Nickel free-diet enhances the Helicobacter pylori eradication rate: a pilot study

BACKGROUND

The Helicobacter pylori eradication rate with standard triple therapy is very low. H. pylori is known to require the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive at the low pH environment in the stomach.

AIM

To compare the H. pylori eradication rate of a nickel free-diet associated with standard triple therapy and standard triple therapy alone as the first-line regimen.

METHODS

Fifty-two sex- and age-matched patients at the first diagnosis of H. pylori infection were randomized 1:1 into two different therapeutic schemes: (1) standard LCA (26 patients): lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid for 7 days with a common diet; (2) standard LCA plus a nickel free-diet (NFD-LCA) (26 patients). Patients followed 30 days of a nickel-free diet plus a week of lansoprazole 15 mg bid, clarithromycin 500 mg bid and amoxicillin 1,000 mg bid starting from day 15 of the diet.

RESULTS

All patients completed the study. A significantly higher eradication rate was observed in the NFD-LCA group (22/26) versus LCA group (12/26) (p < 0.01). Only a few patients (9 of 52) reported the occurrence of mild therapy-related side effects, without any significant differences between the two groups.

CONCLUSIONS

The addition of a nickel-free diet to standard triple therapy significantly increases the H. pylori eradication rate. The reduction of H. pylori urease activity due to the nickel-free diet could expose the bacterium to gastric acid and increase H. pylori's susceptibility to amoxicillin. Further studies are necessary to confirm this preliminary result.

[Diagnostic approach to phlogoses: the validity of procalcitonin]

AIM

The aim of our study is to compare the potential usefulness of procalcitonin with the CRP as a diagnostic marker of pediatric diseases and to define the diagnostic accuracy and relation with the inflammation etiology and severity of procalcitonin.

METHODS

The analysis focused on a sample of 141 children, hospitalized for fever with bacterial, viral or inflammatory etiology, studied at the time of admission in the Hospital, and after defervescence. The sensitivity, the specificity, the positive and negative predictive value have been calculated for the both tests, explained above.

RESULTS

The diagnostic accuracy of procalcitonin is the same as the one of PCR in all cases. The result of the test has been positive in 85,7% of the serious infections and has been useful to identifiy the etiology of infections in almost 2/3 of patients.

CONCLUSION

Procalcitonin seems to be a promising marker of infections because of its following features: a larger contribution in the monitoring phase (fast positivization and normalization); the diagnostic accuracy and a good correlation with the etiology and the severity of infections. Nonetheless, the routine use of procalcitonin is not recommended in the light of the uncertainty on the optimal cut-off and the still high costs.

Role of disorder in the thermodynamics and atomic dynamics of glasses

We measured the density of vibrational states (DOS) and the specific heat of various glassy and crystalline polymorphs of SiO2. The typical (ambient) glass shows a well-known excess of specific heat relative to the typical crystal (α-quartz). This, however, holds when comparing a lower-density glass to a higher-density crystal. For glassy and crystalline polymorphs with matched densities, the DOS of the glass appears as the smoothed counterpart of the DOS of the corresponding crystal; it reveals the same number of the excess states relative to the Debye model, the same number of all states in the low-energy region, and it provides the same specific heat. This shows that glasses have higher specific heat than crystals not due to disorder, but because the typical glass has lower density than the typical crystal.

Management of acute dyarrhea: current and future trends

Acute diarrhea is a very common symptom, which may recognize different causes and is basically the expression of an altered homeostasis of the bowel, which overcame current classifications. When approaching patients with acute diarrhea, we should firstly check body temperature and vital parameters and secondly provide a general medical examination mainly focused on the abdomen, in order to exclude surgical causes of diarrhea, such as acute appendicitis, diverticulitis, intestinal occlusion and others. Another important aspect is the assessment of the level of hydration in order to provide the right amount of fluids. There is no current indication for the administration of loperamide in infectious diarrhea, but there is a strong rationale for new class of drugs, which may be defined as "mucous regenerators", such as gelatin tannate. Further studies are needed on this matter in order to test the effect of gelatin tannate in adult patients with acute diarrhea.

Glycosphingolipids: synthesis and functions

Glycosphingolipids (GSLs) comprise a heterogeneous group of membrane lipids formed by a ceramide backbone covalently linked to a glycan moiety. Hundreds of different glycans can be linked to tens of different ceramide molecules, giving rise to an astonishing variety of structurally different compounds, each of which has the potential for a specific biological function. GSLs have been suggested to modulate membrane-protein function and to contribute to cell-cell communication. Although GSLs are dispensable for cellular life, they are indeed collectively required for the development of multicellular organisms, and are thus considered to be key molecules in 'cell sociology'. Consequently, the GSL make-up of individual cells is highly dynamic and is strictly linked to the cellular developmental and environmental state. In the present review, we discuss some of the available knowledge, open questions and future perspectives relating to the study of GSL biology.

[Diagnostic approach to flogosis: procalcitonin validity]

AIM

The aim of our study was to compare the potential usefulness of procalcitonin with the CRP as a diagnostic marker of pediatric diseases and to define the diagnostic accuracy and relation with the inflammation etiology and severity of procalcitonin.

METHODS

The analysis focused on a sample of 141 children, hospitalized for fever with bacterial, viral or inflammatory etiology, studied at the time of admission in the Hospital, and after defervescence. The sensitivity, the specificity, the positive and negative predictive value have been calculated for the both tests, explained above.

RESULTS

The diagnostic accuracy of procalcitonin is the same as the one of PCR in all cases. The result of the test has been positive in 85.7% of the serious infections and has been useful to identify the etiology of infections in almost 2/3 of patients.

CONCLUSION

Procalcitonin seems to be a promising marker of infections because of its following features: a larger contribution in the monitoring phase (fast positivization and normalization); the diagnostic accuracy and a good correlation with the etiology and the severity of infections. Nonetheless, the routine use of procalcitonin is not recommended in the light of the uncertainty on the optimal cut-off and the still high costs.

Diagnosis of small intestinal bacterial overgrowth in the clinical practice

BACKGROUND

Gut microbiota plays several beneficial effects on the human host. Its qualitative and/or quantitative unbalance may facilitate the occurrence of small intestinal bacterial overgrowth (SIBO).

AIM

To review the available data in order to propose a practical approach to SIBO diagnosis in the clinical setting.

MATERIALS AND METHODS

Full papers from 1990 to present available on the Pubmed database concerning the topic of SIBO diagnosis were critically reviewed.

RESULTS

SIBO is common in the presence of one or more predisposing conditions. The clinical picture of SIBO patients is extremely variable, depending of underlying disorders, and both patients and microbiota characteristics. SIBO could be asymptomatic, or leading to aspecific gastrointestinal IBS-like symptoms. In worst cases it may configure a real malabsorption syndrome. Culture of intestinal aspirates remains at present the gold standard for SIBO diagnosis. However a lot of limitations including high costs and invasivity prevent from using this test in the clinical practice. Hydrogen lactulose and especially glucose breath tests are at present the most utilized to reach SIBO diagnosis in the clinical setting, due to their low costs, non invasivity, sufficient accuracy and reproducibility.

CONCLUSIONS

SIBO should be suspected in the presence of IBS-like symptoms and/or malabsorption syndrome occurring in the presence of disorders predisposing to SIBO development. The most common diagnostic tool is represented at present by hydrogen breath tests.

13C-Urea breath test for the diagnosis of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a Gram-negative bacterium able to colonize the gastric mucosa as well as gastric metaplastic areas of the duodenum, producing inflammation. The clinical outcome depends on sophisticated interactions between bacterial factors, such as the expression of determinants of virulence and pathogenicity, and host characteristics. The severity of inflammation, may then vary among different subjects, leading to the occurrence of different gastroduodenal diseases, ranging from chronic gastritis to gastric cancer and MALT-lymphoma, to some defined extragastric manifestations. Many diagnostic tests are available for the detection of H. pylori infection including noninvasive methods, such as serology, (13)C-urea breath test (UBT), and fecal antigen tests and invasive techniques, including a combined use of endoscopic biopsy-based methods, such as rapid urease testing, histology, culture, and molecular methods. UBT is a highly sensitive and specific and allows to diagnose the presence or absence of infection of H. pylori, through the oral administration of a solution containing urea labelled with the non-radioactive natural carbon 13. This review article analyzes microbiological and clinical features of H. pylori as well as the different diagnostic tests able to detect this bacterium with a special focus on UBT.

Tricks for interpreting and making a good report on hydrogen and 13C breath tests

Breath tests (BT) represent a valid and non-invasive diagnostic tool in many gastroenterological disorders. Their wide diffusion is due to the low cost, simplicity and reproducibility and their common indications include diagnosis of carbohydrate malabsorption, Helicobacter pylori infection, small bowel bacterial overgrowth, gastric emptying time and orocaecal transit time. The review deals with key points on methodology, which would influence the correct interpretation of the test and on a correct report. While a clear guideline is available for lactose and glucose breath tests, no gold standard is available for Sorbitol, Fructose or other H2 BTs. Orocaecal transit time (OCTT) defined as time between assumption of 10 g lactulose and a peak > 10 ppm over the baseline value, is a well-defined breath test. The possible value of lactulose as a diagnostic test for the diagnosis of small bowel bacterial overgrowth is still under debate. Among (13)C breath test, the best and well characterized is represented by the urea breath test. Well-defined protocols are available also for other (13)C tests, although a reimbursement for these tests is still not available. Critical points in breath testing include the patient preparation for test, type of substrate utilized, reading machines, time between when the test is performed and when the test is processed. Another crucial point involves clinical conclusions coming from each test. For example, even if lactulose could be utilized for diagnosing small bowel bacterial overgrowth, this indication should be only secondary to orocaecal transit time, and added into notes, as clinical guidelines are still uncertain.

Lactose intolerance: from diagnosis to correct management

This review discusses one of the most relevant problems in gastrointestinal clinical practice: lactose intolerance. The role of lactase-persistence alleles the diagnosis of lactose malabsorption the development of lactose intolerance symptoms and its management. Most people are born with the ability to digest lactose, the major carbohydrate in milk and the main source of nutrition until weaning. Approximately, 75% of the world's population loses this ability at some point, while others can digest lactose into adulthood. Symptoms of lactose intolerance include abdominal pain, bloating, flatulence and diarrhea with a considerable intraindividual and interindividual variability in the severity. Diagnosis is most commonly performed by the non invasive lactose hydrogen breath test. Management of lactose intolerance consists of two possible clinical choice not mutually exclusive: alimentary restriction and drug therapy.

Low-energy vibrational dynamics of cesium borate glasses

Low-temperature specific heat and inelastic light scattering experiments have been performed on a series of cesium borate glasses and on a cesium borate crystal. Raman measurements on the crystalline sample have revealed the existence of cesium rattling modes in the same frequency region where glasses exhibit the boson peak (BP). These localized modes are supposed to overlap with the BP in cesium borate glasses affecting its magnitude. Their influence on the low frequency vibrational dynamics in glassy samples has been considered, and their contribution to the specific heat has been estimated. Evidence for a relation between the changes of the BP induced by the increased amount of metallic oxide and the variations of the elastic medium has been provided.

Reverse engineering and analysis of genome-wide gene regulatory networks from gene expression profiles using high-performance computing

Regulation of gene expression is a carefully regulated phenomenon in the cell. “Reverse-engineering” algorithms try to reconstruct the regulatory interactions among genes from genome-scale measurements of gene expression profiles (microarrays). Mammalian cells express tens of thousands of genes; hence, hundreds of gene expression profiles are necessary in order to have acceptable statistical evidence of interactions between genes. As the number of profiles to be analyzed increases, so do computational costs and memory requirements. In this work, we designed and developed a parallel computing algorithm to reverse-engineer genome-scale gene regulatory networks from thousands of gene expression profiles. The algorithm is based on computing pairwise Mutual Information between each gene-pair. We successfully tested it to reverse engineer the Mus Musculus (mouse) gene regulatory network in liver from gene expression profiles collected from a public repository. A parallel hierarchical clustering algorithm was implemented to discover “communities” within the gene network. Network communities are enriched for genes involved in the same biological functions. The inferred network was used to identify two mitochondrial proteins.

Identification of microRNA-regulated gene networks by expression analysis of target genes

MicroRNAs (miRNAs) and transcription factors control eukaryotic cell proliferation, differentiation, and metabolism through their specific gene regulatory networks. However, differently from transcription factors, our understanding of the processes regulated by miRNAs is currently limited. Here, we introduce gene network analysis as a new means for gaining insight into miRNA biology. A systematic analysis of all human miRNAs based on Co-expression Meta-analysis of miRNA Targets (CoMeTa) assigns high-resolution biological functions to miRNAs and provides a comprehensive, genome-scale analysis of human miRNA regulatory networks. Moreover, gene cotargeting analyses show that miRNAs synergistically regulate cohorts of genes that participate in similar processes. We experimentally validate the CoMeTa procedure through focusing on three poorly characterized miRNAs, miR-519d/190/340, which CoMeTa predicts to be associated with the TGFβ pathway. Using lung adenocarcinoma A549 cells as a model system, we show that miR-519d and miR-190 inhibit, while miR-340 enhances TGFβ signaling and its effects on cell proliferation, morphology, and scattering. Based on these findings, we formalize and propose co-expression analysis as a general paradigm for second-generation procedures to recognize bona fide targets and infer biological roles and network communities of miRNAs.

Connecting vesicular transport with lipid synthesis: FAPP2

Next to the protein-based machineries composed of small G-proteins, coat complexes, SNAREs and tethering factors, the lipid-based machineries are emerging as important players in membrane trafficking. As a component of these machineries, lipid transfer proteins have recently attracted the attention of cell biologists for their involvement in trafficking along different segments of the secretory pathway. Among these, the four-phosphate adaptor protein 2 (FAPP2) was discovered as a protein that localizes dynamically with the trans-Golgi network and regulates the transport of proteins from the Golgi complex to the cell surface. Later studies have highlighted a role for FAPP2 as lipid transfer protein involved in glycosphingolipid metabolism at the Golgi complex. Here we discuss the available evidence on the function of FAPP2 in both membrane trafficking and lipid metabolism and propose a mechanism of action of FAPP2 that integrates its activities in membrane trafficking and in lipid transfer. This article is part of a Special Issue entitled Lipids and Vesicular Transport.

Phosphoinositides in Golgi complex function

The Golgi complex is a ribbon-like organelle composed of stacks of flat cisternae interconnected by tubular junctions. It occupies a central position in the endomembrane system as proteins and lipids that are synthesized in the endoplasmic reticulum (ER) pass through the Golgi complex to undergo biosynthetic modification (mainly glycosylation) and to be sorted to their final destinations. In addition the Golgi complex possesses a number of activities, apparently not directly connected with its main role in trafficking and sorting, which have been recently reviewed in Wilson et al. 2011. In spite of the constant massive flux of material the Golgi complex maintains its identity and phosphoinositides (PIs), among other factors, play a central role in this process. The active metabolism of PIs at the Golgi is necessary for the proper functioning of the organelle both in terms of membrane trafficking/sorting and its manifold metabolic and signalling activities. Phosphatidylinositol 4-phosphate (PtdIns4P), in particular, is responsible for the recruitment of numerous cytosolic proteins that recognise and bind PtdIns4P via specific lipid-binding domains. In this chapter we will summarize the findings that have contributed to our current understanding of the role of PIs in the biology of the Golgi complex in terms of the regulation of PI metabolism and the functional roles and regulation of PtdIns4P effectors.

[Ultrasound and MRI measurements investigation in juvenile idiopatic arthritis]

The juvenile idiopatic arthritis (JIA) is the childhood most common rheumatologic disorder. The JIA diagnosis is not based on specific clinical and serological markers, but mainly on the ultrasound and magnetic resonance imaging investigations. The use of both these imaging techniques seem to be very promising, especially for the ultrasound. In fact, the improvement in both the ultrasound methods (power e colour Doppler, high resolution technique) and the operator knowledge could give the same results of the MRI imaging leading to a better cost-benefit ratio.

Comparison between siliconized evacuated glass and plastic blood collection tubes for prothrombin time and activated partial thromboplastin time assay in normal patients, patients on oral anticoagulant therapy and patients with unfractioned heparin therapy

INTRODUCTION

The study was designed to evaluate whether there was a statistically significant effect between evacuated glass tubes and plastic tubes on prothrombin time (PT) and activated partial thromboplastin time (aPTT).

METHODS

Blood samples were drawn into four different tubes from three patient populations-apparently healthy patients, patients on oral anticoagulant therapy with vitamin K antagonists (OAT-vka) and patients being treated with unfractioned heparin (UFH). Testing was performed on an automated coagulation analyzer, and statistical analysis was achieved using a test of variance (anova).

RESULTS

For normal patients, there were no statistically significant differences for the aPTT test; however, there were statistically significant differences for the PT test. For patients on OAT-vka, statistically significant differences were clearly observed between the four tube types for the PT test. For patients treated with UFH, there were no statistically significant differences for the aPTT test.

CONCLUSION

The data showed a statistically significant difference between glass and plastic tubes in the normal population only for the PT test, with consequent repercussions for patients on OAT. This means that appropriate care and validation should take place whenever there is a change in tube type.

GRASP65 and GRASP55 sequentially promote the transport of C-terminal valine-bearing cargos to and through the Golgi complex

The Golgi matrix proteins GRASP65 and GRASP55 have recognized roles in maintaining the architecture of the Golgi complex, in mitotic progression and in unconventional protein secretion whereas, surprisingly, they have been shown to be dispensable for the transport of commonly used reporter cargo proteins along the secretory pathway. However, it is becoming increasingly clear that many trafficking machineries operate in a cargo-specific manner, thus we have investigated whether GRASPs may control the trafficking of selected classes of cargo. We have taken into consideration the C-terminal valine-bearing receptors CD8alpha and Frizzled4 that we show bind directly to the PSD95-DlgA-zo-1 (PDZ) domains of GRASP65 and GRASP55. We demonstrate that both GRASPs are needed sequentially for the efficient transport to and through the Golgi complex of these receptors, thus highlighting a novel role for the GRASPs in membrane trafficking. Our results open new perspectives for our understanding of the regulation of surface expression of a class of membrane proteins, and suggests the causal mechanisms of a dominant form of autosomal human familial exudative vitreoretinopathy that arises from the Frizzled4 mutation involving its C-terminal valine.

The multiple roles of PtdIns(4)P -- not just the precursor of PtdIns(4,5)P2

The phosphoinositides (PIs) are membrane phospholipids that actively operate at membrane-cytosol interfaces through the recruitment of a number of effector proteins. In this context, each of the seven different PI species represents a topological determinant that can establish the nature and the function of the membrane where it is located. Phosphatidylinositol 4-phosphate (PtdIns(4)P) is the most abundant of the monophosphorylated inositol phospholipids in mammalian cells, and it is produced by D-4 phosphorylation of the inositol ring of PtdIns. PtdIns(4)P can be further phosphorylated to PtdIns(4,5)P(2) by PtdIns(4)P 5-kinases and, indeed, PtdIns(4)P has for many years been considered to be just the precursor of PtdIns(4,5)P(2). Over the last decade, however, a large body of evidence has accumulated that shows that PtdIns(4)P is, in its own right, a direct regulator of important cell functions. The subcellular localisation of the PtdIns(4)P effectors initially led to the assumption that the bulk of this lipid is present in the membranes of the Golgi complex. However, the existence and physiological relevance of ;non-Golgi pools' of PtdIns(4)P have now begun to be addressed. The aim of this Commentary is to describe our present knowledge of PtdIns(4)P metabolism and the molecular machineries that are directly regulated by PtdIns(4)P within and outside of the Golgi complex.

Lipid-transfer proteins in biosynthetic pathways

Compartmentalization is a defining feature of eukaryotic cells that allows the spatial segregation of different functions, such as protein and lipid synthesis, and ensures their fidelity and efficiency. This imposes the need for an intense flux of metabolic intermediates between segregated enzymatic activities, as seen for the sequential transport of neosynthesized proteins through the segments of the secretory pathway during their post-translational modification. For lipid synthesis, the identification of proteins that transfer lipids between membranes has revealed an additional mechanism for this intercompartment exchange. The intense interest elicited by the lipid-transfer proteins over the last few years has led to the definition of their central role in key processes, such as lipid metabolism, membrane trafficking, and signaling.

Glycosphingolipid synthesis requires FAPP2 transfer of glucosylceramide

The molecular machinery responsible for the generation of transport carriers moving from the Golgi complex to the plasma membrane relies on a tight interplay between proteins and lipids. Among the lipid-binding proteins of this machinery, we previously identified the four-phosphate adaptor protein FAPP2, the pleckstrin homology domain of which binds phosphatidylinositol 4-phosphate and the small GTPase ARF1. FAPP2 also possesses a glycolipid-transfer-protein homology domain. Here we show that human FAPP2 is a glucosylceramide-transfer protein that has a pivotal role in the synthesis of complex glycosphingolipids, key structural and signalling components of the plasma membrane. The requirement for FAPP2 makes the whole glycosphingolipid synthetic pathway sensitive to regulation by phosphatidylinositol 4-phosphate and ARF1. Thus, by coupling the synthesis of glycosphingolipids with their export to the cell surface, FAPP2 emerges as crucial in determining the lipid identity and composition of the plasma membrane.

The role of the phosphoinositides at the Golgi complex

Eukaryotic cells are organized into a complex system of subcompartments, each with its distinct protein and lipid composition. A continuous flux of membranes crosses these compartments, and in some cases direct connections exist between the different organelles. It is thus surprising that they can maintain their individual identities. Small GTPases and the phosphoinositides have emerged as the key regulators in the maintenance of the identity of the Golgi complex. This property is due to their ability to act either alone or, more often, in combination, as cues directing and controlling the recruitment of proteins that possess phosphoinositide-binding domains. Among these many proteins there are the lipid transfer proteins, which can transfer ceramide, oxysterol, cholesterol and possibly glucosylceramide. By regulating these lipid transfer proteins in this way, this binomial combination of the small GTPases and the phosphoinositides acquires a further important role: control of the synthesis and/or distribution of other important integral constituents of cell organelles, such as the sphingolipids and cholesterol. This role is particularly relevant at the level of the Golgi complex, a key organelle in the biosynthesis, transport and sorting of both lipids and proteins that is located at the intersection of the secretory and endocytic pathways.

Lipid-transfer proteins in membrane trafficking at the Golgi complex

The Golgi complex (GC) represents the central junction for membrane trafficking. Protein and lipid cargoes continuously move through the GC in both anterograde and retrograde directions, departing to and arriving from diverse destinations within the cell. Nevertheless, the GC is able to maintain its identity and strict compartmentalisation, having a different composition in terms of protein and lipid content compared to other organelles. The discovery of coat protein complexes and the elucidation of their role in sorting cargo proteins into specific transport carriers have provided a partial answer to this phenomenon. However, it is more difficult to understand how relatively small and diffusible molecules like lipids can be concentrated in or excluded from specific subcellular compartments. The discovery of lipid-transfer proteins operating in the secretory pathway and specifically at the GC has shed light on one possible way in which this lipid compartmentalisation can be accomplished. The correct lipid distribution along the secretory pathway is of crucial importance for cargo protein sorting and secretion. This review focuses on what is now known about the putative and effective lipid-transfer proteins at the GC, and on how they affect the function and structure of the GC itself.

Neutron spectrometry with a monolithic silicon telescope

A neutron spectrometer was set-up by coupling a polyethylene converter with a monolithic silicon telescope, consisting of a DeltaE and an E stage-detector (about 2 and 500 microm thick, respectively). The detection system was irradiated with monoenergetic neutrons at INFN-Laboratori Nazionali di Legnaro (Legnaro, Italy). The maximum detectable energy, imposed by the thickness of the E stage, is about 8 MeV for the present detector. The scatter plots of the energy deposited in the two stages were acquired using two independent electronic chains. The distributions of the recoil-protons are well-discriminated from those due to secondary electrons for energies above 0.350 MeV. The experimental spectra of the recoil-protons were compared with the results of Monte Carlo simulations using the FLUKA code. An analytical model that takes into account the geometrical structure of the silicon telescope was developed, validated and implemented in an unfolding code. The capability of reproducing continuous neutron spectra was investigated by irradiating the detector with neutrons from a thick beryllium target bombarded with protons. The measured spectra were compared with data taken from the literature. Satisfactory agreement was found.

Performance of a neutron spectrometer based on a PIN diode

The neutron spectrometer discussed in this work consists of a PIN diode coupled with a polyethylene converter. Neutrons are detected through the energy deposited by recoil-protons in silicon. The maximum detectable energy is -6 MeV and is imposed by the thickness of the fully depleted layer (300 microm for the present device). The minimum detectable energy which can be assessed with pulse-shape discrimination (PSD) is -0.9 MeV. PSD is performed with a crossover method and setting the diode in the 'reverse-injection' configuration (i.e. with the N+ layer adjacent to the converter). This configuration provides longer collection times for the electron-hole pairs generated by the recoil-protons. The limited interval of detectable energies restricts the application of this spectrometer to low-energy neutron fields, such as the ones which can be produced at facilities hosting low-energy ion accelerators. The capacity to reproduce continuous neutron spectra was investigated by optimising the electronic chain for pulse-shape discrimination. In particular, the spectrometer was irradiated with neutrons that were generated by striking a thick beryllium target with protons of several energies and the measured spectra were compared with data taken from the literature.

Transient middle cerebral artery occlusion influence on systemic oxygen homeostasis and erythropoiesis in Wistar rats

BACKGROUND AND PURPOSE

Systemic hypoxia is a common complication in stroke patients and may exacerbate ischemic brain damage. Expression of the hypoxia-inducible cytokine erythropoietin (Epo) is upregulated in the brain in both stroke patients and in animal stroke models and exerts local neuroprotective effects in the ischemic brain. Epo is also well known to stimulate red blood cell (RBC) production. The purpose of the present study was to evaluate whether poststroke systemic hypoxia is present in the rat model and whether it is associated with increased peripheral Epo and RBC production.

METHODS

Wistar rats underwent 1-hour transient middle cerebral artery occlusion (MCAO) under mechanical ventilation, followed by reperfusion without further ventilation. Groups of MCAO and sham-operated animals were evaluated at extended times after reperfusion for assessment of arterial blood gases, plasma Epo, and complete blood count.

RESULTS

Arterial oxygen saturation was significantly lower in the infarct group between 6 and 24 hours after reperfusion (P=0.0005), and plasma Epo levels were increased 6 hours after reperfusion (P<0.05). RBC counts and hematocrit were transiently increased 2 to 7 days after reperfusion in animals with MCAO compared with sham. Maximal increases were seen at day 7 (22% and 16% increases of RBC count and hematocrit, respectively; P<0.001). In contrast, the white blood cell counts in animals with MCAO decreased by >30% in the same time period.

CONCLUSIONS

Plasma Epo levels, RBC counts, and hematocrit are all increased in response to systemic hypoxia after cerebral ischemia in rats.

A recoil-proton spectrometer based on a p-i-n diode implementing pulse-shape discrimination

A recoil-proton spectrometer was created by coupling a p-i-n diode with a polyethylene converter. The maximum detectable energy, imposed by the thickness of the totally depleted layer, is approximately 6 MeV. The minimum detectable energy is limited by the contribution of secondary electrons generated by photons in the detector assembly. This limit is approximately 1.5 MeV at full-depletion voltage and was decreased using pulse-shape discrimination. The diode was set up in the 'reverse-injection' configuration (i.e. with the N+ layer adjacent to the converter). This configuration provides longer collection times for the electron-hole pairs generated by the recoil-protons. The pulse-shape discrimination was based on the zero-crossing time of bipolar signals from a (CR)2-(RC)2 filter. The detector was characterised using monoenergetic neutrons generated in the Van De Graaff CN accelerator at the INFN-Laboratori Nazionali di Legnaro. The energy limit for discrimination proved to be approximately 900 keV.

Identification of genetic alterations related to chemoresistance in epithelial ovarian cancer

OBJECTIVE

After the completion of primary chemotherapy, the majority of advanced ovarian cancer patients have persistent, chemoresistant disease. Comparative genomic hybridization (CGH) has been used to study genetic alterations that may be responsible for chemoresistance in ovarian cancer. CGH is a useful, genomewide screen but resolution is limited to 5-10 Mb. Recently, quantitative microsatellite analysis (QuMA), a TaqMan-based quantitative PCR technology, has been used for higher resolution of DNA copy number abnormalities. Our goal is to identify specific chromosomal aberrations correlated with platinum resistance.

METHODS

Snap-frozen ovarian tissue samples taken from 22 patients with ovarian cancer between 1994 and 1998 were analyzed. Patients whose ovarian cancer actually demonstrated growth during platinum-combination treatment or no objective evidence of regression following four to six cycles of therapy were considered to have clinically defined platinum-resistant disease. QuMA was carried out at the following loci using the ABI Prism 7700 (TaqMan) instrument with a microsatellite repeat probe: D3S1553, D3S1617, D5S464, D5S630, D6S1581, D6S446, D8S557, D19S208, D20S196, DXS1068. Fisher's exact test, exact logistic regression, and the Cochran-Armitage trend test were used. Because of multiple hypothesis testing, the P values were adjusted with the Bonferroni procedure to limit the familywise error rate to at most 5%.

RESULTS

Of the 22 patients, 12 (54.5%) were platinum-sensitive and 10 (45.5%) were platinum-resistant. When comparing sensitive and resistant patients, no statistically significant difference was noted among stage, grade, histology, and age (P = 0.1292, P = 1.0000, P = 1.0000, P = 1.0000, respectively). In the QuMA analysis, 10 of the 14 (71.4%) patients who had a low copy number of D6S1581 were platinum-resistant, while none of the patients with a normal or high copy number of D6S1581 were platinum-resistant. This was statistically significant when the marker data were treated as either a continuous or a categorical variable (P = 0.0410 and P = 0.0170, respectively). No other loci correlated significantly with platinum resistance.

CONCLUSIONS

D6S1581 was the only genetic marker, of those examined, significantly related to chemoresistance. Patients with a loss of D6S1581 are more likely to be platinum-resistant. Identification of genetic alterations associated with platinum resistance detected by QuMA may contribute to a better understanding of clinical behavior and chemotherapy treatment options for patients.

[Treatment of childhood obesity. Long-term outcome and predictive factors of success in a group of 130 subjects]

BACKGROUND

In the last years the prevalence of childhood obesity has notably increased. The treatment of this condition is very difficult, because of the frequent relapses. The aim of our study was to examine the long-term outcomes of different dietary treatments (1200 or 1400 calories or chetogenic diet, derived from the protein sparing modified fast) in children and adolescents with primary obesity, in order to show factors predictive of the long-term success.

METHODS

A group of 130 obese children previously undergoing a dietary treatment have been re-evaluated after a 3, 5 and 7 years period from the beginning of the diet.

RESULTS

Ninety-seven out of 130 contacted patients (52 males and 45 females; mean age: 16+/-3 years) participated in this study. An overall improvement of the weight indexes has been observed (relative DBMI mean value: -10.5%). About 1/5 of the whole study-group is not overweight anymore. The statistical analysis (ANOVA and multiple regression analysis) showed that the factors positively affecting the long-term outcome were the following: use of chetogenic diet, initial success of the treatment, older age and strong motivation at the beginning of the diet, gender (male) and lack of familiarity for obesity.

CONCLUSIONS

It is important, in the clinical practice, to consider the above factors that can predict the long-term success of the dietary treatment, in order to individualize the therapy.

[Meniscal injuries of the knee. Diagnostic imaging]

Nowadays, treatment of meniscal tears is conservative with removal only of the broken part of meniscus. For this reason, before arthroscopy, the orthopaedic surgeon needs for an accurate preoperative diagnosis that could be obtained with computed tomography (CT) and magnetic resonance (MR). Our purpose is to value the actual role of CT and MR in diagnosis of meniscal tears. We retrospectively evaluated CT and MR images of 128 patients (average age 32 years) who then underwent arthroscopy. On the basis of our findings CT and MR have been shown to be very accurate to detect meniscal tears, even if with both methodics false positives and false negatives are possible. Nevertheless, MR is able to give high resolution multiplanar images without using ionising radiations and is preferable because of its high accuracy in recognising associated lesions of ligaments or articular cartilage.

Posterolateral instability of the elbow

The authors describe a rare case of recurrent posterior post-traumatic subdislocation of the elbow in a male aged 40 years. From a clinical point of view, it is a highly disabling condition, due to lesion of the ulnar portion of the radial collateral ligament. It is produced at minimum degrees of flexion movement in the elbow and depending on the entity of capsuloligamentous injury it may occur with episodes of instability, recurrent subdislocation or recurrent dislocation. Treatment is surgery and capsuloligamentous reconstruction according to the Osborne-Cotteril method, which has allowed for very satisfactory results to be obtained.

A feasibility study of a single event spectrometer based on semiconductor devices

The electronics employed around particle accelerators can be disturbed or damaged because of single event effects (SEE). The most likely effect is the single event upset (SEU) which may affect all memory devices. In the case of high energy accelerators, SEUs are mostly produced by secondary charged particles generated by neutron interactions. The measurement of the energy and the lineal energy distribution of these neutron-induced charged particles was proposed. As a first approach, a commercial p-i-n photodiode was employed. This device was irradiated with thermal and monoenergetic fast neutrons. Some effects limiting the use of such a detector as a SEE spectrometer were observed, giving guidelines for the design of an application specific integrated circuit (ASIC). The possibility of creating a solid state microdosemeter by coupling the ASIC with a tissue-equivalent radiator is discussed. Moreover, the p-i-n photodiode covered with a hydrogenated plastic radiator may be employed as a proton-recoil spectrometer.

A phase I/II study of hypofractionated whole abdominal radiation therapy in patients with chemoresistant ovarian carcinoma: Karnofsky score determines treatment outcome

PURPOSE

Radiation therapy can provide useful palliation in chemorefractory ovarian cancer patients. The purpose of this study was to prospectively study the palliative effect of a hypofractionated radiation treatment regimen. Change in quality-of-life scores (Functional Assessment of Cancer Therapy [FACT], Karnofsky scale), pain score, and tolerance to therapy were also assessed.

METHODS AND MATERIALS

A single-institution Phase I/II trial was initiated in patients with chemoresistant recurrent or progressive ovarian cancer. All patients had symptomatic and measurable intra-abdominal disease. Patients were treated with a single radiation fraction (700 cGy) or two fractions (300 cGy twice a day) to the whole abdomen over 1 day. Quality-of-life scale (FACT G version 2) was assessed at baseline and 1 and 3 months following treatment. Karnofsky scale and pain score were also evaluated in the same time frame.

RESULTS

Sixteen patients were prospectively entered into this protocol between February 1996 and September 1998. Twelve patients received a single 700 cGy fraction and four 300 cGy twice a day. All were heavily pretreated and 9 (56%) had a poor performance status prior to treatment. Symptoms needing palliation included pain (14), ascites (10), and bleeding (2). Symptomatic improvement occurred in all patients with pain (5 complete response [CR] and 7 partial response [PR], all patients with bleeding (CR 2), and two (20%) with ascites. Five patients (31%) had a reduction in lesion size documented radiologically in three. The mean duration of response was 22 weeks in patients with a Karnofsky score >70. Thirteen patients developed transient nausea and vomiting which resolved in 48 hours in all. All patients developed a transient lymphopenia. Thirteen patients completed a follow-up quality-of-life scale. There was an improvement in the physical and functional components of the scale in patients with Karnofsky score of 90-100. There was no improvement in quality of life in patients with Karnofsky score <90 despite symptomatic response. Median survival was 3 months from the date of treatment.

CONCLUSION

Hypofractionated radiation therapy is an effective palliative treatment for end-stage ovarian cancer patients. Karnofsky score can help determine the duration of response and survival for this high-risk population.

Hypoxia-induced transcriptional activation of vascular endothelial growth factor is inhibited by serum

Expression of vascular endothelial growth factor (VEGF) by cultured vascular smooth muscle cells was analyzed. Serum and hypoxia had nearly additive actions on VEGF mRNA expression. The function of the VEGF promoter in smooth muscle cells was analyzed using transient luciferase reporter assays. Serum and hypoxia stimulated expression of luciferase. The presence of hypoxia response element (HRE) was necessary for the hypoxic induction. AP-1 sequences located upstream of HRE and AP-2/Sp-1 sequences located downstream of HRE are not necessary. Hypoxic responses were best observed in serum-deprived cells. They were largely absent in serum-stimulated cells. Serum did not suppress the hypoxic response by interfering with the hypoxia sensor mechanism or with the signaling cascade that leads to the activation of HIF-1. It is concluded that growth-promoting cytokines regulate hypoxic gene induction in smooth muscle cells.

Mammal-specific, ERK-dependent, caldesmon phosphorylation in smooth muscle. Quantitation using novel anti-phosphopeptide antibodies

Extracellular signal-regulated kinases (ERKs) phosphorylate the high molecular mass isoform of the actin-binding protein caldesmon (h-CaD) at two sites (Ser(759) and Ser(789)) during smooth muscle stimulation. To investigate the role of phosphorylation at these sites, antibodies were generated against phosphopeptides analogous to the sequences around Ser(759) and Ser(789). Affinity-purified antibodies were phosho- and sequence-specific. The major site of phosphorylation in h-CaD in porcine carotid arterial muscle strips was at Ser(789); however, the amount of phosphate did not vary appreciably with either KCl or phorbol ester stimulation. Phosphorylation at Ser(759) of h-CaD was almost undetectable (<0.005 mol of phosphate/mol of protein). Moreover, phosphorylation of the low molecular mass isoform of the protein (l-CaD) at the site analogous to Ser(789) was greater in serum-stimulated cultured smooth muscle cells than in serum-starved cells. Serum-stimulated l-CaD phosphorylation was attenuated by the protein kinase inhibitor PD98059. These data 1) identify Ser(789) of h-CaD as the major site of ERK-dependent phosphorylation in carotid arteries; 2) show that the level of phosphorylation at Ser(789) is relatively constant following carotid arterial muscle stimulation, despite an increase in total protein phosphate content; and 3) suggest a functional role for ERK-dependent l-CaD phosphorylation in cell division.

16K human prolactin inhibits vascular endothelial growth factor-induced activation of Ras in capillary endothelial cells

Signaling pathways mediating the antiangiogenic action of 16K human (h)PRL include inhibition of vascular endothelial growth factor (VEGF)-induced activation of the mitogen-activated protein kinases (MAPK). To determine at which step 16K hPRL acts to inhibit VEGF-induced MAPK activation, we assessed more proximal events in the signaling cascade. 16K hPRL treatment blocked VEGF-induced Raf-1 activation as well as its translocation to the plasma membrane. 16K hPRL indirectly increased cAMP levels; however, the blockade of Raf-1 activation was not dependent on the stimulation of cAMP-dependent protein kinase (PKA), but rather on the inhibition of the GTP-bound Ras. The VEGF-induced tyrosine phosphorylation of the VEGF receptor, Flk-1, and its association with the Shc/Grb2/Ras-GAP (guanosine triphosphatase-activating protein) complex were unaffected by 16K hPRL treatment. In contrast, 16K hPRL prevented the VEGF-induced phosphorylation and dissociation of Sos from Grb2 at 5 min, consistent with inhibition by 16K hPRL of the MEK/MAPK feedback on Sos. The inhibition of Ras activation was paralleled by the increased phosphorylation of 120 kDa proteins comigrating with Ras-GAP. Taken together, these findings show that 16K hPRL inhibits the VEGF-induced Ras activation; this antagonism represents a novel and potentially important mechanism for the control of angiogenesis.

Opposing actions of intact and N-terminal fragments of the human prolactin/growth hormone family members on angiogenesis: an efficient mechanism for the regulation of angiogenesis

Angiogenesis, the process of development of a new microvasculature, is regulated by a balance of positive and negative factors. We show both in vivo and in vitro that the members of the human prolactin/growth hormone family, i.e., human prolactin, human growth hormone, human placental lactogen, and human growth hormone variant are angiogenic whereas their respective 16-kDa N-terminal fragments are antiangiogenic. The opposite actions are regulated in part via activation or inhibition of mitogen-activated protein kinase signaling pathway. In addition, the N-terminal fragments stimulate expression of type 1 plasminogen activator inhibitor whereas the intact molecules have no effect, an observation consistent with the fragments acting via separate receptors. The concept that a single molecule encodes both angiogenic and antiangiogenic peptides represents an efficient model for regulating the balance of positive and negative factors controlling angiogenesis. This hypothesis has potential physiological importance for the control of the vascular connection between the fetal and maternal circulations in the placenta, where human prolactin, human placental lactogen, and human growth hormone variant are expressed.

[Hemophagocytic syndrome in a patient with anemia and liver pathology]

A case of 62-year old female with history of alcohol abuse, anemia and hepatopathy is reported. The bone marrow aspiration showed the increase of the histiocytes without morphological alteration but with increased hemophagocytic activity compatible with hemophagocytic syndrome. The case is reported because, beyond of the diagnostic guideline, the hemophagocytic syndrome can be considered still a morphological diagnosis.

Osteoid osteoma of the vertebral body: a clinical case

The authors describe a case of lumbar vertebral osteoid osteoma localized in the body of L5 characterized by a very subtle clinical onset (limping as a result of poor positioning of the hip), and by a clinical course where pain was totally absent.

[Probiotics in childhood]

The Probiotics (Lactic acid bacteria) represent a nutritional live microbial supplement that positively affects host by enhancing the microbial balance. A survey is made of the most relevant studies concerning the use of probiotics in the prevention and treatment of infantile acute diarrhoea (by rotavirus or other agents), pseudomembranous colitis, hospital-acquired and antibiotic-associated diarrhoeas. Although the probiotics mechanism of action is not yet completely understood, it has been hypothesized that they exert an inhibitory effect on the intestinal inflammation by immune response modulation. Due to this property, the use of probiotics has therefore been suggested in other severe diseases such as chronic inflammatory bowel diseases, rheumatoid arthritis, food allergy, atopic dermatitis and as immunoadjuvant for oral vaccines.

Regulation of vascular endothelial growth factor expression by cAMP in rat aortic smooth muscle cells

Vascular endothelial growth factor (VEGF) is an endothelial cell mitogen which stimulates angiogenesis. VEGF is regulated by multiple factors such as hypoxia, phorbol esters, and growth factors. However, data concerning the expression of VEGF in the different vascular cell types and its regulation by cAMP are not available. In the present study, we have investigated the effect of adenylate cyclase activation on VEGF mRNA expression in rat vascular cells in primary culture. Basal VEGF expression is greater in smooth muscle cells than in endothelial cells and fibroblasts. A 4-h treatment with forskolin (10(-5) M) induced a 2-fold stimulation of VEGF mRNA expression in smooth muscle cells and fibroblasts, but, in contrast, did not affect VEGF expression in endothelial cells. In smooth muscle cells, a pharmacologically induced increase in intracellular cAMP levels using iloprost or isoprenaline led to a rise in VEGF mRNA expression comparable to that induced by forskolin. Adenosine, which increases cAMP levels in smooth muscle cells, also increases VEGF expression. Moreover, the 2.2-fold stimulation of VEGF expression by adenosine was enhanced following a cotreatment with cobalt chloride (a hypoxia miming agent). The observed additive effect (4.3-fold increase) suggests that these two factors, hypoxia and adenosine, regulate VEGF mRNA expression in smooth muscle cells by independent mechanisms.

Hyde's prurigo nodularis and chronic HCV hepatitis

The authors describe a woman with chronic active hepatitis, Hyde's prurigo nodularis and hepatitis C virus infection. The association of these three pathologies and their parallel evolution during treatment suggest a possible pathogenic link between the chronic hepatitis C virus infection and the skin disease.