Folic acid enhances the apoptotic and genotoxic activity of carboplatin in HeLa cell line.

In human tumor cells, experimental and clinical evidence indicates that some factors involved in signal transduction and cell growth can also modulate the response to chemotherapeutic treatment. The aim of the present study was to investigate the role of folic acid (FA) as a modulator of carboplatin (CBDCA) activity. Genotoxicity and cytotoxicity induced by CBDCA alone and in combination with FA were assessed in cultured HeLa cells. We used comet assay, mitotic index analysis, MTT and NR assays, cytokinesis-block micronucleus cytome assay and annexin V-IP as different cytotoxicity and genotoxicity approaches for human cervical carcinoma cell line studies. The results showed that addition of 900nM FA together with 40.4mM CBDCA enhanced the activity of the platinum compound, increasing its effect on cell death by nearly 20%, as evidenced by the MTT and NR assays. Moreover, not only higher levels of DNA and chromosomal damage were reached but also the number of necrotic and apoptotic cells were significantly increased when cell cultures were treated with the combined procedure. This situation opens the possibility to explore the use of FA in platinum-based chemotherapy protocols to reduce the platinum doses for patient treatment and decrease the chance of developing the known side effects without losing biological activity.

Genotoxic Effects Induced by Cd(+2), Cr(+6), Cu(+2) in the Gill and Liver of Odontesthes bonariensis (Piscies, Atherinopsidae).

Genotoxic effects of Cd(+2), Cr(+6), and Cu(+2) on the gill and liver of the Argentinean Silverside (Odontesthes bonariensis) were studied using the comet assay and in relation with the metal tissue accumulation. Fish were exposed to three waterborne concentrations of each metal for 2 and 16 days. Genotoxicity was assessed by the single cell gel electrophoresis (comet assay). After 2 days, significant increase of the genetic damage index (GDI) was only observed in the gill of fish exposed to Cr(+6) and Cu(+2), and the LOECs were 2160 nM and 921.1 nM, respectively. The gill LOEC for Cd(+2) by 16 days was 9.4 nM. In the liver, LOECs were obtained only for Cd(+2) and Cr(+6) and were 9.4 and 2160 nM, respectively. The three metals were able to induce genotoxic effects at environmentally relevant concentrations and the gill was the most sensitive organ.

Foot posture is associated with morphometry of the peroneus longus muscle, tibialis anterior tendon, and Achilles tendon.

The aim of this study was to investigate the association between foot type and the morphometry of selected muscles and tendons of the lower limb. Sixty-one healthy participants (31 male, 30 female; aged 27.1 ± 8.8 years) underwent gray-scale musculoskeletal ultrasound examination to determine the anterior-posterior (AP) thickness of tibialis anterior, tibialis posterior, and peroneus longus muscles and tendons as well as the Achilles tendon. Foot type was classified based on arch height and footprint measurements. Potentially confounding variables (height, weight, hip and waist circumference, rearfoot and ankle joint range of motion, and levels of physical activity) were also measured. Multiple linear regression models were used to determine the association between foot type with muscle and tendon morphometry accounting for potentially confounding variables. Foot type was significantly and independently associated with AP thickness of the tibialis anterior tendon, peroneus longus muscle, and Achilles tendon, accounting for approximately 7% to 16% of the variation. Flat-arched feet were associated with a thicker tibialis anterior tendon, a thicker peroneus longus muscle, and a thinner Achilles tendon. Foot type is associated with morphometry of tendons that control sagittal plane motion of the rearfoot; and the peroneus longus muscle that controls frontal plane motion of the rearfoot. These findings may be related to differences in tendon loading during gait.

Interlaboratory comparison of dicentric chromosome assay using electronically transmitted images.

The bottleneck in data acquisition during biological dosimetry based on a dicentric assay is the need to score dicentrics in a large number of lymphocytes. One way to increase the capacity of a given laboratory is to use the ability of skilled operators from other laboratories. This can be done using image analysis systems and distributing images all around the world. Two exercises were conducted to test the efficiency of such an approach involving 10 laboratories. During the first exercise (E1), the participant laboratories analysed the same images derived from cells exposed to 0.5 and 3 Gy; 100 images were sent to all participants for both doses. Whatever the dose, only about half of the cells were complete with well-spread metaphases suitable for analysis. A coefficient of variation (CV) on the standard deviation of ∼15 % was obtained for both doses. The trueness was better for 3 Gy (0.6 %) than for 0.5 Gy (37.8 %). The number of estimated doses classified as satisfactory according to the z-score was 3 at 0.5 Gy and 8 at 3 Gy for 10 dose estimations. In the second exercise, an emergency situation was tested, each laboratory was required to score a different set of 50 images in 2 d extracted from 500 downloaded images derived from cells exposed to 0.5 Gy. Then the remaining 450 images had to be scored within a week. Using 50 different images, the CV on the estimated doses (79.2 %) was not as good as in E1, probably associated to a lower number of cells analysed (50 vs. 100) or from the fact that laboratories analysed a different set of images. The trueness for the dose was better after scoring 500 cells (22.5 %) than after 50 cells (26.8 %). For the 10 dose estimations, the number of doses classified as satisfactory according to the z-score was 9, for both 50 and 500 cells. Overall, the results obtained support the feasibility of networking using electronically transmitted images. However, before its implementation some issues should be elucidated, such as the number and resolution of the images to be sent, and the harmonisation of the scoring criteria. Additionally, a global website able to be used for the different regional networks, like Share Points, will be desirable to facilitate worldwide communication.

Biological dosimetry intercomparison exercise: an evaluation of triage and routine mode results by robust methods.

Well-defined protocols and quality management standards are indispensable for biological dosimetry laboratories. Participation in periodic proficiency testing by interlaboratory comparisons is also required. This harmonization is essential if a cooperative network is used to respond to a mass casualty event. Here we present an international intercomparison based on dicentric chromosome analysis for dose assessment performed in the framework of the IAEA Regional Latin American RLA/9/054 Project. The exercise involved 14 laboratories, 8 from Latin America and 6 from Europe. The performance of each laboratory and the reproducibility of the exercise were evaluated using robust methods described in ISO standards. The study was based on the analysis of slides from samples irradiated with 0.75 (DI) and 2.5 Gy (DII). Laboratories were required to score the frequency of dicentrics and convert them to estimated doses, using their own dose-effect curves, after the analysis of 50 or 100 cells (triage mode) and after conventional scoring of 500 cells or 100 dicentrics. In the conntional scoring, at both doses, all reported frequencies were considered as satisfactory, and two reported doses were considered as questionable. The analysis of the data dispersion among the dicentric frequencies and among doses indicated a better reproducibility for estimated doses (15.6% for DI and 8.8% for DII) than for frequencies (24.4% for DI and 11.4% for DII), expressed by the coefficient of variation. In the two triage modes, although robust analysis classified some reported frequencies or doses as unsatisfactory or questionable, all estimated doses were in agreement with the accepted error of ±0.5 Gy. However, at the DI dose and for 50 scored cells, 5 out of the 14 reported confidence intervals that included zero dose and could be interpreted as false negatives. This improved with 100 cells, where only one confidence interval included zero dose. At the DII dose, all estimations fell within ±0.5 Gy of the reference dose interval. The results obtained in this triage exercise indicated that it is better to report doses than frequencies. Overall, in both triage and conventional scoring modes, the laboratory performances were satisfactory for mutual cooperation purposes. These data reinforce the view that collaborative networking in the case of a mass casualty event can be successful.

Energy localization in the phi4 oscillator chain.

We study energy localization in a finite one-dimensional phi(4) oscillator chain with initial energy in a single oscillator of the chain. We numerically calculate the effective number of degrees of freedom sharing the energy on the lattice as a function of time. We find that for energies smaller than a critical value, energy equipartition among the oscillators is reached in a relatively short time. On the other hand, above the critical energy, a decreasing number of particles sharing the energy is observed. We give an estimate of the effective number of degrees of freedom as a function of the energy. Our results suggest that localization is due to the appearance, above threshold, of a breather-like structure. Analytic arguments are given, based on the averaging theory and the analysis of a discrete nonlinear Schrödinger equation approximating the dynamics, to support and explain the numerical results.

High reproducibility of patellar tendon vascularity assessed by colour Doppler ultrasonography: a reliable measurement tool for quantifying tendon pathology.

BACKGROUND: This study examined whether patellar tendon vascularity could be quantified accurately in the clinical setting using colour Doppler ultrasonography. METHODS: A sonographer and two radiologists visually estimated tendon vascularity in millimetres in 74 tendons during ultrasound (US) examination and from hard copy films. These estimates were then compared to the length of vessels measured from the digital image in millimetres and the correlation between them was determined. A subset of 16 tendons was used to compare the estimates of vascularity by two examiners at US examination. RESULTS: The estimation of vascular length at US examination correlated highly with the measured vascular length (r = 0.92; 95% confidence interval (CI) 0.87 to 0.94), as did the length estimated from the films (r = 0.94; 95% CI 0.9 to 0.96). The correlation between examiners was 0.84 (95% CI 0.51 to 0.94) for the estimates made during US examination and 0.85 (95% CI 0.59 to 0.95) for the vessel lengths measured from the digital images. CONCLUSIONS: These excellent correlations indicate that tendon vascularity can be reliably estimated using colour Doppler ultrasonography and tendon vascularity could therefore be used by clinicians to rate clinical change. This method of quantifying tendon vascularity could also be used in research to investigate the effects of tendon treatments on vascularity.

Vascularity and pain in the patellar tendon of adult jumping athletes: a 5 month longitudinal study.

BACKGROUND: This study investigated changes in tendon vascularity in 102 (67 men and 35 women) volleyball players over a 6 month competitive season. METHODS: Athletes were examined with both grey scale ultrasound and standardised colour Doppler settings. Vessel length and pain were measured each month on five separate occasions. Vascular tendons were divided into (i) those that were vascular on all occasions (persistent vascularity) and (ii) those that were vascular on more than two but less than five occasions (intermittent vascularity). RESULTS: A total of 41 of the 133 abnormal tendons were vascular on two or more occasions. Of these, 16 had persistent vascularity and 25 had intermittent vascularity. There was no significant difference in the prevalence of vascularity between men and women. None of the tendons had a pattern of vascularity over the season that could be clearly interpreted as the onset or resolution of vascularity. Subjects with changes in both tendons were more likely to have persistent vascularity (p = 0.045). Vessels were longer in tendons with persistent vascularity (p<0.000) and pain was significantly greater (p = 0.043) than in tendons with intermittent vascularity. Tendons with intermittent vascularity had similar pain scores on all days, whether or not they had detectable blood flow. CONCLUSIONS: These data suggest that the presence of blood vessels is more likely to be the source of pain than the blood flow in them.

Association between copper deficiency and DNA damage in cattle.

Cattle hypocuprosis is the second most widespread mineral deficiency affecting grazing cattle. The consequences of hypocuprosis include a failure of copper metalloenzymes, many of which form part of the antioxidant defence system. This work focuses on the association between copper (Cu) plasma concentration and DNA damage in Aberdeen Angus cattle. Two-hundred and ninety-nine heparinized blood samples from 2-year-old Aberdeen Angus cows were obtained from different farms located in the Salado River basin, Argentina. Plasma copper level analysis was carried out in whole samples, while cytogenetic analysis and single cell gel electrophoresis assay (comet assay) were carried out in 82 and 217 samples, respectively. Cytogenetic analysis showed a significant increase in the frequency of abnormal metaphases in moderate/severe hypocupremic groups (groups B and C) in relation to the normocupremic group (group A) (4.5 and 1.5 abnormal metaphases/100 cells, respectively, P < 0.01). The Spearman correlation test showed a negative association between cupremic values and the yield of chromosomal aberrations (r = -0.708, P < 0.0001). In the comet assay greater migration was observed in cells from the hypocupremic group, from a median of 54 in the severe hypocupremic group to 31 in the normocupremic group (P < 0.01). Accordingly, the Spearman correlation test showed a significant positive relationship between copper levels and cells without DNA migration and a significant negative relationship between copper levels and cells with a tiny tail (P < 0.0001 in both cases). The results obtained show that hypocupremia in cattle is associated with an increase in the frequency of chromosomal aberrations as well as in DNA migration as assessed by the comet assay. Whereas the comet assay could differentiate copper plasma level groups, chromosomal aberrations only detected differences between normal and hypocupremic animals. The increase of DNA damage found in hypocupremic animals could be explained by higher oxidative stress suffered by these animals.

Gene frequency distribution of the BoLA-DRB3 locus in Saavedreño Creole dairy cattle.

The objective of this study is to describe the gene frequency distribution of the bovine lymphocyte antigen (BoLA)-DRB3 locus in Saavedreño Creole dairy cattle and to compare it with previously reported patterns in other cattle breeds. One hundred and twenty-five Saavedreño Creole dairy cattle were genotyped for the BoLA-DRB3.2 allele by polymerase chain reaction and restriction fragment length polymorphism. Twenty-two out of 53 previously identified BoLA-DRB3.2 alleles were detected, with gene frequencies ranging from 0.4 to 16.8%. Seventy percent of the variation corresponded to the seven most frequent alleles (BoLA-DRB3.2*7, *8, *11, *16, *27, *36, and *37). The studied population exhibits a high degree of expected heterozygosity (he = 0.919). The FIS index did not show significant deviation from Hardy-Weinberg equilibrium. However, the neutrality test showed an even gene frequency distribution. This result could be better explained assuming balancing selection instead of neutral or positive selection for one or a few alleles. In conclusion, the results of this study demonstrated that BoLA-DRB3.2 is a highly polymorphic locus in Saavedreño Creole dairy cattle, with significant variation in allele frequency among cattle breeds.

Patagonian Argentine Creole cattle polymorphism: comparison with North-West populations of this breed.

The relict Patagonian Argentine Creole cattle population consist of a small feral population (Los Glaciares population) that is geographically isolated in the South-West of Patagonia. In order to determine the level of genetic variability of this population, the polymorphism of eight structural genes and two microsatellites loci were studied using the polymerase chain reaction (PCR). In addition, genetic characterisation was used to compare Los Glaciares population and the ACc breed of cattle. Results obtained in this study show that the value of average heterozygosity of the studied loci for the Los Glaciares were not significantly different from the ACc. Furthermore, the data of this report were consistent with the hypothesis that Los Glaciares originated from ACc brought to the area by colonialists in the last century. Such data may be useful in formulating management plans for Feral Patagonian Creole cattle populations.

Analysis of genetic diversity and population structure in Argentine and Bolivian Creole cattle using five loci related to milk production

Data from five protein-coding loci related to dairy production were used to study the genetic diversity and population structure of Argentine and Bolivian Creole cattle breeds. Genomic DNA was extracted from blood samples of six Creole cattle breeds: Argentine (n = 230), Patagonian (n = 25); "Saavedreño" (n = 140), "Chaqueño Boliviano" (n = 30), "Yacumeño" (n = 27), and "Chusco" (n = 11). kappa-casein, beta-lactoglobulin, growth hormone and prolactin were measured by PCR-RFLP, while alphaS1-casein was typed by PCR-ASO. The results are discussed, focusing on: historical origin, recent differentiation and selection events, Zebu gene introgression, and population structure. This work shows that: (i) For the studied genes, the observed gene frequency profiles of Argentine and Bolivian Creole cattle breeds were close to the data reported for Iberian breeds and for other South-American Creole cattle breeds which are historically related; (ii) although Zebu gene introgression has been reported at the studied loci, these breeds seem to be far from the Zebu gene frequency profiles; and (iii) the Argentine and Bolivian Creole cattle showed significant levels of subdivision, but each population has maintained its degree of genetic variability

Incidence of 1/29 translocation in Bolivian Creole and Brahman Yacumeño cattle.

In Bolivia, four different Creole cattle breeds can be found, as well as other European and Zebu breeds adapted to local environments. The relationship between the occurrence of the 1/29 translocation and subfertility is well known, and analysis of Y chromosome morphology is useful to determine a possible introgression with Bos indicus. The incidence of the 1/29 translocation was analyzed in four Bolivian Creole cattle breeds and the Brahman Yacumeño population, as well as on four farms with phenotypical Creole-type cattle. In 259 (164 dams and 95 sires) Bolivian Creole cattle, 10.42% of the individuals demonstrated the 1/29 translocation, with a variation from 0 to 28.20% between the breeds. In contrast, 43 (19 dams and 24 sires) Yacumeño Brahman and the Creole-type cattle did not show the centric fusion. The highly significant differences between Creole cattle breeds in relation to the incidence of 1/29 translocation could be a consequence of factors such as founder group, genetic drift, and selection. The low frequency observed in the Saavedreñio Creole dairy cattle might be explained by its breeding under a more intensive system, and selection according to milk yield and fertility traits. Finally, no relation between acrocentric Y chromosomes and 1/29 translocation was observed.

Diagnostic and therapeutic dilemma with large prenatally detected cystic adrenal masses.

OBJECTIVES: The prenatal finding of a large cystic adrenal mass raises the dilemma of the differential diagnosis between adrenal hemorrhage and cystic neuroblastoma. The possibility of a neuroblastoma usually leads to surgical excision of such tumors. Nevertheless, an adrenal hemorrhage has to be recognized, so that unnecessary surgery may be avoided. METHODS: Three cases of large prenatally detected adrenal masses managed nonoperatively are reported. Data studied were: age at the diagnosis, prenatal and postnatal ultrasonographic consistency, and tumor marker levels. Size and sonographic evolution were also studied. RESULTS: In all 3 cases, a cystic mass, measuring more than 40 mm in size, was detected during the 3rd trimester of pregnancy. The sonographic appearance evolved from a sonolucent tumor to a heterogeneous mass with hyperechoic areas. The tumor marker levels were normal. All infants had a documented decrease in mass size at birth and were managed nonoperatively. All these tumors were considered adrenal hemorrhages. CONCLUSIONS: Prenatal ultrasonography rarely permits to distinguish an adrenal hemorrhage from a cystic neuroblastoma. The differential diagnosis, even in large masses, is based on close postnatal follow-up with serial sonography. Surgery is not mandatory, unless the size does not decrease. However, without pathologic proof, it is not possible to differentiate an adrenal hemorrhage from a spontaneously resolved neuroblastoma.

DNA damage induced by copper deficiency in cattle assessed by the Comet assay.

Cattle hypocuprosis is a well-known endemic disease in several parts of the world. In a previous paper, the clastogenic effect of copper deficiency in cattle has been described although the occurrence of DNA damage was not directly tested. For this reason, the relation between DNA damage assessed by the Comet assay and Cu plasma concentration was studied in Aberdeen Angus cattle. Blood samples were obtained in heparinized Vacutainer tubes from 28 female Aberdeen Angus cows during pregnancy or immediately after to give birth. Each sample was divided into two aliquots for Comet assay and Cu plasma determination, respectively. From the 28 cattle sampled, 17 were normocupremic and 11 were hypocupremic. Results obtained showed that whereas the average plasma Cu level in normocupremic cattle was 67.6 microg/dl, in hypocupremic cattle it was 32.1 microg/dl. The increase of DNA damage was mostly evidenced by the decrease of comet degree 1 cells and an increase of comet degree 2 cells. Correlation analysis comparing plasma Cu levels and degree 1 cells showed a correlation coefficient 0.72 (P<0.01). The comparison between plasma Cu levels and comet degree 2 cells was -0.65 (P<0.01). The comparison between plasma Cu levels and the comet length-head diameter medians determined in 23 out of 28 animals showed a correlation coefficient of -0.54 (P<0.01). The induction of DNA damage was clearly supported by the fact that the decrease of plasma Cu levels was correlated with the increase of comet length-head diameter. These findings could be considered as a contribution to the hypothesis that DNA and chromosome damage are a consequence of the higher oxidative stress suffered by hypocupremic animals.

Male-mediated introgression of Bos indicus genes into Argentine and Bolivian Creole cattle breeds.

The geographic distribution and frequency of Bos taurus and Bos indicus Y chromosome haplotypes amongst Argentine and Bolivian Creole cattle breeds were studied, using cytogenetic and molecular genetic techniques. A complete correspondence between Y chromosome morphology and the haplotype of the Y-linked microsatellite marker INRA 124 was found in all males examined. The taurine and indicine haplotypes were detected in 85.7 and 14.3% of the males studied, respectively, although these frequencies varied amongst the different breeds examined. The geographic distribution of this polymorphism suggests a pattern of zebu introgression in South America. The highest frequencies of the Zebu Y-chromosome are found in Brazilian populations (43-90%), in the eastern part of the continent, while it is absent in the southernmost breeds from Uruguay and Argentina. Bolivian breeds, at the centre of the continent, exhibit intermediate values (17-41%). This east/west and north/south gradient of male Zebu introgression could be explained by historical events and environmental factors.

Simple dynamical system with discrete bound states

We study numerically the dynamical system of a two-electron atom with the Darwin interaction as a model to investigate scale-dependent effects of the relativistic action-at-a-distance electrodynamics. This dynamical system consists of a small perturbation of the Coulomb dynamics for energies in the atomic range. The key properties of the Coulomb dynamics are (i) a peculiar mixed-type phase space with sparse families of stable nonionizing orbits and (ii) scale-invariance symmetry, with all orbits defined by an arbitrary scale parameter. The combination of this peculiar chaotic dynamics [(i) and (ii)], with the scale-dependent relativistic corrections (Darwin interaction), generates the phenomenon of scale-dependent stability: We find numerical evidence that stable nonionizing orbits can exist only for a discrete set of resonant energies. The Fourier transform of these nonionizing orbits is a set of sharp frequencies. The energies and sharp frequencies of the nonionizing orbits we study are in the quantum atomic range.

Chronic fatigue syndrome beginning suddenly occurs seasonally over the year.

The fact that many patients with chronic fatigue syndrome (CFS) have an infectious like sudden onset to their illness has led to the hypothesis that CFS is a medical illness. If CFS were, on the other hand, a psychiatric disorder related to symptom amplification, one would expect illness onset to occur randomly over the calendar year. This study tested that hypothesis with 69 CFS patients whose illness was on the more severe side of the illness spectrum; all patients reported sudden illness onset with the full syndrome of sore throat, fatigue/malaise, and diffuse achiness developing over no longer than a 2-day period. Date of illness onset was distinctly nonrandom. It peaked from November through January and was at its lowest from April through May. These data support the hypothesis that an infectious illness can trigger the onset of CFS.

Clastogenic effect of copper deficiency in cattle.

Copper plays an essential role as a micronutrient. Deficiency of this element (hypocuprosis) in experimental and domestic animals has a severe impact on growth as well as on reproduction. The occurrence of lesions during hypocuprosis is correlated with the depletion of an enzymatic group in which copper takes part. The aim of this work was to analyse chromosomal aberrations in Aberdeen Angus cows of the province of Buenos Aires in relation with the Cu plasma levels. Short term lymphocyte cultures were made from samples obtained from four groups of animals: two groups with normal levels of copper in plasma and two groups with severe hypocupremia. This analysis showed a significant increase of the frequency of chromosomal aberrations (p<0.001) in the hypocupremic groups in relation with control groups. Finally, the Spearman correlation analysis showed a significant negative association (p<0.05) between copper levels and the yield of chromosomal aberrations. The increase of the frequencies of chromosomal aberrations found in the hypocupremic groups could be explained by the higher oxidative stress suffered by these animals. A lower catalytic activity of enzymes such as Cu/Zn superoxide dismutase (Cu/Zn-SOD) and cytochrome-c oxidase could increase the intracellular production of active oxygen species (O(2)(-), H(2)O(2) and OH(o)) with the consequent clastogenic effects.