Early diagnosis and treatment by newborn screening (NBS) or family history is associated with improved visual outcomes for long-chain 3-hydroxyacylCoA dehydrogenase deficiency (LCHADD) chorioretinopathy

Long chain 3-hydroxyacyl-CoA dehydrogenase (LCHADD) is the only fatty acid oxidation disorder to develop a progressive chorioretinopathy resulting in vision loss; newborn screening (NBS) for this disorder began in the United States around 2004. We compared visual outcomes among 40 participants with LCHADD or trifunctional protein deficiency diagnosed symptomatically to those who were diagnosed via NBS or a family history. Participants completed ophthalmologic testing including measures of visual acuity, electroretinograms (ERG), fundal imaging, contrast sensitivity, and visual fields. Records were reviewed to document medical and treatment history. Twelve participants presented symptomatically with hypoglycemia, failure to thrive, liver dysfunction, cardiac arrest, or rhabdomyolysis. Twenty eight were diagnosed by NBS or due to a family history of LCHADD. Participants diagnosed symptomatically were older but had similar percent males and genotypes as those diagnosed by NBS. Treatment consisted of fasting avoidance, dietary long-chain fat restriction, MCT, C7, and/or carnitine supplementation. Visual acuity, rod- and cone-driven amplitudes on ERG, contrast sensitivity scores, and visual fields were all significantly worse among participants diagnosed symptomatically compared to NBS. In mixed-effects models, both age and presentation (symptomatic vs. NBS) were significant independent factors associated with visual outcomes. This suggests that visual outcomes were improved by NBS, but there was still lower visual function with advancing age in both groups. Early diagnosis and treatment by NBS is associated with improved visual outcomes and retinal function compared to participants who presented symptomatically. Despite the impact of early intervention, chorioretinopathy was greater with advancing age, highlighting the need for novel treatments.

A proposal for an updated staging system for LCHADD retinopathy

OBJECTIVE

To develop an updated staging system for long-chain 3-hydroxyacyl coenzyme A dehydrogenase deficiency (LCHADD) chorioretinopathy based on contemporary multimodal imaging and electrophysiology.

METHODS

We evaluated forty cases of patients with genetically confirmed LCHADD or trifunctional protein deficiency (TFPD) enrolled in a prospective natural history study. Wide-field fundus photographs, fundus autofluorescence (FAF), optical coherence tomography (OCT), and full-field electroretinogram (ffERG) were reviewed and graded for severity.

RESULTS

Two independent experts first graded fundus photos and electrophysiology to classify the stage of chorioretinopathy based upon an existing published system. With newer imaging modalities and improved electrophysiology, many patients did not fit cleanly into a single traditional staging group. Therefore, we developed a novel staging system that better delineated the progression of LCHADD retinopathy. We maintained the four previous delineated stages but created substages A and B in stages 2 to 3 to achieve better differentiation.

DISCUSSION

Previous staging systems of LCHADD chorioretinopathy relied on only on the assessment of standard 30 to 45-degree fundus photographs, visual acuity, fluorescein angiography (FA), and ffERG. Advances in recordings of ffERG and multimodal imaging with wider fields of view, allow better assessment of retinal changes. Following these advanced assessments, seven patients did not fit neatly into the original classification system and were therefore recategorized under the new proposed system.

CONCLUSION

The new proposed staging system improves the classification of LCHADD chorioretinopathy, with the potential to lead to a deeper understanding of the disease's progression and serve as a more reliable reference point for future therapeutic research.

Entangling microwaves with light

Quantum entanglement is a key resource in currently developed quantum technologies. Sharing this fragile property between superconducting microwave circuits and optical or atomic systems would enable new functionalities, but this has been hindered by an energy scale mismatch of >10⁴ and the resulting mutually imposed loss and noise. In this work, we created and verified entanglement between microwave and optical fields in a millikelvin environment. Using an optically pulsed superconducting electro-optical device, we show entanglement between propagating microwave and optical fields in the continuous variable domain. This achievement not only paves the way for entanglement between superconducting circuits and telecom wavelength light, but also has wide-ranging implications for hybrid quantum networks in the context of modularization, scaling, sensing, and cross-platform verification.

Seizures after epidural blood patch in a postpartum patient later diagnosed with hypertension and proteinuria: a diagnostic conundrum

Seizures are a rare, but documented, consequence of accidental dural puncture and epidural blood patch. They are also the cardinal feature of eclampsia. We present a postpartum patient who suffered a tonic-clonic seizure within 1 hour of an epidural blood patch procedure for a suspected post-dural puncture headache. Investigations also revealed hypertension, proteinuria and subdural collections. This case demonstrates the diagnostic dilemma associated with postpartum headache and late postpartum eclampsia. We illustrate the importance of a thorough clinical assessment of postpartum patients presenting with headache, highlighting the possibility of more than one underlying pathological cause. We also consider the role of epidural blood patch in both precipitating, and preventing, complications of accidental dural puncture.

Neurocognitive, neuropsychiatric, and neurological outcomes associated with phenylalanine hydroxylase deficiency: Assessment considerations for nurse practitioners

PURPOSE

The purpose of this article is to review literature for neurocognitive, neuropsychiatric, neurological complications associated with phenylalanine hydroxylase (PAH) deficiency. The goal is to familiarize nurse practitioners with treatment and monitoring guidelines for persons living with the disorder.

CONCLUSIONS

Appropriate treatment can maximize neurocognitive and neuropsychiatric outcomes.

PRACTICE IMPLICATIONS

Nurse practitioners can help persons with PAH deficiency through education and providing appropriate referrals and by supporting disease-specific treatment.

Converting microwave and telecom photons with a silicon photonic nanomechanical interface

Practical quantum networks require low-loss and noise-resilient optical interconnects as well as non-Gaussian resources for entanglement distillation and distributed quantum computation. The latter could be provided by superconducting circuits but existing solutions to interface the microwave and optical domains lack either scalability or efficiency, and in most cases the conversion noise is not known. In this work we utilize the unique opportunities of silicon photonics, cavity optomechanics and superconducting circuits to demonstrate a fully integrated, coherent transducer interfacing the microwave X and the telecom S bands with a total (internal) bidirectional transduction efficiency of 1.2% (135%) at millikelvin temperatures. The coupling relies solely on the radiation pressure interaction mediated by the femtometer-scale motion of two silicon nanobeams reaching a Vπ as low as 16 μV for sub-nanowatt pump powers. Without the associated optomechanical gain, we achieve a total (internal) pure conversion efficiency of up to 0.019% (1.6%), relevant for future noise-free operation on this qubit-compatible platform.

Comparison of gait kinematics in total and unicondylar knee replacement surgery

INTRODUCTION

This study is aimed to compare kinematic gait data of patients who have undergone total and unicondylar knee replacement.

MATERIALS AND METHODS

This single-surgeon retrospective cohort study evaluated 13 patients with unilateral total knee arthroplasty (TKA) and 14 unicondylar knee arthroplasty (UKA). Gait analysis was carried out using a Vicon motion analysis system. The limits of knee flexion during stance phase, at heel strike and at loading response were measured.

RESULTS

The total range of motion of the UKA knees was significantly greater than the TKA knees. UKA knees exhibited significantly greater knee extension during the stance phase than the TKA knees. Unlike TKA, UKA knees demonstrated improved knee flexion during the gait cycle when compared to the contralateral non-operated knee. The hips also demonstrated near normal hip flexion in UKA patients. Predictably, UKA knees had significantly greater varus compared with TKA in the coronal plane. Spatiotemporal variables demonstrated similar walking speed and step length to aid a fair comparison between knee replacement groups.

CONCLUSIONS

The UKA knees moved more physiologically in the sagittal plane with a greater range of motion during gait. Despite having a stiff gait pattern, the patients undergoing TKA demonstrated a more neutral alignment in the coronal plane. Neither type of knee arthroplasty restored knee kinematics to those of the non-operated side.

Continuous monitoring and feedback of quality of recovery indicators for anaesthetists: a qualitative investigation of reported effects on professional behaviour

Background

Research suggests that providing clinicians with feedback on their performance can result in professional behaviour change and improved clinical outcomes. Departments would benefit from understanding which characteristics of feedback support effective quality monitoring, professional behaviour change and service improvement. This study aimed to report the experience of anaesthetists participating in a long-term initiative to provide comprehensive personalized feedback to consultants on patient-reported quality of recovery indicators in a large London teaching hospital.

Methods

Semi-structured interviews were conducted with 13 consultant anaesthetists, six surgical nursing leads, the theatre manager and the clinical coordinator for recovery. Transcripts were qualitatively analysed for themes linked to the perceived value of the initiative, its acceptability and its effects upon professional practice.

Results

Analysis of qualitative data from participant interviews suggested that effective quality indicators must address areas that are within the control of the anaesthetist. Graphical data presentation, both longitudinal (personal variation over time) and comparative (peer-group distributions), was found to be preferable to summary statistics and provided useful and complementary perspectives for improvement. Developing trust in the reliability and credibility of the data through co-development of data reports with clinical input into areas such as case-mix adjustment was important for engagement. Making feedback specifically relevant to the recipient supported professional learning within a supportive and open collaborative environment.

Conclusions

This study investigated the requirements for effective feedback on quality of anaesthetic care for anaesthetists, highlighting the mechanisms by which feedback may translate into improvements in practice at the individual and peer-group level.

Comparison of gait kinetics in total and unicondylar knee replacement surgery

Introduction The aim of this study was to compare kinetical data from gait analysis of patients who have undergone total and uni-condylar knee replacement. Materials and methods Thirteen patients with unilateral total knee arthroplasty (TKA) and 13 unicondylar knee arthroplasty (UKA), were included, all performed by the same surgeon more than one year prior. The Vicon gait analysis system was used. Statistical power was calculated using SPSS. Results No significant difference was found in the spatiotemporal parameters of gait and survival years of the knee prosthesis between the two groups. The UKA group was found to have significantly larger moments than the TKA group in knee adduction on the operated side and knee flexion moment on the unoperated side during the loading phase. The maximum and minimum sagittal plane moments of the operated sides in the TKA group were significantly lower than the unoperated side. The difference was most significant at pre-swing. The maximum and minimum moments on the operated sides in the UKA group were significantly lower for the knee flexion and adduction moments when compared with the unoperated side and were most prevalent during the loading phase. Conclusions These results are relevant in terms of prosthesis wear. The TKA knees had smaller magnitude moments than the UKA knees in the sagittal and coronal planes. This could explain the higher revision rates for UKA. In both groups, the non-operated knees had significantly larger moments than the operated knees, which implies that after unilateral knee replacement of either type, the non-operated knee is being put under greater stress.

CGRP Release and c-fos Expression within Trigeminal Nucleus Caudalis of the Rat following Glyceryltrinitrate Infusion

Neuropeptide release and the expression of c-fos like immunoreactivity (c-fos LI) within trigeminal nucleus caudalis neurons (TNC) are activation markers of the trigeminal nerve system. Glyceryltrinitrate (GTN) is believed to stimulate the trigeminal nerve system, thereby causing headache. We examined the effects of a 30 min NO-donor infusion on CGRP release in jugular vein blood and c-fos LI within TNC of the rat. GTN (2 and 50 μg/kg/min) or NONOate infusion (25 nmol/kg/min) did not cause any CGRP release during and shortly after infusion, whereas administration of capsaicin resulted in strongly increased CGRP levels. GTN infusion (2 μg/kg/min for 30 min) did not lead to enhanced c-fos LI after 2 h and 4 h, whereas capsaicin infusion caused a time- and dose-dependent expression of c-fos LI within laminae I and II of the TNC. Surprisingly, GTN attenuated capsaicin-induced c-fos expression by 64%. The nitric oxide synthase (NOS) inhibitor L-NAME (5 and 50 mg/kg) reduced capsaicin-induced c-fos LI dose dependently (reduction by 13% and 59%). We conclude that GTN may lead to headaches by mechanisms independent of CGRP release from trigeminal nerve fibres. GTN doses comparable to those used in humans did not activate or sensitize the trigeminal nerve system. Both GTN and L-NAME reduced capsaicin-induced c-fos LI. This is most likely due to a feedback inhibition of nitric oxide synthases, which indicates that the c-fos response to capsaicin within TNC is mediated by NO dependent mechanisms.

The Use of Radiolabelled Human Serum Albumin and SPECT/MRI Co-Registration to Study Inflammation in The Cavernous Sinus of Cluster Headache Patients

A sterile inflammation in the cavernous sinus was hypothesized to underlie cluster headache (CH). Neurogenic inflammation is accompanied by the extravasation of plasma proteins in the surrounding tissue. We tested the hypothesis of an inflammatory process in the cavernous sinus in CH patients using 99mTc-human serum albumin (HSA) and single photon emission computed tomography (SPECT). Six patients with episodic CH were enrolled. After baseline imaging, CH attacks were induced by IV injection of nitroglycerin. The patients remained untreated for 20 min. A second SPECT was performed after successful treatment. Region of interest (ROI) analysis was performed on the basis of coregistered MRI/SPECT data. There was no statistical difference between the 99mTc-HSA uptake in the ipsilateral cavernous sinus before and after induction of an acute CH attack. There was no evidence for 99mTc-HSA extravasation in the cavernous sinus during the active episode as compared with the remission phase. Our results do not support the hypothesis of an inflammation in the cavernous sinus.

The diurnal cycle of water ice on comet 67P/Churyumov-Gerasimenko

Observations of cometary nuclei have revealed a very limited amount of surface water ice, which is insufficient to explain the observed water outgassing. This was clearly demonstrated on comet 9P/Tempel 1, where the dust jets (driven by volatiles) were only partially correlated with the exposed ice regions. The observations of 67P/Churyumov-Gerasimenko have revealed that activity has a diurnal variation in intensity arising from changing insolation conditions. It was previously concluded that water vapour was generated in ice-rich subsurface layers with a transport mechanism linked to solar illumination, but that has not hitherto been observed. Periodic condensations of water vapour very close to, or on, the surface were suggested to explain short-lived outbursts seen near sunrise on comet 9P/Tempel 1. Here we report observations of water ice on the surface of comet 67P/Churyumov-Gerasimenko, appearing and disappearing in a cyclic pattern that follows local illumination conditions, providing a source of localized activity. This water cycle appears to be an important process in the evolution of the comet, leading to cyclical modification of the relative abundance of water ice on its surface.

COMETARY SCIENCE. The structure of the regolith on 67P/Churyumov-Gerasimenko from ROLIS descent imaging

The structure of the upper layer of a comet is a product of its surface activity. The Rosetta Lander Imaging System (ROLIS) on board Philae acquired close-range images of the Agilkia site during its descent onto comet 67P/Churyumov-Gerasimenko. These images reveal a photometrically uniform surface covered by regolith composed of debris and blocks ranging in size from centimeters to 5 meters. At the highest resolution of 1 centimeter per pixel, the surface appears granular, with no apparent deposits of unresolved sand-sized particles. The thickness of the regolith varies across the imaged field from 0 to 1 to 2 meters. The presence of aeolian-like features resembling wind tails hints at regolith mobilization and erosion processes. Modeling suggests that abrasion driven by airfall-induced particle "splashing" is responsible for the observed formations.

Complications after modern filter operations in glaucoma

As long as the indications and limitations of laser trabeculoplasty have not yet been established by follow-up over several years, conventional surgical filter operation will not be superfluous. The reduction of the complications brought about by introduction of the scleral flap technique is described. Apart from cicatricial obliteration of the filtering zone, bulbar hypotension due to overfiltration as well as to external fistula and above all the resulting ciliary body-choroid detachment still occurs after trephination with the scleral flap (goniotrephination, trabeculectomy). Attention is drawn to the tension of the scleral flap adapted to the normalized intraocular pressure and reliable preclusion of an external fistula by perfusion test at the end of the operation. The membrane formation probably deriving from the internal Tenon's capsule which leads to a 'pseudofiltering bleb' is discussed as a rare complication (1.5%) which is of basic interest.

Cometary science. The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta

The VIRTIS (Visible, Infrared and Thermal Imaging Spectrometer) instrument on board the Rosetta spacecraft has provided evidence of carbon-bearing compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The very low reflectance of the nucleus (normal albedo of 0.060 ± 0.003 at 0.55 micrometers), the spectral slopes in visible and infrared ranges (5 to 25 and 1.5 to 5% kÅ(-1)), and the broad absorption feature in the 2.9-to-3.6-micrometer range present across the entire illuminated surface are compatible with opaque minerals associated with nonvolatile organic macromolecular materials: a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. In active areas, the changes in spectral slope and absorption feature width may suggest small amounts of water-ice. However, no ice-rich patches are observed, indicating a generally dehydrated nature for the surface currently illuminated by the Sun.

Interstitial 10p11.23-p12.1 microdeletions associated with developmental delay, craniofacial abnormalities, and cryptorchidism

Cryptorchidism is the most common genital problem encountered in males and is associated with many chromosomal disorders; however, the genetic factors are mostly unknown. To delineate critical genes affecting testicular migration, we performed genotype-phenotype correlation in patients with deletions involving the proximal short arm of chromosome 10 (10p11-p12), a rare abnormality characterized by developmental delay, craniofacial abnormalities, and in some cases, cryptorchidism. Here we report on a male patient with developmental delay, mild craniofacial dysmorphism, bilateral cryptorchidism, and an 850-kb deletion, within the 10p11.2 region, involving three genes-MKX, ARMC4, and MPP7-as determined by array comparative genomic hybridization analysis. Comparison with four previously reported male patients with overlapping deletions revealed a 140-kb common region, containing the MKX gene, in association with cryptorchidism. The MKX gene is a member of the three amino acid loop extension (TALE) superclass of homeobox genes that is expressed in developing male gonads (male gonadal ridge and testis cords) in temporal relationship to SOX9, a critical regulator of sexual differentiation. Our results suggest that haploinsufficiency of the MKX gene may affect the developmental process during testis migration or serve as a genetic susceptibility locus for cryptorchidism. We propose that deletions of the proximal 10p represent a contiguous gene syndrome; therefore, patients may present with a complex phenotype, depending on the extent of the deletion.

Untersuchungen am System Spiropyran + Säure ⇄ Farbsalz / Investigations on the System Spiropyran + Acid ⇄ Pyrylium Salt

We could prove that the system spiropyran/acid/pyrylium salt follows the equilibrium relation Spiropyran+acid ⇄ pyrylium salt.

This color reaction can be used as an indicatory system. In this case the acid has to be produced instandaneously within the system. For this the spiropyran is mixed with a HX-donor which splits off a hydrogen halide HX by uv-irradiation. The coloration mechanism of layers consisting of spiropyran + HX-donor+matric forming polymer depends on the wavelength of the actinic radiation. Long wavelength uv-irradiation shows energy transfer, while only short wavelength uv-irradiation causes the primary process in the HX-donor

Spektroskopisches Verhalten von o-substituierten Arylvinylpyryliumperchloraten / Spectroscopic Behaviour of o-substituted Arylvinylpyrylium Perchlorates

The influence of the substituents on the characteristic infrared absorption frequencies and the wavelength of the absorption band in the visible region of o-substituted 2 [β-n-amyl-styryl] -1-benzopyrylium perchlorates and 3[β-n-amyl-1-naphthylvinyl]naphtho[2.1-b]pyrylium perchlorates has been investigated. The observed structural changes have been discussed as a function of the mesomeric effect of the substituents.

Beobachtungen von Elementarprozessen an angeregten Molekülen

A method is described which allows to observe only primary processes by elimination of secondary and higher processes. The products formed by dissociation of excited cyclohexane molecules are explained by innermolecular elementary processes. Two reaction schemes are discussed for the formation of the observed C2⁻, C3⁻, and C4⁻hydrocarbons, which follow from the C3 : C3⁻ and C4 : C2⁻cleavage. The experimental results establish these two reaction schemes quantitatively.

The processes for the stabilization of the formed biradicals during cleavage of the cyclohexane ring are of equal probability as it is following from the discussed reaction schemes

Zum Verhalten 5-Ring-N-heterocyclischer Spiropyrane

IR- und UV/VIS-spektroskopische Untersuchungen an höher anellierten Trimethylindolinopyranen und substituierten Trimethylindolinobenzopyranen führten zu erweiterten Kenntnissen bezüglich des Verhaltens solcher 5-Ring-N-heterocyclischer Systeme. Aus den IR-spektroskopischen Untersuchungen ging dabei hervor, daß alle bei den hier untersuchten Systemen zu beobachtenden Absorptionen durch die in Diagramm 1 skizzierten Strukturen wesentlich differenzierter beschrieben werden können als es für ein nichtprotoniertes System aus der üblichen hybriden Formulierung heraus möglich ist. Als Normalverhalten solcher Systeme beim Auftreten farbiger Formen ist die bereits von DILTHEY et al.19, 20 formulierte ionoide Dissoziation anzusehen. Das Auftreten chinoider Strukturen entspricht dagegen nicht dem Normalverhalten.

Verhalten von Spiropyranschichten gegenüber thermischer Belastung / Behaviour of Spiropyran Films by Thermal Treatment

The influence of thermal treatment of photochromic spiropyran films has been investigated. The measurements demonstrate that the decompositions of the photochromic films and the different components are changed noticeable at temperatures of 100°C and above.

Zur Darstellbarkeit von 2.2′-disubstituierten 3.3′ - Spirobi- [3H-naphtho(2.1-b)pyranen] / About the Synthesis of 2,2′-Disubstituted 3,3-Spirobi-[3H-naphtho (2,1-b)pyrans]

In both α-positions relative to the spiro-C-atom substituted spirobipyrans have the expected spiropyran structure, in spite of their exceptional behaviour that their pyrylium salts can not be isolated generally. Strong steric effects are responsible for the instability of those pyrylium salts, as it can be shown by UV- and IR-spectroscopic investigations.

Zur Isomerie von Tetrazoliumsalzen II

Durch systematische Untersuchung von Tetrazoliumsalzen mit verschiedenem Anion wie auch verschiedenem Substituenten am C-Arylrest konnte nachgewiesen werden, daß Tetrazoliumsalze generell in verschiedenen Stereoisomeren erhalten werden können.

Eine Modellvorstellung über die durch den C-Arylsubstituenten induzierten Veränderungen in der Elektronendichte-Verteilung des heterozyklischen Systems führte dabei zu einer vernünftig erscheinenden Interpretation der beobachteten Phänomene.

HBr-Quantenausbeute von mehrfach bromierten organischen Verbindungen in Methanol / HBr Quantum Efficiency of Brominated Organic Compounds in Methanol

Polybrominated HBr-donors were irradiated with UV light of the wavelength λ = 257 nm and 290 nm in methanolic solution and methanolic spiropyran solution. The quantum efficiency of the generation of HBr has been determined and discussed. With spiropyran present in the irradiated solutions the results can be explained only by the assumption of an energy transfer process between spiropyran and HBr-donors.

Spasmodic torticollis - a multicentre study on behavioural aspects IV: psychopathology

The GSI (General Symptom Index) of the Symptom Checklist 90 R (SCL 90 R) (as a global indicator of the severity of psychiatric symptoms) of 27% of the spasmodic torticollis (ST) sample fell outside the 95% range of the normal control group (two standard deviations). Patients with a higher GSI were younger, more functionally disabled and subject to higher psychosocial stress due to the illness. The highest scores were reached on the subscales of somatization, interpersonal sensitivity and depression. On the depression scale, 23% of the patients' scores were abnormal. This scale correlated significantly with the neurological signs, particularly the TSUI-index and laterocollis. A statistically significant correlation also existed between psychiatric morbidity and a family history of mental disorder. More than 50% of the patients reported that stressful life events had triggered their illness. In order of frequency, a death came first, followed by marital strife, changes in employment and family arguments. The data suggest that psychopathology in ST should generally be considered as a result of a variety of interacting factors, biological, psychological and social.

Using quality indicators in anaesthesia: feeding back data to improve care

After recent UK policy developments, considerable attention has been focused upon how clinical specialties measure and report on the quality of care delivered to patients. Defining the right indicators alone is insufficient to close the feedback loop. This narrative review aims to describe and synthesize a diverse body of research relevant to the question of how information from quality indicators can be fed back and used effectively to improve care. Anaesthesia poses certain challenges in the identification of valid outcome indicators sensitive to variations in anaesthetic care. Metrics collected during the immediate post-anaesthetic recovery period, such as patient temperature, patient-reported quality of recovery, and pain and nausea, provide potentially useful information for the anaesthetist, yet this information is not routinely fed back. Reviews of the effects of feeding back performance data to healthcare providers suggest that this may result in small to moderate positive effects upon outcomes and professional practice, with stronger effects where feedback is integrated within a broader quality improvement strategy. The dominant model for use of data within quality improvement is based upon the industrial process control approach, in which care processes are monitored continuously for process changes which are rapidly detectable for corrective action. From this review and experience of implementing these principles in practice, effective feedback from quality indicators is timely, credible, confidential, tailored to the recipient, and continuous. Considerable further work is needed to understand how information from quality indicators can be fed back in an effective way to clinicians and clinical units, in order to support revalidation and continuous improvement.

Molecular and clinical genetics of mitochondrial diseases due to POLG mutations

Mutations in the POLG gene have emerged as one of the most common causes of inherited mitochondrial disease in children and adults. They are responsible for a heterogeneous group of at least 6 major phenotypes of neurodegenerative disease that include: 1) childhood Myocerebrohepatopathy Spectrum disorders (MCHS), 2) Alpers syndrome, 3) Ataxia Neuropathy Spectrum (ANS) disorders, 4) Myoclonus Epilepsy Myopathy Sensory Ataxia (MEMSA), 5) autosomal recessive Progressive External Ophthalmoplegia (arPEO), and 6) autosomal dominant Progressive External Ophthalmoplegia (adPEO). Due to the clinical heterogeneity, time-dependent evolution of symptoms, overlapping phenotypes, and inconsistencies in muscle pathology findings, definitive diagnosis relies on the molecular finding of deleterious mutations. We sequenced the exons and flanking intron region from approximately 350 patients displaying a phenotype consistent with POLG related mitochondrial disease and found informative mutations in 61 (17%). Two mutant alleles were identified in 31 unrelated index patients with autosomal recessive POLG-related disorders. Among them, 20 (67%) had Alpers syndrome, 4 (13%) had arPEO, and 3 (10%) had ANS. In addition, 30 patients carrying one altered POLG allele were found. A total of 25 novel alterations were identified, including 6 null mutations. We describe the predicted structural/functional and clinical importance of the previously unreported missense variants and discuss their likelihood of being pathogenic. In conclusion, sequence analysis allows the identification of mutations responsible for POLG-related disorders and, in most of the autosomal recessive cases where two mutant alleles are found in trans, finding deleterious mutations can provide an unequivocal diagnosis of the disease.