Early prediction of response by ¹8F-FDG PET/CT during preoperative therapy in locally advanced rectal cancer: a systematic review.

AIM: To assess the predictive value of fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) in early assessing response during neo-adjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer. MATERIALS AND METHODS: A systematic review was performed by search of MEDLINE Library for the following terms: "rectal carcinoma OR rectal cancer", "predictive OR prediction OR response assessment OR response OR assessment", "early OR ad interim", "therapy", "FDG OR (18)F-FDG", "PET OR PET/CT". Articles performed by the use of stand-alone PET scanners were excluded. RESULTS: 10 studies met the inclusion criteria, including 302 patients. PET/CT demonstrated a good early predictive value in the global cohort (mean sensitivity = 79%; mean specificity = 78%). SUV and its percentage decrease (response index = RI) were calculated in all studies. A higher accuracy was demonstrated for RI (mean sensitivity = 82%; pooled specificity = 85%) with a mean cut-off of 42%. The mean time point to perform PET scan during CRT resulted to be at 1.85 weeks. Some PET parameters resulted to be both predictive and not statistical predictive of response, maybe due to the small population and few studies bias. CONCLUSION: PET showed high accuracy in early prediction response during preoperative CRT, increased with the use of RI as parameter. In the era of tailored treatment, the precocious assessment of non-responder patients allows modification of the subsequent strategy especially the timing and the type of surgical approach.

(99m)Tc-DTPA scintigraphy assesses the absence of glomerular filtration rate impairment of Aliskiren in high-risk hypertensive subjects. A 12-month follow-up study.

AIM: Glomerular filtration rate (GFR) is commonly calculated using the modification of diet in renal disease (MDRD) and Cockroft-Gault (CG) formulas and recently by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) algorithm and not directly measured, so that the real impact of antihypertensive therapy on GFR could not be well defined. In this study, the effect of Aliskiren on the GFR measured by radionuclide clearance of 99mTc-diethylene triamine penta-acetic acid (DTPA) was investigated. METHODS: In 106 hypertensive subjects (53% men) aged 61.9±12.7 years with uncontrolled blood pressure (BP) receiving at least 2 antihypertensive medications, Aliskiren was added once-daily at a dose of 150-300 mg for 12 months. Clinic BP measurements were taken at every follow-up visit (1st, 6th and 12th month), while 24-hours ambulatory BP and GFR (in mL/min/1.73 m2) were evaluated at baseline and at the end of the follow-up. Analysis of variance for repeated measures of BP, GFR and microalbuminuria was provided. RESULTS: With the use of Aliskiren a significant reduction of BP and microalbuminuria was found (P<0.0001). Only in male population, a significant reduction in GFR calculated with CKD-EPI (82.4±15 vs. 78.6±18.2, P<0.01) and CG (81.6±29.5 vs. 74.2±28.4, P<0.0001) formulas was observed. This impairment of GFR was not found either with MDRD formula (70.5±19.6 vs. 68.3±23.4) or by radionuclide clearance (62.4±18.6 vs. 61.4±20.5). CONCLUSION: This study seems to demonstrate that the efficacy on BP control of Aliskiren is not accompanied by an impairment of GFR. In order to evaluate the effect of Aliskiren on GFR scintigraphy technique or MDRD formula resulted to be the most accurate methods.

Adhesion and growth of osteoblast-like cells on laser-engineered porous titanium surface: expression and localization of N-cadherin and beta-catenin.

Response of different types of cells on biomaterials is crucial for the applications of tissue engineering and regenerative medicine. It is recognized that cell behaviour depends largely on material surface characteristics. The purpose of this study was to define the biologic response of MG63 cells to the innovative patented surface SYNTHEGRA. MG63 morphology and distribution on the three different titanium disk surfaces (sandblasted, smooth, and laser-treated) were evaluated by microscopy analysis after staining with hematoxylin and eosin. Cell adhesion was determined by crystal violet assay at 48 h while proliferation and cytotoxicity were performed by MTT assay at 24, 48, 72 and 240 h. The expression and localization of N-cadherin and beta-catenin were studied by immunofluorescence and confocal microscopy. At 48 h the adhesion was similar in all titanium surfaces, no difference in cell viability were observed in all titanium disks when compared with controls, while the cell growth on laser-treated disks was significantly higher at 240 h than at 24 and 72 h. Morphological analysis show that cells are aligned along the grooves and inside the cavities. beta-catenin signal appeared more diffuse and localized underneath the cell membrane, while N-cadherin signal was fainter in cells grown on SYNTHEGRA surface. This work put into evidence the performance of newly designed laser-micromachined surface for adhesion, growth and distribution of human osteoblast-like cells. SYNTHEGRA surface inducing modification of N-cadherin and beta-catenin expression and localization, are suggestive of cells undergoing differentiation towards osteocytes and could be particularly suited for immediate load implant procedures.

FDG PET and 90Y ibritumomab tiuxetan in patients with follicular lymphoma.

AIM: Despite its established utility in non-Hodgkin's lymphoma, not much is reported on FDG positron emission tomography (PET) with respect to radioimmunotherapy (RIT). In this paper we investigate its value in patients affected by follicular lymphoma (FL) before and after treatment with [90Y]Ibritumomab Tiuxetan (Zevalin(R)). METHODS: We evaluated 38 relapsed or refractory FL patients. All had a PET scan performed before and 3 months after radioimmunotherapy. Final assessment was done 9 months post-RIT, including clinical evaluation, other imaging techniques and/or biopsy, when necessary. RESULTS: At the first PET scan 20 patients out of 38 had a limited disease (nodal involvement on one side of the diaphragm: 7 above and 13 below), 11 patients had nodal findings on both sides of the diaphragm and the remaining 7 patients had both nodal and extra-nodal findings. At three months post-RIT, 21 patients (55%) were in complete remission, 13 patients (34%) had a partial response (PR) and four patients (11%) had a progression disease (PD). The corresponding rates at final assessment were all consistent with the 3-month evaluation: 55% CR, 13% PR and 32% PD. FDG PET scan revealed maximal predictive values. When comparing the disease extent at relapse and the response to treatment, we could testify a higher rate of CR (75%) in patients with limited disease, while in patients with diffused nodal and/or extra-nodal findings, it was more frequent a PR or PD (66%). CONCLUSION: Our data are concordant with the expected results on RIT, and FDG PET is confirmed to be useful in assessing treatment response. Potential correlation can also be picked out between the disease extent at relapse and the CR rate, with reasonable PET predictivity for the final outcome.

The 18S rRNA is basically composed of two tandem quasirepeats. Insights into the evolution of some innate immunity receptors.

The gene encoding the 18S rRNA is an ancient molecule and its basic structure has been highly conserved from fish to mammals. Recently, we compared the nucleotide sequences of the human 18S rRNA and the human formyl peptide receptor 1 mRNA and concluded that selected segments of the two sequences exhibit similarities that are unlikely to be due simply to chance. Other data suggest the existence of nonrandom similarities between the 18S rRNA and the chemokine CXC receptor 4 mRNA. Therefore we advance the hypothesis that some groups of genes encoding 7-transmembrane G-coupled receptors of immunological interest may be evolutionarily related to the 18S gene. In this article we analyze the base-sequence architecture of the human 18S rRNA in terms of similarities between selected segments within the molecule. The method of study was based on the recording of the positions of 7- to 11-base oligonucleotide repeats, followed by a probabilistic analysis of the random occurrence of the repeats. Herein we show that most of the 18S rRNA molecule appears to be composed of two long tandem quasirepeats. We hypothesize that an ancestral gene structure composed of a chain of about 850 nucleotides duplicated to form a two-unit tandem repeat. Then the two units diverged as a consequence of independent nucleotide mutations, deletions, and insertions, but still retaining recognizable homologies. In addition, further nonduplicated shorter segments were added to build up the complete sequence.

Chemokine CXC receptor 4: an evolutionary approach.

Selected segments of the nucleotide sequences of the human 18S rRNA and the human formyl peptide receptor 1 mRNA exhibit structural similarities that are unlikely to be due simply to chance. Herein we analyze the structural similarities between the human 18S rRNA gene and the vertebrate chemokine CXC receptor 4 (CXCR4) gene that encodes a class A (rhodopsin-like) seven-transmembrane G-protein coupled receptor belonging to the same superfamily of formyl peptide receptors. The method of study was based on the recording of the positions of the 7-or-more-base oligonucleotide identities encountered in the 18S and CXCR4 genes and the construction of scatter-plots (abscissa-18S; ordinate-CXCR4) displaying the identity points positions. Analysis of the distribution of distances between identity points (abscissa-ordinate in the scatter-plot) demonstrated distinct peaks of frequency around 1200. Series of identities arranged near diagonal lines at 45 degrees in the scatter-plot (quasialignments) were evaluated for their probabilistic level of random occurrence. Results of this analysis demonstrated nonrandom quasialignments between (i) a 900-nt ca. section of the human CXCR4 intron that immediately precedes almost the whole of the coding sequence and the 18S gene from nt 125 to 1025 ca.; and (ii) a 425-nt ca. section of the CXCR4 vertebrate genes, corresponding to nt 137-560 of the coding sequence, and the 18S gene from nt 1300 to 1730 ca. In both instances significant quasialignments are evidenced when CXCR4 nt sequences are shifted to the right by about 1200 nt with respect to the 18S nt sequence, as confirmed by analysis of the abscissa - ordinate differences. Taken together, these results indicate that, at least in humans, a continuous nonrandom quasialignment extends for some 1600 nt, from the second part of the (single) intron to the first part of the coding sequence. We hypothesize that the relatively more recent CXCR4 vertebrate gene might be evolutionarily related to the more ancient and highly conserved 18S gene.

Biological role of the N-formyl peptide receptors.

Ligation of N-formyl-methionyl-leucyl-phenylalanine (fMLP) to its specific cell surface receptors triggers different cascades of biochemical events, eventually leading to cellular activation. The formyl peptide receptors (FPRs) are members of the seven-transmembrane, G-protein coupled receptors superfamily, expressed at high levels on polymorphonuclear and mononuclear phagocytes. The main responses elicited upon ligation of formylated peptides, referred to as cellular activation, are those of morphological polarization, locomotion, production of reactive-oxygen species and release of proteolytic enzymes. FPRs have in recent years been shown to be expressed also in several non myelocytic populations, suggesting other unidentified functions for this receptor family, independent of the inflammatory response. Finally, a number of ligands acting as exogenous or host-derived agonists for FPRs, as well as ligands acting as FPRs antagonists, have been described, indicating that these receptors may be differentially modulated by distinct molecules.

Gene expression profiling of adrenal cortical tumors by cDNA macroarray analysis. Results of a preliminary study.

Adrenocortical carcinoma (ACC) are highly malignant tumors with poor prognosis. To verify if it is possible to assess their differential gene expression by a cDNA macroarray analysis using RNA extracted from paraffin sections, we analyzed two different cohorts of adrenal cortical adenoma (ACA) and ACC. Paraffin sections of seven ACC and seven ACA were analyzed. Transcriptional profiles were generated by commercially available c-DNA arrays testing 82 genes. Hybridization signals were quantified by densitometry and the intensity signal was compared for each gene between ACA and ACC cohorts. RNA was successfully extracted in only four out of 14 cases. Four genes displayed a significantly different expression (ACC/ACA ratio>1.5 or<0.6). Heat shock protein 60 (HSP-60) (ratio>2), Ciclin D1 and topoisomerase I (ratio>1.5) were overexpressed in the ACC cohort, while jun proto-oncogene was down-regulated. cDNA macroarray analysis from paraffin sections of adrenal tumors is feasible, despite with a low success rate. The different expression of HSP-60, Ciclin D1, jun proto-oncogene and topoisomerase I indicates that these genes may play a role in ACC pathogenesis and could represent potential diagnostic/prognostic/therapeutic target markers. Larger series of patients are necessary to confirm the biologic, diagnostic, prognostic and therapeutic implications of these findings.

Structural similarities between mRNA for the formyl peptide receptors and 18S rRNA.

Formyl peptides released by some bacteria are powerful chemoattractants and activators of mammalian granulocytes and monocytes, acting through 7-transmembrane specific formyl peptide receptors (FPRs). Three distinct segments of the formyl peptide receptor 1 (FPR1) mRNA of Man share probabilistically significant homologies with segments of the 18S rRNA which are highly conserved from Drosophila to Man. Overall, the three segments cover approximately 24% that of the 18S rRNA sequence and approximately 36% of the FPR1 sequence. The three segments are, however, arranged in different orders in the 18S rRNAs and in the FPR1 mRNA, the segment appearing in the first location in the 18S rRNAs is located at the end of the FPR1 mRNA sequence. The hypothesis is advanced that the three "conserved" segments either derive from an ancestral gene that is the forerunner of both the ribosomal 18S genes and the FPR genes or that at some stage of evolution the FPR genes derived, at least in part, from the more ancient ribosomal 18S genes. The extant 18S rRNA sequences exhibit obvious signs of a number of breaks that occurred during evolution, especially in the transition from insects to vertebrates. Some of these events may have resulted in differential rearrangements of segments in the groups of FPR genes and ribosomal 18S genes.

Power spectral analysis of the shape of fMLP-stimulated granulocytes. A tool for the study of cytoskeletal organization under normal and pathological conditions.

fMLP (N-formyl-methionyl-leucyl-phenylalanine) is a powerful activator of granulocytes, eliciting different metabolic responses, such as generation of reactive oxygen species, production of arachidonic acid metabolites, and release of lysosomal enzymes. fMLP determines also a dramatic rearrangement of the actin cytoskeleton; under non-gradient conditions this entails characteristic alterations in cell shape (chemokinesis), while under gradient conditions it is instrumental in promoting cell migration up the gradient (chemotaxis). Here we analyze mathematically the cell contour of fMLP-stimulated human granulocytes stimulated with fMLP under non-gradient conditions, using the methods for study of stochastic series. The cell contours were drawn and divided into 200 segments of equal linear length and the angles between consecutive segments were computed. The derived series of angles were examined for autocorrelations and from the autocorrelation function the power spectrum was calculated. Our results show that the pattern of lamellipodial extensions of the cell membrane is not entirely randomly-designed, but it is partly regulated by deterministic components, as revealed by the presence of statistically significant periodicities. Soon after fMLP stimulation, the power spectrum of the cell contours exhibits a single distinct peak at frequency 0.07, indicating a prevalence of prominent lamellipodia, each one covering in the average 1/15 of the linearized cell contour. Some 30 min after fMLP stimulation the power spectrum becomes flatter (indicating a general decrement of the deterministic component), but still presents one single peak; the latter is shifted to the right (frequency 0.13), indicating the prevalence of less prominent and regular, but more numerous, protrusions, each one covering 1/20 to 1/30 of the cell contour.

In vivo effects of recombinant-interferon-beta1b treatment on polymorphonuclear cell and monocyte functions and on T-cell-mediated antibacterial activity in patients with relapsing-remitting multiple sclerosis.

Treatment with Interferon (IFN)-beta has been proposed as a therapeutic approach in multiple sclerosis (MS) patients, mostly in view of its immunomodulating actions. At the same time, evidence has been provided that MS patients exhibit polymorphonuclear cell (PMN) deficits, which can explain the increased susceptibility to infections in these subjects. Here, in 28 patients with relapsing-remitting (RR) MS under treatment with recombinant (r)-IFN-beta PMN polarization and PMN and monocyte (MO) phagocytosis and killing, as well as T-cell mediated antibacterial activity, were evaluated before treatment and over a period of nine months of treatment. Our results point out an enhanced rate of polarization (both "spontaneous" or N-formyl-methionyl-leucyl-phenylalanine-induced) in MS patients. After r-IFN-beta1b treatment the polarization rate was further increased. On the contrary, PMN and MO phagocytosis and killing were depressed in comparison to controls and values were further reduced by r-IFN-beta1b treatment. In patients T-cell mediated antibacterial activity was decreased at T0 and dramatically dropped in the course of r-IFN-beta1b therapy.

Stress, neuropsychiatric disorders and immunological effects exerted by benzodiazepines.

Psychoneuroimmunology is a growing scientific field which deals with the mutual interplay between nervous and immune systems. In this framework, many data have demonstrated that cytokines (CKs) derived from the periphery are able to cross the blood brain barrier and act upon the central nervous system (CNS) [e.g., the hypothalamic-pituitary-adrenal axis (HPAA)], thus regulating several physiological functions (thermoregulation, sleep, appetite) or damaging the nervous tissue, when released in exaggerated amounts. On the other hand, nervous cells, such as astrocytes and microglial cells also generate proinflammatory CKs which may be detrimental for the CNS. The neuromodulating CK network can be triggered by microorganisms and/or their products (i.e. bacterial endotoxins), but also stressful life events may activate the HPAA, thus affecting the immune system function. This review will place emphasis on some clinical conditions, such as phobia and migraine without aura (MWA), characterized by anxiety disorders. Patients affected by these neuropsychiatric alterations exhibit multiple functional deficits of phagocytes and T lymphocytes which allow penetration of various pathogens into the host. This is also supported by the detection of circulating bacterial endotoxins and the evidence of both spontaneous and induced exaggerated release of proinflammatory CKs in phobic and MWA patients. The possible iatrogenic effects of benzodiazepines (BDZ) on the immune system have been evaluated by in vitro and in vivo studies. In this respect, it emerges that diazepam exerts an inhibitory function on the immune system, while alprazolam behaves as an immunoenhancer. The presence of central and/or peripheral BDZ receptors on immune cells seems to be the key mechanism responsible for the immunomodulation exerted by these drugs.

In vitro effects of 3'-azido-3'-deoxythymidine (AZT) on normal human polymorphonuclear cell and monocyte-macrophage functional capacities.

The in vitro effects of 3'-azido-3'-deoxythymidine (AZT) (at concentrations of 1, 10 and 100 microM, respectively) on normal human polymorphonuclear cell (PMN) and monocyte-macrophage functional capacities were evaluated. Results show that AZT was able to decrease monocyte phagocytosis only, while PMN polarization, phagocytosis and killing were unaffected by drug pretreatment. Quite interestingly, monocyte-derived macrophages maintained their unaltered phagocytic function in spite of the presence of AZT in overnight cultures, thus indicating that monocytes are more susceptible than macrophages to the antiproliferative effects of AZT. Since our data indicate that AZT affects normal human monocyte phagocytosis, it is advisable to evaluate this immune parameter in HIV+ patients administered with this drug.

Downregulation of human polymorphonuclear cell activities exerted by microorganisms belonging to the alpha-2 subgroup of Proteobacteria (Afipia felis and Rochalimaea henselae).

Intracellular pathogens have evolved effective mechanisms in order to survive in an intracellular environment, thus avoiding destruction by phagocytic cells. In this regard, a correlation between resistance to phagocytic killing and expression of pathogenic potency has been established. In this report, we have studied the interaction between human polymorphonuclear cells (PMN) and two gram-negative microorganisms, Afipia felis and Rochalimaea henselae, which belong to the alpha-2 subgroup of the class Proteobacteria. A. falis has been previously proposed as the causative agent of Cat Scratch Disease (CSD), but several recent lines of evidence attribute a major role to R. henselae. Of note, CSD is a syndrome characterized by a chronic lymphoadenopathy, involving macrophages and endothelial cells with a progression towards a granulomatous process and/or angiogenesis. Since members of the alpha-2 subgroup of Proteobacteria have the property to survive intracellularly, we have evaluated the effects exerted by A. felis and R. henselae on human PMN in terms of chemotaxis locomotion, degranulation and oxidative metabolism. Results will show an impairment of PMN activities as a consequence of the challenge with both microrganisms. In particular, inhibition of PMN oxidative function occurred either as result of a direct exposure to both A. felis and R. henselae or when PMN were primed by bacteria for the N-formyl-methionyl-leucyl-phenylalanine enhancement of the oxidative burst. These findings may account for the ability of A. felis and R. henselae to survive within PMN as expression of a further mechanism of pathogenic potency, influencing also the nature and the evolution of inflammatory response in the lesion sites.

Rochalimaea henselae organisms possess an elevated capacity of binding to peripheral blood lymphocytes from patients with cat scratch disease.

Cat scratch disease (CSD) is a clinical condition whose aetiological agent, according to recent findings, is of bacterial origin. Two Gram-negative bacteria are invoked as causative agents of CSD, namely Afipia felis and Rochalimaea henselae. In this paper, five patients with suspected CSD were studied in terms of binding capacity of A. felis and R. henselae to their own peripheral blood lymphocytes (PBL). This parameter was correlated with serum antibody titres to both A. felis and R. henselae, as determined by an indirect fluorescence assay (IFA). Results demonstrate that in four out of five cases binding of R. henselae to PBL was higher than that observed with A. felis. In two cases serum antibody titres to both bacteria were lower or absent, while in the other two patients serum antibody titres to R. henselae were significantly high. In one case only, characterized by elevated titres of serum antibodies to A. felis, values of cytoadherence exhibited by this bacterium were similar to those observed with R. henselae. The results suggest that bacterial binding to lymphocytes may represent an additional parameter to support diagnosis of CSD.

In vivo effects of alprazolam and lorazepam on the immune response in patients with migraine without aura.

Over the past few years, the immunomodulating role of benzodiazepines (BDZ) has been reported in literature. In particular, diazepam is an inhibitory BDZ with regard to its effects on the phagocytic and metabolic activities of polymorphonuclear cells (PMN) and monocytes, while triazolobenzodiazepines (alprazolam and triazolam) upregulate normal human peripheral blood T lymphocyte function. On these grounds, the administration of alprazolam (1 mg/per day for 1 month) in 13 patients with migraine without aura (MWA) and of lorazepam (2 mg/per day for 1 month) in 10 matched MWA subjects has been evaluated in terms of immune response. Results show that before administration of BDZ in both groups of patients phagocytosis and killing of PMN and monocytes were profoundly depressed and the same was true for the lymphocyte-dependent antibacterial activity. After one month treatment lorazepam further decreased lymphocyte function without modifying phagocytic capabilities. On the contrary, alprazolam increased PMN phagocytosis and killing and monocyte phagocytosis without modifying antibacterial activity values. Taken together, these results further support the existence of different classes of BDZ in terms of their immunomodulating capacities. Moreover, alprazolam seems to be a more appropriate BDZ for treating immunocompromised patients, even including MWA patients.

Triazolobenzodiazepines exert immunopotentiating activities on normal human peripheral blood lymphocytes.

Previous studies have demonstrated that benzodiazepines (BDZ) (e.g. diazepam) inhibit immune responsiveness. Since these drugs are largely used in psychiatric patients it is of great importance to verify the existence of different types of BDZ, which are not suppressive for the immune system. In this framework, our results indicate that alprazolam and triazolam, two triazolo-BDZ, do not modify in vitro phagocytosis and killing exerted by normal human polimorphonuclear cells and monocytes. On the contrary, they significantly enhance T lymphocyte-dependent antibacterial activity in normal donors. These data support the concept that triazolo-BDZ and, in particular, alprazolam may represent more appropriate drugs for the treatment of psychiatric patients (e.g. patients with phobic disorders and/or migraine) who display immunodeficits.

Somnogenic cytokines with special reference to interleukin-1.

Cytokines (CKs) are involved in the mechanisms of sleep induction, and, in particular, interleukin-1 (IL-1) and tumor necrosis factor-alpha seem to play an important role in the slow-wave sleep. Here are reported two cases of normal sleep and altered sleep in which plasma levels of IL-1 beta have been determined. In the subject with a normal sleep a dramatic increase of this CK has been observed, while beta-endorphin levels were reduced. In the light of these findings, the role of sleep in the host protection is discussed.

Effects of benzodiazepines on the immune system.

Benzodiazepines (BDZ) are psychotropic drugs largely used in patients with affective disorders. As far as their effects on the immune system are concerned, a few studies have been carried out until now. Diazepam is inhibitory in vitro for the phagocytic functions and the antibody synthesis, being its action mediated via specific receptors on immunocompetent cells. On the contrary, alprazolam results to be enhancing for the antibacterial activity exerted by normal human peripheral blood T lymphocytes in vitro. Taken together, these data point out the different role which BDZ play on the immune response.