The role of lifestyle changing to improve the semen quality in patients with varicocele

AIM

To evaluate the recovery of semen quality in patients with high grade varicocele without hypotrophy and abnormal semen analysis using a simple lifestyle changing protocol.

METHODS

Fifty-two patients were eligible for this study. Two semen sample were collected at baseline and other two after treatment.

PROTOCOL

patients had to stop or decrease the number of cigarette per day, reduce the coffee and alcohol consumption, introduce fruits and vegetables in the daily diet and have a normal sexual activity with an abstinence of tree days before semen collection. All the variables and the semen parameters were evaluated and correlated between responders and non-responders.

RESULTS

Forty patients (76%) had an improvement of semen quality showing a normal semen analysis following the WHO criteria. The other 12 patients had an improvement of the semen quality but without statistical differences. Smokers and drinkers (for both coffee and alcohol) had lower sperm volume, lower sperm motility and vitality when compared to the others.

CONCLUSIONS

The analysis of data collected by the spermiograms showed that semen quality could benefit from lifestyle changing. This finding is important for the management of patients with varicocele, suggesting that lifestyle changing could avoid surgery.

Maize food allergy: a double-blind placebo-controlled study

BACKGROUND

Maize allergy is not very common especially in Europe. The number of studies that address IgE mediated maize allergy is all too few.

OBJECTIVE

Evaluate subjects with a history of maize allergy by double-blind, placebo-controlled food challenge; identify the spectrum of symptoms manifested during challenge; determine the lowest provocation dose (PD) during challenge; determine the performance characteristics of maize skin prick test and specific IgE.

METHODS

Twenty-seven patients with a history of maize allergy were enrolled to be evaluated by skin test, specific IgE and double-blind placebo-controlled maize challenge.

RESULTS

Forty-eight percent of the patients were challenge positive. PD range was 0.1-25 g. Fifty-four percent of the maize allergic subjects had a PD that was < or = 2.5 g; two subjects reacted to 100 mg of maize. Comparison of maize specific IgE levels and skin test results to the challenge results revealed the following (specific IgE level/skin testing): sensitivity 1.00/0.846, specificity 0.077/0.384, positive predictive value 0.520/0.579, and negative predictive value 1.00/0.714.

CONCLUSION

Maize is a cause of IgE-mediated allergic reactions to foods in adults and children. Nearly half of the subjects recruited were confirmed by challenge to be allergic to maize. Twenty-three percent of the positive challenge patients manifested symptoms that involved two organ systems, thus fulfilling the criteria for maize induced anaphylaxis. Maize is allergenic and can pose a risk for symptomatic food allergy at a dose of 100 mg.

First steps towards systems radiation biology studies concerned with DNA and chromosome structure within living cells

For the understanding of radiation action on biological systems like cellular macromolecules (e.g., DNA in its higher structures) a synergistic approach of experiments and quantitative modelling of working hypotheses is necessary. Further on, the influence on calculated results of certain assumptions in such working hypotheses must critically be evaluated. In the present work, this issue is highlighted in two aspects for the case of DNA damage in single cells. First, yields of double-strand breaks and frequency distributions of DNA fragment lengths after ion irradiation were calculated using different assumptions on the DNA target model. Compared to a former target model now a moderate effect due to the inclusion of a spherical chromatin domain model has been found. Second, the influence of assumptions on particular geometric chromosome models on calculated chromosome aberration data is illustrated with two target-modelling approaches for this end point.

Botryoid rhabdomyosarcoma of the biliary tract in children: a unique case report

Rhabdomyosarcoma (RMS) is the most common tumour of the biliary tree in childhood. In children, it is a rare lesion, accounting for about 1% of all RMS. Hepatobiliary botryoid RMS is a disease affecting young children at a median age of about 3 years. In literature, the radiological findings of hepatobiliary RMS have been described in small series and some case reports. In this case report, we present a rare case of RMS of the extrahepatic biliary tree initially diagnosed as a choledochal cyst.

Radiochromic Films for Improved Evaluation of Patient Dose in Liver Interventions

PURPOSE

To investigate a method for evaluation of the maximum skin dose (MSD) of radiation in patients undergoing interventional radiology procedures in the liver.

MATERIALS AND METHODS

Transarterial chemoembolization, transarterial embolization, portal vein embolization, and biliary interventions were the procedures considered in this study. Ninety procedures in 70 patients were studied. The complexity of the biliary interventions was taken into account during the analysis. The MSD was measured with use of GAF chromic XR type R films, whereas the dose-area product (DAP) was measured by a transmission chamber.

RESULTS

The MSD was measured in a group of 19 patients. The coefficient of the interpolation line between the skin dose and the DAP (0.0051 cm(-2)) was determined. An approximated value of MSD from the DAP for the remaining 71 procedures was estimated by means of an interpolation line. The mean MSD in the endovascular procedures was 4.4 Gy; for the three different levels of complexity of the biliary procedures, the mean MSDs were 0.4, 1.2, and 3 Gy, respectively.

CONCLUSIONS

Radiochromic films are an easy-to-use and efficient method for measuring skin entrance radiation dose and have the advantage of providing information on the MSD as well as the distribution of radiation to the skin. In light of these results, the authors suggest recording the dose for biliary and endovascular procedures as indicated by the International Commission on Radiological Protection and the United States Food and Drug Administration.

Gamma ray-induced bystander effect in tumour glioblastoma cells: a specific study on cell survival, cytokine release and cytokine receptors

Recent experimental evidence has challenged the paradigm according to which radiation traversal through the nucleus of a cell is a prerequisite for producing genetic changes or biological responses. Thus, unexposed cells in the vicinity of directly irradiated cells or recipient cells of medium from irradiated cultures can also be affected. The aim of the present study was to evaluate, by means of the medium transfer technique, whether interleukin-8 and its receptor (CXCR1) may play a role in the bystander effect after gamma irradiation of T98G cells in vitro. In fact the cell specificity in inducing the bystander effect and in receiving the secreted signals that has been described suggests that not only the ability to release the cytokines but also the receptor profiles are likely to modulate the cell responses and the final outcome. The dose and time dependence of the cytokine release into the medium, quantified using an enzyme linked immunosorbent assay, showed that radiation causes alteration in the release of interleukin-8 from exposed cells in a dose-independent but time-dependent manner. The relative receptor expression was also affected in exposed and bystander cells.

Human exposure to space radiation: role of primary and secondary particles

Human exposure to space radiation implies two kinds of risk, both stochastic and deterministic. Shielding optimisation therefore represents a crucial goal for long-term missions, especially in deep space. In this context, the use of radiation transport codes coupled with anthropomorphic phantoms allows to simulate typical radiation exposures for astronauts behind different shielding, and to calculate doses to different organs. In this work, the FLUKA Monte Carlo code and two phantoms, a mathematical model and a voxel model, were used, taking the Galactic Cosmic Rays (GCR) spectra from the model of Badhwar and O'Neill. The time integral spectral proton fluence of the August 1972 Solar Particle Event (SPE) was represented by an exponential function. For each aluminium shield thickness, besides total doses the contributions from primary and secondary particles for different organs and tissues were calculated separately. More specifically, organ-averaged absorbed doses, dose equivalents and a form of 'biological dose', defined on the basis of initial (clustered) DNA damage, were calculated. As expected, the SPE doses dramatically decreased with increasing shielding, and doses in internal organs were lower than in skin. The contribution of secondary particles to SPE doses was almost negligible; however it is of note that, at high shielding (10 g cm(-2)), most of the secondaries are neutrons. GCR organ doses remained roughly constant with increasing Al shielding. In contrast to SPE results, for the case of cosmic rays, secondary particles accounted for a significant fraction of the total dose.

Modelling radiation-induced bystander effect and cellular communication

In the last 10 years evidence has accumulated on the so-called radiation-induced 'non-targeted effects' and in particular on bystander effects, consisting of damage induction in non-irradiated cells most likely following the release of soluble factors by the irradiated ones. These phenomena were observed for different biological endpoints, both lethal and non-lethal for the cell. Although the underlying mechanisms are largely unknown, it is now widely recognised that two types of cellular communication (i.e. via gap junctions and/or release of molecular messengers into the extracellular environment) play a pivotal role. Furthermore, the effects can be significantly modulated by parameters such as cell type and cell-cycle stage, cell density, time after irradiation etc. Theoretical models and simulation codes can be of help to improve our knowledge of the mechanisms, as well as to investigate the possible role of these effects in determining deviations from the linear relationship between dose and risk which is generally applied in radiation protection. In this paper three models, including an approach under development at the University of Pavia, will be presented in detail. The focus will be on the various adopted assumptions, together with their implications in terms of non-targeted radiobiological damage and, more generally, low-dose radiation risk. Comparisons with experimental data will also be discussed.

Simulation of light ion induced DNA damage patterns

The biophysical simulation code PARTRAC was extended by a module to handle ions heavier than alpha particles. Cross sections for ion-electron interactions were taken from He(++) ions of the same velocity and scaled by Z(eff(2))/4. Calculated linear energy transfer values, radial dose distributions and secondary electron spectra were found in agreement with experimental results. DNA damage due to irradiation of human fibroblast cells by several light ions from H to S was calculated for various energies complemented by 220 kV(p) X rays as reference radiation. With increasing linear energy transfer, the calculated total yield of double-strand breaks per dose showed saturation behaviour at about twice the value for reference radiation. When data analysis methods for experimental double-strand break yield determination were applied to the simulated DNA damage patterns, the two data sets were found in accord. The calculated patterns of DNA damage clusters were analysed on local and regional scale finding regional clusters in closer correlation to experimental cell inactivation data.

Role of DNA/chromatin organisation and scavenging capacity in USX- and proton- induced DNA damage

DNA higher-order structures and (non-histonic) *;OH radical scavengers have well known protective effects in the induction of single- and double-strand breaks by ionising radiation. In a previous work, such protective roles have been quantified for gamma radiation (Valota et al., Int. J. Radiat. Biol. 79, 2003). As a starting base for the simulations, we used the PARTRAC Monte Carlo code, developed within a collaboration involving the University of Pavia and the GSF institute. The code can reproduce the track structure of photons, electrons, protons and heavier ions in liquid water, and it can simulate the DNA content of a human cell at different organisation levels, based on an atom-by-atom approach. In this work we extended the calculations to Ultra-Soft X rays (USX) and protons, separately analysing the effects of different radiation types on various DNA structures (i.e. linear DNA, SV40 'minichromosomes' and compact chromatin) as a function of the *OH scavenging capacity (SC). Both for USX and protons, the calculated damage yields decreased by increasing the SC for the three considered target types. Such decrease can be ascribed to the competition between the reactions *OH-DNA and *OH-scavenger, which becomes more and more likely by increasing the SC. Furthermore, linear DNA was found to be more radiosensitive than SV40 'minichromosomes', which in turn were more radiosensitive than compact chromatin, which is protected by histones. Comparisons with experimental data by Fulford et al. (Int. J. Radiat. Biol. 77, 2001) relative to USX irradiation showed very good agreement. The dependence of the modulating role played by DNA organisation and scavenging capacity on radiation quality is presented and discussed.

A Model of Chromosome Aberration Induction: Applications to Space Research

A mechanistic model and Monte Carlo code simulating chromosome aberration induction in human lymphocytes is presented. The model is based on the assumption that aberrations arise from clustered DNA lesions and that only the free ends of clustered lesions created in neighboring chromosome territories or in the same territory can join and produce exchanges. The lesions are distributed in the cell nucleus according to the radiation track structure. Interphase chromosome territories are modeled as compact intranuclear regions with volumes proportional to the chromosome DNA contents. Both Giemsa staining and FISH painting can be simulated, and background aberrations can be taken into account. The good agreement with in vitro data provides validation of the model in terms of both the assumptions adopted and the simulation techniques. As an application in the field of space research, the model predictions were compared with aberration yields measured among crew members of long-term missions on board Mir and ISS, assuming an average radiation quality factor of 2.4. The agreement obtained also validated the model for in vivo exposure scenarios and suggested possible applications to the prediction of other relevant aberrations, typically translocations.

The FLUKA code: new developments and application to 1 GeV/n iron beams

The modeling of ion transport and interactions in matter is a subject of growing interest, driven by the continuous increase of possible application fields. These include hadron therapy, dosimetry, and space missions, but there are also several issues involving fundamental research, accelerator physics, and cosmic ray physics, where a reliable description of heavy ion induced cascades is important. In the present work, the capabilities of the FLUKA code for ion beams will be briefly recalled and some recent developments presented. Applications of the code to the simulation of therapeutic carbon, nitrogen and oxygen ion beams, and of iron beams, which are of direct interest for space mission related experiments, will be also presented together with interesting consideration relative to the evaluation of dosimetric quantities. Both applications involve ion beams in the AGeV range.

The application of FLUKA to dosimetry and radiation therapy

The FLUKA Monte Carlo code has been evolving over the last several decades and is now widely used for radiation shielding calculations. In order to facilitate the use of FLUKA in dosimetry and therapy applications, supporting software has been developed to allow the direct conversion of the output files from standard CT-scans directly into a voxel geometry for transport within FLUKA. Since the CT-scan information essentially contains only the electron density information over the scanned volume, one needs the specific compositions for each voxel individually. We present here the results of a simple algorithm to assign tissues in the human body to one of four categories: soft-tissue, hard-bone, trabecular-bone and porous-lung. In addition, we explore the problem of the pathlength distributions in porous media such as trabecular bone. A mechanism will be implemented within FLUKA to allow for variable multipal fixed density materials to accommodate the pathlength distributions discovered.

Role of DNA organisation and environmental scavenging capacity in the evolution of radiobiological damage: models and simulations

BACKGROUND AND PURPOSE

Theoretical models and Monte Carlo simulations were developed, aimed to investigate the role played by the organisation of interphase DNA and the environmental scavenging capacity conditions in the induction of radiobiological damage.

METHODS

The induction of single- and double-strand breaks by gamma rays impinging on different DNA structures (e.g. linear DNA, SV40 minichromosome and cellular DNA) was simulated as a function of the environment scavenging capacity. Furthermore, yields of chromosome aberrations (CA) induced by gamma rays and light ions were simulated with a purposely developed MC code that explicitly takes into account the DNA higher-order organisation as chromosome territories.

RESULTS AND CONCLUSIONS

Simulations performed with the PARTRAC code allowed quantification of the dependence of dsb and ssb both on the target structure, and on the scavenging capacity. The results relative to CA showed the importance of DNA damage complexity (nanometre scale) and interphase chromosome domains (micrometre scale) in the process of aberration formation. Very good agreement was found between the model predictions on ssb, dsb and CA and available experimental data.

A model of chromosome aberration induction and chronic myeloid leukaemia incidence at low doses

Some chromosome aberration types, generally translocations, are correlated with specific cancers. An example is provided by chronic myeloid leukemia (CML) cells, most of which carry a translocation involving the ABL gene on chromosome 9 and the BCR gene on chromosome 22. The hypothesis of a causal relationship between CML and the chimeric protein product of the BCR-ABL translocation has recently received strong support. In this framework, a mechanistic model and Monte-Carlo code simulating radiation-induced chromosome aberrations in human lymphocytes will be presented. The current version of the model can predict dose-response curves for the main aberration types following acute irradiation with gamma rays and light ions of different energies. The model is based on the assumption that only clustered DNA lesions can lead to aberrations and that only lesion free ends in neighbouring chromosome territories can join and form exchanges. Such lesions are distributed within the cell nucleus according to the radiation track structure, i.e. randomly for low-LET radiation and along straight lines for high-LET light ions. Interphase chromosome territories are explicitly simulated and background aberrations are taken into account. Very good agreement was found with experimental data taken from the literature that provided a further validation of the model. As an application, yields of BCR-ABL translocations were calculated. Preliminary results led to a CML induction dose-response that is approximately quadratic below 0.1 Gy and essentially linear at higher doses up to 1 Gy. The numerical values obtained for the probability of CML induction are consistent with values obtained by other groups with different approaches.

Models of chromosome aberration induction: an example based on radiation track structure

A few examples of models of chromosome aberration induction are summarised and discussed on the basis of the three main theories of aberration formation, that is "breakage-and-reunion", "exchange" and "one-hit". A model and code developed at the Universities of Milan and Pavia is then presented in detail. The model provides dose-response curves for different aberration types (dicentrics, translocations, rings, complex exchanges and deletions) induced in human lymphocytes by gamma rays, protons and alpha particles of different energies, both as monochromatic fields and as mixed fields. The main assumptions are that only clustered - and thus severe - DNA breaks ("Complex Lesions", CL) can participate in the production of aberrations, and that only break free ends in neighbouring chromosome territories can interact and form exchanges. The yields of CLs induced by the various radiation types of interest are taken from a previous modelling work. These lesions are distributed within a sphere representing the cell nucleus according to the radiation track structure, e.g. randomly for gamma rays and along straight lines for light ions. Interphase chromosome territories are explicitly simulated and configurations are obtained in which each chromosome occupies an intranuclear domain with volume proportional to its DNA content. In order to allow direct comparisons with experimental data, small fragments can be neglected since usually they cannot be detected in experiments. The presence of a background level of aberrations is also taken into account. The results of the simulations are in good agreement with experimental dose-response curves available in the literature, that provides a validation of the model both in terms of the adopted assumptions and in terms of the simulation techniques. To address the question of "true" incompleteness, simulations were also run in which all fragments were assumed to be visible.

Complete pancreatic ectopia in a gastric duplication cyst: a case report and review of the literature

Ectopic tissue can be histologically detected in gastric duplication cysts. The authors describe the case of a complete pancreatic ectopia in a prenatally diagnosed symptomatic gastric duplication cyst in a 6-month-old male infant. Surgical removal of the cystic formation was curative. In view of the rarity of the lesion, a full clinical and diagnostic classification of the condition proved possible only after radical surgical resection and histological examination. Immunohistochemical investigation enabled us to detect the complete pancreatic ectopia.

[Primary ad secondary gastro-esophageal reflux in pediatric age]

AIM

This study takes into consideration children traited for: a) "primary" gastro-esophageal reflux (GER); b) GER "secondary" to delayed gastric emptying; c) some congenital anomalies which can cause or favour GER in pediatric age.

METHODS

During 2002, 21 infants or children operated on for "primary" or "secondary" GER and 62 patients operated on for esophageal atresia, diaphragmatic hernia or abdominal wall defect were followed-up to evaluate the frequency and the course of post-operative GER.

RESULTS

Patients with "primary" GER had 14% relapses after partial or total fundoplication; all patients with "secondary" GER submitted to fundoplication, usually associated to pyloroplasty, had 0% relapses. One child, after Bianchi's operation, developed an erosive gastritis. Variable degrees of GER developed in 43% of patients operated on for esophageal atresia, in 25% for congenital diaphragmatic hernia and in 0% for abdominal wall defect. In 90% of GER occurred after treatment of esophageal atresia and in 100% of diaphragmatic hernia (predominantely "acquired") an exclusively medical therapy was successfully performed.

CONCLUSION

The conclusion is drawn that: a) the relatively high percentage of relapses after fundoplication in "primary" GER may be related to an incorrect classification of a few number of cases ("secondary" GER considered--and treated--like "primary" GER in the '70s and '80s years?); b) fundoplication associated to a best gastric-emptying operation (pyloroplasty) may lead to excellent results in secondary GER; c) esophageal atresia and congenital diaphragmatic hernia (not including the abdominal wall defects) can cause GER in most cases responsive to simple medical therapy.

The FLUKA code for space applications: recent developments

The FLUKA Monte Carlo transport code is widely used for fundamental research, radioprotection and dosimetry, hybrid nuclear energy system and cosmic ray calculations. The validity of its physical models has been benchmarked against a variety of experimental data over a wide range of energies, ranging from accelerator data to cosmic ray showers in the earth atmosphere. The code is presently undergoing several developments in order to better fit the needs of space applications. The generation of particle spectra according to up-to-date cosmic ray data as well as the effect of the solar and geomagnetic modulation have been implemented and already successfully applied to a variety of problems. The implementation of suitable models for heavy ion nuclear interactions has reached an operational stage. At medium/high energy FLUKA is using the DPMJET model. The major task of incorporating heavy ion interactions from a few GeV/n down to the threshold for inelastic collisions is also progressing and promising results have been obtained using a modified version of the RQMD-2.4 code. This interim solution is now fully operational, while waiting for the development of new models based on the FLUKA hadron-nucleus interaction code, a newly developed QMD code, and the implementation of the Boltzmann master equation theory for low energy ion interactions.

Role of shielding in modulating the effects of solar particle events: Monte Carlo calculation of absorbed dose and DNA complex lesions in different organs

Distributions of absorbed dose and DNA clustered damage yields in various organs and tissues following the October 1989 solar particle event (SPE) were calculated by coupling the FLUKA Monte Carlo transport code with two anthropomorphic phantoms (a mathematical model and a voxel model), with the main aim of quantifying the role of the shielding features in modulating organ doses. The phantoms, which were assumed to be in deep space, were inserted into a shielding box of variable thickness and material and were irradiated with the proton spectra of the October 1989 event. Average numbers of DNA lesions per cell in different organs were calculated by adopting a technique already tested in previous works, consisting of integrating into "condensed-history" Monte Carlo transport codes--such as FLUKA--yields of radiobiological damage, either calculated with "event-by-event" track structure simulations, or taken from experimental works available in the literature. More specifically, the yields of "Complex Lesions" (or "CL", defined and calculated as a clustered DNA damage in a previous work) per unit dose and DNA mass (CL Gy-1 Da-1) due to the various beam components, including those derived from nuclear interactions with the shielding and the human body, were integrated in FLUKA. This provided spatial distributions of CL/cell yields in different organs, as well as distributions of absorbed doses. The contributions of primary protons and secondary hadrons were calculated separately, and the simulations were repeated for values of Al shielding thickness ranging between 1 and 20 g/cm2. Slight differences were found between the two phantom types. Skin and eye lenses were found to receive larger doses with respect to internal organs; however, shielding was more effective for skin and lenses. Secondary particles arising from nuclear interactions were found to have a minor role, although their relative contribution was found to be larger for the Complex Lesions than for the absorbed dose, due to their higher LET and thus higher biological effectiveness.

Modelling study on the protective role of OH radical scavengers and DNA higher-order structures in induction of single- and double-strand break by gamma-radiation

PURPOSE

To quantify the protective effects of (non-histonic) OH-radical scavengers and DNA higher-order structures in induction of single- (ssbs) and double-strand breaks (dsbs) by gamma-rays.

MATERIALS AND METHODS

Spatial distributions of energy depositions by gamma-rays in liquid water were modelled with the track structure modules of the biophysical simulation code PARTRAC. Such distributions were superimposed on different DNA structure models (e.g. linear DNA, SV40 'minichromosomes' and compact chromatin), and direct energy depositions in the sugar-phosphate were considered as potential (direct) ssbs. The diffusion and interaction of the main chemical species produced in liquid water radiolysis were explicitly simulated, and reactions of *OH with the sugar-phosphate were considered as potential (indirect) ssbs. Two ssb on opposite DNA strands within 10 base pairs were considered as one dsb. Yields of ssb and dsb Gy(-1) Dalton(-1) in different DNA target structures were calculated as a function of the *OH mean lifetime, whose inverse value was taken as representative of the scavenging capacity of the DNA environment.

RESULTS AND CONCLUSIONS

A further validation of the models implemented in the PARTRAC code has been provided, thus allowing a better understanding of the mechanisms underlying DNA damage. More specifically, the protection due to *OH scavengers was separately quantified with respect to that due to histones and chromatin folding, which could be 'switched off' in the simulations. As expected, for a given value of the environment scavenging capacity, linear DNA was more susceptible to strand breakage than SV40 minichromosomes, which in turn showed higher damage yields with respect to cellular DNA due to the larger accessibility offered to *OH. Furthermore, by increasing the scavenging capacity, the break yields decreased in all structures and tended to coincide with direct damage yields. Very good agreement was found with available experimental data. Comparisons with data on 'nucleoid' DNA (i.e. unfolded and histone-depleted DNA) also suggested that the experimental procedures used to obtain such structures might lower the environment scavenging capacity owing to the loss of cellular scavengers.