Ischemia but no obstructive coronary artery disease: more than meets the eye.

Symptomatic women with angina are more likely to have ischemia with no obstructive coronary arteries (INOCA) compared to men. In both men and women, the finding of INOCA is not benign and is associated with adverse cardiovascular events, including myocardial infarction, heart failure and angina hospitalizations. Women with INOCA have more angina and a lower quality of life compared to men, but they are often falsely reassured because of a lack of obstructive coronary artery disease (CAD) and a perception of low risk. Coronary microvascular dysfunction (CMD) is a key pathophysiologic contributor to INOCA, and non-invasive imaging methods are used to detect impaired microvascular flow. Coronary vasospasm is another mechanism of INOCA, and can co-exist with CMD, but usually requires invasive coronary function testing (CFT) with provocation testing for a definitive diagnosis. In addition to traditional heart disease risk factors, inflammatory, hormonal and psychological risk factors that impact microvascular tone are implicated in INOCA. Treatment of risk factors and use of anti-atherosclerotic and anti-anginal medications offer benefit. Increasing awareness and early referral to specialized centers that focus on INOCA management can improve patient-oriented outcomes. However, large, randomized treatment trials to investigate the impact on major adverse cardiovascular events (MACE) are needed. In this focused review, we discuss the prevalence, pathophysiology, presentation, diagnosis and treatment of INOCA.

Methods and reference data for middle ear transfer functions.

Human temporal bone specimens are used in experiments measuring the sound transfer of the middle ear, which is the standard method used in the development of active and passive middle ear implants. Statistical analyses of these experiments usually require that the TB samples are representative of the population of non-pathological middle ears. Specifically, this means that the specimens must be mechanically well-characterized. We present an in-depth statistical analysis of 478 data sets of middle ear transfer functions (METFs) from different laboratories. The data sets are preprocessed and various contributions to the variance of the data are evaluated. We then derive a statistical range as a reference against which individual METF measurements may be validated. The range is calculated as the two-sided 95% tolerance interval at audiological frequencies. In addition, the mean and 95% confidence interval of the mean are given as references for assessing the validity of a sample group. Finally, we provide a suggested procedure for measuring METFs using the methods described herein.

Anticholinergic burden of patients with dementia attending a Psychiatry of Later Life service.

OBJECTIVES: Older adults with dementia are particularly vulnerable to adverse outcomes resulting from anticholinergic use. We aimed to: (i) Examine the anticholinergic burden of patients with dementia attending a Psychiatry of Later Life (PLL) service (ii) Examine concomitant prescription of acetylcholinesterase inhibitors (AChEIs) and anticholinergics and (iii) Compare the Anticholinergic Cognitive Burden (ACB) scale with a recently published composite list of anticholinergics. METHODS: Retrospective chart review of new referrals with a diagnosis of dementia (n = 66) seen by the PLL service, Tallaght University Hospital, Dublin, Ireland, over a consecutive period of 4 months. RESULTS: The mean ACB score was 2.2 (range = 0-9, SD = 2.1). 37.9% (n = 25) had a clinically significant ACB score (>3) and 42.1% (n = 8) of those taking AChEIs had a clinically significant ACB score. A significantly greater number of medications with anticholinergic activity were identified using the composite list versus the traditional ACB scale (2.3 v.1.5, p = 0.001). CONCLUSIONS: We demonstrated a significant anticholinergic burden amongst patients with dementia attending a specialist PLL service. There was no difference in anticholinergic burden between groups prescribed and not prescribed AChEIs, indicating that these medications are being prescribed without discontinuation of potentially inappropriate medications with anticholinergic activity. The true anticholinergic burden experienced by patients may be underestimated by the use of the ACB score alone, although the clinical significance of this finding is unclear. Calculation of true clinical anticholinergic burden load and its translation to a specific rating scale remains a challenge.

Genetically determined folate deficiency is associated with abnormal hepatic folate profiles in the spontaneously hypertensive rat.

Increased levels of plasma cysteine are associated with obesity and metabolic disturbances. Our recent genetic analyses in spontaneously hypertensive rats (SHR) revealed a mutated Folr1 (folate receptor 1) as the quantitative trait gene associated with diminished renal Folr1 expression, lower plasma folate levels, hypercysteinemia, hyperhomocysteinemia and metabolic disturbances. To further analyse the effects of the Folr1 gene expression on folate metabolism, we used mass spectrometry to quantify folate profiles in the plasma and liver of an SHR-1 congenic strain, with wild type Folr1 allele on the SHR genetic background, and compared them with the SHR strain. In the plasma, concentration of 5-methyltetrahydrofolate (5mTHF) was significantly higher in SHR-1 congenic rats compared to SHR (60+/-6 vs. 42+/-2 nmol/l, P<0.01) and 5mTHF monoglutamate was the predominant form in both strains (>99 % of total folate). In the liver, SHR-1 congenic rats showed a significantly increased level of 5mTHF and decreased concentrations of dihydrofolate (DHF), tetrahydrofolate (THF) and formyl-THF when compared to the SHR strain. We also analysed the extent of folate glutamylation in the liver. Compared with the SHR strain, congenic wild-type Folr1 rats had significantly higher levels of 5mTHF monoglutamate. On the other hand, 5mTHF penta- and hexaglutamates were significantly higher in SHR when compared to SHR-1 rats. This inverse relationship of rat hepatic folate polyglutamate chain length and folate sufficiency was also true for other folate species. These results strongly indicate that the whole body homeostasis of folates is substantially impaired in SHR rats compared to the SHR-1 congenic strain and might be contributing to the associated metabolic disturbances observed in our previous studies.

A targeted sequencing panel identifies rare damaging variants in multiple genes in the cranial neural tube defect, anencephaly.

Neural tube defects (NTDs) affecting the brain (anencephaly) are lethal before or at birth, whereas lower spinal defects (spina bifida) may lead to lifelong neurological handicap. Collectively, NTDs rank among the most common birth defects worldwide. This study focuses on anencephaly, which despite having a similar frequency to spina bifida and being the most common type of NTD observed in mouse models, has had more limited inclusion in genetic studies. A genetic influence is strongly implicated in determining risk of NTDs and a molecular diagnosis is of fundamental importance to families both in terms of understanding the origin of the condition and for managing future pregnancies. Here we used a custom panel of 191 NTD candidate genes to screen 90 patients with cranial NTDs (n = 85 anencephaly and n = 5 craniorachischisis) with a targeted exome sequencing platform. After filtering and comparing to our in-house control exome database (N = 509), we identified 397 rare variants (minor allele frequency, MAF < 1%), 21 of which were previously unreported and predicted damaging. This included 1 frameshift (PDGFRA), 2 stop-gained (MAT1A; NOS2) and 18 missense variations. Together with evidence for oligogenic inheritance, this study provides new information on the possible genetic causation of anencephaly.

PGC-1α4 gene expression is suppressed by the IL-6-MEK-ERK 1/2 MAPK signalling axis and altered by resistance exercise, obesity and muscle injury.

AIM: PGC-1α4 is a novel regulator of muscle hypertrophy; however, there is limited understanding of the regulation of its expression and role in many (patho)physiological conditions. Therefore, our purpose was to elicit signalling mechanisms regulating gene expression of Pgc1α4 and examine its response to (patho)physiological stimuli associated with altered muscle mass. METHODS: IL-6 knockout mice and pharmacological experiments in C2C12 myocytes were used to identify regulation of Pgc1α4 transcription. To examine Pgc1α4 gene expression in (patho)physiological conditions, obese and lean Zucker rats with/without resistance exercise (RE), ageing mice and muscle regeneration from injury were examined. RESULTS: In IL-6 knockout mice, Pgc1α4mRNA was ~sevenfold greater than wild type. In C2C12 cells, Pgc1α4mRNA was suppressed ~70% by IL-6. Suppression of Pgc1α4 by IL-6 was prevented by MEK-ERK-MAPK inhibition. RE led to ~260% greater Pgc1α4mRNA content in lean rats. However, obese Zucker rats exhibited ~270% greater Pgc1α4mRNA than lean, sedentary with no further augmentation by RE. No difference was seen in IL-6mRNA or ERK-MAPK phosphorylation in Zucker rats. Aged mice demonstrated ~50% lower Pgc1α4mRNA and ~fivefold greater ERK-MAPK phosphorylation than young despite unchanged Il-6mRNA. During muscle regeneration, Pgc1α4 content is ~30% and IL-6mRNA >threefold of uninjured controls 3 days following injury; at 5 days, Pgc1α4 was >twofold greater in injured mice with no difference in IL-6mRNA. CONCLUSION: Our findings reveal a novel mechanism suppressing Pgc1α4 gene expression via IL-6-ERK-MAPK and suggest this signalling axis may inhibit Pgc1α4 in some, but not all, (patho)physiological conditions.

Increased pediatric sub-specialization is associated with decreased surgical complication rates for inpatient pediatric urology procedures.

INTRODUCTION: Increased case volumes and training are associated with better surgical outcomes. However, the impact of pediatric urology sub-specialization on perioperative complication rates is unknown. OBJECTIVES: To determine the presence and magnitude of difference in rates of common postoperative complications for elective pediatric urology procedures between specialization levels of urologic surgeons. The Nationwide Inpatient Sample (NIS), a nationally representative administrative database, was used. STUDY DESIGN: The NIS (1998-2009) was retrospectively reviewed for pediatric (≤18 years) admissions, using ICD-9-CM codes to identify urologic surgeries and National Surgical Quality Improvement Program (NSQIP) inpatient postoperative complications. Degree of pediatric sub-specialization was calculated using a Pediatric Proportion Index (PPI), defined as the ratio of children to total patients operated on by each provider. The providers were grouped into PPI quartiles: Q1, 0-25% specialization; Q2, 25-50%; Q3, 50-75%; Q4, 75-100%. Weighted multivariate analysis was performed to test for associations between PPI and surgical complications. RESULTS: A total of 71,479 weighted inpatient admissions were identified. Patient age decreased with increasing specialization: Q1, 7.9 vs Q2, 4.8 vs Q3, 4.8 vs Q4, 4.6 years, P < 0.01). Specialization was not associated with race (P > 0.20), gender (P > 0.50), or comorbidity scores (P = 0.10). Mortality (1.5% vs 0.2% vs 0.3% vs 0.4%, P < 0.01) and complication rates (15.5% vs 11.7% vs 9.6% vs 10.9%, P < 0.0001) both decreased with increasing specialization. Patients treated by more highly specialized surgeons incurred slightly higher costs (Q2, +4%; Q3, +1%; Q4 + 2%) but experienced shorter length of hospital stay (Q2, -5%; Q3, -10%; Q4, -3%) compared with the least specialized providers. A greater proportion of patients treated by Q1 and Q3 specialized urologists had CCS ≥2 than those seen by Q2 or Q4 urologists (12.5% and 12.2%, respectively vs 8.4% and 10.9%, respectively, P = 0.04). Adjusting for confounding effects, increased pediatric specialization was associated with decreased postoperative complications: Q2 OR 0.78, CI 0.58-1.05; Q3 OR 0.60, CI 0.44-0.84; Q4 OR 0.70, CI 0.58-0.84; P < 0.01. DISCUSSION: Providers with proportionally higher volumes of pediatric patients achieved better postoperative outcomes than their less sub-specialized counterparts. This may have arisen from increased exposure to pediatric anatomy and physiology, and greater familiarity with pediatric techniques. LIMITATION: The NIS admission-based retrospective design did not enable assessment of long-term outcomes, repeated admissions, or to track a particular patient across time. The study was similarly limited in evaluating the effect of pre-surgical referral patterns on patient distributions. CONCLUSIONS: Increased pediatric sub-specialization among urologists was associated with a decreased risk of mortality and surgical complications in children undergoing inpatient urologic procedures.

Translational machinery of mitochondrial mRNA is promoted by physical activity in Western diet-induced obese mice.

AIM: Mitochondria-encoded proteins are necessary for oxidative phosphorylation; however, no report has examined how physical activity (PA) and obesity affect mitochondrial mRNA translation machinery. Our purpose was to determine whether Western diet (WD)-induced obesity and voluntary wheel running (VWR) impact mitochondrial mRNA translation machinery and whether expression of this machinery is dictated by oxidative phenotype. METHODS: Obesity was induced with 8-wk WD feeding, and in the final 4 wks, half of mice were allowed VWR. Mitochondrial mRNA translation machinery including initiation factors (mtIF2/3), elongation factor Tu (TUFM) and translational activator (TACO1), and mitochondria-encoded proteins (CytB and ND4) was assessed by immunoblotting. The relation of mitochondrial mRNA translation to muscle oxidative phenotype was assessed using PGC-1α transgenic overexpression (MCK-PGC-1α vs. wild-type mice) and comparing across muscle groups in wild-type mice. RESULTS: mtIF3 and TACO1 proteins were ~45% greater in VWR than sedentary (SED), and TACO1 and mtIF2 proteins were ~60% and 125% greater in WD than normal chow (NC). TUFM protein was ~50% lower in WD-SED than NC-SED, but ~50% greater in WD-VWR compared to NC-SED. CytB and ND4 were ~40% greater in VWR and ND4 was twofold greater with WD. TUFM, TACO1, ND4 and CytB were greater in MCK-PGC-1α compared to wild-type, and mtIF2/3 contents were not different. In oxidative muscle (soleus), mitochondrial translation machinery was elevated compared to mixed (gastrocnemius) or glycolytic (extensor digitorum longus) muscles. CONCLUSION: These data suggest a novel mechanism promoting mitochondrial function by translation of mitochondrial protein following PA. This may act to promote muscle health by PA in obesity.

Diet-induced obesity alters anabolic signalling in mice at the onset of skeletal muscle regeneration.

AIM: Obesity is classified as a metabolic disorder that is associated with delayed muscle regeneration following damage. For optimal skeletal muscle regeneration, inflammation along with extracellular matrix remodelling and muscle growth must be tightly regulated. Moreover, the regenerative process is dependent on the activation of myogenic regulatory factors (MRFs) for myoblast proliferation and differentiation. The purpose of this study was to determine how obesity alters inflammatory and protein synthetic signalling and MRF expression at the onset of muscle regeneration in mice. METHODS: Forty-eight male C57BL/6J mice (3 weeks old) were randomly assigned to either a high-fat diet (HFD, 60% fat) or a lean diet (10% fat) for 12 weeks. At 15 weeks, bupivacaine was injected into the tibialis anterior (TA) of the injured group (n = 5-8/group) and PBS was injected into the control (n = 5-6). The TA was excised 3 or 28 days after injection. RESULTS: We demonstrated impaired muscle regeneration in obese mice. The obese mice had reduced IL-6, MyoD and IGF-1 mRNA abundance compared to the lean mice (P < 0.05). Three days following muscle damage, TNF-α mRNA and protein levels of P-STAT3 and P-Akt were 14-fold, fourfold and fivefold greater in the lean mice respectively. However, there were no differences observed in the obese injured group compared to the uninjured group. Moreover, p70S6K1 was threefold greater in lean injured mice compared to uninjured but was reduced by 28% in the obese injured mice. CONCLUSION: Obese mice have impaired inflammatory and protein synthetic signalling that may negatively influence muscle regeneration.

Reproductive factors and Parkinson's disease risk in Danish women.

BACKGROUND AND PURPOSE: Parkinson's disease is more common in men than women by a ratio of about 1.5:1 and yet there is no consensus to date as to whether female reproductive factors including hormone use affect Parkinson's disease risk. Our objective was to examine the relationship between Parkinson's disease and female reproductive factors in the largest population-based Parkinson's disease case-control study to date. METHODS: Seven hundred and forty-three female Parkinson's disease cases diagnosed between 1996 and 2009 were selected from the Danish National Hospital Register, diagnoses confirmed by medical record review, and the cases were matched by birth year to 765 female controls randomly selected from the Danish Civil Registration System. Covariate information was collected in computer-assisted telephone interviews covering an extensive array of topics including reproductive and lifestyle factors. RESULTS: After adjusting for smoking, caffeine and alcohol use, education, age, and family Parkinson's disease history, inverse associations between Parkinson's disease and early menarche (first period at ≤11 years), oral contraceptives, high parity (≥4 children) and bilateral oophorectomy were found; adjusted odds ratios and 95% confidence limits were respectively 0.68 (0.45-1.03) for early menarche, 0.87 (0.69-1.10) for oral contraceptives, 0.79 (0.59-1.06) for high parity and 0.65 (0.45-0.94) for bilateral oophorectomy. Little support for associations between Parkinson's disease and fertile life length, age at menopause or post-menopausal hormone treatment was found. CONCLUSIONS: Reproductive factors related to women's early- to mid-reproductive lives appear to be predictive of subsequent Parkinson's disease risk whereas factors occurring later in life seem less important.

A novel mouse model for genetic variation in 10-formyltetrahydrofolate synthetase exhibits disturbed purine synthesis with impacts on pregnancy and embryonic development.

Genetic variants in one-carbon folate metabolism have been identified as risk factors for disease because they may impair the production or use of one-carbon folates required for nucleotide synthesis and methylation. p.R653Q (1958G>A) is a single-nucleotide polymorphism (SNP) in the 10-formyltetrahydrofolate (formylTHF) synthetase domain of the trifunctional enzyme MTHFD1; this domain produces the formylTHF which is required for the de novo synthesis of purines. Approximately 20% of Caucasians are homozygous for the Q allele. MTHFD1 p.R653Q has been proposed as a risk factor for neural tube defects (NTDs), congenital heart defects (CHDs) and pregnancy losses. We have generated a novel mouse model in which the MTHFD1 synthetase activity is inactivated without affecting protein expression or the other activities of this enzyme. Complete loss of synthetase activity (Mthfd1S(-/-)) is incompatible with life; embryos die shortly after 10.5 days gestation, and are developmentally delayed or abnormal. The proportion of 10-formylTHF in the plasma and liver of Mthfd1S(+/-) mice is reduced (P < 0.05), and de novo purine synthesis is impaired in Mthfd1S(+/-) mouse embryonic fibroblasts (MEFs, P < 0.005). Female Mthfd1S(+/-) mice had decreased neutrophil counts (P < 0.05) during pregnancy and increased incidence of developmental defects in embryos (P = 0.052). These findings suggest that synthetase deficiency may lead to pregnancy complications through decreased purine synthesis and reduced cellular proliferation. Additional investigation of the impact of synthetase polymorphisms on human pregnancy is warranted.

Frontomaxillary facial angle in fetuses with spina bifida at 11-13 weeks' gestation.

OBJECTIVE: To determine whether in fetuses with open spina bifida at 11-13 weeks' gestation the frontomaxillary facial angle is decreased. METHODS: The frontomaxillary facial angle was measured in 20 fetuses with open spina bifida and in 100 normal controls matched for crown-rump length (CRL) at 11 + 0 to 13 + 6 weeks and the values in the two groups were compared. RESULTS: In the control group the frontomaxillary facial angle decreased significantly with CRL from a mean of 84.0 degrees at a CRL of 45 mm to 76.5 degrees at a CRL of 84 mm (SD, 3.26 degrees). In the spina bifida group the mean frontomaxillary facial angle, corrected for CRL, was 9.9 degrees lower than in the controls and it was below the 5(th) centile in 18 (90%) of the cases (P < 0.0001). CONCLUSIONS: In fetuses with open spina bifida at 11-13 weeks' gestation the frontomaxillary facial angle is decreased and this measurement may be useful in early screening for this abnormality.

First-trimester trisomy screening: nuchal translucency measurement training and quality assurance to correct and unify technique.

OBJECTIVE: To describe the process of training for measuring nuchal translucency at five clinical centers in North America and to evaluate methods of quality assurance and feedback. DESIGN: Throughout a period of 18 months, the performance of sonographers in measuring fetal nuchal translucency was monitored using qualitative and quantitative methods of review. After 12 months, different approaches (written and personal feedback) were used to inform sonographers of technical aspects that needed to or could be improved. RESULTS: On initial qualitative review, discrepancies in judgment from different reviewers coincided with suboptimal magnification, failure to visualize the amniotic membrane and/or use of cross-shaped calipers. At subsequent global review, 13 (29%) images of nuchal translucency measurements were considered unacceptable. Quantitative assessment revealed that, during the first part of the study, the means from four sonographers were significantly smaller and the mean from the fifth sonographer was significantly larger than expected on the basis of findings from The Fetal Medicine Foundation (P < 0.0001). Following feedback, sonographers who underestimated nuchal translucency and who received a written report only did not change measurements overall (P = 0.9759). In contrast, those who received additional intervention showed a marked difference (P < 0.0001). CONCLUSIONS: Global qualitative review of images from one sonographer may be preferable to assessment of individual aspects of images. Results from global qualitative review correspond well with findings from quantitative analysis, indicating that the latter can be applied for ongoing audit. Observation of divergent results should prompt extensive personal feedback, rather than a written report, to prevent sonographers from settling in their own, inappropriate technique.

Differentiation between bone infarction and acute osteomyelitis in children with sickle-cell disease with use of sequential radionuclide bone-marrow and bone scans.

BACKGROUND: The differentiation of bone infarction from acute osteomyelitis in patients with sickle-cell disease is challenging, as the clinical presentations of the two conditions are similar and imaging and laboratory studies are of limited value. METHODS: A combination of radionuclide bone-marrow and bone scans was performed sequentially within a twenty-four-hour period (with one exception) to aid in the differentiation between bone infarction and osteomyelitis in seventy-nine consecutive episodes of acute bone pain in children with sickle-cell disease. RESULTS: Seventy cases of bone infarction were diagnosed on the basis of decreased uptake on the bone-marrow scan and abnormal uptake on the bone scan at the site of pain. Antibiotic administration was discontinued in sixty-six of the seventy cases after the imaging results were obtained, and the bone pain resolved. In four of the seventy-nine cases, there was normal uptake on the bone-marrow scan and abnormal uptake on the bone scan at the site of pain, findings that were suggestive of acute osteomyelitis. In three of these cases, osteomyelitis was proven by culture, and the symptoms in all four resolved with antibiotic treatment. In five of the seventy-nine cases, the bone-marrow and bone scans were normal and thought to indicate neither osteomyelitis nor bone infarction; in all of these cases, the symptoms resolved without the use of antibiotics. CONCLUSIONS: These findings suggest that osteomyelitis can be differentiated from bone infarction in children with sickle-cell anemia and acute bone pain by a combination of sequential bone-marrow and bone scintigraphy.

Identification of a transactivation motif in the CLN3 protein.

A transactivation motif has been identified in the neurodegenerative disease protein, CLN3. The C-terminal domain (residues 394-438) of CLN3 can function as a transcriptional activator when fused to the DNA binding domain, LexA. A series of deletion and substitution constructs have been generated to identify the essential region for transactivation. A similar motif is also present in the POU domain transcription factor, nubbin. However, this domain alone does not activate transcription, allowing further localisation of the critical residues in CLN3 required for activity.