Brain metastasis in lung cancer

FDG-PET/CT is increasingly used in staging of lung cancer as single „one stop shop” method. Aim, patients, methods: We prospectively included 104 neurological asymptomatic patients (65 years, 26% women) with primary diagnosis of lung cancer. In all patients PET/CT including cerebral imaging and cerebral MRI were performed. Results: Diagnosis of brain metastases (BM) was made by PET/CT in 8 patients only (7.7%), by MRI in 22 (21.2%). In 80 patients both PET/CT and MRI showed no BM. In 6 patients (5.8%) BM were detectable on PET/CT as well as on MRI. Exclusive diagnosis of BM by MRI with negative finding on PET/CT was present in 16 patients (15.4%). 2 patients (1.9%) had findings typical for BM on PET/CT but were negative on MRI. With MRI overall 100 BM were detected, with PET/CT only 17 BM (p < 0.01). For the diagnosis of BM PET/CT showed a sensitivity of 27.3%, specificity of 97.6%, positive predictive value of 75% and negative predictive value of 83.3%. BM diameter on PET/CT and MRI were consistent in 43%, in 57% BM were measured larger on MRI. Discussion: Compared to the gold standard of MRI for cerebral staging a considerable number of patients are falsely diagnosed as free from BM by PET/CT. MRI is more accurate than PET/CT for detecting multiple and smaller BM. Conclusion: In patients with a curative option MRI should be performed additionally to PET/CT for definitive exclusion of brain metastases.

1H-NMR analysis of trimethylamine in urine for the diagnosis of fish-odour syndrome

This paper reports the use of proton NMR spectroscopy for the analysis of trimethylamine in the urine of a patient with trimethylaminuria. Analysis of this compound was also performed for other members of his family. Qualitative and quantitative determination of trimethylamine and trimethylamine-N-oxide was simultaneously performed on untreated urine within a few minutes. The application of the method is discussed.

Glycoproteins and lectins in cell adhesion and cell recognition processes

The discovery of endogenous lectins having specific and high affinity for the carbohydrate portions of glycoproteins has opened up new directions in the field of cell adhesion and cell recognition. Two endogenous lectins, termed as CSL and R1, initially isolated from the rat cerebellum and having a wide distribution in mammalian tissues, have been shown to participate in essential mechanisms of cell adhesion. The membrane-bound lectin R1 seems to be involved in transient recognition between neuronal cells, followed by elimination of the glycoprotein ligands at the surface of the recognized cell. In contrast, CSL is a molecule involved in adhesion between various normal or transformed cells since it participates in the formation of tight junctions. The glycoprotein ligands recognized with higher affinity by these two lectins seem to possess a special structure which defines a sub-class of oncofetal HNK-1 glycans. The over-expression of the glycoprotein ligands of these lectins in most transformed cells provides new tools for understanding the underlying mechanism of malignant transformation as well as the generation of signals through cell adhesion.

Differential binding of lectins IL-2 and CSL to candida albicans and cancer cells

The demonstration that interleukin 2 (IL-2) is a lectin specific for oligomannosides allows to understand a new function for this cytokine: as a bifunctional molecule when bound to its receptor ss, IL-2 associates the latter which the CD3/TCR complex, interacting with oligosaccharides of CD3 through its carbohydrate-recognition domain (Zanetta et al. , 1996, Biochem. J., 318, 49-53). This induces the tyrosine phosphorylation of the IL-2R beta by ++p56(lck) , the first step of the IL-2-dependent signaling. Since this specific association is disrupted in vitro by oligomannosides with five and six mannose residues, we made the hypothesis that pathogenic cells or microorganisms could bind IL-2, consequently disturbing the IL-2-dependent response. This study shows that the pathogenic yeast Candida albicans (in contrast with nonpathogenic yeasts) binds high amounts of IL-2 as did cancer cells. In contrast with cancer cells, yeasts do not bind the Man6GlcNAc2-specific lectin CSL, an endogenous "amplifier of activation signals" (Zanetta et al. , 1995, Biochem. J., 311, 629-636).

Regulatory T Cells Promote Natural Killer Cell Education in Mixed Chimeras

Therapeutic administration of regulatory T cells (Tregs) leads to engraftment of conventional doses of allogeneic bone marrow (BM) in nonirradiated recipient mice conditioned with costimulation blockade and mammalian target of rapamycin inhibition. The mode of action responsible for this Treg effect is poorly understood but may encompass the control of costimulation blockade-resistant natural killer (NK) cells. We show that transient NK cell depletion at the time of BM transplantation led to BM engraftment and persistent chimerism without Treg transfer but failed to induce skin graft tolerance. In contrast, the permanent absence of anti-donor NK reactivity in mice grafted with F1 BM was associated with both chimerism and tolerance comparable to Treg therapy, implying that NK cell tolerization is a critical mechanism of Treg therapy. Indeed, NK cells of Treg-treated BM recipients reshaped their receptor repertoire in the presence of donor MHC in a manner suggesting attenuated donor reactivity. These results indicate that adoptively transferred Tregs prevent BM rejection, at least in part, by suppressing NK cells and promote tolerance by regulating the appearance of NK cells expressing activating receptors to donor class I MHC.

Diagnosis of a case of acute chloroquine poisoning using 1H NMR spectroscopy: characterisation of drug metabolites in urine

Analysis of biological fluids by proton nuclear magnetic resonance spectroscopy (1H NMR) is a promising tool in clinical biology. We have used this method for a rapid toxicological screening in the case of a suicide attempt. A urine sample was analysed at 300 and 600 MHz by 1D and 2D sequences (J-resolved and TOCSY) in a short experimental time. Quantification was realized by peak integration of the 1D spectrum. The results showed the presence of chloroquine and its major metabolite monodesethylchloroquine at concentrations of 462 and 140 mg/L, respectively. Ethanol was also detected in the spectrum. It can be concluded that 1H NMR provides many advantages as a tool for clinical diagnosis in a case of acute intoxication.

Salicylate poisoning: two-dimensional J-resolved NMR urinalysis

Identification of a case of acute salicylate intoxication using 300 MHz 1H NMR spectroscopy of a urine sample is reported. It has been achieved by using a combination of a one-dimensional experiment with water presaturation and a two-dimensional homonuclear J-resolved experiment. By these means, lysine and the three major metabolites of acetylsalicylic acid have been assigned in the crude urine. The results are compared with those obtained at 600 MHz and with classical biochemical methods. The use of this method for routine diagnosis in biological analysis is discussed.

Virtual single source CT using dual source acquisition: Clinical applicability in run-off CT-angiography for intra-individual comparison of different scan protocols

PURPOSE

Virtual single source computed tomography (VSS-CT) acquisition on a dual source CT (DSCT) has been demonstrated to allow for dose-neutral intra-individual comparison of three acquisition protocols at different radiation dose levels (RDL) within one acquisition in a phantom. The purpose of this study was twofold: first to evaluate the applicability of VSS-CT in patients and second to optimize the task-dependent trade-off between radiation dose and image quality of lower extremity CT angiography (run-off CTA).

MATERIAL AND METHODS

In this IRB-approved prospective study 52 patients underwent run-off CTA between 06/2012 and 06/2013. VSS-CT acquisition was conducted using a first generation DSCT applying equal X-ray tube settings (120 kVp), collimation (2 × 32 × 0.6 mm), and slice thickness (1.0 mm) but different effective tube current-time products (tube A: 80 mAs, tube B: 40 mAs). Three different image datasets representing three different radiation dose levels (RDL40, RDL80, RDL120) were reconstructed using a soft kernel from the raw data of tube B, tube A or both tubes combined. Dose length products (DLP) of each raw data set were documented. Quantitative image quality (IQ) was assessed for five anatomical levels using image noise and contrast-to-noise ratio (CNR). To investigate dose efficiency of each acquisition, the dose-weighted CNR (CNRD) was determined. Qualitative IQ was evaluated by two blinded readers in consensus using a 5-point Likert scale and compared with a Friedman- and posthoc Wilcoxon test.

RESULTS

Mean DLP was 200 ± 40, 400 ± 90 and 600 ± 130 mGy·cm for the RDL40, RDL80 and RDL120, respectively. Image noise and CNR were best for RDL120 and decreased significantly for RDL80 and RDL40, independent of the anatomic level (p < 0.001). CNRD showed no significant differences at the abdominal and pelvic level between the investigated radiation dose levels. However, for thigh to foot level a significant increase of CNRD was noted between RDL120, RDL80 and RDL40. Significant differences of qualitative IQ were observed between RDL120 and RDL40 from the abdominal to the foot level, whereas no difference was seen for the other dose levels.

CONCLUSION

Radiation dose splitting with VSS-CT can be applied to run-off CTA facilitating intra-individual comparison of different acquisition protocols without additional radiation exposure. Furthermore, a radiation dose reduction potential for run-off CTA of approximately 1/3 as compared to the acquisition protocol recommended by the manufacturer could be identified in this study.

Malignant cells have increased levels of common glycoprotein ligands of the endogenous cerebellar soluble lectin CSL

The glycoprotein composition of various transformed cells or malignant tumors was analyzed and compared to their respective non-malignant control cells or tissues of several species, including man, using an endogenous carbohydrate-binding protein, the cerebellar soluble lectin CSL (Zanetta et al., J. Neurochem. 49, 1250-1257 (1987). A large variety of transformed cells contain a much higher number and larger quantity of glycoprotein ligands of CSL than the control cells or normal tissues. The glycoprotein profiles were, in most cases, independent of the nature of the cell transformation of the degree of differentiation, of the tissue and species. Thus, it is suggested that many transformed cells have, as a common anomaly, the increased synthesis of the special type of glycan recognized by CSL, expressed on the same polypeptide chains.

Carbohydrates and soluble lectins in the regulation of cell adhesion and proliferation

There is a large body of suggestions that complex carbohydrates play a role in the regulation of cell adhesion and cell proliferation. Many reports have emphasized that proteoglycans, glycoproteins or glycolipids are participating to cell adhesion mechanisms. The use of polyvalent anti-carbohydrate antibodies and plant lectins as well as the use of glycosylation inhibitors suggested that cell proliferation can be modulated by surface carbohydrates. The dating experiment of Burger and Noonan (1970) showing restoration of contact inhibition of malignant cells by monovalent concanavalin A was a determining experiment. However, in the latter as in the others, no precise mechanism was demonstrated how carbohydrates can be involved in adhesion and proliferation. New insights were opened with the discovery of vertebrate membrane-bound and soluble lectins. The latter generally display agglutinating activities in in vitro systems, suggesting that they were potential cell adhesion molecules, by forming bridges between cell surface carbohydrates. These polyvalent molecules may be also considered as clustering agents for their cell surface ligands, consequently generating signals for cell proliferation and/or differentiation.