Typical values of z-resolution for different Digital Breast Tomosynthesis systems evaluated in a multicenter study.

PURPOSE: The aim of the present study, conducted by a working group of the Italian Association of Medical Physics (AIFM), was to define typical z-resolution values for different digital breast tomosynthesis (DBT) models to be used as a reference for quality control (QC). Currently, there are no typical values published in internationally agreed QC protocols. METHODS: To characterize the z-resolution of the DBT models, the full width at half maximum (FWHM) of the artifact spread function (ASF), a technical parameter that quantifies the signal intensity of a detail along reconstructed planes, was analyzed. Five different commercial phantoms, CIRS Model 011, CIRS Model 015, Modular DBT phantom, Pixmam 3-D, and Tomophan, were evaluated on reconstructed DBT images and 82 DBT systems (6 vendors, 9 models) in use at 39 centers in Italy were involved. RESULTS: The ASF was found to be dependent on the detail size, the DBT angular acquisition range, the reconstruction algorithm and applied image processing. In particular, a progressively greater signal spread was observed as the detail size increased and the acquisition angle decreased. However, a clear correlation between signal spread and angular range width was not observed due to the different signal reconstruction and image processing strategies implemented in the algorithms developed by the vendors studied. CONCLUSIONS: The analysis led to the identification of typical z-resolution values for different DBT model-phantom configurations that could be used as a reference during a QC program.

Possible effects of clustering structure in the competition between fast emission processes and compound nucleus decay / Posibles efectos de estructura de agrupamiento en la competencia entre los procesos de emisión rápida y desintegración del núcleo compuesto

Abstract The attention to nuclear clustering has been renewed due to the study of weakly bound nuclei at the drip lines. In particular, clustering structural properties in medium-mass systems have been studied by looking at the competition between the evaporation and pre-equilibrium particle emission in central collisions. Although for light nuclei at an excitation energy close to the particle separation value there are experimental evidence of such structure effects, this is still not the case for heavier systems since the determination of pre-formed clusters within nuclear matter is less obvious. Two systems, leading to the same 81Rb* compound nucleus, have been studied at the same beam velocity 16 AMeV: 16O + 65Cu and 19F + 62Ni. The experiment has been performed using the GARFIELD + RCo detection system installed at the Legnaro National Laboratories.Light charged particles energy distributions and multiplicities have been compared with different statistical and dynamical model calculations. From the first comparison between the two systems a difference in the fast α-decay channel has been evidenced, which can be related to the difference in the projectile structure. Recent data analysis results and comparisons with model calculations are presented in this contribution.

Resumen La atención a la agrupación nuclear se ha renovado debido al estudio de núcleos débilmente unidos en las líneas de goteo. En particular, se han estudiado las propiedades estructurales del agrupamiento en sistemas de masa media al observar la competencia entre la evaporación y la emisión de partículas de preequilibrio en colisiones centrales. Aunque para núcleos ligeros a una energía de excitación cercana al valor de separación de la partícula hay evidencia experimental de tales efectos de estructura, este no es el caso para sistemas más pesados ya que la determinación de agrupamientos preformados dentro de la materia nuclear es menos obvia. Se han estudiado dos sistemas, que conducen al mismo núcleo compuesto 81Rb *, a la misma velocidad de haz 16 AMeV: 16O + 65Cu y 19F + 62Ni. El experimento se ha realizado utilizando el sistema de detección GARFIELD + RCo instalado en los Laboratorios Nacionales Legnaro. Las distribuciones de energía y las multiplicidades de partículas de carga ligera se han comparado con diferentes cálculos de modelos estadísticos y dinámicos. Desde la primera comparación entre los dos sistemas, se ha evidenciado una diferencia en el canal de desintegración α rápida, que se puede relacionar con la diferencia en la estructura del proyectil. En esta contribución se presentan los resultados del análisis de datos recientes y las comparaciones con los cálculos del modelo.

Turnover do carbono em sangue e plasma, nas fases crescimento e postura, de codornas japonesas (Coturnix coturnix japonica) / Turnover of carbon in blood and plasma, growth stages and posture, japanese quails (Coturnix coturnix japonica)

O estudo objetivou avaliar o turnover do 13C no sangue e plasma de codornas japonesas utilizando a técnica de isótopos estáveis, para a obtenção do patamar de equilíbrio isotópico que servirá de fundamento para estudos de rastreabilidade. Foram utilizadas 300 aves durante o período experimental de 1-42 e 49-97 dias de idade. Os tratamentos da primeira fase foram constituídos de dietas à base de arroz (C3), contendo ou não farinha de carne e ossos bovinos e um com dieta à base de milho (C4). Nessa primeira fase foi analisado o turnover do sinal isotópico do matrizeiro à base de dietas C4 para dietas à base de C3, como também as diferenças isotópicas das dietas contendo ou não farinha de origem animal. Na segunda fase houve uma substituição de dietas, ou seja, as aves no tratamento C4 da primeira fase passaram a consumir dieta C3, e o tratamento que antes consumia dieta C3 passou para dieta C4. Para determinar a taxa de turnover e o percentual estimado de participação da farinha na composição do material coletado, foi empregado o modelo de diluição isotópica utilizando valores do δ13C. A comparação entre as meias-vidas do sangue e plasma da primeira fase revelou o enriquecimento do δ13C na dieta; já na segunda fase foi possível observar as velocidades de incorporação após a troca das dietas...

The study aimed to evaluate the turnover of 13C in the blood and plasma of Japanese quail using the technique of stable isotopes to obtain the level of isotopic equilibrium that will be the foundation for studies of traceability. A total of 300 birds during the experimental period of 1-42 and 49-97 days of age. The first phase of the treatments consisted of diets based on rice (C3), with or without meat and beef bones and a diet based on corn (C4). This was first examined the turnover signal farm matrix isotope-based diets based diets C4 to C3, as well as isotopic differences of diets with or without animal meal In the second stage there was a substitution of diets, or C4 treatment of the first stage passes to consume C3-based diet than before treatment and diet consumed C3 to C4 diet. To determine the turnover rate and the estimated percentage of participation of flour in the composition of the collected material was used isotope dilution model using δ13C values. A comparison of the half-lives of blood and plasma from the first phase discloses the enrichment of dietary δ 13C, in the second phase was observed after incorporation speeds exchange diets...

Comparison of ultrasound and magnetic resonance imaging in the prenatal diagnosis of Apert syndrome: report of a case.

BACKGROUND: The birth prevalence of Apert syndrome is estimated at 1:64,500 and accounts for about 4.5 % of all craniosynostosis with a male/female ratio equal to 1:1. It is associated to allelic mutations in the fibroblast growth factor receptor 2 (FGFR2) gene. Majority cases are sporadic. Prenatal ultrasound diagnosis is based on the detection of abnormal cranial shape, midfacial hypoplasia and bilateral syndactyly of hands and feet, hypertelorism, and exorbitism. Other abnormalities includes central nervous system anomalies, congenital heart diseases, cleft palate, and urogenital diseases. CASE REPORT: A 37-year-old Caucasian woman, gravida 2, para 1, was referred to our center of Prenatal Diagnosis for routine ultrasound at 21 weeks of gestation. We detected irregular head shape, dolicocephaly, prominent forehead, bilateral mild ventriculomegaly, suspicion of partial agenesis of the corpus callosum, hypertelorism, and midfacial hypoplasia, with a depressed nasal bridge and syndactyly, prompting a suspicion for Apert syndrome. Magnetic resonance excluded agenesis of corpus callosum and confirmed bilateral mild ventriculomegaly. A follow-up ultrasound, performed at 23 weeks, confirmed the anomalies showed in the previous scan. An amniocentesis was performed. The results showed a normal male karyotype, while the molecular genetic test confirmed a mutation in FGFR2 gene. Fetus macroscopic analysis showed compatible features. CONCLUSIONS: Our case underlines the complementary role of ultrasound and magnetic resonance imaging in the early prenatal diagnosis of Apert syndrome.

Matrix array transducer for the examination of fetal heart.

The X6-1 xmatrix array transducer allows a completely new approach to the diagnostic ultrasound: it permits visualization of fetal heart in real time, without the need for gating, and it is unaffected by motion artefacts. It is obtained in real time, without any spatial reconstruction. The authors compared this technology with the traditional one in two case reports: a diagnostic doubt of small muscular ventricular septal defect was solved using this new technique; a diagnosis of complete atrioventricular septal defect was confirmed. Three-dimensional real-time imaging would seem very precise in the study of fetal heart: the defects were fully visualized from any angulations. This new technology is promising but from the authors' limited experience, there is no evidence to use it in routine practice. It should be very useful to commence a prospective study on fetuses at risk while testing the superiority of this technique.

A case of uterine rupture in mid-trimester spontaneous abortion: a complication of gemeprost vaginal administration.

The only prostaglandin analogue licensed in Italy for induction of labour in spontaneous and therapeutic abortion is gemeprost. The authors report a case of spontaneous uterine rupture of a scarred uterus, for previous caesarean sections, in a woman at 20 weeks of gestation with a diagnosis of spontaneous abortion. She received a pessary of gemeprost every three hours. After the fifth pessary, she complained of severe pain. At the ultrasound examination, uterine cavity appeared empty and the dead fetus was dislocated in the abdomen. Emergency laparotomy was performed and uterine tear was repaired. To induce labour for fetal demise or therapeutic abortion in second trimester in women with scarred uterus, the authors decided to lengthen the time between administrations of pessary from four to five hours depending on patient's symptoms. However the appropriate drug regimen has still to be found and more data are necessary.

Ultrasound management and clinical outcome of twin pregnancies.

The rate of multiple pregnancies is showing a significant increase in Western countries. Twin gestations should be considered a high-risk condition because they are responsible for a disproportionate amount of overall perinatal morbidity and mortality. We used a specialised ultrasound protocol based on chorionicity to monitor 44 twin pregnancies (61% dichorionic diamniotic (DD) and 39% monochorionic diamniotic (MD)). Adverse pregnancy outcomes and pre-term deliveries were more common in MD pregnancies than in DD pregnancies; the rate of extreme pre-term delivery (< 32 weeks) was almost three-times higher in MD than in DD pregnancies (41% vs 15%) and perinatal complications were more frequent in MD than in DD pregnancies (59% vs 22%), but fetal anomalies were more frequent in DD than in MD pregnancies (30% vs 24%). Periodic ultrasound follow-up would predict the pregnancies that are at greater risk for fetal and neonatal complications and these should be monitored more closely.

Mediastinal masses: a case of fetal teratoma and literature review.

Fetal mediastinal masses are rare congenital formations that could complicate pregnancy. They are usually discovered as space occupying lesions in the fetal chest during routine ultrasound scan. The most important prognostic factors of mediastinal masses are mass location, compressing effect causing pulmonary hypoplasia and/or heart failure, and the presence or absence of hydrops. We report a case of fetal mediastinal teratoma and a review of the literature. A 32-year-old woman carrying a fetus with hydrops due to a mediastinal mass underwent cesarean section at 32 1/7 weeks' gestation. A well encapsulated tumor was excised by surgery at one day of life. The baby is now eight months old without respiratory difficulty. To our knowledge, this is the fourth case report of a mediastinal teratoma associated with nonimmune hydrops in a fetus that survived the neonatal period. Fetal mediastinal teratoma requires close surveillance and multidisciplinary management by obstetricians, neonatologists, and pediatric surgeons.

[Pregnancy in lupus patients: our experience]. / La gravidanza nelle pazienti con lupus: nostra esperienza.

AIM: Systematic lupus erythematosus (SLE) is the most common autoimmune disease associated with pregnancy. The aim of this study was to evaluate management and outcome of pregnancy complicated by SLE. METHODS: Twenty pregnant women affected by SLE were admitted to Prenatal Diagnosis Centre of University "Sapienza" from January 2007 to July 2009. Pregnancy was monitored from diagnosis to delivery by at least a monthly consultation. At each visit general blood laboratory assessment were registered. An ultrasound examination was performed to evaluate fetal growth. From 26 weeks of gestation an estimation of fetal weight was calculated according to the standard of Lubchenco. At birth newborns weight was registered. RESULTS: Patient mean age was 32.9 years. There were 18 live births (90%), and 2 spontaneous abortions; 50% of pregnancy ended with a preterm delivery. 20% of the patient had signs of disease activity during pregnancy. Fifteen percent of women presented gestational hypertension. An high rate of small for gestational age was registered and 2 cases of intrauterine growth retardation (IUGR). Ultrasound evaluation at 28-30 weeks of gestation showed a normal weight (≥ 50th percentile) in 83% fetuses. Only 45% of the newborns presented ≥ 50th percentile. The mean weight of the newborns was 2700 grams. CONCLUSION: Pregnancy outcome could be improved by close obstetrical and ultrasound monitoring in a multidisciplinary setting.

Antifungal activity of plant and bacterial ureases.

Ureases (EC 3.5.1.5) are nickel-dependent metalloenzymes that catalyze the hydrolysis of urea to ammonia and carbon dioxide. Produced by plants, fungi and bacteria, but not by animals, ureases share significant homology and similar mechanisms of catalysis, although differing in quaternary structures. While fungal and plant ureases are homo-oligomeric proteins of 90 kDa subunits, bacterial ureases are multimers of two (e.g. Helicobacter pylori) or three subunit complexes. It has been proposed that in plants these enzymes are involved in nitrogen bioavailability and in protection against pathogens. Previous studies by our group have shown that plant ureases, but not a bacterial (Bacillus pasteurii) urease, display insecticidal activity. Herein we demonstrate that (Glycine max) embryo-specific soybean urease, jackbean (Canavalia ensiformis) major urease and a recombinant H. pylori urease impair growth of selected phytopathogenic fungi at sub-micromolar concentrations. This antifungal property of ureases is not affected by treatment of the proteins with an irreversible inhibitor of the ureolytic activity. Scanning electron microscopy of urease-treated fungi suggests plasmolysis and cell wall injuries. Altogether, our data indicate that ureases probably contribute to the plant arsenal of defense compounds against predators and phytopathogens and that the urease defense mechanism is independent of ammonia release from urea.

Energetics of midvelocity emissions in peripheral heavy ion collisions at Fermi energies.

Peripheral and semiperipheral collisions have been studied in the system 93Nb+93Nb at 38A MeV. The evaporative and midvelocity components of the light charged particle and intermediate mass fragment emissions have been carefully disentangled. In this way it was possible to obtain the average amount not only of charge and mass, but also of energy, pertaining to the midvelocity emission, as a function of an impact parameter estimator. This emission has a very important role in the overall balance of the reaction, as it accounts for a large fraction of the emitted mass and for more than half of the dissipated energy. As such, it may give precious clues on the microscopic mechanism of energy transport from the interaction zone toward the target and projectile remnants.

Intermediate mass fragment emission pattern in peripheral heavy-ion collisions at Fermi energies.

The emission pattern in the v(perp)-v(par) plane of intermediate mass fragments with Z = 3--7 (IMF) has been studied in the collision 116Sn+ 93Nb at 29.5A MeV as a function of the total kinetic energy loss of the reaction. This pattern shows that for peripheral reactions most IMF's are emitted at velocities intermediate between those of the projectile- and target-like products. Coulomb trajectory calculations show that these IMF's are produced in the interaction zone in a short time interval at the end of the target-projectile interaction.

Distinct effects of auxin and light on adventitious root development in Eucalyptus saligna and Eucalyptus globulus.

Adventitious rooting is essential for vegetative propagation of woody species. We studied the effects of auxin and light on the development of adventitious roots in cuttings obtained from seedlings of Eucalyptus saligna Smith and E. globulus Labill in an attempt to characterize the adventitious rooting process and identify factors controlling rhizogenesis. Root development was scored as rooting percentage, root density (roots per rooted cutting), mean rooting time and root length. In both species, rooting time was reduced in the presence of auxin. Cuttings from 2-month-old E. saligna seedlings were responsive to lower auxin concentrations than comparable cuttings from E. globulus seedlings. Cuttings from 3-month-old E. saligna seedlings rooted promptly and rooting was not significantly affected by light conditions. In contrast, rooting of cuttings from 3-month-old E. globulus seedlings exhibited recalcitrant behavior and no roots were formed if illuminated during the root formation phase. Effective root regeneration of E. globulus cuttings was obtained by a 4-day exposure to 10 mg l(-1) IBA and culture in darkness during the root formation step. Loss of rooting capacity with seedling age was more pronounced in E. globulus than in E. saligna. The possibility of switching adventitious rooting off and on by manipulating light regime and exogenous auxin supply in E. globulus, and the constitutive nature of rooting in E. saligna may provide useful models for examining the rooting process at the biochemical and molecular levels in Eucalyptus.

The promoter of the strictosidine synthase gene from periwinkle confers elicitor-inducible expression in transgenic tobacco and binds nuclear factors GT-1 and GBF.

Strictosidine synthase (STR) is a key enzyme in the biosynthesis of terpenoid indole alkaloids. This class of secondary metabolites harbours several pharmaceutically important compounds used, among other applications, in cancer treatment. Terpenoid indole alkaloid biosynthesis and expression of biosynthetic genes including Str1 is induced by fungal elicitors. To identify elicitor-responsive regulatory promoter elements and trans-acting factors, the single-copy Str1 gene was isolated from the subtropical plant species Catharanthus roseus (Madagascar periwinkle). Str1 upstream sequences conferred elicitor-responsive expression to the beta-glucuronidase (gusA) reporter gene in transgenic tobacco plants. Main enhancer sequences within the Str1 promoter region studied were shown to be located between -339 and -145. This region and two other regions of the promoter bound the tobacco nuclear protein factor GT-1. A G-box located around position -105 bound nuclear and cloned G-box-binding factors (GBFs). A mutation that knocked out GBF binding had no measurable effect on expression, which indicates that the G-box is not essential for the elicitor responsiveness of the Str1 promoter. No obvious homologies with promoter elements identified in other elicitor-responsive genes were observed, suggesting that the Str1 gene may depend on novel regulatory mechanisms.

A new method to detect crackles in respiratory sounds.

In this paper, an automatic method to detect and analyze crackles in digitised respiratory sounds is presented. The method is based on two steps: (1) a threshold (T) value is applied to the first derivative absolute value (FDAV) of lung sound to locate the "zone of interest" and (2) in this zone a crackle is detected if certain conditions are verified. The first derivative (FD) is evaluated by means of a derivative-smoothing filter, preserving areas under the spectral lines of the signal (moment zero), its mean position in time (first moment) and its spectral line width (second moment). The conditions to verify step 2 concern the following: the number and height of the peaks of FDAV and their distances from the starting point of the crackle, within a temporal window TW. This method shows good performances as an automatic detector (sensitivity 84% and specificity 89%), and is specifically designed to find the starting point of the crackle.

Effects of over-expression of strictosidine synthase and tryptophan decarboxylase on alkaloid production by cell cultures of Catharanthus roseus.

Cells of Catharanthus roseus (L.) G. Don were genetically engineered to over-express the enzymes strictosidine synthase (STR; EC 4.3.3.2) and tryptophan decarboxylase (TDC; EC 4.1.1.28), which catalyze key steps in the biosynthesis of terpenoid indole alkaloids (TIAs). The cultures established after Agrobacterium-mediated transformation showed wide phenotypic diversity, reflecting the complexity of the biosynthetic pathway. Cultures transgenic for Str consistently showed tenfold higher STR activity than wild-type cultures, which favored biosynthetic activity through the pathway. Two such lines accumulated over 200 mg.L-1 of the glucoalkaloid strictosidine and/or strictosidine-derived TIAs, including ajmalicine, catharanthine, serpentine, and tabersonine, while maintaining wild-type levels of TDC activity. Alkaloid accumulation by highly productive transgenic lines showed considerable instability and was strongly influenced by culture conditions, such as the hormonal composition of the medium and the availability of precursors. High transgene-encoded TDC activity was not only unnecessary for increased productivity, but also detrimental to the normal growth of the cultures. In contrast, high STR activity was tolerated by the cultures and appeared to be necessary, albeit not sufficient, to sustain high rates of alkaloid biosynthesis. We conclude that constitutive over-expression of Str is highly desirable for increased TIA production. However, given its complexity, limited intervention in the TIA pathway will yield positive results only in the presence of a favorable epigenetic environment.

Suspension cultured transgenic cells of Nicotiana tabacum expressing tryptophan decarboxylase and strictosidine synthase cDNAs from Catharanthus roseus produce strictosidine upon secologanin feeding.

A transgenic cell suspension culture of Nicotiana tabacum L. `Petit Havana' SR1 was established expressing tryptophan decarboxylase and strictosidine synthase cDNA clones from Catharanthus roseus (L.) G. Don under the direction of cauliflower mosaic virus 35S promoter and nopaline synthase terminator sequences. During a growth cycle, the transgenic tobacco cells showed relatively constant tryptophan decarboxylase activity and an about two- to sixfold higher strictosidine synthase activity, enzyme activities not detectable in untransformed tobacco cells. The transgenic culture accumulated tryptamine and produced strictosidine upon feeding of secologanin, demonstrating the in vivo functionality of the two transgene-encoded enzymes. The accumulation of strictosidine, which occurred predominantly in the medium, could be enhanced by feeding both secologanin and tryptamine. No strictosidine synthase activity was detected in the medium, indicating the involvement of secologanin uptake and strictosidine release by the cells.