Pseudo-two-dimensional dynamics in a system of macroscopic rolling spheres.

We study in this work the dynamics of a collection of identical hollow spheres (ping-pong balls) that rest on a horizontal metallic grid. Fluidization is achieved by means of a turbulent air current coming from below. The upflow is adjusted so that the particles do not levitate over the grid, resulting in quasi-two-dimensional dynamics. We show that the behavior of diffusion and correlations in this system is particularly rich. Noticeably as well (and related to the complex dynamical behavior), a variety of phases appear, with important peculiarities with respect to analogous setups. We observe gas, liquid, glass, and hexagonal crystal phases. Most notably, we show that the melting of the hexagonal crystal occurs in coexistence with a liquid phase. This strikingly differs from the corresponding transition in a purely two-dimensional systems of air-fluidized disks, for which no phase coexistence has been reported in the literature.

Zero-gravity thermal convection in granular gases.

Previous experimental and theoretical evidence has shown that convective flow may appear in granular fluids if subjected to a thermal gradient and gravity (Rayleigh-Bénard-type convection). In contrast to this, we present here evidence of gravity-free thermal convection in a granular gas, with no presence of external thermal gradients either. Convection is here maintained steady by internal gradients due to dissipation and thermal sources at the same temperature. The granular gas is composed by identical disks and is enclosed in a rectangular region. Our results are obtained by means of an event-driven algorithm for inelastic hard disks.

Analysis of blood markers for early breast cancer diagnosis.

PURPOSE: Breast cancer is the most common neoplasm in women and has the highest associated mortality rate. Rapid detection programmes can provide early diagnosis and increase the chances of survival. There are no specific tumor biomarkers for the early phase of the disease. The primary aim of this study was to search a blood biomarker with levels that exceeded the normal range established in the general population that could be used to screen breast cancer. METHODS/PATIENTS: Case-control study. Conventional as well as research (NGAL, EGFR and 8-OHdG) tumor biomarkers were analyzed. RESULTS: A total of 126 women were enrolled (cases: 63 patients with local breast cancer; Controls: 63 healthy women). Significant differences were found in patients with higher levels of the conventional markers, Ca15.3, CEA, Cyfra 21.1 and NSE. However, when commercial cut-off values were used, only Ca 15.13 was significant. In the group of research biomarkers, significantly higher levels of EGFR were found in the control group, and of 8-OHdG in the case group. Using logistic regression analysis and a ROC curve, an equation composed of five markers, Ca 15.3, NSE, NGAL, EGFR and 8-OHdG, which yielded a correct diagnostic probability of breast cancer of 91.8% was obtained. CONCLUSIONS: 8-OHdG has been identified as a new potential marker for screening early stage breast cancer. In addition, a model that combines five blood markers that can be used as a diagnostic test in certain groups of patients has been developed. New studies with a larger sample size are needed to verify the results obtained.

Purtscher-like retinopathy associated with dermatomyositis and hemophagocytic lymphohistiocytosis. / Retinopatía Purtscher-like asociada a dermatomiositis y linfohistiocitosis hemofagocítica.

CASE REPORT: An 11 year-old girl with progressive muscle weakness due to dermatomyositis and hemophagocytic lymphohistiocytosis in which multiple cotton exudates, venous tortuosity and flame haemorrhages are detected in the funduscopic examination, leading to the diagnosis of Purtscher-like retinopathy. DISCUSSION: Purstcher's retinopathy is a microvascular disorder with clinical signs of probable thrombotic origin. Its treatment is controversial, with systemic corticosteroids being the most widespread choice.

Recurrent conjunctival atypical fibroxanthoma in Pigmentosum Xeroderma. / Fibroxantoma atípico conjuntival recurrente en el xeroderma pigmentoso.

CASE REPORT: A 7 year-old boy with Xeroderma Pigmentosum (XP) and who presents a recurrent conjunctival atypical fibroxanthoma after two surgeries. This is the third procedure and the patient is treated with a surgical excision of the tumour and cryotherapy at the surgical bed. Due to the risk of recurrence, topical Mitomycin C 0,02% was added at post-operative care achieving a good clinical outcome. DISCUSSION: Surgical exeresis with cryotherapy and topical Mitomycin C is an effective treatment for a case of an atypical fibroxanthoma with a high potential for recurrence and invasion. An ophthalmologic follow-up is required for these patients, as well as general paediatric care and support aids.

Effect of unilateral congenital cataract surgery on ocular axial length growth and corneal flattening.

OBJECTIVE: The aim of this article is to study the effect of unilateral congenital cataract surgery on ocular growth and corneal flattening. METHODS: This is a cross-sectional study of 59 patients operated on due to a unilateral congenital cataract. The median age of the patients at the time of diagnosis was 17 months (interquartile range, 5-39 months). The median age at cataract the time of surgery was 28 months (interquartile range, 8-52 months), and the mean follow-up between cataract surgery and assessments was 149.7±69.9 months (range, 30-319 months). Axial length and corneal curvature were measured in both operated and non-operated eyes, comparing the results between them. RESULTS: There were no statistically significant differences for axial length growth or corneal flattening between operated and non-operated eyes: axial length (P=.327, Student t test) and corneal curvature (P=.078, Student t test). A sub-analysis was performed using the visual acuity and the age of the patient at the time of surgery. The only statistically significant data (P=.007, Student t test) was a lower axial length in operated eyes compared to non-operated eyes, in the non-deep-amblyopia group. CONCLUSIONS: No significant axial length growth modifications were observed between operated and non-operated eyes. Only the non-deep-amblyopia group presented with a lower axial length in the operated eyes compared to non-operated eyes. No significant differences in corneal flattening were found between groups after unilateral congenital cataract surgery.

Childhood obesity and hormonal abnormalities associated with cancer risk.

There is growing evidence that overweight and obesity increase the risk of certain cancers. Studies in adults support the role of insulin-like growth factors (IGFs) and oestrogens in the pathogeneses of several cancers. We propose that hormone alterations described as risk factors for cancer in obese adults are present in prepubertal obese children. A group of obese children aged 6-9 years (n=40), and control group paired for age and sex, were used for the study. The obese children presented a significantly high level of IGF-I (P=0.0173) and insulin (P=0.0250), with a drop in sex hormone-binding globulin (SHBG) (P=0.0282). The 17 beta-oestradiol (E2)/SHBG ratio increase in obese subjects was marginally significant (P=0.0635). Grouping together all the children in quartiles for insulin and body mass index, the upper quartiles showed a rise in IGF-I and E2/SHBG. In a multivariant correlation analysis, only height (partial r=0.2464) and insulin (partial r=0.3002) were independent prediction variables for IGF-I concentration. The only variables statistically correlated with the E2/SHBG ratio were insulin (r=0.2879) and IGF-I (r=0.4140). The obese children in our study showed hormone changes described as risk factors for cancer in obese adults. These changes were significantly associated with the hyperinsulinaemia. We hypothesize that this potential risk should be taken into account given the long period of exposure involved in the presence of hormone alterations at such early ages.

Screening program for retinopathy of prematurity in Spain.

OBJECTIVE: To prepare a retinopathy of prematurity (ROP) screening program as agreed by most of Spanish ophthalmologists dedicated to this topic. MATERIALS AND METHODS: A draft of the protocol was produced taking into account the experience of the participants and current publications. This draft was corrected by all the ophthalmologists participating in the project and the final document produced was agreed by all of them. RESULTS: We present general guidelines to help in the screening of ROP, including treatment criteria, treatment methods, and a calendar of action. CONCLUSIONS: It is important to have a common working protocol in the screening of ROP to improve the action and to avoid mistakes. Although individual Hospitals may adapt the protocol to their daily activity, it is recommended that there is a minimal working protocol agreed by most of professionals dedicated to pediatric ophthalmology in Spain.

[A protocol for the treatment of retinopathy of prematurity in Spain]. / Protocolo de tratamiento de la retinopatía del prematuro en España.

OBJECTIVE: To prepare a protocol for the treatment of retinopathy of prematurity (ROP) agreed by the majority of Spanish ophthalmologists dedicated to this topic. MATERIAL AND METHOD: A draft of the protocol was produced taking into account the experience of the participants and up to date publications. This draft was corrected by all the ophthalmologists participating in the project, and the final document was agreed by all of them. RESULTS: We present general guidelines as an aid for the treatment of ROP, including treatment criteria, treatment methods, a calendar of action, and follow-up. CONCLUSIONS: It is important to have a common working protocol for the treatment of ROP to improve care and to avoid mistakes. Although individual Hospitals may adapt the protocol to their daily activity, it is recommended that there is a minimal working protocol agreed by most of professionals dedicated to pediatric ophthalmology in Spain.

[Assessment of intra-operative techniques to prevent visual axis opacification in congenital cataract surgery]. / Valoración de técnicas intraoperatorias para la prevención de la opacificación del eje visual en la cirugía de cataratas congénitas.

OBJECTIVE: To evaluate the effectiveness of various surgical procedures in the management of posterior capsule and anterior vitreous on the prevention of visual axis opacification. SUBJECTS, MATERIAL AND METHODS: We retrospectively reviewed 120 eyes operated for unilateral congenital cataracts, with a median age at the time of cataract surgery of 21 months (interquartile range, 6-52 months). The eyes were divided into 3 groups: group 1 (eyes with intact posterior capsule, n=39), group 2 (eyes with posterior continuous curvilinear capsulorhexis, n=38), group 3 (eyes with posterior continuous curvilinear capsulorhexis and anterior vitrectomy, n=43). RESULTS: To determine the effect of posterior continuous curvilinear capsulorhexis on visual axis opacification we compared group 2 with group 1 (chi-square Pearson test, P=.281), therefore in this study the implementation of the posterior continuous curvilinear capsulorhexis did not show any decreases in the incidence of visual axis opacification. To study the effect of posterior continuous curvilinear capsulorhexis associated anterior vitrectomy, we compared group 3 with group 1 (chi-square Pearson test, P=.014), demonstrating that the combination of both techniques (posterior continuous curvilinear capsulorhexis and anterior vitrectomy) decreases the incidence of visual axis opacification. CONCLUSION: Posterior continuous curvilinear capsulorhexis as a single technique did not show any decrease in the incidence of visual axis opacification. Posterior continuous curvilinear capsulorhexis together with anterior vitrectomy are required to prevent visual axis opacification and to decrease reoperation rate.

[Tuberculosis in 34 patients with HIV infection]. / Tuberculosis en 34 pacientes con infección por VIH.

The clinical and microbiological finding of 34 patients with HIV infection and tuberculosis (30 were men), 32 were intravenous drug addicts. Fever, adenopathies, hepatomegaly and splenomegaly were the most encountered manifestations on admittance. 61.8% had a disseminated form of tuberculosis; the main locations were lymphatic (73.5%) and lung (64.7%). The detection of circulating viral antigen was associated with disseminated form of tuberculosis.