Fabrication of metal nanoparticle arrays by controlled decomposition of polymer particles

We report a novel fabrication method for ordered arrays of metal nanoparticles that exploits the uniform arrangement of polymer beads deposited as close-packed monolayers. In contrast to colloidal lithography that applies particles as masks, we used thermal decomposition of the metal-covered particles to precisely define metal structures. Large arrays of noble metal (Au, Ag, Pt) nanoparticles were produced in a three-step process on silicon, fused silica and sapphire substrates, demonstrating the generality of this approach. Polystyrene spheres with diameters ranging between 110 nm and 1 μm were convectively assembled into crystalline monolayers, coated with metal and annealed in a resistive furnace or using an ethanol flame. The thermal decomposition of the polymer microspheres converted the metal layer into particles arranged in hexagonal arrays that preserved the order of the original monolayer. Both the particle size and the interparticle distance were adjusted via the thickness of the metal coating and the sphere diameter, respectively.

Neurobehavioral abnormalities in a brain-specific NADPH-cytochrome P450 reductase knockout mouse model

The aim of the present study was to test a new hypothesis that brain cytochrome P450 reductase (CPR) and CPR-dependent enzymes play important roles in behavioral performance. A mouse model with brain neuron-specific deletion of the Cpr gene (brain-Cpr-null) was recently generated. Brain-Cpr-null mice and wild-type (WT) littermates were compared in a variety of behavioral assays. Notable differences were found in the exploratory behavior assay: for both males and females, activity in the center of the chamber was significantly higher for brain-Cpr-null than for WT mice on days 2 and 3 of the assay, although no significant difference was found between the two groups in anxiety-like behavior in the elevated zero maze. Furthermore, in the fear-conditioning assay, brain-Cpr-null mice exhibited significantly less activity suppression than did WT controls. This deficit in activity suppression was not accompanied by any difference between WT and brain-Cpr-null mice in nociceptive responses to foot shocks. Abnormal activity suppression was also observed in both male and female brain-Cpr-null mice during the contextual memory test. However, in the Morris water maze assay, the brain-Cpr-null and WT mice were indistinguishable, indicating normal spatial memory in the mutant mice. These data collectively indicate a novel role of the Cpr gene in fear conditioning and memory.

Polymorphism H558R in the Human Cardiac Sodium Channel SCN5A Gene is Associated with Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common sustained cardiac arrhythmias and its prevalence is increasing worldwide in line with the growing elderly population. Many single nucleotide polymorphisms and mutations are associated with AF, including the common loss-of-function histidine-558-to-arginine (H558R) polymorphism of the human cardiac sodium channel, voltage-gated, type V, α subunit (encoded by the SCN5A gene). The H558R polymorphism results from the T-C transition in the SCN5A gene. This study recruited 135 patients with AF and 296 healthy controls to scan for and perform targeted genotyping of the H558R polymorphism of the SCN5A gene. Logistic regression analysis showed that the TC and CC genotypes (i.e. genotypes that result in the R558 polymorphism) were significantly associated with an increased risk of developing AF. The R558 polymorphism conferred an odds ratio for AF of 3.451 (95% confidence interval 1.718, 6.931). In conclusion, this study provided evidence for the role of the H558R polymorphism of the SCN5A gene in increasing the susceptibility to AF.

Resistin-like molecule-β is a human airway remodelling mediator

Though implicated in vascular remodelling, a role for the resistin-like molecule (RELM)-β in human airway remodelling remains unexplored. We hypothesised that RELM-β expression is increased in the airways of asthmatics and regulates airways epithelial cell function. Expression of RELM-β in the bronchial mucosa and its concentrations in bronchoalveolar lavage (BAL) fluid from asthmatics and controls were measured by immunohistochemistry and ELISA, respectively. Proliferation assays, Western blotting, ELISA and real-time PCR were employed to detect effects of RELM-β on airways epithelial cells. RELM-β expression was increased in the bronchial mucosa and BAL fluid of asthmatics compared with controls. In the asthmatics, the numbers of mucosal RELM-β+ cells correlated inversely with forced expiratory volume in 1 s (r=-0.531, p=0.016), while the numbers of epithelial RELM-β+ cells correlated positively with those of mucin (MUC)5AC+ cells. In vitro, interleukin-13 enhanced RELM-β expression by primary human airways epithelial cells, while RELM-β itself acted on these cells to induce proliferation, expression of MUC5AC, extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK)-phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation and elevated expression of transforming growth factor-β2, epidermal growth factor and vascular endothelial growth factor. RELM-β has the potential to contribute to airway remodelling in diseases such as asthma by acting on epithelial cells to increase proliferation, mucin and growth factor production, at least partly via ERK/MAPK-PI3K/Akt signalling pathways.

Endovascular treatment of recurrent intracranial aneurysms with re-coiling or covered stents

OBJECTIVE

To report our experiences in the treatment of recurrent intracranial aneurysms with re-coiling or covered stents.

METHODS

A total of 291 patients with 305 intracranial aneurysms were treated with detachable coils, and 41 (28.9%) of 142 patients with aneurysms in the internal carotid artery had a recurrent aneurysm during the follow-up period. For this study, 31 recurrent aneurysms in 31 patients who had angiograms within 6 months following retreatment with detachable coils (group A, n = 20) or covered stents (group B, n = 11) were analysed. Aneurysms were categorised as complete or incomplete occlusion via angiographic assessment and graded as full recovery, improvement, no change or deterioration via clinical assessment. Data regarding technical success, initial and final angiographic results, mortality, morbidity and final clinical outcome were collected and analysed postoperatively.

RESULTS

Coil embolisation and covered stent placement were technically successful in all recurrent aneurysms. The initial angiographic results showed complete occlusion in 11 patients (55%) in group A and in eight (72.7%) in group B (p = 0.452), and the final angiographic results exhibited complete occlusion in 10 patients (50%) in group A and in 11 (100%) in group B (p = 0.005). There were no significant differences in technique success, mortality, culminate morbidity or final clinical outcome between the two groups.

CONCLUSIONS

Recurrent aneurysms after coiling can be successfully treated and occluded with re-coiling or covered stent placement. However, covered stents seem to be more effective than re-coiling with regard to complete occlusion of recurrent aneurysms.

Preparation of a SERS substrate and its sample-loading method for point-of-use application

A simple approach was demonstrated to prepare a silver (Ag) nanoparticle (NP) assembly as a SERS substrate. Just by dipping a flat silicon (Si) wafer into an aqueous deposition solution of hydrogen fluoride (HF) + silver nitrate (AgNO3), a monolayer of Ag NPs was uniformly deposited onto the Si wafer surface. In order to load the to-be-detected sample onto the as-prepared SERS substrate, three methods have been individually tested, (i) by incubating the SERS substrate in the sample solution, (ii) by dropping and drying a small volume of the sample solution (1-2 microl) onto the SERS substrate surface, or (iii) by directly introducing the sample into the deposition solution. The last approach was also employed to metalize a Si nanowire (NW). Due to the NW's highly curved surface, the Ag NPs self-assembled and aggregated along the NW with a close interdistance. The aggregated Ag NPs on the NW surface can also be used as a SERS substrate. The demonstrated approach holds the promise to prepare a fresh SERS substrate at the point-of-use with the sample already loaded to promptly collect the SERS signal for the field application.

Endovascular Treatment for Very Small Supraclinoid Aneurysms with Stent-Assisted Coiling. Long-Term Follow-up in Six Cases

SUMMARY

The endovascular treatment of very small aneurysms (lesions less than 3 mm in maximum diameter) with wide necks remains a challenge for saccular embolization. We retrospectively analyzed our data using Neuroform stent-assisted coiling for very small supraclinoid aneurysms with wide neck to evaluate the feasibility and efficacy of endovascular treatment of these lesions. We conducted a review of our experience and results of endovascular treatments in six patients with seven very small aneurysms. All aneurysms were located at the side wall of the supraclinoid segment of the ICA. They were ruptured in two patients and unruptured in four. The technique of stent-assisted coiling was used in all cases with coiling before stenting and additional coils after deployment of the stent in the same session. All patients were successfully embolized with stent-assisted coiling. The coils were introduced into the lumen for subtotal occlusion in five aneurysms and for partial occlusion in two. During one to two years follow-up angiography, all aneurysms were completely occluded and no recurrence occurred. No complications were observed. Endovascular stent-assisted coil embolization of supraclinoid very small aneurysms with wide necks is effective and feasible. Subtotal aneurysm occlusion might progress to total occlusion.

The treatment of femoral neuropathy due to pseudotumour caused by metal-on-metal resurfacing arthroplasty

Concerns now exist about the long-term biological effects of exposure to orthopaedic metal alloys, particularly serum cobalt and chromium ions derived from metal-on-metal wear debris in these patients. A pseudotumour mass complicating metal-on-metal resurfacing arthroplasty has been recognized by orthopaedic oncologists and specialist hip units. Pseudotumours may also present with a major nerve palsy. Two cases of femoral neuropathy due to pseudotumour masses caused by metal-on-metal resurfacing arthroplasty are presented. Preoperative neurophysiological studies showed severe and irreversible pathological changes to nerve function with neurohistopathological evidence of complete nerve destruction with a previously unreported pathological appearance. This may represent a previously unrecognized pathological process, possibly 'toxic' in nature, resulting from metal-on-metal wear debris. Prolonged follow-up and detailed clinical assessment of patients after hip resurfacing arthroplasty is advocated with planned and expeditious revision of any patient in whom evidence of femoral neuropathy develops.

The --1019 C/G polymorphism of the 5-HT(1)A receptor gene is associated with negative symptom response to risperidone treatment in schizophrenia patients

The application of pharmacogenetics is currently one of the most promising developments in anti-psychotic treatment and is attracting more and more attention. Although risperidone belongs to the first-line atypical anti-psychotics, there have been relatively few risperidone pharmacogenetic studies, especially in Asian populations. We investigated the relationship between the C825T polymorphism of GBN3 (rs5443) and the -1019 C/G polymorphism of 5-HT(1)A (rs6295) and response to risperidone treatment. One-hundred and thirty schizophrenia patients were recruited. They were treated with risperidone monotherapy for eight weeks. Clinical response was assessed on the Positive and Negative Syndrome Scale (PANSS) on the day of admission and was subsequently assessed after eight weeks following the treatment. Patients were genotyped for two functional polymorphisms: C825T of GBN3 (rs5443) and -1019 C/G of HT(1)A (rs6295). Association tests between genotypes and percentage improvement in total PANSS scores, as well as positive symptom scores and negative symptom scores, were performed using analyses of variance (ANOVA). The -1019 C/G polymorphism of HT(1)A (rs6295) was associated with negative symptom response to treatment. Patients with the CC genotype showed substantial improvement as regards negative symptom response (F = 4.177, df = 2, P = 0.019), compared with the patients with the CG and GG genotypes. No association was observed between C825T of GBN3 (rs5443) and changes in PANSS scores. The results suggest that the -1019 C/G polymorphism (rs6295) in the 5-HT(1)A gene may be a useful predictor of reduction in negative symptoms in schizophrenic patients treated with risperidone.

Endovascular Treatment of a High-Flow Direct Traumatic Carotid Cavernous Fistula with a Two Year Follow-up

SUMMARY

Endovascular treatment of high-flow direct traumatic carotid cavernous fistula (CCF) carries many difficulties. One of them is that carotid dissection may be associated with pseudo- aneurysm formation even when the CCF can be successfully embolized by detachable balloons. This article details a unique technique of treating pseudo-aneurysm by obstructing the lumen with preservation of the parent artery. The case presented here involves a 50-yearold man with a history of severe trauma. The angiography revealed that his bilateral highflow carotid cavernous fistula was successfully embolized by detachable balloons and control digital subtraction angiography at the end of the procedure demonstrated the fistula closed and the internal carotid artery preserved. But two months later, a pseudo-aneurysm formed in the right internal carotid artery. Under endovascular treatment along with other techniques including coils, stent-assisted and covered stent, the pseudo-aneurysm was excluded with preserved ICA. Two years later, the fistula and pseudo-aneurysm both disappeared quietly without patent foreign body reaction in the parent arterial wall.

The feasibility and efficacy of treatment with a Willis covered stent in recurrent intracranial aneurysms after coiling

BACKGROUND AND PURPOSE

Aneurysm recurrence is an innate problem after coiling, and the recurrence rate is higher in complicated aneurysms. We evaluated the feasibility and efficacy of using the Willis covered stent in treating recurrent aneurysms after coil embolization.

MATERIALS AND METHODS

Eight aneurysms in 8 patients treated with detachable coils had confirmed recurrent aneurysms: 3 giant, 1 large, 1 dissecting, and 3 small wide-necked. The recurrent aneurysms involved C3 in 1 patient, C4 in 1, C7 in 5, and V4 in 1. A total of 11 covered stents were implanted into 8 target arteries. Follow-up angiography was performed 1-16 months after the procedure. Clinical follow-up data were collected and retrospectively analyzed, grading as fully recovered, improved, unchanged, or aggravated.

RESULTS

Willis covered stent placement succeeded technically in all of the aneurysms. No technique-related adverse event occurred. Total occlusion was achieved immediately in 6 aneurysms, and a small endoleak was observed in 2 aneurysms. No mortality or morbidity occurred during or after the procedures, including during the follow-up period. Follow-up angiograms revealed that all 8 of the recurrent aneurysms were completely isolated, and 8 parent vessels kept patency, except 1 with mild stenosis. Clinical neurologic symptoms fully resolved in 5 patients, improved in 1, and were unchanged in 2 at the end of the follow-up period.

CONCLUSIONS

In this small study with a middle-term follow-up, the Willis covered stent was used safely and effectively to occlude recurred aneurysms after coiling. Longer-term follow-up and additional clinical experience are needed to fully determine the safety and efficacy of the device.

A new covered stent designed for intracranial vasculature: application in the management of pseudoaneurysms of the cranial internal carotid artery

BACKGROUND AND PURPOSE

The management of intracranial pseudoaneurysms is controversial. The purpose of this study was to provide a preliminary evaluation of the clinical efficacy of a Willis covered stent specially designed for the intracranial vasculature in the management of a pseudoaneurysm of the cranial internal carotid artery (CICA).

MATERIALS AND METHODS

Eight patients with pseudoaneurysms of the CICA were treated with use of the Willis covered stent. The flexibility of the entire stent system was gauged from the resistance met when reaching the target lesion and was categorized as no resistance, no apparent resistance, or resistance that could be overcome. The apposition of the Willis stent after deployment was scored as excellent with no endoleak, good with a small endoleak, or bad with an apparent endoleak. Follow-up angiography was performed 3 to 12 months after placement of the stent, and angiographic assessments were categorized as endoleak, stenosis of the covered segment of vessel, or occlusion of parent arteries. Follow-up clinical evaluations were also performed, and outcomes were graded as full recovery, improvement, unchanged, and aggravation.

RESULTS

Endovascular treatment was technically successful in all aneurysms without procedural-related complications, and all of the stents were easily navigated to the targeted lesions in the CICA. Complete resolution of the pseudoaneurysm was observed in 6 patients immediately after the procedure, and a minimal endoleak into the aneurysm persisted in 2 patients. No morbidity or mortality and no technical adverse event occurred. A follow-up angiogram confirmed complete reconstruction of the internal carotid artery, with no recurrent aneurysmal filling and no occurrence of stenosis in the area of the stent. By the final follow-up visit, 4 patients had fully recovered, 3 had improved, and 1 patient's condition was unchanged.

CONCLUSION

On the basis of our preliminary experience, the Willis covered stent specially designed for the intracranial vasculature can manage a CICA pseudoaneurysm safely and effectively, but longer follow-up and expanded clinical trials are needed.

Inter- and intra-observer variation of the Schatzker and AO/OTA classifications of tibial plateau fractures and a proposal of a new classification system

INTRODUCTION

The aim of this study was to evaluate the intra- and inter-observer variation of the Schatzker and AO/OTA classifications in assessing tibial plateau fractures, using plain radiographs.

PATIENTS AND METHODS

Fifty tibial plateau fractures were classified independently by six observers as per the Schatzker and AO/OTA classifications, using antero-posterior and lateral plain radiographs. Assessment was done on two occasions, 8 weeks apart.

RESULTS

We found that both the Schatzker and AO/OTA classifications have a high intra-observer (kappa = 0.57 and 0.53, respectively), and inter-observer (kappa = 0.41 and 0.43, respectively) variation. Classification of tibial plateau fractures into unicondylar versus bicondylar and pure splits versus articular depression +/- split conferred improved inter- and intra-observer variation.

CONCLUSIONS

The high inter-observer variation found for the Schatzker and AO/OTA classifications must be taken into consideration when these are used as a guidance of treatment and when used in evaluating patients' outcome. Simply classifying tibial plateau fractures into unicondylar versus bicondylar and pure splits versus articular depression +/- split may be more reliable.

Long germanium nanowires prepared by electrochemical etching

Germanium (Ge) nanowires have been produced by electrochemical etching of single-crystalline n-type Ge [100] in a HCl-containing aqueous electrolyte. Macropores could be etched at various etching currents after an optimized procedure for homogeneous pore nucleation was used. Because of the narrow band gap of Ge (0.66 eV), the leakage current through pore walls is much higher than that, for example, in Si, leading to a constant dissolution of the pore walls. At sufficiently high current densities, it is then possible to form nanowires with diameters determined by the width of the space charge region, ranging from roughly 50 to 500 nm, and a length of several hundred micrometers. The role of the space charge region for stabilizing pore formation and in the formation of nanowires will be discussed.

Angiographic follow-up of cerebral aneurysms treated with Guglielmi detachable coils: an analysis of 162 cases with 173 aneurysms

BACKGROUND AND PURPOSE

The endovascular approach, with the use of Guglielmi detachable coils (GDC), has been increasingly used to treat ruptured and unruptured cerebral aneurysms in recent years. Our objective was to assess the mid- to long-term radiologic outcome of cerebral aneurysms treated with GDC embolization.

METHODS

One hundred and sixty-two patients with a total of 173 aneurysms embolized with GDCs underwent angiographic follow-up 1 to 54 months after the procedure and were reviewed retrospectively. Each angiogram was reviewed by 2 neuroradiologists and 1 neurosurgeon, each of whom made a comparison between the initial and follow-up angiograms. Morphologic outcomes were scored as follows: unchanged, progressive thrombosis, and reopening or regrowth.

RESULTS

Of the 173 aneurysms with GDC embolization, 142 had total or nearly total occlusion, 23 subtotal occlusion, and 8 partial occlusion on the initial angiograms. The incidence of reopening was 17.1% (13/76) in less than 3 months and 6.2% (6/97) between 3 and 6 months after the procedure. Four aneurysms (2.3%) were found to be recurrent in the second follow-up angiography within 1 year after the procedure. The 1-year cumulative recurrent rate was 13.3%. Among 56 aneurysms with a third follow-up angiography in the period of 12 to 54 months after the procedure, 4 (7.1%) displayed a slight enlargement; the long-term cumulative recurrent rate was 20.4%.

CONCLUSION

The direct and primary causes for aneurysmal recurrence are incomplete and loose packing. The first angiographic follow-up is recommended to be performed at 3 months or earlier for incompletely occluded aneurysms and at 6 months for totally or nearly totally occluded aneurysms. In case of total or nearly total occlusion that remains stable at follow-up, the interval for monitoring should be prolonged appropriately. Retreatment with balloon- or stent-assisted coil embolization is recommended for reopened aneurysms.

Quantitative trait loci controlling vernalisation requirement, heading time and number of panicles in meadow fescue (Festuca pratensis Huds.)

The "BF14/16xHF2/7" mapping population of meadow fescue (Festuca pratensis Huds.) was characterised for number of panicles produced by non-vernalised plants in the field, vernalisation requirement (number of weeks at 6 degrees C and 8 h photoperiod), as well as days to heading, number of panicles and proportion of shoots heading after a 12 weeks vernalisation treatment. Quantitative trait loci (QTLs) were identified and compared to QTLs and genes related to the induction of flowering in cereals and grasses. A region on chromosome 1F affected days to heading and the proportion of shoots heading. Chromosome 4F appeared to have several genes with a strong effect on vernalisation requirement. The strongest effects were located in the proximal end of 4F and may correspond to the earliness per se (eps) QTL eps6L.2 in barley and a heading time QTL in perennial ryegrass. A part of the meadow fescue orthologue of VRN1 was sequenced and mapped to another region of 4F that also had a strong effect on vernalisation requirement. The proximal end of chromosome 5F had QTLs for days to heading and proportion of heading shoots. Syntenic regions in wheat and barley contain eps-loci. A QTL for number of panicles in the field and a QTL for proportion of heading shoots were present on chromosome 6. A region on 7F affected the variation in number of panicles among plants without a vernalisation requirement, and is syntenic to regions in perennial ryegrass, barley and rice containing orthologues of Arabidopsis thaliana CO.

The effect of isoforms of the cell polarity protein, human ASIP, on the cell cycle and Fas/FasL-mediated apoptosis in human hepatoma cells

Human ASIP (hASIP) is expressed as numerous alternative splicing isoforms and there is an atypical protein kinease C (aPKC) phosphorylation site in exon 17b of the encoded sequence. We have identified an important role for exon 17b in cancer cells. Our results showed that hASIP-sa and sb had different effects on cell growth and Fas/FasL-mediated apoptosis in BEL-7404 human hepatoma cells. Human ASIP-sa modified the S phase of the cell cycle and might stimulate cell proliferation. Growth inhibition by hASIP-a antisense oligonucleotide-confirmed the positive action of hASIP-sa. Compared with hASIP-sa, hASIP-sb accelerated Fas/FasL-induced apoptosis, examined by sub-G1 accumulation, chromatin condensation, nuclear fragmentation, PARP cleavage, caspase-8 degradation and mitochondria- regulated cell death. Treatment with aPKC inhibitor could enhance Fas/FasL-mediated apoptosis in hASIP-sa-overexpressing cells, suggesting that hASIP-sa and its interaction with aPKC might contribute to the malignant growth and the blocking of Fas/FasL-mediated apoptosis, while hASIP-sb might function as an antagonist of hASIP-sa.

Comparison of the survival of human biopsied embryos after cryopreservation with four different methods using non-transferable embryos

BACKGROUND

The standard embryo cryopreservation method is still less than optimal for biopsied embryos. The aim of this study was to compare the survival of biopsied embryos cryopreserved with four different methods using non-transferable embryos.

METHODS

Abnormal embryos from one or three pronuclei and spare embryos of grade 3 and 4 were used for this study. Non-biopsied embryos were cryopreserved using the standard method as control. Biopsied embryos were cryopreserved using four methods as follows: standard method, modified freezing method, modified thawing method and vitrification. Blastomere survival and blastulation of frozen-thawed embryos were compared between the different methods.

RESULTS

The proportion of embryos with > or = 50% blastomere survival and total blastomere survival rate of biopsied embryos were significantly higher with vitrification than the other three methods. Both the modified freezing and modified thawing methods had significantly higher embryo survival and total blastomere survival rates than standard methods. However, there was no significant difference in blastulation of surviving embryos in all the five groups.

CONCLUSIONS

Non-transferable embryos derived from clinical IVF/ICSI are useful for evaluation of the optimal freezing procedures for biopsied embryos. Vitrification increases the survival rate of human biopsied embryos above standard and modified cryopreservation methods.