A novel fluorescent chemosensor allows the assessment of intracellular total magnesium in small samples

Remarkable features of a novel fluorescent Mg dye: high fluorescence intensity and intracellular retention.

Effects of whole body vibration plus diet on insulin-resistance in middle-aged obese subjects

We investigated the early effects of whole body vibration (WBV) added to hypocaloric diet on insulin-resistance and other parameters associated with glucose regulation in sedentary obese individuals. We randomly assigned 34 patients to WBV plus hypocaloric diet (WBV group) or diet alone (CON group) for 8 weeks. Fasting and post-load glucose, insulin, lipids, C-reactive protein, tumor necrosis factor-α, leptin, adiponectin were assessed. Insulin sensitivity index (ISI) was derived from oral-glucose-tolerance test. Body composition was evaluated with dual-energy X-ray absorptiometry. Both groups lost approximately 5% of weight, with greater reduction of body fat in WBV than in CON (-7.1±1.2 Kg vs. -5.3±1.0 Kg, p=0.003). Percent variation of ISI was more pronounced in WBV than in CON group (+35±4% vs. + 22±5%, p=0.002), accompanied by slight improvement in post-load glucose (-1.07±0.02 vs. - 0.12±0.01 mmol/l, p=0.031) but without changes in fasting levels. Adiponectin significantly increased in WBV group compared with CON (p=0.021 for comparison) whereas no differences in leptin and inflammatory markers were observed. In middle-aged sedentary obese subjects, WBV added to hypocaloric diet for 8 weeks improved body composition, insulin-resistance, glucose regulation and adiponectin levels to a greater extent compared with diet alone. Efficacy and feasibility of this approach in the long term need to be ascertained.

Stability of cachet phakic intraocular lens position during 6-months follow-up

Purpose:

To evaluate the position stability of a phakic intraocular lens (Cachet pIOL; Alcon, Laboratories, Inc., Fort Worth, TX) in the anterior chamber (AC) during a 6-months follow-up.

Methods:

Thirty eyes of 16 subjects underwent a Cachet pIOL implantation for the correction of high myopia from -6.50 to -16.00 D with plano targeted refraction. The position stability of the Cachet pIOL was evaluated using an Anterior Segment-OCT (AS-OCT, Carl Zeiss AG, Oberkochen, Germany) at 1- and 6-months postoperatively. Three measurements have been taken into account: 1) the minimum distance between the anterior surface of the Cachet pIOL optic disk and the central corneal endothelium; 2) the minimum distance between the optic disk’s edges of the pIOL and the endothelium; 3) the minimum distance between the posterior surface of the pIOL optic disk and the anterior surface of the crystalline lens. The endothelial cell density (ECD) was also recorded.

Results:

No statistically significant changes of the Cachet pIOL position in the AC were found during follow-up. The average changes were ≤0.1 mm between 1- and 6-months postoperatively (P>0.05). At the end of follow-up, The mean ECD loss was 0.7 % (from 2794 ± 337 cell/mm² to 2776 ± 388 cell/mm²; P>0.05).

Conclusion:

A high position stability of the Cachet pIOL in the anterior chamber was shown during a 6-months follow-up.

Adaptive optics retinal imaging--clinical opportunities and challenges

The array of therapeutic options available to clinicians for treating retinal disease is expanding. With these advances comes the need for better understanding of the etiology of these diseases on a cellular level as well as improved non-invasive tools for identifying the best candidates for given therapies and monitoring the efficacy of those therapies. While spectral domain optical coherence tomography offers a widely available tool for clinicians to assay the living retina, it suffers from poor lateral resolution due to the eye's monochromatic aberrations. Ophthalmic adaptive optics (AO) is a technique to compensate for the eye's aberrations and provide nearly diffraction-limited resolution. The result is the ability to visualize the living retina with cellular resolution. While AO is unquestionably a powerful research tool, many clinicians remain undecided on the clinical potential of AO imaging - putting many at a crossroads with respect to adoption of this technology. This review will briefly summarize the current state of AO retinal imaging, discuss current as well as future clinical applications of AO retinal imaging, and finally provide some discussion of research needs to facilitate more widespread clinical use.

Evaluation of femtosecond laser clear corneal incision: an experimental study

PURPOSE

To evaluate the changes of corneal topography following femtosecond laser and manual clear corneal incision (CCI).

METHODS

Inflation testing was performed in 14 human eye globes to evaluate the topographic response of the cornea to CCIs. In seven samples (femtosecond laser group), a 2.75-mm three-plane CCI was created using the iFS femtosecond laser (Abbott Medical Optics, Inc., Santa Ana, CA); the remaining seven samples (control group) received a 2.75-mm manual CCI using disposable angled knives. Topographic maps of the anterior and posterior cornea were acquired using a Scheimpflug topographer Pentacam HR (Oculus Optikgeräte GmbH, Wetzlar, Germany). Keratometric data were used to analyze the curvature changes of the cornea. The changes of corneal astigmatism were analyzed by vector analysis.

RESULTS

After CCI, the mean change of the anterior keratometric power was 0.04 ± 0.39 and 0.05 ± 0.51 diopters (D) (analysis of variance, P > .05) in the femtosecond laser and control groups, respectively. The mean change (P > .05) of the posterior corneal keratometric power was 0.16 ± 0.19 and 0.15 ± 0.18 D, respectively. The average change of the anterior and posterior corneal astigmatism vector magnitude was 0.17 D or less in both groups (P > .05). A slight against-the-rule astigmatic change of the anterior and posterior corneal interfaces was found after both CCI techniques.

CONCLUSION

The 2.75-mm three-plane CCI created with femtosecond laser showed minimal changes of the anterior and posterior corneal topography, comparable with those of single-plane angled manual incision.

[Looking for "lost occupational cancers": a systematic evaluation of occupational exposure in a case series of cutaneous squamous cell carcinomas in Italy]

BACKGROUND

Cutaneous carcinomas are tumors with a potential occupational etiology due to exposure to established carcinogens such as polycyclic aromatic hydrocarbons (PAH), ionizing radiation, ultraviolet (UV) radiation and arsenic. The occupational origin of such neoplasms is hugely underestimated in Italy.

OBJECTIVES

To asses the proportion of Squamous Cell Carcinomas (SCC) cases with a previous occupational exposure to carcinogens.

METHODS

We systematically evaluated occupational exposure in a series of consecutive cases, discharged in the period 2010-11 from the Dermatology Unit of Varese Hospital, Italy, with a histological diagnosis of SCC. Through a structured telephone interview we identified patients with a potential exposure to skin carcinogens. As a second-level step, an extensive evaluation by an occupational physician was performed to assess the occupational etiology in those selected cases.

RESULTS

105 patients were identified (65 men). 15 male cases out of a total of 85 patients who did the telephone interview, revealed a potential occupational exposure; 7 cases were confirmed as occupational cancers after second-level evaluation (proportion of male occupational cases = 13.2%). UV radiation and PAH were recognized as major causal agents. Applying those results to the national incidence data, we estimated a number of 700 annual occupational cases, 100-fold more than the cases currently evaluated by the Italian National Workers Compensation Authority.

CONCLUSIONS

Our results revealed that occupational SCC is still at present a substantially "lost disease" in Italy. Greater attention and enhanced collaboration between specialists is thus needed to overcome this tendency.

Eccentricity dependent changes of density, spacing and packing arrangement of parafoveal cones

PURPOSE

To investigate the distribution of cone density and spacing as well as the preferred packing arrangement of the cone mosaic as a function of retinal eccentricity.

METHODS

An adaptive optics retinal camera (rtx1, www.imagine-eyes.com) was used to obtain images of the parafoveal cone mosaic in nineteen healthy volunteers. Cone density and spacing were estimated for each subject (both eyes) using a sampling window of 80 × 80 pixels, at 250-, 450-, 650- and 1100-μm eccentricities from the fovea along the nasal and temporal retina of both eyes. The inter-subject and intra-subject variation of cone density and spacing were calculated via Coefficient of Variation (CoV). Cone packing arrangement was assessed using Voronoi analysis; calculations were done over 1024 × 128 pixels image sections of the cone mosaic across the horizontal meridian from 200- to 1050-μm eccentricities.

RESULTS

The inter-subject variation of parafoveal cone density ranged between 10% and 15% (p < 0.001) and the intra-subject variation of cone density was lower than 8% in all subjects, except for two. The cone spacing values showed a moderate inter-subject (CoV<7%; p < 0.001) and a low intra-subject variation (CoV<4% in all subjects, except for two cases). In the parafoveal region, 40-50% of cones were hexagonally arranged; the percentage of non-hexagonal Voronoi tiles increased at greater eccentricities.

CONCLUSION

The use of multiple and complementary metric descriptors allows for a more detailed description of packing distribution and preferred arrangement of cone photoreceptors across the parafoveal retina.

Influence of sampling window size and orientation on parafoveal cone packing density

We assessed the agreement between sampling windows of different size and orientation on packing density estimates in images of the parafoveal cone mosaic acquired using a flood-illumination adaptive optics retinal camera. Horizontal and vertical oriented sampling windows of different size (320x160 µm, 160x80 µm and 80x40 µm) were selected in two retinal locations along the horizontal meridian in one eye of ten subjects. At each location, cone density tended to decline with decreasing sampling area. Although the differences in cone density estimates were not statistically significant, Bland-Altman plots showed that the agreement between cone density estimated within the different sampling window conditions was moderate. The percentage of the preferred packing arrangements of cones by Voronoi tiles was slightly affected by window size and orientation. The results illustrated the high importance of specifying the size and orientation of the sampling window used to derive cone metric estimates to facilitate comparison of different studies.

Adaptive optics technology for high-resolution retinal imaging

Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have reviewed AO technology for retinal imaging, providing information on the core components of an AO retinal camera. The most commonly used wavefront sensing and correcting elements are discussed. Furthermore, we discuss current applications of AO imaging to a population of healthy adults and to the most frequent causes of blindness, including diabetic retinopathy, age-related macular degeneration and glaucoma. We conclude our work with a discussion on future clinical prospects for AO retinal imaging.

Optimal parameters to improve the interface quality of the flap bed in femtosecond laser-assisted laser in situ keratomileusis

PURPOSE

To analyze the interface quality of the anterior stroma after femtosecond laser flap creation using atomic force microscopy.

SETTING

IRCCS Fondazione G.B. Bietti, Rome, Italy.

DESIGN

Experimental study.

METHODS

A 110 μm depth flap was created in 20 human corneal tissues using a femtosecond laser platform (Intralase iFS). Tissues were divided into 4 groups of various cutting parameters: pulse energy and spot separation of 0.75 μJ and 6 μm (Group 1), 0.65 μJ and 5 μm (Group 2), 0.55 μJ and 4 μm (Group 3), and 0.45 μJ and 4 μm (Group 4). Four additional tissue sections were cut using a motorized microkeratome (Hansatome). Atomic force microscopy (Autoprobe CP) analysis was performed on the stromal bed of each sample.

RESULTS

The corneal tissues treated with higher pulse energies and wider spot separations (Groups 1 and 2) showed a rougher stromal bed interface (root mean square [RMS] rough = 0.23 μm ± 0.008 (SD) and 0.24 ± 0.009 μm, respectively) than tissues in Groups 3 and 4 (RMS rough = 0.18 ± 0.006 μm and 0.18 ± 0.008 μm, respectively; P<.001, 1-way analysis of variance). The stromal surface quality of tissues treated with pulse energies of 0.55 μJ or lower and 4 μm spot separation compared favorably with that of tissues cut by the microkeratome (RMS rough = 0.17 ± 0.006 μm; P>.05, Tukey).

CONCLUSIONS

The femtosecond stromal interface quality was improved with pulse energy lower and spot separations narrower than those currently used in the clinical setting. The flap interface smoothness created by the femtosecond laser was comparable to that created by the microkeratome.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

R-CVP versus R-CHOP versus R-FM as first-line therapy for advanced-stage follicular lymphoma: Final results of FOLL05 trial from the Fondazione Italiana Linfomi (FIL)

8006

Background: The optimal chemotherapy regimen for patients with advanced, active follicular lymphoma (FL) has not been established yet. We conducted a randomized trial comparing R-CVP with R-CHOP and R-FM. Methods: Previously untreated patients with advanced FL were randomly assigned to receive 8 doses of rituximab associated to 8 cycles of CVP, or 6 cycles of CHOP or FM (fludarabine 25 mg/m2 day 1-3, mitoxantrone 10 mg/m2 day 1). No maintenance therapy was allowed. The principal study end point was Time to Treatment Failure (TTF). Events in TTF were failure of induction therapy, progressive or relapse disease and death from any causes. In order to show a hazard ratio between each experimental arms and standard arm of 0.53 we planned to accrue 534 patients (178 per arm) with 4 years of accrual and 1 year of follow-up. Statistical tests were two-sided with an alpha error of 0.05, adjusted by Bonferroni for multiple arm comparison, and power of 90%. Results: Between March 2006 and September 2010, 534 patients were enrolled; 30 were subsequently excluded due to violation of inclusion criteria. Median patient age was 56 years (range 30-75), 63% of patients had stage IV disease, 37% had 3-5 FLIPI and 27% 3-5 FLIPI2 scores. At the end of induction treatment the overall response rate (CR+ PR) for the whole group was 91% (p=0.247). After a median follow-up of 34 months 208 events for TTF were recorded; 3-year TTF was 46%, 64% and 61% for patients treated with R-CVP, R-CHOP and R-FM respectively (R-CHOP vs R-CVP p=0.007; R-FM vs R-CVP p=0.021; R-FM vs R-CHOP p=0.969). The 3-year overall survival rate (OS) was 98%, 95% and 93% for R-CVP, R-CHOP and R-FM group, respectively (P=NS). Patients treated with R-FM had a higher rate of g III-IV neutropenia (64% vs 28% R-CVP, p<0.001; and vs 50% R-CHOP, p=0.015). During follow-up second malignancies were registered as late events in 23 patients (2%, 3% and 8% in R-CVP, R-CHOP and R-FM, respectively). Conclusions: This trial showed that R-CVP was associated with an inferior 3-year TTF and PFS compared with R-FM and R-CHOP. OS was similar among study arms but R-FM showed a higher rate of secondary tumors.

Biomechanics of the anterior human corneal tissue investigated with atomic force microscopy

PURPOSE

To investigate the biomechanics of the anterior human corneal stroma using atomic force microscopy (AFM).

METHODS

AFM measurements were performed in liquid on the anterior stroma of human corneas, after gently removing the epithelium, using an atomic force microscope in the force spectroscopy mode. Rectangular silicon cantilevers with tip radius of 10 nm and spring elastic constants of 25- and 33-N/m were used. Each specimen was subjected to increasing loads up to a maximum of 2.7 μN with scan speeds ranging between 3- and 95-μm/s. The anterior stromal hysteresis during the extension-retraction cycle was quantified as a function of the application load and scan rate. The elastic modulus of the anterior stroma was determined by fitting force curve data to the Sneddon model.

RESULTS

The anterior stroma exhibited significant viscoelasticity at micrometric level: asymmetry in the curve loading-unloading response with considerable hysteresis dependent both on the application load and scan rate (P < 0.01). The mean elastic modulus ranged between 1.14 and 2.63 MPa and was constant over the range of indentation depths between 1.0 and 2.7 μm in the stroma.

CONCLUSIONS

At microscale level, the mechanical response of the most anterior stroma is complex and nonlinear. The microstructure (fibers' packing, number of cross-links, water content) and the combination of elastic (collagen fibers) and viscous (matrix) components of the tissue influence the type of viscoelastic response. Efforts in modeling the biomechanics of human corneal tissue at micrometric level are needed.

Increased variance in germline allele-specific expression of APC associates with colorectal cancer

BACKGROUND & AIMS

Germline variations in allele-specific expression (ASE) are associated with highly penetrant familial cancers, but their role in common sporadic cancers is unclear. ASE of adenomatous polyposis coli (APC) is associated with pathogenesis of familial adenomatous polyposis. We investigated whether moderate variations in ASE of APC contribute to common forms of colorectal cancer (CRC).

METHODS

Denaturing high-performance liquid chromatography was used to analyze germline ASE of APC in blood samples from patients with CRC (cases, n = 53) and controls (n = 68). Means, medians, and variances of ASE were compared. Variants in the APC gene region also were analyzed.

RESULTS

The distribution of ASE differed significantly between groups; cases had significantly larger amounts of variance than controls (P = .0004). Risk for CRC increased proportionally with the degree of deviation from the mean. The odds ratio for individuals with levels of ASE that deviated more than 1 standard deviation from the mean was 3.97 (95% confidence interval, 1.71-9.24; P = .001); for those with levels greater than 1.645 standard deviations, the odds ratio was 13.46 (95% confidence interval, 1.76-609.40; P = .005). Sequence analysis revealed that a patient with a high level of ASE who did not have a family history of CRC carried a nonsense mutation in APC (p.Arg216X). Genotype analysis of APC associated multiple single-nucleotide polymorphisms with ASE values and/or variance among cases, but not controls. Cis variants, therefore, might account for some of the variance in ASE of APC.

CONCLUSIONS

Patients with CRC have a larger variance in germline levels of ASE in APC than controls; large distances from the mean ASE were associated with risk for common forms of CRC.