Silver-doped calcium silicate sol-gel glasses with a cotton-wool-like structure for wound healing.

Skin has excellent capacity to regenerate, however, in the event of a large injury or burn skin grafts are required to aid wound healing. The regenerative capacity further declines with increasing age and can be further exacerbated with bacterial infection leading to a chronic wound. Engineered skin substitutes can be used to provide a temporary template for the damaged tissue, to prevent/combat bacterial infection and promote healing. In this study, the sol-gel process and electrospinning were combined to fabricate 3D cotton-wool-like sol-gel bioactive glass fibers that mimic the fibrous architecture of skin extracellular matrix (ECM) and deliver metal ions for antibacterial (silver) and therapeutic (calcium and silica species) actions for successful healing of wounds. This study investigated the effects of synthesis and process parameters, in particular sintering temperature on the fiber morphology, the incorporation and distribution of silver and the degradation rate of fibers. Silver nitrate was found to decompose into silver nanoparticles within the glass fibers upon calcination. Furthermore, with increasing calcination temperature the nanoparticles increased in size from 3 nm at 600 °C to ~25 nm at 800 °C. The antibacterial ability of the Ag-doped glass fibers decreased as a function of the glass calcination temperature. The degradation products from the Ag-doped 3D non-woven sol-gel glass fibers were also found to promote fibroblast proliferation thus demonstrating their potential for use in skin regeneration.

Life threatening abscess in the visceral space with penicillin and metronidazole resistant Prevotella Denticola following use of a laryngeal mask airway: case report.

BACKGROUND: Laryngeal mask airways (LMA) are commonly used for airway management. Complications with this device are rare. However, when they do occur, there is a high risk for respiratory problems, necessitating early diagnosis and treatment. We present the first case of a life-threatening abscess spreading in the visceral space caused by a penicillin and metronidazole resistant Prevotella Denticola after the use of an LMA. CASE PRESENTATION: A female patient was admitted to our day care centre for bunion surgery. A single use LMA size 3 (Solus®, intersurgical, Wokingham, Berkshire, United Kingdom) was successfully inserted. After surgery, the patient complained of a sore throat and amoxicillin was prescribed by the general practitioner. Three days after surgery the patient was admitted to the Intensive Care Unit (ICU) for obstructive breathing, due to an abscess in the visceral space. Retropharyngeal and certainly parapharyngeal abscesses in adults are already rare. This case however, is unique because it is the first case of abscess spreading into the visceral space after the use of an LMA. Amoxicillin/clavulanate and vancomycin were started. The abscess was incised 5 days later and microbiology showed 3 positive cultures of the anaerobe Prevotella denticola, resistant for penicillin and metronidazole, but sensitive for amoxicillin/clavulanate. The patient fully recovered. CONCLUSION: LMA's are easy to use and are established, safe tools to support ventilation of the airway. In this case, the authors hypothesise a small wound in the lateral pharyngeal wall probably created an opening into the visceral space causing infection with Prevotella denticola, supporting the idea that the pharyngeal mucosal space must be part of the visceral space. Additionally, early recognition and treatment of an LMA induced abscess is necessary to prevent evolution of complications leading to airway obstruction.

Validity of the 6-Minute Walk Test and YMCA Submaximal Cycle Test During Midpregnancy.

ABSTRACT: Tinius, RA, Blankenship, M, Maples, JM, Pitts, BC, Furgal, K, Norris, ES, Hoover, DL, Olenick, A, Lambert, J, and Cade, WT. Validity of the 6-minute walk test and Young Men's Christian Association (YMCA) submaximal cycle test during midpregnancy. J Strength Cond Res 35(11): 3236-3242, 2021-Submaximal exercise testing can be a feasible alternative to maximal testing within special populations to safely predict fitness levels; however, submaximal exercise testing has not been well-validated for use during pregnancy. The purpose of this study was to determine the concurrent validity of the 6-minute walk test (6MWT) and the YMCA submaximal cycle test (YMCAT) to predict V̇o2max in physically active women during midpregnancy. Thirty-seven (n = 37) pregnant women (22.1 ± 1.4 weeks' gestation) and 10 (n = 10) nonpregnant women participated in the study. Subjects completed a graded maximal treadmill test at 1 visit to measure maximal oxygen consumption (V̇o2max), and then subjects completed the 6MWT and YMCAT in randomized order during a separate visit. The predicted V̇o2max from each submaximal test were compared with the measured V̇o2max from the treadmill test to assess the validity of these tests during pregnancy. Among pregnant women, predicted V̇o2max from the YMCAT was not correlated to the measured V̇o2max (r = 0.14, p = 0.42), and the predicted V̇o2max from the 6MWT was only moderately correlated (r = 0.40, p = 0.016) to the measured V̇o2max. Among nonpregnant women, the predicted V̇o2max values from both the YMCAT and the 6MWT had strong correlations with the measured V̇o2max values (YMCAT: r = 0.71, p = 0.02; 6MWT: r = 0.80, p = 0.006). Neither test demonstrated concurrent validity among the pregnant sample. The main finding is that the YMCAT is not a valid method to estimate V̇o2max during midpregnancy (likely due to physiological changes in heart rate [HR] during pregnancy). The 6MWT has potential to be used clinically for estimating fitness as actual and predicted values did positively correlate, and it is not dependent on HR responses to exercise. However, if a precise measure of fitness is needed, then neither test appears to have strong validity for use during midpregnancy.

Electrospinning 3D bioactive glasses for wound healing.

An electrospinning technique was used to produce three-dimensional (3D) bioactive glass fibrous scaffolds, in the SiO2-CaO sol-gel system, for wound healing applications. Previously, it was thought that 3D cotton wool-like structures could only be produced from sol-gel when the sol contained calcium nitrate, implying that the Ca2+ and its electronic charge had a significant effect on the structure produced. Here, fibres with a 3D appearance were also electrospun from compositions containing only silica. A polymer binding agent was added to inorganic sol-gel solutions, enabling electrospinning prior to bioactive glass network formation and the polymer was removed by calcination. While the addition of Ca2+ contributes to the 3D morphology, here we show that other factors, such as relative humidity, play an important role in producing the 3D cotton-wool-like macrostructure of the fibres. A human dermal fibroblast cell line (CD-18CO) was exposed to dissolution products of the samples. Cell proliferation and metabolic activity tests were carried out and a VEGF ELISA showed a significant increase in VEGF production in cells exposed to the bioactive glass samples compared to control in DMEM. A novel SiO2-CaO nanofibrous scaffold was created that showed tailorable physical and dissolution properties, the control and composition of these release products are important for directing desirable wound healing interactions.

Osteogenic potential of sol-gel bioactive glasses containing manganese.

Bioactive glasses (BGs) are widely used for bone regeneration, and allow the incorporation of different ions with therapeutic properties into the glass network. Amongst the different ions with therapeutic benefits, manganese (Mn) has been shown to influence bone metabolism and activate human osteoblasts integrins, improving cell adhesion, proliferation and spreading. Mn has also been incorporated into bioceramics as a therapeutic ion for improved osteogenesis. Here, up to 4.4 mol% MnO was substituted for CaO in the 58S composition (60 mol% SiO2, 36 mol% CaO, 4 mol% P2O5) and its effects on the glass properties and capability to influence the osteogenic differentiation were evaluated. Mn-containing BGs with amorphous structure, high specific surface area and nanoporosity were obtained. The presence of Mn2+ species was confirmed by X-ray photoelectron spectroscopy (XPS). Mn-containing BGs presented no cytotoxic effect on human mesenchymal stem cells (hMSCs) and enabled sustained ion release in culture medium. hMSCs osteogenic differentiation stimulation and influence on the mineralisation process was also confirmed through the alkaline phosphatase (ALP) activity, and expression of osteogenic differentiation markers, such as collagen type I, osteopontin and osteocalcin, which presented higher expression in the presence of Mn-containing samples compared to control. Results show that the release of manganese ions from bioactive glass provoked human mesenchymal stem cell (hMSC) differentiation down a bone pathway, whereas hMSCs exposed to the Mn-free glass did not differentiate. Mn incorporation offers great promise for obtaining glasses with superior properties for bone tissue regeneration.

Effects of manganese incorporation on the morphology, structure and cytotoxicity of spherical bioactive glass nanoparticles.

Bioactive glass nanoparticles (BGNPs) are of great interest in tissue engineering as they possess high dissolution rate and capability of being internalized by cells, releasing their dissolution products with therapeutic benefits intracellularly. A modified Stöber process can be applied to obtain different BGNPs compositions containing therapeutic ions while maintaining controllable particle morphology, monodispersity and reduce agglomeration. Here, BGNPs containing Mn, an ion that has been shown to influence the osteoblast proliferation and bone mineralization, were evaluated. Particles with up to 142.3 ±â€¯10.8 nm and spherical morphology were obtained after MnO incorporation in the SiO2 - CaO system. X-ray photoelectron spectroscopy (XPS) indicated the presence of Mn2+ species and also a reduction in the number of bridging oxygen bonds due to the Ca and Mn. The Ca and Mn network modifier role on the silica network was also confirmed by magic-angle spinning 29Si solid-state nuclear magnetic resonance (MAS NMR). MTT evaluation showed no reduction in the mitochondrial metabolic activity of human mesenchymal stem cells exposed to the glass ionic products. Thus, evaluation showed that Mn could be incorporated into BGNPs by the modified Stöber method while maintaining their spherical morphology and features as a promising strategy for tissue regeneration.

Differential diagnosis of knee pain following a surgically induced lumbosacral plexus stretch injury. A case report.

Background and Purpose: Knee joint biomechanics requires an understanding of lower extremity (LE) segmental interactions. In some cases, knee pain may arise as a result of altered LE biomechanics; while in other cases, knee pain may stem from other causes, such as a peripheral nerve injury. Case Description: A 33-year-old woman presented via direct access for physical therapist (PT) examination with a chief complaint of left knee pain. The day after undergoing a dilation and curettage (D&C) procedure the patient had an acute onset of gait dysfunction. Over the next few days, the patient developed left anterior knee pain (7/10 at worst) in addition to a significant change in physical functioning (Lower Extremity Functional Scale [LEFS] 38/80). Physical examination revealed left LE weakness, altered sensation, and an absent Achilles deep tendon reflex. Outcomes: The patient's presentation was consistent with a lumbosacral plexus stretch injury, with S1 being most affected. A physiatrist was consulted and recommended initiating PT treatment with bi-weekly re-examination. The 6-week (14 visits) re-examination revealed abolished left knee pain and improved physical functioning (LEFS 66/80). Conclusion: Stretch injuries are a known complication of lithotomy positioning. Knowledge of this and the addition of a thorough examination allowed the PT to identify the possible cause of the patient's abrupt onset of left LE dysfunction. Regardless of mode of patient access, screening for referral is crucial and may include referral or, as in this case, consultation with other professionals.

Relative and Absolute Reliability of the Professionalism in Physical Therapy Core Values Self-Assessment Tool.

Development of professional behaviors in Doctor of Physical Therapy (DPT) students is an important part of professional education. The American Physical Therapy Association (APTA) has developed the Professionalism in Physical Therapy Core Values Self-Assessment (PPTCV-SA) tool to increase awareness of personal values in practice. The PPTCV-SA has been used to measure growth in professionalism following a clinical or educational experience. There are few studies reporting psychometric properties of the PPTCV-SA. The purpose of this study was to establish properties of relative reliability (intraclass correlation coefficient, iCC) and absolute reliability (standard error of measurement, SEM; minimal detectable change, MDC) of the PPTCV-SA. in this project, 29 first-year students in a DPT program were administered the PPTCVA-SA on two occasions, 2 weeks apart. Paired t-tests were used to examine stability in PPTCV-SA scores on the two occasions. iCCs were calculated as a measure of relative reliability and for use in the calculation of the absolute reliability measures of SEM and MDC. Results of paired t-tests indicated differences in the subscale scores between times 1 and 2 were non-significant, except for three subscales: Altruism (p=0.01), Excellence (p=0.05), and Social Responsibility (p=0.02). iCCs for test-retest reliability were moderate-to-good for all subscales, with SEMs ranging from 0.30 to 0.62, and MDC95 ranging from 0.83 to 1.71. These results can guide educators and researchers when determining the likelihood of true change in professionalism following a professional development activity.

A 'Learning conversation' as a style of feedback.

This article was migrated. The article was marked as recommended. This paper explores the history behind the introduction and use of a 'learning conversation' as a mechanism of providing effective feedback to students on resuscitation courses. The authors hope the use of this style of feedback may useful in many other contexts to provide authentic feedback. The central aim of a learning conversation is to promote and support greater self-awareness of the individual student in order to develop competence and team leadership through critical inquiry ( Harri-Augstein & Thomas 1991). Learning, particularly in the context of resuscitation is demonstrated by the utilisation of "planned experience which brings about a change of behaviour" and the process is facilitated by feedback whether during skills teaching, in workshops or in simulation. The learning conversation uses empathic, active respectful listening and discussion shared between a small group of participants, facilitated by an instructor to ensure that key learning emerges from this process duly informing future practice and behaviours. A mnemonic has been developed to facilitate acquisition of the skills involved in this feedback. Faculty also require feedback to fully develop their feedback skills but once established the process makes both faculty and students share their feelings, frustrations and learning in a very positive learning climate. The learning conversation has been in use in resuscitation courses for almost six years and the authors feel there is a wealth of literature available to support this approach which can be usefully applied to facilitate learning in many small group teaching settings and the process of delivering a Learning conversation is detailed within the paper.

Application of inelastic neutron scattering to studies of CO2 reforming of methane over alumina-supported nickel and gold-doped nickel catalysts.

The methane reforming reaction with carbon dioxide as the oxidant over alumina-supported nickel and gold-doped nickel catalysts is studied using a variety of techniques such as reaction testing, vibrational spectroscopy (inelastic neutron scattering (INS), Raman scattering and infrared absorption), temperature-programmed oxidation (TPO), transmission electron microscopy and X-ray powder diffraction. The quantities of retained carbon and hydrogen are determined by TPO and INS, respectively. Minimal hydrogen retention indicates these catalysts to be very efficient at cycling hydrogen. The relative partitioning of hydrogen within the reaction media is used to formulate a qualitative description of the reaction kinetics. The presence of the gold modifier does not appear to provide any improvement in catalyst performance under the specified reaction conditions.

The constructive use of images in medical teaching: a literature review.

This literature review illustrates the various ways images are used in teaching and the evidence appertaining to it and advice regarding permissions and use. Four databases were searched, 23 papers were retained out of 135 abstracts found for the study. Images are frequently used to motivate an audience to listen to a lecture or to note key medical findings. Images can promote observation skills when linked with learning outcomes, but the timing and relevance of the images is important - it appears they must be congruent with the dialogue. Student reflection can be encouraged by asking students to actually draw their own impressions of a course as an integral part of course feedback. Careful structured use of images improve attention, cognition, reflection and possibly memory retention.

Rhabdomyolysis in MDMA intoxication: a rapid and underestimated killer. "Clean" Ecstasy, a safe party drug?

BACKGROUND: Ecstasy is a popular drug among young adults. It is often thought to be safe. The dose of methylenedioxymethamphetamine (MDMA) in a tablet of Ecstasy varies greatly, and there is also a difference in individual response to a dose of MDMA. OBJECTIVES: To increase the awareness of potential mortality in MDMA use. CASE REPORT: We report the case of a patient with a lethal intoxication after pure MDMA intoxication. The serum toxicology screening showed an elevated level of MDMA (1.5 mg/L) but no other amphetamines or other drugs. CONCLUSIONS: The cause of death was a rapidly evolving hyperkalemia due to rhabdomyolysis. There is still a need to educate the public about the dangers of this so-called "safe" party drug.

Human factors in resuscitation teaching.

INTRODUCTION: There is an increasing interest in human factors within the healthcare environment reflecting the understanding of their impact on safety. The aim of this paper is to explore how human factors might be taught on resuscitation courses, and improve course outcomes in terms of improved mortality and morbidity for patients. The delivery of human factors training is important and this review explores the work that has been delivered already and areas for future research and teaching. METHOD: Medline was searched using MESH terms Resuscitation as a Major concept and Patient or Leadership as core terms. The abstracts were read and 25 full length articles reviewed. RESULTS: Critical incident reporting has shown four recurring problems: lack of organisation at an arrest, lack of equipment, non functioning equipment, and obstructions preventing good care. Of these, the first relates directly to the concept of human factors. Team dynamics for both team membership and leadership, management of stress, conflict and the role of debriefing are highlighted. Possible strategies for teaching them are discussed. CONCLUSIONS: Four strategies for improving human factors training are discussed: team dynamics (including team membership and leadership behaviour), the influence of stress, debriefing, and conflict within teams. This review illustrates how human factor training might be integrated further into life support training without jeopardising the core content and lengthening the courses.

The associations between air quality and the number of hospital admissions for acute pain and sickle-cell disease in an urban environment.

The clinical severity of sickle-cell disease (SCD) is dependent on genetic and environmental variables. Environmental factors have been poorly studied. We have investigated possible links between air pollution and acute pain in SCD. We retrospectively studied the numbers of daily admissions with acute sickle-cell pain to King's College Hospital, London, in relation to local daily air quality measurements. We analysed 1047 admissions over 1400 d (1st January 1998-31st October 2001). Time series analysis was performed using the cross-correlation function (CCF). CCF showed a significant association between increased numbers of admissions and low levels of nitric oxide (NO), low levels of carbon monoxide (CO) and high levels of ozone (O(3)). There was no association with sulphur dioxide (SO(2)), nitrogen dioxide or PM(10) (dust). The significant results were further examined using quartile analysis. This confirmed that high levels of O(3) and low levels of CO were associated with increased numbers of hospital admissions. Low NO levels were also associated with increased admissions but did not reach statistical significance on quartile analysis. Our study suggests air quality has a significant effect on acute pain in SCD and that patients should be counselled accordingly. The potential beneficial effect of CO and NO is intriguing and requires further investigation.

Safety and efficacy of buccal midazolam versus rectal diazepam for emergency treatment of seizures in children: a randomised controlled trial.

BACKGROUND: Rectal diazepam and buccal midazolam are used for emergency treatment of acute febrile and afebrile (epileptic) seizures in children. We aimed to compare the safety and efficacy of these drugs. METHODS: A multicentre, randomised controlled trial was undertaken to compare buccal midazolam with rectal diazepam for emergency-room treatment of children aged 6 months and older presenting to hospital with active seizures and without intravenous access. The dose varied according to age from 2.5 to 10 mg. The primary endpoint was therapeutic success: cessation of seizures within 10 min and for at least 1 hour, without respiratory depression requiring intervention. Analysis was per protocol. FINDINGS: Consent was obtained for 219 separate episodes involving 177 patients, who had a median age of 3 years (IQR 1-5) at initial episode. Therapeutic success was 56% (61 of 109) for buccal midazolam and 27% (30 of 110) for rectal diazepam (percentage difference 29%, 95% CI 16-41). Analysing only initial episodes revealed a similar result. The rate of respiratory depression did not differ between groups. When centre, age, known diagnosis of epilepsy, use of antiepileptic drugs, prior treatment, and length of seizure before treatment were adjusted for with logistic regression, buccal midazolam was more effective than rectal diazepam. INTERPRETATION: Buccal midazolam was more effective than rectal diazepam for children presenting to hospital with acute seizures and was not associated with an increased incidence of respiratory depression.