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1.
J Small Anim Pract ; 62(9): 795-804, 2021 09.
Article in English | MEDLINE | ID: mdl-34041760

ABSTRACT

OBJECTIVES: The aim of this case series was to report arthroscopic findings and to evaluate clinical outcomes of dogs treated with an inverted V-shaped extracapsular stabilisation technique without additional external coaptation for medial shoulder instability. MATERIAL AND METHODS: Medical records of dogs with medial shoulder instability that underwent arthroscopy and an inverted V-shaped extracapsular stabilisation technique were retrospectively reviewed. Extracapsular stabilisation was performed in all dogs using screws and spiked washers as anchor points for the coated polyester prosthetic ligament. No additional external coaptation was used in any dog. A minimum 18-month follow-up period was required for study inclusion. Complications and long-term outcomes were recorded. RESULTS: The subscapularis tendon and medial glenohumeral ligament were the structures most commonly affected. All dogs had pathological cartilage fibrillations. Implants were successfully placed in all dogs. Implant loosening was recorded in two out of six dogs on recheck but no revision surgery was performed. Function at the time of last clinical follow-up (median, 28 months, range 18 to 33 months) was full in four out of six and acceptable in two out of six dogs. CLINICAL SIGNIFICANCE: Surgical treatment of medial shoulder instability using the novel inverted V-shaped extracapsular stabilisation technique was successful. Potential complications such as implant loosening may occur. Despite the limited number of cases, the present study suggests that additional postoperative external coaptation may not be necessary for successful management of dogs with medial shoulder instability.


Subject(s)
Dog Diseases , Joint Instability , Shoulder Joint , Animals , Arthroscopy/veterinary , Dog Diseases/surgery , Dogs , Joint Instability/surgery , Joint Instability/veterinary , Retrospective Studies , Shoulder , Shoulder Joint/surgery
2.
Opt Express ; 27(24): 35750-35760, 2019 Nov 25.
Article in English | MEDLINE | ID: mdl-31878742

ABSTRACT

The T-matrix framework offers accurate and efficient modelling of electromagnetic scattering by nonspherical particles in a wide variety of applications ranging from nano-optics to atmospheric science. Its analytical setting, in contrast to purely numerical methods, also provides a fertile ground for further theoretical developments. Perhaps the main purported limitation of the method, when extended to systems of multiple particles, is the often-stated requirement that the smallest circumscribed spheres of neighbouring scatterers not overlap. We consider here such a scenario with two adjacent spheroids whose aspect ratio we vary to control the overlap of the smallest circumscribed spheres, and compute far-field cross-sections and near-field intensities using the superposition T-matrix method. The results correctly converge far beyond the no-overlap condition, and although numerical instabilities appear for the most extreme cases of overlap, requiring high multipole orders, convergence can still be obtained by switching to quadruple precision. Local fields converge wherever the Rayleigh hypothesis is valid for each single scatterer and, remarkably, even in parts of the overlap region. Our results are validated against finite-element calculations, and the agreement demonstrates that the superposition T-matrix method is more robust and broadly applicable than generally assumed.

3.
Aust Vet J ; 94(12): 470-473, 2016 12.
Article in English | MEDLINE | ID: mdl-27804124

ABSTRACT

CASE REPORT: A 3-year-old male neutered Domestic Shorthair cat was evaluated for a skin mass of approximately 2 × 3 cm arising from the right dorsolateral aspect of the tail at the junction between the proximal and middle one-thirds of the tail length. Incisional biopsy sample was consistent with granulomatous inflammation. The granuloma was surgically excised with 5 mm margins of normal skin. The resulting defect was closed using an axial pattern flap based on a cutaneous branch of the dorsal perineal artery and augmented by a local subdermal plexus transposition flap. There was 100% survival of the flaps at postoperative days 7, 15 and 21. CLINICAL SIGNIFICANCE: We describe an axial pattern flap based on a cutaneous branch of the dorsal perineal artery in a cat. This flap offers surgeons a viable option for closing skin defects situated on the proximal one-third of the tail and a practical alternative to tail amputation.


Subject(s)
Cats/surgery , Granuloma/veterinary , Surgical Flaps/veterinary , Tail/surgery , Animals , Granuloma/surgery , Inflammation/surgery , Inflammation/veterinary , Male , Tail/blood supply , Treatment Outcome
4.
Br J Dermatol ; 174(5): 1051-60, 2016 May.
Article in English | MEDLINE | ID: mdl-26748551

ABSTRACT

BACKGROUND: Psychiatric disorders have been extensively documented in patients with systemic lupus erythematosus (SLE). However, the prevalence of psychiatric disorders in patients with skin-restricted lupus (SRL) remains unknown, although SRL is more common than SLE. OBJECTIVES: To assess current and lifetime prevalence of Axis I psychiatric disorders among outpatients with SRL and to examine the factors associated with psychiatric disorders among such patients. METHODS: A multicentre case-control study involving outpatients with SRL and controls matched for sex, age and education level. The Mini International Neuropsychiatric Interview was used for psychiatric evaluation. RESULTS: We evaluated 75 patients and 150 controls. Of these, 49% of patients vs. 13% of controls fulfilled the criteria for at least one current psychiatric disorder (P < 0·001). The following disorders were significantly more frequent among patients than controls: current and lifetime major depressive disorder (9% vs. 0%, P < 0·001 and 44% vs. 26%, P = 0·01), generalized anxiety disorder (23% vs. 3%, P < 0·001 and 35% vs. 19%, P = 0·03), panic disorder (7% vs. 0%, P = 0·004 and 21% vs. 3%, P < 0·001), current suicide risk (24% vs. 7%, P = 0·003), alcohol dependence (7% vs. 0%, P = 0·004) and lifetime agoraphobia (20% vs. 9%, P = 0·01). Lupus duration and lupus past treatment by thalidomide were significantly higher among patients with current psychiatric disorders. CONCLUSIONS: This study demonstrates a high prevalence of several psychiatric disorders (anxiety, depression, suicide risk, alcohol dependence) in patients with SRL.


Subject(s)
Lupus Erythematosus, Cutaneous/psychology , Mental Disorders/epidemiology , Adult , Case-Control Studies , Female , France/epidemiology , Humans , Lupus Erythematosus, Cutaneous/epidemiology , Male , Mental Disorders/therapy , Mental Health Services/statistics & numerical data , Middle Aged , Prevalence , Socioeconomic Factors , Suicide, Attempted/statistics & numerical data
5.
Chem Commun (Camb) ; 50(55): 7299-302, 2014 Jul 14.
Article in English | MEDLINE | ID: mdl-24871625

ABSTRACT

Silica-coated gold nanorods functionalized with grafted fluorescent and photochromic derivatives were synthesized and characterized. Spectroscopic investigations demonstrated that cross-coupled interactions between plasmonic, photochromic, and fluorescence properties play a major role in such nanosystems, depending on the thickness of the silica spacer, leading to multi-signal photoswitchability.


Subject(s)
Fluorescent Dyes/chemistry , Nanostructures , Microscopy, Electron, Scanning
6.
Aust Vet J ; 92(4): 128-31, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24673140

ABSTRACT

CASE REPORT: We describe an unusual complication of a routine arthroscopic procedure to treat fragmentation of the medial portion of the coronoid process in a 1-year-old Labrador Retriever. While the lesion was being curetted, the tip of the arthroscopic curette broke off. Attempts were made to remove it, but failed, and the broken fragment migrated out of the arthroscopic field. Conversion from arthroscopy to arthrotomy was unsuccessful. On intraoperative radiographs, the metallic fragment was detected in the radial fossa of the humeral condyle. A limited surgical approach to this area, guided by ultrasound, also proved ineffective. Finally, the broken curette tip was left in situ. The dog made an uneventful recovery and 6 months after surgery it showed no lameness except after rest and there was no evidence of migration of the metallic fragment on radiographs. CONCLUSIONS: On such occasions, we recommend: (1) stop both the inflow and outflow of fluids; (2) attempt arthroscopic retrieval with a magnetic retriever and large forceps; (3) use diagnostic imaging to localise the broken fragment if it migrates out of the arthroscopic field; and (4) leave in situ if it is no longer accessible to arthroscopic extraction. This is the first report of an instrument breakage during arthroscopy in a dog.


Subject(s)
Arthroscopy/veterinary , Dogs/surgery , Forelimb/surgery , Joints/surgery , Animals , Arthroscopy/adverse effects , Foreign Bodies/diagnostic imaging , Foreign Bodies/veterinary , Forelimb/diagnostic imaging , Male , Radiography , Surgical Instruments/veterinary
7.
J Phys Chem C Nanomater Interfaces ; 117(48): 25650-25658, 2013 Dec 05.
Article in English | MEDLINE | ID: mdl-24340104

ABSTRACT

In this article, we investigate the Surface-Enhanced Raman Scattering (SERS) efficiency of methylene blue (MB) molecules deposited on gold nanostripes which, due to their fabrication by electron beam lithography and thermal evaporation, present various degrees of crystallinity and nanoscale surface roughness (NSR). By comparing gold nanostructures with different degrees of roughness and crystallinity, we show that the NSR has a strong effect on the SERS intensity of MB probe molecules. In particular, the NSR features of the lithographic structures significantly enhance the Raman signal of MB molecules, even when the excitation wavelength lies far from the localized surface plasmon resonance (LSPR) of the stripes. These results are in very good agreement with numerical calculations of the SERS gain obtained using the discrete dipole approximation (DDA). The influence of NSR on the optical near-field response of lithographic structures thus appears crucial since they are widely used in the context of nano-optics or/and molecular sensing.

8.
J Small Anim Pract ; 52(5): 232-9, 2011 May.
Article in English | MEDLINE | ID: mdl-21539567

ABSTRACT

OBJECTIVES: The goal of this study was to compare the dimensions of the soft palate and cross-sectional area of the meatus nasopharyngeus in non-brachycephalic dogs and brachycephalic dogs with different degrees of severity of brachycephalic airway syndrome using computed tomography. METHODS: A total of 26 brachycephalic dogs that had at least one of four major symptoms of snoring, inspiratory effort, stress or exercise intolerance, and syncope were included in this prospective study. The dogs were grouped by the frequency of different clinical signs into absent/minimal brachycephalic airway syndrome and severe brachycephalic airway syndrome groups. Five non-brachycephalic dogs were studied as control animals. All dogs underwent pharyngeal area computed tomography. Seven measurements were made on the transverse and midsagittal reconstructions. All parameters were compared between controls, absent/minimal and severe brachycephalic airway syndrome groups. RESULTS: The dogs with severe brachycephalic airway syndrome had significantly thicker soft palates compared to absent/minimal brachycephalic airway syndrome (P<0·05) and control (P<0·05) dogs. There were no significant differences among groups with regard to the length of the soft palate or the cross-sectional area of the airway at the level of the meatus nasopharyngeus. CLINICAL RELEVANCE: These results support the thickening of the soft palate as a component of severe brachycephalic airway syndrome. Further studies are required to confirm the association between this anatomical characteristic and functional impairment.


Subject(s)
Craniosynostoses/veterinary , Dog Diseases/diagnostic imaging , Nasopharynx/diagnostic imaging , Palate, Soft/diagnostic imaging , Tomography, X-Ray Computed/veterinary , Airway Obstruction/diagnostic imaging , Airway Obstruction/veterinary , Animals , Case-Control Studies , Craniosynostoses/diagnostic imaging , Dogs , Female , Male , Nasopharynx/anatomy & histology , Palate, Soft/anatomy & histology , Severity of Illness Index , Tomography, X-Ray Computed/methods
9.
Chem Commun (Camb) ; 47(13): 3903-5, 2011 Apr 07.
Article in English | MEDLINE | ID: mdl-21336414

ABSTRACT

We have measured the polarization and incident angle dependence of the Surface-Enhanced Raman Scattering (SERS) signal of a nile blue monolayer adsorbed on a flat gold surface. Comparisons with predictions of electromagnetic (EM) theory indicate that the molecules are predominantly adsorbed flat on the surface. These results provide the most direct demonstration of the concept of surface selection rules in SERS, and further confirm the validity of the SERS-EM model beyond the |E|(4)-approximation.

10.
EMBO J ; 30(2): 395-407, 2011 Jan 19.
Article in English | MEDLINE | ID: mdl-21139567

ABSTRACT

Apoptosis has an important role during development to regulate cell number. In differentiated cells, however, activation of autophagy has a critical role by enabling cells to remain functional following stress. In this study, we show that the antiapoptotic BCL-2 homologue MCL-1 has a key role in controlling both processes in a developmentally regulated manner. Specifically, MCL-1 degradation is an early event not only following induction of apoptosis, but also under nutrient deprivation conditions where MCL-1 levels regulate activation of autophagy. Furthermore, deletion of MCL-1 in cortical neurons of transgenic mice activates a robust autophagic response. This autophagic response can, however, be converted to apoptosis by either reducing the levels of the autophagy regulator Beclin-1, or by a concomitant activation of BAX. Our results define a pathway whereby MCL-1 has a key role in determining cell fate, by coordinately regulating apoptosis and autophagy.


Subject(s)
Apoptosis/physiology , Autophagy/physiology , Neurons/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Analysis of Variance , Animals , Apoptosis Regulatory Proteins/metabolism , Beclin-1 , Fluorescent Antibody Technique , Humans , Immunoblotting , Immunohistochemistry , Membrane Proteins/metabolism , Mice , Mice, Knockout , Myeloid Cell Leukemia Sequence 1 Protein , Proto-Oncogene Proteins c-bcl-2/genetics , bcl-2-Associated X Protein/metabolism
11.
Aust Vet J ; 88(7): 268-71, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20579033

ABSTRACT

A cyst of the common bile duct (CBD) is reported in a 9-year-old cat that presented with a 1-week history of anorexia, weight loss and vomiting. Diagnosis was established by ultrasound examination and laparotomy, and was ultimately confirmed by histological analysis. Chronic cholangitis and an Escherichia coli species were detected concurrently according to the histopathological findings and bile culture, respectively. The case was managed by suturing the borders of the ostium of the cyst over a stent, using a temporary cholecystostomy tube and antibiotic therapy. At 7 months following the surgery, the cat was in excellent physical condition with no clinical evidence of recurrence of cholangitis or of the cyst after ultrasonographic evaluation. According to the human literature, cysts of the CBD require treatment because of their common association with cholangitis, pancreatitis, and cystic rupture. We were unable to confirm a link between the cyst and cholangitis in this case. It is possible that detection of this anomaly was an incidental finding unrelated to bacterbilia. Histological examination of cyst tissue is mandatory for a definitive diagnosis and to differentiate it from neoplasia. This is the first description of a cyst of the CBD in the cat.


Subject(s)
Cat Diseases/diagnosis , Cat Diseases/surgery , Cholangitis/veterinary , Choledochal Cyst/veterinary , Animals , Anti-Bacterial Agents/therapeutic use , Cats , Cholangitis/diagnosis , Cholangitis/drug therapy , Cholangitis/surgery , Choledochal Cyst/diagnosis , Choledochal Cyst/surgery , Escherichia coli/isolation & purification , Escherichia coli Infections/diagnosis , Escherichia coli Infections/drug therapy , Escherichia coli Infections/surgery , Escherichia coli Infections/veterinary , Female , Treatment Outcome
12.
Vet Comp Orthop Traumatol ; 22(6): 460-6, 2009.
Article in English | MEDLINE | ID: mdl-19876529

ABSTRACT

The aim of the study was to evaluate the bone healing properties of an osteopromotive platelet rich plasma (PRP) gel in combination with osteoconductive calcium phosphate (CaP) ceramic granules in a long-bone critical size defect in dogs. A standardised 2 cm long ulnar ostectomy was performed bilaterally in four dogs to compare new-bone formation by CaP matrix with and without association with PRP. Radiographic and histological evaluations were performed blindly. Radiographic evaluation was performed at three, six, nine, 12 and 16 weeks postoperatively. Quantitative measurements of new-bone formation were compared using statistical analysis. At explantation 16 weeks after surgery, no significant ossification was present, neither with CaP granules alone nor in association with PRP gel, and there was no difference of radiodensity between the groups. Qualitative histological evaluation demonstrated for both types of implants the presence of non-mineralised fibrous connective tissue around the CaP granules. New-bone formation was only present to a very small extent within the macropores of the CaP granules at the distal bone-implant interface. In our model which exhibited very limited osteoconduction, neither the CaP granules alone nor in association with PRP were sufficient to stimulate bone healing. In this canine model employing a critical size ulnar gap, the combination of CaP granules and PRP did not effectively promote bone regeneration.


Subject(s)
Absorbable Implants/veterinary , Blood Platelets/physiology , Bone Substitutes/therapeutic use , Calcium Phosphates/chemistry , Animals , Biomechanical Phenomena , Bone Regeneration , Dogs , Female , Fracture Healing , Implants, Experimental , Ulna/pathology
13.
BMJ ; 339: b3264, 2009 Sep 03.
Article in English | MEDLINE | ID: mdl-19729415

ABSTRACT

OBJECTIVE: To determine whether observable changes in waiting times occurred for certain key elective procedures between 1997 and 2007 in the English National Health Service and to analyse the distribution of those changes between socioeconomic groups as an indicator of equity. DESIGN: Retrospective study of population-wide, patient level data using ordinary least squares regression to investigate the statistical relation between waiting times and patients' socioeconomic status. SETTING: English NHS from 1997 to 2007. PARTICIPANTS: 427,277 patients who had elective knee replacement, 406,253 who had elective hip replacement, and 2,568,318 who had elective cataract repair. MAIN OUTCOME MEASURES: Days waited from referral for surgery to surgery itself; socioeconomic status based on Carstairs index of deprivation. RESULTS: Mean and median waiting times rose initially and then fell steadily over time. By 2007 variation in waiting times across the population tended to be lower. In 1997 waiting times and deprivation tended to be positively related. By 2007 the relation between deprivation and waiting time was less pronounced, and, in some cases, patients from the most deprived fifth were waiting less time than patients from the most advantaged fifth. CONCLUSIONS: Between 1997 and 2007 waiting times for patients having elective hip replacement, knee replacement, and cataract repair in England went down and the variation in waiting times for those procedures across socioeconomic groups was reduced. Many people feared that the government's NHS reforms would lead to inequity, but inequity with respect to waiting times did not increase; if anything, it decreased. Although proving that the later stages of those reforms, which included patient choice, provider competition, and expanded capacity, was a catalyst for improvements in equity is impossible, the data show that these reforms, at a minimum, did not harm equity.


Subject(s)
Health Care Reform/organization & administration , State Medicine/organization & administration , Waiting Lists , Arthroplasty, Replacement, Hip/statistics & numerical data , Arthroplasty, Replacement, Knee/statistics & numerical data , Cataract Extraction/statistics & numerical data , England , Health Care Reform/trends , Health Services Accessibility/organization & administration , Health Services Accessibility/trends , Humans , Regression Analysis , Retrospective Studies , Socioeconomic Factors , State Medicine/trends , Time Factors
14.
Pathol Biol (Paris) ; 57(1): 56-60, 2009 Feb.
Article in French | MEDLINE | ID: mdl-18845404

ABSTRACT

INTRODUCTION: Outbreaks of vancomycin-resistant enterococci have been increasingly reported in France over the last three years. We report here, the emergence of a vancomycin-dependent enterococci isolate following glycopeptide therapy. PATIENTS AND METHODS: An Enterococcus faecium isolate that required vancomycin for growth was cultured from the stools of a liver transplant recipient who was colonised with vancomycin-resistant enterococci and who received vancomycin treatment for methicillin-resistant Staphylococcus aureus infection. The resistant isolate and the dependent isolate were typed by pulsed-field gel electrophoresis. The sequence of the ddl gene coding for the D-Ala: D-Ala ligase was analysed. RESULTS: The dependent isolate was primary cultured onto a vancomycin-containing screening medium and could not be subcultured in the absence of vancomycin. Both the resistant and dependent isolates harboured the vanA gene and they had the same DNA restriction pattern after pulsed-field gel electrophoresis. Dependence on vancomycin was associated with a 1-bp deletion in the D-Ala: D-Ala ligase gene leading to an early stop odon. CONCLUSION: Cultures onto vancomycin-containing media are warranted for clinical specimens from patients, who are known to carry vancomycin-resistant enterococci and receive vancomycin therapy.


Subject(s)
Enterococcus faecium/drug effects , Gram-Positive Bacterial Infections/microbiology , Vancomycin/pharmacology , Bacterial Proteins/genetics , Bacteriuria/drug therapy , Bacteriuria/microbiology , Carbon-Oxygen Ligases/genetics , Cecal Diseases/complications , Ceftriaxone/therapeutic use , Citrobacter freundii/drug effects , Citrobacter freundii/isolation & purification , Codon, Nonsense , Drug Resistance, Multiple, Bacterial , Drug Therapy, Combination , Electrophoresis, Gel, Pulsed-Field , Enterobacteriaceae Infections/etiology , Enterobacteriaceae Infections/microbiology , Enterococcus faecium/genetics , Enterococcus faecium/growth & development , Enterococcus faecium/isolation & purification , Female , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/epidemiology , Humans , Intestinal Perforation/complications , Liver Transplantation , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Middle Aged , Norfloxacin/therapeutic use , Peritonitis/etiology , Peritonitis/microbiology , Postoperative Complications/drug therapy , Postoperative Complications/microbiology , Staphylococcal Infections/drug therapy , Teicoplanin/pharmacology , Vancomycin/therapeutic use , Vancomycin Resistance
15.
Clin Microbiol Infect ; 14(11): 1034-40, 2008 Nov.
Article in English | MEDLINE | ID: mdl-19040475

ABSTRACT

Spontaneous bacterial peritonitis (SBP) is a severe complication in patients with cirrhosis and ascites. It is predominantly caused by Escherichia coli. The phylogenetic group and virulence genotype of E. coli isolates causing SBP were investigated, and the association of these characteristics with host factors and prognosis was examined. Seventy-six episodes of E. coli SBP that occurred over a 9-year period were studied. The phylogenetic group of the isolates and the presence of 36 virulence factor genes were investigated. The influence of bacterial and host factors on in-hospital mortality was assessed by multiple logistic regression. Phylogenetic groups A, B1, B2 and D were found in 26%, 4%, 46% and 24% of the isolates, respectively. Virulence factor genes were more frequent in B2 isolates than in non-B2 isolates (mean virulence score 15.4 vs. 7.3, p <10(-4)). Ciprofloxacin resistance was significantly associated with non-B2 groups and a low virulence score. Host factors independently associated with a shift from B2 to non-B2 isolates were norfloxacin prophylaxis (OR 13.01, p 0.0213) and prothrombin ratio (OR 1.04 for a 10% decrease, p 0.0211). The model for end-stage liver disease (MELD) score (OR 1.83, p 0.0007) and hospital-acquired SBP (OR 4.13, p 0.0247) were independent predictors of in-hospital mortality. In contrast, outcome was not influenced by the phylogenetic group or the virulence profile. These findings indicate that the characteristics of E. coli isolates causing SBP vary with the severity of liver disease and with fluoroquinolone prophylaxis. Host factors are more important than bacterial factors in predicting in-hospital mortality.


Subject(s)
Escherichia coli Infections/microbiology , Escherichia coli Proteins/genetics , Escherichia coli/genetics , Escherichia coli/isolation & purification , Peritonitis/microbiology , Virulence Factors/genetics , Adult , Aged , Ascites/complications , DNA, Bacterial/genetics , Drug Resistance, Bacterial , Escherichia coli/classification , Escherichia coli/pathogenicity , Escherichia coli Infections/mortality , Female , Fibrosis/complications , Genotype , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Peritonitis/mortality , Prognosis , Virulence
17.
J Neurosci ; 28(24): 6068-78, 2008 Jun 11.
Article in English | MEDLINE | ID: mdl-18550749

ABSTRACT

Despite the importance of Mcl-1, an anti-apoptotic Bcl-2 family member, in the regulation of apoptosis, little is known regarding its role in nervous system development and injury-induced neuronal cell death. Because germline deletion of Mcl-1 results in peri-implantation lethality, we address the function of Mcl-1 in the nervous system using two different conditional Mcl-1 mouse mutants in the developing nervous system. Here, we show for the first time that Mcl-1 is required for neuronal development. Neural precursors within the ventricular zone and newly committed neurons in the cortical plate express high levels of Mcl-1 throughout cortical neurogenesis. Loss of Mcl-1 in neuronal progenitors results in widespread apoptosis. Double labeling with active caspase 3 and Tuj1 reveals that newly committed Mcl1 deficient neurons undergo apoptosis as they commence migration away from the ventricular zone. Examination of neural progenitor differentiation in vitro demonstrated that cell death in the absence of Mcl1 is cell autonomous. Although conditional deletion of Mcl-1 in cultured neurons does not trigger apoptosis, loss of Mcl-1 sensitizes neurons to an acute DNA damaging insult. Indeed, the rapid reduction of Mcl-1 mRNA and protein levels are early events after DNA damage in neurons, and maintaining high Mcl-1 levels can protect neurons against death. Together, our results are the first to demonstrate the requirement of Mcl-1, an anti-apoptotic Bcl-2 family protein, for cortical neurogenesis and the survival of neurons after DNA damage.


Subject(s)
Apoptosis/physiology , Central Nervous System/embryology , DNA Damage/physiology , Gene Expression Regulation, Developmental/physiology , Neurons/physiology , Proto-Oncogene Proteins c-bcl-2/physiology , Age Factors , Animals , Apoptosis/genetics , Caspase 3/metabolism , Cell Differentiation , Cell Movement/genetics , Cell Movement/physiology , Cell Proliferation , Cells, Cultured , Central Nervous System/cytology , DNA Damage/genetics , Embryo, Mammalian , Gene Expression Regulation, Developmental/genetics , Green Fluorescent Proteins/metabolism , Mice , Mice, Transgenic , Mutation/genetics , Myeloid Cell Leukemia Sequence 1 Protein , Nerve Tissue Proteins/metabolism , Proto-Oncogene Proteins c-bcl-2/genetics , Stem Cells/physiology , Transfection/methods , Tubulin/metabolism
18.
J Chem Phys ; 128(9): 094702, 2008 Mar 07.
Article in English | MEDLINE | ID: mdl-18331105

ABSTRACT

In this paper, we report on the observation of multipolar surface plasmon excitation in lithographically designed gold nanotriangles, investigated by means of far-field extinction microspectroscopy in the wavelength range of 400-1000 nm. Several bands are observed in the visible and near infrared regions when increasing the side length of the triangles. The assignment of these peaks to successive in-plane multipolar plasmon modes is supported by calculations using the discrete dipole approximation method. We show that the lowest three multipolar excitations are clearly resolved in the visible and near infrared range. These new spectral features could be very promising in nanooptics or for chemosensing and biosensing applications.

19.
J Microsc ; 229(Pt 3): 428-32, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18331490

ABSTRACT

We numerically study the influence of the shape of gold nanostructures on the spectral position of their localized surface plasmon resonance and on Surface Enhanced Raman Scattering efficiency. Calculations are performed using a Finite-Difference Time-Domain (FDTD) method, whose accuracy for dispersive media is enhanced through the use of a Drude-Lorentz model. The relevance of this method is then pointed out by comparing the calculations with experimental data for both the plasmon resonance and the Raman signal enhancement. The influence of a thin layer of water is also investigated.

20.
J Microsc ; 229(Pt 2): 189-96, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18304071

ABSTRACT

This article reports on the imaging of the surface plasmon fields of lithographically designed micrometre-sized gold structures. We investigate rings made of disk-shaped particles and individual crescent-shaped particles. These structures are imaged with two techniques, dark field imaging of elastically scattered light and imaging the surface-enhanced Raman scattering signal of methylene blue dye adsorbed onto the structures. Although elastically scattered light images result from the coherently summed contributions from all elementary scattering volumes, surface-enhanced Raman scattering images reflect the optical near-field intensity incoherently averaged over a surface area corresponding to the spatial resolution of the microscope objective. The combination of both imaging methods enables us to emphasize the role of plasmon coupling and antenna effect in the surface-enhanced Raman scattering enhancement.

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