Forward electrohydrodynamic inkjet printing of optical microlenses on microfluidic devices

We report a novel method for direct printing of viscous polymers based on a pyro-electrohydrodynamic repulsion system capable of overcoming limitations on the material type, geometry and thickness of the receiving substrate. In fact, the results demonstrate that high viscosity polymers can be easily manipulated for optical functionalizing of lab-on-a-chip devices through demonstration of direct printing of polymer microlenses onto microfluidic chips and optical fibre terminations. The present system has great potential for applications from biomolecules to nano-electronics. Moreover, in order to prove the effectiveness of the system, the optical performance of such microlenses has been characterized by testing their imaging capabilities when the fibroblast cells were allowed to flow inside the microfluidic channel, showing one of their possible applications on-board a LoC platform.

Maxillofacial trauma in the emergency department: pearls and pitfalls in airway management

Maxillofacial trauma poses a challenge for the anesthesiologist because injuries can often compromise the patient's airways. Airway maintenance is the first step in the American College of Surgeons Advance Trauma Life Support (ATLS®) protocol. However, clinical dilemmas may arise about the best way to manage a potentially life-threatening injury. There are no recommendations about the best time to intubate, the warning signs for deciding to intubate, or which device should be used when difficulty is expected. In this context the ATLS® approach is important but not sufficient. It is also necessary to recognize and be able to manage specific problems in this scenario where clinical priorities may be conflicting, may suddenly change or may be hidden. This clinical review discusses the complexity of this scenario, providing an overview of the conditions at greatest risk for airway obstruction and the options for airway management, on the basis of the recent literature. Clinicians must recognize the milestones and pitfalls of this topic in order to adopt a systematic approach for airway management, to identify specific characteristics associated with it, and to establish the utility of different instruments for airway management.

Early outcome of liver transplantation performed with organs procured from brain death donors with transient or sustained cardio-circulatory collapse

BACKGROUND

Aim of this study was to compare early graft function after transplantation of recipients transplanted with livers procured from donors after brain death who experienced transient or sustained cardio-circulatory collapse.

METHODS

We retrospectively analysed patients who underwent liver transplantation (LTx) at our Institution from January 2010 to May 2012. Recipients were divided into 3 groups: those who received livers from brain death donors who experienced reversible cardio-circulatory arrest before organ procurement (RCA); those who experienced sustained cardio-circulatory collapse, treated with extra-corporeal membrane oxygenation support as rescue therapy of refractory cardiogenic shock (ECMO). Standard donors were considered as reference group (REF). Postoperative graft function, Primary Non-Function (PNF), and complications during the first 30 days were analysed.

RESULTS

102 LTx were analysed (76 REF, 22 RCA and 4 ECMO). The main cause of donor's death was post-anoxic coma in RCA and ECMO, cerebrovascular accident in REF. SGOT in REF, RCA, and ECMO donors were 27 [17-43], 54 [34-92], 716 [190-962] respectively, SGPT 17 [12-34], 46 [27-73], 84 [51-175] UI/L respectively, both P<0.01. All recipients had similar SGOT (P=0.48), SGPT (P=0.75) and Model for End-Stage Liver Disease scores (P=0.98) before LTx; similar graft cold and warm ischemia time and serum lactate levels at the end of surgery. After LTx, Intensive Care Unit stay and the incidence of PNF were similar.

CONCLUSION

The use of livers procured from donors after brain death that experienced transient or sustained cardio-circulatory collapse was associated with early graft function comparable to that of standard donors.

Active accumulation of very diluted biomolecules by nano-dispensing for easy detection below the femtomolar range

Highly sensitive detection of biomolecules is of paramount interest in many fields including biomedicine, safety and eco-pollution. Conventional analyses use well-established techniques with detection limits ~1 pM. Here we propose a pyro-concentrator able to accumulate biomolecules directly onto a conventional binding surface. The operation principle is relatively simple but very effective. Tiny droplets are drawn pyro-electro-dynamically and released onto a specific site, thus increasing the sensitivity. The reliability of the technique is demonstrated in case of labelled oligonucleotides diluted serially. The results show the possibility to detect very diluted oligonucleotides, down to a few hundreds of attomoles. Excellent results are shown also in case of a sample of clinical interest, the gliadin, where a 60-fold improved detection limit is reached, compared with standard ELISA. This method could open the way to a mass-based technology for sensing molecules at very low concentrations, in environmental as well as in diagnostics applications.

A mutation in PAK3 with a dual molecular effect deregulates the RAS/MAPK pathway and drives an X-linked syndromic phenotype

Loss-of-function mutations in PAK3 contribute to non-syndromic X-linked intellectual disability (NS-XLID) by affecting dendritic spine density and morphology. Linkage analysis in a three-generation family with affected males showing ID, agenesis of corpus callosum, cerebellar hypoplasia, microcephaly and ichthyosis, revealed a candidate disease locus in Xq21.33q24 encompassing over 280 genes. Subsequent to sequencing all coding exons of the X chromosome, we identified a single novel variant within the linkage region, affecting a conserved codon of PAK3. Biochemical studies showed that, similar to previous NS-XLID-associated lesions, the predicted amino acid substitution (Lys389Asn) abolished the kinase activity of PAK3. In addition, the introduced residue conferred a dominant-negative function to the protein that drives the syndromic phenotype. Using a combination of in vitro and in vivo studies in zebrafish embryos, we show that PAK3(N389) escapes its physiologic degradation and is able to perturb MAPK signaling via an uncontrolled kinase-independent function, which in turn leads to alterations of cerebral and craniofacial structures in vivo. Our data expand the spectrum of phenotypes associated with PAK3 mutations, characterize a novel mechanism resulting in a dual molecular effect of the same mutation with a complex PAK3 functional deregulation and provide evidence for a direct functional impact of aberrant PAK3 function on MAPK signaling.

Spontaneous assembly of carbon-based chains in polymer matrixes through surface charge templates

Stable chains of carbon-based nanoparticles were formed directly in polymer matrixes through an electrode-free approach. Spontaneous surface charges were generated pyroelectrically onto functionalized ferroelectric crystals, enabling the formation of electric field gradients that triggered the dipole-dipole interactions responsible for the alignment of the particles, while embedded in the polymer solution. The phenomenon is similar to the dielectrophoretic alignment of carbon nanotubes reported in the literature. However, here the electric fields are generated spontaneously by a simple heat treatment that, simultaneously, aligns the particles and provides the energy necessary for curing the host polymer. The result is a polymer sheet reinforced with well-aligned chains of carbon-based particles, avoiding the invasive implementation of appropriate electrodes and circuits. Because polymers with anisotropic features are of great interest for enhancing the thermal and/or the electrical conductivity, the electrode-free nature of this technique would improve the scaling down and the versatility of those interconnections that find applications in many fields, such as electronics, sensors, and biomedicine. Theoretical simulations of the interactions between the particles and the charge templates were implemented and appear in good agreement with the experimental results. The chain formation was characterized by controlling different parameters, including surface charge configuration, particle concentration, and polymer viscosity, thus demonstrating the reliability of the technique. Moreover, micro-Raman spectroscopy and scanning electron microscopy were used for a thorough inspection of the assembled chains.

Mechanistic evaluation of the transfection barriers involved in lipid-mediated gene delivery: interplay between nanostructure and composition

Here we present a quantitative mechanism-based investigation aimed at comparing the cell uptake, intracellular trafficking, endosomal escape and final fate of lipoplexes and lipid-protamine/deoxyribonucleic acid (DNA) (LPD) nanoparticles (NPs) in living Chinese hamster ovary (CHO) cells. As a model, two lipid formulations were used for comparison. The first formulation is made of the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) and the zwitterionic lipid dioleoylphosphocholine (DOPC), while the second mixture is made of the cationic 3β-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and the zwitterionic helper lipid dioleoylphosphatidylethanolamine (DOPE). Our findings indicate that lipoplexes are efficiently taken up through fluid-phase macropinocytosis, while a less efficient uptake of LPD NPs occurs through a combination of both macropinocytosis and clathrin-dependent pathways. Inside the cell, both lipoplexes and LPD NPs are actively transported towards the cell nucleus, as quantitatively addressed by spatio-temporal image correlation spectroscopy (STICS). For each lipid formulation, LPD NPs escape from endosomes more efficiently than lipoplexes. When cells were treated with DOTAP-DOPC-containing systems the majority of the DNA was trapped in the lysosome compartment, suggesting that extensive lysosomal degradation was the rate-limiting factors in DOTAP-DOPC-mediated transfection. On the other side, escape from endosomes is large for DC-Chol-DOPE-containing systems most likely due to DOPE and cholesterol-like molecules, which are able to destabilize the endosomal membrane. The lipid-dependent and structure-dependent enhancement of transfection activity suggests that DNA is delivered to the nucleus synergistically: the process requires both the membrane-fusogenic activity of the nanocarrier envelope and the employment of lipid species with intrinsic endosomal rupture ability.

Graded-size microlens array by the pyro-electrohydrodynamic continuous printing method

In the present work, the pyro-electrohydrodynamic technique was used for the realization of tunable-size microlens arrays. Poly(methyl methacrylate) dissolved in different solvent mixtures was used as the polymeric material for the realization of the microstructures. By controlling the experimental parameters and in particular, the volume of the drop reservoir, graded-size square arrays of tens of microlenses with focal length in the range 1.5-3 mm were produced. Moreover, the optical quality and geometrical features were investigated by profilometric and interferometric analysis.

Noninvasive ventilation in chest trauma: systematic review and meta-analysis

PURPOSE

Single studies of Noninvasive Ventilation (NIV) in the management of acute respiratory failure in chest trauma patients have produced controversial findings. The aim of this study is to critically review the literature to investigate whether NIV reduces mortality, intubation rate, length of stay and complications in patients with chest trauma, compared to standard therapy.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials, prospective and retrospective observational studies, by searching PubMed, EMBASE and bibliographies of articles retrieved. We screened for relevance studies that enrolled adults with chest trauma who developed mild to severe acute respiratory failure and were treated with NIV. We included studies reporting at least one clinical outcome of interest to perform a meta-analysis.

RESULTS

Ten studies (368 patients) met the inclusion criteria and were included for the meta-analysis. Five studies (219 patients) reported mortality and results were quite homogeneous across studies, with a summary relative risk for patients treated with NIV compared with standard care (oxygen therapy and invasive mechanical ventilation) of 0.26 (95 % confidence interval 0.09-0.71, p = 0.003). There was no advantage in mortality of continuous positive airway pressure over noninvasive pressure support ventilation. NIV significantly increased arterial oxygenation and was associated with a significant reduction in intubation rate, in the incidence of overall complications and infections.

CONCLUSIONS

These results suggest that NIV could be useful in the management of acute respiratory failure due to chest trauma.

Preoperative changes of forced vital capacity due to body position do not correlate with postoperative respiratory function in obese subjects

BACKGROUND

Obese patients are at risk of developing postoperative pulmonary complications. We hypothesized that preoperative changes in dynamic spirometry due to body posture would correlate with the drop of forced vital capacity (FVC) measured early after surgery.

METHODS

Thirty consecutive morbidly obese patients undergoing gastric banding were investigated. All subjects were studied the day before surgery (T0) and on postoperative day one (T1). Forced Vital Capacity (FVC) was measured, together with heart rate, mean arterial pressure and respiratory rate. At T0 measurements were taken in a random fashion with subjects in upright and in supine position. Subjects were then investigated after surgery in the supine position (T1). Postoperative pain was assessed at T1 using visual analogue scale. Intraoperative variables were also collected.

RESULTS

Body Mass Index (BMI) of the investigated subjects was 43.9 ± 5.7 Kg/m2 (range 33.8-60); their age was 40 ± 8 years. All dynamic spirometric data decreased significantly from upright to supine position (P<0.05) and after surgery from 3.07 L (2.77-3.71) to 1.50 (1.15-2.12) (FVC T0 supine vs. T1, P<0.05). Changes of FVC due to body position did not correlate with changes of FVC occurring after surgery (R2=0.105, P=0.081). When subjects were stratified by the median postoperative drop of FVC (45.74%), preoperative (anthropometric and spirometric data), intraoperative (ventilatory settings and hemodynamics) and postoperative (FVC and pain) parameters were similar between groups. The duration of pneumoperitoneum was correlated with the drop of FVC (R2=0.551, P<0.05).

CONCLUSION

The derangement of FVC that occurs in obese subjects after gastric banding is not predictable before surgery from anthropometric or spirometric data. The duration of pneumoperitoneum significantly contributes to postoperative impairment of respiratory function.

Quantitative measurement of intracellular transport of nanocarriers by spatio-temporal image correlation spectroscopy

Spatio-temporal image correlation spectroscopy (STICS) is a powerful technique for assessing the nature of particle motion in complex systems although it has been rarely used to investigate the intracellular dynamics of nanocarriers so far. Here we introduce a method to characterize the mode of motion of nanocarriers and to quantify their transport parameters on different length scales from single-cell to subcellular level. Using this strategy we were able to study the mechanisms responsible for the intracellular transport of DOTAP-DOPC/DNA and DC-Chol-DOPE/DNA lipoplexes in CHO-K1 live cells. Measurement of both diffusion coefficients and velocity vectors (magnitude and direction) averaged over regions of the cell revealed the presence of distinct modes of motion. Lipoplexes diffused slowly on the cell surface (diffusion coefficient, D ≈ 0.003 µm²/s). In the cytosol, the lipoplexes' motion was characterized by active transport with average velocity ν ≈ 0.03 µm/s and random motion. The method permitted us to generate intracellular transport map showing several regions of concerted motion of lipoplexes.

[Epidemiology and treatment of cryptorchidism and retractile testis: retrospective study in the area of Naples]

AIM

The authors report the results of a retrospective study carried out with family pediatricians (PDF) in the area of Naples to verify the epidemiology of cryptorchidism and retractile testis, the therapeutic strategy adopted and to assess whether they were in agreement with the data of the scientific literature.

METHODS

The study enrolled 6880 children, aged between 0-14 years, till March 2007; among those were recruited the patients with a diagnosis of cryptorchid and/or retractile testis. A patient schedule was completed with the affected side or bilaterality, age at diagnosis, type of treatment and the number of ascent retractile testis.

RESULTS

A purely descriptive analysis of the data was carried out: 81 patients were diagnosed with cryptorchid patients (1.18%) and 116 with retractile testis (1.68%). In 11 cases an ascent testicle was detected (9.48%). Forty-nine of the 81 cryptorchid patients (60.49%) were diagnosed in the age group of 0-2 years, 25 (30.86%) between 2-4 years and 7 (8.64 %) between 4-8 years. The hormonal therapy associated with surgery was mainly adopted in cryptorchid patients (35 patients).

CONCLUSION

The incidence of cryptorchidism in the area of Naples (1.18%) has not changed significantly. Only 60.49% of patients have been treated in an appropriate age group (0-2 years). The survey confirms the need to follow up the retractile testes for the possibility of definitive ascent in the inguinal canal. The study highlights the need for early diagnosis and treatment of this disease.

Extracorporeal lung perfusion and ventilation to improve donor lung function and increase the number of organs available for transplantation

INTRODUCTION

Ex vivo lung perfusion (EVLP) has been validated as a valuable technique to increase the pool of organs available for lung transplantation.

MATERIAL AND METHODS

After a preclinical experience, we obtained permission from the Ethics Committee of our institution to transplant lungs after EVLP reconditioning. ABO compatibility, size match, and donor arterial oxygen pressure (PaO(2))/fraction of inspired oxygen (FiO(2)) ≤ 300 mm Hg were considered to be inclusion criteria, whereas the presence of chest trauma and lung contusion, evidence of gastric content aspiration, pneumonia, sepsis, or systemic disease were exclusion criteria. We only considered subjects on an extra corporeal membrane oxygenation (ECMO) bridge to transplantation with rapid functional deterioration. Using Steen solution with packed red blood cells oxygenated with 21% O(2), 5% to 7% CO(2) was delivered, targeted with a blood flow of approximately 40% predicted cardiac output. Once normothermic, the lungs were ventilated with a tidal volume of 7 mL/kg a PEEP of 5 cmH(2)O and a respiratory rate of 7 bpm. Lungs were considered to be suitable for transplantation if well oxygenated [P(v-a) O(2) > 350 mm Hg on FiO(2) 100%], in the absence of deterioration of pulmonary vascular resistance and lung mechanics over the perfusion time.

RESULTS

From March to September 2011, six lung transplantations were performed, including two with EVLP. The functional outcomes were similar between groups: at T72 posttransplantation, the median PaO(2)/FiO(2) were 306 mm Hg (range, 282 to 331 mm Hg) and 323 mm Hg (range, 270 to 396 mm Hg) (P = 1, EVLP versus conventional). Intensive care unit ICU and hospital length of stay were similar (P = .533 and P = .663, respectively) with no mortality at 60 days in both groups. EVLP donors were older (49 ± 6 y versus 21 ± 7 y, P < .05), less well oxygenated (184 ± 6 mm Hg versus 570 ± 30, P < .05), displaying higher Oto scores (9.5 ± 0.7 versus 1.7 ± 1.5, P < .05).

CONCLUSIONS

The first 6 months of the EVLP program allowed us to increase the number of organs available for transplantation with short-term outcomes comparable to conventional transplantations.

[Laparoscopic treatment of UPJ obstruction in ectopic pelvic kidneys in children]

AIMS

To assess the feasibility and safety of a laparoscopic approach to UPJ obstruction (UPJO) in ectopic pelvic kidneys.

MATERIAL AND METHODS

In a retrospective analysis we selected 14 children, aged 6 months to 17 years, 12 males, 2 females, who had been treated in our Department between January 2004 and June 2011. 9 patients presented ureteropelvic junction obstruction (in 3 cases pelvic stones coexisted) with normal/moderately reduced (> or = 25%) relative function at radionuclide scan (MAG3), 3 nonfunctioning kidneys associated or not to hypertension, 2 congenital hypo-dysplastic kidneys. The evaluation of each patient involved the medical history, ultrasound examination, VCUG, MAG3 diuresis renogram and MRI in some cases. Of the patients presenting UPJO, 5 underwent dismembered pyeloplasty with pyelolithotomy, if required, and 4 pelvic derotation with straightening of the uretero-pelvic junction. A previous cystoscopic placement of a Double J stent was utilized. This facilitated the identification and dissection around the pelvis. With the patient in Trendelenburg position we utilized an umbilical trocar and two trocar in the right and left iliac fossae; an additional trocar, when required, was inserted more cephalad on the midclavear line contralaterally to the lesion. The derotation of ureteropelvic junction was obtained by freeing the kidney's lower pole and by placing intraperitoneally the junction protected with a Double J stent. This was obtained by suturing the peritoneum behind the ureteropelvic junction resulting in a forward rotation of the major axis of the kidney and a straightening of the junction. The 5 patients presenting nonfunctioning ectopic kidneys underwent laparoscopic nephrectomy. While the removal of congenital hypoplasic kidneys resulted easy, the removal of nonfunctioning kidneys was more difficult due to their complex vascular situation and for the embryonic disposition.

RESULTS

The operating time varied between 40 to 200 minutes. No patient required conversion to open surgery. The hypertension resolved after nephrectomy in all cases. 2 cases of dismembered pyeloplasty required a placement of Double J stent due the recurrence of symptoms and ! patient is waiting for redo operation. The pelvic derotation showed an improvement of diuretic MAG3 renogram and the function remained stable and patiens are symptoms-free.

CONCLUSION

The UPJO in ectopic pelvic kidneys presents a large spectrum of presentation. The laparoscopic approach provides good surgical exposure, and operative times are acceptable compared to those of laparoscopic procedure in anatomically normal kidneys. It has also proved a very useful tool in the non-functioning kidney nephrectomy thank to the help of magnification in the identification of numerous aberrant vessels that are quite often found in the pelvic kidneys. The derotation of the pelvis seems a useful procedure in moderate obstruction even if a longer followup is needed.

Printing of polymer microlenses by a pyroelectrohydrodynamic dispensing approach

The investigation of a method for fabricating microlenses by a nozzle-free inkjet printing approach is reported. The new method, based on a pyroelectrohydrodynamic mechanism, is also able to dispense viscous liquids and to draw liquid phase drops directly from the reservoir. Specifically, by dispensing optical grade polymer dissolved in different solvent mixtures, microlenses were printed with a pattern defined directly through this deposition method. The reliability of the microlenses and the tunability of their focal properties were demonstrated through profilometric and inteferometric analyses.