Treatment of a cochlear implant biofilm infection: a potential role for alternative antimicrobial agents

OBJECTIVE:
This study aimed to investigate antimicrobial treatment of an infected cochlear implant, undertaken in an attempt to salvage the infected device.

METHODS:
We used the broth microdilution method to assess the susceptibility of meticillin-sensitive Staphylococcus aureus isolate, cultured from an infected cochlear implant, to common antimicrobial agents as well as to novel agents such as tea tree oil. To better simulate in vivo conditions, where bacteria grow as microcolonies encased in glycocalyx, the bactericidal activity of selected antimicrobial agents against the isolate growing in biofilm were also compared.

RESULTS:
When grown planktonically, the S aureus isolate was susceptible to 17 of the 18 antimicrobials tested. However, when grown in biofilm, it was resistant to all conventional antimicrobials. In contrast, 5 per cent tea tree oil completely eradicated the biofilm following exposure for 1 hour.

CONCLUSION:
Treatment of infected cochlear implants with novel agents such as tea tree oil could significantly improve salvage outcome.

Skin-reducing mastectomy and one-stage implant reconstruction with a myodermal flap: A safe and effective technique in risk-reducing and therapeutic mastectomy

Introduction: Immediate reconstruction following mastectomy for breast cancer has been shown to be oncologically safe and associated with improved psychosocial outcomes for patients. Bostwick described a technique for one-stage implant based reconstruction, combining skin-sparing mastectomy with concurrent reduction of the skin envelope. This report reviews the experience of a single centre using skin-reducing mastectomy and one-stage implant reconstruction in both early stage breast cancer and risk-reducing mastectomy, with specific reference to frequency of complications, implant loss and oncological outcomes.

Methods and results: A retrospective review was undertaken to identify women who had undergone skin-reducing mastectomy and one-stage implant reconstruction using a de-epithelialised dermal flap, between October 2008 and October 2012. One hundred and four consecutive mastectomies, with reconstruction, were performed by two surgeons on 64 patients. No complications were seen in 43.8% of patients. At three months, four implants were lost (3.8% of breast reconstructions, 6.3% of patients), due to either peri-implant infection or mastectomy skin flap necrosis. One patient required unplanned return to theatre for evacuation of a haematoma. Minor mastectomy skin flap necrosis was seen in 10 breasts (9.6% of reconstructed breasts) and superficial wound infection in 8 breasts (7.7% of reconstructed breasts). All of these complications were managed conservatively and none required operative intervention. At a median follow up of 35 months (4-53 months) there had been one episode of ipsilateral axillary nodal recurrence.

Conclusion: One-stage implant reconstruction using a myo-dermal flap technique following skin-reducing mastectomy is safe and should be considered in selected patients. Most complications are minor and will resolve with conservative management. Major complications such as implant failure or immediate reoperation, were relatively uncommon (6.3% patients, 3.8% of reconstructed breasts). Early follow-up suggests that oncological outcomes are satisfactory, but longer follow-up is required to substantiate this. (C) 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Effect of shotpeening on sliding wear and tensile behavior of titanium implant alloys

Titanium has good biocompatibility and so its alloys are used as implant materials, but they suffer from having poor wear resistance. This research aims to improve the wear resistance and the tensile strength of titanium alloys potentially for implant applications. Titanium alloys Ti–6Al–4V and Ti–6Al–7Nb were subjected to shotpeening process to study the wear and tensile behavior. An improvement in the wear resistance has been achieved due to surface hardening of these alloys by the process of shotpeening. Surface microhardness of shotpeened Ti–6Al–4V and Ti–6Al–7Nb alloys has increased by 113 and 58 HV(0.5), respectively. After shotpeening, ultimate tensile strength of Ti–6Al–4V increased from 1000 MPa to 1150 MPa, higher than improvement obtained for heat treated titanium specimens. The results confirm that shotpeening pre-treatment improved tensile and sliding wear behavior of Ti–6Al–4V and Ti–6Al–7Nb alloys. In addition, shotpeening increased surface roughness.

Implant-retained overdentures did not have a significant improvement in dietary intake

DESIGN: Randomised controlled trial.

INTERVENTION: Patients aged 65 or above edentate for a minimum of five years, with sufficient bone for two implants in the anterior mandible, were recruited. Those with systemic disease that contraindicated implants or had a low mini-mental state evaluation score were excluded. Patients in both groups had a standard maxillary complete denture fabricated. Patients randomised to the treatment group received a two-implant mandibular overdenture while those in the control group received a standard mandibular complete denture. Three 24-hour dietary recalls were collected by telephone interviews at baseline and at 12 months.

RESULTS: 255 patients were randomised: 128 received a standard complete denture (CD) and 127 a two-implant mandibular overdenture (IOD). 127 patients were available at 12-month follow up, 114 in the CD group and 103 in the IOD group. No significant between-group differences were found.

CONCLUSIONS: Although there is much evidence supporting the adoption of two-implant mandibular overdenture (IOD) treatment as the standard of care for edentate patients, this evidence does not include an improvement in dietary intake at one year for medically healthy independent edentate elders when given no specific dietary counselling.

Accelerated rehabilitation of an edentulous patient with an implant retained dental prosthesis: a case report

This case report details the successful rehabilitation of an edentulous patient using a complete upper prosthesis and a lower implant retained overdenture. The provision of care was split between a specialist centre and a primary care setting. This approach reduced inconvenience to the patient. Modern surgical and prosthodontic techniques also reduced the total delivery time. After initial consultation a new set of complete dentures was prescribed with changes in design to the originals. The patient was also planned for placement of two mandibular implants to stabilise and retain the mandibular denture. The first line of treatment involved provision of a new set of dentures constructed by the patient's general dental practitioner. Dental implants were then placed in a specialist centre and the patient returned to the dental practice for attachment of the lower denture to the dental implants. The benefits and success of mandibular implant retained dentures are well documented. With delivery of the overdenture, the patient reported increased satisfaction with his prostheses which allowed him to eat a greater range of foods and enabled him to feel confident when speaking and socialising.

In Helicobacter pylori auto-inducer-2, but not LuxS/MccAB catalysed reverse transsulphuration, regulates motility through modulation of flagellar gene transcription

BACKGROUND: LuxS may function as a metabolic enzyme or as the synthase of a quorum sensing signalling molecule, auto-inducer-2 (AI-2); hence, the mechanism underlying phenotypic changes upon luxS inactivation is not always clear. In Helicobacter pylori, we have recently shown that, rather than functioning in recycling methionine as in most bacteria, LuxS (along with newly-characterised MccA and MccB), synthesises cysteine via reverse transsulphuration. In this study, we investigated whether and how LuxS controls motility of H. pylori, specifically if it has its effects via luxS-required cysteine metabolism or via AI-2 synthesis only.

RESULTS: We report that disruption of luxS renders H. pylori non-motile in soft agar and by microscopy, whereas disruption of mccAHp or mccBHp (other genes in the cysteine provision pathway) does not, implying that the lost phenotype is not due to disrupted cysteine provision. The motility defect of the DeltaluxSHp mutant was complemented genetically by luxSHp and also by addition of in vitro synthesised AI-2 or 4, 5-dihydroxy-2, 3-pentanedione (DPD, the precursor of AI-2). In contrast, exogenously added cysteine could not restore motility to the DeltaluxSHp mutant, confirming that AI-2 synthesis, but not the metabolic effect of LuxS was important. Microscopy showed reduced number and length of flagella in the DeltaluxSHp mutant. Immunoblotting identified decreased levels of FlaA and FlgE but not FlaB in the DeltaluxSHp mutant, and RT-PCR showed that the expression of flaA, flgE, motA, motB, flhA and fliI but not flaB was reduced. Addition of DPD but not cysteine to the DeltaluxSHp mutant restored flagellar gene transcription, and the number and length of flagella.

CONCLUSIONS: Our data show that as well as being a metabolic enzyme, H. pylori LuxS has an alternative role in regulation of motility by modulating flagellar transcripts and flagellar biosynthesis through production of the signalling molecule AI-2.

Laser driven MeV proton beam focussing by auto-charged electrostatic lens configuration

Significant reduction of inherent large divergence of the laser driven MeV proton beams is achieved by strong (of the order of 10^9 V/m ) electrostatic focussing field generated in the confined region of a suitably shaped structure attached to the proton generating foil. The scheme exploits the positively charging of the target following an intense laser interaction. Reduction in the proton beam divergence, and commensurate increase in proton flux is observed while preserving the beam laminarity. The underlying mechanism has been established by the help of particle tracing simulations. Dynamic focussing power of the lens, mainly due to the target discharging, can also be exploited in order to bring up the desired chromaticity of the lens for the proton beams of broad energy range.

Escala de auto-cuidado em doentes com IC

A IC constitui-se como um grande problema de saúde associado a uma elevada morbilidade e mortalidade do doente, e a prevalência e incidência continuam a aumentar, devido sobretudo à isquemia aguda ou crónica, à maior resistência vascular derivada da hipertensão, ou ao desenvolvimento de taquiarritmias, como a fibrilação auricular. Trata-se de uma alteração de saúde grave que necessita de abordagens terapêuticas farmacológicas e não farmacológicas. No que respeita ao tratamento não farmacológico o enfermeiro tem uma intervenção determinante, que os enunciados descritivos da Ordem dos Enfermeiros descrevem como a promoção e monitorização do autocuidado do doente. O autocuidado pode ser definido por um conjunto de ações destinadas a manter a estabilidade física e a evitar comportamentos conducentes ao agravamento da situação e à deteção o mais precoce possível de sintomas de descompensação (European Society of Cardiology, 2008). Neste sentido considerámos pertinente validar a SCHFI V 6.2, Escala de avaliação do autocuidado do doente com Insuficiência Cardíaca, na população Portuguesa. A amostra do estudo é composta por 90 participantes de dois hospitais que tem consulta de enfermagem à pessoa com insuficiência cardíaca. A idade média dos participantes foi de 69,0 anos com desvio padrão de 10,5 anos, sendo 63 do sexo masculino e 26 do sexo feminino. No que respeita aos valores da escala para a população Portuguesa, estes apresentam nas três subescalas valores maioritariamente superiores a 50%, com alguma similitude aos valores apresentados na escala original. Consideramos que a Escala de Auto-Cuidado para A Pessoa Com Insuficiência Cardíaca é uma importante ferramenta de trabalho. Pois permite fazer o levantamento de informação pertinente que ajuda a centrar as intervenções e a promover as intervenções mais adequadas no que respeita à promoção e monitorização do autocuidado do doente com insuficiência cardíaca.