Pyroglutamic acidosis caused by the combination of two common medicines prescribed in everyday practice

We present the case of a 71-year-old female treated for infective endocarditis with flucloxacillin and paracetamol. Her clinical course became complicated by a blood-gas demonstrating a raised anion gap metabolic acidosis. The patient was diagnosed with pyroglutamic metabolic acidosis. This is a rare interaction between high dose flucloxacillin and paracetamol, and is an important complication to recognize.

Short-term risk prediction after major lower limb amputation: PERCEIVE study

BACKGROUND

The accuracy with which healthcare professionals (HCPs) and risk prediction tools predict outcomes after major lower limb amputation (MLLA) is uncertain. The aim of this study was to evaluate the accuracy of predicting short-term (30 days after MLLA) mortality, morbidity, and revisional surgery.

METHODS

The PERCEIVE (PrEdiction of Risk and Communication of outcomE following major lower limb amputation: a collaboratIVE) study was launched on 1 October 2020. It was an international multicentre study, including adults undergoing MLLA for complications of peripheral arterial disease and/or diabetes. Preoperative predictions of 30-day mortality, morbidity, and MLLA revision by surgeons and anaesthetists were recorded. Probabilities from relevant risk prediction tools were calculated. Evaluation of accuracy included measures of discrimination, calibration, and overall performance.

RESULTS

Some 537 patients were included. HCPs had acceptable discrimination in predicting mortality (931 predictions; C-statistic 0.758) and MLLA revision (565 predictions; C-statistic 0.756), but were poor at predicting morbidity (980 predictions; C-statistic 0.616). They overpredicted the risk of all outcomes. All except three risk prediction tools had worse discrimination than HCPs for predicting mortality (C-statistics 0.789, 0.774, and 0.773); two of these significantly overestimated the risk compared with HCPs. SORT version 2 (the only tool incorporating HCP predictions) demonstrated better calibration and overall performance (Brier score 0.082) than HCPs. Tools predicting morbidity and MLLA revision had poor discrimination (C-statistics 0.520 and 0.679).

CONCLUSION

Clinicians predicted mortality and MLLA revision well, but predicted morbidity poorly. They overestimated the risk of mortality, morbidity, and MLLA revision. Most short-term risk prediction tools had poorer discrimination or calibration than HCPs. The best method of predicting mortality was a statistical tool that incorporated HCP estimation.

Three Cases Highlighting Three Potential Pitfalls in the Platelet Refractory Workup

Introduction/Objective

Platelet refractory (PR) patients do not achieve expected post-transfusion platelet counts. We investigate such patients with a post-transfusion platelet count, indirect Platelet Antibody Screen (ind-PAS), Class I HLA Antibody (HLA-Ab) testing, and platelet crossmatch (PXM). The following three cases highlight potential pitfalls of laboratory investigations for PR patients.

Methods/Case Report

Case #1 (57-year-old male with AML) revealed discrepant predicted and observed donor compatibility. Antibody testing demonstrated no platelet glycoprotein antibodies and HLA-ab to B13, corresponding to 4% calculated PRA (CPRA), indicating 96% predicted donor compatibility. However, PXM revealed that the patient was compatible with 11/14 (79%) screened donors. Communication with the reference laboratory revealed that two PXM incompatible units were ABO incompatible. Case #2 (27-year-old female with aplastic anemia) is a highly sensitized patient (99% CPRA). PXM revealed compatibility with 1/14 screened donors; however, she failed to respond to the compatible donor. To investigate this poor response, patient’s plasma was tested against HLA incompatible donors. Neat serum demonstrated compatibility with all donors, whereas 1:8 dilution resulted in positive crossmatches with half the donors. The false negative crossmatches are likely explained by prozone in the setting of high HLA-ab burden. Case #3 (79-year-old male with AML) demonstrated a discrepancy between the ind-PAS (PakPlus, Immucor), which was negative for HLA-ab, and HLA specificity testing (LABScreen, OneLambda), which revealed Class I antibodies, corresponding to 38% CPRA. Per the ind-PAS package insert, the sensitivity of the assay was 85%-91% compared to selected HLA-ab tests; other sources have demonstrated lower sensitivity of 68%.

Results (if a Case Study enter NA)

NA.

Conclusion

The three cases highlight the importance of investigating incongruent results. Cases #1 and #2 demonstrate pitfalls in the PXM: ABO incompatibility can result in positive PXM and false-negative PXM can occur in the setting of high HLA-ab burden. Case #3 reveals the importance of knowing a test’s limitation, especially sensitivity. Centers that only perform ind-PAS may miss HLA-ab detection.

Severe neonatal hypercalcemia revealing congenital mesoblastic nephroma: A case report and management of neonatal hypercalcemia: Severe neonatal hypercalcemia revealing congenital mesoblastic nephroma

Congenital mesoblastic nephroma is a rare pediatric renal tumor and has been reported in patients presenting with palpable abdominal mass, arterial hypertension, hematuria, polyuria, or hypercalcemia. Here we present the case of a 1-month-old neonate with suspected parathyroid hormone (PTH)-related peptide (PTH-rp)-mediated severe hypercalcemia revealing congenital mesoblastic nephroma. Preoperatively, hypercalcemia was corrected with hydration, furosemide, pamidronate, and low-calcium infant formula. Unilateral nephrectomy led to the resolution of hypercalcemia, transient hyperparathyroidism, and transient vitamin D and mineral supplementation. We conclude that congenital mesoblastic nephroma can secrete PTH-rp that can cause severe hypercalcemia.

Real-world comparison of the last generation balloon-expandable and self-expanding valves in patients undergoing TAVI

Background/Introduction

The balloon expandable (BE) Edwards Sapien-S3/Ultra, and the self-expanding (SE) Medtronic Evolut-Pro represent the main volume of transcatheter aortic valve implantation (TAVI) procedures conducted worldwide.

Purpose

The present study represents the largest real-world comparison of periprocedural and short-term outcome between the aforementioned last generation devices.

Methods

Consecutive patients who had undergone TAVI with either the BE (S3/Ultra) or SE (Evolut-Pro/R-34mm if 34mm valve was required) device, in five centers were retrospectively studied. Periprocedural and short-term outcomes were recorded and compared.

Results

In total, 1341 patients (58.5% male) were treated with contemporary BE and SE valves (574 and 767pts with BE and SE respectively) and followed up for a median of 18.7 (IQR 30) months. Baseline demographics were similar between the two groups apart from severe left ventricle (LV) systolic impairment and extensive aorta calcification, being more prevalent amongst BE and SE groups respectively. Patients treated with the Evolut-Pro/R34mm device had significantly lower peak (16±9mmHg for SE vs 23.9±6mmHg for the BE valves, p=0.001) and mean (8.6±6mmHg SE vs 11.2±5.2mmHg BE, p=0.001) gradients at discharge.

Conversely, the BE group demonstrated significantly lower rates of at least moderate residual aortic regurgitation (AR) post-operatively (0.7% vs 5.2% for BE and SE valves respectively, p<0.001). Interestingly, the rate of new permanent pacemaker (PPM) required after the implantation in initially pacemaker-free patients, was higher for the S3/Ultra cohort compared to the self-expanding valve group (14.4% vs 12.3% respectively, p=0.001). No statistical difference was recorded between valve groups regarding cerebrovascular events (3.4% vs. 2.7% for SE and BE respectively, p=0.466), major vascular complications (4.2% vs. 3.0% for SE and BE respectively, p=0.251) and death to hospital discharge (1.6% vs. 2.9% for SE and BE respectively, p=0.117).

One-year Kaplan-Meier estimated survival was similar between the two groups (88.7% for BE vs. 91.4% for SE valves, plog-rank=0.093). When adjusting for age, extensive calcification of the aorta and baseline LV function all caused mortality hazard ratios were similar between patients treated with BE vs SE valves (HR 1.39; 95% CI 0.97 to 1.98, p=0.07).

Conclusions

Real life comparison of the last generation balloon expandable and self-expanding devices demonstrates superiority of the former in terms of residual PVL, at the expense of higher transvalvular gradients and higher need of new PPM implantation. The latter however may represent differences in center practices with regards to thresholds for permanent pacing. Long-term follow-up and future larger trials are required to establish any potential long-term difference in clinical outcomes and prognosis.

Funding Acknowledgement

Type of funding sources: None.

Ultrasound screening for abdominal aortic aneurysm in high-risk women

Background

Population-wide ultrasound screening programmes for abdominal aortic aneurysm (AAA) for men have already been established in some countries. Women account for one third of aneurysm-related mortality and are four times more likely to experience an AAA rupture than men. Whole-population screening for AAA in women is unlikely to be clinically or economically effective. The aim of this study was to determine the outcomes of a targeted AAA screening programme for women at high risk of AAA.

Method

Women aged 65–74 years deemed at high risk of having an AAA (current smokers, ex-smokers, or with a history of coronary artery disease) were invited to attend ultrasound screening (July 2016 to March 2019) for AAA in the Female Aneurysm screening STudy (FAST). Primary outcomes were attendance for screening and prevalence of AAA. Biometric data, medical history, quality of life (QoL) and aortic diameter on ultrasound imaging were recorded prospectively.

Results

Some 6037 women were invited and 5200 attended screening (86.7 per cent). Fifteen AAAs larger than 29 mm were detected (prevalence 0.29 (95 per cent c.i. 0.18 to 0.48) per cent). Current smokers had the highest prevalence (0.83 (95 per cent c.i. 0.34 to 1.89) per cent) but lowest attendance (75.2 per cent). Three AAAs greater than 5.5 cm were identified and referred for consideration of surgical repair; one woman underwent repair. There was a significant reduction in patient-reported QoL scores following screening.

Conclusion

A low prevalence of AAA was detected in high-risk women, with lowest screening uptake in those at highest risk. Screening for AAA in high-risk women may not be beneficial.

The Value of Preventative Dental Care: A Discrete-Choice Experiment

Scale and polish (SP) and oral hygiene advice (OHA) are commonly provided in primary care dental practice to help prevent periodontal disease. These services are widely consumed by service users, incurring substantial cost, without any clear evidence of clinical benefit. This article aims to elicit general population preferences and willingness to pay (WTP) for preventative dental care services and outcomes. An online discrete-choice experiment (DCE) was completed by a nationally representative sample of the UK general population. Respondents each answered 10 choice tasks that varied in terms of service attributes (SP, OHA, and provider of care), outcomes (bleeding gums and aesthetics), and cost. Choice tasks were selected using a pivoted segmented experimental design to improve task realism. An error components panel logit model was used to analyze the data. Marginal WTP (mWTP) for each attribute and level was calculated. In total, 667 respondents completed the DCE. Respondents valued more frequent SP, care provided by a dentist, and personalized OHA. Respondents were willing to pay for dental packages that generated less frequent ("never" or "hardly ever") bleeding on brushing and teeth that look and feel at least "moderately clean." Respondents were willing to pay more (+£145/y) for improvements in an aesthetic outcome from "very unclean" (-£85/y) to "very clean" (+£60/y) than they were for reduced bleeding frequency (+£100/y) from "very often" (-£54/y) to "never" (+£36/y). The general population value routinely provided SP, even in the absence of reductions in bleeding on brushing. Dental care service providers must consider service user preferences, including preferences for both health and nonhealth outcomes, as a key factor in any service redesign. Furthermore, the results provide mWTP estimates that can be used in cost-benefit analysis of these dental care services.

Long term survival in high-risk patients after percutaneous mitral leaflet repair in a single centre: comparable mortality regardless of aetiology

Background

Percutaneous mitral leaflet repair (PMVR) is a safe and effective alternative to conventional surgery in high-risk patients with both degenerative (DMR) and functional (FMR) mitral regurgitation. We present an analysis of a large cohort of consecutive patients treated with PMVR at a high-volume UK centre.

Purpose

We sought to analyse the outcomes of a group of patients undergoing PMVR over a 7-year period at a single centre, where surgery had been excluded. We hypothesised that the long-term mortality in this group would be high and would differ depending on the aetiology of MR.

Methods

We identified 246 consecutive patients over the duration of the PMVR programme, where follow up and pre-procedural data were available. We collected baseline characteristics including age at procedure, left ventricular ejection fraction (LVEF), left ventricular indexed diastolic volumes (LVEDVi) and aetiology of MR. Post procedural data included MR at end of procedure, all-cause mortality and duration of follow up.

Results

Baseline characteristics for the group, as a whole, were as follows: mean age 76±11 years, 170 (69%) male, DMR 136 (55%) vs. FMR 110 (45%), LVEF 49±15%. Baseline data by aetiology subgroup: mean age DMR 80±9 vs. FMR 71±11 (p<0.001), LVEF DMR 58±10 vs. FMR 40±14 (p<0.001), LVEDVi DMR 71±25 FMR 85±25 (p<0.001). 99% of patients were treated with the MitraClip® device (Abbott, US), 1% received the Pascal device (Edwards, US). Post-procedural MR grade was similar for both groups (DMR 1.5±0.8 vs. 1.4±0.8, p=NS). Overall procedural mortality was 0.4% and at a mean follow up of 1097 days (median 1021, IQR 289–1555) was 30.8%. Mortality was identical regardless of aetiology (DMR 30.9% vs. FMR 30.8%, p=NS).

Conclusions

This analysis of consecutive “real world” patients demonstrates encouraging survival outcome at a mean of 3 years after PMVR, regardless of MR aetiology. DMR patients tended to be older but with lower LVEDVi and significantly higher LVEF. These data compare favourably with the published literature, where mortality for mixed and similarly high-risk populations at 12 months averages approximately 20–25%. Mortality in our FMR group at 3 years was also similar to that seen in the recently published COAPT study at 2 years. We have demonstrated that PMVR is a safe option for our cohort of unselected high-risk patients presenting with either degenerative or functional MR. We hypothesise that the absence of survival difference could relate to the younger age of FMR patients despite the significantly lower baseline LVEF and higher ventricular volumes. This analysis encourages the more routine use of PMVR for FMR in the UK, where currently only DMR is commissioned.

Funding Acknowledgement

Type of funding source: None

Left ventricular remodeling after transcatheter mitral valve replacement with Tendyne

Background

Data on changes in left atrial (LA) and left ventricular (LV) volumes after transcatheter mitral valve replacement (TMVR) are limited.

Purpose

This study sought to describe the anatomical and functional changes in left-sided cardiac chambers by computed tomography angiography (CTA) from baseline to 1-month after TMVR with Tendyne prosthesis.

Methods

We analyzed patients who underwent TMVR with Tendyne prosthesis (Abbott Structural, Menlo Park, CA) between 2015 and 2018. Changes in LV end-diastolic volume (LVEDV), ejection fraction (LVEF), mass (LV mass), LA volume and global longitudinal strain (GLS) were assessed at baseline and at 1-month after TMVR with CTA. Specific Tendyne implant characteristics were identified and correlated with remodeling changes.

Results

A total of 36 patients (mean age 73±8 years, 78% men, 86% secondary MR) were studied. There were significant decreases in LVEDV (268±68 vs. 240±66ml, p<0.001), LVEF (38±10 vs. 32±11%, p<0.001), LV mass (126±37 vs. 117±32g, p<0.001), LA volume (181±74 vs. 174±70 ml, p=0.027) and GLS (−12.6±5.1 vs. −9.5±4.0%, p<0.001) from baseline to 1-month follow-up. Favorable LVEDV reverse-remodeling occurred in the majority (30 of 36 patients, or 83%). Closer proximity of the Tendyne apical pad to the true apex was predictive of favorable remodeling (pad distance: 25.0±7.7 vs. 33.5±8.8mm, p=0.02 for those with and without favorable remodeling).

Conclusions

TMVR with Tendyne results in favorable left-sided chamber remodeling in the majority of patients treated, as detected on CTA at 1-month after implantation. CTA identifies the favorable post-TMVR changes, which could be related to specific characteristics of the device implantation.

Funding Acknowledgement

Type of funding source: None

Bioprosthetic valve thrombosis and degeneration following transcatheter aortic valve implantation (TAVI)

Bioprosthetic valve thrombosis (BPVT) is a recognised complication of prosthetic aortic valves and can be found in up to 13% of patients after transcatheter implantation. The mechanism of BPVT is not well known, abnormal flow conditions in the new and native sinuses and lack of functional endothelialisation are suspected causes. BPVT may result in valve dysfunction, possibly related to degeneration, and recurrence of patient symptoms, or remain subclinical. BPVT is best diagnosed at multiphase gated computed tomography (CT) angiography as the presence of reduced leaflet motion (RELM) and hypoattenuating aortic leaflet thickening (HALT). Although CT is used to exclude BPVT in symptomatic patients and those with increased valve gradients, the value of screening and prophylactic anticoagulation is debatable.

A multicentre, clinical evaluation of a hydro-responsive wound dressing: the Glasgow experience

OBJECTIVE

Our aim was to assess the effectiveness of hydro-responsive wound dressing (HRWD) in debridement and wound bed preparation of a variety of acute and chronic wounds that presented with devitalised tissue needing removal so that healing may proceed.

METHOD

This was a non-comparative evaluation of acute and chronic wounds that required debridement as part of their normal treatment regimen. Clinicians recorded wound changes including a subjective assessment level of devitalised tissue and wound bed preparation, presence of pain, wound status (e.g., wound size) and periwound skin condition. Data was also collected from clinicians and patients to provide information on clinical performance of the dressing.

RESULTS

We recruited 100 patients with a variety of wound types into the study. Over 90% of the clinicians reported removal of devitalised tissue to enable a healing response in both chronic and acute wounds. Specifically, over the course of the evaluation period, levels of devitalised tissue (necrosis and slough) reduced from 85.5% to 26.3%, and this was accompanied by an increase in wound bed granulation from 12.0% to 33.7%. Correspondingly, there was a 40% reduction in wound area, hence a clinically relevant healing response was seen upon treatment with HRWD. It is also noteworthy that this patient population included a significant proportion of chronic wounds (51.4%) that showed no signs of wound progression within <4 weeks before study inclusion. Of these chronic wounds, 93% demonstrated wound progression upon treatment with HRWD. Despite reported pain levels being low pre- and post-dressing change, overall wound pain improved (reduced) in 48% of patients. Periwound skin condition showed a tendency towards improvement, and the fluid management capabilities of the HRWD was reported as good to excellent in the majority of cases. Wound infections were reduced by at least 60% over the evaluation period. A simple cost-effective analysis demonstrated significant savings using HRWD (£6.33) over current standard practice regimens of a four-step debridement process (£8.05), larval therapy (£306.39) and mechanical pad debridement (£11.46).

CONCLUSION

HRWD was well tolerated and was demonstrated to be an efficient debridement tool providing rapid, effective and pain free debridement in a variety of wound types.

Protocol for a Randomised controlled trial to Evaluate the effectiveness and cost benefit of prescribing high dose FLuoride toothpaste in preventing and treating dEntal Caries in high-risk older adulTs (reflect trial)

BACKGROUND

Dental caries in the expanding elderly, predominantly-dentate population is an emerging public health concern. Elderly individuals with heavily restored dentitions represent a clinical challenge and significant financial burden for healthcare systems, especially when their physical and cognitive abilities are in decline. Prescription of higher concentration fluoride toothpaste to prevent caries in older populations is expanding in the UK, significantly increasing costs for the National Health Services (NHS) but the effectiveness and cost benefit of this intervention are uncertain. The Reflect trial will evaluate the effectiveness and cost benefit of General Dental Practitioner (GDP) prescribing of 5000 ppm fluoride toothpaste and usual care compared to usual care alone in individuals 50 years and over with high-risk of caries.

METHODS/DESIGN

A pragmatic, open-label, randomised controlled trial involving adults aged 50 years and above attending NHS dental practices identified by their dentist as having high risk of dental caries. Participants will be randomised to prescription of 5000 ppm fluoride toothpaste (frequency, amount and duration decided by GDP) and usual care only. 1200 participants will be recruited from approximately 60 dental practices in England, Scotland and Northern Ireland and followed up for 3 years. The primary outcome will be the proportion of participants receiving any dental treatment due to caries. Secondary outcomes will include coronal and root caries increments measured by independent, blinded examiners, patient reported quality of life measures, and economic outcomes; NHS and patient perspective costs, willingness to pay, net benefit (analysed over the trial follow-up period and modelled lifetime horizon). A parallel qualitative study will investigate GDPs' practises of and beliefs about prescribing the toothpaste and patients' beliefs and experiences of the toothpaste and perceived impacts on their oral health-related behaviours.

DISCUSSION

The Reflect trial will provide valuable information to patients, policy makers and clinicians on the costs and benefits of an expensive, but evidence-deficient caries prevention intervention delivered to older adults in general dental practice.

TRIAL REGISTRATION

ISRCTN: 2017-002402-13 registered 02/06/2017, first participant recruited 03/05/2018. Ethics Reference No: 17/NE/0329/233335. Funding Body: Health Technology Assessment funding stream of National Institute for Health Research. Funder number: HTA project 16/23/01. Trial Sponsor: Manchester University NHS Foundation Trust, Oxford Road, Manchester, M13 9WL. The Trial was prospectively registered.

Neurodevelopmental outcomes among extremely premature infants with linear growth restriction

OBJECTIVE

To compare neurodevelopmental outcomes in linear growth-restricted (LGR) infants born <29 weeks with and without weight gain out of proportion to linear growth.

STUDY DESIGN

We compared 2-year neurodevelopmental outcomes between infants with and without LGR and between LGR infants with and without weight gain out of proportion to linear growth. The outcomes were Bayley-III cognitive, motor, and language scores, cerebral palsy, Gross Motor Function Classification System (GMFCS) level ≥ 2, and neurodevelopmental impairment.

RESULT

In total, 1227 infants were analyzed. LGR infants were smaller and less mature at birth, had higher BMI, and had lower Bayley-III language scores (82.3 vs. 85.0, p < 0.05). Among infants with LGR, infants with high BMI had lower language scores compared with those with low-to-normal BMI (80.8 vs. 83.3, p < 0.05), and were more likely to have GMFCS level ≥2 and neurodevelopmental impairment.

CONCLUSION

Among infants with LGR, weight gain out of proportion to linear growth was associated with poorer neurodevelopmental outcomes.

Diabetes UK evidence-based nutrition guidelines for the prevention and management of diabetes

A summary of the latest evidence-based nutrition guidelines for the prevention and management of diabetes is presented. These guidelines are based on existing recommendations last published in 2011, and were formulated by an expert panel of specialist dietitians after a literature review of recent evidence. Recommendations have been made in terms of foods rather than nutrients wherever possible. Guidelines for education and care delivery, prevention of Type 2 diabetes, glycaemic control for Type 1 and Type 2 diabetes, cardiovascular disease risk management, management of diabetes-related complications, other considerations including comorbidities, nutrition support, pregnancy and lactation, eating disorders, micronutrients, food supplements, functional foods, commercial diabetic foods and nutritive and non-nutritive sweeteners are included. The sections on pregnancy and prevention of Type 2 diabetes have been enlarged and the weight management section modified to include considerations of remission of Type 2 diabetes. A section evaluating detailed considerations in ethnic minorities has been included as a new topic. The guidelines were graded using adapted 'GRADE' methodology and, where strong evidence was lacking, grading was not allocated. These 2018 guidelines emphasize a flexible, individualized approach to diabetes management and weight loss and highlight the emerging evidence for remission of Type 2 diabetes. The full guideline document is available at www.diabetes.org.uk/nutrition-guidelines.

A critical review of the potential impacts of marine seismic surveys on fish & invertebrates

Marine seismic surveys produce high intensity, low-frequency impulsive sounds at regular intervals, with most sound produced between 10 and 300Hz. Offshore seismic surveys have long been considered to be disruptive to fisheries, but there are few ecological studies that target commercially important species, particularly invertebrates. This review aims to summarise scientific studies investigating the impacts of low-frequency sound on marine fish and invertebrates, as well as to critically evaluate how such studies may apply to field populations exposed to seismic operations. We focus on marine seismic surveys due to their associated unique sound properties (i.e. acute, low-frequency, mobile source locations), as well as fish and invertebrates due to the commercial value of many species in these groups. The main challenges of seismic impact research are the translation of laboratory results to field populations over a range of sound exposure scenarios and the lack of sound exposure standardisation which hinders the identification of response thresholds. An integrated multidisciplinary approach to manipulative and in situ studies is the most effective way to establish impact thresholds in the context of realistic exposure levels, but if that is not practical the limitations of each approach must be carefully considered.

The role of the clinical biochemist in detection of zinc-induced copper deficiency

A middle-aged woman with neutropenia and ataxia was found to have raised plasma zinc and profoundly low plasma copper concentrations. When found that she had been prescribed 135 mg zinc/day for seven years, a diagnosis of zinc-induced copper deficiency was made. After the zinc prescription was stopped, her copper and zinc concentrations and neutropenia normalized but she only had partial improvement in neurological status. The diagnosis of zinc-induced copper deficiency can be facilitated by the laboratory through measurement of plasma zinc concentration in patients with a low plasma copper concentration.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Whole blood manganese concentrations in dogs with primary hepatitis

OBJECTIVES

Increased whole blood manganese concentrations have been reported in humans with primary liver disease. Due to the neurotoxic effects of manganese, altered manganese homeostasis has been linked to the development of hepatic encephalopathy. Whole blood manganese concentrations are increased in cases of canine congenital portosystemic shunts, but it remains unclear whether dogs with primary hepatopathies also have altered manganese homeostasis.

METHODS

Whole blood manganese concentrations were measured by graphite furnace atomic absorption spectrometry in 21 dogs with primary hepatitis, 65 dogs with a congenital portosystemic shunt, 31 dogs with non-hepatic illnesses and 18 healthy dogs.

RESULTS

The whole blood manganese concentrations were significantly different between dogs with primary hepatitis, dogs with non-hepatic illnesses and healthy dogs (P=0·002). Dogs with primary hepatitis had significantly increased whole blood manganese concentrations compared with healthy dogs (P<0·05) and dogs with non-hepatic illnesses (P<0·01). Dogs with primary hepatitis had significantly lower whole blood manganese concentration compared with dogs with congenital portosystemic shunts (P=0·0005).

CLINICAL SIGNIFICANCE

Dogs with primary hepatopathies have increased concentrations of whole blood manganese although these concentrations are not as high as those in dogs with congenital portosystemic shunts. The role of altered manganese homeostasis in canine hepatic encephalopathy is worthy of further study.

Achondroplasia: anaesthetic challenges for caesarean section

Pregnancy in women with achondroplasia presents major challenges for anaesthetists and obstetricians. We report the case of a woman with achondroplasia who underwent general anaesthesia for an elective caesarean section. She was 99cm in height and her condition was further complicated by severe kyphoscoliosis and previous back surgery. She was reviewed in the first trimester at the anaesthetic high-risk clinic. A multidisciplinary team was convened to plan her peripartum care. Because of increasing dyspnoea caesarean section was performed at 32weeks of gestation. She received a general anaesthetic using a modified rapid-sequence technique with remifentanil and rocuronium. The intraoperative period was complicated by desaturation and high airway pressures. The woman's postoperative care was complicated by respiratory compromise requiring high dependency care.

Regional cerebral blood flow in children from 3 to 5 months of age

BACKGROUND AND PURPOSE

Understanding the relationship between brain and behavior in early childhood requires a probe of functional brain development. We report the first large study of regional CBF by use of arterial spin-labeling in young children.

MATERIALS AND METHODS

Cerebral blood flow by use of arterial spin-labeling was measured in 61 healthy children between the ages of 3 and 5 months. Blood flow maps were parcellated into 8 broadly defined anatomic regions of each cerebral hemisphere.

RESULTS

There was no sex effect; however, group analysis demonstrated significantly greater CBF in the sensorimotor and occipital regions compared with dorsolateral prefrontal, subgenual, and orbitofrontal areas (P < .0001). A significant age effect was also identified, with the largest increase in blood flow between 3 and 5 months occurring in the following regions: orbitofrontal (P < .009), subgenual (P < .002), and inferior occipital lobe (P = .001).

CONCLUSIONS

These results are consistent with prior histologic studies demonstrating regional variation in brain maturation and suggest that arterial spin-labeling is sensitive to regional as well as age-related differences in CBF in young children.

Evaluating dentin surface treatments for resin-modified glass ionomer restorative materials

This in vitro study evaluated the effect of six surface treatments on the shear bond strength of three resin-modified glass ionomers (RMGIs) to dentin. Occlusal surfaces of caries-free third molars were reduced to expose only dentin. Surface treatments were smear layer intact (negative control), Cavity Conditioner, EDTA, Ketac Primer, Self Conditioner, and etching with 35% phosphoric acid followed by the application of Optibond Solo Plus. Filtek Z250 composite resin bonded with Optibond Solo Plus served as a positive control. Conditioning agents were used according to the manufacturers' instructions. After surface treatments, Fuji II LC, Riva LC, Ketac Nano, and Filtek Z250 were placed in copper-band matrices 5 mm in diameter and 2 mm in height and were light-cured for 20 seconds. Specimens were stored in 100% humidity for 24 hours, after which they were placed in deionized water for 24 hours at 37°C. They were then tested under shear forces in an Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min. A two-way analysis of variance and Tukey honestly significant difference statistical analyses (p<0.05) indicated significant interaction between RMGIs and conditioning agents. Acid etching followed by Optibond Solo Plus provided highest bond strengths for all three RMGIs, which were not statistically different from the positive control.