Eye muscle surgery for infantile nystagmus syndrome in the first two years of life

Purpose:

To report visual and elctrophysioloigcal effects of eye muscle surgery in young patients with infantile nystagmus syndrome (INS).

Methods:

Prospective, interventional case cohort of 19 patients aged under 24 months who were operated on for combinations of strabismus, an anomalous head posture, and nystagmus. All patients were followed at least nine months. Outcome measures, part of an institutionally approved study, included Teller acuity, head position, strabismic deviation, and eye movement recordings, from which waveform types and a nystagmus optimal foveation fraction (NOFF). Computerized parametric and nonparametric statistical analysis of data were perfomed using standard software on both individual and group data.

Results:

Age averaged 17.7 months (13.1-month follow-up). Thirteen (68%) patients had associated optic nerve or retinal disease. 42% had amblyopia, 68% had refractive errors. Group means in binocular Teller acuity (P < 0.05), strabismic deviation (P < 0.05), head posture (P < 0.001), and the NOFF measures (P < 0.01) from eye movement recordings improved in all patients. There was a change in null zone waveforms to more favorable jerk types. There were no reoperations or surgical complications.

Conclusions:

Surgery on the extraocular muscles in patients aged less than two years with INS results in improvements in multiple aspects of ocular motor and visual function.

Erythropoietin promotes neurological recovery after intracerebral haemorrhage in rats

BACKGROUND

Attention has turned to neurorestorative therapies, including erythropoietin, for experimental ischaemic stroke and head injury. Treatments for intracerebral haemorrhage need to be developed, as this represents a particularly devastating and common form of neurological injury. Aim The aim of this study is to investigate the therapeutic potential of erythropoietin after intracerebral haemorrhage in rats and to measure its effects on mechanisms of recovery and neurogenesis.

METHODS

Intracerebral haemorrhage was induced in 24 Wistar male rats by intrastriatal infusion of autologous blood. Recombinant human erythropoietin (5000 or 10,000 U/kg BW/day) or saline was administered starting 1 day after intracerebral haemorrhage and continued daily for 1 week (n=8 for each group). To label proliferating cells, 5'-bromo-2' deoxyuridine was injected daily for 13 days after intracerebral haemorrhage. All animals survived for 2 weeks after intracerebral haemorrhage. Functional outcome, area of tissue loss and immunohistochemical staining were measured at 14 days after intracerebral haemorrhage. Global test or anova was used to test the erythropoietin dose effect.

RESULTS

Rats receiving recombinant human erythropoietin after intracerebral haemorrhage exhibited significant improvement in modified neurological severity score and corner test at 14 days (P<0.05). Increased expression of phenotypes of synaptogenesis and proliferating immature neurons were shown by immunohistochemical staining. Only the group receiving a lower dose of recombinant human erythropoietin had significantly less tissue loss compared with the control group (P<0.05). In rats treated with recombinant human erythropoietin, double staining for 5'-bromo-2' deoxyuridine and TUJ1 revealed a subpopulation of cells that express an immature neuronal marker while still dividing.

CONCLUSIONS

Erythropoietin improves neurological outcome and increases histochemical parameters of neurogenesis when given after intracerebral haemorrhage in rats. Intriguingly, only the lower dose of recombinant human erythropoietin was effective in reducing tissue loss in the region of intracerebral haemorrhage.

MI-63: a novel small-molecule inhibitor targets MDM2 and induces apoptosis in embryonal and alveolar rhabdomyosarcoma cells with wild-type p53

Background:

Interruption of the role of p53s as a tumour suppressor by MDM2 may be one of the mechanisms by which cancer cells evade current therapy. Blocking the inhibition of wild-type p53 by MDM2 in cancer cells should reactivate p53's tumour suppressor functions and enhance current cancer treatments. MI-63 is a novel non-peptide small molecule that has shown strong binding affinity (K_i=3 nM) for MDM2; however, its effects on paediatric cancer cells and the specific mechanism of tumour suppressor reactivation have not been evaluated.

Methods:

Rhabdomyosarcoma (RMS), the most common childhood soft tissue sarcoma, expresses either wild-type or mutant p53 protein. We examined the inhibitory effects of MI-63 in embryonal RMS (ERMS) and alveolar RMS (ARMS) cell lines expressing wild-type or mutated p53.

Results:

Treatment with MI-63 reduced cell viability by 13.4% and by <1%, respectively, at 72 h in both RH36 and RH18 cell lines expressing wild-type p53. In contrast, RH30 and RD2 cells expressing p53 mutants are resistant to MI-63 treatment. An increased expression of p53, p21^WAF1, and Bax protein was observed after treatment with MI-63 in RMS cells with wild-type p53, and apoptosis was confirmed by cleaved PARP and caspase-3 expression. However, RD2 and RH30 RMS cells, as well as human normal skeletal muscle cells, showed a minimal increase in p53 signalling and no induction of cleaved PARP and caspase-3. MI-63 was compared with Nutlin-3, a known MDM2 inhibitor, and was found to be more potent in the inhibition of cell proliferation/viability. Further, synergy was observed when MI-63 was used in combination with doxorubicin.

Conclusion:

These results indicate that MI-63 is a potent therapeutic agent for RMS cells expressing wild-type p53 protein.

Characterization and merger of oscillatory mechanisms in an artificial genetic regulatory network

Regulatory molecular networks have numerous pharmacological and medical applications. The oscillatory mechanisms and the role of oscillations in these regulatory networks are not fully understood. In this paper, we explore two oscillatory mechanisms: the hysteresis-based relaxation oscillator and the repressilator. We combine these mechanisms into one regulatory network so that only two parameters, the strength of an additional regulatory connection and the timescale separation for one of the variables, control the transition from one mechanism to the other. Our data support a qualitative difference between the oscillatory mechanisms, but in the parameter space, we found a single oscillatory region, suggesting that the two mechanisms support each other. We examine interactions in a basic population: that is, a pair of the composite oscillators. We found that the relaxation oscillation mechanism is much more resistant to oscillatory death as the cells are diffusively coupled in a population. Additionally, stationary pattern formation has been found to accompany the relaxation oscillation but not the repressilator mechanism. These properties may guide the identification of oscillatory mechanisms in complex natural regulatory networks.

Fabrication of Anti-human Cardiac Troponin I Immunogold Nanorods for Sensing Acute Myocardial Damage

A facile, rapid, solution-phase method of detecting human cardiac troponin I for sensing myocardial damage has been described using gold nanorods-based biosensors. The sensing is demonstrated by the distinct change of the longitudinal surface plasmon resonance wavelength of the gold nanorods to specific antibody-antigen binding events. For a higher sensitivity, the aspect ratio of gold nanorods is increased up to ca 5.5 by simply adding small amount of HCl in seed-mediated growth solution. Experimental results show that the detecting limit of the present method is 10 ng/mL. Contrast tests reveal that these gold nanorods-based plasmonic biosensors hold much higher sensitivity than that of conventionally spherical gold nanoparticles.

Genetic variations in angiogenesis pathway genes associated with clinical outcome in localized gastric adenocarcinoma

BACKGROUND

Angiogenesis has been attributed to be a well-recognized aspect of human cancer biology. As such, proteinase-activated receptor (PAR)-1, endostatin (ES) and interleukin-8 (IL-8) mediate the regulation of early-onset angiogenesis and in turn impact the process of tumor-growth and disease progression.

PATIENTS AND METHODS

Formalin-fixed paraffin-embedded tissues were obtained from 137 patients with localized gastric cancer at University of Southern California and Memorial Sloan-Kettering Cancer Center medical facilities. DNA was extracted and genotyping was carried out using PCR-restriction fragment length polymorphism-based protocols.

RESULTS

In false discovery rate-adjusted univariate analysis, PAR-1 -506 ins/del (P < 0.001), ES +4349 G>A (P = 0.004), and IL-8 -251 T>A (P < 0.0001) were associated with time to tumor recurrence (TTR). Further, PAR-1 -506 ins/del and IL-8 -251 were associated with overall survival (OS). After adjusting for covariates, IL-8 remained significantly associated with TTR (adjusted P = 0.003) and OS (adjusted P = 0.049), whereas ES was significantly associated with TTR (adjusted P = 0.026).

CONCLUSIONS

Polymorphisms in PAR-1, ES, and IL-8 may serve as independent molecular prognostic markers in patients with localized gastric adenocarcinoma. The assessment of the patients' individual risk on the basis of interindividual genotypes may therefore help to identify patient subgroups at high risk for poor clinical outcome.

Large eddy simulation of fire-induced buoyancy driven plume dispersion in an urban street canyon under perpendicular wind flow

The dispersion of fire-induced buoyancy driven plume in and above an idealized street canyon of 18 m (width) x 18 m (height) x 40 m (length) with a wind flow perpendicular to its axis was investigated by Fire Dynamics Simulator (FDS), Large Eddy Simulation (LES). Former studies, such as that by Oka [T.R. Oke, Street design and urban canopy layer climate, Energy Build. 11 (1988) 103-113], Gayev and Savory [Y.A. Gayev, E. Savory, Influence of street obstructions on flow processes within street canyons. J. Wind Eng. Ind. Aerodyn. 82 (1999) 89-103], Xie et al. [S. Xie, Y. Zhang, L. Qi, X. Tang, Spatial distribution of traffic-related pollutant concentrations in street canyons. Atmos. Environ. 37 (2003) 3213-3224], Baker et al. [J. Baker, H. L. Walker, X. M. Cai, A study of the dispersion and transport of reactive pollutants in and above street canyons--a large eddy simulation, Atmos. Environ. 38 (2004) 6883-6892] and Baik et al. [J.-J. Baik, Y.-S. Kang, J.-J. Kim, Modeling reactive pollutant dispersion in an urban street canyon, Atmos. Environ. 41 (2007) 934-949], focus on the flow pattern and pollutant dispersion in the street canyon with no buoyancy effect. Results showed that with the increase of the wind flow velocity, the dispersion pattern of a buoyant plume fell into four regimes. When the wind flow velocity increased up to a certain critical level, the buoyancy driven upward rising plume was re-entrained back into the street canyon. This is a dangerous situation as the harmful fire smoke will accumulate to pollute the environment and thus threaten the safety of the people in the street canyon. This critical re-entrainment wind velocity, as an important parameter to be concerned, was further revealed to increase asymptotically with the heat/buoyancy release rate of the fire.

Exploring feature-based approaches in PET images for predicting cancer treatment outcomes

Accumulating evidence suggests that characteristics of pre-treatment FDG-PET could be used as prognostic factors to predict outcomes in different cancer sites. Current risk analyses are limited to visual assessment or direct uptake value measurements. We are investigating intensity-volume histogram metrics and shape and texture features extracted from PET images to predict patient's response to treatment. These approaches were demonstrated using datasets from cervix and head and neck cancers, where AUC of 0.76 and 1.0 were achieved, respectively. The preliminary results suggest that the proposed approaches could potentially provide better tools and discriminant power for utilizing functional imaging in clinical prognosis.

Development and validation of a digital head posture measuring system

PURPOSE

To report the accuracy and repeatability of a new digital head posture measuring system.

DESIGN

Prospective study, clinical laboratory investigation.

METHODS

The digital head posture measuring system consists of a head-mounted motion tracker, a standard personal computer, and customized software to sample and display 3-dimensional (3D) head posture in real-time. Using a mechanical head posture measuring device as a reference, 3D head positions of an artificial head and 12 human subjects were recorded with the digital head posture device. Accuracy of the digital device outputs, relationship between digital outputs and actual head rotations, and repeatability of the tests were analyzed.

RESULTS

The digital head posture device showed consistent outcomes when compared to the mechanical one. The digital outputs of 3D rotations are very close to actual artificial head and human head rotations. The correlation coefficients of the linear relationship between the digital outputs and actual head movements were greater than 0.99. Repeatability tests for the artificial head and human subjects for all 3D rotations had 95% limits of agreement angles less than +/-6 degrees and +/-8 degrees, respectively.

CONCLUSIONS

The digital head posture device is an acceptable device with high accuracy, repeatability, and validity in measuring head posture in 3 dimensions.