Adhesion modification of neural stem cells induced by nanoscale ripple patterns

We have studied the influence of anisotropic nanopatterns (ripples) on the adhesion and morphology of mouse neural stem cells (C17.2) on glass substrates using cell viability assay, optical microscopy and atomic force microscopy. The ripples were produced by defocused ion beam sputtering with inert Ar ions, which physically remove atoms from the surface at the energy of 800 eV. The ripple periodicity (∼200 nm) is comparable to the thickness of the cytoplasmatic microspikes (filopodia) which link the stem cells to the substrate. All methods show that the cell adhesion is significantly lowered compared to the same type of cells on flat glass surfaces. Furthermore, the AFM analysis reveals that the filopodia tend to be trapped parallel or perpendicular to the ripples, which limits the spreading of the stem cell on the rippled substrate. This opens the perspective of controlling the micro-adhesion of stem cells and the orientation of their filopodia by tuning the anisotropic substrate morphology without chemical reactions occurring at the surface.

Manic episode associated with interferon alpha therapy: A case report

Interferon alpha is a cytokine with antiviral and antineoplastic action, which is commonly used for treatment of Hepatitis C and B, malignant melanoma, Kaposi's sarcoma, kidney cancer and certain hematologic diseases. It is well-known some of its neuropsychiatric symptoms such as depressive symptoms, cognitive impairment, chronic fatigue, dysphoria and anxiety, but there are also other less common like mania, psychotic symptoms and suicide risk that have been reported. These symptoms interfere in the quality of life very significantly, which at the end can affect treatment adherence.

We report a case of a 33-year-old man who was taken to the emergency department by his family referring nervousness, irritability, verbose, and insomnia during the last 5 days. The patient had not psychiatric history. He was diagnosed with a malignant melanoma stage III A a year ago which required to start interferon alpha treatment.

Patient and family tell that symptoms began after forgetting last interferon dose. In the psychopathology exploration, we could observe mood lability, delusion ideas of prosecution, which includes his entire family and autorreferentiality. In the emergency room the blood test, urine drug test and CT were normal.

During the admission, and in collaboration with the Oncology service, it was agreed the reintroduction and maintenance of interferon combined with olanzapine up to 30 mg/day and clonazepam up to 6 mg/day, which resulted in the resolution of symptoms in two weeks.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Central venous access device (CVAD) complications in Haemophilia with inhibitors undergoing immune tolerance induction: Lessons from the international immune tolerance study

INTRODUCTION

Central venous access devices (CVADs) are frequently required as stable long-lasting venous access in children with haemophilia, especially those requiring immune tolerance induction (ITI) for inhibitors. CVAD infection is one of the most frequently reported catheter-related complications in this patient population.

AIM

Detailed review of CVAD complications from the International ITI (I-ITI) study and analysis of potential risk factors for such complications.

METHODS

Retrospective analysis of prospectively obtained data from the I-ITI study primarily focused on CVAD-related complications.

RESULTS

A total of 115 children were recruited and 183 CVADs were placed in 99 subjects resulting in 121,206 CVAD-days observed on-study. A total of 124 CVAD infections were reported in 41 of 99 (41%) subjects with an overall infection rate of 0.94 per 1000 CVAD-days (interquartile ranges 0-1.7). A similar number of infections were observed in the two treatment arms (median: 2 and 3 in high dose and low dose respectively). Infections occurred more frequently in the presence of external catheters than with fully implanted catheters (P = 0.026). Infected patients were significantly younger at the time of CVAD insertion (median age: 22 vs. 25 months, P = 0.020). Patients with Gram-positive infections were also significantly younger than those with Gram-negative infections (median age: 17 vs. 25 months, P < 0.0001).

CONCLUSION

CVAD infection was the most common complication observed in children with severe haemophilia and inhibitors in the frame of the I-ITI study. Younger age at CVAD insertion and external CVAD were associated with higher risk for infection. ITI outcome was unaffected by CVAD infections.

Haemorrhagic complications with adenotonsillectomy in children and young adults with bleeding disorders

Haemorrhagic complications remain a challenge with surgical procedures in patients with bleeding disorders. In children and young adults, the most commonly performed surgeries are tonsillectomies and/or adenoidectomies. Adequate haemostasis in these patients with bleeding disorders is centred on comprehensive perioperative haemostatic support and dexterous surgical technique. The aim of this study was to assess postoperative bleeding complications with tonsillectomy and/or adenoidectomy in children and young adults with known bleeding disorders. Retrospective review of all patients aged <25 years with known bleeding disorders who underwent tonsillectomy and/or adenoidectomy at Mayo Clinic, Rochester MN between July 1992 and July 2012. In contrast to reported literature, we observed a higher rate of bleeding complications (10/19, 53%) despite aggressive haemostatic support and appropriate surgical techniques. Delayed bleeding (>24 h postoperatively) was more common than early bleeding; and recurrent bleeding was associated with older age. Children and young adults with haemorrhagic diatheses undergoing adenotonsillectomy are at a higher risk of delayed bleeding and require close monitoring with haemostatic support for a prolonged duration in the postoperative period. A uniform approach is needed to manage these patients perioperatively by establishing standard practice guidelines and ultimately reduce postsurgical bleeding complications.

External front instabilities induced by a shocked particle ring

The dispersion of a cylindrical particle ring by a blast or shock wave induces the formation of coherent structures which take the form of particle jets. A blast wave, issuing from the discharge of a planar shock wave at the exit of a conventional shock tube, is generated in the center of a granular medium ring initially confined inside a Hele-Shaw cell. With the present experimental setup, under impulsive acceleration, a solid particle-jet formation is observed in a quasi-two-dimensional configuration. The aim of the present investigation is to observe in detail the formation of very thin perturbations created around the external surface of the dispersed particle layer. By means of fast flow visualization with an appropriate recording window, we focus solely on the first instants during which the external particle ring becomes unstable. We find that the critical area of the destabilization of the external ring surface is constant regardless of the acceleration of the initial layer. Moreover, we observe in detail the external front perturbation wavelength, rendered dimensionless by the initial ring perimeter, and follow its evolution with the initial particle layer acceleration. We report this quantity to be constant regardless of the evolution of the initial particle layer acceleration. Finally, we can reasonably assert that external front perturbations depend solely on the material of the particles.

Solid-particle jet formation under shock-wave acceleration

When solid particles are impulsively dispersed by a shock wave, they develop a spatial distribution which takes the form of particle jets whose selection mechanism is still unidentified. The aim of the present experimental work is to study particle dispersal with fingering effects in an original quasi-two-dimensional experiment facility in order to accurately extract information. Shock and blast waves are generated in the carrier gas at the center of a granular medium ring initially confined inside a Hele-Shaw cell and impulsively accelerated. With the present experimental setup, the particle jet formation is clearly observed. From fast flow visualizations, we notice, in all instances, that the jets are initially generated inside the particle ring and thereafter expelled outward. This point has not been observed in three-dimensional experiments. We highlight that the number of jets is unsteady and decreases with time. For a fixed configuration, considering the very early times following the initial acceleration, the jet size selection is independent of the particle diameter. Moreover, the influence of the initial overpressure and the material density on the particle jet formation have been studied. It is shown that the wave number of particle jets increases with the overpressure and with the decrease of the material density. The normalized number of jets as a function of the initial ring acceleration shows a power law valid for all studied configurations involving various initial pressure ratios, particle sizes, and particle materials.