ABSTRACT
Antigen-specific immunotherapy is an immunomodulatory strategy for autoimmune diseases, such as type 1 diabetes, in which patients are treated with autoantigens to promote immune tolerance, stop autoimmune ß-cell destruction and prevent permanent dependence on exogenous insulin. In this study, human proinsulin peptide C19-A3 (known for its positive safety profile) was conjugated to ultrasmall gold nanoparticles (GNPs), an attractive drug delivery platform due to the potential anti-inflammatory properties of gold. We hypothesised that microneedle intradermal delivery of C19-A3 GNP may improve peptide pharmacokinetics and induce tolerogenic immunomodulation and proceeded to evaluate its safety and feasibility in a first-in-human trial. Allowing for the limitation of the small number of participants, intradermal administration of C19-A3 GNP appears safe and well tolerated in participants with type 1 diabetes. The associated prolonged skin retention of C19-A3 GNP after intradermal administration offers a number of possibilities to enhance its tolerogenic potential, which should be explored in future studies.
ABSTRACT
We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.
ABSTRACT
A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.149 GeV. The asymmetry result is B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θ_{lab}â0) where they should be most reliable.
ABSTRACT
BACKGROUND: Osteoporosis is common, increasing as the population ages and has significant consequences including fracture. Effective treatments are available. AIM: To support proactive fracture risk assessment (FRAX) and optimizing treatment for high-risk patients in primary care. DESIGN: Clinical cohort. SETTING: November 2017 to November 2018, support was provided to 71 practices comprising 69 of 90 practices within two National Health Service Clinical Commissioning Groups areas. Total population 579 508 (207 263 aged over 50 years). PARTICIPANTS: FRAX (National Institute for Care and Clinical Excellence, NICE CG146) in (i) males aged 75 years and over, (ii) females aged 65 years and over, (iii) females aged under 65 years and males aged under 75 years with risk factors and (iv) under 50 years with major risk factors. RESULTS: A total of 158 946 met NICE CG146, 11 961 were coded with an osteoporosis diagnosis (7.5%), of those, 42% were prescribed treatment with a bone sparing agent (BSA). In total, 6942 were assessed to initiate BSA. Thirty percent of untreated osteoporosis diagnosis patients had never been prescribed BSA. Even when prescribed, 1700 people (35%) were for less than minimum recommended duration. Of the total 9784 patients within the FRAX recommended to treat threshold, 3197 (33%) were currently treated with BSA and 3684 (37%) had no history of ever receiving BSA. From untreated patients, expected incidence of 875 fractures over a 3-year period (approximately £3.4 million). Treatment would prevent 274 fractures (cost reduction: £1 274 045, with prescribing costs: saving £805 145 after 3 years of treatment). CONCLUSION: Underdiagnosis and suboptimal treatment of osteoporosis was identified. Results suggest that implementing NICE guidance and optimizing treatment options in practice is possible and could prevent significant fractures.
Subject(s)
Bone Density Conservation Agents/therapeutic use , Osteoporosis/complications , Osteoporotic Fractures/prevention & control , Primary Health Care , Aged , Aged, 80 and over , Bone Density , Female , Humans , Male , Middle Aged , Osteoporosis/drug therapy , Osteoporosis/epidemiology , Osteoporotic Fractures/epidemiology , Risk Assessment/methods , Risk Factors , State Medicine , United Kingdom/epidemiologyABSTRACT
Antigen specific immunotherapy aims to tolerise patients to specific autoantigens that are responsible for the pathology of an autoimmune disease. Immune tolerance is generated in conditions where the immune response is suppressed and thus gold nanoparticles (AuNPs) are an attractive drug delivery platform due to their anti-inflammatory effects and their potential to facilitate temporal and spatial delivery of a peptide autoantigen in conjunction with pro-tolerogenic elements. In this study we have covalently attached an autoantigen, currently under clinical evaluation for the treatment of type 1 diabetes (PIC19-A3 peptide), to AuNPs to create nanoscale (<5â¯nm), negatively charged (-40 to -60â¯mV) AuNP-peptide complexes for immunotherapy. We also employ a clinically approved microneedle delivery system, MicronJet600, to facilitate minimally-invasive intradermal delivery of the nanoparticle constructs to target skin-resident antigen presenting cells, which are known to be apposite target cells for immunotherapy. The AuNP-peptide complexes remain physically stable upon extrusion through microneedles and when delivered into ex vivo human skin they are able to diffuse rapidly and widely throughout the dermis (their site of deposition) and, perhaps more surprisingly, the overlying epidermal layer. Intracellular uptake was extensive, with Langerhans cells proving to be the most efficient cells at internalising the AuNP-peptide complex (94% of the local population within the treated region of skin). In vitro studies showed that uptake of the AuNP-peptide complexes by dendritic cells reduced the capacity of these cells to activate naïve T cells. This indicator of biological functionality encourages further development of the AuNP-peptide formulation, which is now being evaluated in clinical trials.
Subject(s)
Autoantigens/administration & dosage , Gold/administration & dosage , Immunotherapy , Metal Nanoparticles/administration & dosage , Peptides/administration & dosage , Skin/metabolism , Adult , Aged , Aged, 80 and over , Biological Transport , Cells, Cultured , Dendritic Cells/drug effects , Dendritic Cells/immunology , Female , Humans , Injections, Intradermal , Middle Aged , Skin/cytology , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
Infantile haemangiomas are the most common tumour of infancy. Whilst the majority are left untreated to involute spontaneously, residual skin changes commonly occur, particularly in superficial haemangiomas. The current first-line treatment for problematic lesions is oral propranolol; however due to the risk of systemic adverse effects, the use of off-label topical preparations has recently been investigated. Our systematic review was conducted in accordance with PRISMA guidelines. Four databases were searched to identify original articles evaluating the use of topical propranolol as the primary therapy for infantile haemangiomas. Twelve articles with a total of 597 patients and 632 haemangiomas were included. Three topical propranolol preparations were used, creams, ointments and gels and were all prepared by local pharmaceutical laboratories. The concentration of propranolol ranged from 0.5% to 5%. Treatment duration ranged from two weeks to 16.5 months. Overall, 90% of lesions improved following the initiation of topical propranolol. A good or excellent response, defined as a reduction in the size of at least 50%, was seen in 59% of lesions. Earlier initiation of treatment (less than 3 months of age) was associated with improved outcomes. No systemic adverse effects were reported. Minor local reactions were seen in 1.3% of patients. Topical propranolol is safer than oral propranolol, though may be less effective. Topical propranolol may be more suitable for patients with small, superficial haemangiomas at risk of cosmetic sequelae, where the cosmetic or symptomatic impact does not warrant oral propranolol treatment.
Subject(s)
Antineoplastic Agents/therapeutic use , Hemangioma/drug therapy , Propranolol/therapeutic use , Skin Neoplasms/drug therapy , Administration, Cutaneous , Antineoplastic Agents/administration & dosage , Gels , Humans , Ointments , Propranolol/administration & dosage , Skin CreamABSTRACT
BACKGROUND: Translation of cell therapies to the clinic is accompanied by numerous challenges, including controlled and targeted delivery of the cells to their site of action, without compromising cell viability and functionality. OBJECTIVES: To explore the use of hollow microneedle devices (to date only used for the delivery of drugs and vaccines into the skin and for the extraction of biological fluids) to deliver cells into skin in a minimally invasive, user-friendly and targeted fashion. METHODS: Melanocyte, keratinocyte and mixed epidermal cell suspensions were passed through various types of microneedles and subsequently delivered into the skin. RESULTS: Cell viability and functionality are maintained after injection through hollow microneedles with a bore size ≥ 75 µm. Healthy cells are delivered into the skin at clinically relevant depths. CONCLUSIONS: Hollow microneedles provide an innovative and minimally invasive method for delivering functional cells into the skin. Microneedle cell delivery represents a potential new treatment option for cell therapy approaches including skin repigmentation, wound repair, scar and burn remodelling, immune therapies and cancer vaccines.
Subject(s)
Cell- and Tissue-Based Therapy/instrumentation , Needles , Administration, Cutaneous , Cell Survival/physiology , Cell- and Tissue-Based Therapy/methods , Epidermal Cells/transplantation , Equipment Design , Humans , Injections, Subcutaneous , Keratinocytes/transplantation , Melanocytes/transplantation , Transplantation, Autologous , Wound Healing/physiologyABSTRACT
BACKGROUND: The management of epistaxis requires an understanding of haematological factors that may complicate its treatment. This systematic review includes six distinct reviews examining the evidence supporting epistaxis-specific management strategies relating to warfarin, direct oral anticoagulants, heparin, antiplatelet agents, tranexamic acid and transfusion. METHOD: A systematic review of the literature was performed using a standardised methodology and search strategy. RESULTS: Limited numbers of articles were identified in each systematic review, with level 1 evidence only regarding the use of tranexamic acid. No studies met the inclusion criteria within the heparin, direct oral anticoagulants or transfusion systematic reviews. Many studies were limited by small sample sizes and significant risk of bias. CONCLUSION: The management of major bleeding and transfusion practice is well documented in national guidance from multiple sources. The guidelines include advice on anticoagulants, antiplatelet agents and tranexamic acid. In the absence of more specific evidence, these guidelines should be applied in the management of epistaxis.
Subject(s)
Epistaxis/blood , Epistaxis/therapy , Adult , Anticoagulants/adverse effects , Anticoagulants/therapeutic use , Blood Transfusion , Epistaxis/chemically induced , Evidence-Based Medicine , Guideline Adherence , Heparin/adverse effects , Heparin/therapeutic use , Humans , International Normalized Ratio , Length of Stay , Platelet Aggregation Inhibitors/adverse effects , Platelet Aggregation Inhibitors/therapeutic use , Tranexamic Acid/adverse effects , Tranexamic Acid/therapeutic use , Treatment Outcome , Warfarin/adverse effects , Warfarin/therapeutic useABSTRACT
Microneedle devices have been proposed as a minimally invasive delivery system for the intradermal administration of nucleic acids, both plasmid DNA (pDNA) and siRNA, to treat localised disease or provide vaccination. Different microneedle types and application methods have been investigated in the laboratory, but limited and irreproducible levels of gene expression have proven to be significant challenges to pre-clinical to clinical progression. This study is the first to explore the potential of a hollow microneedle device for the delivery and subsequent expression of pDNA in human skin. The regulatory approved MicronJet600® (MicronJet hereafter) device was used to deliver reporter plasmids (pCMVß and pEGFP-N1) into viable excised human skin. Exogenous gene expression was subsequently detected at multiple locations that were distant from the injection site but within the confines of the bleb created by the intradermal bolus. The observed levels of gene expression in the tissue are at least comparable to that achieved by the most invasive microneedle application methods e.g. lateral application of a microneedle. Gene expression was predominantly located in the epidermis, although also evident in the papillary dermis. Optical coherence tomography permitted real time visualisation of the sub-surface skin architecture and, unlike a conventional intradermal injection, MicronJet administration of a 50µL bolus appears to create multiple superficial microdisruptions in the papillary dermis and epidermis. These were co-localised with expression of the pCMVß reporter plasmid. We have therefore shown, for the first time, that a hollow microneedle device can facilitate efficient and reproducible gene expression of exogenous naked pDNA in human skin using volumes that are considered to be standard for intradermal administration, and postulate a hydrodynamic effect as the mechanism of gene delivery.
Subject(s)
Gene Transfer Techniques , Needles , Skin/metabolism , Administration, Cutaneous , Cell Culture Techniques , Cell Line , Dermis/metabolism , Epidermis/metabolism , Gene Expression , Humans , Hydrodynamics , Injections, Intradermal , Microinjections , RNA, Small Interfering/metabolism , Skin Absorption , Tissue Distribution , Transfection/methodsABSTRACT
INTRODUCTION: Infectious conditions of the middle ear are a common and significant cause of morbidity and mortality worldwide. Systemic antibiotics are frequently used, but their effectiveness will depend on whether an adequate antibiotic concentration is achieved in the middle ear; this is especially important in biofilm infections such as otitis media with effusion (OME), where high antibiotic concentrations are typically required for effective treatment. OBJECTIVE: This review examines what antibiotic levels can be reached in the middle ear with oral administration, as a means of guiding rational antibiotic choice in the clinic and future research, and to determine whether levels high enough for biofilm eradication are reached. METHODS: A literature search of studies measuring levels of antibiotics in the plasma and in the middle ear after oral administration was conducted. These levels were compared to the minimum inhibitory concentrations (MIC) provided by the European Committee for Antimicrobial Susceptibility Testing (EUCAST) to determine if antibiotic doses were reaching sufficient levels to inhibit planktonic bacteria. The middle ear concentrations were then calculated as a multiple of the MIC to determine if the concentrations were reaching biofilm eradication concentrations (typically up to 1000×MIC). RESULTS: The highest antibiotic levels against Staphylococcus aureus reach 8.3×MIC, against Moraxella catarrhalis 33.2×MIC, against Haemophilus influenzae 31.2×MIC, and against Streptococcus pneumoniae 46.2×MIC. The macrolide antibiotics reach higher levels in the middle ear than in plasma. CONCLUSIONS: Orally administered antibiotics reach levels above the MIC in the middle ear. However, they do not reach levels that would be likely to eradicate biofilms.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/pharmacokinetics , Biofilms/drug effects , Ear, Middle/metabolism , Otitis Media with Effusion/drug therapy , Otitis Media with Effusion/microbiology , Administration, Oral , Haemophilus influenzae , Humans , Microbial Sensitivity Tests , Moraxella catarrhalis , Otitis Media with Effusion/blood , Plankton , Staphylococcus aureusABSTRACT
OBJECTIVE: To review new incidental findings detected on low-resolution CT attenuation correction (CTAC) images acquired during single-photon emission CT (SPECT-CT) myocardial perfusion imaging (MPI) and to determine whether the CTAC images had diagnostic value and warrant reporting. METHODS: A multicentre study was performed in four UK nuclear medicine departments. CTAC images acquired as part of MPI performed using SPECT were evaluated to identify incidental findings. New findings considered to be clinically significant were evaluated further. Positive predictive value (PPV) was determined at the time of definitive diagnosis. RESULTS: Of 1819 patients studied, 497 (27.3%) had a positive CTAC finding. 51 (2.8%) patients had findings that were clinically significant at the time of the CTAC report and had not been previously diagnosed. Only four (0.2%) of these were potentially detrimental to patient outcome. CONCLUSION: One centre had a PPV of 0%, and the study suggests that these CTAC images should not be reported. Two centres with more modern equipment had low PPVs of 0% and 6%, respectively, and further research is suggested prior to drawing a conclusion. The centre with best quality CT had a PPV of 67%, and the study suggests that CTAC images from this equipment should be reported. ADVANCES IN KNOWLEDGE: This study is unique compared with previous studies that have reported only the potential to identify incidental findings on low-resolution CT images. This study both identifies and evaluates new clinically significant incidental findings, and it demonstrates that the benefit of reporting the CTAC images depends on the type of equipment used.
Subject(s)
Image Processing, Computer-Assisted/methods , Incidental Findings , Multidetector Computed Tomography/methods , Myocardial Perfusion Imaging/methods , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Radiographic Image Enhancement , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed/methodsABSTRACT
BACKGROUND: O RhD-negative (ONeg) red cells can be used in an emergency for recipients of other blood groups. Matching supply and demand is currently a challenge; therefore, any service redesign, using more remote blood fridges, must consider ONeg red cell availability. OBJECTIVES: To identify whether the number of fridges stocking emergency ONeg units correlates with use and wastage. METHODS: The number and distribution of ONeg red cells was requested from the hospitals in South West England. For NHS Hospitals, comparison was made with ONeg National Health Service (NHS) organisation--NHS Blood and Transplant (NHSBT) issues (ONeg as a proportion of all red cells), wastage and the proportion of ONeg units given to ONeg patients (ONeg-to-ONeg use). Correlations were performed using Spearman's rank correlation coefficient. RESULTS: Of the 23 hospitals, 21 responded. Four hundred and forty three ONeg units were held across the region--56% as stock and the remaining as emergency units. ONeg issues increased with the number of fridges holding emergency units (ρ = 0.48, significance 0.046). No correlation was found between the number of fridges and ONeg wastage or ONeg-to-ONeg use. A longer unit shelf life on rotation back to stock was associated with lower wastage (ρ = -0.597, significance 0.009). CONCLUSIONS: Although there was a weak correlation between fridge numbers and overall percentage ONeg use, there was no correlation with ONeg wastage.
Subject(s)
Blood Preservation , Data Collection , Erythrocyte Transfusion , Erythrocytes/cytology , Rh-Hr Blood-Group System , Female , Humans , Male , United KingdomABSTRACT
BACKGROUND: Radiologists require accurate clinical information to formulate reports. This is particularly relevant to computed tomography of the temporal bone, in which previous surgery can mimic disease. OBJECTIVES: The information provided with temporal bone computed tomography scan requests was evaluated. The study aimed to minimise inappropriate requests and improve the clinical value of reports. METHOD: A two-cycle prospective audit was undertaken using a proforma designed on the basis of national guidelines. Following the first cycle (in which the requests and reports of 100 scans were evaluated), new guidelines and training were implemented. A follow-up audit (of 50 scans) was then performed. RESULTS: Following intervention, the percentage of clinically relevant reports increased from 52 to 94 (p < 0.01), whilst unnecessary or inappropriate scan requests decreased from 11 to 2 per cent (p < 0.05). CONCLUSION: Optimising the clinical value of temporal bone computed tomography scan requests will have positive implications for patient care, time management and cost. The quality of the clinical information provided can have a significant impact on the clinical value of radiology reports, and can mean that unnecessary irradiation is avoided.
Subject(s)
Documentation/standards , Otolaryngology/standards , Temporal Bone/diagnostic imaging , Tomography, X-Ray Computed , Humans , Medical Audit , Prospective Studies , United KingdomABSTRACT
The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 µA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run, constituting approximately 4% of the data collected in the experiment, are reported here. From these initial results, the measured asymmetry is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in ep scattering. The small Q(2) of this experiment has made possible the first determination of the weak charge of the proton Q(W)(p) by incorporating earlier parity-violating electron scattering (PVES) data at higher Q(2) to constrain hadronic corrections. The value of Q(W)(p) obtained in this way is Q(W)(p)(PVES)=0.064±0.012, which is in good agreement with the standard model prediction of Q(W)(p)(SM)=0.0710±0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be Q(W)(n)(PVES+APV)=-0.975±0.010.
Subject(s)
Ear Diseases/surgery , Polyps/surgery , Suction/instrumentation , Equipment Design , HumansABSTRACT
Drug delivery to the ear is used to treat conditions of the middle and inner ear such as acute and chronic otitis media, Ménière's disease, sensorineural hearing loss and tinnitus. Drugs used include antibiotics, antifungals, steroids, local anesthetics and neuroprotective agents. A literature review was conducted searching Medline (1966-2012), Embase (1988-2012), the Cochrane Library and Ovid (1966-2012), using search terms 'drug delivery', 'middle ear', 'inner ear' and 'transtympanic'. There are numerous methods of drug delivery to the middle ear, which can be categorized as topical, systemic (intravenous), transtympanic and via the Eustachian tube. Localized treatments to the ear have the advantages of targeted drug delivery allowing higher therapeutic doses and minimizing systemic side effects. The ideal scenario would be a carrier system that could cross the intact tympanic membrane loaded with drugs or biochemical agents for the treatment of middle and inner ear conditions.
Subject(s)
Drug Delivery Systems , Ear Diseases/drug therapy , Administration, Oral , Administration, Topical , Animals , Ear/anatomy & histology , HumansABSTRACT
Botulinum toxin A (BT) is used therapeutically for the treatment of primary focal hyperhidrosis, a chronic debilitating condition characterised by over-activity of the eccrine sweat glands. Systemic toxicity concerns require BT to be administered by local injection, which in the case of hyperhidrosis means multiple painful intradermal injections by a skilled clinician at 6-monthly intervals. This study investigates the potential of a liquid-loaded pocketed microneedle device to deliver botulinum toxin A into the human dermis with the aim of reducing patient pain, improving therapeutic targeting and simplifying the administration procedure. Initially, ß-galactosidase was employed as a detectable model for BT to (i) visualise liquid loading of the microneedles, (ii) determine residence time of a liquid formulation on the device and (iii) quantify loaded doses. An array of five stainless steel pocketed microneedles was shown to possess sufficient capacity to deliver therapeutic doses of the potent BT protein. Microneedle-mediated intradermal delivery of ß-galactosidase and formaldehyde-inactivated botulinum toxoid revealed effective deposition and subsequent diffusion within the dermis. This study is the first to characterise pocketed microneedle delivery of a liquid formulation into human skin and illustrates the potential of such systems for the cutaneous administration of potent proteins such as BT. A clinically appropriate microneedle delivery system for BT could have a significant impact in both the medical and cosmetic industries.
Subject(s)
Botulinum Toxins, Type A/administration & dosage , Drug Delivery Systems/instrumentation , Skin/metabolism , Administration, Cutaneous , Botulinum Toxins, Type A/pharmacokinetics , Equipment Design , Humans , Needles , Skin/ultrastructure , beta-Galactosidase/administration & dosage , beta-Galactosidase/pharmacokineticsABSTRACT
BACKGROUND AND OBJECTIVES: A large proportion of all platelet components are given to haematology patients. As there are risks associated with their transfusion, costs associated with production, and shortages may occur, it is important that their use is appropriate. STUDY DESIGN AND METHODS: The study was split into two parts, a survey to assess local practice guidelines and an assessment of platelet usage. A total of 123 hospitals completed the survey and 168 hospitals submitted data of 40 haematology patients over a 3-month period. RESULTS: The organizational survey found that 36% of hospitals routinely give prophylactic platelet transfusions to patients with long-term bone-marrow failure. Also, a significant minority of hospitals administer platelet transfusions if the platelet count is below a certain threshold prior to performing a bone-marrow aspirate (11%) or a bone-marrow aspirate and trephine (23%); both of these are contrary to UK platelet transfusion guidelines. Data were collected on a total of 3402 patients, of which 3296 cases were eligible for analysis. They received approximately 46% of all platelet components issued to participating hospitals in England during the study period. The majority (69%) of platelet transfusions were prophylactic; of these only 33% were given when the platelet count was ≤10×10(9)/l. Using an algorithm, based on current UK guidelines, 60% of prophylactic transfusions were appropriate, 6% could not be assessed and 34% were inappropriate. A total of 10% of all prophylactic transfusions were double the standard adult dose. CONCLUSIONS: There is considerable potential for decreased use of platelet transfusions with a consequent improvement in their appropriate use and cost reduction.
Subject(s)
Hematologic Diseases/therapy , Platelet Transfusion/methods , Platelet Transfusion/standards , Aged , Algorithms , Female , Hematologic Diseases/blood , Humans , Male , Middle Aged , Platelet Count/standards , Platelet Transfusion/adverse effects , Platelet Transfusion/statistics & numerical data , Practice Guidelines as Topic , Risk FactorsABSTRACT
OBJECTIVE: Otitis media with effusion (OME), a common chronic childhood condition affecting hearing, is thought to be a result of bacterial infection, with biofilms recently implicated. Although bacterial DNA can be detected by polymerase chain reaction in 80% of patients, typically fewer than half of effusions are positive using standard culture techniques. We adopted an alternative approach to demonstrating bacteria in OME, using a bacterial viability stain and confocal laser scanning microscopy (CLSM): staining allows detection of live bacteria without requiring growth on culture, while CLSM allows demonstration of the three-dimensional structure typical of biofilms. METHODS: Effusion samples were collected at the time of ventilation tube insertion, analysed with CLSM and bacterial viability stain, and extended culture techniques performed with the intention of capturing all possible organisms. RESULTS: Sixty-two effusions (42 patients) were analysed: 28 (45.2%) were culture-positive, but 51 (82.3%) were CLSM-positive. Combining the two techniques demonstrated live bacteria in 57 (91.8%) samples. Using CLSM, bacteria exhibited biofilm morphology in 25 effusions and were planktonic in 26; the proportion of samples exhibiting biofilm morphology was similar in the culture-positive and culture-negative groups (50.0% and 48.3%, respectively). Biofilm samples contained an average of 1.7 different bacterial isolates and planktonic samples 2.0, with the commonest bacteria identified being coagulase-negative staphylococci. CONCLUSION: Live bacteria are present in most effusions, strongly suggesting that bacteria and biofilms are important in the aetiopathogenesis of OME.