Dynamic CT of solitary pulmonary nodules: comparison of contrast medium distribution characteristic of malignant and benign lesions.

BACKGROUND: To prospectively assess the role of the dynamic contrast-enhanced CT enhancement characteristics in distinguishing malignant form of benign solitary pulmonary nodules. METHODS: The study included 87 patients (59 men, 28 women; median age, 59 years) with 87 solitary pulmonary nodules. In all cases, dynamic CT images were obtained before and 20, 30, 45, 60, 75, 90, 120 s, 3, 5, 9, 12, 15 and 20 min after injection of contrast medium. Peak enhancement attenuation value, net enhancement attenuation value, the slope of enhancement, enhancement ratio, outflow of contrast medium (washout), washout ratio and the slope of washout ratio were assessed. Statistical analyses were performed with the Mann-Whitney test, χ(2) test, and receiver-operating characteristic curves. RESULTS: There were 52 malignant and 35 benign nodules. There were no significant differences in net enhancement value, enhancement ratio and the slope of enhancement ratio between malignant and benign nodules (P > 0.05). Malignant nodules showed smaller outflow of contrast medium than did benign nodules. With 12.4HU or lower washout as a cutoff value, the sensitivity and specificity for malignancy were 52.5 and 65.0 %, respectively. With 18.9 % or lower washout ratio as a cutoff value, sensitivity and specificity for malignancy were 60.0 and 75.0 %, respectively. With 0.0180 %/s or lower slope of washout ratio as a cutoff value, sensitivity and specificity for malignancy were 60.0 and 80.0 %, respectively. CONCLUSIONS: Dynamic contrast-enhanced CT is helpful in differentiating malignant from benign solitary pulmonary nodules. Smaller washout of contrast enhancement is a predictor that a lesion is malignant.

Multidetector CT features of pulmonary focal ground-glass opacity: differences between benign and malignant.

OBJECTIVE: To evaluate different features between benign and malignant pulmonary focal ground-glass opacity (fGGO) on multidetector CT (MDCT). METHODS: 82 pathologically or clinically confirmed fGGOs were retrospectively analysed with regard to demographic data, lesion size and location, attenuation value and MDCT features including shape, margin, interface, internal characteristics and adjacent structure. Differences between benign and malignant fGGOs were analysed using a χ(2) test, Fisher's exact test or Mann-Whitney U-test. Morphological characteristics were analysed by binary logistic regression analysis to estimate the likelihood of malignancy. RESULTS: There were 21 benign and 61 malignant lesions. No statistical differences were found between benign and malignant fGGOs in terms of demographic data, size, location and attenuation value. The frequency of lobulation (p=0.000), spiculation (p=0.008), spine-like process (p=0.004), well-defined but coarse interface (p=0.000), bronchus cut-off (p=0.003), other air-containing space (p=0.000), pleural indentation (p=0.000) and vascular convergence (p=0.006) was significantly higher in malignant fGGOs than that in benign fGGOs. Binary logistic regression analysis showed that lobulation, interface and pleural indentation were important indicators for malignant diagnosis of fGGO, with the corresponding odds ratios of 8.122, 3.139 and 9.076, respectively. In addition, a well-defined but coarse interface was the most important indicator of malignancy among all interface types. With all three important indicators considered, the diagnostic sensitivity, specificity and accuracy were 93.4%, 66.7% and 86.6%, respectively. CONCLUSION: An fGGO with lobulation, a well-defined but coarse interface and pleural indentation gives a greater than average likelihood of being malignant.

Treatment of malignant digestive tract obstruction by combined intraluminal stent installation and intra-arterial drug infusion.

AIM: To study the palliative treatment of malignant obstruction of digestive tract with placement of intraluminal stent combined with intra-arterial infusion of chemotherapeutic drugs. METHODS: A total of 281 cases of digestive tract malignant obstruction were given per oral (esophagus, stomach, duodenum and jejunum), per anal (colon and rectum) and percutaneous transhepatic (biliary) installation of metallic stent. Among them, 203 cases received drug infusion by cannulation of tumor supplying artery with Seldinger's technique. RESULTS: Altogether 350 stents were installed in 281 cases, obstructive symptoms were relieved or ameliorated after installation. Occurrence of restenotic obstruction was 8-43 weeks among those with intra-arterial drug infusion, which was later than 4-26 weeks in the group with only stent installation. The average survival time of the former group was 43 (3-105) weeks, which was significantly longer than 13 (3-24) weeks of the latter group. CONCLUSION: Intraluminal placement of stent combined with intra-arterial infusion chemotherapy is one of the effective palliative therapies for malignant obstruction of the digestive tract with symptomatic as well as etiological treatment.

[Effect of DGAVP and Org2766 on intracellular free Ca2+ concentration in dissociated brain cells].

Intracellular free calcium concentration ([Ca2+]i) was measured with Fura-2 in freshly dissociated brain cells isolated from newborn (1-2 day) mouse pups using AR-CM-MIC cation measurement system, and the effects of DGAVP and Org2766 on the changes in [Ca2+]i induced by the protein synthesis inhibitor anisomycin (ANI) were studied. The results indicate that anisomycin caused dose-dependent increases in [Ca2+]i; and DGAVP itself showed no significant effect on [Ca2+]i, but an appropriate dose of DGAVP antagonized the increases induced by the selective dose-range of ANI, suggesting that the antagonism of ANI-induced inhibition of protein synthesis by DGAVP was likely achieved by preventing ANI from increasing [Ca2+]i, but this mechanism did not apply to the other neuropeptide Org2766. Therefore, we suppose that the mechanism of the two neuropeptides are different in terms of their effect on intracellular free calcium concentration.

[Correlation between synaptic protein phosphorylation in hippocampi and shuttle box avoidance behavior].

The present investigation was undertaken to detect whether protein phosphorylation levels of hippocampal synaptosomes in mice trained on shuttle box avoidance task would show some changes. The synaptosomes were prepared at different times after the conclusion of training and labelled with gamma-32P-ATP for in vitro determination. The results are as follows: (1) No significant differences were found in the phosphorylation of synaptosomal proteins in different brain areas in normal mice before training. (2) Immediately after the conclusion of shuttle box avoidance task there appears a correlation between protein phosphorylation levels in hippocampal synaptosomes and the degree of success of training. (3) 24 h after the completion of training the above relationship is more significant, and protein phosphorylation levels of right hippocampus in Good Score Group is markedly higher than that of left one, but in the Inferior Score Group, the left-right difference is reverse. The formation of such asymmetry in protein phosphorylation in hippocampi is unknown. These data indicate that the synaptic protein phosphorylation in hippocampi might be a molecular mechanism of acquisition.

Neuropeptides related to neurohypophyseal hormones interfere with apomorphine-induced behavioral changes.

The interaction between peptides related to neurohypophyseal hormones and brain dopaminergic systems was studied by investigating in rats the effect of these peptides on behavioral changes induced by graded doses of the specific dopamine agonist apomorphine. Low doses of this drug induce hypoactivity of the animals, while higher doses result in hyperactivity and stereotyped sniffing. Desglycinamide9[Arg8]vasopressin (DG-AVP), prolyl-leucyl-glycinamide (PLG) and oxytocin did not interfere with the behavioral responses induced by the higher doses of apomorphine. Peptide treatment made the rats more sensitive to apomorphine with respect to the drug induced hypoactivity. PLG and especially DG-AVP were more effective than oxytocin. It is concluded that these peptides may have a selective action on distinct dopaminergic receptor systems in the brain, that are presumably located presynaptically in the nucleus accumbens area.