Peripheral arterial disease: comparison of color duplex US and contrast-enhanced MR angiography for diagnosis

PURPOSE: To prospectively compare the diagnostic accuracies of color duplex ultrasonography (US) and contrast material-enhanced magnetic resonance (MR) angiography and to assess interobserver agreement regarding contrast-enhanced MR angiographic findings in patients suspected of having peripheral arterial disease (PAD). MATERIALS AND METHODS: The institutional review board approved the study, and all patients provided signed informed consent. Two hundred ninety-five patients referred for diagnostic and preinterventional work-up of PAD with duplex US also underwent gadolinium-enhanced MR angiography. Data sets were reviewed for presence or absence of 50% or greater luminal reduction, which indicated hemodynamically significant stenosis, and to determine interobserver agreement. At duplex US, a peak systolic velocity ratio of 2.5 or greater indicated significant stenosis. Primary outcome measures were differences between duplex US and contrast-enhanced MR angiography in sensitivity and specificity for detection of significant stenosis, as assessed with the McNemar test, and interobserver agreement between the two contrast-enhanced MR angiogram readings, expressed as quadratic weighted kappa values. Intraarterial digital subtraction angiography (DSA) was the reference standard. RESULTS: Two hundred forty-nine patients had at least one hemodynamically significant stenotic lesion at contrast-enhanced MR angiography, duplex US, or both examinations. One hundred fifty-two patients underwent intraarterial DSA. The quadratic weighted kappa for agreement regarding the presence of 50% or greater stenosis at contrast-enhanced MR angiography was 0.89 (95% confidence interval [CI]: 0.87, 0.91). Sensitivity of duplex US was 76% (95% CI: 69%, 82%); specificity, 93% (95% CI: 91%, 95%); and accuracy, 89%. Sensitivity and specificity of contrast-enhanced MR angiography were 84% (95% CI: 78%, 89%) and 97% (95% CI: 95%, 98%), respectively; accuracy was 94%. Sensitivity (P = .002) and specificity (P = .03) of contrast-enhanced MR angiography were significantly higher. CONCLUSION: Results of this prospective comparison between contrast-enhanced MR angiography and duplex US provide evidence that contrast-enhanced MR angiography is more sensitive and specific for diagnosis and preinterventional work-up of PAD.     

Facilitation of memory by contextual cues in patients with diencephalic or medial temporal lobe dysfunction

Item-context binding is crucial for successful episodic memory formation, and binding deficits have been suggested to underlie episodic-memory deficits. Here, our research investigated the facilitation of cued recall and recognition memory by contextual cues in 20 patients with Korsakoff's amnesia, 20 unilateral medial-temporal lobectomy (MTL) patients and 36 healthy controls. In a computerized task participants had to learn 40 nouns that were randomly combined with a photograph of an everyday scene. Korsakoff patients showed a general memory deficit in both the cued recall and the recognition condition. A less severe memory impairment was found in the patients with medial-temporal lobectomy. Contextual cues facilitated cued recall to an equal extent in unilateral temporal lobectomy patients and healthy controls. However, no facilitation was observed in Korsakoff patients, suggesting an impairment in item-context binding during cued recall tasks. In contrast to the presumed exclusive dependency of recognition memory on item information, all groups equally profited from the contextual cues in recognition tasks. Our findings show that unilateral lesions as with MTL result in normal binding of context and item information, while bilateral dysfunction of the hippocampal-diencephalic system results in impaired context and item binding.     

The effectiveness of the hair-restorer "Dabao" in males with alopecia androgenetica. A clinical experiment

In a randomized, double-blind trial the effectiveness of 6 months' use of a Chinese herb extract (Dabao) as a hair-restorer was studied on 396 males with alopecia androgenetica. The effect was evaluated by nonvellus hair counts, participants' opinions and a panel's judgement of a photo-report. Twenty-three participants withdrew prematurely from the study. In both the Dabao and placebo groups an increase in the amount of hair was observed; 133 and 109 hairs on a 5 cm2 marked area, a difference of 24 hairs (p = 0.03, one-sided). Participants as well as the panel reached a similar conclusion. Regarding cosmetic effect, 42% of the participants in the Dabao group and 37% in the placebo group reported positive results. The average panel score for the cosmetic result on a scale of -10 to +10 was 0.46 in the Dabao and 0.21 in the placebo group, a difference of 0.24 (p = 0.04, one-sided). It appears from our study that, although the cosmetic effect over 6 months is modest, Dabao does have a certain effect on the growth of nonvellus hair.     

Identification of potential prognostic markers for vulvar cancer using immunohistochemical staining of tissue microarrays.

The aim of this study is to determine immunohistochemical markers with prognostic significance for disease-specific survival in patients with squamous cell cancer of the vulva. The study material consisted of slides and paraffin blocks of 50 vulvectomy specimens. A tissue microarray was constructed and stained with 16 antibodies. The impact of lymph node metastases, size of tumor, vascular space involvement, and the marker expression on disease-specific survival was calculated. In univariate analysis lymph node metastases, tumor size more than 4 cm, vascular space involvement, strong cyclooxygenase 2 expression, and absent Caspase 3 expression were significantly associated with disease-specific survival. In a multivariate analysis, poor disease-specific survival is independently associated with absent Caspase 3 expression (hazard ratio, 0.2; 95% confidence interval, 0.04-0.97; P = 0.045). Five-year survival was 86% in patients with tumors positive for Caspase 3 (n = 20) and drops to 64% in patients with Caspase 3-negative tumors (n = 30). In this test set, cyclooxygenase 2 and Caspase 3 seem to be immunohistochemical markers with prognostic significance for vulva cancer. The results have to be validated.     

Defects in nuclear structure and function promote dilated cardiomyopathy in lamin A/C-deficient mice

Laminopathies are a group of disorders caused by mutations in the LMNA gene that encodes the nuclear lamina proteins, lamin A and lamin C; their pathophysiological basis is unknown. We report that lamin A/C-deficient (Lmna(-/-)) mice develop rapidly progressive dilated cardiomyopathy (DCM) characterized by left ventricular (LV) dilation and reduced systolic contraction. Isolated Lmna(-/-) myocytes show reduced shortening with normal baseline and peak amplitude of Ca(2+) transients. Lmna(-/-) LV myocyte nuclei have marked alterations of shape and size with central displacement and fragmentation of heterochromatin; these changes are present but less severe in left atrial nuclei. Electron microscopy of Lmna(-/-) cardiomyocytes shows disorganization and detachment of desmin filaments from the nuclear surface with progressive disruption of the cytoskeletal desmin network. Alterations in nuclear architecture are associated with defective nuclear function evidenced by decreased SREBP1 import, reduced PPARgamma expression, and a lack of hypertrophic gene activation. These findings suggest a model in which the primary pathophysiological mechanism in Lmna(-/-) mice is defective force transmission resulting from disruption of lamin interactions with the muscle-specific desmin network and loss of cytoskeletal tension. Despite severe DCM, defects in nuclear function prevent Lmna(-/-) cardiomyocytes from developing compensatory hypertrophy and accelerate disease progression.     

Ignoring theory and misinterpreting evidence: the false belief in fear appeals

Use of fear appeals assumes that when people are emotionally confronted with the negative effects of their behaviour they will change that behaviour. That reasoning is simple and intuitive, but only true under specific, rare circumstances. Risk perception theories predict that if people will experience a threat, they want to counter that threat. However, how they do so is determined by their coping efficacy level: if efficacy is high, they may change their behaviour in the suggested direction; if efficacy is low, they react defensively. Research on fear appeals should be methodologically sound, comparing a threatening to a non-threatening intervention under high and low efficacy levels, random assignment and measuring behaviour as outcome. We critically review extant empirical evidence and conclude that it does not support positive effects of fear appeals. Nonetheless, their use persists and is even promoted by health psychology researchers, causing scientific insights to be ignored or misinterpreted.