockers for myocardial imaging.

Four new beta-adrenoceptor blocking agents carrying tyramine as the amino moiety were synthesized and the distribution of their I-125-tagged derivatives evaluated in rats. This distribution was compared with the distribution of various agonists and antagonists labeled with H-3 and C-14, and with the in vitro binding affinity of the new derivatives. A radioiodinated derivative of a cardioselective blocker, alprenolol, showed poor blood clearance and no cardiac selectivity. A derivative of another cardioselective blocker, practolol, showed a promising heart-to-blood ratio (ca. 19) and cardioselectivity with a heart-to-lung ratio of ca. 2. Two additional practolol analogs showed no improvement over the practolol derivative; because of the increased lipophilicity of these derivatives, blood clearance and cardioselectivity were diminished. An inverse correlation is suggested between the dissociation constant for the beta adrenoceptor in the lung and the heart-to-blood and heart-to-lung values. We conclude that polarity plays an important role in the blood clearance and cardioselectivity of these beta-adrenoceptor derivatives.     

Use of plasma products with whole blood and packed RBCs.

During the past five years, there has been a sharp increase in the use of packed RBCs (PRBCs) and plasma products, whereas whole blood (WB) transfusions have steadily decreased. In order to determine whether plasma and its derivatives were being used to "reconstitute" whole blood from PRBCs, we performed a retrospective evaluation of all transfusion episodes in ten representative regional hospitals during a five-month period. Our results indicate that PRBCs were transfused 2.5 times more frequently than WB. Plasma products were administered with PRBCs less often than with WB: 14% of all PRBCs vs 24% of all WB units tranfused. The likelihood of a patient receiving plasma was found to correlate with the total amount of blood transfused and the frequency of transfusion. This study provides evidence that, at most, only a small percentage of PRBCs are given in conjunction with plasma as "reconstituted" WB.     

Noninvasive detection of multivessel disease after myocardial infarction by exercise radionuclide ventriculography

The ability of exercise radionuclide ventriculography to detect multivessel coronary artery disease in patients who survived a single myocardial infarction was assessed. Seventy-four patients who had had myocardial infarction at least 8 weeks earlier underwent cardiac catheterization and exercise radionuclide ventriculography. Thirty-eight patients had had an inferior infarction: 25 with multivessel disease and 13 with single vessel disease of the right coronary artery. Thirty-six patients had had an anterior infarction: 26 with multivessel disease and 10 with single vessel disease of the left anterior descending coronary artery.

Among patients with anterior infarction there was no significant difference between patients with single vessel disease and patients with multivessel disease with regard to resting ejection fraction, exercise ejection fraction, and the mean change from rest to exercise. Patients with single vessel disease had a decrease in ejection fraction from rest to exercise of 2.2 ± 2.7% units (mean) ± standard error [SE]), compared with a decrease of 5.4 ±1.3% units in those with multivessel disease (p = not significant [NS]). Seventeen of 26 (65%) patients with multivessel disease and 6 of 10 (60%) with single vessel disease had a decrease in ejection fraction of at least 5 percentage units (p = NS).

In patients with inferior infarction there was no difference in the mean resting ejection fraction in those with single vessel disease (53 ± 2%) compared with those with multivessel disease (50 ±2%); however, the mean exercise ejection fraction in patients with single vessel disease (57 ± 3%) was significantly higher (p < 0.005) than that in patients with multivessel disease (45 ± 2%). Sixteen of the 25 patients with multivessel disease (64%) but only 1 patient with single vessel disease (7.7%) had a decrease in ejection fraction of at least 5 percentage units (p < 0.001).

A new wall motion abnormality developed in 8 patients with anterior infarction and 11 with inferior infarction with multivessel disease and none with single vessel disease. The sensitivity and specificity in predicting multivessel disease using the criteria of the development of a new wall motion abnormality or a decrease in ejection fraction with exercise of at least 5 percentage units were 80 and 92% for the patients with inferior infarction, but only 69 and 40% for the patients with anterior infarction.

These results suggest that exercise radionuclide angiography can be used to discriminate between single and multivessel disease after inferior myocardial infarction. For patients with anterior infarction, only a new abnormality in wall motion accurately predicts multivessel disease, but this occurred in only one third of such patients.     

TLR2 engagement on CD4+ T cells enhances effector functions and protective responses to Mycobacterium tuberculosis

We have previously demonstrated that mycobacterial lipoproteins engage TLR2 on human CD4⁺ T cells and upregulate TCR‐triggered IFN‐γ secretion and cell proliferation in vitro. Here we examined the role of CD4⁺ T‐cell‐expressed TLR2 in Mycobacterium tuberculosis (MTB) Ag‐specific T‐cell priming and in protection against MTB infection in vivo. Like their human counterparts, mouse CD4⁺ T cells express TLR2 and respond to TLR2 costimulation in vitro. This Th1‐like response was observed in the context of both polyclonal and Ag‐specific TCR stimulation. To evaluate the role of T‐cell TLR2 in priming of CD4⁺ T cells in vivo, naive MTB Ag85B‐specific TCR transgenic CD4⁺ T cells (P25 TCR‐Tg) were adoptively transferred into Tlr2^?/? recipient C57BL/6 mice that were then immunized with Ag85B and with or without TLR2 ligand Pam₃Cys‐SKKKK. TLR2 engagement during priming resulted in increased numbers of IFN‐γ‐secreting P25 TCR‐Tg T cells 1 week after immunization. P25 TCR‐Tg T cells stimulated in vitro via TCR and TLR2 conferred more protection than T cells stimulated via TCR alone when adoptively transferred before MTB infection. Our findings indicate that TLR2 engagement on CD4⁺ T cells increases MTB Ag‐specific responses and may contribute to protection against MTB infection.     

Positron emission tomography in the diagnosis and management of giant cell arteritis

We describe a 58-year-old woman who presented with new onset of temporal headaches and a nondiagnostic temporal artery biopsy in whom positron emission tomography led to the diagnosis of giant cell arteritis. After treatment with corticosteroids the patient's symptoms resolved. A repeat (18)FDG PET-CT scan illustrated virtually complete resolution of the abnormal (18)FDG uptake in the arterial wall.