Corneal biomechanical properties in myopic and emmetropic children.

OBJECTIVE: The purpose of this study was to investigate the relationship between corneal biomechanics and ocular morphology in myopic children and adolescents. PATIENTS AND METHODS: The study included 170 right eyes, from 170 patients under the age of 18 years, who underwent a complete ophthalmologic examination, gathering the following data: spherical equivalent (SE) (under pharmacological cycloplegia), biomechanical parameters - corneal hysteresis (CH) and corneal resistance factor (CRF), structural parameters - axial length (AL) and central corneal thickness (CCT). RESULTS: The average age of the patients was 15.26 years old (55.29% girls, 44.70% boys). Out of the 170 eyes, 111 were myopic eyes and 59 were emmetropic. Myopic eyes had a significantly lower CH (p=0.001), CRF (p=0.002) and CCT (p=0.009), and higher AL (p<0.001) than emmetropic eyes. The AL and CCT were significantly higher in myopic males, compared to myopic females (p<0.001 and 0.001). In myopes, we found statistically significant negative correlations between AL and CH (Pearson's r=-0.218), CRF (r=-0.226) and also SE (r=-0.539), and positive between SE and either CH (r=0.193) or CRF (r=0.201). CONCLUSIONS: Corneal biomechanical properties are significantly related to myopia parameters in children.

Early initiation of direct anticoagulation after stroke in patients with atrial fibrillation.

BACKGROUND AND PURPOSE: The safety of early initiation of anticoagulant therapy in patients with ischaemic stroke related to atrial fibrillation (AF) is unknown. We investigated the safety of early initiation of direct oral anticoagulants (DOACs), vitamin K antagonists (VKAs) or no anticoagulation. METHODS: This observational, retrospective, single-centre study included consecutive patients with recent (<4 weeks) ischaemic stroke and AF. The primary outcome was the rate of major (intracranial and extracranial) bleeding in patients on different treatment schemes, i.e. DOACs, VKAs and not anticoagulated. We also investigated the rate of ischaemic cerebrovascular events and mortality. RESULTS: We included 959 consecutive patients with AF and ischaemic stroke followed up for an average of 16.1 days after the index event. A total of 559 out of 959 patients (58.3%) were anticoagulated with either VKAs (n = 259) or DOACs (n = 300). Anticoagulation was started after a mean of 7 ± 9.4 days in the DOAC group and 11.9 ± 19.7 days in the VKA group. Early initiation of any anticoagulant was not associated with an increased risk of any major bleeding [odds ratio (OR), 0.49; 95% confidence intervals (CI), 0.21-1.16] and in particular of intracranial bleeding (OR, 0.47; 95% CI, 0.17-1.29; P = 0.143) compared with no anticoagulation. In contrast to VKAs (OR, 0.78; 95% CI, 0.28-2.13), treatment with DOACs (OR, 0.32; 95% CI, 0.10-0.96) reduced the rate of major bleeding compared with no anticoagulation. Early recurrences of ischaemic stroke did not differ significantly among the three groups. CONCLUSIONS: Starting DOACs within a mean of 7 days after stroke appeared to be safe. Randomized controlled studies are needed to establish the added efficacy of starting anticoagulation early after stroke.

Synchrotron radiation X-ray phase micro-computed tomography as a new method to detect iron oxide nanoparticles in the brain.

PURPOSE: The purpose of this study was to introduce synchrotron radiation X-ray phase computed tomography (SR-PCT) as a new method of visualizing ultrasmall superparamagnetic particles of iron oxide (USPIO) distribution into the brains of mice with neuroinflammation. PROCEDURES: The sensitivity of the technique was assessed by performing back-to-back SR-PCT and magnetic resonance imaging (MRI) in mice stereotaxically injected with a range of USPIO concentrations. Eight mice with cerebral ischemia were then intravenously injected with USPIOs and imaged back-to-back with MRI and SR-PCT. RESULTS: SR-PCT proved sensitive enough to detect iron in nanomolar quantities. In stroke-induced animals, SR-PCT showed hyperintense areas in the regions of MR signal loss and immunostaining for macrophages. SR-PCT, moreover, identified brain anatomy as clearly as histology, without the need for sectioning or staining, with an examination time of 44 min per brain at an isotropic spatial resolution of 8 µm. CONCLUSION: SR-PCT has potential for cellular imaging in intact brain, with unequaled neuroanatomy.

Voltage-dependent capacitance of metallic nanoparticles at a liquid/liquid interface.

A theoretical model is described for the voltage-dependent capacitance across the interface between two immiscible electrolytic solutions that is partially or completely covered with nanoparticles. The model is based on the description of competitive contributions of electrical double layers at the free interface and around nanoparticles. The effect of different system parameters is rationalised, and theoretical predictions are shown to be in agreement with available experimental data. The model provides a route for the characterisation of nanoparticle layers at liquid/liquid interfaces using capacitance measurements.

Rare earth-cobalt hard magnetic nanoparticles and nanoflakes by high-energy milling.

High-energy ball milling has been shown to be a promising method for large-scale fabrication of rare earth-transition metal nanoparticles. In this work, we report crystallographically anisotropic SmCo(5), PrCo(5) and Sm(2)(Co, Fe)(17) nanoparticles (particle size smaller than 10 nm) obtained by surfactant-assisted ball milling and study their size and properties as a function of the milling conditions. By milling nanocrystalline precursor alloys, we obtained SmCo(5) platelets (flakes) approximately 100 nm thick with an aspect ratio as high as 10(2)-10(3). The unusual shape evolution of this brittle material is attributed to its increased plasticity in the nanocrystalline state. The nanoflakes are susceptible to re-crystallization annealing and exhibit a room-temperature coercivity of up to 19 kOe. The successful fabrication of rare earth-cobalt nanoparticles and ultra-thin flakes provides hope for the development of nanocomposite permanent magnets with an enhanced energy product.

Histopathologic aspects in microglandular hyperplasia of endocervix.

In this study we analysed 373 cases of microglandular hyperplasia of endocervix belonging to patients from the III-VII decades of life. Most of the lesions had the typic aspect of proliferation of small glandular lumen lined by endocervix type epithelium, with or without areas of basal proliferation or immature squamous metaplasia. In 8 cases the growing patterns were peculiar, with mucinous or florid aspects, three of the cases rising differential diagnosis problems with cervical carcinoma.

Histopathologic and immunohistochemical study in one case of cystadenoma of parotid gland becoming malignant.

Cystadenoma and cystadenocarcinoma of the salivary glands are rare tumors, approximately half of cases being diagnosed at the level of parotid. The studied tumor associated both benign and malign zones, with deep infiltrating character in the adjacent structures. In both areas the growing pattern was predominantly cystic and papillary, and the proliferated neoplastic cells were majority cubical or columnar, with low grade of nuclear pleomorphism in the becoming malign areas, discordant with the infiltrative character of the neoplasm. Immunohistochemically, we investigated the tumor with AE1-AE3, CEA, SMA, S-100 and PCNA.

[A peculiar mechanism of hydrocephalus: the "water-hammering" effect]. / Un mécanisme particulier d'hydrocéphalie: l'effet "coup de marteau".

BACKGROUND AND PURPOSE: Aneurysms of the basilar artery can cause hydrocephalus due to compression of the third ventricle or the sylvian aqueduct. The observation of a particular case led to discuss another possible mechanism of hydrocephalus. CLINICAL PRESENTATION AND RADIOLOGICAL STUDIES: An aneurysm of the basilar artery was revealed by an ischemic stroke in a 65-year-old man. Hydrocephalus developed during the following months. The MRI studies showed that it could not be explained merely by a permanent compression. However, the patient improved clearly after a ventriculo-peritoneal derivation. CONCLUSION: The hydrocephalus could be explained by a "water-hammering" effect due to the pulsating blood in the ectatic vessel, which created a cerebrospinal fluid outflow impairment through the third ventricle.

Media and methods for isolation of aeromonads from fecal specimens. A multilaboratory study.

An international multilaboratory study was conducted to establish the optimal combination of culture media, incubation time and temperature for recovery of aeromonads from stools using blood ampicillin (10 mg/l) agar (BAA), starch ampicillin (10 mg/l) agar (SAA), and cefsulodin irgasan novobiocin agar (CIN) with alkaline peptone water (APW) for enrichment. Optimal recovery of aeromonads (167/186) occurred using BAA (37 degrees C; 24 h) and CIN (25 degrees C; 48 h) with APW (25 degrees C; 24 h) subcultured to BAA (37 degrees C; 24 h) and CIN (25 degrees C; 48 h).