Estimation of differential pathlength factor from NIRS measurement in skeletal muscle.

The utilization of continuous wave (CW) near-infrared spectroscopy (NIRS) device to measure non-invasively muscle oxygenation in healthy and disease states is limited by the uncertainties related to the differential path length factor (DPF). DPF value is required to quantify oxygenated and deoxygenated heme groups' concentration changes from measurement of optical densities by NIRS. An integrated approach that combines animal and computational models of oxygen transport and utilization was used to estimate the DPF value in situ. The canine model of muscle oxidative metabolism allowed measurement of both venous oxygen content and tissue oxygenation by CW NIRS under different oxygen delivery conditions. The experimental data obtained from the animal model were integrated in a computational model of O2 transport and utilization and combined with Beer-Lambert law to estimate DPF value in contracting skeletal muscle. A 2.1 value was found for DPF by fitting the mathematical model to the experimental data obtained in contracting muscle (T3) (Med.Sci.Sports.Exerc.48(10):2013-2020,2016). With the estimated value of DPF, model simulations well predicted the optical density measured by NIRS on the same animal model but with different blood flow, arterial oxygen contents and contraction rate (J.Appl.Physiol.108:1169-1176, 2010 and 112:9-19,2013) and demonstrated the robustness of the approach proposed in estimating DPF value. The approach used can overcome the semi-quantitative nature of the NIRS and estimate non-invasively DPF to obtain an accurate concentration change of oxygenated and deoxygenated hemo groups by CW NIRS measurements in contracting skeletal muscle under different oxygen delivery and contraction rate.

Determination of the absolute intensity of the 1205 keV γ-ray emission from 91Y.

A radiochemically pure solution of 91Y was produced by the thermal neutron fission of 235U followed by successive chemical separations to remove fission product impurities. The gamma emission rate of the 91Y 1205 keV gamma was measured using multiple high purity germanium gamma spectrometers previously calibrated for counting efficiency using a certificated mixed nuclide gamma standard. The activity concentration of the 91Y was subsequently standardised by liquid scintillation counting. From the combination the activity concentration and gamma emission intensity, the absolute intensity of the 1205 keV gamma emission was derived as 0.2297(39)%. This data agrees within the quoted uncertainties with the absolute intensity of 0.26(4)% published in nuclear data sheets A=91 (Baglin, 2013), but reduces the uncertainty by an order of magnitude.

A plastic scintillator and HPGe ß-γ coincidence detection system.

A network of specialist laboratories support the International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) with re-measurements of radionuclide samples, including xenon gas. The measurement of four xenon fission product radionuclides (133Xe, 135Xe, 131mXe and 133mXe) can be used to detect an underground nuclear explosion. Laboratories use a range of techniques to measure the radionuclides, including beta-gamma (ß-γ) coincidence spectrometry. These highly-sensitive measurements are capable of detecting concentrations of down to 500 atoms of 133Xe in a few cm3 of xenon. In some detector systems, detection of the metastable isomers (131mXe and 133mXe) can be more challenging due to interferences between the signatures of different radionuclides. Recent work has shown that using high-purity Germanium (HPGe) high-resolution gamma detectors, these interferences can be reduced, lowering the dependence of the detection limits on radionuclide sample isotopic composition. One downside of these detectors is the reduction in detection efficiency, which impacts the overall detection sensitivity; so assessing different detector systems is a priority for radionuclide laboratories. This work presents a coincidence detector system comprising of a plastic scintillator gas cell and a large-crystal high-purity germanium detector. The energy resolution, coincidence detection efficiency, MDA and interference factors are determined from measurements of synthetic radioxenon gas samples.

Third international challenge to model the medium- to long-range transport of radioxenon to four Comprehensive Nuclear-Test-Ban Treaty monitoring stations.

In 2015 and 2016, atmospheric transport modeling challenges were conducted in the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification, however, with a more limited scope with respect to emission inventories, simulation period and number of relevant samples (i.e., those above the Minimum Detectable Concentration (MDC)) involved. Therefore, a more comprehensive atmospheric transport modeling challenge was organized in 2019. Stack release data of Xe-133 were provided by the Institut National des Radioéléments/IRE (Belgium) and the Canadian Nuclear Laboratories/CNL (Canada) and accounted for in the simulations over a three (mandatory) or six (optional) months period. Best estimate emissions of additional facilities (radiopharmaceutical production and nuclear research facilities, commercial reactors or relevant research reactors) of the Northern Hemisphere were included as well. Model results were compared with observed atmospheric activity concentrations at four International Monitoring System (IMS) stations located in Europe and North America with overall considerable influence of IRE and/or CNL emissions for evaluation of the participants' runs. Participants were prompted to work with controlled and harmonized model set-ups to make runs more comparable, but also to increase diversity. It was found that using the stack emissions of IRE and CNL with daily resolution does not lead to better results than disaggregating annual emissions of these two facilities taken from the literature if an overall score for all stations covering all valid observed samples is considered. A moderate benefit of roughly 10% is visible in statistical scores for samples influenced by IRE and/or CNL to at least 50% and there can be considerable benefit for individual samples. Effects of transport errors, not properly characterized remaining emitters and long IMS sampling times (12-24 h) undoubtedly are in contrast to and reduce the benefit of high-quality IRE and CNL stack data. Complementary best estimates for remaining emitters push the scores up by 18% compared to just considering IRE and CNL emissions alone. Despite the efforts undertaken the full multi-model ensemble built is highly redundant. An ensemble based on a few arbitrary runs is sufficient to model the Xe-133 background at the stations investigated. The effective ensemble size is below five. An optimized ensemble at each station has on average slightly higher skill compared to the full ensemble. However, the improvement (maximum of 20% and minimum of 3% in RMSE) in skill is likely being too small for being exploited for an independent period.

Detection of subtle cartilage and bone tissue degeneration in the equine joint using polarisation-sensitive optical coherence tomography.

OBJECTIVE: To explore the ability of polarisation-sensitive optical coherence tomography (PS-OCT) to rapidly identify subtle signs of tissue degeneration in the equine joint. METHOD: Polarisation-sensitive optical coherence tomography (PS-OCT) images were systematically acquired in four locations along the medial and lateral condyles of the third metacarpal bone in five dissected equine specimens. Intensity and retardation PS-OCT images, and anomalies observed therein, were then compared and validated with high resolution images of the tissue sections obtained using Differential Interference contrast (DIC) optical light microscopy. RESULTS: The PS-OCT system was capable of imaging the entire equine osteochondral unit, and allowed delineation of the three structurally differentiated zones of the joint, that is, the articular cartilage matrix, zone of calcified cartilage and underlying subchondral bone. Importantly, PS-OCT imaging was able to detect underlying matrix and bone changes not visible without dissection and/or microscopy. CONCLUSION: PS-OCT has substantial potential to detect, non-invasively, sub-surface microstructural changes that are known to be associated with the early stages of joint tissue degeneration.

Determination of the 161Tb half-life.

There is significant interest in the use of terbium radioisotopes for applications in cancer therapy and diagnosis. Of these, 161Tb, as a medium energy beta-emitter, is being investigated as a potential alternative to 177Lu. The relatively high proportion of conversion electron and Auger electron emissions per decay make 161Tb an attractive targeted therapeutic. As a product of nuclear fission, 161Tb is also of importance to nuclear forensics. The standard uncertainty of the current evaluated half-life of 6.89(2) d contributes significantly to the standard uncertainty of any decay corrected activity determination made. Furthermore, the accuracy of this evaluated half-life has been called into question by measurements reported in 2020 at the Institute of Radiation Physics (IRA), Switzerland, who reported a half-life of 6.953(2) d. In the current work, the half-life of the 161Tb ground state decay has been measured at three independent laboratories located in the United Kingdom and the United States of America for a total of six determinations using three independent measurement techniques; gamma-ray spectrometry, ionisation chamber measurement and liquid scintillation counting. The half-life determined for 161Tb of 6.9637(29) d confirms the observed 1% relative increase observed by IRA, though the reported half-lives in this work and at IRA are significantly different (ζ-score = 3.1).

Recruitment and Consent in an observational study.

OBJECTIVE: The study sought to explore the consent rate and associated potential bias across a cohort in a large longitudinal population based study. RESEARCH DESIGN: Data were taken from a study designed to examine the effects of the reintroduction of community water fluoridation on children's oral health over a five-year period. Children were recruited from a fluoridated and non-fluoridated area in Cumbria, referred to as Group 1 and Group 2. RESULTS: Data were available for 3138 individuals. The consent rate was 12.91 percentage points lower in Group 2 than Group 1 (95% CI -16.27 to -9.56, p⟨0.001). The population in Group 2 was more deprived (higher Index of Multiple Deprivation (IMD)) than Group 1 before consent was taken. Consent was not associated with deprivation in either group. CONCLUSION: The cohort appeared to be unaffected by IMD-related non-consent. However there was a difference in consent rate between the two groups. With the population in Group 1 being more deprived than Group 2, it will be important to incorporate these differences into the analysis at the end of this longitudinal study.

CRISPR-based gene editing enables FOXP3 gene repair in IPEX patient cells.

The prototypical genetic autoimmune disease is immune dysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome, a severe pediatric disease with limited treatment options. IPEX syndrome is caused by mutations in the forkhead box protein 3 (FOXP3) gene, which plays a critical role in immune regulation. As a monogenic disease, IPEX is an ideal candidate for a therapeutic approach in which autologous hematopoietic stem and progenitor (HSPC) cells or T cells are gene edited ex vivo and reinfused. Here, we describe a CRISPR-based gene correction permitting regulated expression of FOXP3 protein. We demonstrate that gene editing preserves HSPC differentiation potential, and that edited regulatory and effector T cells maintain their in vitro phenotype and function. Additionally, we show that this strategy is suitable for IPEX patient cells with diverse mutations. These results demonstrate the feasibility of gene correction, which will be instrumental for the development of therapeutic approaches for other genetic autoimmune diseases.

Imaging hepatic angiomyolipomas: key features and avoiding errors.

Hepatic angiomyolipomas (HAMLs) are rare mesenchymal neoplasms, which have highly variable imaging appearances, often leading to misdiagnosis. They belong to the family of perivascular epithelioid cell neoplasms (PEComas). HAMLs have a wide spectrum of imaging appearances due to variable amounts of smooth muscle cells, adipose tissue, and blood vessels in their makeup. Although typically sporadic, they are also associated with tuberous sclerosis. Sporadic lesions tend to be solitary whilst patients with tuberous sclerosis often have multiple HAMLs invariably accompanied by renal AMLs. Having been originally considered benign hamartomas, increasing reports of complications, including malignant behaviour, has also resulted in uncertainty in regard to their optimal management. Typically described imaging characteristics are of a hypervascular fat-containing lesion with prominent intratumoural vessels and an early draining vein; however HAMLs commonly demonstrate a paucity of fat or wash-out on contrast-enhanced imaging, and not all HAML lesions are hypervascular. HAMLs can therefore easily be misdiagnosed as other hepatic lesions, in particular hepatocellular carcinoma. This review describes the imaging characteristics of HAMLs, illustrating the wide variety of potential appearances across ultrasound, contrast-enhanced ultrasound, computed tomography, and magnetic resonance imaging, and highlights the challenges and potential errors that can be made. This review will aid radiologists in avoiding potentially major pitfalls when faced with this rare but important liver pathology.

Percutaneous transhepatic Laser lithotripsy for intrahepatic cholelithiasis.

PURPOSE: To report the technical success, complications and long-term outcomes of patients with intrahepatic cholelithiasis not amenable to endoscopic retrograde cholangiopancreatography (ERCP) who were treated with percutaneous transhepatic biliary Laser lithotripsy (PTBLL). PATIENTS AND METHODS: A retrospective review of 12 patients who underwent PTBLL for intrahepatic cholelithiasis was performed. There were 5 men and 7 women with a mean age of 46±18 (SD) years (range: 23-75 years). PTBLL was performed when stone clearance using ERCP had previously failed or was not appropriate due to unfavourable anatomy or the presence of multiple stones or a large stone. Percutaneous biliary access into intrahepatic ducts was obtained if not already present and lithotripsy was performed using a HolmiumYAG 2100nM Laser. Patients files were analyzed to determine the technical success, complications and long-term outcomes. RESULTS: Eleven patients (11/12; 92%) had a history of previous hepatobiliary surgery and nine (9/12; 75%) had multiple stones confirmed on preprocedure imaging. A 100% success rate in fragmenting the target stone(s) was achieved and 11/12 patients (92%) had successful first pass extraction of target stone fragments. Two patients (2/12; 17%) required repeat lithotripsy. One patient (1/12; 8%) experienced a major complication in the form of cholangitis. Of patients with long-term follow-up, 4/10 (40%) had recurrence of intrahepatic calculi with a mean time interval of 31 months (range 3-84 months). CONCLUSION: For patients with intrahepatic biliary calculi not amenable to ERCP, PTBLL provides an effective and safe alternate treatment.

Stable isotopic characterization of a coastal floodplain forest community: a case study for isotopic reconstruction of Mesozoic vertebrate assemblages.

Stable isotopes are powerful tools for elucidating ecological trends in extant vertebrate communities, though their application to Mesozoic ecosystems is complicated by a lack of extant isotope data from comparable environments/ecosystems (e.g. coastal floodplain forest environments, lacking significant C4 plant components). We sampled 20 taxa across a broad phylogenetic, body size, and physiological scope from the Atchafalaya River Basin of Louisiana as an environmental analogue to the Late Cretaceous coastal floodplains of North America. Samples were analysed for stable carbon, oxygen and nitrogen isotope compositions from bioapatite and keratin tissues to test the degree of ecological resolution that can be determined in a system with similar environmental conditions, and using similar constraints, as those in many Mesozoic assemblages. Isotopic results suggest a broad overlap in resource use among taxa and considerable terrestrial-aquatic interchange, highlighting the challenges of ecological interpretation in C3 systems, particularly when lacking observational data for comparison. We also propose a modified oxygen isotope-temperature equation that uses mean endotherm and mean ectotherm isotope data to more precisely predict temperature when compared with measured Atchafalaya River water data. These results provide a critical isotopic baseline for coastal floodplain forests, and act as a framework for future studies of Mesozoic palaeoecology.

Benefits of the epilepsy specialist nurses (ESN) role, standardized practices and education around the world.

Epilepsy, often considered as a stigmatizing disease, affects 65 million people worldwide and is frequently associated with comorbidities that increase both direct and indirect costs. The degree of impact on quality of life and the cost of care differs depending on the social and health care organizations in place, political, medico-economic and/or socio-cultural contexts. Across the globe, healthcare is provided by nurses in primary care, urgent or emergency care, and within specialized domains of practice. In Epilepsy the global care could be enhanced by developing standardized nursing education in close collaboration with other caregivers. The impact of epilepsy nursing care has been documented in some developed countries, but the diversity of nursing practices and professional education of nurses raise difficulties in generalizing these findings. Specialized education in epilepsy will improve access, treatment and ultimately the quality of life of patients.

The provision of care to adults with an intellectual disability in the UK. A Special report from the intellectual disability UK chapter ILAE.

PURPOSE: This article reflects the report by the British Branch of the International League Against Epilepsy (ILAE) Working Group on services for adults with epilepsy and intellectual disability (ID). Its terms of reference was to explore the current status of aspects of the care of people with an ID and epilepsy. METHODS: Survey content was developed from key themes identified by consensus of the working group. An electronic survey was distributed via email. The sample population was the membership of the ILAE UK, Royal College of Psychiatrists (RCPsych) Faculty of ID, Epilepsy Nurses Association (ESNA), and the Association of British Neurologists (ABN). Following a six week response period the data was then collated, anonymised and distributed to the working group in order that opinion statements could be gathered. RESULTS: The time taken for individuals with both new-onset and established epilepsy to undergo routine investigation was commonly at least 1-3 months, far beyond recommendations made by NICE (CG20). A small minority of clinicians would not consider non-pharmacological interventions including epilepsy surgery, vagus nerve stimulation, and ketogenic diet for this population. Almost universally responders are actively involved in the assessment and management of key risk areas including risk of drowning, hospitalization, medication side effects, and sudden unexpected death in epilepsy (SUDEP). CONCLUSION: This investigation identifies key themes and recommendations relating to care delivery and meeting the complex needs of people with ID and epilepsy. Adults with ID and epilepsy appear to exist in a unique, but inadequate, segment of epilepsy care delivery.

NHS dental service utilisation and social deprivation in older adults in North West England.

Objective To explore NHS dental service utilisation (attendance and treatment activity) of older adults.Design Retrospective analysis of dental treatment claim forms (FP17s) over a 15 month period.Population A total of 690,433 older adults in North West England.Results NHS dental care attendance decreased with increasing age; 49% in 65-74 years, 39% in 75-84 years and 23% in the over 85 years age group. Across all older age stratifications, the more deprived patients had a higher rate of examinations, extractions, dentures and preventative advice compared to the least deprived patients. However, the relationship was opposite for the rate of fillings and complex restorative treatment; the rate was higher for the least deprived older adult patients.Conclusions Despite 95% of older adults living in the community, the number of older adults accessing NHS dental care in this data set is thought-provoking. Additionally, there is a complex relationship between the type of treatment provided and the patient's IMD level. The authors acknowledge the major limitations of this dataset; affluent people are more likely to access private dental care and the availability of NHS dental services is likely to vary across different regions. However, the use of 'big data' is necessary to provide a pragmatic approach for future research in the management of older adults in general dental services.

Sugar before bed: a simple dietary risk factor for caries experience.

Clinical care pathways have placed renewed emphasis on caries risk assessment and the ability to predict and prevent further disease. With diet considered a key factor in the development of caries, the level of caries risk posed by dietary habits, such as the frequency of intake and timing of free sugars is questioned. OBJECTIVE: To identify reliable and simple dietary risk factors for caries experience. RESEARCH DESIGN: A cross-sectional observational study of a convenience sample with data gained from clinical examinations, questionnaire and a 24 hour dietary-recall interview. PARTICIPANTS: 128 subjects aged 11-12 from comprehensive schools in Greater Manchester and Newcastle upon-Tyne, UK. OUTCOME MEASURES: free sugars consumed between meals, before bed and total % of total free sugars consumed were assessed from dietary assessments led by a dietitian. D4-6MFT was generated with a caries threshold of ICDAS stage 4 from clinical examinations. RESULTS: Analysis revealed no significant differences in caries experience when looking specifically at caries into dentine, referred to as the cavity group (split at D4-6MFT), between high and low deprivation, consumption of free sugars between meals and free sugars (%). The consumption of free sugars within the hour before bed revealed a statistically significant difference between the cavity/no cavity groups (p=0.002). Logistic regression analysis on the cavity/no cavity groups revealed an odds ratio of 2.4 (95%CI 1.3,4.4) for free sugars consumption before bedtime. CONCLUSIONS: The study suggests that the consumption of free sugars before bedtime may be an important risk factor for adolescent caries into dentine experience.

Prevalence and severity of dental fluorosis in four English cities.

OBJECTIVE: To assess the prevalence and severity of dental fluorosis in four city-based populations using a robust photographic method with TF index reporting; and to record the aesthetic satisfaction scores of children in all four cities. BASIC RESEARCH DESIGN: Cross sectional epidemiological survey (surveillance). PARTICIPANTS: 1,904 children aged 11-14 years, in four English cities. INTERVENTIONS: Two cities were served by community water fluoridation schemes supplying water at 1mg/l F. The other two cities did not have water fluoridation schemes and had low levels of fluoride naturally present. MAIN OUTCOME MEASURES: The prevalence and severity of dental fluorosis. Scoring was undertaken using high quality digital images by a single calibrated examiner. RESULTS: Data suggest that the prevalence of fluorosis at levels greater than TF2 are broadly similar to previous studies (F 10%, NF 2%), with an apparent increase in the total number of TF1 cases across both fluoridated (41%) and non-fluoridated cities (32%) with a commensurate decrease in TF0 (F 39%, NF 63%). Data suggest that the proportion of children expressing dissatisfaction with the appearance of their teeth is the same in fluoridated and non-fluoridated communities although the reasons for this may differ. CONCLUSIONS: The levels of fluorosis that might be considered of aesthetic concern are low and stable while the increase in TF1 may be due to an increase in self- and professionally-applied fluoride products or the increased sensitivity afforded by the digital imaging system. It is not however a public health problem or concern. Further monitoring appears justified.

Role of information in preparing men for transrectal ultrasound guided prostate biopsy: a qualitative study embedded in the ProtecT trial.

BACKGROUND: The histological diagnosis of prostate cancer requires a prostate needle biopsy. Little is known about the relationship between information provided to prepare men for transrectal ultrasound guided biopsy (TRUS-Bx) and how men experience biopsy. The objectives were a) to understand men's experiences of biopsy as compared to their expectations; and b) to propose current evidence-based information for men undergoing TRUS-Bx. METHODS: Between February 2006 and May 2008, 1,147 men undergoing a standardised 10-core transrectal ultrasound guided biopsy protocol under antibiotic cover following a PSA 3.0-19.9 ng/ml in the Prostate Testing for Cancer and Treatment (ProtecT) trial, completed questionnaires about biopsy symptoms. In this embedded qualitative study, in-depth interviews were undertaken with 85 men (mean age 63.6 yrs, mean PSA 4.5 ng/ml) to explore men's experiences of prostate biopsy and how the experience might be improved. Interview data were analysed thematically using qualitative research methods. Findings from the qualitative study were used to guide selection of key findings from the questionnaire study in developing a patient information leaflet preparing men for biopsy. RESULTS: Although most men tolerated TRUS-Bx, a quarter reported problematic side-effects and anxiety. Side effects were perceived as problematic and anxiety arose most commonly when experiences deviated from information provided. Men who were unprepared for elements of TRUS-Bx procedure or its sequelae responded by contacting health professionals for reassurance and voiced frustration that pre-biopsy information had understated the possible severity or duration of pain/discomfort and bleeding. Findings from questionnaire and interview data were combined to propose a comprehensive, evidence-based patient information leaflet for TRUS-Bx. CONCLUSIONS: Men reported anxiety associated with TRUS-Bx or its side-effects most commonly if they felt inadequately prepared for the procedure. Data from this qualitative study and the previous questionnaire study have been used to propose an updated, comprehensive evidence-based set of information for men undergoing TRUS-Bx.

The impact of CBCT imaging when placing dental implants in the anterior edentulous mandible: a before-after study.

OBJECTIVES: To evaluate the impact of CBCT imaging when placing dental implants in the anterior edentulous mandible, using a "before-after" study design. METHODS: Eight dental practitioners, who regularly place dental implants in independent dental practice in the North West of England, were presented with realistic simulations of four edentulous cases. The practitioners were asked to assess case difficulty, select implants and then drill osteotomies in preparation for dental implants in the lower canine regions to support a complete overdenture. In the "before" part of the study, a panoramic and a trans-symphyseal view were available. In the "after" part of the study, a CBCT image was added. Perception of case difficulty, implant selection and the incidence of perforations or "near miss perforations" of the lingual cortical plate were recorded. Two cases were regarded as "regular" and two as "challenging". RESULTS: In challenging cases, the availability of CBCT led practitioners to select narrower implants and to assess cases as more difficult. In the challenging cases only, there were fewer perforations of the lingual cortical plate after the availability of CBCT, but this difference was not statistically significant. There were no perforations in the regular cases either before or after the availability of CBCT. CONCLUSIONS: Perception of case difficulty and implant selection are of importance only if they change the outcome for the patient. This study provided weak evidence that CBCT is helpful in avoiding perforations in challenging cases. The availability of CBCT had no impact in regular cases.

A patient with acute liver failure and extreme hypoglycaemia with lactic acidosis who was not in a coma: causes and consequences of lactate-protected hypoglycaemia.

Lactate can substitute for glucose as a metabolic substrate. We report a patient with acute liver failure who was awake despite a glucose level of 0.7 mmol/l with very high lactate level of 25 mmol/l. The hypoglycaemia+hyperlactataemia combination may be considered paradoxical since glucose is the main precursor of lactate and lactate is reconverted into glucose by the Cori cycle. Literature relevant to the underlying mechanism of combined deep hypoglycaemia and severe hyperlactataemia was assessed. We also assessed the literature for evidence of protection against deep hypoglycaemia by hyperlactataemia. Four syndromes demonstrating hypoglycaemia+hyperlactataemia were found: 1) paracetamol-induced acute liver failure, 2) severe malaria, 3) lymphoma and 4) glucose-6-phosphatase deficiency. An impaired Cori cycle is a key component in all of these metabolic states. Apparently the liver, after exhausting its glycogen stores, loses the gluconeogenic pathway to generate glucose and thereby its ability to remove lactate as well. Several patients with lactic acidosis and glucose levels below 1.7 mmol/l who were not in a coma have been reported. These observations and other data coherently indicate that lactate-protected hypoglycaemia is, at least transiently, a viable state under experimental and clinical conditions. Severe hypoglycaemia+hyperlactataemia reflects failure of the gluconeogenic pathway of lactate metabolism. The existence of lactate-protected hypoglycaemia implies that patients who present with this metabolic state should not automatically be considered to have sustained irreversible brain damage. Moreover, therapies that aim to achieve hypoglycaemia might be feasible with concomitant hyperlactataemia.

Conventional radiography and cross-sectional imaging when planning dental implants in the anterior edentulous mandible to support an overdenture: a systematic review.

The objectives for this systematic review were to determine if the pre-operative availability of cross-sectional imaging, such as cone beam CT, has a diagnostic impact, therapeutic impact or impact on patients' outcome when placing two dental implants in the anterior mandible to support an overdenture. The Cochrane Oral Health Group's Trials Register (CENTRAL), MEDLINE® and Embase were searched up to, and including, February 2013. Studies were considered eligible for inclusion if they compared the impact of conventional and cross-sectional imaging when placing dental implants in sites including the anterior mandible. An adapted quality assessment tool was used for the assessment of the risk of bias in included studies. Pooled quantitative analysis was not possible and, therefore, synthesis was qualitative. Of 2374 potentially eligible papers, 5 studies were included. Little can be determined from a synthesis of these studies because of their small number, clinical diversity and high risks of bias. Notwithstanding, it may be tentatively inferred that cross-sectional imaging has a therapeutic impact in the more challenging cases. In terms of impact, this review has found no evidence to support any specific imaging modality when planning dental implant placement in any region of the mouth. Therefore, those who argue that cross-sectional imaging should be used for the assessment of all dental implant sites are unsupported by evidence.